Engineering Commons^™

Automated Computer Drafting Of Precision Tooling For Drawing Operation, Basani Venkateswarlu

Theses

Based on customer requirements of components, design engineers create the necessary tooling using CAD to produce the exact part desired by the customer. A software package using CARL is developed to help the design engineer to create the drawings of Pinch off Punch and Pinch off for both rectangular/square and round punches. A variety of hole patterns for the punches are automatically created through the software, along with a possibility of selecting one of the standard patterns automatically for a drawing. The drawings are created such that the dimensions and the notes are automatically generated with the input of the …

Development Of Plasma Ion Nitriding Process Parameters To Increase Durability Of Machine Components, Wenge Yang

Theses

In this work glow discharge ion nitriding process was selected to increase durability of machine components. To achieve this goal, the process parameters were designed, established and optimized based on the desired surface properties. The orthogonal experiment method is used to optimize multifactors process parameters. Using the image analyzing approach the microstructure of differently treated materials were obtained and analyzed. Developed coating layers, including different nitrides such as Fe3N, Fe4N, and diffusion zone were controlled by the optimized process parameters. Analysis of the obtained microstructure and microhardness showed the improvement of surface mechanical properties. Performed wear testing experiments showed increased …

Determination Of Water-Cement Ratio In Cement Paste By Atomic Absorption Spectrometry, Jiong Zhao

Theses

As one of the important characteristics of concrete, water-cement ratio controls porosity and thus strength and corrosion resistance of hardened concrete.

This paper presents a laboratory observation for determination of water-cement ratio of fresh concrete for quality control and quality assurance. The atomic absorption spectrophotometer and the flouresence spectrophtometer were used to determine the calcium concentration in cement solution of various water-cement ratio. The level of water-cement ratio investigated ranged from 0.4 to 0.55 which covers the most range of water-cement ratios in present practice. The result of lab experiments shows an immediate relation between the water-cement ratio and the …

Bad Data Identification In Power Systems, Shichun Zou

Theses

Two classes of bad data (BD) identification methods in power system state estimation are studied.

The first class is the perturbation method. In this method, the obtained measurements are perturbed a few times. Each time a state is obtained from which measurement corrections are calculated. The statistics of the corrections corresponding to a BD are different from those corresponding to a healthy data. The method uses those differences for identification purposes.

The effectiveness of different indicators is studied. These include the normalized residual, the weighted residual, and residuals incorporating the statistics of the corrections.

The success rate of using the …

A Mouse-Driven Interface For Androx Ics-400, Chin-Tien Chen

Theses

A mouse-driven interface is extremely useful for software performing image processing tasks. This thesis describes an implementation of a mouse-driven interface for the Androx ICS-400 image processing board. The Androx board is housed in a Sun 4/330 running a UNIX-based operating system. The main goal of this interface is to provide a consistent and friendly user interface for image processing tasks and integrating the Sun window libraries with the Androx libraries. Various image processing tasks, such as gray scale and binary morphological operations, histogram, thresholding, filtering, spot, logical operations, arithmetic operations, zooming, scrolling, rank and image acquisition are implemented in …

Androx Implementation Of Nonlinear Filter, Keh-Chao Chu

Theses

Nonlinear filters, such as morphological operations, play an important role in image processing. Several software implementations of nonlinear filters are presented in this thesis. There may exist more than one method to implement a specific operation. The methods used in this thesis are chosen to be most suited for the machine used according to its structure. These most suited methods are also generally best for software implementations on other machines as well. The machine used here is the Androx image computing workstation.

Modification Of Wear Testing Methodology, Muhammed Farooq

Theses

In this work the existing computer controlled methodology has been modified A loading and unloading mechanism has been designed, manufactured and assembled. A specimen fixture has been designed and installed. Alloy steel specimens with different surface treatment were tested on the modified wear testing machine. Operational surface roughness was measured in all stages of running-in, steady state and catastrophic wear. The difference between technological and operational surface roughness was observed. The results show that the surface treatment by Plasma Ion-Nitriding with Magnetic treatment increases wear resistance. It was found that the coated material which had been magnetically treated with a …

Modeling Of Vacuum Microelectronic Lateral And Vertical Devices, Qiong Gui

Theses

Vertical and lateral configurations of the vacuum microelectronic device have been modeled using the simulation tools. Both cone and ridge cathode structures are used. Simulation results are compared with experimental data where available. These device structures include cathode, extraction grid, anode, and deflectors. The electric field at the tip of the cathode has been calculated for tip radius as small as 0.1nm. The model used takes into account the effect of potential on all electrodes on the E-field at the cathode tip. Also the effect of cathode geometry on the E-field is detailed.

