17,511 research outputs found
Arkansas Wheat Cultivar Performance Tests 2016-2017
Wheat cultivar performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agricultureâs Arkansas Agricultural Experiment Station, Department of Crop, Soil and Environmental Sciences. The tests provide information to companies developing cultivars and marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for small-grain producers
Arkansas Wheat Cultivar Performance Tests 2018-2019
Wheat cultivar performance tests are conducted each year in Ark- ansas by the University of Arkansas System Division of Agricultureâs Arkansas Agricultural Experiment Station, Department of Crop, Soil and Environmental Sciences. The tests provide information to companies developing cultivars and marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for small-grain producers. The tests are conducted at the Northeast Research and Extension Center at Keiser, the Vegetable Substation near Kibler, the Lon Mann Cotton Research Station near Marianna, the Newport Extension Center near Newport, the Rohwer Research Station near Rohwer, the Pine Tree Research Station near Colt, and the Hope Research and Extension Center. In addition, entries are evaluated in a stripe rust (Puccinia striiformis f.sp. tritici) inoculated nursery in Fayetteville and a Fusarium head blight (FHB) inoculated nursery in Newport and Fayetteville. Specific location and cultural practice information accompany each table
Quantum Hall Ferromagnets: Induced Topological term and electromagnetic interactions
The quantum Hall ground state in materials like GaAs is well known
to be ferromagnetic in nature. The exchange part of the Coulomb interaction
provides the necessary attractive force to align the electron spins
spontaneously. The gapless Goldstone modes are the angular deviations of the
magnetisation vector from its fixed ground state orientation. Furthermore, the
system is known to support electrically charged spin skyrmion configurations.
It has been claimed in the literature that these skyrmions are fermionic owing
to an induced topological Hopf term in the effective action governing the
Goldstone modes. However, objections have been raised against the method by
which this term has been obtained from the microscopics of the system. In this
article, we use the technique of the derivative expansion to derive, in an
unambiguous manner, the effective action of the angular degrees of freedom,
including the Hopf term. Furthermore, we have coupled perturbative
electromagnetic fields to the microscopic fermionic system in order to study
their effect on the spin excitations. We have obtained an elegant expression
for the electromagnetic coupling of the angular variables describing these spin
excitations.Comment: 23 pages, Plain TeX, no figure
Three very young HgMn stars in the Orion OB1 Association
We report the detection of three mercury-manganese stars in the Orion OB1
association. HD 37886 and BD-0 984 are in the approximately 1.7 million year
old Orion OB1b. HD 37492 is in the approximately 4.6 million year old Orion
OB1c. Orion OB1b is now the youngest cluster with known HgMn star members. This
places an observational upper limit on the time scale needed to produce the
chemical peculiarities seen in mercury-manganese stars, which should help in
the search for the cause or causes of the peculiar abundances in HgMn and other
chemically peculiar upper main sequence stars.Comment: 8 pages including 1 figure. To appear in Astrophysical Journal
Letter
Remote participation during glycosylation reactions of galactose building blocks: Direct evidence from cryogenic vibrational spectroscopy
The stereoselective formation of 1,2âcisâglycosidic bonds is challenging. However, 1,2âcisâselectivity can be induced by remote participation of C4 or C6 ester groups. Reactions involving remote participation are believed to proceed via a key ionic intermediate, the glycosyl cation. Although mechanistic pathways were postulated many years ago, the structure of the reaction intermediates remained elusive owing to their shortâlived nature. Herein, we unravel the structure of glycosyl cations involved in remote participation reactions via cryogenic vibrational spectroscopy and first principles theory. Acetyl groups at C4 ensure αâselective galactosylations by forming a covalent bond to the anomeric carbon in dioxoleniumâtype ions. Unexpectedly, also benzyl ether protecting groups can engage in remote participation and promote the stereoselective formation of 1,2âcisâglycosidic bonds
Thermodynamic Phase Diagram of the Quantum Hall Skyrmion System
We numerically study the interacting quantum Hall skyrmion system based on
the Chern-Simons action. By noticing that the action is invariant under global
spin rotations in the spin space with respect to the magnetic field direction,
we obtain the low-energy effective action for a many skyrmion system.
Performing extensive molecular dynamics simulations, we establish the
thermodynamic phase diagram for a many skyrmion system.Comment: 4 pages, RevTex, 2 postscript figure
Arkansas Wheat Cultivar Performance Tests 2015-2016
Wheat cultivar performance tests are conducted each year in Arkansas by the Arkansas Agricultural Experiment Station, Department of Crop, Soil and Environmental Sciences. The tests provide information to companies developing cultivars and/or marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for small-grain producers
Arkansas Wheat Cultivar Performance Tests 2017-2018
Wheat cultivar performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agricultureâs Arkansas Agricultural Experiment Station, Department of Crop, Soil and Environmental Sciences. The tests provide information to companies developing cultivars and marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for small-grain producers
Arkansas Wheat Cultivar Performance Tests 2014-2015
Wheat cultivar performance tests are conducted each year in Arkansas by the Arkansas Agricultural Experiment Station, Department of Crop, Soil and Environmental Sciences. The tests provide information to companies developing cultivars and/or marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for small-grain producers
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