Sample records for model results formats

  1. Kinetic models of opinion formation

    E-Print Network [OSTI]

    G. Toscani

    2006-05-17T23:59:59.000Z

    We introduce and discuss certain kinetic models of (continuous) opinion formation involving both exchange of opinion between individual agents and diffusion of information. We show conditions which ensure that the kinetic model reaches non trivial stationary states in case of lack of diffusion in correspondence of some opinion point. Analytical results are then obtained by considering a suitable asymptotic limit of the model yielding a Fokker-Planck equation for the distribution of opinion among individuals.

  2. Structure formation: Models, Dynamics and Status

    E-Print Network [OSTI]

    T. Padmanabhan

    1995-08-25T23:59:59.000Z

    The constraints on the models for the structure formation arising from various cosmological observations at different length scales are reviewed. The status of different models for structure formation is examined critically in the light of these observations.

  3. Autonomous Helicopter Formation using Model Predictive Control

    E-Print Network [OSTI]

    Sastry, S. Shankar

    Autonomous Helicopter Formation using Model Predictive Control Hoam Chung and S. Shankar Sastry are required to fly in tight formations and under harsh conditions. The starting point for safe autonomous into a formation, so that each vehicle can safely maintain sufficient space between it and all other vehicles

  4. Atomistic Model for the Polyamide Formation from ?-Lactam...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Model for the Polyamide Formation from ?-Lactam Catalyzed by Candida Antarctica Lipase B. Atomistic Model for the Polyamide Formation from ?-Lactam Catalyzed by Candida...

  5. Testing Disk Instability Models for Giant Planet Formation

    E-Print Network [OSTI]

    Alan P. Boss

    2007-04-09T23:59:59.000Z

    Disk instability is an attractive yet controversial means for the rapid formation of giant planets in our solar system and elsewhere. Recent concerns regarding the first adiabatic exponent of molecular hydrogen gas are addressed and shown not to lead to spurious clump formation in the author's disk instability models. A number of disk instability models have been calculated in order to further test the robustness of the mechanism, exploring the effects of changing the pressure equation of state, the vertical temperature profile, and other parameters affecting the temperature distribution. Possible reasons for differences in results obtained by other workers are discussed. Disk instability remains as a plausible formation mechanism for giant planets.

  6. Modelling new particle formation events in the South African savannah

    SciTech Connect (OSTI)

    Gierens, Rosa; Laakso, Lauri; Mogensen, Ditte; Vakkari, Ville; Buekes, Johan P.; Van Zyl, Pieter; Hakola, H.; Guenther, Alex B.; Pienaar, J. J.; Boy, Michael

    2014-05-28T23:59:59.000Z

    Africa is one of the less studied continents with respect to atmospheric aerosols. Savannahs are complex dynamic systems sensitive to climate and land-use changes, but the interaction of these systems with the atmosphere is not well understood. Atmospheric particles, called aerosols, affect the climate on regional and global scales, and are an important factor in air quality. In this study, measurements from a relatively clean savannah environment in South Africa were used to model new particle formation and growth. There already are some combined long-term measurements of trace gas concentrations together with aerosol and meteorological variables available, but to our knowledge this is the first detailed simulation that includes all the main processes relevant to particle formation. The results show that both of the particle formation mechanisms investigated overestimated the dependency of the formation rates on sulphuric acid. From the two particle formation mechanisms tested in this work, the approach that included low volatile organic compounds to the particle formation process was more accurate in describing the nucleation events than the approach that did not. To obtain a reliable estimate of aerosol concentration in simulations for larger scales, nucleation mechanisms would need to include organic compounds, at least in southern Africa. This work is the first step in developing a more comprehensive new particle formation model applicable to the unique environment in southern Africa. Such a model will assist in better understanding and predicting new particle formation – knowledge which could ultimately be used to mitigate impacts of climate change and air quality.

  7. MODELING OF ALUMINUM NANOPARTICLE FORMATION R. Schefflan

    E-Print Network [OSTI]

    MODELING OF ALUMINUM NANOPARTICLE FORMATION R. Schefflan D. Kalyon S. Kovenklioglu Stevens Picatinny Arsenal's process for making alumina coated nanoparticles of aluminum involves the conversion of gaseous aluminum, in the presence of helium carrier gas, to solid nanoparticles and their subsequent

  8. On star formation rate and turbulent dissipation in galactic models

    E-Print Network [OSTI]

    E. P. Kurbatov

    2007-12-10T23:59:59.000Z

    The models of star formation function and of dissipation of turbulent energy of interstellar medium are proposed. In star formation model the feedback of supernovae is taken into account. It is shown that hierarchical scenario of galaxy formation with proposed models is able to explain the observable star formation pause in the Galaxy.

  9. Modelling Pattern Formation in Dip-Coating Experiments

    E-Print Network [OSTI]

    Markus Wilczek; Walter B. H. Tewes; Svetlana V. Gurevich; Michael H. Köpf; Lifeng Chi; Uwe Thiele

    2015-02-12T23:59:59.000Z

    We briefly review selected mathematical models that describe the dynamics of pattern formation phenomena in dip-coating and Langmuir-Blodgett transfer experiments, where solutions or suspensions are transferred onto a substrate producing patterned deposit layers with structure length from hundreds of nanometres to tens of micrometres. The models are presented with a focus on their gradient dynamics formulations that clearly shows how the dynamics is governed by particular free energy functionals and facilitates the comparison of the models. In particular, we include a discussion of models based on long-wave hydrodynamics as well as of more phenomenological models that focus on the pattern formation processes in such systems. The models and their relations are elucidated and examples of resulting patterns are discussed before we conclude with a discussion of implications of the gradient dynamics formulation and of some related open issues.

  10. Constraining Galaxy Formation Models with Dwarf Ellipticals in Clusters

    E-Print Network [OSTI]

    Christopher J. Conselice

    2005-12-20T23:59:59.000Z

    Recent observations demonstrate that dwarf elliptical (dE) galaxies in clusters, despite their faintness, are likely a critical galaxy type for understanding the processes behind galaxy formation. Dwarf ellipticals are the most common galaxy type, and are particularly abundant in rich galaxy clusters. The dwarf to giant ratio is in fact highest in rich clusters of galaxies, suggesting that cluster dEs do not form in groups that later merge to form clusters. Dwarf ellipticals are potentially the only galaxy type whose formation is sensitive to global, rather than local, environment. The dominant idea for explaining the formation of these systems, through Cold Dark Matter models, is that dEs form early and within their present environments. Recent results suggest that some dwarfs appear in clusters after the bulk of massive galaxies form, a scenario not predicted in standard hierarchical structure formation models. Many dEs have younger and more metal rich stellar populations than dwarfs in lower density environments, suggesting processes induced by rich clusters play an important role in dE formation. Several general galaxy cluster observations, including steep luminosity functions, and the origin of intracluster light, are natural outcomes of this delayed formation.

  11. RESIDUA UPGRADING EFFICIENCY IMPROVEMENT MODELS: COKE FORMATION PREDICTABILITY MAPS

    SciTech Connect (OSTI)

    John F. Schabron; A. Troy Pauli; Joseph F. Rovani Jr.

    2002-05-01T23:59:59.000Z

    The dispersed particle solution model of petroleum residua structure was used to develop predictors for pyrolytic coke formation. Coking Indexes were developed in prior years that measure how near a pyrolysis system is to coke formation during the coke formation induction period. These have been demonstrated to be universally applicable for residua regardless of the source of the material. Coking onset is coincidental with the destruction of the ordered structure and the formation of a multiphase system. The amount of coke initially formed appears to be a function of the free solvent volume of the original residua. In the current work, three-dimensional coke make predictability maps were developed at 400 C, 450 C, and 500 C (752 F, 842 F, and 932 F). These relate residence time and free solvent volume to the amount of coke formed at a particular pyrolysis temperature. Activation energies for two apparent types of zero-order coke formation reactions were estimated. The results provide a new tool for ranking residua, gauging proximity to coke formation, and predicting initial coke make tendencies.

  12. The case against scaling defect models of cosmic structure formation

    E-Print Network [OSTI]

    Andreas Albrecht; Richard A. Battye; James Robinson

    1997-07-11T23:59:59.000Z

    We calculate predictions from defect models of structure formation for both the matter and Cosmic Microwave Background (CMB) over all observable scales. Our results point to a serious problem reconciling the observed large-scale galaxy distribution with the COBE normalization, a result which is robust for a wide range of defect parameters. We conclude that standard scaling defect models are in conflict with the data, and show how attempts to resolve the problem by considering non-scaling defects would require radical departures from the standard scaling picture.

  13. Modelling New Particle Formation Events in the South African Savannah

    SciTech Connect (OSTI)

    Gierens, Rosa; Laakso, Lauri; Mogensen, Ditte; Vakkari, Ville; Beukes, J. P.; Van Zyl, Pieter; Hakola, H.; Guenther, Alex B.; Pienaar, J. J.; Boy, Michael

    2014-01-01T23:59:59.000Z

    Africa is one of the less studied continents with respect to atmospheric aerosols. Savannahs are complex dynamic systems sensitive to climate and land-use changes, but the interaction with the atmosphere is not well understood. Atmospheric particles, aka aerosols, affect the climate on regional and global scale, and are an important factor in air quality. In this study measurements from a relatively clean savannah environment in South Africa were used to model new particle formation and growth. There are already some combined long-term measurements of trace gas concentrations together with aerosol and meteorological variables available, but to our knowledge this is the first time detailed simulations, that include all the main processes relevant to particle formation, were done. The results show that both investigated particle formation mechanisms overestimated the formation rates dependency on sulphuric acid. The approach including low volatile organic compounds to the particle formation process was more accurate in describing the nucleation events. To get reliable estimation of aerosol concentration in simulations for larger scales, nucleation mechanisms would need to include organic compounds, at least in southern Africa.

  14. Engineering Glass Passivation Layers -Model Results

    SciTech Connect (OSTI)

    Skorski, Daniel C.; Ryan, Joseph V.; Strachan, Denis M.; Lepry, William C.

    2011-08-08T23:59:59.000Z

    The immobilization of radioactive waste into glass waste forms is a baseline process of nuclear waste management not only in the United States, but worldwide. The rate of radionuclide release from these glasses is a critical measure of the quality of the waste form. Over long-term tests and using extrapolations of ancient analogues, it has been shown that well designed glasses exhibit a dissolution rate that quickly decreases to a slow residual rate for the lifetime of the glass. The mechanistic cause of this decreased corrosion rate is a subject of debate, with one of the major theories suggesting that the decrease is caused by the formation of corrosion products in such a manner as to present a diffusion barrier on the surface of the glass. Although there is much evidence of this type of mechanism, there has been no attempt to engineer the effect to maximize the passivating qualities of the corrosion products. This study represents the first attempt to engineer the creation of passivating phases on the surface of glasses. Our approach utilizes interactions between the dissolving glass and elements from the disposal environment to create impermeable capping layers. By drawing from other corrosion studies in areas where passivation layers have been successfully engineered to protect the bulk material, we present here a report on mineral phases that are likely have a morphological tendency to encrust the surface of the glass. Our modeling has focused on using the AFCI glass system in a carbonate, sulfate, and phosphate rich environment. We evaluate the minerals predicted to form to determine the likelihood of the formation of a protective layer on the surface of the glass. We have also modeled individual ions in solutions vs. pH and the addition of aluminum and silicon. These results allow us to understand the pH and ion concentration dependence of mineral formation. We have determined that iron minerals are likely to form a complete incrustation layer and we plan to look more closely at Vivianite [Fe3(PO4)2-8(H2O)] and Siderite [FeCO3] in the next stage of the project.

  15. Modeling deposit formation in diesel injector nozzle

    E-Print Network [OSTI]

    Sudhiesh Kumar, Chintoo

    2009-01-01T23:59:59.000Z

    Formation of deposit in the diesel injector nozzle affects the injection behavior and hinders performance. Under running condition, deposit precursors are washed away by the ensuing injection. However, during the cool down ...

  16. Analyze of the star formation modeling algorithm in SPH code

    E-Print Network [OSTI]

    Peter Berczik

    2001-06-06T23:59:59.000Z

    The chemical and photometric evolution of star forming disk galaxies is investigated. Numerical simulations of the complex gasdynamical flows are based on our own coding of the Chemo - Dynamical Smoothed Particle Hydrodynamical (CD - SPH) approach, which incorporates the effects of star formation. The presented model describes well the time evolution of the basic dynamical, chemical and photometric parameters of a disk galaxy similar to the Milky Way. The metallicity, luminosity and colors obtained are typical for such disk galaxies. During the calculations we made an extended test of the proposed SF criteria. We find that the obtained results with different "gas" and "star" particle numbers are not only qualitatively but also quantitatively similar.

  17. A detail study of defect models for cosmic structure formation

    E-Print Network [OSTI]

    A. Albrecht; R. A. Battye; J. Robinson

    1997-11-27T23:59:59.000Z

    We calculate predictions from wide class of `active' models of cosmic structure formation which allows us to scan the space of possible defect models. We calculate the linear cold dark matter power spectrum and Cosmic Microwave Background (CMB) anisotropies over all observable scales using a full linear Einstein-Boltzmann code. Our main result, which has already been reported, points to a serious problem reconciling the observed amplitude of the large-scale galaxy distribution with the COBE normalization. Here, we describe our methods and results in detail. The problem is present for a wide range of defect parameters, which can be used to represent potential differences among defect models, as well as possible systematic numerical errors. We explicitly examine the impact of varying the defect model parameters and we show how the results substantiate these conclusions. The standard scaling defect models are in serious conflict with the current data, and we show how attempts to resolve the problem by considering non-scaling defects or modified stress-energy components would require radical departures from what has become the standard picture.

  18. Quasi Light Fields: A Model of Coherent Image Formation

    E-Print Network [OSTI]

    Wornell, Gregory W.

    Quasi Light Fields: A Model of Coherent Image Formation Anthony Accardi and Gregory Wornell formation that strikes a balance between the simplicity of the light field and the comprehensive predictive power of Maxwell's equations, by extending the light field to coherent radiation. © 2009 Optical Society

  19. Quasi Light Fields: A Model of Coherent Image Formation

    E-Print Network [OSTI]

    Accardi, Anthony J.

    We develop a model of coherent image formation that strikes a balance between the simplicity of the light field and the comprehensive predictive power of Maxwell's equations, by extending the light field to coherent radiation.

  20. Quantum Black Hole Formation in the BFSS Matrix Model

    E-Print Network [OSTI]

    Sinya Aoki; Masanori Hanada; Norihiro Iizuka

    2015-03-18T23:59:59.000Z

    We study the various head-on collisions of two bunches of D0-branes and their real-time evolution in the BFSS matrix model in classical limit. For a various matrix size N respecting the 't Hooft scaling, we find quantitative evidence for the formation of a single bound state of D0-branes at late time, which is matrix model thermalization and dual to the formation of a larger black hole.

  1. Kinetic model for nitric oxide formation during pulverized coal combustion

    SciTech Connect (OSTI)

    Mitchell, J.W.; Tarbell, J.M.

    1982-03-01T23:59:59.000Z

    A mathematical model of NO formation during pulverised coal combustion was developed from a proposed kinetic mechanism involving 12 overall chemical reactions. Most significantly, the model describes the complex conversion of coal bound nitrogen compounds to NO during combustion. The predictions of the model compare favourably with literature data and are in qualitative agreement with trends observed in practical coal combustion.

  2. PageRank model of opinion formation on Ulam networks

    E-Print Network [OSTI]

    L. Chakhmakhchyan; D. Shepelyansky

    2013-11-03T23:59:59.000Z

    We consider a PageRank model of opinion formation on Ulam networks, generated by the intermittency map and the typical Chirikov map. The Ulam networks generated by these maps have certain similarities with such scale-free networks as the World Wide Web (WWW), showing an algebraic decay of the PageRank probability. We find that the opinion formation process on Ulam networks have certain similarities but also distinct features comparing to the WWW. We attribute these distinctions to internal differences in network structure of the Ulam and WWW networks. We also analyze the process of opinion formation in the frame of generalized Sznajd model which protects opinion of small communities.

  3. Cloud and Star Formation in Disk Galaxy Models with Feedback

    E-Print Network [OSTI]

    Rahul Shetty; Eve C. Ostriker

    2008-05-26T23:59:59.000Z

    We include feedback in global hydrodynamic simulations in order to study the star formation properties, and gas structure and dynamics, in models of galactic disks. We extend previous models by implementing feedback in gravitationally bound clouds: momentum is injected at a rate proportional to the star formation rate. This mechanical energy disperses cloud gas back into the surrounding ISM, truncating star formation in a given cloud, and raising the overall level of ambient turbulence. Propagating star formation can however occur as expanding shells collide, enhancing the density and triggering new cloud and star formation. By controlling the momentum injection per massive star and the specific star formation rate in dense gas, we find that the negative effects of high turbulence outweigh the positive ones, and in net feedback reduces the fraction of dense gas and thus the overall star formation rate. The properties of the large clouds that form are not, however, very sensitive to feedback, with cutoff masses of a few million solar masses, similar to observations. We find a relationship between the star formation rate surface density and the gas surface density with a power law index ~2 for our models with the largest dynamic range, consistent with theoretical expectations for our model of disk flaring. We point out that the value of the "Kennicutt-Schmidt" index depends on the thickness of the disk. With our simple feedback prescription (a single combined star formation event per cloud), we find that global spiral patterns are not sustained; less correlated feedback and smaller scale turbulence appear to be necessary for spiral patterns to persist.

  4. Halo Formation in Warm Dark Matter Models

    E-Print Network [OSTI]

    Paul Bode; Jeremiah P. Ostriker; Neil Turok

    2001-05-29T23:59:59.000Z

    Discrepancies have emerged between the predictions of standard cold dark matter (CDM) theory and observations of clustering on sub-galactic scales. Warm dark matter (WDM) is a simple modification of CDM in which the dark matter particles have initial velocities due either to their having decoupled as thermal relics, or having been formed via non-equilibrium decay. We investigate the nonlinear gravitational clustering of WDM with a high resolution N-body code, and identify a number of distinctive observational signatures. Relative to CDM, halo concentrations and core densities are lowered, core radii are increased, and large halos emerge with far fewer low mass satellites. The number of small halos is suppressed, and those present are formed by `top down' fragmentation of caustics, as part of a `cosmic web' connecting massive halos. Few small halos form outside this web. If we identify small halos with dwarf galaxies, their number, spatial distribution, and formation epoch appear in better agreement with the observations for WDM than they are for CDM.

  5. Modeling of NOx formation in circular laminar jet flames

    E-Print Network [OSTI]

    Siwatch, Vivek

    2007-04-25T23:59:59.000Z

    -premixed isolated circular laminar jet flame. The jet consists of the fuel rich inner region and the O2 rich outer region. The model estimates both thermal NOx and prompt NOx assuming single step kinetics for NOx formation and a thin flame model. Further the amount...

  6. A Dynamic Model of Social Network Formation Brian Skyrms 1

    E-Print Network [OSTI]

    Pemantle, Robin

    A Dynamic Model of Social Network Formation Brian Skyrms 1 Robin Pemantle 2;3 ABSTRACT: We consider a dynamic social network model in which agents play repeated games in pairings determined by a stochastically evolving social network. In- dividual agents begin to interact at random, with the interactions

  7. Structure formation in modified gravity models alternative to dark energy

    E-Print Network [OSTI]

    Kazuya Koyama

    2006-01-10T23:59:59.000Z

    We study structure formation in phenomenological models in which the Friedmann equation receives a correction of the form $H^{\\alpha}/r_c^{2-\\alpha}$, which realize an accelerated expansion without dark energy. In order to address structure formation in these model, we construct simple covariant gravitational equations which give the modified Friedmann equation with $\\alpha=2/n$ where $n$ is an integer. For $n=2$, the underlying theory is known as a 5D braneworld model (the DGP model). Thus the models interpolate between the DGP model ($n=2, \\alpha=1$) and the LCDM model in general relativity ($n \\to \\infty, \\alpha \\to 0$). Using the covariant equations, cosmological perturbations are analyzed. It is shown that in order to satisfy the Bianchi identity at a perturbative level, we need to introduce a correction term $E_{\\mu \

  8. Structure formation in modified gravity models alternative to dark energy

    E-Print Network [OSTI]

    Koyama, K

    2006-01-01T23:59:59.000Z

    We study structure formation in phenomenological models in which the Friedmann equation receives a correction of the form $H^{\\alpha}/r_c^{2-\\alpha}$, which realize an accelerated expansion without dark energy. In order to address structure formation in these model, we construct simple covariant gravitational equations which give the modified Friedmann equation with $\\alpha=2/n$ where $n$ is an integer. For $n=2$, the underlying theory is known as a 5D braneworld model (the DGP model). Thus the models interpolate between the DGP model ($n=2, \\alpha=1$) and the LCDM model in general relativity ($n \\to \\infty, \\alpha \\to 0$). Using the covariant equations, cosmological perturbations are analyzed. It is shown that in order to satisfy the Bianchi identity at a perturbative level, we need to introduce a correction term $E_{\\mu \

  9. Nepheline Formation Study for Sludge Batch 4 (SB4): Phase 1 Experimental Results

    SciTech Connect (OSTI)

    Peeler, D. K.; Edwards, T. B.; Reamer, I.A.; Workman, R. J.

    2005-09-30T23:59:59.000Z

    Although it is well known that the addition of Al{sub 2}O{sub 3} to borosilicate glasses enhances the durability of the waste form (through creation of network-forming tetrahedral Na+-[AlO{sub 4/2}]{sup -} pairs), the combination of high Al{sub 2}O{sub 3} and Na{sub 2}O can lead to the formation of nepheline (NaAlSiO{sub 4})--which can negatively impact durability. Given the projected high concentration of Al{sub 2}O{sub 3} in SB4 (Lilliston 2005) and the potential use of a high Na{sub 2}O based frit to improve melt rate and a high Na{sub 2}O sludge due to settling problems, the potential formation of nepheline in various SB4 systems continues to be assessed. Twelve SB4-based glasses were fabricated and their durabilities (via the Product Consistency Test [PCT]) measured to assess the potential for nepheline formation and its potential negative impact on durability. In terms of ''acceptability'', the results indicate that all of the study glasses produced are acceptable with respect to durability as defined by the PCT (normalized boron release values for all nepheline (NEPH) glasses were much lower than that of the Environmental Assessment (EA) glass (16.695 g/L)). The most durable glass is NEPH-04 (quenched) with a normalized boron release (NL [B]) of 0.61 g/L, while the least durable glass is NEPH-01 centerline canister cooled (ccc) with an NL [B] of 2.47 g/L (based on the measured composition). In terms of predictability, most of the study glasses are predictable by the {Delta}G{sub p} model. Those that are not predictable (i.e., they fall outside of the prediction limits) actually fall below the prediction interval (i.e., they are over predicted by the model) suggesting the model is conservative. The Phase 1 PCT results suggest that for those glasses prone to nepheline formation (using the 0.62 value developed by Li et al. (2003) as a guide), a statistically significant difference in PCT response was observed for the two heat treatments but the impact on durability was of little or no practical concern. When one couples the PCT responses with the X-Ray Diffraction (XRD) results and/or visual observations, one could conclude that the formation of nepheline in these glasses does have a negative impact on durability. However, that impact may be of statistical significance, but the practical impact may not be sufficient to avoid a specific candidate frit for the SB4 glass system. The results of this study not only suggest that the 0.62 value appears to be a reasonable guide to monitor sludge--frit systems with respect to potential nepheline formation, but also that the impact of nepheline, although statistically significant, has little or no practical impact in the SB4 system to durability as measured by the PCT. This latter statement must be qualified to some extent given only two glasses were selected which were actually ''prone to nepheline formation'' based on this general guide and the relatively volume % of nepheline formed based on XRD results ({approx} 0.5 vol%). If the presence of nepheline has no appreciable, adverse impact on durability for the recently revised SB4 systems, then as decisions regarding the viability of the SB4 options and the down select of candidate frits are pursued, little weight will be given to minimizing the likelihood of nepheline and the decisions will be dominated by waste throughput criteria. That is, the frit selection process will not have to consider the impact of nepheline on the ultimate durability of the product and can focus on recommending a frit that when coupled with the sludge can be processed over a waste loading (WL) interval of interest to the Defense Waste Processing Facility (DWPF) with melt rates meeting production expectations.

  10. Modeling Coupled Processes in Clay Formations for Radioactive Waste Disposal

    SciTech Connect (OSTI)

    Liu, Hui-Hai; Rutqvist, Jonny; Zheng, Liange; Sonnenthal, Eric; Houseworth, Jim; Birkholzer, Jens

    2010-08-31T23:59:59.000Z

    As a result of the termination of the Yucca Mountain Project, the United States Department of Energy (DOE) has started to explore various alternative avenues for the disposition of used nuclear fuel and nuclear waste. The overall scope of the investigation includes temporary storage, transportation issues, permanent disposal, various nuclear fuel types, processing alternatives, and resulting waste streams. Although geologic disposal is not the only alternative, it is still the leading candidate for permanent disposal. The realm of geologic disposal also offers a range of geologic environments that may be considered, among those clay shale formations. Figure 1-1 presents the distribution of clay/shale formations within the USA. Clay rock/shale has been considered as potential host rock for geological disposal of high-level nuclear waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures induced by tunnel excavation. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at Mol site, Belgium (Barnichon et al., 2005) have all been under intensive scientific investigations (at both field and laboratory scales) for understanding a variety of rock properties and their relations with flow and transport processes associated with geological disposal of nuclear waste. Clay/shale formations may be generally classified as indurated and plastic clays (Tsang et al., 2005). The latter (including Boom clay) is a softer material without high cohesion; its deformation is dominantly plastic. For both clay rocks, coupled thermal, hydrological, mechanical and chemical (THMC) processes are expected to have a significant impact on the long-term safety of a clay repository. For example, the excavation-damaged zone (EDZ) near repository tunnels can modify local permeability (resulting from induced fractures), potentially leading to less confinement capability (Tsang et al., 2005). Because of clay's swelling and shrinkage behavior (depending on whether the clay is in imbibition or drainage processes), fracture properties in the EDZ are quite dynamic and evolve over time as hydromechanical conditions change. To understand and model the coupled processes and their impact on repository performance is critical for the defensible performance assessment of a clay repository. Within the Natural Barrier System (NBS) group of the Used Fuel Disposition (UFD) Campaign at DOE's Office of Nuclear Energy, LBNL's research activities have focused on understanding and modeling such coupled processes. LBNL provided a report in this April on literature survey of studies on coupled processes in clay repositories and identification of technical issues and knowledge gaps (Tsang et al., 2010). This report will document other LBNL research activities within the natural system work package, including the development of constitutive relationships for elastic deformation of clay rock (Section 2), a THM modeling study (Section 3) and a THC modeling study (Section 4). The purpose of the THM and THC modeling studies is to demonstrate the current modeling capabilities in dealing with coupled processes in a potential clay repository. In Section 5, we discuss potential future R&D work based on the identified knowledge gaps. The linkage between these activities and related FEPs is presented in Section 6.

  11. Legrand BBBP Implementation Model Designed for Results

    E-Print Network [OSTI]

    Horton, P.

    2013-01-01T23:59:59.000Z

    SUSTAINABILITY Legrand North America Designed for Results BBBP Implementation Model Pete Horton, VP Business Development, Legrand/Watt Stopper Industrial Energy Technology Conference May 23, 2013 May 23, 20133 ESL-IE-13-05-21 Proceedings... of the Thrity-Fifth Industrial Energy Technology Conference New Orleans, LA. May 21-24, 2013 SUSTAINABILITY Overview ? Company Introduction ? Our Commitment ? BBBP Initiative ? Our Strategy ?Our Implementation Model: Sub Metering ? Sub metering Concept...

  12. Thermo-mechanical modelling of Black Sea Basin (de)formation S. Cloetingh*, G. Spadini1

    E-Print Network [OSTI]

    Beekman, Fred

    Thermo-mechanical modelling of Black Sea Basin (de)formation S. Cloetingh*, G. Spadini1 , J.D. Van; received in revised form 7 January 2002; accepted 19 July 2002 Abstract We present the results of a thermo by rifting and subsequent sediment loading. Thermo-mechanical modelling of integrated lithospheric strength

  13. Uncalibrated Building Energy Simulation Modeling Results 

    E-Print Network [OSTI]

    Ahmad, M.; Culp, C.H.

    2006-01-01T23:59:59.000Z

    VOLUME 12, NUMBER 4 HVAC&R RESEARCH OCTOBER 2006 1141 Uncalibrated Building Energy Simulation Modeling Results Mushtaq Ahmad Charles H. Culp, PhD, PE Associate Member ASHRAE Fellow ASHRAE Received June 23, 2005; accepted April 17, 2006... the uncalibrated simulations were completed. The dis- crepancies between the simulated and measured total yearly building energy use varied over ±30% with one outlier. The results show that discrepancies ranged over ±90% between the sim- ulations and the measured...

  14. Stimulation results in the low-permeability Wasatch formation - An evolution to foam fracturing

    SciTech Connect (OSTI)

    Harris, P.C.; Bailey, D.E.; Evertz, G.L.

    1984-05-01T23:59:59.000Z

    The Wasatch Formation of the Uinta Basin in eastern Utah is typical of many formations in the Rocky Mountains, having low permeability and high sensitivity to water. Stimulation treatments with several types of fracturing fluids, including oilwater emulsion fluids, complex gel fluids and foam fluids, have been generally successful. Production decline curves from twenty four wells in the field were used for comparison of the different stimulation methods. Although foam fracturing has been used for the shortest period of time, comparison of the production histories show the relatively higher efficiency of the foam fracturing treatments compared to other stimulation methods in the Wasatch formation. Foam fluids gave higher production rates and higher flowing pressures than offset wells fractured with complex gel fluids. A stimulation model for oil and gas production was used to match the production history from this reservoir. The model allowed a projection of gas production based on early production from the wells and knowledge of the reservoir.

  15. Modelling and control of satellite formations

    E-Print Network [OSTI]

    Vaddi, Veera Venkata Sesha Sai

    2004-09-30T23:59:59.000Z

    as the projected circular orbit(PCO), 8 because the relative orbit is circular when projected onto the local horizontal plane, i.e., the y ¡z plane: x = ½2 sin(nt + ®0) (1.26) y = ½cos(nt + ®0) (1.27) z = ½sin(nt + ®0) (1.28) Therefore, y2 + z2 = ½2 (1.29) which... . . . . . . . . . . . . . . . . . . . . 45 2.6 Combining the E®ects of Nonlinearity and Eccentricity . 47 2.7 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 III LINEAR AND NONLINEAR CONTROL LAWS FOR FOR- MATION FLYING : : : : : : : : : : : : : : : : : : : : : : : : : 54...

  16. A simple model of the hierarchical formation of galaxies

    E-Print Network [OSTI]

    B. Hoeneisen

    2000-09-05T23:59:59.000Z

    We develop a simple, fast and predictive model of the hierarchical formation of galaxies which is in quantitative agreement with observations. Comparing simulations with observations we place constraints on the density of the universe and on the power spectrum of density fluctuations.

  17. Overexpression of Active Aurora-C Kinase Results in Cell Transformation and Tumour Formation

    E-Print Network [OSTI]

    Boyer, Edmond

    Overexpression of Active Aurora-C Kinase Results in Cell Transformation and Tumour Formation Jabbar, IFR140, Rennes, France Abstract Aurora kinases belong to a conserved family of serine/threonine kinases key regulators of cell cycle progression. Aurora-A and Aurora-B are expressed in somatic cells

  18. Vegetated Roof Water-Balance Model: Experimental and Model Results

    E-Print Network [OSTI]

    urbanization effects on the water cycle. Although there are many stormwater best management practices (BMPs (ET) and soil media water storage between storm events. Lazzarin et al. (2005) estimated that ET ratesVegetated Roof Water-Balance Model: Experimental and Model Results James A. Sherrard Jr.1

  19. Capacitive effect of cavitation in xylem conduits: results from a dynamic model

    E-Print Network [OSTI]

    Mencuccini, Maurizio

    Capacitive effect of cavitation in xylem conduits: results from a dynamic model TEEMU HÃ?LTTÃ?1. A dynamic model is presented that models xylem water potential, xylem sap flow and cavitation, taking; xylem transport. INTRODUCTION Xylem embolism formation by cavitation causes a decrease in plant

  20. Dependence of Ridge Formation on Trigger Azimuth: Correlated Emission Model

    E-Print Network [OSTI]

    Charles B. Chiu; Rudolph C. Hwa

    2009-01-05T23:59:59.000Z

    Ridge formation in near-side correlation in heavy-ion collisions is studied in the framework of a phenomenological model, called Correlated Emission Model (CEM). Successive soft emissions due to jet-medium interaction lead to the enhancement of thermal partons which follow the local flow directions. The correlation between the flow direction and the semihard parton direction is the major factor that causes the ridge formation to depend on the trigger direction relative to the reaction plane. With the use of a few parameters we have been able to reproduce the data on the ridge yields as functions of the trigger azimuthal angle for different centralities. An inside-outside asymmetry function is proposed to further probe the characteristics of the azimuthal correlation function. Insights are provided for the understanding of some detailed aspects of the centrality dependence.

  1. Crystal Structure Representations for Machine Learning Models of Formation Energies

    E-Print Network [OSTI]

    Faber, Felix; von Lilienfeld, O Anatole; Armiento, Rickard

    2015-01-01T23:59:59.000Z

    We introduce and evaluate a set of feature vector representations of crystal structures for machine learning (ML) models of formation energies of solids. ML models of atomization energies of organic molecules have been successful using a Coulomb matrix representation of the molecule. We consider three ways to generalize such representations to periodic systems: (i) a matrix where each element is related to the Ewald sum of the electrostatic interaction between two different atoms in the unit cell repeated over the lattice; (ii) an extended Coulomb-like matrix that takes into account a number of neighboring unit cells; and (iii) an Ansatz that mimics the periodicity and the basic features of the elements in the Ewald sum matrix by using a sine function of the crystal coordinates of the atoms. The representations are compared for a Laplacian kernel with Manhattan norm, trained to reproduce formation energies using a data set of 3938 crystal structures obtained from the Materials Project. For training sets consi...

  2. TWO-STAGE FRAGMENTATION FOR CLUSTER FORMATION: ANALYTICAL MODEL AND OBSERVATIONAL CONSIDERATIONS

    SciTech Connect (OSTI)

    Bailey, Nicole D.; Basu, Shantanu, E-mail: nwityk@uwo.ca, E-mail: basu@uwo.ca [Department of Physics and Astronomy, University of Western Ontario, 1151 Richmond Street, London, ON N6A 3K7 (Canada)

    2012-12-10T23:59:59.000Z

    Linear analysis of the formation of protostellar cores in planar magnetic interstellar clouds shows that molecular clouds exhibit a preferred length scale for collapse that depends on the mass-to-flux ratio and neutral-ion collision time within the cloud. We extend this linear analysis to the context of clustered star formation. By combining the results of the linear analysis with a realistic ionization profile for the cloud, we find that a molecular cloud may evolve through two fragmentation events in the evolution toward the formation of stars. Our model suggests that the initial fragmentation into clumps occurs for a transcritical cloud on parsec scales while the second fragmentation can occur for transcritical and supercritical cores on subparsec scales. Comparison of our results with several star-forming regions (Perseus, Taurus, Pipe Nebula) shows support for a two-stage fragmentation model.

  3. Structure formation and CMBR anisotropy spectrum in the inflessence model

    E-Print Network [OSTI]

    A. A. Sen; V. F. Cardone; S. Capozziello; A. Troisi

    2006-07-25T23:59:59.000Z

    The inflessence model has recently been proposed in an attempt to explain both early inflation and present day accelerated expansion within a single mechanism. The model has been successfully tested against the Hubble diagram of Type Ia Supernovae, the shift parameter, and the acoustic peak parameter. As a further mandatory test, we investigate here structure formation in the inflessence model determining the evolution of matter density contrast $\\delta \\equiv \\delta \\rho_M/\\rho_M$ in the linear regime. We compare the growth factor $D(a) \\equiv \\delta/a$ and the growth index $f(z) \\equiv d\\ln{\\delta}/d\\ln{a}$ to these same quantities for the successful concordance $\\Lambda$CDM model with a particular emphasis on the role of the inflessence parameters $(\\gamma, z_Q)$. We also evaluate the anisotropy spectrum of the cosmic microwave background radiation (CMBR) to check whether the inflessence model may be in agreement with the observations. We find that, for large values of $(\\gamma, z_Q)$, structure formation proceeds in a similar way to that in the $\\Lambda$CDM scenario, and it is also possible to nicely fit the CMBR spectrum.

  4. COMPARING MODEL RESULTS TO NATIONAL CLIMATE POLICY GOALS: RESULTS FROM THE ASIA MODELING EXERCISE

    SciTech Connect (OSTI)

    Calvin, Katherine V.; Fawcett, Allen A.; Jiang, Kejun

    2012-12-01T23:59:59.000Z

    While the world has yet to adopt a single unified policy to limit climate change, many countries and regions have adopted energy and climate policies that have implications for global emissions. In this paper, we discuss a few key policies and how they are included in a set of 24 energy and integrated assessment models that participated in the Asia Modeling Exercise. We also compare results from these models for a small set of stylized scenarios to the pledges made as part of the Copenhagen Accord and the goals stated by the Major Economies Forum. We find that the targets outlined by the United States, the European Union, Japan, and Korea require significant policy action in most of the models analyzed. For most of the models in the study, however, the goals outlined by India are met without any climate policy. The stringency of climate policy required to meet China’s Copenhagen pledges varies across models and accounting methodologies.

  5. Structure formation in inhomogeneous Early Dark Energy models

    SciTech Connect (OSTI)

    Batista, R.C. [Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte, Caixa Postal 1524, 59072-970, Natal, Rio Grande do Norte (Brazil); Pace, F., E-mail: rbatista@ect.ufrn.br, E-mail: francesco.pace@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth, PO1 3FX (United Kingdom)

    2013-06-01T23:59:59.000Z

    We study the impact of Early Dark Energy fluctuations in the linear and non-linear regimes of structure formation. In these models the energy density of dark energy is non-negligible at high redshifts and the fluctuations in the dark energy component can have the same order of magnitude of dark matter fluctuations. Since two basic approximations usually taken in the standard scenario of quintessence models, that both dark energy density during the matter dominated period and dark energy fluctuations on small scales are negligible, are not valid in such models, we first study approximate analytical solutions for dark matter and dark energy perturbations in the linear regime. This study is helpful to find consistent initial conditions for the system of equations and to analytically understand the effects of Early Dark Energy and its fluctuations, which are also verified numerically. In the linear regime we compute the matter growth and variation of the gravitational potential associated with the Integrated Sachs-Wolf effect, showing that these observables present important modifications due to Early Dark Energy fluctuations, though making them more similar to the ?CDM model. We also make use of the Spherical Collapse model to study the influence of Early Dark Energy fluctuations in the nonlinear regime of structure formation, especially on ?{sub c} parameter, and their contribution to the halo mass, which we show can be of the order of 10%. We finally compute how the number density of halos is modified in comparison to the ?CDM model and address the problem of how to correct the mass function in order to take into account the contribution of clustered dark energy. We conclude that the inhomogeneous Early Dark Energy models are more similar to the ?CDM model than its homogeneous counterparts.

  6. MODELING AND SIMULATION OF FINGERING PATTERN FORMATION IN A COMBUSTION MODEL

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    MODELING AND SIMULATION OF FINGERING PATTERN FORMATION IN A COMBUSTION MODEL LINA HU, CLAUDE-MICHEL BRAUNER, JIE SHEN, AND GREGORY I. SIVASHINSKY Abstract. We consider a model of gas-solid combustion background. Combustion is basically a process of fast oxidation accompanied by substantial heat release

  7. TOP-DOWN MODELING; PRACTICAL, FAST TRACK, RESERVOIR SIMULATION & MODELING FOR SHALE FORMATIONS Shahab D. Mohaghegh1 & Grant Bromhal2

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    development in the oil and gas industry and is being used on some shale formations. BAKKEN SHALE MuchTOP-DOWN MODELING; PRACTICAL, FAST TRACK, RESERVOIR SIMULATION & MODELING FOR SHALE FORMATIONS based on measure data, called Top-Down, Intelligent Reservoir Modeling for the shale formations

  8. First Structure Formation: I. Primordial Star Forming Regions in hierarchical models

    E-Print Network [OSTI]

    Tom Abel; Peter Anninos; Michael L. Norman; Yu Zhang

    1997-05-17T23:59:59.000Z

    We investigate the possibility of very early formation of primordial star clusters from high-\\sigma perturbations in cold dark matter dominated structure formation scenarios. For this we have developed a powerful 2-level hierarchical cosmological code with a realistic and robust treatment of multi-species primordial gas chemistry, paying special attention to the formation and destruction of hydrogen molecules, non-equilibrium ionization, and cooling processes. We performed 3-D simulations at small scales and at high redshifts and find that, analogous to simulations of large scale structure, a complex system of filaments, sheets, and spherical knots at the intersections of filaments form. On the mass scales covered by our simulations (5x10^5 - 1x10^9\\Ms) that collapse at redshifts z>25, we find that only at the spherical knots can enough H2 be formed (n_{H_2}/n_H > 5x10^-4) to cool the gas appreciably. Quantities such as the time dependence of the formation of H2 molecules, the final H2 fraction, and central densities from the simulations are compared to the theoretical predictions of Abel (1995) and Tegmark et al. (1997) and found to agree remarkably well. Comparing the 3-D results to an isobaric collapse model we further discuss the possible implications of the extensive merging of small structure that is inherent in hierarchical models. Typically only 5-8% percent of the total baryonic mass in the collapsing structures is found to cool significanlty. Assuming the Padoan (1995) model for star formation our results would predict the first stellar systems to be as small as ~30\\Ms. Some implications for primordial globular cluster formation scenarios are also discussed.

  9. Experimental and modeling investigation of aromatic and polycyclic aromatic hydrocarbon formation in a premixed ethylene flame

    SciTech Connect (OSTI)

    Castaldi, M.J.; Marinov, N.M.; Melius, C.F. [and others

    1996-02-01T23:59:59.000Z

    Experimental and detailed chemical kinetic modeling has been performed to investigate aromatic and polyaromatic hydrocarbon formation pathways in a rich, sooting, ethylene-oxygen-argon premixed flame. An atmospheric pressure, laminar flat flame operated at an equivalence ratio of 2.5 was used to acquire experimental data for model validation. Gas composition analysis was conducted by an on-line gas chromatograph/mass spectrometer (GC/MS) technique. Measurements were made in the flame and post-flame zone for a number of low molecular weight species, aliphatics, aromatics and polycyclic aromatic hydrocarbons (PAHs) ranging from two to five-aromatic fused rings. The modeling results show the key reaction sequences leading to aromatic and polycyclic aromatic hydrocarbon growth involve the combination of resonantly stabilized radicals. In particular, propargyl and 1-methylallenyl combination reactions lead to benzene and methyl substituted benzene formation, while polycyclic aromatics are formed from cyclopentadienyl radicals and fused rings that have a shared C{sub 5} side structure. Naphthalene production through the reaction step of cyclopentadienyl self-combination and phenanthrene formation from indenyl and cyclopentadienyl combination were shown to be important in the flame modeling study. The removal of phenyl by O{sub 2} leading to cyclopentadienyl formation is expected to play a pivotal role in the PAH or soot precursor growth process under fuel-rich oxidation conditions.

  10. Uncalibrated Building Energy Simulation Modeling Results

    E-Print Network [OSTI]

    Ahmad, M.; Culp, C.H.

    for the Level 1 and Level 2 models with measured data for WERC (2004 post-commissioning data). ESL-PA-06-10-01 VOLUME 12, NUMBER 4, OCTOBER 2006 1151 Figure 6. Comparison of simulated daily total energy consumption for the Level 1 and Level 2 models with 1999...,450 m2]), the simulation using 1999 data underestimates the energy use in all categories except the whole building electrical usage. Table 3 identifies the magnitude of these discrepancies for a full year’s consumption. The Level 1 model actually per...

  11. Formation of molecular hydrogen on analogues of interstellar dust grains: experiments and modelling

    E-Print Network [OSTI]

    Gianfranco Vidali; Joe Roser; Giulio Manico; Valerio Pirronello; Hagai B. Perets; Ofer Biham

    2005-04-25T23:59:59.000Z

    Molecular hydrogen has an important role in the early stages of star formation as well as in the production of many other molecules that have been detected in the interstellar medium. In this review we show that it is now possible to study the formation of molecular hydrogen in simulated astrophysical environments. Since the formation of molecular hydrogen is believed to take place on dust grains, we show that surface science techniques such as thermal desorption and time-of-flight can be used to measure the recombination efficiency, the kinetics of reaction and the dynamics of desorption. The analysis of the experimental results using rate equations gives useful insight on the mechanisms of reaction and yields values of parameters that are used in theoretical models of interstellar cloud chemistry.

  12. Modeling the formation of boron carbide particles in an aerosol flow reactor

    SciTech Connect (OSTI)

    Xiong, Y.; Pratsinis, S.E. (Dept. of Chemical Engineering, Center for Aerosol Processes, Univ. of Cincinnati, Cincinnati, OH (United States)); Weimer, A.W. (Ceramics and Advanced Materials Research, Dow Chemical U.S.A., Midland, MI (United States))

    1992-11-01T23:59:59.000Z

    In this paper the formation of submicron crystals of boron carbide (B[sub 4]C) by coagulation and sintering by the rapid carbothermal reduction of intimately mixed carbon-boron oxide powders in an aerosol flow reactor at temperatures above the boiling point of boron oxide is investigated. High heating rates (10[sup 5] K/s) force rapid evaporation of boron oxide and suboxides from the precursor powder, resulting in its rupture and formation of boron carbide molecular clusters that grow to macroscopic particles by coagulation. Consequently, the formation and growth of B[sub 4]C particles are described by simultaneous interparticle collision and coalescence using a two-dimensional particle-size distribution model that traces the evolution of both size and shape characteristics of the particles through their volume and surface area. In addition to the coagulation term, the governing population balance equation includes a coalescence contribution based on B[sub 4]C sintering law.

  13. $J/?$ suppression in the threshold model and QGP formation time

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2007-09-03T23:59:59.000Z

    In the QGP motivated threshold model, in addition to the normal nuclear absorption, $J/\\psi$'s are subjected to an additional "anomalous" suppression. We have analysed the recently published PHENIX data on the participant number dependence of the nuclear modification factor for $J/\\psi$'s in Au+Au collisions and extracted the anomalous suppression required to explain the data. At mid rapidity $J/\\psi$'s are anomalously suppressed only above a threshold density $n_c$=3.73 fm$^{-2}$. The forward rapidity data on the otherhand require that $J/\\psi$'s are continuously "anomalously" suppressed. The analysis strongly indicate that in mid rapidity $J/\\psi$'s are suppressed in a deconfined medium. Using the PHENIX data on the participant number dependence of the Bjorken energy density, we have also estimated the QGP formation time. For critical temperature $T_c$=192 MeV, estimated QGP formation time ranges between 0.06-0.08 fm/c.

  14. Reservoir Characterization and Modeling of the Glorieta and the Clearfork Formations, Monahans Field, Permian Basin, Texas

    E-Print Network [OSTI]

    Yeatman, Ryan Yeatman

    2012-10-19T23:59:59.000Z

    difficult. The facies model indicates that during deposition, a tectonically uplifted area (island) influenced sedimentation and also shows that the Upper Clearfork Formation is mainly subtidal facies and the Glorieta Formation consists mainly of tidal flat...

  15. Star Formation along the Hubble sequence: results from a new Halpha Galaxy Survey

    E-Print Network [OSTI]

    Neville S. Shane; Phil A. James

    2001-12-07T23:59:59.000Z

    We are conducting a large survey of star formation within ~400 nearby spiral and irregular galaxies through imaging of the Halpha emission. We present here some of our first results from 104 of the galaxies in our sample, investigating the variation of SFR and Halpha EWs along the Hubble sequence for these galaxies. We find a strong dependence of SFR on Hubble type, peaking for Sbc galaxies, but with large dispersions within each type. There is a possible dependence of SFR on bar presence, but none on group membership. There is an increase in EWs for later Hubble types, but with large dispersions within each type. We find no dependence of EW on bar presence, group membership or on absolute magnitude.

  16. Direct containment heating: Surtsey test results and models

    SciTech Connect (OSTI)

    Tarbell, W.W.; Nichols, R.T.; Pilch, M.; Brockmann, J.E.; Powers, D.A.

    1988-08-01T23:59:59.000Z

    Direct containment heating is one of the processes that can lead to containment rupture early in a severe reactor accident. The origins and the current understanding of this process are surveyed. Three issues arise in connection with direct containment heating -- threats to containment integrity posed by transfer of energy to the containment atmosphere from dispersed core debris or the generation of hydrogen by reactions of core debris with steam, and the formation of radioactive aerosols available for release from the plant should containment integrity be lost. The two threats to containment integrity have different characteristics. Energy exchange between core debris and the atmosphere depends on the long range dispersal of the debris and the atmosphere depends on the long range dispersal of the debris and can be affected by interactions of the debris with structures and co-dispersed water. Hydrogen generation is dependent on the detailed flows of debris and steam within and near the reactor cavity. Results of four experiments in the Surtsey test facility to explore energy exchange with the atmosphere are presented. These experiments suggest ''single particle'' models of direct heating over-predict the threat to containment integrity and that debris/structure interactions can enhance heating of the containment atmosphere. Results of test to establish the low pressure cut-off to direct heating are reported. 23 refs., 2 figs., 1 tab.

  17. Asymptotic and uncertainty analyses of a phase field model for void formation under irradiation

    SciTech Connect (OSTI)

    Nan Wang; Srujan Rokkam; Thomas Hochrainer; Michael Pernice; Anter El-Azab

    2014-06-01T23:59:59.000Z

    We perform asymptotic analysis and uncertainty quantification of a phase field model for void formation and evolution in materials subject to irradiation. The parameters of the phase field model are obtained in terms of the underlying material specific quantities by matching the sharp interface limit of the phase field model with the corresponding sharp interface theory for void growth. To evaluate the sensitivity of phase field simulations to uncertainties in input parameters we quantify the predictions using the stochastic collocation method. Uncertainties arising from material parameters are investigated based on available experimental and atomic scale data. The results of our analysis suggest that the uncertainty in the formation and migration energies of vacancies are found to have a strong influence on the void volume fraction (or porosity). In contrast, the uncertainty resulting from the void surface energy has minimal affect. The analysis also shows that the model is consistent in the sense that its predictions do not drastically change as a result of small variations of the model input parameters.

  18. Galaxy Formation & Dark Matter Modelling in the Era of the Square Kilometre Array

    E-Print Network [OSTI]

    Power, C; Qin, B; Baugh, C M; Cunnama, D; Fu, J; Kim, H S; Lacey, C G; Li, L; Obreschkow, D; Wang, J; Wang, Y; Zhu, M

    2015-01-01T23:59:59.000Z

    Theoretical galaxy formation models are an established and powerful tool for interpreting the astrophysical significance of observational data, particularly galaxy surveys. Such models have been utilised with great success by optical surveys such as 2dFGRS and SDSS, but their application to radio surveys of cold gas in galaxies has been limited. In this chapter we describe recent developments in the modelling of the cold gas properties in the models, and how these developments are essential if they are to be applied to cold gas surveys of the kind that will be carried out with the SKA. By linking explicitly a galaxy's star formation rate to the abundance of molecular hydrogen in the galaxy rather than cold gas abundance, as was assumed previously, the latest models reproduce naturally many of the global atomic and molecular hydrogen properties of observed galaxies. We review some of the key results of the latest models and highlight areas where further developments are necessary. We discuss also how model pre...

  19. Modelling of the bead formation during multi pass hybrid laser/gas metal arc welding

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    - 1 - Modelling of the bead formation during multi pass hybrid laser/gas metal arc welding Olivier dimensional finite element model has been developed to simulate weld bead formation in multi pass hybrid laser/gas metal arc welding. The model considers both a gas metal arc welding (GMAW) electrode and a laser beam

  20. Measurements and modeling of soot formation and radiation in microgravity jet diffusion flames

    SciTech Connect (OSTI)

    Ku, J.C.; Tong, L. [Wayne State Univ., Detroit, MI (United States). Mechanical Engineering Dept.; Greenberg, P.S. [NASA Lewis Research Center, Cleveland, OH (United States). Microgravity Combustion Branch

    1996-12-31T23:59:59.000Z

    This is a computational and experimental study for soot formation and radiative heat transfer in jet diffusion flames under normal gravity (1-g) and microgravity (0-g) conditions. Instantaneous soot volume fraction maps are measured using a full-field imaging absorption technique developed by the authors. On modeling, the authors have coupled flame structure and soot formation models with detailed radiation transfer calculations. Favre-averaged boundary layer equations with a k-e-g turbulence model are used to predict the flow field, and a conserved scalar approach with an assumed {beta}-pdf are used to predict gaseous species mole fraction. Scalar transport equations are used to describe soot volume fraction and number density distributions, with formation and oxidation terms modeled by one-step rate equations and thermophoretic effects included. An energy equation is included to couple flame structure and radiation analyses through iterations, neglecting turbulence-radiation interactions. The YIX solution for a finite cylindrical enclosure is used for radiative heat transfer calculations. The spectral absorption coefficient for soot aggregates is calculated from the Rayleigh solution using complex refractive index data from a Drude-Lorentz model. The exponential-wide-band model is used to calculate the spectral absorption coefficient for H{sub 2}O and CO{sub 2}. Predicted soot volume fraction and temperature results agree well with published data for a normal gravity co-flow laminar flames and turbulent jet flames. Predicted soot volume fraction results also agree with the data for 1-g and 0-g laminar jet flames as well as 1-g turbulent jet flames.

  1. Modeling of Nonuniform Degradation in Large-Format Li-ion Batteries (Presentation)

    SciTech Connect (OSTI)

    Smith, K.; Kim, G. H.; Pesaran, A.

    2009-05-01T23:59:59.000Z

    Study of impacts of large-format cell design features on battery useful life to improve battery engineering models, including both realistic geometry and physics.

  2. Experimental results of water film formation on various fuel forms from a fire suppression system

    SciTech Connect (OSTI)

    Ross, R.H.; Davis, J.R.

    1993-12-31T23:59:59.000Z

    The purpose of the study was to determine the thickness and coverage of water film formations on various materials during fire sprinkler deluge. An exhaustive literature search revealed that no applicable research data exists that governs water film formations from fire protection systems. Therefore, a controlled, infield, mockup was created to predict the thickness and coverage of water film on fissile material forms. This paper discusses the background, experimental procedure and the characterization of these water films.

  3. The metal enrichment of elliptical galaxies in hierarchical galaxy formation models

    E-Print Network [OSTI]

    Masahiro Nagashima; Cedric G. Lacey; Takashi Okamoto; Carlton M. Baugh; Carlos S. Frenk; Shaun Cole

    2005-07-14T23:59:59.000Z

    We investigate the metal enrichment of elliptical galaxies in the framework of hierarchical models of galaxy formation. The semi-analytical model we use in this Letter, which has been used to study the metal enrichment of the intracluster medium (ICM) by Nagashima et al., includes the effects of flows of gas and metals both into and out of galaxies and the processes of metal enrichment due to both type Ia and type II supernovae. We adopt a solar neighbourhood IMF for star formation in discs, but consider models in which starbursts have either a solar neighbourhood IMF or a top-heavy IMF. We find that the alpha-element abundance in ellipticals is consistent with observed values only if the top-heavy IMF is used. This result is consistent with our previous study on the metal enrichment of the ICM. We also discuss the abundance ratio of alpha elements to iron as a function of velocity dispersion and metallicity. We find that models with a top-heavy IMF match the alpha/Fe ratios observed in typical L_* ellipticals, but none of the models reproduce the observed increase of alpha/Fe with velocity dispersion.

  4. Modeling and simulation of HVAC Results in EnergyPlus

    E-Print Network [OSTI]

    LBNL-5564E Modeling and simulation of HVAC Results in EnergyPlus Mangesh Basarkar, Xiufeng Pang;MODELING AND SIMULATION OF HVAC FAULTS IN ENERGYPLUS Mangesh Basarkar, Xiufeng Pang, Liping Wang, Philip

  5. Results from Development of Model Specifications for Multifamily Energy Retrofits

    SciTech Connect (OSTI)

    Brozyna, K.

    2012-08-01T23:59:59.000Z

    Specifications, modeled after CSI MasterFormat, provide the trade contractors and builders with requirements and recommendations on specific building materials, components and industry practices that comply with the expectations and intent of the requirements within the various funding programs associated with a project. The goal is to create a greater level of consistency in execution of energy efficiency retrofits measures across the multiple regions a developer may work. IBACOS and Mercy Housing developed sample model specifications based on a common building construction type that Mercy Housing encounters.

  6. MODELING OF POROSITY FORMATION IN ALUMINUM ALLOYS Kent D. Carlson1

    E-Print Network [OSTI]

    Beckermann, Christoph

    MODELING OF POROSITY FORMATION IN ALUMINUM ALLOYS Kent D. Carlson1 , Zhiping Lin1 , Christoph Aachen, Germany Keywords: porosity, aluminum alloys, hydrogen diffusion Abstract A new approach based illustrate that the model captures important phenomena observed in porosity formation in aluminum alloys

  7. Modeling the Effect of Finite-Rate Hydrogen Diffusion on Porosity Formation in Aluminum Alloys

    E-Print Network [OSTI]

    Beckermann, Christoph

    Modeling the Effect of Finite-Rate Hydrogen Diffusion on Porosity Formation in Aluminum Alloys KENT of hydrogen in the melt is developed to predict pore formation during the solidification of aluminum alloys by Lee et al.[3] Recent examples of porosity models for aluminum alloy castings, including the effect

  8. Experimental results of water film formation on various fuel forms from a fire suppression system

    SciTech Connect (OSTI)

    Ross, R.H.; Davis, J.R.

    1994-12-31T23:59:59.000Z

    The purpose of the study was to determine the thickness and coverage of water film formations on various materials during fire sprinkler deluge. The primary criticality safety concern with automatic fire suppression systems is the increased amount of water that a film adds to the interstitial volume of an array per unit time. An exhaustive literature search revealed that no applicable research data exist that govern water film formations from fire protection systems. Therefore, a controlled, infield, mockup was created to predict the thickness and coverage of water film on fissile material forms. This paper discusses the background, experimental procedure, and the characterization of these water films.

