• Microbiology and Biotechnology Letters
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• v.20 no.2
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• pp.164-168
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• 1992

Enzymatic properties of avicelase, carboxymethyl cellulase (CMCase) and P-glucosidase produced by Cellulomonas sp. YE-5 were studied. Optimal temperature and pH of avicelase were 40t and 6.0, and those of CMCase and P-glucosidase were $45^{\circ}C$ and 6.5. Avicelase and CMCase were stable between pH 5.0 and 9.5, and &glucosidase was stable between pH 5.5 and 8.0. Avicelase and P-glucosidase were inactivated when incubated at $35^{\circ}C$ for 6 hrs, and CMCase was at $40^{\circ}C$ for 6 hrs. All cellulases were strongly inhibited by $Cu^{2+} \; and \; Zn^{2+}. K_m$ values of avicelase for avicel, CMCase I and CMCase II for CM-cellulose, and ($\beta$-glucosidase for p-nitrophenyl-$\beta$-D-glucoside (PNPG) were 4.76, 16.4, 16.4 $\mu g$/ml and 3.51 mM, respectively.

• Journal of environmental and Sanitary engineering
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• v.9 no.2
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• pp.1-7
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• 1994

Rainwater was collected in Seoul area from January 1991 to December 1993 (over 3years) and by the analysis of the chemical components contained in rainwater, investigated the components that effect on rainwater pH Through the above studies the following conclusions were obtained. 1) Method for Averaging pH Volume weighted method is considered to be acceptable providing that precipitation is measured at the same time when the samples are taken, without precipitation data a simple averaging method should be the next choice. 2) Annual average rainwater pH was 4.98 in 1991, 4.80 in 1992, 4.67 in 1993, measurement range was 3.6-8.1. 3) In the relationship between rainwater pH and rainfall amounts rainwater pH for light rain(<15mm rainfall) was existent in the wide range(pH 4-7), but for heavy rain was corresponded to the annual average values. 4) Annual frequency of pH was Birrndat the frequency($\gamma $) between the density of the [$H^{+}$] and pH in the rainwater(over 3years ), $NO_{3}^{-}$ was excellent and the obtained results was 0.62 in 1992. Also In the correlation coefficient($\gamma $) according to the pH range $SO_{4}^{2-}, NO_{3}^{-}$, were 0.85 ,0.68 at 3.6 $Cl^-$ was 0.99(1993). At 4.1$NO_{3}^{-}(\gamma=0.48)$ in 1992, SO_4^{2-}($\gamma$=0.54), $NO_{3}^{-}(\gamma$=0.72), $Cl^- (\gamma$=0.49) in 1993. 6) pH values gradually increased with increase in $Ca^{2+}/SO_{4}^{2-}$.

• Journal of Life Science
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• v.12 no.2
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• pp.129-135
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• 2002

Several kinds of thermophilic, aerobic microorganisms (Bacillus genus), metal leaching microorganisms (Thiobacillus, T. ferooxidans), and other nondegradable chemical-degrading microorganisms (Pseudomonas genus) were utilized to study the effect on composting livestock manure. Under the Carbon-Nitrogen ratio (C/N) of 35∼40 and water content of 50∼65% conditions, the composting in the cycling drum reactor showed slower composting and lower temperature increase than that of the manual reactor. Element analysis after composting indicated relatively high levels of mineral contents with the substitutional effect of chemical fertilizer. Metal analysis before and after composting showed lower As in all, Cr in pig, Pb in cow, Hg in chicken, and Cu in cow manure compost than the regulation values. Compost maturity was ascertained by the several maturity tests. Salmonella and E. cozi detection test by SS or EMB agar plate confirmed the safety from the pathogenic microorganisms. The results suggest that the inoculation of metal and some other chemical degrading microorganisms during composting might decrease metal contamination and increase composting rate.

• Journal of Food Hygiene and Safety
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• v.14 no.1
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• pp.115-121
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• 1999

The effect of storage temperature and time on the contents of metal (Pb, Sn and Fe), vitamin C, color and pH was studied for canned pineapple juice (PJ) and pineapple slice (PS) which were stored for 120 hours at 5 and 2$0^{\circ}C$ and analyzed at 24 hours intervals. The results are as follows; 1. The metal contents of PJ and PS were in the rank of 24<48<72<96<120 hours by storage time at 5 and 2$0^{\circ}C$. These contents were increased to 44.1%/24 hrs of Ph, 18.0%/24 hrs of Sn, 34.6%/24 hrs of Fe but decreased to 6.0%/24 hrs of vitamin C in PJ and PS during 120 hrs. Storage times were correlation to contents of metal and pH but was not correlation to vitamin C contents. These were increased to 37.7%/24 hrs of Pb, 18.8%/24 hrs of Sn, 34.6%/24 hrs of Fe, but decreased to 6.0%/24 hrs of vitamin C. 2. These were increased to 10.6% of Pb, 3.7% of Sn, 11.3% of Fe in PJ and to 33.7% of Pb, 4.8% of Sn, 37.6% of Fe in PS at 2$0^{\circ}C$ than 5$^{\circ}C$ but vitamin C contents were decreased to 8.2% in PJ and 2.7% in PS at 2$0^{\circ}C$ than 5$^{\circ}C$. This fact suggests that more attention be paid in handling canned PJ and PS after opening in order to avoid the decreasing vitamin C and the hazard from Pb, Sn, Fe. 3. Changing factors in Pb, Sn, Fe and vatiamin C content were in the rank of storage temperature$0^{\circ}C$.

