• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.2
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• pp.95-104
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• 2005

Effects of the aluminum melting temperature, melting time and a kind of flux agents on the distribution of surrogate nuclide were investigated in the electric furnace at the aluminum melting including surrogate radionuclides(Co, Cs, Sr) in order to establish the fundamental research of the melting technology for the metallic wastes from the decommissioning of the TRIGA research reactor. It was verified that the fluidity of aluminum melt was increased by adding flux agent but it was slightly varied according to the sort of flux agents. The results of the XRD analysis showed that the surrogate nuclides move into the slag phase and then they were combined with aluminum oxide to form more stable compound. The weight of the slag generated from aluminum melting test increased with increasing melting temperature and melting time and the increase rate of the slag depended on the kind of flux agents added in the aluminum waste. The concentration of the cobalt in the ingot phase decreased with increasing reaction temperature but it increased in the slag phase up to 90$\%$according to the experimental conditions. The volatile nuclides such as Cs and Sr considerably transferred from the ingot phase to the slag and dust phase.

• Applied Biological Chemistry
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• v.36 no.1
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• pp.58-63
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• 1993

In the present paper, we investigated the quality stability of mackerel based burger during frozen storage. The moisture and crude lipid contents of products were $60.2{\sim}61.5%$ and $14.7{\sim}14.9%$, respectively. The pH showed a tendency of decrease, while volatile basic nitrogen content showed a tendency of increase during frozen storage. The histamine content was $2.60{\sim}2.81\;mg/100g$, and this value increased slowly during frozen storage. The increasing ratio in the peroxide value, carbonyl value, TBA value, fatty acid composition and color value of vacuum packed product and antioxidants added product were lower than those of air packed product. The texture profile analysis parameters such as hardness and toughness showed a tendency of a slight increase in air packed product and showed less increase in vacuum packed product and antioxidants added product. From the results of chemical experiments and sensory evaluation during frozen storage, it is concluded that the vacuum packed mackerel based burger and antioxidants added mackerel based burger were good condition for preserving the quality during frozen storage of 60 days.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.98-101
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• 1991

To investigate the aroma difference of commercial Korean green tea caused by manufacturing process and harvesting time, analysis of aroma concentrates of steamed green teas(1st tea, 2nd tea) and parched green teas(1st tea, 2nd tea) was accomplished. Steamed green tea, which had a briskness, greenish odor and sweet-floral odor, contained large amounts of terpene alcohols such as linalool, nerolidol, ketones such as cis-jasmone, 2,6,6-trimethyl-2-hydroxycyclohexanone and indole, Parched green tea, which had a slightly greenish odor and floral, roast odor, contained large amounts of terpene alcohols such as linalool, geraniol, aromatic alcohols such as benzylalcohol, phenylethanol and phenol, indole. Almost same tendency of odor component change of 1st tea and 2nd tea differed to harvesting time being observed in steamed tea and parched tea. In 2nd tea of both samples, aliphatic alcohols such as 1-penten-3-ol, cis-2-penten-1-al and two 2, 4-heptadienal(cis, trans and trans, trans) increased remarkably. It seems that these four components effects on the grade of the odor.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.301-305
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• 2016

This study was conducted to investigate changes in pH, volatile basic nitrogen (VBN), thiobarbituric acid (TBA), $a^*$ (redness), shearing force, and microbial content (total plate count; TPC) in beef during freezing storage at -1, -5, and $-20^{\circ}C$ for 21 days. TPC as an effective quality indicator was used to identify the decay point by regression analysis. The pH, TBA values, and TPC significantly increased with storage at all tested temperatures (p<0.05). VBN significantly increased and shearing force significantly decreased with storage at -1 and $-5^{\circ}C$ (p<0.05). TPC showed significant correlation with temperature at $-1^{\circ}C\;(R^2=0.891)$, $-5^{\circ}C\;(R^2=0.856)$, and $-20^{\circ}C\;(R^2=0.444)$. The decay points at -1, -5, and $-20^{\circ}C$, were 27, 52, and 84 days, respectively. The results suggest that a freezing temperature of $-5^{\circ}C$ is effective for short-term storage of beef.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.1
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• pp.13-20
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• 1993

