56,091 research outputs found
Towards QCD thermodynamics using exact chiral symmetry on lattice
The thermodynamics of massless ideal gas of overlap quarks has been
investigated numerically for both zero and nonzero baryon chemical potential
. While the parameter M has been shown to be irrelevant in the continuum
limit, it is shown numerically that the continuum limit can be reached with
relatively coarser lattices for certain range of M. Numerical limitation of the
existing method of introduction of chemical potential in the overlap formalism
is discussed. We have also studied the energy density of free domain wall
fermions in the absence of and estimated the extent of lattice in the
fifth dimension for which the overlap results are recovered.
Interestingly, this value of is also minimum for the same range of M
found in the overlap case.Comment: 5 pages, 4 figures, to appear in the proceedings of the 20th
International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions:
Quark Matter 2008 (QM2008
Groundwater research and management: integrating science into management decisions. Proceedings of IWMI-ITP-NIH International Workshop on "Creating Synergy Between Groundwater Research and Management in South and Southeast Asia," Roorkee, India, 8-9 February 2005
Groundwater management / Governance / Groundwater development / Artificial recharge / Water quality / Aquifers / Groundwater irrigation / Water balance / Simulation models / Watershed management / Water harvesting / Decision making / South East Asia / Bangladesh / China / India / Nepal / Pakistan / Syria
Radiating spherical collapse with heat flow
We present here a simple model of radiative gravitational collapse with
radial heat flux which describes qualitatively the stages close to the
formation of a superdense cold star. Starting with a static general solution
for a cold star, the model can generate solutions for the earlier evolutionary
stages. The temporal evolution of the model is specified by solving the
junction conditions appropriate for radiating gravitational collapse.Comment: 13 pages, including 3 figures, submitted to IJMP-
Un nuevo método en la determinación del cromo hexavalente total en cemento Portland puzolánico
Variamine blue was used first time for the detection of hexavalent chromium from cement samples. In present method, cement was treated sequentially with water, sulphate and carbonate buffer to extract soluble, sparingly soluble and insoluble hexavalent chromium respectively. Extracted Cr (VI) was determined using variamine blue as chromogenic reagent. The determination is based on the reaction of hexavalent chromium with potassium iodide in an acid medium to liberate iodine. This oxidizes variamine blue to form a violet coloured species having an absorption to maximum at 556 nm. Energy-dispersive X-ray spectroscopy (EDX) and Infrared Spectroscopy (IR) confirmed the complete extraction of hexavalent chromium by sequential extraction process. SRM 2701 (Reference material from NIST, USA) was used for revalidating the results. The percentage of recovery for proposed and reference method (diphelycarbazide method) varied from 98.5 to 101 and 97.5 to 100.5. Whereas, their relative error percentage varied from -1.5 to 0.33 and -2.5 to 0.5.El azul de variamina se utilizó por primera vez para la detección de cromo hexavalente en muestras de cemento. En el presente método, el cemento se trató secuencialmente con agua, y tampones sulfato y carbonato para extraer el cromo hexavalente soluble, poco soluble e insoluble, respectivamente. El Cr (VI) extraÃdo se determinó utilizando azul de variamina como reactivo cromógeno, por reacción del cromo hexavalente con yoduro de potasio en un medio ácido para liberar yodo. Esto oxida al azul de variamina para formar una especie de color violeta con una absorción máxima a 556 nm. El análisis por energÃa dispersiva de rayos X (EDX) y la espectroscopÃa de infrarrojos (IR) confirmaron la extracción completa de cromo hexavalente mediante el proceso de extracción secuencial. Se utilizó SRM 2701 (material de referencia de NIST, EE.UU.) para validar los resultados. El porcentaje de recuperación para el método propuesto frente al de referencia (método de la difenilcarbazida) varió de 98.5 a 101 y 97.5 a 100.5, mientras que su porcentaje de error relativo varió de -1.5 a 0.33 y -2.5 a 0.5
Nematodes associated with cocoa hybrids and clones in Bahia, Brasil.
Cocoa is next to coffee and soybean among Brazilian export commodities. Cocoa produced in the State of Bahia the years 1978/79 earned in foreign Exchange worth one billion dollars. Susceptibility of cocoa clones and hybrids have been studied under greenhouse conditions, but nothing is known about nematode association with cocoa hybrids and clones under field conditions, that is why the present study wasunder taken
Anomalies at finite density and chiral fermions
Using perturbation theory in the Euclidean (imaginary time) formalism as well
as the non-perturbative Fujikawa method, we verify that the chiral anomaly
equation remains unaffected in the presence of nonzero chemical potential,
. We extend our considerations to fermions with exact chiral symmetry on
the lattice and discuss the consequences for the recent Bloch-Wettig proposal
for the Dirac operator at finite chemical potential. We propose a new simpler
method of incorporating and compare it with the Bloch-Wettig idea.Comment: 12 pages, 3 figures,some typos corrected, a better proof for the \mu
independence of anomaly is given in section IIB, v4: the published versio
Electrochemical incineration of wastes
The novel technology of waste removal in space vehicles by electrochemical methods is presented to convert wastes into chemicals that can be eventually recycled. The important consideration for waste oxidation is to select a right kind of electrode (anode) material that should be stable under anodic conditions and also a poor electrocatalyst for oxygen and chlorine evolution. On the basis of long term electrolysis experiments on seven different electrodes and on the basis of total organic carbon reduced, two best electrodes were identified. The effect of redox ions on the electrolyte was studied. Though most of the experiments were done in mixtures of urine and waste, the experiments with redox couples involved 2.5 M sulfuric acid in order to avoid the precipitation of redox ions by urea. Two methods for long term electrolysis of waste were investigated: (1) the oxidation on Pt and lead dioxide electrodes using the galvanostatic methods; and (2) potentiostatic method on other electrodes. The advantage of the first method is the faster rate of oxidation. The chlorine evolution in the second method is ten times less then in the first. The accomplished research has shown that urine/feces mixtures can be oxidized to carbon dioxide and water, but current densities are low and must be improved. The perovskite and Ti4O7 coated with RuO2 are the best electrode materials found. Recent experiment with the redox agent improves the current density, however, sulphuric acid is required to keep the redox agent in solution to enhance oxidation effectively. It is desirable to reduce the use of acid and/or find substitutes
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