Engineering Commons^™

Effect Of The Variations Of The Mobile Dislocation Density On The Thermally Activated Cyclic Deformation Behavior, J. S. Mshana

Tanzania Journal of Engineering and Technology (TJET)

The application of the transition state theory of rate processes to describe tension-tension, strain controlled cyclic deformation BEHAVIOUR was extended to describe the effect of the variations of the mobile dislocation density on the cyclic deformation BEHAVIOUR. It was shown from the derived constitutive relation that due to the net increase in the mobile dislocation density during strain controlled cyclic deformation the stress change per cycle (or in function of time) increases.

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 Spray Drought Cooling Tower, O. K. Kaunde

Tanzania Journal of Engineering and Technology (TJET)

ABSTRACT A noval type direct contact cooling tower has been proposed in which the gas or air entering the tower is drawn by the ejector action of the sprays through which the feed water is admitted. The advantage offered by this type of tower is that it eliminates the usages of fan, thus saving the capital cost and power to drive it.

Entrainment of air by water was studied in a laboratory cooling tower and the result of the entire experiment indicate that the development of a spray drought tower is a feasible practice.

Hydrogen For Power Applications. Task 2: Storage Of Hydrogen In Solid, Liquid And Gaseous Forms. June 1988. 1 V., Florida Solar Energy Center, David L. Block

FSEC Energy Research Center®

This report provides a comprehensive account of the major developments and the issues of concern in the storage and handling of hydrogen in all three forms, namely, solid (as metal hydrides), liquid and gaseous. Keeping in mind that ground transportation has the potential to be the most obvious and widespread utilization vector for hydrogen, particular effort is made to compare alternative storage and handling systems of hydrogen with that of gasoline. Conclusions and recommendations are based on a systematic and unbiased analysis of the pros and cons of various storage and handling options for hydrogen, both demonstrated and projected.

Energy-Efficient Florida Home Building Manual (Revised 1992), Florida Solar Energy Center, Robin Vieira

FSEC Energy Research Center®

This manual presents practical, real-life recommendations on how to design and build homes in Florida. It contains information specific to our state's climate and lifestyles, rather than the overly general information found in most residential building publications. The book was developed in 1992 as an all-inclusive guide for anyone interested in constructing homes that are efficient. It is packed with information that will help you plan such homes, choose the best materials and products for the homes, and if you are a builder or developer - sell and profit from them. The files are all in PDF format. The file …

Theoretical & Computational Investigation Of Algorithms For Simultaneous Heat & Moisture Transport In Buildings. Task 2 Final Report, Milestone #218 & 220 Combined. Iv (Copies 1ref, 2,3), Florida Solar Energy Center, Alp Kerestecioglu

FSEC Energy Research Center®

In keeping with the national energy policy goal of fostering an adequate supply of energy at a reasonable cost, the United States Department of Energy (DOE) supports a variety of programs to promote a balanced and mixed energy resource system. The mission of the DOE Solar Buildings Research and Development Program is to support this goal, by providing for the development of solar technology alternatives for the buildings sector. It is the goal of the Program to establish a proven technology base to allow industry to develop solar products and designs for buildings that are economically competitive and can contribute …

Whole-Building Moisture Experiments And Data Analysis. Draft Task 1 Final Report, Milestone #219. February 5, 1988. 91 P., Florida Solar Energy Center, Adel A. Kamel

FSEC Energy Research Center®

For four months (August -November) in 1987 whole -building moisture capacitance experiments were done on a townhouse in Cocoa, Florida. The experiments were designed to: 1. Observe the response of a building to imposed moisture flux 2. Determine the moisture storage capacity of the building and furnishings 3. Evaluate simple models designed to predict the response of room air humidity ration to pulses of moisture 4. Assess two innovative approaches to cooling (off-peak cooling and DESRAD) The results of the tests indicated that moisture storage in the furnishings is much greater than moisture storage in the air. The bare building …

Comparison Of Various Techniques For The Detection Of Lines In 2-Dimensional Images, Somayajulu Bhamidipati

Theses

The detection of straight lines in 2-dimensional images leading to polygonal approximation to the boundaries of the objects is one of the important stages in scene analysis as it leads to the description of the images. The comparison of three diverse approaches for this problem in terms of the efficiency and accuracy is made, and their performance for different types of data and different sets of parameters is studied in this thesis.

