• Journal of Biosystems Engineering
• /
• v.40 no.3
• /
• pp.271-276
• /
• 2015

Purpose: Quick freezing is widely used in commercial food storage. Well-known freezing techniques such as individual quick freezing require a low-temperature coolant and small cuts for the heat-transfer efficiency. However, the freezing method for bulk food resembles techniques used in the 1970s. In this study, electromagnetic (EM) heating was applied to improve the quick freezing of bulk food. Methods: During freezing, the surface of food can be rapidly cooled by an outside coolant, but the inner parts of the food cool slowly owing to the latent heat from the phase change. EM waves can directly heat the inner parts of food to prevent it from freezing until the outer parts finish their phase change and are cooled rapidly. The center temperature of garlic cloves was probed with optical thermo sensors while liquid nitrogen (LN) was sprayed. Results: When EM heating was applied, the center cooling time of the garlic cloves from freezing until $-10^{\circ}C$ was 48 s, which was approximately half the value of 85 s obtained without EM heating. For the white radish cubes, the center cooling time was also improved, from 288 to 132 s. The samples frozen by LN spray with EM heating had a closer hardness to the unfrozen samples than the samples frozen by LN only. Conclusions: The EM heating during quick freezing functions to maintain the hardness of fresh food by reducing the freezing time from 0 to $-10^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.8
• /
• pp.1094-1097
• /
• 2007

Vibration at frequency of 20 Hz and 0.18 g of acceleration was applied to 600 g watery kimchi contained in a glass jar of 1 L at subfreezing temperature (-3 and $-6^{\circ}C$) and $10^{\circ}C$ in order to see its effect on freezing and fermentation behaviors, respectively. The vibration at the subfreezing temperature delayed the freezing process and contributed to maintaining small ice crystal slurry in subsequent frozen storage. The vibration at $10^{\circ}C$ accelerated the acid and carbon dioxide production from the watery kimchi, which may be beneficial in shortening ripening time and attaining fresh cool taste.

• Nuclear Engineering and Technology
• /
• v.56 no.3
• /
• pp.1066-1080
• /
• 2024

SMART100 has a containment pressure and radioactivity suppression system (CPRSS) for passive containment cooling system (PCCS). This prevents overheating and over-pressurization of a containment through direct contact condensation in an in-containment refueling water storage tank (IRWST) and wall condensation in a CPRSS heat exchanger (CHX) in an emergency cool-down tank (ECT). The Korea Atomic Energy Research Institute (KAERI) constructed scaled-down test facilities, SISTA1 and SISTA2, for the thermal-hydraulic validation of the SMART100 CPRSS. Three separate effect tests were performed using SISTA1 to confirm the heat removal characteristics of SMART100 CPRSS. When the low mass flux steam with or without non-condensable gas is released into an IRWST, the conditions for mitigation of the chugging phenomenon were identified, and the physical variables were quantified by the 3D reconstruction method. The local behavior of the non-condensable gas was measured after condensation inside heat exchanger using a traverse system. Stratification of non-condensable gas occurred in large tank of the natural circulation loop. SISTA2 was used to simulate a small break loss-of-coolant accident (SBLCOA) transient. Since the test apparatus was a metal tank, compensations of initial heat transfer to the material and effect of heat loss during long-term operation were important for simulating cooling performance of SMART100 CPRSS. The pressure of SMART100 CPRSS was maintained below the design limit for 3 days even under sufficiently conservative conditions of an SBLOCA transient.

• The Korean Journal of Food And Nutrition
• /
• v.14 no.5
• /
• pp.457-466
• /
• 2001

In this study. HACCP system was applied to improve the quality of instant ablactation baby food with rising sanitary problem among SunSig(powder of roasted grains and vegetables) . It took about 9min 30 second to produce and the temperature status of raw materials were 30.9∼31.8$\^{C}$. Raw material and production phase goods had average 6.2 in pH and 0.23∼0.63 in water activity. The average number of total aerobic bacteria(TAB) and coliform were 1.4$\times$10$^4$ CFU/g, 5.5$\times$10 CFU/g in raw materials. And the number became 8.7$\times$10$^2$ CFU/g, 6.9$\times$10 CFU/g after 1st grinding step. The distributions of TAB and coliform in equipments were 3.8$\times$10$^4$ CFU/㎠, 8.0$\times$10 CFU/㎠ on the average. According to storage temperature, variations of number of TAB coliform were slight at 4$\^{C}$ but increased at 20$\^{C}$ and 30$\^{C}$ . Therefore following subjects can be issued on the basis of results. Minimize the storage time and keep at cool temperature. 1st and 2nd grinders should be managed hygienically. Establish the heating step during the production of instant action baby food. Instant ablactation baby food produced should be stored at cool and freeze condition.

