Дисертації з теми "Diffusion geometry"
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Habermann, Karen. "Geometry of sub-Riemannian diffusion processes." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/271855.
Повний текст джерелаKearney, Dominic. "Turbulent diffusion in channels of complex geometry." Thesis, Loughborough University, 2000. https://dspace.lboro.ac.uk/2134/7275.
Повний текст джерелаDE, PONTI NICOLÒ. "Optimal transport: entropic regularizations, geometry and diffusion PDEs." Doctoral thesis, Università degli studi di Pavia, 2019. http://hdl.handle.net/11571/1292130.
Повний текст джерелаGlaser, Jens, Masashi Degawa, Inka Lauter, Rudolf Merkel, and Klaus Kroy. "Tube geometry and brownian dynamics in semiflexible polymer networks." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-188856.
Повний текст джерелаGlaser, Jens, Masashi Degawa, Inka Lauter, Rudolf Merkel, and Klaus Kroy. "Tube geometry and brownian dynamics in semiflexible polymer networks." Diffusion fundamentals 11 (2009) 7, S. 1-2, 2009. https://ul.qucosa.de/id/qucosa%3A13927.
Повний текст джерелаCai, Li-Dong. "Scale-based surface understanding using diffusion smoothing." Thesis, University of Edinburgh, 1991. http://hdl.handle.net/1842/6587.
Повний текст джерелаLyytik�inen, Katja Johanna. "Control of complex structural geometry in optical fibre drawing." University of Sydney. School of Physics and the Optical Fibre Technology Centre, 2004. http://hdl.handle.net/2123/597.
Повний текст джерелаLyytikäinen, Katja Johanna. "Control of complex structural geometry in optical fibre drawing." Thesis, The University of Sydney, 2004. http://hdl.handle.net/2123/597.
Повний текст джерелаChaudry, Qasim Ali. "Numerical Approximation of Reaction and Diffusion Systems in Complex Cell Geometry." Licentiate thesis, KTH, Numerical Analysis, NA, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-12099.
Повний текст джерелаThe mathematical modelling of the reaction and diffusion mechanism of lipophilic toxic compounds in the mammalian cell is a challenging task because of its considerable complexity and variation in the architecture of the cell. The heterogeneity of the cell regarding the enzyme distribution participating in the bio-transformation, makes the modelling even more difficult. In order to reduce the complexity of the model, and to make it less computationally expensive and numerically treatable, Homogenization techniques have been used. The resulting complex system of Partial Differential Equations (PDEs), generated from the model in 2-dimensional axi-symmetric setting is implemented in Comsol Multiphysics. The numerical results obtained from the model show a nice agreement with the in vitro cell experimental results. The model can be extended to more complex reaction systems and also to 3-dimensional space. For the reduction of complexity and computational cost, we have implemented a model of mixed PDEs and Ordinary Differential Equations (ODEs). We call this model as Non-Standard Compartment Model. Then the model is further reduced to a system of ODEs only, which is a Standard Compartment Model. The numerical results of the PDE Model have been qualitatively verified by using the Compartment Modeling approach. The quantitative analysis of the results of the Compartment Model shows that it cannot fully capture the features of metabolic system considered in general. Hence we need a more sophisticated model using PDEs for our homogenized cell model.
Computational Modelling of the Mammalian Cell and Membrane Protein Enzymology
Chaudhry, Qasim Ali. "Numerical Approximation of Reaction and Diffusion Systems in Complex Cell Geometry." Licentiate thesis, KTH, Numerisk analys, NA, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-12099.
Повний текст джерелаComputational Modelling of the Mammalian Cell and Membrane Protein Enzymology
Gilbert, Stephen Henry. "An investigation of ventricular geometry and architecture using diffusion tensor MRI." Thesis, University of Leeds, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.493550.
Повний текст джерелаSengupta, Anandraj. "Effect of specimen geometry on ultrasound diffusion in cement-based aggregates." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22578.
