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1996

University of Kentucky

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Articles 1 - 30 of 59

Full-Text Articles in Physical Sciences and Mathematics

Physical Conditions In Low-Ionization Regions Of The Orion Nebula, J. A. Baldwin, A. Crotts, R. J. Dufour, Gary J. Ferland, S. Heathcote, J. J. Hester, K. T. Korista, P. G. Martin, C. R. O'Dell, R. H. Rubin, A. G. G. M. Tielens, D. A. Verner, D. K. Walter, Z. Wen Sep 1996

Physical Conditions In Low-Ionization Regions Of The Orion Nebula, J. A. Baldwin, A. Crotts, R. J. Dufour, Gary J. Ferland, S. Heathcote, J. J. Hester, K. T. Korista, P. G. Martin, C. R. O'Dell, R. H. Rubin, A. G. G. M. Tielens, D. A. Verner, D. K. Walter, Z. Wen

Physics and Astronomy Faculty Publications

We reexamine the spectroscopic underpinnings of recent suggestions that [O I] and [Fe II] lines from the Orion H II region are produced in gas where the iron-carrying grains have been destroyed and the electron density is surprisingly high. Our new observations show that previous detections of [O I] 5577 were dominated by telluric emission. Our limits are consistent with a moderate density (≈ 104 cm-3) photoionized gas. We show that a previously proposed model of the Orion H II region reproduces the observed [O I] and [Fe II] spectrum. These lines are fully consistent with formation …


Rate Coefficients For Charge Transfer Between Hydrogen And The First 30 Elements, J. B. Kingdon, Gary J. Ferland Sep 1996

Rate Coefficients For Charge Transfer Between Hydrogen And The First 30 Elements, J. B. Kingdon, Gary J. Ferland

Physics and Astronomy Faculty Publications

We present analytic fits to charge exchange rate coefficients over the full range of temperatures which occurs in photoionized or shock-heated plasmas. We consider reactions between neutral hydrogen and all elements with parent ion charge q = 1-4 up to Z = 30. Many rates were obtained from various sources in the literature. For reactions for which no data were available, we calculated rates using the Landau-Zener formalism. For these new reactions, we tabulate both total and state-specific rate coefficients. Ml are fitted with a consistent, accurate formula. These fits may be incorporated easily into spectral synthesis codes, and we …


Atomic Data For Astrophysics. Ii. New Analytic Fits For Photoionization Cross Sections Of Atoms And Ions, D. A. Verner, Gary J. Ferland, K. T. Korista, D. G. Yakovlev Jul 1996

Atomic Data For Astrophysics. Ii. New Analytic Fits For Photoionization Cross Sections Of Atoms And Ions, D. A. Verner, Gary J. Ferland, K. T. Korista, D. G. Yakovlev

Physics and Astronomy Faculty Publications

We present a complete set of analytic fits to the nonrelativistic photoionization cross sections for the ground states of atoms and ions of elements from H through Si, and S, Ar, Ca, and Fe. Near the ionization thresholds, the fits are based on the Opacity Project theoretical cross sections interpolated and smoothed over resonances. At higher energies, the fits reproduce calculated Hartree-Dirac-Slater photoionization cross sections.


Formulation Enhanced Transport Of A Soil Applied Herbicide, V. P. Evangelou, Louis M. Mcdonald, Sandra Prima Jun 1996

Formulation Enhanced Transport Of A Soil Applied Herbicide, V. P. Evangelou, Louis M. Mcdonald, Sandra Prima

KWRRI Research Reports

Because pesticides are applied as formulated particles and the affinity of the active ingredient for the formulation is higher than for the bulk water, we hypothesized that a formulation complex could affect active ingredient transport. Our objectives were to investigate the nature and extent of surfactant-atrazine-clay/oxide surface interactions. When atrazine and an anionic surfactant were dried onto plain or Fe-coated sand and leached, atrazine concentrations in the initial leachate were lower in the Fe-coated sand treatment. This was likely due to an electrostatic attraction between the sand and surfactant. When a nonionic surfactant was used, atrazine concentration in the initial …


Modeling Transport Of Colloid-Bound Herbicides And Heavy Metals To Groundwater, Anastasios D. Karathanasis, R. E. Phillips, A. K. Seta Jun 1996

Modeling Transport Of Colloid-Bound Herbicides And Heavy Metals To Groundwater, Anastasios D. Karathanasis, R. E. Phillips, A. K. Seta

