혼합용매법에 의한 Mullite 전미분체 생성기구에 관한 연구

황운연,이정운,박형상,김용렬,구기갑 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.4

Si-와 Al-알콕시드의 반응속도 차이를 조절하기 위한 부분 가수분해법과 입자 형태를 제조하기 위한 혼합용매법을 이용하여 구형의 미세한 mullite 전미분체를 제조하였다. Mie 이론을 적용시켜 반응시간에 따른 반응용액의 탁도 및 입자 수밀도의 변화를 측정하여 혼합용매법에 의한 입자 생성기구에 대하여 고찰하였다. 알콕시드와 옥탄올 용액에 아세토니트릴을 첨가하면 알콕시드의 용해도가 낮아지고 따라서 알콕시드의 일부가 액적을 형성하며, 액적은 안정화제 (HPC)에 의하여 구형을 유지하게 된다. 그리고 가수분해 및 축합중합 반응에 의하여 액적의 입자 크기는 감소하며, 동시에 혼합용액에 용해되어 있던 알콕시의 가수 분해 및 축합중합 반응에 의하여 미세 입자가 생성된다. 액적형태로 생성된 큰 입자와 미세 입자의 응집에 의하여 최종 입자가 생성되었다. In this study, spherical fine pre-mullite particles were prepared by partial hydrolysis method to control the reaction rate difference of two alkoxides, and by mixed solvent method to control the particle shape. Based on the adaptation of Mie theory, the formation mechanism of pre-mullite particle in alkoxide-octanol-acetonitile system has been investigated by measuring of the turbidity of solution, the number density and the size of the particles during the reaction. As the acetonitrile was added in the alkoxide-octanol solution, the solubility of the alkoxide decreased. A part of alkoxide was segregated from solution in the form of droplets. whereas the rest of the alkoxide existed as dissolved state in octanol. The droplets are stabilized with stabilizer (HPC). In the next step. hydrolysis and condensation reactions of the alkoxide droplets decrease the size of droplets and, at the same time, fine particles are formed from the alkoxide dissolved in octanol. Subsequently, the final particles are produced by aggregation between the large particles through the droplet form and the fine particles.

정신분열병과 Glutathione S-Transferase M1유전자 다형성

배치운,조자현,김연주,김태석,김정진,이창욱,이수정,전태연,이철,백인호 大韓神經精神醫學會 2004 신경정신의학 Vol.43 No.5

Objectives : This study aimed to test the possible association between Glutathione S-Transferase Ml gene (GSTMl) variants and schizophrenia. Methods : One hundred and eleven inpatients with schizophrenia and 130 healthy controls were recruited. Genotyping was performed by polymerase chain reaction-based method. Results : The GSTMl null genotype was significantly more frequent in patients with schizophrenia than in controls (p=0.014, odd ratio=1.93, 95% confidence interva1=1.115-3.351), while GSTMl genotype vahants were not associated with either tardive dyskinesia (TD) or total Abnormal Involuntary Movement Scale (AIMS) scores. Conclusion : The present study suggests that the GSTMl polymorphism may confer susceptibility to the development of schizophrenia but not to TD, at least in Korean population.

