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Articles 181291 - 181320 of 197527

Full-Text Articles in Engineering

Arithmetic Pipeline Analysis Package Ii, Sai K. Vedantam May 1989

Arithmetic Pipeline Analysis Package Ii, Sai K. Vedantam

Theses

This work describes the implementation of arithmetic pipeline scheduling algorithms, to enhance an existing simulation package. The user need only specify the arithmetic equations to be processed and the required stage configuration. The program automatically performs the tasks of forming the reservation table, building the pipeline and specifying the input/output connectivity for each segment and multiplexer in the pipeline. This package integrates two existing simulation tools and enhances many aspects of the previous programs.

The main application area for such a tool is education. Since it is very easy to use and requires little or no time for one to …


Image Coding With Quantization Noise Feedback, Jen-Chieh Wang May 1989

Image Coding With Quantization Noise Feedback, Jen-Chieh Wang

Theses

A progressive image transmission based on Laplacian pyramid structure is used for the scheme of quantization noise feedback. Because a reduction in transmission rate inevitably increases the quantization noise and degrades the image quality, the designer of the quantizer laces the dilemma of balancing the transmission rate and the quantization noise. Using the algorithm of noise feedback will reduce the quantization error without appreciably increasing transmission rate. Uniform quantization and nonuniform quantization rate used to compare the result with or without noise feedback. In the transmitter end, the original image can be reduced by a certain procedure to form a …


Recirculation Flow Bioreactor For The Synthesis Of Nitroxide And N-Oxide Pharmaceuticals, Douglas Lischick May 1989

Recirculation Flow Bioreactor For The Synthesis Of Nitroxide And N-Oxide Pharmaceuticals, Douglas Lischick

Theses

An investigation of the properties of calcium alginate immobilized hog liver microsomes, rich in FAD-containing mixed function oxidase, was performed. Studies involving catalyst storage, immobilization of cofactors within the matrix, and alginate gel concentration were performed using a 1.8 ml mixed flow micro assay reactor. A recirculation flow reactor was designed and used for the biochemical production of 2,2,4,4-tetramethyl-1,3-oxazolidine-l-oxyl, a potentially useful MRI contrast agent.

The activity of the immobilized microsomes was found to increase over time when stored in CaCl2 or in buffer at 4-8°C. The increase in activity is a result of the removal of inherent inhibitors …


An Intelligent Electrocardiogram Tutoring Package Ekgchallenger, Santosh K. Ananthraman May 1989

An Intelligent Electrocardiogram Tutoring Package Ekgchallenger, Santosh K. Ananthraman

Theses

This thesis presents the development and implementation of an intelligent electrocardiogram tutoring package, namely, EKGCHALLENGER which is meant for use in medical schools to teach medical students a method of diagnosing electro cardiograms.

EKGCHALLENGER is an IBM - PC based, user friendly package. It works in two basic modes. The first is a tutorial mode wherein the user is taught the step-by-step diagnosis of electrocardiograms ( EKGs ) which are presented in order of increasing difficulty. The second is the challenger mode wherein the user is asked to diagnose EKGs which are randomly chosen from an EKG database. The diagnosis …


Anaerobic Biodegradation Of Trichloroethylene By Activated Carbon Fluidized-Bed, Yeam-How Chin May 1989

Anaerobic Biodegradation Of Trichloroethylene By Activated Carbon Fluidized-Bed, Yeam-How Chin

Theses

Abstract - The biodegradation of Trichloroethylene by using anaerobic activated carbon fluidized bed has been investigated in the present study. High quality effluent was obtainable when the TCE influent concentration was up to 2.4 ppm in the first stage. Glucose was introduced as a cosubstrate to determine the effects of glucose/TCE ratio on the COD, Glucose and TCE removal. The experimental data indicates that the overall TCE removal efficiency was only slightly affected by TCE loading, but the first stage performance was significantly influenced by TCE loadings. It was also found that the microbial activities were affected by TCE loadings …


An Interactive Graphics Capability For Numerical Design Optimization, Abbay P. Joshi May 1989

An Interactive Graphics Capability For Numerical Design Optimization, Abbay P. Joshi

Theses

Hierarchical Object Oriented Program Software [HOOPS] is used here to develop an interactive graphical interface for the design optimization program CADOP5. A preprocessor provides the user with button menu options. Using various buttons like Variable Button, Obj Button, Parameter Button, etc. the user can interactively define problem variables, parameters and limits as well as interactively modify the behavior and the constraint functions. The post processor displays variable values for three consecutive design cycle in the form of bar charts. Objective function values are plotted against the number of design cycle. Using this information the user can determine if the solution …


