건조기에서 Amino수지 성형재료의 경화특성에 관한 연구

최재욱,최일곤,목연수,김상렬 釜慶大學校 1998 釜慶大學校 論文集 Vol.3 No.2

We studied the effect of mass transfer in a dryer on the condensation of amino resin mould material and the curing characteristics, and investigated the drying rate, the moisture and the curing fluidity according th the variations of the temperature and the drying media recycle volume which affects the mass transfer in the drying process. So, the result are summarized as follows: ① As the drying temperature increased to 70℃, 80℃ and 90℃ respectively, the drying rate became fast. ② In the same final drying time, the higher the drying temperature became, the more the moisture content of the urea resin mould material inceased. ③ Accordingly as the drying temperature increased, the moisture content of the drying material suddenly decreased in short drying time, but the moisture content increased when the drying time was between 80 minute and 120 minutes. ④ As the drying temperature increased, the curing fluidity of amino resin mould meterial decreased. ⑤ As the recycle volume of the drying media increased, the curing fluidity decreased.

내장된 정적 메모리의 고장 시뮬레이션에 관한 연구

최재욱,이재훈,민형복 成均館大學校 科學技術硏究所 1999 論文集 Vol.50 No.2

While embedded memories contribute to enhanced process performance, they also complicate testability. The testing of embedded memories is a time consuming exercise, because accessing the memories from off-chip is difficult, if not impossible. Existing Logic Fault Simulators do not simulate embedded memory, but just simulate pin faults. It is believed that the testing of embedded memories are due to Built-in Self-test. In this paper, realistic fault models which can be occurred in real memory are considered first, then functional memory fault simulator for that fault models is implemented. Mathematical fault model is not considered, but realistic fault model is considered and data structure that is called "fault effect" is used for reasonable usage of memory for fault simulation.

Hydroxy Propyl Methyl Cellulose의 자연발화에 관한 연구

최재욱,목연수,하동명 한국화재소방학회 2001 한국화재소방학회논문지 Vol.15 No.4

HPM의 자연발화는 일정한 주위온도에서 자연발화의 연구와 Godbret-Greenwald가 고안한 전기로에서 운상상태의 최소발화온도를 구하였으며, 시료를 용기에 충전했을 경우 용기의 크기가 클수록 발화한계온도는 낮아졌으며, 겉보기활성화에너지는 Frank-Kamenetskii의 열발화이론으로부터 계산하였고, 운상상태의 발화온도는 21%의 산소농도하에서 최소발화온도를 구하였으며, 산소농도 변화의 실험결과 산소농도 10%에서 발화되지 않았으며 한계산소농도를 구할 수 있었다. The spontaneous ignition of hydroxypropyl methyl cellulose(HPMC) was investigated at constant ambient temperature in the oven and minimum ignition temperature of dust clouds with Godbret-Creenwald Furnace respectively, In the experiments of the vessel filled with sample, the larger the vessel was the lower the spontaneous ignition temperature and ambient temperature was calculated from the Frank-Kamenetskii thermal ignition theory, The minimum ignition temperature for the dust cloud state was found under 21% oxygen concentration. At the experiment with the change of oxygen concentration, HPMC was not ignite at 10% O2 and so the limiting oxygen concentration was obtained at 10%. Keywords : Spontaneous ignition, Ambient temperature, Minimum ignition temperature Frank-Kamenetskii thermal ignition theory

활성탄을 사용한 플라즈마 반응에 의한 NOx의 처리에 관한 연구

최재욱 釜慶大學校 2001 釜慶大學校 論文集 Vol.6 No.-

In this experiment, we studied about concentration characteristics of NOx in the reactor of corona discharge type and combined reactor of ozone absorption activated carbon type by using mixed gas of NO/N_2 and N_2/O_2. In the case of corona discharge type reactor, when the first stage concentration of the NOx was high, the concentration of the NOx increased from the first stage of discharge input power, and the case of ozone absorption activated carbon, even when the concentration of NOx and discharge input power increased, the concentration of NOx suddenly decreased. And at the same reactor, when the first stage concentration of NO increased, the decrease rate of NOx was slowed. When the concentration of initial NO increase, generation of ozone decreased and in the case of same concentration of NO, according to discharge input power increase, generation of ozone increased.

