Log in

Relevant bibliographies by topics / Phase transition (Statistical physics) / Dissertations / Theses

To see the other types of publications on this topic, follow the link: Phase transition (Statistical physics).

Dissertations / Theses on the topic 'Phase transition (Statistical physics)'

Author: Grafiati

Published: 4 June 2021

Last updated: 5 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'Phase transition (Statistical physics).'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Raoufi, Aran. "Topics on the Phase Transition of the Lattice Models of Statistical Physics." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS572.

Full text

Abstract:

Le thème de cette thèse est l’utilisation de méthodes probabilistes (plus spécifiquement de technique venant de la théorie de la percolation) pour mener une analyse non-perturbative de plusieurs modèles de physique statistique. La thèse est centrée sur les systèmes de spins et les modèles de percolation. Cette famille de modèle comprend le modèle d’Ising, le modèle de Potts, la percolation de Bernoulli, la percolation de Fortuin-Kasteleyn et les modèles de percolation continue. L’objectif principal de la thèse est de démontrer la décroissance exponentielle des corrélations au-dessus de la température critique et d’étudier les états de Gibbs des modèles en dessus<br>The underlying theme of this thesis is using probabilistic methods and especially techniques of percolation theory to carry on a non-perturbative analysis of several models of statistical physics. The focus of this thesis is set on spin systems and percolation models including the Ising model, the Potts model, the Bernoulli percolation, the random-cluster model, and the continuum percolation models. The main objective of the thesis is to demonstrate exponential decay of correlations above the critical temperature and study the Gibbs states of the mentioned models

APA, Harvard, Vancouver, ISO, and other styles

2

Ling, Tsz Yan. "Phase transition behaviors of multi-component atmospheric aerosols : presence of double salts and mixed phases /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?CENG%202007%20LING.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

An, Ran. "Study of the field-induced phase transition for the antiferromagnetic chain /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?MATH%202006%20AN.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Lumsden, Mark D. "X-ray scattering study of the spin-peierls phase transition /." *McMaster only, 1998.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

5

Rabe, Karin M. (Karin Maria). "Ab initio statistical mechanics of structural phase transitions." Thesis, Massachusetts Institute of Technology, 1987. http://hdl.handle.net/1721.1/14630.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Zhao, Jie-hua. "Thermomechanical properties and phase transition of thin and ultra-thin films /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Wincure, Benjamin 1966. "Computational modeling of a liquid crystal phase transition." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103308.

Full text

Abstract:

This thesis numerically solves the tensor order parameter continuum theory equations for nematic liquid crystals to investigate liquid crystal texturing mechanisms during an isotropic to nematic phase transition in a bulk unstable isotropic phase and next to solid surfaces. The Time Dependent Ginsburg Landau equation with a Landau de Gennes Helmholtz free energy density description is used to predict the shapes, textures and defect mechanisms that occur in the expanding droplets and films of a 4'-pentyl-4-cyanobiphenyl (5CB) nematic phase immediately after their nucleation from an unstable isotropic phase, due to a temperature quench. To create a robust simulation method able to tackle high curvature, defect nucleation, heterogeneous substrates and phase ordering interfaces, particular attention was paid to adapting the mathematical model and computational methods to what was previously known about the nucleation and growth events that occur experimentally during a bulk 5CB isotropic to nematic phase transition and next to decorated solid surfaces. The numerical simulations provide detailed predictions about (i) growth rates for different temperature quenches, (ii) structure of the isotropic-nematic interface, (iii) shapes of expanding nano and submicron nematic droplets, (iv) texturing within growing nano and submicron nematic droplets, (v) a new defect formation mechanism called "interfacial defect shedding", and (vi) the effect of contact angle and interface curvature next to a solid surface with anchoring switches. The main contributions of this thesis are its detailed predictions that emerge from the liquid crystal simulation results, the careful adaptation of the mathematical model and numerical method to what is currently known about early stage growth in a nematic liquid crystal phase, and the validation of new theory by the simulation results.

APA, Harvard, Vancouver, ISO, and other styles

8

Xu, Hui. "Phase structure and phase transitions in semicrystalline isotactic polystyrene /." Thesis, Connect to Dissertations & Theses @ Tufts University, 2005.

Find full text

Abstract:

Thesis (Ph.D.)--Tufts University, 2005.<br>Adviser: Peggy Cebe. Submitted to the Dept. of Physics. Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;

APA, Harvard, Vancouver, ISO, and other styles

9

Akki, Rashi. "Morphological implications of phase transitions in polymer solutions : inferences from polyacrylonitrile-based solutions." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/15783.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Spalek, Leszek Jedrzej. "Emergent phenomena near selected phase transitions." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608135.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Ha, Meesoon. "Scaling and phase transitions in one-dimensional nonequilibrium driven systems /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/9758.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Saunders, Timothy E. "Phase transitions in geometrically frustrated antiferromagnets." Thesis, University of Oxford, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670121.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Skibinsky, Anna. "Modeling liquid-liquid phase transitions and quasicrystal formation." Thesis, Boston University, 2003. https://hdl.handle.net/2144/42658.