The Kinetics Of Degradation Of 1,2-Dichloroethane, 1,1,1-Trichloroethane And 1,1,2,2-Tetrachloroethane In A Photoreactor Using Ozone, Hydrogen-Peroxide And Ultraviolet Radiation, Yuan-Shen Li May 1989

The Kinetics Of Degradation Of 1,2-Dichloroethane, 1,1,1-Trichloroethane And 1,1,2,2-Tetrachloroethane In A Photoreactor Using Ozone, Hydrogen-Peroxide And Ultraviolet Radiation, Yuan-Shen Li

Theses

The experiments to oxidize the refractory chemicals, 1,2- Dichloroethane, 1,1,1-Trichlotoethane and 1,1,2,2- Tetrachloroethane using Ozone, Hydrogen Peroxide and Ultraviolet Radiation have been conducted in a ss-304 photoreactor. The reaction kinetic models have been proposed and through the experiments we demonstrate that these models for these compounds perfectly. Analysis is done by gas chromatograph for the substrate concentration and the gas/liquid mass transfer coefficients are calculated. The reaction late constants are determined by use of the Rosenbrock Hillclimb Optimization Algorithm in conjunction with the Fourth-Order Runge- Kutta method on a digital computer. By comparing the effects of O3,O3 …


Distributed Data Collection System Based On Hierarchical Network, Harish Mahindrakar May 1989

Distributed Data Collection System Based On Hierarchical Network, Harish Mahindrakar

Theses

On line data collection systems are essential in order to satisfy the requirements for real-time applications. Typical applications are computer integrated manufacturing, security control, hourly wage calculations, human resources management. On line data collection system makes it possible to closely monitor and track different operations with more accuracy. On line data collection systems eliminate redundant work, save time and money.

If the distributed system is based on a multicontroller, it becomes really cost effective solution to build such a system.

This effort is the design of a distributed multicontroller system, required in a data collection system. A hierarchical network is …


Nonlinear, Metal-Clad Optical Waveguide, Bhavesh Patel May 1989

Nonlinear, Metal-Clad Optical Waveguide, Bhavesh Patel

Theses

Planar optical waveguides consisting of different types of films including nonlinear films with metal cladding have been studied theoretically. Ideal metal cladding with σ = ∞ and nonideal metal cladding with σ ≠ ∞, that is, with complex refractive index is considered to get electric field and wave number for TE0 mode. For nonlinear material, approximate solution is derived in a series form using Rayleigh-Schrodinger method. The appropriate eigenvalue equations are solved by Newton-Raphson iteration method. For self-focusing media in the center, the propagation constant increases with increasing power and with self-focusing media in the cladding the propagation constant …


Environmental Impact Assessment For Water Resources Projects : Planning Procedure And Analytical Methods, Mahadesh C. Tumkur May 1989

Environmental Impact Assessment For Water Resources Projects : Planning Procedure And Analytical Methods, Mahadesh C. Tumkur

Theses

This thesis presents a state of the art review of environmental impact assessment procedures utilised in the water resources projects which have evolved over the past two decades. The methodologies employed and some of their limitations which exist and are inherent in both the planning and assessment phases of analysis are identified. The above was supplemented by an investigation of the various views of professionals currently employing the above methodologies. The review effort summarizes the relevant information obtained from the literature which is rather dynamic because of the ever evolving nature of the field. One conclusion drawn from this study …


A Robot Vision System For Determining 3-D Coordinates Of Object Points, Tea-Quin Kim May 1989

A Robot Vision System For Determining 3-D Coordinates Of Object Points, Tea-Quin Kim

Theses

A stereo disparity algorithm is implemented on an industrial robot vision system. One camera manipulated by an industrial robot is used to obtain stereo images of an object. After a pair of stereo images are processed, the points of interest are selected from each image. The similarities of three types of feature characters are used to assign initial weights of the, matching probabilities to a set of point candidates. Then a relaxation method, which is based on probabilities of local connectivity, similarity of feature characters, and smoothness of matching, is used iteratively to improve the initial probabilities of image matching. …


Competitive Bidding Strategy In The Construction Industry : A Game Theoretic Approach, Hongbin Chen May 1989

Competitive Bidding Strategy In The Construction Industry : A Game Theoretic Approach, Hongbin Chen

Theses

A game theoretic approach is applied to analyze competitive bidding in the construction industry because previous models do not consider the conflict of interest that exists among competitors. The game theoretic model improves corporate performance when compared to previous Bayesian analyses.

