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1997

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Articles 601 - 630 of 2184

Full-Text Articles in Physical Sciences and Mathematics

Systematics Of The Freshwater Amphipod Genus Crangonyx (Crangonyctidae) In North America, Jun Zhang Jul 1997

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 …


The Study Of Wave-Blocking And Current Effects On Nonlinear Interactions Of Shallow-Water Waves Using Advanced Boussinesq Models, Qin Chen Jul 1997

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 …


Measurement Of The Transverse Spin Correlations In The Decay Z → Τ+Τ-, Barate, R.; Et Al., M. Thulasidas Jul 1997

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.


Mark-Recapture Creel Survey And Survival Models, Shampa Saha Jul 1997

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 …


The Use Of Operator Regularization In The Computation Of Effective Field Theories, Jeffrey M. Hersh Jul 1997

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 …


Correlation Of Finite Element Prediction And Experimental Measurements Of Aircraft Panel Structural Vibration, Olaf L. Storaasli Jul 1997

Correlation Of Finite Element Prediction And Experimental Measurements Of Aircraft Panel Structural Vibration, Olaf L. Storaasli

Mechanical & Aerospace Engineering Theses & Dissertations

With the rapid development of computational capabilities and the implementation of complex tools for commercial finite element programs, predicting structural dynamics and related acoustics of complex structures is presently achievable. Structural finite element modeling is a design tool widely utilized for analysis of problems of all kinds. However, high frequency vibration of complex structures, such as the reinforced aircraft panel used for this study, currently does not correlate well with experimental measurements using conventional modeling methods. An investigation into the commonly used modeling techniques as well as the new tools of commercial finite element analysis packages for the prediction of …


Speciation Of Selenium In Serum, Alice Tsapayi-Musapatike Jul 1997

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 …


Comparison Of The Dichlorination Of Organic N-Chloramines By Caroate And By Bisulfite: A Kinetic Study, Said H. Lubbad Jul 1997

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 …


A Synthesized Methodology For Eliciting Expert Judgment For Addressing Uncertainty In Decision Analysis, Richard W. Monroe Jul 1997

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 …


Native Vegetation Handbook For The Shire Of Brookton, Rod Safstrom Jul 1997

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.


Resuspension And Transport Of Fine Sediments By Waves, Chiang C. Mei, She-Jun Fan, Kang-Ren Jin Jul 1997

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 …


Integrating Research Into The Core Curriculum - A Case Study, Erika Rogers Jun 1997

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

Computer Science and Software Engineering

No abstract provided.


Study Of Laser Plasma Interactions In The Relativistic Regime, Donald Umstadter Jun 1997

Study Of Laser Plasma Interactions In The Relativistic Regime, Donald Umstadter

Donald Umstadter Publications

We discuss the first experimental demonstration of electron acceleration by a laser wakefield over distances greater than a Rayleigh range (or the distance a laser normally propagates in vacuum). A self-modulated laser wakefield plasma wave is shown to have a field gradient that exceeds that of an RF Iinac by four orders of magnitude (E ≥ 200 GV/m) and accelerates electrons with over l-nC of charge per bunch in a beam with space-charge-limited emittance (1 mm-mrad). Above a laser power threshold, a plasma channel, created by the intense ultrashort laser pulse (I~ 4 x 1018 W/cm2, …


Agent Tcl: A Flexible And Secure Mobile-Agent System, Robert S. Gray Jun 1997

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 …


Oil And Gas Map Of The Tompkinsville 30 X 60 Minute Quadrangle, Kentucky, Brandon C. Nuttall Jun 1997

Oil And Gas Map Of The Tompkinsville 30 X 60 Minute Quadrangle, Kentucky, Brandon C. Nuttall

Map and Chart--KGS

No abstract provided.


Link/Loop/Node Networks, Mark E. Gilbert Jun 1997

Link/Loop/Node Networks, Mark E. Gilbert

Honors Theses

This document is really two separate documents that have been appended together. The first is Link/Loop/Node Networks. This document describes the theory behind link/loop/node networks (LLN), as well as the basic operating instructions for the LLN Simulator (LLNS). The second document is LLN Simulator Technical Reference. This second document describes how the LLNS was constructed using Microsoft Access 2.0, as well as how the LLNS simulates LLN.


