VS전동기를 대체하기 위한 저가형 VVVF 인버터의 개발

전희종,조성민,윤재식,손진근 崇實大學校 1999 論文集 Vol.29 No.1

VS(Variable Speed)-Motor is speed control method using eddy-current coupling. This method installs eddy-current coupling with constant speed driving Induction Motor and controls rotating speed through a charging change of a excitation current, particularly. VS-Motor is used widely because of simple control and wide speed range. But this method has large losses and low efficiency because of heating as slip drum in low speed region. In cooling, addition of a mechanical devices is difficult and in volume, large space is occupied. Using SCR for control, efficiency of system is low. In case of inverter, though advantage of high efficiency and high performance the price is expensive. Therefore, in this study, we developed low-cost type VVVF(Variable Voltage Variable Frequency) Inverter system for substituting VS-Motor.

Retinol 국소도포에 의한 눈가주름 제거효과

전희대,이성열,이혜진,박영립,이종석,황규왕 순천향의학연구소 1998 Journal of Soonchunhyang Medical Science Vol.4 No.2

In 3 months randomized, double-blind, vehicle-controlled study of retinol (vitamin A 0.1%-3000IU/g) in the treatment of photoaging skin, especially eye wrinkles. 24 patients applied retinol contained cream to the both eye wrinkles and vehicle cream(placebo) to the same site. Half of the patients received retinol contained cream and half received vehicle cream(placebo). All 24 patients who completed the study showed statistically significant improvement in photoaging eye wrinkles on the retinol contained cream treated group, but not on the vehicle treated group. Eight of the 12 patients who received retinol contained cream to eye wrinkles had improvement in photoaging, whereas only three of the 12 patients who received vehicle cream(placebo) improved. In retinol contained cream group, there is a some relationship between water contents and effects. In other words, as water contents were the higher, effects were the better. The side effects were limited to mild irritation of retinol contained cream treated skin. Retinol contained cream appeared to be safe and effective in the treatment of eye wrinkles.

계측 장비를 위한 무선 RF모듈의 개발

전희종,서영조,오정언,김병진 崇實大學校 1999 論文集 Vol.29 No.1

The existing equipment with wire communication can expect the stability of data transmission. However, according to increasing a number of Measuring Instruments, wiring work becomes a heavy burden. Restriction to application about portable Measuring Instruments and the lack of flexibility are another drawback of wire communication. This paper presents the scheme of the design and implementation of a RF(Radio Frequency) based module. The RF based module is designed to the multi communication between Measuring Instruments. The RF based module consists of RF circuit and microprocessor. The main properties of RF circuit are maximum 5[Kbps] transmission rate, maximum 90m transmission distance and 433[MHz] frequency band. The microprocessor rearrange the data into AHDLC(Advanced High level Data Link Control) format and then instructs RF circuits to transmit/receive the data. The RF module is expacted to have a wide application field such as fire/security alarm, remote control/measurement etc..

