Physical Sciences and Mathematics Commons^™

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

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

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.

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 …

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.

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 …

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 …

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 …

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 …

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 (z_em = 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

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

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 …

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 χ_B, 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, χ_B < 1. The χ_B → 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 χ_B have a negligible effect on …

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

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

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

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

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

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 …

The Middle And Upper Ordovician Bioclastic Carbonate ("Trenton") Play In The Appalachian Basin, Brandon C. Nuttall

Information Circular--KGS

The bioclastic carbonate play in the Appalachian Basin (referred to by drillers as the "Trenton") includes both gas and oil produced from Middle and Upper Ordovician stratigraphic and combination traps in linear reservoirs often mistaken for reefs. While production from this play is currently reported from nine fields in south-central and eastern Kentucky and five fields in New York, potential reservoir rocks are present throughout most of the Appalachian Basin from New York to Tennessee. Along the western flank of the Appalachian Basin, in the Blue Grass Region of central Kentucky, Middle and Upper Ordovician strata crop out. In the …

Vegetative Filter Strip Design For Grassed Areas Treated With Animal Manures, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr.

Biosystems and Agricultural Engineering Faculty Publications

Vegetative filter strips (VFS) are a low-cost management option that have been demonstrated to be effective in reducing runoff transport of fertilizer constituents applied to grassed areas (pasture or meadow). Runoff quality studies involving fertilizers applied to grassed areas suggest that VFS can be designed by assuming that (1) only infiltration is responsible for pollutant removal, (2) the first post-application runoff event is most important from a water quality perspective (enabling a design event approach), and (3) no pollutant build-up that degrades VFS performance will occur. The purpose of this study was to develop a VFS design algorithm for grassed …

Poultry Litter-Treated Length Effects On Quality Of Runoff From Fescue Plots, Dwayne R. Edwards, Philip A. Moore Jr., Tommy C. Daniel, Puneet Srivastava

Biosystems and Agricultural Engineering Faculty Publications

Using experimental data and/or mathematical simulation models to identify practices that reduce pollution from manure-treated areas is sometimes perceived as limited by the unknown validity of extrapolating plot-scale data to larger areas and by uncertainties in modeling transport of various pollutants. The objectives of this study were to assess the effect of length of manure treatment on runoff concentrations of poultry litter constituents and to define the modes of transport (particulate versus soluble) for nitrogen (N), phosphorus (P), carbon (C), and solids. Poultry litter was applied to three 1.5- x 18.3-m fescue (Festuca arundinacea Schreb.) plots with runoff collection …

Quality Of Runoff From Four Northwest Arkansas Pasture Fields Treated With Organic And Inorganic Fertilizer, Dwayne R. Edwards, Tommy C. Daniel, John F. Murdoch, Philip A. Moore Jr.

Biosystems and Agricultural Engineering Faculty Publications

Long-term land application of animal manures, even at agronomic rates, can promote accumulation of soil phosphorus (P) which can, in turn, contribute to increased P loadings to downstream waters. The objective of this study was to assess the soil and runoff effects of replacing animal manure as a soil amendment with inorganic fertilizer (ammonium nitrate, NH₄NO₃) on fields that had been treated previously with animal manures. Runoff from two pairs of small fields (0.57 to 1.46 ha) was sampled from September 1991 to April 1994. All fields had been treated previously with animal manures; after runoff …

Performance Of Vegetative Filter Strips With Varying Pollutant Source And Filter Strip Lengths, Puneet Srivastava, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr., Thomas A. Costello

Biosystems and Agricultural Engineering Faculty Publications

Vegetative filter strips (VFS) can reduce runoff losses of pollutants such as nitrogen (N) and phosphorus (P) from land areas treated with fertilizers. While VFS effectiveness is considered to depend on lengths of pollutant source and VFS areas, there is little experimental evidence of this dependence, particularly when the pollutant source is manure-treated pasture. This study assessed the effects of pollutant source area (fescue pasture treated with poultry litter) length and VFS (fescue pasture) length on VFS removal of nitrate N (NO₃-N), ammonia N (NH₃-N), total Kjeldahl N (TKN), ortho-P (PO₄-P), total P (TP), …

Simulation Of Runoff Transport Of Animal Manure Constituents, Yang Wang, Dwayne R. Edwards, Tommy C. Daniel, H. Don Scott

