• International Journal of Automotive Technology
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• 제3권3호
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• pp.111-115
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• 2002

Suddenly increasing numbers of automobiles result in making worse air pollution problems. In particular, the emissions from automobiles affect badly on atmosphere. Nowadays, research on catalyst converter and filter trap as a modem technology is very active because PM is designated as a major cancer material and stringent regulations on this are necessary and required. The ceramic filter is very efficient in reducing particular materials up to 80-90% and is evaluated as a very efficient after-treatment technology. However, it comes with decreased engine performance due to increased back-pressure occurred by thermal crack. In order to solve these problems, several methods are proposed such as fuel additive, electric heater and burner types. This experimental study has been conducted with equipped and unequipped a ceramic filter on a displacement 11,000cc diesel engine and compared in terms of engine performance and emission. To measure the emission, D-13 mode is applied and measured quantities of the exhaust gases, particularly in CO, HC, PM, and NOx. Therefore, this research is focused on the basic mechanism and characteristics on harmful materials generated by ceramic filter.

• 자원환경지질
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• 제13권4호
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• pp.229-239
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• 1980

A various kinds of harmful gases in the gallery and the increasing quantity of in-flow water are the important factors causing mainly the decline in production. In this thesis, the increase and decrease of in-flow water which effects the out put have been investigated and analysed in the statistical method. Through the results obtained together with the stastistical data some typical interreation formula between the quantity of in-flow water and production have been induced and the productive percentage in season was examined with special reference to Changsung Coal Mine. The formulas are as fallows: (1) Underground in-flow water to production; $Y=-5.74x^2+108.9x+6,346.6$ where, Y: production(tons/day): x:in-flow water($m^3/min$), (2) Rain and Snow fall to production; P=6.555-1.591 R+1.282S where, P;production(tons/day); R:rain fall(mm); S : snowfall(cm), (3) Productivity ratio in season compared with the average annual production; 1st quarter of year:100.1%, 2nd quarter of year: 100.3%, 3rd quarter of year: 97.2%, 4th quarter of year: 102.4%.

• 동력기계공학회지
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• 제17권5호
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• pp.13-22
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• 2013

This paper reports the investigation of the physical and chemical characteristics of the prepared 3Pt-2MgO-$3ZrO_2$-$2CeO_2/Al_2O_3$ DOC, based on its hydrothermal aging. As a result of impregnating and reducing the $H_2PtCl_6$ $6H_2O$ precursor on a ${\gamma}-Al_2O_3$ basis, it was well dispersed into small particles with the range 2-3nm. This was because the $Al_2O_3$ acted as a barrier to prevent movement of the catalyst particles. For a hydrothermally aged catalyst for 9h at $700^{\circ}C$, its performance when purifying harmful gases decreased compared to a fresh catalyst, but its specific surface area was at the same level. This was because the performance of the catalyst was reduced by the sintering of the precious metal Pt, rather than by washcoat sintering and pore clogging. For an excessively hydrothermally aged catalyst for 9h at $850^{\circ}C$, Pt grew into an approximately 50nm class, formed a cluster compared to a fresh catalyst. The $CeO_2$ promoters also formed clusters among components of the same type, reducing their specific surface area to $114m^2/g$, which was 14% less than a fresh catalyst.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.365-370
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• 2009

LCA is a tool to support for making decisions by offering information of environmental aspects of products or services. It can be used to make decisions to consumers and NGOs as well as government and enterprises. LCA evaluates the environmental aspects throughout the entire life cycle of a product. Therefore it can quantify and assess environmental impacts from raw material acquisition, manufacturing, distribution, use and disposal to end of life and recycling. The demands of the recycling rate increase and the use of suitable materials for RoHS, REACH, WEEE, ELV which are linked trade with environmental regulation have increased the worldwide. Global warming is the critical challenge of the world facing. And under post-Kyoto protocol each country has to prepare for target reduction, so it became essential to save energy and resources. In addition that, the carbon mark has been run as the way of showing example of CO2 reduction in domestic and it will be extended gradually. And also through the introduction of Eco-label, environmentally-friendly product will be promoted. When those systems are operated, global warming gases (i.e. CO2) can be calculated throughout the entire life of the products by LCA. And the environmental impacts such as harmful material emission in the process of manufacturing, energy consumption, distribution and so on, can also be assessed. Therefore, The basic concepts of LCA technique and various cases and the practical application in the future will be review in this study.

• 박물관보존과학
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• 제7권
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• pp.75-87
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• 2006

국립중앙박물관은 2005년 10월 개관과 더불어 수장고 및 전시실의 안정한 보존 환경관리시스템을 확보하였다. 우선 수장고 및 전시실의 온습도와 유해가스를 주기적으로 측정하여 유물에 안정적인 환경을 유지하면서, 전시진열장 등 유물에 유해한 영향을 줄 수 있는 전시보조 재료(천, 종이, 페인트, 풀 등)를 테스트(Oddy test)하여 안정한 재료를 선정하고자 하였다. 또한 생물학적 피해를 미연에 방지하기 위해 수장고 전체를 훈증하였으며, 수장고에 주기적으로 곤충모니터링 트랩을 설치하여 생물에 의한 피해를 예방하고 있다.

