Engineering Commons^™

Behavior Of Slender High Strength Reinforced Columns Under Biaxially Eccentric Loading, Pei-Shiun Wu

Theses

The advantage of using high strength concrete is to reduce column sizes and to increase stiffness. At present there are not any available design aids and the code provisions that provide adequate guidelines for the design of slender columns in high strength concrete.

A total of four 3 in. by 3 in. dimension, 4 ft. length high strength concrete specimens were casted, cured and tested till failures in a vertical pinned-ended configuration.The experimental results were compared with the analysis using Hsu failure surface equation.

Moment, curvature and load deflection cures were obtained successfully from the present experimental tests. These curves …

Behavior Of Slender High Strength Steel Fiber Reinforced Concrete Columns Under Combined Biaxial Bending And Axial Compression, Tzuoh-Jaw Wu

Theses

A total of four slender high strength steel fiber ( 20 vol. hooked ends 1 in and 2 in ) reinforced concrete columns were casted, cured and tested to failure under biaxially eccentric load us—KT MTS testing system. The experimental load-deflection behavior exhibits not only the ascending branch but also the descending branch of the load and deformation curves.

The experimental ultimate load capacity was analyzed by the equation of Failure Surface Method developed by Hsu. recently, the result shows that the analysis method is able to predict the ultimate load value for biaxially loaded slender concrete columns.

For biaxially …

Temperature Dependent Current-Voltage Characteristics In Thin Sio2 Films, Jin Zhao

Theses

An analysis of the Fowler-Nordheim tunneling (FNT) theory and its application to temperature dependent current-voltage characteristics, of very thin films of SiO₂ on silicon, is presented. The final results are believed to provide the most complete examination of FN emission theory and predict the breakdown electric field in thin SiO₂ films. The role of the roughness, at the Si-SiO₂ interface, in determining the FNT current and breakdown mechanisms in metal-oxide-semiconductor (MOS) structures are also discussed.

Automatic Infrared Inspection Of Solder Joints On Mounted Circuit Boards, Ken Kekuan Zhou

Theses

This thesis reports the research work on automatic infrared and visual light inspections of solder joints on printed circuit boards (PCBs) utilizing an image processing system and statistical pattern recognition techniques.

A small scale image processing system, consisting of a SUN workstation and several DATACUBE modules, is set up for the research. Software packages for imaging, displaying and solder joint inspection are developed and ready for public usage.

The capability of infrared inspection for solder joints on PCBs is demonstrated. The fusing of infrared and visual light imagery for the inspection is shown to offer better results than that obtainable …

An Investigation Of The Dynamics Of Abrasive Waterjet Formation, Md. Ekramul Hasan Khan

Theses

The aim of this research was to investigate the jet formation and the jet behavior, as characterized by the velocity field, the force exerted by the jet on a work-piece and the jet geometry. The velocity and force distributions were measured using a laser transit anemometer (LTA) and a piezoelectric force transducer (PFT) respectively for constant water pressure (334.6 MPa) supply. The jet structure and its instantaneous behavior were visualized by the used of high speed filming. LTA and PFT measuring techniques were established and verified. The measurements were performed under different operating conditions. It was found that at a …

Investigation Of Mixed-Made Fracture In Concrete, Stylianos C. Aniftos

Theses

This study is aimed at evaluating the failure characteristics of concrete in the notched beam configuration. In general, for Mode I failure tension is commonly encountered. However, in the area of high shear stress, it remains to be a question whether shear or Mode II failure exists. Researches carried out in the past decade confirmed the existance of both Mode I and Mode II failure. It is the objective of this investigation to clarify this failure characteristics using FRANC an interactive fracture mechanics software.

The investigation carried out in this study used the experimental results of Bazant and Pfeiffer (3) …

Effect Of Inorganic Salts On Adsorption Process, Pai-Yuan Horng

Dissertations

`Small amounts (0.0 M-0.01 M) of inorganic salts (sodium chloride, calcium chloride, and aluminum chloride) added to bituminous coal fly ash and granular activated carbon in batch adsorption treatment experiments indicates the possibility of enhancing the extent and rate of adsorption process.

