• Journal of The Korean Society of Agricultural Engineers
• /
• v.48 no.2
• /
• pp.13-23
• /
• 2006

In Korea, upland irrigation generally depends on the ground water or natural rainfall since irrigation water supplied from dams is mainly used for paddy irrigation, and only limited amount of irrigation water is supplied to the upland area. For the stable security of upland irrigation water, storage level of irrigation dams was simulated by the periods. A year was divided into 4 periods considering the irrigation characteristics. Through the periodical management of storage level, water utilization efficiency in irrigation dams could be enhanced and it makes available to secure extra available water from existing dams without new development of water resources. Two study areas, Seongju and Donghwa dam, were selected for this study. Runoff from the watersheds was simulated by the modified tank model and the irrigation water to upland crops was calculated by the Penman-Monteith method. The analyzed results showed that relatively sufficient extra available water could be secured for the main upland crops in Seongju area. In case of Donghwa area, water supply to non-irrigated upland was possible in normal years but extra water was necessary in drought years such as 1998 and 2001.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.1418-1423
• /
• 2009

This study describes experimental study on the performance characteristics with load condition in hybrid solar heating system during spring season. The room temperatures, the hot water conditions and the lower part temperatures of heat storage tank were changed to analyze the system performances. As a results, the hot water was significantly affected by the ambient temperature. The indoor setting temperature affected the solar fraction. When the low part temperature of the storage tank increased, the temperature of the hot water rose and the temperature of the hot water in morning was affected by the ambient temperature.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.48 no.5
• /
• pp.631-638
• /
• 2015

This study evaluated the quality characteristics of semi-dried small squid Idiosepius paradoxus treated with grapefruit Citrus paradisi seed extract (GSE) during refrigerated storage for 6 months. The moisture content and water activity decreased significantly in both control and GSE-treated groups with increasing storage time, but there was no significant difference between groups. During storage, the degree of water activity reduction was lower in the GSE-treated group than in the control. The pH change was similar in both groups during storage. The thiobarbituric acid reactive substances (TBARS) value of the GSE-treated group was lower than that of the control until 4 months of storage, and was subsequently higher than in the control group. The Hunter color L value did not differ significantly during storage between groups, whereas the a and b values decreased significantly (P<0.05) in both groups with increasing storage time. The hardness value of the semi-dried small squid increased with storage time, but there was no statistical difference between GSE treatment and control. There were more viable cells in the control group than the GSE-treated group after 5 months of storage. According to the sensory evaluation, neither the taste, color, odor, nor texture differed statistically during storage between groups, while overall acceptability was significantly lower in the GSE-treated group than the control after 6 months of storage.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.9 no.3
• /
• pp.1-16
• /
• 2006

The purpose of this study is to develop design model of ecological park as stormwater storage facilities. The results are as follows : First, the design model of ecological park as stormwater storage facilities consider ecological and landscape characteristics such as high efficiency of land use, function as disaster prevention, ecological water purification, formation of habitat for flora and fauna. Second, this study demonstrates two types of plane structure and eight types of designed section. They can be combined and designed depending on conditions of each site. The facilities of stormwater storage conduct disaster prevention system and ecological park. Retention pond in stormwater storage facilities for ecological park also should be made for ecological restoration in the site. Third, the ecological park provide the basis for ecological network from in-site to out-site. Therefore its conservation and restoration plan consider the ecosystems of the site. Fourth, the most important factor for maintenance and management for retention pond is keeping water quality. Sustainable Structured wetland Biotop system is suggested for ecological water purification system in the retention pond which is one of the constructed wetland system using multi-celled aquatic plant and pond. This system can also provide habitat for animals and plants, water friendly park for men, and beautiful landscape.

• The Korean Journal of Food And Nutrition
• /
• v.36 no.4
• /
• pp.236-243
• /
• 2023

The purpose of this study was to investigate the effects of sterilization, storage period and washing yuzu, according to the washing method, during the storage period. The results showed that the fungus size increased as the storage period increased, and no mold occurred in the yuzu washed with ozone water until 20 days. After 30 days of storage, a mold of 124.1±13.9 mm² was observed. The no-treatment sample had a fungus of 814.5±72.8 mm² in size on day 0 and the fungus the largest fungus was 6,362±636.7 mm² on day 30. In the case of water treatment, the fungus was 286.4±31.5~4,836.4±484.6 mm² in size. The results of the study confirmed that washing yuzu with ozone water has a sterilizing effect.

