Physical Sciences and Mathematics Commons^™

"Hands-On" Epicycles And Retrograde Motion, Matthew J. Moelter, Bernard A. Bates

Physics

No abstract provided.

A Parallel Algorithm For Determining Orientations Of Biological Macro- Molecules Imaged By Electron Microscopy, Timothy S. Baker, Ionana M. Boier Martin, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.

The Platonic Spheroids, Jörg Peters, Leif Kobbelt

Department of Computer Science Technical Reports

No abstract provided.

Interactive Visualization Of Multi- Dimensional Scientific Data (Ph.D. Thesis), Daniel R. Schikore

Department of Computer Science Technical Reports

No abstract provided.

Compact Recognizers Of Episode Sequences, Alberto Apostolico, Mikhail J. Attalah

Department of Computer Science Technical Reports

No abstract provided.

Collaborative Environments For Scientific Computing The Task Of Algorithm/Software Selection, N. Ramakrishnan, Anupam Joshi, Elias N. Houstis, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Temperature-Dependence Studies Of Photorefractive Effect In A Low Glass-Transition-Temperature Polymer Composite, Bogdan Swedek, Ning Cheng, Yiping Cui, Jaroslaw W. Zieba, Jeffrey G. Winiarz, Paras N. Prasad

Chemistry Faculty Research & Creative Works

The temperature dependence of the photorefractive effect in a polymer composite containing poly(9-vinycarbazole), tricresyl phosphate, buckminsterfullerene, and 4-(N,N-diethylamino)-β-nitrostyrene is presented. The photoconductive, electro-optic and photorefractive properties of the material have been studied in the temperature range of 22-61°C. An apparent increase of electro-optic modulation with temperature and its eventual saturation is observed. This behavior is attributed to the temperature activated orientational mobility of the second-order nonlinear chromophores. The polarization anisotropy between the p- and s-polarized readouts is consistent with what would be expected on the basis of directly measured effective electro-optic coefficients. By correlating the electro-optic value with the diffraction …

Preliminary Investigation Of The Extent And Effects Of Sediment Contamination In White Lake Near Whitehall Leather Tannery, Richard Rediske, Gary Fahnenstiel, Tom Nalepa, Peter Meier, Claire Schelske

Scientific Technical Reports

By using a combination of chemistry, toxicological evaluation, ecological analysis, and radiodating, this investigation has defined the ecological effects and the nature and extent of sediment contamination in the Tannery Bay area of eastern White Lake. The sediments in Tannery Bay represent a source of chromium transport for most of the eastern basin of White Lake. The recent deposition of chromium contaminated sediments exceeding 500 mg/kg in down gradient locations shows that export processes are responsible for the movement of this material from Tannery Bay. Arsenic and mercury appear to be less mobile and are retained in the sediments of …

A Large Scintillation Detector For Nuclear Physics Experiments At Indiana University Cyclotron Facility, Apurva Pathak

Masters Theses

A new, large, scintillation detector, called the "K" detector has been designed and built for use in a series of nuclear physics experiments being performed at the Indiana University Cyclotron Facility (IUCF). This project describes the design, construction and testing of this scintillation detector. The K detector was designed to augment an existing detector stack at IUCF, and will serve to increase the energy range of previous studies of neutral pion production in proton-proton collisions near threshold. The test data for the current project came from a proton-proton scattering experiment, during which several runs were carried out between the bombarding …

Lithologic And Stratigraphic Analysis Of Glacial Diamictons, Sturgis, Michigan, R. Christopher Gardner

Masters Theses

Seven diamictons are identified in the subsurface glacial drift near Sturgis, Michigan using textural analyses and x-ray diffraction of clay minerals. The clay mineral content is quantified by comparing the 7-A/10- A peak height ratios from x-ray diffraction diffractograms of oriented clay-size particle (< 2um) mounts. Two diamictons occur at the base of the drift. Unit 1 is gray , resembling the shale it overlies. The texture of Unit 1 is sandy clay loam to loam and average 7-A/10-A peak height clay mineral ratios of 0.446 ±0.069. Unit 2 is a yellowish-brown diamicton, it overlies Unit 1, and is a sandy loam to loam with average 7-A/10-A clay mineral ratio of 0.657 ±0.151. Diamicton Units 4 and 5 overlie a thick unit of sand and gravel on top of Unit 2. Units 4 and 5 have similar color and texture, however the 7-A/10-A ratios are 1.059 ±0.090 and 0.810 ±0.072 respectively. Unit 6 is a thin diamicton unit, leached of calcite, and x-ray diffraction suggests that there is a range of weathering horzins between borings. Unit 7 is loamy, whereas Unit 8 generally ranges from sandy clay loam to sandy loam with average 7-A/10-A ratios of 0.865 ±0.090 and 1.195 ±0.189.

