Engineering Commons^™

Axisymmetric Air Jet Impinging On A Hemispherical Convex Plate, Salahuddin Qureshi

Theses

This experimental study was carried out on an axisymmetric air jet impinging normally on a smooth, hemispherical convex plate. Three different nozzles of diameters 0.5in.(12.7mm), 0.375in.(9.525mm) and 0.25in.(6.35mm) were used and the nozzle exit Reynolds number varied from 14,000 to 80000.

The impingement hemispherical plate was made of brass and had a nominal outer diameter of 7.48in (189.99mm).

Calibrated Pitot tubes, U-tube manometer and a micromanometer were used for pressure and velocity measurements. The Pitot tubes were mounted on Precision position mechanisms permitting the accurate traversing in any direction in space. The test air flow rate was measured with calibrated …

Magnitude And Frequency Of Floods : A Comparison Of Regional Methods In The United States, Frank A. Rogalla

Theses

To allow the safe and economical design of structures in flood plains of natural streams, techniques to estimate the magnitude and frequency of floods are established through multiple regression analysis for each state, relating flood peaks to topographic and climatic characteristics of the drainage basins. This study describes and compares the regional equations to assess peak flows for 2, 5, 10, 25, 50 and 100-year recurrence intervals in different states of the U.S.A.

Publications from 40 continental states were reviewed and the regression equations analyzed on similarities and accuracy. Tables compare parameters, their frequency of occurence, and the constants and …

Development Of New Products Involving Various Uncertainties For Success, Manuel J. Senra

Theses

The development of new products is a very important task for any company, since the survival of most of the companies depends on their ability to introduce new products on the market. This is not, by all means, an easy task; it is seen from the large number of unsuccessful new products reported.

It is been proved that out of every ten products which emerge from Research and Development(R & D), only two become successes. For reasons like the one mentioned and because larger and larger funds are allocated to R & D, it is a very important task to …

Application Of The Self-Assessment Technique To Improve The Productivity Of The Project Engineering Function : A Case Study, Roman Stetkiewych

Theses

While traditional industrial engineering methods can be successfully applied to improve productivity in the operations area, their effectiveness is limited where knowledge type work is being performed. For these types of activities, self-assessment has been proposed as a methodology to achieve increased efficiency. This thesis presents the results of applying this concept to the engineering function of a manufacturing firm.

Using a directed set of questionnaires as a focus, a self-assessment of itself was conducted by the Project Engineering Department to consider how well it thought itself to be performing and what its deficiencies were. Co-jointly the departments whose work …

Automated Arrhythmia Detection In The Exercise Electrocardiogram, Gregory Ciurpita

Theses

A self-adapting, non-real time method for detecting arrhythmias in single channel Exercise ECG is described. Linear and non-linear digital filtering techniques are used to remove additive noise. A time-varying threshold technique is used to detect R-waves based on amplitude. Feature extraction and matched filter methods are used to classify QRS-waves into existing types, or to create new types. The program works on digitized data from floppy disk and plots all data along with classification results on ReGis graphics terminal or printer. This work will continue so that the system will be capable of processing three-channel ECG in real-time.

Digital Fm-Demodulation Using Digital Signal Processing Techniques, Peter Wagner

Theses

This thesis presents the results of research in the area of digital demodulation of FM signals. The first part of the thesis describes the performance of digital Hilbert-transformers and Differentiators that are optimized in a determined bandwidth. These digital filters are used to build a digital Klapper-Kratt detector. According to this procedure, the coefficients of the digital Klapper-Kratt detectors up to the filter length N=25 are calculated and the resulting discriminator ripple computed and evaluated. One suggested algorithm gives the opportunity to balance the detector at a certain center-frequency. The major part of this thesis describes a new approach towards …

The Catabolism Of Arginine By Lactobacillus Brevis In A Chemostat, Jeanette Carque

Theses

A total of thirty chemostat runs were evaluated for steady state biomass concentration of L. brevis and arginine deiminase activity at dilution rates ranging from 0.022 to 0.1.07 h^-1 for a substrate feed consisting of 1.0% glucose and 0.5% arginine (w/v). Biomass concentration and enzyme activity responses were also evaluated for variations in glucose concentration from 0.05% to 1.5% and variations in arginine concentrations from 0.25% to 1.0% at a constant dilution rate (0.06 h^-1).

