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A Dynamic and Thermodynamic Approach to Complexity.

Description: The problem of establishing the correct approach to complexity is a very hot and crucial issue to which this dissertation gives some contributions. This dissertation considers two main possibilities, one, advocated by Tsallis and co-workers, setting the foundation of complexity on a generalized, non-extensive , form of thermodynamics, and another, proposed by the UNT Center for Nonlinear Science, on complexity as a new condition that, for physical systems, would be equivalent to a state of matter intermediate between dynamics and thermodynamics. In the first part of this dissertation, the concept of Kolmogorov-Sinai entropy is introduced. The Pesin theorem is generalized in the formalism of Tsallis non-extensive thermodynamics. This generalized form of Pesin theorem is used in the study of two major classes of problems, whose prototypes are given by the Manneville and the logistic map respectively. The results of these studies convince us that the approach to complexity must be made along lines different from those of the non-extensive thermodynamics. We have been convinced that the Lévy walk can be used as a prototype model of complexity, as a condition of balance between order and randomness that yields new phenomena such as aging, and multifractality. We reach the conclusions that these properties must be studied within a dynamic rather than thermodynamic perspective. The second part focuses on the study of the heart beating problem using a dynamic model, the so-called memory beyond memory, based on the Lévy walker model. It is proved that the memory beyond memory effect is more obvious in the healthy heart beating sequence. The concepts of fractal, multifractal, wavelet transformation and wavelet transform maximum modulus (WTMM) method are introduced. Artificial time sequences are generated by the memory beyond memory model to mimic the heart beating sequence. Using WTMM method, the multifratal singular spectrums of the sequences ...
Date: August 2003
Creator: Yang, Jin
Partner: UNT Libraries

The Current Status of Fusion Reactor Blanket Thermodynamics

Description: The available thermodynamic information is reviewed for three categories of materials that meet essential criteria for use as breeding blankets in deuterium-tritium (D-T) fueled fusion reactors: liquid lithium, solid lithium alloys, and lithium-containing ceramics. The leading candidate, liquid lithium, which also has potential for use as a coolant, has been studied more extensively than have the solid alloys or ceramics.
Date: April 1979
Creator: Veleckis, E.; Yonco, R. M. & Maroni, V. A.
Partner: UNT Libraries Government Documents Department

Thermodynamic Diagrams for Sodium

Description: From abstract: This paper presents temperature-entropy and Mollier charts for sodium, and describes briefly the method used for their construction, based upon data from the literature.
Date: July 13, 1950
Creator: Inatomi, T. H. & Parrish, W. C.
Partner: UNT Libraries Government Documents Department

Thermodynamic Properties of Nonelectrolyte Solutes in Ternary Solvent Mixtures

Description: The purpose of this dissertation is to investigate the thermodynamic properties of nonelectrolyte solutes dissolved in ternary solvent mixtures, and to develop mathematical expressions for predicting and describing that behavior in the solvent mixtures. Thirty-four ternary solvent systems were studied containing either alcohol (1-propanol, 2-propanol, 1-butanol, and 2-butanol), alkane (cyclohexane, heptane, and 2,2,4-trimethylpentane) or alkoxyalcohol (2-ethoxyethanol and 2-butoxyethanol) cosolvents. Approximately 2500 experimental measurements were performed. Expressions were derived from the Combined Nearly Ideal Multiple Solvent (NIMS)/Redlich-Kister, the Combined Nearly Ideal Multiple Solvent (NIMS)/Bertrand, Acree and Burchfield (BAB) and the Modified Wilson models for predicting solute solubility in ternary solvent (or even higher multicomponent) mixtures based upon the model constants calculated from solubility data in sub-binary solvents. Average percent deviation between predicted and observed values were less than 2%, documenting that these models provide a fairly accurate description of the thermodynamic properties of nonelectrolyte solutions. Moreover, the models can be used for solubility prediction in solvent mixtures in order to find the optimum solvent composition for solubilization or desolubilization of a solute. From a computational standpoint, the Combined Nearly Ideal Multiple Solvent/Redlich-Kister equation is preferred because the needed model constants can be calculated with a simple linear regressional analysis. Model constants for the Modified Wilson equation had to be calculated using a reiterative trial-and-error method. The C++ program for the Modified Wilson equation applied to ternary and heptanary solvent mixtures is attached.
Date: August 1999
Creator: Deng, Tʻai-ho
Partner: UNT Libraries

Compiled Thermodynamic Data Sources for Aqueous and Biochemical Systems: an Annotated Bibliography (1930-1983)