• Journal of the Korean Society of Food Culture
• /
• v.17 no.1
• /
• pp.90-95
• /
• 2002

This study was conducted to determine the desirable thawing method and storage time of Nokchaborijook(gruel made of barley, rice powder and Green tea) which made of optimum conditions as the 5.8% Green tea and 15 seconds grinding time. Decision on desirable storage time(10, 20, 30, 40, 50days), thawing method(water bath, microwave oven) of frozen Nokchaborijook were determined by sensory evaluation and physicochemical attributes. As the storage time became longer, moisture and flavonoid contents were decreased. Viscosity, the ratio of water seperation, spreadability of Nokchaborijook which stored at 30 days showed great differences between the two thawing method. Among the sensory characteristics, desirability for overall, flavor, and texture were decreased as the storage time became longer. As a result of consumer test, Nokchaborijook thawed at water bath was more desirable than Nokchaborijook thawed at microwave oven. According to the results, frozen Nokchaborijook can be using as a supplement of dietary fiber and flavonoid for the health and be using convenience food.

• The Korean Journal of Community Living Science
• /
• v.15 no.2
• /
• pp.179-187
• /
• 2004

The purpose of this study is to investigate the preservation of traditional sesame dasik when stored in different packaging material by comparing its physical and sensorial characteristics. The quality and sensory characteristics of sesame dasik that were evaluated were moisture content, water activity, number of microflora, texture profile, Hunter color different value, and sensory properties (color, chewiness, overall acceptability, etc) during the storage at 35\pm1^\circ{C}$ temperature and $73\pm{2%}$ relative humidity. And the packaging materials were paper boxes (coated 0.02mm thickness polyethylene film), plastic boxes, and oriented polypropylene laminated film. Traditional sesame dasik is made from sesame powder 100g, honey 25g, rice syrup 25g, and table salt 0.5g. During the storage period, the changes in water content and water activity of sesame dasik with different packaging material showed a slight decline. On the other hand, it increased in hardness, and "a" and "b" value of Hunter color difference during the storage. Texture profile analysis data change in hardness was the greatest after the third day in a paper box, and it was affected by the moisture content of dasik and the temperature and relative humidity of the air. Therefore plastic boxes or oriented polypropylene laminated film was found to be better suited than paper boxes for storing sesame dasik.

• Earthquakes and Structures
• /
• v.16 no.6
• /
• pp.727-741
• /
• 2019

A reinforced concrete water tank is a typical functional liquid storage structure and cracks are the greatest threat to the liquid storage structure. Tanks are readily cracked due to seismic activity, thereby leading to the leakage of the stored liquid and a loss of function. In order to study the effect of cracks on liquid storage tanks, self-healing and leakage tests for bending cracks and through cracks in the walls of a reinforced concrete water tank were conducted. Material performance tests were also performed. The self-healing performance of bending cracks in a lentic environment and through cracks in a lotic environment were tested, thereby the self-healing width of bending micro-cracks in the lentic environment in the short term were determined. The through cracks had the capacity for self-healing in the lotic environment was found. The leakage characteristics of the bending cracks and through cracks were tested with the actual water head on the crack. The effects on liquid leakage of the width of bending cracks, the depth of the compression zone, and the acting head were determined. The relationships between the leakage rate and time with the height of the water head were analyzed. Based on the tests, the relationships between the crack characteristics and self-healing as well as the leakage were obtained. Thereby the references for water tank structure design and grading earthquake damage were provided.

• Journal of Biosystems Engineering
• /
• v.19 no.1
• /
• pp.62-69
• /
• 1994

This study was designed to seek information on the heat charging and discharging characteristics of a multi-capsule type LTES(Latent Heat of Fusion Thermal Energy Storage) system, and especially prediction equation of outlet water temperature from the system. During heat charging process, the water temperature in the LTES tank increased very slowly in comparison with a predicted one and was kept near the melting point of the PCM for about 25 minutes. During heat discharging process, the latent heat discharging period of the outlet water temperature became longer as the inlet water temperature became higher and/or mass flow rate became lower. The dimensionless temperature of the outlet water was predicted by linking three equations of ${\theta}=1.1Exp(-{\tau}/0.82)$, ${\theta}=-0.06{\tau}+0.3$, ${\theta}=0.8Exp(-{\tau}/1.4)$ ($r^2{\leq}0.88$) depending on discharging period regardless of mass flow rates on the case of the inlet water temperature at $21.5^{\circ}C$.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.13 no.2
• /
• pp.80-87
• /
• 2001

Microencapsulated PCM particles are mixed with distilled water and utilized to evaluate its characteristics and performance as a thermal storage medium transporting heat. For the present study, tetradecane(C$_14H_30, T_m=5.5^{\circ}C$) is capsulated in the core with the melamine of its surface. The size of particles is well-controlled under 10${\mu}{\textrm}{m}$ in the way of in-situ polymerization with melamine-formaldehyde resin. For the experiment, the concentrations of slurries are prepared for 20wt%, 30wt%, and 40wt%. The results are compared with those of water and 100% tetradecane oil. The pure water and tetradecane start solidifying within 20 minutes after introducing cooling water into the thermal storage tank whose tank whose flow rates are varied by 125cc/min, 250cc/min, and 500cc/min. However, MicroPCM slurries are required relatively longer period of time for their phase change than pure phase change materials. That is, the entrained MicroPCM particles control its heat transfer in terms of natural convection and conducting to them.