The system exhibited multiple steady states for the range of dilution rates from 0.022 to 0.107 h^-1. A steady state …

Preparation And Properties Of Novel Dental Adhesives Based Upon Pentaerythritol, Yuan-Yuan Su

Theses

Urethane methacrylates were synthesized from Pentaerythritol, TDI, HEMA and four phenolic blocking agents or from hydroxypropyl methacrylatel TDI and two phenolic blocking agents. All the products were characterized by melting pointy infrared spectroscopy, NMR spectra, and elemental analysis. The bonding of these materials to dentin slices was also investigated. Such materials are supposed to not only react with the organic constituent of dentin but also polymerized with restorative resin. It was found that bond strength was enhanced by the use of the urethane methacrylates, resulting in best mean bonding strengths of 2400 psi.

Preparation And Testing Of Blocked Isocyanate Dental Adhesives, George W. Sweitzer

Theses

Three monomers were used in this study. Two were prepared from 2,4-toluene diisocyanate (TDI),2 hydroxyethyl methacrylate (HEMA), and either o-methoxyphenol, or o-chlorophenol. The third monomer was prepared from pentaerythritol, TDI, HEMA, and p-cresol.

These monomers were bonded to dentin slices, and then combined with an adhesive copolymer consisting of methyl methacrylate and poly(methyl methacrylate). This mixture was polymerized at room temperature by addition of N,N-dimethyl-p-toluidine, and benzoyl peroxide. This adhesive copolymer was applied to monomer coated slices of dentin, and to aluminum coupons already fixed in a jig. The monomer-coated dentin slices (treated with the adhesive copolymer) were then placed …

Digitally Implemented Klapper-Kratt Fm Detector Using The Intel-292o Digital Signal Processor, Chang-Hwan Park

Theses

This thesis describes and analyses a digitally implemented FM detector, which is a new member of the family of FM detectors introduced by Drs. Klapper and Kratt.

The properties of the new detector are low delay, excellent sensitivity, extreme linearity, and compatibility of components with integrated circuit technology.

A working model is implemented by adapting FIR digital s signal processing methods, and is realized using the Single-Chip Digital Signal Processor Intel-2920 which is comprised of micro-processor, scratch-pad data RAMs, program store EPROMs, A/D and D/A conversion circuitry, and I/O circuitry.

The performance of the working model shows very good linearity …

An Analysis Of The Heating And Densification Process During Rotational Molding Of A Thermoplastic Powder In A Uniaxially Rotating Cylindrical Cavity, Floyd Steven Ribe

Dissertations

This dissertation presents the results of an experimental and theoretical investigation of the heating and densification portion of the rotational molding process in a uniaxial, cylindrical mold.

A thorough literature survey is included which reviewed past analysis of the rotational molding process and other areas that assisted in understanding of the process.

The results presented in this dissertation included an analysis of the densification process by use of Scanning Electronic Microscope (SEM) photography producing intermediate correlations between the physical properties of the densifying material and neck radius of adjacent coalescing spheres. In addition, a hybrid experimental procedure coupled with a …

Conversion And Kinetics In The Reaction Of Chloroform With Water Vapor At High Temperatures, Chii-Guang Hwang

Theses

This is an experimental study on thermolytic reactions of chloroform with excess water vapor where kinetic parameters are determined and complete product analysis made at atmospheric pressure over a temperature range from 550to 1050°C. In this study, water vapor was introduced as a reactant to convert chlorine in chlorocarbons to stable HCl which is an easily neutralized end-product and thereby completely destroy chloroform. Substantial amounts of thermodynamically stable species: HCl, CO, CO₂, C(s) etc. were observed as products.

