• 동력기계공학회지
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• 제13권6호
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• pp.29-34
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• 2009

Recently, we have a lot interest in a sudden rise of oil prices and a change weather for the earth warmming, so, development of new alternative fuels need in order to spare fossil fuel and reduce exhaust emissions for air pollution prevention. Biodiesel, which can be generated from natural renewable sources such as new or used vegetable oils or animal fats, may be used as fuel in diesel engine of compression ignition engine. In this paper, the combustion characteristics between neat diesel oil and biodiesel blends(10 vol.% biodiesel and 20 vol.% biodiesel) were tested using four stroke, direct injection diesel engine, especially this biodiesel was produced from soybean oil at our laboratory. This analysis showed that cylinder pressures, the rate of pressure rises and the rate of heat releases were decreased as the blending ratios of biodiesel to diesel oil increased because of lower heating value of biodiesel in spite of increased oxygen content in biodiesel.

• Journal of Ecology and Environment
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• 제32권3호
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• pp.207-215
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• 2009

Greenbelts were designated by the Korean government in 1971 in 14 large cities to prevent uncontrolled urban expansion. Recently, deregulation of the greenbelt system has resulted in further development, but the ecological role of greenbelts has not been fully considered when decisions about urban management are being made. We examined the ecological roles of the greenbelt system in the Seoul metropolitan area and prepared sustainable management and improvement plans based on our analysis of landscape characteristics using satellite images covering a ${\sim}30$-year period. The loss of forest cover during this period in the greenbelt areas was lower than that in the areas outside and inside of the greenbelt. Fragmentation of forest cover was correlated with the pattern of loss of forest cover. The NDVI of the greenbelt remained steady at 90% of that in outside of the GB for three decades. This suggests that the greenbelt system has performed its primary roles well. However, the remaining green space was not adequate to provide a sink for air pollutants even when the greenbelt area was included. We discuss how the negative effects of urbanization can be reduced through sustainable management and restoration to promote ecological functioning in greenbelts and urban landscapes.

• 한국인쇄학회지
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• 제22권2호
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• pp.199-211
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• 2004

The drying speed of gravure ink are very fast because of evaporation drying type. The gravure ink are fitly selected variety resin and solvent for a wide range printing are adopted. Moreover, after-manufacture handling is necessary to various purposes. Though composition of gravure ink are same those of another printing ink, the viscosity of it are vary low compare with another printing inks. As property of variety printed matters, improvement of performance of printing layer and suitable after-manufacture handling, the more research of gravure ink are to be continue for development of printing technology. Generally, the gravure ink are made up resin, pigment, solvent and additive. Especially solvent are fitly selected for solution of resin, viscosity, and drying speed. Furthermore, it tis care of bad smell of remaining resin, poison and danger of fire of it. Because of the prevention of air pollution as restriction deflation of solvent, custody of dangerous object and improvement of work environment as labor safety hygiene and fire-low, the environment restriction of printing business become strict. This study has purpose of development of gravure ink of involved 30% below of alcohol is used for PVC film printing.

• Journal of Advanced Marine Engineering and Technology
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• 제32권1호
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• pp.27-32
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• 2008

Recently, we have a lot of interest in alternative fuels to provide energy independence from oil producing country and to reduce exhaust emissions for air pollution prevention. Biodiesel, which can be generated from natural renewable sources such as new or used vegetable oils or animal fats, may be used as fuel in diesel engine of compression ignition engine. In this paper, the test results on specific fuel consumption and exhaust emissions of neat diesel oil and biodiesel blends(10 vol.% biodiesel and 20 vol.% biodiesel) were presented using four stroke, direct injection diesel engine, especially this biodisel was produced from soybean oil at our laboratory. This study showed that Soot and CO emission were decreased as the blending ratios of biodiesel to diesel oil increased, on the other hand NOx emission was slightly increased because of the oxygen content in biodiesel. Also, the biodiesel blends yielded slightly higher specific fuel consumption than that of diesel oil because of lower heating value of biodiesel.

• Advances in concrete construction
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• 제9권2호
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• pp.139-147
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• 2020

This paper reports the effect of Rice Husk Ash (RHA) in geopolymer concrete on strength, durability and microstructural properties under ambient curing at a room temperature of 25℃ and 65±5% relative humidity. Rice husk was incinerated at 800℃ in a hot air oven. and ground in a ball mill to achieve the required fineness. RHA was partially added in 10, 15, 20, 25, 30 and 35 percentages to fly ash with 10% of GGBS to produce geopolymer concrete. Test results exhibit that the substitution of RHA in geopolymer concrete resulted in reduced strength properties during initial curing. In the initial stage, workability of GPC mixes was affected by RHA particles due to the presence of dormant particles in it. It is evident from the microstructural study that the presence of RHA particles densifies the matrix reducing porosity in concrete. This is due to the presence of RHA in geopolymer concrete, which affects the ratio of silica and alumina, resulting in polycondensation reactions products. This study suggests that incorporation of rice husk ash in geopolymer concrete is the solution for effective utilization of waste materials and prevention of environmental pollution due to the dumping of industrial waste and to produce eco-friendly concrete.

