• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.2
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• pp.81-88
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• 2011

This study ascertained the possibility of use of sulfur abstracted from waste sulfur as a construction material through modification process and manufacturing high efficiency modification sulfur with superior quality on dispersibility and hydrophilic in normal temperature. Mechanic, behavior and chemical durability of mortar with added modification sulfur. The results of the study are as follows. The fluidity of mortar mixed with modification sulfur and compressive strength decreased as ratio of mixing of them increases. Flexural, tensile and bond strength of the mortar are also improved and shrinkage of it increases. Especially chemical durability of the mortar showed excellent resistance with the increase of ratio of mixing. Therefore this research has confirmed the modification sulfur can be used as a addmixture for cement.

• Toxicological Research
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• v.35 no.4
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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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• v.34 no.4
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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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• v.20 no.8
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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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• 2010.06a
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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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• v.52 no.2
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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.

• Resources Recycling
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• v.12 no.2
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• pp.28-35
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• 2003

The powder utilization is the one of the best recycling methods for the waste tires. However, economic problem still exist. In order to overcome an economic problem the ground rubber particles are surface modified, which induced to the rubber particles that have good mechanical properties and higher compatibility. In this study, we investigated ultrasonic treatment and reduced rubber particle size. Results showed that sulfur cross-linkage network of the waste rubber is changed by the ultrasonic treatment.

• Elastomers and Composites
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• v.34 no.3
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• pp.229-238
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• 1999

In this study, double bond, unsaturated group was introduced to the main chain of EVA by chemically treating EVA, nondiene polymer. Benzene sulfonic acid, ENB and DCPD were used as a third element. Also, from blending CR and SBR, conventional synthetic rubber we prepared vulcanizates and examined their physical properties. The datum lead to the following conclusion that some problems were modified; limited temperature in use and mechanical properties like hardness, tensile strength, tensile stress, and elongation rate of thermoplastic EVA, keeping the following advantages of original EVA; green strength, injection molding by Pressure, adhesion, tackiness, dimensional stability, and ozone resistance, etc. It is expected that continuous research of the modification between nondiene and diene polymer will improve what were shown disadvantages in synthetic polymer; processing, oxidation resistance, and adhesion. In addition, it will be possible to continue process of rubber products by utilizing possible fluidity for fusion of EVA.

• Journal of the East Asian Society of Dietary Life
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• v.6 no.2
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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.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.6
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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.