• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.316-318
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• 2005

PU midsole세척용 수성세정제로서 Ester구조를 가진 비이온성 계면활성제를 사용하여 limonene을 유화분산하고, 첨가제의 영향을 검토하여 세정효과를 측정한 결과 계면활성제의 사용은 1${\sim}$1.5wt%, limonene은 30wt%의 범위에서 emulsion입경이 최소로서 가장 좋았다. 접착증진제(CR)와 세척향상제(LD)를 합성하고 첨가효과를 검토한 결과 일정 첨가량 이하에서 세정력이 증가하였으며, 두 첨가제를 동시에 적용하여 synergy효과를 확인하였다. 초적의 첨가조건은 CR과 LD를 각각 5wt%와 2wt% 동시 첨가하는 경우로서 세정성능이 40%정도 증가하였다.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.383-384
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• 2010

This study was investigated freezing temperature measurement method and freezing temperature properties of anti-freeze agency in the domestic. Anti-freeze agency kinds were intended for nitrous acid. Anti-freeze agency with water dilution ratio was showed range of $-4.9{\sim}-6.3^{\circ}C$ in case of 1:3, $-3.3{\sim}-4.2^{\circ}C$ in case of 1:5, $-2.1{\sim}-3.3^{\circ}C$ in case of 1:7.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1296-1300
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• 2009

삽교호는 금강 하류부에서 해수의 역류에 의한 염수 침입에 따른 염해방지와 유역에 필요한 담수를 확보하기 위하여 만들어졌다. 방조제는 조위 상승에 따른 해수의 침임을 방 할 뿐만 아니라 홍수 시에는 배수갑문의 인위적인 조작을 통해서 과다한 홍수량을 바다로 배제하여 상류유역의 홍수피해를 방지하고 있다. 방조제로 인하여 기존에 염해로 인하여 취수할 수 없던 하천구간에서의 취수가 가능하게 되었으며, 일정한 수위로 관리되도록 함으로써 상당량의 농업용수를 확보하게 되었으나, 댐과는 달리 허가를 위해 가용한 유량이 얼마인지 판단을 해본 적이 없다. 그것은 방조제의 방류량이 댐의 방류량과는 달라서 조석의 영향을 매우 크게 받기 때문에 단순한 물수지 분석 등으로 이를 모의하기가 힘들기 때문이다. 게다가 1일 2회의 조석이 발생하므로 1일단위의 물수지 분석은 어려운 현실이다. 방조제의 공급능력을 고려하지 않고 물수지 분석을 하게 되면, 취수하고 있는 용수는 추가적으로 확보되는 물을 사용하는 것이 아니라 자연하천에서의 물을 사용하는 것으로 분석된다. 이러한 문제점을 극복하기 위해서는 방조제가 공급 가능한 가용허가수량이 얼마인지 분석하고 이를 물수지 분석에 반영해 줄 수 있도록 해야 할것이다. 이에 본 연구에서는 조위예측방법 및 수문조작 방법등 주요 모의 알고리즘을 이용하여 물수지 분석 모형을 개발하고 수자원장기종합계획의 일별자연유출량 자료에 대해 물수지 분석을 수행함으로써 삽교천방조제의 수리권 가용수량에 대해 추정하여 보았다. 적용 결과 삽교천방조제에 의해 기존의 갈수량인 $4.9m^3$/초 외에 안정성이 요구되는 생 공용수로 약 $4.2m^3$/초의 유량과, 제한적인 시기만 사용하는 농업전용으로 약 $10.3m^3$/초의 유량이 공급 가능할 것으로 나타났다.

• Elastomers and Composites
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• v.40 no.2
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• pp.93-103
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• 2005

In this study, surface treatment of the elastomeric matrix was investigated to develop a substituting material for steel dynamic damper of automobile. The key technology is to get ultra high density elastomeric compound in order to substitute steel dynamic damper. The optimum matrix material(chloroprene rubber) and filler(metal powder) were selected for this. The several properties of elastomeric compound were examined. According to the results, the $t_{s2}$ of filled elastomeric compound was decreased with increasing the filler loading whereas the $t_{90}$ was increased. Also, tensile strength and rebound resilience were decreased with filler loading. To solve the problem of high filler loading, the photo grafting technique was employed on elastomeric matrix. The degree of grafting was determined by FTIR-ATR. Also, the filler surface was modified by chemical etching and the surface morphology was examine by SEM. After chemical treatment of filler, the particle size analyzer was used to examined the particle size, size distribution, and morphology of the modified filler.

• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.334-338
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• 2007

The disinfection effects of trichloroisocyanuric acid (TICA), calcium hypochlorite (CH), and Bromochlorodimethylhydantoin (BCDMH) on various bacteria in aqueous suspension were comparatively characterized at various concentrations and exposure times of each disinfectant. When various bacteria cells ($10^8\;CFU/ml$) including Escherichia coli, Pseudomonas aeroginosa, Enterococcus faecalis, Bacillus cereus, Legionella pneumophila, and Staphylococcus aureus were exposed with a solution containing 8 ppm each of TICA, a 99% of the initial cells were killed in 60 sec, 368 sec, 372 sec, 506 sec, 812 sec, and 909 sec, respectively. In addition, the minimum exposure time required to kill 99% of E. coli ($10^8\;CFU/ml$) with 8 ppm of each TICA, BCDMH and CH was measured at 60 sec, 114 sec, and 7,100 sec, respectively. These comparative studies demonstrate that disinfection efficacy is highly variable depending on microbial species as well as disinfectant type, concentration, and exposure time.

