Physical Sciences and Mathematics Commons^™

Locally Optimally Emitting Clouds And The Origin Of Quasar Emission Lines, Jack Baldwin, Gary J. Ferland, Kirk Korista, Dima Verner

Physics and Astronomy Faculty Publications

The similarity of quasar line spectra has been taken as an indication that the emission line clouds have preferred parameters, suggesting that the environment is subject to a fine-tuning process. We show here that the observed spectrum is a natural consequence of powerful selection effects. We computed a large grid of photoionization models covering the widest possible range of cloud gas density and distance from the central continuum source. For each line only a narrow range of density and distance from the continuum source results in maximum reprocessing efficiency, corresponding to "locally optimally emitting clouds" (LOCs). These parameters depend on …

Broad Ne Viii Λ744 Emission From The Quasar Pg 1148+549, Fred Hamann, Joseph C. Shields, Gary J. Ferland, Kirk T. Korista

Physics and Astronomy Faculty Publications

We discuss the probable detection of broad Ne VIII λ774 emission from the z_ɛ = 0.978 quasar PG 1148+549, and we use spectral synthesis calculations to study the physical conditions in the line-forming gas. The theoretical predictions and the measured line wavelength both support Ne VIII λ774 as the most likely identification.

Our calculations show that Ne VIII λ774 forms in hotter and more highly ionized gas than previously recognized in the broad emission line region. If the gas is photoionized by a standard active galactic nucleus continuum, the observed Ne VIII equivalent width, the Ne VIII/O VI flux …

The Geometry And Kinematics Of The Broad-Line Region In Ngc 5548 From Hst And Iue Observations, Ignaz Wanders, Mike R. Goad, Kirk T. Korista, Bradley M. Peterson, Keith Horne, Gary J. Ferland, Anuradha P. Koratkar, Richard W. Pogge, Joseph C. Sheilds

Physics and Astronomy Faculty Publications

The spatial and radial velocity distribution of broad-line-emitting gas in the Seyfert 1 galaxy NGC 5548 is examined through the process of reverberation mapping, which is done by detailed comparison of continuum and emission-line variations. Recent spectroscopic monitoring of NGC 5548 with HST and IUE allows us to resolve the "transfer function" (TF) that relates the continuum and emission-line variability. We also examine the radial velocity-resolved TFs, and confirm that predominantly radial motions of the line-emitting clouds can be excluded. We find that a broad-line region comprised of clouds that are orbiting a central source of mass ~10⁸ M …

Groundwater Study: Toyota Motor Manufacturing, Usa Georgetown, Kentucky, Gary Felton, Lyle V. A. Sendlein, Teri Dowdy, Daryl Hines

KWRRI Research Reports

An eighteen month study of the Toyota Motor Manufacturing (TMM) plant site and the surrounding area was undertaken. The basic charge for this project was to characterize the groundwater that is potentially impacted by the TMM plant site. This included occurrence, flow direction, and, if possible, velocity. Because the area is karstified (has sinkholes, springs, caves, etc.) surface water and groundwater are intimately connected and, hence, surface water was frequently an important component of this work.

Data from TMM construction plans and monitoring work done subsequent to construction were elicited from the various repositories within the TMM infrastructure. Aerial color …

Temperature Fluctuations In Photoionized Nebulae, J. B. Kingdon, Gary J. Ferland

Physics and Astronomy Faculty Publications

Recombination lines in gaseous nebulae frequently yield parent-ion abundances that are several times larger than abundances derived from forbidden lines. One possible explanation for this discrepancy is the presence of temperature fluctuations. We examine temperature fluctuations in model nebulae by utilizing Peimbert's t² parameter. We have run large grids of models, varying the stellar temperature and the total hydrogen density. We consider two abundance sets: The first uses "typical" planetary nebulae abundances, while the second examines the effect of increasing the metals and grains by a factor of 3. We also consider both a constant density distribution and one …

Detection Of Alzheimer's Disease And Other Diseases Using An Improved Photoaffinity Labeling Method, Boyd E. Haley

Chemistry Faculty Patents

An improved method for diagnosing a disease comprising detecting a disease-specific biochemical marker macromolecule within a sample of extracted cerebral spinal fluid or serum is disclosed. In particular, a radioactively labeled photoaffinity probe is used to diagnose a disease. For instance, Alzheimer's disease can be diagnosed by detecting a disease-specific protein having a molecular weight of about 42,000 daltons, i.e., glutamine synthetase. Also included is a method for detecting other disease states, such as cancer, by detecting the presence or absence of specific nucleotide binding proteins.

