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University of Kentucky

Series

2000

Articles 1 - 30 of 42

Full-Text Articles in Physical Sciences and Mathematics

Continuum Pumping Of [Fe Ii] In The Orion Nebula, E. M. Verner, D. A. Verner, J. A. Baldwin, Gary J. Ferland, P. G. Martin Nov 2000

Continuum Pumping Of [Fe Ii] In The Orion Nebula, E. M. Verner, D. A. Verner, J. A. Baldwin, Gary J. Ferland, P. G. Martin

Physics and Astronomy Faculty Publications

This paper presents detailed comparisons between numerical simulations of Fe II emission spectra and recent high-resolution and signal-to-noise spectra of the Orion Nebula. We have identified 40 [Fe II] lines in the spectrum, allowing extensive comparisons between theory and observations. The identifications are based on predictions of a realistic model of the Fe II atom, which includes the lowest 371 levels (all levels up to 11.6 eV). We investigate the dependence of the spectrum on electron density and on pumping by the stellar continuum. Orion is important because it provides a relatively simple environment in which to test complex simulations. …


Simulation Of Daily And Monthly Stream Discharge From Small Watersheds Using The Swat Model, Crystal A. Spruill, Stephen R. Workman, Joseph L. Taraba Nov 2000

Simulation Of Daily And Monthly Stream Discharge From Small Watersheds Using The Swat Model, Crystal A. Spruill, Stephen R. Workman, Joseph L. Taraba

Biosystems and Agricultural Engineering Faculty Publications

The Soil and Water Assessment Tool (SWAT) was evaluated and parameter sensitivities were determined while modeling daily streamflows in a small central Kentucky watershed over a two-year period. Streamflow data from 1996 were used to calibrate the model and streamflow data from 1995 were used for evaluation. The model adequately predicted the trends in daily streamflow during this period although Nash-Sutcliffe R2 values were –0.04 and 0.19 for 1995 and 1996, respectively. The model poorly predicted the timing of some peak flow values and recession rates during the last half of 1995. Excluding daily peak flow values from August …


Metallic Nanoscale Fibers From Stable Iodine-Doped Carbon Nanotubes, Peter C. Eklund, Leonid Grigorian, Keith A. Williams, Gamini U. Sumanasekera, Shaoli Fang Oct 2000

Metallic Nanoscale Fibers From Stable Iodine-Doped Carbon Nanotubes, Peter C. Eklund, Leonid Grigorian, Keith A. Williams, Gamini U. Sumanasekera, Shaoli Fang

Physics and Astronomy Faculty Patents

A method of doping involves soaking single-walled carbon nanotubes in molten iodine. Excess physisorbed iodine may then be removed by annealing.


Observational Constraints On The Internal Velocity Field Of Quasar Emission-Line Clouds, Mark Bottorff, Gary J. Ferland, Jack Baldwin, Kirk Korista Oct 2000

Observational Constraints On The Internal Velocity Field Of Quasar Emission-Line Clouds, Mark Bottorff, Gary J. Ferland, Jack Baldwin, Kirk Korista

Physics and Astronomy Faculty Publications

This paper addresses the question, what does the spectrum of a typical quasar reveal about the velocity structure within its broad emission line region clouds? Turbulent (i.e., nonthermal) broadening of spectral lines can be due to macroturbulence or microturbulence. Microturbulence affects line formation and the emitted spectrum and may be required to account for the observed smoothness of the line profiles. The velocity field is crucial since it addresses the fundamental nature of the individual clouds and the global structure of the active galactic nuclei (AGNs) environment. For example, stellar winds or magnetically confined blobs might be highly microturbulent, requiring …


Pride Water Quality Assessment Report: I. Problems And Programs, Kentucky Water Resources Research Institute. University Of Kentucky Sep 2000

Pride Water Quality Assessment Report: I. Problems And Programs, Kentucky Water Resources Research Institute. University Of Kentucky

KWRRI Research Reports

This report provides an overview of the water quality problems and associated state and federal programs in the 40 counties that make up the PRIDE region. The 2000 Kentucky 305(b) stream assessment has identified over 1000 miles of impaired stream within the region. The major cause of pollution in the region is related to problems with pathogens. Much of these problems are related to straight pipes and failing septic and wastewater systems. It has been estimated that there are over 35,000 straight pipes and failing septic systems in the PRIDE region. A second major environmental impact in the region is …


