Engineering Commons^™

A Comparative Study Of The Stress Concentration Factors Arising Between Two Equal, Nearly Intersecting, Perpendicular, Pressurized Holes In An Infinite Solid With Those Arising Due To An Infinite Series Of Such Holes, Paul J. Drogowski

Masters Theses

Finite element analysis is used to determine the stress concentration factors arising from two equal, perpendicular, nearly intersecting, pressurized holes in an infinite solid while varying the distance and pressure ratios between the holes. The results are compared and contrasted with those previously obtained for an infinite series of such holes. A ratio of the distance between the holes to the diameter of the holes at which the holes can be considered to be single holes in an infinite solid is determined. A study is performed to determine a correlation between the location of the region of maximum stress and …

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Building Services Engineering

No abstract provided.

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Building Services Engineering

No abstract provided.

Bs News

Building Services Engineering

No abstract provided.

Design Of Automotive Structural Components Using High Strength Sheet Steels Effect Of Strain Rate On The Structural Strength Of Cold-Formed Steel Hybrid Beams, Chi-Ling Pan, Wei-Wen Yu

CCFSS Library (1939 - present)

INTRODUCTION In cold-formed steel design, local buckling is one of the major design features because of the use of large width-to-thickness ratios for compression elements. For the purpose of determining the load-carrying capacity of automotive components, the effective width approach has been used. In view of the fact that the design criteria for effective design width included in the AISI Automotive Steel Design Manual 1 are based on the test results for static loading condition, an investigation was conducted at University of Missouri-Rolla from January 1988 through December 1991 to study the validity of these effective design width formulas for …

Finite Element Simulation Of Elastic Wave Propagation In Porous Rock Media, Ahmed Kamal Kamel

Archived Theses and Dissertations

No abstract provided.

Reduction Of Lead Pollution From Vehicular Emissions In Greater Cairo, Sherif Kamal Saleh

Archived Theses and Dissertations

No abstract provided.

Composite Beam Analogy Fracture Model (Cbafm) : A Non-Linear Fracture Mechanics Model For Concrete, Mohammed Enamul Haque

Dissertations

The main objective of this dissertation is to develop a simple non-linear fracture mechanics model for the determination of fracture mechanics parameters for concrete, such as fracture process zone length (rp), critical fracture energy release rate (Gic), critical stress intensity factor (KO and fracture energy (GF). The fracture process zone (FPZ) is modeled as a damaged non-elastic cohesive band where the extent of damage due to microcracking varies from no damage at the boundary of FPZ to complete crack surface separation at the notch or macro-crack tip. The proposed method can predict theoretically both the pre-peak and post-peak load versus …

Grain-Size Optimization And Scheduling For Distributed Memory Architectures, Jing-Chiou Liou

Dissertations

The problem of scheduling parallel programs for execution on distributed memory parallel architectures has become the subject of intense research in recent, years. Because of the high inter-processor communication overhead in existing parallel machines, a crucial step in scheduling is task clustering, the process of coalescing heavily communicating fine grain tasks into coarser ones in order to reduce the communication overhead so that the overall execution time is minimized.

The thesis of this research is that the task of exposing the parallelism in a given application should be left to the algorithm designer. On the other hand, the task of …

Investigation Of Hybrid Message-Passing And Shared-Memory Architectures For Parallel Computer : A Case Study : Turbonet, Xi Li

Dissertations

Several DSP (Digital Signal Processing) algorithms are developed for the MIT TurboNet parallel computer. In contrast to other parallel computers that implement exclusively in hardware either the message-passing or the shared-memory communication paradigm, or employ distributed shared-memory architectures characterized by inefficient implementation of the shared-memory paradigm, the hybrid architecture of TurboNet supports direct, efficient implementation of both paradigms. Three versions of each algorithm are developed, if possible, corresponding to message-passing, shared-memory, and hybrid communications, respectively. Theoretical and experimental comparisons of algorithms are employed in the analysis of performance. The results prove that the hybrid versions generally achieve better performance than …

Biodegradation Of Mixed Wastes : Basic Kinetics And Reaction Engineering For Cyclic Reactor Operation, Kung-Wei Wang

Dissertations

This study dealt with the determination of the detailed kinetics of the biodegradation of mixed substrates by pure cultures, and with reaction engineering studies of bioreactors employed in treatment of substitutable substrates under cyclic operation.