Biosystems and Agricultural Engineering Faculty Publications

Runoff losses of land-applied animal manure constituents can adversely affect the quality of downstream waters. Reliable mathematical simulation models can help estimate runoff losses of animal manure constituents and identify management measures to reduce these losses. The objective of this study was to develop and calibrate an event-based simulation model to describe the runoff transport of solids (soil and manure particles) and nutrients (nitrogen and phosphorus) from areas treated with animal manure. The resulting model, consisting of linked hydrology, soil/manure transport, and nutrient transport components, is process-oriented and uses measurable parameters to the greatest degree possible. The three components of …

A Direct, Approximate Solution To The Modified Green-Ampt Infiltration Equation, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards

Biosystems and Agricultural Engineering Faculty Publications

Accurately predicting the rainfall-runoff process is of vital importance for water quality models as well as for correct design of various types of hydraulic structures. This article presents a method of describing the cumulative infiltration process as an explicit function of time using an approximation to the modified Green-Ampt equation given by Mein and Larson (1971). The resulting equation is helpful in predicting cumulative infiltration and therefore infiltration capacity for computer simulation models. The proposed method takes about 50% less time than the usual iterative technique for the same degree of accuracy. The maximum error due to approximation was 1% …

Minimum Ventilation For Modern Broiler Facilities, Richard S. Gates, Douglas G. Overhults, Shuhui H. Zhang

Biosystems and Agricultural Engineering Faculty Publications

New functions for whole-house broiler heat production as a function of bird age using modern straight run broiler growth rates are presented and compared to values in the literature. The approximations are based on field measurements of environmental conditions in modern broiler housing, using a technique that matches predicted to actual fuel use to estimate partitioning between latent and sensible heat. Development of a program utilizing these approximations to compute ventilation and heating requirements for temperature and humidity control in broiler housing is described. The program utilizes steady-state heat and moisture balances commonly used for design purposes, with hourly or …

Application Of Simplified Phosphorus Transport Models To Pasture Fields In Northwest Arkansas, Dwayne R. Edwards, C. T. Haan, Andrew N. Sharpley, John F. Murdoch, Tommy C. Daniel, Philip A. Moore Jr.

Biosystems and Agricultural Engineering Faculty Publications

Runoff transport of phosphorus (P) is often predicted from simple equations with parameters determined from data applicable primarily to row-cropped and fallow cover conditions. The applicability, accuracy, and precision of such P transport prediction equations under pasture situations are less well defined. The objectives of this study were to determine parameters of simplified runoff P transport equations for pasture fields and to assess the accuracy and precision of the equations. Runoff, sediment yield, soluble P transport, and particulate P transport data were collected from four pasture fields in northwestern Arkansas. Runoff event enrichment ratios and extraction coefficients were computed, and …

Evaluation Of The Crop Growth Component Of The Root Zone Water Quality Model For Corn In Ohio, Sue E. Nokes, Feliks M. Landa, Jon D. Hanson

Biosystems and Agricultural Engineering Faculty Publications

The Root Zone Water Quality Model (RZWQM) is a computer model developed to simulate water, chemical, and biological processes in the root zone of agricultural management systems. As of this writing RZWQM is in the beta-testing phase of development. This article reports on a parameterization and evaluation study performed in Ohio on field corn for the crop growth component of RZWQM. The generic crop growth model in RZWQM had not previously been parameterized or tested on field corn. This article reports the results of such a study. One year of data was used to calibrate RZWQM, and two additional years …

Comparison Of Daily Water Table Depth Prediction By Four Simulation Models, Eric D. Desmond, Andrew D. Ward, Norman R. Fausey, Stephen R. Workman

Biosystems and Agricultural Engineering Faculty Publications

The Agricultural Drainage And Pesticide Transport (ADAPT) model was compared to the water management simulation models DRAINMOD, SWATREN, and PREFLO. SWATREN and PREFLO are one-dimensional finite-difference models while ADAPT and DRAINMOD are one-dimensional mass balance models. ADAPT, an extension of the computer model GLEAMS, also provides chemical transport information. All four models were tested against field data from Aurora, North Carolina. Observed water table depth data were collected during 1973 through 1977 from a water table management field experiment with three subsurface drain spacing treatments of 7.5, 15, and 30 m.

Both the standard error of estimate and the average …