• 한국자기학회:학술대회 개요집
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• 한국자기학회 2014년도 임시총회 및 하계학술연구발표회
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• pp.148-148
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• 2014

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3209-3212
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• 2014

This paper describes a selective synthetic method of fabricating Ag nanowires by using a modified polyol process. To synthesize the Ag nanowire, an ethylene glycolic solution of silver nitrate and an ethylene glycolic solution of polyvinylpyrrolidone solution containing a small amount of organic oxidant, 1,4-benzoquinone, were slowly added to a hot ethylene glycol medium at $160^{\circ}C$ for 8 min using a syringe pump. The reaction mixtures were heated for an additional 45 min and cooled to room temperature. Finally, the silver nanomaterials were isolated from the mixture by centrifugation. The crystal structure of the nanomaterials was investigated by powder X-ray diffraction analyses, and their morphology was investigated by scanning electron microscopy. A small amount of organic oxidant, 1,4-benzoquinone, played a significant role in controlling the morphology during crystal growth. Consequently, Ag nanowires rather than Ag nanoparticles were selectively obtained.

• 전기화학회지
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• 제15권4호
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• pp.264-269
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• 2012

본 연구에서는 50 wt%에 달하는 매우 높은 Pt 담지량에서도 장기내구성이 우수한 연료전지용 Pt/MWCNT 촉매를 마이크로파를 이용한 폴리올법을 이용하여 제조하였다. X선 회절분석법과 투과전자현미경 분석결과 마이크로파 조사시간이 늘어남에 따라 Pt의 크기가 증가하였다. 마이크로파 조사시간이 10분, 20분, 30분일 경우 Pt 크기는 각각 4.1, 4.9, 8.5 nm로 나타났다. 마이크로파를 사용하지 않은 기존 폴리올 방법에 의해 제조된 촉매와 비교하였을 경우 Pt 분산도와 장기내구성이 증가한 것으로 나타났다.

• 한국응용과학기술학회지
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• 제18권2호
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• pp.103-110
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• 2001

Resource recovery and recycling of materials and products, including polyurethanes is viewed as a necessity in today's society. Most urethane polymers are made from a polyol and a diisocyanate. these and be chemicals such as water, diamines or diols that react with isocyanate groups and add to the polymer backbone. The problems of recycling polyurethane wastes has major technological, economic and ecological significance because polyurethane itself is relatively expensive and its disposal whether by burning is also costly. In general, the recycling methods for polyurethane could be classified as mechanical, chemical and feedstock. In the chemical recycling method, there are hydrolysis, glycolysis, pyrolysis and aminolysis. This study, the work was carried out glycolysis using sonication ant catalyzed reaction. Different kinds of recycled polyols were produced by current method(glycolysis), catalyzed reaction and sonication as decomposers and the chemical properties were analyzed. The reaction results in the formation of polyester urethane diols, the OH value which is determined by the quantity of diol used for the glycolysis conditions. The glycolysis rates by sonication for the various glycols, increased as fallows: PPG

• 한국안전학회지
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• 제17권1호
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• pp.68-71
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• 2002

A research on accident loss calculation for polyol process without safety management activities, and safety cost estimation using process risk assessment has been implemented. In order to estimate a magnitude of loss, accident scenarios were made by combining result made from HAZOP Study method with accident possibility analysis results implemented with FTA. Also effect assessment was implement for accident consequence of each scenario. And minimum possible loss cost has been calculated when safety investment do or not. Result from cost-benefit analysis was shown as approximately \335 billion(=USS44,000 billion), as cost after subtracting safety management cost from minimum possible loss cost.

• KSBB Journal
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• 제20권2호
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• pp.84-87
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• 2005

바이오디젤과 바이오디젤을 기반으로 생산된 neopentyl polyol ester (NPE)계 윤활유 베이스, 디젤유 윤활유와 석유디젤을 분석대상으로 하여 지렁이 (Eisenia fetida)를 이용한 독성 시험을 수행하였다. OECD 207규격에 근거하여 독성을 분석한 결과 바이오디젤과 NPE계 윤활유 베이스의 반수치사농도 $(LC_{50})$ 값은 각각 2,450과 1,528 mg/kg dry weight of soil로서 두 물질은 독성 이 적은 경독성 (slightly toxic) 물질인 것으로 판명되었다. 디젤유 윤활유와 석유디젤의 경우 반수치사농도 $(LC_{50})$ 값이 각각 500과 603 mg/kg로서 중등독성 (moderately toxic) 물질로 판정되었다.