Pan, Ppn And Mpan Measurements And The Systematic Relationship Between Mpan And Macr At A Semi-Rural Site In Tennessee, George Nouaime

Masters Theses

Simultaneous measurements of peroxymethacryloyl nitrate (MPAN) and its primary and secondary precursors, methacarolein (MACR) and isoprene, were carried out for the first time in July 1995 at a semi-rural site southeast of Nashville. In addition to these compounds, peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), other volatile organic compounds (VOCs) and supporting measurements were also collected in collaboration with other research groups. The mean concentrations of PAN, PPN, MPAN and MACR were found to be 485 pptv, 50 pptv, 30 pptv and 0.290 ppbv respectively. MP AN levels, which closely tracked those of MACR during the day, peaked and dropped earlier …

The Century Survey: A Deeper Slice Of The Universe, Margaret J. Geller, Michael J. Kurtz, Gary Wegner, John R. Thorstensen

Dartmouth Scholarship

The "Century Survey" (CS hereafter) is a complete redshift survey of a 1° wide strip. It covers 0.03 steradians to a limiting m_R = 16.13. The survey is 98.4% complete and contains 1762 galaxies. Large-scale features in the survey are qualitatively similar to those in other surveys: there are large voids surrounded or nearly surrounded by thin dense regions which are sections of structures like (and including) the Great Wall. The survey crosses the classical Corona Borealis supercluster. The galaxy density enhancement associated with this system extends for <˜100h^-1 Mpc^-1 (the Hubble constant is H₀ = 100h …

Year In Review - 1997, Annis Water Resources Institute

AWRI Reviews

No abstract provided.

Data Assimilation Experiments In The Gulf Stream Region: How Useful Are Satellite-Derived Surface Data For Nowcasting The Subsurface Fields?, Tal Ezer, George L. Mellor

CCPO Publications

Satellite-derived surface data have become an important source of information for studies of the Gulf Stream system. The question of just how useful these datasets are for nowcasting the subsurface thermal fields, however, remains to be fully explored. Three types of surface data-sea surface temperature (SST), sea surface height (SSH), and Gulf Stream position (GSP)-are used here in a series of data assimilation experiments to test their usefulness when assimilated into a realistic primitive equation model. The U.S. Navy's analysis fields from the Optimal Thermal Interpolation System are used to simulate the surface data and to evaluate nowcast errors. Correlation …

Volcanology And Geochemistry Of Pliocene And Quaternary Basalts On Citadel Mountain, Lunar Crater Volcanic Field, Pancake Range, Nevada, Loretta D. Dickson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alkali basalts on Citadel Mountain form the southern margin of the Lunar Crater Volcanic Field (LCVF) in the central Great Basin, Nevada. Citadel Mountain comprised of a faulted, north tilted section of Tertiary andesite and ash-flow tuff is capped by Pliocene and Quaternary alkali basalt flows that erupted from six major cinder cones. The basalt flows on Citadel Mountain can be divided into two groups (older and younger) based on age and isotopic signatures. The older basalt group is characterized by higher ⁸⁷ Sr/⁸⁶Sr and lower E_Nd and the younger group has lower ⁸⁷Sr/⁸⁶Sr …

Evidence For A Shore-Normal Energy Gradient And Its Character In The Speiekeroog Back Barrier Tidal Flats, German North Sea Coast, N Nyandwi

Tanzania Journal of Science

Sediment distribution in the Spiekeroog backbarrier tidal flats has been studied with the aim of identifying the factors controlling their deposition. Form the mainland coast northwards three physiographic units are recognizable namely, the tidal flats adjacent to the coast, the tidal channels with the intervening flats and the dunes and tidal flats adjoining Spiekeroog island. The areal distribution of the sand fraction (˂4.0 phi) shows a shore normal energy gradient with increasing energy towards the sea. Very fine sands are found very close to the mainland coast, fine to very fine in the central part and fine sand on the …

Application Of Geophysical And Geochemical Techniques For The Assessment Of Groundwater Recharge From Wadi Al Bih Dams, Ras Al Khaimah, United Arab Emirates, Mohamed Sager Al Asam

Theses

Groundwater from Wadi AI Bih is still a major source of water required for irrigation, industry and domestic purposes in Ras AI Khaimah area, United Arab Emirates. Because of the continuous population growth, demand for pumping more water has created an imbalance in the groundwater resources of Wadi AI Bih basin, and the estimated discharge (11 million m³/year) has exceeded the calculated natural recharge (9 million m³/yr). To restore the balance between natural recharge and discharge and maintain a good-quality groundwater, the UAE government has built Wadi AI Bih dams in 1982.

