Lysozyme Protein Solution with an Intermediate Range Order Structure
Liu, Yun [National Institute of Standards and Technology (NIST); Porcar, L. [National Institute of Standards and Technology (NIST); Chen, Wei-Ren [ORNL; Chen, Jinhong [Memorial Sloan-Kettering Cancer Center; Falus, Peter [ORNL; Fratini, Emiliano [University of Florence; Faraone, Antonio [National Institute of Standards and Technology (NIST); Baglioni, P [University of Florence
2011-01-01
The formation of equilibrium clusters has been studied in both a prototypical colloidal system and protein solutions. The appearance of a low-Q correlation peak in small angle scattering patterns of lysozyme solution was attributed to the cluster-cluster correlation. Consequently, the presence of long-lived clusters has been established. By quantitatively analyzing both the SANS (small angle neutron scattering) and NSE (neutron spin echo) data of lysozyme solution using statistical mechanics models, we conclusively show in this paper that the appearance of a low-Q peak is not a signature of the formation of clusters. Rather, it is due to the formation of an intermediate range order structure governed by a short-range attraction and a long-range repulsion. We have further studied dynamic features of a sample with high enough concentration at which clusters are formed in solution. From the estimation of the mean square displacement by using short-time and long-time diffusion coefficient measured by NSE and NMR, we find that these clusters are not permanent but have a finite lifetime longer than the time required to diffuse over a distance of a monomer diameter.
Jérémie Gummel; Fabrice Cousin; François Boué
2009-03-30
Measurements of chain conformation in proteins/polyelectrolytes complexes (lysozyme and PSSNa) show that the crossover observed between an open structure -a chain network crosslinked by the proteins, and a globular one - dense globules of ~ 10 nm aggregated in a fractal way, results from a conformation modification prior to the transition. Before showing this, we have widened the parameters range for the observation of the transition. We had shown before that the two structures can be formed depending on chain length (for a given [PSS]/[lysozyme] ratio): gel for large chains, globules for short chains. We show here that the crossover between these two regimes can also be reached as a function of chains concentration or salinity of the buffer. Since all these crossover parameters act on chains overlapping concentration c*, we reinforce the idea of a transition from the dilute to the semi-dilute regime, but c* is shifted compared to pure PSS solutions. In order to understand this, we have measured by SANS the conformation of a single chain of PSS in presence of proteins within the complexes. This is achieved by a specific labeling trick where we take advantage of the fact that lysozyme and hydrogenated PSS chains have the same neutron scattering length density. In the gel structure, the PSS chains keep a wormlike structure as in pure solutions, but their persistence length is strongly reduced, from 50 {\\AA} without proteins to 20 {\\AA} in average with lysozyme. With this value of 20 {\\AA}, we calculate new overlapping thresholds (concentration, mass, ionic strength) in agreement with observed ones. In a second stage, after the globular structure is formed, the PSS chains get a third conformation, no longer wormlike, but more collapsed, within the globules.
Effect of alcohols on aqueous lysozyme-lysozyme interactions...
Office of Scientific and Technical Information (OSTI)
Effect of alcohols on aqueous lysozyme-lysozyme interactions from static light-scattering measurements Citation Details In-Document Search Title: Effect of alcohols on aqueous...
A zinc complex of heparan sulfate destabilises lysozyme and alters its conformation
Hughes, Ashley J. [Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB (United Kingdom) [Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB (United Kingdom); Diamond Light Source Ltd., Diamond House, Didcot, Oxfordshire OX11 0DE (United Kingdom); Hussain, Rohanah [Diamond Light Source Ltd., Diamond House, Didcot, Oxfordshire OX11 0DE (United Kingdom)] [Diamond Light Source Ltd., Diamond House, Didcot, Oxfordshire OX11 0DE (United Kingdom); Cosentino, Cesare; Guerrini, Marco [Istituto di Chimica e Biochimica 'G. Ronzoni', Via G. Colombo 81, Milano 20133 (Italy)] [Istituto di Chimica e Biochimica 'G. Ronzoni', Via G. Colombo 81, Milano 20133 (Italy); Siligardi, Giuliano [Diamond Light Source Ltd., Diamond House, Didcot, Oxfordshire OX11 0DE (United Kingdom)] [Diamond Light Source Ltd., Diamond House, Didcot, Oxfordshire OX11 0DE (United Kingdom); Yates, Edwin A., E-mail: eayates@liv.ac.uk [Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB (United Kingdom); Rudd, Timothy R., E-mail: trudd@liv.ac.uk [Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB (United Kingdom); Istituto di Chimica e Biochimica 'G. Ronzoni', Via G. Colombo 81, Milano 20133 (Italy)
2012-09-07
Highlights: Black-Right-Pointing-Pointer Zinc-heparan sulfate complex destabilises lysozyme, a model amyloid protein. Black-Right-Pointing-Pointer Addition of zinc, without heparan sulfate, stabilises lysozyme. Black-Right-Pointing-Pointer Heparan sulfate cation complexes provide alternative protein folding routes. -- Abstract: The naturally occurring anionic cell surface polysaccharide heparan sulfate is involved in key biological activities and is implicated in amyloid formation. Following addition of Zn-heparan sulfate, hen lysozyme, a model amyloid forming protein, resembled {beta}-rich amyloid by far UV circular dichroism (increased {beta}-sheet: +25%), with a significantly reduced melting temperature (from 68 to 58 Degree-Sign C) by fluorescence shift assay. Secondary structure stability of the Zn-heparan sulfate complex with lysozyme was also distinct from that with heparan sulfate, under stronger denaturation conditions using synchrotron radiation circular dichroism. Changing the cation associated with heparan sulfate is sufficient to alter the conformation and stability of complexes formed between heparan sulfate and lysozyme, substantially reducing the stability of the protein. Complexes of heparan sulfate and cations, such as Zn, which are abundant in the brain, may provide alternative folding routes for proteins.
Single Molecule Recordings of Lysozyme Activity
Collins, Philip G
2013-01-01
governing lysozyme productivity. Continuous long-term monitoring promises to distinguish between ‘‘static’’ disorder
Skolnick, Jeff
Fuzzy-Oil-Drop Hydrophobic Force Field A Model to Represent Late-stage Folding (In Silico the external field in the form of a fuzzy-oil-drop assumed to represent the environment. The drop is expressed is the parameter to be mini- mized in the structure optimization procedure. The size of fuzzy-oil-drop is critical
N-Terminal T4 Lysozyme Fusion Facilitates Crystallization of...
Office of Scientific and Technical Information (OSTI)
N-Terminal T4 Lysozyme Fusion Facilitates Crystallization of a G Protein Coupled Receptor Citation Details In-Document Search Title: N-Terminal T4 Lysozyme Fusion Facilitates...
Light scattering and phase behavior of Lysozyme-PEG mixtures
J. Bloustine; T. Virmani; G. M. Thurston; S. Fraden
2005-12-14
Measurements of liquid-liquid phase transition temperatures (cloud points) of mixtures of a protein (lysozyme) and a polymer, poly(ethylene glycol) (PEG) show that the addition of low molecular weight PEG stabilizes the mixture whereas high molecular weight PEG was destabilizing. We demonstrate that this behavior is inconsistent with an entropic depletion interaction between lysozyme and PEG and suggest that an energetic attraction between lysozyme and PEG is responsible. In order to independently characterize the lysozyme/PEG interactions, light scattering experiments on the same mixtures were performed to measure second and third virial coefficients. These measurements indicate that PEG induces repulsion between lysozyme molecules, contrary to the depletion prediction. Furthermore, it is shown that third virial terms must be included in the mixture's free energy in order to qualitatively capture our cloud point and light scattering data. The light scattering results were consistent with the cloud point measurements and indicate that attractions do exist between lysozyme and PEG.
Modified T4 Lysozyme Fusion Proteins Facilitate G Protein-Coupled...
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Modified T4 Lysozyme Fusion Proteins Facilitate G Protein-Coupled Receptor Crystallogenesis Citation Details In-Document Search Title: Modified T4 Lysozyme Fusion Proteins...
Crystallization of lysozyme with (R)-, (S)- and (RS)-2-methyl-2, 4-pentanediol
Stauber, Mark; Jakoncic, Jean; Berger, Jacob; Karp, Jerome M.; Axelbaum, Ariel; Sastow, Dahniel; Buldyrev, Sergey V.; Hrnjez, Bruce J.; Asherie, Neer
2015-03-01
Crystallization of lysozyme with (R)-2-methyl-2, 4-pentanediol produces more ordered crystals and a higher resolution protein structure than crystallization with (S)-2-methyl-2, 4-pentanediol. The results suggest that chiral interactions with chiral additives are important in protein crystal formation. Chiral control of crystallization has ample precedent in the small-molecule world, but relatively little is known about the role of chirality in protein crystallization. In this study, lysozyme was crystallized in the presence of the chiral additive 2-methyl-2, 4-pentanediol (MPD) separately using the R and S enantiomers as well as with a racemic RS mixture. Crystals grown with (R)-MPD had the most order and produced the highest resolution protein structures. This result is consistent with the observation that in the crystals grown with (R)-MPD and (RS)-MPD the crystal contacts are made by (R)-MPD, demonstrating that there is preferential interaction between lysozyme and this enantiomer. These findings suggest that chiral interactions are important in protein crystallization.
Rodlike Complexes of a Polyelectrolyte (Hyaluronan) and a Protein (Lysozyme) observed by SANS
François Boué; Eric Buhler; Fabrice Cousin; Isabelle Grillo; Isabelle Morfin
2012-10-03
We study by Small Angle Neutron Scattering (SANS) the structure of Hyaluronan -Lysozyme complexes. Hyaluronan (HA) is a polysaccharide of 9 nm intrinsic persistence length that bears one negative charge per disaccharide monomer (Mmol = 401.3 g/mol); two molecular weights, Mw = 6000 and 500 000 Da were used. The pH was adjusted at 4.7 and 7.4 so that lysozyme has a global charge of +10 and + 8 respectively. The lysozyme concentration was varied from 3 to 40 g/L, at constant HA concentration (10 g/L). At low protein concentration, samples are monophasic and SANS experiments reveal only fluctuations of concentration although, at high protein concentration, clusters are observed by SANS in the dense phase of the diphasic samples. In between, close to the onset of the phase separation, a distinct original scattering is observed. It is characteristic of a rod-like shape, which could characterize "single" complexes involving one or a few polymer chains. For the large molecular weight (500 000) the rodlike rigid domains extend to much larger length scale than the persistence length of the HA chain alone in solution and the range of the SANS investigation. They can be described as a necklace of proteins attached along a backbone of diameter one or a few HA chains. For the short chains (Mw ~ 6000), the rod length of the complexes is close to the chain contour length (~ 15 nm).
Protein Structure Modeling With MODELLER Narayanan Eswar$
Sali, Andrej
of MODELLER to construct a comparative model for a protein with unknown structure. Automation of similar se- quence and the template(s); (iii) building a model based on the alignment with the cho- sen user intervention and within minutes on a desktop computer. Apart from model building, MODELLER can
Structural Equation Modeling For Travel Behavior Research
Golob, Thomas F.
2011-01-01
STREAMS (Structural Equation Modeling Made Simple) is aGerbing, 1988. Structural equation modeling in practice: aP.M. , 1989. EQS Structural Equations Program Manual. BMDP
SPAR Model Structural Efficiencies
John Schroeder; Dan Henry
2013-04-01
The Nuclear Regulatory Commission (NRC) and the Electric Power Research Institute (EPRI) are supporting initiatives aimed at improving the quality of probabilistic risk assessments (PRAs). Included in these initiatives are the resolution of key technical issues that are have been judged to have the most significant influence on the baseline core damage frequency of the NRC’s Standardized Plant Analysis Risk (SPAR) models and licensee PRA models. Previous work addressed issues associated with support system initiating event analysis and loss of off-site power/station blackout analysis. The key technical issues were: • Development of a standard methodology and implementation of support system initiating events • Treatment of loss of offsite power • Development of standard approach for emergency core cooling following containment failure Some of the related issues were not fully resolved. This project continues the effort to resolve outstanding issues. The work scope was intended to include substantial collaboration with EPRI; however, EPRI has had other higher priority initiatives to support. Therefore this project has addressed SPAR modeling issues. The issues addressed are • SPAR model transparency • Common cause failure modeling deficiencies and approaches • Ac and dc modeling deficiencies and approaches • Instrumentation and control system modeling deficiencies and approaches
Structural Analysis of Combustion Models
Tóth, J; Zsély, I
2013-01-01
Using ReactionKinetics, a Mathematica based package a few dozen detailed models for combustion of hydrogen, carbon monoxide and methanol are investigated. Essential structural characteristics are pulled out, and similarities and differences of the mechanisms are highlighted. These investigations can be used before or parallel with usual numerical investigations, such as pathway analysis, sensitivity analysis, parameter estimation, or simulation.
Crystallization of lysozyme with (R)-, (S)- and (RS)-2-methyl-2,4-pentanediol
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Stauber, Mark; Jakoncic, Jean; Berger, Jacob; Karp, Jerome M.; Axelbaum, Ariel; Sastow, Dahniel; Buldyrev, Sergey V.; Hrnjez, Bruce J.; Asherie, Neer
2015-03-01
Chiral control of crystallization has ample precedent in the small-molecule world, but relatively little is known about the role of chirality in protein crystallization. In this study, lysozyme was crystallized in the presence of the chiral additive 2-methyl-2,4-pentanediol (MPD) separately using the R and S enantiomers as well as with a racemic RS mixture. Crystals grown with (R)-MPD had the most order and produced the highest resolution protein structures. This result is consistent with the observation that in the crystals grown with (R)-MPD and (RS)-MPD the crystal contacts are made by (R)-MPD, demonstrating that there is preferential interaction between lysozymemore »and this enantiomer. These findings suggest that chiral interactions are important in protein crystallization.« less
Dynamics of lysozyme and its hydration water under electric field
P. M. Favi; Q. Zhang; H. O'Neill; E. Mamontov; S. O. Diallo
2013-12-06
The effects of static electric field on the dynamics of lysozyme and its hydration water have been investigated by means of incoherent quasi-elastic neutron scattering (QENS). Measurements were performed on lysozyme samples, hydrated respectively with heavy water (D2O) to capture the protein dynamics, and with light water (H2O), to probe the dynamics of the hydration shell, in the temperature range from 210 $water per gram of dry protein. The field strengths investigated were respectively 0 kV/mm and 2 kV/mm (2 10$^6$ V/m) for the protein hydrated with D2O and 0 kV and 1 kV/mm for the H2O hydrated counterpart. While the overall internal protons dynamics of the protein appears to be unaffected by the application of electric field up to 2 kV/mm, likely due to the stronger intra-molecular interactions, there is also no appreciable quantitative enhancement of the diffusive dynamics of the hydration water, as would be anticipated based on our recent observations in water confined in silica pores under field values of 2.5 kV/mm. This may be due to the difference in surface interactions between water and the two adsorption hosts (silica and protein), or to the existence of a critical threshold field value Ec $\\sim$ 2-3 kV/mm for increased molecular diffusion, for which electrical breakdown is a limitation for our sample.
-structures and s-structures: Translating the models Gunter Fuchs
Fuchs, Gunter
-structures and s-structures: Translating the models Gunter Fuchs WestfÂ¨alische Wilhelms a translation procedure between -structures, which correspond to premice in the Friedman-Jensen indexing convention on the one hand and s-structures, which are essentially the same as premice in the Mitchell
Structure formation: Models, Dynamics and Status
T. Padmanabhan
1995-08-25
The constraints on the models for the structure formation arising from various cosmological observations at different length scales are reviewed. The status of different models for structure formation is examined critically in the light of these observations.
Hybrid Model Structures Aaron David Ames
Ames, Aaron
Hybrid Model Structures by Aaron David Ames B.A. (University of St. Thomas) 2001 B.S. (University of California, Berkeley Fall 2006 #12;Hybrid Model Structures Copyright 2006 by Aaron David Ames #12;Abstract Hybrid Model Structures by Aaron David Ames Masters of Arts in Mathematics University of California
Crystallization of lysozyme with (R)-, (S)- and (RS)-2-methyl-2,4-pentanediol
Stauber, Mark; Jakoncic, Jean; Berger, Jacob; Karp, Jerome M.; Axelbaum, Ariel; Sastow, Dahniel; Buldyrev, Sergey V.; Hrnjez, Bruce J.; Asherie, Neer
2015-03-01
Chiral control of crystallization has ample precedent in the small-molecule world, but relatively little is known about the role of chirality in protein crystallization. In this study, lysozyme was crystallized in the presence of the chiral additive 2-methyl-2,4-pentanediol (MPD) separately using the R and S enantiomers as well as with a racemic RS mixture. Crystals grown with (R)-MPD had the most order and produced the highest resolution protein structures. This result is consistent with the observation that in the crystals grown with (R)-MPD and (RS)-MPD the crystal contacts are made by (R)-MPD, demonstrating that there is preferential interaction between lysozyme and this enantiomer. These findings suggest that chiral interactions are important in protein crystallization.
Smart Structures: Model Development and Control Applications
Smart Structures: Model Development and Control Applications Ralph C. Smith Center for Research for smart structure which utilize piezoelectric, electrostrictive, magnetostrictive or shape memory alloys of the structure. The limitations on the mass and size of transducers are often relaxed in industrial applications
Liu, David R.
HRV TEV None HCV HRV TEV PA-RNAP 118kDa Cleaved T7 RNAP 99kDa 250kDa 150kDa 75kDa None HCV HRV TEV None HCV HRV TEV 100kDa Ladder #12;7 Supplementary Figure 7. Vector map of mutagenesis plasmid (MPPCR HCVcontrolPCR TEVcontrolPCR HCVcontrolPCR TEVcontrolPCR 3kb 2kb 1kb 3kb 2kb 1kb 0 8 24 48 Time (h) HRV Mock
The Structure of Tradeoffs in Model Building
Weisberg, Michael
The Structure of Tradeoffs in Model Building John Matthewson Australia National University Michael of model building depending on their theoretical goals (1966). His own discussion argued that a three three types of tradeoff relevant for model building. After giving definitions for these, we investigate
Bayesian Multivariate Autoregressive Models with Structured Priors
Roberts, Stephen
Bayesian Multivariate Autoregressive Models with Structured Priors W:D:Penny 1 and S:J:Roberts 2 (1) learning algorithm for param- eter estimation and model order selection in Multivariate Autoregressive (MAR and electro-encephalogram (EEG) data. 2 #12; 1 Introduction The Multivariate Autoregressive (MAR) process
Introduction and Motivation Structural Model for Laminated Glass Beams Conclusions and Outlook 1 #12;Introduction and Motivation Structural Model for Laminated Glass Beams Conclusions and Outlook Outline 1 Introduction and Motivation 2 Structural Model for Laminated Glass Beams 3 Conclusions
Structure Profile by a Model of Precipitation
Wang, Zhenggang
2009-01-01
The organizational structure of a network is investigated with a simulated precipitation model which does not make use of prior knowledge about the community structure of the network. The result is presented as a structure profile through which various definitions of communities can be applied for specific applications. The simulated precipitation model performs the grouping of nodes so that nodes belonging to the same 'community' automatically aggregate, thereby revealing regions of the adjacency matrix with denser interconnections. The process is analogous to massive particles precipitating towards the lower potential layer. Without loss of the infrastructure information, a community structure profile of a network can be obtained as the ground state of the Hamiltonian. The method is also applicable to directed and weighted networks.
Modeling Fission Product Sorption in Graphite Structures
Szlufarska, Izabela; Morgan, Dane; Allen, Todd
2013-04-08
The goal of this project is to determine changes in adsorption and desorption of fission products to/from nuclear-grade graphite in response to a changing chemical environment. First, the project team will employ principle calculations and thermodynamic analysis to predict stability of fission products on graphite in the presence of structural defects commonly observed in very high- temperature reactor (VHTR) graphites. Desorption rates will be determined as a function of partial pressure of oxygen and iodine, relative humidity, and temperature. They will then carry out experimental characterization to determine the statistical distribution of structural features. This structural information will yield distributions of binding sites to be used as an input for a sorption model. Sorption isotherms calculated under this project will contribute to understanding of the physical bases of the source terms that are used in higher-level codes that model fission product transport and retention in graphite. The project will include the following tasks: Perform structural characterization of the VHTR graphite to determine crystallographic phases, defect structures and their distribution, volume fraction of coke, and amount of sp2 versus sp3 bonding. This information will be used as guidance for ab initio modeling and as input for sorptivity models; Perform ab initio calculations of binding energies to determine stability of fission products on the different sorption sites present in nuclear graphite microstructures. The project will use density functional theory (DFT) methods to calculate binding energies in vacuum and in oxidizing environments. The team will also calculate stability of iodine complexes with fission products on graphite sorption sites; Model graphite sorption isotherms to quantify concentration of fission products in graphite. The binding energies will be combined with a Langmuir isotherm statistical model to predict the sorbed concentration of fission products on each type of graphite site. The model will include multiple simultaneous adsorbing species, which will allow for competitive adsorption effects between different fission product species and O and OH (for modeling accident conditions).
Feature extraction for structural dynamics model validation
Hemez, Francois [Los Alamos National Laboratory; Farrar, Charles [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory; Nishio, Mayuko [UNIV OF TOKYO; Worden, Keith [UNIV OF SHEFFIELD; Takeda, Nobuo [UNIV OF TOKYO
2010-11-08
This study focuses on defining and comparing response features that can be used for structural dynamics model validation studies. Features extracted from dynamic responses obtained analytically or experimentally, such as basic signal statistics, frequency spectra, and estimated time-series models, can be used to compare characteristics of structural system dynamics. By comparing those response features extracted from experimental data and numerical outputs, validation and uncertainty quantification of numerical model containing uncertain parameters can be realized. In this study, the applicability of some response features to model validation is first discussed using measured data from a simple test-bed structure and the associated numerical simulations of these experiments. issues that must be considered were sensitivity, dimensionality, type of response, and presence or absence of measurement noise in the response. Furthermore, we illustrate a comparison method of multivariate feature vectors for statistical model validation. Results show that the outlier detection technique using the Mahalanobis distance metric can be used as an effective and quantifiable technique for selecting appropriate model parameters. However, in this process, one must not only consider the sensitivity of the features being used, but also correlation of the parameters being compared.
Grothey, Andreas
Optimization Modelling Example Design Implementation Conclusions A Structure-Conveying Modelling Languages for Mathematical Programming 3 An example problem from network design 4 Design of Structured, K. Woodsend Structure-Conveying Modelling Language #12;Optimization Modelling Example Design
Subspace modelling for structured noise suppression
Zhiqiang Xu; Laura Rebollo-Neira; A. Plastino
2009-08-07
The problem of structured noise suppression is addressed by i)modelling the subspaces hosting the components of the signal conveying the information and ii)applying a non-extensive nonlinear technique for effecting the right separation. Although the approach is applicable to all situations satisfying the hypothesis of the proposed framework, this work is motivated by a particular scenario, namely, the cancellation of low frequency noise in broadband seismic signals.
Infrastructure for 3D model reconstruction of marine structures
Kurniawati, Hanna
2011-01-01
3D model reconstruction of marine structures, such as dams, oil-rigs, and sea caves, is both important and challenging. An important application includes structural inspection. Manual inspection of marine structures is ...
Fit Index Sensitivity in Multilevel Structural Equation Modeling
Boulton, Aaron Jacob
2011-07-29
Multilevel Structural Equation Modeling (MSEM) is used to estimate latent variable models in the presence of multilevel data. A key feature of MSEM is its ability to quantify the extent to which a hypothesized model fits ...
Evolution of Middle Eastern Social Structures: a new model
White, Douglas R.
Evolution of Middle Eastern Social Structures: a new model Abstract The desert is small relative: evolution, endogamy, population, raiding, Bedouin,] #12;2 Evolution of Middle Eastern Social Structures
NOTES TOWARD A MODEL FOR THE STRUCTURE OF KNOWLEDGE SYSTEMS
Futrell, Richard H.
1972-10-01
This paper reviews two formulations of some structural aspects of knowledge systems. These two structural specifications of knowledge systems, by Judith Willer and by Norwood Russell Hanson, are then combined to suggest a model for relating several...
Robust nite-di erence modelling of complex structures1
Cerveny, Vlastislav
with the 1Proc. of HIGH PERFORMANCE COMPUTING IN SEISMIC MODELLING, An International Sympo- sium, Zaragoza-difference modelling of complex structures Paper No. 15 in Proc. of Int. Symposium on High Performance Computing
Exploiting Compositionality to Explore a Large Space of Model Structures
Grosse, Roger Baker
The recent proliferation of richly structured probabilistic models raises the question of how to automatically determine an appropriate model for a dataset. We investigate this question for a space of matrix decomposition ...
Continuous mutual improvement of macromolecular structure models...
Office of Scientific and Technical Information (OSTI)
software: The dual role of deposited experimental data Accurate crystal structures of macromolecules are of high importance in the biological and biomedical fields....
Modeling and Optimal Design of Di ractive Optical Structures
Dobson, David C.
Modeling and Optimal Design of Di ractive Optical Structures Gang Bao Department of Mathematics be designed to perform functions unattainable with traditionaloptical elements. For example, structures and for the determination of optimal" device designs. In contrast to the case of traditional optical structures, geometrical
Modeling covariance structure in unbalanced longitudinal data
Chen, Min
2009-05-15
-effects models: average maximum likelihood estimators and Monte Carlo standard deviations from the true model and five scenarios considered in the simulation study. . 55 ix LIST OF FIGURES FIGURE Page 1 Fitted log-innovation variances and generalized... autoregressive pa- rameters for the fixed-effects model with 10% of the cattle data missing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 2 Fitted log-innovation variances and generalized autoregressive pa- rameters for the fixed...
Structural Equation Modeling For Travel Behavior Research
Golob, Thomas F.
2001-01-01
T.F. R. Kitamura and C. Lula, 1994. Modeling the Effects ofand Golob, Kitamura and Lula (1994) were the first to apply
Structural Equation Modeling for Travel Behavior Research
Golob, Thomas F.
2001-01-01
T.F. R. Kitamura and C. Lula, 1994. Modeling the Effects ofand Golob, Kitamura and Lula (1994) were the first to apply
Structural Equation Modeling For Travel Behavior Research
Golob, Thomas F.
2011-01-01
T.F. R. Kitamura and C. Lula, 1994. Modeling the Effects ofand Golob, Kitamura and Lula (1994) were the first to apply
A Model for Interlevel Coupling Noise in Multilevel Interconnect ' Structures
Swaminathan, Madhavan
A Model for Interlevel Coupling Noise in Multilevel Interconnect ' Structures Martin Saint- case noise is simulated using an RC transmission line model that includes the timing of the attackers noise model is sometimes very desirable, in particular for the design of clock distribution networks
Distributed Prognostics Based on Structural Model Decomposition
Daigle, Matthew
efficiency. Using a centrifugal pump as a case study, we perform a number of simulation-based experiments or probability Q volumetric flow T temperature r friction coefficient w wear parameter M model/submodel v
A Structural Model Guide For Geothermal Exploration In Ancestral...
A Structural Model Guide For Geothermal Exploration In Ancestral Mount Bao, Leyte, Philippines Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A...
Non-normality of Data in Structural Equation Models
Gao, Shengyi; Mokhtarian, Patricia L; Johnston, Robert A.
2008-01-01
J. F. Finch, and P. J. Curran. Structural equations models2, 1993, pp. 313-338. 16. Curran, P. J. , S. G. West, and J.appeared not to be useful. Curran et al. (16) compared the
Reduced Order Structural Modeling of Wind Turbine Blades
Jonnalagadda, Yellavenkatasunil
2011-10-21
Conventional three dimensional structural analysis methods prove to be expensive for the preliminary design of wind turbine blades. However, wind turbine blades are large slender members with complex cross sections. They can be accurately modeled...
On the Vacuum Structure of the 3-2 Model
Tomer Shacham
2012-05-27
The 3-2 model of dynamical supersymmetry breaking is revisited, with some incidentally new observations on the vacuum structure. Extra matter is then added, and the vacuum structure is further studied. The parametric dependence of the location of the vacuum provides a consistency check of Seiberg duality.
3-D Structural Modeling of Humic Acids through Experimental
Goddard III, William A.
for a "typical" soilHA.SchlutenandSchnitzer(11)havecombinedelemental analysis, 13C NMR, pyrolysis mass Structure Elucidation and Atomistic Simulations. 1. Chelsea Soil Humic Acid M A M A D O U S . D I A L L O to the CASE program SIGNATURE to generate all 3-D structural models for Chelsea soil humic acid (HA
MOLECULAR MODELING OF PROTEINS AND MATHEMATICAL PREDICTION OF PROTEIN STRUCTURE
Neumaier, Arnold
MOLECULAR MODELING OF PROTEINS AND MATHEMATICAL PREDICTION OF PROTEIN STRUCTURE ARNOLD NEUMAIERcalled protein folding problem. The static aspect is concerned with how to predict the folded (native, tertiary) structure of a protein, given its sequence of amino acids. The dynamic aspect asks about the possible
MOLECULAR MODELING OF PROTEINS AND MATHEMATICAL PREDICTION OF PROTEIN STRUCTURE
Neumaier, Arnold
MOLECULAR MODELING OF PROTEINS AND MATHEMATICAL PREDICTION OF PROTEIN STRUCTURE ARNOLD NEUMAIER-called protein folding problem. The static aspect is concerned with how to predict the folded (native, tertiary) structure of a protein, given its sequence of amino acids. The dynamic aspect asks about the possible
Modeling emergent large-scale structures of barchan dune fields
Claudin, Philippe
Modeling emergent large-scale structures of barchan dune fields S. Worman , A.B. Murray , R, barchan dunes typically exist as members of larger fields that display strik- ing, enigmatic structures that cannot be readily explained by examining the dynamics at the scale of single dunes, or by appealing
Structure Learning for Generative Models of Protein Fold Families
Structure Learning for Generative Models of Protein Fold Families Sivaraman Balakrishnan composition of the proteins within a fold family are widely used in science and engineering. Existing composition of the proteins within a fold family provide insights into the constraints that govern structure
Lattice Boltzmann Model for Electronic Structure Simulations
Mendoza, M; Succi, S
2015-01-01
Recently, a new connection between density functional theory and kinetic theory has been proposed. In particular, it was shown that the Kohn-Sham (KS) equations can be reformulated as a macroscopic limit of the steady-state solution of a suitable single-particle kinetic equation. By using a discrete version of this new formalism, the exchange and correlation energies of simple atoms and the geometrical configuration of the methane molecule were calculated accurately. Here, we discuss the main ideas behind the lattice kinetic approach to electronic structure computations, offer some considerations for prospective extensions, and also show additional numerical results, namely the geometrical configuration of the water molecule.
Lattice Boltzmann Model for Electronic Structure Simulations
M. Mendoza; H. J. Herrmann; S. Succi
2015-07-28
Recently, a new connection between density functional theory and kinetic theory has been proposed. In particular, it was shown that the Kohn-Sham (KS) equations can be reformulated as a macroscopic limit of the steady-state solution of a suitable single-particle kinetic equation. By using a discrete version of this new formalism, the exchange and correlation energies of simple atoms and the geometrical configuration of the methane molecule were calculated accurately. Here, we discuss the main ideas behind the lattice kinetic approach to electronic structure computations, offer some considerations for prospective extensions, and also show additional numerical results, namely the geometrical configuration of the water molecule.
Structure formation in modified gravity models alternative to dark energy
Kazuya Koyama
2006-01-10
We study structure formation in phenomenological models in which the Friedmann equation receives a correction of the form $H^{\\alpha}/r_c^{2-\\alpha}$, which realize an accelerated expansion without dark energy. In order to address structure formation in these model, we construct simple covariant gravitational equations which give the modified Friedmann equation with $\\alpha=2/n$ where $n$ is an integer. For $n=2$, the underlying theory is known as a 5D braneworld model (the DGP model). Thus the models interpolate between the DGP model ($n=2, \\alpha=1$) and the LCDM model in general relativity ($n \\to \\infty, \\alpha \\to 0$). Using the covariant equations, cosmological perturbations are analyzed. It is shown that in order to satisfy the Bianchi identity at a perturbative level, we need to introduce a correction term $E_{\\mu \
Structure formation in modified gravity models alternative to dark energy
Koyama, K
2006-01-01
We study structure formation in phenomenological models in which the Friedmann equation receives a correction of the form $H^{\\alpha}/r_c^{2-\\alpha}$, which realize an accelerated expansion without dark energy. In order to address structure formation in these model, we construct simple covariant gravitational equations which give the modified Friedmann equation with $\\alpha=2/n$ where $n$ is an integer. For $n=2$, the underlying theory is known as a 5D braneworld model (the DGP model). Thus the models interpolate between the DGP model ($n=2, \\alpha=1$) and the LCDM model in general relativity ($n \\to \\infty, \\alpha \\to 0$). Using the covariant equations, cosmological perturbations are analyzed. It is shown that in order to satisfy the Bianchi identity at a perturbative level, we need to introduce a correction term $E_{\\mu \
A covariant model for the nucleon spin structure
Ramalho, G
2015-01-01
We present the results of the covariant spectator quark model applied to the nucleon structure function $f(x)$ measured in unpolarized deep inelastic scattering, and the structure functions $g_1(x)$ and $g_2(x)$ measured in deep inelastic scattering using polarized beams and targets ($x$ is the Bjorken scaling variable). The nucleon is modeled by a valence quark-diquark structure with $S,P$ and $D$ components. The shape of the wave functions and the relative strength of each component are fixed by making fits to the deep inelastic scattering data for the structure functions $f(x)$ and $g_1(x)$. The model is then used to make predictions on the function $g_2(x)$ for the proton and neutron.
Model for dynamic self-assembled magnetic surface structures.
Belkin, M.; Glatz, A.; Snezhko, A.; Aranson, I. S.; Materials Science Division; Northwestern Univ.
2010-07-07
We propose a first-principles model for the dynamic self-assembly of magnetic structures at a water-air interface reported in earlier experiments. The model is based on the Navier-Stokes equation for liquids in shallow water approximation coupled to Newton equations for interacting magnetic particles suspended at a water-air interface. The model reproduces most of the observed phenomenology, including spontaneous formation of magnetic snakelike structures, generation of large-scale vortex flows, complex ferromagnetic-antiferromagnetic ordering of the snake, and self-propulsion of bead-snake hybrids.
Structure formation in a nonlocally modified gravity model
Park, Sohyun; Dodelson, Scott
2013-01-01
We study a nonlocally modified gravity model proposed by Deser and Woodard which gives an explanation for current cosmic acceleration. By deriving and solving the equations governing the evolution of the structure in the Universe, we show that this model predicts a pattern of growth that differs from standard general relativity (+dark energy) at the 10-30% level. These differences will be easily probed by the next generation of galaxy surveys, so the model should be tested shortly.
The Canonical Structure of Wess-Zumino-Witten Models
G. Papadopoulos; B. Spence
1992-04-30
The phase space of the Wess-Zumino-Witten model on a circle with target space a compact, connected, semisimple Lie group $G$ is defined and the corresponding symplectic form is given. We present a careful derivation of the Poisson brackets of the Wess-Zumino-Witten model. We also study the canonical structure of the supersymmetric and the gauged Wess-Zumino-Witten models.
A finite element model for transient thermal/structural analysis of large composite space structures
Lutz, James Delmar
1986-01-01
Composite Space Structures. (May 1986) James Delmar Lutz, B. S. , Texas A&M University Chairmen of Advisory Committee: Dr. David H. Allen Dr. Walter E. Haisler A finite element model is developed for predicting the transient thermal/structural response... of structures to be analyzed in order to simplify the heat load analysis. The first r estr iction applies to the geometry of struc- tures to be analyzed. An appropriate structure should be of open lattice-type construction and have highly repetitive...
3D HYBRID RAY-FD AND DWN-FD SEISMIC MODELING FOR SIMPLE MODELS CONTAINING COMPLEX LOCAL STRUCTURES
Cerveny, Vlastislav
3D HYBRID RAY-FD AND DWN-FD SEISMIC MODELING FOR SIMPLE MODELS CONTAINING COMPLEX LOCAL STRUCTURES local structure embedded in a large, but considerably simpler, regional structure. The hybrid modelling to compute the seismic wavefield due to the source and simple regional structure. The complex local structure
PHASE STRUCTURE OF TWISTED EGUCHI-KAWAI MODEL.
ISHIKAWA,T.; AZEYANAGI, T.; HANADA, M.; HIRATA, T.
2007-07-30
We study the phase structure of the four-dimensional twisted Eguchi-Kawai model using numerical simulations. This model is an effective tool for studying SU(N) gauge theory in the large-N limit and provides a nonperturbative formulation of the gauge theory on noncommutative spaces. Recently it was found that its Z{sub n}{sup 4} symmetry, which is crucial for the validity of this model, can break spontaneously in the intermediate coupling region. We investigate in detail the symmetry breaking point from the weak coupling side. Our simulation results show that the continuum limit of this model cannot be taken.
Advances on statistical/thermodynamical models for unpolarized structure functions
Trevisan, Luis A.; Mirez, Carlos; Tomio, Lauro
2013-03-25
During the eights and nineties many statistical/thermodynamical models were proposed to describe the nucleons' structure functions and distribution of the quarks in the hadrons. Most of these models describe the compound quarks and gluons inside the nucleon as a Fermi / Bose gas respectively, confined in a MIT bag with continuous energy levels. Another models considers discrete spectrum. Some interesting features of the nucleons are obtained by these models, like the sea asymmetries {sup -}d/{sup -}u and {sup -}d-{sup -}u.
The Unified Approach for Model Evaluation in Structural Equation Modeling
Pornprasertmanit, Sunthud
2014-08-31
hypothesized model M. The discrepancy (FM) between the two means and covariance matrices can be computed using Equation 1.1 (Kenny & McCoach, 2003): FM = tr { ? [?M] ?1 } ? log ? ? ?? [?M] ?1 ? ? ??N +[µ ?µM]? [?M]?1 [µ ?µM] , (1.1) where N is sample size. FM...- crepancy function is defined by Equation 1.2 (Browne & Cudeck, 1992; Satorra & Saris, 1985; Saris & Satorra, 1993): ?M = (N?1)FM. (1.2) That is, the discrepancy value can be calculated by dividing the chi-square value by sample size minus 1. Most fit...
Model for Dynamic Self-Assembled Magnetic Surface Structures
M. Belkin; A. Glatz; A. Snezhko; I. S. Aranson
2010-02-02
We propose a first-principles model for self-assembled magnetic surface structures on the water-air interface reported in earlier experiments \\cite{snezhko2,snezhko4}. The model is based on the Navier-Stokes equation for liquids in shallow water approximation coupled to Newton equations for interacting magnetic particles suspended on the water-air interface. The model reproduces most of the observed phenomenology, including spontaneous formation of magnetic snake-like structures, generation of large-scale vortex flows, complex ferromagnetic-antiferromagnetic ordering of the snake, and self-propulsion of bead-snake hybrids. The model provides valuable insights into self-organization phenomena in a broad range of non-equilibrium magnetic and electrostatic systems with competing interactions.
A STRUCTURAL-MAGNETIC STRAIN MODEL FOR MAGNETOSTRICTIVE TRANSDUCERS
strains and forces is provided by a magnetic bias generated by either the surrounding permanent magnet of a cylindrical Terfenol-D rod, a wound wire solenoid, an enclosing permanent magnet and a prestress mechanismA STRUCTURAL-MAGNETIC STRAIN MODEL FOR MAGNETOSTRICTIVE TRANSDUCERS Marcelo J. Dapino Department
Topological Structures of Cluster Spins for Ising Models
You-gang Feng
2010-03-19
We discussed hierarchies and rescaling rule of the self similar transformations in Ising models, and define a fractal dimension of an ordered cluster, which minimum corresponds to a fixed point of the transformations. By the fractal structures we divide the clusters into two types: irreducible and reducible. A relationship of cluster spin with its coordination number and fractal dimension is obtained.
Models for Offender Target Location Selection with Explicit Dependency Structures
O'Leary, Michael
Models for Offender Target Location Selection with Explicit Dependency Structures Mike O'Leary April 30 - May 1, 2012 O'Leary & Tucker (Towson University) Target Location Selection QMDNS 2012 1 / 54 in this study We thank Phil Canter from the Baltimore County Police Department for his assistance. O'Leary
Modeling Blast Loading on Buried Reinforced Concrete Structures with Zapotec
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Bessette, Greg C.
2008-01-01
A coupled Euler-Lagrange solution approach is used to model the response of a buried reinforced concrete structure subjected to a close-in detonation of a high explosive charge. The coupling algorithm is discussed along with a set of benchmark calculations involving detonations in clay and sand.