Description: Abstract: This is a selected and annotated bibliography of sources of compiled and evaluated chemical thermodynamic data relevant to biochemical and aqueous systems. The principal thermodynamic properties considered herein are Gibbs energy and equilibrium data, enthalpies of formation and reaction, heat capacities and entropies, and the corresponding partial molar and excess properties. Derived quantities used in calculating the above are also included. Transport and mechanical data have also been identified to a lesser degree. Included in the annotations to the data sources are brief descriptions of the types of properties tabulated, the classes of materials dealt with, and the degree of completeness of the compilations.
Date: December 1984
Creator: Goldberg, Robert N.
Partner: UNT Libraries Government Documents Department

A Bibliography of Sources of Thermodynamic Data for the Systems: CO₂+NH₃+H₂O, CO₂+H₂S+H₂O, H₂S+NH₃+H₂O, and CO₂+NH₃+H₂S+H₂O

Description: Abstract: Contained herein is a bibliography of sources of experimental and correlated thermodynamic data for the systems: CO₂ + NH₃ + H₂O, CO₂ + H₂S + H₂O, H₂S + NH₃ + H₂O, and CO₂ + NH₃ + H₂S + H₂O. The types of data in this bibliography include all types of equilibrium data, including both eqilibria [sic] in solution and vapor-liquid equilibrium data, enthalpies, heat capacities, and densities. There are 215 references cited. Bibliographic Data Sheet.
Date: May 1985
Creator: Goldberg, Robert N. & Steckler, D. K.
Partner: UNT Libraries Government Documents Department

Bibliographies of Industrial Interest : Thermodynamic Measurements on the Systems CO₂-H₂O, CuCl₂-H₂0,H₂SO₄-H₂O, NH₃-H₂O, H₂S-H₂O, ZnCl₂-H₂Oand H₃PO₄-H₂O

Description: Abstract: Contained herein are bibliographies of Sources of experimental and correlated thermodynamic data for seven binary aqueous mixtures of industrial importance, namely mixtures of CO2, H2S, NH3, H2S0, H3P4, CuCl2 and ZnCl2 with water. The categories of equilibrium data included in the bibliographies are activity and osmotic coefficients, equilibria in solution, enthalpies and heat capacity data, vapor-liquid equilibria, and phase equilibrium data.
Date: September 1986
Creator: Staples, B. R.
Partner: UNT Libraries Government Documents Department

Microscopic Foundations of Thermodynamics and Generalized Statistical Ensembles

Description: This dissertation aims at addressing two important theoretical questions which are still debated in the statistical mechanical community. The first question has to do with the outstanding problem of how to reconcile time-reversal asymmetric macroscopic laws with the time-reversal symmetric laws of microscopic dynamics. This problem is addressed by developing a novel mechanical approach inspired by the work of Helmholtz on monocyclic systems and the Heat Theorem, i.e., the Helmholtz Theorem. By following a line of investigation initiated by Boltzmann, a Generalized Helmholtz Theorem is stated and proved. This theorem provides us with a good microscopic analogue of thermodynamic entropy. This is the volume entropy, namely the logarithm of the volume of phase space enclosed by the constant energy hyper-surface. By using quantum mechanics only, it is shown that such entropy can only increase. This can be seen as a novel rigorous proof of the Second Law of Thermodynamics that sheds new light onto the arrow of time problem. The volume entropy behaves in a thermodynamic-like way independent of the number of degrees of freedom of the system, indicating that a whole thermodynamic-like world exists at the microscopic level. It is also shown that breaking of ergodicity leads to microcanonical phase transitions associated with nonanalyticities of volume entropy. The second part of the dissertation deals with the problem of the foundations of generalized ensembles in statistical mechanics. The starting point is Boltzmann's work on statistical ensembles and its relation with the Heat Theorem. We first focus on the nonextensive thermostatistics of Tsallis and the associated deformed exponential ensembles. These ensembles are analyzed in detail and proved (a) to comply with the requirements posed by the Heat Theorem, and (b) to interpolate between canonical and microcanonical ensembles. Further they are showed to describe finite systems in contact with finite heat baths. ...
Date: May 2008
Creator: Campisi, Michele
Partner: UNT Libraries

