• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.1
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• pp.95-103
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• 1999

Low pressure combustion characteristics of the composite solid propellants were studied in terms of the propellant burning rate, ignition processes, and the structure of the extinguished surfaces. Optical Vacuum Strand Burner(OVSB) system was designed and configured for this purpose. Burning rates of the propellants were measured at subatmospheric pressure by developed test method in OVSB. The ignition and combustion phenomena of the studied propellants in the combustion chamber of OVSB were recorded and analyzed with the camera and VCR(30 frames/s). Burning surfaces of the propellants were extinguished by rapid depressurization method and analyzed with Scanning Electron Microscope(SEM).

• The Korean Publising Journal, Monthly
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• s.134
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• pp.15-15
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• 1993

'한국의 자연탐험'은 우리나라에 서식하는 동식물들의 자연생활사를 생생한 사진과 간명한 문장으로 그려낸 일종의 생태사진집이다. 최근 제1차분 55권을 선보인 이 책은 모두 70여 항목에 이르는 목록구성의 방대함과 충실성, 그리고 그것을 제대로 소화해내기 위해 기울인 출판사와 필자들과 사진작가들의 노력이 특히 높게 평가되고 있다.

• Vending industry
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• v.11 no.2
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• pp.46-47
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• 2012

편의점에서 감기약 등의 안전 상비 의약품 판매를 허용하는 약사법 개정안이 지난 5월 2일 국회를 통과해 올 11월 말부터는 전국 2만여 개의 24시간 편의점에서 상비약을 살 수 있게 됐다. 휴일과 야간에도 손쉽게 감기약과 소화제, 해열제 등을 구입할 수 있어 소비자 입장에선 한결 편리해진다. 이 시점에서 관심사가 되고 있는 게 자동판매기를 통해서도 판매가 가능한지 여부이다. 만약 자동판매기로도 유통이 될 수 있다면 새로운 영역이 열린다. 새로운 시장 발굴에 어려움을 겪는 산업계 입장에서 보면 호재가 아닐 수 없다. 과연 그 가능성은 얼마나 될까?

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.1
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• pp.51-57
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• 2014

Purpose: The present study was conducted to establish the experimental condition for the proper evaluation of protein removal efficacy when developing protein removal agents. Its protein removal efficacy was further analyzed and compared with the result from protein removal efficacy against protein deposition on contact lens to suggest the evaluation method for efficacy of protein removal agents. Methods: Protein digestibility assay presented in the Korean pharmacopoeia was selected to establish the evaluation method for efficacy of papain, pancreatin, subtilisin A and protease itself as a ingredient and protein removal tablets or solution containing those enzymes and find a suitable test conditions. Furthermore, the cleaning efficacy of commercially available protein removal tablets and solution on balafilcon A lens deposited with protein artificially was measured and the correlation between two evaluation methods was further analyzed. Results: When pancreatin itself and the product containing pancreatin was evaluated by protein digestibility assay, both reached 28 IU/mg, the standard value of protein digestibility suggested by the Korean pharmacopoeia. In case of protease and subtilisin A tested with trichloroacetic acid B solution, both of them met the enzyme activity level proposed by the manufacturers when they were evaluated by protein digestibility assay however, papain and subtilisin A tested with trichloroacetic acid A solution were not reached the enzyme activity level. Among protein removal agents, three products except a product containing pancreatin did not meet the enzyme activity value specified by the manufacturer when they were evaluated by protein digestibility assay. However, actual protein removal efficacy of three products except a papain-containing product on the lens was greater than 90% protein removal. In the case of papain-containing protein removal product, its effect was not measured by protein digestibility assay however, its actual protein removal efficacy on the lens reached 73.72%. Conclusions: From the results, it was confirmed that the efficacy of protein removal agents for contact lens should be evaluated by different method according to the type of proteolytic enzyme contained. That is, the protein removal agents containing pancreatin, protease and subtilisin A can be evaluated by protein digestibility assay and protein removal efficiency evaluation and the products containing papain can be effectively evaluated by only the evaluation method for protein removal efficiency employing the lens.

