Critical currents for vortex defect motion in superconducting arrays

We study numerically the motion of vortices in two-dimensional arrays of resistively shunted Josephson junctions. An extra vortex is created in the ground states by introducing novel boundary conditions and made mobile by applying external currents. We then measure critical currents and the corresponding pinning energy barriers to vortex motion, which in the unfrustrated case agree well with previous theoretical and experimental findings. In the fully frustrated case our results also give good agreement with experimental ones, in sharp contrast with the existing theoretical prediction. A physical explanation is provided in relation with the vortex motion observed in simulations.Comment: To appear in Physical Review

A Case Report of Painless Moving Toes Syndrome

This is the first report of a case of painless moving toes syndrome with radiculopathy. The patient presented with bilateral painless moving toes and unilateral subclinical sacral (S1) radiculopathy. Bilateral movements with the unilateral lesion, and fluctuation with postural changes and distant muscle contraction suggest that the underlying pathomechanism was a central reorganization in the spinal level

Ruthenium anchored on carbon nanotube electrocatalyst for hydrogen production with enhanced Faradaic efficiency

Developing efficient and stable electrocatalysts is crucial for the electrochemical production of pure and clean hydrogen. For practical applications, an economical and facile method of producing catalysts for the hydrogen evolution reaction (HER) is essential. Here, we report ruthenium (Ru) nanoparticles uniformly deposited on multi-walled carbon nanotubes (MWCNTs) as an efficient HER catalyst. The catalyst exhibits the small overpotentials of 13 and 17 mV at a current density of 10 mA cm(-2) in 0.5M aq. H2SO4 and 1.0M aq. KOH, respectively, surpassing the commercial Pt/C (16 mV and 33 mV). Moreover, the catalyst has excellent stability in both media, showing almost "zeroloss" during cycling. In a real device, the catalyst produces 15.4% more hydrogen per power consumed, and shows a higher Faradaic efficiency (92.28%) than the benchmark Pt/C (85.97%). Density functional theory calculations suggest that Ru-C bonding is the most plausible active site for the HER

Dynamic transition and Shapiro-step melting in a frustrated Josephson-junction array

We consider a two-dimensional fully frustrated Josephson-junction array driven by combined direct and alternating currents. Interplay between the mode locking phenomenon, manifested by giant Shapiro steps in the current-voltage characteristics, and the dynamic phase transition is investigated at finite temperatures. Melting of Shapiro steps due to thermal fluctuations is shown to be accompanied by the dynamic phase transition, the universality class of which is also discussed

SubrenaI CapsuIe Tumor ImpIant Assay with Frozen Tumor Tissue: A Preliminary Study Using Mouse Sareoma and Human Uterine Cervix Cancer

The purpose of this study is to evaluate the possibility of application of SHeA to previously frozen tumor tissue. Mouse sarcoma-I80 and human squamous cell carcinoma of the uterine cervix were used as implanting tumor specimens. The fresh tumor specimens were frozen by rapid freezing method and stored in a liquid nitrogen tank. On the 7th day of freezing, the specimens were thawed and diced into 1 cubic millimeter pieces, and implanted beneath the subrenal capsule of ICH mice. The average viabilities before freezing and after thawing were 86.7% and 10.5% in mouse sarcoma-I80 respectively. And those of human uterine cervix cancer were 73.3% and 9.5% respectively. The evaluability of implanted tumor was 83.3% on the 6th day and 73.7% on the 12th day in mouse sarcoma, and in human cervix cancer, 75.0% and 66.7% respectively. The growth of previously frozen implanted mouse sarcoma was significant, 2.1 times on the 6th day and 73.9 times on the 12th day in volume. In the case of cervix cancer, the previously frozen tumor implants also grew significantly, 1.7 times on the 6th day and 2.1 times on the 12th day in volume. In conclusion, this preliminary laboratory study showed that SHCA could be applied to frozen tumor tissue as well as to fresh tissue for chemosensitivity test

Dissociating stable nitrogen molecules under mild conditions by cyclic strain engineering

All quiet on the nitrogen front. The dissociation of stable diatomic nitrogen molecules (N-2) is one of the most challenging tasks in the scientific community and currently requires both high pressure and high temperature. Here, we demonstrate that N-2 can be dissociated under mild conditions by cyclic strain engineering. The method can be performed at a critical reaction pressure of less than 1 bar, and the temperature of the reaction container is only 40 degrees C. When graphite was used as a dissociated N* receptor, the normalized loading of N to C reached as high as 16.3 at/at %. Such efficient nitrogen dissociation is induced by the cyclic loading and unloading mechanical strain, which has the effect of altering the binding energy of N, facilitating adsorption in the strain-free stage and desorption in the compressive strain stage. Our finding may lead to opportunities for the direct synthesis of N-containing compounds from N-2

Availability of hairy vetch (Vicia villosa Roth) as leguminous green manure crops for organic rice in reclaimed saline land

Hairy vetch (Vicia villosa) is playing an important role to improve soil physical properties and soil fertility for the supply of crop nutrients and this crop is also used as a representative legumes green manure for the production of organic agricultural food. In this study we evaluated the availability of hairy vetch in reclaimed organic rice cultivation. The response to increasing salinity was analyzed by means of the germination rate and seedling growth of hairy vetch. Results showed that seed germination of hairy vetch decreased insignificantly up to concentration of 0.6% NaCl. However, shoot and root growth of hairy vetch showed significant reduction at salinity concentrations higher than 0.1% NaCl level. In these results we were considered that hairy vetch can be use under concentration of 0.1% salinity as green manure for reclaimed saline agriculture

Evaluation of beach response due to construction of submerged detached breakwater

Submerged detached breakwaters (SDBWs) have increasingly been used in recent times as an alternative against their emergent counterpart (EDBWs) to mitigate erosion because the former do not spoil the seascape. Both of these structures are (usually) constructed using precast concrete blocks or natural granite rocks, hence becoming permeable structures. For an EDBW, a parabolic bay shape equation can be readily used to estimate the planar shape of the shoreline behind the structure, but there is still no approach to estimate how the shoreline behind the SDBW is formed. In this study, we estimated how the shoreline is balanced by examining how the dominant wave direction changes due to the diffraction of the transmitted wave generated after the installation of the SDBW from the long-term wave directional spectrum. The change in dominant wave direction was determined under the shoreline gradient condition where littoral drift does not occur, considering the diffraction phenomenon due to the difference in transmitted waves. This means that the shape of the equilibrium shoreline changes to face perpendicular to the dominant wave direction. As a meaningful result, when the transmittance is 0, it converges to the well-known empirical equation of EDBW. The present methodology is validated by comparing the observed data (wave and shoreline change) from two beaches (Anmok and Bongpo-Cheonjin Beaches) on the eastern coast of Korea. This rational approach to shoreline changes behind permeable SDBWs will help in proactive review work for coastal management as well as beach erosion mitigation