조선업 용접공의 용접흄 생애누적노출량을 이용한 환기기능 평가

정춘화,임현우,구정완,박정일 大韓産業醫學會 2002 대한직업환경의학회지 Vol.14 No.4

목적 : 조선업 용접공들의 용접흄 생애 누적노출량을 이용하여 그들의 환기기능을 평가하기 위하여 본연구를 실시하였다. 방법 : 1개 대규모 조선소에서 용접흠에 5년이상 노출된 남자근로자 241명과 대조군으로 사무직 남자 근로자 80명을 대상으로 개인별 생애 누적노출량을 산출하였고 환기기능으로서 노력성폐활량(FVC), 1초량(FEV_1), 1초율(FEV_1%), 최대중간호기 속도(MMF), 최고호기기류속도(PEER)와 호기 FVC의 50%, 75% 시점에서의 최대호기기류인 FEF_50, FEF_75를 얻고저 노력성 호기곡선과 최대호기기류-용량곡선을 측정하여 분석한 결과는 다음과 같았다. 결과 : FEF_50과 FEF_75의 예측치에 대한 백분율(%pred)의 평균은 노출군이 대조군보다 유의하게 감소하였고 MMF는 감소하는 경향을 보였다. 현재의 노출수준 증가에 따라 감소하는 유의한 환기지수는 없었다. 환기지수 중 MMF, FEF_50 및 FEF_75는 노출 기간이 길수록 유의하게 감소하였다. 노출수준×노출기간으로 산출한 용접흄 누적노출량(C1)이 증가함에 따라 최대노출군에서 유의하게 감소한 환기지수는 FEF_75 뿐이었다. 노출수준, 노출기간, 환기시설, 생산량, 보호구사용, 용접봉 및 와이어 종류 등의 변수들을 고려하여 산출한 용접흠 누적 노출량(C2)이 증가함에 따라 최대노출군에서 유의하게 감소한 환기지수는 FEF_75이었으며 MMF 및 FEF_50은 감소하는 경향을 보였다. 또한 환기지수중 MMF, FEF_50 및 FEF_75의 경우 생애 누적노출량(C2)이 증가함에 따라 비정상적인 환기기능을 보인 근로자 비율이 유의하게 증가하였다. 결론 : 본 연구결과는 노출 관련 요인들을 고려하여 산출한 생애 누적노출량(C2)을 이용하여 용접흠에 노출된 근로자들의 환기기능을 평가하는데 있어서 MMF, FEF_50 및 FEF_75가 유용한 지수이었다. Objectives : This study was conducted to evaluate the ventilatory function in shipyard welders using the lifetime cumulative exposure to welding fumes. Methods : Ventilatory function tests were performed on 241 male welders at one large shipuad. exposed to welding fumes for over five years, and was compared to 80 male control subjects. Ventilatory function indices, such as forced vital capacity(FVC). one-second forced expiratory volume(FEV), rato of FEV_1 to FVC(FEV_1%), maximal mid-expira-tory flow(MMF). peak expiratory flow rate(PEER) and maximal expiratory flow at 50 and 75% of expited FVC(FEF_50 and FEF_75), were obtained by analuyzing forced expiratory spirograms and maximal expiratory flowvolume curves that were simultaneously mea-sured by an Impulse ocillometry(IOS) program in the standing position. Results : FEF_50 and FEF_75 expressed as a percentage of the predicted values were significatly lower in the exposure group than in the controls, and the MMF tended to decrease. The mens of all the ventilatory indices, expressed as percentage of the predicted values, were not significantly increased at the current exposure levels. The MMF, FEF_+50 and FEF_75, expressed as a percentage of the predicted values, were significantly decreased with an increase in exposure duration. Onlu the FEF_75, expressed as a percentage of the predicted value, was significantly decreased with an increase in the cunulative exposure to welding fumes(C1). The FEF_75, expressed as a percentage of the predicted value, was significantly decreased with an increase in the cumulative exposure to welding fumes(C2), The above parameters were calculated to consider the durrent exposure level, exposure duration, application of the ventilator sustem, production rate, personal protection device, electrode and swelding wire. The MMF and FDF_50, expressed as a percentage of the predicted value, tended to decrease, The proportion of workers with abnormal MMF, FDF_50 and FDF_75 were significantly increased with an increase in the cumulative exposure to welding fumes(C2). Conclusions : These findings suggested that the MMF, FDF_50 and FDF_75 are sensitive and practical indices for the evaluation of the ventilatory function of workeers exposed to welding fumes, when the lifetime cumulative exposure(C2) is considered as a factor affedting exposure.

