Physical Sciences and Mathematics Commons^™

Comment On “Electronic Structure Of Insulating Salts Of The-(Bedt-Ttf Family Studied By Low-Temperature Specific-Heat Measurements”, Nathanael Fortune, Yu V. Sushko

Physics: Faculty Publications

Recently reported specific-heat measurements by Nakazawa and Kanoda between 20 and 50 K show no evidence for an expected antiferromagnetic ordering transition in the quasi-two-dimensional (2D) molecular conductor (Formula presented)-(BEDT-TTF)(Formula presented)Cu[N(CN)(Formula presented)]Cl [Y. Nakazawa and K. Kanoda, Phys. Rev. B 53, R8875 (1996)]. Although the absence of an observable transition was taken as evidence for 2D short-range ordering at elevated temperatures, even a small increase in pressure from the application of the grease used to mount the sample would shift this magnetic transition below 20 K. In their paper, Nakazawa and Kanoda erroneously assume that pressure-induced effects can be ruled …

How Much Ecological Information Is Preserved In Fossil Coral Reefs And How Reliable Is It?, B. J. Greenstein, H. Allen Curran

Geosciences: Faculty Publications

The coral reef fossil record is the exclusive database from which analyses of the response of coral communities to environmental change over geological time scales may be gauged. However, few studies have attempted to ascertain whether the reef fossil record is a reasonably accurate representation of a once living coral community. To address this issue, we have performed a systematic comparison of the taxonomic composition and diversity present in exposure of Pleistocene patch reef and reef tract facies found in the Bahamas to that observed for life and death assemblages currently present in analogous modern reefs of the Florida Keys. …

Ichnology Of An Intertidal Carbonate Sand Flat: Pigeon Creek, San Salvador Island, Bahamas, H. Allen Curran, Austin B. Williams

Geosciences: Faculty Publications

Reprinted from: James L. Carew (ed.), May 30–June 3, 1996, Proceedings of the 8th Symposium on the Geology of the Bahamas and Other Carbonate Regions: San Salvador, Bahamian Field Station.

Bahamian Sangamonian Coral Reefs And Sea-Level Change, Brian White, H. Allen Curran, Mark A. Wilson

Geosciences: Faculty Publications

Reprinted from James L. Carew (ed.) May 30–June 3, 1996, Proceedings of the 8th Symposium on the Geology of the Bahamas and Other Carbonate Regions: Bahamian Field Station, San Salvador, Bahamas.

The Development And Use Of The Secure Electronic Transaction (Set) Protocol On The Internet, Damon James Whyte

Theses : Honours

While still in its infancy, Electronic Commerce is growing at an exponential rate each year (Walson, 1997. p.53). Although few doubt that such growth will only continue in years to come, many people still have serious reservations about the levels of security offered by currently available applications for conducting such trade. This thesis identifies some of the key areas of concern regarding Electronic Commerce on the lnternet, and looks at the ways in which the Secure Electronic Transaction (SET) model, proposed by Mastercard and Visa, succeeds or fails in addressing these concerns. It identifies and describes the key dements and …

Dichlorobis[1-Methyl-3-(Prop-2-Enyl)Imidazole-2(3h)-Thione-S]Zinc(Ii), Daniel J. Williams, Tuan A. Ly, Jeffrey W. Mudge, William T. Pennington, George L. Schimek

Faculty Articles

The title compd. is monoclinic, space group P21/n, with a 14.0082(8), b 10.803(1), c 14.581(1) Å, and β 116.625(8)°; Z = 4, dc = 1.50; R = 0.043,Rw = 0.044 for 1935 reflections. The crystal structure shows a discrete mol. structure with tetrahedral geometry around the Zn ion. The mean Zn-Cl and Zn-S distances are 2.259(7) and 2.372(4) Å, resp. Bond angles around the Zn ion range from 102.8(1) to 113.7(1)°. Ring distances and angles in the ligand compare favorably with literature values of analogous compds., and the mean C-S bond distance of 1.71(1) Å is close to the av. …