이산화티타늄계 광촉매를 이용한 벤젠의 처리 특성

전의찬,송민종,김전희 동신대학교 환경연구소 1999 환경연구 Vol.4 No.1

An available methods for abating VOC(including Benzene) are thermal or catalytic incineration, liquid absorption, solid adsorption, condensing, membranes, biodegradation and plasma discharge, but a number of defects are these VOC abating methods, including ; requires a auxiliary fuel, generate secondary pollutants(waste catalysts, waste absorbents, waste adsorbents, ozone, etc.), a large scale, etc.. But photoactive catalysts, when illuminated with UV-light, generate highly reactive radicals that can oxidize the organic contaminants in gas. One methods to increase the efficiency of the process, and thereby reduce the light energy requirement, is by developing more active catalysts. Because of, ball type TiO₂ catalyst were obtained commercially and/or prepared in laboratory were examined for their photoacivity, and they are TiO₂ added some annex(Al₂O₃, SiO₂, KsO, P₂O_(5), etc.). The organic compounds used to identify the best photo catalysis condition were benzene. This study also examined the impact of catalyst structure, light intensity, existence of oxygen as an electron acceptor and Benzene initial concentration on the reaction kinetics. Labratory experiments were performed to investigate TiO₂ photo catalysis for treating test gas contaminated with Benzene. and TiO₂ photo catalysis efficiency for mineralization of Benzene is also evaluated. The photo oxidation of Benzene was carried out in a photo catalytic reactor at room temperature. I performed BTX photo catalytic oxidation experiments using a single-pass annular reactor. The organic-contaminated gas was prepared in Teflon sampling bag(25L) and passing through photo catalytic reactor by vacuum pump which is located reactor outlet. The BTX diluted with mixture air or nitrogen gas. Flow rates for test gas stream were controlled by micro flow meter going out the reactor. The reactor illuminated with 15W near-UV lamp, BLB lamp or Fluorescent lamp. The light intensity at the catalyst surface were estimated to be 0.8 to 6mW cm-2s-1. The inner cell of the reactor was packed with ball type titanium dioxide(Ø 6mm). Benzene was determined by GC-FID of gas samples taken from the a glass sampling bulb which was located at reactor outlet by gas-tight syringe. TiO₂ photo catalysis for treating test gas contaminated with Benzene. and TiO₂ photo catalysis efficiency for mineralization of Benzene is also evaluated. Using the anatase type photo catalyst, Benzene conversion rate is greater than that of rutile(92% conversion of 100ppmv Benzene using anatase type photo catalyst, 80% conversion of 100ppmv Benzene using rutile type photo catalyst at 0.5L/min) Effect of light intensity on the rate of Benzene photo catalytic decomposition was investigated by three type lamps within the reactor. When light intensity to increase, the Benzene conversion rate to increase. Using the BLB lamp showed higher activity than the Fluorescent lamp, but UV lamp showed the hight photo catalytic activity(26% conversion of 100ppmv Benzene with Fluorescent lamp, 63.5% conversion of 100ppmv Benzene with BLB lamp, 92% conversion of 100ppmv Benzene with UV lamp at 0.5L/min). Experiments with added oxygen as an electron acceptor improved the reaction rate considerably(92% conversion of 100ppmv Benzene without oxygen, 66.1% conversion of same Benzene concentration with mixture air at 0.5L/min). The Benzene conversion rate begins to decrease while Benzene initial concentration begins to increase. We have thus concentrated our effects on the study of Benzene degradation kinetics in vary initial Benzene concentration.

흉선종 제거후에 발생한 재생 불량성 빈혈 : 증례보고

전원선,이상철,김현정,배상병,김찬규,이남수,박노진,이규택,박성규,홍대식,박희숙,원종호 순천향의학연구소 2007 Journal of Soonchunhyang Medical Science Vol.13 No.2

Thymoma is associated with myasthenia gravis, Pure red cell aplasia, and autoimmune diseases such as autoimmune hemolytic anemia, aplastic anemia, and hypogammaglobulinemia. It's association with aplastic anemia is rare and aplastic anemia appearing after surgical removal of thymoma is especially rare. The authors hereby report a case of aplastic anemia occuring in a patient who was diagnosed with thymoma and myasthenia gravis and had the tumor surgically removed. The patient was treated with anti-thymocyte globulin, cyclosporin, and prednisolone, and showed partial remission with hematologic improvements after 12 months.

