韓國人의 各 臟器組織中 靑酸鹽의 微量分布에 關한 硏究(Ⅱ)

張成吉,金恩浩,金英雲,李鎭勳,柳在薰,權五星,金明德,吳世珍,金由那 內務部 國立科學搜査硏究所 2001 國立 科學 搜査 硏究所 年報 Vol.33 No.-

폴리머碍子의 自然劣化現狀에 關한 硏究

張善奉,張錫九,沈在明 大田産業大學校 2000 한밭대학교 논문집 Vol.17 No.1

In this paper, for the estimation of its long-term reliability, we took polymer insulators used at the seashore during about 2 or 4 years. it used a variety of methods to understand deterioration characteristics for these polymer insulators. For investigating the degree to change inherent characteristics, we performed electrical flashover voltage test, leakage current measurement. and for examining surface properties of its materials, we utilized SEM. FTIR-ATR and contact angle meter. These test results had been compared virgin ones with aged samples in the field. In the electrical flashover test with all samples, although it had a slight reduction. the flashover voltages was in the boundary of KS criteria. The results showed that the contact angles of aged sample surfaces were larger than that of virgin ones. however, sample B which had a short experience in the field showed contact angle to be reduced. Because of the environmental impact on polymer insulators, exposed for many years under natural conditions. it was verified the insulator material at the surface of the insulators undergoes a slight degradation process as the micro cracks at the inspection utilizing SEM. In conclusion, the polymer insulators aged during 2 or 4 years under our national environment showed agreeable performance. For exactly evaluating its long-term performance, we need to cumulate data that was the results to analyzing characteristics on polymer insulators.

가솔린 화재의 소화를 위한 수분무의 특성에 관한 실험적 연구

장용재,김명배,김유 (社)韓國火災 ·消防學會 1995 한국화재소방학회논문지 Vol.9 No.2

This study discribes characteristics of water spray for extinguishment of gasoline fire. Experiments are carried out for the gasoline pool fire with the atomizing nozzles. Droplet size, spray pressure, amount of water which reaches the flame base and velocity of water spray are measured to find extinguishment conditions. Air entramment due to the water spray and extinguishing process of gasoline fire by water spray are visualized. Boundary conditions of water spray for extinguishment of gasoline pool fire is quantitatively shown. As the result of experiments, it is found that the velocity of entrainment air and sprayed water are almost same and the water droplets size having small diameter under 40㎛ can not extinguish the fire because too small droplets does not reach the fuel surface.

인간 면역부전 바이러스(HIV) 감염자 사이에서의 1기 및 2기 매독의 유행

장희창,조재현,박완범,이기덕,이창섭,김홍빈,오명돈,최강원 대한감염학회 2004 감염과 화학요법 Vol.36 No.6

목적 : 국내 HIV 감염자 사이에서 발생한 매독의 유행을 보고하고, 그 역학적 특성을 규명하고자 하였다. 재료 및 방법 : 1999년 7월부터 2003년 9월까지 서울대학교 병원에서 추적 관찰을 받아온 HIV 감염자를 대상으로 하여 1기 및 2기 매독의 발생을 조사하였다. 발생률을 정확히 구하기 위해 추적 관찰을 받은 모든 HIV 감염자의 인년을 6개월 간격으로 구하였다. 결과 : 51개월 동안, 465명의 HIV 감염자가 서울대학교 병원에서 추적 관찰을 받았다. 이중 38명이 1기 및 2기 매독으로 진단되었다. 1기 및 2기 매독의 발생률은 이기간 동안 100인년 당 4.1명이었다. 1999년 7월부터 2001년 12월 사이에는 발생자가 없었으나, 이후 발생률은 꾸준히 증가하여 2003년 9월에는 100인년 당 18.8명이 되었다. 1기 및 2기 매독의 발생률은 동성애자 및 양성애자에서 이성애자에서보다 4.3배 높았고, HAART로 치료를 받지 않은 환자에서 HAART로 치료를 받고 있던 환자에서 보다 10.9배 높았다. 결론 : 2002년부터 국내 HIV 감염자 사이에서 1기 및 2기 매독이 유행하기 시작하였고, 이러한 유행은 동성애자와 양성애자 및 HAART로 치료를 받고 있지 않던 사람 사이에서 발생하였다. Background : This study was performed to characterize the epidemiologic and clinical features of outbreak of syphilis among HIV sero-positive patients in Korea. Materials and Methods : A retrospective case review of patients diagnosed with primary and secondary syphilis from July 1999 to September 2003 was carried out at Seoul National University Hospital in Korea. To estimate the incidence, person-years (PYs) of all HIV sero-positive patients, who visited the hospital in the same period, were calculated every 6 months. Results : In a 51 month period, 465 HIV-positive patients were followed up at Seoul National University Hospital. 38 cases of primary and secondary syphilis were diagnosed. The incidence of primary and secondary syphilis was 4.1 per 100 PYs during the study period. There was no case from July 1999 to December 2001, and then the incidence rose until September 2003 from 5.5 per 100 PYs in 1999 to 18.8 per 100 PYs in 2003. The rate of primary and secondary syphilis was 4.3 times higher among homosexual and bisexual men than heterosexual men (95% CI 1.87 to 11.17), and 10.9 times higher among patients who did not receive HAART than patients who were receiving HAART (95% CI 5.47 to 21.79). Conclusion : The outbreak of primary and secondary syphilis among HIV-positive patients started in 2002 and has been escalating, especially among homosexual/bisexual men and in patients who did not receive HAART.

