Hydrostatic Compression Effects on Fifth-Group Element Superconductors V, Nb, and Ta Subjected to High-Pressure Torsion

In fifth-group element superconductors V, Nb, and Ta, the increase in superconducting transition temperature (Tc) was attempted by using both high-pressure torsion (HPT) and additional hydrostatic pressure (HP) compression. The former brings about the grain refinement and strain accumulation in the unit-cell level. The additional compression for severely strained superconductors triggers strengthening intergrain-contact and/or structural deformation in the unit-cell level. The manner of the appearance of the above two effects depends on the kind of elements: First, in V, there is no prominent effect of HPT, comparing to the hydrostatic compression effects on its non-strained material. Next, in Ta, the effect of strengthening intergrain-contact appears at small hydrostatic compression, resulting in temporal increase in Tc. Finally, Nb exhibits prominent increase in Tc by both effects and, in particular, the structural deformation in the unit-cell level promotes the increase in Tc. Thus, the accumulation of residual strain in the level of starting material can be a promising work to manipulate Tc under HP compression

Relationship between Protection against Cold and the Physiological Index during a Cold Environment

A snow cave is a bivouac shelter used in mountain climbing that is widely used as a shelter against the cold during winter. In the outdoors, wind velocity and air temperature have an influence on temperature change. It could stabilize body temperature if it can control the convection of ambient air. This paper could develop a theory focusing on the relation between physiological indexes and the protection against the cold while staying in a snow cave. For example, protection against the cold could be thermal insulation underwear, thermal insulation gloves, thermal insulation socks, a steam warmed temperature sheet and a rescue sheet. Measurement items were heart rate, blood pressure, rectal temperature, score of a subjective thermal sensation and the activity of the parasympathetic nervous system. It was clarified that the protection against the cold could be effective for the decrease of the physiological index. These field studies suggest that they would enable the adaptation in the adjustment range of the autonomic nervous system given these protections against the cold

シンポジウム報告 日本の管弦楽作品の演奏譜に於ける課題と展望 : 演奏譜は文化だ!

シンポジウム主催：東京音楽大学付属図書館、オーケストラ・ニッポニカ開催日時：2013年12月7日　（東京音楽大学付属図書館5階）総合司会：林淑姫内容：経過報告「オーケストラ・ニッポニカ十年の活動の中で考えたこと、感じたこと」 / 加藤のぞみ発表日本人作品演奏と演奏譜――「オーケストラ・ニッポニカ・アーカイヴ」の意義 / 小沼純一神戸女学院大学「大澤壽人プロジェクト」について / 生島美紀子日本人作品上演と楽譜の所在――オーケストラ・ライブラリアン会議での討議から / 沖あかね全音レンタル楽譜事業と課題 / 高木雅也オーケストラ・ニッポニカの経験から / 奥平

The effects of endangered freshwater pearl mussels on channel morphology and flow in a low-gradient sandy river

Conservation of ecosystem engineers, which modulates the surrounding habitat by causing physical state changes in biotic or abiotic materials, is important for maintaining the functional integrity of ecosystems. This study examined the effects of endangered freshwater pearl mussels (Margaritifera laevis and M. togakushiensis) on channel morphology and flow in a low-gradient sandy river. For this, we performed a field removal experiment of mussels using three treatments in twelve 10-m reaches. Mussel abundance and biomass, and three physical variables were measured before, immediately after, and two months to one year after the treatments. Mussel removal resulted in channel degradation with a 60% increase in flow depth, a 30% decrease in current velocity, and a 50% reduction in the width-to-depth ratio two months after the treatments, whereas minimal changes were measured in reaches with mussels. The results indicated that pearl mussels act as an ecosystem engineer affecting the channel morphology and flow of sandy rivers. The conservation of the pearl mussel populations is key to preserving their far-reaching benefits in ecosystem integrity including habitats for other various organisms

A Theoretical Study of an Unusual Y-Shaped Three-Coordinate Pt Complex: Pt(0) σ-Disilane Complex or Pt(II) Disilyl Complex?

