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2004

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Articles 2281 - 2310 of 4447

Full-Text Articles in Physical Sciences and Mathematics

Substrates Made By Electrodeposition For Measuring Electrical Properties Of One Dimensional Nanomaterials, Jin-Xuan Liu, Juan Xiang, Zhong-Qun Tian, Bing-Wei Xiamen University Mao, Xiamen Xiamen, China China Feb 2004

Substrates Made By Electrodeposition For Measuring Electrical Properties Of One Dimensional Nanomaterials, Jin-Xuan Liu, Juan Xiang, Zhong-Qun Tian, Bing-Wei Xiamen University Mao, Xiamen Xiamen, China China

Journal of Electrochemistry

A method to prepare alternating conducting/insulating substrates by electrodeposition-oxidation was established to facilitate I-E measurements of one-dimensional nanomaterial by CT-AFM. The prepared Au/CuO and HOPG/CuO substrates showed low roughness as well as high uniformity of the alternating conducting/insulating structure, Qualitative I-E measurements were performed on a single carbon nanotube attached to the two above-mentioned substrates, both showing metallic characteristics at room temperature and in air.

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Study On The Electrochemical Impedance Spectroscopy (Eis) Of Al-Bronze At Different Anodic Potentials, Hui Yu, Sa-Ying Dong, Hai-Bo Xu, Ming-Xian Sun Feb 2004

Study On The Electrochemical Impedance Spectroscopy (Eis) Of Al-Bronze At Different Anodic Potentials, Hui Yu, Sa-Ying Dong, Hai-Bo Xu, Ming-Xian Sun

Journal of Electrochemistry

The corrosion dissolution mechanism of Al-bronze has been investigated by Electrochemical Impedance Spectroscopy (EIS) at different anodic potentials. In the active region, the corrosion products are complex compounds of cupreous chloride and the diffusion of CuCl~(-)_2 is the control process of electrochemical reaction. In the transition region, there exhibits two capacitance loops on EIS because CuCl and cupreous oxides films deposit on the electrode surface. In the limiting current region, an inductance loop appears on the EIS because the breakdown of the oxides film leads to serious pit corrosion.

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Studies On The Mechanism Of Electroreduction Of Oxalic Acid, Yu Zhan Li, Xin Liu, Rui Sheng Hu, Deng Ping Gu Feb 2004

Studies On The Mechanism Of Electroreduction Of Oxalic Acid, Yu Zhan Li, Xin Liu, Rui Sheng Hu, Deng Ping Gu

Journal of Electrochemistry

The electroreduction mechanism of oxalic acid on Pb electrode in Na_2SO_4 solution were investigated using high scan rate cyclic voltammetry and chronoamperometry. The dynamic parameters for the first step electron transter reaction of oxalic acid electroreduction by were determined. The corresponding reduction peak potentials of oxalic acid, glyoxylic acid and glycolic acid in the cyclic voltammogranis obtained in the same condition were compared, and the intermediate reduction products of oxalic acid were suggested. The results showed that oxalic acid is weakly absorbed on the lead electrode.

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Preparation, Structure And Electrochemical Hydrogenation Of Carbon Nanotubes Supported Platinum Catalysts, Qing-Gang He, Xiao-Zi Yuan, Xian-Xia Yuan, Zi-Feng Ma Feb 2004

Preparation, Structure And Electrochemical Hydrogenation Of Carbon Nanotubes Supported Platinum Catalysts, Qing-Gang He, Xiao-Zi Yuan, Xian-Xia Yuan, Zi-Feng Ma

Journal of Electrochemistry

In this paper, Pt/CNTs catalyst was prepared and its electrocatalytic property was studied by obtaining cycling voltammetry curves (C-V) and Tafel curves. In addition, the XRD,XPS and TEM tests were carried out to determine the structure and composition of the catalysts. It can be found that the platinum loading has been increased significantly using a carbon nanotubes support. Dispersion of Platinum was better and gave more active sites. The electrochemical characteristic of Pt/CNTs was also more desirable than that of Pt/C catalyst(Johnson Matthey). In conclusion, carbon nanotubes can played a conspicuous role in "electrogenerative" processes of PEMFC hydrogenation reactor.

