• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.8
• /
• pp.1296-1302
• /
• 2013

The quality of fresh jujube (Zizyphus jujuba) fruit rapidly declines in the postharvest stage and thus the effective storage conditions for agricultural warehouses were investigated in this study. Fresh jujubes (~10 kg) were stored using five different storage methods: plastic box without further packaging as a control (C-PL), plastic box with hanji packaging (H-PL), plastic box with functional film packaging (F-PL), cardboard box with hanji packaging (H-CB), and cardboard box with functional film packaging (F-CB). The storage boxes were stored in a refrigerator ($0^{\circ}C$ and 80~90% RH), equipped with an ethylene gas scavenging device for 9 weeks and then the quality characteristics were analyzed. The control storage conditions of jujubes showed a substantial decline in quality with decreases in moisture content, hardness, and sugar content as well as increases in decay ratio and redness. Among the tested storage conditions, F-CB was most effective in terms of maintaining the quality of jujube fruit while maintaining firmness, weightlessness, ripening degree from redness and visible appearance. In conclusion, effective storage and packaging conditions during storage enabled maintenance of fruit quality of jujubes for 9 weeks.

• Journal of Biosystems Engineering
• /
• v.5 no.1
• /
• pp.33-42
• /
• 1980

This study was carried out to investigate the actual environmental paddy storage conditions in conventional Korean farm warehouses. The paddy storage conditions by the locations and sizes of warehouses were figured out. The effectiveness of the small insulated box for storing paddy was also examined. Observations were made at sixteen different warehouses located in Moonsan-Myeon, Jinyandg-gun, Gyungnam Province from July lst to September 28 th, the period which was considered to be the worst for storing grains. The results are as follows ; 1. the average temperatures of rough rice and air inside the warehouse were 0.9 and 0.7$^\circ$ higher than the outside air temperature. 2. The average relative humidity in warehouses was 1.5percent higher than that of the atomosphere. This fact resulted in the increased moisture content of grains. Therefore, the ventilation for equalizing the relative humidity of inside and outside of warehouses was required. 3. The dry matter of stored rough rice was decreased by 1.1 percent in average druing the observation period. In order to reduce the dry matter loss, application of new grain storing method ;hermetic storage or filling inert gas storage, was highly recommended. 4. Environmental conditions for storing rough rice in a warehouse located in a sloping site are, in general , better than those of a warehouse located in a flat site. But as far as the dry matter of rough rice was concerned, above situation is not always satisfactory. Because it is fairly frequent to observe the higher rate of moisture absorption by grains stored in a warehouse located in a sloping site. 5. Environmental conditions for storing rough rice in a large-scale warehouse were better than those in a small size warehouse. Therefore, it is advisible for farmers to store their grins in the large-scale warehouses commonly used by villagers. 6. It was undesirable to store rough in a insulated box.

• Journal of Korean Society for Atmospheric Environment
• /
• v.21 no.6
• /
• pp.573-583
• /
• 2005

Fugitive dust, which is emitted in the ambient air without first passing through a stack or duct designed to control flow, is frequently generated by means of wind erosion from storage yards at Pohang Steel Wokrs. The size distribution of fugitive dust is mostly in the range of coarse particulate which is deposited as soon as emitted and less harm to human health; however $20\%$ of fugitive dust contains PM 10 known as one of most harmful airborne pollutant. Consequently, effective control and reduction of fugitive dust is strongly requested by the local society, but it is not easy so far because the generation and dispersion of fugitive dust highly depends on meteorological conditions, and it being occurred for irregularity. This research presented a fugitive dust control system for each meteorological condition by providing statistical prediction data obtained from a statistical analysis on the probability of generating the threshold velocity at which the fugitive dust begins to occur, and the frequency occurring by season and by time of the wind direction that can generate atmospheric pollution when the dispersed dust spreads to adjacent residential areas. The research also built a fugitive dust detection system which monitors the weather conditions surrounding storage yards and the changes in air quality on a real-time basis and issues a warning message by identifying a situation where the fugitive dust disperses outside the site boundary line so that appropriate measures can be taken on a timely basis. Furthermore, in respect to the spraying of water to prevent the generation of fugitive dust from the storage piles at the storage yard, an advanced statistical meteorological analysis on the weather conditions in Pohang area and a case study of fugitive dust dispersion toward outside of working field during $2002\∼2003$ were carried out in order to decide an optimal water-spraying time and the number of spraying that can prevent the origin of fugitive dust emission. The results of this research are expected to create extremely significant effects in improving surrounding environment through actual reduction of the fugitive dust produced from the storage yard of Pohang Steel Works by providing a high-tech warning system capable of constantly monitoring the leakage of fugitive dust and water-spray guidance that can maximize the water-spraying effects.