Sprague Dawley 수컷 랏트에서 Bisphenol A Diglycidyl Ether의 경구 투여에 의한 급성 독성

임재언,양윤정,이태진,홍연표 대한산업의학회 2006 대한직업환경의학회지 Vol.18 No.4

목적: 본 연구는 BADGE의 경구 투여에 의한 급성 독성학적 연구를 수행하여 기존의 연구 결과를 확인하고 추후 내분비계 장애 연구에 필요한 기초자료를 얻고자 하였다. 방법: 수컷 SD 랏트에 0, 1000, 2000, 4000과 8000 mg/kg/day의 BADGE와 DES 0.37 mg/kg/day의 농도를 단회 경구로 투여한 후 14일간 일반 증상 등을 관찰하였고 14일 후 부검하였다. 결과: BADGE를 투여한 모든 군에서 투여 후 3일째에 설사와 다른 일반 증상들이 관찰되었고 체중도 감소하는 경향을 보였다. 특히 8000 mg/kg/day의BADGE를 투여한 랏트에서 투여 후 3일째에 대조군에 비해 유의한 수준으로 체중이 감소하는 것을 관찰할 수 있었다. 일부 BADGE 투여군에서 대조군에 비해 심장(1000, 2000과 4000 mg/kg/day), 간(1000, 2000, 4000과 8000 mg/kg/day)과 전립샘(4000 mg/kg/day)의 무게의 감소가 관찰되었다. BADGE 투여군의 간(1000과 4000 mg/kg/day)과 전립샘(8000 mg/kg/day) 의 상대 무게가 대조군과 차이를 보였다. 고환을 제외한 모든 장기에서 조직학적인 변화는 관찰되지 않았으며 고환에서는 세 정관에서 정자세포의 감소가 관찰되었다. 고환과 부고환의 sperm head 수를 보면, 고환에서만 감소하는 경향을 보였으며 정자의 운동성과 기형은 대조군과 차이가 없었다. 혈장 에스트로겐과 테스토스테론 농도는 대조군과 모든 투여군 간의 유의한 차이가 없었다. 결론: BADGE를 랏트에 경구 투여 하였을 때 1000 mg/kg/day의 수준에서도 일반 독성 및 생식독성을 유발시킬 수 있음을 보여준다. Objectives: Bisphenol A Di Glycidyl Ether (BADGE) is the major component in commercial liquid epoxy resins, which are manufactured by co-reacting bisphenol A with epichlorohydrin. The authors investigated the acute toxicity of BADGE. Methods: BADGE was administered by a gavage to 8 week old SPF Sprague Dawley rats in a single dose of 0 (negative control), 0.37 (Diethylstilbesterol, DES), 1000, 2000, 4000, and 8000 mg/kg/day of BADGE. Each treatment group contained 7 rats. The general status and weight of the rats were observed for 14 days. The rats were anesthetized by ether at 14 days, and the changes in morphology, organ weight, sperm count and motility, and hormone level were measured. Results: All the rats treated with BADGE had diarrhea on the 1st day. The rats administered BADGE at 1000, 2000, and 4000 mg/kg/day showed a soiled perineal region and soft stools with diarrhea until the 3rd day. The 8000 mg/kg/day BADGE rats had diarrhea for two days followed by emaciation, soiled fur, a soiled perineal region, staining around the mouth and were moribund for three to eight days. No weight gain was observed after the 1st day in the 2000, 4000, and 8000 mg/kg/day BADGE rats and after the 7th day in all the treatment groups compared with the control groups. Some treatment groups were observed to have a decrease in the weight of the heart (BADGE 1000, 2000 and 4000 mg/kg/day), liver (BADGE 1000, 2000, 4000 and 8000 mg/kg/day) and prostate (BADGE 4000 mg/kg/day) compared with control group. The weight of the liver was significantly lower in all treatment groups compared with the control group. The relative weight of the liver (BADGE 1000 and 4000 mg/kg/day) was significant lower than the control. No pathological changes were observed in the brain, liver, thyroid, heart, spleen, kidney, lung and prostate. The number of spermatid in the seminiferous tubule in the testes was lower in all treatment groups than the control. The sperm motility tended to decrease with increasing concentration but the sperm count was similar in all treatment groups. The plasma Estrogen and testosterone level were similar in the control and treatment groups. Conclusions: These results suggest that BADGE induces general, hepatic and reproductive toxicity at 1000 mg/kg/day.

미세 패턴에서 공정 여유도를 고려한 선폭 분석

정연운,조선영,오진경,오혜근 漢陽大學校 工學技術硏究所 1997 工學技術論文集 Vol.6 No.1

The linewidth variation with different process variables, such as exposure dose, thickness of PR, thickness of thin film, and the optical property of thin film, was studied for deep UV light and resist developed 0.25 μm isolated line pattern. We found that the PR thickness which gave minimum linewidth showed larger exposure latitude and smaller linewidth variation compared to the PR thickness which gave maximum linewidth. Thus it will provide better process latitude and smaller linewidth variation if we use this PR thickness.

야간 환자 발생양상에 관한 조사연구

원광연,심운택,조영채 충남대학교 의과대학 지역사회의학연구소 1988 충남의대잡지 Vol.15 No.2

This study was conducted with 800 patients, who came to the emergency rooms of hospital and clinic at night time of Cheongju medical bloc, to look for the characteristics of the occurance of: emergency patients at night time, for randomly sampled 7 days containing each different day from April 1st. to April 30th. 1987 on the basis of such various factors as age, sex, residence and status of patients. The following conclusions were obtained 1. The percentage of emergency patients by sex were 60.1% in male and 33.9% in female, making the ratio 1.54 : 1. The age group of 10s and 20s occupied 40.3% of all patients. 2. The percentage of each disease was 41.1% in injury and poisoning, 17.2% in disease of the respiratory system, 16.1% in disease of the digestive system. 3. Male had a higher incidence in the injury and poisoning, disease of the respiratory system, infectious and parasitic disease, but disease of the digestive system, disease of the nervous system and sense organ, complication of pregmancy, child birth and the p lerperium were higher in female. 4. Age distribution of emergency patients showed as followes : Injury and )oisoning had a higher percentage in the age group of 10-49 years, disease of respiratory system under 1 years of age, disease of the digestive system over 30 years of age, disease of circulartory system in 40-50 years of age. 5. Disease distribution on residential area revealed that residents out of city had higher propor tion of injury and poisoning, infectious and parasitic disease than the ones in city. The time of staying in the emergency room were less than 1 hour in 69% of all patients. 6. The status of patients when leaving the emergency room were complete cure(68.7%), admission(17.9%) self-discharge (12.5%), and death(0.9%).

Fluoxetine 투여와 관련된 양측 측두하악관절 손상 1예

배치운,김연주,김태석,김정진,이창욱,이수정,이철,백인호 大韓神經精神醫學會 2004 신경정신의학 Vol.43 No.4

We hereupon present a case of injured temporomandibular joint (TMJ) associated with fluoxetine monotherapy-inducedrepeated yawning. Further information is needed regarding the relationship between fluoxetine administration and clinically significant yawning. Clinicians should be more careful to listen to their patients when they describe unexpected reactions to medications.

