2,059 research outputs found

    Plasma operation with high-Z environment

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    Isotopic Composition of the Solar Wind Inferred from In-Situ Spacecraft Measurements

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    The Sun is the largest reservoir of matter in the solar system, which formed 4.6Gyr ago from the protosolar nebula. Data from space missions and theoretical models indicate that the solar wind carries a nearly unfractionated sample of heavy isotopes at energies of about 1keV/amu from the Sun into interplanetary space. In anticipation of results from the Genesis mission's solar-wind implanted samples, we revisit solar wind isotopic abundance data from the high-resolution CELIAS/MTOF spectrometer on board SOHO. In particular, we evaluate the isotopic abundance ratios 15N/14N, 17O/16O, and 18O/16O in the solar wind, which are reference values for isotopic fractionation processes during the formation of terrestrial planets as well as for the Galactic chemical evolution. We also give isotopic abundance ratios for He, Ne, Ar, Mg, Si, Ca, and Fe measured in situ in the solar win

    Comparing Yield and Quality of Milk from Dairy Cows Fed Stockpiled Annual Ryegrass (\u3cem\u3eLolium Multiflorum\u3c/em\u3e L.) and Cereal Rye (\u3cem\u3eSecale Cereale\u3c/em\u3e L.)

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    Stockpiling annual ryegrass and cereal rye provides a low cost substitute to hay and creates an excellent source of feed during winter (Kallenbach et al., 2003). In addition to lowering feed costs, grazing increases the conjugated linoleic acid (CLA) content of milk compared to feeding hay. Previous research suggested that forage species might differ in their ability to alter milk CLA content during the growing season (Wu et al., 1997). However, research is needed to determine if different forage species used for winter and early spring grazing impacts the CLA content of milk. The objective of this experiment was to compare yield and quality of milk when cows graze annual ryegrass or cereal rye in late winter and early spring

    Overseeding Cereal Rye and Annual Ryegrass Into Soyabean for Forage as Part of a Multifunctional Cropping System

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    In the lower Midwest, the longest period of inadequate forage supply from pasture is from mid- December through mid-March (Matches & Burns, 1995). Livestock producers in this region are looking for high quality forage for winter grazing (Kallenbach et al., 2003). Annual ryegrass (Lolium multiflorum Lam.) and cereal rye (Secale cereale L.) are two forages that Missouri\u27s beef producers are interested in to extend the grazing season. The objective of this research was to determine how seeding date impacts the establishment, growth, and forage production of annual ryegrass and cereal rye when planted into soyabean fields as part of a multifunctional cropping system

    New Methods for Depositing and Imaging Molecules in Scanning Tunneling Microscopy

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    Methods and apparatus are described to deposit and image molecules by scanning tunneling microscopy (STM) under an inert atmosphere. Three methods of applying molecules have been evaluated: equilibrium adsorption from the vapor phase, sublimation, and electrospraying. Using these methods, a variety of organic and biopolymer molecules have been deposited and imaged on graphite and on gold (111), grown epitaxially on mica. Compared with alternatives, such as the use of high vacuum apparatus or glove boxes, these procedures offer some important advantages: they are inexpensive, convenient, and more rapid. Mercaptoethanol, ethanolamine, ethanol, acetic acid, and water produce two-dimensional crystalline adlayers on gold substrates, when they are introduced into the scanning cell as vapors. These adlayers are assumed to involve hydrogen bonding of the molecules to an oxide of gold formed on the surface. Electrospraying protein solutions on gold surfaces yielded images of individual protein molecules with lateral dimensions close to those measured by X-ray analysis, and thicknesses of 0.6-1.3 nm. In the case of metallothionein, the known internal domain structure of the molecule was reproducibly observed. No detailed internal structure could be resolved in the other examples examined
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