The Hubble Space Telescope Sample Of Radio-Loud Quasars: The LyΑ/HΒ Ratio, Hagai Netzer, M. S. Brotherton, Beverley J. Wills, Mingsheng Han, D. Wills, J. A. Baldwin, Gary J. Ferland, I. W. A. Browne

Physics and Astronomy Faculty Publications

We have used the first Hubble Space Telescope Faint Object Spectrograph spectra of our sample of radio- loud quasars, and quasi-simultaneous ground-based spectrophotometry, to investigate the intensity ratio Lyα/Hβ, whose small observed values are one of the outstanding problems of active galactic nuclei research. The present sample of 20 quasars with complete flux and profile data shows the first significant correlations of this ratio with other observed properties. The strongest correlations are with various continuum slope indicators: we find smaller Lyα/Hβ ratios in quasars whose continua rise more steeply into the red. The …

The Hubble Space Telescope Sample Of Radio-Loud Quasars: Ultraviolet Spectra Of The First 31 Quasars, Beverley J. Wills, Keith L. Thompson, Mingsheng Han, H. Netzer, D. Wills, J. A. Baldwin, Gary J. Ferland, I W. A. Browne, M. S. Brotherton

Physics and Astronomy Faculty Publications

We report the first results from a continuing program to investigate the multifrequency spectrophotometric and other properties of a sample of about 50 radio-loud quasars in the redshift range ˜0.3-1.3. Here we present spectrophotometric data of high signal-to-noise ratio (≳20 in the continuum) of the first 31 radio-loud quasars, over the wavelength range from below Lyα to an observed wavelength of 3250 or 4800 Å, obtained using the Faint Object Spectrograph on the Hubble Space Telescope. We have also made quasi-simultaneous observations to extend these spectra beyond the Balmer lines -- either Hβ or Hα -- …

Infrared Emission And Dynamics Of Outlfows In Late-Type Stars, Željko Ivezić, Moshe Elitzur

Physics and Astronomy Faculty Publications

The dynamical structure and infrared emission of winds around late-type stars are studied in a self-consistent model that couples the equations of motion and radiative transfer. Thanks to its scaling properties, both the dynamics and IR spectrum of the solution are fully characterized by τ_F, the flux-averaged optical depth of the wind. Five types of dust grains are considered: astronomical silicate, crystalline olivine, graphite, amorphous carbon and SiC, as well as mixtures. Analysis of infrared signatures provides constraints on the grain chemical composition and indications for the simultaneous existence of silicate and carbon grains. The abundances of crystalline …

Collisional Effects In He I: An Observational Analysis, J. B. Kingdon, Gary J. Ferland

Physics and Astronomy Faculty Publications

Accurate and reliable helium abundances can test modern theories of galactic and primordial nucleosynthesis. Unfortunately, there is some question whether current theory can account for collisional contributions to He I. We present new observations of two planetary nebulae (PNs) in the range λ850-λ9650, which we use to assess the importance of collisonal effects in the He I spectrum. The first object, NGC 7027, is expected to show relatively strong collisional enhancement, while the second, NGC 7026, should display only small effects. We derive new collision-to-recombination correction factors, based on new collision strengths from the 29-state quantal calculation …

Optically Thin Broad-Line Clouds In Active Galactic Nuclei, Joseph C. Shields, Gary J. Ferland, Bradley M. Peterson

Physics and Astronomy Faculty Publications

The broad-line region (BLR) in Seyfert galaxy nuclei exhibits correlated variations in continuum and emission-line luminosity that are qualitatively consistent with photoionization of ionization-bounded (optically thick) clouds. However, evidence is growing that a nonnegligible fraction of the BLR cloud population is optically thin to the Lyman continuum and fully ionized in hydrogen. We consider the implications of this nebular component for observed line emission and find that inclusion of thin clouds in photoionization calculations can resolve several outstanding puzzles of Seyfert variability, notably the behavior of the C IV λ1549/Lyα ratio as a function of continuum luminosity.

A …

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 …

How To Make Your Alfalfa More Profitable, Clive Holland

Kentucky Alfalfa and Stored Forage Conference

As a perennial plant, alfalfa can be expected to continue to live and produce for an indefinite period of time. Why then do stands need to be replanted every few years? Is modern seed available today, weakened and unable to live up to the perennial label? What about yield? How does your stand measure up? Are you barely making the state average, or struggling to even meet this modest yield level?

The first harvest each spring can produce over 40% of the yield in a single growing season. Why is a stand slower growing in the spring than you would …

Role Of Alfalfa In Animal Diets, Jennifer L. Garrett

Kentucky Alfalfa and Stored Forage Conference

Alfalfa forage use has increased in all classes of livestock - dairy, beef, horses, sheep, and swine - during the last 40 years. The highest utilization of alfalfa by livestock is found in dairy cattle diets. Additionally, the use of alfalfa as a grazing crop has also undergone a considerable increase with the use of new grazing management techniques and the development of new grazing varieties.