Pride Water Quality Assessment Report: Iii. Existing And Proposed Monitoring Network, Kentucky Water Resources Research Institute, University Of Kentucky Sep 2000

Pride Water Quality Assessment Report: Iii. Existing And Proposed Monitoring Network, Kentucky Water Resources Research Institute, University Of Kentucky

KWRRI Research Reports

This document provides a recommendation for proposed sampling sites in support of the general water quality assessment of the 40 county PRIDE region. A general assessment of the associated environmental problems and programs in the region can be found in the companion report: PRIDE Water Quality Assessment Report I: Problems and Programs while the report PRIDE Water Quality Assessment Report II: Chemical, Biological and Habitat Assessments provides a 10 year baseline assessment of environmental conditions in the region as measured by indicators of pH, fecal coliforms, habitat assessment, and macro-invertebrate assessment.


Pride Water Quality Assessment Report: Ii. Chemical, Biological And Habitat Assessments, Kentucky Water Resources Research Institute, University Of Kentucky Sep 2000

Pride Water Quality Assessment Report: Ii. Chemical, Biological And Habitat Assessments, Kentucky Water Resources Research Institute, University Of Kentucky

KWRRI Research Reports

The efficient utilization of federal funds in improving the water quality and aquatic habitat of the region requires a mechanism for assessing and evaluating the impacts of the proposed and ongoing projects as well as some mechanism for prioritizing the allocation of additional funds. In order to evaluate the effectiveness of these projects it is important to provide a formal monitoring and assessment program based on sound scientific principles. This report provides an initial 10 year baseline assessment of the existing water quality conditions in the 40 county PRIDE·region for the purpose of evaluating the impacts of the PRIDE programs …


Clathrate Structure For Electronic And Electro-Optic Applications, Leonid Grigorian, Peter C. Eklund, Shaoli Fang Aug 2000

Clathrate Structure For Electronic And Electro-Optic Applications, Leonid Grigorian, Peter C. Eklund, Shaoli Fang

Physics and Astronomy Faculty Patents

A method including the steps of (a) depositing a metal layer on a selected portion of a silicon substrate under a first set of predetermined conditions to form an metal silicide layer and an intermediate n-type silicon layer; and (b) exposing the metal silicide layer and the n-type silicon layer to a second set of predetermined conditions to form a silicon clathrate film on the selected portion of the silicon substrate, where the intermediate n-type silicon layer acts to bond the silicon clathrate to the silicon substrate to form a silicon clathrate structure.


The Narrow-Line Region In The Seyfert 2 Galaxy Ngc 3393, Andrew J. Cooke, J. A. Baldwin, Gary J. Ferland, Hagai Netzer, Andrew S. Wilson Aug 2000

The Narrow-Line Region In The Seyfert 2 Galaxy Ngc 3393, Andrew J. Cooke, J. A. Baldwin, Gary J. Ferland, Hagai Netzer, Andrew S. Wilson

Physics and Astronomy Faculty Publications

The narrow-line region (NLR) of the Seyfert 2 galaxy NGC 3393 is dominated by a symmetric structure which appears as S-shaped arms in Hubble Space Telescope (HST) images. These arms, which occupy the central few arcseconds of the nucleus, border a linear, triple-lobed radio source. We use HST imaging and spectra, ground-based optical images, long-slit spectra, Fabry-Perot imaging spectroscopy, and VLA radio data to perform a detailed investigation of the kinematics and ionization of the line-emitting gas in NGC 3393 and of its relationship with the relativistic gas responsible for the radio emission. The excitation map [O III] …


Thermolectric Materials Based On Intercalated Layered Metallic Systems, Peter C. Eklund, Leonid Grigorian, Keith A. Williams, Gamini U. Sumanasekera Jul 2000

Thermolectric Materials Based On Intercalated Layered Metallic Systems, Peter C. Eklund, Leonid Grigorian, Keith A. Williams, Gamini U. Sumanasekera

Physics and Astronomy Faculty Patents

A novel thermoelectric material in the form of a unit cell including a first reagent intercalated as a semiconducting layer into a metallic layered host and a method for producing the thermoelectric material are disclosed. The unit cell is characterized by a Seebeck coefficient S of 80-140 μV/K° and an electrical conductivity σ of 103 -104 (Ωcm)-1, as well as a figure of merit Z of about 2×10-3 K-1 at 100° K.


