• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.412-420
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• 2005

In order to investigate factors affecting the denitrification in the F-STEP PROCESS using a loess ball as support media and Pseudomonas DWC 17-8, calcining temperature, loess ball size, pH, nitrate concentration, working temperature, and inhibitor were studied in batch mode using synthetic sludge. A 5- 10 mm of loess ball (960$^{circ}$ of calcining temperature) was the most suitable for denitrification. When the initial pH was increased from 3.0 to 7.0, the removal efficiency of nitrate was increased. Specifically, at initial pH of 7.0, the maximum removal efficiency of nitrate was 5.0 mg/min. When the initial concentration of nitrate was increased from 100 to 400 mg/l, the removal efficiency of nitrate was proportional to the concentration of nitrate. The maximum removal efficiency of nitrate was 5.72 mg/min at 400 mg/l of initial concentration. When the operating temperature was increased from 10 to 30$^{circ}$, the removal efficiency of nitrate was increased from 0.76 to 6.15 mg/min, and at above 40$^{circ}$ of operating temperature, it was decreased from 4.0 to 2.0 mg/min. Among the various inhibitors, higher than 10$^{-1}$ M of sodium azide abolished this reaction completely. When the KCN concentration was above 10$^{-1}$ M, the reaction was inhibited completely. In the case of 2,4-dinitrophenol and sodium sulphide, it was inhibited at above 10$^{-2}$ M completely. For testing the various flow orders of the F-STEP PROCESS for effective denitrification using practical wastewater, continuous experiments under the optimum conditions were carried out for 60 days. Among the various processes, the PROCESS A gave the highest efficiencies of denitrification, nitrification, and total nitrogen (TN) removal with 86.5, 89.5, and $90\%$, respectively. For scale-up in the PROCESS A, real farm wastewater was used and pilot tests carried out for 90 days. The denitrification efficiency was $97.5\%$, which was increased by $12.7\%$. The efficiencies of TN removal and nitrification were 96.6 and $70.0\%$, respectively. The removal efficiency of chemical oxygen demand (COD) was $63.7\%$, which was increased by $20\%$.

• Food Science and Biotechnology
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• 제16권6호
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• pp.928-934
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• 2007

Physiochemical properties, such as yield and molecular weight distribution of polysaccharide fractions, of polysaccharides in the enzymatic hydrolysates of purslane were investigated and characterized. A higher amount of micro nutrients, such as potassium (9,413 mg/100 g), phosphorus acid (539 mg/100 g), leucine, alanine, lysine, valine, glycine, and isoleucine, was present in whole purslane. The yield of water soluble polysaccharides (WSP) was 0.29, 7.01, and 7.94% when extracted using room temperature water (RTW), hot-water (HW), and hot temperature/high pressure-water (HTPW), respectively, indicating that HW or HTPW extraction may be effective to obtain WSP from purslane. The average ratio of L-arabinose:D-galactose in the WSP was 37:49, 34:37, and 27:29, when extracted using RTW, HW, and HTPW, respectively. These results indicate that water was a suitable extraction solvent for preparation of the arabinogalactan component of whole purslane. A higher yield and total carbohydrate content was obtained by using Viscozyme L instead of Pectinex 5XL during extraction of the WSP, which indicates that enzymatic treatment of purslane may be an effective method to control the Mw of polysaccharides. Finally, it was confirmed that Viscozyme L is a suitable enzyme for the hydrolysis and separation of polysaccharides obtained from purslane.

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 2003년도 제23차 추계총회 및 국제학술심포지움
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• pp.187-187
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• 2003

To examine the effect of packaging method on strawberry, tomato, and plum quality, the rate of weight loss, Hunter a value, decay rate, anthocyanin contents, and microbial (total bacterial counts, mold and yeast, and pseudomonas) changes were determined during storage. Strawberry was packaged with low density polyethylene (LDPE). Tomato and plum were packaged with high density polyethylene film (HDPE). Strawberries, tomatoes, and plums were then stored at 4$^{\circ}C$ and 20$^{\circ}C$, respectively. LDPE package was the most effective on the decrease of decay rate of strawberry and the rate of weight loss for packaged strawberry was lower than that of the non-packaged. HDPE package was the most effective on the rate of weight loss during storage of tomatoes and plums regardless of storage temperature. Hunter a value increased during storage. Anthocyanin contents of plums increased overall with increasing storage time, and plums stored without package were changed more than those with package. Microbial changes of strawberry, tomato, and plum stored at 4$^{\circ}C$ and 20$^{\circ}C$ were monitored during storage. Packaging method did not affect the microbial change, yet temperature did affect the microbial change significantly. These results indicate that storage of these commodities at 4$^{\circ}C$ should be recommended in terms ,of microbial safety as well as quality and shelf-life.

