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1996

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Articles 1981 - 2010 of 2437

Full-Text Articles in Physical Sciences and Mathematics

A Survey Of Hadamard Difference Sets, James A. Davis, Jonathan Jedwab Jan 1996

A Survey Of Hadamard Difference Sets, James A. Davis, Jonathan Jedwab

Department of Math & Statistics Faculty Publications

A (v, k, λ) difference set is a k-element subset D of a group G of order v for which the multiset {d1d2-1 : d1, d2D, d1d2} contains each nonidentity element of G exactly λ times. A difference set is called abelian, nonabelian or cyclic according to the properties of the underlying group. Difference sets are important in design theory because they are equivalent to symmetric (v, k, λ) designs with a regular automorphism group [L].


High-Sensitivity Absorption Spectroscopy In Fe Ii, Scott D. Bergeson, K. L. Mullman, J. E. Lawler Jan 1996

High-Sensitivity Absorption Spectroscopy In Fe Ii, Scott D. Bergeson, K. L. Mullman, J. E. Lawler

Faculty Publications

We report the first measurements of UV oscillator strengths (ƒ-values) in Fe II from a high-sensitivity absorption experiment developed at the University of Wisconsin. The accuracy of our measurements is demonstrated by our reproducing well-known ƒ-value ratios in Fe I and Fe II. The first laboratory ƒ-value measurement of the 160.845 nm transition in Fe II is presented and compared to values in the literature. While this paper focuses on Fe II, the high-sensitivity absorption method that we have developed is applicable to essentially every element in the periodic table, for both neutral and ionized species, over a broad range …


Branching Fractions And Oscillator Strengths For Fe Ii Transitions From The 3d6(5D)4p Subconfiguration, Scott D. Bergeson, K. L. Mullman, M. E. Wickliffe, J. E. Lawler Jan 1996

Branching Fractions And Oscillator Strengths For Fe Ii Transitions From The 3d6(5D)4p Subconfiguration, Scott D. Bergeson, K. L. Mullman, M. E. Wickliffe, J. E. Lawler

Faculty Publications

New experimental branching fractions and transition probabilities are reported for 56 transitions in Fe II. The branching fractions are measured with a Fourier transform spectrometer and also with a high-resolution grating spectrometer on a n optically thin hollow cathode discharge. Highly accurate experimental radiative lifetimes from the recent literature provide the normalization required to convert our branching fractions into absolute transition probabilities. Results are compared with experimental and theoretical values in the literature. Our new transition probabilities will establish the absolute scale for relative absorption oscillator strengths of vacuum ultraviolet lines measured using a new high-sensitivity absorption experiment at the …


Characterization Of Ground And Excited Electronic State Deprotonation Energies Of Systems Containing Double Bonds Using Natural Bond Orbital Analysis, J. K. Badenhoop, Steve Scheiner Jan 1996

Characterization Of Ground And Excited Electronic State Deprotonation Energies Of Systems Containing Double Bonds Using Natural Bond Orbital Analysis, J. K. Badenhoop, Steve Scheiner

Steve Scheiner

Natural bond orbital analysis is applied to the ground and excited states of a set of neutral, cationic, and anionic doubly bonded species HnC=XHn (X=C, N, O) isoelectronic with ethylene. The character of the excitation is correlated with calculated charge shifts and geometry changes upon relaxation. For these planar molecules, depopulation of the π bond or population of the π∗ antibond causes an out‐of‐plane twist or pyramidalization upon relaxation correlated to the amount of charge shift. These nonplanar distortions generally lower the energy more than changes in bond lengths and angles. Population of a σXH∗ …


The Inverse Problem Of The Calculus Of Variations For Scala Fourth Order Ordinary Differential Equations, Mark E. Fels Jan 1996

The Inverse Problem Of The Calculus Of Variations For Scala Fourth Order Ordinary Differential Equations, Mark E. Fels

Mark Eric Fels

A simple invariant characterization of the scalar fourth-order ordinary differential equations which admit a variational multiplier is given. The necessary and sufficient conditions for the existence of a multiplier are expressed in terms of the vanishing of two relative invariants which can be associated with any fourth-order equation through the application of Cartan's equivalence method. The solution to the inverse problem for fourth-order scalar equations provides the solution to an equivalence problem for second-order Lagrangians, as well as the precise relationship between the symmetry algebra of a variational equation and the divergence symmetry algebra of the associated Lagrangian.


