• 제목/요약/키워드: Harmful air

검색결과 418건 처리시간 0.027초

Occupational Diseases Among Office Workers and Prevention Strategies

  • Lee, Jongin;Koo, Jung-Wan
    • 대한인간공학회지
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    • 제34권2호
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    • pp.125-134
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    • 2015
  • Objective: In this review we discuss the health effects among office workers. Background: Even if office workers are not exposed hazardous or harmful environment frequently, some problems could be happened to the office workers. Although serious occupational diseases rarely occur to the office workers, it is important to consider occupational risk factors for the office worker because the portion of the office workers is relatively high in all industries. Method: We divided possible health effects for the office workers into three categories; musculoskeletal disorders, indoor environment, and cerebro-cardiovascular diseases. We reviewed related articles, textbooks, and statistical materials non-systematically and described risk factors, related illnesses, and prevention strategies on each category. Results: Office workers have various musculoskeletal disorders to be intervened. By medical treatment, improving working environment, and ergonomic intervention, office workers can be prevented from musculoskeletal injuries. Poor indoor environment can cause many building-related illnesses or sick building syndrome. Although the etiology of some problems by poor indoor environment is not clear, it helps to maintain adequate humidity, temperature, and clarity of indoor air. Cerebro-cardiovascular diseases are a rising issue because office workers in Korea tend to work for a lot of time. To prevent the diseases, it is needed to work for adequate time, lengthen activity level, and manage other medical risk factors for the diseases. Conclusion: There is no distinct occupational disease for office workers. However, there are some aspects to consider the health effects of office workers and it is important to prevent the possible health problems. Application: A strategy against occupational diseases among office workers can be established by reviewing this article.

Automatic Control Of Dissolved Oxygen In Activated Sludge Aeration Tank

  • Park, Kwang-Soo;Heo, Nam-Hyo;Lee, Hae-Goon;Han, Gee-Baek;Kim, Chang-Won
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제3권2호
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    • pp.113-119
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    • 1999
  • The quality of the effluent from an activated sludge aeration tank can deteriorate when the substrate removal rate decreases due to an abrupt reduction in the DO concentration, which is affected by such operating conditions as the loading rate, temperature, wastewater composition, and so on. In this research, a DO control system that includes a PI (proportional-integral) controller/Hiraoka controller was developed and applied to a pilot-scale activated sludge process, then its acceptability was estimated. The applicability of the respiration rate to DO control was also estimated. The respiration rate indicated a variety of input organic loading rates, which is the main disturbance to the DO concentration in an aeration tank. When the influent concentration incrementally decreased and increased between CODcr 1,000 mg/l and 100 mg/l, the control system with a PI controller exhibited a good llperformance-the average DO concentrations were 2.00$\pm$0.14 mg/l and 1.88$\pm$0.15 mg/l (set value was 2.0 mg/l), respectively, and the settling time was just 10 minites. When the control system was operated for 4 days, the DO concentration was 1.99$\pm$0.18 mg/l and 32.6% of the air flowrate was saved. However, the fluctuations in the respiration rates and air flowrates were severe, which could be harmful to the stability of the biomass and mechanical stability of the blower. A possible approach to solve this problem may be the simultaneous control of the loading rate and DO concentration.

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알레르기性 鼻炎에 對한 文獻的 考察 (The Bibliogrphical Study on the Allergic Rhinitis)

