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Masters Theses

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Articles 1501 - 1530 of 2634

Full-Text Articles in Physical Sciences and Mathematics

Laboratory Studies Of Filter Pack Grain-Size Distributions And Hydrophobic Treatments To Enhance The Recovery Of Free-Phase Floating Hydrocarbons, Hugh Garret Heuvelhorst Jun 1993

Laboratory Studies Of Filter Pack Grain-Size Distributions And Hydrophobic Treatments To Enhance The Recovery Of Free-Phase Floating Hydrocarbons, Hugh Garret Heuvelhorst

Masters Theses

Experiments were conducted in laboratory sand tanks to evaluate filter pack design criteria in an effort to improve free-product hydrocarbon recovery from sand aquifers. Filter sands were prepared and installed in the test tanks to examine the relative efficiency of two different grain sizes and two different grain-size distributions to imbibe kerosene from the formation sand and release it to their respective wells. Treatments of different chemical products were applied to other filter sands to create a hydrophobic coating on the grains. The hydrophobic coatings were tested on filter sands of different grain sizes and grain-size distributions and compared to …


A Fracture Analysis Of Glacial Tills In Southwest Michigan, Ralph L. Freed Jun 1993

A Fracture Analysis Of Glacial Tills In Southwest Michigan, Ralph L. Freed

Masters Theses

Fractures were recorded and measured at seven southwest Michigan glacial till locations to identify geometry and spacing. Strong preferred orientations were shown at azimuths of 110° and 140° for two sites, and at azimuths of 85°, 110°, and 135°, and at 44° and 167° for two sites. Several sites had numerous oblique fractures.

Thirty-eight azimuthal Wenner arrays and four Schlumberger surveys show apparent resistivities vary widely with depth of penetration and material composition. Eleven percent of azimuthal surveys show an elliptical data array coinciding with preferred orientation of an adjacent fracture set. The relationship between azimuthal survey and fractures is …


The Effects Of Composting Of Yard Wastes On The Ground-Water Quality: Wmu Farms Site, Kalamazoo, Michigan, Bryan Kirk Allen Jun 1993

The Effects Of Composting Of Yard Wastes On The Ground-Water Quality: Wmu Farms Site, Kalamazoo, Michigan, Bryan Kirk Allen

Masters Theses

In the rush to find alternatives to landfilling of yard waste, federal and state agencies have identified composting as the main solution. There is therefore a need to address the possible environmental problems which could be associated with such composting operations. Compost may contain nutrients, organic acids, pesticides, and metals which could leach through soils to the ground water posing a potential contamination problem.

At the WMU Farms Site, two sites have been used for the composting of leaves by the City of Kalamazoo. The physical and chemical hydrogeology of these sites were characterized.

The results suggest that the presence …


Signal Processing With Neural Networks, Pero Smrzlic Jun 1993

Signal Processing With Neural Networks, Pero Smrzlic

Masters Theses

In this study, we introduce the Adaptive Back Propagation (ABP) learning algorithm, computationally superior to the standard Back Propagation. The ABP is based on the new activation function, with its corresponding adaptive learning parameter. By using the combination of computer simulations and analysis in the domain of activation function, the Method of One Hidden layer was developed for the effective utilization of units in one-hidden layer networks. A parallel version of the ABP was designed and implemented on a nCUBE-2 supercomputer with 128 processors.

The simulation results suggested a strong correlation between frequency of signals and the role of hidden …


Enhanced Retroreflection Of Light From Rough Metal Surfaces, Sivakumar Natarajan Jun 1993

Enhanced Retroreflection Of Light From Rough Metal Surfaces, Sivakumar Natarajan

Masters Theses

The optical constants n and k measured by Johnson and Christy (1972) for the noble metals (gold, silver and copper) are used to analyze the relationship between the surface characteristics and the peak height and half-width of the backscattering peak which is observed in the angular distribution of the intensity of diffusely reflected light at a vacuum-metal interface in a direction antiparallel to the original incident beam. Surfaces with surface roughness of heights less than 200 A to 300 A will be considered and a recently developed perturbation treatment will be used in these studies.

The backscattering of light from …


On Clock Routing Techniques For Vlsi Synchronous Systems, Wasim A. Khan Jun 1993

On Clock Routing Techniques For Vlsi Synchronous Systems, Wasim A. Khan

Masters Theses

The clock signal is vital in maintaining proper dataflow, and thus the total throughput, of a high performance synchronous system.

