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Articles 70921 - 70950 of 77545

Full-Text Articles in Engineering

Performance Of Single Dwell Serial Synchronization System, Chan-Yee Hsiung May 1988

Performance Of Single Dwell Serial Synchronization System, Chan-Yee Hsiung

Theses

By using the sampling theorem, the problem of the detection of a signal in white Gaussian noise, reduces to the consideration of the sum of the squares of statistically independent Gaussian variates. If the transmitter and and receiver are not synchronous, then no data transmission is possible and the decision statistic has a central chi-square distribution. Otherwise, the decision statistic has a non-central chi-square distribution. Also, this. paper presents a method to calculate the mean and variance of the acquisition time which are the most important parameters to evaluate the performance of a PN spread synchronization system. In addition, the …


Development Of 8052ah-Basic Based Single Board Computer Ii, Suping Lou May 1988

Development Of 8052ah-Basic Based Single Board Computer Ii, Suping Lou

Theses

8052AH-BAISC Based Single Board Computer II ( SBC II ) is designed and developed for the application in biomedical instruments as an embedded central processing unit. SBC II offers powerful function in digital signal acquisition, storage and processing, smart on-board EPROM programming, various preipheries supporting and custom supervisor program. The techniques of design and development of SBC II includes computer aided circuits analysis and schematic, optimal design algorithms and computerized setting up SBC II prototype.

This thesis combines the analysis of SBC II circuitry, set up and operation of the complete computer aided electrical circuit design software OrCAD/SDT specifics in …


3-D Reconstruction Of Microvasculature From High Voltage Electron Microscopy (Hvem) Data, Pradip Kumar Paul May 1988

3-D Reconstruction Of Microvasculature From High Voltage Electron Microscopy (Hvem) Data, Pradip Kumar Paul

Theses

This is a new method for histoarchitectural and volumetric analyses of cell compartments of microvasculature with the use of a unique combination of computerized 3-D reconstruction and HVEM thick serial cross sections. The technology is potentially a reliable, simple, accurate and fast method. Pioneering work in this area was started by Todd et al. (Circ Res Vol :53 p 319 ;1983) basically using light microscopy, but supported by conventional ultrathin transmission electron microscopy. These techniques are important in that they promise to resolve controversies in terms of evaluating the occurance of hyperplasia and hypertrophy in small resistance vessels in various …


Biosynthesis Of Amine Oxides Using Calcium-Alginate Immobilized Hog Liver Microsomes : An Evaluation Of Process And Reactor Design, Ioannis I. Valvis May 1988

Biosynthesis Of Amine Oxides Using Calcium-Alginate Immobilized Hog Liver Microsomes : An Evaluation Of Process And Reactor Design, Ioannis I. Valvis

Theses

An evaluation of the biocatalytic ability and the potential utilization of Calcium-alginate immobilized hepatic microsomes (beads) for the biosynthesis of amine oxides has been performed, To accomplish this task, the following three areas Were investigated: immobilization, catalytic biooxidation ability, and reactor configurations.

Immobilization was found to result in higher yields over free microsomes at the expense of higher cofactor requirements. Refrigerated drying of immobilized micro-somes appears to be a better storage technique than wet storage in buffer. Smaller beads resulted in higher rates than larger beads, but size did not affect the overall yield.

Chlorpromazine (CPZ), diphenylamine (DPA) and 4-hydroxy-2,2,6,6-tetramethylpiperidine …


Study Of The Structure And Capacity Of Construction Industry In Pakistan, Tayyab A. Ansari May 1988

Study Of The Structure And Capacity Of Construction Industry In Pakistan, Tayyab A. Ansari

Theses

The construction industry is the second largest sector in Pakistan's economy after agriculture. It is a fragmented industry which includes very small and very large contracting groups. It includes professional groups such as architects, engineers, management personnel etc. Major part of this industry is dominated by material's suppliers, vendors etc.