A Scalable Approach to Learn Semantic Models of Structured Sources
Ambite, José Luis
of information available on the Web is available in sources such as relational databases, spreadsheets, XML, JSON concepts and relationships within a domain, and source descriptions are formal specifications of semanticA Scalable Approach to Learn Semantic Models of Structured Sources Mohsen Taheriyan, Craig A
Comparison of {gamma}Z-structure function models
Rislow, Benjamin C.
2013-11-01
The {gamma}Z-box is an important contribution to the proton's weak charge. The {gamma}Z-box is calculated dispersively and depends on {gamma}Z-structure functions, F{sub {gamma}Z1,2,3}(x,Q{sup 2}) . At present there is no data for these structure functions and they must be modeled by modifying existing fits to electromagnetic data. Each group that has studied the {gamma}Z-box used different modifications. The results of the PVDIS experiment at Jefferson Lab may provide a first test of the validity of each group's models. I present details of the different models and their predictions for the PVDIS result.
Structural Design Composition for C++ Hardware Models Frederic Doucet, Vivek Sinha, Rajesh Gupta
Gupta, Rajesh
Structural Design Composition for C++ Hardware Models Frederic Doucet, Vivek Sinha, Rajesh Gupta design to specify these structural concerns. 1. Introduction High level modeling using C/C++ models [11,vsinha,rguptag@ics.uci.edu Abstract This paper addresses the modeling of layout structure in high level C++ models. Researchers agree
Model comparison for the density structure across solar coronal waveguides
Arregui, I; Ramos, A Asensio
2015-01-01
The spatial variation of physical quantities, such as the mass density, across solar atmospheric waveguides governs the timescales and spatial scales for wave damping and energy dissipation. The direct measurement of the spatial distribution of density, however, is difficult and indirect seismology inversion methods have been suggested as an alternative. We applied Bayesian inference, model comparison, and model-averaging techniques to the inference of the cross-field density structuring in solar magnetic waveguides using information on periods and damping times for resonantly damped magnetohydrodynamic (MHD) transverse kink oscillations. Three commonly employed alternative profiles were used to model the variation of the mass density across the waveguide boundary. Parameter inference enabled us to obtain information on physical quantities such as the Alfv\\'en travel time, the density contrast, and the transverse inhomogeneity length scale. The inference results from alternative density models were compared a...
Song, Il-Yeol
Model (ERM) and the conceptual basis of the data modeling technique used by the SAP Corporation, Conceptual Data Model, Entity Relationship Model (ERM), Structured Entity Relationship Model (SERM), Star
Crystal Structure Representations for Machine Learning Models of Formation Energies
Faber, Felix; von Lilienfeld, O Anatole; Armiento, Rickard
2015-01-01
We introduce and evaluate a set of feature vector representations of crystal structures for machine learning (ML) models of formation energies of solids. ML models of atomization energies of organic molecules have been successful using a Coulomb matrix representation of the molecule. We consider three ways to generalize such representations to periodic systems: (i) a matrix where each element is related to the Ewald sum of the electrostatic interaction between two different atoms in the unit cell repeated over the lattice; (ii) an extended Coulomb-like matrix that takes into account a number of neighboring unit cells; and (iii) an Ansatz that mimics the periodicity and the basic features of the elements in the Ewald sum matrix by using a sine function of the crystal coordinates of the atoms. The representations are compared for a Laplacian kernel with Manhattan norm, trained to reproduce formation energies using a data set of 3938 crystal structures obtained from the Materials Project. For training sets consi...
Structure formation and CMBR anisotropy spectrum in the inflessence model
A. A. Sen; V. F. Cardone; S. Capozziello; A. Troisi
2006-07-25
The inflessence model has recently been proposed in an attempt to explain both early inflation and present day accelerated expansion within a single mechanism. The model has been successfully tested against the Hubble diagram of Type Ia Supernovae, the shift parameter, and the acoustic peak parameter. As a further mandatory test, we investigate here structure formation in the inflessence model determining the evolution of matter density contrast $\\delta \\equiv \\delta \\rho_M/\\rho_M$ in the linear regime. We compare the growth factor $D(a) \\equiv \\delta/a$ and the growth index $f(z) \\equiv d\\ln{\\delta}/d\\ln{a}$ to these same quantities for the successful concordance $\\Lambda$CDM model with a particular emphasis on the role of the inflessence parameters $(\\gamma, z_Q)$. We also evaluate the anisotropy spectrum of the cosmic microwave background radiation (CMBR) to check whether the inflessence model may be in agreement with the observations. We find that, for large values of $(\\gamma, z_Q)$, structure formation proceeds in a similar way to that in the $\\Lambda$CDM scenario, and it is also possible to nicely fit the CMBR spectrum.
Structure formation in inhomogeneous Early Dark Energy models
Batista, R.C. [Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte, Caixa Postal 1524, 59072-970, Natal, Rio Grande do Norte (Brazil); Pace, F., E-mail: rbatista@ect.ufrn.br, E-mail: francesco.pace@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth, PO1 3FX (United Kingdom)
2013-06-01
We study the impact of Early Dark Energy fluctuations in the linear and non-linear regimes of structure formation. In these models the energy density of dark energy is non-negligible at high redshifts and the fluctuations in the dark energy component can have the same order of magnitude of dark matter fluctuations. Since two basic approximations usually taken in the standard scenario of quintessence models, that both dark energy density during the matter dominated period and dark energy fluctuations on small scales are negligible, are not valid in such models, we first study approximate analytical solutions for dark matter and dark energy perturbations in the linear regime. This study is helpful to find consistent initial conditions for the system of equations and to analytically understand the effects of Early Dark Energy and its fluctuations, which are also verified numerically. In the linear regime we compute the matter growth and variation of the gravitational potential associated with the Integrated Sachs-Wolf effect, showing that these observables present important modifications due to Early Dark Energy fluctuations, though making them more similar to the ?CDM model. We also make use of the Spherical Collapse model to study the influence of Early Dark Energy fluctuations in the nonlinear regime of structure formation, especially on ?{sub c} parameter, and their contribution to the halo mass, which we show can be of the order of 10%. We finally compute how the number density of halos is modified in comparison to the ?CDM model and address the problem of how to correct the mass function in order to take into account the contribution of clustered dark energy. We conclude that the inhomogeneous Early Dark Energy models are more similar to the ?CDM model than its homogeneous counterparts.
Scaling issues associated with thermal and structural modeling and testing
Thomas, R.K.; Moya, J.L.; Skocypec, R.D.
1993-10-01
Sandia National Laboratories (SNL) is actively engaged in research to characterize abnormal environments, and to improve our capability to accurately predict the response of engineered systems to thermal and structural events. Abnormal environments, such as impact and fire, are complex and highly nonlinear phenomena which are difficult to model by computer simulation. Validation of computer results with full scale, high fidelity test data is required. The number of possible abnormal environments and the range of initial conditions are very large. Because full-scale tests are very costly, only a minimal number have been conducted. Scale model tests are often performed to span the range of abnormal environments and initial conditions unobtainable by full-scale testing. This paper will discuss testing capabilities at SNL, issues associated with thermal and structural scaling, and issues associated with extrapolating scale model data to full-scale system response. Situated a few minutes from Albuquerque, New Mexico, are the unique test facilities of Sandia National Laboratories. The testing complex is comprised of over 40 facilities which occupy over 40 square miles. Many of the facilities have been designed and built by SNL to simulate complex problems encountered in engineering analysis and design. The facilities can provide response measurements, under closely controlled conditions, to both verify mathematical models of engineered systems and satisfy design specifications.
Ultrafast Structural Dynamics in Combustion Relevant Model Systems
Weber, Peter M.
2014-03-31
The research project explored the time resolved structural dynamics of important model reaction system using an array of novel methods that were developed specifically for this purpose. They include time resolved electron diffraction, time resolved relativistic electron diffraction, and time resolved Rydberg fingerprint spectroscopy. Toward the end of the funding period, we also developed time-resolved x-ray diffraction, which uses ultrafast x-ray pulses at LCLS. Those experiments are just now blossoming, as the funding period expired. In the following, the time resolved Rydberg Fingerprint Spectroscopy is discussed in some detail, as it has been a very productive method. The binding energy of an electron in a Rydberg state, that is, the energy difference between the Rydberg level and the ground state of the molecular ion, has been found to be a uniquely powerful tool to characterize the molecular structure. To rationalize the structure sensitivity we invoke a picture from electron diffraction: when it passes the molecular ion core, the Rydberg electron experiences a phase shift compared to an electron in a hydrogen atom. This phase shift requires an adjustment of the binding energy of the electron, which is measurable. As in electron diffraction, the phase shift depends on the molecular, geometrical structure, so that a measurement of the electron binding energy can be interpreted as a measurement of the molecule’s structure. Building on this insight, we have developed a structurally sensitive spectroscopy: the molecule is first elevated to the Rydberg state, and the binding energy is then measured using photoelectron spectroscopy. The molecule’s structure is read out as the binding energy spectrum. Since the photoionization can be done with ultrafast laser pulses, the technique is inherently capable of a time resolution in the femtosecond regime. For the purpose of identifying the structures of molecules during chemical reactions, and for the analysis of molecular species in the hot environments of combustion processes, there are several features that make the Rydberg ionization spectroscopy uniquely useful. First, the Rydberg electron’s orbit is quite large and covers the entire molecule for most molecular structures of combustion interest. Secondly, the ionization does not change vibrational quantum numbers, so that even complicated and large molecules can be observed with fairly well resolved spectra. In fact, the spectroscopy is blind to vibrational excitation of the molecule. This has the interesting consequence for the study of chemical dynamics, where the molecules are invariably very energetic, that the molecular structures are observed unobstructed by the vibrational congestion that dominates other spectroscopies. This implies also that, as a tool to probe the time-dependent structural dynamics of chemically interesting molecules, Rydberg spectroscopy may well be better suited than electron or x-ray diffraction. With recent progress in calculating Rydberg binding energy spectra, we are approaching the point where the method can be evolved into a structure determination method. To implement the Rydberg ionization spectroscopy we use a molecular beam based, time-resolved pump-probe multi-photon ionization/photoelectron scheme in which a first laser pulse excites the molecule to a Rydberg state, and a probe pulse ionizes the molecule. A time-of-flight detector measures the kinetic energy spectrum of the photoelectrons. The photoelectron spectrum directly provides the binding energy of the electron, and thereby reveals the molecule’s time-dependent structural fingerprint. Only the duration of the laser pulses limits the time resolution. With a new laser system, we have now reached time resolutions better than 100 fs, although very deep UV wavelengths (down to 190 nm) have slightly longer instrument functions. The structural dynamics of molecules in Rydberg-excited states is obtained by delaying the probe ionization photon from the pump photon; the structural dynamics of molecules in their ground state or e
Nonlinear structure formation in the cubic Galileon gravity model
Barreira, Alexandre; Li, Baojiu; Hellwing, Wojciech A.; Baugh, Carlton M.; Pascoli, Silvia E-mail: baojiu.li@durham.ac.uk E-mail: c.m.baugh@durham.ac.uk
2013-10-01
We model the linear and nonlinear growth of large scale structure in the Cubic Galileon gravity model, by running a suite of N-body cosmological simulations using the ECOSMOG code. Our simulations include the Vainshtein screening effect, which reconciles the Cubic Galileon model with local tests of gravity. In the linear regime, the amplitude of the matter power spectrum increases by ? 20% with respect to the standard ?CDM model today. The modified expansion rate accounts for ? 15% of this enhancement, while the fifth force is responsible for only ? 5%. This is because the effective unscreened gravitational strength deviates from standard gravity only at late times, even though it can be twice as large today. In the nonlinear regime (k?>0.1h Mpc{sup ?1}), the fifth force leads to only a modest increase (?<8%) in the clustering power on all scales due to the very efficient operation of the Vainshtein mechanism. Such a strong effect is typically not seen in other models with the same screening mechanism. The screening also results in the fifth force increasing the number density of halos by less than 10%, on all mass scales. Our results show that the screening does not ruin the validity of linear theory on large scales which anticipates very strong constraints from galaxy clustering data. We also show that, whilst the model gives an excellent match to CMB data on small angular scales (l?>50), the predicted integrated Sachs-Wolfe effect is in tension with Planck/WMAP results.
Hybrid Structural Model of the Complete Human ESCRT-0 Complex
Ren, Xuefeng; Kloer, Daniel P.; Kim, Young C.; Ghirlando, Rodolfo; Saidi, Layla F.; Hummer, Gerhard; Hurley, James H.; (NIH)
2009-03-31
The human Hrs and STAM proteins comprise the ESCRT-0 complex, which sorts ubiquitinated cell surface receptors to lysosomes for degradation. Here we report a model for the complete ESCRT-0 complex based on the crystal structure of the Hrs-STAM core complex, previously solved domain structures, hydrodynamic measurements, and Monte Carlo simulations. ESCRT-0 expressed in insect cells has a hydrodynamic radius of R{sub H} = 7.9 nm and is a 1:1 heterodimer. The 2.3 {angstrom} crystal structure of the ESCRT-0 core complex reveals two domain-swapped GAT domains and an antiparallel two-stranded coiled-coil, similar to yeast ESCRT-0. ESCRT-0 typifies a class of biomolecular assemblies that combine structured and unstructured elements, and have dynamic and open conformations to ensure versatility in target recognition. Coarse-grained Monte Carlo simulations constrained by experimental R{sub H} values for ESCRT-0 reveal a dynamic ensemble of conformations well suited for diverse functions.
A 'BOOSTED FIREBALL' MODEL FOR STRUCTURED RELATIVISTIC JETS
Duffell, Paul C.; MacFadyen, Andrew I., E-mail: pcd233@nyu.edu, E-mail: macfadyen@nyu.edu [Center for Cosmology and Particle Physics, New York University, NY (United States)
2013-10-10
We present a model for relativistic jets which generates a particular angular distribution of Lorentz factor and energy per solid angle. We consider a fireball with specific internal energy E/M launched with bulk Lorentz factor ? {sub B}. In its center-of-momentum frame the fireball expands isotropically, converting its internal energy into radially expanding flow with asymptotic Lorentz factor ?{sub 0} ? E/M. In the lab frame the flow is beamed, expanding with Lorentz factor ? = 2?{sub 0}? {sub B} in the direction of its initial bulk motion and with characteristic opening angle ?{sub 0} ? 1/? {sub B}. The flow is jet-like with ??{sub 0} ? 2?{sub 0} such that jets with ? > 1/?{sub 0} are naturally produced. The choice ?{sub 0} ? ? {sub B} ? 10 yields a jet with ? ? 200 on-axis and angular structure characterized by opening angle ?{sub 0} ? 0.1 of relevance for cosmological gamma-ray bursts (GRBs), while ? {sub B} ?> 1 may be relevant for low-luminosity GRBs. The model produces a family of outflows, of relevance for different relativistic phenomena with structures completely determined by ?{sub 0} and ? {sub B}. We calculate the energy per unit solid angle for the model and use it to compute light curves for comparison with the widely used top-hat model. The jet break in the boosted fireball light curve is greatly subdued when compared to the top-hat model because the edge of the jet is smoother than for a top-hat. This may explain missing jet breaks in afterglow light curves.
NMR Structures of Salt-Refolded Forms of the 434-Repressor DNA-Binding Domain in 6 M Urea
Wider, Gerhard
NMR Structures of Salt-Refolded Forms of the 434-Repressor DNA-Binding Domain in 6 M Urea- 8). Examples are salt-induced refolding of proteins at acidic pH (9), leading to the formation), and lysozyme (14) allowed detailed structural and dynamic characterization of salt-stabilized A-states, which
Dynamic soil-structure interaction-comparison of FEM model with experimental results
Srinivasan, Palanivel Rajan
2000-01-01
Linearly elastic finite element models are developed for particular scale-model gravity retaining wall structures. The sand is modeled as a homogenous isotropic linearly elastic continuum. Models are created in four different configurations...
Phase structure in a chiral model of nuclear matter
Phat, Tran Huu; Anh, Nguyen Tuan; Tam, Dinh Thanh
2011-08-15
The phase structure of symmetric nuclear matter in the extended Nambu-Jona-Lasinio (ENJL) model is studied by means of the effective potential in the one-loop approximation. It is found that chiral symmetry gets restored at high nuclear density and a typical first-order phase transition of the liquid-gas transition occurs at zero temperature, T=0, which weakens as T grows and eventually ends up with a second-order critical point at T=20 MeV. This phase transition scenario is confirmed by investigating the evolution of the effective potential versus the effective nucleon mass and the equation of state.
Global stability of an age-structure model for TB and its applications ...
1998-07-14
pendent transmission rates on a model for TB dynamics in a population with or without a vaccination program. The formulation of an age-structure model for.
Modeling and Design of RF MEMS Structures Using Computationally Efficient Numerical Techniques
Tentzeris, Manos
Modeling and Design of RF MEMS Structures Using Computationally Efficient Numerical Techniques N. A Abstract The modeling of MEMS structures using MRTD is presented. Many complex RF structures have been communication systems efficiently and accurately. Specifically, micromachined structures such as MEMS
Large scale structure simulations of inhomogeneous LTB void models
David Alonso; Juan Garcia-Bellido; Troels Haugboelle; Julian Vicente
2011-01-11
We perform numerical simulations of large scale structure evolution in an inhomogeneous Lemaitre-Tolman-Bondi (LTB) model of the Universe. We follow the gravitational collapse of a large underdense region (a void) in an otherwise flat matter-dominated Einstein-deSitter model. We observe how the (background) density contrast at the centre of the void grows to be of order one, and show that the density and velocity profiles follow the exact non-linear LTB solution to the full Einstein equations for all but the most extreme voids. This result seems to contradict previous claims that fully relativistic codes are needed to properly handle the non-linear evolution of large scale structures, and that local Newtonian dynamics with an explicit expansion term is not adequate. We also find that the (local) matter density contrast grows with the scale factor in a way analogous to that of an open universe with a value of the matter density OmegaM(r) corresponding to the appropriate location within the void.
The growth of structure in interacting dark energy models
Caldera-Cabral, Gabriela; Maartens, Roy; Schaefer, Bjoern Malte E-mail: roy.maartens@port.ac.uk
2009-07-01
If dark energy interacts with dark matter, there is a change in the background evolution of the universe, since the dark matter density no longer evolves as a{sup ?3}. In addition, the non-gravitational interaction affects the growth of structure. In principle, these changes allow us to detect and constrain an interaction in the dark sector. Here we investigate the growth factor and the weak lensing signal for a new class of interacting dark energy models. In these models, the interaction generalises the simple cases where one dark fluid decays into the other. In order to calculate the effect on structure formation, we perform a careful analysis of the perturbed interaction and its effect on peculiar velocities. Assuming a normalization to today's values of dark matter density and overdensity, the signal of the interaction is an enhancement (suppression) of both the growth factor and the lensing power, when the energy transfer in the background is from dark matter to dark energy (dark energy to dark matter)
A Deep Learning Model for Structured Outputs with High-order Interaction
Toronto, University of
A Deep Learning Model for Structured Outputs with High-order Interaction Hongyu Guo , Xiaodan Zhu to generate a powerful nonlinear functional mapping from structured input to structured output. More nonlinear functional mapping from high-order structured input to high-order structured output. To this end
Geometrical model for malaria parasite migration in structured environments
Anna Battista; Friedrich Frischknecht; Ulrich S. Schwarz
2014-10-23
Malaria is transmitted to vertebrates via a mosquito bite, during which rod-like and crescent-shaped parasites, called sporozoites, are injected into the skin of the host. Searching for a blood capillary to penetrate, sporozoites move quickly in locally helical trajectories, that are frequently perturbed by interactions with the extracellular environment. Here we present a theoretical analysis of the active motility of sporozoites in a structured environment. The sporozoite is modelled as a self-propelled rod with spontaneous curvature and bending rigidity. It interacts with hard obstacles through collision rules inferred from experimental observation of two-dimensional sporozoite movement in pillar arrays. Our model shows that complex motion patterns arise from the geometrical shape of the parasite and that its mechanical flexibility is crucial for stable migration patterns. Extending the model to three dimensions reveals that a bent and twisted rod can associate to cylindrical obstacles in a manner reminiscent of the association of sporozoites to blood capillaries, supporting the notion of a prominent role of cell shape during malaria transmission.
On electromagnetic models of ball lightning with topological structure
Donoso, J M; Trueba, J L
2003-01-01
It has been long admitted that a consequence of the virial theorem is that there can be no equilibrium configurations of a system of charges in electromagnetic interaction in the absence of external forces. However, recent results have shown that the virial theorem can not preclude the existence of certain nontrivial equilibrium configurations. Although some of these new results are based on an effective microscopic field theory, they are important for a theory of ball lightning that has been developed by the authors of the present work. Other theoretical results relative to magnetic force-free fields with field aligned currents and self-organized filamentary structures are also found to be relevant for this model.
Buldyrev, Sergey
Fluid transport in branched structures with temporary closures: A model for quasistatic lung a model system relevant to the inflation of a mammalian lung, an asymmetric bifurcating structure description of the underlying branching structure of the lung, by analyzing experimental pressure-volume data
Heaton, Thomas H.
2006-01-01
practical for health monitoring of real structures. The approach also inherits the advantages of Bayesian in structural health monitoring (Natke and Yao, 1988; Hjelmstad and Shin, 1997; Lam et al., 1998; Beck et al of structural health monitoring, linear struc- tural models are often used for model updating (Vanik et al
structure in Lake Michigan: spring thermal bar, full stratification, deepening of the thermocline duringModeling circulation and thermal structure in Lake Michigan: Annual cycle and interannual and thermal structure in the lake. The model was able to reproduce all of the basic features of the thermal
Wu, Jiun-Yu
2011-10-21
researcher can either use the ad-hoc robust sandwich standard error estimators to correct the standard error estimates (Design-based approach) or perform multilevel analysis to model the multilevel data structure (Model-based approach) to analyze dependent...
METHODOLOGY ARTICLE Open Access Quality assessment of protein model-structures
Nebel, Jean-Christophe
METHODOLOGY ARTICLE Open Access Quality assessment of protein model-structures based on structural Background: Experimental determination of protein 3D structures is expensive, time consuming and sometimes impossible. A gap between number of protein structures deposited in the World Wide Protein Data Bank
A Structure-Conveying Modelling Language for Mathematical and Stochastic Programming
Grothey, Andreas
A Structure-Conveying Modelling Language for Mathematical and Stochastic Programming Marco Colombo present a structure-conveying algebraic modelling language for mathematical pro- gramming. The proposed language extends AMPL with object-oriented features that allows the user to construct models from sub
THE DYNAMICAL STRUCTURE FACTOR AND CRITICAL BEHAVIOR OF A TRAFFIC FLOW MODEL
Lübeck, Sven
261 THE DYNAMICAL STRUCTURE FACTOR AND CRITICAL BEHAVIOR OF A TRAFFIC FLOW MODEL L. ROTERS, S. L. The behavior of the model is determined by three parameters, the maximal velocity v max , the noise parameter P of the dynamical structure factor of the Nagel Schreckenberg traffic flow model based on the local occupation
Myers, Natasha
2007-01-01
This ethnography tracks visualization and pedagogy in the burgeoning field of structural biology. Structural biologists are a multidisciplinary group of researchers who produce models and animations of protein molecules ...
CONTROL-ORIENTED MODELING OF A SOLID-OXIDE FUEL CELL STACK USING AN LPV MODEL STRUCTURE
Sanandaji, Borhan M.
CONTROL-ORIENTED MODELING OF A SOLID-OXIDE FUEL CELL STACK USING AN LPV MODEL STRUCTURE Borhan M. Sanandaji, Tyrone L. Vincent, Andrew Colclasure, and Robert J. Kee Colorado Fuel Cell Center Engineering dynamic model of a solid oxide fuel cell stack. Using a detailed physical model as a starting point, we
Sigma models with off-shell N=(4,4) supersymmetry and noncommuting complex structures
M. Goteman; U. Lindstrom; M. Rocek; Itai Ryb
2010-05-02
We describe the conditions for extra supersymmetry in N=(2,2) supersymmetric nonlinear sigma models written in terms of semichiral superfields. We find that some of these models have additional off-shell supersymmetry. The (4,4) supersymmetry introduces geometrical structures on the target-space which are conveniently described in terms of Yano f-structures and Magri-Morosi concomitants. On-shell, we relate the new structures to the known bi-hypercomplex structures.
Poggiale, Jean-Christophe
Modeling environmental effects on the size-structured energy flow through marine ecosystems. Part 1 size-structured mathematical model of the energy flow through marine ecosystems, based on established the dynamic size-spectrum of marine ecosystems in term of energy con- tent per weight class as well as many
Modeling Structural Changes in Market Demand and Supply
Park, Beom Su
2011-10-21
Economic events may cause structural changes in markets. To know the effect of the economic event we should analyze the structural changes in the market demand and supply. The purpose of this dissertation is to analyze the ...
Optimal standoff imaging using structured laser illumination and graphical models
Hardy, Nicholas D. (Nicholas David)
2014-01-01
Structured illumination can be used to form images without using a lens or a detector array. A series of spatially-structured laser pulses is cast on the scene of interest, and a single-detector power measurement is made ...
Microscale and mesoscale discrete models for dynamic fracture of structures built of brittle are derived either at microscale with random distribution of material properties or at a mesoscale
On a tensor-based finite element model for the analysis of shell structures
Arciniega Aleman, Roman Augusto
2006-04-12
In the present study, we propose a computational model for the linear and nonlinear analysis of shell structures. We consider a tensor-based finite element formulation which describes the mathematical shell model in a ...
Trees and beyond : exploiting and improving tree-structured graphical models
Choi, Myung Jin, Ph. D. Massachusetts Institute of Technology
2011-01-01
Probabilistic models commonly assume that variables are independent of each other conditioned on a subset of other variables. Graphical models provide a powerful framework for encoding such conditional independence structure ...
A Hidden Markov Chain Model for the Term Structure of Bond Credit Risk Spreads
Thomas, L; Allen, David E; Morkel-Kingsbury, N
1998-01-01
This paper provides a Markov chain model for the term structure and credit risk spreads of bond processes. It allows dependency between the stochastic process modeling the interest rate and the Markov chain process describing ...
Modeling Elasto-Plastic Behavior of Polycrystalline Grain Structure of Steels at Mesoscopic Level
Cizelj, Leon
Modeling Elasto-Plastic Behavior of Polycrystalline Grain Structure of Steels at Mesoscopic Level. The constitutive model of crystal grains utilizes anisotropic elasticity and crystal plasticity. Commercially be considered macroscopically homogeneous. Elastic and rate independent plastic deformation modes are considered
Baglioni, P [University of Florence; Chen, Wei-Ren [ORNL; Falus, Peter [ORNL; Faraone, Antonio [National Institute of Standards and Technology (NIST); Fratini, Emiliano [University of Florence; Hong, Kunlun [ORNL; Liu, Yun [National Institute of Standards and Technology (NIST); Porcar, L. [National Institute of Standards and Technology (NIST)
2012-01-01
Recently experiments that combine both small angle neutron scattering (SANS) and Neutron Spin Echo (NSE) have demonstrated that dynamic clusters can form in concentrated lysozyme solutions when there is a right combination of a short-ranged attraction and a long-ranged electrostatic repulsion. In this paper, we study the temperature effect on the dynamic cluster formation and try to pinpoint the transition concentration from a monomer phase to a cluster phase. Interestingly at even a relatively high concentration (10 % mass fraction), despite the significant change of the SANS patterns that are associated with the change of the short-ranged attraction among proteins, the normalized short-time self-diffusion coefficient is not affected. This is interpreted due to the fact that there is no cluster formation at this condition. However, at larger concentrations such as 17.5 % and 22.5 % mass fraction, we show that the average hydrodynamic radius increase significantly and causes a large decrease of the normalized self-diffusion coefficient when the temperature is changed from 25 oC to 5 oC indicating the formation of dynamic clusters in solution.
A Coupled StructuralMagnetic Strain Model for Magnetostrictive Transducers
for generation of strains in smart structure systems motivates the development of increasingly accurate motivated by the need for increased levels of adaptability in smart structure systems. In this paper, we, such transducer systems are capable of providing both actuation, characterized by magnetictoelastic energy trans
Mixed Membership Models for Rank Data: Investigating Structure in Irish Voting Data
Wolfe, Patrick J.
the population. Thus, mixed membership models provide a method for model-based soft clustering of data. The mixed21 Mixed Membership Models for Rank Data: Investigating Structure in Irish Voting Data Isobel ........................................................................ 444 21.3.1 The Plackett-Luce Model for Rank Data ............................................ 445 21
Modelling the mechanical interaction between flowing materials and retaining wire structures
Gagliardini, Olivier
Modelling the mechanical interaction between flowing materials and retaining wire structures Franc Sols Solides Structures, UJF-INPG-CNRS, Grenoble, France Received 10 March 2004; received in revised, design of structural elements may require analysing the mechanical interac- tion between a flowing
Giurgiutiu, Victor
Structural health monitoring with piezoelectric wafer active sensors predictive modeling of the state of the art in structural health monitoring with piezoelectric wafer active sensors and follows with conclusions and suggestions for further work Key Words: structural health monitoring, SHM, nondestructive
FINITE WAVELET DOMAIN METHOD FOR EFFICIENT MODELING OF LAMB WAVE BASED STRUCTURAL HEALTH MONITORING
Paris-Sud XI, Université de
FINITE WAVELET DOMAIN METHOD FOR EFFICIENT MODELING OF LAMB WAVE BASED STRUCTURAL HEALTH MONITORING of innovative Structural Health Monitoring (SHM) methods and systems. Of particular importance is the design European Workshop on Structural Health Monitoring July 8-11, 2014. La Cité, Nantes, France Copyright
FINITE ELEMENT MODEL-BASED STRUCTURAL HEALTH MONITORING (SHM) SYSTEMS FOR COMPOSITE MATERIAL UNDER
Paris-Sud XI, Université de
FINITE ELEMENT MODEL-BASED STRUCTURAL HEALTH MONITORING (SHM) SYSTEMS FOR COMPOSITE MATERIAL UNDER). To design a Structural Health Monitoring (SHM) system, it is important to understand phenomenologically Workshop on Structural Health Monitoring July 8-11, 2014. La Cité, Nantes, France Copyright © Inria (2014
Structural Context of Exons in Protein Domains: Implications for Protein Modelling and Design
Moreira, Bruno Contreras
Structural Context of Exons in Protein Domains: Implications for Protein Modelling and Design Bruno structures taken from the Protein Data Bank. A first analysis of this set of proteins shows that intron boundaries prefer to be in non-regular secondary structure elements, while avoiding a-helices and b
Lee, Jooyoung
Random Forest-Based Protein Model Quality Assessment (RFMQA) Using Structural Features and Potential Energy Terms Balachandran Manavalan, Juyong Lee, Jooyoung Lee* Center for In Silico Protein in protein structure prediction. In this study, we present the first application of random forest based model
Cellulose Biodegradation Models; An Example of Cooperative Interactions in Structured Populations
Miroshnikov, Alexey
Cellulose Biodegradation Models; An Example of Cooperative Interactions in Structured Populations Pierre-Emmanuel Jabin Alexey Miroshnikov Robin Young Abstract We introduce various models for cellulose the structure of the cellulose chains and are allowed to depend on the phenotypical traits of the population
A STRUCTURAL MODEL FOR ELECTRICITY PRICES RENE CARMONA, MICHAEL COULON, AND DANIEL SCHWARZ
Carmona, Rene
A STRUCTURAL MODEL FOR ELECTRICITY PRICES RENE CARMONA, MICHAEL COULON, AND DANIEL SCHWARZ Abstract. In this paper we propose a new and highly tractable structural approach to spot price modeling and derivative pricing in electricity markets, thus extending the growing branch of liter- ature which describes power
J. Jeknic-Dugic; M. Dugic; A. Francom
2013-08-13
We observe a Quantum Brownian Motion (QBM) Model Universe in conjunction with recently established Entanglement Relativity and Parallel Occurrence of Decoherence. The Parallel Occurrence of Decoherence establishes the simultaneous occurrence of decoherence for two mutually irreducible structures (decomposition into subsystems) of the total QBM model universe. First we find that Everett world branching for one structure excludes branching for the alternate structure and in order to reconcile this situation branching cannot be allowed for either of the structures considered. Second, we observe the non-existence of a third, "emergent structure", that could approximate both structures and also be allowed to branch. Ultimately we find unless world-branching requires additional criteria or conditions, or there is a privileged structure, that we provide a valid model that cannot be properly described by the Everett Interpretation of Quantum Mechanics.
Attachment working models and false recall: a category structure approach
Wilson, Carol Leigh
2009-06-02
Two studies were conducted to test the central hypothesis that internal working models of attachment will influence false memory in a model-congruent pattern. Participants in both studies were first primed with a relationship-specific attachment...
Modeling the structure of coal water slurry (CWS) sprays
Prithiviraj, Manikandan
1993-01-01
This thesis describes a model of coal water slurry (CWS) sprays and presents new experimental data for CWS viscosities. The model is based on the aerodynamic theory of spray atomization which has been successfully used ...
Discovering linguistic structures in speech : models and applications
Lee, Chia-ying (Chia-ying Jackie)
2014-01-01
The ability to infer linguistic structures from noisy speech streams seems to be an innate human capability. However, reproducing the same ability in machines has remained a challenging task. In this thesis, we address ...
Conditional Graphical Models for Protein Structural Motif Recognition
Liu, Yan
Determining protein structures is crucial to understanding the mechanisms of infection and designing drugs. However, the elucidation of protein folds by crystallographic experiments can be a bottleneck in the development ...
Causes and explanations: A structural-model approach
J.Y. Halpern; Judea Pearl
2011-01-01
J. Y. and J. Pearl (2000). Causes and expla- nations: AJ. Y. and J. Pearl (2001). Causes and explana- tions: AR-266-UAI June 2001 Causes and Explanations: A Structural-
Spectral/hp Finite Element Models for Fluids and Structures
Payette, Gregory
2012-07-16
for the numerical simulation of the fully geometrically nonlinear mechanical response of isotropic, laminated composite and functionally graded elastic shell structures. In addition, we also present a simple and efficient sparse global finite element coefficient...
Experimentally validated finite element model of electrocaloric multilayer ceramic structures
Smith, N. A. S. E-mail: maciej.rokosz@npl.co.uk Correia, T. M. E-mail: maciej.rokosz@npl.co.uk; Rokosz, M. K. E-mail: maciej.rokosz@npl.co.uk
2014-07-28
A novel finite element model to simulate the electrocaloric response of a multilayer ceramic capacitor (MLCC) under real environment and operational conditions has been developed. The two-dimensional transient conductive heat transfer model presented includes the electrocaloric effect as a source term, as well as accounting for radiative and convective effects. The model has been validated with experimental data obtained from the direct imaging of MLCC transient temperature variation under application of an electric field. The good agreement between simulated and experimental data, suggests that the novel experimental direct measurement methodology and the finite element model could be used to support the design of optimised electrocaloric units and operating conditions.
A MODEL FOR PHYLOGENETIC INFERENCE USING STRUCTURAL AND CHEMICAL COVARIATES
Naylor, Gavin
in DNA sequence data was homogeneous across different classes of base pairs. DNA sequences for eight among all genes. A stochastic model of rate variation based on the interaction of the covariates. These results confirm that there are classes of base pairs that evolve differently, and suggest that models
A Model of Electrodiffusion and Osmotic Water Flow and its Energetic Structure
Ciocan-Fontanine, Ionut
A Model of Electrodiffusion and Osmotic Water Flow and its Energetic Structure Yoichiro Moria 60612, U.S.A. Abstract We introduce a model for ionic electrodiffusion and osmotic water flow through are dissipated through viscous, electrodiffusive and osmotic flows. We discuss limiting models when certain
Anisotropic damage modelling of biaxial behaviour and rupture of concrete structures
Boyer, Edmond
Anisotropic damage modelling of biaxial behaviour and rupture of concrete structures Ragueneau F with damage induced anisotropy modelling for concrete-like materials. A thermodynamics based constitutive relationship is presented coupling anisotropic damage and elasticity. The biaxial behaviour of such a model
Relation Between Structure, Function, and Imaging in a Three-Dimensional Model of the Lung
Lutchen, Kenneth
Relation Between Structure, Function, and Imaging in a Three-Dimensional Model of the Lung NORA T morphometric mod- els to predict function relations in the lung. These models, however, are not anatomically explicit. We have advanced a three-dimensional airway tree model to relate dynamic lung function
Structural Informatics, Modeling, and Design with an Open-Source Molecular Software Library (MSL)
Senes, Alessandro
Structural Informatics, Modeling, and Design with an Open-Source Molecular Software Library (MSL for the design, modeling, and analysis of macromolecules. Among the main features supported by the library coordinates (for modeling) and multiple amino acid identities at the same backbone position (for design
CU-CAS-02-08 CENTER FOR AEROSPACE STRUCTURES Volumetric Constraint Models
Felippa, Carlos A.
CU-CAS-02-08 CENTER FOR AEROSPACE STRUCTURES Volumetric Constraint Models for Anisotropic Elastic 429 BOULDER, COLORADO 80309 #12;Volumetric Constraint Models for Anisotropic Elastic Solids Carlos A. Conclusion 5 #12;Volumetric Constraint Models for Anisotropic Elastic Solids Carlos A. Felippa and Eugenio O
A polymer model with long-range interactions: analysis and applications to the chromatin structure
Holcman, David
A polymer model with long-range interactions: analysis and applications to the chromatin structure consists of the DNA and its hierarchy of interact- ing molecules that can be modeled as a complex polymer. To describe the chromatin dynamic, we develop and analyze here a polymer model that accounts for long range
Bachelor Thesis Modeling the interface of oxide hetero-structures
Pfeifer, Holger
composition at the SrTiO3-YBa2Cu2O7- La0.67Ca0.33MnO3 (Superconductor-Ferromagnet ) and LaSrAlO4-LaNiO3-LaAlO3 structures have been shown to have interesting properties including magnetism, superconductivity, metal
Proposed database model and file structures for arthropod collection management
Miller, Scott
the context of a single data management system. The value of this linkage is that it permits developers who. In some mainframe based database management systems, it is possible to define repeating subsets of information as part of a single database file structure. However, few personal computer-based systems have
Modeling Segregation and Grain Structure Development in Equiaxed
Beckermann, Christoph
grain and at the scale of a casting. The need for much additional researchis emphasized. INTRODUCTION The as-solidified structure of most statically and continuously cast metal alloys features both columnar, improved feed- ing to compensate for shrinkage and less hot cracking, improved surface proper- ties
Computational tools for modeling and measuring chromosome structure
Ross, Brian Christopher
2012-01-01
DNA conformation within cells has many important biological implications, but there are challenges both in modeling DNA due to the need for specialized techniques, and experimentally since tracing out in vivo conformations ...
This Text Has the Scent of Starbucks: A Laplacian Structured Sparsity Model for
Murphy, Robert F.
This Text Has the Scent of Starbucks: A Laplacian Structured Sparsity Model for Computational. To do this, we collected customer re- views from Starbucks, Dunkin' Donuts, and other coffee shops
Lee, Yuan-Hsuan
2011-10-21
This dissertation focuses on issues related to fitting an optimal variance-covariance structure in multilevel linear modeling framework with two Monte Carlo simulation studies. In the first study, the author evaluated the ...
Yang, Ming-Hsuan
Visual Tracking via Adaptive Structural Local Sparse Appearance Model Xu Jia Dalian University of Technology jiaxu1986@mail.dlut.edu.cn Huchuan Lu Dalian University of Technology lhchuan@dlut.edu.cn Ming
THE EMERGENT STRUCTURE OF THE DROSOPHILA WING A Dynamic Model Generator
Abate, Alessandro
THE EMERGENT STRUCTURE OF THE DROSOPHILA WING A Dynamic Model Generator Alberto Silletti Department packing; 2. then, given a movie (a sequence of frames) of the fly wing, correlate the networks generated
Stochastic 3D Modeling of the GDL Structure in PEMFCs Based on Thin Section Detection
Schmidt, Volker
Stochastic 3D Modeling of the GDL Structure in PEMFCs Based on Thin Section Detection Ralf layer GDL in proton exchange membrane fuel cells PEMFCs based on tools from stochastic geometry. The GDL
CEE 812 Structural Engineering Seminar Series Modeling seismic isolation systems for critical
Kamat, Vineet R.
hazards. At much smaller scales, seismic qualification criteria for telecommunications equipment involvesCEE 812 Structural Engineering Seminar Series Modeling seismic isolation systems for critical operations. The use of seismic isolation in the protection of these facilities is predicated upon
Haas, B J; Salzberg, S L; Zhu, W; Pertea, M; Allen, J E; Orvis, J; White, O; Buell, C R; Wortman, J R
2007-12-10
EVidenceModeler (EVM) is presented as an automated eukaryotic gene structure annotation tool that reports eukaryotic gene structures as a weighted consensus of all available evidence. EVM, when combined with the Program to Assemble Spliced Alignments (PASA), yields a comprehensive, configurable annotation system that predicts protein-coding genes and alternatively spliced isoforms. Our experiments on both rice and human genome sequences demonstrate that EVM produces automated gene structure annotation approaching the quality of manual curation.
