Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2001

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 2701 - 2730 of 3030

Full-Text Articles in Physical Sciences and Mathematics

The Problem Of A Viscoelastic Cylinder Rolling On A Rigid Half-Space, John Murrough Golden, G.A.C. Graham Jan 2001

The Problem Of A Viscoelastic Cylinder Rolling On A Rigid Half-Space, John Murrough Golden, G.A.C. Graham

Articles

The problem of a viscoelastic cylinder rolling on a rigid base, propelled by a line force acting at its centre, is solved in the noninertial approximation. The method used is based on a decomposition of hereditary integrals developed by the authors in previous work, and on the viscoelastic Kolosov-Muskhelishvili equations which are used to generate a Hilbert problem. In this formulation, the problem reduces to a nonsingular integral equation in space and time, which simplifies under steady-state conditions and for exponential decay materials, to algebraic form. There are also two subsidiary conditions.

In the case of a standard linear model, …


On-Road Remote Sensing Of Automobile Emissions In The Denver Area: Year 2, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman Jan 2001

On-Road Remote Sensing Of Automobile Emissions In The Denver Area: Year 2, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.


On-Road Remote Sensing Of Automobile Emissions In The Phoenix Area: Year 2, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman Jan 2001

On-Road Remote Sensing Of Automobile Emissions In The Phoenix Area: Year 2, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.


Preliminary Studies Using Remote Sensing To Evaluate I/M Effectiveness, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman Jan 2001

Preliminary Studies Using Remote Sensing To Evaluate I/M Effectiveness, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.


Computational Studies Of Regularities In Bond Dissociation Enthalpies And Interactions Of Acetylthiocholine With Solvent Molecules, Wencui Zheng Jan 2001

Computational Studies Of Regularities In Bond Dissociation Enthalpies And Interactions Of Acetylthiocholine With Solvent Molecules, Wencui Zheng

Masters Theses

This thesis reports the results of two different research projects. One project is an evaluation of the feasibility of applying constant bond dissociation enthalpy ratios to neutral molecules for which one atom is from group 13 or group 17 and the other atom is from group 16. The other project attempts to validate the proposal that the aromatic residues lining the acetylcholinesterase (AChE) gorge will induce entry of acetylthiocholine (ATCh) into the gorge in a manner similar to that of the neural transmitter acetylcholine.

A total of thirty AB2 and AB molecules have been examined, where A = B, …


Electronic Structure And Bonding In Metal Phthalocyanines, Metal=Fe, Co, Ni, Cu, Zn, Mg, M.-S. Liao, Steve Scheiner Jan 2001

Electronic Structure And Bonding In Metal Phthalocyanines, Metal=Fe, Co, Ni, Cu, Zn, Mg, M.-S. Liao, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Electronic structure and bonding in metal phthalocyanines (Metal=Fe, Co, Ni, Cu, Zn, Mg) is investigated in detail using a density functional method. The metal atoms are strongly bound to the phthalocyanine ring in each case, by as much as 10 eV. The calculated orbital energy levels and relative total energies of these D4h structures indicate that Fe and Co phthalocyanines have 3A2g and 2Eg ground states, respectively, but that these states are changed upon interaction with strong-field axial ligands. The valence electronic structures of Fe and Co phthalocyanines differ significantly from those of …


Fungi Associated With Biological Soil Crusts In Desert Grasslands Of Utah And Wyoming, Jack S. States, Martha Christensen Jan 2001

Fungi Associated With Biological Soil Crusts In Desert Grasslands Of Utah And Wyoming, Jack S. States, Martha Christensen

Canyonlands Research Bibliography

No abstract provided.


An Open Field, Char Miller Jan 2001

An Open Field, Char Miller

Pomona Faculty Publications and Research

It should have been during a similarly punishing and mercurial moment in late twentieth-century San Antonio, enveloped in a "furious storm of rain, of hail, or of snow," that I initially encountered Richard White's seminal historiographical essay. Such a convergence of art, life, and weather pattern might have defied reality, but it would have made for a fabulous narrative opening. That said, like the norther's rush, his article, which I read shortly after its publication in the August 1985 issue of the Pacific Historical Review, blew me away.


