Physical Sciences and Mathematics Commons^™

Extreme Rainfall In Texas: Patterns And Predictability, John W. Nielsen-Gammon, Fuqing Zhang, Andrew M. Odins, Boksoon Myoung

Mathematics, Physics, and Computer Science Faculty Articles and Research

Extreme rainfall, with storm total precipitation exceeding 500 mm, occurs several times per decade in Texas. According to a compositing analysis, the large-scale weather patterns associated with extreme rainfall events involve a northward deflection of the tropical trade winds into Texas, with deep southerly winds extending into the middle troposphere. One such event, the July 2002 South-Central Texas flood, is examined in detail. This particular event was associated with a stationary upper-level trough over central Texas and northern Mexico that established a steady influx of tropical moisture from the south. While the onset of the event was triggered by destabilization …

Coffee To Go! Modeling Thermoclines In Multivariable Calculus, Andrea Bruder, Brynja R. Kohler

Mathematics and Statistics Faculty Publications

While mathematical modeling is an integral process in applied mathematics, students rarely encounter genuine modeling opportunities in their calculus courses. Here we introduce a laboratory experience as a natural starting point for calculus students to investigate multivariable functions. A layered system of coffee and milk serves as a physical model for temperature gradients in lakes or the atmosphere, where temperature depends on both a temporal and spatial variable. Students create, observe, and collect temperature data of their own, graph the data, and develop mathematical models to fit the data. We require students to write a report about their findings. This …

Electrical Properites Of Superconducting Cross - (Nano) Whiskers Junction, Serdar Altin, Eyüphan Yakinci, Yakup Balci, M. Ali̇ Aksan

Turkish Journal of Physics

Bi-2212 superconducting single crystal (nano) whiskers have been fabricated by annealing a melt-quenched (glass) Bi_3Sr_2Ca_2Cu_3O_x precursor. A couple of (nano) Whiskers obtained were placed crosswise on a YSZ single crystal substrate and then heat treated at 830 C for 25 minute to form nano-scale junction. The T_c of each nano-whisker was found to be 85 K and the critical current density, J_c, of the whiskers was calculated to be 1177 Acm^{-2} at zero field. The I-V characteristics of the nano-junction at 30 K were found to show a multiple-branch structure, which is the main behavior of the Josephson junction.

Team Process Review Of The Accelerated Urban Initiative: Toledo Public Schools, Kevin O'Brien, Claudette Robey, Larry C. Ledebur, Billie K. Geyer, K. Toth, Michael Mcgoun

All Maxine Goodman Levin School of Urban Affairs Publications

No abstract provided.

Pesticides, People, And The Environment: A Complex Relationship, Roxanne Greitz Miller

Education Faculty Articles and Research

The writer provides information on pesticides, the controversies surrounding their use, and pesticide safety.

The Evolution Of A Warm Season Severe Eastern Kentucky Flash Flood, C. Henry, R. Mahmood, C. Smallcomb, M. Mclane, D. Champlin

School of Natural Resources: Faculty Publications

No abstract provided.

Level And Source Of Supplemental Selenium For Beef Steers, Scott Fry, Elizabeth B. Kegley, M. Ellen Davis, Michael D. Ratcliff, Douglas L. Galloway, Ron A. Dvorak

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Selenium (Se) is deficient in many Arkansas soils; therefore, an experiment was conducted on steers to evaluate the effects of two supplemental Se sources on performance, blood metabolites, and immune function. Thirty Angus-crossbred steers were blocked by weight and assigned within block to one of 15 pens (two steers/pen). Pens were assigned randomly within blocks to one of three dietary treatments consisting of a corn-soybean meal supplement devoid of supplemental Se (negative control, NC) or corn-soybean meal supplements providing 1.7 mg supplemental Se/d as sodium selenite (inorganic Se, ISe) or as Se yeast (organic Se, OSe). Steers were offered fescue …