  9. Update On The Wholesale Electricity Price Forecast & Modeling Results

    E-Print Network [OSTI]

    ,877 Replacement #12;CO2 Emission Modeling § The AURORAxmp® electric market model calculates CO2 emission) Assumptions § CO2 emission modeling § Base Case Results § Scenario/Sensitivities § Emission Projections Database ­ eGRID 2012 Year 2009 ­ Emissions, including CO2, are estimated using information from various

  10. The Conditions for Star Formation at Low Metallicity: Results from the LMC

    E-Print Network [OSTI]

    B. G. Elmegreen; J. Palous; J. M. Oliveira; J. Th Van Loon; Stanimirovi? S

    2006-01-01T23:59:59.000Z

    Abstract. We present our recent work on the conditions under which star formation occurs in a metal-poor environment, the Large Magellanic Cloud ([Fe/H] ? ?0.4). Water masers are used as beacons of the current star formation in Hii regions. Comparing their location with the dust morphology imaged with the Spitzer Space Telescope, and additional H? imaging and groundbased near-infrared observations, we conclude that the LMC environment seems favourable to sequential star formation triggered by massive star feedback (Oliveira et al. 2006). Good examples of this are 30 Doradus and N 113. There are also Hii regions, such as N 105A, where feedback may not be responsible for the current star formation although the nature of one young stellar object (YSO) suggests that feedback may soon start making an impact. The chemistry in one YSO hints at a stronger influence from irradiation effects in a metal-poor environment where shielding by dust is suppressed (van Loon 2005).

  11. MODELING THE FORMATION OF GIANT PLANET CORES. I. EVALUATING KEY PROCESSES

    SciTech Connect (OSTI)

    Levison, Harold F. [Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); Thommes, Edward [Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1 (Canada); Duncan, Martin J. [Department of Physics, Queen's University, Kingston, Ontario K7L 3N6 (Canada)], E-mail: hal@boulder.swri.edu

    2010-04-15T23:59:59.000Z

    One of the most challenging problems we face in our understanding of planet formation is how Jupiter and Saturn could have formed before the solar nebula dispersed. The most popular model of giant planet formation is the so-called core accretion model. In this model a large planetary embryo formed first, mainly by two-body accretion. This is then followed by a period of inflow of nebular gas directly onto the growing planet. The core accretion model has an Achilles heel, namely the very first step. We have undertaken the most comprehensive study of this process to date. In this study, we numerically integrate the orbits of a number of planetary embryos embedded in a swarm of planetesimals. In these experiments, we have included a large number of physical processes that might enhance accretion. In particular, we have included (1) aerodynamic gas drag, (2) collisional damping between planetesimals, (3) enhanced embryo cross sections due to their atmospheres, (4) planetesimal fragmentation, and (5) planetesimal-driven migration. We find that the gravitational interaction between the embryos and the planetesimals leads to the wholesale redistribution of material-regions are cleared of material and gaps open near the embryos. Indeed, in 90% of our simulations without fragmentation, the region near those embryos is cleared of planetesimals before much growth can occur. Thus, the widely used assumption that the surface density distribution of planetesimals is smooth can lead to misleading results. In the remaining 10% of our simulations, the embryos undergo a burst of outward migration that significantly increases growth. On timescales of {approx}10{sup 5} years, the outer embryo can migrate {approx}6 AU and grow to roughly 30 M {sub +}. This represents a largely unexplored mode of core formation. We also find that the inclusion of planetesimal fragmentation tends to inhibit growth except for a narrow range of fragment migration rates.

  12. Modeling the role of relationship fading and breakup in social network formation

    E-Print Network [OSTI]

    Murase, Yohsuke; Török, János; Kertész, János; Kaski, Kimmo

    2015-01-01T23:59:59.000Z

    In social networks of human individuals, social relationships do not necessarily last forever as they can either fade gradually with time, resulting in link aging, or terminate abruptly, causing link deletion, as even old friendships may cease. In this paper, we study a social network formation model where we introduce several ways by which a link termination takes place. If we adopt the link aging, we get a more modular structure with more homogeneously distributed link weights within communities than when link deletion is used. By investigating distributions and relations of various network characteristics, we find that the empirical findings are better reproduced with the link deletion model. This indicates that link deletion plays a more prominent role in organizing social networks than link aging.

  13. Reuse of Verification Results Conditional Model Checking, Precision Reuse,

    E-Print Network [OSTI]

    Beyer, Dirk

    further verification runs of the system; information about the level of abstraction in the abstract modelReuse of Verification Results Conditional Model Checking, Precision Reuse, and Verification checker which parts of the system should be verified; thus, later verification runs can use the output

  14. Energy-aware scheduling: models and complexity results

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Energy-aware scheduling: models and complexity results Guillaume Aupy (1st year PhD student) LIP several energy-aware scheduling algorithms whose design is optimized for different speed models. Dynamic plans. I. INTRODUCTION Energy-aware scheduling has proven an important issue in the past decade, both

  15. A Theoretical Model of Pattern Formation in Coral Reefs

    E-Print Network [OSTI]

    the behavior of perturba- tions in an initially uniform model system. Alan Turing was one of the first

  16. Modeling Coupled Processes in Clay Formations for Radioactive Waste Disposal

    E-Print Network [OSTI]

    Liu, Hui-Hai

    2010-01-01T23:59:59.000Z

    International Workshop on Geomechanics, hydromechanical andflow, heat transport and geomechanics, by linking the twotransport modeling and geomechanics using the reactive

  17. Modeling Coupled Processes in Clay Formations for Radioactive Waste Disposal

    E-Print Network [OSTI]

    Liu, Hui-Hai

    2010-01-01T23:59:59.000Z

    and the future path of diagenesis have important effects onthe basic basin model for diagenesis. Therefore, some method

  18. World oil futures: results from the OILTANK model presented at the energy modeling forum

    SciTech Connect (OSTI)

    Ervik, L.K.; Johannessen, O.; Nunn, D.W.

    1980-09-01T23:59:59.000Z

    This report gives results from the OILTANK simulation model presented at the Energy Modeling Forum on future world oil price. 12 scenarios are presented.

  19. NEPHELINE FORMATION STUDY FOR SLUDGE BATCH 4: PHASE 3 EXPERIMENTAL RESULTS

    SciTech Connect (OSTI)

    Fox, K

    2006-05-01T23:59:59.000Z

    This Phase 3 study was undertaken to complement the previous phases of the nepheline formation studies1, 2 by continuing the investigation into the ability of the nepheline discriminator to predict the occurrence of nepheline crystallization in Sludge Batch 4 (SB4) glasses and into the impact of such phases on the durability of the SB4 glasses. The Phase 3 study had two primary objectives. The first was to continue to demonstrate the ability of the discriminator value to adequately predict the nepheline formation potential for specific glass systems of interest. The second was to generate additional data that have a high probability of supporting the SB4 variability study. To support these two objectives, sixteen glasses were selected based on the most recent SB4 compositional projection, Case 15C Blend 1.3 Four different frits were included, based on previous assessments of projected operating windows and melt rate,4, 5 with four WLs selected for each frit. Eight of these frit-sludge combinations covered WLs which tightly bound the nepheline discriminator value of 0.62, with the intent of refining this value to a level of confidence where it can be incorporated into offline administrative controls and/or the Process Composition Control System (PCCS) to support Slurry Mix Evaporator (SME) acceptability decisions. The remaining eight frit-sludge combinations targeted lower WLs (35 and 40%) and were prepared and analyzed to contribute needed data to the ComPro database6 to support a potential variability study for SB4.

  20. Influence of active sites organisation on calcium carbonate formation at model biomolecular interfaces

    E-Print Network [OSTI]

    Hell, Stefan W.

    aqueous CaCO3 was observed in situ by Brewster angle microscopy, where CaCO3 domains appear bright. Striking differences in kinetics and extent of CaCO3 formation are observed between monolayers containing-carrageenan in the subphase as a further active component resulted in partial inhibition of CaCO3 formation. # 2004 Elsevier B

  1. Melt coolability modeling and comparison to MACE test results

    SciTech Connect (OSTI)

    Farmer, M.T.; Sienicki, J.J.; Spencer, B.W.

    1992-04-01T23:59:59.000Z

    An important question in the assessment of severe accidents in light water nuclear reactors is the ability of water to quench a molten corium-concrete interaction and thereby terminate the accident progression. As part of the Melt Attack and Coolability Experiment (MACE) Program, phenomenological models of the corium quenching process are under development. The modeling approach considers both bulk cooldown and crust-limited heat transfer regimes, as well as criteria for the pool thermal hydraulic conditions which separate the two regimes. The model is then compared with results of the MACE experiments.

  2. Melt coolability modeling and comparison to MACE test results

    SciTech Connect (OSTI)

    Farmer, M.T.; Sienicki, J.J.; Spencer, B.W.

    1992-01-01T23:59:59.000Z

    An important question in the assessment of severe accidents in light water nuclear reactors is the ability of water to quench a molten corium-concrete interaction and thereby terminate the accident progression. As part of the Melt Attack and Coolability Experiment (MACE) Program, phenomenological models of the corium quenching process are under development. The modeling approach considers both bulk cooldown and crust-limited heat transfer regimes, as well as criteria for the pool thermal hydraulic conditions which separate the two regimes. The model is then compared with results of the MACE experiments.

  3. Constraining hybrid inflation models with WMAP three-year results

    SciTech Connect (OSTI)

    Cardoso, Antonio [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 2EG (United Kingdom)

    2007-01-15T23:59:59.000Z

    We reconsider the original model of quadratic hybrid inflation in light of the WMAP three-year results and study the possibility of obtaining a spectral index of primordial density perturbations, n{sub s}, smaller than 1 from this model. The original hybrid inflation model naturally predicts n{sub s}{>=}1 in the false vacuum dominated regime but it is also possible to have n{sub s}<1 when the quadratic term dominates. We therefore investigate whether there is also an intermediate regime compatible with the latest constraints, where the scalar field value during the last 50 e-folds of inflation is less than the Planck scale.

  4. Modeling of NO{sub x} release from a single coal particle. 2: Formation of NO from char-nitrogen

    SciTech Connect (OSTI)

    Visona, S.P.; Stanmore, B.R. [Univ. of Queensland, Brisbane, Queensland (Australia)] [Univ. of Queensland, Brisbane, Queensland (Australia)

    1996-08-01T23:59:59.000Z

    Computational modeling has been carried out to study the formation of nitric oxide during the combustion of a single spherical char particle. Combustion conditions are representative of pulverized coal in the temperature range 1,250 to 1,750 K. The model is a generalized mechanistic model with nitric oxide or HCN being released directly from the char N. Homogeneous gas-phase reactions of NO occur within the particle, as well as heterogeneous NO reduction on the char`s surface. Intrinsic rate kinetics are used to model the char combustion, while the NO reduction kinetics are chosen from the literature. The model was tested against experimental results for coal chars found in the literature and the authors` own work with petroleum coke. Modeling suggests that two mechanisms are possible for the conversion of char N to NO at high temperatures: char N goes completely to NO and is subsequently reduced on the char`s surface; or char N goes completely to HCN and is oxidized and reduced in the atmosphere external to the particle. Both approaches produce realistic results when applied to a laminar flow computational fluid flow/heat transfer model of a drop tube furnace. The model describes NO formation at high temperatures and does not consider N{sub 2}O reactions which are important at fluidized bed temperatures.

  5. Final Report - Modeling Results For the ITER Cryogenic Fore Pump

    SciTech Connect (OSTI)

    Pfotenhauer, John M; Zhang, Dongsheng

    2014-03-31T23:59:59.000Z

    A numerical model characterizing the operation of a cryogenic fore-pump (CFP) for ITER has been developed at the University of Wisconsin – Madison during the period from March 15, 2011 through June 30, 2014. The purpose of the ITER-CFP is to separate hydrogen isotopes from helium gas, both making up the exhaust components from the ITER reactor. The model explicitly determines the amount of hydrogen that is captured by the supercritical-helium-cooled pump as a function of the inlet temperature of the supercritical helium, its flow rate, and the inlet conditions of the hydrogen gas flow. Furthermore the model computes the location and amount of hydrogen captured in the pump as a function of time. Throughout the model’s development, and as a calibration check for its results, it has been extensively compared with the measurements of a CFP prototype tested at Oak Ridge National Lab. The results of the model demonstrate that the quantity of captured hydrogen is very sensitive to the inlet temperature of the helium coolant on the outside of the cryopump. Furthermore, the model can be utilized to refine those tests, and suggests methods that could be incorporated in the testing to enhance the usefulness of the measured data.

  6. Planck 2013 results. XXX. Cosmic infrared background measurements and implications for star formation

    E-Print Network [OSTI]

    Ade, P A R; Armitage-Caplan, C; Arnaud, M; Ashdown, M; Atrio-Barandela, F; Aumont, J; Baccigalupi, C; Banday, A J; Barreiro, R B; Bartlett, J G; Battaner, E; Benabed, K; Benoît, A; Benoit-Lévy, A; Bernard, J -P; Bersanelli, M; Bethermin, M; Bielewicz, P; Blagrave, K; Bobin, J; Bock, J J; Bonaldi, A; Bond, J R; Borrill, J; Bouchet, F R; Boulanger, F; Bridges, M; Bucher, M; Burigana, C; Butler, R C; Cardoso, J -F; Catalano, A; Challinor, A; Chamballu, A; Chen, X; Chiang, H C; Chiang, L -Y; Christensen, P R; Church, S; Clements, D L; Colombi, S; Colombo, L P L; Couchot, F; Coulais, A; Crill, B P; Curto, A; Cuttaia, F; Danese, L; Davies, R D; Davis, R J; de Bernardis, P; de Rosa, A; de Zotti, G; Delabrouille, J; Delouis, J -M; Désert, F -X; Dickinson, C; Diego, J M; Dole, H; Donzelli, S; Doré, O; Douspis, M; Dupac, X; Efstathiou, G; Enßlin, T A; Eriksen, H K; Finelli, F; Forni, O; Frailis, M; Franceschi, E; Galeotta, S; Ganga, K; Ghosh, T; Giard, M; Giraud-Héraud, Y; González-Nuevo, J; Górski, K M; Gratton, S; Gregorio, A; Gruppuso, A; Hansen, F K; Hanson, D; Harrison, D; Helou, G; Henrot-Versillé, S; Hernández-Monteagudo, C; Herranz, D; Hildebrandt, S R; Hivon, E; Hobson, M; Holmes, W A; Hornstrup, A; Hovest, W; Huffenberger, K M; Jaffe, A H; Jaffe, T R; Jones, W C; Juvela, M; Kalberla, P; Keihänen, E; Kerp, J; Keskitalo, R; Kisner, T S; Kneissl, R; Knoche, J; Knox, L; Kunz, M; Kurki-Suonio, H; Lacasa, F; Lagache, G; Lähteenmäki, A; Lamarre, J -M; Langer, M; Lasenby, A; Laureijs, R J; Lawrence, C R; Leonardi, R; León-Tavares, J; Lesgourgues, J; Liguori, M; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Macías-Pérez, J F; Maffei, B; Maino, D; Mandolesi, N; Maris, M; Marshall, D J; Martin, P G; Martínez-González, E; Masi, S; Matarrese, S; Matthai, F; Mazzotta, P; Melchiorri, A; Mendes, L; Mennella, A; Migliaccio, M; Mitra, S; Miville-Deschênes, M -A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Munshi, D; Murphy, J A; Naselsky, P; Nati, F; Natoli, P; Netterfield, C B; Nørgaard-Nielsen, H U; Noviello, F; Novikov, D; Novikov, I; Osborne, S; Oxborrow, C A; Paci, F; Pagano, L; Pajot, F; Paladini, R; Paoletti, D; Partridge, B; Pasian, F; Patanchon, G; Perdereau, O; Perotto, L; Perrotta, F; Piacentini, F; Piat, M; Pierpaoli, E; Pietrobon, D; Plaszczynski, S; Pointecouteau, E; Polenta, G; Ponthieu, N; Popa, L; Poutanen, T; Pratt, G W; Prézeau, G; Prunet, S; Puget, J -L; Rachen, J P; Reach, W T; Rebolo, R; Reinecke, M; Remazeilles, M; Renault, C; Ricciardi, S; Riller, T; Ristorcelli, I; Rocha, G; Rosset, C; Roudier, G; Rowan-Robinson, M; Rubiño-Martín, J A; Rusholme, B; Sandri, M; Santos, D; Savini, G; Scott, D; Seiffert, M D; Serra, P; Shellard, E P S; Spencer, L D; Starck, J -L; Stolyarov, V; Stompor, R; Sudiwala, R; Sunyaev, R; Sureau, F; Sutton, D; Suur-Uski, A -S; Sygnet, J -F; Tauber, J A; Tavagnacco, D; Terenzi, L; Toffolatti, L; Tomasi, M; Tristram, M; Tucci, M; Tuovinen, J; Türler, M; Valenziano, L; Valiviita, J; Van Tent, B; Vielva, P; Villa, F; Vittorio, N; Wade, L A; Wandelt, B D; Welikala, N; White, M; White, S D M; Winkel, B; Yvon, D; Zacchei, A; Zonca, A

    2014-01-01T23:59:59.000Z

    We present new measurements of CIB anisotropies using Planck. Combining HFI data with IRAS, the angular auto- and cross frequency power spectrum is measured from 143 to 3000 GHz, and the auto-bispectrum from 217 to 545 GHz. The total areas used to compute the CIB power spectrum and bispectrum are about 2240 and 4400 deg^2, respectively. After careful removal of the contaminants, and a complete study of systematics, the CIB power spectrum and bispectrum are measured with unprecedented signal to noise ratio from angular multipoles ell~150 to 2500, and ell~130 to 1100, respectively. Two approaches are developed for modelling CIB power spectrum anisotropies. The first approach takes advantage of the unique measurements by Planck at large angular scales, and models only the linear part of the power spectrum, with a mean bias of dark matter halos hosting dusty galaxies at a given redshift weighted by their contribution to the emissivities. The second approach is based on a model that associates star-forming galaxie...

  7. Antibound States and Halo Formation in the Gamow Shell Model

    E-Print Network [OSTI]

    N. Michel; W. Nazarewicz; M. Ploszajczak; J. Rotureau

    2006-09-07T23:59:59.000Z

    The open quantum system formulation of the nuclear shell model, the so-called Gamow Shell Model (GSM), is a multi-configurational SM that employs a single-particle basis given by the Berggren ensemble consisting of Gamow states and the non-resonant continuum of scattering states. The GSM is of particular importance for weakly bound/unbound nuclear states where both many-body correlations and the coupling to decay channels are essential. In this context, we investigate the role of l=0 antibound (virtual) neutron single-particle states in the shell model description of loosely bound wave functions, such as the ground state wave function of a halo nucleus 11Li.

  8. Shock-Wave Heating Model for Chondrule Formation: Prevention of Isotopic Fractionation

    E-Print Network [OSTI]

    Hitoshi Miura; Taishi Nakamoto

    2006-07-03T23:59:59.000Z

    Chondrules are considered to have much information on dust particles and processes in the solar nebula. It is naturally expected that protoplanetary disks observed in present star forming regions have similar dust particles and processes, so study of chondrule formation may provide us great information on the formation of the planetary systems. Evaporation during chondrule melting may have resulted in depletion of volatile elements in chondrules. However, no evidence for a large degree of heavy-isotope enrichment has been reported in chondrules. In order to meet this observed constraint, the rapid heating rate at temperatures below the silicate solidus is required to suppress the isotopic fractionation. We have developed a new shock-wave heating model taking into account the radiative transfer of the dust thermal continuum emission and the line emission of gas molecules and calculated the thermal history of chondrules. We have found that optically-thin shock waves for the thermal continuum emission from dust particles can meet the rapid heating constraint, because the dust thermal emission does not keep the dust particles high temperature for a long time in the pre-shock region and dust particles are abruptly heated by the gas drag heating in the post-shock region. We have also derived the upper limit of optical depth of the pre-shock region using the radiative diffusion approximation, above which the rapid heating constraint is not satisfied. It is about 1 - 10.

  9. Flux-Limited Diffusion Approximation Models of Giant Planet Formation by Disk Instability

    E-Print Network [OSTI]

    Boss, Alan P

    2008-01-01T23:59:59.000Z

    Both core accretion and disk instability appear to be required as formation mechanisms in order to explain the entire range of giant planets found in extrasolar planetary systems. Disk instability is based on the formation of clumps in a marginally-gravitationally unstable protoplanetary disk. These clumps can only be expected to contract and survive to become protoplanets if they are able to lose thermal energy through a combination of convection and radiative cooling. Here we present several new three dimensional, radiative hydrodynamics models of self-gravitating protoplanetary disks, where radiative transfer is handled in the flux-limited diffusion approximation. We show that while the flux-limited models lead to higher midplane temperatures than in a diffusion approximation model without the flux-limiter, the difference in temperatures does not appear to be sufficiently high to have any significant effect on the formation of self-gravitating clumps. Self-gravitating clumps form rapidly in the models both...

  10. PHYSICAL NATURE OF SHEAR BANDS FORMATION AND CONSTITUTIVE MODELLING FOR PLASTIC INSTABILITY

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    697 PHYSICAL NATURE OF SHEAR BANDS FORMATION AND CONSTITUTIVE MODELLING FOR PLASTIC INSTABILITYtokrzyska 21,00-049 Warsaw,Poland Revue Phys. Appl. 23 (1988) 697 AVRIL 1988, Studies of plastic deformation dependent hardening property can be pivotal in the modelling for plastic deform- ation instability

  11. Developed C++ Action and Data classes Model in text format

    E-Print Network [OSTI]

    Liske, Jochen

    (transition actions or entry/exit actions). ARCHITECTURE MODEL TRANSFORMATIONS MAINTENANCE An application entry/ ACTION1 STEP2 entry/ ACTION2 STEPn entry/ ACTIONn EVENT1 SKIP1EVENT2 EVENTn SKIP2 EVENTn+1SKIPn IDLE ITERATION entry/ ACTION1 CONDITION entry/ ACTION2 EVENT1 EVENT2COMPLETED NEXT IDLE STEP1 STEP2

  12. Formation of algae growth constitutive relations for improved algae modeling.

    SciTech Connect (OSTI)

    Gharagozloo, Patricia E.; Drewry, Jessica L.

    2013-01-01T23:59:59.000Z

    This SAND report summarizes research conducted as a part of a two year Laboratory Directed Research and Development (LDRD) project to improve our abilities to model algal cultivation. Algae-based biofuels have generated much excitement due to their potentially large oil yield from relatively small land use and without interfering with the food or water supply. Algae mitigate atmospheric CO2 through metabolism. Efficient production of algal biofuels could reduce dependence on foreign oil by providing a domestic renewable energy source. Important factors controlling algal productivity include temperature, nutrient concentrations, salinity, pH, and the light-to-biomass conversion rate. Computational models allow for inexpensive predictions of algae growth kinetics in these non-ideal conditions for various bioreactor sizes and geometries without the need for multiple expensive measurement setups. However, these models need to be calibrated for each algal strain. In this work, we conduct a parametric study of key marine algae strains and apply the findings to a computational model.

  13. Modeling the formation and size distribution of fly ash

    SciTech Connect (OSTI)

    Dahlin, R.S.

    1985-01-01T23:59:59.000Z

    A set of mathematical models has been developed to predict the size distribution of fly ash particles formed in pulverized coal combustion. The large particle mode of the size distribution, typically centered about 10 to 20 ..mu..m, is predicted by a simple breakup model that is based on the complete coalescence of molten mineral inclusions within fragments of the devolatilized coal char. The ultrafine particle mode, that is typically centered about 0.1 to 0.2 ..mu..m, is modeled in terms of ash volatilization, nucleation, and coagulation. Silica and alumina are reduced to volatile suboxides through reactions at the char surface. The volatile suboxides are transported from the char surface where they are oxidized back to the stable oxides in the bulk gas, and then nucleated in accordance with homogeneous nucleation theory. The ultrafine nuclei coagulate in accordance with Brownian coagulation theory. The predicted particle size spectra have been compared to measured size distributions from a pilot-scale combustor and a full-scale utility boiler. Considering the disproportionate loss of coarse particles in the pilot-scale unit, the agreement between the predicted and measured size distributions was considered reasonably good. Both the predicted ultrafine and large particle modes agreed reasonably well with the measured particle size distribution for the full scale boiler. The validated computer models were used to study the effect of changes in the coal ash content, coal particle size, and the combustion flame temperature.

  14. Diosmacycloalkanes as models for the formation of hydrocarbons from surface methylenes

    SciTech Connect (OSTI)

    Norton, J.R.

    1993-05-01T23:59:59.000Z

    The report is divided into: vibrational models for surface ethylidenes (on catalyst surfaces); alpha vs beta hydrogen elimination in formation of propene from an osmacyclobutane; mechanism of formation and fragmentation of diosmacyclobutanes; reaction of dienes and allenes with diosmacyclobutanes; structure of Os(CO)[sub 4](C[sub 2]H[sub 4]), an osmacyclopropane; and reaction of [mu]-oxobis [(trifluoromethanesulfanato) (phenyl)iodine(III)] with Group 14 propargyl derivatives and a propargyl ether. 16 refs, figs.

  15. Atomistic modeling of Ru nanocluster formation on graphene/Ru(0001): Thermodynamically versus kinetically directed-assembly

    E-Print Network [OSTI]

    Ulm, Universität

    Atomistic modeling of Ru nanocluster formation on graphene/Ru(0001): Thermodynamically versus nanocluster formation on a monolayer of graphene supported on Ru(0001) at 309 K. Nanocluster density, mean

  16. Flux-Limited Diffusion Approximation Models of Giant Planet Formation by Disk Instability

    E-Print Network [OSTI]

    Alan P. Boss

    2008-01-28T23:59:59.000Z

    Both core accretion and disk instability appear to be required as formation mechanisms in order to explain the entire range of giant planets found in extrasolar planetary systems. Disk instability is based on the formation of clumps in a marginally-gravitationally unstable protoplanetary disk. These clumps can only be expected to contract and survive to become protoplanets if they are able to lose thermal energy through a combination of convection and radiative cooling. Here we present several new three dimensional, radiative hydrodynamics models of self-gravitating protoplanetary disks, where radiative transfer is handled in the flux-limited diffusion approximation. We show that while the flux-limited models lead to higher midplane temperatures than in a diffusion approximation model without the flux-limiter, the difference in temperatures does not appear to be sufficiently high to have any significant effect on the formation of self-gravitating clumps. Self-gravitating clumps form rapidly in the models both with and without the flux-limiter. These models suggest that the reason for the different outcomes of numerical models of disk instability by different groups cannot be attributed solely to the handling of radiative transfer, but rather appears to be caused by a range of numerical effects and assumptions. Given the observational imperative to have disk instability form at least some extrasolar planets, these models imply that disk instability remains as a viable giant planet formation mechanism.

  17. New Result Formats on OpenEI | OpenEI Community

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup |JilinLuOpen EnergyNelsoniX LtdNew Energy OpportunitiesNew Result

  18. A THREE-PHASE CHEMICAL MODEL OF HOT CORES: THE FORMATION OF GLYCINE

    SciTech Connect (OSTI)

    Garrod, Robin T., E-mail: rgarrod@astro.cornell.edu [Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14853-6801 (United States)

    2013-03-01T23:59:59.000Z

    A new chemical model is presented that simulates fully coupled gas-phase, grain-surface, and bulk-ice chemistry in hot cores. Glycine (NH{sub 2}CH{sub 2}COOH), the simplest amino acid, and related molecules such as glycinal, propionic acid, and propanal, are included in the chemical network. Glycine is found to form in moderate abundance within and upon dust-grain ices via three radical-addition mechanisms, with no single mechanism strongly dominant. Glycine production in the ice occurs over temperatures {approx}40-120 K. Peak gas-phase glycine fractional abundances lie in the range 8 Multiplication-Sign 10{sup -11}-8 Multiplication-Sign 10{sup -9}, occurring at {approx}200 K, the evaporation temperature of glycine. A gas-phase mechanism for glycine production is tested and found insignificant, even under optimal conditions. A new spectroscopic radiative-transfer model is used, allowing the translation and comparison of the chemical-model results with observations of specific sources. Comparison with the nearby hot-core source NGC 6334 IRS1 shows excellent agreement with integrated line intensities of observed species, including methyl formate. The results for glycine are consistent with the current lack of a detection of this molecule toward other sources; the high evaporation temperature of glycine renders the emission region extremely compact. Glycine detection with ALMA is predicted to be highly plausible, for bright, nearby sources with narrow emission lines. Photodissociation of water and subsequent hydrogen abstraction from organic molecules by OH, and NH{sub 2}, are crucial to the buildup of complex organic species in the ice. The inclusion of alternative branches within the network of radical-addition reactions appears important to the abundances of hot-core molecules; less favorable branching ratios may remedy the anomalously high abundance of glycolaldehyde predicted by this and previous models.

  19. Modeling the star formation in galaxies using the Chemo - dynamical SPH code

    E-Print Network [OSTI]

    Peter Berczik

    2000-07-19T23:59:59.000Z

    A new Chemo - Dynamical Smoothed Particle Hydrodynamic (CD - SPH) code is presented. The disk galaxy is described as a multi - fragmented gas and star system, embedded in a cold dark matter halo. The star formation (SF) process, SNII, SNIa and PN events as well as chemical enrichment of gas have been considered within the framework of the standard SPH model. Using this model we describe the dynamical and chemical evolution of triaxial disk - like galaxies. It is found that such approach provides a realistic description of the process of formation, chemical and dynamical evolution of disk galaxies over a cosmological timescale.

  20. A feedback compression star formation model and the black hole - bulge relations

    E-Print Network [OSTI]

    Bing-Xiao Xu; Xue-Bing Wu

    2007-06-05T23:59:59.000Z

    We present a "feedback compression" model to describe the galactic spheroid formation and its relation with the central nuclear activity. We suggest that the star formation itself can serve as the "positive feedback" in some extremely dense region to trigger the starburst. The star formation rate as well as the related stellar feedback-induced turbulence will be maximized under the regulation of the background dark halo's gravity. There is also stellar feedback acting inward to confine and obscure the central black hole (BH) till the BH grows sufficiently large to satisfy a balance condition between the accretion disk wind and the inward stellar feedback. The extremely vigorous star formation activity, the BH - bulge relations, the maximum velocity dispersion as well as the maximum BH mass are investigated based on such scenario, and are found to be consistent with observations.

  1. Running spectral index and formation of primordial black hole in single field inflation models

    SciTech Connect (OSTI)

    Drees, Manuel; Erfani, Encieh, E-mail: drees@th.physik.uni-bonn.de, E-mail: erfani@th.physik.uni-bonn.de [Physikalisches Institut and Bethe Center for Theoretical Physics, Universität Bonn, Nussallee 12, 53115 Bonn (Germany)

    2012-01-01T23:59:59.000Z

    A broad range of single field models of inflation are analyzed in light of all relevant recent cosmological data, checking whether they can lead to the formation of long-lived Primordial Black Holes (PBHs). To that end we calculate the spectral index of the power spectrum of primordial perturbations as well as its first and second derivatives. PBH formation is possible only if the spectral index increases significantly at small scales, i.e. large wave number k. Since current data indicate that the first derivative ?{sub S} of the spectral index n{sub S}(k{sub 0}) is negative at the pivot scale k{sub 0}, PBH formation is only possible in the presence of a sizable and positive second derivative (''running of the running'') ?{sub S}. Among the three small-field and five large-field models we analyze, only one small-field model, the ''running mass'' model, allows PBH formation, for a narrow range of parameters. We also note that none of the models we analyze can accord for a large and negative value of ?{sub S}, which is weakly preferred by current data.

  2. Modeling results for the ITER cryogenic fore pump

    SciTech Connect (OSTI)

    Zhang, D. S.; Miller, F. K.; Pfotenhauer, J. M. [University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2014-01-29T23:59:59.000Z

    The cryogenic fore pump (CFP) is designed for ITER to collect and compress hydrogen isotopes during the regeneration process of torus cryopumps. Different from common cryopumps, the ITER-CFP works in the viscous flow regime. As a result, both adsorption boundary conditions and transport phenomena contribute unique features to the pump performance. In this report, the physical mechanisms of cryopumping are studied, especially the diffusion-adsorption process and these are coupled with standard equations of species, momentum and energy balance, as well as the equation of state. Numerical models are developed, which include highly coupled non-linear conservation equations of species, momentum and energy and equation of state. Thermal and kinetic properties are treated as functions of temperature, pressure, and composition. To solve such a set of equations, a novel numerical technique, identified as the Group-Member numerical technique is proposed. It is presented here a 1D numerical model. The results include comparison with the experimental data of pure hydrogen flow and a prediction for hydrogen flow with trace helium. An advanced 2D model and detailed explanation of the Group-Member technique are to be presented in following papers.

  3. Comparison of Blade-Strike Modeling Results with Empirical Data

    SciTech Connect (OSTI)

    Carlson, Thomas J.; Ploskey, Gene R.

    2004-05-06T23:59:59.000Z

    This study is the initial stage of further investigation into the dynamics of injury to fish during passage through a turbine runner. As part of the study, Pacific Northwest National Laboratory (PNNL) estimated the probability of blade strike, and associated injury, as a function of fish length and turbine operating geometry at two adjacent turbines in Powerhouse 1 of Bonneville Dam. Units 5 and 6 had identical intakes, stay vanes, wicket gates, and draft tubes, but Unit 6 had a new runner and curved discharge ring to minimize gaps between the runner hub and blades and between the blade tips and discharge ring. We used a mathematical model to predict blade strike associated with two Kaplan turbines and compared results with empirical data from biological tests conducted in 1999 and 2000. Blade-strike models take into consideration the geometry of the turbine blades and discharges as well as fish length, orientation, and distribution along the runner.

  4. Cloud Formation in the Plumes of Solar Chimney Power Generation Facilities: A Modeling Study

    E-Print Network [OSTI]

    Nenes, Athanasios

    for a proposed solar chimney facility in southwestern Australia. A range of temperatures and updraft velocities technology for converting solar energy into electricity that has shown promise in recent years is the so1 Cloud Formation in the Plumes of Solar Chimney Power Generation Facilities: A Modeling Study

  5. A quantitative model of trading and price formation in financial markets Marcus G. Daniels,1

    E-Print Network [OSTI]

    A quantitative model of trading and price formation in financial markets Marcus G. Daniels,1 J is the standard measure of financial risk, and the spread and price impact functions, which are the main determinants of transaction cost. Guided by dimensional analysis, simulation, and mean field theory, we find

  6. Evaluating variable switching and flash methods in modeling carbon sequestration in deep geologic formations

    E-Print Network [OSTI]

    Mills, Richard

    Evaluating variable switching and flash methods in modeling carbon sequestration in deep geologic performance computing to assess the risks involved in carbon sequestration in deep geologic formations-thermal- chemical processes in variably saturated, non-isothermal porous media is applied to sequestration

  7. A Direct Reputation Model for VO Formation Arturo Avila-Rosas1

    E-Print Network [OSTI]

    Luck, Michael

    Mexicano del Petr´oleo, Eje Central 152, M´exico DF, CP 07730, M´exico aavilar@imp.mx 2 SchoolA Direct Reputation Model for VO Formation Arturo Avila-Rosas1 and Michael Luck2 1 Instituto

  8. Biogeochemical Processes in a Clay Formation In-situ Experiment: Part B Results from overcoring and evidence of strong buffering by the

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    2 Biogeochemical Processes in a Clay Formation In-situ Experiment: Part B ­ Results from overcoring in the Opalinus Clay formation was carried out at the Mont Terri underground rock laboratory (Jura Mountains/precipitation reactions. After five years, the 4.5 m long vertical test interval was overcored and Opalinus clay samples

  9. H2A Delivery Models and Results | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet), GeothermalGrid Integration0-1 MarchH-TankModels and Results H2A

  10. Dark Stars: Improved Models and First Pulsation Results

    E-Print Network [OSTI]

    Tanja Rindler-Daller; Michael H. Montgomery; Katherine Freese; Donald E. Winget; Bill Paxton

    2015-01-12T23:59:59.000Z

    We use the stellar evolution code MESA to study dark stars. Dark stars (DSs), which are powered by dark matter (DM) self-annihilation rather than by nuclear fusion, may be the first stars to form in the Universe. We compute stellar models for accreting DSs with masses up to 10^6 M_{sun}. The heating due to DM annihilation is self-consistently included, assuming extended adiabatic contraction of DM within the minihalos in which DSs form. We find remarkably good overall agreement with previous models, which assumed polytropic interiors. There are some differences in the details, with positive implications for observability. We found that, in the mass range of 10^4 -10^5 M_{sun}, our DSs are hotter by a factor of 1.5 than those in Freese et al.(2010), are smaller in radius by a factor of 0.6, denser by a factor of 3 - 4, and more luminous by a factor of 2. Our models also confirm previous results, according to which supermassive DSs are very well approximated by (n=3)-polytropes. We also perform a first study of dark star pulsations. Our DS models have pulsation modes with timescales ranging from less than a day to more than two years in their rest frames, at z ~ 15, depending on DM particle mass and overtone number. Such pulsations may someday be used to identify bright, cool objects uniquely as DSs; if properly calibrated, they might, in principle, also supply novel standard candles for cosmological studies.

  11. Model for isopaching Jurassic-age Norphlet Formation in Mobile Bay, Alabama area

    SciTech Connect (OSTI)

    Torres, L.F.

    1989-03-01T23:59:59.000Z

    Deep gas was discovered in the Norphlet Sandstone of Mobile Bay Alabama in 1979. Sixteen wells, of which Exxon Company, U.S.A. has had an interest in eight, have tested gas from depths greater than 20,000 ft and at an average rate of 19 million ft/sub 3/ of gas per day. The dominant structural features in Mobile Bay are large east-west-trending salt-supported anticlines associated with salt pull-apart listric normal faulting. Throws on these faults measure up to 1000 ft. Individual structures have dimensions as large as 15 mi in an east-west strike direction and 8 mi in a north-south dip direction. The Jurassic age (Callovian) Norphlet of Mobile Bay is characterized by eolian dune sand deposits up to 700 ft thick. An important factor affecting future development drilling is the accurate prediction of reservoir thickness. This presentation shows that an integrated study of seismic and well data has facilitated the development of a geological model for isopaching the Norphlet Formation. The isopach exhibits a strong north-northwest-south-southeast orientation of parallel thicks and thins. These trends are believed to be the result of original eolian deposition of complex linear dunes in the Norphlet Sandstone. The major east-west structural grain of faults and anticlines overprints this preserved depositional trend.

  12. MODELING RESULTS FROM CESIUM ION EXCHANGE PROCESSING WITH SPHERICAL RESINS

    SciTech Connect (OSTI)

    Nash, C.; Hang, T.; Aleman, S.

    2011-01-03T23:59:59.000Z

    Ion exchange modeling was conducted at the Savannah River National Laboratory to compare the performance of two organic resins in support of Small Column Ion Exchange (SCIX). In-tank ion exchange (IX) columns are being considered for cesium removal at Hanford and the Savannah River Site (SRS). The spherical forms of resorcinol formaldehyde ion exchange resin (sRF) as well as a hypothetical spherical SuperLig{reg_sign} 644 (SL644) are evaluated for decontamination of dissolved saltcake wastes (supernates). Both SuperLig{reg_sign} and resorcinol formaldehyde resin beds can exhibit hydraulic problems in their granular (nonspherical) forms. SRS waste is generally lower in potassium and organic components than Hanford waste. Using VERSE-LC Version 7.8 along with the cesium Freundlich/Langmuir isotherms to simulate the waste decontamination in ion exchange columns, spherical SL644 was found to reduce column cycling by 50% for high-potassium supernates, but sRF performed equally well for the lowest-potassium feeds. Reduced cycling results in reduction of nitric acid (resin elution) and sodium addition (resin regeneration), therefore, significantly reducing life-cycle operational costs. These findings motivate the development of a spherical form of SL644. This work demonstrates the versatility of the ion exchange modeling to study the effects of resin characteristics on processing cycles, rates, and cold chemical consumption. The value of a resin with increased selectivity for cesium over potassium can be assessed for further development.

  13. GREET 1.5 - transportation fuel-cycle model - Vol. 1 : methodology, development, use, and results.

    SciTech Connect (OSTI)

    Wang, M. Q.

    1999-10-06T23:59:59.000Z

    This report documents the development and use of the most recent version (Version 1.5) of the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The model, developed in a spreadsheet format, estimates the full fuel-cycle emissions and energy associated with various transportation fuels and advanced vehicle technologies for light-duty vehicles. The model calculates fuel-cycle emissions of five criteria pollutants (volatile organic compounds, carbon monoxide, nitrogen oxides, particulate matter with diameters of 10 micrometers or less, and sulfur oxides) and three greenhouse gases (carbon dioxide, methane, and nitrous oxide). The model also calculates total energy consumption, fossil fuel consumption, and petroleum consumption when various transportation fuels are used. The GREET model includes the following cycles: petroleum to conventional gasoline, reformulated gasoline, conventional diesel, reformulated diesel, liquefied petroleum gas, and electricity via residual oil; natural gas to compressed natural gas, liquefied natural gas, liquefied petroleum gas, methanol, Fischer-Tropsch diesel, dimethyl ether, hydrogen, and electricity; coal to electricity; uranium to electricity; renewable energy (hydropower, solar energy, and wind) to electricity; corn, woody biomass, and herbaceous biomass to ethanol; soybeans to biodiesel; flared gas to methanol, dimethyl ether, and Fischer-Tropsch diesel; and landfill gases to methanol. This report also presents the results of the analysis of fuel-cycle energy use and emissions associated with alternative transportation fuels and advanced vehicle technologies to be applied to passenger cars and light-duty trucks.

  14. Results of EPRI/ANL DCH investigations and model development

    SciTech Connect (OSTI)

    Spencer, B.W.; Sienicki, J.J.; Sehgal, B.R.; Merilo, M.

    1988-01-01T23:59:59.000Z

    The results of a series of five experiments are described addressing the severity and mitigation of direct containment heating. The tests were performed in a 1:30 linear scale mockup of the Zion PWR containment system using a reactor-material corium melt consisting of 60% UO/sub 2/, 16% ZrO/sub 2/, 24% SSt at nominally 2800C initial temperature. A ''worst-case'' type test involving unimpeded corium dispersal through an air atmosphere in a closed vessel produced an atmosphere heatup of 323K, equivalent to a DCH efficiency of 62%. With the addition of structural features which impeded the corium dispersal, representative of dispersal pathway features at Zion, the DCH efficiency was reduced to 1--5%. (This important result is scale dependent and requires larger scale tests such as the SURTSEY program at SNL plus mechanistic modeling for application to the reactor system.) With the addition of water in the cavity region, there was no measurable heatup of the atmosphere. This was attributable to the vigorous codispersal of water with corium which prevented the temperature of the atmosphere from significantly exceeding T/sub sat/. In this case the DCH load was replaced by the more benign ''steam spike'' from corium quench. Significant oxidation of the corium constituents occurred in the tests, adding chemical energy to the system and producing hydrogen. Overall, the results suggest that with consideration of realistic, plant specific, mitigating features, DCH may be no worse and possibly far less severe than the previously examined steam spike. Implications for accident management are addressed. 17 refs., 7 figs., 4 tabs.

  15. Dust in brown dwarfs and extra-solar planets IV. Assessing TiO2 and SiO nucleation for cloud formation modeling

    E-Print Network [OSTI]

    Lee, G; Giles, H; Bromley, S T

    2014-01-01T23:59:59.000Z

    Clouds form in atmospheres of brown dwarfs and planets. The cloud particle formation processes are similar to the dust formation process studied in circumstellar shells of AGB stars and in Supernovae. Cloud formation modelling in substellar objects requires gravitational settling and element replenishment in addition to element depletion. All processes depend on the local conditions, and a simultaneous treatment is required. We apply new material data in order to assess our cloud formation model results regarding the treatment of the formation of condensation seeds. We re-address the question of the primary nucleation species in view of new (TiO2)_N-cluster data and new SiO vapour pressure data. We apply the density functional theory using the computational chemistry package Gaussian 09 to derive updated thermodynamical data for (TiO2)_N-clusters as input for our TiO2 seed formation model. We test different nucleation treatments and their effect on the overall cloud structure by solving a system of dust momen...

  16. Exact results for ionization of model atomic systems

    SciTech Connect (OSTI)

    Costin, O.; Tanveer, S. [Department of Mathematics, Ohio State University, Columbus, Ohio 43210 (United States); Lebowitz, J. L. [Department of Mathematics, Rutgers University, Piscataway, New Jersey 08854 (United States); Department of Physics, Rutgers University, Piscataway, New Jersey 08854 (United States); Stucchio, C. [Courant Institute, New York University, New York, New York 10276 (United States)

    2010-01-15T23:59:59.000Z

    We review recent rigorous results concerning the ionization of model quantum systems by time-periodic external fields. The systems we consider consist of a single particle (electron) with a reference Hamiltonian H{sub 0}=-{delta}+V{sub 0}(x) (x is an element of R{sup d}) having both bound and continuum states. Starting from an initially localized state {psi}{sub 0}(x) is an element of L{sup 2}(R{sup d}), the system is subjected for t{>=}0 to an arbitrary strength time-periodic potential V{sub 1}(x,t)=V{sub 1}(x,t+2{pi}/{omega}). We prove that for a large class of V{sub 0}(x) and V{sub 1}(x,t), the wave function {psi}(x,t) will delocalize as t{yields}{infinity}, i.e., the system will ionize. The only exceptions are cases where there are time-periodic bound states of the Floquet operator associated with H{sub 0}+V{sub 1}. These do occur (albeit rarely) when V{sub 1} is not small. For spatially rapidly decaying V{sub 0} and V{sub 1}, {psi}(x,t) is generally given, for very long times, by a power series in t{sup -1/2} which we prove in some cases to be Borel summable. For the Coulomb potential V{sub 0}(x)=-b|x|{sup -1} in R{sup 3}, we prove ionization for V{sub 1}(x,t)=V{sub 1}(|x|)sin({omega}t-{theta}), V{sub 1}(|x|)=0 for |x|>R and V{sub 1}(x)>0 for |x|{<=}R. For this model, if {psi}{sub 0} is compactly supported both in x and in angular momentum, L, we obtain that {psi}(x,t){approx}O(t{sup -5/6}) as t{yields}{infinity}.

  17. Modeling of Nonuniform Degradation in Large-Format Li-ion Batteries (Poster)

    SciTech Connect (OSTI)

    Smith, K.; Kim, G. H.; Pesaran, A.

    2009-06-01T23:59:59.000Z

    Shows results of an empirical model capturing effects of both storage and cycling and developed the lithium ion nickel cobalt aluminum advanced battery chemistry.

  18. Dust-regulated galaxy formation and evolution:A new chemodynamical model with live dust particles

    E-Print Network [OSTI]

    Bekki, Kenji

    2015-01-01T23:59:59.000Z

    Interstellar dust plays decisive roles in the conversion of neutral to molecular hydrogen (H_2), the thermodynamical evolution of interstellar medium (ISM), and the modification of spectral energy distributions (SEDs) of galaxies. These important roles of dust have not been self-consistently included in previous numerical simulations of galaxy formation and evolution. We have therefore developed a new model by which one can investigate whether and how galaxy formation and evolution can be influenced by dust-related physical processes such as photo-electric heating, H_2 formation on dust, and stellar radiation pressure on dust in detail. A novel point of the model is that different dust species in a galaxy are represented by `live dust' particles (i.e., not test particles). Therefore, dust particles in a galaxy not only interact gravitationally with all four components of the galaxy (i.e., dark matter, stars, gas, and dust) but also are grown and destroyed through physical processes of ISM. First we describe a...

  19. Random sequential adsorption model of damage and crack accumulation: Exact one-dimensional results

    E-Print Network [OSTI]

    O. Gromenko; V. Privman; M. L. Glasser

    2008-04-29T23:59:59.000Z

    The random sequential adsorption (RSA) model is modified to describe damage and crack accumulation. The exclusion for object deposition (for damaged region formation) is not for the whole object, as in the standard RSA, but only for the initial point (or higher-dimensional defect) from which the damaged region or crack initiates. The one-dimensional variant of the model is solved exactly.

  20. Towards accurate kinetic modeling of prompt NO formation in hydrocarbon flames via the NCN pathway

    SciTech Connect (OSTI)

    Sutton, Jeffrey A. [Department of Mechanical Engineering, The Ohio State University, Columbus, OH 43210 (United States); Fleming, James W. [Navy Technology Center for Safety and Survivability, Chemistry Division, Code 6185, Naval Research Laboratory, Washington, DC 20375-5342 (United States)

    2008-08-15T23:59:59.000Z

    A basic kinetic mechanism that can predict the appropriate prompt-NO precursor NCN, as shown by experiment, with relative accuracy while still producing postflame NO results that can be calculated as accurately as or more accurately than through the former HCN pathway is presented for the first time. The basic NCN submechanism should be a starting point for future NCN kinetic and prompt NO formation refinement.

  1. Results from modeling and simulation of chemical downstream etch systems

    SciTech Connect (OSTI)

    Meeks, E.; Vosen, S.R.; Shon, J.W.; Larson, R.S.; Fox, C.A.; Buchenauer

    1996-05-01T23:59:59.000Z

    This report summarizes modeling work performed at Sandia in support of Chemical Downstream Etch (CDE) benchmark and tool development programs under a Cooperative Research and Development Agreement (CRADA) with SEMATECH. The Chemical Downstream Etch (CDE) Modeling Project supports SEMATECH Joint Development Projects (JDPs) with Matrix Integrated Systems, Applied Materials, and Astex Corporation in the development of new CDE reactors for wafer cleaning and stripping processes. These dry-etch reactors replace wet-etch steps in microelectronics fabrication, enabling compatibility with other process steps and reducing the use of hazardous chemicals. Models were developed at Sandia to simulate the gas flow, chemistry and transport in CDE reactors. These models address the essential components of the CDE system: a microwave source, a transport tube, a showerhead/gas inlet, and a downstream etch chamber. The models have been used in tandem to determine the evolution of reactive species throughout the system, and to make recommendations for process and tool optimization. A significant part of this task has been in the assembly of a reasonable set of chemical rate constants and species data necessary for successful use of the models. Often the kinetic parameters were uncertain or unknown. For this reason, a significant effort was placed on model validation to obtain industry confidence in the model predictions. Data for model validation were obtained from the Sandia Molecular Beam Mass Spectrometry (MBMS) experiments, from the literature, from the CDE Benchmark Project (also part of the Sandia/SEMATECH CRADA), and from the JDP partners. The validated models were used to evaluate process behavior as a function of microwave-source operating parameters, transport-tube geometry, system pressure, and downstream chamber geometry. In addition, quantitative correlations were developed between CDE tool performance and operation set points.

  2. Summary Results for Brine Migration Modeling Performed by LANL...

    Energy Savers [EERE]

    in a High Level Waste Repository in Salt Establishing the Technical Basis for Disposal of Heat-generating Waste in Salt Model Development and Analysis of the Fate and Transport of...

  3. The p-Process in the Carbon Deflagration Model for Type Ia Supernovae and Chronology of the Solar System Formation

    SciTech Connect (OSTI)

    Kusakabe, Motohiko [Department of Astronomy, School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Iwamoto, Nobuyuki [Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Nomoto, Ken'ichi [Department of Astronomy, School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2006-07-12T23:59:59.000Z

    We study nucleosynthesis of p-nuclei in the carbon deflagration model for Type Ia supernovae (SNe Ia) by assuming that seed nuclei are produced by the s-process in accreting layers on a carbon-oxygen white dwarf during mass accretion from a binary companion. We find that about 50 % of the p-nuclides are synthesized in proportion to the solar abundance and that p-isotopes of Mo and Ru which are significantly underproduced in Type II supernovae (SNe II) are produced up to a level close to other p-nuclei. Comparing the yields of iron and p-nuclei in SNe Ia we find that SNe Ia can contribute to the galactic evolution of the p-nuclei. Next, we consider nucleochronology of the solar system formation by using four radioactive nuclides and apply the result of the p-process nucleosynthesis to simple galactic chemical evolution models. We find that when assumed three phases of interstellar medium are mixed by the interdiffusion with the timescale of about 40 Myr 53Mn/55Mn value in the early solar system is consistent with a meteoritic value. In addition, we put constraints to a scenario that SNe Ia induce the core collapse of the molecular cloud, which leads to the formation of the solar system.

  4. Top-Down Modeling; Practical, Fast-Track, Reservoir Modeling for Shale Formations AAPG/SEG/SPE/SPWLA Hedberg Conference, Austin, TX December 2010

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    1 Top-Down Modeling; Practical, Fast-Track, Reservoir Modeling for Shale Formations AAPG OF SHALE RESOURCE PLAYS" DECEMBER 5-10, 2010 ­ AUSTIN, TEXAS Top-Down Modeling; Practical, Fast Track SUMMARY This article reviews a new reservoir simulation and modeling technology called Top

  5. Application of tidal mudflat model to Sunniland Formation (Lower Cretaceous) of south Florida

    SciTech Connect (OSTI)

    Mitchell-Tapping, H.J.

    1987-09-01T23:59:59.000Z

    For many years, the Lower Cretaceous Sunniland oil-producing fields have been interpreted as reef deposits. Petrologic evidence from cores from field and wildcat wells strongly indicates on the basis of faunal composition and character, that the fields are producing from moundlike shoals. These shoals are considered to have been deposited in a mudflat environment similar to that of present-day Florida Bay. This present-day Florida Bay analog is used to determine the various environmental subzones and controls on the deposition of the Sunniland Formation. This concept of using a model together with a modern analog can be a powerful tool in the exploration of stratigraphic traps. A petrologic and petrophysical study of the Sunniland Formation in the wells that have been drilled in the Florida Bay and Keys areas was made to extend the model and its application throughout the South Florida basin. The evaluation of these wells has produced new insights into the tectonics of this basin and its relationship to the Bahamas and Caribbean areas.

  6. Theoretical and Experimental Modelling of Bubble Formation with Connected Capillaries in Liquid Composite Moulding Processes

    E-Print Network [OSTI]

    Wielhorski, Yanneck; Bizet, Laurent; Bréard, Joël

    2012-01-01T23:59:59.000Z

    The void prediction in LCM processes sparks off interest within the composite material industry because it is a significant issue to keep the expected mechanical properties. The liquid properties, the preform geometry and the flow conditions impact the quantity of void entrapped inside the final product. The complex geometry of the reinforcement due to the arrangement of the bundles and the fibres is a key point to understand and quantify this phenomenon. This paper deals with both simple model networks which can occur inside a fabric representing connected capillaries, so-called "Pore Doublet Model (PDM)". A first is considering two capillaries converging on a node (T-junction) and a second is representing two capillaries interconnected with a supplying principle. These configurations can affect locally the evolution of flow fronts. First, experiments of bubble formed in a T-junction device have been performed and studied. Then a theoretical approach was proposed to forecast microvoid and macrovoid formation...

  7. Electromagnetic scattering from grassland Part II: Measurement and modeling results

    E-Print Network [OSTI]

    Stiles, James Marion; Ulaby, F. T.; Sarabandi, K.

    2000-01-01T23:59:59.000Z

    -InvestigatoronmanyprojectssponsoredbyNASA,JPL,ARO,ONR,ARL, and GM all related in one way or the other to microwave and millimeter wave radar remote sensing. He has published many book chapters and more than 80 papers in refereed journals on electromagnetic scattering, random media modeling, microwave measurement...LecturerAwardfromtheGerman Federal Ministry for Education, Science, and Technology. FawwazT.Ulaby(M’68–SM’74–F’80)receivedthe B.S.degreeinphysicsfromtheAmericanUniversity of Beirut, Lebanon, in 1964, and the M.S.E.E. and Ph.D.degreesinelectricalengineeringfromtheUni- versity...

  8. MODELING THE GRB HOST GALAXY MASS DISTRIBUTION: ARE GRBs UNBIASED TRACERS OF STAR FORMATION?

    E-Print Network [OSTI]

    Kocevski, Daniel

    We model the mass distribution of long gamma-ray burst (GRB) host galaxies given recent results suggesting that GRBs occur in low-metallicity environments. By utilizing measurements of the redshift evolution of the ...

  9. HOT X-RAY CORONAE AROUND MASSIVE SPIRAL GALAXIES: A UNIQUE PROBE OF STRUCTURE FORMATION MODELS

    SciTech Connect (OSTI)

    Bogdan, Akos; Forman, William R.; Vogelsberger, Mark; Sijacki, Debora; Mazzotta, Pasquale; Kraft, Ralph P.; Jones, Christine; David, Laurence P. [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bourdin, Herve [Dipartimento di Fisica, Universita degli Studi di Roma 'Tor Vergata', via della Ricerca Scientifica 1, I-00133 Roma (Italy); Gilfanov, Marat; Churazov, Eugene, E-mail: abogdan@cfa.harvard.edu [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-str. 1, D-85748 Garching (Germany)

    2013-08-01T23:59:59.000Z

    Luminous X-ray gas coronae in the dark matter halos of massive spiral galaxies are a fundamental prediction of structure formation models, yet only a few such coronae have been detected so far. In this paper, we study the hot X-ray coronae beyond the optical disks of two 'normal' massive spirals, NGC 1961 and NGC 6753. Based on XMM-Newton X-ray observations, hot gaseous emission is detected to {approx}60 kpc-well beyond their optical radii. The hot gas has a best-fit temperature of kT {approx} 0.6 keV and an abundance of {approx}0.1 Solar, and exhibits a fairly uniform distribution, suggesting that the quasi-static gas resides in hydrostatic equilibrium in the potential well of the galaxies. The bolometric luminosity of the gas in the (0.05-0.15)r{sub 200} region (r{sub 200} is the virial radius) is {approx}6 Multiplication-Sign 10{sup 40} erg s{sup -1} for both galaxies. The baryon mass fractions of NGC 1961 and NGC 6753 are f{sub b,NGC1961} {approx} 0.11 and f{sub b,NGC6753} {approx} 0.09, which values fall short of the cosmic baryon fraction. The hot coronae around NGC 1961 and NGC 6753 offer an excellent basis to probe structure formation simulations. To this end, the observations are confronted with the moving mesh code AREPO and the smoothed particle hydrodynamics code GADGET. Although neither model gives a perfect description, the observed luminosities, gas masses, and abundances favor the AREPO code. Moreover, the shape and the normalization of the observed density profiles are better reproduced by AREPO within {approx}0.5r{sub 200}. However, neither model incorporates efficient feedback from supermassive black holes or supernovae, which could alter the simulated properties of the X-ray coronae. With the further advance of numerical models, the present observations will be essential in constraining the feedback effects in structure formation simulations.