The game theoretic model is discussed in conjunction with construction contracting practice. Competitive bidding is formulated as a game theoretic model in which a contractor optimizes his bid price to maximize his utility or corporate performance. Using available historical data, order statistics are employed to access the distribution of estimated costs among bidders for a project. The winner's curse …


Management Of Construction Jobsite Productivity : A Self Assessment Approach, Nicos Poliviou Nicolaou May 1989

Management Of Construction Jobsite Productivity : A Self Assessment Approach, Nicos Poliviou Nicolaou

Theses

A critical component of construction project management is the improvement of jobsite productivity. This paper proposes a procedure for use by project managers to assess jobsite productivity performance. The methodology provides a framework which when applied will identify specific aspects of the jobsite where potential productivity improvement is possible. A major feature is its systematic approach which will direct the project manager to the specific resources which when better managed will lead to lower construction costs.


Mathematical Model Of A Continuous Sterilization System For Fermentation Media Containing Suspended Solids, Mark A. Leskowicz May 1989

Mathematical Model Of A Continuous Sterilization System For Fermentation Media Containing Suspended Solids, Mark A. Leskowicz

Theses

A mathematical model has been developed for a continuous sterilization system where the role of suspended solids on the overall degree of sterilization achieved is taken into account. Evaluation of a "typical" commercial continuous sterilization system showed the role of suspended solids to have little effect on the overall sterilization obtained. For continuous sterilization systems operating in a total residence time of less than one minute, the role of solids may become important and should be evaluated.


A Study Of The Effect Of Some Inhibitors On The Corrosion Rates Of Austenitic Stainless Steels In Sulfuric Acid, Shang-Yinn Chiou May 1989

A Study Of The Effect Of Some Inhibitors On The Corrosion Rates Of Austenitic Stainless Steels In Sulfuric Acid, Shang-Yinn Chiou

Theses

Four sulfur-containing and three nitrogen-containing organic compounds have been tested as inhibitors for four different austenitic stainless steels-SS304, S5316, SS317L, and SS41O-in 10-50 weight% sulfuric acid solutions respectively. Results confirmed that the sulfur-containing compounds were more effective than the nitrogen-containing compounds. The effect of sodium iodide additions on the behaviours of two of the nitrogen-containing compounds was also studied. The synergistic effect caused by the 1 ion was essential for nitrogen-containing compounds as inhibitors in sulfuric acid solution.


Adsorption And Desorption Of Chromium On Clayey Soils, Ker-Shu Tan May 1989

Adsorption And Desorption Of Chromium On Clayey Soils, Ker-Shu Tan

Theses

Chromium residue waste was produced during sixties in the chromium production process. It was used as construction fill. Problems associated with chromium waste sites include structure distress and surface and groundwater contamination.

The purpose of this study was to investigate the adsorption and desorption of chromium on soil. In order to achieve this purpose, experiments were conducted to study the effect of pH, type of chromium compound, and type of soil on adsorption and desorption.

Experiments were performed on kaolinite, bentonite and sand. In our study, it was found that sand had almost no adsorption for chromium. Kaolinite had less …


Statistical Multiplexing Of Video Sources For Packet Switching Networks, Krishna Kancherla May 1989

Statistical Multiplexing Of Video Sources For Packet Switching Networks, Krishna Kancherla

Theses

Communication networks are fast evolving towards truly integrated networks handling all types of traffic. They employ integrated switching technologies for voice. video and data. Statistical or asynchronous time division multiplexing of full motion video sources is an initial step towards packetized video networks. The main goal is to utilize the common communication channel efficiently, without loosing quality at the receiver. This work discusses the concept of using statistical multiplexing for packet video communications. The topology of a single internal packet network to support ISDN services has been adopted. Simulations have been carried out to demonstrate the statistical smoothing effect of …


A Non-Invasive Technique For Burn Area Measurement, Jong-Daw Yu May 1989

A Non-Invasive Technique For Burn Area Measurement, Jong-Daw Yu

Theses

The need for a reliable and accurate method for assessing the surface area of burn wounds currently exists in the branch of medicine involved with burn care and treatment. The percentage of the surface area is of critical importance in evaluating fluid replacement amounts and nutritional support during the 24 hours of postburn therapy. A noninvasive technique has been developed which facilitates the measurement of burn area. The method we shall describe is an inexpensive technique to measure the burn areas accurately.

