Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Western Michigan University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 18601 - 18630 of 19508

Full-Text Articles in Physical Sciences and Mathematics

Extensions Of Two-Part Tests To Compare K Independent Populations, Marwan Daoud Dec 2007

Extensions Of Two-Part Tests To Compare K Independent Populations, Marwan Daoud

Dissertations

We consider two-part models that are mixtures of a point-mass variable with all mass at zero and a continuous random variable. The model may assume a particular distributionh(x) for the continuous part such as a log-normal or a gamma. The response variable is defined as y=(x, d), where d=1 if x > 0 and d=0 if x = 0. The probability distribution function has the following form: fx,d=p 1-d×1-p ×hx d.

Lachenbruch (1976, 2001) proposed several tests to compare means of two populations for this type of data. We proposed a two-part Wald test and …


Geosciences Newsletter- 2007, Department Of Geosciences Nov 2007

Geosciences Newsletter- 2007, Department Of Geosciences

Geological and Environmental Sciences News

Vol. 2, No. 3

  • Dear Friends and Alumni
  • Faculty News
  • Publications
  • Grants
  • Michigan Geological Repository for Research and Education
  • Department Updates
  • Graduate Student News
  • Internships
  • Awards and Graduations
  • Alumni News
  • Donations


Wireless Passive Surface Acoustic Wave (Saw) Sensing System, Sridevi Krishnamurthy Aug 2007

Wireless Passive Surface Acoustic Wave (Saw) Sensing System, Sridevi Krishnamurthy

Dissertations

Due to their small size and ruggedness, Surface Acoustic Wave (SAW) devices have been widely used as part of wireless sensing or identification system especially in inaccessible and inhospitable environments. In addition, SAW devices find widespread applications as filters in communication systems and also as physical, chemical and bio-sensors and ID tags. The passive wireless SAW sensing system mainly consists of a passive SAW sensor and an interrogation unit which sends a burst signal to the SAW sensor and processes the sensor response. Theobjectives of this work were designing, prototyping and fabricating the interrogation unit on a PCB and also …


The Effect Of Chloramphenicol On Bb88 Murine Erythroleukemia Cells, Peter K. W. Harris Aug 2007

The Effect Of Chloramphenicol On Bb88 Murine Erythroleukemia Cells, Peter K. W. Harris

Dissertations

DNA microarrays can be used to measure genome-wide transcript levels. These measurements may be useful in understanding cellular changes induced by a chemical agent. In this study, Affymetrix microarray technology has been used to study the effects of chloramphenicol, an antibiotic that inhibits bacterial and mitochondrial protein synthesis, on the transcription profile in mammalian cells. Transcript levels in BB88 murine erythroleukemia cells treated with 50 micromolar ( mu M) chloramphenicol, a concentration shown to inhibit BB88 proliferation, are measured. Using total RNA from treated cells, biotin-labeled cRNA was prepared and hybridized to Affymetrix U74Av2 microarrays. From these hybridizations, expression levels …


Synthesis And Characterization Of Doped Core/Shell Quantum Dots, Elizabeth J. Sodt Aug 2007

Synthesis And Characterization Of Doped Core/Shell Quantum Dots, Elizabeth J. Sodt

Masters Theses

The central theme of the research performed is the systematic modification of the optical properties of quantum dots by the formation of a shell of another quantum dot of a different band gap energy. Core/shell quantum dots such as CdS:Mn/CdS, CdS:Mn/ZnS, and ZnS:Mn/CdS with various concentrations of dopant Mn2+ in the core and shell concentrations have been synthesized under mild conditions in the aqueous phase using stoichiometric amounts of the surfactant stabilizer dodecyl sulfate. These quantum dots exhibit UV-vis, emission, and electron paramagnetic resonance (EPR) spectral behavior that is dependent on the concentration of the shell and the dopant …


Nitrogen Heterocyclic Compounds As Receptors In Nanosensors For Nerve Gas Agent Analogs, Swapna Katram Aug 2007

