• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.3
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• pp.35-39
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• 1987

The present study was attempted to obtain the basic data concerning a reasonable preparing method and the optimum fermentation conditions of Kochujang (Red pepper paste). To establish the standard qualify of Kochujang, changes of the chemical composition and the numbers of bacteria and feasts in Kochujang during fermentation were observed. Moisture, salts and crude ash contents of Kochujang were not changed significantly during fermentation. Titrable acidity and amino nitrogen gradually increased with the time-passed, whereas crude fat gradually decreased with the time-elapsed. And reducing sugar and total nitrogen increased until 40 days, but slightly decreased after this period. The numbers of bacteria and yeasts in the ingrients for the preparation of Kochujang were $3.9{\times}10^7/g$, $1.5{\times}10^3/g$ in red pepper powder, $7.6{\times}10^4/g$, $2.8{\times}10^2/g$ in salts. respectively, but those of sugar and malt were not more than 100/g. Microbial counts in Kochujang during fermentation increased until 40 days, but those are gradually decreased after that.

• Journal of the Korean Geotechnical Society
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• v.15 no.2
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• pp.43-71
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• 1999

This research is an experimental work of developing a construction material using municipal wastewater sludge as liner and cover materials for waste disposal landfill. Weathered granite soil and flyash, produced as a by-product in the power plant, were used as the primary additives to improve geotechnical engineering properties of sludge. For secondary additives, bentonite and cement were mixed with sludge to decrease the permeability and to increase the shear strength, respectively. Various laboratory test required to evaluate the design criteria for liner and cover materials, were carried out by changing the mixing ratio of sludge with the additives. Basic soil properties such as specific gravity, grain size distribution, liquid and plastic limits were measured to analyze their effects on permeability, compaction, compressibility and shear strength properties of mixtures. Laboratory compaction tests were conducted to find the maximum dry densities and the optimum moisture contents of mixtures, and their effectiveness of compaction in field was consequently evaluated. Permeability tests of variable heads with compacted samples, and the stress-controlled consolidation tests with measuring permeabilities of samples during consolidation process were performed to obtain permeability, and to find the compressibility as well as consolidational coefficients of mixtures, respectively. To evaluate the long term stability of sludges, creep tests were also conducted in parallel with permeability tests of variable heads. On the other hand, for the compacted sludge decomposed for a month, permeability tests were carried out to investigate the effect of decomposition of organic matters in sludges on its permeability. Direct shear tests were performed to evaluate the shear strength parameters of mixed sludge with weathered granite, flyash and bentonite. For the mixture of sludge with cement, unconfined compression tests were carried out to find their strength with varying mixing ratio and curing time. On the other hand, CBR tests for compacted specimen were also conducted to evaluate the trafficability of mixtures. Various test results with mixtures were assessed to evaluate whether their properties meet the requirements as liner and cover materials in waste disposal landfill.

• Food Science and Preservation
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• v.23 no.7
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• pp.931-938
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• 2016

To evaluate the effect of freezing temperature on quality characteristics of dried persimmons, dried persimmons were frozen at $-50^{\circ}C$ (quick frozen, QF) and $-20^{\circ}C$ (slow frozen, SF) for 24 hr. Frozen persimmons were then stored at -20, -10, 0 and $10^{\circ}C$ for 80 days. Total free sugar content of SF persimmons was higher than those of QF in the $+10^{\circ}C$ and $-20^{\circ}C$ stored samples. Except for samples stored at $10^{\circ}C$, the CIE $L^*$ values for QF persimmons were higher than those for SF persimmons. For samples stored at $10^{\circ}C$ and $0^{\circ}C$, the CIE $a^*$ and $b^*$ values of SF samples were higher than those for QF samples. The texture of frozen dried persimmons was investigated to determine springiness, chewiness and hardness. Chewiness and hardness of samples held at $0^{\circ}C$ were higher in SF than in QF persimmons. However, when stored at $-10^{\circ}C$, chewiness and hardness were higher in QF than in SF samples. Springiness results were similar among the QF and SF persimmons held at different storage temperatures. For all storage temperatures, QF persimmons had a high soluble tannin content. All of the sample, the average soluble tannin contents of QF is 236.09 mg%. On the other hands, those of SF is 226.87 mg%. The results indicate that freezing rate and holding temperatures have significant effects on dried persimmon texture, soluble tannin level, and free sugar content. Further studies that include sensory evaluations are needed to determine the optimum freezing rate and holding temperature for dried persimmons.

