23,430 research outputs found
The locality of the square-root method for improved staggered quarks
We study the effects of improvement on the locality of square-rooted
staggered Dirac operators in lattice QCD simulations. We find the localisation
lengths of the improved operators (FAT7TAD and ASQTAD) to be very similar to
that of the one-link operator studied by Bunk et al., being at least the
Compton wavelength of the lightest particle in the theory, even in the
continuum limit. We conclude that improvement has no effect. We discuss the
implications of this result for the locality of the nth-rooted fermion
determinant used to reduce the number of sea quark flavours, and for possible
staggered valence quark formulations
Study made of corrosion resistance of stainless steel and nickel alloys in nuclear reactor superheaters
Experiments performed under conditions found in nuclear reactor superheaters determine the corrosion rate of stainless steel and nickel alloys used in them. Electropolishing was the primary surface treatment before the corrosion test. Corrosion is determined by weight loss of specimens after defilming
Directed Explicit Model Checking with HSF-SPIN
We present the explicit state model checker HSF-SPIN which is based on the model checker SPIN and its Promela modeling language. HSF-SPIN incorporates directed search algorithms for checking safety and a large class of LTL-specified liveness properties. We start off from the A* algorithm and define heuristics to accelerate the search into the direction of a specified failure situation. Next we propose an improved nested depth-first search algorithm that exploits the structure of Promela Never-Claims. As a result of both improvements, counterexamples will be shorter and the explored part of the state space will be smaller than with classical approaches, allowing to analyze larger state spaces. We evaluate the impact of the new heuristics and algorithms on a set of protocol models, some of which are real-world industrial protocols
Loss of redundant gene expression after polyploidization in plants
Based on chromosomal location data of genes encoding 28 biochemical systems in allohexaploid wheat,Triticum aestivum L. (genomes AABBDD), it is concluded that the proportions of systems controlled by triplicate, duplicate, and single loci are 57%, 25%, and 18% respectively
Mitigating Cotton Revenue Risk Through Irrigation, Insurance, and Hedging
This study focuses on managing cotton production and marketing risks using combinations of irrigation levels, put options (as price insurance), and crop insurance. Stochastic cotton yields and prices are used to simulate a whole-farm financial statement for a 1,000 acre furrow irrigated cotton farm in the Texas Lower Rio Grande Valley under 16 combinations of risk management strategies. Analyses for risk-averse decision makers indicate that multiple irrigations are preferred. The benefits to purchasing put options increase with yields, as they are more beneficial when higher yields are expected from applying more irrigation applications. Crop insurance is strongly preferred at lower irrigation levels.cotton, crop insurance, irrigation, options, puts, risk, simulation, stochastic efficiency with respect to a function, Farm Management, Risk and Uncertainty, D81, Q12, Q15,
The Index Theorem and Universality Properties of the Low-lying Eigenvalues of Improved Staggered Quarks
We study various improved staggered quark Dirac operators on quenched gluon
backgrounds in lattice QCD generated using a Symanzik-improved gluon action. We
find a clear separation of the spectrum into would-be zero modes and others.
The number of would-be zero modes depends on the topological charge as expected
from the Index Theorem, and their chirality expectation value is large
(approximately 0.7). The remaining modes have low chirality and show clear
signs of clustering into quartets and approaching the random matrix theory
predictions for all topological charge sectors. We conclude that improvement of
the fermionic and gauge actions moves the staggered quarks closer to the
continuum limit where they respond correctly to QCD topology.Comment: 4 pages, 3 figure
Electronic Structure of Cu_(1-x)Ni_xRh_2S_4 and CuRh_2Se_4: Band Structure Calculations, X-ray Photoemission and Fluorescence Measurements
The electronic structure of spinel-type Cu_(1-x)Ni_xRh_2S_4 (x = 0.0, 0.1,
0.3, 0.5, 1.0) and CuRh_2Se_4 compounds has been studied by means of X-ray
photoelectron and fluorescent spectroscopy. Cu L_3, Ni L_3, S L_(2,3) and Se
M_(2,3) X-ray emission spectra (XES) were measured near thresholds at Beamline
8.0 of the Lawrence Berkeley Laboratory's Advanced Light Source. XES
measurements of the constituent atoms of these compounds, reduced to the same
binding energy scale, are found to be in excellent agreement with XPS valence
bands. The calculated XES spectra which include dipole matrix elements show
that the partial density of states reproduce experimental spectra quite well.
States near the Fermi level (E_F) have strong Rh d and S(Se) p character in all
compounds. In NiRh_2S_4 the Ni 3d states contribute strongly at E_F, whereas in
both Cu compounds the Cu 3d bands are only ~1 eV wide and centered ~2.5 eV
below E_F, leaving very little 3d character at E_F. The density of states at
the Fermi level is less in NiRh_2S_4 than in CuRh_2S_4. This difference may
contribute to the observed decrease, as a function of Ni concentration, in the
superconducting transition temperature in Cu_(1-x)Ni_xRh_2S_4. The density of
states of the ordered alloy Cu_(1/2)Ni_(1/2)Rh_2S_4 shows behavior that is more
``split-band''-like than ``rigid band''-like.Comment: 7 pages of text, 11 trailing figures, updated to fix faulty
postscript in Fig.
The multiple junction edge illuminated solar cell
The multiple junction edge illuminated solar cell was devised for high voltage low current applications. Devices to be flight tested in early 1974 with 96 series connected PNN+ junctions in a 2 cm X 2.3 cm size deliver 36 volts at 1 milliampere. Test data of M-J cells fabricated with resistivities of 10, 50, 100, 200, 450, and 1000 ohm cm silicon are presented and problem areas are discussed. An additional potential application of the M-J cell lies in ultilization of its high intensity performance that has been demonstrated at levels in excess of 100 AMO suns
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