유량변동에 따른 소양강유역 수질의 통계학적 해석

최한규,백경원,최용묵,최진우 江原大學校 産業技術硏究所 2001 産業技術硏究 Vol.21 No.B

This research was conducted with the aim of efficiently managing large scale of rivers such like Songyang-river through predicting water quality change with analyzing the characteristics of the flowing in nutrients and pollutants. The main result will be used as basic data for effectively operating reservoirs through controling water quality and quantity. The relationship between quantity of flow and water quality was analyzed and pollution loading into the basin was estimated. Three areas of Soyang-river upstream and one area of Suip-cheon in Yanggu-gun were selected as research sites. Flow and water quality were measured simultaneously. The relation between quantity of discharge and pollution concentration and between quantity of discharge and pollution loading were analyzed by statistical method, respectively. We provided a rating curve through measuring quantity of discharge(collection quantity of discharge)and pollutograph and pollution loading curve through water quality data. Also, we analyzed the correlation between quantity of discharge per unit area and pollution loading per unit area in each basin. As resurt of this research, Buk-cheon spot revealed an excellent first grade water quality for the items including BOD5, DO, and SS. The correlation coefficient between Buk-cheon spot's quantity of discharge and pollution loading was 0.896~0.996, showing the validity of analysis applying correlation curve formula of quantity of discharge and pollution loading in the same spot. Also, pollution loading per unit area of the items including BOD5, COD, DO, SS, T-N, T-P increased as area of basins get increased following the sequence of Buk-cheon, Suip-cheon, Naelin-cheon spots.

조선업 도장작업자의 유사노출군과 노출변이; 크실렌 노출을 중심으로

고상백,노영만,임현우,신용철,김수근,최홍열,김재용,장성훈 大韓産業醫學會 2001 대한직업환경의학회지 Vol.13 No.4

목적 : 조선업 도장 작업자의 크실렌 노출을 평가하기 위하여, 수행직무 및 밀폐특성에 따라 유사노출군으로 구분하여 노출 변이 및 동질성을 파악하고자 하였다. 방법 : 3회 이상 반복측정이 이루어진 근로자 중동일공정에서 직무상 변동이 없는 근로자 총 28명을 대상으로 하였다. 노출농도 값을 대수전환(lOgtransformation)하여 근로자간, 근로자내 노출 분산요소을 추정하기 위하여, nested randomeffects ANOVA model을 활용하였다. 선정된 유사노출군 내 구성원의 측정 평균이 동일하다고 할수 있는지를 검정하기 위하여 분산요인(9f)을 산출하였고, 쿨즈0.031일 경우 동일하다고 생각하였다.또한 노출 값을 대수전환하여 95 %의 근로자(b-R9s)가 2배수 범위 내에 측정값을 가질 경우 동일하다고 생각하였다. bwRSS의 값을 유사노출군내의 근로자들간(between worker)의 기하표준편차(bwsy)를 구한 후 exp(3.92 bwsy)로 계산하여 산출하였고, 그 값이 2이하이면 동일하다고 생각하였다. 결과 : 일반적으로 유사노출군은 노출농도가 비슷한 것이라는 생각과는 달리, 직무에 근거한 유사노출군은 동질성 검정상 이질적이었다. 분무도장과 붓도장 모두 bwRss은 2를 초과하였고, 룰 또한 0.031를 초과하여 변이 폭이 컸다. 그러나 밀폐특성에 따른 노출 분포의 변이성은 직무만으로 구분했을 때의 변이지표 보다 그 수치가 낮아 밀폐특성으로 직무의 변이성을 설명 할 수 있었다. 결론 : 직무에 근거한 유사노출군이 동질적이지알다는 결과는 유사노출군으로 구분된 근로자의 업무특성이 하나의 유사노출군으로 설정할 수 없다는 점을 시사한다. 따라서 향후 작업환경 측정 시 직무뿐만 아니라 특정 업무(specific task) 또는 세부작업현황까지 파악할 필요성을 제시하고 있다. Objectives : This study was conducted to assess the concentration of xylene exposure and exposure variability of a similar exposure group (SEG) in accordance with job title and confined space. Method : The study subjects included 28 workers working in the painting process in the ship-building industry. Measurement of subjects were repeated three times. Within and between-worker exposure valiance components were estimated from log-transformed exposure concentrations employing a one-way nested random effects analysis of variance model. A uniformly exposed group was defined as one where the between-worker variance(σB2) was less than or equal to 0.031 or bwR95 ≤2, where bwR95 =exp(3.92 bwSy) , representing the radio of the mean exposures of the 97.5th and 2.5th percentile groups of the workers sampled. Result : The results indicated that, contrary to popular belief, similar exposed groups based on job title were heterogeneous. The between-worker variance(σB2) is large(≥0.031) and the ratios of the 97.5th and 2.5th percentile workers of the log normally distributed exposures of each group of worriers was more than 2. However dividing job title into confined space (in-block, out-block, in/out-block) decreased the between-worker exposure variability. Conclusion : This study focused on the quantitative aspects of exposure in painters in the ship-building industry. We cannot accept the assumption that SEG are uniformly exposed, as a major component of variation in exposure relates to differences in tacks or other factors. Therefore, the observational schemes can be improved by investigating Job-specific task and practice.