Petrogenesis Of Mid-Proterozoic Granitic Magmas: Examples From Central And West Texas, Diane R. Smith, C. Barnes, W. Shannon, R. Roback, E. James

Earth and Environmental Geosciences Faculty Research

Circa 1.1 Ga granitic magmatism in Texas was manifested as two compositional groups: (1) the 1.12 Ga Red Bluff granitic suite in west Texas; and (2) 1.12-1.07 Ga granites of the Llano uplift of central Texas. Both suites share some characteristics typical of 'anorogenic' granites (e.g. potassium- and iron-rich bulk compositions, Fe-rich hydrous silicates, emplacement conditions involving low oxygen fugacities and water contents) and exhibit similar isotopic characteristics. However, rock associations, mineral chemistries, and trace element compositions of the two suites are distinct and no single petrogenetic model for the two suites is possible.

The Red Bluff granitic suite includes …

Eigenfunction And Harmonic Function Estimates In Domains With Horns And Cusps, Michael Cranston, Yi Li

Mathematics and Statistics Faculty Publications

No abstract provided.

Preparation Of Powder Precursors And Evaporation Of Photoconductive Indium Sulfide Films, Chris Barber, Robert Engelken, Brandon Kemp, Wasim Aleem, Imran Khan, Chris Edrington, Michael Buck, Clayton Workman, Anup Thapa, Tom Jakobs

Journal of the Arkansas Academy of Science

We have demonstrated significant photoconductance in indium sulfide thin films prepared by thermal vacuum evaporation ofIn2$3 powders synthesized in-house by chemical precipitation ofInCl3 or In(CH3COO)3, and (NH4)2S or Na2S. The Delta G lambda/Gdark values have been as high as 0.1 in the initial unoptimized films. Excess sulfur (via a mixture of polysulfide and sulfide ions in the synthesis bath) appears to be important in achieving reproducible and large photoconductivities. In2S3 is particularly attractive as a lower toxicity alternative to CdS in optoelectronic applications such as photovoltaic and photoconductive cells.

Coplanarity Test For Selecting A Pair Of Charged-Particle Tracks Resulting From A Single Neutral-Particle Decay, Edwin S. Braithwaite, Wilfred J. Braithwaite

Journal of the Arkansas Academy of Science

It is hard to determine directly the position of a neutral subatomic particle, but when such a particle decays into a pair of charged particles, it is easy to determine the positions of the charged decay particles and thereby infer the position of the parent particle at the time of its decay. A minimum of two coordinate points for each of the two decay particles is needed to reconstruct the position of the parent vertex. The mathematics of the reconstruction process is inherently interesting, and it can be used to demonstrate to students the utility of some of the most …

Electron Shock Waves: Effect Of Current On Electron Temperature And Density, Mostafa Hemmati, Mathues Shane Doss

Journal of the Arkansas Academy of Science

In our attempt to find analytical solutions for breakdown waves, we employ a set of three-component fluid equations. In addition to reporting the method of integration of electron fluid dynamical equations through the dynamical transition region (sheath region), the wave profile for ionization rate, electron number density and electron temperature inside the sheath will be discussed. Also, the effect of the current on electron temperature, electron number density and ionization rate will be reported.

Acidity Studies Of Deuterated Acids And Bases Commonly Used As Buffers In Nmr Studies, Rose M. Mcconnell, Walter E. Godwin, Brant Stanley, M. Shane Green

Journal of the Arkansas Academy of Science

Structure based drug development is currently considered to be an important strategy for drug discovery. This strategy requires that critical knowledge of the three dimensional binding site on receptor molecules be known. NMR studies are frequently employed to ascertain important structural data on individual proteins as well as complexes of proteins with ligands. Deuterium labeled acids and bases are frequently used as buffers in deuterium oxide solutions for NMR studies on the structural conformations of bioactive molecules. Since pH is an important factor in any study of the conformational and stereochemical aspects of biologically active molecules, deuterated buffers are an …

Artificial Neural Networks Used To Predict Electrical Properties Of Polymers, Sanjay K. Mitra, Qing Luo, Jerry A. Darsey

