Physical Sciences and Mathematics Commons^™

Microanalytical Investigations Of Gold-Bearing Rocks From The An Najadi Region In Saudi Arabia, Nazrul I. Khandaker, M. Ahmed, M. M. Hariri, M. A. Garwan, K. R. Khan, M. M. Al-Ohali

Publications and Research

The Proton Induced X-ray Emission technique with a scanning microbeam (micro-PIXE) and Scanning Electron Microscopy (SEM) were employed to study gold-bearing rocks from the An Najadi and adjacent regions situated within the exposed northeastern part of the Arabian Shield. These microanalytical investigations, together with routine petrological and ore microscopic studies, demonstrated the presence of important partitioning of major minerals and trace elements in several samples. These measurements also revealed microstructural features including brecciation within quartz grains and metal concentrations within these fracture-controlled micro-conduits. Results showed promise in terms of using distinctive geochemical signatures for ore body recognition. Of particular interest …

Resonance Feature In Al- Photodetachment Below The Al(3S24S 2S) Threshold, B.J. Davies, C.W. Ingram, D.J. Larson, Chien-Nan Liu, Anthony F. Starace

Anthony F. Starace Publications

Photodetachment of Al-(3s²3p²³ 3P) near the threshold of the first excited state of neutral aluminum has been studied both experimentally and theoretically. A 19-keV mass-resolved Al- beam was intersected by a frequency-doubled neodymium-doped yttrium aluminum garnet pumped dye-laser beam, and the fast atoms created by detachment processes were detected. Measurements just below the threshold of the first excited state, Al(3s²4s²S), find a large resonance peak in the detachment signal. An eigenchannel R-matrix calculation generates a resonance structure that is qualitatively similar to the data and identifies the large resonance …

Native Vegetation Handbook For The Shire Of Brookton, Rod Safstrom

Native vegetation handbook series

This Handbook is one of a series covering the agricultural region of Western Australia. The Handbook aims to assist the development of sustainable farming systems which combine agricultural production and nature conservation. Information is provided on the natural resources of the Shire of Brookton, including the existing vegetation, drainage systems and soils. Problems in managing these resources are described and community initiatives to tackle the problems are summarised. It is hoped this Handbook will contribute to the long term viability of the agricultural landscape and the conservation of native vegetation within the Shire.

Nondipole Resonant X-Ray-Raman Spectroscopy: Polarized Inelastic Scattering At The K Edge Of Cl2, J. D. Mills, J. A. Sheehy, T. A. Ferrett, S. H. Southworth, R. Mayer, Dennis W. Lindle, P. W. Langhoff

Chemistry and Biochemistry Faculty Research

Experimental and theoretical studies are reported on the inelastic (Raman) scattering of wavelength-selected polarized x rays from the K edge of gas-phase chlorine molecules. The polarized emission spectra exhibit prominent nondipole features consequent of phase variations of the incident and emitted radiation over molecular dimensions, as predicted by the Kramers-Heisenberg scattering formalism. Issues pursuant to the detection of core-hole localization by resonant Raman scattering from homonuclear diatomic molecules are critically examined. [S0031-9007(97)03486-8]

Report On The 5th Ifip International Workshop On Quality Of Service, Oguz Angin, Andrew T. Campbell, Lai Tee Cheok, Raymond Liao, Koon-Seng Lim, Klara Nahrstedt

Research Collection School Of Computing and Information Systems

This paper presents a summary of the fifth International Workshop on Quality of Service (IWQOS) which was held at Columbia University in May 1997. The goal of this three-day meeting was to foster interaction between researchers active in the area of Quality of Service(QOS) research, to reflect on past experiences and lessons learnt, and to discuss future QOS challenges. To reflect this goal, this year's workshop included a hot program made up of (i) a keynote address on "Programming Telecommunications Networks"; (ii) panels addressing "QOS for Distributed Object Computing Middleware --- Fact or Fiction?" and "Reservations about Reservations"; (iii) a …

Dynamic Load Distribution In Mist, K. Al-Saqabi, R. M. Prouty, Dylan Mcnamee, Steve Otto, Jonathan Walpole