Experiments were conducted on aqueous solutions of highly toxic and hazardous chemicals, those include : phenol, benzene, toluene, isopropyl alcohol, and methyl-isobutyl ketone. Single and multiple solute systems were examined separately. Removal of organic pollutants was measured using a Flame Ionization Detector Gas Chromatograph.

This study investigated the role of inorganic salts during the sorption process. The results …

Synthesis And Study Of Polymers Containing Inorganic Ions, Lateef Aderoju Ibikunle-Sofoluwe

Theses

Cupric and ferrous polyacrylates have been prepared and studied. It was thought that partial reduction of Cu²⁺ or Fe³⁺ or oxidation of Cu⁺ or Fe²⁺ might result in semiconducting behavior but no such effect has been observed. Nevertheless, the results obtained are of considerable interest. Quantitative gravimetric and volumetric studies of cupric polyacrylate precipitation from varying molar ratios of cupric chloride and sodium polyacrylate in aqueous solution have shown that the only product formed is Cu(PA)₂ (Where PA represents an acrylate mer in polyacrylate). The insolubility of the product indicates that much of the Cu …

Dioxin Formation : Thermodynamics And Reaction Pathways During The Oxidation/Incineration Of Chloroaromatics, Sanjiv Narendra Patel

Theses

Enthalpy, entropy and heat capacity property estimation for cyclic molecules using Benson's group additivity method require the use of ring correction terms. Ring correction terms are estimated from the thermodynamic properties of the cyclic molecule being considered. In the absence of litera¬ture values a procedure is proposed to predict these thermodynamic values.

Benson's Group additivity method does not fully account for the interactions between bulky group or atom substituents on the aromatic ring. In order to have accurate thermodynamic properties for these compounds, a data base is generated with ortho, meta and Para interactions for (Cl-Cl), (Cl-OH), (OH-OH), (CH_{3 …}

Formation And Characterization Of Thin Superconducting Y-Ba-Cu-O Films, Gyusuk Kim

Theses

Thin Y-Ba-Cu-O superconducting films were fabricated reproducibly on MgO (100) substrates by two different processes ; (1) deposition at a low substrate temperature fiom a single sintered YBa₂Cu_3.3O_x target using RF diode reactive sputtering followed by a post-annealing at around 830 ° C ; (2) deposition at the crystallization temperature under oxidizing atmosphere. The superconducting properties of films deposited by process (1) and (2) were studied. The variation of film composition and thickness as a function of distance from the target gas pressure and distance between target and substrate was studied. The Dependence of the …

Three-Dimensional Stress Analysis Of The Femoral Midshaft Utilizing Computed Tomography And Finite Element Analysis, Peter F. Marion

Theses

Recent advances in computer technology have provided both the medical community and biomedical engineers with a method for noninvasively evaluating the internal structure in a way not previously possible. A three-dimensional finite element model of a midshaft section of the femur was generated, utilizing Computed Tomography scan data. The CT scan data file was introduced into an edge-detection algorithm and a file of geometric edge data was generated. This edge data was introduced into a solid modeling Computer-Aided Engineering software package to produce a three-dimensional solid model. A mesh generation procedure was then used to create a three-dimensional finite element …

Adaptive Fir Digital Filter Design And Simulation In The Noise Reduction System, Jack Jiabing Pang

Theses

The adaptive FIR digital filter is designed to suppress the noise in the tape recording and audio communication systems. The cutoff frequency of the digital FIR filters can be varied adaptively depending on the energy level of the input signal. In audio communication, especially, in tape recording systems, the noise obviously gets much bigger, when the frequency band of the system increases. The noise reduction system makes use of a phenomenon called masking, where the big signal-to-noise ratio makes human ears not sensitive to the noise. In a constant interval time, the system detects the signal level and compares the …

Computer Integrated Manufacturing : A Systems Approach For Small Manufacturing Enterprises, Sanjeet Jagdish Patel

Theses

This work is dedicated to small manufacturing enterprises seeking to explore Computer Integrated Manufacturing (CIM) technology, which is the recent trend in the manufacturing world. The main therie of this thesis is to improve productivity, product quality and reliability and reduce costs by integrating various disciplines.

