• 한국환경보건학회지
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• 제22권4호
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• pp.82-90
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• 1996

This study was performed to find the optimum mixing ratio of paper waste in composting of mixture of swine feces and newspaper. Using the experimental setting of aeration rate which was found in the experiment carried out priorly, and moisture contents reported in other literature, just the initial C:N ratios were differentiated by mixing different amount of newspaper with the same amount of swine feces. This study was carried out by operating 4 experimental cornposting reactors of bench scale for 3 weeks. The followings are the conclusions that were derived from this study. 1. During composting reaction, the C:N ratio of each cornposter was decreased. Degree of decrease was in order of run 3, run 2, run 4, and run 1 of which initial C:N ratio was 30, 25, 35, and 20 respectively. All of the final composts were found to be completed composting reaction. 2. Ash contents of each reactor increased rapidly in order of run 3, run 2, run 4, and run 1. The absolute values of quadratic effect coefficients of each second order regression function was 0.059, 0.038, 0.032, and 0.030 respectively. Ash contents evolution trend had a linear correlation with the C:N ratio trend. (r=-0.96932, p<0.05) 3. The range of highest temperatures reached during composting was 47.2-53.5$\circ$C. Those were not significantly different from one another. Thermophilic temperatures were maintained in the range of 48-108 hours. 4. Contents of heavy metal detected in the final compost were lower than those of Korean and European standards. 5. Concentration range of Nitrogen in the final compost was 1.11-2.27%, and that of phosphorus was 8.40-10.70 mg/kg. 6. The optimum C:N ratio which has been proposed without the consideration of types of bulking agents should be re-examined. Biodegradabilities of each bulking agents was thought to be important factor when determining the optimum initial C:N ratio for cornposting.

• 한국가금학회지
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• 제12권1호
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• pp.39-44
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• 1985

본 조사연구는 계란의 중량등급별 영양가를 조사하고 적정가격을 검토하기 위하여 600개의 계란을 공시하여 계란의 중량등급별 평균란중, 란황과 란백 및 란각의 구성비, 란황과 란백의 영양성분 분석, 계란의 단백질과 지방함량 조사를 실시하고, 계란의 란중과 단백질함량 및 단백질＋지방함량을 기준으로 하는 적정가격을 검토하였는 바 얻어진 결과는 다음과 같다. 1. 평균란중(X, g/10개)의 증가에 따라 란황의 비율(Y, %)은 Y=44.34-0.02X로 감소하고, 란백의 비율(Y, %)은 Y=40.136＋0.026X로 증가하였으며, 란각의 비율(Y, %)은 Y=15.358-0.006X로 감소하였다. 2. 란황과 란백의 영양분석은 계란의 중량에 따라 큰 차이나 일정한 경향을 보이지 않았다. 3. 평균란중(X, g/10개)의 증가에 따라 전란의 단백질함량(Y, %)은 Y=11.943-0.00032X로 감소하고, 지방함량(Y, %)은 Y=13.996-0.00614X로 역시 감소하였으며, 단백질＋지방함량(Y, %)는 Y=25.939-0.00646X로 감소하였다. 4. 평균란중을 기준으로 하는 적정가는 단백질함량을 기준으로 하는 적정가와 비슷한 경향을 보였으며, 이들 적정가는 단백질＋지방함량을 기준으로 하는 적정가보다 특란과 왕란에서는 높게 그리고 경란-중란에서는 낮게 평가되었으며, 시가와 비교할 때 단백질＋지방함량기준 적정가가 가장 비슷한 경향을 보였다.

• 한국식품영양과학회지
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• 제23권4호
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• pp.618-624
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• 1994

The addition of mustard leaf to kimchi making for extanding the optimum edible period was studied. The quality and sensory characteristics of mustard leaf added kimchi were evaluated . The activity, lactic and acetic acid contents of mustard leaf added kimchi showed lower than that of control kimchi but reducing sugar and vitamin C contents was higher. The duration of optimum edible periods of mustard leaf added kimchi lasted one more weak. While the optimum pH of kimchi for eating lasted, the sensory pannel score for sour taste of mustard leaf added kimchi was lower than that of control but the scoreas for savory taste, carbonated taste and hardness were higher . Especially , the sour taste score between two groups were significantly different (p<0.05). Overall quality score for the mustard leaf added kimchi was higher. There was no differences in texture determined by Penetrometer between mustard leaf added kimchi and control kimchi until the fermentation reached the optimal condition for eating . After that period , the degree of degradation of texture was much delayed in mustard leaf added kimchi.