In the light of the developments which have taken place particularly over the last ten years, the study has covered the capacity of the construction industry in terms of estimated output, availability of manpower, demand and production of building materials , financial problems, credit, quality of work, the role of …


Implementing Ray Tracing Algorithm In Parallel Environment, Tjah Jadi May 1988

Implementing Ray Tracing Algorithm In Parallel Environment, Tjah Jadi

Dissertations and Theses

Ray tracing is a very popular rendering algorithm in the field of computer graphics because it can generate highly-realistic images from three-dimensional models. Unfortunately, the computational cost is very expensive. To speed up the rendering process we present both static and dynamic scheduling (balancing) strategies for a multiprocessor system. Hence, the load balancing among the processors is the most important problem in parallel processing. The implementation of the algorithm is based on a modified octree structure.


Dc-Excited Cw Co₂ Metal Waveguide Laser, Fahad Saleh Al-Mashaabi May 1988

Dc-Excited Cw Co₂ Metal Waveguide Laser, Fahad Saleh Al-Mashaabi

Dissertations and Theses

A novel design for a DC excited cw CO2 metal waveguide laser has been developed in which a slotted hollow-cathode in a transverse discharge also doubles as a metal waveguide. This design has been implemented in a compact design that produces up to 1 watt of cw, 10.6 μm radiation. The discharge characteristics, laser gain and laser output has been studied as functions of various discharge parameters. The advantages of the new transverse discharge of the slotted hollow cathode geometry include low voltage, positive impedence and high optical gain. Overall efficiency is comparable with those of conventional longitudinal CO …


Birefringent Light Scattering In Electrooptic Plzt Ceramics, Mark David Ivey May 1988

Birefringent Light Scattering In Electrooptic Plzt Ceramics, Mark David Ivey

Electrical and Computer Engineering ETDs

A study of visible light scattering in thin plates of ceramic PLZT is presented. A scattering model is developed on the basis of multiple refraction from randomly oriented walls in a birefringent medium. The results of this model are compared to measurements of longitudinal-mode light scattering from thin (250 - 650µm) PLZT plates of three different ceramic compositions. The observed light scattering by these ceramics is attributed to two mechanisms which are linked to field-induced ferroelectric anisotropies. The first, referred to by this study as "uncorrelated birefringence," corresponds to the independently-random changes in the index ellipsoid known to occur at …


Bioavailable Phosphorus In The Bear River System, Utah, Kenneth Warren Barker May 1988

Bioavailable Phosphorus In The Bear River System, Utah, Kenneth Warren Barker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The bioavailable fraction of phosphorus (BAP) in the lower Bear River system waters was investigated. BAP plays a critical role as the limiting nutrient for algal production and eutrophication in proposed reservoirs in the Bear River system. The Bear River system has a hardness ranging between 180-240 mg/L as CaCO3 which significantly affects BAP.

BAP estimation was done by a modified Selenastrum capricornutum Printz Algal Assay Bottle Test. The algal bioassay is considered the best estimator of BAP because no chemical tests or indicator parameters are available. Autoclaving and UV radiation were found to be unacceptable means for sterilization …


Evaluation Of Spatially-Distributed Snowpack Estimation Using Pattern Recognition, Cheng-Hua Leu May 1988

Evaluation Of Spatially-Distributed Snowpack Estimation Using Pattern Recognition, Cheng-Hua Leu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A procedure for spatially-distributed snowpack estimate is proposed and evaluated herein. This procedure is divided into two parts, off-line and on-line parts. The off-line procedure uses Fuzzy c-Varieties (FCV) algorithms to perform the watershed classification based on Landsat TM data and a digital elevation model and estimate influence coefficient for all pixels in the watershed. Through the concept of influence coefficient, a set of prototypical points can be selected and located. The on-line procedure estimates snowpack properties at these prototypical points and then transforms them to estimates of snowpack properties at any point in the watershed. To effectively evaluate this …


A Hydrological Characterization Of A Zero-Order Basin In Volcanic Hillslope Terrain, Neil A. Mock May 1988

A Hydrological Characterization Of A Zero-Order Basin In Volcanic Hillslope Terrain, Neil A. Mock

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hydrologists have displayed a renewed effort towards understanding the complexity of runoff generation and its association with basin structure. Basin structure is defined as the complex geomorphological, vegetation, and soil characteristics that make up and distinguish the physical nature of a drainage basin. Zero-order basins are an integral part of watershed structure because they furnish the capacity to store and transmit snowmelt and rainfall. By definition, zero-order basins are sub-basins which are depressions in the surf ace and shallow bedrock topography. This study involves a space time characterization of a zero-order basin in fractured media located in southwest Idaho.

