Physical Sciences and Mathematics Commons^™

Editorial Board & Iowa Academy Of Science Officers And Directors

Journal of the Iowa Academy of Science: JIAS

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Entertainics, Jesus Mario Torres Garza

Theses Digitization Project

Entertainics is a web-based software application used to gather information about DVD players from several web-sites on the internet. The purpose of this software is to help users search for DVD players in a faster and easier way, by avoiding the navigation on every web-site that contains this product.

Intergalactic Globular Clusters, Michael J. West, Ted Von Hippel, Patrick Cote, Henry C. Ferguson, Michael D. Gregg, Andres Jordan, Ronald O. Marzke, Nial R. Tanvir

Publications

We confirm and extend our previous detection of a popula- tion of intergalactic globular clusters in Abell 1185, and report the first discovery of an intergalactic globular cluster in the nearby Virgo cluster of galaxies. The numbers, colors and luminosities of these objects can place constraints on their origin, which in turn may yield new insights to the evolution of galaxies in dense environments.

Afm, Cafm, And Efm Studies Of The Gan System, John C. Dickinson

Theses and Dissertations

This thesis discusses a variety of techniques based on the atomic force microscope (AFM), and their application to the GaN materials system. In particular, the local conductivity and contact potential of surfaces have been measured using the techniques of Conductive AFM (CAFM) and Surface Potential Electric Force Microscopy (SPEFM), respectively. CAFM studies of GaN surfaces have revealed that prismatic planes around islands and pits on surfaces can lead to enhanced conductivity, which may be related to leakage problems in device applications. With regard to SP-EFM work, the change in surface potential associated with inversion domains on Ga-polar GaN has been …

Fish Population Dynamics During The Establishment Phase Of A Constructed Wetland, Danielle Alegre

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Wetlands Park Nature Preserve in Clark County Nevada is a constructed wetland that is home to several species of fish. The purpose of this study is to report on the fluctuations of the fish populations during the first 20 months of monitoring at the Wetlands Park Nature Preserve. This thesis analyzes the fish monitoring data in order to assess the behavior of the fish population of the Wetlands Preserve. As the environment at the Wetland has changed during its initial establishment, so has the fish population. Using data collected during the monthly monitoring protocol from June 2001 to January …

Antiforce Wave Profile For Quasi-Neutral Region, Mostafa Hemmati, Pashupati Adhikari, Jeremy Eckart, Marcus Ilbara

Journal of the Arkansas Academy of Science

This article will present a fluid dynamical theory for breakdown waves in which the direction of electric field force on electrons is in the opposite direction of wave propagation. We will refer to such waves as antiforce waves. The set of equations describing the model will include the equation of particle mass balance, equation of conservation of momentum, and equation of conservation of energy, coupled with Poisson's equation. This model treats the potential wave front as an electron shock wave propagating forward mainly due to the electron impact ionization. The shock front is succeeded by a thin dynamical transition region …

Swimming Performance Of Juvenile Florida Pompano (Trachinotus Carolinus) And Atlantic Spadefish (Chaetodipterus Faber) Exposed To Sublethal Concentrations Of Ethylene Glycol And Methanol: Individual And Synergistic Effects, Mark Alan Stead

LSU Master's Theses

Recently, new technology has pushed petrochemical exploration into increasingly deeper water (>305 m) at increased risks to marine fauna. One risk is from chemical additives used to enhance deepwater production such as ethylene glycol and methanol which are used during the production and treatment to prevent the formation of gas hydrates in deepwater wells and pipelines. Juvenile Florida pompano (Trachinotus carolinus) were used in controlled experiments to test the effects of 3.0 % ethylene glycol (EG), 1.07 % methanol (MeOH) and a combination of the two chemicals(EG + MeOH) on swimming performance of individual fish. Swimming performance was evaluated …

Effect Of Temperature On Efficiency Of In Situ Bioremediation Technology: A Laboratory Microcosm And Field Study, Javed Iqbal

LSU Master's Theses

Laboratory microcosm experiment and parallel ex situ bioremediation studies were conducted to study the effect of temperature on in situ bioremediation systems installed at Superfund site in southeast Georgia. Laboratory microcosms, inoculated with PAHs/phenols specific microorganisms, at high temperatures (42±2°C; 107±3°F) demonstrated a significant reduction of residual polycyclic aromatic hydrocarbons (PAHs) and selected phenols from 4927±1356ng/g dry weight soil to 1158±530ng/g with a kinetic rate of 76.1±16.8ng/g/day (84% reduction; p≤0.01) in 49days. High temperature non-inoculated microcosms were reduced of residual PAHs and phenols from 1117±436ng/g to 341±116ng/g with a kinetic rate of 15.8±6.5ng/g/day (65% reduction; p≤0.01) in 49days. Low temperature …

