• Journal of the Korean Chemical Society
• /
• v.31 no.5
• /
• pp.395-399
• /
• 1987

The two dissociation constants of leucine were measured in the temperature range from 15 to 40$^{\circ}$C and pressure up to 2,500 bar by conductometric method. Both constants were increased as the temperature increased but pressure effect was not same as temperature effect. The first constants were increased as pressure increase but the second constants were decreased as pressure increase in the law temperature range but increased in some higher temperature range. These phenomena were discussed from the thermodynamic properties of the dissociation reactions.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.21 no.2
• /
• pp.69-80
• /
• 2010

This study analyzed the Harris's philosophical ideas, American library classification in the Harris's era, and relationship to Bacon, Hegel, DDC based on the Harris's classification system. As is generally known so far, Harris himself described to have derived his classification from inverted Baconian arrangement. It is nowhere to be found that Harris reflected on Hegel's philosophical ideas in his scheme. But on this study, Harris was a Hegelian and a leading American exponent of ideas of Hegel at that time. So we can analogize being reflected on Hegelian philosophy in the Harris's scheme and actually the Hegelian basis can be founded for much of Harris's scheme. Also we can find that Harris's scheme springs directly from Bacon and indirectly Johnston's scheme.

• Journal of the Korean Chemical Society
• /
• v.30 no.2
• /
• pp.159-165
• /
• 1986

The effects of substituents, pressure and temperature on the dissociation constants of alkylpyrines(2, 3 and 4-methyl and ethyl) were studied by measuring the dissociation constants of pyridines by conductance method at various temperatures and pressures in aqueous solution. The constants were increased as the temperature increase but decreased as pressure increase. From the constants various thermodynamic properties were calculated and discussed the dissociation reactions. It was estimated that alkylpyridines have exceptional dissociation reactions.

• Journal of the Korean Chemical Society
• /
• v.27 no.5
• /
• pp.311-319
• /
• 1983

The dissociation constants of anilinium ion, o-toluidinium ion, phenol and o-chlorophenol were measured spectroscopically in aqueous solution over the temperature range of 10∼40$^{\circ}C$ and at the pressures up to 2,000 bars. The effects of temperature and pressure on the dissociation of the phenols are the same as those of the ordinary weak acids. Meanwhile the dissociation constants of anilinium ions are increased with temperature raising and decreased with pressure elevation. The effects of pressure on the constants can be explained by taking account of change of charge during dissociation reaction; there are increase in charge in the dissociation of phenols but anilinium ions are not. Several thermodynamic properties, ${\Delta}H^{circ}$,${\Delta}G^{circ}$, ${\Delta}S^{circ}$,${\Delta}V^{circ}$ and ${\beta}$ are calculated from those constants, and the dissociation reactions are discussed by them.

• Journal of Chest Surgery
• /
• v.35 no.8
• /
• pp.599-604
• /
• 2002

Acute or chronic aortic dissection may lead to the rupture, which is the major cause of death. A dissecting aneurysm of ascending aorta(Stanford type A dissection) can rupture into the superior vena cava producing a aortocaval fistula, which is rare, but has been reported mostly in the cases of abdominal aortic aneurysm. We report a case of 67-year-old man with type A chronic dissection and aortocaval fistula, presenting symptoms of superior vena syndrome. The preoperative diagnosis was composed of radiologic examinations, including computed tomography, magnetic resonance imaging angiography and aortography. The dissecting aneurysm was resected and replaced, and the aortocaval fistula was repaired under deep hypothermic circulatory arrest. The details are described here.

• Journal of the Korean Chemical Society
• /
• v.33 no.4
• /
• pp.343-349
• /
• 1989

The dissociation constants of ${\beta}$-alanine and ${\gamma}$-aminobutyric acid were measured in the temperature range from 20 to $40^{\circ}C$ and pressure up to 2,500 bar by conductometric method. The both dissociation constants of respective amino acid increase with temperature increase but pressure effect is not same as the temperature. The $K_1$ increases as pressure increases but $K_2$ decreases. The properties of these amino acids were discussed in terms of the thermodynamic properties of the dissociation reaction. A relationship between the dissociation constants and the distance between substituted groups of amino acid was discussed. The substituted effects of the reaction were deduced from Hammett reaction and substituted constants which were calculated from the measured dissociation constants.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.11
• /
• pp.1177-1184
• /
• 2011

Gas-to-Solid (GTS) technology is composed of three stages: hydrate production, transportation, and regasification. For efficient operation of regasification plants, it is crucial to predict the temperature and flow rate of hot water necessary to dissociate the hydrate pellets. Dissociated gas escaping from the pellet surface, when in contact with hot water, will alter the flow field and consequently alter the heat transfer rate. Methane hydrate pellet dissociation characteristics in low- to moderatetemperature water were investigated by taking images of the changes in the hydrate pellets' shapes in a pressurized reactor and measuring the total time required for complete melting of the pellets. The effects of water temperature, hydrate conversion rate, and flow speed on the dissociation completion time were also investigated. Bubbling gas released from the pellet surface induced a secondary flow that enhanced the heat transfer rate and thus decreased the dissociation time. It was also found that a considerable flow rate was needed to significantly decrease the dissociation time.

• Journal of the Korean Chemical Society
• /
• v.35 no.2
• /
• pp.105-110
• /
• 1991

The dissociation constants of valine and norvaline in aqueous solution were measured by conductometric method in various temperatures and pressures. The properties of the dissociation reaction were discussed in term of the thermodynamic properties of reaction. These substituted effects on the dissociation reaction were discussed on the points of Hammett relation and net charge of the O and N-atom calculated from CNDO/2 method respectively.

• Korean Journal of Psychosomatic Medicine
• /
• v.24 no.1
• /
• pp.109-116
• /
• 2016

Objectives : This study aimed to investigate the effects of resilience on posttraumatic stress symptoms and dissociation and whether depression mediates the relationships between resilience and posttraumatic stress symptoms and dissociation. Methods : A total of 115 firefighters participated in the study. Data were collected via the Life Events Checklist, Impact of Event Scale-Revised, Dissociative Experience Scale, Beck Depression Inventory, and Connor-Davidson Resilience Scale. Structural equation modeling and path analysis were applied to estimate the relationships between resilience, depression, posttraumatic stress symptoms, and dissociation. Results : Greater resilience was associated with lower posttraumatic stress symptoms and dissociation, and the relationship between them was fully mediated by depression. Conclusions : Specific aspects of depression may help explain the relationships between resilience and posttraumatic stress symptoms and dissociation. Tailored prevention programs and treatments based on resilience and depression may prevent posttraumatic stress symptoms and dissociation in firefighters and improve treatments outcomes among firefighters with posttraumatic stress symptoms and/or dissociation.

• Journal of the Korean Chemical Society
• /
• v.30 no.2
• /
• pp.145-151
• /
• 1986

Using a new conductometric method, dissociation constants of 3-cyano, 4-cyano, 3-amino and 4-aminopyridine were measured in the temperature range 15 ∼ 40${\circ}C$ and pressure up to 2500bar in aqueous media. This method is convenient to apply to the low dissociative acid and base but have to do tedious extrapolating procedure for the ionic conductance in elaborated temperatures and pressures and have to know any reference dissociation constant. The measured dissociation constants were increased as the temperature increase but decreased as the pressure increase. From the constants, various thermodynamic properties were evaluated and discussed for the dissociation reactions.