127 resultados para Two-phase line


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Objective Asymmetry in brain structure and function is implicated in the pathogenesis of psychiatric disorders. Although right hemisphere abnormality has been documented in obsessive-compulsive disorder (OCD), cerebral asymmetry is rarely examined. Therefore, in this study, we examined anomalous cerebral asymmetry in OCD patients using the line bisection task. Methods A total of 30 patients with OCD and 30 matched healthy controls were examined using a reliable and valid two-hand line bisection (LBS) task. The comparative profiles of LBS scores were analysed using analysis of covariance. Results Patients with OCD bisected significantly less number of lines to the left and had significant rightward deviation than controls, indicating right hemisphere dysfunction. The correlations observed in this study suggest that those with impaired laterality had more severe illness at baseline. Conclusions The findings of this study indicate abnormal cerebral lateralisation and right hemisphere dysfunction in OCD patients.

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In this paper we derive an approach for the effective utilization of thermodynamic data in phase-field simulations. While the most widely used methodology for multi-component alloys is following the work by Eiken et al. (2006), wherein, an extrapolative scheme is utilized in conjunction with the TQ interface for deriving the driving force for phase transformation, a corresponding simplistic method based on the formulation of a parabolic free-energy model incorporating all the thermodynamics has been laid out for binary alloys in the work by Folch and Plapp (2005). In the following, we extend this latter approach for multi-component alloys in the framework of the grand-potential formalism. The coupling is applied for the case of the binary eutectic solidification in the Cr-Ni alloy and two-phase solidification in the ternary eutectic alloy (Al-Cr-Ni). A thermodynamic justification entails the basis of the formulation and places it in context of the bigger picture of Integrated Computational Materials Engineering. (C) 2015 Elsevier Ltd. All rights reserved.

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Heterophase structures in lead-free perovskite-type ferroelectric solid solutions of (1 - z)(Na0.5Bi0.5)TiO3 - zBaTiO(3) are analysed for a few critical compositions near the morphotropic phase boundary (z = 0.05-0.07). Examples of the phase coexistence and elastic matching of the phases from different symmetry groups are considered to find optimum volume fractions of specific domain types and coexisting phases at the complete stress relief in two-phase samples. Some interrelations between these volume fractions are described using variants of the domain arrangement at changes in the composition and unit-cell parameters. The evaluated room-temperature volume fractions of the ferroelectric monoclinic (Cm symmetry) and tetragonal (P4mm symmetry) phases near the morphotropic phase boundary are in agreement with experimental data.

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Amorphous carbon-sulfur (a-C:S) composite films were prepared by vapor phase pyrolysis technique. The structural changes in the a-C:S films were investigated by electron microscopy. A powder X-ray diffraction (XRD) study depicts the two-phase nature of a sulfur-incorporated a-C system. The optical bandgap energy shows a decreasing trend with an increase in the sulfur content and preparation temperature. This infers a sulfur incorporation and pyrolysis temperature induced reduction in structural disorder or increase in sp (2) or pi-sites. The presence of sulfur (S 2p) in the a-C:S sample is analyzed by the X-ray photoelectron spectroscopy (XPS). The sp (3)/sp (2) hybridization ratio is determined by using the XPS C 1s peak fitting, and the results confirm an increase in sp (2) hybrids with sulfur addition to a-C. The electrical resistivity variation in the films depends on both the sulfur concentration and the pyrolysis temperature.

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Loop heat pipe is a passive two-phase heat transport device that is gaining importance as a part of spacecraft thermal control systems and also in applications (such as in avionic cooling and submarines). Hard fill of a loop heat pipe occurs when the compensation chamber is full of liquid. A theoretical study is undertaken to investigate the issues underlying the loop beat pipe hard-fill phenomenon. The results of the study suggest that the mass of charge and the presence of a bayonet have significant impact on the loop heat pipe operation. With a largern mass of charge, a loop heat pipe hard fills at a lower heat load. As the heat load increases, there is a steep rise in the loop heat pipe operating temperature. In a loop heat pipe with a saturated compensation chamber, and also in a hard-filled loop heat pipe without a bayonet, the temperature of the compensation chamber and that of the liquid core are nearly equal. When a loop heat pipe with a bayonet hard fills, the compensation chamber and the evaporator core temperatures are different.