Compositional Systematics Of Deep, Low Salinity Formation Waters In The Upper Wilcox Of Southeastern Texas, Kathleen (Kt) Moran

LSU Master's Theses

Overpressured Eocene Wilcox sandstones in the Newton County, Texas Sabine Tram field contain water with salinities ranging from 14 to 28 g/L. The solutes appear to fall loosely into three groups. Na, Ca, and Mg follow systematics previously known globally for saline formation waters whereby their concentrations are controlled by fluid-mineral equilibrium. Cl, Br, I, and B are conservatively diluted constituents of some saline endmember that is not solely connate marine. Potassium does not follow any known basinal systematic, and the formation water is supersaturated with respect to SiO2 by an order of magnitude. Meteoric water is not a probable …

A Stellar Parameter Calibration Of Iue Data For The Determination Of The Present Day Mass Function Of High Mass Stars, Kenneth Thomas Taylor

LSU Master's Theses

A study of stellar atmosphere models and the photometric quantity R is presented here, with R being the ratio of the integrated de-reddened fluxes from the two wavelength regions of the International Ultraviolet Explorer (IUE) satellite cameras. The effective temperatures and surface gravities of the stellar atmospheres were calibrated against R and absolute magnitude, using stellar evolution tracks from the literature, and applied to over 156 LMC stars whose masses and mass function are then derived from the results. The results show that the effective temperatures and surface gravities of stars derived from R and absolute magnitude correlate well with …

Pcr Inhibition And Toxic Effects By Sediment Samples Exposed To Drilling Muds, Neal Gilpin Satterly

LSU Master's Theses

This study evaluated the PCR inhibition and toxic effects by sediment samples exposed to drilling muds. This information was gathered in an attempt to identify what effect, if any, drilling muds had on the microbial community structure in sediments around four specific oil-drilling platforms in the Gulf of Mexico. Sediment samples were taken before and after drilling had taken place around two platforms (GB516 and VK916), and sediment samples were taken after drilling had taken place around two other platforms (MC292 and GB602). After using traditional, non-selective DNA extraction methods, successful amplification took place via PCR with all pre-drilling samples …

Development And Implementation Of Fine Structure Aerosol Spectrum Coagulation Kernels And Deposition Mechanisms Using Advanced Nodal Method In The Caerot Code, Hyeongkae Park

LSU Master's Theses

Aerosol transport in confined spaces was studied via numerical simulation using the dynamic aerosol equation, which is Boltzmann?s transport equation at the hydrodynamic limit. Until recent years, there existed no comprehensive computational tool to predict the spatial distribution and time evolution of aerosol size spectrum. A previously developed code, INDASOL3D, solves the dynamic aerosol equation by using a homogenized control-volume based finite difference method applying the group sectional method on the coagulation dynamics. However, quantitative correctness has not been satisfactory. In this thesis, two new codes (SAEROSA, and CAEROT) were developed. SAEROSA computes the time evolution of the size spectrum …

Role Of Eintermediaries In The United States Paper Supply Chain, Sanna Maria Kallioranta

LSU Master's Theses

In an attempt to streamline the paper supply chain, paper industry vertical business-to-business eMarketplaces were established to help industry players to decrease inefficiencies in their supply chains, to minimize negative effects of economic cyclicality, and to achieve better visibility. eMarketplaces rode the hype of revolutionizing the way in which industries conduct business, citing the cost savings achieved by expanded market reach, operational efficiencies, aggregated purchasing, and finding the least expensive suppliers. Adoption of eIntermediaries has been lower than expected in the paper industry and many of the paper vertical start-ups failed when the economy softened and the dot.com bubble burst. …

Stock Price Modeling And Insider Trading Theory, Jessica J. Guillory

LSU Master's Theses

The mathematical study of stock price modeling using Brownian motion and stochastic calculus is a relatively new field. The randomness of financial markets, geometric brownian motions, martingale theory, Ito's lemma, enlarged filtrations, and Girsanov's theorem provided the motivation for a simple characterization of the concepts of stock price modeling. This work presents the theory of stochastic calculus and its use in the financial market. The problems on which we focus are the models of an investor's portfolio of stocks with and without the possibility of insider trading, opportunities for fair pricing of an option, enlarged filtrations, consumptions, and admissibility. This …

Surface Water Pesticide Contamination In The Upper Terrebonne Basin Of Louisiana, John S. Walther

LSU Master's Theses

Triazine herbicides are the most heavily used pesticides in the United States. Atrazine and Simazine are the primary triazine herbicides used for broadleaf weed control in the production of corn, sugarcane, and sorghum. Recent monitoring studies of surface waters in the Upper Terrebonne Basin of Louisiana indicate elevated amounts of triazines are running off fields and entering drinking water supplies. Atrazine has been classified as a possible carcinogen by the United States Environmental Protection Agency. Recent epidemiological studies have revealed increases in breast cancer and pre-term births following exposure to triazines at levels detected in drinking water. Non-point source pollution …