A Measurement Of The Michel Parameters In Leptonic Decays Of The Tau, R. Ammar, Kenneth A. Bloom, Cleo Collaboration Jun 1997

A Measurement Of The Michel Parameters In Leptonic Decays Of The Tau, R. Ammar, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

We have measured the spectral shape Michel parameters ρ and η using leptonic decays of the τ, recorded by the CLEO II detector. Assuming e-μ universality in the vectorlike couplings, we find ρeμ = 0.735 ± 0.013 ± 0.008 and ηeμ = 20.015 ± 0.061 ± 0.062, where the first error is statistical and the second systematic. We also present measurements for the parameters for e and μ final states separately.


Initial Polar Mfe Observation Of Substorm Signatures In The Polar Magnetosphere, H. Kawano, G. Le, C. T. Russell, G. Rostoker, T. Mukai, Harlan E. Spence Jun 1997

Initial Polar Mfe Observation Of Substorm Signatures In The Polar Magnetosphere, H. Kawano, G. Le, C. T. Russell, G. Rostoker, T. Mukai, Harlan E. Spence

Physics & Astronomy

This paper studies substorm influences in the polar magnetosphere using data from the POLAR magnetic field experiment (MFE). The POLAR spacecraft remains in the high altitude polar magnetosphere for extended periods around apogee. There it can stay at nearly constant altitude through all phases of a substorm, which was not possible on previous missions. We report such an event on March 28, 1996. Ground magnetometers monitored substorm activity, while the POLAR spacecraft, directly over the pole at (−0.8, −0.6, 8.5) RE in GSM coordinates, observed a corresponding perturbation in the total magnetic field strength. The total magnetic field first …


First Polar And 1995-034 Observations Of The Midaltitude Cusp During A Persistent Northward Imf Condition, M. Grande, J. Fennell, S. Livi, B. Kellett, C. Perry, P. Anderson, J. Roeder, Harlan E. Spence, T. Fritz, B. Wilken Jun 1997

First Polar And 1995-034 Observations Of The Midaltitude Cusp During A Persistent Northward Imf Condition, M. Grande, J. Fennell, S. Livi, B. Kellett, C. Perry, P. Anderson, J. Roeder, Harlan E. Spence, T. Fritz, B. Wilken

Physics & Astronomy

We present the first observations by Polar and 1995-034 of the mid-altitude cusp. On May 29, 1996, the Polar and 1995-034 spacecraft crossed into an extended cusp region. The region was characterized by intense fluxes of solar wind like ions in the energy range 1–10 keV that had angular distributions that showed evidence of flows and trapping. The ion composition data are combined with energetic proton observations from Polar and plasma observations from 1995-034 and DMSP satellites to examine the spatial and temporal extent and plasma characteristics of the cusp during a persistent northward IMF condition. The composition data is …


A New, Temporarily Confined Population In The Polar Cap During The August 27, 1996 Geomagnetic Field Distortion Period, Jiasheng Chen, Theodore A. Fritz, Robert B. Sheldon, Harlan E. Spence, Walther N. Spjeldvik, Joseph F. Fennell, Stefano Livi Jun 1997

A New, Temporarily Confined Population In The Polar Cap During The August 27, 1996 Geomagnetic Field Distortion Period, Jiasheng Chen, Theodore A. Fritz, Robert B. Sheldon, Harlan E. Spence, Walther N. Spjeldvik, Joseph F. Fennell, Stefano Livi

Physics & Astronomy

On August 27, 1996, a two-hour energetic heavy ion event (∼1 MeV) was detected at 8:25 UT at apogee (∼9 Re and an invariant latitude of ∼80°), by the Charge and Mass Magnetospheric Ion Composition Experiment onboard POLAR. The event, with a maximum spin averaged peak flux of ∼150 particles/(cm²-sr-s-MeV), showed three local peaks corresponding to three localized regions; the ion pitch angle distributions in the three regions were different from an isotropic distribution and different from each other. No comparable flux was observed by the WIND spacecraft. The appearance of lower energy He++ and O > +2 during the event …


