Physical Sciences and Mathematics Commons^™

Nanosensors For The Detection Of Nerve Agents And Explosives, Deepak Kumar Thimmaraju

Masters Theses

The central hypothesis of this research was development of a novel nanosensor for the detection of nerve agents and explosives. The nanosensor assembly comprises a bottom up approach with nanoparticle (N), monomer (M), nanomolecule (N) and a receptor (R) as moieties of a NMNR assembly. My research was focused on evaluating receptors for their efficiency towards the target analytes such as nerve agents and explosives. Pi electron rich receptor 2-Phenyl-2-Propanol and its fluorinated analog 1,1,1,3,3,3-Hexafluoro-2-Phenyl-2-Propanol were investigated for their ability to detect nerve agents such as DCP, its analogs DMMP and HCl along with the explosives mono, di, and trinitrotoluene. …

Fundamental Investigation Of Vesicle Bilayer Membrane Dynamics, Wilson Okumu

Masters Theses

We studied the bilayer of vesicles from dimyristolyphosphatidylcholine (DMPC), using nitrobenzoxadiazole (NBD) probes, attached to the head (NBD-PE) and the tail (NBD-PC) of phospholipid derivatives. We characterized the bilayer as it underwent reversible transition from the gel to the fluid through a phase transition range. The main phase transition was characterized by steady state and timeresolved fluorescence anisotropy, fluorescence intensity decrement and kinetics of dithionite reduction. We also studied DMPC with dihydrocholesterol. Differences between the surface and interior regions of the bilayer region were obtained. The activation barrier was enthalpic in the gel, entropic in the fluid phase and anomalous …

Design Of Multi-Electron Transfer Catalysts For The Reduction Of Trichloroethylene, Christopher Gerard Eman Ciptadjaya

Masters Theses

For decades, organohalide (RX) compounds have been heavily used in the chemical and pharmaceutical industries and in agriculture as pesticides. Improper disposal of organohalides has resulted in their presence in the environment as pollutants, and they have therefore presented serious environmental and toxicological concerns. These organohalides have been associated with various health and environmental problems. Therefore, effective methods for their remediation are required. We have developed a multi-electron transfer (MET) catalyst consisting of flavin mononucleotide anchored to nanocrystalline mesoporous titanium dioxide (TiO₂) thin films, and examined its reactivity toward the organohalide pollutant trichloroethylene (TCE). Various environmental factors were …

On Mathematical Modeling, Nonlinear Properties And Stability Of Secondary Flow In A Dendrite Layer, Daniel N. Riahi

School of Mathematical & Statistical Sciences Faculty Publications

This paper studies instabilities in the flow of melt within a horizontal dendrite layer with deformed upper boundary and in the presence or absence of rotation during the solidification of a binary alloy. In the presence of rotation, it is assumed that the layer is rotating about a vertical axis at a constant angular velocity. Linear and weakly nonlinear stability analyses provide results about various flow features such as the critical mode of convection, neutral stability curve, preferred flow pattern and the solid fraction distribution within the dendrite layer. The preferred shape of the deformed upper boundary of the layer, …

Energy Efficient Removal Of Tds From Ro Reject And Cooling Tower Blowdown, Heath Himstedt, Meredith Bruick, Matthew Correnti, Seth Huber, Pettus Kincannon, Mai Sayarath

Chemical Engineering Undergraduate Honors Theses

The southwestern United States, specifically the Albuquerque, NM area, was chosen as the target location for implementation of the Project ZERO design due to the volume of electronics manufacturing facilities in the area and the critical need to conserve water. The WERC RO reject sample, believed to originate in chemical mechanical polishing, contains high amounts of silica, trace heavy metals, and salt compounds that would negatively impact water quality if it were discharged into surface waters. Because of the high levels of silica, special precaution must be taken when utilizing membrane or mechanical evaporation technologies due to fouling and scaling …

Templated Fabrication Of Large Area Subwavelength Antireflection Gratings On Silicon, Chih-Hung Sun, Wei-Lun Min, Nicholas C. Linn, Peng Jiang, Bin Jiang

Mathematics and Statistics Faculty Publications and Presentations

We report a cheap and scalable bottom-up technique for fabricating wafer-scale, subwavelength-structured antireflection coatings on single-crystalline silicon substrates. Spin-coated monolayer colloidal crystals are utilized as shadow masks to generate metallic nanohole arrays. Inverted pyramid arrays in silicon can then be templated against nanoholes by anisotropic wet etching. The resulting subwavelength gratings greatly suppress specular reflection at normal incidence. The reflection spectra for flat silicon and the templated gratings at long wavelengths agree well with the simulated results using a rigorous coupled wave analysis model. These subwavelength gratings are of great technological importance in crystalline silicon solar cells.