• Fire Science and Engineering
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• v.27 no.5
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• pp.26-31
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• 2013

In nuclear power plant, anchor bolts for pressurizer supports are sufficiently used in terms of safety reason, but field inspections have reported that some bolts exceed the limit of their allowable hardness. Because the high level of hardness may lead to failures due to the stress corrosion or fracture toughness, a regular inspection is required for the bolts in nuclear power plant. Thus, this research measures the hardness of bolts currently used in pressurizer supports and then estimates maximum allowable stresses preventing failures by stress corrosion and fracture toughness. Using the ANSYS program, the stresses of the bolts in the regular condition and accidental condition have been calculated, and the possible maximum stress has been compared with the estimated allowable stresses. From the results, the stresses of bolts in the accidental condition satisfy the allowable safety stress from the stress corrosion failure. However, in the future, it shall be needed to consider the reflection of the structure assembling method on the assembling procedure to ensure the pressurizer integrity during maintenance period time.

• Korean Journal of Food Science and Technology
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• v.17 no.2
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• pp.89-94
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• 1985

Seventy nine swollen commercially canned grapes and peaches were collected from wholesale and retail outlets in Seoul area for the investigation of the causes of their swell. Hydrogen generation and microbial spoilage were the only two common causes of can swelling. Nevertheless, the spoilage profile of the two products was different. Seventeen out of twenty one canned peaches were spoiled by microorganisms, while the rest of five were swollen due to hydrogen generation. In contrast, fifty one out of fifty eight canned grapes were swollen due to hydrogen generation, while the rest of seven were spoiled by microorganisms. Seventeen yeast and five bacterial strains were isolated and only the yeasts were identified to their genera and species. Saccharomyces cerevisiae was the most frequently isolated spoilage yeast, closely followed by Torulopsis stellata. Candida parapsilosis, Pichia kluyveri, Pichia membranaefaciens, Torulopsis globosa and Torulopsis lactis-condensi were also isolated but with lower frequencies.

• Korean Journal of Food Science and Technology
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• v.18 no.4
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• pp.270-277
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• 1986

Ficin, a proteolytic enzyme in Fig latex, was extracted and purified with using ammonium sulfate and CM-cellulose column chromatography, respectively, and studied for its chemical properties. The disc gel electrophoresis showed one major and three minor bands for $(NH_4)_2SO_4$ extract and only one band showed after CM-cellulose chromatography. The optimum conditions for ficin activity was found to be pH 7.0 and $50^{\circ}C$. The amino acids composition of the purified ficin were 21.8% as acidic, 3.5% as basic and 74.7% as neutral amino acids. The amino acids analysis indicated that the ficin was composed of 174 amino acids residue having molecular weight of 19,500.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.371-379
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• 1988

To investigate on the biochemical characteristics of myofibrillar proteins between cold(pollack, salmon) and warm current fish (yellow corbina, shark), myofibrils and actomyosin were prepared, and their biological activities, effect of temperature on the myofibrillar ATPase activities and SDS-polyacrylamide gel electrophoretic patterns of myofibrils were compared. SDS-polyacrylamide gel electrophoretic analysis showed that electrophoretic patterns of myofibril vary from fish to fish. Difference in KCl concentration dependency of myofibrillar ATPase activities and ATPase activity- pH curve were found among fish species. Myofibrillar proteins from cold current fish showed higher specific activity at low temperature $(5^{\circ}C-10^{\circ}C)$ than those from warm current fish.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2006.05a
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• pp.98-101
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• 2006

본 연구는 사육면적에 따른 비육후기 28개월령 비거세 한우육의 냉장중 PH, 보수력, 지방산 조성 및 전자코에 의한 향기 패턴 비교를 구명하고자 실시하였다. 도축전 6개월 동안 사육면적(9, 18, 27 $m^2$)에 따라 공시하고 도축후 등심(M. longissimus) 부위를 $4{\pm}0.5^{\circ}C$에 9일 동안 저장하면서 실험하였다. pH는 저장 3일까지 27 $m^2$에서 사육한 한우육이 9, 18 $m^2$에서 사육한 한우육보다 유의적으로 높았다(p<0.05). 사후강직후 48시간의 드립 감량은 27 $m^2$에서 사육한 한우육이 9, 18 $m^2$에서 사육한 한우육보다 유의적으로 낮았다(p<0.05). 지방산 조성에서 C20:5n3(EPA)과 PUFA n3 지방산 총량은 27 $m^2$에서 사육한 한우육이 9 $m^2$에서 사육한 한우육보다 유의 적으로 높았으며(p<0.05), PUFA n6/n3 비율은 낮았다(p<0.05). 전자코의 PCA에 의한 향기 패턴은 저장기간 동안 사육면적에 따른 차이가 나타나지 않았다. 따라서 27 $m^2$에서 사육한 비거세 한우육의 보수력 및 PUFA n3 지방산 함량이 가장 높았으며, PUFA n6/n3 비율은 가장 낮았다.

• Applied Biological Chemistry
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• v.35 no.4
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• pp.260-264
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• 1992

In present paper, we investigated the quality stability of sardine burgers during storage at $-20{\pm}2^{\circ}C$. During frozen storage of sardine burger, the PH were decreased, while volatile basic nitrogen contents were increased. The results of changes in peroxide values, thiobarbituric acid values, fatty acid compositions and color values during frozen storage showed that lipid oxidation and discolorization of antioxidant treated sardine burger and vacuum packed sardine burger could be effectively retarded. The changes in the taste compounds such as free amino acid, nucleotide and their related compounds, total creatinine, betaine and trimethylamine oxide, total amino acids and texture profile analysis of vacuum packed sardine burger were negligible during frozen storage. From the results of sensory evaluation and chemical experiments, the vacuum packed sardine burger could be preserved in good quality during frozen storage of 90 days.