Effects Of Food Sources And Culture Conditions On Feeding Behaviour And Growth Rates Of Nile Tilapia Fry (Oreochromis Niloticus), Latifa Juma Rashid Al-Shamsi

Theses

The importance of fish aquaculture in general as an alternative source of animal protein, is raised during this century after the significant reduction of natural marine resources. Such reduction has increased the interest of many countries as well as international agencies in worldwide food security, especially for developing countries. The success of any aquaculture is chiefly judged by its economic development, which always depends on the management of producing acceptable marketing size and weight of fish in short time. In the last few decades, many aquacultures failed in balancing between the financial input and the resultant income. That is due …

Planetary Transits Of The Trans-Atlantic Exoplanet Survey- Candidate Tres-1b, Aaron Price, Ron Bissinger, Gregory P. Laughlin, Bruce L. Gary, Tonny Vanmunster, Arne A. Henden, Donn Ray Starkey, Daniel H. Kaiser, Jon A. Holtzman, Laurence A. Marschall, Thomas Michalik, T. Wellington, Pertti Paakkonen, Zsolt Kereszty, Russ Durkee, Kent Richardson, Robin Leadbeater, Timothy P. Castellano

Physics and Astronomy Faculty Publications

The AAVSO compiled 10,560 CCD observations of the suspected exoplanet transit object TrES-1b covering seven complete transit windows, three windows of partial coverage, and coverage of baseline non-transit periods. Visual inspection of the light curves reveals the presence of slight humps at the egress points of some transits. A boot strap Monte Carlo simulation was applied to the data to confirm that the humps exist to a statistically significant degree. However, it does not rule out systemic effects which will be tested with campaigns in the 2005 observing season.

Characterization And Design Of A Molecular Imprinted Polymer For Cinchona Alkaloids, William P. Fish

Seton Hall University Dissertations and Theses (ETDs)

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Reaction Of Organosilicon Hydrides With Inorganic Surfaces: An Example Of Surface Catalyzed Self-Assembly And Water Porosimetry: A New Technique To Characterize Hydrophobic Porous Surfaces And Wetting In Nano-Confinement, Roy Helmy

Seton Hall University Dissertations and Theses (ETDs)

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Thorium-Based Thin Films As Highly Reflective Mirrors In The Euv, David D. Allred, William R. Evans, Jed E. Johnson, Richard L. Sandberg, R. Steven Turley

Faculty Publications

As applications for extreme ultraviolet (EUV) radiation have been identified, the demand for better optics has also increased. Thorium and thorium oxide thin films (19 to 61 nm thick) were RF-sputtered and characterized using atomic force microscopy (AFM), spectroscopic ellipsometry, low-angle x-ray diffraction (LAXRD), x-ray photoelectron spectroscopy (XPS), and x-ray absorption near edge structure (XANES) in order to assess their capability as EUV reflectors. Their reflectance and absorption at different energies were also measured and analyzed at the Advanced Light Source in Berkeley. The reflectance of oxidized thorium is reported between 2 and 32 nm at 5, 10, and 15 …

Prioritization Methods For Accelerating Mdp Solvers, Kevin Seppi, David Wingate

Faculty Publications

The performance of value and policy iteration can be dramatically improved by eliminating redundant or useless backups, and by backing up states in the right order. We study several methods designed to accelerate these iterative solvers, including prioritization, partitioning, and variable reordering. We generate a family of algorithms by combining several of the methods discussed, and present extensive empirical evidence demonstrating that performance can improve by several orders of magnitude for many problems, while preserving accuracy and convergence guarantees.