Can Collective Action And Capacity Building Reduce Vulnerability Among Settled Pastoralists?, D. Layne Coppock, Solomon Desta, Getachew Gebru, Seyoum Tezera

Environment and Society Faculty Publications

In 2001 PARIMA and her partners began to create collective-action groups among illiterate, settled pastoralists in southern Ethiopia. These groups—dominated by women—focused on savings-led microfinance, small business, and livestock marketing to increase incomes and diversify livelihoods. Fifty-nine groups with over 2,100 members were formed using intensive capacity- building methods. After six years we wanted to compare group members with their neighbors who never participated in the PARIMA program. We surveyed 180 individuals from groups and paired control (traditional) communities. Respondents were asked to assess the extent that they perceived positive, negative, or no change in their lives over the past …

Diffusion Of Collective-Action Innovations Among Pastoralists In Liben District, Ethiopia, D. Layne Coppock, Solomon Desta, Getachew Gebru, Getachew Kassa, Seyoum Tezera

Environment and Society Faculty Publications

In 2001 PARIMA and her partners began to create collective-action groups among illiterate, settled pastoralists in Ethiopia. These groups—soon dominated by women—focused on savings-led microfinance, small business activity, and livestock marketing to increase incomes and diversify livelihoods. Fifty-nine groups with over 2,100 members were formed using intensive training methods, and they have subsequently merged into legally recognized cooperatives. We regard this approach as successful and sustainable. We were curious, however, if “the word has spread” and collective-action has spontaneously arisen beyond our immediate project area. Preliminary findings from recent surveys of settlements in Liben District indicate that diffusion of collective-action …

Stakeholder Alliance Facilitates Re-Introduction Of Prescribed Fire On The Borana Plateau Of Southern Ethiopia, D. Layne Coppock, Getachew Gebru, Solomon Desta, Lemma Gizachew, Dadhi Amosha, Feyissa Taffa

Environment and Society Faculty Publications

The implementation of a new prescribed fire program to restore bush-encroached rangelands in southern Ethiopia—and hence increase herbaceous forage supplies for livestock—is given as an example of an integrated action involving multiple institutions to address resource-management problems. The resumption of planned fire—traditionally conducted over hundreds of years by pastoralists until the 1970s—was preceded by key activities including mobilization of the pastoral community, review of government proclamations regarding use of fire, interaction with policy makers, capacity building among pastoralists and agency personnel on how to implement and manage planned fires, development of an overall prescribed burn plan, selection of geo-referenced sites, …

Learner-Centered Assignments In Computer Literacy, Martha E. Myers, Meg C. Murray, Mario Guimaraes, Debra B. Geist

Faculty Articles

Literacy is a concept that is understood to be the identifier of an educated populace. In today's world, literacy includes computer literacy, as well as language and quantitative literacy. This paper describes exercises developed to improve first year students' computer literacy through more learner-centered engagement. Exercises are designed to support learner-centered goals of independent and responsible learners, appropriate breadth and depth of content, teacher as facilitator, and assessment woven into learning. Exercise topics include purchase of a personal computer, basic logic via spreadsheets, an annotated bibliography built with electronic resources, and an integrated assignment customized by and for each student.