KWRRI Research Reports

Recent studies have suggested that contaminant transport to groundwater may be enhanced by association with colloidal particles. This study evaluated the role of water dispersible colloids with diverse mineralogical composition in co-transporting selected herbicides and heavy metals through intact soil columns. Colloid recovery in the eluents ranged from 45-90% for the herbicides and 10-60% for the heavy metals. The presence of colloids enhanced the transport of atrazine by 2-18%, and metolachlor by 8-30%. The corresponding increase for Cu and Zn was 2-150 and 5-30 times, respectively. For Pb, there was essentially no elution in the absence of colloids, suggesting nearly …


Metal-Resistance Genetically Engineered Bacteria, Sylvia Daunert, Donna Scott, Sridhar Ramanathan Jun 1996

Metal-Resistance Genetically Engineered Bacteria, Sylvia Daunert, Donna Scott, Sridhar Ramanathan

KWRRI Research Reports

Bacterial-based electrochemical and optical sensing systems that respond in a highly selective and sensitive manner to antimonite and arsenite have been developed. This was accomplished by using genetically engineered bacteria bearing one of two plasmids constructed for our studies. The first plasmid, pBGD23, contains the operator/promoter region (O/P) and the gene of the ArsR protein from the ars operon upstream from the β-galactosidase gene. In the absence of antimonite/arsenite, ArsR binds to the 0/P site and prevents the transcription of the genes for ArsR and β-galactosidase, thus blocking expression of these proteins. When antimonite or arsenite is present in the …


Mapped Karst Ground-Water Basins In The Lexington 30 X 60 Minute Quadrangle, James C. Currens, Joseph A. Ray Jun 1996

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

Map and Chart--KGS

No abstract provided.


High Metal Enrichments In Luminous Quasars, Gary J. Ferland, Jack A. Baldwin, Kirk T. Korista, Fred Hamann, R. F. Carswell, Mark Phillips, Belinda J. Wilkes, Robert E. Williams Apr 1996

High Metal Enrichments In Luminous Quasars, Gary J. Ferland, Jack A. Baldwin, Kirk T. Korista, Fred Hamann, R. F. Carswell, Mark Phillips, Belinda J. Wilkes, Robert E. Williams

Physics and Astronomy Faculty Publications

We discuss observations of the broad emission line in luminous intermediate redshift quasars, with emphasis on Q0207 -398. This object has relatively sharp lines, allowing us to deconvolve the profiles into distinct components. In this paper we examine the high ionization region, which we show must be matter-bounded, partially transparent to ionizing radiation. We measure a large N V λ1240/He II λ1640 ratio in Q0207-398, but detailed calculations predict this ratio to be ~1 for standard cloud properties. We show that no choice of incident continuum, ionizing photon flux, density, or even the appeal to nonradiative energy sources, can reproduce …


Very High Density Clumps And Outflowing Winds In Qso Broad-Line Regions, J. A. Baldwin, Gary J. Ferland, K. T. Korista, R. F. Carswell, F. Hamann, M. M. Phillips, D. A. Verner, Belinda J. Wilkes, R. E. Williams Apr 1996

Very High Density Clumps And Outflowing Winds In Qso Broad-Line Regions, J. A. Baldwin, Gary J. Ferland, K. T. Korista, R. F. Carswell, F. Hamann, M. M. Phillips, D. A. Verner, Belinda J. Wilkes, R. E. Williams

Physics and Astronomy Faculty Publications

Intercomparison of the spectra of seven high-luminosity quasi-stellar objects (QSOs) shows that there is a gradation of properties in their broad emission-line regions (BELRs) that can be understood as differing mixtures of different gas components. Six of these seven objects have unusually narrow BELR profiles, which greatly facilitates the disentangling of blends and measuring of weak lines. In the QSO 0207 - 398, the BELR is made up of at least three kinematically distinct components; its spectrum is in fact a composite of the spectra of the more homogeneous BELRs in the QSOs at either end of our sequence of …


The Chemical Enrichment Of Gas In Broad Absorption Line Qsos: Rapid Star Formation In The Early History Of Galaxies, Kirk Korista, Fred Hamann, Jason W. Ferguson, Gary J. Ferland Apr 1996

The Chemical Enrichment Of Gas In Broad Absorption Line Qsos: Rapid Star Formation In The Early History Of Galaxies, Kirk Korista, Fred Hamann, Jason W. Ferguson, Gary J. Ferland

Physics and Astronomy Faculty Publications

Utilizing spectra from ground-based and Hubble Space Telescope observations, Korista et al. identified at least 12 broad absorption lines in the broad absorption line (BAL) QSO 0226-1024 (zem = 2.256), many for the first time. In the present paper we use seven of their measured column densities to investigate the BAL gas ionization equilibrium and metallicity. We assume that the metal abundances follow the rapid star formation (RSF) models of Hamann & Ferland or are simply scaled from solar ratios to (1) limit the free parameters in constraining the overall metallicity and (2) test the applicability of such a …