The reaction was studied in a 46cm tubular flow reactor mounted in a furnace that had three independently temperature-controlled heating …

Reactions Of Hydrogen With Chloroform And Trichloroethylene At High Temperatures, Burhan Mahmood

Theses

The reactions of chloroform and trichloroethylene with hydrogen in the temperature range 550 to 1000°C were studied using tubular flow reactors of varying diameters. The residence time range was from 0.05 to 3.0 seconds.Two different concentrations of the chlorinated species were used, each with hydrogen in large excess. Flat temperature profiles (+/- 5°C) were achieved over 80 to 85 per cent of the 45 cm long reaction zone, with inlet gases preheated to about 400°C.

No chlorinated hydrocarbons, products or reactants were observed at /above 850°C. The major products at these temperatures were C₂H₂, C_{2 …}

Failure Rates And Leakage Current Increase In Tantalum Capacitors Of Different Manufacturers, Joseph G. Grant

Theses

This study has determined the effect of high humidity and temperature on solid tantalum capacitors, from five different sources.

The reasons for using capacitors from five different prestigious sources is to first determine how the parameters change with the different manufacturing techniques used by the different sources. Secondly to rank the different sources according to reliability. The parameters that were measured before and after the "1000 hour" high temperature and humidity test were, capacitance, leakage current, and equivalent series resistance. All the capacitors showed significant increase in leakage current after the test, but there were wide variations in catastrophic failure …

A Comparison Of Training Available To Entry Level Naval And Merchant Marine Engineroom Personnel, Paul J. Bugelski

Theses

Similarities between occupations or industrial environments are often overshadowed by differences between goals, services, or products. From the time that shipboard steam propulsion became a practicality the Naval and merchant marine services have experienced this phenomena. For various reasons, the two sectors have ignored similarities between their respective occupational sub-groups, e.g. engineroom crews, and the training which facilitates each group's performance.

Manning and training problems, related to the evolution of automated shipboard propulsion plants, have been shared by the U.S. Navy and commercial ship operators. Recent events such as the British Falkland Islands crisis and the implementation of the U.S. …

A Cogeneration Industrial Park In An Urban Environment In The Year 2000, Raymond T. Scott

Theses

An investigation into the feasibilty of placing an industrial park in an urban environment in the year 2000 was made. A selected cogeneration facility located within the park would supply electricity and process steam to the industries with minimal transmission costs and environmental effects. A projection was made on the industries that would exhibit growth to the end of this century, and yet be environmentally benign in nature. These industries would be placed within the industrial park. The selection of the cogeneration facility was based upon projections of fuel availability, environmental factors and available technologies. Socio-economic factors and the effects …

A Maintenance Program Guide For The Non-Technical Building Manager, Luis M. Tavares

Theses

For the most part, the title of Building Manager is conferred upon an individual who is given the responsibility of services support for a facility. However, this title many times is carried by men/women who are responsible not only for the upkeep of the general building, janitorial, and food services but also for the safekeeping of the building equipment, such as mechanical and electrical machinery. At times, these individuals may be involved with general service responsibilities and tend to lose sight of maintenance needs.

In order for the Building Manager to implement maintenance successfully, he/she must understand the close cooperative …

Comparative Study Of Computational Methods For Kinematics Of Mechanism Analysis, Ren-Jea Wang

Theses

This thesis introduces three numerical methods of solving nonlinear algebraic equations, i.e. Newton's method, Brown's method, and Brent's method, and applies these methods to kinematics of mechanism problems for comparative study.

Firstly, each method is reviewed in some detail. Then experimental computer programs, NABKAP(Nonlinear Algebraic equations Based Kinematic Analysis Programs), are developed based on the above methods and used to solve kinematic of mechanism problems. Example problems include various kinds of four-bar mechanisms and two degree of freedom mechanism. Lastly, each technique is compared with the others based on the above computational experiences.

