• Journal of Life Science
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• v.22 no.7
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• pp.981-986
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• 2012

To produce a new tea with a good flavor and functional properties using green tea of low quality, naked barley and barley were selected to blend with the green tea. The simultaneous distillation extraction method (SDE) using Likens and Nickerson's extraction apparatus was used to extract the volatile flavor compounds from the samples. The concentrated flavor extracts were analyzed and identified by GC and GC-MS. The GC patterns of the flavor components in two parched barleys were very different. The main volatile flavor components in two of the samples were alkyl pyrazines. Compounds including 3-methylbutanal, 2-methylbutanal, dihydro-2-methyl-3(2H)-furanone, 2,5-dimethyl pyrazine, and 3-ethyl-2.5-dimethyl pyrazine were isolated from the naked barley. Compounds including thiophenes, thiazoles, sulfides, and pyrroles with burnt odor were isolated from the barley. The parched naked barley was better than barley for adding to green tea. The main aroma components of the green tea blended with the naked barley were hexanol, hexanal, trans-2-hexenal, ${\beta}$-ionone, ${\alpha}$-ionone, alkyl pyrazines, 3-methylbutanal, 2-methylbutanal, and furfural.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.4
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• pp.226-234
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• 2002

A sediment exposure experiment was conducted to investigate the influence of acid volatile sulfides (AVS) and simultaneously extracted metals (SEM) in sediments on the bioavailability and toxicity of Cd, Ni and Zn to a marine polychaetes Neanthes arenaceodentata. The test animals were exposed to contaminated sediments spiked by metal mixtures of Cd, Ni, Zn (0.5～15 $\mu$mol/g of total SEM) in low (～1 $\mu$mol/g), medium (～5 $\mu$mol/g) and high AVS series (～10 $\mu$mol/g) to determine bioaccumulation, mortality and individual growth rate in each treatment after 20 days. Cd and Zn bioaccumulation in test animals increased with increasing of overlying water (OW) concentration controlled by AVS. In contrast, Ni bioaccumulation increased with increase of SEM concentration. Mortalities and growth inhibitions of N. arenaceodentata observed in only treatments with ［SEM-AVS］>0, due to a high level of OW-Zn. With regard to the mortality, the 20-d LC5O value fur OW-Zn was 9.3(8.0$\pm$11.0) $\mu$M. The LOEC (Lowest Observed Effect Concentration) for Tissue-Zn was 7.8 $\mu$mol/g and the NOEC (No Observed Effect Concentration) was 6.2 $\mu$mol/g. Regarding the inhibition of individual growth rate, the LOEC fer Tissue-Zn was 5.9 $\mu$mol/g, and NOEC was 5.1 $\mu$mol/g. In this study, the toxicity of dissolved metals, especially for Zn, was overemphasized due to the reduced distribution coefficients (K$\_$d/s) of metals in the experimental sediments.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.6
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• pp.529-536
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• 1986

By modified method yellow corvenia(called $Y_3$) was prepared with $4\%$ salt, $4\%$ KCl, $6\%$ sorbitol, $0.5\%$ lactic acid and $4\%$ alcohol extract of red pepper to improve the quality of fermented sea food. In this study, changes of volatile compounds and fatty acid composition obtained from modified fermented yellow corvenia($Y_3$) were experimented during fermentation, comparing with conventional fermented yellow corvenia(called $Y_1,\;20\%$ of salt contents). Total lipid of yellow corvenia was composed of $78.1\%$ of neutral lipid, $21.2\%$ of phospholipid and $0.7\%$ of glycolipid. And monoeonoic acid was held $37.4\%$ of fatty acid composition of total lipid and saturated fatty acid ($34.8\%$), polyenoic acid ($27.7\%$) were followed. Saturated fatty acid($C_{14:0},\;C_{16:0},\;C_{18:0}$) in $Y_1,\;Y_3$ increased, polyenoic acid ($C_{22:6}\;C_{22:5}\;C_{20:5}$) decreased while monoenoic acid($C_{16:1}\;C_{18:1}$) in those was little fluctuated during fermentation. Thirty-three kinds of volatile component in whole volatile compounds obtained from $Y_1,\;Y_3$ at 90 days fermentation were identified, and composed of some hydrocarbons (8 kinds), alcohols (7 kinds), acids (6 kinds), aldehydes(4 kinds), sulfides(2 kinds), ketones (2 kinds), one of phenol and 3 kinds of the other components. Among the whole volatile compounds 2-ethoxy ethanol and was held $79.35\%$ in $Y_3$, whereas nonadecane was held $75.85\%$ in $Y_1$. During fermentation 8 kinds of volatile acids, 5 kinds of amines and 9 kinds of carbonyl compounds were also detected. Those volatile acid such as acetic acid, isovaleric acid, n-caproic acid, n-butyric acid were the major portion of total volatile acids in $Y_3$ at 90 days fermentation. Meanwhile, carbonyl compounds such as ethanal, 2-butanone and butanal were the major ones, while TMA held the most part of volatile amines in $Y_3$ during fermentation. From the result of sniff test, the components which are believed to contribute to the characteristic flavor of fermented product $Y_1,\;Y_3$ are deduced to be volatile acid, carbonyl compounds and amines in order. Conclusively, there was little difference in composition of volatile components, but merely a little difference in content of those between $Y_3$ and $Y_1$.