Повний текст джерелаHughes-Riley, Theodore, John Beau Webber, Michael Ian Newton, and Robert H. Morris. "Magnetic resonance relaxation measurements using open-geometry sensors to assess the clog state of constructed wetlands." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-178572.
Повний текст джерелаForney, David C. III. "Diffusion in an absorbing porous medium : from microscopic geometry to macroscopic transport." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40293.
Повний текст джерелаThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 71-73).
Two physical models of diffusion in absorbing porous media are proposed on two length scales. One models diffusion in the pore space of a random medium with absorbing interfaces while the other is a reaction diffusion model where particles are absorbed in the bulk. Typical particle traveling distances and a bulk absorption coefficient are described in terms of general geometrical characteristics of a random medium and the analytical relations are found to compare well with numerical experiments. For the case of geometries consisting of randomly placed cubes, absorption in the bulk scales with the solid fraction to the two-thirds power. The statistical distribution of reaction rates in these models is found to be inversely related to the reaction rate. A quasi-static Monte-Carlo model is also investigated. The more complex problem of microbial extracellular enzyme distributions in marine sediment was an inspiration for this work.
by David C. Forney, III.
S.M.
Seland, John Georg. "Dynamic correlations between inhomogeneous magnetic fields, internal gradients, diffusion and transverse relaxation, as a probe for pore geometry and heterogeneity." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-178804.
Повний текст джерелаCanaguier-Durand, Antoine. "Multipolar scattering expansion for the Casimir effect in the sphere-plane geometry." Paris 6, 2011. http://www.theses.fr/2011PA066246.
Повний текст джерелаHughes-Riley, Theodore, John Beau Webber, Michael Ian Newton, and Robert H. Morris. "Magnetic resonance relaxation measurements using open-geometry sensors to assess the clog state of constructed wetlands." Diffusion fundamentals 22 (2014) 3, S. 1-8, 2014. https://ul.qucosa.de/id/qucosa%3A13476.
Повний текст джерелаSarfaraz, Wakil. "The geometric influence of domain-size on the dynamics of reaction-diffusion systems with applications in pattern formation." Thesis, University of Sussex, 2018. http://sro.sussex.ac.uk/id/eprint/79452/.
Повний текст джерелаSeland, John Georg. "Dynamic correlations between inhomogeneous magnetic fields, internal gradients, diffusion and transverse relaxation, as a probe for pore geometry and heterogeneity." Diffusion fundamentals 22 (2014) 10, S. 1-5, 2014. https://ul.qucosa.de/id/qucosa%3A13490.
Повний текст джерелаRieux, Frédéric. "Processus de diffusion discret : opérateur laplacien appliqué à l'étude de surfaces." Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20201/document.
Повний текст джерелаThe context of discrete geometry is in Zn. We propose to discribe discrete curves and surfaces composed of voxels: how to compute classical notions of analysis as tangent and normals ? Computation of data on discrete curves use average mask. A large amount of works proposed to study the pertinence of those masks. We propose to compute an average mask based on random walk. A random walk starting from a point of a curve or a surface, allow to give a weight, the time passed on each point. This kernel allow us to compute average and derivative. The studied of this digital process allow us to recover classical notions of geometry on meshes surfaces, and give accuracy estimator of tangent and curvature. We propose a large field of applications of this approach recovering classical tools using in transversal communauty of discrete geometry, with a same theorical base
Prinsloo, Rian Hendrik. "Solution of the multigroup analytic nodal diffusion equations in 3-dimensional cylindrical geometry / Rian H. Prinsloo." Thesis, North-West University, 2006. http://hdl.handle.net/10394/1460.
Повний текст джерелаDuerigen, Susan. "Neutron transport in hexagonal reactor cores modeled by trigonal-geometry diffusion and simplified P3 nodal methods." Forschungszentrum Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-124665.
Повний текст джерелаHofrichter, Julian. "On the Diffusion Approximation of Wright–Fisher Models with Several Alleles and Loci and its Geometry." Doctoral thesis, Universitätsbibliothek Leipzig, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-150016.