Full text

Abstract:

Thesis (Ph. D.)--Boston University, 2003.<br>In this thesis, studies which concern two different subjects related to phase transitions in fluids and crystalline solids are presented. Condensed matter formation, structure, and phase transitions are modeled using molecular dynamics simulations of simple discontinuous potentials with attractive and repulsive interactions. Novel phase diagrams are proposed for quasicrystals, crystals, and liquids. In the first part of the thesis, the formation of a quasicrystal in a two dimensional monodisperse system is investigated using molecular dynamics simulations of hard sphere particles interacting via a two-dimensional square-well potential. It is found that for certain values of the square-well parameters more than one stable crystalline phase can form. By quenching the liquid phase at a very low temperature, an amorphous phase is obtained. When this the amorphous phase is heated, a quasicrystalline structure with five-fold symmetry forms. From estimations of the Helmholtz potentials of the stable crystalline phases and of the quasicrystal, it is concluded that within a specific temperature range, the observed quasicrystal phase can be the stable phase. The second part of the thesis concerns a study of the liquid-liquid phase transition for a single-component system in three dimensions, interacting via an isotropic potential with a repulsive soft-core shoulder at short distance and an attractive well at an intermediate distance. The potential is similar to potentials used to describe [TRUNCATED}

APA, Harvard, Vancouver, ISO, and other styles

14

Sen, Asok Kumar. "Part I, traveling cluster approximation for uncorrelated amorphous systems ; Part II, influence of long-range forces on the wetting transition /." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487260859496667.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Larochelle, Christie L. "Optical Studies of Layered Inorganic Solids: A Novel Phase Transition and Energy Transfer Studies." Fogler Library, University of Maine, 2001. http://www.library.umaine.edu/theses/pdf/LarochelleCL2001.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Fulton, Sharon. "Scattering studies of excitations and phase transitions." Thesis, University of Oxford, 1993. http://ora.ox.ac.uk/objects/uuid:45f661ac-61cc-4a0c-9e96-636866a99cf2.

Full text

Abstract:

This thesis describes a diversity of scattering experiments on a number of different systems. Using time-of-flight neutron scattering, a study of polycrystalline sodium in the highmomentum limit known as the impulse approximation has been performed. The purpose of this study was to look for anharmonic effects in the neutron recoil scattering of sodium as the temperature was increased from 30K to 300K. No such effects were detected and the results agreed with an isotropic harmonic solid to an accuracy of about 4%. Two experiments were carried out on antiferromagnetic systems using triple-axis neutron scattering techniques to measure the spin-wave dispersion relations. The first was on CuO to verify its description as a spin 1/2 one-dimensional antiferromagnet. The dispersion relation was measured along the chain direction up to an energy transfer of 8OmeV. This was done above and below the Néel temperature (T<sub>N</sub> =240K). However, no evidence was seen to justify the description of CuO as a one-dimensional antiferromagnet, with the spin waves behaving like those in a classical three-dimensional system. The other spin-wave study examined the two-dimensional antiferromagnet KFeF<sub>4</sub> . The measurement of the spin-wave dispersion relation at two temperatures (50K and 100K) below the Néel temperature (T<sub>N</sub> =136.75±0.25K), confirmed the description of KFeF<sub>4</sub> as a two-dimensional Heisenberg antiferromagnet with small Ising anisotropy. Studies of the magnetic phase transition in KFeF<sub>4</sub> revealed that below the Néel temperature, the critical behaviour is described by two-dimensional Ising models, and above a crossover to Heisenberg behaviour is seen. This crossover was detected by measuring the order parameter below T<sub>N</sub>, and the static and dynamic susceptibilities above T<sub>N</sub> using neutron scattering techniques. The results were compared to power-law behaviour and also to theories for the classical Heisenberg antiferromagnet and the more recent quantum Heisenberg antiferromagnetic model. The final study of KFeF<sub>4</sub> involved an x-ray experiment on the structural phase transition around 400K. It has been suggested that there is a second-order transition at 410K to an incommensurate phase, which then undergoes a first-order lock-in transition at 400K to the low-temperature structure. This single crystal x-ray scattering study confirms the existence of the first-order phase transition, but shows no evidence for a higher temperature second-order transition or for the incommensurate phase.

