Ocean General Circulation Models
Yoon, Jin-Ho; Ma, Po-Lun
2012-09-30T23:59:59.000Z
1. Definition of Subject The purpose of this text is to provide an introduction to aspects of oceanic general circulation models (OGCMs), an important component of Climate System or Earth System Model (ESM). The role of the ocean in ESMs is described in Chapter XX (EDITOR: PLEASE FIND THE COUPLED CLIMATE or EARTH SYSTEM MODELING CHAPTERS). The emerging need for understanding the Earth’s climate system and especially projecting its future evolution has encouraged scientists to explore the dynamical, physical, and biogeochemical processes in the ocean. Understanding the role of these processes in the climate system is an interesting and challenging scientific subject. For example, a research question how much extra heat or CO2 generated by anthropogenic activities can be stored in the deep ocean is not only scientifically interesting but also important in projecting future climate of the earth. Thus, OGCMs have been developed and applied to investigate the various oceanic processes and their role in the climate system.
Adaptive Grids for Atmospheric General Circulation Models
Jablonowski, Christiane
the wind speed OMEGA model Courtesy of A. Sarma (SAIC, NC, USA) #12;Two Adaptive Shallow Water Models AMR the vertical resolutions adds another factor of 2 We need to increase our computational power by a factor
Application of Improved Radiation Modeling to General Circulation Models
Michael J Iacono
2011-04-07T23:59:59.000Z
This research has accomplished its primary objectives of developing accurate and efficient radiation codes, validating them with measurements and higher resolution models, and providing these advancements to the global modeling community to enhance the treatment of cloud and radiative processes in weather and climate prediction models. A critical component of this research has been the development of the longwave and shortwave broadband radiative transfer code for general circulation model (GCM) applications, RRTMG, which is based on the single-column reference code, RRTM, also developed at AER. RRTMG is a rigorously tested radiation model that retains a considerable level of accuracy relative to higher resolution models and measurements despite the performance enhancements that have made it possible to apply this radiation code successfully to global dynamical models. This model includes the radiative effects of all significant atmospheric gases, and it treats the absorption and scattering from liquid and ice clouds and aerosols. RRTMG also includes a statistical technique for representing small-scale cloud variability, such as cloud fraction and the vertical overlap of clouds, which has been shown to improve cloud radiative forcing in global models. This development approach has provided a direct link from observations to the enhanced radiative transfer provided by RRTMG for application to GCMs. Recent comparison of existing climate model radiation codes with high resolution models has documented the improved radiative forcing capability provided by RRTMG, especially at the surface, relative to other GCM radiation models. Due to its high accuracy, its connection to observations, and its computational efficiency, RRTMG has been implemented operationally in many national and international dynamical models to provide validated radiative transfer for improving weather forecasts and enhancing the prediction of global climate change.
Robertson, Andrew W.
Solving Problems with GCMs: General Circulation Models and Their Role in the Climate Modeling of a hierarchy of models for solving problems in climate dynamics. General circulation models (GCMs) occupy, capture all the phenomena, and solve all the problems. Hence the concept of a hierarchy of climate models
''Nuclear Winter'': A diagnosis of atmospheric general circulation model simulations
Covey, C.; Thompson, S.L.; Schneider, S.H.
1985-06-20T23:59:59.000Z
We investigate the adiabatic and diabatic thermal balance of an atmospheric general circulation model (GCM) under two conditions: the control case, representing today's atmosphere, and a ''nuclear winter'' scenario in which virtually all sunlight in northern hemisphere and mid-latitudes is absorbed in the upper troposphere by prescribed dense smoke clouds hypothesized to result from the burning of many cities in a nuclear war. We also examine the changes in moisture and cloudiness simulated by the model. Our object is to examine the reliability of existing simulations of the climatic response to assumed dense, widespread, high-altitude smoke and to identify improvements needed in model parameterizations. We find that in the smoke-perturbed case our model simulation of land surface temperature is particularly influenced (i.e., warmed) by parameterized diffusion of heat downward from the lower troposphere. In turn the lower troposphere over land is supplied with heat transported from the relatively warm oceans. Thermal balance in the perturbed atmosphere as a whole is dominated by intense solar heating of the upper troposphere smoke layer in mid-latitudes balanced by parameterized dry convection and large-scale dynamical heat transport. Clouds largely disappear in the mid to upper troposphere in smoke-affected regions as a consequence of a decrease in local relative humidity that results from temperature increases and, to a smaller extent, from a reduction of vertical moisture transport. The computation of substantial downward vertical heat diffusion into the lowest model layer is almost certainly an overestimate for the smoke-perturbed conditions of high vertical stability.
Russell, Lynn
Geophysical Fluid Dynamics Laboratory general circulation model investigation of the indirect Corporation for Atmospheric Research, Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey, USA V. Ramaswamy, Paul A. Ginoux, and Larry W. Horowitz Geophysical Fluid Dynamics Laboratory, Princeton, New
The Effect of Topography on Storm-Track Intensity in a Relatively Simple General Circulation Model
Son, Seok-Woo
The Effect of Topography on Storm-Track Intensity in a Relatively Simple General Circulation Model The effect of topography on storm-track intensity is examined with a set of primitive equation model flow impinging on the topography. If the background flow consists of a weak double jet, higher
Fridlind, Ann
jcl92c.tex The Importance of Mesoscale Circulations Generated by SubgridScale Landscape Oceanography, Cook Campus, Rutgers University, New Brunswick, NJ 08903, USA. #12; Abstract A mesoscale. These results emphasize the need to parameterize mesoscale processes induced by landscape discontinuities
Burtis, M.D. [comp.] [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center; Razuvaev, V.N.; Sivachok, S.G. [All-Russian Research Inst. of Hydrometeorological Information--World Data Center, Obninsk (Russian Federation)
1996-10-01T23:59:59.000Z
This report presents English-translated abstracts of important Russian-language literature concerning general circulation models as they relate to climate change. Into addition to the bibliographic citations and abstracts translated into English, this report presents the original citations and abstracts in Russian. Author and title indexes are included to assist the reader in locating abstracts of particular interest.
Fesen, C.G. (Dartmouth College, Hanover, NH (United States)); Roble, R.G.; Ridley, E.C. (National Center for Atmospheric Research, Boulder, CO (United States))
1993-05-01T23:59:59.000Z
The authors use the National Center for Atmospheric Research (NCAR) thermosphere/ionosphere general circulation model (TIGCM) to model tides and dynamics in the thermosphere. This model incorporates the latest advances in the thermosphere general circulation model. Model results emphasized the 70[degree] W longitude region to overlap a series of incoherent radar scatter installations. Data and the model are available on data bases. The results of this theoretical modeling are compared with available data, and with prediction of more empirical models. In general there is broad agreement within the comparisons.
Kim, Joong Tae
2007-09-17T23:59:59.000Z
Open water in sea ice, such as leads and polynyas, plays a crucial role in determining the formation of deep- and bottom-water, as well as their long-term global properties and circulation. Ocean general circulation models (GCMs) designed...
Electrodynamic effects of thermospheric winds from the NCAR thermospheric general circulation model
Richmond, A.D.; Roble, R.G.
1987-11-01T23:59:59.000Z
The ionospheric electric fields and currents and the associated ground magnetic variations, generated by the dynamo action of winds simulated with the National Center for Atmospheric Research, Boulder, Colo. (NCAR) Thermospheric General Circulation Model (TGCM), are modelled and compared with observations for equinox solar minimum conditions. The dynamo model uses a tilted dipole geomagnetic field and allows for field-aligned current flow between conjugate points, but no magnetospheric dynamo effects are included. Two TGCM wind simulations are used, one of which is driven only by in situ solar ultraviolet heating and the other of which includes lower boundary forcing that mimics the effects of upward propagating semidiurnal tides, as described by Fesen et al. (1986). Without tidal forcing, the TGCM winds produce ground magnetic variations that have the general pattern of observed Sq variations but are only about half as strong.
Cintra, Rosangela S
2014-01-01T23:59:59.000Z
This paper presents an approach for employing artificial neural networks (NN) to emulate an ensemble Kalman filter (EnKF) as a method of data assimilation. The assimilation methods are tested in the Simplified Parameterizations PrimitivE-Equation Dynamics (SPEEDY) model, an atmospheric general circulation model (AGCM), using synthetic observational data simulating localization of balloon soundings. For the data assimilation scheme, the supervised NN, the multilayer perceptrons (MLP-NN), is applied. The MLP-NN are able to emulate the analysis from the local ensemble transform Kalman filter (LETKF). After the training process, the method using the MLP-NN is seen as a function of data assimilation. The NN were trained with data from first three months of 1982, 1983, and 1984. A hind-casting experiment for the 1985 data assimilation cycle using MLP-NN were performed with synthetic observations for January 1985. The numerical results demonstrate the effectiveness of the NN technique for atmospheric data assimilati...
Ocean mixed layer processes in the Pacific Decadal Oscillation in coupled general circulation models
Qiu, Bo
Ocean mixed layer processes in the Pacific Decadal Oscillation in coupled general circulation to be larger for CGCMs with a larger ocean heat transport in the region. Keywords Pacific Decadal Oscillation Á. 1994a, b; Zhanget al. 1996), ocean-atmosphere interactions over the North Pacific (e.g., Latif
Wan, Hui; Rasch, Philip J.; Zhang, Kai; Qian, Yun; Yan, Huiping; Zhao, Chun
2014-09-08T23:59:59.000Z
This paper explores the feasibility of an experimentation strategy for investigating sensitivities in fast components of atmospheric general circulation models. The basic idea is to replace the traditional serial-in-time long-term climate integrations by representative ensembles of shorter simulations. The key advantage of the proposed method lies in its efficiency: since fewer days of simulation are needed, the computational cost is less, and because individual realizations are independent and can be integrated simultaneously, the new dimension of parallelism can dramatically reduce the turnaround time in benchmark tests, sensitivities studies, and model tuning exercises. The strategy is not appropriate for exploring sensitivity of all model features, but it is very effective in many situations. Two examples are presented using the Community Atmosphere Model version 5. The first example demonstrates that the method is capable of characterizing the model cloud and precipitation sensitivity to time step length. A nudging technique is also applied to an additional set of simulations to help understand the contribution of physics-dynamics interaction to the detected time step sensitivity. In the second example, multiple empirical parameters related to cloud microphysics and aerosol lifecycle are perturbed simultaneously in order to explore which parameters have the largest impact on the simulated global mean top-of-atmosphere radiation balance. Results show that in both examples, short ensembles are able to correctly reproduce the main signals of model sensitivities revealed by traditional long-term climate simulations for fast processes in the climate system. The efficiency of the ensemble method makes it particularly useful for the development of high-resolution, costly and complex climate models.
Phillips, T J; Potter, G L; Williamson, D L; Cederwall, R T; Boyle, J S; Fiorino, M; Hnilo, J J; Olson, J G; Xie, S; Yio, J J
2004-05-06T23:59:59.000Z
To significantly improve the simulation of climate by general circulation models (GCMs), systematic errors in representations of relevant processes must first be identified, and then reduced. This endeavor demands that the GCM parameterizations of unresolved processes, in particular, should be tested over a wide range of time scales, not just in climate simulations. Thus, a numerical weather prediction (NWP) methodology for evaluating model parameterizations and gaining insights into their behavior may prove useful, provided that suitable adaptations are made for implementation in climate GCMs. This method entails the generation of short-range weather forecasts by a realistically initialized climate GCM, and the application of six-hourly NWP analyses and observations of parameterized variables to evaluate these forecasts. The behavior of the parameterizations in such a weather-forecasting framework can provide insights on how these schemes might be improved, and modified parameterizations then can be tested in the same framework. In order to further this method for evaluating and analyzing parameterizations in climate GCMs, the U.S. Department of Energy is funding a joint venture of its Climate Change Prediction Program (CCPP) and Atmospheric Radiation Measurement (ARM) Program: the CCPP-ARM Parameterization Testbed (CAPT). This article elaborates the scientific rationale for CAPT, discusses technical aspects of its methodology, and presents examples of its implementation in a representative climate GCM.
Gnanadesikan, Anand
shortwave penetration in the high-latitude Southern Ocean causes an increase in the formation of mode waterOcean Water Clarity and the Ocean General Circulation in a Coupled Climate Model ANAND GNANADESIKAN Jersey (Manuscript received 11 October 2007, in final form 17 July 2008) ABSTRACT Ocean water clarity
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.
Forced and free variations of the surface temperature field in a general circulation model
North, G.R.; Yip, K.J.J.; Laiyung Leung (Texas A M Univ., College Station (United States)); Chervin, R.M. (National Center for Atmospheric Research, Boulder, CO (United States))
1992-03-01T23:59:59.000Z
The concept of forced' and free' variations of large-scale surface temperature is examined by analyzing several long runs of the Community Climate Model (CCM0) with idealized boundary conditions and forcing. (1) The planet is all land with uniform sea-level topography and fixed soil moisture. (2) The planetary surface and prescribed ozone are reflection symmetric across the equator and there is no generation of snow. (3) The obliquity is set to zero so that the climate is for a perpetual equinox solar insolation (i.e., sun fixed over the equator). After examining some relevant aspects of the undisturbed climate (surface temperature field) such as temporal and spatial autocorrelations and the corresponding spectra, two types of changes in external forcing are imposed to study the model response: (1) sinusoidal changes of the solar constant (5%, 10%, 20%, and 40% amplitudes) at periods of 15 and 30 days (the latter is the autocorrelation time for the global average surface temperature) and 20% at 60 days and (2) insertion of steady heat sources (points and zonal bands) of variable strength at the surface. Then the temporal spectra of large scales for the periodically forced climate and the ensemble-averaged influence functions are examined for the point source disturbed climates. In each class of experiments the response of ensemble-averaged amplitudes was found to be proportional to the amplitude of the forcing. These results suggest that the lowest moments of the surface temperature field have a particularly simple dependence on forcing. Furthermore, the apparent finiteness of the variance spectrum at low frequencies suggest that estimates of long-term statistics are stable in this type of atmospheric general circulation model. 31 refs., 17 figs.
Shackley, Simon.; Risbey, James; Stone, Peter H.; Wynne, Brian
This paper surveys and interprets the attitudes of scientists to the use of flux adjustments in climate projections with coupled Atmosphere Ocean General Circulation Models. The survey is based largely on the responses of ...
Thompson, S.L.; Ramaswamy, V.; Covey, C.
1987-09-20T23:59:59.000Z
A global atmospheric general circulation model (GCM) is modified to include radiative transfer parameterizations for the absorption and scattering of solar radiation and the absorption of thermal infrared (IR) radiation by smoke aerosols. The solar scattering modifications include a parameterization for diagnosing smoke optical properties as a function of the time- and space-dependent smoke particle radii. The aerosol IR modifications allow for both the ''grey'' absorber approximation and a broadband approximation that resolves the aerosol absorption in four spectral intervals. We examine the sensitivity of some GCM-simulated atmospheric and climatic effects to the optical properties and radiative transfer parameterizations used in studies of massive injections of smoke. Specifically, we test the model response to solar scattering versus nonscattering smoke, variations in prescribed smoke single scattering albedo and IR specific absorption, and interactive versus fixed smoke optical properties. Hypothetical nuclear war created smoke scenarios assume the July injection of 60 or 180 Tg of smoke over portions of the mid-latitude land areas of the northern hemisphere. Atmospheric transport and scavenging of the smoke are included. Nonscattering smoke cases produce roughly 40 Wm/sup -2/ more Earth-atmosphere solar irradiance absorption over the northern hemisphere, when compared to scattering smoke cases having equivalent specific absorption efficiencies. Varying the elemental carbon content of smoke over a plausible range produces a 4/sup 0/--6 /sup 0/C change in average mid-latitude land surface temperature, and a variation of about 0.1 in zonally averaged planetary albedo in the northern hemisphere.
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...
Zalucha, Angela
2012-01-01T23:59:59.000Z
We present a 3D general circulation model of Pluto and Triton's atmospheres, which uses radiative-conductive-convective forcing. In both the Pluto and Triton models, an easterly (prograde) jet is present at the equator with a maximum magnitude of 10-12 m/s and 4 m/s, respectively. Neither atmosphere shows any significant overturning circulation in the meridional and vertical directions. Rather, it is horizontal motions (mean circulation and transient waves) that transport heat meridionally at a magnitude of 1 and 3 x 10^7 W at Pluto's autumn equinox and winter solstice, respectively (seasons referenced to the Northern Hemisphere). The meridional and dayside-nightside temperature contrast is small (<5 K). We find that the lack of vertical motion can be explained on Pluto by the strong temperature inversion in the lower atmosphere. The height of the Voyager 2 plumes on Triton can be explained by the dynamical properties of the lower atmosphere alone (i.e., strong wind shear) and does not require a thermally ...
USE OF GENERAL CIRCULATION MODEL OUTPUT IN THE CREATION OF CLIMATE CHANGE SCENARIOS
Robock, Alan
, Sub-Saharan Africa and Venezuela, for use in biological effects models. By combining the general, and possible solar variations, and all agree that surface air temperatures will rise, pre- cipitation patterns will change, and sea level will rise. Even though such projections of the future are relatively crude
Robert G. Ellingson
2004-09-28T23:59:59.000Z
One specific goal of the Atmospheric Radiation Measurements (ARM) program is to improve the treatment of radiative transfer in General Circulation Models (GCMs) under clear-sky, general overcast and broken cloud conditions. Our project was geared to contribute to this goal by attacking major problems associated with one of the dominant radiation components of the problem --longwave radiation. The primary long-term project objectives were to: (1) develop an optimum longwave radiation model for use in GCMs that has been calibrated with state-of-the-art observations for clear and cloudy conditions, and (2) determine how the longwave radiative forcing with an improved algorithm contributes relatively in a GCM when compared to shortwave radiative forcing, sensible heating, thermal advection and convection. The approach has been to build upon existing models in an iterative, predictive fashion. We focused on comparing calculations from a set of models with operationally observed data for clear, overcast and broken cloud conditions. The differences found through the comparisons and physical insights have been used to develop new models, most of which have been tested with new data. Our initial GCM studies used existing GCMs to study the climate model-radiation sensitivity problem. Although this portion of our initial plans was curtailed midway through the project, we anticipate that the eventual outcome of this approach will provide both a better longwave radiative forcing algorithm and from our better understanding of how longwave radiative forcing influences the model equilibrium climate, how improvements in climate prediction using this algorithm can be achieved.
Sokolov, Andrei P.
Conducting probabilistic climate projections with a particular climate model requires the ability to vary the model’s characteristics, such as its climate sensitivity. In this study, the authors implement and validate a ...
Arumugam, Sankar
Improving Groundwater Predictions Utilizing Seasonal Precipitation Forecasts from General. The research reported in this paper evaluates the potential in developing 6-month-ahead groundwater Surface Temperature forecasts. Ten groundwater wells and nine streamgauges from the USGS Groundwater
Petascale Atmospheric General Circulation Models R. D. Nair and H. M. Tufo#
Nair, Ramachandran D.
) into an Earth system model will require a highly scalable and accurate flux-form formulation of the dynamics
Cloud/Aerosol Parameterizations: Application and Improvement of General Circulation Models
Penner, Joyce
2012-06-30T23:59:59.000Z
One of the biggest uncertainties associated with climate models and climate forcing is the treatment of aerosols and their effects on clouds. The effect of aerosols on clouds can be divided into two components: The first indirect effect is the forcing associated with increases in droplet concentrations; the second indirect effect is the forcing associated with changes in liquid water path, cloud morphology, and cloud lifetime. Both are highly uncertain. This project applied a cloud-resolving model to understand the response of clouds under a variety of conditions to changes in aerosols. These responses are categorized according to the large-scale meteorological conditions that lead to the response. Meteorological conditions were sampled from various fields, which, together with a global aerosol model determination of the change in aerosols from present day to pre-industrial conditions, was used to determine a first order estimate of the response of global cloud fields to changes in aerosols. The response of the clouds in the NCAR CAM3 GCM coupled to our global aerosol model were tested by examining whether the response is similar to that of the cloud resolving model and methods for improving the representation of clouds and cloud/aerosol interactions were examined.
NOAA Technical Memorandum ERL GLERL-16 A GENERAL CIRCULATION MODEL FOR LAKES
Stability 4.5 Energy Conservation PRELIMINARY RESULTS SUMMARY AND CONCLUSIONS . ACKNOWLEDGMENTS REFERENCES of prognostic variables. Vertically integrated transport function under the south- westerly wind. Time evolution of the kinetic energy in the Lake Ontario model; (a) Total kinetic energy, (b) Kinetic energy of the barorropic
Ellingson, R.G.; Baer, F.
1998-09-01T23:59:59.000Z
DOE has launched a major initiative -- the Atmospheric Radiation Measurements (ARM) Program -- directed at improving the parameterization of the physics governing cloud and radiative processes in general circulation models (GCMs). One specific goal of ARM is to improve the treatment of radiative transfer in GCMs under clear-sky, general overcast and broken cloud conditions. In 1990, the authors proposed to contribute to this goal by attacking major problems connected with one of the dominant radiation components of the problem -- longwave radiation. In particular, their long-term research goals are to: develop an optimum longwave radiation model for use in GCMs that has been calibrated with state-of-the-art observations, assess the impact of the longwave radiative forcing in a GCM, determine the sensitivity of a GCM to the radiative model used in it, and determine how the longwave radiative forcing contributes relatively when compared to shortwave radiative forcing, sensible heating, thermal advection and expansion.
Roble, R.G.; Ridley, E.C.
1994-03-15T23:59:59.000Z
A new simulation model of the mesosphere, thermosphere, and ionosphere with coupled electrodynamics has been developed and used to calculate the global circulation, temperature and compositional structure between 30-500 km for equinox, solar cycle minimum, geomagnetic quiet conditions. The model incorporates all of the features of the NCAR thermosphere-ionosphere-electrodynamics general circulation model (TIE-GCM) but the lower boundary has been extended downward from 97 to 30 km (10 mb) and it includes the physical and chemical processes appropriate for the mesosphere and upper stratosphere. The first simulation used Rayleigh friction to represent gravity wave drag in the middle atmosphere and although it was able to close the mesospheric jets it severely damped the diurnal tide. Reduced Rayleigh friction allowed the tide to penetrate to thermospheric heights but did not close the jets. A gravity wave parameterization developed by Fritts and Lu allows both features to exist simultaneously with the structure of tides and mean flow dependent upon the strength of the gravity wave source. The model calculates a changing dynamic structure with the mean flow and diurnal tide dominant in the mesosphere, the in-situ generated semi-diurnal tide dominating the lower thermosphere and an in-situ generated diurnal tide in the upper thermosphere. The results also show considerable interaction between dynamics and composition, especially atomic oxygen between 85 and 120 km. 31 refs., 3 figs.
Ellingson, R.G.; Baer, F.
1993-12-31T23:59:59.000Z
This report summarizes the activities of our group to meet our stated objectives. The report is divided into sections entitled: Radiation Model Testing Activities, General Circulation Model Testing Activities, Science Team Activities, and Publications, Presentations and Meetings. The section on Science Team Activities summarizes our participation with the science team to further advance the observation and modeling programs. Appendix A lists graduate students supported, and post-doctoral appointments during the project. Reports on the activities during each of the first two years are included as Appendix B. Significant progress has been made in: determining the ability of line-by-line radiation models to calculate the downward longwave flux at the surface; determining the uncertainties in calculated the downwelling radiance and flux at the surface associated with the use of different proposed profiling techniques; intercomparing clear-sky radiance and flux observations with calculations from radiation codes from different climate models; determining the uncertainties associated with estimating N* from surface longwave flux observations; and determining the sensitivity of model calculations to different formulations of the effects of finite sized clouds.
On the Wind Power Input to the Ocean General Circulation
Zhai, Xiaoming
The wind power input to the ocean general circulation is usually calculated from the time-averaged wind products. Here, this wind power input is reexamined using available observations, focusing on the role of the synoptically ...
Tao, Wei-Kuo; Houze, Robert, A., Jr.; Zeng, Xiping
2013-03-14T23:59:59.000Z
This three-year project, in cooperation with Professor Bob Houze at University of Washington, has been successfully finished as planned. Both ARM (the Atmospheric Radiation Measurement Program) data and cloud-resolving model (CRM) simulations were used to identify the water budgets of clouds observed in two international field campaigns. The research results achieved shed light on several key processes of clouds in climate change (or general circulation models), which are summarized below. 1. Revealed the effect of mineral dust on mesoscale convective systems (MCSs) Two international field campaigns near a desert and a tropical coast provided unique data to drive and evaluate CRM simulations, which are TWP-ICE (the Tropical Warm Pool International Cloud Experiment) and AMMA (the African Monsoon Multidisciplinary Analysis). Studies of the two campaign data were contrasted, revealing that much mineral dust can bring about large MCSs via ice nucleation and clouds. This result was reported as a PI presentation in the 3rd ASR Science Team meeting held in Arlington, Virginia in March 2012. A paper on the studies was published in the Journal of the Atmospheric Sciences (Zeng et al. 2013). 2. Identified the effect of convective downdrafts on ice crystal concentration Using the large-scale forcing data from TWP-ICE, ARM-SGP (the Southern Great Plains) and other field campaigns, Goddard CRM simulations were carried out in comparison with radar and satellite observations. The comparison between model and observations revealed that convective downdrafts could increase ice crystal concentration by up to three or four orders, which is a key to quantitatively represent the indirect effects of ice nuclei, a kind of aerosol, on clouds and radiation in the Tropics. This result was published in the Journal of the Atmospheric Sciences (Zeng et al. 2011) and summarized in the DOE/ASR Research Highlights Summaries (see http://www.arm.gov/science/highlights/RMjY5/view). 3. Used radar observations to evaluate model simulations In cooperation with Profs. Bob Houze at University of Washington and Steven Rutledge at Colorado State University, numerical model results were evaluated with observations from W- and C-band radars and CloudSat/TRMM satellites. These studies exhibited some shortcomings of current numerical models, such as too little of thin anvil clouds, directing the future improvement of cloud microphysics parameterization in CRMs. Two papers of Powell et al (2012) and Zeng et al. (2013), summarizing these studies, were published in the Journal of the Atmospheric Sciences. 4. Analyzed the water budgets of MCSs Using ARM data from TWP-ICE, ARM-SGP and other field campaigns, the Goddard CRM simulations were carried out to analyze the water budgets of clouds from TWP-ICE and AMMA. The simulations generated a set of datasets on clouds and radiation, which are available http://cloud.gsfc.nasa.gov/. The cloud datasets were available for modelers and other researchers aiming to improve the representation of cloud processes in multi-scale modeling frameworks, GCMs and climate models. Special datasets, such as 3D cloud distributions every six minutes for TWP-ICE, were requested and generated for ARM/ASR investigators. Data server records show that 86,206 datasets were downloaded by 120 users between April of 2010 and January of 2012. 5. MMF simulations The Goddard MMF (multi-scale modeling framework) has been improved by coupling with the Goddard Land Information System (LIS) and the Goddard Earth Observing System Model, Version 5 (GOES5). It has also been optimized on NASA HEC supercomputers and can be run over 4000 CPUs. The improved MMF with high horizontal resolution (1 x 1 degree) is currently being applied to cases covering 2005 and 2006. The results show that the spatial distribution pattern of precipitation rate is well simulated by the MMF through comparisons with satellite retrievals from the CMOPRH and GPCP data sets. In addition, the MMF results were compared with three reanalyses (MERRA, ERA-Interim and CFSR). Although the MMF tends
Predictive models of circulating fluidized bed combustors
Gidaspow, D.
1992-07-01T23:59:59.000Z
Steady flows influenced by walls cannot be described by inviscid models. Flows in circulating fluidized beds have significant wall effects. Particles in the form of clusters or layers can be seen to run down the walls. Hence modeling of circulating fluidized beds (CFB) without a viscosity is not possible. However, in interpreting Equations (8-1) and (8-2) it must be kept in mind that CFB or most other two phase flows are never in a true steady state. Then the viscosity in Equations (8-1) and (8-2) may not be the true fluid viscosity to be discussed next, but an Eddy type viscosity caused by two phase flow oscillations usually referred to as turbulence. In view of the transient nature of two-phase flow, the drag and the boundary layer thickness may not be proportional to the square root of the intrinsic viscosity but depend upon it to a much smaller extent. As another example, liquid-solid flow and settling of colloidal particles in a lamella electrosettler the settling process is only moderately affected by viscosity. Inviscid flow with settling is a good first approximation to this electric field driven process. The physical meaning of the particulate phase viscosity is described in detail in the chapter on kinetic theory. Here the conventional derivation resented in single phase fluid mechanics is generalized to multiphase flow.
Collett Jr., Jeffrey L.
NASA's new modeling framework for integrating cloud processes explicitly within each grid column, AND SIMPSON--Laboratory for Atmospheres, NASA Goddard Space Flight Center, Greenbelt, Maryland; CHERN--Laboratory for Atmospheres, NASA Goddard Space Flight Center, Greenbelt, and Goddard Earth Sciences and Technology Center
Houze, Jr., Robert A. [University of Washington Dept. of Atmospheric Sciences
2013-11-13T23:59:59.000Z
We examined cloud radar data in monsoon climates, using cloud radars at Darwin in the Australian monsoon, on a ship in the Bay of Bengal in the South Asian monsoon, and at Niamey in the West African monsoon. We followed on with a more in-depth study of the continental MCSs over West Africa. We investigated whether the West African anvil clouds connected with squall line MCSs passing over the Niamey ARM site could be simulated in a numerical model by comparing the observed anvil clouds to anvil structures generated by the Weather Research and Forecasting (WRF) mesoscale model at high resolution using six different ice-phase microphysical schemes. We carried out further simulations with a cloud-resolving model forced by sounding network budgets over the Niamey region and over the northern Australian region. We have devoted some of the effort of this project to examining how well satellite data can determine the global breadth of the anvil cloud measurements obtained at the ARM ground sites. We next considered whether satellite data could be objectively analyzed to so that their large global measurement sets can be systematically related to the ARM measurements. Further differences were detailed between the land and ocean MCS anvil clouds by examining the interior structure of the anvils with the satellite-detected the CloudSat Cloud Profiling Radar (CPR). The satellite survey of anvil clouds in the Indo-Pacific region was continued to determine the role of MCSs in producing the cloud pattern associated with the MJO.
Rao, Samrat
2015-01-01T23:59:59.000Z
An atmospheric general circulation model (AGCM) with idealized and complete physics has been used to evaluate the Tropical Easterly Jet (TEJ) jet. In idealized physics, the role of upper tropospheric friction has been found to be important in getting realistic upper tropospheric zonal wind patterns in response to heating. In idealized physics, the location and strength of the TEJ as a response to Gill heating has been studied. Though the Gill model is considered to be widely successful in capturing the lower tropospheric response, it is found to be inadequate in explaining the location and strength of the upper level TEJ. Heating from the Gill model and realistic upper tropospheric friction does not lead to the formation of a TEJ.
Continuous VRML output fromContinuous VRML output from regional circulation models: aregional and volume to viewview ·· Generate Virtual Reality Modeling LanguageGenerate Virtual Reality ModelingDesktop or laptop PC with web browser High speed/large RAM not essentialHigh speed/large RAM not essential
On the Wind Power Input to the Ocean General Circulation XIAOMING ZHAI
Wunsch, Carl
On the Wind Power Input to the Ocean General Circulation XIAOMING ZHAI Atmospheric, Oceanic January 2012, in final form 3 May 2012) ABSTRACT The wind power input to the ocean general circulation is usually calculated from the time-averaged wind products. Here, this wind power input is reexamined using
Power-Law and Long-Memory Characteristics of the Atmospheric General Circulation DMITRY I. VYUSHIN memory'' or ``power-law'' model. Such a model fits a temporal spectrum to a single power-law function, which thereby accumulates more power at lower frequencies than an AR1 fit. In this study, several power
COMPUTATIONAL MODELING OF CIRCULATING FLUIDIZED BED REACTORS
Ibrahim, Essam A
2013-01-09T23:59:59.000Z
Details of numerical simulations of two-phase gas-solid turbulent flow in the riser section of Circulating Fluidized Bed Reactor (CFBR) using Computational Fluid Dynamics (CFD) technique are reported. Two CFBR riser configurations are considered and modeled. Each of these two riser models consist of inlet, exit, connecting elbows and a main pipe. Both riser configurations are cylindrical and have the same diameter but differ in their inlet lengths and main pipe height to enable investigation of riser geometrical scaling effects. In addition, two types of solid particles are exploited in the solid phase of the two-phase gas-solid riser flow simulations to study the influence of solid loading ratio on flow patterns. The gaseous phase in the two-phase flow is represented by standard atmospheric air. The CFD-based FLUENT software is employed to obtain steady state and transient solutions for flow modulations in the riser. The physical dimensions, types and numbers of computation meshes, and solution methodology utilized in the present work are stated. Flow parameters, such as static and dynamic pressure, species velocity, and volume fractions are monitored and analyzed. The differences in the computational results between the two models, under steady and transient conditions, are compared, contrasted, and discussed.
Testing Components of New Community Isopycnal Ocean Circulation Model
Bryan, Kirk
2008-05-09T23:59:59.000Z
The ocean and atmosphere are both governed by the same physical laws and models of the two media have many similarities. However, there are critical differences that call for special methods to provide the best simulation. One of the most important difference is that the ocean is nearly opaque to radiation in the visible and infra-red part of the spectrum. For this reason water mass properties in the ocean are conserved along trajectories for long distances and for long periods of time. For this reason isopycnal coordinate models would seem to have a distinct advantage in simulating ocean circulation. In such a model the coordinate surfaces are aligned with the natural paths of near adiabatic, density conserving flow in the main thermocline. The difficulty with this approach is at the upper and lower boundaries of the ocean, which in general do not coincide with density surfaces. For this reason hybrid coordinate models were proposed by Bleck and Boudra (1981) in which Cartesian coordinates were used near the ocean surface and isopycnal coordinates were used in the main thermocline. This feature is now part of the HICOM model (Bleck, 2002).
1950 B i M d l 1960 General Circulation
Rannacher, Rolf
AFA 2001 TAR 2000 Earth System Models (ESMs) 2014 ARS Climate Research Meteo- rology Climate Change Atmosphere Ocean Models (AOGCMs) 1979 Charney Report 1990 FAR 1995 SAR 2007 AFA 2001 TAR 2000 Earth System Models (ESMs) 2014 ARS Climate Research Meteo- rology Climate Change Science and Policy 1 Cl Re Meteo
Optimal control of CPR procedure using hemodynamic circulation model
Lenhart, Suzanne M. (Knoxville, TN); Protopopescu, Vladimir A. (Knoxville, TN); Jung, Eunok (Seoul, KR)
2007-12-25T23:59:59.000Z
A method for determining a chest pressure profile for cardiopulmonary resuscitation (CPR) includes the steps of representing a hemodynamic circulation model based on a plurality of difference equations for a patient, applying an optimal control (OC) algorithm to the circulation model, and determining a chest pressure profile. The chest pressure profile defines a timing pattern of externally applied pressure to a chest of the patient to maximize blood flow through the patient. A CPR device includes a chest compressor, a controller communicably connected to the chest compressor, and a computer communicably connected to the controller. The computer determines the chest pressure profile by applying an OC algorithm to a hemodynamic circulation model based on the plurality of difference equations.
The Mars thermosphere. 2. General circulation with coupled dynamics and composition
Bougher, S.W. (Univ. of Arizona, Tucson (USA)); Roble, R.G.; Ridley, E.C.; Dickinson, R.E. (National Center for Atmospheric Research, Boulder, CO (USA))
1990-08-30T23:59:59.000Z
The National Center for Atmospheric Research thermospheric general circulation model (TGCM) for the Earth's thermosphere has been modified to examine the three-dimensional structure and circulation of the upper mesosphere and thermosphere of Mars (MTGCM). The computational framework and major processes unique to a CO{sub 2} thermosphere are similar to those utilized in a recent Venus TGCM. Solar EUV, UV, and IR heating alone combine to drive the Martian winds above {approximately}100 km. An equinox version of the code is used to examine the Mars global dynamics and structure for two specific observational periods spanning a range of solar activity: Viking 1 (July 1976) and Mariner 6-7 (August-September 1969). The MTGCM is then modified to predict the state of the Mars thermosphere for various combinations of solar and orbital conditions. Calculations show that no nightside cryosphere of the type observed on Venus is obtained on the Mars nightside. Instead, planetary rotation significantly modifies the winds and the day-to-night contrast in densities and temperatures, giving a diurnal behavior similar to the Earth under quiet solar conditions. Maximum exospheric temperatures are calculated near 1,500 LT ({le} 305 K), with minimum values at 0500 LT ({le} 175 K). The global temperature distribution is strongly modified by nightside adiabatic heating (subsidence) and dayside cooling (upwelling). The global winds also affect vertical density distributions; vertical eddy diffusion much weaker than used in previous one-dimensional models is required to maintain observed Viking profiles. A solar cycle variation in dayside exospheric temperatures of {approximately}195-305 K is simulated by the Viking and Mariner runs.
Arctic sea ice velocity field: General circulation and turbulent-like fluctuations
Boyer, Edmond
that are activated intermittently within the ice pack. Citation: Rampal, P., J. Weiss, D. Marsan, and M. BourgoinArctic sea ice velocity field: General circulation and turbulent-like fluctuations P. Rampal,1,2 J the Arctic sea ice velocity field as the superposition of a mean field and fluctuations. We study how
Allan, Richard P.
Environment Model (HiGEM), suggest that including mineral dust radiative effects removes this bias21 June 2007, although differences in cloud cover also impact the modelGERB differences. Copyright c 2011 A Examination of long-wave radiative bias in general circulation models over North Africa during
MODELING CYCLIC WAVES OF CIRCULATING T CELLS IN AUTOIMMUNE DIABETES
Mahaffy, Joseph M.
