• 동의생리병리학회지
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• 제16권6호
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• pp.1151-1156
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• 2002

This research was done to make the effective prescription and cope with various senile dementia. Sprague-Dawley rats were injured by ibotenic acid to make a damage on learning and memory functions of model rats. At first acquisition test and retention rest were done in the Morris water maze. And to evaluate the effects of the sample drug(GSD) on choline acetyltranferase and acetylcholine esterase, immunoreactive measurement and enzymatic activity measuring were carried out. The ibotenic acid were injected to hippocampus CA1 and CA3 area. Conclusion : GSD improved the learning ability in the acquisition test and memory function in the retention test significantly. And GSD increased the level of ChAT which is synthesizing acetylcholine in CA1 area, and at the same time it increased the level of AChE which is resolving acetylcholine. These results show that GSD improved the cholinergic catabolism and anabolism, and the increment of metabolic activity of cholinergic system. In other words, it contributes to the recovery of damaged learning and memory function by ibotenic acid. So it can be concluded that GSD will be helpful to cholinergic brain damage induced by primary or senile reduction of acetylcholine secretive activity.

• Nuclear Engineering and Technology
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• 제32권4호
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• pp.379-394
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• 2000

As an in-vessel retention (IVR) design concept in coping with a severe accident in the nuclear power plant during which time a considerable amount of core material may melt, external cooling of the reactor vessel has been suggested to protect the lower head from overheating due to relocated material from the core. The efficiency of the ex-vessel management may be estimated by the thermal margin defined as the ratio of the critical heat flux (CHF）to the actual heat flux from the reactor vessel. Principal factors affecting the thermal margin calculation are the amount of heat to be transferred downward from the molten pool, variation of heat flux with the angular position, and the amount of removable heat by external cooling In this paper a thorough literature survey is made and relevant models and correlations are critically reviewed and applied in terms of their capabilities and uncertainties in estimating the thermal margin to potential failure of the vessel on account of the CHF Results of the thermal margin calculation are statistically treated and the associated uncertainties are quantitatively evaluated to shed light on the issues requiring further attention and study in the near term. Our results indicated a higher thermal margin at the bottom than at the top of the vessel accounting for the natural convection within the hemispherical molten debris pool in the lower plenum. The information obtained from this study will serve as the backbone in identifying the maximum heat removal capability and limitations of the IVR technology called the Cerium Attack Syndrome Immunization Structures (COASISO) being developed for next generation reactors.

• 한국간호교육학회지
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• 제18권1호
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• pp.102-110
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• 2012

Purpose: The purpose of this study was to evaluate the effects of BLS training in nursing students and their retention period. Methods: The participants were 48 nursing students enrolled in M University in Mokpo. Data were collected from September, 2009 through September 2010. Nursing students were tested for their knowledge, attitude, confidence before, immediately after, 4 weeks after, 8 weeks after, 6 months after, and 1 year after BLS training. In addition, their knowledge and skill of cardiopulmonary resuscitation were tested 5 times. Data were analyzed using the SPSS/PC 12.0 statistical program Results: Knowledge, attitude and confidence were significantly increased immediately after compared to before BLS training. Knowledge and confidence 6 months after, and attitude, performance ability and technical precision for ventilation and compression 4 weeks after BLS training were significantly decreased compared to immediately after. Conclusion: Overall retention of BLS training effects among nursing students, without reinforcement, decreases significantly after six months following initial training. BLS training in nursing students should be repeated every six months, especially performance training of BLS should be repeated every 4 weeks. In addition, to maintain the knowledge and skills of BLS, appropriate renewal time of certification and improvement of training programs are necessary.

• Journal of Korean Society for Atmospheric Environment
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• 제21권E2호
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• pp.41-48
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• 2005

A novel hybrid system composed of a biotrickling filter and an activated sludge reactor was investigated under the conditions of four different SRTs (sludge retention times). The performance of the hybrid reactor was found to be directly comparable among the four different sludge ages. Discernible differences in the removal performance were observed among four different SRTs of 2, 4, 6, and 8 days. High removal efficiency was achieved by continuous circulation of activated sludge over the immobilized mixture culture, which allowed on pH control, addition of nutrients, and removal of paint VOCs (volatile organic compounds). The results also showed that the removal efficiency for a given pollutant depends on the activity of microorganisms based on the SRT. As the SRT increased gradually from 2 to 8 days, the average removal performance decreased. The highest removal rate was achieved at the SRT of 2 days at which the highest OUR (oxygen uptake rate), $6.1mg-O_2/liter-min$ was measured. Biological activity in the recycle microbes decreased to a much lower level, $3.6mg-O_2/liter-min$ at a SRT of 8 days. It is thus believed that young microorganisms were more active and more efficient for the VOCs removal of low concentrations and high flow rates. The apparent correlation of $R^2=0.996$ between the average removal efficiency and the average OUR at each SRTs suggests that VOCs degradation by young cells significantly affected the overall removal efficiency for the tested SRTs.