In this thesis, we develop a clock distribution scheme for high performance systems which maximizes the operating clock frequency. We develop an algorithm which routes a planar clock tree with zero skew, minimum source to sink pathlength, and minimal total wirelength. The algorithm also provides a smooth tradeoff between maximum source to sink pathlength and total wirelength while keeping the clock skew at zero.

In many microprocessor designs, multi-phase clocks are used for improved system design. Routing a multiple clock …


Middle Terminal Cell Models For Efficient Over-The-Cell Routing, Siddharth Bhingarde Apr 1993

Middle Terminal Cell Models For Efficient Over-The-Cell Routing, Siddharth Bhingarde

Masters Theses

In this thesis, we introduce a new class of cell models called Middle Terminal Models (MTM) which combines the advantages of existing cell models: BTM and CTM. This class contains the models 2MTM, 3MTM-V, and 3MTM+V depending on the number of metal layers and the permissibility of vias in over-the-cell areas. In MTM, two rows of terminals are located in the middle of the cell. This partitions over-the-cell area into three regions and allows allocation of more nets to over-the-cell area in congested channels. We prove that when vias are allowed over-the-cell, in "almost all" cases the MTM based layouts …


Non-Resonant Transfer And Excitation For S^13+ Projectiles Colliding With Neutral Gas Targets, Liang Duo Apr 1993

Non-Resonant Transfer And Excitation For S^13+ Projectiles Colliding With Neutral Gas Targets, Liang Duo

Masters Theses

Non-resonant Transfer and Excitation (NTE) by 20-70 Mev S,3+ projectiles in collisions with neutral gas targets of He, Ne and Ar is investigated. For NTE, positively charged projectiles undergo excitation and electron capture in a single collision in which the capture and excitation processes are independent events. The mechanisms involved in the NTE process are electron-nucleus interactions, and the combination of projectile excitation and capture is a two-step process. In this work, NTE cross sections, along with total K x-ray production cross sections and total single-electron capture and loss cross sections, were measured as a function of projectile energy. The …


Topology Based Routing Algorithms For Multilayer Ic Layout Design, Moazzem Hossain Apr 1993

Topology Based Routing Algorithms For Multilayer Ic Layout Design, Moazzem Hossain

Masters Theses

In this thesis, we consider the multilayer topological routing problem and also the geometric routing problem based on topological routing solution. We show that the problem of multilayer topological planar routing for any arbitrary routing region can be modeled as a problem in a simple closed routing region. We also show that the solution to the multilayer planar routing leads to a better result of the topological via minimization problem. We present a provably-good approximation algorithm for the multilayer topological planar routing problem for different routing regions.

We also propose a graph theoretic algorithm to find 2-layer topological solutions that …


Impurity Modes In Photonic Band Structures, Yi-Fen Chang Apr 1993

Impurity Modes In Photonic Band Structures, Yi-Fen Chang

Masters Theses

In this thesis I study a theoretical model of one-dimensional dielectric array (a layered system of dielectric slabs) which forms a periodic dielectric system in which band gaps are opened in the frequency spectrum. Specifically, we study such a one-dimensional array with linear impurities introduced in the periodic dielectric system. In these impurity structures narrow resonant modes are found in the band gaps as impurity modes and these impurity modes change with the dielectric constant. This impurity problem is similar to the donor and acceptor state problem in electronic semiconductors. The calculations presented in this thesis are based on numerically …


Ground-Water Contamination By Volatile Organic Compounds: Sources Of Error, Temporal And Spatial Variability, Gary Thomas Blinkiewicz Apr 1993

Ground-Water Contamination By Volatile Organic Compounds: Sources Of Error, Temporal And Spatial Variability, Gary Thomas Blinkiewicz

Masters Theses

Data on the distributions of VOC’s (volatile organic compounds), principally trichloroethane and dichloroethylenes, in a shallow sand and gravel aquifer near Rockford, IL have been collected for a number of years. Synoptic sampling events from a dense monitoring well network within a greater than 4 mi^2 area, provide the basis for the evaluation of sources of variability in concentrations in space and time. Sampling, and analysis-related variability in these data contribute less than 10% of total variance. Spatial and temporal variability over periods of months to years are significant Results suggest that contaminant distributions can be resolved best by using …


Improved Filter-Pack Design For Hydrocarbon Recovery Wells In Unconsolidated Aquifers, Thomas R. Barrett Apr 1993

Improved Filter-Pack Design For Hydrocarbon Recovery Wells In Unconsolidated Aquifers, Thomas R. Barrett

Masters Theses

Laboratory sand tank experiments and two field studies were conducted to determine filter-pack designs that would increase the hydrocarbon flow rate into hydrocarbon recovery wells. Previous laboratory experiments have shown that using filter-packs of Teflon chips or sands treated with a water repellent spray will increase the rate of hydrocarbon recovery into wells in laboratory bail down test experiments.