Nitrogen Heterocyclic Compounds As Receptors In Nanosensors For Nerve Gas Agent Analogs, Swapna Katram

Masters Theses

The research is focused on developing nanosensors consisting of different components that are chemically linked, namely, nanoparticle, fluorescent monomer, and receptor (NMR sensors) and nanoparticle, monomer, nanomolecule, and receptor (NMNR sensors) for the sensitive and selective detection of nerve gas agents. These sensors detect the target toxins by fluorescence change which is amplified by signal transduction. Model nerve gas toxins (DCP) and (DMMP) and HCl were employed as analytes, and the nitrogen heterocyclic compounds, 5-aminoindazole and dipyrido[3,2-a:2',3'-c]phenazine (dppz) as receptors in the NMR and NNMR nanosensors. The monomers were (E)-4-(4- formylstyryl) benzoic acid (NMR sensor) and 2-mercaptosuccinic acid (NNMR sensor). …


Modified Fenton Oxidation Of Hydrocarbon Contaminated Soils With Cao2: Microbial Survival And Surfactant Production, Abraham Matthew Northup Aug 2007

Modified Fenton Oxidation Of Hydrocarbon Contaminated Soils With Cao2: Microbial Survival And Surfactant Production, Abraham Matthew Northup

Dissertations

The efficacy of CaO2 for use in modified Fenton's (MF) reactions was investigated in this study, with the goal of developing a CaO2-based MF oxidation technology for use in in situ chemical oxidation. Traditionally, liquid H2O2 (HP) is used, and is injected into the subsurface in excess to ensure a sufficient radius of influence. CaO2 was investigated as an alternative source of H2O2 for MF reactions.

First, the rate of dissolution of powdered CaO2 and the yield of HP was investigated. Our results showed that the rate of dissolution …


Physics Department News, June 2007, College Of Arts And Sciences Jun 2007

Physics Department News, June 2007, College Of Arts And Sciences

Physics Newsletter

Contents from Volume 6, Issue 1:

  • What’s New at the University
  • Faculty Highlights
  • Alumni Achievement Awards
  • More Alumni News
  • Staff Highlights
  • Soga Center Opens
  • Student News
  • Annual Student Awards
  • Recent Graduates
  • Book Awards
  • Department Roster
  • Feedback Form


The Global Hepatic Transcriptional Response Of Male Fisher Rats To Dietary Aroclor 1254 Exposure, Trisha M. Basford Jun 2007

The Global Hepatic Transcriptional Response Of Male Fisher Rats To Dietary Aroclor 1254 Exposure, Trisha M. Basford

Dissertations

Dietary intake is a primary route for biomagnification of environmentally persistent polychlorinated biphenyls (PCBs) within humans and animals. Aroclor 1254, a mixture of PCBs, is associated with a variety of toxic responses including alterations in blood and lipid biochemistry and tumor promotion. Measurement of the transcriptional responses to low-level dietary exposure to A1254 has not been reported to date, and is important given the persistence of PCBs, and range of effects associated with exposure. The aims of this study were to characterize changes in rat hepatic global gene expression due to sub-acute and sub-chronic dietary exposure to A1254, and to …


Inelastic X-Ray Scattering Studies On Organic Semiconductors And Organic Superconductors, Chaminda Nalaka Kodituwakku Jun 2007

Inelastic X-Ray Scattering Studies On Organic Semiconductors And Organic Superconductors, Chaminda Nalaka Kodituwakku

Dissertations

We have measured electronic excitations and excitons in CuPc polycrystalline and single crystal samples. Measurements on the polycrystalline sample were done with 300 meV resolution and measurements on the single crystal were done using 120 meV resolution. Time dependant density functional theory (TD-DFT) calculations were done on the CuPc molecule to understand the electronic excitations in this system.