Estimating Abundance Of Galliformes: Tools And Application, Michael J. Conroy, John P. Carroll Jan 2001

Estimating Abundance Of Galliformes: Tools And Application, Michael J. Conroy, John P. Carroll

School of Natural Resources: Faculty Publications

A large number of techniques are available for assessing populations of vertebrates. However, application of many of those techniques to Galliformes is hampered by a variety of constraints. These problems are often magnified by poor understanding of the biology of many species of concern, and an absence of valid estimates of abundance and demographic parameters. Researchers interested in developing estimates of Galliformes populations must address a number of key issues before collecting field data, to avoid biases in the resulting population estimates. General guidance exists for the identification of appropriate population estimation techniques, and a dichotomous key has been developed …


The Synthesis Of 2-Indenylphenols: Potential Ligands For Transition Metals, Yoon Jae Kim Jan 2001

The Synthesis Of 2-Indenylphenols: Potential Ligands For Transition Metals, Yoon Jae Kim

Masters Theses

The syntheses of 2-(2-indenyl)-phenol and 2-(1-indenyl)-phenol via a three-step sequence have been developed. In the first steps of the sequence, a Grignard reagent formed from 2-iodoanisole or 2-bromoanisole reacted with 1-indanone or 2-indanone in yields that ranged from 11.3% to 67.2%. The second step consisted of acid-catalyzed dehydration of the alcohol formed in step 1 to make a 2-inenyl anisole; yields in the second step were 45.2% to nearly quantitative. Finally, demethylation of the 2-indenyl anisole was achieved with AlBr3 in ethanethiol in yields ranging from 52.9% to 0 %. Each product was characterized by 1H and 13 …


The Reactivity Of Boron And Aluminum Compounds With Silica Gel Surfaces, Jeannine M. Christensen Jan 2001

The Reactivity Of Boron And Aluminum Compounds With Silica Gel Surfaces, Jeannine M. Christensen

Masters Theses

The unmodified silica gel surface contains isolated silanols, vicinal silanols, and siloxane species. Silica gels can be thermally and/or chemically treated to obtain a desired surface. Hexamethyldisilazane (HMDS) was used to chemically modify the silica gel to obtain a surface that contains vicinal silanol groups and siloxane species. The silica gel was thermally treated at 600°C to create a surface that contains isolated silanols and siloxane species. Four types of silica gels (unmodified, 600°C, HMDS and 600°C/HMDS) were reacted with three boron compounds. The boron compounds used were boron trichloride (BCl3), triethyl borane (B(CH2CH3) …


Computational Studies Of Constant Bond Dissociation Enthalpy Ratios And Novel Structures For [H3, B, C, F]+, Le Li Jan 2001

Computational Studies Of Constant Bond Dissociation Enthalpy Ratios And Novel Structures For [H3, B, C, F]+, Le Li

Masters Theses

This thesis describes two separate computational chemistry projects. The first project is a study of constant bond dissociation enthalpy ratios, and the second project is a study of the rearrangement and fragmentation processes on the singlet potential energy surface of the [H3, B, C, F]+ system.

G2 and G2(MP2) enthalpies have been calculated for isoelectronic AB2 systems with singlet-linear, singlet-nonlinear, triplet-linear, and triplet-nonlinear electronic states and geometries, and for isoelectronic AB systems with singlet and triplet electronic states. For these systems, A = B-, Al-, Ga-, C, Si, Ge, N …


Linkage Isomers Of Tungsten Carbonyl Complexes Of Ph₂Pch₂Pphch₂Pph₂, Chaminda P. Gamage Jan 2001

Linkage Isomers Of Tungsten Carbonyl Complexes Of Ph₂Pch₂Pphch₂Pph₂, Chaminda P. Gamage

Masters Theses

The linkage isomers (CO)5W[η1-PPh2CH2PPhCH2PPh2], 1, and (CO)5 W[η1-PPh(CH2PPh2)2], 2, have been synthesized from the reaction of (OC)5W(NH2Ph) and Ph2PCH2PPhCH2PPh2. In addition, linkage isomers (CO)5W[μ-PPh2CH2PPhCH2PPh2]-W(CO)5, 3, and (CO)5W{μ-PPh2CH2PPh[W(CO)5] CH2PPh2}, 4, have been prepared. Attempts to obtain (OC)5WPPh2CH …


A Ring-Closing Strategy For The Synthesis Of Β,Γ-Unsaturated Δ-Lactones, Erbing Hua Jan 2001

A Ring-Closing Strategy For The Synthesis Of Β,Γ-Unsaturated Δ-Lactones, Erbing Hua