Alfalfa's strength as a forage crop is its high nutritional value. Alfalfa is higher in protein, minerals, and net energy than grasses and small grains. High quality alfalfa also helps to promote intake, especially …

Saving Those Valuable Leaves During Haymaking, Michael Collins

Kentucky Alfalfa and Stored Forage Conference

Field dry hay needs to be reduced from near 80% moisture to 20% or less to prevent spoilage during storage. Drying hay to safe baling moistures often takes several days. Sources of loss during forage harvest include mechanical losses such as mowing, conditioning, chopping, raking, packaging and handling as well as respiration and leaching. The general relationship between forage moisture concentration at harvest and losses during the field and storage phases is shown in Figure 1. Harvest losses are greatest for very dry forage and are low for very wet material like direct cut silage. However, the latter is subject …

Alfalfa As A Grazing Crop: Progress Continues, Garry D. Lacefield

Kentucky Alfalfa and Stored Forage Conference

This makes the third consecutive year that I have talked about "Alfalfa as a Grazing Crop". At our XIII Kentucky Alfalfa, I, along with five other speakers, discussed several aspects of grazing alfalfa and all agreed that the concept had tremendous potential.

This past year I reviewed some of the discussion of our XIII Conference and shared some of the activities going on in research and educational programs throughout the region. In addition, I announced the date for a National Alfalfa Grazing Conference to be held in Nashville, Tennessee. The Conference was held July 29 and was a big success. …

Control Of Johnsongrass And Other Weedy Grasses In Alfalfa, Jonathan D. Green

Kentucky Alfalfa and Stored Forage Conference

Johnsongrass is considered one of the major weed species that infests alfalfa in Kentucky. Other weedy grasses such as large crabgrass, foxtails, barnyard grass, and fall panicum can also interfere with alfalfa production. Low infestation levels of these grasses may not create significant concern, but high infestation levels can result in reduced yield, alfalfa hay quality, and/or shorten the life of the stand.

Opportunities For No-Till Alfalfa In Kentucky, Jimmy C. Henning, Garry D. Lacefield, Andy Anderson

Kentucky Alfalfa and Stored Forage Conference

There is a rising interest in the use of alfalfa in pastures, especially for dairy cattle, beef stockers and as supplemental summer grazing for cows with calves. Kentucky has the land resource to support 2 million acres of alfalfa without reducing acres in cultivated crops. Acres of alfalfa seeded for pasture use would be in addition to the 350,000 acres presently used primarily for hay. However, these additional acres are rolling and erodible and therefore alfalfa should be established by no-till methods.

Establishing Alfalfa Following Alfalfa: How Long Do We Wait?, Monroe Rasnake

Kentucky Alfalfa and Stored Forage Conference

It has long been recommended that alfalfa fields be rotated to another crop such as com for at least one growing season before reestablishing alfalfa. One reason for doing this is that insect and disease levels build up in the old alfalfa and this time is needed to allow them to die out. Another reason is that alfalfa plants have been shown to produce compounds that inhibit the germination and growth of new alfalfa seedlings. This is called autotoxicity or allelopathy.

Recently researchers from other states have indicated that it may not be necessary to have a full growing season …

Foreword [1995], Garry D. Lacefield, Christi L. Forsythe

Kentucky Alfalfa and Stored Forage Conference

This is the front matter of the proceedings.

On The Current Status Of Maser Polarization Theory, Moshe Elitzur

Physics and Astronomy Faculty Publications

Despite recent criticism, past conflicts among theoretical studies of maser polarization are by now resolved and clarified. All analytical methods proposed thus far produce the same polarization solutions, solutions that agree with observations. Current numerical studies do not reproduce these solutions. Instead, for any pumping employed, their results are in direct conflict with both analytical theory and observations. These problems reflect the fact that the basic formulation of numerical modeling has yet to incorporate the statistical nature of the radiation field.

Grains In Ionized Nebulae: Spectral Line Diagnostics, J. B. Kingdon, Gary J. Ferland, W. A. Feibelman

Physics and Astronomy Faculty Publications

The depletion of condensable elements onto grains in gaseous nebulae can provide evidence that dust is well mixed with the ionized gas. Al and CA are two of the most depleted elements in the general interstellar medium, and it is therefore important to measure their abundances within the ionized region of nebulae. We compute a large grid of photoionization models and identify sets of line ratios which are relatively insensitive to stellar and nebular parameters, and are thus excellent diagnostics for determining relative abundances. Based on the absence of the [Ca II] λλ7291, 7324 doublet and the detection of …

The Origin Of N Iii Λ990 And C Iii Λ977 Emission In Agn Narrow-Line Region Gas, Jason W. Ferguson, Gary J. Ferland, A. K. Pradham