DAMAGE DETECTION BASED ON STRUCTURAL RESPONSE TO TEMPERATURE CHANGES AND MODEL UPDATING
Boyer, Edmond
DAMAGE DETECTION BASED ON STRUCTURAL RESPONSE TO TEMPERATURE CHANGES AND MODEL UPDATING Marian The paper proposes use of measured structural response to temperature loads for purposes of damage identification. As opposed to the most common approaches, which rely on suppressing temperature effects in damage
Structure functions of the 2d O(n) non-linear sigma models
Janos Balog; Peter Weisz
2004-09-08
We investigate structure functions in the 2-dimensional (asymptotically free) non-linear O(n) sigma-models using the non-perturbative S-matrix bootstrap program. In particular the exact small (Bjorken) x behavior is derived. Structure functions in the special case of the n=3 model are accurately computed over the whole x range for $-q^2/M^2functions in the 1/n approximation are also presented.
First Structure Formation: II. Cosmic String + Hot Dark Matter Models
Tom Abel; Albert Stebbins; Peter Anninos; Michael L. Norman
1997-06-26
We examine the structure of baryonic wakes in the cosmological fluid which would form behind GUT-scale cosmic strings at early times (redshifts z > 100) in a neutrino-dominated universe. We show, using simple analytical arguments as well as 1- and 2-dimensional hydrodynamical simulations, that these wakes will NOT be able to form interesting cosmological objects before the neutrino component collapses. The width of the baryonic wakes (< 10 kpc comoving) is smaller than the scale of wiggles on the strings and are probably not enhanced by the wiggliness of the string network.
An Active and Structural Strain Model for Magnetostrictive Transducers \\Lambda
Flatau, Alison B.
by a magnetic bias generated by either the surrounding permanent magnet or an applied DC current to the solenoid consider the modeling of strains generated by magnetostrictive materials in response to applied magnetic magnetic fields and (ii) the application of magnetic fields generates large strains in the material
An Active and Structural Strain Model for Magnetostrictive Transducers
by a magnetic bias generated by either the surrounding permanent magnet or an applied DC current to the solenoid the modeling of strains generated by magnetostrictive materials in response to applied magnetic fields magnetic fields and (ii) the application of magnetic fields generates large strains in the material
An Active and Structural Strain Model for Magnetostrictive Transducers
Flatau, Alison B.
the modeling of strains generated by magnetostrictive materials in response to applied magnetic elds magnetic elds and ii the application of magnetic elds generates large strains in the material. By utilizing magnetostrictive rod, a wound wire solenoid, an enclosing permanent magnet and a prestress mechanism. The rod
A structured performance modelling formalism Stephen Gilmore1
Gilmore, Stephen
]). The combination of stochastic Petri nets with queueing networks in particular has been a source of inspiration's Dynamic Queueing Networks [12]. An extension of (non-stochastic) Petri nets which provides modelling language for labelled stochas- tic Petri nets. Viewed in another way, the net is used to provide
Pennycook, Steve
Structural model for the Al72Ni20Co8 decagonal quasicrystals Yanfa Yan National Renewable Energy, Oak Ridge, Tennessee 37831 Received 15 February 2000 We propose a structure model for the Al72Ni20Co8 structural models have been proposed for de- cagonal quasicrystals based upon x-ray and neutron diffrac- tion
Modelling the Structure and Dynamics of Science Using Books
Ginda, Michael; Borner, Katy
2015-01-01
Scientific research is a major driving force in a knowledge based economy. Income, health and wellbeing depend on scientific progress. The better we understand the inner workings of the scientific enterprise, the better we can prompt, manage, steer, and utilize scientific progress. Diverse indicators and approaches exist to evaluate and monitor research activities, from calculating the reputation of a researcher, institution, or country to analyzing and visualizing global brain circulation. However, there are very few predictive models of science that are used by key decision makers in academia, industry, or government interested to improve the quality and impact of scholarly efforts. We present a novel 'bibliographic bibliometric' analysis which we apply to a large collection of books relevant for the modelling of science. We explain the data collection together with the results of the data analyses and visualizations. In the final section we discuss how the analysis of books that describe different modellin...
Modeling direct interband tunneling. II. Lower-dimensional structures
Pan, Andrew; Chui, Chi On
2014-08-07
We investigate the applicability of the two-band Hamiltonian and the widely used Kane analytical formula to interband tunneling along unconfined directions in nanostructures. Through comparisons with k·p and tight-binding calculations and quantum transport simulations, we find that the primary correction is the change in effective band gap. For both constant fields and realistic tunnel field-effect transistors, dimensionally consistent band gap scaling of the Kane formula allows analytical and numerical device simulations to approximate non-equilibrium Green's function current characteristics without arbitrary fitting. This allows efficient first-order calibration of semiclassical models for interband tunneling in nanodevices.
Discovering Block-Structured Process Models From Event Logs -A Constructive Approach
van der Aalst, Wil
Discovering Block-Structured Process Models From Event Logs - A Constructive Approach S University of Technology, P.O. Box 513, NL-5600 MB, Eindhoven, The Netherlands Abstract Process discovery is the problem of, given a log of observed behaviour, finding a process model that `best' describes
Senescence and antibiotic resistance in an age-structured population model
Gedeon, Tomas
and other interventions that focus on reducing the transmission of antimicrobial-resistant bacteria betweenSenescence and antibiotic resistance in an age-structured population model Patrick De Leenheer Jack the growing problem of antibiotic resistance of microbial populations. Here we investigate a model
Behavior-Based Methods for Modeling and Structuring Control of Social Robots
Mataric, Maja J.
-to-end validation of social theories that deal with self-referential notions and require validation. A centralBehavior-Based Methods for Modeling and Structuring Control of Social Robots Dylan A. Shell social biological systems. A working robotic imple- mentation based on a biologically plausible model
FILAMENT CHANNEL STRUCTURES IN A Si IV LINE RELATED TO A 3D MAGNETIC MODEL
Aulanier, Guillaume
FILAMENT CHANNEL STRUCTURES IN A Si IV LINE RELATED TO A 3D MAGNETIC MODEL T. A. KUCERA1,, G. A recent 3D magnetic model of filament support (Aulanier and DÃ©moulin, 1998) has shown that specific of a filament observed in H and Ca II lines with the German telescope VTT in Tenerife on 25 September 1996
Filament-Level Modeling of Aramid-Based High-Performance Structural Materials
Grujicic, Mica
Filament-Level Modeling of Aramid-Based High-Performance Structural Materials M. Grujicic, W/ filaments. These fibers can be considered as prototypes for advanced high strength/high-stiffness fibers to be most affected by the presence of sheet stacking faults. Keywords filament-level modeling, Kevlar
Yandell, Brian S.
be computationally feasible on a na- tional basis. For this study, a structural log-linear model for sire models for genetic evaluation of dairy cattle assume that genetic and residual components of variance and conformation traits, which can reduce accuracy of selection and cause biases in the proportions of breeding
A SURVEY OF COMMODITY MARKETS AND STRUCTURAL MODELS FOR ELECTRICITY PRICES
Carmona, Rene
A SURVEY OF COMMODITY MARKETS AND STRUCTURAL MODELS FOR ELECTRICITY PRICES RENE CARMONA AND MICHAEL and the methods which have been proposed to handle them in spot and forward price models. We devote special focus on the important role of other energy prices and fundamental factors in setting the power price
Characterization of Interfacial Structure in PEFCs: Water Storage and Contact Resistance Model
Mench, Matthew M.
Characterization of Interfacial Structure in PEFCs: Water Storage and Contact Resistance Model PEFC . The model utilizes experimentally measured surface profile data as input. Results indicate that the uncompressed surface morphology of mating materials, the elasticity of PEFC components, and the local
Shirai, Kiyoaki
: The language model used in a statistical parser should have probabilistically well-founded se- mantics, which simultaneously1 . In this context, we newly designed a framework of statistical language modeling taking all) and (Collins, 1997) due to the lack of modularity of statistical types. 2Although syntactic structure R
An Efficient Genetic Algorithm for Predicting Protein Tertiary Structures in the 2D HP Model
Istrail, Sorin
, predicting its tertiary structure is known as the protein folding problem. This problem has been widely genetic algo- rithm for the protein folding problem under the HP model in the two-dimensional square Genetic Algorithm, Protein Folding Problem, 2D HP Model 1. INTRODUCTION Amino acids are the building
Complete Structural Model of Escherichia coli RNA Polymerase from a Hybrid Approach
Opalka, N.; Brown, J; Lane, W; Twist, K; Landick, R; Asturias, F; Darst, S
2010-01-01
The Escherichia coli transcription system is the best characterized from a biochemical and genetic point of view and has served as a model system. Nevertheless, a molecular understanding of the details of E. coli transcription and its regulation, and therefore its full exploitation as a model system, has been hampered by the absence of high-resolution structural information on E. coli RNA polymerase (RNAP). We use a combination of approaches, including high-resolution X-ray crystallography, ab initio structural prediction, homology modeling, and single-particle cryo-electron microscopy, to generate complete atomic models of E. coli core RNAP and an E. coli RNAP ternary elongation complex. The detailed and comprehensive structural descriptions can be used to help interpret previous biochemical and genetic data in a new light and provide a structural framework for designing experiments to understand the function of the E. coli lineage-specific insertions and their role in the E. coli transcription program. Transcription, or the synthesis of RNA from DNA, is one of the most important processes in the cell. The central enzyme of transcription is the DNA-dependent RNA polymerase (RNAP), a large, macromolecular assembly consisting of at least five subunits. Historically, much of our fundamental information on the process of transcription has come from genetic and biochemical studies of RNAP from the model bacterium Escherichia coli. More recently, major breakthroughs in our understanding of the mechanism of action of RNAP have come from high resolution crystal structures of various bacterial, archaebacterial, and eukaryotic enzymes. However, all of our high-resolution bacterial RNAP structures are of enzymes from the thermophiles Thermus aquaticus or T. thermophilus, organisms with poorly characterized transcription systems. It has thus far proven impossible to obtain a high-resolution structure of E. coli RNAP, which has made it difficult to relate the large collection of genetic and biochemical data on RNAP function directly to the available structural information. Here, we used a combination of approaches - high-resolution X-ray crystallography of E. coli RNAP fragments, ab initio structure prediction, homology modeling, and single-particle cryo-electron microscopy - to generate complete atomic models of E. coli RNAP. Our detailed and comprehensive structural models provide the heretofore missing structural framework for understanding the function of the highly characterized E. coli RNAP.
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545 (United States); Grosse-Kunstleve, Ralf W.; Afonine, Pavel V.; Moriarty, Nigel W.; Zwart, Peter H. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720 (United States); Hung, Li-Wei [Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545 (United States); Read, Randy J. [Department of Haematology, University of Cambridge, Cambridge CB2 0XY (United Kingdom); Adams, Paul D., E-mail: terwilliger@lanl.gov [Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720 (United States); Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545 (United States)
2008-01-01
The highly automated PHENIX AutoBuild wizard is described. The procedure can be applied equally well to phases derived from isomorphous/anomalous and molecular-replacement methods. The PHENIX AutoBuild wizard is a highly automated tool for iterative model building, structure refinement and density modification using RESOLVE model building, RESOLVE statistical density modification and phenix.refine structure refinement. Recent advances in the AutoBuild wizard and phenix.refine include automated detection and application of NCS from models as they are built, extensive model-completion algorithms and automated solvent-molecule picking. Model-completion algorithms in the AutoBuild wizard include loop building, crossovers between chains in different models of a structure and side-chain optimization. The AutoBuild wizard has been applied to a set of 48 structures at resolutions ranging from 1.1 to 3.2 Å, resulting in a mean R factor of 0.24 and a mean free R factor of 0.29. The R factor of the final model is dependent on the quality of the starting electron density and is relatively independent of resolution.
Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545, USA; Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720, USA; Department of Haematology, University of Cambridge, Cambridge CB2 0XY, England; Terwilliger, Thomas; Terwilliger, T.C.; Grosse-Kunstleve, Ralf Wilhelm; Afonine, P.V.; Moriarty, N.W.; Zwart, P.H.; Hung, L.-W.; Read, R.J.; Adams, P.D.
2007-04-29
The PHENIX AutoBuild Wizard is a highly automated tool for iterative model-building, structure refinement and density modification using RESOLVE or TEXTAL model-building, RESOLVE statistical density modification, and phenix.refine structure refinement. Recent advances in the AutoBuild Wizard and phenix.refine include automated detection and application of NCS from models as they are built, extensive model completion algorithms, and automated solvent molecule picking. Model completion algorithms in the AutoBuild Wizard include loop-building, crossovers between chains in different models of a structure, and side-chain optimization. The AutoBuild Wizard has been applied to a set of 48 structures at resolutions ranging from 1.1 {angstrom} to 3.2 {angstrom}, resulting in a mean R-factor of 0.24 and a mean free R factor of 0.29. The R-factor of the final model is dependent on the quality of the starting electron density, and relatively independent of resolution.
Folding Proteins with Both Alpha and Beta Structures in a Reduced Model
Nan-yow Chen
2006-07-17
A reduced model, which can fold both helix and sheet structures, is proposed to study the problem of protein folding. The goal of this model is to find an unbiased effective potential that has included the effects of water and at the same time can predict the three dimensional structure of a protein with a given sequence in reasonable time. For this purpose, rather than focusing on the real folding dynamics or full structural details at the atomic scale, we adopt the Monte Carlo method and the coarse-grained representation of the protein in which both side-chains and the backbones are replaced by suitable geometrical objects in consistent with the known structure. On top of the coarse-grained representation, our effective potential can be developed. Two new interactions, the dipole-dipole interactions and the local hydrophobic interactions, are introduced and are shown to be as crucial as the hydrogen bonds for forming the secondary structures. In particular, for the first time, we demonstrate that the resulting reduced model can successfully fold proteins with both helix and sheet structures without using any biased potential. Further analyses show that this model can also fold other proteins in reasonable accuracy and thus provides a promising starting point for the problem of protein folding.
Stellar and Gaseous Disk Structures in Cosmological Galaxy Equilibrium Models
Rathaus, Ben
2015-01-01
We present "radially-resolved-equilibrium-models" for the growth of stellar and gaseous disks in cosmologically accreting massive halos. Our focus is on objects that evolve to redshifts $z\\sim 2$. We solve the time-dependent equations that govern the radially dependent star-formation rates, inflows and outflows from and to the inter- and circum-galactic medium, and inward radial gas flows within the disks. The stellar and gaseous disks reach equilibrium configurations on dynamical time scales much shorter than variations in the cosmological dark matter halo growth and baryonic accretions rates. We show analytically that mass and global angular momentum conservation naturally give rise to exponential gas and stellar disks over many radial length scales. The gaseous disks are more extended as set by the condition Toomre $Q<1$ for star-formation. The disks rapidly become baryon dominated. For massive, $5\\times 10^{12}M_\\odot$ halos at redshift $z=2$, we reproduced the typical observed star-formation rates of ...
Grujicic, Mica
of reactive melt infiltration process used in fabrication of ceramic-matrix composites (CMCs) Mica Grujicic in fabrication of ceramic-matrix composites (CMCs)", Multidiscipline Modeling in Materials and Structures, Vol used in fabrication of ceramic-matrix composites (CMCs) Mica Grujicic, Rohan Galgalikar, S. Ramaswami
Vibration-based health monitoring and model refinement of civil engineering structures
Farrar, C.R.; Doebling, S.W.
1997-10-01
Damage or fault detection, as determined by changes in the dynamic properties of structures, is a subject that has received considerable attention in the technical literature beginning approximately 30 years ago. The basic idea is that changes in the structure`s properties, primarily stiffness, will alter the dynamic properties of the structure such as resonant frequencies and mode shapes, and properties derived from these quantities such as modal-based flexibility. Recently, this technology has been investigated for applications to health monitoring of large civil engineering structures. This presentation will discuss such a study undertaken by engineers from New Mexico Sate University, Sandia National Laboratory and Los Alamos National Laboratory. Experimental modal analyses were performed in an undamaged interstate highway bridge and immediately after four successively more severe damage cases were inflicted in the main girder of the structure. Results of these tests provide insight into the abilities of modal-based damage ID methods to identify damage and the current limitations of this technology. Closely related topics that will be discussed are the use of modal properties to validate computer models of the structure, the use of these computer models in the damage detection process, and the general lack of experimental investigation of large civil engineering structures.
Simons, Mark
Some thoughts on the use of InSAR data to constrain models of surface deformation: Noise structure models of surface deformation: Noise structure and data downsampling, Geochem. Geophys. Geosyst., 6, Q of data points. Here we estimate the actual covariance structure of noise in InSAR data. We compare
Computational modeling of structure of metal matrix composite in centrifugal casting process
Zagorski, Roman [Department of Electrotechnology, Faculty of Materials Science and Metallurgy, Silesian University of Technology, ul. Krasinskiego 8, 40-019, Katowice (Poland)
2007-04-07
The structure of alumina matrix composite reinforced with crystalline particles obtained during centrifugal casting process are studied. Several parameters of cast process like pouring temperature, temperature, rotating speed and size of casting mould which influent on structure of composite are examined. Segregation of crystalline particles depended on other factors such as: the gradient of density of the liquid matrix and reinforcement, thermal processes connected with solidifying of the cast, processes leading to changes in physical and structural properties of liquid composite are also investigated. All simulation are carried out by CFD program Fluent. Numerical simulations are performed using the FLUENT two-phase free surface (air and matrix) unsteady flow model (volume of fluid model - VOF) and discrete phase model (DPM)
Model Close Match as a Criterion for Structured Model Comparison and Its Robust Statistical Tests
Li, Libo; Bentler, Peter M
2006-01-01
Model Selection. Manuscript. Curran, P. J. , Bollen, K. A. ,316. Bollen, K. A. , & Curran, P. J. (2006). Latent Curveare given by Bollen and Curran (2006), Byrne (2006), Hays,
The structure of the free energy surface of coarse-grained off-lattice protein models
E. Akturk; H. Arkin Olgar; T. Celik
2007-03-23
We have performed multicanonical simulations of hydrophobic-hydrophilic heteropolymers with a simple effective, coarse-grained off-lattice model to study the structure and the topology of the energy surface. The multicanonical method samples the whole rugged energy landscape, in particular the low-energy part, and enables one to better understand the critical behaviors and visualize the folding pathways of the considered protein model.
Spongins: nanostructural investigations and development of biomimetic material model
Maldonado, Manuel
, papain, elastase, lysozyme, cellulase and amylase /5/. Weak acid or alkaline hydrolysis were no more
Dynamic model failure tests of dam structures Dalian University of Technology, Dalian 116024, China
Spencer Jr., Billie F.
index for the safety assessment of concrete dams and is predicted through dynamic model failure tests INTRODUCTION A great number of high dams will be built in highly seismic areas, the safety evaluation 116024, China ABSTRACT: For the earthquake safety evaluation of dam structures, it is desirable to extend
Paris-Sud XI, Université de
Modelling Bulk Density According to Structure Development: Toward an Indicator of Microstructure the microaggregates with a small contribution of large pores resulting from root development and macrofaunal activity.25 g cm-3 among the 108 samples studied. Visual assessment of BESI showed that soil material
Optimization of the structural Gabor functions in a homogeneous velocity model
Cerveny, Vlastislav
Optimization of the structural Gabor functions in a homogeneous velocity model for a zero-o#11;set functions should be optimized, and the Gabor functions should form a frame. We present a simple attempt functions and the space{wavenumber lattice of their central points are optimized analytically
On 3D modeling of seismic wave propagation via a structured ...
2011-07-27
In many problems following the discretization of linear par- tial differential ... ods to mitigate its nonlinear nature. The Helmholtz- .... based on certain sparse matrix techniques and structured ma- ..... tain power of 2. .... Upper left: partial SEAM velocity model; upper right: 7.5Hz time-harmonic wavefield with quality factor Q =.
Chang, Grace C.
that contributed to the evolution of observed thermal structure and resuspension of particulate matter during resuspension processes. It is concluded that wave-current bottom shear stress was clearly the most important process for sediment resuspension during and following both hurricanes. Discrepancies between modeled
Guidoni, Leonardo
Hybrid Car-Parrinello/Molecular Mechanics Modelling of Transition Metal Complexes: Structure). We have recently developed a QM/MM extension of a Car-Parrinello scheme [5]. These hybrid Car functional theory embedded in a classical force field description. The power of such a combined Car
Structuring Measurements for Modeling and the Deployment of Industrial Wireless Networks
Zilic, Zeljko
. Replacing wired units with wireless sensor network (WSN) nodes offers more flexibility, and ultimately coverage during its deployment. Wireless networking devices are inherently power-limited, which limits1 Structuring Measurements for Modeling and the Deployment of Industrial Wireless Networks Rong
Boyer, Edmond
STRUCTURAL DAMAGE CLASSIFICATION COMPARISON USING SUPPORT VECTOR MACHINE AND BAYESIAN MODEL, CA, USA 92093-0085 mdtodd@ucsd.edu ABSTRACT Since all damage identification strategies inevitably in the decision-making process of damage detection, classification, and prognosis, which employs training data (or
Multi-scale modelling of III-nitrides: from dislocations to the electronic structure
Holec, David
level modelling for the case of the critical thickness of thin epitaxial layers, and covers some issues of simulating the electronic structure of III-nitride alloys by means of the first principle methods. The first part of this work discusses several...
Predicting Protein Folds with Structural Repeats Using a Chain Graph Model
Carbonell, Jaime
Predicting Protein Folds with Structural Repeats Using a Chain Graph Model Yan Liu yanliu, Carnegie Mellon University, Pittsburgh, PA 15213 USA Abstract Protein fold recognition is a key step to to accurately identify protein folds aris- ing from typical spatial arrangements of well-defined secondary
Folding Trp-Cage to NMR Resolution Native Structure Using a Coarse-Grained Protein Model
Buldyrev, Sergey
Folding Trp-Cage to NMR Resolution Native Structure Using a Coarse-Grained Protein Model Feng Ding molecular dynamics folding simulations of a small 20-residue protein--Trp-cage--from a fully extended is not necessary to reach the native state of a protein. Our results also suggest that the success of folding Trp
Finite element modeling of long-term fluid-structure interaction problems in geological media
Anderson, C.A.
1980-01-01
A model is developed to predict long-term thermal creep and creep rupture in geological structures under multiaxial stress states and under elevated temperature conditions. An example of the method is given showing the behavior of the crust and mantle while undergoing intrusion by a low density diaper. (ACR)
Pictures: A simple structured graphics model Sigbjorn Finne and Simon Peyton Jones,
Jones, Simon Peyton
Pictures: A simple structured graphics model Sigbjorn Finne and Simon Peyton Jones, Department, or pictures, are represented as values that functions can manipuÂ late and inspect to create new values. Complete pictures are constructed by repeatedly composing such picture values together using picture com
VERTICALLY INHOMOGENEOUS MODELS OF THE UPPER CRUSTAL STRUCTURE IN THE WEST-BOHEMIAN SEISMOACTIVE
Cerveny, Vlastislav
VERTICALLY INHOMOGENEOUS MODELS OF THE UPPER CRUSTAL STRUCTURE IN THE WEST-BOHEMIAN SEISMOACTIVE in the year 2000, three profiles traversed the region of earthquake swarms in West- Bohemia/Vogtland. The shots were also recorded at the permanent stations of the local seismic networks. The travel times of P
Structuring Risk in E-Government Development Projects Using a Causal Model Abdullah Al-Shehab
Winstanley, Graham
Structuring Risk in E-Government Development Projects Using a Causal Model Abdullah Al-Shehab 1 projects is minimal compared with traditional Information System (IS) development projects. The success projects, and this research uses a similar approach applied in E-Gov development projects. This experiment
Paxton, Anthony T.
Relative energetics and structural properties of zirconia using a self-consistent tight We describe an empirical, self-consistent, orthogonal tight-binding model for zirconia, which allows orders the zero temperature energies of all zirconia polymorphs. The Zr-O matrix elements
Vajda, Sandor
Discrimination of Near-Native Protein Structures From Misfolded Models by Empirical Free Energy University, Boston, Massachusetts ABSTRACT Free energy potentials, combining molecular mechanics of discrimination that in- clude the correlation coefficient between RMSD and free energy, and a new measure labeled
A conceptual model for the origin of fault damage zone structures in high-porosity sandstone
Cowie, Patience
A conceptual model for the origin of fault damage zone structures in high-porosity sandstone Zoe K-porosity sandstones. Damage zone deformation has been particularly well constrained for two 4-km-long normal faults formed in the Navajo Sandstone of central Utah, USA. For these faults the width of the damage zone
On the Phase Structure of the Schwinger Model with Wilson Fermions
H. Gausterer; C. B. Lang
1993-11-19
We study the phase structure of the massive one flavour lattice Schwinger model on the basis of the finite size scaling behaviour of the partition function zeroes. At $\\beta = 0$ we observe and discuss a possible discrepancy with results obtained by a different method.
Structural parameters The analytical model proposed here can explain high fracture
Barthelat, Francois
Structural parameters · The analytical model proposed here can explain high fracture toughness, P.J., et al., Engineering Fracture Mechanics, 2007. 74: p. 19281941. 4. Ritchie, R.O., et al Tensile strength Fracture toughness Composite properties E max S )~( ~ aJ III. Fracture toughness
Microscopic model for intersubband gain from electrically pumped quantum-dot structures
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Michael, Stephan; Chow, Weng Wah; Schneider, Han Christian
2014-10-03
We study theoretically the performance of electrically pumped self-organized quantum dots as a gain material in the mid-IR range at room temperature. We analyze an AlGaAs/InGaAs based structure composed of dots-in-a-well sandwiched between two quantum wells. We numerically analyze a comprehensive model by combining a many-particle approach for electronic dynamics with a realistic modeling of the electronic states in the whole structure. We investigate the gain both for quasi-equilibrium conditions and current injection. Comparing different structures, we find that steady-state gain can only be realized by an efficient extraction process, which prevents an accumulation of electrons in continuum states, thatmore »make the available scattering pathways through the quantum dot active region too fast to sustain inversion.« less
Yunovich, M.; Thompson, N.G.
1998-12-31
During the past fifteen years corrosion inhibiting admixtures (CIAs) have become increasingly popular for protection of reinforced components of highway bridges and other structures from damage induced by chlorides. However, there remains considerable debate about the benefits of CIAs in concrete. A variety of testing methods to assess the performance of CIA have been reported in the literature, ranging from tests in simulated pore solutions to long-term exposures of concrete slabs. The paper reviews the published techniques and recommends the methods which would make up a comprehensive CIA effectiveness testing program. The results of this set of tests would provide the data which can be used to rank the presently commercially available CIA and future candidate formulations utilizing a proposed predictive model. The model is based on relatively short-term laboratory testing and considers several phases of a service life of a structure (corrosion initiation, corrosion propagation without damage, and damage to the structure).
Rao, Rekha R.; Celina, Mathias C.; Giron, Nicholas Henry; Long, Kevin Nicholas; Russick, Edward M.
2015-01-01
We are developing computational models to help understand manufacturing processes, final properties and aging of structural foam, polyurethane PMDI. Th e resulting model predictions of density and cure gradients from the manufacturing process will be used as input to foam heat transfer and mechanical models. BKC 44306 PMDI-10 and BKC 44307 PMDI-18 are the most prevalent foams used in structural parts. Experiments needed to parameterize models of the reaction kinetics and the equations of motion during the foam blowing stages were described for BKC 44306 PMDI-10 in the first of this report series (Mondy et al. 2014). BKC 44307 PMDI-18 is a new foam that will be used to make relatively dense structural supports via over packing. It uses a different catalyst than those in the BKC 44306 family of foams; hence, we expect that the reaction kineti cs models must be modified. Here we detail the experiments needed to characteriz e the reaction kinetics of BKC 44307 PMDI-18 and suggest parameters for the model based on these experiments. In additi on, the second part of this report describes data taken to provide input to the preliminary nonlinear visco elastic structural response model developed for BKC 44306 PMDI-10 foam. We show that the standard cu re schedule used by KCP does not fully cure the material, and, upon temperature elevation above 150 o C, oxidation or decomposition reactions occur that alter the composition of the foam. These findings suggest that achieving a fully cured foam part with this formulation may be not be possible through therma l curing. As such, visco elastic characterization procedures developed for curing thermosets can provide only approximate material properties, since the state of the material continuously evolves during tests.
Bifurcation structures and transient chaos in a four-dimensional Chua model
Anderson Hoff; Denilson T. da Silva; Cesar Manchein; Holokx A. Albuquerque
2013-12-06
A four-dimensional four-parameter Chua model with cubic nonlinearity is studied applying numerical continuation and numerical solutions methods. Regarding numerical solution methods, its dynamics is characterized on Lyapunov and isoperiodic diagrams and regarding numerical continuation method, the bifurcation curves are obtained. Combining both methods the bifurcation structures of the model were obtained with the possibility to describe the {\\it shrimp}-shaped domains and their endoskeletons. We study the effect of a parameter that controls the dimension of the system leading the model to present transient chaos with its corresponding basin of attraction being riddled.
Scanning tunneling microscopy studies on the structure and stability of model catalysts
Yang, Fan
2009-05-15
, especially under CO oxidation conditions, and 2) synthesizing and characterizing a series of alloy model catalysts for future model catalytic studies. In our study, Au clusters supported on TiO 2 (110) have been used to model supported Au catalysts. Our... STM studies in UHV reveal surface structures of TiO 2 (110) and show undercoordinated Ti cations play a critical role in the nucleation and stabilization of Au clusters on TiO 2 (110). Exposing the TiO 2 (110) surface to water vapor causes...
Macroscale modeling and mesoscale observations of plasma density structures in the polar cap
Basu, S. [Phillips Lab., Hanscom Air Force Base, MA (United States)] [Phillips Lab., Hanscom Air Force Base, MA (United States); Basu, S. [National Science Foundation, Arlington, VA (United States)] [National Science Foundation, Arlington, VA (United States); Sojka, J.J. [Utah State Univ., Logan, UT (United States)] [and others] [Utah State Univ., Logan, UT (United States); and others
1995-04-15
The seasonal and UT variation of mesoscale structures (10 km - 100 m) in the central polar cap has been obtained from an analysis of 250-MHz intensity scintillation observations made at Thule, Greenland. It has been established earlier that mesoscale structures causing scintillations of satellite signals may develop at the edges of macroscale structures (several hundred km) such as discrete polar cap plasma density enhancements or patches through the gradient drift instability process. As such, the authors examined the seasonal and UT variation of polar cap patches simulated by using the USU Time Dependent Ionospheric Model (TDIM) under conditions of southward B{sub z}. A fairly remarkable similarity is found between the scintillation observations and the model predictions of patch occurrence. For instance, both the patch and scintillation occurrences are minimized during the winter solstice (northern hemisphere) between 0800-1200 UT while also having their largest seasonal intensity between 2000-2400 UT. Little UT dependence of patches and scintillations is seen at equinox with high intensity being observed throughout the day, while during local summer the intensity of macroscale patches and mesoscale irregularities are found to be a minimum at all UT. These results indicate that macroscale features in the polar cap are routinely associated with plasma instabilities giving rise to smaller scale structures and that the specific patch formation mechanism assumed in the simulation is consistent with the observations. This ability to bridge between macroscale modeling and mesoscale observations provides a natural framework for the modeling of mesoscale structures themselves. This mesoscale modeling, in turn, can be utilized in a variety of radar and communication systems applications in the polar region. 25 refs., 3 figs.
Introducing improved structural properties and salt dependence into a coarse-grained model of DNA
Snodin, Benedict E. K. Mosayebi, Majid; Schreck, John S.; Romano, Flavio; Doye, Jonathan P. K.; Randisi, Ferdinando; Šulc, Petr; Ouldridge, Thomas E.; Tsukanov, Roman; Nir, Eyal; Louis, Ard A.
2015-06-21
We introduce an extended version of oxDNA, a coarse-grained model of deoxyribonucleic acid (DNA) designed to capture the thermodynamic, structural, and mechanical properties of single- and double-stranded DNA. By including explicit major and minor grooves and by slightly modifying the coaxial stacking and backbone-backbone interactions, we improve the ability of the model to treat large (kilobase-pair) structures, such as DNA origami, which are sensitive to these geometric features. Further, we extend the model, which was previously parameterised to just one salt concentration ([Na{sup +}] = 0.5M), so that it can be used for a range of salt concentrations including those corresponding to physiological conditions. Finally, we use new experimental data to parameterise the oxDNA potential so that consecutive adenine bases stack with a different strength to consecutive thymine bases, a feature which allows a more accurate treatment of systems where the flexibility of single-stranded regions is important. We illustrate the new possibilities opened up by the updated model, oxDNA2, by presenting results from simulations of the structure of large DNA objects and by using the model to investigate some salt-dependent properties of DNA.
Introducing Improved Structural Properties and Salt Dependence into a Coarse-Grained Model of DNA
Benedict E. K. Snodin; Ferdinando Randisi; Majid Mosayebi; Petr Sulc; John S. Schreck; Flavio Romano; Thomas E. Ouldridge; Roman Tsukanov; Eyal Nir; Ard A. Louis; Jonathan P. K. Doye
2015-05-19
We introduce an extended version of oxDNA, a coarse-grained model of DNA designed to capture the thermodynamic, structural and mechanical properties of single- and double-stranded DNA. By including explicit major and minor grooves, and by slightly modifying the coaxial stacking and backbone-backbone interactions, we improve the ability of the model to treat large (kilobase-pair) structures such as DNA origami which are sensitive to these geometric features. Further, we extend the model, which was previously parameterised to just one salt concentration ([Na$^+$]=0.5M), so that it can be used for a range of salt concentrations including those corresponding to physiological conditions. Finally, we use new experimental data to parameterise the oxDNA potential so that consecutive adenine bases stack with a different strength to consecutive thymine bases, a feature which allows a more accurate treatment of systems where the flexibility of single-stranded regions is important. We illustrate the new possibilities opened up by the updated model, oxDNA2, by presenting results from simulations of the structure of large DNA objects and by using the model to investigate some salt-dependent properties of DNA.
Surface structural ion adsorption modeling of competitive binding of oxyanions by metal (hydr)oxides
Hiemstra, T.; Riemsdijk, W.H. van
1999-02-01
An important challenge in surface complexation models (SCM) is to connect the molecular microscopic reality to macroscopic adsorption phenomena. This study elucidates the primary factor controlling the adsorption process by analyzing the adsorption and competition of PO{sub 4}, AsO{sub 4}, and SeO{sub 3}. The authors show that the structure of the surface-complex acting in the dominant electrostatic field can be ascertained as the primary controlling adsorption factor. The surface species of arsenate are identical with those of phosphate and the adsorption behavior is very similar. On the basis of the selenite adsorption, The authors show that the commonly used 1pK models are incapable to incorporate in the adsorption modeling the correct bidentate binding mechanism found by spectroscopy. The use of the bidentate mechanism leads to a proton-oxyanion ratio and corresponding pH dependence that are too large. The inappropriate intrinsic charge attribution to the primary surface groups and the condensation of the inner sphere surface complex to a point charge are responsible for this behavior of commonly used 2pK models. Both key factors are differently defined in the charge distributed multi-site complexation (CD-MUSIC) model and are based in this model on a surface structural approach. The CD-MUSIC model can successfully describe the macroscopic adsorption phenomena using the surface speciation and binding mechanisms as found by spectroscopy. The model is also able to predict the anion competition well. The charge distribution in the interface is in agreement with the observed structure of surface complexes.
Tice, Julie Anne Goodwin
1996-01-01
This research used structural equation modeling to test the construct validity of measures I I ion, and work of four global constructs: trait socialization, self-concept, organizational socialization' concept. Using measurement model procedures...
Nguyen, Ba Nghiep; Jin, Xiaoshi; Wang, Jin; Phelps, Jay; Tucker III, Charles L.; Kunc, Vlastimil; Bapanapalli, Satish K.; Smith, Mark T.
2010-02-23
This report describes the work conducted under the Cooperative Research and Development Agreement (CRADA) (Nr. 260) between the Pacific Northwest National Laboratory (PNNL) and Autodesk, Inc. to develop and implement process models for injection-molded long-fiber thermoplastics (LFTs) in processing software packages. The structure of this report is organized as follows. After the Introduction Section (Section 1), Section 2 summarizes the current fiber orientation models developed for injection-molded short-fiber thermoplastics (SFTs). Section 3 provides an assessment of these models to determine their capabilities and limitations, and the developments needed for injection-molded LFTs. Section 4 then focuses on the development of a new fiber orientation model for LFTs. This model is termed the anisotropic rotary diffusion - reduced strain closure (ARD-RSC) model as it explores the concept of anisotropic rotary diffusion to capture the fiber-fiber interaction in long-fiber suspensions and uses the reduced strain closure method of Wang et al. to slow down the orientation kinetics in concentrated suspensions. In contrast to fiber orientation modeling, before this project, no standard model was developed to predict the fiber length distribution in molded fiber composites. Section 5 is therefore devoted to the development of a fiber length attrition model in the mold. Sections 6 and 7 address the implementations of the models in AMI, and the conclusions drawn from this work is presented in Section 8.
The large-scale structure of semantic networks: statistical analyses and a model for semantic growth
Mark Steyvers; Joshua B. Tenenbaum
2001-10-01
We present statistical analyses of the large-scale structure of three types of semantic networks: word associations, WordNet, and Roget's thesaurus. We show that they have a small-world structure, characterized by sparse connectivity, short average path-lengths between words, and strong local clustering. In addition, the distributions of the number of connections follow power laws that indicate a scale-free pattern of connectivity, with most nodes having relatively few connections joined together through a small number of hubs with many connections. These regularities have also been found in certain other complex natural networks, such as the world wide web, but they are not consistent with many conventional models of semantic organization, based on inheritance hierarchies, arbitrarily structured networks, or high-dimensional vector spaces. We propose that these structures reflect the mechanisms by which semantic networks grow. We describe a simple model for semantic growth, in which each new word or concept is connected to an existing network by differentiating the connectivity pattern of an existing node. This model generates appropriate small-world statistics and power-law connectivity distributions, and also suggests one possible mechanistic basis for the effects of learning history variables (age-of-acquisition, usage frequency) on behavioral performance in semantic processing tasks.
Joshua D. Younger; Zoltan Haiman; Greg L. Bryan; Sheng Wang
2006-12-22
Forthcoming large galaxy cluster surveys will yield tight constraints on cosmological models. It has been shown that in an idealized survey, containing > 10,000 clusters, statistical errors on dark energy and other cosmological parameters will be at the percent level. It has also been shown that through "self-calibration", parameters describing the mass-observable relation and cosmology can be simultaneously determined, though at a loss in accuracy by about an order of magnitude. Here we examine the utility of an alternative approach of self-calibration, in which a parametrized ab-initio physical model is used to compute cluster structure and the resulting mass-observable relations. As an example, we use a modified-entropy ("pre-heating") model of the intracluster medium, with the history and magnitude of entropy injection as unknown input parameters. Using a Fisher matrix approach, we evaluate the expected simultaneous statistical errors on cosmological and cluster model parameters. We study two types of surveys, in which a comparable number of clusters are identified either through their X-ray emission or through their integrated Sunyaev-Zel'dovich (SZ) effect. We find that compared to a phenomenological parametrization of the mass-observable relation, using our physical model yields significantly tighter constraints in both surveys, and offers substantially improved synergy when the two surveys are combined. These results suggest that parametrized physical models of cluster structure will be useful when extracting cosmological constraints from SZ and X-ray cluster surveys. (abridged)
Random vibration sensitivity studies of modeling uncertainties in the NIF structures
Swensen, E.A.; Farrar, C.R. [Los Alamos National Lab., NM (United States); Barron, A.A. [Stanford Univ., CA (United States). Dept. of Civil Engineering; Cornwell, P. [Rose-Hulman Inst. of Tech., Terre Haute, IN (United States). Mechanical Engineering Dept.
