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Volume 31 (2004)
- Issue 5 Pages 227-
- Issue 4 Pages 164-
- Issue 3 Pages 100-
- Issue 2 Pages 62-
- Issue 1 Pages 2-
Volume 31, Issue 4
Displaying 1-6 of 6 articles from this issue
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Thermodynamics in strongly correlated electronsIchiro Terasaki2004 Volume 31 Issue 4 Pages 164-171
Published: September 17, 2004
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSA strongly correlated electron system is a system that the Coulomb repulsion between electrons is too strong to hold the one-electron picture in solids. As a result, it can exhibit superior functions to conventional solids in which one-electron picture (band picture) is valid. Recently, thermoelectricity due to strong correlation has attracted a keen interest, and some transition-metal oxides, which are typical examples of strongly correlated electron system, can be a good thermoelectric material. In this article we will review the thermoelectric and thermodynamic properties of the transition-metal oxides through thermopower measurement.View full abstractDownload PDF (1752K) -
Takuya Hashimoto2004 Volume 31 Issue 4 Pages 172-178
Published: September 17, 2004
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSNew phases have been discovered in high functional perovskite-type oxides with various thermal analyses and X-ray diffraction under specific conditions such as high temperatures and high pressures. The second order phase transition was observed in Ba2In2O5 at 1070°C by dilatometry and quantitative DTA. It was revealed that distortion from the ideal cubic perovskite structure is the smallest in the phase found at higher temperatures than 1070°C and that this phase has the highest potential as an oxide-ion conductor among three phases in Ba2In2O5. In addition to the three phases in BaBiO3 already discovered by neutron diffraction measurement so far, another phase has been observed by dilatometry and quantitative DTA in temperature range 520∼620°C. The X-ray diffraction peaks indicating existence of superstructure was observed in diffraction pattern of BaBiO3 at 600°C. Variations of enthalpy, ΔH, and volume, ΔV, were estimated by DSC and high-temperature X-ray diffraction, respectively. Combining Clapeyron formula, positive ΔH and negative ΔV, phase transition under high pressure at room temperature was deduced and confirmed by X-ray diffraction at high pressures.View full abstractDownload PDF (1530K) -
Youichi Ueda, Masahiko Okamoto, Yasutaka Ohgami, Kiyoshi Nakai2004 Volume 31 Issue 4 Pages 179-185
Published: September 17, 2004
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSA stability test is one of the tests which are required the longest time in a development of a drug. For quick release of new drugs to the market, it is indispensable to estimate stability speedily from exact information in preliminary stability tests, and to minimize idle time at an early developmental stage. However, it is technically difficult to predict exactly in a short time before a stability test, what decomposition will occur.
We developed a new stability prediction method using thermal analysis to solve the problem. This method is very speedy; it only takes two weeks to predict stability of a drug substance in detail. The operations are simple; mainly thermal analysis and liquid chromatography. The method is performed by minimum 1mg per measurement. And total amount of sample being necessary to predict stability is approximately 20mg. The sample quantity is so little that the method can be used even at an early developmental stage when production scale is small. Furthermore, the accuracy and the precision of prediction using the method are equivalent to or better than those of 6-month preliminary stability tests. This method is very widely applicable to chemical materials including pharmaceutical raw materials, pharmaceutical intermediates, agricultural chemicals, and pesticides.View full abstractDownload PDF (1421K) -
Kunihiko Gekko2004 Volume 31 Issue 4 Pages 186-193
Published: September 17, 2004
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThis review is devoted to illustrate how the hydration of proteins is related to their volume and compressibility. Partial volume and partial compressibility are thermodynamic (macroscopic) quantities but they are uniquely sensitive to the structures of proteins because the hydration and the atomic packing (cavity) have counteractive effects on these parameters. Compressibility data give important information on the flexibility of the native structure and the conformation of denatured states. Viewing a protein from both the temperature and pressure axes should lead to a new paradigm in protein science.View full abstractDownload PDF (1344K) -
Takeo Ozawa2004 Volume 31 Issue 4 Pages 194-199
Published: September 17, 2004
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThe theme dealt with in this article is non-isothermal kinetics of various processes in which multiple elementary processes are involved. Firstly fundamental equation of non-isothermal nucleation and growth process is derived and it is compared with isothermal fundamental equation. From the fundamental equation, method of kinetic analysis of data by constant rate heating or cooling is derived. Theoretical considerations are also made for parallel competitive reactions and consecutive reactions. For the former some simple relations useful to elucidate the process can be derived, but for the latter such a simple useful relation cannot be found, but a fundamental equation is derived for specific cases. Finally usefulness of temperature oscillation for analyzing reversible processes is discussed together with its application to a reaction of a single elementary process.View full abstractDownload PDF (1642K) -
2004 Volume 31 Issue 4 Pages 200
Published: September 17, 2004
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSDownload PDF (166K)
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