• 대한핵의학회지
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• 제21권1호
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• pp.5-8
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• 1987

Nineteen patients with progressive systemic sclerosis were underwent radioisotope esophageal transit study (RIETS) which revealed abnormal transit time and/or pattern in 16 (84.2%). Among them 12 showed to and fro movement of RI and 4 showed retention of it. Abnormal esophageal transit was not related with Raynaud phenomenon. After intravenous administration of metoclopramide (10 mg), percent retention of RI in distal 2/3 of esophagus was significantly reduced (p<0.05).

• 한국간호교육학회지
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• 제16권2호
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• pp.222-228
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• 2010

Purpose: This study was done to examine the effects and retention of the American Heart Association (AHA)'s basic cardiac life support (BLS) training on knowledge and skills of nursing college students. Method: The study was a one group pretest-posttest experimental design. The sample included 41 junior nursing students from D college who participated in an AHA BLS course for healthcare providers in K hospital from January 18 to June 7, 2010. The instruction was based on ‘BLS knowledge and skills'. The data were analyzed with paired t-test using the SPSS/PC 12.0 win. Result: First, knowledge (t=-7.648, p=.000) and skills (t=-12.988, p=.000) were significantly increased immediately after BLS training. Second, knowledge (t=4.098, p=.000) and skills (t=50.350, p=.000) of BLS after 4 months was significantly decreased compared to right after BLS training. Conclusion: Knowledge and skills were decreased 4 months after BLS training. Therefore, retraining in BLS is required within 4 months. To maintain the knowledge and skills of BLS, appropriate renewal time and retraining programs are needed.

• Nuclear Engineering and Technology
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• 제47권3호
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• pp.351-361
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• 2015

External reactor vessel cooling (ERVC) for in-vessel retention (IVR) has been considered one of the most useful strategies to mitigate severe accidents. However, reliability of this common idea is weakened because many studies were focused on critical heat flux whereas there were diverse uncertainties in structural behaviors as well as thermal-hydraulic phenomena. In the present study, several key factors related to molten corium behaviors and thermal characteristics were examined under multi-layered corium formation conditions. Thereafter, systematic finite element analyses and subsequent damage evaluation with varying parameters were performed on a representative reactor pressure vessel (RPV) to figure out the possibility of high temperature induced failures. From the sensitivity analyses, it was proven that the reactor cavity should be flooded up to the top of the metal layer at least for successful accomplishment of the IVR-ERVC strategy. The thermal flux due to corium formation and the relocation time were also identified as crucial parameters. Moreover, three-layered corium formation conditions led to higher maximum von Mises stress values and consequently shorter creep rupture times as well as higher damage factors of the RPV than those obtained from two-layered conditions.

• Journal of Information Technology Applications and Management
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• 제26권4호
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• pp.1-18
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• 2019

The virtual reality (VR) is an immerging technology used in the serious games industry to treat psychological disorders like dementia. We created a system named as Virtual Reality Home (VRH) for the elderly who lived with Alzheimer's disease (or other form of dementia) and cognitive impairment using virtual reality technology. The purpose of our study is to measure the long-time immersion and retention of VRH on the moods and apathy, enhancement in physical and brain stimulation as well as a decision making with peoples of dementia and explore the experience of aged care home staff's member. The VRH shows a positive impact on the elderly participants and staff members. During the VRH experience, excitement and a great level of alertness were observed among the participants but few of them were feeling anxiety. Furthermore, we observed the improvement in physical, memory and brain stimulation, but the participants have a low focus on decision making because they wanted to explore all interactable objects in the VRH. This study suggests that the VR may have the potential to improve the quality of life, and these results can assist to expand the future development in the enhancement of efficiency of people with dementia.

• 한국양식학회지
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• 제10권4호
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• pp.435-438
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• 1997

전기분해를 이용한 해수의 암모니아성 질소 및 대장균 제거에 효과적이었다. 암모니아의 제거효율은 전류의 세기가 클수록, 반응 시간이 길수록, 극판간격이 좁을수록 증가하였다. 해수내 250/100 m\ell$의 대장균은 모든 실험 조건에서 검출되지 않아, 살균 목적으로 전기분해가 매우 효과적이었다. 암모니아의 제거 효율은 잔류 염소의 농도에 따라 증가하였다. 암모니아의 제거 효율과 잔류 염소와의 관계는 다음과 같다.$NH_4^+-N(%)=4cdotlog[Residual\;chlorine(mg/\ell)+28(r=0.892)$

• Membrane and Water Treatment
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• 제6권6호
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• pp.489-499
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• 2015

In this work, treatment of real hypersaline refinery wastewater by hollow fiber membrane bioreactor coupled with reverse osmosis unit was studied. The ability of HF-MBR and RO developed in this work, was evaluated through examination of the effluent properties under various operating conditions including hydraulic retention time and flux. Arak refinery wastewater was employed as influent of the bioreactor which consists of an immersed ultrafiltation membrane. The HF-MBR/RO was run for 6 months. Average elimination performance of chemical oxygen demand, biological oxygen demand, total suspended solids, volatile suspended solids, total dissolved soild and turbidity were obtained 82%, 89%, 98%, 99%, 99% and 98% respectively. Highly removal performance of oily contaminant, TDS and the complete retention of suspends solids implies good potential of the HF-MBR/RO system for wastewater refinement.