1996-12-31
The National Ignition Facility is a laser fusion project that will provide an above-ground experimental capability for nuclear weapons effects simulation. This facility will achieve fusion ignition utilizing solid-state lasers as the energy driver. The facility will cover an estimated 33,400 m{sup 2} at an average height of 5--6 stories. Within this complex, a number of beam transport structures will be houses that will deliver the laser beams to the target area within a 50 {micro}m ms radius of the target center. The beam transport structures are approximately 23 m long and reach approximately heights of 2--3 stories. Low-level ambient random vibrations are one of the primary concerns currently controlling the design of these structures. Low level ambient vibrations, 10{sup {minus}10} g{sup 2}/Hz over a frequency range of 1 to 200 Hz, are assumed to be present during all facility operations. Each structure described in this paper will be required to achieve and maintain 0.6 {micro}rad ms laser beam pointing stability for a minimum of 2 hours under these vibration levels. To date, finite element (FE) analysis has been performed on a number of the beam transport structures. Certain assumptions have to be made regarding structural uncertainties in the FE models. These uncertainties consist of damping values for concrete and steel, compliance within bolted and welded joints, and assumptions regarding the phase coherence of ground motion components. In this paper, the influence of these structural uncertainties on the predicted pointing stability of the beam line transport structures as determined by random vibration analysis will be discussed.
Scaling between Structural Relaxation and Particle Caging in a Model Colloidal Gel
Cristiano De Michele; Emanuela Del Gado; Dino Leporini
2010-09-08
In polymers melts and supercooled liquids, the glassy dynamics is characterized by the rattling of monomers or particles in the cage formed by their neighbors. Recently, a direct correlation in such systems, described by a universal scaling form, has been established between the rattling amplitude and the structural relaxation time. In this paper we analyze the glassy dynamics emerging from the formation of a persistent network in a model colloidal gel at very low density. The structural relaxation time of the gel network is compared with the mean squared displacement at short times, corresponding to the localization length associated to the presence of energetic bonds. Interestingly, we find that the same type of scaling as for the dense glassy systems holds. Our findings well elucidate the strong coupling between the cooperative rearrangements of the gel network and the single particle localization in the structure. Our results further indicate that the scaling captures indeed fundamental physical elements of glassy dynamics.
Numerical modeling of roll structures in mesoscale vortexes over the Black Sea
Iarova, D A
2014-01-01
This paper is a case study of horizontal atmospheric rolls that formed over the Black Sea on 16 August 2007. The rolls were discovered in WRF modeling results for a mesoscale cyclone that originated over the sea on 15 August 2007. The roll formation mechanisms, such as Rayleigh-Benard convective instability, dynamic instability, advection and stretching of vertical velocity field inhomogeneities, are considered. It is shown that indeed convective instability played an important role in the roll formation but dynamic instability did not occur. In order to distinguish other possible mechanisms of the roll formation numerical experiments were performed. In these experiments sea surface temperature in the initial conditions was decreased in order to prevent convective instability. Even though convective instability was suppressed roll-like structures still appeared in the modeling results, although their height and circulation velocity were smaller than in the control run. It was found that these structures were ...
Macroscale modeling and mesoscale observations of plasma density structures in the polar cap
Basu, S.; Basu, S.; Sojka, J.J.; Schunk, R.W.; MacKenzie, E.
1995-04-15
The seasonal and UT variation of mesoscale structures (10 km - 100 m) in the central polar cap has been obtained from an analysis of 250-MHz intensity scintillation observations made at Thule, Greenland. It has been established earlier that mesoscale structures causing scintillations of satellite signals may develop at the edges of macroscale structures (several hundred km) such as discrete polar cap plasma density enhancements or patches through the gradient drift instability process. As such, the authrs examined the seasonal and UT variation of polar cap patches simulated by using the USU Time Dependent Ionospheric Model (TDIM) under conditions of southward B(sub z). A fairly remarkable similarity is found between the scintillation observations and the model predictions of patch occurrence. For instance, both the patch and scintillation occurrences are minimized during the winter solstice (northern hemisphere) between 0800-1200 UT while also having their largest seasonal intensity between 2000-2400 UT. Little UT dependence of patches and scintillations is seen at equinox with high intensity being observed throughout the day, while during local summer the intensity of macroscale patches and mesoscale irregularities are found to be a minimum at all UT. These results indicate that macroscale features in the polar cap are routinely associated with plasma instabilities giving rise to smaller scale structures and that the specific patch formation mechanism assumed in the simulation is consistent with the observations.
Coles, Jeffrey L.; Lemmon, Michael L.; Meschke, Felix
2012-01-01
Jeffrey L. Coles Arizona State University (ASU) - Finance Department Michael L. Lemmon University of Utah - Department of Finance Felix Meschke University of Kansas - Finance Area This version: April 14, 2011 Paper citation: Jeffrey L.... Coles, Michael L. Lemmon, J. Felix Meschke, Structural models and endogeneity in corporate finance: The link between managerial ownership and corporate performance, Journal of Financial Economics, Volume 103, Issue 1, January 2012, Pages 149-168, ISSN...
Powers, Robert
Homology Model for Oncostatin M Based on NMR Structural Data Douglas Kitchen,,§ Ross C. Hoffman-ray structure, creating homology models may prove to be the most efficient means of providing structural data model for OM was determined from the X-ray structures of human growth hormone (hGH), LIF, and G
Jie Peng; Zhongzhou Ren; Haitao Yang; Guangjie Guo; Xin Zhang; Guoxing Ju; Xiaoyong Guo; Chaosheng Deng; Guolin Hao
2015-01-27
We have found the algebraic structure of the two-qubit quantum Rabi model behind the possibility of its novel quasi-exact solutions with finite photon numbers by analyzing the Hamiltonian in the photon number space. The quasi-exact eigenstates with at most $1$ photon exist in the whole qubit-photon coupling regime with constant eigenenergy equal to single photon energy \\hbar\\omega, which can be clear demonstrated from the Hamiltonian structure. With similar method, we find these special "dark states"-like eigenstates commonly exist for the two-qubit Jaynes-Cummings model, with $E=N\\hbar\\omega$ (N=-1,0,1,...), and one of them is also the eigenstate of the two-qubit quantum Rabi model, which may provide some interesting application in a simper way. Besides, using Bogoliubov operators, we analytically retrieve the solution of the general two-qubit quantum Rabi model. In this more concise and physical way, without using Bargmann space, we clearly see how the eigenvalues of the infinite-dimensional two-qubit quantum Rabi Hamiltonian are determined by convergent power series, so that the solution can reach arbitrary accuracy reasonably because of the convergence property.
First Structure Formation: I. Primordial Star Forming Regions in hierarchical models
Tom Abel; Peter Anninos; Michael L. Norman; Yu Zhang
1997-05-17
We investigate the possibility of very early formation of primordial star clusters from high-\\sigma perturbations in cold dark matter dominated structure formation scenarios. For this we have developed a powerful 2-level hierarchical cosmological code with a realistic and robust treatment of multi-species primordial gas chemistry, paying special attention to the formation and destruction of hydrogen molecules, non-equilibrium ionization, and cooling processes. We performed 3-D simulations at small scales and at high redshifts and find that, analogous to simulations of large scale structure, a complex system of filaments, sheets, and spherical knots at the intersections of filaments form. On the mass scales covered by our simulations (5x10^5 - 1x10^9\\Ms) that collapse at redshifts z>25, we find that only at the spherical knots can enough H2 be formed (n_{H_2}/n_H > 5x10^-4) to cool the gas appreciably. Quantities such as the time dependence of the formation of H2 molecules, the final H2 fraction, and central densities from the simulations are compared to the theoretical predictions of Abel (1995) and Tegmark et al. (1997) and found to agree remarkably well. Comparing the 3-D results to an isobaric collapse model we further discuss the possible implications of the extensive merging of small structure that is inherent in hierarchical models. Typically only 5-8% percent of the total baryonic mass in the collapsing structures is found to cool significanlty. Assuming the Padoan (1995) model for star formation our results would predict the first stellar systems to be as small as ~30\\Ms. Some implications for primordial globular cluster formation scenarios are also discussed.
Nonlinear waves and coherent structures in the quantum single-wave model
Tzenov, Stephan I. [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom); Marinov, Kiril B. [ASTeC, STFC Daresbury Laboratory, Keckwick Lane, Daresbury WA4 4AD (United Kingdom)
2011-10-15
Starting from the von Neumann-Maxwell equations for the Wigner quasi-probability distribution and for the self-consistent electric field, the quantum analog of the classical single-wave model has been derived. The linear stability of the quantum single-wave model has been studied, and periodic in time patterns have been found both analytically and numerically. In addition, some features of quantum chaos have been detected in the unstable region in parameter space. Further, a class of standing-wave solutions of the quantum single-wave model has also been found, which have been observed to behave as stable solitary-wave structures. The analytical results have been finally compared to the exact system dynamics obtained by solving the corresponding equations in Schrodinger representation numerically.
Skolski, J. Z. P., E-mail: j.z.p.skolski@utwente.nl; Vincenc Obona, J. [Materials innovation institute M2i, Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Römer, G. R. B. E.; Huis in 't Veld, A. J. [Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)
2014-03-14
A model predicting the formation of laser-induced periodic surface structures (LIPSSs) is presented. That is, the finite-difference time domain method is used to study the interaction of electromagnetic fields with rough surfaces. In this approach, the rough surface is modified by “ablation after each laser pulse,” according to the absorbed energy profile, in order to account for inter-pulse feedback mechanisms. LIPSSs with a periodicity significantly smaller than the laser wavelength are found to “grow” either parallel or orthogonal to the laser polarization. The change in orientation and periodicity follow from the model. LIPSSs with a periodicity larger than the wavelength of the laser radiation and complex superimposed LIPSS patterns are also predicted by the model.
A nonlocal model for fluid-structure interaction with applications in hydraulic fracturing
Turner, Daniel Z
2012-01-01
Modeling important engineering problems related to flow-induced damage (in the context of hydraulic fracturing among others) depends critically on characterizing the interaction of porous media and interstitial fluid flow. This work presents a new formulation for incorporating the effects of pore pressure in a nonlocal representation of solid mechanics. The result is a framework for modeling fluid-structure interaction problems with the discontinuity capturing advantages of an integral based formulation. A number of numerical examples are used to show that the proposed formulation can be applied to measure the effect of leak-off during hydraulic fracturing as well as modeling consolidation of fluid saturated rock and surface subsidence caused by fluid extraction from a geologic reservoir. The formulation incorporates the effect of pore pressure in the constitutive description of the porous material in a way that is appropriate for nonlinear materials, easily implemented in existing codes, straightforward in i...
Nguyen, Ba Nghiep; Jin, Xiaoshi; Wang, Jin; Kunc, Vlastimil; Tucker III, Charles L.
2012-02-23
This report describes the work conducted under the CRADA Nr. PNNL/304 between Battelle PNNL and Autodesk whose objective is to validate the new process models developed under the previous CRADA for large injection-molded LFT composite structures. To this end, the ARD-RSC and fiber length attrition models implemented in the 2013 research version of Moldflow was used to simulate the injection molding of 600-mm x 600-mm x 3-mm plaques from 40% glass/polypropylene (Dow Chemical DLGF9411.00) and 40% glass/polyamide 6,6 (DuPont Zytel 75LG40HSL BK031) materials. The injection molding was performed by Injection Technologies, Inc. at Windsor, Ontario (under a subcontract by Oak Ridge National Laboratory, ORNL) using the mold offered by the Automotive Composite Consortium (ACC). Two fill speeds under the same back pressure were used to produce plaques under slow-fill and fast-fill conditions. Also, two gating options were used to achieve the following desired flow patterns: flows in edge-gated plaques and in center-gated plaques. After molding, ORNL performed measurements of fiber orientation and length distributions for process model validations. The structure of this report is as follows. After the Introduction (Section 1), Section 2 provides a summary of the ARD-RSC and fiber length attrition models. A summary of model implementations in the latest research version of Moldflow is given in Section 3. Section 4 provides the key processing conditions and parameters for molding of the ACC plaques. The validations of the ARD-RSC and fiber length attrition models are presented and discussed in Section 5. The conclusions will be drawn in Section 6.
Chen Duan [Department of Mathematics, Michigan State University, East Lansing, MI 48824 (United States); Wei Guowei [Department of Mathematics, Michigan State University, East Lansing, MI 48824 (United States); Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824 (United States)], E-mail: wei@math.msu.edu
2010-06-20
The miniaturization of nano-scale electronic devices, such as metal oxide semiconductor field effect transistors (MOSFETs), has given rise to a pressing demand in the new theoretical understanding and practical tactic for dealing with quantum mechanical effects in integrated circuits. Modeling and simulation of this class of problems have emerged as an important topic in applied and computational mathematics. This work presents mathematical models and computational algorithms for the simulation of nano-scale MOSFETs. We introduce a unified two-scale energy functional to describe the electrons and the continuum electrostatic potential of the nano-electronic device. This framework enables us to put microscopic and macroscopic descriptions in an equal footing at nano-scale. By optimization of the energy functional, we derive consistently coupled Poisson-Kohn-Sham equations. Additionally, layered structures are crucial to the electrostatic and transport properties of nano-transistors. A material interface model is proposed for more accurate description of the electrostatics governed by the Poisson equation. Finally, a new individual dopant model that utilizes the Dirac delta function is proposed to understand the random doping effect in nano-electronic devices. Two mathematical algorithms, the matched interface and boundary (MIB) method and the Dirichlet-to-Neumann mapping (DNM) technique, are introduced to improve the computational efficiency of nano-device simulations. Electronic structures are computed via subband decomposition and the transport properties, such as the I-V curves and electron density, are evaluated via the non-equilibrium Green's functions (NEGF) formalism. Two distinct device configurations, a double-gate MOSFET and a four-gate MOSFET, are considered in our three-dimensional numerical simulations. For these devices, the current fluctuation and voltage threshold lowering effect induced by the discrete dopant model are explored. Numerical convergence and model well-posedness are also investigated in the present work.
Thermodynamics and Structural Properties of the High Density Gaussian Core Model
Atsushi Ikeda; Kunimasa Miyazaki
2011-07-20
We numerically study thermodynamic and structural properties of the one-component Gaussian core model (GCM) at very high densities. The solid-fluid phase boundary is carefully determined. We find that the density dependence of both the freezing and melting temperatures obey the asymptotic relation, $\\log T_f$, $\\log T_m \\propto -\\rho^{2/3}$, where $\\rho$ is the number density, which is consistent with Stillinger's conjecture. Thermodynamic quantities such as the energy and pressure and the structural functions such as the static structure factor are also investigated in the fluid phase for a wide range of temperature above the phase boundary. We compare the numerical results with the prediction of the liquid theory with the random phase approximation (RPA). At high temperatures, the results are in almost perfect agreement with RPA for a wide range of density, as it has been already shown in the previous studies. In the low temperature regime close to the phase boundary line, although RPA fails to describe the structure factors and the radial distribution functions at the length scales of the interparticle distance, it successfully predicts their behaviors at shorter length scales. RPA also predicts thermodynamic quantities such as the energy, pressure, and the temperature at which the thermal expansion coefficient becomes negative, almost perfectly. Striking ability of RPA to predict thermodynamic quantities even at high densities and low temperatures is understood in terms of the decoupling of the length scales which dictate thermodynamic quantities from the interparticle distance which dominates the peak structures of the static structure factor due to the softness of the Gaussian core potential.
Jones, Peter JS
3D modelling of forest canopy structure for remote sensing simulations in the optical and microwave) and backscatter (microwave) signals measured remotely. We show it is feasible to model forest canopy scattering were used to drive optical and microwave models of canopy scattering. Simulated canopy radiometric
Influence of the plasma environment on atomic structure using an ion-sphere model
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Belkhiri, Madeny Jean; Fontes, Christopher John; Poirier, Michel
2015-09-03
Plasma environment effects on atomic structure are analyzed using various atomic structure codes. To monitor the effect of high free-electron density or low temperatures, Fermi-Dirac and Maxwell-Boltzmann statistics are compared. After a discussion of the implementation of the Fermi-Dirac approach within the ion-sphere model, several applications are considered. In order to check the consistency of the modifications brought here to extant codes, calculations have been performed using the Los Alamos Cowan Atomic Structure (cats) code in its Hartree-Fock or Hartree-Fock-Slater form and the parametric potential Flexible Atomic Code (fac). The ground-state energy shifts due to the plasma effects for themore »six most ionized aluminum ions have been calculated using the fac and cats codes and fairly agree. For the intercombination resonance line in Fe22+, the plasma effect within the uniform electron gas model results in a positive shift that agrees with the MCDF value of B. Saha et al.« less
Fluid-Structure Interaction Modeling of High-Aspect Ratio Nuclear Fuel Plates Using COMSOL
Curtis, Franklin G [ORNL] [ORNL; Ekici, Kivanc [ORNL] [ORNL; Freels, James D [ORNL] [ORNL
2013-01-01
The High Flux Isotope Reactor at the Oak Ridge National Lab is in the research stage of converting its fuel from high-enriched uranium to low-enriched uranium. Due to different physical properties of the new fuel and changes to the internal fuel plate design, the current safety basis must be re-evaluated through rigorous computational analyses. One of the areas being explored is the fluid-structure interaction phenomenon due to the interaction of thin fuel plates (50 mils thickness) and the cooling fluid (water). Detailed computational fluid dynamics and fluid-structure interaction simulations have only recently become feasible due to improved numerical algorithms and advancements in computing technology. For many reasons including the already built-in fluid-structure interaction module, COMSOL has been chosen for this complex problem. COMSOL's ability to solve multiphysics problems using a fully-coupled and implicit solution algorithm is crucial in obtaining a stable and accurate solution. Our initial findings show that COMSOL can accurately model such problems due to its ability to closely couple the fluid dynamics and the structural dynamics problems.
Non-equilibrium structure and dynamics in a microscopic model of thin film active gels
D. A. Head; W. J. Briels; G. Gompper
2014-02-26
In the presence of ATP, molecular motors generate active force dipoles that drive suspensions of protein filaments far from thermodynamic equilibrium, leading to exotic dynamics and pattern formation. Microscopic modelling can help to quantify the relationship between individual motors plus filaments to organisation and dynamics on molecular and supra-molecular length scales. Here we present results of extensive numerical simulations of active gels where the motors and filaments are confined between two infinite parallel plates. Thermal fluctuations and excluded-volume interactions between filaments are included. A systematic variation of rates for motor motion, attachment and detachment, including a differential detachment rate from filament ends, reveals a range of non-equilibrium behaviour. Strong motor binding produces structured filament aggregates that we refer to as asters, bundles or layers, whose stability depends on motor speed and differential end-detachment. The gross features of the dependence of the observed structures on the motor rate and the filament concentration can be captured by a simple one-filament model. Loosely bound aggregates exhibit super-diffusive mass transport, where filament translocation scales with lag time with non-unique exponents that depend on motor kinetics. An empirical data collapse of filament speed as a function of motor speed and end-detachment is found, suggesting a dimensional reduction of the relevant parameter space. We conclude by discussing the perspectives of microscopic modelling in the field of active gels.
The fixed structurally robust internal model principle for linear multivariable regulators
McGrath, John Thomas
1980-01-01
for the degree of I'V. STER OF S"IENCE Vay 1980 Va jor Sub jec ~: Elec+r ical Engineering THE FIXED STRUCTURALLY ROBUST INTERNAL MODEL PRINCIPLE FOR LINEAR MULTIVARIABLE REGUIATORS A Thesis by JOHN THOMAS MCGRATH Aoproved as to style and content by... Multivariable Regulators. (May 19BC) John Thomas McGrath, B. S. , Texas ARM Unive sity Chairman of Advisory Committee: Dr. Ralph Keary Cavin III In this paper we develop the necessary and suffi- cient cond'tions to establish the new concept of' a fixed...
- Composition & configuration of forest structural attributes Keystone Structures e.g. dead wood `Habitat. Animal species diversity driven by habitat heterogeneity/diversity: The importance of keystone structures
Mooijaart, Ab; Satorra, Albert
2011-01-01
of-?t summaries for the MM method degrees of freedom chi-regarding the robustness of the MM method to non-normality.MM versus ML estimates of structural equation models with
Modeling the large-scale structure of a barchan dune field
Worman, S; Littlewood, R; Andreotti, B; Claudin, P
2013-01-01
In nature, barchan dunes typically exist as members of larger fields that display enigmatic structures that cannot be readily explained by external forcing. To explore the possibility that observed patterns self-organize, we built a numerical model that treats barchans as discrete entities that obey known empirical relationships and interact with one another according to simplified rules derived from theoretical and numerical work, and from field observations. A rich array of patterns, similar to those observed in nature, emerge from these relatively simple behaviors and interactions, offering a cohesive depiction and a potential explanation of field-scale phenomena. This is the first model to integrate calving and results support the hypothesis that it exerts a first order control on the system; It is fundamental to the formation and stability of field patterns and when the process is disabled, all dunes in all runs grow without bound on short time-scales. Insights derived from this synthesis of dune-scale p...
Monte Carlo study of Lefschetz thimble structure in one-dimensional Thirring model at finite density
Fujii, Hirotsugu; Kikukawa, Yoshio
2015-01-01
We consider the one-dimensional massive Thirring model formulated on the lattice with staggered fermions and an auxiliary compact vector (link) field, which is exactly solvable and shows a phase transition with increasing the chemical potential of fermion number: the crossover at a finite temperature and the first order transition at zero temperature. We complexify its path-integration on Lefschetz thimbles and examine its phase transition by hybrid Monte Carlo simulations on the single dominant thimble. We observe a discrepancy between the numerical and exact results in the crossover region for small inverse coupling $\\beta$ and/or large lattice size $L$, while they are in good agreement at the lower and higher density regions. We also observe that the discrepancy persists in the continuum limit keeping the temperature finite and it becomes more significant toward the low-temperature limit. This numerical result is consistent with our analytical study of the model's thimble structure. And these results imply...
Baudouin, Lucie
A controlled distributed parameter model for a fluid-flexible structure system: numerical consider the problem of active reduction of vibrations in a fluid-flexible structure system and the sloshing of the fuel inside the wing's tank. The control is performed using piezoelectric patches
Nowack, Robert L.
Velocity and Attenuation Structure of the Tibetan Lithosphere Under the Hi-CLIMB Array From earthquakes in Tibet recorded by the Hi-CLIMB experiment, Pn attributes are used to constrain the velocity gradient and attenuation structure of the Tibetan lithosphere under the Hi-CLIMB array. Numerical modeling
Istrail, Sorin
Lattice and Off-Lattice Side Chain Models of Protein Folding: Linear Time Structure Prediction This paper considers the protein structure prediction problem for lattice and off-lattice protein folding tools for reasoning about protein folding in unrestricted continuous space through anal- ogy. This paper
Shi, Ya-Zhou; Wang, Feng-Hua; Wu, Yuan-Yan; Tan, Zhi-Jie
2014-09-14
To bridge the gap between the sequences and 3-dimensional (3D) structures of RNAs, some computational models have been proposed for predicting RNA 3D structures. However, the existed models seldom consider the conditions departing from the room/body temperature and high salt (1M NaCl), and thus generally hardly predict the thermodynamics and salt effect. In this study, we propose a coarse-grained model with implicit salt for RNAs to predict 3D structures, stability, and salt effect. Combined with Monte Carlo simulated annealing algorithm and a coarse-grained force field, the model folds 46 tested RNAs (?45 nt) including pseudoknots into their native-like structures from their sequences, with an overall mean RMSD of 3.5 Å and an overall minimum RMSD of 1.9 Å from the experimental structures. For 30 RNA hairpins, the present model also gives the reliable predictions for the stability and salt effect with the mean deviation ? 1.0 °C of melting temperatures, as compared with the extensive experimental data. In addition, the model could provide the ensemble of possible 3D structures for a short RNA at a given temperature/salt condition.
Modeling of the magnetic properties of nanomaterials with different crystalline structure
Yury Kirienko; Leonid Afremov
2013-01-13
We propose a method for modeling the magnetic properties of nanomaterials with different structures. The method is based on the Ising model and the approximation of the random field interaction. It is shown that in this approximation, the magnetization of the nanocrystal depends only on the number of nearest neighbors of the lattice atoms and the values of exchange integrals between them. This gives a good algorithmic problem of calculating the magnetization of any nano-object, whether it is ultrathin film or nanoparticle of any shape and structure, managing only a rule of selection of nearest neighbors. By setting different values of exchange integrals, it is easy to describe ferromagnets, antiferromagnets, and ferrimagnets in a unified formalism. Having obtained the magnetization curve of the sample it is possible to find the Curie temperature as a function of, for example, the thickness of ultrathin film. Afterwards one can obtain the numerical values for critical exponents of the phase transition "ferromagnet -- paramagnet". Good agreement between the results of calculations and the experimental data proves the correctness of the method.
Klein, M.T.; Korre, S.C.; Read, C.J.; Russell, C.L. [Univ. of Deleware, Newark, DE (United States)
1993-12-31
Heavy oil catalytic hydrocracking is a flexible refining process aimed at increasing the hydrogen-to-carbon ratio, while at the same time decreasing the molecular weight of heavy oils. Reliable information on kinetics, pathways and mechanisms is scarce because of the complexity of the feed that obscures reactant structure. The authors have thus sought to introduce the reactant structure through model compound experiments. The reactants were selected in order to sample the basic structural attributes of heavy oils - the total number of rings, the numbers of aromatic rings and the extent of alkyl substitution. The pathways of hydrocracking bare-ring compounds consist of hydrogenation of an aromatic ring, isomerization of the resulting cyclohexyl moiety to a metyl cyclopentyl moiety, ring opening to a butyl side chain, and dealkylation of the side chain at various positions. This ring-by-ring procedure is repeated a new until alkyl benzenes were produced. The authors have extended this reaction family notion to efficiently organize kinetic information in terms of linear free energy relationships. The authors have also studied a more efficient way of cleavage of polynuclear aromatics, where to molecules of alkyl benzenes are produced from one molecule with {>=}3 rings. Certain alkyl biphenyl moieties have been found to undergo this selective cleavage. Additionally, dealkylation pathways and kinetics have been further examined by experiments with long-alkyl substituted compounds (C{sub 4}-C{sub 15}). These results are expected to enhance the understanding of heavy oil hydrocracking and contribute to process modeling and optimization, with special emphasis on product properties.
HOT X-RAY CORONAE AROUND MASSIVE SPIRAL GALAXIES: A UNIQUE PROBE OF STRUCTURE FORMATION MODELS
Bogdan, Akos; Forman, William R.; Vogelsberger, Mark; Sijacki, Debora; Mazzotta, Pasquale; Kraft, Ralph P.; Jones, Christine; David, Laurence P. [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bourdin, Herve [Dipartimento di Fisica, Universita degli Studi di Roma 'Tor Vergata', via della Ricerca Scientifica 1, I-00133 Roma (Italy); Gilfanov, Marat; Churazov, Eugene, E-mail: abogdan@cfa.harvard.edu [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-str. 1, D-85748 Garching (Germany)
2013-08-01
Luminous X-ray gas coronae in the dark matter halos of massive spiral galaxies are a fundamental prediction of structure formation models, yet only a few such coronae have been detected so far. In this paper, we study the hot X-ray coronae beyond the optical disks of two 'normal' massive spirals, NGC 1961 and NGC 6753. Based on XMM-Newton X-ray observations, hot gaseous emission is detected to {approx}60 kpc-well beyond their optical radii. The hot gas has a best-fit temperature of kT {approx} 0.6 keV and an abundance of {approx}0.1 Solar, and exhibits a fairly uniform distribution, suggesting that the quasi-static gas resides in hydrostatic equilibrium in the potential well of the galaxies. The bolometric luminosity of the gas in the (0.05-0.15)r{sub 200} region (r{sub 200} is the virial radius) is {approx}6 Multiplication-Sign 10{sup 40} erg s{sup -1} for both galaxies. The baryon mass fractions of NGC 1961 and NGC 6753 are f{sub b,NGC1961} {approx} 0.11 and f{sub b,NGC6753} {approx} 0.09, which values fall short of the cosmic baryon fraction. The hot coronae around NGC 1961 and NGC 6753 offer an excellent basis to probe structure formation simulations. To this end, the observations are confronted with the moving mesh code AREPO and the smoothed particle hydrodynamics code GADGET. Although neither model gives a perfect description, the observed luminosities, gas masses, and abundances favor the AREPO code. Moreover, the shape and the normalization of the observed density profiles are better reproduced by AREPO within {approx}0.5r{sub 200}. However, neither model incorporates efficient feedback from supermassive black holes or supernovae, which could alter the simulated properties of the X-ray coronae. With the further advance of numerical models, the present observations will be essential in constraining the feedback effects in structure formation simulations.
FLUID-STRUCTURE INTERACTION MODELS OF THE MITRAL VALVE: FUNCTION IN NORMAL AND PATHOLOGIC STATES
Kunzelman, K. S.; Einstein, Daniel R.; Cochran, R. P.
2007-08-29
Successful mitral valve repair is dependent upon a full understanding of normal and abnormal mitral valve anatomy and function. Computational analysis is one such method that can be applied to simulate mitral valve function in order to analyze the roles of individual components, and evaluate proposed surgical repair. We developed the first three-dimensional, finite element (FE) computer model of the mitral valve including leaflets and chordae tendineae, however, one critical aspect that has been missing until the last few years was the evaluation of fluid flow, as coupled to the function of the mitral valve structure. We present here our latest results for normal function and specific pathologic changes using a fluid-structure interaction (FSI) model. Normal valve function was first assessed, followed by pathologic material changes in collagen fiber volume fraction, fiber stiffness, fiber splay, and isotropic stiffness. Leaflet and chordal stress and strain, and papillary muscle force was determined. In addition, transmitral flow, time to leaflet closure, and heart valve sound were assessed. Model predictions in the normal state agreed well with a wide range of available in-vivo and in-vitro data. Further, pathologic material changes that preserved the anisotropy of the valve leaflets were found to preserve valve function. By contrast, material changes that altered the anisotropy of the valve were found to profoundly alter valve function. The addition of blood flow and an experimentally driven microstructural description of mitral tissue represent significant advances in computational studies of the mitral valve, which allow further insight to be gained. This work is another building block in the foundation of a computational framework to aid in the refinement and development of a truly noninvasive diagnostic evaluation of the mitral valve. Ultimately, it represents the basis for simulation of surgical repair of pathologic valves in a clinical and educational setting.
Droegemeier, Kelvin K.
On the Vertical Structure of Modeled and Observed Deep Convective Storms: Insights-GEORGIOU, AND VENUGOPAL VURUPUTUR Saint Anthony Falls Laboratory, Department of Civil Engineering, University of Minnesota of hydrometeors (liquid and frozen water droplets in a cloud) produced by high-resolution NWP models with explicit
Benning, Liane G.
Neutron and X-ray diffraction and empirical potential structure refinement modelling of magnesium online xxxx Keywords: Amorphous calcium carbonate; EPSR modelling; Neutron diffraction; X-ray diffraction Amorphous calcium carbonate (ACC) plays a key role in biomineralisation processes in sea organisms. Neutron
Margraf, J
2012-06-12
This report primarily concerns the use of two massively parallel finite element codes originally written and maintained at Lawrence Livermore National Laboratory. ALE3D is an explicit hydrodynamics code commonly employed to simulate wave propagation from high energy scenarios and the resulting interaction with nearby structures. This coupled response ensures that a structure is accurately applied with a blast loading varying both in space and time. Figure 1 illustrates the radial outward propagation of a pressure wave due to a center detonated spherical explosive originating from the lower left. The radial symmetry seen in this scenario is lost when instead a cylindrocal charge is detonated. Figure 2 indicates that a stronger, faster traveling pressure wave occurs in the direction of the normal axis to the cylinder. The ALE3D name is derived because of the use of arbitrary-Lagrange-Eulerian elements in which the mesh is allowed to advect; a process through which the mesh is modified to alleviate tanlging and general mesh distortion often cuased by high energy scenarios. The counterpart to an advecting element is a Lagrange element, whose mesh moves with the material. Ideally all structural components are kept Lagrange as long as possible to preserve accuracy of material variables and minimize advection related errors. Advection leads to mixed zoning, so using structural Lagrange elements also improves the visualization when post processing the results. A simplified representation of the advection process is shown in Figure 3. First the mesh is distorted due to material motion during the Lagrange step. The mesh is then shifted to an idealized and less distorted state to prevent irregular zones caused by the Lagrange motion. Lastly, the state variables are remapped to the elements of the newly constructed mesh. Note that Figure 3 represents a purely Eulerian mesh relaxation because the mesh is relocated back to the pre-Lagrange position. This is the case when the material flows through a still mesh. This is not typically done in an ALE3D analysis, especially if Lagrange elements exist. Deforming Lagrange elements would certainly tangle with a Eulerian mesh eventually. The best method in this case is to have an advecting mesh positioned as some relaxed version of the pre and post Lagrange step; this gives the best opportunity of modeling a high energy event with a combination of Lagrange and ALE elements. Dyne3D is another explicit dynamic analysis code, ParaDyn being the parallel version. ParaDyn is used for predicting the transient response of three dimensional structures using Lagrangian solid mechanics. Large deformation and mesh tangling is often resolved through the use of an element deletion scheme. This is useful to accommodate component failure, but if it is done purely as a means to preserve a useful mesh it can lead to problems because it does not maintain continuity of the material bulk response. Whatever medium exists between structural components is typically not modeled in ParaDyn. Instead, a structure either has a known loading profile applied or given initial conditions. The many included contact algorithms can calculate the loading response of materials if and when they collide. A recent implementation of an SPH module in which failed or deleted material nodes are converted to independent particles is currently being utilized for a variety of spall related problems and high velocity impact scenarios. Figure 4 shows an example of a projectile, given an initial velocity, and how it fails the first plate which generates SPH particles which then interact with and damage the second plate.
Kandemir, Zafer; Bulut, Nejat
2015-01-01
We study the electronic structure and correlations of vitamin B12 (cyanocobalamine) by using the framework of the multi-orbital single-impurity Haldane-Anderson model of a transition-metal impurity in a semiconductor host. In this approach, the cobalt 3d orbitals are treated as the impurity states placed in a semiconductor host where the host consists of the rest of the molecule. The parameters of the resulting effective Haldane-Anderson model are obtained within the Hartree-Fock (HF) approximation. The quantum Monte Carlo (QMC) technique is then used to calculate the one-electron and magnetic correlation functions of this effective model. We observe that new states form inside the semiconductor gap found by HF due to the intra-orbital Coulomb interaction at the impurity 3d orbitals. In particular, the lowest unoccupied states correspond to an impurity bound state, which consists of the states from the CN axial ligand and the corring ring as well as the Co e_g orbitals. We present results on the charge distri...
Nguyen, Ba Nghiep; Bapanapalli, Satish K.; Smith, Mark T.; Kunc, Vlastimil; Frame, Barbara; Norris, Robert E.; Phelps, Jay; Tucker III, Charles L.; Jin, Xiaoshi; Wang, Jin
2008-09-01
The objective of our work is to enable the optimum design of lightweight automotive structural components using injection-molded long fiber thermoplastics (LFTs). To this end, an integrated approach that links process modeling to structural analysis with experimental microstructural characterization and validation is developed. First, process models for LFTs are developed and implemented into processing codes (e.g. ORIENT, Moldflow) to predict the microstructure of the as-formed composite (i.e. fiber length and orientation distributions). In parallel, characterization and testing methods are developed to obtain necessary microstructural data to validate process modeling predictions. Second, the predicted LFT composite microstructure is imported into a structural finite element analysis by ABAQUS to determine the response of the as-formed composite to given boundary conditions. At this stage, constitutive models accounting for the composite microstructure are developed to predict various types of behaviors (i.e. thermoelastic, viscoelastic, elastic-plastic, damage, fatigue, and impact) of LFTs. Experimental methods are also developed to determine material parameters and to validate constitutive models. Such a process-linked-structural modeling approach allows an LFT composite structure to be designed with confidence through numerical simulations. Some recent results of our collaborative research will be illustrated to show the usefulness and applications of this integrated approach.
Goddard III, William A.
The Structure of Water in Crystalline Aluminophosphates: Isolated Water and Intermolecular Clusters are used to elucidate the properties of water in Metavariscite, AlPO4-H3, AlPO4-8 and VPI-5. The framework density of the aluminophosphates decreases along this sequence, the pore size increases, and the water
Fine structure in the large n limit of the non-hermitian Penner matrix model
Gabriel Álvarez; Luis Martínez Alonso; Elena Medina
2015-07-09
In this paper we apply results on the asymptotic zero distribution of the Laguerre polynomials to discuss generalizations of the standard large $n$ limit in the non-hermitian Penner matrix model. In these generalizations $g_n n\\to t$, but the product $g_n n$ is not necessarily fixed to the value of the 't Hooft coupling $t$. If $t>1$ and the limit $l = \\lim_{n\\rightarrow \\infty} |\\sin(\\pi/g_n)|^{1/n}$ exists, then the large $n$ limit is well-defined but depends both on $t$ and on $l$. This result implies that for $t>1$ the standard large $n$ limit with $g_n n=t$ fixed is not well-defined. The parameter $l$ determines a fine structure of the asymptotic eigenvalue support: for $l\
Two-dimensional phase structure of SU(2) gauge-Higgs model
Shinya Gongyo; Daniel Zwanziger
2014-10-30
We study the phase structure of SU(2) gauge-Higgs model in two dimensions using lattice simulations. We show the result for the plaquette expectation value, static potential, and W propagator. Our results suggest that a confinement-like region and a Higgs-like region appear even in two dimensions. The behavior of the plaquette expectation value is consistent with a smooth cross-over in accordance with the Fradkin-Shenker-Osterwalder-Seiler theorem. In the confinement-like region, the static potential seems to rise linearly with string breaking at large distances, while in the Higgs-like region there seems to be a massive behavior which means that the BEH mechanism occurs. The correlation length obtained from the W propagator has a finite maximum between these phases, which supports no second-order phase transition. Based on these results, we suggest that there is no phase transition in two dimensions.
Effect of Multiple Higgs Fields on the Phase Structure of the SU(2)-Higgs Model
Mark Wurtz; Randy Lewis; T. G. Steele
2009-07-29
The SU(2)-Higgs model, with a single Higgs field in the fundamental representation and a quartic self-interaction, has a Higgs region and a confinement region which are analytically connected in the parameter space of the theory; these regions thus represent a single phase. The effect of multiple Higgs fields on this phase structure is examined via Monte Carlo lattice simulations. For the case of N>=2 identical Higgs fields, there is no remaining analytic connection between the Higgs and confinement regions, at least when Lagrangian terms that directly couple different Higgs flavours are omitted. An explanation of this result in terms of enhancement from overlapping phase transitions is explored for N=2 by introducing an asymmetry in the hopping parameters of the Higgs fields. It is found that an enhancement of the phase transitions can still occur for a moderate (10%) asymmetry in the resulting hopping parameters.
The variation of the fine structure constant: testing the dipole model with thermonuclear supernovae
Kraiselburd, Lucila; Negrelli, Carolina; Berro, Enrique García
2014-01-01
The large-number hypothesis conjectures that fundamental constants may vary. Accordingly, the spacetime variation of fundamental constants has been an active subject of research for decades. Recently, using data obtained with large telescopes a phenomenological model in which the fine structure constant might vary spatially has been proposed. We test whether this hypothetical spatial variation of {\\alpha}, which follows a dipole law, is compatible with the data of distant thermonuclear supernovae. Unlike previous works, in our calculations we consider not only the variation of the luminosity distance when a varying {\\alpha} is adopted, but we also take into account the variation of the peak luminosity of Type Ia supernovae resulting from a variation of {\\alpha}. This is done using an empirical relation for the peak bolometric magnitude of thermonuclear supernovae that correctly reproduces the results of detailed numerical simulations. We find that there is no significant difference between the several phenome...
Stringy models of modified gravity: space-time defects and structure formation
Mavromatos, Nick E.; Sakellariadou, Mairi; Yusaf, Muhammad Furqaan, E-mail: nikolaos.mavromatos@kcl.ac.uk, E-mail: mairi.sakellariadou@kcl.ac.uk, E-mail: muhammad.yusaf@kcl.ac.uk [King's College London, Department of Physics, Strand, London WC2R 2LS (United Kingdom)
2013-03-01
Starting from microscopic models of space-time foam, based on brane universes propagating in bulk space-times populated by D0-brane defects (''D-particles''), we arrive at effective actions used by a low-energy observer on the brane world to describe his/her observations of the Universe. These actions include, apart from the metric tensor field, also scalar (dilaton) and vector fields, the latter describing the interactions of low-energy matter on the brane world with the recoiling point-like space-time defect (D-particle). The vector field is proportional to the recoil velocity of the D-particle and as such it satisfies a certain constraint. The vector breaks locally Lorentz invariance, which however is assumed to be conserved on average in a space-time foam situation, involving the interaction of matter with populations of D-particle defects. In this paper we clarify the role of fluctuations of the vector field on structure formation and galactic growth. In particular we demonstrate that, already at the end of the radiation era, the (constrained) vector field associated with the recoil of the defects provides the seeds for a growing mode in the evolution of the Universe. Such a growing mode survives during the matter dominated era, provided the variance of the D-particle recoil velocities on the brane is larger than a critical value. We note that in this model, as a result of specific properties of D-brane dynamics in the bulk, there is no issue of overclosing the brane Universe for large defect densities. Thus, in these models, the presence of defects may be associated with large-structure formation. Although our string inspired models do have (conventional, from a particle physics point of view) dark matter components, nevertheless it is interesting that the role of ''extra'' dark matter is also provided by the population of massive defects. This is consistent with the weakly interacting character of the D-particle defects, which predominantly interact only gravitationally.
