Mesh형 내부전극을 사용한 2중 원통형 오존발생기의 온도 의존특성

전병준,이상근,송현직,박원주,이광식 영남대학교 공업기술연구소 1999 工業技術硏究所論文集 Vol.27 No.1

Nowadays, environment pollution caused by development of industrial society becomes a serious social problem. So, ozonized gas is suggested as a counter plan against the problem. In this paper, a double cylindrical type ozonizer has been designed and manufactured to improve ozone yield by cooling external electrode. The ozonizer equipped with three electrodes(central, internal and external electrodes) and two gaps. Discharge and ozone characteristics are described in this paper by varying flow rate( Q ) of oxygen suppling gas, temperature of cooling gas and supplied voltage.

미지 재래찰벼의 품종 특성 분석

전현식,이종옥 진주산업대학교 농업기술연구소 2006 農業技術硏究所報 Vol.19 No.-

식물의 형태적 분석을 통하여 미지 재래찰벼의 일반적인 품종특성을 알아보고자 연구되었다. 본 실험에서 “재래찰(Jaeraechal)”로 명명된 미지 재래찰벼와 일반메벼인 동진, 찰벼인 신선찰벼를 포함한 3품종을 비교실험에 사용하였다. 미지 재래찰벼는 동진벼와 신선찰벼에 비하여 발아율, 초기생장(최아), 벼 키와 이삭당 낟알수가 우수한 반면에 등숙비율, 종자의 장폭비, 천립중은 좋지 못했다. 광화학적 양자수율인 Fv/Fm는 세 품종간의 뚜렷한 차이가 없었다. This study was carried out to investigate common characteristics of unknown-native glutinous rice by analyzing plant architectures. Three rice cultivars, Dongjinbybeo which is non-glutinous rice, Sinsunchalbyeo which is glutinous rice, and unknown-native glutinous rice named as 'Jaeraechal' for this experiment were used to clarify some rice characteristics. Plant characteristics of unknown-Jaeraechalbyeo were superior to the others, Donjinybeo and Sinsunchalbyeo in germination rate, radicle growth, plant height and grain number per panicle, but they were inferior to the these in ripened grain ratio, seed length to width ratio and 1000-grain weight. Photochemical quantum yield, Fv/Fm, was entirely not different among Jaeraechabyeo, Donginbyeo and Sinsunchalbyeo at maturity.

단상 4중 멀티레벨 AC-DC 컨버터를 사용한 입력전류의 특성 개선

김천식,김은수,서기영,이현우 慶南大學校 附設 工業技術硏究所 2002 硏究論文集 Vol.20 No.-

본 논문은 입력전류 개선방법으로 buck 컨버터를 조합하여 컨버터의 입력전류를 계단파 형태로 제어하는 binary 조합을 이용한 단상 4중 Multi-level AC-DC 컨버터를 제안하고, 타당성을 시뮬레이션과 실험을 통하여 확인하였다. 동등한 용량의 AC-DC 컨버터를 중첩·다중화를 만들면 입력전원의 단위 역률 제어가 가능하고, 고속 스위칭에 따르는 문제를 저감시킬 수 있고, 필터가 불필요하게 되어 대용량화에 적용시킬 수 있는 등의 장점이 있다. This paper proposed the single phase quadruple multi-level AC-DC converter using binary combine which controls input current by combining buck converters to improve input current characteristic, and confirmed its validity throughout simulation and experiment. By multiplying and duplicating of AC-DC converter of equal capacity has the advantage of being able to control unit power factor of input current and reducing of the problem caused by high frequency switching, and appling to high power converter because filter is not necessary.