Thermodynamical Formalism

Description: Thermodynamical formalism is a relatively recent area of pure mathematics owing a lot to some classical notions of thermodynamics. On this thesis we state and prove some of the main results in the area of thermodynamical formalism. The first chapter is an introduction to ergodic theory. Some of the main theorems are proved and there is also a quite thorough study of the topology that arises in Borel probability measure spaces. In the second chapter we introduce the notions of topological pressure and measure theoretic entropy and we state and prove two very important theorems, Shannon-McMillan-Breiman theorem and the Variational Principle. Distance expanding maps and their connection with the calculation of topological pressure cover the third chapter. The fourth chapter introduces Gibbs states and the very important Perron-Frobenius Operator. The fifth chapter establishes the connection between pressure and geometry. Topological pressure is used in the calculation of Hausdorff dimensions. Finally the sixth chapter introduces the notion of conformal measures.
Date: August 2004
Creator: Chousionis, Vasileios
Partner: UNT Libraries

Thermodynamic Calculations Relating to Chloride Volatility Processing of Nuclear Fuels: [Part] 2. The Capacity of Chlorine for Transporting Plutonium Tetrachloride Vapor During Reaction of U3O8-PuO2 with Carbon Tetrachloride

Description: Report issued by the Oak Ridge National Laboratory discussing thermodynamic calculations of nuclear fuels. As stated in the introduction, "the equations developed in this report could be used to calculate the capacity of chlorine for transporting plutonium tetrachloride" (p. 2). This report includes tables, and illustrations.
Date: October 1964
Creator: Gens, T. A.
Partner: UNT Libraries Government Documents Department

Electronic Distribution Functions and Thermodynamic Properties at High Temperatures

Description: Report issued by the Argonne National Laboratory discussing the thermodynamics and electronic distribution of high temperatures. As stated in the introduction, "in the present paper, a model for computing is described which takes into account in detail the interactions between bound electrons and the average interaction of the bound electrons with the free ones" (p. 4). This report includes tables, and illustrations.
Date: May 1953
Creator: Brachman, Malcolm K. & Meyerott, Roland E.
Partner: UNT Libraries Government Documents Department

Dynamics, Thermodynamic formalism and Perturbations of Transcendental Entire Functions of Finite Singular Type

Description: In this dissertation, we study the dynamics, fractal geometry and the topology of the Julia set of functions in the family H which is a set in the class S, the Speiser class of entire transcendental functions which have only finitely many singular values. One can think of a function from H as a generalized expanding function from the cosh family. We shall build a version of thermodynamic formalism for functions in H and we shall show among others, the existence and uniqueness of a conformal measure. Then we prove a Bowen's type formula, i.e. we show that the Hausdorff dimension of the set of returning points, is the unique zero of the pressure function. We shall also study conjugacies in the family H, perturbation of functions in the family and related dynamical properties. We define Perron-Frobenius operators for some functions naturally associated with functions in the family H and then, using fundamental properties of these operators, we shall prove the important result that the Hausdorff dimension of the subset of returning points depends analytically on the parameter taken from a small open subset of the n-dimensional parameter space.
Date: May 2005
Creator: Coiculescu, Ion
Partner: UNT Libraries

ANL/HTP: A Computer Code for the Simulation of Heat Pipe Operation

Description: ANL/HTP is a computer code for the simulation of heat pipe operation, to predict heat pipe performance and temperature distributions during steady state operation. Source and sink temperatures and heat transfer coefficients can be set as input boundary conditions, and varied for parametric studies. Five code options are included to calculate performance for fixed operating conditions, or to vary any one of the four boundary conditions to determine the heat pipe limited performance. The performance limits included are viscous, sonic, entrainment capillary, and boiling, using the best available theories to model these effects. The code has built-in models for a number of wick configurations - open grooves, screen-covered grooves, screen-wrap, and arteries, with provision for expansion. The current version of the code includes the thermophysical properties of sodium as the working fluid in an expandable subroutine. The code-calculated performance agrees quite well with measured experiment data.
Date: November 1983
Creator: McLennan, G. A.
Partner: UNT Libraries Government Documents Department

