Structure‑H Methane + 1,1,2,2,3,3,4-Heptafluorocyclopentane Mixed Hydrate at Pressures up to 373 MPa

Thermodynamic stability boundary of structure-H hydrates with large guest species and methane (CH₄) at extremely high pressures has been almost unclear. In the present study, the four-phase equilibrium relations in the structure-H CH₄ + 1,1,2,2,3,3,4-heptafluorocyclopentane (1,1,2,2,3,3,4-HFCP) mixed hydrate system were investigated in a temperature range of (281.05 to 330.12) K and a pressure range up to 373 MPa. The difference between equilibrium pressures in the structure-H CH₄ + 1,1,2,2,3,3,4-HFCP mixed hydrate system and the structure-I simple CH₄ hydrate system gets larger with increase in temperature. The structure-H CH₄ + 1,1,2,2,3,3,4-HFCP mixed hydrate survives even at 330 K and 373 MPa without any structural phase transition. The maximum temperature where the structure-H CH₄ + 1,1,2,2,3,3,4-HFCP mixed hydrate is thermodynamically stable is likely to be beyond that of the structure-H simple CH₄ hydrate

Heterogeneously Catalyzed Aerobic Oxidation of Sulfides with a BaRuO₃ Nanoperovskite

A rhombohedral BaRuO₃ nanoperovskite, which was synthesized by the sol–gel method using malic acid, could act as an efficient heterogeneous catalyst for the selective oxidation of various aromatic and aliphatic sulfides with molecular oxygen as the sole oxidant. BaRuO₃ showed much higher catalytic activities than other catalysts, including ruthenium-based perovskite oxides, under mild reaction conditions. The catalyst could be recovered by simple filtration and reused several times without obvious loss of its high catalytic performance. The catalyst effect, ¹⁸O-labeling experiments, and kinetic and mechanistic studies showed that substrate oxidation proceeds with oxygen species caused by the solid. The crystal structure of ruthenium-based oxides is crucial to control the nature of the oxygen atoms and significantly affects their oxygen transfer reactivity. Density functional theory calculations revealed that the face-sharing octahedra in BaRuO₃ likely are possible active sites in the present oxidation in sharp contrast to the corner-sharing octahedra in SrRuO₃, CaRuO₃, and RuO₂. The superior oxygen transfer ability of BaRuO₃ is also applicable to the quantitative conversion of dibenzothiophene into the corresponding sulfone and gram-scale oxidation of 4-methoxy thioanisole, in which 1.20 g (71% yield) of the analytically pure sulfoxide could be isolated

High-Pressure Phase Equilibrium and Raman Spectroscopic Studies on the 1,1-Difluoroethane (HFC-152a) Hydrate System

High-pressure phase equilibrium relations of the 1,1-difluoroethane (HFC-152a) + water binary system were investigated in a temperature range of (275.03 to 319.30) K and a pressure range up to 370 MPa. Four three-phase coexisting curves of hydrate + aqueous + gas phases, hydrate + HFC-152a-rich liquid + gas phases, hydrate + aqueous + HFC-152a-rich liquid phases, and aqueous + HFC-152a-rich liquid + gas phases originate from the quadruple point of hydrate + aqueous + HFC-152a-rich liquid HFC-152a + gas phases located at (288.05 ± 0.15) K and (0.44 ± 0.01) MPa. The structure of HFC-152a hydrate remains structure I (s-I) in the pressure range up to 370 MPa. Raman spectra of the HFC-152a molecule in the HFC-152a hydrate indicate that the HFC-152a molecules occupy only large cages of s-I HFC-152a hydrate in the presence of completely vacant small cages at a pressure up to 370 MPa

Investigating the Thermodynamic Stabilities of Hydrogen and Methane Binary Gas Hydrates

When hydrogen (H₂) is mixed with small amounts of methane (CH₄), the conditions required for clathrate hydrate formation can be significantly reduced when compared to that of simple H₂ hydrate. With growing demand for CH₄ as a commercially viable source of energy, H₂+ CH₄ binary hydrates may be more appealing than extensively studied H₂ + tetrahydrofuran (THF) hydrates from an energy density standpoint. Using Raman spectroscopic and powder X-ray diffraction measurements, we show that hydrate structure and storage capacities of H₂ + CH₄ mixed hydrates are largely dependent on the composition of the initial gas mixture, total system pressure, and formation period. In some cases, H₂ + CH₄ hydrate kinetically forms structure I first, even though the thermodynamically stable phase is structure II

Genes Responsive to Low-Intensity Pulsed Ultrasound in MC3T3-E1 Preosteoblast Cells

Although low-intensity pulsed ultrasound (LIPUS) has been shown to enhance bone fracture healing, the underlying mechanism of LIPUS remains to be fully elucidated. Here, to better understand the molecular mechanism underlying cellular responses to LIPUS, we investigated gene expression profiles in mouse MC3T3-E1 preosteoblast cells exposed to LIPUS using high-density oligonucleotide microarrays and computational gene expression analysis tools. Although treatment of the cells with a single 20-min LIPUS (1.5 MHz, 30 mW/cm2) did not affect the cell growth or alkaline phosphatase activity, the treatment significantly increased the mRNA level of Bglap. Microarray analysis demonstrated that 38 genes were upregulated and 37 genes were downregulated by 1.5-fold or more in the cells at 24-h post-treatment. Ingenuity pathway analysis demonstrated that the gene network U (up) contained many upregulated genes that were mainly associated with bone morphology in the category of biological functions of skeletal and muscular system development and function. Moreover, the biological function of the gene network D (down), which contained downregulated genes, was associated with gene expression, the cell cycle and connective tissue development and function. These results should help to further clarify the molecular basis of the mechanisms of the LIPUS response in osteoblast cells

ILC Reference Design Report Volume 1 - Executive Summary

The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2s^-1. This report is the Executive Summary (Volume I) of the four volume Reference Design Report. It gives an overview of the physics at the ILC, the accelerator design and value estimate, the detector concepts, and the next steps towards project realization.The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2s^-1. This report is the Executive Summary (Volume I) of the four volume Reference Design Report. It gives an overview of the physics at the ILC, the accelerator design and value estimate, the detector concepts, and the next steps towards project realization