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Physical Sciences and Mathematics Commons

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Marshall University

2007

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Articles 1 - 15 of 15

Full-Text Articles in Physical Sciences and Mathematics

Fabrication Of Robust Superconducting Granular Aluminium/Palladium Bilayer Microbolometers With Sub-Nanosecond Response, Thomas E. Wilson Dec 2007

Fabrication Of Robust Superconducting Granular Aluminium/Palladium Bilayer Microbolometers With Sub-Nanosecond Response, Thomas E. Wilson

Physics Faculty Research

We provide a convenient recipe for fabricating reliable superconducting microbolometers as acoustic phonon detectors with sub-nanosecond response, using imagereversal optical lithography and dc-magnetron sputtering, and our recipe requires no chemical or plasma etching. Our approach solves the traditional problem for granular aluminium bolometers of unreliable (i.e., non-Ohmic) electrical contacts by sequentially sputtering the granular aluminium film and then a palladium capping layer. We use dc calibration data, the method of Danilchenko et al. [1], and direct nanosecond-pulsed photoexcitation to obtain the microbolometer’s characteristic current, thermal conductance, characteristic relaxation time, and heat capacity. We also demonstrate the use of the deconvolution …


A Statistical Model To Forecast Short-Term Atlantic Hurricane Intensity, Kevin Law, Jay S. Hobgood Oct 2007

A Statistical Model To Forecast Short-Term Atlantic Hurricane Intensity, Kevin Law, Jay S. Hobgood

Geography Faculty Research

An alternative 24-h statistical hurricane intensity model is presented and verified for 13 hurricanes during the 2004–05 seasons. The model uses a new method involving a discriminant function analysis (DFA) to select from a collection of multiple regression equations. These equations were developed to predict the future 24-h wind speed increase and the 24-h pressure drop that were constructed from a dataset of 103 hurricanes from 1988 to 2003 that utilized 25 predictors of rapid intensification. The accuracy of the 24-h wind speed increase models was tested and compared with the official National Hurricane Center (NHC) 24-h intensity forecasts, which …


The Fabrication And Characterization Of Granular Aluminium/Palladium Bilayer Microbolometers, Thomas E. Wilson Jul 2007

The Fabrication And Characterization Of Granular Aluminium/Palladium Bilayer Microbolometers, Thomas E. Wilson

Physics Faculty Research

Superconducting granular aluminium/palladium bilayer microbolometers with subnanosecond response can be easily fabricated using an all lift-off process with image-reversal lithography. The palladium capping layer allows for convenient and reproducible Ohmic contacts to be made to the device. We report their fabrication, resistance–current calibration, responsivity and response time. Finally, a deconvolution algorithm is used to improve the time resolution to approximately 1 ns while obtaining the incident photon and phonon fluxes in both direct photoexcitation and phonon heat pulse experiments.


A Variational Principle For Discontinuous Potentials, Anna Mummert Apr 2007

A Variational Principle For Discontinuous Potentials, Anna Mummert

Mathematics Faculty Research

Let $X$ be a compact space, $f\colon X \to X$ a continuous map, and $\Lambda \subset X$ be any $f$-invariant subset. Assume that there exists a nested family of subsets $\{\Lambda_l\}_{l \geq 1}$ that exhaust $\Lambda$, that is $\Lambda_l \subset\Lambda_{l+1}$ and $\Lambda =\bigcup_{l \geq 1} \Lambda_l$. Assume that the potential $\varphi \colon X \to \mathbb{R}$ is continuous on the closure of each $\Lambda_l$ but not necessarily continuous on $\Lambda$. We define the topological pressure of $\varphi$ on $\Lambda$. This definition is shown to have a corresponding variational principle. We apply the topological pressure and variational principle to systems with non-zero …


Accessibility Of Home Blood Pressure Monitors For Blind And Visually Impaired People, Mark M. Uslan, Darren M. Burton, Thomas E. Wilson, Steven Taylor, Bruce S. Chertow, Jack E. Terry Mar 2007

Accessibility Of Home Blood Pressure Monitors For Blind And Visually Impaired People, Mark M. Uslan, Darren M. Burton, Thomas E. Wilson, Steven Taylor, Bruce S. Chertow, Jack E. Terry

Physics Faculty Research

Background: The prevalence of hypertension comorbid with diabetes is a significant health care issue. Use of the home blood pressure monitor (HBPM) for aiding in the control of hypertension is noteworthy because of benefits that accrue from following a home measurement regimen. To be usable by blind and visually impaired patients, HBPMs must have speech output to convey all screen information, an easily readable visual display, identifiable controls that are easy to use, and an accessible user manual.