The Primordial Helium Abundance: Toward Understanding And Removing The Cosmic Scatter In The Dy/Dz Relation, D. R. Ballantyne, Gary J. Ferland, P. G. Martin Jun 2000

The Primordial Helium Abundance: Toward Understanding And Removing The Cosmic Scatter In The Dy/Dz Relation, D. R. Ballantyne, Gary J. Ferland, P. G. Martin

Physics and Astronomy Faculty Publications

We present results from photoionization models of low-metallicity H II regions. These nebulae form the basis for measuring the primordial helium abundance. Our models show that the helium ionization correction factor (ICF) can be nonnegligible for nebulae excited by stars with effective temperatures larger than 40,000 K. Furthermore, we find that when the effective temperature rises to above 45,000 K, the ICF can be significantly negative. This result is independent of the choice of stellar atmosphere. However, if an H II region has an [O III] λ5007/[O I] λ6300 ratio greater than 300, then our models show that, regardless of …


Infrared Classification Of Galactic Objects, Željko Ivezić, Moshe Elitzur May 2000

Infrared Classification Of Galactic Objects, Željko Ivezić, Moshe Elitzur

Physics and Astronomy Faculty Publications

Unbiased analysis shows that IRAS data reliably differentiate between the early and late stages of stellar evolution because objects at these stages clearly segregate in infrared color-color diagrams. Structure in these diagrams is primarily controlled by the density distribution of circumstellar dust. The density profile around older objects is the steepest, declining as r-2, while young objects have profiles that vary as r-3/2 and flatter. The different density profiles reflect the different dynamics that govern the different environments. Our analysis also shows that high-mass star formation is strongly concentrated within ~5 kpc around the Galactic center, in …


Properties Of Dust Grains In Planetary Nebulae. I. The Ionized Region Of Ngc 6445, Peter A. M. Van Hoof, Griet C. Van De Steene, Douwe A. Beintema, P. G. Martin, Stuart R. Pottasch, Gary J. Ferland Mar 2000

Properties Of Dust Grains In Planetary Nebulae. I. The Ionized Region Of Ngc 6445, Peter A. M. Van Hoof, Griet C. Van De Steene, Douwe A. Beintema, P. G. Martin, Stuart R. Pottasch, Gary J. Ferland

Physics and Astronomy Faculty Publications

One of the factors influencing the spectral evolution of a planetary nebula is the fate of the dust grains that are emitting the infrared continuum. Several processes have been proposed that either destroy the grains or remove them from the ionized region. To test whether these processes are effective, we study new infrared spectra of the evolved nebula NGC 6445. These data show that the thermal emission from the grains is very cool and has a low flux compared to Hβ. A model of the ionized region is constructed, using the photoionization code CLOUDY 90.05. Based on this model, we …


1999 Kentucky River Watershed Watch Data Collection Effort, L. Ormsbee, E. Caudill, G. Epp Feb 2000

1999 Kentucky River Watershed Watch Data Collection Effort, L. Ormsbee, E. Caudill, G. Epp

Kentucky River Watershed Watch

No abstract provided.


Effect Of Magnesium And Sulfur Fertilization Of Alfalfa, Kenneth L. Wells, James E. Dollarhide Jan 2000

Effect Of Magnesium And Sulfur Fertilization Of Alfalfa, Kenneth L. Wells, James E. Dollarhide

Soil Science News and Views

In response to concerns that high yields of alfalfa need to be fertilized with sulfur (S) because of soil depletion of S and less S entering the soil from atmospheric fallout, studies were conducted during 1998-1999, to test for S response by alfalfa. Additionally, alfalfa was tested for magnesium (Mg) response because previous hay analysis from the study site had shown very low levels of Mg.