• Korean Journal of Poultry Science
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• v.34 no.3
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• pp.217-222
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• 2007

This study was conducted to investigate the effects of mud flat bacteria origin protease supplementation by crude protein level on growth performance, nutrient digestibility, total protein and BUN (blood urea nitrogen) concentration in broilers. A total of four hundred eighty broilers were randomly allocated into four treatments with six replications for five weeks. Dietary treatments included 1) high crude protein diet, 2) high crude protein diet + 0.1% protease, 3) low crude protein diet and 4) low crude protein diet + 0.1% protease. During the entire experimental period, weight gain and feed/gain were improved in treatments of high crude protein diets and low crude protein diet added protease compared with treatment of low crude protein diet without protease (P<0.05). Similarly, DM digestibility was also improved in treatments of high crude protein diets and low crude protein diet added protease compared with treatment of low crude protein diet without protease (P<0.05). N digestibility was improved in treatment of high crude protein diet added protease compared with low crude protein diet without protease (P<0.05). Total protein concentration in blood was increased in treatment of high crude protein diet without protease compared with other treatments (P<0.05). In conclusion, mud flat origin protease was effective in improving weight gain, feed/gain and nutrient digestibility, and influenced blood total protein in broilers.

• Journal of the Korean Society of School Health
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• v.3 no.1
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• pp.101-118
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• 1990

This study was intended to investigate actual conditions and problems relating to a variety of substance which have been used by students. A Questionnaire survey was carried out with the subject of 2411 students in an academic boys' high school, academic girls' high school, technical boys' high school and technical girls' high school in Pusan, from the 15th day to 29th day of March, 1989. The summarized results were as follows. There was not a remarkable difference in distribution of these subjects in boys' & girls' high school. The common and good health condition of subjects accounted for 90 percent or higher. 24.4 percent of them also had smoking experience, 11.6 percent of which continues to smoking. The understanding rate of these substances name other than sedative, psychostimulants and antihypnotic accounted for 90 percent or higher. The experience rate taking these substances for one year showed that anodyne, digestive and nutritive tonic accounted for 70 percent, antihypnotic for 15.6 percent, sedative for 1.4 percent, respectively, and psychostimulants for 0.5 percent. Moreover. it was shown that drugs accounted for 1.5 percent, bond for 1.4 percent, and thinner for 0.5 percent. The rate of the daily experiencers who took anodyne, digestive, nutritive tonic, sedatives, and psychostimulants and so on was 7.7 percent, 6.2 percent, 5.2 percent, 5.9 percent, and 5.0 percent respectively. This fact implied that there was a serious problem in high school students' non - narcotic abuse. The usage rate of these substances for treatment purpose showed that anodyme accounted for 90 percent or higher, and digestive for 70-80 percent, respectively, where girl students showed higher rate than one of boy students. Additionally, there was higher the usage rate for other purposes. The usage rate of drugs was highest when these students felt melancholy and curiousity. Their obtaining place appeared that these students mainly obtained these drugs, bonds and thinners from a small shop or peddler and their friend while they usually obtained other substance from the pharmacy and medical institute. The first usage time of these substances appeared during the middle school (the age of 14-15) which was the highest rate. The smoker of all subjects used remarkly large substances as compared with one of no-smoker. Particularly, it appeared that the usage of drugs was very closely related to smoking. The large number of students did not use these substances for oesrable purposes even though they understood the name of these substances. For this reason, from primasy schools it is required to teach the students dependence and harmful effects caused by these substances abuse. Moreover, it was shown that these students firstly used these substances during the middle school (the age of 14-15)due to curiosity. As a result, it is very urgent to give the students health education suitabale for prevention of these substance abuse, when considering harmful effects of these substances. And so health education for no-smoking. Finally, considering that it is very easy to obtain these substances from a small shop and pharmacy, the regulation of these substances control should be considered and completed in the future.

• Fire Science and Engineering
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• v.34 no.2
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• pp.147-155
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• 2020

This paper presents a study on the development of a fire extinguishing agent and extinguishing system for an energy storage system (ESS) fire. The fire extinguishing agent designed to extinguish an ESS fire is a highly permeable fire extinguisher that reduces the surface tension and viscosity while bringing about cooling action. This is the main extinguishing effect of this type of wetting agent, which displays the characteristics of fire extinguishing agents used for penetrating the battery cells inside the ESS module. For the fire extinguishing system, a local application system was designed to suppress fire on a rack-by-rack basis. A 360° rotating nozzle was inserted into the rear hall of the ESS module, and general nozzles were installed in the rack to maximize the fire extinguishing effect. The fire extinguishing agent was strongly discharged by virtue of the gas release pressure. Experiments on fire suppression performance with ESS module 1 unit and module 3 units showed that all visible flames were extinguished in 8 s and 9 s, respectively, by the fire extinguishing agent. In addition, based on confirming reignition for 600 s after the fire extinguishing agent was exhausted, it was confirmed that the ESS fire was completely extinguished without reignition in all fire suppression performance experiments.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.153.2-153.2
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• 2010