Parametrically Resonant Surface Waves In A Rectangular Basin, Wu-Ting Tsai Jun 1997

Parametrically Resonant Surface Waves In A Rectangular Basin, Wu-Ting Tsai

Journal of Marine Science and Technology–Taiwan

We consider the resonant motion of a layer of fluid in a twodimensional rectangular basin forced to oscillate vertically. The equation governing the slowly-varying amplitude is derived using the multiple-scales method of perturbation analysis. The solution of the evolution equation is obtained analytitally. For steady harmonic responses, the present result compares remarkably well with available experimental measurements and is an improvement over existing third-order perturbation calculations. For unsteady (periodic) motions, the periods are computed as a function of motion amplitudes. The presence of internal resonance is discussed briefly.


Solvent-Induced Interactions Between Hydrophobic And Hydrophilic Polyatomic Sheets In Water And Hypothetical Nonpolar Water, Kenichiro Koga, Xiao Cheng Zeng, Hideki Tanaka Jun 1997

Solvent-Induced Interactions Between Hydrophobic And Hydrophilic Polyatomic Sheets In Water And Hypothetical Nonpolar Water, Kenichiro Koga, Xiao Cheng Zeng, Hideki Tanaka

Xiao Cheng Zeng Publications

Hydrophobic and hydrophilic interactions are two major intermolecular forces between hydrophobic nonpolar and hydrophilic polar sites of macromolecules or materials surfaces in solvents. To further understand these two interactions at the microscopic level, an idealized polyatomic model is devised, which includes hydrophobic, hydrophilic, and partially hydrophilic polyatomic planar square molecular sheets. The hydrophobic molecular sheet is composed of the Lennard-Jones particles while the hydrophilic molecular sheet consists of positive and negative charge sites. In the framework of the extended reference interaction site model integral equation theory the solvent-induced interactions (or the potential of mean forces) between two parallel molecular sheets …


A High Level Theoretical Investigation Of The Cyclic Hydrogen Fluoride Trimer, Gregory S. Tschumper, Yukio Yamaguchi, Henry F. Schaefer Jun 1997

A High Level Theoretical Investigation Of The Cyclic Hydrogen Fluoride Trimer, Gregory S. Tschumper, Yukio Yamaguchi, Henry F. Schaefer

Chemistry Faculty Research & Creative Works

A high-level ab initio theoretical investigation of the cyclic hydrogen fluoride trimer was carried out. The structures of the hydrogen fluoride monomer, dimer, and trimer were fully optimized at the coupled-cluster level of theory including single, double, and perturbatively applied connected triple excitations [CCSD(T)] using three large basis sets. Geometrical parameters, dipole moments, harmonic vibrational frequencies, infrared intensities, and total energies are reported for each equilibrium structure. Changes in bond lengths and shifts in HF stretching frequencies relative to the monomer, as well as the dissociation energies corresponding to various fragmentation pathways, are given for the dimer, trimer, and their …


Preparation Of Organometallic Complexed Sugars:  Hetero Diels−Alder Reactivity Of Tricarbonyl(Formyltrimethylenemethane)- Iron, Paul J. Kleindl, William A. Donaldson Jun 1997

Preparation Of Organometallic Complexed Sugars:  Hetero Diels−Alder Reactivity Of Tricarbonyl(Formyltrimethylenemethane)- Iron, Paul J. Kleindl, William A. Donaldson

Chemistry Faculty Research and Publications

No abstract provided.