Electronic Transport Properties in Copper Oxides

Description: Oxidation of copper and electronic transport in thermally grown large-grain poly-crystals of non-stoichiometric copper oxides were studied at elevated temperatures. Thermogravimetric copper oxidation was studied in air and oxygen at temperatures between 350 and 100 C. From the temperature-dependence of oxidation rates, three different processes can be identified for the oxidation of copper: bulk diffusion, grain-boundary diffusion, and surface control with whisker growth; these occur at high, intermediate, and low temperatures, respectively. Electrical conductivity measurements as a function of temperature (350 - 1134 C) and pO2 (10(sup⁻⁸-1.0 atm) indicated intrinsic electronic conduction in CuO over the entire range of conditions. Electronic behavior of non-stoichiometric Cu(sub 2)O indicates that the charge defects are doubly ionized oxygen interstitials and holes. The calculated enthalpy of formation of oxygen ((Delta)H(sub O(sub 2))) and the hole conduction energy (E(sub H)) at constant composition for non-stoichiometric Cu2O are 2.0 (plus minus) 0.2 eV and 0.82 (plus minus) 0.02 eV, respectively.
Date: July 1991
Creator: Park, J.-H. & Natesan, K.
Partner: UNT Libraries Government Documents Department

Corrosion and Mechanical Behavior of Materials for Coal Gasification Applications

Description: A state-of-the-art review is presented on the corrosion and mechanical behavior of materials at elevated temperatures in coal-gasification environments. The gas atmosphere in coal-conversion processes are, in general, complex mixtures which contain sulfur-bearing components (hydrogen sulfide, SO2, and COS) as well as oxidants (carbon dioxide/carbon monoxide and water/hydrogen). The information developed over the last five years clearly shows sulfidation to be the major mode of material degradation in these environments. The corrosion behavior of structural materials in complex gas environments is examined to evaluate the interrelationships between gas chemistry, alloy chemistry, temperature, and pressure. Thermodynamic aspects of high-temperature corrosion processes that pertain to coal conversion are discussed, and kinetic data are used to compare the behavior of different commercial materials of interest. The influence of complex gas environments on the mechanical properties such as tensile, stress-rupture, and impact on selected alloys is presented. The data have been analyzed, wherever possible, to examine the role of environment on the property variation. The results from ongoing programs on char effects on corrosion and on alloy protection via coatings, cladding, and weld overlay are presented. Areas of additional research with particular emphasis on the development of a better understanding of corrosion processes in complex environments and on alloy design for improved corrosion resistance are discussed.
Date: May 1980
Creator: Natesan, K.
Partner: UNT Libraries Government Documents Department

COMMIX-SA-1: a Three-Dimensional Thermohydrodynamic Computer Program for Solar Applications

Description: COMMIX-SA-1 is a three-dimensional, transient, single-phase, compressible-flow, component computer program for thermohydrodynamic analysis. It was developed for solar applications in general, and for analysis of thermocline storage tanks in particular. The conservation equations (in cylindrical coordinates) for mass, momentum, and energy are solved as an initial-boundary-value problem. The detailed numerical-solution procedure based on a modified ICE (Implicit Continuous-Fluid Eulerian) technique is described. A method for treating the singularity problem arising at the origin of a cylindrical-coordinate system is presented. In addition, the thermal interactions between fluid and structures (tank walls, baffles, etc.) are explicitly accounted for. Finally, the COMMIX-SA-1 code structure is delineated, and an input description and sample problems are presented.
Date: November 1980
Creator: Sha, W. T.; Lin, E. I. H.; Schmitt, R. C.; Liu, K. V.; Hull, J. R.; Oras, J. J. et al.
Partner: UNT Libraries Government Documents Department

Thermal-Performance Study of Liquid Metal Fast Breeder Reactor Insulation

Description: Three types of metallic thermal insulation were investigated analytically and experimentally: multilayer reflective plates, multilayer honeycomb composite, and multilayer screens. Each type was subjected to evacuated and non-evacuated conditions, where thermal measurements were made to determine thermal-physical characteristics. A variation of the separation distance between adjacent reflective plates of multilayer reflective plates and multilayer screen insulation was also experimentally studied to reveal its significance. One configuration of the multilayer screen insulation was further selected to be examined in sodium and sodium oxide environments. The emissivity of Type 304 stainless steel used in comprising the insulation was measured by employing infrared technology. A comprehensive model was developed to describe the different proposed types of thermal insulation. Various modes of heat transfer inherent in each type of insulation were addressed and their relative importance compared. Provision was also made in the model to allow accurate simulation of possible sodium and sodium oxide contamination of the insulation. The thermal-radiation contribution to heat transfer in the temperature range of interest for LMFBR's was found to be moderate, and the suppression of natural convection within the insulation was vital in preserving its insulating properties. Experimental data were compared with the model and other published results. Moreover, the three proposed test samples were assessed and compared under various conditions as viable LMFBR thermal insulations.
Date: September 1980
Creator: Shiu, Kelvin Kwok-Kay
Partner: UNT Libraries Government Documents Department