• 환경위생공학
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• 제10권2호
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• pp.79-88
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• 1995

The electrostatic precipitation of Auto- Bias has the advantages of a little of power consumption by the voltage to apply only at ionizer and the prevention of fire danger by current flow over. As this ionizer wire was used WXN- Pt material of diameter 90$\mu $m, that improved ion efficiency and safety, simplified a existing source of electric power by induced Auto- Bias voltage. Also, the new type collector used electric conductivity- film wag superior a electric safety and dust collection efficiency and was possible to wash it by water. As a experiment result of this Auto- Bias electrostatic collector, the induced Auto- Bias voltage by appling D.C 4.0∼6.0kV at ionizer was 1.3∼2.3kV and then the power consumption by applied voltage was 8- l8W. The pressure loss of collector by the amount of flowing was 6.1 OmmH$_{2}$O in 300m$^{3}$/hr and showed a safe state of the dust collection. The collection efficiency by particle size was 65.1-95.8% in 0.5∼5.0$\mu $m. After corona discharge of ionizer, the remains ozone concentration was found much lower than that of ACGIH or air pollution criteria in Korea.

• 한국항해항만학회지
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• 제28권8호
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• pp.767-773
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• 2004

국제해사기구(International Maritime Organization ： IMO)에서는 선박에서 발생되는 오염물질 등에 대한 규제강화를 위하여 최근 새로운 해사환경협약의 채택 및 발효를 강력히 추진하고 있다. 우리나라는 국제해사기구의 A그룹 이사국으로서의 국제적인 위상과 해양환경 보호를 위하여 현재 발효되고 추진 중에 있는 협약들에 대한 연구와 대처를 효과적으로 하여야 한다. 이 논문은 해양관련 환경규제협약인 패기오염방지협약, 선박의 유해방오도료 사용규제협약, 밸러스트수 배출규제협약, 선박으로부터 오수에 의한 오염방지를 위한 협약 등의 주요 현안을 파악하고 분석하여 이에 따른 대응책을 제시하고자 한다.

• 도시과학
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• 제10권1호
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• pp.21-28
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• 2021

The purpose of this study is to examine the factors affecting the housing satisfaction of elderly households in comparison with non-elderly households, and to present policy implications in terms of housing welfare policies. For this purpose, this study used ordered logit model analysis using '2019 Housing survey data'. As a result of the analysis, in the case of individual/housing characteristics, the analysis results of the non-elderly household model and the elderly household model were similar. However, in the case of regional characteristics, non-elderly households living in the metropolitan area showed higher housing satisfaction than non-elderly households living in the non-metropolitan area, whereas the elderly households living in the metropolitan area had lower housing satisfaction than the elderly households living in the non-metropolitan area. In addition, the satisfaction variable of neighborhood/environmental characteristics that had the greatest impact on the housing satisfaction of non-elderly households was found to be crime prevention status satisfaction, and the satisfaction variable of neighborhood/environmental characteristics that had the greatest impact on the housing satisfaction of elderly households was air pollution satisfaction. The results of the analysis can be used as various reference materials when establishing housing welfare policies for elderly households.

• 한국환경보건학회지
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• 제43권1호
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• pp.71-76
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• 2017

Objectives: This study aimed to assess the environmental factors that affect particulate matters (PM10) and to compare with outdoor PM10 concentrations in an underground subway stations. Methods: The PM10 level was determined from May 2013 to September 2013 in the Seoul subway stations in four lines. PM mini-vol portable sampler sampler was used to collect PM10 for 6 hrs. Arithmetic means of PM10 concentrations with standard deviation (SD) were calculated. Paired t-test was used to compare the differences between indoor PM10 and outdoor PM10 concentrations with correlation analysis which was used to identify the association between indoor PM10 concentrations and environmental factors. Results: There were no different PM10 concentrations significantly between line 1, 2, 3 and 4 in an underground subway stations. Passenger number was positively associated with PM10 concentration while construction year was negatively associated with PM10 concentrations. Indoor PM10 concentrations were significantly higher than those in outdoor PM10 concentrations. PM10 concentrations were higher in the stations which were constructed before 1990s rather than the stations constructed after 1990s. Conclusion: PM10 levels in the underground subway stations varied greatly depending on the construction year. Therefore, it might need to be more careful management to the stations which constructed in before 1990s.

• 한국환경보건학회지
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• 제50권4호
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• pp.291-301
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• 2024

Background: Based on rapid industrial development, environmental pollution has emerged as a social problem and exposure to environmental diseases is increasing. The number of patients suffering environmental diseases in Daejeon Metropolitan City is also steadily increasing, and the prevalence of atopic dermatitis there is the highest in the country. Objectives: In order to minimize exposure to harmful factors for the prevention and management of environmental diseases, an environmental disease management system suitable for the environmental characteristics of each region is needed. Basic preliminary research should be conducted to identify environmental hazards in Daejeon Metropolitan City and establish a management system. Methods: Among the households (about 50 people) participating in the 2022 Indoor Environment Remote Measurement (IoT) program, households (children aged 5 or older and adults) with insufficient results for indoor air quality measurement and symptoms related to environmental diseases were selected. The subjects were tested for living conditions, blood tests, biomarker analysis (immunoglobulin E, Eosinophil count, histamine) and multiple allergy antigen tests (MAST, 93 types). Results: Participants were 53.7% female and 46.3% male, and the average age showed an even age distribution. IgE and eosinophil count were positively correlated, and significant results were found for atopic dermatitis and IgE (p<0.05). Typical risk factors observed in the survey was the amount of indoor ventilation, chemical exposure, heredity, house dust mites, fungi, and food. Conclusions: The purpose of this study was to help establish a regional management system for environmental diseases, research and diagnosis of environmental diseases. This study is meaningful in that it is a study with customized consulting suitable for the environment of Daejeon Metropolitan City. If the limitations are addressed and continuous research is conducted, it will be helpful for the management, diagnosis, and research of environmental diseases.