Methods: Data on the physical aspects and the features and functions of nine Food and Drug Administration-approved HBPMs (eight of which were …


The Evolution Of Zinjanthropus Boisei, Paul J. Constantino, Bernard A. Wood Mar 2007

The Evolution Of Zinjanthropus Boisei, Paul J. Constantino, Bernard A. Wood

Biological Sciences Faculty Research

Many people assume that OH 5, the type specimen of Paranthropus boisei, collected in 1959, was the first evidence of that taxon to be found, but OH 3, recovered in 1955, predated the discovery of OH 5 by four years. Thus, Paranthropus boisei recently celebrated the equivalent of its fiftieth birthday. This review marks that milestone by examining the way our understanding of this taxon has changed during its fifty, or so, year history.


Synthesis And X-Ray Crystal Structure Of [(C5ph5)Crcl(Μ-Cl)2tl]2: An Example Of The Rare M-X-Tli Linkage (X = Halide), K. Brian Davis, T. David Harris, Michael Castellani, James A. Golen, Arnold L. Rheingold Jan 2007

Synthesis And X-Ray Crystal Structure Of [(C5ph5)Crcl(Μ-Cl)2tl]2: An Example Of The Rare M-X-Tli Linkage (X = Halide), K. Brian Davis, T. David Harris, Michael Castellani, James A. Golen, Arnold L. Rheingold

Chemistry Faculty Research

Reaction of solid TlCl with [(C5Ph5)CrCl(m-Cl)]2 in CH2Cl2 solvent yields the monomeric complex (C5Ph5)CrCl(m-Cl)2Tl in 80% isolated yield. The C5H5 and C5Me5 analogues do not react with TlCl suggesting a steric basis for the reaction of the C5Ph5 material. An X-ray crystal structure of [(C5Ph5)CrCl(m-Cl)2Tl]2•2CH2Cl2 was obtained.


Acquiring Three-Dimensional Data From Small Mammalian Teeth : Laser Scanning Eocene Marsupials, Nicholas E. Smith Jan 2007

Acquiring Three-Dimensional Data From Small Mammalian Teeth : Laser Scanning Eocene Marsupials, Nicholas E. Smith

Theses, Dissertations and Capstones

Three-dimensional laser scanning is an effective method of digitization in paleontology, but has traditionally been restricted to larger specimens. The goal of this study was to develop a laser scanning technique applicable to small mammalian (< 5 mm) dentition. Modeling protocols were developed, and a morphometric error study showed the system highly accurate (percent error = 1D- 0.4%, 2D- 0.05%, 3D- 1.74%). Automation and standardization were accomplished by implementation of a multiscan platform and autosurfacing macro reducing modeling time by 60%. To highlight one morphometric application, 3D models (n=61) of three sympatric Eocene marsupials were digitized, and traditionally qualitative diagnostic characters were quantified and assessed. All but two of the 19 characters examined proved diagnostic (p < 0.05), and exploratory canonical discriminant analysis confirmed three distinct species. Incorporating type specimens revealed a familial overlap, therefore, this novel modeling technique can be employed in a full revision of early Eocene marsupials.


Population Modeling By Differential Equations, Hui Luo Jan 2007

Population Modeling By Differential Equations, Hui Luo

Theses, Dissertations and Capstones

A general model for the population of Tibetan antelope is constructed. The present model shows that the given data is reasonably logistic. From this model the extinction of antelopes in China is predicted if we don’t consider the effects of humans on the population. Moreover, this model shows that the population is limited. A projected limiting number is given by this model. Some typical mathematical models are introduced such as exponential model and logistic model. The solutions of those models are analyzed.


Atmospheric Smog Modeling, Using Eos Satellite Aster Image Sensor, With Feature Extraction For Pattern Recognition Techniques And Its Correlation With In-Situ Ground Sensor Data, Parthasarathi Roy Jan 2007

Atmospheric Smog Modeling, Using Eos Satellite Aster Image Sensor, With Feature Extraction For Pattern Recognition Techniques And Its Correlation With In-Situ Ground Sensor Data, Parthasarathi Roy

Theses, Dissertations and Capstones

Atmospheric pollution was previously considered as a 'Brown Cloud’ phenomenon restricted to industrialized urban regions. Studies in field stations and satellite observations made since the last decade revealed that it now spans continents and ocean basins world wide. The objective of this research investigation is to assess atmospheric pollutants in the troposphere and their spectral characteristic signatures by using highspectral and spatial resolution Earth Observation System (EOS) satellite imaging sensor Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and to find correlations with ground sensor observations. Ground sensor data are imported into a geodatabase for spatial reference. Raw ASTER …


