• Nuclear Engineering and Technology
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• v.52 no.5
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• pp.964-974
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• 2020

The small modular reactors (SMRs) of the integrated pressurized water reactor (IPWR) type have been widely developed owing to their enhanced safety features. The SMR-IPWR adopts passive residual heat removal system (PRHRS) to extract residual heat from the core. Because the PRHRS removes the residual heat using the latent heat of the water stored in the emergency cooldown tank, the PRHRS gradually loses its cooling capacity after the stored water is depleted. A quick restoration of the power supply is expected infeasible under station blackout accident condition, so an advanced PRHRS is needed to ensure an extended grace period. In this study, an advanced design is proposed to indirectly incorporate a dry air cooling tower to the PRHRS through an intermediate loop called indefinite PRHRS. The feasibility of the indefinite PRHRS was assessed through a long-term transient simulation using the MARS-KS code. The indefinite PRHRS is expected to remove the residual heat without depleting the stored water. The effect of the environmental temperature on the indefinite PRHRS was confirmed by parametric analysis using comparative simulations with different environmental temperatures.

• Journal of Magnetics
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• v.17 no.4
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• pp.233-241
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• 2012

In this work, Monte Carlo simulation was used to investigate the magnetization properties of thin ferromagnetic films under a perturbation from a supplied heat pulse on one surface of the films. The finite difference method was used to extract the local temperature of each layer of the films as a function of time for various heat source power and heating period. Then, with the variation of the films temperature, Metropolis method was used to update the magnetic moment in magnetic grain, under the Ising framework and using the FePt parameters. With the extracted magnetization profiles, the relationship between magnetization relaxation in accordance with relevant heat parameters and films thickness was reported and discussed, with a purpose to form a database for future use.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1025-1030
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• 2008

We develop heat exchanger modules for a multi-burner boiler. The heat exchanger module is kind of a heat recovery steam generator (HRSG). This heat recovery system has 4 heat exchanger modules. The 1st module consists of 27 bare tubes due to high temperature exhaust gas and the others consist of 27 finned tubes. The maximum steam pressure of each module is 10 bar and tested steam pressure is 4 bar. In order to test these heat exchanger modules, we make a 0.5t/h flue tube boiler (LNG, $40\;Nm^3/h$). The test results of 100% boiler load show that heat transfer rate of 1st module is 49.7 Mcal/h which is 34% of total heat transfer rate and that of 2nd module is 82.6 Mcal/h which is 57% of total heat transfer rate. The reason of higher the heat transfer rate of 2nd module than that of 1st module is that the 2nd heat exchanger module has finned tubes instead of bare tube. The boiler load 50% results show that only 2 heat exchanger modules are needed to extract the heat from the flue gas to water. From this result, it is very important of optimum design of the first finned tube among all water tubes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.969-974
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• 2011

This study was performed to investigate the inhibitory activity of Ecklonia cava (EC) against lipase and the stability of this activity under various heat and pH conditions. As a result, EC ethanol extract showed lipase inhibitory activity of 59, 34 and 19% at concentrations of 5, 2.5 and 1 mg/mL, whereas the water extract showed low inhibitory activity at all concentrations compared to that of the ethanol extracts. In a heat and pH stability test, the inhibitory activity of the EC ethanol extract increased with heat treatment at $121^{\circ}C$ for 15 min compared with the control and was stable in the pH range of 2~10. Therefore, the EC ethanol extract could be useful as a natural anti-obesity agent.

• Korean journal of food and cookery science
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• v.8 no.2
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• pp.95-105
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• 1992

This study was carried on the Seasoning Oil production by Autoclaving Method in order to research a developed method. The Raw, Extract states of seasoning vegetables-Garlic, Onion and Ginger were added 40, 60% (w/w) of total amounts to corn salad oil. All samples treated with various conditions were determined physicochemical characteristics by Acid value, Peroxide value, Iodine value, Refractive Index, and Volatile Carbonyl Compound Content during incubating $(40{\pm}2^{\circ}C)$ and heating $(185{\pm}2^{\circ}C)$. The results were obtained as follws; 1. During incubation at $40{\pm}2^{\circ}C$, the order of antioxidative effects among seasoning vegetables was Ginger>Garlic>BHA>Onion and Extract state were more effective man Raw state. also the antioxidative effects of the seasoning vegetables were increased proportionally with the concentration in the Seasoning Oils. 2. In the case of heat treatment $(185{\pm}2^{\circ}C)$, AV, POV, IV and RI of each Seasoning Oil were changed very sharply. The antioxidative effect and Carbonyl Compound Content according to heat treatment differed from the type and concentration of seasoning vegetables in oil. Ginger had the most excellent antioxidative effect among seasoning vegetables, and m any case, the adding states of seasoning vegetables into oils were more effective in Extract man Raw states. 3. According to those results, each Seasoning Oil made from Garlic, Onion, Ginger was shown to have antioxidative properties specially in Ginger-Extract-Seasoning Oil. also the Autoclaving Method was thought to be rational method in preparation of Seasoning Oil.

• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.2
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• pp.277-281
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• 2013

Silkworm powder, which contains 1-deoxynojirimycin (DNJ), is a promising complementary and alternative medicine (CAM) in Korea. Silkworm powder was produced from Yeonnokjam pupae at d 3 of the 5th instar at the National Academy of Agricultural Science. The powder was derivatized with 9-fluorenylmethyl chloroformate (FMOC-Cl), and the DNJ-FMOC content was measured by HPLC. We investigated the content of 1-DNJ in the silkworm powder and its glucose-lowering effect when it was treated at different temperatures. The content of 1-DNJ was the lowest at $150^{\circ}C$, while it was constant at other temperatures. The silkworm extract powder was orally administered to diabetic mice (20 mg/kg/d) for 4 wk. Water intake did not significantly change when compared with the control group (T0). The blood glucose levels significantly decreased when mice where administered silkworm powder treated at $60^{\circ}C$ (T60) compared to the control group, but no difference was observed between the groups T100 and T150. Moreover, the blood levels of TG significantly decreased compared with the control group. Based on these results, we surmise that the properties of the silkworm extract powder were stable upon heating at $100^{\circ}C$ but not at $150^{\circ}C$.

• Journal of Ginseng Research
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• v.43 no.2
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• pp.252-260
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• 2019

Background: Increases in the average global temperature cause heat stress-induced disorders by disrupting homeostasis. Excessive heat stress triggers an imbalance in the immune system; thus protection against heat stress is important to maintain immune homeostasis. Korean ginseng (Panax ginseng Meyer) has been used as a herbal medicine and displays beneficial biological properties. Methods: We investigated the protective effects of Korean ginseng extracts (KGEs) against heat stress in a rat model. Following acclimatization for 1 week, rats were housed at room temperature for 2 weeks and then exposed to heat stress ($40^{\circ}C$/2 h/day) for 4 weeks. Rats were treated with three KGEs from the beginning of the second week to the end of the experiment. Results: Heat stress dramatically increased secretion of inflammatory factors, and this was significantly reduced in the KGE-treated groups. Levels of inflammatory factors such as heat shock protein 70, interleukin 6, inducible nitric oxide synthase, and tumor necrosis factor-alpha were increased in the spleen and muscle upon heat stress. KGEs inhibited these increases by down-regulating heat shock protein 70 and the associated nuclear $factor-{\kappa}B$ and mitogen-activated protein kinase signaling pathways. Consequently, KGEs suppressed activation of T-cells and B-cells. Conclusion: KGEs suppress the immune response upon heat stress and decrease the production of inflammatory cytokines in muscle and spleen. We suggest that KGEs protect against heat stress by inhibiting inflammation and maintaining immune homeostasis.

• The Korea Journal of Herbology
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• v.30 no.4
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• pp.29-35
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• 2015

Objectives : The objective of this research was to investigate the antibacterial and antioxidant activities of bio-fermented Sanguisorbae Radix extract.Methods : The Sanguisorbae Radix extract was fermented byStreptococcus thermophilus,and their products was tested for antibacterial activity against pathogenic microorganisms namely,Bacillus cereus,Bacillus subtilis,Staphylococcus aureus,Escherichia coli,Vibrio parahaemolyticusandSalmonella typhimuriumby paper disc diffusion method and the antioxidant activities of extract was evaluated by five different assays as electron donating ability(EDA), superoxide dismutase(SOD)-like activity, polyphenol, flavonoid contents and nitrite scavenging ability.Results : The bio-fermented Sanguisorbae Radix extract was safe from heat. Antibacterial activity of fermented Sanguisorbae Radix extract appeared relatively highly againstBacillus cereusandStaphylococcus aureusand didn't show any difference. EDA in comparison to Vitamin C showed over 90% activity at about the same time of Sanguisorbae Radix extract expressed highly. SOD activity showed 15% in fermentation before and after. The nitrite scavenging ability of Sanguisorbae Radix extract before and after fermentation showed higher numerical value over 70% in pH 2.5 than that of butylated hydroxytoluene(BHT). But SOD activity, EDA and nitrite scavenging ability were not different between the Sanguisorbae Radix extract before and after fermentation. Total polyphenol content expressed over about 20 mg/g, and that of the Sanguisorbae Radix extracts was increased than that of the fermented Sanguisorbae Radix extracts.Conclusions : The results suggest the usefulness of developing functional materials using antioxidant active Sanguisorbae Radix extract was fermented bySalmonella typhimuriumwith high polyphenol contents and nitrite scavenging ability.