3중양분선택·개방형 CVM을 이용한 수도권 대기질의 편익가치

이해춘,정현식,김태영 한국환경경제학회 한국자원경제학회 2004 자원·환경경제연구 Vol.13 No.3

본 연구는 한국의 수도권 대기질 개선의 편익가치를 CV 방식을 통해 추정한 것이다. 분석에 사용한 질문 형식은 3중양분석택·개방형 질문이다 결과에 의하면, 최종 개방형 질문에서 표출한 WTP가 양분선택 과정에서 선택한 WTP 구간을 이탈한 경우가 다수 존재하였다. 이는 양분선택형 질문형식은 응답자의 잠재적 WTP를 추출하는 과정에서 편의가 발생함을 의미한다. 3중양분선택·개방형 질문 형식은 응답자가 양분 선택형 질문에 응답하는 과정의 학습 효과를 거쳐 개방형 질문에서 잠재적 WTP를 표출함으로써 개방형 질문의 응답률 저하라는 단점과 양문선택형에서 발생하는 편의를 감소시킬 수 있다는 이점이 있다. 수도권 대기질 개선의 편익가치, 즉 응답자가 사회적으로 바람직한 수준의 대기질 상태를 도달하기 위해 지불할 의사가 있는 금액은 응답자 가구 당 월평균 최소 1만 6,402원에서 최고 1만 9,494원으로 추정되었다. This paper is intended to valuate air quality of the Seoul Metropolitan Area using triple-bound dichotomous choice (TBDC) contingent valuation method (GYM), supplemented by open-ended (OE) questionnaires. In the OE questionnaires, some respondents would st i their willingness to pay (WTP) outside the limits of the WI`P interval. It implies that WTP es(intaees based on the customary dichotomous choice (DC) questionnaires can be biased. We argue that the TBDC-CVM refined with OE questions is more efficient, because the latter helps purge the former of corrupted data that may have been collected by the TBDC interview process.

휘발성 미량유기오염물질의 광분해에 관한 연구

이춘식,최장승,안종수,박현건,성낙창,박승조 동아대학교 환경문제연구소 1998 硏究報告 Vol.21 No.1

This study was carried out photolysis of Trace Volitile Organic Pollutants(BTEX) in the water. The experiment results were summarized as follows : 1. Benzene of removal efficiency were revealed 90% on illumination time of 20minute for bezene concentration range 0.01ppm-0.06ppm by 450W medium pressure mecury lamp of photon energy photolysis reaction, and were revealed 93% phomoxidaton on illumination time 30minute in 0.lppm of reactant benzene. Toluene of removal efficiency were revealed each 97.7%, 98.3%. 97.7%, 87.396 on illumination time of 20minute for toluene each of concentration 0.0lppm, 0.03ppm, 0.06ppm. 0.1ppm by 450W low pressure mecury lamp of photon energy photolysis reaction, and reactant toluene was disappeared on illumination time 30minute. 2. Ethylbenzene of removal efficiency get the better photolysis on the treatment contrast ethylbenzene with benzene and photolysis removal efficiency was above 90% in ethylbenzene concentration range 0.0lppm-0.lppm on illumination time l0minute. 3. Photolysis removal efficiency of m, p-Xylene were researched better result 93% on the about l0minute of illumination time m, p-Xylene concentration range 0.01ppm-0.06ppm, removal efficiency was 97% in higher concentration of 0.2ppm and illumination time 20minute. 4. Photolysis removal efficiency of o-Xylene were researched better result 95% on the about l0minute of illumination time m, p-Xylene concentration range 0.0lppm-0.lppm, and reactant o-Xylene was disappeared on illumination time about 20minute by 450W m d u m pressure mecury lamp.

菟絲子 의效能에 대한 硏究

진상식,황의현,김형창,김천수,오광수,한종현 한국전통의학연구소 2002 한국전통의학지 Vol.12 No.1

The purpose of this study is to determine the effect of Semen Cuscutae on phenylephrine(PE) and KCI induced contraction of isolated rat thoracic aorta. Contractile force was measured with force displacement transducer under 1.5 g loading tension. Contraction evoked by PE (ED_(50)) was relaxed significantly by Semen Cuscutae. The mean percent relaxing of PE induced contraction was 60.6% (p<0.01) after 300 ㎕/㎖ Semen Cuscutae, but the mean percent contraction of KCI induced contraction was 10.4% (p<0.05) after 300 ㎕/㎖ Semen Cuscutae. Vasorelaxation by Semen Cuscutae was significantly reduced after with and without endothelial cells. Pretreatment of aortic rings with L-NAME (100 μM), a nitric oxide synthase inhibitor, indomethacin (3 μM), an inhibitor of cyclooxygenase, methylene blue (10 μM), guanylyl cyclase inhibitor, propranolol (1 μM), a β-adrenoceptor antagonist, atropine (1 μM), a muscarinic receptor antagonist and diltiazem (10 μM), a Ca^(2+)-channel blocker was recovered the effect aorta. These results indicate that Semen Cuscutae can relax EP induced contraction of isolated rat thoracic aorta and that this increasing contraction related to epithelium and various effect.