개의 심낭내 투여한 Quinidine이 삼장 유효불응기에 미치는 영향

한명철,김재형,노태호,김희열,김종진,조은주,진승원,유기동,이만영,채장성,홍순조,최규보 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.4

전류형 인버터의 계통연계형 리액터용량 경감에 관한 연구

김재철,심재명,장석구 大田産業大學校 2001 한밭대학교 논문집 Vol.18 No.-

Most of present electricity is supplied by nuclear, hydro and fossil power plants. These kind of plants also raise questions about resource, pollution and environment. Alternative energy can gelp answer these questions in the form of naturally occurring ources of energy, such as the sun, the wind, geothermal, heat, biomass and so on. As alternative energy generates the direct electical currents, which should be converted into the alternating currents to be connected to the system, the use of inverter as a power converting circuit is definitely required. There are two types of inverters. The voltage-source inverter is the one and the current source inverter is the other. While the current-source inverter has such a disadvantage as large direct reactor required for constant direct current, it is practically more useful than the voltage-source type to be safe without showing the surge current and dead time in case of both load and inverter short. The interactive generation system for the alternative energy is composed of a PWM chopper and a current-source inverter. There are two methods to reduce the direct reactor increased by the introduction of this current-source inverter. The first method is to insert parallel resonance circuit into the direct current and the second one is to make two times of frequence, to restrain the ripple of the direct reactor current. In this paper, there two methods were compared and evaluated through simulation and experiment. Eventually, it was found that the second method was much better than the first one in terms of restraining of the ripple of the direct reactor current as well as reduction of the reactor by half.

Probe 위치 변화에 따른 이음향방사의 변화

장봉익,이재욱,김상렬,강명구,김리석 대한이비인후과학회 1999 대한이비인후과학회지 두경부외과학 Vol.42 No.7

Cs-137 γ-선 조사장치의 방사선장 해석연구

전재식,채하석,이철영,오장진,이병영,명동범 충남대학교 기초과학연구소 1995 忠南科學硏究誌 Vol.22 No.1

In reference to the ISO-4037 and ANSI N13.11, appropriateness of the shielding and collimating system, and suitability of the irradiation and its environmental conditions of a 20 Ci Cs-137 gamma-ray irradiator installed in Korea Institute of Nuclear Safety(KINS) were investigated. Upon the installation of the irradiator, condition of collimator alignment and virtual beam cross section were examined by use of a portable He-Ne laser. In order to evaluate the fitness of the secondary(scattered) to primary ratio of the collimated gamma-ray beam from the irradiator in light of ISO and ANSI requirement, the measurements of the secondary to primary ratio were performed by use of a cavity type ion chamber which had been calibrated in a calibration laboratory that maintains reliable traceability. For the theoretical assessment of the gamma-ray field the collimated beam were divided into fifteen sectors and for each sector the secondary to primary ratio and the gamma-ray spectrum was simulated by means of Monte Carlo method. The outcomes were compared with the experimental results, and cause of scattering and the existence of alleged modifying factors in the irradiator were examined.

