特集-超臨界水の科学と技術- Rev. High Pressure Sci. Technol. 6-1,16-23(1997) |
高温高圧下の水の構造 Structure of Water at High Temperatures and Pressures |
松林 伸幸 中原 勝 Nobuyuki MATUBAYASI Masaru NAKAHARA |
Recent progress in the structural studies
of water in the super- and subcritical conditions
is reviewed with an emphasis on the hydrogen
bonding. The structural characteristics of
water at high temperatures and pressures
predicted from computer simulations are briefly
presented and compared to the results from
neutron scattering experiments. The NMR experiments
on water in extreme conditions are then described
in detail, and the strength of the hydrogen
bonding in supercritical water is discussed
in terms of the chemical shift. The NMR chemical
shift experiments and the computer simulations
support the persistence of the hydrogen bonding
in supercritical water. [supercritical water, structure, hydrogen bonding, Proton chemical shift, computer simulations, neutron scattering, X-ray diffractometry] |
〒611-0011 京都府宇治市五ヶ庄 京都大学化学研究所 Institute for Chemical Research, Kyoto University, Uji-city, Kyoto 611-0011 |
特集-超臨界水の科学と技術- Rev. High Pressure Sci. Technol. 6-1,24-29(1997) |
ラマン分光法による超臨界水の水素結合構造の検討 An In Situ Laser Raman Spectroscopy Study on the Structure of Supercritical Water |
生島 豊 Yutaka IKUSHIMA |
The structure of high-pressure and supercritical
water has been examined up to 510 ℃ and
40 MPa with in situ laser Raman spectroscopy. At 24 MPa or below,
the hydrogen bonding in the tetrahedral configuration
becomes weaker and this structure breaks
with increasing temperature, especially near
the critical temperature, above which small
clusters like dimers are dominant species.
At higher pressures, a similar but slight
structural change occurs; however, the tetrahedral
configuration is predominant above the critical
temperature. Near the critical point, short-lived
tetrahedral configurations are significantly
increased and coexist with dimer and monomer
structures at equilibrium. [ Supercritical water, laser Raman spectroscopy, structure, hydrogen bonds ] |
〒983-8551 仙台市宮城野区苦竹 4-2-1 東北工業技術研究所機能化学部反応化学研究室 National Industrial Research Institute of Tohoku, 4-2-1 Nigatake, Miyagino-ku, Sendai 983-8551 |
特集-超臨界水の科学と技術- Rev. High Pressure Sci. Technol. 6-1,30-35(1997) |
地球惑星内部における水の役割 Role of water in the Earth and Planets |
大谷 栄治 Eiji OHTANI |
Role of water in the Earth and planets is
discussed. Water is one of the most important
species controlling the dynamics and evolution
of the Earth and planets. Water decreases
the melting temperature of the mantle materials,
and promotes the magmatism of the Earth.
Water has a large effect on the rheology
of the crust and mantle minerals such as
quartz and olivine, as is called hydrolytic
weakening (water weakening). Small amount
of water strongly enhances flow and deformation
in the crust and mantle. Water is trapped
as various hydrous minerals in the deep mantle
especially under the low temperature conditions
such as in the descending slabs. Water together
with other volatile species such as H2, He and CH4 , and NH3 is an important constituent in the Jovian
planets and satellites. Water bearing supercritical
fluid plays very important roles in the deep
atmosphere of the Jovian planets. [water, Earth, hydrolytic weakening, hydrous minerals, Jovian planets, supercritical fluid] |
〒980-8578 仙台市青葉区荒巻字青葉 東北大学理学部地球物質科学科 Institute of Mineralogy, Petrology, and Economic Geology, Tohoku University, Aoba-ku, Sendai 980-8578 |
特集-超臨界水の科学と技術- Rev. High Pressure Sci. Technol. 6-1,36-45(1997) |
高温岩体およびマグマの掘削へのウォ−タ−ジェット技術の応用 Application of Water Jet Technology to Drilling Hot Dry Rock and Magma |
幾世橋 広 Hiroshi KIYOHASHI |
Recent progress in conventional geothermal
drilling technology was briefly reviewed.
Then a series of fundamental experiments
on water jet drilling a hole in hot
dry rocks(HDR)
and magma performed by the author was
summarized.
