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.

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.

분사식 주사기를 이용한 소아환자의 국소마취

이재춘,김대업,이광희,김성형,양계식 大韓小兒齒科學會 2001 大韓小兒齒科學會誌 Vol.28 No.4

소아치과에서 국소마취는 공포의 대상이며, 특히 행동조절이 힘든 소아의 경우 더욱 그러하다. 국소마취에 대한 공포는 주사침의 자입시나 주사액의 주입시 느끼는 동통 만큼이나 주사침 자체의 공포도 크게 차지한다. 주사침 자입시의 동통을 완화하기 위하여, 도포마취제 등이 개발되었으나 이들은 국소마취의 동통을 완화시키는 면은 있으나 주사침 자체에 대한 공포를 없애지는 못하였다. Syrijet Mark Ⅱ??(Mizzy Inc, USA)는 주사침이 없는 치과용 분사식 주사기(jet injection device)로서 소아에서 주사침에 대한 공포를 성공적으로 감소시킬 수 있다고 알려져 있다. 저자들은 여러 행동등급의 소아를 대상으로 Syrijet을 사용하여 국소마취를 시행한 후 동통평가의 척도로서 VAS(visual analogue scale)를 소아에게 적합하게 색생화한 CAS(color analogue scale)을 이용하여 국소마취시의 동통수준을 측정한 결과, 기존 주사침에 의한 국소마취시 보다 국소마취의 동통이 감소된 것을 알 수 있었다. Syrijet의 장점으로는 주사침이 없다는 점, 기존의 술식에서 일회용이었던 미취용 카트리지를 재사용할 수 있다는 점, 신경 및 혈관에 안전하다는 점 등이 있었으며, 단점으로 부피가 크며, 가격이 비싸며, 사용시 숙련성을 요구한다는 점 등이 있었다. Local anesthesia procedure in pediatric dentisty using needle-tipped syringes is stressful and painful for the child patients. The Syrijet Mark Ⅱ (Mizzy Inc. USA) is a jet injection instrument, which uses high pressure to propel fluids into soft tissue without the use of a hollow neeldle, so it seems to be able to reduce the injection phobia of the child patients. The authors compared the Syrijet with the conventional syringe by assessing the pain level after local anesthetic procedures using CAS(color analogue scale) which was developed from VAS(visual analogue scale). The result showed that the pain was reduced by the use of syrijet. The advantages of syrijet were no use of neeldes, the reuse of the anesthetic cartridge, and the safety to nerves and vessels. The disadvantages were the large size, the high price, and the need of skill to use.

저항을 이용한 프로판-공기 혼합가스의 점화한계 개선에 관한 연구

이춘하,오종용,옥경재,지승욱,이광식,심광렬 한국화재소방학회 2004 한국화재소방학회논문지 Vol.18 No.1

본 논문은 IEC형 불꽃점화 시험장치를 이용하여 저압 유도회로의 최소 점화한계를 프로판-공기 5.25 Vol.%의 혼합 가스에 대하여 실험적으로 구하였으며, 또한 유도회로의 인덕턴스 L에 안전소자로서 저항을 병렬접속하였을 경우 프로판-공기 5.25 Vol.%의 혼합 가스에 대한 점화한계 개선효과를 관찰하였다. 그 결과, 최소 점화한계는 전류의 크기에 따라 좌우되었다 또한, 전원으로부터 공급되는 에너지는 인덕턴스에 우선 축적되고. 그 초과분의 에너지가 폭발성 가스의 점화원으로 작용하였다. 점화한계 개선효과는 인덕턴스가 300 mH일 때, 최고 330%의 개선효과가 나타났으며 인덕턴스가 클수록 점화한계 개선효과가 크게 나타났다. 또한 병렬로 접속한 저항의 크기가 적을수록 점화한계 개선 효과가 크다. 본 연구결과는 본질안전 방폭형 전기기기의 연구개발을 위한 기본자료로 활용할 수 있을 뿐만 아니라 이들 기기의 방폭성능에 대한 시험자료로도 활용이 가능할 것으로 사료된다. This paper describes the minimum ignition limits for propane-air 5.25 Vol.% mixture gases in low voltage inductive circiuts. The improved effects on the ignition limit are studied by parallel safety components(resistors) for propane-air 5.25 Vol.% mixture gas in low voltage inductive circuits. The experimental devices used in this test are the IEC type spark ignition test apparatus. The minimum ignition limits are controlled by the values of current in inductive circuit. Energy supplied from elect source is first accumulated at the inductance, it's extra energy is working as ignition source of the explosive gas. The improved effects on the ignition limit are respectively obtained as the maximum rising rate of 330% by composing parallel circuits between inductance and resistor as compared with disconnecting inductance with the safety components. The more values of inductance increase the higher improved effects of ignition limit rise. The less values of resistor the higher improved effects of ignition limit rise. It is considered that the result can be used for not only data for researches and development of intrinsically safe explosion-proof machines which are applied equipment and detectors used in dangerous areas but also for datum for its equipment tests.