Journal of the Arkansas Academy of Science

The ability to predict properties of molecules prior to their synthesis can be of great importance in optimizing their design. Substantial savings in time as well as cost can be achieved if some desired properties can be predicted prior to the synthesis of the molecule. The outer orbitals of a molecule are primarily responsible for many different properties of the molecules. These outer orbital parameters can be utilized by an intelligent computing system like an Artificial Neural Network to extract necessary knowledge about the properties of the molecule. An Artificial Neural Network was trained to extract electrical parameters of several …

Discovery Of Fossil Cretaceous Bird In Southwest Arkansas, Leo Carson Davis, Kathie Harris

Journal of the Arkansas Academy of Science

No abstract provided.

New Studies Of Polyfuran And Polymers Of 3-Substituted Furan Rings, Rose M. Mcconnell, Walter E. Godwin, Bradley Phillips

Journal of the Arkansas Academy of Science

No abstract provided.

Reductive Dechlorinatin Of A 2-Chloronicotinic Acid Under Finkelstein Conditions, Frank L. Setliff, Leslie B. Coop

Journal of the Arkansas Academy of Science

No abstract provided.

Monotone Iterations For Differential Equations With A Parameter, Tadeusz Jankowski, V. Lakshmikantham

Mathematics and System Engineering Faculty Publications

Consider the problem {y′(t)=f(t,y(t),λ),t∈J=[0,b],y(0)=k0,G(y,λ)=0. Employing the method of upper and lower solutions and the monotone iterative technique, existence of extremal solutions for the above equation are proved.

Sagebrush (Artemisia Tridentata) Restoration In Altered Sage Grouse (Centrocercus Urophasianus) Habitat Of The Yakima Training Center In Central Washington, Margaret Ann Pounds

All Master's Theses

The restoration of sagebrush at the Yakima Training Center was studied because it was determined that military training was altering the condition of sage grouse habitat, potentially having a negative impact on the sage grouse population of the installation. The management of sage grouse and its habitat on YTC are a priority for the U.S. Army. The objectives of this study were to identify the issues relevant to sage grouse and the restoration of its habitat on the training facility, to investigate sagebrush restoration techniques, and to make management recommendations based upon this study. Results of this study indicate that …

Keyboardless Visual Programming Using Voice, Handwriting, And Gesture, Jennifer Leopold, A. Ambler

Computer Science Faculty Research & Creative Works

Visual programming languages have facilitated the application development process, improving our ability to express programs, as well as our ability to view, edit and interact with them. Yet even in programming environments, productivity is restricted by the primary input sources: the mouse and the keyboard. As an alternative, we investigate a program development interface which responds to the most natural human communication technologies: voice, handwriting and gesture. Speech- and pen-based systems have yet to find broad acceptance in everyday life because they are insufficiently advantageous to overcome problems with reliability. However, we believe that a visual programming environment with a …

Timestamp-Based Approach For The Detection And Resolution Of Mutual Conflicts In Distributed Systems, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

We present a timestamp based algorithm for the detection of both write-write and read-write conflicts for a single file in distributed systems during network partitions. Our algorithm allows operations to occur in different network partitions simultaneously. When the sites from different partitions merge, the algorithm detects and resolves both read-write and write-write conflicts without taking into account the semantics of the transactions. Once the conflicts have been detected some reconciliation steps for the resolution of conflicts have also been proposed. Our algorithm will be useful in real-time systems where timeliness of operations is more important than response time (delayed commit)

Direct Finite First-Order Model Generation With Negative Constraint Propagation Heuristic, Olga Shumsky, Ralph W. Wilkerson, Fikret Ercal, William W. Mccune

Computer Science Faculty Research & Creative Works

An Automated Finite First-Order Model Generator Has Been Developed. the Problem is Viewed as a First-Order Satisfiability Problem. Most Existing Model Generators Reduce the Problem to Propositional Satisfiability by Converting the Input First-Order Clauses into Propositional Clauses. This Generator, Unlike Others, Stores the Input First-Order Clauses and Solves the Problem Directly. It Uses an Exhaustive Backtracking Algorithm with Weight-Based Splitting. a Negative Constraint Propagation is Implemented to Reduce the Number of Decision Points and Thus to Speed Up the Search. © 1997 ACM.