Some Applications Of Gaussian Quadrature And Neural Network Modeling In Earth Flows And Other Slow-Moving Landslides In Cohesive Slope Materials, Rennie Bwalya Kaunda Jun 2007

Some Applications Of Gaussian Quadrature And Neural Network Modeling In Earth Flows And Other Slow-Moving Landslides In Cohesive Slope Materials, Rennie Bwalya Kaunda

Dissertations

Geometrical changes and progressive displacements in earth flows and other slow moving landslides triggered by climatic changes may be addressed by digital modeling. Gaussian quadrature, a numerical integration technique though fixed points, is employed to compute geometrical areas defined by stratigraphic (soil or rock layering) units, vertical pole projections and a slip surface, based on kinematic admissibility. An example from the Lake Michigan coast shows that the total internal geometrical area is found to be preserved during the course of the progressive deformation. Displacement monitoring of the slope shows that it became less stable over a period of eleven years …


A New Model For Cooperative Mobility In Support If Qos In Manets With Heterogeneous Autonomy Requirements, Ghassen Ben Brahim Jun 2007

A New Model For Cooperative Mobility In Support If Qos In Manets With Heterogeneous Autonomy Requirements, Ghassen Ben Brahim

Dissertations

Modern mobile ad-hoc networks (MANETs) frequently consist of nodes which exhibit a wide range of autonomy needs. This is particularly true in the settings where MANETs are model compelling, i.e. battlefield, response & rescue, and contexts requiring rapid deployment of mobile users. The time-critical nature of the underlying circumstances frequently requires deployment of both manned and unmanned nodes, and a coordination structure which provides prioritized tasking to them.

In classic ad-hoc networks settings, it is assumed that all nodes are autonomous and do not depend in any case on other nodes. In this research work, contrarily to this design, we …


The Fock Space And Related Bergman Type Integral Operators, Ovidiu Furdui Jun 2007

The Fock Space And Related Bergman Type Integral Operators, Ovidiu Furdui

Dissertations

In this thesis we study the boundedness of a general class of integral operators induced by the kernel functions of Fock spaces. More precisely, for a, b, and c real parameters we study the action of [Special characters omitted.] and [Special characters omitted.] on Lp ([Special characters omitted.] ,dvs ), where dvs ( z ) = [Special characters omitted.] is the Gaussian probability measure on [Special characters omitted.] . We prove that, when p > 1, respectively p = 1, these operators are bounded if and only if p satisfies a quadratic, respectively a linear, inequality. The …


Measures Of Travers Ability In Graphs, Futaba Okamoto Jun 2007

Measures Of Travers Ability In Graphs, Futaba Okamoto

Dissertations

For a connected graph G of order n ≥ 3 and a cyclic ordering sc : v 1, v2,..., vn, v n+1 = v1 of vertices of G, the number d(sc) is defined by d(sc) = i=1n d(vi, vi +1), where d(vi, vi +1) is the distance between vi and vi+1 in G for 1 ≤ i ≤ n. The Hamiltonian number h(G) and upper Hamiltonian number h +(G) of G are defined as h(G) = min{d(sc)} and h+(G) = max{d(sc)}, respectively, where the minimum and maximum are taken over all cyclic orderings s c of vertices of G. For …


Towards A Better Understanding Of The Hydrology Of The Tigris- Euphrates System And Its Marshlands, Christopher K. Jones Jun 2007

Towards A Better Understanding Of The Hydrology Of The Tigris- Euphrates System And Its Marshlands, Christopher K. Jones

Masters Theses

Rising demands for fresh water supplies are leading to water management practices that are altering natural flow systems world-wide. One of the most devastated of these natural systems is the Tigris-Euphrates watershed that over the past three decades has witnessed the construction of over 60 engineering projects that eliminated seasonal flooding, reduced natural flow and dramatically reduced the areal extent (1966: 11000 km2 ; 2002: 750 km2) of the Mesopotamian Marshes downstream. We constructed a continuous (1964 to 1998) catchment-based rainfall runoff model for the entire Tigris-Euphrates watershed (area: one million km2) using the SWAT …


Laboratory Based Chemical And Isotopic Investigations On Biotic (Microbial) And Abiotic Reduction Of Iron And Oxidation Of Organic Compounds, Tsigabu Asmelash Gebrehiwet Jun 2007