건전지의 본질안전 방폭성 평가에 관한 연구

지승욱,이광식,이동인,박원주,이춘하,김하호 嶺南大學校 工業技術硏究所 1997 工業技術硏究所論文集 Vol.25 No.1

Ignitability of explosive gas mixture by spark of dry cell in case of short circuit by accident was studied for the purpose of evaluation of intrinsically safe characteristics of dry cell that manufactured in Korea. IEC type spark test apparatus, 21±2[vol%] of hydrogen-air mixture, and dry cell that produced in Korea was used for the experiment. The result of this research could be used for design, manufacturing and using the intrinsically safe electrical apparatus.

관개방법에 따른 논에서의 수문 및 수질특성에 미치는 영향

전지홍,윤춘경,최진규,윤광식 한국육수학회 2005 생태와 환경 Vol.38 No.1

관개방법이 논에서의 수문 및 수질특성에 미치는 영향을 파악하기 위하여 관개용수가 풍부한 지표수 관개지역과 관개용수가 부족한 지하수관개지역에서의 물수지 및 영양물질수지 분석을 실시하였다. 지표수 관개논은 영농기간동안 지속적으로 관개가 이루어졌으나, 지하수 관개논은 영농초기에만 이루어졌으며 그 이후에는 강우에 의해 담수심이 유지되어 지표유출은 지표수 관개논에 비해상대적으로 낮은 빈도를 나타내었다. 지표수의 영양물질 농도는 시비에 의해 크게 영향을 받는 것으로 나타났으며, 특히 다량의 시비가 이루어지는 영농초기(5~6월 중순)에는 높은 영양물질 농도를 나타내어 이 시기에 논에서 유출이 이루어진다면 하류 수계에 영향을 줄 것으로 판단되었다. 물수지 분석결과 지하수 관개논의 관개량, 지표유출량 등이 상대적으로 지표수 관개논에 비해 낮은 값을 나타내었다. 영양물질수지분석 결과 대부분의 유입은 시비에 의해 이루어졌으며, 유출은 지표유출이 많은 비중을 차지하였으나 지표유출과 침투유출사이의 비율은 토양의 특성에 좌우되는 것으로 판단된다. 외부에서의 유입을 제외하고 시스템내에서의 유출입만 고려한다면, 물관리가 효율적으로 이루어진 지하수 관개논에서 낮은 부하량을 나타내었다. 그러나 기비가 이루어지고 인위적인 낙수나 강우에 의한 유출이 발생할 경우, 높은 부하량 뿐만 아니라 고농도의 영양물질질이 수계로 유입되는 것으로 나타났다. 논에서의 비점오염관리를 위한 대안으로 현재 시행되고 있는 시비량 감소 뿐 아니라, 효율적인 물관리기법 개발이 포함되어야 할 것으로 판단된다. 특히 영농초기의 강우특성과 논에서의 담수기능을 고려해 볼 때 시비에 의한 높은 영양물질 농도를 나타내는 논 표면수의 유출을 효율적으로 억제할 수 있을 것으로 판단된다. 물꼬높이의 증가와 천수간단관개 영농초기의 강우에 의한 유출을 억제시킴으로써 부족한 관개용수의 절약 뿐만아니라 하류수계의 수질보호에 기여를 할 것으로 판단되며, 다양한 조건에 따른 환경적인 측떤 뿐 아니라 벼의 생리적인 측면은 장기적인 모니터링을 통해 반드시 고려되어 야 할 것이다. The comparison of water balance and nutrient loading from paddy field with different irrigation management were carried out during 1999-2002 at two different sites; one is irrigated with groundwater and the other is irrigated with surface water. For the surface water irrigated paddy field, irrigation was performed continuously during growing season. Whereas, initial irrigation with groundwater was applied during initial growing season, and the ponded water depth was maintained by natural precipitation since initial irrigation. The runoff frequency of groundwater irrigated paddy field was less than that of surface water irrigated paddy field. The nutrient concentration of ponded water was high by fertilization at early cultural periods, so reducing surface drainage during fertilization period can reduce nutrient loading from paddy fields. Amount of irrigation water to surface water irrigated paddy field was higher than to groundwater irrigated paddy field and evapotranspiration was similar because it is influenced by climate. Overall input in and output from paddy field irrigated with goundwater were less than that with surface water. This study indicate that efficient water management can reduce surface drainage outflow, save water, and protect water quality. It might be important BMPs for paddy field.