Generic manufacturing functions including order entry, inventory control, manufcturing planning and control, automated drafting, direct numerical control etc. were enhanced by the effective utilization of low end workstations grouped together into a network and equipped worth industry standards software.

The introduction of computers into a manually resourced system yielded significant results such as reduction …

Sputter Deposition And Characterization Of High Tc Superconducting Thin Films, Vipulkumar Patel

Theses

Preparation of thin superconducting films by direct RF sputter deposition on Si, MgO, SrTiO₃ and quartz substrates and silver and Sl3N4 buffer layers (deposited on silicon substrates) was studied. To study resistance versus temperature characteristics of thin films and bulk materials, a computerized measurement system was developed. 1-1.5 pm thick YBaCuO films deposited on Si₃N₄/Si were found to be insulating with room temperature resistance higher than 236KΩ, while films with Ag as a buffer and/or a passivating layer exhibited metallic behavior with room temperature resistances lower than 700mΩ. The area directly under the 2.25 inches …

Testing And Modelling Of The Cleaner Wick System For In-Situ Treatment Of Contaminated Groundwater Plumes, Sanjiv I. Shah

Theses

The cleaner wick system, a modification of wick drains; a technology in recent use to consolidate low permeability soils, is proposed to treat contaminated groundwater plumes. Laboratory experiments on surrogate contaminants produce satisfactory results. Theoretical models are developed utilizing the cleaner wick system to treat volatile organic contaminants by air stripping and adsorption on granular activated carbon.

Treatment Of Trucking Station Wastewater By Two-Phase Anaerobic Digestion System And Rotating Biological Contactor, Tzu-Wen Uen

Theses

The wastewater produced as a result of trucking station activities has some major characteristics such as high COD (26,880 mg/1-42,925 mg/1) and BOD (12,278 mg/1-7,265 mg/1), high COD to BOD ratio (3.49-3.69), high pH range (3.72-11.7), and high grease content (480 mg/1-1,960 mg/1). Therefore, prior to any treatment, it is important to provide some sort of pre-treatment for pH adjustment and grease/oil removal.

The present laboratory investigation has indicated that successful treatment and purification of the subject wastewater is possible using two-phase anaerobic digestion system followed by rotating biological contactor. More than 90% of both COD and BOD was removed …

Development Of A Flexible Control And Automated Data Acquisition System For Wear Testing, Wen-Long Yao

Theses

The purpose of this work is to develop a flexible control and automated data acquisition system for wear testing procedure. A programmable logic controller (PLC) control philosophy and PC-based automated data acquisition system (DAS) were designed and organized for the wear testing machine in Surface Engineering Laboratory of Mechanical Engineering Department. The designed and performed separation of control and acquisition strategies saved a lot of engineering interface communication time. Several instrumentations and mechanism designs, such as selected RTD sensor, modified testing shoe for RTD installation, designed controlled lubrication mechanism, and designed load-unload mechanism, have been performed to fulfill the concerned …

Kinetic Mechanism Of The Reactions Of Dichloromethane And Chloroform With Atomic Hydrogen At Low Pressure And Room Temperature, Jia-Ling Linda Young

Theses

The reaction mechanism of dichloromethane reaction (DCM) with atomic hydrogen in a flow reactor at room temper¬ature (300 K) and low pressure (2.1 - 2.7 torr), argon bath gas, has been developed in this research to analyze the above reaction system. The important addition reactions of radicals (or atoms) to olefins and the radical/radical (atom/radical) combination reactions have been analyzed using the bimolecular version of the Quantum-Rice-Ramsperger-Kassel (QRRK) theory.