Autonomous Vehicle Technologies For Small Fixed-Wing Uavs, Randal Beard, Derek Kingston, Morgan Quigley, Deryl Snyder, Reed Christiansen, Walt Johnson, Timothy Mclain, Michael A. Goodrich

Faculty Publications

The objective of this paper is to describe the design and implementation of a small semi-autonomous fixed-wing unmanned air vehicle. In particular we describe the hardware and software architectures used in the design. We also describe a low weight, low cost autopilot developed at Brigham Young University and the algorithms associated with the autopilot. Novel PDA and voice interfaces to the UAV are described. In addition, we overview our approach to real-time path planning, trajectory generation, and trajectory tracking. The paper is augmented with movie files that demonstrate the functionality of the UAV and its control software.

Evolution Of A Late Cenozoic Supradetachment Basin Above A Flat-On-Flat Detachment With A Folded Lateral Ramp, Se Idaho, A. N. Steely, Susanne U. Janecke, S. P. Long, S. C. Carney, R. Q. Oaks Jr., V. E. Langenheim, P. K. Link

Susanne U. Janecke

Uplift and exposure of the Bannock detachment system and the synextensionalbasin fi ll deposits of the Salt Lake Formation provide a unique exposure of the threedimensionalgeometries of a low-angle normal fault system and the stratal architectureof the overlying supradetachment basin. Within this system, structural andstratigraphic analyses, outcrop patterns, tephra geochronology, and geological crosssections document several important relationships: (1) the Bannock detachment systemdeveloped above the Sevier-age Cache-Pocatello culmination and resembles theSevier Desert detachment in its geometry, structural setting, and kinematic evolution;(2) the Bannock detachment system initiated and slipped at low angles; (3) fl aton-fl at, ramp-fl at, and lateral ramp geometries, …

Characterisation Of An Acrylamide-Based Photopolymer For Holographic Data Storage, Hosam Sherif

Masters

An acrylamide-based photopolymer, formulated in the Centre for Industrial and Engineering Optics, was investigated as a recording material for holographic data storage applications. Holographic data storage (HDS) is an optical storage technique, which theoretically allows densities as high as tens of TB/cm2 with data transfer rates of many GB/s/. HDS has unique advantages, such as the ability to perform parallel data searches (associative recall) and implement novel encryption techniques. At present, many materials have been investigated to determine their suitability for use as HDS media. As yet, no one material possesses all the properties that are required to realise the …

An Investigation Of The Effect Of Variation In Surface Electrode Type And Placement On Action Potentials Elicited By Peripheral Nerve Simulation, Jacinta Augustine

Masters

Several experiments were designed and carried out in order to compare the performances of five commercially available EMG surface electrodes. The aim was to identify the optimal surface recording electrode from the samples examined. The particular interest was to assess the comparative performance of the electrodes routinely used in our hospital Neurophysiology laboratory. It is envisaged that the conclusions from the study might be applied to improve the quality and reproducibility of nerve conduction techniques use din our department. A literature survey was carried out to identify some of the factors that influence the recording of evoked potentials from peripheral …

Characterization Of The Mechanisms By Which The Organophosphorus Compound Malathion Induces Apoptosis In L929 Murine Fibroblasts, Laila Masoud Ali Al-Alawi

Theses

While acute organophosphorous compound poisoning due to inhibition of acetylcholinesterase is a well-established clinical entity, the existence of chronic poisoning due to exposure to low levels of organophosphorous compounds (below the threshold required for cholinergic clinical symptoms) is a hotly debated issue. In this study, we have evaluated the effects of noncholinergic doses of malathion (0.01-20 µM) on apoptosis of murine L929 fibroblasts. Employing flow cytometric and caspase activation analyses, we demonstrate that malathion induces apoptosis in L929 cells in a dose- and time-dependent manner. The initiator caspases (caspase-8 and caspase-9) as well as the effector caspase (caspase-3) were activated …

Effect Of Anti-Oxidants On Endocrine And Metabolic Parameters Of Diabetic Rats, Maryam Suroor Al Shamsi

