• 한국건설순환자원학회논문집
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• 제6권2호
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• pp.81-88
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• 2011

폐유황으로부터 제조한 개질유황재료를 시멘트 대체 혼화재로 활용 가능성 여부를 알아보기 위한 연구의 일환으로 개질유황의 품질특성 및 혼화재료로 사용한 모르타르의 기초적 특성에 대하여 분석 및 검토한 결과 개질유황을 혼합한 모르타르의 유동성은 혼합률이 증가함에 따라 감소하였으며, 압축강도는 저하되었다. 또한, 개질유황을 15% 이내로 혼합한 모르타르의 휨, 인장 및 접착강도는 개선되었으며, 수축량은 증가하였다. 특히 내화학성은 혼합률이 증가함에 따라 우수한 저항성능이 나타났다. 따라서 본 연구에서는 개질유황을 시멘트 대체 혼화재로 활용 가능함을 확인할 수 있었다.

• Toxicological Research
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• 제35권4호
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• pp.303-310
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• 2019

We are exposed to numerous xenobiotic electrophiles on a daily basis through the environment, lifestyle, and dietary habits. Although such reactive species have been associated with detrimental effects, recent accumulated evidence indicates that xenobiotic electrophiles appear to act as signaling molecules. In this review, we introduce our findings on 1) activation of various redox signaling pathways involved in cell proliferation, detoxification/excretion of electrophiles, quality control of cellular proteins, and cell survival during exposure to xenobiotic electrophiles at low concentrations through covalent modification of thiol groups in sensor proteins, and 2) negative regulation of reactive sulfur species (RSS) in the modulation of redox signaling and toxicity caused by xenobiotic electrophiles.

• Elastomers and Composites
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• 제34권4호
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• pp.299-314
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• 1999

Bonding metal and textile components to rubber has always posed a problem. In this paper, an attempt had been made to modify textile and metal surfaces for bonding with rubber. The metal surfaces were modified using silane coupling agents and textile fibers were modified using plasma polymerization techniques. Some results on adhesion of metals to a range of sulfur-cured rubber compounds using a combination of organofunctional silanes are given here. The treatment was not only effective for high-sulfur compounds but also for low-sulfur com pounds as used in engine mounts and even for some semi-EV compounds. Coatings of plasmapolymerized pyrrole or acetylene were deposited on aramid and polyester tire cords. Standard pull-out force adhesion measurements were used to determine adhesion of tire cords to rubber compounds. The plasma coatings were characterized by various techniques and the performance results are explained in an interpenetrating network model.

• Journal of Microbiology and Biotechnology
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• 제20권8호
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• pp.1196-1203
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• 2010

In the present work, methanethiol and dimethyldisulfide were investigated as sulfur sources for methionine synthesis in Corynebacterium glutamicum. In silico pathway analysis predicted a high methionine yield for these reduced compounds, provided that they could be utilized. Wild-type cells were able to grow on both methanethiol and dimethyldisulfide as sole sulfur sources. Isotope labeling studies with mutant strains, exhibiting targeted modification of methionine biosynthesis, gave detailed insight into the underlying pathways involved in the assimilation of methanethiol and dimethyldisulfide. Both sulfur compounds are incorporated as an entire molecule, adding the terminal S-$CH_3$ group to O-acetylhomoserine. In this reaction, methionine is directly formed. MetY (O-acetylhomoserine sulfhydrylase) was identified as the enzyme catalyzing the reaction. The deletion of metY resulted in methionine auxotrophic strains grown on methanethiol or dimethyldisulfide as sole sulfur sources. Plasmid-based overexpression of metY in the ${\Delta}$metY background restored the capacity to grow on methanethiol or dimethyldisulfide as sole sulfur sources. In vitro studies with the C. glutamicum wild type revealed a relatively low activity of MetY for methanethiol (63 mU/mg) and dimethyldisulfide (61 mU/mg). Overexpression of metY increased the in vitro activity to 1,780 mU/mg and was beneficial for methionine production, since the intracellular methionine pool was increased 2-fold in the engineered strain. This positive effect was limited by a depletion of the metY substrate O-acetylhomoserine, suggesting a need for further metabolic engineering targets towards competitive production strains.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.99.1-99.1
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• 2010

Many efforts on the surface sulfurization of $Cu(InGa)Se_2$ (CIGS)thin films have been reported as techniques to improve CIGS solar cell performance. We have investigated the sulfurization technique using the sulfur vapor. The co-evaporated $Cu(In,Ga)Se_2$ tin film was used for sulfurization. A thin $Cu(In,Ga)(S,Se)_2$ layer was grown on the surface of the CIGS thin film after high-temperature annealing in sulfur vapor. The structural and compositional properties of the thin films were studied by XRD, EDS and AES analysis. The obtained results revealed that the surface modification technique is promising method to S incorporated into CIGS absorber.