• 한국축산시설환경학회지
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• 제12권1호
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• pp.29-34
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• 2006

The effects of turning frequency were examined on the efficiency of composting lime treated excess sludge amended with sawdust from the activated sludge process after a liquid/solids separation process. The raw and excess sludge from the activated sludge process associated with the hog wastewater treatment system is a significant problem and composting is an effective method far reducing the pollution potential of hog wastewater sludge. The coagulant used sludge composting and ammonia emissions from composting are not well established. The effect of compost properties such as high total carbon, C/N ratio and pH value on performance of composting sludge and biofiltration of ammonia from composting process were investigated. The ammonia emission was not significantly increased during composting. The ammonia concentrations of the exhaust air of composter were ranged from 0.5 and 7 ppm about 12 days after composting. The performance of the hog wastewater sludge composting was the most sensitive to chemical treated sludge properties such as high total carbon and high C/N ratio of the initial compost mixes. Temperature in compost and ammonia emission were not greatly affected by the turning frequency.

• Tribology and Lubricants
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• 제26권1호
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• pp.73-77
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• 2010

One of the important trends for condition monitoring in the 21st century is the development of smart sensors that will permit the cost-effective continuous monitoring of key machine equipments. In this study, an integrated in-line oil monitoring sensor assigned for continuous in situ monitoring multiple parameters of oil performance is presented. The sensor estimates oil deterioration based on the information about chemical degradation, total contamination, water content of oil and oil temperature. The oil oxidation is estimated by "chromatic ratio", total contamination is measured by the changes in optical density of oil in three optical wave-bands ('Red', 'Green' and 'Blue') and water content is evaluated as relative saturation of oil by water. In order to evaluate the sensor's effectiveness, the sensor was applied to several used oil samples in steel making industry and the results were compared with those measured by standard test methods.

• 한국식품과학회지
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• 제18권2호
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• pp.168-172
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• 1986

본 연구는 홍미삼으로부터 홍삼엑기스를 제조할 때 추출용매와 온도 그리고 추출시간의 변화가 추출과정중 원료삼의 팽윤성과 흡수성 그리고 홍삼엑기스의 고형분 수율의 차이를 비교한뒤 이들의 관계를 통계적으로 분석함으로서 추출조건에 따른 이들 성질을 예측코져 하였다. 홍미삼의 팽윤율과 흡수율은 에탄올의 농도가 높을수록 현저히 감소되었으며, 온도의 상승으로 흡수율은 증가되었으나 평형시의 팽윤율에는 영향을 주지않았다. 한편 가용성 물질이 용출율은 에탄올의 농도가 높을수록 감소되어었으며 온도상승에서는 반대로 증가되었다. 또한 각 추출조건에서 추출시간에 따른 팽윤율과 흡수율 그리고 용출율은 높은 상관관계를 갖는 대수함수적 관계를 가지고 있었다. 따라서 이들의 관계식으로부터 주어진 에탄올의 농도와 추출시간에서의 이들의 성질을 예측할 수 있었다.