Investigation Of Radio Frequency Discharges And Langmuir Probe Diagnostic Methods In A Fast Flowing Electronegative Background Gas, Nathaniel P. Lockwood

Theses and Dissertations

Discharges in a flowing background gas are used to produce charged and excited species for numerous applications including etching semiconductors and pumping gas discharge lasers (Pinhero and others, 1998). The effect of a flowing background gas on the charged and excited neutral species generation by an RF discharge in a flow tube and the diagnostics of the resulting plasma with a Langmuir probe have been investigated for pressures between 0.001 to 1 Torr and flow velocities up to 1000 m/s. This investigation was performed using a fluid method coupled to a chemical kinetic model and a hybrid Particle-In-Cell/Monte Carlo Collision …

Collective Action Among Agro-Pastoralists In Baringo District, Kenya: Identifying And Nurturing The Entrepreneurs, D. Layne Coppock, Mark N. Mutinda, Stellamaris K. Muthoka, Abdillahi A. Aboud

Environment and Society Faculty Publications

The rural population of Baringo District in the Rift Valley of north-central Kenya faces numerous challenges including widespread environmental degradation and poverty. The region has endured decades of failed development projects, proliferation of food aid, and has been studied extensively. We have recently undertaken a different approach focused on bottom-up participatory action research and outreach among the Il Chamus and Tugen ethnic communities. The objective is to explore new ways to empower local people via provision of information, novel experiences, and initial access to resources to allow them to envision an alternative future and implement their own activities to better-manage …

Building Effective Community Participation And Stakeholder Partnerships To Promote Positive Change In The Southern Ethiopian Rangelands, D. Layne Coppock, Solomon Desta, Getachew Gebru, Seyoum Tezera, Dadi Amosha

Environment and Society Faculty Publications

Recently there has been increased recognition that authentic community participation and creating strong inter-institutional partnerships are both important in the process of capacity building, generating innovation, and sustaining development achievements in rural Africa. Here we summarize a process of community participation and formation of institutional partnerships in support of pastoral risk-management interventions over the past seven years on the Borana Plateau. Community involvement has been stimulated using Participatory Rural Appraisal (PRA) methods. This has resulted in the proliferation of pastoral collective-action groups that have diversified livelihoods, engaged markets, and improved incomes. Implementing and sustaining positive change, however, has also been …

Report On Nutria Management And Research In The Pacific Northwest, Trevor Sheffels, Mark Sytsma

Center for Lakes and Reservoirs Publications and Presentations

The nutria (Myocastor coypus) is a large semi-aquatic mammal native to South America that has been introduced to numerous countries around the world, primarily for fur farming. Nutria were introduced in Oregon and Washington in the 1930s, and feral populations were documented in 1943. Populations are known to be expanding in both Oregon and Washington, and regional nutria damage and nuisance complaints have increased in recent years. Most of the extensive damage caused by nutria is a direct result of feeding and burrowing, but nutria are also capable of transporting parasites and pathogens transmittable to humans, livestock, and …

An Analysis Of The Environmental Content Of Las Vegas Strip Hotels, Andrew M. Levey

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study examines the environmental content of hotel properties websites. The central question of this study is whether Las Vegas Strip properties have gone green, or plan to go green. Thus, the purpose of this paper is to examine the frequency of the environmental content of twenty-three Las Vegas Strip hotels’ websites as well as five upcoming hotel projects and one hotel expansion project on the Strip. The twenty-eight hotels are all located along Las Vegas Boulevard, also known as the Strip. All properties examined have over two thousand rooms each. The goal is to determine how prevalent and important …

Transmission Scheduling In Sensor Networks Via Directed Edge Coloring, Maggie Xiaioyan Cheng, Li Yin

Computer Science Faculty Research & Creative Works

This paper presents a transmission scheduling scheme in sensor networks. Each node is assigned a list of time slots to use for unicasting and broadcast communication. the algorithm employs edge coloring on a directed graph for transmission scheduling. It is different from previous works that use vertex coloring of a graph for node scheduling, or those that use edge coloring of undirected graphs for link scheduling. the proposed algorithm uses the least number of time slots compared to its counterparts and it avoids both the hidden terminal problem and the exposed terminal problem in both unicast and broadcast communication. ©2007 …

Hunting For Hydrothermal Vents Along The Galápagos Spreading Center, Rachel M. Haymon, Edward T. Baker, Joseph A. Resing, Scott M. White, Ken C. Macdonald

Faculty Publications

No abstract provided.