• KSBB Journal
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• 제20권1호
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• pp.55-59
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• 2005

바이오디젤과 바이오디젤을 기반으로 생산된 neopentyl polyol ester (NPE)계 윤활유 베이스, 디젤유 윤활유와 석유디젤을 분석대상으로 하여 독성을 평가하였다 조류를 이용하여 수용액 상에서 화학물질의 독성시험을 조사하는 OECD 201에 근거하여 Chlorella vulgaris를 96시간 동안 배양하면서 독성시험 분석한 결과, 바이오디젤과 NPE계 윤활유 베이스의 반수저해농도 $(EC_{50})$ 값은 각각 84와 69mg/L로서 두 물질이 독성 이 적은 경독성 (slightly toxic)물질인 것으로 판명되었다. 디젤유 윤활유와 석유디젤의 경우 반수저해농도 $(EC_{50})$ 값이 각각 42와 24 mg/L로서 중등독성 (moderately toxic) 물질로 판정 되었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.84.1-84.1
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• 2010

Since the discovery of the carbon nanotube(CNTs), they have attracted much attention because of unique properties that may impact many fields of science and technology. The considerable properties of CNTs include high surface area, outstanding thermal, electrical conductivity and mechanical stability. However, uniform deposition of Pt nanoparticles on carbon surface remains inaccessible territory because of the inert carbon surface. In this study, we prepared directly oriented CNTs on carbon paper as a catalyst support in cathode electrode. carbon surface was functionalized using aryl diazonium salt for increasing adhesion of Ni particles which is precursor for growing CNTs. For fabricate electrode, CNTs on carbon paper were grown by chemical vapor deposition using Ni catalyst and Pt nanoparticles were deposited on CNTs oriented carbon paper by polyol method. The performance was measured using Proton electrolyte Membrane Fuel Cell(PEMFC). The structure and morphology of the Pt nanoparticles on CNTs were characterized by Scanning electron Microscopy(SEM) and Transmission electron Microscopy (TEM). The average diameter of Pt nanoparticles was 3nm.

• Korea-Australia Rheology Journal
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• 제16권1호
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• pp.47-54
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• 2004

Low Reynolds number, dilute, and surfactant-free bubble suspensions are prepared by mechanical mixing after introducing carbon dioxide bubbles into a Newtonian liquid, polyol. The apparent shear viscosity is measured with a wide-gap parallel plate rheometer by imposing a simple shear flow of capillary numbers(Ca) of the order of $10^{-2}$ ~ $10^{-1}$ and for various gas volume fractions ($\phi$). Effects of capillary numbers and gas volume fractions on the viscosity of polyol foam are investigated. At high capillary number, viscosity of the suspension increases as the gas volume fraction increases, while at low capillary number, the viscosity decreases as the gas volume fraction increases. An empirical constitutive equation that is similar to the Frankel and Acrivos equation is proposed by fitting experimental data. A numerical simulation for deformation of a single bubble suspended in a Newtonian fluid is conducted by using a newly developed two-dimensional numerical code using a finite volume method (FVM). Although the bubble is treated by a circular cylinder in the two dimensional analysis, numerical results are in good agreement with experimental results.

• 한국수소및신에너지학회논문집
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• 제26권3호
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• pp.227-233
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• 2015

In this study, we evaluate catalytic activity of Pd/C catalyst that is synthesized by modified polyol method. With such formed Pd/C is used as anodic catalyst for direct formic acid fuel cell (DFAFC) and performances of the DFAFC are measured to verify whether the new catalyst is effective for enhancing DFAFC performance and to determine optimal loadings of the Pd/C needed for obtaining best DFAFC performance. Pd particle distribution of the Pd/C catalyst is analyzed by TEM, while its catalytic activity is estimated by using cyclic voltammogram (CV) as measuring formic acid oxidation reaction and active surface area. As a result of that, the Pd/C catalyst synthesized by modified polyol shows better catalytic activity and DFAFC performance with small loading amount of Pd/C. When loading amount of Pd/C is $1.5mgcm^{-2}$, maximum power density of DFAFC adopting the catalyst is $122mWcm^{-2}$.