The …


Investigation Of Accuracy Limitations Of The Ionospheric Plasma Frequency Probe And Recommendations For A New Instrument, Mark Duane Jensen May 1988

Investigation Of Accuracy Limitations Of The Ionospheric Plasma Frequency Probe And Recommendations For A New Instrument, Mark Duane Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A unique wide-range voltage-controlled oscillator (VCO) has been part of the plasma frequency probe (PFP) for many years. The uniqueness of this VCO is how it is tuned with an electronic tuneable inductor in conjunction with a varactor diode. Though the PFP has been utilized successfully for rocketborne ionospheric electron density measurements, fine resolution data was limited by strange frequency jumps (approximately 5 percent uncertainty in electron density) which have appeared in flight results. This thesis examines the cause of some of these jumps, and shows they are instrument related and more particularly caused by the ferrite tank inductor core …


Electromagnetic Field Variations In The Activation Of Bone Cell Synthesis, Gary Ketcherside Apr 1988

Electromagnetic Field Variations In The Activation Of Bone Cell Synthesis, Gary Ketcherside

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract Not Included]


A Feasible Direction Procedure For General Multiple Objective Optimization, Wen-Tsia Liu Apr 1988

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 …


The Evaluation Of Efficiency Determination Of Screening Device (Pressure Screen) By Image Analysis, Rajeev Kumar Goyal Apr 1988

The Evaluation Of Efficiency Determination Of Screening Device (Pressure Screen) By Image Analysis, Rajeev Kumar Goyal

Masters Theses

The Omnicon 3600 image analyzer was used in the study of the evaluation of screening efficiency determination methods. It is very difficult to get a good over all contaminant mass balance across a pressure screen because of the factors involved such as sampling around a screen, time spent in collecting the samples, and possible size reduction of the contaminants by the pump and screen. The image analyzer gives the contaminant analysis in terms of the total number of particles, total area of all the particles, the mean particle area and a histogram of the contaminant size distribution. The histogram data …


A Simulation Study Of A Space-Borne Optical Disk Mass Memory System, Kenny G. Chen Apr 1988

A Simulation Study Of A Space-Borne Optical Disk Mass Memory System, Kenny G. Chen

Electrical & Computer Engineering Theses & Dissertations

Issues concerning space-borne applications of an optical disk mass memory system (ODMMS) are investigated through computer simulation. The simulation model is developed according to a current description of the ODMMS with certain application constraints. The results are examined in terms of system modularity, multi-user data rate buffering, disk module access, and read/write file management. The conditions and requirements for future disk controller designs are indicated in the simulation results.


Self Consistent Model Of The Glow Discharge, Hao Chen Apr 1988

Self Consistent Model Of The Glow Discharge, Hao Chen

Electrical & Computer Engineering Theses & Dissertations

The strong spatial variation of the electric field intensity in the vicinity of the cathode of a gas discharge requires the use of microscopic methods to describe the nonequilibrium behavior of the electron dynamics in this region. A one-dimensional Monte Carlo code was developed. It allows one to obtain the distribution of the electron drift velocity and rate coefficients for a given electric field intensity in the cathode fall. The results of this calculation are used to find the density distribution of charged particles in this region and consequently, by means of Poisson's equation, a corrected electric field intensity. In …


Full-Potential Integral Solutions For Steady And Unsteady Transonic Airfoils With And Without Embedded Euler Domains, Hong Hu Apr 1988

Full-Potential Integral Solutions For Steady And Unsteady Transonic Airfoils With And Without Embedded Euler Domains, Hong Hu

Mechanical & Aerospace Engineering Theses & Dissertations

The integral equation solution of the full-potential equation is presented for steady and unsteady transonic airfoil flow problems. The method is also coupled with an embedded Euler domain solution to treat flows with strong shocks for steady flows.