Evaluation Of Robocode As A Teaching Tool For Computer Programming, Arnold Hensman

Conference Papers

Robocode began as an educational tool to aid in learning Java programming. It has since evolved into something of a phenomenon, as the prospect of creating simple to complex virtual tanks appears to pose an attractive challenge to both novice and expert programmers alike. What started out as a teaching tool has grown into a worldwide network of competitors, all keen to prove that their ‘bot’ stands out from the crowd. Competitions are well organised and many Robocode events are a PR dream for the computing companies that sponsor them. Without a doubt, this easy to use application has sparked …

Large Energy Gaps In Cac₆ From Tunneling Spectroscopy: Possible Evidence Of Strong-Coupling Superconductivity, Cihan Kurter, Lutfi Ozyuzer, Daniel Mazur, John F. Zasadzinski, Daniel Rosenmann

Physics Faculty Research & Creative Works

Tunneling in CaC₆ crystals reproducibly reveals superconducting gaps Δ of 2.3±0.2 meV that are ~40% larger than reported earlier. In an isotropic s -wave scenario, that puts CaC₆ into the class of very strongly coupled superconductors, since 2Δ k Tc ~4.6, implying that soft Ca phonons are primarily involved in the superconductivity. This conclusion explains the relatively large Ca isotope effect found recently for CaC₆, but it could also signal a strong anisotropy in the electron-phonon interaction.

Entrainment And Stimulated Emission Of Ultrasonic Piezoelectric Auto-Oscillators, Richard L. Weaver, Oleg I. Lobkis, Alexey Yamilov

Physics Faculty Research & Creative Works

Theoretical modeling and laboratory tests are conducted for nonlinear auto-oscillating piezoelectric ultrasonic devices coupled to reverberant elastic bodies. the devices are shown to exhibit behavior familiar from the theory of coupled auto-oscillators. in particular, these spontaneously emitting devices adjust their limit-cycle frequency to the spectrum of the body. It is further shown that the auto-oscillations can be entrained by an applied field; an incident wave at a frequency close to the frequency of the natural limit cycle entrains the oscillator. Special attention is paid to the phase of entrainment. Depending on details, the phase is such that the oscillator can …

Characterization Of Metalferroelectric–Insulator–Semiconductor Structures Based On Ferroelectric Langmuir-Blodgett Polyvinylidene Fluoride Copolymer Films For Nondestructive Random Access Memory Applications, Timothy J. Reece

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Ferroelectric field effect transistors (FeFETs) have attracted much attention recently because of their ability to combine high speed, low power consumption, and fast nondestructive readout with the potential for high density nonvolatile memory. The polarization of the ferroelectric is used to switch the channel at the silicon surface between states of high and low conductance.

Among the ferroelectric thin films used in FET devices; the ferroelectric copolymer of Polyvinylidene fluoride, PVDF (C₂H₂F₂), with trifluoroethylene, TrFE (C₂HF₃), has distinct advantages, including low dielectric constant, low processing temperature, low cost and compatibility …

Reinterpreting The Pollen Data From Dos Cabezas, Karl J. Reinhard, Vaughn M. Bryant, Sheila D. Vinton

School of Natural Resources: Faculty Publications

The published pollen analysis of the Dos Cabezas giants, Geyer et al. (2003), lists variety of purported dietary pollen types. The paper also hypothesises that the giants were poisoned with plant toxins. We have severe reservations about the pollen evidence of diet and poisoning. We suggest that the analysts made several errors in their interpretation. Firstly, some of the discovered pollen types are not prehistoric endemics to the Dos Cabezas region of coastal Peru. These include the pollen of fava beans (cultivated in the Old World), and specified species of agave and sage. We believe that some or all of …

Diagnosis Of The July 6, 2002 Ogallala, Nebraska Flash Flood, David B. Radell, Mark R. Anderson, John W. Stoppkotte, James R. Mccormick

Department of Earth and Atmospheric Sciences: Faculty Publications

During the early morning hours of 6 July 2002, a mesoscale convective system (MCS) traversed southwestern Nebraska and produced more than 40 cm of precipitation, resulting in a flash flood that closed Interstate 80 and caused one fatality near Ogallala, Nebraska. Regional climatology yields that this flash flood ranked first in precipitation amount for a 24 hour period over the past one hundred years. Synoptic and mesoscale features similar to other flash flooding events and conducive to extremely heavy precipitation were in place over the Central Plains, including a weak upper level ridge, high precipitable water values (180% of normal), …

