Dissertations / Theses: 'Computer simulation studies'

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Oganov, Artem Romaevich. "Computer simulation studies of minerals." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271656.

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Boardman, Richard P. "Computer simulation studies of magnetic nanostructures." Thesis, University of Southampton, 2005. https://eprints.soton.ac.uk/45942/.

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Scientific and economic interest has recently turned to smaller and smaller magnetic structures which can be used in hard disk drives, magnetoresistive random access memory (MRAM), and other novel devices. For nanomagnets the geometric shape of the object becomes more important than other factors such as magnetocrystalline anisotropy . the smaller the object, the more strongly the shape anisotropy affects the hysteresis loop. We investigate the micromagnetic behaviour of ferromagnetic samples of various geometries using numerical methods. Finite differences and finite elements are used to solve the Landau-Lifshitz-Gilbert and Brown's equations in three dimensions. Simulations of basic geometric primitives such as cylinders and spheres of sub-micron size orders provide hysteresis loops of the average magnetisation, and additionally our computations allow the study of the microscopic configuration of the magnetisation. We show different mechanisms of vortex penetration for these geometries, and investigate part-spherical geometries whose magnetisation pattern demonstrates qualities of other primitives. Developing this further, we calculate the hysteresis loops for a droplet shape - a part-sphere capped with a half-ellipsoid. This resembles the shapes formed by some chemical self-assembly methods, a low-cost and efficient way of creating a commercially viable product. When examining the magnetic microstructure of this geometry we find different types of vortex behaviour, and reveal the dependence of this on the physical characteristics of the droplet. We also examine the hysteresis loops and magnetic structures of other geometries formed through the self-assembly method such as antidots:honeycomb-like arrays of spherical holes in a thin film. We show magnetisation patterns and comparison between experimental and computed magnetic force microscopy (MFM) measurements.

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Whatling, Shaun Gary. "Computer simulation studies of liquid crystals." Thesis, University of Southampton, 1997. https://eprints.soton.ac.uk/421720/.

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Vettorel, Thomas. "Polymer crystallization studies by computer simulation." Université Louis Pasteur (Strasbourg) (1971-2008), 2005. https://publication-theses.unistra.fr/public/theses_doctorat/2005/VETTOREL_Thomas_2005.pdf.

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Les polymères semi-cristallins sont des systèmes d'un grand intérêt industriel de par leur très nombreuses applications, et constituent également un riche sujet d'étude du fait de la complexité des structures formées au cours de la cristallisation, ainsi que des mécanismes à l'œuvre lors de celle-ci. Nous avons étudié la cristallisation des polymères par simulation numérique de plusieurs façons différentes : des simulations détaillées à l'échelle atomique nous ont permis de reproduire la structure cristalline de chaînes courtes d'alcanes à basse température, dont la simulation lors d'un réchauffement permet de retrouver une phase transitoire bien caractérisée expérimentalement. Le même modèle a été utilisé pour simuler le processus de cristallisation à partir du fondu au cours d'un refroidissement; ce type de simulations réaliste ne permet pas de reproduire des structures cristallines en un temps de simulation restreint. Afin de pouvoir reproduire efficacement des structures semi-cristallines aux caractéristiques réalistes, nous avons utilisé un autre type de simulations numériques nous permettant de considérer des échelles de longueur et de temps plus importantes : ce modèle coarse-grained a permis d'étudier le phénomène de cristallisation en détail, à l'aide de différents paramètres d'ordre caractérisant le cristal et son évolution au cours du temps. Nous avons aussi procédé à une étude détaillée des facteurs de structure du fondu de polymères à haute température de manière à déterminer quelle est l'influence de la structure du liquide sur la formation du cristal. Ces différentes études permettent une meilleure compréhension de l'influence sur le phénomène de cristallisation des différents paramètres utilisés dans la définition des modèles de simulation numérique
Semi-crystalline polymers are of great interest for industrial purposes, and the complex structures they involve as well as the mechanisms leading to the formation of crystals make their study very challenging. We investigated polymer crystallization by computer simulation via different methods: An atomisticly detailed model was used to reproduce the crystalline structure of short alkanes at low temperature, and continuous heating simulations gave rise to a transient phase that is well characterized in experiments. The same realistic model was used to simulate continuous cooling of the melt, but could not yield crystalline structures in a limited simulation time. In order to reproduce efficiently the characteristic features of semi-crystalline polymers, we used another simulation model which addresses larger length and time scales: This coarse-grained model allowed us to study the crystallization phenomenon in detail with several order parameters to characterize the crystal and its time evolution. The detailed study of the structure factors of the high-temperature melt has also been investigated so as to determine the influence of the liquid phase structure on crystal formation. These different studies yield a better understanding of the influence on crystallization of the various parameters entering the definitions of the simulation models

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Badcoe, Ian Geoffrey. "Computer studies of protein folding." Thesis, University of Bristol, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385585.