흰쥐 재생간의 알콜대사효소들의 활성치

문교철,곽춘식,정성광,김여희 啓明大學校 醫科大學 1988 계명의대학술지 Vol.7 No.2

A study was made on the change in the activities of the following during 10 post-operative days: alcohol dehydrogenase of regenerating rat livers after 70% (median and left lateral lobes) partial hepatectomy. After partial hepatectomy in the rats, activities of regenerating liver alcohol dehydrogenase significantly increased in the sixth day. The activities of microsomal ethanol-oxidizing system in the regenerating liver markedly increased from the third day after partial hepatectomy. However, no significant changes in hepatic catalase was noted throughout the experiments. The activities of cytosolic and microsomal aldehyde dehydrognease in the regenerating liver significantly increased from the sixthe day and the third to the sixth day respectively, but mitochondrial aldehyde dehydrogenase showed no change.

Cunninghamella elegans에 의한 폐 mucormycosis

박경실,서광수,조무자,김춘식,심상인,김선무 대한임상병리사협회 2001 대한임상병리사회지 Vol.21 No.1

토끼에서 enrofloxacin과 enrofloxacin acetate의 比較藥物動態學

윤효인,박승춘,김창식,김민규,최기섭,신광순,박종일,조준형,조명행 충남대학교 수의과대학 동물의과학연구소 1996 動物醫科學硏究誌 Vol.4 No.-

This study was designed to examine the in vitro antibacterial activities and pharmacokinetics of enrofloxacin acetate (ENFXA) and enrofloxacin (ENFX). Two enrofloxacins had wide spectrum antibacterial activities against Gram positive and negative bacteria, and mycoplasma, showing potent antibacterial activities with low MICs (0.05-3.33 ㎍/㎖ for Gram positives, 0.002 ㎍/㎖ for Gram negatives and 0.02 ㎍/㎖ for mycoplasma). In order to investigate the profiles of two formulations of enrofloxacin we studied comparative pharmacokinetics of them in rabbits. Five rabbits were given 5 ㎎/㎏ body weight of each enrofloxacin formulation intravenously (i.v.) and orally (p.o.) in a cross-over study. Pharmacokinetic parameters of both formulations were calculated by the use of PCNONLIN, a computer program. Their bioavailibility in rabbits, the means of the area under the curve (AUC). After oral administration of each formulation in rabbits, the mean elimination half-lives (t_1/2,ke) were 3.25h (ENFX) and 4.32 h (ENFXA), and mean AUC 4.27 ㎍·h/㎖ (ENFX) and 6.21 ㎍·h/㎖ (ENFXA). Both enrofloxacin formulations seemed to have good tissue distribution and penetration as indicated by large volume of distribution: 4.76 1/㎏ for ENFX and 7.23 1/㎏ for ENFXA. With the results obtained in this study, ENFXA could be used in place of ENFX in rabbits.

세포질내 정자주입법(ICSI)에 있어서 정자흡입 및 난자내 주입방법에 관한 연구

이택후,김항진,송건호,김대근,전상식,박윤규,서태광,전병균,류은경,이은숙,문진수,김광철 경북대학교 의학연구소 2000 경북대학교병원의학연구소논문집 Vol.4 No.1

Study on Method of Sperm Aspiration and Injection into an Oocyte in Intracytoplasmic Sperm Injection(ICSI) Immobilization of spermatozoa prior to intracytoplasmic sperm iniection(ICSI) sometimes results in crooked tail and this makes it difficult to aspirate sperm into an injection pipette tail first. Head-first sperm aspiration into an injection pipette avoid this problem due to the bigger size of the sperm head. The effect of head or tail-first sperm injection into an oocyte on fertilization cleavage, percentage of grade I embryos and development to blastocyst stage in ICSI program has been studied. A single living immobilized spermatozoa from oligoasthenozoospermic patient was injected into an oocyte head-first or tail-first according to the treatment. Eighteen hours after microinjection, oocytes ware inspected for survival and fertilization Fertilized oocytes with two pronuclei were cultured in 30μl drop of mHTF supplemented with 10% heat-inactivated follicular fluid(FF) at 37℃. On day 2. embryo transfer was performed with cleaved embryos. The remaining 2-8 cell stage embryos were co-cultured with BRL cells in mHTF + 10% FF for 72 hours and the developmental stage was observed. The data were analyzed by Analysis of Variance. A total of 164 oocytes from 36 cycles were assigned to earth treatment and ICSI was performed(88 head-first, tail-first). The rates of normal fertilization were 81.8% and 76.3% for head-first and tail-first, respectively. Of the fertilized oocytes, the percentage of cleaved embryos and the percentage of grade 1 embryo among cleaved embryos were 88.9% and 68.8%, 93.1% and 74.1% for head-first and tail-first, respectively. Of the 2-8 cell embryos cultured, 44.4%(16/36) and 50.0%(10/20) for head first and tail first, respectively developed to blastocyst stage. There were no differences in fertilization, cleavage, rates of grade 1 embryos, and development to blastocyst stage. In conclusion, head-first or tail-first sperm injection into an oocyte in ICSI program does not affect fertilization and subsequent embryo development to blastocyst stage in vitro.