MODELING CYCLIC WAVES OF CIRCULATING T CELLS IN AUTOIMMUNE DIABETES JOSEPH M. MAHAFFY AND LEAH EDELSTEIN-KESHET Abstract. Type 1 diabetes (T1D) is an autoimmune disease in which immune cells, notably T diabetes result once a large enough fraction of these beta cells have been destroyed. Recent investigation
MacCready, Parker
Seasonal and Interannual Variability in the Circulation of Puget Sound, Washington: A Box Model A prognostic, time-dependent box model of circulation in Puget Sound, Washington is used to study seasonal circulation dans le détroit de Puget, dans l'État de Washington, pour étudier les variations saisonnières et
Modeling of a coal-fired natural circulation boiler
Bhambare, K.S.; Mitra, S.K.; Gaitonde, U.N. [Indian Institute of Technology, Bombay (India). Dept. of Mechanical Engineering
2007-06-15T23:59:59.000Z
Modeling of a natural circulation boiler for a coal-fired thermal power station is presented here. The boiler system is divided into seven subcomponents, and for each section, models based on conservation of mass, momentum, and energy are formulated. The pressure drop at various sections and the heat transfer coefficients are computed using empirical correlations. Solutions are obtained by using SIMULINK. The model is validated by comparing its steady state and dynamic responses with the actual plant data. Open loop responses of the model to the step changes in the operating parameters, such as pressure, temperature, steam flow, feed water flow, are also analyzed. The present model can be used for the development and design of effective boiler control systems.
RHP: HOW CLIMATE MODELS GAIN AND EXERCISE How Climate Models Gain and Exercise Authority
Hulme, Mike
-dimensional models, intermediate complexity models, general circulation models, and Earth system models. 2 www
Modeling the 19982003 summer circulation and thermal structure in Lake Michigan
Modeling the 19982003 summer circulation and thermal structure in Lake Michigan Dmitry Beletsky,1 to Lake Michigan on a 2 km grid for 6 consecutive years to study interannual variability of summer. Circulation in southern Lake Michigan appears to be more variable than circulation in northern Lake Michigan
Chung, Y.G.; Lee, G.B.; Bang, S.Y. [Korea Electric Power Research Institute, 103-16 Munji-Dong, Yuseong-Gu, Daejeon 305-380 (Korea, Republic of); Choi, S.B.; Lee, S.U. [Korea Hydro and Nuclear Power Co., LTD, 167 Samseong-Dong, Gangnam-Gu, Seoul 135-791 (Korea, Republic of); Yoon, J.H. [Research Institute of Applied Physics, Kyushu University, 6-1 Kasuga-kouen, Kasuga, Fukuoka, 816-8580 (Japan); Nam, S.Y.; Lee, H.R. [GeoSystem Research Corporation, 306 Hanlim Human Town, 1-40 Geumjeong-Dong, Gunpo-City, Gyeonggi-Do 435-050 (Korea, Republic of)
2006-07-01T23:59:59.000Z
Recently, three-dimensional models have been used for aquatic dispersion of radioactive effluents in relation to nuclear power plant siting based on the Notice No. 2003-12 'Guideline for investigating and assessing hydrological and aquatic characteristics of nuclear facility site' of the Ministry of Science and Technology (MOST) in Korea. Several nuclear power plants have been under construction or planed, which are Shin-Kori Unit 1 and 2, Shin-Wolsong Unit 1 and 2, and Shin-Ulchin Unit 1 and 2. For assessing the aquatic dispersion of radionuclides released from the above nuclear power plants, it is necessary to know the coastal currents around sites which are affected by circulation of East Sea. In this study, a three dimensional hydrodynamic model for the circulation of the East Sea of Korea has been developed as the first phase, which is based on the RIAMOM (Research Institute of Applied Mechanics' Ocean Model, Kyushu University, Japan). The model uses the primitive equation with hydrostatic approximation, and uses Arakawa-B grid system horizontally and Z coordinate vertically. Model domain is 126.5 deg. E to 142.5 deg. E of east longitude and 33 deg. N and 52 deg. N of the north latitude. The space of the horizontal grid was 1/12 deg. to longitude and latitude direction and vertical level was divided to 20. This model uses Generalized Arakawa Scheme, Slant Advection, and Mode-Splitting Method. The input data were from JODC (Japan Oceanographic Data Center), KNFRDI (Korea National Fisheries Research and Development Institute), and ECMWF (European Center for Medium-Range Weather Forecasts). The modeling results are in fairly good agreement with schematic patterns of the surface circulation in the East Sea/Japan Sea. The local current model and aquatic dispersion model of the coastal region will be developed as the second phase. The oceanic dispersion experiments will be also carried out by using ARGO Drifter around a nuclear power plant site. (authors)
Lyapunov Exponents of a Simple Stochastic Model of the Thermally and Wind-Driven Ocean Circulation
Monahan, Adam Hugh
Lyapunov Exponents of a Simple Stochastic Model of the Thermally and Wind-Driven Ocean Circulation, then the leading Lyapunov exponent of the circulation can become positive for sufficiently strong fluctuations of the leading Lyapunov exponent can have a substantial effect on the predictability of the system. 1 #12
3D modeling of GJ1214b's atmosphere: vertical mixing driven by an anti-Hadley circulation
Charnay, Benjamin; Leconte, Jérémy
2015-01-01T23:59:59.000Z
GJ1214b is a warm sub-Neptune transiting in front of a nearby M dwarf star. Recent observations indicate the presence of high and thick clouds or haze whose presence requires strong atmospheric mixing. In order to understand the transport and distribution of such clouds/haze, we study the atmospheric circulation and the vertical mixing of GJ1214b with a 3D General Circulation Model for cloud-free hydrogen-dominated atmospheres (metallicity of 1, 10 and 100 times the solar value) and for a water-dominated atmosphere. We analyze the effect of the atmospheric metallicity on the thermal structure and zonal winds. We also analyze the zonal mean meridional circulation and show that it corresponds to an anti-Hadley circulation in most of the atmosphere with upwelling at mid-latitude and downwelling at the equator in average. This circulation must be present on a large range of synchronously rotating exoplanets with strong impact on cloud formation and distribution. Using simple tracers, we show that vertical winds o...
Predictive models of circulating fluidized bed combustors. 12th technical progress report
Gidaspow, D.
1992-07-01T23:59:59.000Z
Steady flows influenced by walls cannot be described by inviscid models. Flows in circulating fluidized beds have significant wall effects. Particles in the form of clusters or layers can be seen to run down the walls. Hence modeling of circulating fluidized beds (CFB) without a viscosity is not possible. However, in interpreting Equations (8-1) and (8-2) it must be kept in mind that CFB or most other two phase flows are never in a true steady state. Then the viscosity in Equations (8-1) and (8-2) may not be the true fluid viscosity to be discussed next, but an Eddy type viscosity caused by two phase flow oscillations usually referred to as turbulence. In view of the transient nature of two-phase flow, the drag and the boundary layer thickness may not be proportional to the square root of the intrinsic viscosity but depend upon it to a much smaller extent. As another example, liquid-solid flow and settling of colloidal particles in a lamella electrosettler the settling process is only moderately affected by viscosity. Inviscid flow with settling is a good first approximation to this electric field driven process. The physical meaning of the particulate phase viscosity is described in detail in the chapter on kinetic theory. Here the conventional derivation resented in single phase fluid mechanics is generalized to multiphase flow.
Posters A Stratiform Cloud Parameterization for General Circulation Models
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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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (Million Cubic Feet)sets safety record |PersonalPhotos7CommitteesProgram -decadal91 Posters A
Posters Comparison Between General Circulation Model Simulation and Central Equatorial
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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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (Million Cubic Feet)sets safety record |PersonalPhotos7CommitteesProgram -decadal91 Posters
Posters Treatment of Cloud Radiative Effects in General Circulation Models
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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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (Million Cubic Feet)sets safety record |PersonalPhotos7CommitteesProgram -decadal917 Posters3313735
Evaluation of cirrus statistics produced by general circulation models
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41clothThe Bonneville Power AdministrationHawaiiEnergy StorageDepartment of EnergyNorth Slope Oils (Technical Report)
Spiga, Aymeric
A new model to simulate the Martian mesoscale and microscale atmospheric circulation: Validation) Mesoscale Model is a new versatile simulator of the Martian atmosphere and environment at horizontal scales, and photochemistry cycles. Since LMD-GCM large-scale simulations are also used to drive the mesoscale model
Modeling wind-driven circulation during the March 1998 sediment resuspension event in Lake Michigan
Modeling wind-driven circulation during the March 1998 sediment resuspension event in Lake Michigan Lake Michigan caused by a storm with winds up to 20 m/s. The hydrodynamic model is driven with surface winds derived from observed meteorological conditions at 18 land stations and a meteorological buoy
Model-free adaptive control of supercritical circulating fluidized-bed boilers
Cheng, George Shu-Xing; Mulkey, Steven L
2014-12-16T23:59:59.000Z
A novel 3-Input-3-Output (3.times.3) Fuel-Air Ratio Model-Free Adaptive (MFA) controller is introduced, which can effectively control key process variables including Bed Temperature, Excess O2, and Furnace Negative Pressure of combustion processes of advanced boilers. A novel 7-input-7-output (7.times.7) MFA control system is also described for controlling a combined 3-Input-3-Output (3.times.3) process of Boiler-Turbine-Generator (BTG) units and a 5.times.5 CFB combustion process of advanced boilers. Those boilers include Circulating Fluidized-Bed (CFB) Boilers and Once-Through Supercritical Circulating Fluidized-Bed (OTSC CFB) Boilers.
the fall cooling, and finally, an overturn in the late fall. Large-scale circulation patterns tend significant progress in hydrodynamic modeling of short- term hydrodynamic processes in the Great Lakes [Schwab was virtually non- existent until the implementation of the Great Lakes Forecast- ing System (GLFS) in the early
A Continuous ` \\Gamma oe Vertical Coordinate for a Baroclinic Model of the Atmospheric Circulation
Drake, John B.
meteorolgoical coordinate system is developed which can support a continuous isentropic oe vertical coordinate and boundary layer approximations were addressed by the introduction of a hybrid (patched) model [15]. By use analysis [14, 8]. The effects of heating on the circulation are most clearly seen with the isentropic
Parameterization of gravity current entrainment for ocean circulation models using a high-order 3D
Ozgökmen, Tamay M.
Parameterization of gravity current entrainment for ocean circulation models using a high-order 3D on the work by Turner [Turner, J.S., 1986. The development of the entrainment assumption and its application. Weather Rev. 128, 14021419], an algebraic parameterization of the entrainment process in gravity current
DETECTING AND TRACKING OF MESOSCALE OCEANIC FEATURES IN THE MIAMI ISOPYCNIC CIRCULATION OCEAN MODEL
Tandon, Amit
DETECTING AND TRACKING OF MESOSCALE OCEANIC FEATURES IN THE MIAMI ISOPYCNIC CIRCULATION OCEAN MODEL developed to automatically detect, locate and track mesoscale eddies spatially and temporally. Using an invaluable tool to assess mesoscale oceanic features. Key Words Scientific Visualization, Eddy Detection
Follows, Mick
Evaluating carbon sequestration efficiency in an ocean circulation model by adjoint sensitivity the application of the adjoint method to develop three-dimensional maps of carbon sequestration efficiency. Sequestration efficiency (the percentage of carbon injected at a continuous point source that remains
The effects of North Atlantic SST and sea-ice anomalies on the winter circulation in CCM3.
Magnusdottir, Gudrun
1 The effects of North Atlantic SST and sea-ice anomalies on the winter circulation in CCM3. Part of experiments with an atmospheric general circulation model, Community Climate Model Version 3 (CCM3). As shown
Modeling Timed Concurrent Systems using Generalized Ultrametrics
Modeling Timed Concurrent Systems using Generalized Ultrametrics Xiaojun Liu Eleftherios Matsikoudis Edward A. Lee Electrical Engineering and Computer Sciences University of California at Berkeley to lists, requires prior specific permission. #12;Modeling Timed Concurrent Systems using Generalized
Computable General Equilibrium Models for Sustainability Impact...
and prospects Screenshot References: Computable general equilibrium models1 Abstract "Sustainability Impact Assessment (SIA) of economic, environmental, and social effects...
40 greater influence and penetration of deep water formed in 41 the Southern Ocean [e.g., Oppo2 Ocean circulation at the Last Glacial Maximum: 3 A combined modeling and magnetic proxy (NADW) is an important component of the ocean thermohaline 7 circulation, but debate exists over
Paris-Sud XI, Université de
Central South Pacific thermocline water circulation from a high-resolution ocean model validated. Introduction [2] Most South Pacific Ocean studies have been focused on its western or eastern part, leaving 12 January 2009; accepted 28 January 2009; published 13 May 2009. [1] The oceanic circulation
MODELING STRATEGIES TO COMPUTE NATURAL CIRCULATION USING CFD IN A VHTR AFTER A LOFA
Yu-Hsin Tung; Richard W. Johnson; Ching-Chang Chieng; Yuh-Ming Ferng
2012-11-01T23:59:59.000Z
A prismatic gas-cooled very high temperature reactor (VHTR) is being developed under the next generation nuclear plant program (NGNP) of the U.S. Department of Energy, Office of Nuclear Energy. In the design of the prismatic VHTR, hexagonal shaped graphite blocks are drilled to allow insertion of fuel pins, made of compacted TRISO fuel particles, and coolant channels for the helium coolant. One of the concerns for the reactor design is the effects of a loss of flow accident (LOFA) where the coolant circulators are lost for some reason, causing a loss of forced coolant flow through the core. In such an event, it is desired to know what happens to the (reduced) heat still being generated in the core and if it represents a problem for the fuel compacts, the graphite core or the reactor vessel (RV) walls. One of the mechanisms for the transport of heat out of the core is by the natural circulation of the coolant, which is still present. That is, how much heat may be transported by natural circulation through the core and upwards to the top of the upper plenum? It is beyond current capability for a computational fluid dynamic (CFD) analysis to perform a calculation on the whole RV with a sufficiently refined mesh to examine the full potential of natural circulation in the vessel. The present paper reports the investigation of several strategies to model the flow and heat transfer in the RV. It is found that it is necessary to employ representative geometries of the core to estimate the heat transfer. However, by taking advantage of global and local symmetries, a detailed estimate of the strength of the resulting natural circulation and the level of heat transfer to the top of the upper plenum is obtained.
Study of natural circulation in a VHTR after a LOFA using different turbulence models
Yu-Hsin Tung; Yuh-Ming Ferng; Richard W. Johnson; Ching-Chang Chieng
2013-10-01T23:59:59.000Z
Natural convection currents in the core are anticipated in the event of the failure of the gas circulator in a prismatic gas-cooled very high temperature reactor (VHTR). The paths that the helium coolant takes in forming natural circulation loops and the effective heat transport are of interest. The heated flow in the reactor core is turbulent during normal operating conditions and at the beginning of the LOFA with forced convection, but the flow may significantly be slowed down after the event and laminarized with mixed convection. In the present study, the potential occurrence and effective heat transport of natural circulation are demonstrated using computational fluid dynamic (CFD) calculations with different turbulence models as well as laminar flow. Validations and recommendation on turbulence model selection are conducted. The study concludes that large loop natural convection is formed due to the enhanced turbulence levels by the buoyancy effect and the turbulent regime near the interface of upper plenum and flow channels increases the flow resistance for channel flows entering upper plenum and thus less heat can be removed from the core than the prediction by laminar flow assumption.
Cheon, Woo Geunn
2009-05-15T23:59:59.000Z
This dissertation discusses a linkage between the Southern Ocean (SO) winds and the global ocean circulation in the framework of a coarse-resolution global ocean general circulation model coupled to a sea-ice model. In addition to reexamination...
GENERAL CIRCULATION Energy Cycle
Grotjahn, Richard
process. PE is useful for global energy balance. Solar radiant energy does not reach the Earth equally everywhere. On average, the tropics receive and absorb far more solar energy annually than the polar regions is converted to motions that redistribute the heat energy; KE in turn is lost by conversion back to APE
Ma, Po-Lun; Rasch, Philip J.; Wang, Hailong; Zhang, Kai; Easter, Richard C.; Tilmes, S.; Fast, Jerome D.; Liu, Xiaohong; Yoon, Jin-Ho; Lamarque, Jean-Francois
2013-05-28T23:59:59.000Z
Current climate models generally under-predict the surface concentration of black carbon (BC) in the Arctic due to the uncertainties associated with emissions, transport, and removal. This bias is also present in the Community Atmosphere Model Version 5.1 (CAM5). In this study, we investigate the uncertainty of Arctic BC due to transport processes simulated by CAM5 by configuring the model to run in an “offline mode” in which the large-scale circulations are prescribed. We compare the simulated BC transport when the offline model is driven by the meteorology predicted by the standard free-running CAM5 with simulations where the meteorology is constrained to agree with reanalysis products. Some circulation biases are apparent: the free-running CAM5 produces about 50% less transient eddy transport of BC than the reanalysis-driven simulations, which may be attributed to the coarse model resolution insufficient to represent eddies. Our analysis shows that the free-running CAM5 reasonably captures the essence of the Arctic Oscillation (AO), but some discernable differences in the spatial pattern of the AO between the free-running CAM5 and the reanalysis-driven simulations result in significantly different AO modulation of BC transport over Northeast Asia and Eastern Europe. Nevertheless, we find that the overall climatological circulation patterns simulated by the free-running CAM5 generally resembles those from the reanalysis products, and BC transport is very similar in both simulation sets. Therefore, the simulated circulation features regulating the long-range BC transport is unlikely the most important cause of the large under-prediction of surface BC concentration in the Arctic.
Khangaonkar, Tarang; Yang, Zhaoqing; Kim, Tae Yun; Roberts, Mindy
2011-07-20T23:59:59.000Z
Through extensive field data collection and analysis efforts conducted since the 1950s, researchers have established an understanding of the characteristic features of circulation in Puget Sound. The pattern ranges from the classic fjordal behavior in some basins, with shallow brackish outflow and compensating inflow immediately below, to the typical two-layer flow observed in many partially mixed estuaries with saline inflow at depth. An attempt at reproducing this behavior by fitting an analytical formulation to past data is presented, followed by the application of a three-dimensional circulation and transport numerical model. The analytical treatment helped identify key physical processes and parameters, but quickly reconfirmed that response is complex and would require site-specific parameterization to include effects of sills and interconnected basins. The numerical model of Puget Sound, developed using unstructured-grid finite volume method, allowed resolution of the sub-basin geometric features, including presence of major islands, and site-specific strong advective vertical mixing created by bathymetry and multiple sills. The model was calibrated using available recent short-term oceanographic time series data sets from different parts of the Puget Sound basin. The results are compared against (1) recent velocity and salinity data collected in Puget Sound from 2006 and (2) a composite data set from previously analyzed historical records, mostly from the 1970s. The results highlight the ability of the model to reproduce velocity and salinity profile characteristics, their variations among Puget Sound subbasins, and tidally averaged circulation. Sensitivity of residual circulation to variations in freshwater inflow and resulting salinity gradient in fjordal sub-basins of Puget Sound is examined.
Simple implementation of general dark energy models
Bloomfield, Jolyon K. [MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Ave #37241, Cambridge, MA, 02139 (United States); Pearson, Jonathan A., E-mail: jolyon@mit.edu, E-mail: jonathan.pearson@durham.ac.uk [Centre for Particle Theory, Department of Mathematical Sciences, Durham University, South Road, Durham, DH1 3LE (United Kingdom)
2014-03-01T23:59:59.000Z
We present a formalism for the numerical implementation of general theories of dark energy, combining the computational simplicity of the equation of state for perturbations approach with the generality of the effective field theory approach. An effective fluid description is employed, based on a general action describing single-scalar field models. The formalism is developed from first principles, and constructed keeping the goal of a simple implementation into CAMB in mind. Benefits of this approach include its straightforward implementation, the generality of the underlying theory, the fact that the evolved variables are physical quantities, and that model-independent phenomenological descriptions may be straightforwardly investigated. We hope this formulation will provide a powerful tool for the comparison of theoretical models of dark energy with observational data.
Superconformal generalizations of the Starobinsky model
Kallosh, Renata; Linde, Andrei, E-mail: kallosh@stanford.edu, E-mail: alinde@stanford.edu [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, CA 94305 (United States)
2013-06-01T23:59:59.000Z
We find a way to represent the Starobinsky model in terms of a simple conformally invariant theory with spontaneous symmetry breaking. We also present a superconformal theory, which, upon spontaneous breaking of the superconformal symmetry, provides a consistent supergravity generalization of the Starobinsky model.
Newtonian Aspects of General Relativistic Galaxy Models
Aleksandar Rakic; Dominik J. Schwarz
2008-11-13T23:59:59.000Z
Many cosmological observations call for the existence of dark matter. The most direct evidence for dark matter is inferred from the measured flatness of galactic rotation curves. The latter is based on Newtonian gravity. Alternative approaches to the rotation curve problem by means of general relativity have recently been put forward. The class of models of interest is a subset of the axially symmetric and stationary solutions of Einstein's equations with rotating dust. As a step toward the understanding of general relativistic galaxy models, we analyse rigidly as well as non-rigidly rotating (Post-)Newtonian spacetimes. We find that the Newtonian limit of the considered general relativistic galaxy model leads to Post-Newtonian terms in the metric.
Modelling anisotropic fluid spheres in general relativity
Boonserm, Petarpa; Visser, Matt
2015-01-01T23:59:59.000Z
We argue that an arbitrary general relativistic anisotropic fluid sphere, (spherically symmetric but with transverse pressure not equal to radial pressure), can nevertheless be successfully modelled by suitable linear combinations of quite ordinary classical matter: an isotropic perfect fluid, a classical electromagnetic field, and a classical (minimally coupled) scalar field. While the most general decomposition is not unique, a preferred minimal decomposition can be constructed that is unique. We show how the classical energy conditions for the anisotropic fluid sphere can be related to energy conditions for the isotropic perfect fluid, electromagnetic field, and scalar field components of the model. Furthermore we show how this decomposition relates to the distribution of electric charge density and scalar charge density throughout the model that is used to mimic the anisotropic fluid sphere. Consequently, we can build physically reasonable matter models for almost any spherically symmetric spacetime.
Modelling anisotropic fluid spheres in general relativity
Petarpa Boonserm; Tritos Ngampitipan; Matt Visser
2015-02-03T23:59:59.000Z
We argue that an arbitrary general relativistic anisotropic fluid sphere, (spherically symmetric but with transverse pressure not equal to radial pressure), can nevertheless be successfully modelled by suitable linear combinations of quite ordinary classical matter: an isotropic perfect fluid, a classical electromagnetic field, and a classical (minimally coupled) scalar field. While the most general decomposition is not unique, a preferred minimal decomposition can be constructed that is unique. We show how the classical energy conditions for the anisotropic fluid sphere can be related to energy conditions for the isotropic perfect fluid, electromagnetic field, and scalar field components of the model. Furthermore we show how this decomposition relates to the distribution of electric charge density and scalar charge density throughout the model that is used to mimic the anisotropic fluid sphere. Consequently, we can build physically reasonable matter models for almost any spherically symmetric spacetime.
Dynamical models with a general anisotropy profile
M. Baes; E. Van Hese
2007-05-28T23:59:59.000Z
Both numerical simulations and observational evidence indicate that the outer regions of galaxies and dark matter haloes are typically mildly to significantly radially anisotropic. The inner regions can be significantly non-isotropic, depending on the dynamical formation and evolution processes. In an attempt to break the lack of simple dynamical models that can reproduce this behaviour, we explore a technique to construct dynamical models with an arbitrary density and an arbitrary anisotropy profile. We outline a general construction method and propose a more practical approach based on a parameterized anisotropy profile. This approach consists of fitting the density of the model with a set of dynamical components, each of which have the same anisotropy profile. Using this approach we avoid the delicate fine-tuning difficulties other fitting techniques typically encounter when constructing radially anisotropic models. We present a model anisotropy profile that generalizes the Osipkov-Merritt profile, and that can represent any smooth monotonic anisotropy profile. Based on this model anisotropy profile, we construct a very general seven-parameter set of dynamical components for which the most important dynamical properties can be calculated analytically. We use the results to look for simple one-component dynamical models that generate simple potential-density pairs while still supporting a flexible anisotropy profile. We present families of Plummer and Hernquist models in which the anisotropy at small and large radii can be chosen as free parameters. We also generalize these two families to a three-parameter family that self-consistently generates the set of Veltmann potential-density pairs. (Abridged...)
None
2005-07-01T23:59:59.000Z
This work was carried out to understand the behavior of the solid and gas phases in a CFB riser. Only the riser is modeled as a straight pipe. A model with linear algebraic approximation to solids viscosity of the form, {musubs} = 5.34{epsisubs}, ({espisubs} is the solids volume fraction) with an appropriate boundary condition at the wall obtained by approximate momentum balance solution at the wall to acount for the solids recirculation is tested against experimental results. The work done was to predict the flow patterns in the CFB risers from available experimental data, including data from a 7.5-cm-ID CFB riser at the Illinois Institute of Technology and data from a 20.0-cm-ID CFB riser at the Particulate Solid Research, Inc., facility. This research aims at modeling the removal of hydrogen sulfide from hot coal gas using zinc oxide as the sorbent in a circulating fluidized bed and in the process indentifying the parameters that affect the performance of the sulfidation reactor. Two different gas-solid reaction models, the unreacted shrinking core (USC) and the grain model were applied to take into account chemical reaction resistances. Also two different approaches were used to affect the hydrodynamics of the process streams. The first model takes into account the effect of micro-scale particle clustering by adjusting the gas-particle drag law and the second one assumes a turbulent core with pseudo-steady state boundary condition at the wall. A comparison is made with experimental results.
GENERALIZED LINEAR MODELS WITH REGULARIZATION A DISSERTATION
Hastie, Trevor
GENERALIZED LINEAR MODELS WITH REGULARIZATION A DISSERTATION SUBMITTED TO THE DEPARTMENT Park 2006 All Rights Reserved ii #12;I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor
Abstract polymer models with general pair interactions
Aldo Procacci
2008-11-26T23:59:59.000Z
A convergence criterion of cluster expansion is presented in the case of an abstract polymer system with general pair interactions (i.e. not necessarily hard core or repulsive). As a concrete example, the low temperature disordered phase of the BEG model with infinite range interactions, decaying polynomially as $1/r^{d+\\lambda}$ with $\\lambda>0$, is studied.
Single-Column Modeling A Stratiform Cloud Parameterization for General Circulation Models
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (Million CubicRefinersUpcoming ReleaseSheldon Wolff, 1973 TheHowAminoMechanicalSingleC.J.A
Xie, L.; Pietrafesa, L.J.; Raman, S.
1997-03-18T23:59:59.000Z
Interactions between surface winds and ocean currents over an east-coast continental shelf are studied using a simple mathematical model. The model physics include cross-shelf advection of sea surface temperature (SST) by Ekman drift, upwelling due to Ekman transport divergence, differential heating of the low-level atmosphere by a cross-shelf SST gradient, and the Coriolis effect. Additionally, the effects of diabatic cooling of surface waters due to air-sea heat exchange and of the vertical density stratification on the thickness of the upper ocean Ekman layer are considered. The model results are qualitatively consistent with observed wind-driven coastal ocean circulation and surface wind signatures induced by SST. This simple model also demonstrates that two-way air-sea interaction plays a significant role in the subtidal frequency variability of coastal ocean circulation and mesoscale variability of surface wind fields over coastal waters.
Belucz, Bernadett; Forgacs-Dajka, Emese
2015-01-01T23:59:59.000Z
Babcock-Leighton type solar dynamo models with single-celled meridional circulation are successful in reproducing many solar cycle features. Recent observations and theoretical models of meridional circulation do not indicate a single-celled flow pattern. We examine the role of complex multi-cellular circulation patterns in a Babcock-Leighton solar dynamo in advection- and diffusion-dominated regimes. We show from simulations that presence of a weak, second, high-latitude reverse cell speeds up the cycle and slightly enhances the poleward branch in butterfly diagram, whereas the presence of a second cell in depth reverses the tilt of butterfly wing to an anti-solar type. A butterfly diagram constructed from middle of convection zone yields a solar-like pattern, but this may be difficult to realize in the Sun because of magnetic buoyancy effects. Each of the above cases behaves similarly in higher and lower magnetic diffusivity regimes. However, our dynamo with a meridional circulation containing four cells in...
Atlantic Ocean circulation at the last glacial maximum : inferences from data and models
Dail, Holly Janine
2012-01-01T23:59:59.000Z
This thesis focuses on ocean circulation and atmospheric forcing in the Atlantic Ocean at the Last Glacial Maximum (LGM, 18-21 thousand years before present). Relative to the pre-industrial climate, LGM atmospheric CO? ...
deYoung, Brad
. INDEX TERMS: 4219 Oceanography: General: Continental shelf processes; 4255 Oceanography: General: Numerical modeling; 4223 Oceanography: General: Descriptive and regional oceanography; 4263 Oceanography of the quasi-stationary, or mean, circu- lation is a common challenge in oceanography. Despite some formal
Interactions between the Indonesian Throughflow and circulations in the Indian and Pacific Oceans
Jensen, Tommy
Interactions between the Indonesian Throughflow and circulations in the Indian and Pacific Oceans with the Indonesian Throughflow (IT), particularly concerning subsurface currents in the Pacific Ocean, are studied model (LOM), both confined to the Indo-Pacific basin; and a global, ocean general circulation model
Sherwood, Steven
a significant weakening(in NCW) or rearrangement(in NCWP) of the Walker circulation. Zonal mean cloud cover release is a nonlocal transfer of heat from the oceans to the atmosphere,while the radiative effects an atmosphericgeneral circulation model to radiative forcing of tropical clouds Steven C. Sherwood,· V. Ramanathan,·,2
Atmospheric Circulation Response to an Instantaneous Doubling of Carbon Dioxide. Part I: Model Experiments and Transient Thermal Response in the Troposphere* YUTIAN WU Department of Applied Physics (CO2) by looking into the transient step-by-step adjustment of the circulation. The transient
Model for Energy Supply System Alternatives and their General...
(Redirected from Model for Energy Supply System Alternatives and their General Environmental Impacts)...
Efficient inference in general semiparametric regression models
Maity, Arnab
2009-05-15T23:59:59.000Z
. Note that (2.17) means that the non-zero Y-data within an indi- vidual marginally have the same mean R T i ? 2 + ?(Z i ), variance ? 2 + ? 2 u2 and common covariance ? 2 u2 . II.4.2.3. Likelihood Function The collection of parameters is B, consisting... .............................. 4 II.1. Introduction ......................... 4 II.2. Semiparametric Models with a Single Component ..... 8 II.2.1. Main Results .................... 8 II.2.2. General Functions of the Response and Double- Robustness ..................... 11 II.3...
Vertical circulation and thermospheric composition: a modelling study H. Rishbeth1
Mueller-Wodarg, Ingo
-layer. At equinox, the vertical air motion is basically up by day, down by night, and the atomic oxygen is greater in winter than in summer, the semiannual anomaly exists if NmF2 is greater at equinox than by global-scale vertical and horizontal winds associated with a worldwide thermospheric circulation
Testing Generalized Linear Models Using Smoothing Spline Methods
Wang, Yuedong
the hypothesis of Generalized Linear Models (GLM) versus general smoothing spline models for data from exponential families. The tests developed are based on the connection between the smoothing spline models and residual plots are less informative for discrete data. Therefore general diagnostic and model building
Model for Energy Supply System Alternatives and their General...
Model for Energy Supply System Alternatives and their General Environmental Impacts (MESSAGE) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Model for Energy Supply...
EXTENSIONS OF GENERALIZED LINEAR MODELING APPROACH TO STOCHASTIC WEATHER GENERATORS
Katz, Richard
weather) -- Software R open source statistical programming language: Function glm "Family;(2) Generalized Linear Models Statistical Framework -- Multiple Regression Analysis (Linear model or LM) Response
General single phase wellbore flow model
Ouyang, Liang-Biao; Arbabi, S.; Aziz, K.
1997-02-05T23:59:59.000Z
A general wellbore flow model, which incorporates not only frictional, accelerational and gravitational pressure drops, but also the pressure drop caused by inflow, is presented in this report. The new wellbore model is readily applicable to any wellbore perforation patterns and well completions, and can be easily incorporated in reservoir simulators or analytical reservoir inflow models. Three dimensionless numbers, the accelerational to frictional pressure gradient ratio R{sub af}, the gravitational to frictional pressure gradient ratio R{sub gf}, and the inflow-directional to accelerational pressure gradient ratio R{sub da}, have been introduced to quantitatively describe the relative importance of different pressure gradient components. For fluid flow in a production well, it is expected that there may exist up to three different regions of the wellbore: the laminar flow region, the partially-developed turbulent flow region, and the fully-developed turbulent flow region. The laminar flow region is located near the well toe, the partially-turbulent flow region lies in the middle of the wellbore, while the fully-developed turbulent flow region is at the downstream end or the heel of the wellbore. Length of each region depends on fluid properties, wellbore geometry and flow rate. As the distance from the well toe increases, flow rate in the wellbore increases and the ratios R{sub af} and R{sub da} decrease. Consequently accelerational and inflow-directional pressure drops have the greatest impact in the toe region of the wellbore. Near the well heel the local wellbore flow rate becomes large and close to the total well production rate, here R{sub af} and R{sub da} are small, therefore, both the accelerational and inflow-directional pressure drops can be neglected.
Quaas, Johannes
2010-01-01T23:59:59.000Z
such as cloud contamination or 3D radiation effects (Loebeffect relationship behind the aerosol – cloud/radiationradiation resulting in the “aerosol direct effect”. Hy- drophilic aerosols can serve as cloud
Quaas, Johannes
2010-01-01T23:59:59.000Z
such as cloud contamination or 3D radiation effects (Loebeffect relationship behind the aerosol – cloud/radiationradiation resulting in the “aerosol direct effect”. Hy- drophilic aerosols can serve as cloud
Interactive chemistry in the Laboratoire de Meteorologie Dynamique general circulation model
Hourdin, Chez Frédéric
of soluble species. The global and annual mean methane (7.9 years) and methylchloroform (4.6 years) chemical chemical scheme representative of the background chemistry of the troposphere is considered. We derive rapid interhemispheric exchange times of 1.13 1.38 years and 0.700.82 years, based on surface
Farrara, J. D.; Yu, J.-Y.
2002-01-01T23:59:59.000Z
the recent notable Midwest summer flood ( drought) events ofdrought in particular—the rain- fall anomalies in the Midwest
Sun, Dezheng
that the bias is likely linked to a weaker relationship between the short-wave cloud forcing is a long-standing tropical bias in the CGCMs. The early hypotheses attribute this problem to the errors;4 errors may induce excessive equatorial upwelling upon coupling. The surface heating from the atmospheric
A preliminary model of the circulating blood for use in radiation dose calculations
Hui, Tsz-Yik Edmond
1986-01-01T23:59:59.000Z
. , 1968) "Distribution of Dose in the Body for a Source of Gamma Rays Distributed Uniformly in an Organ, " Oak Rdige National Laboratory, Oak Ridge, TN, ORNL-4168. Folkow B ~ and Neil E ~ g 1971' Circulation (New York: Oxford University Press... Phantom, Oak Ridge National Laboratory, Oak Ridge, TN, ORNL-TM-2250. Wa84 Watson E. E. , Stabin M. G. and Bolch W. E. , 1984, HIRDOSE, Oak Ridge Associated Universities, Oak Ridge/ TN. 53 Va80 van Reenen O. R. , Lotter M. G. , Minnaar P. C. , Heyns A...
Li, Zhiyong; Chen, Chao; Luo, Hailiang; Zhang, Ye; Xue, Yaning [College of Architecture and Civil Engineering, Beijing University of Technology, Beijing (China)
2010-08-15T23:59:59.000Z
The aim of this paper is to establish the heat transfer model of all-glass vacuum tube collector used in forced-circulation solar water heating system. In this model, the simplified heat transfer of collector is composed of the natural convection in single glass tube and forced flow in manifold header. Thus the heat balance equation of water in single tube and the heat balance equation of water in manifold header have been established. The flow equation is also built by analyzing the friction and buoyancy in tube. Through solved these equations the relationship between the collector average temperature, the outlet temperature and natural convection flow rate have been obtained. From this relationship and energy balance equation of collector, the collector outlet temperature can be calculated. The validated experiments of this model were carried out in winter of Beijing. (author)
Comparative Evaluation of Generalized River/Reservoir System Models
Wurbs, Ralph A.
This report reviews user-oriented generalized reservoir/river system models. The terms reservoir/river system, reservoir system, reservoir operation, or river basin management "model" or "modeling system" are used synonymously to refer to computer...
Hospital Readmission in General Medicine Patients: A Prediction Model
2010-01-01T23:59:59.000Z
to the department of medicine as a screening tool forquality of care problems. Medicine. 2008;87:294–300. 3.Readmission in General Medicine Patients: A Prediction Model
A GENERAL EMPIRICALLY BASED MICROINSTABILITY TRANSPORT MODEL
Vlad, Gregorio
by turbulent processes. At present, no definitive transport model (i.e. a closed expression for energygyro-Bohm, shear dependent thermal diffusion coefficient to model the anomalous thermal transport in tokamaks processes generated by small scale, collisionless, electro- static microinstabilities (Romanelli, F., Zonca
Vieira, Veronica M.; Weinberg, Janice M.; Webster, Thomas F.
