• Solar Energy
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• v.9 no.1
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• pp.70-77
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• 1989

Sodium pyrophosphate that melting point is $79-80^{\circ}C$ have been Studied on heat storage and heat discharge. In heat storage process, sodium pyrophosphate was kept up initial temperature $50^{\circ}C,\;60^{\circ}C,\;70^{\circ}C$ which melt by heated water at temperature $85^{\circ}C,\;90^{\circ}C,\;95^{\circ}C$. In heat discharge process, initial temperature of sodium pyrophosphate was maintained at temperature $85^{\circ}C,\;90^{\circ}C,\;95^{\circ}C$ which varied cooling temperature $50^{\circ}C,\;60^{\circ}C,\;70^{\circ}C$. The experiment has been reached conclusions as follows. 1) Heat transfer properties of phase change material is controlled by conduction during heating and cooling process. 2) The temperature increased rapidly at initial stage and transient region increase slowly because of characteristic of latent heat. 3) The lower cooling water temperature is the less the time that get to thermal equivalent state take during discharge process. 4) The higher cooling water temperature is the less temperature difference between top and bottom in P.C.M during discharge process.

• Journal of Food Hygiene and Safety
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• v.13 no.4
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• pp.383-387
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• 1998

This study was undertaken with packed tofu products to serve as a basic source for sanitary control of tofu production by detecting spoilage bacteria in tofu from which are isolated, investigating heat-resistance and growth characteristics of spoilage bacteria. Isolated strains were confirmed as relevant strains in tofu spoilage, and Strain No. Tl, T2 show 92% probability to be Enterobacter amnigenus, and 96% to be Flavobacterium indologenes according to the result of identifYing strains by using Vitek system. Both strains had high viability at $35^{\circ}C$, pH 6.5. In the heat-resistance test of isolated strains, Enterobacter amnigenus Tl was treated for 2 mins, the number remained 56.3% of the initial number at $60^{\circ}C$, 37.8% at $70^{\circ}C$, 34.0% at $80^{\circ}C$ and 22.2% at $90^{\circ}C$, and Flavobacterium indologenes T2 was treated for 2 mins, the number remained 74.8% of the initial number at $60^{\circ}C$, 65.7% at $70^{\circ}C$, 37.8% at $80^{\circ}C$ and 9.3% at 90^{\circ}C$.

• Journal of Life Science
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• v.8 no.1
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• pp.32-39
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• 1998

The length and G/C concent of regions of an aphid rDNA unit that spans 13,061bo with 59% G/C content. flolowing belowing below are the those results, 5’ETS is 843bp in length with 69% G/C content, 18S is 2,469bp in length with 59% G/C content, ITS I is 229bp in length with 70% G/C content, 5.8S is 160bp in length with 63% G/C content, ITS II is 325bp in length with 70% G/C content, 28S is 4, 147bp in length with 60% G/C content, IGS is 4,888bp in length with 55% G/C content.

• The Korean Journal of Food And Nutrition
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• v.28 no.5
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• pp.766-773
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• 2015

This study analyzes the chemical composition of green tea, white tea, yellow tea, oolong tea and black tea with respect to extraction temperature and time. The optimum extraction conditions for these teas were determined by assessing the chemical composition of tea brewed at different temperature (50, 60, 70, $80^{\circ}C$) and extraction times (1, 3, 5, 10 minute). Catechins contents were the largest at 5 minutes and generally declined by 10 minutes. Green tea catechins contents were highest when brewed at $70^{\circ}C$ and besides other teas a change of the trend variation at 70 and $80^{\circ}C$. These temperatures did not extract theaflavins in green tea. Extract temperature and time did not significantly affect theaflavins content of white tea, yellow tea, and oolong tea. Black tea, however, was noticeably dependent on extract conditions, which were most effective at $70^{\circ}C$, brewed for 5 minutes. Caffeine content of green tea, yellow tea, and oolong tea was highest at 5 minutes, but temperature did not appear to affect the content. White tea and black tea caffeine content was highest when brewed at $70^{\circ}C$ for 5 minutes. Theobromine content of green tea, yellow tea, oolong tea, and black tea did not show major differences between the study times or temperature, though the content in white tea increased with higher temperatures when brewed for 5 minutes. The extraction of phenolic compounds increased until 5 minutes, and showed not further increase at 10 minutes. Antioxidant capacity of green tea, white tea, and yellow tea were maximized at $70^{\circ}C$ for 5 minutes or $80^{\circ}C$ for 3 minutes, while oolong and black tea were reached maximum antioxidants at $70^{\circ}C$ for 5 minutes. In general, to optimize the beneficial chemical content of brewed tea, a water temperature of $70^{\circ}C$ for 5 minutes is recommended.