The objectives of this …

Inhibitory Effect Of Carbamate On The Cell Division Of Rat Bone Marrow, Mariam Hamad Rashed Al-Dhaheri

Theses

The cytotoxic effect of methomyl carbamate was studied in three groups (control group, 1 % treated group and 10% treated group) and each group contain 2-3 White Wistar rats. The 1% treated group was received 1 % of methomyl LD₅₀, while the 10% treated group was received 10% of methomyl LD₅₀. The administration was orally and repeated three times with 24 hr intervals time. The effect of methomyl was investigated in four experimental run, by analysing the change in cell count in bone marrow after methomyl treatment. It was found that methomyl treatment caused significant reduction …

A Search For Excited Fermions In E+P Collisions At Hera, J. Breitweg, M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. Repond, R. Stanek, R. L. Talaga, R. Yoshida, H. Zhang, Margarita C. K. Mattingly, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti

Faculty Publications

Using the ZEUS detector at HERA, we have searched for heavy excited states of electrons, neutrinos, and quarks in e+p collisions at a center-of-mass energy of 300 GeV. With an integrated luminosity of 9.4 pb-1, no evidence was found for electroweak production and decay of such states. Limits on the production cross section times branching ratio and on the characteristic couplings, f/Λ, are derived for masses up to 250 GeV. For the particular choice f/Λ = 1/Mf*, we exclude at the 95% confidence level excited electrons with mass between 30 and 200 GeV, excited electron neutrinos with mass between 40 …

Near-Field Measurements On Contrail Properties From Fuels With Different Sulfur Content, Andreas Petzold, Reinhold Busen, Franz Peter Schroder, Robert Baumann, Markus Kuhn, Johan Strom, Donald E. Hagen, Philip D. Whitefield, Darrel G. Baumgardner, Frank Arnold, Stephan Borrmann, Ulrich Schumann

Physics Faculty Research & Creative Works

Microphysical properties of jet exhaust aerosol and contrails were studied in the near field of the emitting aircraft for different fuel sulfur contents. Measurements were performed behind two different aircraft (ATTAS test aircraft of type VFW 614 and Airbus A310-300) using fuels with sulfur contents of 6 ppm and 2700 ppm, respectively. At closest approach (plume age < 1 s), the total number concentrations exceeded the measuring range of the condensation particle counter, i.e., N > 10⁵ cm^-3. The concentration of the dry accumulation mode aerosol, i.e., predominantly soot particles, was not affected by the fuel sulfur content. At a plume age of 10 s, an increase in total number concentration (Dp > 0.01 μm) by a …

Bound Μ⁺Μˉ System, Ulrich D. Jentschura, Gerhard Soff, Vladimir G. Ivanov, Savely Karshenboim

Physics Faculty Research & Creative Works

We consider the hyperfine structure, the atomic spectrum, and the decay channels of the bound μ⁺μ^- system (dimuonium). The annihilation lifetimes of low-lying atomic states of the system lie in the 10^-12 s range. The decay rates could be measured by detection of the decay products (high-energy photons or electron-positron pairs). The hyperfine-structure splitting of the dimuonic system and its decay rate are influenced by electronic vacuum polarization effects in the far timelike asymptotic region. This constitutes a previously unexplored kinematic regime. We evaluate next-to-leading-order radiative corrections to the decay rate of low-lying atomic states. We …

Flow And Congestion Control For Internet Streaming Applications, Shanwei Cen, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

The emergence of streaming multimedia players provides users with low latency audio and video content over the Internet. Providing high-quality, best-effort, real-time multimedia content requires adaptive delivery schemes that fairly share the available network bandwidth with reliable data protocols such as TCP. This paper proposes a new flow and congestion control scheme, SCP (Streaming Control Protocol) , for real-time streaming of continuous multimedia data across the Internet. The design of SCP arose from several years of experience in building and using adaptive real-time streaming video players. SCP addresses two issues associated with real-time streaming. First, it uses a congestion control …

Optimal Pulsed Pumping For Remediation Of Aquifers When Sorption Is Rate-Limited, Lawrence J. Schmitt

Theses and Dissertations

A variational optimization technique is developed to acquire an optimal schedule of pulsed pumping operations for use at existing pump-and-treat aquifer remediation sites. The optimization problem is stated as a minimization of a generic management objective functional, constrained by the contaminant transport equations in two-dimensional or three-dimensional flow models which account for rate-limited sorption. The two-dimensional case is fully developed and a first-order rate equation is used to describe the transport of sorbing contaminant. The first variation provides necessary optimality conditions that must be met by any optimal solution, in turn leading to a pulsed pumping schedule of operation. The …