• Preventive Nutrition and Food Science
• /
• v.7 no.2
• /
• pp.188-194
• /
• 2002

This study was carried out to observe changes in several detection factors derived from thermoluminescence (TL) of minerals separated from irradiated Korean perilla and sesame seeds during storage under normal room and darkroom conditions. The TL intensities of the first glow curves increased from 0 to 5 kGy but only slightly increase from 5 to 10 kGy. Maximum TL temperatures of the first glow curves in all irradiated samples were around 20$0^{\circ}C$, ranging from 150 to 25$0^{\circ}C$. Since the control (0 day of storage) glow curve ratios of G3 and G4, calculated from re-irradiated (1 kGy) sample were over 0.5, detection of irradiation was possible. However, because Gl ratios were below 0.1, they were classified as non-irradiated. There was n unique first glow curve shape that could be clearly seen in all irradiated samples, regardless of storage conditions, that was never seen in non-irradiated samples. In all samples, the maximum TL temperatures and shape of the second glow curve was in a lower temperature range than that of the first glow curve. Therefore, detection of irradiated Korean perilla and sesame seeds was possible fur up to 3 months after irradiation, regardless of storage conditions, by examining several TL detection factors; including TL intensity, glow curve ratios maximum TL temperatures, and the shapes of glow curves.

• Journal of Biosystems Engineering
• /
• v.31 no.3 s.116
• /
• pp.161-167
• /
• 2006

The purpose of this study is to find the optimal conditions of PCM slurry manufacturing equipment for saving the marketing cost and keeping the original quality of products. In addition, the characteristics of the movable container for shipping or distributing products is analysed. The major results are as follows. 1. PCM thermal storage system is designed with the conditions of temperature($-5{\sim}10^{\circ}C$), cold chain time(30 minutes), and one time usage(50 liter). This system includes tank, freezer, circulating pump, cycle type heat exchanger, swelling tank, equipment of supplying PCM supplying unit includes cold tank, cycle type heat exchanger, suction unit and control equipments, etc. 2. After ability test of PCM thermal storage system, it shows that the required freezing time of PCM thermal storage system is less than one of the previous system. The reason is that churn (top and bottom) and compulsion circulation are occurred simultaneously and unit cooler type method is better than chiller type method. 3. By the experiment of transportation latent heat container, it is decided that the best container is $K_1$ with latent heat temperature($0{\sim}5^{\circ}C$) and density(0.15%). However, for $K_l\;and\;K_2$, it is necessary more studies on latent heat thermal conditions and conditions of making method.

• Fisheries and Aquatic Sciences
• /
• v.15 no.2
• /
• pp.163-168
• /
• 2012

The non-utilized biomass of the aquacultured seaweed Undaria pinnatifida, particularly the rhizoid, is an alternative source of arachidonic acid (AA). Of the five aquacultured kelps that were tested, U. pinnatifida yielded the highest amount of AA, which was isolated from the rhizoids. Its identity (C20:4 n-6) was confirmed from gas chromatography-mass spectrometry spectral data. The optimal conditions for post-harvest storage or pretreatment of the rhizoids in Provasoli's enriched seawater for AA extraction were determined to be pH 7.8, 2% $CO_2$-enriched air, 20 ${\mu}mol\;m^{-2}\;s^{-1}$ light, and $10^{\circ}C$. Under these conditions, the AA content after 1 day of storage was enhanced by up to 127%. In the absence of light under ambient aeration, the AA content after 1 day of storage diminished to 90%. Rhizoids collected late in the season (April and May) contained the highest amounts of AA (approximately 2.5 mg/g tissue).