The FORTRAN programs used for this study …

A Global Resource Allocation Model For An Electrical Utility, Pantelis G. Tinios

Theses

The management of the electric utility company, as the management of any other company, has to make important decisions which will have a direct impact on the company's future operations.

In this study, a global model was devised which enables the management to make more intelligent decisions related to the company's planning process.

The company's goals and subgoals are formulated, in a systematic way, into the mathematical model along with operational and financial constraints. Productivity growth, steady labor force, fuel availability, cash flow requirements, share rating, and coverage were some of the goals to be achieved. The goal programming technique …

Simulation Of The Manufacturing System : A General Discussion, Di-Cheing Chien

Theses

This thesis treats the problem of multi-variable sensitivity analysis in a production system which may be used in investigating a variety of characteristics of a flow production system which involve idle time, cost, production rate, ect. are the subjects of the analysis.

The analysis procedure follows the rule of INPUT/OUTPUT through a production process. A simple system model using elements such as : raw material, transfer tool, labor, machine and energy/ or electrical power, is used to lead into the construction of dependent-variable system. A utilization is made of industrial robots as well as humans in loading and unloading machines …

On Circular Hvac Duct Design Through Stress Analysis, Chien-Chung Lee

Theses

In this thesis, comprehensive studies through stress analysis of the circular HVAC ducts are made. The ducts are made of thin gaged steel sheet, and reinforced by stiffeners that are made of hot-rolled steel sections of L or C shapes. The ducts are loaded with pressure, its own weight and the possible seismic accelerations. A comprehensive FORTRAN program is developed as an aid Lo achieving the optimum design of circular ducts, i.e. duct thickness, stiffener spacing, stiffener size and seismic span length, Several stress analysis tables and a design parameter plot arc, provided in this thesis Lo facilitate design optimization.

A Diagnostic Study Of Burning Black Powder Via Stroboscopic Laser Schlieren Photography, Donald Bruce Rowland

Theses

The combustion processes and products of a single grain of burning black powder were experimentally investigated via the stroboscopic laser schlieren photographic technique. A high power modulated argon laser system was used in conjunction with a streak camera to provide a dynamic sequence of time resolved, high resolution schlieren photographs of a burning black powder grain. When black powder burns, a multi-phase product is produced consisting of hot gases, solid particles, and a molten liquid spray. The expansion processes of this multi-phase product cloud were recorded and characterized. Molten drops, reactive and nonreactive particles within as well as outside of …

Keeping Up With Technological Change, Karlis V. Kopans

Theses

Advances in technology over the past fifty (50) years have changed virtually everything that touches our lives today to some degree. However, in the last five years or so, these innovations have been combined into products and systems which have visibly begun to change society as we have known it in the past.

Only in recent years, have the affects of technological change or innovation on society begun to be examined. While a fair amount of literature has been published to date on specific areas of technological change, few publications have been produced which provide a general overview of the …

A Comparison Of The Biodegradation Of Phenol And O-Chlorophenol Using A Municipal Mixed Liquor And Three Commercial Microbial Preparations, Nigel P. Mcmullen

Theses

The biodegradation of phenol and O-chlorophenol was studied in six-liter batch reactors, using a municipal mixed liquor (from the Livingston, NJ treatment plant) that had not previously been exposed to either of the substrates. In addition, three commercial microbial preparations: BI-CHEM (Sybron), Hydrobac (Polybac), and LLMO (General Environmental Science), were tested alone and in combination with the municipal mixed liquor.