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La, Rocca Paolo. "Computer simulation studies of membrane active peptides." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299050.

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丘熙寧 and Hei-ling Danny Yau. "Computer simulation studies of hard sphere mixtures." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B3123544X.

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Wang, Weiwei. "Computer simulation studies of complex magnetic materials." Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/386147/.

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With the development of both computing power and software engineering, computer simulation of the micromagnetic model or atomistic spin model, has become an important tool for studying a wide range of different complex phenomena in magnetic materials. Meanwhile, the rapid improvement of advanced measurement techniques has allowed the probing of ultrafast magnetization dynamics, as well as the magnetic phenomena involving charge current, heat and light. The simulation of magnetism is now moving towards a multiphysics method. Therefore, fast, user-friendly, and extensible codes with accurate algorithms are helpful in understanding the physics and designing novel magnetic devices on the nanoscale. In the preparation of this thesis we have developed Fidimag, which is a Python/C simulation tool supporting both micromagnetic and atomistic spin models. The software has also been extended to support the Landau-Lifshitz-Baryakhtar (LLBar) equation. Using Fidimag, we have performed simulations to study the domain-wall motion and spin-wave decay with the LLBar equation. We also explain the exchange damping in the LLBar equation as the phenomenological nonlocal damping by linking it to spin pumping, therefore, LLBar equation can be considered as a phenomenological equation of the nonlocal damping. We studied magnon-induced domain-wall motion in the presence of Dzyaloshinskii-Moriya interaction (DMI) numerically and theoretically. We find that the presence of DMI and easy-plane anisotropy can drive the domain wall very effectively and that the domain-wall velocity depends on the sign of DMI constant. While the negative velocity is considered as a result of angular momentum conservation, we attribute this fast domain-wall motion to linear momentum transfer between magnons and the domain wall. By numerically solving the Landau-Lifshitz-Gilbert equation with a classical spin model on a two-dimensional system, we show that both magnetic skyrmions and skyrmion lattices can be moved with microwave magnetic fields. The mechanism is enabled by breaking the axial symmetry of the skyrmion with a static in-plane external field.

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Yau, Hei-ling Danny. "Computer simulation studies of hard sphere mixtures /." Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19669653.

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Harous, Saad. "Studies in distributed simulation." Case Western Reserve University School of Graduate Studies / OhioLINK, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=case1059575607.

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El, Azhar Fouad. "Phase diagrams of colloidal dispersions :computer simulation studies." Doctoral thesis, Universite Libre de Bruxelles, 2002. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211452.

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Dirikolu, Mehmet Husnu. "Computer aided simulation and experimental studies on machining." Thesis, University of Leeds, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.436244.

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Ilett, Douglas John. "Computer simulation studies of oxide and oxyhalide catalysts." Thesis, University of Surrey, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240008.

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Caves, L. S. D. "Computer simulation studies of native and modified insulins." Thesis, University of York, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234931.

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Zhu, Jian. "Multiscale computer simulation studies of entangled branched polymers." Thesis, University of Reading, 2017. http://centaur.reading.ac.uk/71796/.