The detailed reaction mechanism satisfactorily fits the experimental data for the reagent (DCM) conversion from previous experimental over a initial ratio (atomic hydrogen to dichloromethane) range of 6.8 to 40. The …

Application Research On Wastewater Reuse For Petrochemical Refining Industry In Taiwan, Lih-Shyan Lee

Theses

Nowadays water conservation and pollution abatement are needed to provide increasingly higher levels of treatment for industrial wastewaters.

Reducing treatment costs give us the incentive to minimize the volume of Wastewater effluent. Also, the national goal of zero discharge of pollutants to the waterways by 1985 provided further incentive -to minimize the flow of wastewaters.

A successful treatment of the wastewater discharged from the secondary effluent of the petroleum refinery plant to economically acceptable conditions offers a challenge to our technology.

Through this research, it is concluded that the excellent effluent water qualities produced from filtration and granular activated carbon …

Fault Tolerant Benes Networks, Manoj Bhatnagar

Theses

A fairly large number of fault tolerant topologies have been proposed for the multistage interconnection networks in the recent years. However very few of these schemes have focused on the Benes network. This thesis presents two new fault tolerant architectures for the Benes network. The thesis includes algorithms to construct these fault tolerant networks from a Benes network and the reconfiguration procedure in the event of a fault. The hardware characteristics of both the fault tolerant networks have been analyzed and compared.

Uniformity Corrector And Signal Processing For A 160 X 244-Element Ir-Ccd Camera With Ptsi Schottky-Barrier Detectors, Paul D. Blume

Theses

An off-set-type, one point response uniformity corrector and the associated signal processing circuits was developed to be used for a 160 x 244-element IR-CCD camera with PtSi Schottky-barrier detectors. Image sensors with PtSi Schottky-barrier detectors exhibit two types of noise in the displayed video output, a temporal noise and a spatial fixed pattern noise. The performance of the image sensor, limited by the spatial noise which obscures low contrast detail and limits camera sensitivity, can be improved by a uniformity corrector. The uniformity corrector was constructed to substantially reduce the spatial noise in the output display by digitally subtracting a …

The Magnetotransport Analysis Of Hemt Structures At Low Fields, Naghmeh Nouri

Theses

On the basis of a study on numerous HEMT structures, a simple and useful technique was established for the characterization of 2DEG layers. This technique utilizes the magnetic field-dependence of the resistivity and Hall coefficient of the HEMT structure, to determine the values of the sheet density and mobility of 2DEG in the presence of other parallel conductive layers. This method of analysis was compared with previously used techniques such as Shubnikov-de Haas and the etch removal of the parallel conductive layers. Through this comparison and several measurements it was found that this procedure gives reproducible values for the 2DEG …

Desiccation And Permeability Of Backfill Materials In Soil-Bentonite Walls, Hemendra J. Moradia

Theses

Soil-Bentonite Walls offer a cost effective solution to many groundwater problems in new and remedial work projects such as hydraulic barriers in dams, dewatering large soil cuts, and as part of pollution control systems around hazardous waste landfills. However, the performance of soil-bentonite walls in environments other then fresh water types is still a matter of great controversy. In recent years, some data on soil-bentonite backfill have became available. The data indicate change in properties of these walls with time of exposure and concentration of chemicals found in leachates. However, no research work is available in the literature on the …

Simulation And Design Of Field Emission Diode, Yun Yuan

Theses

A new generation of microelectronic devices utilizing vacuum field emission cathodes becomes surging interest in recent years. This paper concentrates on the study of the field emission diode — a basic vacuum microelectronic device. The field emission efficiency, current spatial distribution and time dispersion of conical tips and wedges of various geometrical shapes are compared and calculated by analytical methods and computer simulations. Two field emitter heating effects, namely the Joule heating and Nottingham effect, are discussed theoretically. All the simulation results in this paper are performed on 386 based personal computer. The limiting memory space of PC induced simulation …

