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Articles 11701 - 11730 of 12002
Full-Text Articles in Physical Sciences and Mathematics
Bowen Fluoresence And He Ii Lines In Active Galaxies And Gaseous Nebulae, Hagai Netzer, Moshe Elitzur, Gary J. Ferland
Bowen Fluoresence And He Ii Lines In Active Galaxies And Gaseous Nebulae, Hagai Netzer, Moshe Elitzur, Gary J. Ferland
Physics and Astronomy Faculty Publications
We have calculated the intensity of He II and the O III and N III Bowen lines under a variety of astrophysical conditions. Our line-transfer method is based on the escape probability formalism and is especially suitable for combining line fluorescence and photoionization calculations in a simple, straightforward way. It reproduces the results of the more sophisticated line-transfer calculations quite accurately and is much better for producing realistic ionization and thermal structures. An extensive grid of models is presented and discussed, with special emphasis on the case of active galactic nuclei (AGNs). Many O III and N III Bowen lines …
Use Of Nitrification Inhibitors On Wheat, Lloyd W. Murdock
Use Of Nitrification Inhibitors On Wheat, Lloyd W. Murdock
Soil Science News and Views
Nitrogen is one of the most important inputs 1in wheat production, but sometimes one of the most difficult to manage. Sources of nitrogen commonly used in Kentucky have most or all of their nitrogen in the ammonium (NH+4) form or forms readily converted to NH+4 (anhydrous ammonia 100%, urea 100%, N-solutions 75%, ammonium nitrate 50%), The ammonium form of nitrogen is used by the plant and retained in the soil with little chance 2f loss, In soils with temperatures above 50°F the ammonium is converted to the nitrate (NO3) form of nitrogen. Nitrate …
Modeling Soil Erosion With Emphasis On Steep Slopes And The Rilling Process, Michael C. Hirschi, Billy J. Barfield, Ian D. Moore
Modeling Soil Erosion With Emphasis On Steep Slopes And The Rilling Process, Michael C. Hirschi, Billy J. Barfield, Ian D. Moore
KWRRI Research Reports
A soil erosion model, known as KYERMO, was developed for use in soil erosion research. The model was written in Microsoft FORTRAN, which is a subset of the ANSI FORTRAN 77 standard, allowing the model to be run on an IBM-PC as well as a mainframe computer. The model structure consisted of many interrelated subroutines which facilitated model development, testing, and future expansion.
A sensitivity analysis of the detachment component was performed, examining the number of rills, the number of space and time steps, and the detachment parameters. This analysis indicated that the model performed as expected for the detachment …
Reductive Dechlorination Of Toxic Chlorocarbons, K. Grant Taylor
Reductive Dechlorination Of Toxic Chlorocarbons, K. Grant Taylor
KWRRI Research Reports
The sodium hydride based reducing agents were prepared the method of Caubere (Angew. Chem. Int. Ed. Engl., 1983, 22, 599-613). Reagents were prepared containing nickel, iron and zinc metals. All were effective in dechlorinating 1,3-dichlorobenzene, 4-methoxy-chlorobenzene, and arochlor 1254. Most work focused on nickel based reagents, the most active. The nickel-based reducing agent used in THF at 65°C reduced to 200 ppm 1,3-dichlorobenzene (to benzene) and arochlor 1254 (to biphenyl) to below 0.2 ppm in less than 15 minutes. A two stage reduction reduced arochlor 1254 to below a detectable level as determined by gas chromatography using f.i.d. detector. Using …
Characterizing Soil Deformation By Direct Measurement Within The Profile, Randall K. Wood, Larry G. Wells
Characterizing Soil Deformation By Direct Measurement Within The Profile, Randall K. Wood, Larry G. Wells
Biosystems and Agricultural Engineering Faculty Publications
A unique feature of the University of Kentucky soil bin enables deformation to be characterized by studying a cross-sectional soil profile grid pattern. Modular sections of the bin are laterally removed to expose the cross-section after passes of a pneumatic tire.
The measured displacements of the grid points were converted to values of volumetric strain and then compared to soil density as measured by a dual probe gamma-ray density gauge following tests at various soil conditions. Final soil bulk density determinations using the two methods were not statistically different..