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Study On Determination Of Iodine Ion At Chitosan Modified Glassy Carbon Electrode, Bin Liu, Xiang-Ying Sun, Jin-Rui Xu Feb 2004

Study On Determination Of Iodine Ion At Chitosan Modified Glassy Carbon Electrode, Bin Liu, Xiang-Ying Sun, Jin-Rui Xu

Journal of Electrochemistry

In this paper, a chitosan modified glassy carbon electrode was prepared by the method of covalent-bond reaction, and the anodic stripping voltammetric characteristics of iodine on the modified electrode was studied. The results showed that the modified electrode has higher adsorption and selectivity for I~-, and the sensitivity for I~- has been much improved in 0.1 mol·L~(-1) KH_2PO_4 solution (pH=4.0). The anodic stripping peak current of I~- on the modified electrode varied linearly with I~- concentration in the range of 2.0×10~(-6)～2.0×10~(-3) mol·L~(-1), and the detection limit reached 2.0×10~(-7) mol·L~(-1).

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Electrochemical Investigation Of The Dynamic Process For The Solid Supported Bilayer Lipid Membrane, Zhao Yan, Fang Yan Feb 2004

Electrochemical Investigation Of The Dynamic Process For The Solid Supported Bilayer Lipid Membrane, Zhao Yan, Fang Yan

Journal of Electrochemistry

Three electrochemical methods,cyclic voltammetry, chronoamperometry and open-circuit potential had been used to study the dynamic process of the ITO (indium-tin oxide) conducting glass supported BLM (ITO/s-BLM) system.The results showed that the self-organization process of the membrane could be simply,visually and feasibly reflected by the three methods. Furthermore, the membrane voltage of the ITO/s-BLM system was about 0.1V when measured by open-circuit potential.

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Study Of Electrochemical Properties Of The Hydride Alloy Electrode Zrcr_(0.4)Mn_(0.2)V_(0.1)Co_(0.1)Ni_(1.2) At High Temperature, Song Li, Shi-Jun Ji, Jun-Cai Sun Feb 2004

Study Of Electrochemical Properties Of The Hydride Alloy Electrode Zrcr_(0.4)Mn_(0.2)V_(0.1)Co_(0.1)Ni_(1.2) At High Temperature, Song Li, Shi-Jun Ji, Jun-Cai Sun

Journal of Electrochemistry

Electrochemical properties of the hydride alloy electrode ZrCr_(0.4)Mn_(0.2)V_(0.1)Co_(0.1)Ni_(1.2) at the different temperature have been investigated. The results showed that the alloy electrodes possessed the maximum discharge capacities 336 mAh/g and 298 mAh/g at 25 ℃ and 70 ℃ respectively. The activation process of the alloy at 70 ℃ became faster, and the alloy reached its maximum capacity in less than 4 cycles, while in 13 cycles at 25 ℃. The high rate capability increased from 55 % at 25 ℃ to 71% at 70 ℃ at 300 mA/g. It was worth noting that the alloys at 25 ℃ and 70 …

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Effect Of Thiourea On Nickel Deposition, Guang-Hui Hu, Hui-Huang Wu, Fang-Zu Yang, Sheng-Lin Ical Chemistry Of Solid Surfaces Wang, University Xiamen, Xiamen Xiamen, China China Feb 2004

Effect Of Thiourea On Nickel Deposition, Guang-Hui Hu, Hui-Huang Wu, Fang-Zu Yang, Sheng-Lin Ical Chemistry Of Solid Surfaces Wang, University Xiamen, Xiamen Xiamen, China China

Journal of Electrochemistry

Effect of thiourea on nickel deposition at glassy carbon and nickel-deposited glass carbon electrodes was investigated with cyclic voltammograms and impetance-potential curves. It was found that the nucleation processes occurred at the glassy carbon electrode. However, this characteristics disappeared at the nicked-deposited glassy carbon electrode. It was suggested that the presence of thiourea hindered the nucleation processes, yet accelerated grain growth.Curves of impetance-potential could sensitively detect effect of thiourea on nickel depositon and reflect changes in rate-determining step with potential.

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Electrodeposition Nanolaminated Growth Of Zinc, Ying Cao, Tian-Hui Shen, Jing-Yuan Yao, Gui-Fu Ding Feb 2004

Electrodeposition Nanolaminated Growth Of Zinc, Ying Cao, Tian-Hui Shen, Jing-Yuan Yao, Gui-Fu Ding

Journal of Electrochemistry

Nanolaminated growth of the electrodeposition of zinc was studied. The structure and size of crystalline in zinc coatings were investigated by using FEG-TEM and XRD. The corrosion tests of the zinc deposition and the Coatings-Neutral salt spray test were performed, the capability in corrosion resistance of the nanolaminated growth was better than that of others.

