• Food Science and Preservation
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• v.21 no.2
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• pp.157-162
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• 2014

To enhance the commercialization of fresh cut kimchi cabbage, the short-term storage effect of cut kimchi cabbage treated with $Ca^{2+}$ was studied. Cut kimchi cabbages ($3{\times}3$ cm) were treated with 2% calcium chloride (Ca), ascorbic acid (As), citric acid (Ct), and calcium chloride and citric acid (Ca/Ct), were put inside LDPE bags, and stored at $5^{\circ}C$ for 6 weeks. The weights reduced about 0.13~0.72%, and the ratio was the lowest in the Ca/Ct treatment. The reduction ratios of soluble soilds were 18.85~35.00%, and were the lowest in the Ca/Ct treatment. The titratable acidity decreased in all the treatments. The L values decreased, but a and b values of Hunter colorimeter increased in all the treatments. The preference for Ca/Ct treatment was the highest among all the treatments in the sensory evaluation. The marketing shelf-life of cut kimchi cabbage can be prolonged by the combination treatment of $Ca^{2+}$ and citric acid.

• Food Science and Preservation
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• v.22 no.5
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• pp.623-628
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• 2015

Fresh cut vegetables provide convenience and rapidity to consumers. However, they have a weakness with respect to their short shelf-life due to browning and quality degradation via increased respiration. To overcome this problem, the effect of packaging film on the short-term storage of cut kimchi cabbages was investigated. Polypropylene (PP), oriented polypropylene (OPP), and low-density polyethylene (LDPE) films were used as packaging film, and cut kimchi cabbages were stored in the packaging films at $5^{\circ}C$ for 4 weeks. PP film packaging showed the least weight loss and soluble solids loss after 4 weeks. Titratable acidity increased during storage for all samples, however, the increase rate of titratable acidity in PP and OPP film packaging decreased, which was lower than that of LDPE film packaging. Color values decreased over time during storage. In appearance, PP film packaging was better than other films due to their high transparency. In a sensory test, there was no statistical difference among samples. Taken together, the transparent PP film packaging was more effective for short-term storage of cut kimchi cabbages. Thus, this study provides useful information for the selection of packaging materials for cut kimchi cabbage marketing.

• Journal of Sericultural and Entomological Science
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• v.23 no.2
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• pp.37-49
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• 1982

Larvae of the silkworm (Bombyx mori L.) were reared during the 5th instar on the four kinds of artificial diets on the basis of the different amounts of soybean meal used as the protein source. In this experiment it was shown that the various levels of protein in the diet affected not only the growth and silk production but the digestibility of the diet. haemolymph protein and uric acid excretion. The results obtained are summarized as follows; 1. By an increase of the level of protein in the diet the apparant digestibility was increased. but the protein digestibility was comparatively decreased. 2. Larval body weight increment was not observed by the 3rd day of the 5th instar, but was increased from the 4th day as the level of protein was increased in the diet. 3. After the 3rd day of the 5th instar, protein content in the hemolymph was increased steeply by an increase of the protein content in the diet. However, the percentage of hemolymph protein to the ingested protein was decreased from the 2nd day of the 5th instar and increased more or less after the 4th day. 4. An increase of the uric acid excretion was observed as the content of protein in the diet was increased but the pattern of the uric acid excretion was different between high and low-protein diet. However, the percentage of the uric acid excretion to the ingested protein and to the hemolymph protein were both decreased steeply after the 2nd day of the 5th instar. 5. It was also evident that the high-protein diet increased the cocoon productivity. 6. It showed that the feed efficiency for body weight increment and silk formation was high by an increase of the level of protein in the diet, but the protein efficiency was not.

• Journal of the Korean Wood Science and Technology
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• v.42 no.4
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• pp.407-419
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• 2014

The analysis of shape before and after heating, Surface moisture content, Moisture weight change and surface heat distribution by fixed type microwave heating in forms of flat veneer and veneer roll of Korean pine, pitch pine, larch and yellow poplar was conducted. The results were as follows: In case of flat veneer, the quality after microwave heating was comparatively good, but it was somewhat warped. These phenomena may be due to transformation by nonuniform drying stress and stronger effect of local irradiation on the veneers when heating veneer owing to the characteristics of fixed type microwave equipment. In case of the features of roll-shaped veneer heated by microwave, the quality after heating was comprehensively excellent. Especially there was no warping unlike flat veneer. Heat distribution and diffusion were also very stable for roll-shaped veneer and such heat distribution had much influence on surface moisture content and moisture weight loss. Accordingly, the veneer roll would show sufficient drying efficiency in fixed type microwave equipment through a scrutinized examination on generating power and irradiation time according to species and thickness of veneer.

• Food Science and Preservation
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• v.5 no.3
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• pp.224-230
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• 1998

In order to establish proper storage conditions for ginger, the quality changes of gingers stored at three different temperatures(7$^{\circ}C$, 12$^{\circ}C$ and 20$^{\circ}C$) and three different relative humidities(75%, 85% and 95%RH) were investigated during 150 days of storage. Gingers stored at 7$^{\circ}C$ and 20$^{\circ}C$ showed rapid quality deterioration due to chilling injury and spouting respectively in any range of relative humidity. Ginger stored at 7$^{\circ}C$ was staled to show symptoms of the chilling injury such as moldiness, shrivelling, discoloration etc after 30 days of storage ; then it was deteriorated after 90 days of storage. Ginger stored at 20$^{\circ}C$ was completely lost its storage-life after 30 days of storage because of high sprouting ratio. However ginger stored at 12$^{\circ}C$, 75%RH showed better quality than ones stored at both 7$^{\circ}C$ and 20$^{\circ}C$, but it was not so good as the one at 7$^{\circ}C$, 95%RH. Consequently storage conditions of 12$^{\circ}C$, 95%RH was observed the best effecive condition for keeping rhizomes in good quality from weight loss, spouting, mouldiness and so on.