APA, Harvard, Vancouver, ISO, and other styles

17

Rowley, Stephen Edward. "Quantum phase transitions in ferroelectrics." Thesis, University of Cambridge, 2011. https://www.repository.cam.ac.uk/handle/1810/252224.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Kelly, Shelly D. "XAFS study of the pressure induced B1->B2 phase transition /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/9679.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Jones, Nicholaos John. "Ineliminable idealizations, phase transitions, and irreversibility." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1163026373.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Kobayashi, Kohjiro. "Topics in classical and quantum phase transitions." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1199254396.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Costa, Andre. "Phase transitions in low-dimensional driven systems." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/7826.

Full text

Abstract:

The study of non-equilibrium physics is an area of interest since, unlike for their equilibrium counterparts, there exists no general framework for solving such systems. In this thesis I investigate the emergence of structure and front propagation in driven systems, a special type of system within the area of non-equilibrium physics. In particular I focus on three particular one-dimensional models each of which illustrate this in a different way. The Driven Asymmetric Contact Process (DACP) describes a system where activity is continuously generated at one end of a one-dimensional lattice and where this activity is allowed to spread in one direction along the lattice. In the DACP one observes a propagating wave of activity which appears to abruptly vanish as the system undergoes a phase transition. Using a modified Fisher equation to model the system reveals the continued existence of the propagating wave, now contained within a decaying envelope. Furthermore this establishes relations between properties of the travelling wave and Directed Percolation critical exponents. The Zero-Range Process (ZRP) is a much studied system exhibiting a condensation transition. In the ZRP individual particles hop along a lattice at rates which depend only on the occupancy of the departure site. Here I investigate a modi cation of the ZRP where instead the majority of the particles at a site depart during a single hopping event. For this, the Chipping model, a condensate which propagates along the lattice is observed. It is found that this condensation transition is present even for hop rates which fall foul of the condensation requirements of the normal ZRP. Further it is observed that, unlike for normal ZRP, condensation occurs even in the low-density limit. As a result I suggest a condensation mechanism which depends only on the hop rates of low occupancy sites. The Host-Solute-Vacancy model (HSV) is a three-species system designed to model electromigration in a circuit. As the parameter space is navigated the system undergoes what appear to be two separate phase transitions from a randomly distributed state to a condensed state with either of two structures. To investigate the model new measures for determining condensation are developed. These show that, again, condensation occurs in the low-density limit. By a reduction to a ZRP an effective hop rate of the system is measured. This effective hop rate is found to beta function of the occupancy of a site as a fraction of the total system size. To explain this behaviour I invoke a description whereby there is a step in the hop rate as a function of occupancy. Through these three examples I illustrate how minor modi cations to the dynamics of known systems can result in a new and rich phenomenology. I draw particular attention to the effect of asymmetry in the dynamics.

APA, Harvard, Vancouver, ISO, and other styles

22

Li, Huaming. "Theory of phase transitions in disordered crystal solids." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29707.

Full text

Abstract:

Thesis (Ph.D)--Physics, Georgia Institute of Technology, 2009.<br>Committee Chair: Li Mo; Committee Member: Chou Meiyin; Committee Member: First Phillip; Committee Member: Nguyen Toan; Committee Member: Zangwill Andrew. Part of the SMARTech Electronic Thesis and Dissertation Collection.

APA, Harvard, Vancouver, ISO, and other styles

23

Cheng, Juan. "Light scattering study on phase transition and micro-heterogeneity in relaxor ferroelectrics (1-x)Pb(Mg₁/₃Nb₂/₃)O₃-xPbTiO₃ and (1-x)Pb(Zn₁/₃Nb2₂/₃)O₃-xPbTiO₃ /." access full-text access abstract and table of contents, 2009. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?phd-ap-b23749179f.pdf.

Full text

Abstract:

Thesis (Ph.D.)--City University of Hong Kong, 2009.<br>"Submitted to Department of Physics and Material Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references (leaves 140-167)

APA, Harvard, Vancouver, ISO, and other styles

24

Lim, Sze-Wah. "Competing population : effects of diverse preferences and a finite-size scaling theory of dynamical transitions /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?PHYS%202006%20LIM.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Roland, Christopher. "Phase transitions of phospholipid monolayers on air-water interfaces." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66032.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Chen, Michael H. "Magnetic phase transitions in praseodymium-barium doped manganites." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2007. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Chen, Leiming. "Tilt phase transitions in disordered systems /." view abstract or download file of text, 2006. http://proquest.umi.com/pqdweb?did=1251884301&sid=1&Fmt=2&clientId=11238&RQT=309&VName=PQD.

Full text

Abstract:

Thesis (Ph. D.)--University of Oregon, 2006.<br>Typescript. Includes vita and abstract. Includes bibliographical references (leaves 126-128). Also available for download via the World Wide Web; free to University of Oregon users.