The Webt Campaign On The Blazar 3c 279 In 2006, Markus Böttcher, Jeff W. Robertson, Stéphane Vennes

Aerospace, Physics, and Space Science Faculty Publications

The quasar 3C 279 was the target of an extensive multiwavelength monitoring campaign from 2006 January through April. An optical-IR-radio monitoring campaign by the Whole Earth Blazar Telescope (WEBT) collaboration was organized around target-of-opportunity X-ray and soft γ-ray observations with Chandra and INTEGRAL in 2006 mid-January, with additional X-ray coverage by RXTE and Swift XRT. In this paper we focus on the results of the WEBT campaign. The source exhibited substantial variability of optical flux and spectral shape, with a characteristic timescale of a few days. The variability patterns throughout the optical BVRI bands were very closely correlated with each …

Sybil Attack Detection In A Hierarchical Sensor Network, Jian Yin, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

The Sybil attack is a particularly harmful threat to sensor networks where a single sensor node illegitimately claims multiple identities. a malicious node may generate an arbitrary number of additional node identities using only one physical device. the Sybil attack can disrupt normal functioning of the sensor network, such as the multipath routing, used to explore the multiple disjoint paths between source-destination pairs. But the Sybil attack can disrupt it when a single adversary presents multiple identities, which appear on the multiple paths. Digital certificates are a way to prove identities, but they are not suitable for the sensor network …

Nanomaterial Composites For The Detection Of Nerve Gas Analogs, Yogesh Datar

Masters Theses

The basis of the research work described here is the use of nanocomposite materials built by bottom-up approach for the selective detection of nerve gas analogs. Nanocomposites materials constructed by using nanoparticle-monomer-receptor (NMR) concept have been utilized to detect nerve gas analogs DCP and DMMP. Synthetic approach used in the construction of nanosensors involved use of robust platforms such as silica nanoparticles and fluorescent quantum dots. Highly conjugated receptor molecules were synthesized by using stilbeneoid compounds. A complete opto-nanosensor was developed by anchoring highly conjugated receptor molecules onto the silica nanoparticles as well as onto the quantum dots. The opto-nanosensors …

Estimating Sea Level Due To Crustal Stretching In The Margin Of The Indian Ocean, Kisa Mwakanyamale

Masters Theses

Continental crust extension is a precursor to the formation of a new ocean. The overall crustal extension causes change in the volume of global oceans hence change in sea level. The break-up of Gondwana that began during Late Triassic to Early Jurassic time caused continental crustal extension prior to forming the Indian Ocean. Extension started 184 Ma with rifting between SE Africa, Madagascar and Antarctica. This was followed by rifting between Greater India, Australia and Antarctica beginning about 160 Ma. The most recent episode of extension occurred 34 Ma involving separation between Arabia and Horn of Africa. Gridded data sets …

Lsuhsc Facilities Daily Update: December 2007, Lsuhsc Property And Facilities Management

LSUHSC Facilities Daily Updates: 2007

LSUHSC Facilities Daily Updates from December 2007.

These updates describe damage and a timeline of repairs at the LSU Health Sciences Center - New Orleans campus due to Hurricane Katrina which made landfall August 29, 2005.

Lsuhsc Facilities Biweekly Update: December 2007, Lsuhsc Property And Facilities Management

LSUHSC Facilities Biweekly Updates: 2007

LSUHSC Facilities Biweekly Updates from December 7 and 21, 2006.

These updates describe damage and a timeline of repairs at the LSU Health Sciences Center - New Orleans campus due to Hurricane Katrina which made landfall August 29, 2005.

The Slider-Pinning Problem, Audrey Lee, Ileana Streinu, Louis Theran

Computer Science: Faculty Publications

A Laman mechanism is a flexible planar bar-and-joint framework with m ≤ 2n-3 edges and exactly k = 2n-m degrees of freedom. The slider-pinning problem is to eliminate all the degrees of freedom of a Laman mechanism, in an optimal fashion, by individually fixing x or y coordinates of vertices. We describe two easy to implement O(n2) time algorithms.