For steady transonic flows, three integral equation schemes are well developed. The first two schemes are based on the integral equation solution of the full-potential equation in terms of the velocity field. The Integral Equation with Shock-Capturing (IE-SC) and the Integral Equation with Shock-Capturing Shock-Fitting (IE-SCSF) schemes have been developed. The IE-SCSF scheme is an extension of the IE-SC scheme, which consists …


Investigation Of Supersonic Chemically Reacting And Radiating Channel Flow, Mortaza Mani Apr 1988

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 …


Large Planar Maneuvers For Articulated Flexible Manipulators, Li-Farn Yang Apr 1988

Large Planar Maneuvers For Articulated Flexible Manipulators, Li-Farn Yang

Mechanical & Aerospace Engineering Theses & Dissertations

An articulated flexible manipulator carried on a translational cart is maneuvered by an active controller to perform certain position control tasks. The nonlinear dynamics of the articulated flexible manipulator are derived and a transformation matrix is formulated to localize the nonlinearities within the inertia matrix. Then a feedback linearization scheme is introduced to linearize the dynamic equations for controller design. Through a pole placement technique, a robust controller design is obtained by properly assigning a set of closed loop desired eigenvalues to meet performance requirements. Numerical simulations for the articulated flexible manipulators are given to demonstrate the feasibility and effectiveness …


Integral Equation Solution Of The Full Potential Equation For Three-Dimensional, Steady, Transonic Wing Flows, Li-Chuan Chu Apr 1988

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 Apr 1988

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 …


Multaid, A Consultant For Multi-Microprocessor Network Selection, Bernabe Javier Arruza Jan 1988

Multaid, A Consultant For Multi-Microprocessor Network Selection, Bernabe Javier Arruza

Theses

A knowledge based system has been developed to enable an architectural designer to select an adequate interconnection network to be utilized in a parallel or distributed processing system. It is implemented using the Knowledge Engineering Environment, K.E.E., package from IntelliCorp.

The user will interact with the system through symbolic representation. From the selected symbols, the knowledge base system will identify the most appropiate network for the given application. The system will display the network topology along with all the information and results of all pertinent calculations corresponding to the given network. The program will also display the rule driven search …


Multichannel Priority Interrupt System, Claudio Bernal Jan 1988

Multichannel Priority Interrupt System, Claudio Bernal

Theses

There is in our current industrial milieu an increasing demand for systems capable of detecting and processing a large number of analog signals for the computer.

The present work offers an approach for a multichannel real time acquisition system which will find a wide variety of applications in machine automation, process control, musical instruments, remote sensing, etc.

The system presented in this thesis follows traditional instrumentation architecture and implements that architecture around the latest microcontroller, the 8052. The system, capable of assigning a processing priority to a large number of incoming events, is demostrated for 40 channels. It is fast …


The Switch Capacitor Biquad Filter And It's Application On Active Filter Design, Sung-Chiang Chang Jan 1988

The Switch Capacitor Biquad Filter And It's Application On Active Filter Design, Sung-Chiang Chang

Theses

The purpose of this subject is to use the programmable switch capacitor filter to design a traditional analog filter which usually cause a tedious job on finding a group of values for resistors and capacitors. We start from the basic concept of switch capacitor, then we learn to use auxiliary equipment to design a filter. To design the desired filter, first, we have to find the s-domain transfer function, then transfer it to the z-domain. After we found the coefficients of z-domain transfer function, we have to implement this on the auxiliary equipment. Then we will get the desired filter.


Reliability Of Existing Bridge Inspection And Evaluation Procedures, Leroy R. Klouser Jan 1988

Reliability Of Existing Bridge Inspection And Evaluation Procedures, Leroy R. Klouser

Theses

In general, bridge inspection is subjective since visual observation and the basic inspection tools cannot reveal hidden structural deterioration, such as corrosive and delaminated rebars embedded in the concrete. Based on the NJDOT SI&A report, a scale (9 to 0) is used in rating five bridge components. This approach seems reasonable, since the time span, manpower and cost are limited throughout the counties of New Jersey. On the other hand, based on the scaling system, the SI&A reports can vary depending upon the exposed surface appearance and the experience of the bridge inspector.

