• KSBB Journal
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• 제17권4호
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• pp.396-402
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• 2002

바이오디젤(지방산 메틸 에스테르)은 생분해성, 무독성, 그리고 재생연료로서 지난 10여년간 많은 관심을 끌고 있다. 바이오디젤을 생산하기 위해 다양한 방법들이 개발되었는데, 그 중 알칼리 촉매를 이용한 에스테르화 반응이 짧은 시간동안 높은 수율을 얻을 수 있다. 따라서 본 연구에서는 알칼리 촉매하에 에스테르화 반응의 최적조건을 찾기 위하여 response surface method를 사용하였다. 결과적으로 바이오디젤 생산 공정에 영향을 주는 7개의 변수 중 반응온도, 반응시간, 그리고 교반속도가 중요했는데 이들의 최적 값은 각각 67$^{\circ}C$, 68분, 94 rpm이었다. 이와같은 최적인 조건하에서 실험한 결과 바이오디젤로의 전화율은 99.7%이었다.

• 대한간호학회지
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• 제30권1호
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• pp.98-109
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• 2000

The purpose of this study was to identify the effect on improvement of the Activity of Daily Living (ADL) and decrease the cognitive function and agitation behaviors by reminiscence with audio-visual stimulation for senile dementia. The quasi-experimental design was used in this study. Subjects were 26 with mild senile dementia who were cared for at a Day Care Center for Dementia in Seoul. The data were collected from March to July, 1999. Subjects were divided into three groups : Control Igroup with 10 subjects, reminiscence group(Control II group with 8 subjects), and reminiscence with audio-visual stimulation group(experimental group with 8 subjects). The Control I group got routine care as usual. Control II group participated in reminiscence sessions for one hour a day, five times a week , for a period of 4 weeks. The experimental group participated in reminiscence with audio-visual stimulation sessions for one hour a day, five times a week, for a period of 4 weeks. Instruments of this study were color photography with sound that was developed through an open questionnaire about events, objects, humans in action and animals that 100 Korean elderly over 60 would like to memorize. This was referred from the Sensory Stimuli Package by Namazi and Haynes(1994). The effects of treatment was evaluated through MMSE-K by Kwon & Park(1989). Also the Brief Cognitive Rating Scale(BCRS) by Reisberg et al(1983) for the cognitive function, through Agitation Inventory by Cohen- Mansfield and Colleague(1989) for behavioral response and through the Rapid Disability Rating Scale-2(RDRS-2) by Linn & Linn(1982) for the activity of daily living respectively. Data analysis was done using SPSS for $\chi$2- test, ANOVA, repeated measures ANOVA. The results were as follows : 1. Reminiscence with audio-visual stimulation did not improve cognitive function for senile dementia, but significantly improved verbal expression, the subscale of cognitive function. 2. Reminiscence with audio-visual stimulation reduced agitation behavior of experimental group significantly, but there was no significant difference between groups. 3. Reminiscence with audio-visual stimulation did not significantly effect the activity of daily living after treatment. In conclusion, it was shown that the reminiscence with audio-visual stimulation was an effective therapy to improve verbal expression and to reduce agitation behaviors of senile dementia. Further research with more indepth approach is needed, considering characteristic and level individualized for each senile dementia.

• 한국식품영양과학회지
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• 제1권1호
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• pp.51-62
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• 1972

In Korea, fermented fish has been playing an important role as a preserved and flavor rich food. It is said that the digestion of fish protein is due to both action of intrinsic (autolytic enzymes) and bacterial enzymes in fish. The mass production of fermented fish has been impeded since traditional method of fermentation requires a long duration for a complete digestion. A high concentration of salt and unsanitary condition are also considered disadvantages of the old method. To improve the quality of the product and to develop mechanized process of fermentation, fermentors which have such control device as temperature, pH and agitation control system have been urgently needed. In this study, a model design of a fermentor is studied. The calculation was based on the optimum conditions for enzymatic hydrolysis of fish protein which involve temperature, pH, viscosity and other factors.

• Food Science and Biotechnology
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• 제17권5호
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• pp.904-911
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• 2008

Covalent cross-links between a number of proteins and peptides explain why transglutaminase may be widely used by food processing industries. The objective of this work was optimization of the fermentation process to produce transglutaminase from a new microbial source, the Streptomyces sp. P20. The strategy adopted to modify the usual literature media was: (1) fractional factorial design (FFD) to elucidate the key medium ingredients, (2) central composite design (CCD) to optimise the concentration of the key components. Optimization of the medium resulted in not only an 86% increase in microbial transglutaminase activity as compared to the media cited in the literature, but also a reduction in the production cost. Optimal fermentation conditions - namely temperature and agitation rate - were also studied, using CCD methodology. Usual conditions of $30^{\circ}C$ and 100 rpm were within the optimal area. All other parameters for enzyme production were experimentally proven to be optimum fermentation conditions.

• 한국식품영양과학회지
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• 제38권1호
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• pp.116-120
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• 2009

포도즙의 알코올 발효 시 당 농도와 교반속도, 발효시간이 알코올함량과 총산도에 미치는 영향을 알아보기 위해 반응 표면분석을 이용하여 알코올발효 조건을 최적화하였다. 알코올함량은 10%, 총산도는 최소화되는 것을 목적으로 하여 알코올 발효조건을 최적화한 결과 $19.98^{\circ}Bx$로 농축한 국내산 Campbell early 포도즙에 효모를 접종시킨 후 교반속도 104.1 rpm으로 89.67시간 동안 발효시켰을 때 목적값에 가장 근접한 결과를 나타내었다. 알코올 발효 시 포도즙의 당도가 증가할수록 알코올함량과 총산도는 증가하는 경향을 나타내었고, 교반속도는 알코올함량과 총산도에 큰 영향을 주지 않는 것으로 나타났다. 또한 발효시간이 길어질수록 알코올 함량과 총산도가 증가하는 경향을 나타내었다.