Retention And Separation Behaviour Of Chloropyrifos And Other Water Pollutants Using Polyurethane Foams, Rashed Saleh Al-Mehrazi Jan 1996

Retention And Separation Behaviour Of Chloropyrifos And Other Water Pollutants Using Polyurethane Foams, Rashed Saleh Al-Mehrazi

Theses

Heavy metals and pesticides represent a class of man-made environmental pollutants which also occur naturally in the environment. The presence of these pollutants in the industrial and agricultural wastewaters often represents a risk to the environment. Investigation of these species in the water is an important aspect of environmental pollution as human activities contributed to the progressive increase in the concentration of these compounds in the environmental as well as aquatic systems. Therefore, identification and removal (or reduction) of these species to an acceptable concentration are of prime importance.

The analytical utility of unloaded open-cell polyurethane foams and foams immobilizing …


Comparative Study Of Some Physiological And Behavioral Responses To Feed And Water Deprivation In Camels, Sheep And Goats, Huda Mohammed Shaheen Jan 1996

Comparative Study Of Some Physiological And Behavioral Responses To Feed And Water Deprivation In Camels, Sheep And Goats, Huda Mohammed Shaheen

Theses

The aim of the study was to compare some physiological and biochemical responses in camels, sheep and goats when subjected to various periods of food and water deprivation. Another purpose of the study was to examine the feeding and drinking behaviour of dehydrated and starved animals when provided with food and water simultaneously. The study was performed at the Faculty of Agricultural Sciences Farm, University of United Arab Emirates, Al-Ain.

Animals were deprived of water and food for various periods; feed and water were withheld 2, 4 or 6 days in camels and 1, 2 or 3 days for sheep …


Paracompact Subspaces In The Box Product Topology, Peter Nyikos, Leszek Piatkiwicz Jan 1996

Paracompact Subspaces In The Box Product Topology, Peter Nyikos, Leszek Piatkiwicz

Faculty Publications

No abstract provided.


Condensation Of Supersaturated Vapors Of Hydrogen Bonding Molecules: Ethylene Glycol, Propylene Glycol, Trimethylene Glycol, And Glycerol, David B. Kane, M. Samy El-Shall Jan 1996

Condensation Of Supersaturated Vapors Of Hydrogen Bonding Molecules: Ethylene Glycol, Propylene Glycol, Trimethylene Glycol, And Glycerol, David B. Kane, M. Samy El-Shall

Chemistry Publications

The critical supersaturations required for the homogeneous nucleation (rate of 1 drop cm−3 s−1) of ethylene glycol, propylene glycol, trimethylene glycol and glycerol vapors have been measured over wide temperature ranges (e.g., 280–400 K) using an upward thermal diffusion cloud chamber. At lower temperatures the experimental nucleation rates are much higher than the predictions of the classical nucleation theory. Glycerol shows the best agreement between experiment and theory in the temperature range of 340–370 K. An apparent increase in the critical supersaturation of glycerol is observed with increasing carrier gas (helium) pressure and this effect is more …


Space-Based Genetic Cryoconservation Of Endangered Species, Michael Noah Mautner Jan 1996

Space-Based Genetic Cryoconservation Of Endangered Species, Michael Noah Mautner

Chemistry Publications

Genetic materials of endangered species must be maintained, for cryoconservation, permanently near liquid nitrogen temperatures below 77 K. Due to the instability of human institutions, permanent safety is best provided at storage sites that maintain passively the needed low temperatures, and provide barriers to access. The required conditions are available in permanently shaded polar lunar craters with equilibrium temperatures of 8 to 40 K, on the moons of Saturn, and unshielded storage satellites. A genetic depository can be incorporated readily into planned lunar programmes.


Wave Profile For Proforce Current Bearing Waves, Mostafa Hemmati, Steven Young Jan 1996

Wave Profile For Proforce Current Bearing Waves, Mostafa Hemmati, Steven Young

Journal of the Arkansas Academy of Science

A complete wave profile for proforce style of breakdown waves with a current behind the shock front is discussed. The solution of the electron fluid dynamical equations in the sheath region for proforce current bearing waves conforms with the expected conditins for the values of the dynamical variables at the trailing edge of the wave. The wave profile for electric field and electron velocity, temperature, and number density are presented.