In the experiments, artificial rocks
made
of refractory materials and some kinds
of
rocks at elevated temperatures up to
1100
℃ were used and flow pressure of the
water
jet of room temperature at nozzle exit
was
changed from 2.45 to 194 MPa. It was
discussed
how the temperature and physical properties
of the target materials, standoff distance,
pressure of the water jet, nozzle diameter,
and so on influence the jet penetration
patterns,
depth and volume in the materials.
[artificial rock, rock, elevated temperature, hot dry rock, magma, water jet, high pressure, jet penetration] |
〒980-77 仙台市青葉区荒巻字青葉 東北大学大学院工学研究科地球工学専攻 Department of Geoscience and Technology, Graduate School of Engineering, Tohoku University,Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-77 |
解説 Rev. High Pressure Sci. Technol. 6-1,46-51(1997) |
IAPWSより公表された軽水および重水の表面張力の新リリースについて New IAPWS Releases on Surface Tensions of Ordinary Water and Heavy Water Substances |
高石 吉登 Yoshinori TAKAISHI |
In March of 1996 International Association
for the Properties of Water and Steam (IAPWS)
issued two newly revised releases on surface
tensions of ordinary water substance and
heavy water substance. This revision includes
changes of the recommended values based on
the International Temperature Scale 1990
(ITS-90) and new correlation equations giving
the surface tension as a function of temperature.
This article reports the contents of the
new releases. [surface tension, ordinary water, heavy water, ITS-90, IAPWS] |
〒243-0292 厚木市下荻野1030 神奈川工科大学工学部機械工学科 Kanagawa Institute of Technology, 1030 Shimo-Ogino, Atsugi 243-0292 |
解説 Rev. High Pressure Sci. Technol. 6-1,52-57(1997) |
高分子ゲルの体積相転移 Volume Phase Transition of Polymeric Gel |
石田尾 徹 大谷 信之 荒井 康彦 Toru ISHIDAO Nobuyuki OHTANI Yasuhiko ARAI |
It has been shown that some polymeric gels
undergo continuous or discontinuous volume
changes depending on external conditions
(e.g., temperature, pH and solvent concentration).
Therefore, the gels are expected to be applied
as a size-selective extraction solvent and
other functional materials. To apply the
gel as an extractor or other functional materials,
we should study volume changes of the gel
in solvent mixtures and concentrations inside
and outside the gel. Furthermore, fundamental
knowledge of mesh sizes of gel network and
interactions between network and solvents
have become very important. Therefore, fundamental
studies and applications of polymeric gel
are reviewed: Thermodynamic models for polymeric
gels are reviewed. Finally, pressure-dependent
phase transitions in polymeric gels are briefly
reviewed and discussed. [polymeric gel, volume phase transition , aqueous solution , solvent concentration, pressure-dependence ] |
〒812-8581 福岡市東区箱崎 6-10-1 九州大学大学院工学研究院化学工学部門 Department of Chemical Engineering , Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 |
解説 Rev. High Pressure Sci. Technol. 6-1,58-65(1997) |
気液界面における蒸発凝縮の分子機構とその周辺 Molecular Mechanism of Evaporation-Condensation on Vapor-Liquid Interface |
松本 充弘 Mitsuhiro MATSUMOTO |
Molecular dynamics computer simulation technique
has been applied to investigate fluid phase
change mechanisms near vapor-liquid interfaces.
The simulation enables us to estimate the
most relevant parameter, condensation coefficient
αc, which is the ratio of condensation flux
to vapor collision flux. We found: (i)αc is less than unity even for simple fluids,
and αc of associating fluids is much less than
that. (ii) There is a strong temperature
dependence of αc. (iii) Under the nonequilibrium condition,
αc depends also on the density (or pressure)
and the temperature of the vapor. A simple
evaporation model based on a transition state
theory can explain this behavior to some
extent. As related topics, molecular dynamic
of nucleation processes is also described. [vapor-liquid interface, evaporation, condensation, fluid phase change, molecular dynamics, computer simulation ] |
〒464-01 名古屋市千種区不老町 名古屋大学工学部応用物理学科 Department of Applied Physics School of Engineering , Nagoya University, Nagoya 464-01 |
〒606-0805
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