Fertilizer Use Changes In The U.S. And Kentucky, Monroe Rasnake, Dan Kirkland
Fertilizer Use Changes In The U.S. And Kentucky, Monroe Rasnake, Dan Kirkland
Soil Science News and Views
The use of inorganic fertilizers for crop production is perhaps the most successful educational program ever attempted by Land-Grant Colleges, the Tennessee Valley Authority and other agencies. Not many producers in the United States or the world will attempt to grow a crop without the use of fertilizers. In fact, some producers over fertilize and in recent years, the educational program has been aimed at teaching producers to limit fertilizer applications to what is actually needed based on soil tests and cropping conditions.
Fall Application Of Fertilizer, Kenneth L. Wells
Fall Application Of Fertilizer, Kenneth L. Wells
Soil Science News and Views
Fall application of fertilizer offers the advantages of (1) getting a job done which can delay early spring planting, (2) being able to get over fields when they are usually drier and less likely to compact, and (3) more often getting a price break from fertilizer dealers. Several crop-related advantages also apply and are discussed below. In terms of nutrients which can be fall applied, phosphate and potash are well adapted, Both these nutrients react strongly enough with soil to resist overwinter leaching. and the requirements for next year's production can safely be applied in the fall. Fall use of …
Specialty Vs. Farm Fertilizers For Turf, A. J. Powell Jr.
Specialty Vs. Farm Fertilizers For Turf, A. J. Powell Jr.
Soil Science News and Views
Professional golf course superintendents, lawn care supervisors and groundskeepers often spend 3-5 times more for a slow release, urea based, speciality fertilizer rather than urea or ammonium nitrate. Most speciality fertilizers contain 1/5 to 1/3 of its total N in insoluble or slow release form. This slow release nitrogen is included to Cll decrease the number of applications necessary (2) reduce burn potential (3) give uniform rather than a flush of growth and (4) increase N efficiency by reducing leaching and volatilization loss.
Considerations In No-Till Small Grain Production, David C. Ditsch, John H. Grove, Lloyd W. Murdock, James H. Herbek
Considerations In No-Till Small Grain Production, David C. Ditsch, John H. Grove, Lloyd W. Murdock, James H. Herbek
Soil Science News and Views
Small grains have become an important component of many crop rotations in Kentucky. Seedbed preparation has typically involved various degrees of tillage in which much of the residue from the previous crop is buried. Under such conditions, a field may be vulnerable to severe soil loss during periods of heavy rainfall until the plants have produced enough vegetative growth to cover the soil surface. Eliminating tillage in small grain production would not only reduce soil loss but also reduce labor cost and increase the timeliness of planting. Interest in no-till small grain production is growing. One survey reports that in …
Development Of General Guidelines For The Planning Of Stormwater Management Facilities: Application To Urban Watersheds In Kentucky, Lindell E. Ormsbee, Vincent T. Reinert
Development Of General Guidelines For The Planning Of Stormwater Management Facilities: Application To Urban Watersheds In Kentucky, Lindell E. Ormsbee, Vincent T. Reinert
KWRRI Research Reports
This report provides a planning methodology and a design tool to help determine the appropriate location and volume of detention basins required to control critical storm events. The technique involves using watershed characteristics including the SCS curve number, time of concentration, peak outflow rate, watershed area and the storage recurrence interval to help predict these detention volumes.
Historical rainfall records are used in a revised continuous simulation program (SYNOP, Hydroscience, Inc,) to determine the rainfall excess from which runoff hydrographs are produced. Various combinations of the watershed characteristics were input and computer analyses done to obtain the required data base. …
Investigation Of Pollution In A Karst Aquifer Utilizing Optical Brightener, John Thrailkill, Ralph F. Wiseman, Bridget R. Scanlon
Investigation Of Pollution In A Karst Aquifer Utilizing Optical Brightener, John Thrailkill, Ralph F. Wiseman, Bridget R. Scanlon
KWRRI Research Reports
Optical brightener is an additive to laundry detergents and is found contaminating groundwater. Its concentration may rapidly and inexpensively be determined by fluorescence techniques, and because its source is human wastewater, its presence in groundwater serves as a direct indication of pollution from septic tanks, sewer leaks, and landfills.