It was found that the municipal mixed liquor performed significantly better than any of the commercial preparations by themselves. When the commercial preparations were mixed with the municipal mixed liquor in a ratio of 1:10 it was found that the …

Mode Of Communication And The "Risky Shift" : A Controlled Experiment With Computerized Conferencing And Anonymity In A Large Corporation, Computerized Conferencing & Communications Center, Starr Roxanne Hiltz, Murray Turoff, Kenneth Johnson

Computerized Conferencing and Communications Center Reports

Peer groups of five managers in a large company with a well developed corporate culture engaged in choice dilemma tasks using three modes of communication: face-to-face, synchronous computerized conferences with regular names, and synchronous computerized conferences with assigned pen names. This is the final technical report on the experiment, including documentation of all procedures, and reports of the tests of all hypotheses, including those which were not supported.

Choice behavior varied by problem and mode of communication. On a problem related to a major decision on the future of the company, conservative choices and conservative shifts dominated. On two choice …

Development Of Dynamic Testing Machine For Laboratory Modeling Of The Rock Fracturing Phenomenon, Mohammad Ali Moghaddass Zadeh Kermani

Theses

The purpose of this thesis is to develop a dynamic testing machine for laboratory modeling of the rock fracturing phenomenon. Bearing stratum fracturing is a construction difficulty which occurs when end-bearing piles are driven to weak rock or weathered sound rock. It is a pile group effect and can result in significantly less pile carrying capacity than the final driving resistance would normally indicate.

A linear scaling factor was derived to establish similitude between the laboratory apparatus and field conditions. This scaling factor is approximate and was used for overall sizing of the apparatus and its components. A more exact …

Mathematical Simulation Of Proteins Separation In A Packed Bed, Jing James Huang

Dissertations

The generalized adsorption models are developed to simulate the unsteady state mass transfer behavior in a packed column. Based on the nature of adsorbent particles, the adsorption models may be classified into two categories: (1) the surface adsorption model, (2) the pore diffusion model. In the first model, it is assumed that the internal diffusion is negligible, and the adsorption rate is determined by external diffusion and surface adsorption. In the second model, the effect of internal diffusion is considered as significant as that of external diffusion. For both models, the effect of axial dispersion in fluid phase is emphasized. …

Mathematical Modeling Of Carrier Mediated Mass Transfer Through Liquid Membrane Systems, Keng Chao Wang

Dissertations

Dispersed liquid membrane systems are double emulsion drops. Two immiscible phases are separated by a third phase which is immiscible with the other two phases. The liquid membrane systems were classified into three types: (1) carrier mediated mass transfer, (2) mass transfer with reaction in the receiving phase, (3) mass transfer without any reaction involved. Copper extraction, phenol removal and solvent extraction were used as typical examples for each type of the membrane systems in the derivation of their mathematical models. Models with or without the consideration of film resistances were developed and compared. The models developed in this study …

Stress In The Alveolar Bone Surrounding A Dental Implant, Jagmohan Singh Kohli

Theses

The purpose of this study is to find the stresses developed in mandibular bone due to the occlusal loading of oral endosseous blade implants. Previous work done in this area was based on the theory of "Beam on Elastic Foundation". As the width/length ratio employed is approximately 0.65, the theory of "Plate on Elastic Foundation" used in this thesis is more appropriate. The mandibular bone acts as the foundation supporting the endosseous implants.

The analysis is complicated by the fact that the implants are irregular plates of varying thickness, the foundation modulus is a variable and the occlusal loading is …

An Experimental Investigation Of The Kinetics And Thermal Properties Of Poly(Ethylene) Terephthalate And Its Related Di-Acid Modified Copolymers, Satish Baliga

Theses

Poly(ethylene) Terephthalate , PET, is synthesized from purified Bis-hydroxyethyl Terephthalate,(BHET), in the presence of antimony oxide catalyst. Rate constant for the polycondensation reaction, based on a second order kinetic model is found to be 152.4/mol/hr.

A new modified polyester Polyethylene Adipic Terephthalate (PEAT) is synthesized from BHET and adipic acid. The effect of adipic acid content in the copolymer,on the rate of polycondensation is studied. Adipic acid is shown to improve the activity of the polymer chain ends thereby increasing the apparent reaction rate constants.

The modified polyesters are observed to melt at a lower temperature than PET. Moreover, the …