Masters Theses

Spiro β,γ-unsaturated δ-lactones and fused β,γ-unsaturated δ-lactones are integral to a large number of naturally occurring compounds exhibiting a diverse range of biological activity. A new synthetic route to β,γ-unsaturated δ-lactones, consisting of a three-step sequence, has been investigated for the synthesis of these kinds of pharmacological intermediates. Ring closure of a β-hydroxy acid by dehydration, providing a 4-vinyl substituted β-lactone, and its ring expansion/rearrangement are the two key steps in this protocol. The results have proved that this new method is efficient and quite expeditious. One spiro and four fused β,γ-unsaturated δ-lactones were synthesized through this protocol albeit in …


Pentacarbonyl Derivatives Of Polydentate Phosphines, Yi Zang Jan 2001

Pentacarbonyl Derivatives Of Polydentate Phosphines, Yi Zang

Masters Theses

Four phosphines (Ph2P)2C=CHPPh2, (p-tol)2PCH2P(p-tol)2, (o-tol)2PCH2P(o-tol)2, Ph2PCH2P(p-tol)2 and their pentacarbonyltungsten complexes have been prepared and studied as part of a continuous investigation of polydentate phosphines that are coordinated as monodentate ligands. The ligand, (Ph2P)2C=CHPPh2, was prepared by base-catalyzed addition of Ph2PH to Ph2PC=CPPh2. Reaction of this ligand with (OC)5WNH2Ph led to formation …


An Analysis Of Unsolvable Linear Partial Differential Equations Of Order One, Laura J. Fields Jan 2001

An Analysis Of Unsolvable Linear Partial Differential Equations Of Order One, Laura J. Fields

Inquiry: The University of Arkansas Undergraduate Research Journal

It is difficult to underestimate the importance of differential equations in understanding the physical world. These equations, involving not just simple variables like temperature, speed or mass, but also the derivatives, i.e. the rate of change of these variables, are found in nearly every branch of science. Until the mid 20th century, all such equations were thought to be solvable. This was based on the discovery by Leonard Euler that certain differential equations, called ordinary differential equations (ODEs), are indeed always solvable. While ODEs deal with simple conditions, under which some quantity changes with some other quantity and its derivatives, …


Molecular Characterization Of Cultured Perkinsus Marinus Isolates, Gwynne D. Brown Jan 2001

Molecular Characterization Of Cultured Perkinsus Marinus Isolates, Gwynne D. Brown

Dissertations, Theses, and Masters Projects

Perkinsus marinus is the causative agent of the oyster disease Dermo in the eastern oyster, Crassostrea virginica. In vitro propagation of the parasite has led to the establishment of multiple isolates by several investigators. Little work, however, has been done to characterize different isolates. In this study multiple isolates were examined for genetic and biochemical diversity. at two loci, the ITS region and the ATAN region, there was as much intra-isolate genetic variation among DNA sequences of some isolates as there was inter-isolate variation. Variation was also observed at a third loci, a subtilisin-like serine protease gene. This is the …


Use Of Pop-Up Satellite Tag Technology To Estimate Survival Of Blue Marlin (Makaira Nigricans) Released From Pelagic Longline Gear, David Kerstetter Jan 2001

Use Of Pop-Up Satellite Tag Technology To Estimate Survival Of Blue Marlin (Makaira Nigricans) Released From Pelagic Longline Gear, David Kerstetter

Dissertations, Theses, and Masters Projects

No abstract provided.


Spatial And Temporal Variability Of Physical And Biological Mixing In The York River Subestuary, Tara A. Kniskern Jan 2001

Spatial And Temporal Variability Of Physical And Biological Mixing In The York River Subestuary, Tara A. Kniskern

Dissertations, Theses, and Masters Projects

No abstract provided.


The Impact Of Marine Reserves On Exploited Species With Complex Life Histories: A Modeling Study Using The Caribbean Spiny Lobster In Exuma Sound, Bahamas, William T. Stockhausen Jan 2001

The Impact Of Marine Reserves On Exploited Species With Complex Life Histories: A Modeling Study Using The Caribbean Spiny Lobster In Exuma Sound, Bahamas, William T. Stockhausen

Dissertations, Theses, and Masters Projects

Most benthic invertebrates and reef-associated fish undergo a dispersive, planktonic larval stage prior to settlement and metamorphosis into the juvenile and adult stages. In some species, settlement may be decoupled from adult abundance at local spatial scales if hydrodynamic conditions or larval behavior do not promote local retention. Similarly, spatial variability in postsettlement mortality or secondary dispersal by juveniles and adults may decouple spatial patterns of adult abundance from those of settlement. as a consequence, spatial patterns of settlement and adult abundance may be functionally related in a complex fashion. Whether biotic/environmental factors control spatial patterns of abundance may have …