Time Resolved Photoluminescence Spectra Of A Mid-Infrared Multiple Quantum Well Semiconductor Laser, Anthony L. Franz

Theses and Dissertations

Recombination mechanisms in mid-IR semiconductor lasers are strongly dependent on the carrier density of the active region. The objective of this research is to improve previous carrier density estimates through the incorporation of spectral information. One hundred photoluminescence (PL) spectra were calculated for a variety of carrier densities. Calculations were made for an InAsSb/InAlAsSb multiple quantum well laser sample assuming parabolic bands. The widths of the calculated spectral profiles were tabulated as a function of carrier density. Actual spectra were measured using the Ultrafast Mid-Infrared Photoluminescence System, which uses upconversion to measure the PL intensity in time steps smaller than …

A Model For Determining Information To Be Captured Regarding Unauthorized Computer Entry Of An Air Force Computer System, Leslie F. Himebrook

Theses and Dissertations

This thesis presents a model of information to capture regarding unauthorized computer systems access attempts. This model takes a management focus, and incorporates the technical focus, intelligence focus, and legal focus as inputs. The author used an exploratory, qualitative methodology consisting of an extensive literature review and interviews with experts in the field. These efforts produced the proposed model, which was reviewed by experts in the field using a delphi technique. The model consists of information that is divided into the following areas: 1. What information was compromised. 2. What type of intrusion occurred. 3. How the intrusion was attempted. …

A Single Chip Low Power Implementation Of An Asynchronous Fft Algorithm For Space Applications, Bruce W. Hunt

Theses and Dissertations

A fully asynchronous fixed point FFT processor is introduced for low power space applications. The architecture is based on an algorithm developed by Suter and Stevens specifically for a low power implementation. The novelty of this architecture lies in its high localization of components and pipelining with no need to share a global memory. High throughput is attained using large numbers of small, local components working in parallel. A derivation of the algorithm from the discrete Fourier transform is presented followed by a discussion of circuit design parameters specifically, those relevant to space applications. The generic architecture is explained with …

A Representational Approach To Knowledge And Multiple Skill Levels For Broad Classes Of Computer Generated Forces, Larry J. Hutson

Theses and Dissertations

Current computer generated forces (CGFs) in the 'synthetic battlespace', a training arena used by the military, exhibit several deficiencies. Human actors within the battlespace rapidly identify these CGFs and defeat them using unrealistic and potentially fatal tactics, reducing the overall effectiveness of this training arena. Simulators attached to the synthetic battlespace host local threat systems, leading to training inconsistencies when different simulators display the same threat at different levels of fidelity. Finally, current CGFs are engineered 'from the ground up', often without exploiting commonalities with other existing CGFs, increasing development (and ultimately training) costs. This thesis addresses these issues by …

Evaluation Of The Natural Biodegradation Of Aircraft Deicing Fluid Components In Soils, Laura M. Johnson

Theses and Dissertations

This research effort was conducted to analyze the biodegradation of propylene glycol (PG) and tolyltriazole in two different soil types; a sandy soil and a high clay soil. Both an automated respirometer and a high performance liquid chromatograph (H PLO) were used in the analysis. Two separate experiments were conducted. In the first experiment, one level of tolyltriazole was added to the soils to determine whether or not there was a difference in the biodegradation rates of tolyltriazole in the two soils. The respirometer results indicated that there was a significant difference between the respiration rates of the microorganisms in …

Mobilization Of Trace Elements In Aquifers By Biodegradation Of Hydrocarbon Contaminants, Scott L. Kearney

Theses and Dissertations

This study had two objectives: (1) to determine the extent of metal mobility within petroleum-contaminated aquifers, (2) to determine if biodegradation of petroleum hydrocarbons can explain metal mobility. The approach reviewed analytical results from 2305 groundwater sampling events, taken from 958 wells, located at 136 sites found at 53 Air Force installations. The study showed that high levels of metals are present at petroleum hydrocarbon sites where metals would not generally be expected. Of the metals with drinking water maximum contaminant levels (MCLs), mercury and silver were detected the least frequently. Barium and copper were detected at the sites, but …

A Modeling And Simulation Approach To Characterize Network Layer Internet Survivability, Leif S. King

Theses and Dissertations

The Air Force Core Competency of Information Superiority will be achieved in an age of decreasing AF manpower and corporate expertise. Increased AF reliance on COTS solutions, coupled with nearly ubiquitous points of entry to communication networks, create unique challenges in maintaining the Information Superiority edge. The protection of the internet is part of this equation. The internet supports the daily business traffic of the Air Force. Personnel, finance, and supply data flow through its routers. Controlling an adversary's access to our information systems, either the data, or the hardware and software that control the data and transform it into …