2012-01-01T23:59:59.000Z
data using generalized additive modeling. BMC Public HealthTibshirani R: Generalized Additive Models. London: Chapmanapplication using generalized additive models. Int J Health
PRESERVING THE OCEAN CIRCULATION: IMPLICATIONS FOR CLIMATE POLICY
Morel, François M. M.
oceans. The posited collapse of this system could produce severe cooling in northwestern Europe, even collapse). This circulation system now warms north-western Europe and transports carbon dioxide to the deep when general global warming is in progress. In this paper we use a simple integrated assessment model
Valerio Lucarini; Antonio Speranza; Renato VItolo
2005-11-24T23:59:59.000Z
A quasi-geostrophic intermediate complexity model is considered, providing a schematic representation of the baroclinic conversion processes which characterize the physics of the mid-latitudes atmospheric circulation. The model is relaxed towards a given latitudinal temperature profile, which acts as baroclinic forcing, controlled by a parameter TE determining the forced equator-to-pole temperature gradient. As TE increases, a transition takes place from a stationary regime to a periodic regime, and eventually to an earth-like chaotic regime where evolution takes place on a strange attractor. The dependence of the attractor dimension, metric entropy, and bounding box volume in phase space is studied by varying both TE and model resolution. The statistical properties of observables having physical relevance, namely the total energy of the system and the latitudinally averaged zonal wind, are also examined. It is emphasized that while the attractor's properties are quite sensitive to model resolution, the global physical observables depend less critically on it. For more detailed physical observables, such as the latitudinal profiles of the zonal wind, model resolution again may be critical: the effectiveness of the zonal wind convergence, acting as barotropic stabilization of the baroclinic waves, heavily relies on the details of the latitudinal structure of the fields. The necessity and complementarity of both the dynamical systems and physical approach is underlined.
Generalized matrix models and AGT correspondence at all genera
Giulio Bonelli; Kazunobu Maruyoshi; Alessandro Tanzini; Futoshi Yagi
2011-07-11T23:59:59.000Z
We study generalized matrix models corresponding to n-point Virasoro conformal blocks on Riemann surfaces with arbitrary genus g. Upon AGT correspondence, these describe four dimensional N=2 SU(2)^{n+3g-3} gauge theories with generalized quiver diagrams. We obtain the generalized matrix models from the perturbative evaluation of the Liouville correlation functions and verify the consistency of the description with respect to degenerations of the Riemann surface. Moreover, we derive the Seiberg-Witten curve for the N=2 gauge theory as the spectral curve of the generalized matrix model, thus providing a check of AGT correspondence at all genera.
Droidel: A General Approach to Android Framework Modeling Sam Blackshear
Chang, Bor-Yuh Evan
Droidel: A General Approach to Android Framework Modeling Sam Blackshear University of Colorado.chang@colorado.edu Abstract We present an approach and tool for general-purpose modeling of Android for static analysis. Our approach is to explicate the reflective bridge between the Android framework and an application to make
Zalucha, Angela M. (Angela Marie)
2010-01-01T23:59:59.000Z
Previous work with Mars General Circulation Models (MGCMs) has shown that the north-south slope in Martian topography causes asymmetries in the Hadley cells at equinox and in the annual average. To quantitatively solve for ...
Generalized Conceptual Models Wetlands Regional Monitoring Program
to the selection of indicators and data collection, based upon conceptual models for how the target systems work. The data are interpreted as answers to the management questions, which then inform management actions #12;2 1. MANAGEMENT QUESTIONS DRIVE INDICATOR DEVELOPMENT The overarching wetland management questions
Intermediate-Generalized Chaplygin Gas inflationary universe model
Herrera, Ramon; Videla, Nelson
2013-01-01T23:59:59.000Z
An intermediate inflationary universe model in the context of a generalized Chaplygin gas is considered. For the matter we consider two different energy densities; a standard scalar field and a tachyon field, respectively. In general, we discuss the conditions of an inflationary epoch for these models. We also, use recent astronomical observations from Wilkinson Microwave Anisotropy Probe seven year data for constraining the parameters appearing in our models.
Generalized models and benchmarks for channel coordination
Toptal, Aysegul
2004-09-30T23:59:59.000Z
Models and Benchmarks for Channel Coordination. (August 2003) Ay¸ ¨ Toptal, B.S., Bilkent University, Turkey; M.S., Bilkent University, Turkey Chair of Advisory Committee: Dr. Sõla Cetinkaya This dissertation takes into account the latest industrial... of the Idea Behind Algorithm 3 . . . . . . . . . . . 58 12 Illustration of the Cost and Material Flows . . . . . . . . . . . . . 89 13 Illustration of Piv(Q) when (c -p)Pv > Rv . . . . . . . . . . . . . . 121 14 Different illustrations of Piv...
Generalized models and benchmarks for channel coordination
Toptal, Aysegul
2004-09-30T23:59:59.000Z
such as Vendor Managed Inventory ap- plications. With such new initiatives, substantial savings are realizable by carefully coordinating the operational decisions, such as procurement, transportation, inven- tory, and production decisions, for different... on buyer-vendor coordination problems. Recognizing a need for analytical research in the field, the dissertation then develops and solves centralized and decen- tralized models for complex buyer-vendor coordination problems with applications in supply...
NearCoM-TVD --A quasi-3D nearshore circulation and sediment transport model
Kirby, James T.
: Nearshore community model TVD-scheme Sediment transport Sandbar migration The newly developed nearshore migration events at Duck, NC, during August to October 1994 (Gallagher et al., 1998). The model of Kobayashi- line and about 10 m water depth. Hence, the applications of NearCoM to ocean-exposed coastal regions
Detecting thermohaline circulation changes from ocean properties in a coupled model
Hu, Aixue
three- dimensional water mass transport along with the atmospheric heating and cooling processes could induce significant cooling in the North Atlantic region, thus triggering a cooling event. [3 in THC and project its future status. 2. Model and Experiments [5] The model used in this study
Orthogonal Forward Regression based on Directly Maximizing Model Generalization Capability
Chen, Sheng
for costly model evaluation. Index Terms -- orthogonal forward regression, structure identification, cross struc- ture construction process as a cost function in order to op- timize the model generalization introduces a construction algorithm for sparse kernel modelling using the leave-one-out test score also known
The Transition-Zone Water Filter Model for Global Material Circulation: Where Do We Stand?
with a small melt fraction, highly incompatible elements including hydro- gen, helium and argon are sequestered the fraction of water is small. Models have been developed to understand the structure of a melt layer Hilst, et al., 1997]), then the whole mantle is depleted with only a small volume (~10%) of relatively
A three-dimensional surface waveocean circulation coupled model and its initial testing
Ezer,Tal
models is established based on Reynolds stresses and fluxes terms derived from surface wave to 0.93 with wave influence. The wave-induced Reynolds stress can reach up to about 5% of the wind stress in high latitudes, and drive 23 Sv transport in the global ocean in the form of mesoscale eddies
Seiberg-Witten curve via generalized matrix model
Kazunobu Maruyoshi; Futoshi Yagi
2010-12-27T23:59:59.000Z
We study the generalized matrix model which corresponds to the n-point toric Virasoro conformal block. This describes four-dimensional N=2 SU(2)^n gauge theory with circular quiver diagram by the AGT relation. We first verify that it is obtained from the perturbative calculation of the Liouville correlation function. We derive the Seiberg-Witten curve for N=2 gauge theory as a spectral curve of the generalized matrix model.
Song, Guodong
Previous experimental studies to assess the contribution of blood-borne circulating (BBC) cells to cutaneous wound healing have relied on discontinuous pulsing of labeled BBC elements or bone marrow transplant protocols. ...
A preliminary model of the circulating blood for use in radiation dose calculations
Hui, Tsz-Yik Edmond
1986-01-01T23:59:59.000Z
of Advisory Committee: Dr. John W. Poston Currently, there is a need for a dosimetric model to describe the circulatory system in an adult human. This need exists because of the increasing number of radiopharmaceuticals used in nuclear medicine which... Administered Activity for Indium-113m-labeled Blood Platelets for Selected Organs biological data on blood volume and distribution in the circulatory system (A163, Ba61, Co71, Fo71, Sm84, Mc74) . Only major organs that contain large amounts of blood were...
Early Warning Signals for Critical Transitions: A Generalized Modeling Approach
for early warning signals that integrates multiple sources of information and data about the system throughEarly Warning Signals for Critical Transitions: A Generalized Modeling Approach Steven J. Lade a previously published fisheries model. We regard our method as complementary to existing early warning signals
Bleck, R.
2004-05-19T23:59:59.000Z
The overall aim of this project was to continue development of a global version of the Miami Isopycnic Coordinate Ocean Model (MICOM) with the intent of turning it into a full-fledged oceanic component of an earth system model.
Generalization of neuron network model with delay feedback
Sanjeet Maisnam; R. K. Brojen Singh
2015-07-16T23:59:59.000Z
We present generalized delayed neural network (DNN) model with positive delay feedback and neuron history. The local stability analysis around trivial local equilibria of delayed neural networks has applied and determine the conditions for the existence of zero root. We develop few innovative delayed neural network models in different dimensions through transformation and extension of some existing models. We found that zero root can have multiplicity two under certain conditions. We further show how the characteristic equation can have zero root and its multiplicity is dependent on the conditions undertaken. Finally, we generalize the neural network of $N$ neurons through which we determine the general form of Jacobian of the linear form and corresponding characteristic equation of the system.
General Treatment of All 2d Covariant Models
W. Kummer
1996-12-06T23:59:59.000Z
General matterless models of gravity include dilaton gravity, arbitrary powers in curvature, but also dynamical torsion. They are a special class of "Poisson-sigma-models" whose solutions are known completely, together with their general global structure. Beside the ordinary black hole, arbitrary singularity structures can be studied. It is also possible to derive an action "backwards", starting from a given manifold. The role of conservation laws, Noether charge and the quantization have been investigated. Scalar and fermionic matter fields may be included as well.
Modeling Smart Grid using Generalized Stochastic Petri Net
Dey, Amrita; Sanyal, Sugata
2011-01-01T23:59:59.000Z
Building smart grid for power system is a major challenge for safe, automated and energy efficient usage of electricity. The full implementation of the smart grid will evolve over time. However, before a new set of infrastructures are invested to build the smart grid, proper modeling and analysis is needed to avoid wastage of resources. Modeling also helps to identify and prioritize appropriate systems parameters. In this paper, an all comprehensive model of smart grid have been proposed using Generalized Stochastic Petri Nets (GSPN). The model is used to analyze the constraints and deliverables of the smart power grid of future.
Interacting holographic dark energy models: A general approach
S. Som; A. Sil
2014-12-01T23:59:59.000Z
Dark energy models inspired by the cosmological holographic principle are studied in homogeneous isotropic spacetime with a general choice for the dark energy density $\\rho_d=3(\\alpha H^2+\\beta\\dot{H})$. Special choices of the parameters enable us to obtain three different holographic models, including the holographic Ricci dark energy(RDE) model. Effect of interaction between dark matter and dark energy on the dynamics of those models are investigated for different popular forms of interaction. It is found that crossing of phantom divide can be avoided in RDE models for $\\beta>0.5$ irrespective of the presence of interaction. A choice of $\\alpha=1$ and $\\beta=2/3$ leads to a varying $\\Lambda$-like model introducing an IR cutoff length $\\Lambda^{-1/2}$. It is concluded that among the popular choices an interaction of the form $Q\\propto H\\rho_m$ suits the best in avoiding the coincidence problem in this model.
A-model and generalized Chern-Simons theory
A. Schwarz
2005-01-30T23:59:59.000Z
The relation between open topological strings and Chern-Simons theory was discovered by E. Witten. He proved that A-model on T*M where M is a three-dimensional manifold is equivalent to Chern-Simons theory on M and that A-model on arbitrary Calabi-Yau 3-fold is related to Chern-Simons theory with instanton corrections. In present paper we discuss multidimensional generalization of these results.
New agegraphic dark energy model with generalized uncertainty principle
Yong-Wan Kim; Hyung Won Lee; Yun Soo Myung; Mu-In Park
2008-08-07T23:59:59.000Z
We investigate the new agegraphic dark energy models with generalized uncertainty principle (GUP). It turns out that although the GUP affects the early universe, it does not change the current and future dark energy-dominated universe significantly. Furthermore, this model could describe the matter-dominated universe in the past only when the parameter $n$ is chosen to be $n>n_c$, where the critical value determined to be $n_c=2.799531478$.
GENERALIZED STIRLING PERMUTATIONS, FAMILIES OF INCREASING TREES AND URN MODELS
Janson, Svante
GENERALIZED STIRLING PERMUTATIONS, FAMILIES OF INCREASING TREES AND URN MODELS SVANTE JANSON and descents in the class of Stirling permutations, introduced by Gessel and Stanley [14]. Recently, Janson [18] showed the connection between Stirling permutations and plane recursive trees and proved a joint nor- mal
GENERALIZED LINEAR MODELING APPROACH TO STOCHASTIC WEATHER GENERATORS
Katz, Richard
) Multisites (Spatial dependence of daily weather) -- Software R open source statistical programming language (Capable of "reproducing" any desired statistic) -- Disadvantages Synthetic weather looks too much like") Not amenable to uncertainty analysis #12;#12;#12;(2) Generalized Linear Models · Statistical Framework
A General Method for Feature Matching and Model Extraction
Olson, Clark F.
A General Method for Feature Matching and Model Extraction Clark F. Olson Jet Propulsion Laboratory is extracted from or #12;t to data that draws bene#12;ts from both generate-and-test methods and those based that are ecient and robust. We apply this method to object recognition, geometric primitive extraction, robust
Abstract polymer models with general pair interactions Aldo Procacci
Procacci, Aldo
Abstract polymer models with general pair interactions Aldo Procacci Dep. MatemÂ´atica-ICEx, UFMG (i.e. not necessarily hard core or repulsive). A concrete example is given in which polymers are r0 (possibly attractive), of the type 1/rd+ with > 0. 1. Introduction The abstract polymer gas is an important
General Network Lifetime and Cost Models for Evaluating Sensor Network
Heinzelman, Wendi
General Network Lifetime and Cost Models for Evaluating Sensor Network Deployment Strategies Zhao Cheng, Mark Perillo, and Wendi B. Heinzelman, Senior Member, IEEE Abstract--In multihop wireless sensor to energy imbalance among sensors often appear. Sensors closer to a data sink are usually required
A general holographic metal/superconductor phase transition model
Yan Peng; Yunqi Liu
2015-03-03T23:59:59.000Z
We study the scalar condensation of a general holographic superconductor model in AdS black hole background away from the probe limit. We find the model parameters together with the scalar mass and backreaction can determine the order of phase transitions completely. In addition, we observe two types of discontinuities of the scalar operator in the case of first order phase transitions. We analyze in detail the effects of the scalar mass and backreaction on the formation of discontinuities and arrive at an approximate relation between the threshold model parameters. Furthermore, we obtain superconductor solutions corresponding to higher energy states and examine the stability of these superconductor solutions.
Spontaneous symmetry breaking in a generalized orbital compass model
Lukasz Cincio; Jacek Dziarmaga; Andrzej M. Oles
2010-09-10T23:59:59.000Z
We introduce a generalized two-dimensional orbital compass model, which interpolates continuously from the classical Ising model to the orbital compass model with frustrated quantum interactions, and investigate it using the multiscale entanglement renormalization ansatz (MERA). The results demonstrate that increasing frustration of exchange interactions triggers a second order quantum phase transition to a degenerate symmetry broken state which minimizes one of the interactions in the orbital compass model. Using boson expansion within the spin-wave theory we unravel the physical mechanism of the symmetry breaking transition as promoted by weak quantum fluctuations and explain why this transition occurs only surprisingly close to the maximally frustrated interactions of the orbital compass model. The spin waves remain gapful at the critical point, and both the boson expansion and MERA do not find any algebraically decaying spin-spin correlations in the critical ground state.
Simple ocean carbon cycle models
Caldeira, K. [Lawrence Livermore National Lab., CA (United States); Hoffert, M.I. [New York Univ., NY (United States). Dept. of Earth System Sciences; Siegenthaler, U. [Bern Univ. (Switzerland). Inst. fuer Physik
1994-02-01T23:59:59.000Z
Simple ocean carbon cycle models can be used to calculate the rate at which the oceans are likely to absorb CO{sub 2} from the atmosphere. For problems involving steady-state ocean circulation, well calibrated ocean models produce results that are very similar to results obtained using general circulation models. Hence, simple ocean carbon cycle models may be appropriate for use in studies in which the time or expense of running large scale general circulation models would be prohibitive. Simple ocean models have the advantage of being based on a small number of explicit assumptions. The simplicity of these ocean models facilitates the understanding of model results.
B Decays in a General Left-Right Symmetric Model
Frank, Mariana; Turan, Ismail
2010-01-01T23:59:59.000Z
Motivated by recently observed disagreements with the SM predictions in B decays, we study $b \\to d, s$ transitions in a general class of $SU(2)_L \\times SU(2)_R \\times U(1)_{B-L}$ models, with a simple one-parameter structure of the right handed mixing matrix for the quarks, which obeys the constraints from kaon physics. We use experimental constraints on the branching ratios of $b \\to s \\gamma$, $b \\to c e {\\bar \
Exceptional and regular spectra of a generalized Rabi model
Michael Tomka; Omar El Araby; Mikhail Pletyukhov; Vladimir Gritsev
2014-12-05T23:59:59.000Z
We study the spectrum of the generalized Rabi model in which co- and counter-rotating terms have different coupling strengths. It is also equivalent to the model of a two-dimensional electron gas in a magnetic field with Rashba and Dresselhaus spin-orbit couplings. Like in case of the Rabi model, the spectrum of the generalized Rabi model consists of the regular and the exceptional parts. The latter is represented by the energy levels which cross at certain parameters' values which we determine explicitly. The wave functions of these exceptional states are given by finite order polynomials in the Bargmann representation. The roots of these polynomials satisfy a Bethe ansatz equation of the Gaudin type. At the exceptional points the model is therefore quasi-exactly solvable. An analytical approximation is derived for the regular part of the spectrum in the weak- and strong-coupling limits. In particular, in the strong-coupling limit the spectrum consists of two quasi-degenerate equidistant ladders.
A dark energy model alternative to generalized Chaplygin gas
Hoavo Hova; Huanxiong Yang
2010-11-22T23:59:59.000Z
We propose a new fluid model of dark energy for $-1 \\leq \\omega_{\\text{eff}} \\leq 0$ as an alternative to the generalized Chaplygin gas models. The energy density of dark energy fluid is severely suppressed during barotropic matter dominant epochs, and it dominates the universe evolution only for eras of small redshift. From the perspective of fundamental physics, the fluid is a tachyon field with a scalar potential flatter than that of power-law decelerated expansion. Different from the standard $\\Lambda\\text{CDM}$ model, the suggested dark energy model claims that the cosmic acceleration at present epoch can not continue forever but will cease in the near future and a decelerated cosmic expansion will recover afterwards.
A dark energy model alternative to generalized Chaplygin gas
Hova, Hoavo
2010-01-01T23:59:59.000Z
We propose a new fluid model of dark energy for $-1 \\leq \\omega_{\\text{eff}} \\leq 0$ as an alternative to the generalized Chaplygin gas models. The energy density of dark energy fluid is severely suppressed during barotropic matter dominant epochs, and it dominates the universe evolution only for eras of small redshift. From the perspective of fundamental physics, the fluid is a tachyon field with a scalar potential flatter than that of power-law decelerated expansion. Different from the standard $\\Lambda\\text{CDM}$ model, the suggested dark energy model claims that the cosmic acceleration at present epoch can not continue forever but will cease in the near future and a decelerated cosmic expansion will recover afterwards.
Long-term effects of anthropogenic CO2 emissions simulated with a complex earth system model
Winguth, Arne
Long-term effects of anthropogenic CO2 emissions simulated with a complex earth system model Uwe earth system model con- sisting of an atmospheric general circulation model, an ocean general
$so(N)_1$ criticality in generalized cluster models
Ville Lahtinen; Eddy Ardonne
2015-04-27T23:59:59.000Z
We show that $so(N)_1$ universality class quantum criticality emerges when one-dimensional generalized cluster models -- the N-cluster models -- are perturbed with Ising or Zeeman terms. Each critical point is described by a low-energy theory of N linearly dispersing fermions, whose spectrum we show to precisely match the prediction by $so(N)_1$ conformal field theory. Furthermore, by an explicit construction we show that the N-cluster models are dual to N non-locally coupled transverse field Ising chains, which enables to identify local representations for the primary fields and shows that the N-cluster models provide the simplest representation of the recently introduced hierarchy of $so(N)_1$ critical spin models. For the experimentally most realistic case of N=3, that corresponds to the original one-dimensional cluster model, our results show that $su(2)_2 \\simeq so(3)_1$ Wess-Zumino-Witten model can emerge in a local, translationally invariant and Jordan-Wigner solvable spin-1/2 model.
Reshocks, rarefactions, and the generalized Layzer model for hydrodynamic instabilities
Mikaelian, K O
2008-06-10T23:59:59.000Z
We report numerical simulations and analytic modeling of shock tube experiments on Rayleigh-Taylor and Richtmyer-Meshkov instabilities. We examine single interfaces of the type A/B where the incident shock is initiated in A and the transmitted shock proceeds into B. Examples are He/air and air/He. In addition, we study finite-thickness or double-interface A/B/A configurations like air/SF{sub 6}/air gas-curtain experiments. We first consider conventional shock tubes that have a 'fixed' boundary: A solid endwall which reflects the transmitted shock and reshocks the interface(s). Then we focus on new experiments with a 'free' boundary--a membrane disrupted mechanically or by the transmitted shock, sending back a rarefaction towards the interface(s). Complex acceleration histories are achieved, relevant for Inertial Confinement Fusion implosions. We compare our simulation results with a generalized Layzer model for two fluids with time-dependent densities, and derive a new freeze-out condition whereby accelerating and compressive forces cancel each other out. Except for the recently reported failures of the Layzer model, the generalized Layzer model and hydrocode simulations for reshocks and rarefactions agree well with each other, and remain to be verified experimentally.
A General Approach to the Modelling of Trophic Chains
Rui Dilao; Tiago Domingos
1999-02-10T23:59:59.000Z
Based on the law of mass action (and its microscopic foundation) and mass conservation, we present here a method to derive consistent dynamic models for the time evolution of systems with an arbitrary number of species. Equations are derived through a mechanistic description, ensuring that all parameters have ecological meaning. After discussing the biological mechanisms associated to the logistic and Lotka-Volterra equations, we show how to derive general models for trophic chains, including the effects of internal states at fast time scales. We show that conformity with the mass action law leads to different functional forms for the Lotka-Volterra and trophic chain models. We use mass conservation to recover the concept of carrying capacity for an arbitrary food chain.
Perturbations in Bouncing and Cyclic Models, a General Study
Biswas, Tirthabir; Lattyak, Colleen
2015-01-01T23:59:59.000Z
Being able to reliably track perturbations across bounces and turnarounds in cyclic and bouncing cosmology lies at the heart of being able to compare the predictions of these models with the Cosmic Microwave Background observations. This has been a challenging task due to the unknown nature of the physics involved during the bounce as well as the technical challenge of matching perturbations precisely between the expansion and contraction phases. In this paper, we will present general techniques (analytical and numerical) that can be applied to understand the physics of the fluctuations, especially those with "long" wavelengths, and test its validity in some simple bouncing/cyclic toy models where the physics is well understood. We will then apply our techniques to more interesting cosmological models such as the bounce inflation and cyclic inflation.
Perturbations in Bouncing and Cyclic Models, a General Study
Tirthabir Biswas; Riley Mayes; Colleen Lattyak
2015-02-18T23:59:59.000Z
Being able to reliably track perturbations across bounces and turnarounds in cyclic and bouncing cosmology lies at the heart of being able to compare the predictions of these models with the Cosmic Microwave Background observations. This has been a challenging task due to the unknown nature of the physics involved during the bounce as well as the technical challenge of matching perturbations precisely between the expansion and contraction phases. In this paper, we will present general techniques (analytical and numerical) that can be applied to understand the physics of the fluctuations, especially those with "long" wavelengths, and test its validity in some simple bouncing/cyclic toy models where the physics is well understood. We will then apply our techniques to more interesting cosmological models such as the bounce inflation and cyclic inflation.
Goodness-of-Fit Test Issues in Generalized Linear Mixed Models
Chen, Nai-Wei
2012-02-14T23:59:59.000Z
Linear mixed models and generalized linear mixed models are random-effects models widely applied to analyze clustered or hierarchical data. Generally, random effects are often assumed to be normally distributed in the ...
as they are actually a strong limitation in assimilation performance when assimilating any real data set. INDEX TERMS Caledonia, France Jacques Verron Laboratoire des Ecoulements Ge´ophysiques et Industriels, Centre National must be taken into proper account in conjunction with temperature and altimetric data. The sensitivity
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
Electromagnetic Mass Models in General Theory of Relativity
Sumana Bhadra
2007-10-30T23:59:59.000Z
"Electromagnetic mass" where gravitational mass and other physical quantities originate from the electromagnetic field alone has a century long distinguished history. In the introductory chapter we have divided this history into three broad categories -- classical, quantum mechanical and general relativistic. Each of the categories has been described at a length to get the detailed picture of the physical background. Recent developments on Repulsive Electromagnetic Mass Models are of special interest in this introductory part of the thesis. In this context we have also stated motivation of our work. In the subsequent chapters we have presented our results and their physical significances. It is concluded that the electromagnetic mass models which are the sources of purely electromagnetic origin ``have not only heuristic flavor associated with the conjecture of Lorentz but even a physics having unconventional yet novel features characterizing their own contributions independent of the rest of the physics".
Generalized Modeling of Enrichment Cascades That Include Minor Isotopes
Weber, Charles F [ORNL
2012-01-01T23:59:59.000Z
The monitoring of enrichment operations may require innovative analysis to allow for imperfect or missing data. The presence of minor isotopes may help or hurt - they can complicate a calculation or provide additional data to corroborate a calculation. However, they must be considered in a rigorous analysis, especially in cases involving reuse. This study considers matched-abundanceratio cascades that involve at least three isotopes and allows generalized input that does not require all feed assays or the enrichment factor to be specified. Calculations are based on the equations developed for the MSTAR code but are generalized to allow input of various combinations of assays, flows, and other cascade properties. Traditional cascade models have required specification of the enrichment factor, all feed assays, and the product and waste assays of the primary enriched component. The calculation would then produce the numbers of stages in the enriching and stripping sections and the remaining assays in waste and product streams. In cases where the enrichment factor or feed assays were not known, analysis was difficult or impossible. However, if other quantities are known (e.g., additional assays in waste or product streams), a reliable calculation is still possible with the new code, but such nonstandard input may introduce additional numerical difficulties into the calculation. Thus, the minimum input requirements for a stable solution are discussed, and a sample problem with a non-unique solution is described. Both heuristic and mathematically required guidelines are given to assist the application of cascade modeling to situations involving such non-standard input. As a result, this work provides both a calculational tool and specific guidance for evaluation of enrichment cascades in which traditional input data are either flawed or unknown. It is useful for cases involving minor isotopes, especially if the minor isotope assays are desired (or required) to be important contributors to the overall analysis.
Control of a Circulating Fluidized Bed
Shim, Hoowang; Rickards, Gretchen; Famouri, Parviz; Turton, Richard (WVU); Sams, W. Neal (EG& G); Koduro, Praveen; Patankar, Amol; Davari, Assad (WVUIT); Lawson, Larry; Boyle, Edward J. (DOE)
2001-11-06T23:59:59.000Z
Two methods for optimally controlling the operation of a circulating fluidized bed are being investigated, neural network control and Kalman filter control. The neural network controls the solids circulation rate by adjusting the flow of move air in the non-mechanical valve. Presented is the method of training the neural network from data generated by the circulating fluidized bed (CFB), the results of a sensitivity study indicating that adjusting the move air can control solids flow, and the results of controlling solids circulation rate. The Kalman filter approach uses a dynamic model and a measurement model of the standpipe section of the CFB. Presented are results showing that a Kalman filter can successfully find the standpipe bed height.
Circulating Fluid Bed Combustor
Fraley, L. D.; Do, L. N.; Hsiao, K. H.
1982-01-01T23:59:59.000Z
The circulating bed combustor represents an alternative concept of burning coal in fluid bed technology, which offers distinct advantages over both the current conventional fluidized bed combustion system and the pulverized coal boilers equipped...
Proton radioactivity within a generalized liquid drop model
J. M. Dong; H. F. Zhang; G. Royer
2009-06-02T23:59:59.000Z
The proton radioactivity half-lives of spherical proton emitters are investigated theoretically. The potential barriers preventing the emission of protons are determined in the quasimolecular shape path within a generalized liquid drop model (GLDM) including the proximity effects between nuclei in a neck and the mass and charge asymmetry. The penetrability is calculated with the WKB approximation. The spectroscopic factor has been taken into account in half-life calculation, which is obtained by employing the relativistic mean field (RMF) theory combined with the BCS method with the force NL3. The half-lives within the GLDM are compared with the experimental data and other theoretical values. The GLDM works quite well for spherical proton emitters when the spectroscopic factors are considered, indicating the necessity of introducing the spectroscopic factor and the success of the GLDM for proton emission. Finally, we present two formulas for proton emission half-life calculation similar to the Viola-Seaborg formulas and Royer's formulas of alpha decay.
Interacting generalized Chaplygin gas model in non-flat universe
M R Setare
2007-11-04T23:59:59.000Z
We employ the generalized Chaplygin gas of interacting dark energy to obtain the equation of state for the generalized Chaplygin gas energy density in non-flat universe. By choosing a negative value for $B$ we see that $w_{\\rm \\Lambda}^{eff}universe dominated by phantom dark energy.
Generalized charge-screening in relativistic Thomas–Fermi model
Akbari-Moghanjoughi, M. [Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, 51745-406 Tabriz, Iran and International Centre for Advanced Studies in Physical Sciences and Institute for Theoretical Physics, Ruhr University Bochum, D-44780 Bochum (Germany)
2014-10-15T23:59:59.000Z
In this paper, we study the charge shielding within the relativistic Thomas-Fermi model for a wide range of electron number-densities and the atomic-number of screened ions. A generalized energy-density relation is obtained using the force-balance equation and taking into account the Chandrasekhar's relativistic electron degeneracy pressure. By numerically solving a second-order nonlinear differential equation, the Thomas-Fermi screening length is investigated, and the results are compared for three distinct regimes of the solid-density, warm-dense-matter, and white-dwarfs (WDs). It is revealed that our nonlinear screening theory is compatible with the exponentially decaying Thomas-Fermi-type shielding predicted by the linear response theory. Moreover, the variation of relative Thomas-Fermi screening length shows that extremely dense quantum electron fluids are relatively poor charge shielders. Calculation of the total number of screening electrons around a nucleus shows that there is a position of maximum number of screening localized electrons around the screened nucleus, which moves closer to the point-like nucleus by increase in the plasma number density but is unaffected due to increase in the atomic-number value. It is discovered that the total number of screening electrons, (N{sub s}?r{sub TF}{sup 3}/r{sub d}{sup 3} where r{sub TF} and r{sub d} are the Thomas-Fermi and interparticle distance, respectively) has a distinct limit for extremely dense plasmas such as WD-cores and neutron star crusts, which is unique for all given values of the atomic-number. This is equal to saying that in an ultrarelativistic degeneracy limit of electron-ion plasma, the screening length couples with the system dimensionality and the plasma becomes spherically self-similar. Current analysis can provide useful information on the effects of relativistic correction to the charge screening for a wide range of plasma density, such as the inertial-confined plasmas and compact stellar objects.
van Hulten, Marco; Middag, Rob; de Baar, Hein; Gehlen, Marion; Dutay, Jean-Claude; Tagliabue, Alessandro
2014-01-01T23:59:59.000Z
The distribution of dissolved aluminium in the West Atlantic Ocean shows a mirror image with that of dissolved silicic acid, hinting at intricate interactions between the ocean cycling of Al and Si. The marine biogeochemistry of Al is of interest because of its potential impact on diatom opal remineralisation, hence Si availability. Furthermore, the dissolved Al concentration at the surface ocean has been used as a tracer for dust input, dust being the most important source of the bio-essential trace element iron to the ocean. Previously, the dissolved concentration of Al was simulated reasonably well with only a dust source, and scavenging by adsorption on settling biogenic debris as the only removal process. Here we explore the impacts of (i) a sediment source of Al in the Northern Hemisphere (especially north of ~40{\\deg}N), (ii) the imposed velocity field, and (iii) biological incorporation of Al on the modelled Al distribution in the ocean. The sediment source clearly improves the model results, and usin...
Autumn 2014 Atmospheric Circulation
Doty, Sharon Lafferty
to perform atmospheric chemistry measurements in this remote region of ubiquitous oil and gas drilling the hypothesisofsnowchemistrybeinganimportant contributor to the ozone problem in Utah during the Atmospheric Chemistry Gordon ConferenceAutumn 2014 Atmospheric Circulation Newsletter of the University of Washington Atmospheric Sciences
Circulating Fluid Bed Combustor
Fraley, L. D.; Do, L. N.; Hsiao, K. H.
1982-01-01T23:59:59.000Z
with flue gas desulfurization. This paper presents the conceptual design of a circulating fluidized bed coal combustor to be used as a steam generator for a power plant. The design variables are selected to optimize the combustor's performance, size and cost...
The Transient Circulation Response to Radiative Forcings and Sea Surface Warming
Staten, Paul; Reichler, Thomas; Lu, Jian
2014-12-15T23:59:59.000Z
Tropospheric circulation shifts have strong potential to impact surface climate. But the magnitude of these shifts in a changing climate, and the attending regional hydrological changes, are difficult to project. Part of this difficulty arises from our lack of understanding of the physical mechanisms behind the circulation shifts themselves. In order to better delineate circulation shifts and their respective causes, we decompose the circulation response into (1) the "direct" response to radiative forcings themselves, and (2) the "indirect" response to changing sea surface temperatures. Using ensembles of 90-day climate model simulations with immediate switch-on forcings, including perturbed greenhouse gas concentrations, stratospheric ozone concentrations, and sea surface temperatures, we document the direct and indirect transient responses of the zonal mean general circulation, and investigate the roles of previously proposed mechanisms in shifting the midlatitude jet. We find that both the direct and indirect wind responses often begin in the lower stratosphere. Changes in midlatitude eddies are ubiquitous and synchronous with the midlatitude zonal wind response. Shifts in the critical latitude of wave absorption on either flank of the jet are not indicted as primary factors for the poleward shifting jet, although we see some evidence for increasing equatorward wave reflection over the southern hemisphere in response to sea surface warming. Mechanisms for the northern hemisphere jet shift are less clear.
General coarse-grained red blood cell models: I. Mechanics
Fedosov, Dmitry A; Karniadakis, George E
2009-01-01T23:59:59.000Z
We present a rigorous procedure to derive coarse-grained red blood cell (RBC) models, which lead to accurate mechanical properties of realistic RBCs. Based on a semi-analytic theory linear and non-linear elastic properties of the RBC membrane can be matched with those obtained in optical tweezers stretching experiments. In addition, we develop a nearly stress-free model which avoids a number of pitfalls of existing RBC models, such as non-biconcave equilibrium shape and dependence of RBC mechanical properties on the triangulation quality. The proposed RBC model is suitable for use in many existing numerical methods, such as Lattice Boltzmann, Multiparticle Collision Dynamics, Immersed Boundary, etc.
General coarse-grained red blood cell models: I. Mechanics
Dmitry A. Fedosov; Bruce Caswell; George E. Karniadakis
2009-05-01T23:59:59.000Z
We present a rigorous procedure to derive coarse-grained red blood cell (RBC) models, which lead to accurate mechanical properties of realistic RBCs. Based on a semi-analytic theory linear and non-linear elastic properties of the RBC membrane can be matched with those obtained in optical tweezers stretching experiments. In addition, we develop a nearly stress-free model which avoids a number of pitfalls of existing RBC models, such as non-biconcave equilibrium shape and dependence of RBC mechanical properties on the triangulation quality. The proposed RBC model is suitable for use in many existing numerical methods, such as Lattice Boltzmann, Multiparticle Collision Dynamics, Immersed Boundary, etc.
Lost circulation in geothermal wells: survey and evaluation of industry experience
Goodman, M.A.
1981-07-01T23:59:59.000Z
Lost circulation during drilling and completion of geothermal wells can be a severe problem, particularly in naturally fractured and/or vugular formations. Geothermal and petroleum operators, drilling service companies, and independent consultants were interviewed to assess the lost circulation problem in geothermal wells and to determine general practices for preventing lost circulation. This report documents the results and conclusions from the interviews and presents recommendations for needed research. In addition, a survey was also made of the lost circulation literature, of currently available lost circulation materials, and of existing lost circulation test equipment.
General Methodology for developing UML models from UI
Reddy, Ch Ram Mohan; Srinivasa, K G; Kumar, T V Suresh; Kanth, K Rajani
2012-01-01T23:59:59.000Z
In recent past every discipline and every industry have their own methods of developing products. It may be software development, mechanics, construction, psychology and so on. These demarcations work fine as long as the requirements are within one discipline. However, if the project extends over several disciplines, interfaces have to be created and coordinated between the methods of these disciplines. Performance is an important quality aspect of Web Services because of their distributed nature. Predicting the performance of web services during early stages of software development is significant. In Industry, Prototype of these applications is developed during analysis phase of Software Development Life Cycle (SDLC). However, Performance models are generated from UML models. Methodologies for predicting the performance from UML models is available. Hence, In this paper, a methodology for developing Use Case model and Activity model from User Interface is presented. The methodology is illustrated with a case...
Shelf circulation patterns off Nigeria
Rider, Kelly Elizabeth
2005-08-29T23:59:59.000Z
Little has been published about the shelf circulation off the coast of Nigeria. Due to increased activity and associated incidents in the shallow waters offshore Nigeria, there is a need to more clearly define the near-shore circulation patterns...