APA, Harvard, Vancouver, ISO, and other styles

28

Morgan, Benjamin John. "Pressure driven phase transitions in tetrahedrally coordinated nanocrystals : a simulation study." Thesis, University of Oxford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670204.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Crnkic, Edin. "Geometry guided phase transition pathway and stable structure search for crystals." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44760.

Full text

Abstract:

Recently a periodic surface model was developed to assist geometric construction in computer-aided nano-design. This implicit surface model helps create super-porous nano structures parametrically and support crystal packing. In this thesis, a new approach for pathway search in phase transition simulation of crystal structures is proposed. The approach relies on the interpolation of periodic loci surface models. Respective periodic plane models are reconstructed from the positions of individual atoms at the initial and final states, and surface correspondence is found using a Simulated Annealing-like algorithm. With geometric constraints imposed based on physical and chemical properties of crystals, two surface interpolation methods are used to approximate the intermediate atom positions on the transition pathway in the full search of the minimum energy path. This hybrid approach integrates geometry information in configuration space and physics information to allow for efficient transition pathway search. The methods are demonstrated by examples of FeTi, VO2, and FePt. Additionally, two new particle swarm optimization (PSO) algorithms are developed and applied to crystal structure relaxation of the initial and final states. The PSO algorithms are integrated into the Quantum-Espresso open-source software package and tested against the default Broyden-Fletcher-Goldfarb-Shanno relaxation method.

APA, Harvard, Vancouver, ISO, and other styles

30

Schief, William R. "Phase transitions in two-dimensional model systems /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/9806.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Guttal, Vishwesha. "Applications of nonequilibrium statistical physics to ecological systems." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1209696541.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

He, Lijuan. "A global search algorithm for phase transition pathways in computer-aided nano-design." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50248.

Full text

Abstract:

One of the most important design issues for phase change materials is to engineer the phase transition process. The challenge of accurately predicting a phase transition is estimating the true value of transition rate, which is determined by the saddle point with the minimum energy barrier between stable states on the potential energy surface (PES). In this thesis, a new algorithm for searching the minimum energy path (MEP) is presented. The new algorithm is able to locate both the saddle point and local minima simultaneously. Therefore no prior knowledge of the precise positions for the reactant and product on the PES is needed. Unlike existing pathway search methods, the algorithm is able to search multiple transition paths on the PES simultaneously, which gives us a more comprehensive view of the energy landscape than searching individual ones. In this method, a Bézier curve is used to represent each transition path. During the searching process, the reactant and product states are located by minimizing the two end control points of the curve, while the shape of the transition pathway is refined by moving the intermediate control points of the curve in the conjugate directions. A curve subdivision scheme is developed so that multiple transitions paths can be located. The algorithm is demonstrated by examples of LEPS potential, LEPS plus harmonic oscillator potential, and PESs defined by Rastrigin function and Schwefel function.

APA, Harvard, Vancouver, ISO, and other styles

33

De, Nigris Sarah. "Influence of Network topology on the onset of long-range interaction." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4718.

Full text

Abstract:

Dans cette thèse, nous discutons l'influence d'un réseau qui possède une topologie non triviale sur les propriétés collectives d'un modèle hamiltonien pour spins,le modèle $XY$, défini sur ces réseaux.Nous nous concentrons d'abord sur la topologie des chaînes régulières et du réseau Petit Monde (Small World), créé avec le modèle Watt- Strogatz.Nous contrôlons ces réseaux par deux paramètres $\gamma$, pour le nombre d' interactions et $p$, la probabilité de ré-attacher un lien aléatoirement.On définit deux mesures, le chemin moyen $\ell$ et la connectivité $C$ et nous analysons leur dépendance de $(\gamma,p)$.Ensuite,nous considérons le comportement du modèle $XY$ sur la chaîne régulière et nous trouvons deux régimes: un pour $\gamma<1,5$,qui ne présente pas d'ordre longue portée et un pour $\gamma>1,5$ où une transition de phase du second ordre apparaît.Nous observons l'existence d'un état métastable pour $\gamma_ {c} = 1,5$. Sur les réseaux Petit Monde,nous illustrons les conditions pour avoir une transition et comment son énergie critique $\varepsilon_{c}(\gamma,p)$ dépend des paramètres $(\gammap$).Enfin,nous proposons un modèle de réseau où les liens d'une chaîne régulière sont ré-attachés aléatoirement avec une probabilité $p$ dans un rayon spécifique $r$. Nous identifions la dimension du réseau $d(p,r)$ comme un paramètre crucial:en le variant,il nous est possible de passer de réseaux avec $d<2$ qui ne présentent pas de transition de phase à des configurations avec $d>2$ présentant une transition de phase du second ordre, en passant par des régimes de dimension $d=2$ qui présentent des états caractérisés par une susceptibilité infinie et une dynamique chaotique<br>In this thesis we discuss the influence of a non trivial network topology on the collective properties of an Hamiltonian model defined on it, the $XY$ -rotors model. We first focus on networks topology analysis, considering the regular chain and a Small World network, created with the Watt-Strogatz model. We parametrize these topologies via $\gamma$, giving the vertex degree and $p$, the probability of rewiring. We then define two topological parameters, the average path length $\ell$and the connectivity $C$ and we analize their dependence on $\gamma$ and $p$. Secondly, we consider the behavior of the $XY$- model on the regular chain and we find two regimes: one for $\gamma<1.5$, which does not display any long-range order and one for $\gamma>1.5$ in which a second order phase transition of the magnetization arises. Moreover we observe the existence of a metastable state appearing for $\gamma_{c}=1.5$. Finally we illustrate in what conditions we retrieve the phase transition on Small World networks and how its critical energy $\varepsilon_{c}(\gamma,p)$ depends on the topological parameters $\gamma$ and $p$. In the last part, we propose a network model in which links of a regular chain are rewired according to a probability $p$ within a specific range $r$. We identify a quantity, the network dimension $d(p,r)$ as a crucial parameter. Varying this dimension we are able to cross over from topologies with $d<2$ exhibiting no phase transitions to ones with $d>2$ displaying a second order phase transition, passing by topologies with dimension $d=2$ which exhibit states characterized by infinite susceptibility and macroscopic chaotic dynamical behavior