Laboratory Based Chemical And Isotopic Investigations On Biotic (Microbial) And Abiotic Reduction Of Iron And Oxidation Of Organic Compounds, Tsigabu Asmelash Gebrehiwet

Dissertations

Studies using chemical and isotopic techniques have been conducted to investigate experimental microbial (biotic) iron reduction and abiotic redox processes. In the microbially mediated study Fe(III) reduction and lactate oxidation at circum-neutral pH and anaerobic conditions were used to characterize the metabolic pathways followed by dissimilatory Fe+3 -reducing bacterium Shewanella putrefaciens strain 200R. Iron (II), Iron (III), dissolved inorganic carbon (DIC) and carbon isotope ratios were measured under bicarbonate and phosphate buffered conditions. Carbon isotope disproportionation among organic carbon substrate (lactate), biomass and respired carbon dioxide at the lag to stationary phase of the microbial growth curve showed …


Stability Testing Of Mint Oils Through Gas Chromatography Analysis, Sarah Wolf May 2007

Stability Testing Of Mint Oils Through Gas Chromatography Analysis, Sarah Wolf

Honors Theses

In this experiment, the stability of mint oil was measured through gas chromatography analysis. Eight different oils were tested. Levels of key components of mint oil, including menthol and menthone for peppermint oil, and carvone and limonene for spearmint oil, was compared over time. Several packaging materials were immersed in oils in order to determine their effects, if any, on the composition of the oils. Additionally, oil was subjected to either 25 degree or 40 degree Celsius temperatures to determine if temperature affected the oil composition.


Bioengineering Of Protein Nanotubes And Protein Nanomaterial Composites, Thilak Kumara Mudalige May 2007

Bioengineering Of Protein Nanotubes And Protein Nanomaterial Composites, Thilak Kumara Mudalige

Dissertations

Flagella of Mesophilic bacteria such as E. coli are extremely ordered structures consisting of self-assemblies of flagellin 11-mers resulting in protein nanotubes of 2--3 nm inner diameter, 23 nm outer diameter, several microns in length and 5.4 nm separation between 11-mer segments. They are as a result attractive scaffolds and templates for the generation of uniform nanotubes and ordered array of nanoparticles. In this study fusion protein of bacterial flagellin (Fli C) and core thioredoxin (Trx), pFliTrx was used as peptide display on bacterial flagella. This was accomplished in the current research by introducing various peptide loops such as cysteine, …


Global And Quantitative Gene Expression Analysis Of The Effects Of Drinking Water Exposure To Lead Acetate In Fisher 344 Male Rats Liver, Worlanyo Eric Gato Apr 2007

Global And Quantitative Gene Expression Analysis Of The Effects Of Drinking Water Exposure To Lead Acetate In Fisher 344 Male Rats Liver, Worlanyo Eric Gato

Dissertations

The primary objective of this research is to analyze global gene expression patterns occurring in Fisher 344 rat livers exposed to varying levels of lead and times. The hypotheses were that: (1) effects associated with Pb exposure are both dose and time dependent and (2) several genes will be over-expressed or repressed including transcripts associated with calcium signaling. Initially, the effects of Pb exposures upon morphometnc indices, liver and kidney tissue histology, Pb distribution, Pb interaction with other trace metals including Zn, Cu, Co, Fe, Ni and Ca were assessed. Results showed a significant accumulation of lead in blood, liver, …


Heterogeneous Formation Of Hono On Hno3 Pre-Conditioned Hydrophobic, Hydrophilic And Ionic Surfaces At Various Relative Humidities, Dustin S. Wier Apr 2007

Heterogeneous Formation Of Hono On Hno3 Pre-Conditioned Hydrophobic, Hydrophilic And Ionic Surfaces At Various Relative Humidities, Dustin S. Wier