  10. Conceptual model for transport processes in the Culebra Dolomite Member, Rustler Formation

    SciTech Connect (OSTI)

    Holt, R.M. [Holt Hydrogeology, Placitas, NM (United States)] [Holt Hydrogeology, Placitas, NM (United States)

    1997-08-01T23:59:59.000Z

    The Culebra Dolomite Member of the Rustler Formation represents a possible pathway for contaminants from the Waste Isolation Pilot Plant underground repository to the accessible environment. The geologic character of the Culebra is consistent with a double-porosity, multiple-rate model for transport in which the medium is conceptualized as consisting of advective porosity, where solutes are carried by the groundwater flow, and fracture-bounded zones of diffusive porosity, where solutes move through slow advection or diffusion. As the advective travel length or travel time increases, the nature of transport within a double-porosity medium changes. This behavior is important for chemical sorption, because the specific surface area per unit mass of the diffusive porosity is much greater than in the advective porosity. Culebra transport experiments conducted at two different length scales show behavior consistent with a multiple-rate, double-porosity conceptual model for Culebra transport. Tracer tests conducted on intact core samples from the Culebra show no evidence of significant diffusion, suggesting that at the core scale the Culebra can be modeled as a single-porosity medium where only the advective porosity participates in transport. Field tracer tests conducted in the Culebra show strong double-porosity behavior that is best explained using a multiple-rate model.

  11. A Model Incorporating Some of the Mechanical and Biochemical Factors Underlying Clot Formation and Dissolution in Flowing Blood

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Anand, M.; Rajagopal, K.; Rajagopal, K. R.

    2003-01-01T23:59:59.000Z

    Multiple interacting mechanisms control the formation and dissolution of clots to maintain blood in a state of delicate balance. In addition to a myriad of biochemical reactions, rheological factors also play a crucial role in modulating the response of blood to external stimuli. To date, a comprehensive model for clot formation and dissolution, that takes into account the biochemical, medical and rheological factors, has not been put into place, the existing models emphasizing either one or the other of the factors. In this paper, after discussing the various biochemical, physiologic and rheological factors at some length, we develop a modelmore »for clot formation and dissolution that incorporates many of the relevant crucial factors that have a bearing on the problem. The model, though just a first step towards understanding a complex phenomenon, goes further than previous models in integrating the biochemical, physiologic and rheological factors that come into play.« less

  12. Soot formation modelling of n-heptane sprays under diesel engine conditions using the Conditional Moment Closure

    E-Print Network [OSTI]

    Daraio, Chiara

    1 Soot formation modelling of n-heptane sprays under diesel engine conditions using the Conditional-volume vessel under diesel engine conditions under different ambient densities (14.8 and 30 kg/m3 ) and ambient that the conditional moment closure approach is a promising framework for soot modelling under Diesel engine conditions

  13. Numerical modelling of hybrid arc/laser welding: a Level Set approach for weld bead formation and residual stresses

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Numerical modelling of hybrid arc/laser welding: a Level Set approach for weld bead formation.Bellet@mines-paristech.fr ABSTRACT The joining of high thickness steel sheets by means of hybrid Laser/GMAW welding processes of the workpiece borders. Two finite elements models are presented to illustrate: (i) A hybrid arc/laser welding

  14. Modeling of the formation of short-chain acids in propane flames F. Battin-Leclerc , 1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Modeling of the formation of short-chain acids in propane flames F. Battin-Leclerc , 1 , A. Simulations of lean (equivalence ratios from 0.9 to 0.48) laminar premixed flames of propane stabilized in a combustion apparatus which can easily be modeled, a laminar premixed flame of propane at atmospheric pressure

  15. Toward a Deterministic Model of Planetary Formation V. Accumulation Near the Ice Line

    E-Print Network [OSTI]

    Shigeru Ida; D. N. C. Lin

    2008-06-01T23:59:59.000Z

    We address two outstanding issues in the sequential accretion scenario for gas giant planet formation, the retention of dust grains in the presence of gas drag and that of cores despite type I migration. The efficiency of these processes is determined by the disk structure. Theoretical models suggest that planets form in protostellar disk regions with an inactive neutral ``dead zone'' near the mid plane, sandwiched together by partially ionized surface layers where magnetorotational instability is active. Due to a transition in the abundance of dust grains, the active layer's thickness decreases abruptly near the ice line. Over a range of modest accretion rates ($\\sim 10^{-9}-10^{-8} M_\\odot$ yr$^{-1}$), the change in the angular momentum transfer rate leads to local surface density and pressure distribution maxima near the ice line. The azimuthal velocity becomes super-Keplerian and the grains accumulate in this transition zone. This barrier locally retains protoplanetary cores and enhances the heavy element surface density to the critical value needed to initiate efficient gas accretion. It leads to a preferred location and epoch of gas giant formation. We simulate and reproduce the observed frequency and mass-period distribution of gas giants around solar type stars without having to greatly reduce the type I migration strength. The mass function of the short-period planets can be utilized to calibrate the efficiency of type I migration and to extrapolate the fraction of stars with habitable terrestrial planets.

  16. Diosmacycloalkanes as models for the formation of hydrocarbons from surface methylenes. Progress report, November 1, 1992--October 31, 1993

    SciTech Connect (OSTI)

    Norton, J.R.

    1993-05-01T23:59:59.000Z

    The report is divided into: vibrational models for surface ethylidenes (on catalyst surfaces); alpha vs beta hydrogen elimination in formation of propene from an osmacyclobutane; mechanism of formation and fragmentation of diosmacyclobutanes; reaction of dienes and allenes with diosmacyclobutanes; structure of Os(CO){sub 4}(C{sub 2}H{sub 4}), an osmacyclopropane; and reaction of {mu}-oxobis [(trifluoromethanesulfanato) (phenyl)iodine(III)] with Group 14 propargyl derivatives and a propargyl ether. 16 refs, figs.

  17. Formation of gas-phase peroxides in a rural atmosphere: An interpretation of the recent SOS/SERON field results

    SciTech Connect (OSTI)

    Lee, J.H.; Tang, I.N. [Brookhaven National Lab., Upton, NY (United States); Weinstein-Lloyd, J.B. [State Univ. of New York, Old Westbury, NY (United States). Chemistry/Physics Dept.

    1993-09-01T23:59:59.000Z

    Hydrogen perioxide (H{sub 2}O{sub 2}) and certain organic peroxides such as hydroxymethyl-hydroperoxide (HMHP), are gas-phase oxidants present in the atmosphere at ppbv concentration levels. These oxidants play an important role in atmospheric chemistry. In addition, precipitation containing H{sub 2}O{sub 2} is toxic to trees, and it has also been suggested that organic peroxides formed presumably by ozone reactions with biogenic alkenes are responsible for leaf disorders. Recently, we have developed a nonenzymatic method or aqueous-phase H{sub 2}O{sub 2} measurement, using Fenton reagent and fluorescent hydroxy- benzoic acid. The new method, in conjunction with the well-known method of p-hydroxyphenylacetic acid and horseradish peroxidase for total peroxides, and together with an improved gas scrubber to mitigate sampling line problems, has been successfully deployed in recent SOS/SERON field measurements in rural Georgia. For the first time, continuously measured and speciated gas-phase peroxide data have become available, making it possible to examine some aspects of the ozone chemistry leading to the formation of these oxidants. It is observed that daily H{sub 2}O{sub 2} maximum frequently occurs at a different time than does HMHP, and that H{sub 2}O{sub 2} concentration, but not HMHP, tends to correlate with solar fluxes measured at the same location. These findings seem to indicate that the formation mechanisms for H{sub 2}O{sub 2} and organic peroxides are basically different. It is likely that H{sub 2}O{sub 2} is formed from radical-radical recombination, while HMHP is formed by ozone-alkene reactions. Since the gas-phase ozone-alkene reactions are usually too slow to account for the diurnal concentration variations observed for HMHP, heterogeneous processes involving ozone and alkenes are also a possibility.

  18. A continental clastic depositional model for the Permian Unayzah formation, Hawtah field, central Saudi Arabia

    SciTech Connect (OSTI)

    Heine, C.J. (Saudi Aramco, Dhahran (Saudi Arabia))

    1993-09-01T23:59:59.000Z

    The Permian Unayzah Formation lies unconformably on the Silurian Qusaiba Member of the Qalibah Formation. The pre-Unayzah unconformity (PUU) represents a Hercynian tectonic event responsible for uplift and erosion representing 100-150 m.y. worth of missing section along the Hawtah Trend. Overlying the PUU, the Unayzah clastic sequence is comprised of locally sourced sediments from the adjacent paleotopography. Above the thin veneer of locally sourced sediments is a more regionally sourced, confined braided stream sequence, which completely backfills the existing paleotopography. Once the paleotopographic surface had been leveled, the depositional environment changed from a confined braided stream to a broad braided plain. Within this sequence of vertically stacked and laterally migrating braided plain sediments, the bulk of the reservoirs within the Hawtah field are contained. As the transgressive Khuff seas continue to encroach on the Unayzah depositional system, the upper-most sediments of the broad braided plan environment are reworked by transgressive coastal processes. The resulting reworked shoreface and shallow-marine facies are genetically related to the Khuff transgression and lie unconformably on the Unayzah continental clastics.

  19. Modeling of the formation of short-chain acids in propane flames

    E-Print Network [OSTI]

    Battin-Leclerc, Frédérique; Jaffrezo, J L; Legrand, M

    2009-01-01T23:59:59.000Z

    In order to better understand their potential formation in combustion systems, a detailed kinetic mechanism for the formation of short-chain monocarboxylic acids, formic (HCOOH), acetic (CH3COOH), propionic (C2H5COOH) and propenic (C2H3COOH)) acids, has been developed. Simulations of lean (equivalence ratios from 0.9 to 0.48) laminar premixed flames of propane stabilized at atmospheric pressure with nitrogen as diluent have been performed. It was found that amounts up to 25 ppm of acetic acid, 15 ppm of formic acid and 1 ppm of C3 acid can be formed for some positions in the flames. Simulations showed that the more abundant C3 acid formed is propenic acid. A quite acceptable agreement has been obtained with the scarce results from the literature concerning oxygenated compounds, including aldehydes (CH2O, CH3CHO) and acids. A reaction pathways analysis demonstrated that each acid is mainly derived from the aldehyde of similar structure.

  20. Galaxy Formation with Self-Consistently Modeled Stars and Massive Black Holes. I: Feedback-Regulated Star Formation and Black Hole Growth

    SciTech Connect (OSTI)

    Kim, Ji-hoon; Wise, John H.; /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Princeton U., Astrophys. Sci. Dept.; Alvarez, Marcelo A.; /Canadian Inst. Theor. Astrophys.; Abel, Tom; /KIPAC, Menlo Park /Stanford U., Phys. Dept.

    2011-11-04T23:59:59.000Z

    There is mounting evidence for the coevolution of galaxies and their embedded massive black holes (MBHs) in a hierarchical structure formation paradigm. To tackle the nonlinear processes of galaxy-MBH interaction, we describe a self-consistent numerical framework which incorporates both galaxies and MBHs. The high-resolution adaptive mesh refinement (AMR) code Enzo is modified to model the formation and feedback of molecular clouds at their characteristic scale of 15.2 pc and the accretion of gas onto an MBH. Two major channels of MBH feedback, radiative feedback (X-ray photons followed through full three-dimensional adaptive ray tracing) and mechanical feedback (bipolar jets resolved in high-resolution AMR), are employed. We investigate the coevolution of a 9.2 x 10{sup 11} M {circle_dot} galactic halo and its 10{sup 5} {circle_dot} M embedded MBH at redshift 3 in a cosmological CDM simulation. The MBH feedback heats the surrounding interstellar medium (ISM) up to 10{sup 6} K through photoionization and Compton heating and locally suppresses star formation in the galactic inner core. The feedback considerably changes the stellar distribution there. This new channel of feedback from a slowly growing MBH is particularly interesting because it is only locally dominant and does not require the heating of gas globally on the disk. The MBH also self-regulates its growth by keeping the surrounding ISM hot for an extended period of time.

  1. Dynamic soil-structure interaction-comparison of FEM model with experimental results

    E-Print Network [OSTI]

    Srinivasan, Palanivel Rajan

    2000-01-01T23:59:59.000Z

    to represent twenty different laboratory experiments. The results of these models are compared with results available from extensive experimental dynamic testing on a geotechnical centrifuge. Though the various results from the finite element analysis...

  2. Transport-theoretic model for the electron-proton-hydrogen atom auroa. II. Model results

    SciTech Connect (OSTI)

    Strickland, D.J. [Computational Physics, Inc., Fairfax, VA (United States); Daniell, R.E. Jr. [Computational Physics, Inc., Newton, MA (United States); Basu, B. [Hanscom Air Force Base, MA (United States)] [and others

    1993-12-01T23:59:59.000Z

    In a companion paper, a self-consistent transport-theoretic model for the combined electron-proton-hydrogen atom aurora was described. In this paper, numberical results based on the model are presented. This is done for the pure electron aurora, the pure proton-hydrogen atom aurora, and finally for the combined aurora. Adopting commonly used types of energy distributions for the incident particle (electron and proton) fluxes, the authors give numerical solutions for the precipitating electron, proton, and hydrogen atom differential number fluxes. Results are also given for ionization yields and emission yields of the following features: N{sub 2}{sup +} first negative group (3914 {Angstrom}), N{sub 2} second positive group (3371 {Angstrom}), selected N{sub 2} Lyman-Birge-Hopfields bands (1325, 1354, 1383, 1493, and all bands between 1700 and 1800 {Angstrom}), O I (1356 {Angstrom}), L{sub {alpha}} (1216 {Angstrom}), H{sub {beta}} (4861 {Angstrom}), and H{sub {alpha}} (6563 {Angstrom}). The yield at 1493 {Angstrom} also contains a contribution from N I (1493 {Angstrom}), which in fact dominates LBH emission. A major new result of this study is that the secondary electron flux produced by the proton-hydrogen atom aurora is much softer than that produced by the electron aurora. This increased softness is due to the fact that (for energies of aurora interest) cross sections for secondary electron flux produced by the proton-hydrogen atom aurora is much softer than that produced by the electron aurora. This increased softness is due to the fact that (for energies of auroral interest) cross sections for secondary electron production by proton and hydrogen atom impact decrease exponentially with increasing secondary electron energy, whereas the cross sections for electron impact decrease as an inverse power law with increasing secondary energy.

  3. Models of the formation of oxide phases in nanostructured materials based on lead chalcogenides subjected to treatment in oxygen and iodine vapors

    SciTech Connect (OSTI)

    Maraeva, E. V., E-mail: jenvmar@mail.ru; Moshnikov, V. A.; Tairov, Yu. M. [St. Petersburg State Electrotechnical University 'LETI' (Russian Federation)] [St. Petersburg State Electrotechnical University 'LETI' (Russian Federation)

    2013-10-15T23:59:59.000Z

    Model concepts concerning control over the formation of oxide layers during the course of oxidation are developed on the basis of experimental results of studies of systematic features of the formation of nanostructured layers after diffusion annealing. Data on a variation in the composition of oxide phases as the extent of deviation from stoichiometry is changed in the initial lead chalcogenide are presented. Model concepts related to the possibility of varying the thickness of the coating oxide phases using annealing in an oxygen-containing medium are developed. It is shown that annealing in an iodine atmosphere ensures the effective penetration of oxygen into the grains, which is necessary for an increase in the photoluminescence efficiency.

  4. Computer modeling and simulation of Black Warrior Basin formation: Annual report for the 1987--1988 SOMED (School of Mines and Energy Development) project year

    SciTech Connect (OSTI)

    Visscher, P.B.

    1988-01-01T23:59:59.000Z

    Computer simulations have been performed, aimed at achieving a better understanding of the geological and physical processes involved in the formation of sedimentary basins in general and the Black Warrior basin of Alabama and Mississippi in particular. Microscopic-level computer modeling of sandstone porosity reduction has been done, elucidating the detailed small-scale dynamics which lead to the geological phenomenon of pressure solution. A new technique has been developed for 1D burial and thermal modeling of sedimentary basins based on stratigraphic data from test wells. It is significantly faster than previous methods, and can be used in interactive menu-oriented program requiring relatively little learning time or prior computer experience. This allows a geologist to rapidly determine the results of various different hypotheses about basin formation, providing insight which may help determine which is correct. A program has also been written to simulate tectonic-plate collisions and rifting processes using viscoelastic hydrodynamics.

  5. Observable Consequences of Planet Formation Models in Systems with Close-in Terrestrial Planets

    E-Print Network [OSTI]

    Sean N. Raymond; Rory Barnes; Avi M. Mandell

    2007-11-13T23:59:59.000Z

    To date, two planetary systems have been discovered with close-in, terrestrial-mass planets (planet; 4) formation from material being shepherded by moving secular resonances during dispersal of the protoplanetary disk; 5) tidal circularization of eccentric terrestrial planets with close-in perihelion distances; and 6) photo-evaporative mass loss of a close-in giant planet. Models 1-4 have been validated in previous work. We show that tidal circularization can form hot Earths, but only for relatively massive planets (> 5 Earth masses) with very close-in perihelion distances (planets of less than about 70 Earth masses, photo-evaporation can remove the planet's envelope and leave behind the solid core on a Gyr timescale, but only for planets inside 0.025-0.05 AU. Using two quantities that are observable by current and upcoming missions, we show that these models each produce unique signatures, and can be observationally distinguished. These observables are the planetary system architecture (detectable with radial velocities, transits and transit-timing) and the bulk composition of transiting close-in terrestrial planets (measured by transits via the planet's radius).

  6. Constitutive models for the Etchegoin Sands, Belridge Diatomite, and overburden formations at the Lost Hills oil field, California

    SciTech Connect (OSTI)

    FOSSUM,ARLO F.; FREDRICH,JOANNE T.

    2000-04-01T23:59:59.000Z

    This report documents the development of constitutive material models for the overburden formations, reservoir formations, and underlying strata at the Lost Hills oil field located about 45 miles northwest of Bakersfield in Kern County, California. Triaxial rock mechanics tests were performed on specimens prepared from cores recovered from the Lost Hills field, and included measurements of axial and radial stresses and strains under different load paths. The tested intervals comprise diatomaceous sands of the Etchegoin Formation and several diatomite types of the Belridge Diatomite Member of the Monterey Formation, including cycles both above and below the diagenetic phase boundary between opal-A and opal-CT. The laboratory data are used to drive constitutive parameters for the Extended Sandler-Rubin (ESR) cap model that is implemented in Sandia's structural mechanics finite element code JAS3D. Available data in the literature are also used to derive ESR shear failure parameters for overburden formations. The material models are being used in large-scale three-dimensional geomechanical simulations of the reservoir behavior during primary and secondary recovery.

  7. Modeling the Inhomogeneous Response and Formation of Shear Bands in Steady and

    E-Print Network [OSTI]

    of these models, the `flow curve' of stress and apparent shear rate resulting from an assumption of homogeneous de of Machanical Engineering, MIT 1 #12;1 Introduction A central assumption behind rheometry is that the velocity shampoos and body gels; in the petroleum industry they are used in fracturing operations and enhanced oil

  8. Effect of chain stiffness on the competition between crystallization and glass-formation in model colloidal polymers

    E-Print Network [OSTI]

    Hong T. Nguyen; Tyler B. Smith; Robert S. Hoy; Nikos Ch. Karayiannis

    2015-02-01T23:59:59.000Z

    We map out the solid-state morphologies formed by model soft-pearl-necklace polymers as a function of bending stiffness $k_b$ spanning the range from fully flexible to rodlike chains. The ratio of Kuhn length to bead diameter ($l_K/r_0$) increases monotonically with increasing $k_b$ and yields a one-parameter model that relates chain shape to bulk morphology and yields insights into the packing of anisotropic particles. In the flexible limit, monomers occupy the sites of close-packed crystallites while chains retain random-walk-like order. In the rodlike limit, nematic chain ordering typical of lamellar precursors coexists with close-packing. At intermediate values of bending stiffness the competition between random-walk-like and nematic chain ordering produces glass-formation; the range of $k_b$ over which this occurs increases with the thermal cooling rate $|\\dot{T}|$ implemented in our molecular dynamics simulations. Finally, values of $k_b$ between the glass-forming and rodlike ranges produce complex ordered phases such as close-packed spirals. Our results should prove useful for rational design of dense colloidal-polymer phases with desired morphologies.

  9. Leaching of BTEX from Aged Crude Oil Contaminated Model Soils: Experimental and Modeling Results

    SciTech Connect (OSTI)

    Huesemann, Michael H.; Hausmann, Tom S.; Fortman, Timothy J.

    2005-01-01T23:59:59.000Z

    It is generally assumed that soil properties such as organic matter content, porosity, and mineral surface area have a significant effect on the bioavailability and leachability of aged petroleum hydrocarbons. In order to test this hypothesis, nine model soils or sorbents (i.e., fine and coarse quartz sand, montmorillonite and kaolinite clay, peat, 60? and 150? silica gel, a loam soil, and non-porous glass beads) were spiked with a crude oil, aged for 27 months in the laboratory, and transferred to glass columns for the performance of continuous flow leaching experiments. The column effluents were periodically sampled for 43 days and analyzed for BTEX. A one-dimensional flow model for predicting the dissolution and dispersion of individual hydrocarbons from a multi-component NAPL such as crude oil was used to fit the leaching data (i.e., the BTEX concentration versus time curves) by adjusting the equilibrium oil-leachate partitioning coefficient (Kol) for each respective hydrocarbon. The Peclet number, which is a measure of dispersion and a required modeling parameter, was measured in separate chloride tracer experiments for each soil column. Results demonstrate that soil properties did not significantly affect the leaching kinetics of BTEX from the columns. Instead, BTEX leaching curves could be successfully fitted with the one-dimensional NAPL dissolution flow model for all sorbents with the exception of montmorillonite clay. The fitting parameter Kol for each hydrocarbon was found to be similar to the Kol values that were independently measured for the same crude oil by Rixey et al. (Journal of Hazardous Materials B, 65: 137-156, 1999). In addition, the fitted Kol values were very similar for BTEX leaching from aged compared to freshly spiked loam soil. These findings indicate that leaching of BTEX in the aged soils that are contaminated with crude oil at the high concentrations commonly found in the environment (i.e., >20,000 mg/kg) was not affected by soil properties or aging but rather was governed by the equilibrium dissolution of these hydrocarbons from the crude oil NAPL that is coating the soil particles.

  10. Fast 3D Modeling of Borehole Induction Measurements in Dipping and Anisotropic Formations using a Novel Approximation Technique

    E-Print Network [OSTI]

    Torres-Verdín, Carlos

    complex linear system of equations whose solution yields the spatial distribution of the internal electricFast 3D Modeling of Borehole Induction Measurements in Dipping and Anisotropic Formations using two sequential steps. First, the spatial distribution of the electric field within scatterers

  11. Source Contributions to VOC's to Ozone Formation in Southeast Texas Using a Source-oriented Air Quality Model 

    E-Print Network [OSTI]

    Krishnan, Anupama

    2011-08-08T23:59:59.000Z

    Houston-Galveston-Brazoria area is in severe non-attainment status for ozone compliance. Source-oriented mechanistic modeling was used to determine the major sources of VOCs that contributes to ozone formation during the Texas Air Quality Study (Tex...

  12. Source Contributions to VOC's to Ozone Formation in Southeast Texas Using a Source-oriented Air Quality Model

    E-Print Network [OSTI]

    Krishnan, Anupama

    2011-08-08T23:59:59.000Z

    Houston-Galveston-Brazoria area is in severe non-attainment status for ozone compliance. Source-oriented mechanistic modeling was used to determine the major sources of VOCs that contributes to ozone formation during the Texas Air Quality Study (Tex...

  13. Effect of Blade Torsion on Modeling Results for the Small Wind Research Turbine (SWRT): Preprint

    SciTech Connect (OSTI)

    Corbus, D.; Hansen, A. C.; Minnema, J.

    2006-01-01T23:59:59.000Z

    This paper summarizes modeling results from both the FAST and ADAMS aeroelastic simulators characterizing small wind turbine loads and dynamic behavior.

  14. Basin Analysis of Mississippi Interior Salt Basin and Petroleum System Modeling of the Jurassic Smackover Formation, Eastern Gulf Coastal Plain

    SciTech Connect (OSTI)

    Ernest Mancini

    2001-03-01T23:59:59.000Z

    Part 3 (Petroleum System Modeling of the Jurassic Smackover Formation) objectives are to provide an analysis of the Smackover petroleum system in Years 4 and 5 of the project and to transfer effectively the research results to producers through workshops and topical reports. Work Accomplished (Year 5): Task 1 - Basin Flow - Basin flow modeling has been completed and the topical report has been submitted to the U.S. DOE for review. Task 2 - Petroleum Source Rocks - Work on the characterization of Smackover petroleum source rocks has been integrated into the basin flow model. The information on the source rocks is being prepared for inclusion in the final report. Task 3 - Petroleum Reservoirs - Work on the characterization of Smackover petroleum reservoirs continues. The cores to be described have been identified and many of the cores for the eastern and western parts of the basin have been described. Task 4 - Reservoir Diagenesis - Work on reservoir diagenesis continues. Samples from the cores selected for the reservoir characterization are being used for this task. Task 5 - Underdeveloped Reservoirs - Two underdeveloped Smackover reservoirs have been identified. They are the microbial reef and shoal reservoirs. Work Planned (Year 5): Task 1 - Basin Flow - This task has been completed and the topical report has been submitted to the U.S. DOE. Task 2 - Petroleum Source Rocks - Petroleum source rock information will continue to be prepared for the final report. Task 3 - Petroleum Reservoirs - Characterization of petroleum reservoirs will continue through core studies. Task 4 - Reservoir Diagenesis - Characterization of reservoir diagenesis will continue through petrographic analysis. Task 5 - Underdeveloped Reservoirs - Study of Smackover underdeveloped reservoirs will continue with focus on the microbial reef and shoal reservoirs.

  15. Efficient Dynamic Modeling, Numerical Optimal Control and Experimental Results for Various Gaits

    E-Print Network [OSTI]

    Stryk, Oskar von

    Efficient Dynamic Modeling, Numerical Optimal Control and Experimental Results for Various Gaits. A fully three- dimensional dynamical model of Sony's four-legged robot is used to state an optimal control model and the algorithm for evaluating the dynamics. The formulation of the optimal control problem

  16. Haptic Models of an Automotive Turn-Signal Switch: Identification and Playback Results

    E-Print Network [OSTI]

    Hollerbach, John M.

    Haptic Models of an Automotive Turn-Signal Switch: Identification and Playback Results Mark B of virtual environments. This paper addresses the problem of modeling the feel of an automotive turn- signal would require accurate models of the primary automotive controls, including the steering wheel, gear

  17. Modeling of metallic aerosol formation in a multicomponent system at high temperatures using a discrete-sectional model. Appendix 7

    SciTech Connect (OSTI)

    NONE

    1997-02-01T23:59:59.000Z

    A multicomponent discrete-sectional model was used to simulate the fate of lead in a high temperature system. The results show the ability of the developed model to simulate metallic aerosol systems at high temperatures. The PbO reaction and nucleation rate can be determined by comparing the simulations and the experimental data. Condensation on SiO{sub 2} particle surfaces is found important for removing the PbO vapor. The value of the accommodation factor that is applied to account for nonidealities in the condensation process are determined. The differences between the nanosized particles and the bulk particles are elucidated. The use of such a model helped to understand the effects of various mechanisms in determining the metal oxide vapor concentration profile and in establishing the ultimate particle size distribution.

  18. Comparison of Statistical Multifragmentation Model simulations with Canonical Thermodynamical Model results: a few representative cases

    E-Print Network [OSTI]

    A. Botvina; G. Chaudhuri; S. Das Gupta; I. Mishustin

    2008-05-22T23:59:59.000Z

    The statistical multifragmentation model (SMM) has been widely used to explain experimental data of intermediate energy heavy ion collisions. A later entrant in the field is the canonical thermodynamic model (CTM) which is also being used to fit experimental data. The basic physics of both the models is the same, namely that fragments are produced according to their statistical weights in the available phase space. However, they are based on different statistical ensembles, and the methods of calculation are different: while the SMM uses Monte-Carlo simulations, the CTM solves recursion relations. In this paper we compare the predictions of the two models for a few representative cases.

  19. Cost Benefit Analysis Modeling Tool for Electric vs. ICE Airport Ground Support Equipment – Development and Results

    SciTech Connect (OSTI)

    James Francfort; Kevin Morrow; Dimitri Hochard

    2007-02-01T23:59:59.000Z

    This report documents efforts to develop a computer tool for modeling the economic payback for comparative airport ground support equipment (GSE) that are propelled by either electric motors or gasoline and diesel engines. The types of GSE modeled are pushback tractors, baggage tractors, and belt loaders. The GSE modeling tool includes an emissions module that estimates the amount of tailpipe emissions saved by replacing internal combustion engine GSE with electric GSE. This report contains modeling assumptions, methodology, a user’s manual, and modeling results. The model was developed based on the operations of two airlines at four United States airports.

  20. The response of a capacitively coupled discharge to the formation of dust particles: Experiments and modeling

    SciTech Connect (OSTI)

    Denysenko, I.; Berndt, J.; Kovacevic, E.; Stefanovic, I.; Selenin, V.; Winter, J. [School of Physics and Technology, V. N. Karazin Kharkiv National University, Svobody sq. 4, 61077 Kharkiv (Ukraine); Institute of Experimental Physics II, Ruhr-University Bochum, D-44780 Bochum (Germany); Institute of Experimental Physics II, Ruhr-University Bochum, D-44780 Bochum, Germany and Institute of Physics, POB 57, 11001 Belgrade (Serbia and Montenegro); Institute of Experimental Physics II, Ruhr-University Bochum, D-44780 Bochum (Germany)

    2006-07-15T23:59:59.000Z

    The influence of dust particles on the properties of a capacitively coupled Ar-C{sub 2}H{sub 2} discharge is studied both experimentally and theoretically. The results of measurements of the intensity and spatial distribution of the emitted light, the line width of the fast component of H{sub {alpha}} line and of the electron density during the particle growth are presented. To analyze the experimental results a one-dimensional discharge model is developed. Using the model the effects of dust grains on the power absorption (taking into account stochastic and Ohmic heating in the plasma sheaths), the optical emission intensity profile, the sheath size, the rf electric field and on the energy of positive ions bombarding the electrodes are investigated. In particular, it is shown that the decrease of the power absorption in the sheaths of complex plasmas is due to the dependence of the stochastic and Ohmic heating in the plasma sheaths on the electron temperature and the current flowing across the discharge plates. The results of the calculations are compared with the available experimental data and found to be in good agreement.

  1. Uncertainty in the reactive transport model response to an alkaline perturbation in a clay formation

    E-Print Network [OSTI]

    Burnol, A.; Blanc, P.; Xu, T.; Spycher, N.; Gaucher, E.C.

    2006-01-01T23:59:59.000Z

    degradation of a concrete/clay interface, in Migration'05 -an alkaline plume in a clay barrier, Applied Geochemistry,AN ALKALINE PERTURBATION IN A CLAY FORMATION A. Burnol*, P.

  2. Simplified Model of a Flux-Pinned Spacecraft Formation Michael C. Norman

    E-Print Network [OSTI]

    Peck, Mason A.

    state-feedback control law. This framework is then applied to a simplified two-spacecraft formation vector ^s and b2 about ^w 2 = angle between unit vector ^w and b3 about b1 = standard gravitational

  3. The Multi-Stage Investment Timing Game in Offshore Petroleum Production: Preliminary results from an econometric model

    E-Print Network [OSTI]

    Lin, C.-Y. Cynthia

    2007-01-01T23:59:59.000Z

    robustness checks from the econometric model coefficients inPreliminary results from an econometric model C. -Y.paper uses a structural econometric model to analyze the

  4. Multi-epoch very long baseline interferometric observations of the nuclear starburst region of NGC 253: Improved modeling of the supernova and star formation rates

    SciTech Connect (OSTI)

    Rampadarath, H.; Morgan, J. S.; Tingay, S. J. [International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth, WA (Australia); Lenc, E., E-mail: hayden.rampadarath@icrar.org [Sydney Institute for Astronomy, School of Physics, The University of Sydney, NSW (Australia)

    2014-01-01T23:59:59.000Z

    The results of multi-epoch observations of the southern starburst galaxy, NGC 253, with the Australian Long Baseline Array at 2.3 GHz are presented. As with previous radio interferometric observations of this galaxy, no new sources were discovered. By combining the results of this survey with Very Large Array observations at higher frequencies from the literature, spectra were derived and a free-free absorption model was fitted of 20 known sources in NGC 253. The results were found to be consistent with previous studies. The supernova remnant, 5.48-43.3, was imaged with the highest sensitivity and resolution to date, revealing a two-lobed morphology. Comparisons with previous observations of similar resolution give an upper limit of 10{sup 4} km s{sup –1} for the expansion speed of this remnant. We derive a supernova rate of <0.2 yr{sup –1} for the inner 300 pc using a model that improves on previous methods by incorporating an improved radio supernova peak luminosity distribution and by making use of multi-wavelength radio data spanning 21 yr. A star formation rate of SFR(M ? 5 M {sub ?}) < 4.9 M {sub ?} yr{sup –1} was also estimated using the standard relation between supernova and star formation rates. Our improved estimates of supernova and star formation rates are consistent with studies at other wavelengths. The results of our study point to the possible existence of a small population of undetected supernova remnants, suggesting a low rate of radio supernova production in NGC 253.

  5. Three-Dimensional Thermal-Electrochemical Coupled Model for Spirally Wound Large-Format Lithium-Ion Batteries (Presentation)

    SciTech Connect (OSTI)

    Lee, K. J.; Smith K.; Kim, G. H.

    2011-04-01T23:59:59.000Z

    This presentation discusses the behavior of spirally wound large-format Li-ion batteries with respect to their design. The objectives of the study include developing thermal and electrochemical models resolving 3-dimensional spirally wound structures of cylindrical cells, understanding the mechanisms and interactions between local electrochemical reactions and macroscopic heat and electron transfers, and developing a tool and methodology to support macroscopic designs of cylindrical Li-ion battery cells.

  6. Basin Analysis of the Mississippi Interior Salt Basin and Petroleum System Modeling of the Jurassic Smackover Formation, Eastern Gulf Coastal Plain

    SciTech Connect (OSTI)

    Ernest Mancini

    2000-12-31T23:59:59.000Z

    Part 3 (Petroleum System Modeling of the Jurassic Smackover Formation) objectives are to provide an analysis of the Smackover petroleum system in Years 4 and 5 of the project and to transfer effectively the research results to producers through workshops and topical reports. Work Accomplished (Year 5): Task 1 - Basin Flow - Basin flow modeling has been completed and the modeling results are being interpreted for report writing (Table 1). Task 2 - Petroleum Source Rocks - Work on the characterization of Smackover petroleum source rocks has been integrated into the basin flow model. Task 3 - Petroleum Reservoirs - Work on the characterization of Smackover petroleum reservoirs continues. The cores to be described have been identified and many of the cores for the eastern part of the basin have been described. Task 4 - Reservoir Diagenesis - Work on reservoir diagenesis has been initiated. Samples from the cores selected for the reservoir characterization are being used for this task. Work Planned (Year 5): Task 1 - Basin Flow - The report on basin flow will be completed. Task 2 - Petroleum Source Rocks - Petroleum source rock data will be reviewed in light of the basin flow model results. Task 3 - Petroleum Reservoirs - Characterization of petroleum reservoirs will continue through core studies. Task 4 - Reservoir Diagenesis - Characterization of reservoir diagenesis will continue through petrographic analysis.

  7. 2D-Modelling of pellet injection in the poloidal plane: results of numerical tests

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    2D-Modelling of pellet injection in the poloidal plane: results of numerical tests P. Lalousis developed for computing the expansion of pellet-produced clouds in the poloidal plane. The expansion

  8. A Statistical Model for Linking Field and Laboratory Exposure Results for a Model Coating

    E-Print Network [OSTI]

    and Technology (NIST) to generate necessary experimental data and the development of a model relating cumulative fundamental understanding of the underlying degradation mechanisms and conclusions from them can be seriously of materials in certain applications. These range from jet engine turbine disk materials to highly #12

  9. Dynamic Friction Models for Longitudinal Road/Tire Interaction: Experimental Results

    E-Print Network [OSTI]

    Tsiotras, Panagiotis

    Dynamic Friction Models for Longitudinal Road/Tire Interaction: Experimental Results C. Canudas dynamic friction force model for the longitudinal road/tire interaction for wheeled ground vehicles is val- idated via experiments with an actual passenger vehicle. Contrary to common static friction/slip maps

  10. Evaluation of Advanced Wind Power Forecasting Models Results of the Anemos Project

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Evaluation of Advanced Wind Power Forecasting Models ­ Results of the Anemos Project I. Martí1.kariniotakis@ensmp.fr Abstract An outstanding question posed today by end-users like power system operators, wind power producers or traders is what performance can be expected by state-of-the-art wind power prediction models. This paper

  11. Combinatorial Algorithms for Protein Folding in Lattice Models: A Survey of Mathematical Results

    E-Print Network [OSTI]

    Istrail, Sorin

    Combinatorial Algorithms for Protein Folding in Lattice Models: A Survey of Mathematical Results a comprehensive survey of combinatorial algorithms and theorems about lattice protein folding models obtained in the almost 15 years since the publication in 1995 of the first protein folding approximation algorithm

  12. The International Urban Energy Balance Models Comparison Project: First Results from Phase 1

    E-Print Network [OSTI]

    Ribes, Aurélien

    The International Urban Energy Balance Models Comparison Project: First Results from Phase 1 C. S and Kapodistrian University of Athens, Athens, Greece h University of Lo´ dz´, Lo´ dz´, Poland i Royal) ABSTRACT A large number of urban surface energy balance models now exist with different assumptions about

  13. Election Results and Opportunistic Policies: A New Test of the Rational Political Business Cycle Model

    E-Print Network [OSTI]

    Aidt, Toke S; Veiga, F J; Veiga, L G

    Election Results and Opportunistic Policies: A New Test of the Rational Political Business Cycle Model#3; Toke S. Aidtay Francisco José Veigab Linda Gonçalves Veigac aUniversity of Cambridge, Faculty of Economics, Sidgwick Avenue Cambridge, CB3 9DD... . These results are consistent with the theoretical model. Keywords: Voting and popularity functions, opportunism, rational political busi- ness cycles, local government, system estimation, Portugal. JEL codes: D72, E32, H72. #3;The authors acknowledge helpful...

  14. Integrated Assessment Modeling of Carbon Sequestration and Land Use Emissions Using Detailed Model Results and Observations

    SciTech Connect (OSTI)

    Dr. Atul Jain

    2005-04-17T23:59:59.000Z

    This report outlines the progress on the development and application of Integrated Assessment Modeling of Carbon Sequestrations and Land Use Emissions supported by the DOE Office of Biological and Environmental Research (OBER), U.S. Department of Energy, Grant No. DOE-DE-FG02-01ER63069. The overall objective of this collaborative project between the University of Illinois at Urbana-Champaign (UIUC), Oak Ridge National Laboratory (ORNL), Lawrence Livermore National Laboratory (LLNL), and Pacific Northwest National Laboratory (PNNL) was to unite the latest advances in carbon cycle research with scientifically based models and policy-related integrated assessment tools that incorporate computationally efficient representations of the latest knowledge concerning science and emission trajectories, and their policy implications. As part of this research we accomplished the following tasks that we originally proposed: (1) In coordination with LLNL and ORNL, we enhanced the Integrated Science Assessment Model's (ISAM) parametric representation of the ocean and terrestrial carbon cycles that better represent spatial and seasonal variations, which are important to study the mechanisms that influence carbon sequestration in the ocean and terrestrial ecosystems; (2) Using the MiniCAM modeling capability, we revised the SRES (IPCC Special Report on Emission Scenarios; IPCC, 2000) land use emission scenarios; and (3) On the application front, the enhanced version of ISAM modeling capability is applied to understand how short- and long-term natural carbon fluxes, carbon sequestration, and human emissions contribute to the net global emissions (concentrations) trajectories required to reach various concentration (emission) targets. Under this grant, 21 research publications were produced. In addition, this grant supported a number of graduate and undergraduate students whose fundamental research was to learn a disciplinary field in climate change (e.g., ecological dynamics and ocean circulations) and then complete research on how this field could be linked to the other factors we need to consider in its dynamics (e.g., land use, ocean and terrestrial carbon sequestration and climate change).

  15. Modeling of fate and transport of co-injection of H2S with CO2 in deep saline formations

    SciTech Connect (OSTI)

    Zhang, W.; Xu, T.; Li, Y.

    2010-12-15T23:59:59.000Z

    The geological storage of CO{sub 2} in deep saline formations is increasing seen as a viable strategy to reduce the release of greenhouse gases into the atmosphere. However, costs of capture and compression of CO{sub 2} from industrial waste streams containing small quantities of sulfur and nitrogen compounds such as SO{sub 2}, H{sub 2}S and N{sub 2} are very expensive. Therefore, studies on the co-injection of CO{sub 2} containing other acid gases from industrial emissions are very important. In this paper, numerical simulations were performed to study the co-injection of H{sub 2}S with CO{sub 2} in sandstone and carbonate formations. Results indicate that the preferential dissolution of H{sub 2}S gas (compared with CO{sub 2} gas) into formation water results in the delayed breakthrough of H{sub 2}S gas. Co-injection of H{sub 2}S results in the precipitation of pyrite through interactions between the dissolved H{sub 2}S and Fe{sup 2+} from the dissolution of Fe-bearing minerals. Additional injection of H{sub 2}S reduces the capabilities for solubility and mineral trappings of CO{sub 2} compared to the CO{sub 2} only case. In comparison to the sandstone (siliciclastic) formation, the carbonate formation is less favorable to the mineral sequestration of CO{sub 2}. Different from CO{sub 2} mineral trapping, the presence of Fe-bearing siliciclastic and/or carbonate is more favorable to the H{sub 2}S mineral trapping.

  16. Results and Comparison from the SAM Linear Fresnel Technology Performance Model: Preprint

    SciTech Connect (OSTI)

    Wagner, M. J.

    2012-04-01T23:59:59.000Z

    This paper presents the new Linear Fresnel technology performance model in NREL's System Advisor Model. The model predicts the financial and technical performance of direct-steam-generation Linear Fresnel power plants, and can be used to analyze a range of system configurations. This paper presents a brief discussion of the model formulation and motivation, and provides extensive discussion of the model performance and financial results. The Linear Fresnel technology is also compared to other concentrating solar power technologies in both qualitative and quantitative measures. The Linear Fresnel model - developed in conjunction with the Electric Power Research Institute - provides users with the ability to model a variety of solar field layouts, fossil backup configurations, thermal receiver designs, and steam generation conditions. This flexibility aims to encompass current market solutions for the DSG Linear Fresnel technology, which is seeing increasing exposure in fossil plant augmentation and stand-alone power generation applications.

  17. Summary Results for Brine Migration Modeling Performed by LANL LBNL and SNL for the UFD Program

    SciTech Connect (OSTI)

    Kuhlman, Kristopher L

    2014-09-01T23:59:59.000Z

    This report summarizes laboratory and field observations and numerical modeling related to coupled processes involving brine and vapor migration in geologic salt, focusing on recent developments and studies conducted at Sandia, Los Alamos, and Berkeley National Laboratories. Interest into the disposal of heat-generating waste in salt has led to interest into water distribution and migration in both run-of-mine crushed and intact geologic salt. Ideally a fully coupled thermal-hydraulic-mechanical-chemical simulation is performed using numerical models with validated constitutive models and parameters. When mechanical coupling is not available, mechanical effects are prescribed in hydraulic models as source, boundary, or initial conditions. This report presents material associated with developing appropriate initial conditions for a non-mechanical hydrologic simulation of brine migration in salt. Due to the strong coupling between the mechanical and hydrologic problems, the initial saturation will be low for the excavation disturbed zone surrounding the excavation. Although most of the material in this report is not new, the author hopes it is presented in a format making it useful to other salt researchers.

  18. MODELING THE POREWATER CHEMISTRY OF THE CALLOVIAN-OXFORDIAN FORMATION AT A REGIONAL SCALE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , France 2 ANDRA, 1-7 rue Jean Monnet , 92298 Châtenay-Malabry, France 3 ANTEA, 3 avenue C. Guillemin, BP 6009, Orléans 45061, France 4 ANDRA, Lab. Meuse/Haute Marne, Cd 960, 55290 Bure, France * Corresponding, France), pour étudier la faisabilité d'un stockage profond de déchets radioactifs au sein de la formation

  19. Experimental and artificial neural network modeling study on soot formation in premixed hydrocarbon flamesq

    E-Print Network [OSTI]

    Senkan, Selim M.

    The formation of soot in premixed flames of methane, ethane, propane, and butane was studied at three different particle diameters at higher distances above the burner surface and propane, ethane, and butane flames came conditions in humans. Polycyclic aromatic hydro- carbons (PAH), the largest class of chemical carcinogens

  20. COMPUTATIONAL FLUID DYNAMICS MODELING OF SCALED HANFORD DOUBLE SHELL TANK MIXING - CFD MODELING SENSITIVITY STUDY RESULTS

    SciTech Connect (OSTI)

    JACKSON VL

    2011-08-31T23:59:59.000Z

    The primary purpose of the tank mixing and sampling demonstration program is to mitigate the technical risks associated with the ability of the Hanford tank farm delivery and celtification systems to measure and deliver a uniformly mixed high-level waste (HLW) feed to the Waste Treatment and Immobilization Plant (WTP) Uniform feed to the WTP is a requirement of 24590-WTP-ICD-MG-01-019, ICD-19 - Interface Control Document for Waste Feed, although the exact definition of uniform is evolving in this context. Computational Fluid Dynamics (CFD) modeling has been used to assist in evaluating scaleup issues, study operational parameters, and predict mixing performance at full-scale.

  1. Structure formation: a spherical model for the evolution of the density distribution

    E-Print Network [OSTI]

    P. Valageas

    1998-07-02T23:59:59.000Z

    Within the framework of hierarchical clustering we show that a simple Press-Schechter-like approximation, based on spherical dynamics, provides a good estimate of the evolution of the density field in the quasi-linear regime up to $\\Sigma \\sim 1$. Moreover, it allows one to recover the exact series of the cumulants of the probability distribution of the density contrast in the limit $\\Sigma \\to 0$ which sheds some light on the rigorous result and on ``filtering''. We also obtain similar results for the divergence of the velocity field. Next, we extend this prescription to the highly non-linear regime, using a stable-clustering approximation. Then we recover a specific scaling of the counts-in-cells which is indeed seen in numerical simulations, over a well-defined range. To this order we also introduce an explicit treatment of the behaviour of underdensities, which takes care of the normalization and is linked to the low-density bubbles and the walls one can see in numerical simulations. We compare this to a 1-dimensional adhesion model, and we present the consequences of our prescription for the power-law tail and the cutoff of the density distribution.

  2. NUMERICAL MODELING FOR THE FORMATION MECHANISM OF 3D TOPOGRAPHY ON MICROBIAL MAT SURFACES 

    E-Print Network [OSTI]

    Patel, Harsh Jay

    2013-09-27T23:59:59.000Z

    determined. A deterministic model includes both a dynamic model, and a static model. Compared to a deterministic solute diffusion model, a stochastic diffusion model has one or more stochastic elements. Concentration diffusion system formulated... solute diffusion equation, which merely appears in the form of a number line, the quasi-2D solute diffusion equation forms a Cartesian grid system. Also, for the explicit quasi-2D solute diffusion equation (Eq. 4), concentration variation is measured...

  3. Predictive Modelling of Toxicity Resulting from Radiotherapy Treatments of Head and Neck Cancer

    E-Print Network [OSTI]

    Dean, Jamie A; Harrington, Kevin J; Nutting, Christopher M; Gulliford, Sarah L

    2014-01-01T23:59:59.000Z

    In radiotherapy for head and neck cancer, the radiation dose delivered to the pharyngeal mucosa (mucosal lining of the throat) is thought to be a major contributing factor to dysphagia (swallowing dysfunction), the most commonly reported severe toxicity. There is a variation in the severity of dysphagia experienced by patients. Understanding the role of the dose distribution in dysphagia would allow improvements in the radiotherapy technique to be explored. The 3D dose distributions delivered to the pharyngeal mucosa of 249 patients treated as part of clinical trials were reconstructed. Pydicom was used to extract DICOM (digital imaging and communications in medicine) data (the standard file formats for medical imaging and radiotherapy data). NumPy and SciPy were used to manipulate the data to generate 3D maps of the dose distribution delivered to the pharyngeal mucosa and calculate metrics describing the dose distribution. Multivariate predictive modelling of severe dysphagia, including descriptions of the d...

  4. Atmospheric Modelling for Neptune's Methane D/H Ratio - Preliminary Results

    E-Print Network [OSTI]

    Cotton, Daniel V; Bott, Kimberly; Bailey, Jeremy

    2015-01-01T23:59:59.000Z

    The ratio of deuterium to hydrogen (D/H ratio) of Solar System bodies is an important clue to their formation histories. Here we fit a Neptunian atmospheric model to Gemini Near Infrared Spectrograph (GNIRS) high spectral resolution observations and determine the D/H ratio in methane absorption in the infrared H-band ($\\sim$ 1.6 {\\mu}m). The model was derived using our radiative transfer software VSTAR (Versatile Software for the Transfer of Atmospheric Radiation) and atmospheric fitting software ATMOF (ATMOspheric Fitting). The methane line list used for this work has only become available in the last few years, enabling a refinement of earlier estimates. We identify a bright region on the planetary disc and find it to correspond to an optically thick lower cloud. Our preliminary determination of CH$_{\\rm 3}$D/CH$_{\\rm 4}$ is 3.0$\\times10^{-4}$, which is in line with the recent determination of Irwin et al. (2014) of 3.0$^{+1.0}_{-0.9}\\sim\\times10^{-4}$, made using the same model parameters and line list but...

  5. Gearbox Reliability Collaborative Phase 1 and 2: Testing and Modeling Results; Preprint

    SciTech Connect (OSTI)

    Keller, J.; Guo, Y.; LaCava, W.; Link, H.; McNiff, B.

    2012-05-01T23:59:59.000Z

    The Gearbox Reliability Collaborative (GRC) investigates root causes of wind turbine gearbox premature failures and validates design assumptions that affect gearbox reliability using a combined testing and modeling approach. Knowledge gained from the testing and modeling of the GRC gearboxes builds an understanding of how the selected loads and events translate into internal responses of three-point mounted gearboxes. This paper presents some testing and modeling results of the GRC research during Phase 1 and 2. Non-torque loads from the rotor including shaft bending and thrust, traditionally assumed to be uncoupled with gearbox, affect gear and bearing loads and resulting gearbox responses. Bearing clearance increases bearing loads and causes cyclic loading, which could contribute to a reduced bearing life. Including flexibilities of key drivetrain subcomponents is important in order to reproduce the measured gearbox response during the tests using modeling approaches.

  6. A one-dimensional model illustrating virtual-cathode formation in a novel coaxial virtual-cathode oscillator

    SciTech Connect (OSTI)

    Turner, Geoffrey R., E-mail: gturner@csir.co.za [Council for Scientific and Industrial Research, PO Box 395, Pretoria 0001 (South Africa)

    2014-09-15T23:59:59.000Z

    A one-dimensional electrostatic sheet model of a coaxial geometry Virtual Cathode Oscillator (VCO) is presented. The cathode is centrally located and connects to a peripherally located plate electrode to form a resonant cavity, and is thus considered to be a novel design. Charge is modelled as concentric sheets about the cathode whose absolute position and velocity are determined as a function of time by solving the relativistic equations of motion. The model predicts the formation of a virtual cathode between the grid and plate electrodes for the case of a space-charge limited current. Setting the electron reflexing frequency (as a function of the grid potential) comparable with the cavity resonant frequency is predicted to improve the efficiency of microwave emission.

  7. SIMULATION MODEL ANALYSIS OF THE MOST PROMISING GEOLOGIC SEQUESTRATION FORMATION CANDIDATES IN THE ROCKY MOUNTAIN REGION, USA, WITH FOCUS ON UNCERTAINTY ASSESSMENT

    SciTech Connect (OSTI)

    Lee, Si-Yong; Zaluski, Wade; Will, Robert; Eisinger, Chris; Matthews, Vince; McPherson, Brian

    2013-09-01T23:59:59.000Z

    The purpose of this report is to report results of reservoir model simulation analyses for forecasting subsurface CO2 storage capacity estimation for the most promising formations in the Rocky Mountain region of the USA. A particular emphasis of this project was to assess uncertainty of the simulation-based forecasts. Results illustrate how local-scale data, including well information, number of wells, and location of wells, affect storage capacity estimates and what degree of well density (number of wells over a fixed area) may be required to estimate capacity within a specified degree of confidence. A major outcome of this work was development of a new workflow of simulation analysis, accommodating the addition of “random pseudo wells” to represent virtual characterization wells.

  8. Self-avoiding worm-like chain model for dsDNA loop formation

    E-Print Network [OSTI]

    Yaroslav Pollak; Sarah Goldberg; Roee Amit

    2014-11-06T23:59:59.000Z

    We compute for the first time the effects of excluded volume on the probability for double-stranded DNA to form a loop. We utilize a Monte-Carlo algorithm for generation of large ensembles of self- avoiding worm-like chains, which are used to compute the J-factor for varying lengthscales. In the entropic regime, we confirm the scaling-theory prediction of a power-law drop off of -1.92, which is significantly stronger than the -1.5 power-law predicted by the non-self-avoiding worm-like chain model. In the elastic regime, we find that the angle-independent end-to-end chain distribution is highly anisotropic. This anisotropy, combined with the excluded volume constraints, lead to an increase in the J-factor of the self-avoiding worm-like chain by about half an order of magnitude relative to its non-self-avoiding counterpart. This increase could partially explain the anomalous results of recent cyclization experiments, in which short dsDNA molecules were found to have an increased propensity to form a loop.

  9. Simulating the formation of massive seed black holes in the early Universe. I: An improved chemical model

    E-Print Network [OSTI]

    Glover, Simon

    2015-01-01T23:59:59.000Z

    The direct collapse model for the formation of massive seed black holes in the early Universe attempts to explain the observed number density of supermassive black holes (SMBHs) at $z \\sim 6$ by assuming that they grow from seeds with masses M > 10000 solar masses that form by the direct collapse of metal-free gas in atomic cooling halos in which H2 cooling is suppressed by a strong extragalactic radiation field. The viability of this model depends on the strength of the radiation field required to suppress H2 cooling, $J_{\\rm crit}$: if this is too large, then too few seeds will form to explain the observed number density of SMBHs. In order to determine $J_{\\rm crit}$ reliably, we need to be able to accurately model the formation and destruction of H2 in gas illuminated by an extremely strong radiation field. In this paper, we use a reaction-based reduction technique to analyze the chemistry of H2 in these conditions, allowing us to identify the key chemical reactions that are responsible for determining the...

  10. Combining Semi-Analytic Models of Galaxy Formation with Simulations of Galaxy Clusters: the Need for AGN Heating

    E-Print Network [OSTI]

    Short, C J

    2009-01-01T23:59:59.000Z

    We present hydrodynamical N-body simulations of clusters of galaxies with feedback taken from semi-analytic models of galaxy formation. The advantage of this technique is that the source of feedback in our simulations is a population of galaxies that closely resembles that found in the real universe. We demonstrate that, to achieve the high entropy levels found in clusters, active galactic nuclei must inject a large fraction of their energy into the intergalactic/intracluster media throughout the growth period of the central black hole. These simulations reinforce the argument of Bower et al. (2008), who arrived at the same conclusion on the basis of purely semi-analytic reasoning.

  11. COLD GASS, an IRAM Legacy Survey of Molecular Gas in Massive Galaxies: III. Comparison with semi-analytic models of galaxy formation

    E-Print Network [OSTI]

    Kauffmann, Guinevere; Fu, Jian; Saintonge, Amelie; Catinella, Barbara; Tacconi, Linda J; Kramer, Carsten; Genzel, Reinhard; Moran, Sean; Schiminovich, David

    2012-01-01T23:59:59.000Z

    We compare the semi-analytic models of galaxy formation of Fu et al. (2010), which track the evolution of the radial profiles of atomic and molecular gas in galaxies, with gas fraction scaling relations derived from the COLD GASS survey (Saintonge et al 2011). The models provide a good description of how condensed baryons in galaxies with gas are partitioned into stars, atomic and molecular gas as a function of galaxy stellar mass and surface density. The models do not reproduce the tight observed relation between stellar surface density and bulge-to-disk ratio for this population. We then turn to an analysis of the"quenched" population of galaxies without detectable cold gas. The current implementation of radio-mode feedback in the models disagrees strongly with the data. In the models, gas cooling shuts down in nearly all galaxies in dark matter halos above a mass of 10**12 M_sun. As a result, stellar mass is the observable that best predicts whether a galaxy has little or no neutral gas. In contrast, our d...

  12. Forward Modeling of the Induction Log Response of a Fractured Geologic Formation

    E-Print Network [OSTI]

    Bray, Steven Hunter

    2013-05-02T23:59:59.000Z

    3.1 Layered Earth Model The environment used for the induction log simulations is a layered Earth model. The model consists of six layers that are assigned different thicknesses and conductivities based on the desired induction log... Tx-Rx pair has a fixed separation and is moved along a vertical profile through the subsurface taking measurements at predetermined logging points. 20 The second change to the original Seatem code involves the surrounding environment. The code...

  13. Forward Modeling of the Induction Log Response of a Fractured Geologic Formation 

    E-Print Network [OSTI]

    Bray, Steven Hunter

    2013-05-02T23:59:59.000Z

    3.1 Layered Earth Model The environment used for the induction log simulations is a layered Earth model. The model consists of six layers that are assigned different thicknesses and conductivities based on the desired induction log... Tx-Rx pair has a fixed separation and is moved along a vertical profile through the subsurface taking measurements at predetermined logging points. 20 The second change to the original Seatem code involves the surrounding environment. The code...