Comparative Analysis Of State Environmental Enforcement In Region Six Of The United States, Rebecca Marcus

LSU Master's Theses

Through intense studies of agency audits, EPA policies and documents, state environmental compliance data and state agency issued documents, I have evaluated the enforcement programs of Region Six state environmental agencies. The four elements utilized to perform this evaluation were listed in EPA compliance assurance program documents. The analysis was conducted by comparing state program performance in each element. Element 1 is the “appropriate identification of violations.” Element 2 is the “timely issuance of enforcement actions.” Element 3 is the “escalation of enforcement actions when violations continue.” Element 4 is the “ability to assess and collect penalties.” These elements are …

Constraint Preserving Boundary Conditions For The Linearized Einstein Equations, Gioel Calabrese

LSU Doctoral Dissertations

The successful construction of long time convergent finite difference schemes approximating highly gravitating systems in general relativity remains an elusive task. The presence of constraints and the introduction of artificial time-like boundaries contribute significantly to the difficulty of this problem. Whereas in the absence of boundaries the Bianchi identities ensure that the constraints vanish during evolution provided that they are satisfied initially, this is no longer true when time-like boundaries are introduced. In this work we consider the linearization around the Minkowski space-time in Cartesian coordinates of the generalized Einstein-Christoffel system and analyze different kinds of boundary conditions that are …

Multileaf Collimator Positional Reproducibility Evaluated With A Two-Dimensional Diode Array, Kara King Ferachi

LSU Master's Theses

When delivering the total dose via a sequence of small fields shaped by a multileaf collimator, it is important to consider leaf positional reproducibility. A small error in the leaf position can result in large dose errors to the entire field. This is true for both dynamic multileaf collimation and step and shoot delivery. The goal of this research project is to design a method of quality assurance that is easily reproducible, sensitive to small changes in leaf position, and requires minimal time on the part of the medical physicist to carry out. This paper describes a system of measurements …

Pulsed River Flooding Effects On Sediment Deposition In Breton Sound Estuary, Louisiana, Katherine Wheelock

LSU Master's Theses

Louisiana's deltaic coast is a dynamic sedimentary environment made vulnerable by Mississippi River channelization, which restricts freshwater, sediment, and nutrient inputs to adjacent estuaries. Freshwater diversions now reconnect some estuaries with historic fluvial sources, like Breton Sound basin, which receives Mississippi River suspended loads through the Caernarvon freshwater diversion. The project objectives were to quantify short-term sediment accumulation using sediment traps, evaluate sediment trap effectiveness, and compare long-term deposition using feldspar horizon markers and 210Pb dating to the annual sediment trap deposition. Magnitude and variations of sediment deposition at 14 sites were compared during an 18-month study in the upper …

Ethical Issues In Open Source Software, Frances Grodzinsky, Keith W. Miller, Marty J. Wolf

School of Computer Science & Engineering Faculty Publications

In this essay we argue that the current social and ethical structure in the Open Source Software (OSS) Community stem from its roots in academia. The individual developers experience a level of autonomy similar to that of a faculty member. Furthermore, we assert that the Open Source Software Community's social structure demands benevolent leadership. We argue that it is difficult to pass off low quality open source software as high quality software and that the Open Source development model offers strong accountability. Finally, we argue that Open Source Software introduces ethical challenges for universities and the software development community.

Paleomagnetism Of The Mt. Stuart Batholith Revisited Again: What Has Been Learned Since 1972?, Bernard A. Housen, Myrl E. Beck Jr., Russ R. Burmester

Geology Faculty Publications

We have collected 20 new paleomagnetic sites from the Mount Stuart batholith and the adjacent Beckler Peak stock. Using thermal and low-temperature demagnetization, and rockmagnetic tests, we have found that the remanence in most of the batholith is carried by single-domain magnetite. The mean of the new Mount Stuart batholith sites is D = 354.2°, I = 46.2°, k = 87.2, α95 = 4.6°, N = 11, and is similar to those of the Beck and Noson (1972) and Beck and others (1981) studies. Examination of Ar geochronology of hornblende and biotite from the Mt. Stuart batholith finds that the …

Where To Sit? A Look At Frequency's Effect On Volume Distribution In The Singletary Concert Hall, Matthew Williams

Kaleidoscope

The objective of this project was to find the best seat in the Concert Hall of the Singletary Center for the Arts, here at the University of Kentucky. While subjective factors often determine a patron's favorite place to sit, I decided that an objective scientific approach could prove useful when I, or anyone, next attended a concert. Using only a keyboard amplified by speakers placed at center stage and a sound level monitor, I measured separately the volume of six different frequencies (at intervals of an octave) at twelve different seats throughout the Hall. Defining the best seat as the …