The data points are generated using either an edge detection algorithm using chain encoding on real images or a synthetic data generator, which can create a variety of …

An Analysis Of The Dense Packing Of Disks : A Computer Simulated Approach, Jir-Yih Tsaur

Theses

This thesis is concerned with the analysis of dense packing of hard disks. The Voronoi diagram and the geometric neighbours were first computed. The average number of geometric neighbours of a disk is six. It is thus more efficient to choose structural neighbours from among the geometric neighbours than from among all other disks.

Through the Monte Carlo simulation by Rosato et. al., disk configurations after pouring and subsequent shaking were provided for analysis. The mean number of geometric neighbours and the average coordination number were computed. The angular distribution of the structural neighbours was discussed. The packing fraction increases …

Investigation Of Forces In The Course Of The Water Jet--Work Piece Interaction, Hung-Yuan Li

Theses

This study is concerned with the dynamic of the interaction between the water jet and the work-piece. The piezoelectric transducer was used to construct an experimental setup. The simultaneous use of the constructed setup and strain gage enables us to validate the experimental procedure. The forces in the impingment zone were measured at different operational conditions. Totally about 400 different combinations of these conditions were tested. It was found that the force is mainly determined by the diameter of the sapphire. The effects of the abrasive size , abrasive flow rate, the diameter of the carbide tube, and the stand-off …

Two Domain Heat Transfer Studies Using A Coupled Finite-Difference And Boundary Element Programs, Serap Dikmenli

Theses

An iterative coupling of a finite-difference boundary layer code "STAN5"' and a boundary element code "BEASY"2 have been used to study two dimensional convective-conductive problems. The coupling method essentially leaves undisturbed the codes of these programs and uses their custom features in their applicable domains. The boundary layer program is used-in the convective domain, while "BEASY" is used in the solid domain. Compatability conditions are established between these domain solutions and an iterative scheme is used until these conditions are mutually satisfied.

The indirect communication of compatability (boundary) criteria between these programs was achieved by two editor/data-transferor like programs. Combined …

Role Of Contact Stresses In Surface Fatigue And Wear, Chih-Chi Huang

Theses

This thesis is devoted to the role and analysis of stress distribution at the area of load and slide contact in the surface fatigue. The orthogonal shear stresses are critical stresses for surface fatigue in pure rolling contact. On sliding combination with rolling, the maximum shear stresses become to be the prime cause for surface fatigue because they move from subsurface toward the surface. The compressive residual stress induced during manufacturing could increase the resistance to surface fatigue. Sliding speed rarely affects the stress distribution and surface fatigue. From investigation of the stick-slip region in the contact area, sliding wear …

Investigation Of A Technology For Glass Shaping By The Use Of Abrasive Waterjet, Wu-Tzung Lee

Theses

This study investigates the effects of AWJ properties on the results of glass machining and examines the feasibility of contour glass cutting. The principal defects of AWJ glass cutting are identified. A practical technique to prevent defects and to improve the quality of the glass surface is presented. A computer package was developed to provide a computer-aided programming function, a control program transformation fuction, and a object image operation function. Throughout the programming function, robot control programs can be generated to improve cutting quality and cutting speed. The transformation function can be used to change the programming modes or the …

Computer Aided Synthesis Of A Four-Bar Linkage To Generate A Symmetrical Coupler Curve, Shailendra R. Pachalag

Theses

The purpose of this study is to develop a new analytical technique for the synthesis of four-bar mechanisms to generate symmetrical curves with a coupler point passing through 8 points. The geometric expressions involved in kinematic synthesis often tend to offer difficulties such as negative radicals, alternative choices and repetitions. Here a solution procedure has been developed which avoids these difficulties. This solution procedure includes a development of a computer algorithm that should synthesize a crank-rocker type linkage for any given input crank length. This algorithm dismisses all solutions involving negative radicals and lists magnitudes of members so that those …

Design And Construction Of A Thermoelectric Calorimeter To Measure Thermal Resistance Of Building Components, Ravindra Samtaney

Theses

The steady-state thermal resistance of a building wall is an important parameter in determining its thermal performance. In-situ measurement of thermal resistance is the only unambiguous way of determining thermal resistance since the actual value may significantly differ from the laboratory or the calculated R-value.