Irrigated Field Crop Acres In Kentucky, Lloyd W. Murdock Jan 2000

Irrigated Field Crop Acres In Kentucky, Lloyd W. Murdock

Soil Science News and Views

Irrigation in Kentucky has always been limited. This is due to a limited water supply in many parts of Kentucky and the high amount of rainfall in the state which reduces the chances for a consistent profitable response to field crops.


Soil Testing For Agronomic And Environmental Uses, William O. Thom, Frank J. Sikora Jan 2000

Soil Testing For Agronomic And Environmental Uses, William O. Thom, Frank J. Sikora

Soil Science News and Views

Soil testing is a program that includes taking samples from a field or site, performing a laboratory analysis, and making recommendations for lime and crop nutrients. Good results from this program depend on several supporting factors: (I) obtaining samples representative of the soil in a field area or site; (2) using good techniques in the laboratory that give accurate indications of the nutrient status of the sampled area; and (3) having an extensive data base for making lime and nutrient recommendations from the analytical results.


Drawdown Of Soil Test Phosphorus And Potassium Levels By Alfalfa, Kenneth L. Wells, James E. Dollarhide Jan 2000

Drawdown Of Soil Test Phosphorus And Potassium Levels By Alfalfa, Kenneth L. Wells, James E. Dollarhide

Soil Science News and Views

Alfalfa hay production removes large amounts of phosphorus (P) and potassium (K) from soils. Because of this, there is always interest in the reduction of soil test phosphorus (STP) and soil test potassium (STK) levels by high-yielding alfalfa. Periodic soil sampling for 2 years during an on-farm· fertilizer study on a high yielding alfalfa field provided an insight into this.


Evaporation Reduction Potential In An Undisturbed Soil Irrigated With Surface Drip And Sand Tube Irrigation, Masoud Meshkat, Richard C. Warner, Stephen R. Workman Jan 2000

Evaporation Reduction Potential In An Undisturbed Soil Irrigated With Surface Drip And Sand Tube Irrigation, Masoud Meshkat, Richard C. Warner, Stephen R. Workman

Biosystems and Agricultural Engineering Faculty Publications

The efficiency of drip irrigation is highly dependent on evaporation losses occurring from the constantly saturated soil beneath emitters. Advent of subsurface drip irrigation is in part an approach to curb this inefficiency. An irrigation method, Sand Tube Irrigation (STI), is proposed to increase the efficiency of “Normal” surface applied drip Irrigation (NI method) on permanent tree crops without the need for burying the irrigation tubing. The sand tube consists of removing a soil core beneath the emitter and filling the void with coarse sand. A weighing lysimeter was constructed in the laboratory and instrumented to directly measure temporal evaporation …


Overview Of Environmental Regulations That Affect Coal Combustion, Cortland F. Eble Jan 2000

Overview Of Environmental Regulations That Affect Coal Combustion, Cortland F. Eble

Information Circular--KGS

Environmental regulations have had, and continue to have, an effect on the combustion of coal. These regulations largely affect the electric utility industry, the largest consumer of domestic coal, but they ultimately affect everyone, because we all use electricity, and the cost of compliance is usually passed on to the consumer, resulting in higher electric bills.


Coal Resources Of The Lower Elkhorn Coal Bed In Eastern Kentucky, Ernest E. Thacker, Gerald A. Weisenfluh, William M. Andrews Jr., John K. Hiett Jan 2000

Coal Resources Of The Lower Elkhorn Coal Bed In Eastern Kentucky, Ernest E. Thacker, Gerald A. Weisenfluh, William M. Andrews Jr., John K. Hiett

Map and Chart--KGS

This chart is one of a series that shows the regional characteristics of the Lower Elkhorn coal. The maps were prepared as part of the U.S. Geological Survey's Natural Coal Assessment Program, which compiles regional maps and databases that provide a comprehensive assessment of the most important coal beds in the nation. The Lower Elkhorn coal is one of the leading producers in the state of Kentucky and has, in some areas, a reputation as an excellent metallurgical-grade coal. It is known locally as the Pond Creek, Imboden, Path Fork, Blue Gem, Straight Creek, Bruin or Vires coal bed. This …