Повний текст джерелаCurantz, Camille. "Morphogenesis of skin pattern geometry in birds." Electronic Thesis or Diss., Sorbonne université, 2020. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2020SORUS027.pdf.
Повний текст джерелаNatural patterns constitute one of the most diverse features observed in wild animals. The development of such patterns requires a series of morphogenetic events involving a differential response of a naïve tissue to chemical and mechanical positional cues. To what extent these processes contribute to the shape of the natural variation remains unclear. In birds, feather primordia are implanted in typical geometries which vary between birds in primordia size, spacing and pattern regularity. It has been shown that the development of the feather array surely involves self-organising processes. Such processes rely on molecular and cellular factors that cumulate and cooperate temporally and spatially in the developing skin. We showed that the patterning of feather primordia involves prior regionalisation of the skin into competent domains forming a specie-specific pre-pattern that influences the resulting pattern. The comparative description of the local variation of the feather array in these birds according to their initial competent domains shows that variation in the amplitude of dermal cell anisotropy correlates with variation in pattern regularity. Using ex vivo perturbations of skin architecture by an inhibitor of actin filament polymerisation, I showed that the anisotropy of dermal cells prior to feather primordia formation can be seen a readout of the competent state of the tissue to form a regular pattern. These results provide insights into the cellular basis of self-organisation and demonstrate that tissue morphology, constrain the cell response to the positional cues and contribute to shape the variation of the geometry of the feather array observed in nature
Nardoni, Chiara. "Diffusion maps in the Subriemannian motion group and perceptual grouping." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/6971/.
Повний текст джерелаBrahmachari, Aveek Shankar. "BLOGS: Balanced Local and Global Search for Non-Degenerate Two View Epipolar Geometry." [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0003084.
Повний текст джерелаGuevara, Olivares Miguel. "Disentangling the short white matter connections using a fiber's geometry based dimensional reduction approach." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPAST053.
Повний текст джерелаThe study of superficial white matter (SWM) has often been left aside, mainly because of its high variability. Higher quality acquisition methods and the development of new analysis tools have facilitated the study of SWM from diffusion MRI and tractography. Brain connectivity and cortical folding pattern must be strongly related, especially for short U-fibers, which circumvent the folds. As the folding patterns morphology is specific to each human being, so should be the underlying fibers configuration. In this work we created a pipeline to disentangle the short white matter connections into their different configurations and to characterize their relation with other structures.First a method to delineate short bundles from a tractography set was built using a hybrid approach, by extracting fibers connecting two cortical regions of interest (ROIs) (incorporating anatomical information) and then clustering them into bundles (considering their shape), reproducible across subjects. Subjects were aligned by a T1-based affine transformation and a deterministic tractography database (79 subjects) was used. This generated a whole brain streamline bundle atlas, which allows distance-based segmentation of the bundles in new subjects, in order to perform clinical studies over specific connections. The bundles obtained were compared against other two publicly available atlases (using alternative non-linear alignment across subjects), to evaluate their reproducibility given different methods and databases. A non-negligible number of bundles were found similar among the three atlases. As SWM bundle definition is still a subjective matter, over-segmentation can nevertheless occur. However, even greater granularity is required when aiming to classify the different bundle configurations. This level of disentanglement was achieved by an ISOMAP dimensionality reduction algorithm. It aimed to stratify the population based on their fibers using geometrical changes across subjects. For each region under study, the fibers surrounding a specific sulcus were targeted and therefore the ROIs were selected accordingly. These regions are: central sulcus, superior temporal sulcus, cingulate sulcus and precentral gyrus. The method was applied over 816/897 subjects of the S900 release of the HCP database and a preprocessed probabilistic tractography database. For each region the fibers were extracted, sampled and then used in the ISOMAP computation, which in turn was employed to split the population in ten groups. In each group a refined version of a short bundle identification method was applied, in order to obtain reproducible bundles. These were then automatically matched with their corresponding ones in the other groups, based on a centroid fiber distance. A Hysteresis principle was used to recover missing bundles (previously discarded) in each group. In order to identify the bundles driving the differences reflected on each ISOMAP dimension, the correlation of the fibers geometry with the subjects ISOMAP values was performed, by using a “bundle to tractogram” distance for each pair of subjects. The fiber-based ISOMAP values were also compared to a sulcus-based ones, obtaining a high correlation for the first dimension. The bundles showing correlation with the ISOMAP values show coherent morphological transitions along the groups, and are located in areas where the sulcus also exhibits differences in shape. Moreover, the bundles are also spatially correlated to changes in functional activations. These results prove the link between the brain wiring and the cortical folding pattern. Moreover, they evidence that a finer delineation of the bundles allow the detection of differences that most of the time are blurred out due to the mixing of configurations
Dürigen, Susan [Verfasser], and R. [Akademischer Betreuer] Stieglitz. "Neutron Transport in Hexagonal Reactor Cores Modeled by Trigonal-Geometry Diffusion and Simplified P3 Nodal Methods / Susan Dürigen. Betreuer: R. Stieglitz." Karlsruhe : KIT-Bibliothek, 2013. http://d-nb.info/1034865706/34.
