• Proceedings of the Korean Nuclear Society Conference
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• 2001.10a
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• pp.247.1-247
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• 2001

• Journal of Korean Society of Water and Wastewater
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• v.19 no.6
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• pp.767-774
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• 2005

The DOF (Dissolved Ozone Flotation) system was used to treat the effluent of the secondary wastewater treatment plant. The DOF system uses ozone instead of air, while DAF (Dissolved Air Flotation) uses air. Moreover, since the solubility of ozone is higher than air, the DOF system produces larger volume of micro-bubbles than the DAF system does. Thus, the DOF system performs better than the DAF system in floating ability. The DOF system could remove 70% of turbidity to an average of 0.59NTU in effluent from 2.31NTU in influent. The removal efficiency of absorbance measured with UV-254 in the effluent of the DOF system was 63%, while only 19% was removed by the DAF system. the DOF system removed 84% of the color from 25~26CU to 4CU, while DAF system removed 42% of the color to 15 CU. The CODMn removal efficiency of the DOF system was 34%, 6.8mg/l of effluent $COD_{Mn}$ concentratin, while it was 20%, 8.3mg/L of effluent $COD_{Mn}$ concentratin, to use the DAF system. Microbial bacteria such as coliform bacteria, and heterotrophic bacteria were removed over 99% by the DOF system, and 42~45% by the DAF system. That is, Microbial bacteria were almost completely destroyed by the DOF system. To sum up with, the DOF system was found to be very effective to treat effluent of the wastewater treatment plant.

• 한국디지털정책학회:학술대회논문집
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• 2006.12a
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• pp.285-298
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• 2006

The third party logistics(3PL) is given a definition as logistics activaties providing a comprehensive logistics services, all or partly outsourced by the customer on longer term contract basis, ranging from making logistics strategies to implementing information technology services. The growth of the Third Party Logistics (TPL) business has caused many firms from different industries to enter the field. In this study, it is presented to describe a defintion and development precess of the third party logistics and shown to present strategic issues comparing to third party in foreign and domestic area. and apply some issues of importance when managing the continued TPL business strategy in domestic area.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.5
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• pp.527-534
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• 1997

Freezing of an aqueous sodium cWoride solution (Nacl- H20) saturating a packed bed with ini¬tial salt concentrations of 5, 10, 15(k by weight is investigated experimentally in a rectangular cav¬ity. The system was cooled from the top, bottom and a vertical side wall. For the freezing experi¬ments from below, there was little effect of the initial salt concentration throughout the freezing process, and the global freezing rate was not affected by the initial salt concentration. For the freezing from above, the size of the mush region decreased and the mushlliquid interface became flatter as the initial liquid concentration is decreased. For the freezing from vertical side wall, reheating of the mixture was intensified with an increase in the initial salt concentration. For Ci= 5%, supercooling was observed only at the early times of freezing process, but for Ci= 15% small supercooling was observed throughout the freezing process.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.6
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• pp.253-256
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• 2004

Growth of ZnO epitaxial films have been carried out on (0001) sapphire substrates by RF magnetron sputtering. The single crystalline ZnO films of the thickness about 400-500 mm were grown successfully. At the various substrate temperatures of 200～$600^{\circ}C$, the growth behavior and optical properties of the epitaxial films have been characterized. As-grown ZnO films were annealed at the temperatures of 400, 600 and $800^{\circ}C$ respectively in order to characterize the optical properties. The carrier concentration of ZnO films annealed at the temperature of $600^{\circ}C$ was measured $2.6${\times}$10^{16}\textrm{cm}^{-3}$ by Hall measurements.

• Journal of Nutrition and Health
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• v.29 no.5
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• pp.472-479
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• 1996

To investigate the effect of dietary lipids and stress on brain catecholamine and serotonin concentration, sixty three weanling male Sprague-Dawley rats(mean body weight$\pm$SD : 171$\pm$3g) were fed a diet containing fish oil, soybean oil or beef tallow and than, each was exposed to three different types of stress, isolated, grouped or cold, respectively. Cold stress seemed to be most severe and living together in a large cage with some playing equipments is more stressful than living alone in a classical small cage evidenced by plasma corticosterone level. Average food intake and body weight gain were not significantly different among exprimental groups. In adrenal catecholamines, norepinephrine was significantly affected by diet and stress and dopamine was by stress. Norepinephrine concentration of the fish oil group was lowest among diet groups. Adrenal epinephrine, however, was not. It was also shown than the cold stress significantly increased the brain norepinephrine concentration. The cold stress significantly induced higher content of brain serotonin than the grouped stress. However, the concentratin of 5-hydroxyindoleacetic acid(5-HIAA), the metabolite of serotonin, was not significantly different among groups. Therefore, this results suggest that stress affects sympathetic neuronal activity, and fish oil might lighten the burden of stress.