A total of 105 wells and springs in an area within the Inner Bluegrass Karst Region near Lexington, Kentucky, were described and sampled. Analyses were made for optical brightener (430 samples), total coliform (91), fecal coliform (93), and fecal streptococci (90). As many as 20 optical brightener and 4 bacterial samples …
Modeling Of Overland Flow By The Diffusion Wave Approach, Rao S. Govindaraju, S. E. Jones, M. L. Kavvas
Modeling Of Overland Flow By The Diffusion Wave Approach, Rao S. Govindaraju, S. E. Jones, M. L. Kavvas
KWRRI Research Reports
One of the major issues of present times, i.e. water quality degradation and a need for precise answers to transport of pollutants by overland flow, is addressed with special reference to the evaporator pits located adjacent to streams in the oil-producing regions of Eastern Kentucky. The practical shortcomings of the state-of-the-art kinematic wave are discussed and a new mathematical modeling-approach for overland flows using the more comprehensive diffusion wave is attempted as the first step in solving this problem. A Fourier series representation of the solution to the diffusion wave is adopted and found to perform well. The physically justified …
Micronutrients In Kentucky, William O. Thom
Micronutrients In Kentucky, William O. Thom
Soil Science News and Views
Micronutrients required for normal plant development and fruiting include boron, copper, iron, manganese, molybdenum, and zinc. Unlike the macronutrients (N, P, K, Ca, Mg and S), the quantities of micronutrients needed by agronomic crops is very small. Kentucky soils may contain large amounts of micronutrients in their mineral composition but only small amounts may be available for plant uptake. The soil availability and crop uptake of micronutrients are influenced by soil pH, soil temperatures, crop root growth, soil moisture, crop species and soil organic matter content.
Identification Of Soil-Water Chemical Parameters For The Prediction And Treatment Of Suspended Solids In Surface Water Reservoirs Of Coal Mine Lands, V. P. Evangelou, J. H. Grove, R. I. Barnhisel
Identification Of Soil-Water Chemical Parameters For The Prediction And Treatment Of Suspended Solids In Surface Water Reservoirs Of Coal Mine Lands, V. P. Evangelou, J. H. Grove, R. I. Barnhisel
KWRRI Research Reports
High concentrations of suspended solids in coal mine sedimentation ponds are a factor in lowering water quality. Colloidal particle settling simulations were carried out in the laboratory to test the influence pH and dissolved solids have on concentration and settling rates of suspended solids. The results of the study reveal that the pH range of colloidal coflocculation for the samples tested is between 3.5 and 4.5. Furthermore, liming simulation of acidic sediments, as expected increased colloid dispersion. This increase was dependent on the magnitude of the sodium adsorption ratio (SAR). The greater SAR systems maintained a greater concentration of colloidal …
After 15 Years Of No-Tillage Corn, Robert L. Blevins
After 15 Years Of No-Tillage Corn, Robert L. Blevins
Soil Science News and Views
Farmers shifting from a system of agricultural production that includes intensive tillage operations to a reduced or no-tillage system are often concerned about how this change may affect soil properties and productivity. No-tillage leaves the residues and fertilizers on the soil surface with no mechanical incorporation and may result in soil properties greatly different from plowed soils.
Effect Of Soil Additives On Water Infiltration On Kentucky Soils, Lloyd W. Murdock
Effect Of Soil Additives On Water Infiltration On Kentucky Soils, Lloyd W. Murdock
Soil Science News and Views
Many products are advertised and sold in Kentucky as soil additives to aid the movement of water into and through the soil. Most of these additives contain compounds that reduce the surface tension of water. That means that they change the way water is absorbed onto surfaces that have a tendency to repel water. However, their effectiveness in this regard has been questioned due to the huge volume of soil to be effected and the fact that our Kentucky soils are not hydrophobic. In order to determine the effectiveness of these types of products, an experiment was designed to test …
Efficient Use Of Fertilizer On Tobacco, J. L. Sims
Efficient Use Of Fertilizer On Tobacco, J. L. Sims
Soil Science News and Views
Recent increases in fertilizer prices and other productions costs have stimulated interest in ways to increase the efficiency of fertilizer use while maintaining or increasing yields and quality of tobacco. Growers currently spend about $250 per acre for fertilizer. Although this represents only 15 to 20 percent of the total cash costs per acre, it is one category of cash expenses that can be decreased.
