Collective resonance modes of Josephson vortices in sandwiched stack of Bi2_{2}Sr2_{2}CaCu2_{2}O8+x_{8+x} intrinsic Josephson junctions

We observed splitting of the low-bias vortex-flow branch in a dense-Josephson-vortex state into multiple sub-branches in current-voltage characteristics of intrinsic Josephson junctions (IJJs) of Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+x}$ single crystals in the long-junction limit. Each sub-branch corresponds to a plasma mode in serially coupled Josephson junctions. Splitting into low-bias linear sub-branches with a spread in the slopes and the inter-sub-branch mode-switching character are in good quantitative agreement with the prediction of the weak but finite inter-junction capacitive-coupling model incorporated with the inductive coupling. This suggests the importance of the role of the capacitive coupling in accurately describing the vortex dynamics in serially stacked IJJs.Comment: 4 pages, 3 figures, 1 tabl

Development of Ruthenium-Based Catalysts for Oxygen Reduction Reaction

A process was developed to synthesize ruthenium-based chelate (RuNx) electrocatalysts for the oxygen reduction reaction, using RuCl3 and propylene diammine as the Ru and N precursors, respectively. High-temperature pyrolysis has a critical role in the formation of the catalytic Ru–N sites for oxygen reduction. The RuNx catalyst modified in the presence of nitrogen-containing organic exhibited comparable catalytic activity and selectivity for oxygen reduction to the carbon-supported Pt catalyst in acidic media. The catalyst generates less than 2% hydrogen peroxide during oxygen reduction

Gravitational Wave Spectrum in Inflation with Nonclassical States

The initial quantum state during inflation may evolve to a highly squeezed quantum state due to the amplification of the time-dependent parameter, $\omega_{phys}(k/a)$, which may be the modified dispersion relation in trans-Planckian physics. This squeezed quantum state is a nonclassical state that has no counterpart in the classical theory. We have considered the nonclassical states such as squeezed, squeezed coherent, and squeezed thermal states, and calculated the power spectrum of the gravitational wave perturbation when the mode leaves the horizon.Comment: 21 page

Comments on AdS2 solutions of D=11 Supergravity

We study the supersymmetric solutions of 11-dimensional supergravity with a factor of $AdS_2$ made of M2-branes. Such solutions can provide gravity duals of superconformal quantum mechanics, or through double Wick rotation, the generic bubbling geometry of M-theory which are 1/16-BPS. We show that, when the internal manifold is compact, it should take the form of a warped U(1)-fibration over an 8-dimensional Kahler space.Comment: 11 pages, no figure, JHEP3.cl

Optimizing Energetic Light Dark Matter Searches in Dark Matter and Neutrino Experiments

Neutrino and dark matter experiments with large-volume ($\gtrsim 1$ ton) detectors can provide excellent sensitivity to signals induced by energetic light dark matter coming from the present universe. Taking boosted dark matter as a concrete example of energetic light dark matter, we scrutinize two representative search channels, electron scattering and proton scattering including deep inelastic scattering processes, in the context of elastic and inelastic boosted dark matter, in a completely detector-independent manner. In this work, a dark gauge boson is adopted as the particle to mediate the interactions between the Standard Model particles and boosted dark matter. We find that the signal sensitivity of the two channels highly depends on the (mass-)parameter region to probe, so search strategies and channels should be designed sensibly especially at the earlier stage of experiments. In particular, the contribution from the boosted-dark-matter-initiated deep inelastic scattering can be subleading (important) compared to the quasi-elastic proton scattering, if the mass of the mediator is below (above) $\mathcal{O}$(GeV). We demonstrate how to practically perform searches and relevant analyses, employing example detectors such as DarkSide-20k, DUNE, Hyper-Kamiokande, and DeepCore, with their respective detector specifications taken into consideration. For other potential detectors we provide a summary table, collecting relevant information, from which similar studies can be fulfilled readily.Comment: 47 pages, 9 figures, 3 tables, Journal submission versio

Effect of Cutting Height on Productivity and Quality of Alfalfa in Northern Area of Korea

Alfalfa is a very important forage for livestock feeding. In particular, due to the high crude protein content, it is widely used as a dairy cattle feeds. However, the cultivation of alfalfa is quite limited and main source is imported hay in Korea. There are many reasons, but most importantly, low productivity due to lack of boron in the soil. This experiment was conducted to expand domestic production and use of alfalfa. Alfalfa was sown in the fall of 2018 at 30 kg/ha seeding rate. Alfalfa was harvested four times (3 May, 2 July, 11 September and 13 October) in 2019 with three different cutting height (5, 15 and 25 cm of stubble height) and investigate productivity, quality and regrowth. The plant height was the highest at the 3rd harvest (108 cm) and the dry matter content was the highest at the 1st harvest (28.78 %). The yield of fresh and dry matter was the highest at the first. Annual fresh and DM productivity was significantly higher in 5cm cutting height. CP was highest at the 4th harvest and lowest at the 3rd. The higher the cutting height, the higher CP content. ADF and NDF contents decreased significantly with increasing cutting height (p\u3c 0.05). TDN content was highest at the 4th harvest and lowest at the 3rd harvest. It was also found that the higher the cutting height, the higher the TDN content. The relative feed value (RFV) of alfalfa was highest at the 4th fourth harvest (mean 164) and lowest at the 3rd harvest (mean 85). The RFV value increased with increasing cutting height and 25 cm cutting height plot was 152. Regrowth after cutting was good at 15cm and 25cm height and 5cm treatment was slightly lower. In conclusion, the possibility of alfalfa production in Korea is sufficient and a cutting height of 5 cm or more is recommended and requires constant observation

Effect of Seeding Rates on Productivity and Quality of Alfalfa in Northern Area of Korea

Alfalfa cultivation in South Korea is not common. There are many reasons, but low productivity has been extremely limited. Although alfalfa growth was poor due to boron deficiency in the soil, the problem has recently been solved. Nevertheless, the cultivation of alfalfa is not expanding. About 200,000 tonnes of alfalfa hay are imported every year. Therefore, this study was conducted to find a way to replace imported hay by expanding alfalfa cultivation in Korea. Alfalfa (P5444) was sown in northern part of South Korea (Pyeongchang). Alfalfa was sown in September 2018 with different seeding rates (20, 30 and 40 kg/ha) and harvested four times in 2019 (3 May, 2 July, 11 September and 13 October). The plant height was the highest at the 3rd harvest (113 cm) and the dry matter content was the highest at the 1st harvest (27.89 %). The yield of fresh and dry matter was the highest at the first harvest (mean 6,856 kg/ha). Annual fresh and DM productivity was significantly higher in 40 kg/ha seeding rates (89,833 and 20,265 kg/ha). Crude protein (CP) content in forage quality was higher than 27% at the 4th harvest and the lowest by 13% at the 3rd harvest. Crude protein, ADF and NDF contents did not show significant difference (P\u3e 0.05) according to the increase of seeding rate. TDN content of alfalfa was not significantly different among treatments (P \u3e 0.05), but was highest at the 4th harvest (66.98 %) and lowest at the 3rd harvest (44.44 %). The relative feed value (RFV) of alfalfa was highest at the 4th fourth harvest (mean 146) and lowest at the 3rd harvest (mean 83). However, there was no significant difference among the seeding rates (average 120). In conclusion, the possibility of alfalfa production in Korea is sufficient and 40 kg/ha seeding rate is recommended