수술실 오염도감소를 위한 수술실공조시스템에 대한 연구

김천숙,박은정,강규식,김지은,안기량,권진형,유시현,주영철,권순정 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.1

Background: The OR(operating room) should provide an optimum environment that is safe for the patient and the working personnel. The air ventilation system of OR has been studied to decrease the contamination of air. We investigated the flow and contamination of the air in OR at our hospital. Method: Cultures in OR were made and the number of bacteria and fungi were calculated. A two-dimensional model for the cross-section of an operation room is developed for the CFD (computational fluid dynamics) analysis. The characteristics of air flow in the empty operation room and in the occupied operation room are calculated by using a CFD program. Results: The current air ventilation system of our hospital does not deliver the clean air to the operating site efficiently in occupied OR. Conclusions: We suggested a new location of air ventilation system which improves air venting with little increase of the cost of equipment.

누두흉 환자에서 Nuss 금속막대 제거 전 · 후 폐 역학 변화

강규식,백남순,김천숙,안기량,권진형,김지은,유시현 순천향의학연구소 2003 Journal of Soonchunhyang Medical Science Vol.9 No.1

Nuss operation is one of the surgical procedure for pectus excavatum and it's method is the insertion of convex steel bar under the sternum through small bilateral thoracic incision. As the patients is growing, the thorax can be compressed gradually by steel bar. So Nuss bar needs to be removed two years after Nuss operation. This study was undertaken to assess the effect on the repiratory mechanics before and after the removal of the Nuss bar. Twenty patients with previous Nuss operation were allocated for the removal of Nuss bar. Lung mechanics (dynamic lung compliance, static lung compliance, and airway resistance), hemodynamic change (heart rate, systolic pressure, and diastolic pressure), and pulmonary gas exchange (arterial oxygen tension, arterial carbon dioxide tension, pulse oximeter saturation, and end tidal carbon dioxide tension) were measured before and after removal of Nuss bar. Respiratory mechanics (dynamic and static lung compliance, inspiratory airway resistance), pulmonary gas exchange and hemodynamic parameter were unchanged before and after the removal of Nuss bar. We concluded that lung mechanics were not changed before and after the removal of Nuss bar in the patients with pectus excavatum and the 95% patients were satisfied with operation.

무기이온을 광증감제로 사용한 유해물질의 광분해

이춘식,김영희,박현건 진주산업대학교 1999 산업과학기술연구소보 Vol.- No.6

Photodegradation of benzene, carbaryl and aldrin were conducted with persulfate, nitrate and nitrite ion as sensitizers in aqueous solution. Persulfate and nitrate ions were proved to be effective to enhance the photodegradation of hazardous compounds. The sensitizing effect increased with increasing persulfate concentration, while nitrate ion showed the greatest sensitizing effect at 5㎎/l. In the case of the nitrite ion, no significant enhancement effect was observed, on the contrary, inhibited the photodegradation of hazardous compounds. With increasing nitrite concentration, photodegradation of hazardous compounds ran through a maximum value and decreased there after with increasing nitrite concentration.

남강의 수중보에서 발생하는 이취미 물질에 관한 연구

이춘식,박현건 한국환경과학회 2002 한국환경과학회지 Vol.11 No.4

This study was designed to analyse the odor from Nam river The characteristic odor in the water occurred from geosmin and phenol, p-cresol and indol were detected from sediment/water samples. The others were detected as alcohols and fat acid compounds. Algae causing odor and taste were identified as Oscillatoria sp. and Synedra acus. 15 species of phytoplankton, a zooplankton, an eelworm and chironomus were identified in water/sediment sample.