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The structures of (1 - x) Na0.5Bi0.5TiO3-(x) CaTiO3 at room temperature have been investigated using neutron powder diffraction and dielectric studies. The system exhibits an orthorhombic (Pbnm) structure for x >= 0.15 and rhombohedral (R3c) for x <= 0.05. For x = 0.10, though the neutron diffraction pattern shows features of the orthorhombic (Pbnm) structure, Rietveld refinement using this structure shows a drastic reduction in the in-phase tilt angle (similar to 4 degrees) as compared to the corresponding value (similar to 8 degrees) for a neighbouring composition x = 0.15. The neutron diffraction pattern of x = 0.10 could be fitted equally well using a two-phase model (R3c + Pbnm) with orthorhombic as the minor phase (22%), without the need for a drastic decrease in the in-phase tilt angle. The dielectric studies of x = 0.10 revealed the presence of the polar R3c phase, thereby favouring the phase coexistence model, instead of a single-phase Pbnm structure, for this composition.

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Design criteria and full-diversity Distributed Space Time Codes (DSTCs) for the two phase transmission based cooperative diversity protocol of Jing-Hassibi and the Generalized Nonorthogonal Amplify and Forward (GNAF) protocol are reported, when the relay nodes are assumed to have knowledge of the phase component of the source to relay channel gains. It is shown that this under this partial channel state information (CSI), several well known space time codes for the colocated MIMO (Multiple Input Multiple Output) channel become amenable for use as DSTCs. In particular, the well known complex orthogonal designs, generalized coordinate interleaved orthogonal designs (GCIODs) and unitary weight single symbol decodable (UW-SSD) codes are shown to satisfy the required design constraints for DSTCs. Exploiting the relaxed code design constraints, we propose DSTCs obtained from Clifford Algebras which have low ML decoding complexity.

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The standard molar Gibbs free energy of formation of Co2TiO4, CoTiO3,and CoTi2O5 as a function of temperature over an extended range (900 to 1675) K was measured using solid-state electrochemical cells incorporating yttria-stabilized zirconia as the electrolyte, with CoO as reference electrode and appropriate working electrodes. For the formation of the three compounds from their component oxides CoO with rock-salt and TiO2 with rutile structure, the Gibbs free energy changes are given by:Delta(f)G degrees((ox))(Co2TiO4) +/- 104/(J . mol(-1)) = -18865 - 4.108 (T/K)Delta(f)G degrees((ox))(CoTiO3) +/- 56/(J . mol(-1)) = -19627 + 2.542 (T/K) Delta(f)G degrees((ox))(CoTi2O5) +/- 52/(J . mol(-1)) = -6223 - 6.933 (T/K) Accurate values for enthalpy and entropy of formation were derived. The compounds Co2TiO4 with spinel structure and CoTi2O5 with pseudo-brookite structure were found to be entropy stabilized. The relatively high entropy of these compounds arises from the mixing of cations on specific crystallographic sites. The stoichiometry of CoTiO3 was confirmed by inert gas fusion analysis for oxygen. Because of partial oxidation of cobalt in air, the composition corresponding to the compound Co2TiO4 falls inside a two-phase field containing the spinet solid solution Co2TiO4-Co3O4 and CoTiO3. The spinel solid solution becomes progressively enriched in Co3O4 with decreasing temperature. (c) 2010 Elsevier Ltd. All rights reserved.

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A hot rolled two-phase Ti-22Al-25Nb (at.%) alloy containing the orthorhombic (O) and beta(B2) phases was subjected to thermal treatment under different conditions. The experiment was aimed to examine the recrystallization response of the beta(B2) phase (static and dynamic) to microstructure and crystallographic texture evolution using scanning electron microscopy coupled with electron backscattered diffraction (SEM-EBSD). Specimens rolled in the two-phase (O + beta(B2)) region consisted of highly deformed beta(B2) grains. The texture was close to that of the typical bcc deformation texture with a few additional texture components. A subsequent heat treatment of these rolled specimens in single beta(B2) phase region was characterized by static recrystallized beta(B2) grains with the final texture partly inherited from as-rolled material. In contrast, specimens rolled in the single beta(B2) region produced beta(B2) grains with the texture similar to that of completely dynamic recrystallized one. (C) 2010 Elsevier Ltd. All rights reserved.

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This paper presents an Artificial Neural Network (ANN) approach for locating faults in distribution systems. Different from the traditional Fault Section Estimation methods, the proposed approach uses only limited measurements. Faults are located according to the impedances of their path using a Feed Forward Neural Networks (FFNN). Various practical situations in distribution systems, such as protective devices placed only at the substation, limited measurements available, various types of faults viz., three-phase, line (a, b, c) to ground, line to line (a-b, b-c, c-a) and line to line to ground (a-b-g, b-c-g, c-a-g) faults and a wide range of varying short circuit levels at substation, are considered for studies. A typical IEEE 34 bus practical distribution system with unbalanced loads and with three- and single- phase laterals and a 69 node test feeder with different configurations are considered for studies. The results presented show that the proposed approach of fault location gives close to accurate results in terms of the estimated fault location.