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In this thesis, we investigate two problems of entangled branched polymers, i.e., the numerical solutions of the arm-retraction problem for well-entangled star arms and the relaxation behaviours of branched polymers with different architectures. For the first problem, the arm retraction dynamics is studied using both the onedimensional Rouse chain model and the slip-spring model by an advanced numerical method for the first-passage time problems, namely the forward flux sampling (FFS) method. In the one-dimensional Rouse chain model, we measured the first-passage time that the arm free end extends to a distance away from the origin, showing that the mean first-passage time is getting shorter if the Rouse chain is represented by more beads. The simulation results validate the prediction of an asymptotic solution for the multi-dimensional first-passage problem, which suggests the arm retraction time is much shorter than the prediction of the Milner-McLeish theory without constraint release. Then, we implement the FFS method to the slip-spring model and get the relaxation spectra for different arm lengths, ranging from mildly entangled to well-entangled star arms. We also proposed an algorithm to extract the dynamic observables, i.e., the end-to-end vector and stress relaxation functions, from the FFS simulation results. For the second problem, we conduct a series of molecular dynamics (MD) simulations using high-performance GPU methods on the mildly entangled branched polymers of different architectures, including 3-arm symmetric and asymmetric stars, and H-shaped polymers. The slip-spring model, whose parameters are carefully calibrated according to the MD results of linear chains, is also implemented to predict the relaxation behaviours of the branched polymers. We present a detailed analysis of the arm end-to-end vector relaxation functions and the monomer mean-squared displacements. By comparing the MD and slipspring model simulation results, we propose a slip-link “hopping” mechanism, which accounts for the behaviour that the entanglements can pass through the branch point when the third arm is disentangled.

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ENGELBRECHT, LEON DE VILLIERS. "Computer simulation studies of micro-heterogeneous liquid mixtures." Doctoral thesis, Università degli Studi di Cagliari, 2021. http://hdl.handle.net/11584/314050.

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Liquid mixtures are part of our everyday lives and are important in numerous chemical research and industrial applications. While often apparently featureless, uniform and uninteresting, kept in bottles and containers in the chemical laboratory, their molecular-level structure and physical properties can be completely the opposite, and are continually attracting scientific interest. Strong repulsive and attractive interactions between the molecules can create most intriguing local arrangements, molecular aggregates and complexes, whose spatial organisation is often difficult to characterise, or rationalise. Moreover, the same liquid components can behave completely differently depending on the mixing ratio, strongly affecting macroscopic properties, e.g. mass density, viscosity or melting/boiling points. To gain insight into the complex world of binary liquid mixtures, deep eutectic solvents and ionic liquids, a combination of experimental and theoretical, or computational, studies is necessary. In this thesis, the focus is on understanding how the microscopic molecular organization in organic solvent mixtures affects the physico-chemical and solvating properties. While in all of the presented studies the systems are investigated both experimentally and computationally, the main focus of my thesis is on computational modelling, primarily based on molecular mechanics. In this approach, the system of interest is modelled by interacting particles representing either single atoms of groups of atoms, and their interactions and movements are described by classical mechanics. This approximate method allows for the modelling of large molecular systems, e.g. liquid mixtures with structural heterogeneities on the nanometer length scale and microsecond time scale. Specifically, my work has been devoted to the following problems: (1) Explaining how large anions in mixed liquid solvents can be apparently preferentially solvated by the less polar components, described in Chapter 3. (2) Explaining excess thermodynamics properties for relatively simple organic solvent liquid mixtures, described in Chapter 4, and extending the investigation approach to more complex “pseudo-binary” mixtures of DES with water or methanol, where it has not been applied before, described in Chapter 6. (3) Developing coarse-grained models of charged liquid solvent, to be able to verify the long-range ordering effects connected to solvent micro-segregation, described in Chapter 5. The fundamental concepts and background are provided in Chapter 1 & 2.

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Beyer, Frank [Verfasser]. "Computer simulation studies of vector spin glasses / Frank Beyer." Mainz : Universitätsbibliothek Mainz, 2012. http://d-nb.info/1029907552/34.

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Ma, X. "Computer simulation studies of automatic and flexible assembly systems." Thesis, University of Bradford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376688.

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Mahankali, Uma. "Computer Simulation Studies of CLC Chloride Channels and Transporters." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1157115905.

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Song, Hyun Deok. "Computer Simulation Studies of Ion Channels at High Temperatures." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1328890332.

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Tschaufeser, Petra. "Computer simulation studies of zeolites and related microporous materials." Thesis, University of Bath, 1992. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306781.

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Chaba, Pudumo Jimmy. "Computer simulation studies of fastion yttria-stabilised cubic zirconia." Thesis, University of Limpopo, 1999. http://hdl.handle.net/10386/2076.

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Stern, Abraham C. "Computer Simulation of Metal-Organic Materials." Scholar Commons, 2010. http://scholarcommons.usf.edu/etd/3584.