• Nuclear Engineering and Technology
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• 제38권3호
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• pp.301-310
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• 2006

Destructive methods were used for the burnup determination of U-Zr alloy nuclear fuel irradiated in the High-flux Advanced Neutron Application Reactor (HANARO) at KAERI. The dissolution rate of unirradiated U-Zr alloy fuel in $HNO_3$/HF mixtures was investigated for the experimental conditions of a different temperature, and initial concentrations of HF and $HNO_3$. The irradiated U-Zr alloy fuel specimen was dissolved in a mixed acid condition of 3 M HNO3 and 1 M HF at $90^{\circ}C$ for 8 hours under reflux. The total burnup was determined from measurement of the Nd isotope burnup monitors. The method includes U, Pu, $^{148}Nd,\;^P{145}Nd+^{146}Nd,\;^{144}Nd+^{143}Nd$ and total Nd isotopes determination by the isotope dilution mass spectrometric method (IDMS) using triple spikes $(^{233}U,\;^{242}Pu\;and\;^{150}Nd)$. The effective fission yield was calculated from the weighted fission yields averaged over the irradiation period. The results are compared with that obtained by the destructive -spectrometric measurement of the $^{137}Cs$ monitor.

• 한국초지조사료학회지
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• 제1권1호
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• pp.10-17
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• 1978

The experiment were carried out to determine the rate of regrowth, the changes of carbohydrates contained in the samples right after cutting, plant part for storage of carbohydtates and top-dressing time of ladino clover and orchardgrass. Plants were grown in the simple growth chamber as well as in the fields. The temperature, light intensity and light period were controlled to be 15-20$^{\circ}$, 4,250 Lux, and 15 hours in the simple growth chamber. The results obtained are as follows ; 1. The period of recovery to initial stands after cutting was about 3 weeks in ladino clover and 4-5 weeks in orchard grass in terms of dry matter and carbohydrates. 2. The content of total water-soluble carbohydrates of plant parts was the hightest in stolon of ladino clover and in sheath of orchardgrass, and the lowest in roots of ladino clover and orchardgrass. 3. Cutting resulted in a temporary decrease of total water-soluble carbohydrates in the shoots. Similar trends were observed when the plants were left intact with top-dressing. 4. The top-dressing applied simultalliousely with the cutting was more effective to stimu1ate regrowth than that applied after cutting, however, both of the simultaneous and after cutting application were still better than application prior to cutting.

• 한국미생물·생명공학회지
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• 제5권1호
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• pp.5-12
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• 1977

As a basic study for the application of the spore-tearing lactic acid bacteria to foods, the effects of the sporulating conditions on the growth and sporogenesis were studied were observed. The results obtained are as follow. 1. All carbohydrates added to sporulation media except dextrin decreased the sporulation rate and the thermal resistance of spores. Dextrin stimulated the growth, however, there in no effect on the thermal resistance. 2. As nitrogen source, the protein hydrolysates such as peptone, casamino acid were effective to obtain were spores of the increased thermal resistance. 3. Ca$\^$＋＋/, Mn$\^$＋＋/ of the metal ions added to casamino acid containing medium validly increased the total growth, sporulation rate and thermal resistance. Its optimum concentration was 40 ppm each. 4. Biotin of vitamines had an effect on the total growth, sporulation and thermal resistance of spores. Its optimum concentration was 30${\gamma}$/ml. 5. The resistant spores required the adequate maturation period, more than 36 hours, sufficient aeration. and optimum temperature, 37∼45$^{\circ}C$.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 1999년도 춘계학술발표회 초록집
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• pp.97-97
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• 1999

Dross formation in the zinc bath is inevitable under any condition as long as coating process on steel strip continues. Thus, bath aluminum and temperature are precisely managed to suppress the increase of dross. Also, excessive dross for normal coating process is generally eliminated physically by bubbling and skimming. Total amount of dross in the bath can be sometimes high enough to cause coating defect. On the other hand, local concentration of dross can make coating defect even with satisfactory level of total amount of dross. Reduction of dross in the bath was attempted by using ceramic foam filter made of mainly alumina. Dross in molten zinc was almost reduced to the levels of solubility of iron and aluminum in molten zinc at $450~460^{\circ}C$. Their solubility levels were confirmed by thermodynamic calculations or DEAL program. Two kinds of filters were tested for dross reduction. One was #20 ppi, porous per inch, and the other #30 ppi filter. Both were effective in reducing the bath dross to the solubility levels at the static state. Bath iron was reduced by 24 wt% and 19 wt% with #20 filter, and by 35 wt% and 29 wt% with #30 filter for GI and GA pot, respectively. Also, ceramic foam filter did not make any harm to the zinc bath composition after filtering test.