• Applied Biological Chemistry
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• v.27 no.2
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• pp.55-63
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• 1984

Lethal effect on Chinese radish Kimchi was investigated by using a pilot scale Kimchi pasteurizer. A simulation model was presented so as to predict the change in viable cell concentration of the Kimchi during pasteurization. D values of microorganisms in the Kimchi were found to be 2.21, 1.62, 0.73, 0.39 and 0.21min at 60, 64, 70, 75 and $80^{\circ}C$, correspondingly, and thereby z value was $19^{\circ}C$. One cycle time required was 0.99min at flow rate of 4 l/min. The ratio of lethality in preheating section to total lethality was 0.3 and the ratio of lethality in holding, precooling and cooling sections to total lethality was 0.7. The experimental data were in good agreement with the values simulated by two model equations to which linear and exponential temperature profiles were applied at $65^{\circ}C\;and\;70^{\circ}C$ in holding section.

• Fire Science and Engineering
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• v.21 no.3
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• pp.78-83
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• 2007

Diesel, a kind of petroleum, which is used in vehicles, vessels, boilers etc causes great damage when a fire happens, because it has higher caloric value than gasoline or kerosene has at burning. Therefore, pool fire experiment was carried using diesel which is sold on the gas station and radiation heat flux that occurs from flame and inner temperature of flame at burning was estimated. The maximum instantaneous flame temperature of diesel was more than $900^{\circ}C$, and the average of maximum flame temperature was $800^{\circ}C$ which occurred at 0.5 H/D distance from the surface of inflammable liquid, the distance has more long that has the lower the temperature of flame. In case of radiation heat flux, it grew to vary according to the size and amount of sample. When the size of a container for experiment was 0.5 m and sample layer was 13 mm and 20 mm, the radiant heat was 92.29 kW and 117.43 kW each. When the container was 1.0 m, it was 364.35 kW and 405.88 kW each.

• Fire Science and Engineering
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• v.13 no.3
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• pp.19-26
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• 1999

$CO_2$ extinguishing system is the most $\phi$pular among the gas extinguishing system. $CO_2$ is usually stored with liquified state. But, it gasifies at the tip of nozzle when $CO_2$ was released through the pipe and head. A ro$\alpha$n temperature is very low when $CO_2$ was released. So electrical instrument, magnetic storage equipment and memory semiconductor are electrically or physically injured by cooling effect in a few minutes. So, we intend to find out temperature profile and electrical damage in compartment area, and supply basic d data for research and making standards and code through the full scale experiment. As result of experiment on the damage due to cooling effect from $CO_2$ extinguishing system, i instantaneous discharging temperature. was $-82.5^{\circ}C$ in average. An average temp. in the compartment after discharging $CO_2$ was $-40^{\circ}C$.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.25 no.3
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• pp.117-123
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• 2019

The general Impulse Sealer has a problem of sealing quality because continuously sealing process results in an undesirable temperature rise, which may accumulate the heat during the operation. In order to address such a drawback, the controlled sealing temperature method can be effectively utilized compared with the general controlled time method. As such, a temperature sensor with capability of detecting the sealing temperature was installed, and a separate PCB was manufactured to control the sealing temperature by measuring and calculating the detected temperature. The temperature changes during the temperature rise and maximum temperature after continuously operation were investigated using an Impulse Sealer system. Next, the results obtained from experiment were compared with each other. As such, the maximum temperature was 70.3℃, whereas 8.9℃ was recorded as control temperature. It implies that this controlled temperature system prevented the undesirable temperature rise, thereby causing a consistent sealing quality.

• Journal of Oral Medicine and Pain
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• v.30 no.4
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• pp.457-464
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• 2005

The purpose of our study was to investigate whether the intrapulpal temperature during cavity preparation of enamel or dentin with Er:YAG laser still remained in range of safety for dental pulp protection when combined with appropriate water flow rate. The effect of different pulse repetition rates at the same pulse energy during ablation was evaluated as well. Caries-free, restoration-free extracted human molar teeth were prepared for the specimen and divided two experimental groups of enamel and dentin. Each group comprised 5 specimens and each of tooth specimens were embedded into a resin block each and measuring probe was placed on the irradiated pulpal walls. For experiments of dentin ablation, enamel layers were prepared to produce dentin specimen with a same dentin thickness of 2 mm. A pulse energy of Er:YAG laser was set to 300 mJ and three different pulse repetition rates of 20 Hz, 15 Hz and 10 Hz were employed. Laser beam was delivered with 3 seconds and less per application over enamel and dentin surfaces constant sized by $3\;mm{\times}2\;mm$ and water spray added during irradiation was a rate of 1.6 ml/min. Temperature change induced by Er:YAG laser irradiation was monitored and recorded While enamel was ablated, there was no significant difference of temperature related to pulse repetition rates(p=0.358) and temperature change at any pulse repetition rate was negligible. Significant statistical difference in temperature changes during cavity preparation in dentin existed among three different pulse groups(p=0.001). While temperature rise was noticeable when the dentinal wall was perforated, actual change of temperature due to Er:YAG laser irradiation was not enough to compromise safety of dental pulp when irradiation was conjugated with appropriate water spray. Conclusively, it can be said that cavity preparation on enamel or dentin with an Er:YAG laser is performed safely without pulp damage if appropriate volume of water is sprayed properly over the irradiated site.