• 한국추진공학회지
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• 제17권6호
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• pp.38-47
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• 2013

기존에 사용되어 온 추진제들은 연소 시 많은 양의 유해가스 발생으로 환경적인 문제점이 있다. 본 논문에서는 이러한 문제점을 개선하기 위하여 고체 연료로 적용 가능한 tetrazine 계열의 저탄소 고질소 화합물인 TATTz와 BTATz에 대한 합성공정을 확립하였다. 또한, 문헌에 빠져있는 구체적인 공정법 및 특성 분석 결과를 서술하였다. 합성된 모든 물질들은 분광분석 (NMR, IR)을 이용한 구조분석, DSC를 이용한 열분석, 측정된 밀도와 계산된 생성열을 근거로 폭발속도, 폭발압력 등을 계산하였다(EXPLO5).

• 산업경영시스템학회지
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• 제37권1호
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• pp.41-49
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• 2014

The purpose of this study is to examine the green management evaluation criteria and Employee Awareness and analyze their impact on management performance. A survey was conducted using a questionnaire form that was given to companies with fewer than 300 regular workers and less than 30 billion won in sales. The three-step mediated effect analysis proposed by Baran and Kenny was performed to verify the roles of the parameters. The research results are summarized as follows. First, awareness of greenhouse gases and environmental pollution play a mediating role affecting the management performance. Second, awareness of harmful chemical substances play a mediating role affecting the management performance. Lastly, The survey subjects were limited to SMEs in Chungcheong province and thus, this may not be applicable to all companies.

• 센서학회지
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• 제29권6호
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• pp.382-387
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• 2020

Hydrogen (H₂) is considered as a new clean energy resource for replacing petroleum because it produces only H₂O after the combustion process. However, owing to its explosive nature, it is extremely important to detect H₂ gas in the ambient atmosphere. This has triggered the development of H₂ gas sensors. 2-dimensional (2D) graphene has emerged as one of the most promising candidates for chemical sensors in various industries. In particular, graphene exhibits outstanding potential in chemoresistive gas sensors for the detection of diverse harmful gases and the control of indoor air quality. Graphene-based chemoresistive gas sensors have attracted tremendous attention owing to their promising properties such as room temperature operation, effective gas adsorption, and high flexibility and transparency. Pristine graphene exhibits good sensitivity to NO₂ gas at room temperature and relatively low sensitivity to H₂ gas. Thus, research to control the selectivity of graphene gas sensors and improve the sensitivity to H₂ gas has been performed. Noble metal decoration and metal oxide decoration on the surface of graphene are the most favored approaches for effectively controlling the selectivity of graphene gas sensors. Herein, we introduce several strategies that enhance the sensitivity of graphene gas sensors to H₂ gas.

• 한국정밀공학회지
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• 제18권1호
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• pp.123-128
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• 2001

The function of SCR system in refuse incineration plant is to reduce the harmful combustion gases especially NOx which make serious environmental pollution. The SCR system normally have a NOx measurement system such as inlet NOx analyzer and outlet T.M.S.(Tele Monitoring System) to control the outlet NOx in stack. The NOx measurement system is very important, however there are frequently happened sensing problems and it need maintenance periodically. In this paper, we propose an estimation method of inlet NOx of SCR system by using general structured observer. The inlet NOx is considered as an input disturbance and it is modelled by applying FFT method in frequency domains. Through the design of general structured observer, the outlet NOx can be estimated by using observation error between real outlet NOx and estimated outlet NOx. The effectiveness of the proposed method is shown by comparing to a measured inlet NOx data.

• 한국추진공학회지
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• 제23권5호
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• pp.53-59
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• 2019

고체연료는 추진제 연소 시 산화제와 반응하여 추진제 성능을 증가시키는 역할을 한다. 대표적인 고체연료는 Al, RDX, HMX 등이 있다. 이들 물질은 연소 시 수분과 만나 흰색 연기를 발생시키고, 일산화탄소, 이산화탄소, 메탄가스 등의 환경유해 물질을 다량 발생시킨다. 이러한 문제를 해결하기 위해 본 연구에서는 고체 연료로 사용 가능한 고질소 에너지 물질인 hydrazinium 5-aminotetrazolate(HAT)를 제조하였다. 분광분석(NMR)을 통해 HAT의 구조를 분석하였으며, DSC를 이용하여 열특성 분석을 하였다. 또한, EXPLO5 프로그램을 이용하여 비추력, 가스발생량 등을 계산하였다.