• Korean Journal of Food Science and Technology
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• v.14 no.4
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• pp.301-308
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• 1982

Chungkook-jang Koji was fermented with rice straw at $40^{\circ}C\;and\;50^{\circ}C$ for 72 hours. The changes of proximate composition, pH, titrable acidity, nitrogen compounds, protease activity and free-amino acids during the fermentation were investigated. Moisture, lipid and protein contents remained essentially unchanged during the fermentation. The pH was gradually increased from 6.4 to 7.46 and 7.82 at $40^{\circ}C\;and\;50^{\circ}C$, respectively, after 72 hour fermentation. Amino type and water soluble nitrogen increased as fermentation progressed. however, the former slightly decreased after 60 hour fermentation. Chungkook-jang fermented at $40^{\circ}C$ showed somewhat higher protease activity than $50^{\circ}C$. However, protease activity at both fermentation temperatures showed the same trend; that is, it increased until 48 hour fermentation and thereafter decrease. Free amino acid content of Chung-kook-jang after 72 hour fermentation at $40^{\circ}C$ was 6 times greater than that of the steamed soybean, while it was 2.5 times greater at $50^{\circ}C$. Based on these results. it seems that the optimum fermentation conditions for Chungkook-jang were $40^{\circ}C$ and 72 hours.

• Korean Journal of Food Science and Technology
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• v.14 no.4
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• pp.355-363
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• 1982

In order to develop the commercial storage method of potatoes by irradiation combined with natural low temperature, storage room($450{\times}650{\times}250cm$; year round temperature change, $2-17^{\circ}C;\;70-85%\;R.H.$) on a batch scale followed by irradiation with optimum dose level. Irish cobbler and Shimabara were 100% sprouted after 3 months storage in control, whereas in 15 Krad irradiated group, sprouting was completely inhibited at Irish cobbler for 9 months storage, and at Shimabara for 12 months. The extent of loss due to rot attack after 9 months storage was 6% in control, 6-8% in 10-15 Krad irradiated group at Irish cobbler and weight loss was 16.5% in control, 5.1-5.6% in irradiated group, whereas rotting rate of Shimabara after 12 months storage was 100% in control, 15% in irradiated group and the weight loss of its was 12.6% in control, $7.3{\sim}7.4%$ in irradiated group. The moisture content in whole storage period of two varieties were $72{\sim}82%$ without remarkable changes. The total sugar and ascorbic acid contents were slightly decreased according to the dose increase and elapse of storage period, whereas reducing sugar content was increased. Irish cobbler was 90% marketable after 9 months storage and 85% in Shimabara after 12 months storage.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.288-292
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• 2008

This study was conducted to identify the effects of irrigation amount to produce high quality melon fruit in fertigation culture. Irrigation amount of during fruit harvesting period was doubled at the low irrigation point ($(-45{\sim}50\;kPa$) treatment as 115 mm as than that of the high irrigation point ($-20{\sim}25\;kPa$) treatment. The plant growth rates such as stem length, leaf weight and plant height were a little diminished at the low irrigation point ($-45{\sim}50\;kPa$) than those of the other treatments. Internode length was however not affected by irrigation amount. Fruit weight was lighter at the low irrigation point ($-45{\sim}50\;kPa$) than that of at the high irrigation point and fruit height was shorter, but fruit diameter was not affected by irrigation amount. Fruit soluble solid was $0.9^{\circ}Bx$ higher at the low irrigation point ($-45{\sim}50\;kPa$) than at the high irrigation point ($-20{\sim}25\;kPa$) and net index was higher. Total marketable yield was highest by 3,937 kg/10a at the high irrigation point ($-20{\sim}25\;kPa$), but the excellent marketable yield was highest by 2,531 kg/10a at the low irrigation point ($-45{\sim}50\;kPa$). Inorganic contents of the soil N, K, Ca and Mg were not affected by irrigation amount. It was therefore thought that optimum irrigation point to produce high quality melon fruit by fertigation culture was $-45{\sim}50\;kPa$ at ripening stage.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.304-309
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• 2011

BACKGROUND: Generally, water plants may play an important role in nutrients(N, P) removal in constructed wetlands(CWs). Previous studies considered nutrients uptake by water plants in various CWs for treating point source pollution. On the other hand, few studies considered nutrients uptake by water plants in free water surface(FWS) CWs for treating non-point source pollution. METHODS AND RESULTS: To investigate characteristics of nutrient uptake by water plants in FWS CWs, dry weights, nutrients content and nutrients uptake by water plants were investigated from April, 2008 to October, 2008. Dominance plants were Phragmites japonica STEUD (PHRJA), Nymphaea tetragona ANGUSTA(NTMTE), Typha orientalis PRESL(TYHOR), Phragmites communis TRINIUS(PHRCO) and Zizanis latifolia TURCZ(ZIZLA) in FWS CWs. The dry weights of water plants in August were higher in the order of TYHOR(54.27 g/plant) > PHRJA(44.30 g/plant) ${\geqq}$ PHRCO(39.60 g/plant) ${\geqq}$ ZIZLA(37.80 g/plant) ${\fallingdotseq}$ NTMTE(36.75 g/plant). The T-N and T-P contents by water plants were not significantly differences regardless of cultivation period. The maximum amount of T-N uptake by water plants in August were 773 mg/plant for PHRJA, 625 mg/plant for NTMTE, 1206 mg/plant for TYHOR, 754 mg/plant for PHRCO and 768 mg/plant for ZIZLA. The maximum amounts of T-P uptake by PHRJA, NTMTE, TYHOR, PHRCO and ZIZLA were 397, 177, 411, 261 and 229 mg/plant in August, respectively. CONCLUSION(s): The results of this study suggest that optimum water plant was Typha orientalis PRESL in free water surface constructed wetlands.