Повний текст джерелаMeco, Halim. "Solidification at the High and Low Rate Extreme." Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2004. http://www.osti.gov/servlets/purl/835376-9UiMWH/webviewable/.
Повний текст джерелаPezzi, Luigi. "Advanced numerical modeling of masonry vaulted structures based on BIM parametric geometry generation." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
Знайти повний текст джерелаDi, Santo Dario. "Study of anabatic flows using large-eddy simulations in a simplified geometry." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20762/.
Повний текст джерелаHofrichter, Julian [Verfasser], Jürgen [Akademischer Betreuer] Jost, Jürgen [Gutachter] Jost, and Angela [Gutachter] Stevens. "On the Diffusion Approximation of Wright–Fisher Models with Several Alleles and Loci and its Geometry / Julian Hofrichter ; Gutachter: Jürgen Jost, Angela Stevens ; Betreuer: Jürgen Jost." Leipzig : Universitätsbibliothek Leipzig, 2014. http://d-nb.info/1238788602/34.
Повний текст джерелаGhanbarian-Alavijeh, Behzad. "Modeling Physical and Hydraulic Properties of Disordered Porous Media: Applications from Percolation Theory and Fractal Geometry." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1401380554.
Повний текст джерелаSugar, Joshua D. "Mechanisms of microstructure development at metallic-interlayer/ceramic interfaces during liquid-film-assisted bonding." Berkeley, Calif. : Oak Ridge, Tenn. : Lawrence Berkeley National Laboratory ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2003. http://www.osti.gov/servlets/purl/825347-j6A0Su/native/.
Повний текст джерелаPublished through the Information Bridge: DOE Scientific and Technical Information. "LBNL--54185" Sugar, Joshua D. USDOE Director. Office of Science. Basic Energy Sciences (US) 12/01/2003. Report is also available in paper and microfiche from NTIS.
Kervil, Ronan. "Matière active et écoulements : jets de bactéries et nageurs interfaciaux." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1039/document.
Повний текст джерелаThis work address different situations where active matter, made out of self-propelled particles, is submitted to external constraints.In a first part, we consider the response of magnetotactic bacteria –capable of swim alignment along magnetic field lines- directed through an hourglass shape geometry. We characterize the dynamic properties of the system, both at the individual bacteria scale and at the scale of the jammed region or of the induced outgoing jet. We show that in high density regions, couplings between the bacteria interactions, swim velocity and magnetic forcing take a much more complex form than had been considered so far in theoretical models.In a second chapter, we are addressing a new active system made out of camphor disks lying at the air-water interface. First of all, we study in details the individual swim properties of such particles, which spontaneously break the system symmetry to start moving. In particular, we show that all experimental data can be rationalized within the framework of a very simple model of this complex problem where hydrodynamic flows and surfactant transports are coupled through Marangoni stress.In a last chapter, we addressed the collective dynamics of an assembly of such interfacial swimmers that interact through the flow and chemical fields they generate. At intermediate swimmers concentrations, an intermittent swim regime appears characterized by pseudo-periodic activity bursts. Using tools and concepts from the turbulence domain, we show that, remarkably, this simple system exhibits dynamical properties matching the ones of canonical turbulence as predicted by Kolmogorov in the 40s. This demonstration opens up rich perspectives in the historical domain of turbulence together with in the emerging one of active matter
Jacob, Dolly. "Investigation into reliability and performance of an implantable closed-loop insulin delivery device." Thesis, De Montfort University, 2014. http://hdl.handle.net/2086/11126.