화력발전 분야에서 $CO_2$ 분리는 크게 연소전 탈탄소화(pre-combustion capture)와 연소후 포획(post-combustion capture)으로 나누어진다, 연소후 포획은 연료를 연소한 후 발생하는 $CO_2$와 $N_2$가스에서 $CO_2$를 분리하는 기술로 흡수나, 흡착, 막분리 등을 주로 이용한다, 연소전 탈탄소화는 연소 전에 $CO_2$가 발생되지 않도록 하는 기술로써, 부분 산화나 개질 및 수성가스 변위반응 등이 포함되며 생성된 $H_2$와 $CO_2$를 분리하여 수소를 생산하는 기술($CO_2/H_2$분리가 핵심)이다. 우리나라는 대부분 연소후 포획 위주로 많은 연구가 진행되어 왔다, 하지만 최근 고유가 시장이 형성되면서 석탄화력 발전 및 복합가스발전(IGCC)에 필요한 연소전 탈탄소화($H_2/CO_2$ 가스로부터 $CO_2$ 회수) 연구에 산업적 관심이 급상승되고 있다. 특히, 연소전 탈탄소화 과정에서는 높은 자체압력(약 2.5 - 5.0MPa)과 비교적 높은 농도의 $CO_2$(약 40%의)가 발생되기 때문에, 연소전 탈탄소화는 가스하이드레이트 형성/분해 원리가 가장 잘 적용될 수 있는 기술이라 할 수 있다. 본 연구에서는 가스 하이드레이트 형성원리를 이용하여 정온 정압 조건에서 $CO_2/H_2$ 하이드레이트를 제조하였으며 특히, 하이드레이트 형성 촉진제인 THF(Tetrahydrofuran)와 TBAB(Tetra-n-butyl ammonium bromide)를 첨가하여 각각 0.5, 1, 3mol% 농도에 따른 상평형 및 속도론 실험을 수행 하였다. 또한 라만 분석을 통하여 $CO_2$ 회수 분리에 대한 연구도 병행하였다. 이러한 연구는 연소전 탈탄소화 기술에서의 $CO_2$ 회수 분리에 대한 핵심 연구임과 동시에 탄소배출권 규제에 실질적인 기여를 할 수 있을 것으로 사료된다.

• Tuberculosis and Respiratory Diseases
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• v.62 no.4
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• pp.284-289
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• 2007

Background: To define the clinical features of patients with lung and upper aerodigestive tract cancer through a review of the histopathology, clinical features and follow-up results. Methods: Patients with lung and upper aerodigestive tract cancer who were diagnosed in Young dong Severance Hospital from 1992 to 2005, were retrospectively reviewed. The clinical data, radiologic findings, pathologic findings, treatment modalities were evaluated. Result: There was a total of 20 patients with aerodigestive tract cancer who were diagnosed with lung cancer over a 13 years period. The mean age was $58.45{\pm}15.09$ years and 19 cases were male. There were 14 smokers with an average pack year of 46 years. Twelve patients had aerodigestive tract cancer and later developed lung cancer, and 5 lung cancer patients were later diagnosed with aerodigestive tract cancer. Conclusion: These results suggest that cancers of the aerodigestive tract and lung can arise as either dependent or independent events and most aerodigestive tract cancer patients who developed lung cancer are not treated properly. Therefore, regular low dose chest CT with close suspicion is needed to properly manage upper aerodigestive tract cancer patients.

• Monthly Korean Chicken
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• v.18 no.2
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• pp.122-127
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• 2012

계사내 공기중의 암모니아 농도 감소 목적으로 식물 기원 소화율 촉진제(phytogenic digestibility enhancer) 사용이 가능하다. 이 소화율 촉진제는 사료 설계 명세서 내 특정 성분(조단백질)을 감소시키고 영양소 이용성을 개선하여 동물생산성을 향상시키기 때문이다. 조단백질 함량이 낮은 사료 급여는 가금에게 적정 요구량 이상 흡수된 단백질(excess protein)의 뇨산(尿酸 : uric acid) 전환에 에너지를 소비하지 않아서 열역학적 이점(熱力學的 利點 : energetic advantage)이 있고, 이 에너지는 유익한 성장에 사용이 가능하도록 존재한다. 더욱이 동물 사료 중 조 단백질 1%는 약 3% 더 많은 물의 섭치가 필요하고, 그 중 80%는 다시 배설되므로 단백질 함량 적정화 사료들(protein optimized diets)은 음수 요구량을 감소시킨다. 이러한 단백질 적정화 사료는 동물 사육업자들에게 관심의 대상으로 명확한 경제적 이득이 발생한다.