Computer Science Faculty Publications and Presentations

This paper presents an algorithm for scheduling parallel applications in large-scale, multiuser, heterogeneous distributed systems. The approach is primarily targeted at systems that harvest idle cycles in general-purpose workstation networks, but is also applicable to clustered computer systems and massively parallel processors. The algorithm handles unequal processor capacities, multiple architecture types and dynamic variations in the number of processes and available processors. Scheduling decisions are driven by the desire to minimize turnaround time while maintaining fairness among competing applications. For efficiency, the virtual processors (VPs) of each application are gang scheduled on some subset of the available physical processors.

Measurement Of The Transverse Spin Correlations In The Decay Z → Τ+Τ-, Barate, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

A measurement of the transverse-transverse, CTT, and transverse-normal CTN, τ spin correlations in the decay Z0 → τ+ τ− is presented based on the aplanarity angle of the decay products of both taus. Based on 80 pb−1 of data collected by ALEPH[1] in 1992, 1993 and 1994 on the peak of the Z resonance, the results are: CTT = 1.00 ± 0.14(stat) ± 0.04(syst), CTN =−0.08 ± 0.14(stat) ± 0.02(syst). These values are in agreement with the Standard Model predictions, CTT = 0.989 and CTN = 0.

Resuspension And Transport Of Fine Sediments By Waves, Chiang C. Mei, She-Jun Fan, Kang-Ren Jin

OES Faculty Publications

Although waves are the primary cause of sediment resuspension in the nearshore zone, in existing theoretical models, long-scale currents induced by the mean wind are often taken to be the only agent for the diffusion and convection of resuspended sediments. We present here theoretical examples where waves play a direct role in all aspects of sediment transport. Details are given for the simple case where only waves are present; the wave-induced current and diffusivity are shown to be no less important than similar factors in the wind-driven current. Hence, in a comprehensive model, one should include not only the current …

Semiclassical Formula For Oscillator Strengths In Atomic Spectra, V. Kondratovich, John B. Delos

Arts & Sciences Articles

A simple semiclassical formula is given for the oscillator strengths of high Rydberg states of a hydrogen atom in an electric field. The oscillator strength of a state is proportional to the square of the function representing the quantum angular distribution of outgoing waves, evaluated at the classical angle of ejection from the atom that sends the electron into a semiclassically quantized eigentrajectory. The formula gives an interpretation of the envelopes of Stark manifolds in photoabsorption spectra; it is in good agreement with quantum calculations. The formula may also be used for other integrable or near-integrable systems.

Closed-Orbit Theory And The Photodetachment Cross Section Of H- In Parallel Electric And Magnetic Fields, Aaron D. Peters, Charles Jaffé, J. B. Delos

Arts & Sciences Articles

In this paper we obtain a simple analytic formula for the photodetachment cross section of H− in parallel electric and magnetic fields. The three-dimensional semiclassical approximation predicts oscillations in the spectrum and correlates these oscillations with closed classical orbits. The cylindrical symmetry of the Hamiltonian produces some interesting effects. In particular, at boundary energies the semiclassical approximation fails as a focused cusp approaches the origin.

Quantum Manifestations Of Bifurcations Of Closed Orbits In The Photoabsorption Spectra Of Atoms In Electric Fields, J. Gao, John B. Delos

Arts & Sciences Articles

The methods developed in the preceding paper (paper II) are used to construct a wave function near a bifurcation of classical orbits of an atomic electron in an electric field. A formula for the recurrence strength near the bifurcation is derived and compared with experimental measurements.