The results of the laboratory investigations suggest that using a hydrophobic filter-pack with a median grain-size of 2.5-3.5 greater than that of the aquifer will provide the greatest rate of hydrocarbon recovery.

In two field studies, wells constructed with a hydrophobic …


A Preliminary Study Using The Willow Cutting Method To Reduce Lake Shoreline Erosion, Jeffrey L. Bushur Jan 1993

A Preliminary Study Using The Willow Cutting Method To Reduce Lake Shoreline Erosion, Jeffrey L. Bushur

Masters Theses

The Charleston Side-Channel Reservoir has been experiencing extensive shoreline erosion since its completion in 1982. A diagnostic/feasibility study of the reservoir in 1992 rated shoreline erosion as the second largest source of sedimentation. Sedimentation reduces the reservoir volume, increases nutrient loading, and increases water turbidity.

As a part of Clean Lakes Program Phase II, the use of willow cuttings for bank stabilization was proposed as a possible treatment for shoreline erosion. While the use of willows for streambank stabilization has been extensively reported, lake documentation is rare. This experiment determined the feasibility of such action for the Charleston Side-Channel Reservoir …


Method Development In Coal Extraction, Yunsong Tong Jan 1993

Method Development In Coal Extraction, Yunsong Tong

Masters Theses

Organic sulfur compounds in coal should be removed as completely as possible in order to make coal "clean" during its usage. Before any method for coal desulfurization can be investigated, the structure of coal should be known. Soluble substances in coal are more easily analyzed by spectroscopic methods than is the insoluble coal. The goal of this research is to separate soluble organic sulfur compounds from the original coal by pyridine extraction. The weight percentages of the coal extracts obtained from three different coal samples by single step extractions ranged from 8% to 30%. The coal extractability could also be …


Concentration And Distribution Of Phosphate In The Sediment Of The Charleston Side Channel Reservoir, Nancy A. Johnson Jan 1993

Concentration And Distribution Of Phosphate In The Sediment Of The Charleston Side Channel Reservoir, Nancy A. Johnson

Masters Theses

The Charleston Side Channel Reservoir (CSCR) is located on the southeast edge of the City of Charleston in Coles Co., IL. The CSCR is the sole source of public drinking water for the city and also provides for a variety of recreational activities. Water quality in the CSCR has deteriorated since its construction in 1981, leading to its classification as hypereutrophic. The presence of high levels of phosphate are of particular concern having contributed to an increase in algal blooms and high turbidity.

In order to assess the role of internal loading of phosphate from the sediment, thirty-five sample sites …


Synthesis And Characterization Of Transition Metal Polypyridyl Complexes With A Novel 1,10-Phenanthropteridinedione Ligand, Huakai Huang Jan 1993

Synthesis And Characterization Of Transition Metal Polypyridyl Complexes With A Novel 1,10-Phenanthropteridinedione Ligand, Huakai Huang

Masters Theses

A new alloxazine ligand (1; "Pptd"), produced by the condensation of 1,10-phenanthroline-5,6-dione with 5,6-diamino-1,3-dimethyluracil, and several transition metal complexes containing this ligand, have been synthesized. The Pptd ligands attach to Ru(II), Co(II), or Re(I) metal centers through the phenanthroline linkage to form stable polypyridyl complexes. The spectral and the electrochemical characterization of Pptd complexes of Ru(II), Co(II), and Re(I) is presented.

Pptd is capable of being reduced (across the pyrazine nitrogens) by two H-atoms. When coordinated to Ru(II), Pptd forms stable complexes which retain the robust characteristics and electrochemical activity of other Ru(II) polypyridyl species. In addition, Ru(II) complexes of …


Inhibition Of Total Gas And Methane Production In Anaerobic Digestion By Various Toxicants, Steven H. Malehorn Jan 1993

Inhibition Of Total Gas And Methane Production In Anaerobic Digestion By Various Toxicants, Steven H. Malehorn

Masters Theses

Heavy metal inhibition of anaerobic digestion of municipal sewage sludge has been investigated over the past 50 years. Many assays began with steady-state conditions and observed the rate at which total gas or methane production decreased due to toxicant inhibition. These methods required considerable time and labor. Modified Warburg respirometers and serum bottle assays reduced much of the effort, but each method has limitations in terms of complexity, cost, and accuracy.