  14. A Heuristic Model of DansgaardOeschger Cycles. Part I: Description, Results, and Sensitivity Studies

    E-Print Network [OSTI]

    Battisti, David

    . Parameterizations are included for latent heat polynyas and sea ice export from the column. The resulting heuristic representing the Nordic seas and is composed of ocean boxes stacked below a one-layer sea ice model in the proxy observational data, with the presence or absence of perennial sea ice in the Nordic seas being

  15. Modeling and simulation results on high sensitivity scattered gamma-ray emission imaging

    E-Print Network [OSTI]

    Nguyen-Verger, Maï K.

    Modeling and simulation results on high sensitivity scattered gamma-ray emission imaging C. Driol a simulations Numerical image reconstruction a b s t r a c t A new modality in gamma-ray emission imaging, based modality in gamma-ray emission imaging with potential applications in many fields such as bio

  16. TURBULENT COMBUSTION MODELING OF COAL:BIOMASS BLENDS IN A SWIRL BURNER I -PRELIMINARY RESULTS

    E-Print Network [OSTI]

    Daripa, Prabir

    coal or by ex- haust clean up technology. For the power plants, the simplest solution is the preventive- ity well into the 21st century. This dependency on coal calls for better technologies to reduceTURBULENT COMBUSTION MODELING OF COAL:BIOMASS BLENDS IN A SWIRL BURNER I - PRELIMINARY RESULTS

  17. Recent results from the UrQMD hybrid model for heavy ion collisions

    E-Print Network [OSTI]

    Bleicher, Marcus; Steinheimer, Jan; van Hees, Hendrik

    2015-01-01T23:59:59.000Z

    These proceedings present recent results from transport-hydrodynamics-hybrid models for heavy ion collisions at relativistic energies. The main focus is on the absorption of (anti-)protons in the hadronic afterburner stage of the reaction, di-lepton production at SPS and heavy quark dynamics.

  18. Computer representation of the model covariance function resulting from travel-time tomography

    E-Print Network [OSTI]

    Cerveny, Vlastislav

    Computer representation of the model covariance function resulting from travel-time tomography Lud a supplement to the paper by Klime#20;s (2002b) on the stochastic travel{time tomography. It contains brief covariance function is a function of 6 coordinates with pro- nounced singularities. The computer

  19. Methyl Formate Oxidation: Speciation Data, Laminar Burning Velocities, Ignition Delay Times and a Validated Chemical Kinetic Model

    SciTech Connect (OSTI)

    Dooley, S.; Burke, M. P.; Chaos, M.; Stein, Y.; Dryer, F. L.; Zhukov, V. P.; Finch, O.; Simmie, J. M.; Curran, H. J.

    2010-01-01T23:59:59.000Z

    The oxidation of methyl formate (CH{sub 3}OCHO) has been studied in three experimental environments over a range of applied combustion relevant conditions: 1. A variable-pressure flow reactor has been used to quantify reactant, major intermediate and product species as a function of residence time at 3 atm and 0.5% fuel concentration for oxygen/fuel stoichiometries of 0.5, 1.0, and 1.5 at 900 K, and for pyrolysis at 975 K. 2. Shock tube ignition delays have been determined for CH{sub 3}OCHO/O{sub 2}/Ar mixtures at pressures of ? 2.7, 5.4, and 9.2 atm and temperatures of 1275–1935 K for mixture compositions of 0.5% fuel (at equivalence ratios of 1.0, 2.0, and 0.5) and 2.5% fuel (at an equivalence ratio of 1.0). 3. Laminar burning velocities of outwardly propagating spherical CH{sub 3}OCHO/air flames have been determined for stoichiometries ranging from 0.8–1.6, at atmospheric pressure using a pressure-release-type high-pressure chamber. A detailed chemical kinetic model has been constructed, validated against, and used to interpret these experimental data. The kinetic model shows that methyl formate oxidation proceeds through concerted elimination reactions, principally forming methanol and carbon monoxide as well as through bimolecular hydrogen abstraction reactions. The relative importance of elimination versus abstraction was found to depend on the particular environment. In general, methyl formate is consumed exclusively through molecular decomposition in shock tube environments, while at flow reactor and freely propagating premixed flame conditions, there is significant competition between hydrogen abstraction and concerted elimination channels. It is suspected that in diffusion flame configurations the elimination channels contribute more significantly than in premixed environments.

  20. Fast Track Reservoir Modeling of Shale Formations in the Appalachian Basin.

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    in Lower Huron Shale (Big Sandy Gas Field), were used in this study; · Production was history matched models were developed. #12;4 Location of the Study Area Big Sandy Gas Field #12;5 Lower Huron Shale Matching - Forecasting #12;12 Top Down Reservoir Modeleing - Workflow · Decline Curve analysis · Type Curve

  1. Norphlet Formation (Upper Jurassic) sand erg: depositional model for northeastern De Soto salt basin, eastern Gulf of Mexico

    SciTech Connect (OSTI)

    Kemmer, D.A.; Reagan, R.L.

    1987-05-01T23:59:59.000Z

    Available well control, seismic reflection geometries, and seismic modeling suggest the interpretation of a Norphlet Formation (Upper Jurassic) sand erg in the northeastern De Soto salt basin. Ranging in thickness from less than 100 ft to nearly 1000 ft, the Norphlet erg encompasses an area of approximately 700 mi/sup 2/. Separated from the major gas accumulation in the Norphlet in the Mobile Bay area by the offshore extension of the Pensacola arch, the Norphlet erg appears to be oriented transverse to the axis of the De Soto salt basin. Seismic signatures for the Smackover carbonate, Norphlet sand, and Louann Salt intervals are investigated using synthetic seismograms generated from six wells in the eastern Gulf of Mexico. General characteristics about the reflection coefficients from the major units in the interval are noted. The reflection coefficient information and synthetic seismograms are used to interpret seismic data on a regional basis. Two-dimensional, vertical-incidence, ray-trace modeling of the seismic data is done to aid the interpretation on a detailed basis. Interpreted Norphlet sandstone thicknesses and Louann Salt structures are combined to support the Norphlet Formation sand erg hypothesis.

  2. Assessment of Energy Removal Impacts on Physical Systems: Hydrodynamic Model Domain Expansion and Refinement, and Online Dissemination of Model Results

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Khangaonkar, Tarang; Wang, Taiping

    2010-08-01T23:59:59.000Z

    In this report we describe the 1) the expansion of the PNNL hydrodynamic model domain to include the continental shelf along the coasts of Washington, Oregon, and Vancouver Island; and 2) the approach and progress in developing the online/Internet disseminations of model results and outreach efforts in support of the Puget Sound Operational Forecast System (PS-OPF). Submittal of this report completes the work on Task 2.1.2, Effects of Physical Systems, Subtask 2.1.2.1, Hydrodynamics, for fiscal year 2010 of the Environmental Effects of Marine and Hydrokinetic Energy project.

  3. Modeling crater formation in femtosecond-pulse laser damage from basic principles

    E-Print Network [OSTI]

    Mitchell, Robert A; Chowdhury, Enam A

    2015-01-01T23:59:59.000Z

    We present the first fundamental simulation method for the determination of crater morphology due to femtosecond-pulse laser damage. To this end we have adapted the particle-in-cell (PIC) method commonly used in plasma physics for use in the study of laser damage, and developed the first implementation of a pair-potential for PIC codes. We find that the PIC method is a complementary approach to modeling laser damage, bridging the gap between fully ab-initio molecular dynamics approaches and empirical models. We demonstrate our method by modeling a femtosecond-pulse laser incident on a flat copper slab, for a range of intensities.

  4. NUMERICAL MODELING FOR THE FORMATION MECHANISM OF 3D TOPOGRAPHY ON MICROBIAL MAT SURFACES

    E-Print Network [OSTI]

    Patel, Harsh Jay

    2013-09-27T23:59:59.000Z

    , an innovative modeling approach was employed that focuses on the interface growth of the microbial mat surfaces using a combined stochastic and deterministic approach. A range of different initial conditions were simulated to evaluate the 3D topography evolution...

  5. Modeling Biogeochemistry and Flow within Heterogeneous Formations in Variably-Saturated Media

    E-Print Network [OSTI]

    Arora, Bhavna

    2012-10-19T23:59:59.000Z

    to accurately model preferential flow and tracer transport. This research is crucial to agricultural systems where soil and crop management practices modify soil structure and alter macropore densities. The comparison between deterministic and stochastic...

  6. Isolating Triggered Star Formation

    SciTech Connect (OSTI)

    Barton, Elizabeth J.; Arnold, Jacob A.; /UC, Irvine; Zentner, Andrew R.; /KICP, Chicago /Chicago U., EFI; Bullock, James S.; /UC, Irvine; Wechsler, Risa H.; /KIPAC, Menlo

    2007-09-12T23:59:59.000Z

    Galaxy pairs provide a potentially powerful means of studying triggered star formation from galaxy interactions. We use a large cosmological N-body simulation coupled with a well-tested semi-analytic substructure model to demonstrate that the majority of galaxies in close pairs reside within cluster or group-size halos and therefore represent a biased population, poorly suited for direct comparison to 'field' galaxies. Thus, the frequent observation that some types of galaxies in pairs have redder colors than 'field' galaxies is primarily a selection effect. We use our simulations to devise a means to select galaxy pairs that are isolated in their dark matter halos with respect to other massive subhalos (N= 2 halos) and to select a control sample of isolated galaxies (N= 1 halos) for comparison. We then apply these selection criteria to a volume-limited subset of the 2dF Galaxy Redshift Survey with M{sub B,j} {le} -19 and obtain the first clean measure of the typical fraction of galaxies affected by triggered star formation and the average elevation in the star formation rate. We find that 24% (30.5 %) of these L* and sub-L* galaxies in isolated 50 (30) h{sup -1} kpc pairs exhibit star formation that is boosted by a factor of {approx}> 5 above their average past value, while only 10% of isolated galaxies in the control sample show this level of enhancement. Thus, 14% (20 %) of the galaxies in these close pairs show clear triggered star formation. Our orbit models suggest that 12% (16%) of 50 (30) h{sup -1} kpc close pairs that are isolated according to our definition have had a close ({le} 30 h{sup -1} kpc) pass within the last Gyr. Thus, the data are broadly consistent with a scenario in which most or all close passes of isolated pairs result in triggered star formation. The isolation criteria we develop provide a means to constrain star formation and feedback prescriptions in hydrodynamic simulations and a very general method of understanding the importance of triggered star formation in a cosmological context.

  7. A comparative study of analytical models to estimate the LNAPL mound formation

    E-Print Network [OSTI]

    Ahmed, Ashfaq

    1994-01-01T23:59:59.000Z

    is constant for the duration of the spreading. Secondly, the model does not consider the organic phase which is held up as residual saturation in the unsaturated zone above the water table. Holzer [1976] used the saltwater/freshwater analogy to study... hydrocarbon. Reible et al. , [1991] developed a model to describe the one-dimensional infiltra- tion of a NAPL through an unsaturated zone initially at residual water saturation. tion of a NAPL through an unsaturated zone initially at residual water...

  8. A comparative study of analytical models to estimate the LNAPL mound formation 

    E-Print Network [OSTI]

    Ahmed, Ashfaq

    1994-01-01T23:59:59.000Z

    developed. Even though these models are based on various as- sumptions, they are useful as tools in evaluating the spreading of the free oil phase during sn oil spill. The spreading depends on many factors, such as leak volume, type of petroleum product..., hydrogeological conditions, and hydraulic properties of the medium as well as the oil. Among the various modeling approaches to predict spill migration, the sharp interface approach has been widely examined due to its simplicity for homogeneous media...

  9. Solar Deployment System (SolarDS) Model: Documentation and Sample Results

    SciTech Connect (OSTI)

    Denholm, P.; Drury, E.; Margolis, R.

    2009-09-01T23:59:59.000Z

    The Solar Deployment System (SolarDS) model is a bottom-up, market penetration model that simulates the potential adoption of photovoltaics (PV) on residential and commercial rooftops in the continental United States through 2030. NREL developed SolarDS to examine the market competitiveness of PV based on regional solar resources, capital costs, electricity prices, utility rate structures, and federal and local incentives. The model uses the projected financial performance of PV systems to simulate PV adoption for building types and regions then aggregates adoption to state and national levels. The main components of SolarDS include a PV performance simulator, a PV annual revenue calculator, a PV financial performance calculator, a PV market share calculator, and a regional aggregator. The model simulates a variety of installed PV capacity for a range of user-specified input parameters. PV market penetration levels from 15 to 193 GW by 2030 were simulated in preliminary model runs. SolarDS results are primarily driven by three model assumptions: (1) future PV cost reductions, (2) the maximum PV market share assumed for systems with given financial performance, and (3) PV financing parameters and policy-driven assumptions, such as the possible future cost of carbon emissions.

  10. The new model of chemical evolution of r-process elements based on the hierarchical galaxy formation. I. Ba and Eu

    SciTech Connect (OSTI)

    Komiya, Yutaka; Suda, Takuma [National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan); Yamada, Shimako [Department of Cosmoscience, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Fujimoto, Masayuki Y. [Nuclear reaction data center, Graduate School of Science, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan)

    2014-03-10T23:59:59.000Z

    We investigate the chemical enrichment of r-process elements in the early evolutionary stages of the Milky Way halo within the framework of hierarchical galaxy formation using a semi-analytic merger tree. In this paper, we focus on heavy r-process elements, Ba and Eu, of extremely metal-poor (EMP) stars and give constraints on their astronomical sites. Our models take into account changes of the surface abundances of EMP stars by the accretion of interstellar medium (ISM). We also consider metal-enrichment of intergalactic medium by galactic winds and the resultant pre-enrichment of proto-galaxies. The trend and scatter of the observed r-process abundances are well reproduced by our hierarchical model with ?10% of core-collapse supernovae in low-mass end (?10 M {sub ?}) as a dominant r-process source and the star formation efficiency of ?10{sup –10} yr{sup –1}. For neutron star mergers as an r-process source, their coalescence timescale has to be ?10{sup 7} yr, and the event rates ?100 times larger than currently observed in the Galaxy. We find that the accretion of ISM is a dominant source of r-process elements for stars with [Ba/H] < –3.5. In this model, a majority of stars at [Fe/H] < –3 are formed without r-process elements, but their surfaces are polluted by the ISM accretion. The pre-enrichment affects ?4% of proto-galaxies, and yet, is surpassed by the ISM accretion in the surface of EMP stars.

  11. Results on the search for the standard model Higgs boson at CMS

    SciTech Connect (OSTI)

    Fabozzi, Francesco [INFN Sezione di Napoli, Complesso Univ. di Monte S. Angelo Via Cintia - 80126 Napoli (Italy) and Universita della Basilicata, Viale dell'Ateneo Lucano 10 - 85100 Potenza (Italy); Collaboration: CMS Collaboration

    2012-10-23T23:59:59.000Z

    A summary of the results from searches for the Standard Model Higgs Boson in the CMS experiment at LHC with data collected from proton-proton collisions at {radical}(s) = 7TeV is presented. The Higgs boson is searched in a multiplicity of decay channels using data samples corresponding to integrated luminosities in the range 4.6 - 4.8 fb{sup -1}. The investigated mass range is 110 - 600 GeV. Results are reported for each channel as well as for their combination.

  12. A model for gyrotactic pattern formation of motile micro-organisms in turbulence

    E-Print Network [OSTI]

    Gustavsson, K; Jonsson, P R; Mehlig, B

    2015-01-01T23:59:59.000Z

    Recent studies show that the dynamics of motile organisms subject to gravitational torques in turbulence gives rise to patchiness. Spherical motile organisms gather in down-welling regions of the turbulent flow. We determine how shape affects preferential sampling and small-scale spatial clustering (determining local encounter rates) by analysing a statistical model in two and three spatial dimensions. By recursively refining approximations for the paths the organisms take through the flow we determine analytically how preferential sampling and small-scale clustering in the model depend upon the dimensionless parameters of the problem. We show that singularities ("caustics") occur in the dynamics and discuss how these singularities affect spatial patterns.

  13. Fluctuation level bursts in a model of internal transport barrier formation D. Lopez-Bruna, D. E. Newman, and B. A. Carreras

    E-Print Network [OSTI]

    Newman, David

    features of ITB models the phase transition character with a power threshold, barrier front propagation radial electric field.10,11 As happens with the edge transport barriers, the system reacts to the extraFluctuation level bursts in a model of internal transport barrier formation D. Lo´pez-Bruna, D. E

  14. Modeling particle formation during low-pressure silane oxidation: Detailed chemical kinetics and aerosol dynamics

    E-Print Network [OSTI]

    Zachariah, Michael R.

    that the generation of SiOHx species from fast gas- phase reactions can significantly degrade film quality. Based conservation equations and a moment-type aerosol dynamics model were formulated for a batch reactor undergoing to impurity diffusion.1 During LPCVD film deposition rates are limited by the gas-phase nucleation

  15. A trainable trajectory formation model TD-HMM parameterized for the LIPS 2008 challenge

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    agents ­ virtual characters as well as anthropoid robots ­ should be able to talk with their human. Index Terms: facial animation audiovisual speech synthesis, HMM 1. Introduction Embodied conversational model of the robot). Human interlocutors are very sensitive to discrepancies between the visible

  16. A multiple layer numerical model of the formation of the low-level jet

    E-Print Network [OSTI]

    Shen, Tsu-Cheng

    1980-01-01T23:59:59.000Z

    310 320 e(kj Fig. 3. The initial vertical distribution of potential tempera- ture in the model . Table 3. The vertical distribution of the variables used for setting the initial conditions. LEVEL k (m s ) kh(m s ) u(ms ) v(ms ) w(ms ) e (k) 00 p...

  17. Squeezout phenomena and boundary layer formation of a model ionic liquid under confinement and charging

    E-Print Network [OSTI]

    R. Capozza; A. Vanossi; A. Benassi; E. Tosatti

    2014-12-22T23:59:59.000Z

    Electrical charging of parallel plates confining a model ionic liquid down to nanoscale distances yields a variety of charge-induced changes in the structural features of the confined film. That includes even-odd switching of the structural layering and charging-induced solidification and melting, with important changes of local ordering between and within layers, and of squeezout behavior. By means of molecular dynamics simulations, we explore this variety of phenomena in the simplest charged Lennard-Jones coarse-grained model including or excluding the effect a neutral tail giving an anisotropic shape to one of the model ions. Using these models and open conditions permitting the flow of ions in and out of the interplate gap, we simulate the liquid squeezout to obtain the distance dependent structure and forces between the plates during their adiabatic appraoch under load. Simulations at fixed applied force illustrate an effective electrical pumping of the ionic liquid, from a thick nearly solid film that withstands the interplate pressure for high plate charge to complete squeezout following melting near zero charge. Effective enthalpy curves obtained by integration of interplate forces versus distance show the local minima that correspond to layering, and predict the switching between one minimum and another under squeezing and charging.

  18. Phase-field models in interfacial pattern formation out of equilibrium

    E-Print Network [OSTI]

    R. Gonzalez-Cinca; R. Folch; R. Benitez; L. Ramirez-Piscina; J. Casademunt; A. Hernandez-Machado

    2003-05-03T23:59:59.000Z

    The phase-field method is reviewed from the general perspective of converting a free boundary problem into a set of coupled partial differential equations. Its main advantage is that it avoids front tracking by using phase fields to locate the fronts. These fields interpolate between different constant values in each bulk phase through diffuse interfaces of finite thickness. In solidification, the phase fields can be understood as order parameters, and the model is often derived to dynamically minimise a free energy functional. However, this is not a necessary requirement, and both derivations involving a free energy (basic solidification model) and not (first viscous fingering model) are worked out. In any case, the model is required to reproduce the original free boundary problem in the limit of vanishing interface thickness. This limit and its higher order corrections, important to make quantitative contact between simulations and experiments, are discussed for both examples. Applications to fluctuations in solidification, the growth of liquid crystal mesophases, and viscous fingering in Hele-Shaw cells are presented.

  19. Mg line formation in late-type stellar atmospheres: I. The model atom

    E-Print Network [OSTI]

    Osorio, Y; Lind, K; Belyaev, A K; Spielfiedel, A; Guitou, M; Feautrier, N

    2015-01-01T23:59:59.000Z

    Mg is often traced in late-type stars using lines of neutral magnesium, which is expected to be subject to departures from LTE. The astrophysical importance of Mg as well as its relative simplicity from an atomic physics point of view, makes it a prime target and test bed for detailed ab initio non-LTE modelling in stellar atmospheres. For the low-lying states of Mg i, electron collision data were calculated using the R-matrix method. Calculations for collisional broadening by neutral hydrogen were also performed where data were missing. These calculations, together with data from the literature, were used to build a model atom. First, the modelling was tested by comparisons with observed spectra of benchmark stars with well-known parameters. Second, the spectral line behaviour and uncertainties were explored by extensive experiments in which sets of collisional data were changed or removed. The modelled spectra agree well with observed spectra. The line-to-line scatter in the derived abundances shows improve...

  20. Discrete Element Modeling Results of Proppant Rearrangement in the Cooke Conductivity Cell

    SciTech Connect (OSTI)

    Earl Mattson; Hai Huang; Michael Conway; Lisa O'Connell

    2014-02-01T23:59:59.000Z

    The study of propped fracture conductivity began in earnest with the development of the Cooke cell which later became part of the initial API standard. Subsequent developments included a patented multicell design to conduct 4 tests in a press at the same time. Other modifications have been used by various investigators. Recent studies by the Stim-Lab proppant consortium have indicated that the flow field across a Cooke proppant conductivity testing cell may not be uniform as initially believed which resulted is significantly different conductivity results. Post test analysis of low temperature metal alloy injections at the termination of proppant testing prior to the release of the applied stress suggest that higher flow is to be expected along the sides and top of the proppant pack than compared to the middle of the pack. To evaluate these experimental findings, a physics-based two-dimensional (2-D) discrete element model (DEM) was developed and applied to simulate proppant rearrangement during stress loading in the Cooke conductivity cell and the resulting porosity field. Analysis of these simulations are critical to understanding the impact of modification to the testing cell as well as understanding key proppant conductivity issues such as how these effects are manifested in proppant concentration testing results. The 2-D DEM model was constructed to represent a realistic cross section of the Cooke cell with a distribution of four material properties, three that represented the Cooke cell (steel, sandstone,square rings), and one representing the proppant. In principle, Cooke cell materials can be approximated as assemblies of independent discrete elements (particles) of various sizes and material properties that interact via cohesive interactions, repulsive forces, and frictional forces. The macroscopic behavior can then be modeled as the collective behavior of many interacting discrete elements. This DEM model is particularly suitable for modeling proppant mechanical interactions subjected to an applied stress, where the experimental cell is represented as a cohesive body composed of a large number of discrete elements, and proppants can be modeled as the individual discrete particles with various sizes (following the proppant size distribution-density function used in the test) that exhibit no cohesive strength between the particles. Initial 2-D DEM modeling results suggest that proppant rearrangement and non-uniform stress distribution across the proppant pack results in significant non-uniform porosity distribution across the Cooke cell. Larger porosities develop along the edge of the proppant pack beneath the square ring seal and would result in a disproportionate higher flow field along these edges as compared to the middle of the proppant pack. These results suggest that reported conductivity values determined by the Cooke cell may be biased to overestimate the actual conductivity of the proppant at high stresses and that modifications to the standard Cooke cell will affect the magnitude of this bias.

  1. Cognitive environment simulation: An artificial intelligence system for human performance assessment: Modeling human intention formation: (Technical report, May 1986-June 1987)

    SciTech Connect (OSTI)

    Woods, D.D.; Roth, E.M.; Pople, H. Jr.

    1987-11-01T23:59:59.000Z

    This report documents the results of Phase II of a three phase research program to develop and validate improved methods to model the cognitive behavior of nuclear power plant (NPP) personnel. In Phase II a dynamic simulation capability for modeling how people form intentions to act in NPP emergency situations was developed based on techniques from artificial intelligence. This modeling tool, Cognitive Environment Simulation or CES, simulates the cognitive processes that determine situation assessment and intention formation. It can be used to investigate analytically what situations and factors lead to intention failures, what actions follow from intention failures (e.g., errors of omission, errors of commission, common mode errors), the ability to recover from errors or additional machine failures, and the effects of changes in the NPP person-machine system. The Cognitive Reliability Assessment Technique (or CREATE) was also developed in Phase II to specify how CES can be used to enhance the measurement of the human contribution to risk in probabilistic risk assessment (PRA) studies. 43 refs., 20 figs., 1 tab.

  2. Transformation from spots to waves in a model of actin pattern formation

    E-Print Network [OSTI]

    Stephen Whitelam; Till Bretschneider; Nigel J. Burroughs

    2009-05-18T23:59:59.000Z

    Actin networks in certain single-celled organisms exhibit a complex pattern-forming dynamics that starts with the appearance of static spots of actin on the cell cortex. Spots soon become mobile, executing persistent random walks, and eventually give rise to traveling waves of actin. Here we describe a possible physical mechanism for this distinctive set of dynamic transformations, by equipping an excitable reaction-diffusion model with a field describing the spatial orientation of its chief constituent (which we consider to be actin). The interplay of anisotropic actin growth and spatial inhibition drives a transformation at fixed parameter values from static spots to moving spots to waves.

  3. Energetic neutral atom imaging with the Polar CEPPAD/IPS instrument: Initial forward modeling results

    SciTech Connect (OSTI)

    Henderson, M.G.; Reeves, G.D.; Moore, K.R. [Los Alamos National Lab., NM (United States); Spence, H.E.; Jorgensen, A.M. [Boston Univ., MA (United States). Center for Space Physics; Fennell, J.F.; Blake, J.B. [Aerospace Corp., Los Angeles, CA (United States); Roelof, E.C. [Johns Hopkins Univ., Laurel, MD (United States). Applied Physics Lab.

    1997-12-31T23:59:59.000Z

    Although the primary function of the CEP-PAD/IPS instrument on Polar is the measurement of energetic ions in-situ, it has also proven to be a very capable Energetic neutral Atom (ENA) imager. Raw ENA images are currently being constructed on a routine basis with a temporal resolution of minutes during both active and quiet times. However, while analyses of these images by themselves provide much information on the spatial distribution and dynamics of the energetic ion population in the ring current, detailed modeling is required to extract the actual ion distributions. In this paper, the authors present the initial results of forward modeling an IPS ENA image obtained during a small geo-magnetic storm on June 9, 1997. The equatorial ion distribution inferred with this technique reproduces the expected large noon/midnight and dawn/dusk asymmetries. The limitations of the model are discussed and a number of modifications to the basic forward modeling technique are proposed which should significantly improve its performance in future studies.

  4. A Comparison of Shell Model Results for Some properties of the Even-Even Ge Isotopes

    E-Print Network [OSTI]

    S. J. Q. Robinson; L. Zamick; Y. Y. Sharon

    2010-07-13T23:59:59.000Z

    In this work we examine two recent effective shell model interactions, JUN45 and JJ4B, that have been proposed for use in the $f_{5/2},p_{3/2}, p_{1/2}, g_{9/2}$ model space for both protons and neutrons. We calculate a number of quantities that did not enter into the fits undertaken to fix the parameters of both interactions. In particular we consider static quadrupole moments (Q's) of excited states of the even-even $^{70-76}$Ge isotopes, as well as the B(E2) values in these nuclei. (We have previously studied $^{70}$Zn isotopes using JJ4B.) Some striking disagreements between the JUN45 prediction and the experimental results had already been noted for the quadrupole moments of the $2_1^+$ states of these nuclei. We investigate whether these discrepancies also occur for the JJ4B interaction. Subsequently, we also apply both interactions to calculate the Q's of some more highly excited states and compare the two sets of predictions regarding the nature of the nuclear states under consideration. In order to gain insight into these more complex large-scale shell-model calculations, we examine the corresponding and much simpler single-j shell model calculations in the $g_{9/2}$ neutron shell.

  5. The solar photospheric abundance of europium. Results from CO5BOLD 3-D hydrodynamical model atmospheres

    E-Print Network [OSTI]

    A. Mucciarelli; E. Caffau; B. Freytag; H. -G. Ludwig; P. Bonifacio

    2008-03-06T23:59:59.000Z

    Context. Europium is an almost pure r-process element, which may be useful as a reference in nucleocosmochronology. Aims. To determine the photospheric solar abundance using CO5BOLD 3-D hydrodynamical model atmospheres. Methods. Disc-centre and integrated-flux observed solar spectra are used. The europium abundance is derived from the equivalent width measurements. As a reference 1D model atmospheres have been used, in addition. Results. The europium photospheric solar abundance is 0.52 +- 0.02 in agreement with previous determinations. We also determine the photospheric isotopic fraction of Eu(151) to be 49 % +- 2.3 % from the intensity spectra and 50% +-2.3 from the flux spectra. This compares well to the the meteoritic isotopic fraction 47.8%. We explore the 3D corrections also for dwarfs and sub-giants in the temperature range ~5000 K to ~6500 K and solar and 1/10--solar metallicities and find them to be negligible for all the models investigated. Conclusions. Our photospheric Eu abundance is in good agreement with previous determinations based on 1D models. This is in line with our conclusion that 3D effects for this element are negligible in the case of the Sun.

  6. Image formation modeling in cryo-electron microscopy Milos Vulovic a,b

    E-Print Network [OSTI]

    Rieger, Bernd

    dam- age which limits the integrated electron flux that can be used, resulting in a poor signal's scattering properties, microscope optics, and detector response. The specimen interaction potential contrast, changes due to the integrated electron flux, thickness, inelastic scattering, detective quantum

  7. An empirical behavioral model of price formation Szabolcs Mike1, 2

    E-Print Network [OSTI]

    of freedom, centered on the best quoted price. This result is surprising because it implies that trading with the mainstream paradigm, but it fails to provide a positive alternative with quantitative predictive power2 to the simple actions of placing and canceling trading orders. The data that we study here contains hundreds

  8. Kinetic modeling of petroleum formation in the Maracaibo Basin: Final report, Annex 12

    SciTech Connect (OSTI)

    Burnham, A.K.; Braun, R.L.; Sweeney, J.J.; Reynolds, J.G. [Lawrence Livermore National Lab., CA (United States); Vallejos, C.; Talukdar, S. [INTEVEP, Filial de Petroleos de Venezuela, SA, Caracas (Venezuela)

    1992-07-01T23:59:59.000Z

    The purpose of this project is to develop and test improved kinetic models of petroleum generation and cracking, pore pressure buildup, and fluid expulsion. The work was performed jointly between Lawrence Livermore National Laboratory and Research Organization of the Venezuelan National Petroleum Company under Annex 12 of an agreement between DOE and the Venezuelan Ministry of Energy and Mines. Laboratory experiments were conducted at both LLNL and INTEVEP to obtain the reaction rate and product composition information needed to develop chemical kinetic models. Experiments at INTEVEP included hydrous pyrolysis and characterization of oils by gas and liquid chromatography. Experiments at LLNL included programmed pyrolysis in open and self-purging reactors, sometimes including on-line gas analysis by tandem mass spectrometry, and characterization of oils by gas chromatography and nuclear magnetic resonance. The PMOD code was used to develop a detailed pyrolysis mechanism from the extensive laboratory data. This mechanism is able to predict yield of bitumen, oil, and gas as a function of time and temperature for such diverse laboratory conditions as hydrous pyrolysis and rapid, programmed, open pyrolysis. PMOD calculations were compared to geologic observations for 22 wells in the Maracaibo basin. When permeability parameters are chosen to match calculated pore pressures with measured present day values, the PMOD calculations indicate that organic maturation reactions contribute a significant fraction of the overpressure during oil generation and early oil cracking. Calculations agreed with observed geochemical maturity parameters of the source rock. 37 refs., 64 figs., 20 tabs.

  9. Modelling Viscoelastic Behaviour of Polymer by A Mixed Velocity, Displacement Formulation - Numerical and Experimental Results

    SciTech Connect (OSTI)

    Pham, VT.; Silva, L.; Digonnet, H.; Combeaud, C.; Billon, N.; Coupez, T. [Centre for Material Forming (CEMEF), MINES ParisTech, Rue Claude Daunesse, Sophia Antipolis cedex (France)

    2011-05-04T23:59:59.000Z

    The objective of this work is to model the viscoelastic behaviour of polymer from the solid state to the liquid state. With this objective, we perform experimental tensile tests and compare with simulation results. The chosen polymer is a PMMA whose behaviour depends on its temperature. The computation simulation is based on Navier-Stokes equations where we propose a mixed finite element method with an interpolation P1+/P1 using displacement (or velocity) and pressure as principal variables. The implemented technique uses a mesh composed of triangles (2D) or tetrahedra (3D). The goal of this approach is to model the viscoelastic behaviour of polymers through a fluid-structure coupling technique with a multiphase approach.

  10. The development of a model of Alpha helix formation for transmembrane peptides

    E-Print Network [OSTI]

    Funk, Geoffrey Alexander

    2013-02-22T23:59:59.000Z

    were synthesized upon Rink resin, activation of the amino acid residues occurs using N-methylpyrrolidone (NMP) and I-hydroxybenzotriazole (HOBt), and coupling uses Fmoc-protected amino acids. The notable difference between Fmoc and FastMoc chemistry... involves the use of 2-(IH-benzotriazol-l-yl)-1, 1, 3, 3- tetramethyluronium hexafluorophosphate (HBTU) in the HOBt/NMP activation, as well as in situ activation by diisopropylethylamine (DIEA), in FastMoc chemistry, resulting in higher efficiency...

  11. A simple model for nanofiber formation by rotary jet-spinning

    E-Print Network [OSTI]

    Paula Mellado; Holly A. McIlwee; Mohammad R. Badrossamay; Josue A. Goss; L. Mahadevan; K Parker

    2012-02-12T23:59:59.000Z

    Nanofibers are microstructured materials that span a broad range of applications from tissue engineering scaffolds to polymer transistors. An efficient method of nanofiber production is Rotary Jet-Spinning (RJS), consisting of a perforated reservoir rotating at high speeds along its axis of symmetry, which propels a liquid, polymeric jet out of the reservoir orifice. These jets undergo stretching and solidify forming nanoscale fibers. We report a minimal scaling framework complemented by a semi-analytic and numerical approach to characterize the regimes of nanofiber production using RJS. Our theoretical model is validated for the fiber radius as a function of experimentally tunable parameters. We summarize our findings in a phase diagram for the design space of continuous nanofibers as a function of process parameters, in good agreement with experiments and with natural implications for the production rates as well as in the morphological quality of fibers.

  12. Geomagnetic effects modelling for the PJM interconnection system. Part 2; Geomagnetically induced current study results

    SciTech Connect (OSTI)

    Prabhakara, F.S.; Hannett, L.N.; Ringlee, R.J. (Power Technologies, Inc., Schenectady, NY (United States)); Ponder, J.Z. (PJM Interconnection, Norristown, PA (US))

    1992-05-01T23:59:59.000Z

    The development of a computer program for calculation of geomagnetically induced current (GIC) and a GIC power system model for the Pennsylvania-New Jersey-Maryland Interconnection is described in this paper. Results of GIC for three different ionospheric source configurations are shown. A new method is presented for estimating GIC in unmetered parts of the system based on a few measurements and precalculated geomagnetic disturbance conditions. The use of an interactive, menu driven GIC program to study mitigation concepts including the effects of line outages, line series capacitors, transformer neutral blocking resistors and transformer neutral blocking capacitors is also presented.

  13. Global environmental effects of impact-generated aerosols: Results from a general circulation model: Revision 1

    SciTech Connect (OSTI)

    Covey, C.; Ghan, S.J.; Walton, J.J.; Weissman, P.R.

    1989-06-01T23:59:59.000Z

    Interception of sunlight by the high altitude worldwide dust cloud generated by impact of a large asteroid or comet would lead to substantial land surface cooling, according to our three-dimensional atmospheric general circulation model (GCM). This result is qualitatively similar to conclusions drawn from an earlier study that employed a one-dimensional atmospheric model, but in the GCM simulation the heat capacity of the oceans substantially mitigates land surface cooling, an effect that one-dimensional models cannot quantify. On the other hand, the low heat capacity of the GCM's land surface allows temperatures to drop more rapidly in the initial stage of cooling than in the one-dimensional model study. These two differences between three-dimensional and one-dimensional model simulations were noted previously in studies of ''nuclear winter; '' GCM-simulated climatic changes in the Alvarez-inspired scenario of ''asteroid/comet winter,'' however, are more severe than in ''nuclear winter'' because the assumed aerosol amount is large enough to intercept all sunlight falling on earth. Impacts of smaller objects -- which would occur much more frequently than the Cretaceous/Tertiary event deduced by Alvarez and coworkers -- could also lead to dramatic, though less severe, climatic changes, according to our GCM. Our conclusion is that it is difficult to imagine an asteroid or comet impact leading to anything approaching complete global freezing, but quite reasonable to assume that impacts at the Alvarez level, or even smaller, dramatically alter the climate in at least a ''patchy'' sense. 30 refs., 4 figs., 1 tab.

  14. The VMC Survey - XIV. First results on the look-back time star-formation rate tomography of the Small Magellanic Cloud

    E-Print Network [OSTI]

    Rubele, Stefano; Kerber, Leandro; Cioni, Maria-Rosa L; Piatti, Andres E; Zaggia, Simone; Bekki, Kenji; Bressan, Alessandro; Clementini, Gisella; de Grijs, Richard; Emerson, Jim P; Groenewegen, Martin A T; Ivanov, Valentin D; Marconi, Marcella; Marigo, Paola; Moretti, Maria-Ida; Ripepi, Vincenzo; Subramanian, Smitha; Tatton, Benjamin L; van Loon, Jacco Th

    2015-01-01T23:59:59.000Z

    We analyse deep images from the VISTA survey of the Magellanic Clouds in the YJKs filters, covering 14 sqrdeg (10 tiles), split into 120 subregions, and comprising the main body and Wing of the Small Magellanic Cloud (SMC). We apply a colour--magnitude diagram reconstruction method that returns their best-fitting star formation rate SFR(t), age-metallicity relation (AMR), distance and mean reddening, together with 68% confidence intervals. The distance data can be approximated by a plane tilted in the East-West direction with a mean inclination of 39 deg, although deviations of up to 3 kpc suggest a distorted and warped disk. After assigning to every observed star a probability of belonging to a given age-metallicity interval, we build high-resolution population maps. These dramatically reveal the flocculent nature of the young star-forming regions and the nearly smooth features traced by older stellar generations. They document the formation of the SMC Wing at ages <0.2 Gyr and the peak of star formation ...

  15. Model for deposition of bedded halite in a shallow shelf setting, San Andres Formation, Palo Duro Basin, Texas panhandle

    SciTech Connect (OSTI)

    Hovorka, S.D.

    1985-01-01T23:59:59.000Z

    Existing depositional models for evaporites do not adequately describe facies relationships, halite fabrics, and trace element geochemistry of halite from the Permian San Andres Formation. Interbedding of anhydritic halite and mudstone with disrupted bedding records alternation between marine-dominated brine pool and subaerial environments. Chevron structures and hopper crystal cumulates in the halite indicate subaqueous deposition. Abundant anhydrite partings within halite, which thicken and become interbedded with marine shelf carbonates to the south, demonstrate the facies equivalence and physical connection of evaporite and marine environments. Maintenance of marine character in trace element profiles through halite sequences documents the episodic influx of marine water. Haloturbated structure in mudstone interbeds within the halite is produced by displacive growth of halite within mudstone and dissolution and collapse of this halite as ground-water chemistry fluctuates in response to conditions of alternating desiccation and wetting. Karst features cutting the halite also imply subaerial exposure. Mapping of the fine-scale sedimentary structures, geochemical signature, and insoluble component mineralogy of halite sequences indicates that the brine pool environment extended over areas in excess of 100 km/sup 2/. Sabkha, salina, playa, and deep water basin models of halite-precipitating environments do not satisfactorily describe the shallow marine shelf depositional environment of the San Andres halite.

  16. The solar photospheric abundance of europium. Results from CO5BOLD 3-D hydrodynamical model atmospheres

    E-Print Network [OSTI]

    Mucciarelli, A; Freytag, B; Ludwig, H -G; Bonifacio, P

    2008-01-01T23:59:59.000Z

    Context. Europium is an almost pure r-process element, which may be useful as a reference in nucleocosmochronology. Aims. To determine the photospheric solar abundance using CO5BOLD 3-D hydrodynamical model atmospheres. Methods. Disc-centre and integrated-flux observed solar spectra are used. The europium abundance is derived from the equivalent width measurements. As a reference 1D model atmospheres have been used, in addition. Results. The europium photospheric solar abundance is 0.52 +- 0.02 in agreement with previous determinations. We also determine the photospheric isotopic fraction of Eu(151) to be 49 % +- 2.3 % from the intensity spectra and 50% +-2.3 from the flux spectra. This compares well to the the meteoritic isotopic fraction 47.8%. We explore the 3D corrections also for dwarfs and sub-giants in the temperature range ~5000 K to ~6500 K and solar and 1/10--solar metallicities and find them to be negligible for all the models investigated. Conclusions. Our photospheric Eu abundance is in good agre...

  17. Hawaii Solar Integration Study: Solar Modeling Developments and Study Results; Preprint

    SciTech Connect (OSTI)

    Orwig, K.; Corbus, D.; Piwko, R.; Schuerger, M.; Matsuura, M.; Roose, L.

    2012-12-01T23:59:59.000Z

    The Hawaii Solar Integration Study (HSIS) is a follow-up to the Oahu Wind Integration and Transmission Study completed in 2010. HSIS focuses on the impacts of higher penetrations of solar energy on the electrical grid and on other generation. HSIS goes beyond the island of Oahu and investigates Maui as well. The study examines reserve strategies, impacts on thermal unit commitment and dispatch, utilization of energy storage, renewable energy curtailment, and other aspects of grid reliability and operation. For the study, high-frequency (2-second) solar power profiles were generated using a new combined Numerical Weather Prediction model/ stochastic-kinematic cloud model approach, which represents the 'sharp-edge' effects of clouds passing over solar facilities. As part of the validation process, the solar data was evaluated using a variety of analysis techniques including wavelets, power spectral densities, ramp distributions, extreme values, and cross correlations. This paper provides an overview of the study objectives, results of the solar profile validation, and study results.

  18. New Model to Predict Formation Damage due to Sulfur Deposition in Sour M.A. Mahmoud and A.A. Al-Majed, KFUPM, all SPE

    E-Print Network [OSTI]

    Al-Majed, Abdulaziz Abdullah

    in the reservoir will help in better management of sour gas reservoirs with potential sulfur deposition problems as a dissolved species in virtually all deep sour gas reservoirs. Sulfur precipitation is induced by a reductionSPE 149535 New Model to Predict Formation Damage due to Sulfur Deposition in Sour Gas Wells M

  19. Preprint version -final, definitive version available at http://ijr.sagepub.com/ accepted for IJRR, Sep. 2012 Modeling and Control of UAV Bearing-Formations

    E-Print Network [OSTI]

    , Sep. 2012 Modeling and Control of UAV Bearing-Formations with Bilateral High-Level Steering Antonio Abstract--In this paper we address the problem of controlling the motion of a group of UAVs bound to keep. The controller still leaves the possibility to impose group motions tangent to the current bearing

  20. Gravity modeling of the Song Hong basin: an insight into its crustal structure and implication for the formation of the basin

    E-Print Network [OSTI]

    Nguyen, Vu Giang

    1996-01-01T23:59:59.000Z

    3-D gravity inversion and rift stretching models are used in the Song Hong basin to determine the general configuration of the upper mantle and the mechanism for its formation in the region. The basin approximately 200 km wide by 600 km in length...

  1. Mathematical model of stress formation during vacuum resin infusion I.B. Sevostianov, V.E. Verijenko*, C.J. von Klemperer, B. Chevallereau1

    E-Print Network [OSTI]

    Sevostianov, Igor

    Mathematical model of stress formation during vacuum resin infusion process I.B. Sevostianov, V manufacturing technology based on vacuum infusion which is also known as resin film infusion technology to be infused by the vacuum to completely wet-out the reinforcements and eliminate air voids in the laminate

  2. Using Pre-Modeled Scenarios to Estimate Groundwater VOC Concentrations Resulting from Vadose Zone Sources

    SciTech Connect (OSTI)

    Oostrom, Martinus; Truex, Michael J.; Rice, Amy K.; Johnson, Christian D.; Carroll, Kenneth C.; Becker, Dave; Simon, Michelle A.

    2014-04-28T23:59:59.000Z

    Soil vapor extraction (SVE) is a prevalent remediation approach for volatile contaminants in the vadose zone. To support selection of an appropriate endpoint for the SVE remedy, an evaluation is needed to determine whether vadose zone contamination has been diminished sufficiently to protect groundwater. When vapor-phase transport is an important component of the overall contaminant fate and transport from a vadose zone source, the contaminant concentration expected in groundwater is controlled by a limited set of parameters, including specific site dimensions, vadose zone properties, and source characteristics. An approach was developed for estimating the contaminant concentration in groundwater resulting from a contaminant source in the vadose zone based on pre-modeling contaminant transport for a matrix of parameter value combinations covering a range of potential site conditions. An interpolation and scaling process are then applied to estimate groundwater impact for site-specific conditions.

  3. The Role of Asia in Mitigating Climate Change: Results from the Asia Modeling Exercise

    SciTech Connect (OSTI)

    Calvin, Katherine V.; Clarke, Leon E.; Krey, Volker; Blanford, Geoffrey J.; Jiang, Kejun; Kainuma, M.; Kriegler, Elmar; Luderer, Gunnar; Shukla, Priyadarshi R.

    2012-12-01T23:59:59.000Z

    In 2010, Asia accounted for 60% of global population, 39% of Gross World Product, 44% of global energy consumption and nearly half of the world’s energy system CO2 emissions. Thus, Asia is an important region to consider in any discussion of climate change or climate change mitigation. This paper explores the role of Asia in mitigating climate change, by comparing the results of 23 energy-economy and integrated assessment models. We focus our analysis on seven key areas: base year data, future energy use and emissions absent climate policy, the effect of urban and rural development on future energy use and emissions, the role of technology in emissions mitigation, regional emissions mitigation, and national climate policies

  4. Ab Initio No Core Shell Model - Recent Results and Further Prospects

    E-Print Network [OSTI]

    James P. Vary; Pieter Maris; Hugh Potter; Mark A. Caprio; Robin Smith; Sven Binder; Angelo Calci; Sebastian Fischer; Joachim Langhammer; Robert Roth; Hasan Metin Aktulga; Esmond Ng; Chao Yang; Dossay Oryspayev; Masha Sosonkina; Erik Saule; Ümit Çatalyürek

    2015-07-16T23:59:59.000Z

    There has been significant recent progress in solving the long-standing problems of how nuclear shell structure and collective motion emerge from underlying microscopic inter-nucleon interactions. We review a selection of recent significant results within the ab initio No Core Shell Model (NCSM) closely tied to three major factors enabling this progress: (1) improved nuclear interactions that accurately describe the experimental two-nucleon and three-nucleon interaction data; (2) advances in algorithms to simulate the quantum many-body problem with strong interactions; and (3) continued rapid development of high-performance computers now capable of performing $20 \\times 10^{15}$ floating point operations per second. We also comment on prospects for further developments.

  5. Exact results for the criticality of quench dynamics in quantum Ising models

    E-Print Network [OSTI]

    Ying Li; M. X. Huo; Z. Song

    2009-06-23T23:59:59.000Z

    Based on the obtained exact results we systematically study the quench dynamics of a one-dimensional spin-1/2 transverse field Ising model with zero- and finite-temperature initial states. We focus on the magnetization of the system after a sudden change of the external field and a coherent time-evolution process. With a zero-temperature initial state, the quench magnetic susceptibility as a function of the initial field strength exhibits strongly similar scaling behaviors to those of the static magnetic susceptibility, and the quench magnetic susceptibility as a function of the final field strength shows a discontinuity at the quantum critical point. This discontinuity remains robust and always occurs at the quantum critical point even for the case of finite-temperature initial systems, which indicates a great advantage of employing quench dynamics to study quantum phase transitions.

  6. The MIT Emissions Prediction and Policy Analysis (EPPA) model : revisions, sensitivities, and comparisons of results

    E-Print Network [OSTI]

    Babiker, Mustafa H.M.; Reilly, John M.; Mayer, Monika.; Eckaus, Richard S.; Sue Wing, Ian.; Hyman, Robert C.

    The Emissions Prediction and Policy Analysis (EPPA) model is a component of the MIT Integrated Earth Systems Model (IGSM). Here, we provide an overview of the model accessible to a broad audience and present the detailed ...

  7. Habitability of the Goldilocks Planet Gliese 581g: Results from Geodynamic Models

    E-Print Network [OSTI]

    von Bloh, W; Franck, S; Bounama, C

    2011-01-01T23:59:59.000Z

    Aims: In 2010, detailed observations have been published that seem to indicate another super-Earth planet in the system of Gliese 581 located in the midst of the stellar climatological habitable zone. The mass of the planet, known as Gl 581g, has been estimated as between 3.1 and 4.3 Earth masses. In this study, we investigate the habitability of Gl 581g based on a previously used concept that explores its long-term possibility of photosynthetic biomass production, which has already been used to gauge the principal possibility of life regarding the super-Earths Gl 581c and Gl 581d. Methods: A thermal evolution model for super-Earths is used to calculate the sources and sinks of atmospheric carbon dioxide. The habitable zone is determined by the limits of photosynthetic biological productivity on the planetary surface. Models with different ratios of land / ocean coverage are pursued. Results: The maximum time span for habitable conditions is attained for water worlds at a position of about 0.14+/-0.015 AU, wh...

  8. Sequentially Triggered Star Formation in OB Associations

    E-Print Network [OSTI]

    Thomas Preibisch; Hans Zinnecker

    2006-10-27T23:59:59.000Z

    We discuss observational evidence for sequential and triggered star formation in OB associations. We first review the star formation process in the Scorpius-Centaurus OB association, the nearest OB association to the Sun, where several recent extensive studies have allowed us to reconstruct the star formation history in a rather detailed way. We then compare the observational results with those obtained for other OB associations and with recent models of rapid cloud and star formation in the turbulent interstellar medium. We conclude that the formation of whole OB subgroups (each consisting of several thousand stars) requires large-scale triggering mechanisms such as shocks from expanding wind and supernova driven superbubbles surrounding older subgroups. Other triggering mechanisms, like radiatively driven implosion of globules, also operate, but seem to be secondary processes, forming only small stellar groups rather than whole OB subgroups with thousands of stars.

  9. Initial stages of soot formation in thermal pyrolysis of acetylene. II. A model for the incipience and growth of soot particles

    SciTech Connect (OSTI)

    Merkulov, A.A.; Ovsyannikov, A.A.; Polak, L.S.; Popov, V.T.; Pustilnikov, V.Yu. (Institute of Petrochemical Synthesis, Moscow (USSR))

    1989-03-01T23:59:59.000Z

    A model is developed which describes simultaneously occurring processes of the initial hydrocarbon pyrolysis, nucleation, surface growth, and coagulation of soot particles. The model permits one to find the size distribution of the primary soot particles up to size 30-40 nm using a relatively small set of equations. The computed time dependence of soot particle concentration agrees satisfactorily with available experimental data. The existence of two limiting stages of the soot formation is revealed.

  10. E-Print Network 3.0 - anisotropic flow model Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    same fashion in symmetry planes of more complicated anisotropic models... in anisotropic media and studied the error of conventional DMO for transversely isotropic models. He...

  11. Models of the Morphology, Kinematics, and Star Formation History of the Prototypical Collisional Starburst System: NGC 7714/7715 = Arp 284

    E-Print Network [OSTI]

    Curtis Struck; Beverly J. Smith

    2003-01-31T23:59:59.000Z

    (abridged) We present new N-body, hydrodynamical simulations of the interaction between the starburst galaxy NGC 7714 and its post-starburst companion NGC 7715, focusing on the formation of the collisional features, including: 1) the gas-rich star forming bridge, 2) the large gaseous loop (and stellar tails) to the west of the system, 3) the very extended HI tail to the west and north of NGC 7714, and 4) the partial stellar ring in NGC 7714. Our simulations confirm the results of earlier work that an off-center inclined collision between two disk galaxies is almost certainly responsible for the peculiar morphologies of this system. However, we have explored a wider set of initial galaxy and collisional encounter parameters than previously, and have found a relatively narrow range of parameters that reproduce all the major morphologies of this system. The simulations suggest specific mechanisms for the development of several unusual structures. We find that the complex gas bridge has up to four distinct components, with gas contributed from two sides of NGC 7715, as well as from NGC 7714. The observed gas-star offset in this bridge is accounted for in the simulations by the dissipative evolution of the gas. The models also indicate that the low surface brightness HI tail to the far west of NGC 7714 is the end of the NGC 7715 countertail, curved behind the two galaxies. Spectral evolutionary models of the NGC 7714 core by Lan\\c{c}on et al. suggest the possibility of multiple starbursts in the last 300 Myr. Our hydrodynamic models suggest that bursts could be triggered by induced ring-like waves, and a post-collision buildup of gas in the core of the galaxy.

  12. Numerical modeling of injection and mineral trapping of CO2 withH2S and SO2 in a Sandstone Formation

    SciTech Connect (OSTI)

    Xu, Tianfu; Apps, John A.; Pruess, Karsten; Yamamoto, Hajime

    2004-09-07T23:59:59.000Z

    Carbon dioxide (CO{sub 2}) injection into deep geologic formations could decrease the atmospheric accumulation of this gas from anthropogenic sources. Furthermore, by co-injecting H{sub 2}S or SO{sub 2}, the products respectively of coal gasification or combustion, with captured CO{sub 2}, problems associated with surface disposal would be mitigated. We developed models that simulate the co-injection of H{sub 2}S or SO{sub 2} with CO{sub 2} into an arkose formation at a depth of about 2 km and 75 C. The hydrogeology and mineralogy of the injected formation are typical of those encountered in Gulf Coast aquifers of the United States. Six numerical simulations of a simplified 1-D radial region surrounding the injection well were performed. The injection of CO{sub 2} alone or co-injection with SO{sub 2} or H{sub 2}S results in a concentrically zoned distribution of secondary minerals surrounding a leached and acidified region adjacent to the injection well. Co-injection of SO{sub 2} with CO{sub 2} results in a larger and more strongly acidified zone, and alteration differs substantially from that caused by the co-injection of H{sub 2}S or injection of CO{sub 2} alone. Precipitation of carbonates occurs within a higher pH (pH > 5) peripheral zone. Significant quantities of CO{sub 2} are sequestered by ankerite, dawsonite, and lesser siderite. The CO{sub 2} mineral-trapping capacity of the formation can attain 40-50 kg/m{sup 3} medium for the selected arkose. In contrast, secondary sulfates precipitate at lower pH (pH < 5) within the acidified zone. Most of the injected SO{sub 2} is transformed and immobilized through alunite precipitation with lesser amounts of anhydrite and minor quantities of pyrite. The dissolved CO{sub 2} increases with time (enhanced solubility trapping). The mineral alteration induced by injection of CO{sub 2} with either SO{sub 2} or H{sub 2}S leads to corresponding changes in porosity. Significant increases in porosity occur in the acidified zones where mineral dissolution dominates. With co-injection of SO{sub 2}, the porosity increases from an initial 0.3 to 0.43 after 100 years. However, within the CO{sub 2} mineral-trapping zone, the porosity decreases to about 0.28 for both cases, because of the addition of CO{sub 2} mass as secondary carbonates to the rock matrix. Precipitation of sulfates at the acidification front causes porosity to decrease to 0.23. The limited information currently available on the mineralogy of naturally occurring high-pressure CO{sub 2} reservoirs is generally consistent with our simulations.

  13. Mist/steam cooling in a heated horizontal tube -- Part 2: Results and modeling

    SciTech Connect (OSTI)

    Guo, T.; Wang, T.; Gaddis, J.L.

    2000-04-01T23:59:59.000Z

    Experimental studies on mist/steam cooling in a heated horizontal tube have been performed. Wall temperature distributions have been measured under various main steam flow rates, droplet mass ratios, and wall heat fluxes. Generally, the heat transfer performance of steam can be significantly improved by adding mist into the main flow. An average enhancement of 100% with the highest local heat transfer enhancement of 200% is achieved with 5% mist. When the test section is mildly heated, an interesting wall temperature distribution is observed: the wall temperature increases first, then decreases, and finally increases again. A three-stage heat transfer model with transition boiling, unstable liquid fragment evaporation, and dry-wall mist cooling has been proposed and has shown some success in predicting the wall temperature of the mist/steam flow. The PDPA measurements have facilitated better understanding and interpreting of the droplet dynamics and heat transfer mechanisms. Furthermore, this study has shed light on how to generate appropriate droplet sizes to achieve effective droplet transportation, and has shown that it is promising to extend present results to a higher temperature and higher pressure environment.

  14. Model for Correlating Real-Time Survey Results to Contaminant Concentrations - 12183

    SciTech Connect (OSTI)

    Walker, Stuart A. [U.S. Environmental Protection Agency, Washington, DC. 20460 (United States)

    2012-07-01T23:59:59.000Z

    The U.S. Environmental Protection Agency (EPA) Superfund program is developing a new Counts Per Minute (CPM) calculator to correlate real-time survey results, which are often expressed as counts per minute, to contaminant concentrations that are more typically provided in risk assessments or for cleanup levels, usually expressed in pCi/g or pCi/m{sup 2}. Currently there is no EPA guidance for Superfund sites on correlating count per minute field survey readings back to risk, dose, or other ARAR based concentrations. The CPM calculator is a web-based model that estimates a gamma detector response for a given level of contamination. The intent of the CPM calculator is to facilitate more real-time measurements within a Superfund response framework. The draft of the CPM calculator is still undergoing internal EPA review. This will be followed by external peer review. It is expected that the CPM calculator will at least be in peer review by the time of WM2012 and possibly finalized at that time. The CPM calculator should facilitate greater use of real-time measurement at Superfund sites. The CPM calculator may also standardize the process of converting lab data to real time measurements. It will thus lessen the amount of lab sampling that is needed for site characterization and confirmation surveys, but it will not remove the need for sampling. (authors)

  15. Modelling the molecular Zeeman effect in M-dwarfs: methods and first results

    E-Print Network [OSTI]

    Shulyak, D; Wende, S; Kochukhov, O; Piskunov, N; Seifahrt, A

    2010-01-01T23:59:59.000Z

    We present first quantitative results of the surface magnetic field measurements in selected M-dwarfs based on detailed spectra synthesis conducted simultaneously in atomic and molecular lines of the FeH Wing-Ford $F^4\\,\\Delta-X^4\\,\\Delta$ transitions. A modified version of the Molecular Zeeman Library (MZL) was used to compute Land\\'e g-factors for FeH lines in different Hund's cases. Magnetic spectra synthesis was performed with the Synmast code. We show that the implementation of different Hund's case for FeH states depending on their quantum numbers allows us to achieve a good fit to the majority of lines in a sunspot spectrum in an automatic regime. Strong magnetic fields are confirmed via the modelling of atomic and FeH lines for three M-dwarfs YZ~CMi, EV~Lac, and AD~Leo, but their mean intensities are found to be systematically lower than previously reported. A much weaker field ($1.7-2$~kG against $2.7$~kG) is required to fit FeH lines in the spectra of GJ~1224. Our method allows us to measure average...

