388 research outputs found
Corn Performance Tests, 1946
Corn performance tests are conducted each year by the Agronomy Department of the South Dakota Agricultural Experiment Station to supply to those interested in corn impartial information on the yielding ability, maturity requirements and other characteristics of hybrids and open-pollinated varieties. It would be impractical to attempt to test all of the several hundred commercial hybrids sold in the state or try to locate tests in each of the various districts into which the state might be divided on the basis of soil type, elevation, rainfall and length of growing season. Therefore, hybrids which enjoyed the greatest popularity on the basis of sales volume in 1945 in each of the eight general areas in the state, were included in the 1946 tests along with several open-pollinated varieties which are still grown in each area. This makes available performance results on the most important of the hybrids being planted in South Dakota. To best determine the value of any one hybrid or variety, its average performance in any one area over a number of years is the criterion which should be used, because in any one year the hybrid may fluctuate in its relative value due to the specific environmental conditions under which the test was conducted. However, many hybrids sold in South Dakota are not too well adapted for the short growing season and the other environmental conditions which exist. This has caused a shifting in the particular hybrids offered for sale each year and not many of those included in the 1946 tests were also tested in 1945. For this reason only one year\u27s results are given below. As better adapted hybrids are developed, and are sold year after year, average performance scores will accumulate and these tests will become more valuable. If used with discretion, the 1946 data will provide readers with information valuable as an aid in selecting hybrids for various areas of the state
Unquenched Charmonium with NRQCD - Lattice 2000
We present results from a series of NRQCD simulations of the charmonium
system, both in the quenched approximation and with n_f = 2 dynamical quarks.
The spectra show evidence for quenching effects of ~10% in the S- and
P-hyperfine splittings. We compare this with other systematic effects.
Improving the NRQCD evolution equation altered the S-hyperfine by as much as 20
MeV, and we estimate radiative corrections may be as large as 40%.Comment: Lattice 2000 (Heavy Quark Physics
Charmonium Spectrum from Quenched Anisotropic Lattice QCD
We present a detailed study of the charmonium spectrum using anisotropic
lattice QCD. We first derive a tree-level improved clover quark action on the
anisotropic lattice for arbitrary quark mass. The heavy quark mass dependences
of the improvement coefficients, i.e. the ratio of the hopping parameters
and the clover coefficients , are examined at the tree
level. We then compute the charmonium spectrum in the quenched approximation
employing anisotropic lattices. Simulations are made with
the standard anisotropic gauge action and the anisotropic clover quark action
at four lattice spacings in the range =0.07-0.2 fm. The clover
coefficients are estimated from tree-level tadpole improvement. On
the other hand, for the ratio of the hopping parameters , we adopt both
the tree-level tadpole-improved value and a non-perturbative one. We calculate
the spectrum of S- and P-states and their excitations. The results largely
depend on the scale input even in the continuum limit, showing a quenching
effect. When the lattice spacing is determined from the splitting, the
deviation from the experimental value is estimated to be 30% for the
S-state hyperfine splitting and 20% for the P-state fine structure. Our
results are consistent with previous results at obtained by Chen when
the lattice spacing is determined from the Sommer scale . We also address
the problem with the hyperfine splitting that different choices of the clover
coefficients lead to disagreeing results in the continuum limit.Comment: 43 pages, 49 eps figures, revtex; minor changes, version to appear in
Physical Review
Gauge Theories on a 2+2 Anisotropic Lattice
The implementation of gauge theories on a four-dimensional anisotropic
lattice with two distinct lattice spacings is discussed, with special attention
to the case where two axes are finely and two axes are coarsely discretized.
Feynman rules for the Wilson gauge action are derived and the renormalizability
of the theory and the recovery of the continuum limit are analyzed. The
calculation of the gluon propagator and the restoration of Lorentz invariance
in on-shell states is presented to one-loop order in lattice perturbation
theory for on both 2+2 and 3+1 lattices.Comment: 27 pages, uses feynmf. Font compatibility adjuste
One-Loop Self Energy and Renormalization of the Speed of Light for some Anisotropic Improved Quark Actions
One-loop corrections to the fermion rest mass M_1, wave function
renormalization Z_2 and speed of light renormalization C_0 are presented for
lattice actions that combine improved glue with clover or D234 quark actions
and keep the temporal and spatial lattice spacings, a_t and a_s, distinct. We
explore a range of values for the anisotropy parameter \chi = a_s/a_t and treat
both massive and massless fermions.Comment: 45 LaTeX pages with 4 postscript figure
O(a)-improved quark action on anisotropic lattices and perturbative renormalization of heavy-light currents
We investigate the Symanzik improvement of the Wilson quark action on
anisotropic lattices. Taking first a general action with nearest-neighbor and
clover interactions, we study the mass dependence of the ratio of the hopping
parameters, the clover coefficients, and an improvement coefficient for
heavy-light vector and axial vector currents. We show how tree-level
improvement can be achieved. For a particular choice of the spatial Wilson
coupling, the results simplify, and improvement is possible.
(Here is the bare quark mass and the temporal lattice spacing.)
With this choice we calculate the renormalization factors of heavy-light
bilinear operators at one-loop order of perturbation theory employing the
standard plaquette gauge action.Comment: 26 pages, 8 figure
Prediction of Electrolyte Distribution in Technical Gas Diffusion Electrodes From Imaging to SPH Simulations
The performance of the gas diffusion electrode GDE is crucial for technical processes like chlorine alkali electrolysis. The function of the GDE is to provide an intimate contact between gaseous reactants, the solid catalyst, and the liquid electrolyte. To accomplish this, the GDE is composed of wetting and non wetting materials to avoid electrolyte breakthrough. Knowledge of the spatial distribution of the electrolyte in the porous structure is a prerequisite for further improvement of GDE. Therefore, the ability of the electrolyte to imbibe into the porous electrode is studied by direct numeric simulations in a reconstructed porous electrode. The information on the geometry, including the information on silver and PTFE distribution of the technical GDE, is extracted from FIB SEM imaging including a segmentation into the different phases. Modeling of wetting phenomena inside the GDE is challenging, since surface tension and wetting of the electrolyte on silver and PTFE surfaces must be included in a physically consistent manner. Recently, wetting was modeled from first principles on the continuum scale by introducing a contact line force. Here, the newly developed contact line force model is employed to simulate two phase flow in the solid microstructures using the smoothed particle hydrodynamics SPH method. In this contribution, we present the complete workflow from imaging of the GDE to dynamic SPH simulations of the electrolyte intrusion process. The simulations are used to investigate the influence of addition of non wetting PTFE as well as the application of external pressure differences between the electrolyte and the gas phase on the intrusion proces
Anterior gradient 2 and 3 â two prototype androgenâresponsive genes transcriptionally upregulated by androgens and by oestrogens in prostate cancer cells
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96748/1/febs12118.pd
Comparison Studies of Finite Momentum Correlators on Anisotropic and Isotropic Lattices
We study hadronic two- and three-point correlators relevant for heavy to
light pseudoscalar meson semi-leptonic decays, using Symanzik improved glue,
D234 light quark and NRQCD heavy quark actions. Detailed comparisons are made
between simulations on anisotropic and isotropic lattices involving finite
momentum hadrons. We find evidence that having an anisotropy helps in
extracting better signals at higher momenta. Initial results for the form
factors f_+(q^2) and f_0(q^2) are presented with tree-level matching of the
lattice heavy-light currents.Comment: 43 pages with 50 postscript figure
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