32Watt 형광등용 3단자 반도체 스타터의 개발 및 특성

박종연,지광현,김은광 江原大學校 産業技術硏究所 1997 産業技術硏究 Vol.17 No.-

Various types of electronic starter have been developed for the general fluorescent lamps with magnetic-type ballasts. However, the FL032/T8 fluorescent lamp requires higher voltage to discharge the lamp. The general starter with two-terminal is not suitable for the FL032/T8 slim-line type fluorescent for its higher discharge voltage. The suitable starter with three terminals have been studied for the FL032/T8 lamp in this paper. The developed starter have better characteristics in view points of the discharge voltage magnitude. We have proposed and designed the three terminals electronic starter. The proposed starter have been experimented and compared with the other 2-terminal general starters. By the experimental results, we have concluded that the proposed starter is suitable to the FL032/Ts lamp.

C_(1)-HVOCs 제거를 위한 Ru-Sn/γ-Al_(2)O_(3) 촉매 제조 및 반응성 평가

김영주,황운연,구기갑,김용렬,박종수,윤왕래 한국화학공학회 2004 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.42 No.1

HVOCs 제거에 사용되는 백금-팔라듐계보다 저렴한 촉매 개발을 목적으로 다양한 루테늄계 촉매를 제도하여 C_(1)-HVOCs 분해 특성 평가 실험을 수행하였다. 그 결과 Ru[2]-Sn[2]/γ-Al_(2)O_(3) 촉매가 가장 우수한 성능을 보였다. 구조 증진제인 주석은 흡착 산소의 양을 증가시키고, 다양한 산소 이온 종의 생성에 기여함을 알 수 있었다. HVOCs 분해 반응에 첨가되는 산소 원자는 주로 루테늄과 주석에 흡착되며, CH_(3) 등 HVOCs는 지지체인 γ-Al_(2)O_(3)의 브뢴스테드 및 루이스 산점에 흡착됨을 알 수 있었다. 흡착된 HVOCs의 염소와 브뢴스테드 산점의 수소 화학 결합에 의한 HCl의 생성 반응이 HVOCs 분해의 주 반응 기구임을 알 수 있었다. Various ruthenium(Ru) based catalysts, which were less expensive than Pt-Pd based catalysts, were prepared and their activity with C_(1)-HVOCs(Halogenated Volatile Organic Compounds) was evaluated. Ru[2]-Sn[2]/γ-Al_(2)O_(3) was found to have the most desirable effect on the destruction of HVOCs. Tin taken as a structural promoter was found to increase the amount of oxygen adsorption and to generate various oxygen ions. Oxygen atoms were found to be mainly adsorbed on the surface of ruthenium and tin and HVOCs such as CH_(3)Cl to adsorbed on Bronsted and Lewis acid sites of γ-Al_(3)O_(3) supports. It was found that the formation of HCl by the reaction of chlorine in HVOCs with hydrogen atom on Bronsted acid site was the main reaction mechanism in the destruction of HVOCs.

시판 양말의 내구성에 관한 연구

김종은,박은희,신연주,이운희 효성여자대학교 가정대학 학도호국단 1985 家政大論集 Vol.4 No.-

This study was purposed to investigate the durability of mens socks. We purchased samples which were four kinds of cotton 100%, wool 100%, wool/nylon 65/35%, acryl/polyester/nylon 70/20/10% at several department store in Daegu city, then measured abrasion strength and bursting strength at 65, 75, 84, 95% relative humidity. The results were summarized as follows. 1. Durability of socks decreased in propotion as relative humidity increased. 2. The greatest durability of socks was acryl/polyester/nylon 70/20/10%, the least was wool 100%. 3. Abrasion strength of socks was distinguisedly decreased at high relative humidity environment which was more than 84%.

차량 충돌 방지용 24㎓ 레이더 주파수대의 근거리 전파손실특성

하덕호(Deock-Ho Ha),류지열(Jee-Youl Ryu),김성운(Sung-Un Kim),최연욱(Yeon-Wook Choi) 한국정보기술학회 2011 한국정보기술학회논문지 Vol.9 No.8

In this paper, we describe the short range propagation loss characteristic of 24㎓ frequency band used for automotive collision avoidance radar (ACAR). To investigate the radio propagation characteristic of ACAR signals, we used 24㎓ UMCW (Un-Modulated Continuous Wave) signals using by several polarized antenna combinations. To detect the accurate message data for safety guiding ACAR, we analyze and investigate the optimum receiving condition from the short range UMCW signal of the 24㎓ frequency. From the measurement analysis, it can be clearly seen that the short range UMCW signal can be encountered to multipath interference due to scattering rays from the ground plane and adjacent moving obstacles. In addition, it was also found that the received signal strength of circularly co-polarized antenna shows the most strong envelopes and best fading reduction effect.