Traditional fermented fish products 'Jeodtgal' have been prepared with addition of about $25\%$ salt to prevent spoilage, but domestic seasoned and fermented products have only about $8\%$ salt, so they have been required careful treatment during distribution and could have a different fermentation pattern from traditional 'Jeodtgal' This study was conducted to establish shelf-life of seasoned and fermented squid at different distribution conditions. To establish shelf-life of seasoned and fermented squid stored at $10^{\circ}C,\;20^{\circ}C$ and $30^{\circ}C$, chemical components and sensory evaluation were investigated. Chemical components such as volatile basic nitrogen(VBN), ammonia nitrogen ($NH_3-N$) and total nitrogen(T. N) rapidly increased during storage at $20^{\circ}C$ and $30^{\circ}C$, but pH value and Hunter color value(${\Delta}E$) slowly decreased during storage without respect of storage temperature. Judging from chemical components analysis and senseory evaluation, seasoned and fermented squid could be storage for 3days at $30^{\circ}C$, 7days at $20^{\circ}C$ and 25days at $10^{\circ}C$, respectively. The ratio of quality deterioration per hour were 0.00166 at $10^{\circ}C$, 0.00595 at $20^{\circ}C$ and 0.01385 at $30^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.2
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• pp.240-247
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• 2012

Dietary supplementation with conventional linted cottonseed hulls (LCSH) is a common practice in livestock production all over the world. However, supplementation with mechanically delinted cottonseed hulls (DCSH) and cottonseed linter residue (CLR) is uncommon. Cottonseed by-products, including LCSH, DCSH and CLR, were assessed by chemical analysis, an in situ nylon bag technique, an in vitro cumulative gas production technique and in vitro enzyme procedure. The crude protein (CP) content of CLR (302 g/kg dry matter (DM)) was approximately 3 times that of LCSH and 5 times that of DCSH. The crude fat content was approximately 3 times higher in CLR (269 g/kg DM) than in LCSH and 4 times higher than in DCSH. Neutral detergent fibre (311 g/kg DM) and acid detergent fibre (243 g/kg DM) contents of CLR were less than half those of DCSH or LCSH. Metabolisable energy, estimated by in vitro gas production and chemical analyses, ranked as follows: CLR (12.69 kJ/kg DM)>LCSH (7.32 kJ/kg DM)>DCSH (5.82 kJ/kg DM). The in situ degradation trial showed that the highest values of effective degradability of DM and CP were obtained for CLR (p<0.05). The in vitro disappearance of ruminal DM ranked as follows: CLR>LCSH>DCSH (p<0.05). The lowest digestibility was observed for DCSH with a two-step in vitro digestion procedure (p<0.05). The potential gas production in the batch cultures did not differ for any of the three cottonseed by-product feeds. The highest concentration of total volatile fatty acids was observed in CLR after a 72 h incubation (p<0.05). The molar portions of methane were similar between all three treatments, with an average gas production of 22% (molar). The CLR contained a higher level of CP than did LCSH and DCSH, and CLR fermentation produced more propionate. The DCSH and LCSH had more NDF and ADF, which fermented into greater amounts of acetate.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.7
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• pp.418-425
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• 2015

Anaerobic Filters (AF) packed with porous ceramic floating media were operated at different operational conditions to identify the feasibility of the renewable bioenergy, methane production from swine wastewater and to verify the suitability of effluent from anaerobic filters for the subsequent biological nitrogen and phosphorus removal. Stepwise increase in organic loading rates (OLRs) or decrease in hydraulic retention times (HRTs) with influent TCOD concentration of 14,000 mg/L were utilized at mesophilic temperature. The maximum methane productivity of 1.74 volume of $CH_4$ per volume of reactor per day (v/v-d) was achieved at an hydraulic retention time (HRT) of 0.5 day (OLR 28 g TVS/L-d). Based on the biogas production, the highest total volatile solids (TVS) removal efficiency of 63% was obtained at an HRT of 3 days (OLR 4.67 g TVS/L-d), however based on the result from the effluent total chemical oxygen demand (TCOD) analysis, the highest TCOD removal efficiency of 75% was achieved. The effluent alkalinity concentration over the range of 2,050~2,980 mg/L as $CaCO_3$ at all operational conditions, could compensate the alkalinity destruction caused by nitrification. The effluent from the anaerobic filter operated under the HRT of 2 days showed the COD/TKN ratio of 15~35 and COD/TP ratio of 38~56. Therefore effluent C/N/P ratio is able to satisfy the optimum COD/TKN ratio of greater than 8.0 and COD/TP ratio of 33 for the subsequent biological nutrient removal.