Completion Report: Arkansas State Pesticides In Ground Water Monitoring Project Phase V: Vulnerable Areas In Jackson, Monroe, Lawrence And Lonoke Counties, T. Nichols, P. Vendrell, K. Steele, H. D. Scott, C. Armstrong Jan 1996

Completion Report: Arkansas State Pesticides In Ground Water Monitoring Project Phase V: Vulnerable Areas In Jackson, Monroe, Lawrence And Lonoke Counties, T. Nichols, P. Vendrell, K. Steele, H. D. Scott, C. Armstrong

Technical Reports

In 1996, sixty-seven water samples were drawn from 65 wells, including 62 new wells and 3 wells sampled previously . One Woodruff County well and two Pulaski County wells were resampled. Thirty-two samples were drawn from 30 wells in Monroe County (well #1 was sampled 3 times during this phase) . Ten wells in Jackson County, 12 wells in Lawrence County and 10 wells in Lonoke were also tested (Figures 1-5) . With the completion of Phase V, the number of wells tested has risen to 231 with a total of 258 samples analyzed . Initially, the wells were tested …


Landuse And Landcover Classification For Independence, Union, Bradley And Cleveland Counties Of Arkansas, H. Don Scott, Kimberly Hofer Jan 1996

Landuse And Landcover Classification For Independence, Union, Bradley And Cleveland Counties Of Arkansas, H. Don Scott, Kimberly Hofer

Technical Reports

Landuse/landcover (LULC} is a function of natural factors such as soils, climate and water and of anthropogenic factors such as predominant use. In Arkansas, the primary use of the land varies depending on the physiographic region. For example, in the Mississippi Delta region of eastern Arkansas row crop agriculture predominates, whereas in the Gulf Coastal Plains forestry dominates. In both regions LULC is spatially and temporally . variable. Knowledge of LULC can be used in estimating the potential for agricultural production, locations of critical ecological areas, siting of homes, small businesses, industries, roads and landfills as well as source areas …


Electrodeposition Of Copper Indium Sulfide Films From Organic Solutions, Arif Raza, Robert Engelken, Brandon Kemp, Imran Khan, Wasim Aleem, Chris Barber Jan 1996

Electrodeposition Of Copper Indium Sulfide Films From Organic Solutions, Arif Raza, Robert Engelken, Brandon Kemp, Imran Khan, Wasim Aleem, Chris Barber

Journal of the Arkansas Academy of Science

We report on organic solutions ofCuCl 2 ,InClg, and elemental sulfur for electrodepositing CuIn x Sv films. CuInS 2 and CuInSe 2 are promising solar cellmaterials; our work on CuInSg prefaces planned work on plating CuInSe 2 from nonaqueous solvents. Two promising solvent systems are (1) mixed propylcne carbonate and water and (2) mixed ethylene glycol, propionic acid, and water (Engelken et al., 1988). Gray-brown films ofCuInx Sy (nominally GuInS2 ) have been plated from both baths. Major problems include (1) reduction ofCu+2 to Cu and Cu x S by the solvent at high temperatures (T>l()0°C), hence depleting Cu+2,(2) …


Microhollow Cathode Discharges, K. H. Schoenbach, R. Verhappen, R. Tessnow, F. E. Peterkin, W. W. Byszewski Jan 1996

Microhollow Cathode Discharges, K. H. Schoenbach, R. Verhappen, R. Tessnow, F. E. Peterkin, W. W. Byszewski

Bioelectrics Publications

The current–voltage characteristics of hollow cathode discharges and their predischarges in argon under dc and pulsed conditions were found to have a positive slope at pressures up to approximately 50 Torr, and currents up to 20 mA, at a hole diameter of 0.7 mm. In this range of pressure and current, parallel operation of hollow cathode discharges, without ballast, was demonstrated. Scaling to higher pressure is possible by reducing the hole diameter. Pulsed experiments with an array of cathode rings of 75 μm diameter allowed us to obtain parallel operation of more than 50 discharges at a pressure of 350 …


Iowa Academy Of Science 108th Annual Meeting [1996]: Advance Program, Iowa Academy Of Science Jan 1996

Iowa Academy Of Science 108th Annual Meeting [1996]: Advance Program, Iowa Academy Of Science

Iowa Academy of Science Documents

Contains information about the schedule and presentations for the 1996 annual meeting of the Iowa Academy of Science.


