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The finite-temperature electronic transport properties of the CoSi compound and its alloys with 3d transition metals including Fe, Cr, Mn, and Ni are elucidated by using the Korringa–Kohn–Rostoker Green's function method combined with the coherent potential approximation. On the basis of the linear response theory, the electrical resistivity of the CoSi compound observed in the experiments could be quantitatively reproduced by taking into account both local phonon displacements and antisite disorder effects. Our calculations reveal the formation of Co–Si disorders with a very small concentration and their dominant effect on resistivity in a low-temperature range. Moreover, alloying transition metals with CoSi also led to significant changes in the states of conduction electrons, which is interesting as a typical example of a rigid band scheme. Notably, we found that alloying with Ni could reduce the system's resistivity by more than 25%, suggesting its potential for enhancing the power factor of the CoSi compound for thermoelectric applications. [ABSTRACT FROM AUTHOR]

The relationship between the valence states of Eu ions in Eu-doped GaN and their magnetic properties is investigated by experiments and simulations. X-ray measurements have verified that the valence states of Eu ions can be controlled through growth temperature and codopants and that the highest concentration of divalent Eu ions is found in samples grown at 700 ° C by codoping with Si and O. According to our phenomenological analysis, magnetoresistance measurement implies the presence of Zener's p–f exchange interaction. However, the magnetization dependence on an external magnetic field shows non-hysteretic sigmoidal curves in all the samples. Our simulations suggest that this is due to the formation of nanostructures of the magnetic impurities in the samples by spinodal decomposition. [ABSTRACT FROM AUTHOR]

This study applied volumetric analysis and voxel-based morphometry (VBM) of brain magnetic resonance (MR) images to assess whether correlations exist between global and regional gray/white matter volume and the cognitive functions of semantic memory and short-term memory, which are relatively well preserved with aging, using MR image data from 109 community-dwelling healthy elderly individuals. We used the Information and Digit Span subtests of the Wechsler Adult Intelligent Scale-Revised as measures of semantic memory and short-term memory, respectively. We found significant positive correlations between the gray matter ratio, the percentage of gray matter volume in the intracranial volume, and performance on the Digit Span subtest, and between the regional gray matter volumes of the bilateral anterior temporal lobes and performance on the Information subtest. No significant correlations between performance on the cognitive tests and white matter volume were found. Our results suggest that individual variability in specific cognitive functions that are relatively well preserved with aging is accounted for by the variability of gray matter volume in healthy elderly subjects. (Contains 1 figure and 3 tables.)

In 2016, a countermeasure was announced against the Nankai Trough long‐period and long‐duration ground motions (LPGMs) in Japan. However, the response spectrum method (RSM), indicated by the Ministry of Construction notification Vol. 2009 (MCN), was out of the countermeasure. An RSM considering characteristic changes due to repeated deformations has also been proposed. However, since the damping correction formula of MCN was used, its applicability to LPMGs has not been sufficiently investigated. In this paper, a method is proposed to evaluate the influence of characteristic changes due to repeated deformations using RSM for LPGMs and seismically isolated buildings using the lead plug‐inserted laminated rubber (LRB). [ABSTRACT FROM AUTHOR]

Carbon deposition on Ni-based anode is well-known as a major barrier for the practical use and commercialization of hydrocarbon-fuelled solid oxide fuel cells (SOFCs). In this work, Co alloying in Ni-YSZ was studied as an alternative anode material for using CH4 as a fuel. The Ni-YSZ and Ni-Co alloyed-YSZ were prepared by the traditional impregnation method without further mixing processes. After sintering and reduction in H2 atmosphere, the introduced Co can completely dissolved into the Ni lattice and changed the morphology with an increase in the Ni-YSZ grain size and showed a better uniform microstructure. The Co alloying also enhanced the electrochemical performance under CH4 fuel by reducing the resistance and anodic overvoltage. Moreover, the Co addition enhanced the stability of the cell with CH4 a constant load current of 80 mA for 60 h. This performance related to the carbon deposition on the anode surface. The Co alloying showed a high efficiency to suppress the carbon deposition and improved the electrochemical performance of an SOFC cell operating under CH4 fuel.