From residue matching patterns to protein folding topographies: General model and bovine
Berry, R. Stephen
From residue matching patterns to protein folding topographies: General model and bovine pancreatic-grained model for protein-folding dynamics is introduced based on a discretized representation of torsional, pattern recognition, and general characteristics of protein folding kinetics. Topology here implies
A generalized logistic model of individual tree mortality for aspen, white spruce, and lodgepole
Macdonald, Ellen
A generalized logistic model of individual tree mortality for aspen, white spruce, and lodgepole: A generalized logistic model of individual tree mortality was developed for trembling aspen (Populus tremuloides aspen (Populus tremuloides Michx), white spruce (Picea glauca (Moench) Voss), and lodgepole pine (Pinus
General Equilibrium Modeling Package (GEMPACK) | Open Energy Information
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 Data Center Home Page on DeliciousPlasmaP a g eWorksVillagesourceEuromoneyForest City MilitaryFrisco,Gary WindsourceGeneral Compression
Dark Energy - Dark Matter Unification: Generalized Chaplygin Gas Model
Orfeu Bertolami
2005-04-14T23:59:59.000Z
We review the main features of the generalized Chaplygin gas (GCG) proposal for unification of dark energy and dark matter and discuss how it admits an unique decomposition into dark energy and dark matter components once phantom-like dark energy is excluded. In the context of this approach we consider structure formation and show that unphysical oscillations or blow-up in the matter power spectrum are not present. Moreover, we demonstrate that the dominance of dark energy occurs about the time when energy density fluctuations start evolving away from the linear regime.
Generalized Ginzburg-Landau models for non-conventional superconductors
S. Esposito; G. Salesi
2009-06-20T23:59:59.000Z
We review some recent extensions of the Ginzburg-Landau model able to describe several properties of non-conventional superconductors. In the first extension, s-wave superconductors endowed with two different critical temperatures are considered, their main thermodynamical and magnetic properties being calculated and discussed. Instead in the second extension we describe spin-triplet superconductivity (with a single critical temperature), studying in detail the main predicted physical properties. A thorough discussion of the peculiar predictions of our models and their physical consequences is as well performed.
Modelling general relativistic perfect fluids in field theoretic language
Nikolai V. Mitskievich
1998-11-23T23:59:59.000Z
Skew-symmetric massless fields, their potentials being $r$-forms, are close analogues of Maxwell's field (though the non-linear cases also should be considered). We observe that only two of them ($r=$2 and 3) automatically yield stress-energy tensors characteristic to normal perfect fluids. It is shown that they naturally describe both non-rotating ($r=2$) and rotating (then a combination of $r=2$ and $r=3$ fields is indispensable) general relativistic perfect fluids possessing every type of equations of state. Meanwile, a free $r=3$ field is completely equivalent to appearance of the cosmological term in Einstein's equations. Sound waves represent perturbations propagating on the background of the $r=2$ field. Some exotic properties of these two fields are outlined.
Oliker, Leonid
of anthropogenic climate change are highly dependent on cloud-radiation interactions. In this paper, we Keywords Climate model, atmospheric general circulation model, finite volume model, global warming scientists today, with economic ramifications in the trillions of dollars. Effectively performing
Numerical Simulation of a Natural Circulation Steam Generator
Weinmüller, Ewa B.
Numerical Simulation of a Natural Circulation Steam Generator W. Linzer \\Lambda , K. Ponweiser circulation steam generator. We focus on a model with a simple geometry consisting of two vertical pipes properties of water and steam. We present a numerical algorithm based on an explicit upwind discretization
Independent review of SCDAP/RELAP5 natural circulation calculations
Martinez, G.M.; Gross, R.J.; Martinez, M.J.; Rightley, G.S.
1994-01-01T23:59:59.000Z
A review and assessment of the uncertainties in the calculated response of reactor coolant system natural circulation using the SCDAP/RELAP5 computer code were completed. The SCDAP/RELAP5 calculation modeled a station blackout transient in the Surry nuclear power plant and concluded that primary system depressurization from natural circulation induced primary system failure is more likely than previously thought.
A new eight vertex model and higher dimensional, multiparameter generalizations
B. Abdesselam; A. Chakrabarti
2008-02-12T23:59:59.000Z
We study statistical models, specifically transfer matrices corresponding to a multiparameter hierarchy of braid matrices of $(2n)^2\\times(2n)^2$ dimensions with $2n^2$ free parameters $(n=1,2,3,...)$. The simplest, $4\\times 4$ case is treated in detail. Powerful recursion relations are constructed giving the dependence on the spectral parameter $\\theta$ of the eigenvalues of the transfer matrix explicitly at each level of coproduct sequence. A brief study of higher dimensional cases ($n\\geq 2$) is presented pointing out features of particular interest. Spin chain Hamiltonians are also briefly presented for the hierarchy. In a long final section basic results are recapitulated with systematic analysis of their contents. Our eight vertex $4\\times 4$ case is compared to standard six vertex and eight vertex models.
System Advisor Model, SAM 2014.1.14: General Description
Blair, N.; Dobos, A. P.; Freeman, J.; Neises, T.; Wagner, M.; Ferguson, T.; Gilman, P.; Janzou, S.
2014-02-01T23:59:59.000Z
This document describes the capabilities of the U.S. Department of Energy and National Renewable Energy Laboratory's System Advisor Model (SAM), Version 2013.9.20, released on September 9, 2013. SAM is a computer model that calculates performance and financial metrics of renewable energy systems. Project developers, policy makers, equipment manufacturers, and researchers use graphs and tables of SAM results in the process of evaluating financial, technology, and incentive options for renewable energy projects. SAM simulates the performance of photovoltaic, concentrating solar power, solar water heating, wind, geothermal, biomass, and conventional power systems. The financial model can represent financial structures for projects that either buy and sell electricity at retail rates (residential and commercial) or sell electricity at a price determined in a power purchase agreement (utility). SAM's advanced simulation options facilitate parametric and sensitivity analyses, and statistical analysis capabilities are available for Monte Carlo simulation and weather variability (P50/P90) studies. SAM can also read input variables from Microsoft Excel worksheets. For software developers, the SAM software development kit (SDK) makes it possible to use SAM simulation modules in their applications written in C/C++, C#, Java, Python, and MATLAB. NREL provides both SAM and the SDK as free downloads at http://sam.nrel.gov. Technical support and more information about the software are available on the website.
System Advisor Model, SAM 2011.12.2: General Description
Gilman, P.; Dobos, A.
2012-02-01T23:59:59.000Z
This document describes the capabilities of the U.S. Department of Energy and National Renewable Energy Laboratory's System Advisor Model (SAM), Version 2011.12.2, released on December 2, 2011. SAM is software that models the cost and performance of renewable energy systems. Project developers, policy makers, equipment manufacturers, and researchers use graphs and tables of SAM results in the process of evaluating financial, technology, and incentive options for renewable energy projects. SAM simulates the performance of solar, wind, geothermal, biomass, and conventional power systems. The financial model can represent financing structures for projects that either buy and sell electricity at retail rates (residential and commercial) or sell electricity at a price determined in a power purchase agreement (utility). Advanced analysis options facilitate parametric, sensitivity, and statistical analyses, and allow for interfacing SAM with Microsoft Excel or with other computer programs. SAM is available as a free download at http://sam.nrel.gov. Technical support and more information about the software are available on the website.
Karl Svozil
2001-06-29T23:59:59.000Z
Three extensions and reinterpretations of nonclassical probabilities are reviewed. (i) We propose to generalize the probability axiom of quantum mechanics to self-adjoint positive operators of trace one. Furthermore, we discuss the Cartesian and polar decomposition of arbitrary normal operators and the possibility to operationalize the corresponding observables. Thereby we review and emphasize the use of observables which maximally represent the context. (ii) In the second part, we discuss Pitowsky polytopes for automaton logic as well as for generalized urn models and evaluate methods to find the resulting Boole-Bell type (in)equalities. (iii) Finally, so-called ``parameter cheats'' are introduced, whereby parameters are transformed bijectively and nonlinearly in such a way that classical systems mimic quantum correlations and vice versa. It is even possible to introduce parameter cheats which violate the Boole-Bell type inequalities stronger than quantum ones, thereby trespassing the Tsirelson limit. The price to be paid is nonuniformity.
Inference for Clustered Mixed Outcomes from a Multivariate Generalized Linear Mixed Model
Chen, Hsiang-Chun
2013-08-01T23:59:59.000Z
) and E(?i2t?) with their marginal expectations over X, ??1 = EX {E(?i1t)} and ??2 = EX {E(?i2t)}, which are shown in the previous subsections. In other words, the overall total-CC is ?total = KtotalN,1,2 (??1, ??2) KtotalD,1,2 (??1, ??2) . 3.2.4....2 Multivariate Generalized Linear Mixed Model . . . . . . . . . . . . . 6 2.3 Assessing Correlation in Generalized Linear Mixed Model . . . . . . . 8 2.4 Bayesian Method for the Generalized Linear Mixed Model . . . . . . 10 3. ASSESSING CORRELATION...
Generalized models as a universal approach to the analysis of nonlinear dynamical systems
Thilo Gross; Ulrike Feudel
2006-01-29T23:59:59.000Z
We present a universal approach to the investigation of the dynamics in generalized models. In these models the processes that are taken into account are not restricted to specific functional forms. Therefore a single generalized models can describe a class of systems which share a similar structure. Despite this generality, the proposed approach allows us to study the dynamical properties of generalized models efficiently in the framework of local bifurcation theory. The approach is based on a normalization procedure that is used to identify natural parameters of the system. The Jacobian in a steady state is then derived as a function of these parameters. The analytical computation of local bifurcations using computer algebra reveals conditions for the local asymptotic stability of steady states and provides certain insights on the global dynamics of the system. The proposed approach yields a close connection between modelling and nonlinear dynamics. We illustrate the investigation of generalized models by considering examples from three different disciplines of science: a socio-economic model of dynastic cycles in china, a model for a coupled laser system and a general ecological food web.
Blei, David M.
a linear transformation of co- variates through a possibly non-linear link function to generate a response of generalized linear models (DP-GLMs), a Bayesian nonparametric regression model that combines the advantages of gen- eralized linear models with the flexibility of nonpara- metric regression. A DP-GLM produces
THE BETA-JACOBI MATRIX MODEL, THE CS DECOMPOSITION, AND GENERALIZED SINGULAR
Sutton, Brian
THE BETA-JACOBI MATRIX MODEL, THE CS DECOMPOSITION, AND GENERALIZED SINGULAR VALUE PROBLEMS ALAN EDELMAN AND BRIAN D. SUTTON Abstract. We provide a solution to the -Jacobi matrix model problem posed the algorithm on a Haar-distributed random matrix to produce the -Jacobi matrix model. The Jacobi ensemble on Rn
Mohri, Mehryar
applications or for adaptation purposes, one often needs to construct a language model based on the out put has been incorporated in a general software library for language modeling, the GRM Library, information extraction, machine translation, or document classification. In all cases, a language model
Efficient Learning of Generalized Linear and Single Index Models with Isotonic Regression
Efficient Learning of Generalized Linear and Single Index Models with Isotonic Regression Sham M) provide powerful generalizations of linear regression, where the target variable is assumed to be a (possibly unknown) 1-dimensional function of a linear predictor. In gen- eral, these problems entail non
Recurrence and non-ergodicity in generalized wind-tree models
Krzysztof Fr?czek; Pascal Hubert
2015-06-19T23:59:59.000Z
In this paper, we consider generalized wind-tree models and $\\Z^d$-covers over compact translation surfaces. Under suitable hypothesis, we prove recurrence of the linear flow in a generic direction and non-ergodicity of Lebesgue measure.
Constraining uncertainties in climate models using climate change detection techniques
Forest, Chris Eliot.; Allen, Myles R.; Stone, Peter H.; Sokolov, Andrei P.
Different atmosphere-ocean general circulation models produce significantly different projections of climate change in response to increases in greenhouse gases and aerosol concentrations in the atmosphere. The main reasons ...
AcceptedArticleThe effect of moist convection on thermally induced mesoscale circulations
Gentine, Pierre
AcceptedArticleThe effect of moist convection on thermally induced mesoscale circulations Malte of thermally induced mesoscale circulations rests primarily on observations and model studies of dry convection-eddy simulations are used to investigate the effect of moist convection on an idealized mesoscale circulation
The biogeochemistry and residual mean circulation of the southern ocean
Ito, Takamitsu, 1976-
2005-01-01T23:59:59.000Z
I develop conceptual models of the biogeochemistry and physical circulation of the Southern Ocean in order to study the air-sea fluxes of trace gases and biological productivity and their potential changes over ...
General Behavioral Thermal Modeling and Characterization for Multi-core Microprocessor Design
Tan, Sheldon X.-D.
General Behavioral Thermal Modeling and Characterization for Multi-core Microprocessor Design Thom-performance multi-core microprocessor design. The new approach builds the thermal behavioral models from ability. Experimental results on a real quad-core microprocessor show that ThermSID is more accurate than
Computable General Equilibrium Models for the Analysis of Energy and Climate Policies
Wing, Ian Sue
(i) how a model may be cali- brated using the economic data in a social accounting matrix, (ii) how of their size or apparent complexity), the 2 #12;key features of their data base and the calibration methodsComputable General Equilibrium Models for the Analysis of Energy and Climate Policies Ian Sue Wing
Thermohaline Circulation Lynne D Talley
Talley, Lynne D.
currents. The convective source regions and ocean basins are connected through deep western boundary cur of the upper 2000 m of the ocean are about 10 times faster, reaching 1 m s 1 in bound- ary currents and about 0, Ltd, Chichester, 2002 #12;Thermohaline Circulation Thermohaline circulation is the part of the ocean
Exclusive $B \\to PV $ Decays and CP Violation in the General two-Higgs-doublet Model
Y. L. Wu; C. Zhuang
2007-01-10T23:59:59.000Z
We calculate all the branching ratios and direct CP violations of $B \\to PV$ decays in a most general two-Higgs-doublet model with spontaneous CP violation. As the model has rich CP-violating sources, it is shown that the new physics effects to direct CP violations and branching ratios in some channels can be significant when adopting the generalized factorization approach to evaluate the hadronic matrix elements, which provides good signals for probing new physics beyond the SM in the future B experiments.
A General Nonlinear Fluid Model for Reacting Plasma-Neutral Mixtures
Meier, E T; Shumlak, U
2012-04-06T23:59:59.000Z
A generalized, computationally tractable fluid model for capturing the effects of neutral particles in plasmas is derived. The model derivation begins with Boltzmann equations for singly charged ions, electrons, and a single neutral species. Electron-impact ionization, radiative recombination, and resonant charge exchange reactions are included. Moments of the reaction collision terms are detailed. Moments of the Boltzmann equations for electron, ion, and neutral species are combined to yield a two-component plasma-neutral fluid model. Separate density, momentum, and energy equations, each including reaction transfer terms, are produced for the plasma and neutral equations. The required closures for the plasma-neutral model are discussed.
Davydov, E A
2013-01-01T23:59:59.000Z
Nowadays it is widely accepted that the evolution of the universe was driven by some scalar degrees of freedom both on its early stage and at present. The corresponding cosmological models often involve some scalar fields introduced ad hoc. In this paper we cultivate a different approach, which is based on a derivation of new scalar degrees of freedom from fundamental modifications of Einstein's gravity. In elaboration of our previous work, we here investigate properties of the dilaton-scalar gravity obtained by dimensional reductions of a recently proposed affine generalized gravity theory. We show that these models possess the same symmetries as related models of GR with ordinary scalar fields. As a result, for a rather general class of dilaton-scalar gravity models we construct additional first integrals and formulate an integral equation well suited for solving by iterations.
Phase synchronization of coupled bursting neurons and the generalized Kuramoto model
Fabiano A. S. Ferrari; Ricardo L. Viana; Sérgio R. Lopes; Ruedi Stoop
2015-02-13T23:59:59.000Z
Bursting neurons fire rapid sequences of action potential spikes followed by a quiescent period. The basic dynamical mechanism of bursting is the slow currents that modulate a fast spiking activity caused by rapid ionic currents. Minimal models of bursting neurons must include both effects. We considered one of these models and its relation with a generalized Kuramoto model, thanks to the definition of a geometrical phase for bursting and a corresponding frequency. We considered neuronal networks with different connection topologies and investigated the transition from a non-synchronized to a partially phase-synchronized state as the coupling strength is varied. The numerically determined critical coupling strength value for this transition to occur is compared with theoretical results valid for the generalized Kuramoto model.
Towards a Generalized Regression Model for On-body Energy Prediction from Treadmill Walking
Sukhatme, Gaurav S.
Towards a Generalized Regression Model for On-body Energy Prediction from Treadmill Walking sensor data to energy expenditure is the ques- tion of normalizating across physiological parameters. Common approaches such as weight scaling require validation for each new population. An alternative
Jia, Yan-Bin
IEEE TRANSACTIONS ON ROBOTICS, VOL. 26, NO. 5, OCTOBER 2010 837 Modeling Deformations of General Parametric Shells Grasped by a Robot Hand Jiang Tian and Yan-Bin Jia, Member, IEEE Abstract--The robot hand and normal of the contact area. Design and analysis of a manipulation strategy thus depend on reliable
Generalized Disjunctive Programming as a Systematic Modeling Framework to Derive Scheduling
Grossmann, Ignacio E.
variables and constraints, but it may compromise computational performance. On the other hand, the convex hull reformulation is tighter, which generally helps to speed up the search procedure. GDP formulations. The best performer is, however, a multiple time grid model which can be derived from the convex hull
Calibration of CDO Tranches with the Dynamical Generalized-Poisson Loss Model
Brigo, Damiano
Calibration of CDO Tranches with the Dynamical Generalized-Poisson Loss Model (updated shortened, and consistent calibration to quoted index CDO tranches and tranchelets for several maturities is feasible, as we dynamics, investigating calibration improve- ments and stability. JEL classification code: G13. AMS
Proton radioactivity within a generalized liquid drop model J. M. Dong,1
Paris-Sud XI, UniversitÃ© de
Proton radioactivity within a generalized liquid drop model J. M. Dong,1 H. F. Zhang,1 and G. Royer) The proton radioactivity half-lives of spherical proton emitters are investigated theoretically. The potential barriers preventing the emission of proton are determined in the quasimolecular shape path within
Tighter Relaxations for Higher-Order Models based on Generalized Roof Duality
Lunds Universitet
Tighter Relaxations for Higher-Order Models based on Generalized Roof Duality Johan Fredriksson one of the most successful approaches, namely roof duality, for approximately solving such problems cone. In the sec- ond method, it is shown that the roof dual bound can be applied in an iterated way
Well-posedness and generalized plane waves simulations of a 2D mode conversion model
Lise-Marie Imbert-Gérard
2015-04-27T23:59:59.000Z
Certain types of electro-magnetic waves propagating in a plasma can undergo a mode conversion process. In magnetic confinement fusion, this phenomenon is very useful to heat the plasma, since it permits to transfer the heat at or near the plasma center. This work focuses on a mathematical model of wave propagation around the mode conversion region, from both theoretical and numerical points of view. It aims at developing, for a well-posed equation, specific basis functions to study a wave mode conversion process. These basis functions, called generalized plane waves, are intrinsically based on variable coefficients. As such, they are particularly adapted to the mode conversion problem. The design of generalized plane waves for the proposed model is described in detail. Their implementation within a discontinuous Galerkin method then provides numerical simulations of the process. These first 2D simulations for this model agree with qualitative aspects studied in previous works.
Well-posedness and generalized plane waves simulations of a 2D mode conversion model
Imbert-Gérard, Lise-Marie
2015-01-01T23:59:59.000Z
Certain types of electro-magnetic waves propagating in a plasma can undergo a mode conversion process. In magnetic confinement fusion, this phenomenon is very useful to heat the plasma, since it permits to transfer the heat at or near the plasma center. This work focuses on a mathematical model of wave propagation around the mode conversion region, from both theoretical and numerical points of view. It aims at developing, for a well-posed equation, specific basis functions to study a wave mode conversion process. These basis functions, called generalized plane waves, are intrinsically based on variable coefficients. As such, they are particularly adapted to the mode conversion problem. The design of generalized plane waves for the proposed model is described in detail. Their implementation within a discontinuous Galerkin method then provides numerical simulations of the process. These first 2D simulations for this model agree with qualitative aspects studied in previous works.
Examining the Generalized Waring Model for the Analysis of Traffic Crashes
Peng, Yichuan
2013-05-03T23:59:59.000Z
characterized by heavy long tail (Guo and Trivedi, 2002). Third, many empirical crash data exhibit more zero observations than would be allowed by a NB regression model, which causes the low mean issue of traffic crash datasets. It is often difficult.... This kind of model has been extensively used in many areas (e.g. Ramaswamy et al., 1994; Wang et al., 1998; Guo & Trivedi, 2002)and has been proposed and applied in the traffic safety context recently (Park & Lord, 2010). The general model structure of a...
Liou, K. N.
On the correlation between ice water content and ice crystal size and its application to radiative analysis involving ice water content (IWC) and mean effective ice crystal size (De) intended, K. N., Y. Gu, Q. Yue, and G. McFarguhar (2008), On the correlation between ice water content and ice
Horizontal well circulation tool
Not Available
1990-11-06T23:59:59.000Z
This patent describes an apparatus for securement onto one end of a continuous length of remedial tubing introducible into a subterranean well and concentrically insertable through production tubing previously positioned within the well. The well having a deviated configuration including an entry portion communicating with a curved portion extending downwardly in the well from the entry portion, and a generally linear end portion traversable with a production formation.
Subin, Z.M.
2013-01-01T23:59:59.000Z
land model. J. Adv. Model. Earth Sys. Lee, S. -Y. , Chiang,in CESM1. J. Adv. Mod. Earth Sys. , In Press. Thompson, D.Analyses in the Community Earth System Model 1 (CESM1) By
Subin, Z.M.
2013-01-01T23:59:59.000Z
in the Community Earth System Model 1 (CESM1) By ZACHARY M.into the Community Earth System Model 1 (CESM1) to study thearea. In the Community Earth System Model 1 (CESM1; http://
Agarwala, R. [National Institutes of Health, Bethesda, MD (United States); Batzoglou, S. [MIT, Cambridge, MA (United States); Dancik, V. [Univ. of Southern California, Los Angeles, CA (United States)] [and others
1997-06-01T23:59:59.000Z
We consider the problem of determining the three-dimensional folding of a protein given its one-dimensional amino acid sequence. We use the HP model for protein folding proposed by Dill, which models protein as a chain of amino acid residues that are either hydrophobic or polar, and hydrophobic interactions are the dominant initial driving force for the protein folding. Hart and Istrail gave approximation algorithms for folding proteins on the cubic lattice under HP model. In this paper, we examine the choice of a lattice by considering its algorithmic and geometric implications and argue that triangular lattice is a more reasonable choice. We present a set of folding rules for a triangular lattice and analyze the approximation ratio which they achieve. In addition, we introduce a generalization of the HP model to account for residues having different levels of hydrophobicity. After describing the biological foundation for this generalization, we show that in the new model we are able to achieve similar constant factor approximation guarantees on the triangular lattice as were achieved in the standard HP model. While the structures derived from our folding rules are probably still far from biological reality, we hope that having a set of folding rules with different properties will yield more interesting folds when combined.
Energy and agriculture in the Haitian economy: A computable general equilibrium model
Jones, D.W.; Wu, M.T.C.; Das, S.; Cohn, S.M.
1988-02-01T23:59:59.000Z
This report documents a computable general equilibrium (CGE) model of the economy of Haiti, emphasizing energy use in agriculture. CGE models compare favorably with econometric models for developing countries in terms of their ability to take advantage of available data. The model of Haiti contains ten production sectors: manufacturing, services, transportation, electricity, rice, coffee, sugar cane, sugar refining, general agriculture, and fuelwood and charcoal. All production functions use functional forms which permit factor substitution. Consumption is specified for three income categories of consumers and a government sector with a linear expenditure system (LES) of demand equations. The economy exports four categories of products and imports six. Balanced trade and capital accounts are required for equilibrium. Total sectoral allocations of land, labor and capital are constrained to equal the quantities of these inputs in the Haitian economy as of the early 1980s. The model can be used to study the consequences of fiscal and trade policies and sectorally oriented productivity improvement policies. Guidance is offered regarding how to use the model to study economic growth and technological change. Limitations of the mode are also pointed out as well as user strategies which can lessen or work around some of those limitations. 19 refs.
N. Itagaki; H. Matsuno; T. Suhara
2015-07-09T23:59:59.000Z
The antisymmetrized quasi-cluster model (AQCM) is a method to describe a transition from the alpha-cluster wave function to the jj-coupling shell model wave function. In this model, the cluster-shell transition is characterized by only two parameters; R representing the distance between alpha clusters and Lambda describing the breaking of alpha clusters, and the contribution of the spin-orbit interaction, very important in the jj-coupling shell model, can be taken into account starting with the alpha cluster model wave function. In this article we show the generality of AQCM by extending the application to heavier region; various 4N nuclei from 4He to 52Fe. We show and compare the energy curves for the alpha+40Ca cluster configuration calculated with and without alpha breaking effect in 44Ti.
Energy-Momentum of the Friedmann Models in General Relativity and Teleparallel Theory of Gravity
M. Sharif; M. Jamil Amir
2008-09-09T23:59:59.000Z
This paper is devoted to the evaluation of the energy-momentum density components for the Friedmann models. For this purpose, we have used M${\\o}$ller's pseudotensor prescription in General Relativity and a certain energy-momentum density developed from his teleparallel formulation. It is shown that the energy density of the closed Friedmann universe vanishes on the spherical shell at the radius $\\rho=2\\sqrt{3}$. This coincides with the earlier results available in the literature. We also discuss the energy of the flat and open models. A comparison shows a partial consistency between the M${\\o}$ller's pseudotensor for General Relativity and teleparallel theory. Further, it is shown that the results are independent of the free dimensionless coupling constant of the teleparallel gravity.
A General Hippocampal Computational Model Combining Episodic and Spatial Memory in a Spiking Model
Aguiar, Paulo de Castro
The hippocampus, in humans and rats, plays crucial roles in spatial tasks and nonspatial tasks involving episodic-type memory. This thesis presents a novel computational model of the hippocampus (CA1, CA3 and dentate ...
Nonlinear dynamics of system oscillations modeled by a forced Van der Pol generalized oscillator
L. A. Hinvi; C. H. Miwadinou; A. V. Monwanou; J. B. Chabi Orou
2014-02-18T23:59:59.000Z
This paper considers the oscillations modeled by a forced Van der Pol generalized oscillator. These oscillations are described by a nonlinear differential equation of the form $ \\ddot{x}+x-\\varepsilon\\left(1-ax^2-b\\dot{x}^2\\right)\\dot{x}=E\\sin{{\\Omega}t}.$ The amplitudes of the forced harmonic, primary resonance superharmonic and subharmonic oscillatory states are obtained using the harmonic balance technique and the multiple time scales methods. We obtain also the hysteresis and jump phenomena in the system oscillations. Bifurcation sequences displayed by the model for each type of oscillatory states are performed numerically through the fourth-order Runge- Kutta scheme.
Fourier analysis for generalized cylinders with polar models of cross-sections
Forsythe, William Clarence
1990-01-01T23:59:59.000Z
. Background 1. 2. Modeling Criteria 1. 3. Modeling Methods 1. 3. 1. Voxel Methods 1. 3. 2. Constructive Solid Geometry 1. 3. 3. Boundary Representation 1. 3. 4. Superquadrics 1. 4. Generalized Cylinder 1. 4. 1. GC Definition 1. 4. 2. GC Research 1. 4. 3. GC... such as spheres, cuboids, and tetrahedrons. This method works well with man-made objects. For instance, a table may be represented with five cuboids, using one cuboid for the top of the table, and one cuboid each, positioned appropriately, for the four legs...
Minimum Description Length Model Selection Criteria for Generalized Linear Models Mark Hansen
Yu, Bin
of simulations for logistic regression illustrate that mixture MDL can ``bridge'' AIC and BIC in the sense. By viewing statistical modeling as a means of generating descriptions of observed data, the MDL framework (cf for a probability distribution Q on A. An integervalued function L corresponds to the code length of a binary
Zhong, L.
2014-01-01T23:59:59.000Z
FLOW RATE, SMALL TEMPERATURE DIFFERENCE” BASED ON VERIFIED DYNAMIC MODEL SIMULATIONS OF A HOT WATER DISTRICT HEATING SYSTEM Li Lian Zhong, Senior Sales Consultant, Danfoss Automatic Controls Management (Shanghai) Co.,Ltd, Anshan, China ABSTRACT... Dynamic models of an indirect hot water district heating system were developed based on the first principle of thermodynamics. The ideal model was verified by using measured operational data. The ideal and verified models were applied to obtain...
Research papers The vertical structure of time-mean estuarine circulation in a shallow,
Polton, Jeff
the mean fluid depth the residual circulation is well modelled by a water column of uniform density 2013 Accepted 5 March 2013 Available online 27 March 2013 Keywords: Tidal residual ROFI HF radar ADCP) model shows that the time-mean depth weighted flow, or the residual circulation, is usefully constrained
Polvani, Lorenzo M.
[1] The effect of ozone depletion on temperature trends in the tropical lower stratosphere is explored with an atmospheric general circulation model, and directly contrasted to the effect of increased greenhouse gases and ...
Generalized Uncertainty Relations and Long Time Limits for Quantum Brownian Motion Models
C. Anastopoulos; J. J. Halliwell
1994-07-27T23:59:59.000Z
We study the time evolution of the reduced Wigner function for a class of quantum Brownian motion models. We derive two generalized uncertainty relations. The first consists of a sharp lower bound on the uncertainty function, $U = (\\Delta p)^2 (\\Delta q)^2 $, after evolution for time $t$ in the presence of an environment. The second, a stronger and simpler result, consists of a lower bound at time $t$ on a modified uncertainty function, essentially the area enclosed by the $1-\\sigma$ contour of the Wigner function. In both cases the minimizing initial state is a non-minimal Gaussian pure state. These generalized uncertainty relations supply a measure of the comparative size of quantum and thermal fluctuations. We prove two simple inequalites, relating uncertainty to von Neumann entropy, and the von Neumann entropy to linear entropy. We also prove some results on the long-time limit of the Wigner function for arbitrary initial states. For the harmonic oscillator the Wigner function for all initial states becomes a Gaussian at large times (often, but not always, a thermal state). We derive the explicit forms of the long-time limit for the free particle (which does not in general go to a Gaussian), and also for more general potentials in the approximation of high temperature.
Ocean Circulation Lynne D Talley
Talley, Lynne D.
to the topography, with low pressure in the center. Ocean currents transport heat from the tropics to the poles have gone to sea. As knowledge about ocean currents and capabilities to observe it below the surfaceOcean Circulation Lynne D Talley Volume 1, The Earth system: physical and chemical dimensions
Circulation in gas-slurry column reactors
Clark, N.; Kuhlman, J.; Celik, I.; Gross, R.; Nebiolo, E.; Wang, Yi-Zun.
1990-08-15T23:59:59.000Z
Circulation in bubble columns, such as those used in fischer-tropsch synthesis, detracts from their performance in that gas is carried on average more rapidly through the column, and the residence time distribution of the gas in the column is widened. Both of these factors influence mass-transfer operations in bubble columns. Circulation prediction and measurement has been undertaken using probes, one-dimensional models, laser Doppler velocimetry, and numerical modeling. Local void fraction was measured using resistance probes and a newly developed approach to determining air/water threshold voltage for the probe. A tall column of eight inch diameter was constructed of Plexiglas and the distributor plate was manufactured to distribute air evenly through the base of the column. Data were gathered throughout the volume at three different gas throughputs. Bubble velocities proved difficult to measure using twin probes with cross-correlation because of radial bubble movement. A series of three-dimensional mean and RMS bubble and liquid velocity measurements were also obtained for a turbulent flow in a laboratory model of a bubble column. These measurements have been made using a three-component laser Doppler velocimeter (LDV), to determine velocity distributions non-intrusively. Finally, the gas-liquid flow inside a vertically situated circular isothermal column reactor was simulated numerically. 74 refs., 170 figs., 5 tabs.
General model selection estimation of a periodic regression with a Gaussian noise
Konev, Victor; 10.1007/s10463-008-0193-1
2010-01-01T23:59:59.000Z
This paper considers the problem of estimating a periodic function in a continuous time regression model with an additive stationary gaussian noise having unknown correlation function. A general model selection procedure on the basis of arbitrary projective estimates, which does not need the knowledge of the noise correlation function, is proposed. A non-asymptotic upper bound for quadratic risk (oracle inequality) has been derived under mild conditions on the noise. For the Ornstein-Uhlenbeck noise the risk upper bound is shown to be uniform in the nuisance parameter. In the case of gaussian white noise the constructed procedure has some advantages as compared with the procedure based on the least squares estimates (LSE). The asymptotic minimaxity of the estimates has been proved. The proposed model selection scheme is extended also to the estimation problem based on the discrete data applicably to the situation when high frequency sampling can not be provided.
On the Patterns of Wind-Power Input to the Ocean Circulation
Roquet, Fabien
Pathways of wind-power input into the ocean general circulation are analyzed using Ekman theory. Direct rates of wind work can be calculated through the wind stress acting on the surface geostrophic flow. However, because ...
Continuous Circulation System: a new enabling technology
Kenawy, Walid F.
2002-01-01T23:59:59.000Z
are caused by the interruption of the drilling-fluid circulation. This interruption normally occurs when making drillpipe connections. Interruption of circulation causes wellbore problems like ballooning of the well, gelation of drilling mud, and settling...
Modeling Climate and Production-related Impacts on Ice-core Beryllium-10
Modeling Climate and Production-related Impacts on Ice-core Beryllium-10 Christy Veeder Submitted Modeling Climate and Production-related Impacts on Ice-core Beryllium-10 Christy Veeder I use the Goddard Institute for Space Studies ModelE general circulation model to ex- amine the how beryllium-10, a cosmogenic
Stability of Thermohaline circulation with respect to fresh water release
Ajay Patwardhan; Vivek Tewary
2008-05-16T23:59:59.000Z
The relatively warm climate found in the North- Western Europe is due to the gulf stream that circulates warm saline water from southern latitudes to Europe. In North Atlantic ocean the stream gives out a large amount of heat, cools down and sinks to the bottom to complete the Thermohaline circulation. There is considerable debate on the stability of the stream to inputs of fresh water from the melting ice in Greenland and Arctic. The circulation, being switched off, will have massive impact on the climate of Europe. Intergovernmental panel on climate change (IPCC) has warned of this danger in its recent report. Our aim is to model the Thermohaline circulation at the point where it sinks in the North-Atlantic. We create a two dimensional discrete map modeling the salinity gradient and vertical velocity of the stream. We look for how a perturbation in the form of fresh water release can destabilise the circulation by pushing the velocity below a certain threshold.
Lee, Shiu-Hang; Nagataki, Shigehiro
2012-01-01T23:59:59.000Z
To better model the efficient production of cosmic rays (CRs) in supernova remnants (SNRs) with the associated coupling between CR production and SNR dynamics, we have generalized an existing cr-hydro-NEI code (i.e., Ellison et al. 2012) to include the following processes: (1) an explicit calculation of the upstream precursor structure including the position dependent flow speed, density, temperature, and magnetic field strength; (2) a momentum and space dependent CR diffusion coefficient; (3) an explicit calculation of magnetic field amplification (MFA); (4) calculation of the maximum CR momentum using the amplified magnetic field; (5) a finite Alfven speed for the particle scattering centers; and (6) the ability to accelerate a superthermal seed population of CRs as well as the ambient thermal plasma. While a great deal of work has been done modeling SNRs, most work has concentrated on either the continuum emission from relativistic electrons or ions, or the thermal emission from the shock heated plasma. Ou...
Ozgur Akarsu; Tekin Dereli; Nihan Katirci; Mikhail B. Sheftel
2015-05-04T23:59:59.000Z
In a recent study Akarsu and Dereli (Gen. Relativ. Gravit. 45:1211, 2013) discussed the dynamical reduction of a higher dimensional cosmological model which is augmented by a kinematical constraint characterized by a single real parameter, correlating and controlling the expansion of both the external (physical) and internal spaces. In that paper explicit solutions were found only for the case of three dimensional internal space ($n=3$). Here we derive a general solution of the system using Lie group symmetry properties, in parametric form for arbitrary number $n=1,2,3,\\dots$ of internal dimensions. We also investigate the dynamical reduction of the model as a function of cosmic time $t$ for various values of $n$ and generate parametric plots to discuss cosmologically relevant results.
Quantum Analogical Modeling: A General Quantum Computing Algorithm for Predicting Language Behavior
Royal Skousen
2005-10-18T23:59:59.000Z
This paper proposes a general quantum algorithm that can be applied to any classical computer program. Each computational step is written using reversible operators, but the operators remain classical in that the qubits take on values of only zero and one. This classical restriction on the quantum states allows the copying of qubits, a necessary requirement for doing general classical computation. Parallel processing of the quantum algorithm proceeds because of the superpositioning of qubits, the only aspect of the algorithm that is strictly quantum mechanical. Measurement of the system collapses the superposition, leaving only one state that can be observed. In most instances, the loss of information as a result of measurement would be unacceptable. But the linguistically motivated theory of Analogical Modeling (AM) proposes that the probabilistic nature of language behavior can be accurately modeled in terms of the simultaneous analysis of all possible contexts (referred to as supracontexts) providing one selects a single supracontext from those supracontexts that are homogeneous in behavior (namely, supracontexts that allow no increase in uncertainty). The amplitude for each homogeneous supracontext is proportional to its frequency of occurrence, with the result that the probability of selecting one particular supracontext to predict the behavior of the system is proportional to the square of its frequency.