법과학적 응용을 위한 토양의 동일성에 관한 연구 : 토양에서 미량원소 및 희토류 성분의 분석법에 관한 연구 Analytical Method of Trace Element and Rare Earth in the Soil

김재균,김은호,김명덕,장성길,박성우 內務部 國立科學搜査硏究所 2002 國立 科學 搜査 硏究所 年報 Vol.34 No.-

파손된 치면열구전색제의 수리 방법에 따른 미세누출 비교

강명봉,현홍근,김영재,김정욱,장기택,이상훈,한세현,김종철 대한소아치과학회 2007 大韓小兒齒科學會誌 Vol.34 No.2

치면열구전색은 수 십년간 교합면 우식의 예방에 가장 효과적인 방법 중 한가지로 알려져 왔다. 하지만 치면열구전색제의 마모와 파절 때문에 치면열구전색제의 재시술 또는 수리를 필요로 하게 되었다. 본 연구의 목적은 파손된 치면열구전색제를 수리할 때 치질과 잔여 전색제의 표면처리 방법에 따른 미세누출 차이를 알아보고자 하는 것이다. 120개의 영구 대구치에 치면열구전색제를 적용하고 인위적인 파손을 만든 뒤 인공타액에 4주 동안 보관하였다. 4주 후 근심 또는 원심의 치면열구전색제가 완전히 파손 양상을 나타내는 치아 60개를 선택하여 각각 15개씩 4개 군으로 나누어 실험에 사용하였다. 각 군을 산부식만 시행한 경우(1군), air-abrasion만 시행한 경우(2군), 산부식 후 결합제를 적용한 경우(3군), air-abrasion 후 결합제를 적용한 경우(4군)로 나눠 각각의 치아를 표면처리한 후 치면열구전색제를 도포하였다. 고온(55℃)과 저온(5℃)에서 각각 30초씩 500회의 열순환을 시행한 뒤 미세누출도를 검사하여 다음과 같은 결과를 얻었다. 1. 치면열구전색제/치면열구전색제 경계면에서 미세누출도는 결합제 사용 유무에 관계없이 air-abrasion을 처리한 2군, 4군에서 산부식을 사용한 1군, 3군보다 낮은 값을 보였고(p<0.05) 1군과 2군, 3군과 4군 사이에는 통계적 유의차가 없었다(p>0.05). 2. 치면열구전색제/치아 경계면에서 미세누출도는 결합제를 사용한 3군, 4군에서 결합제를 사용하지 않은 1군, 2군보다 낮은 값을 보였고(p<0.05) 산부식을 사용한 1, 3군과 air-abrasion을 사용한 2, 4군 사이에는 통계적 유의차가 없었다(p>0.05). 3. SEM 상에서 치면열구전색제를 산부식 처리하였을 때 표면거칠기의 증가가 적었으나 air-abrasion 하였을 경우 표면거칠기가 현저하게 증가하는 것을 관찰하였다. The aim of this study was to investigate whether differences in surface treatment Prior to repair influenced the seal of a resin fissure sealant placed on the occlusal surfaces of permanent molar teeth. One hundred and twenty extracted human molars were selected and a light curing sealant was placed on their occlusal surface following cleaning by prophylaxis and acid etching. The teeth were deliberately damaged, and then stored in artificial saliva for four weeks. Sixty teeth with the desired morphology of sealant failure were randomly divided into four groups where one group was treated with only etching agent, another by only air-abrasion, another by applying an etching agent followed by a bonding agent, and the last by air-abrasion followed by a bonding agent each. After sealant application, the samples were thermocycled and the degree of microleakage was determined. The results were as follows: 1. In the sealant/sealant interface, group 2(0.22), 4(0.23) using air-abrasion showed a significantly lower microleakage score than group 1(0.38), 3(0.35) using an etching agent(p<0.05). There were no statistically significant differences(p>0.05) between groups 1, 2 and groups 3, 4. 2. In the sealant/tooth interface, group 3(0.20), 4(0.20) which used a bonding agent showed a significantly lower microleakage score than group 1(0.35), 2(0.40)(p<0.05). There were no statistically significant differences (p>0.05) between groups 1, 3 and groups 2, 4. 3. In SEM examination, while sealant surfaces treated with etching did not result in highly rough surfaces, those treated with air-abrasion did show rough surfaces.