  • 김현아;정지천
    • 한방안이비인후피부과학회지
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    • 제7권1호
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    • pp.53-84
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    • 1994
  • The study has been carried out to investigate of the Allergic Rhinitis by referring to 87 literatures. The results were as follows; 1. In oriental medical science, Allergic Rhinitis is belong to the category of the 'BiGu'(鼻구) 'GuChe'(구체). The 'Gu'(구) of the BiGu means watery rhinorrhea, the 'Che'(체) of the GuChe means sneezing. 2. The cause of a disease summarize the weak of Lung, Spleen and Kidney, and invasion into the nasal cavity of PoongHan etc a wrong air. Sometimes the pathologial change appear PoongHan changeHwa(風寒化火), HwaYeol is hidden in the inside(火熱內伏). The contributing factors are found a season(spring, winter), an abnormal weather(運氣 : 少陰 少陽 陽明 司天, 歲金不及), an emotional stress, an external wound of the harmful air, a food allergens and fatigue, a contact of substances, a sunlight etc. 3. Predominant symptoms are watery rhinorrhea, sneezing and nasal obstruction. Sometimes accompanic symptoms are nasal bleeding, mucopurulent rhinorrhea, olfactory disturbance, nasal polyp, rhinolalia clausa, respiratory disfunction etc. 4. The treatment-methodes is as follows, OnBoPaeJang GeoPoongSanHan(溫補肺臟 祛風散寒), GeonBilkGi(健脾益氣), BoSinNabGi (補腎納氣). The treatmentherbs is as follows, OnBoJiLuDan GaGam(溫補止流丹 加減), OkByeongPoongSan plus ChangIJaSan GaGam(玉屛風散合 蒼耳子散 加減), BoJungIkGiTang GaGam plus SoCheongLyongTang(補中益氣湯加減 配合 小靑龍湯), SinGiHwan GaGam(腎氣丸加減), GaeJiTang(桂枝湯) etc. 5. The external treatment is as follows, JeokBi(滴鼻), ChuiBi(吹鼻), SaekBi(塞鼻), stick and herbs-injection on the acupuncture-point, pressure ear acupuncture-point, herbs-pillow etc. 6. The acupuncture-moxa treatment is as follows, the methodes of cure apply TongJoGyeongGi(通調經氣), SanTongBiGui(宣通鼻竅) etc. Predominent acupuncture-points are YoungHyang(迎香), InDang(印堂), BiTong(鼻通), SangSeong(上星), HabGok(合谷) and so on. As mentioned above, from now on, it's need to the oriental medical scientific study of the Immunity and Allergy and to the external treatment's application for the ascent of the treatment-effect of the allergic disease.

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우리나라 이동오염원의 제어기술의 동향과 발전방안 (Air Pollutants Control Technique Trends for Transportation Sources in Korea)

  • 김정수;엄명도
    • 한국대기환경학회지
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    • 제29권4호
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    • pp.477-485
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    • 2013
  • The major source of harmful air pollutants in Korea have been shifted as economy grows. Particulate matter(PM) and Sulfur dioxide ($SO_2$) emitted from industries and coal-fired domestic sectors were important pollutants in 1970's and later industrializing period of Korea. Then the characteristic of pollution was changed into so-called "developed country type pollution". Vehicles have been responsible for significant amount of Nitric oxide ($NO_x$) pollution and consequent Ozone formation in urban area since 1990's. Variety of control measures have been introduced to deal with the vehicle emissions in Seoul Metropolitan Area (SMA). Emission control technologies have successfully reduced pollutants from vehicles. Three-way catalyst for vehicles fueled by gasoline and liquefied petroleum gas (LPG), for example, has achieved large amount of pollutants. Compressed natural gas (CNG) urban bus have penetrated existing diesel bus market and reduces PM and $NO_x$ emissions in many Korean cities. However, diesel vehicles are still reaming as a critical emission source of urban area. Diesel vehicles gain more popularity than ever because of their better fuel efficiency and driving power. Unfortunately, it is widely known that the pollutant emissions of diesel vehicles are much larger than those of gasoline and LPG vehicles. In this note, we briefly introduce the trends of emission control strategies which are accomplished by automotive industries for about last ten years. Emission regulation, cleaner fuel, diesel particulate filter (DPF) and other measures are discussed from technical as well as legislative perspectives.

대기온도에 따른 휘발유 자동차의 배출가스 특성에 관한 연구 (A Study on the exhaust gas characteristics of the vehicle gasoline according to the ambient temperature)

  • 임재혁;김기호;김성우;이민호;오상기
    • 동력기계공학회지
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    • 제19권6호
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    • pp.47-53
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    • 2015
  • Korea is the geographic location during the summer, the temperature rising to $35^{\circ}C$ and winter temperature is $-15^{\circ}C$ to reduce the air temperature changes, such as relatively large compared to other countries. This increase or decrease of the harmful exhaust gas discharged from automobile substantially inconvenience a significant impact on the active side of the car engine temperature and exhaust gas reducing device receives a large impact on the atmospheric temperature is regulation to be different. However, domestic vehicle emissions test temperature of $20{\sim}30^{\circ}C$ is it does not reflect this situation the actual test temperature to accurately measure the exhaust gas volume of the vehicle is difficult. In this study, domestic automobile exhaust gas test conditions of a test temperature $20{\sim}30^{\circ}C$ various temperatures, including (35, 25, 0, -7, -15, $-25^{\circ}C$) under the two vehicles (2.0L MPI, 2.4 L GDI) as was discussed with respect to the exhaust gas characteristics of the vehicle according to the ambient temperature gas. As a result, domestic emissions test temperature of $25^{\circ}C$ than average conditions were temperature decreases greenhouse gas emissions and increase overall increased by up to 15 times higher. Air temperature and the engine exhaust gas inconvenience a direct effect on the activation temperature required in the reduction unit is determined to be an increase of emissions and greenhouse gases, and also an increase in the variety of lubricants based lubricating and viscosity reduction, such as the engine oil due to the low temperature of these result It is considered that shows the.

