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Thermodynamics Commons

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Articles 91 - 110 of 110

Full-Text Articles in Thermodynamics

Scaling Properties At Freeze-Out In Relativistic Heavy-Ion Collisions, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, S. Bueltmann, I. Koralt, D. Plyku, Star Collaboration Jan 2011

Scaling Properties At Freeze-Out In Relativistic Heavy-Ion Collisions, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, S. Bueltmann, I. Koralt, D. Plyku, Star Collaboration

Physics Faculty Publications

Identified charged pion, kaon, and proton spectra are used to explore the system size dependence of bulk freeze-out properties in Cu+Cu collisions at √sNN=200 and 62.4 GeV. The data are studied with hydrodynamically motivated blast-wave and statistical model frameworks in order to characterize the freeze-out properties of the system. The dependence of freeze-out parameters on beam energy and collision centrality is discussed. Using the existing results from Au + Au and pp collisions, the dependence of freeze-out parameters on the system size is also explored. This multidimensional systematic study furthers our understanding of the QCD phase diagram revealing the importance …


Demonstration Of A Strategy To Perform Two-Dimensional Diode Laser Tomography, Ryan N. Givens Mar 2008

Demonstration Of A Strategy To Perform Two-Dimensional Diode Laser Tomography, Ryan N. Givens

Theses and Dissertations

Demonstration of a strategy to perform two-dimensional diode laser tomography using a priori knowledge from symmetry arguments and computational fluid dynamic (CFD) calculations is presented for a flat flame burner. The strategy uses an optimization technique to determine flame diameter and location using a vector quantization approach. Next, the variance in a training set, produced from CFD calculations, is captured using principal components analysis. The information in the training set allows interpolation between beam paths resulting in temperature and density maps. Finally, the TDLAS temperature and density maps are shown to agree with traditional thermocouple measurements of the flat flame …


Thermal Effectiveness Characteristics Of Low Approach Indirect Evaporative Cooling Systems In Buildings, Ben Costelloe, Donal Finn Jan 2007

Thermal Effectiveness Characteristics Of Low Approach Indirect Evaporative Cooling Systems In Buildings, Ben Costelloe, Donal Finn

Articles

Meteorological enthalpy analysis of temperate and maritime climates above latitude 45°N suggests that the water-side evaporative cooling technique has considerable unrealised potential with contemporary “high temperature” building cooling systems—such as chilled ceilings and displacement ventilation. As low approach conditions are the key to exploiting the cooling potential of the ambient air, thermal performance at such conditions needs to be investigated. To address the research issues, an industrial scale test rig, based on a low approach open cooling tower and plate heat exchanger and designed to maximise evaporative cooling potential, has been constructed. The thermal effectiveness of such systems (as a …


A Study Correlating Entropy Generation To Parameters Characterizing Thermal Comfort In A Conditioned Room, Sai Shrinivas Sreedharan Oct 2006

A Study Correlating Entropy Generation To Parameters Characterizing Thermal Comfort In A Conditioned Room, Sai Shrinivas Sreedharan

Mechanical & Aerospace Engineering Theses & Dissertations

Although significant advances have been made to analyze and study a room as an open thermodynamic system experiencing indoor airflow and heat exchanges with surroundings, studies incorporating entropy generation in the analysis have been sparse. This study focuses on correlating indoor thermal comfort with entropy generation, which hopefully will result in efficient utilization of energy supplied to the system. The problem that this thesis attempts to solve involves calculation of entropy production in conditioned space and its correlation to parameters that characterize thermal comfort. Thermal comfort in a conditioned space is governed by many thermal, mechanical and psychrometric parameters. The …


Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor Jun 2006

Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor

Tanzania Journal of Engineering and Technology (TJET)

This paper reports on a research project conducted with an objective of identifying and assessing various approaches used by different computer users (Management, System Administrators and end users) in Tanzania to combat computer viruses (CVs), and to assess users' awareness level on CVs. Specifically, the study aimed at assessing the awareness level on CVs to the Tanzanian business community; analyze the socio -economic impact caused by CVs in Tanzania and; assess existing methods, capacity and limitations on controlling CVs in Tanzania. Data was collected using both questionnaires and interview from financial institutions such as NBC and BOT, and telecommunications sector …


Review Of The Product Development Process And Information Flow In The Manufacturing Industry: Problems And A Possible Wav Forward, E Opiyo Jun 2004

Review Of The Product Development Process And Information Flow In The Manufacturing Industry: Problems And A Possible Wav Forward, E Opiyo

Tanzania Journal of Engineering and Technology (TJET)

No abstract provided.