• Korean Journal of Weed Science
• /
• v.8 no.3
• /
• pp.265-272
• /
• 1988

This experiment was carried to investigate the germination pattern in relation to temperatures and lights, and the emergence pattern in relation to seeding depths, lights and the alpha amylase activity of Youngia sonchifolia, Lactuca indica var. laciniata, Ixeris dentata var. albiflora and Ixeris polycephala. In Y. sonchifolia, the optimum germination temperature was $25^{\circ}C$, the optimum seeding depth to emerge was 0 mm and it could emerge in 0-5mm. In L. indica var. laciniata under cool storage, the optimum germination temperatures were $19^{\circ}C-28^{\circ}C$, the optimum seeding depth was 5mm and it could emerge in 0-20mm. In L. indica var. laciniata under room storage, the optimum germination temperature was $25^{\circ}C$ the optimum seeding depth was 5mm and it could emerge in 0-10mm. In I. dentata emerge was and 0mm and it could emerge in 0-5mm. In I. polycephla, the optimum temperatures were $16^{\circ}C-19^{\circ}C$, the optimum seeding depth to emerge was 0mm and it could emerge in 0-5mm. The alpha amylase activity was lower Y. sonchifolia, L. indica var. laciniata and I. dentata var. abiflora than barley cultivar Dongbor#1. And the increased pattern of alpha amylase activity was likely to it of germination rate.

• Applied Microscopy
• /
• v.42 no.1
• /
• pp.43-48
• /
• 2012

This study shows that ceresin wax, candellila wax and microcrystalline wax mixed together with liquid paraffin oil to produce lipsticks (LS-1, LS-2) and capric/caprylic triglyceride oil added to produce lipsticks (LS-3, LS-4). After each type of lipsticks were molded, LS-1 and LS-3 was put into a cooling chamber ($5^{\circ}C$). LS-2 and LS-4 was put into a cooling chamber ($5^{\circ}C$) for 18 hours and kept in an incubator ($45^{\circ}C$) for 5 hours and put again into a cool chamber ($5^{\circ}C$). After that, the wax's three dimensional network structure was observed under scanning electron microscopy. Regardless of the kind of oil, the LS-1 and LS-3 wax structure had more distinct shape than the lipstick wax structure of LS-2 and LS-4. Also, regardless of the kind of wax, the three dimensional network structure was modified as the storage temperature increased. As a result, the lipstick's molding temperature increased, the wax's structure size also increased and the shape irregularly modified. This modification causes sweating phenomenon which affected lipstick's surface rheological property.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.05a
• /
• pp.496-499
• /
• 2014

Xe Gas is moved to Target from GPM. It is Used to feasible nuclear reaction from proton of 30MeV Cyclotron being investigated by the Xe-124 Gas target System. This system is divided into four parts. Hardware was constructed by solidworks and Helium Supply is to cool the Havor Foil. Water has the job of cooling down the temperature when Xe Gas is being investigated in the target. Temperature and pressure gauges are attached to be checked easily. GPM(Gas Process Manifold) has the part that prepares to transport Xe Gas. There are Storage Vessel that stores Xe Gas, the cold trap that filters humidity and impurity and lastly storage vessel that temporarily stores Xe Gas. HCS(Helium Circulation System) using the Helium to cleaning and cooling. these parts are used to SIEMENS PLC and Pcvue Program. Because It is more comfortable and easy maintenance.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.40 no.1
• /
• pp.44-51
• /
• 1995