  16. (1) Likelihood mode of inference: definitions and results (i) Reference population and model.

    E-Print Network [OSTI]

    Frangakis, Constantine

    linear regression model with non additive effect. pr" ` "! CU# ` sr)¤ P u X }|e5 ~ ra 5 ¤ A B pr models. (1) Normal linear regression model with additive effect. pr"a`"! sU# ` sr)¤ P u X }| 5~ rf 5

  17. Result Summary for the Area 5 Radioactive Waste Management Site Performance Assessment Model Version 4.113

    SciTech Connect (OSTI)

    Shott, G. J.

    2012-04-15T23:59:59.000Z

    Preliminary results for Version 4.113 of the Nevada National Security Site Area 5 Radioactive Waste Management Site performance assessment model are summarized. Version 4.113 includes the Fiscal Year 2011 inventory estimate.

  18. Combined results of searches for the standard model Higgs boson in pp collisions at ?s = 7 TeV

    E-Print Network [OSTI]

    Alver, B.

    Combined results are reported from searches for the standard model Higgs boson in proton–proton collisions at ?s = 7 TeV in five Higgs boson decay modes: ??, bb, ?? , WW, and ZZ. The explored Higgs boson mass range is ...

  19. Conclusions The results show that the models are able to predict the response of the FETi motor

    E-Print Network [OSTI]

    Sóbester, András

    Conclusions The results show that the models are able to predict the response of the FETi motor just one animal might over-fit the noise of that particular animal. However, a model designed strand transmit the movement to the sensory neurons in the FeCO, which excite the motor neurons. Design

  20. Modeling the Capacity and Emissions Impacts of Reduced Electricity Demand. Part 1. Methodology and Preliminary Results.

    E-Print Network [OSTI]

    Coughlin, Katie

    2013-01-01T23:59:59.000Z

    2011).pdf. ———. 2012a. “Annual Energy Outlook (AEO) 2012. ”2013. “Annual Energy Outlook - Model Documentation. ”forecast, the Annual Energy Outlook (AEO) (DOE EIA 2012a).

  1. Test Results and Modeling of the Honda Insight Using ADVISOR: Preprint

    SciTech Connect (OSTI)

    Kelly, K. J.; Zolot, M. (National Renewable Energy Laboratory); Glinsky, G.; Hieronymus, A. (Environmental Testing Corporation)

    2001-08-01T23:59:59.000Z

    Paper describing a series of chassis dynamometer and road tests that NREL conducted on the 2000 model-year Honda Insight.

  2. E-Print Network 3.0 - analysis model gsam Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Materials Science, Rice University Collection: Engineering 2 2010 Advocate Health Care. All Rights Reserved. Table of Contents Summary: and have launched a redesigned model...

  3. Uncertainty and Sensitivity Analysis of Damage Identification Results Obtained Using Finite Element Model Updating

    E-Print Network [OSTI]

    Moaveni, Babak; Conte, Joel P; Hemez, François M

    2009-01-01T23:59:59.000Z

    modeling error). A full factorial design of experiments iserror) (E). A full factorial design of experiments isnumerical). A full-factorial design of experiments is used

  4. Controls on advance of tidewater glaciers: results from numerical modeling applied to Columbia Glacier

    E-Print Network [OSTI]

    Nick, F. M.; van der Veen, Cornelis J.; Oerlemans, J.

    2007-07-11T23:59:59.000Z

    A one-dimensional numerical ice flow model is used to study the advance of a tidewater glacier into deep water. Starting with ice-free conditions, the model simulates glacier growth at higher elevations followed by advance on land to the head...

  5. MECHANICAL TEST RESULTS ON DIPOLE MODEL C-l 25 mm ALUMINUM COLLARS

    E-Print Network [OSTI]

    Peters, C.

    2010-01-01T23:59:59.000Z

    P~. FI'9 . ~ C.C rv'IW\\ 707~-Th ALUMINUM ' ~LAI2.. o Pl.ATTDIPOLE MODEL C-1 25 mm ALUMINUM COLLARS C. Peters FebruaryON DIPOLE MODEL C-I 25 mm ALUMINUM COLLARS· Craig Peters

  6. What is the effect of LiDAR-derived DEM resolution on large-scale watershed model results?

    SciTech Connect (OSTI)

    Ping Yang; Daniel B. Ames; Andre Fonseca; Danny Anderson; Rupesh Shrestha; Nancy F. Glenn; Yang Cao

    2014-08-01T23:59:59.000Z

    This paper examines the effect of raster cell size on hydrographic feature extraction and hydrological modeling using LiDAR derived DEMs. LiDAR datasets for three experimental watersheds were converted to DEMs at various cell sizes. Watershed boundaries and stream networks were delineated from each DEM and were compared to reference data. Hydrological simulations were conducted and the outputs were compared. Smaller cell size DEMs consistently resulted in less difference between DEM-delineated features and reference data. However, minor differences been found between streamflow simulations resulted for a lumped watershed model run at daily simulations aggregated at an annual average. These findings indicate that while higher resolution DEM grids may result in more accurate representation of terrain characteristics, such variations do not necessarily improve watershed scale simulation modeling. Hence the additional expense of generating high resolution DEM's for the purpose of watershed modeling at daily or longer time steps may not be warranted.

  7. Impact of hydrological variations on modeling of peatland CO2 fluxes: Results from the North American Carbon Program

    E-Print Network [OSTI]

    Wisconsin at Madison, University of

    in ecosystem models due to differences in nutrients, peat properties, and plant communities. Citation: Sulman cycle due to large carbon pools resulting from the long-term accumulation of organic matter in peat of the water table exposes peat soils to oxygen, resulting in higher rates of ecosystem respiration (ER

  8. Sequestration of Dissolved CO2 in the Oriskany Formation

    SciTech Connect (OSTI)

    Dilmore, R.M.; Allen, D.E. (Salem State College, Salem, MA); McCarthy-Jones, J.R.; Hedges, S.W.; Soong, Yee

    2008-04-15T23:59:59.000Z

    Experiments were conducted to determine the solubility of CO2 in a natural brine solution of the Oriskany formation under elevated temperature and pressure conditions. These data were collected at temperatures of 22 and 75 °C and pressures between 100 and 450 bar. Experimentally determined data were compared with CO2 solubility predictions using a model developed by Duan and Sun (Chem. Geol. 2003, 193, 257-271). Model results compare well with Oriskany brine CO2 solubility data collected experimentally, suggesting that the Duan and Sun model is a reliable tool for estimating solution CO2 capacity in high salinity aquifers in the temperature and pressure range evaluated. The capacity for the Oriskany formation to sequester dissolved CO2 was calculated using results of the solubility models, estimation of the density of CO2 saturated brine, and available geographic information system (GIS) information on the formation depth and thickness. Results indicate that the Oriskany formation can hold approximately 0.36 gigatonnes of dissolved CO2 if the full basin is considered. When only the region where supercritical CO2 can exist (temperatures greater than 31° C and pressures greater than 74 bar) is considered, the capacity of the Oriskany formation to sequester dissolved CO2 is 0.31 gigatonnes. The capacity estimate considering the potential to sequester free-phase supercritical CO2 if brine were displaced from formation pore space is 8.8 gigatonnes in the Oriskany formation.

  9. Diurnal cycle of air pollution in the Kathmandu Valley, Nepal: 2. Modeling results

    E-Print Network [OSTI]

    Panday, Arnico K.

    After completing a 9-month field experiment studying air pollution and meteorology in the Kathmandu Valley, Nepal, we set up the mesoscale meteorological model MM5 to simulate the Kathmandu Valley's meteorology with a ...

  10. Improved Building Energy Performance Modelling through Comparison of Measured Data with Simulated Results 

    E-Print Network [OSTI]

    Bambrook, S.; Jacob, D.

    2008-01-01T23:59:59.000Z

    -ICE for the same building. The dataset collected at the demonstration building consists of total energy consumption, weather data, indoor conditions and HVAC system parameters, measured in at least hourly time steps. This paper presents the first steps in modelling...

  11. RHF RELAP5 Model and Preliminary Loss-Of-Offsite-Power Simulation Results for LEU Conversion

    SciTech Connect (OSTI)

    Licht, J. R. [Argonne National Laboratory (ANL), Argonne, IL (United States). Nuclear Engineering Div.; Bergeron, A. [Argonne National Laboratory (ANL), Argonne, IL (United States). Nuclear Engineering Div.; Dionne, B. [Argonne National Laboratory (ANL), Argonne, IL (United States). Nuclear Engineering Div.; Thomas, F. [Institut Laue-Langevin (ILL), Grenoble (Switzerland). RHF Reactor Dept.

    2014-08-01T23:59:59.000Z

    The purpose of this document is to describe the current state of the RELAP5 model for the Institut Laue-Langevin High Flux Reactor (RHF) located in Grenoble, France, and provide an update to the key information required to complete, for example, simulations for a loss of offsite power (LOOP) accident. A previous status report identified a list of 22 items to be resolved in order to complete the RELAP5 model. Most of these items have been resolved by ANL and the RHF team. Enough information was available to perform preliminary safety analyses and define the key items that are still required. Section 2 of this document describes the RELAP5 model of RHF. The final part of this section briefly summarizes previous model issues and resolutions. Section 3 of this document describes preliminary LOOP simulations for both HEU and LEU fuel at beginning of cycle conditions.

  12. Improved Building Energy Performance Modelling through Comparison of Measured Data with Simulated Results

    E-Print Network [OSTI]

    Bambrook, S.; Jacob, D.

    -ICE for the same building. The dataset collected at the demonstration building consists of total energy consumption, weather data, indoor conditions and HVAC system parameters, measured in at least hourly time steps. This paper presents the first steps in modelling...

  13. E-Print Network 3.0 - aerosol generator model Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    S N E E T A L . 2002 American Meteorological Society Summary: by no more than 10% of the cooling caused by aerosols. 1. Introduction Observations and models highlight......

  14. Headcut retreat resulting from plunge pool erosion in a 3D landscape evolution model

    E-Print Network [OSTI]

    Flores Cervantes, Javier Homero, 1977-

    2004-01-01T23:59:59.000Z

    Headcut retreat produced by plunge pools is represented using existing concepts about this type of erosion. The model estimates retreat rates, given flow, height of the headcut, upstream slope and Manning's roughness, and ...

  15. Performance of VAV Fan Powered Terminal Units: Experimental Results and Models for Parallel Units

    E-Print Network [OSTI]

    Furr, J.; O'Neal, D.; Davis, M.; Bryant, J.; Cramlet, A.

    ©2008 ASHRAE 83 ABSTRACT Empirical models of airflow output, power consumption, and primary airflow were developed for parallel fan powered variable air volume terminal units at typical operating pres- sures. Both 8 in. (203 mm) and 12 in. (304 mm...) primary air inlet terminal units from three manufacturers were evaluated. Generalized models were developed from the experimental data with coefficients varying by size and manufacturer. Fan power and airflow data were collected at down- stream static...

  16. Monolithic or hierarchical star formation? A new statistical analysis

    E-Print Network [OSTI]

    Marios Kampakoglou; Roberto Trotta; Joe Silk

    2007-11-23T23:59:59.000Z

    We consider an analytic model of cosmic star formation which incorporates supernova feedback, gas accretion and enriched outflows, reproducing the history of cosmic star formation, metallicity, supernovae type II rates and the fraction of baryons allocated to structures. We present a new statistical treatment of the available observational data on the star formation rate and metallicity that accounts for the presence of possible systematics. We then employ a Bayesian Markov Chain Monte Carlo method to compare the predictions of our model with observations and derive constraints on the 7 free parameters of the model. We find that the dust correction scheme one chooses to adopt for the star formation data is critical in determining which scenario is favoured between a hierarchical star formation model, where star formation is prolonged by accretion, infall and merging, and a monolithic scenario, where star formation is rapid and efficient. We distinguish between these modes by defining a characteristic minimum mass, M > 10^{11} M_solar, in our fiducial model, for early type galaxies where star formation occurs efficiently. Our results indicate that the hierarchical star formation model can achieve better agreement with the data, but that this requires a high efficiency of supernova-driven outflows. In a monolithic model, our analysis points to the need for a mechanism that drives metal-poor winds, perhaps in the form of supermassive black hole-induced outflows. Furthermore, the relative absence of star formation beyond z ~ 5 in the monolithic scenario requires an alternative mechanism to dwarf galaxies for reionizing the universe at z ~ 11, as required by observations of the microwave background. While the monolithic scenario is less favoured in terms of its quality-of-fit, it cannot yet be excluded.

  17. Increase of Carbon Cycle Feedback with Climate Sensitivity: Results from a coupled Climate and Carbon Cycle Model

    SciTech Connect (OSTI)

    Govindasamy, B; Thompson, S; Mirin, A; Wickett, M; Caldeira, K; Delire, C

    2004-04-01T23:59:59.000Z

    Coupled climate and carbon cycle modeling studies have shown that the feedback between global warming and the carbon cycle, in particular the terrestrial carbon cycle, could accelerate climate change and result in larger warming. In this paper, we investigate the sensitivity of this feedback for year-2100 global warming in the range of 0 K to 8 K. Differing climate sensitivities to increased CO{sub 2} content are imposed on the carbon cycle models for the same emissions. Emissions from the SRES A2 scenario are used. We use a fully-coupled climate and carbon cycle model, the INtegrated Climate and CArbon model (INCCA) the NCAR/DOE Parallel Coupled Model coupled to the IBIS terrestrial biosphere model and a modified-OCMIP ocean biogeochemistry model. In our model, for scenarios with year-2100 global warming increasing from 0 to 8 K, land uptake decreases from 47% to 29% of total CO{sub 2} emissions. Due to competing effects, ocean uptake (16%) shows almost no change at all. Atmospheric CO{sub 2} concentration increases were 48% higher in the run with 8 K global climate warming than in the case with no warming. Our results indicate that carbon cycle amplification of climate warming will be greater if there is higher climate sensitivity to increased atmospheric CO{sub 2} content; the carbon cycle feedback factor increases from 1.13 to 1.48 when global warming increases from 3.2 to 8 K.

  18. Performance of VAV Fan Powered Terminal Units: Experimental Results and Models for Series Units

    E-Print Network [OSTI]

    Furr, J.; O'Neal, D.; Davis, M.; Bryant, J.; Cramlet, A.

    ©2008 ASHRAE 91 ABSTRACT Empirical models of airflow output and power consump- tion were developed for series fan powered variable air volume terminal units at typical operating pressures. Terminal units with 8 in. (203 mm) and 12 in. (304 mm... pressures of 0.25 w.g. (63 Pa). Upstream static pressures ranged from 0.1 to 2.0 in w.g. (25 to 498 Pa). Data were collected at four different primary air damper positions and at four terminal unit fan speeds. Model variables included the RMS voltage...

  19. Critical assessment of the first results of the EFOM 12C model. Final report

    SciTech Connect (OSTI)

    Thonet, C.; Van der Voort, E.; Love, P.; Jadot, P.

    1984-01-01T23:59:59.000Z

    EFOM 12C is intended to model the development and utilization of energy in the European Community for the next forty years. While the actual outcome of energy utilization is totally dependent on human decisions, it was considered to be valuable to model energy development, demand, and utilization for five scenarios. They were:- (a) 'reference case' in which overall costs were minimized, (b) 'mining case' in which imports were minimized, (c) 'decay' where the costs of production were minimized but with no other constraints, (d) 'autonomous case' with import costs limited within an overall cost constraint, and (e) 'dependency case' in which the investment costs were minimized within an overall cost constraint.

  20. Preliminary results of a dynamic system model for a closed-loop Brayton cycle coupled to a nuclear reactor.

    SciTech Connect (OSTI)

    Wright, Steven Alan

    2003-06-01T23:59:59.000Z

    This paper describes preliminary results of a dynamic system model for a closed-loop Brayton-cycle that is coupled to a nuclear reactor. The current model assumes direct coupling between the reactor and the Brayton-cycle, however only minor additions are required to couple the Brayton-cycle through a heat exchanger to either a heat pipe reactor or a liquid metal cooled reactor. Few reactors have ever been coupled to closed Brayton-cycle systems. As such their behavior under dynamically varying loads, startup and shut down conditions, and requirements for safe and autonomous operation are largely unknown. Sandia National Laboratories has developed steady-state and dynamic models for closed-loop turbo-compressor systems (for space and terrestrial applications). These models are expected to provide a basic understanding of the dynamic behavior and stability of the coupled reactor and power generation loop. The model described in this paper is a lumped parameter model of the reactor, turbine, compressor, recuperator, radiator/waste-heat-rejection system and generator. More detailed models that remove the lumped parameter simplifications are also being developed but are not presented here. The initial results of the model indicate stable operation of the reactor-driven Brayton-cycle system and its ability to load-follow. However, the model also indicates some counter-intuitive behavior for the complete coupled system. This behavior will require the use of a reactor control system to select an appropriate reactor operating temperature that will optimize the performance of the complete spacecraft system. We expect this model and subsequent versions of it to provide crucial information in developing procedures for safe start up, shut down, safe-standby, and other autonomous operating modes. Ultimately, Sandia hopes to validate these models and to perform nuclear ground tests of reactor-driven closed Brayton-cycle systems in our nuclear research facilities.

  1. Case Studies Comparing System Advisor Model (SAM) Results to Real Performance Data: Preprint

    SciTech Connect (OSTI)

    Blair, N.; Dobos, A.; Sather, N.

    2012-06-01T23:59:59.000Z

    NREL has completed a series of detailed case studies comparing the simulations of the System Advisor Model (SAM) and measured performance data or published performance expectations. These case studies compare PV measured performance data with simulated performance data using appropriate weather data. The measured data sets were primarily taken from NREL onsite PV systems and weather monitoring stations.

  2. Late breaking results: ARPipes: Aligning Virtual models to their Physical Counterparts with Spatial Augmented Reality

    E-Print Network [OSTI]

    Thomas, Bruce

    models to their physical representation. ARPipes provides both a visual overlay of physical plant. The paper describes the process of employing original CAD data of plant equipment and transforming the data with maintenance tasks in fabrication plants. This paper presents the first step in the AR process, the visual

  3. A Multi-FhJid CFD Turbulent Entrainment Combustion Model: Formulation and One-Dimensional Results

    E-Print Network [OSTI]

    and physical processes that occur during combustion. Short time scales and extremes in temperature and pressure chamber and to predict conditions at the time of spark [1,2]. However, only in the last several years has controlled PREPRINT 1997 SAE Fall Fuels and Lubricants Meeting #12;models of Magnuussen [

  4. Carbon pools in Mediterranean forests: comparing eddy covariance and GOTILWA+ model results.

    E-Print Network [OSTI]

    Gracia, Carlos

    , FLUXNET, Modelling, drought-stress, Mediterranean climate Introduction Changes in regional and global of climate change, where it becomes essential to have an understanding of the future role of terrestrial climate have already been observed, and projections of climate change suggest that higher temperatures

  5. Formation of double-$?$ hypernuclei at PANDA

    E-Print Network [OSTI]

    T. Gaitanos; A. B. Larionov; H. Lenske; U. Mosel

    2012-01-17T23:59:59.000Z

    We study the formation of single- and double-$\\Lambda$ hypernuclei in antiproton-induced reactions relevant for the forthcoming PANDA experiment at FAIR. We use the Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) transport model with relativistic mean-fields for the description of non-equilibrium dynamics and the statistical multifragmentation model (SMM) for fragment formation. This combined approach describes the dynamical properties of strangeness and fragments in low energy $\\bar{p}$-induced reactions fairly well. We then focus on the formation of double-$\\Lambda$ hypernuclei in high energy $\\bar{p}$-nucleus collisions on a primary target including the complementary $\\Xi$-induced reactions to a secondary one, as proposed by the PANDA collaboration. Our results show that a copious production of double-$\\Lambda$ hyperfragments is possible at PANDA. In particular, we provide first theoretical estimations on the double-$\\Lambda$ production cross section, which strongly rises with decreasing energy of the secondary $\\Xi$-beam.

  6. Galaxy formation with radiative and chemical feedback

    E-Print Network [OSTI]

    Graziani, L; Schneider, R; Kawata, D; de Bennassuti, M; Maselli, A

    2015-01-01T23:59:59.000Z

    Here we introduce GAMESH, a novel pipeline which implements self-consistent radiative and chemical feedback in a computational model of galaxy formation. By combining the cosmological chemical-evolution model GAMETE with the radiative transfer code CRASH, GAMESH can post process realistic outputs of a N-body simulation describing the redshift evolution of the forming galaxy. After introducing the GAMESH implementation and its features, we apply the code to a low-resolution N-body simulation of the Milky Way formation and we investigate the combined effects of self-consistent radiative and chemical feedback. Many physical properties, which can be directly compared with observations in the Galaxy and its surrounding satellites, are predicted by the code along the merger-tree assembly. The resulting redshift evolution of the Local Group star formation rates, reionisation and metal enrichment along with the predicted Metallicity Distribution Function of halo stars are critically compared with observations. We dis...

  7. ISO-SWS calibration and the accurate modelling of cool-star atmospheres - II. General results

    E-Print Network [OSTI]

    L. Decin; B. Vandenbussche; C. Waelkens; K. Eriksson; B. Gustafsson; B. Plez; A. J. Sauval; K. Hinkle

    2002-07-29T23:59:59.000Z

    The fine calibration of the ISO-SWS detectors (Infrared Space Observatory - Short Wavelength Spectrometer) has proven to be a delicate problem. We therefore present a detailed spectroscopic study in the 2.38 -- 12 micron wavelength range of a sample of 16 A0 -- M2 stars used for the calibration of ISO-SWS. By investigating the discrepancies between the ISO-SWS data of these sources, the theoretical predictions of their spectra, the high-resolution FTS-KP (Kitt Peak) spectrum of Alpha Boo and the solar FTS-ATMOS (Atmospheric Trace Molecule Spectroscopy) spectrum, both calibration problems and problems in computing the theoretical models and the synthetic spectra are revealed. The underlying reasons for these problems are sought for and the impact on the further calibration of ISO-SWS and on the theoretical modelling is discussed extensively.

  8. Exact theory and numeric results for short pulse ionization of simple model atom in one dimension

    E-Print Network [OSTI]

    Rokhlenko, Alexander

    2015-01-01T23:59:59.000Z

    Our exact theory for continuous harmonic perturbation of a one dimensional model atom by parametric variations of its potential is generalized for the cases when a) the atom is exposed to short pulses of an external harmonic electric field and b) the forcing is represented by short bursts of different shape changing the strength of the binding potential. This work is motivated not only by the wide use of laser pulses for atomic ionization, but also by our earlier study of the same model which successfully described the ionization dynamics in all orders, i.e. the multi-photon processes, though being treated by the non-relativistic Schr\\"odinger equation. In particular, it was shown that the bound atom cannot survive the excitation of its potential caused by any non-zero frequency and amplitude of the continuous harmonic forcing. Our present analysis found important laws of the atomic ionization by short pulses, in particular the efficiency of ionizing this model system and presumably real ones as well.

  9. Star formation in the multiverse

    SciTech Connect (OSTI)

    Bousso, Raphael; Leichenauer, Stefan [Center for Theoretical Physics, Department of Physics, University of California, Berkeley, California 94720-7300 (United States) and Lawrence Berkeley National Laboratory, Berkeley, California 94720-8162 (United States)

    2009-03-15T23:59:59.000Z

    We develop a simple semianalytic model of the star formation rate as a function of time. We estimate the star formation rate for a wide range of values of the cosmological constant, spatial curvature, and primordial density contrast. Our model can predict such parameters in the multiverse, if the underlying theory landscape and the cosmological measure are known.

  10. Observing Massive Galaxy Formation

    E-Print Network [OSTI]

    Christopher J. Conselice

    2002-12-20T23:59:59.000Z

    A major goal of contemporary astrophysics is understanding the origin of the most massive galaxies in the universe, particularly nearby ellipticals and spirals. Theoretical models of galaxy formation have existed for many decades, although low and high redshift observations are only beginning to put constraints on different ideas. We briefly describe these observations and how they are revealing the methods by which galaxies form by contrasting and comparing fiducial rapid collapse and hierarchical formation model predictions. The available data show that cluster ellipticals must have rapidly formed at z > 2, and that up to 50% of all massive galaxies at z ~ 2.5 are involved in major mergers. While the former is consistent with the monolithic collapse picture, we argue that hierarchal formation is the only model that can reproduce all the available observations.

  11. Stratified chaos in a sand pile formation

    E-Print Network [OSTI]

    Ate Poortinga; Jan G. Wesseling; Coen J. Ritsema

    2014-03-04T23:59:59.000Z

    Sand pile formation is often used to describe stratified chaos in dynamic systems due to self-emergent and scale invariant behaviour. Cellular automata (Bak-Tang-Wiesenfeld model) are often used to describe chaotic behaviour, as simulating physical interactions between individual particles is computationally demanding. In this study, we use a state-of-the-art parallel implementation of the discrete element method on the graphical processing unit to simulate sand pile formation. Interactions between individual grains were simulated using a contact model in an Euler integration scheme. Results show non-linear self-emergent behaviour which is in good agreement with experimental results, theoretical work and self organized criticality (SOC) approaches. Moreover, it was found that the fully deterministic model, where the position and forces on every individual particle can be determined every iteration has a brown noise signal in the x and y direction, where the signal is the z direction is closer to a white noise spectrum.

  12. U.S. Department of Energy Reference Model Program RM2: Experimental Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin Transition in2,EHSS A-Zandofpoint motional%^6 AnnualReference Model

  13. Predictions from star formation in the multiverse

    SciTech Connect (OSTI)

    Bousso, Raphael; Leichenauer, Stefan [Center for Theoretical Physics, Department of Physics, University of California, Berkeley, California 94720-7300 (United States) and Lawrence Berkeley National Laboratory, Berkeley, California 94720-8162 (United States)

    2010-03-15T23:59:59.000Z

    We compute trivariate probability distributions in the landscape, scanning simultaneously over the cosmological constant, the primordial density contrast, and spatial curvature. We consider two different measures for regulating the divergences of eternal inflation, and three different models for observers. In one model, observers are assumed to arise in proportion to the entropy produced by stars; in the others, they arise at a fixed time (5 or 10x10{sup 9} years) after star formation. The star formation rate, which underlies all our observer models, depends sensitively on the three scanning parameters. We employ a recently developed model of star formation in the multiverse, a considerable refinement over previous treatments of the astrophysical and cosmological properties of different pocket universes. For each combination of observer model and measure, we display all single and bivariate probability distributions, both with the remaining parameter(s) held fixed and marginalized. Our results depend only weakly on the observer model but more strongly on the measure. Using the causal diamond measure, the observed parameter values (or bounds) lie within the central 2{sigma} of nearly all probability distributions we compute, and always within 3{sigma}. This success is encouraging and rather nontrivial, considering the large size and dimension of the parameter space. The causal patch measure gives similar results as long as curvature is negligible. If curvature dominates, the causal patch leads to a novel runaway: it prefers a negative value of the cosmological constant, with the smallest magnitude available in the landscape.

  14. Predictions from Star Formation in the Multiverse

    E-Print Network [OSTI]

    Raphael Bousso; Stefan Leichenauer

    2009-07-28T23:59:59.000Z

    We compute trivariate probability distributions in the landscape, scanning simultaneously over the cosmological constant, the primordial density contrast, and spatial curvature. We consider two different measures for regulating the divergences of eternal inflation, and three different models for observers. In one model, observers are assumed to arise in proportion to the entropy produced by stars; in the others, they arise at a fixed time (5 or 10 billion years) after star formation. The star formation rate, which underlies all our observer models, depends sensitively on the three scanning parameters. We employ a recently developed model of star formation in the multiverse, a considerable refinement over previous treatments of the astrophysical and cosmological properties of different pocket universes. For each combination of observer model and measure, we display all single and bivariate probability distributions, both with the remaining parameter(s) held fixed, and marginalized. Our results depend only weakly on the observer model but more strongly on the measure. Using the causal diamond measure, the observed parameter values (or bounds) lie within the central $2\\sigma$ of nearly all probability distributions we compute, and always within $3\\sigma$. This success is encouraging and rather nontrivial, considering the large size and dimension of the parameter space. The causal patch measure gives similar results as long as curvature is negligible. If curvature dominates, the causal patch leads to a novel runaway: it prefers a negative value of the cosmological constant, with the smallest magnitude available in the landscape.

  15. Initial Simulation Results of Storm-Time Ring Current in a Self-Consistent Magnetic Field Model

    E-Print Network [OSTI]

    Lyons, Larry

    , and electrons. The ring current is greatly intensified during geomagnetic storms, and produces large measurement of the magnetic disturbances from all magnetospheric currents on the surface of the EarthInitial Simulation Results of Storm-Time Ring Current in a Self-Consistent Magnetic Field Model S

  16. Considerable ModelData Mismatch in Temperature over China during the Mid-Holocene: Results of PMIP Simulations

    E-Print Network [OSTI]

    solar radiation at the top of the at- mosphere over China during the mid-Holocene. TemperatureConsiderable Model­Data Mismatch in Temperature over China during the Mid-Holocene: Results of PMIP Center, Chinese Academy of Sciences, Beijing, China XIANMEI LANG International Center for Climate

  17. Vista at CDF: Results of a model-independent search for new physics in 927 pb**-1 at CDF

    SciTech Connect (OSTI)

    Choudalakis, Georgios; /MIT, LNS

    2007-10-01T23:59:59.000Z

    A global, model-independent search for high-pT exotic phenomena is presented using 927 pb{sup -1} of CDF II data. The search algorithms employed in this analysis are Vista and Sleuth. These proceedings focus on Vista, including a description of the method and a summary of results.

  18. result formats | OpenEI Community

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit withTianlinPapersWindey Wind Home Rmckeel'slinkedpolicy

  19. Help:FormattingResults | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2,AUDIT REPORTEnergyFarms AHefei Sungrow Power SupplyProvidingsearchesHelp

  20. OpenEI Community - result formats

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOfRoseConcernsCompany Oil and GasOff<div/0

  1. Process of Integrating Screening and Detailed Risk-based Modeling Analyses to Ensure Consistent and Scientifically Defensible Results

    SciTech Connect (OSTI)

    Buck, John W.; McDonald, John P.; Taira, Randal Y.

    2002-11-01T23:59:59.000Z

    To support cleanup and closure of these tanks, modeling is performed to understand and predict potential impacts to human health and the environment. Pacific Northwest National Laboratory developed a screening tool for the United States Department of Energy, Office of River Protection that estimates the long-term human health risk, from a strategic planning perspective, posed by potential tank releases to the environment. This tool is being conditioned to more detailed model analyses to ensure consistency between studies and to provide scientific defensibility. Once the conditioning is complete, the system will be used to screen alternative cleanup and closure strategies. The integration of screening and detailed models provides consistent analyses, efficiencies in resources, and positive feedback between the various modeling groups. This approach of conditioning a screening methodology to more detailed analyses provides decision-makers with timely and defensible information and increases confidence in the results on the part of clients, regulators, and stakeholders.

  2. Evaluation of Model Results and Measured Performance of Net-Zero Energy Homes in Hawaii: Preprint

    SciTech Connect (OSTI)

    Norton, P.; Kiatreungwattana, K.; Kelly, K. J.

    2013-03-01T23:59:59.000Z

    The Kaupuni community consists of 19 affordable net-zero energy homes that were built within the Waianae Valley of Oahu, Hawaii in 2011. The project was developed for the native Hawaiian community led by the Department of Hawaiian Homelands. This paper presents a comparison of the modeled and measured energy performance of the homes. Over the first year of occupancy, the community as a whole performed within 1% of the net-zero energy goals. The data show a range of performance from house to house with the majority of the homes consistently near or exceeding net-zero, while a few fall short of the predicted net-zero energy performance. The impact of building floor plan, weather, and cooling set point on this comparison is discussed. The project demonstrates the value of using building energy simulations as a tool to assist the project to achieve energy performance goals. Lessons learned from the energy performance monitoring has had immediate benefits in providing feedback to the homeowners, and will be used to influence future energy efficient designs in Hawaii and other tropical climates.

  3. Uncertainty and sensitivity analysis of early exposure results with the MACCS Reactor Accident Consequence Model

    SciTech Connect (OSTI)

    Helton, J.C. [Arizona State Univ., Tempe, AZ (United States); Johnson, J.D. [GRAM, Inc., Albuquerque, NM (United States); McKay, M.D. [Los Alamos National Lab., NM (United States); Shiver, A.W.; Sprung, J.L. [Sandia National Labs., Albuquerque, NM (United States)

    1995-01-01T23:59:59.000Z

    Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis and stepwise regression analysis are used in an investigation with the MACCS model of the early health effects associated with a severe accident at a nuclear power station. The primary purpose of this study is to provide guidance on the variables to be considered in future review work to reduce the uncertainty in the important variables used in the calculation of reactor accident consequences. The effects of 34 imprecisely known input variables on the following reactor accident consequences are studied: number of early fatalities, number of cases of prodromal vomiting, population dose within 10 mi of the reactor, population dose within 1000 mi of the reactor, individual early fatality probability within 1 mi of the reactor, and maximum early fatality distance. When the predicted variables are considered collectively, the following input variables were found to be the dominant contributors to uncertainty: scaling factor for horizontal dispersion, dry deposition velocity, inhalation protection factor for nonevacuees, groundshine shielding factor for nonevacuees, early fatality hazard function alpha value for bone marrow exposure, and scaling factor for vertical dispersion.

  4. NIF Periscope Wall Modal Study Comparison of Results for 2 FEA Models with 2 Modal Tests

    SciTech Connect (OSTI)

    Eli, M W; Gerhard, M A; Lee, C L; Sommer, S C; Woehrle, T G

    2000-10-26T23:59:59.000Z

    This report summarizes experimentally and numerically determined modal properties for one of the reinforced concrete end walls of the NIF Periscope Support Structure in Laser Bay 1. Two methods were used to determine these modal properties: (1) Computational finite-element analyses (modal extraction process); and (2) Experimental modal analysis based on measured test data. This report also includes experimentally determined modal properties for a prototype LM3/Polarizer line-replaceable unit (LRU) and a prototype PEPC LRU. Two important parameters, used during the design phase, are validated through testing [ref 1]. These parameters are the natural frequencies and modal damping (of the system in question) for the first several global modes of vibration. Experimental modal testing provides these modal values, along with the corresponding mode shapes. Another important parameter, the input excitation (expected during normal operation of the NIF laser system) [ref 1], can be verified by performing a series of ambient vibration measurements in the vicinity of the particular system (or subsystem) of interest. The topic of ambient input excitation will be covered in a separate report. Due to the large mass of the Periscope Pedestal, it is difficult to excite the entire series of Periscope Pedestal Walls all at once. It was decided that the experimental modal tests would be performed on just one Periscope End Wall in Laser Bay 1. Experimental modal properties for the Periscope End Wall have been used to validate and update the FE analyses. Results from the analyses and modal tests support the conclusion that the Periscope Pedestal will not exceed the stability budget, which is described in reference 1. The results of the modal tests for the Periscope End Wall in Laser Bay 1 have provided examples of modal properties that can be derived from future modal tests of the entire Periscope Assembly (excluding the LRU's). This next series of larger modal tests can be performed after the support structure for the Periscope Assembly has been completed. There are five optical elements in the Periscope Assembly: PEPC; Polarizer; LM3; LM2; and the Periscope Light Source. All of these optical elements have stability requirements except for the PEPC. During the Title II Design phase, two prototypes of the LM3/Polarizer LRU were used in two different series of modal tests [ref 2,3]. A similar series of modal tests were conducted on a prototype of the PEPC LRU. The results of the modal tests were used to verify the modal properties assumed for use in the corresponding finite-element analyses.

  5. Uncertainty and sensitivity analysis of food pathway results with the MACCS Reactor Accident Consequence Model

    SciTech Connect (OSTI)

    Helton, J.C. [Arizona State Univ., Tempe, AZ (United States); Johnson, J.D.; Rollstin, J.A. [GRAM, Inc., Albuquerque, NM (United States); Shiver, A.W.; Sprung, J.L. [Sandia National Labs., Albuquerque, NM (United States)

    1995-01-01T23:59:59.000Z

    Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis and stepwise regression analysis are used in an investigation with the MACCS model of the food pathways associated with a severe accident at a nuclear power station. The primary purpose of this study is to provide guidance on the variables to be considered in future review work to reduce the uncertainty in the important variables used in the calculation of reactor accident consequences. The effects of 87 imprecisely-known input variables on the following reactor accident consequences are studied: crop growing season dose, crop long-term dose, milk growing season dose, total food pathways dose, total ingestion pathways dose, total long-term pathways dose, area dependent cost, crop disposal cost, milk disposal cost, condemnation area, crop disposal area and milk disposal area. When the predicted variables are considered collectively, the following input variables were found to be the dominant contributors to uncertainty: fraction of cesium deposition on grain fields that is retained on plant surfaces and transferred directly to grain, maximum allowable ground concentrations of Cs-137 and Sr-90 for production of crops, ground concentrations of Cs-134, Cs-137 and I-131 at which the disposal of milk will be initiated due to accidents that occur during the growing season, ground concentrations of Cs-134, I-131 and Sr-90 at which the disposal of crops will be initiated due to accidents that occur during the growing season, rate of depletion of Cs-137 and Sr-90 from the root zone, transfer of Sr-90 from soil to legumes, transfer of Cs-137 from soil to pasture, transfer of cesium from animal feed to meat, and the transfer of cesium, iodine and strontium from animal feed to milk.

  6. Uncertainty and sensitivity analysis of chronic exposure results with the MACCS reactor accident consequence model

    SciTech Connect (OSTI)

    Helton, J.C. [Arizona State Univ., Tempe, AZ (United States); Johnson, J.D.; Rollstin, J.A. [Gram, Inc., Albuquerque, NM (United States); Shiver, A.W.; Sprung, J.L. [Sandia National Labs., Albuquerque, NM (United States)

    1995-01-01T23:59:59.000Z

    Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis and stepwise regression analysis are used in an investigation with the MACCS model of the chronic exposure pathways associated with a severe accident at a nuclear power station. The primary purpose of this study is to provide guidance on the variables to be considered in future review work to reduce the uncertainty in the important variables used in the calculation of reactor accident consequences. The effects of 75 imprecisely known input variables on the following reactor accident consequences are studied: crop growing season dose, crop long-term dose, water ingestion dose, milk growing season dose, long-term groundshine dose, long-term inhalation dose, total food pathways dose, total ingestion pathways dose, total long-term pathways dose, total latent cancer fatalities, area-dependent cost, crop disposal cost, milk disposal cost, population-dependent cost, total economic cost, condemnation area, condemnation population, crop disposal area and milk disposal area. When the predicted variables are considered collectively, the following input variables were found to be the dominant contributors to uncertainty: dry deposition velocity, transfer of cesium from animal feed to milk, transfer of cesium from animal feed to meat, ground concentration of Cs-134 at which the disposal of milk products will be initiated, transfer of Sr-90 from soil to legumes, maximum allowable ground concentration of Sr-90 for production of crops, fraction of cesium entering surface water that is consumed in drinking water, groundshine shielding factor, scale factor defining resuspension, dose reduction associated with decontamination, and ground concentration of 1-131 at which disposal of crops will be initiated due to accidents that occur during the growing season.

  7. Glaciation and saline-freshwater mixing as a possible cause of cave formation in the eastern midcontinent region of the United States: A conceptual model

    SciTech Connect (OSTI)

    Panno, S.V. (Illinois State Geological Survey, Champaign (USA)); Bourcier, W.L. (Lawrence Livermore National Lab., CA (USA))

    1990-08-01T23:59:59.000Z

    We present a hypothesis for the formation of caves and associated karst features near the southern margins of the Illinois, Michigan, and Appalachian basins. Spatial and temporal relations among intracratonic basins, karstic terrain, and continental glaciation suggest that Pleistocene glaciation may have initiated the discharge of saline waters from the margins of these basins. Glaciation-induced discharge of saline waters could result from the consolidation of sediments due to the overlying pressure of glacial ice, and flushing of underlying aquifers as a result of bottom melting in recharge areas of basic aquifers. The upward migration of basin-derived saline waters into near-surface aquifers would result in the mixing of saline waters with infiltrating glacial meltwater and meteoric water. The development of a vertically restricted zone of mixing of saline and fresh water in limestone aquifers would result in the dissolution of limestone; this mechanism could be responsible for the formation, or at least the initiation of, some caves and associated karst features in the midcontinent region.

  8. Percutaneous Irreversible Electroporation Lung Ablation: Preliminary Results in a Porcine Model

    SciTech Connect (OSTI)

    Deodhar, Ajita [Memorial Sloan Kettering Cancer Center, Interventional Radiology and Image-Guided Therapies (United States); Monette, Sebastien [Memorial Sloan Kettering Cancer Center, Laboratory of Comparative Pathology (United States); Single, Gordon W.; Hamilton, William C. [Angiodynamics, Inc (United States); Thornton, Raymond H.; Sofocleous, Constantinos T.; Maybody, Majid; Solomon, Stephen B., E-mail: solomons@mskcc.org [Memorial Sloan Kettering Cancer Center, Interventional Radiology and Image-Guided Therapies (United States)

    2011-12-15T23:59:59.000Z

    Objective: Irreversible electroporation (IRE) uses direct electrical pulses to create permanent 'pores' in cell membranes to cause cell death. In contrast to conventional modalities, IRE has a nonthermal mechanism of action. Our objective was to study the histopathological and imaging features of IRE in normal swine lung. Materials and Methods: Eleven female swine were studied for hyperacute (8 h), acute (24 h), subacute (96 h), and chronic (3 week) effects of IRE ablation in lung. Paired unipolar IRE applicators were placed under computed tomography (CT) guidance. Some applicators were deliberately positioned near bronchovascular structures. IRE pulse delivery was synchronized with the cardiac rhythm only when ablation was performed within 2 cm of the heart. Contrast-enhanced CT scan was performed immediately before and after IRE and at 1 and 3 weeks after IRE ablation. Representative tissue was stained with hematoxylin and eosin for histopathology. Results: Twenty-five ablations were created: ten hyperacute, four acute, and three subacute ablations showed alveolar edema and necrosis with necrosis of bronchial, bronchiolar, and vascular epithelium. Bronchovascular architecture was maintained. Chronic ablations showed bronchiolitis obliterans and alveolar interstitial fibrosis. Immediate post-procedure CT images showed linear or patchy density along the applicator tract. At 1 week, there was consolidation that resolved partially or completely by 3 weeks. Pneumothorax requiring chest tube developed in two animals; no significant cardiac arrhythmias were noted. Conclusion: Our preliminary porcine study demonstrates the nonthermal and extracellular matrix sparing mechanism of action of IRE. IRE is a potential alternative to thermal ablative modalities.

  9. Drop Test Results for the Combustion Engineering Model No. ABB-2901 Fuel Pellet Package

    SciTech Connect (OSTI)

    Hafner, R S; Mok, G C; Hagler, L G

    2004-04-23T23:59:59.000Z

    The U.S. Nuclear Regulatory Commission (USNRC) contracted with the Packaging Review Group (PRG) at Lawrence Livermore National Laboratory (LLNL) to conduct a single, 30-ft shallow-angle drop test on the Combustion Engineering ABB-2901 drum-type shipping package. The purpose of the test was to determine if bolted-ring drum closures could fail during shallow-angle drops. The PRG at LLNL planned the test, and Defense Technologies Engineering Division (DTED) personnel from LLNL's Site-300 Test Group executed the plan. The test was conducted in November 2001 using the drop-tower facility at LLNL's Site 300. Two representatives from Westinghouse Electric Company in Columbia, South Carolina (WEC-SC); two USNRC staff members; and three PRG members from LLNL witnessed the preliminary test runs and the final test. The single test clearly demonstrated the vulnerability of the bolted-ring drum closure to shallow-angle drops-the test package's drum closure was easily and totally separated from the drum package. The results of the preliminary test runs and the 30-ft shallow-angle drop test offer valuable qualitative understandings of the shallow-angle impact.

  10. Star Formation in Isolated Disk Galaxies. II. Schmidt Laws and Efficiency of Gravitational Collapse

    E-Print Network [OSTI]

    Yuexing Li; Mordecai-Mark Mac Low; Ralf S. Klessen

    2006-02-21T23:59:59.000Z

    (Abridged). We model gravitational instability in a wide range of isolated disk galaxies, using GADGET, a three-dimensional, smoothed particle hydrodynamics code. The model galaxies include a dark matter halo and a disk of stars and isothermal gas. The global Schmidt law observed in disk galaxies is quantitatively reproduced by our models. We find that the surface density of star formation rate directly correlates with the strength of local gravitational instability. The local Schmidt laws of individual galaxies in our models show clear evidence of star formation thresholds. Our results suggest that the non-linear development of gravitational instability determines the local and global Schmidt laws, and the star formation thresholds.

  11. Negative feedback effects on star formation history and cosmic reionization

    E-Print Network [OSTI]

    Lei Wang; Jirong Mao; Shouping Xiang; Ye-Fei Yuan

    2008-12-22T23:59:59.000Z

    After considering the effects of negative feedback on the process of star formation, we explore the relationship between star formation process and the associated feedback, by investigating how the mechanical feedback from supernovae(SNe) and radiative feedback from luminous objects regulate the star formation rate and therefore affect the cosmic reionization.Based on our present knowledge of the negative feedback theory and some numerical simulations, we construct an analytic model in the framework of the Lambda cold dark matter model. In certain parameter regions, our model can explain some observational results properly. In large halos(T_vir>10000 K), both mechanical and radiative feedback have a similar behavior: the relative strength of negative feedback reduces as the redshift decreases. In contrast, in small halos (T_virfeedback gets stronger when the redshift decreases. And the star formation rate in these small halos depends very weakly on the star-formation efficiency. Our results show that the radiative feedback is important for the early generation stars. It can suppress the star formation rate considerably. But the mechanical feedback from the SNe explosions is not able to affect the early star formation significantly. The early star formation in small-halo objects is likely to be self-regulated. The radiative and mechanical feedback dominates the star formation rate of the PopII/I stars all along. The feedback from first generation stars is very strong and should not be neglected. However, their effects on the cosmic reionization are not significant, which results in a small contribution to the optical depth of Thomson scattering.

  12. Response of water vapor to interannual variations of SST: Results from NCAR Community Climate Model (CCM2)

    SciTech Connect (OSTI)

    Sun, De-Zheng [National Center For Atmospheric Research, Boulder, CO (United States)

    1997-11-01T23:59:59.000Z

    This paper very briefly documents the response of water vapor to interannual changes in sea surface temperature (SST) in two of the most frequently used climate models: the National Center for Atmospheric Research (NCAR) community climate model (CCM2) and the GFDL spectral model (R30). The corresponding results from radiosonde data are also presented for reference. A simple linear regression model is used to quantify the response of water vapor to changes in SST in the two simulations. Except for the negative response of water vapor over Australia, CCM2 simulates the major characteristics in the horizontal structure of the water vapor response shown in the radiosonde data. The negative response of water over Australia is also not well simulated by GFDL R30. In addition, GFDL R30 significantly underestimates the positive response over the Indian Ocean. The horizontal contrasts between the negative response over the western Pacific and the positive response over the central and eastern Pacific in the model simulations are larger than in the radiosonde data. The negative response in the subtropical region in CCM2 is more pronounced than in R30. Averaged over the tropics, CCM2 has a larger water vapor response in both the boundary layer and the upper troposphere than R30. The correlations between variations of water vapor in the upper troposphere and those at the surface level are also stronger in CCM2 than in R30. 2 refs., 5 figs.

  13. Formation of molecular hydrogen on amorphous silicate surfaces

    E-Print Network [OSTI]

    Ling Li; Giulio Manico; Emanuele Congiu; Joe Roser; Sol Swords; Hagai B. Perets; Adina Lederhendler; Ofer Biham; John Robert Brucato; Valerio Pirronello; Gianfranco Vidali

    2007-09-16T23:59:59.000Z

    Experimental results on the formation of molecular hydrogen on amorphous silicate surfaces are presented and analyzed using a rate equation model. The energy barriers for the relevant diffusion and desorption processes are obtained. They turn out to be significantly higher than those obtained for polycrystalline silicates, demonstrating the importance of grain morphology. Using these barriers we evaluate the efficiency of molecular hydrogen formation on amorphous silicate grains under interstellar conditions. It is found that unlike polycrystalline silicates, amorphous silicate grains are efficient catalysts of H_2 formation in diffuse interstellar clouds.

  14. The Formation of Primordial Luminous Objects

    E-Print Network [OSTI]

    Emanuele Ripamonti; Tom Abel

    2005-07-06T23:59:59.000Z

    In these lecture notes we review the current knowledge about the formation of the first luminous objects. We start from the cosmological context of hierarchical models of structure formation, and discuss the main physical processes which are believed to lead to primordial star formation, i.e. the cooling processes and the chemistry of molecules (especially H2) in a metal-free gas. We then describe the techniques and results of numerical simulations, which indicate that the masses of the first luminous objects are likely to be much larger than that of present-day stars. Finally, we discuss the scenario presented above, exposing some of the most interesting problems which are currently being investigated, such as that of the feedback effects of these objects.

  15. Fast Track Reservoir Modeling of Shale Formations in the Appalachian Basin. Application to Lower Huron Shale in Eastern Kentucky

    SciTech Connect (OSTI)

    Grujic, Ognjen; Mohaghegh, Shahab; Bromhal, Grant

    2010-07-01T23:59:59.000Z

    In this paper a fast track reservoir modeling and analysis of the Lower Huron Shale in Eastern Kentucky is presented. Unlike conventional reservoir simulation and modeling which is a bottom up approach (geo-cellular model to history matching) this new approach starts by attempting to build a reservoir realization from well production history (Top to Bottom), augmented by core, well-log, well-test and seismic data in order to increase accuracy. This approach requires creation of a large spatial-temporal database that is efficiently handled with state of the art Artificial Intelligence and Data Mining techniques (AI & DM), and therefore it represents an elegant integration of reservoir engineering techniques with Artificial Intelligence and Data Mining. Advantages of this new technique are a) ease of development, b) limited data requirement (as compared to reservoir simulation), and c) speed of analysis. All of the 77 wells used in this study are completed in the Lower Huron Shale and are a part of the Big Sandy Gas field in Eastern Kentucky. Most of the wells have production profiles for more than twenty years. Porosity and thickness data was acquired from the available well logs, while permeability, natural fracture network properties, and fracture aperture data was acquired through a single well history matching process that uses the FRACGEN/NFFLOW simulator package. This technology, known as Top-Down Intelligent Reservoir Modeling, starts with performing conventional reservoir engineering analysis on individual wells such as decline curve analysis and volumetric reserves estimation. Statistical techniques along with information generated from the reservoir engineering analysis contribute to an extensive spatio-temporal database of reservoir behavior. The database is used to develop a cohesive model of the field using fuzzy pattern recognition or similar techniques. The reservoir model is calibrated (history matched) with production history from the most recently drilled wells. The calibrated model is then further used for field development strategies to improve and enhance gas recovery.

  16. Mixed-mode diesel HCCI with External Mixture Formation: Preliminary...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Mixed-mode diesel HCCI with External Mixture Formation: Preliminary Results Mixed-mode diesel HCCI with External Mixture Formation: Preliminary Results 2003 DEER Conference...

  17. Validation of a blowby model using experimental results in motoring condition with the change of compression ratio and engine speed

    SciTech Connect (OSTI)

    Aghdam, E. Abdi [Department of Mechanical Engineering, University of Mohaghegh Ardabili, Ardabil (Iran); Kabir, M.M. [Department of Mechanical Engineering, University of Mohaghegh Ardabili, Ardabil (Iran); Department of Engineering, Islamic Azad University, Aliabad Katoul Branch, Golestan (Iran)

    2010-02-15T23:59:59.000Z

    Blowby and gas flow through the cylinder-piston-ring crevices are phenomena that affect the engine performance and exhaust emissions. Also these phenomena influence the cylinder pressure and temperature and the charge amount during a cycle. The study and validation of a sub-model for these phenomena in the absence of engine combustion deducts all effects arisen from the combustion event. During the current study, blowby sub-model and gas flow through crevices under motoring conditions has been noticed using a volume-orifice theory and the experimental results measured from a research engine. Blowby geometric parameters, consisting of a few critical cross-section areas (orifice areas) and volumes (top land and inter-ring crevice volumes), were measured in ambient temperature and corrected for hot running conditions. The cylinder pressure during cycle was measured by a piezoelectric pressure transducer and the low pressure parts of the cycle were measured using a piezoresistive pressure transducer for referencing purposes. The obtained results show a very good agreement between experimentally measured pressure data and model output for three compression ratios of 7.6, 10.2, 12.4 and three engine speeds of 750, 1500 and 2000 rpm, so that the maximum deviation was almost 5%. The model predicted that the maximum mass loss increased with increase of compression ratio and decreased with increase of engine speed. Also the peak mass loss position happened within the range of 3-9 CA after top dead center. After occurrence of the maximum loss, a reverse flow from the top land crevice into the cylinder was predicted in the model. (author)

  18. A Variational Model for Oligomer-Formation Process of GNNQQNY Peptide from Yeast Prion Protein Sup35

    E-Print Network [OSTI]

    Zhang, Yang

    into the highly regulated amyloid fibril structures are largely unknown. We proposed a residue-level coarse of the proposed model in understanding the general mechanism of the amyloid fibril system. INTRODUCTION Many human neurodegenerative diseases are associated with the aggregation of insoluble amyloid

  19. Modeling the formation and fate of the nearsurface temperature maximum in the Canadian Basin of the Arctic Ocean

    E-Print Network [OSTI]

    Zhang, Jinlun

    at the end of summer 2007, using both model output (described in section 2) and observed data. [3] Jackson et of the Arctic Ocean over the years 2000­2009. The NSTM is formed from local summertime absorption of solar., 2008; Nghiem et al., 2007]. This allowed 500% more solar energy into the surface layers of the Beaufort

  20. Offshore Code Comparison Collaboration within IEA Wind Task 23: Phase IV Results Regarding Floating Wind Turbine Modeling; Preprint

    SciTech Connect (OSTI)

    Jonkman, J.; Larsen, T.; Hansen, A.; Nygaard, T.; Maus, K.; Karimirad, M.; Gao, Z.; Moan, T.; Fylling, I.

    2010-04-01T23:59:59.000Z

    Offshore wind turbines are designed and analyzed using comprehensive simulation codes that account for the coupled dynamics of the wind inflow, aerodynamics, elasticity, and controls of the turbine, along with the incident waves, sea current, hydrodynamics, and foundation dynamics of the support structure. This paper describes the latest findings of the code-to-code verification activities of the Offshore Code Comparison Collaboration, which operates under Subtask 2 of the International Energy Agency Wind Task 23. In the latest phase of the project, participants used an assortment of codes to model the coupled dynamic response of a 5-MW wind turbine installed on a floating spar buoy in 320 m of water. Code predictions were compared from load-case simulations selected to test different model features. The comparisons have resulted in a greater understanding of offshore floating wind turbine dynamics and modeling techniques, and better knowledge of the validity of various approximations. The lessons learned from this exercise have improved the participants' codes, thus improving the standard of offshore wind turbine modeling.

  1. Testing models of ultra-fast India-Asia convergence : new paleomagnetic results from Ladakh, Western Himalaya

    E-Print Network [OSTI]

    Bailey, Elizabeth A

    2014-01-01T23:59:59.000Z

    Rapid India-Asia convergence has led to a major continental collision and formation of the Himalayas, the highest mountain range on Earth. Knowledge of the paleolatitude of the Kohistan-Ladakh Arc (KLA), an intermediate ...

  2. Vacuum models with a linear and a quadratic term in H: structure formation and number counts analysis

    E-Print Network [OSTI]

    Adria Gomez-Valent; Joan Sola

    2015-01-29T23:59:59.000Z

    We focus on the class of cosmological models with a time-evolving vacuum energy density of the form $\\rho_\\Lambda=C_0+C_1 H+C_2 H^2$, where $H$ is the Hubble rate. Higher powers of $H$ could be important for the early inflationary epoch, but are irrelevant afterwards. We study these models at the background level and at the perturbations level, both at the linear and at the nonlinear regime. We find that those with $C_0=0$ are seriously hampered, as they are unable to fit simultaneously the current observational data on Hubble expansion and the linear growth rate of clustering. This is in contrast to the $C_0\

  3. Actualistic and Geochemical Modeling of Reservoir Rock, CO2 and Formation Fluid Interaction, Citronelle Oil Field, Alabama

    SciTech Connect (OSTI)

    Weislogel, Amy

    2014-01-31T23:59:59.000Z

    This report includes description of the Citronelle field study area and the work carried out in the project to characterize the geology and composition of reservoir rock material and to collect an analyze the geochemical composition of produced fluid waters from the Citronelle field. Reservoir rock samples collected from well bore core were made into thin-sections and assessed for textural properties, including pore types and porosity distribution. Compositional framework grain modal data were collected via point-counting, and grain and cement mineralogy was assessed using SEM-EDS. Geochemistry of fluid samples is described and modeled using PHREEQC. Composition of rock and produced fluids were used as inputs for TOUGHREACT reactive transport modeling, which determined the rock-fluid system was in disequilibrium.