Theses

Diabetes mellitus is recognized as one of the leading causes of morbidity and mortality in the world. About 5 to 6% of the world population suffers from this disease and the number of people diagnosed with diabetes is rapidly increasing. Diabetes has been demonstrated to be associated with oxidative stress and hyperglycemia, one of the most important indictors of oxidative stress. Normally the endogenous mechanisms of enzymes and antioxidants are able to destroy the reactive species and create a balance between antioxidant and free radicals. In diabetes, the oxidative stress is increased due to the deficiency in the antioxidant defense. …

Fine Mapping Of Sequences Important For Fiv Rna Packaging And Their Mechanism Of Function, Akela Ahmed Mohamed Ghazawi

Theses

The mechanism by which retroviruses preferentially encapsidate their unspliced genomic RNA among millions of both spliced viral and cellular mRNAs in the cytoplasm represents a function of great specificity. This selection process requires that the genomic RNA contain packaging determinants unique to its own RNA that can interact specifically with the packaging proteins of the viral particles, the Gag polyproteins. Knowing the exact sequences involved in packaging should provide basic insights into the mechanism of preferentially encapsidating the full length genomic RNA.

We have been interested in mapping the packaging determinants of the feline immunodeficiency virus (FIV), a lentivirus that …

"An Investigation Into The Potential Of Immobilized Nitrifies In Wastewater Treatment", Ahmed S. Embaby

Theses

Removal of ammonia from wastewater is one of the problematic issues in wastewater treatment because nitrifies are very slow growing and can be washed out from activated sludge processes. There is a need to use higher advanced techniques to retain biomass. Among these techniques is cell immobilization in appropriate reactor environments. Cell immobilization technology can be approached by various methods, including cell entrapment or biofilms. However, these immobilization techniques are often accompanied by challenges in terms of biomass activity preservation and recovery following the immobilization treatment, reduction of nutrients mass transfer rates, adequate performance under shock situations and preservation of …

Effect Of Some Medicinal Plants In U.A.E. On Glucose Homeostasis In Rats, Fatma Khadem Al-Ghaithi

Theses

Diabetes mellitus is one of the most common endocrine diseases in the world that affects almost 6% of the world population. The treatment of diabetes mellitus takes three main forms. First, diet and exercise. Secondly, insulin therapy, and thirdly, using hypoglycaemic agents (suiphonylureas and biguanides). Many of these agents are not very effective in lowering glucose level in diabetic patients and are either too expensive or have undesirable side effects and contraindications. As a result of this, the search for effective drugs for the treatment of diabetes mellitus continues.

Before the introduction of insulin in 1922, the treatment of diabetes …

Morphological And Physiological Abnormalities In Tissue Culture-Derived Date Palm (Phoenix Dactylifera L.) Plants, Hamad Saif Al-Mazroui

Theses

The UAE attaches great importance to agricultural development with a sound focus on date palms. This special attention is obvious in the ongoing expansion of agricultural resources and investments, the growing number of palm trees, and in the extensive use of modern technologies. Mass cultivation of date palm trees is required to continue according to the country's agricultural plans.

In order to achieve these agricultural expansion of date palm, new techniques of propagation other than traditional techniques (seed and offshoot propagation) are critically required. Tissue culture is a modern and reliable technology being one of the main methods for date …

Salmonella Infection Among Farm Animals In Al Ain, United Arab Emirates., Dalal Saeed Saeed Mansour Al Kaabi

Theses

Salmonellosis is considered one of the most economically significant diseases, affecting man and different animals. The disease affects all ages of domesticated and wild living animals. Salmonellosis manifests a variety of clinical signs such as diarrhea, abortion, arthritis and respiratory problems. The natural habitat of Salmonella species is the intestinal tract of most animal species. Carrier animals represent a continuous source of shedding the bacteria in the surrounding environment. Salmonella infection among animals and then to man causing public health hazard.

In this study, a total of 882 samples were collected from different animal species in Al Ain area of …

Optimal Selection Of The Desalination Intakes And Outlets Considering The Environmental And Hydrodynamic Conditions Prevailing In The Uae Western Coastal Water, Ahmed Ali Basioni

Theses

No abstract provided.