Recently, Fe-doped semiconductors have been attracting much attention as ferromagnetic semiconductors due to the possibility that they may exhibit high Curie temperatures and low power consumption and that they may be useful for high-speed spin devices. High Curie temperature ferromagnetism has been observed in Fe-doped InAs, from which both n- and p-type ferromagnetic semiconductors can be fabricated. In order to obtain a higher Curie temperature than that of (In, Fe)As, we have focused on GaSb and InSb as host semiconductors. We have investigated their electronic structures, magnetic properties, and structural stability by using the Korringa-Kohn-Rostoker Green's function method within density functional theory. We have found that (Ga, Fe)Sb and (In, Fe)Sb show complex magnetic properties, which are determined by the correlation between magnetic exchange coupling constants and chemical pair interactions. Isoelectronic Fe-doped GaSb and InSb have strong antiferromagnetic interactions due to the super-exchange mechanism. By shifting the Fermi level–i.e., by n- or p-type doping–(Ga, Fe)Sb and (In, Fe)Sb can be made to undergo a magnetic transition from antiferromagnetic to ferromagnetic ordering. This transition can be well understood in terms of the Alexander-Anderson-Moriya mechanism. Our calculations indicate the possibility of manipulating (Ga, Fe)Sb and (In, Fe)Sb to achieve high Curie temperatures. [ABSTRACT FROM AUTHOR]

Background. The effects of subthalamic nuclear deep brain stimulation therapy (STN-DBS) and combined postoperative rehabilitation for patients with Parkinson's disease with postural instability have yet to be well reported. This study investigated the effects of short-term postoperative rehabilitation with STN-DBS on physical function in patients with Parkinson's disease. Methods. Patients diagnosed with Parkinson's disease who were admitted to our hospital for STN-DBS surgery were included in this study. Data were prospectively collected and retrospectively analyzed. Postoperative rehabilitation consisted of muscle-strengthening exercises, stretching, and balance exercises for 40–60 minutes per day for approximately 14 days. The Mini-Balance Evaluation Systems Test (Mini-BESTest), Timed Up and Go test (TUG) seconds and steps, Trunk Impairment Scale (TIS), seconds for 10 times toe-tapping, lower limb extension torque using StrengthErgo240, and center of pressure sway in the quiet standing posture were evaluated preoperatively, postoperatively, and at discharge. Mini-BESTest changes were also evaluated in the two groups classified by the presence or absence of postural instability. One-way and two-way repeated measures analyses of variance were performed for each of the three periods of change, and paired t-tests with the Bonferroni method were performed as multiple comparison tests. A stepwise multiple regression model was used to identify factors associated with balance improvement. Results. A total of 60 patients with Parkinson's disease were included, and there were significant increases in Mini-BESTest, TIS, StrengthErgo240, and postural sway during closed-eye standing compared to pre- and postoperative conditions at discharge (p < 0.05), and they decreased significantly compared to the postoperative period (p < 0.05). On stepwise multiple regression analysis, decreased steps of TUG and improvement of TIS scores were related to improvement of the Mini-BESTest (p < 0.05). In addition, Mini-BESTest scores in both groups with and without postural instability were significantly increased at discharge compared to preoperative and postoperative conditions (p < 0.01). Conclusion. Postoperative rehabilitation combined with STN-DBS may provide short-term improvements in physical function compared with the preoperative medicated status. The improvements in gait step length and trunk function may be important factors for obtaining improvement of postoperative postural stability. [ABSTRACT FROM AUTHOR]

We present a first principle study of the half-metallicity and ferromagnetism in half-heusler alloys XYSi (X = Ni, Pd and Pt; Y = Cr and Mn). The equilibrium lattice constants are predicted by means of the ultrasoft pseudo-potential method. The electronic structure and magnetic exchange interaction of various alloys are investigated within KKR-LSDA. The Curie temperature is predicted by using the Monte Carlo simulation, the random phase and mean field approximations, as well. The role of elements X, Y components and influence of the lattice parameters in stabilizing half-metallicity and ferromagnetism are discussed. Except PdMnSi, alloys are half-metallic at equilibrium lattice constant. The Curie temperatures of 634 K, 785 K, and 1076 K for NiCrSi, PtMnSi and NiMnSi, respectively, are predicted by Monte Carlo simulation. The structural stability of [C1.sub.b] is also considered. Index Terms--Ab initio calculation, half-heusler, high-[T.sub.c], ferromagnetism, half-metallic, spintronics.

The development of flexible thermoelectric devices is gradually attracting increasing attention, particularly in the field of material design. In this study, we use first-principles calculations combined with Boltzmann equations to study the electronic and transport properties of Ag2S1−xSex, a key material with many important properties and extraordinary ductility, as well as a wide range of thermoelectric applications. The effect of Se alloying on the electronic structure of Ag2S and defect formation is investigated, and the role of alloying in increasing the n-type carrier concentration is discussed. The electron–phonon coupling approximation is used to reproduce the experimentally observed transport properties reasonably well, which shows that this scattering model is suitable for predicting the transport properties of semiconductors in thermoelectric applications. [ABSTRACT FROM AUTHOR]

The problem of biological invasion is an issue of increasing significance in conservation ecology. Fisher equation is one of the traditional methods to describe biological invasion. In ecosystems, however, species usually live in patchy environments. In this study, a modified Fisher equation is derived, where the recently developed "swapping migration" is applied and the relation between invasion velocity and patch capacity is discussed. [ABSTRACT FROM AUTHOR]