APA, Harvard, Vancouver, ISO, and other styles

34

Chapman, Brandon D. "The role of disorder in structural phase transitions in perovskite ferroelectrics /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/9692.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Morgan, Nathaniel Ray. "A New Liquid-Vapor Phase Transition Technique for the Level Set Method." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6895.

Full text

Abstract:

The level set method offers a simple and robust approach to modeling liquid-vapor interfaces that arise in boiling and condensing flows. The current liquid-vapor phase-transition techniques used with the level set method are not able to account for different thermal conductivities and specific heats in each respective phase, nor are they able to accurately account for latent heat absorption and release. This paper presents a new level set based technique for liquid-vapor phase-transition that accounts for different material properties in each respective phase, such as thermal conductivity and specific heat, while maintaining the interface at the saturation temperature. The phase-transition technique is built on the ghost fluid framework coupled with the standard level set method. A new technique is presented for constructing ghost nodes that implicitly captures the immersed boundary conditions and is second order accurate. The method is tested against analytical solutions, and it is used to model film boiling. The new phase-transition technique will greatly assist efforts to accurately capture the physics of boiling and condensing flows. In addition to presenting a new phase transition technique, a coupled level set volume of fluid advection scheme is developed for phase transition flows. The new scheme resolves the mass loss problem associated with the level set method, and the method provides an easy way to accurately calculate the curvature of an interface, which can be difficult with the volume of fluid method. A film boiling simulation is performed to illustrate the superior performance of the coupled level set volume of fluid approach over the level set method and the volume of fluid method.

APA, Harvard, Vancouver, ISO, and other styles

36

Keung, Suet Kwan. "Phase transitions in solid C₆₀ doped with C₇₀ : a study with dielectric spectroscopy." HKBU Institutional Repository, 2001. http://repository.hkbu.edu.hk/etd_ra/281.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Hines, Andrew Peter. "Entanglement, dynamical bifurcations and quantum phase transitions /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19792.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Streib, Amanda Pascoe. "Markov chains at the interface of combinatorics, computing, and statistical physics." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43628.

Full text

Abstract:

The fields of statistical physics, discrete probability, combinatorics, and theoretical computer science have converged around efforts to understand random structures and algorithms. Recent activity in the interface of these fields has enabled tremendous breakthroughs in each domain and has supplied a new set of techniques for researchers approaching related problems. This thesis makes progress on several problems in this interface whose solutions all build on insights from multiple disciplinary perspectives. First, we consider a dynamic growth process arising in the context of DNA-based self-assembly. The assembly process can be modeled as a simple Markov chain. We prove that the chain is rapidly mixing for large enough bias in regions of Z^d. The proof uses a geometric distance function and a variant of path coupling in order to handle distances that can be exponentially large. We also provide the first results in the case of fluctuating bias, where the bias can vary depending on the location of the tile, which arises in the nanotechnology application. Moreover, we use intuition from statistical physics to construct a choice of the biases for which the Markov chain M_mon requires exponential time to converge. Second, we consider a related problem regarding the convergence rate of biased permutations that arises in the context of self-organizing lists. The Markov chain M_nn in this case is a nearest-neighbor chain that allows adjacent transpositions, and the rate of these exchanges is governed by various input parameters. It was conjectured that the chain is always rapidly mixing when the inversion probabilities are positively biased, i.e., we put nearest neighbor pair x<y in order with bias 1/2 <= p_{xy} <= 1 and out of order with bias 1-p_{xy}. The Markov chain M_mon was known to have connections to a simplified version of this biased card-shuffling. We provide new connections between M_nn and M_mon by using simple combinatorial bijections, and we prove that M_nn is always rapidly mixing for two general classes of positively biased {p_{xy}}. More significantly, we also prove that the general conjecture is false by exhibiting values for the p_{xy}, with 1/2 <= p_{xy} <= 1 for all x< y, but for which the transposition chain will require exponential time to converge. Finally, we consider a model of colloids, which are binary mixtures of molecules with one type of molecule suspended in another. It is believed that at low density typical configurations will be well-mixed throughout, while at high density they will separate into clusters. This clustering has proved elusive to verify, since all local sampling algorithms are known to be inefficient at high density, and in fact a new nonlocal algorithm was recently shown to require exponential time in some cases. We characterize the high and low density phases for a general family of discrete {it interfering binary mixtures} by showing that they exhibit a "clustering property' at high density and not at low density. The clustering property states that there will be a region that has very high area, very small perimeter, and high density of one type of molecule. Special cases of interfering binary mixtures include the Ising model at fixed magnetization and independent sets.

APA, Harvard, Vancouver, ISO, and other styles

39

Prellberg, Thomas. "Maps of intervals with indifferent fixed points: thermodynamic formalism and phase transitions." Diss., Virginia Tech, 1991. http://hdl.handle.net/10919/39862.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Codina, Sala Joan. "Activity Mediated Interactions in Soft Matter. Structure, Interactions, and Phase Transitions." Doctoral thesis, Universitat de Barcelona, 2018. http://hdl.handle.net/10803/663988.

Full text

Abstract:

In this thesis we asses the phenomena of arising interactions in soft matter in coexistence with soft active matter. As a non-equilibrium bath we introduce ensembles of self-propelled particles, granular shaken beds, and photo active catalytic particles. We start the thesis with a detailed study of the widely used Active Brownian Particle (ABP) model. This model exhibits a non-equilibrium phase transition which has been intensively studied in recent years, we have finally reported that this transition satisfies all features of equilibrium first order phase transitions. Then, we introduce aligning interactions in ABP and characterize the emergent collective phenomena. In parallel, we explore the emergent forces, from mechanical contact forces, in probe particles in suspensions of aligning active particles and horizontally shaken granular beds. We characterize the forces and identify the emergence of long range interactions in both systems, in aligning active particles long range attractive interactions appear as alignment is increased, and in granular shaken media when the pair of particles align in the shaking direction. Finally, we conclude this thesis with the study of emergent interactions in spherically symmetric systems of catalytic active particles. Symmetry does not permit such particles to propell but the symmetry is broken with the addition of neighboring particles. We model the pair interaction in terms of the relative velocity between particles, and proceed to explore the emergent structures in mixtures of catalytic magnetic particles, and passive particles. We have unveiled the formation of clusters of passive particles. The addition of magnetic interactions between active particles leads to the formation of ramified gel-like structures for dense configurations of active particles. In this case, experimentalists have checked the formation of structures with the same morphologies in experiments in the laboratory.<br>En aquesta tesi abordem el fenomen de les interaccions emergents en matèria tova en coexistència amb matèria tova activa. Com a sistemes de matèria tova activa introduïm col·lectius de partícules autopropulsades, col·loides amb capacitat de catalitzar productes químics i medis granulars agitats. Primer de tot estudiem en detall un model molt estès per a partícules actives, el model de les partícules actives brownianes (ABP). D'aquest model estudiem amb detall una transició de fase de no equilibri i comprovem que la transició satisfà amb les característiques d'una transició en equilibri de primer ordre. Seguidament incorporem interaccions d'alineació en el model de partícules actives i procedim a estudiar les propietats col·lectives de les suspensions de partícules actives amb alineació. Per tal d'abordar l'objectiu de la tesi introduïm partícules de prova en suspensions de partícules actives, i en medis granulars amb forçament periòdic horitzontal, amb diferents paràmetres d'activitat per tal d'estudiar les forces, des d'un punt de vista mecànic, que emergeixen entre les parelles. Hem caracteritzat les forces i hem identificat l'aparició d'interaccions de llarg abast per sistemes de partícules amb alineació i en sistemes granulars en la direcció del forçament. Finalment, tanquem la tesi amb l'estudi i modelització d'interaccions emergents per a partícules catalítiques amb simetria esfèrica. La simetria no permet a les partícules d'autopropulsar-se però la presència de partícules al seu entorn sí que dóna lloc a interaccions, en forma de velocitats induïdes. Amb un model raonable de la interacció a distància hem calibrat la magnitud de la interacció amb sistemes experimentals i procedit a caracteritzar les estructures emergents per a mescles de partícules actives i passives que van des de la formació d'agregats en forma de clústers. L'addició d'interaccions magnètiques entre partícules actives permet la formació d'estructures ramificades de tipus gel. En aquest cas l'equip experimental ha pogut comparar l'aparició d'estructures amb les mateixes característiques al laboratori.