Static characteristics are based on a new …

Influence Of Fly Ash Characteristics On Compressive Strength Of Mortar, Poorna Rajeswari Ratnaweera

Theses

Fly ash-cement mortar, constituting of fly ash, cement and sand, vary in strength characteristics from conventional cement sand mortar. Out of many parameters effecting the compressive strength characteristics of fly ash-cement mortar, four were investigated in this study. They are particle size and its distribution, weathering of fly ash, moisture content & water/cementitious ratio and mix proportioning.

Class F fly ashes from three different sources were used in this study. The particle size distribution and moisture content of fly ashes were investigated by standard ASTM methods. The unconfined compressive strength of mortar was obtained by testing 2"x2"x2" test cubes conforming …

Solidification/Stabilization Of Chromium Contaminated Soil Using Cement And Fly Ash, Arunkumar Sripathi

Theses

Chromium, when present in the soil, can cause serious health hazards. Toxicity depends upon the concentration in the soil. Chromium in soil has become a major problem in some sites and a method must be developed so that it can be treated or disposed of in a safe manner.

In this research experiments are conducted to check whether the chromium contaminated soil can be solidified and landfilled in a safe way. To have a control over the amount of chromium present in the soil, pure soil (free from chromium contamination) was used and chromium was added in different proportion.

Another …

Linear Regulator And Singular Control In Generalised State Space System, Devesh Kumar Thodimela

Theses

The problem of unconstrained optimal control of continuous-time singular systems is considered, by straight forward extension of some well-known equations derived for ordinary state-space systems by variational calculus and by the aid of the simplest algebraic and matrix tools: In this thesis, the interest is restricted to the case where the system is to be driven from a fixed initial state to a fixed final state as well as free final state tf while minimizing a performance index of the form

J = 1/2 ∫t_f t_o <( Y - Y_i), Q ( Y - Y_i) > d_t

Subject …

Tisi2/N+/P Silicon Junction Formation By Ion Implantation Through Metal Technique, Ying Wu

Theses

Experimental analysis, modeling and simulation of the formation and electrical characterization of TiSi₂/n⁺/p-Si shallow junctions are presented here. The formation of shallow n⁺-p junction, by ion implantation of As⁺ through Ti films evaporated on p-Si substrates followed by Rapid Thermal Annealing ( RTA ) and conventional furnace annealing has been performed in these experiments. Structural techniques such as Secondary Ion Mass Spectroscopy ( SIMS ) and Rutherford Backscattering spectroscopy ( RBS ) experiments have been employed to characterize the devices, and RUMP simulator was used to analyze and interpret the RBS data. Current-voltage …

A Parallelogram Four-Frame Model In 3-D Motion And Structure Recovery Using Unified Optical Flow Field Approach, Zhichun Lin

Theses

In this paper a new concept of the unified optical flow field (UOFF) for 3 D motion analysis from a stereo image sequence is implemented which is an extension of the temporal optical flow formulations developed by Horn and Schunck. A four frame model is established and a spatial optical flow is also introduced.

In order to alleviate the problem of the strict requirement of two identical sensors in common stereo imagery a new imaging system is presented in this paper that needs only one camera, two plane mirrors and two switches to generate a phase shifted binocular sequence of …

Size Reduction Of Polymeric Particulates By Jet Milling, Cheng Hua

Theses

A basic theory for the size reduction operation by jet milling has been developed.

Typical samples of feedstock have been analyzed using screen analysis to determine the initial distribution of polymeric particulate sizes prior to jet milling.

A statistical theory .was developed using probabilities to represent the likelihood that specific size reductions would occur. These probabilities include the effects of various equipment.

The theory was then used to predict the distribution of polymeric particulate sizes after jet milling. The agreement between the predictions and actual results was within 5 %.

Encouraged by the successful work of the simulation of the …

Eeg Data Compression, Yun-Chu Wu

Theses

This paper presents two different ways to compress EEC data-direct data com pression and a data transformation technique. The Adaptive Delta modulation and Huffman coding are used in the former method to predict or interpolate the data. Linear orthognal transformation algorithms are used in the latter method to detect and reduce the redundancies of the data by analyzing the spectral and energy distribution. Each method is implemented by programming the computer. The experimental results of their efficiencies and errors with different requirements and under different situations are compared and discussed. By comparing the EEC data compression degree and normalized square …

Catalytic Oxidation Of Chlorinated Compounds Over Pdo/Al2o3 On A Monolith, Tai-Chiang Yu