Measurement Of The Spectral Functions Of Vector Current Hadronic Tau Decays, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

A measurement of the spectral functions of non-strange τ vector current final states is presented, using 124 358 τ pairs recorded by the ALEPH detector at LEP during the years 1991 to 1994. The spectral functions of the dominant two- and four-pion τ decay channels are compared to published results of e + e - annihilation experiments via isospin rotation. A combined fit of the pion form factor from τ decays and e + e - data is performed using different parametrizations. The mass and the width of the ρ ±(770) and the ρ 0(770) are separately determined in order …

Improved Measurement Of The Bd0 -B̄D0 Oscillation Frequency, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

The time dependence of B0 d {B 0 d oscillations is measured by the ALEPH experiment at LEP, using three techniques, two of which are updates of previous measurements. In all cases the charge of the decaying b quark and its decay time are measured in one hemisphere of the event; the quark charge at production is tagged mainly using the opposite hemisphere. The first method uses the charge correlation between a D and a lepton in the opposite hemisphere; if no lepton is present, the produced quark charge is determined from the hemisphere charges. In the second method, the …

Measurement Of The Τ Lepton Lifetime With The Three-Dimensional Impact Parameter Method, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

A new method is presented for the measurement of the mean lepton lifetime using events in which are pair-produced and both's decay to hadrons.

Transverse Momentum Correlations In Hadronic Z Decays, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

Using data obtained with the ALEPH detector at the Z resonance, a measure based on transverse momentum is shown to exhibit a correlation between the two halves of a hadronic event which cannot be explained by energy-momentum conservation, flavour conservation, the imposition of an event axis or imperfect event reconstruction. Two possible interpretations based on existing Monte Carlo models are examined: a) ARIADNE, with the correlation forming early in the parton shower and with the transition from partons to hadrons playing only a minor part; b) JETSET, with the correlation forming at the fragmentation stage. A correlation technique based on …

Bridges To Sustainability: Business And Government Working Together For A Better Environment, Luis Gomez-Echeverri

Yale School of the Environment Bulletin Series

No abstract provided.

Focus Catchments : A New Approach To Salinity Research : National Dryland Salinity Program, Steve Porritt

Journal of the Department of Agriculture, Western Australia, Series 4

Dry/and salinity is a major threat to the resource base of many rural industries around Australia. More than 1.8 million hectares of once productive land are affected by salinity, with a further 1.6 million hectares at risk in the next 15 to 25 years in Western Australia alone. Much of the past Commonwealth and State expenditure on salinity programs and activities has been poorly targeted and coordinated. In view of this, a national dry/and salinity program that supports specific State salinity management programs has been established jointly between the Commonwealth and State government agencies.

The Upper Kent River Catchment is …

Hydrogeological And Hydrochemical Connection Between The Decatur City Spring And Crystal Lake, Benton County, Arkansas, Demetra O. Salisbury, Ralph K. Davis

Journal of the Arkansas Academy of Science

Arkansas is ranked nationally in the production of broilers, laying hens, turkey, swine and beef cattle. These animals produce large volumes of waste, which are spread on pasture land as a method of disposal, as well as a source of fertilizer, resulting in nonpoint source contamination of surface water and ground water. One area of concern includes the Decatur City Spring, which provides municipal water for the city of Decatur. A total of eight sites in the surrounding area were monitored routinely for water quality parameters, including pH, specific conductance, and nitrate-nitrogen. Water temperature and spring and lake stage were …

Table Of Contents Volume Eight, Number One, Winter 1997, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

Table of contents for the journal RISK: Health, Safety & Environment (ISSN: 1073-8673)

Academy Recommendations On The Proposed Yucca Mountain Waste Repository: Overview And Criticisms, Kristin S. Shrader-Frechette

RISK: Health, Safety & Environment (1990-2002)

Offers alternative criticism of the NAS report.