In the first part of the study the degradation of phenol and 4-chlorophenol (4-CP) by two strains of Pseudomonas species was investigated. Strain P. putida 0 was found to be capable of utilizing both phenol and 4-CP as sole carbon and energy sources. This suggests that this strain follows the ortho-cleavage pathway for the aromatic ring. Strain P. putida N could grow on phenol, and …

Effects Of Ergonomic Worksite Changes On Risks For Cumulative Trauma Disorders Of The Upper Body In An Assembly And Press Operation Job, David B. Mahone

Theses

Cumulative trauma of the upper body is associated with a variety of individual and job factors. An effort to optimize the human-hardware interface to minimize cumulative trauma is favored. Workers in a set of jobs had complained about hand/wrist and shoulder discomfort. One job was selected for testing alternate machine controls and worksite layout. Electromyography was used to test muscle activity, and photogoniometry was used to measure posture.

For the group of ten worker-subjects, statistically significant decreases in hand/wrist and shoulder muscle activity were found. A marginal, but significant increase in neck muscle activity was also found. When one subject …

A Comparison Of Anhydrous Ethanol Production From Ethylene And From Corn Utilizing Life Cycle Analysis Methodology, Gregory Morse

Theses

There is currently much concern with the impact on the environment due to industrial processes. One method to assess this impact is to perform a Life Cycle Analysis (LCA) on the process. Life Cycle Analysis is made up of three stages; Life Cycle Inventory Analysis, Life Cycle Impact Assessment, and Life Cycle Improvement Assessment. In this study, Life Cycle Inventory Analysis methodology was applied to two industrial processes for producing anhydrous ethanol. The first process is the fermentation of corn, and the second is the hydration of ethylene using water and a catalyst. Each process was first modeled using the …

Fundamentals Of Adhesion Of Organic Compounds And Aqueous Cleaning Of Glass And Metal Surfaces : Applications In The Pharmaceutical And Chemical Industries, Michel J. De Ruijter

Theses

In this thesis we studied the physics and chemistry of the adhesion of various classes of organic compounds to glass and stainless steel surfaces, by using diagnostic aqueous cleaning solutions and other techniques. We defined the thermodynamic requirements for aqueous cleaning based on extensive experimental and theoretical work. Novel cleaning diagrams are introduced, based on electrostatic interactions between organic compounds and solid surfaces, to facilitate the design of aqueous cleaning systems. We studied the mass transfer parameters for selected situations. The electrochemical Pourbaix-diagrams were used to explain the effect of hydrogen peroxide added to aqueous solutions and to avoid corrosion …

The Morphology Of Uhmwpe Wear Debris Generated By A Hip Joint Simulator, Aaron P. Essner

Theses

The size, quantity and shape of total hip replacement wear debris may identify wear mechanisms as well as play a role in osteolysis. Characterization of wear particles generated from a hip joint simulator was conducted followed by comparison with literature reported in vivo results. The effect of counterface material and lubricant type on particle morphology was assessed. Biomaterial pairs including UHMWPE articulated against CoCr, Alumina and Zirconia were considered. Deionized (D.I.) water and bovine serum were used as lubricants. Particles generated from Alumina/UHMWPE in serum were slightly larger than those for CoCr and Zirconia against UHMWPE in serum. Particle shape …

Reducing Rail-Truck Freight Intermodal Drayage Costs, David Moy Jr.

Theses

In rail-truck intermodal transport, a highway truck-trailer or container is moved by truck from a shipper to a rail terminal in the shipper's vicinity, and by rail in line haul between rail terminals. Upon being unloaded at the destination rail terminal, the container is delivered to a receiver (consignee) by truck. The highway portion of the move, or drayage, accounts for a relatively high percentage of total origin to destination cost, and it limits severely the competitiveness of intermodal service with door-to-door truck service. The approach used in this thesis is to examine in detail the current costs and potential …

A Study Of Transit Corridors Within The Njtpa Region, Mark Kagen Berger

Theses

Identifying potential bus and rail transit corridors for the North Jersey Transportation Planning Authority (NJTPA) region by examining current travel patterns of commuters was the purpose of this thesis. The current transit corridors within the NJTPA region was discussed first, followed by the methods for selecting specific municipalities for analysis. At this point, specific examinations of the selected municipalities' origin and destination travel patterns were mapped. The results were then summed up, along with a discussion of potential new bus and rail transit corridors based on trips originating along a corridor enroute to the same municipality. The final discussion examined …