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Computer simulations of metal-organic frameworks are conducted to both investigate the mechanism of hydrogen sorption and to elucidate a detailed, molecular-level understanding of the physical interactions that can lead to successful material design strategies. To this end, important intermolecular interactions are identified and individually parameterized to yield a highly accurate representation of the potential energy landscape. Polarization, one such interaction found to play a significant role in H 2 sorption, is included explicitly for the first time in simulations of metal-organic frameworks. Permanent electrostatics are usually accounted for by means of an approximate fit to model compounds. The application of this method to simulations involving metal-organic frameworks introduces several substantial problems that are characterized in this work. To circumvent this, a method is developed and tested in which atomic point partial charges are computed more directly, fit to the fully periodic electrostatic potential. In this manner, long-range electrostatics are explicitly accounted for via Ewald summation. Grand canonical Monte Carlo simulations are conducted employing the force field parameterization developed here. Several of the major findings of this work are: Polarization is found to play a critical role in determining the overall structure of H 2 sorbed in metal-organic frameworks, although not always the determining factor in uptake. The parameterization of atomic point charges by means of a fit to the periodic electrostatic potential is a robust, efficient method and consistently results in a reliable description of Coulombic interactions without introducing ambiguity associated with other procedures. After careful development of both hydrogen and framework potential energy functions, quantitatively accurate results have been obtained. Such predictive accuracy will aid greatly in the rational, iterative design cycle between experimental and theoretical groups that are attempting to design metal-organic frameworks for a variety of purposes, including H 2 sorption and CO2 sequestration.

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Van, Belle Daniel. "Computer studies of electronic polarization effects in biological systems." Doctoral thesis, Universite Libre de Bruxelles, 1992. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212930.

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Collins, David R. "Computer simulation and neutron scattering studies of layer silicate materials." Thesis, Keele University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292741.

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Du, Zhimei. "Computer simulation and theoretical studies of hydrocarbon adsorption in silicalite." Thesis, London South Bank University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342841.

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Palin, Erika Jane. "Computer simulation studies of cation ordering in phyllosilicates and amphiboles." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.615902.

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Xia, Hong. "Library CD-ROM LAN Performance and Patron Use: a Computer Simulation Model." Thesis, University of North Texas, 1996. https://digital.library.unt.edu/ark:/67531/metadc279383/.

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In this study, a computer simulation model for library CD-ROM LAN systems was created. Using this model, the system optimization problems were examined. The simulation model imitated the process of the actual decision variables changing their values and generated the corresponding results. Under a certain system environment, if the values of decision variables are changing, the system performances are getting changed also. This study investigated these relationships with the created model. The system users' interarrival time, service time, and other relevant data were collected on randomly selected days in a university library. For data collection, both of the observation and the system automatic metering software were used. According to the collected data, a discrete events simulation model was created with GPSS/H. The simulation model was proven valid and accurate by a pilot test and by the calculation with queuing theory. Statistical tests were used for data comparison and analysis. In addition, animation technique was used to show the simulation process by using Proof Animation. By this technique, the simulation process was monitored on the screen.

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Sullivan, Daniel Thomas. "Computer simulation studies of two-dimensional beamforming for linear arrays using a parallel computer system." Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/26426.

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Approved for public release; distribution is unlimited
Computer simulation results of a parallel system conducting beamforming for a linear hydrophone array are presented. These studies were performed to determine the best mapping and partitioning of a sequential beamformer program onto a parallel system. Different partition designs and programming methodologies were examined, as well as latencies caused by inter-processor communications. Results of these simulation studies demonstrate that linear scalability in performance is possible by programming with host-node methodology and utilizing efficient inter-processor communications.

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Tomlinson, Simon Michael. "Computer simulation studies of rock-salt structured binary transition metal oxides." Thesis, University College London (University of London), 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264941.

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Lui, Lai Kwan Yvonne. "Experimental and computer simulation studies of clathrate hydrates and porous materials." Thesis, King's College London (University of London), 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429579.

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Troitzsch, Raphael Zacharias. "Computer simulation studies of the aqueous solvation of ions and peptides." Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/14581.