Our imaging system is based on a technique known as structured light. Most structured light computer imaging systems, …


Rays And Beams Near The Shadow Boundary, Weixing Gao May 1989

Rays And Beams Near The Shadow Boundary, Weixing Gao

Theses

Asymptotic techniques in wave propagation problems exhibit attractive features in computational aspects compared to numerical methods. However, they experience problems in complicated environments due to the transition regions associated with them. The transition region involving a shadow boundary in the downward refractive index profile has been investigated. The ray paths were determined solving the ray equation analytically. The Green's function due to a line source is constructed and evaluated using numerical integration (reference solution) and asymptotic techniques. Then, the field produced by the source, is synthesized, using superposition of beams generated from complex source point representation. The floating parameters such …


Reduced Complexity Receivers For Trellis Coded Modulations Via Punctured Trellis Codes, Bonchul Koo May 1989

Reduced Complexity Receivers For Trellis Coded Modulations Via Punctured Trellis Codes, Bonchul Koo

Theses

We introduce a new concept, called matched punctured trellis encoding, that simplifies the complexity of Maximum Likelihood Sequence Estimation (MLSE) receivers for combined trellis encoding and modulations with memory. Matched punctured trellis encoding is applied to tamed frequency modulation (TFM) which is a bandwidth efficient correlative - FM scheme. TFM finds applications in satellite, microwave radio, and mobile communications.

Our approach is based on puncturing a rate - 1/2 matched convolutional code to obtain a rate - 2/3 mismatched code. A matched code is one that produces trellis coded modulations of minimum complexity. Puncturing these codes to obtain mismatched codes …


Schottky-Barrier Solar Cells, Surface Patterning For Efficient Light Collection, Constantinos Manolis May 1989

Schottky-Barrier Solar Cells, Surface Patterning For Efficient Light Collection, Constantinos Manolis

Theses

Different geometrical surface configurations are considered here for a Au/n-Si semiconductor Schottky-barrier solar cell to improve their light collection efficiency.

Optical and electrical properties are theoretically analyzed for two given optical wavelengths of 0.9 and 0.5 micrometers respectively.

The configurations considered are: V-shaped, Star- shaped, M-shaped, asymmetric-V-shaped, and asymmetric-M-shaped. They all show a significant improvement in the short-circuit current over a flat cell model, while the open-circuit voltage remains practically unchanged.


Design Of A Gear Driven Anti-Twister Mechanism For A Seal-Less Blood Processor, Ajit Nachiket Dastane May 1989

Design Of A Gear Driven Anti-Twister Mechanism For A Seal-Less Blood Processor, Ajit Nachiket Dastane

Theses

This thesis presents the design of a gear driven anti- twister mechanism for a blood cell separator. The anti- twister mechanism allows for continuous feed and discharge lines that are rigidly attached to the rotating centrifuge head, thus eliminating the need of rotating seals. It is anticipated that the device using a gear driven anti-twister mechanism will have smoother power transmission and closer rpm tolerances.

In addition, a procedure for the dynamic analysis of the existing device, which uses a belt-driven anti-twister mechanism, is developed. The experimental values obtained from the device are compared with the theoretical values obtained by …


Computer Controlled Oxygen Bioreactor, Dinesh Sachdeva May 1989

Computer Controlled Oxygen Bioreactor, Dinesh Sachdeva

Theses

A computer controlled oxygen bioreactor has been designed to obtain more accurate values for oxygen bioreactor requirements and to optimize oxygen productivity with respect to oxygen concentration. This study solves a specific problem relating to oxygen concentration measurement and bioreactor control. The proposed reactor system is computer controlled to insure a desired oxygen concentration supply to an oxygen consuming reaction or organism. This thesis also explains and illustrates the bioreactor and its computer control system.

The computer controller incorporates oxygen sensing, oxygen measurement and temperature measurement, Electrical circuits have been designed and built for proper signal conditioning, data acquisition, data …


Estimation Of Thermodynamic Properties Of Petroleum Fractions To Supplement The Aspen Simulator, Steven E. Sund May 1989

Estimation Of Thermodynamic Properties Of Petroleum Fractions To Supplement The Aspen Simulator, Steven E. Sund

Theses

The objective of this study was to develop a method of estimating hydrocarbon pseudocomponent data in a format that is consistent with the ASPEN simulator. Although algorithms exist to estimate the pseudocomponent properties, no comprehensive program exists for the public version of ASPEN. A computer program was developed which will take a minimum of input data and can generate the necessary pure component properties for an ASPEN simulation. The program is meant to complement the ASPEN simulator, so the input is similar to ASPEN's input. The output can be incorporated directly into an ASPEN input or can be of the …


