1,525 research outputs found

    Substrate-tuning of correlated spin-orbit oxides revealed by optical conductivity calculations

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    We have systematically investigated substrate-strain effects on the electronic structures of two representative Sr-iridates, a correlated-insulator Sr2IrO4 and a metal SrIrO3. Optical conductivities obtained by the ab initio electronic structure calculations reveal that the tensile strain shifts the optical peak positions to higher energy side with altered intensities, suggesting the enhancement of the electronic correlation and spin-orbit coupling (SOC) strength in Sr-iridates. The response of the electronic structure upon tensile strain is found to be highly correlated with the direction of magnetic moment, the octahedral connectivity, and the SOC strength, which cooperatively determine the robustness of J(eff) = 1/2 ground states. Optical responses are analyzed also with microscopic model calculation and compared with corresponding experiments. In the case of SrIrO3, the evolution of the electronic structure near the Fermi level shows high tunability of hole bands, as suggested by previous experiments.117Ysciescopu

    Structural and magnetic study of a dilute magnetic semiconductor: Fe doped CeO2 nanoparticles

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    This paper reports the effect of Fe doping on the structure and room temperature ferromagnetism of CeO2 nanoparticles. X-ray diffraction and selective area electron diffraction measurement reflects that Ce1-xFexO2 (x = 0.0 - 0.07) nanoparticles exhibit single phase nature with cubic structure and none of the sample showed the presence of any secondary phase. The mean particle size calculated by using a transmission electron microscopy measurement was found to increase with increase in Fe content. DC magnetization measurements performed at room temperature indicates that all the samples exhibit ferromagnetism. The saturation magnetic moment has been found to increase with an increase in the Fe content.Comment: 16 Pages, 5 figure, 1 Table, Accepted in JN

    Wave hindcast from integrally coupled wave-tide-surge model of the East China sea

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    With the recent introduction of the coupled system (ADCIRC hydrodynamic and SWAN wave model) which can run on the same unstructured mesh, allowing the physics of wave-circulation interactions to be correctly resolved in both models and all energy from deep to shallow waters to be seamlessly followed, the resulting modeling system can be used extensively for the prediction of typhoon surges and usual barotropic forecast. The result confirms the necessity to incorporate the wave-current interaction effect into coastal area in the wave-tide-surge coupled model. At the same time, effects of depth-induced wave breaking, wind field, currents and sea surface elevation in prediction of\ud waves are included. Especially, we found that the wind wave significantly enhances the current and surge elevation. The resulting modeling system can be used for hindcasting (prediction) and forecasting the wave-tide-surge distribution in the environments with complex coastline, shallow water and fine sediment area like around Korean Peninsula

    Evaluation of synergistic effect between ethyl formate and phosphine for control of three species Aphids in perishable commodity

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    Methyl bromide (MB) as a fumigant for Quarantine and Pre-shipment (QPS) could offer eradication of target pests within shorter fumigation period and without phytotoxicity. Therefore, unlike MB alternatives for soil fumigation, there is no ideally MB alternative fumigant for QPS purpose, particularly for perishable commodities. It is critically important that within shorter fumigation time requires killing all target insect pests and without effect of quality and deliver treated fruit and vegetables to the final consumer. Aphids are pests frequently found in imported and exported fruit and vegetables. Aphids was known as quarantine pest hard to control when conduct short period fumigation with phosphine (PH3) and low dose of ethyl formate (EF). Ethyl formate can lead to highly sorption and phytotoxic damage of some perishable commodities such as strawberries and cut flowers, especially at lower temperature (< 8°C). Here, we reported that synergistic effect between ethyl formate and phosphine at lower dosages and temperature. The mixture of ethyl formate and phosphine had synergistic effect to control adult and nymph stages of tested cotton aphid (Aphis gossypii), green peach aphid (Myzus persicae) and turnip aphid (Lipaphis erysimi). When 0.5 mg/L of PH3 combined with different levels of EF at 5 and 20°C for 2 hours fumigation, there was significantly difference in terms of LCT50% and LCT90% values in comparison with EF or PH3 alone. This new technology could be meet QPS requirement that is shorter exposure time and less damage of perishable commodities

    Swell prediction for the East Korean coast

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    Long-period abnormally high swell waves have been generated in the East Sea near Hokkaido, Japan, in winter during the atmospheric depression. These waves, named Yorimawari in Japanese, occasionally attack the coasts of both Korea and Japan. Waves significantly higher than normal years were recorded along the east Korean coast in 2006. In 2008, the swell caused considerable damages in Toyama and the Niigata coastal area of Japan and in Anmok east coast of Korea. This paper attempts to hindcast these events using unstructured grid wave model UnSwan with input of high resolution reanalysis wind data from ECMWF. Wave heights and periods are found to be fairly well reproduced comparing with the observed values in the south of the East/Japan Sea, although the long period wave with small amplitude is hardly reproduced

    A study of semi-inclusive charmless BπXB \to \pi X decays

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    We study semi-inclusive charmless decays BπXB \to \pi X in detail, such as Bˉ0π±(0)X\bar B^0 \to \pi^{\pm (0)} X, B0π±(0)XB^0 \to \pi^{\pm (0)} X, B±π±(0)XB^{\pm} \to \pi^{\pm (0)} X, where XX does not contain a charm (anti)quark. We find that the process Bˉ0πX\bar B^0 \to \pi^- X (B0π+XB^0 \to \pi^+ X) can be particularly useful for determination of the CKM matrix element Vub|V_{ub}|. We calculate and present the branching ratio (BR) of Bˉ0πX\bar B^0 \to \pi^- X as a function of Vub|V_{ub}|, with an estimate of possible uncertainties. It is expected that the BR is an order of 10410^{-4}. Our estimation indicates that one can phenomenologically determine Vub|V_{ub}| with reasonable accuracy by measuring the BR of Bˉ0πX\bar B^0 \to \pi^- X (B0π+XB^0 \to \pi^+ X).Comment: 18 pages, 7 figures; Revtex; version accepted for publication in Eur. Phys. J.

