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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Statistical thermodynamics of vacancies in binary alloys

Schapink, Frederik Willem. January 1900 (has links)
Proefschrift--Delft. / Summary in Dutch. "Stallingen": [4] p. inserted. Bibliography: p. 131-132.
2

Theoretical investigations of DNA structure and dynamics

Harris, Sarah Anne January 2001 (has links)
No description available.
3

Thermodynamic functions for halogenated benzenes

Butler, Jeremy Bruford January 1967 (has links)
The availability of molecular structural and spectrographic data has enabled the calculation of the ideal gas thermodynamic functions [formula omitted] for thirty eight halogenated benzenes. The thermodynamic functions are given for temperatures between 273.15° K. and 1500° K., at one atmosphere. The contribution of the anharmonicity effect to the thermodynamic properties is discussed. Additionally, a method is described for making real gas corrections to the ideal gas thermodynamic functions, however, only over a limited range of pressure and temperature (15 atm. to 0.25 atm. 273.15° K. to 1000° K.). This method, based on the Berthelot equation of state, requires the critical temperature and pressure, which are summarised in this work for several of the halogenated benzenes. As an example of the method, the real gas thermodynamic functions for fluorobenzene are shown, at pressures between 10 atm. and 0.25 atm. Finally the thermal stability of the halogenated benzenes is discussed and the temperatures over which the ideal gas thermodynamic functions are applicable are indicated. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate
4

Gene regulation in the lac operon

Patterson, Kathryn Grace. January 2009 (has links) (PDF)
Thesis (PhD)--Montana State University--Bozeman, 2009. / Typescript. Chairperson, Graduate Committee: Tomas Gedeon. Includes bibliographical references (leaves 118-125).
5

Statistical thermodynamics of cluster formation in dilute colloidal and coarse-grained protein solutions

Young, Teresa Marie. January 2010 (has links)
Thesis (Ph.D.)--University of Delaware, 2009. / Principal faculty advisor: Christopher J. Roberts, Dept. of Chemical Engineering. Includes bibliographical references.
6

The statistical thermodynamics of equilibrium

January 1963 (has links)
[by] Laszlo Tisza, Paul M. Quay. / Repr. from Annals of physics. v. 25, no. 1. Oct. 1963.
7

Non-equilibrium quantum dynamics of condensed matter models.

Sewran, Sashwin. January 2013 (has links)
In this dissertation, we studied the generation of squeezed states induced by a timedependent interaction and the in uence of temperature on the strength of the squeezing in a condensed matter model. The model studied comprised two quantum harmonic oscillators, with a time-dependent, non-linear coupling between them. The in uence of the thermal bath on the non-equilibrium dynamics of the model was represented in terms of non-Hamiltonian thermostats and a collection of independent harmonic oscillators with Ohmic spectral density. The equations of motion were studied in the Wigner representation, which introduces a phase space description for the model. The representation of the system in quantum phase space allowed us to investigate the di erence between purely classical evolution and the relative importance of quantum corrections with respect to the dynamics. The dynamics was studied by means of computer simulation techniques. The numerical simulation of the non-equilibrium statistical mechanics of both time-dependent and non-linear interactions allowed us to investigate conditions beyond those in recent literature [1, 2]. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.
8

Automation of a static-synthetic apparatus for vapour-liquid equilibrium measurement.