Atomic Data For Astrophysics. I. Radiative Recombination Rates For H-Like, He-Like, Li-Like, And Na-Like Ions Over A Broad Range Of Temperature, D. A. Verner, Gary J. Ferland Apr 1996

Atomic Data For Astrophysics. I. Radiative Recombination Rates For H-Like, He-Like, Li-Like, And Na-Like Ions Over A Broad Range Of Temperature, D. A. Verner, Gary J. Ferland

Physics and Astronomy Faculty Publications

We present new calculations and analytic fits to the rates of radiative recombination towards H-like, He-like, Li-like and Na-like ions of all elements from H through Zn (Z=30). The fits are valid over a wide range of temperature, from 3 K to 109 K.


Flash-Flood Monitoring And Modeling In Kentucky, Mark French, Nageshwar Bhaskar, George K. A. Kyiamah Mar 1996

Flash-Flood Monitoring And Modeling In Kentucky, Mark French, Nageshwar Bhaskar, George K. A. Kyiamah

KWRRI Research Reports

This research project focused on the evaluation of hydrologic issue of flash-flooding in the state of Kentucky. The primary objectives of this project were the following:
(1) to initiate the establishment of a hydrologic database archive necessary for characterizing rainfall and runoff associated with flash-flooding;
(2) identification of appropriate modeling approaches for evaluating site-specific flash-flood runoff behavior.

Specific tasks accomplished to meet the objectives include the following:
(1) development of a rainfall and streamflow data archive using existing measurement gages and identification of the rain gage data from two sources for preliminary quality control;
(2) identification of the spatial and …


Marketing Options For Quality Kentucky Alfalfa Hay, Tom Keene Feb 1996

Marketing Options For Quality Kentucky Alfalfa Hay, Tom Keene

Kentucky Alfalfa and Stored Forage Conference

As today's farmer becomes more and more business like, running his farming operation as a commercial business, the production of alfalfa hay should be treated no differently. When the farmer makes the decision to plant alfalfa, he should have already done a great deal of research and given a great deal of thought into the markets he is going to try to target for his product. Any successful commercial business looks into market potential even before production begins, whether they produce toys, cars, appliances, computers, etc. Alfalfa hay production should be no different in regards to seeking out various markets …


What Leading Alfalfa Growers Do To Produce Quality Hay, Jimmy C. Henning, Garry D. Lacefield, Buddy Sims Feb 1996

What Leading Alfalfa Growers Do To Produce Quality Hay, Jimmy C. Henning, Garry D. Lacefield, Buddy Sims

Kentucky Alfalfa and Stored Forage Conference

Alfalfa is the highest quality forage legume crop grown in Kentucky and is the number one cash hay crop. Hay raised by Kentucky farmers has been recognized for its quality at local, state (state fair and Kentucky Alfalfa Conference), and national (American Forage and Grassland Council) hay contests. The testing records of the Kentucky Department of Agriculture also document the high quality alfalfa hay of Kentucky. However, little has been written about the farm practices used to produce high quality alfalfa hay in Kentucky. The current practices of top hay growers may be helpful in defining the options available to …


Are We Making Progress With Hay Quality In Kentucky?, Buddy Sims Feb 1996

Are We Making Progress With Hay Quality In Kentucky?, Buddy Sims

Kentucky Alfalfa and Stored Forage Conference

During the Kentucky State Fair, Garry Lacefield asked if I would be on the XVI Kentucky Alfalfa Conference program. Certainly I never miss an opportunity to talk, especially about testing forages. Then in October we communicated again and it was decided that my topic would be "Are We Making Progress With Hay Quality in Kentucky?" Seems like a simple yes or no question! Well ... l elected to think about this under the middle of December. Of course, during this time, the people of the Commonwealth elected a new Commissioner of Agriculture. Your selection was Billy Ray Smith, who throughout …


Role Of Alfalfa In Our Farming Operation, Larry Jeffries Feb 1996

Role Of Alfalfa In Our Farming Operation, Larry Jeffries

Kentucky Alfalfa and Stored Forage Conference

Our farming operation consists of 214 acres. We raise 14,000 pounds of tobacco, have a purebred beef cattle herd, and sell hay. Alfalfa is the only one of the three sources of income that we can project an increase for 1996.

Our alfalfa cash hay sales have increased for several years due to the increase of suburban horse owners in the Louisville area.