Coal Resources Of The Fire Clay Coal Zone In Eastern Kentucky, Ernest E. Thacker, Gerald A. Weisenfluh, Jeffery A. Esterle, Stephen F. Greb, John K. Hiett Jan 2000

Coal Resources Of The Fire Clay Coal Zone In Eastern Kentucky, Ernest E. Thacker, Gerald A. Weisenfluh, Jeffery A. Esterle, Stephen F. Greb, John K. Hiett

Map and Chart--KGS

This chart is one of a series that shows the regional characteristics of the Fire Clay coal zone. The maps and charts were prepared as part of the U.S. Geological Survey's National Coal Assessment Program, which compiles regional maps and databases that provide a comprehensive assessment of the most important coal beds in the nation. Within this coal zone, the Fire Clay coal is the most economically important bed and is one of the leading producers in the state of Kentucky. The Fire Clay coal contains a flint-clay parting that is believed to be of volcanic origin. The widespread occurrence …


Mining Geology Of Coals In Western Kentucky, Stephen F. Greb, David A. Williams Jan 2000

Mining Geology Of Coals In Western Kentucky, Stephen F. Greb, David A. Williams

Map and Chart--KGS

Each of the most heavily mined coal seams in the Western Kentucky Coal Field, as indicated by analyses, mine visits, and discussions with mine inspectors and engineers, has its own roof and floor characteristics. Also, because roof rocks above several of the seams are laterally continuous (especially in the Carbondale Formation), roof characteristics related to rock type are often widespread and continuous between mines. This chart discusses the mining geology of three western Kentucky coal beds, highlighted on the stratigraphic column shown in Figure 1.

Additional mining obstacles that can affect all coal beds and roof strata are (1) tectonic …


Total Coal Thickness Of The Upper Elkhorn No. 3a Coal (Lower Bed) In Eastern Kentucky, Jeffery A. Esterle, Ernest E. Thacker, Gerald A. Weisenfluh Jan 2000

Total Coal Thickness Of The Upper Elkhorn No. 3a Coal (Lower Bed) In Eastern Kentucky, Jeffery A. Esterle, Ernest E. Thacker, Gerald A. Weisenfluh

Map and Chart--KGS

This map is one of a series that shows the regional characteristics of the Upper Elkhorn No. 3 coal zone. The maps were prepared as part of the U.S. Geological Survey's National Coal Assessment Program, which compiles regional maps and databases that provide a comprehensive assessment of the most important coal beds in the nation. The Upper Elkhorn No. 3 coal zone has been one of the leading producers in the state of Kentucky and, in some areas, contains very high-quality coal. The zone is composed of a number of distinct coal beds that merge in some areas to form …


Coal Resources Of The Upper Elkhorn No. 3b Coal (Upper Bed) In Eastern Kentucky, Jeffery A. Esterle, Ernest E. Thacker, Gerald A. Weisenfluh, John K. Hiett Jan 2000

Coal Resources Of The Upper Elkhorn No. 3b Coal (Upper Bed) In Eastern Kentucky, Jeffery A. Esterle, Ernest E. Thacker, Gerald A. Weisenfluh, John K. Hiett

Map and Chart--KGS

This chart is one of a series that shows the regional characteristics of the Upper Elkhorn No. 3 coal zone. The maps and charts were prepared as part of the U.S. Geological Survey's National Coal Assessment Program, which compiles regional maps and databases that provide a comprehensive assessment of the most important coal beds in the nation. The Upper Elkhorn No. 3 coal zone has been one of the leading producers in the state of Kentucky and, in some areas, is of very high quality. Bed stratigraphy within the Upper Elkhorn No. 3 zone and thickness of the No. 3A …


Mapped Karst Ground-Water Basins In The Bowling Green 30 X 60 Minute Quadrangle, Joseph A. Ray, James C. Currens Jan 2000

Mapped Karst Ground-Water Basins In The Bowling Green 30 X 60 Minute Quadrangle, Joseph A. Ray, James C. Currens

Map and Chart--KGS

This map shows karst ground-water basins in the Bowling Green quadrangle, determined primarily by ground-water tracer studies. It can be used to quickly identify the ground-water basins and springs to which a site may drain. Major springs and the relative size of their catchment areas can be evaluated for potential as water supplies. The map also serves as a geographic index to literature on karst ground water in the area.


