• Journal of the Korean Society for Heat Treatment
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• v.6 no.4
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• pp.213-222
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• 1993

This research was performed to investigate the transformation behavior and shape memory effect of Cu-13.5Al-4.5Ni(wt%) alloy with various aging temperature and time. The results obtained in this study are as follows: Transformation temperature was very increased when aging temperature is at $250^{\circ}C$. The variation of transformation temperature in first reverse transformation cycle and second was very significant, but there was little difference in case of 2nd and 3rd. Transformation temperature at various aging temperature was increased with increasing of aging temperature and time. Microvickers hardness was increased with increasing of aging temperature and time. It was found that ${\alpha}$ and ${\gamma}_2$ phase were created by aging of long time at high temperature.

• International Journal of Automotive Technology
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• v.1 no.2
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• pp.71-77
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• 2000

High temperature materials in service are subjected to mechanical damage due to operating load and metallurgical damage due to operating temperature. Therefore, when designing or assessing life of high temperature components, both factors must be considered. In this paper, the effect of tensile hold time on high temperature fatigue crack growth and long term prior thermal aging heat treatment on creep rupture behavior were investigated using STS 316L and STS 316 austenitic stainless steels, which are widely used for high temperature components like in automotive exhaust and piping systems. In high temperature fatigue crack growth tests using STS 316L, as tensile hold time increased, crack growth rate decreased in relatively short tensile hold time region. In long term aged specimens, cavity type microcracks have been observed at the interface of grain boundary and coarsened carbide.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.279-284
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• 2011

The objective of this study was to evaluate the effects of storage temperature and time on the quality parameters of eggs from laying hens at peak production. A total of 576 eggs were obtained from Lohmann Light-Brown hens, which were collected 3 times when the hens were 26, 27, and 28 weeks old. The fresh eggs were collected and measured within 2 h of being laid. Samples of 48 eggs each were stored in chambers for 2, 5, or 10 d inside a refrigerator ($5^{\circ}C$), at room temperature ($21^{\circ}C$), and at a high temperature ($29^{\circ}C$). As the storage temperature and time increased, egg weight, percentage of albumen, Haugh unit (HU), and yolk color significantly (p<0.001) decreased. In addition, egg shell weight, shell percentage, and albumen weight significantly (p<0.001) decreased with storage time. Yolk weight, yolk percentage, and albumen pH significantly (p<0.001) increased with increasing storage temperature, and yolk pH significantly (p<0.001) increased with increasing storage time. When the storage temperature was increased to $29^{\circ}C$, egg weight loss dramatically increased from 1.74 to 3.67% at 5 and 10 d of storage time, respectively. With the exception of the $5^{\circ}C$ storage temperature, HU dramatically decreased according to storage time and temperature, decreasing from 91.3 to 72.63 at $21^{\circ}C$ and from 87.62 to 60.92 at $29^{\circ}C$ during 10 d of storage; however, this decline was not found at $5^{\circ}C$. A rapid increase in albumen alkalinity was observed even after just 2 d of storage regardless of the storage temperature. Interactions between storage time and temperature were significant (p<0.001) with respect to egg weight loss, egg shell weight and percentage, albumen weight and percentage, yolk weight and percentage, albumen and yolk pH, HU, and yolk color. The results of the current study indicated that eggs from laying hens at peak production had significant deterioration of internal quality with increasing storage temperature and time. The results suggest that egg weight loss, albumen pH, and HU are parameters that are greatly influenced by the storage temperature and time of eggs from hens at peak laying.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.5 no.1
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• pp.33-45
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• 1998

The aim of this study was to investigate what is the most accurate and quick temperature measurement among rectal, auxiliary and tympanic routes. The body temperatures of 86 preform infants in incubators, a controlled environment, were measured at three different sites. The measurements were taken to examine the accuracy of the temperatures, proper nursing time for measuring the temperatures and the validity of fever detection. The results were as follows : 1. The mean temperature was significantly lower in the auxiliary site($36.71^{\circ}C$) and higher in the tympanic site($37.27^{\circ}C$) than in the rectal site($37.03^{\circ}C$). 2. The mean nursing time for measuring body temperature was significantly longer in the auxiliary site(171.65 seconds) and shorter in the tympanic site(17.70 seconds) than in the rectal site(83.33 seconds). 3. The nursing time for measuring body temperature included the time needed for preparation, measuring, as well as the post-measuring time. It was found that the time required to prepare for measuring the temperature of the rectal site was significantly longer than for other sites. In addition, the time needed to measure the temperature of the auxiliary site was significantly longer than in the other sites. Finally, the nursing time needed for measuring the auxiliary temperature(171.65 seconds) was the longest among the three sites whereas the nursing time for the tympanic site was the shortest(17.70 seconds). 4. Rectal temperature was significantly correlated to the tympanic(r=0.67) and auxiliary temperatures(r=0.69). Tympanic temperature was also significantly correlated to the auxiliary temperature(r=0.74). 5. The sensitivity, specificity, positive and negative predictive values of tympanic temperatures for detecting fever were 1.00, 0.80, 0.24, and 1.00, respectively. Those for the auxiliary temperatures were 0.00, 0.99, 0.00, and 0.94, respectively. Thus the level of fever detection was lower in the auxiliary temperatures than in tympanic temperatures. The above findings indicate that the tympanic method of temperature measurement offers a useful alternative to conventional methods.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.5
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• pp.1227-1234
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• 1994