Degeneracies and scaling relations in general power-law models for gravitational lenses
Olaf Wucknitz
2002-02-20T23:59:59.000Z
The time delay in gravitational lenses can be used to derive the Hubble constant in a relatively simple way. The results of this method are less dependent on astrophysical assumptions than in many other methods. The most important uncertainty is related to the mass model used. We discuss a family of models with a separable radial power-law and an arbitrary angular dependence for the potential psi = r^beta * F(theta). Isothermal potentials are a special case of these models with beta=1. An additional external shear is used to take into account perturbations from other galaxies. Using a simple linear formalism for quadruple lenses, we can derive H0 as a function of the observables and the shear. If the latter is fixed, the result depends on the assumed power-law exponent according to H0 proportional to (2-beta)/beta. The effect of external shear is quantified by introducing a `critical shear' gamma_c as a measure for the amount of shear that changes the result significantly. The analysis shows, that in the general case H0 and gamma_c do not depend on the position of the lens galaxy. We discuss these results and compare with numerical models for a number of real lens systems.
Dynamics of the stratospheric circulation response to climate change
Dynamics of the stratospheric circulation response to climate change Michael Sigmond, University the world have employed chemistry climate models (CCMs) to predict the future stratospheric dynamical (Eyring et al., 2005). Despite the abundance of simula- tions, however, many dynamical issues remain
Validation of SSC using the FFTF natural-circulation tests
Horak, W.C.; Guppy, J.G.; Kennett, R.J.
1982-01-01T23:59:59.000Z
As part of the Super System Code (SSC) validation program, the 100% power FFTF natural circulation test has been simulated using SSC. A detailed 19 channel, 2 loop model was used in SSC. Comparisons showed SSC calculations to be in good agreement with the Fast Flux Test Facility (FFTF), test data. Simulation of the test was obtained in real time.
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirt DocumentationSitesWeather6 Shares of U.S.CareerPASTChemistry andPhysics Lab Chuck Kessel Wins
A general approach to statistical modeling of physical laws: nonparametric regression
I. Grabec
2007-04-01T23:59:59.000Z
Statistical modeling of experimental physical laws is based on the probability density function of measured variables. It is expressed by experimental data via a kernel estimator. The kernel is determined objectively by the scattering of data during calibration of experimental setup. A physical law, which relates measured variables, is optimally extracted from experimental data by the conditional average estimator. It is derived directly from the kernel estimator and corresponds to a general nonparametric regression. The proposed method is demonstrated by the modeling of a return map of noisy chaotic data. In this example, the nonparametric regression is used to predict a future value of chaotic time series from the present one. The mean predictor error is used in the definition of predictor quality, while the redundancy is expressed by the mean square distance between data points. Both statistics are used in a new definition of predictor cost function. From the minimum of the predictor cost function, a proper number of data in the model is estimated.
Wakamatsu, M.; Tsujimoto, H. [Department of Physics, Faculty of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)
2005-04-01T23:59:59.000Z
The theoretical predictions are given for the forward limit of the unpolarized spin-flip isovector generalized parton distribution function (E{sup u}-E{sup d})(x,{xi},t) within the framework of the chiral quark soliton model, with full inclusion of the polarization of Dirac sea quarks. We observe that [(H{sup u}-H{sup d})+(E{sup u}-E{sup d})](x,0,0) has a sharp peak around x=0, which we interpret as a signal of the importance of the pionic qq excitation with large spatial extension in the transverse direction. Another interesting indication given by the predicted distribution in combination with Ji's angular momentum sum rule is that the d quark carries more angular momentum than the u quark in the proton, which may have some relation with the physics of the violation of the Gottfried sum rule.
Hartle's model within the general theory of perturbative matchings: the change in mass
Borja Reina; Raül Vera
2014-12-22T23:59:59.000Z
Hartle's model provides the most widely used analytic framework to describe isolated compact bodies rotating slowly in equilibrium up to second order in perturbations in the context of General Relativity. Apart from some explicit assumptions, there are some implicit, like the "continuity" of the functions in the perturbed metric across the surface of the body. In this work we sketch the basics for the analysis of the second order problem using the modern theory of perturbed matchings. In particular, the result we present is that when the energy density of the fluid in the static configuration does not vanish at the boundary, one of the functions of the second order perturbation in the setting of the original work by Hartle is not continuous. This discrepancy affects the calculation of the change in mass of the rotating star with respect to the static configuration needed to keep the central energy density unchanged.
Yock, Adam D., E-mail: ADYock@mdanderson.org; Kudchadker, Rajat J. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States)] [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States); Rao, Arvind [Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and the Graduate School of Biomedical Sciences, the University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States)] [Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and the Graduate School of Biomedical Sciences, the University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States); Dong, Lei [Scripps Proton Therapy Center, San Diego, California 92121 and The Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States)] [Scripps Proton Therapy Center, San Diego, California 92121 and The Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States); Beadle, Beth M.; Garden, Adam S. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)] [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Court, Laurence E. [Department of Radiation Physics and Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States)] [Department of Radiation Physics and Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas 77030 (United States)
2014-05-15T23:59:59.000Z
Purpose: The purpose of this work was to develop and evaluate the accuracy of several predictive models of variation in tumor volume throughout the course of radiation therapy. Methods: Nineteen patients with oropharyngeal cancers were imaged daily with CT-on-rails for image-guided alignment per an institutional protocol. The daily volumes of 35 tumors in these 19 patients were determined and used to generate (1) a linear model in which tumor volume changed at a constant rate, (2) a general linear model that utilized the power fit relationship between the daily and initial tumor volumes, and (3) a functional general linear model that identified and exploited the primary modes of variation between time series describing the changing tumor volumes. Primary and nodal tumor volumes were examined separately. The accuracy of these models in predicting daily tumor volumes were compared with those of static and linear reference models using leave-one-out cross-validation. Results: In predicting the daily volume of primary tumors, the general linear model and the functional general linear model were more accurate than the static reference model by 9.9% (range: ?11.6%–23.8%) and 14.6% (range: ?7.3%–27.5%), respectively, and were more accurate than the linear reference model by 14.2% (range: ?6.8%–40.3%) and 13.1% (range: ?1.5%–52.5%), respectively. In predicting the daily volume of nodal tumors, only the 14.4% (range: ?11.1%–20.5%) improvement in accuracy of the functional general linear model compared to the static reference model was statistically significant. Conclusions: A general linear model and a functional general linear model trained on data from a small population of patients can predict the primary tumor volume throughout the course of radiation therapy with greater accuracy than standard reference models. These more accurate models may increase the prognostic value of information about the tumor garnered from pretreatment computed tomography images and facilitate improved treatment management.
Crauel, Hans
A General Asset-Liability Management Model for the Efficient Simulation of Portfolios of Life and a stronger competition have increased the importance of stochastic asset-liability management (ALM) models development of life insurance products. Keywords: asset-liability management, participating policies
L General Permit Parking LOT A General Permit Parking LOT C General Permit Parking LOT R Reserved Parking LOT D Faculty/Staff Parking LOT K General Permit Parking LOT J Reserved Parking PV LOT General Parking after 3 p.m. WEST CAMPUS PARKING LOT O General Permit Parking LOT M General Permit Parking LOT P
98 28 28 60 96 31 7 23 LOT L General Permit Parking LOT A General Permit Parking LOT C General Permit Parking LOT R Reserved Parking LOT D Faculty/Staff Parking LOT K General Permit Parking LOT J Reserved Parking PV LOT General Parking after 3 p.m. WEST CAMPUS PARKING LOT O General Permit Parking LOT M General
Scott, Jeffery R.
The response of the ocean’s meridional overturning circulation (MOC) to increased greenhouse gas forcing is examined using a coupled model of intermediate complexity, including a dynamic 3D ocean subcomponent. Parameters ...
Bolshov, L.; Kondratenko, P.; Matveev, L.; Pruess, K.
2008-09-01T23:59:59.000Z
In this study, new elements were developed to generalize the dual-porosity model for moisture infiltration on and solute transport in unsaturated rocks, taking into account fractal aspects of the percolation process. Random advection was considered as a basic mechanism of solute transport in self-similar fracture systems. In addition to spatial variations in the infiltration velocity field, temporal fluctuations were also taken into account. The rock matrix, a low-permeability component of the heterogeneous geologic medium, acts as a trap for solute particles and moisture. Scaling relations were derived for the moisture infiltration flux, the velocity correlation length, the average velocity of infiltration, and the velocity correlation function. The effect of temporal variations in precipitation intensity on the infiltration processes was analyzed. It showed that the mode of solute transport is determined by the power exponent in the advection velocity correlation function and the dimensionality of the trapping system, both of which may change with time. Therefore, depending on time, various transport regimes may be realized: superdiffusion, subdiffusion, or classical diffusion. The complex structure of breakthrough curves from changes in the transport regimes was also examined. A renormalization of the solute source strength due to characteristic fluctuations of highly disordered media was established.
Microfluidic Platforms for Capturing Circulating Tumor Cells
Tang, William C
Microfluidic Platforms for Capturing Circulating Tumor Cells Sweta Gupta, Allison C. Baker-cost microfluidic device that can be used to isolate and capture circulating tumor cells (CTCs) from whole blood. The device was made from polydimethylsiloxane (PDMS) consisting of a microfluidic channel with microposts
Downhole material injector for lost circulation control
Glowka, D.A.
1994-09-06T23:59:59.000Z
Apparatus and method are disclosed for simultaneously and separately emplacing two streams of different materials through a drill string in a borehole to a downhole location for lost circulation control. The two streams are mixed outside the drill string at the desired downhole location and harden only after mixing for control of a lost circulation zone. 6 figs.
Downhole material injector for lost circulation control
Glowka, D.A.
1991-01-01T23:59:59.000Z
This invention is comprised of an apparatus and method for simultaneously and separately emplacing two streams of different materials through a drillstring in a borehole to a downhole location for lost circulation control. The two streams are mixed outside the drillstring at the desired downhole location and harden only after mixing for control of a lost circulation zone.
PHYSICS OF OCEAN CIRCULATION Instructor: S. Riser
Riser, Stephen C.
Ocean using Argo float data from 2006 June December #12;Surface Currents of the Indian Ocean - Monsoons and surface ocean currents do not exactly coincide (why?). N. Atlantic Schematic gyres #12;Surface circulationOCEAN 510 PHYSICS OF OCEAN CIRCULATION ·Instructor: S. Riser ·Whom this course is for: Everyone
Wave Energy Converter (WEC) Array Effects on Wave Current and Sediment Circulation: Monterey Bay CA.
Roberts, Jesse D.; Jones, Craig; Magalen, Jason
2014-09-01T23:59:59.000Z
The goal s of this study were to develop tools to quantitatively characterize environments where wave energy converter ( WEC ) devices may be installed and to assess e ffects on hydrodynamics and lo cal sediment transport. A large hypothetical WEC array was investigated using wave, hydrodynamic, and sediment transport models and site - specific average and storm conditions as input. The results indicated that there were significant changes in sediment s izes adjacent to and in the lee of the WEC array due to reduced wave energy. The circulation in the lee of the array was also altered; more intense onshore currents were generated in the lee of the WECs . In general, the storm case and the average case show ed the same qualitative patterns suggesting that these trends would be maintained throughout the year. The framework developed here can be used to design more efficient arrays while minimizing impacts on nearshore environmen ts.
Janson, Svante
Analyzing generalized Stirling permutations via relations to families of increasing trees and urn-mail: kuba@geometrie.tuwien.ac.at, Alois.Panholzer@tuwien.ac.at) Abstract. Stirling permutations are a class of multipermutations introduced by Gessel and Stanley. We consider Stirling permutations and generalizations
Wisconsin at Madison, University of
Multivariate General Linear Models (MGLM) on Riemannian Manifolds with Applications to Statistical range of such methods by deriv- ing schemes for multivariate multiple linear regression -- a manifold ] , ^ = ¯y - ^¯x. (2) If x and y are multivariates, one can easily replace the mul- tiplication and division
Jayaram, Bhyravabotla
Solvation Free Energy of Biomacromolecules: Parameters for a Modified Generalized Born Model provides rapid estimates of the electrostatic free energies of solvation for diverse molecules of parameters compatible with the AMBER force field is described. The method is used to estimate free energies
RF power recovery feedback circulator
Sharamentov, Sergey I. (Bolingbrook, IL)
2011-03-29T23:59:59.000Z
A device and method for improving the efficiency of RF systems having a Reflective Load. In the preferred embodiment, Reflected Energy from a superconducting resonator of a particle accelerator is reintroduced to the resonator after the phase of the Reflected Energy is aligned with the phase of the Supply Energy from a RF Energy Source. In one embodiment, a Circulator is used to transfer Reflected Energy from the Reflective Load into a Phase Adjuster which aligns the phase of the Reflected Energy with that of the Supply Energy. The phase-aligned energy is then combined with the Supply Energy, and reintroduced into the Reflective Load. In systems having a constant phase shift, the Phase Adjuster may be designed to shift the phase of the Reflected Energy by a constant amount using a Phase Shifter. In systems having a variety (variable) phase shifts, a Phase Shifter controlled by a phase feedback loop comprising a Phase Detector and a Feedback Controller to account for the various phase shifts is preferable.
CIRCULATING MOVING BED COMBUSTION PROOF OF CONCEPT
Jukkola, Glen
2010-06-30T23:59:59.000Z
Circulating Moving Bed (CMB) combustion technology has its roots in traditional circulating fluidized bed technology and involves a novel method of solid fuel combustion and heat transfer. CMB technology represents a step change in improved performance and cost relative to conventional PC and FBC boilers. The CMB heat exchanger preheats the energy cycle working fluid, steam or air, to the high temperature levels required in systems for advanced power generation. Unique features of the CMB are the reduction of the heat transfer surfaces by about 60% as a result of the enhanced heat transfer rates, flexibility of operation, and about 30% lower cost over existing technology. The CMB Phase I project ran from July 2001 through March 2003. Its objective was to continue development of the CMB technology with a series of proof of concept tests. The tests were conducted at a scale that provided design data for scale up to a demonstration plant. These objectives were met by conducting a series of experiments in ALSTOM Power’s Multi-use Test Facility (MTF). The MTF was modified to operate under CMB conditions of commercial interest. The objective of the tests were to evaluate gas-to-solids heat transfer in the upper furnace, assess agglomeration in the high temperature CMB bubbling bed, and evaluate solids-to-tube heat transfer in the moving bed heat exchanger. The Phase I program results showed that there are still some significant technical uncertainties that needed to be resolved before the technology can be confidently scaled up for a successful demonstration plant design. Work remained in three primary areas: • scale up of gas to solid heat transfer • high temperature finned surface design • the overall requirements of mechanical and process design. The CMB Phase II workscope built upon the results of Phase I and specifically addressed the remaining technical uncertainties. It included a scaled MTF heat transfer test to provide the necessary data to scale up gas-to-solids heat transfer. A stress test rig was built and tested to provide validation data for a stress model needed to support high temperature finned surface design. Additional cold flow model tests and MTF tests were conducted to address mechanical and process design issues. This information was then used to design and cost a commercial CMB design concept. Finally, the MBHE was reconfigured into a slice arrangement and tested for an extended duration at a commercial CFB plant.
Trampedach, Regner; Collet, Remo; Nordlund, Åke; Stein, Robert F
2013-01-01T23:59:59.000Z
Present grids of stellar atmosphere models are the workhorses in interpreting stellar observations, and determining their fundamental parameters. These models rely on greatly simplified models of convection, however, lending less predictive power to such models of late type stars. We present a grid of improved and more reliable stellar atmosphere models of late type stars, based on deep, 3D, convective, stellar atmosphere simulations. This grid is to be used in general for interpreting observations, and improve stellar and asteroseismic modeling. We solve the Navier Stokes equations in 3D and concurrent with the radiative transfer equation, for a range of atmospheric parameters, covering most of stellar evolution with convection at the surface. We emphasize use of the best available atomic physics for quantitative predictions and comparisons with observations. We present granulation size, convective expansion of the acoustic cavity, asymptotic adiabat, as function of atmospheric parameters. These and other re...
Thermodynamical description of modified generalized Chaplygin gas model of dark energy
H. Ebadi; H. Moradpour
2015-04-15T23:59:59.000Z
We consider a universe filled by a modified generalized Chaplygin gas together with a pressureless dark matter component. We get a thermodynamical interpretation for the modified generalized Chaplygin gas confined to the apparent horizon of FRW universe, whiles dark sectors do not interact with each other. Thereinafter, by taking into account a mutual interaction between the dark sectors of the cosmos, we find a thermodynamical interpretation for interacting modified generalized Chaplygin gas. Additionally, probable relation between the thermal fluctuations of the system and the assumed mutual interaction is investigated. Finally, we show that if one wants to solve the coincidence problem by using this mutual interaction, then the coupling constants of the interaction will be constrained. The corresponding constraint is also addressed. Moreover, the thermodynamic interpretation of using either a generalized Chaplygin gas or a Chaplygin gas to describe dark energy is also addressed throughout the paper.
A General Model of Concurrency and its Implementation as Many-core Dynamic RISC
Jesshope, Chris
scaling, good energy efficiency and tolerance to large latencies in asynchronous operations. This is true. This paper describes general-purpose solutions and builds on the premise that what is missing is a coherent
Dynamic Switching of the Spin Circulation in Tapered Magnetic...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Dynamic Switching of the Spin Circulation in Tapered Magnetic Nanodisks Dynamic Switching of the Spin Circulation in Tapered Magnetic Nanodisks Print Monday, 22 April 2013 12:09...
Menke, William
trivially. 4. The damped least squares generalized inverse has the form Note that since is symmetric, its least squares generalized inverse % GMG = (G'*G + epsi*eye(M,M)) \\ G' epsi = 0.1; A = (G'*G + epsi data kernel s=0.1; G=random('Normal',0, s, N, M ) + eye(N,M); % stddev of data sigmad = 1; % use damped
Plant Heterogeneity and Applied General Equilibrium Models of Trade: Lessons from
Stoiciu, Mihai
sector. I introduce these features by adapting a Hopenhayn (1992) model of plant entry and exit and embed a Hopenhayn (1992) model of firm entry and exit and embed this in a static multisector trade model with monop) develops a model with plant dynamics to match entry and exit rates in US manufacturing. I do
Improved Indoor Tracking Based on Generalized t-Distribution Noise Model
Shuo, Liu; Le, Yin; Khuen, Ho Weng; Voon, Ling Keck
2015-01-01T23:59:59.000Z
objective function. Industrial & engineering chemistryfunction approac. Industrial & Engineering Chem- istrynoise model. Industrial & Engineering Chemistry Research,
focus. There, several external sources of circulation have been identified (wind, deep convection using a layered, hydrostatic ocean model. The specific experiments planned are (i), the concentration, also optically. The fourth set of experiments requires special comment. Numerical modeling
Sillman, Sanford
Effects of cloud overlap in photochemical models Yan Feng, Joyce E. Penner, Sanford Sillman for radiation and cloud microphysics in general circulation models and for photolysis in photochemical transport their effects on averaged photolysis frequencies and OH concentrations in a global photochemical model
Circulating Fluidized Bed Combustion Boiler Project
Farbstein, S. B.; Moreland, T.
1984-01-01T23:59:59.000Z
The project to build a PYROFLOW circulating fluidized bed combustion (FBC) boiler at the BFGoodrich Chemical Plant at Henry, Illinois, is described. This project is being partially funded by Illinois to demonstrate the feasibility of utilizing high...
Circulation and convection in the Irminger Sea
Våge, Kjetil
2010-01-01T23:59:59.000Z
Aspects of the circulation and convection in the Irminger Sea are investigated using a variety of in-situ, satellite, and atmospheric reanalysis products. Westerly Greenland tip jet events are intense, small-scale wind ...
Testing Lack-of-Fit of Generalized Linear Models via Laplace Approximation
Glab, Daniel Laurence
2012-07-16T23:59:59.000Z
In this study we develop a new method for testing the null hypothesis that the predictor function in a canonical link regression model has a prescribed linear form. The class of models, which we will refer to as canonical ...
Wolberg, George
evaluation. 10.More complex modeling: EnergyPlus. EnergyPlus interface tools. 11.Linking energy models to other tools, BIM. EnergyPlus, setting up from Revit or Sketch-up. 12.Daylighting. RADIANCE demo. Project
Ghan, S.J.; MacCracken, M.C.; Walton, J.J.
1985-08-01T23:59:59.000Z
An atmospheric general circulation model (AGCM) has been initialized with a 150 Tg summertime injection of smoke from post-war fires over Europe, Asia and North America. The smoke is subject to large-scale and convectice transport, dry deposition, coagulation and precipitation scavenging. The Hadley circulation is shown to respond in three stages. In the first stage, which lasts about one week depending on initial conditions, the Hadley circulation doubles in intensity. As the smoke spreads across the equator, and as the troposphere becomes more stable, the Hadley cell then weakens until it becomes actually weaker than in the control climate. In the final stage, as the smoke is removed, the Hadley cell gradually returns towards the control. Surface precipitation generally decreases as a result of the smoke. By the fourth week following the injection, zonal-mean surface precipitation in the tropics and summer hemisphere midlatitudes are about half of those in the control climate. The decrease is most notable over land, ocean precipitation being reduced only in the tropics. Penetrating convective precipitation is greatly reduced at all latitudes; large-scale precipitation is enhanced, becoming the dominant mode of precipitation in the simulation. Precipitation scavenging is shown to be the dominant removal process for particles larger than one micron in diameter. As a result, the lifetime of large particles increases several-fold due to the reduction in precipitation and the ''self-lofting'' of the smoke. For particles smaller than one micron in diameter, precipitation scavenging is found to be a much less efficient removal mechanism than both coagulation, which is important during the first week following the injection, and dry deposition at later times. 16 refs., 23 figs.
Allauzen, Cyril
applications or for adaptation purposes, one often needs to construct a language model based on the out- put library for language modeling, the GRM Library, that includes many other text and grammar processing classification. In all cases, a language model is used in combination with other in- formation sources to rank
Heisenberg XXX Model with General Boundaries: Eigenvectors from Algebraic Bethe Ansatz
Samuel Belliard; Nicolas Crampé
2013-11-22T23:59:59.000Z
We propose a generalization of the algebraic Bethe ansatz to obtain the eigenvectors of the Heisenberg spin chain with general boundaries associated to the eigenvalues and the Bethe equations found recently by Cao et al. The ansatz takes the usual form of a product of operators acting on a particular vector except that the number of operators is equal to the length of the chain. We prove this result for the chains with small length. We obtain also an off-shell equation (i.e. satisfied without the Bethe equations) formally similar to the ones obtained in the periodic case or with diagonal boundaries.
Heisenberg XXX model with general boundaries: Eigenvectors from Algebraic Bethe ansatz
Belliard, S
2013-01-01T23:59:59.000Z
We propose a generalization of the algebraic Bethe ansatz to obtain the eigenvectors of the Heisenberg spin chain with general boundaries associated to the eigenvalues and the Bethe equations found recently by Cao et al. The ansatz takes the usual form of a product of operators acting on a particular vector except that the number of operators is equal to the length of the chain. We prove this result for the chains with small length. We obtain also an off-shell equation (i.e. satisfied without the Bethe equations) formally similar to the ones obtained in the periodic case or with diagonal boundaries.
Laura Sampson; Neil Cornish; Nicolas Yunes
2013-03-05T23:59:59.000Z
We study generic tests of strong-field General Relativity using gravitational waves emitted during the inspiral of compact binaries. Previous studies have considered simple extensions to the standard post-Newtonian waveforms that differ by a single term in the phase. Here we improve on these studies by (i) increasing the realism of injections and (ii) determining the optimal waveform families for detecting and characterizing such signals. We construct waveforms that deviate from those in General Relativity through a series of post-Newtonian terms, and find that these higher-order terms can affect our ability to test General Relativity, in some cases by making it easier to detect a deviation, and in some cases by making it more difficult. We find that simple single-phase post-Einsteinian waveforms are sufficient for detecting deviations from General Relativity, and there is little to be gained from using more complicated models with multiple phase terms. The results found here will help guide future attempts to test General Relativity with advanced ground-based detectors.
Improved Indoor Tracking Based on Generalized t-Distribution Noise Model
Shuo, Liu; Le, Yin; Khuen, Ho Weng; Voon, Ling Keck
2015-01-01T23:59:59.000Z
log-distance path loss model (PLM) is commonly used [20]. Itclustered near the fitted PLM curve. B. Tracking of A Moving
Vassilis S. Geroyannis; Vasileios G. Karageorgopoulos
2014-09-30T23:59:59.000Z
We develop a "hybrid approximative scheme" in the framework of the post-Newtonian approximation for computing general-relativistic polytropic models simulating neutron stars in critical rigid rotation. We treat the differential equations governing such a model as a "complex initial value problem", and we solve it by using the so-called "complex-plane strategy". We incorporate into the computations the complete solution for the relativistic effects, this issue representing a significant improvement with regard to the classical post-Newtonian approximation, as verified by extended comparisons of the numerical results.
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.
Chandan Mondal; Dipankar Chakrabarti
2015-06-17T23:59:59.000Z
We present a study of the generalized parton distributions for the quarks in a proton in both momentum and position spaces using the light-front wave functions of a quark-diquark model for the nucleon predicted by the soft-wall model of AdS/QCD. The results are compared with the soft-wall AdS/QCD model of proton GPDs for zero skewness. We also calculate the GPDs for nonzero skewness. We observe that the GPDs have a diffraction pattern in longitudinal position space, as seen before in other models. Then we present a comparitive study of the nucleon charge and anomalous magnetization densities in the transverse plane. Flavor decompositions of the form factors and transverse densities are also discussed.
V. R. Gavrilov; V. N. Melnikov
1998-01-13T23:59:59.000Z
The D-dimensional cosmological model on the manifold $M = R \\times M_{1} \\times M_{2}$ describing the evolution of 2 Einsteinian factor spaces, $M_1$ and $M_2$, in the presence of multicomponent perfect fluid source is considered. The barotropic equation of state for mass-energy densities and the pressures of the components is assumed in each space. When the number of the non Ricci-flat factor spaces and the number of the perfect fluid components are both equal to 2, the Einstein equations for the model are reduced to the generalized Emden-Fowler (second-order ordinary differential) equation, which has been recently investigated by Zaitsev and Polyanin within discrete-group analysis. Using the integrable classes of this equation one generates the integrable cosmological models. The corresponding metrics are presented. The method is demonstrated for the special model with Ricci-flat spaces $M_1,M_2$ and the 2-component perfect fluid source.
de Souza, R S; Buelens, B; Riggs, J D; Cameron, E; Ishida, E E O; Chies-Santos, A L; Killedar, M
2015-01-01T23:59:59.000Z
In this paper, the third in a series illustrating the power of generalized linear models (GLMs) for the astronomical community, we elucidate the potential of the class of GLMs which handles count data. The size of a galaxy's globular cluster population $N_{\\rm GC}$ is a prolonged puzzle in the astronomical literature. It falls in the category of count data analysis, yet it is usually modelled as if it were a continuous response variable. We have developed a Bayesian negative binomial regression model to study the connection between $N_{\\rm GC}$ and the following galaxy properties: central black hole mass, dynamical bulge mass, bulge velocity dispersion, and absolute visual magnitude. The methodology introduced herein naturally accounts for heteroscedasticity, intrinsic scatter, errors in measurements in both axes (either discrete or continuous), and allows modelling the population of globular clusters on their natural scale as a non-negative integer variable. Prediction intervals of 99% around the trend for e...
A Flexible Climate Model For Use In Integrated Assessments Andrei P. Sokolov and Peter H. Stone
penetration into the deep ocean is comparable with that of other significant uncertainties. 1. Introduction with coupled atmosphere ocean general circulation models (AOGCMs) because of their tremendous computer resource with a diffusive ocean model developed for use in the integrated framework of the MIT Joint Program on the Science
Bledsoe, Brian
The Nature Conservancy, Fort Collins, Colorado USA ABSTRACT Dams and water diversions can dramatically alter the hydraulic habitats of stream ecosystems. Predicting how water depth and velocity respond to flow alteration is possible using hydraulic models, such as Physical Habitat Simulation (PHABSIM); however, such models
A new general model with non-spherical interactions for dense polymer systems and a
Heermann, Dieter W.
parametrization for Bisphenol-A-Polycarbonate Klaus M. Zimmer, Andreas Linke and Dieter W. Heermann Institut fur modeling of the monomer units. We apply the model to the special case of Bisphenol-A-Polycarbonate BPA on the thermodynamic properties of polycarbonate systems. We will also present properties and e ciency considerations
Competing mechanisms of chiral symmetry breaking in a generalized Gross-Neveu model
Boehmer, Christian; Thies, Michael [Institut fuer Theoretische Physik III, Universitaet Erlangen-Nuernberg, D-91058 Erlangen (Germany)
2010-05-15T23:59:59.000Z
Chiral symmetry of the 2-dimensional chiral Gross-Neveu model is broken explicitly by a bare mass term as well as a splitting of scalar and pseudoscalar coupling constants. The vacuum and light hadrons--mesons and baryons which become massless in the chiral limit--are explored analytically in leading order of the derivative expansion by means of a double sine-Gordon equation. Depending on the parameters, this model features new phenomena as compared to previously investigated 4-fermion models: spontaneous breaking of parity, a nontrivial chiral vacuum angle, twisted kinklike baryons whose baryon number reflects the vacuum angle, crystals with alternating baryons, and appearance of a false vacuum.
Superconformal generalization of the chaotic inflation model ?/4?{sup 4} - ?/2?{sup 2}R
Kallosh, Renata; Linde, Andrei, E-mail: kallosh@stanford.edu, E-mail: alinde@stanford.edu [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, CA 94305 (United States)
2013-06-01T23:59:59.000Z
A model of chaotic inflation based on the theory of a scalar field with potential ??{sup 4} perfectly matches the observational data if one adds to it a tiny non-minimal coupling to gravity -?/2?{sup 2} R with ??>0.002. We describe embedding of this model into the superconformal theory with spontaneous breaking of superconformal symmetry, and into supergravity. A model with small ? is technically natural: setting the small parameter ? to zero leads to a point of enhanced symmetry in the underlying superconformal theory.
A generalized nutrition model for Odocoileus deer and its application in a natural environment
Applegath, Matthew Thomas
2002-01-01T23:59:59.000Z
A model of protein and energy balance was created for Odocoileus deer [white-tailed deer (Odocoileus virginianus), mule deer (O. hemionus), and black-tailed deer (O. h. columbianus, O. h. sitkensis)] capable of predicting changes in body weight...
OLAF _ A General Modeling System to Evaluate and Optimize the Location of an Air
Fliege, Jörg
........................17 3.1.1The Standard Model ....................17 3.1.2Metabolism.1.2The Objective Function ..................40 5.1.3The Gradient of the Objective Function
Self-repelling fractional Brownian motion - a generalized Edwards model for chain polymers
Jinky Bornales; Maria João Oliveira; Ludwig Streit
2011-12-10T23:59:59.000Z
We present an extension of the Edwards model for conformations of individual chain molecules in solvents in terms of fractional Brownian motion, and discuss the excluded volume effect on the end-to-end length of such trajectories or molecules.
Re-analysis of deep excavation collapse using a generalized effective stress soil model
Corral Jofré, Gonzalo Andrés
2010-01-01T23:59:59.000Z
This thesis re-analyzes the well-documented failure of a 30m deep braced excavation underconsolidated marine clay. Prior analyses of the collapse of the Nicoll Highway have relied on simplified soil models with undrained ...
A general model of resource production and exchange in systems of interdependent specialists.
Conrad, Stephen Hamilton; Finley, Patrick D.; Beyeler, Walter Eugene; Brown, Theresa Jean; Glass, Robert John, Jr.; Breen, Peter; Kuypers, Marshall; Norton, Matthew David; Quach, Tu-Thach; Antognoli, Matthew; Mitchell, Michael David
2011-11-01T23:59:59.000Z
Infrastructures are networks of dynamically interacting systems designed for the flow of information, energy, and materials. Under certain circumstances, disturbances from a targeted attack or natural disasters can cause cascading failures within and between infrastructures that result in significant service losses and long recovery times. Reliable interdependency models that can capture such multi-network cascading do not exist. The research reported here has extended Sandia's infrastructure modeling capabilities by: (1) addressing interdependencies among networks, (2) incorporating adaptive behavioral models into the network models, and (3) providing mechanisms for evaluating vulnerability to targeted attack and unforeseen disruptions. We have applied these capabilities to evaluate the robustness of various systems, and to identify factors that control the scale and duration of disruption. This capability lays the foundation for developing advanced system security solutions that encompass both external shocks and internal dynamics.
Enabling Differentiated Services Using Generalized Power Control Model in Optical Networks
Zhu, Quanyan
2011-01-01T23:59:59.000Z
This paper considers a generalized framework to study OSNR optimization-based end-to-end link level power control problems in optical networks. We combine favorable features of game-theoretical approach and central cost approach to allow different service groups within the network. We develop solutions concepts for both cases of empty and nonempty feasible sets. In addition, we derive and prove the convergence of a distributed iterative algorithm for different classes of users. In the end, we use numerical examples to illustrate the novel framework.
General calculation model for reflection and transmission matrices of nanowire end facets
Svendsen, Guro K; Skaar, Johannes
2010-01-01T23:59:59.000Z
Nanowires show a large potential for various electrooptical devices, such as light emitting diodes, solar cells and nanowire lasers. We present a direct method developed to calculate the modal reflection and transmission matrix at the end facets of a waveguide of arbitrary cross section, resulting in a generalized version of the Fresnel equations. The reflection can be conveniently computed using Fast Fourier Transforms. We demonstrate that the reflection is qualitatively described by two main parameters, the modal field confinement and the average Fresnel reflection of the plane waves constituting the waveguide mode.
General Equilibrium Model for Economy - Energy - Environment (GEM-E3) |
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 Data Center Home Page on DeliciousPlasmaP aCentrothermDepew, New York:EssexInstitute for(Lewickisource History View NewGearyGemGenderGeneralOpen
Razzaghi, N
2015-01-01T23:59:59.000Z
We propose a phenomenological model of the Dirac neutrino mass matrix based on the Fridberg-Lee neutrino mass model at a special point. In this case, the Fridberg-Lee model reduces to the Democratic mass matrix with the $S_3$ permutation family symmetry. The Democratic mass matrix has an experimentally unfavored degenerate mass spectrum on the base of tribimaximal mixing matrix. We rescue the model to find a nondegenerate mass spectrum by adding the breaking mass term as preserving the twisted Fridberg-Lee symmetry. The tribimaximal mixing matrix can be also realized. Exact tribimaximal mixing leads to $\\theta_{13}=0$. However, the results from Daya Bay and RENO experiments have established a nonzero value for $\\theta_{13}$. Keeping the leading behavior of $U$ as tribimaximal, we use Broken Democratic neutrino mass model. We characterize a perturbation mass matrix which is responsible for a nonzero $\\theta_{13}$ along with CP violation, besides the solar neutrino mass splitting has been resulted from it. We c...
A general approach to develop reduced order models for simulation of solid oxide fuel cell stacks
Pan, Wenxiao; Bao, Jie; Lo, Chaomei; Lai, Canhai; Agarwal, Khushbu; Koeppel, Brian J.; Khaleel, Mohammad A.
2013-06-15T23:59:59.000Z
A reduced order modeling approach based on response surface techniques was developed for solid oxide fuel cell stacks. This approach creates a numerical model that can quickly compute desired performance variables of interest for a stack based on its input parameter set. The approach carefully samples the multidimensional design space based on the input parameter ranges, evaluates a detailed stack model at each of the sampled points, and performs regression for selected performance variables of interest to determine the responsive surfaces. After error analysis to ensure that sufficient accuracy is established for the response surfaces, they are then implemented in a calculator module for system-level studies. The benefit of this modeling approach is that it is sufficiently fast for integration with system modeling software and simulation of fuel cell-based power systems while still providing high fidelity information about the internal distributions of key variables. This paper describes the sampling, regression, sensitivity, error, and principal component analyses to identify the applicable methods for simulating a planar fuel cell stack.
Agarwala, R. [National Institutes of Health, Bethesda, MD (United States); Batzoglou, S. [MIT Lab. for Computer Science, Cambridge, MA (United States); Dancik, V. [Univ. of Southern California, Los Angeles, CA (United States)] [and others
1997-12-01T23:59:59.000Z
A long standing problem in molecular biology is to determine the three-dimensional structure of a protein, given its amino acid sequence. A variety of simplifying models have been proposed abstracting only the {open_quotes}essential physical properties{close_quotes} of real proteins. In these models, the three dimensional space is often represented by a lattice. Residues which are adjacent in the primary sequence (i.e. covalently linked) must be placed at adjacent points in the lattice. A conformation of a protein is simply a self-avoiding walk along the lattice. The protein folding problem STRING-FOLD is that of finding a conformation of the protein sequence on the lattice such that the overall energy is minimized, for some reasonable definition of energy. This formulation leaves open the choices of a lattice and an energy function. Once these choices are made, one may then address the algorithmic complexity of optimizing the energy function for the lattice. For a variety of such simple models, this minimization problem is in fact NP-hard. In this paper, we consider the Hydrophobic-Polar (HP) Model introduced by Dill. The HP model abstracts the problem by grouping the 20 amino acids into two classes: hydrophobic (or non-polar) residues and hydrophilic (or polar) residues. For concreteness, we will take our input to be a string from (H,P){sup +}, where P represents polar residues, and H represents hydrophobic residues. Dill et.al. survey the literature analyzing this model. 8 refs., 2 figs., 1 tab.