This series of experiments had two objectives: 1) develop a quick, inexpensive, and easy method to measure methanogenic activity in anaerobic digesters, and 2) determine median inhibitory concentrations (IC …


Ecology Of The State Endangered Yellow Mud Turtle, Kinosternon Flavescens In Henry Co., Illinois, Michael W. Tuma Jan 1993

Ecology Of The State Endangered Yellow Mud Turtle, Kinosternon Flavescens In Henry Co., Illinois, Michael W. Tuma

Masters Theses

Illinois populations of the state endangered yellow mud turtle (Kinosternon flavescens) persist in scattered locations on sand prairies. The largest population occurs on a remnant sand prairie of the former Green River Marsh in Henry Co. A study was conducted during 1992 to determine important criteria for preserve design. These criteria included extent of turtle movements within the site and habitat use. Turtles were captured by aquatic hoop traps, drift fence, and by hand from May 11 to August 31. A total of 16 adults, four juveniles, and eight hatchlings were captured. Population size was estimated at 44.80 adults using …


Vegetation And Tree Survival In A Savanna Restoration Project, Vermilion County, Illinois, Mary Claire Hruska Jan 1993

Vegetation And Tree Survival In A Savanna Restoration Project, Vermilion County, Illinois, Mary Claire Hruska

Masters Theses

This study involved pre-burn and post-burn inventories of herbaceous and woody vegetation, a post-burn tree survival survey, the development and implementation of a management plan for the savanna restoration site and the development of general guidelines for savanna restoration. An herbarium collection was made, 242 species representing 64 families were found on the site.

There were several significant changes in the density and frequency of vegetation after the burn. The following herbaceous species increased significantly in frequency: Agalinis tenuifolia (Vahl.) Raf, Ambrosia artemisiifolia L., Carex spp., Cassia fasciculata Michx., Desmodium glabellum (Michx.) DC., Dichanthelium acuminatum (Sw.) Gould & Clark var. …


An Object Oriented Preemptive Multitasking Kernel, Lee Gene Shipman Jan 1993

An Object Oriented Preemptive Multitasking Kernel, Lee Gene Shipman

Masters Theses

“This paper describes a preemptive multitasking kernel designed and coded using C++ using an object oriented paradigm. The kernel design, while implemented on an Intel 80386 based IBM PC running MS-DOS 4.01, can be ported to any platform, rewriting only the low level, hardware specific code.

The kernel, in application framework form, enables the applications developer to create real-time multitasking applications. This can be done in a systematic way by capitalizing on the power of object oriented program development.

A simulation was created to verify the correctness of the kernel against a traditional non-multitasking approach. This simulation provides the proof …


X.500 Directory Service Support For Electronic Mail, Mihai G. Sirbu Jan 1993

X.500 Directory Service Support For Electronic Mail, Mihai G. Sirbu

Masters Theses

"One of the difficult problems on the Internet is finding the electronic mail addresses of users. In practice, there are some indirect ways of finding these addresses such as the finger program in UNIX, but almost all of these methods require the user to know the exact host name of the destination. What is most desirable is an automated mechanism which provides the e-mail addresses of users if some minimal information about the destination site is known.

This thesis describes the design of such a directory service support system, based on the X.500 Series of CCITT Recommendation, for the elm …


Pargal: A Package For Parallel Graph Algorithms, Winston Anand-Kumar Dec 1992

Pargal: A Package For Parallel Graph Algorithms, Winston Anand-Kumar

Masters Theses

In this thesis, we have considered three graph problems namely, spanning forest problem, connected component problem and minimum cost spanning forest problem. Standard methods to solve these problems using sequential algorithms by various authors are presented for each problem. Efficient parallel algorithms for these problems have also been presented by various authors; however, most of these solutions demands a need for large number of processors, which immediately increases the cost of the hardware and in most of the cases it seems not very practical.