• Nuclear Engineering and Technology
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• 제54권1호
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• pp.61-71
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• 2022

Pool boiling heat transfer is widely applied in nuclear engineering fields. The influence of heating surface orientation on the pool boiling heat transfer has received extensive attention. In this study, the heating surface with different roughness was adopted to conduct pool boiling experiments at different inclination angles. Based on the boiling curves and bubble images, the effects of inclination angle on the pool boiling heat transfer and critical heat flux were analyzed. When the inclination angle was bigger than 90°, the bubble size increased with the increase of inclination angle. Both the bubble departure frequency and critical heat flux decreased as the inclination angle increased. The existing theoretical models about pool boiling heat transfer and critical heat flux were compared. From the perspective of bubble agitation model and Hot/Dry spot model, the experimental phenomena could be explained reasonably. The enlargement of bubble not only could enhance the agitation of nearby liquid but also would cause the bubble to stay longer on the heating surface. Consequently, the effect of inclination angle on the pool boiling heat transfer was not conspicuous. With the increase of inclination angle, the rewetting of heating surface became much more difficult. It has negative effect on the critical heat flux. This work provides experimental data basis for heat transfer and CHF performance of pool boiling.

• Journal of Mechanical Science and Technology
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• 제19권10호
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• pp.1902-1909
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• 2005

A process for production of ethyl ester for use as biodiesel has been studied. The sodium hydroxide catalyzed transesterification of soybean oil with ethanol was carried out at different molar ratio of alcohol to oil, reaction temperature and catalyst amount for a constant agitation in two hours of reaction time. Central composite design and response surface methodology were used to determine optimum condition for producing biodiesel. It was found that ethanol to oil ratio and catalyst concentration have a positive influence on ester conversion as well as interaction effects between the three factors considered. An empirical model obtained was able to predict conversion as a function of ethanol to oil molar ratio, reaction temperature and catalyst concentration adequately. Optimum condition for soybean ethyl ester production was found to be moderate ethanol to oil ratio (10.5: 1), mild temperature range ($70^{\circ}C$) and high catalyst concentrations ($1.0\%$wt), with corresponding ester conversion of $93.0\%$.

• Journal of Microbiology and Biotechnology
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• 제22권7호
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• pp.923-929
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• 2012

Optimization of culture conditions for L-asparaginase production by submerged fermentation of Aspergillus terreus MTCC 1782 was studied using a 3-level central composite design of response surface methodology and artificial neural network linked genetic algorithm. The artificial neural network linked genetic algorithm was found to be more efficient than response surface methodology. The experimental $_L$-asparaginase activity of 43.29 IU/ml was obtained at the optimum culture conditions of temperature $35^{\circ}C$, initial pH 6.3, inoculum size 1% (v/v), agitation rate 140 rpm, and incubation time 58.5 h of the artificial neural network linked genetic algorithm, which was close to the predicted activity of 44.38 IU/ml. Characteristics of $_L$-asparaginase production by A. terreus MTCC 1782 were studied in a 3 L bench-scale bioreactor.

• 한국주거학회논문집
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• 제19권4호
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• pp.79-87
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• 2008

Snoezelen, multi-sensory stimulation, provides stimulation through the visual, aural, tactile, olfactory, gustatory and proprioceptive senses. Its aim is to be a relaxing, feeling of safety, novelty and stimulation with no expectations for performance. Agitated behavior of people with dementia causes significant problems and distress for cares. The objective of this research study was to test the effects of Snoezelen room on physical and verbal agitated behaviors of people with dementia. Four patients participated five sessions in Snoezelen room of 'F' dementia care facility in Sweden. Assessment instrument was basically used Cohen-Mansfield Agitation Inventory-Short Form to be rated by caregivers on a 5-point frequency scale. Pre-trial and post-trial assessments were carried out during $27^{th}$ Aug.-$27^{th}$ Sept. 2007. Result shows that Snoezelen room has some short-term positive effect on agitated behavior even though there was a considerable variation individuals responded. This result adds to the increasing evidence that Snoezelen could be a therapeutic environment for the elderly with dementia. Further research study, with larger number of participation, and a control group is required to establish more scientific evidence of Snoezelen effects on health outcome.

• Journal of Applied Biological Chemistry
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• 제58권3호
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• pp.209-218
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• 2015

Fructooligosaccharides have been mainly produced by microbial fructosyltransferases (FTase) enzymes. The present work focuses on the optimization of medium composition and cultivation parameters affecting FTase produced by Penicillium aurantiogriseum AUMC 5605 in shake flask cultivation. FTase production was optimized in two steps using DeMeo's fractional factorial design. A 1.46-fold increase in FTase production (105.4 U/mL) was achieved using the optimized culture medium consisting of (g/L): sucrose, 600; yeast extract, 10; $K_2HPO_4$, 5; $MgSO_4{\cdot}7H_2O$, 0.5; $(NH_4)_2SO_4$, 1.0 and KCl, 0.5. The obtained results showed that the maximum FTase enzyme activity was produced at initial cultivation pH values ranging from 6.0-6.5, at agitation speed of 200 rpm and using vegetative fungal cells as inoculum. Moreover, results showed that optimization of medium composition and some cultivation parameters resulted in an increase of about 93.7% in the enzyme activity than the nonoptimized cultivation conditions after 96 h of cultivation. Additionally, maximum production and specific production rates recorded 2340 U/L/h and 102 U/L/h/g cells, respectively.