• Journal of the Korean earth science society
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• v.23 no.5
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• pp.416-423
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• 2002

The concentrations of dimethylsulfide (DMS) and carbon disulfide (CS$_2$) were measured concurrently with relevant environmental parameters at Kosan, Cheju during Apr 2001. Results of our analysis indicate that the combined temporal variations of both DMS and CS$_2$ record three distinctible patterns that are separable from each other. For instance, DMS behaved very similarly to CS$_2$ during the 1st (5${\sim}$18 Apr) and 3rd period (23${\sim}$26 Apr). The pronouncingly high concentration of CS$_2$ was maintained during the first period, but DMS values peaked mostly during the third period. It was furthermore striking to find that changes in DMS levels occurred in an opposite direction relative to CS$_2$ during the 2nd period. Although most of these variabilities appear to be associated with the interaction of source/sink processes and the air parcel movement, certain aspects of their behavior are found to be highly complicated enough to account for.

• Bulletin of the Korean Chemical Society
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• v.23 no.4
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• pp.567-570
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• 2002

Diazotization of 3-amino-2-ethoxycarbonylthieno[2,3-b]quinoxaline 1 gave the diazonium salt 2 which was reacted with SO2 and N-methylaniline to give sulfamoylquinoxaline derivatives 3-5. Imidazothienoquinoxaline 8 was obtained from the reaction of carboxylic acid hydrazide 6 with nitrous acid and followed by boilling the carboazide 7 in dry xylene. Also, compound 6 react with CH(OEt)3 to give aminopyrimidine 9 which was reacted with arylidene malonodinitrile, furfural and/or dimethoxy-tetrahydrofuran to afford compounds 10, 11 and/or 12 respectively. Refluxing of 6 with CS2 gave oxadiazolylthienoquinoxaline 13, reaction of 13 with hyrazine hydrate, CH(OEt)3, nitrous acid, CS2 and a-halocompounds to give 14-19.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.5
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• pp.515-524
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• 2005

In this study, the concentrations of major reduced sulfur compounds (RSC: $H_{2}S,\;CH_{3}SH$, DMS, $CS_2$ and DMDS) were determined from various emission sources of individual companies located within the Ban Wal industrial complex of Ansan city, Korea. We investigated the emission concentration levels of RSC from a total of 47 individual companies during June 2004 to January 2005. The results of our study indicate that the emission concentration levels of RSC vary in a highly complicated manner in relation with industrial sectors and emission source types. It was found that both $H_{2}S\;and\;CH_{3}SH$ make the highest contribution to nuisance in the leather industry. Likewise, DMS showed its maximum contribution from food production sector, while DMDS for chemical production sector. When the emission data sets were compared between different emission sources, regardless of industrial types or activities, $H_{2}S\;and\;CH_{3}SH$ concentrations were seen most significant at waste treatment process. The overall results of our study suggest that the emission concentrations of sulfur compounds can be used to distinguish different sources of malodor released by different industrial activities.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.1
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• pp.107-118
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• 2005

In this study, the concentrations of major odorous compounds including reduced sulfur compounds (OMS, CS$_2$, and DMDS) and aromatic VOC (benzene, toluene, xylene, etc.) were measured continuously using an on-line GC analytical system. Our measurements were made from a residential area of Ansan sity during about two week period of October, 2004. The highest mean concentrations of Sand VOC were found as 56.9 pbb of DMS and 21.7 ppb of toluene, respectively. The results of this study generally show that the pollution levels for both types of chemicals are significant relative to previous measurement results reported from comparable sites, if the results are compared simply in terms of the magnitude of the measured concentration data. Moreover, when the relative importance of different compounds is compared in terms of the odor strength, it indicated that the contribution of reduced S compounds may be much more important than that of VOC in the study area.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.1
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• pp.83-90
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• 1998