Radiation Damage Studies In Gate Oxides, Sandeep G. Bharathi

Theses

Detailed investigation of the effects of Gamma-ray irradiation on the electrical properties such as current-voltage arid capacitance-voltage characteristics in thermally grown SiO₂ films in the thickness range of 15 to 120 nm on silicon substrates is presented in this thesis. The structures used in this study are Al/Poly/SiO₂/Si/Al and Al/SiO₂/Si/Al MOS capacitors. Based on the electrical characterization studies, we observe that irradiation causes generation of positive charges in the oxide leading to a shift of the high frequency Capacitance-Voltage (C-V) curves. An increase in surface state density at the SiO₂-Si interface with increase …

Modeling The Fate Of Volatile Organic Compounds In Wastewater Treatment Facilities; Implementation Of Volatilization Models In Envirocad, Vinita Chhahira

Theses

The 1990 Clean Air Act Amendments have identified wastewater treatment facilities as a major source of volatile organic compound (VOC) emissions. VOCs present in wastewater discharges affect the quality of receiving waters, while emissions to the air affect downwind populations. The primary mechanisms involved in VOC removal from a wastewater treatment facility are volatilization and stripping, biodegradation, and sorption to either suspended or biological solids. Although many models have been developed to predict the fate of VOCs in wastewater treatment facilities, no model completely predicts emissions for an entire wastewater treatment facility. The focus of this work is to incorporate …

A Modified Lrt-Based Spread-Spectrum Receiver Using Spatial And Temporal Processing, Jeffrey L. Cutcher

Theses

The problem of demodulating a direct-sequence (DS) spread-spectrum signal in the presence of single-tone or narrow-band interference and multi-path is discussed. A likelihood-ratio test (LRT) receiver is presented which consists of a whitening filter and a RAKE correlator.

A modified LRT receiver structure is then considered where the whitening filter is replaced by an antenna array with corresponding tap coefficients. The array spatially removes the interference by estimating it's angle-of-arrival. Using the array has an advantage over the original LRT receiver when a narrow-band interference is present. Both receivers are identical in performance under the single-tone interference model.

A third …

A Defect Detection Algorithm For Sequential And Parallel Computers, Ralf Hross

Theses

The comparison of images containing a single object of interest, where one of them contains a model object, is frequently used for defect detection/identification. This is often a problem of interest to industrial applications. To make this task more efficient, the implementation on parallel computers should be a major objective. This thesis introduces sequential and parallel versions of an algorithm that compares original(reference) and processed images in the time and frequency domains. The emphasis is on parallel implementation. This comparison may help to detect changes in images. Extracted data is also compared to database data in an attempt to pinpoint …

Hydrodynamic And Water Quality Modeling Of The Whippany River, John E. Krohn

Theses

The Whippany River is located in northern New Jersey and is a major tributary to the Passaic River System. This waterway accepts a wide variety of wastes from the diverse communities within its watershed. These wastes contribute to a rather complex network of biological, chemical and physical interactions.

The purpose of this study is to develop a water quality model using QUAL2E. This model will be used as a tool to simulate the complex interactions that take place within the river system. The river must he considered from physical, biological and chemical perspectives. A successful model can determine current water …

Effect Of Fiber-Matrix Coupling On The Mechanical Properties Of A Totally Bioabsorbable Composite, Barbaro Jesus Perez

Theses

The mechanical properties of a new class of bioabsorbable polymer-composite based on the amino acid tyrosine and calcium phosphate fibers were studied. The effect of the fiber aspect ratio on the elastic modulus of a discontinuous fiber composite was analyzed using the SMC composite micromechanics computer model. The mechanical stiffness of this polymer was found to be superior to that of poly-p-dioxanone, caprolactone and poly-o-ester.

The fiber surface was modified with methane plasma spray to improve the fiber-matrix coupling. The treated fiber composites had 16-40% higher tensile modulus than the untreated fiber composites. From the flexural test results it is …

Integration Of Pneumatic Fracturing And In Situ Vitrification In Coarse Grained Soils, Sean Thomas Mcgonigal

Theses

This thesis investigates conceptual integration of the Pneumatic Fracturing (PF) process with In Situ Vitrification (ISV) for remediation of contaminated soil. Integration will permit ISV melts to be initiated below the ground surface and extend the depth of the ISV process.