Fabrication And Evaluation Of Boron-Doped Cvd Diamond Microelectrodes, Song Pang

Chemistry & Biochemistry Theses & Dissertations

The electrochemical behavior of boron-doped diamond microelectrodes has been studied in acetonitrile solutions containing two redox couples using cyclic voltammetry. One test system is 1-2.5 mM ferrocene, containing 0.1 M Tetrabutyl ammonium hexafluorophosphate (TBAH). This well-known reversible redox system involves only one electron transfer with little or no change in the solvation sphere and no breakage/formation of chemical bonds. Another test system is a 1 mM S₂Mo₁₈0₆₄^4- solution containing 0.1 M HCIO₄. This is one of the most complicated redox systems. In the presence of acid, electrons are usually transferred consecutively and …

Specification And Verification Of Generic Cell Rate Algorithms In Pvs, Huseyin Ozgungor

Electrical & Computer Engineering Theses & Dissertations

Formal verification methods have been considered as a powerful complementary approach to define standards and to prove correctness of the systems. In this work, formal specification of Generic Cell Rate Algorithms are defined and proved. The specification process enables standardization for constructing Generic Cell Rate Algorithms. Standardization is an important process in the Asynchronous Transfer Mode (ATM) networks. By employing formal methods, the necessary standards could be constructed to allow different algorithms to be employed which still meet system requirements. Those system requirements are quantified in the Quality of Service (QOS).

Congestion management is a vital concept for networks in …

Changes In Reproductive Morphology And Physiology Observed In The Amphipod Crustacean, Melita Nitida Smith, Maintained In The Laboratory On Polluted Estuarine Sediments, John T. Tanacredi Ph.D., B. Borowsky, P. Aitken-Ander

Faculty Works: CERCOM (1977-2016)

An earlier study showed that the amphipod crustacean Melita nitida Smith maintained on sediments dosed with waste crankcase oil developed physiological and morphological abnormalities. Most notably, mature females developed abnormal setae along the edges of their brood plates. The present study was conducted to determine whether similar abnormalities might be induced in animals maintained on polluted field sediments containing petroleum by-products among other toxic substances. In the laboratory, heterosexual pairs were maintained on three sediments taken from Jamaica Bay (New York) plus one control sediment and one toxic substratum (Ulva lactuca (L.) thalli). The results mirrored the results of …

Mark-Recapture Creel Survey And Survival Models, Shampa Saha

Mathematics & Statistics Theses & Dissertations

In this dissertation, we consider a model based approach to the estimation of exploitation rate of a fish population by combining mark-recapture procedures with a creel survey. We also consider the analysis of a proportional hazards survival model for randomly censored observations, known as the Koziol-Green model. The model assumes that the lifetime survivor function is a power of the censored time survivor function.

In Chapter 2, we introduce the model based approach to the estimation of the exploitation rate of a fish population by combining mark-recapture procedures with a creel survey. We assume that in the beginning of a …

A Synthesized Methodology For Eliciting Expert Judgment For Addressing Uncertainty In Decision Analysis, Richard W. Monroe

Engineering Management & Systems Engineering Theses & Dissertations

This dissertation describes the development, refinement, and demonstration of an expert judgment elicitation methodology. The methodology has been developed by synthesizing the literature across several social science and scientific fields. The foremost consideration in the methodology development has been to incorporate elements that are based on reasonable expectations for the human capabilities of the user, the expert in this case.

Many methodologies exist for eliciting assessments for uncertain events. These are frequently elicited in probability form. This methodology differs by incorporating a qualitative element as a beginning step for the elicitation process. The qualitative assessment is a more reasonable way …

The Use Of Operator Regularization In The Computation Of Effective Field Theories, Jeffrey M. Hersh

Physics Theses & Dissertations

Current methods of computing low-energy effective field theories while being accurate are extremely cumbersome co implement. Operator regularization provides a way to calculate any desired effective field theory avoiding the tediousness of previous methods. This technique is shown to be an effective method in explicitly calculating the 1_/mheavy corrections that match an original full theory to its low-energy effective counterpart. This is demonstrated up to two loop order for the case of a charged two field θ{4}{4} theory as well as up to one loop order for the Higgs sector of the Minimal Supersymmetric Model. Additionally, the renormalization …

High-Order Finite-Difference Schemes And Their Application To Computational Acoustics, Joe Leo Manthey