We present efficient solutions for the three problems on a hypercube parallel computer using p processors. …


Use Of Geology And Petrophysics In The Characterization Of St. Peter Sandstone Reservoirs, Rusli Bin Adam Dec 1992

Use Of Geology And Petrophysics In The Characterization Of St. Peter Sandstone Reservoirs, Rusli Bin Adam

Masters Theses

Core samples and petrophysical data from three reservoir intervals within the Middle Ordovician St. Peter Sandstone in the Michigan basin were utilized to assess the reservoir performance. Each reservoir interval coincides with major sedimentary facies which are in gradational contact with one another vertically and laterally throughout the basin. Reservoirs in the lower portions of the formation (reservoir type 1) are dominated by meso-intercrystalline porosity. This predominantly quartz cemented reservoir rock type is characterized by low porosity with high permeability, moderate pore apertures, and moderate irreducible water saturation. Reservoirs at the top of the formation (reservoir type 3) are dominated …


A Computer Simulation Of The Rotary Vacuum Filter Brown Stock Washing System Using Distribution Sampling, Edison G. Yiu Dec 1992

A Computer Simulation Of The Rotary Vacuum Filter Brown Stock Washing System Using Distribution Sampling, Edison G. Yiu

Masters Theses

A probabilistic model was utilized to simulate the brown stock washing system's error due to process variability and measurement noise. Mass balances of the washing system were performed using distribution sampling. This model relies on a nonlinear relationship between displacement and dilution, which permitted the generation of displacement ratio based upon wash liquor ratio. Experimental trials were performed on a pilotscale rotary vacuum single-stage washer. Nonlinear first-order relationship appears to characterize a pilotscale washer adequately. Differences were observed between the means and standard deviations of the measured results compared to the simulation output. Future work is needed to identify the …


A Study Of Ground-Water Quality In A Priority Agricultural And Livestock Watershed, Cass County, Michigan, Matthew Alan Stuk Dec 1992

A Study Of Ground-Water Quality In A Priority Agricultural And Livestock Watershed, Cass County, Michigan, Matthew Alan Stuk

Masters Theses

A study of ground-water contamination in a shallow, sandy, glacial drift aquifer was performed in a watershed dominated by swine feedlots and crop fields in Cass County, Michigan. Monitoring wells were installed and sampled to study the flow pattern, chemistry, and contamination of ground water.

Results of chemical analyses show contamination from fertilizers and other soil-applied chemicals as well as the infiltration of breakdown products from pig waste. Shallow wells in impacted areas show potassium and nitrate from the breakdown of fertilizers, calcium from field application of lime, and additional nitrate from pig waste. Elevated calcium, potassium, and nitrate concentrations …


An Efficient Over-The-Cell Routing Algorithm For High Performance Circuits, Sivakumar Natarajan Dec 1992

An Efficient Over-The-Cell Routing Algorithm For High Performance Circuits, Sivakumar Natarajan

Masters Theses

In this thesis, we present a three-layer and a two-layer over-the-cell (OTC) channel routing algorithm (WILMA3 and WILMA2 respectively) for high speed circuits. This router not only minimizes the channel height by using over-the-cell areas but also achieves the net’s timing requirements.

We have implemented our routers in C on SUN Sparc 1+ workstation and tested it on MCNC benchmarks Primary I and II. Experimental results show that WILMA3 can achieve results which are 72% better (on the average) than the conventional two layer channel router, 61% better than two layer over-the-cell router and 51% better than three layer greedy …


Eztex: A Graphical User Interface System For Latex, Ravi K. Kosaraju Dec 1992

Eztex: A Graphical User Interface System For Latex, Ravi K. Kosaraju

Masters Theses

No abstract provided.


An Integrated Simulation Model Development Environment For Slam Ii Using Object-Oriented Paradigm, Rizvan Erol Dec 1992

An Integrated Simulation Model Development Environment For Slam Ii Using Object-Oriented Paradigm, Rizvan Erol

Masters Theses

An integrated simulation model development environment was implemented to assist the modeler by automating certain activities of simulation modeling. The system included interactive model definition, experimental design, automatic simulation program generation in SLAM II. Object-oriented paradigm at software development stage was extensively used to conceptualize the structure, and rules of the SLAM II language in order to generate efficient, and modular program code. The present system targeted modeling of various probabilistic inventory control system problems. The remarkable advantages of the system were rapid model development time, and achieving reliable program code without requiring any knowledge in SLAM II. Object-oriented programming …


Improved Global Routing Using ⋋-Geometry, Surendra Burman Dec 1992

Improved Global Routing Using ⋋-Geometry, Surendra Burman

Masters Theses

No abstract provided.


Synthesis Of Symmetric And "Mixed-Ligand" Homocyclopentadienyl Ruthenocenes, John Adjeiku Amanfu Dec 1992

Synthesis Of Symmetric And "Mixed-Ligand" Homocyclopentadienyl Ruthenocenes, John Adjeiku Amanfu

Masters Theses

No abstract provided.