Design And Simulation Of An Induction Skull Melting System, Taide Tan May 2004

Design And Simulation Of An Induction Skull Melting System, Taide Tan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Incorporating volatile actinides, mainly americium into a metallic fuel pin (MFP) has been a serious problem due to americium’s high vapor pressure. An Induction Skull Melting (ISM) system was identified by Argonne National Laboratory (ANL) as a potential furnace design to cast MFPs. Through the development of the ISM system, the nuclear waste feedstock can be melted and injected into the mold for fabricating MFPs in the advanced nuclear fuel cycles. The main phenomena in this system include: induction melting process, casting process and mass transfer process of americium. Issues related to ISM system design for casting MFPs are discussed …


Development Of A Model For Induction Heating, Randy Clarksean, Yitung Chen Jun 2002

Development Of A Model For Induction Heating, Randy Clarksean, Yitung Chen

Fuels Campaign (TRP)

There are two coupled equations that must be solved in order to determine the power deposition. The numerical solution of these equations is needed in order to apply a source term within the energy equations. These equations have previously solved in FIDAP. That implementation used modified versions of the momentum and energy equations to provide a mechanism for the solution of two coupled equations. Currently, we want to solve for the induction heating field in addition to the flow field and the energy equation. In order to do this, a mechanism has to be defined within FIDAP to solve these …


The Fission Properties Of Curium Separated From Spent Nuclear Fuel, William Culbreth, Elizabeth Bakker, Jason Viggato Apr 2002

The Fission Properties Of Curium Separated From Spent Nuclear Fuel, William Culbreth, Elizabeth Bakker, Jason Viggato

Separations Campaign (TRP)

Curium poses special problems in the chemical preparation of spent nuclear fuel for transmutation. Once separated from the other minor actinides, the seven curium isotopes in spent fuel can lead to nuclear fission with the subsequent release of a large amount of radiation. Several isotopes of curium also generate a significant amount of heat by radioactive decay. Sustained fission can be avoided by preventing the accumulation by more that a critical mass of curium. The heat generation of curium presents even more restriction on the mass of curium that can safely be contained in one location.

To analyze the nuclear …


Effects Of Concentration And Temperature On The Coupled Heat And Mass Transport In Liquid Mixtures, Yaşar Demirel, Stanley I. Sandler Mar 2001

Effects Of Concentration And Temperature On The Coupled Heat And Mass Transport In Liquid Mixtures, Yaşar Demirel, Stanley I. Sandler

Papers in Thermal Mechanics

Using published experimental data on the thermal conductivity, mutual diffusivity, and heats of transport, the degree of coupling between heat and mass flows has been calculated for binary and ternary nonideal liquid mixtures. The binary mixtures consist of two types: the first is six systems of six-to-eight-carbon straight and branched chain alkanes in chloroform and in carbon tetrachloride; and the second is mixtures of carbon tetrachloride with benzene, toluene, 2-propanone, n-hexane, and 11-octane. The ternary mixture considered is toluene-chlorobenzene-bromobenzene. The published data are available at 35°C, 30°C, and 35°C and ambient pressure. Using the linear nonequilibi-ium thermodynainics (LNET) and the …


Entropy Generation Method To Quantify Thermal Comfort, S. C. Boregowda, S. N. Tiwari, S. K. Chaturvedi Jan 2001

Entropy Generation Method To Quantify Thermal Comfort, S. C. Boregowda, S. N. Tiwari, S. K. Chaturvedi

Mechanical & Aerospace Engineering Faculty Publications

The present paper presents a thermodynamic approach to assess the quality of human-thermal environment interaction and quantify thermal comfort. The approach involves development of entropy generation term by applying second law of thermodynamics to the combined human-environment system. The entropy generation term combines both human thermal physiological responses and thermal environmental variables to provide an objective measure of thermal comfort. The original concepts and definitions form the basis for establishing the mathematical relationship between thermal comfort and entropy generation term. As a result of logic and deterministic approach, an Objective Thermal Comfort Index (OTCI) is defined and established as a …


Application Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Arton Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Art, Silas Kajuna Dec 1999

Application Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Arton Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Art, Silas Kajuna

Tanzania Journal of Engineering and Technology (TJET)

Vibration is one of the techniques employed in the determination of dynamic properties of fruits and vegetables. It entails generation of a mechanical or acoustic vibrational signal which is propagated through the flesh of the agricultural material. A transducer is either attached or held close to the specimen to monitor the propagation of the signal through the specimen. The manner in which the signal is transmitted through the material is analyzed, and the dynamic properties of the specimen which relate to its firmness or its internal being are derived. The technique has been around for the past 30 years or …


Droplet Evaporation And Deformations In An Amplitude Modulated Ultrasonic Field, Nihad E. Daidzic, Rene Stadler, Adrian Melling Apr 1996

Droplet Evaporation And Deformations In An Amplitude Modulated Ultrasonic Field, Nihad E. Daidzic, Rene Stadler, Adrian Melling

Aviation Department Publications

The aim of the report presented is the measurements of droplet oscillations.


Electrostatic Positioning Of Droplets In Turbulent Flows (Lstm 375/Te/93), Nihad E. Daidzic, Adrian Melling Apr 1993

Electrostatic Positioning Of Droplets In Turbulent Flows (Lstm 375/Te/93), Nihad E. Daidzic, Adrian Melling

Aviation Department Publications

Report LSTM 375/TE/93, Lehrstuhl fuer Stroemungsmechanik Universitaet Erlangen-Nuernberg Cauerstr. 4, 8520 Erlangen Germany.


