The Experts below are selected from a list of 140418 Experts worldwide ranked by ideXlab platform
Qingyan Chen - One of the best experts on this subject based on the ideXlab platform.
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a markov chain model for predicting transient Particle Transport in enclosed environments
Building and Environment, 2015Co-Authors: Chun Chen, Wei Liu, Chaohsin Lin, Qingyan ChenAbstract:Obtaining information about Particle dispersion in a room is crucial in reducing the risk of infectious disease transmission among occupants. This study developed a Markov chain model for quickly obtaining the information on the basis of a steady-state flow field calculated by computational fluid dynamics. When solving the Particle Transport equations, the Markov chain model does not require iterations in each time step, and thus it can significantly reduce the computing cost. This study used two sets of experimental data for transient Particle Transport to validate the model. In general, the trends in the Particle concentration distributions predicted by the Markov chain model agreed reasonably well with the experimental data. This investigation also applied the model to the calculation of person-to-person Particle Transport in a ventilated room. The Markov chain model produced similar results to those of the Lagrangian and Eulerian models, while the speed of calculation increased by 8.0 and 6.3 times, respectively, in comparison to the latter two models.
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advanced turbulence models for predicting Particle Transport in enclosed environments
Building and Environment, 2012Co-Authors: Miao Wang, Chaohsin Lin, Qingyan ChenAbstract:Abstract Occupant health is related to Particle contaminants in enclosed environments, so it is important to study Particle Transport in spaces to quantify the rates and routes of potential disease transmission. In many cases, Particle contaminants in an enclosed space are generated from an unsteady source. This investigation used the experimental data from two steady-state cases as well as one transient Particle dispersion case in evaluating the performance of five (one steady and four transient) airflow models with the Eulerian and Lagrangian methods. The transient models obtained the mean flow and Particle information by averaging them over time. For the models tested in this study, the Eulerian method performed similarly for all five airflow models. The Lagrangian method predicted incorrect Particle concentrations with the Reynolds-Averaged Navier–Stokes (RANS) and Unsteady Reynolds-Averaged Navier–Stokes (URANS) methods, but did well with the Large Eddy Simulation (LES) and Detached Eddy Simulation (DES) models. For unsteady-state Particle dispersion, the LES or DES models, along with the Lagrangian method, showed the best performance among all the models tested.
Katharina Ribbeck - One of the best experts on this subject based on the ideXlab platform.
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an adsorption chromatography assay to probe bulk Particle Transport through hydrogels
Journal of Pharmaceutical Sciences, 2012Co-Authors: Ioana D Vladescu, Oliver Lieleg, S Jang, Katharina RibbeckAbstract:ABSTRACT: Biopolymer-based hydrogels such as mucus and the basal lamina play a key role in biology, where they control the exchange of material between different compartments. They also pose a barrier that needs to be overcome for successful drug delivery. Characterizing the permeability properties of such hydrogels is mandatory for the development of suitable drug delivery vectors and pharmaceutics. Here, we present an experimental method to measure bulk Particle Transport through hydrogels. We validate our assay by applying it to mucin hydrogels and show that the permeability properties of these mucin hydrogels can be modulated by polymer density and pH, in agreement with previous results obtained from single Particle tracking. The method we present here is easy to handle, inexpensive, and high-throughput compatible. It is also a suitable platform for the design and screening of drugs that aim at modifying the barrier properties of hydrogels. This system can also aid in the characterization and development of synthetic gels for a range of biomedical applications. © 2011 Wiley Periodicals, Inc. and the American Pharmacists Association.
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an adsorption chromatography assay to probe bulk Particle Transport through hydrogels
PMC, 2011Co-Authors: Ioana D Vladescu, Oliver Lieleg, S Jang, Katharina RibbeckAbstract:Biopolymer-based hydrogels such as mucus and the basal lamina play a key role in biology where they control the exchange of material between different compartments. They also pose a barrier that needs to be overcome for successful drug delivery. Characterizing the permeability properties of such hydrogels is mandatory for the development of suitable drug delivery vectors and pharmaceutics. Here, we present an experimental method to measure bulk Particle Transport through hydrogels. We validate our assay by applying it to mucin hydrogels and show that the permeability properties of these mucin hydrogels can be modulated by the polymer density and pH, in agreement with previous results obtained from single Particle tracking. The method we present here is easy to handle, inexpensive, and high-throughput compatible. It is also a suitable platform for the design and screening of drugs that aim at modifying the barrier properties of hydrogels. This system can also aid in the characterization and development of synthetic gels for a wide range of biomedical applications.
P Saracco - One of the best experts on this subject based on the ideXlab platform.
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evaluation of atomic electron binding energies for monte carlo Particle Transport
IEEE Transactions on Nuclear Science, 2011Co-Authors: M G Pia, Hee Seo, M Batic, M Begalli, Chan Hyeong Kim, L Quintieri, P SaraccoAbstract:A survey of atomic binding energies used by general purpose Monte Carlo systems is reported. Various compilations of these parameters have been evaluated; their accuracy is estimated with respect to experimental data. Their effects on physical quantities relevant to Monte Carlo Particle Transport are highlighted: X-ray fluorescence emission, electron and proton ionization cross sections, and Doppler broadening in Compton scattering. The effects due to different binding energies are quantified with respect to experimental data. Among the examined compilations, EADL is found in general a less suitable option to optimize simulation accuracy; other compilations exhibit distinctive capabilities in specific applications, although in general their effects on simulation accuracy are rather similar. The results of the analysis provide quantitative ground for the selection of binding energies to optimize the accuracy of Monte Carlo simulation in experimental use cases. Recommendations on software design dealing with these parameters and on the improvement of data libraries for Monte Carlo simulation are discussed.