이산화티타늄계 광촉매를 이용한 톨루엔의 처리 특성

전의찬,송민종,김전희 동신대학교 환경연구소 2000 환경연구 Vol.5 No.1

각종 급ㆍ만성의 건강장해를 일으킬 뿐만 아니라, 광화학 반응에 의해 오존을 형성하는 것으로 알려진 휘발성유기화합물 중 대표적인 물질인 톨루엔을 광촉매산화법으로 처리할 경우 최적 처리조건을 분석하고자 광촉매의 결정구조, 광원의 세기, 전자수용체로서 산소의 유무 등에 따른 톨루엔의 처리효율을 분석하였다. 실험결과 루틸령 결정구조에 비해 아나타제형 결정구조를 갖는 이산화티타늄의 톨루엔 처리효율이 높게 나타났으며, 광원의 세기가 높을수록 전자수용체로서 산소가 존재할 경우 높은 처리효율을 나타내었다. 시간과 공간적인 제약으로 물, 오존 그리고 증기와 같은 다양한 전자수용체가 존재할 경우의 톨루엔의 처리효율을 파악하지 못하였으며, 온도, 습도 및 촉매활성에 영향을 주는 여러 가지 인자들을 대상으로 그것들의 변화에 따른 처리효율의 고찰을 못하였다. 앞으로 보다 효율적인 이산화티타늄계 광촉매의 제조방법 개발과 이산화티타늄계 광촉매를 이용한 다양한 VOC 처리방법의 개발이 요구된다. An available methods for abating VOC(including Toluene) are thermal or catalytic incineration, liquid absorption, solid adsorption, condensing, membranes, biodegradation and plasma discharge, but a number of defects are these VOC abating methods, including ; requires a auxiliary fuel, generate secondary pollutants(waste catalysts, waste absorbents, waste adsorbents, ozone, etc.), a large scale, etc.. But photoactive catalysts, when illuminated with UV-light, generate highly reactive radicals that can oxidize the organic contaminants in gas. One methods to increase the efficiency of the process, and thereby reduce the light energy requirement, is by developing more active catalysts. Because of, ball type TiO2 catalyst were obtained commercially and/or prepared in laboratory were examined for their photoacivity, and they are TiO2 added some annex(Al203, SiO2, KsO, P205, etc.). The organic compounds used to identify the best photocatalysis condition were toluene. This study also examined the impact of catalyst structure, light intensity, existence of oxygen as an electron acceptor and Toluene initial concentration on the reaction kinetics. Labratory experiments were performed to investigate TiO2 photocataysis for treating test gas contaminated with Toluene. and TiO2 photocatalysis efficiency for mineralization of Toluene is also evaluated. The photooxidation of Toluene was carried out in a photocatalytic reactor at room temperature. I performed Toluene photocatalytic oxidation experiments using a single-pass annular reactor. The organic-contaminated gas was prepared in teflon sampling bag(25L) and passing through photocatalytic reactor by vacuum pump which is located reactor outlet. The Toluene diluted with mixture air or nitrogen gas. Flow rates for test gas stream were controlled by micro flow meter going out the reactor. The reactor illuminated with 15W near-UV lamp, BLB lamp or Fluorescent lamp. The light intensity at the catalyst surface were estimated to be 0.8 to 6㎽ ㎝-2s-1. The inner cell of the reactor was packed with ball type titanium dioxide(φ 6㎜). Toluene was determined by GC-FID of gas samples taken from the a glass sampling bulb which was located at reactor outlet by gas-tight syringe. TiO2 photocataysis for treating test gas contaminated with Toluene. and TiO2 photocatalysis efficiency for mineralization of Toluene is also evaluated. Using the anatase type photocatalyst, Touene conversion rate is greater than that of rutile(86.1% conversion of 100ppmv Toluene using anatase type photocatalyst, 78% conversion of 100ppmv Touene using rutile type photocatalyst at 0.5L/min) Effect of light intensity on the rate of Toluene photocatalytic decomposition was investigated by three type lamps within the reactor. When light intensity to increase, the Toluene conversion rate to increase. Using the BLB lamp showed higher activity than the Fluorescent lamp, but UV lamp showed the hight photocatalytic activity(19.1% conversion of 100ppmv Toluene with Fluorescent lamp, 60.4% conversion of 100ppmv Toluene with BLB lamp, 86.1% conversion of 100ppmv Toluene with UV lamp at 0.5L/min). Experiments with added oxygen as an electron acceptor improved the reaction rate considerably(86.1% conversion of 100ppmv Toluene without oxygen, 62.5% conversion of same Toluene concentration with mixture air at 0.5L/min).

환경기초시설 중 하·폐수처리과정으로부터의 GHG 배출량 예측 : 광주·전남지역을 중심으로 Kwang ju·Chollanado

전의찬,김전희,송민종 동신대학교 환경연구소 2000 환경연구 Vol.5 No.1

본 연구는 환경기초시설 중에서 생활하수와 산업폐수 처리장에서 발생하는 특히 광주·전남 지역을 중심으로 온실가스의 배출량과 장래 저감 잠재성을 평가하고, 기후변화협약을 대비한 국가 Inventory의 기초자료로 이용될 수 있도록 하였으며, 결론적으로 하ㆍ폐수부문에서 온실가스 배출 잠재성을 감소시키기 위한 방안으로 먼저 하수 및 폐수의 체계적인 수집이 이루어져야 하며, 수집된 하ㆍ폐수는 반드시 적절한 처리과정을 통하여 수계에 배출되어져야 한다. 또한 적절한 처리과정 중에 배출되는 온실기체의 대기 중으로의 누설을 억제하고 회수율을 높이는 관리대책이 수립되어야 하며, 회수율을 높이는 대책은 하ㆍ폐수부문에서 온실가스 배출 잠재력에 대한 저감율에 대하여 좀더 효율적임을 알 수 있다. 또한 상기와 같은 저감방법 외에도 하ㆍ폐수부문에서의 온실가스 저감잠재력을 위하여 정부는 온실가스 배출량을 계산하는데 필요한 여러 가지 자료를 확보하고, 좀더 신뢰할 수 있는 온실가스 배출량을 산출하며, 이들 자료를 토대로 정부는 하ㆍ폐수부문에서의 온실가스 저감잠재력을 위하여 연차적으로 관리대책을 설정해야 한다. 그리고 이에 대한 검중체계를 마련하여 전ㆍ후 효과분석을 해야 할 것이다. This study evaluated greenhouse gas(GHG) emissions and future reduction potential emitted from domestic and industrial wastewater treatment system in Kwangju city and Chollanamdo. For decreasing of GHG emissions potential, systematic collection method of domestic and industrial wastewate is established and collected domestic and industrial wastewater is treated reasonal wastewater treatment process. GHG which is leak from wastewater treatment process to air was controled, Control policy which are increasing recovery ratio was established. In addition to decreasing method, Government make sure of variable data fro estimating GHG emissions quality and evaluated GHG emissions quality reliable method.