3차원 가상착의 시스템을 활용한 남성용 커버롤 도장 작업복의 작업동작 적합성 평가 (The Evaluation of the Work Motion Suitability of Men's Coverall Type Painting Work Clothes Using 3D Virtual Clothing Simulation)

  • 박진아
    • 패션비즈니스
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    • 제24권4호
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    • pp.63-84
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    • 2020
  • It is essential to consider the heavy industrial working environment factors which are regarded as harmful to workers' health and safety and suitable work motion factors for the workers' motion while developing the work clothes for painting workers in the machinery and shipbuilding industries. This study suggests the use of 3D virtual clothing simulations as a solution to protect the human body from hazardous working conditions accompanying the development of painting work clothes and assessing the work motion performance associated with the comfort while workers wear them during the work clothes. The initial aim of the study is to examine a male avatar to run work motions simultaneously within a 3D virtual clothing simulator, secondly, to present the simulation images of coverall type men's painting work clothes with the application of two experimental painting work motions and one control motion to the avatar, and finally, to present the distance analysis images of the painting work clothes and the avatar body and air gap rates through the analysis of cross-sections of the avatar body while wearing the coverall work clothes according to the work motions. The results showed that the distance degree of painting work clothes to the avatar body for each part of the human body when performing painting work motions. Moreover, 3D virtual clothing simulations enabled the creation of a male model avatar to run painting work motions together and the painting work clothes developed were found to be suitable for the painting work motions.

직분식 CNG 엔진에서 연료 분사시기의 변화가 연소 및 출력 특성에 미치는 영향 (The Effect of Fuel Injection Timing on Combustion and Power Characteristics in a DI CNG Engine)

  • 강정호;윤수한;이중순;박종상;하종률
    • 한국자동차공학회논문집
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    • 제15권1호
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    • pp.193-200
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    • 2007
  • Natural gas is one of the most promising alternatives to gasoline and diesel fuels because of its lower harmful emissions, including $CO_2$, and high thermal efficiency. In particular, natural gas is seen as an alternative fuel for heavy-duty Diesel Engines because of the lower resulting emissions of PM, $CO_2$ and $NO_x$. Almost all CNG vehicles use the PFI-type Engine. However, PFI-type CNG Engines have a lower brake horse power, because of reduced volumetric efficiency and lower burning speed. This is a result of gaseous charge and the time losses increase as compared with the DI-type. This study was conducted to investigate the effect of injection conditions (early injection mode, late injection mode) on the combustion phenomena and performances in the or CNG Engine. A DI Diesel Engine with the same specifications used in a previous study was modified to a DI CNG Engine, and injection pressure was constantly kept at 60bar by a two-stage pressure-reducing type regulator. In this study, excess air ratios were varied from 1.0 to the lean limit, at the load conditions 50% throttle open rate and 1700rpm. The combustion characteristics of the or CNG Engine - such as in-cylinder pressure, indicated thermal efficiency, cycle-by-cycle variation, combustion duration and emissions - were investigated. Through this method, it was possible to verify that the combustion duration, the lean limit and the emissions were improved by control of injection timing and the stratified mixture conditions. And combustion duration is affected by not only excess air ratio, injection timing and position of piston but gas flow condition.

제올라이트 콘크리트의 기초 물성에 관한 실험적 연구 (An Experimental Study on the Fundamental Properties of Zeolite Concrete)

