• Economic and Environmental Geology
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• v.36 no.1
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• pp.9-15
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• 2003

Two piston cores, obtained from the southwestern Ulleung Basin in East Sea, were analyzed to study the geochemical characteristics of the late Quaternary sediments and to detect any changes in sedimentary environment. The results show that the capacity of Total Organic Carbon is remarkably higher (average 1.8%) than that known from general open-sea. According to tephrochronology from known eruption ages, the sedimentation rates are high, ranging from 12.1 to 14.9 cm/kyr. The ratios of nitrogen and TOC (average 6.18-7.42) imply that the organic matter in the study area would be of oceanic origin. The correlation between sedimentation rates and sulfur contents suggests that the study area may be on the whole anoxic and somewhat high in primary productivity. During the Termination 1, inflows of organic matters were high. The sedimentary environments are characterized by rapid rates of sedimentation, and high anoxic values were compatible with accumulation of organic matters.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.1
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• pp.9-17
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• 2008

The presence of thiosulfate oxidizing bacteria was examined in rhizosphere soils of 19 economically important plant species belonging to 10 different families. The results showed that the thiosulfate oxidizing bacteria were present in all the tested rhizosphere soils, and the total 32 thiosulfate oxidizing bacteria were recovered. Furthermore, the biochemical characterization revealed that 56% and 44% of the isolates belonged to the obligate chemolithoautotrophs and facultative heterotrophs, respectively. The isolates ATSR15P utilized 19.17 mM of thiosulfate and accumulated 11.65 mM of sulfate in the medium. Concurrently, the decrease in pH of the medium was observed. This study comprehensively demonstrates that the active sulfur oxidation is a ubiquitous phenomenon in the rhizosphere of crop plants in Korea.

• Applied Chemistry for Engineering
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• v.23 no.3
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• pp.247-252
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• 2012

Of late, the development of advanced batteries with high power density and capacity has been indispensible for pushing ahead with much wider applications to electric vehicles and smart IT devices. However, a conventional Li-ion battery contains a limited energy density due to various technological challenges such that other types of Li batteries including Li-S and Li-air have been extensively studied due to their interestingly high energy capacities. Sulfur and oxygen, of which both are cathode materials, showing similar physicochemical characteristics have widely been available which may also contribute to the commercialization of these batteries. In this review, we introduce some perspectives in improving these advanced Li batteries through several approaches such as the provision of porous cathode structures, the optimization of cathode-electrolyte interfaces and the modification of Li anodes.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.2
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• pp.71-74
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• 2008

To investigate the sulfate utilization efficiency in different rape (Brassica napus) cultivars, sulfate uptake are analyzed under complete S-supply level (2.0mM ${SO_4}^{2-}$). This study used ten different genotypes of rape (Mokpo, Tamra, Youngsan, Naehan, Saturnin, Akela, Mosa, Capitol, Pollen and Colosse). For comparison of ${SO_4}^{2-}$ uptake among 10 cultivars, leaf number, leaf length and width, root length was also observed. Leaf length and width in all cultivars less variable among the cultivars examined. The longest root was shown in Saturnin (36.3 cm). ${SO_4}^{2-}$ uptake in Saturnin, Youngsan and Mokpo was significantly higher whereas that of Mosa and Pollen was relativety lower. Saturnin and Mokpo which have a high ${SO_4}^{2-}$ uptake exhibited a high ${NO_3}^-$ uptake.

• Journal of the Korean Chemical Society
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• v.25 no.1
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• pp.7-12
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• 1981

Solvolysis of $p-CH_3, p-H, p-Cl and p-NO_2$-benzenesulfonyl chlorides have heen studied in MeOH-MeCN mixtures. A nonlinear Hammett plot with a ratio order of p-NO_2 > p-CH_3 > p-H > p-Cl was obtained; the reaction was thought to proceed by an S_N1-S_N2 borderline mechanism. In all cases the reactivity was a maximum at 90∼95%(v) methanol, whereas methanol monomer selectivity defined as fi = \frac{k1}{ki}i (k1; observed pseudo-first order rate constant: ki; hypothetical rate constant for MeOH solution having the same polymer structure as in the pure MeOH) was a maximum at 80% methanol with a decreasing order of fi as p-NO_2 > p-Cl > p-H > p-CH_3.$ This was interpreted as the decrease in tightness of transition state; the larger the fi, the tighter is the MeOH attached to the substrate, and hence the more susceptible the substrate becomes to the approaching monomer methanol.