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Molecular Dynamics simulations have been carried out on systems of increasing complexity and biological relevance, in particular aqueous solutions of ions and peptides, in order to establish the local association patterns of solute and solvent molecules, as well as the structure formed by the solvent around the solvated ions/molecules. To account for quantum effects not readily observed in classical MD, ab initio Car-Parrinello simulations have been carried out. To establish a connection with experimental findings and thus underpin simulation results, techniques were developed to compute and refine structure factors from simulations to compare with experimental scattering data. Based on these findings, water models’ qualities as a solvent have been evaluated, resulting in a firm disinclination to the TIP3P model. Further tools to quantify local structure have been developed and implemented, including the development of an order parameter to gauge the four-fold co-ordination of water in pure and mixed form as a function of a parameter of interest, here temperature, and special density calculations to visualise the local neighbourhood of molecules. A key objective was to elucidate previously disputed areas in the fundamental findings surrounding the systems in question. This has been achieved in the case of aqueous solution of L-proline with regards to the formation of macromolecular association and the formation of intermediate structure, as well as the question of close ion contact and local ion solvation structure and co-ordination of aqueous NaCl. Beyond that, new insight into the mechanism of exchange of members of the first solvation shell of Na, as well as into the molecular mechanism based on the hydrogen bonding pattern of inter-proline and proline-water association as a facilitator to the cryoprotectant nature of proline was gained. Finally, the nature of the helix formed by the gp41 polypeptide in water was expounded.

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Huntington, James E. "Computer simulation studies of nuclear reactor fuel and related uranium phases." Thesis, Keele University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384936.

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Tang, Dong. "Studies of computer aided image interpretaion in high resolution electron microscopy." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240064.

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Corry, Ben Alexander, and ben corry@anu edu au. "Simulation Studies of Biological Ion Channels." The Australian National University. Research School of Physical Sciences and Engineering, 2003. http://thesis.anu.edu.au./public/adt-ANU20030423.162927.

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Biological ion channels are responsible for, and regulate the communication system in the body. In this thesis I develop, test and apply theoretical models of ion channels, that can relate their structure to their functional properties. Brownian dynamics simulations are introduced, in which the motions of individual ions are simulated as they move through the channel and in baths attached to each end. The techniques for setting boundary conditions which maintain ion concentrations in the baths and provide a driving potential are tested. Provided the bath size is large enough, all boundary conditions studied yield the same results. ¶ Continuum theories of electrolytes have previously been used to study ion permeation. However, I show that these continuum models do not accurately reproduce the physics taking place inside ion channels by directly comparing the results of both equilibrium Poisson-Boltzmann theory, and non-equilibrium Poisson-Nernst-Planck theory to simulations. In both cases spurious shielding effects are found to cancel out forces that play an important role in ion permeation. In particular, the `reaction field' created by the ion entering the narrow channel is underestimated. Attempts to correct these problems by adding extra force terms to account for this reaction field also fail. ¶ A model of the L-type calcium channel is presented and studied using Brownian dynamics simulations and electrostatic calculations. The mechanisms of permeation and selectivity are explained as the result of simple electrostatic interactions between ions and the fixed charges in the protein. The complex conductance properties of the channel, including the current-voltage and current-concentration relationships, the anomalous mole fraction behaviour between sodium and calcium ions, the attenuation of calcium currents by monovalent ions and the effects of mutating glutamate residues, are all reproduced. ¶ Finally, the simulation and electrostatic calculation methods are used to study the gramicidin A channel. It is found that the continuum electrostatic calculations break down in this narrow channel, as the concept of applying a uniform dielectric constant is not accurate in this situation. Thus, the permeation properties of the channel are examined using Brownian dynamics simulations without electrostatic calculations. Future applications and improvements of the Brownian dynamics simulation technique are also described.

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Zhang, Feiwu. "Computer simulation studies of iron-bearing phases in the Earth's deep interior /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17712.

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Bennun, Serrano Sandra Viviana. "COMPUTER SIMULATION STUDIES FOR THE PRODUCTION OF 7-TETRADECENE BY REACTIVE DISTILLATION." MSSTATE, 2003. http://sun.library.msstate.edu/ETD-db/theses/available/etd-07222003-155936/.

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The production of 7-tetradecene was examined. Properties for this compound were estimated using group contribution methods and compared to experimental data. Process simulation was used as a tool to identify competitive processing strategies. For reactive distillation, three different models were compared to determine the model complexity needed to describe the process: Model A, with the assumption of physical and chemical equilibrium; Model B, with kinetics described by a second order reaction and physical equilibrium; and Model C, a non-equilibrium stage model that accounts for mass transfer. A conceptual design was obtained with Model B and was checked with Model C, which described the process more accurately but was more difficult to converge. Since, Model A was easier to converge, it was used to predict process conversions at different pressures. Predictions favor working at 1 bar, due to the lower heat duty and the minimum stages required.