• 동아시아식생활학회지
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• 제21권5호
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• pp.661-668
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• 2011

This study was conducted in order to determine the optimum conditions for the production of fermented grapefruit extract showing high cell growth, antioxidant activity and total flavonoid content. Five lactic acid bacterial strains - Lactobacillus plantarum KCTC3104, Lactobacillus brevis KCTC3102, Weisella cibaria KCTC3746, Leuconostoc citreum KCTC3526 and Leuconostoc mesenteroides KCTC3505 - were evaluated first in order to determine the optimum strain able to grow with high efficiency on grapefruit as a substrate and possesses higher antioxidant activity and flavonoids content. Among these strains, L. mesenteroides KCTC3505 was selected as a starter culture. To estimate the available or effective content of grapefruit in basal medium, the effects of 30%, 50%, and 70% grapefruit contents on the performance of fermentation were tested, and it was found that grapefruit can be added at 70% levels to medium. In this study, three factors of fermentation conditions - incubation time, sucrose, and glucose contents - were evaluated for their effects on fermentation performance. Taguchi experiment design was employed and the responses of experiments were calculated using signal and noise ratio calculation with larger-the-best characteristics. Finally, the optimum conditions for the manufacture of fermented grapefruit extract were as follows: grapefruit 70%, sucrose 10 g/L, glucose 10 g/L, sodium acetate 1 g/L, NaCl 1 g/L, dipotassium phosphate 0.1 g/L, magnesium sulfate 0.01 g/L and 16 hr of incubation.

• 한국농공학회지
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• 제17권1호
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• pp.3685-3701
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• 1975

This study was conducted to investigate the strength of soil cements for varied molding water content and cement content(3,6,9,12%) in four cementstabilized soils(KY: sand, MH: sad, SS: sandy loam, JJ: loam). The eoperimental results obtainedfrom unconfined compressive strength tests are asfollows: 1. The optimum moisture content increased in accordance with the increase of the cement while maximum dry density didn't change uniformly. 2. The moisture content for maximum strength was higher than the optimum moisture content in the higher cement content. Moisture-density curves showed a dull peak in the higher cement contents, on the other hand, a sharp peak in the lower cement contents. 3. In molding the specimen with the approximate optimum moisture content, the maximum strength showed at the wet side of the optimum moisture content. 4. SS and JJ maybe used as cement-stabilized base of road to require 300PSI of compressive strength cured seven days, but MH and KY may be not adequate. 5. In soil cement, the better the grain size distribution was, the stronger the compressive strength was itn general. 6. The relation between 28-day strengh and 7-day strength in the cementstabilized four soils may be expressed as follows: q28=1.55q7+1.5 in which q28:28-day strength. q7:7-day strength.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.1113-1116
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• 2002

For contents delivery systems, the service is considered in which the utility depends on each priority class. This paper deals with the multiple priority class of the contents delivery system from the viewpoint of the utility. The willingness to pay (WTP) is introduced as a measure of utility, and the optimum condition is analyzed to maximize the total user's utility. For the system with multiple priority classes, the optimum condition is given in terms of the traffic load, wating time for service for each priority class. Systems with the priority classes, 1, 2 and 3 are analyzed, and the effect of the number of priority classes is examined.

• 한국연초학회지
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• 제5권1호
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• pp.25-33
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• 1983

This study was carried out to investigate the transplanting time, optimum fertilization and harvesting method, chemical contents and physical properties of burley tobacco in paddy field. The results obtained as follows. 1. It is recommendable to transplant after March. 29 to escape the frost injury. By reducing compound fertilizer and whole plant stalk curing, advanced the. last priming date by 5-8 days. 2. Total alkaloid, total nitrogen and phosphorus contents of cured leaf was comparable to those of upland-produce(1 tobacco, but potassium and chloride contents some what high. 3. Filling power and combustibility was also comparable to upland, and filling power was increased by reducing fertilizer and whole plant stalk curing. 4. In the 20o reducing fertilizer-5 Primings volt. the yield was some what decreased, but visual quality and value per 10a were high. 5. The total raw income of tobacco and rice cropping was increased 124~170% than that of rice cropping.

• Fibers and Polymers
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• 제6권1호
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• pp.13-18
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• 2005

PLA/LPCL/HPCL blend fibers composed of poly (lactic acid) (PLA), low molecular weight poly ($\varepsilon$-caprolactone) (LPCL), and high molecular weight poly ($\varepsilon$-caprolactone) (HPCL) were prepared by melt blending and spinning for bioab­sorbable filament sutures. The effects of blending time and blend composition on the X-ray diffraction patterns and tensile properties of PLA/LPCL/HPCL blend fibers were characterized by WAXD and UTM. In addition, the effect of in vitro degra­dation on the weight loss and tensile properties of the blend fibers hydrolyzed during immersion in a phosphate buffer solu­tion at pH 7.4 and 37$^{\circ}C$ for 1-8 weeks was investigated. The peak intensities of PLA/LPCL/HPCL blend fibers in X-ray diffraction patterns decreased with an increase of blending time and LPCL contents in the blend fibers. The weight loss of PLA/LPCL/HPCL blend fibers increased with an increase of blending time, LPCL contents, and hydrolysis time while the tensile strength and modulus of the blend fibers decreased. The tensile strength and modulus of the blend fibers were also found to be increased with an increase of HPCL contents in the blend fibers. The optimum conditions to prepare PLA/LPCL/HPCL blend fibers for bioabsorbable sutures are LPCL contents of $5 wt\%, HPCL contents of $35 wt\%, and blending time of 30 min. The strength retention of the PLA/LPCL/HPCL blend fiber prepared under optimum conditions was about $93.5\% even at hydrolysis time of 2 weeks.