Bench scale experiments were conducted in 4.9 ft³ (0.14 m³) Plexiglas tanks filled with a test soil that was specifically blended to simulate the Hanford Formation in Richland, WA. Discrete pneumatic fractures were successfully created and filled with the ISV starter path material. Conductivity measurements made across two graphite electrodes exhibited a pre-fracture soil resistance of …

Analysis Of A Design For Its Quality Manufacturability In Terms Of Misalignments And Fastener Related Problems, Abhinav Dhar

Theses

This study analyzes the relationship between design parameters established at the initial stage of the design process and the manufacturing quality problems that manifest themselves during production. Specifically, we study the relationship between design features and the occurrence of misalignment defects and fastener related problems.

This outcome of this work is a methodology, Design for Quality Manufacturability (DFQM). DFQM addresses the likelihood that defects will occur during the manufacture of a product in a standard plant. This is based on the premise that defects in assembled products are often influenced by some features of the design and/or assembly process. These …

Application Of Signal Processing Techniques For Measurement Of Muscle Fiber Conduction Velocity, Satheesh Kumar Swaminathan

Theses

The objectives of this study were to evaluate if muscle fiber conduction velocity (MFCV) could be used as a reliable indicator of fatigue and to characterize the recovery of MFCV after a fatiguing contraction. The decline of MFCV with fatigue was modelled using linear regression and compared with the decline in median frequency (MF). It was found that the percent decline in MF with fatigue was greater than that of MFCV with fatigue and that the decline of MFCV was consistent in all subjects tested. It was thus determined that MFCV could be used as a reliable indicator of fatigue. …

Electrochcmical Reaction Of Redox Proteins Speeded Up By The Dye Modified Electrodes, Ting Chen, Shaojun Dong, Yuanwu Xie

Journal of Electrochemistry

The electron transfer reaction of redox proteins faciliated by dye medifiedelectrode was reviewed in this paper. The medification metheds and the properties of dye modifiedelectrode were discussed. Several different studying metheds,such as voltammetry, flow analysis and spectroelectrochemical method, were reviewed. Areversible electrocatalytic reaction mechanism was proposed and verified by comparing the digital calculation results with the experimental results.

Laser Scanning In-Situ Photoelectrochemical Microscopictechnique And Its Applications, Zugeng Lin, Jinkua You, Xiangdong Zhuo, Chun Zhang, Yong Yang

Journal of Electrochemistry

The main factors of the laser scanning in-situ photoelectrochemical microscopic measurement system which is set up in our lab have been discusaed in this paper. Some applications of this technique for in-situ study of modification and processing of semiconductor electrodes, monitoring of electro deposition process of semiconducting material and redox reaction occurring at metal oxide electrodes have also been presented. The results have shown that the technique is very powerful that for studing local photoelectrochemical properties of semiconductors and metal oxide electrodes. These provide important information on the micro structural and electronic properties in the solid/electrolyte interface.

Studies Of The Black Molybdate Conversion Film On Stainless Steel, Jingli Fang, Liuqin Liuqin, Keping Han, Yaohui Chen

Journal of Electrochemistry

A black conversion film was formed on stainless steel with cathodic electrode position method from a molybdate-phosphate solution. This film displayed good themcotability. The results of XPS and AES analysis showed that the thickness of the film was 820 nm and that Mo existed as Mo(Ⅵ) in the surface of the film, while existed as Mo(Ⅵ) and Mo(Ⅳ) in the internal layer of the film. The relative atomic percent content (A.C.% of the film obtained from the elemental composition constant region of the depth profile curves by AES was O 50.9%, Mo 29.4%, P 12.6% and Fe 7.1% respectively. The …

Studies On Low Temperature Performance Of Rechargeable Mh-Ni Batteries, Wenkuan Zhang, Jingxian Shi, Yuwan Lou, Qiusheng Duan

Journal of Electrochemistry

The Dependence of low temperature performance on the alloy composition and electrolyte component for rechargeable MH-Ni batteries is studied, the suitable composition of alloy and electrofyte are founds.