Multiphase Solid-Liquid And Solid-Liquid-Gas Mixing In Stirred Tanks, Jessyca Susanto May 1989

Multiphase Solid-Liquid And Solid-Liquid-Gas Mixing In Stirred Tanks, Jessyca Susanto

Theses

A number of investigations can be found in the literature on the effect of mixing parameters on solid-liquid dispersions in agitated systems. However, the determination of the effect of impeller clearance on minimum suspension speed has received little attention. This work is mainly focused on the determination of the effect of the impeller clearance on Njs (the minimum agitation speed required for complete solid-liquid dispersion) and its corresponding power consumption, using both radial and axial impellers in stirred tanks. In addition, the effect of other significant parameters on Njs was also investigated.

The importance of the impeller clearance …


Design Of Governor-Turbine Models In Stability Studies, Vidyanand Swaminathan May 1989

Design Of Governor-Turbine Models In Stability Studies, Vidyanand Swaminathan

Theses

This thesis investigates the effect of hydro governor-turbine models on the steady state stability of an automatically controlled electric power system. Basically two kinds of hydro governor-turbine models, namely, Impulse and Francis type are studied in depth. Design of a compensating network has also been proposed, which can help improve the stability conditions of a power system which employs a poor governor-turbine model.

The power system investigated includes a large sized hydro generating unit connected to an infinite bus via a power network. This generator employs a modern three-channel fast-acting automatic voltage regulator (AVR). For any operating condition, stability results …


Slurry Wall Backfill Integrity And Desiccation, Mahendraratnam Thilliyar May 1989

Slurry Wall Backfill Integrity And Desiccation, Mahendraratnam Thilliyar

Theses

The upper reaches of slurry wall, in a waste containment structure may under go cycles of wetting and drying, because of seasonal ground water level fluctuations. This may result in desiccation and cracking of back fill material. Experiments were conducted to study these effects with water, aniline, phenol, hydrochloric acid solutions on soils containing different proportions of bentonite, kaolinite, and sand. The largest crack was formed with phenol and the smallest with water. With hydrochloric acid no crack was formed. With increase kaolinite content, the width and density of crack decreased. Hydraulic conductivity tests on cracked specimens indicated high hydraulic …


Thermal Desorption Of Phenol Contaminated Clay Soils, Chia-Ling Ting May 1989

Thermal Desorption Of Phenol Contaminated Clay Soils, Chia-Ling Ting

Theses

Clay mineral/organic reactions have been studied extensively by a numerous physicochemical methods. There also has been extensive research done in the areas of adsorption, Lewis acid-base reactions, desorption, adduct formation. Many of these studies explain the role and dehydration of silicates.

Studies have shown through extraction, thermal analysis, and gas chromatography. That there is more than one type of bonding, weak and strong, taking place between the clay mineral and the organic waste.

In order to determine the practicality of the containment technology, this research has been investigated by using more powerful tools, such as thermogravimetric analysis, differential scanning calorimetry …


Analysis On Dielectric Resonators, Xuan Tu May 1989

Analysis On Dielectric Resonators, Xuan Tu

Theses

This dissertation deals with the studies and analysis of Dielectric Resonators (DR). A shielded dielectric iesonator structure, consisting of the substrate, the spacer, the dielectric resonator and the metallic shielding is modelled theoretically. The theoretical expressions for the resonance fields are derived by using radial-mode matching and axial mode-matching techniques. In these techniques, the structure is divided into partial regions and the fields in each pai tial region are represented in terms of a series of the appropriate modes with unknown coefficients. Matching the adjacent regions yields a system of linear or nonlinear equations — which then are solved. The …


Spectrum Analysis Of Heart Rate Variability, Xuming Wang May 1989

Spectrum Analysis Of Heart Rate Variability, Xuming Wang

Theses

This research investigated the respiratory influence on heart rate variability. The heart rate spectrum was obtained from the heart rate variability signal which was extracted from the electrocardiogram We then studied the magnitude of the respiration peak in the heart rate spectrum and examined the dependence of the magnitude of this peak on breathing frequency, subject and day.

An experiment designed to simultaneously acquire the electrocardiogram and the respiration signal was conducted on ten people ranging from 22 to 55 years of age (3 females, 7 males). Three tests were performed on each subject. In each test, 2 different postures …