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Masters Theses

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Articles 1591 - 1620 of 2697

Full-Text Articles in Physical Sciences and Mathematics

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 …


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 …


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 …


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 …


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 …


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 …


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. …


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 …


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 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.


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.


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 …


Construction Of A Lithium Vapor Oven For Electron Capture And Multiple Ionization Experiments, Oliver Woitke Aug 1992

Construction Of A Lithium Vapor Oven For Electron Capture And Multiple Ionization Experiments, Oliver Woitke

Masters Theses

A Li vapor oven, to be used as a source of Li target atoms in electron capture and multiple ionization experiments, was designed and installed in the beamline of the Van de Graaff accelerator at Western Michigan University. The oven was tested using two different projectile beams, protons and He+. The test results indicate that Li evaporated from the oven in the form of a cloud rather than as a jet spray. For He+ colliding with Li it was found that the projectile single-electron loss yield is about three orders of magnitude larger than the single-electron capture yield, as expected …


A Study Of The Transfer Matrix Method For The Classical Statistical Mechanics Of One Dimensional Systems, Dietmar R.A. Johlen Aug 1992

A Study Of The Transfer Matrix Method For The Classical Statistical Mechanics Of One Dimensional Systems, Dietmar R.A. Johlen

Masters Theses

Two formalisms using the transfer matrix technique, the first one by Gupta and Sutherland (1976) and the second one by Guyer and Miller (1979), are investigated and a proof is given for their equivalence.

Furthermore, it is pointed out that previous studies neglected the difficulties that arise from nonhermitian pseudo Hamiltonian. This work proves that the same results are obtained by taking into account the nonhermiticity of the pseudo Hamiltonian.

Thus, the transfer integral technique is extended to nonhermitian pseudo Hamiltonians.


Charge Conservation In The Incommensurate-Commensurate Transition Of Charge Density Waves, Jörg Kastrup Aug 1992

Charge Conservation In The Incommensurate-Commensurate Transition Of Charge Density Waves, Jörg Kastrup

Masters Theses

W ith the complex continuation method, introduced by Gupta and Sutherland (1976), the grand partition function for the sine-Gordon model of charge density waves may be calculated without violation of charge conservation. Contrary to previous works by Okwamoto, Takayama and Shiba (1979) and Turkevich and Doniach (1982) the chemical potential becomes temperature dependent. By direct comparison of numerical results with those of the above mentioned authors it is shown that the incommensurate-commensurate transition does not occur in the previously predicted temperature range.


Localization Of Light In One Dimensional Randomly Disordered Dielectric Medium, K. Balaji Aug 1992

Localization Of Light In One Dimensional Randomly Disordered Dielectric Medium, K. Balaji

Masters Theses

The concept of localization of electrons in semiconductors has been known ever since the 1960's when P. W. Anderson and N. F. Mott made detail investigations on the transport properties of alloys. At the end of the last decade, however, physicist started looking for localization in other systems. Specifically, they looked at the localization of light and acoustic waves in disordered systems. Localization is a property which arises for all wavelike excitations in disordered media.

In this study we analyze the localization of light in one dimensional randomly disordered dielectric medium using computer simulation (numerical integration method) technique. The results …


Late Proterozoic Rifting Of Laurentia: Source And Deposition Of Conglomerate Units Of The Grandfather Mountain Formation, North Carolina Blue Ridge, Michael J. Neton Aug 1992

Late Proterozoic Rifting Of Laurentia: Source And Deposition Of Conglomerate Units Of The Grandfather Mountain Formation, North Carolina Blue Ridge, Michael J. Neton

Masters Theses

Crustal extension and initiation of rifting of Laurentia during the Late Proterozoic resulted in formation of a northeast-trending system of discontinuous to continuous, half-graben basins situated cratonward of the Iapetus Ocean spreading ridge. Thick accumulations of sandstone, siltstone, bimodal volcanic rocks, conglomerate, diamictite, and minor limestone were deposited largely in response to rifting and relief formation on the basin margins.