Avoiding The “Fat” Of The Land: Case Studies Of Agricultural Nutrient Balance, David Weaver, Simon Neville

Journal articles

Let’s start with a simple analogy: if a person eats more than they need, they gain weight. That is: if our feed inputs (kilojoules in) are greater than our outputs (exercise — kilojoules out) then we will gain weight (kilojoules in storage).That’s our fat. If, on the other hand, our feed inputs are less than our outputs, then we will lose weight.And if our inputs are the same as our outputs, our weight will remain constant. In general, the further away you are from an ‘ideal’weight, the greater the health risks. And yes, other aspects of your body management — …

Inflation In A Flat Universe, Koray Karaca, Selçuk Bayin

Turkish Journal of Physics

We started the evolution of a flat universe from a nonsingular state called prematter which is governed by an inflationary equation of state P=(\gamma -1)\rho , where \gamma represents the initial vacuum dominance of the universe. The evolution of the universe-except in the prematter era-is affected neither by the initial vacuum dominance nor by the initial expansion rate of the universe. On the other hand, present properties of the universe, such as the Hubble constant, age and density, are sensitive to the value of the temperature at the decoupling ( T_{m}) . Over a range between 3\cdot 10^{4}and 5\cdot 10^{4} …

Variation In Thickness Of Copper Films Deposited At Various Distances And Angles Using The Thermionic Vacuum Arc, Tamer Akan, Naci̇ Ekem

Turkish Journal of Physics

The thermionic vacuum arc (TVA) is a new technique for the deposition of thin metallic films. Copper depositions were made on glass substrates placed at various distances and angles with respect to the TVA source. By measuring the thickness of the film on each substrate, the variation in the thickness as a function of the distance and angle with respect to the TVA source is investigated.

A Study Of Direct Two-Proton Transfer Reactions Using Optical Potential Model, A. K. A. R. Al-Farra

Turkish Journal of Physics

^{12}C, ^{26}Mg(^3He,n) reactions have been studied at high bombardment energy with evaluation of the differential cross sections to the ground and the first excited states evaluated in the framework of the exact finite-range Born approximation (DWBA) calculations using the optical model. With the constraint that bound-state interactions have a Thomas-Fermi spin orbit form, different formations of the bound-state wave functions are explored. The calculated angular distributions are found to be in a good agreement with the experimental data. The present DWBA predictions are normalized to give the best overall fits to the data. The extracted spectroscopic factors are reasonable.

First Principles Modeling Of Nanostructures, Serdar Öğüt

Turkish Journal of Physics

Among the various theoretical tools for investigating microscopic material properties, ab initio (first principles) methods based on density functional theory and pseudopotentials have had a very good track record over the last two decades in terms of accuracy, reliability, and efficiency. The application of these methods to nanostructures to investigate their structural, electronic, and optical properties has, however, not been quite straightforward due to the large computational demand and new physics inherent in the nanometer and sub-nanometer size region. One particularly useful extension to overcome the computational demand imposed by localized nanostructures has been the introduction of methods based on …

Implementation Plan For The Conservation Of Nebraska’S Eastern Saline Wetlands, Ted Lagrange, Terry Genrich, Glenn Johnson, Dan Schulz, Brent Lathrop

Nebraska Game and Parks Commission: Publications

Nebraska’s Eastern Saline Wetlands are the most limited and endangered wetland type and vegetation community in the State and are considered critically imperiled in Nebraska. These wetlands provide habitat for a variety of native plant and animal species that depend on a saline environment, including two endangered species.

Because of their location in and around the city of Lincoln, saline wetlands are ideally located to provide recreational opportunities and flood protection. Past impacts have resulted in the degradation of nearly 90% of the saline wetlands and those remaining face continued threats.

Although several programs are in existence to address saline …

Ecophysiology Of Seedlings Of Three Mediterranean Pine Species In Contrasting Light Regimes, Tala Awada, Kalliopi Radoglou, Mariangela N. Fotelli, Helen I. A. Constantinidou

School of Natural Resources: Faculty Publications

Seasonal dynamics of net photosynthesis (A_net) in 2-year-old seedlings of Pinus brutia Ten., Pinus pinea L. and Pinus pinaster Ait. were investigated. Seedlings were grown in the field in two light regimes: sun (ambient light) and shade (25% of photosynthetically active radiation (PAR)). Repeated measures analyses over a 12-month period showed that A_net varied significantly among species and from season to season. Maximum A_net in sun-acclimated seedlings was low in winter (yet remained positive) and peaked during summer. Maximum A_net was observed in June in P. pinea (12 μmol m^–2 s^–1), …

Iowa Academy Of Science 115th Annual Meeting [2003]: Advance Program, Iowa Academy Of Science

Iowa Academy of Science Documents

Contains information about the schedule and presentations for the 2003 annual meeting of the Iowa Academy of Science.