Factored Language Models and Generalized Parallel Backoff Jeff A. Bilmes Katrin Kirchhoff
Washington at Seattle, University of
model, a word is viewed as a vec- tor of k factors, so that wt {f1 t , f2 t , . . . , fK t }. Fac- tors. An FLM is a model over factors, i.e., p(f1:K t |f1:K t-1:t-n), that can be factored as a product of probabilities of the form p(f|f1, f2, . . . , fN ). Our task is twofold: 1) find an appropriate set of factors
Richard P. Sear
2013-07-29T23:59:59.000Z
Models without an explicit time dependence, called singular models, are widely used for fitting the distribution of temperatures at which water droplets freeze. In 1950 Levine developed the original singular model. His key assumption was that each droplet contained many nucleation sites, and that freezing occurred due to the nucleation site with the highest freezing temperature. The fact that freezing occurs due to the maximum value out of large number of nucleation temperatures, means that we can apply the results of what is called extreme-value statistics. This is the statistics of the extreme, i.e., maximum or minimum, value of a large number of random variables. Here we use the results of extreme-value statistics to show that we can generalise Levine's model to produce the most general singular model possible. We show that when a singular model is a good approximation, the distribution of freezing temperatures should always be given by what is called the generalised extreme-value distribution. In addition, we also show that the distribution of freezing temperatures for droplets of onesize, can be used to make predictions for the scaling of the median nucleation temperature with droplet size, and vice versa.
Sanandaji, Borhan M.
Ancillary Service He Hao, Borhan M. Sanandaji, Kameshwar Poolla, and Tyrone L. Vincent Abstract for providing various ancillary services to the grid. In this work, we study aggregate modeling, and uncontrollability of renewable resources. To ensure the func- tionality and reliability of the grid, more ancillary
Negative specific heat in a quasi-2D generalized vorticity model T. D. Andersen
Lim, Chjan C.
) model for the unbounded plane under strong magnetic confinement. We derive the specific heat using, this results in a runaway reaction leading to a collapse of the cluster. In a magnetic fusion system or other- found implications for fusion where extreme confinement is critical to a sustained reaction
A Generalized Cohesive Zone Model of Peel Test for Pressure Sensitive Adhesives
Zhang, Liang
2010-01-16T23:59:59.000Z
study, the mechanics of the peel test is analyzed based on a cohesive zone model. Cohesive failure is assumed to prevail in the vicinity of the peel front, that is, the adhesive fails not by debonding from the adherends but by splitting of the adhesive...
Separating expansion from contraction: generalized TOV condition, LTB models with pressure and CDM
Paris-Sud XI, UniversitÃ© de
, we adopt the Generalised PainlevÃ©-Gullstrand (hereafter GPG) formalism used in Lasky & Lun [6], which TO LTB MODELS IN GPG SYSTEM We consider a spherically symmetric Generalised LemaÃ®tre-Tolman-Bondi metric to include pressure. Performing an ADM 3+1 splitting in the GPG coordinates [6] , the metric reads ds2 = -(t
Finite-temperature properties of the generalized Falicov-Kimball model S. El Shawish,1
Bonèa, Janez
Laboratory, Los Alamos, New Mexico 87545, USA Received 4 July 2003; published 18 November 2003 in intermediate valence com- pounds. A renewed interest in this model started when Por- tengen et al.2 suggested an important role in defining the nature of the low energy spectrum of the ferroelectric state.4 For simplicity
Description of FLIPSIM V: a General Firm Level Policy Simulation Model.
Richardson, James W.; Nixon, Clair J.
1986-01-01T23:59:59.000Z
................................................ 25 Subroutine FINAN .. .. ............................ . ................ 26 Subroutine LANDVL ............................................... 26 Subroutine DEPREC .............. . ................................. 27 Subroutine LEASE... the flexibility to lease farm machinery, and (g) adding a quadratic programming algorithm to determine crop mix. The model was .developed to allow analysis of the probable consequences of' alternative farm policies and income tax developments on typical...
James, Stephen M.
2011-08-08T23:59:59.000Z
? Bearings used in component-mode-synthesis model [ ]C ? System damping matrix in Guyan reduction model [ ]cscC ? Transformed casing damping matrix due to seal force on casing [ ]csrC ? Transformed casing damping matrix due to seal force on rotor... ; 1: , 1:ijc i m j n= = ? Damping matrix element [FTL-1] c ; 1:j j = n ? jth casing station CMS ? Component Mode Synthesis rscc ? Damping element entry in rotor due to seal force on casing [FTL-1] [ ]rscC ? Transformed rotor damping...
Recent technology improvements in Exxon's circulating zinc-bromine battery system
Bellows, R.J.
1981-01-01T23:59:59.000Z
Recent electrode and electrolyte performance on 500 wH and 3 kWh units indicates that Exxon's circulating zinc-bromine battery in 20 kWh designs will be capable of high energy density (65 to 70 wH/kg), and turn-around efficiency (65 to 70%). This performance, coupled with recent factory cost projections of $28/kWh (exclusive of R.O.I. and various indirect overheads), makes zinc/bromine an attractive advanced battery candidate for not only photovoltaic, but also electric vehicle and bulk energy storage applications. Recent technical developments in this program may be generally useful in other circulating electrolyte systems.
Jensen, Tommy
steps are taken to reduce the potential energy barrier to sacks crossing one another, the model the northern boundary for a time. Taking advantage of the new mixing scheme and lessons learned from Institute of Technol- ogy general circulation model (MITgcm). The SSOM and the MITgcm produce similar wind
ISO-SWS calibration and the accurate modelling of cool-star atmospheres - II. General results
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.
Horwitz, Rachel Mandy
2012-01-01T23:59:59.000Z
Observations from a three-year field program on the inner shelf south of Martha's Vineyard, MA and a numerical model are used to describe the effect of stratification on inner shelf circulation, transport, and sediment ...
Description of FLIPSIM V: a General Firm Level Policy Simulation Model.
Richardson, James W.; Nixon, Clair J.
1986-01-01T23:59:59.000Z
-basis taxpayer for federal income purposes, depreciation is calculated for each item in the machinery complement, as well as purchased breeding stock, milk cows, and buildings. For depreciable items purchased before 1981, the model calculates depreciation... using the analyst's specified method. either the double declining balance or the straight line method. Depreciable items placed into service after 1980 and before 1986, are cost recovered using either an accelerated (double declining balance...
Examining the Generalized Waring Model for the Analysis of Traffic Crashes
Peng, Yichuan
2013-05-03T23:59:59.000Z
Figure 5.19 Sensitivity analysis of covariate ADT for Michigan data ........................ 95 Figure 6.1 Comparison of rankings between NB and GW models ............................. 99 x LIST OF TABLES... sites based on the available information, such as traffic flow and other road geometric variables. They also can be used to investigate specific or significant effects of the variables on the risk of the collision. In addition, the number of 2...
Experimental analysis of the mechanics of reverse circulation air lift
Zeineddine, Talal Ibrahim
1980-01-01T23:59:59.000Z
investigation of the two-phase air-water flow in the lifting pipe of an air lift pump model was conducted. The effect of the diffuser design on the efficiency of the pump was then determined. The experimental study consisted of measuring the void frac- tion... circulation air lift device as a function of diffuser configuration. The two-phase flow in the vertical lifting pipe of the pump was studied in detail so that the flow parameters and their variations across and along the pipe were investigated...
Towards a general analysis of LHC data within two-Higgs-doublet models
Celis, Alejandro; Pich, Antonio
2013-01-01T23:59:59.000Z
The data accumulated so far confirm the Higgs-like nature of the new boson discovered at the LHC. The Standard Model Higgs hypothesis is compatible with the collider results and no significant deviations from the Standard Model have been observed neither in the flavour sector nor in electroweak precision observables. We update the LHC and Tevatron constraints on CP-conserving two-Higgs-doublet models without tree-level flavour-changing neutral currents. While the relative sign between the top Yukawa and the gauge coupling of the $126$ GeV Higgs is found be the same as in the SM, at $90%$ CL, there is a sign degeneracy in the determination of its bottom and tau Yukawa couplings. This results in several disjoint allowed regions in the parameter space. We show how generic sum rules governing the scalar couplings determine the properties of the additional Higgs bosons in the different allowed regions. The role of electroweak precision observables, low-energy flavour constraints and LHC searches for additional sca...
Goodness-of-Fit Test Issues in Generalized Linear Mixed Models
Chen, Nai-Wei
2012-02-14T23:59:59.000Z
checking of Case 1 for (1)ZSm and (2)cS tran m . . . 58 13 Results of the type I error rate of Sm by using local polynomial smoothed residuals are computed based on the scaled chi-squared distribution cSm...-cluster interaction term of fixed effects between two con- tinuous covariates when the alternative model (4.6) is assumed. . . . 64 17 Results of controlling type I error rate of Sm by using local poly- nomial smoothed residuals are computed based on cSm when...
ResearchNews Please circulate to
Anderson, Paul R.
.6%); and the Advanced Research Projects Agency-Energy, $350M to support early-stage projects that may leadResearchNews Please circulate to: The Office of Research and Sponsored Programs welcomes Amy L of experience in Research Administration and strong knowledge of all phases of proposal development, including
Vertical mixing and the ocean circulation
Jones, Peter JS
Changing sources of mixing Hurricanes Tidal dissipation 2 #12;Zonal Mean Ocean Temperature 3 #12;Sandström's Theorem A circulation cannot be driven unless heat is input at a lower depth than it is lost in the ocean? Wind-driven stirring Tidal generation of internal waves Biota Hurricanes Nasa 6 #12;Sources
Renormalization of lattice-regularized quantum gravity models I. General considerations
Joshua H. Cooperman
2014-10-21T23:59:59.000Z
Lattice regularization is a standard technique for the nonperturbative definition of a quantum theory of fields. Several approaches to the construction of a quantum theory of gravity adopt this technique either explicitly or implicitly. A crucial complement to lattice regularization is the process of renormalization through which a continuous description of the quantum theory arises. I provide a comprehensive conceptual discussion of the renormalization of lattice-regularized quantum gravity models. I begin with a presentation of the renormalization group from the Wilsonian perspective. I then consider the application of the renormalization group in four contexts: quantum field theory on a continuous nondynamical spacetime, quantum field theory on a lattice-regularized nondynamical spacetime, quantum field theory of continuous dynamical spacetime, and quantum field theory of lattice-regularized dynamical spacetime. The first three contexts serve to identify successively the particular issues that arise in the fourth context. These issues originate in the inescability of establishing all scales solely on the basis of the dynamics. While most of this discussion rehearses established knowledge, the attention that I pay to these issues, especially the previously underappreciated role of standard units of measure, is largely novel. I conclude by briefly reviewing past studies of renormalization of lattice-regularized quantum gravity models. In the second paper of this two-part series, I illustrate the ideas presented here by proposing a renormalization group scheme for causal dynamical triangulations.
DOPPLER SIGNATURES OF THE ATMOSPHERIC CIRCULATION ON HOT JUPITERS
Showman, Adam P.; Lewis, Nikole K. [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, 1629 University Boulevard, Tucson, AZ 85721 (United States)] [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, 1629 University Boulevard, Tucson, AZ 85721 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)] [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Shabram, Megan, E-mail: showman@lpl.arizona.edu [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States)] [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States)
2013-01-01T23:59:59.000Z
The meteorology of hot Jupiters has been characterized primarily with thermal measurements, but recent observations suggest the possibility of directly detecting the winds by observing the Doppler shift of spectral lines seen during transit. Motivated by these observations, we show how Doppler measurements can place powerful constraints on the meteorology. We show that the atmospheric circulation-and Doppler signature-of hot Jupiters splits into two regimes. Under weak stellar insolation, the day-night thermal forcing generates fast zonal jet streams from the interaction of atmospheric waves with the mean flow. In this regime, air along the terminator (as seen during transit) flows toward Earth in some regions and away from Earth in others, leading to a Doppler signature exhibiting superposed blueshifted and redshifted components. Under intense stellar insolation, however, the strong thermal forcing damps these planetary-scale waves, inhibiting their ability to generate jets. Strong frictional drag likewise damps these waves and inhibits jet formation. As a result, this second regime exhibits a circulation dominated by high-altitude, day-to-night airflow, leading to a predominantly blueshifted Doppler signature during transit. We present state-of-the-art circulation models including non-gray radiative transfer to quantify this regime shift and the resulting Doppler signatures; these models suggest that cool planets like GJ 436b lie in the first regime, HD 189733b is transitional, while planets hotter than HD 209458b lie in the second regime. Moreover, we show how the amplitude of the Doppler shifts constrains the strength of frictional drag in the upper atmospheres of hot Jupiters. If due to winds, the {approx}2 km s{sup -1} blueshift inferred on HD 209458b may require drag time constants as short as 10{sup 4}-10{sup 6} s, possibly the result of Lorentz-force braking on this planet's hot dayside.
Walter Del Pozzo; John Veitch; Alberto Vecchio
2011-01-07T23:59:59.000Z
Second generation interferometric gravitational wave detectors, such as Advanced LIGO and Advanced Virgo, are expected to begin operation by 2015. Such instruments plan to reach sensitivities that will offer the unique possibility to test General Relativity in the dynamical, strong field regime and investigate departures from its predictions, in particular using the signal from coalescing binary systems. We introduce a statistical framework based on Bayesian model selection in which the Bayes factor between two competing hypotheses measures which theory is favored by the data. Probability density functions of the model parameters are then used to quantify the inference on individual parameters. We also develop a method to combine the information coming from multiple independent observations of gravitational waves, and show how much stronger inference could be. As an introduction and illustration of this framework - and a practical numerical implementation through the Monte Carlo integration technique of nested sampling - we apply it to gravitational waves from the inspiral phase of coalescing binary systems as predicted by General Relativity and a very simple alternative theory in which the graviton has a non-zero mass. This method can trivially (and should) be extended to more realistic and physically motivated theories.
Truong, Thanh N.
A general methodology for quantum modeling of free-energy profile of reactions in solution methodology for calculating free-energy profile of reaction in solution using quantum mechanical methods screening model GCOSMO was employed in this study, though any continuum model with existing free-energy
A General Relativistic Model for Magnetic Monopole-Infused Compact Objects
Zoran Pazameta
2012-01-30T23:59:59.000Z
Emergent concepts from astroparticle physics are incorporated into a classical solution of the Einstein-Maxwell equations for a binary magnetohydrodynamic fluid, in order to describe the final equilibrium state of compact objects infused with magnetic monopoles produced by proton-proton collisions within the intense dipolar magnetic fields generated by these objects during their collapse. It is found that the effective mass of such an object's acquired monopolar magnetic field is three times greater than the mass of its native fluid and monopoles combined, necessitating that the interior matter undergo a transition to a state of negative pressure in order to attain equilibrium. Assuming full symmetry between the electric and magnetic Maxwell equations yields expressions for the monopole charge density and magnetic field by direct analogy with their electrostatic equivalents; inserting these into the Einstein equations then leads to an interior metric which is well-behaved from the origin to the surface, where it matches smoothly to an exterior magnetic Reissner-Nordstr\\"om metric free of any coordinate pathologies. The source fields comprising the model are all described by simple, well-behaved polynomial functions of the radial coordinate, and are combined with straightforward regularity conditions to yield expressions delimiting several fundamental physical parameters pertaining to this hypothetical astrophysical object.
M. Wakamatsu; H. Tsujimoto
2005-03-29T23:59:59.000Z
The theoretical predictions are given for the forward limit of the unpolarized spin-flip isovector generalized parton distribution function $(E^u - E^d)(x, \\xi, t)$ within the framework of the chiral quark soliton model, with full inclusion of the polarization of Dirac sea quarks. We observe that $[(H^u - H^d) + (E^u - E^d)](x,0,0)$ has a sharp peak around $x=0$, which we interpret as a signal of the importance of the pionic $q \\bar{q}$ excitation with large spatial extension in the transverse direction. Another interesting indication given by the predicted distribution in combination with Ji's angular momentum sum rule is that the $\\bar{d}$-quark carries more angular momentum than the $\\bar{u}$-quark in the proton, which may have some relation with the physics of the violation of the Gottfried sum rule.
Continuous Circulation System: a new enabling technology
Kenawy, Walid F.
2002-01-01T23:59:59.000Z
time-consuming hole problems trom occurring. It is worth mentioning that pipe rotation is as important for prevention of settling of cuttings as sufficient circulation, as the rotation of the drill pipe acts to agitate any solids settled back... rotation enhances the hole cleaning by the agitation effect of rotation and vibration . ' ' Since one of the main advantages of the CCS is to keep the cuttings moving towards the surface, then the idea of modifying the CCS to allow for drillstring...
Cluster Dynamics in a Circulating Fluidized Bed
Guenther, C.P.; Breault, R.W.
2006-11-01T23:59:59.000Z
A common hydrodynamic feature in industrial scale circulating fluidized beds is the presence of clusters. The continuous formation and destruction of clusters strongly influences particle hold-up, pressure drop, heat transfer at the wall, and mixing. In this paper fiber optic data is analyzed using discrete wavelet analysis to characterize the dynamic behavior of clusters. Five radial positions at three different axial locations under five different operating were analyzed using discrete wavelets. Results are summarized with respect to cluster size and frequency.
Reducing mode circulating fluid bed combustion
Lin, Yung-Yi (Katy, TX); Sadhukhan, Pasupati (Katy, TX); Fraley, Lowell D. (Sugarland, TX); Hsiao, Keh-Hsien (Houston, TX)
1986-01-01T23:59:59.000Z
A method for combustion of sulfur-containing fuel in a circulating fluid bed combustion system wherein the fuel is burned in a primary combustion zone under reducing conditions and sulfur captured as alkaline sulfide. The reducing gas formed is oxidized to combustion gas which is then separated from solids containing alkaline sulfide. The separated solids are then oxidized and recycled to the primary combustion zone.
NUCLA Circulating Atmospheric Fluidized Bed Demonstration Project
Not Available
1992-02-01T23:59:59.000Z
The objective of this DOE Cooperative Agreement is to conduct a cost-shared clean coal technology project to demonstrate the feasibility of circulating fluidized bed combustion technology and to evaluate economic, environmental, and operational benefits of CFB steam generators on a utility scale. At the conclusion of the Phase 2 program, testing related to satisfying these objectives was completed. Data analysis and reporting are scheduled for completion by October 1991. (VC)
Holanda, R.F.L.; Lima, J.A.S. [Departamento de Astronomia (IAGUSP), Universidade de São Paulo, Rua do Matão 1226, 05508-900, São Paulo, SP (Brazil); Cunha, J.V. [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adélia 166, 09210-170, Santo André, SP (Brazil); Marassi, L., E-mail: holanda@astro.iag.usp.br, E-mail: jvcunha@ufpa.br, E-mail: luciomarassi@ect.ufrn.br, E-mail: limajas@astro.iag.usp.br [Escola de Ciência e Tecnologia, UFRN, 59072-970, Natal, RN (Brazil)
2012-02-01T23:59:59.000Z
In accelerating dark energy models, the estimates of the Hubble constant, H{sub 0}, from Sunyaev-Zel'dovich effect (SZE) and X-ray surface brightness of galaxy clusters may depend on the matter content (?{sub M}), the curvature (?{sub K}) and the equation of state parameter (?). In this article, by using a sample of 25 angular diameter distances of galaxy clusters described by the elliptical ? model obtained through the SZE/X-ray technique, we constrain H{sub 0} in the framework of a general ?CDM model (arbitrary curvature) and a flat XCDM model with a constant equation of state parameter ? = p{sub x}/?{sub x}. In order to avoid the use of priors in the cosmological parameters, we apply a joint analysis involving the baryon acoustic oscillations (BAO) and the CMB Shift Parameter signature. By taking into account the statistical and systematic errors of the SZE/X-ray technique we obtain for nonflat ?CDM model H{sub 0} = 74{sup +5.0}{sub ?4.0} km s{sup ?1} Mpc{sup ?1}(1?) whereas for a flat universe with constant equation of state parameter we find H{sub 0} = 72{sup +5.5}{sub ?4.0} km s{sup ?1} Mpc{sup ?1}(1?). By assuming that galaxy clusters are described by a spherical ? model these results change to H{sub 0} = 62{sup +8.0}{sub ?7.0} and H{sub 0} = 59{sup +9.0}{sub ?6.0} km s{sup ?1} Mpc{sup ?1}(1?), respectively. The results from elliptical description are in good agreement with independent studies from the Hubble Space Telescope key project and recent estimates based on the Wilkinson Microwave Anisotropy Probe, thereby suggesting that the combination of these three independent phenomena provides an interesting method to constrain the Hubble constant. As an extra bonus, the adoption of the elliptical description is revealed to be a quite realistic assumption. Finally, by comparing these results with a recent determination for a flat ?CDM model using only the SZE/X-ray technique and BAO, we see that the geometry has a very weak influence on H{sub 0} estimates for this combination of data.
Eocene circulation of the Southern Ocean: Was Antarctica kept warm by subtropical waters?
Döös, Kristofer
climate model simulations. We find that the EAC did not penetrate to high latitudes and ocean heatEocene circulation of the Southern Ocean: Was Antarctica kept warm by subtropical waters? Matthew suddenly grew and ocean productivity patterns changed. Previous studies conjectured that poleward
A numerical study of circulation and mixing in a macrotidal estuary: Cobscook Bay, Maine
Baca, Michael William
1998-01-01T23:59:59.000Z
A numerical, three-dimensional coastal ocean model was ics. used to study the circulation and subsequent mixing of Cobscook Bay by the lunar semi-diurnal tide. The results showed strong ebbing and flooding currents along a main channel connected...
Heinemann, Detlev
IDENTIFICATION OF A GENERAL MODEL FOR THE MPP PERFORMANCE OF PV-MODULES FOR THE APPLICATION. ABSTRACT: To assure the maximal energy yield of grid connected PV systems, system faults have of this model for the application to grid connected PV systems using cSi, aSi and CIS modules is demonstrated. 1
TRANSPORT BY MERIDIONAL CIRCULATIONS IN SOLAR-TYPE STARS
Wood, T. S.; Brummell, N. H., E-mail: tsw25@soe.ucsc.edu [Department of Applied Mathematics and Statistics, Baskin School of Engineering, University of California Santa Cruz, CA (United States)
2012-08-20T23:59:59.000Z
Transport by meridional flows has significant consequences for stellar evolution, but is difficult to capture in global-scale numerical simulations because of the wide range of timescales involved. Stellar evolution models therefore usually adopt parameterizations for such transport based on idealized laminar or mean-field models. Unfortunately, recent attempts to model this transport in global simulations have produced results that are not consistent with any of these idealized models. In an effort to explain the discrepancies between global simulations and idealized models, here we use three-dimensional local Cartesian simulations of compressible convection to study the efficiency of transport by meridional flows below a convection zone in several parameter regimes of relevance to the Sun and solar-type stars. In these local simulations we are able to establish the correct ordering of dynamical timescales, although the separation of the timescales remains unrealistic. We find that, even though the generation of internal waves by convective overshoot produces a high degree of time dependence in the meridional flow field, the mean flow has the qualitative behavior predicted by laminar, 'balanced' models. In particular, we observe a progressive deepening, or 'burrowing', of the mean circulation if the local Eddington-Sweet timescale is shorter than the viscous diffusion timescale. Such burrowing is a robust prediction of laminar models in this parameter regime, but has never been observed in any previous numerical simulation. We argue that previous simulations therefore underestimate the transport by meridional flows.
THREE-DIMENSIONAL ATMOSPHERIC CIRCULATION OF HOT JUPITERS ON HIGHLY ECCENTRIC ORBITS
Kataria, T.; Showman, A. P.; Lewis, N. K. [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States)] [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Fortney, J. J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)] [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Marley, M. S.; Freedman, R. S., E-mail: tkataria@lpl.arizona.edu [NASA Ames Research Center 245-3, Moffett Field, CA 94035 (United States)
2013-04-10T23:59:59.000Z
Of the over 800 exoplanets detected to date, over half are on non-circular orbits, with eccentricities as high as 0.93. Such orbits lead to time-variable stellar heating, which has major implications for the planet's atmospheric dynamical regime. However, little is known about the fundamental dynamical regime of such planetary atmospheres, and how it may influence the observations of these planets. Therefore, we present a systematic study of hot Jupiters on highly eccentric orbits using the SPARC/MITgcm, a model which couples a three-dimensional general circulation model (the MITgcm) with a plane-parallel, two-stream, non-gray radiative transfer model. In our study, we vary the eccentricity and orbit-average stellar flux over a wide range. We demonstrate that the eccentric hot Jupiter regime is qualitatively similar to that of planets on circular orbits; the planets possess a superrotating equatorial jet and exhibit large day-night temperature variations. As in Showman and Polvani, we show that the day-night heating variations induce momentum fluxes equatorward to maintain the superrotating jet throughout its orbit. We find that as the eccentricity and/or stellar flux is increased (corresponding to shorter orbital periods), the superrotating jet strengthens and narrows, due to a smaller Rossby deformation radius. For a select number of model integrations, we generate full-orbit light curves and find that the timing of transit and secondary eclipse viewed from Earth with respect to periapse and apoapse can greatly affect what we see in infrared (IR) light curves; the peak in IR flux can lead or lag secondary eclipse depending on the geometry. For those planets that have large temperature differences from dayside to nightside and rapid rotation rates, we find that the light curves can exhibit 'ringing' as the planet's hottest region rotates in and out of view from Earth. These results can be used to explain future observations of eccentric transiting exoplanets.
Wind induced circulation on the outer continental shelf of Texas, spring 1982
Beard, Daniel Walker
1984-01-01T23:59:59.000Z
in the record is offshore, to the southeast. On the 29th of March, in the wake of strong northeast winds, the current shifted to the west. In general, the westward direction was maintained throughout the deployment period. However, there was one occurrence... WIND INDUCED CIRCULATION ON THE OUTER CONTINENTAL SHELF OF TEXAS, SPRING 1982 A Thesis by DANIEL WALKER BEARD Submitted to the Graduate College of Texas AE M University in partial fulfillment of the requirements for the degree of MASTER...
The effects of small perturbations in climate models
Bell, Robert Eugene
1991-01-01T23:59:59.000Z
An energy balance model . II. 2 Equilibrium statistics 5 12 III A GENERAL CIRCULATION MODEL . . III. 1 Terra Blimda . III. 2 Equilibrium statistics 15 18 IV THE EFFECTS OF SMALL PERTURBATIONS . . 21 IV. 1 Response to a, Dirac delta, function IV. 2... standard deviations from the mean. , Relaxation time for different modes as a function of Legendre index n (North and Cahalan, 1981). 13 Illustration of a, rhomboidal truncation at degree 5 (R5). 17 The global mean surface temperature of Terra Blanda...
T. P. Shestakova
2013-03-06T23:59:59.000Z
Among theoretical issues in General Relativity the problem of constructing its Hamiltonian formulation is still of interest. The most of attempts to quantize Gravity are based upon Dirac generalization of Hamiltonian dynamics for system with constraints. At the same time there exists another way to formulate Hamiltonian dynamics for constrained systems guided by the idea of extended phase space. We have already considered some features of this approach in the previous MG12 Meeting by the example of a simple isotropic model. Now we apply the approach to a generalized spherically symmetric model which imitates the structure of General Relativity much better. In particular, making use of a global BRST symmetry and the Noether theorem, we construct the BRST charge that generates correct gauge transformations for all gravitational degrees of freedom.
Reversing the Circulation of Magnetic Vortices
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (Million CubicRefiners SwitchBenefits Â» Retirement Retirement RetirementReversing the Circulation
Nucla circulating atmospheric fluidized bed demonstration project
Not Available
1991-01-31T23:59:59.000Z
During the fourth quarter of 1990, steady-state performance testing at the Nucla Circulating Fluidized Bed (CFB) resumed under sponsorship of the US Department of Energy. Co-sponsorship of the Demonstration Test Program by the Electric Power Research Institute (EPRI) was completed on June 15, 1990. From October through December, 1990, Colorado-Ute Electric Association (CUEA) completed a total of 23 steady-state performance tests, 4 dynamic tests, and set operating records during November and December as the result of improved unit operating reliability. Highlight events and achievements during this period of operation are presented.
Prospects for the Detection of the Deep Solar Meridional Circulation
D. C. Braun; A. C. Birch
2008-10-01T23:59:59.000Z
We perform helioseismic holography to assess the noise in p-mode travel-time shifts which would form the basis of inferences of large-scale flows throughout the solar convection zone. We also derive the expected travel times from a parameterized return (equatorward) flow component of the meridional circulation at the base of the convection zone from forward models under the assumption of the ray and Born approximations. From estimates of the signal-to-noise ratio for measurements focused near the base of the convection zone, we conclude that the helioseismic detection of the deep meridional flow including the return component may not be possible using data spanning an interval less than a solar cycle.
Rhode Island, University of
Impact of a Warm Ocean Eddy's Circulation on Hurricane-Induced Sea Surface Cooling with Implications for Hurricane Intensity RICHARD M. YABLONSKY AND ISAAC GINIS Graduate School of Oceanography) ABSTRACT Upper oceanic heat content (OHC) in advance of a hurricane is generally superior to prestorm sea
Generalized interaction in multigravity
Duplij, Steven
2013-01-01T23:59:59.000Z
A general approach to description of multigravity models in D-dimensional space-time is presented. Different possibilities of generalization of the invariant volume are given. Then a most general form of the interaction potential is constructed, which for bigravity coincides with the Pauli-Fierz model. A thorough analysis of the model along the 3+1 expansion formalism is done. It is shown that the absence of ghosts the considered bigravity model is equivalent in the weak field limit to the massive gravity (the Pauli-Fierz model). Thus, on the concrete example it is shown, that the interaction between metrics leads to nonvanishing mass of graviton.
Fluid Circulation and Heat Extraction from Engineered Geothermal...
A large amount of fluid circulation and heat extraction (i.e., thermal power production) research and testing has been conducted on engineered geothermal reservoirs in the...
Primary cementing across massive lost circulation zones
Turki, W.H.; Mackay, A.S.
1983-03-01T23:59:59.000Z
As a result of severe lost circulation problems in some wells in the Ghawar and Abqaiq Fields, Aramco has been unable to cover the Umm Er-Radhuma (Paleocene) and Wasia (Cretaceous) aquifers with cement. This has necessitated setting an extended liner opposite the Wasia aquifer, to ensure that there are two casing strings and a cement sheath across the aquifer, resulting in increased casing cost and reduced well productivity. This paper describes the results of field trial tests performed, along with conclusions and recommendations aimed at solving this problem. Field methods employed include light weight extended cements, ultra-light cement slurries weighing as little as 55 lbm/ft/sup 3/ (pcf), using ceramic hollow spheres, glass bubbles and foam, plus hydrostatic cementing, and mechanical devices. Finally, methods of job evaluation are discussed. These include temperature surveys, bond logs, radioactive tracers, and a new cement volume log.
Nucla circulating atmospheric fluidized bed demonstration project
Keith, Raymond E.
1991-10-01T23:59:59.000Z
Colorado-Ute Electric Association began a study to evaluate options for upgrading and extending the life of its Nucla power station in 1982. Located in southwestern Colorado near the town of Nucla, this station was commissioned in 1959 with a local bituminous coal as its design fuel for three identical stoker-fired units, each rated at 12.6 MW(e). Poor station efficiency, high fuel costs, and spiraling boiler maintenance costs forced the Nucla Station into low priority in the CUEA dispatch order as early as 1981. Among the options CUEA considered was to serve as a host utility to demonstrate Atmospheric Fluidized Bed Combustion (AFBC) technology. The anticipated environmental benefits and apparent attractive economics of a circulating AFBC led to Colorado-Ute's decision to proceed with the design and construction of a demonstration project in 1984 at the Nucla facility.
Thermodynamics of atmospheric circulation on hot Jupiters
J. Goodman
2008-10-07T23:59:59.000Z
Atmospheric circulation on tidally-locked exoplanets is driven by the absorption and reradiation of heat from the host star. They are natural heat engines, converting heat into mechanical energy. A steady state is possible only if there is a mechanism to dissipate mechanical energy, or if the redistribution of heat is so effective that the Carnot efficiency is driven to zero. Simulations based on primitive, equivalent-barotropic, or shallow-water equations without explicit provision for dissipation of kinetic energy and for recovery of that energy as heat, violate energy conservation. More seriously perhaps, neglect of physical sources of drag may overestimate wind speeds and rates of advection of heat from the day to the night side.
nested circulation models is used to explore interannual change in the northeast Pacific (NEP) during-km resolution (NPac), and a regional model of the Northeast Pacific at $10-km resolution. The NEP outside of the NEP domain; ``local influence'' refers to direct forcing by winds and runoff within the NEP
Uncertainty quantification for large-scale ocean circulation predictions.
Safta, Cosmin; Debusschere, Bert J.; Najm, Habib N.; Sargsyan, Khachik
2010-09-01T23:59:59.000Z
Uncertainty quantificatio in climate models is challenged by the sparsity of the available climate data due to the high computational cost of the model runs. Another feature that prevents classical uncertainty analyses from being easily applicable is the bifurcative behavior in the climate data with respect to certain parameters. A typical example is the Meridional Overturning Circulation in the Atlantic Ocean. The maximum overturning stream function exhibits discontinuity across a curve in the space of two uncertain parameters, namely climate sensitivity and CO{sub 2} forcing. We develop a methodology that performs uncertainty quantificatio in the presence of limited data that have discontinuous character. Our approach is two-fold. First we detect the discontinuity location with a Bayesian inference, thus obtaining a probabilistic representation of the discontinuity curve location in presence of arbitrarily distributed input parameter values. Furthermore, we developed a spectral approach that relies on Polynomial Chaos (PC) expansions on each sides of the discontinuity curve leading to an averaged-PC representation of the forward model that allows efficient uncertainty quantification and propagation. The methodology is tested on synthetic examples of discontinuous data with adjustable sharpness and structure.
Felice, Antonio De [TPTP and NEP, The Institute for Fundamental Study, Naresuan University, Phitsanulok 65000 (Thailand); Tsujikawa, Shinji, E-mail: antoniod@nu.ac.th, E-mail: shinji@rs.kagu.tus.ac.jp [Department of Physics, Faculty of Science, Tokyo University of Science, 1-3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan)
2012-02-01T23:59:59.000Z
In the Horndeski's most general scalar-tensor theories with second-order field equations, we derive the conditions for the avoidance of ghosts and Laplacian instabilities associated with scalar, tensor, and vector perturbations in the presence of two perfect fluids on the flat Friedmann-Lemaître-Robertson-Walker (FLRW) background. Our general results are useful for the construction of theoretically consistent models of dark energy. We apply our formulas to extended Galileon models in which a tracker solution with an equation of state smaller than -1 is present. We clarify the allowed parameter space in which the ghosts and Laplacian instabilities are absent and we numerically confirm that such models are indeed cosmologically viable.
Van Gorder, Robert A., E-mail: rav@knights.ucf.edu [Department of Mathematics, University of Central Florida, Orlando, Florida 32816-1364 (United States)
2014-11-15T23:59:59.000Z
In R. A. Van Gorder, “General rotating quantum vortex filaments in the low-temperature Svistunov model of the local induction approximation,” Phys. Fluids 26, 065105 (2014) I discussed properties of generalized vortex filaments exhibiting purely rotational motion under the low-temperature Svistunov model of the local induction approximation. Such solutions are stationary in terms of translational motion. In the Comment [N. Hietala, “Comment on ‘General rotating quantum vortex filaments in the low-temperature Svistunov model of the local induction approximation’ [Phys. Fluids 26, 065105 (2014)],” Phys. Fluids 26, 119101 (2014)], the author criticizes my paper for not including translational motion (although it was clearly stated that the filament motion was assumed rotational). As it turns out, if one is interested in studying the geometric structure of solutions (which was the point of my paper), one obtains the needed qualitative results on the structure of such solutions by studying the purely rotational case. Nevertheless, in this Response I shall discuss the vortex filaments that have both rotational and translational motions. I then briefly discuss why one might want to study such generalized rotating filament solutions, in contrast to simple the standard helical or planar examples (which are really special cases). I also discuss how one can study the time evolution of filaments which exhibit more complicated dynamics than pure translation and rotation. Doing this, one can study non-stationary solutions which initially appear purely rotational and gradually display other dynamics as the filaments evolve.
Bill Jackson; Aldo Procacci; Alan D. Sokal
2014-12-02T23:59:59.000Z
We find zero-free regions in the complex plane at large |q| for the multivariate Tutte polynomial (also known in statistical mechanics as the Potts-model partition function) Z_G(q,w) of a graph G with general complex edge weights w = {w_e}. This generalizes a result of Sokal (cond-mat/9904146) that applies only within the complex antiferromagnetic regime |1+w_e| \\le 1. Our proof uses the polymer-gas representation of the multivariate Tutte polynomial together with the Penrose identity.
Scarlat, Raluca Olga
2012-01-01T23:59:59.000Z
natural circulation solar water heater. Energy Conversionas water circulation in solar water heaters 60 , and passivewater circulation in solar water heaters 60 , and passive
Do Coupled Climate Models Correctly SImulate the Upward Branch of the Deept Ocean Global Conveyor?
Sarmiento, Jorge L; Downes, Stephanie; Bianchi, Daniele
2013-01-17T23:59:59.000Z
The large-scale meridional overturning circulation (MOC) connects the deep ocean, a major reservoir of carbon, to the other components of the climate system and must therefore be accurately represented in Earth System Models. Our project aims to address the specific question of the pathways and mechanisms controlling the upwelling branch of the MOC, a subject of significant disagreement between models and observational syntheses, and among general circulation models. Observations of these pathways are limited, particularly in regions of complex hydrography such as the Southern Ocean. As such, we rely on models to examine theories of the overturning circulation, both physically and biogeochemically. This grant focused on a particular aspect of the meridional overturning circulation (MOC) where there is currently significant disagreement between models and observationally based analyses of the MOC, and amongst general circulation models. In particular, the research focused on addressing the following questions: 1. Where does the deep water that sinks in the polar regions rise to the surface? 2. What processes are responsible for this rise? 3. Do state-of-the-art coupled GCMs capture these processes? Our research had three key components: observational synthesis, model development and model analysis. In this final report we outline the key results from these areas of research for the 2007 to 2012 grant period. The research described here was carried out primarily by graduate student, Daniele Bianchi (now a Postdoc at McGill University, Canada), and Postdoc Stephanie Downes (now a Research Fellow at The Australian national University, Australia). Additional support was provided for programmers Jennifer Simeon as well as Rick Slater.