  4. Benchmark single-differential ionization cross section results for the {ital s}-wave model of electron-hydrogen scattering

    SciTech Connect (OSTI)

    Baertschy, M. [Department of Applied Science, University of California--Davis, Livermore, California 94550 (United States)] [Department of Applied Science, University of California--Davis, Livermore, California 94550 (United States); Rescigno, T.N. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Isaacs, W.A.; McCurdy, C.W. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    1999-07-01T23:59:59.000Z

    Exterior complex scaling enables one to compute the outgoing wave portion of the wave function for three charged particles without explicitly imposing the asymptotic boundary condition for three-body breakup. This technique is used in connection with a high-order finite difference scheme to provide numerically accurate single-differential ionization cross sections for the Temkin-Poet ({ital s}-wave) model of e-H scattering. These benchmark values are compared with results obtained from several recent close-coupling approaches that employ pseudostates to discretize the ionization continuum, but use a strictly two-body scattering formalism. {copyright} {ital 1999} {ital The American Physical Society}

  5. The solar photospheric abundance of hafnium and thorium. Results from CO5BOLD 3D hydrodynamic model atmospheres

    E-Print Network [OSTI]

    Elisabetta Caffau; L. Sbordone; H. -G. Ludwig; P. Bonifacio; M. Steffen; N. T. Behara

    2008-03-25T23:59:59.000Z

    Context: The stable element hafnium (Hf) and the radioactive element thorium (Th) were recently suggested as a suitable pair for radioactive dating of stars. The applicability of this elemental pair needs to be established for stellar spectroscopy. Aims: We aim at a spectroscopic determination of the abundance of Hf and Th in the solar photosphere based on a \\cobold 3D hydrodynamical model atmosphere. We put this into a wider context by investigating 3D abundance corrections for a set of G- and F-type dwarfs. Method: High-resolution, high signal-to-noise solar spectra were compared to line synthesis calculations performed on a solar CO5BOLD model. For the other atmospheres, we compared synthetic spectra of CO5BOLD 3D and associated 1D models. Results: For Hf we find a photospheric abundance A(Hf)=0.87+-0.04, in good agreement with a previous analysis, based on 1D model atmospheres. The weak Th ii 401.9 nm line constitutes the only Th abundance indicator available in the solar spectrum. It lies in the red wing of an Ni-Fe blend exhibiting a non-negligible convective asymmetry. Accounting for the asymmetry-related additional absorption, we obtain A(Th)=0.09+-0.03, consistent with the meteoritic abundance, and about 0.1 dex lower than obtained in previous photospheric abundance determinations. Conclusions: Only for the second time, to our knowledge, has am non-negligible effect of convective line asymmetries on an abundance derivation been highlighted. Three-dimensional hydrodynamical simulations should be employed to measure Th abundances in dwarfs if similar blending is present, as in the solar case. In contrast, 3D effects on Hf abundances are small in G- to mid F-type dwarfs and sub-giants, and 1D model atmospheres can be conveniently used.

  6. Alternate Thesis & Dissertation Formats Manuscript Format Guidelines

    E-Print Network [OSTI]

    Mayfield, John

    Alternate Thesis & Dissertation Formats Manuscript Format Guidelines In addition to the standard format for dissertation/thesis, the Graduate School allows for the use of an alternative format. The manuscript format refers to the use of articles and/or book chapters to replace the standard dissertation

  7. Modeling the effects of EGR and injection pressure on soot formation in a High-Speed Direct-Injection (HSDI) diesel engine using a multi-step phenomenological soot model.

    SciTech Connect (OSTI)

    Reitz, Rolf D. (University of Wisconsin); Choi, Dae; Liu, Yi. (University of Wisconsin); RempleEwert, Bret H. (University of Wisconsin); Foster, David. (University of Wisconsin); Miles, Paul; Tao, Feng (University of Wisconsin)

    2005-01-01T23:59:59.000Z

    Low-temperature combustion concepts that utilize cooled EGR, early/retarded injection, high swirl ratios, and modest compression ratios have recently received considerable attention. To understand the combustion and, in particular, the soot formation process under these operating conditions, a modeling study was carried out using the KIVA-3V code with an improved phenomenological soot model. This multi-step soot model includes particle inception, surface growth, surface oxidation, and particle coagulation. Additional models include a piston-ring crevice model, the KH/RT spray breakup model, a droplet wall impingement model, a wall heat transfer model, and the RNG k-{var_epsilon} turbulence model. The Shell model was used to simulate the ignition process, and a laminar-and-turbulent characteristic time combustion model was used for the post-ignition combustion process. A low-load (IMEP=3 bar) operating condition was considered and the predicted in-cylinder pressures and heat release rates were compared with measurements. Predicted soot mass, soot particle size, soot number density distributions and other relevant quantities are presented and discussed. The effects of variable EGR rate (0-68%), injection pressure (600-1200 bar), and injection timing were studied. The predictions demonstrate that both EGR and retarded injection are beneficial for reducing NO{sub x} emissions, although the former has a more pronounced effect. Additionally, higher soot emissions are typically predicted for the higher EGR rates. However, when the EGR rate exceeds a critical value (over 65% in this study), the soot emissions decrease. Reduced soot emissions are also predicted when higher injection pressures or retarded injection timings are employed. The reduction in soot with retarded injection is less than what is observed experimentally, however.

  8. Productivity, detritus formation and grazing of the seagrass Thalassia testudinum Banks in Caribbean meadows: a simulative numerical model

    E-Print Network [OSTI]

    Victoria-Rueda, Carlos Humberto

    1981-01-01T23:59:59.000Z

    ). The amount of organic carbon yield by the leaves of Thalassia compares well, and in many cases surpasses, average values reported for tropical rain forest and reef ecosystems and intensively cultivated agroecosystems such as hybrid corn, rice... course of my graduate studies. I extend my grat1tude to Dr, Rezneat Darnell, co-chairman of the committee, who initiated my interest in the top1c of ecosystem modeling. His constructive crit1cism and contr1bution to this work is fully appreciated. I...

  9. NSTX Disruption Simulations of Detailed Divertor and Passive Plate Models by Vector Potential Transfer from OPERA Global Analysis Results

    SciTech Connect (OSTI)

    P. H. Titus, S. Avasaralla, A.Brooks, R. Hatcher

    2010-09-22T23:59:59.000Z

    The National Spherical Torus Experiment (NSTX) project is planning upgrades to the toroidal field, plasma current and pulse length. This involves the replacement of the center-stack, including the inner legs of the TF, OH, and inner PF coils. A second neutral beam will also be added. The increased performance of the upgrade requires qualification of the remaining components including the vessel, passive plates, and divertor for higher disruption loads. The hardware needing qualification is more complex than is typically accessible by large scale electromagnetic (EM) simulations of the plasma disruptions. The usual method is to include simplified representations of components in the large EM models and attempt to extract forces to apply to more detailed models. This paper describes a more efficient approach of combining comprehensive modeling of the plasma and tokamak conducting structures, using the 2D OPERA code, with much more detailed treatment of individual components using ANSYS electromagnetic (EM) and mechanical analysis. This capture local eddy currents and resulting loads in complex details, and allows efficient non-linear, and dynamic structural analyses.

  10. Health effects models for nuclear power plant accident consequence analysis: Modifications of models resulting from recent reports on health effects of ionizing radiation

    SciTech Connect (OSTI)

    Abrahamson, S. (Wisconsin Univ., Madison, WI (United States)); Bender, M.A. (Brookhaven National Lab., Upton, NY (United States)); Boecker, B.B.; Scott, B.R. (Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States). Inhalation Toxicology Research Inst.); Gilbert, E.S. (Pacific Northwest Lab., Richland, WA (United States))

    1991-08-01T23:59:59.000Z

    The Nuclear Regulatory Commission has sponsored several studies to identify and quantify the potential health effects of accidental releases of radionuclides from nuclear power plants. The most recent health effects models resulting from these efforts were published in two reports, NUREG/CR-4214, Rev. 1, Part 1 (1990) and Part 2 (1989). Several major health effects reports have been published recently that may impact the health effects models presented in these reports. This addendum to the Part 2 (1989) report, provides a review of the 1986 and 1988 reports by the United Nations Scientific Committee on the Effects of Atomic Radiation, the National Academy of Sciences/National Research Council BEAR 5 Committee report and Publication 60 of the International Commission on Radiological Protection as they relate to this report. The three main sections of this addendum discuss early occurring and continuing effects, late somatic effects, and genetic effects. The major changes to the NUREG/CR-4214 health effects models recommended in this addendum are for late somatic effects. These changes reflect recent changes in cancer risk factors that have come from longer followup and revised dosimetry in major studies like that on the Japanese A-bomb survivors. The results presented in this addendum should be used with the basic NUREG/CR-4214 reports listed above to obtain the most recent views on the potential health effects of radionuclides released accidentally from nuclear power plants. 48 refs., 4 figs., 24 tabs.

  11. Result Summary for the Area 5 Radioactive Waste Management Site Performance Assessment Model Version 4.110

    SciTech Connect (OSTI)

    NSTec Environmental Management

    2011-07-20T23:59:59.000Z

    Results for Version 4.110 of the Area 5 Radioactive Waste Management Site (RWMS) performance assessment (PA) model are summarized. Version 4.110 includes the fiscal year (FY) 2010 inventory estimate, including a future inventory estimate. Version 4.110 was implemented in GoldSim 10.11(SP4). The following changes have been implemented since the last baseline model, Version 4.105: (1) Updated the inventory and disposal unit configurations with data through the end of FY 2010. (1) Implemented Federal Guidance Report 13 Supplemental CD dose conversion factors (U.S. Environmental Protection Agency, 1999). Version 4.110 PA results comply with air pathway and all-pathways annual total effective dose (TED) performance objectives (Tables 2 and 3, Figures 1 and 2). Air pathways results decrease moderately for all scenarios. The time of the maximum for the air pathway open rangeland scenario shifts from 1,000 to 100 years (y). All-pathways annual TED increases for all scenarios except the resident scenario. The maximum member of public all-pathways dose occurs at 1,000 y for the resident farmer scenario. The resident farmer dose was predominantly due to technetium-99 (Tc-99) (82 percent) and lead-210 (Pb-210) (13 percent). Pb-210 present at 1,000 y is produced predominantly by radioactive decay of uranium-234 (U-234) present at the time of disposal. All results for the postdrilling and intruder-agriculture scenarios comply with the performance objectives (Tables 4 and 5, Figures 3 and 4). The postdrilling intruder results are similar to Version 4.105 results. The intruder-agriculture results are similar to Version 4.105, except for the Pit 6 Radium Disposal Unit (RaDU). The intruder-agriculture result for the Shallow Land Burial (SLB) disposal units is a significant fraction of the performance objective and exceeds the performance objective at the 95th percentile. The intruder-agriculture dose is due predominantly to Tc-99 (75 percent) and U-238 (9.5 percent). The acute intruder scenario results comply with all performance objectives (Tables 6 and 7, Figures 5 and 6). The acute construction result for the SLB disposal units decreases significantly with this version. The maximum acute intruder dose occurs at 1,000 y for the SLB disposal units under the acute construction scenario. The acute intruder dose is caused by multiple radionuclides including U-238 (31 percent), Th-229 (28 percent), plutonium-239 (8.6 percent), U-233 (7.8 percent), and U-234 (6.7 percent). All results for radon-222 (Rn-222) flux density comply with the performance objective (Table 8, Figure 7). The mean Pit 13 RaDU flux density is close to the 0.74 Bq m{sup -2} s{sup -1} limit.

  12. Reconstructing the Star Formation Histories of Galaxies

    E-Print Network [OSTI]

    Uta Fritze; Thomas Lilly

    2007-01-15T23:59:59.000Z

    We present a methodological study to find out how far back and to what precision star formation histories of galaxies can be reconstructed from CMDs, from integrated spectra and Lick indices, and from integrated multi-band photometry. Our evolutionary synthesis models GALEV allow to describe the evolution of galaxies in terms of all three approaches and we have assumed typical observational uncertainties for each of them and then investigated to what extent and accuracy different star formation histories can be discriminated. For a field in the LMC bar region with both a deep CMD from HST observations and a trailing slit spectrum across exactly the same field of view we could test our modelling results against real data.

  13. Atomic Level Green-Kubo Stress Correlation Function for a Model Crystal: An Insight into Molecular Dynamics Results on a Model Liquid

    E-Print Network [OSTI]

    V. A. Levashov

    2014-06-23T23:59:59.000Z

    In order to get insight into the connection between the vibrational dynamics and the atomic level Green-Kubo stress correlation function in liquids we consider this connection in a model crystal instead. Of course, vibrational dynamics in liquids and crystals are quite different and it is not expected that the results obtained on a model crystal should be valid for liquids. However, these considerations provide a benchmark to which the results of the previous molecular dynamics simulations can be compared. Thus, assuming that vibrations are plane waves, we derive analytical expressions for the atomic level stress correlation functions in the classical limit and analyze them. These results provide, in particular, a recipe for analysis of the atomic level stress correlation functions in Fourier space and extraction of the wavevector and frequency dependent information. We also evaluate the energies of the atomic level stresses. Obtained energies are significantly smaller than the energies that were obtained in MD simulations of liquids previously. This result suggests that the average energies of the atomic level stresses in liquids and glasses are largely determined by the structural disorder. We discuss this result in the context of equipartition of the atomic level stress energies. Analysis of the previously published data suggests that it is possible to speak about configurational and vibrational contributions to the average energies of the atomic level stresses in a glass state. However, this separation in a liquid state is problematic. We also consider peak broadening in the pair distribution function with increase of distance. We find that peak broadening (by ~40%) occurs due to the transverse vibrational modes, while contribution from the longitudinal modes does not change with distance. Finally, we introduce and consider atomic level transverse current correlation function.

  14. Method of fracturing a geological formation

    DOE Patents [OSTI]

    Johnson, James O. (2679-B Walnut, Los Alamos, NM 87544)

    1990-01-01T23:59:59.000Z

    An improved method of fracturing a geological formation surrounding a well bore is disclosed. A relatively small explosive charge is emplaced in a well bore and the bore is subsequently hydraulically pressurized to a pressure less than the formation breakdown pressure and preferably greater than the fracture propagation pressure of the formation. The charge is denoted while the bore is so pressurized, resulting in the formation of multiple fractures in the surrounding formation with little or no accompanying formation damage. Subsequent hydraulic pressurization can be used to propagate and extend the fractures in a conventional manner. The method is useful for stimulating production of oil, gas and possibly water from suitable geologic formations.

  15. Star Formation and Galaxy Environment

    E-Print Network [OSTI]

    H. K. C. Yee

    2000-04-05T23:59:59.000Z

    The dependence of star formation rate on galaxian environment is a key issue in the understanding of galaxy formation and evolution. However, the study of this subject is complex and observationally challenging. This paper reviews some of the current results, drawing mostly from recent large redshift surveys such the LCRS, the MORPH collaboration, and the CNOC1 and CNOC2 redshift surveys.

  16. SISGR - In situ characterization and modeling of formation reactions under extreme heating rates in nanostructured multilayer foils

    SciTech Connect (OSTI)

    Hufnagel, Todd C.

    2014-06-09T23:59:59.000Z

    Materials subjected to extreme conditions, such as very rapid heating, behave differently than materials under more ordinary conditions. In this program we examined the effect of rapid heating on solid-state chemical reactions in metallic materials. One primary goal was to develop experimental techniques capable of observing these reactions, which can occur at heating rates in excess of one million degrees Celsius per second. One approach that we used is x-ray diffraction performed using microfocused x-ray beams and very fast x-ray detectors. A second approach is the use of a pulsed electron source for dynamic transmission electron microscopy. With these techniques we were able to observe how the heating rate affects the chemical reaction, from which we were able to discern general principles about how these reactions proceed. A second thrust of this program was to develop computational tools to help us understand and predict the reactions. From atomic-scale simulations were learned about the interdiffusion between different metals at high heating rates, and about how new crystalline phases form. A second class of computational models allow us to predict the shape of the reaction front that occurs in these materials, and to connect our understanding of interdiffusion from the atomistic simulations to measurements made in the laboratory. Both the experimental and computational techniques developed in this program are expected to be broadly applicable to a wider range of scientific problems than the intermetallic solid-state reactions studied here. For example, we have already begun using the x-ray techniques to study how materials respond to mechanical deformation at very high rates.

  17. Methodology and results of the impacts of modeling electric utilities ; a comparative evaluation of MEMM and REM

    E-Print Network [OSTI]

    Baughman, Martin L.

    1981-01-01T23:59:59.000Z

    This study compares two models of the U.S. electric utility industry including the EIA's electric utility submodel in the Midterm Energy Market Model (MEMM), and the Baughman-Joskow Regionalized Electricity Model (REM). ...

  18. -Preliminary results from temperature modeling using the CIII 97.7 nm / CIV 155 nm line ratio give

    E-Print Network [OSTI]

    Cohen, David

    reconnection). - Temperatures for single-spheromak shots (during which no reconnection took place) were. Introduction - The Swarthmore Spheromak Experiment (SSX) studies magnetic reconnection during the merging of two spheromaks: Figure 1. Schematic of spheromak formation in SSX. (a) Hydrogen gas is pumped

  19. Habitability of Earth-like planets with high obliquity and eccentric orbits: results from a general circulation model

    E-Print Network [OSTI]

    Linsenmeier, Manuel; Lucarini, Valerio

    2014-01-01T23:59:59.000Z

    We explore the implications of seasonal variability for the habitability of Earth-like planets as determined by the two parameters polar obliquity and orbital eccentricity. Commonly, the outer boundary of the habitable zone (HZ) is set by a completely frozen planet, or snowball state. Using a general circulation model coupled to a thermodynamic sea-ice model, our results show that seasonal variability can extend this outer limit of the HZ from 1.03 AU (no seasonal variability) to a maximum of 1.69 AU. Also the multistability property of planets close to the outer edge of the HZ is influenced by seasonal variability. Cold states extend far into the HZ for non-oblique planets. On highly oblique planets, cold states can also allow for habitable regions, which highlights the sufficient but not necessary condition of a warm climate state for habitability. While the effect of obliquity on the extent of the HZ is comparatively small on circular orbits, it becomes highly relevant on eccentric orbits. Our experiments ...

  20. Dimensionality effects in Turing pattern formation

    E-Print Network [OSTI]

    Teemu Leppanen; Mikko Karttunen; Kimmo Kaski; Rafael A. Barrio

    2003-06-05T23:59:59.000Z

    The problem of morphogenesis and Turing instability are revisited from the point of view of dimensionality effects. First the linear analysis of a generic Turing model is elaborated to the case of multiple stationary states, which may lead the system to bistability. The difference between two- and three-dimensional pattern formation with respect to pattern selection and robustness is discussed. Preliminary results concerning the transition between quasi-two-dimensional and three-dimensional structures are presented and their relation to experimental results are addressed.

  1. Bistability in a self-assembling system confined by elastic walls. Exact results in a one-dimensional lattice model

    E-Print Network [OSTI]

    Jakub P?kalski; Alina Ciach; Noé G. Almarza

    2014-11-14T23:59:59.000Z

    The impact of confinement on self-assembly of particles interacting with short-range attraction and long-range repulsion (SALR) potential is studied for thermodynamic states corresponding to local ordering of clusters or layers in the bulk. Exact and asymptotic expressions for the local density and for the effective potential between the confining surfaces are obtained for a one-dimensional lattice model introduced in [J. P\\k{e}kalski et al. $J. Chem. Phys.$ ${\\bf 140}$, 144903 (2013)].The simple asymptotic formulas are shown to be in good quantitative agreement with exact results for slits containing at least 5 layers. We observe that the incommensurability of the system size and the average distance between the clusters or layers in the bulk leads to structural deformations that are different for different values of the chemical potential $\\mu$. The change of the type of defects is reflected in the dependence of density on $\\mu$ that has a shape characteristic for phase transitions. Our results may help to avoid misinterpretation of the change of the type of defects as a phase transition in simulations of inhomogeneous systems. Finally, we show that a system confined by soft elastic walls may exhibit bistability such that two system sizes that differ approximately by the average distance between the clusters or layers are almost equally probable. This may happen when the equilibrium separation between the soft boundaries of an empty slit corresponds to the largest stress in the confined self-assembling system.

  2. A quantitative model of trading and price formation in nancial markets Marcus G. Daniels, 1 J. Doyne Farmer, 1 L aszl o Gillemot, 1 Giulia Iori, 2 and Eric Smith 1

    E-Print Network [OSTI]

    A quantitative model of trading and price formation in #12;nancial markets Marcus G. Daniels, 1 J of prices, which is the standard measure of #12;nancial risk, and the spread and price impact functions, which are the main determinants of transaction cost. Guided by dimensional analysis, simulation

  3. Physical regimes for feedback in galaxy formation

    E-Print Network [OSTI]

    P. Monaco

    2004-04-13T23:59:59.000Z

    We present a new (semi-)analytic model for feedback in galaxy formation. The ISM is modeled as a two-phase medium in pressure equilibrium. The remnants of exploding type II SNe percolate into super-bubbles (SBs) that sweep the ISM, heating the hot phase (if the SB is adiabatic) or cooling it (in the snowplow stage, when the interior gas of the SB has cooled). The resulting feedback regimes occur in well-defined regions of the space defined by vertical scale-length and surface density of the structure. When SBs blow out in the adiabatic regime, the efficiency of SNe in heating the ISM is ~5 per cent, with \\~80 per cent of the energy budget injected into the external halo, and the outcoming ISM is self-regulated to a state similar to that found in the Milky Way. Feedback is most efficient when SBs are pressure-confined in the adiabatic regime. In some significant regions of the parameter space confinement takes place in the snowplow stage; then the hot phase has a lower temperature and star formation is quicker. In some critical cases, the hot phase is strongly depleted and the cold phase percolates the whole volume, giving rise to a sudden burst of star formation. Strong galactic winds are predicted to happen only in critical cases. This model provides a starting point for constructing a realistic grid of feedback solutions to be used in galaxy formation codes. The predictive power of this model extends to many properties of the ISM, so that most parameters can be constrained by reproducing the main properties of the Milky Way. (Abridged)

  4. Star Formation in the Multiverse

    E-Print Network [OSTI]

    Raphael Bousso; Stefan Leichenauer

    2008-10-17T23:59:59.000Z

    We develop a simple semi-analytic model of the star formation rate (SFR) as a function of time. We estimate the SFR for a wide range of values of the cosmological constant, spatial curvature, and primordial density contrast. Our model can predict such parameters in the multiverse, if the underlying theory landscape and the cosmological measure are known.

  5. Petrographic characterization of Kentucky coals. Final report. Part IV. A petrographic and chemical model for the evolution of the Tradewater Formation coals in Western Kentucky

    SciTech Connect (OSTI)

    Graese, A.M.; Hower, J.C.; Ferm, J.C.

    1984-01-01T23:59:59.000Z

    A depositional model for the coals of the Tradewater Formation and associated rock units was constructed as a predictive device for the occurrence of economically important low sulfur coal. Twenty-one cores were examined and ninety-eight coal samples were analyzed for maceral, ash, and sulfur contents. These data were then analyzed to determine regional variation as well as vertical variation in single coal columns. Core data indicate that the majority of the Tradewater rocks consist of irregularly distributed, coarsening-upward, fine-grained detrital material which was deposited in shallow bodies of water. Minor fossiliferous shales and limestones suggest a marine influence. Less common coarse-grained, fining-upward sequences appear to be deposits of meandering channels. Like the detrital rocks, the coal seams are also irregularly distributed and exhibit variable petrographic and chemical properties reflecting changes in the Eh and pH of the coal swamp waters as well as detrital influx into the swamps. These swamps were relatively limited in extent and probably occupied the upper reaches of the tidal zone. The lack of significant stratigraphic and geographic trends in the regional data suggests that this mode of deposition was widespread and continued for a long period of time. 42 references, 19 figures, 9 tables.

  6. Preliminary Model Comparison Results From the Sim-SEQ Project Using TOUGH2, STOMP, Eclipse, and VESA Approach

    SciTech Connect (OSTI)

    Mukhopadhyay, Sumit; Doughty, Christine A.; Bacon, Diana H.; Bacci, Giacomo; Govindan, Rajesh; Shi, Ji-Quan; Gasda, Sarah E.; Ramanathan, Ramya; Nicot, Jean-Philippe; Hosseini, Seyyed; Birkholzer, Jens

    2013-11-01T23:59:59.000Z

    Sim-SEQ is an international initiative on model comparison for geologic carbon sequestration (GCS), with an objective to understand and, if possible, quantify model uncertainties. Model comparison efforts in Sim-SEQ are initially limited to one specific field test site, hereafter referred to as the Sim-SEQ Study site (or S-3 site). Within Sim-SEQ, different modeling teams are developing conceptual models of CO2 injection at the S-3 site. One of the conceptual models, developed by the LBNL team, is based on TOUGH2/EOS7C. In this paper, we present some preliminary model predictions of the S-3 site using the TOUGH2/EOS7C simulator. We also compare the predictions of the TOUGH2 simulator with three other conceptual models, developed by three different organizations, of the S-3 site.

  7. Ice Formation in Arctic Mixed-Phase Clouds: Insights from a 3-D Cloud-Resolving Model with Size-Resolved Aerosol and Cloud Microphysics

    SciTech Connect (OSTI)

    Fan, Jiwen; Ovtchinnikov, Mikhail; Comstock, Jennifer M.; McFarlane, Sally A.; Khain, Alexander

    2009-02-27T23:59:59.000Z

    The single-layer mixed-phase clouds observed during the Atmospheric Radiation Measurement (ARM) program’s Mixed-Phase Arctic Cloud Experiment (MPACE) are simulated with a 3-dimensional cloud-resolving model the System for Atmospheric Modeling (SAM) coupled with an explicit bin microphysics scheme and a radar-lidar simulator. Two possible ice enhancement mechanisms – activation of droplet evaporation residues by condensation-followed-by-freezing and droplet freezing by contact freezing inside-out, are scrutinized by extensive comparisons with aircraft and radar and lidar measurements. The locations of ice initiation associated with each mechanism and the role of ice nuclei (IN) in the evolution of mixed-phase clouds are mainly addressed. Simulations with either mechanism agree well with the in-situ and remote sensing measurements on ice microphysical properties but liquid water content is slightly underpredicted. These two mechanisms give very similar cloud microphysical, macrophysical, dynamical, and radiative properties, although the ice nucleation properties (rate, frequency and location) are completely different. Ice nucleation from activation of evaporation nuclei is most efficient near cloud top areas concentrated on the edges of updrafts, while ice initiation from the drop freezing process has no significant location preference (occurs anywhere that droplet evaporation is significant). Both enhanced nucleation mechanisms contribute dramatically to ice formation with ice particle concentration of 10-15 times higher relative to the simulation without either of them. The contribution of ice nuclei (IN) recycling from ice particle evaporation to IN and ice particle concentration is found to be very significant in this case. Cloud can be very sensitive to IN initially and form a nonquilibrium transition condition, but become much less sensitive as cloud evolves to a steady mixed-phase condition. The parameterization of Meyers et al. [1992] with the observed MPACE IN concentration is able to predict the observed mixed-phase clouds reasonably well. This validation may facilitate the application of this parameterization in the cloud and climate models to simulate Arctic clouds.

  8. The Multi-Stage Investment Timing Game in Offshore Petroleum Production: Preliminary results from an econometric model

    E-Print Network [OSTI]

    Lin, C.-Y. Cynthia

    2007-01-01T23:59:59.000Z

    me to understand the geology of oil production. ShelbyGeology or economics? Testing models of irreversible investment using North Sea oil

  9. Formation of Carbon Dwarfs

    E-Print Network [OSTI]

    Charles L. Steinhardt; Dimitar D. Sasselov

    2012-01-27T23:59:59.000Z

    We consider the formation of dwarf carbon stars via accretion from a carbon AGB companion in light of the new 107 object sample of Downes et al. (2004). This sample is now large enough to allow good mass determination via comparison of a composite spectrum to theoretical atmospheric models. Carbon dwarfs of spectral type M are indeed main sequence M dwarfs with enhanced metallicity and carbon abundance. We also calculate the predicted abundance of both M and of F/G carbon dwarfs, and show that the latter should be falsifiable in the near future.

  10. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect (OSTI)

    Ernest A. Mancini

    2002-09-25T23:59:59.000Z

    The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 2 of the project has been reservoir characterization, 3-D modeling and technology transfer. This effort has included six tasks: (1) the study of rockfluid interactions, (2) petrophysical and engineering characterization, (3) data integration, (4) 3-D geologic modeling, (5) 3-D reservoir simulation and (6) technology transfer. This work was scheduled for completion in Year 2. Overall, the project work is on schedule. Geoscientific reservoir characterization is essentially completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions is near completion. Observations regarding the diagenetic processes influencing pore system development and heterogeneity in these reef and shoal reservoirs have been made. Petrophysical and engineering property characterization has been essentially completed. Porosity and permeability data at Appleton and Vocation Fields have been analyzed, and well performance analysis has been conducted. Data integration is up to date, in that, the geological, geophysical, petrophysical and engineering data collected to date for Appleton and Vocation Fields have been compiled into a fieldwide digital database. 3-D geologic modeling of the structures and reservoirs at Appleton and Vocation Fields has been completed. The model represents an integration of geological, petrophysical and seismic data. 3-D reservoir simulation of the reservoirs at Appleton and Vocation Fields has been completed. The 3-D geologic model served as the framework for the simulations. A technology workshop on reservoir characterization and modeling at Appleton and Vocation Fields was conducted to transfer the results of the project to the petroleum industry.

  11. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect (OSTI)

    Ernest A. Mancini

    2003-09-25T23:59:59.000Z

    The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling that utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 3 of the project has been reservoir characterization, 3-D modeling, testing of the geologic-engineering model, and technology transfer. This effort has included six tasks: (1) the study of seismic attributes, (2) petrophysical characterization, (3) data integration, (4) the building of the geologic-engineering model, (5) the testing of the geologic-engineering model and (6) technology transfer. This work was scheduled for completion in Year 3. Progress on the project is as follows: geoscientific reservoir characterization is completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions has been completed. Observations regarding the diagenetic processes influencing pore system development and heterogeneity in these reef and shoal reservoirs have been made. Petrophysical and engineering property characterization has been completed. Porosity and permeability data at Appleton and Vocation Fields have been analyzed, and well performance analysis has been conducted. Data integration is up to date, in that, the geological, geophysical, petrophysical and engineering data collected to date for Appleton and Vocation Fields have been compiled into a fieldwide digital database. 3-D geologic modeling of the structures and reservoirs at Appleton and Vocation Fields has been completed. The models represent an integration of geological, petrophysical and seismic data. 3-D reservoir simulation of the reservoirs at Appleton and Vocation Fields has been completed. The 3-D geologic models served as the framework for the simulations. The geologic-engineering models of the Appleton and Vocation Field reservoirs have been developed. These models are being tested. The geophysical interpretation for the paleotopographic feature being tested has been made, and the study of the data resulting from drilling of a well on this paleohigh is in progress. Numerous presentations on reservoir characterization and modeling at Appleton and Vocation Fields have been made at professional meetings and conferences and a short course on microbial reservoir characterization and modeling based on these fields has been prepared.

  12. (Non) formation of methanol by direct hydrogenation of formate...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (Non) formation of methanol by direct hydrogenation of formate on copper catalysts. (Non) formation of methanol by direct hydrogenation of formate on copper catalysts. Abstract: We...

  13. aerosol particle formation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    1. Introduction 2 Current models tend to under-predict secondary organic aerosol (SOA Weber, Rodney 3 Modeling particle formation during low-pressure silane oxidation: Detailed...

  14. Using MiniBooNE NCEL and CCQE cross section results to constrain 3+1 sterile neutrino models

    E-Print Network [OSTI]

    Callum Wilkinson; Susan Cartwright; Lee Thompson

    2014-12-01T23:59:59.000Z

    The MiniBooNE NCEL and CCQE cross-section measurements (neutrino running) are used to set limits in the $\\Delta m^{2}-\\sin^{2}\\vartheta_{\\mu s}$ plane for a 3+1 sterile neutrino model with a mass splitting $0.1 \\leq \\Delta m^{2} \\leq 10.0$ eV$^{2}$. GENIE is used, with a relativistic Fermi gas model, to relate $E_{\

  15. Assessment of effectiveness of geologic isolation systems. Geologic-simulation model for a hypothetical site in the Columbia Plateau. Volume 2: results

    SciTech Connect (OSTI)

    Foley, M.G.; Petrie, G.M.; Baldwin, A.J.; Craig, R.G.

    1982-06-01T23:59:59.000Z

    This report contains the input data and computer results for the Geologic Simulation Model. This model is described in detail in the following report: Petrie, G.M., et. al. 1981. Geologic Simulation Model for a Hypothetical Site in the Columbia Plateau, Pacific Northwest Laboratory, Richland, Washington. The Geologic Simulation Model is a quasi-deterministic process-response model which simulates, for a million years into the future, the development of the geologic and hydrologic systems of the ground-water basin containing the Pasco Basin. Effects of natural processes on the ground-water hydrologic system are modeled principally by rate equations. The combined effects and synergistic interactions of different processes are approximated by linear superposition of their effects during discrete time intervals in a stepwise-integration approach.

  16. Comparison of a One-Dimensional Model of a High-Temperature Solid-Oxide Electrolysis Stack with CFD and Experimental Results

    SciTech Connect (OSTI)

    J. E. O'Brien; C. M. Stoots; G. L. Hawkes

    2005-11-01T23:59:59.000Z

    A one-dimensional model has been developed to predict the thermal and electrochemical behavior of a high-temperature steam electrolysis stack. This electrolyzer model allows for the determination of the average Nernst potential, cell operating voltage, gas outlet temperatures, and electrolyzer efficiency for any specified inlet gas flow rates, current density, cell active area, and external heat loss or gain. The model includes a temperature-dependent area-specific resistance (ASR) that accounts for the significant increase in electrolyte ionic conductivity that occurs with increasing temperature. Model predictions are shown to compare favorably with results obtained from a fully 3-D computational fluid dynamics model. The one-dimensional model was also employed to demonstrate the expected trends in electrolyzer performance over a range of operating conditions including isothermal, adiabatic, constant steam utilization, constant flow rate, and the effects of operating temperature.

  17. Deformed shell model results for neutrinoless double beta decay of nuclei in A=60-90 region

    E-Print Network [OSTI]

    R. Sahu; V. K. B. Kota

    2015-03-20T23:59:59.000Z

    Nuclear transition matrix elements (NTME) for the neutrinoless double beta decay of $^{70}$Zn, $^{80}$Se and $^{82}$Se nuclei are calculated within the framework of the deformed shell model based on Hartree-Fock states. For $^{70}$Zn, jj44b interaction in $^{2}p_{3/2}$, $^{1}f_{5/2}$, $^{2}p_{1/2}$ and $^{1}g_{9/2}$ space with $^{56}$Ni as the core is employed. However, for $^{80}$Se and $^{82}$Se nuclei, a modified Kuo interaction with the above core and model space are employed. Most of our calculations in this region were performed with this effective interaction. However, jj44b interaction has been found to be better for $^{70}$Zn. The above model space was used in many recent shell model and interacting boson model calculations for nuclei in this region. After ensuring that DSM gives good description of the spectroscopic properties of low-lying levels in these three nuclei considered, the NTME are calculated. The deduced half-lives with these NTME, assuming neutrino mass is 1 eV, are $1.1 \\times 10^{26}$ yr, $2.3 \\times 10^{27}$ yr and $2.2 \\times 10^{24}$ yr for $^{70}$Zn, $^{80}$Se and $^{82}$Se, respectively.

  18. Carbon-nitrogen interactions regulate climate-carbon cycle feedbacks: results from an atmosphere-ocean general circulation model

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    2009 P. E. Thornton et al. : Carbon-nitrogen interactionsregulate climate-carbon cycle feedbacks Monfray, P. ,T. H. : A global ocean carbon climatology: Results from

  19. Determination of High-Frequency Current Distribution Using EMTP-Based Transmission Line Models with Resulting Radiated Electromagnetic Fields

    SciTech Connect (OSTI)

    Mork, B; Nelson, R; Kirkendall, B; Stenvig, N

    2009-11-30T23:59:59.000Z

    Application of BPL technologies to existing overhead high-voltage power lines would benefit greatly from improved simulation tools capable of predicting performance - such as the electromagnetic fields radiated from such lines. Existing EMTP-based frequency-dependent line models are attractive since their parameters are derived from physical design dimensions which are easily obtained. However, to calculate the radiated electromagnetic fields, detailed current distributions need to be determined. This paper presents a method of using EMTP line models to determine the current distribution on the lines, as well as a technique for using these current distributions to determine the radiated electromagnetic fields.

  20. Warped DGP model in warm intermediate inflation with a general dissipative coefficient in light of BICEP2 and Planck results

    E-Print Network [OSTI]

    Ramon Herrera; Nelson Videla; Marco Olivares

    2014-10-14T23:59:59.000Z

    A warm inflationary universe scenario on a warped Dvali-Gabadadze-Porrati brane during intermediate inflation is studied. We consider a general form for the dissipative coefficient $\\Gamma(T,\\phi)\\propto T^{m}/\\phi^{m-1}$, and also study this model in the weak and strong dissipative regimes. We analyze the evolution of the universe in the slow-roll approximation, and find the exact solutions to the equations of motion. In both regimes, we utilize recent data from the BICEP2 experiment and also from the Planck satellite to constrain the parameters in our model in accordance with the theory of cosmological perturbations.

  1. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect (OSTI)

    Ernest A. Mancini

    2004-02-25T23:59:59.000Z

    The University of Alabama, in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company, has undertaken an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary goal of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. Geoscientific reservoir property, geophysical seismic attribute, petrophysical property, and engineering property characterization has shown that reef (thrombolite) and shoal reservoir lithofacies developed on the flanks of high-relief crystalline basement paleohighs (Vocation Field example) and on the crest and flanks of low-relief crystalline basement paleohighs (Appleton Field example). The reef thrombolite lithofacies have higher reservoir quality than the shoal lithofacies due to overall higher permeabilities and greater interconnectivity. Thrombolite dolostone flow units, which are dominated by dolomite intercrystalline and vuggy pores, are characterized by a pore system comprised of a higher percentage of large-sized pores and larger pore throats. Rock-fluid interactions (diagenesis) studies have shown that although the primary control on reservoir architecture and geographic distribution of Smackover reservoirs is the fabric and texture of the depositional lithofacies, diagenesis (chiefly dolomitization) is a significant factor that preserves and enhances reservoir quality. The evaporative pumping mechanism is favored to explain the dolomitization of the thrombolite doloboundstone and dolostone reservoir flow units at Appleton and Vocation Fields. Geologic modeling, reservoir simulation, and the testing and applying the resulting integrated geologic-engineering models have shown that little oil remains to be recovered at Appleton Field and a significant amount of oil remains to be recovered at Vocation Field through a strategic infill drilling program. The drive mechanisms for primary production in Appleton and Vocation Fields remain effective; therefore, the initiation of a pressure maintenance program or enhanced recovery project is not required at this time. The integrated geologic-engineering model developed for a low-relief paleohigh (Appleton Field) was tested for three scenarios involving the variables of present-day structural elevation and the presence/absence of potential reef thrombolite lithofacies. In each case, the predictions based upon the model were correct. From this modeling, the characteristics of the ideal prospect in the basement ridge play include a low-relief paleohigh associated with dendroidal/chaotic thrombolite doloboundstone and dolostone that has sufficient present-day structural relief so that these carbonates rest above the oil-water contact. Such a prospect was identified from the modeling, and it is located northwest of well Permit No. 3854B (Appleton Field) and south of well No. Permit No.11030B (Northwest Appleton Field).

  2. Earth and Terrestrial Planet Formation

    E-Print Network [OSTI]

    Jacobson, Seth A

    2015-01-01T23:59:59.000Z

    The growth and composition of Earth is a direct consequence of planet formation throughout the Solar System. We discuss the known history of the Solar System, the proposed stages of growth and how the early stages of planet formation may be dominated by pebble growth processes. Pebbles are small bodies whose strong interactions with the nebula gas lead to remarkable new accretion mechanisms for the formation of planetesimals and the growth of planetary embryos. Many of the popular models for the later stages of planet formation are presented. The classical models with the giant planets on fixed orbits are not consistent with the known history of the Solar System, fail to create a high Earth/Mars mass ratio, and, in many cases, are also internally inconsistent. The successful Grand Tack model creates a small Mars, a wet Earth, a realistic asteroid belt and the mass-orbit structure of the terrestrial planets. In the Grand Tack scenario, growth curves for Earth most closely match a Weibull model. The feeding zon...

  3. VEHICLE NETWORKS: ACHIEVING REGULAR FORMATION

    E-Print Network [OSTI]

    VEHICLE NETWORKS: ACHIEVING REGULAR FORMATION MADALENA CHAVES, ROBERT DAY, LUCIA GOMEZ a network of vehicles exchanging information among themselves with the intention of achieving a specified the performance of the vehicle network. A stochastic model for information flow is also considered, allowing

  4. STAR FORMATION IN NUCLEAR RINGS OF BARRED GALAXIES

    SciTech Connect (OSTI)

    Seo, Woo-Young; Kim, Woong-Tae, E-mail: seowy@astro.snu.ac.kr, E-mail: wkim@astro.snu.ac.kr [Center for the Exploration of the Origin of the Universe (CEOU), Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2013-06-01T23:59:59.000Z

    Nuclear rings in barred galaxies are sites of active star formation. We use hydrodynamic simulations to study the temporal and spatial behavior of star formation occurring in nuclear rings of barred galaxies where radial gas inflows are triggered solely by a bar potential. The star formation recipes include a density threshold, an efficiency, conversion of gas to star particles, and delayed momentum feedback via supernova explosions. We find that the star formation rate (SFR) in a nuclear ring is roughly equal to the mass inflow rate to the ring, while it has a weak dependence on the total gas mass in the ring. The SFR typically exhibits a strong primary burst followed by weak secondary bursts before declining to very small values. The primary burst is associated with the rapid gas infall to the ring due to the bar growth, while the secondary bursts are caused by re-infall of the ejected gas from the primary burst. While star formation in observed rings persists episodically over a few Gyr, the duration of active star formation in our models lasts for only about half of the bar growth time, suggesting that the bar potential alone is unlikely to be responsible for gas supply to the rings. When the SFR is low, most star formation occurs at the contact points between the ring and the dust lanes, leading to an azimuthal age gradient of young star clusters. When the SFR is large, on the other hand, star formation is randomly distributed over the whole circumference of the ring, resulting in no apparent azimuthal age gradient. Since the ring shrinks in size with time, star clusters also exhibit a radial age gradient, with younger clusters found closer to the ring. The cluster mass function is well described by a power law, with a slope depending on the SFR. Giant gas clouds in the rings have supersonic internal velocity dispersions and are gravitationally bound.

  5. Physical control oriented model of large scale refrigerators to synthesize advanced control schemes. Design, validation, and first control results

    SciTech Connect (OSTI)

    Bonne, François; Bonnay, Patrick [INAC, SBT, UMR-E 9004 CEA/UJF-Grenoble, 17 rue des Martyrs, 38054 Grenoble (France); Alamir, Mazen [Gipsa-Lab, Control Systems Department, CNRS-University of Grenoble, 11, rue des Mathématiques, BP 46, 38402 Saint Martin d'Hères (France)

    2014-01-29T23:59:59.000Z

    In this paper, a physical method to obtain control-oriented dynamical models of large scale cryogenic refrigerators is proposed, in order to synthesize model-based advanced control schemes. These schemes aim to replace classical user experience designed approaches usually based on many independent PI controllers. This is particularly useful in the case where cryoplants are submitted to large pulsed thermal loads, expected to take place in the cryogenic cooling systems of future fusion reactors such as the International Thermonuclear Experimental Reactor (ITER) or the Japan Torus-60 Super Advanced Fusion Experiment (JT-60SA). Advanced control schemes lead to a better perturbation immunity and rejection, to offer a safer utilization of cryoplants. The paper gives details on how basic components used in the field of large scale helium refrigeration (especially those present on the 400W @1.8K helium test facility at CEA-Grenoble) are modeled and assembled to obtain the complete dynamic description of controllable subsystems of the refrigerator (controllable subsystems are namely the Joule-Thompson Cycle, the Brayton Cycle, the Liquid Nitrogen Precooling Unit and the Warm Compression Station). The complete 400W @1.8K (in the 400W @4.4K configuration) helium test facility model is then validated against experimental data and the optimal control of both the Joule-Thompson valve and the turbine valve is proposed, to stabilize the plant under highly variable thermals loads. This work is partially supported through the European Fusion Development Agreement (EFDA) Goal Oriented Training Program, task agreement WP10-GOT-GIRO.

  6. Carbon-nitrogen interactions regulate climate-carbon cycle feedbacks: results from an atmosphere-ocean general circulation model

    E-Print Network [OSTI]

    Thornton, P. E.; Doney, S. C.; Lindsay, Keith; Moore, J. K.; Mahowald, N. M.; Randerson, J. T.; Fung, I.; Lamarque, J. F.; Feddema, Johannes J.

    2009-01-01T23:59:59.000Z

    Biogeosciences, 6, 2099–2120, 2009 www.biogeosciences.net/6/2099/2009/ © Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License. Biogeosciences Carbon-nitrogen interactions regulate climate-carbon cycle feedbacks.... Inclusion of fundamental ecological interactions between carbon and nitrogen cycles in the land component of an atmosphere-ocean general circulation model (AOGCM) leads to decreased carbon uptake associated with CO2 fertil- ization, and increased carbon...

  7. BASIN ANALYSIS OF THE MISSISSIPPI INTERIOR SALT BASIN AND PETROLEUM SYSTEM MODELING OF THE JURASSIC SMACKOVER FORMATION, EASTERN GULF COASTAL PLAIN

    SciTech Connect (OSTI)

    Ernest A,. Mancini

    1999-04-09T23:59:59.000Z

    Part 2 (Basin Analysis of the Mississippi Interior Salt Basin) objectives are to provide a comprehensive analysis of the Mississippi Interior Salt Basin in Years 2 and 3 of the project and to transfer effectively the research results to producers through workshops and topical reports. Work accomplished so far: (Task 1) Tectonic History--Petroleum traps in the Mississippi Interior Salt Basin have been characterized. (Task 2) Depositional History--The depositional systems for Mesozoic strata in the Mississippi Interior Salt Basin have been identified and characterized. (Task 3) Fluid Flow--Modeling of 1-D burial and thermal history profiles for 48 wells in the Mississippi Interior Salt Basin has been completed. Multidimensional thermal maturity modeling has been initiated. (Task 4) Underdeveloped Plays--Three major exploration plays have been identified. These include the basement ridge play, the regional peripheral fault trend play, and the salt anticline play. (Task 5) Technology Transfer--No work was performed on this task for this quarter. (Task 6) Topical Reports--The topical reports on the tectonic, depositional, burial and thermal histories of the Mississippi Interior Salt Basin have been completed and sent to DOE.

  8. Pocket formation and the flame surface density equation

    SciTech Connect (OSTI)

    Kollman, W. [Univ. of California, Davis, CA (United States); Chen, J.H. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility

    1998-03-01T23:59:59.000Z

    The occurrence and properties of singularities in the equation for the surface density function {sigma} {triple_bond}{vert_bar}{del}{Phi}{vert_bar} are analyzed analytically and numerically using data from two dimensional direct numerical simulation (DNS) of pocket formation in a premixed methane-air flame. The various stages and the relevant time scales associated with pocket formation were determined in a previous study. It was found that isolated pockets form if and only if a nondegenerate critical point of a saddle point type appears. The appearance of a singularity in the isoline representing the flame front may have implications to modeling of the terms in the surface density function (sdf) approach during such transient events as pocket formation. The sink and source terms in sdf are evaluated in the neighborhood of a critical point using DNS data during pocket formation, and an analytic representation of a scalar in the vicinity of the critical point which allows for the computation of all kinematic properties. The analytic and computational results show that the normal restoration and dissipation terms in the sdf become singular at the critical point when the pocket emerges. Furthermore, the analytic results show that the singularities exactly cancel, and therefore, the main conclusion is that it is unnecessary to model the singular behavior of these terms at critical points. However, closure of their sum is recommended.

  9. Model of Procedure Usage – Results from a Qualitative Study to Inform Design of Computer-Based Procedures

    SciTech Connect (OSTI)

    Johanna H Oxstrand; Katya L Le Blanc

    2012-07-01T23:59:59.000Z

    The nuclear industry is constantly trying to find ways to decrease the human error rate, especially the human errors associated with procedure use. As a step toward the goal of improving procedure use performance, researchers, together with the nuclear industry, have been looking at replacing the current paper-based procedures with computer-based procedure systems. The concept of computer-based procedures is not new by any means; however most research has focused on procedures used in the main control room. Procedures reviewed in these efforts are mainly emergency operating procedures and normal operating procedures. Based on lessons learned for these previous efforts we are now exploring a more unknown application for computer based procedures - field procedures, i.e. procedures used by nuclear equipment operators and maintenance technicians. The Idaho National Laboratory, the Institute for Energy Technology, and participants from the U.S. commercial nuclear industry are collaborating in an applied research effort with the objective of developing requirements and specifications for a computer-based procedure system to be used by field operators. The goal is to identify the types of human errors that can be mitigated by using computer-based procedures and how to best design the computer-based procedures to do this. The underlying philosophy in the research effort is “Stop – Start – Continue”, i.e. what features from the use of paper-based procedures should we not incorporate (Stop), what should we keep (Continue), and what new features or work processes should be added (Start). One step in identifying the Stop – Start – Continue was to conduct a baseline study where affordances related to the current usage of paper-based procedures were identified. The purpose of the study was to develop a model of paper based procedure use which will help to identify desirable features for computer based procedure prototypes. Affordances such as note taking, markups, sharing procedures between fellow coworkers, the use of multiple procedures at once, etc. were considered. The model describes which affordances associated with paper based procedures should be transferred to computer-based procedures as well as what features should not be incorporated. The model also provides a means to identify what new features not present in paper based procedures need to be added to the computer-based procedures to further enhance performance. The next step is to use the requirements and specifications to develop concepts and prototypes of computer-based procedures. User tests and other data collection efforts will be conducted to ensure that the real issues with field procedures and their usage are being addressed and solved in the best manner possible. This paper describes the baseline study, the construction of the model of procedure use, and the requirements and specifications for computer-based procedures that were developed based on the model. It also addresses how the model and the insights gained from it were used to develop concepts and prototypes for computer based procedures.

  10. Deformed shell model results for neutrinoless double beta decay of nuclei in A=60-90 region

    E-Print Network [OSTI]

    R. Sahu; V. K. B. Kota

    2014-09-17T23:59:59.000Z

    Nuclear transition matrix elements (NTME) for the neutrinoless double beta decay of $^{70}$Zn, $^{80}$Se and $^{82}$Se nuclei are calculated within the framework of the deformed shell model based on Hartree-Fock states. For $^{70}$Zn, jj44b interaction in $^{2}p_{3/2}$, $^{1}f_{5/2}$, $^{2}p_{1/2}$ and $^{1}g_{9/2}$ space with $^{56}$Ni as the core is employed. However, for $^{80}$Se and $^{82}$Se nuclei, a modified Kuo interaction with the above core and model space are employed. Most of our calculations in this region were performed with this effective interaction. However, jj44b interaction has been found to be better for $^{70}$Zn. After ensuring that DSM gives good description of the spectroscopic properties of low-lying levels in these three nuclei considered, the NTME are calculated. The deduced half-lives with these NTME, assuming neutrino mass is 1 eV, are $9.6 \\times 10^{25}$yr, $1.9 \\times 10^{27}$yr and $1.95 \\times 10^{24}$yr for $^{70}$Zn, $^{80}$Se and $^{82}$Se, respectively.

  11. Deformed shell model results for neutrinoless double beta decay of nuclei in A=60-90 region

    E-Print Network [OSTI]

    Sahu, R

    2014-01-01T23:59:59.000Z

    Nuclear transition matrix elements (NTME) for the neutrinoless double beta decay of $^{70}$Zn, $^{80}$Se and $^{82}$Se nuclei are calculated within the framework of the deformed shell model based on Hartree-Fock states. For $^{70}$Zn, jj44b interaction in $^{2}p_{3/2}$, $^{1}f_{5/2}$, $^{2}p_{1/2}$ and $^{1}g_{9/2}$ space with $^{56}$Ni as the core is employed. However, for $^{80}$Se and $^{82}$Se nuclei, a modified Kuo interaction with the above core and model space are employed. Most of our calculations in this region were performed with this effective interaction. However, jj44b interaction has been found to be better for $^{70}$Zn. After ensuring that DSM gives good description of the spectroscopic properties of low-lying levels in these three nuclei considered, the NTME are calculated. The deduced half-lives with these NTME, assuming neutrino mass is 1 eV, are $9.6 \\times 10^{25}$yr, $1.9 \\times 10^{27}$yr and $1.95 \\times 10^{24}$yr for $^{70}$Zn, $^{80}$Se and $^{82}$Se, respectively.

  12. FY 2010 Fourth Quarter Report: Evaluation of the Dependency of Drizzle Formation on Aerosol Properties

    SciTech Connect (OSTI)

    Lin, W; McGraw, R; Liu, Y; Wang, J; Vogelmann, A; Daum, PH

    2010-10-01T23:59:59.000Z

    Metric for Quarter 4: Report results of implementation of composite parameterization in single-column model (SCM) to explore the dependency of drizzle formation on aerosol properties. To better represent VOCALS conditions during a test flight, the Liu-Duam-McGraw (LDM) drizzle parameterization is implemented in the high-resolution Weather Research and Forecasting (WRF) model, as well as in the single-column Community Atmosphere Model (CAM), to explore this dependency.

  13. A Comparison of Independent Star Formation Diagnostics for a UV-Selected Sample of Nearby Galaxies

    E-Print Network [OSTI]

    Sullivan, M; Chan, B; Cram, L; Ellis, R; Treyer, M A; Hopkins, A; Sullivan, Mark; Mobasher, Bahram; Chan, Ben; Cram, Lawrence; Ellis, Richard; Treyer, Marie; Hopkins, Andrew

    2001-01-01T23:59:59.000Z

    We present results from a decimetric radio survey undertaken with the Very Large Array as part of a longer term goal to inter-compare star formation and dust extinction diagnostics, on a galaxy by galaxy basis, for a representative sample of nearby galaxies. For our survey field, Selected Area 57, star formation rates derived from 1.4GHz luminosities are compared with earlier nebular emission line and ultraviolet (UV) continuum diagnostics. We find broad correlations, over several decades in luminosity, between H-alpha, the UV continuum and 1.4GHz diagnostics. However, the scatter in these relations is found to be larger than observational errors, with offsets between the observed relations and those expected assuming constant star-formation histories and luminosity-independent extinction models. We investigate the physical origin of the observed relations, and conclude the discrepancies between different star-formation diagnostics can only be partly explained by simple models of dust extinction in galaxies. ...

  14. The rapidly evolving field of decadal climate prediction, using initialized climate models to produce time-evolving predictions of regional climate, is producing new results for

    E-Print Network [OSTI]

    , and it is on those time scales of interest to water managers that decadal climate prediction is being appliedThe rapidly evolving field of decadal climate prediction, using initialized climate models to produce time-evolving predictions of regional climate, is producing new results for predictions

  15. 15APR91 DDT results on a Sun IPC, a Sun Sparcstation 2, a IBM RS/6000 Model 550, and a

    E-Print Network [OSTI]

    Groppi, Christopher

    15APR91 DDT results on a Sun IPC, a Sun Sparcstation 2, a IBM RS/6000 Model 550, and a Convex C1. Brian Glendenning & Gareth Hunt November 13, 1991 1 Introduction The Large DDT has been run on a Sun IPC

  16. Characterizing fractured rock for fluid-flow, geomechanical, and paleostress modeling: Methods and preliminary results from Yucca Mountain, Nevada

    SciTech Connect (OSTI)

    Barton, C.C.; Larsen, E.; Page, W.R.; Howard, T.M.

    1993-12-31T23:59:59.000Z

    Fractures have been characterized for fluid-flow, geomechanical, and paleostress modeling at three localities in the vicinity of drill hole USW G-4 at Yucca Mountain in southwestern Nevada. A method for fracture characterization is introduced that integrates mapping fracture-trace networks and quantifying eight fracture parameters: trace length, orientation, connectivity, aperture, roughness, shear offset, trace-length density, and mineralization. A complex network of fractures was exposed on three 214- to 260-m 2 pavements cleared of debris in the upper lithophysal unit of the Tiva Canyon Member of the Miocene Paint-brush Tuff. The pavements are two-dimensional sections through the three-dimensional network of strata-bound fractures. All fractures with trace lengths greater than 0.2 m were mapped and studied.

  17. Basin Analysis of the Mississippi Interior Salt Basin and Petroleum System Modeling of the Jurassic Smackover Formation, Eastern Gulf Coastal Plain

    SciTech Connect (OSTI)

    Mancini, Ernest A.

    2003-02-06T23:59:59.000Z

    The project objectives are improving access to information for the Mississippi Interior Salt Basin by inventorying data files and records of the major information repositories in the region, making these inventories easily accessible in electronic format, increasing the amount of information available on domestic sedimentary basins through a comprehensive analysis of the Mississippi Interior Salt Basin, and enhancing the understanding of the petroleum systems operating in the Mississippi Interior Salt Basin.

  18. ABSTRACT & DISSERTATION FORMAT GUIDELINES

    E-Print Network [OSTI]

    Lu, Yi

    2 ABSTRACT & DISSERTATION FORMAT GUIDELINES The Knowledge Navigation Center (second floor these guidelines. The most up-to-date version of the Abstract and Dissertation Format Guidelines is available;2 Abstract Format Guidelines ABSTRACT Title of the Dissertation by by Student's Name Chair: Chair's name Text

  19. Formation evaluation MWD enters new capability realm

    SciTech Connect (OSTI)

    Hearn, F. (Baker Hughes INTEQ, Houston, TX (United States))

    1994-11-01T23:59:59.000Z

    Recent industry advances in formation evaluation measurement-while-drilling (FEMWD) have been achieved in well log data acquisition quality and in geosteering drilling applications. This paper presents new technology as applied by Baker Hughes INTEQ which includes: geosteering techniques which help navigate through horizontally drilled reservoirs including improved quality dual propagation resistivity, neutron-porosity and formation-density measurements; predictive modeling of tool responses in reservoir geosteering applications; environmental computer modeling which aids interpretation, including tool eccentering; and new measurement enhancements.