반복 작업 근로자들에서의 경견완장애에 관한 연구

최재욱,염용태,송동빈,박종태,장성훈,최정애 大韓産業醫學會 1996 대한직업환경의학회지 Vol.8 No.2

본 연구는 근골격계 질환중에서 대표적인 질환인 경견완장애를 대상으로 일부 제조업 및 전화교환수 근로자에서의 경견완장애의 유병실태 파악, 경견완장애의 정확한 분류 및 향후 진단기준의 개발에 필요한 기초적인 자료 수집에 목적을 두었다. 조사대상은 반복동작에 폭로되는 생산직 근로자 98명, 모전화국의 전화교환수 115명을 대상으로 근골격계 증상호소, 이학적 검사 및 신경학적검사와 기타 혈중 효소등의 임상검사 및 악력의 차이 등을 조사하였다. 조사대상 사업장 중 B사업장은 전자부품을 생산하는 사업장으로, 제품 조립라인의 작업형태는 주야 2교대 근무이며, 앉아서 하는 작업과 서서하는 작업이 혼재 되어있다. A사업장은 전화교환작업, 즉 컴퓨터단말기를 취급하는 작업으로 전원 앉아서 하는 작업이며, 주야 2교대 작업이다. 조사대상 집단의 일반적 특성은 다음과 같다. A사업장 근로자의 평균 연령은 37.9세, 평균 근속년수는 17년이며, B사업장은 평균 연령 37.7세, 평균 근속년수 10.4년이었다. A 사업장은 대상 근로자 115명이 전원 여자였으며, B사업장은 대상근로자 98명 중 남자 68(69.4%)명, 여자 30(30.6%)명이었다. 조사 결과는 다음과 같다. 사업장별 자각 증상 호소율은 A 사업장의 경우 경부 85.2%, 견관절 81.7%, 주관절 34.8%, 완관절 73.0%의 순으로 특히 경부 및 견관절, 완관절의 증상 호소율이 높았으며, 반면 B 사업장은 경부 51.2%, 견관절 56.1% 주관절 23.5%, 완관절 31.3%의 순이었다. 근속년수별 자각증상 호소율은 경부와 견관절의 자각증상 호소율이 40%이상으로 주관절 및 완관절의 지각 증상 호소율에 비해서 상대적으로 높았으며, 경부와 완관절은 근속년수가 증가함에 따라 자각증상에 호소율이 통계적으로 유의하게 증가하였다. A 사업장, B 사업장 모두 최소 22.8% 이상의 근로자(증상 경험자중)가 병원이나 약국을 방문하여 치료를 받았다고 응답하였으며, 사업장 간의 차이는 보이지 않았다. 조사 대상자 전원에게 신경학적 검사와 근전도 검사를 포함한 정밀건강진단을 실시하였다. 정밀건강진단 결과 A 사업장은 질병자가 10명(8.6%), 요주의자가 31명(26.9%), 재검자가 2(1.7%)이었으며, B 사업장은 질병자가 16(16.3%), 요주의자가 12명(12.2%), 재검자 2명(2.0%)이었다. 이러한 이상자의 질병별 유형은 긴장성 경부증후군에 해당하는 사람이 46명으로 이 중 질병자는 13명, 요주의자 30명 재검자 3명이었으며, 수근관증후군은 16명으로 질병자 3명, 요주의자 8명, 재검자 5명이었다. 기타 드퀘르뱅씨병은 5명으로 질병자 4명, 요주의자 1명이었으며, 외측상과염 3명, 이두근개건염 3명, 회전근개건염 3명, 내측상과염 2명, 경추디스트증후군이 5명 등이었다. 사업장별로는 A 사업장의 경우 긴장성경부증후군이 11명, 수근관증후군이 8명, 드퀘르뱅씨병 3명, 경추디스크증후군이 1명이었으며, B 사업장은 긴장성경부증후군이 35명, 수근관증후군이 8명, 드퀘르뱅씨병 2명등의 순이었다. 이러한 결과는 A 사업장의 경우 작업 조건이 의자에 앉아서 실시하는 컴퓨터 작업인데 반하여 B 작업장은 대부분 기립작업, 반복 조립으로 이러한 작업조건에 차이에 기인하는 것으로 판단된다. 경견완장애의 이상소견과 관련이 있는 성별, 연령, 빈도 위험도 점수 및 힘 위험도를 독립변수로 설정하여 다단계 로지스틱 회귀분석을 실시하였다. 경견완장애 이상소견에 통계적으로 유의한 영향을 미친 변수는 성별(p=0.0005), 연령(p=0.0093)이었으며, 힘위험도는 p값이 0.0567, 빈도위험도는 0.0983으로 유의하지 않았다. The purpose of this study is to investigate the current status of and to collect the basic informations of musculoskeletal diseases of upper extremities in manufacturing and telecommunication companies. The subjects were 213 workers, consisted of 98 manufacturing workers and 115 telephone operators. The musculoskeletal symptom survey, job safety analysis(JSA), and medical examinations including neurologic and nerve conduction velocity(NCV) test were conducted. All workers were women in company A, while the other composed of 68(69.4%) men and 30(30.6%) women. The results were as follows: 1. The rates of self-reporting symptoms in each company were 85.2% at the neck, 81.7% at the shoulder joint, 73.0% at the wrist joint and 34.8% at the elbow joint in company A, while 56.1% at the shoulder joint, 51.2% at the neck and 23.5% at the elbow joint in company B in order. 2. No relationship was observed between the work duration and symptom rate in company A, but the highest symptom rate was observed at the neck in 10-19 year work duration group, at the shoulder, elbow and wrist joint in 5-9 year work duration group in company B. 3. Over the 22.8% of total workers in this study having symptoms got medical treatment at the medical clinics or drug stores, but there was no statistical difference between both companies. 4. In company A, 16(13.9%) workers were classified as D category, 12(10.4%) workers as C category and 2(1.7%) workers as R category among 115 workers. And D category was 10(10.2%), C category 31(31.6%) and R category 4(4.0%) among 98 workers in company B. D category means disease category needed futher treatment, C category means disease category needed no treatment and R category means recheck category needed futher evaluation. 5. The types of musculoskeletal disorders including D, C, and R category were 46 cases(D 13, C 30, R 3)of tension neck syndrome (TNS), 16 cases(D 3, C 8, R 5) of carpal tunnel syndrome (CTS), 5 cases of De Quervain's disease, 3 cases of lateral epicondylitis, 3 cases of bicipital tendinitis, 3 cases of rotator cuff tendinitis, 2 cases of medical epicondylitis, and 5 cases of cervical disc syndrome. 6. In company A, the total cases of 11 TNS, 8 CTS, 3 De Quervain's disease, 3 lateral epicondylitis, 3 rotator cuff tendinitis and 1 cervical disc syndrome were diagnosed and so were total cases of 35 TNS, 8 CTS and 4 cervical disc syndrome in company B. 7. By stepwise multiple regression analysis with dichotomization of musculoskeletal disease, the following odds ratios were significantly high(p<0.05)-sex(2.707) and age (1.926).