Mathematics & Statistics Theses & Dissertations

The primary focus of this study is upon the numerical stability of high-order finite-difference schemes and their application to duct acoustics. Since acoustic waves are known to be non-dissipative and non-dispersive, high-order schemes are favored for their low dissipation and low dispersion relative to the low-order schemes. The primary obstacle to the the development of explicit high-order finite-difference schemes is the construction of boundary closures which simultaneously maintain the formal order of accuracy and the numerical stability of the overall scheme. In this thesis a hybrid seven-point, fourth-order stencil for computing spatial derivatives is presented and the time stability is …

The Study Of Wave-Blocking And Current Effects On Nonlinear Interactions Of Shallow-Water Waves Using Advanced Boussinesq Models, Qin Chen

Civil & Environmental Engineering Theses & Dissertations

The first part of this work focuses on the derivation of enhanced Boussinesq-type equations for the combined motion of waves and currents in shallow water areas.

The strategy proposed in this work is to couple two known methods which are the sponge layer concept suitable for short waves and Sommerfeld radiation condition for currents. This coupling method provides satisfactory non-reflective boundaries for the simulation of fully coupled wave/current motion as demonstrated by the numerical experiments. We verify the model against the well known solutions based on the existing theories and good agreement has been observed. The numerical results confirm the …

Reverse Engineering Of Aircraft Wing Data Using A Partial Differential Equation Surface Model, Jacalyn M. Huband

Mathematics & Statistics Theses & Dissertations

Reverse engineering is a multi-step process used in industry to determine a production representation of an existing physical object. This representation is in the form of mathematical equations that are compatible with computer-aided design and computer-aided manufacturing (CAD/CAM) equipment. The four basic steps to the reverse engineering process are data acquisition, data separation, surface or curve fitting, and CAD/CAM production. The surface fitting step determines the design representation of the object, and thus is critical to the success or failure of the reverse engineering process. Although surface fitting methods described in the literature are used to model a variety of …

Comparison Of The Dichlorination Of Organic N-Chloramines By Caroate And By Bisulfite: A Kinetic Study, Said H. Lubbad

Chemistry & Biochemistry Theses & Dissertations

Bisulfite is commonly used to dechlorinate chlorinated municipal wastewater. However, several studies suggest that bisulfite is not effective in dechlorinating N-chlorinated amino components of wastewater. The purpose of this study was to investigate the effectiveness of an alternate dechlorinating agent, caroate (peroxysulfate), and to compare its rate of dechlorination of three different types of chloramines with that of bisulfite.

Four N-chlorinated amino compounds were investigated: N-chlorodiethylamine, N­ chloroalanylphenylalanine, N-chloroglycylphenylalanine, and N-[2-(N'-chloroimino)­ propanoyl]phenylalanine. These compounds were selected from different families of N­ chloramines to study the effect of structure on dechlorination by both caroate and bisulfite. At pH …

Speciation Of Selenium In Serum, Alice Tsapayi-Musapatike

Chemistry & Biochemistry Theses & Dissertations

We investigated the separation of selenoprotein P and extracellular (serum) glutathione peroxidase using a concanavalin A affinity column. We were able to show that the method does not adequately separate serum glutathione peroxidase from selenoprotein P because human glutathione peroxidase binds strongly to the column. We also found that albumin can interfere with measurement serum of glutathione peroxidase activity when hydrogen peroxide is used as the substrate. When t-butyl hydroperoxide was used as the substrate, less than 10% of the measured activity was due to the presence of albumin. We also found that the pH of the elution buffer plays …

Systematics Of The Freshwater Amphipod Genus Crangonyx (Crangonyctidae) In North America, Jun Zhang

Biological Sciences Theses & Dissertations

The systematics of the amphipod genus Crangonyx of North America (north of Mexico) is revised, based on available collections (ca. 2240) and literature dealing with the genus. A grand total of 42 North America species of Crangonyx are recognized in the present study, 24 of them new to science. All species are described or redescribed and figured, utilizing external morphological features. Keys to both species groups and individual species are given. Phylogenetic trees are built using computer programs (PAUP, Hennig86, MacClade) based on 26 characters. Wagner parsimony produced 18 parsimonious trees and Fitch parsimony produced 45 trees. The consensus tree …