I think it is important to have a written plan for 1996. We wouldn't think of making a long trip without a map, especially into strange territory - we farmers are in strange territory. If you don't …


Utilizing Alfalfa Hay In Horse Diets, Laurie Lawrence Feb 1996

Utilizing Alfalfa Hay In Horse Diets, Laurie Lawrence

Kentucky Alfalfa and Stored Forage Conference

All horses need fiber in their diets. Forages, usually as pasture or hay, are the primary sources of fiber in most rations. The exact amount of hay that a horse will eat on a daily or yearly basis will depend on the size of the horse, the class of the horse (pregnant, working, etc) and the type of hay being fed. The type and amount of other feeds in the ration will also impact the amount of hay consumed, but in general, horse owners/managers should try to maximize forage intake and then supplement with grain or other feeds to meet …


Advances In Harvesting And Storing High Quality Alfalfa, Michael Collins Feb 1996

Advances In Harvesting And Storing High Quality Alfalfa, Michael Collins

Kentucky Alfalfa and Stored Forage Conference

On suitable soils, alfalfa produces the highest yields of dry matter and nutrients possible under Kentucky conditions. Limitations to achievement of this potential are often related to losses that occur during alfalfa harvest and storage. We have conducted a number of studies addressing technologies designed to minimize the extent of these losses.


Fencing And Watering Systems For Grazing Alfalfa, Larry Turner Feb 1996

Fencing And Watering Systems For Grazing Alfalfa, Larry Turner

Kentucky Alfalfa and Stored Forage Conference

Controlled or rotational grazing can result in better utilization of the forage resources on your farm. By better forage management through controlled grazing, you can increase profitability of cattle/forage systems. To effectively develop a controlled grazing system, however, fencing must be used to subdivide the pasture into sub-fields or paddocks. The animals may then be rotated among the paddocks to optimize forage and beef or dairy production from the system. Alfalfa grazing can play an important part in such a system. By using alfalfa, additional grazing management options are available, including avoiding high-endophyte fescue in hot summer periods thereby gaining …


Opportunities For Alfalfa As A Grazing Crop In Kentucky, Ken Johnson Feb 1996

Opportunities For Alfalfa As A Grazing Crop In Kentucky, Ken Johnson

Kentucky Alfalfa and Stored Forage Conference

As we think about the possibilities of alfalfa as a grazing crop, maybe we need to look at some of the limitations and where alfalfa may fit into Kentucky producers programs.

When looking at Kentucky's land area of 25 million acres we see that nearly half is in woodland. Of the 12 million acres remaining; about 3 million is in row crops, 2 million in hay, 2 million in non farm uses, and the rest is pasture. That is about 5 million acres in pasture or at least available to the pastured. With at least 7 million acres in hay …


Grazing Alfalfa: Putting The Puzzle Together, Garry D. Lacefield, Jimmy C. Henning, David Stalion Feb 1996

Grazing Alfalfa: Putting The Puzzle Together, Garry D. Lacefield, Jimmy C. Henning, David Stalion

Kentucky Alfalfa and Stored Forage Conference

Interest in alfalfa as a grazing crop has increased dramatically over the past decade. There are many research and demonstrations being conducted in Kentucky and across the U.S. as we continue to investigate and learn more about alfalfa's role in forage-based livestock production.

Listed below are some of the reasons farmers, researchers and agribusiness personnel are excited about the opportunity for alfalfa as a grazing crop.


Foreword [1996], Garry D. Lacefield, Christi L. Forsythe Feb 1996

Foreword [1996], Garry D. Lacefield, Christi L. Forsythe

Kentucky Alfalfa and Stored Forage Conference

This is the front matter of the proceedings.


Polarization Of Astronomical Maser Radiation. Iii. Arbitrary Zeeman Splitting And Anisotropic Pumping, Moshe Elitzur Jan 1996

Polarization Of Astronomical Maser Radiation. Iii. Arbitrary Zeeman Splitting And Anisotropic Pumping, Moshe Elitzur

Physics and Astronomy Faculty Publications

General solutions of the maser polarization problem are presented for arbitrary absorption coefficients. The results are used to calculate polarization for masers permeated by magnetic fields with arbitrary values of χB, the ratio of Zeeman splitting to Doppler linewidth, and for anisotropic (m-dependent) pumping. In the case of magnetic fields, one solution describes the polarization for overlapping Zeeman components, χB < 1. The χB → 0 limit of this solution reproduces the linear polarization derived in previous studies, which were always conducted at this unphysical limit. Terms of higher order in χB have a negligible effect on …


1x27 Cartoons About Science, Mark S. Coyne Jan 1996

1x27 Cartoons About Science, Mark S. Coyne

Plant and Soil Sciences Faculty Book Gallery

A tongue-in-cheek look at the world of natural science.