• The Korean Journal of Food And Nutrition
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• v.28 no.5
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• pp.745-751
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• 2015

This study was performed to investigate the quality characteristics such as pH, total acidity, browning index, 5-hydroxymethylfurfural (5-HMF), fructose, S-allyl-L-cysteine (SAC), total polyphenol, and DPPH radical scavenging activity of aged garlic at different aging temperatures and periods. Aging temperature and period had a significant (p<0.05) effect on the quality characteristics of garlic. The pH in aged garlic significantly (p<0.05) decreased with increasing aging temperatures and periods, while the total acidity, browning index, and 5-HMF levels increased. The 5-HMF levels in garlic aged at 60 and $70^{\circ}C$ increased from 0.08~3.30 and from 0.05~106.07 mg/100 g, respectively. The fructose content in garlic aged at $60^{\circ}C$ gradually increased from 0.77 to 14.57%, while that of garlic aged at $70^{\circ}C$ increased from 1.07 to 19.75% until day 30, after which it decreased. The SAC level in raw garlic was 47.09 mg/100 g. The SAC contents of aged garlic differed significantly according to aging temperature and period. The SAC levels in garlic aged at $60^{\circ}C$ and $70^{\circ}C$ were in the range of 15.28~100.5 and 12.41~85.55 mg/100 g, respectively. The total polyphenol contents of garlic aged at $60^{\circ}C$ and $70^{\circ}C$ were 6.01 and 6.67 fold higher, respectively, than those in raw garlic. The DPPH radical scavenging activity of aged garlic also showed a tendency to increase during aging.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.70.1-70
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• 2003

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.70.2-70
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• 2003

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.11a
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• pp.70-70
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• 1996

• The Journal of Advanced Prosthodontics
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• v.9 no.6
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• pp.453-462
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• 2017

PURPOSE. The purpose of this study was to investigate the in vitro cytotoxicity of thermoplastic denture base resins and to identify the possible adverse effects of these resins on oral keratinocytes in response to hot water/ food intake. MATERIALS AND METHODS. Six dental thermoplastic resin materials were evaluated: three polyamide materials (Smile tone, ST; Valplast, VP; and Luciton FRS, LF), two acrylic materials (Acrytone, AT; and Acryshot, AS), and one polypropylene resin material (Unigum, UG). One heat-polymerized acrylic resin (Vertex RS, RS) was chosen for comparison. After obtaining extracts from specimens of the denture resin materials (${\phi}=10$ mm and d=2 mm) under different extraction conditions ($37^{\circ}C$ for 24 hours, $70^{\circ}C$ for 24 hours, and $121^{\circ}C$ for 1 hour), the extracts (50%) or serial dilutions (25%, 12.5%, and 6.25%) in distilled water were co-cultured for 24 hours with immortalized human oral keratinocytes (IHOKs) or mouse fibroblasts (L929s) for the cytotoxicity assay described in ISO 10993. RESULTS. Greater than 70% viability was detected under all test conditions. Significantly lower IHOK and L929 viability was detected in the 50% extract from the VP ($70^{\circ}C$) and AT ($121^{\circ}C$) samples (P<.05), but only L929 showed reduced viability in the 50% and 25% extract from LF ($37^{\circ}C$) (P<.05). CONCLUSION. Extracts obtained from six materials under different extraction conditions ($37^{\circ}C$, $70^{\circ}C$, and $121^{\circ}C$) did not exhibit severe cytotoxicity (less than 70% viability), although their potential risk to oral mucosa at high temperatures should not be ignored.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.730-736
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• 1997

Pasteurization of low salt dongchimi juice was studied for the effect of heating temperature and time on total viable counts and some physicochemical and sensory properties. The juice was prepared by fermentation of the radish at $20^{\circ}C$ in 0.5% NaCl solution. Heating the juice (pH 3.8) at $60{\sim}100^{\circ}C\;for\;5{\sim}30$ min caused little changes in pH and total acidity while the lightness (L value) was decreased and the turbidity, a and b values of color were increased as the heating temperature and time increased. The total viable counts of microorganisms was significantly decreased to 18 at $60^{\circ}C$ and 6 at $70^{\circ}C$ after 30 min heating and was not detected after heating at 90 and $100^{\circ}C$ for 10 min. The sensory test showed that heating up to $70^{\circ}C$ for 20 min caused a little cooked off-flavor. After storage of the pasteurized juices at $30^{\circ}C$ for 10 days, the pH, total acidity and color were changed little while the unheated juice changed significantly. The total viable counts of microorganisms was also remained initial level after pasteurization. Therefore pasteurization at $60^{\circ}C$ for 30 min or $70^{\circ}C$ for 20 min was recommendable in the aspects of storage stability and quality characteristics.