• The Korean Journal of Community Living Science
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• v.21 no.4
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• pp.641-649
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• 2010

To make sure of the usefulness of extract of Rubus coreanus Miquel for producing functional feeding honey, we compared some antioxidative indicators of feeding honey using extract of Rubus coreanus Miquel with acacia honey, SueBee Clover honey(USA), feeding honey on the market. The water content of four honeys were 16.6~26.5%, pH were 3.18~3.70, and titratable acidity ranged 0.018~0.022%. The phenolic compound contents of SueBee Clover honey and feeding honey using extract of Rubus coreanus Miquel were 8.3 mg/100 g and 7.3 mg/100 g, respectively, and were significaltly higher thgheacacia honey and feeding honey on the market. The flavonoid contents per 100 g of honey ranged from 2.3 mg(acacia honey) to 15.0 mg(SueBee Clover honey). DPPH anion scavenging activity of four honeys were not high. 0.5~2.0 g/ml of feeding honey using extract of Rubus coreanus Miquel was 16~36% and showed a concentration-reliant figure. At the concentration of 0.25~0.75 mg/ml, the reducing power of four honeys increased concentration-dependently, and the power of 0.25 mg/ml of feeding honey using extract of Rubus coreanus Miquel was corresponding to thgt of $150{\mu}g$/ml of a vitamin C solution. ABTS radical scavenging activity of feeding honey using extract of Rubus coreanus Miquel was 43.3~68.4%; the highest activity amongst all samples. When plotting the dose-response curve, ABTS radical scavenging activity also increased as their concentration increased from 62.5 mg/ml to 500 mg/ml. The heat treatment reduced the phenolic compound contents of acacia honey and feeding honey using extract of Rubus coreanus DPPH anion scavenging activity of feeding honey on the market and feeding honey using extract of Rubus coreanus Miquel did not changed significaltly after heating for 20 min, and the three honey except SueBee Clover honey maintained the reducing power with the same treatment.

• The Korea Journal of Herbology
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• v.31 no.6
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• pp.63-71
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• 2016

Objective : To suggest a scientific evidence of Aconitum carmichaeli Debx. (Aconiti Lateralis Radix Preparata: ALRP) as one of cooling and heating medicines on the regulation of body temperature, we investigated the effects of ALRP water extract on hypothyroidism. Methods : Hypothyroidism was induced by intradermal injection with PTU for 4 weeks in SD rats. ALRP extract or L-thyroxine as a control drug was orally administrated for 2 weeks with PTU injection in rats. The physiological and serological parameters were measured in rats. The histological change of thyroid tissues was observed by H&E staining, and also the expression of thermo-regulating proteins was determined by Western blot in dorsal root ganglia and brain tissues of rats. Results : The administration of ALRP extract in PTU-induced hypothyroidism rats was significantly increased body temperature, but did not changes on body weight, food and water intake. ALRP extract did not effect on the levels of TSH and T4 in the hypothyroidism rats. ALRP extract significantly decreased the levels of GPT, glucose, HDL-cholesterol, LDL-cholesterol, and total cholesterol in the hypothyroidism rats. In histological observation, the enlarged epithelium and atrophic follicles with higher concentration of follicular cells on hypothyroidism were improved by ALRP extract. In addition, ALRP extract increased the expression of TRPV1 and TRPM8 ion channel proteins in hypothyroidism rats. Conclusion : These results indicate that ALRP extract can improve PTU-induced hypothyroidism through regulation of body temperature and lipid accumulation. The action mechanism of ALRP extract is related with body temperature control by thermoregulation with TRP ion channels.