Повний текст джерелаPreusser, Tobias. "Anisotropic geometric diffusion in image and image sequence processing." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=97051879X.
Повний текст джерелаSOUZA, LEANDRO CARLOS DE. "FEATURE PRESERVING MESH SIMPLIFICATION BASED ON MARKOV GEOMETRIC DIFFUSION." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=21556@1.
Повний текст джерелаO uso de modelos computacionais baseados em malhas 3D se torna cada vez mais frequente em diversas áreas da computação como em jogos, animações e simuladores de realidade virtual, por exemplo. Entretanto, malhas que possuem uma grande quantidade de elementos exigem um alto poder computacional para serem manipuladas. A fim de resolver este problema são utilizados métodos de simplicação para reduzir o número de elementos, preservando a topologia que o modelo apresenta. Neste trabalho é introduzido um método de Difusão Geométrica Markoviana - difusão calculada na forma de probabilidades de transição e construída sobre um conjunto de pontos organizados geometricamente - aplicado na malha. Esse método combina uma estratégia baseada em uma Cadeia de Markov de base geométrica, que controla probabilisticamente o comportamento das normais na malha, com métodos de simplicação que são capazes de avaliar o impacto que a remoção de um elemento provoca na estrutura da malha. Métricas de avaliação são utilizadas para comparar o erro cometido em relação à malha original.
Computational models based on 3D meshes are ubiquitous in are such as game, animations and virtual reality. However, very large data sets are frequently produced, e.g. by scanners 3D and fluid dynamics simulations, wich require high computer power to be handled. Mesh simplification tecniques, preserving the topology and the geometry of the mesh, are then implemented to bring the datea to a size suited to be used in such areas. In this work we introduce a new tecnique wich we call Markov Geometric Diffusion based on probability transition matrix tecniques and built upon a data set organized geometricallyas a mesh. This method puts together a strategy based on a geometrically constructed Markov chain, wich control, in a probabilistic way, a normal vector field to the mesh, with a simplification method capable of estimating the impact of element removal in the mesh structure. Several error evaluation metrics are used tocompare the error of the simplified mesh with the original one.
Lenglet, Christophe. "Geometric and variational methods for diffusion tensor MRI processing." Nice, 2006. http://www.theses.fr/2006NICE4083.
Повний текст джерелаThis thesis deals with the development of new processing tools for Diffusion Tensor Magnetic Resonance Imaging (DT-MRI). This recent MRI technique is of utmost importance to acquire a better understanding of the brain mechanisms and to improve the diagnosis of neurological disorders. We introduce new algorithms relying on Riemannian geometry, partial differential equations and front propagation techniques. The first part of this work is theoretical. After a few reminders about the human nervous system, MRI and differential geometry, we study the space of multivariate normal distributions. The introduction of a Riemannian structure on that space allows us to define statistics and intrinsic numerical schemes that will constitute the core of the algorithms proposed in the second part. The properties of that space are important for DT-MRI since diffusion tensors are the covariance matrices of normal laws modeling the diffusion of water molecules at each voxel of the acquired volume. The second part of this thesis is methodological. We start with the introduction of original approaches for the estimation and regularization of DT-MRI. We then show how to evaluate the degree of connectivity between cortical areas. Next, we introduce a statistical surface evolution framework for the segmentation of those images. Finally, we propose a non-rigid registration method. The last part of this thesis is dedicated to the application of our tools to two important neuroscience problems: the analysis of the connections between the cerebral cortex and the basal ganglia, implicated in motor tasks, and the study of the anatomo-functional network of the human visual cortex
GAMA, Fernando José de Almeida. "Acoplamento massa-energia na descrição de secagem de produtos cilíndricos." Universidade Federal de Campina Grande, 2014. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/458.
