Chemical Engineering Commons^™

Characterization Of The Si/Sio2 Interface Formed By Remote Plasma Enhanced Chemical Vapor Deposition From Sih4/N2O With Or Without Chlorine Addition, Young-Bae Park, Xiaodong Li, Shi-Woo Rhee

Faculty Publications

The Si/SiO₂interface formed by remote plasma enhanced chemical vapor deposition (RPECVD) at low temperature with SiH₄/N₂O or SiH₄/N₂O/Cl₂ was studied and compared with thermal oxidation. The interface of the CVD SiO₂ without chlorine addition is rougher than that with chlorine addition. But the surface roughness of CVD SiO₂ films increases with chlorine addition. The thermal oxidation induces strong interface strains, and the strains generated by the CVD SiO₂ without chlorine addition are stronger and are distributed more nonuniformly than those by the chlorinated SiO₂. …

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.

Heat Transfer In Rarefied Gas At A Gas-Solid Interface, Yaşar Demirel, Satish C. Saxena

Papers in Physical Chemistry

Modified expressions for the heat-transfer fluxes at the interface of a solid surface and a gas are given for different Knudsen-number regimes. These expressions for diatomic gases contain both a gas-reflection and a thermal accommodation coefficient. Parallel-plate, coaxial-cylindrical and concentric spherical surfaces are considered. A general expression for the thermal accommodation coefficient is based on experimental data. Sample numerical calculations of heat flux in different heat-transfer regimes are presented in terms of the reciprocal Knudsen number.

Structural Characterization Of Aluminum Films Deposited On Sputtered-Titanium Nitride/ Silicon Substrate By Metalorganic Chemical Vapor Deposition From Dimethylethylamine Alane, Xiaodong Li, Byoung-Youp Kim, Shi-Woo Rhee

Faculty Publications

Alfilmsdeposited on sputtered‐TiN/Si substrate by metalorganic chemical vapor deposition(MOCVD) from dimethylethylamine alane (DMEAA) were characterized using x‐ray diffraction(XRD),Auger electron spectroscopy(AES),atomic force microscopy(AFM), and transmission electron microscopy (TEM). The TiN filmsputtered on the Si has a preferred orientation along the growth direction with the 〈111〉 of the film parallel to the Si〈111〉. Sputtering of the TiN film on the Si induced strains at the interface. The TiN/Si interface is flat while the Al/TiN interface is rough. There exist many dislocations at the Al/TiN interface. The Al₂O₃ phase was formed at the Al/TiN interface during the early stages of …

Studies Of Mixing Processes In Gases And Effects On Combustion And Stability, Frank Paul Kozusko Jr.

Mathematics & Statistics Theses & Dissertations

Three physical models of laminar mixing of initially separated gases are studied. Two models study the effects of the mixing dynamics on the chemical reactions between the gases. The third model studies the structure and stability of a laminar mixing layer in a binary gas. The three models are:

1. Two ideal and incompressible gases representing fuel and oxidizer are initially at rest and separated across an infinite linear interface in a two dimensional system. Combustion, expected as the gases mix, will lead to a rapid rise in temperature in a localized area, i.e. ignition. The mixing of the gases …

A New Spray Evaporation Model Based On Droplet Interface Phenomena, Nihad E. Daidzic, Gangolf Kohnen, Martin Sommerfeld

Aviation Department Publications

In this work the influence of droplet shape oscillations on droplet evaporation is shown. Through nonlinear mode interactions, turbulence and aerodynamic triggering of vibrations cause by vortex shedding, droplets always oscillates in spray flows. Droplet shape oscillation cause higher evaporation rates through several physical phenomena such as an average increase of the superficial surface area, periodic micro-convection and boundary layer destruction, and local saturation pressure changes due to local curvature effects. The inviscid theory of small-amplitude droplet oscillations was used which resulted in better agreement with the measurement data of droplet size distributions in sprays for different axial coordinates.