    Development of the deep flexor tendons and lumbricalis muscle in the hand and foot: a histological study using human mid-term fetuses

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    To revisit fetal development of the deep flexor tendons of the hand and foot, we examined the paraffin-embedded histology of 20 mid-term fetuses at 8-15 weeks of estimated gestational age (35-118 mm crown-rump length or CRL). At 8-9 weeks, in front of the metacarpal bones, the flexor pollicis longus and flexor digitorum profundus muscles provided a plate-like, common tendon from which the lumbricalis muscles originated. However, in the foot, we had no evidence of such a common tendon. The flexor pollicis tendon was separated from the common tendon at 9-10 weeks possibly due to a mechanical stress from the laterally growing thumb. Notably, at the lumbricalis muscle origins at 10-12 weeks, the flexor digitorum profundus and flexor digitorum longus tendons remained undifferentiated and the primitive tenocytes were dispersed from them. The dispersed cells seemed to develop into an interface tissue between the lumbricalis muscle fiber and the deep tendon. In 3 of 5 specimens at 15 weeks, we found excess number of the flexor digitorum profundus tendons (5-7) in the proximal side of the lumbricalis muscle origin. However, the excess tendons dispersed in the lumbricalis muscle origin. The development of the lumbricalis muscle origin might follow the tendon splitting for 4 fingers. However, conversely, we hypothesized that the developing lumbricalis muscles re-arranged the deep flexor tendons to provide a configuration of “one deep tendon per one finger (or toe)”. The quadrates plantae muscle seemed not to contribute on the re-arrangement

    Implantation of bone marrow-derived buffy coat can supplement bone marrow stimulation for articular cartilage repair

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    SummaryObjectiveBone marrow stimulation (BMS) has been regarded as a first line procedure for repair of articular cartilage. However, repaired cartilage from BMS is known to be unlike that of hyaline cartilage and its inner endurance is not guaranteed. The reason presumably came from a shortage of cartilage-forming cells in blood clots derived by BMS. In order to increase repairable cellularity, the feasibility of autologous bone marrow-derived buffy coat transplantation in repair of large full-thickness cartilage defects was investigated in this study.MethodsRabbits were divided into four groups: the defect remained untreated as a negative control; performance of BMS only (BMS group); BMS followed by supplementation of autologous bone marrow buffy coat (Buffy coat group); transplantation of autologous osteochondral transplantation (AOTS) as a positive control.ResultsRepair of cartilage defects in the Buffy coat group in a rabbit model was more effective than BMS alone and similar to AOTS. Gross findings, histological analysis, histological scoring, immunohistochemistry, and chemical assay demonstrated that supplementation of autologous bone marrow buffy coat after BMS arthroplasty effectively repaired cartilage defects in a rabbit model, and was more effective than BMS arthroplasty alone.ConclusionSupplementation of autologous bone marrow-derived buffy coat in cases of BMS could be a useful clinical protocol for cartilage repair

    Electroactive biofilms: new means for electrochemistry

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    This work demonstrates that electrochemical reactions can be catalysed by the natural biofilms that form on electrode surfaces dipping into drinking water or compost. In drinking water, oxygen reduction was monitored with stainless steel ultra-microelectrodes under constant potential electrolysis at )0.30 V/SCE for 13 days. 16 independent experiments were conducted in drinking water, either pure or with the addition of acetate or dextrose. In most cases, the current increased and reached 1.5–9.5 times the initial current. The current increase was attributed to biofilm forming on the electrode in a similar way to that has been observed in seawater. Epifluorescence microscopy showed that the bacteria size and the biofilm morphology depended on the nutrients added, but no quantitative correlation between biofilm morphology and current was established. In compost, the oxidation process was investigated using a titanium based electrode under constant polarisation in the range 0.10–0.70 V/SCE. It was demonstrated that the indigenous micro-organisms were responsible for the current increase observed after a few days, up to 60 mA m)2. Adding 10 mM acetate to the compost amplified the current density to 145 mA m)2 at 0.50 V/SCE. The study suggests that many natural environments, other than marine sediments, waste waters and seawaters that have been predominantly investigated until now, may be able to produce electrochemically active biofilm

    Room temperature ferromagnetism in chemically synthesized ZnO rods

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    We report structural and magnetic properties of pure ZnO rods using X-ray diffraction (XRD), magnetization hysteresis (M-H) loop and near edge x-ray fine structure spectroscopy (NEXAFS) study at O K edge. Sample of ZnO was prepared by co-precipitation method. XRD and selective area electron diffraction measurements infer that ZnO rods exhibit a single phase polycrystalline nature with wurtzite lattice. Field emission transmission electron microscopy, field emission scanning electron microscopy micrographs infers that ZnO have rod type microstructures with dimension 200 nm in diameter and 550 nm in length. M-H loop studies performed at room temperature display room temperature ferromagnetism in ZnO rods. NEXAFS study reflects absence of the oxygen vacancies in pure ZnO rods.Comment: 8 Pages, 3 Figure
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