• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2002년도 총회 및 추계학술발표회
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• pp.12-12
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• 2002

• Korea-Australia Rheology Journal
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• 제17권1호
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• pp.21-25
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• 2005

Rheological properties and crystallization kinetics of the polypropylene (PP) block copolymer and recycled PP block copolymer were studied by advanced rheometric expansion system (ARES), differential scanning calorimetry (DSC), and optical microscopy. In the study of the dynamic rheology, it is observed that the storage modulus and loss modulus for the PP block copolymer and recycled PP block copolymer did not change with frequency. In the study of the effect of the repeated extrusion on the crystallization rate, half crystallization time of the PP samples was increased with the number of repeated extrusion in isothermal crystallization temperature ($T_c$). From the isothermal crystallization kinetics study, the crystallization rate was decreased with the increase of the number of repeated extrusion. Also, from the result of Avrami plot, the overall crystallization rate constant (K) was decreased with the increase of the number of the repeated extrusion. From the study of the optical microscopy, the size of the spherulite of the PP samples did not change significantly with the number of repeated extrusion. However, it was clearly observed that the number of the spherulite growth sites was decreased with the number of repeated extrusion. From the results of the crystallization rate, isothermal crystallization kinetics, Avrami plots, and optical microscopy, it is suggested that the crystallization rate of the PP block copolymer is decreased with the increase of the number of repeated extrusion.

• Elastomers and Composites
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• 제44권2호
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• pp.122-133
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• 2009

고무는 천연 고무를 비롯하여 부타디엔 고무, 스티렌-부타디엔 고무, 니트릴-부타디엔 고무, EPDM, 염소화 고무 등 산업적 요구에 따라 발전하여 왔다. 광범위한 분야에서 고무가 사용됨에 따라 새로운 물성을 갖는 합성 고무나 개질 고무의 생산이 필요하게 되었다. 본 리뷰 논문에서는 이중 결합을 포함하는 고무의 화학적 개질을 통하여 고무의 구조를 변화시키거나, 관능기, 이종 고분자 등을 도입하는 몇 가지 방법들에 대하여 정리해 보고자 한다. 특히, 최근에 많은 응용이 시도되고 있는 리빙 라디칼 중합법에 의한 고무의 개질을 소개하고 이의 효과를 알아보고자 한다.

• Korean Chemical Engineering Research
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• 제60권2호
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• pp.295-299
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• 2022

본 논문에서는 범퍼 스키드 플레이트 및 아웃사이드미러 하우징 부품에 적용되는 polypropylene (PP)와 acrylonitrile styrene acrylate (ASA) 소재를 활용하여 무도장 메탈릭 소재 구현에 대해 연구하였다. 금속 효과를 극대화하기 위해 알루미늄 입자의 종류, 크기, 함량을 최적화하였고 웰드 라인을 은폐하기 위해 종횡비가 상이한 하이브리드 알루미늄 입자를 사용하였다. 또한 부품 표면에 발생되는 플로우 마크를 개선하기 위해 유동성을 제어하였으며 사출 해석을 수행하였다.

• 대한화학회지
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• 제46권4호
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• pp.317-323
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• 2002

국내에서 유통되고 있는 LPG중의 잔류물질을 분석하였다. 시료 채취 장소는 LPG용기 재검사장의 용기 2곳, LPG집단공급시설 기화기 6곳 및 LPG충전소의 압축기 오일 1곳이었다. LPG용기재검사장의 용기내 잔류물질의 성분은 alkene, diene계통의 물질(탄산소$\leq$9), 방향족 탄화수소와 타르성 화학물질 (탄소수$\geq$10)으로서 각가 1.5∼39.9％, 0.7％, 57.8∼96.0％이었다. 반면에 LPG집단공급시설의 잔류물질 및 LPG 충전소 오일 중의 타르성 화학물질은 96.6％이상이었다. 채취한 9가지 시료는 3가지 군집으로 분류되었다. SE사 용기 재검사장 시료 (SE사 시료와 S사 LPG 용기 재검사장 시료와의 유클리디안 RMS 거리=2.11), S사 LPG용기재검사장 시료 (집단공급시설시료 군과의 유클리디안 RMS거리=0.110), 집단공급시설 시료군(유클리디안 RMS거리〈0.075)이다. LPG 집단공급시설 시료의 성분이 LPG충전소 압축기오일의 조성과 매우 유사하고, 충전소 오일의 밀도와 집단공급시설의 시료 밀도가 각각 0.873, 0.873 $\pm$0.00798 (99％ 신뢰구간)인 것으로 보아 타르성 화학물질은 LPG유통과정의 압축기 오일로부터 유입한 것으로 추정한다

• Nuclear Engineering and Technology
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• 제29권1호
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• pp.58-67
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• 1997