Excess Heat Capacity Surfaces For Water-Alkanol Mixtures By The Uniquac Model, Yaşar Demirel, Halime Ö. Paksoy

Papers in Physical Chemistry

Hydroorganic mixtures are industrial solvents that can serve as media to solubilize either water in hydrocarbon or a hydrophobic substance in water. In many cases the solubilizing capability is obtained via a homogeneous complex aqueous mixtures containing an alcohol. Since excess heat capacity C_P^E, is very sensitive to structural changes in mixtures, concentration and temperature dependence of C_P^E have been calculated by using the UNIQUAC model for the mixtures methanol(l)-water(%, ethanol(l)-water(2), and l-propanol(l)-water(2). The temperature-dependent parameters of the model estimated directly from C_P^E data at more than one different isotherm are used in …

A Study Of The Thermodynamic And Heat Transfer Characteristics Of Two-Phase Two-Component Flow With Application To A Solar-Assisted Heat Pump, Walid A. Aziz

Mechanical & Aerospace Engineering Theses & Dissertations

Two-phase flow of single component refrigerants has been studied, theoretically and experimentally, for many CFCs, in many industrial applications, including the solar-assisted heat pump system. This study extends the thermodynamic and heat transfer analysis in the phase transition boiling region, to newly proposed refrigerant mixtures, which are candidates for replacing the classical CFCs for future HVAC applications. The goal of this study is to develop a methodology, to design the collector/evaporator tubes of a solar-assisted heat pump, using a binary refrigerant mixture as the working fluid. The method is implemented numerically as a computer algorithm. In order to do that, …

Studies On Nonequilibrium Phenomena In Supersonic Chemically Reacting Flows, Rajnish Chandrasekhar

Mechanical & Aerospace Engineering Theses & Dissertations

This study deals with a systematic investigation of nonequilibrium processes in supersonic combustion. The two-dimensional, elliptic Navier-Stokes equations are used to investigate supersonic flows with nonequilibrium chemistry and thermodynamics, coupled with radiation, for hydrogen-air systems. The explicit, unsplit MacCormack finite-difference scheme is used to advance the governing equations in time, until convergence is achieved.

For a basic understanding of the flow physics, premixed flows undergoing finite rate chemical reactions are investigated. Results obtained for specific conditions indicate that the radiative interactions vary substantially, depending on reactions involving HO$\sb2$ and NO species, and that this can have a noticeable influence on …

Effects Of Radiative Interactions In Molecular Gases Under Local And Nonlocal Thermodynamic Equilibrium Conditions, Manoj Kumar Jha

Mechanical & Aerospace Engineering Theses & Dissertations

Basic formulations, analyses, and numerical procedures are presented to investigate radiative heat interactions in diatomic and polyatomic gases under local and nonlocal thermodynamic equilibrium conditions. Essential governing equations are presented for both gray and nongray gases. Information is provided on absorption models, relaxation times, and transfer equations. Radiative flux equations are developed which are applicable under local and nonlocal thermodynamic equilibrium conditions.

The problem is solved for fully developed laminar incompressible flows between two parallel plates under the boundary condition of a uniform surface heat flux. For specific applications, three diatomic and three polyatomic gases are considered. The results are …

Analysis Of Heat Pump Cycles Using Thermodynamic Equations Of State, Stephen C. Ericson

Mechanical & Aerospace Engineering Theses & Dissertations

In this study, thermal performance of heat pump cycles is analyzed by employing several equations of state. The analysis presented here is particularly useful for applications where refrigerant properties need to be calculated from a thermodynamic equation of state. Such a situation, for example, would arise during a long-term numerical simulation of a solar-assisted heat pump system. In these cases, the direct use of thermodynamic property tables of refrigerants would not be possible in a computational procedure. The approach of using equations of state to predict thermodynamic properties is also useful for applications where new refrigerants or blends of refrigerants …

Transient Simulation Of A Trombe Wall Passive Heating System Coupled To A Thermally Stratified Room, Ali Saleh Kheireddine

Mechanical & Aerospace Engineering Theses & Dissertations

Thermal performance of a Trombe-wall space heating system has been studied numerically for one-day and multiple-day periods. This study analyzes the system performance by simultaneously considering the coupled nature of the channel convection, wall heat conduction and transient room energy balance. A computer program has been written and implemented to assess the effects of system parameters, weather conditions and peak temperature control strategies on the system performance.