Estimates of the stratospheric residual circulation using the downward control principle
Rosenlof, K.H.; Holton, J.R. [Univ. of Washington, Seattle, WA (United States)
1993-06-20T23:59:59.000Z
The transformed Eulerian-mean momentum and continuity equations are used to calculate the residual mean meridional circulations for the lower stratosphere and troposphere. Momentum and temperature fluxes required for the computation are estimated from U.K. Meterological Office (UKMO) analyzed geopotential heights. National Center for Atmospheric Research (NCAR) CCM2 model output is used to assess the errors associated with the calculation. The model comparisons showed that the method works reasonably well for solstice seasons, but is inadequate for equinox seasons. In addition, it is found that some parameterization of gravity wave drag needs to be included with the planetary wave forcing to accurately estimate the residual mean circulation using this method. 24 refs., 10 figs., 5 tabs.
The Role of Eddy-Tansport in the Thermohaline Circulation
Dr. Paola Cessi
2011-11-17T23:59:59.000Z
Several research themes were developed during the course of this project. (1) Low-frequency oceanic varibility; (2) The role of eddies in the Antarctic Circumpolar Current (ACC) region; (3) Deep stratification and the overturning circulation. The key findings were as follows: (1) The stratification below the main thermocline (at about 500m) is determined in the circumpolar region and then communicated to the enclosed portions of the oceans through the overturning circulation. (2) An Atlantic pole-to-pole overturning circulation can be maintained with very small interior mixing as long as surface buoyancy values are shared between the northern North Atlantic and the ACC region.
On the World-wide Circulation of the Deeper Waters of the World Ocean
Reid, Joseph L
2009-01-01T23:59:59.000Z
circulation of the Pacific Ocean: Flow patterns, tracers,in preparing the figures. Fig. 1 Pacific Ocean winds Fig.2 Pacific Ocean circulation Fig. 4 Pacific Ocean potential
Circulating heat exchangers for oscillating wave engines and refrigerators
Swift, Gregory W.; Backhaus, Scott N.
2003-10-28T23:59:59.000Z
An oscillating-wave engine or refrigerator having a regenerator or a stack in which oscillating flow of a working gas occurs in a direction defined by an axis of a trunk of the engine or refrigerator, incorporates an improved heat exchanger. First and second connections branch from the trunk at locations along the axis in selected proximity to one end of the regenerator or stack, where the trunk extends in two directions from the locations of the connections. A circulating heat exchanger loop is connected to the first and second connections. At least one fluidic diode within the circulating heat exchanger loop produces a superimposed steady flow component and oscillating flow component of the working gas within the circulating heat exchanger loop. A local process fluid is in thermal contact with an outside portion of the circulating heat exchanger loop.
Parameters of Integral Circulant Graphs and Periodic Quantum Dynamics
Nitin Saxena; Simone Severini; Igor Shparlinski
2007-03-26T23:59:59.000Z
The intention of the paper is to move a step towards a classification of network topologies that exhibit periodic quantum dynamics. We show that the evolution of a quantum system, whose hamiltonian is identical to the adjacency matrix of a circulant graph, is periodic if and only if all eigenvalues of the graph are integers (that is, the graph is integral). Motivated by this observation, we focus on relevant properties of integral circulant graphs. Specifically, we bound the number of vertices of integral circulant graphs in terms of their degree, characterize bipartiteness and give exact bounds for their diameter. Additionally, we prove that circulant graphs with odd order do not allow perfect state transfer.
Improving Heating System Operations Using Water Re-Circulation
Li, F.; Han, J.
2006-01-01T23:59:59.000Z
In order to solve the imbalance problem of a heating system, brought about by consumer demand and regulation, and save the electricity energy consumed by a circulation pump, a water mixing and pressure difference control heating system is proposed...
Improving Heating System Operations Using Water Re-Circulation
Li, F.; Han, J.
2006-01-01T23:59:59.000Z
In order to solve the imbalance problem of a heating system, brought about by consumer demand and regulation, and save the electricity energy consumed by a circulation pump, a water mixing and pressure difference control heating system is proposed...
Gas phase hydrodynamics inside a circulating fluidized bed
Moran, James C. (James Christopher)
2001-01-01T23:59:59.000Z
Circulating Fluidized Beds (CFB's) offer many advantages over traditional pulverized coal burners in the power generation industry. They operate at lower temperatures, have better environmental emissions and better fuel ...
Circulation of autonomous agents in production and service networks
Floreano, Dario
Circulation of autonomous agents in production and service networks Olivier Gallay Ã, Max author. Tel.: +41216935817; fax: +41216933891. E-mail address: olivier.gallay@epfl.ch (O. Gallay). Int. J
On the circulation and stratification of the Weddell Gyre
Orsi, Alejandro H.
1990-01-01T23:59:59.000Z
on selected isopycnals. South of the eastward-flowing Antarctic Circumpolar Current, the Weddell Gyre is revealed as a weakly-sheared circulation elongated in the southwest-to-northeast direction. Southward penetration of Circumpolar Deep Water (CDW.... The moral support from my parents and brothers has been an invaluable constant during my years of study abroad. To them is this simple tribute. TABLE OF CONTENTS INTRODUCTION. 1. Circulation. 2. Water Masses. Page I 5 7 GEOSTROPHIC FLOW WATER...
McGillicuddy Jr., Dennis J.
Near-bottom circulation and dispersion of sediment containing Alexandrium fundyense cysts evaluates model near-bottom flow during storms, when sediment resuspension and redistribution are most a r t i c l e i n f o Available online 16 December 2013 Keywords: Sediment connectivity Near
Gurgel, Angelo C.
We develop a forward-looking version of the MIT Emissions Prediction and Policy Analysis (EPPA) model, and apply it to examine the economic implications of proposals in the U.S. Congress to limit greenhouse gas (GHG) ...
Gilman, Lindsey Anne
2014-01-01T23:59:59.000Z
Advanced modeling capabilities were developed for application to subcooled flow boiling through this work. The target was to introduce, and demonstrate, all necessary mechanisms required to accurately predict the temperature ...
February 2002 Modelling The Conveyor Belt Circulation using MICOM
Nadiga, Balasubramanya T. "Balu"
;Climatological SST, Zero flux over ice, Net heating of 17 W/m2 #12;Climatological SST, Zero flux over ice, Net
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.
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.
Zakirjon Kanokov; Juern W. P. Schmelzer; Avazbek K. Nasirov
2009-04-07T23:59:59.000Z
An analysis of a variety of existing experimental data leads to the conclusion on the existence of a resonance mechanism allowing weak magnetic fields to affect biological processes. These fields may either be static magnetic fields comparable in magnitude with the magnetic field of the earth or weak ultra-low frequency time-dependent fields. So far, a generally accepted theoretical model allowing one to understand the effect of magnetic and electric fields on biological processes is not available. By this reason, it is not clear which characteristics of the fields, like magnetic and electric field strength, frequency of change of the field, shape of the electromagnetic wave, the duration of the magnetic or electric influence or some particular combination of them, are responsible for the biological effect. In the present analysis it is shown that external time-independent magnetic fields may cause a resonance amplification of ionic electric currents in biological tissues and, in particular, in the vasculature system due to a Brownian motion of charges. These resonance electric currents may cause necrotic changes in the tissues or blood circulation and in this way significantly affect the biological organism. The magnitude of the magnetic fields leading to resonance effects is estimated, it is shown that it depends significantly on the radius of the blood capillaries.
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirt DocumentationSitesWeather6Environmental1 |MAgnEtProjectsÂ» General Recommendations General
Heermann, Dieter W.
parametrization for Bisphenol-A-Polycarbonate Klaus M. Zimmer, Andreas Linke and Dieter W. Heermann Institut fur of the monomer units. We apply the model to the special case of Bisphenol-A-Polycarbonate (BPA- PC) and present properties of polycarbonate systems. We will also present properties and e ciency considerations
Casey, James Elmer
1973-01-01T23:59:59.000Z
. Hypothetical Factor-Pactor Model indicating profit maximizing conditions with limited capital and with a variab1e input limitation 24 P2 units, then other inputs would be added until their marginal value poduct was equal to their price. This would...
Objective Our goal is to develop a modeling formalism for representing state and change of state. Approach We represent cyber systems as discrete mathematical objects interacting across hierarchically
Yang, Zhaoqing; Khangaonkar, Tarang
2010-11-19T23:59:59.000Z
Water circulation in Puget Sound, a large complex estuary system in the Pacific Northwest coastal ocean of the United States, is governed by multiple spatially and temporally varying forcings from tides, atmosphere (wind, heating/cooling, precipitation/evaporation, pressure), and river inflows. In addition, the hydrodynamic response is affected strongly by geomorphic features, such as fjord-like bathymetry and complex shoreline features, resulting in many distinguishing characteristics in its main and sub-basins. To better understand the details of circulation features in Puget Sound and to assist with proposed nearshore restoration actions for improving water quality and the ecological health of Puget Sound, a high-resolution (around 50 m in estuaries and tide flats) hydrodynamic model for the entire Puget Sound was needed. Here, a threedimensional circulation model of Puget Sound using an unstructured-grid finite volume coastal ocean model is presented. The model was constructed with sufficient resolution in the nearshore region to address the complex coastline, multi-tidal channels, and tide flats. Model open boundaries were extended to the entrance of the Strait of Juan de Fuca and the northern end of the Strait of Georgia to account for the influences of ocean water intrusion from the Strait of Juan de Fuca and the Fraser River plume from the Strait of Georgia, respectively. Comparisons of model results, observed data, and associated error statistics for tidal elevation, velocity, temperature, and salinity indicate that the model is capable of simulating the general circulation patterns on the scale of a large estuarine system as well as detailed hydrodynamics in the nearshore tide flats. Tidal characteristics, temperature/salinity stratification, mean circulation, and river plumes in estuaries with tide flats are discussed.
Colaiori, Francesca; Cuskley, Christine F; Loreto, Vittorio; Pugliese, Martina; Tria, Francesca
2014-01-01T23:59:59.000Z
Empirical evidence shows that the rate of irregular usage of English verbs exhibits discontinuity as a function of their frequency: the most frequent verbs tend to be totally irregular. We aim to qualitatively understand the origin of this feature by studying simple agent--based models of language dynamics, where each agent adopts an inflectional state for a verb and may change it upon interaction with other agents. At the same time, agents are replaced at some rate by new agents adopting the regular form. In models with only two inflectional states (regular and irregular), we observe that either all verbs regularize irrespective of their frequency, or a continuous transition occurs between a low frequency state where the lemma becomes fully regular, and a high frequency one where both forms coexist. Introducing a third (mixed) state, wherein agents may use either form, we find that a third, qualitatively different behavior may emerge, namely, a discontinuous transition in frequency. We introduce and solve an...
Van Gorder, Robert A., E-mail: rav@knights.ucf.edu [Department of Mathematics, University of Central Florida, Orlando, Florida 32816-1364 (United States)
2014-06-15T23:59:59.000Z
In his study of superfluid turbulence in the low-temperature limit, Svistunov [“Superfluid turbulence in the low-temperature limit,” Phys. Rev. B 52, 3647 (1995)] derived a Hamiltonian equation for the self-induced motion of a vortex filament. Under the local induction approximation (LIA), the Svistunov formulation is equivalent to a nonlinear dispersive partial differential equation. In this paper, we consider a family of rotating vortex filament solutions for the LIA reduction of the Svistunov formulation, which we refer to as the 2D LIA (since it permits a potential formulation in terms of two of the three Cartesian coordinates). This class of solutions holds the well-known Hasimoto-type planar vortex filament [H. Hasimoto, “Motion of a vortex filament and its relation to elastica,” J. Phys. Soc. Jpn. 31, 293 (1971)] as one reduction and helical solutions as another. More generally, we obtain solutions which are periodic in the space variable. A systematic analytical study of the behavior of such solutions is carried out. In the case where vortex filaments have small deviations from the axis of rotation, closed analytical forms of the filament solutions are given. A variety of numerical simulations are provided to demonstrate the wide range of rotating filament behaviors possible. Doing so, we are able to determine a number of vortex filament structures not previously studied. We find that the solution structure progresses from planar to helical, and then to more intricate and complex filament structures, possibly indicating the onset of superfluid turbulence.
images from 2011 and 2012 to define the near-global distribution of zonal winds and eddy momentum fluxes combined with the greater feature contrast in the northern hemisphere during the approach to spring equinox allow for better rejection of erroneous wind vectors, a more objective assessment at any latitude
Canuto, V
2015-01-01T23:59:59.000Z
This is an English translation of the Italian version of an encyclopedia chapter that appeared in the Italian Encyclopedia of the Physical Sciences, edited by Bruno Bertotti (1994). Following requests from colleagues we have decided to make it available to a more general readership. We present the motivation for constructing General Relativity, provide a short discussion of tensor algebra, and follow the set up of Einstein equations. We discuss briefly the initial value problem, the linear approximation and how should non gravitational physics be described in curved spacetime.
Methods of forming a fluidized bed of circulating particles
Marshall, Douglas W. (Blackfoot, ID)
2011-05-24T23:59:59.000Z
There is disclosed an apparatus for forming a fluidized bed of circulating particles. In an embodiment, the apparatus includes a bottom portion having a sidewall, the sidewall defining a curvilinear profile, and the bottom portion configured to contain a bed of particles; and a gas inlet configured to produce a column of gas to carry entrained particles therein. There is disclosed a method of forming a fluidized bed of circulating particles. In an embodiment, the method includes positioning particles within a bottom portion having a sidewall, the sidewall defining a curvilinear profile; producing a column of gas directed upwardly through a gas inlet; carrying entrained particles in the column of gas to produce a fountain of particles over the fluidized bed of circulating particles and subside in the particle bed until being directed inwardly into the column of gas within the curvilinear profile.
Circulating Fluidized Bed Boilers Market Trends | OpenEI Community
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Recent progress on Exxon's circulating zinc bromine battery system
Bellows, R.J.
1981-01-01T23:59:59.000Z
The design, performance, and factory cost of Exxon's circulating zinc bromine batteries are described. The Exxon system has demonstrated stable performance in scale-ups to 3- and 10-kWh sub-modules. Cost studies based on recently demonstrated extrusion and injection molding techniques, have shown that this battery, with plastic electrodes, bipolar stacks, Br/sub 2/ complexation, and circulating electrolytes, could be produced (20 kWh units, 100,000 units/year) at a factory cost of $28/kWh (excluding R.O.I., and various indirect overheads).
Sponaugle, Su
model using a mesoscale-resolving ocean general circulation model (OGCM). Al- though the simulationsare
Amy Honchar
2012-11-12T23:59:59.000Z
The contribution of funds from DOE supported publication costs of a special issue of Deep Sea Research arising from presentations at the First U.S. Atlantic Meridional Overturning Circulation (AMOC) Meeting held 4-6 May, 2009 to review the US implementation plan and its coordination with other monitoring activities. The special issue includes a total of 16 papers, including publications from three DOE-supported investigators (ie Sevellec, F., and A.V. Fedorov; Hu et. al., and Wan et. al.,). The special issue addresses DOE interests in understanding and simulation/modeling of abrupt climate change.
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David A. Randall; Marat Khairoutdinov
2007-12-14T23:59:59.000Z
The Colorado State University (CSU) Multi-scale Modeling Framework (MMF) is a new type of general circulation model (GCM) that replaces the conventional parameterizations of convection, clouds and boundary layer with a cloud-resolving model (CRM) embedded into each grid column. The MMF that we have been working with is a “super-parameterized” version of the Community Atmosphere Model (CAM). As reported in the publications listed below, we have done extensive work with the model. We have explored the MMF’s performance in several studies, including an AMIP run and a CAPT test, and we have applied the MMF to an analysis of climate sensitivity.
SURFACE CIRCULATION AND VENTILATION Lynne D. Talley(1)
Talley, Lynne D.
SURFACE CIRCULATION AND VENTILATION Lynne D. Talley(1) , Rana Fine(2) , Rick Lumpkin (3) , Nikolai by high frequency radars. Ventilation and upwelling processes connect the surface layer and underlying quantitative information on formation rates and residence times, and compelling evidence of decadal ventilation
UNCORRECTEDPROOF Effect of channel bifurcation on residual estuarine circulation
Voulgaris, George
western channel. This is the result of the fact that the magnitude of residual flow scales with the water throughout the water column of the channel while in the adjacent shoals the residual flow is directedUNCORRECTEDPROOF Effect of channel bifurcation on residual estuarine circulation: Winyah Bay, South
Decadal variability of the Atlantic Meridional Overturning Circulation
Buckley, Martha Weaver
2011-01-01T23:59:59.000Z
In the mean, the Atlantic Ocean transports 1 to 1.5 PW of heat northward, and estimates suggest that 60% of this heat transport is associated with a circulation that reaches the cold waters of the abyss. Due to the role ...
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Benchmarking assessment of RELAP5/MOD3 for the low flow and natural circulation experiment
Martin, R.P. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Taylor, B.K. [Westinghouse Savannah River Co., Aiken, SC (United States)
1992-11-01T23:59:59.000Z
The RELAP5/MOD3 code was assessed against experimental thermal hydraulics data for a 12.5 foot test section comprised of two vertical concentric tubes with water flowing upward in the tubes. The inner tubewas stainless steel and uniformly heated. ne outer tube was transparent polycarbonate (lexan) and unheated. The experimental procedure incorporated a test matrix of 24 tests to address single- and two-phase flow, forced and natural circulation flow and heated and unheated fluid. The tests were conducted at system pressures of 14.7 and 17.0 psia. Nine of the tests representing the full range of test conditions were analyzed using RELAP5/MOD3. RELAP5/MOD3 analysis of the tests yielded general agreement with experiment with regard to the prediction of forced flow and natural circulation trends. However, a number of deficiencies were observed in the RELAP5/MOD3 treatment and these, along with recommendations for their resolution, are described in the paper.
Benchmarking assessment of RELAP5/MOD3 for the low flow and natural circulation experiment
Martin, R.P. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Taylor, B.K. (Westinghouse Savannah River Co., Aiken, SC (United States))
1992-01-01T23:59:59.000Z
The RELAP5/MOD3 code was assessed against experimental thermal hydraulics data for a 12.5 foot test section comprised of two vertical concentric tubes with water flowing upward in the tubes. The inner tubewas stainless steel and uniformly heated. ne outer tube was transparent polycarbonate (lexan) and unheated. The experimental procedure incorporated a test matrix of 24 tests to address single- and two-phase flow, forced and natural circulation flow and heated and unheated fluid. The tests were conducted at system pressures of 14.7 and 17.0 psia. Nine of the tests representing the full range of test conditions were analyzed using RELAP5/MOD3. RELAP5/MOD3 analysis of the tests yielded general agreement with experiment with regard to the prediction of forced flow and natural circulation trends. However, a number of deficiencies were observed in the RELAP5/MOD3 treatment and these, along with recommendations for their resolution, are described in the paper.
Pandoe, Wahyu Widodo
2004-09-30T23:59:59.000Z
provides a basis for determining how the water circulation three-dimensionally controls the hydrodynamics of the system and ultimately transports the suspended and soluble materials due to combined currents and waves. A three-dimensional circulation model...
DRILLING MACHINES GENERAL INFORMATION
Gellman, Andrew J.
TC 9-524 Chapter 4 DRILLING MACHINES GENERAL INFORMATION PURPOSE This chapter contains basic information pertaining to drilling machines. A drilling machine comes in many shapes and sizes, from small hand-held power drills to bench mounted and finally floor-mounted models. They can perform operations
The circulation of the ocean is usually divided into two parts, a wind-driven circulation that
measurements show that the thermohaline circulation turns over all the deep water in the ocean every 600 years, in the formation of new deep water in the North Atlantic and the Southern Ocean. Large volumes of cold polar water occurs and how upwelled deep water returns to the areas of deep-water formation. The main new development
Marshall, John C.
A series of coupled atmosphere–ocean–ice aquaplanet experiments is described in which topological constraints on ocean circulation are introduced to study the role of ocean circulation on the mean climate of the coupled ...
Intermediate- to Deep-Water Circulation Changes on Short and Long Time Scales
Murphy, Daniel Patrick
2012-07-16T23:59:59.000Z
Oceanic circulation remains one of the poorly understood elements of the global climate system, despite its importance to planetary heat redistribution and carbon cycling. The nature of deep-water formation and circulation in ancient oceans are even...
Experimental Study of the Circulation Air Volume of Recirculation Evaporative Cooling
Xiong, J.; Liu, Z.; Wang, C.; Chen, G.
2006-01-01T23:59:59.000Z
This paper introduces the technology of re-circulation evaporative cooling (REC), which uses a portion of supply air as secondary air to make cool water used to indirectly cool outside air through a heat exchanger. The circulation volume...
Experimental Study of the Circulation Air Volume of Recirculation Evaporative Cooling
Xiong, J.; Liu, Z.; Wang, C.; Chen, G.
2006-01-01T23:59:59.000Z
This paper introduces the technology of re-circulation evaporative cooling (REC), which uses a portion of supply air as secondary air to make cool water used to indirectly cool outside air through a heat exchanger. The circulation volume...
MFIX simulation of NETL/PSRI challenge problem of circulating fluidized bed
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Li, Tingwen; Dietiker, Jean-Francois; Shahnam, Mehrdad
2012-12-01T23:59:59.000Z
In this paper, numerical simulations of NETL/PSRI challenge problem of circulating fluidized bed (CFB) using the open-source code Multiphase Flow with Interphase eXchange (MFIX) are reported. Two rounds of simulation results are reported including the first-round blind test and the second-round modeling refinement. Three-dimensional high fidelity simulations are conducted to model a 12-inch diameter pilot-scale CFB riser. Detailed comparisons between numerical results and experimental data are made with respect to axial pressure gradient profile, radial profiles of solids velocity and solids mass flux along different radial directions at various elevations for operating conditions covering different fluidization regimes. Overall, the numerical results show that CFD can predict the complex gas–solids flow behavior in the CFB riser reasonably well. In addition, lessons learnt from modeling this challenge problem are presented.
MFIX simulation of NETL/PSRI challenge problem of circulating fluidized bed
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Li, Tingwen; Dietiker, Jean-François; Shahnam, Mehrdad
2012-12-01T23:59:59.000Z
In this paper, numerical simulations of NETL/PSRI challenge problem of circulating fluidized bed (CFB) using the open-source code Multiphase Flow with Interphase eXchange (MFIX) are reported. Two rounds of simulation results are reported including the first-round blind test and the second-round modeling refinement. Three-dimensional high fidelity simulations are conducted to model a 12-inch diameter pilot-scale CFB riser. Detailed comparisons between numerical results and experimental data are made with respect to axial pressure gradient profile, radial profiles of solids velocity and solids mass flux along different radial directions at various elevations for operating conditions covering different fluidization regimes. Overall, the numericalmore »results show that CFD can predict the complex gas–solids flow behavior in the CFB riser reasonably well. In addition, lessons learnt from modeling this challenge problem are presented.« less
Physiological relevance of the changes in hemodynamics for circulating blood cells in
103 Chapter 5 Physiological relevance of the changes in hemodynamics for circulating blood cells that these changes in the mechanical stimuli might have on the activation state of circulating blood cells have never the magnitude and duration of the shear stresses acting on blood cells circulating inside AAAs
Short-circuiting of the overturning circulation in the Antarctic Circumpolar Current
Miami, University of
LETTERS Short-circuiting of the overturning circulation in the Antarctic Circumpolar Current flows over complex ocean-floor topography, giving rise to a short circuit of the overturning circulation. Mixing processes in the Antarctic Circumpolar Current are key to this circulation, because they con- trol
Traditional and novel approaches to palaeoclimate modelling
Crucifix, Michel
2012-01-01T23:59:59.000Z
Palaeoclimate archives contain information on climate variability, trends and mechanisms. Models are developed to explain observations and predict the response of the climate system to perturbations, in particular perturbations associated with the anthropogenic influence. Here, we review three classical frameworks of climate modelling: conceptual, simulator-based (including general circulation models and Earth system models of intermediate complexity), and statistical. The conceptual framework aims at a parsimonious representation of a given climate phenomenon; the simulator-based framework connects physical and biogeochemical principles with phenomena at different spatial and temporal scales; and statistical modelling is a framework for inference from observations, given hypotheses on systematic and random effects. Recently, solutions have been proposed in the literature to combine these frameworks, and new concepts have emerged: the emulator (a statistical, computing efficient surrogate for the simulator) a...
Mueller, Bernhard; Janka, Hans-Thomas; Marek, Andreas, E-mail: bjmuellr@mpa-garching.mpg.de, E-mail: thj@mpa-garching.mpg.de [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany)
2012-09-01T23:59:59.000Z
We present the first two-dimensional general relativistic (GR) simulations of stellar core collapse and explosion with the COCONUT hydrodynamics code in combination with the VERTEX solver for energy-dependent, three-flavor neutrino transport, using the extended conformal flatness condition for approximating the space-time metric and a ray-by-ray-plus ansatz to tackle the multi-dimensionality of the transport. For both of the investigated 11.2 and 15 M{sub Sun} progenitors we obtain successful, though seemingly marginal, neutrino-driven supernova explosions. This outcome and the time evolution of the models basically agree with results previously obtained with the PROMETHEUS hydro solver including an approximative treatment of relativistic effects by a modified Newtonian potential. However, GR models exhibit subtle differences in the neutrinospheric conditions compared with Newtonian and pseudo-Newtonian simulations. These differences lead to significantly higher luminosities and mean energies of the radiated electron neutrinos and antineutrinos and therefore to larger energy-deposition rates and heating efficiencies in the gain layer with favorable consequences for strong nonradial mass motions and ultimately for an explosion. Moreover, energy transfer to the stellar medium around the neutrinospheres through nucleon recoil in scattering reactions of heavy-lepton neutrinos also enhances the mentioned effects. Together with previous pseudo-Newtonian models, the presented relativistic calculations suggest that the treatment of gravity and energy-exchanging neutrino interactions can make differences of even 50%-100% in some quantities and is likely to contribute to a finally successful explosion mechanism on no minor level than hydrodynamical differences between different dimensions.
Mathematical Modeling Arnold Neumaier
Neumaier, Arnold
· Blood circulation models 4 #12;Meteorology · Weather prediction · Climate prediction (global warming (genetic variability) Chemical engineering · Chemical equilibrium · Planning of production units Chemistry recognition · Face recognition Economics · Labor data analysis Electrical engineering · Stability of electric
Apparatus and method for determining solids circulation rate
Ludlow, J. Christopher (Morgantown, WV); Spenik, James L. (Morgantown, WV)
2012-02-14T23:59:59.000Z
The invention relates to a method of determining bed velocity and solids circulation rate in a standpipe experiencing a moving packed bed flow, such as the in the standpipe section of a circulating bed fluidized reactor The method utilizes in-situ measurement of differential pressure over known axial lengths of the standpipe in conjunction with in-situ gas velocity measurement for a novel application of Ergun equations allowing determination of standpipe void fraction and moving packed bed velocity. The method takes advantage of the moving packed bed property of constant void fraction in order to integrate measured parameters into simultaneous solution of Ergun-based equations and conservation of mass equations across multiple sections of the standpipe.
Polymer grouts for plugging lost circulation in geothermal wells.
Galbreath, D. (Green Mountain International, Waynesvile, NC); Mansure, Arthur James; Bauer, Stephen J.
2004-12-01T23:59:59.000Z
We have concluded a laboratory study to evaluate the survival potential of polymeric materials used for lost circulation plugs in geothermal wells. We learned early in the study that these materials were susceptible to hydrolysis. Through a systematic program in which many potential chemical combinations were evaluated, polymers were developed which tolerated hydrolysis for eight weeks at 500 F. The polymers also met material, handling, cost, and emplacement criteria. This screening process identified the most promising materials. A benefit of this work is that the components of the polymers developed can be mixed at the surface and pumped downhole through a single hose. Further strength testing is required to determine precisely the maximum temperature at which extrusion through fractures or voids causes failure of the lost circulation plug.
Circulant conference matrices for new complex Hadamard matrices
Petre Dita
2011-07-07T23:59:59.000Z
The circulant real and complex matrices are used to find new real and complex conference matrices. With them we construct Sylvester inverse orthogonal matrices by doubling the size of inverse complex conference matrices. When the free parameters take values on the unit circle the inverse orthogonal matrices transform into complex Hadamard matrices. The method is used for $n=6$ conference matrices and in this way we find new parametrisations of Hadamard matrices for dimension $ n=12$.
On the circulation and stratification of the Weddell Gyre
Orsi, Alejandro H.
1990-01-01T23:59:59.000Z
, and probably also in deep water formation over the continental margins of the eastern sector. Within the ACC the upper portion of the CDW is characterized by a temperature maximum (8-max) and oxygen minimum (~-min). The lower part of the CDW (LCDW... on selected isopycnals. South of the eastward-flowing Antarctic Circumpolar Current, the Weddell Gyre is revealed as a weakly-sheared circulation elongated in the southwest-to-northeast direction. Southward penetration of Circumpolar Deep Water (CDW...
NUCLA Circulating Atmospheric Fluidized Bed Demonstration Project. 1990 Annual report
Not Available
1992-02-01T23:59:59.000Z
The objective of this DOE Cooperative Agreement is to conduct a cost-shared clean coal technology project to demonstrate the feasibility of circulating fluidized bed combustion technology and to evaluate economic, environmental, and operational benefits of CFB steam generators on a utility scale. At the conclusion of the Phase 2 program, testing related to satisfying these objectives was completed. Data analysis and reporting are scheduled for completion by October 1991. (VC)
Gidaspow, D.; Ettehadieh, B.; Lin, C.; Goyal, A.; Lyczkowski, R.W.
1980-01-01T23:59:59.000Z
The object of this investigation was to develop an experimentally verified hydrodynamic model to predict solids circulation around a jet in a fluidized bed gasifier. Hydrodynamic models of fluidization use the principles of conservation of mass, momentum and energy. To account for unequal velocities of solid and fluid phases, separate phase momentum balances are developed. Other fluid bed models used in the scale-up of gasifiers do not employ the principles of conservation of momentum. Therefore, these models cannot predict fluid and particle motion. In such models solids mixing is described by means of empirical transfer coefficients. A two dimensional unsteady state computer code was developed to give gas and solid velocities, void fractions and pressure in a fluid bed with a jet. The growth, propagation and collapse of bubbles was calculated. Time-averaged void fractions were calculated that showed an agreement with void fractions measured with a gamma ray densitometer. Calculated gas and solid velocities in the jet appeared to be reasonable. Pressure and void oscillations also appear to be reasonable. A simple analytical formula for the rate of solids circulation was developed from the equations of change. It agrees with Westinghouse fluidization data in a bed with a draft tube. One dimensional hydrodynamic models were applied to modeling of entrained-flow coal gasification reactors and compared with data. Further development of the hydrodynamic models should make the scale-up and simulation of fluidized bed reactors a reality.
Deterministic treatment of model error in geophysical data assimilation
Carrassi, Alberto
2015-01-01T23:59:59.000Z
This chapter describes a novel approach for the treatment of model error in geophysical data assimilation. In this method, model error is treated as a deterministic process fully correlated in time. This allows for the derivation of the evolution equations for the relevant moments of the model error statistics required in data assimilation procedures, along with an approximation suitable for application to large numerical models typical of environmental science. In this contribution we first derive the equations for the model error dynamics in the general case, and then for the particular situation of parametric error. We show how this deterministic description of the model error can be incorporated in sequential and variational data assimilation procedures. A numerical comparison with standard methods is given using low-order dynamical systems, prototypes of atmospheric circulation, and a realistic soil model. The deterministic approach proves to be very competitive with only minor additional computational c...
Fedorov, Alexey [Yale University] [Yale University
2013-11-23T23:59:59.000Z
The central goal of this research project is to understand the properties of the ocean meridional overturning circulation (MOC) – a topic critical for understanding climate variability and stability on a variety of timescales (from decadal to centennial and longer). Specifically, we have explored various factors that control the MOC stability and decadal variability in the Atlantic and the ocean thermal structure in general, including the possibility abrupt climate change. We have also continued efforts on improving the performance of coupled ocean-atmosphere GCMs.
Fan, Jiwen; Rosenfeld, Daniel; Ding, Yanni; Leung, Lai-Yung R.; Li, Zhanqing
2012-05-10T23:59:59.000Z
Aerosol indirect effects, i.e., the interactions of aerosols with clouds by serving as cloud condensation nuclei (CCN) or ice nuclei (IN), constitute the largest uncertainty in climate forcing and projection. Previous IPCC reported aerosol indirect forcing is negative, which does not account for aerosol-convective cloud interactions because the complex processes involved are poorly understood and represented in climate models. Here we report that aerosol indirect effect on deep convective cloud systems can lead to enhanced regional convergence and a strong top-of atmosphere (TOA) warming. Aerosol invigoration effect on convection can result in a strong radiative warming in the atmosphere (+5.6 W m-2) due to strong night-time warming, a lofted latent heating, and a reduced diurnal temperature difference, all of which could remarkably impact regional circulation and modify weather systems. We further elucidated how aerosols change convective intensity, diabatic heating, and regional circulation under different environmental conditions and concluded that wind shear and cloud base temperature play key roles in determining the significance of aerosol invigoration effect for convective systems.
Follows, Mick
Impact of circulation on export production, dissolved organic matter, and dissolved oxygen; published 8 August 2007. [1] Results are presented of export production, dissolved organic matter (DOM ± 6 Pg C yrÀ1 . Model means of globally averaged particle export, the fraction of total export
A toolkit for building earth system models
Foster, I.
1993-03-01T23:59:59.000Z
An earth system model is a computer code designed to simulate the interrelated processes that determine the earth's weather and climate, such as atmospheric circulation, atmospheric physics, atmospheric chemistry, oceanic circulation, and biosphere. I propose a toolkit that would support a modular, or object-oriented, approach to the implementation of such models.
A toolkit for building earth system models
Foster, I.
1993-03-01T23:59:59.000Z
An earth system model is a computer code designed to simulate the interrelated processes that determine the earth`s weather and climate, such as atmospheric circulation, atmospheric physics, atmospheric chemistry, oceanic circulation, and biosphere. I propose a toolkit that would support a modular, or object-oriented, approach to the implementation of such models.
Circulating Fluidized Bed Boilers Market Analysis | OpenEI Community
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 Data Center Home Page on DeliciousPlasmaP aCentrotherm Photovoltaics AG Jump to:Chestnut RidgeCima NanoTech Jump to:CincoCirculating Fluidized
Circulating Fluidized Bed Boilers Market Size | OpenEI Community
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 Data Center Home Page on DeliciousPlasmaP aCentrotherm Photovoltaics AG Jump to:Chestnut RidgeCima NanoTech Jump to:CincoCirculating
Broader source: Energy.gov [DOE]
The Assistant General Counsel for General Law is responsible for providing legal review and general legal services to DOE with regard to matters involving: fiscal, personnel, labor relations,...
Blei, David M.
2011-01-01T23:59:59.000Z
characterizes the deviation of the response from its conditional mean. The simplest example is linear regression. Generalized linear models (GLMs) extend linear regression to many types of response variables (Mc a linear function; a non-linear function may be applied to the output of the linear function, but only one
CFD analyses of natural circulation in the air-cooled reactor cavity cooling system
Hu, R. [Nuclear Engineering Division, Argonne National Laboratory, Argonne IL (United States); Pointer, W. D. [Reactor and Nuclear Systems Division, Oak Ridge National Laboratory, Oak Ridge TN (United States)
2013-07-01T23:59:59.000Z
The Natural Convection Shutdown Heat Removal Test Facility (NSTF) is currently being built at Argonne National Laboratory, to evaluate the feasibility of the passive Reactor Cavity Cooling System (RCCS) for Next Generation Nuclear Plant (NGNP). CFD simulations have been applied to evaluate the NSTF and NGNP RCCS designs. However, previous simulations found that convergence was very difficult to achieve in simulating the complex natural circulation. To resolve the convergence issue and increase the confidence of the CFD simulation results, additional CFD simulations were conducted using a more detailed mesh and a different solution scheme. It is found that, with the use of coupled flow and coupled energy models, the convergence can be greatly improved. Furthermore, the effects of convection in the cavity and the effects of the uncertainty in solid surface emissivity are also investigated. (authors)
Regional Climate Modeling: Progress, Challenges, and Prospects
Wang, Yuqing; Leung, Lai R.; McGregor, John L.; Lee, Dong-Kyou; Wang, Wei-Chyung; Ding, Yihui; Kimura, Fujio
2004-12-01T23:59:59.000Z
Regional climate modeling with regional climate models (RCMs) has matured over the past decade and allows for meaningful utilization in a broad spectrum of applications. In this paper, latest progresses in regional climate modeling studies are reviewed, including RCM development, applications of RCMs to dynamical downscaling for climate change assessment, seasonal climate predictions and climate process studies, and the study of regional climate predictability. Challenges and potential directions of future research in this important area are discussed, with the focus on those to which less attention has been given previously, such as the importance of ensemble simulations, further development and improvement of regional climate modeling approach, modeling extreme climate events and sub-daily variation of clouds and precipitation, model evaluation and diagnostics, applications of RCMs to climate process studies and seasonal predictions, and development of regional earth system models. It is believed that with both the demonstrated credibility of RCMs’ capability in reproducing not only monthly to seasonal mean climate and interannual variability but also the extreme climate events when driven by good quality reanalysis and the continuous improvements in the skill of global general circulation models (GCMs) in simulating large-scale atmospheric circulation, regional climate modeling will remain an important dynamical downscaling tool for providing the needed information for assessing climate change impacts and seasonal climate predictions, and a powerful tool for improving our understanding of regional climate processes. An internationally coordinated effort can be developed with different focuses by different groups to advance regional climate modeling studies. It is also recognized that since the final quality of the results from nested RCMs depends in part on the realism of the large-scale forcing provided by GCMs, the reduction of errors and improvement in physics parameterizations in both GCMs and RCMs remain a priority for climate modeling community.