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Gunnerson, Kim Noreen. "Computer simulation studies of molecular interactions by application of classical molecular dynamics /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/8668.

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Perry, C. "Studies by computer simulation of visual detection and discrimination of astronomical objects." Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/37816.

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Sayle, Thi Xuan Tran. "Computer simulation studies of the metal-oxide support in automobile exhaust catalysis." Thesis, University of Bath, 1993. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336167.

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Bajpai, Anil Kumar. "Computer simulation of quality costs and benefits : a system dynamics modelling approach." Thesis, University of Nottingham, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278347.

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Wang, Xu. "Freeway Exit Ramp Traffic Flow Research Based on Computer Simulation." Scholar Commons, 2007. https://scholarcommons.usf.edu/etd/554.

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Interstate highways are one of the most important components of the transportation infrastructure in America. Freeway ramps play an important role in the whole interstate transportation system. This paper researches the traffic flow characteristics of four typical exit ramps in USA, which are tapered one-lane exit, tapered two-lane exit, parallel one-lane exit and parallel two-lane exit. Computer simulation software, such as CORSIM and HCS are applied as the main tools in this research. ANOVA and Tukey are used for statistical purpose. It compares the maximum capacity, average running speed and the total lane change number of those four exit ramps. It is found that no matter in terms of traffic discharging rate or total lane charging number; the tapered two-lane exit has the best operational performance. Tapered one-lane exit ramp has the least capacity. Parallel one-lane exit and parallel two-lane exit have very limited traffic operational difference in terms of capacity and running speed. It is recommended that parallel two-lane exit ramp should not be designed along the freeway if the right of way along arterial road is enough. It is observed from the simulation data that the grade of freeway, truck percentage, restricted to the truck use of certain lane(s) and the location of exit sign have significant impact on the running speed and total lane change number. An uphill can decrease the running speed dramatically while more truck brings more lane change, causing safety concerns. It is found that when trucks are restricted to the right two most lane, there will be less lane change number comparing with trucks are not restricted. Location of exit sign operates well at the distance between 4000 ft to 5000 ft. does have a significant impact on the operational speed and total lane change number before, within or after functional area of an exit, based on the data analysis of simulation runs.

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Ho, Wai Man. "Case studies in computer experiments, applications of uniform design and modern modeling techniques." HKBU Institutional Repository, 2001. http://repository.hkbu.edu.hk/etd_ra/290.

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Kulkarni, Shrinivas Bhalachandra. "The simulation studies on a behaviour based trust routing protocol for ad hoc networks." Diss., Online access via UMI:, 2006.

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Lewin, Mark James Chemistry Faculty of Science UNSW. "Instrument development and computational studies of time-of-flight mass spectrometers." Awarded by:University of New South Wales, 2006. http://handle.unsw.edu.au/1959.4/39745.

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A computer program to simulate peak shapes from time-of-flight (TOF) mass spectrometers has been developed and significantly improved from a previous, unpublished version. This program can accurately simulate both TOF and orthogonal acceleration TOF mass analyser peak shapes, with contributions from initial ion properties, instrument geometry, and other factors including high voltage ripple and detector response. Grid effects have also been included, and simulations for two mass spectrometers are compared to actual recorded spectra. The dispersive effect on ion trajectories of parallel wires and grids has been computationally studied and a model derived for each case. The model is based on the effect wire geometry has on the intrinsic focussing effect of the grid. The models for parallel wires and rectangular grids have been coded into the simulation program described above, and the effect of grids on peak shapes in TOF mass spectrometers has been studied. Good correlation between simulated and actual peak shapes for rectangular grids was obtained for grids in different rotational orientations. A pulsed lens has been developed to reduce the velocity spread of ions in matrix assisted laser desorption/ionisation (MALDI) ion sources, with the aim to increase sensitivity in orthogonal acceleration TOF mass analysers. The system gave an increase in sensitivity of approximately five times over a range of masses, however instrument resolving power was reduced. A rotating sample stage was developed for MALDI mass spectrometers which offers the potential of high sample density, high positional accuracy and repeatability, and low seek times. The system involves reading the position of a disk mounted with MALDI sample spots and timing the laser pulse to coincide with spot availability at an aperture. The system was successfully used to perform mass calibration by using a calibrant sample located on a separate spot to the analyte. Mass resolved disk imaging was also performed over a disk radius using inks. The mass resolved image compared well to the optical image.