APA, Harvard, Vancouver, ISO, and other styles

41

Zhang, Yan. "Weakly first-order phase transitions : [epsilon] expansion vs. numerical simulation /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/9715.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Valba, Olga. "Statistical analysis of networks and biophysical systems of complex architecture." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00919606.

Full text

Abstract:

Complex organization is found in many biological systems. For example, biopolymers could possess very hierarchic structure, which provides their functional peculiarity. Understating such, complex organization allows describing biological phenomena and predicting molecule functions. Besides, we can try to characterize the specific phenomenon by some probabilistic quantities (variances, means, etc), assuming the primary biopolymer structure to be randomly formed according to some statistical distribution. Such a formulation is oriented toward evolutionary problems.Artificially constructed biological network is another common object of statistical physics with rich functional properties. A behavior of cells is a consequence of complex interactions between its numerous components, such as DNA, RNA, proteins and small molecules. Cells use signaling pathways and regulatory mechanisms to coordinate multiple processes, allowing them to respond and to adapt to changing environment. Recent theoretical advances allow us to describe cellular network structure using graph concepts to reveal the principal organizational features shared with numerous non-biological networks.The aim of this thesis is to develop bunch of methods for studying statistical and dynamic objects of complex architecture and, in particular, scale-free structures, which have no characteristic spatial and/or time scale. For such systems, the use of standard mathematical methods, relying on the average behavior of the whole system, is often incorrect or useless, while a detailed many-body description is almost hopeless because of the combinatorial complexity of the problem. Here we focus on two problems.The first part addresses to statistical analysis of random biopolymers. Apart from the evolutionary context, our studies cover more general problems of planar topology appeared in description of various systems, ranging from gauge theory to biophysics. We investigate analytically and numerically a phase transition of a generic planar matching problem, from the regime, where almost all the vertices are paired, to the situation, where a finite fraction of them remains unmatched.The second part of this work focus on statistical properties of networks. We demonstrate the possibility to define co-expression gene clusters within a network context from their specific motif distribution signatures. We also show how a method based on the shortest path function (SPF) can be applied to gene interactions sub-networks of co-expression gene clusters, to efficiently predict novel regulatory transcription factors (TFs). The biological significance of this method by applying it on groups of genes with a shared regulatory locus, found by genetic genomics, is presented. Finally, we discuss formation of stable patters of motifs in networks under selective evolution in context of creation of islands of "superfamilies".

APA, Harvard, Vancouver, ISO, and other styles

43

Liarte, Danilo Barbosa. "Modelos estatísticos de campo médio para vidros de spins e fluidos complexos." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-29092011-144333/.

Full text

Abstract:

Estudamos nesta tese três sistemas desordenados distintos das áreas de vidros de spins e fluidos complexos, por meio de modelos estatísticos no contexto da aproximação de campo médio. Analisamos os efeitos da inclusão de graus de liberdade elásticos sobre o diagrama de fases do modelo de Sherrington-Kirkpatrick, que é a versão de campo médio de um modelo popular de vidros de spins, paradigmas de sistemas com desordem temperada. Analisamos em seguida alguns problemas típicos da física dos fluidos complexos. Investigamos o diagrama de fases de um modelo de Maier-Saupe (MS), que é uma espécie de arquétipo das transições nemáticas, numa versão de rede muito simples, denominada modelo de Maier-Saupe-Zwanzig (MSZ), com a introdução de uma variável binária de desordem para representar uma mistura de discos e cilindros. Mostramos que o aparecimento de uma fase nemática biaxial, termodinamicamente estável, que tem sido intensamente procurada na literatura, depende da forma de tratamento das variáveis de desordem. Finalmente, utilizamos o modelo MSZ, na presença de termos elásticos não lineares e de elementos de desordem, a fim de reproduzir diversas características do comportamento termodinâmico dos elastômeros nemáticos, novos materiais poliméricos, com propriedades dos cristais líquidos nemáticos e das borrachas, tema de grande interesse na física da matéria mole.<br>We study three distinct disordered systems in the areas of spin glasses and complex fluids, by means of mean-field statistical models. We first analyze the effects of compressibility on the phase diagram of the Sherrington-Kirkpatrick model, a mean-field version of a popular model of spin glasses, which are paradigmatic examples of systems with quenched disorder. We then analyze some typical problems in the area of physics of complex fluids. We investigate the phase diagram of a Maier-Saupe model (MS), which is a sort of archetype of nematic transitions, in a simple lattice version called Maier-Saupe-Zwanzig model (MSZ), with the introduction of a binary variable of disorder to mimic a mixture of rod-like and plate-like mesogens. We show that the emergence of a stable nematic biaxial phase, which has been intensely pursued in the literature, depends on the form of treatment of the disorder variables. Finally, we use the MSZ model, in the presence of non-linear elastic terms and elements of disorder, to reproduce several aspects of the thermodynamic behavior of nematic elastomers, new polymeric materials with the properties of liquid crystals and rubber, and of great importance in the area of soft-matter physics.