Composting Of Feedlot And Dairy Manure: Compost Characteristics And Impact On Crop Yields, Galen E. Erickson, Terry J. Klopfenstein, Walker Luedtke, Mark Schroeder, Charles A. Francis, Gary Lesoing Jan 2001

Composting Of Feedlot And Dairy Manure: Compost Characteristics And Impact On Crop Yields, Galen E. Erickson, Terry J. Klopfenstein, Walker Luedtke, Mark Schroeder, Charles A. Francis, Gary Lesoing

Nebraska Beef Cattle Reports

Since 1993, approximately 17,600 tons of beef feedlot and dairy compost have been spread on 1,100 acres. Crop yields were measured to determine the impact of a one-time compost application by using no-compost check strips in large-scale production fields. Adding compost to irrigated corn, irrigated soybeans, and dryland corn acres significantly increased yields, with four-year average increases of 2.3, 1.5, and 2.7%, respectively. For all crops measured, the response to compost was greatest the first year following application and declined linearly in subsequent years. The increased yield from compost application offsets spreading costs using average prices for crops.


Microwave Ionization Of An Atomic Electron Wave Packet, Michael W. Noel, Lung Ko, T. F. Gallagher Jan 2001

Microwave Ionization Of An Atomic Electron Wave Packet, Michael W. Noel, Lung Ko, T. F. Gallagher

Physics Faculty Research and Scholarship

A short microwave pulse is used to ionize a lithium Rydberg wave packet launched from the core at a well-defined phase of the field. We observe a strong dependence on the relative phase between the motion of the wave packet and the oscillations of the field. This phase dependent ionization is also studied as a function of the relative frequency. Our experimental observations are in good qualitative agreement with a one-dimensional classical model of wave packet ionization.


A New Mechanism For Spin-Lattice Relaxation Of Heavy Nuclei In The Solid State: 207pb Relaxation In Lead Nitrate, John B. Grutzner, Kevin W. Stewart, Roderick E. Wasylishen, Michael D. Lumsden, Cecil Dybowski, Peter A. Beckmann Jan 2001

A New Mechanism For Spin-Lattice Relaxation Of Heavy Nuclei In The Solid State: 207pb Relaxation In Lead Nitrate, John B. Grutzner, Kevin W. Stewart, Roderick E. Wasylishen, Michael D. Lumsden, Cecil Dybowski, Peter A. Beckmann

Physics Faculty Research and Scholarship

No abstract provided.


On Powers Of 2 Dividing The Values Of Certain Plane Partition Functions, Darrin D. Frey, James A. Sellers Jan 2001

On Powers Of 2 Dividing The Values Of Certain Plane Partition Functions, Darrin D. Frey, James A. Sellers

Science and Mathematics Faculty Publications

We consider two families of plane partitions: totally symmetric self-complementary plane partitions (TSSCPPs) and cyclically symmetric transpose complement plane partitions (CSTCPPs). If T(n) and C(n) are the numbers of such plane partitions in a 2n × 2n × 2nbox, then

ord2(T(n)) = ord2(C(n))

for all n >= 1. We also discuss various consequences, along with other results on ord2(T(n)).


Report Of The State Nuclear Safety Advisor Submitted To The Governor And 120th Legislature As Of January 15, 2001, Paula M. Craighead Jan 2001

Report Of The State Nuclear Safety Advisor Submitted To The Governor And 120th Legislature As Of January 15, 2001, Paula M. Craighead

Maine Collection

Report of the State Nuclear Safety Advisor submitted to the Governor and 120th Legislature As of January 15, 2001

Paula M. Craighead, State Nuclear Safety Advisor, Executive Department, Maine State Planning Office, Augusta, Maine, 2001.

Contents: Introduction and Executive Summary / I. Maine Yankee Decommissioning / II. Portsmouth Naval Shipyard (PNS) / III. Low-Level Radioactive Waste (LLRW) / IV. High Level Radioactive Waste / V. Transport Routes and Safety Response / VI. Shipments / VII. Status of Federal and State Legal and Administrative Proceedings / References and Resources / Glossary


Comparison Of Student Performance And Attitude In A Lecture Class To Student Performance And Attitude In A Telecourse And A Web-Based Class, William J. Ryan Jan 2001

Comparison Of Student Performance And Attitude In A Lecture Class To Student Performance And Attitude In A Telecourse And A Web-Based Class, William J. Ryan

CCE Theses and Dissertations

Increasing numbers of students are returning to school and choosing alternatives to the lecture method of instruction. Using technology to reach students is a solution colleges and universities are evaluating and implementing with the goal of increasing enrollment and reducing the cost of instruction. This research examines the impact two technology-based delivery systems have on the student's learning experience compared with an equivalent classroom-based instructional method.