  • 조병완;최지선
    • 한국구조물진단유지관리공학회 논문집
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    • 제16권1호
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    • pp.1-8
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    • 2012
  • 오늘날 첨단산업의 발전과 지구환경 문제의 심각성에 대한 인식이 증가하여 시멘트 산업에서도 다각화 측면에서 다양한 종류의 기술들이 활성화되고 있는 시점이다. 본 연구에서는 최근에 새로이 검토되고 있는 시멘트 대체 재료로서 천연제올라이트를 주원료로 사용한 제올라이트 시멘트 콘크리트에 관한 기초 물성에 대해 분석하는데 목적이 있으며, 악취 및 유독가스 제거기능이 우수하며 중금속, 암모니아와 같은 양이온성 오염물질을 제거하는 이온교환능, 흡착능, 분자체효과를 가지며 또한 다공성 물질이라 보온능력이 좋은 것으로 알려진 천연제올라이트와 알칼리 활성제(NaOH)의 양에 따라 콘크리트의 압축강도, 슬럼프, 블리딩 및 공기량 등을 실험하였다. 천연제올라이트 콘크리트의 압축강도 측정결과 거의 40MPa정도로 측정되었으며 슬럼프, 블리딩, 공기량 시험에서도 일반 콘크리트과 비슷한 성능을 나타내어 향후 고성능, 고기능성 건설재료로 사용 가능하다고 판단되어진다.

LNG 냉열 에너지의 지역 냉방 시스템에 관한 기반 연구 (A Basic Study on the District Cooling System of LNG Cold Thermal Energy)

  • 김청균
    • 한국가스학회지
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    • 제7권4호
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    • pp.36-43
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    • 2003
  • 본 논문에서는 LNG 냉열 에너지를 활용한 지역 냉방 시스템 가능성에 대해 고찰하고자 한다. 액상의 LNG는 기상의 가스로 변환하는 과정에서 많은 냉열 에너지를 발생한다. 최근에 빙축열을 이용한 건물의 냉방 시스템 구축과 심층수를 이용한 지역 냉방 시스템이 도심지의 기존 사무실 건물이나 대규모 건물의 냉방장치로 도입되고 있는 상황이다. LNG의 냉열 에너지는 기존의 냉매에 의존한 개별 냉방 시스템을 대체하는 새로운 냉열 에너지 공정으로 쾌적한 공간을 제공하는 천연의 대규모 냉각매체로 재사용될 수 있다. 버려지는 냉열 에너지는 낮은 코스트로 운영될 수 있는 중요한 청정 에너지원이기 때문에 냉방 시스템으로 개발되면, 기존의 에어콘 시스템에 견주어 볼 때 공기중에 유해한 오염원의 발생과 환경적으로 유해한 냉매 방출을 대폭적으로 줄일 수 있는 우수한 냉방 시스템이 될 것이다. 따라서, 본 연구에서는 냉열 에너지를 활용한 지역 냉방 시스템에 대한 환경 친화적 기본적 설계 개념, 여러 가지 냉방 시스템 성능에 대한 유익한 기반적 정보를 제공하고자 한다.

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커피 로스팅 공정에서 발생되는 향기물질의 유해성 고찰 및 노동자 건강보호 방안 (A Review on the Hazards of Flavoring Chemicals in Coffee Roasting Proces)

  • 임경택
    • 한국산업보건학회지
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    • 제29권2호
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    • pp.119-140
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    • 2019
  • Objectives: This study was based on the occurrence of a coffee roasting process-related disorder(bronchiolitis obliterans; published by NIOSH in the US) among workers exposed to chemicals called diacetyl in a coffee processing facility. Flavorings added to coffee contain diacetyl and 2,3-pentanedione, all of which are subject to exposure in a number of food manufacturing processes, including coffee roasting, grinding, and packaging. Therefore, this study aims to review the toxicity to workers related to food processing and food additive manufacturing to prevent occupational diseases. Methods: We surveyed the related literature, domestic and international references, and the status of relevant domestic and foreign professional organizations. The present situation of workers was investigated by reviewing literature on the safety and health of workers in the coffee roasting process using domestic and foreign literature and presentations. Expert advisory opinions were reflected, and experts were consulted by participating in domestic and overseas academic conferences. Results: Most of the fragrance materials for coffee were harmful and hazardous substances according to the GHS classification, and research was carried out through a second external consultation. A literature review on the measurement of air pollutant emissions from coffee roasters and the estimation of air pollutant emissions during coffee roasting examined the characteristics of pollutants emitted during coffee roasting. Conclusions: Two chemicals identified as causing bronchiolitis obliterans in the coffee roasting process are believed to explain why the disease is difficult to treat. This information can be used effectively in the future prevention of this disease. Future studies should clearly identify the potential for toxicity of alpha-diketones and the bases of OELs in relation to the occurrence of obstructive bronchiolitis, including measurement of various organic compounds and alpha-diketones from ground coffee, as well as various coffee grinds and coffee bean varieties. In particular, it is necessary to clarify the current understanding of the dose-response relationship between alpha-diketone and lung disease in workers involved in coffee roasting.