• Elastomers and Composites
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• v.33 no.5
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• pp.335-344
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• 1998

In this study, the tearing energy and the rate of crack propagation of natural rubber (NR) compounds were evaluated to improve the crack resistance of tank-track pads. Although the factors affecting the crack resistance properties of NR compounds are various in this experiment, the effects of filler(carbon black) and the crosslinking system were evaluated. When the amount of accelerator is equal to that of sulfur( eg. efficient vulcanization), the compound shows the most excellent in the aged mechanical properties and the crack resistance properties. The ISAF carbon black(CB) having a good reinforcing characteristics was better than any other CB grades in physical properties and processablity. The optimum content was 50phr.

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.845-851
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• 2008

Oxidative desulfurizaton of model sulfur compounds and Industrial diesel fuel(LCO; Light Cycle Oil) over Ti-grafted SBA-15 catalyst was studied in a batch reactor with tert-Butyl Hydroperoxide(TBHP) as oxidant. Effects of Ti loading, TBHP/Sulfur mole ratio, reaction temperature on ODS activity and kinetic parameters were investigated. Ti-grafted SBA-15 catalyst showed higher sulfur removal activity in the oxidative desulfurization reaction of refractory sulfur compounds(DBT and 4, 6-DMDBT) and LCO, suggesting that Ti-grafted SBA-15 catalyst could be a good candidate for ODS catalyst.

• Korean Journal of Agricultural Science
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• v.19 no.1
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• pp.33-39
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• 1992

Effects of buprofezin, a chitin synthesis inhibitor of insects, on mycelial growth, protoplast formation and reversion of Coriolus versicolor, Ganoderma applanatum and G. lucidum were investigated. The mycelial growth of C. versicolor, G, applanatum and G, lucidum was severely inhibited by buprofezin treatment, and the inhibition rate severely as the concentration of the buprofezin increased. Aerial mycelia and oidia formation of the mushrooms were increased by buprofezin treatment, but mycelial morphology was not changed. The rate of protoplast formation and reversion of G, applanatum was greatly increased by the treatment of the buprofezin, while that of G. lucidium was decreased. The rate of protoplast formation of C. versicolor was also increased when buprofezin was added to the medium, but the rate of protoplast reversion was not affected by the treatment, From the results obtained in this experiment, we found that the rate of protoplast. formation and reversion was increased by the treatment of the buprofezin in the mushrooms such as C, versicolor and G, applanatum, whose mycelial growth was fast on the medium, while that of G. lucidum, whose mycelial growth was relatively slow, was decreased by the treatment.

• Horticultural Science & Technology
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• v.29 no.1
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• pp.77-80
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• 2011

A new bi-color mini gerbera (Gerbera hybrida Hort.) 'Sun Cap' was developed from a cross of '99-ga-2' and '99-na-3-1' followed by seedling and line selections at the Flower Research Institute, Gyeongnam Agricultural Research and Extension Services (ARES) in 2007. Characteristic tests were conducted three times from 2004 to 2007. 'Sun Cap' has single type in good harmony with bi-color (Red/Yellow, RHS 45-B/9-A) ray floret and green center. It has good stable flower shape and strong peduncle. Its vase life was 13.5 days. The average yield of 'Sun Cap' was 102.6 flowers per plant a year in greenhouse. Yield trials were carried out from 2004 to 2007. This cultivar was registered for commercialization in 2009. 'Sun Cap' would be cultured under greenhouse condition in Korea.

• Journal of English Language & Literature
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• v.56 no.2
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• pp.187-217
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• 2010

By reading the main character, Rene Gallimard, in M. Butterfly as a spatial metaphor of America, this article examines how homogeneous American national identity of heterosexuality and white masculinity has been reinforced since the cold war and has constituted a crisis of hegemony with the decline of imperialism and how its pathological symptom is shown through the melancholic suicide of Gallimard. This article also argues how the feminine attributes implied in race, gender and sexuality in M. Butterfly are designated and allegorized as an impure, contaminated and ahistorical marker of national integrity in pthe social and material status of the heterosexual American white male. To develop my argument, I read M. Butterfly from a psychoanalytic point of view. Therefore I depend on Freud, Lacan, and Bhabha's psychoanalysis as the theoretical basis. In this paper, I also argue that the homogenized and fixed national identity is splitted and collapsed from within as shown in the Gallimard's melancholy and in the process of splitting the "Third Space" of hybrid subjects for the marginal and the emergent like Song Liling, a homosexual Asian man, can be built "from a space in-between." Therefore Hwang calls into questions conventions of fixed, essentialist identities through the shifting gender identities between Song and Gallimard in M. Butterfly and how identities in the plural are constructed variously in throughly historicized, politicized situations, and these constructions can be complicated by relations of power.