• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2001년도 추계학술대회 및 정기총회
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• pp.88-88
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• 2001

The effects of pH and temperature on the degradation of prokidn in various buffered aqueous solutions(pH 1.32~9.66) and temperatures (35, 45 and 6$0^{\circ}C$ were investigated. The effect of ionic strength on the degradation of prokidin was also measured by varying ionic strength (0.0466~1.5) at pH 1.35 and 45$^{\circ}C$ The effect of metal ions on the degradation of prokidin at pH 7.35 and 3.98 was observed. The degradation of prokidin followed the pseudo- first- order kinetics. The degradation rate of prokidin showed pH-dependent and temperature-dependent patterns. Prokidin was very stable at the pH below 3.95, where half-lives at 35, 45 and 6$0^{\circ}C$were 294, 206 and 107 day, respectively. However, it degraded very rapidly at pH above 6.49; the half-lives at 35, 45 and 6$0^{\circ}C$were 60, 25 and 13 day, respectively. As ionic strength increased, the degradation rate of prokidin increased. Some metal ions increased the degradation rate in the rank order of Mn > Fe > Cu >Fe On the other hand. other metal ions such as Bi, Ba. Zn, Ni, Co did not show unfavorable effect.

• 한국의류학회지
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• 제22권8호
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• pp.1032-1042
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• 1998

The purpose of this study is to measure, compare, and investigate the physical properties of rayon/cotton blend fabrics treated with cellulase and cellulase & specific degeneration silicon and to present basic data which is in development a value-added fabric. The results are as follows. The condition for the treatment of cellulase was at 55$^{\circ}C$, pH 4 and the weight loss increased as the concentration of cellulase and the treated time increased. On treatment with cellulase, the crossectional view & longitudinal view of fiber noticed remarkable crack as weight loss increased and tensile strength and elongation decreased, and pilling was enhanced remarkably. KOSHI was increased, NUMERI and FUKURAMI were decreased as weight loss increased. In the basic characteristic value of clothing wearning, shape stability and drapability were decreased, but air content was improved. On treatment with cellulase & silicon, the degree of damage in the crossectional view & longitudinal view of the fiber reduced. Tensile strength, elongation, moisture regain improved. KOSHI and FUKURAMI were reduced, NUMERI was improved rather than when it was treated with cellulase. Therefore handle was improved. In the basic characteristic value of the clothing wearing, shape stability, air content, drapability were improved.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
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• pp.356-365
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• 1999

The present study is aimed at developing the TRIP(transformation induced plasticity) aided high strength low carbon steel using reversion process. An excellent combination of elongation over 40% and tensile strength abut 100kgf/$\textrm{mm}^2$ achieved in processing of 0.15C-0.5 Si-6Mn steel by slow heating to intercritial temperature region and accelerated cooling into room temperature. This good combination is caused by TRIP phenomena of retained austenite in steels during deformation. The stability of retained austenite is very important for the good ductility and it depends on the diffusion of carbon and manganeses during heat treatment. The accelerated cooling after holding at annealing temperature retards the formation of pearlite and provides the carbon enrichment in retained austenite in steel, resulting in the increase in elongation of the cold-rolled TRIP steel. On the other hand, heat treating the steel at 600$^{\circ}C$ for 5 hour before cold rolling increases elongation but reduces the amount of retained austenite after reversion processing. It is accounted that the heat treating is effective for the increase in the stability of retained austenite.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제1권2호
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• pp.69-80
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• 1997

Effects of light on leaf senescence of Phaseolus vulgaris were investigated by measuring the disassembly of chlorophyll-protein complexes in detached leaves which had been kept in the dark or under light. The loss of chlorophyll accompanied by degradation of chlorophyll-protein complexes. PSI (photosystem I) complex containing LHCI (light harvesting complex of PSI) apoproteins was rapidly decreased after the early stage of dark-induced senescence. RC(reaction center)-Core3 was slightly increased until 4 d and slowly decreased thereafter. As disassembly of LHCII trimer progressed after the late stage of senescence, there was a steady increase in the relative amount of SC(small complex)-2 containing LHCII monomer. On the other hand, white and red light adaptation caused the structural stability of chlorophyll-protein complexes during dark-induced senescence. Particularly, red light was more effective in the retardation of LHCII breakdown than white light, whereas white light was slightly effect in protecting the disassembly of PSI complex compared to red light. These results suggest, therefore, that light may be a regulatory factor for stability of chlorophyll-protein complexes in the senescent leaves.

• 한국주거학회논문집
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• 제4권1호
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• pp.47-55
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• 1993

The research was carried out by posing a questionnaire, making middle and high schoolstudents 549 in Taehu an object of this research, in order to grasp the residential outlook of juveniles.1. The first order of reason why they have resided in present their houses was by a school group and their parents' choice and work place and second order of reason was by their parents' choice, life convenience in present house add traffice convenience And there was littledifference in the first and second residential reasons according to sew.2. In compareson with past and present house type, past and present house type shewed same tendency and future wanted house type was separate house absolutely.3. Points to be considered in selectong future were in the order of facilities, traffice,, surrounding, educational, social and economical circumstances. There was little difference in almost items to be considered in choosing accordant to sew. But in case of schoolgirls, they consisered more items in selecting houses than in schoolboys.4. As a result of researching ideal house of juvenile, happy family was most Preferred and the desire to possess house was expressed strongly.5. The first value on house was health of family, the stability, the stabi]ity and the residential convenience. And schoolboys attacged more importance to the gealth of family, ghe stability and the education fer children than in case of school-girls but on the other hand school girls attached more importance to economical value house and happy and harmonious family.