Nearly-Free-Electron Gas In A Silicon Cage, J. Ulises Reveles, Shiv N. Khanna

Physics Publications

A systematic study of the ground state geometries, electronic structure, and stability of the metal (M) encapsulated MSi12 (M=Sc, Ti, V, Cr, Mn, Fe, Co, Ni) clusters has been carried out within a gradient-corrected density functional formalism. It is shown that the ground state of most MSi12 clusters has the lowest spin multiplicity as opposed to the high spin multiplicity in free transition metal atoms. Consequently, a proper inclusion of the spin conservation rules is needed to understand the variation of the binding energy of M to Si12 clusters. Using such rules, CrSi12 and FeSi12 are found to exhibit the …

Electroreflectance Spectroscopy In Self-Assembled Quantum Dots: Lens Symmetry, A. H. Rodríguez, C. Trallero-Giner, Martín Muñoz, María C. Tamargo

Physics Publications

Modulated electroreflectance spectroscopy ΔR∕R of semiconductor self-assembled quantum dots is investigated. The structure is modeled as dots with lens shape geometry and circular cross section. A microscopic description of the electroreflectance spectrum and optical response in terms of an external electric field (F) and lens geometry have been considered. The field and lens symmetry dependence of all experimental parameters involved in the ΔR∕Rspectrum have been considered. Using the effective mass formalism the energies and the electronic states as a function of F and dot parameters are calculated. Also, in the framework of the strongly confined regime general expressions for the …

Electroreflectance Spectroscopy In Self-Assembled Quantum Dots: Lens Symmetry, A. H. Rodríguez, C. Trallero-Giner, Martín Muñoz, María C. Tamargo

Physics Publications

Modulated electroreflectance spectroscopy Delta R/R of semiconductor self-assembled quantum dots is investigated. The structure is modeled as dots with lens shape geometry and circular cross section. A microscopic description of the electroreflectance spectrum and optical response in terms of an external electric field (F) and lens geometry have been considered. The field and lens symmetry dependence of all experimental parameters involved in the Delta R/R spectrum have been considered. Using the effective mass formalism the energies and the electronic states as a function of F and dot parameters are calculated. Also, in the framework of the strongly confined regime general …

Structural Growth In Iron Oxide Clusters: Rings, Towers, And Hollow Drums, N. O. Jones, B. V. Reddy, F. Rasouli, Shiv N. Khanna

Physics Publications

It is shown that the transition from an elementary FeO molecule to the bulk rock-salt FeO proceeds via hollow rings, towers, and drums. Our first-principles electronic structure calculations carried out within a gradient-corrected density functional framework show that small FenOn (n=2,3,4,5) clusters form single, highly stable rings. Starting at Fe6O6, these elementary rings begin to assemble into nano columnar structures to form stable Fe6O6, Fe7O7, Fe8O8, Fe9O9, Fe10O10, and Fe12O12 towers. The rings and the empty towers can be further stabilized by capping O atoms at the ends, leading to FenOn+1 and FenOn+2 sequences. The theoretical results provide insight into …

Role Of Titanium In Hydrogen Desorption In Crystalline Sodium Alanate, C. Moysés Araújo, Rajeev Ahuja, J. M. Osorio Guillén, Puru Jena

Physics Publications

The role of Ti in improving the thermodynamics of hydrogen desorption in crystalline sodium alanate (NaAlH4) has been investigated by using the density functional theory. The total energy calculations reveal that Ti prefers to occupy the Na site over that of the Al site when the atomic energies are used as the reference. However, the use of the cohesive energies of Al,Na, and Ti leads to the Al site being the least unfavorable one. Irrespective of whether Ti occupies the Na or the Al site, the energy necessary to remove a hydrogen atom from Ti substituted sodium alanate is significantly …