• Fisheries and Aquatic Sciences
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• v.13 no.3
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• pp.244-253
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• 2010

The quality of marine sediments from the industrialized coastal areas of Korea (Ulsan Bay, Masan Bay, and artificial Lake Shihwa) was investigated using a bacterial bioluminescence toxicity test. Sediment toxicity results were compared with the levels of chemical contamination (trace metals, organic wastewater markers, acid volatile sulfides, total organic carbon). Effective concentration 50% (EC50) of sediments ranged from 0.014 to 1.126 mg/mL, which is comparable to or lower than values in contaminated lakes, rivers, and marine sediments of other countries. Sediment reference index (SRI) ranged from 13 to 1044, based on the EC50 of the negative control sample. Mean average SRI values in Masan Bay and Lake Shihwa were approximately 8 and 9 times as high as that in Ulsan Bay, indicating higher sediment toxicity and greater contamination in the two former regions. Sediment toxicity were strongly associated with the concentrations of some chemicals, suggesting that this test may be useful for determining potential chemical contamination in sediments.

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.555-561
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• 1990

Aromas of sulfur-containing volatiles from two vegetable varieties of Cruciferae Brassica oleracea and the suppression of undesirable sulfurous aromas of cruciferous vegetables by sulfhydryl oxidase of caraway seeds were examined. Aroma components were separated by gas chromatography equipped with a dual flame photometric detector The volatile sulfides produced from cabbage and broccoli varied. in the relative quantities and rates of production. according to the amount of caraway seeds added and incubation time. The amount of methanethiol and dimethyl disulfide in the cabbage and broccoli with caraway seeds was far less than those in the cabbage and broccoli. Removal of methanethiol and dimethyl disulfide was proportional to the amount of caraway seeds added, and was remarkable with 2.5% aqueous slurries of caraway seeds added.

• Natural Product Sciences
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• v.11 no.2
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• pp.67-74
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• 2005

The ethanolic extracts of the leaves and bulbs of Allium victorialis var. platyphyllum (Liliaceae) collected from Daegwallyoung (D) and Ullung Island (U) in Korea were obtained using three different extracting methods. The first extracts, DL-1 DB-1, UL-1 and UB-1, were obtained from leaves (L) and bulbs (B) dried at $90^{\circ}C$, respectively, and the second extracts, DL-2, DB-2, UL-2 and UB-2, were obtained by extracting the leaves and bulbs of fresh plant parts. The third extracts DL-3, DB-3, UL-3 and UB-3 were obtained by incubating leaves and bulbs at $36^{\circ}C$. The six extracts obtained from A. victorialis var. platyphyllum at Daegwanllyoung (cultivated site) were orally administered to examine for a possible antihepatotoxic effect in $CCl_4-induced$ rats. DL-1 exhibited the most pronounced effect. The extracts inhibited serum ALT, AST, SDH, ${\gamma}-GT$, ALP and LDH activities elevated by $CCl_4$ injection and attenuated decreased glutathione S-transferase, glutatione reductase and ${\gamma}-glutamylcysteine$ synthetase activities and a decreased hepatic glutathione. However, the extracts obtained from Ullung Is. (native site) were less active than the extracts from Daegwallyoung, suggesting that A. victorialis var. platyphyllum from the cultivated site is more useful for functional food than of native site. These results also suggest that the antihepatotoxic effect is due to a higher content of hepatic glutathione. Gas chromatography of the twelve extracts showed significantly different sulfides, disulfides or trisulfides contents belonging to volatile sulfur substances (VSS). Nine components were identified on the basis of their mass spectra, namely, dimethyl disulfide, dimethyl trisulfide, diallyl disulfide, dipropyl disulfide, allyl methyl sulfide, allyl methyl trisulfide, 2-vinyl-4H-1,3-dithiin, 3,4-dihydro-3-vinyl-1,2-dithiin, and allithiamine. Extract DL-1 had the highest VSS content. Dried plant materials contained larger amounts of the VSSs than other extracts, and the leaves contained larger amount than the bulbs. These results suggest that heat treatment increases the antiheaptotoxic ability of A. victorialis var. platyphyllum by increasing the proportion of VSSs.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.919-923
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• 2004