Evaluation Of Solid Phase Extraction Followed By Supercritical Fluid Elution Of Semi-Volatile Organic Compounds In Toxicity Characteristic Leachates, William Edward Corl Iii

Chemistry & Biochemistry Theses & Dissertations

The Environmental Protection Agency (EPA) developed the toxicity characteristic leaching procedure (TCLP) to determine the potential for unknown wastes to leach haz.ardous constituents into the environment. Methods currently being used for the extraction of semi-volatile organic compounds from aqueous TCLP leachates involve acid/base partitioning into methylene chloride. The concentrated extract is then analyzed by gas chromatography/mass spectrometry (GC/MS). The methods are either timeconsuming or labor intensive and they generate significant volumes of haz.ardous wastes themselves. Considering the haz.ards and disposal costs of methylene chloride wastes, great interest has been elicited by the EPA in other extraction techniques which would reduce …

Stomach Content Analysis Of Stranded Bottlenose Dolphins, Tursiops Truncatus, In Virginia, 1987-1996, John Mcgurk

Biological Sciences Theses & Dissertations

I examined the stomach contents from 94 bottlenose dolphins, Tursiops truncatus, that were stranded along the Virginia coastline from 1987 through 1996. Samples from 1987 through 1991 were obtained from the National Museum of Natural History (NMNH) and samples from 1992 through 1996 were collected by the Virginia Marine Science Museum (VMSM) Stranding Team. Prey species were identified using fish otoliths and cephalopod beaks.

The dolphins examined fed on 23 species of fish and one genus of cephalopods. The primary prey species was Atlantic croaker (Micropogonias undulatus); secondary species were weakfish (Cynoscion regalia), spot (Leiostomus xanthurus), silver perch (Bairdiella chrysoura), …

An Automated Robot Calibration System, P. Robinson, P. Orzechowski, P. James, Caroline Lubert

Caroline P Lubert

No abstract provided.

Applications Of Geographic Information Systems, Remote-Sensing, And A Landscape Ecology Approach To Biodiversity Conservation In The Western Ghats, Shaily Menon, Kamaljit S. Bawa

Shaily Menon

The mountains along the west coast of peninsular India, the Western Ghats, constitute one of the unique biological regions of the world. Rapidly occurring land-cover and land-use change in the Western Ghats has serious implications for the biodiversity of the region. Both landscape changes as well as the distribution of biodiversity are phenomena with strong spatial correlates. Recent developments in remote-sensing technology and Geographic Information Systems (GIS) allow the use of a landscape ecology and spatial analysis approach to the problem of deforestation and biodiversity conservation in the Western Ghats. Applications of this approach include analyses of land-cover and land-use …

Features Of The Photon Statistics Of Two Coupled Electromagnetic Field Modes Under The Conditions Of Strong Mode Coupling, Mikhail E. Veisman, Serguei Y. Kalmykov

Serge Youri Kalmykov

The probabilities of transitions between the Fock states of two electromagnetic field modes under the influence of coupling between modes of finite duration are investigated. It is shown that the transition probability is a strongly oscillating function of the mode numbers of the photons. Under conditions in which the coupling frequency exceeds the geometric mean of the mode frequencies (strong coupling), large numbers of photons are excited in the mode with the lower frequency. The excitation of a two-dimensional radiation field oscillator and the ‘‘red’’ symmetry of the transition probabilities can be attributed to instability of the classical two-dimensional oscillator …

Integrating Research Into The Core Curriculum - A Case Study, Erika Rogers

Computer Science and Software Engineering

No abstract provided.

Agent Tcl: A Flexible And Secure Mobile-Agent System, Robert S. Gray

Dartmouth College Ph.D Dissertations

A mobile agent is an autonomous program that can migrate under its own control from machine to machine in a heterogeneous network. In other words, the program can suspend its execution at an arbitrary point, transport itself to another machine, and then resume execution from the point of suspension. Mobile agents have the potential to provide a {\em single, general framework} in which a wide range of distributed applications can be implemented efficiently and easily. Several challenges must be faced, however, most notably reducing migration overhead, protecting a machine from malicious agents (and an agent from malicious machines), and insulating …