Masters Theses

Nitric acid (HNO3) is a major sink for NOx (NO+NO2 ) and is known to be removed from the atmosphere as a result of wet and dry deposition where it is then deposited on various surfaces in the environment. As these surfaces are photolyzed HONO is produced which affects the overlying troposphere. This study examines the amount of HONO (Nitrous Acid) produced by the photolysis of adsorbed HNO3 as a function of changing relative humidity on hydrophobic, hydrophilic, and inorganic ionic salt surfaces. The amount of HONO produced was measured in long path cell using …


Biochemical Characterization Of Disease-Causing Mutation In N-Terminal Wilson Protein Domain Six, Patrick Ochieng Apr 2007

Biochemical Characterization Of Disease-Causing Mutation In N-Terminal Wilson Protein Domain Six, Patrick Ochieng

Masters Theses

Wilson protein (ATP7B) is a copper-transporting P-type ATPase that regulates copper homeostasis and secretion of copper-containing enzymes in the liver. In hepatocytes, ATP7B delivers copper to apoceruloplasmin and mediates the excretion of excess copper into bile. Mutation in the gene coding for Wilson protein leads to Wilson disease. Several mutations in Wilson protein have been identified and of particular interest, mutations affecting the N-metal binding region significantly interfere with the ability of Wilson protein to transport copper to its target in the copper-trafficking pathway. In an attempt to characterize the disease-causing mutation (G591D) in Wilson protein domain 6 (WLN6), we …


Development Of Scanning Electrochemical Microscopy For Studying Electron Transport In Lipid Monolayers And Gold Nanoparticle Films, Violeta Stoycheva Apr 2007

Development Of Scanning Electrochemical Microscopy For Studying Electron Transport In Lipid Monolayers And Gold Nanoparticle Films, Violeta Stoycheva

Masters Theses

The focus of this thesis is the scanning electrochemical microscopy (SECM) investigation of the electron transport in lipid monolayers and in films of gold nanoparticles. The quality and stability of lipid monolayers were characterized by various analytical techniques such as fluorescence microscopy and spectroscopy, contact angle, and electrochemistry using a monolayer modified electrode. In the SECM measurement, the monolayer electron transport was not detected. The microscopic monolayer quality turned out to be not suitable for studying the electron transport.

The conductivity of mono layer protected gold clusters (MPCs) with different core sizes (1-3 nm diameter) were investigated using SECM. These …


Stratigraphy And Organic Carbon Contents Of Glacial Deposits In The City Of Portage, Michigan, U.S.A., Nathaniel A. Barnes Apr 2007

Stratigraphy And Organic Carbon Contents Of Glacial Deposits In The City Of Portage, Michigan, U.S.A., Nathaniel A. Barnes

Masters Theses

The objectives of this study are to characterize the stratigraphy of the glacial drift in an area located in Portage, Michigan using four complete rotasonic cores, and to determine the variation of organic carbon content in the drift that may explain the high iron concentrations in the groundwater typically obtained in moderate to deep wells in southwestern Michigan. The four cores were characterized in detail in terms of lithology, textural and statistical analyses, gamma ray logging, S13C variation and organic carbon analyses. Clay minerals were characterized using X-ray diffraction analysis.

Results of this study identified two main diamicton …


Transcriptional Regulation Of Glucose-6-Phosphate Dehydrogenase (G6pdh) By Glucose, Pramod U. Thekkat Apr 2007

Transcriptional Regulation Of Glucose-6-Phosphate Dehydrogenase (G6pdh) By Glucose, Pramod U. Thekkat

Masters Theses

In liver, insulin and glucose regulate the expression of important genes for lipid and carbohydrate homeostasis. Studies on the effects of glucose and insulin, including effects on cell signaling, are vital since deficiencies in glucose utilization in cells and/or insulin secretion contribute to conditions like obesity and diabetes. In liver, the pentose phosphate pathway is one of the primary pathways that can utilize the excess carbohydrate. Glucose-6-phosphate dehydrogenase (G6PDH) is an important rate limiting enzyme in this pathway. Our laboratory has shown that both insulin and glucose induce the expression of G6PDH, although the mechanism by which this transcriptional regulation …


Geophysical Monitoring Probes And Their Applications To Some Hydrogeological Problems, Laura Smart Apr 2007