Theses

The catalytic oxidation of trichloroethylene(TCE) and dichloromethane (DCM) was investigated over a catalyst containing 4% PdO on Al₂O₃ washcoat and on a cordierite monolith with 400 channels per in². Reactivity and selectivity of the catalyst for the destruction of 200 ppm C₂HCl₃ and 500 ppm CH₂Cl₂ in air was evaluated over the temperature range 250 to 550 °C. This research was conducted in a tubular reactor system at space velocities of 4,000 to 24,000 v/v/hr. It was found that complete oxidation occurs at 500°C for DCM and 550°C for …

A Combined Gel Entrapped And Membrane Attached Microbial Process For Biodegrading Organic Compounds, Fayaz Saifuddin Lakhwala

Dissertations

A comparative study has been performed between two bioreactors treating phenol, one using calcium alginate entrapped microorganisms, and the other using microorganisms attached on the surface of a polymeric membrane. Laboratory experiments conducted in batch recirculation mode, as well as a continuous feed mode, showed that the calcium alginate bio-bead reactor is more efficient in treating high feed concentrations of phenol, while the membrane bioreactor is more effective in the lower concentration regime (less than 150 ppm). In batch recirculation mode, the reaction rates (expressed as mg phenol/hr*gm dry cells) in the membrane reactor are an order of magnitude higher …

Thermodynamics Of Strong Electrolyte Solutions : Prediction Of Osmotic Coefficients By Pair Correlation Function Method, One Kwon Rim

Dissertations

Thermodynamic properties (osmotic coefficients) of strong electrolyte solutions have been studied by the method of statistical mechanics. First the charged soft sphere potential is developed based on the Pauling type model. Next the charged soft sphere potential is converted to the thermodynamically corresponding charged hard sphere potential by way of the perturbation method developed by Verlet and Weis. Simultaneously, the radial distribution function is developed by modification of the Exponential theory through introduction of the Stillinger-Lovett moment condition. The effective hard sphere diameter values calculated by the perturbation method are combined with the modified Exponential theory, and these quantities are …

On Local Stresses And Spring Constants Of A Sphere-Nozzle Connection, Ban-Li Lyow

Dissertations

This dissertation studies the local stresses and spring constants of a spherical shell with a nozzle attachment when it is under various loadings, namely radial force, overturning moment, horizontal shear force, and torsional moment. Because of the mathematical difficulty in modeling the nozzle-sphere configuration, particularly with nozzle opening, the finite element method (ANSYS package) is utilized in this study. The model used in this study is a quadrilateral thin shell element model when the γ_s (spherical radius/thickness) value is larger than 10. Otherwise the isoparametric solid element is used. The resulting stresses are basically biaxial state of stresses. It …

N-Cross Coupled Phase Locked Loops, Joseph C. Aboukhalil

Theses

Interference cancelation has been mainly performed using arrays, in an important issue in communication both array and spatial cancelation and time domain approach were used. In array applications, depth of cancelation may dependent on the interferences to background power ratio and their spatial distributions. Also, array cancelers are inadequate when the signals are less than an array beamwidth apart. The latter was dealt with using supperesolution and eigenanalysis methods. Different time domain methods were used in the past. Among them what is termed Cross-Coupled PEL. It is an arrangement of two PLL each one is locked on and tracking one …

A Study Of Biological Dentrification Of Munition Wastes, Sonia R. Venugopal

Theses

Kinetics of denitrification were studied using a consortium from the Lawrence, Kansas municipal treatment plant. Experiments were conducted in the batch mode, under controlled oxygen and pH conditions. It was found that the Monod model can successfully perdict the experimental results of nitrate depletion. It was also found that when the pH is maintained at values between 7.0 and 8.5, nitrate can be treated in a batch mode without having any significant nitrite presence in the reactor. The experimentally determined kinetic parameters were used in preliminary calculations for sizing a sequencing batch reactor (SBR). An existing mathematical model for the …

Fault Tolerant Clos Network, Preet Mohan S. Ahluwalia

Theses

Multistage interconnection networks, or MINs, provide paths between functional modules in multiprocessor systems. The MINs are usually segmented into several stages. Each stage connects inputs to appropriate links of the next stage so that the cumulative effect of all the stages satisfies input-output connection requirements.

This thesis deals with a fault tolerant Clos network. The fault tolerance technique involves addition of extra switches per stage to compensate for any switch failure The reliability analysis of both ordinary and fault tolerant Clos networks is presented. The optimal number of extra switches required to get the best reliability results has been analyzed.

