The thermodynamic stabilities of semiclathrate hydrates were investigated in the tetra-n-butyl ammonium chloride (TBAC) aqueous solution (mole fraction TBAC is 0.0323) + H2, N2, CH4, CO2, and C2H6 systems. dissociation temperature each hydrate higher than that simple (hydration number 30) except for C2H6-containing system whole pressure region under present experimental conditions. Isobaric temperatures CO2 increase this order. temperature−pressure projection indicated structural transition...

Phase equilibria (pressure−temperature relations) of the H2 + tetrahydrofuran mixed gas hydrate system have been measured for various concentrations aqueous solutions. The three-phase equilibrium lines obtained in present study are shifted to low-temperature or high-pressure side from that stoichiometric THF solution. Each line converges at pure hydrate. At cross point on lines, concentration mother solution agrees with each other. Raman spectra and do not change variation mole fraction 0.010 0.130

Isothermal phase equilibria (pressure−composition in the gas phase) for quaternary system of H2 + CO2 tetrahydrofuran water have been measured presence hydrate phase. The lowest three-phase equilibrium pressure is obtained under condition that mole fraction 0.056. Raman spectroscopy results show and molecules competitively occupy S-cage structure-II (i.e., molecule enclathrated cages with a small amount at considerably low pressure).

The authors reviewed the correlations of power consumption in unbaffled and baffled agitated vessels with several kinds impellers, which were developed a wide range Reynolds numbers from laminar to turbulent flow regions. based on Kamei Hiraoka's expressions for paddle pitched impellers. calculated correlation values agreed well experimental ones, will be other types

Understandings of structure-based properties porous materials, such as gas storage and separation performance, are important. Here, the crystal structures canonical structure II (sII) clathrate hydrates encapsulating cyclic molecules (tetrahydrofuran, cyclopentane, furan, tetrahydropyran) studied. To understand effect guest on host water framework, we performed powder X-ray diffraction measurements where hydrate distribution within 51264 cages were obtained by direct-space technique followed...

The three-phase equilibrium (pressure−temperature) relations were measured for the hydrofluorocarbon (HFC) (1,1,1,2-tetrafluoroethane (-134a), pentafluoroethane (-125), or 1,1,1-trifluoroethane (-143a)) + water binary systems containing gas hydrate. measurements performed in pressure range up to 10.0 MPa and temperature of (273.15 295.15) K. invariant quadruple points (gaseous HFC, liquid aqueous, hydrate phases) located at 283.19 K 0.416 (HFC-134a), 283.95 0.930 (HFC-125), 283.33 0.838...

The three-phase equilibrium (pressure−temperature) relation of the difluoromethane + water binary system containing gas hydrates was measured in pressure range from (0.20 to about 11.0) MPa and temperature (275.15 300.15) K. On basis each curve, quadruple point which consists gaseous liquid difluoromethane, water, hydrate determined as 1.45 293.16 situ Raman spectroscopy under (gas, hydrate) conditions showed that crystal structure structure-I, where both small large cages were occupied by...

撹拌槽内の流れは，非定常の3次元流であるだけでなく空間的にも非対称であるため，その構造は極めて複雑である．そのため，撹拌槽内の流体混合機構についてはいまだ不明な点が多い．2次元の層流カオス混合系では，安定多様体と不安定多様体が流体混合機構を理解する際の重要な概念となり，それらが混合機構を支配する不変構造あるいは混合パターン形成の鋳型となっている．しかし，撹拌槽内の3次元流体混合場においても同様の役割を果たす不変構造が存在するか否かについてはいまだ不明である．本研究では，不安定多様体と同様の特性を有する流脈に着目して，2枚パドル翼をもつ撹拌槽内における層流流体混合機構の解析を行った．翼先端から伸びる流脈が混合パターン形成と密接な関係があることを実験およびモデル解析より明らかにするとともに，層流場における撹拌槽内の大域的な流体混合が，側壁近傍における流脈線の強い引き伸ばしと折り畳み機構から生み出されることを示した．

We have already reported the cage unoccupancy of hydrogen in CO 2 hydrate from Raman spectroscopic analysis and thermodynamic using Soave -Redlich -Kwong equation state.On other hand, at low temperatures, Kim Lee (Journal American Chemical Society, vol.127, pp.9996-9997, Jul.2005) claimed that is enclathrated hydrate.In present study, was reconfirmed clearly by situ spectroscopy for single crystal gas hydrates.Isothermal phase equilibria (pressure -composition) spectra three ternary systems...

Thermodynamic stability and hydrogen occupancy on the + tetra-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>n</mml:mi></mml:math>-butyl ammonium bromide semi-clathrate hydrate were investigated by means of Raman spectroscopic phase equilibrium measurements under three-phase condition. The structure mixed gas hydrates changes from tetragonal to another around 95 MPa 292 K depending surrounding fugacity. occupied amount in increases significantly associated with structural...

撹拌槽内の流れは撹拌翼や邪魔板によって複雑化されるため，流体混合機構の解析は容易ではない．撹拌槽内を動く流体粒子軌跡の複雑さの特徴は，非定常性と3次元性と非対称性にあるが，このような運動を引き起こす流れ場も同様の複雑さを備えている必要はない．本論文では，撹拌槽内における流体粒子軌跡の複雑な動きを再現できる簡易流動モデルを提示する．流動モデルはいくつかの要素的流れの線形和として構成され，各要素流れを表す式中に含まれるパラメータの選び方により，羽根形状・羽根枚数・羽根設置高さなどが異なる撹拌翼や，邪魔板を挿入した撹拌槽内流れにも対応できる．要素流れの組み合わせ方や強度を変えることにより，多様な撹拌槽内流れを再現できる．撹拌槽内の流体混合に直接関与する流れを特定し，その要素流れによる混合のメカニズムを解明するのに，本簡易流動モデルは有力な道具となり得る．

A varifocal concave–convex lens using ultrasound and transparent viscoelastic gel is reported. The configuration of the simple thin, consisting four pieces a piezoelectric transducer, glass disk, silicone film. It uses combination resonant flexural standing- traveling-wave modes excited by in-phase four-phase drives so that can change its shape to both concave convex switching resonance mode with same structure. acoustic radiation force (ARF) originated from vibration changed surface profile...