A numerical study has been peformed to investigate the flow and mixing characteristics of a chemical injection tank in the chemical and volume control system (CVCS) of Yonggwang 5&6 (YGN 5&6). This study was undertaken to provide a basis for modification of the previous design (YGN 3&4) which gave a lot of difficulties in installation and operation of the chemical injection system during the start-up test because it needs a special reciprocating pump with a high actual head. For the tank of length-to-diameter ratios (L/D) of 1,2 and 3, each with and without a baffle inside, calculation results were obtained by solving the unsteady laminar two-dimensional elliptic forms of governing equations for the mass, momentum and species concentration. Finite-difference method was used to obtain discretized equations, and the SIMPLER solution algorithm, which was developed based on the staggered grid control volume, was employed for the calculation procedure. Results showed that the baffle is very effective in enhancing the mixing in the tank and that a baffle should be installed near the tank entrance in order to 110 chemicals into the reactor coolant system (RCS) within the operating time required.

• 한국재난정보학회 논문집
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• 제11권4호
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• pp.515-519
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• 2015

'13년 87건, '14년 104건의 화학사고는 인명과 환경에 막대한 피해를 가져왔다. 또한 산업계는 피해처리와 복구에 많은 비용지출을 하였고 기업이미지에 큰 영향을 받았다. 대기 중으로의 빠른 확산과 독성을 갖는 화학사고는 근로자 뿐만 아니라 주변 거주 주민 등에도 위협적인 존재이다. 이러한, 화학사고의 원인을 철저히 분석하기 위해서는 체계적인 조사절차와 신뢰성 있는 결과가 도출되어야 한다. 본 연구를 통해 사고조사를 담당하는 각 기관의 제도를 비교 분석하여 화학사고 현장조사 체계마련 시 기본 자료로 활용이 가능할 것으로 판단된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.359-361
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• 2006

As circuits become increasingly complex and devices sizes shrinks, the demands placed on global planarization of higher level. Chemical Mechanical Polishing (CMP) is an indispensable manufacturing process used to achieve global planarity. In the CMP process, Diamond Disk (DD) plays an important role in the maintenance of removal rate. According to studies, the cause of removal rate decrease in the early or end stage of diamond disk lifetime comes from pad surface change. We also presented pad cutting rate (PCR) as a useful cutting ability index of DD and studied PCR trend about variable parameters that including size, hardness, shape of DD and RPM, pressure of conditioner It has been shown that PCR control ability of pressure and shape is superior to RPM and size. High pressure leads to a decrease of cell open ratio of pad surface because polyurethane of pad is destroyed by pressure. So low pressure high RPM condition is a proper removal rate sustain. By examining correlations between RPM and pressure of conditioner, it has been shown that PCR safe zoneto satisfy proper removal rate has the range 0.06mm/hr to 0.12mm/hr.

• 대한화학회지
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• 제57권2호
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• pp.272-278
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• 2013

Extract of ginger has been evaluated as a green inhibitor for the corrosion of steel in sulfide polluted NaCl solution using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. Potentiodynamic polarization measurements showed that this extract acts as a mixed type inhibitor but mainly inhibits the cathodic reaction. The inhibition efficiency was found to increase with inhibitor concentration reaching to approximately 83.9% using 250 ppm of ginger. Nyquist plots show a single capacitive loop in uninhibited and inhibited solutions. From EFM the causality factors are very close to theoretical values which indicate that the measured data are of good quality. The adsorption process of the studied extract on steel surface obeys Temkin adsorption isotherm. The results obtained from the different electrochemical techniques were in good agreement which prove the validity of these tools in measurement of corrosion rate. Ginger extract has no effect on Escherichia Coli and can be applied safely on waste water treatment plants.

• Safety and Health at Work
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• 제12권3호
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• pp.403-415
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• 2021

Background: This study aimed to assess the possibility of benzene exposure in workers of a Korean semiconductor manufacturing company by reviewing the issued patents. Methods: A systematic patent search was conducted with the Google "Advanced Patent Search" engine using the keywords "semiconductor" and "benzene" combined with all of the words accessed on January 24, 2016. Results: As a result of the search, we reviewed 75 patent documents filed by a Korean semiconductor manufacturing company from 1994 to 2010. From 22 patents, we found that benzene could have been used as one of the carbon sources in chemical vapor deposition for capacitor; as diamond-like carbon for solar cell, graphene formation, or etching for transition metal thin film; and as a solvent for dielectric film, silicon oxide layer, nanomaterials, photoresist, rise for immersion lithography, electrophotography, and quantum dot ink. Conclusion: Considering the date of patent filing, it is possible that workers in the chemical vapor deposition, immersion lithography, and graphene formation processes could be exposed to benzene from 1996 to 2010.