On Preconditioning Schur Complement And Schur Complement Preconditioning, Jun Zhang Jan 2000

On Preconditioning Schur Complement And Schur Complement Preconditioning, Jun Zhang

Computer Science Faculty Publications

We study two implementation strategies to utilize Schur complement technique in multilevel recursive incomplete LU preconditioning techniques (RILUM) for solving general sparse matrices. The first strategy constructs a RILUM to precondition the original matrix. The second strategy solves the first Schur complement matrix using the lower level parts of the RILUM as the preconditioner. We discuss computational and memory costs of both strategies and the potential effect on grid independent convergence rate of RILUM with different implementation strategies.


Effects Of Longwall Mining On Hydrology, Leslie County, Kentucky Part 2: During-Mining Conditions, Shelley Minns Hutcheson, James A. Kipp, James S. Dinger, Lyle V.A. Sendlein, Daniel I. Carey, Gregory L. Secrist Jan 2000

Effects Of Longwall Mining On Hydrology, Leslie County, Kentucky Part 2: During-Mining Conditions, Shelley Minns Hutcheson, James A. Kipp, James S. Dinger, Lyle V.A. Sendlein, Daniel I. Carey, Gregory L. Secrist

Report of Investigations--KGS

The effects of longwall coal mining on hydrology in the Eastern Kentucky Coal Field are being investigated. The study area is in the Edd Fork watershed in southern Leslie County, over Shamrock Coal Company's Beech Fork Mine. Longwall panels approximately 700 ft wide are separated by three-entry gateways that are approximately 200 ft wide. The mine is operated in the Fire Clay (Hazard No. 4) coal; overburden thickness ranges from 300 to 800 ft. Mining began in panel 1 in September 1991 and concluded with panel 8 in September 1994. Long-term monitoring consisting of a network of piezometers and time-domain …


Effects Of Longwall Mining On Hydrogeology, Leslie County, Kentucky Part 3: Post-Mining Conditions, Shelley Minns Hutcheson, James A. Kipp, James S. Dinger, Daniel I. Carey, Lyle V.A. Sendlein, Gregory L. Secrist Jan 2000

Effects Of Longwall Mining On Hydrogeology, Leslie County, Kentucky Part 3: Post-Mining Conditions, Shelley Minns Hutcheson, James A. Kipp, James S. Dinger, Daniel I. Carey, Lyle V.A. Sendlein, Gregory L. Secrist

Report of Investigations--KGS

The effects of longwall coal mining on hydrology in the Eastern Kentucky Coal Field have been investigated since 1991. The study area is in the Edd Fork watershed in southern Leslie County, over Shamrock Coal Company's Beech Fork Mine. Longwall panels approximately 700 ft wide are separated by three-entry gateways that are approximately 200 ft wide. The mine is operated in the Fire Clay (Hazard No. 4) coal; overburden thickness ranges from 300 to 800 ft. Mining began in panel 1 in September 1991 and concluded with panel 8 in September 1994. Long-term monitoring consisting of a network of piezometers …


The Effect Of Turfgrass Maintenance On Surface-Water Quality In A Suburban Watershed, Inner Blue Grass, Kentucky, R. Michael Williams, James S. Dinger, Andrew J. Powell, Dwayne R. Edwards Jan 2000

The Effect Of Turfgrass Maintenance On Surface-Water Quality In A Suburban Watershed, Inner Blue Grass, Kentucky, R. Michael Williams, James S. Dinger, Andrew J. Powell, Dwayne R. Edwards

Report of Investigations--KGS

Nutrients and pesticides applied during routine maintenance or establishment of turfgrass could result in nonpoint-source pollution. Nutrient and pesticide concentrations in water exiting a turfgrass management area in the Sinking Creek watershed, a suburban watershed in the Inner Blue Grass Region of central Kentucky, were monitored. This watershed was selected because it contains multiple land uses: agricultural, residential, and recreational (golf course).

A survey was conducted to determine the extent to which lawn-care products are used in the residential sector of the watershed. For the golf-course portion, the golf-course superintendent recorded chemical application daily.

Runoff from the golf course was …