The system performance is influenced by such system parameters as the storage wall thickness, channel width and the temperature stratification in the room. Increasing the wall thickness decreases the temperature swings considerably, but …

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, …

Methods Of Measuring The Solubility And Viscosity Of Lubricating Oil/Refrigerant Mixtures At High Discharge Pressures And Temperatures, Nolan Van Gaalen

Faculty Work Comprehensive List

The design and construction of a test facility and methodology for measuring the solubility and viscosity of lubricating oil/refrigerant mixtures at high pressures and temperatures are described. An auxiliary charging system, developed to provide precisely measured quantities of oil and refrigerant to the test facility, is also presented. The test facility was developed under the sponsorship and supervision of ASHRAE which funded this research project (RP-580);The solubility, viscosity and density of mixtures of R-22 and of R-502 with commonly used 150 SUS lubricants have been measured by using this facility. Specifically, results for liquid mixtures of 10% to 40% refrigerant …

Effect Of Viscoplastic Flow Rules On The Initiation And Growth Of Shear Bands At High Strain Rates, R. C. Batra, Chang-Soo Kim

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Marchand and Duffy have reported detailed measurements of the temperature and strain as a shear band develops in a HY-100 steel. Assuming their torsional tests in thin-wall tubes can be adequately modeled by a viscoplastic block undergoing overall adiabatic simple shearing deformations, we investigate the effect of modeling the viscoplastic response of the material by a.power law, and flow rules proposed by Litonski, Bodner and Partom, and Johnson and Cook. Each of these flow rules is first calibrated by using the test data at a nominal strain-rate of 3300 s-1. Then predictions from the use of these flow rules at …

Application Of Mechanical Vapour Recompression To Industrial Slides Drying, Allan Issangya

Tanzania Journal of Engineering and Technology (TJET)

A positive result of the oil crisis of the seventies is the realisation of energy’s value and the need to use it sparingly. Increasing attention has been focussed on all aspects of industry where fuel oil and gas had played a major role.

Industrial drying, one of the most widely applied unit operations in chemical and process engineering, is a highly energy intensive operation. Studies have identified a number of alternatives for lowering energy consumption in this process through various heat recovery techniques.

Due to the difference in their operating principles steam-heated dryers and air-heated dryers, in most aspects, require …

Development Of A Parametric Analysis Microcomputer Model For Evaluating The Thermodynamic Performance Of A Reciprocating Brayton Cycle Engine, Thomas Joseph White

Dissertations and Theses

In this thesis, applicable data from research on IC engines have been adapted to PACE engine designs. Data from studies on heat transfer, friction, and pressure losses, in particular, have been used. Certain parameters which define operation and design characteristics appear to influence PACE engine performance very strongly. Some of the more critical parameters, notably friction and heat transfer coefficients, must be determined experimentally if accurate model results are to be expected. Pressure ratio, compressor RPM, and maximum combustor temperature, the independent operating parameters, also have a dramatic effect on engine performance. Other design or operating characteristics and working fluid …

Simplifying Lubricants For Farm Machinery, R A. Platt

Journal of the Department of Agriculture, Western Australia, Series 4

All moving parts on machinery needs lubrication. With the rapid development in farm machinery and its attendant sophistifications, the stresses imposed on the lubricants have also increased.

This article looks at some of the changes in requirements and developments in lubricants available.

University Of Missouri--Rolla Wood Energy Research, Yildirim Omurtag, V. J. Flanigan, Nathan E. Welch

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

The overall objective of this project is to conduct a research and development program which will lead to the early commercialization of wood gasification technology to process wood residues typical of those found in the Ozark region.

4th Annual Umr-Dnr Conference On Energy -- Entire Proceedings, University Of Missouri--Rolla

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

No abstract provided.

Comparative Residential Energy Consumption And Fuel Costs With Various Types Of Systems: Oil-, Gas-, Electric-Furnaces And Heat Pumps, Ronald Hunter Howell, Harry J. Sauer Jr.