Effects of adding 0, 2, 4, 6, and 8% freeze-dried kimchi powder (FDKP) on kimchi snack quality were examined. Headspace volatile compounds of 4% FDKP snack, receiving highest overall preference in sensory evaluation results, were analyzed, and 26 compounds were identified, including 13 aldehydes, 3 sulfides, a ketone, an acid, a terpene, and 7 other compounds. Pearson correlation analyses were carried out to determine a correlation between the concentration of FDKP and the amount of each volatile compound. Acetaldehyde, propanal, dimethyl sulfide, dimethyl disulfide, acetic acid, and d-limonene showed correlation coefficients above 0.90; selective ion move (SIM) analysis also showed above 0.97 for highly correlated compounds. Results suggest that these compounds can be used as indicators fur kimchi flavor of FDKP snack.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.351-355
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• 2002

Volatile compounds of kimchi-flavored steak sauce were isolated using simultaneous steam distillation and solvent extraction methods and identified by matching mass spectrum and retention index (RI) with the reference data. Twenty-three compounds including five aldehydes, four alcohols, four acids, three sulfur-containing compounds, one ketone, and six others were identified, among which the most abundant compound was eugenol. Sulfides such as dimethyl dis- and trisulfides, and acids such as acetic and dodecanoic acids showed strong effects on the kimchi flavor. Aroma extract dilution analysis with three fold dilution factor shown in over the FD value 34 identified 2-butanal, 2-pentylfuran, methyl-2-propenyl disulfide, and 2-furanmethanol. Strong good aroma was detected in the RI range between 1030 and 1357, bad aroma in RI 1561, sweety aroma in RI 2057, clover aroma of eugenol in RI 2122, and rancid flavor in RI 2251.

• Korean Journal of Materials Research
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• v.23 no.8
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• pp.405-422
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• 2013

Atomic layer deposition(ALD) is a promising deposition method and has been studied and used in many different areas, such as displays, semiconductors, batteries, and solar cells. This method, which is based on a self-limiting growth mechanism, facilitates precise control of film thickness at an atomic level and enables deposition on large and three dimensionally complex surfaces. For instance, ALD technology is very useful for 3D and high aspect ratio structures such as dynamic random access memory(DRAM) and other non-volatile memories(NVMs). In addition, a variety of materials can be deposited using ALD, oxides, nitrides, sulfides, metals, and so on. In conventional ALD, the source and reactant are pulsed into the reaction chamber alternately, one at a time, separated by purging or evacuation periods. Thermal ALD and metal organic ALD are also used, but these have their own advantages and disadvantages. Furthermore, plasma-enhanced ALD has come into the spotlight because it has more freedom in processing conditions; it uses highly reactive radicals and ions and for a wider range of material properties than the conventional thermal ALD, which uses $H_2O$ and $O_3$ as an oxygen reactant. However, the throughput is still a challenge for a current time divided ALD system. Therefore, a new concept of ALD, fast ALD or spatial ALD, which separate half-reactions spatially, has been extensively under development. In this paper, we reviewed these various kinds of ALD equipment, possible materials using ALD, and recent ALD research applications mainly focused on materials required in microelectronics.

• 한국해양학회지
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• v.28 no.3
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• pp.229-240
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• 1993

This study investigated the behaviour of sulfur species after the early diegenetic reduction of sulfate from pore solution in an anoxic intertidal flat deposit in the Banweol area of Kyeong-gi Bay, west coast of Korea. A total of seven sediment cores were collected during 1990∼1992 and were analyzed for their solid-phase sulfur species (acid-volatile sulfur, element sulfur, pyrite sulfur) as well as for chemical components in the pore solution, such as sulfate, ammonium, hydrogen sulfide, phosphate and Fe ion. The pore water sulfate oncentration was found to decrease rapidly downward from the sediment surface, while that of hydrogen sulfide, ammonium and phosphate showed and increase. The dissolved iron concentration in pore water, on the other hand, was found high in the surface layer of sediment, but fell sharply below this layer. these characteristic profiles of pore water sulfide and iron concentrations suggest that some reaction occurs between dissolved iron and sulfide ions, leading to the formation of various sulfide minerals in the sedimentary phase. The amount of inorganic sulfur species in the sediment increased downward, and showed a maximum of up to 7.9 mg/g. among the three species analyzed, acid-volatile sulfur (AVS) was dominant comprising more than 50% of the total. The amount of pyrite sulfur was greater than that of element sulfur. This implies that the formation of pyrite was restricted in this environment. the limited amount of element sulfur in this deposit may have discouraged the active formation of pyrite.