Geophysical Monitoring Probes And Their Applications To Some Hydrogeological Problems, Laura Smart

Dissertations

Geophysical monitoring probes were constructed to monitor the vertical changes of water content and ion concentration in the subsurface. These devices contain electrodes for resistivity measurements and thermistors for temperature measurements. They are designed to monitor the resistivity and temperature of the saturated zone, the transition zone, and the vadose zone near a groundwater/surface water interface. Additional installations at the site include four monitoring wells and four Time Domain Reflectometry (TDR) access tubes, each paired with the geophysical probe installations. Pole-Pole resistivity measurements with an a-spacing of 5 cm are made using a CR1000 Campbell Scientific, Inc. datalogger. Automated data …


Late Pleistocene Climate Variability And Chemical Weathering In The Goriganga, Higher Central Himalaya, North India, Steven Paul Beukema Apr 2007

Late Pleistocene Climate Variability And Chemical Weathering In The Goriganga, Higher Central Himalaya, North India, Steven Paul Beukema

Dissertations

Relict lacustrine deposits in the Higher Central Himalaya, India, provide a rich repository of paleoclimate information for the period 16 ka to 11 ka. Stable isotope analysis of deposits near the village of Burfu shows the hydrologic balance between glacial meltwater and monsoon precipitation as source waters for the lake. During the period from 15.5 ka to 14 ka the Burfu lake was largely fed by melting glaciers. A warming event correlated to glacial Meltwater Pulse 1a indicates a sudden increase in carbonate weathering in the region accompanied by a gradual decrease in the ratio of glacial meltwater/monsoon precipitation feeding …


Lightweight Intrusion Detection: A Second Line Of Defense For Unguarded Wireless Sensor Networks, Vijay Subhash Bhuse Apr 2007

Lightweight Intrusion Detection: A Second Line Of Defense For Unguarded Wireless Sensor Networks, Vijay Subhash Bhuse

Dissertations

Wireless sensor networks (WSN) are formed of stationary nodes with stringent resources (in terms of battery power, processor speed, memory and radio range). They have specific communication and traffic patterns.

Making sensor networks secure is especially challenging because of the wireless medium and the fact that WSN is physically unguarded. The compromise of sensor nodes may lead to the loss of secret information and tampering of the software. Hence, intrusion detection techniques must be designed to detect at least some of the most dangerous attacks. Further, these techniques should be lightweight to suit resource constrained nature of WSN.

We focus …


Research Report 2007-2008, College Of Arts And Sciences Jan 2007

Research Report 2007-2008, College Of Arts And Sciences

Physics Research Reports

  • Introduction
  • From the Chairperson
  • Astronomy
  • Atomic Physics
  • Condensed Matter Physics
  • Nuclear Physics
  • Physics Education
  • Publications
  • Dissertations
  • Presentations
  • Proposals and Grants
  • Scholarly Activity
  • Personnel


Geosciences Newsletter - 2006, Department Of Geosciences Dec 2006

Geosciences Newsletter - 2006, Department Of Geosciences

Geological and Environmental Sciences News

Vol. 2, No. 2

  • Mohamed Sultan, Chairperson
  • Faculty News
  • Department News
  • Michigan Geological Repository for Research and Education (MGRRE)
  • Department Updates
  • Graduate Student News
  • Awards & Graduations
  • Alumni News
  • Outstanding Alumni Academy
  • Dedication Ceremony Michigan Geological Repository for Research and Education (MGRRE) New Faces in the Geosciences


Physics Department News, December 2006, College Of Arts And Sciences Dec 2006

Physics Department News, December 2006, College Of Arts And Sciences

Physics Newsletter

Contents from Volume 5, Issue 2:

  • Editor’s Note
  • From the Chair
  • What’s New at the University
  • Faculty Highlights
  • Staff Highlights
  • PhysTEC
  • International Week
  • ICPEAC Program Meeting
  • Student News
  • Annual Student Awards
  • Recent Graduates
  • Department Roster
  • Photo Gallery
  • Feedback/Update Reply Form