Close-Packed Silicon Lens Antennas for Millimeter-Wave MKID Camera

We have been developing a large-format millimeter-wave camera based on lens-antenna-coupled microwave kinetic inductance detectors (MKIDs) for a planned telescope at Dome Fuji (3810 m a.s.l.), Antarctica. Optical coupling to the MKID incorporates double-slot antennas and a silicon lens array. To realize a large-format camera ( \(>\) 10,000 pixels), a highly integrated small-diameter lens array and fast optics are required. Lens diameters of 1.2, 2, and 3 times the target wavelength are investigated for the main beam symmetry, side-lobe level, cross-polarization level, and bandwidth, considering the effects of the surrounding lenses. In this study, we present the simulated beam pattern profiles of close-packed lens antenna and the effect of misalignment between the silicon lens and double-slot antenna. We also show the evaluations of the developed 721-pixel close-packed silicon lens array.     

Inward Migration of Glass‐Modifier Cations During Heat Treatment Under an N2 Atmosphere

An Na⁺/Ca²⁺‐deficient layer is observed to form on the glass surface region up to a depth of hundreds of nanometers when a soda‐lime‐silicate glass is heat treated under an N₂ atmosphere near its glass‐transition temperature. The measurements were performed using X‐ray photoelectron spectroscopy with C₆₀‐ion sputtering (C₆₀‐XPS) and dynamic secondary‐ion mass spectrometry (D‐SIMS) with consideration of the mass and charge balances. The increase in the amount of hydrogen is substantially less than the decrease in the total charge due to the loss of modifier cations in the Na⁺/Ca²⁺‐deficient layer; furthermore, the oxygen concentration in this layer is lower than the bulk value, suggesting that the silanol groups in the surface layer of the glass are dehydrated. A high‐concentration layer of Ca²⁺ is also confirmed in the dehydration layer of the glass heat treated under an N₂ atmosphere, suggesting that Na⁺ and Ca²⁺ ions migrate inward into the glass via an ion‐exchange reaction with protons, which migrate toward the surface from the bulk. We also confirmed that a thicker Na⁺/Ca²⁺‐deficient layer is formed on glass surfaces with higher water content. Our results suggest that the dehydration of the silanol groups is the driving force of the inward migration of Na⁺ and Ca²⁺ ions.     

Medium‐chain fatty acids – Nutritional function and application to cooking oil

Medium‐chain fatty acids, which are saturated fatty acids composed of 8–10 carbons, have unique nutritional characteristics different from those of long‐chain fatty acids. Medium‐chain triacylglycerol (MCT) is more readily digested and absorbed than long‐chain triacylglycerol (LCT), and easily utilized as energy. The use of MCT as an edible oil is limited because it has a low smoking point and easily foams during deep‐frying like lauric acid does. Medium‐ and long‐chain triacylglycerol (MLCT) prepared by transesterification between MCT and LCT has a higher smoking point and reduced foaming property. MLCT oil has been shown to result in less body fat accumulation in animal and human studies. It has been approved as a food for specified health use (FOSHU) and widely sold in Japan as a cooking oil less likely to lead to body fat accumulation.     

带脱层的复合材料层板的屈曲分析

用基于Mindlin 板理论的有限元方法进行了带脱层损伤的复合材料层板的屈曲载荷分析。为了获得物理上可能的屈曲模态, 即避免上下脱层的相互贯穿, 在接触区域引入一些假想弹簧, 并给出了这些假想弹簧刚度系数的计算公式和接触计算的迭代格式, 通过这些弹簧对原始刚度矩阵进行修正可以有效地求解屈曲载荷特征值分析中的接触问题。数值计算结果表明了本算法的有效性和引入接触分析对这类屈曲分析的重要性。同时, 还对脱层的大小、形状、位置和脱层的纤维铺层方向对屈曲载荷的影响进行了研究。      

Enhanced hydrogen production by a mutant of Rhodobacter sphaeroides having an altered light-harvesting system

A stable mutant of the photosynthetic bacterium Rhodobacter sphaeroides with an altered light-harvesting (LH) system (P3 mutant) was obtained by UV irradiation and characterized. The mutant exhibited a 2.7-fold decrease in the core antennal (LH1) content and 1.6-fold increase in peripheral antennal (LH2) content compared to the wild-type strain. The H2 evolution rates in the P3 mutant under 800- and 850-nm light, corresponding to the absorption maxima of LH2, were 1.5 times higher than in the wild-type strain. The wild-type absorption spectrum was restored in the P3 mutant when a 1.1-kb PCR-amplified fragment containing the puf promoter and pufQBA genes was ligated into a pRK-415 derivative and introduced into it. The transformant showed lower H2 production rates at 800 and 850 nm than the P3 strain carrying the control plasmid, indicating that the accelerated H2 production in the P3 mutant was a result of alterations in the LH system.     

Effects of Heating,Vacuum Drying and Steeping on Gelatinization Properties and Dynamic Viscoelasticity of Various Starches

Starches having A‐ and B‐type X‐ray diffraction patterns (A‐ and B‐type starches) were modified by heating at 120 °C for 2 h (HT), vacuum drying at room temperature for 20 h (VD) and steeping at 50 °C for 20 h (ST). The properties of starches were compared using differential scanning calorimetry (DSC) and dynamic viscoelasticity behavior during heat processing (G' behavior). As observed by DSC, HT rarely changed the gelatinization properties for A‐type starches, but decreased the gelatinization temperatures and enthalpies (ΔH) for B‐type starches. A shift of the X‐ray diffractograms from B‐type to A‐type patterns was not detected after HT. Similar changes in gelatinization properties were observed for B‐type starches after VD. ST increased the gelatinization temperatures and also narrowed the gelatinization temperature range irrespective of crystal type. Both HT and VD decreased the peak temperature (T_p) in G' behavior and increased the peak G' value for B‐type starches. ST increased T_p and also decreased the peak G' value irrespective of starch crystal type. G' values after reaching T_p — which indicate the viscoelasticity of the swollen starch granules without breakdown — showed significant increases only for B‐type starches after HT.     

Disease Outcome and Brain Metabolomics of Cyclophilin-D Knockout Mice in Sepsis

Sepsis-associated encephalopathy (SAE) is a diffuse brain dysfunction resulting from a systemic inflammatory response to infection, but the mechanism remains unclear. The mitochondrial permeability transition pore (MPTP) could play a central role in the neuronal dysfunction, induction of apoptosis, and cell death in SAE. The mitochondrial isomerase cyclophilin D (CypD) is known to control the sensitivity of MPTP induction. We, therefore, established a cecal ligation and puncture (CLP) model, which is the gold standard in sepsis research, using CypD knockout (CypD KO) mice, and analyzed the disease phenotype and the possible molecular mechanism of SAE through metabolomic analyses of brain tissue. A comparison of adult, male wild-type, and CypD KO mice demonstrated statistically significant differences in body temperature, mortality, and histological changes. In the metabolomic analysis, the main finding was the maintenance of reduced glutathione (GSH) levels and the reduced glutathione/oxidized glutathione (GSH/GSSG) ratio in the KO animals following CLP. In conclusion, we demonstrate that CypD is implicated in the pathogenesis of SAE, possibly related to the inhibition of MPTP induction and, as a consequence, the decreased production of ROS and other free radicals, thereby protecting mitochondrial and cellular function.