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Volume 20 (1993)
- Issue 4 Pages 175-
- Issue 3 Pages 111-
- Issue 2 Pages 61-
- Issue 1 Pages 2-
Volume 20, Issue 3
Displaying 1-8 of 8 articles from this issue
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Takahiro Miyata, Michiko Kodama1993 Volume 20 Issue 3 Pages 111-117
Published: July 30, 1993
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSOn annealing at 5°C of a gel phase temperature, multilamellar vesicles of dimyristoylphosphatidylglycerol (DMPG) prepared in the presence of 1M NaCl at pH 7.0 converted to well-developed crystalline cylindrical structures similar to those formed by Ca2+-bound DMPG. The new crystalline phase transformed into the liquid crystal phase at 44.2°C. The transition enthalpy (∼19kcal/mol) is about 2.5 times larger than that of the MLV gel to liquid crystal phases, suggesting a large contribution of pseudo lattice enthalpy to the chain-melting transition of Na+-bound DMPG in the present system. The conversion process of the MLV gel to cylindrical crystalline phases with an increase in annealing time was investigated by electron microscopy and it was found that a set of membranes (8-9 lamellae) separated from the MLV surface grows into helical superstructures and, subsequently, into the final cylindrical structures.View full abstractDownload PDF (1471K) -
Satoshi Morimoto1993 Volume 20 Issue 3 Pages 118-131
Published: July 30, 1993
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSA highly sensitive liquid flow reaction-solution microcalorimetry system based on the heat conduction principle with multi-thermomodules, applicable to suspended solutions was developed. This calorimetry system was well suited for measurements on the biochemical and solution chemical studies. Two concrete examples; binding and reaction studies in Na+, K+-ATPase- ATP system by using suspended Jørgensen's sample, and studies on the interactions of the oxyethylene moiety of poly (oxyethylene) glycole alkylether with benzene, by means of this microcalorimetry were introduced and explained.View full abstractDownload PDF (2012K) -
On Temperature Measurement and Control of ThermobalanceAkikazu Maesono, Toshiyuki Masuda1993 Volume 20 Issue 3 Pages 132-138
Published: July 30, 1993
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSSeveral factors in temperature measurement (T.M.) and temperature control (T.C.) that can affect the precision of thermogravimetry will be discussed. The type of current thermobalance can be classified into three types by the location of the T.M. and T.C. sensors on thermobalance, as shown in Fig. 1. Using the thermobalance which its T.C. sensor is located near furnace, the heating rate is slowed down and then the biginning and finishing temperatures of the decomposition are shifted towards higher temperature side during endothermic thermal decomposition process in isochronal thermogravimetry. Advantages can be obtained in using the thermobalance, dcsigned by authors, which has only one temperature sensor for both of T.M. and T.C. and uses a radiant image furnace with infrared lamps of low heat capacity for the purpose of precise thermogravimetry in both the constant heating rate and isothermal stepwise heating/cooling modes.
The location of T.M. and T.C. sensors in thermobalance used should be expressed with the other measuring canditions, such as heating rate, in the report of thermogravimetry.View full abstractDownload PDF (904K) -
Differential Scanning Calorimetric StudiesShinichi Kitamura1993 Volume 20 Issue 3 Pages 139-145
Published: July 30, 1993
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThis review describes the application of high sensitivity DSC to the study of the conformational transitions of polysaccharides in solution. Multi-stranded structures, which have been found for certain polysaccharides, are stabilized by cooperation of numerous non-bonded interactions between sugar molecules often involving solvent molecules. Since these cooperative structures undergo conformational transitions with changing temperature, information concerning these structures can be obtained by DSC. One of major advantages of the calorimetric method as compared with optical methods is that it gives values both for the apparent, or van't Hoff, enthalpy, the quantity derived from optical experiments, and for calorimetric enthalpy. The ratio of van't Hoff enthalpy to calorimetric enthalpy can be employed to obtain an estimate of size of the cooperative unit for the process under study. As current examples of the application, studies of the conformational transitions of triple helical polysaccharide schizophyllan and of double helical polysaccharide xanthan are presented.View full abstractDownload PDF (2155K) -
Kenji Ema1993 Volume 20 Issue 3 Pages 146-153
Published: July 30, 1993
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSSome aspects in the recent development in ac calorimetric techniques have been reviewed. The topics included are as follows. Heat capacity spectroscopy as an effective tool for the study of dynamic process in a sample through entropy response. A microcalorimeter for a small quantity of liquid sample with a high accuracy. Thermal diffusivity measurement of thin films and fine wires. Heat capacity measurement of extremely thin free-standing liquid-crystal films. A complex calorimeter with ac- and relaxation-mode operation using the same sample cell and the same apparatus settings.View full abstractDownload PDF (1157K) -
A Measure of the StateMasaichi Yamamura, Yoshimi Ishihara, Tomoichi Ohkubo, Ikuko Ohtani, No ...1993 Volume 20 Issue 3 Pages 154-161
Published: July 30, 1993
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSWhole body calorimetry was used to measure the heat dissipated by a mouse and hence determine its state. The measurement was continuously done for 32 hours from 10:00 till 18:00 of the following day. It was found that a clear rhythm could be seen, when a mouse was healthy, i. e. circadian rhythm. Each individual mouse displayed a surprisingly similar pattern, when repeated measurements were made at various time intervals. Although the addition of a plant extract to drinking water caused weight loss, probably due to bitterness of the drinking water and a cousequent reduction in food intake, the circadian rhythm was not disturbed. The rhythm was completely disrupted, when pain was induced by injecting 0.1M acetic acid intraperitoneally, this was partially normalised when 100mg/Kg Aspirin was given. However it was surprising that injection of Aspirin into a normal mouse caused a disturbance in rhythm. Interestingly no heat was dissipated when mice were under anaesthesia.
The result clearly indicate that whole body calorimetry is a useful tool to determine the state of a mouse as well as individuality.View full abstractDownload PDF (1204K) -
Akira Nagashima1993 Volume 20 Issue 3 Pages 162-168
Published: July 30, 1993
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSExamples of engineering interest in the crossover expressions for critical enhancement of thermophysical properties are explained. Designing and controlling a power plant, a chemical plant or various energy conversion machineries require very precise formulations, charts or computer softwares over a wide range of temperature and pressure including the critical region. Development of crossover expressions is needed for working fluids and fluids for energy conversion.
In the case of thermodynamic properties, approaches based on the combined equations of state using a so-called switching function often encounter serious troubles when derived functions are to be calculated. Other approaches include extention of an asymptotic scaling equation, extention of far-field analytic equation into the critical region and so on. Development of an universal theoretical expression of crossover is needed not only for scientific calculations but also for engineering applications.View full abstractDownload PDF (985K) -
T. Hatakeyama, S. Nakamura1993 Volume 20 Issue 3 Pages 169-171
Published: July 30, 1993
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSDownload PDF (452K)
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