• Journal of Animal Reproduction and Biotechnology
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• v.34 no.3
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• pp.173-182
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• 2019

This study was performed to evaluate the effect of heat stress on the status of physiological responses, blood parameter, serum T3 and cortisol, and heat shock proteins (HSP 27, 70, and 90) of Hanwoo cattle. Six Hanwoo steers (242.8 ± 7.2 kg of BW) were housed in the climate-controlled respiration chambers. The experiment consisted of 7 days (control; 0 day) at thermoneutral (air temperature (Ta) of 15℃ and relative humidity (RH) of 60%; temperature-humidity index (THI) = 64), and by 3 and 6 days (treatment groups) at heat stress (Ta of 35℃ and RH of 60%; THI = 87). Body temperature of each parts (frank, rump, perineum and foot) and rectal temperature elevated in heat stress groups (3 days and 6 days) than the control group (0 day). Respiration rates increased in 3 days and 6 days (88.5 ± 0.96 bpm and 86.3 ± 0.63 bpm, respectively) from 0 days (39.5 ± 0.65 bpm). Feed intake significantly decreased in heat stress groups (3 days and 6 days, 3.7 ± 0.14 kg and 4.0 ± 0.15 kg, respectively) than the control group (0 day, 5.0 ± 0.00 kg). In addition, final BW significantly decreased in heat stress groups (3 days and 6 days, 211.8 ± 4.75 kg and 215.5 ± 3.50 kg, respectively) than the control group (0 day, 240.0 ± 25.00 kg). However, heat stress has no significant effect on blood parameter, serum T3 and cortisol. Nevertheless, heat stress increased HSPs mRNA expression in liver tissue, and serum concentration of HSPs. Despite Hanwoo cattle may have high adaptive ability to heat stress, our results suggested that heat stress directly effect on body temperature and respiration rate as well as serum and tissue HSPs. Therefore, we are recommended that HSPs could be the most appropriate indicators of Hanwoo cattle response to heat stress.

• Journal of Food Hygiene and Safety
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• v.39 no.1
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• pp.1-8
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• 2024

Salmonella is widely prevalent in various environments and often detected in poultry. In this study, we investigated the effect of heat treatment on heat resistance via measuring the minimum inhibitory concentration (MIC) values of antibiotics after 3, 6, and 9 min of acclimatization to mild heat treatment (50℃) against 11 strains of Salmonella spp. Most strains were susceptible to chloramphenicol and their MIC values were maintained or decreased after heat treatment compared to the control. Most control and heat-treated strains showed susceptibility or intermediate resistance to ciprofloxacin. All isolates were susceptible to tetracycline, with the MIC increasing after heat treatment for S. Gaminara BAA 711. In the control, three, two, and six strains were susceptible, intermediate resistance, and resistant to gentamicin, respectively. Among them, S. Heidelberg ATCC 8326 had an intermediate MIC breakpoint of 8 ㎍/mL in the control; however, after 3 and 9 min of heat treatment, the MIC value increased to 16 ㎍/mL, indicating it to be resistant. The results of this study revealed the changes in antibiotic resistance in some of the 11 strains after heat treatment. MIC values of ciprofloxacin increased when S. Montevideo BAA 710 was heat treated for 3 and 6 min. MIC values of gentamicin increased after 3 min of heat treatment for S. Enteritidis 109 D1 and after 3 and 9 minutes of heat treatment for S. Heidelberg ATCC 8326. The MIC value of tetracycline increased when S. Gaminara BAA 711 was heat treated for 6 and 9 min.

• International journal of advanced smart convergence
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• v.7 no.2
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• pp.38-46
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• 2018

This study proceeded an experiment that can increase such physiological properties of heated radish extract. During the extraction of radish, including the byproduct, an increase in antioxidant properties of radish according the heating temperature was performed. Upon the extracts of radish bark and radish green extract(mucheong), the physiological functionalities and antioxidant activity were investigated. As a result, the color of radish ethanol extract in dependence of heating temperature, showed light brown color at low heating temperature and black color from $150^{\circ}C$. The total polyphenol content significantly increased as a result of heat treatment; 6.7 times and 22 times higher than the control at $110^{\circ}C$ and $150^{\circ}C$, respectively. DPPH radical scavenging ability and antioxidant property increased with increasing heating temperature; in comparison to heat-treated radish at $110^{\circ}C$ and $150^{\circ}C$, $IC_{50}$ decreased by 1/22 times. $IC_{50}$ of the control was 23times higher than $150^{\circ}C$ heat treated radish (Control $IC_{50}$:130.305). According to the graph that represents ABTS activity, antioxidant activity increased in dependence of heat treatment likewise to the total polyphenol content and DDPH radical scavenging activity. Upon heat treatment at $150^{\circ}C$, antioxidant activity in consequence of ABTS assay increased 23 times higher than the control.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.388-391
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• 2017