화재감지센서용 PZN-PSS-PZT계 초전재료의 전기적 특성에 미치는 MnO₂첨가제의 영향

金龍赫,白東鉉,崔逸壽 (社)韓國火災 ·消防學會 1995 한국화재소방학회논문지 Vol.9 No.2

In this study, the effect of MnO_2 additive on the electrical characteristics of PZN-PSS-PZT Pyroelectric materials for the fire detactor was studies. PZT ceramics used this experimental is 4 composite system [Pb(Zn_1/3 Nb_2/3)O_3 +Pb(Sn_1/3 Sb_2/3)O_3+PbTiO_3+PbZrO_3]. The dielectric constants and dissipation factors decreases as to MnO_2 concentration increases. At the MnO_2 0.5(ωt%), Pyroelectric coefficient shows 8(10^-8C/cm^2℃) which have the highst value among other additive contents. It is found that output voltage maximum peck at MnO_2 0.7(ωt%) is associated with the higher pyroelectric coefficient and Lowered dielectric constant.

생체분해성 망막압정을 이용한 망막고정에 대한 실험적 연구

김용백,민병무,김창식,박근성,김승영,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Biodegradable retinal fixation devices obtain mechnical fixation of the retina with desirable chorioretinal scarring and with the potential for local, sustained release of antimetabolites and steroids to inhibit proliferative vitreoretinopathy. We manufactured a biodegradable retinal tack with barb that was designed in order to prevent intrusion from implantation of retinal tacks. This study was carried to evaluate the efficacy for retinal fixation and the capability for sustained release of drugs with a newly designed biodegradable retinal tack Biodegradable retinal tacks were made of polymers of glycolic acids and were designed with barbs in a shape to prevent the disinsertion. Biodegradale retinal tacks are divided into 3 parts, a conical portion that is inserted into the sclera, a cylinder portion that remains in the vitreous, and a neck portion between the pin and the cylinder. The tapered conical end was manufactured to allow easy insertion through the retina and choroid into the sclera. A cylinder portion was manufactured with a tapered angle that fixes firmly into the orifice of 19 gauge spinal needle. A neck portion, 0.4 mm in diameter, was designed to prevent disinsertion from following implantation of retinal tack. The applicator was a 19 gauge spinal needle and its orifice was prepared to 15°angle to accept the tapered cylinder portion of the retinal tack. The retinal tacks, secured in the needles, were passed through the formed vitreous and inserted into the retina, choroid, and sclera and were released by pushing the internal needle, usually within 2-3mm of the medullary ray of the posterior rabbit retina A retinal tack was placed in each of 8 pigmented rabbit eyes. Slit-lamp biomicroscopy, indirect ophthalmoscopy and fundus photography were performed periodically from 1 day to 8 weeks after surgery. Eight eyes were enucleated and studied by light microscopy at 8 weeks. Biomicroscopic evaluation of the animals revealed edemas adjacent to the retinal surfaces immediately after insertion of the biodegradable retinal tacks in all the animals. These edemas disappeared after 1 week. The first noticeable change in the size of retinal tacks was shown after 2weeks. The size of the retinal tacks gradually got smaller, decreasing to about one-half at 4 weeks and about one-third at 8 weeks. All retinal tacks remained in inserted places without any movement for an 8 week period. On light microscopy, epiretinal proliferations were seen to extend into the vitreous cavity. Cellular capsules that lined the inner aspect of the scleral defect caused by tack insertion were found. However the adjacent retina had a normal cytologic appearance and architecture in all specimens. We manufactured a biodegradable retinal tack that is designed to prevent intrusion from implantation of retinal tacks. All biodegradable retinal tacks reduce in size with time, but no retinal tacks extruded from the inserted place. The newly designed biodegradable retinal tack can be used for retinal fixation and may be used as a vehicle for the introduction of pharmacologic agents to prevent the cellular events that promote proliferative vitreoretinopathy.