Determination Of Wavelength Dependent Quantum Yields For Iron (Iii) Photoreduction In Well Defined Chloride Media, J. Catherine Kneece Jan 1996

Determination Of Wavelength Dependent Quantum Yields For Iron (Iii) Photoreduction In Well Defined Chloride Media, J. Catherine Kneece

Honors Theses

The quantum yields for iron (lII) photoreduction in sodium chloride and sodium perchlorate media were measured as a function of wavelength. The experiments were conducted using natural levels of total iron, less than 300 nM. The results indicate that three species are photochemically active in these media, Fe(OH)+2, FeCl2+and FeCl2+. The quantum yields for (OH)+2 are 0.22 at 300 run and 0.076 at 340 nm. The quantum yields for FeCl+ are 0.048 at 300 run and 0.038 at 340 nm. The quantum yields for FeCl2+ are 0.088 at 300 nm and 0.051 at 340 nm. The data presented suggests that …


Alternatives To Nitroprusside As Hypotensive Agents, Timothy Casey Mccullough Jan 1996

Alternatives To Nitroprusside As Hypotensive Agents, Timothy Casey Mccullough

Honors Theses

The drug sodium pentacyanonitrosylferrate(2-)dihydrate, more commonly known as nitroprusside or nipride (Fig. 1), is a common vasodilating agent given clinically to patients with hypertension.12.22 Nitroprusside is effective in emergency rooms as it quickly reduces high blood pressure, but dosages are limited because of fear that cyanide could be released also. Nitroprusside is effective because the vasodilating agent nitric oxide, NO, is released. Nitric oxide is also recognized as an important biochemical messenger molecule.22 Our research involves a search for different species that could introduce nitric oxide into the body without cyanide. Transition metal complexes involving ruthenium, iron, and cobalt that …


A Computational And Experimental Investigation Of The Pinacol Coupling And Rearrangement Reactions, Ryan Sullivan Jan 1996

A Computational And Experimental Investigation Of The Pinacol Coupling And Rearrangement Reactions, Ryan Sullivan

Honors Theses

This project was developed from previous reports concerned with the pinacol coupling and rearrangement methodologies. It is hoped that the results and conclusions of this study may provide someone in the future a chance to gain a more complete view of this material. Analysis of the pinacol coupling reaction shows that the yields of the pinacol products are not statistical for the asymmetric cycloalkanone systems. Also, the yields of the 5-7 and 6-7 systems plotted versus ab initio gas phase calculations of HOMG-LUMO gaps showed r values at or near 1.00. This correlation is excellent and offers an example of …


How Rigid Is The Stable Interior Of The North American Plate?, Timothy H. Dixon, Ailin Mao, Seth Stein Jan 1996

How Rigid Is The Stable Interior Of The North American Plate?, Timothy H. Dixon, Ailin Mao, Seth Stein

School of Geosciences Faculty and Staff Publications

We analyze data from eight permanent GPS stations broadly distributed through the interior of the North American plate, and use the resulting velocities to estimate an Euler vector describing motion of “stable” North America as a single rigid plate. The site velocities fit the single plate model with a mean residual of 1.3 mm/yr. The residuals do not appear to reflect post-glacial rebound, and tests for differential motion between eastern and western North America at the New Madrid seismic zone show no resolvable motion within uncertainties. The residuals likely reflect observational error, and thus our estimate of the stability of …


Gypsum Karst Of France, Michel Chardon, Jean Nicod Jan 1996

Gypsum Karst Of France, Michel Chardon, Jean Nicod

International Journal of Speleology

Many small and scattered areas of gypsum karst are present in France. They occur in the plains and plateaux (Paris, Lorraine, Provence) as well as in the mountains, especially the Alps. Typical gypsum karst landforms are well developed and widespread, but underground cavities are scarce, despite much exploration and the apparent existence of subsurface waterflow. The Alps and Provence contain the largest karstic areas.