Stage transformation characteristics of Li, K and Na-graphite deintercalation compounds (GDICs) were studied under consideration of a deintercalation mechanism of the intercalants between carbon layers. Li-graphite intercalation compounds (GICs) synthesized by a controlling temperatures and pressures have been spontaneously decomposed in the atmosphere. By X-ray differaction analysis the $d_{001}$-values of stage 1 and 2 were identified to be 3.71 and 7.06 $\AA$, respectively. After 6 weeks, the deintercalation reaction of the Li-GICs ceased and only residual compounds could be observed. K-GICs were synthesized by the modified two-bulb method resulting in structural stabilities and stage transitions. By X-ray diffraction analysis the very stable K-graphite residue compounds were observed after 10 weeks. Na-GICs with stage 1 and 2 were synthesized using the high temperature and pressure technique. The temperature dependence of a deintercalation reaction and a thermal stability of Na-GICs were discussed. The structure changes of the Na-GDICs depending on heating rates were identified by X-ray diffraction. According to the deintercalation process, the stage transformations could be attributed to irregular deintercalations of the GDICs with disordered stage.

• Natural Product Sciences
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• v.20 no.3
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• pp.160-169
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• 2014

44 compounds and 9 minerals were isolated from and detected in the New Zealand deer velvet antler Cervus elaphus var. scoticus L$\ddot{o}$nnberg. The chemical structures of (1 - 26) were identified on the basis of the spectroscopic methods and comparisons with literature, respectively. The structures were identified as cholesterol (CS, 6), 7-keto-CS (7), $7{\beta}$-hydroxy-CS (8), and $7{\alpha}$-hydroxy-CS (9), and included 12 steroid $3{\beta}$-O-(palmitic/stearic/myristic acid esters; PM/SA/MS) [CS-$3{\beta}$-O-PM (1 - 1), CS-$3{\beta}$-O-SA (1 - 2), CS-$3{\beta}$-O-MR (1 - 3), 7-keto-CS-$3{\beta}$-O-PM (2 - 1), 7-keto-CS-$3{\beta}$-O-SA (2 - 2), 7-keto-CS-$3{\beta}$-O-MR (2 - 3), $7{\beta}$-hydroxy-CS-$3{\beta}$-O-SA (3 -1), $7{\beta}$-hydroxy-CS-$3{\beta}$-O-PM (3 - 2), $7{\beta}$-hydroxy-CS-$3{\beta}$-O-MR (3 - 3), $7{\alpha}$-hydroxy-CS-$3{\beta}$-O-SA (4 - 1), $7{\alpha}$-hydroxy-CS-$3{\beta}$-O-PM (4 - 2), and $7{\alpha}$-hydroxy-CS-$3{\beta}$-O-MR (4 - 3)], dinonyl phthalate (5), 8 nucleic acids analogues [uracil (10), deoxyguanosine (11), deoxyuridine (12), uridine (13), deoxyadenosine (14), adenosine (15), inosine (16), and guanosine (17)], and the 9 free amino acids [L-phenylalanine (18), L-isoleucine (19), L-leucine (20), L-tyrosine (21), L-valine (22), L-proline (23), L-threonine (24), L-alanine (25), and L-hydroxyproline (26)]. Also, there are 8 kinds of amino acids [asparagine, serine, glutamine, glycine, histidine, arginine, methionine, and lysine], 2 sialic acids [N-acetylneuraminic acid (27), ketodeoxynonulosonic acid (28)], and 9 minerals [Na > K > Ca > Mg > Fe > Zn > B > Al > Cu] were detected from the autoaminoacid analyzer and ICP spectrometer, HPAEC-PAD/HPLC-FLD, respectively. 9 kinds of oxycholesterol-$3{\beta}$-O-fatty acid ester (2 - 1, 2 - 2, 2 - 3, 3 - 1, 3 - 2, 3 - 3, 4 - 1, 4 - 2, and 4 - 3) and 3 nucleic acids (12, 14, and 15) were isolated from the velvet antler for the first time. 6 kinds of steroids (7, 8, 9, 2 - 1, 3 - 1, and 4 - 1) were examined for their anti-proliferative effects against L1210, P388D1, K562, MEG-01, KG-1, MOLT-4, A549, HepG2, MCF-7, SK-OV-3, and SW-620 cancer cell lines. They showed anti-proliferative effects with $IC_{50}$ values of 0.06, 2.16, 2.42, > 50.0, 1.66 and $8.31{\mu}M$ against L1210, while the values were 24.05, 9.44, 5.22, 0.25. 9.48 and $49.77{\mu}M$ against P388D1, respectively. The others were inactive.

