36 research outputs found

    The Critical Finite Size Scaling Relation of the Order-Parameter Probability Distribution for the Three-Dimensional Ising Model on the Creutz Cellular Automaton

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    We study the order parameter probability distribution at the critical point for the three-dimensional spin-1/2 and spin-1 Ising models on the simple cubic lattice with periodic boundary conditions. The finite size scaling relation for the order parameter probability distribution is tested and verified numerically by microcanonical Creutz cellular automata simulations. The state critical exponent \delta, which characteries the far tail regime of the scaling order parameter probability distribution, is estimated for 3-d Ising models using the cellular automaton simulations at the critical temperature. The results are in good agreement with the monte carlo calculations.Comment: 8 pages 5 figure

    Advancement in the pressureless sintering of CP titanium using high-frequency induction heating

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    High-frequency induction heating is applied as an alternative heating source for pressureless sintering of commercially pure Ti powders, aiming to intensify the sintering process. The effects of the process parameters on the properties of the sintered material are systematically studied. The initial powder compact density is the most influential parameter permitting sintered structures with highly porous to almost fully dense appearance. Short heating time combined with sintering to temperatures just above the β-transus resulted in a strong diffusion bonding between the Ti powder particles, and grain growth is observed at the former boundaries of the neighboring powder particles. The dimpled appearance of the fracture surface at those regions confirmed the strong metallic interparticle bonding. Tensile properties comparable to those of Ti-Grade 3 and Ti-Grade 4 are achieved, which also demonstrates the efficiency of the induction sintering process. A mechanism explaining the fast and efficient sintering is proposed. The process has the added advantage of minimizing the oxygen pickup

    The rapid visualization of resistivity inhomogeneities in high-resistivity semiconductor films

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    This paper describes for the first time an application of an ionization type semiconductor photographic system using a chalcopyrite-type semiconductor (CuInSe2) copper-indium-diselenide film as a target for rapid visulization of resistivity inhomogeneities. The CuInSe2 semiconductor films with a resistivity of 10(7) Omega cm (thickness 0.25 mu m) in a planar gas discharge cell, have been studied. A measurement is realized by recording the spatial distribution of the gas discharge radiation intensity between two parallel electrodes. A gas discharge gap has been formed by a dielectric separator with thicknesses ranging from 40 to 60 mu m. A discharge has been realized in air at pressures from 760-60 Torr. The assessment of the resistivity inhomogeneities is then based on an analysis of the discharge radiation, visualized by a photograph taken through the SnO2 film

    Structural, electronic and phonon properties of MoTa and MoNb: a density functional investigation

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    WOS: 000279613500018First-principles calculations were performed to investigate the structural, electronic and phonon properties of MoTa and MoNb in the CsCl (B2) phase. The calculated lattice constants, static bulk modulus and first-order pressure derivative of the bulk modulus are in good agreement with available experimental data and previous theoretical predictions. Electronic band structures and partial and total densities of states have been derived for MoTa and MoNb. The band structures show metallic character; the conductivity is mostly governed by Mo-4d and Ta-5d (Nb-4d) states. A linear-response approach to the density functional theory is used to derive phonon dispersion curves and the density of states for MoTa and MoNb. Zone centre optical phonon modes of MoTa and MoNb are found to be at 6.46 and 7.24 THz, respectively.Gazi UniversityGazi University [05/2009-39]This work was supported by the Gazi University Research Project Unit under project no. 05/2009-39

    Line x tester analysis and estimating combining abilities for yield and some yield components in bread wheat

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    Estimating of combining ability is useful to assess genotypes and elucidate the nature and magnitude of gene actions involved. Aim of this study was to determine the combining abilities of some wheat genotypes for yield and some yield related traits by using line x tester mating design. Four advanced wheat lines and one cultivar were used as lines and four wheat genotypes were used as testers. The specific combining ability (SCA) effects were generally found higher than general combining ability effects (GCA) in terms of the agronomic traits studied. As a result, low ratios of ?2GCA/?2sCA, (?2D/?2A)1/2 and low narrow sense heritabilities showed that non-additive effects controlled the traits studied. Hence, the selection process for superior individual plants should be postponed to further generations like F4 or F5. © 2015, Society of Field Crops Science. All rights reserved

    Beam switching reflectarray using RF MEMS technology

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    The effect of epidural and general anesthesia on newborn rectal temperature at elective cesarean section

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    Both epidural and general anesthesia can impair thermoregulatory mechanisms during surgery. However, there is lack of information about the effects of different methods of anesthesia on newborn temperature. The purpose of this study was to determine whether there are differences in newborn rectal temperature related to type of anesthesia. Sixty-three pregnant women were randomly assigned to receive general or epidural anesthesia. Maternal core temperature was measured three times with a rectal probe just before anesthesia, at the beginning of surgery and at delivery. In addition, umbilical vein blood was sampled for pH. The rectal temperatures of the babies were recorded immediately after delivery, and Apgar scores were determined 1, 5, and 10 min after birth. The duration of anesthesia and the volume of intravenous fluid given during the procedure (833 ± 144 vs 420 ± 215 mL) were significantly higher in the epidural group than in the general anesthesia group (P < 0.0001). Maternal rectal temperatures were not different in both groups at all measurements. In contrast, newborn rectal temperatures were lower in the epidural anesthesia group than in the general anesthesia group (37.4 ± 0.3 vs 37.6 ± 0.3°C; P < 0.05) immediately after birth. Furthermore, the umbilical vein pH value (7.31 ± 0.05 vs 7.33 ± 0.01; P < 0.05) and Apgar scores at the 1st-min measurement (8.0 ± 0.9 vs 8.5 ± 0.7; P < 0.05) were lower in the epidural anesthesia group than in the general anesthesia group. Since epidural anesthesia requires more iv fluid infusion and a longer time for cesarean section, it involves a risk of a mild temperature reduction for the baby which, however, did not reach the limits of hypothermia
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