Modeling the large-scale structure of a barchan dune field
S. Worman; A. B. Murray; R. Littlewood; B. Andreotti; P. Claudin
2013-07-12
In nature, barchan dunes typically exist as members of larger fields that display striking, enigmatic structures that cannot be readily explained by examining the dynamics at the scale of single dunes, or by appealing to patterns in external forcing. To explore the possibility that observed structures emerge spontaneously as a collective result of many dunes interacting with each other, we built a numerical model that treats barchans as discrete entities that interact with one another according to simplified rules derived from theoretical and numerical work and from field observations: (1) Dunes exchange sand through the fluxes that leak from the downwind side of each dune and are captured on their upstream sides; (2) when dunes become sufficiently large, small dunes are born on their downwind sides (`calving'); and (3) when dunes collide directly enough, they merge. Results show that these relatively simple interactions provide potential explanations for a range of field-scale phenomena including isolated patches of dunes and heterogeneous arrangements of similarly sized dunes in denser fields. The results also suggest that (1) dune field characteristics depend on the sand flux fed into the upwind boundary, although (2) moving downwind, the system approaches a common attracting state in which the memory of the upwind conditions vanishes. This work supports the hypothesis that calving exerts a first-order control on field-scale phenomena; it prevents individual dunes from growing without bound, as single-dune analyses suggest, and allows the formation of roughly realistic, persistent dune field patterns.
A Spectral Element Approach for Modeling of Wave-Based Structural Health Monitoring Systems
Schulte, Rolf T.; Fritzen, Claus-Peter [Institute of Mechanics and Control-Mechatronics, University of Siegen, Paul-Bonatz-Str. 9-11, 57076 Siegen (Germany)
2010-09-30
During the last decades, guided waves have shown great potential for Structural Health Monitoring (SHM) applications. These waves can be excited and sensed by piezoelectric elements that can be permanently attached onto a structure offering online monitoring capability. As the setup of wave based SHM systems may be very difficult and time consuming there is a growing demand for efficient simulation tools providing the opportunity to design wave based SHM systems in a virtual environment. As usually high frequency waves are used, the associated short wavelength leads to the necessity of a very dense mesh, which makes conventional finite elements not well suited for this purpose. Therefore a flat shell spectral element approach is presented in this contribution. By including electromechanical coupling an SHM system can be simulated entirely from actuator voltage to sensor voltage. The focus of this contribution is the analysis of the effect of delaminations on propagating waves. A forward increment Lagrange multiplier method is used to simulate contact within the delaminated area. A model validation is performed using measured data of an anisotropic CFRP-plate.
Hart, W.E.; Istrail, S. [Sandia National Labs., Albuquerque, NM (United States). Algorithms and Discrete Mathematics Dept.
1996-08-09
This paper considers the protein structure prediction problem for lattice and off-lattice protein folding models that explicitly represent side chains. Lattice models of proteins have proven extremely useful tools for reasoning about protein folding in unrestricted continuous space through analogy. This paper provides the first illustration of how rigorous algorithmic analyses of lattice models can lead to rigorous algorithmic analyses of off-lattice models. The authors consider two side chain models: a lattice model that generalizes the HP model (Dill 85) to explicitly represent side chains on the cubic lattice, and a new off-lattice model, the HP Tangent Spheres Side Chain model (HP-TSSC), that generalizes this model further by representing the backbone and side chains of proteins with tangent spheres. They describe algorithms for both of these models with mathematically guaranteed error bounds. In particular, the authors describe a linear time performance guaranteed approximation algorithm for the HP side chain model that constructs conformations whose energy is better than 865 of optimal in a face centered cubic lattice, and they demonstrate how this provides a 70% performance guarantee for the HP-TSSC model. This is the first algorithm in the literature for off-lattice protein structure prediction that has a rigorous performance guarantee. The analysis of the HP-TSSC model builds off of the work of Dancik and Hannenhalli who have developed a 16/30 approximation algorithm for the HP model on the hexagonal close packed lattice. Further, the analysis provides a mathematical methodology for transferring performance guarantees on lattices to off-lattice models. These results partially answer the open question of Karplus et al. concerning the complexity of protein folding models that include side chains.
Seismic Soil-Structure Interaction Analyses of a Deeply Embedded Model Reactor – SASSI Analyses
Nie J.; Braverman J.; Costantino, M.
2013-10-31
This report summarizes the SASSI analyses of a deeply embedded reactor model performed by BNL and CJC and Associates, as part of the seismic soil-structure interaction (SSI) simulation capability project for the NEAMS (Nuclear Energy Advanced Modeling and Simulation) Program of the Department of Energy. The SASSI analyses included three cases: 0.2 g, 0.5 g, and 0.9g, all of which refer to nominal peak accelerations at the top of the bedrock. The analyses utilized the modified subtraction method (MSM) for performing the seismic SSI evaluations. Each case consisted of two analyses: input motion in one horizontal direction (X) and input motion in the vertical direction (Z), both of which utilized the same in-column input motion. Besides providing SASSI results for use in comparison with the time domain SSI results obtained using the DIABLO computer code, this study also leads to the recognition that the frequency-domain method should be modernized so that it can better serve its mission-critical role for analysis and design of nuclear power plants.
Modeling precursor diffusion and reaction of atomic layer deposition in porous structures
Keuter, Thomas, E-mail: t.keuter@fz-juelich.de; Menzler, Norbert Heribert; Mauer, Georg; Vondahlen, Frank; Vaßen, Robert; Buchkremer, Hans Peter [Forschungszentrum Jülich, Institute of Energy and Climate Research (IEK-1), 52425 Jülich (Germany)
2015-01-01
Atomic layer deposition (ALD) is a technique for depositing thin films of materials with a precise thickness control and uniformity using the self-limitation of the underlying reactions. Usually, it is difficult to predict the result of the ALD process for given external parameters, e.g., the precursor exposure time or the size of the precursor molecules. Therefore, a deeper insight into ALD by modeling the process is needed to improve process control and to achieve more economical coatings. In this paper, a detailed, microscopic approach based on the model developed by Yanguas-Gil and Elam is presented and additionally compared with the experiment. Precursor diffusion and second-order reaction kinetics are combined to identify the influence of the porous substrate's microstructural parameters and the influence of precursor properties on the coating. The thickness of the deposited film is calculated for different depths inside the porous structure in relation to the precursor exposure time, the precursor vapor pressure, and other parameters. Good agreement with experimental results was obtained for ALD zirconiumdioxide (ZrO{sub 2}) films using the precursors tetrakis(ethylmethylamido)zirconium and O{sub 2}. The derivation can be adjusted to describe other features of ALD processes, e.g., precursor and reactive site losses, different growth modes, pore size reduction, and surface diffusion.
Effect of Divalent Cation Removal on the Structure of Gram-Negative Bacterial Outer Membrane Models
Clifton, Luke A.; Skoda, Maximilian W. A.; Le Brun, Anton P.; Ciesielski, Filip; Kuzmenko, Ivan; Holt, Stephen A.; Lakey, Jeremy H.
2014-12-09
The Gram-negative bacterial outer membrane (GNB-OM) is asymmetric in its lipid composition with a phospholipid-rich inner leaflet and an outer leaflet predominantly composed of lipopolysaccharides (LPS). LPS are polyanionic molecules, with numerous phosphate groups present in the lipid A and core oligosaccharide regions. The repulsive forces due to accumulation of the negative charges are screened and bridged by the divalent cations (Mg^{2+} and Ca^{2+}) that are known to be crucial for the integrity of the bacterial OM. Indeed, chelation of divalent cations is a well-established method to permeabilize Gram-negative bacteria such as Escherichia coli. Here, we use X-ray and neutron reflectivity (XRR and NR, respectively) techniques to examine the role of calcium ions in the stability of a model GNB-OM. Using XRR we show that Ca^{2+} binds to the core region of the rough mutant LPS (RaLPS) films, producing more ordered structures in comparison to divalent cation free monolayers. Using recently developed solid-supported models of the GNB-OM, we study the effect of calcium removal on the asymmetry of DPPC:RaLPS bilayers. We show that without the charge screening effect of divalent cations, the LPS is forced to overcome the thermodynamically unfavorable energy barrier and flip across the hydrophobic bilayer to minimize the repulsive electrostatic forces, resulting in about 20% mixing of LPS and DPPC between the inner and outer bilayer leaflets. These results reveal for the first time the molecular details behind the well-known mechanism of outer membrane stabilization by divalent cations. This confirms the relevance of the asymmetric models for future studies of outer membrane stability and antibiotic penetration.
Effect of Divalent Cation Removal on the Structure of Gram-Negative Bacterial Outer Membrane Models
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Clifton, Luke A.; Skoda, Maximilian W. A.; Le Brun, Anton P.; Ciesielski, Filip; Kuzmenko, Ivan; Holt, Stephen A.; Lakey, Jeremy H.
2014-12-09
The Gram-negative bacterial outer membrane (GNB-OM) is asymmetric in its lipid composition with a phospholipid-rich inner leaflet and an outer leaflet predominantly composed of lipopolysaccharides (LPS). LPS are polyanionic molecules, with numerous phosphate groups present in the lipid A and core oligosaccharide regions. The repulsive forces due to accumulation of the negative charges are screened and bridged by the divalent cations (Mg2+ and Ca2+) that are known to be crucial for the integrity of the bacterial OM. Indeed, chelation of divalent cations is a well-established method to permeabilize Gram-negative bacteria such as Escherichia coli. Here, we use X-ray and neutronmore »reflectivity (XRR and NR, respectively) techniques to examine the role of calcium ions in the stability of a model GNB-OM. Using XRR we show that Ca2+ binds to the core region of the rough mutant LPS (RaLPS) films, producing more ordered structures in comparison to divalent cation free monolayers. Using recently developed solid-supported models of the GNB-OM, we study the effect of calcium removal on the asymmetry of DPPC:RaLPS bilayers. We show that without the charge screening effect of divalent cations, the LPS is forced to overcome the thermodynamically unfavorable energy barrier and flip across the hydrophobic bilayer to minimize the repulsive electrostatic forces, resulting in about 20% mixing of LPS and DPPC between the inner and outer bilayer leaflets. These results reveal for the first time the molecular details behind the well-known mechanism of outer membrane stabilization by divalent cations. This confirms the relevance of the asymmetric models for future studies of outer membrane stability and antibiotic penetration.« less
Cronin, Kelly; Whyte, Catherine [University of California at Berkeley, Department of Civil and Environmental Engineering, 760 Davis Hall (United States); Reiner, Tom [Graduate Engineer, Buro Happold Consulting Engineers, Inc., 9601 Jefferson Blvd., Suite B, Culver City, CA 90232 (United States)
2008-07-08
Throughout the world there are hundreds of historic monuments and structures considered to be invaluable and irreplaceable. They are symbols of cultural identity and a means of educating people about history. Preservation of historic monuments and structures is therefore an important part of safeguarding these cultural heritage sites so that they retain their value for future generations.This report discusses a procedure for the investigation of seismic hazards in existing buildings and possible steps that can be taken to avoid damage caused by these hazards. The Augusta Airship Hangar located in Sicily, will be used as a case study however the topics addressed in this paper can be applied to other structures of historic value around the world.First state-of-the-art scanning procedures were used to create scale digital models that were imported into a structural analysis program. Within this program dynamic analyses were performed on the model based on actual ground motions taken close to the site. This data was used to determine the period and mode shapes of the structure. Then a nonlinear analysis, including a static pushover analysis, was implemented on a two-dimensional model of the structural frame. From this analysis the failure mechanisms of the structure were revealed with relation to an allowable roof displacement. The structural integrity of the structure was evaluated based on pre-defined performance goals. Finally multiple suggestions were made how the Augusta Airship Hangar might be repaired and strengthened so that this structure will not be destroyed should an earthquake occur.The results of our study show that historic structures, despite their age, can still be strong and ductile. Also there are a multitude of effective preservation and retrofit techniques that can be used to strengthen these historic structures, should an earthquake occur. Through this study, the Augusta Airship Hangar has proven to be not only a historic symbol for Sicily but also can be used as an example for the rehabilitation of other historic structures. The techniques and processes discussed in this paper can be applied to other historic reinforced concrete structures and can be expanded upon in future investigations.
XU,J.; COSTANTINO,C.; HOFMAYER,C.; MURPHY,A.; KITADA,Y.
2003-08-17
As part of a verification test program for seismic analysis codes for NPP structures, the Nuclear Power Engineering Corporation (NUPEC) of Japan has conducted a series of field model test programs to ensure the adequacy of methodologies employed for seismic analyses of NPP structures. A collaborative program between the United States and Japan was developed to study seismic issues related to NPP applications. The US Nuclear Regulatory Commission (NRC) and its contractor, Brookhaven National Laboratory (BNL), are participating in this program to apply common analysis procedures to predict both free field and soil-structure interaction (SSI) responses to recorded earthquake events, including embedment and dynamic cross interaction (DCI) effects. This paper describes the BNL effort to predict seismic responses of the large-scale realistic model structures for reactor and turbine buildings at the NUPEC test facility in northern Japan. The NUPEC test program has collected a large amount of recorded earthquake response data (both free-field and in-structure) from these test model structures. The BNL free-field analyses were performed with the CARES program while the SSI analyses were preformed using the SASS12000 computer code. The BNL analysis includes both embedded and excavated conditions, as well as the DCI effect, The BNL analysis results and their comparisons to the NUPEC recorded responses are presented in the paper.
Kukushkin, A B
2005-01-01
The paper briefly reviews (i) the evidences for self-similar structures of a skeletal form (namely, tubules and cartwheels, and their simplest combinations), called the Universal Skeletal Structures (USS), observed in the range 10-5 cm - 1023 cm. in the high-current electric discharges in various fusion devices, severe weather phenomena, and space, (ii) the models for interpreting the phenomenon of skeletal structures, including the hypothesis for a fractal condensed matter (FCM), assembled from nanotubular dust, and (iii) probable role of FCM, which might be responsible for the USS phenomenon, in tornado, ball lightning, and waterspout.
Langmead, Christopher James
for the native structure against alternate backbone structures. In a case study of WW domains, we show models to identify sequences with low internal energies for a prescribed backbone structure 4, 20 the target structure over alternatives. A few algo- rithms have been proposed to address the issue of speci
Phase structure and Higgs boson mass in a Higgs-Yukawa model with a dimension-6 operator
David Y. -J. Chu; Karl Jansen; Bastian Knippschild; C. -J. David Lin; Kei-Ichi Nagai; Attila Nagy
2015-01-01
We investigate the impact of a $\\lambda_6 \\varphi^6$ term included in a chirally invariant lattice Higgs-Yukawa model. Such a term could emerge from BSM physics at some larger energy scale. We map out the phase structure of the Higgs-Yukawa model with positive $\\lambda_6$ and negative quartic self coupling of the scalar fields. To this end, we evaluate the constraint effective potential in lattice perturbation theory and also determine the magnetization of the model via numerical simulations which allow us to reach also non-perturbative values of the couplings. As a result, we find a complex phase structure with first and second order phase transitions identified through the magnetization. Further we analyze the effect of such a $\\varphi^6$ term on the lower Higgs boson mass bound to see, whether the standard model lower mass bound can be altered.
Mai, Trieu; Barrows, Clayton; Lopez, Anthony; Hale, Elaine; Dyson, Mark; Eurek, Kelly
2015-04-23
We examine how model investment decisions change under different model configurations and assumptions related to renewable capacity credit, the inclusion or exclusion of operating reserves, dispatch period sampling, transmission power flow modeling, renewable spur line costs, and the ability of a planning region to import and export power. For all modeled scenarios, we find that under market conditions where new renewable deployment is predominantly driven by renewable portfolio standards, model representations of wind and solar capacity credit and interactions between balancing areas are most influential in avoiding model investments in excess thermal capacity. We also compare computation time between configurations to evaluate tradeoffs between computational burden and model accuracy. From this analysis, we find that certain advanced dispatch representations (e.g., DC optimal power flow) can have dramatic adverse effects on computation time but can be largely inconsequential to model investment outcomes, at least at the renewable penetration levels modeled. Finally, we find that certain underappreciated aspects of new capacity investment decisions and model representations thereof, such as spur lines for new renewable capacity, can influence model outcomes particularly in the renewable technology and location chosen by the model. Though this analysis is not comprehensive and results are specific to the model region, input assumptions, and optimization-modeling framework employed, the findings are intended to provide a guide for model improvement opportunities.
Modeling and fabrication of self-assembling micron-scale rollup structures
Cybulski, James Stanley, 1979-
2004-01-01
Self-assembling micron-scale structures based on standard photolithographic and thin film deposition techniques are investigated. Differences in residual stress between successive thin film layers causes the structures to ...
Mukherjee, Srayanta
2011-12-31
Since its birth, the study of protein structures has made progress with leaps and bounds. However, owing to the expenses and difficulties involved, the number of protein structures has not been able to catch up with the ...
Lu, Xueying
We present the design of a volumetric metamaterial (MTM) structure and its interaction with a relativistic electron beam. This novel structure has promising applications in particle beam diagnostics, acceleration, and ...
Anderson, R W; Pember, R B; Elliot, N S
2000-09-26
A new method for the solution of the unsteady Euler equations has been developed. The method combines staggered grid Lagrangian techniques with structured local adaptive mesh refinement (AMR). This method is a precursor to a more general adaptive arbitrary Lagrangian Eulerian (ALE-AMR) algorithm under development, which will facilitate the solution of problems currently at and beyond the boundary of soluble problems by traditional ALE methods by focusing computational resources where they are required. Many of the core issues involved in the development of the ALE-AMR method hinge upon the integration of AMR with a Lagrange step, which is the focus of the work described here. The novel components of the method are mainly driven by the need to reconcile traditional AMR techniques, which are typically employed on stationary meshes with cell-centered quantities, with the staggered grids and grid motion employed by Lagrangian methods. These new algorithmic components are first developed in one dimension and are then generalized to two dimensions. Solutions of several model problems involving shock hydrodynamics are presented and discussed.
The fine structure of the entanglement entropy in the classical XY model
Li-Ping Yang; Yuzhi Liu; Haiyuan Zou; Z. Y. Xie; Y. Meurice
2015-07-13
We compare two calculations of the particle density in the superfluid phase of the classical XY model with a chemical potential $\\mu$ in 1+1 dimensions.The first relies on exact blocking formulas from the Tensor Renormalization Group (TRG) formulation of the transfer matrix. The second is a worm algorithm. We show that the particle number distributions obtained with the two methods agree well. We use the TRG method to calculate the thermal entropy and the entanglement entropy. We describe the particle density, the two entropies and the topology of the world lines as we increase $\\mu$ to go across the superfluid phase between the first two Mott insulating phases. For a sufficiently large temporal size, this process reveals an interesting fine structure: the average particle number and the winding number of most of the world lines in the Euclidean time direction increase by one unit at a time. At each step, the thermal entropy develops a peak and the entanglement entropy increases until we reach half-filling and then decreases in a way that approximately mirror the ascent. This suggests an approximate fermionic picture.
Phase structure and the gluon propagator of SU(2) gauge-Higgs model in two dimensions
Shinya Gongyo; Daniel Zwanziger
2015-01-26
We study numerically the phase structure and the gluon propagator of the SU(2) gauge-Higgs model in two dimensions. First, we calculate gauge-invariant quantities, in particular the static potential from Wilson Loop, the W propagator, and the plaquette expectation value. Our results suggest that a confinement-like region and a Higgs-like region appear even in two dimensions. In the confinement-like region, the static potential rises linearly, with string breaking at large distances, while in the Higgs-like region, it is of Yukawa type, consistent with a Higgs-type mechanism. The correlation length obtained from the W propagator has a finite maximum between these regions. The plaquette expectation value shows a smooth cross-over consistent with the Fradkin-Shenker-Osterwalder-Seiler theorem. From these results, we suggest that there is no phase transition in two dimensions. We also calculate a gauge-dependent order parameter in Landau gauge. Unlike gauge invariant quantities, the gauge non-invariant order parameter has a line of discontinuity separating these two regions. Finally we calculate the gluon propagtor. We infer from its infrared behavior that the gluon propagator would vanish at zero momentum in the infinite-volume limit, consistent with an analytical study.
Oxygen reduction by lithium on model carbon and oxidized carbon structures
Xu, Ye [ORNL; Shelton Jr, William Allison [ORNL
2011-01-01
Li-air batteries have attracted substantial interest for their high theoretical specific energies, but the oxygen reduction reaction by Li (Li-ORR) that occurs at the carbon cathode remains poorly understood. Periodic density functional theory calculations have been performed to examine the Li-ORR on several model carbon structures, including the graphite(0001) basal plane, the (8,0) single-wall nanotube, the armchair-type edge, and a di-vacancy in the basal plane. The inertness of the basal plane limits the reversible potential of O{sub 2} reduction to 1.1 V, and slightly higher to 1.2 V on the curved nanotube. The armchair edge and di-vacancy are highly reactive and significantly oxidized at ambient conditions to various CO{sub x} groups, which are reduced by Li via redox mechanisms at 1.2-1.4 V. These CO{sub x} groups can also catalyze O{sub 2} reduction at up to 2.3 V (an overpotential of 0.4 V vs. the calculated equilibrium potential for bulk Li{sub 2}O{sub 2} formation) by chelating and stabilizing the LiO{sub 2} intermediate. The Li-ORR on graphitic carbon, if via concerted Li{sup +}/e{sup -} transfer and involving carbon, lithium, and oxygen only, is therefore expected to initiate with the smallest overpotential at under-coordinated carbon centers that are oxidized at ambient conditions.
Kusiak, Andrew
of the wind industry, such as wind turbine predictive control [2,3], wind power grid integration and economic July 2012 Available online Keywords: Time series Forecasting Wind power Wind speed Bayesian structural applications, such as wind turbine predictive control, wind power scheduling. The proposed model is tested
Kerrigan, John, E.
1 Structural Bioinformatics Today you will learn how to use the Sybyl molecular modeling package. Use Compute > Charges > MMFF94... > Change Formal Charges? Click No The atoms should now be labeled with partial atomic charges. To remove these labels, use the button to change the labels. You will see
van Stokkum, Ivo
the ability to convert solar energy into chemical energy (stored in the form of ATP and NADPH), whichThe Flow of Excitation Energy in LHCII Monomers: Implications for the Structural Model of the Major Plant Antenna Claudiu C. Gradinaru,* Sevgi O¨ zdemir,# Demet Gu¨ len,# Ivo H.M. van Stokkum,* Rienk van
Ethanol plant investment in Canada: A structural model1 C.-Y. Cynthia Lin and Fujin Yi
Lin, C.-Y. Cynthia
1 Ethanol plant investment in Canada: A structural model1 C.-Y. Cynthia Lin and Fujin Yi Most of the fuel ethanol plants in Canada were built recently and either use corn or wheat as feedstock. It is important to determine what factors affect decisions about when and where to invest in building new ethanol
Byrd, Jimmy
2010-01-14
The purpose of the study was to examine multilevel regression models in the context of multilevel structural equation modeling (SEM) in terms of accuracy of parameter estimates, standard errors, and fit indices in normal ...
Ilic, Marija
1995-01-01
This paper introduces a systematic, structure-based modeling framework for analysis and control of electric power systems for processes evolving over the mid-term and long-term time horizons. Much simpler models than the ...
Aeroelastic Modeling of Offshore Turbines and Support Structures in Hurricane-Prone Regions (Poster)
Damiani, R.
2014-03-01
US offshore wind turbines (OWTs) will likely have to contend with hurricanes and the associated loading conditions. Current industry standards do not account for these design load cases (DLCs), thus a new approach is required to guarantee that the OWTs achieve an appropriate level of reliability. In this study, a sequentially coupled aero-hydro-servo-elastic modeling technique was used to address two design approaches: 1.) The ABS (American Bureau of Shipping) approach; and 2.) The Hazard Curve or API (American Petroleum Institute) approach. The former employs IEC partial load factors (PSFs) and 100-yr return-period (RP) metocean events. The latter allows setting PSFs and RP to a prescribed level of system reliability. The 500-yr RP robustness check (appearing in [2] and [3] upcoming editions) is a good indicator of the target reliability for L2 structures. CAE tools such as NREL's FAST and Bentley's' SACS (offshore analysis and design software) can be efficiently coupled to simulate system loads under hurricane DLCs. For this task, we augmented the latest FAST version (v. 8) to include tower aerodynamic drag that cannot be ignored in hurricane DLCs. In this project, a 6 MW turbine was simulated on a typical 4-legged jacket for a mid-Atlantic site. FAST-calculated tower base loads were fed to SACS at the interface level (transition piece); SACS added hydrodynamic and wind loads on the exposed substructure, and calculated mudline overturning moments, and member and joint utilization. Results show that CAE tools can be effectively used to compare design approaches for the design of OWTs in hurricane regions and to achieve a well-balanced design, where reliability levels and costs are optimized.
Structural Model of the Basement in the Central Savannah River Area, South Carolina and Georgia
Stephenson, D. [Westinghouse Savannah River Company, AIKEN, SC (United States); Stieve, A.
1992-03-01
Interpretation of several generations of seismic reflection data and potential field data suggests the presence of several crustal blocks within the basement beneath the Coastal Plain in the Central Savannah River Area (CSRA). The seismic reflection and refraction data include a grid of profiles that capture shallow and deep reflection events and traverse the Savannah River Site and vicinity. Potential field data includes aeromagnetic, ground magnetic surveys, reconnaissance and detailed gravity surveys. Subsurface data from recovered core are used to constrain the model.Interpretation of these data characteristically indicate a southeast dipping basement surface with some minor highs and lows suggesting an erosional pre-Cretaceous unconformity. This surface is interrupted by several basement faults, most of which offset only early Cretaceous sedimentary horizons overlying the erosional surface. The oldest fault is perhaps late Paleozoic because it is truncated at the basement/Coastal Plain interface. This fault is related in timing and mechanism to the underlying Augusta fault. The youngest faults deform Coastal Plain sediments of at least Priabonian age (40-36.6 Ma). One of these young faults is the Pen Branch faults, identified as the southeast dipping master fault for the Triassic Dunbarton basin. All the Cenozoic faults are probably related in time and mechanism to the nearby, well studied Belair fault.The study area thus contains a set of structures evolved from the Alleghanian orogeny through Mesozoic extension to Cenozoic readjustment of the crust. There is a metamorphosed crystalline terrane with several reflector/fault packages, a reactivated Triassic basin, a mafic terrane separating the Dunbarton basin from the large South Georgia basin to the southeast, and an overprint of reverse faults, some reactivated, and some newly formed.
Reinhold H. Dauskardt
2005-08-30
Final technical report detailing unique experimental and multi-scale computational modeling capabilities developed to study fracture and subcritical cracking in thin-film structures. Our program to date at Stanford has studied the mechanisms of fracture and fatigue crack-growth in structural ceramics at high temperature, bulk and thin-film glasses in selected moist environments where we demonstrated the presence of a true mechanical fatigue effect in some glass compositions. We also reported on the effects of complex environments and fatigue loading on subcritical cracking that effects the reliability of MEMS and other micro-devices using novel micro-machined silicon specimens and nanomaterial layers.
From screen to structure with a harvestable microfluidic device
Stojanoff V.; Jakonic, J.; Oren, D.A.; Nagarajan, V.; Navarro Poulsen, J.C.; Adams-Cioaba, M.A.; Bergfors, T. and Sommer, M.O.A.
2011-06-21
Advances in automation have facilitated the widespread adoption of high-throughput vapor-diffusion methods for initial crystallization screening. However, for many proteins, screening thousands of crystallization conditions fails to yield crystals of sufficient quality for structural characterization. Here, the rates of crystal identification for thaumatin, catalase and myoglobin using microfluidic Crystal Former devices and sitting-drop vapour-diffusion plates are compared. It is shown that the Crystal Former results in a greater number of identified initial crystallization conditions compared with vapor diffusion. Furthermore, crystals of thaumatin and lysozyme obtained in the Crystal Former were used directly for structure determination both in situ and upon harvesting and cryocooling. On the basis of these results, a crystallization strategy is proposed that uses multiple methods with distinct kinetic trajectories through the protein phase diagram to increase the output of crystallization pipelines.
Karplus, Kevin
-state classification of secondary structure that places a residue in one of three categories: helix, sheet, or coil. This is a broad classification, as it provides little information about the coil category that accounts for 45.2,24,25 One group used only secondary structure information to build a template library of HMMs
COMMENTS ON STRUCTURAL CONDITION ANALYSIS BASED ON STRAIN MEASUREMENTS ON TRIPOD MODEL
Boyer, Edmond
strain can be valuable indicator of such changes. KEYWORDS : offshore support structure, wind turbine depth of 50 m. Bigger size wind turbines are now designed in order to produce more electrical power than. On the other hand the problems connected with structural health monitoring (SHM) of offshore wind turbines have
Jing-Fei Zhang; Ming-Ming Zhao; Yun-He Li; Xin Zhang
2015-03-27
The model of holographic dark energy (HDE) with massive neutrinos and/or dark radiation is investigated in detail. The background and perturbation evolutions in the HDE model are calculated. We employ the PPF approach to overcome the gravity instability difficulty (perturbation divergence of dark energy) led by the equation-of-state parameter $w$ evolving across the phantom divide $w=-1$ in the HDE model with $cpower spectrum and the matter power spectrum in the HDE scenario are discussed. Furthermore, we constrain the models of HDE with massive neutrinos and/or dark radiation by using the latest measurements of expansion history and growth of structure, including the Planck CMB temperature data, the baryon acoustic oscillation data, the JLA supernova data, the Hubble constant direct measurement, the cosmic shear data of weak lensing, the Planck CMB lensing data, and the redshift space distortions data. We find that $\\sum m_\
Zhang, Jing-Fei; Li, Yun-He; Zhang, Xin
2015-01-01
The model of holographic dark energy (HDE) with massive neutrinos and/or dark radiation is investigated in detail. The background and perturbation evolutions in the HDE model are calculated. We employ the PPF approach to overcome the gravity instability difficulty (perturbation divergence of dark energy) led by the equation-of-state parameter $w$ evolving across the phantom divide $w=-1$ in the HDE model with $cpower spectrum and the matter power spectrum in the HDE scenario are discussed. Furthermore, we constrain the models of HDE with massive neutrinos and/or dark radiation by using the latest measurements of expansion history and growth of structure, including the Planck CMB temperature data, the baryon acoustic oscillation data, the JLA supernova data, the Hubble constant direct measurement, the cosmic shear...
R. Gutierrez; R. Caetano; P. B. Woiczikowski; T. Kubar; M. Elstner; G. Cuniberti
2009-10-02
Charge transport through a short DNA oligomer (Dickerson dodecamer) in presence of structural fluctuations is investigated using a hybrid computational methodology based on a combination of quantum mechanical electronic structure calculations and classical molecular dynamics simulations with a model Hamiltonian approach. Based on a fragment orbital description, the DNA electronic structure can be coarse-grained in a very efficient way. The influence of dynamical fluctuations arising either from the solvent fluctuations or from base-pair vibrational modes can be taken into account in a straightforward way through time series of the effective DNA electronic parameters, evaluated at snapshots along the MD trajectory. We show that charge transport can be promoted through the coupling to solvent fluctuations, which gate the onsite energies along the DNA wire.
An improved structural mechanics model for the FRAPCON nuclear fuel performance code
Mieloszyk, Alexander James
2012-01-01
In order to provide improved predictions of Pellet Cladding Mechanical Interaction (PCMI) for the FRAPCON nuclear fuel performance code, a new model, the FRAPCON Radial-Axial Soft Pellet (FRASP) model, was developed. This ...
Li, Ke
2012-02-14
functions or any function of independent variables within the suggested frameworks. Also shown was that adopting suggested models could greatly increase predictive accuracy through simulations. In the second essay we generalized the suggested models...
Childhood sexual abuse, body image, and disordered eating: a structural modeling analysis
Williams, Tara Lyn
1998-01-01
Based on previous literature, a model of the Micrographics. relationships between child sexual abuse (CSA), body image, dieting, bulimia, and ESD was proposed. The model specified that (a) child sexual abuse directly affects body image, (b) body...
Structure of the Kinase Domain of CaMKII and Modeling the Holoenzyme
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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effect PhotovoltaicsStructure and Receptorsurvivor 8 Structure of theStructure
deLorimier, Elaine; Coonrod, Leslie A.; Copperman, Jeremy; Taber, Alex; Reister, Emily E.; Sharma, Kush; Todd, Peter K.; Guenza, Marina G.; Berglund, J. Andrew
2014-10-10
In this study, CUG repeat expansions in the 3' UTR of dystrophia myotonica protein kinase (DMPK) cause myotonic dystrophy type 1 (DM1). As RNA, these repeats elicit toxicity by sequestering splicing proteins, such as MBNL1, into protein–RNA aggregates. Structural studies demonstrate that CUG repeats can form A-form helices, suggesting that repeat secondary structure could be important in pathogenicity. To evaluate this hypothesis, we utilized structure-stabilizing RNA modifications pseudouridine (?) and 2'-O-methylation to determine if stabilization of CUG helical conformations affected toxicity. CUG repeats modified with ? or 2'-O-methyl groups exhibited enhanced structural stability and reduced affinity for MBNL1. Molecular dynamics and X-ray crystallography suggest a potential water-bridging mechanism for ?-mediated CUG repeat stabilization. ? modification of CUG repeats rescued mis-splicing in a DM1 cell model and prevented CUG repeat toxicity in zebrafish embryos. This study indicates that the structure of toxic RNAs has a significant role in controlling the onset of neuromuscular diseases.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
deLorimier, Elaine; Coonrod, Leslie A.; Copperman, Jeremy; Taber, Alex; Reister, Emily E.; Sharma, Kush; Todd, Peter K.; Guenza, Marina G.; Berglund, J. Andrew
2014-10-10
In this study, CUG repeat expansions in the 3' UTR of dystrophia myotonica protein kinase (DMPK) cause myotonic dystrophy type 1 (DM1). As RNA, these repeats elicit toxicity by sequestering splicing proteins, such as MBNL1, into protein–RNA aggregates. Structural studies demonstrate that CUG repeats can form A-form helices, suggesting that repeat secondary structure could be important in pathogenicity. To evaluate this hypothesis, we utilized structure-stabilizing RNA modifications pseudouridine (?) and 2'-O-methylation to determine if stabilization of CUG helical conformations affected toxicity. CUG repeats modified with ? or 2'-O-methyl groups exhibited enhanced structural stability and reduced affinity for MBNL1. Molecular dynamicsmore »and X-ray crystallography suggest a potential water-bridging mechanism for ?-mediated CUG repeat stabilization. ? modification of CUG repeats rescued mis-splicing in a DM1 cell model and prevented CUG repeat toxicity in zebrafish embryos. This study indicates that the structure of toxic RNAs has a significant role in controlling the onset of neuromuscular diseases.« less
Thomas Buchert; Alvaro Dominguez
1998-05-27
The generally held view that a model of large-scale structure, formed by collisionless matter in the Universe, can be based on the matter model ``dust'' fails in the presence of multi-stream flow, i.e., velocity dispersion. We argue that models for large-scale structure should rather be constructed for a flow which describes the average motion of a multi-stream system. We present a clearcut reasoning how to approach the problem and derive an evolution equation for the mean peculiar-velocity relative to background solutions of Friedmann-Lema\\^\\i tre type. We consider restrictions of the nonlinear problem and show that the effect of velocity dispersion gives rise to an effective viscosity of non-dissipative gravitational origin. We discuss subcases which arise naturally from this approach: the ``sticky particle model'' and the ``adhesion approximation''. We also construct a novel approximation that features adhesive action in the multi-stream regime while conserving momentum, which was considered a drawback of the standard approximation based on Burger's equation. We finally argue that the assumptions made to obtain these models should be relaxed and we discuss how this can be achieved.
Discovering Block-Structured Process Models From Event Logs Containing Infrequent Behaviour
van der Aalst, Wil
behaviour, process discovery aims to find a process model that `best' describes this behaviour. A large and bottlenecks [17,15,4]. e d a b c f Figure 1: Unsound process model. The challenge in process discovery infrequent behaviour and challenge discovery algorithms, as a process model scoring well on all quality
Chrissanthopoulos, A.; Jovari, P.; Kaban, I.; Gruner, S.; Kavetskyy, T.; Borc, J.; Wang, W.; Ren, J.; Chen, G.; Yannopoulos, S.N.
2012-08-15
We report an investigation of the structure and vibrational modes of Ge-In-S-AgI bulk glasses using X-ray diffraction, EXAFS spectroscopy, Reverse Monte-Carlo (RMC) modelling, Raman spectroscopy, and density functional theoretical (DFT) calculations. The combination of these techniques made it possible to elucidate the short- and medium-range structural order of these glasses. Data interpretation revealed that the AgI-free glass structure is composed of a network where GeS{sub 4/2} tetrahedra are linked with trigonal InS{sub 3/2} units; S{sub 3/2}Ge-GeS{sub 3/2} ethane-like species linked with InS{sub 4/2}{sup -} tetrahedra form sub-structures which are dispersed in the network structure. The addition of AgI into the Ge-In-S glassy matrix causes appreciable structural changes, enriching the Indium species with Iodine terminal atoms. The existence of trigonal species InS{sub 2/2}I and tetrahedral units InS{sub 3/2}I{sup -} and InS{sub 2/2}I{sub 2}{sup -} is compatible with the EXAFS and RMC analysis. Their vibrational properties (harmonic frequencies and Raman activities) calculated by DFT are in very good agreement with the experimental values determined by Raman spectroscopy. - Graphical abstract: Experiment (XRD, EXAFS, RMC, Raman scattering) and density functional calculations are employed to study the structure of AgI-doped Ge-In-S glasses. The role of mixed structural units as illustrated in the figure is elucidated. Highlights: Black-Right-Pointing-Pointer Doping Ge-In-S glasses with AgI causes significant changes in glass structure. Black-Right-Pointing-Pointer Experiment and DFT are combined to elucidate short- and medium-range structural order. Black-Right-Pointing-Pointer Indium atoms form both (InS{sub 4/2}){sup -} tetrahedra and InS{sub 3/2} planar triangles. Black-Right-Pointing-Pointer (InS{sub 4/2}){sup -} tetrahedra bond to (S{sub 3/2}Ge-GeS{sub 3/2}){sup 2+} ethane-like units forming neutral sub-structures. Black-Right-Pointing-Pointer Mixed chalcohalide species (InS{sub 3/2}I){sup -} offer vulnerable sites for the uptake of Ag{sup +}.
Paris-Sud XI, UniversitÃ© de
Monitoring and inspection of nuclear reactor are stringent requirements from operator and safety authorities reactors, which consists in locating various reactor structures using an ultrasonic inspection performed theory of diffraction (GTD) and the Kirchhoff approximation (KA). These two approaches appear
A Structure-Controlled Model For Hot Spring Exploration In Taiwan...
give a critical tool for observing the landscape to find out mega-scaled geological structures, which may not be able to be found by conventional approaches. The occurrences of...
Evaluation of the Structure of Levee Transitions on Wave Runup and Overtopping by Physical Modeling
Oaks, Drake Benjamin
2011-08-08
Coastal regions are continually plagued by high water levels induced by river flooding or hurricane induced storm surges. As with any protective structure, it is essential to understand potential problematic regions which ...
Menke, Matthew Ewald, 1978-
2009-01-01
Modem techniques in biology have produced sequence data for huge quantities of proteins, and 3-D structural information for a much smaller number of proteins. We introduce several algorithms that make use of the limited ...
Rapid Loss Modeling of Death and Downtime Caused By Earthquake Induced Damage to Structures
Ghorawat, Sandeep
2012-07-16
, a similar quantitative risk assessment technique is used to examine the indirect loss associated with death and downtime. The four-step approach is subdivided into four distinct tasks: (a) Hazard analysis, (b) Structural analysis, (c) Loss analysis...
Joshi, Praveen Sudhakar
1999-01-01
Predictive Variable Structure and Fuzzy Logic based controllers for the same benchmark problem. Evaluation criteria consist of closed-loop system performance, activity level of the VFC nozzles, ease of controller synthesis, time required to synthesize...