General Relativistic Radiative Transfer
S. Knop; P. H. Hauschildt; E. Baron
2006-11-30T23:59:59.000Z
We present a general method to calculate radiative transfer including scattering in the continuum as well as in lines in spherically symmetric systems that are influenced by the effects of general relativity (GR). We utilize a comoving wavelength ansatz that allows to resolve spectral lines throughout the atmosphere. The used numerical solution is an operator splitting (OS) technique that uses a characteristic formal solution. The bending of photon paths and the wavelength shifts due to the effects of GR are fully taken into account, as is the treatment of image generation in a curved spacetime. We describe the algorithm we use and demonstrate the effects of GR on the radiative transport of a two level atom line in a neutron star like atmosphere for various combinations of continuous and line scattering coefficients. In addition, we present grey continuum models and discuss the effects of different scattering albedos on the emergent spectra and the determination of effective temperatures and radii of neutron star atmospheres.
Wang, Zhengyuan
Intestinal stem cells play a pivotal role in the epithelial tissue renewal, homeostasis and cancer development. The lack of a general marker for intestinal stem cells across species has hampered analysis of stem cell number ...
Generalized Dirac operators and superconnections
G. Roepstorff; Ch. Vehns
1999-11-04T23:59:59.000Z
Motivated by the supersymmetric version of Dirac's theory, chiral models in field theory, and the quest of a geometric fundament for the Standard Model, we describe an approach to the differential geometry of vector bundles on (semi)-Riemannian manifolds based on the concepts of superspaces, superalgebras, superconnections, and generalized Dirac operators. In doing so we stay within the realm of commutative geometry.
Global impact of smoke aerosols from landscape fires on climate and the Hadley circulation
Tosca, M. G; Randerson, J. T; Zender, C. S
2013-01-01T23:59:59.000Z
of biomass burn- ing aerosol on the monsoon circulationA. , and Rudich, Y. : Aerosol invigoration and restructuring2011. Albrecht, B. A. : Aerosols, cloud microphysics, and
Estimating the solar meridional circulation by normal mode decomposition
Lars Krieger; Markus Roth; Oskar von der Luehe
2008-11-05T23:59:59.000Z
The objective of this article is to use Fourier-Hankel decomposition as suggested earlier by Braun & Fan (1998) to estimate the integrated horizontal meridional flow velocity as a function of mode penetration depth, and to find ways of potentially improve this technique. We use a time series of 43200 (30 days) consecutive full-disk Dopplergrams obtained by the MDI (Michelson Doppler Imager) instrument aboard the SOHO (Solar Heliospheric Observatory) spacecraft in April 1999. We find averaged meridional flow estimates of 15 m/s for modes with a penetration depth in the upper 20 Mm of the solar convection zone. This reproduces the results of the earlier investigations. Moreover we conclude that this method has the potential to become a new technique to measure the meridional circulation in the deep convection zone, if some improvements will be applied.
Doppler Signatures of the Atmospheric Circulation on Hot Jupiters
Showman, Adam P; Lewis, Nikole K; Shabram, Megan
2013-01-01T23:59:59.000Z
The meteorology of hot Jupiters has been characterized primarily with thermal measurements, but recent observations suggest the possibility of directly detecting the winds by observing the Doppler shift of spectral lines seen during transit. Motivated by these observations, we show how Doppler measurements can place powerful constraints on the meteorology. We show that the atmospheric circulation--and Doppler signature--of hot Jupiters splits into two regimes. Under weak stellar insolation, the day-night thermal forcing generates fast zonal jet streams from the interaction of atmospheric waves with the mean flow. In this regime, air along the terminator (as seen during transit) flows toward Earth in some regions and away from Earth in others, leading to a Doppler signature exhibiting superposed blue- and redshifted components. Under intense stellar insolation, however, the strong thermal forcing damps these planetary-scale waves, inhibiting their ability to generate jets. Strong frictional drag likewise damps...
Nucla circulating atmospheric fluidized bed demonstration project. Final report
Not Available
1991-10-01T23:59:59.000Z
Colorado-Ute Electric Association began a study to evaluate options for upgrading and extending the life of its Nucla power station in 1982. Located in southwestern Colorado near the town of Nucla, this station was commissioned in 1959 with a local bituminous coal as its design fuel for three identical stoker-fired units, each rated at 12.6 MW(e). Poor station efficiency, high fuel costs, and spiraling boiler maintenance costs forced the Nucla Station into low priority in the CUEA dispatch order as early as 1981. Among the options CUEA considered was to serve as a host utility to demonstrate Atmospheric Fluidized Bed Combustion (AFBC) technology. The anticipated environmental benefits and apparent attractive economics of a circulating AFBC led to Colorado-Ute`s decision to proceed with the design and construction of a demonstration project in 1984 at the Nucla facility.
Options for Cryogenic Load Cooling with Forced Flow Helium Circulation
Peter Knudsen, Venkatarao Ganni, Roberto Than
2012-06-01T23:59:59.000Z
Cryogenic pumps designed to circulate super-critical helium are commonly deemed necessary in many super-conducting magnet and other cooling applications. Acknowledging that these pumps are often located at the coldest temperature levels, their use introduces risks associated with the reliability of additional rotating machinery and an additional load on the refrigeration system. However, as it has been successfully demonstrated, this objective can be accomplished without using these pumps by the refrigeration system, resulting in lower system input power and improved reliability to the overall cryogenic system operations. In this paper we examine some trade-offs between using these pumps vs. using the refrigeration system directly with examples of processes that have used these concepts successfully and eliminated using such pumps
PPPL and General Atomics scientists make breakthrough in understanding...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
The left image models the response that suppressed the ELMs while the right image shows a response that was ineffective. Simulation by General Atomics. Researchers from General...
Entanglement Entropy of the Early Universe in Generalized Chaplygin...
Office of Scientific and Technical Information (OSTI)
Entanglement Entropy of the Early Universe in Generalized Chaplygin Gas Model Citation Details In-Document Search Title: Entanglement Entropy of the Early Universe in Generalized...
Mesoscale circulations and atmospheric CO2 variations in the Tapajos Region, Para, Brazil
Collett Jr., Jeffrey L.
Mesoscale circulations and atmospheric CO2 variations in the Tapajo´s Region, Para´, Brazil Lixin; published 2 November 2005. [1] We have investigated mesoscale circulations and atmospheric CO2 variations over a heterogeneous landscape of forests, pastures, and large rivers during the Santare´m Mesoscale
1 Drivers of the projected changes to the Pacific Ocean 2 equatorial circulation
Paris-Sud XI, Université de
1 Drivers of the projected changes to the Pacific Ocean 2 equatorial circulation 3 A. Sen Gupta,1 A), 29 Drivers of the projected changes to the Pacific Ocean equatorial 30 circulation, Geophys. Res. Lett., 39, LXXXXX, doi:10.1029/ 31 2012GL051447. 32 1. Introduction 33 [2] The equatorial Pacific Ocean
Thomas, Debbie
circulation in a greenhouse world Deborah J. Thomas and Mitchell Lyle Department of Oceanography, Texas A Ocean likely exerted the greatest marine influence on climate during the greenhouse interval and implications for thermohaline circulation in a greenhouse world, Geochem. Geophys. Geosyst., 9, Q02002, doi:10
Wind- and Buoyancy-modulated Along-shore Circulation over the Texas-Louisiana Shelf
Zhang, Zhaoru
2013-07-22T23:59:59.000Z
Numerical experiments are used to study the wind- and buoyancy-modulated along-shore circulation over the Texas-Louisiana continental shelf inshore of 50-m water depth. Most attention is given to circulation in the non-summer flow regime. A major...
Vallis, Geoff
A Theory of Deep Stratification and Overturning Circulation in the Ocean MAXIM NIKURASHIN overturning circulation in an idealized single-basin ocean with a circumpolar channel is presented. The theory; and consistently accounts for the interaction between the circumpolar channel and the rest of the ocean. The theory
Wind- and Buoyancy-modulated Along-shore Circulation over the Texas-Louisiana Shelf
Zhang, Zhaoru
2013-07-22T23:59:59.000Z
Numerical experiments are used to study the wind- and buoyancy-modulated along-shore circulation over the Texas-Louisiana continental shelf inshore of 50-m water depth. Most attention is given to circulation in the non-summer flow regime. A major...
Control of the ocean circulation by boundaries and topography P.B. Rhines
energy in the ocean circulation is dominated by boundary currents, zonal jets and mesoscale eddies and jet-like zonal currents dominate the kinetic energy of the world ocean. They are key features of bothControl of the ocean circulation by boundaries and topography P.B. Rhines University of Washington
Author's personal copy Sensitivity of the Atlantic Ocean circulation to a hydraulic overflow
Levermann, Anders
Author's personal copy Sensitivity of the Atlantic Ocean circulation to a hydraulic overflow the explicit representation of the overflows using a parameterisation by hydraulic constraints and compare circulation (AMOC) (Redler and Böning, 1997; Kuhlbrodt et al., 2007). The potential energy stored in the dense
Aerosol specification in single-column Community Atmosphere Model version 5
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Lebassi-Habtezion, B.; Caldwell, P. M.
2015-03-27T23:59:59.000Z
Single-column model (SCM) capability is an important tool for general circulation model development. In this study, the SCM mode of version 5 of the Community Atmosphere Model (CAM5) is shown to handle aerosol initialization and advection improperly, resulting in aerosol, cloud-droplet, and ice crystal concentrations which are typically much lower than observed or simulated by CAM5 in global mode. This deficiency has a major impact on stratiform cloud simulations but has little impact on convective case studies because aerosol is currently not used by CAM5 convective schemes and convective cases are typically longer in duration (so initialization is less important).more »By imposing fixed aerosol or cloud-droplet and crystal number concentrations, the aerosol issues described above can be avoided. Sensitivity studies using these idealizations suggest that the Meyers et al. (1992) ice nucleation scheme prevents mixed-phase cloud from existing by producing too many ice crystals. Microphysics is shown to strongly deplete cloud water in stratiform cases, indicating problems with sequential splitting in CAM5 and the need for careful interpretation of output from sequentially split climate models. Droplet concentration in the general circulation model (GCM) version of CAM5 is also shown to be far too low (~ 25 cm?3) at the southern Great Plains (SGP) Atmospheric Radiation Measurement (ARM) site.« less
Quantum Mechanics and the Generalized Uncertainty Principle
Jang Young Bang; Micheal S. Berger
2006-11-30T23:59:59.000Z
The generalized uncertainty principle has been described as a general consequence of incorporating a minimal length from a theory of quantum gravity. We consider a simple quantum mechanical model where the operator corresponding to position has discrete eigenvalues and show how the generalized uncertainty principle results for minimum uncertainty wave packets.
Graves, S.L.; Beavers, W.M.; Niederhofer, J.D.
1984-05-01T23:59:59.000Z
During the drilling of coalbed methane wells in the Black Warrior Basin, the possibility of penetrating a highly permeable fault or fracture zone is likely. These fracture zones, and occasionally the faults, are the source of large quantities of water. When air is being used as the drilling medium, problems may arise with producing and disposing of the formation water. When rotary drilling with fluid, loss of returns may also become a problem. The use of conventional lost circulation materials have been demonstrated-in this situation--to be both ineffective and expensive. Also, lost circulation materials substantially reduce the effective secondary permeability of the coal seams, severely limiting the ultimate methane production potential of the well. If the wellbore is generally competent, one inexpensive solution to the problem is to drill with air to a point where surface recovery tanks are full of produced formation water. Drilling can continue by switching to conventional fluid drilling until the surface storage tanks are pumped dry. This process of alternating fluid and air drilling can be continued until reaching total depth. Structural geologic information, available for the coal-bearing formations in the Black Warrior Basin, documents the occurrence of numerous fault and fracture zones. A combination air and fluid drilling technique may prove to be advantageous to coalbed methane operations in this and other areas with similar hydrologic and geologic conditions. Recently, this technique was successfully utilized on TRW, Inc., coalbed methane wells in Tuscaloosa County, Alabama.
Leenaarts, J.; Pereira, T. M. D.; Carlsson, M.; De Pontieu, B. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029, Blindern, N-0315 Oslo (Norway); Uitenbroek, H., E-mail: jorritl@astro.uio.no, E-mail: tiago.pereira@astro.uio.no, E-mail: mats.carlsson@astro.uio.no, E-mail: bdp@lmsal.com, E-mail: huitenbroek@nso.edu [NSO/Sacramento Peak, P.O. Box 62, Sunspot, NM 88349-0062 (United States)
2013-08-01T23:59:59.000Z
NASA's Interface Region Imaging Spectrograph (IRIS) space mission will study how the solar atmosphere is energized. IRIS contains an imaging spectrograph that covers the Mg II h and k lines as well as a slit-jaw imager centered at Mg II k. Understanding the observations will require forward modeling of Mg II h and k line formation from three-dimensional (3D) radiation-MHD models. This paper is the first in a series where we undertake this forward modeling. We discuss the atomic physics pertinent to h and k line formation, present a quintessential model atom that can be used in radiative transfer computations, and discuss the effect of partial redistribution (PRD) and 3D radiative transfer on the emergent line profiles. We conclude that Mg II h and k can be modeled accurately with a four-level plus continuum Mg II model atom. Ideally radiative transfer computations should be done in 3D including PRD effects. In practice this is currently not possible. A reasonable compromise is to use one-dimensional PRD computations to model the line profile up to and including the central emission peaks, and use 3D transfer assuming complete redistribution to model the central depression.
Lauderdale, Jonathan M.
The effect of idealized wind-driven circulation changes in the Southern Ocean on atmospheric CO[subscript 2] and the ocean carbon inventory is investigated using a suite of coarse-resolution, global coupled ocean circulation ...
Artificial general intelligence: an organism and level based position
Smith, Leslie S.
Artificial general intelligence: an organism and level based position statement Leslie S. SMITH 1. Keywords. artificial general intelligence, brain model, paramecium, level interaction Introduction There are many views of what should be described as artificial general intelligence. Gen- eral intelligence
Technical report: Multivariate generalized S-estimators
Van Aelst, Stefan
Technical report: Multivariate generalized S-estimators Roelant E. a, Van Aelst S. a Croux C. b a-estimators for the multivariate regression model. This class of estimators combines high robustness and high efficiency of residuals. In the special case of a multivariate location model, the generalized S-estimator has
Khangaonkar, Tarang; Wang, Taiping
2013-01-02T23:59:59.000Z
Circulation in typical fjords is characterized by a shallow brackish layer at the surface over a deep long and narrow saltwater column. This surface layer is responsible for the outflow of water from the fjord, is easily disrupted by external forces, such as wind, and is influenced by freshwater inflow. In this paper, we postulate that the stability of fjordal circulation may also be vulnerable to impacts from anthropogenic alterations, such as floating structures, that could constrict the mixing and transport in the upper layers of the water column. The potential for alteration of circulation in Hood Canal, a silled-fjord located inside Puget Sound, Washington, has been examined. Using classical analytical treatments along the lines formulated by Hansen and Rattray [1965], Rattray [1967], Dyer [1973] and more recently, MacCready [2004], we develop a solution applicable to a range of estuary classifications varying from a partially mixed estuary regime to classical fjord conditions. Both estuary types exist in the Puget Sound system, and we compare our analytical solution with observed data. The analysis is based on an exponential variation of eddy viscosity with depth, and it has been extended further with modifications of the free surface boundary conditions to develop a solution representing the presence of a floating bridge at the estuary/fjord entrance. The model results show that tidally averaged mean circulation under the influence of such a constraint could reduce by as much as 30 to 50 percent. The overall water quality of fjords and narrow estuaries is dependent on net circulation and flushing. A potential decrease in residual flow or a corresponding increase in residence time of this magnitude merits further study.
Monge, Juan
2012-10-19T23:59:59.000Z
The economic impacts of a government-funded, forest-based sequestration program were analyzed under two different payment schemes. The impacts were obtained by developing a regional, static CGE model built to accommodate a modified IMPLAN SAM for a...
Monge, Juan
2012-10-19T23:59:59.000Z
The economic impacts of a government-funded, forest-based sequestration program were analyzed under two different payment schemes. The impacts were obtained by developing a regional, static CGE model built to accommodate a modified IMPLAN SAM for a...
MEASUREMENTS OF THE SUN'S HIGH-LATITUDE MERIDIONAL CIRCULATION
Rightmire-Upton, Lisa [Department of Physics, University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Hathaway, David H. [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); Kosak, Katie, E-mail: lar0009@uah.edu, E-mail: david.hathaway@nasa.gov, E-mail: mkosak2011@my.fit.edu [Florida Institute of Technology, Melbourne, FL 32901 (United States)
2012-12-10T23:59:59.000Z
The meridional circulation at high latitudes is crucial to the buildup and reversal of the Sun's polar magnetic fields. Here, we characterize the axisymmetric flows by applying a magnetic feature cross-correlation procedure to high-resolution magnetograms obtained by the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory. We focus on Carrington rotations 2096-2107 (2010 April to 2011 March)-the overlap interval between HMI and the Michelson Doppler Imager (MDI). HMI magnetograms averaged over 720 s are first mapped into heliographic coordinates. Strips from these maps are then cross-correlated to determine the distances in latitude and longitude that the magnetic element pattern has moved, thus providing meridional flow and differential rotation velocities for each rotation of the Sun. Flow velocities were averaged for the overlap interval and compared to results obtained from MDI data. This comparison indicates that these HMI images are rotated counterclockwise by 0.{sup 0}075 with respect to the Sun's rotation axis. The profiles indicate that HMI data can be used to reliably measure these axisymmetric flow velocities to at least within 5 Degree-Sign of the poles. Unlike the noisier MDI measurements, no evidence of a meridional flow counter-cell is seen in either hemisphere with the HMI measurements: poleward flow continues all the way to the poles. Slight north-south asymmetries are observed in the meridional flow. These asymmetries should contribute to the observed asymmetries in the polar fields and the timing of their reversals.
A cryogenic circulating advective multi-pass absorption cell
Stockett, M. H.; Lawler, J. E. [Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, Wisconsin 53706 (United States)
2012-03-15T23:59:59.000Z
A novel absorption cell has been developed to enable a spectroscopic survey of a broad range of polycyclic aromatic hydrocarbons (PAH) under astrophysically relevant conditions and utilizing a synchrotron radiation continuum to test the still controversial hypothesis that these molecules or their ions could be carriers of the diffuse interstellar bands. The cryogenic circulating advective multi-pass absorption cell resembles a wind tunnel; molecules evaporated from a crucible or injected using a custom gas feedthrough are entrained in a laminar flow of cryogenically cooled buffer gas and advected into the path of the synchrotron beam. This system includes a multi-pass optical White cell enabling absorption path lengths of hundreds of meters and a detection sensitivity to molecular densities on the order of 10{sup 7} cm{sup -3}. A capacitively coupled radio frequency dielectric barrier discharge provides ionized and metastable buffer gas atoms for ionizing the candidate molecules via charge exchange and the Penning effect. Stronger than expected clustering of PAH molecules has slowed efforts to record gas phase PAH spectra at cryogenic temperatures, though such clusters may play a role in other interstellar phenomena.
Newton, James Edward
1982-01-01T23:59:59.000Z
calculat1on y1elded a I ground. state conf1gurat1on in which the bonding orbital has an occu- pation number of 1. 97 and the antibond1ng orbital has an occupat1on number of 0. 03 electrons. Both Pauling and Griffith geometr1es of Nn(0 )(H C H ) y1... Geometries. Basis sets. . Results Fenske-Hall molecular orbi tal calculations. Restricted Hartree-Fock-Roothaan-Configuration Interaction calculations. 56 58 59 ~ ~ 59 ~ ~ 61 62 62 65 Generalized Molecular Orbi tal-Conf i gurati on Interaction...
Wind Turbine Blockset General Overview
Wind Turbine Blockset in Saber General Overview and Description of the Models Florin Iov, Adrian Turbine Blockset in Saber Abstract. This report presents a new developed Saber Toolbox for wind turbine, optimize and design wind turbines". The report provides a quick overview of the Saber and then explains
Modeling pCO sub 2 in the upper ocean
Archer, D.
1990-12-01T23:59:59.000Z
This report summarizes our current understanding of the physical, chemical, and biological processes that control the natural cycling of carbon dioxide (CO{sub 2}) in the surface ocean. Because the physics of mixing at the ocean surface creates the essential framework for the chemistry and biology, and because the literature on surface ocean mixing is extensive, a major focus of the report is to review existing mixed layer models for the upper ocean and their implementation in global ocean circulation models. Three families of mixed layer models have been developed. The integrated turbulent kinetic energy'' (TKE) models construct a budget for surface ocean TKE, using the wind stress as source and dissipation as sink for TKE. The shear instability'' models maintain profiles of current velocity resulting from the wind stress. Turbulence closure'' models are the most general and the most complicated of the three types, and are based on laboratory studies of fluid turbulence. This paper explores behavioral distinctions between the three types of models, and summarizes previously published comparisons of the generality, accuracy, and computational requirements of the three models. The application of mixed layer models to treatment of sea ice is also reviewed. 101 refs., 7 figs., 1 tab.
-encounter-Bethe BEB model in which a simple expression for the optical-oscillator strength, based on the results from H, He, and H2, is employed in the ex- pression of the Bethe cross section. Both the BED and BEB
Polarized 3He Gas Circulating Technologies for Neutron Analyzers
Watt, David; Hersman, Bill
2014-12-10T23:59:59.000Z
We describe the development of an integrated system for quasi-continuous operation of a large volume neutron analyzer. The system consists of a non-magnetic diaphragm compressor, a prototype large volume helium polarizer, a surrogate neutron analyzer, a non-depolarizing gas storage reservoir, a non-ferrous valve manifold for handling gas distribution, a custom rubidium-vapor gas return purifier, and wire-wound transfer lines, all of which are immersed in a two-meter external magnetic field. Over the Phase II period we focused on three major tasks required for the successful deployment of these types of systems: 1) design and implementation of gas handling hardware, 2) automation for long-term operation, and 3) improvements in polarizer performance, specifically fabrication of aluminosilicate optical pumping cells. In this report we describe the design, implementation, and testing of the gas handling hardware. We describe improved polarizer performance resulting from improved cell materials and fabrication methods. These improvements yielded valved 8.5 liter cells with relaxation times greater than 12 hours. Pumping this cell with 1500W laser power with 1.25nm linewidth yielded peak polarizations of 60%, measured both inside and outside the polarizer. Fully narrowing this laser to 0.25nm, demonstrated separately on one stack of the four, would have allowed 70% polarization with this cell. We demonstrated the removal of 5 liters of polarized helium from the polarizer with no measured loss of polarization. We circulated the gas through a titanium-clad compressor with polarization loss below 3% per pass. We also prepared for the next phase of development by refining the design of the polarizer so that it can be engineer-certified for pressurized operation. The performance of our system far exceeds comparable efforts elsewhere.
He, Mei; Crow, Jennifer; Roth, Marc; Zeng, Yong; Godwin, Andrew K.
2014-08-06T23:59:59.000Z
new microfluidic approach to streamline and expedite the exosome analysis pipeline by integrating specific immunoisolation and targeted protein analysis of circulating exosomes. Compared to the conventional methods, our approach enables selective...
Kaminski, Edouard
Porous compaction in transient creep regime and implications for melt, petroleum, and CO2 in transient creep regime and implications for melt, petroleum, and CO2 circulation, J. Geophys. Res., 113, B
The role of the geothermal heat flux in driving the abyssal ocean circulation
Mashayek, A.
The results presented in this paper demonstrate that the geothermal heat flux (GHF) from the solid Earth into the ocean plays a non-negligible role in determining both abyssal stratification and circulation strength. Based ...
Winguth, Arne
circulation pathways through the atmosphere, hydrosphere, geosphere, and biosphere of the essential elements climate simulations suggest that CO2-induced warming will lead to reduced marine and terrestrial carbon
The Force Balance of the Southern Ocean Meridional Overturning Circulation MATTHEW R. MAZLOFF
Current (ACC) system, the polar gyres, and the meridional overturning circulation (MOC), which are linked of an equatorward Ekman transport near the surface balanced by pole- ward transport in the abyss (c 5 Ð w dy 5 ftx
Intermediate-depth circulation of the Indian and South Pacific Oceans measured by autonomous floats
Davis, Russ E
2005-01-01T23:59:59.000Z
circulation of the Pacific Ocean: Flow patterns, tracers,runs in the Indian and Pacific Oceans using the EstimatingIndian and (right) Pacific Oceans from the JPL–ECCO data-
Stability analysis of natural circulation in BWRs at high pressure conditions
Hu, Rui, Ph. D. Massachusetts Institute of Technology
2007-01-01T23:59:59.000Z
At rated conditions, a natural circulation boiling water reactor (NCBWR) depends completely on buoyancy to remove heat from the reactor core. This raises the issue of potential unstable flow. oscillations. The objective ...
Evolution of Atlantic deep-water circulation: from the greenhouse to the icehouse
Via, Rachael Kathleen
2005-11-01T23:59:59.000Z
To better understand how the evolution of Cenozoic deep-water circulation related to changes in global climate and ocean basin configuration, we generated Nd isotope records from Ocean Drilling Program sites in the southeastern Atlantic to track...
Evolution of Atlantic deep-water circulation: from the greenhouse to the icehouse
Via, Rachael Kathleen
2005-11-01T23:59:59.000Z
To better understand how the evolution of Cenozoic deep-water circulation related to changes in global climate and ocean basin configuration, we generated Nd isotope records from Ocean Drilling Program sites in the southeastern Atlantic to track...
Mayers, Jared R.
Most patients with pancreatic ductal adenocarcinoma (PDAC) are diagnosed with advanced disease and survive less than 12 months. PDAC has been linked with obesity and glucose intolerance, but whether changes in circulating ...
Telomere Length in Circulating Leukocytes Is Associated with Lung Function and Disease
Nyholt, Dale R.
Telomere Length in Circulating Leukocytes Is Associated with Lung Function and Disease Eva Albrecht. Comprehensive Pneumology Center Munich (CPC-M), Member of the German Center for Lung Research, Munich, Germany
Slip stream apparatus and method for treating water in a circulating water system
Cleveland, Joe R. (West Hills, CA)
1997-01-01T23:59:59.000Z
An apparatus (10) for treating water in a circulating water system (12) t has a cooling water basin (14) includes a slip stream conduit (16) in flow communication with the circulating water system (12), a source (36) of acid solution in flow communication with the slip stream conduit (16), and a decarbonator (58) in flow communication with the slip stream conduit (16) and the cooling water basin (14). In use, a slip stream of circulating water is drawn from the circulating water system (12) into the slip stream conduit (16) of the apparatus (10). The slip stream pH is lowered by contact with an acid solution provided from the source (36) thereof. The slip stream is then passed through a decarbonator (58) to form a treated slip stream, and the treated slip stream is returned to the cooling water basin (14).
Armour, Kyle C.
We propose here that the Atlantic meridional overturning circulation (AMOC) plays an important role in setting the effective heat capacity of the World Ocean and thus impacts the pace of transient climate change. The depth ...
The Full Water Disposal Ways and Study on Central Air-conditioning Circulation Cooling Water System
Zhang, J.
2006-01-01T23:59:59.000Z
This paper has been made the further study about the water quality issue of the central air-conditioning circulation cooling water. Based on the comparison of the existing common adopted disposal ways, put forward the new ways of combination...
The Full Water Disposal Ways and Study on Central Air-conditioning Circulation Cooling Water System
Zhang, J.
2006-01-01T23:59:59.000Z
This paper has been made the further study about the water quality issue of the central air-conditioning circulation cooling water. Based on the comparison of the existing common adopted disposal ways, put forward the new ways of combination...
Sensitivity of the Ocean's Meridional Overturning Circulation to Surface Conditions in the Paleogene
Haines, Brian Andrew
2012-10-19T23:59:59.000Z
Deep circulations in the ocean affect the distribution of physical, chemical, and biological properties, and are intimately entwined with the planetary-scale climate. Numerous proxies, including neodymium (Nd) in fossil fish teeth, point to a source...
Sensitivity of the Ocean's Meridional Overturning Circulation to Surface Conditions in the Paleogene
Haines, Brian Andrew
2012-10-19T23:59:59.000Z
Deep circulations in the ocean affect the distribution of physical, chemical, and biological properties, and are intimately entwined with the planetary-scale climate. Numerous proxies, including neodymium (Nd) in fossil fish teeth, point to a source...
CaltechWater January 27, 2006 The Global Circulation of
Roca, Rémy
. Despite advances in computer power, energy balance models and their some- what embellished cousins for determining whether key processes operate in the same way in models as in the real world become brighter
Evaluation of equipment and methods to map lost circulation zones in geothermal wells
McDonald, W.J.; Leon, P.A.; Pittard, G.
1981-05-01T23:59:59.000Z
A study and evaluation of methods to locate, characterize, and quantify lost circulation zones are described. Twenty-five methods of mapping and quantifying lost circulation zones were evaluated, including electrical, acoustical, mechanical, radioactive, and optical systems. Each tool studied is described. The structured, numerical evaluation plan, used as the basis for comparing the 25 tools, and the resulting ranking among the tools is presented.
Fulton, Murray Evans
1978-01-01T23:59:59.000Z
, the BEA (Bureau of Economic Analysis, U. S. Department of Commerce) manufacturing capacity utili- zation index, and the Federal Reserve Board index of capacity utilization all depend heavily on primary data for their measures of economic capacity... are then examined. Of these, input-output analysis is chosen as being the most suitable for use in examining capacity-related questions. Linear programming (LPIO) and quadratic programming (QPIO) approaches to solving an input- output model are reviewed...
Bed-inventory Overturn Mechanism for Pant-leg Circulating Fluidized Bed Boilers
Wang, Zhe; Yang, Zhiwei; West, Logan; Li, Zheng
2011-01-01T23:59:59.000Z
A numerical model was established to investigate the lateral mass transfer as well as the mechanism of bed-inventory overturn inside a pant-leg circulating fluidized bed (CFB), which are of great importance to maintain safe and efficient operation of the CFB. Results show that the special flow structure in which the solid particle volume fraction along the central line of the pant-leg CFB is relative high enlarges the lateral mass transfer rate and make it more possible for bed inventory overturn. Although the lateral pressure difference generated from lateral mass transfer inhibits continuing lateral mass transfer, providing the pant-leg CFB with self-balancing ability to some extent, the primary flow rate change due to the outlet pressure change often disable the self-balancing ability by continually enhancing the flow rate difference. As the flow rate of the primary air fan is more sensitive to its outlet pressure, it is easier to lead to bed inventory overturn. While when the solid particle is easier to c...
Experimental study of the hydrodynamics and cluster formation in a Circulating Fluidized Bed
Gautam, M.; Johnson, E.
1991-01-01T23:59:59.000Z
A novel non-invasive gas-solid flow measuring technique being developed and tested for studying the hydrodynamics inside the riser of a Circulating Fluidized Bed (CFB). First of the two aims of the overall program, namely, design, development and testing of the technique to characterize the particle and gas velocities in two-phase flows was accomplished in the past year. The fringe-model'' laser Doppler anemometry concept has been modified and extended by using particles coated with a fluorescent dye and introducing a narrow band pass filter in the receiving optics. The technique permits optical discrimination between the scattered light (laser wavelength from undyed particles) and the fluorescence emission (longer wavelength). Results from extensive testing of various dye-solvent combinations, counter processor settings, signal-to noise optimization and subsequent flow measurements in the test section have shown that the technique can effectively discriminate between two classes of particles--the smaller seed particles for the gas phase data and the larger bed particles. Use of a two-watt Argon-Ion laser assisted in the non-intrusive probing of the gas-solid flow and in enhancing the signal-to-noise ratio. An uncertainty analysis of LDA measurements is presented. Design of the cold flow CFB model, presently under fabrication, is outlined in this report. The Plexiglas CFB model will be employed for the riser core-annular flow studies using the fluorescence-emission based laser-Doppler anemometry. The results from this study will present a unique detailed description of the complex gas-solid behavior in the CFB riser.
A General Relativistic Generalization of Bell Inequality
Vladan Pankovic
2005-06-16T23:59:59.000Z
In this work a general relativistic generalization of Bell inequality is suggested. Namely,it is proved that practically in any general relativistic metric there is a generalization of Bell inequality.It can be satisfied within theories of local (subluminal) hidden variables, but it cannot be satisfied in the general case within standard quantum mechanical formalism or within theories of nonlocal (superluminal) hidden variables. It is shown too that within theories of nonlocal hidden variables but not in the standard quantum mechanical formalism a paradox appears in the situation when one of the correlated subsystems arrives at a Schwarzschild black hole. Namely, there is no way that black hole horizon obstructs superluminal influences between spin of the subsystem without horizon and spin of the subsystem within horizon,or simply speaking,there is none black hole horizon nor "no hair" theorem for subsystems with correlated spins. It implies that standard quantum mechanical formalism yields unique consistent and complete description of the quantum mechanical phenomenons.
Inference for Model Error Allan Seheult
Oakley, Jeremy
Reservoirs, Model Error, Reification, Thermohaline Circulation. 1 Introduction Mathematical models of complex that the uncertainties associated with both calibrating a mathematical model to observations on a physical system specification exercise of model error with the cosmologists, linked to an extensive analysis of model
Puget Sound Dissolved Oxygen Modeling Study: Development of an Intermediate-Scale Hydrodynamic Model
Yang, Zhaoqing; Khangaonkar, Tarang; Labiosa, Rochelle G.; Kim, Taeyun
2010-11-30T23:59:59.000Z
The Washington State Department of Ecology contracted with Pacific Northwest National Laboratory to develop an intermediate-scale hydrodynamic and water quality model to study dissolved oxygen and nutrient dynamics in Puget Sound and to help define potential Puget Sound-wide nutrient management strategies and decisions. Specifically, the project is expected to help determine 1) if current and potential future nitrogen loadings from point and non-point sources are significantly impairing water quality at a large scale and 2) what level of nutrient reductions are necessary to reduce or dominate human impacts to dissolved oxygen levels in the sensitive areas. In this study, an intermediate-scale hydrodynamic model of Puget Sound was developed to simulate the hydrodynamics of Puget Sound and the Northwest Straits for the year 2006. The model was constructed using the unstructured Finite Volume Coastal Ocean Model. The overall model grid resolution within Puget Sound in its present configuration is about 880 m. The model was driven by tides, river inflows, and meteorological forcing (wind and net heat flux) and simulated tidal circulations, temperature, and salinity distributions in Puget Sound. The model was validated against observed data of water surface elevation, velocity, temperature, and salinity at various stations within the study domain. Model validation indicated that the model simulates tidal elevations and currents in Puget Sound well and reproduces the general patterns of the temperature and salinity distributions.
Generalized Jordan-Wigner Transformations
Batista, C. D.; Ortiz, G.
2001-02-05T23:59:59.000Z
We introduce a new spin-fermion mapping, for arbitrary spin S generating the SU(2) group algebra, that constitutes a natural generalization of the Jordan-Wigner transformation for S=1/2. The mapping, valid for regular lattices in any spatial dimension d , serves to unravel hidden symmetries. We illustrate the power of the transformation by finding exact solutions to lattice models previously unsolved by standard techniques. We also show the existence of the Haldane gap in S=1 bilinear nearest-neighbor Heisenberg spin chains and discuss the relevance of the mapping to models of strongly correlated electrons. Moreover, we present a general spin-anyon mapping for the case d{<=}2 .
Generalized Jordan-Wigner Transformations
C. D. Batista; G. Ortiz
2000-08-25T23:59:59.000Z
We introduce a new spin-fermion mapping, for arbitrary spin $S$ generating the SU(2) group algebra, that constitutes a natural generalization of the Jordan-Wigner transformation for $S=1/2$. The mapping, valid for regular lattices in any spatial dimension $d$, serves to unravel hidden symmetries in one representation that are manifest in the other. We illustrate the power of the transformation by finding exact solutions to lattice models previously unsolved by standard techniques. We also present a proof of the existence of the Haldane gap in $S=$1 bilinear nearest-neighbors Heisenberg spin chains and discuss the relevance of the mapping to models of strongly correlated electrons. Moreover, we present a general spin-anyon mapping for the case $d \\leq 2$.
Black holes in general relativity
Visser, Matt
2009-01-01T23:59:59.000Z
What is going on (as of August 2008) at the interface between theoretical general relativity, string-inspired models, and observational astrophysics? Quite a lot. In this mini-survey I will make a personal choice and focus on four specific questions: Do black holes "exist"? (For selected values of the word "exist".) Is black hole formation and evaporation unitary? Can one mimic a black hole to arbitrary accuracy? Can one detect the presence of a horizon using local physics?
Generalized Elitzur's Theorem and Dimensional Reduction
Cristian D. Batista; Zohar Nussinov
2005-03-10T23:59:59.000Z
We extend Elitzur's theorem to systems with symmetries intermediate between global and local. In general, our theorem formalizes the idea of {\\it dimensional reduction}. We apply the results of this generalization to many systems that are of current interest. These include liquid crystalline phases of Quantum Hall systems, orbital systems, geometrically frustrated spin lattices, Bose metals, and models of superconducting arrays.