  20. Pattern formation and propagation during microwave breakdown

    SciTech Connect (OSTI)

    Chaudhury, Bhaskar [Laboratoire Plasma et Conversion d'Energie (LAPLACE), INPT, UPS, Universite de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); Boeuf, Jean-Pierre [Laboratoire Plasma et Conversion d'Energie (LAPLACE), INPT, UPS, Universite de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); LAPLACE, CNRS, F-31062 Toulouse (France); Zhu, Guo Qiang [Laboratoire Plasma et Conversion d'Energie (LAPLACE), INPT, UPS, Universite de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); Northwestern Polytechnique University, Xi'an 710072 (China)

    2010-12-15T23:59:59.000Z

    During microwave breakdown at atmospheric pressure, a sharp plasma front forms and propagates toward the microwave source at high velocities. Experiments show that the plasma front may exhibit a complex dynamical structure or pattern composed of plasma filaments aligned with the wave electric field and apparently moving toward the source. In this paper, we present a model of the pattern formation and propagation under conditions close to recent experiments. Maxwell's equations are solved together with plasma fluid equations in two dimensions to describe the space and time evolution of the wave field and plasma density. The simulation results are in excellent agreement with the experimental observations. The model provides a physical interpretation of the pattern formation and dynamics in terms of ionization-diffusion and absorption-reflection mechanisms. The simulations allow a good qualitative and quantitative understanding of different features such as plasma front velocity, spacing between filaments, maximum plasma density in the filaments, and influence of the discharge parameters on the development of well-defined filamentary plasma arrays or more diffuse plasma fronts.

  1. Numerical modeling of carbon dioxide sequestration on the rate of pressure solution creep in limestone: Preliminary results

    E-Print Network [OSTI]

    Renard, Francois; Hellmann, Roland; Collombet, Marielle; Guen, Yvi Le

    2008-01-01T23:59:59.000Z

    When carbon dioxide (CO2) is injected into an aquifer or a depleted geological reservoir, its dissolution into solution results in acidification of the pore waters. As a consequence, the pore waters become more reactive, which leads to enhanced dissolution-precipitation processes and a modification of the mechanical and hydrological properties of the rock. This effect is especially important for limestones given that the solubility and reactivity of carbonates is strongly dependent on pH and the partial pressure of CO2. The main mechanism that couples dissolution, precipitation and rock matrix deformation is commonly referred to as intergranular pressure solution creep (IPS) or pervasive pressure solution creep (PSC). This process involves dissolution at intergranular grain contacts subject to elevated stress, diffusion of dissolved material in an intergranular fluid, and precipitation in pore spaces subject to lower stress. This leads to an overall and pervasive reduction in porosity due to both grain indent...

  2. On the star formation history of IZw 18

    E-Print Network [OSTI]

    F. Legrand

    1999-12-06T23:59:59.000Z

    It has been suggested that a continuous low star formation rate has been the dominant regime in IZw 18 and in dwarf galaxies for the lifetime of these objects (Legrand et al. 1999). Here, we discuss and model various star-forming histories for IZw 18. Particularly, we show that if the metallicity observed in IZw 18 results from starburst events only, the observed colors constrain the fraction of the metals ejected from the galaxy to be less than 50-70 %. We demonstrate that the continuous star formation scenario reproduces the observed parameters of IZw 18. A continuous star formation rate (SFR) of about 10E-4 Msol/yr during 14 Gyr reproduces precisely the observed abundances. This SFR is comparable with the lowest SFR observed in low surface brightness galaxies (van Zee et al. 1997). Generalized to all galaxies, the low continuous SFR scenario accounts for various facts: the presence of star formation in quiescent dwarfs and LSBG, the metallicity increase with time in the most underabundant DLA systems, and the metal content extrapolations to the outskirts of spiral galaxies. Also the apparent absence of galaxies with a metallicity lower than IZw 18, the apparent absence of HI clouds without optical counterparts, and the homogeneity of abundances in dwarfs galaxies are natural outcomes of the scenario. This implies that, even if starbursts are strong and important events in the life of galaxies, their more subdued but continuous star formation regime cannot be ignored when accounting for their chemical evolution.

  3. Comparison of the PHISICS/RELAP5-3D Ring and Block Model Results for Phase I of the OECD MHTGR-350 Benchmark

    SciTech Connect (OSTI)

    Gerhard Strydom

    2014-04-01T23:59:59.000Z

    The INL PHISICS code system consists of three modules providing improved core simulation capability: INSTANT (performing 3D nodal transport core calculations), MRTAU (depletion and decay heat generation) and a perturbation/mixer module. Coupling of the PHISICS code suite to the thermal hydraulics system code RELAP5-3D has recently been finalized, and as part of the code verification and validation program the exercises defined for Phase I of the OECD/NEA MHTGR 350 MW Benchmark were completed. This paper provides an overview of the MHTGR Benchmark, and presents selected results of the three steady state exercises 1-3 defined for Phase I. For Exercise 1, a stand-alone steady-state neutronics solution for an End of Equilibrium Cycle Modular High Temperature Reactor (MHTGR) was calculated with INSTANT, using the provided geometry, material descriptions, and detailed cross-section libraries. Exercise 2 required the modeling of a stand-alone thermal fluids solution. The RELAP5-3D results of four sub-cases are discussed, consisting of various combinations of coolant bypass flows and material thermophysical properties. Exercise 3 combined the first two exercises in a coupled neutronics and thermal fluids solution, and the coupled code suite PHISICS/RELAP5-3D was used to calculate the results of two sub-cases. The main focus of the paper is a comparison of the traditional RELAP5-3D “ring” model approach vs. a much more detailed model that include kinetics feedback on individual block level and thermal feedbacks on a triangular sub-mesh. The higher fidelity of the block model is illustrated with comparison results on the temperature, power density and flux distributions, and the typical under-predictions produced by the ring model approach are highlighted.

  4. The Nitrogen-to-Oxygen evolution in galaxies: the role of the star formation rate

    E-Print Network [OSTI]

    M. Mollá; J. M. Vílchez; M. Gavilán; A. I. Díaz

    2006-08-10T23:59:59.000Z

    The main objective of the present work is to ckeck if the star formation efficiency plays a relevant role in the evolution of the relative abundance N/O. We analyze the evolution of the nitrogen-to-oxygen ratio as predicted by a set of computed theoretical models of simulated galaxies with different total masses which are evolved assuming different collapse time scales and different star formation efficiencies, thus producing different star formation histories. The stellar yield set we use for all of them (Gavil\\'{a}n et al. 2005) have an important contribution of primary nitrogen proceeding from low and intermediate mass stars. It allows to obtain a dispersion of results in the N/O-O/H plane, when star formation efficiencies vary, in general agreement with observations. The model results for the N/O abundance ratio are in good agreement with most observational data trends: the extragalactic H{\\sc ii} regions is well reproduced with present time resulting abundances and the low N/O values estimated for high-redshift objects, as well as the higher and constant values of N/O observed for irregular and dwarf galaxies or halo stars, can be simultaneously obtained with our models at the same low oxygen abundances. We conclude that differences in the star formation history of galaxies and regions within them are a key factor to explain the data in the N/O-O/H plane.

  5. Feedback from Protostellar Outflows in Star and Star Cluster Formation

    E-Print Network [OSTI]

    Christopher D. Matzner

    2000-07-13T23:59:59.000Z

    Magnetic stresses collimate protostellar winds into a common distribution of force with angle. Sweeping into the ambient medium, such winds drive bipolar molecular outflows whose properties are insensitive to the distribution of ambient gas and to the details of how the wind is launched, and how its intensity varies over time. Moreover, these properties are in accord with the commonly observed features of outflows. This model is simple enough to permit a quantitative study of the feedback effects from low-mass star formation. It predicts the rate at which star-forming gas is ejected by winds, and hence the efficiency with which stars form. Applied to individual star formation, it relates the stellar initial mass function to the distribution of pre-stellar cores. Applied to cluster formation, it indicates whether the resulting stellar system will remain gravitationally bound. Using the energy injection and mass ejection implied by this model, we investigate the dynamical evolution of a molecular clump as a stellar cluster forms within it. This depends critically on the rate at which turbulence decays: it may involve equilibrium star formation (slow decay), overstable oscillations, or collapse (fast decay).

  6. SIMULATION OF THE FORMATION OF A SOLAR ACTIVE REGION

    SciTech Connect (OSTI)

    Cheung, M. C. M.; Title, A. M. [Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA 94304 (United States); Rempel, M. [High Altitude Observatory, NCAR, P.O. Box 3000, Boulder, CO 80307 (United States); Schuessler, M. [Max Planck Institute for Solar System Research, Katlenburg-Lindau, 37191 (Germany)

    2010-09-01T23:59:59.000Z

    We present a radiative magnetohydrodynamics simulation of the formation of an active region (AR) on the solar surface. The simulation models the rise of a buoyant magnetic flux bundle from a depth of 7.5 Mm in the convection zone up into the solar photosphere. The rise of the magnetic plasma in the convection zone is accompanied by predominantly horizontal expansion. Such an expansion leads to a scaling relation between the plasma density and the magnetic field strength such that B {proportional_to} rhov{sup 1/2}. The emergence of magnetic flux into the photosphere appears as a complex magnetic pattern, which results from the interaction of the rising magnetic field with the turbulent convective flows. Small-scale magnetic elements at the surface first appear, followed by their gradual coalescence into larger magnetic concentrations, which eventually results in the formation of a pair of opposite polarity spots. Although the mean flow pattern in the vicinity of the developing spots is directed radially outward, correlations between the magnetic field and velocity field fluctuations allow the spots to accumulate flux. Such correlations result from the Lorentz-force-driven, counterstreaming motion of opposite polarity fragments. The formation of the simulated AR is accompanied by transient light bridges between umbrae and umbral dots. Together with recent sunspot modeling, this work highlights the common magnetoconvective origin of umbral dots, light bridges, and penumbral filaments.

  7. Combined results of searches for the standard model Higgs boson in pp collisions at sqrt(s) = 7 TeV

    E-Print Network [OSTI]

    CMS Collaboration

    2012-02-07T23:59:59.000Z

    Combined results are reported from searches for the standard model Higgs boson in proton-proton collisions at sqrt(s)=7 TeV in five Higgs boson decay modes: gamma pair, b-quark pair, tau lepton pair, W pair, and Z pair. The explored Higgs boson mass range is 110-600 GeV. The analysed data correspond to an integrated luminosity of 4.6-4.8 inverse femtobarns. The expected excluded mass range in the absence of the standard model Higgs boson is 118-543 GeV at 95% CL. The observed results exclude the standard model Higgs boson in the mass range 127-600 GeV at 95% CL, and in the mass range 129-525 GeV at 99% CL. An excess of events above the expected standard model background is observed at the low end of the explored mass range making the observed limits weaker than expected in the absence of a signal. The largest excess, with a local significance of 3.1 sigma, is observed for a Higgs boson mass hypothesis of 124 GeV. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-600 (110-145) GeV is estimated to be 1.5 sigma (2.1 sigma). More data are required to ascertain the origin of this excess.

  8. Combined results of searches for the standard model Higgs boson in pp collisions at sqrt(s) = 7 TeV

    SciTech Connect (OSTI)

    Chatrchyan, Serguei [Yerevan Physics Inst. (Armenia); et al.

    2012-03-01T23:59:59.000Z

    Combined results are reported from searches for the standard model Higgs boson in proton-proton collisions at sqrt(s)=7 TeV in five Higgs boson decay modes: gamma pair, b-quark pair, tau lepton pair, W pair, and Z pair. The explored Higgs boson mass range is 110-600 GeV. The analysed data correspond to an integrated luminosity of 4.6-4.8 inverse femtobarns. The expected excluded mass range in the absence of the standard model Higgs boson is 118-543 GeV at 95% CL. The observed results exclude the standard model Higgs boson in the mass range 127-600 GeV at 95% CL, and in the mass range 129-525 GeV at 99% CL. An excess of events above the expected standard model background is observed at the low end of the explored mass range making the observed limits weaker than expected in the absence of a signal. The largest excess, with a local significance of 3.1 sigma, is observed for a Higgs boson mass hypothesis of 124 GeV. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-600 (110-145) GeV is estimated to be 1.5 sigma (2.1 sigma). More data are required to ascertain the origin of this excess.

  9. First Structure Formation and the First Stars

    E-Print Network [OSTI]

    Michael L. Norman; Tom Abel; Greg Bryan

    2000-05-11T23:59:59.000Z

    We discuss the results of recent 3D simulations of first structure formation in relationship to the formation of the first stars. On the basis of a new, high-resolution AMR simulation (spatial dynamic range = 30,000,000), we conclude that the first stars are likely to be massive.

  10. Heating tar sands formations to visbreaking temperatures

    DOE Patents [OSTI]

    Karanikas, John Michael (Houston, TX); Colmenares, Tulio Rafael (Houston, TX); Zhang, Etuan (Houston, TX); Marino, Marian (Houston, TX); Roes, Augustinus Wilhelmus Maria (Houston, TX); Ryan, Robert Charles (Houston, TX); Beer, Gary Lee (Houston, TX); Dombrowski, Robert James (Houston, TX); Jaiswal, Namit (Houston, TX)

    2009-12-22T23:59:59.000Z

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat may be controlled so that at least a majority of the section reaches an average temperature of between 200.degree. C. and 240.degree. C., which results in visbreaking of at least some hydrocarbons in the section. At least some visbroken hydrocarbon fluids may be produced from the formation.

  11. Numerical modeling of injection and mineral trapping of CO2 with H2S and SO2 in a Sandstone Formation

    E-Print Network [OSTI]

    Xu, Tianfu; Apps, John A.; Pruess, Karsten; Yamamoto, Hajime

    2008-01-01T23:59:59.000Z

    Australia. Am. Assoc. Petrol. Geol. Bull. 76(8), 1224-1249.modeling. Mineral. and Petrol. 59, 121-140. Gunter, W.D. ,

  12. Implementing Feedback in Simulations of Galaxy Formation: A Survey of Methods

    E-Print Network [OSTI]

    R. J. Thacker; H. M. P. Couchman

    2000-01-15T23:59:59.000Z

    We present a detailed investigation of different approaches to modeling feedback in simulations of galaxy formation. Gas-dynamic forces are evaluated using Smoothed Particle Hydrodynamics (SPH) while star formation and supernova feedback are included using a three parameter model which determines the star formation rate normalization, feedback energy and lifetime of feedback regions. The star formation rate is calculated using a Lagrangian Schmidt Law for all gas particles which satisfy temperature, density and convergent flow criteria. Feedback is incorporated as thermal heating of the ISM. We compare the effects of distributing this energy over the smoothing scale or depositing it on a single particle. Radiative losses are prevented from heated particles by adjusting the density used in radiative cooling. We test the models on the formation of galaxies from cosmological initial conditions and also on isolated Milky Way and dwarf galaxies. Extremely violent feedback is necessary to produce a gas disk with angular momentum remotely close to that of observed disk galaxies. This is a result of the extreme central concentration of the dark halos in the sCDM model, and the pervasiveness of the core-halo angular momentum transport mechanism. We emphasize that the disks formed in hierarchical simulations are partially a numerical artifact produced by the minimum mass scale of the simulation acting as a highly efficient `support' mechanism. Disk formation is strongly affected by the treatment of dense regions in SPH, which along with the difficulty of representing the hierarchical formation process, means that realistic simulations of galaxy formation require far higher resolution than currently used.

  13. The Formation and Fragmentation of Primordial Molecular Clouds

    E-Print Network [OSTI]

    Tom Abel; Greg L. Bryan; Michael L. Norman

    1998-10-14T23:59:59.000Z

    Many questions in physical cosmology regarding the thermal history of the intergalactic medium, chemical enrichment, reionization, etc. are thought to be intimately related to the nature and evolution of pregalactic structure. In particular the efficiency of primordial star formation and the primordial IMF are of special interest. We present results from high resolution three-dimensional adaptive mesh refinement simulations that follow the collapse of primordial molecular clouds and their subsequent fragmentation within a cosmologically representative volume. Comoving scales from 128 kpc down to 0.5 pc are followed accurately. Dark matter dynamics, hydrodynamics and all relevant chemical and radiative processes (cooling) are followed self-consistently for a cluster normalized CDM structure formation model. Primordial molecular clouds with ~100,000 solar masses are assembled by mergers of multiple objects that have formed hydrogen molecules in the gas phase with a fractional abundance of 100,000/cm^3 are found. We find that less than 1% of the primordial gas in such small scale structures cools and collapses to sufficiently high densities to be available for primordial star formation. Furthermore, our results indicate that the formation of very massive objects, massive black holes, fragmentation of a large fraction of baryons into brown dwars or Jupiter size fragments seems, in contrast to various claims in the literature, very unlikely. The expected escape fraction of UV photons with (h nu) > 11eV is very small.

  14. Formation of in-volume nanogratings with sub-100 nm periods in glass by femtosecond laser irradiation

    E-Print Network [OSTI]

    Liao, Yang; Cui, Yun; Qiao, Lingling; Bellouard, Yves; Sugioka, Koji; Cheng, Ya

    2015-01-01T23:59:59.000Z

    We present direct experimental observation of the morphological evolution during the formation of nanogratings with sub-100-nm periods with the increasing number of pulses. Theoretical simulation shows that the constructive interference of the scattering light from original nanoplanes will create an intensity maximum located between the two adjacent nanoplanes, resulting in shortening of the nanograting period by half. The proposed mechanism enables explaining the formation of nanogratings with periods beyond that predicted by the nanoplasmonic model.

  15. aggregation rosette formation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    formed from an ensemble of charged proteins. The model predicts the formation of multi-fractal structures with the geometry of the growth determined by the electrostatic...

  16. Petrophysical evaluation of subterranean formations

    DOE Patents [OSTI]

    Klein, James D; Schoderbek, David A; Mailloux, Jason M

    2013-05-28T23:59:59.000Z

    Methods and systems are provided for evaluating petrophysical properties of subterranean formations and comprehensively evaluating hydrate presence through a combination of computer-implemented log modeling and analysis. Certain embodiments include the steps of running a number of logging tools in a wellbore to obtain a variety of wellbore data and logs, and evaluating and modeling the log data to ascertain various petrophysical properties. Examples of suitable logging techniques that may be used in combination with the present invention include, but are not limited to, sonic logs, electrical resistivity logs, gamma ray logs, neutron porosity logs, density logs, NRM logs, or any combination or subset thereof.

  17. The role of asymmetric excitation in self-organized nanostructure formation upon femtosecond laser ablation

    SciTech Connect (OSTI)

    Reif, Juergen; Varlamova, Olga; Varlamov, Sergej; Bestehorn, Michael [Brandenburgische Technische Universitaet (BTU) Cottbus Platz der Deutschen Einheit 1, 03046 Cottbus (Germany); Brandenburgische Technische Universitaet (BTU) Cottbus Platz der Deutschen Einheit 1, 03046 Cottbus (Germany)

    2012-07-30T23:59:59.000Z

    Surface pattering upon multi-pulse femtosecond laser ablation is modeled by a non-linear-dynamic erosion/smoothing model, similar to structure formation during ion sputtering. The model is adopted to account for the influence of laser polarization on nanostructure features. Based on a nonlinear equation of the Kuramoto-Siavshinsky type, it is shown that the directional anisotropy in the pattern formation may result from a spatial anisotropy of the initial excitation/energy-coupling process, such as resonant coupling to surface plasmons/polaritons, or electron diffusion properties. Also, anisotropy of elasto-dynamic surface and diffusion properties may be involved. A comparison of numeric simulations based on the model with corresponding experi-mental results gives a very good agreement.

  18. System-level modeling for geological storage of CO2

    E-Print Network [OSTI]

    Zhang, Yingqi; Oldenburg, Curtis M.; Finsterle, Stefan; Bodvarsson, Gudmundur S.

    2006-01-01T23:59:59.000Z

    of Geologic Storage of CO2, in Carbon Dioxide Capture forFormations - Results from the CO2 Capture Project: GeologicBenson, Process Modeling of CO2 Injection into Natural Gas

  19. Composition Mixing during Blue Straggler Formation and Evolution

    E-Print Network [OSTI]

    Eric L. Sandquist; Michael Bolte; Lars Hernquist

    1996-09-25T23:59:59.000Z

    We use smoothed-particle hydrodynamics to examine differences between direct collisions of single stars and binary star mergers in their roles as possible blue straggler star formation mechanisms. We find in all cases that core helium in the progenitor stars is largely retained in the core of the remnant, almost independent of the type of interaction or the central concentration of the progenitor stars. We have also modelled the subsequent evolution of the hydrostatic remnants, including mass loss and energy input from the hydrodynamical interaction. The combination of the hydrodynamical and hydrostatic models enables us to predict that little mixing will occur during the merger of two globular cluster stars of equal mass. In contrast to the results of Proctor Sills, Bailyn, & Demarque (1995), we find that neither completely mixed nor unmixed models can match the absolute colors of observed blue stragglers in NGC 6397 at all luminosity levels. We also find that the color distribution is probably the crucial test for explanations of BSS formation - if stellar collisions or mergers are the correct mechanisms, a large fraction of the lifetime of the straggler must be spent away from the main sequence. This constraint appears to rule out the possibility of completely mixed models. For NGC 6397, unmixed models predict blue straggler lifetimes ranging from about 0.1 to 4 Gyr, while completely mixed models predict a range from about 0.6 to 4 Gyr.

  20. Vehicle Technologies Office Merit Review 2015: First Principles Modeling of SEI Formation on Bare and Surface/Additive Modified Silicon Anodes

    Broader source: Energy.gov [DOE]

    Presentation given by Texas A&M at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about first principles modeling of...

  1. Abstract--In this study, we describe the utility of the zebrafish model of in-vivo blood vessel formation as a tool for

    E-Print Network [OSTI]

    @uh.edu). traditional mammalian models of toxicology. A wide range of congenital diseases are associated with blood and this pollutant is posing danger to humans by intake of affected fish, ground water exposed to toxins, etc

  2. POX 186: A Dwarf Galaxy in the Process of Formation?

    E-Print Network [OSTI]

    Michael R. Corbin; William D. Vacca

    2002-08-20T23:59:59.000Z

    We present deep U, V and I band images of the "ultracompact" blue dwarf galaxy POX 186 obtained with the Planetary Camera 2 of the Hubble Space Telescope. We have also obtained a near-ultraviolet spectrum of the object with the Space Telescope Imaging Spectrograph, and combine this with a new ground-based optical spectrum. The images confirm the galaxy to be extremely small, with a maximum extent of only 300 pc, a luminosity ~ 10^-4 L*, and an estimated mass ~ 10^7 M(sun). Its morphology is highly asymmetric, with a tail of material on its western side that may be tidal in origin. The U-band image shows this tail to be part of a stream of material in which stars have recently formed. Most of the star formation in the galaxy is however concentrated in a central, compact (d ~ 10 - 15 pc) star cluster. The outer regions of the galaxy are significantly redder than the cluster, with V - I colors consistent with a population dominated by K and M stars. While these results rule out earlier speculation that POX 186 is a protogalaxy, its morphology, mass and active star formation suggest that it represents a recent (within ~ 10^8 yr) collision between two clumps of stars of sub-galactic size (~ 100 pc). POX 186 may thus be a very small dwarf galaxy that, dynamically speaking, is still in the process of formation. This interpretation is supported by the fact that it resides in a void, so its morphology cannot be explained as the result of an encounter with a more massive galaxy. Clumps of stars this small may represent the building blocks required by hierarchical models of galaxy formation, and these results also support the recent "downsizing" picture of galaxy formation in which the least massive objects are the last to form.

  3. Case Studies of Mass Transfer and Star Formation in Galaxy Collisions

    E-Print Network [OSTI]

    Curtis Struck

    2003-10-20T23:59:59.000Z

    The amount, timing and ultimate location of mass transfer and induced star formation in galaxy collisions are sensitive functions of orbital and galaxy structural parameters. I discuss the role of detailed case studies and describe the results for two systems, Arp 284 and NGC 2207/IC 2163, that have been studied with both multiwaveband observations, and detailed dynamical models. The models yield the mass transfer and compressional histories of the encounters and the ``probable causes'' or triggers of individual star-forming regions.

  4. Basin Analysis of the Mississippi Interior Salt Basin and Petroleum System Modeling of the Jurassic Smackover Formation, Eastern Gulf Coastal Plain, Final Report and Topical Reports 5-8 on Smackover Petroleum system and Underdevelopment Reservoirs

    SciTech Connect (OSTI)

    Mancini, Ernest A.; Puckett, T. Markham; Parcell, William C.; Llinas, Juan Carlos; Kopaska-Merkel, David C.; Townsend, Roger N.

    2002-03-05T23:59:59.000Z

    The Smackover Formation, a major hydrocarbon-producing horizon in the Mississippi Interior Salt Basin (MISB), conformably overlies the Norphlet Formation and is conformably overlain by the Buckner Anhydrite Member of the Haynesville Formation. The Norphlet-Smackover contact can be either gradational or abrupt. The thickness and lithofacies distribution of the Smackover Formation were controlled by the configuration of incipient paleotopography. The Smackover Formation has been subdivided into three informal members, referred to as the lower, middle and upper members.

  5. Search results | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High School (9-12) Teachers Search results Search results Enter terms Search Showing 1 - 4 of 4 results. Download The BEAM Project: Building Efficient Architectural Models This...

  6. Photophoresis boosts giant planet formation

    E-Print Network [OSTI]

    Teiser, Jens

    2013-01-01T23:59:59.000Z

    In the core accretion model of giant planet formation, a solid protoplanetary core begins to accrete gas directly from the nebula when its mass reaches about 5 earth masses. The protoplanet has at most a few million years to reach runaway gas accretion, as young stars lose their gas disks after 10 million years at the latest. Yet gas accretion also brings small dust grains entrained in the gas into the planetary atmosphere. Dust accretion creates an optically thick protoplanetary atmosphere that cannot efficiently radiate away the kinetic energy deposited by incoming planetesimals. A dust-rich atmosphere severely slows down atmospheric cooling, contraction, and inflow of new gas, in contradiction to the observed timescales of planet formation. Here we show that photophoresis is a strong mechanism for pushing dust out of the planetary atmosphere due to the momentum exchange between gas and dust grains. The thermal radiation from the heated inner atmosphere and core is sufficient to levitate dust grains and to ...

  7. Comparison and validation of HEU and LEU modeling results to HEU experimental benchmark data for the Massachusetts Institute of Technology MITR reactor.

    SciTech Connect (OSTI)

    Newton, T. H.; Wilson, E. H; Bergeron, A.; Horelik, N.; Stevens, J. (Nuclear Engineering Division); (MIT Nuclear Reactor Lab.)

    2011-03-02T23:59:59.000Z

    The Massachusetts Institute of Technology Reactor (MITR-II) is a research reactor in Cambridge, Massachusetts designed primarily for experiments using neutron beam and in-core irradiation facilities. It delivers a neutron flux comparable to current LWR power reactors in a compact 6 MW core using Highly Enriched Uranium (HEU) fuel. In the framework of its non-proliferation policies, the international community presently aims to minimize the amount of nuclear material available that could be used for nuclear weapons. In this geopolitical context, most research and test reactors both domestic and international have started a program of conversion to the use of Low Enriched Uranium (LEU) fuel. A new type of LEU fuel based on an alloy of uranium and molybdenum (UMo) is expected to allow the conversion of U.S. domestic high performance reactors like the MITR-II reactor. Towards this goal, comparisons of MCNP5 Monte Carlo neutronic modeling results for HEU and LEU cores have been performed. Validation of the model has been based upon comparison to HEU experimental benchmark data for the MITR-II. The objective of this work was to demonstrate a model which could represent the experimental HEU data, and therefore could provide a basis to demonstrate LEU core performance. This report presents an overview of MITR-II model geometry and material definitions which have been verified, and updated as required during the course of validation to represent the specifications of the MITR-II reactor. Results of calculations are presented for comparisons to historical HEU start-up data from 1975-1976, and to other experimental benchmark data available for the MITR-II Reactor through 2009. This report also presents results of steady state neutronic analysis of an all-fresh LEU fueled core. Where possible, HEU and LEU calculations were performed for conditions equivalent to HEU experiments, which serves as a starting point for safety analyses for conversion of MITR-II from the use of HEU fuel to the use of UMo LEU fuel.

  8. Cluster formation probability in the trans-tin and trans-lead nuclei

    E-Print Network [OSTI]

    K. P. Santhosh; R. K. Biju; Sabina Sahadevan

    2010-05-10T23:59:59.000Z

    Within our fission model, the Coulomb and proximity potential model (CPPM) cluster formation probabilities are calculated for different clusters ranging from carbon to silicon for the parents in the trans-tin and trans- lead regions. It is found that in trans-tin region the 12^C, 16^O, 20^Ne and 24^Mg clusters have maximum cluster formation probability and lowest half lives as compared to other clusters. In trans-lead region the 14^C, 18, 20^O, 23^F, 24,26^Ne, 28,30^Mg and 34^Si clusters have the maximum cluster formation probability and minimum half life, which show that alpha like clusters are most probable for emission from trans-tin region while non-alpha clusters are probable from trans-lead region. These results stress the role of neutron proton symmetry and asymmetry of daughter nuclei in these two cases.

  9. The Formation and Fragmentation of Primordial Molecular Clouds

    E-Print Network [OSTI]

    Abel, T; Norman, M L; Abel, Tom; Bryan, Greg L.; Norman, Michael L.

    1998-01-01T23:59:59.000Z

    Many questions in physical cosmology regarding the thermal history of the intergalactic medium, chemical enrichment, reionization, etc. are thought to be intimately related to the nature and evolution of pregalactic structure. In particular the efficiency of primordial star formation and the primordial IMF are of special interest. We present results from high resolution three-dimensional adaptive mesh refinement simulations that follow the collapse of primordial molecular clouds and their subsequent fragmentation within a cosmologically representative volume. Comoving scales from 128 kpc down to 0.5 pc are followed accurately. Dark matter dynamics, hydrodynamics and all relevant chemical and radiative processes (cooling) are followed self-consistently for a cluster normalized CDM structure formation model. Primordial molecular clouds with ~100,000 solar masses are assembled by mergers of multiple objects that have formed hydrogen molecules in the gas phase with a fractional abundance of 11eV is very small.

  10. The Formation and Fragmentation of Primordial Molecular Clouds

    E-Print Network [OSTI]

    Abel, T; Norman, M L; Abel, Tom; Bryan, Greg L.; Norman, Michael L.

    2000-01-01T23:59:59.000Z

    Many questions in physical cosmology regarding the thermal history of theintergalactic medium, chemical enrichment, reionization, etc. are thought to beintimately related to the nature and evolution of pregalactic structure. Inparticular the efficiency of primordial star formation and the primordial IMFare of special interest. We present results from high resolutionthree--dimensional adaptive mesh refinement simulations that follow thecollapse of primordial molecular clouds and their subsequent fragmentationwithin a cosmologically representative volume. Comoving scales from 128 kpcdown to 1 pc are followed accurately. Dark matter dynamics, hydrodynamics andall relevant chemical and radiative processes (cooling) are followedself-consistently for a cluster normalized CDM structure formation model.Primordial molecular clouds with ~10^5 solar masses are assembled by mergers ofmultiple objects that have formed hydrogen molecules in the gas phase with afractional abundance of ~10^-4. As the subclumps merge cooling ...

  11. Combatting Ionic Aggregation using Dielectric Forces Combining Modeling/Simulation and Experimental Results to Explain End-capping of Primary Amine Functionalized Polystyrene

    SciTech Connect (OSTI)

    Messman, Jamie M [ORNL; Goswami, Monojoy [ORNL; Pickel, Deanna L [ORNL; Uhrig, David [ORNL; Sumpter, Bobby G [ORNL; Mays, Jimmy [University of Tennessee, Knoxville (UTK)

    2011-01-01T23:59:59.000Z

    Chain-end functionalization of living poly(styryl)lithium using 1-(3-bromopropyl)-2,2,5,5-tetramethyl-1-aza-2,5-disilacyclo-pentane (BTDP) to generate primary amine end-functionalized polystyrene was investigated using high vacuum anionic polymerization techniques. 13C NMR spectroscopy and Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) were used to evaluate polymer end-groups and demonstrated that quantitative amine functionalized polymer was attained under appropriate reaction conditions. In general, the polymerization of styrene was conducted in benzene and the end-capping reaction was performed by adding tetrahydrofuran (THF) to the reaction prior to the addition of BTDP in THF at room temperature. Results indicated that approximately 20% THF by volume is required to obtain 100% end-capping free from side reactions. When too little or no THF was present, side reactions such as lithium halogen exchange followed by Wurtz coupling resulted in unfunctionalized head-to-head dimer as well as other byproducts. Modeling and simulation of the solvent effects using hybrid methods (the so-called QM/MM method) suggest that THF effectively dissociated the anionic chain-end aggregation, thereby resulting in the desired primary amine functionalized polymer. Molecular dynamics (MD) simulations were conducted to develop an understanding of the physics of counterions involved in the end-functionalization process.

  12. Formation of polar ring galaxies

    E-Print Network [OSTI]

    F. Bournaud; F. Combes

    2003-02-04T23:59:59.000Z

    Polar ring galaxies are peculiar systems in which a gas rich, nearly polar ring surrounds an early-type or elliptical host galaxy. Two formation scenarios for these objects have been proposed: they are thought to form either in major galaxy mergers or by tidal accretion of the polar material from a gas rich donor galaxy. Both scenarios are studied through N-body simulations including gas dynamics and star formation. Constraints on physical parameters are drawn out, in order to determine which scenario is the most likely to occur. Polar ring galaxies from each scenario are compared with observations and we discuss whether the accretion scenario and the merging scenario account for observational properties of polar ring galaxies. The conclusion of this study is that the accretion scenario is both the most likely and the most supported by observations. Even if the merging scenario is rather robust, most polar ring galaxies are shown to be the result of tidal gas accretion events.

  13. Rapid gas hydrate formation process

    DOE Patents [OSTI]

    Brown, Thomas D.; Taylor, Charles E.; Unione, Alfred J.

    2013-01-15T23:59:59.000Z

    The disclosure provides a method and apparatus for forming gas hydrates from a two-phase mixture of water and a hydrate forming gas. The two-phase mixture is created in a mixing zone which may be wholly included within the body of a spray nozzle. The two-phase mixture is subsequently sprayed into a reaction zone, where the reaction zone is under pressure and temperature conditions suitable for formation of the gas hydrate. The reaction zone pressure is less than the mixing zone pressure so that expansion of the hydrate-forming gas in the mixture provides a degree of cooling by the Joule-Thompson effect and provides more intimate mixing between the water and the hydrate-forming gas. The result of the process is the formation of gas hydrates continuously and with a greatly reduced induction time. An apparatus for conduct of the method is further provided.

  14. Efficiencies of Low-Mass Star and Star Cluster Formation

    E-Print Network [OSTI]

    Christopher D. Matzner; Christopher F. McKee

    2000-07-25T23:59:59.000Z

    Using a quantitative model for bipolar outflows driven by hydromagnetic protostellar winds, we calculate the efficiency of star formation assuming that available gas is either converted into stars or ejected in outflows. We estimate the efficiency of a single star formation event in a protostellar core, finding 25%-70% for cores with various possible degrees of flattening. The core mass function and the stellar initial mass function have similar slopes, because the efficiency is not sensitive to its parameters. We then consider the disruption of gas from a dense molecular clump in which a cluster of young stars is being born. In both cases, we present analytical formulae for the efficiencies that compare favorably against observations and, for clusters, against numerical simulations. We predict efficiencies in the range 30%-50% for the regions that form clusters of low-mass stars. In our model, star formation and gas dispersal happen concurrently. We neglect the destructive effects of massive stars: our results are therefore upper limits to the efficiency in regions more massive than about 3000 Msun.

  15. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    SciTech Connect (OSTI)

    Ernest A. Mancini

    2001-09-14T23:59:59.000Z

    The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 1 of the project has been reservoir description and characterization. This effort has included four tasks: (1) geoscientific reservoir characterization, (2) the study of rock-fluid interactions, (3) petrophysical and engineering characterization and (4) data integration. This work was scheduled for completion in Year 1. Overall, the project work is on schedule. Geoscientific reservoir characterization is essentially completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions has been initiated. Observations regarding the diagenetic processes influencing pore system development and heterogeneity in these reef and shoal reservoirs have been made. Petrophysical and engineering property characterization is progressing. Data on reservoir production rate and pressure history at Appleton and Vocation Fields have been tabulated, and porosity data from core analysis has been correlated with porosity as observed from well log response. Data integration is on schedule, in that, the geological, geophysical, petrophysical and engineering data collected to date for Appleton and Vocation Fields have been compiled into a fieldwide digital database for reservoir characterization, modeling and simulation for the reef and carbonate shoal reservoirs for each of these fields.

  16. The Formation of the Hubble Sequence

    E-Print Network [OSTI]

    Christopher J. Conselice

    2003-12-12T23:59:59.000Z

    The history of galaxy formation via star formation and stellar mass assembly rates is now known with some certainty, yet the connection between high redshift and low redshift galaxy populations is not yet clear. By identifying and studying individual massive galaxies at high-redshifts, z > 1.5, we can possibly uncover the physical effects driving galaxy formation. Using the structures of high-z galaxies, as imaged with the Hubble Space Telescope, we argue that it is now possible to directly study the progenitors of ellipticals and disks. We also briefly describe early results that suggest many massive galaxies are forming at z > 2 through major mergers.

  17. Stochastic opinion formation in scale-free networks

    SciTech Connect (OSTI)

    M. Bartolozzi; D. B. Leinweber; A. W. Thomas

    2005-10-01T23:59:59.000Z

    The dynamics of opinion formation in large groups of people is a complex nonlinear phenomenon whose investigation is just beginning. Both collective behavior and personal views play an important role in this mechanism. In the present work we mimic the dynamics of opinion formation of a group of agents, represented by two states 1, as a stochastic response of each agent to the opinion of his/her neighbors in the social network and to feedback from the average opinion of the whole. In the light of recent studies, a scale-free Barabsi-Albert network has been selected to simulate the topology of the interactions. A turbulent-like dynamics, characterized by an intermittent behavior, is observed for a certain range of the model parameters. The problem of uncertainty in decision taking is also addressed both from a topological point of view, using random and targeted removal of agents from the network, and by implementing a three-state model, where the third state, zero, is related to the information available to each agent. Finally, the results of the model are tested against the best known network of social interactions: the stock market. A time series of daily closures of the Dow-Jones index has been used as an indicator of the possible applicability of our model in the financial context. Good qualitative agreement is found.

  18. Maximization of permanent trapping of CO{sub 2} and co-contaminants in the highest-porosity formations of the Rock Springs Uplift (Southwest Wyoming): experimentation and multi-scale modeling

    SciTech Connect (OSTI)

    Piri, Mohammad

    2014-03-31T23:59:59.000Z

    Under this project, a multidisciplinary team of researchers at the University of Wyoming combined state-of-the-art experimental studies, numerical pore- and reservoir-scale modeling, and high performance computing to investigate trapping mechanisms relevant to geologic storage of mixed scCO{sub 2} in deep saline aquifers. The research included investigations in three fundamental areas: (i) the experimental determination of two-­?phase flow relative permeability functions, relative permeability hysteresis, and residual trapping under reservoir conditions for mixed scCO{sub 2}-­?brine systems; (ii) improved understanding of permanent trapping mechanisms; (iii) scientifically correct, fine grid numerical simulations of CO{sub 2} storage in deep saline aquifers taking into account the underlying rock heterogeneity. The specific activities included: (1) Measurement of reservoir-­?conditions drainage and imbibition relative permeabilities, irreducible brine and residual mixed scCO{sub 2} saturations, and relative permeability scanning curves (hysteresis) in rock samples from RSU; (2) Characterization of wettability through measurements of contact angles and interfacial tensions under reservoir conditions; (3) Development of physically-­?based dynamic core-­?scale pore network model; (4) Development of new, improved high-­? performance modules for the UW-­?team simulator to provide new capabilities to the existing model to include hysteresis in the relative permeability functions, geomechanical deformation and an equilibrium calculation (Both pore-­? and core-­?scale models were rigorously validated against well-­?characterized core-­? flooding experiments); and (5) An analysis of long term permanent trapping of mixed scCO{sub 2} through high-­?resolution numerical experiments and analytical solutions. The analysis takes into account formation heterogeneity, capillary trapping, and relative permeability hysteresis.

  19. Joint Radial Inversion of Resistivity and Sonic Logs to Estimate In-Situ Petrophysical and Elastic Properties of Formations

    E-Print Network [OSTI]

    Torres-Verdín, Carlos

    in the frequency domain. Synthetic cases consider water-base mud filtrate invading a hydrocarbon-bearing sand-wellbore damage, resulting from drilling and mud-filtrate invasion, can substantially affect sonic and resistivity, with the formation model described by a radial variation of water and hydrocarbon saturations representative of mud

  20. Sensitivity and Scenario Results

    E-Print Network [OSTI]

    Yu, Winston

    Presents the results of various scenarios using models used to study water, climate, agriculture and the economy in Pakistan's Indus Basin, and discusses the policy and investment implications. The water allocations per ...

  1. 41EurASEAA 2006, Bougon papers Natural processes iNvolved iN the formatioN of

    E-Print Network [OSTI]

    Boyer, Edmond

    site formation processes. A sedimentological study indicated that the fossiliferous layer resulted from

  2. Gas Cooling Through Galaxy Formations

    E-Print Network [OSTI]

    Mariwan A. Rasheed; Mohamad A. Brza

    Abstract-- Gas cooling was studied in two different boxes of sizes and by simulation at same redshifts. The gas cooling is shown in four different redshifts (z=1.15, 0.5, 0.1 and 0). In the simulation the positions of the clumps of cooled gas were studied with slices of the two volumes and also the density of cooled gas of the two volumes shown in the simulation. From the process of gas cooling it is clear that this process gives different results in the two cases. Index Term- Gas Cooling, Simulation, galaxy Formation. I.

  3. JPEG File Interchange Format

    E-Print Network [OSTI]

    Hamilton, Eric

    2004-03-30T23:59:59.000Z

    interchange format compressed image representation • PC or Mac or Unix workstation compatible • Standard color space: one or three components. For three components, YCbCr (CCIR 601-256 levels) • APP0 marker used to specify Units, X pixel density, Y pixel... by the Macintosh but not by PCs or workstations. JPEG File Interchange Format, Version 1.02 2 Standard color space The color space to be used is YCbCr as defined by CCIR 601 (256 levels). The RGB components calculated by linear conversion from YCbCr shall...

  4. On the formation of massive stellar clusters

    E-Print Network [OSTI]

    Tenorio-Tagle, G; Silich, S A; Medina-Tanco, G A; Muñoz-Tunón, C; Tenorio-Tagle, Guillermo; Palous, Jan; Silich, Sergiy; Medina-Tanco, Gustavo A.; Munoz-Tunon, Casiana

    2003-01-01T23:59:59.000Z

    Here we model a star forming factory in which the continuous creation of stars results in a highly concentrated, massive (globular cluster-like) stellar system. We show that under very general conditions a large-scale gravitational instability in the ISM, which triggers the collapse of a massive cloud, leads with the aid of a spontaneous first generation of massive stars, to a standing, small-radius, cold and dense shell. Eventually, as more of the collapsing matter is processed and incorporated, the shell becomes gravitationally unstable and begins to fragment, allowing the formation of new stars, while keeping its location. This is due to a detailed balance established between the ram pressure from the collapsing cloud which, together with the gravitational force exerted on the shell by the forming cluster, acts against the mechanical energy deposited by the collection of new stars. We analyze the mass spectrum of fragments that result from the continuous fragmentation of the standing shell and show that it...

  5. Liquid drops on a surface: using density functional theory to calculate the binding potential and drop profiles and comparing with results from mesoscopic modelling

    E-Print Network [OSTI]

    Adam P. Hughes; Uwe Thiele; Andrew J. Archer

    2015-01-28T23:59:59.000Z

    The contribution to the free energy for a film of liquid of thickness $h$ on a solid surface, due to the interactions between the solid-liquid and liquid-gas interfaces is given by the binding potential, $g(h)$. The precise form of $g(h)$ determines whether or not the liquid wets the surface. Note that differentiating $g(h)$ gives the Derjaguin or disjoining pressure. We develop a microscopic density functional theory (DFT) based method for calculating $g(h)$, allowing us to relate the form of $g(h)$ to the nature of the molecular interactions in the system. We present results based on using a simple lattice gas model, to demonstrate the procedure. In order to describe the static and dynamic behaviour of non-uniform liquid films and drops on surfaces, a mesoscopic free energy based on $g(h)$ is often used. We calculate such equilibrium film height profiles and also directly calculate using DFT the corresponding density profiles for liquid drops on surfaces. Comparing quantities such as the contact angle and also the shape of the drops, we find good agreement between the two methods. We also study in detail the effect on $g(h)$ of truncating the range of the dispersion forces, both those between the fluid molecules and those between the fluid and wall. We find that truncating can have a significant effect on $g(h)$ and the associated wetting behaviour of the fluid.

  6. Fluctuations and Correlations of net baryon number, electric charge, and strangeness: A comparison of lattice QCD results with the hadron resonance gas model

    E-Print Network [OSTI]

    A. Bazavov; Tanmoy Bhattacharya; C. E. DeTar; H. -T. Ding; Steven Gottlieb; Rajan Gupta; P. Hegde; Urs Heller; F. Karsch; E. Laermann; L. Levkova; Swagato Mukherjee; P. Petreczky; Christian Schmidt; R. A. Soltz; W. Soeldner; R. Sugar; Pavlos M. Vranas

    2012-08-11T23:59:59.000Z

    We calculate the quadratic fluctuations of net baryon number, electric charge and strangeness as well as correlations among these conserved charges in (2+1)-flavor lattice QCD at zero chemical potential. Results are obtained using calculations with tree level improved gauge and the highly improved staggered quark (HISQ) actions with almost physical light and strange quark masses at three different values of the lattice cut-off. Our choice of parameters corresponds to a value of 160 MeV for the lightest pseudo scalar Goldstone mass and a physical value of the kaon mass. The three diagonal charge susceptibilities and the correlations among conserved charges have been extrapolated to the continuum limit in the temperature interval 150 MeV net baryon number fluctuations in QCD agree with HRG model calculations while, the net electric charge fluctuations in QCD are about 10% smaller and net strangeness fluctuations are about 20% larger. These findings are relevant to the discussion of freeze-out conditions in relativistic heavy ion collisions.

  7. CGILS: Results from the First Phase of an International Project to Understand the Physical Mechanisms of Low Cloud Feedbacks in Single Column Models

    SciTech Connect (OSTI)

    Zhang, Minghua; Bretherton, Christopher S.; Blossey, Peter; Austin, Phillip A.; Bacmeister, J.; Bony, Sandrine; Brient, Florent; Cheedela, Suvarchal K.; Cheng, Anning; Del Genio, Anthony D.; De Roode, Stephan R.; Endo , Satoshi; Franklin, Charmaine N.; Golaz, Jean-Christophe; Hannay, Cecile; Heus, Thijs; Isotta, Francesco A.; Jean-Louis, Dufresne; Kang, In-Sik; Kawai, Hideaki; Koehler, M.; Larson, Vincent E.; Liu, Yangang; Lock, Adrian; Lohmann, U.; Khairoutdinov, Marat; Molod, Andrea M.; Neggers, Roel; Rasch, Philip J.; Sandu, Irina; Senkbeil, Ryan; Siebesma, A. P.; Siegenthaler-Le Drian, Colombe; Stevens, Bjorn; Suarez, Max; Xu, Kuan-Man; Von Salzen, Knut; Webb, Mark; Wolf, Audrey; Zhao, M.

    2013-12-26T23:59:59.000Z

    Large Eddy Models (LES) and Single Column Models (SCM) are used in a surrogate climate change 101 to investigate the physical mechanism of low cloud feedbacks in climate models. Enhanced surface-102 driven boundary layer turbulence and shallow convection in a warmer climate are found to be 103 dominant mechanisms in SCMs.

  8. Hair follicle Formation of

    E-Print Network [OSTI]

    Chuong, Cheng-Ming

    Hair follicle Formation of new follicles Bud Healed skin Hair bulge Open wound Epidermis a b Dermis 1950s and help to explain the controversy. What is the origin of the cells that make up these new hair follicles? Are they derived from existing hair follicles located at the wound edge

  9. A model-data intercomparison of CO2 exchange across North America: Results from the North American Carbon Program Site Synthesis

    SciTech Connect (OSTI)

    Schwalm, C.R.; Williams, C.A.; Schaefer, K.; Anderson, R.; Arain, M.A.; Baker, I.; Black, T.A.; Chen, G.; Ciais, P.; Davis, K. J.; Desai, A. R.; Dietze, M.; Dragoni, D.; Fischer, M.L.; Flanagan, L.B.; Grant, R.F.; Gu, L.; Hollinger, D.; Izaurralde, R.C.; Kucharik, C.; Lafleur, P.M.; Law, B.E.; Li, L.; Li, Z.; Liu, S.; Lokupitiya, E.; Luo, Y.; Ma, S.; Margolis, H.; Matamala, R.; McCaughey, H.; Monson, R. K.; Oechel, W. C.; Peng, C.; Poulter, B.; Price, D.T.; Riciutto, D.M.; Riley, W.J.; Sahoo, A.K.; Sprintsin, M.; Sun, J.; Tian, H.; Tonitto, C.; Verbeeck, H.; Verma, S.B.

    2011-06-01T23:59:59.000Z

    Our current understanding of terrestrial carbon processes is represented in various models used to integrate and scale measurements of CO{sub 2} exchange from remote sensing and other spatiotemporal data. Yet assessments are rarely conducted to determine how well models simulate carbon processes across vegetation types and environmental conditions. Using standardized data from the North American Carbon Program we compare observed and simulated monthly CO{sub 2} exchange from 44 eddy covariance flux towers in North America and 22 terrestrial biosphere models. The analysis period spans {approx}220 site-years, 10 biomes, and includes two large-scale drought events, providing a natural experiment to evaluate model skill as a function of drought and seasonality. We evaluate models' ability to simulate the seasonal cycle of CO{sub 2} exchange using multiple model skill metrics and analyze links between model characteristics, site history, and model skill. Overall model performance was poor; the difference between observations and simulations was {approx}10 times observational uncertainty, with forested ecosystems better predicted than nonforested. Model-data agreement was highest in summer and in temperate evergreen forests. In contrast, model performance declined in spring and fall, especially in ecosystems with large deciduous components, and in dry periods during the growing season. Models used across multiple biomes and sites, the mean model ensemble, and a model using assimilated parameter values showed high consistency with observations. Models with the highest skill across all biomes all used prescribed canopy phenology, calculated NEE as the difference between GPP and ecosystem respiration, and did not use a daily time step.

  10. N-Body Simulation of Planetesimal Formation through Gravitational Instability of a Dust Layer in Laminar Gas Disk

    E-Print Network [OSTI]

    Michikoshi, Shugo; Inutsuka, Shu-ichiro

    2010-01-01T23:59:59.000Z

    We investigate the formation process of planetesimals from the dust layer by the gravitational instability in the gas disk using local $N$-body simulations. The gas is modeled as a background laminar flow. We study the formation process of planetesimals and its dependence on the strength of the gas drag. Our simulation results show that the formation process is divided into three stages qualitatively: the formation of wake-like density structures, the creation of planetesimal seeds, and their collisional growth. The linear analysis of the dissipative gravitational instability shows that the dust layer is secularly unstable although Toomre's $Q$ value is larger than unity. However, in the initial stage, the growth time of the gravitational instability is longer than that of the dust sedimentation and the decrease in the velocity dispersion. Thus, the velocity dispersion decreases and the disk shrinks vertically. As the velocity dispersion becomes sufficiently small, the gravitational instability finally become...

  11. Diffraction Results from CDF

    SciTech Connect (OSTI)

    Goulianos, Konstantin

    2012-04-01T23:59:59.000Z

    We present final results by the CDF II collaboration on diffractive W and Z production, report on the status of ongoing analyses on diffractive dijet production and on rapidity gaps between jets, and briefly summarize results obtained on exclusive production pointing to their relevance to calibrating theoretical models used to predict exclusive Higgs-boson production at the LHC.

  12. Star Formation History of Omega Centauri Imprinted in Elemental Abundance Patterns

    E-Print Network [OSTI]

    Takuji Tsujimoto; Toshikazu Shigeyama

    2003-02-15T23:59:59.000Z

    The star formation history of the globular cluster Omega Centauri is investigated in the context of an inhomogeneous chemical evolution model in which supernovae induce star formation. The proposed model explains recent observations for Omega Cen stars, and divides star formation into three epochs. At the end of the first epoch, ~ 70% of the gas was expelled by supernovae. AGB stars then supplied s-process elements to the remaining gas during the first interval of ~300 Myr. This explains the observed sudden increase in Ba/Fe ratios in Omega Cen stars at [Fe/H] ~ -1.6. Supernovae at the end of the second epoch were unable to expel the gas. Eventually, Type Ia supernovae initiated supernova-induced star formation, and remaining gas was stripped when the cluster passed through the newly formed disk of the Milky Way. The formation of Omega Cen is also discussed in the framework of globular cluster formation triggered by cloud-cloud collisions. In this scenario, the relative velocity of clouds in the collision determines the later chemical evolution in the clusters. A head-on collision of proto-cluster clouds with a low relative velocity would have converted less than 1% of gas into stars and promoted the subsequent chemical evolution by supernova-driven star formation. This is consistent with present observed form of Omega Cen. In contrast, the other Galactic globular clusters are expected to have formed from more intense head-on collisions, and the resultant clouds would have been too thin for supernovae to accumulate enough gas to form the next generation of stars. This explains the absence of chemical evolution in these other globular clusters.

  13. Multiphase Sequestration Geochemistry: Model for Mineral Carbonation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Multiphase Sequestration Geochemistry: Model for Mineral Carbonation. Multiphase Sequestration Geochemistry: Model for Mineral Carbonation. Abstract: Carbonation of formation...

  14. The star formation history inferred from long gamma-ray bursts with high pseudo-redshifts

    E-Print Network [OSTI]

    Tan, Wei-Wei; Yu, Yun-Wei

    2015-01-01T23:59:59.000Z

    By employing a simple semi-analytical star formation model where the formation rates of Population (Pop) I/II and III stars can be calculated, respectively, we account for the number distribution of gamma-ray bursts (GRBs) with high pseudo-redshifts that was derived from an empirical luminosity-indictor relationship. It is suggested that a considerable number of Pop III GRBs could exist in the present sample of Swift GRBs. By further combining the implication for the star formation history from the optical depth of the CMB photons, it is also suggested that only a very small fraction 0.6% of Pop III GRBs could have triggered the Swift BAT. These results could provide an useful basis for estimating future detectability of Pop III stars and their produced transient phenomena.

  15. Ion Beam Deposition of Thin Films: Growth Processes and Nanostructure Formation

    SciTech Connect (OSTI)

    Hofsaess, Hans C. [II. Physikalisches Institut, Universitaet Goettingen, Friedrich-Hund-Platz 1, D-37077 Goettingen (Germany)

    2004-12-01T23:59:59.000Z

    Ion beam deposition is a process far from thermodynamic equilibrium and is in particular suited to grow metastable thin films with diamond-like properties, such as tetrahedral amorphous carbon (ta-C) and cubic boron nitride (c-BN). In this contribution the atomistic description of the deposition and growth processes are reviewed and compared to experimental results, obtained from mass selected ion beam deposition. The focus will be set to the nucleation and growth processes of boron nitride as a model system for ion based thin film formation. Furthermore, recent examples for nanostructure formation in ion deposited compound thin films will be presented. Ion beam deposited metal-carbon nano-composite thin films exhibit a variety of different morphologies such as rather homogeneous nanocluster distributions embedded in an a-C matrix, but also the self-organized formation of nanoscale multilayer structures.

  16. Hydrogenation of Carbon Dioxide by Water: Alkali-Promoted Synthesis of Formate

    SciTech Connect (OSTI)

    Hrbek, J.; Hoffmann, F.M.; Yang, Y.; Paul, J.; White, M.G.

    2010-07-15T23:59:59.000Z

    Conversion of carbon dioxide utilizing protons from water decomposition is likely to provide a sustainable source of fuels and chemicals in the future. We present here a time-evolved infrared reflection absorption spectroscopy (IRAS) and temperature-programmed desorption (TPD) study of the reaction of CO{sub 2} + H{sub 2}O in thin potassium layers. Reaction at temperatures below 200 K results in the hydrogenation of carbon dioxide to potassium formate. Thermal stability of the formate, together with its sequential transformation to oxalate and to carbonate, is monitored and discussed. The data of this model study suggest a dual promoter mechanism of the potassium: the activation of CO{sub 2} and the dissociation of water. Reaction at temperatures above 200 K, in contrast, is characterized by the absence of formate and the direct reaction of CO{sub 2} to oxalate, due to a drastic reduction of the sticking coefficient of water at higher temperatures.

  17. The Formation and Fragmentation of Primordial Molecular Clouds

    E-Print Network [OSTI]

    Tom Abel; Greg L. Bryan; Michael L. Norman

    2000-02-07T23:59:59.000Z

    Many questions in physical cosmology regarding the thermal history of the intergalactic medium, chemical enrichment, reionization, etc. are thought to be intimately related to the nature and evolution of pregalactic structure. In particular the efficiency of primordial star formation and the primordial IMF are of special interest. We present results from high resolution three--dimensional adaptive mesh refinement simulations that follow the collapse of primordial molecular clouds and their subsequent fragmentation within a cosmologically representative volume. Comoving scales from 128 kpc down to 1 pc are followed accurately. Dark matter dynamics, hydrodynamics and all relevant chemical and radiative processes (cooling) are followed self-consistently for a cluster normalized CDM structure formation model. Primordial molecular clouds with ~10^5 solar masses are assembled by mergers of multiple objects that have formed hydrogen molecules in the gas phase with a fractional abundance of ~10^-4. As the subclumps merge cooling lowers the temperature to ~200 Kelvin in a `cold pocket' at the center of the halo. Within this cold pocket, a quasi-hydrostatically contracting core with ~200 solar mass and number densities > 10^5 cm^-3 is found. We find that less than 1% of the primordial gas in such small scale structures cools and collapses to sufficiently high densities to be available for primordial star formation. Furthermore, it is worthwhile to note that this study achieved the highest dynamic range covered by structured adaptive mesh techniques in cosmological hydrodynamics to date.

  18. Possible influence of the two string events on the hadron formation in a nuclear environment

    E-Print Network [OSTI]

    N. Akopov; L. Grigoryan; Z. Akopov

    2007-05-07T23:59:59.000Z

    One of the basic assumptions of the string model is that as a result of a DIS in nucleus a single string arises, which then breaks into hadrons. However the pomeron exchange considered in this work, leads to the production of two strings in the one event. The hadrons produced in these events have smaller formation lengths, than those with the same energy produced in the single string events. As a consequence, they undergo more substantial absorption in the nuclear matter.