• 한국직업건강간호학회지
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• 제26권1호
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• pp.55-64
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• 2017

Purpose: This study was performed for the effective management of nursing organization as surveyed choice motives and job satisfaction about nurses who changed to public hospitals. Methods: This study is a descriptive study. This study surveyed 214 nurses who changed jobs to public hospital in six Gyeonggi-do hospitals from October 23 to November 20, 2015. The collected data were analyzed for descriptive statistics, t-test, one-way ANOVA, sheffe test, multiple linear regression analysis using the SPSS/WIN 21.0 program. Results: Most of the nurses chose public hospitals due to benefits correspond to public officials. They had worked in general hospitals located on provinces and changed jobs due to a heavy workload and low benefits. Of the participants 84.1% were satisfied with changing jobs to public hospitals and the advantages of public hospitals of their choice were job stability and good employee benefits(guaranteed maternity and paternity leave, etc). On the other hand there were complaints about low salaries compared to the workload after changing jobs to public hospitals. Conclusion: Hospitals need to enhance job stability and provide nurses with good employee benefits to reduce turnover rate.

• 한국의류학회지
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• 제19권2호
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• pp.356-365
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• 1995

study was made to investigate the emulsification and rolling-up between liquid oily soils and surfactant and its effect on the detergency. Samples used were triolein as a triglyceride, oleic acid as a free fatty acid and sodium dodecyl sUJfate(SDS) as a surfactant. The results were as follows: 1. The spontaneous emulsification occurred in the system of oleic acid alone and mixture of triolein and oleic acid contacted with 0.5% SDS solution, but it did not occurred in a case of triolein alone. 2. The stability of emulsification increased with the increase of SDS concentration. And the stability of emulsification and (-) t value increased in the order of triolein < mixture of triolein and oleic and< oleic acid. 3. The rolling-up mechanism of model oily soils easily occurred in the order of triolein< mixture of triolein and oleic acid< oleic acid, and facilitated with the increase of SDS concentration. On the other hand, the complex formation was already observed in the system of oleic and 0.5% SDS solution. 4. As compared with the detergency of triolein, the detergency of oleic acid was very high. And the detergency of mixed soil was improved with increasing ratio of oleic acid in the mixture.

• Journal of Pharmaceutical Investigation
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• 제25권3호
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• pp.239-247
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• 1995

The physico-chemical stability of aucubin, a hepatoprotective iridoid glucoside, in buffered aqueous solutions was studied using a stability-indicating reversed-phase high performance liquid chromatography. The degradation of aucubin followed the pseudo-first-order kinetics. In strong acidic regions, aucubin was rapidly degraded by the specific acid catalysis, forming dark brown precipitates. From the rate-pH profiles, it was found that aucubin was most stable at the pH of about 10. From the temperature dependence of degradation, activation energies for aucubin at pH 2.1 and 4.9 were calculated to be 22.0 and 24.3 kcal/mole, respectively. The shelf-life $(t_{90%})$ for aucubin at pH 9.07 and $20^{\circ}C$ was predicted to be about 603 days. A higher ionic strength accelerated the degradation of aucubin at pH 4.01. The effect of metal ions on the degradation rate of aucubin at pH 7.16 was in the rank order of $Cu^{2+}\;>\;Fe^{3+}\;>\;Co^{2+}\;>\;Fe^{2+}\;>\;Mg^{2+}$. On the other hand, $Mn^{2+}\;and\;Ba^{2+}$ slowed the degradation rate.

• 한국식생활문화학회지
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• 제18권2호
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• pp.134-138
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• 2003

Quality stability of the herb pill coated with edible oils containing rosemary was investigated. Herb pills were made of herb powders such as Panax ginseng, Cinnamomum cassia, Lycium chinense, Zyzyphus jujuba and Zingiber officinale. Rapeseed oil and lubriol were used as edible coating oil. After herb pills coated with edible oils with or without rosemary were stored at $40^{\circ}C$ for 180 days, the microbial viable cell counts and peroxide values(POV) of the herb pill were investigated. After 180 day storage, POVs of herb pills with only rapeseed oil or lubriol were 0.51 and 0.49 meq/kg, respectively. However, when rosemary was added in herb pills the POVs were decreased to 0.30 and 0.39 meq/kg, respectively. The addition of rosemary to the rapeseed oil and lubriol tended to decrease the microbial viable cell counts of the herb pill. The microbial viable cell counts of rapeseed oil and lubriol were 940 and 820CFU/g, respectively after 180 days of storage. However, these levels were suppressed to 720 and 640CFU/g by the resemary addition. On the other hand, the ginseng saponin content of herb pills was not affected by the rosemary addition during storage.

• 한국유체기계학회 논문집
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• 제7권6호
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• pp.21-27
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• 2004

The floating ring seal has an advantage to find the optimum position by itself, which is used in the turbo pump of a liquid rocket. The main purpose of seals is to reduce the leakage. Especially, seals of the turbo pump for the liquid rocket engine are operated under the serious conditions such as high pressure above 10 MPa, very low temperature about $-180^{\circ}C$ and high rotating speed above 25,000 rpm. So, rotordynamic stability is very important for the system stability. In this paper, the leakage and dynamic characteristics of floating ring seals were investigated by a experimental and analytical method. The theoretical results of the leakage performance for the floating ring seal showed much higher than that of experimental results. On the other hand, the results of stiffness and damping characteristics showed similarity each other. As the shaft speed was increasing, the whirl frequency ratio was increased in the experimental results.