• Korean Journal of Materials Research
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• v.9 no.3
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• pp.274-281
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• 1999

Usually sputtering and electroless plating methods were used for manufacturing metal-alloy thin film magnetic memory devices. Since electroless plating method has many merits in mass production and product variety com­pared to sputtering method, many researches about electroless plating have been performed in the United State of America and Japan. However, electroless plating method has not been studied frequently in Korea. In these respects the purpose of this research is manufacturing Co-Mn-P alloy thin film on the corning glass 2948 by electroless plating method using sodium hypophosphite as a reductant, and analyzing deposition rate, alloy composition, microstructure, and magnetic characteristics at various pH's and temperatures. For Co-P alloy thin film, the reductive deposition reaction 0$\alpha$urred only in basic condition, not in acidic condition. The deposition rate increased as the pH and temperature increased, and the optimum condition was found at the pH of 10 and the temperature of $80^{\circ}C$. Also magnetic charac­teristics was found to be most excellent at the pH of 9 and the temperature of $70^{\circ}C$, resulting in the coercive force of 8700e and the squareness of 0.78. At this condition, the contents of P was 2.54% and the thickness of the film was $0.216\mu\textrm{m}$. For crystal orientation, we could not observe fcc for $\beta$-Co. On the other hand,(1010), (0002), (1011) orientation of hcp for a-Co was observed. We could confirm the formation of longitudinal magnetization from dominant (1010) and (1011) orientation of Co-P alloy. For Co-Mn-P alloy deposition, coercive force was about 1000e more than that of Co P alloy, but squareness had no difference. For crystal orientation, (l01O) and (lOll) orientation of $\alpha$-Co was dominant as same as that of Co- P alloy. Likewise we could confirm the formation of longitudinal magnetization.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.687-696
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• 2015

Black mini tomato 'Hei-G' fruits were harvested at different stages of maturity (immature-mature green and mature-black red) and stored at different temperatures (8, 12, and $20^{\circ}C$) to investigate the quality and lycopene content during storage. Weight loss increased dramatically at higher temperature for both harvesting stages without significant differences. Firmness of immature fruits decreased below the initial level of mature fruit (8.1N) after 5, 8, and 19 days storage, when they were stored at 20, 12, and $8^{\circ}C$, respectively. Soluble solid contents of mature fruit increased at initial storage, and were higher as compared to immature fruits before deterioration at each storage temperature. Decrease in titratable acid of mature fruits depended on storage time and temperature. However, titratable acid of immature fruits showed little change during storage, and so it did not affect flavor. Hunter a value changed greatly in immature fruit stored at high temperature. Unlike ripe tomatoes, there was no significant difference in black tomato Hunter b values of immature and mature fruit at initial and 12 days storage. However, immature fruits stored at $8^{\circ}C$ did not reach full maturity and color development and ripening. High storage temperature increased lycopene production while low storage temperature blocked lycopene development. Shelf life of the immature fruits, which was evaluated by elapsed days to conventional mature stage, was 12 and 15 days when they were stored at 20 and $12^{\circ}C$, respectively. The optimum storage temperature to maintain the quality and lycopene content of mature fruits was $12^{\circ}C$. Moreover, the shelf life of mature fruits stored at $20^{\circ}C$ could reach up to 5 days.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.4
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• pp.359-365
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• 1985

The four rice varieties, Kwanak, Nongbaek, Pungsan and Nampung-byo were cultivated to examine the growth conditions and grain yield in a Gyuam SiL paddy field irrigated with cold water around $17^{\circ}C$. Water temperatures for various distances from the inlet were measured. The results were summerized as follows. 1. Culm length, panicle exertion, diameter of the 3rd internode stem, heading date, fertilization rate, ripeness rate, no. of grains per panicle and grain yield were sensitive to water temperature. Panicle length, flag-leaf length, diameter of spike-neck and no. of panicles, however, were negligibly sensitive and there were no differences among varieties. 2. Elongations of the 2nd and 3rd internode steam were unsensitive to water temperature. 1st internode elongation and 4th internode development, however, were sensitive which was major factor in the culm length. 3. Ratios of partial dry weight to total dry weight were closely correlated with water temperature, Therefore, dry weight of grain was increased with water temperature while that of plant and root decreased. 4. Chlorophyll contents were decreased with the increment of water temperature and the highest at $20^{\circ}C$. 5. There was no grain yield at $17^{\circ}C$, Increases of grain yield to water temperature per unit were order at Pungsan > Kwanak > Nongbaek > Nampung. 6. The critical temperature in grain yield was $21^{\circ}C$. Optimum temperatures of Japonica ${\times}$ Indica types were higher than those of Japonica types.