The Grandfather Mountain Formation contains five stratigraphically and compositionally distinct conglomerate/diamictite units and one pebbly sandstone unit which cap coarsening-upward, basin-fill sequences. The progradational sequences average 1300 m thick and are composed of a succession of volcanic flows (basalt/rhyolite) and/or …


Sequential And Parallel Discrete Event Simulation On Computer Communication Networks, Tao Zhou Jun 1992

Sequential And Parallel Discrete Event Simulation On Computer Communication Networks, Tao Zhou

Masters Theses

This thesis presents the discrete event simulation technique on the network design, focusing on the methodology, modeling and implementation. The developed technique is suitable for the analysis of any store-and-forward computer communication networks with any level of complexity. The proposed generic simulation model can be used to test the architectures and protocols of existing networks and networks being designed. In implementation of the sequential discrete event simulation, an object-oriented programming strategy is applied to the network simulation using the C++ language. The parallel discrete event simulation is introduced to solve the problem of long time execution of the sequential simulation …


Prediction Of Paper Color: A Process Simulation Approach, Mayank Chaturvedi Jun 1992

Prediction Of Paper Color: A Process Simulation Approach, Mayank Chaturvedi

Masters Theses

A simulation model was developed for a dye mixing process and for the prediction of the optical properties of the paper. The model was integrated with the MAPPS (Modular Analysis of Pulp and Paper Systems) simulation software package. The model was validated using dyed handsheets made in a laboratory and dyed paper made on a pilot papermachine. Validation comprised of prediction of the optical properties of the handsheets and the machine-made paper which contained various combinations of three non-fluorescent dyes. Sheet reflectances were predicted at 20 nanometer intervals for discrete light wavelength range of 400 to 700 nanometers and verified …


Synthesis Of Organometallic Polymers, Po-Chang Chiang Jun 1992

Synthesis Of Organometallic Polymers, Po-Chang Chiang

Masters Theses

By the middle of the nineteenth century, organic chemists found high molecular weight compounds as by-products of some of their experiments. These compounds were thought of as products of a failed reaction. It was not until sixty years ago that the first polymers were deliberately synthesized. Today polymers are used in almost every facet of life and they are becoming more important with each passing day.

This research project focused on synthesizing conducting organometallic polymers. By linking aromatic rings with transition metals, the resultant polymers should have good electrical conductivity because of the interaction of (a) the p electrons on …


Double Differential Cross Sections For State-Selective Electron Capture By Low-Energy Ar4+ And Ar5+ Ions From He And Ar, Serefettin Yaltkaya Jun 1992

Double Differential Cross Sections For State-Selective Electron Capture By Low-Energy Ar4+ And Ar5+ Ions From He And Ar, Serefettin Yaltkaya

Masters Theses

Doubly differential cross sections, in angle and energy, for state-selective single-electron capture from He and Ar by Ar4+ and Ar5+ ions have been studied experimentally at laboratory impact energies of 25q, 50q, and lOOq eV (q = 4 and 5, where q is the ion charge state) and at laboratory scattering angles between 0° and 5.5°, by means of translational energy spectroscopy. The translational energy-gain spectra show that only a few final states are selectively populated. Final-state transition probabilities were found to depend strongly on the charge state of the projectile ion and the ionization potential of the …


Optimal Control Of A Heat Flux In A Parabolic Partial Differential Equation, Katherine Renee Deaton May 1992

Optimal Control Of A Heat Flux In A Parabolic Partial Differential Equation, Katherine Renee Deaton

Masters Theses

We consider the problem of controlling the solution of a parabolic partial differential equation with non-homogeneous Neumann boundary conditions, taking the flux as the control. We take as our cost functional the sum of the L2 norms of the control and the difference between the temperature distribution attained and the desired temperature profile. We establish the existence of an optimal control that minimizes the cost functional. The optimal control is characterized in a constructive way through the solution to the optimality system, which is the original problem coupled with an adjoint problem. We establish existence and uniqueness of the …