• Analytical Science and Technology
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• v.6 no.2
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• pp.167-180
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• 1993

The effects of coating variables on the formation of aluminide coating layer with good oxidation resistance on the strongest hot-forged superalloy in the world, KM 1557 developed at KIST by pack cementation process were studied. Pack aluminizing were performed by high-activity process with pure aluminium powders and by low-activity process with codep powders. For high-activity process, Al deposition rate, growth rate of coating layer, and cross-sectional microstructures were influenced by the species and additive amounts of activators and the additive amounts of pure aluminium powders. For low-activity process, Al deposition rate, growth rate of coating layer, and the cross-sectional microstructures were not influenced by the species but additive amounts of activators. Surface structures of coating layer were influenced by the species of activators. Regardless of aluminium activity, Al deposition rate was proportional to the square root of time and parabolic rate constants were different with the species of activators. The activation energy for deposition of aluminium was different with the species of activators for high-activity process. Regardless of the species of activators, the activation energy for deposition of aluminium was 12~14 Kcal/mole for low-activity process.

• KSBB Journal
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• v.17 no.3
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• pp.314-316
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• 2002

The disinfection effects of trichloroisocyanuric acid (TICA) and calcium hypochlorite on E. coli in aqueous suspension were comparatively characterized at various concentrations and exposure times of each disinfectant. When the E. coli ($10^{7}$ CFU/mL) cells were exposed with a solution containing 12 ppm each of TICA and calcium hypochlorite, a 90% of the initial cells were killed in 4 sec and 390 sec, respectively. In addition, calcium hypochlorite lost its disinfection effect in about 1 hr exposure under the sun light, whereas TICA maintained its disinfection effect up to 6 hrs under the same condition. These comparative studies demonstrate that TICA is a more effective and stable disinfectant than calcium hypochlorite to sterilize E. coli in aqueous suspension.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.8
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• pp.718-725
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• 2012

Fuel or oil which is leaked into the aircraft engine bay can make a fire when it is contacted to the engine surface of hot temperature. In order to avoid fire, the fire extinguish system should be designed so that the extinguishing agent is quickly injected and its concentration keeps higher in the fire protection region. FAA requires that the extinguishing agent injected within the fire protection region should be sustained longer than 0.5 second on keeping a higher concentration than 6%. For developing a fire protection system satisfying the FAA regulation, numerical and experimental studies for the injection time and the concentration of the extinguishing agent were conducted. These results showed similar trend for the injection time or concentration, but the data acquisition was delayed due to the response of the sensors in the experiment.

• Journal of the Korea Concrete Institute
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• v.17 no.6 s.90
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• pp.879-884
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• 2005

The setting time is a very important factor affecting the quality of tunnel lining and reinforcement of inclined slope etc. Currently, however, the quality criteria of accelerating admixture to improve it is not established well. In this study, evaluation on setting time measuring methods of cement mixed a accelerating admixture (AA) was performed using Gillmore and Vicat needle test methods. For both test methods, the setting time for addition at a time was better than post addition regardless of initial setting and final setting. For Gillmore needle test method, two types of measuring methods were selected and it is noted that setting time with cement type under the same accelerating admixture can be different. Accordingly, manufacturing company shall develop a less sensitive accelerating admixture to cement type. For Vicat needle test method, six types of measuring methods were used and a proper measuring method of the admixture were proposed as follows: (1) the temperature of materials used shall be controlled exactly and (2) to evaluate its properties, an admixture usage of $5\%$ (ratio of cement weight) is recommended.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.3 no.6
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• pp.34-44
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• 1982

1970년대 초부터 본격적으로 도입되기 시작하여 1974년 이래 급속한 사용증가를 기록한 우리나라의 벼농사용 제초제는 1980년을 최고로 95$\%$ 이상의 농가에 의해 매년 사용되고 있다. 1982년 5월 현재 정부에 의해 논잡초약으로 고시된 제초제의 종류는 14종 17게 품목이고 이들중 8종 10개 품목은 일년생 잡초약 그리고 6종 7개품목은 소위 다년생 잡초약으로 분류되고 있다. 그동안 벼의 소출에 직접 영향을 주는 살충제나 살균제의 중요성에 비추어 제초제는 상대적으로 그 중요성이 비교적 경시(輕視)되어 온 것이 사실이다. 그러나 1980년 이후 일반농가는 물론 정부의 제초제에 대한 관심이 두드러지게 높아져서 여러 가지 논의가 되고 다각도에서 심각한 검토가 이루어지고 있는 것이 현실이다. 이 기회에 필자가 평소에 생각해온 문제의 핵심과 그 대책을 기술함으로써 효과적인 잡초방제에 일조(一助)가 되기를 바란다.