• Journal of the Korean Society for Railway
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• v.7 no.1
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• pp.55-59
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• 2004

Composite materials were used widely due to merit of light weight, low maintenance cost and easy installation. But it is the cause of enormous casualties to men and properties because of weak about the fire. Particularly, it is more serious in case of subway train installed composite materials. For this reason, experimental comparison has been done fur measuring heat release rate(H.R.R) and smoke production rate(S.P.R) of interior panels of electric motor car using cone calorimeter. A high radiative heat flux of 50kW/㎡ was used to bum out all materials and to simulate the condition of fully developed fire case in the tests. It was observed that Heat Release Rate and Smoke Production Rate curves were dependent on the kinds of the interior materials. From the heat release rate curves, the sustained ignition time, peak heat release rate and total heat release rate were deduced, These data are useful in classifying the materials by calculating two parameters describing the possibility to flashover.

• Bulletin of the Korean Chemical Society
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• v.14 no.6
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• pp.700-704
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• 1993

The photocatalytic alanine and hydrogen production reaction were studied by using CdS as a semiconductor photocatalysts. The rate of alanine and hydrogen production depends strongly on the temperature in heat treatment of CdS powder. In particular, the rate of alanine production, which was observed using Pt/CdS(A)-(CdS from Mitsuwa), was increased about six times than that of using Pt/CdS(B)-(CdS from Furruchi) under the same heat treatment condition at 500$^{\circ}$C. And the photocatalytic activity for alanine production using bare CdS(A) or Pt/CdS(A) was almost same with increasing temperature in heat treatment in the range of 100-600$^{\circ}$C. From X-ray diffraction data and photoluminescence spectrum, we conclude that the crystal structure changes of CdS(A) or strong interaction at interface of Pt and CdS contribute to increasing the rate of alanine and hydrogen production reaction.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.295-300
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• 2003

Experimental comparison was done for measuring Heat Release Rate and Smoke Production Rate of electric motor car's interior panels using cone calorimeter. Radiative heat flux of $50kW/m^2$ was used to simulate the condition of fully developed fire case in the tests. It was observed that Heat Release Rate and Smoke Production Rate curves were shown differently according to interior materials. From experiment's results we can deduce that materials having higher rate of heat release smolder more smoke. It needs to establish fire risk propensity of each material and to set up the standards urgently.

• Animal Bioscience
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• v.37 no.6
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• pp.1121-1129
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• 2024

Objective: Objective of the study was to reduce heat stress in Murrah buffaloes and maintain their milk production and other vital functions during heat stress. Methods: A total of 21 dyads of calf-mother Murrah buffalo were selected for the study and equally divided in 3 treatment groups. First treatment group was restricted calf contact (RCC), second treatment group was fence line calf contact (FCC) and third treatment groups fence line calf contact and heat stress protection (FCC-HSP [time-controlled fan-fogger system] in the shed). Present study was conducted from April to mid-September 2021. Results: Maximum temperature and temperature humidity index in FCC-HSP shed were significantly (p<0.05) lower than that in FCC and RCC shed. Higher (p<0.05) mean daily milk yield in both the treatment groups FCC (10.36±0.30) and FCC-HSP (10.97±0.31) than RCC (8.29±0.41) was recorded. Though no significant difference between FCC and FCC-HSP in daily milk yield but FCC-HSP yielded 600 gm more milk than FCC. Pulse rate (PR) and respiration rate (RR) were lowest in FCC-HSP followed by FCC and RCC, respectively. Cortisol and prolactin levels were lower (p<0.05) in FCC-HSP followed by FCC and RCC, respectively. Conclusion: Hence, FCC along with heat stress ameliorative measures helped the buffaloes to be free of stress and maintain milk yield during heat stress period of the year in tropical conditions.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.181-184
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• 2000

The cooling rate of a bioreactor was measured to estimate the heat generation by microbial cultivation production. The estimated heat production was calculated from the varying temperature of cooling water. It was used for monitoring growth and specific metabolic events for microbial cultivations. Metabolic heat measured was also adopted for a control parameter for fed-batch cultivation.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.3
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• pp.293-298
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• 1991

A study was conducted to determine the effect of environmental temperature and level of food intake on plasma concentration of thyroid hormones. Three dairy heifers were used in an experiment which consisted of three levels of chamber temperature (10, 20 and $30^{\circ}C$) and three levels of food intake (100, 75 and 50% of recommended requirements). The analysis showed significant effects of environmental temperature on plasma triiodothyronine concentration, rectal temperature, respiration rate and heart rate but not on heat production. The range of plasma triiodothyronine was 2.51~1.79 ng/ml when the environmental temperature varied from 10 to $30^{\circ}C$. Effects of feed intake level were significant for heart rate and heal production. Heat production decreased from 25.9 to $20.0kJ/kg^{0.75}{\cdot}h$ when the TDN intake decreased from 66.3 to $35.1g/kg^{0.75}{\cdot}d$. There was no interactive effect of environmental temperature and feed intake level. Plasma triiodothyronine concentration decreased under high environmental temperature without any changes in heat production. The effects of environmental temperature and feed intake level on the physiological function of thyroid gland, as indicated by the relative circulating rate of thyroid hormones, were found to be clear.