Повний текст джерелаMade available in DSpace on 2018-04-23T16:23:25Z (GMT). No. of bitstreams: 1 FERNANDO JOSÉ DE ALMEIDA GAMA - TESE PPGEP 2014..pdf: 3506912 bytes, checksum: c91b94e7df5d978098c9d79aa8eb7487 (MD5) Previous issue date: 2014-12-19
Este trabalho tem como objetivo estudar o fenômeno da difusão transiente de transferência de calor e massa em sólidos com forma geométrica de um cilindro infinito. O estudo apresenta soluções para a equação de difusão com condição de contorno do terceiro tipo. Foram desenvolvidas ferramentas numéricas para a descrição da difusão de calor e massa em produtos com as formas mencionadas. Para as soluções numéricas propostas, a equação de difusão unidimensional foi discretizada usando o método dos volumes finitos, com uma formulação totalmente implícita, usando coordenadas cilíndricas. Para a solução numérica em coordenadas cilíndricas, foram desenvolvidos dois softwares na plataforma Windows, um para a migração de massa e outro para a propagação de calor, utilizando a linguagem de programação Fortran, opção Quick Win Application. O software foi validado usando-se soluções conhecidas para cilindros tanto com parâmetros termofísicos constantes quanto variáveis. Pode-se concluir que as ferramentas desenvolvidas foram adequadas para o estudo de problemas difusivos em geral. As ferramentas desenvolvidas foram usadas para descrever o processo de secagem de bananas inteiras. Na descrição, foram considerados volume e difusividade de calor e massa variáveis. Pode-se concluir que o modelo proposto para descrever o processo apresentou excelentes indicadores estatísticos na descrição da cinética de transferência de calor e massa. Pode-se concluir, também, que a exclusão do aquecimento do vapor nos cálculos efetuados não altera de forma significativa os resultados e que o uso do calor latente da água livre ao invés desta propriedade no produto não produz efeitos significativos. Por outro lado, o desprezo do calor latente de vaporização e a consideração da densidade e do calor específico do produto como propriedades constantes devem ser evitados.
This work aims to study the phenomenon of the transient diffusion of heat and mass in solids with geometric form of an infinite cylinder. The study presents solutions for the diffusion equation with boundary condition of the third kind. Numerical tools for describing the diffusion of heat and mass in the ways mentioned were developed. For the numerical solutions proposed, the one-dimensional diffusion equation was discretized using the finite volume method with a fully implicit formulation, using cylindrical coordinates. For the numerical solution in cylindrical coordinates, two software have been developed on the Windows platform, one for mass migration and one for the heat transfer, using the Fortran programming language, Quick Win Application option. The software was validated using solutions known for cylinders with both constant and variable thermophysical parameters. It can be concluded that the developed tools were appropriate for the study of diffusion problems in general. The above tools were used to describe the process of drying whole banana. In the description, we considered the volume and diffusivities with variables values. It can be concluded that the proposed model to describe the process showed excellent statistical indicators to describe the kinetics of heat and mass transfer. One can also conclude that the exclusion of the vapor heating in the calculations performed does not significantly alter the results. In addition that using the latent heat of free water instead of this property in the product does not produce significant effects. On the other hand, discard the latent heat of vaporization and the consideration of density and specific heat of the product as constant properties should be avoided.
De, Zan Cecilia. "Some new results on reaction-diffusion equations and geometric flows." Doctoral thesis, Università degli studi di Padova, 2012. http://hdl.handle.net/11577/3422529.