Hitherto, the in-situ measurement of thermal resistance has been largely confined to the winter season. A thermoelectric calorimeter was designed, constructed and tested in order to provide measurements of thermal resistance during the summer as well as the winter season.

This thermoelectric calorimeter is a rectangular box, insulated on five sides and covered with an …

Integration Of Cad/Cam System Into A Waterjet Cutting Cell, Sanjay C. Shah

Theses

The work is intended to bridge the gap between CAD and CAM fora waterjet cutting cell. The output of CAD is used by CAM directly through the software interface developed. To achieve this, a postprocessor is designed for a two-dimensional system for the series 8200 Allen Bradley's 5-axes Robot Controller. Calma's DDM & DIMENSION III interactive graphics system implemented on VAX was used for the part design. The postprocessor is a computer program, written in the structured FORTRAN, that is unique for a given machine-tool/controller combination. The conversion of the coding and recording format of the APT file to the …

Seizure And Wear Testing Methodology, I-Tsung Shih

Theses

In this work the seizure as an adhesive wear has been discussed and analyzed The diffusion hypotheses is accepted as the seizure mechanism. It was determined that the surface of machine components, material properties, and contact stresses in sliding and loading zone are responsible for the wear.

A computer controlled wear testing methodology has been developed and a wear testing machine has been designed and assembled. The tests for the selected gray cast non and alloy steel specimens with different surface treatment were performed on the designed wear testing machine.

The test results showed that the selected materials with additional …

Investigation Of High Shear-Rate Viscoelastic Flow, Sudarshan S. Sood

Theses

The object of this study is to understand two important characteristics exhibited by viscoelastic fluids at high shear-rates, and analyse their influence on practical applications Viscoelastic fluids, such as polymer solutions, when subjected to high shear stress, behave in a manner which has not been sufficiently analytically explained In experimental studies, such fluids have shown.

(a) Stress relaxation.

(b) Decrease of viscosity with an increase in shear rate.

(c) Slight decrease of viscosity with temperature.

(d) Normal stress differences in shear flow.

In this thesis an analytical explanation is given for two (a and b ) of these features This …

Automatic Generation Of Robot Paths For Waterjet Cutting From Autocad Drawings, Samir Vij

Theses

The automatic generation of robot paths for a commercial water-jet cutting system by establishing a link with a commercial CAD system, in an attempt to achieve paper-less manufacturing and to minimize human interface is the objective of this thesis.

Water-jet cutting is an emerging technology with unlimited potential for a wide variety of manufacturing applications. Water-jet cutting systems integrated with robotic work cells allow the user to cut a variety of parts through part programs generated for robot controllers. The system employed is an Ingersoll-Rand water-jet cutting system, the movement of which is controlled by an Allen-Bradley 8200R programmable robot …

Investigation Of The Characteristics Of The Kerf And The Surface Generated In The Course Of Cutting Titanium With Abrasive Waterjets, Ajay Vora

Theses

The effect of cutting parameters on the quality of cut in the course of cutting Titanium (Gr.2) with Abrasive Waterjet is investigated. The cutting parameters include nozzle traverse rate, size and feed rate of abrasives and nozzle(s) diameter. The width of kerf (top and bottom ), taper and roughness is studied. The measurements are tabulated and plots are made to study the trend and relationship for each set of parameters.

The qualitative conclusions are made successfully but no quantitative relationship was derived. Suggestions are made for the evaluation of technology for feasibility and economic justification, and to achieve desired cutting …

Comparative Energy Analysis Of An Office Building Using A Microcomputeromparative Energy Analysis Of An Office Building Using A Microcomputer, Dale Krasnoff Bromberg

Theses

An energy analysis was performed on an office building using two different software packages - ASEAM and Trakload. The structure studied was the P.S.E. & G. headquarters in Newark, N.J.. The results of various parametric runs were compared. Then results from one of the programs were compared with results of a study carried out by Tishman Research Corporation and Jaros, Baum & Bolles, consulting engineers.