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evaluation of atomic electron binding energies for monte carlo Particle Transport
arXiv: Computational Physics, 2011Co-Authors: M G Pia, Hee Seo, M Batic, M Begalli, Chan Hyeong Kim, L Quintieri, P SaraccoAbstract:A survey of atomic binding energies used by general purpose Monte Carlo systems is reported. Various compilations of these parameters have been evaluated; their accuracy is estimated with respect to experimental data. Their effects on physics quantities relevant to Monte Carlo Particle Transport are highlighted: X-ray fluorescence emission, electron and proton ionization cross sections, and Doppler broadening in Compton scattering. The effects due to different binding energies are quantified with respect to experimental data. The results of the analysis provide quantitative ground for the selection of binding energies to optimize the accuracy of Monte Carlo simulation in experimental use cases. Recommendations on software design dealing with these parameters and on the improvement of data libraries for Monte Carlo simulation are discussed.
Edward W Larsen - One of the best experts on this subject based on the ideXlab platform.
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non classical Particle Transport with angular dependent path length distributions i theory
Annals of Nuclear Energy, 2014Co-Authors: Richard Vasques, Edward W LarsenAbstract:Abstract This paper extends a recently introduced theory describing Particle Transport for random statistically homogeneous systems in which the distribution function p ( s ) for chord lengths between scattering centers is non-exponential. Here, we relax the previous assumption that p ( s ) does not depend on the direction of flight Ω ; this leads to a new generalized linear Boltzmann equation that includes angular-dependent cross sections, and to a new generalized diffusion equation that accounts for anisotropic behavior resulting from the statistics of the system.
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a generalized linear boltzmann equation for non classical Particle Transport
Journal of Quantitative Spectroscopy & Radiative Transfer, 2011Co-Authors: Edward W Larsen, Richard VasquesAbstract:This paper presents a derivation and initial study of a new generalized linear Boltzmann equation (GLBE), which describes Particle Transport for random statistically homogeneous systems in which the distribution function for chord lengths between scattering centers is non-exponential. Such problems have recently been proposed for the description of photon Transport in atmospheric clouds; this paper is a first attempt to develop a Boltzmann-like equation for these and other related applications.
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the atomic mix approximation for charged Particle Transport
Siam Journal on Applied Mathematics, 2007Co-Authors: Edward W Larsen, Liang LiangAbstract:The classic atomic mix approximation for Particle Transport in a stochastic spatial medium is accurate when the material chunks in the medium are small compared to a mean free path. In this paper, we show that for charged Particle Transport in a stochastic medium, the atomic mix approximation is accurate when the chunk sizes are small compared to a Transport mean free path. For charged Particle Transport, the Transport mean free path is generally several orders of magnitude larger than the mean free path. Therefore, the result obtained in this paper greatly extends the known range of applicability of the atomic mix approximation. Numerical results are given that validate the asymptotic theory, and an application of the theory to a practical problem in radiation oncology is discussed.
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Automated Weight Windows for Global Monte Carlo Particle Transport Calculations
Nuclear Science and Engineering, 2001Co-Authors: Marc A. Cooper, Edward W LarsenAbstract:A new method for efficiently solving global Monte Carlo Particle Transport problems is presented. (In these problems, flux information is desired across the entire system, not just at a small number of detector locations.) The method is based on the use of a weight window that distributes Monte Carlo Particles uniformly throughout the system. This (a) ensures that all subregions of the system are adequately sampled and (b) controls the Particle weights, even in subregions far from sources. The weight window is constructed from an approximate deterministic solution of the forward Transport problem. It is argued that a weight window based on the forward Transport solution is more appropriate for global problems than the more familiar concept of basing a weight window on an adjoint solution for source-detector problems. It is also shown that by using Monte Carlo-generated Eddington factors in deterministic solutions of the quasi-diffusion equation, one can inexpensively compute updated forward-based weight windows and obtain a more efficient global Monte Carlo calculation.
Xiang Gao - One of the best experts on this subject based on the ideXlab platform.
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numerical simulation of corona discharge and Particle Transport behavior with the Particle space charge effect
Journal of Aerosol Science, 2018Co-Authors: Chenghang Zheng, Xuefeng Zhang, Zhengda Yang, Chengsi Liang, Yishan Guo, Yi Wang, Xiang GaoAbstract:Abstract The corona discharge characteristics of an electrostatic precipitator are an important factor that affects Particle charging and collection. The electrical characteristics of a wire-plate electrostatic precipitator and the Particle Transport behavior were studied by considering the electrohydrodynamics (EHD) and the effect of Particle space charge through numerical simulation. Simulation results showed that the effect of Particle space charge intensifies in extremely small Particles, such as submicron Particles. This condition significantly influences electric field, ionic charge density, and current. The electric field intensity and ionic charge concentration significantly decreased. The reduction in the minimum field intensity between the electrodes decreased to 50%, and the lowest concentration of the ionic charge tended to 0 when the Particle size varied from 5 µm to 0.1 µm. When the applied voltage increased from 13 kV to 40 kV, the space charge ratio of the Particles larger than 2 µm was reduced to almost 0 but remained at a high level for the Particles less than 0.5 µm whose corresponding current was lower by 20% than that without Particle condition. The ionic wind in the electrostatic field also weakened because the movement of ions was restricted for corona suppression, leading to decreased corona current. Furthermore, the Particle Transport behavior was compared considering the effect of Particle space charge. Results indicated that the difference between the two conditions increased from 1.3% to 47.4% with decreasing Particle size from 5 µm to 0.07 µm. In addition, the Particle migration velocity of the 0.1 µm Particles increased by 9.8%, from 0.2 to 0.1 µm, even if the drag force was reduced when considering the Particle space charge. A modified I–V equation was provided, with fitting coefficient of 0.996, and is thus worthy of reference in practical application.