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An Orthogonal Scaling Vector Generating A Space Of $C^1$ Cubic Splines Using Macroelements, Bruce Kessler Feb 2004

An Orthogonal Scaling Vector Generating A Space Of $C^1$ Cubic Splines Using Macroelements, Bruce Kessler

Mathematics Faculty Publications

The main result of this paper is the creation of an orthogonal scaling vector of four differentiable functions, two supported on $[-1,1]$ and two supported on $[0,1]$, that generates a space containing the classical spline space $\s_{3}^{1}(\Z)$ of piecewise cubic polynomials on integer knots with one derivative at each knot. The author uses a macroelement approach to the construction, using differentiable fractal function elements defined on $[0,1]$ to construct the scaling vector. An application of this new basis in an image compression example is provided.

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Progress In Research For Biofuel Cell, Yue Bao, Xia-Qin Wu Feb 2004

Progress In Research For Biofuel Cell, Yue Bao, Xia-Qin Wu

Journal of Electrochemistry

In this article, research progresses of the biofuel cell in recent years were summarized. The operation principle and classification of the biofuel cells were described. The role of the mediator for promoting electron transfer in biofuel cells and the techniques for improving the electric properties of biofuel cells, such as output potential, were discussed with some attracting research instances. Finally, the choke points for research of biofuel cell were explored, and the application prospect of biofuel cells was forecasted.

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Formation And Characterization Of Water-Repellent Nano Tio_2 Coating And Studying Its Anticorrosion Property, Guang-Xia Shen, Yi-Cong Chen, Chang-Jian Lin Feb 2004

Formation And Characterization Of Water-Repellent Nano Tio_2 Coating And Studying Its Anticorrosion Property, Guang-Xia Shen, Yi-Cong Chen, Chang-Jian Lin

Journal of Electrochemistry

Using ethyl acetoacetate (EAcAc) as a chelating agent, ultra fine TiO_2 sol is prepared. Nano-TiO_2 coatings are deposited on the 316L stainless steel by the dip-coating. Hydrothermal post-treatment leads to crack-free coatings. Meanwhile, the surface struture and properties was optimized. Self-assembly of Hetadecafluorodecyltrimethoxysilane (FSA-13) fabricates hydrophobic layers on the surface of the nano-TiO_2 coatings. Particle sizes of TiO_2 sol was analysed by zeta pals potential analysis, and surface morphology, structure and properties was characterized by contract angle instrument, XRD, and SEM technologies. The results have shown that the surface of coatings is porous, with approx. 375 nm thick, the particle …

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Electrochemical Study On The Anodic Process Of Fes, Hong-Hui Xu Feb 2004

Electrochemical Study On The Anodic Process Of Fes, Hong-Hui Xu

Journal of Electrochemistry

Ferrous sulfide (FeS) was synthesized with spectrum-pure Fe and S at high-temperature, and its anodic behaviors in the solution of 0.5 mol·L~(-1) H_2SO_4 + 0.5 mol·L~(-1) K_2SO_4 was studied by using voltage sweep and step voltage techniques. The effects of acidity on the anodic polarization curves of FeS were investigated. The transfer coefficient β and exchange current density I_0 in the anodic electrode process, and the solid diffusion coefficient D_(Fe) of Fe~(2+) in FeS were measured. And also the activation energies of anodic reaction at different voltages was also determined.

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Electrochemical Synthesis Of Ferrate(Vi) By Anodic Oxidation, Jia-Ju Xu, Jian-Ming Wang, Wei-Hua Yang, Cheng Chen, Jian-Qing Zhang Feb 2004

Electrochemical Synthesis Of Ferrate(Vi) By Anodic Oxidation, Jia-Ju Xu, Jian-Ming Wang, Wei-Hua Yang, Cheng Chen, Jian-Qing Zhang

Journal of Electrochemistry

The ferrate(Ⅵ) was synthesized by electrochemical anodic oxidation. The effects of preparation conditions on the current yield of ferrate(VI) synthesis have been studied in this work. The experimental results showed that grey cast iron as an anodic material is suitable for electrochemical synthesis and NaOH solution as an electrolyte results in a higher current yield than KOH solution. The highest current yield was obtained at a current density (4.54) mA· cm~(-2),temperature 20　℃ and 14 mol·dm~(-3) NaOH. In this case, a current yield of 68.5% was obtained by electrolysis for 1 h.