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46

Hosseinian, S. H. "Improvements in simulation methods for power system harmonic and transient studies." Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318542.

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Lundborg, Magnus. "Computer-Assisted Carbohydrate Structural Studies and Drug Discovery." Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-56411.

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Carbohydrates are abundant in nature and have functions ranging from energy storage to acting as structural components. Analysis of carbohydrate structures is important and can be used for, for instance, clinical diagnosis of diseases as well as in bacterial studies. The complexity of glycans makes it difficult to determine their structures. NMR spectroscopy is an advanced method that can be used to examine carbohydrates at the atomic level, but full assignments of the signals require much work. Reliable automation of this process would be of great help. Herein studies of Escherichia coli O-antigen polysaccharides are presented, both a structure determination by NMR and also research on glycosyltransferases which assemble the polysaccharides. The computer program CASPER has been improved to assist in carbohydrate studies and in the long run make it possible to automatically determine structures based only on NMR data. Detailed computer studies of glycans can shed light on their interactions with proteins and help find inhibitors to prevent unwanted binding. The WaaG glycosyltransferase is important for the formation of E. coli lipopolysaccharides. Molecular docking analyses of structures confirmed to bind this enzyme have provided information on how inhibitors could be composed. Noroviruses cause gastroenteritis, such as the winter vomiting disease, after binding human histo-blood group antigens. In one of the projects, fragment-based docking, followed by molecular dynamics simulations and binding free energy calculations, was used to find competitive binders to the P domain of the capsid of the norovirus VA387. These novel structures have high affinity and are a very good starting point for developing drugs against noroviruses. The protein targets in these two projects are carbohydrate binding, but the techniques are general and can be applied to other research projects.
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Submitted. Paper 5: Manuscript. Paper 6. Manuscript.

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Didoszak, Jarema M. "Parametric studies of DDG-81 ship shock trial simulations." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Mar%5FDidoszak.pdf.

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Behrle, Charles D. "Computer simulation studies of multiple broadband target localization via frequency domain beamforming for planar arrays." Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/22976.

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Approved for public release; distribution is unlimited
Computer simulation studies of a frequency domain adaptive beamforming algorithm are presented. These simulation studies were conducted to determine the multiple broadband target localization capability and the full angular coverage capability of the algorithm. The algorithm was evaluated at several signal-to-noise ratios with varying sampling rates. The number of iterations that the adaptive algorithm took to reach a minimum estimation error was determined. Results of the simulation studies indicate that the algorithm can localize multiple broadband targets and has full angular coverage capability.
http://archive.org/details/computersimulati00behr
Lieutenant, United States Navy

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Winters, Desiree Marie. "Using Playable Case Studies to Influence Teen Girls' Self-Efficacy and Interest in Cybersecurity." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7558.

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Various factors dissuade women from the field of cybersecurity. Educational interventions are needed to mitigate the negative effects of stereotypes and low perceived self-efficacy and help girls gain interest in learning about cybersecurity. This thesis focuses on an intervention targeted to increase teenage girls' interest and self-efficacy in cybersecurity: the Cybermatics Playable Case Study. Findings from a mixed-methods study in which a focus group was conducted with 7 middle school girls, interviews were conducted with 2 high school girls, and pre- and post- simulation survey was collected from all 9 participants reveal tensions between enjoyment and frustration in the girls' experience with Cybermatics and their desire for both autonomy in completing tasks and the availability of help when needed. Almost all of the study participants indicated that their experience with the Playable Case Study made them more interested in cybersecurity and feel more confident in their ability to do well in a cybersecurity class, although the quantitative data revealed considerable complexity in the girls' perceptions of these constructs and significant lack of prior knowledge of cybersecurity. Quantitative survey data illustrates correlations between successful completion and enjoyment of the simulation, interest, and self-efficacy. Qualitative data from the focus group and 2 individual interviews shed light on what may be the simulation's greatest benefit: giving exposure to cybersecurity to teen girls in a way that is interesting and provides an accurate portrayal of the work of a security analyst.

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Dissertations / Theses on the topic 'Computer simulation studies'

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