• Applied Biological Chemistry
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• v.35 no.6
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• pp.501-506
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• 1992

Pepsin-catalyzed hydrolysis and plastein reaction were carried out to prepare plastein product from soymilk residue protein. Conditions required for optimal hydrolysis of soymilk residue protein and subsequent plastein production were investigated. The optimum substrate concentration, enzyme-substrate ratio, pH, reaction temperature and incubation time for hydrolysis were 3%, 1/50, 1.7, $45^{\circ}C$ and 24 hours, respectively. Plastein formation from peptic hydrolysate of soymilk residue protein was most effective at substrate concentratin of 40%, pH 4 and $45^{\circ}C$. Reaction time of 18 hours and enzyme-substrate ratio of 1/100 were selected for plastein production. Electrophoresis of the products revealed that protein-like substances of high molecular weight were produced from the plastein reaction.

• The Korean Journal of Food And Nutrition
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• v.11 no.6
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• pp.683-688
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• 1998

This study was conducted to develop optimal composition of flour brew in order to economically utilize flour brew inoculated by lactic acid bacteria as a starter(mother sponge) in bread-making. Two flour brews were prepared ; one with flour and water, the other with flour, water and NaCl. Various nutrients were added to both flour brews and Lactobacilli deMan Rogosa and Sharpe (MRS) broth to investigate the effect of them on growth and activities of Streptococcus thermophilus, Lactobacillus brevis and their mixed culture in flour brews to be tested with incubation at 37$^{\circ}C$. The growth of Streptococcus thermophilus, Lactobacillus brevis and their mixed culture was stimulated by addition of NaCl with 0.85% concentratin and more by mixed culture than by single lactic acid bacteria, resulting in 3 hrs reduction in cultivation and more by mixed culture than by single lactic acid bacteria, resulting in 3 hrs reduction in cultivation time. the addition of 3% glucose to flour brew with NaCl was observed to enhance acid productioni by mixed culture. Yeast extract greatly affected growth and activities of mixed culture of lactic acid bacteria in flour brew with NaCl and its optimum level of this additive in flour brew with NaCl was approximately 1.0%. The optimal composition of flour brew for mixed culture of lactic acid bacteria was suggested as follows; flour 100g, water 300g, NaCl 3.46g, glucose 12.48g, yeast extract 3.46g.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.3
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• pp.216-221
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• 1993

This study was carried out to determine the concentration of gaseous nitrate$(HNO_3)$ particulate nitrate$(NO_3^-)$ and conversion rate of NOx to nitrate in atmosphere in Seoul from Oct 1991 to July 1992. The average concentration of gaseous nitrate in daytime(09:00 - 17:00) was 9.93, 3.37, 7.40 and 10.40$\mug/m^3$ and, in highttime was 6.21, 7.31, 4.79 and 3.86$\mug/m^3$ respectively. The concentratin of $HNO_3$ was greater in summer and daytime than winter and nighttime. But the concentration of $NO_3^-$ was greater in winter and nighttime than in summer and daytime. The average conversion rate of NOx to $HNO_3$(Fn) indaytime was 13.18, 3.78, 9.13 and 23.13% and, in nighttime was 3.06, 1.37, 1.70 and 8.72% during fall, winter, spring and summer respectively. But the average conversion rate of NOx to $NO_3^-$(Fn') in daytime was 5.79, 5.77, 2.63 and 3.90% and in nighttime was 5.95, 6.51, 3.25 and 4.84% respectively. The average conversion rate of NOx to total nitrate $(HNO_3 + NO_3^-)$(Fn') was 12.72, 7.81, 7.82 and 18.40% respectively. The average conversion rate of NOx to $HNO_3$(Fn) was greater than $NO_3^-$(Fn') about 1.6 times.

• Journal of Nutrition and Health
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• v.29 no.8
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• pp.861-866
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• 1996

Tannins in plant foods and beverages may produce antinutritional or toxic effects although some proteins with high affinity for tannins seem to function as defense mechanism to tannin toxicity. Our objectives were to investigate of tea tannins, iron and protein and to evaluate the role of proteins in tannin effects on iron solubility. Iron solubility in vitro was measured using tea with and without proteins. Mixtures of tea, protein in varying concentrations(either gelatin or bovine serum albumin), and iron(eithe 10 or 50ug/mL) were prepared. Controls contained water in place of tea. Iron bioavailability was assessed by measuring iron solubility in the simulated gastric condition with pepsin digestion. Bound iron was removed by centrifugation and soluble in tea alone. When iron concentratin was 10ug/mL, addition of small amounts of protein to tea dramatically reduced iron solubility, but solubility of iron increased in the tea mixturea as the concentration of protein was increased. The percnetage of iron that precipitated was much greater at 10ug Fe/mL than the values at 50ug Fe/mL suggesting that the iron binding sites on the tea-protein complex was saturated. These results suggest that interactions of iron with tea tannins are influenced by the concentratins of protein and iron.