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

The electric air-to-air heat pump for residential heating offers an economic alternative to systems traditionally used extensively for home heating, such as, oil or gas fired furnaces and electric resistance heat. This simulation analysis showed that using 1976 mid- Missouri fuel costs, an oil fired furnace was the least expensive to operate of the three traditional type residential heating units. LP gas heating was 19% higher than oil heat while electric resistance heating was 26% higher in cost than oil. The typical air-to- air heat pumps showed a 29% reduction in the heating bill when compared to an oil furnace.

3rd Annual Umr-Mec Conference On Energy -- Entire Proceedings, University Of Missouri--Rolla

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

No abstract provided.

The Process Refrigeration System At Breweries, H. M. L. Kagaruki

Tanzania Journal of Engineering and Technology (TJET)

Abstract

The Energy Conservation Implications Of Master Metering Of Electric Service In Apartments, Gordon Gross

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

A study has been made of the difference in electricity usage between residents of "Electricity included" apartments and those tenants who pay individual "light bills." The factors which influence owners' and builders' choices of metering service are discussed in detail.

Data taken from over 100 apartment buildings or complexes in 10 major U.S. metropolitan areas and from over 50 major electric power companies are used as the basis for the reported results. Contractors estimates of the costs to convert building service from master to individual meter and some bases for these costs are presented.

The energy conservation potential which might …

A Vehicle For Improving Energy Management For Business And Industry, Herbert M. Eckerlin, Albert S. Boyers

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

A new technical assistance program focusing on the area of energy management has been developed by North Carolina State University for business and industry. This paper describes the operation of the program and presents some typical recommendations made to industry. The impact of the energy crisis on small industry is discussed and future plans for addressing this problem are presented.

Ways To Reduce Peak Electrical Demand In South Louisiana, S. J. Gold, M. D. Bakewell, G. E. Guidry, E. F. Lewis, L. J. Naquin, B. P. Whitney

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

This study analyses alternatives for coping with the peak electrical demand of hot summer afternoons. Economic and Political aspects, as well as technical feasibility, are included. It is concluded that South Louisiana may indeed be able to trim peak demand to 5% below what is anticipated by 1980 , thus making one of the coal fired stations scheduled then unnecessary. However, the contingencies (Natural Gas Shortage, Another Oil Embargo) would make a coal-fired station very desirable.

The Impact Of Direct Coupling Of Solar Cell Arrays To Electric Power Networks, Adel H. Eltimsahy, Fernando L. Alvarado, Thomas W. Boyd

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

This paper has to do with a preliminary investigation of the economic impact of solar cells when directly coupled to a conventional three-phase power network in the Toledo area.

A correlation is established between power system demand curves and solar insolation data in the Toledo area using computer simulation. The correlation studies determine how successfully solar cell/inverter systems can alleviate the power system demand during peak hours. They also show how much solar cell area will be needed to cause a significant impact on the power generating system.

Using computer simulation the initial cost of the solar cell/inverter is compared …

Choosing Alternative Energy Systems Under Conditions Of Uncertainty, Dennis Costello

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

A methodology for simulating the decision process of an investor deciding between alternative energy systems is presented. The approach assumes the investor bases his decision on cost (or rate of return) and risk. Risk is treated directly in the model and not reduced to a certainty equivalent. The rate of return-risk characteristics of many system combinations allows them to be eliminated as viable choices to the investor without reference to his personal attitude toward risk.

Energy Conservation At Monsanto, Ray E. Doerr

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

We at Monsanto want to thank you for the opportunity to tell you about our energy conservation program. We are proud of our accomplishments to date, and are very optimistic regarding plans for the future in energy conservation.

Through our five operating companies and supported by corporate departments, Monsanto directs the conservation efforts at 50 locations in the United States.

We also have a very active conservation program in Canada and Europe.

Storage Of Spent Fuel From Light Water Reactors, W. C. Wolkenhauer

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

The effects of possible inadequate nuclear fuel reprocessing capability upon a public utility, Washington Public Power Supply System, are studied. The possible alternatives for storing spent fuel are reviewed.