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Electrochemical Character Of Water Containing Gel Electrolyte And Its Preliminary Examination In Lithium Water Cell, Jing-Dong Liu, Wen-Ji Wang, Xin-Zheng Yi Feb 2004

Electrochemical Character Of Water Containing Gel Electrolyte And Its Preliminary Examination In Lithium Water Cell, Jing-Dong Liu, Wen-Ji Wang, Xin-Zheng Yi

Journal of Electrochemistry

AC impedance technique has been used to characterize the system of poly(methyl acrylic acid )-poly(methyl acrylic lithiumate )-glycerol (referred to as GPE ) .The results showed that the conductivity of GPE increased with increasing both temperature and its water content .The glass transition temperature of GPE polymer could be lowered by water .Its conducting characteristic was just like liquid electrolyte ,The electrolysis of GPE was almost the same as the electrolysis of water .Its composition voltage was about 1.50V .The GPE has been used to manufacture lithium water cell. When the graphite was used as cathode, the cell could discharge …

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Study Of Sptfs/Ptfe Composite Membranes With Different Ews, Yong-Zhu Fu, Dan-Min Xing, Bao-Lian Yi, Hua-Min Zhang Feb 2004

Study Of Sptfs/Ptfe Composite Membranes With Different Ews, Yong-Zhu Fu, Dan-Min Xing, Bao-Lian Yi, Hua-Min Zhang

Journal of Electrochemistry

In this paper, sPTFS/PTFE composite membranes for PEMFC were obtained by impregnating two kinds of sulfonated poly-α,β,β- trifluorostyrene resin with different EWs into the porous PTFE substrate membranes. Water uptake, proton conductivity, mechanical strength and fuel cell performance of these two composite membranes were measured. Water uptake and proton conductivity were greatly reduced and mechanical strength was increased by composition in comparison with homogeneous membranes. Under the operating condition: T_(Cell)=80 ℃, P_(H_2)=0.2　MPa,P_(O_2)=0.2　MPa, fuel cell performance of the two composite membranes were better than that of Nafion~115. The fuel cell performance of composite membrane with low EW was better …

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The Interaction In Doping Lithium Of Carbonaneous Anode In Lithium Ion Battery, Chang-Guo Chen, Hong-Min Zhang, Jia Chen, Dan-Mei Yu Feb 2004

The Interaction In Doping Lithium Of Carbonaneous Anode In Lithium Ion Battery, Chang-Guo Chen, Hong-Min Zhang, Jia Chen, Dan-Mei Yu

Journal of Electrochemistry

The quantum chemical DV-X_α method was used to calculate the lithium-doped models from one-Li-dopant to LiC_6 and LiC_2. It was found that Li~+ has an tendency to attract electrons from the carbon plane through the C_6 hexagons lying above or below it by the graph of charge-density difference. It was shown that LiC_6 can exist steadily,while LiC_2 can not exist steadily.

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Coulometric-Weighing Test Method And Its Application In Determination Of Tin Coating Mass For Electrolytic Tinplate, Xiu-Wen Dong Feb 2004

Coulometric-Weighing Test Method And Its Application In Determination Of Tin Coating Mass For Electrolytic Tinplate, Xiu-Wen Dong

Journal of Electrochemistry

The coulometric-weighing test method was established and applied to determine the tin coating mass for electrolytic timplate. The effects of electric quantity, the current efficiency and the electrochemical equivalent in the coulometric test method were overcome. the inaccuracy in the determination of final point at the anodic dissolution curve in the weighing method was avoided when applied to the electrolytic timplate, higher accuracy was obtained, the SD is less than 0.04 g/m~2,RSD is as small as 0.36%.

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Photos Of The 24th Kentucky Alfalfa Conference Award Winners, Kentucky Alfalfa Conference Feb 2004

Photos Of The 24th Kentucky Alfalfa Conference Award Winners, Kentucky Alfalfa Conference

Kentucky Alfalfa and Stored Forage Conference

No abstract provided.

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Moisture--Temperature Management During Alfalfa Hay And Silage Making & Storing, Michael Collins Feb 2004

Moisture--Temperature Management During Alfalfa Hay And Silage Making & Storing, Michael Collins

Kentucky Alfalfa and Stored Forage Conference

In some areas of the country, producers store a substantial portion of their forage for winter feeding as silage or haylage. However, hay remains the most popular storage method for forage. Hay stores well for long periods and is better suited to cash sale and transportation than silage. Mechanical conditioning, which gained acceptance during the 1950's is probably still the greatest single change in hay harvesting and storage technology during this century. However, a number of other noteworthy changes and innovations have occurred in recent years which have helped to reduce the extent of losses during hay harvesting and storage.

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Marketing Kentucky Alfalfa, Nicky Baker Feb 2004

Marketing Kentucky Alfalfa, Nicky Baker

Kentucky Alfalfa and Stored Forage Conference

The main key to marketing hay over the years is flexibility. Don’t gear up too heavy for the one specific market. Keep your options open and remember there aren’t any government payments.