A Mathematical Model And Simulation Of Natural Circulation Loop Thermalhydraulics, Nihad E. Daidzic Mar 1992

A Mathematical Model And Simulation Of Natural Circulation Loop Thermalhydraulics, Nihad E. Daidzic

Aviation Department Publications

In this work, a simple, nonlinear, seventh-order mathematical model with lumped parameter analysis of the thermalhydraulic processes in a natural circulation steam boiler loop is presented. Digital simulation has been performed in order to predict open loop transients in severe accidental situations. Parts of the circulation loop such as the steam drum, downcomer, and riser were modelled separately on the basis of the integral balance equations. The two-phase flow in the steam drum and in the riser was modelled with the aid of a homogeneous-equilibrium, two-phase flow model. Special care was taken to ensure the stability of the numerical scheme, …


Thermal Characterization Of Carbon Monoxide Oxidation Catalysts Using Thermogravimetric Analysts And Differential Scanning Calorimetry, Rene A. Bartgis Oct 1991

Thermal Characterization Of Carbon Monoxide Oxidation Catalysts Using Thermogravimetric Analysts And Differential Scanning Calorimetry, Rene A. Bartgis

Chemistry & Biochemistry Theses & Dissertations

Catalysts composed of platinum and/or palladium on tin (IV) oxide supports, with and without silica gel, as well as catalysts composed of gold on manganese oxide, have been developed for the recombination of carbon monoxide and oxygen to form carbon dioxide for use in carbon dioxide lasers. A thermogravimetric method and a differential scanning calorimetric method have been developed for the thermal characterization of these catalysts. The mass loss data and the enthalpy changes determined as the catalysts lost water were then related to existing activity data for these catalysts. No relationship was found between the thermal data and the …


An Experimental Investigation Of The Finite Time Efficiency Of A Peltier Refrigeration Device, Thomas Schneider Aug 1991

An Experimental Investigation Of The Finite Time Efficiency Of A Peltier Refrigeration Device, Thomas Schneider

Dissertations and Theses

Since the need of energy conservation has become more and more urgent in the past decades, there has been an increased interest in the study and development of more efficient energy conversion systems. One of the fields that have arisen from that endeavor is a branch of physics called Finite Time Thermodynamics (FIT). It may be said that FIT was initiated through the famous paper by Curzon and Ahlborn (1975) that established new bounds on the efficiency of a finite time Carnot heat engine. Before, the traditional treatments gave a fundamental upper limit on the efficiency of any heat engine. …


Evaluation Of Equilibrium Turbulence For A Hypersonic Boundary Layer At Nonadiabatic Wall Conditions, Cindy W. Albertson Jul 1989

Evaluation Of Equilibrium Turbulence For A Hypersonic Boundary Layer At Nonadiabatic Wall Conditions, Cindy W. Albertson

Mechanical & Aerospace Engineering Theses & Dissertations

This paper presents an experimental study to characterize the compressible turbulent boundary layer produced along a flat plate in the NASA Langley 8-Foot High Temperature Tunnel and determine the test conditions necessary to achieve equilibrium turbulence. In addition, the present study extends the data base for equilibrium compressible turbulent boundary layers over quasi-isothermal walls which are far from the adiabatic wall temperature. The measurements consist of pilot pressure, static pressure, and total temperature distributions in the boundary layer. A flat plate measuring 9.7 feet long and 4.3, feet wide was used for the study to provide a naturally turbulent boundary …


The Use Of Thermal Analysis In The Identification And Characterization Of Fibers Of Forensic Interest, Ronald J. Coffey May 1980

The Use Of Thermal Analysis In The Identification And Characterization Of Fibers Of Forensic Interest, Ronald J. Coffey

All-Inclusive List of Electronic Theses and Dissertations

This study investigates the use of thermal analysis for the identification and characterization of fibers for forensic purposes. Fibers such as polyesters, polyacrylics, polypropylenes and nylon were investigated by Differential Thermal Analysis (D.T.A.) and Thermogravimetric Analysis (T.G.A.) to see if their resulting thermograms were characteristic of each fiber. Also, infrared analysis was performed on each fiber. In addition, such factors as heating rate and sample size along with fiber blends were studied as to their effect on thermograms. As a result of this study several important conclusions may be drawn. Although it was found that for the most part D.T.A. …


An Investigation Of A Gas Measurement Technique Employing Ultraviolet Excitation, Alphonso Vincent Diaz May 1970

An Investigation Of A Gas Measurement Technique Employing Ultraviolet Excitation, Alphonso Vincent Diaz

Physics Theses & Dissertations

A study was undertaken to determine the general applicability of a temperature measurement technique which uses the fluorescence stimulated by a vacuum ultraviolet continuum as the indicator. This study was directed toward determining the temperature of nonradiating carbon monoxide. A number of ultraviolet radiation sources which produced high intensity in the region of l,150 A were investigated. This study led to the conclusion that the technique was not applicable to measurements in carbon monoxide within the present limits of' detectability.