• 한국환경보건학회지
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• 제49권2호
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• pp.78-88
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• 2023

Background: Exposure to volatile organic compounds (VOCs) can have acute and chronic health effects on human beings in general and in working environments. In particular, VOCs are often emitted in large quantities in industrial settings. In such circumstances, there is a need to improve the indoor air quality at workplaces. Objectives: The purposes of this study were to verify the effectiveness of air cleaning devices in workplaces and provide alternative solutions for improving working environments. Methods: Personal exposure and area level of VOCs for workers were evaluated in a car-part adhesive process before and after installing an air cleaning device with a TiO₂-coated filter. Passive samplers and direct reading instruments were used to collect and analyze the VOCs, and the removal efficiency and improvement of air quality were evaluated. We also calculated the exposure index (EI) to assess the risk level in the workplace. Results: The removal efficiency for VOCs through the installation of the air cleaning device was approximately 26.9~69.0% as determined by the concentration levels before and after installation. The measured substances did not exceed the exposure limits for the work environment and the EI was less than 1. However, carcinogenic substances such as benzene, formaldehyde, carbon tetrachloride, and trichloroethylene were detected. Conclusions: The application of an air cleaning device can be a solution for controlling the indoor air quality in a workplace, particularly in cases where ventilation systems cannot be installed due to process limitations.

• 대한환경공학회지
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• 제33권3호
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• pp.183-190
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• 2011

소형방출챔버를 이용하여 반응조건(시료량, 온도, 환기횟수)에 따라 방향제에서 방출되는 휘발성 유기화합물의 배출특성을 조사하였다. 시료부하량($1.4{\sim}551.0g/m^2$)에 따라 방향제에서 방출되는 TVOC 방출량은 방출시험 5시간 후 $0.7{\sim}64.4mg/m^2{\cdot}hr$로 나타났다. Limonene, ${\alpha}$-pinene과 linalool 등 방향제에서 방출된 주요 휘발성 유기화합물은 온도와 환기횟수가 클수록 방출량이 증가한 것으로 나타났다. 이들 연구결과는 방향제와 같은 생활용품의 오염물질 방출시험방법 및 방출기준을 정립하기 위한 기초자료로 활용될 것으로 생각된다.

• 대한기계학회논문집A
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• 제37권8호
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• pp.1059-1067
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• 2013

자동차 연료탱크는 크게 본체와 본체에 조립되는 부품들로 구성되어 있다. 본체에는 차량 주행시에 연료탱크에서 발생되는 증발가스를 배출하고, 연료가 외부로 유출되는 것을 방지하기 위한 여러 밸브들이 조립되어 있다. 하지만 이러한 밸브들은 연료 넘침에 주된 원인으로 알려져 있음에도 불구하고 현재 증발가스의 배출과 기구적인 위치만 고려하여 설계되고 있다. 따라서 본 연구에서는 밸브들의 기존기능을 유지하면서 연료 넘침을 최소화 시키기 위해 근사최적설계를 적용하였고, 다구치 방법을 통해 실제 실험에서 근사최적설계의 유용성을 보였다. 결과적으로 최적화된 밸브 위치를 통해 개발기간과 비용을 절감하였고, 연료 넘침 최소화를 통해 자동차의 신뢰성을 향상시켰다.

• 유기물자원화
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• 제2권1호
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• pp.3-18
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• 1994

우리나라 도시고형폐기물은 퇴비화에 적합한 조건을 갖추고 있으나, 퇴비화 공정개발이 미약하여 폐기물 퇴비화를 실용화하지 못하고 있다. 폐기물 퇴비화의 실용화를 위하여는 최종퇴비의 질을 높이면서도 대량의 폐기물을 단기간에 처리할 수 있도록 공정제어를 하여야 한다. 이를 위하여 최적온도를 지속적으로 유지하도록 공기공급량을 제어하는 방식(온도제어 공기공급방식)이 있다. 본 연구에서는 우리나라 도시고형폐기물에 온도제어 공기공급방식을 적용하여 퇴비화 과정중의 공정효율과 최적온도를 분석하고자 하였다. 실험결과, 온도제어 공기공급방식이 일정공기공급방식에 비하여 짧은 기간에 분해효율과 건조효과가 높은 것으로 나타났다. 또한 우리나라 도시고형폐기물 퇴비화의 최적온도는 $50{\sim}54^{\circ}C$로 평가되었다.

• 한국환경보건학회지
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• 제3권1호
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• pp.27-44
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• 1976

