• 한국수소및신에너지학회논문집
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• 제14권3호
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• pp.276-282
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• 2003

A hydrogen enriched CNG engine can be stably operated at ultra lean condition and reduce emission extremely. It also has advantage to increase gradually the use of hydrogen for the coming hydrogen-energy age. In this studies, the combustion and emission characteristics of heavy-duty hydrogen-CNG engine were investigated to verify the enhancement of performance by enriched hydrogen into natural gas. The results showed that a hydrogen-CNG engine could achieve ultra lean operation and low emission, while power was reduced by the decrease of intake air flow.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2002년도 추계학술발표대회
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• pp.237-332
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• 2002

We constructed ceiling structure and floor structure for elevation of sound insulation performance of concrete slab of apartment house. And, we wished to measure heavy floor impact sound level and light floor impact sound level of these structure. As the result, light floor impact sound level interception performance of concrete slab was measured by thing that construction work of gypsum baud is important. Heavy floor impact sound level interception performance was measured by thing that it is effective that construct to thickness about 30 millimeters on concrete Slav. It was measured effectively that heavy floor impact sound level interception performance constructs rubber chip to thickness about 30 millimeters on concrete Slav.

• 한국환경과학회지
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• 제11권7호
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• pp.621-626
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• 2002

Depth-area-duration(DAD) relations are important to hydrological plans and designs for the water resources as well as the flood defence. And these relations have been still in analysis and use today because they can be applied to readily available data. In this paper, rational and consistent DAD models were developed using the multiple regression analysis and basic relationships of area ratio-runoff volume about heavy rainfall occurring in the Im-Jin river basin, 1999. In addition, revised DAD models and curves that can convert a maximum point rainfall to mean area rainfall were developed and evaluated. As results, these models seem to have predictive value in order to plan and design hydrological structures of flood defence in the Im-Jin river basin.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.785-787
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• 2004

The purpose of this paper is characteristic analysis of permanent magnet generator for AVR power of brushless synchronous generator. However, the PMG has a spoke type rotor with overhang, so we perform the analysis considering overhang for the precise airgap flux density. In this paper, dynamic analysis model with 2D FEM considering overhang is proposed by use of 2D, 3D static FEM results. The proposed method is verified by the results of PMG load test.

• 자원환경지질
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• 제54권3호
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• pp.331-352
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• 2021

The relationship of both heavy metals and major elements in soil, plants, and groundwater was studied in a hyper-arid area and depends completely on the groundwater to cover its all needs. The study reviles that 27.3% of the studied groundwater was strongly acidic and has very low pH values (

• 한국임상수의학회지
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• 제16권2호
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• pp.381-388
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• 1999

These investigations were performed to determine the causes of the reproductive disorders of the sows in a pig farm which was located at the distance 36m away from the detonation spot. The reproductive problems of the sows such as abortion and infertility occurred after consecutive detonation and use of heavy equipments to build 6 piers of the bridge for the expressway between Jinju and Taeieon during the period from July 1997 to October 1998. 1. The management condition of the farm, microorganism in the feed, inbreeding, hematological conditions, and viral agent causing abortion were not proved as the factors of the occurrence of abortion and infertility in the pig farm. 2. Theoretical concussion values according to the average amount of explosive per detonation were 1.16 kine for minimum amount (3.6 kg) and 3.45 kine for maximum amount(12.5 kg) of explosive, and the theoretical sound values were accordingly 92.29 decibel for minimum amount and 101.76 decibel for maximum amount of explosive, respectively, in the case of 36m distance between the detonation spot and pig farm. The frequency of detonation in a day was 7 times with interval of 15 minutes. 3. The occurence of infertility in the farm was 57.3% during the period of construction from July 1997 to August 1998. 4. In comparison of body weight of piglets between the damaged and not damaged farms, growth of piglets at the damaged farm was shown to be delayed over 30 days than those of not-damaged farm. In conclusion, abortion of 40 sows, delivery of whole still births of 22 sows, and infertility of 122 sows in the pig farm were assumed to be caused by the concussion or sound stress after consecutive detonation and use of heavy equipments.