• Journal of the Korean Society for Heat Treatment
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• v.34 no.6
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• pp.272-280
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• 2021

The influence of acetylene flow rates on the carburizing behavior of an AISI 4115 steel in 1 ton-class mass production-type vacuum carburizing furnace has been studied through microstructure, carbon concentration, hardness analyses. The AISI 4115 steels were carburized with various flow rates (20, 32.7, 60 l/min) and locations in the furnace (top, center, bottom) at 950℃. The acetylene flow rate played an important role in controlling the carburizing properties of carburized samples, such as effective case depth and uniformity carburizing according to location in the furnace. At an acetylene flow rate of 20 l/min, the carburized samples had a shallow average hardened layer (0.645 mm) compared to the target hardening depth (1 mm) due to low carbon flux and spatial uniformity of carburization (17.8%) in the furnace. At a flow rate of 60 l/min, the carburized samples showed an average hardened layer (1.449 mm) deeper than the target hardening depth and had the spatial uniformity of carburization (98.8%). In particular, at a flow rate of 32.7 l/min, the carburized samples had an average hardened layer (1.13 mm) close to the target hardening depth and had the highest carburizing uniformity (99.1%). As a result, an appropriate flow rate of 32.7 l/min was derived to satisfy the target hardening depth and to have spatial uniform hardened layer in the furnace.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.2
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• pp.275-279
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• 1993

A study using dairy heifers was conducted to determine the effect of environmental temperature on heat production differing in feed intake level. The design consisted of three levels of feed intake (low, medium and high) and two environmental chamber temperature (15 and $30^{\circ}C$) with four replications in each treatment. Rectal temperature (RT), respiration rate (RR), heart rate (HR) and heat production (HP) were then measured. At the both environmental temperature, RT, RR and HR increased with the increase in feed intake level. The RT and RR also increased with the elevation of environmental temperature. The HP of $30^{\circ}C$ was significantly higher (4.8-8.9%) than $15^{\circ}C$. The estimated metabolizable energy requirement for maintenance (MEm) was higher (p<0.05) at $30^{\circ}C$ ($554.7kJ/kg^{0.75}$ d) than $15^{\circ}C$ (464.9 kJ/kgd). It was suggested that the decreasing in productive efficiency under hot environmental conditions partly associated with the increase in HP, which associated with the change in heat loss mechanism from sensible path to evaporative path.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.9
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• pp.671-678
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• 2012

The objective of this study is to analyze theoretically the performance of an open air-cycle refrigeration system in which environmental concerns increase. The pressure ratio of the external compressor and efficiencies of the components that compose of the system are selected as important parameters. As the pressure ratio of the external compressor increases, the pressure ratio of the ACM compressor is determined high, the refrigerating temperature and capacity increase, the COP decreases, and the total entropy production rate increases. The effect of heat exchanger effectiveness and turbine efficiency on the performance are greater than that of the ACM compressor efficiency. Also the performance of the air-cycle refrigeration system with two heat exchangers has been enhanced like high COP and low total entropy production rate, compared to the system with one heat exchanger.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.8
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• pp.1273-1276
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• 1999

Several reports have indicated that a rectal temperature of buffaloes is easily influenced by their surroundings. To clarify an effect of changing environmental temperature on thermoregulatory responses of buffaloes, an environment with diurnal temperature changes of $25^{\circ}C$ to $35^{\circ}C$ was created using an artificial climate laboratory. Three swamp buffaloes and three Friesian cows were exposed to three different experimental periods as follows: Period 1 (constant temperature of $30^{\circ}C$, Period 2 (diurnally changing temperature) and Period 3 (diurnally changing temperature and fasting). Heat production, rectal temperature, respiration rate, heart rate and respiration volume were measured during each period. Rectal temperature of the buffaloes fluctuated diurnally with the changing temperature (Periods 2 and 3), but remained constant in cows. Mean heat production was significantly lower in buffaloes than in cows in Period 2 and 3. However, the maximum rectal temperature and the increment of heat production were not always lower in buffaloes than in cows during Period 2. These results show that a rectal temperature and heat production in buffaloes are markedly influenced by the diurnal changes in temperature. Compared with Bos Taurus cows, the differences may be attributed to the physiological features of buffaloes including a high heat conductivity of their bodies and an lower heat production.