This investigation was conducted to determine the effect of the optimum planting date and place for good seed production on growth variation, grain yields, different of variety, infection of seed by fungi, and seed germination and vigor after room storage. Early maturity Korean soybean variety, Keunolkong, and introduced vegetable soybean variety, Fukura-edamame, were planted at field of YAES. and high cool land of Sajapyong in Milyang（altitude, 850m） on May 15 （early）, June 15 （mid.）, and July 15 （late） in 1991. The emergence and vegetative period gradually increased in the early planting date. The grain yield, seed weight, pod number, healthy grain yield also increased when Keunolkong was planted on early date. The healthy seed rate, Keunolkong increased in the early planting date, whereas that of Fukura also increased in the late planting date. Infection ratio of grain to phomopsis seed decay （Phomopsis spp. ' Diaporthe phaseolorum） in Fukura steadily increased in the early planting date. Infection ratio of grain to purple seed stain （Cercospora kikuchii） generally increased in the mid and late planting date. The seed germination and seedling vigor after room storage from five to six months gradually increased in the late planting date. And seed germination of Fukura rapidly decreased in the early planting date. Therefore, the optimum planting date for good seed production in early maturity vegetable soybean was June 15 in terms of harvesting time avoid a high temprature and humidity.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.55 no.3
• /
• pp.220-225
• /
• 2010

Soybean sprouts produced at optimal temperature are placed or displayed for several days in market shelf of relatively cool temperature (ca. $13^{\circ}C$). During this period a number of changes occur including changes in color, smell, taste, nutritional quality, etc. In order to investigate the changes of these factors, soybean sprouts packed in plastic film bag (OPP+PE) were stored at the two different temperature ($3^{\circ}C$ and $13^{\circ}C$). Morphological characters, physicochemical changes and enzymes activity related to visible quality (color) of soybean sprouts were examined. The numbers of fine roots were greater and hypocotyls were longer in soybean sprouts stored at $13^{\circ}C$, although there was no significant difference in diameter, fresh weight and dry weight of hypocotyls between the two storage temperatures. Browning of hypocotyl, as an indicator of a typical deterioration in sprout quality, was highly dependent on the activity of polyphenol oxidase (PPO). Considering the low level of soluble protein in hypocotyls, the relatively higher activity of PPO suggested a critical role of PPO in stored soybean sprouts. PPO activity of sprouts stored at $13^{\circ}C$ was 2-fold higher than that of sprouts stored at $3^{\circ}C$ after 4 days. In sprouts stored at $13^{\circ}C$, the PPO activity was increased from day 0 until 6 days and since then, it was not detected. Crude protein content was increased to 30.9~35.4% based on dry weight with extended storage period. The change in crude protein was greater in sprouts stored at high temperature ($13^{\circ}C$). Total free amino acid content was increased in both temperatures. However, the changing rate of free amino acid was greater in sprouts stored at $13^{\circ}C$.

• Solar Energy
• /
• v.2 no.2
• /
• pp.29-36
• /
• 1982

The Solar Energy R&D Department of KIER under the auspice of the Korean government is pushing hard on the development of the passive solar technology with high priority for the expeditious widespread use of solar energy in Korea, since the past few years of experiences told us that the active solar technology is not yet ready for massive commercialization in Korea. KIER has completed the construction of the Solar Energy Research & Test Center in Seoul, which houses the major facilities for its all solar test programs. The Center was designed as a passive solar building with great emphasis on the energy conserving ideas. The Center is not only the largest passive building in Korea, but also the exhibit center for the effective demonstration of the passive heating and cooling technology to the Korean public. The Center was designed to satisfy the requirements based on the technical and economical criteria set by the KIER. Careful considerations, therefore, were given in depth in the following areas to meet the requirements. 1) Passive Heating Concepts The Center employed the combination of direct and indirect gain system. The shape of the Center is Balcomb House style, and it included a large built-in sunspace in front. A partition, consists of transparent and translucent glazings, separates the sunspace and the living space. Since most activities in the Center occur during the day time, direct utilization of the solar energy by the living spaces was emphasized with the limited energy storage capacity. 2) Passive Cooling Concepts(for Summer) Natural ventilation concept was utilized throughout the building. In the direct gain portion of the system, the front glazing can be openable during the cooling season. Natural convection scheme was also applied to the front sunspace for the Summer cooling. Reflective surfaces and curtains were utilized wherever needed. 3) Auxiliary Heat ing and Cooling System As an auxiliary cooling system, mechanical means(forced convection system) were adopted. Therefore forced air heating system was also used to match the duct work requirements of the auxiliary cool ing system. 4) Effect ive Insulation & Others These included the double glazed windows, the double entry doors, the night glazing insulation, the front glazing-frame insulation as well as the building skin insulation. All locally available construction materials were used, and natural lightings were provided as much as possible. The expected annual energy savings (compared to the non-insulated conventional building)of the Center was estimated to be about 80%, which accounts for both the energy conservation and the solar energy source. The Center is being instumented for the actual performance tests. The experimental results of the simplified tests are discussed in this paper.