안면부에 발생한 고정형 스포로트리쿰증 3례

최윤애,류영욱,정재봉,송준영,이규석 啓明大學校 醫科大學 1993 계명의대학술지 Vol.12 No.3

We experienced 3 cases of fixed type cutaneous sporotrichosis confined to the face. Case 1 was a 32-month old child, affected over the nose. Case 2 was a 25-year old man, affected over the left cheek. Case 3 was a 71-year old man, affected over the nose. Histopathologically, chronic granulomatous inflammation with pseudoepitheliomatous hyperplasia was observed. Mycologically, typical dark brown to black colored colonines with moist, wrinkled and membranous surfaces were cultured. All patients were completely cured by oral administration of saturated KI and itraconazole combined therapy in a short period(40-90 days).

유방암의 뇌하수체 전이에 의한 양안 시력소실 1 예

최낙원,안명주,김재민,박동우,박용욱 한양대학교 의과대학 2000 한양의대 학술지 Vol.20 No.1

Pituitary gland metastasis is a rare clinical diagnosis, usually made in the setting of known primary systemic cancer with widespread metastasis to other organs. But visual loss as a presenting symptom of metastasis to the pituitary gland is unusal. We report here a case of 45-year-old woman who had been diagnosed as having metastatic breast cancer involving bone and liver 2 years ago, and received high dose chemotherapy with peripheral blood stem cell transplantation, developed sudden bilateral complete visual loss. At initial presentation, the patient had no light perception and no pupillary response to light in both eyes, but without evidence of panhypopituitarism, or diabetes insipidus. Brain MRI showed a large enhanced mass invasion to the cavernous sinus and extension to the suprasella portion without dura or base-of-skull metastasis. Pathologic examination showed metastatic breast cancer. Despite the transsphenoidal decompression surgery of metastatic tumor, the visual loss was not improved.

축전지 사업장에서 공기 중 납 농도의 허용노출기준 초과율 변화에 관한 연구

최재욱,김남수,함정오,이병국 순천향대학교 의학연구소 2007 Journal of Soonchunhyang Medical Science Vol.13 No.2

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입상활성탄의 자연발화 특성에 관한 연구

최재욱,김상렬 東亞大學校 大學院 1993 大學院論文集 Vol.18 No.-

The characteristics of critical spontaneous ignition of granulated activated carbon were investigated at a constant ambient temperature and sinusoidally varying ambient temperatures. As the results of the experiments, the critical spontaneous ignition temperature at the sinusoidally varying ambient tem-peratures was generally lower than that at the constant ambient temperature. At the critical spontaneous ignition temperature decreased as the period increased. The critical Frank-Kameneskii's parameter δ?(εω) was determinded from the results. δ?(εω) = δ?{1-379 exp (-0.935·ω?)} δ?(εω) = δ?{1-381 exp (-0.930·ω?)} δ?(εω) = δ?{1-388 exp (-0.929·ω?)}

HPLC를 사용한 쌀 중 잔류농약 동시분석법

최재천,이영자,김소희,최수영,최희주,정성욱,박흥재,김우성 한국환경과학회 2005 한국환경과학회지 Vol.14 No.4

A simple and sensitive analytical method based on RP-HPLC with UV detector(225 nm) and mobile phases using 0.1% phosphoric acid and acetonitrile was developed for simultaneous determination of quinclorac, bentazone, 2,4-D, bensulfuron-methyl, dymuron, capropamide, pencycuron, ethofenprox. This method was resulted in recovery of 78~ 96% with RSD 3.3~7.5%. LODs 0.12~0.84 and LOQs 0.34~1.20 ㎎/L. Calibration curves were linear with r of 0.9995~ 0.9999.