This study was carried out to evaluate the harmful factors in working environments and to investigate the labor productivity after improvement of environments, surveying 93 industrial establishments of 10 industries located in Youngdeungpo industrial area in Seoul. The results obtained were as follows: 1) The highest noise level of 125dB(A) was indicated at the rolling process of transport equipment manufacturing industry. 2) The best illumination level was shown in precise machinery industry and the worst was indicated in rubber products, metallic products and transport equipment manufacturing industries. 3) Thermal conditions were above threshold limit value (TLV) at more than two processes of all industries except printing industry. 4) The highest dust concentration was determined in textile and wearing manufacturing industry. 5) Organic solvents were detected at 52 processes in 93 industrial establishments and 33 processes of them showed higher than TLV. The results about harmful chemicals were as follows: a) sulfur dioxide ($SO_2$)was determined higher than TLV on welding process of metallic product manufacturing industry and heat treatment process of transport equipment manufacturing industry. b) Carbon monoxide (CO) concentration was 700ppm at heat treatment process of transport equipment manufacturing industry, indicating 14 times of TLV. c) vinylchloride concentration in the air of PVC raw material mixing process and PVC preparation process of chemical product manufacturing industry was determined higher than TLV. d) Hydrochloride (HCl) concentration in the air of wire expanding process of transport equipment manufacturing industry was determined higher than TLV. 7) Higher values of lead concentration than TLV were determined at lead welding metallic product manufacturing industry and type planting process of process of printing industry, $1.8mg/m^3$ and $0.3mg/m^3$ respectively. 9) 22, 968 of 52, 855 workers (i.e. 43.5%) in 93 industries were exposed to various harmful agents. 10) It was found that the improvement of illumination in electric apparatus manufacturing industry (from 20~40 lux to 420 lux) resulted in an increase in productivity of 6.5% per capita and a decrease in faulty products of 19%. 11) Improvement of environments using local exhaust ventilation system resulted in a decrease of harmful substances lower than TLV and an increase in productivity of 11.4%. 12) Improvement of shovelling tools based on ergonomics resulted in a reduction in energy expenditure of 25.3% and an increase in productivity of 32.2% per capita.

• 한국태양에너지학회 논문집
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• 제27권3호
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• pp.55-61
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• 2007

This paper has been conducted to estimate cooling capacity of the dehumidification tower using hot water from a solar water heating system as a energy source of regeneration process when the dehumidification and drying system is applied to room cooling. A solar water heating system was operated and indoor temperature distributions were simulated according to weather conditions when the concerned solution was used to dehumidify room air in the dehumidification tower. Through this simulation researches we found th following results ; It was found that air velocity through supply and return diffusers should be controlled because it can cause uncomfort in dwelling area. It was found that in the sunny morning temperatures of dwelling area 1 and 2 are higher than those of dwelling area 3 and 4. In this research all the calculation results of heating and cooling system supported by solar water heater have confirmed that its cooling capacity could not reach PMV 0, thermal comfort.

• 한국대기환경학회지
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• 제29권5호
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• pp.625-633
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• 2013

This study attempted to find an alternative method for fine dust control in the pre-exiting facilities of metro-subway stations. A new double-layer design was proposed for the MVAC (mechanical ventilation and air control) system. Several filter lay-outs were combined a pre-filter with electret filter (EF), electret bundle filter (EBF), or electret pleated filter (EPF), and were then examined focusing on the collection efficiency of particulate matters and pressure drop across the filter layers. The experimental results from the lab and field tests showed the best collection efficiency with EPF, which achieved 85% for $PM_{10}$ and 55% for $PM_{2.5}$. It was also found from the long term field test that the new filter lay-out could provide quite consistent dust level particularly in underground platform regardless of external condition.

• 자동차안전학회지
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• 제8권1호
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• pp.26-30
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• 2016

The steel road wheel on ventilation holes was cracked in the vehicle durability test. But the component durability test by uni-axial, CFT(Cornering Fatigue Test) and RFT(Radial Fatigue Test) had been satisfied. That is, the uni-axial component test could not forecast the crack of vehicle. Therefore this study developed the bi-axial test mode to reflect a vehicle condition(to reflect both vertical and lateral force simultaneously) based on real load data which was measured in Europe and China and developed CAE simulation too. It reproduced the cracks same as vehicle's and verified by bi-axial test machine in the LBF(Fraunhofer Institute for Structural Durability and System Reliability) durability research center in Germany. Finally this the durability CAE simulation by using HMC(Hyundai Motor Company)'s the bi-axial test mode predicts feasibly the steel wheel's durability performance before vehicle durability test.

• 한국산업보건학회지
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• 제7권2호
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• pp.171-180
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• 1997

The objectives of this study were both 10 discuss the sampling method for airborne metalworking fluids(MWF)' mist and 10 suggest measures to minimize worker's exposure to carcinogen contained in metalworking fluids. In order to measure airborne MWF mist, it seems to be appropriate to use NIOSH Method #0500(filler weight) rather than NIOSH Method # 5026(analysis by FTIR). Because MWF mist on PVC filter evaporated and migrated during sampling, worker's exposure to MWF could be underestimated. So, when evaluating worker's exposure to MWF mist, other environmental conditions also must be considered. Enclosure and local exhaust ventilation system seems to he the most effective measure and must be constructed with process facility. In order to control worker exposure to carcinogens contained in MWF, distillation type and condition for crude oil, PAH concentration in MWF, and viscosity index of MWF must legally be described.

• 한국보건간호학회지
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• 제9권2호
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• pp.43-51
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• 1995

Many poeple has been engaged in industry is aware of the dangers from exposure to high intensity nose levels. The exposure to high intensity noise is encountered in a large number of situations. Laws governing the safety and health of employed people being to create a suitable working environment and eliminate unsafety practices and processes. Work areas should be designed and laid out so that they are satisfactory both from the environmental and safety points of view. In this connection safety also implies that noise is kept at a level which is not likety to cause hearing damage. This study was performed to measure the noise of press and assembly process in an automobile factory. and suggested the method of noise control. Consequently the effect ways of reducing level in working environment are as follows; 1. Changes to machines which would reduce noise generation. 2. Alteration of equipment to avoid impact in machinery and handing materials. 3. Enclosure of noisy machines or machine parts. 4. Mounting of attenuators on gas and air outlets as well as ventilation ducts. 5. Erection of sound absorbing screens. linings. and baffles in work areas. 6. The personal ear protectors can be chosen to protect the workers.