• Journal of Animal Environmental Science
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• v.1 no.2
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• pp.125-136
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• 1995

To use the earth heat for the pig housing, an underground heat exchanger has constructed in depth of 2.5m and 20m length. The temperature of the outlet air was max. 8 kelvin higher than that of inlet air in winter season. In spite of the -7$^{\circ}C$ outside temperature, it could keep the air temperature from the earth tube above zero degree. The heating performance was maximum in value of 3.25Wh/㎥ and average of 1.75Wh/㎥ by the airflow volume of 340㎥/h. The slope of relative humidity from outlet air has shown gentler than that of inlet air. By using the underground heat exchanger, it would be possible to prepare an relatively uniform relative humidity in the swine stalls. The temperatures on the earth, where PVC pipes are buried, have shown 10~12$^{\circ}C$ on March. This can reduce the difference between day and night temperature during this season by using the underground heat exchanger.

• Journal of Food Hygiene and Safety
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• v.5 no.4
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• pp.219-228
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• 1990

Whey proteins in milk were analyzed by polyacrylamide gel electrophoresis and compared with respect to electrophoregrams, densitograms and concentrations of whey proteins in raw and market milk classified according to 3 kinds of pasteurization by low temperature long time. high temperature short time and ultra-high temperature short time. Relative composition of major whey protein constituents such as bovine serum albumin, ${\alpha}\;-\;lactalbumin\;and\;{\beta}-lactoglobulin$ in raw milk were 3.71:11.44:84.85 and not affected by low temperature long time and high temperature short time pasteurization, even though there were the tendencies of some declining in the actual concentrations. But by ultra-high temperature short time pasteurization compositions of whey protein were changed to 0: 64.75: 35 in which reflected the disapprearance of bovine serum albumin and the extensive decrease of ${\beta}-lactoglobulin$. Storage of low temperature pasteurized milk at $5^{\circ}C$ resulted in a slight decrease of ${\alpha}\;-\;lactalbumin\;a\;{\beta}-lactoglobulin$, but storage at $25^{\circ}C$ did not make any changes until3rd days of storage. Most of whey proteins in high temperature short time pasteurized milk were not affected during storage at $5^{\circ}C\;and\;25^{\circ}C$, but bovine serum albumin and ${\alpha}\;-lactalbumin$ diminished in 2-3 days of storage. Whey proteins of milk treated with ultra-high temeperature were not affected during storage at $5^{\circ}C\;and\;25^{\circ}C$ except a slight decrease of ${\alpha}\;-lactalbumin$ in 2nd day of storage at $5^{\circ}C$.

• Fire Science and Engineering
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• v.20 no.1 s.61
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• pp.1-5
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• 2006

The spontaneous ignition of a flammable matter is a crucial factor for the prevention of a fire. The minimum ignition temperatures of Gasoline and Cenox in $1000{\mu}l$ of a sample were determined to be $340.5^{\circ}C\;and\;368.5^{\circ}C$ respectively. In addition when the time taken for ignition was 1.0 sec, the instantaneous ignition temperatures were $416^{\circ}C\;and\;427^{\circ}C$ respectively. Moreover, the changes in the minimum ignition temperature were small when less than 60 v/v% of Cenox was added, but the changes were great when 80 v/v% or more was added. Therefore, it is hypothesized that, when used as a fuel in the Gasoline engine, the ratio of the mixture of Cenox and Gasoline will be a very important factor.

• Tunnel and Underground Space
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• v.25 no.2
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• pp.144-154
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• 2015

Mechanical energy is accumulated in the object when stress is exerted on rock specimens, and the failure is occurred when the stress is larger than critical stress. The accumulated energy is emitted as various forms including physical deformation, light, heat and sound. Uniaxial compression strength test and point load strength test were carried out in low temperature environment, and thermal variation of rock specimens were observed and analyzed quantitatively using thermal infrared camera images. Temperature of failure plane was increased just before the failure because of concentration of stress, and was rapidly increased at the moment of the failure because of the emission of thermal energy. The variations of temperature were larger in diorite and basalt specimens which were strong and fresh than in tuff specimens which were weak and weathered. This study can be applied to prevent disasters in rock slope, tunnel and mine in cold regions and to analyze satellite image for predicting earthquake in cold regions.

• Fire Science and Engineering
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• v.34 no.4
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• pp.45-51
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• 2020

The aim of this study is to investigate the gas temperature and velocity during sprinkler activation considering the fire growth scenario based on the thermal response model of the sprinkler. The fire source is assumed to have time square fire growth scenarios with a maximum heat release rate of 3 MW. Eight types of standard and fast-response sprinkler heads with an operating temperature range of 65-105 ℃ and a response time index range of 25-171 m^1/2s^1/2 were adopted. The temperature difference between the gas stream and the sensing element of the sprinkler head decreased as the fire growth slowed down, and the RTI value decreased. The overall gas temperature and velocity conditions predicted using the FDS model at sprinkler activation were in reasonable agreement with those of standard test conditions of the sprinkler head response. However, the sprinkler head could be activated at lower limits of gas temperature and velocity under the current test conditions for a slowly growing fire scenario.