대구지역 치과의사들의 누적외상성 장애에 대한 조사

전만중,사공준,이중정,이희경,정종학 大韓産業醫學會 2001 대한직업환경의학회지 Vol.13 No.1

목 적 : 치과의사를 대상으로 누적외상성 장애의 증상유병률 및 양상을 조사하고 그 관련요인을 규명하여, 다양한 직종별 데이터 베이스 구축에 기초자료 제공 및 직종별 비교를 통한 누적왁상성 장애의 예방대책수립에 도움이 되고자 시행하였다.방 법 대구광역시에서 진료행위를 하고 있는 치과의사 512명을 대상으로 인구학적 요인과, 진료관련특성, 사회심리적요인, 자각증상에 대해 설문 조Al하였다. 사회심리적 특성으로는 직무요구도(5항목), 정신신체적 긴장도(5항목), 직무불만족도를 측정하였으며(Karasek, 1994), A형 행동양상도 함께 측정 하였다.자각증상에 대한 조사는 송동빈 등(1997)에 의해 개발된 자각증상 설문지를 이용하였으며 목, 어깨, 팔 및 팔꿈치, 손목, 손가락, 등에 통증이나 쑤심, 저림등의 불편한 증상과 관련된 변수들을 조사하였다.조사된 결과는 N10SH의 근골격계장애에 대한 감시를 위 한 기준을 적용하여 분석하였다.결 과 : N10SH 감시기준에 의한 누적외상성 장애 증상호소율이 63.3 %로 높게 나타났으며, 그 증상호소부위는 어깨, 목, 허리, 손과 손목, 무릎, 발과 발목의 순이였다. 진료위치는 9시에서 10시 방향에서의 접근이 가장 많았으며 이들 중 어깨 부위의 증상호소율이 가장 높았다.근무경력은 5년에서 10년 사이가 가장 많았으며 이들도 목과 어깨부위의 증상호소율이 가장 높았다.대상자들이 주로 보는 환자에 따른 증상 호소율은 치주치료를 주로 하는 경우 증상호소율이 가장 높았으며, 연령별로는 30~◎세에서 증상호소율이 70 %로가장 높았다. 성별로는 여성에서 증상호소율이 높았으며, 미흔인 대상자에서 증상호소율이 높게 나타났다. 일일 진료환자수에 따른 증상호소율은 21명 이상을 진료하게 되는 군에서 70 %로 가장 높았다.로지스틱 회귀분석을 한 결과 정신신체적긴장도와직무요구도가 높을수록 누적외상성 장애의 증상호소가 높은 것으로 나타났다. 또한 A형 행동양상을 보일수록증상호소가 높았으며, 쳐근 3개월 동안에 진료위치를 변경한 경우도 증상호소가 높은 것으로 조사되었다.결 론 : 조사한 일반적, 직업적 특성, 진료판련특성 및 사회심리학적 특성을 독립변수로 하여 다변량로지스틱 회귀분석 결과 여성에서 누적 외상장애증상발현위험이 남성에 비해 높은 것으로 조사되었으며,정신신체적 긴장이 높을수록, A형 행동양상 일수록누적외상성 장애증상 발현위험이 높았다. 위의 결과로 볼 때 치과의사의 경우 숙련되고 섬세한 근골격계운동을 지속적으로 반복해야 한다는 특성파 불안정한자세를 장시간 취해야 한다는 작업적 특성으로 인한근골격계 장애의 발생은 물론이고 환자 만족도에도신경을 써야하는 등의 정신적 스트레스도 누적외상성장애를 일으킬 수 있는 위험요인이라 할 수 있겠다. Objective : To investigate the symptom prevalence and aspects of symptoms for cumulative trauma disorders in dentists and elucidate their associated factors. Methods : A questionnaire-based investigation on demographic factors, work-related characteristics, psychosocial factors and symptoms of 512 dentists practicing in Daegu metropolitan city was conducted. Subsets of psychosocial characteristics, including job demand(5 items), psychosomatic strain(5 items), job insecurity, and type A behavior were also assessed. For the evaluation of symptoms early developed questionnaire by Song (1997) was used to investigate the parameters related to pains in the neck, shoulder, arm and elbow, wrist, finger, back or discomforts, such as pricking and numbing. Results : The symptom prevalence of cumulative trauma disorders, calculated based on NIOSH criteria, was high at 63.3%; the most frequent site of complaint was the shoulder, followed by neck, back, hand and wrist, knee, foot and ankle. The most common approach position was direction of 9 to 10 o'clock. Most subjects had 5-10 years of work experience and those with such years of experience also complained most frequently of symptoms in the neck and shoulder areas. As to rate of symptom complaint according to the type of dental procedure, the highest rate was associated to periodontic treatment. According to age, those between the age of 30-40 had the highest symptom prevalence rate at 70 %. According to sex, women had the higher symptom prevalence rate. Unmarried subjects also had higher symptom prevalence rate. The results of logistic analysis showed that the higher the psychosomatic strain and job demand, the higher the symptom prevalence rate of cumulative trauma disorders. Moreover, the higher the score of type A behavior, the higher the symptom prevalence rate, and even those who changed the location of their practice for the last three months also showed high symptom prevalence rate. Conclusions : The results of multiple logistic regression analysis, which incorporated demographic, work-related and psychosocial characteristics as independent variables, showed that women were at a higher risk than men in developing cumulative trauma disorders; and that the higher the psychosomatic strain and more frequent type A behavior, the higher the risk of developing cumulative trauma disorders. The above results seem to suggest that not only continual, repeated fine and skillful musculoskeletal movements and lengthy hours in an uncomfortable position but also the psychological stress related to patient satisfaction, can lead to cumulative trauma disorders.