Moodley, Kuveneshan. January 2012 (has links)
The measurement of vapour-liquid equilibrium data is extremely important as such data are crucial for the accurate design, simulation and optimization of the majority of separation processes, including distillation, extraction and absorption. This study involved the measurement of vapour-liquid equilibrium data, using a modified version of the static total pressure apparatus designed within the Thermodynamics Research Unit by J.D. Raal and commissioned by Motchelaho, (Motchelaho, 2006 and Raal et al., 2011). This apparatus provides a very simple and accurate means of obtaining P-x data using only isothermal total pressure and overall composition (z) measurements. Phase sampling is not required. Phase equilibrium measurement procedures using this type of apparatus are often tedious, protracted and repetitive. It is therefore useful and realizable in the rapidly advancing digital age, to incorporate computer-aided operation, to decrease the man hours required to perform such measurements. The central objective of this work was to develop and implement a control scheme, to fully automate the original static total pressure apparatus of Raal et al. (2011). The scheme incorporates several pressure feedback closed loops, to execute process step re-initialization, valve positioning and motion control in a stepwise fashion. High resolution stepper motors were used to engage the dispensers, as they provided a very accurate method of regulating the introduction of precise desired volumes of components into the cell. Once executed, the control scheme requires approximately two days to produce a single forty data points (P-x) isotherm, and minimizes human intervention to two to three hours. In addition to automation, the apparatus was modified to perform moderate pressure measurements up to 1.5 MPa. Vapour-liquid equilibrium test measurements were performed using both the manual and automated operating modes to validate the operability and reproducibility of the apparatus. The test systems measured include the water (1) + propan-1-ol (2) system at 313.15 K and the n-hexane (1) + butan- 2-ol system at 329.15 K. Phase equilibrium data of binary systems, containing the solvent morpholine-4-carbaldehyde (NFM) was then measured. The availability of vapour-liquid equilibrium data for binary systems containing NFM is limited in the literature. The new systems measured include: n-hexane (1) + NFM (2) at 343.15, 363.15 and 393.15 K, as well as n-heptane (1) + NFM (2) at 343.15, 363.15 and 393.15 K. The modified apparatus is quite efficient as combinations of the slightly volatile NFM with highly volatile alkane constituents were easily and accurately measured. The apparatus also allows for accurate vapour-liquid equilibrium measurements in the dilute composition regions. A standard uncertainty in the equilibrium pressure reading, within the 0 to 100 kPa range was calculated to be 0.106 kPa, and 1.06 kPa for the 100 to 1000 kPa pressure range. A standard uncertainty in the equilibrium temperature of 0.05 K was calculated. The isothermal data obtained were modelled using the combined (-) method described by Barker (1953). This involved the calculation of binary interaction parameters, by fitting the data to various thermodynamic models. The virial equation of state with the Hayden-O’Connell (1975) and modified Tsonopoulos (Long et al., 2004) second virial coefficient correlations were used in this work to account for vapour phase non-ideality. The Wilson (1964), NRTL (Renon and Prausnitz, 1968), Tsuboka-Katayama-Wilson (1975) and modified Universal Quasi-Chemical (Anderson and Prausnitz, 1978) activity coefficient models were used to account for the liquid phase non-ideality. A stability analysis was carried out on all the new systems measured to ensure that two-liquid phase formation did not occur in the measured temperature range. A model-free method based on the numerical integration of the coexistence equation was also used to determine the vapour phase compositions and activity coefficients from the measured P-z data. These results compare well with the results obtained by the model-dependent method. The infinite dilution activity coefficients for the systems under consideration were determined by the method of Maher and Smith (1979b), and by suitable extrapolation methods. Excess enthalpy and excess entropy data were calculated for the systems measured, using the Gibbs-Helmholtz equation in conjunction with the fundamental excess property relation. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2012.
9

Applications of the direct correlation function solution theory to the thermodynamics of fluids and fluid mixtures.

Brelvi, Syed Waseem. January 1973 (has links)
Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Bibliography: leaves 187-190.
10

Extended Hydrodynamics Using the Discontinuous-Galerkin Hancock Method

Kaufmann, Willem 15 September 2021 (has links)
Moment methods derived from the kinetic theory of gases can be used for the prediction of continuum and non-equilibrium flows and offer numerical advantages over other methods, such as the Navier-Stokes model. Models developed in this fashion are described by first-order hyperbolic partial differential equations (PDEs) with stiff local relaxation source terms. The application of discontinuous-Galerkin (DG) methods for the solution of such models has many benefits. Of particular interest is the third-order accurate, coupled space-time discontinuous-Galerkin Hancock (DGH) method. This scheme is accurate, as well as highly efficient on large-scale distributed-memory computers. The current study outlines a general implementation of the DGH method used for the parallel solution of moment methods in one, two, and three dimensions on modern distributed clusters. An algorithm for adaptive mesh refinement (AMR) was developed alongside the implementation of the scheme, and is used to achieve even higher accuracy and efficiency. Many different first-order hyperbolic and hyperbolic-relaxation PDEs are solved to demonstrate the robustness of the scheme. First, a linear convection-relaxation equation is solved to verify the order of accuracy of the scheme in three dimensions. Next, some classical compressible Euler problems are solved in one, two, and three dimensions to demonstrate the scheme's ability to capture discontinuities and strong shocks, as well as the efficacy of the implemented AMR. A special case, Ringleb's flow, is also solved in two-dimensions to verify the order of accuracy of the scheme for non-linear PDEs on curved meshes. Following this, the shallow water equations are solved in two dimensions. Afterwards, the ten-moment (Gaussian) closure is applied to two-dimensional Stokes flow past a cylinder, showing the abilities of both the closure and scheme to accurately compute classical viscous solutions. Finally, the one-dimensional fourteen-moment closure is solved.

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