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Marketing Kentucky Alfalfa, Tom Keene Feb 2004

Marketing Kentucky Alfalfa, Tom Keene

Kentucky Alfalfa and Stored Forage Conference

In order to market Kentucky produced alfalfa, we need to go back and look at our operation to see if we can produce high quality alfalfa. We can start doing this by determining what the best land use is given the particular soils and typography that makes up your farm layout. There are other things we need to be aware of after we determine our ability to grow alfalfa; is the terrain suitable for harvesting alfalfa using different types of harvesting equipment? Also do we have the equipment necessary to produce alfalfa, either as a grazing tool, grass hay or …

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Balancing Agronomics And Economics Of Alfalfa Hay Production, Brian Lacefield, Garry D. Lacefield Feb 2004

Balancing Agronomics And Economics Of Alfalfa Hay Production, Brian Lacefield, Garry D. Lacefield

Kentucky Alfalfa and Stored Forage Conference

Alfalfa has high-yielding, high-quality, persistent, and profitable potential if given adequate management and a balance of several agronomic and economic considerations. How can we account for the differences among producers who have the average alfalfa yields of 3.0 tons/A with the top hay producers who average approximately 5.0 tons/acre and the producer who has achieved the record yield of 10.13 tons/acre? Is the answer “luck”, better soils, moisture and growing conditions? The answer may certainly be yes, but. Yes, the factors above are important and can explain some differences; however, we believe the overall difference is the management of research-based …

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Hybrid Alfalfa: Reality Or Pipe Dream? Dairyland Seed Company, Michael Velde Feb 2004

Hybrid Alfalfa: Reality Or Pipe Dream? Dairyland Seed Company, Michael Velde

Kentucky Alfalfa and Stored Forage Conference

Progress in increasing alfalfa forage yield has been minimal over the past 20 years. This is due primarily to lack of pollen control in open pollinated synthetic varieties. All alfalfa varieties to date have been open pollinated synthetic varieties. New alfalfa hybridization technology provides the tools to overcome the forage yield barriers that have been hindering alfalfa breeders from making progress

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Roundup Ready Alfalfa Update, Daniel O. Foor Feb 2004

Roundup Ready Alfalfa Update, Daniel O. Foor

Kentucky Alfalfa and Stored Forage Conference

No abstract provided.

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Establishing Alfalfa Using No-Till Techniques, Gary Bates Feb 2004

Establishing Alfalfa Using No-Till Techniques, Gary Bates

Kentucky Alfalfa and Stored Forage Conference

There have been many changes in agriculture over the last 50 years. One of the greatest has been the use of no-till planting methods. The development of drill and herbicides has made no-till seedings as successful as seeding into prepared land.

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Measuring Hay Temperatures, Doug Overhults Feb 2004

Measuring Hay Temperatures, Doug Overhults

Kentucky Alfalfa and Stored Forage Conference

It is well known that baling hay at the right moisture content is the key to preventing excessive heating in the bale. It can be quite a challenge, though, to get all of the hay baled without some of it being a bit wetter than is desirable. That’s when trouble can begin, and we have to be concerned about heating that could damage the hay or even lead to spontaneous combustion. Fortunately, the heating process does take some time to develop and we do know what temperatures signal that a critical situation may be developing. So, monitoring bale or stack …

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Fertilizing Alfalfa For Profit, Monroe Rasnake Feb 2004

Fertilizing Alfalfa For Profit, Monroe Rasnake

Kentucky Alfalfa and Stored Forage Conference

Alfalfa has a high yield potential in relation to most other forages. However, this potential can only be realized on a long-term basis if the nutrient needs of the plant are adequately provided for. In addition, the ability of alfalfa plants to survive the heat and drought of summer and the cold of winter depends on an abundant supply of plant nutrients.

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Grazing Alfalfa, Garry D. Lacefield Feb 2004

Grazing Alfalfa, Garry D. Lacefield

Kentucky Alfalfa and Stored Forage Conference

Over the past decade we have had several people address “Alfalfa as a Grazing Crop” including Warren Thompson, Gary Bates, Ken Johnson, Jason Sandefur, Byron Sleugh, and myself. Each has done an excellent job discussing the merits of this remarkable crop and the opportunities it offers for grazing. At the end of the Conference last year, I (as I always do) asked for your suggestions concerning topics for this years’ conference. As it has been for the past decade, “Grazing” was the most requested topic. In today’s presentation, let’s go back and revisit the question, “Is Grazing Alfalfa Right for …

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Foreword And Recipients Of Kentucky Alfalfa Awards [2004], Garry D. Lacefield, Christi L. Forsythe Feb 2004

Foreword And Recipients Of Kentucky Alfalfa Awards [2004], Garry D. Lacefield, Christi L. Forsythe

Kentucky Alfalfa and Stored Forage Conference

No abstract provided.

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