Development Of Techniques Of Artificial Intelligence In Identifying The Different Machined Surfaces, Yi-Ching Chou

Theses

This thesis deals with the identification of different machined surfaces with artificial inteligence techniques. There are five kinds of machining operations: grinding, turning, milling, EDM and waterjet which determine the characteristics of resulting surfaces. Topology of various specimens is measured using the surfanylizer. Twenty one parameters are extracted from the measurements to describe the characteristics. In this thesis, we develop neural and expert systems that recoginize and classify surfaces according to the machining methods.

Ct Fan Beam Reconstruction With A Non-Stationary Axis-Of-Rotation, Joseph A. Concepcion

Theses

One important aspect for reconstructing an image using Computed Tomography (CT) is that the axis-of-rotation must pivot at the same point on the reconstruction plane as the x-ray source and CT scanner assembly rotates around the imaged object. This pivot point is used as a reference point for backprojecting pixel values to their proper coordinates. Therefore, reconstructing an image with a non-stationary axis-of-rotation would backproject pixel values to wrong coordinate points, since the reference point is non-stationary for every projection angle.

A convolution filtered backprojection algorithm has been derived for correcting images that were acquired with a non-stationary axis-of-rotation using …

Tri-Color Led Display System Using Microcontroller, Costakis A. Constantinou

Theses

A seven-by-forty-eight tricolor LED display panel is designed and built around the 68HC11 MCU.

Four bilateral switching transistors (4066) are used in a Wien bridge configuration to drive each tri-color LED. With this circuitry one is able to drive the tricolor LED symmetrically. An alternative design that uses only two switching transistors is also offered.

A software program was developed to output on the display scrolling and fixed messages. Each message could be displayed in a different color (Red, Green and Yellow) and at a different speed (Slow, Fast, and Medium). The program also includes an editor with insertion and …

Comparative Study Of Prediction Gain Based On Neural Network Architecture, Prashant M. Shah

Theses

This thesis describes the Neural Network approach to design predictor using Delta and Generalized Delta Rule. The predictor is designed by supervised training based on the typical sequence of pixel values. Neural Network is used to find the coefficients of the predictor. Both 1-D and 2-D scheme of the pixels as well as linear and non-linear correlations are used to find the coefficients by training. Different combinations of pixels are used to find the "best" combination among the order of the predictor.

Novel Way Of Sub-Carrier Coherent Detection And Clock Recovery In Fiber-Optic Communications, Narayan Gehlot

Theses

We experimentally demonstrate a novel concept for recovery of a Sub-Carrier and Timing Clock in fiber-optic communication systems using a Wavelength Division Multiplexing technique. The idea is to send a low radio frequency (RF) as a reference pilot from the transmitter to the receiver on a separate laser using the principle of Wavelength Division Multiplexing (WDM). This low frequency signal is taken to be a subharmonic of the subcarrier used to carry information and intensity modulate another laser. Such approach will be expected to generate at the receiver a local oscillator in high coherence with the subcarrier.

We show that …

Information Handling System With A Personal Computer To Assist In The Manufacturing Of Plastic Parts, Yi Chung

Theses

The ongoing personal computer development has led to its increasing application in manufacturing to improve productivity. Being more aware of this technology, most of these benefits have accrued to large firms. The intent of this thesis is to show that it is equally advantageous for small manufacturing companies to utilize them and show how they can do so.

The field of production control systems is discussed and those areas where personal computers can be applied are emphasized. Forecasting, warehouse management, material requirement planning, and inventory control are the most appropriate. An application example using dBase III plus to write the …

Solid-Liquid Suspension In Agitated Vessels Provided With Multiple Impellers, Tong Li

Theses

A large number of references can be found in the literature on the effect of mixing parameters on the achievement of the minimum agitation speed to just suspend solid particles. In the vast majority of these studies the agitation system consisted of just one centrally mounted impeller. However, the determination of the minimum agitation speed to achieve the just suspended state when the additional impellers are used have received very little attention. It is the intent of this work to investigate the role of multiple impeller agitation system on the achievement of the complete particle suspension state. The effect of …

Coexistence Of Three Pure And Simple Competitors In Four Interconnected Bioreactors, Ming Wu

Theses

It is known that a homogeneous environment having invariant inputs cannot allow for steady state coexistence of any number of pure and simple competitors. However, it has been proven that two pure and simple competitors can coexist at a steady state in two interconnected chemostats, if the conditions are such that they allow a different species to grow faster in each one of the two vessels. It has been also shown that three pure and simple competitors cannot coexist in three interconnected chemostats, even if the conditions are such that a different population could grow faster (have the competitive advantage) …