• 분석과학
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• 제23권5호
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• pp.485-491
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• 2010

토양 중 유해원소 분석용 인증표준물질 KRISS CRM 109-03-SSD를 개발하였다. 인증 대상 원소는 현행 토양환경보전법에서 규제하고 있는 비소, 카드뮴, 크로뮴, 구리, 수은, 니켈, 납, 아연이다. 인증표준물질 제조를 위한 출발물질은 강원도 상동의 텅그스텐 폐광 광미 더미에서 채취하였다. 출발물질은 선별, 건조, 분쇄, 체거름, 혼합, 병입, 살균의 일련의 과정을 거쳐 제조한 다음 ISO Guide 35의 절차를 준용하여 인증하였다. 측정에는 동위원소희석 질량분석법(ID-ICP/MS) 및 기기중성자방사화분석법(INAA)을 이용하였다. 균질도 평가는 ISO 13528의 부속서 B를 준용하여 실시하였다. 인증값은 서로 다른 두 가지 측정방법에 의한 분석 결과 또는 동일한 방법이지만 독립적으로 2회 반복 시행된 분석의 결과로부터 결정하였다. 최종으로 비소, 카드뮴, 크로뮴, 구리, 납, 니켈, 아연 7개 원소에 대한 인증값을 결정하였다. 수은은 낮은 농도로 인해 균질도 요건을 만족시키지 못해 철, 텅그스텐과 함께 참고값으로 제공된다. 환경감시목적으로 많이 이용되는 ISO 11466에 따른 왕수에 의한 용출시험 또한 실시하였다. 용출시험은 공립시험소 및 대학 시험소 등 6개 기관의 공동분석으로 수행되었다. 용출시험의 실험실간 편차는 인증값의 불확도에 비해 크게 나타났다. 용출시험에 대한 공동분석 결과는 참고값으로 제공된다.

• 터널과지하공간
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• 제19권6호
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• pp.534-544
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• 2009

지표 하부 공동의 붕괴는 인간 활동의 대상인 도로 및 건물의 안정성에 영향을 미치는 지반침하를 야기할수 있다. 그러므로 이러한 지반침하를 사전에 예방하기 위해서는 지하공동 충전에 의한 지반보강공법의 적용이 필요하다. 본 연구에서는 장기적으로 친환경적인 칼슘알루미네이트 광물을 지반침하보강공법에 적용하고자 급결 충전물질 및 충전시스템, 급경사 광산채굴적 충전 손실 개선에 관한 현장적용성 연구를 수행하였다. 본 연구에서 개발된 급결 경화 충전물질은 급결 성능재료와 보조 재료로 구성된다. 개발된 재료는 급결 성능 및 수중 불분리 특성을 가지고 있어 수중공동에서 재료의 손실을 최소화하면서 효과적으로 지하댐을 형성하였다. Hg, Cd, As, $Cr^{6+}$, Pb와 같은 중금속 용출시험결과, 환경적으로도 적합한 물질로 분석되었다.

• 한국안전학회지
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• 제34권4호
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• pp.22-31
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• 2019

The flammable liquid conductivity is an important factor in determining the generation of electrostatic in fire and explosion hazardous areas, so it is necessary to study the physical properties of flammable liquids. In particular, the relevant liquid conductivity in the process of handling flammable liquids in relation to the risk assessment and risk control in fire and explosion hazard areas, such as chemical plants, is classified as a main evaluation item according to the IEC standard, and it is necessary to have flammable liquid conductivity measuring devices and related data are required depending on the handling conditions of the material, such as temperature and mixing ratio for preventing the fire and explosion related to electrostatic. In addition, IEC 60079-32-2 [Explosive Atmospheres-Part 32-2 (Electrostatic hazards-Tests)] refers to the measuring device standard and the conductivity of a single substance. It was concluded that there is no measurement data according to the handling conditions such as mixing ratio of flammable liquid and temperature together with the use and measurement examples. We have developed the measurement reliability by improving the structure, material and measurement method of measuring device by referring to the IEC standard. We have developed a measurement device that is developed and manufactured by itself. The test results of flammable liquid conductivity measurement and the data of the NFPA 77 (Recommended Practice on Static Electricity) Annex B Table B.2 Static Electric Characteristic of Liquids were compared and verified by conducting the conductivity measurement of the flammable liquid handled in the fire and explosion hazardous place by using Measuring / Data Acquisition / Processing / PC Communication. It will contribute to the prevention of static electricity related disaster by taking preliminary measures for fire and explosion prevention by providing technical guidance for static electricity risk assessment and risk control through flammable liquid conductivity measurement experiment. In addition, based on the experimental results, it is possible to create a big data base by constructing electrostatic physical characteristic data of flammable liquids by process and material. Also, it is analyzed that it will contribute to the foundation composition for adding the specific information of conductivity of flammable liquid to the physical and chemical characteristics of MSDS.

• Advances in concrete construction
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• 제2권1호
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• pp.29-37
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• 2014

Increasing emphasis on energy conservation and environmental protection has led to the investigation of the alternatives to customary building materials. Some of the significant goals behind understaking such investigations are to reduce the greenhouse gasemissions and minimize the energy required formaterial production.The usage of concrete around the world is second only to water. Ordinary Portland Cement (OPC) is conventionally used as the primary binder to produce concrete. The cement production is a significant industrial activity in terms of its volume and contribution to greenhouse gas emission. Globally, the production of cement contributes at least 5 to 7 % of $CO_2$. Another major problem of the environment is to dispose off the fly ash, a hazardous waste material, which is produced by thermal power plant by combustion of coal in power generation processes. The geopolymer concrete aims at utilizing the maximum amount of fly ash and reduce $CO_2$ emission in atmosphere by avoiding use of cement to making concrete. This paper reports an experimental work conducted to investigate the effect of curing conditions on the compressive strength of geopolymer concrete prepared by using fly ash as base material and combination of sodium hydroxide and sodium silicate as alkaline activator.