Academic institutions are being asked to respond to the rapid changes faced by the communities they serve especially as current workers return to join new students in obtaining knowledge and skills needed in today's …


Reorganizing Web Sites Based On User Access Patterns, Yongjian Fu, Mario Creado, Chunhua Ju Jan 2001

Reorganizing Web Sites Based On User Access Patterns, Yongjian Fu, Mario Creado, Chunhua Ju

Computer Science Faculty Research & Creative Works

In this paper, an approach for reorganizing Web sites based on user access patterns is proposed. The approach consists of three steps: preprocessing, page classification, and site reorganization. In preprocessing, pages on a Web site are processed to create an internal representation of the site, and page access information of its users is extracted from its server log. In page classification, the Web pages on the site are classified into two categories, index pages and content pages, based on the page access information. After the pages are classified, in site reorganization, the Web site is examined to find better ways …


Production Of A Novel Copper-Binding Ligand By Marine Synechococcus (Cyanobacteria) In Response To Toxic Concentrations Of Copper, Arunsi C. Brown, Andrew S. Gordon Jan 2001

Production Of A Novel Copper-Binding Ligand By Marine Synechococcus (Cyanobacteria) In Response To Toxic Concentrations Of Copper, Arunsi C. Brown, Andrew S. Gordon

Virginia Journal of Science

Marine Synechococcus spp. are extremely sensitive to copper toxicity. Some strains have been shown to produce high-affinity, extracellular ligands of unknown structure which form complexes with free cupric ion. They are also known to produce metallothioneins (MT) in response to cadmium and zinc stress. In the present study, marine Synechococcus PCC 73109 (Agmenellum quadruplicatum BG-1) (Van Baalen) was exposed to three concentrations of CuSO4 for various times. Size exclusion chromatography, atomic absorption spectrophotometry, and reverse phase HPLC were used to isolate an intracellular copper binding ligand of low molecular weight (< 6,500 Da). The ligand was detected after exposure to ≥ 8 μM CuSO4 for 2 hr in BG-11 medium. …


Longshore Sediment Transport As A Function Of Energy Dissipation, Ernest R. Smith, Ping Wang Jan 2001

Longshore Sediment Transport As A Function Of Energy Dissipation, Ernest R. Smith, Ping Wang

Geology Faculty Publications

Experiments to measure waves, currents, and sediment transport rate for two breaker types, plunging and spilling, were conducted in a large-scale three-dimensional physical model. It was found that there was a large difference in cross-shore distribution and total sediment transport rate between the two breaker types. Total transport rates compared to existing predictive equations. The equations generally did not predict the data well. With the exception of the Kamphuis (1991) equation, which included a dependence on wave period, the predictive equations did not differentiate between breaker types.


Data Report: Carbon Isotopic Composition Of Dissolved Co2, Co2 Gas, And Methane, Blake-Bahama Ridge And Northeast Bermuda Rise, Odp Leg 172, Walter S. Borowski, Namik Cagatay, Y Tournois, Charles K. Paull Jan 2001

Data Report: Carbon Isotopic Composition Of Dissolved Co2, Co2 Gas, And Methane, Blake-Bahama Ridge And Northeast Bermuda Rise, Odp Leg 172, Walter S. Borowski, Namik Cagatay, Y Tournois, Charles K. Paull

EKU Faculty and Staff Scholarship

Carbon isotopic data of interstitial dissolved CO2 (ΣCO2), CO2 gas, and methane show that a variety of microbial diagenetic processes produce the observed isotopic trends. Anaerobic methane oxidation (AMO) is an important process near the sulfate-methane interface (SMI) that strongly influences the isotopic composition of ΣCO2 in the sulfate reduction and upper methanogenic zones, which in turn impacts methane isotopic composition. Dissolved CO2 and methane are maximally depleted in 3C near the SMI, where C values are as light as –31.8‰ and –101‰ PDB for ΣCO2 and methane, respectively. CO2 reduction links the CO2 and methane pools in the methanogenic …