Environmental Disturbance And The Distribution Of Rhinichthys Bowersi In West Virginia, Brooke Elizabeth Schlenker Jan 2007

Environmental Disturbance And The Distribution Of Rhinichthys Bowersi In West Virginia, Brooke Elizabeth Schlenker

Theses, Dissertations and Capstones

The Cheat minnow, Rhinichthys bowersi, has been designated a species of concern by the West Virginia Department of Natural Resources. Mitochondrial DNA analysis (Gladwell 2002) supports the origin of R. bowersi from hybridization between cyprinids R. cataractae and Nocomis micropogon. Previous investigators have hypothesized a relationship between fish hybridization and environmental disturbance. The habitat of R. bowersi has experienced severe environmental degradation from mineral and timber extraction. In this study, environmental quality was compared between stream systems in which parental species of R. bowersi were found with and without resulting hybridization. Environmental quality indicators included biotic diversity and stream structure …


Impact Of The 25th Street Combined Sewer Overflow On The Ohio River, Travis M. Bailey Jan 2007

Impact Of The 25th Street Combined Sewer Overflow On The Ohio River, Travis M. Bailey

Theses, Dissertations and Capstones

The 25th Street Combined Sewer Overflow was analyzed for total coliforms, Escherichia coli, antibiotic-resistant coliforms and E. coli, and routine water chemistry. The objectives of this study were to enumerate antibiotic resistant bacteria near a CSO, determine the impact of a small quantity CSO on Ohio River water quality during a storm event, and to correlate antibiotic resistance with conventional water quality measurements. The data indicate that resistant bacteria exist in both river water and wastewater, and that this CSO can not be identified as a source of resistant strains. Rain events do cause a detectable and transient change in …


Satellite Image Processing For Biodiversity Conservation And Environmental Modeling In Kyrgyz Republic National Park, Galina N. Fet Jan 2007

Satellite Image Processing For Biodiversity Conservation And Environmental Modeling In Kyrgyz Republic National Park, Galina N. Fet

Theses, Dissertations and Capstones

There is a need for extensive surveys of living organisms at a global scale; digital data exchange and storage is an essential part of such studies. Biodiversity inventory of fungi, which play an essential role in the health of the mountainous conifer forests of a developing country – Kyrgyz Republic, was linked to the vegetation classification produced from the high-resolution satellite imagery. Terra ASTER and SRTM90 imagery was used as a base map for the ecosystem modeling of the species and habitat distribution and for the three-dimensional representation, especially valuable for the mountainous landscapes of the Ala Archa National Park. …


Arsenic Toxicity In Plhc-1 Cell Line And The Distribution Of Arsenic In Central Appalachia, Yeong Nam Jeong Jan 2007

Arsenic Toxicity In Plhc-1 Cell Line And The Distribution Of Arsenic In Central Appalachia, Yeong Nam Jeong

Theses, Dissertations and Capstones

Our ecosystem has geobiophysical relationships. Environmental pollution can lead to immediate consequences like organism death or lack of reproduction. It can also lead to long-range consequences through mutations and DNA damage. Fish can be affected very directly by environmental contamination in water but the study of fish is not performed well. We are developing a quantitative assay to assess DNA damage in vitro due to heavy metal contamination using a tissue culture line of Poeciliopsis lucida, the desert pupfish, which is used for other toxicology assays. To detect DNA damage, Single Cell Gel Electrophoresis (Comet Assay) is very useful. …


Contact Printed Co/Insulator/Co Molecular Junctions, Xiaojuan Fan, David L. Rogow, Claudia H. Swanson, Akhilesh Tripathi, Scott R. J. Oliver Jan 2007

Contact Printed Co/Insulator/Co Molecular Junctions, Xiaojuan Fan, David L. Rogow, Claudia H. Swanson, Akhilesh Tripathi, Scott R. J. Oliver

Physics Faculty Research

The authors report the contact printing of a Au/Co double layer (total thickness ∼20–40nm) onto a self-assembled monolayer surface to form molecular junctions under ambient conditions. The feature size ranges from 50×50μm2 to 2×2 mm2. Grazing incident x-ray diffraction of the multilayer junction shows all expected Au peaks, while elemental Co was confirmed by energy dispersive spectroscopy. Film thickness, roughness, and density were characterized by x-ray reflectivity. I-V measurements show a prominent hysteresis, likely associated with charge trapping at the metal-organic interface, not an intrinsic feature of alkanedithiol molecules.