패각 폐자원을 활용한 악취제거기능을 갖는 폴리에틸렌 필름

전병철,정용찬,정미화,박정환,권오철 수원대학교 기능성생명소재연구소 2003 자연과학연구논문집 Vol.2 No.1

연간 250,000 톤 정도 생산되는 패각을 이용하여 악취제거기능을 갖는 폴리에틸렌 필름을 제조하기 위해, 패각 표면의 탄산이온을 바탕으로 양이온 또는 양이온성 계면활성제의 이온교환에 의한 표면흡착 및 이에 따른 표면 극성 변화를 통해서 악취제거능을 부여하였다. 패각 표면의 개질은 양이온성 계면활성제로서 DTAB (n-dodecyltrimethylammonium bromide), CTAB (n-cetyltrimethylammonium bromide), 그리고 DHAB(n-dihexadecyldimethylammonium bromide)를 사용하였다. 또한 양이온의 금속으로는 Ce3+, Mg2+, Al3+를 이용하여 계면활성제의 이온교환방법으로 표면을 개 질하였다. 표면개질된 패각 분말을 이용하여 LDPE와 패각 기준 20 wt%의 마스터 배치 (masterbatch, MB)를 제조한 후 다시 LDPE와 섞어서 패각 기준 3, 5, 10 wt%의 폴리에틸렌필름을 제조하였다. 생산된 필름의 규격은 폭 40 cm, 두께 40 μm 이었다. 제조된 패각 필름에 대한 기계적 물성 측정 결과 패각의 첨가로 인한 기계적 물성의 큰 저하는 관찰되지 않았으며, 순수 폴리에틸렌 필름 대비 80 % 이상의 물성을 유지하였다. 악취제거능은 양이온성 계면 활성제로 개질된 패각 필름이 시험된 모든 종류의 악취에 대하여 가장 우수한 악취 흡착 제거능을 보여주었으며, 개질되지 않은 패각 필름도 비교적 우수한 악취제거능을 보여주었다.

도시고형폐기물의 성분분석에 관한 연구

선정화,김희택,배성렬,강신춘 한양대학교 에너지·환경기술연구소 1994 에너지·環境技術論文集 Vol.1 No.-

도시지역에서 배출되는 일반폐기물에 대한 성분분석결과 밀도는 250∼300㎏/㎥, 수분함량은 중량비로 평균 51.83%, 가연성분 42.09%, 회분 6.08%로 각각 측정되었다. 한편, 저위발열량은 주거지역이 700∼1,700㎉/㎏, 상업지역이 2,000㎉/㎏이상으로 측정되어 상업지역이 주거 지역보다 발열량이 높은 폐기물이 배출됨을 알 수 있었는데 이는 수분함량이 높은 주개류의 배출이 상업지역이 주거지역보다 적으며 소비자 포장지로서 종이, 비닐, 플라스틱류 등의 사용이 많은데 기인하는 것으로 생각되어 진다. 한편, 분리수거, 유가품에 대한 자원 재활용, 연탄재 배출의 감소추세 등의 효과로 폐기물 중 불연성 함량은 줄어들고 반면 종이, 비닐, 플라스틱류 등의 가연성 폐기물의 함량은 크게 늘어 전체적으로 폐기물의 질이 향상되고 있음을 알 수 있다. The analysis results of components of municipal solid wastes are as follows : ① Density ranged from 250㎏/㎥ to 300㎏/㎥. ② Water content, combustible content and ash content measured 51.83%, 42.09%, 6.08% respectively. ③ Low calorific value was ranged from 700 to 1,700㎉/㎏ in residential area and measured 2,000㎉/㎏ in commercial one. Therefore, it was known that calorific value of wastes in residential area is smaller than that in commercial area. Also, the quality of wastes was improved by increase of combustible content which results from vitality of valuable recycling, reduction trend of briquette ash generation rate and increase of paper, plastic consumption as wrapping materials.

대구지역 거주자의 식생활 습관과 위장질환과의 관계

오미정,김수월,양희면,현재식,허천식,이명화 한국건강관리협회 2000 건협 Report Vol.3 No.-

지역사회에서 형성된 사회적 지지와 근로자의 사회심리적 스트레스간의 관련성

임화영,김형수,최영환,장성훈,이건세,정최경희,오원기,최재욱,정춘화 대한산업의학회 2006 대한직업환경의학회지 Vol.18 No.4

Objective: This study was performed to examine the relationship between community-based social support and psychosocial distress in workers. Methods: The study subjects were 596 workers recruited from 11 companies in Chungju city. A structured questionnaire was used to assess sociodemographics, health-related behaviors, job characteristics, job stress, work-based social support, community-based social support and level of psychosocial distress. Results: Hierarchical multiple regression analysis showed that workers with no chronic disease, exercise and sufficient sleep had a higher score of psychosocial distress than those with chronic disease, no exercise, and not enough sleep. Coworker's work-based social support and community-based social support were negatively associated with psychosocial distress. The R square value of total independent variables on psychosocial distress was 0.409, and that of community-based social support on psychosocial distress was 0.052. Conclusion: This study showed that community-based social support served as a protective factor against psychosocial distress in some workers. We recommend the establishment of a worksite stress reduction program in occupational level as well as community-based social support.