Although the two software products had variations in input requirements, overall the results of the two programs were similar. The overall deviation for total energy consumption between the two programs was between 3% and 15%. …

Rbs Technology: Task 3 Report, Florida Solar Energy Center, Philip W. Fairey

FSEC Energy Research Center®

The purpose of this report is to discuss the current state of attic radiant barrier system (RBS) technology. Concepts, research issues and experimental test results are presented and discussed.

Test 1607: White 160 Diesel And White Workhorse 170 Diesel 18-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1608: Field Boss 185 Diesel, White 185 Diesel And White Workhorse 195 Diesel 18-Speeds, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

A Feasible Direction Procedure For General Multiple Objective Optimization, Wen-Tsia Liu

Dissertations

The Feasible Direction Finding Problem (DFP) of Zoutendijk is adapted to create a general Mathematical Programming (MP) algorithm for treating optimization problems with multiple objective functions. Classically such problems are reduced to standard MP form by converting them to single objective function problems by the use of weighting functions. Unfortunately not all practical problems can be so reduced. Consider the problem of maximizing the strength of a structure. Typically there are several, or even many, failure modes. All active failure modes must be included in the optimal search in such a way that resistance to one active mode can not …

Integral Equation Solution Of The Full Potential Equation For Three-Dimensional, Steady, Transonic Wing Flows, Li-Chuan Chu

Mechanical & Aerospace Engineering Theses & Dissertations

An integral equation method for solving the full potential equation has been developed for three dimensional transonic vortex-wing flows. This method is capable of capturing shocks using the Murman-Cole type of finite difference scheme and is capable of predicting accurate and force-free wake shape as well.

Reading the full potential equation as Poisson's equation, the solution for the velocity field has been expressed in terms of an integral equation using Green's theorem. The solution consists of a surface integral of vorticity distribution on the wing and its free-vortex sheets and a volume integral of source distribution within a computational region …

The Effect Of Elastic Boundary Conditions On The Dynamic Response Of Rectangular Plates, Terry K. Brewer

Mechanical & Aerospace Engineering Theses & Dissertations

Natural frequencies and forced steady-state harmonic response for the vibration of uniform rectangular plates with edges elastically restrained against rotation and transverse translation are addressed. A single mode Rayleigh-Ritz solution is derived using functions that describe the normal modes of vibration of a beam whose ends are elastically restrained. The finite element solution is obtained for comparison. MACSYMA symbolic manipulation system is implemented as an aid to the mathematical rigor of the Ritz approach and NASTRAN finite element code is used to model the mechanical system. Comparisons are made to published results and the solutions of this study are found …

Investigation Of Supersonic Chemically Reacting And Radiating Channel Flow, Mortaza Mani

Mechanical & Aerospace Engineering Theses & Dissertations

The two-dimensional time dependent Navier-Stokes equations are used to investigate supersonic flows undergoing finite rate chemical reaction and radiation interaction for a hydrogen-air system. The explicit multi-stage finite volume technique of Jameson is used to advance the governing equations in time until convergence is achieved. The chemistry source term in the species equation is treated implicitly to alleviate the stiffness associated with fast reactions. The multi-dimensional radiative transfer equations for a nongray model are provided for a general configuration, and then reduced for a planer geometry. Both pseudo-gray and nongray models are used to represent the absorption-emission characteristics of the …

A Comment On ‘Failure Modes Of Hybrid Composites …’, Serge Abrate

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper comments on an earlier paper on the failure modes of hybrid composites by Pitkethly and Bader, which appeared in the Carbon Fiber Conference issue. © 1988 IOP Publishing Ltd.

Stability Of Steady Cross-Waves: Theory And Experiment, Seth Lichter, Andrew J. Bernoff

All HMC Faculty Publications and Research

A bifurcation analysis is performed in the neighborhood of neutral stability for cross waves as a function of forcing, detuning, and viscous damping. A transition is seen from a subcritical to a supercritical bifurcation at a critical value of the detuning. The predicted hysteretic behavior is observed experimentally. A similarity scaling in the inviscid limit is also predicted. The experimentally observed bifurcation curves agree with this scaling.