Model-based design of an ultra high performance concrete support structure for a wind turbine
Wang, Zheng, M. Eng. Massachusetts Institute of Technology
2007-01-01
A support tower is the main structure which would support rotor, power transmission and control systems, and elevates the rotating blades above the earth boundary layer. A successful design should ensure safe, efficient ...
2013-01-01
Cite this article as: Hacker et al. : Urban slum structure:Place 2009, 15:107–116. Hacker et al. International JournalHacker et al. International Journal of Health Geographics
Structure-based model for light-harvesting properties of nucleic acid nanostructures
Pan, Keyao
Programmed self-assembly of DNA enables the rational design of megadalton-scale macromolecular assemblies with sub-nanometer scale precision. These assemblies can be programmed to serve as structural scaffolds for secondary ...
Soil Liquefaction–Induced Uplift of Underground Structures: Physical and Numerical Modeling
Chian, Siau Chen; Tokimatsu, Kohji; M.ASCE; Madabhushi, Santana Phani Gopal
2014-07-11
in the liquefiable soil deposit. These consistencies with field observations clearly demonstrate and pave the prospects of applying numerical and/or experimental analyses for geotechnical problems associated with the floatation of underground structures...
A model of the subsurface structure at the Rye Patch geothermal...
structure at the Rye Patch geothermal reservoir based on surface-to-borehole seismic data Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal...
Lo, Cynthia
2005-01-01
Zeolites are crystalline, porous aluminosilicates; while a pure silicate structure is charge-neutral, the substitution of A1³? for Si?? creates in the framework a negative charge, which can be compensated by a proton that ...
A Model of Electrodiffusion and Osmotic Water Flow and its Energetic Structure
Mori, Yoichiro; Eisenberg, Robert S
2011-01-01
We introduce a model for ionic electrodiffusion and osmotic water flow through cells and tissues. The model consists of a system of partial differential equations for ionic concentration and fluid flow with interface conditions at deforming membrane boundaries. The model satisfies a natural energy equality, in which the sum of the entropic, elastic and electrostatic free energies are dissipated through viscous, electrodiffusive and osmotic flows. We discuss limiting models when certain dimensionless parameters are small. Finally, we develop a numerical scheme for the one-dimensional case and present some simple applications of our model to cell volume control.
A Model of Electrodiffusion and Osmotic Water Flow and its Energetic Structure
Yoichiro Mori; Chun Liu; Robert S. Eisenberg
2011-01-27
We introduce a model for ionic electrodiffusion and osmotic water flow through cells and tissues. The model consists of a system of partial differential equations for ionic concentration and fluid flow with interface conditions at deforming membrane boundaries. The model satisfies a natural energy equality, in which the sum of the entropic, elastic and electrostatic free energies are dissipated through viscous, electrodiffusive and osmotic flows. We discuss limiting models when certain dimensionless parameters are small. Finally, we develop a numerical scheme for the one-dimensional case and present some simple applications of our model to cell volume control.
Restricted N-glycan Conformational Space in the PDB and Its Implication in Glycan Structure Modeling
Jo, Sunhwan; Lee, Hui Sun; Skolnick, Jeffrey; Im, Wonpil
2013-03-14
including their orientations with respect to the protein is discussed separately below. Figure 2 shows the RMSD distributions of the N-glycan structure pairs in the PDB and random conformation pool. Note that the RMSD is only measured between glycan... background glycan structures (see Methods for details). By deriving the statistical significance using the random background having the identical N-glycan sequence, the length dependence is effectively removed. The generalized extreme value distribution (Eq...
STRUCTURAL VALIDATION OF SYSTEM DYNAMICS AND AGENT-BASED SIMULATION MODELS
Tesfatsion, Leigh
, population dynamics, energy systems, and urban planning. The usefulness of these models is predicated including global warming, population dynamics, energy systems, and urban planning simply defy a face
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Rafique, R.; Xia, J.; Hararuk, O.; Luo, Y.
2014-06-27
Modeled carbon (C) storage capacity is largely determined by the C residence time and net primary productivity (NPP). Extensive research has been done on NPP dynamics but the residence time and their relationships with C storage are much less studied. In this study, we implemented a traceability analysis to understand the modeled C storage and residence time in three land surface models: CSIRO's Atmosphere Biosphere Land Exchange (CABLE) with 9 C pools, Community Land Model (version 3.5) combined with Carnegie-Ames-Stanford Approach (CLM3.5-CASA) with 12 C pools and Community Land Model (version 4) (CLM4) with 26 C pools. The globally averagedmore »C storage and residence time was computed at both individual pool and total ecosystem levels. The spatial distribution of total ecosystem C storage and residence time differ greatly among the three models. The CABLE model showed a closer agreement with measured C storage and residence time in plant and soil pools than CLM3.5-CASA and CLM4. However, CLM3.5-CASA and CLM4 were close to each other in modeled C storage but not with measured data. CABLE stores more C in root whereas CLM3.5-CASA and CLM4 store more C in woody pools, partly due to differential NPP allocation in respective pools. The C residence time in individual C pools is greatly different among models, largely because of different transfer coefficient values among pools. CABLE had higher bulk residence time for soil C pools than the other two models. Overall, the traceability analysis used in this study can help fully characterizes the behavior of complex land models.« less
Structural-chemical modeling of transition of coals to the plastic state
A.M. Gyul'maliev; S.G. Gagarin [FGUP Institute for Fossil Fuels, Moscow (Russian Federation)
2007-02-15
The structural-chemical simulation of the formation of plastic state during the thermal treatment (pyrolysis, coking) of coals is based on allowance for intermolecular interactions in the organic matter. The feasibility of transition of coals to the plastic state is determined by the ratio between the onset plastic state (softening) and runaway degradation temperatures, values that depend on the petrographic composition and the degree of metamorphism of coals and the distribution of structural and chemical characteristics of organic matter. 33 refs., 8 figs., 2 tabs.
Structure of the Kinase Domain of CaMKII and Modeling the Holoenzyme
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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effect PhotovoltaicsStructure and Receptorsurvivor 8 Structure of the
Giardina, Giorgia; DeJong, Matthew J.; Mair, Robert J.
2015-07-30
historische Geba¨ude am Beispiel einer neuen U-Bahnlinie in Rom, Geomechanics and Tunnelling 5 (3) (2012) 275–299. [36] G. Giardina, M. A. N. Hendriks, J. G. Rots, Sensitivity study on tunnelling induced damage to a masonry fac¸ade, Engineering Structures 89...
Steady-state chemical process models. A structural point of view
Neumaier, Arnold
of mixing . . . . . . . . . . . . . . . . . . . . . . . . 13 6.3 Heat exchanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 Process streams 5 3 Sources and sinks 5 4 Atomic units 6 4.1 Structural types of the atomic units . . . . . . . . . . . . . . . . 6 5 Equations 7 5.1 Type of equations
proteinsSTRUCTURE O FUNCTION O BIOINFORMATICS Graphical models of proteinprotein
Ramakrishnan, Naren
in a protein family provide evidence for con- straints on choices of amino acids. Some residues may be strictly con- served, allowing only a single amino acid type in order to preserve proper structure and function coupling from correlation--if a pair of (cross-family) residues has correlated amino acid types
Managerial Coaching Behavior and Employee Outcomes: A Structural Equation Modeling Analysis
Kim, Sewon
2012-10-19
, and organization support, were used to frame the hypothesized conceptual model of managerial coaching outcomes for the current study. The systematic review of relevant literature identified satisfaction with work, role ambiguity, satisfaction with manager, career...
Lazaridis, Themis
on statistical effective energy functions. Although the theoretical foundation of such functions is not clear physical effective energy function SEEF statistical effective energy function Introduction Approaches augmented by implicit solvation models, provide physical effective energy functions that are beginning
Broader source: Energy.gov [DOE]
Presentation given by General Motors at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about validation of material models...
A unifying model for the structure of animal groups on the move
Cristiani, Emiliano
2009-01-01
In this paper we present an agent-based model for the simulation of animal groups on the move in two and three dimensions. The model takes into account only two forces: a long-range cohesion and a short-range repulsion. We also consider the visual field of the animals and the different zones where cohesion and repulsion are active. Interactions between animals are both metric and topological. Unlike most of the existing models, we do not take into account the alignment of the velocities. The main result is that, despite the simplicity of the model, we can obtain almost all known patterns commonly seen in nature for animal groups (globular, extended and front clusters, columns, Vees, Jays, echelons) without adding extra animal-specific features, disclosing the basic causes of pattern formation.
Structure of finite-RSB asymptotic Gibbs measures in the diluted spin glass models
Dmitry Panchenko
2015-02-25
We suggest a possible approach to proving the M\\'ezard-Parisi formula for the free energy in the diluted spin glass models, such as diluted K-spin or random K-sat model at any positive temperature. In the main contribution of the paper, we show that a certain small modification of the Hamiltonian in any of these models forces all finite-RSB asymptotic Gibbs measures in the sense of the overlaps to satisfy the M\\'ezard-Parisi ansatz for the distribution of spins. Unfortunately, what is still missing is a description of the general full-RSB asymptotic Gibbs measures. If one could show that the general case can be approximated by finite-RSB case in the right sense then one could a posteriori remove the small modification of the Hamiltonian to recover the M\\'ezard-Parisi formula for the original model.
Echols, Jana Elizabeth
1995-01-01
In vitro cell model systems derived from rat granuloma cells were developed for the study of multistep ovarian carcinogenesis. Spontaneously immortalized rat granuloma cells (SIGC) were transfected with either the pSV3neo plasmid which contains...
Towards a Formal Semantics for a Structurally Dynamic Noncausal Modelling Language
Nilsson, Henrik
modelling approach, promoting the reuse of components. Modelica is a prime example of this class of lan, many of these languages are referred to as object-oriented mod- elling languages. Modelica [23] is one
RELAP5/MOD3 code manual: Code structure, system models, and solution methods. Volume 1
1995-08-01
The RELAP5 code has been developed for best estimate transient simulation of light water reactor coolant systems during postulated accidents. The code models the coupled behavior of the reactor coolant system and the core for loss-of-coolant accidents, and operational transients, such as anticipated transient without scram, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling, approach is used that permits simulating a variety of thermal hydraulic systems. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater systems. RELAP5/MOD3 code documentation is divided into seven volumes: Volume I provides modeling theory and associated numerical schemes.
A Structurally Based Investigation of Abdominal Aortic Aneurysms in Mouse Models
Collins, Melissa
2012-02-14
parameters of the two vessels that experience AAAs in different models, but also the effects of three major components of AAA formation. Biaxial mechanical tests were performed using a modified computer- controlled device. We examined the solid mechanics...
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Rutqvist, Jonny; Cappa, Frederic; Rinaldi, Antonio P.; Godano, Maxime
2014-12-31
We summarize recent modeling studies of injection-induced fault reactivation, seismicity, and its potential impact on surface structures and nuisance to the local human population. We used coupled multiphase fluid flow and geomechanical numerical modeling, dynamic wave propagation modeling, seismology theories, and empirical vibration criteria from mining and construction industries. We first simulated injection-induced fault reactivation, including dynamic fault slip, seismic source, wave propagation, and ground vibrations. From co-seismic average shear displacement and rupture area, we determined the moment magnitude to about Mw = 3 for an injection-induced fault reactivation at a depth of about 1000 m. We then analyzed themore »ground vibration results in terms of peak ground acceleration (PGA), peak ground velocity (PGV), and frequency content, with comparison to the U.S. Bureau of Mines’ vibration criteria for cosmetic damage to buildings, as well as human-perception vibration limits. For the considered synthetic Mw = 3 event, our analysis showed that the short duration, high frequency ground motion may not cause any significant damage to surface structures, and would not cause, in this particular case, upward CO2 leakage, but would certainly be felt by the local population.« less
Rutqvist, Jonny [Lawrence Berkeley National Lab., CA (United States); Cappa, Frederic [Lawrence Berkeley National Lab., CA (United States); Rinaldi, Antonio P. [Lawrence Berkeley National Lab., CA (United States); Godano, Maxime [Univ. of Nice Sophia-Antipolis (France)
2014-12-31
We summarize recent modeling studies of injection-induced fault reactivation, seismicity, and its potential impact on surface structures and nuisance to the local human population. We used coupled multiphase fluid flow and geomechanical numerical modeling, dynamic wave propagation modeling, seismology theories, and empirical vibration criteria from mining and construction industries. We first simulated injection-induced fault reactivation, including dynamic fault slip, seismic source, wave propagation, and ground vibrations. From co-seismic average shear displacement and rupture area, we determined the moment magnitude to about M_{w} = 3 for an injection-induced fault reactivation at a depth of about 1000 m. We then analyzed the ground vibration results in terms of peak ground acceleration (PGA), peak ground velocity (PGV), and frequency content, with comparison to the U.S. Bureau of Mines’ vibration criteria for cosmetic damage to buildings, as well as human-perception vibration limits. For the considered synthetic M_{w} = 3 event, our analysis showed that the short duration, high frequency ground motion may not cause any significant damage to surface structures, and would not cause, in this particular case, upward CO_{2} leakage, but would certainly be felt by the local population.
Description and assessment of structural and temperature models in the FRAP-T6 code. [PWR; BWR
Siefken, L.J.
1983-01-01
The FRAP-T6 code was developed at the Idaho National Engineering Laboratory (INEL) for the purpose of calculating the transient performance of light water reactor fuel rods during reactor transients ranging from mild operational transients to severe hypothetical loss-of-coolant accidents. An important application of the FRAP-T6 code is to calculate the structural performance of fuel rod cladding. The capabilities of the FRAP-T6 code are assessed by comparisons of code calculations with the measurements of several hundred in-pile experiments on fuel rods. The results of the assessments show that the code accurately and efficiently models the structural and thermal response of fuel rods.
Protein structure and hydration probed by SANS and osmotic stress
Rau, Dr. Donald [National Institutes of Health
2008-01-01
Interactions governing protein folding, stability, recognition, and activity are mediated by hydration. Here, we use small-angle neutron scattering coupled with osmotic stress to investigate the hydration of two proteins, lysozyme and guanylate kinase (GK), in the presence of solutes. By taking advantage of the neutron contrast variation that occurs upon addition of these solutes, the number of protein-associated (solute-excluded) water molecules can be estimated from changes in both the zero-angle scattering intensity and the radius of gyration. Poly(ethylene glycol) exclusion varies with molecular weight. This sensitivity can be exploited to probe structural features such as the large internal GK cavity. For GK, small-angle neutron scattering is complemented by isothermal titration calorimetry with osmoticstress to also measure hydration changes accompanying ligand binding. These results provide a framework for studying other biomolecular systems and assemblies using neutron scattering together with osmotic stress.
Modeling and Algorithmic Approaches to Constitutively-Complex, Micro-structured Fluids
Forest, Mark Gregory [University of North Carolina at Chapel Hill] [University of North Carolina at Chapel Hill
2014-05-06
The team for this Project made significant progress on modeling and algorithmic approaches to hydrodynamics of fluids with complex microstructure. Our advances are broken down into modeling and algorithmic approaches. In experiments a driven magnetic bead in a complex fluid accelerates out of the Stokes regime and settles into another apparent linear response regime. The modeling explains the take-off as a deformation of entanglements, and the longtime behavior is a nonlinear, far-from-equilibrium property. Furthermore, the model has predictive value, as we can tune microstructural properties relative to the magnetic force applied to the bead to exhibit all possible behaviors. Wave-theoretic probes of complex fluids have been extended in two significant directions, to small volumes and the nonlinear regime. Heterogeneous stress and strain features that lie beyond experimental capability were studied. It was shown that nonlinear penetration of boundary stress in confined viscoelastic fluids is not monotone, indicating the possibility of interlacing layers of linear and nonlinear behavior, and thus layers of variable viscosity. Models, algorithms, and codes were developed and simulations performed leading to phase diagrams of nanorod dispersion hydrodynamics in parallel shear cells and confined cavities representative of film and membrane processing conditions. Hydrodynamic codes for polymeric fluids are extended to include coupling between microscopic and macroscopic models, and to the strongly nonlinear regime.
D. T. Clark; A. S. Siahpush; G. L. Anderson
2004-07-01
This paper describes a materials and computational model based analysis utilized to design an engineered “overpack” container capable of maintaining structural integrity for confinement of transuranic wastes undergoing the cryo-vacuum stress based “Bag-Buster” process and satisfying DOT 7A waste package requirements. The engineered overpack is a key component of the “Ultra-BagBuster” process/system being commercially developed by UltraTech International for potential DOE applications to non-intrusively breach inner confinement layers (poly bags/packaging) within transuranic (TRU) waste drums. This system provides a lower cost/risk approach to mitigate hydrogen gas concentration buildup limitations on transport of high alpha activity organic transuranic wastes. Four evolving overpack design configurations and two materials (low carbon steel and 300 series stainless) were considered and evaluated using non-linear finite element model analyses of structural response. Properties comparisons show that 300-series stainless is required to provide assurance of ductility and structural integrity at both room and cryogenic temperatures. The overpack designs were analyzed for five accidental drop impact orientations onto an unyielding surface (dropped flat on bottom, bottom corner, side, top corner, and top). The first three design configurations failed the bottom and top corner drop orientations (flat bottom, top, and side plates breached or underwent material failure). The fourth design utilized a protruding rim-ring (skirt) below the overpack’s bottom plate and above the overpack’s lid plate to absorb much of the impact energy and maintained structural integrity under all accidental drop loads at both room and cryogenic temperature conditions. Selected drop testing of the final design will be required to confirm design performance.
Varble, Adam; Fridlind, Ann; Zipser, Edward J.; Ackerman, Andrew; Chaboureau, Jean-Pierre; Fan, Jiwen; Hill, Adrian; McFarlane, Sally A.; Pinty, Jean-Pierre; Shipway, Ben
2011-10-04
The Tropical Warm Pool – International Cloud Experiment (TWP-ICE) provided high quality model forcing and observational datasets through which detailed model and observational intercomparisons could be performed. In this first of a two part study, precipitation and cloud structures within nine cloud-resolving model simulations are compared with scanning radar reflectivity and satellite infrared brightness temperature observations during an active monsoon period from 19 to 25 January 2006. Most simulations slightly overestimate volumetric convective rainfall. Overestimation of simulated convective area by 50% or more in several simulations is somewhat offset by underestimation of mean convective rain rates. Stratiform volumetric rainfall is underestimated by 13% to 53% despite overestimation of stratiform area by up to 65% because stratiform rain rates in every simulation are much lower than observed. Although simulations match the peaked convective radar reflectivity distribution at low levels, they do not reproduce the peaked distributions observed above the melting level. Simulated radar reflectivity aloft in convective regions is too high in most simulations. In stratiform regions, there is a large spread in model results with none resembling observed distributions. Above the melting level, observed radar reflectivity decreases more gradually with height than simulated radar reflectivity. A few simulations produce unrealistically uniform and cold 10.8-?m infrared brightness temperatures, but several simulations produce distributions close to observed. Assumed ice particle size distributions appear to play a larger role than ice water contents in producing incorrect simulated radar reflectivity distributions aloft despite substantial differences in mean graupel and snow water contents across models.
Why does the Standard Model fail to explain the elementary particles structure?
Yuri A. Rylov
2008-10-06
It is shown, that our contemporary knowledge of geometry is insufficient, because we know only axiomatizable geometries. With such a knowledge of geometry one cannot investigate properly physics of microcosm and structure of elementary particles. One can obtain only a phenomenological systematics of elementary particles, whose construction does not need a discrimination mechanism. The discrimination mechanism, responsible for discrete characteristics of elementary particles, can be created only on the basis of a granular (discrete and continuous simultaneously) space-time geometry.
A surface structural approach to ion adsorption: The charge distribution (CD) model
Hiemstra, T.; Van Riemsdijk, W.H.
1996-05-10
Cation and anion adsorption at the solid/solution interface of metal hydroxides plays an important role in several fields of chemistry, including colloid and interface chemistry, soil chemistry and geochemistry, aquatic chemistry, environmental chemistry, catalysis, and chemical engineering. An ion adsorption model for metal hydroxides has been developed which deals with the observation that in the case of inner sphere complex formation only part of the surface complex is incorporated into the surface by a ligand exchange reaction while the other part is located in the Stern layer. The charge distribution (CD) concept of Pauling, used previously in the multi site complexation (MUSIC) model approach, is extended to account for adsorbed surface complexes. In the new model, surface complexes are not treated as point charges, but are considered as having a spatial distribution of charge in the interfacial region. The new CD model can describe within a single conceptual framework all important experimental adsorption phenomena, taking into account the chemical composition of the crystal surface. The CD model has been applied to one of the most difficult and challenging ion adsorption phenomena, i.e., PO{sub 4} adsorption on goethite, and successfully describes simultaneously the basic charging behavior of goethite, the concentration, pH, and salt dependency of adsorption, the shifts in the zeta potentials and isoelectric point (IEP), and the OH/P exchange ratio. This is all achieved within the constraint that the experimental surface speciation found from in situ IR spectroscopy is also described satisfactorily.
Arita, Ken-ichiro
2012-01-01
Deformed shell structures in nuclear mean-field potentials are systematically investigated as functions of deformation and surface diffuseness. As the mean field model to investigate nuclear shell structures in wide range of mass numbers, we propose the radial power-low potential model, V \\propto r^\\alpha, which enables us a simple semiclassical analysis by the use of its scaling property. We find remarkable shell structures emerge at certain combinations of deformation and diffuseness parameters, and they are closely related to the periodic orbit bifurcations. In particular, significant roles of the "bridge orbit bifurcations" for normal and superdeformed shell structures are pointed out. It is shown that the prolate-oblate asymmetry in deformed shell structures is clearly understood from the contribution of bridge orbit to the semiclassical level density. The roles of bridge orbit bifurcations to the emergence of superdeformed shell structures are also discussed.
Ken-ichiro Arita
2012-09-10
Deformed shell structures in nuclear mean-field potentials are systematically investigated as functions of deformation and surface diffuseness. As the mean-field model to investigate nuclear shell structures in a wide range of mass numbers, we propose the radial power-law potential model, V \\propto r^\\alpha, which enables a simple semiclassical analysis by the use of its scaling property. We find that remarkable shell structures emerge at certain combinations of deformation and diffuseness parameters, and they are closely related to the periodic-orbit bifurcations. In particular, significant roles of the "bridge orbit bifurcations" for normal and superdeformed shell structures are pointed out. It is shown that the prolate-oblate asymmetry in deformed shell structures is clearly understood from the contribution of the bridge orbit to the semiclassical level density. The roles of bridge orbit bifurcations in the emergence of superdeformed shell structures are also discussed.
Welch, Stephen; Miles, Steward; Kumar, Suresh; Lemaire, Tony; Chan, Alan
A hierarchy of coupling strategies for integrating advanced three-dimensional modelling methodologies for prediction of the thermo-mechanical response of structures in fire has been developed and systematically assessed. ...
Wirth, Brian
2015-04-08
Materials used in extremely hostile environment such as nuclear reactors are subject to a high flux of neutron irradiation, and thus vast concentrations of vacancy and interstitial point defects are produced because of collisions of energetic neutrons with host lattice atoms. The fate of these defects depends on various reaction mechanisms which occur immediately following the displacement cascade evolution and during the longer-time kinetically dominated evolution such as annihilation, recombination, clustering or trapping at sinks of vacancies, interstitials and their clusters. The long-range diffusional transport and evolution of point defects and self-defect clusters drive a microstructural and microchemical evolution that are known to produce degradation of mechanical properties including the creep rate, yield strength, ductility, or fracture toughness, and correspondingly affect material serviceability and lifetimes in nuclear applications. Therefore, a detailed understanding of microstructural evolution in materials at different time and length scales is of significant importance. The primary objective of this work is to utilize a hierarchical computational modeling approach i) to evaluate the potential for nanoscale precipitates to enhance point defect recombination rates and thereby the self-healing ability of advanced structural materials, and ii) to evaluate the stability and irradiation-induced evolution of such nanoscale precipitates resulting from enhanced point defect transport to and annihilation at precipitate interfaces. This project will utilize, and as necessary develop, computational materials modeling techniques within a hierarchical computational modeling approach, principally including molecular dynamics, kinetic Monte Carlo and spatially-dependent cluster dynamics modeling, to particular, the interfacial structure of embedded nanoscale precipitates will be evaluated by electronic- and atomic-scale modeling methods, and the efficiency of the validated interfaces for trapping point defects will next be evaluated by atomic-scale modeling (e.g., determining the sink strength of the precipitates), addressing key questions related to the optimal interface characteristics to attract point defects and enhance their recombination. Kinetic models will also be developed to simulate microstructural evolution of the nanoscale features and irradiation produced defect clusters, and compared with observed microstructural changes.
Spin vortices in the Abelian-Higgs model with cholesteric vacuum structure
Peterson, Adam; Tallarita, Gianni
2015-01-01
We continue the study of $U(1)$ vortices with cholesteric vacuum structure. A new class of solutions is found which represent global vortices of the internal spin field. These spin vortices are characterized by a non-vanishing angular dependence at spatial infinity, or winding. We show that despite the topological $\\mathbb{Z}_2$ behavior of $SO(3)$ windings, the topological charge of the spin vortices is of the $\\mathbb{Z}$ type in the cholesteric. We find these solutions numerically and discuss the properties derived from their low energy effective field theory in $1+1$ dimensions.
Spin vortices in the Abelian-Higgs model with cholesteric vacuum structure
Adam Peterson; Mikhail Shifman; Gianni Tallarita
2015-08-06
We continue the study of $U(1)$ vortices with cholesteric vacuum structure. A new class of solutions is found which represent global vortices of the internal spin field. These spin vortices are characterized by a non-vanishing angular dependence at spatial infinity, or winding. We show that despite the topological $\\mathbb{Z}_2$ behavior of $SO(3)$ windings, the topological charge of the spin vortices is of the $\\mathbb{Z}$ type in the cholesteric. We find these solutions numerically and discuss the properties derived from their low energy effective field theory in $1+1$ dimensions.
Structure of the Kinase Domain of CaMKII and Modeling the Holoenzyme
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Paris-Sud XI, Université de
measurements and finally its instantiation through 3D printing, are presented. Laser scanner acquisition, reconstruction and 3D printing lend well to teaching general concepts in geometric modeling for several reasons. First, starting and ending with real physical 3D objects (the talus and its 3D print) provide
The spin-boson model with a structured environment: A comparison of approaches
F. K. Wilhelm; S. Kleff; J. von Delft
2003-10-10
In the spin-boson model, the properties of the oscillator bath are fully characterized by the spectral density of oscillators $J(\\omega)$. We study the case when this function is of Breit-Wigner shape and has a sharp peak at a frequency $\\Omega$ with width $\\Gamma\\ll\\Omega$. We use a number of approaches such as the weak-coupling Bloch-Redfield equation, the non-interacting blip approximation (NIBA) and the flow-equation renormalization scheme. We show, that if $\\Omega$ is much larger than the qubit energy scales, the dynamics corresponds to an Ohmic spin-boson model with a strongly reduced tunnel splitting. We also show that the direction of the scaling of the tunnel splitting changes sign when the bare splitting crosses $\\Omega$. We find good agreement between our analytical approximations and numerical results. We illuminate how and why different approaches to the model account for these features and discuss the interpretation of this model in the context of an application to quantum computation and read-out.
Modeling electronic structure and transport properties of graphene with resonant scattering centers
, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747AG Groningen hydrogen impurities and vacancies within a framework of noninteracting tight-binding model on a honey- comb lattice. The algorithms are based on the numerical solution of the time-dependent Schrödinger equation
Hierarchical Modelling of Automotive Sensor Front-Ends For Structural Diagnosis of Aging Faults
Wieringa, Roel
functions previously handled purely mechanical. In addition hybrid and pure electrical cars are emerging are hybrid and electrical cars. The automotive semiconductor elec- tronics market amounted to 19.5 billion for the development of dependable analogue/mixed-signal car front-ends, by interfacing aging models between different
Baran, Sándor
Mathematical Geology, Vol. 34, No. 1, January 2002 ( C 2002) On Modelling Discrete Geological there is a large amount of missing observations, which often is the case in geological applications. We make,predictions,MarkovchainMonteCarlo,simulatedannealing,incomplete observations. INTRODUCTION In many geological applications, there is an interest in predicting properties
Geometry and General Relativity in the Groupoid Model with a Finite Structure Group
M. Heller; T. Miller; L. Pysiak; W. Sasin
2015-01-08
In a series of papers we proposed a model unifying general relativity and quantum mechanics. The idea was to deduce both general relativity and quantum mechanics from a noncommutative algebra ${\\cal A}_{\\Gamma}$ defined on a transformation groupoid $\\Gamma$ determined by the action of the Lorentz group on the frame bundle $(E, \\pi_M, M)$ over space-time $M$. In the present work, we construct a simplified version of the gravitational sector of this model in which the Lorentz group is replaced by a finite group $G$ and the frame bundle is trivial $E=M\\times G$. The model is fully computable. We define the Einstein-Hilbert action, with the help of which we derive the generalized vacuum Einstein equations. When the equations are projected to space-time (giving the "general relativistic limit"), the extra terms that appear due to our generalization can be interpreted as "matter terms", as in Kaluza-Klein-type models. To illustrate this effect we further simplify the metric matrix to a block diagonal form, compute for it the generalized Einstein equations and find two of their "Friedmann-like" solutions for the special case when $G =\\mathbb{Z}_2$. One of them gives the flat Minkowski space-time (which, however, is not static), another, a hyperbolic, linearly expanding universe.
Exploration and Modeling of Structural changes in Waste Glass Under Corrosion
Pantano, Carlos; Ryan, Joseph; Strachan, Denis
2013-11-10
Vitrification is currently the world-wide treatment of choice for the disposition of high-level nuclear wastes. In glasses, radionuclides are atomistically bonded into the solid, resulting in a highly durable product, with borosilicate glasses exhibiting particularly excellent durability in water. Considering that waste glass is designed to retain the radionuclides within the waste form for long periods, it is important to understand the long-term stability of these materials when they react in the environment, especially in the presence of water. Based on a number of previous studies, there is general consensus regarding the mechanisms controlling the initial rate of nuclear waste glass dissolution. Agreement regarding the cause of the observed decrease in dissolution rate at extended times, however, has been elusive. Two general models have been proposed to explain this behavior, and it has been concluded that both concepts are valid and must be taken into account when considering the decrease in dissolution rate. Furthermore, other processes such as water diffusion, ion exchange, and precipitation of mineral phases onto the glass surface may occur in parallel with dissolution of the glass and can influence long-term performance. Our proposed research will address these issues through a combination of aqueous-phase dissolution/reaction experiments and probing of the resulting surface layers with state-of-the-art analytical methods. These methods include solid-state nuclear magnetic resonance (SSNMR) and time-of-flight secondary ion mass spectrometry (TOF-SIMS). The resulting datasets will then be coupled with computational chemistry and reaction-rate modeling to address the most persistent uncertainties in the understanding of glass corrosion, which indeed have limited the performance of the best corrosion models to date. With an improved understanding of corrosion mechanisms, models can be developed and improved that, while still conservative, take advantage of the inherent durability of the waste form to enable secure repositories to be engineered with a much higher density of waste disposition. We propose the synthesis, corrosion, and characterization of two sets of glass samples— containing approximately 8 single-component oxides each—as models for corrosion studies of more complicated glass systems (which can contain in excess of 25 single-component ingredients). Powdered samples and millimeter- sized coupons of these simpler glasses will be corroded in solutions that begin at circumneutral pH, but are known to increase in alkalinity as corrosion proceeds and saturation in silica species is approached. Through carefully selected isotopic substitutions with nuclides that are readily detected with SSNMR and TOF-SIMS methods, we will be able to follow the diffusion of atoms into and out of the reacted surface layers of these glasses and provide new data for testing with existing reaction models. The models can then be further extended or updated to take our new data into account, allowing the existing long-term glass corrosion models to more accurately reflect the extraordinary durability of these systems. With improved models, a significant opportunity exists to better utilize the storage volume of any geologic repository.
Ciambur, Bogdan C
2015-01-01
This work introduces a new fitting formalism for isophotes which enables more accurate modelling of galaxies with non-elliptical shapes, such as disk galaxies viewed edge-on or galaxies with X-shaped/peanut bulges. Within this scheme, the angular parameter which defines quasi-elliptical isophotes is transformed from the commonly used, but inappropriate, polar co-ordinate to the `eccentric anomaly'. This provides a superior description of deviations from ellipticity, better capturing the true isophotal shape. Furthermore, this makes it possible to accurately recover both the surface brightness profile, using the correct azimuthally-averaged isophote, and the two-dimensional model of any galaxy: the hitherto ubiquitous, but artificial, cross-like features in residual images are completely removed. The formalism has been implemented into the IRAF tasks $Ellipse$ and $Bmodel$ to create the new tasks `$Isofit$', and `$Cmodel$'. The new tools are demonstrated here with application to five galaxies, chosen to be rep...
Yu, Charley; Kamboj, Sunita; Wang, Cheng; Cheng, Jing-Jy
2015-09-01
This handbook is an update of the 1993 version of the Data Collection Handbook and the Radionuclide Transfer Factors Report to support modeling the impact of radioactive material in soil. Many new parameters have been added to the RESRAD Family of Codes, and new measurement methodologies are available. A detailed review of available parameter databases was conducted in preparation of this new handbook. This handbook is a companion document to the user manuals when using the RESRAD (onsite) and RESRAD-OFFSITE code. It can also be used for RESRAD-BUILD code because some of the building-related parameters are included in this handbook. The RESRAD (onsite) has been developed for implementing U.S. Department of Energy Residual Radioactive Material Guidelines. Hydrogeological, meteorological, geochemical, geometrical (size, area, depth), crops and livestock, human intake, source characteristic, and building characteristic parameters are used in the RESRAD (onsite) code. The RESRAD-OFFSITE code is an extension of the RESRAD (onsite) code and can also model the transport of radionuclides to locations outside the footprint of the primary contamination. This handbook discusses parameter definitions, typical ranges, variations, and measurement methodologies. It also provides references for sources of additional information. Although this handbook was developed primarily to support the application of RESRAD Family of Codes, the discussions and values are valid for use of other pathway analysis models and codes.
Modeling the thermal and structural response of engineered systems to abnormal environments
Skocypec, R.D.; Thomas, R.K.; Moya, J.L.
1993-10-01
Sandia National Laboratories (SNL) is engaged actively in research to improve the ability to accurately predict the response of engineered systems to thermal and structural abnormal environments. Abnormal environments that will be addressed in this paper include: fire, impact, and puncture by probes and fragments, as well as a combination of all of the above. Historically, SNL has demonstrated the survivability of engineered systems to abnormal environments using a balanced approach between numerical simulation and testing. It is necessary to determine the response of engineered systems in two cases: (1) to satisfy regulatory specifications, and (2) to enable quantification of a probabilistic risk assessment (PRA). In a regulatory case, numerical simulation of system response is generally used to guide the system design such that the system will respond satisfactorily to the specified regulatory abnormal environment. Testing is conducted at the regulatory abnormal environment to ensure compliance.
Determinantal structures in the O'Connell-Yor directed random polymer model
Takashi Imamura; Tomohiro Sasamoto
2015-06-18
We study the semi-discrete directed random polymer model introduced by O'Connell and Yor. We obtain a representation for the moment generating function of the polymer partition function in terms of a determinantal measure. This measure is an extension of the probability measure of the eigenvalues for the Gaussian Unitary Ensemble (GUE) in random matrix theory. To establish the relation, we introduce another determinantal measure on larger degrees of freedom and consider its few properties, from which the representation above follows immediately.
Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides
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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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News PublicationsAudits & InspectionsBeryllium and ChronicBestBeyond the Lone-Pair Model
Varble, Adam C.; Fridlind, Ann; Zipser, Ed; Ackerman, Andrew; Chaboureau, Jean-Pierre; Fan, Jiwen; Hill, Adrian; McFarlane, Sally A.; Pinty, Jean-Pierre; Shipway, Ben
2011-06-24
The Tropical Warm Pool - International Cloud Experiment (TWP-ICE) provided high quality model forcing and observational datasets through which detailed model and observational intercomparisons could be performed. In this first of a two part study, precipitation and cloud structures within nine cloud-resolving model simulations are compared with scanning radar reflectivity and satellite infrared brightness temperature observations during an active monsoon period from 19 to 25 January 2006. Most simulations slightly overestimate volumetric convective rainfall. Overestimation of simulated convective area by 50% or more in several simulations is somewhat offset by underestimation of mean convective rain rates. Stratiform volumetric rainfall is underestimated by 13% to 53% despite overestimation of stratiform area by up to 65% because stratiform rain rates in every simulation are much lower than observed. Although simulations match the peaked convective radar reflectivity distribution at low levels, they do not reproduce the peaked distributions observed above the melting level. Simulated radar reflectivity aloft in convective regions is too high in most simulations. 29 In stratiform regions, there is a large spread in model results with none resembling 30 observed distributions. Above the melting level, observed radar reflectivity decreases 31 more gradually with height than simulated radar reflectivity. A few simulations produce 32 unrealistically uniform and cold 10.8-?m infrared brightness temperatures, but several 33 simulations produce distributions close to observed. Assumed ice particle size 34 distributions appear to play a larger role than ice water contents in producing incorrect 35 simulated radar reflectivity distributions aloft despite substantial differences in mean 36 graupel and snow water contents across models. 37
Wiengarten, T.; Kleimann, J.; Fichtner, H.; Kühl, P.; Kopp, A.; Heber, B.; Kissmann, R.
2014-06-10
The transport of energetic particles such as cosmic rays is governed by the properties of the plasma being traversed. While these properties are rather poorly known for galactic and interstellar plasmas due to the lack of in situ measurements, the heliospheric plasma environment has been probed by spacecraft for decades and provides a unique opportunity for testing transport theories. Of particular interest for the three-dimensional (3D) heliospheric transport of energetic particles are structures such as corotating interaction regions, which, due to strongly enhanced magnetic field strengths, turbulence, and associated shocks, can act as diffusion barriers on the one hand, but also as accelerators of low energy CRs on the other hand as well. In a two-fold series of papers, we investigate these effects by modeling inner-heliospheric solar wind conditions with a numerical magnetohydrodynamic (MHD) setup (this paper), which will serve as an input to a transport code employing a stochastic differential equation approach (second paper). In this first paper, we present results from 3D MHD simulations with our code CRONOS: for validation purposes we use analytic boundary conditions and compare with similar work by Pizzo. For a more realistic modeling of solar wind conditions, boundary conditions derived from synoptic magnetograms via the Wang-Sheeley-Arge (WSA) model are utilized, where the potential field modeling is performed with a finite-difference approach in contrast to the traditional spherical harmonics expansion often utilized in the WSA model. Our results are validated by comparing with multi-spacecraft data for ecliptical (STEREO-A/B) and out-of-ecliptic (Ulysses) regions.
Sheffield, University of
THE STRUCTURAL CHEMISTRY OF MOLYBDENUM IN MODEL HIGH LEVEL NUCLEAR WASTE GLASSES, INVESTIGATED of molybdenum in model UK high level nuclear waste glasses was investigated by X-ray Absorption Spectroscopy (XAS). Molybdenum K-edge XAS data were acquired from several inactive simulant high level nuclear waste
Nayakshin, Sergei
2015-01-01
We present improved population synthesis calculations in the context of the Tidal Downsizing (TD) hypothesis for planet formation. Our models provide natural explanations and/or quantitative match to exoplanet observations in the following categories: (i) most abundant planets being super-Earths; (ii) cores more massive than $\\sim 5-15 M_\\oplus$ are enveloped by massive metal-rich atmospheres; (iii) the frequency of occurrence of close-in gas giant planets correlates strongly with metallicity of the host star; (iv) no such correlation is found for sub-Neptune planets; (v) presence of massive cores in giant planets; (vi) the composition of gas giant planets is over-abundant in metals compared to their host stars; (vii) this over-abundance decreases with planet's mass, as observed; (viii) a deep valley in the planet mass function between masses of $\\sim 10-20 M_\\oplus$ and $\\sim 100 M_\\oplus$. We provide a number of observational predictions distinguishing the model from Core Accretion: (a) composition of the m...
STRUCTURAL ENGINEERING, MECHANICS AND MATERIALS
Wang, Yuhang
· Structural Health Monitoring · Structural Reliability Graduate Studies Structural Engineering, Mechanics sensing device for structural health monitoring and control. 3D finite element modeling and simulationSTRUCTURAL ENGINEERING, MECHANICS AND MATERIALS offers graduate instruction and research
Villanueva, Joshua; Huang, Qian; Sirbuly, Donald J.