• 한국전기전자재료학회논문지
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• 제23권8호
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• pp.632-637
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• 2010

The measurement of contact wire wear in electric railways is one of the key test parameters to increase speed and maintain safety in electric railways. Wear caused by continuous interaction between pantographs and contact wires has a negative effect on current collection quality and severely damaged contact wires might cause hazardous accidents. This paper introduces a non-contact optical-based contact wire wear measuring system that will replace conventional wear detecting methods conducted by maintenance vehicles or workers. The system is implemented by high-speed cameras that can collect images of contact wires during vehicle operation, a laser used to create images profile of the contact wire surface, and a computer used to process the collected images. The proposed system is designed to assist maintenance of overhead contact lines by creating geometrically plotted images of contact wires to detect contact wire wear during operation on conventional lines or high-speed lines.

• 한국전기전자재료학회논문지
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• 제28권5호
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• pp.277-284
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• 2015

The humans are under attack involving the hazardous environment and pathogen/biotoxin aerosol that is realistic concerned. A portable, fast, reliable, and cheap Pathogen and Biotoxin Aerosol threat Detection(PBAD) trigger is an important technology for detect-to-protect and detect-to-treat system because the man-made biological terror is a fast and lethal infection. The ultraviolet C(UVC) wavelengths light source is key issue for PBAD that is sensitive because of strong fluorescence cross section from fluorescent amino acids in proteins such as tryptophan and tyrosine. The UVC-light emitting diode(LED) is emerging light source technology as alternative to laser or lamps as they offer several advantages. This paper discussed about the design consideration of UVC-LED for the PBAD system. The UVC-LED and PBAD technology, currently available or in development, are also discussed.

• 접착 및 계면
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• 제11권4호
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• pp.168-173
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• 2010

할로겐 함유 난연 화합물은 인체에 무해하고 유해가스 발생이 없는 환경 친화적인 소재로 대체되어가고 있다. 반도체 소자의 밀봉용 소재로 사용되는 에폭시 수지 조성물도 친환경적인 소재로 만들기 위해서, 에폭시 수지의 자소화에 관해 많은 연구가 이루어지고 있다. 본 연구에서도 신규 에폭시 수지(E3)를 사용하여 할로겐계 화합물을 전혀 함유하지 않는 자소성 에폭시 수지 조성물을 제조하였다. 새로 만들어진 에폭시 수지 조성물(EMC-1)은 UL 난연 V0를 갖고 5 wt% 분해 온도가 $451.9^{\circ}C$로, 할로겐계 난연제나 삼산화안티몬 등을 첨가하지 않고도 난연성이 우수하고 열분해성, 내열성 등이 우수하게 나타나 친환경 소재로 적용할 수 있다.

• 펄프종이기술
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• 제44권6호
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• pp.58-69
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• 2012

As the meaning of dictionary terminology, scum refers to a layer of impurities that accumulates at the surface of a liquid. In papermaking process, scum indicates the floated solid waste generated by a flotation process during the primary wastewater treatment. In this study, different kinds of stocks and scums collected from newspaper, liner, tissue and fine paper were analysed in details. The purpose of this study was firstly to demonstrate the composition characteristics of different sources of scum, secondly the analysis of environmental hazardous materials, and thirdly the evaluation of reutilization ability of fibrous materials from collected scum. As mentioned the meaning of solid waste, scum was actually differ from the waste sludge in sources, compositions and recycling abilities. In the same manner of waste paper, the sludge which is generated within onsite of papermaking processes would be reused as a raw material. The general compositions of scum from waste water were mainly inorganic ash materials, fine fibre fractions, recycled fibre debries, and ink particles. If the scum is able to reuse as fibrous additives in papermaking process, it could contribute to the savings of running costs in both the subsidiaries of fibrous material and the solid waste treatment with even small quantity.

• 한국기계가공학회지
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• 제18권12호
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• pp.1-6
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• 2019

Aluminum liners used in cylinders are hazardous for human health. In this study, we use a plastic PA liner inside cylinders to solve this problem. Plastic PA liners are widely used in the manufacturing industry in the production of food and beverage containers. We covered the aluminum boss with a plastic liner material and wound the composite fibers over the liner material. To reinforce the dome area, we used low strength / high elongation plastic liner. To predict the performance of the developed product, we conducted structural analyses utilizing the 3D laminated solid element. We verified the soundness of the product by testing the prototype.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권3호
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• pp.52-60
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• 2010

The stone-dust is an unavoidable by-product of aggregate production, which is produced about 0.8~1.0 million $m^3$ annually. The stone-dust is currently regarded as a hazard material on environment because it is classified as an industrial waste in the Waste Management Law of Korea. At present, the stone-dust is considered as a environmentally hazardous material, and is classified as an industrial waste according to the Waste Management Law of Korea. In this study, we assessed the heavy-metal contamination of the stone-dust on surrounding environments by various leaching tests. Leaching experiments (such as Korea Standard Leaching Procedure (KSLP), Soil Environment Preservation Act of Korea (SEPAK), Toxicity Characteristic Leaching Procedure (TCLP), and Synthetic Precipitation Leaching Procedure (SPLP)) show that very low heavy metals (As, Cd, Cu, Pb, Zn, Hg) and CN are leached out, or much less than each regulatory thresholds. The resuts of the leaching test with time in acidic solution (initial pH 5 and 3) indicate that pH-buffering minerals are present in the stone-dust. These results suggest that the stone-dust can not potentially affect adverse impact on surrounding environments such as surface water, groundwater and soil etc..