Mo¨ssbauer 분광법에 의한 Mg-Cd 페라이트계의 자기적 성질 연구

홍치유,최달하,문용식,백승도 東國大學校 1988 論文集 Vol.27 No.-

In this study, the magnetic properties of Mg_(1-X)Cd_(X)Fe₂O₄ ferrite system has been studied by Mo‥ssbauer spectroscopy. All the samples, prepared by a ceramic sintering method, were found to be single phase spinel by X-ray diffractometry. The Mo‥ssbauer spectra. for x<=0.3, show two magnetic hyperfine splittings. one due to Fe^3+ octahedral site ions and the other due to tetrahedral site ions. While for x=0.4 spectrum shows relaxation behaviour and for x>=0.5 it exhibits quadrupole splittings. This result implicates that the magnetic properties of Mg_(1-X)Cd_(X)Fe₂O₄ferrite system change from ferrimagnetics to paramagnetics as increasing x, And the x, Cd content, dependence of Mo‥ssbauer parameters (isomer shift, quadrupole splitting, magnetic hyperfine field and line width) were investigated.

동형 모더나이트 상에서 일산화탄소 산화반응에 대한 속도론

정명수,이창용,최고열,하백현 漢陽大學校 環境科學硏究所 1989 環境科學論文集 Vol.10 No.-

모더나이트에 동을 이온교환 및 담지시킨 후 환원·산화 처리를 하여 동의 상태를 변화시킨 촉매에 대해 일산화탄소 산화반응의 속도론적인 고찰을 행하였다. 이온교환 촉매나 담지촉매 모두 동의 상태와는 관계없이 일산화탄소에 관한 반응차수는 1차이고 산소에 관한 반응차수는 0차였다. 이온교환 촉매의 경우는 수소로 환원시켜 동이 금속상태로 존재할때와 이를 재산화시켜 산화동 상태로 존재할때는 활성화에너지가 각각 16.4 및 20.3으로 비교적 큰 값을 나타냈으나 동의 담지촉매의 경우는 동이 금속일 때나 산화물 상태 모두 12∼13kcal/mole로 비슷한 값을 나타냈으며 이온교환 촉매보다 상당히 감소함을 알 수 있었다. 이와 같은 결과는 이온교환 촉매의 경우는 동이 제올라이트내부에 대부분 존재하는 반면, 담지촉매의 경우는 제올라이트 결정 표면에 존재하기 때문에 활성을 증가시키는 것으로 생각된다. Kinetics of oxidation of carbon monoxide over copper mordenite was carried out at the temperature range between 373K-443K in the micro-catalytic reactor. The experimental results indicated that the reaction order, with respect to carbon monoxide and oxygen was first and zero order respectively, regardless of the valence states such as copper metal, copper ion and copper oxide on the mordenite. The activation energy for metal-copper mordenite which is obtained by the ion-exchange revealed 20kcal/mol. But if this was reoxidized under the oxygen it decreased to 16.6kcal/mol. The activation energy of metal-copper mordenite which was obtained by impregnation and its reoxidized one under the oxygen were 12.2kcal/mol and 13.3kcal/mol respectively.

봉독약침이 류마티스 관절염 환자의 관절 통증, 종창 및 급성 염증 반응에 미치는 영향

이상훈,이현종,백용현,김수영,박재경,홍승재,양형인,김건식,이재동,최도영,이두익,이윤호 WHO COLLABORATING CENTRE FOR TRADITIONAL MEDICINE 2003 東西醫學硏究所 論文集 Vol.2003 No.-

Objective In order to study the effects of bee venom(BV) on the pain, edema, and acute inflammatory reactant of rheumatoid arthritis(RA) patients. Methods Patients with RA who met the ACR(American College of Rheumatology) 1987 revised criteria for the diagnosis of RA were treated with the BV therapy twice a week for 3 months. Tender Joint counts, swollen joint counts, Visual analog scale(VAS), morning stiffness, ESR. C-reactive protein(CRP) were analyzed before and after BV therapy. Results The results as follows. 1. Tender joint counts in patients after BV therapy were significantly lower than those before BV therapy(9.0±7.9 vs 15± 11.4, p=0.002). 2. Swollen joint counts of the patients after BV therapy were significantly lower than those before BV therapy(50±61 vs 15±23, p=0.001). 3. VAS in patients after BV therapy was significantly lower than those before BV therapy(608± 17.6 vs 380± 159, p=0.000). 4. Duration of morning stiffness in patients after BV therapy was significantly reduced compared with that before BV therapy(119.1± 112.6 min vs 59.0±89.7 min, p=0.009). 5. ESR and CRP were not significantly changed before and after BV therapy, suggesting BV itself could make inflammatory reaction as well as therapeutic effect. Conclusions BV therapy improved tender joint counts, swollen joint counts and duration of morning stiffness in this study, and further study is needed on long-term effect of BV therapy.