Speleogenesis In Gysum, Alexander Klimchouk Jan 1996

Speleogenesis In Gysum, Alexander Klimchouk

International Journal of Speleology

Satisfactory explanation of the origin and development of caves (speleogenesis) is a core problem of karst studies. Karst evolves as a circulation system, organised and interconnected through a conduit structure. Such a system may include superficial inputs and outputs, expressed as or related to karst landforms. However, there may be no such components if the system is represented entirely by conduits as in the case with deep-seated intrastratal karst. The main differences between speleogenesis in gypsum and in carbonate rocks lie in the chemistry and kinetics of their dissolution, in some of the lithological or structural peculiarities of the respective …


Hydrogeology Of Gypsum Formations, Alexander Klimchouk Jan 1996

Hydrogeology Of Gypsum Formations, Alexander Klimchouk

International Journal of Speleology

Detailed explanation of hydrogeological characteristics of gypsum aquifers is given in various situations: deep-seated karst-confined conditions, subjacent, entrenched and denuded karst types-semi-confined, phreatic and vadose conditions. The hydrogeological evolution of barren exposed gypsum karst and flow velocities in gypsum karst aquifers is also discussed.


Environmental Assessment Amendment To Grand Mesa National Forest Travel Management Plan Revision 100 Mile Proposal, United States Forest Service Jan 1996

Environmental Assessment Amendment To Grand Mesa National Forest Travel Management Plan Revision 100 Mile Proposal, United States Forest Service

All U.S. Government Documents (Utah Regional Depository)

The purpose of this Environmental Assessment (EA) is to describe the environmental effects of a proposal to evaluate reopening approximately 100 miles of the 299 miles of nonsystem routes which were closed to motorized use by the Decision Notice on the Grand Mesa National Forest Travel Management Plan Revision dated December 12, 1994.


Dutch Experience In Irrigation Water Management Modelling, B J. Van Den Broek Jan 1996

Dutch Experience In Irrigation Water Management Modelling, B J. Van Den Broek

All U.S. Government Documents (Utah Regional Depository)

Modeling the soil-water-crop atmosphere system to improve agricultural water management in arid zones (SWATRE); Groundwater approach to drainage design in irrigated agriculture (SGMP); Computer Program for flume and weir design (FLUME 3.0); A hydrodynamic model in the design of operational controllers for water systems (MODIS/MATLAB); Decision support simulation model for water management at a regional and national scale (SIWARE); Management of water delivery systems (RIBASIM/OMIS); A water allocation, scheduling, and monitoring program (WASAM); and Irrigation agencies, farmers and computational decision support tools.


Appendix 1 Public Comments And Forest Service Responses To The Environmental Assessment For 36 Livestock Grazing Allotments On The Shoshone National Forest, United States Forest Service Jan 1996

Appendix 1 Public Comments And Forest Service Responses To The Environmental Assessment For 36 Livestock Grazing Allotments On The Shoshone National Forest, United States Forest Service

All U.S. Government Documents (Utah Regional Depository)

Forest Service Regulations (36 CFR 215.6d) require publication of this appendix. Material in this appendix addresses comments received from the public during the comment period for the Environmental Assessment for 36 Livestock Grazing Allotments on the Shoshone National Forest. This appendix will be attached to any Decision Notices that may result.


Flood Insurance Study, Town Of Wendover, Utah, Tooele County, Federal Emergency Management Agency Jan 1996

Flood Insurance Study, Town Of Wendover, Utah, Tooele County, Federal Emergency Management Agency

All U.S. Government Documents (Utah Regional Depository)

This Flood Insurance Study revises and updates a previous Flood Insurance Study/Flood Insurance Rate Map for the Town of Wendover, Tooele County, Utah. This information will be used by the Town of Wendover to update existing floodplain regulations as part of the Regular Phase of the National Flood Insurance Program (NFIP). The information will also be used by local and regional planners to further promote sound land use and floodplain development.


Bats, Veda Depaepe, Terry A. Messmer, Michael R. Conover Jan 1996

Bats, Veda Depaepe, Terry A. Messmer, Michael R. Conover

All Archived Publications

No abstract provided.


Overview Of Techniques For Reducing Bird Predation At Aquaculture Facilities, Kimberly S. Curtis, William C. Pitt, Michael R. Conover Jan 1996

Overview Of Techniques For Reducing Bird Predation At Aquaculture Facilities, Kimberly S. Curtis, William C. Pitt, Michael R. Conover

All Archived Publications

No abstract provided.


Desert Plants Of Utah, Berniece A. Andersen Jan 1996

Desert Plants Of Utah, Berniece A. Andersen

All Archived Publications

No abstract provided.