Повний текст джерелаIn questa tesi discutiamo il comportamento asintotico delle soluzioni di equazioni di reazione-diffusione nel dominio illimitato Rn × (0,+∞) nei casi in cui tale comportamento sia descritto da un’interfaccia in movimento. Come primo tipo di problemi asintotici consideriamo il limite singolare di equazioni di reazione-diffusione bistabili nel caso in cui la velocità dell’onda viaggiante dipenda dalla variabile di stato, cioè cε = cε(x), e sia soddisfatto, al tendere di ε a zero e in qualche modo opportuno, cε/ετ → α, laddove α è una funzione discontinua e τ è un intero che può essere uguale a 0 o a 1. La seconda parte della tesi riguarda equazioni di reazione-diffusione semilineari e aventi termini di diffusione del tipo tr(Aε(x)D2uε), laddove tr denota l’operatore traccia, Aε = σεσtε per qualche funzione σε : Rn → Rn×(m+n) e Aε converge ad una matrice degenere. Al fine di provare tali risultati in modo rigoroso, abbiamo modificato e adattato "l’approccio geometrico" introdotto da G. Barles e P. E. Souganidis per risolvere problemi in Rn e in seguito parzialmente rivisto dallo stesso G. Barles assieme a F. Da Lio per equazioni di reazione-diffusione in domini limitati. Laddove possibile abbiamo sempre considerato la questione della buona posizione dei problemi di Cauchy che governano il moto dei fronti che descrivono le asintotiche da noi considerate
Panagiotaki, E. "Geometric models of brain white matter for microstructure imaging with diffusion MRI." Thesis, University College London (University of London), 2011. http://discovery.ucl.ac.uk/1310435/.
Повний текст джерелаLOBRY, LAURENT. "Etude par diffusion de la lumiere d'un mouvement brownien en geometrie confinee." Nice, 1996. http://www.theses.fr/1996NICE4947.
Повний текст джерелаMastrolia, P. "GRADIENT ESTIMATES AND LIOUVILLE THEOREMS FOR DIFFUSION-TYPE OPERATORS ON COMPLETE RIEMANNIAN MANIFOLDS." Doctoral thesis, Università degli Studi di Milano, 2011. http://hdl.handle.net/2434/153097.
Повний текст джерелаManay, Siddharth. "Applications of anti-geometric diffusion of computer vision : thresholding, segmentation, and distance functions." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/33626.
Повний текст джерелаAl-Sawai, Wael. "Non-equilibrium Phase Transitions in Interacting Diffusions." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7660.
Повний текст джерелаHarley, Kristen E. "Canards in advection-reaction-diffusion systems in one spatial dimension." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/79261/1/Kristen_Harley_Thesis.pdf.
Повний текст джерелаSilva, Odair Pinheiro da. "Modelagem computacional da estabilização de sistemas subcríticos segundo o modelo unidimensional de difusão de nêutrons monoenergéticos." Universidade do Estado do Rio de Janeiro, 2014. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=6836.
Повний текст джерелаUm método numérico espectronodal (END) livre de erros de truncamento espacial é desenvolvido para problemas unidimensionais de difusão de nêutrons monoenergéticos em duas versões. Na versão de problemas de autovalor, o método gera soluções numéricas para o perfil do fluxo escalar e para o fator de multiplicação efetivo (k), que coincidem com a solução analítica dominante, afora os erros da aritmética finita computacional. Na versão de fonte fxa, o método também gera soluções numéricas analíticas para o problema de fonte fixa correspondente, onde a fonte de fissão, com dependência espacial, é obtida analiticamente, a partir da reconstrução espacial do fluxo escalar gerado pelo método END para problemas de autovalor. Alguns experimentos numéricos são apresentados para dois problemas modelos a fim de ilustrar a precisão do método.
Roy, Samit. "A finite element analysis of adhesively bonded composite joints including geometric nonlinearity, nonlinear viscoelasticity, moisture diffusion and delayed failure." Diss., Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/88624.
Повний текст джерелаDoctor of Philosophy
Ziegler, Kai U. [Verfasser]. "Experimentelle Untersuchung der Laufrad-Diffusor-Interaktion in einem Radialverdichter variabler Geometrie / Kai U Ziegler." Aachen : Shaker, 2003. http://d-nb.info/1170542824/34.
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