• Safety and Health at Work
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• 제5권2호
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• pp.106-111
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• 2014

Background: The manufacture of paint involves a variety of processes that present with medical hazards. Safety initiatives are hence introduced to limit hazard exposures and promote workplace safety. This aim of this study is to assess the use of available control measures/initiatives in selected paint factories in Lagos West Senatorial District, Nigeria. Methods: A total of 400 randomly selected paint factory workers were involved in the study. A well-structured World Health Organization standard questionnaire was designed and distributed to the workers to elicit information on awareness to occupational hazards, use of personal protective devices, and commonly experienced adverse symptoms. Urine samples were obtained from 50 workers randomly selected from these 400 participants, and the concentrations of the heavy metals (lead, cadmium, arsenic, and chromium) were determined using atomic absorption spectroscopy. Results: The results show that 72.5% of the respondents are aware of the hazards associated with their jobs; 30% have had formal training on hazards and safety measures; 40% do not use personal protective devices, and 90% of the respondents reported symptoms relating to hazard exposure. There was a statistically significant (p < 0.05) increase in the mean heavy metal concentrations in the urine samples obtained from paint factory workers as compared with nonfactory workers. Conclusion: The need to develop effective frameworks that will initiate the integration and ensure implementation of safety regulations in paint factories is evident. Where these exist, there is a need to promote adherence to these practice guidelines.

• Safety and Health at Work
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• 제13권4호
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• pp.387-393
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• 2022

Background: Problem drinking is a perennial concern in the US fire service. A large literature has documented the importance of addressing alcohol norms in intervention research. The purpose of this study was to explore alcohol norms in a national cohort of firefighters (FFs) to inform intervention development in this occupational group. Methods: Data were from a national online survey of career and volunteer FFs (N = 674). Participants were recruited through national fire service listservs and a database of FFs who had agreed to be contacted for research. Results: When asked about "acceptable" levels of alcohol consumption, FFs on average suggested levels which exceeded public health guidelines. Further, approximately half of career and volunteer FFs believed that, at least under some circumstances, drinking until intoxicated was normative. When asked how long should elapse between a FFs last drink and reporting for duty, the average suggested lag was 11.2 hours (sd = 4.6). However, among male volunteer FFs who reported heavy drinking, the average was 6.68 hours (sd = 4.77). Conclusions: Given the high prevalence of heavy and binge drinking in the fire service, it is not surprising that the alcohol norms found in this study were consistent with a culture of drinking. Participants' reports of alcohol use among their peers were consistent with the actual prevalence of problem drinking. Thus, education and prevention efforts in this occupation should focus on changing norms about alcohol use, including linking heavy drinking to other health and safety issues they face.

• 한국지반환경공학회 논문집
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• 제5권2호
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• pp.5-13
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• 2004

아파트 건설용 부지내에서 중금속 및 유류로 오염된 토사가 발견되었다. 7개 위치에서 대표적인 시료를 채취하였으며 이 오염된 토사의 지반공학적 안정성을 확인하기 위하여 중금속 및 유류에 대한 환경공학적 검토가 이루어졌다. 2개 위치의 토사는 유류로 심하게 오염되어 있어 현장의 특정지역으로 반출하여 폐기해야 하는 것으로 판단하였다. 토양오염우려수준인 1개 위치의 토사에 대하여 성토재로서의 활용가능성을 확인하기 위하여 성토 안정성에 대한 해석을 수행하였으며 성토재로 사용할 수 있는 것으로 판단하였다.

• 한국습지학회지
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• 제14권3호
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• pp.365-374
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• 2012

양돈 농가에서 구리, 아연 등의 성장촉진제와 항생제들이 사료 첨가제로 사용되는데 사료에 주입된 많은양이 분뇨로 배설되고 있다. 국내 양돈 폐수의 90% 이상이 퇴, 액비 형태로 농지에 적용되고 있는 상황에서 퇴,액비 내에 함유된 중금속과 항생물질은 토양에 흡착되어 농지에 잔류하거나 지하수나 지표수로 유출되어 수계로 빠져나간다. 농지에 살포된 중금속과 항생물질의 토양 내에서의 거동을 살펴보기 위해 실험실 기초 실험을 수행하였는데, Jar test와 칼럼 용출 실험을 수행하였다. 실험결과 아연의 86.4와 구리의 68%가 토양에 흡착되는 것으로 나타난 반면, 액비에 포함된 항생물질의 60% 이상은 칼럼 유출수로 용출되는 것으로 나타났다.