Spring Nitrogen Management For Winter Wheat, John H. Grove
Spring Nitrogen Management For Winter Wheat, John H. Grove
Soil Science News and Views
Wheat producers commonly plan their nitrogen fertilizer management during winter months. The crop begins to break dormancy in many parts of the state in late February and early March and soon begins tillering and growing rapidly if nutrition is adequate. Nitrogen is the nutrient most often required and for which annual costs are the greatest for most wheat growers. Consideration of the following basic principles will help wheat producers improve the efficiency and effectiveness of their nitrogen fertilizer dollars.
Marketing Programs And Strategies, J. Kenneth Evans
Marketing Programs And Strategies, J. Kenneth Evans
Kentucky Alfalfa and Stored Forage Conference
Hay has never been widely perceived as a cash crop, therefore, it has historically accounted for a very small part of the total cash sales by farmers. It has been estimated that more than 90% of all hay baled in the state is retained on the producing farms. Most of that which is sold is transported very short distances and of course if one farmer in a community has a good hay year, all do. Organized marketing efforts have been minimal in both scope and successes. In 1978, efforts were initiated toward a more organized system of marketing Kentucky hay. …
The Economics Of Stand Life In The Production Of Alfalfa, W. Donald Shurley
The Economics Of Stand Life In The Production Of Alfalfa, W. Donald Shurley
Kentucky Alfalfa and Stored Forage Conference
Alfalfa is a crop which once established, can provide production of hay for several years thereafter. The productive years of the established crop are often referred to as the stand life. The life of an alfalfa stand is variable depending on many factors including variety grown, soil, weather conditions during the production period, insect and weed pressures, and of course the management skills of the producer in timely harvesting and other production jobs.
Alfalfa In Livestock Feeding Programs, Gary T. Lane
Alfalfa In Livestock Feeding Programs, Gary T. Lane
Kentucky Alfalfa and Stored Forage Conference
A magazine article entitled "Bidders Paid More For Quality at Wisconsin Hay Auction" caught my attention. Did they really pay more money for higher quality. I could not help but think of some hay sales which I have witnessed. One dollar per bale, large bales, small round bales, sixty dollars per ton, and $275 per ton are all some quotes I have heard recently in connection with hay purchases. Not much is said about quality. We may hear relative terms such as good, not much grass, cut early, not rained on or others but not much about nutrient content or …
Grazing Alfalfa, Charles T. Dougherty
Grazing Alfalfa, Charles T. Dougherty
Kentucky Alfalfa and Stored Forage Conference
Alfalfa (Medicaao sativa) is a native of an area south of the Black and Caspian seas and it still grows wild in Iran and eastern Anatolia. Alfalfa was the chosen forage for the fighting horses of ancient armies as long ago as 1800 B.C. when the Kassites conquered Babylon. The spread of alfalfa followed the pathway of armies through the Mediterranean, Europe, and the New World. For ages before man used alfalfa to fuel his fighting animals natural selection processes worked on the evolution of alfalfa and its predecessors. A scenario which would account for the morphology and …
Chemical Preservation Of Alfalfa Hay, Dan O. Riddell
Chemical Preservation Of Alfalfa Hay, Dan O. Riddell
Kentucky Alfalfa and Stored Forage Conference
Kentucky farmers harvest about 3 million tons of hay annually. In order to minimize dry matter losses and quality deterioration, hay should be baled with about 20% moisture. Unfortunately, adequate time required to field-dry hay to 20% moisture is often not available due to weather conditions. This is especially true for the first cutting of alfalfa in the spring. Many farmers are forced to choose between letting cut hay get rained on or baling hay wetter than is recommended. Hay baled with more than 20-25% moisture generally becomes moldy and undergoes a heating process which makes part of the protein …
Biological Control Of Alfalfa Insect Pests, Chris M. Christensen
Biological Control Of Alfalfa Insect Pests, Chris M. Christensen
Kentucky Alfalfa and Stored Forage Conference
Alfalfa is a succulent plant that obviously is good feed for large herbivores such as cattle and horses. Therefore, it should not be surprising that a large number of small herbivores such as insects also find this plant delicious. Fortunately, most of these insects are not major pests. However, we do have a couple pest insects that annually attack this valuable crop and often cause economic damage.