In this study, heat transfer analysis of variable thrust control system have been conducted by using commercial CFD code and FEM code. We Carried out computational fluid dynamics analysis to obtain the temperature and convective heat transfer coefficient of hot gas of variable thrust control system. Data are used as boundary condition for heat transfer analysis using mapping method. Temperature of O-ring for sealing was predicted

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.12
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• pp.1676-1683
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• 2001

An experimental study on condensation heat transfer characteristics of helically coiled spiral tubes was performed. The refrigerant is R-113. A refrigerant loop was established to measure the condensation heat transfer coefficients. Experiments were carried out uniform heat flux of 15 kw/m$^2$, refrigerant quality of 0.1∼0.9, curvature ratio of 0.016, 0.025 and 0.045. The curvature of a coil was defined as the ratio of the inside diameter of the tube to the diameter of the bending circle. To compare the condensation heat transfer coefficients of coiled spiral tubes, the previous results on coiled plain tubes and straight plain tubes were used. The results shows that the condensation heat transfer coefficients of coiled spiral tubes largely increase, as increasing Re and quality, compared to those of coiled plain tubes and straight plain tubes. As increasing degree of subcooling, however, the condensation heat transfer coefficients on coiled spiral tubes decrease. It is found that the heat transfer enhancement is more better than coiled plain tubes and straight plain tubes, as increasing curvature ratio.

• Journal of Oriental Medical Thermology
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• v.1 no.1
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• pp.38-46
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• 2002

1. Objectives Among many symptoms that the climacteric patients complain of, the major subjective symptom is both heat in the upper part and cold in the lower part of the body(e.g foot, knee, and leg). We use DITI as a method to prove the symptoms of climacteric patients such as both heat in the upper part and cold in the lower part of the body, diagnose these symptoms, and follow up the progress of the clinical treatments. 2. Subjects and Methods We compare the subcutaneous heat of the climacteric patients with the symptom of heat in the upper part and cold in the lower part of the body with young women without any specific disease. The age distribution of the experimental group is 28 patients in 40's, and 22 in 50's. The mean age of the experimental group is $48.5{\pm}4.25$. The age distribution of the control group is 17 patients in teen, 26 in 20's, 7 in 30's. The mean age of the control group is $23.31{\pm}6.45$. We measure the subcutaneous heat on the cheeks, upper arms, palms, thighs, knees, dorsum pedis, lower back, hip, upper abdomen, lower abdomen of both groups and analyse the results. 3. Statistical methods All the results are statiscally analysed using student T-test of Microsoft Exel program. Statistically significant value by the analysis of variance procedure is P<0.05. 4. Results 1. The subcutaneous heat of the whole body of the experimental group shows hypothermia compared with control group, and the hypothermic pattern gets severe on the periphery. ${\Delta}T$ between the right and left side of the body in experimental group is larger than that of control group. 2. ${\Delta}T$ between the cheeks and the hypogastric in the experimental group is significantly larger than that of the control group, which shows cold face. 3. ${\Delta}T$ between the upper arms and the palms in the experimental group is significantly larger than that of the control group, which shows cold hand. 4. ${\Delta}T$ between the thighs and the knees in the experimental group is significantly larger than that of the control group, which shows cold knee. 5. ${\Delta}T$ between the thighs and the feet in the experimental group is significantly larger than that of the control group, which shows cold foot. 6. ${\Delta}T$ between the hip and the lower back in the experimental group is significantly larger than that of the control group. That shows the Lower back is warmer than the hip. 7. ${\Delta}T$ between the upper and the lower abdomen in the experimental group is significantly larger than that of the control group, which shows cold hypogastric.