Time-Based Clustering And Its Relationship With Mutual Information Theory, Charles R. Tolle Jun 1997

Time-Based Clustering And Its Relationship With Mutual Information Theory, Charles R. Tolle

Utah Space Grant Consortium

This paper re-introduces the concepts of TimeBased Clustering (TBC). Also, the ideas of oversampling and embedding time are introduced in connection with mutual information theory. These concepts are then extended through the use of the Time-Based Clustering (TBC) problem. Mutual information curves for the Rössler system are shown to match a slice through the rich cost function space spanned by the Time-Based Clustering (TBC) solution. In closing, some possible repercussions of this find are discussed.


Examination Of The Combustion Morphology Of Ziconium Carbide Using Scanning Electron Microscopy, Brian R. Newbold Jun 1997

Examination Of The Combustion Morphology Of Ziconium Carbide Using Scanning Electron Microscopy, Brian R. Newbold

Utah Space Grant Consortium

Calculation of viscous particle damping of acoustic combustion instability in solid propellant motors requires an understanding of the combustion behavior of added particles and oxides. A simple hydrogen/oxygen flame was used to ignite carefully sieved zirconium carbide particles which were impacted on slides at different levels below the burner.

Scanning electron microscopy revealed that zirconium carbide has a complex heterogeneous combustion morphology. Initially, particles are partly vitreous and crystalline with a complex surface area. Upon ignition, particles round, but soon wrinkle as zirconium oxide deposits on the surface. Such morphology information is useful to refine viscous damping calculations.


Gps Tracking For Small Sounding Rockets, Darin K. Fowers Jun 1997

Gps Tracking For Small Sounding Rockets, Darin K. Fowers

Utah Space Grant Consortium

Active areas of research often create the need for improved technology to make observations in a way that has not previously been utilized. Such is the case with middle atmospheric research. This 60 to 120 km region of the atmosphere is too low to be directly probed by satellites and too high to be probed by research airplanes or high altitude balloons. Sounding rockets are the only vehicle that can carry instruments for in situ measurements. Up until now only a few methods have been available to track the location of a sounding rocket - radar skin tracking, radio beacon …


Absolute Solar Transmittance Interferometer, Arthur W. Dybdahl Jun 1997

Absolute Solar Transmittance Interferometer, Arthur W. Dybdahl

Utah Space Grant Consortium

The University of Denver's Absolute Solar Transmittance Interferometer (ASTI) has been developed to make high-resolution infrared (TR) radiometric measurements of the incident solar radiance and irradiance at the Earth's surface. It is a research instrument that provides spectral data of high scientific interest in the short-wave infrared (SWIR) band covering 0.97 to 5.13 µm. This band contains about 20 percent of the suns incident energy, having a significant impact on global as well as regional climate. ASTI spectra are used to provide significant radiometric information describing the SWlR transmittance and absorption properties of the atmosphere. The ASTl research program and …


Flow Past Bluff Bodies, Thad S. Morton Jun 1997

Flow Past Bluff Bodies, Thad S. Morton

Utah Space Grant Consortium

More than a century ago Kirchhoff solved for the velocity distribution within an elliptical patch of uniform vorticity. That solution became the basis for all further studies of elliptical vortices and has been regarded as the only known exact solution for a steady, elliptical patch of uniform vorticity. In the present paper, an exact solution for a new elliptical patch of uniform vorticity is presented. The vortex is constructed of streamlines of constant eccentricity. By specifying a velocity distribution along either of the principle axes of the vortex, continuity between differentially-spaced streamlines provides the velocity distribution throughout the vortex. Some …


Internet Access For Instrumental Control And Data Viewing At Bear Lake Observatory, Kerry M. Nelson Jun 1997

Internet Access For Instrumental Control And Data Viewing At Bear Lake Observatory, Kerry M. Nelson

Utah Space Grant Consortium

Two departments at Utah State University have collaborated to operate an observatory near Bear Lake, Utah. The purpose of the observatory is to study various phenomena in the upper atmosphere, and houses such instruments as high-power CCD cameras, a radar system, and others. Until recently, only one instrument has had the capability of being controlled and monitored remotely. Since the other instruments do not have this capability, they must be set up and left running, only to have a person drive up to the observatory to check their operation after a given amount of time. This monitoring system is not …