Water, de-icing agents, freezing and thawing cycles …


Synthesis And Characterization Of A Novel Blocked Isocyanate Dental Adhesive Based On Diphenylmethane - 4, 4' - Diisocyanate, Yangming Lin Jan 1988

Synthesis And Characterization Of A Novel Blocked Isocyanate Dental Adhesive Based On Diphenylmethane - 4, 4' - Diisocyanate, Yangming Lin

Theses

The dental adhesive monomers based on diphenylmethane - 4,4 - diisocyanate (MDI) were prepared and studied in this research. The diisocyanate, MDI, was first reacted with hydroxyethyl methacrylate (HEMA) to form an intermediate adduct. This adduct had an active isocyanate end group. It was then bonded with o-chlorophenol (OCP), a blocking agent, to produce a blocked isocyanate monomer.

The new blocked isocyanate (HEMA-MDI-OCP) was found to have an average value of more than 1200 psi in tensile tests measuring its adhesion to dentin slices.


Programming For The Prediction Of Thermodynamic Phenomena, One Kwon Rim Jan 1988

Programming For The Prediction Of Thermodynamic Phenomena, One Kwon Rim

Theses

A Thermodynamic Calculation Program was developed. The program contains the calculation procedure for VAPOR/LIQUID EQUILIBRIUM(Isothermal P-X data and T-X data), HEAT-OF-MIXING(liquid mixture data) and LIQUID/LIQUID EQUILIBRIUM SEPARATION data. The program may optionally use the Knox Molecular(GAM), UNIQUAC, NRTL, Wilson and Redlich-Kister equations, and is prepared to accept any kind of model which will be developed in the future. This program also performs parameter file creation, parameter input, updating of parameters, and is structured to allow implementation of data regression when program is updated. Comparison and analysis of each function were executed using this program. It was revealed that VLE(Vapor-Liquid Equilibrium) …


Hydrodechlorination Reactions Of Trichloroethylene And 1,1 1, Trichloroethane Over Alumina Supported Palladium Catalysts, And, Trichloroethylene Over Nickel Catalyst, Atul R. Shah Jan 1988

Hydrodechlorination Reactions Of Trichloroethylene And 1,1 1, Trichloroethane Over Alumina Supported Palladium Catalysts, And, Trichloroethylene Over Nickel Catalyst, Atul R. Shah

Theses

The primary objective of this study was to evaluate the viability for conversion of chlorocarbon wastes solvents into useful hydrocarbons and HCl by catalytic reduction. The second objective was to investigate the pathways for these hydrodechlorination reactions over the chosen alumina supported Palladium and nickel catalysts as well as determine selectivities, product distribution, and deactivation mechanism.

Reactions of trichloroethylene with hydrogen over alumina supported palladium catalyst was studied in temperature range 40°C to 57°C at one atmosphere total pressure. The major products observed were ethane and (cis) 1,2 dichloroethylene with trace products chloroethylene, chloroethane and (trans) 1,2 dichloroethylene. At the …


Thermal Desorption Of Hazardous And Toxic Organic Compounds From Soil Matrices : Dichloromethane, Chloroform, Benzene, Toluene, 1-Chloronaphthalene, 1, 2, 4-Trichlorobenzene, Arun S. Chemburkar Jan 1988

Thermal Desorption Of Hazardous And Toxic Organic Compounds From Soil Matrices : Dichloromethane, Chloroform, Benzene, Toluene, 1-Chloronaphthalene, 1, 2, 4-Trichlorobenzene, Arun S. Chemburkar

Theses

This research project was undertaken to understand the process of desorption/removal of organic compounds from soil matrices under the influence of temperature and gas purging. The project was divided in two parts :

A. Plug deposition experiments: Columns packed with soil matrices were purged with an inert gas under isothermal conditions. Organic compounds were then introduced as a plug on the front of the column by on-line injection. The rate of passage (due to sequential adsorption/desorption) of the plug through the various soil matrices was measured by a gas chromatograph equipped with a flame ionization detector (FID). The compounds studied …