2014-09-14
Mechanical characterization is important for understanding small-scale systems and developing devices, particularly at the interface of biology, medicine, and nanotechnology. Yet, monitoring sub-surface forces is challenging with current technologies like atomic force microscopes (AFMs) or optical tweezers due to their probe sizes and sophisticated feedback mechanisms. An alternative transducer design relying on the indentation mechanics of a compressible thin polymer would be an ideal system for more compact and versatile probes, facilitating measurements in situ or in vivo. However, application-specific tuning of a polymer's mechanical properties can be burdensome via experimental optimization. Therefore, efficient transducer design requires a fundamental understanding of how synthetic parameters such as the molecular weight and grafting density influence the bulk material properties that determine the force response. In this work, we apply molecular-level polymer scaling laws to a first order elastic foundation model, relating the conformational state of individual polymer chains to the macroscopic compression of thin film systems. A parameter sweep analysis was conducted to observe predicted model trends under various system conditions and to understand how nano-structural elements influence the material stiffness. We validate the model by comparing predicted force profiles to experimental AFM curves for a real polymer system and show that it has reasonable predictive power for initial estimates of the force response, displaying excellent agreement with experimental force curves. We also present an analysis of the force sensitivity of an example transducer system to demonstrate identification of synthetic protocols based on desired mechanical properties. These results highlight the usefulness of this simple model as an aid for the design of a new class of compact and tunable nanomechanical force transducers.
Structural insights into the catalytic mechanism of a family 18 exo-chitinase
van Aalten, Daan
of retaining enzymes such as lysozyme (11) and amylases (12) in that it involves the N-acetyl group of the 1
De novo protein crystal structure determination from X-ray free-electron laser data
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Barends, Thomas, R.M.
Serial femtosecond crystallography (SFX) data of microcrystals of a lysozyme gadolinium derivative. The data was used to demonstrate de-novo phasing by single anomalous dispersion.
De novo protein crystal structure determination from X-ray free-electron laser data
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Barends, Thomas, R.M.
2013-11-25
Serial femtosecond crystallography (SFX) data of microcrystals of a lysozyme gadolinium derivative. The data was used to demonstrate de-novo phasing by single anomalous dispersion.
Keldrauk, Eric Scott
2012-01-01
until structural and nuclear safety inspections could beSeismic analysis of safety-related nuclear structures anddamage to nuclear equipment or safety related components,
Pizio, O., E-mail: pizio@unam.mx [Instituto de Química, Universidad Nacional Autonoma de México, Circuito Exterior, Ciudad Universitaria, 04510 México, D.F. (Mexico); Soko?owski, S., E-mail: stefan.sokolowski@gmail.com [Department for the Modeling of Physico-Chemical Processes, Maria Curie-Sk?odowska University, 20-031 Lublin (Poland); Soko?owska, Z. [Institute of Agrophysics, Polish Academy of Sciences, Do?wiadczalna 4, 20-290 Lublin (Poland)] [Institute of Agrophysics, Polish Academy of Sciences, Do?wiadczalna 4, 20-290 Lublin (Poland)
2014-05-07
We investigate microscopic structure, adsorption, and electric properties of a mixture that consists of amphiphilic molecules and charged hard spheres in contact with uncharged or charged solid surfaces. The amphiphilic molecules are modeled as spheres composed of attractive and repulsive parts. The electrolyte component of the mixture is considered in the framework of the restricted primitive model (RPM). The system is studied using a density functional theory that combines fundamental measure theory for hard sphere mixtures, weighted density approach for inhomogeneous charged hard spheres, and a mean-field approximation to describe anisotropic interactions. Our principal focus is in exploring the effects brought by the presence of ions on the distribution of amphiphilic particles at the wall, as well as the effects of amphiphilic molecules on the electric double layer formed at solid surface. In particular, we have found that under certain thermodynamic conditions a long-range translational and orientational order can develop. The presence of amphiphiles produces changes of the shape of the differential capacitance from symmetric or non-symmetric bell-like to camel-like. Moreover, for some systems the value of the potential of the zero charge is non-zero, in contrast to the RPM at a charged surface.
Grujicic, Mica
-metal sandwich structures containing auxetic honeycomb cores. Consequently, the following three rele- vant topics
Keldrauk, Eric Scott
2012-01-01
seismic effects on nuclear power structures, significantly increasing safety margins, and facilitating equipment qualification.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Terwilliger, Thomas C.; Bricogne, Gerard
2014-09-30
Accurate crystal structures of macromolecules are of high importance in the biological and biomedical fields. Models of crystal structures in the Protein Data Bank (PDB) are in general of very high quality as deposited. However, methods for obtaining the best model of a macromolecular structure from a given set of experimental X-ray data continue to progress at a rapid pace, making it possible to improve most PDB entries after their deposition by re-analyzing the original deposited data with more recent software. This possibility represents a very significant departure from the situation that prevailed when the PDB was created, when itmore »was envisioned as a cumulative repository of static contents. A radical paradigm shift for the PDB is therefore proposed, away from the static archive model towards a much more dynamic body of continuously improving results in symbiosis with continuously improving methods and software. These simultaneous improvements in methods and final results are made possible by the current deposition of processed crystallographic data (structure-factor amplitudes) and will be supported further by the deposition of raw data (diffraction images). It is argued that it is both desirable and feasible to carry out small-scale and large-scale efforts to make this paradigm shift a reality. Small-scale efforts would focus on optimizing structures that are of interest to specific investigators. Large-scale efforts would undertake a systematic re-optimization of all of the structures in the PDB, or alternatively the redetermination of groups of structures that are either related to or focused on specific questions. All of the resulting structures should be made generally available, along with the precursor entries, with various views of the structures being made available depending on the types of questions that users are interested in answering.« less
Machesky, Michael L.; Predota, M.; Wesolowski, David J
2008-11-01
The detailed solvation structure at the (110) surface of rutile ({alpha}-TiO{sub 2}) in contact with bulk liquid water has been obtained primarily from experimentally verified classical molecular dynamics (CMD) simulations of the ab initio-optimized surface in contact with SPC/E water. The results are used to explicitly quantify H-bonding interactions, which are then used within the refined MUSIC model framework to predict surface oxygen protonation constants. Quantum mechanical molecular dynamics (QMD) simulations in the presence of freely dissociable water molecules produced H-bond distributions around deprotonated surface oxygens very similar to those obtained by CMD with nondissociable SPC/E water, thereby confirming that the less computationally intensive CMD simulations provide accurate H-bond information. Utilizing this H-bond information within the refined MUSIC model, along with manually adjusted Ti-O surface bond lengths that are nonetheless within 0.05 {angstrom} of those obtained from static density functional theory (DFT) calculations and measured in X-ray reflectivity experiments (as well as bulk crystal values), give surface protonation constants that result in a calculated zero net proton charge pH value (pHznpc) at 25 C that agrees quantitatively with the experimentally determined value (5.4 {+-} 0.2) for a specific rutile powder dominated by the (110) crystal face. Moreover, the predicted pH{sub znpc} values agree to within 0.1 pH unit with those measured at all temperatures between 10 and 250 C. A slightly smaller manual adjustment of the DFT-derived Ti-O surface bond lengths was sufficient to bring the predicted pH{sub znpc} value of the rutile (110) surface at 25 C into quantitative agreement with the experimental value (4.8 {+-} 0.3) obtained from a polished and annealed rutile (110) single crystal surface in contact with dilute sodium nitrate solutions using second harmonic generation (SHG) intensity measurements as a function of ionic strength. Additionally, the H-bond interactions between protolyzable surface oxygen groups and water were found to be stronger than those between bulk water molecules at all temperatures investigated in our CMD simulations (25, 150 and 250 C). Comparison with the protonation scheme previously determined for the (110) surface of isostructural cassiterite ({alpha}-SnO{sub 2}) reveals that the greater extent of H-bonding on the latter surface, and in particular between water and the terminal hydroxyl group (Sn-OH) results in the predicted protonation constant for that group being lower than for the bridged oxygen (Sn-O-Sn), while the reverse is true for the rutile (110) surface. These results demonstrate the importance of H-bond structure in dictating surface protonation behavior, and that explicit use of this solvation structure within the refined MUSIC model framework results in predicted surface protonation constants that are also consistent with a variety of other experimental and computational data.
Wirosoetisno, Djoko
ships to oil rigs, repair vessels for offshore wind farms, rescue vessels, and coast guard vessels with structures. We aim to progress nonlinear and breaking wave interactions on offshore structures, in particular
Keldrauk, Eric Scott
2012-01-01
the demand on and risk to nuclear power plant structures.of nuclear power structures, the additional risk posed byrisk associated with high-amplitude seismicity near nuclear power
Keldrauk, Eric Scott
2012-01-01
Gas Tanks . . . . 2.5.4 Nuclear Power Facility Structures .iii 3 Nuclear Power Plants 3.1 Nuclear Facility StructuralThe Kashiwazaki-Kariwa Nuclear Power Plant 3.3.1 2004 Ch¯
Anne-Caroline Genix; Mouna TATOU; Ainara Imaz; Jacqueline Forcada; Ralph Schweins; Isabelle Grillo; Julian Oberdisse
2012-02-29
The evolution of the polymer structure during nanocomposite formation and annealing of silica-latex nanocomposites is studied using contrast-variation small angle neutron scattering. The experimental system is made of silica nanoparticles (Rsi \\approx 8 nm) and a mixture of purpose-synthesized hydrogenated and deuterated nanolatex (Rlatex \\approx 12.5 nm). The progressive disappearance of the latex beads by chain interdiffusion and release in the nanocomposites is analyzed quantitatively with a model for the scattered intensity of hairy latex beads and an RPA description of the free chains. In silica-free matrices and nanocomposites of low silica content (7%v), the annealing procedure over weeks at up to Tg + 85 K results in a molecular dispersion of chains, the radius of gyration of which is reported. At higher silica content (20%v), chain interdiffusion seems to be slowed down on time-scales of weeks, reaching a molecular dispersion only at the strongest annealing. Chain radii of gyration are found to be unaffected by the presence of the silica filler.
Boyer, Edmond
field receiving repeated urban waste compost application Vilim Filipovi1,2,3 , Yves Coquet2 , Valérie properties. Tillage practices and compost amendments can modify soil structure and create heterogeneity and compost application on transport processes. A modeling study was performed to evaluate how the presence
Dinner, Aaron
Lattice model for self-assembly with application to the formation of cytoskeletal-like structures for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA Received. By enabling the de novo formation of coexisting morphologies without the computational cost of explicit
de Groot, Bert
coli Henning Stahlberg,*,1 Thomas Braun,*,1 Bert de Groot, Ansgar Philippsen, Mario J. Borgnia,Â§ Peter) and glycerol facilitators (GLPs) (Heymann and En- gel, 1999; Park and Saier, 1996). Their sequences share this central structure (Mitsuoka et al., 1999). The first atomic model of AQP1 reveals the site of water
Paris-Sud XI, Université de
inherent to management accounting innovation and change. Initially, organizational actors can be in three1 Title: The effects of uncertainty, trust, structure and resistance to change in the diffusion of management accounting innovations: an agent based modeling approach. Author 1: Bertrand Masquefa1 , Ph
Lin, C.-Y. Cynthia
1 Investment in Corn-Ethanol Plants in the Midwestern United States: An Analysis Using Reduced-Form and Structural Models1 C.-Y. Cynthia Lin and Karen E. Thome Abstract Ethanol has attracted considerable policy policy and strategic interactions affect decisions about when and where to invest in building new ethanol
Hsu, Hsien-Yuan
2011-02-22
various conditions. Simulation results showed that RMSEA and CFI only reflected within-model fit. In addition, SRMR for within-model (SRMR-W) was more sensitive to within-model misspecifications in factor covariances than pattern coefficients regardless...
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Los Alamos National Laboratory, Mail Stop M888, Los Alamos, NM 87507 (United States); Bricogne, Gerard, E-mail: terwilliger@lanl.gov [Global Phasing Ltd, Sheraton House, Castle Park, Cambridge CB3 0AX (United Kingdom); Los Alamos National Laboratory, Mail Stop M888, Los Alamos, NM 87507 (United States)
2014-10-01
Macromolecular structures deposited in the PDB can and should be continually reinterpreted and improved on the basis of their accompanying experimental X-ray data, exploiting the steady progress in methods and software that the deposition of such data into the PDB on a massive scale has made possible. Accurate crystal structures of macromolecules are of high importance in the biological and biomedical fields. Models of crystal structures in the Protein Data Bank (PDB) are in general of very high quality as deposited. However, methods for obtaining the best model of a macromolecular structure from a given set of experimental X-ray data continue to progress at a rapid pace, making it possible to improve most PDB entries after their deposition by re-analyzing the original deposited data with more recent software. This possibility represents a very significant departure from the situation that prevailed when the PDB was created, when it was envisioned as a cumulative repository of static contents. A radical paradigm shift for the PDB is therefore proposed, away from the static archive model towards a much more dynamic body of continuously improving results in symbiosis with continuously improving methods and software. These simultaneous improvements in methods and final results are made possible by the current deposition of processed crystallographic data (structure-factor amplitudes) and will be supported further by the deposition of raw data (diffraction images). It is argued that it is both desirable and feasible to carry out small-scale and large-scale efforts to make this paradigm shift a reality. Small-scale efforts would focus on optimizing structures that are of interest to specific investigators. Large-scale efforts would undertake a systematic re-optimization of all of the structures in the PDB, or alternatively the redetermination of groups of structures that are either related to or focused on specific questions. All of the resulting structures should be made generally available, along with the precursor entries, with various views of the structures being made available depending on the types of questions that users are interested in answering.
Electronic structure of the SiN{sub x}/TiN interface: A model system for superhard nanocomposites
Patscheider, Joerg; Hellgren, Niklas; Haasch, Richard T.; Petrov, Ivan; Greene, J. E.
2011-03-15
Nanostructured materials such as nanocomposites and nanolaminates--subjects of intense interest in modern materials research--are defined by internal interfaces, the nature of which is generally unknown. Nevertheless, the interfaces often determine the bulk properties. An example of this is superhard nanocomposites with hardness approaching that of diamond. TiN/Si{sub 3}N{sub 4} nanocomposites (TiN nanocrystals encapsulated in a fully percolated SiN{sub x} tissue phase) and nanolaminates, in particular, have attracted much attention as model systems for the synthesis of such superhard materials. Here, we use in situ angle-resolved x-ray photoelectron spectroscopy to probe the electronic structure of Si{sub 3}N{sub 4}/TiN(001), Si/TiN(001), and Ti/TiN(001) bilayer interfaces, in which 4-ML-thick overlayers are grown in an ultrahigh vacuum system by reactive magnetron sputter deposition onto epitaxial TiN layers on MgO(001). The thickness of the Si{sub 3}N{sub 4}, Si, and Ti overlayers is chosen to be thin enough to insure sufficient electron transparency to probe the interfaces, while being close to values reported in typical nanocomposites and nanolaminates. The results show that these overlayer/TiN(001) interfaces have distinctly different bonding characteristics. Si{sub 3}N{sub 4} exhibits interface polarization through the formation of an interlayer, in which the N concentration is enhanced at higher substrate bias values during Si{sub 3}N{sub 4} deposition. The increased number of Ti-N bonds at the interface, together with the resulting polarization, strengthens interfacial bonding. In contrast, overlayers of Si and, even more so, metallic Ti weaken the interface by minimizing the valence band energy difference between the two phases. A model is proposed that provides a semiquantitative explanation of the interfacial bond strength in nitrogen-saturated and nitrogen-deficient Ti-Si-N nanocomposites.
Yim, Solomon C.
-structure interaction and large geometry in the structural restoring force. Complex nonlinear responses observed-scale experiment of a multi-point- moored, submerged sphere subjected to monochromatic waves was conducted at the O approximation of the nonlinear restoring, and hydrodynamic excitation of inertia and drag components. The waves
Vexler, M. I. [Institut fuer Elektronische Bauelemente und Schaltungstechnik, TU Braunschweig, Hans-Sommer-Strasse 66, D-38106 Braunschweig (Germany); A. F. Ioffe Physical-Technical Institute of the Russian Academy of Sciences, 26 Polytechnicheskaya Str., 194021 St.-Petersburg (Russian Federation); Sokolov, N. S.; Suturin, S. M.; Banshchikov, A. G. [A. F. Ioffe Physical-Technical Institute of the Russian Academy of Sciences, 26 Polytechnicheskaya Str., 194021 St.-Petersburg (Russian Federation); Tyaginov, S. E. [A. F. Ioffe Physical-Technical Institute of the Russian Academy of Sciences, 26 Polytechnicheskaya Str., 194021 St.-Petersburg (Russian Federation); Christian-Dopper-Laboratory and Institut fuer Mikroelektronik, TU Wien, Gusshausstrasse 25-29, A-1040 Vienna (Austria); Grasser, T. [Christian-Dopper-Laboratory and Institut fuer Mikroelektronik, TU Wien, Gusshausstrasse 25-29, A-1040 Vienna (Austria)
2009-04-15
Au/CaF{sub 2}/nSi(111) structures with 4-5 monolayers of epitaxial fluoride are fabricated and electrically tested. The leakage current in these structures was substantially smaller than in similar samples reported previously. Simulations adopting a Franz-type dispersion relation with Franz mass of m{sub F}approx1.2m{sub 0} for carriers in the forbidden band of CaF{sub 2} reproduced the measured current-voltage curves quite satisfactorily. Roughly, these curves could also be reproduced using the parabolic dispersion law with the electron mass of m{sub e}=1.0m{sub 0}, which is a material constant rather than a fitting parameter. Experimental facts and their comparison to modeling results allow qualification of the crystalline quality of fabricated structures as sufficient for device applications.
A New, Stochastic, Energy Model of the U.S. is Under Construction: SEDS and Its Industrial Structure
Roop, J. M.
2009-01-01
"A new energy model for the United States is currently being constructed by staff at five National Laboratories for the Office of Energy Efficiency and Renewable Energy at the Department of Energy. This new model, SEDS (Stochastic Energy Deployment...
Keldrauk, Eric Scott
2012-01-01
tsunami and aftershocks), greatly impacted the Fukushima Daiichi and Kashiwazaki-Kariwa nucleartsunami-induced partial meltdown of the Fukushima Daiichi nuclearnear nuclear power structures. In the former case, tsunami
Empirical Modeling of 3D Plasma Pressure and Magnetic Field Structures in the Earth’s Plasma Sheet
Yue, Chao
2015-01-01
The hourly average solar wind velocity prediction based onsolar wind and IMF data and they concluded that their AE model gives a reliable prediction
Li, Libo; Bentler, Peter
2006-01-01
Model Selection. Manuscript. Curran, P. J. , Bollen, K. A. ,316. Bollen, K. A. , & Curran, P. J. (2006). Latent Curveare given by Bollen and Curran (2006), Byrne (2006), Hays,
Li, Libo; Bentler, Peter
2006-01-01
Model Selection. Manuscript. Curran, P. J. , Bollen, K. A. ,316. Bollen, K. A. , & Curran, P. J. (2006). Latent Curveare given by Bollen and Curran (2006), Byrne (2006), Hays,
Libo Li; Peter Bentler
2011-01-01
Model Selection. Manuscript. Curran, P. J. , Bollen, K. A. ,316. Bollen, K. A. , & Curran, P. J. (2006). Latent Curveare given by Bollen and Curran (2006), Byrne (2006), Hays,
Dissecting Lysozyme by Single- Molecule Techniques
Collins, Philip G
2013-01-01
Experiments Determine Protein Folding Transition Path Times.P.G. Theory of protein folding: the energy landscapevarious aspects of protein folding have been examined via
Geoffrey A. Phelps; Leigh Justet; Barry C. Moring, and Carter W. Roberts
2006-03-17
New gravity and magnetic data collected in the vicinity of Massachusetts Mountain and CP basin (Nevada Test Site, NV) provides a more complex view of the structural relationships present in the vicinity of CP basin than previous geologic models, helps define the position and extent of structures in southern Yucca Flat and CP basin, and better constrains the configuration of the basement structure separating CP basin and Frenchman Flat. The density and gravity modeling indicates that CP basin is a shallow, oval-shaped basin which trends north-northeast and contains ~800 m of basin-filling rocks and sediment at its deepest point in the northeast. CP basin is separated from the deeper Frenchman Flat basin by a subsurface ridge that may represent a Tertiary erosion surface at the top of the Paleozoic strata. The magnetic modeling indicates that the Cane Spring fault appears to merge with faults in northwest Massachusetts Mountain, rather than cut through to Yucca Flat basin and that the basin is downed-dropped relative to Massachusetts Mountain. The magnetic modeling indicates volcanic units within Yucca Flat basin are down-dropped on the west and supports the interpretations of Phelps and KcKee (1999). The magnetic data indicate that the only faults that appear to be through-going from Yucca Flat into either Frenchman Flat or CP basin are the faults that bound the CP hogback. In general, the north-trending faults present along the length of Yucca Flat bend, merge, and disappear before reaching CP hogback and Massachusetts Mountain or French Peak.
Zhu, Hong
cases is difficult and expensive, especially for testing software systems whose input is structurally is one of the most difficult and expensive tasks in software testing, especially for software systems programming languages, XML document processor, CAD software, etc. To test such a software system adequately
Ridley, Mora K.; Hiemstra, T; Van Riemsdijk, Willem H.; Machesky, Michael L.
2009-01-01
Acid base reactivity and ion-interaction between mineral surfaces and aqueous solutions is most frequently investigated at the macroscopic scale as a function of pH. Experimental data are then rationalized by a variety of surface complexation models. These models are thermodynamically based which in principle does not require a molecular picture. The models are typically calibrated to relatively simple solid-electrolyte solution pairs and may provide poor descriptions of complex multicomponent mineral aqueous solutions, including those found in natural environments. Surface complexation models may be improved by incorporating molecular-scale surface structural information to constrain the modeling efforts. Here, we apply a concise, molecularly-constrained surface complexation model to a diverse suite of surface titration data for rutile and thereby begin to address the complexity of multi-component systems. Primary surface charging curves in NaCl, KCl, and RbCl electrolyte media were fit simultaneously using a charge distribution (CD) and multisite complexation (MUSIC) model [Hiemstra T. and Van Riemsdijk W. H. (1996) A surface structural approach to ion adsorption: the charge distribution (CD) model. J. Colloid Interf. Sci. 179, 488 508], coupled with a Basic Stern layer description of the electric double layer. In addition, data for the specific interaction of Ca2+ and Sr2+ with rutile, in NaCl and RbCl media, were modeled. In recent developments, spectroscopy, quantum calculations, and molecular simulations have shown that electrolyte and divalent cations are principally adsorbed in various inner-sphere configurations on the rutile 110 surface [Zhang Z., Fenter P., Cheng L., Sturchio N. C., Bedzyk M. J., Pr edota M., Bandura A., Kubicki J., Lvov S. N., Cummings P. T., Chialvo A. A., Ridley M. K., Be ne zeth P., Anovitz L., Palmer D. A., Machesky M. L. and Wesolowski D. J. (2004) Ion adsorption at the rutile water interface: linking molecular and macroscopic properties. Langmuir 20, 4954 4969]. Our CD modeling results are consistent with these adsorbed configurations provided adsorbed cation charge is allowed to be distributed between the surface (0-plane) and Stern plane (1-plane). Additionally, a complete description of our titration data required inclusion of outer-sphere binding, principally for Cl which was common to all solutions, but also for Rb+ and K+. These outer-sphere species were treated as point charges positioned at the Stern layer, and hence determined the Stern layer capacitance value. The modeling results demonstrate that a multi-component suite of experimental data can be successfully rationalized within a CD and MUSIC model using a Stern-based description of the EDL. Furthermore, the fitted CD values of the various inner-sphere complexes of the mono- and divalent ions can be linked to the microscopic structure of the surface complexes and other data found by spectroscopy as well as molecular dynamics (MD). For the Na+ ion, the fitted CD value points to the presence of bidenate inner-sphere complexation as suggested by a recent MD study. Moreover, its MD dominance quantitatively agrees with the CD model prediction. For Rb+, the presence of a tetradentate complex, as found by spectroscopy, agreed well with the fitted CD and its predicted presence was quantitatively in very good agreement with the amount found by spectroscopy.
Adkins, Harold E.
2013-04-01
Under current U.S. Nuclear Regulatory Commission regulation, it is not sufficient for used nuclear fuel (UNF) to simply maintain its integrity during the storage period, it must maintain its integrity in such a way that it can withstand the physical forces of handling and transportation associated with restaging the fuel and moving it to treatment or recycling facilities, or a geologic repository. Hence it is necessary to understand the performance characteristics of aged UNF cladding and ancillary components under loadings stemming from transport initiatives. Researchers would like to demonstrate that enough information, including experimental support and modeling and simulation capabilities, exists to establish a preliminary determination of UNF structural performance under normal conditions of transport (NCT). This research, development and demonstration (RD&D) plan describes a methodology, including development and use of analytical models, to evaluate loading and associated mechanical responses of UNF rods and key structural components. This methodology will be used to provide a preliminary assessment of the performance characteristics of UNF cladding and ancillary components under rail-related NCT loading. The methodology couples modeling and simulation and experimental efforts currently under way within the Used Fuel Disposition Campaign (UFDC). The methodology will involve limited uncertainty quantification in the form of sensitivity evaluations focused around available fuel and ancillary fuel structure properties exclusively. The work includes collecting information via literature review, soliciting input/guidance from subject matter experts, performing computational analyses, planning experimental measurement and possible execution (depending on timing), and preparing a variety of supporting documents that will feed into and provide the basis for future initiatives. The methodology demonstration will focus on structural performance evaluation of Westinghouse WE 17×17 pressurized water reactor fuel assemblies with a discharge burnup range of 30-58 GWd/MTU (assembly average), loaded in a representative high-capacity (?32 fuel rod assemblies) transportation package. Evaluations will be performed for representative normal conditions of rail transport involving a rail conveyance capable of meeting the Association of American Railroads (AAR) S-2043 specification. UNF modeling is anticipated to be defined to the pellet-cladding level and take in to account influences associated with spacer grids, intermediate fluid mixers, and control components. The influence of common degradation issues such as ductile-to-brittle-transition will also be accounted for. All model development and analysis will be performed with commercially available software packages exclusively. Inputs and analyses will be completely documented, all supporting information will be traceable, and bases will be defendable so as to be most useful to the U.S. Department of Energy community and mission. The expected completion date is the end of fiscal year (FY) 2013.
Shadmehr, Reza
Biological Learning and Control: Shadmehr and Mussa-Ivaldi 1 9 Building generative models as a function of time (passive dynamics), and as a function of the input (active dynamics). What's more
Wang, Taiping; Khangaonkar, Tarang; Long, Wen; Gill, Gary A.
2014-02-07
In recent years, with the rapid growth of global energy demand, the interest in extracting uranium from seawater for nuclear energy has been renewed. While extracting seawater uranium is not yet commercially viable, it serves as a “backstop” to the conventional uranium resources and provides an essentially unlimited supply of uranium resource. With recent advances in seawater uranium extraction technology, extracting uranium from seawater could be economically feasible when the extraction devices are deployed at a large scale (e.g., several hundred km2). There is concern however that the large scale deployment of adsorbent farms could result in potential impacts to the hydrodynamic flow field in an oceanic setting. In this study, a kelp-type structure module was incorporated into a coastal ocean model to simulate the blockage effect of uranium extraction devices on the flow field. The module was quantitatively validated against laboratory flume experiments for both velocity and turbulence profiles. The model-data comparison showed an overall good agreement and validated the approach of applying the model to assess the potential hydrodynamic impact of uranium extraction devices or other underwater structures in coastal oceans.
Mendelsohn, M.; Kreycik, C.
2012-04-01
Utility-scale solar projects have grown rapidly in number and size over the last few years, driven in part by strong renewable portfolio standards (RPS) and federal incentives designed to stimulate investment in renewable energy technologies. This report provides an overview of such policies, as well as the project financial structures they enable, based on industry literature, publicly available data, and questionnaires conducted by the National Renewable Energy Laboratory (NREL).
Taylor, Stuart Glynn
2013-01-01
rotor blade," Structural Health Monitoring, accepted 12-Novdeployed for structural health monitoring applications,"J. -R. Lee, "Structural health monitoring of research-scale
Surawatanawong, Panida
2010-07-14
The electronic structures and reaction mechanisms of transition-metal complexes can be calculated accurately by density functional theory (DFT) in cooperation with the continuum solvation model. The palladium catalyzed ...
Shen, Chen
2015-01-01
We report here a constitutive model for predicting long-term creep strain evolution in ?’ strengthened Ni-base superalloys. Dislocation climb-bypassing ?’, typical in intermediate ?’ volume fraction (~20%) alloys, is considered as the primary deformation mechanism. Dislocation shearing ?’ to anti-phase boundary (APB) faults and diffusional creep are also considered for high-stress and high-temperature low-stress conditions, respectively. Additional damage mechanism is taken into account for rapid increase in tertiary creep strain. The model has been applied to Alloy 282, and calibrated in a temperature range of 1375-1450?F, and stress range of 15-45ksi. The model parameters and a MATLAB code are provided. This report is prepared by Monica Soare and Chen Shen at GE Global Research. Technical discussions with Dr. Vito Cedro are greatly appreciated. This work was supported by DOE program DE-FE0005859
Bharathan, D.; Parsons, B.K.; Althof, J.A.
1988-10-01
The objective of the reported work was to develop analytical methods for evaluating the design and performance of advanced high-performance heat exchangers for use in open-cycle thermal energy conversion (OC-OTEC) systems. This report describes the progress made on validating a one-dimensional, steady-state analytical computer of fresh water experiments. The condenser model represents the state of the art in direct-contact heat exchange for condensation for OC-OTEC applications. This is expected to provide a basis for optimizing OC-OTEC plant configurations. Using the model, we examined two condenser geometries, a cocurrent and a countercurrent configuration. This report provides detailed validation results for important condenser parameters for cocurrent and countercurrent flows. Based on the comparisons and uncertainty overlap between the experimental data and predictions, the model is shown to predict critical condenser performance parameters with an uncertainty acceptable for general engineering design and performance evaluations. 33 refs., 69 figs., 38 tabs.
Liu, Nan; Bisterzo, Sara; Davis, Andrew M; Savina, Michael R; Pellin, Michael J
2014-01-01
We present postprocess AGB nucleosynthesis models with different $^{13}$C-pocket internal structures to better explain zirconium isotope measurements in mainstream presolar SiC grains by Nicolussi et al. (1997) and Barzyk et al. (2007). We show that higher-than-solar $^{92}$Zr/$^{94}$Zr ratios can be predicted by adopting a $^{13}$C-pocket with a flat $^{13}$C profile, instead of the previous decreasing-with-depth $^{13}$C profile. The improved agreement between grain data for zirconium isotopes and AGB models provides additional support for a recent proposal of a flat $^{13}$C profile based on barium isotopes in mainstream SiC grains by Liu et al. (2014).
Liu, Nan; Davis, Andrew M.; Pellin, Michael J. [Department of the Geophysical Sciences, The University of Chicago, Chicago, IL 60637 (United States); Gallino, Roberto; Bisterzo, Sara [Dipartimento di Fisica, Università di Torino, Torino I-10125 (Italy); Savina, Michael R., E-mail: lnsmile@uchicago.edu [Chicago Center for Cosmochemistry, Chicago, IL 60637 (United States)
2014-06-20
We present postprocess asymptotic giant branch (AGB) nucleosynthesis models with different {sup 13}C-pocket internal structures to better explain zirconium isotope measurements in mainstream presolar SiC grains by Nicolussi et al. and Barzyk et al. We show that higher-than-solar {sup 92}Zr/{sup 94}Zr ratios can be predicted by adopting a {sup 13}C-pocket with a flat {sup 13}C profile, instead of the previous decreasing-with-depth {sup 13}C profile. The improved agreement between grain data for zirconium isotopes and AGB models provides additional support for a recent proposal of a flat {sup 13}C profile based on barium isotopes in mainstream SiC grains by Liu et al.
Jiajuan Liang; Peter Bentler
2011-01-01
The model can be expressed as ( Vgi 9i v v w i t h the basicis given by 5 V = cov I \\Vgi I , J S I , w and the between-value v . g g YgO q+(N Vgi N g Under the basic assumptions B
Training Protein Threading Models using Structural SVMs Chun-Nam John Yu CNYU@CS.CORNELL.EDU
Joachims, Thorsten
hundreds long. There are 20 common amino acids, each with different physio-chemical properties. Proteins sequence alone. Comparative modelling of proteins is based on the idea that similar amino acid sequences. 2. Basic Proteomics and Terminology Proteins are sequences of amino acids, typically several
Parresol, Bernard, R.; Scott, Joe, H.; Andreu, Anne; Prichard, Susan; Kurth, Laurie
2012-01-01
Currently geospatial fire behavior analyses are performed with an array of fire behavior modeling systems such as FARSITE, FlamMap, and the Large Fire Simulation System. These systems currently require standard or customized surface fire behavior fuel models as inputs that are often assigned through remote sensing information. The ability to handle hundreds or thousands of measured surface fuelbeds representing the fine scale variation in fire behavior on the landscape is constrained in terms of creating compatible custom fire behavior fuel models. In this study, we demonstrate an objective method for taking ecologically complex fuelbeds from inventory observations and converting those into a set of custom fuel models that can be mapped to the original landscape. We use an original set of 629 fuel inventory plots measured on an 80,000 ha contiguous landscape in the upper Atlantic Coastal Plain of the southeastern United States. From models linking stand conditions to component fuel loads, we impute fuelbeds for over 6000 stands. These imputed fuelbeds were then converted to fire behavior parameters under extreme fuel moisture and wind conditions (97th percentile) using the fuel characteristic classification system (FCCS) to estimate surface fire rate of spread, surface fire flame length, shrub layer reaction intensity (heat load), non-woody layer reaction intensity, woody layer reaction intensity, and litter-lichen-moss layer reaction intensity. We performed hierarchical cluster analysis of the stands based on the values of the fire behavior parameters. The resulting 7 clusters were the basis for the development of 7 custom fire behavior fuel models from the cluster centroids that were calibrated against the FCCS point data for wind and fuel moisture. The latter process resulted in calibration against flame length as it was difficult to obtain a simultaneous calibration against both rate of spread and flame length. The clusters based on FCCS fire behavior parameters represent reasonably identifiable stand conditions, being: (1) pine dominated stands with more litter and down woody debriscomponents than other stands, (2) hardwood and pine stands with no shrubs, (3) hardwood dominated stands with low shrub and high non-woody biomass and high down woody debris, (4) stands with high grass and forb (i.e., non-woody) biomass as well as substantial shrub biomass, (5) stands with both high shrub and litter biomass, (6) pine-mixed hardwood stands with moderate litter biomass and low shrub biomass, and (7) baldcypress-tupelo stands. Models representing these stand clusters generated flame lengths from 0.6 to 2.3 musing a 30 km h{sub 1} wind speed and fireline intensities of 100-1500 kW m{sub 1} that are typical within the range of experience on this landscape. The fuel models ranked 1 < 2 < 7 < 5 < 4 < 3 < 6 in terms of both flame length and fireline intensity. The method allows for ecologically complex data to be utilized in order to create a landscape representative of measured fuel conditions and to create models that interface with geospatial fire models.
Inoue, S; Kusano, K
2016-01-01
We analyze a three-dimensional (3D) magnetic structure and its stability in large solar active region(AR) 12192, using the 3D coronal magnetic field constructed under a nonlinear force-free field (NLFFF) approximation. In particular, we focus on the magnetic structure that produced an X3.1-class flare which is one of the X-class flares observed in AR 12192. According to our analysis, the AR contains multiple-flux-tube system, {\\it e.g.}, a large flux tube, both of whose footpoints are anchored to the large bipole field, under which other tubes exist close to a polarity inversion line (PIL). These various flux tubes of different sizes and shapes coexist there. In particular, the later are embedded along the PIL, which produces a favorable shape for the tether-cutting reconnection and is related to the X-class solar flare. We further found that most of magnetic twists are not released even after the flare, which is consistent with the fact that no observational evidence for major eruptions was found. On the oth...
Configuration Structures (extended abstract)
Pratt, Vaughan
Configuration Structures (extended abstract) R.J. van Glabbeek \\Lambda Computer Science Department Science University of Edinburgh Edinburgh EH9 3JZ, UK gdp@dcs.ed.ac.uk Abstract Configuration structures provide a model of concurÂ rency generalising the families of configurations of event structures. They can
Kratz, Karl-Ludwig; Farouqi, Khalil; Möller, Peter E-mail: kfarouqi@lsw.uni-heidelberg.de
2014-09-01
Attempts to explain the source of r-process elements in our solar system (S.S.) by particular astrophysical sites still face entwined uncertainties, stemming from the extrapolation of nuclear properties far from stability, inconsistent sources of different properties (e.g., nuclear masses and ?-decay properties), and the poor understanding of astrophysical conditions, which are hard to disentangle. In this paper we present results from the investigation of r-process in the high-entropy wind (HEW) of core-collapse supernovae (here chosen as one of the possible scenarios for this nucleosynthesis process), using new nuclear-data input calculated in a consistent approach, for masses and ?-decay properties from the new finite-range droplet model FRDM(2012). The accuracy of the new mass model is 0.56 MeV with respect to AME2003, to which it was adjusted. We compare the new HEW r-process abundance pattern to the latest S.S. r-process residuals and to our earlier calculations with the nuclear-structure quantities based on FRDM(1992). Substantial overall and specific local improvements in the calculated pattern of the r-process between A ? 110 and {sup 209}Bi, as well as remaining deficiencies, are discussed in terms of the underlying spherical and deformed shell structure far from stability.
Karl-Ludwig Kratz; Khalil Farouqi; Peter Möller
2014-06-10
Theoretical studies of the nucleosynthesis origin of the heavy elements in our Solar System (S.S.) by the rapid neutron-capture process (r-process) still face the entwined uncertainties in the possible astrophysical scenarios and the nuclear-physics properties far from stability. In this paper we present results from the investigation of an r-process in the high-entropy wind (HEW) of core-collapse supernovae (here chosen as one of the possible scenarios for this nucleosynthesis process), using new nuclear-data input calculated in a consistent approach, for masses and $\\beta$-decay properties from the new finite-range droplet model FRDM(2012). The accuracy of the new mass model is 0.56 MeV with respect to {\\sc AME2003}, to which it was adjusted. We compare the new HEW r-process abundance pattern to the latest S.S. r-process residuals and to our earlier calculations with the nuclear-structure quantities based on FRDM(1992). Substantial overall and specific local improvements in the calculated pattern of the r-process between $A\\simeq 110$ and $^{209}$Bi, as well as remaining deficiencies are discussed in terms of the underlying spherical and deformed shell structure far from stability.
Growth of sheets in 3D confinements - a model for the C-S-H meso 2 structure
Etzold, Merlin A.; McDonald, Peter J.; Routh, Alexander F.
2014-06-21
C-S-H [1]. However,158 we note that the sheet orientation in fibrillar micrographs appears orthogonal to that in the simulation.159 The closing of larger pores as seen in the sequence Figure 3a-b can mechanistically explain the densi-160 fication... .20 2.0 0 02 5 6 8 P0 rog resVaVNeoml i eet al. di al TmVGl Tewt Vhl eRWwWDml di al TmVGl Tewt Vhl eWi RWwWDml rhVaal TWi f ehI TRl en h p022ei ewt Al Tl Figure 6: Example scattering curves obtained for structure (h) in Figure 3 together with small...
Modeling Quality Information within Business Process Models
Paech, Barbara
Modeling Quality Information within Business Process Models Robert Heinrich, Alexander Kappe. Business process models are a useful means to document information about structure and behavior literature and tool survey on modeling quality information within business process models. Keywords: Business
Francisco Delgado
2014-10-28
Entanglement is considered as a basic physical resource for modern quantum applications in Quantum Information and Quantum Computation theories. Interactions able to generate and sustain entanglement are subject to deep research in order to have understanding and control on it, based on specific physical systems. Atoms, ions or quantum dots are considered a key piece in quantum applications because is a basic piece of developments towards a scalable spin-based quantum computer through universal and basic quantum operations. Ising model is a type of interaction which generates and modi?es entanglement properties of quantum systems based on matter. In this work, a general anisotropic three dimensional Ising model including an inhomogeneous magnetic field is analyzed to obtain their evolution and then, their algebraic properties which are controlled through a set of physical parameters. Evolution denote remarkable group properties when is analyzed in a non local basis, in particular those related with entanglement. These properties give a fruitful arena for further quantum applications and their control.