• 한국농공학회지
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• 제40권4호
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• pp.109-119
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• 1998

Recently pipe-framed greenhouses are widely constructed on domestic farm area. These greenhouses are extremely light-weighted structures and so are easily damaged under strong wind due to the lack of uplift resistance of foundation piles. This experiment was carried out by laboratory soil tank to investigate the displacement be haviors of cylindrical pile foundations according to the uplift loads. Tested soils were sampled from two different greenhouse areas. The treatment for each soil type are consisted of 3 different soil moisture conditions, 2 different soil depths, and 3 different soil compaction ratios. Each test was designed to be repeated 2 times and additional tests were carried out when needed. The results are summarized as follows : 1. When the soil moisture content are low and/or pile foundations are buried relatively shallow, ultimate uplift capacity of foundation soil was generated just after begining of uplift displacement. But under the high moisture conditions and/or deeply buried depth, ultimate up-lift capacity of foundation soil was generated before the begining of uplift displacement. 2. For the case of soil S$_1$, the ultimate uplift capacity of piles depending on moisture contents was found to be highest in optimum moisture condition and in the order of air dryed and saturated moisture contents. But for the case of soil S$_2$, the ultimate uplift capacity was found to be highest in optimum moisture condition and in the order of saturated and air dryed moisture contents. 3. Ultimate uplift capacities are varied depending on the pile foundation soil moisture conditions. Under the conditions of optimum soil moisture contents with 60cm soil depth, the ultimate uplift capacity of pile foundation in compaction ratio of 80%, 85%, and 90% for soil 51 are 76kg, 115kg, and 155kg, respectively, and for soil S$_2$are 36kg, 60kg, and 92kg, respectively. But considering that typical greenhouse uplift failure be occurred under saturnted soil moisture content which prevails during high wind storm accompanying heavy rain, pile foundation is required to be designed under the soil condition of saturated moisture content. 4. Approximated safe wind velosities estimated for soil sample S$_1$and S$_2$are 32.92m/s and 26.58m/s respectively under the optimum soil condition of 90% compaction ratio and optimum moisture content. But considering the uplift failure pattern under saturated moisture contents which are typical situations of high wind accompanying heavy rain, the safe wind velosities for soil sample S$_1$and S$_2$are not any higher than 20.33m/s and 22.69m/s respectively.

• 동아시아식생활학회지
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• 제4권3호
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• pp.147-169
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• 1994

This study was conducted to ivestigate the quality of modeled chinese-cabbage Kimchi. The mutual action of sub-ingredients and optimum mixing conditions were examined by analyses of pH, acidity, content of vitamins, carotenes, number of total microorganism, and Lactobacilli, the activities of softening related to enzymes (polygalacturonase and ${\beta}$-galactosidase), and sensory quality during fermentation. The result about the mutual action of red pepler powder and garlic showed that the pH was decresed as concentration of garlic was higher and that of red peppler powder became lower. Kimchi had unpleasant taste and undesirable odor when the adding ratio of the peper powder and garlic was unbalanced. As the concentration of garlic became higher, the content of vitamin C in Kimchi tissue decreased while that of vitamin C in Kimchi juice increased. The contents of vitamin B1, B2 and carotene increased as the concentration of garlic became lower. The optimum mixing ratio of red pepper powder and garlic evaluated by overall eating quality was 4.66% and 3.45%, respectively. The result about the mutual action of ginger and green onion was that pH became higher as the concentration of ginger was 1.84% and that of green onion was 5.96%. The intensity of fresh taste and odor became stronger as the concentration of ginger increaed to 2.76% and that of green onion decreased to 2.98%. The balance of sour, salty and hot taste became better as the concentration of ginger increased and that of green onion decreased. The optimum mixing condition evaluated by overall eating quality was 2.94% in ginger ＋ 2.78% in green onion. The contents of vitamin B1, B2 and C were high in this condition. The result about the mutual action of leek and salted anchovy juice was that pH became lower as the concentration of leek increased and that of salted anchovy juice decreased. Sour, hot and sweet tastes were good in the condition of leek 12%, salted anchovy juice 4.69%. Palatable, fresh taste and odor became weaker when the one of both sub-ingredients was too much little. The optimum mixing condition evaluated by overall easting quality was 9.76% in leek ＋ 7.32% in salted anchovy juice. The contents of vitamin B1, B2, C and carotene were high in this condition and other sensory qualities were good. The result about the mutual action of salt and sugar was that pH became lower as the concentration of sugar became higher and that of salt became lower. The sweet taste was reduced of hot taste than salty taste. Palatable and fresh tastes were desirable when Kimchi fermented with less salt and more sugar. The optimum mixing condition evaluated by overall eating quality was 3.29% in sugar ＋ 4.80% in salt. The contents of vitamin B1, B1, C and carotene were high in this condition. The result of model Kimchi fermented at 20$^{\circ}C$ was that the number of Lactobacilli in model Kimchi was higher than that of in control Kimchi. The fermentation period was extended under pH 4.0 and the contents of vitamin B1, B1,C and carotene were high through the whole edible period. The activity of polygalacturonase was low, but that of ${\beta}$-galactosidase was high during fermentation.