  19. Possible influence of the two string events on the hadron formation in a nuclear environment

    E-Print Network [OSTI]

    Akopov, N; Akopov, Z

    2007-01-01T23:59:59.000Z

    One of the basic assumptions of the string model is that as a result of a DIS in nucleus a single string arises, which then breaks into hadrons. However the pomeron exchange considered in this work, leads to the production of two strings in the one event. The hadrons produced in these events have smaller formation lengths, than those with the same energy produced in the single string events. As a consequence, they undergo more substantial absorption in the nuclear matter.

  20. Molecular Hydrogen Formation on Low Temperature Surfaces in Temperature Programmed Desorption Experiments

    E-Print Network [OSTI]

    G. Vidali; V. Pirronello; L. Li; J. Roser; G. Manico; R. Mehl; A. Lederhendler; H. B. Perets; J. R. Brucato; O. Biham

    2008-11-21T23:59:59.000Z

    The study of the formation of molecular hydrogen on low temperature surfaces is of interest both because it allows to explore elementary steps in the heterogeneous catalysis of a simple molecule and because of the applications in astrochemistry. Here we report results of experiments of molecular hydrogen formation on amorphous silicate surfaces using temperature-programmed desorption (TPD). In these experiments beams of H and D atoms are irradiated on the surface of an amorphous silicate sample. The desorption rate of HD molecules is monitored using a mass spectrometer during a subsequent TPD run. The results are analyzed using rate equations and the activation energies of the processes leading to molecular hydrogen formation are obtained from the TPD data. We show that a model based on a single isotope provides the correct results for the activation energies for diffusion and desorption of H atoms. These results can thus be used to evaluate the formation rate of H_2 on dust grains under the actual conditions present in interstellar clouds.

  1. Downscaling Global Land Cover Projections from an Integrated Assessment Model for Use in Regional Analyses: Results and Evaluation for the US from 2005 to 2095

    SciTech Connect (OSTI)

    West, Tristram O.; Le Page, Yannick LB; Huang, Maoyi; Wolf, Julie; Thomson, Allison M.

    2014-06-05T23:59:59.000Z

    Projections of land cover change generated from Integrated Assessment Models (IAM) and other economic-based models can be applied for analyses of environmental impacts at subregional and landscape scales. For those IAM and economic models that project land use at the sub-continental or regional scale, these projections must be downscaled and spatially distributed prior to use in climate or ecosystem models. Downscaling efforts to date have been conducted at the national extent with relatively high spatial resolution (30m) and at the global extent with relatively coarse spatial resolution (0.5 degree).

  2. Lisburne Formation fracture characterization and flow modeling

    E-Print Network [OSTI]

    Karpov, Alexandre Valerievich

    2001-01-01T23:59:59.000Z

    lead to exponential distrtbutions; multiplicatory processes as they occur in breakage lead 10 to lognormal distributions; and continuity of the process from smallest to largest sizes produces hyperbolic (fractal) distributions. However, a rigorous... of fractures on related outcrops was in the range of 1, 6-1. 8. Brock (1971) stated an important rule of thumb of fractal studies: the linearity on the double logarithmic plot should extend over at least two or three orders of naagnitude ol particle size...

  3. Search results | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Search results Search results Enter terms Search Showing 11 - 20 of 12 results. Download Solar Cell Simulation Students model the flow of energy from the sun as it enters a...

  4. (Non) formation of methanol by direct hydrogenation of formate on copper catalysts

    SciTech Connect (OSTI)

    Yang, Yong; Mims, Charles A.; Disselkamp, Robert S.; Kwak, Ja Hun; Peden, Charles HF; Campbell, C. T.

    2010-10-14T23:59:59.000Z

    We have attempted to hydrogenate adsorbed formate species on copper catalysts to probe the importance of this postulated mechanistic step in methanol synthesis. Surface formate coverages up to 0.25 were produced at temperatures between 413K and 453K on supported (Cu/SiO2) copper and unsupported copper catalysts. The adlayers were produced by various methods including (1) steady state catalytic conditions in CO2-H2 (3:1, 6 bar) atmospheres, and (2) by exposure of the catalysts to formic acid. As reported in earlier work, the catalytic surface at steady state contains bidentate formate species with coverages up to saturation levels of ~ 0.25 at the low temperatures of this study. The reactivity of these formate adlayers was investigated at relevant reaction temperatures in atmospheres containing up to 6 bar H2 partial pressure by simultaneous mass spectrometry (MS) and infrared (IR) spectroscopy measurements. The yield of methanol during the attempted hydrogenation (“titration”) of these adlayers was insignificant (<0.2 mol % of the formate adlayer) even in dry hydrogen partial pressures up to 6 bar. Hydrogen titration of formate species produced from formic acid also failed to produce significant quantities of methanol, and attempted titration in gases consisting of CO-hydrogen mixtures or dry CO2 were also unproductive. The formate decomposition kinetics, measured by IR, were also unaffected by these changes in the gas composition. Similar experiments on unsupported copper also failed to show any methanol. From these results, we conclude that methanol synthesis on copper cannot result from the direct hydrogenation of (bidentate) formate species in simple steps involving adsorbed H species alone. Furthermore, experiments performed on both supported (Cu/SiO2) and unsupported copper catalysts gave similar results implying that the methanol synthesis reaction mechanism only involves metal surface chemistry. Pre-exposure of the bidentate formate adlayer to oxidation by O2 or N2O produces a change to a monodentate configuration. Attempted titration of this monodentate formate/O coadsorbed layer in dry hydrogen produces significant quantities of methanol, although decomposition of formate to carbon dioxide and hydrogen remains the dominant reaction pathway. Simultaneous production of water is also observed during this titration as the copper surface is re-reduced. These results indicate that co-adsorbates related to surface oxygen or water-derived species may be critical to methanol production on copper, perhaps assisting in the hydrogenation of adsorbed formate to adsorbed methoxyl.

  5. Star formation bursts in isolated spiral galaxies

    E-Print Network [OSTI]

    C. Clarke; D. Gittins

    2006-07-03T23:59:59.000Z

    We study the response of the gaseous component of a galactic disc to the time dependent potential generated by N-body simulations of a spiral galaxy. The results show significant variation of the spiral structure of the gas which might be expected to result in significant fluctuations in the Star Formation Rate (SFR). Pronounced local variations of the SFR are anticipated in all cases. Bursty histories for the global SFR, however, require that the mean surface density is much less (around an order of magnitude less) than the putative threshold for star formation. We thus suggest that bursty star formation histories, normally attributed to mergers and/or tidal interactions, may be a normal pattern for gas poor isolated spiral galaxies.

  6. Formation of Cyanoformaldehyde in the interstellar space

    E-Print Network [OSTI]

    Das, Ankan; Chakrabarti, Sandip K; Saha, Rajdeep; Chakrabarti, Sonali

    2013-01-01T23:59:59.000Z

    Cyanoformaldehyde (HCOCN) molecule has recently been suspected towards the Sagittarius B2(N) by the Green Bank telescope, though a confirmation of this observation has not yet been made. In and around a star forming region, this molecule could be formed by the exothermic reaction between two abundant interstellar species, H$_2$CO and CN. Till date, the reaction rate coefficient for the formation of this molecule is unknown. Educated guesses were used to explain the abundance of this molecule by chemical modeling. In this paper, we carried out quantum chemical calculations to find out empirical rate coefficients for the formation of HCOCN and different chemical properties during the formation of HCOCN molecules. Though HCOCN is stable against unimolecular decomposition, this gas phase molecule could be destroyed by many other means, like: ion-molecular reactions or by the effect of cosmic rays. Ion-molecular reaction rates are computed by using the capture theories. We have also included the obtained rate coef...

  7. Data from selected Almond Formation outcrops -- Sweetwater County, Wyoming

    SciTech Connect (OSTI)

    Jackson, S.R.; Rawn-Schatzinger, V.

    1993-12-01T23:59:59.000Z

    The objectives of this research program are to: (1) determine the reservoir characteristics and production problems of shoreline barrier reservoirs; and (2) develop methods and methodologies to effectively characterize shoreline barrier reservoirs to predict flow patterns of injected and produced fluids. Two reservoirs were selected for detailed reservoir characterization studies -- Bell Creek field, Carter County, Montana, that produces from the Lower Cretaceous (Albian-Cenomanian) Muddy Formation, and Patrick Draw field, Sweetwater County, Wyoming that produces from the Upper Cretaceous (Campanian) Almond Formation of the Mesaverde Group. An important component of the research project was to use information from outcrop exposures of the producing formations to study the spatial variations of reservoir properties and the degree to which outcrop information can be used in the construction of reservoir models. A report similar to this one presents the Muddy Formation outcrop data and analyses performed in the course of this study (Rawn-Schatzinger, 1993). Two outcrop localities, RG and RH, previously described by Roehler (1988) provided good exposures of the Upper Almond shoreline barrier facies and were studied during 1990--1991. Core from core well No. 2 drilled approximately 0.3 miles downdip of outcrop RG was obtained for study. The results of the core study will be reported in a separate volume. Outcrops RH and RG, located about 2 miles apart were selected for detailed description and drilling of core plugs. One 257-ft-thick section was measured at outcrop RG, and three sections {approximately}145 ft thick located 490 and 655 feet apart were measured at the outcrop RH. Cross-sections of these described profiles were constructed to determine lateral facies continuity and changes. This report contains the data and analyses from the studied outcrops.

  8. Application of the CALIOP Layer Product to Evaluate the Vertical Distribution of Aerosols Estimated by Global Models: AeroCom Phase I Results

    SciTech Connect (OSTI)

    Koffi, Brigitte; Schultz, Michael; Breon, Francois-Marie; Griesfeller, Jan; Winker, D.; Balkanski, Y.; Bauer, Susanne E.; Berntsen, T.; Chin, Mian; Collins, William D.; Dentener, Frank; Diehl, Thomas; Easter, Richard C.; Ghan, Steven J.; Ginoux, P.; Gong, S.; Horowitz, L.; Iversen, T.; Kirkevag, A.; Koch, Dorothy; Krol, Maarten; Myhre, G.; Stier, P.; Takemura, T.

    2012-05-19T23:59:59.000Z

    The CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) layer product is used for a multimodel evaluation of the vertical distribution of aerosols. Annual and seasonal aerosol extinction profiles are analyzed over 13 sub-continental regions representative of industrial, dust, and biomass burning pollution, from CALIOP 2007-2009 observations and from AeroCom (Aerosol Comparisons between Observations and Models) 2000 simulations. An extinction mean height diagnostic (Z{sub a}) is defined to quantitatively assess the models performance. It is calculated over the 0-6 km and 0-10 km altitude ranges by weighting the altitude of each 100 m altitude layer by its aerosol extinction coefficient. The mean extinction profiles derived from CALIOP layer products provide consistent regional and seasonal specificities and a low inter-annual variability. While the outputs from most models are significantly correlated with the observed Z{sub a} climatologies, some do better than others, and 2 of the 12 models perform particularly well in all seasons. Over industrial and maritime regions, most models show higher Z{sub a} than observed by CALIOP, whereas over the African and Chinese dust source regions, Z{sub a} is underestimated during Northern Hemisphere Spring and Summer. The positive model bias in Z{sub a} is mainly due to an overestimate of the extinction above 6 km. Potential CALIOP and model limitations, and methodological factors that might contribute to the differences are discussed.

  9. The Complexity of Rationalizing Network Formation Shankar Kalyanaraman

    E-Print Network [OSTI]

    Umans, Chris

    and the Inequality-SAT (I-SAT) problem. Finally and most significantly, we prove that an approximation version. Keywords-network formation games, rationalization, Jackson- Wolinsky model, Inequality-SAT, hardness

  10. On the formation of massive stellar clusters

    E-Print Network [OSTI]

    Guillermo Tenorio-Tagle; Jan Palous; Sergiy Silich; Gustavo A. Medina-Tanco; Casiana Munoz-Tunon

    2003-08-25T23:59:59.000Z

    Here we model a star forming factory in which the continuous creation of stars results in a highly concentrated, massive (globular cluster-like) stellar system. We show that under very general conditions a large-scale gravitational instability in the ISM, which triggers the collapse of a massive cloud, leads with the aid of a spontaneous first generation of massive stars, to a standing, small-radius, cold and dense shell. Eventually, as more of the collapsing matter is processed and incorporated, the shell becomes gravitationally unstable and begins to fragment, allowing the formation of new stars, while keeping its location. This is due to a detailed balance established between the ram pressure from the collapsing cloud which, together with the gravitational force exerted on the shell by the forming cluster, acts against the mechanical energy deposited by the collection of new stars. We analyze the mass spectrum of fragments that result from the continuous fragmentation of the standing shell and show that its shape is well approximated at the high mass end by a power law with slope -2.25, very close to the value that fits the universal IMF. The self-contamination resultant from the continuous generation of stars is shown to lead to a large metal spread in massive ($\\sim$ 10$^6$ M$_\\odot$) clusters, while clusters with a mass similar to 10$^5$ M$_\\odot$ or smaller, simply reflect the initial metalicity of the collapsing cloud. This is in good agreement with the data available for globular clusters in the Galaxy.

  11. The Formation and Evolution of Prestellar Cores

    E-Print Network [OSTI]

    Philippe André; Shantanu Basu; Shu-ichiro Inutsuka

    2008-01-28T23:59:59.000Z

    Improving our understanding of the initial conditions and earliest stages of star formation is crucial to gain insight into the origin of stellar masses, multiple systems, and protoplanetary disks. We review the properties of low-mass dense cores as derived from recent millimeter/submillimeter observations of nearby molecular clouds and discuss them in the context of various contemporary scenarios for cloud core formation and evolution. None of the extreme scenarios can explain all observations. Pure laminar ambipolar diffusion has relatively long growth times for typical ionization levels and has difficulty satisfying core lifetime constraints. Purely hydrodynamic pictures have trouble accounting for the inefficiency of core formation and the detailed velocity structure of individual cores. A possible favorable scenario is a mixed model involving gravitational fragmentation of turbulent molecular clouds close to magnetic criticality. The evolution of the magnetic field and angular momentum in individual cloud cores after the onset of gravitational collapse is also discussed. In particular, we stress the importance of radiation-magnetohydrodynamical processes and resistive MHD effects during the protostellar phase. We also emphasize the role of the formation of the short-lived first (protostellar) core in providing a chance for sub-fragmentation into binary systems and triggering MHD outflows. Future submillimeter facilities such as Herschel and ALMA will soon provide major new observational constraints in this field. On the theoretical side, an important challenge for the future will be to link the formation of molecular clouds and prestellar cores in a coherent picture.

  12. The Razor's Edge: Magnetic Fields and Their Fundamental Role in Star Formation and Observations of Protostellar Coress

    E-Print Network [OSTI]

    Glenn E. Ciolek; Shantanu Basu

    2000-09-18T23:59:59.000Z

    We review theoretical models of the early stages of star formation, in which gravitational collapse is strongly regulated by magnetic fields and the associated process of ambipolar diffusion. We discuss results of numerical simulations and analytical studies of core formation and collapse, which can be directly tested against observation. We also focus on recent data which are relevant to this theory of star formation, such as: observations of extended infall in protostellar cores, estimates of evolutionary timescales ~ 1 Myr for cores, measured mass-to-flux ratios of cores, and the relative alignment of polarization vectors with apparent cloud elongation. It is shown that in all of these areas, the data lie within the observationally allowable range of parameter space. Other areas of interest (protostellar accretion rates and the presence of core edges) and issues that remain unresolved or under study (the role of non-thermal motions and cluster formation) are also discussed. Moreover, we highlight some differences between our model predictions and those of highly turbulent star formation models, and discuss how these differences can be distinguished observationally.

  13. Design study of the geometry of the blanking tool to predict the burr formation of Zircaloy-4 sheet

    SciTech Connect (OSTI)

    Ha, Jisun, E-mail: nskim@sogang.ac.kr; Lee, Hyungyil, E-mail: nskim@sogang.ac.kr; Kim, Dongchul, E-mail: nskim@sogang.ac.kr; Kim, Naksoo, E-mail: nskim@sogang.ac.kr [Sogang University, Department of Mechanical Engineering, Seoul, 121-742 (Korea, Republic of)

    2013-12-16T23:59:59.000Z

    In this work, we investigated factors that influence burr formation for zircaloy-4 sheet used for spacer grids of nuclear fuel roads. Factors we considered are geometric factors of punch. We changed clearance and velocity in order to consider the failure parameters, and we changed shearing angle and corner radius of L-shaped punch in order to consider geometric factors of punch. First, we carried out blanking test with failure parameter of GTN model using L-shaped punch. The tendency of failure parameters and geometric factors that affect burr formation by analyzing sheared edges is investigated. Consequently, geometric factor's influencing on the burr formation is also high as failure parameters. Then, the sheared edges and burr formation with failure parameters and geometric factors is investigated using FE analysis model. As a result of analyzing sheared edges with the variables, we checked geometric factors more affect burr formation than failure parameters. To check the reliability of the FE model, the blanking force and the sheared edges obtained from experiments are compared with the computations considering heat transfer.

  14. Local and Global Radiative Feedback from Population III Star Formation

    E-Print Network [OSTI]

    O'Shea, Brian W

    2010-01-01T23:59:59.000Z

    We present an overview of recent work that focuses on understanding the radiative feedback processes that are potentially important during Population III star formation. Specifically, we examine the effect of the Lyman-Werner (photodissociating) background on the early stages of primordial star formation, which serves to delay the onset of star formation in a given halo but never suppresses it entirely. We also examine the effect that both photodissociating and ionizing radiation in I-fronts from nearby stellar systems have on the formation of primordial protostellar clouds. Depending on the strength of the incoming radiation field and the central density of the halos, Pop III star formation can be suppressed, unaffected, or even enhanced. Understanding these and other effects is crucial to modeling Population III star formation and to building the earliest generations of galaxies in the Universe.

  15. Planning and Search Exam format

    E-Print Network [OSTI]

    Alechina, Natasha

    is the frame problem. Revision 5 #12;Exam topics: planning Classical planning. How the problem definitionPlanning and Search Revision Revision 1 #12;Outline Exam format Exam topics How to revise Revision 2 #12;Exam format 4 questions out of 6 same format as 2010-2011 and 2011-2012 exams (on G52PAS

  16. Numerical Simulation of Bubble Formation in Co-Flowing Mercury

    SciTech Connect (OSTI)

    Abdou, Ashraf A [ORNL; Wendel, Mark W [ORNL; Felde, David K [ORNL; Riemer, Bernie [ORNL

    2008-01-01T23:59:59.000Z

    In this work, we present computational fluid dynamics (CFD) simulations of helium bubble formation and detachment at a submerged needle in stagnant and co-flowing mercury. Since mercury is opaque, visualization of internal gas bubbles was done with proton radiography (pRad) at the Los Alamos Neutron Science Center (LANSCE2). The acoustic waves emitted at the time of detachment and during subsequent oscillations of the bubble were recorded with a microphone. The Volume of Fluid (VOF) model was used to simulate the unsteady two-phase flow of gas injection in mercury. The VOF model is validated by comparing detailed bubble sizes and shapes at various stages of the bubble growth and detachment, with the experimental measurements at different gas flow rates and mercury velocities. The experimental and computational results show a two-stage bubble formation. The first stage involves growing bubble around the needle, and the second follows as the buoyancy overcomes wall adhesion. The comparison of predicted and measured bubble sizes and shapes at various stages of the bubble growth and detachment is in good agreement.

  17. Dynamical Treatment of Virialization Heating in Galaxy Formation

    E-Print Network [OSTI]

    Peng Wang; Tom Abel

    2007-09-11T23:59:59.000Z

    In a hierarchical picture of galaxy formation virialization continually transforms gravitational potential energy into kinetic energies of the baryonic and dark matter. For the gaseous component the kinetic, turbulent energy is transformed eventually into internal thermal energy through shocks and viscous dissipation. Traditionally this virialization and shock heating has been assumed to occur instantaneously allowing an estimate of the gas temperature to be derived from the the virial temperature defined from the embedding dark matter halo velocity dispersion. As the mass grows the virial temperature of a halo grows. Mass accretion hence can be translated into a heating term. We derive this heating rate from the extended Press Schechter formalism and demonstrate its usefulness in semi-analytical models of galaxy formation. Our method explicitly conserves energy unlike the previous impulsive heating assumptions. Our formalism can trivially be applied in all current semi-analytical models as the heating term can be computed directly from the underlying merger trees. Our analytic results for the first cooling halos and the transition from cold to hot accretion are in agreement with numerical simulations.

  18. Where the Blue Stragglers Roam: Searching for a Link Between Formation and Environment

    E-Print Network [OSTI]

    Nathan Leigh; Alison Sills; Christian Knigge

    2008-08-15T23:59:59.000Z

    The formation of blue stragglers is still not completely understood, particularly the relationship between formation environment and mechanism. We use a large, homogeneous sample of blue stragglers in the cores of 57 globular clusters to investigate the relationships between blue straggler populations and their environments. We use a consistent definition of "blue straggler" based on position in the color-magnitude diagram, and normalize the population relative to the number of red giant branch stars in the core. We find that the previously determined anti-correlation between blue straggler frequency and total cluster mass is present in the purely core population. We find some weak correlations with central velocity dispersion and with half-mass relaxation time. The blue straggler frequency does not show any trend with any other cluster parameter. Even though collisions may be expected to be a dominant blue straggler formation process in globular cluster cores, we find no correlation between the frequency of blue stragglers and the collision rate in the core. We also investigated the blue straggler luminosity function shape, and found no relationship between any cluster parameter and the distribution of blue stragglers in the color-magnitude diagram. Our results are inconsistent with some recent models of blue straggler formation that include collisional formation mechanisms, and may suggest that almost all observed blue stragglers are formed in binary systems.

  19. Galactosynthesis: Halo Histories, Star Formation, and Disks

    E-Print Network [OSTI]

    Ari Buchalter; Raul Jimenez; Marc Kamionkowski

    2000-06-01T23:59:59.000Z

    We investigate the effects of a variety of ingredients that must enter into a realistic model for disk-galaxy formation, focusing primarily on the Tully-Fisher (TF) relation and its scatter in several wavebands. Our main findings are: (a) the slope, normalization, and scatter of the TF relation across various wavebands is determined {\\em both} by halo properties and star formation in the disk; (b) TF scatter owes primarily to the spread in formation redshifts. The scatter can be measurably reduced by chemical evolution, and also in some cases by the weak anti-correlation between peak height and spin; (c) multi-wavelength constraints can be important in distinguishing between models which appear to fit the TF relation in I or K; (d) successful models seem to require that the bulk of disk formation cannot occur too early (z>2) or too late (z<0.5), and are inconsistent with high values of $\\Omega_0$; (e) a realistic model with the above ingredients can reasonably reproduce the observed z=0 TF relation in {\\em all} bands (B, R, I, and K). It can also account for the z=1 B-band TF relation and yield rough agreement with the local B and K luminosity functions and B-band surface-brightness--magnitude relation. The remarkable agreement with observations suggests that the amount of gas that is expelled or poured into a disk galaxy must be small, and that the specific angular momentum of the baryons must roughly equal that of the halo; there is little room for angular momentum transfer. In an appendix we present analytic fits to stellar-population synthesis models.

  20. Rapid Formation of Gas Giant Planets around M Dwarf Stars

    E-Print Network [OSTI]

    Alan P. Boss

    2006-01-20T23:59:59.000Z

    Extrasolar planet surveys have begun to detect gas giant planets in orbit around M dwarf stars. While the frequency of gas giant planets around M dwarfs so far appears to be lower than that around G dwarfs, it is clearly not zero. Previous work has shown that the core accretion mechanism does not seem to be able to form gas giant planets around M dwarfs, because the time required for core formation scales with the orbital period, which lengthens for lower mass stars, resulting in failed (gas-poor) cores unless the gaseous protoplanetary disk survives for > 10 Myr. Disk instability, on the other hand, is rapid enough (~ 1000 yrs) that it should be able to form gas giant protoplanets around even low mass stars well before the gaseous disk disappears. A new suite of three dimensional radiative, gravitational hydrodynamical models is presented that calculates the evolution of initially marginally gravitationally unstable disks with masses of 0.021 to 0.065 solar masses orbiting around stars with masses of 0.1 and 0.5 solar masses, respectively. The models show that gas giant planets are indeed likely to form by the disk instability mechanism in orbit around M dwarf stars, the opposite of the prediction for formation by the core accretion mechanism. This difference offers another observational test for discriminating between these two theoretical end members for giant planet formation. Ongoing and future extrasolar planet searches around M dwarfs by spectroscopy, microlensing, photometry, and astrometry offer the opportunity to help decide between the dominance of the two mechanisms.

  1. Physical Constraints on Geologic CO2 Sequestration in Low-Volume Basalt Formations

    SciTech Connect (OSTI)

    Ryan M. Pollyea; Jerry P. Fairley; Robert K. Podgorney; Travis L. McLing

    2014-03-01T23:59:59.000Z

    Deep basalt formations within large igneous provinces have been proposed as target reservoirs for carbon capture and sequestration on the basis of favorable CO2-water-rock reaction kinetics that suggest carbonate mineralization rates on the order of 102–103 d. Although these results are encouraging, there exists much uncertainty surrounding the influence of fracture-controlled reservoir heterogeneity on commercial-scale CO2 injections in basalt formations. This work investigates the physical response of a low-volume basalt reservoir to commercial-scale CO2 injections using a Monte Carlo numerical modeling experiment such that model variability is solely a function of spatially distributed reservoir heterogeneity. Fifty equally probable reservoirs are simulated using properties inferred from the deep eastern Snake River Plain aquifer in southeast Idaho, and CO2 injections are modeled within each reservoir for 20 yr at a constant mass rate of 21.6 kg s–1. Results from this work suggest that (1) formation injectivity is generally favorable, although injection pressures in excess of the fracture gradient were observed in 4% of the simulations; (2) for an extensional stress regime (as exists within the eastern Snake River Plain), shear failure is theoretically possible for optimally oriented fractures if Sh is less than or equal to 0.70SV; and (3) low-volume basalt reservoirs exhibit sufficient CO2 confinement potential over a 20 yr injection program to accommodate mineral trapping rates suggested in the literature.

  2. Survival of interstellar molecules to prestellar dense core collapse and early phases of disk formation

    E-Print Network [OSTI]

    Hincelin, Ugo; Commerçon, Benoît; Hersant, Franck; Guilloteau, Stéphane

    2013-01-01T23:59:59.000Z

    An outstanding question of astrobiology is the link between the chemical composition of planets, comets and other Solar System bodies and the molecules formed in the interstellar medium. Understanding the chemical and physical evolution of the matter leading to the formation of protoplanetary disks is an important step for this. We bring some new stones to this longstanding problem using three-dimensional chemical simulations of the early phases of disk formation: we interfaced the full gas-grain chemical model Nautilus with the radiation-magneto-hydrodynamic model RAMSES, for different configurations and intensities of magnetic field. Our results show that the chemical content (gas and ices) is globally conserved during the collapsing process, from the parent molecular cloud to the young disk surrounding the first Larson core. A qualitative comparison with cometary composition suggests that comets are constituted of different phases, some molecules being direct tracers of interstellar chemistry, while others...

  3. Warm intermediate inflation in the Randall-Sundrum II model in the light of Planck 2015 and BICEP2 results: A general dissipative coefficient

    E-Print Network [OSTI]

    Herrera, Ramón; Olivares, Marco

    2015-01-01T23:59:59.000Z

    A warm inflationary Universe in the Randall-Sundrum II model during intermediate inflation is studied. For this purpose, we consider a general form for the dissipative coefficient $\\Gamma(T,\\phi)=C_{\\phi}\\,\\frac{T^{m}}{\\phi^{m-1}}$, and also analyze this inflationary model in the weak and strong dissipative regimes. We study the evolution of the Universe under the slow-roll approximation and find solutions to the full effective Friedmann equation in the brane-world framework. In order to constrain the parameters in our model, we consider the recent data from the BICEP2-Planck 2015 data together with the necessary condition for warm inflation $T>H$, and also the condition from the weak (or strong) dissipative regime.

  4. Warm intermediate inflation in the Randall-Sundrum II model in the light of Planck 2015 and BICEP2 results: A general dissipative coefficient

    E-Print Network [OSTI]

    Ramón Herrera; Nelson Videla; Marco Olivares

    2015-04-28T23:59:59.000Z

    A warm inflationary Universe in the Randall-Sundrum II model during intermediate inflation is studied. For this purpose, we consider a general form for the dissipative coefficient $\\Gamma(T,\\phi)=C_{\\phi}\\,\\frac{T^{m}}{\\phi^{m-1}}$, and also analyze this inflationary model in the weak and strong dissipative regimes. We study the evolution of the Universe under the slow-roll approximation and find solutions to the full effective Friedmann equation in the brane-world framework. In order to constrain the parameters in our model, we consider the recent data from the BICEP2-Planck 2015 data together with the necessary condition for warm inflation $T>H$, and also the condition from the weak (or strong) dissipative regime.

  5. Formation, characterization and reactivity of adsorbed oxygen...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Formation, characterization and reactivity of adsorbed oxygen on BaOPt(111). Formation, characterization and reactivity of adsorbed oxygen on BaOPt(111). Abstract: The formation...

  6. The Efficiency of Globular Cluster Formation

    E-Print Network [OSTI]

    Dean E. McLaughlin

    1999-01-21T23:59:59.000Z

    (Abridged): The total populations of globular cluster systems (GCSs) are discussed in terms of their connection to the efficiency of globular cluster formation---the mass fraction of star-forming gas that was able to form bound stellar clusters rather than isolated stars or unbound associations---in galaxy halos. Observed variations in GCS specific frequencies (S_N=N_gc/L_gal), both as a function of galactocentric radius in individual systems and globally between entire galaxies, are reviewed in this light. It is argued that trends in S_N do not reflect any real variation in the underlying efficiency of cluster formation; rather, they result from ignoring the hot gas in many large ellipticals. This claim is checked and confirmed in each of M87, M49, and NGC 1399, for which existing data are combined to show that the volume density profile of globular clusters, rho_cl, is directly proportional to the sum of (rho_gas+rho_stars) at large radii. The constant of proportionality is the same in each case: epsilon=0.0026 +/- 0.0005 in the mean. This is identified with the globular cluster formation efficiency. The implication that epsilon might have had a universal value is supported by data on the GCSs of 97 early-type galaxies, on the GCS of the Milky Way, and on the ongoing formation of open clusters. These results have specific implications for some issues in GCS and galaxy formation, and they should serve as a strong constraint on more general theories of star and cluster formation.

  7. RESRAD-BUILD: A computer model for analyzing the radiological doses resulting from the remediation and occupancy of buildings contaminated with radioactive material

    SciTech Connect (OSTI)

    Yu, C.; LePoire, D.J.; Jones, L.G. [and others

    1994-11-01T23:59:59.000Z

    The RESRAD-BUILD computer code is a pathway analysis model designed to evaluate the potential radiological dose incurred by an individual who works or lives in a building contaminated with radioactive material. The transport of radioactive material inside the building from one compartment to another is calculated with an indoor air quality model. The air quality model considers the transport of radioactive dust particulates and radon progeny due to air exchange, deposition and resuspension, and radioactive decay and ingrowth. A single run of the RESRAD-BUILD code can model a building with up to: three compartments, 10 distinct source geometries, and 10 receptor locations. A shielding material can be specified between each source-receptor pair for external gamma dose calculations. Six exposure pathways are considered in the RESRAD-BUILD code: (1) external exposure directly from the source; (2) external exposure to materials deposited on the floor; (3) external exposure due to air submersion; (4) inhalation of airborne radioactive particulates; (5) inhalation of aerosol indoor radon progeny; and (6) inadvertent ingestion of radioactive material, either directly from the sources or from materials deposited on the surfaces of the building compartments. 4 refs., 23 figs., 4 tabs.

  8. Search results | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Enter terms Search Showing 21 - 30 of 34 results. Download Modeling the Process of Mining Silicon Through a Single DisplacementRedox Reaction As the popularity of photovoltaic...

  9. Search results | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Enter terms Search Showing 31 - 40 of 32 results. Download Modeling the Process of Mining Silicon Through a Single DisplacementRedox Reaction As the popularity of photovoltaic...

  10. Search results | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Enter terms Search Showing 21 - 30 of 23 results. Download Modeling the Process of Mining Silicon Through a Single DisplacementRedox Reaction As the popularity of photovoltaic...

  11. Search results | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Enter terms Search Showing 21 - 30 of 25 results. Download Modeling the Process of Mining Silicon Through a Single DisplacementRedox Reaction As the popularity of photovoltaic...

  12. Search results | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Enter terms Search Showing 31 - 40 of 35 results. Download Modeling the Process of Mining Silicon Through a Single DisplacementRedox Reaction As the popularity of photovoltaic...

  13. Search results | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Enter terms Search Showing 1 - 1 of 1 result. Download The BEAM Project: Building Efficient Architectural Models This activity allows students the opportunity to explore...

  14. Step- vs. kink-formation energies on Pt(111)

    SciTech Connect (OSTI)

    FEIBELMAN,PETER J.

    2000-05-01T23:59:59.000Z

    Ab-initio kink-formation energies are about 0.25 and 0.18 eV on the (100)- and (111)-microfacet steps of Pt(111), while the sum of the step-formation energies is 0.75 eV/atom. These results imply a specific ratio of formation energies for the two step types, namely 1.14, in excellent agreement with experiment. If kink-formation costs the same energy on the two step types, an inference recently drawn from scanning probe observations of step wandering, this ratio ought to be 1.

  15. Dissipation, noise and DCC domain formation

    E-Print Network [OSTI]

    A. K. Chaudhuri

    1999-08-17T23:59:59.000Z

    We investigate the effect of friction on domain formation in disoriented chiral condensate. We solve the equation of motion of the linear sigma model, in the Hartree approximation, including a friction and a white noise term. For quenched initial condition, we find that even in presence of noise and dissipation domain like structure emerges after a few fermi of evolution. Domain size as large as 5 fm can be formed.

  16. Reservoir architecture modeling: Nonstationary models for quantitative geological characterization. Final report, April 30, 1998

    SciTech Connect (OSTI)

    Kerr, D.; Epili, D.; Kelkar, M.; Redner, R.; Reynolds, A.

    1998-12-01T23:59:59.000Z

    The study was comprised of four investigations: facies architecture; seismic modeling and interpretation; Markov random field and Boolean models for geologic modeling of facies distribution; and estimation of geological architecture using the Bayesian/maximum entropy approach. This report discusses results from all four investigations. Investigations were performed using data from the E and F units of the Middle Frio Formation, Stratton Field, one of the major reservoir intervals in the Gulf Coast Basin.

  17. FORMULATION OF NON-STEADY-STATE DUST FORMATION PROCESS IN ASTROPHYSICAL ENVIRONMENTS

    SciTech Connect (OSTI)

    Nozawa, Takaya [Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Kozasa, Takashi, E-mail: takaya.nozawa@ipmu.jp [Department of Cosmosciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan)

    2013-10-10T23:59:59.000Z

    The non-steady-state formation of small clusters and the growth of grains accompanied by chemical reactions are formulated under the consideration that the collision of key gas species (key molecule) controls the kinetics of dust formation process. The formula allows us to evaluate the size distribution and condensation efficiency of dust formed in astrophysical environments. We apply the formulation to the formation of C and MgSiO{sub 3} grains in the ejecta of supernovae, as an example, to investigate how the non-steady effect influences the formation process, condensation efficiency f{sub con,{sub ?}}, and average radius a{sub ave,{sub ?}} of newly formed grains in comparison with the results calculated with the steady-state nucleation rate. We show that the steady-state nucleation rate is a good approximation if the collision timescale of key molecule ?{sub coll} is much smaller than the timescale ?{sub sat} with which the supersaturation ratio increases; otherwise the effect of the non-steady state becomes remarkable, leading to a lower f{sub con,{sub ?}} and a larger a{sub ave,{sub ?}}. Examining the results of calculations, we reveal that the steady-state nucleation rate is applicable if the cooling gas satisfies ? ? ?{sub sat}/?{sub coll} ?> 30 during the formation of dust, and find that f{sub con,{sub ?}} and a{sub ave,{sub ?}} are uniquely determined by ?{sub on} at the onset time t{sub on} of dust formation. The approximation formulae for f{sub con,{sub ?}} and a{sub ave,{sub ?}} as a function of ?{sub on} could be useful in estimating the mass and typical size of newly formed grains from observed or model-predicted physical properties not only in supernova ejecta but also in mass-loss winds from evolved stars.

  18. Formation of Nuclear Disks and Supermassive Black Hole Binaries in Multi-Scale Hydrodynamical Galaxy Mergers

    E-Print Network [OSTI]

    Lucio Mayer; Stelios Kazantzidis; Andres Escala

    2008-07-22T23:59:59.000Z

    (Abridged) We review the results of the first multi-scale, hydrodynamical simulations of mergers between galaxies with central supermassive black holes (SMBHs) to investigate the formation of SMBH binaries in galactic nuclei. We demonstrate that strong gas inflows produce nuclear disks at the centers of merger remnants whose properties depend sensitively on the details of gas thermodynamics. In numerical simulations with parsec-scale spatial resolution in the gas component and an effective equation of state appropriate for a starburst galaxy, we show that a SMBH binary forms very rapidly, less than a million years after the merger of the two galaxies. Binary formation is significantly suppressed in the presence of a strong heating source such as radiative feedback by the accreting SMBHs. We also present preliminary results of numerical simulations with ultra-high spatial resolution of 0.1 pc in the gas component. These simulations resolve the internal structure of the resulting nuclear disk down to parsec scales and demonstrate the formation of a central massive object (~ 10^8 Mo) by efficient angular momentum transport. This is the first time that a radial gas inflow is shown to extend to parsec scales as a result of the dynamics and hydrodynamics involved in a galaxy merger, and has important implications for the fueling of SMBHs. Due to the rapid formation of the central clump, the density of the nuclear disk decreases significantly in its outer region, reducing dramatically the effect of dynamical friction and leading to the stalling of the two SMBHs at a separation of ~1 pc. We discuss how the orbital decay of the black holes might continue in a more realistic model which incorporates star formation and the multi-phase nature of the ISM.

  19. CONSTRAINTS ON THE FORMATION OF THE PLANET IN HD 188753 Hannah Jang-Condell

    E-Print Network [OSTI]

    for planet formation. In this paper we attempt to model a protoplanetary disk around HD 188753A using around an iso- lated star, these models provide good fits to observed spectral energy distributions (SEDs that planet formation cannot occur in the more quiescent -disk model puts a strong constraint on planet

  20. Controls on H sub 2 concentration and hydrocarbon destruction in Smackover Formation, southwest Alabama

    SciTech Connect (OSTI)

    Wade, W.J.; Hanor, J.S.; Sassen, R. (Louisiana State Univ., Baton Rouge (USA))

    1989-09-01T23:59:59.000Z

    H{sub 2}S generated by thermal sulfate reduction and oxidation of hydrocarbons in deeply-buried Smackover reservoirs is preferentially destroyed by reaction with metal ions to form sulfide minerals in the underlying Norphlet Formation. Resulting H{sub 2}S concentrations differences can be described by calculated molecular diffusion profiles within the Smackover Formation. Theoretical H{sub 2}S diffusion coefficients extrapolated for 45 Alabama Smackover fields and measured H{sub 2}s concentrations from those fields are in agreement with model steady-state profiles. Factors controlling reservoir H{sub 2}S concentration in this model are porosity, permeability, tortuosity, and thickness of the Smackover Formation. Lesser factors are nature of pore phase (oil, gas, or formation water), temperature (in excess of critical reaction temperature), and pressure. Although calculated H{sub 2}S diffusion profiles can successfully describe or predict H{sub 2}S concentration gradients, rates of molecular diffusion are insufficient to account for observed reservoir concentrations of H{sub 2}S. It is thus probable that advective dispersion resulting from convective overturn is the means by which the inferred steady-state profiles are maintained. The rate of destruction of hydrocarbons by thermal sulfate reduction is partly dependent on H{sub 2}S flux, which may be estimated from the H{sub 2}S concentration gradient, convection rate, and temperature. Economic basement for Smackover reservoirs therefore varies. Reliable estimates of porosity, permeability, and thickness trends allow (1) prediction of H{sub 2}S concentrations in the Smackover Formation with reasonable accuracy, and (2) estimation of local economic basement for Smackover reservoirs.

  1. Search results | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    results Enter terms Search Showing 1 - 1 of 1 result. Download Modeling the Process of Mining Silicon Through a Single DisplacementRedox Reaction As the popularity of photovoltaic...

  2. Search results | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Search results Enter terms Search Showing 41 - 50 of 42 results. Download Solar Cell Simulation Students model the flow of energy from the sun as it enters a photovoltaic...

  3. Search results | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Search results Enter terms Search Showing 51 - 60 of 53 results. Download Solar Cell Simulation Students model the flow of energy from the sun as it enters a photovoltaic...

  4. Computational social network modeling of terrorist recruitment.

    SciTech Connect (OSTI)

    Berry, Nina M.; Turnley, Jessica Glicken (Sandia National Laboratories, Albuquerque, NM); Smrcka, Julianne D. (Sandia National Laboratories, Albuquerque, NM); Ko, Teresa H.; Moy, Timothy David (Sandia National Laboratories, Albuquerque, NM); Wu, Benjamin C.

    2004-10-01T23:59:59.000Z

    The Seldon terrorist model represents a multi-disciplinary approach to developing organization software for the study of terrorist recruitment and group formation. The need to incorporate aspects of social science added a significant contribution to the vision of the resulting Seldon toolkit. The unique addition of and abstract agent category provided a means for capturing social concepts like cliques, mosque, etc. in a manner that represents their social conceptualization and not simply as a physical or economical institution. This paper provides an overview of the Seldon terrorist model developed to study the formation of cliques, which are used as the major recruitment entity for terrorist organizations.

  5. Lithium abundances in exoplanet host stars as test of planetary formation scenarii

    E-Print Network [OSTI]

    M. Castro; O. Richard; S. Vauclair

    2005-10-20T23:59:59.000Z

    Following the observations of Israelian et al. 2004, we compare different evolutionary models in order to study the lithium destruction processes and the planetary formation scenarii.

  6. Chemical Accelerator Studies of Isotope Effects on Collision Dynamics of Ion–Molecule Reactions: Elaboration of a Model for Direct Reactions

    E-Print Network [OSTI]

    Hierl, Peter M.; Herman, Z.; Wolfgang, R.

    1970-01-01T23:59:59.000Z

    there is a fairly wide distribution about the median values. Results confirm that this reaction is predominantly direct at all energies and provide no evidence for intermediate persistent complex formation. They are also consistent with a model for direct...

  7. FORMATION OF ORGANIC MOLECULES AND WATER IN WARM DISK ATMOSPHERES

    SciTech Connect (OSTI)

    Najita, Joan R. [National Optical Astronomy Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 (United States); Adamkovics, Mate; Glassgold, Alfred E. [Astronomy Department, University of California, Berkeley, CA 94720 (United States)

    2011-12-20T23:59:59.000Z

    Observations from Spitzer and ground-based infrared spectroscopy reveal significant diversity in the molecular emission from the inner few AU of T Tauri disks. We explore theoretically the possible origin of this diversity by expanding on our earlier thermal-chemical model of disk atmospheres. We consider how variations in grain settling, X-ray irradiation, accretion-related mechanical heating, and the oxygen-to-carbon ratio can affect the thermal and chemical properties of the atmosphere at 0.25-40 AU. We find that these model parameters can account for many properties of the detected molecular emission. The column density of the warm (200-2000 K) molecular atmosphere is sensitive to grain settling and the efficiency of accretion-related heating, which may account, at least in part, for the large range in molecular emission fluxes that have been observed. The dependence of the atmospheric properties on the model parameters may also help to explain trends that have been reported in the literature between molecular emission strength and mid-infrared color, stellar accretion rate, and disk mass. We discuss whether some of the differences between our model results and the observations (e.g., for water) indicate a role for vertical transport and freezeout in the disk midplane. We also discuss how planetesimal formation in the outer disk (beyond the snowline) may imprint a chemical signature on the inner few AU of the disk and speculate on possible observational tracers of this process.

  8. Kinetics of the smectite to illite transformation in the Denver Basin: Clay mineral, K-Ar data, and mathematical model results

    SciTech Connect (OSTI)

    Elliot, W.C.; Aronson, J.L.; Matisoff, G. (Case Western Reserve Univ., Cleveland, OH (United States)); Gautier, D.L. (Geological Survey, Denver, CO (United States))

    1991-03-01T23:59:59.000Z

    Clay mineral data, potassium-argon (K-Ar) ages, and mathematical model simulations indicate the important kinetic factors controlling the smectite to illite transformation (illitization) in Upper Cretaceous Mowry and Niobrara core and outcrop bentonites from the Denver basin. The data also provide additional information on the thermal history of the basin. Data show that both the percentages of illite layers and the K-Ar ages of mixed layer illite-smectite (I/S) increase with increasing depths of burial, and this trend was simulated mathematically employing a very simplified burial model with a fifth-order overall kinetic expression for the information of illite. For most of the basin, the data is compatible with I/S having been formed in response to increased temperature from progressive burial, because the oldest K-Ar ages of I/S are from the deepest buried I/S along the basin axis. In addition, these data qualitatively suggest that I/S even as small as <0.1 {mu}m retains radiogenic argon under Denver basin burial temperatures. I/S separated from drill core bentonites from the Watenberg gas field, astride the basin axis and known to have been subjected to an anomalously high temperature history, are the most illitic and among the oldest measured from core in this study. The ages of illitization (about 60 Ma) are coincident with the Laramide time of structural development of the basin and uplift of the Front Range. The reconstructions of the burial history, and the modeling of the timing and extent of illitization, suggest that the area of the Wattenberg as field was an upper Cretaceous depocenter, an area of relatively deeper burial along the basin axis.

  9. Characterising the acceleration phase of blast wave formation

    SciTech Connect (OSTI)

    Fox, T. E., E-mail: tef503@york.ac.uk; Pasley, J. [York Plasma Institute, University of York, York YO10 5DD (United Kingdom); Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom); Robinson, A. P. L.; Schmitz, H. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom)

    2014-10-15T23:59:59.000Z

    Intensely heated, localised regions in uniform fluids will rapidly expand and generate an outwardly propagating blast wave. The Sedov-Taylor self-similar solution for such blast waves has long been studied and applied to a variety of scenarios. A characteristic time for their formation has also long been identified using dimensional analysis, which by its very nature, can offer several interpretations. We propose that, rather than simply being a characteristic time, it may be interpreted as the definitive time taken for a blast wave resulting from an intense explosion in a uniform media to contain its maximum kinetic energy. A scaling relation for this measure of the acceleration phase, preceding the establishment of the blast wave, is presented and confirmed using a 1D planar hydrodynamic model.

  10. FORMATION GESTION DU STRESS CONTEXTE, PUBLIC, FINALITE DE LA FORMATION

    E-Print Network [OSTI]

    Brest, Université de

    FORMATION GESTION DU STRESS CONTEXTE, PUBLIC, FINALITE DE LA FORMATION La vie moderne et le stress : mettre en place des stratégies de gestion , étudier quelques aspects essentiels de la et cas cliniques composés par les participants ou fournis par le formateur . - Jeux de rôle en sous

  11. Proposal to Acquire Experimental Data and to Model the Results with a Monte Carlo Calculation of a Secondary Source Correction Factor for Area Source Acquisitions of Holdup y-PHA Measurements

    SciTech Connect (OSTI)

    Dewberry, R.

    2003-02-10T23:59:59.000Z

    This report describes an interference observed when acquiring y-ray holdup data. The interference comes from secondary contaminated surfaces that contribute to the y-ray signal when acquiring data in the area source configuration. It is often the case that these unwanted contributions can not be isolated and eliminated, so it is necessary to mathematically correct for the contribution. In this report we propose experiments to acquire the necessary data to determine the experimental correction factor specifically for highly enriched uranium holdup measurements. We then propose to use the MCNP Monte Carlo computer code to model the contribution in several acquisition configurations and for multiple interfering y-ray energies. Results will provide a model for calculation of this secondary source correction factor for future holdup measurements. We believe the results of the experiments and modeling of the data acquired in this proposal will have a significant impact on deactivation and de commissioning activities throughout the DOE weapons complex.

  12. Evaluation of the Berea sandstone formation in eastern Pike County, Kentucky

    SciTech Connect (OSTI)

    Frantz, J.H. Jr. (S.A. Holditch Associates, Inc., Pittsburgh, PA (United States)); Luffel, D. (ResTech Houston, Inc., Houston, TX (United States)); Kubik, W. (K A Energy Consultants, Tulsa, OK (United States))

    1993-08-01T23:59:59.000Z

    The Gas Research Institute (GRI) has been sponsoring a cooperative well program with Ashland Exploration, Inc., (AEI) during the past two years targeting the Devonian Shale and Berea sandstone formations in Pike County of eastern Kentucky. Operators typically complete both the shales and Berea in one well bore in this area. This presentation summarizes the research results of the Berea cooperative well, the COOP 2 (Ashland FMC 80). The specific objectives of the Berea evaluation in the COOP 2 were to develop an integrated reservoir description for stimulation design and predicting long-term well performance, identify geologic production controls, determine the in-situ stress profile, and develop Berea log interpretation models for gas porosity and stress. To satisfy these objectives, data were collected and analyzed from 146 ft of whole core, open-hole geophysical logs, including formation microscanner and digital sonic, in-situ stress measurements, and prefracture production and pressure transient tests. In addition, data from a minifracture, a fracture stimulation treatment, and postfracture performance tests were analyzed. The authors determined the integrated reservoir/hydraulic fracture descriptions from analyzing the data collected in the open- and cased-hole, in addition to the log interpretation models developed to accurately predict gas porosity and stress profiles. Results can be applied by operators to better understand the Berea reservoir in the study area, predict well performance, and design completion procedures and stimulation treatments. The methodology can also be applied to other tight-gas sand formations.

  13. Changes in the halo formation rates due to features in the primordial spectrum

    E-Print Network [OSTI]

    Dhiraj Kumar Hazra

    2013-02-07T23:59:59.000Z

    Features in the primordial scalar power spectrum provide a possible roadway to describe the outliers at the low multipoles in the WMAP data. Apart from the CMB angular power spectrum, these features can also alter the matter power spectrum and, thereby, the formation of the large scale structure. Carrying out a complete numerical analysis, we investigate the effects of primordial features on the formation rates of the halos. We consider a few different inflationary models that lead to features in the scalar power spectrum and an improved fit to the CMB data, and analyze the corresponding imprints on the formation of halos. Performing a Markov Chain Monte Carlo analysis with the WMAP seven year data and the SDSS halo power spectrum from LRG DR7 for the models of our interest, we arrive at the parameter space of the models allowed by the data. We illustrate that, inflationary potentials, such as the quadratic potential with sinusoidal modulations and the axion monodromy model, which generate certain repeated, oscillatory features in the inflationary perturbation spectrum, do not induce a substantial difference in the number density of halos at their best fit values, when compared with, say, a nearly scale invariant spectrum as is generated by the standard quadratic potential. However, we find that the number density and the formation rates of halos change by about 13-22% for halo masses ranging over 10^4-10^14 solar mass, for potential parameters that lie within 2-sigma around the best fit values arrived at from the aforesaid joint constraints. We briefly discuss the implications of our results.

  14. Early and Rapid Merging as a Formation Mechanism of Massive Galaxies: Empirical Constraints

    E-Print Network [OSTI]

    Christopher J. Conselice

    2005-10-30T23:59:59.000Z

    We present the results of a series of empirical computations regarding the role of major mergers in forming the stellar masses of modern galaxies based on measurements of galaxy merger and star formation histories from z~0.5-3. We re-construct the merger history of normal field galaxies from z~3 to z~0 as a function of initial mass using published pair fractions and merger fractions from structural analyses. We calibrate the observed merger time-scale and mass ratios for galaxy mergers using self-consistent N-body models of mergers, composed of dark matter and stars, with mass ratios from 1:1 to 1:5 with various orbital properties and viewing angles. We use these simulations to determine the time-scales and mass ratios that produce structures that would be identified as major mergers. Based on these calculations we argue that a typical massive galaxy at z~3 with M_{*} > 10^{10} M_0 undergoes 4.4^{+1.6}_{-0.9} major mergers at z > 1. We find that by z~1.5 the stellar mass of an average massive galaxy is relatively established, a scenario qualitatively favored in a lambda dominated universe. We argue that the final masses of these systems increases by as much as a factor of 100 allowing Lyman-break galaxies, which tend to have low stellar masses, to become the most massive galaxies in today's universe with M > M^{*}. Induced star formation however only accounts for 10-30% of the stellar mass formed in these galaxies at z < 3. A comparison to semi-analytic models of galaxy formation shows that Cold Dark Matter (CDM) models consistently under-predict the merger fraction, and rate of merging, of massive galaxies at high redshift. This suggests that massive galaxy formation occurs through more merging than predicted in CDM models, rather than a rapid early collapse.

  15. The Formation of Nuclear Rings in Barred Spiral Galaxies

    E-Print Network [OSTI]

    Michael W. Regan; Peter J. Teuben

    2002-10-10T23:59:59.000Z

    Although nuclear rings of gas and star formation are common in barred spiral galaxies, current theories of why and how they form do not provide the level of detail needed to quantify the effect that these rings can have on the fueling of active galactic nuclei and on the evolution of their host galaxy. In this paper we use detailed modeling to show that existence of nuclear rings is directly related to the existence of the orbit family whose major axis is perpendicular to the major axis of the bar (x_2). We explore a large range of barred galaxy potentials and for each potential we use a two-dimensional hydrodynamic simulation to determine whether and at what radius a nuclear ring forms. We compare the results of the hydrodynamic simulations to numerical integrations of periodic orbits in a barred potential and show that the rings only form when a minimum amount of x_2 orbits exists. Because the rings migrate inwards with time as they accumulate gas, the radius at which a nuclear ring is seen does not give direct information on the shape of the rotation curve. We also show that the common assumption that nuclear rings are related to an inner Lindblad resonance is incorrect. In fact, we show that there is no RESONANCE at the inner Lindblad resonance in barred galaxies. We also compare the predictions of this theory to HST observations and show that it correctly predicts the observed gas and star formation morphology of nuclear rings.

  16. Molecular Dynamics Simulations of CO2 Formation in Interstellar Ices

    E-Print Network [OSTI]

    Arasa, Carina; van Dishoeck, Ewine F; Kroes, Geert-Jan

    2013-01-01T23:59:59.000Z

    CO2 ice is one of the most abundant components in ice-coated interstellar ices besides H2O and CO, but the most favorable path to CO2 ice is still unclear. Molecular dynamics calculations on the ultraviolet photodissociation of different kinds of CO-H2O ice systems have been performed at 10 K in order to demonstrate that the reaction between CO and an OH molecule resulting from H2O photodissociation through the first excited state is a possible route to form CO2 ice. However, our calculations, which take into account different ice surface models, suggest that there is another product with a higher formation probability ((3.00+-0.07)x10-2), which is the HOCO complex, whereas the formation of CO2 has a probability of only (3.6+-0.7)x10-4. The initial location of the CO is key to obtain reaction and form CO2: the CO needs to be located deep into the ice. The HOCO complex becomes trapped in the cold ice surface in the trans-HOCO minimum because it quickly loses its internal energy to the surrounding ice, preventi...

  17. Star formation histories in early-type galaxies

    E-Print Network [OSTI]

    D. Thomas

    1998-08-24T23:59:59.000Z

    I discuss the formation of alpha-enhanced metal-rich stellar populations in the nuclei of luminous ellipticals. Based on hierarchical clustering, different galaxy formation scenarios, which imply different star formation histories, are considered. In contrast to the fast clumpy collapse mode, the late merger of two spiral galaxies fails to reproduce significantly $\\alpha$-enhanced abundance ratios, unless the IMF is flattened. Following the star formation history predicted by semi-analytic models of hierarchical clustering for the average elliptical, solar abundance ratios are obtained with Salpeter IMF. According to the models, bright ellipticals in the field are expected to have significantly lower Mg/Fe ratios than their counterparts in a cluster.

  18. DAMAGE AND ROCKVOLATILE MIXTURE EFFECTS ON IMPACT CRATER FORMATION

    E-Print Network [OSTI]

    Stewart, Sarah T.

    DAMAGE AND ROCK­VOLATILE MIXTURE EFFECTS ON IMPACT CRATER FORMATION JOHN D. O'KEEFE, SARAH T models for material damage, dilatancy, and inhomogeneous materials (mixtures). We found that a strength degradation (damage) model was necessary to produce faulting in homogeneous materials. Both normal and thrust

  19. Line formation in AGB atmospheres including velocity effects. Molecular line profile variations of long period variables

    E-Print Network [OSTI]

    Nowotny, W; Aringer, B

    2010-01-01T23:59:59.000Z

    The atmospheres of evolved red giants are considerably influenced by pulsations of the stellar interiors and developing stellar winds. The resulting complex velocity fields severely affect molecular line profiles observable in NIR spectra. With the help of model calculations the complex line formation process in AGB atmospheres was explored with the focus on velocity effects. Furthermore, we aimed for atmospheric models which are able to quantitatively reproduce line profile variations found in observed spectra of pulsating late-type giants. Models describing pulsation-enhanced dust-driven winds were used to compute synthetic spectra under the assumptions of chemical equilibrium and LTE and by solving the radiative transfer in spherical geometry including velocity effects. Radial velocities derived from Doppler-shifted synthetic line profiles provide information on the gas velocities in the line-forming region of the spectral features. On the basis of dynamic models we investigated in detail the finding that ...

  20. Formation depths of Fraunhofer lines

    E-Print Network [OSTI]

    Gurtovenko, E A

    2015-01-01T23:59:59.000Z

    We have summed up our investigations performed in 1970--1993. The main task of this paper is clearly to show processes of formation of spectral lines as well as their distinction by validity and by location. For 503 photospheric lines of various chemical elements in the wavelength range 300--1000 nm we list in Table the average formation depths of the line depression and the line emission for the line centre and on the half-width of the line, the average formation depths of the continuum emission as well as the effective widths of the layer of the line depression formation. Dependence of average depths of line depression formation on excitation potential, equivalent widths, and central line depth are demonstrated by iron lines.