• Journal of Biosystems Engineering
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• v.27 no.1
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• pp.39-44
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• 2002

In order to obtain the information of bio-environment control, the thermal characteristics of soil in the greenhouse heated by the heat pump and latent heat storage system were experimentally analyzed. The experimental systems were composed of the greenhouse with a heat pump and a latent heat storage system (system I), the greenhouse with a heat pump (system II), the greenhouse with a latent heat storage system (system III), and the greenhouse without auxiliary heating system (system IV). The thermal characteristics experimentally analyzed in each system were temperature of soil layers, soil heat storage and release, soil heat capacity and soil heat storage ratio. The results could be summarized as follows. 1. Time to reach the highest temperature at 20cm deep in soil layers of the crop routs in case of system I was shown to be delayed by 6 hours in comparison to the time of the highest temperature at the soil surface. 2. In the clear winter days, the stored heat capacity values fur the system I and the system II were shown to be 22.3% and 11.0% higher than the released heat capacity respectively, and the stored heat capacity values for the system III and the system IV were shown to be 6.2% and 29.6% lower than the released heat capacity respectively This confirms that the system I provided the best heat storage effect. j. The heat quantity values stored or released were shown to be highest at 5 cm depth of soil layers. And it was reduced with increasing of depth of soil layers until 20 cm and was not changed under the soil layer of 20 cm depth. 4. The heat absorption rates of soil, the ratio between supplied and stored heat energy, fur both the system I and system II were lower than 23%.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.5
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• pp.549-556
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• 1997

The inverse heat conduction problems is the calculation of surface heat transfer coefficients by utilizing measured temperature. The numerical technique of finite element analysis and optimizition is introduced to calculate temperatures and heat transfer coefficients. The calculated heat transfer coefficients and temperature distribution are good agreement with the results of direct analysis. The inverse method has been applied to the control valve of nuclear power plant.

• Journal of Hydrogen and New Energy
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• v.10 no.1
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• pp.19-26
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• 1999

The effectiveness of a double-tube heat exchanger has been investigated experimentally. This problem is of particular interest in the design of the heat exchanger in a hydrogen liquefaction system. Temperature, pressure, and mass flow rate for hydrogen were measured both in inner tube and in annulus of a double-tube heat exchanger. The effectiveness could be evaluated from the measured temperature and mass flow rate. It is found that the effectiveness increases with an increase in the heat transfer area of a double-tube heat exchanger and with a decrease of the heat capacity ratio. But the increase rate of the effectiveness decreased with a decrease of the heat capacity ratio. Therefore, it is presented that a criterion for selecting the heat exchanger length and heat capacity ratio to obtain the effectiveness required in a hydrogen liquefaction system.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.5
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• pp.51-60
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• 2006

In order to examine the heat transfer characteristic of a soil warming system and effects of soil warming on the greenhouse heating load, control experiments were performed in two greenhouses covered with double polyethylene film. One treated the soil warming with an electric heat wire and the other treated a control. Inside and outside air temperature, soil temperature and heat flux, and heating energy consumption were measured under the set point of heating temperature of $5,\;10,\;15,\;and\;20^{\circ}C$, respectively. Soil temperatures in a soil warming treatment were observed $4.1\;to\;4.9^{\circ}C$ higher than a control. Heating energy consumptions decreased by 14.6 to 30.8% in a soil warming treatment. As the set point of heating temperature became lower, the rate of decrease in the heating energy consumptions increased. The percentage of soil heat flux in total heating load was -49.4 to 24.4% and as the set point of heating temperature became higher, the percentage increased. When the set point of heating temperature was low in a soil warming treatment, the soil heat flux load was minus value and it had an effect on reducing the heating load. Soil heat flux loads showed in proportion to the air temperature difference between the inside and outside of greenhouse but they showed big difference according to the soil warming treatment. So new model for estimation of the soil heat flux load should be introduced. Convective heat transfer coefficients were in proportion to the 1/3 power of temperature difference between the soil surface and the inside air. They were $3.41\;to\;12.42\;W/m^{2}^{\circ}C$ in their temperature difference of $0\;to\;10^{\circ}C$. Radiative heat loss from soil surface in greenhouse was about 66 to 130% of total heating load. To cut the radiation loss by the use of thermal curtains must be able to contribute for the energy saving in greenhouse.