The unusual Y-shaped structure of the recently reported three-coordinate Pt complex Pt­[NHC­(Dip)₂]­(SiMe₂Ph)₂ (NHC = N-heterocyclic carbene; Dip = 2,6-diisopropylphenyl) was considered a snapshot of the reductive elimination of disilane. A density functional theory study indicates that this structure arises from the strong trans influence of the extremely σ-donating carbene and silyl ligands. Though this complex can be understood to be a Pt­(II) disilyl complex bearing a distorted geometry due to the Jahn–Teller effect, its ¹⁹⁵Pt NMR chemical shift is considerably different from those of Pt­(II) complexes but close to those of typical Pt(0) complexes. Its Si···Si bonding interaction is ∼50% of the usual energy of a Si–Si single bond. The interaction between the Pt center and the (SiMe₂Ph)₂ moiety can be understood in terms of donation and back-donation interactions of the Si–Si σ-bonding and σ*-antibonding molecular orbitals with the Pt center. Thus, we conclude that this is likely a Pt(0) σ-disilane complex and thus a snapshot after a considerable amount of the charge transfer from disilane to the Pt center has occurred. Phenyl anion (Ph^–) and [R–Ar]⁻ [R–Ar = 2,6-(2,6-<i>i</i>Pr₂C₆H₃)₂C₆H₃] as well as the divalent carbon(0) ligand C­(NHC)₂ also provide similar unusual Y-shaped structures. Three-coordinate digermyl, diboryl, and silyl–boryl complexes of Pt and a disilyl complex of Pd are theoretically predicted to have similar unusual Y-shaped structures when a strongly donating ligand coordinates to the metal center. In a trigonal-bipyramidal Ir disilyl complex [Ir{NHC(Dip)₂}(PH₃)₂(SiMe₃)₂]⁺, the equatorial plane has a similar unusual Y-shaped structure. These results suggest that various snapshots can be shown for the reductive eliminations of the Ge–Ge, B–B, and B–Si σ-bonds

Theoretical Study of Reactivity of Ge(II)-hydride Compound: Comparison with Rh(I)-Hydride Complex and Prediction of Full Catalytic Cycle by Ge(II)-hydride

The reaction of a Ge­(II) hydride compound HC­{CMeArN}₂GeH (Ar = 2,6-<i>i</i>Pr₂C₆H₃) <b>1</b> with 2,2,2-trifluoroacetophenone (CF₃PhCO) is theoretically investigated with density functional theory and spin-component-scaled second-order Møller–Plesset methods. This reaction easily occurs with moderate activation barrier and considerably large exothermicity, to afford a Ge­(II) alkoxide <b>2</b> through a four-membered transition state. In the transition state, the charge transfer from the Ge–H σ-bonding molecular orbital (MO) to the CO π*-antibonding MO of CF₃PhCO plays an important role. Acetone ((CH₃)₂CO) and benzophenone (Ph₂CO) are not reactive for <b>1</b>, because their π*-antibonding MOs exist at higher energy than that of CF₃PhCO. Though <b>2</b> is easily formed, the catalytic hydrogenation of CF₃PhCO by <b>1</b> is difficult because the reaction of <b>2</b> with a dihydrogen molecule needs a large activation energy. On the other hand, our calculations clearly show that the catalytic hydrogenation of ketone by <i>cis</i>-RhH­(PPh₃)₂ <b>4</b> easily occurs, as expected. The comparison of catalytic cycle between <b>1</b> and <b>4</b> suggests that the strong Ge–O bond of <b>2</b> is the reason of the very large activation energy for the hydrogenation by <b>1</b>. To overcome this defect, we investigated various reagents and found that the catalytic cycle can be completed with the use of SiF₃H. The product is silylether CF₃PhCHOSiF₃, which is equivalent to alcohol because it easily undergoes hydrolysis to afford CF₃PhCHOH. The similar catalytic cycles are also theoretically predicted for hydrosilylations of CO₂ and imine. This is the first theoretical prediction of the full catalytic cycle with a heavier main-group element compound

Field survey of air conditioner temperature settings in a hot, dry climate (Oman)

In conventional air-conditioning design, the comfortable range of temperatures is between 25°C and 27°C with relative humidity levels of 40% to 60%; these numbers vary only slightly based on a person's race and country. Several studies in tropical climates show that the observed thermal comfort requirement often does not agree with those obtained based on experiments, which have mainly used North American subjects. However, there is no consistent rationale that explains why comfort requirements are different in hot climates, suggesting that more surveys on thermal comfort may be needed in the tropics. In Asia, there has recently been a rapid and widespread diffusion of air conditioners; therefore, a survey was conducted to clarify what temperature and humidity level people in Asian countries prefer in order to feel comfortable. Following that research, this article presents the results of a questionnaire survey on the use of air conditioners in houses in hot, dry climates. Nizwa and Rustak, Oman, characterized by the hot, arid climate of the Arabian Peninsula, were chosen as survey areas. The questionnaire survey was distributed to students of Nizwa University. Questions were asked about the duration of air-conditioner use and preferred air-conditioner temperature settings. To determine how respondents felt about their indoor environment, questions were also asked about the thermal sensations that were experienced while using the air conditioner. In both cities, the mean operating time of the air conditioner was very long. The respondents reported selecting a low temperature setting while sleeping, despite the fact that many of them reported that they were cold while sleeping. Ninety percent of respondents reported a cold, cool, or neutral thermal sensation while using the air conditioner without feeling discomfort