APA, Harvard, Vancouver, ISO, and other styles

44

Haga, Taiki. "Renormalization Group Analysis of Nonequilibrium Phase Transitions in Driven Disordered Systems." Kyoto University, 2018. http://hdl.handle.net/2433/232230.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Wang, Jiong. "Analytical studies on the force-induced phase transitions in slender shape memory alloy cylinders layers /." access full-text access abstract and table of contents, 2009. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?phd-ma-b23750546f.pdf.

Full text

Abstract:

Thesis (Ph.D.)--City University of Hong Kong, 2009.<br>"Submitted to Department of Mathematics in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references (leaves [214]-224)

APA, Harvard, Vancouver, ISO, and other styles

46

Nikolaou, Marios. "A Matter of Disorder : Monte Carlo Simulations of Phase Transitions in Strongly Disordered Systems." Doctoral thesis, Stockholm : Royal Institute of Technology, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4313.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Siebert, Julien. "Statistical mechanics of the self-gravitating gases." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2005. http://tel.archives-ouvertes.fr/hal-00009142.

Full text

Abstract:

The self-gravitating systems are formed by particles interacting through gravity. They describe structure formation in the universe. As a consequence of the long range interaction of gravity, they are inhomogeneous even at thermal equilibrium. We study the self-gravitating systems with several kinds of particles and the self-gravitating systems in the presence of the cosmological constant $ Lambda$. We formulate the statistical mechanics and the mean field approach describing the gaseous phase. We explicitely compute the density of particles and thermodynamic quantities. The presence of $ Lambda$ extends the domain of stability of the gaseous phase. Monte Carlo simulations show that the mean field describes the gaseous phase with an excellent accuracy. Scalling law of the self-gravitating systems with several kinds of particles is found. At the critical point the fractal dimension is independant of their composition and is $1.6...$~.

APA, Harvard, Vancouver, ISO, and other styles

48

Spies, Ruben Daniel. "Mathematical modelling, finite dimensional approximations and sensitivity analysis for phase transitions in shape memory alloys." Diss., This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-06062008-165948/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Botelho, Sergio S. "BCS-to-BEC Quantum Phase Transition in High-Tc Superconductors and Fermionic Atomic Gases: A Functional Integral Approach." Diss., Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-09112005-172505/.

Full text

Abstract:

Thesis (Ph. D.)--Physics, Georgia Institute of Technology, 2006.<br>Tetali, Prasad, Committee Member ; First, Phillip, Committee Member ; Sa de Melo, Carlos, Committee Chair ; Zangwill, Andrew, Committee Member ; Kennedy, Brian, Committee Member. Includes bibliographical references.

APA, Harvard, Vancouver, ISO, and other styles

50

Nikolayev, Vadim. "Dynamique de systèmes physiques aux transitions de phase et interfaces libres." Habilitation à diriger des recherches, Université Pierre et Marie Curie - Paris VI, 2005. http://tel.archives-ouvertes.fr/tel-00011286.

Full text

Abstract:

Cette thèse décrit les études théoriques de deux catégories de phénomènes physiques: les transitions de phase et l'hydrodynamique physique. Dans la première catégorie se rangent plusieurs phénomènes ayant lieu dans des solides et dans des fluides. Les solides considérés sont des cristaux non-stoechiométriques supraconducteurs à haute température critique qui présentent des structures périodiques à période longue. Pour les fluides, on s'intéresse surtout à la cinétique des transitions de phase: il s'agit de la séparation de phase dans des mélanges binaires liquides, de l'ébullition et enfin de la condensation naturelle (rosée ou buée). La deuxième catégorie inclut la modélisation du mouvement de la ligne triple de contact liquide-gaz-solide le long d'un substrat hétérogène ainsi que l'analyse de l'instabilité d'une couche liquide placée dans le champ électrique.

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!