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The electrical capacitance and resistance of the binary liquid mixture cyclohexane + acetonitrile are measured in the one phase and two phase regions at spot frequencies between 5 kHz and 100 kHz. This sample has a very low gravity affected (∼0.6 mK) region. In one phase region the capacitance data show a sharp, ∼0.7% increase above background within 0.5 degrees of Tc whereas the resistance has a smooth increase of ∼1.5% above background in a (T−Tc) range of 4 degrees. Two phase values of capacitance and resistance from the coexisting phases are used to determine the critical parameters Tc (critical temperature), Rc (resistance at Tc) and Cc (capacitance at Tc). A precise knowledge of these parameters reduces the uncertainty on the critical exponent 0 for C and R. The one phase capacitance data fit to an (1 - α) exponent in a limited temperature range of 0.2 degrees. Resistance data strongly support an (1 - α) exponent over the entire 5 degree range.

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The behavior of electrical resistivity in the critical region of three polar + nonpolar binary liquid systems CS2 +(CH3CO)2O, C6H12+(CH3CO)2O, and n‐C7H16+(CH3CO)2O is studied. For the mixtures with critical composition, the two phase region shows a conductivity behavior with σ1−σ2∼ (−ϵ)β with β?0.35. In the one phase region dR/dT has a singularity ϵ−b with b?0.35. A possible theory of the impurity conduction is given, which broadly explains these results. The possibility of dR/dT being positive or negative is also discussed.

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The activity of K sub 2 O in a mixture of alpha -alumina and potassium beta -alumina has been determined using a solid state galvanic cell in the temperature range 600-1000K. The cell is written such that the right hand electrode is positive. The solid electrolyte consisted of a dispersion of alpha -alumina ( approx 15 vol.%) in a matrix of K beta -alumina. The emf of the cell was found to be reversible and to vary linearly with temperature. From the emf and auxiliary data on In sub 2 O sub 3 and K sub 2 O from the literature, the activity of K sub 2 O in the two-phase mixture is obtained. The standard free energy of formation of K beta -alumina from component oxides is given. Graphs.

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Three different types of consistencies, viz., semiweak, weak, and strong, of a read-only transaction in a schedule s of a set T of transactions are defined and these are compared with the existing notions of consistencies of a read-only transaction in a schedule. We present a technique that enables a user to control the consistency of a read-only transaction in heterogeneous locking protocols. Since the weak consistency of a read-only transaction improves concurrency in heterogeneous locking protocols, the users can help to improve concurrency in heterogeneous locking protocols by supplying the consistency requirements of read-only transactions. A heterogeneous locking protocol P' derived from a locking protocol P that uses exclusive mode locks only and ensures serializability need not be deadlock-free. We present a sufficient condition that ensures the deadlock-freeness of Pprime, when P is deadlock-free and all the read-only transactions in Pprime are two phase.

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We compute the entropy and transport properties of water in the hydration layer of dipalmitoylphosphatidylcholine bilayer by using a recently developed theoretical scheme two-phase thermodynamic model, termed as 2PT method; S.-T. Lin et al., J. Chem. Phys. 119, 11792 (2003)] based on the translational and rotational velocity autocorrelation functions and their power spectra. The weights of translational and rotational power spectra shift from higher to lower frequency as one goes from the bilayer interface to the bulk. Water molecules near the bilayer head groups have substantially lower entropy (48.36 J/mol/K) than water molecules in the intermediate region (51.36 J/mol/K), which have again lower entropy than the molecules (60.52 J/mol/K) in bulk. Thus, the entropic contribution to the free energy change (T Delta S) of transferring an interface water molecule to the bulk is 3.65 kJ/mol and of transferring intermediate water to the bulk is 2.75 kJ/mol at 300 K, which is to be compared with 6.03 kJ/mol for melting of ice at 273 K. The translational diffusion of water in the vicinity of the head groups is found to be in a subdiffusive regime and the rotational diffusion constant increases going away from the interface. This behavior is supported by the slower reorientational relaxation of the dipole vector and OH bond vector of interfacial water. The ratio of reorientational relaxation time for Legendre polynomials of order 1 and 2 is approximately 2 for interface, intermediate, and bulk water, indicating the presence of jump dynamics in these water molecules. (C) 2010 American Institute of Physics. doi:10.1063/1.3494115]