• Journal of Wetlands Research
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• v.9 no.1
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• pp.107-114
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• 2007

This study aimed to investigate the hexachlorobenzene (HCB) dechlorinating ability of sediment microbes collected from a natural canal receiving secondary effluents from an industrial estate and nearby factories. Nine sites along the stream and one in the estuary in the Gulf of Thailand into which the canal spills were specified and sampling for sediment and water. Preliminary analysis of the sediments showed that the first four sites nearest to the discharging location were contaminated by HCB within the range of 0.18 to 1.25 ppm. Apart from that, 1,3,5-trichlorobenzene which has never been commercially produced or used in any manufacturing processes except for the transformation from higher chlorinated benzene was also identified in the range of 0.16 to 0.24 ppm. This suggested a possibility of sporadically HCB contamination in this stream. Of more important, people in the community along this canal earn their living by coastal fishery; hence, posing a risk of spreading HCB and its less chlorinated congeners via food chain from caught marine creatures to human. As a result, there is an urgent need to understand the behavior of HCB dechlorination in this stream sediment which can lead to a clean-up action in the future. Serum bottles with sediment slurries (sediment to water ratio of 1:1 (v/v) and filtered to remove particles larger than 0.7 mm) from each site were inoculated with 2 mg/l of HCB, kept anaerobically in the dark at room temperature without any nourishment, and analyzed for HCB and its less-chlorinated congeners every 6 days. Total chemical oxygen demand, suspended solids, and volatile suspended solids were in the range of 21,492-73,584, 158,100-518,100 and 6,000-32,700 mg/l, respectively. It was found that all sediment slurries began to dechlorinate HCB in 12 to 30 days and the HCB was completely removed within 42 to 60 days or so. On the other hand, there was no HCB dechlorination occurred in the controlled set which was sterilized by autoclaving prior to the addition of HCB. This implies that the HCB transformation was solely due to microorganisms' activities. HCB was dechlorinated principally via pentachlolobenzene to 1,2,3,5-tetrachlorobenzene and terminated at 1,3,5-trichlorobenzene which is the major pathway as reported by many researchers. Dichlorobenzene has not been detected in any samples within the dechlorination period of 60 days. The results indicate that the microbial matrix in the sediment of this stream has an outstanding capability to dechlorinate HCB. Existing substrates and nutrients which mainly sorbed onto the solid phase and the typical temperature in Thailand were sufficient and suitable to promote the activities of these HCB-dechlorinating microbes.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.312-320
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• 1996

This study was to investigate the changes of phytotoxicity of food waste during composting at an aerated static pile for 80 days. The concentration of sodium in the final compost increased by more than 30% and almost of the sodium was a water soluble type which corresponds to about 94% of the total concentration. Major volatile fatty acid(VFA) produced during the composting was acetic acid and also somewhat of butyric acid. High concentration of acetic acid during the composting was kept up for a month and then decreased progressively. It suggests that the phytotoxicity by the VFAs produced during composting of food waste could be removed through a stabilization process in a period of about 40 days. From the statistical analysis between germination index(G.I.) and VFAs. or G.I. and sodium, the phytotoxicity of food waste samples was more dependent in the changes of acetic acid concentration than that of sodium concentration. Considering low G.I. value in the final food waste compost which is matured completely, however. the agricultural utilization of the food waste compost may be to have a big problem due to excess sodium of the compost which is impossible to remove by composting and seriously inhibits growth of plants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.671-675
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• 2008

Based on information about the major microbial composition of kimchi and its relation to the taste, Leuconostoc mesenteroides K2M5 and Lactobacillus sakei K5M3 were selected as kimchi starter candidates. These two strains were found to be safe for industrial use because they showed neither harmful characteristics like ${\beta}$-hemolysis, ammonia and indole formation, and gelatin liquefaction, nor enzymatic activities like phenylalanine deaminase, ${\beta}$-glucuronidase, ${\beta}$-glucosidase, 7${\alpha}$-dehydroxylase and nitroreductase. Starter kimchi made with these strains were better in taste than the conventional kimchi when they are evaluated both by laboratory personnel and the public. Also microbial analysis of starter kimchi showed only starter bacteria after they were fermented to have the optimum acidity. Starter kimchi prepared with these two strains were not much different in physicochemical properties to the conventional kimchi except in that the starter kimchi were much higher in volatile organic acid content such as lactic acid. These results suggest that kimchi quality can be controlled to have consistent properties, both in taste and microbial composition, by using bacterial starters.