• Journal of the Korean Ceramic Society
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• v.42 no.3 s.274
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• pp.182-187
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• 2005

There are many kinds of polycarboxylate superplasticizer as a functional classification which are introduced to domestic; Water Reducer, Retention, Ultra High Strength Superplasicizer. These are showed different physical behaviors because of the difference in the chemical system and the manners after cement mixing. In the case of water reducer, when $1.2\% of cement weight used, water reducing which is over $30\% is observed, but it take with segregation and the reduction of slump flow shows over 30 cm after 45 min of concrete produce. In the case of retention, when the same quantity used, water reducing which is about $25\% is observed and slump flow which is up to 45 min shows under 15 cm. And in the case of ultra high strength, when $1.2\% of cement weight used, water reducing which is over $30\% is observed, and slump flow which is up to 45 min recorded fewer than 15 cm. Compressive strength of ultra high strength superplasticizer has take effect of early age strength, and in the condition of specific mixing, 18 h-compressive strength is insured for more than $60\;Kgf/cm^2$ and 24 h-compressive strength is insured for more than $80\;Kgf/cm^2$.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.3
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• pp.87-98
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• 1990

The present Study dealt with the earthquake-resistant design of cantilever retaining walls supporting cohesionless soils. With design examples of three different types of cantilever retaining walls, the factors of safety against sliding were computed at various values of horizontal acceleration coefficient and compared with each other. The horizontal inertia effect due to the weights of concrete wall itself and a portion of backfill was taken into account in the analyses, and also Mononobe-Okabe pseudo-static solution method was modified to deal with various states different from limiting equilibrium state. From the analyses of safety against sliding, it was found that a cantilever retaining wall with sloped base was the most efficient type in earthquake resistant design. It was also found that by sloping the base, the width of the base slab could be reduced, resulting in the least volume of concrete, excavation and backfill as compared to the other types of walls. In the case of a cantilever retaining wall with sloped feel, the efficiency similar to that of a wall with sloped base could be expected under static loading as well as at relatively low level of earthquake loading. However, this efficiency became vanished with the increase of horizontal acceleration coefficient, since the rate of reduction in developed earth pressures on the heel became smaller. In addition, the design charts with different soil friction angles as well as with different earthquake resistant design criteria of safety factor against sliding were presented for the design of cantilever retaining walls sith sloped base.

• Journal of Korea Foresty Energy
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• v.20 no.1
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• pp.6-11
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• 2001

In order to use bast fibers of mulberry tree at a pulp source of Hanji, the bast fibers were microbiologically treated with several wood rot fungi, and the microscopic characteristics of bast fibers depending on treatment days were evaluated. By wood rot fungi, Phanerochaete chrysosporium and Trametes versicolor, the weight reduction ratio was approximately 50 percent within incubation for 20 days. occurring together with decomposition of useful fibers. However, Hwterobasidion insularis and Stereum hirsutum have completely decomposed the utmost layer of black blue colored bast fibers, and not caused the damage if fibers. Until incubation for 10 days, the cellulose content of vast fibers by Stereum hirsutum was 78.9 percent with lignin content of 7.2 percent, showing an appropriate decomposition for useful fibers. By microscopic observation, the bundled fibers were separated to single fiber within treatement days 30 by Pleurotus ostreatus, and there were no damage on the surface of fiber by treatment days 50.

• Journal of the Korean Wood Science and Technology
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• v.34 no.3
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• pp.8-14
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• 2006

The object of this study was to investigate the carbonization of Quercus variabilis wood samples in pyrolysis system at temperature ranging from 250 to $740^{\circ}C$ to contribute to the knowledge of wood carbonization mechanism. Volume of wood sample decreased with increasing the carbonization temperature, and checks were developed along with radial direction. Weight loss increased with increasing carbonization temperature. During carbonization, tangential direction showed higher shrinkage of vessel diameter than radial direction. SEM observation indicated that the cell walls in wood fibers and parenchyma cells presented the layering structure at $250^{\circ}C$ and $300^{\circ}C$. However, the cross section of cell walls at $340^{\circ}C$ and over showed an amorphous- like structure without cell wall layering. X-ray diffraction presented that the cellulose crystalline substance was still remained in carbonization temperature at $340^{\circ}C$, but it was not detected at $540^{\circ}C$ and over.

• Applied Chemistry for Engineering
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• v.5 no.6
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• pp.1068-1077
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• 1994

Blend samples of biodegradable copolyesterethylene(CPEE) with LDPE were prepared by melt-mixing through 0 to 100% per 10% interval for studying of common use of biodegradable polymer. Miscibility behavior of blend samples has been studied by observing the melting temperature change, melting enthalpy, cold crystallization temperature and crystallization enthalpy using differential scanning calorimetry. It was shown that 10~30% blend composition of CPEE had the partial miscibility from the results of thermal analysis. Valuable compatibility has been observed in all blend composition except the samples of 30~80% CPEE component from results of mechanical properties. Morphology of blends has been observed with scanning electron microscopy. Biodegrability of CPEE/LDPE blends has been evaluated by measuring the change of weight after the inoculation with specific microorganism.