Controlling insect pests is expensive and time consuming. However, not controlling them can be disastrous to the profit margin of the alfalfa producer. Entomologists who work on the insect pests of alfalfa have …
Weed Control In Alfalfa — Present & Future, Charles H. Slack
Weed Control In Alfalfa — Present & Future, Charles H. Slack
Kentucky Alfalfa and Stored Forage Conference
To achieve maximum alfalfa production and maintain excellent stands and forage quality for a number of years, producers need to start including weed control in their management program. Unfortunately good stands are not being established because of early weed competition where herbicides are not used. Alfalfa stands tend to play out before achieving their maximum number of years of production unless maintenance herbicides are used. Fortunately there are now herbicides registered to meet most every phase of alfalfa production.
This paper will deal primarily with the herbicides that are currently labeled for use on alfalfa. Several herbicides that are not …
Fertilizing Alfalfa For Optimum Production, Lloyd W. Murdock
Fertilizing Alfalfa For Optimum Production, Lloyd W. Murdock
Kentucky Alfalfa and Stored Forage Conference
Alfalfa is a high producing crop. Therefore, it only makes sense not to limit its production or longevity by establishing it on unsuitable soil and by the use of unsound fertility practices. It is the aim of this paper to propose practices which will not limit the production of alfalfa, but, also allow it to be done as efficiently as possible with only the necessary inputs.
No-Till Alfalfa — Research And Observations, Garry D. Lacefield
No-Till Alfalfa — Research And Observations, Garry D. Lacefield
Kentucky Alfalfa and Stored Forage Conference
In previous addresses to this Conference, I have suggested four basic goals be included in your alfalfa program: 1) attention to details prior to and during establishment such that you establish a thick, weed-free stand; necessary management to; 2) keep the stand productive for five years; 3) produce five tons per acre per year, and; 4) market your harvest product either as a cash crop or through your livestock program for profit. In the presentations to follow today, information will be presented which, if adapted to your program, will permit you to reach and surpass the above goals.
The topic …
Kentucky's Soils Potential For Alfalfa Production, Kenneth L. Wells
Kentucky's Soils Potential For Alfalfa Production, Kenneth L. Wells
Kentucky Alfalfa and Stored Forage Conference
A description of Kentucky's land base indicates that of nearly 15 million acres suitable for cropland usage, approximately three-fourths has an erosion hazard potential of some degree, relating largely to steepness of slope (1). For this reason, there is a large potential acreage of alfalfa and other perennial forage crops relating to their sod forming growth habit which provides them an inherent value in erosion control.
Foreword [1985], Garry D. Lacefield
Foreword [1985], Garry D. Lacefield
Kentucky Alfalfa and Stored Forage Conference
This is the front matter of the proceedings.
The Hydrogen Line Spectra Of Narrow-Line Radio Galaxies, Gary J. Ferland, Donald E. Osterbrock
The Hydrogen Line Spectra Of Narrow-Line Radio Galaxies, Gary J. Ferland, Donald E. Osterbrock
Physics and Astronomy Faculty Publications
We report the results of the first detection of Lyα in a narrow-line radio galaxy. Nearly simultaneous optical and UV observations of 3C 192 and 3C 223 allow the measurement of both Balmer and Lyman decrements. These line ratios are approximate functions of the interstellar reddening and of a parameter which is proportional to the amount of H I collisional excitation present. The reddening of 3C 192 is slightly larger than that due to our Galaxy, although 3C 223 may have a larger value. Both galaxies have intrinsic Balmer and Lyman decrements which are significantly steeper than case B, …