Theoretical Hei Line Intensities In Gaseous Nebulae: Ngc 1976, 6572 And Ic 4997, J. B. Kingdon, Gary J. Ferland Jan 1996

Theoretical Hei Line Intensities In Gaseous Nebulae: Ngc 1976, 6572 And Ic 4997, J. B. Kingdon, Gary J. Ferland

Physics and Astronomy Faculty Publications

Smits has recently calculated theoretical He I intensities for a large number of lines for conditions appropriate to gaseous nebulae. These are likely to remain the definitive calculations for some time to come. A comparison of these line ratios with observed values in three nebulae reveals some discrepancies. We show that these discrepancies are reduced when collisional effects from the metastable 23S level are included, and that it is not necessary to invoke an unknown depopulation mechanism for the He I23S level.


Infiltration Of Fecal Bacteria Through Soils: Timing And Tillage Effects, Mark S. Coyne, C. S. Stoddard, John H. Grove, William O. Thom Jan 1996

Infiltration Of Fecal Bacteria Through Soils: Timing And Tillage Effects, Mark S. Coyne, C. S. Stoddard, John H. Grove, William O. Thom

Soil Science News and Views

Land-applying animal wastes potentially exposes humans and animals to fecal pathogens, either by direct contact with soil and produce, or via ground water contamination. Some of these organisms are Salmonella, certain pathogenic Escherichia coli strains, protozoa such as Cryptosporidium and Giardia, and enteric viruses. Whether soil adequately filters these pathogens before they reach ground water depends on the interaction of porosity, texture, depth, water content, rainfall intensity and duration, and soil management.


No-Tilling Corn Into Hairy Vetch: Fertilizer Nitrogen Substitution Without Penalty Due To Delayed Planting, H. M. Saha, John H. Grove Jan 1996

No-Tilling Corn Into Hairy Vetch: Fertilizer Nitrogen Substitution Without Penalty Due To Delayed Planting, H. M. Saha, John H. Grove

Soil Science News and Views

Previous studies conducted in Kentucky have shown that hairy vetch is an agronomically viable winter legume cover crop for notill corn production. However, to fully realize the benefits of this cover crop it is necessary to allow enough time for it to accumulate biomass and nitrogen (N) before no-till corn is planted. Thus, early corn planting may not always be feasible. Since delaying corn planting after May 15 in Kentucky usually leads to a decline in corn grain yields, the main question addressed in this study (one for which little information was available) was whether the benefits provided by hairy …


Fertility Status And Changes Of 50 Crp Fields, Lloyd W. Murdock, Dottie Call Jan 1996

Fertility Status And Changes Of 50 Crp Fields, Lloyd W. Murdock, Dottie Call

Soil Science News and Views

The CRP program in Kentucky has 435,000 acres ofland which will be released soon. Since these fields were highly eroded when they were placed into the program, it was felt it would be helpful to determine the general fertility status of the CRP fields in Kentucky and see what changes had taken place during their years of enrollment in the CRP program. Since most of the fields had a previous erosive history, we expected the fields to be low in pH and in the low to medium range for phosphorus and potassium.

We would like to thank the producers who …


Seeding Cover Crops In Kentucky, Kenneth L. Wells, Morris J. Bitzer Jan 1996

Seeding Cover Crops In Kentucky, Kenneth L. Wells, Morris J. Bitzer

Soil Science News and Views

The most common reason for seeding a cover crop is to establish cover onto a tilled area following harvest of the previous crop, or onto a disturbed area for a "critical seeding", as soon as possible after tillage or disturbance. The reason for establishing the cover crop is to stabilize the exposed surface of bare soil to prevent erosion.


Cambrian Hydrocarbon Potential Indicated In Kentucky's Rome Trough, David C. Harris, James A. Drahovzal Jan 1996

Cambrian Hydrocarbon Potential Indicated In Kentucky's Rome Trough, David C. Harris, James A. Drahovzal

Information Circular--KGS

A recent gas discovery in the Rome Trough has resulted in a new phase of deep exploration in eastern Kentucky. This activity is located in Elliott County, near the northern boundary fault of the Cambrian Rome Trough graben. The Carson Associates No. 1 Kazee well was drilled in 1994, and blew out with a reported uncontrolled flow of 11 million cubic feet of gas per day. Although completed at a much lower rate, this well renewed interest in the deep gas potential of the Rome Trough, which has seen sporadic drilling activity since the 1940's. Gas production in the Rome …