Y. Wei; D. J. Durian
2013-04-30
To probe the effects of hydrogel particle additives on the water-accessible pore structure of sandy soils, we introduce a custom pressure plate method in which the volume of water expelled from a wet granular packing is measured as a function of applied pressure. Using a capillary bundle model, we show that the differential change in retained water per pressure increment is directly related to the cumulative cross-sectional area distribution $f(r)$ of the water-accessible pores with radii less than $r$. This is validated by measurements of water expelled from a model sandy soil composed of 2 mm diameter glass beads. In particular, the expelled water is found to depend dramatically on sample height and that analysis using the capillary bundle model gives the same pore size distribution for all samples. The distribution is found to be approximately log-normal, and the total cross-sectional area fraction of the accessible pore space is found to be $f_0=0.34$. We then report on how the pore distribution and total water-accessible area fraction are affected by superabsorbent hydrogel particle additives, uniformly mixed into a fixed-height sample at varying concentrations. Under both fixed volume and free swelling conditions, the total area fraction of water-accessible pore space in a packing decreases exponentially as the gel concentration increases. The size distribution of the pores is significantly modified by the swollen hydrogel particles, such that large pores are clogged while small pores are formed.
Deforming convex RP3-structures on 3-orbifolds Deforming convex RP3-structures on 3-orbifolds
Choi, Suhyoung
Deforming convex RP3-structures on 3-orbifolds Deforming convex RP3-structures on 3-orbifolds-structures on 3-orbifolds Outline A RPn-structure (projectively flat structure; real projective structure; projective structure) on an orbifold is a geometric structure on the orbifold modelled on (RPn, PGL(n + 1, R
Vuk Milisic; Dietmar Oelz
2015-06-03
We consider a microscopic model for friction mediated by transient elastic linkages introduced in [V. Milisic and D. Oelz. SIAM J. on Math. Anal. (2015). V. Milisic and D. Oelz. J. Math. Pures Appl. (2011)]. In the present study we prove existence and uniqueness of a solution to the coupled system under weaker hypotheses. The theory we present covers the case where the off-rate of linkages is unbounded but increasing at most linearly with respect to the mechanical load. The time of existence is typically bounded and corresponds to tear-off where the moving binding site does not have any bonds with the substrate. However, under additional assumptions on the external force we prove global in time existence of a solution that consequently stays attached to the substrate.
Myrent, Noah J.; Kusnick, Joshua F.; Barrett, Natalie C.; Adams, Douglas E.; Griffith, Daniel Todd
2013-04-01
Operations and maintenance costs for offshore wind plants are significantly higher than the current costs for land-based (onshore) wind plants. One way to reduce these costs would be to implement a structural health and prognostic management (SHPM) system as part of a condition based maintenance paradigm with smart load management and utilize a state-based cost model to assess the economics associated with use of the SHPM system. To facilitate the development of such a system a multi-scale modeling approach developed in prior work is used to identify how the underlying physics of the system are affected by the presence of damage and faults, and how these changes manifest themselves in the operational response of a full turbine. This methodology was used to investigate two case studies: (1) the effects of rotor imbalance due to pitch error (aerodynamic imbalance) and mass imbalance and (2) disbond of the shear web; both on a 5-MW offshore wind turbine in the present report. Based on simulations of damage in the turbine model, the operational measurements that demonstrated the highest sensitivity to the damage/faults were the blade tip accelerations and local pitching moments for both imbalance and shear web disbond. The initial cost model provided a great deal of insight into the estimated savings in operations and maintenance costs due to the implementation of an effective SHPM system. The integration of the health monitoring information and O&M cost versus damage/fault severity information provides the initial steps to identify processes to reduce operations and maintenance costs for an offshore wind farm while increasing turbine availability, revenue, and overall profit.
Effect of alcohols on aqueous lysozyme-lysozyme interactions from static
Office of Scientific and Technical Information (OSTI)
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 Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article) | SciTech ConnectExperimentsGAMMA-RAYNp, Pu, and Am): A
Abdel Nasser Tawfik; Niseem Magdy
2015-01-06
Effects of external magnetic field on various properties of the quantum chromodynamics under extreme conditions of temperature and density have been analysed. To this end, we use SU(3) Polyakov linear sigma-model and assume that the external magnetic field eB adds some restrictions to the quarks energy due to the existence of free charges in the plasma phase. In doing this, we apply the Landau theory of quantization. This requires an additional temperature to drive the system through the chiral phase-transition. Accordingly, the dependence of the critical temperature of chiral and confinement phase-transitions on the magnetic field is characterized. Based on this, we have studied the thermal evolution of thermodynamic quantities and the first four higher-order moment of particle multiplicity. Having all these calculations, we have studied the effects of magnetic field on chiral phase-transition. We found that both critical temperature T_c and critical chemical potential increase with increasing the magnetic field eB. Last but not least, the magnetic effects of the thermal evolution of four scalar and four pseudoscalar meson states are studied. We concluded that the meson masses decrease as the temperature increases till T_c. Then, the vacuum effect becomes dominant and rapidly increases with the temperature T. At low T, the scalar meson masses normalized to the lowest Matsubara frequency rapidly decreases as T increases. Then, starting from T_c, we find that the thermal dependence almost vanishes. Furthermore, the meson masses increase with increasing magnetic field. This gives characteristic phase diagram of T vs. external magnetic field $B. At high T, we find that the masses of almost all meson states become temperature independent. It is concluded that the various meson states likely have different T_c's.
Protein Localization in Silica Nanospheres Derived via Biomimetic Mineralization
Cardoso, Mateus B [ORNL; Luckarift, Heather [Air Force Research Laboratory; Urban, Volker S [ORNL; O'Neill, Hugh Michael [ORNL; Johnson, Glenn [Air Force Research Laboratory
2010-01-01
Lysozyme-templated precipitation of silica synthesized by sol-gel chemistry produces a composite material with antimicrobial properties. This study investigates the structural properties of the composite material that allow for retention of the antimicrobial activity of lysozyme. Scanning (SEM) and transmission (TEM) electron microscopy reveal that the composite has a hierarchical structure composed of quasi-spherical structures ({approx}450 nm diameter), which are in turn composed of closely packed spherical structures of {approx}8-10 nm in diameter. Using small-angle neutron scattering (SANS) with contrast variation, the scattering signatures of the lysozyme and silica within the composite were separated. It was determined that the lysozyme molecules are spatially correlated in the material and form clusters with colloidal silica particles. The size of the clusters determined by SANS agrees well with the structural architecture observed by TEM. BET analysis revealed that the surface area of the composite is relatively low (4.73 m{sup 2}/g). However, after removal of the protein by heating to 200 C, the surface area is increased by {approx}20%. In addition to demonstrating a well organized sol-gel synthesis which generates a functional material with antimicrobial applications, the analysis and modeling approaches described herein can be used for characterizing a wide range of mesoporous and ultrastructural materials.
$\\mathbb{P}^1$-bundle bases and the prevalence of non-Higgsable structure in 4D F-theory models
James Halverson; Washington Taylor
2015-07-03
We explore a large class of F-theory compactifications to four dimensions. We find evidence that gauge groups that cannot be Higgsed without breaking supersymmetry, often accompanied by associated matter fields, are a ubiquitous feature in the landscape of ${\\cal N} = 1$ 4D F-theory constructions. In particular, we study 4D F-theory models that arise from compactification on threefold bases that are $\\mathbb{P}^1$ bundles over certain toric surfaces. These bases are one natural analogue to the minimal models for base surfaces for 6D F-theory compactifications. Of the roughly 100,000 bases that we study, only 80 are weak Fano bases in which there are no automatic singularities on the associated elliptic Calabi-Yau fourfolds, and 98.3% of the bases have geometrically non-Higgsable gauge factors. The $\\mathbb{P}^1$-bundle threefold bases we analyze contain a wide range of distinct surface topologies that support geometrically non-Higgsable clusters. Many of the bases that we consider contain $SU(3)\\times SU(2)$ seven-brane clusters for generic values of deformation moduli; we analyze the relative frequency of this combination relative to the other four possible two-factor non-Higgsable product groups, as well as various other features such as geometrically non-Higgsable candidates for dark matter structure and phenomenological ($SU(2)$-charged) Higgs fields.
Eigenbehaviors: Identifying Structure in Routine
Pentland, Alex Paul
Longitudinal behavioral data generally contains a significant amount of structure. In this work, we identify the structure inherent in daily behavior with models that can accurately analyze, predict, and cluster multimodal ...
Goldstein, R.A.; Bornberg-Bauer, E.
1996-12-31
This session provides evolutionary perspectives on biopolymer structures, namely DNA, RNA and proteins. Structural models are presented and the structure and function relationships are discussed.
COMBINATORIAL MODELS FOR COALGEBRAIC STRUCTURES
Ray, Nige
- jects, known as cell-sets, on which we study the properties of the appro- priate free abelian introduce the category Cell of cell-sets and study its simpler internal properties. An appropriate functor Z to novel comodules and quotient coal- gebras. Parallels with algebraic topology have motivated several
Variational Models for Fine Structures
Schaeffer, Hayden
2013-01-01
78] M. Zhou, H. Chen, J. Paisley, L. Ren, G. Sapiro, and L.26] and Zhou, Chen, Paisley, Ren, Sapiro, and Carin [78
Chong, Hogun
2004-09-30
This research explored the causal relationships among strategies, corporate structure, and performance of the largest U.S. non-financial firms using Directed Acyclic Graphs (DAGs). Corporate strategies and structure have been analyzed as major...
Taylor, Stuart Glynn
2013-01-01
community in the application of piezoelectric transducers: (piezoelectric transducers under cyclic loads deployed for structural health monitoring applications,"piezoelectric transducers under cyclic loads deployed for structural health monitoring applications,"
, May 1993 A COMPUTATIONAL APPROACH TO THE DESIGN OF MICROMECHANICAL HINGED STRUCTURES Karl-Friedrich B for the design of micromechanical hinged structures. These devices Pister et al. 1992 are particularly attractive y describe micromechanical hinged structures, and give an overview on our approach for design
in the production, processing, storing, refining, and transportation of crude oil as well as the storage85000. PADD I PADD II PADD III PADD IV PADD V Model Structure Crude Oil @ SPR Crude Oil @ Processing Plants Crude Oil @ Refineries Fuel @ Importation Terminals Fuel @ Refineries Fuel @ Distributors
Broader source: Energy.gov [DOE]
DOE Geothermal Technologies Peer Review 2010 - Presentation. Relevance of research: Improve exploration technologies for range-hosted geothermal systems:Employ new concept models and apply existing methods in new ways; Breaking geothermal exploration tasks into new steps, segmenting the problem differently; Testing new models for dilatent structures; Utilizing shallow thermal aquifer model to focus exploration; Refining electrical interpretation methods to map shallow conductive featuresIdentifying key faults as fluid conduits; and Employ soil gas surveys to detect volatile elements and gases common to geothermal systems.
Computational RNA Secondary Structure Design
Fournier, John J.F.
Computational RNA Secondary Structure Design: Empirical Complexity and Improved Methods by Rosal in this thesis is focused on the design of RNA strands that are predicted to fold to a given secondary structure, according to a standard thermodynamic model. The design of RNA structures is important for applications
McMains, Sara
not provide this information, which the ap- plication must then derive as it builds its own topological data. In this paper, we describe a new out-of-core al- gorithm that can build a topological data structure efficiently in memory, it is efficient for the application to build up its own topological data structure by in
Julia, J; Nyblade, A; Hansen, S; Rodgers, A; Matzel, E
2009-07-06
In this project, we are developing models of lithospheric structure for a wide variety of tectonic regions throughout Eurasia and the Middle East by regionalizing 1D velocity models obtained by jointly inverting P-wave and S-wave receiver functions with Rayleigh wave group and phase velocities. We expect the regionalized velocity models will improve our ability to predict travel-times for local and regional phases, such as Pg, Pn, Sn and Lg, as well as travel-times for body-waves at upper mantle triplication distances in both seismic and aseismic regions of Eurasia and the Middle East. We anticipate the models will help inform and strengthen ongoing and future efforts within the NNSA labs to develop 3D velocity models for Eurasia and the Middle East, and will assist in obtaining model-based predictions where no empirical data are available and for improving locations from sparse networks using kriging. The codes needed to conduct the joint inversion of P-wave receiver functions (PRFs), S-wave receiver functions (SRFs), and dispersion velocities have already been assembled as part of ongoing research on lithospheric structure in Africa. The methodology has been tested with synthetic 'data' and case studies have been investigated with data collected at an open broadband stations in South Africa. PRFs constrain the size and S-P travel-time of seismic discontinuities in the crust and uppermost mantle, SRFs constrain the size and P-S travel-time of the lithosphere-asthenosphere boundary, and dispersion velocities constrain average S-wave velocity within frequency-dependent depth-ranges. Preliminary results show that the combination yields integrated 1D velocity models local to the recording station, where the discontinuities constrained by the receiver functions are superimposed to a background velocity model constrained by the dispersion velocities. In our first year of this project we will (i) generate 1D velocity models for open broadband seismic stations in the western half of the study area (Eurasia and the Middle East) and (ii) identify well located seismic events with event-station paths isolated to individual tectonic provinces within the study area and collect broadband waveforms and source parameters for the selected events. The 1D models obtained from the joint inversion will then be combined with published geologic terrain maps to produce regionalized models for distinctive tectonic areas within the study area, and the models will be validated through full waveform modeling of well-located seismic events recorded at local and regional distances.
Silberschatz, Avi
. The various data models that have been proposed fall into three di erent groups: object-based logical models, record-based logical models, and physical data models. Physical data models are used to describe data models. Object-based logical models provide exible structuring capabilities and allow data constraints
Seismic Category I Structures Program
Bennett, J.G.; Dunwoody, W.E.; Farrar, C.R.
1985-01-01
With the use of different size scale models, the Seismic Category I Structures Program has demonstrated consistent results for measured values of stiffness at working loads. Furthermore, the values are well below the theoretical stiffnesses calculated from an uncracked strength-of-materials approach. The scale model structures, which are also models of each other, have demonstrated scalability between models. The current effort is to demonstrate that the use of microconcrete and other modeling effects do not introduce significant distortions that could drastically change conclusions regarding prototype behavior for these very stiff, shear-dominated structures. Working closely with the technical review group (TRG) for this program, structures have been designed and tests have been planned that will help to resolve issues surrounding the use of microconcrete scale models.
Thawabi, Hassan S
2013-04-16
. These magnetic properties are mainly attributed to the martensitic structural phase trans- formation these material experience in response to temperature variation. Co-Ni-Al based alloys are one of the most promising ferromagnetic shape memory alloy FSMA that has...
STRUCTURAL ORGANIZATION AND STRUCTURAL INTEGRATION
Hingers, Robert H.
1976-01-01
of businesses and marriages, and (2) failure rates of variously structured intentional communities. Both tests support the hypothesis that communal organizations, which permit structural freewheeling, are more stable than formal organizations, which donot....
Baldwin, Moira Jenkins
2012-11-09
? conceptual understandings, few studies have studied changing students? initial and synthetic mental models into scientific ones (Diakidoy & Kendeou, 2001; Hayes, Goodhew, Heit, & Gillan, 2003; Sharp & Kuerbis, 2006). 3 Since inquiry-based learning... Mental Models Several researchers have studied how classroom instruction changes students? mental models (Diakidoy & Kendeou, 2001; Hayes, Goodhew, Heit, & Gillan, 2003; Kangassalo, 1993, 1994, 1997, 1999; Taylor, Barker, and Jones, 2003). Diakidoy...
Hisham Sati
2015-01-16
String structures in degree four are associated with cancellation of anomalies of string theory in ten dimensions. Fivebrane structures in degree eight have recently been shown to be associated with cancellation of anomalies associated to the NS5-brane in string theory as well as the M5-brane in M-theory. We introduce and describe "Ninebrane structures" in degree twelve and demonstrate how they capture some anomaly cancellation phenomena in M-theory. Along the way we also define certain variants, considered as intermediate cases in degree nine and ten, which we call "2-Orientation" and "2-Spin structures", respectively. As in the lower degree cases, we also discuss the natural twists of these structures and characterize the corresponding topological groups associated to each of the structures, which likewise admit refinements to differential cohomology.
Milner, Fabio Augusto
Sciences, Arizona State University, P.O. Box 871804 Tempe, AZ 85287, United States milner@asu.edu LAURENTIU-epidemiological model? In almost all epidemiological models, the death rates and the recovery rates are either constant SEGA Department of Mathematics, Georgia Regents University, 1120 15th Street, Augusta, GA 30912, United
Black, Charles Beyer
2004-11-15
Three experiments compared learning of relative and absolute timing of a sequential key-pressing task by physical and observational practice. Experiment 1 compared a task with a complex internal structure (goal proportions of 22.2, 44.4, 33...
Pontil, Massimiliano
.mourao-miranda, m.pontil}@cs.ucl.ac.uk Abstract--Structured sparsity methods have been re- cently proposed Total Variation can mitigate some of the instability inherent in simpler sparse methods, but more techniques are being increasingly used in the analysis of brain imaging data for their inherent ability
Dirac structures Port-Hamiltonian systems
Batlle, Carles
Dirac structures Port-Hamiltonian systems Exercises Dirac structures and port-Hamiltonian systems. Interconnection and model order reduction Seminar 1 - Dirac structures and port-Hamiltonian systems Carles Batlle structures Port-Hamiltonian systems Exercises Key references M. Dalsmo and A. van der Schaft, "On
Narrowband Control Design for Smart Structural Systems
Narrowband Control Design for Smart Structural Systems Daniel J. Kolepp and Ralph C. Smith 1 Center structures but is suÆciently simple to facilitate initial control design. A PDE model for the structure be employed for structural acoustic control design or control of adjacent ows. In this paper, we focus
STRUCTURAL AND MECHANICAL EFFECTS OF RADIATION EXPOSURE ON FILLED...
Office of Scientific and Technical Information (OSTI)
STRUCTURAL AND MECHANICAL EFFECTS OF RADIATION EXPOSURE ON FILLED ELASTOMERS - RECENT INSIGHTS FROM EXPERIMENTS AND MODELING Citation Details In-Document Search Title: STRUCTURAL...
Tong, Fuhui
2009-05-15
This quantitative study derived from an on-going federal experimental research project targeting Spanish-speaking English language learners (ELLs) receiving services in four program models: control/experimental transitional ...
Experiential learning environments for structural behavior
Viteri, Victor R. (Victor Raul)
2003-01-01
Computers have dramatically changed the nature of structural engineering practice by shifting work from process-oriented tasks, such as performing hand calculations and drafting, to structural modeling and interpretation ...
Hydrogen embrittlement of structural steels.
Somerday, Brian P.
2010-06-01
Carbon-manganese steels are candidates for the structural materials in hydrogen gas pipelines, however it is well known that these steels are susceptible to hydrogen embrittlement. Decades of research and industrial experience have established that hydrogen embrittlement compromises the structural integrity of steel components. This experience has also helped identify the failure modes that can operate in hydrogen containment structures. As a result, there are tangible ideas for managing hydrogen embrittement in steels and quantifying safety margins for steel hydrogen containment structures. For example, fatigue crack growth aided by hydrogen embrittlement is a key failure mode for steel hydrogen containment structures subjected to pressure cycling. Applying appropriate structural integrity models coupled with measurement of relevant material properties allows quantification of safety margins against fatigue crack growth in hydrogen containment structures. Furthermore, application of these structural integrity models is aided by the development of micromechanics models, which provide important insights such as the hydrogen distribution near defects in steel structures. The principal objective of this project is to enable application of structural integrity models to steel hydrogen pipelines. The new American Society of Mechanical Engineers (ASME) B31.12 design code for hydrogen pipelines includes a fracture mechanics-based design option, which requires material property inputs such as the threshold for rapid cracking and fatigue crack growth rate under cyclic loading. Thus, one focus of this project is to measure the rapid-cracking thresholds and fatigue crack growth rates of line pipe steels in high-pressure hydrogen gas. These properties must be measured for the base materials but more importantly for the welds, which are likely to be most vulnerable to hydrogen embrittlement. The measured properties can be evaluated by predicting the performance of the pipeline using a relevant structural integrity model, such as that in ASME B31.12. A second objective of this project is to enable development of micromechanics models of hydrogen embrittlement in pipeline steels. The focus of this effort is to establish physical models of hydrogen embrittlement in line pipe steels using evidence from analytical techniques such as electron microscopy. These physical models then serve as the framework for developing sophisticated finite-element models, which can provide quantitative insight into the micromechanical state near defects. Understanding the micromechanics of defects can ensure that structural integrity models are applied accurately and conservatively.
STRICTLY CONVERGENT ANALYTIC STRUCTURES 1 ...
2014-04-07
the field L can be turned into an LK-model with the valued field structure for the .... the solutions of certain systems of equations may have power series solutions ...
Fenglei Li
2006-08-09
The purposes of our research were: (1) To develop an economical, easy to use, automated, high throughput system for large scale protein crystallization screening. (2) To develop a new protein crystallization method with high screening efficiency, low protein consumption and complete compatibility with high throughput screening system. (3) To determine the structure of lactate dehydrogenase complexed with NADH by x-ray protein crystallography to study its inherent structural properties. Firstly, we demonstrated large scale protein crystallization screening can be performed in a high throughput manner with low cost, easy operation. The overall system integrates liquid dispensing, crystallization and detection and serves as a whole solution to protein crystallization screening. The system can dispense protein and multiple different precipitants in nanoliter scale and in parallel. A new detection scheme, native fluorescence, has been developed in this system to form a two-detector system with a visible light detector for detecting protein crystallization screening results. This detection scheme has capability of eliminating common false positives by distinguishing protein crystals from inorganic crystals in a high throughput and non-destructive manner. The entire system from liquid dispensing, crystallization to crystal detection is essentially parallel, high throughput and compatible with automation. The system was successfully demonstrated by lysozyme crystallization screening. Secondly, we developed a new crystallization method with high screening efficiency, low protein consumption and compatibility with automation and high throughput. In this crystallization method, a gas permeable membrane is employed to achieve the gentle evaporation required by protein crystallization. Protein consumption is significantly reduced to nanoliter scale for each condition and thus permits exploring more conditions in a phase diagram for given amount of protein. In addition, evaporation rate can be controlled or adjusted in this method during the crystallization process to favor either nucleation or growing processes for optimizing crystallization process. The protein crystals gotten by this method were experimentally proven to possess high x-ray diffraction qualities. Finally, we crystallized human lactate dehydrogenase 1 (H4) complexed with NADH and determined its structure by x-ray crystallography. The structure of LDH/NADH displays a significantly different structural feature, compared with LDH/NADH/inhibitor ternary complex structure, that subunits in LDH/NADH complex show open conformation or two conformations on the active site while the subunits in LDH/NADH/inhibitor are all in close conformation. Multiple LDH/NADH crystals were obtained and used for x-ray diffraction experiments. Difference in subunit conformation was observed among the structures independently solved from multiple individual LDH/NADH crystals. Structural differences observed among crystals suggest the existence of multiple conformers in solution.
Unfolding designable structures
Cristiano L. Dias; Martin Grant
2005-10-17
Among an infinite number of possible folds, nature has chosen only about 1000 distinct folds to form protein structures. Theoretical studies suggest that selected folds are intrinsically more designable than others; these selected folds are unusually stable, a property called the designability principle. In this paper we use the 2D hydrophobic-polar lattice model to classify structures according to their designability, and Langevin dynamics to account for their time evolution. We demonstrate that, among all possible folds, the more designable ones are easier to unfold due to their large number of surface-core bonds.
Takahashi, Hironori; Fredrickson, E. D.; Schaffer, M. J.
2008-04-15
The plasma in tokamaks often exhibits a relaxation oscillation called the edge localized mode (ELM), which is generally attributed to MHD instability driven by strong gradients at the plasma boundary. It is shown here that field-aligned currents flowing just outside the boundary may also play a role in the ELM process. The poloidal perturbation magnetic field during ELMs in the DIII–D tokamak calculated from measured currents can reproduce prominent observed features, including a narrow magnetic structure at the outboard midplane similar to filaments observed earlier in DIII–D and NSTX.
Topological classification of RNA structures
Michael Bon; Graziano Vernizzi; Henri Orland; A. Zee
2006-07-21
We present a novel topological classification of RNA secondary structures with pseudoknots. It is based on the topological genus of the circular diagram associated to the RNA base-pair structure. The genus is a positive integer number, whose value quantifies the topological complexity of the folded RNA structure. In such a representation, planar diagrams correspond to pure RNA secondary structures and have zero genus, whereas non planar diagrams correspond to pseudoknotted structures and have higher genus. We analyze real RNA structures from the databases wwPDB and Pseudobase, and classify them according to their topological genus. We compare the results of our statistical survey with existing theoretical and numerical models. We also discuss possible applications of this classification and show how it can be used for identifying new RNA structural motifs.
Manuel, Lance
, Toronto, August 2003. EFFICIENT MODELS FOR WIND TURBINE EXTREME LOADS USING INVERSE RELIABILITY K, USA ABSTRACT The reliability of wind turbines against extreme loads is the focus of this study loads for a 600kW three-bladed horizontal-axis wind turbine. Only operating loads here, flapwise (out
King, Joshua David
2005-02-17
are produced as a result of interaction of the transmitter generated primary fields with the seawater and subsurface. Badea et al. (2001) coded an existing algorithm for solving Maxwell?s equations. This finite element 3D forward modeling algorithm is used...
Manuel, Lance
-moment model not to the stress ranges themselves, but to a power-law transformation of these that directly and with diameters over 65 meters are on the market, producing electricity for prices below $0.04/kWh in good wind exponentially. BTM Consult (a Danish wind energy consulting firm) reports that in 1998 2,600 MW of wind power
Chun, J.-S.; Desjardins, P.; Lavoie, C.; Shin, C.-S.; Cabral, C.; Petrov, I.; Greene, J. E.
2001-06-15
Single-crystal TiN(111) layers, 45 nm thick, were grown on MgO(111) by ultrahigh vacuum reactive magnetron sputter deposition in pure N{sub 2} discharges at T{sub s}=700{degree}C. Epitaxial Al(111) overlayers, 160 nm thick, were then deposited at T{sub s}=100{degree}C in Ar without breaking vacuum. Interfacial reactions and changes in bilayer microstructure due to annealing at 620 and 650{degree}C were investigated using x-ray diffraction and transmission electron microscopy (TEM). The interfacial regions of samples annealed at 620{degree}C consist of continuous {approx_equal}7-nm-thick epitaxial wurtzite-structure AlN(0001) layers containing a high density of stacking faults, with {approx_equal}22 nm thick tetragonal Al{sub 3}Ti(112) overlayers. Surprisingly, samples annealed at the higher temperature are more stable against Al{sub 3}Ti formation. TEM analyses of bilayers annealed at 650{degree}C (10{degree}C below the Al melting point!) reveal only the self-limited growth of an {approx_equal}3-nm-thick interfacial layer of perfect smooth epitaxial wurtzite-structure AlN(0001) which serves as an extremely effective deterrent for preventing further interlayer reactions. {copyright} 2001 American Institute of Physics.
DAMAGE ASSESSMENT OF COMPOSITE PLATE STRUCTURES WITH UNCERTAINTY
Boyer, Edmond
DAMAGE ASSESSMENT OF COMPOSITE PLATE STRUCTURES WITH UNCERTAINTY Chandrashekhar M.* , Ranjan Uncertainties associated with a structural model and measured vibration data may lead to unreliable damage that material uncertainties in composite structures cause considerable problem in damage assessment which can
Design and Fabrication of Complex Flexible Structures and Microarchitectures
Mease, Kenneth D.
Design and Fabrication of Complex Flexible Structures and Microarchitectures The ability to design and fabricate complex flexible structures is becoming increasingly important using flexible structures because design tools for creating them are limited and modeling
Vacuum Structure and Potential
J. X. Zheng-Johansson
2007-04-02
Based on overall experimental observations, especially the pair processes, I developed a model structure of the vacuum along with a basic-particle formation scheme begun in 2000 (with collaborator P-I Johansson). The model consists in that the vacuum is, briefly, filled of neutral but polarizable vacuuons, consisting each of a p-vaculeon and n- vaculeon of charges $+e$ and $-e$ of zero rest masses but with spin motions, assumed interacting each other with a Coulomb force. The model has been introduced in full in a book (Nova Sci, 2005) and referred to in a number of journal/E-print papers. I outline in this easier accessible paper the detailed derivation of the model and a corresponding quantitative determination of the vacuuon size.
Interactions of Lysozyme in Guanidinium Chloride Solutions FromStatic...
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Resource Type: Journal Article Resource Relation: Journal Name: Biotechnology Bioengineering; Journal Volume: 90; Journal Issue: 4; Related Information: Journal Publication...
Interactions of Lysozyme in Guanidinium Chloride Solutions FromStatic
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Frantzis, L.; Graham, S.; Katofsky, R.; Sawyer, H.
2008-02-01
This report summarizes work to better understand the structure of future photovoltaics business models and the research, development, and demonstration required to support their deployment.
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Current Collaborations Past Collaborations NSEC Engineering Institute Structural Health Monitoring Engineering Institute Structural Health Monitoring- Test Structures &...
RESEARCH ARTICLE Population structure, dispersal and colonization history
the population structure of the bumblebee Bombus hortorum in a model island system, the Western Isles of Scotland
Pattanayek, Rekha; Williams, Dewight R.; Pattanayek, Sabuj; Mori, Tetsuya; Johnson, Carl H.; Stewart, Phoebe L.; Egli, Martin
2010-03-08
The circadian clock of the cyanobacterium Synechococcus elongatus can be reconstituted in vitro by the KaiA, KaiB and KaiC proteins in the presence of ATP. The principal clock component, KaiC, undergoes regular cycles between hyper- and hypo-phosphorylated states with a period of ca. 24 h that is temperature compensated. KaiA enhances KaiC phosphorylation and this enhancement is antagonized by KaiB. Throughout the cycle Kai proteins interact in a dynamic manner to form complexes of different composition. We present a three-dimensional model of the S. elongatus KaiB-KaiC complex based on X-ray crystallography, negative-stain and cryo-electron microscopy, native gel electrophoresis and modelling techniques. We provide experimental evidence that KaiB dimers interact with KaiC from the same side as KaiA and for a conformational rearrangement of the C-terminal regions of KaiC subunits. The enlarged central channel and thus KaiC subunit separation in the C-terminal ring of the hexamer is consistent with KaiC subunit exchange during the dephosphorylation phase. The proposed binding mode of KaiB explains the observation of simultaneous binding of KaiA and KaiB to KaiC, and provides insight into the mechanism of KaiB's antagonism of KaiA.
Schmidt, Frank (Langenhagen, DE); Allais, Arnaud (Hannover, DE); Mirebeau, Pierre (Villebon sur Yvette, FR); Ganhungu, Francois (Vieux-Reng, FR); Lallouet, Nicolas (Saint Martin Boulogne, FR)
2009-10-20
A terminal structure (2) for a superconducting cable (1) is described. It consists of a conductor (2a) and an insulator (2b) that surrounds the conductor (2a), wherein the superconducting cable (1) has a core with a superconducting conductor (5) and a layer of insulation that surrounds the conductor (5), and wherein the core is arranged in such a way that it can move longitudinally in a cryostat. The conductor (2a) of the terminal structure (2) is electrically connected with the superconducting conductor (5) or with a normal conductor (6) that is connected with the superconducting conductor (5) by means of a tubular part (7) made of an electrically conductive material, wherein the superconducting conductor (5) or the normal conductor (6) can slide in the part (7) in the direction of the superconductor.
Kwon, Chuhee (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM); Foltyn, Stephen R. (Los Alamos, NM)
2003-04-01
A superconductive structure including a dielectric oxide substrate, a thin buffer layer of a superconducting material thereon; and, a layer of a rare earth-barium-copper oxide superconducting film thereon the thin layer of yttrium-barium-copper oxide, the rare earth selected from the group consisting of samarium, gadolinium, ytterbium, erbium, neodymium, dysprosium, holmium, lutetium, a combination of more than one element from the rare earth group and a combination of one or more elements from the rare earth group with yttrium, the buffer layer of superconducting material characterized as having chemical and structural compatibility with the dielectric oxide substrate and the rare earth-barium-copper oxide superconducting film is provided.
Kwon, Chuhee (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM); Foltyn, Stephen R. (Los Alamos, NM)
2005-09-13
A superconductive structure including a dielectric oxide substrate, a thin buffer layer of a superconducting material thereon; and, a layer of a rare earth-barium-copper oxide superconducting film thereon the thin layer of yttrium-barium-copper oxide, the rare earth selected from the group consisting of samarium, gadolinium, ytterbium, erbium, neodymium, dysprosium, holmium, lutetium, a combination of more than one element from the rare earth group and a combination of one or more elements from the rare earth group with yttrium, the buffer layer of superconducting material characterized as having chemical and structural compatibility with the dielectric oxide substrate and the rare earth-barium-copper oxide superconducting film is provided.
Pascale Garaud; Douglas N. C. Lin
2006-07-19
We construct a new set of self-consistent analytical disk models by taking into account both viscous and radiative sources of thermal energy. We analyze the non-isothermal structure of the disk across the mid-plane for optically thick disks, and use the standard two-temperature model in the case of optically thin disks. We deduce a set of general formula for the relationship between the mass accretion rate and the surface density profile. Our results recover those of Chiang & Goldreich in the optically thin regions, but extend their work for the opaque regions of the disk. For the purpose of illustration, we apply our theory in this paper to determine the structure of protostellar disks around T Tauri stars under a state of steady accretion and derive the corresponding radial distribution function of various disk properties such as surface density and temperature near the mid-plane. We calculate the position of the snow line around a sun-like T Tauri star, and deduce that it can evolve from well outside 10 AU during FU Orionis outbursts, to about 4 AU during passive accretion phase, to the present-day orbital radius of Venus and finally re-expand to over 2.2 AU during the protostellar- to-debris disk transition. This non-monotonous evolution of the snow line may provide some novel and deterministic explanation for the total water content and its isotopic composition of both Venus and the Earth. In the optically thin, outermost regions of the disk we find that the surface density profile of the dust varies roughly as 1/r, which is consistent with mm observations of spatially resolved disk of Mundy et al. (2000).
Inherent structure of a molten salt
La Violette, Randall A.; Budzien, Joanne L.; Stillinger, Frank H.
2000-05-08
We calculated the inherent structure of a model melt of zinc (II) bromide over a wide range of densities. Stable, metastable, and unstable branches were obtained for the zero temperature pressure-volume isotherm of the inherent structure. The pressure-volume isotherm, the void distribution, and the structure factor were used to identify the spinodal, independent of any model equation of state. (c) 2000 American Institute of Physics.
Structural Modeling and Analysis of Structures in Aorta Images
Xu, Hai
2012-10-19
). ........................ 10 Figure 4. A synthetic binary image consisting of five sinusoidal curves was used to verify the accuracy of my Radon Transform (RT) algorithm. ............ 14 Figure 5. Computed angle for the principal (circumferential) direction estimated...) thickness across the arterial wall. In this dissertation, I propose an image analysis scheme to delineate spatial patterns of EL such as changes in its thickness across the arterial wall. Key features of my scheme include: 1) a Radon Transform based...
Frey, G.A.; Twardochleb, C.Z.
1998-01-13
Past airfoil configurations have been used to improve aerodynamic performance and engine efficiencies. The present airfoil configuration further increases component life and reduces maintenance by reducing internal stress within the airfoil itself. The airfoil includes a chord and a span. Each of the chord and the span has a bow being summed to form a generally ``C`` configuration of the airfoil. The generally ``C`` configuration includes a compound bow in which internal stresses resulting from a thermal temperature gradient are reduced. The structural configuration reduces internal stresses resulting from thermal expansion. 6 figs.
Frey, Gary A. (Poway, CA); Twardochleb, Christopher Z. (Alpine, CA)
1998-01-01
Past airfoil configurations have been used to improve aerodynamic performance and engine efficiencies. The present airfoil configuration further increases component life and reduces maintenance by reducing internal stress within the airfoil itself. The airfoil includes a chord and a span. Each of the chord and the span has a bow being summed to form a generally "C" configuration of the airfoil. The generally "C" configuration includes a compound bow in which internal stresses resulting from a thermal temperature gradient are reduced. The structural configuration reduces internal stresses resulting from thermal expansion.
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Data Modeling and Theory Construction
Jan de Leeuw
2011-01-01
MODELING AND THEORY CONSTRUCTION F. Suppe. The Structure ofMODELING AND THEORY CONSTRUCTION JAN DE LEEUW This paper wasMODELING AND THEORY CONSTRUCTION F????? 1. The Scientist
Bayesian Nonparametric Methods for Protein Structure Prediction
Lennox, Kristin Patricia
2011-10-21
. We use our method to address the bioinformatics question of what distributions should be used when sampling to generate new candidate models for a protein?s structure, a matter of considerable interest to the structure prediction community. Recall... structure predictions by incorporating information about closely related ?template? protein structures into searches of protein conformation space. This is accomplished by generating density estimates on conformation space via various simpli- fications...
A structured approach for the engineering of biochemical network
Breitling, Rainer
. Keywords: systems biology; biochemical networks; modelling; signal transduction; Petri nets; ordinaryA structured approach for the engineering of biochemical network models, illustrated for signalling; Received (in revised form): 2nd May 2008 Abstract Quantitative models of biochemical networks (signal
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Stormwater Control Structures Stormwater Control Structures Stormwater control structures are engineered to control run-on and runoff water from suspected contaminated sites....
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Structural Health Monitoring Engineering Institute Structural Health Monitoring Structural Health Monitoring is the process of implementing a damage detection strategy for...
Pellegrino, Sergio
#12;#12;JOURNAL OF THE INTERNATIONAL ASSOCIATION FOR SHELL AND SPATIAL STRUCTURES: IASS 151 EXPANDABLE "BLOB" STRUCTURES F. JENSEN AND S. PELLEGRINO Department of Engineering, University of Cambridge and Spatial Structures From Models to Realization, held in September 2004 in Montpellier, France. SUMMARY
Kinematics Algorithms for Tensegrity Structures
Burt, Steven James
2013-01-01
Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Journal of Space Structures, 18(4):209–223, 2003. [27] Hoangfinding of tensegrity structures. Computers and Structures,
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Current Collaborations Past Collaborations NSEC Engineering Institute Structural Health Monitoring Engineering Institute Structural Health Monitoring- Statistical Pattern...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Current Collaborations Past Collaborations NSEC Engineering Institute Structural Health Monitoring Engineering Institute Structural Health Monitoring- Methodology Contact...
Detecting Anomalous Structures by Convolutional Sparse Models
Wohlberg, Brendt
.carrera}@polimi.it Alessandro Foi Department of Signal Processing Tampere University of Technology Tampere, Finland alessandro
Modeling the structure of collective intelligence
Dong, Wen, Ph.D. Massachusetts Institute of Technology
2010-01-01
The human problem solution process has attracted an increasing amount of interest among educators, managers, computer scientists and others. However, the discussion of the subject has suffered from the lack of stochastic ...
Structured estimation for the nonparametric Cox model
Bradic, J; Song, R
2015-01-01
2007), Sparsity oracle inequalities for the Lasso, Electron.Q. (2012), Hoefding’s inequality for super- martingales,Lemler, S. (2012), Oracle inequalities for the Lasso for the
Learning Bayesian Network Model Structure Dimitris Margaritis
, Microsoft Research, the USENIX Scholars Program, DARPA contract F30602-98-2-0107, and DoD MURI contract F
Optimized Null Model for Protein Structure Networks
Milenkovic, Tijana; Filippis, Ioannis; Lappe, Michael; Przulj, Natasa
2009-01-01
play a key role in protein folding. Phys Rev E Stat Nonlinstages in non-two-state protein folding. J Mol Biol 357(5):determinants of protein folding. PNAS 12. Soyer A, Chomilier
A computer model to compare greenhouse structures
Chiou, Jiun-Shian
1989-01-01
systems include pad alone, water distribution system, sumps, pumps, and plumbing kit. 7. Heating system: The two typical heating systems are either central or unit. The fuel can be either gas or oil. (1). Part one lists the prices of central heating... 36 48 24 $88 $114 $228 $32 36 48 $103 (3). Fan Jets Tube size (inch) HP Price Motorized Price shutter (4). Plastic tubes 18 24 30 1/4 420 18lbs 1/3 534 23lbs 1/2 622 33lbs Tube size (inch) 12 18 24 30 166 176 194 Price (ft...
Electronic Structure Modeling of Electrochemical Reactions at...
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Research Org: Energy Frontier Research Centers (EFRC); Nanostructures for Electrical Energy Storage (NEES) Sponsoring Org: USDOE SC Office of Basic Energy Sciences (SC-22)...
Coastal Structures Modeling Complex | Open Energy Information
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Electronic Structure Modeling of Electrochemical Reactions at
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(ROMs) for the prediction of the response of structures with embedded piezoelectric actuators. The ROMs, NASTRAN is adopted here. Notwithstanding the popularity of piezoelectric materials in structural dynamics related applications such as structural health monitoring and energy harvesting, not all commercial finite