C₄유분을 이용한 옥텐류의 합성에 있어서 1,3-Butadiene의 함량에 따른 이량화 촉매의 수명에 관한 연구

전종기,한원희,조정호,고승태,노상균 동양대학교 2001 동양대학교 논문집 Vol.7 No.1

Selective hydrogenation of 1,3-butadiene in C4 raffinate was carried out in fixed bed reactor using Pd/a1unina catalysts, Concentration of 1,3-butadiene in C4 raffinate could be reduced under 100 ppm.The life of dimerization catalyst using C4 raffinate after selective hydrogenation was longer than that of dimerization catalyst without selective hydrogenation.It was found that dilution of olefin concentration in feed was effective to increase dimerization catalyst life.

액정유체의 압력 유도 흐름에서의 분자 배향과 속도 분포

한원희,조정호,전종기,노상균,고승태 동양대학교 2001 동양대학교 논문집 Vol.7 No.1

본 연구에서는 액정의 압력 유도 흐름에 대해 적응성 토크 균형식과 코시 운동량보존식을 액정 연속체 이론의 핵심이 되는 Leslie-Ericksen 이론에 적용하여 수치해석 방법들로 풀어내었다.비선형 편미분 방정식계의 해를 구할 때 경계조건으로 쓰인 분자 배향닻 조건은 평행 닻조건(parallel anchoring)과 직교 닻조건(homeotropic anchoring)이다.분자 배향 분포는 평행 닻조건에서나 직교 닻조건에서나 시간이 지남에 따라 간단한 전단 흐름에서와 같이 3차원 비평판 배향의 구조를 갖게되지만 배향 비틀림의 구조가 다름을 알 수 있었다.배향 비틀링의 3차원적 구조를 갖게됨에 따라 압력 구배가 걸리는 흐름방향의 주 속도 분포뿐만 아니라 직교되는 방향으로 부 속도분포가 생기며 정상상태로 발전해가는 속도 분포 진화는 점근적이 아닌 진동적이다.비정상상태에서나 정상상태에서 속도 분포는 비 뉴톤성임을 알 수 있다.비등방성 Miesowicz 점도 순열에 따른 평행 닻조건에서의 더 많은 흐름량을 볼수 있고 직교 닻조건에서는 벽면에서 보이는 작은 속도 구배량의 특징을 가진다.