Physics and Astronomy Faculty Publications

We discuss implications of Hopkins Ultraviolet Telescope (HUT) detections of C III λ977 and N III λ990 emission from the narrow-line region of the Seyfert 2 galaxy NGC 1068. In their discovery paper Kriss et al. showed that the unexpectedly great strength of these lines implies that the emitting gas must be shock-heated if the lines are collisionally excited. Here we investigate other processes which excite these lines in photoionization equilibrium. Recombination, mainly dielectronic, and continuum fluorescence are strong contributors to the line. The resulting intensities are sensitive to the velocity field of the emitting gas and require …

Interpreting Soils Maps, Kenneth L. Wells

Soil Science News and Views

A knowledge of the nature andaracteristics of soils on a farm is basic to farm planning so as to properly match crops and soils and minimize the effect of soil variation on crop production and economic return. This information also provides a realistic basis for estimating crop yields on a field-by-field basis, a planning step necessary in estimating anticipated costs and returns. Detailed soils maps which have been prepared by soil scientists identify the various soil series which occur on the landscape, and show the slope of the landscape on which they occur, as well as the amount of topsoil …

An Assessment Of Water Sources Related To Major Systems Of Agricultural Land Use In Kentucky, Robert L. Blevins, Gerald R. Haszler, Grant W. Thomas, Kenneth L. Wells, William W. Witt

Soil Science News and Views

Recent years have seen a greater public concern about the quality of the nation's water resources. While initial concerns targeted point source pollution, the emphasis in recent years has shifted to non-point source pollution, including the effect of general practices used by fanners in agricultural production systems. Since there was no reliable data base on such effects for Kentucky, the state's General Assembly passed legislation during its 1990 session directing the University ofKentucky's College of Agriculture (UK.CA) to assess the effect of agricultural practices on quality of the state's waters. As part of the efforts undertaken by the UKCA in …

Returning Crp Land To Grain Production, Wilbur Frye, Lloyd W. Murdock

Soil Science News and Views

Land that was contracted into the Conservation Reserve Program (CRP) was committed to the program for 10 years. The first contracts expire in September 1995, but USDA has already authorized a one-year extension of those contracts. Unless Congress extends the program in the 1995 Farm Bill the contracts will begin expiring on September 30, 1996, as the 10- year period elapses, and continuing until all of the acres that were set aside in the program are released. In Kentucky, about 440,000 acres were contracted in the program from 1986 to 1992. Most of the land is highly erodible, and farmers …

No Tillage Adoption In Grain Crops In Kentucky Counties In 1994, Gerald R. Haszler, Grant W. Thomas

Soil Science News and Views

The no-tillage system, where soils are neither tilled nor cultivated, has a number of advantages. Studies in Kentucky and in other states show much lower erosion under no tillage as compared with conventional tillage. In addition, fuel, machinery, and time savings are all impressive when the no-tillage system is used. There is also a tendency toward better crop yields due to higher water capture and/or conservation that is associated with the mulch of crop residues that is maintained on the soil surface in no tillage.

Should Burley Tobacco Farmers Be Concerned About High Rates Of Nitrogen Fertilizers?, Robert C. Pearce, Gary K. Palmer

Soil Science News and Views

The use of nitrogen (N) fertilizer for tobacco production is necessary because (1) tobacco takes up sizable amounts of N, and (2) most soils cannot provide adequate amounts of N. Rates of fertilizer N recommended by the University of Kentucky for burley tobacco production vary based on past cropping history, and under certain conditions can be as high as 350 lbs. N/A However, since tobacco is a high value crop, and profit margins are high, farmers often apply more N than is recommended as insurance against crop losses. The perception of widespread over-application of fertilizer N has resulted in increased …

Weed Seed In Poultry Litter: Should Farmers Be Concerned, Monroe Rasnake

Soil Science News and Views

Over the years, I have received many calls from farmers who have had unusual weed problems in their fields. Their first thoughts normally are that weed seeds were brought to the fields in crop seed, hay, manure, etc. Some of the same concern has been expressed in regard to using poultry litter on fields. As poultry litter becomes available to more Kentucky farmers, should they be concerned about the possibility it would contain weed seed? The simple answer to the question is "NO" in most situations.

The Effect Of Organic Matter On Maximum Compactability Of Soil, Grant W. Thomas, Gerald R. Haszler, Robert L. Blevins

Soil Science News and Views

Bulk density is the weight of a given volume of soil expressed by soil scientists as grams per cubic centimeter (g/cm3). The higher the bulk density, the lower the volume of soil occupied by pore space, that volume of soil in which air and water reside. Because of this, there is much interest on the degree to which soil can be compacted.

The Proctor test is a means of determining the maximum bulk density that can be attained in a soil sample. This "maximum compactibility" is widely used on highways and building foundations but has had little use in agricultural …