Infrared Tv Camera With Ptsi Schottky-Barrier Detectors, Steven J. Blume

Theses

An infrared TV camera was developed for operating various sizes of Schottky-barrier IR-CCD image sensor chips. A digitally programmable frequency synthesizer is used so that the camera has the flexibility of using a 160 x 244 or 320 x 244 image sensor developed at the David Sarnoff Research Center. The outputs of the camera are compatible with an XYZ monitor, a standard TV monitor, and a computer workstation. Operation of the camera was demonstrated with a 160 x 244 image sensor producing an output on a standard TV monitor. Performance of the IR-TV camera system was investigated by evaluating CCD …

Investigation Of The Fluid Dynamics Of Bioprosthetic Heart Valves, Carol A. Calta

Theses

There is a strong connection between altered arterial blood flow and vascular disease. The presence of disturbed flow and/or excessive turbulence is an indication of an abnormality within the cardiovascular system. The examination of cardiovascular fluid dynamics provides insights into the working of the cardiovascular system and ways to improve the design of implantable bioprosthetic valve designs. This investigation examines the fluid flow of arterial systems, and ways to apply this knowledge to the valves implanted into patients.

This thesis involves an investigation of the testing of bioprosthetic valves within simulated left heart flow loops. These systems include pulse duplicators …

Performance Analysis Of A Dynamic Reservation Multichannel Local Area Network, Abubakar A. Ibrahim

Theses

A reservation multiaccess protocol. is proposed to be used on multichannel local area networks. This protocol is advantageous for networks supporting integrated services. The delay and throughput performance for message transmission are obtained by analysist The delay performance of the protocol is similar to the M-CSMA/CD/IC multichannel network proposed by Marsan and Roffinella. It is found that the reservation protocol can provide better throughput-delay characteristics when the fraction of the total available bandwidth allocated to data is increased. It is also observed that the maximum throughput increases with the increase in the number of channels when the total bandwidth is …

Analytical And Experimental Study Of Robotic Peg-In-Hole Insertion, Yilun Jia

Theses

A mathematical model of robotic peg-in-hole insertion, which relates insertion force and moment to manipulator compliance and geometric constraints, is presented. Based on this model, the effects of manipulator compliance and geometric and positional parameters on the insertion are studied. The complete expressions for determining the insertion forces and moment as well as the peg kinematics are derived. The study is helpful to reducing insertion force and moment and avoiding possible jamming during the insertion process. The model is verified experimentally on the IBM 7540 robot.

The Design Of Decentralized Optimal Regulator Systems Using Matrix Minimum Principle, Sunny Lai Yick

Theses

This research considers the design of linear, time-varying regulator systems using Matrix Minimum Principle in the frame work of decentralized control theory. The regulator system is modeled in terms of state equation with multiple controllers. Each controller works cooperatively to optimize a common quadratic performance index. An additional constraint is imposed such that the controllers are linear time-varying functions of the outputs.

Necessary and sufficient conditions for optimality of the system are provided by the Matrix Minimum Principle and Hamilton-Jacobi Theory.

Two examples are developed to illustrate the concept.

Correlation Between Particle Velocities And Conditions Of Abrasive Waterjet Formation, Wei-Long Chen

Dissertations

The velocities of water and abrasive particles in abrasive waterjet(AWJ) were measured by the use of Laser Transit Anemometer(LTA). A setup for the velocity measurement was constructed and a statistical technique was used to improve the accuracy of the velocity determination. A comparison of the magnitude of velocities determined by LTA, Piezoelectric Force Transducer and Schlieren Photograph clearly indicates the feasibility of the use of LTA.

The velocities of water and particles were measured for different diameters of water and slurry nozzles, abrasive mass flow rates and particle sizes. The performed experiments enabled us to evaluate the effects of conditions …