肢발생중 세포 증식성에 미치는 Etretinate의 영향에 관한 연구

황정연,김은영,박선화,전용혁 고려대학교 의과대학 1994 고려대 의대 잡지 Vol.31 No.1

Cell proliferation in the developmental sequence of fore-limb in the DDY mouse with the adverse effect of single dose of etretinate (Tigason®) on it correlated to the drug-induced dysmorphogenesis was studied by measns of argyrophil technique for nucleolar organizer regions(AgNORs) and expression of proliferating cell nuclear antigen(PCNA). The number of AgNORs per nucleus displayed regional differences in the limb bud on day 11 of gestation, as higher values in apical ectodermal ridge(AER) and growing tip but decreased rapidly thereafter compared with those in the other parts of epithelia and subepithelial mesenchyme, while in core mesenchyme where the higest in its value on day 11, the numbers decreased depend not on the age but on the chondrified stage specific. Antibody reaction to PCNA expressed in almost all of the cells, stronger in mesenchyme than in epithelia on day 11 and then decreased gradually with the development proceed. Siver reactions to NORs as well as PCNA expression were decreased sharply by etretinate but recovered gradually from 24 hours after treatment except the value of AgNORs in the chondrified mesenchyme. The results Indicate that growth conducted by AER with subridge mesenchyme and chondrification in the core mesenchyme are two of major processes in the early development of limb, and the adverse effects of etretinate on proliferation and differentiation persist longer in the chondrified area but decreased expression of proliferative activities by the drug do not appear to be the result subsequent to the drug-induced cell death. The results suggest that temporal inhibition or interruption of the proliferation could deprive the programmed sequence of development of its appropriate timing with subsequent disturbance of the pace in growth which might be a role of limb dysmorphogensis but the drug's affinity to the chondrified cells remains a question.

걷기운동이 비만중년여성의 건강관련체력과 피하지방두께변화에 미치는 영향

원영두,문현화,정천모,신명건 朝鮮大學校 스포츠科學硏究所 2007 스포츠科學硏究 Vol.18 No.-

The purpose of this study was to analyze the effect of walking exercise on health-related physical fitness and Subcutaneous fat thickness in obese middle-aged women. SPSS 11.0 was used to calculate mean and SD, and ANCOVA was conducted to examine the group difference between paired sample t-test and pre-test and post-test. The level of significance was set at a=.05. 1. The change of health-related physical fitness was examined, In the EG, there was no statistically significant difference in muscular strength, but there was statistically significant difference in muscle endurance(p<.05), f1exibi1ity(p<.01), and cardivascular endurance(p<.OOl). In the CG, there was no statistically significant difference in all factors. 2. The change of body composition was examined. In the EG, there was statistically significant difference in weight(p<.001) and % body fat(p(.001), but 3. The change of skinfold thickness was examined. In the EG. there was statistically significant difference in triceps. subscapular, midaxillary, abdominal, suprailliac, and popliteal muscles(p<.001) and front thigh(p(.01), but there was no statistically significant difference in medial calf. In the CG, there was no statistically significant difference in all regions. In conclusion, as results of conducting the 12-week walking exercise program for obese middle-aged women, it was found that the program improved health-related and effectively reduced % body fat and skinfold thickness. It is recommended that middle-aged women should do low intensity endurance exercise rather than excessive exercise. Further study should conduct a walking exercise program and a dietary cure together to provide obese middle-aged women with a more effective program.

Research Articles : Biomass Estimation of Gwangneung Catchment Area with Landsat ETM+ Image

( Jung Hwa Chun ),( Jong Hwan Lim ),( Don Koo Lee ) 한국임학회 2007 한국산림과학회지 Vol.96 No.5

Biomass Estimation of Gwangneung Catchment Area with Landsat ETM+ Image

Chun, Jung Hwa,Lim, Jong-Hwan,Lee, Don Koo Korean Society of Forest Science 2007 한국산림과학회지 Vol.96 No.5

Spatial information on forest biomass is an important factor to evaluate the capability of forest as a carbon sequestrator and is a core independent variable required to drive models which describe ecological processes such as carbon budget, hydrological budget, and energy flow. The objective of this study is to understand the relationship between satellite image and field data, and to quantitatively estimate and map the spatial distribution of forest biomass. Landsat Enhanced Thematic Mapper (ETM+) derived vegetation indices and field survey data were applied to estimate the biomass distribution of mountainous forest located in Gwangneung Experimental Forest (230 ha). Field survey data collected from the ground plots were used as the dependent variable, forest biomass, while satellite image reflectance data (Band 1~5 and Band 7), Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), and RVI (Ratio Vegetation Index) were used as the independent variables. The mean and total biomass of Gwangneung catchment area were estimated to be about 229.5 ton/ha and $52.8{\times}10^3$ tons respectively. Regression analysis revealed significant relationships between the measured biomass and Landsat derived variables in both of deciduous forest ($R^2=0.76$, P < 0.05) and coniferous forest ($R^2=0.75$, P < 0.05). However, there still exist many uncertainties in the estimation of forest ecosystem parameters based on vegetation remote sensing. Developing remote sensing techniques with adequate filed survey data over a long period are expected to increase the estimation accuracy of spatial information of the forest ecosystem.

Case study on operating characteristics of gas fueled ship under the conditions of load variation

Jung-Min Chun,Ho-Keun Kang,You-Taek Kim,Mun-Hwa Jung,Kwon-Hae Cho 한국마린엔지니어링학회 2016 한국마린엔지니어링학회지 Vol.40 No.5