기초화장용 제품 중 크림과 로션제의 안정성 평가방법

조혜영,이석,백승희,최후균,이용복 한국약제학회 2003 Journal of Pharmaceutical Investigation Vol.33 No.4

This study was attempted to develop the physicochemical and morphological stability test methods for the cream and lotion formulations among the cosmetic foundations and to provide the guidance for the stability methods with respect to basic emulsions and creams. With these developed stability test methods, we can evaluate the expired date or life time of the available basic cosmetics, especially basic lotions and creams. Also, the stability test methods established in this study can be used as a guideline to test physical and morphological stability of cosmetics in the future. Thus, we selected two types of basic cosmetics such as lotions and creams made by four different cosmetic companies and applied them to stability test methods depending on the temperature changes such as temperature cycling and freezing-thawing cycling test. After the temperature changes, the conductivity, turbidity, particle size, creaming ratio and pH changes of the creams and lotions were evaluated and morphological changes such as crystal formation, oder, color and feeling of the creams and lotions were also tested. As the results of the stability tests, all the tested creams and lotions except for one lotion were stable. Therefore, it may be concluded that these short-term accelerated stability tests as physical stability test depending on the temperature change study were suitable for the stability testing methods for the basic cosmetics and may be useful for the establishment of the guideline for the stability test of cosmetics.

생체분해성 고분자를 이용한 사시수술용 제형개발 및 효용성에 대한 연구

민병무,김용백,김승영,김창식,박근성,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

A new device, muscle clamping system was developed to facilitate exact quatifying technique A strabismus surgery, and reduce the risk of complications. The device is composed of a lower fixing body with three jaws and an upper supporting body. They are used to clip an extraocular muscle and fix it to the sclera with a single bite. Superior rectus recession on 16 rabbit eyes were performed with this new device. Conjunctival injection, muscle adhesion strength, and light microscopic findings were examined at 1, 2, 4 and 8 weeks postoperatively. The Conjunctival injection were minimal, adhesion power ranged from 420 to 600 gram gravity, which is sufficient in withstand the normal pull of human extraocular muscle. In microscopic exam, some Inflammatory cells and fibrosis were found. The new device was technically easy, fast, and accurate, so it may be useful in stabismus surgery.

심장수술 시 농축적혈구, 자가수혈기 혈액, 체외 순환기 혈액에서의 유리 혈색소 농도 비교

송장호,구승우,백종화,정용보,이정순,최인철 대한마취과학회 2002 Korean Journal of Anesthesiology Vol.43 No.5

Background: Intraoperative autotransfusion or residual blood in a cardiopulmonaty bypass (CPB) circuit has been used to reduce the need for an homologous blood transfutsion during cardiac surgery. However, it may contain some free hemoglobin released from damaged cells. The load of blood containing free hemoglobin may cause renal dysfunction. We measured the amount of free hemoglobin in backed blood, cell saver blood and CPB blood to evaluate what is the least hemolytic blood transfused in cardiac surgery. Methods: This study was performed in 20 patients undergoing cardiac surgery. In each patient, the banked blood, intraoperative salvaged blood with a cell saver and CPB residual blood were sampled at the end of the operation. The concentration of free hemoglobin, hemoglobin and platelet counts were measured in these blood samples and percent of hemolysis was calculated (%hemolysis = [free hemoglobin] / .free hemogloben + hemoglobin]) Results: In salvaged blood with a cell saver, CPB residual blood and banked blood, hemoglobin concentrations were 20.1 ± 2.7 g/dl, 8.0 ± 1.1 g/dl, and 22.2 ± 2.7 g/dl, respectively. Free hemoglobin concentrations were 336.6 ± 239.5 mg/dl, 49.2 ± 26.8 mg/dl, and 279.5 ± 167.5 mg/dl respectively. Platelet counts were 26.1 ± 22.2 × 10^3/mm^3, 116.8 ± 56.5 × 10^3/mm^3, and 94.9 ± 43.6 × 10^3/mm^3 respectively. % Hemolysis were 1.6 ± 1.1%, 0.6 ± 0.4%, and 1.2 ± 0.7% respectively. In the comparison between the salvaged blood with a cell saver and CPB residual blood, free hemoglobin concentration, % hemolysis, and platelet counts had positive correlations (r = 0.8, 0.7, and 0.6). Conclusions: In twenty cardiac surgeries, CPB residual blood had a lower free hemoglobin level than the other two blood groups. The platelet counts in CPB residual blood were higher than those in cell saver blood but did not differ from those in banked blood. Therefore, CPB residual blood was the least hemolytic blood among the three blood groups when a transfusion was performed in cardiac surgery. (Korean J Acesthesiol 2002; 43: 588~593)