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.15 no.2
• /
• pp.219-235
• /
• 2002

This paper deals with parametric studies of the structural response of underground LNG storage tanks according to change in design conditions. In the design of underground LNG storage tank, it is requited to determine the optimal tank shape and dimension to represent a more improved structural behavior under many loading conditions and load combinations. Consequently, main factors which affect to the structural response of LNG storage tanks from planning and design up to maintenance, are investigated, and the differences in structural behavior due to those factors are analyzed. On the basis of the obtained results item parametric studies, a guideline for a more reasonable design is introduced.

• Journal of Engineering Education Research
• /
• v.20 no.1
• /
• pp.63-68
• /
• 2017

This research is as a case study of innovative engineering education system through idea factory of korea maritime and ocean university and deals with development of temperature-humidity control device (THCD) for fiber storage on composites in viewpoint of problem solving method. Fiber reinforced plastic (FRP) includes many variables on the composite manufacturing process. Above all, the interfacial adhesion between the fiber and the matrix acts as an important thing that decided mechanical property of the FRP, and also it is profoundly linked to external temperature and relative humidity. High void fraction leads to a result in interlaminar fracture. Therefore, in this research, to establish correlation between fiber reinforcement and fiber storage conditions of temperature and relative humidity we developed a THCD for fiber reinforcement. To evaluate performance of the THCD, glass fiber reinforced plastic (GFRP) is made under the extreme conditions each temperature $34^{\circ}C$, relative humidity 98 % and it can be said that there are the change of mechanical properties according to fiber storage conditions. As a result, the THCD showed sufficient possible application for understanding and applied research of composites field in material engineering. Also, we could check that the necessity of introduction of innovative system such as idea factory existed.

• Korean journal of food and cookery science
• /
• v.26 no.6
• /
• pp.840-847
• /
• 2010

In this study, we identified the volatile compounds of Artemisia princeps Pampan. cv. ssajuari (ssajuarissuk) essential oils and analyzed changes in the contents of volatile compounds under four different storage conditions, such as exposure to air at $20^{\circ}C$ and $40^{\circ}C$. Sixty-five volatile compounds consisting of 6 monoterpene hydrocarbons, 23 oxygenated monoterpenes, 16 sesquiterpene hydrocarbons, 6 oxygenated sesquiterpenes, 1 diterpene, 6 benzene derivatives, and 7 non-isoprenoid compounds were identified on the basis of their mass spectra characteristics and retention indices from original ssajuarissuk essential oils. Identified compounds constituted 90.56% of the total peak area. Borneol (10.29%) was the most abundant compound in the original ssajuarissuk essential oils, followed by 1,8-cineole (9.06%), viridiflorol (8.99%), spathulenol (8.73%), $\alpha$-thujone (5.28%), and camphor (4.39%). After six months storage at $40^{\circ}C$ with the cap opened for 3 min everyday, the total amount of volatile compounds in essential oil as determined by the percentage peak area decreased by 84.93%. The total levels of cis-sabinene hydrate, camphor, 4-terpineol, humulene oxide, $\beta$-caryophyllene oxide, and caryophyllene alcohol increased significantly. For ssajuarissuk essential oils stored under experimental conditions, changes in the contents of volatile compounds in essential oils were accelerated by temperature and contact with the atmosphere.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.2 no.1
• /
• pp.13-22
• /
• 2004

This study presents the thermal analyses of a spent fuel dry storage cask under normal and off-normal conditions. The environmental temperature is assumed to be 15 $^{\circ}C$ under the normal condition. The off-normal condition has an environmental temperature of 38 $^{\circ}C$. An additional off-normal condition is considered as a partial blockage of the air inlet ducts. Two of the four air inlet ducts are assumed to be completely blocked. The significant thermal design feature of the storage cask is the air flow path used to remove the decay heat from the spent fuel. Natural circulation of the air inside the cask allows the concrete and fuel cladding temperatures to be maintained below the allowable values. The finite volume computational fluid dynamics code FLUENT was used for the thermal analysis. The maximum temperatures of the fuel rod and concrete overpack were lower than the allowable values under the normal and off-normal conditions.