• Analytical Science and Technology
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• v.24 no.3
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• pp.212-218
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• 2011

In this study, temporal stability of 5 reduced sulfur compounds (RSCs) including ($H_2S$, $CH_3SH$, DMS, $CS_2$, and DMDS) was investigated up to 30 days. To learn the temporal changes in RSC concentration levels, two types of long-term storage experiment were carried out by employing two different approaches for sample storing in Tedlar bag samplers. The first one named as a forward (F) storage method consists of preparing all samples in the beginning of experiment. All these samples were analyzed sequentially through time. The second approach named as a reversed (R) storage method was carried out by preparing each sample through time and by analyzing all of them in the last day. For these experiments, RSC standards were prepared at 10 ppb in 10 L Tedlar bag. The results of both methods were consistent enough to show a tendency of the concentration reduction through time. Moreover, the lightest RSC, $H_2S$ showed the most significant reduction of 84.8% at the end of experiment. To validate difference between these results, t-test was applied to the data obtained between the two methods at 90% significance level. According to t-test, the results of the two approaches were greatly distinguished from 3 RSCs ($H_2S$, $CH_3SH$, and DMDS). The results also indicated that the temporal reduction of RSC differs greatly between light ($H_2S$ and $CH_3SH$) and heavy RSCs (DMS, DMDS, and $CS_2$). The former generally exhibited much significant reduction through time due probably to their lower stability.

• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.127-137
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• 2018

Radioactive contamination has become an important environmental concern after the accident occurred in Fukushima Daiichi Nuclear Power Plants. $^{134}Cs$ and $^{137}Cs$ are the major fission products and they are main problems in radioactive contamination. Huge amounts of Cs were released during the Fukushima Daiichi Nuclear Power Plants accident and as a result of this incident, many researchers focused on the development of adsorbents for decontamination of radiotoxic cesium. This review will critically evaluate recent advances in the preparation of Prussian blue and its analogue compounds, which are promising materials for cesium removal. Furthermore, this review will discuss recent studies on the cesium adsorption using different types of clay and clay based adsorbents and summarize various types of newly developed Cs adsorbents reported in recent years.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.42-47
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• 2024

The electrochemical extraction of uranium in ternary low melting LiCl-KCl-CsCl eutectic on inert and reactive electrodes via different electrochemical techniques was investigated. It was established that the electrochemical reduction process of U(III) ions on the inert W electrode was irreversible and proceeded in one stage. On reactive liquid Ga and liquid Cd electrodes the reduction of uranium ions took place with the considerable depolarization with the formation of UGa₂, UGa₃ and UCd₁₁ intermetallic compounds. Thermodynamic characteristics of uranium compounds and alloys were calculated. The conditions for the extraction of uranium from the electrolyte in the form of alloys on both liquid reactive electrodes via potentiostatic electrolysis were found.

• Textile Coloration and Finishing
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• v.30 no.2
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• pp.117-129
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• 2018

Cellulose has been widely applied into various medical fields including scaffolding, tissue engineering and tissue formation. In this study, we manufactured cellulose medical fiber from Styela clava tunics(SCT-CS) and analyzed the tensile strength, elongation at break, fluid uptake and surface morphology. And then, the biocompatibility and toxicity of SCT-CS were measured in Sprague-Dawley(SD) rats after the implantation for 30, 60 and 90 days. The level of tensile strength and fluid uptake were lower in SCT-CS than chromic catgut(CCG), while elongation at break level were maintained the higher in SCT-CS. Also, the roughness with pronounced surface patterns as a result of in vivo degradation was significantly greater in CCG than this of SCT-CS although these levels gradually appeared with time in both groups. After implantation for 90 days, SCT-CS and CCG was successfully implanted around muscle of thigh without any significant immune response. Furthermore, no significant alterations were measured in serum parameters and the specific pathological features induced by most toxic compounds for liver and kidney toxicity. Therefore, these results suggest that SCT-CS showing good biocompatibility and non-toxicity can be successfully prepared from cellulose powder of SCT as well as has the potential for use as a powerful biomaterial for medical sutures.