• Nuclear Engineering and Technology
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• 제52권2호
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• pp.373-380
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• 2020

This study was carried out to convert the hydrophobic characteristics of PVDF to hydrophilic. Poly(-vinylidene fluorine) (PVDF) was grafted by electron beam irradiation and sulfonated. The grafting degree of modified PVDF increased with the monomer concentration, but not the conversion degree. From the results of FTIR and XPS, it was shown that the amount of converted sulfur increased with the grafting degree. The radiation-induced graft polymerization led to decrease fluorine from 35.7% to 21.3%. Meanwhile, the oxygen and sulfur content increased up to 8.1% and 3.2%. The pore size of modified membranes was shrunken and the roughness sharply decreased after irradiation. The ion exchange capacity and contact angle were investigated to show the characteristics of PVDF. The enhanced ion exchange capacity and lower contact angle of modified PVDF showed that the hydrophilicity played a role in determining membrane fouling. Electron beam irradiation successfully modified the hydrophobic characteristics of PVDF to hydrophilic.

• 자원리싸이클링
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• 제12권2호
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• pp.28-35
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• 2003

폐타이어의 처리방법으로서는 recycling이 가장 최선의 방법 중의 하나이다. 하지만 재활용의 어려움 중에는 경제성의 문제가 있다. 이러한 문제점을 해결하기 위해서는 폐타이어의 입자 크기를 줄이는 방법과 표면처리를 통하여 제품의 물성을 향상시키는 방법이 있다. 본 연구에서는 두 방법을 동시에 응용한 방법으로 폐타이어의 입자크기를 작게 하고 ultrasonic 처리를 하였다. 그 결과로 폐타이어 가황 시스템의 변화를 가져옴으로서 물성의 향상을 알 수 있었다. 이러한 기술은 재활용의 경제성을 높이는 기초기술임을 알 수 있었다.

• Elastomers and Composites
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• 제34권3호
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• pp.229-238
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• 1999

본 연구에서는 제3의 성분으로 벤젠 술폰산계열 반응성 화합물과 ENB 및 DCPD를 사용하여 비diene계 고분자인 EVA를 특수 화학적 처리에 의하여 EVA의 주쇄에 불포화기 즉, 이중결합을 도입시켰다. 또한 이중결합도입 EVA와 diene계 범용합성고무인 CR, SBR과의 블렌드를 통하여 황가 황체를 제조하여 가황체들의 물리적 특성을 비교 검토하였다. 검토결과 원래의 EVA가 갖고 있는 green strength, 사출 압출 성형성, 접착성, 점착성, 치수안정성, 오존저항성 등의 장점은 그대로 살리면서도 황가황이 가능하여 열가소성의 EVA가 갖는 사용온도의 한계 문제와 기계적 특성 즉, 경도, 인장강도, 인장 응력, 신장율 등온 향상시켰다. 비diene계 고분자와 diene계 고분자의 블렌드에 있어서 개질에 대한 연구가 더 수행되어진다면 합성고무에서 나타나는 부족한 가공성, 내산화 안정성, 접착성 등을 크게 향상시킬 수 있을 것이며 아울러 EVA의 융해유동성을 이용한 고무제품 가공공정의 연속화가 가능하게 될 것이다.

• 동아시아식생활학회지
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• 제6권2호
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• pp.213-219
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• 1996

Addition of reducing agents during extrusion markedly affected physical and chemical properties of wheat flour and gluten extrudates. Expansion at the die was increased for wheat flour and gluten extrudates. Organic materials containing sulfur were evaporated as a flavor from gluten at the die and total sulfur contents were decreased. Physical shape was different for gluten extrudates without reducing agents. It was difficult to form the long strand of gluten extrudate without cooling die. Hydroquinone accelerated cell breakdown and produced more irregular shape of extrudate. However, addition of cysteine decreased the cell breakdown and produced the long strand of gluten extrudates. Chemical reactions of reducing agents such as cysteine and hydroquinone were different for high content (＜80%) of wheat gluten. It was assumed that reducing agents donated hydrogen to inhibit the formation of disulfide crosslinking, decreased the dough strength and produced the broken cell and irregular shape of extrudates. Whereas, cysteine reacted as a binder as well as reducing agent and formed long strands. The evidence of reaction of reducing agents was shown from the fact that non-protein disulfide was increased and protein disulfide was slightly decreased from cysteine added gluten extrudate.

• 한국자동차공학회논문집
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• 제15권6호
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• pp.17-22
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• 2007

GTL(Gas-to-Liquids) fuel technology was converted from the natural gas, coal and biomass into the diesel or kerosene by Fisher-Tropsch synthesis. GTL fuel have very good merits on high cetane number, low density, free sulfur, lower aromatics contents and no poly-aromatic hydrocarbons as well as the autoignition characteristics. These physical properties make it valuable as a diesel fuel with lower emissions than the conventional diesel fuel. Furthermore, GTL fuel can be use not to the engine any modification. Therefore, to evaluate emissions of GTL fuel, the tested diesel vehicles were fueled on blends of GTL fuel/ultra low sulfur diesel fuel(ULSD). And then, we found out that GTL fuel reduced regulated emissions(CO, NOx, HC, PM) compare with conventional diesel fuel.