A cold spot temperature control system for the batch annealing furnace has been established in order to reduce energy consumption which is essential to improve productivity and stabilize the properties of products. A relationship between annealing cycle time and gas flow rate is developed and also for the variation of coil cold spot temperature with time during heating, and actual temperature measurements at mid-width of each coil during soaking. The results of the temperature variation effect on the cold rolled steel sheet batch annealing are as follows. (1) Cooling rate increasing gradually with increasing atmospheric gas flow, but heating rate is hardly increasing without atmospheric gas component change. (2) In case of short time heating, the slowest heating part is the center of B coil and in case of ling time heating, the low temperature point moves from the center of coil to inside coil. (3) The outside of top coil is the highest temperature point under heating, which becomes the lowest temperature point under cooling. (4) Soaking time determination depends on the input coil width, and soaking time for quality homogenization of 1214 mm width coil must be 2 hours longer than that of 914 mm width coil.

• Journal of the Korean Society for Heat Treatment
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• v.8 no.1
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• pp.65-74
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• 1995

This research was performed to investigate the effect of ageing on grain refinement of 82wt%Cu-13.5wt%Al-4.5wt%Ni-0.1wt% misch metal alloy with ageing temperature and time. The results obtained in this study are as follows; The variation of transformation temperature with ageing temperature had very influence on ageing time at $300^{\circ}C$. But it had not influence on ageing time at $100^{\circ}C$. The variation of transformation temperature after second reversed transformation cycle was not occured in martensitic phase ageing, but $M_s$ point was appeared equally with third reversed transformation cycle in parent phase ageing. The variation of $M_s$ point was not nearly with ageing time at $100^{\circ}C$ ageing temperature. But it was decreasing with ageing time at $300^{\circ}C$ ageing temperature and $A_s$ point was increasing with ageing time. Structure of parent phase ageing was being M18R martensitic and N2H martensitic phase. It was found that ${\alpha}$ and ${\gamma}_2$ phase were created by ageing of long time at $300^{\circ}C$ ageing temperature.

• Journal of the Korean Society of Safety
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• v.6 no.4
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• pp.34-44
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• 1991

In this study, the general solution of heat balance equation including conductive heat loss were suggested and were determined the constants with the results of experiment in hot tunnel in order to derive the general equation for the response time and to investigate the response time index which represent the characteristics of response of sprinkler head in actual fires. Two types of test were considered, the plunge test, in which the air temperature is represented by a step function, and the ramp test, in which the air temperature increases at a constant rate. As a result, simple equations were derived, which can be predicted the response time for the ramp type fire with the rate of temperature rise and gas velocity, for the plunge type fire with temperature and gas velocity. Also other useful data, such as the effective temperature, time constant, response time index and conduction parameter were obtained.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.12
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• pp.821-827
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• 2010

Study on the performance characteristics of the solar hybrid system with heat pump operating temperature during winter season has performed by using an experimental test. The system performance and operating characteristics with the heat pump operating temperature, hour and load condition were investigated and analyzed. As a result, the hot water temperature was significantly affected by the heat pump operating temperature at the morning(time 1) and noon(time 2). However, hot water temperature was set by the radiation quality and collecting operation hour at the afternoon(time 3). In addition to the solar fraction was decreased for the high heat pump operating temperature because the heat pump operated with a long operating time and short operating period.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.58-59
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• 2018

In this study, firing experiments were carried out to confirm the foamability of the expansive shale collected from the local area. When expansive shales are subjected to high temperature heat, gas is generated inside and voids are formed. Due to this phenomenon, shale is used as a raw material for lightweight aggregate. Experiments were carried out with different plastic temperature and residence time to find the appropriate plastic temperature for this expansive shale. As a result, the higher the plastic temperature, the more the surface viscosity increased and the gas generated inside were retained. Resulting in a number of internal voids. However, even if the plastic temperature or the medium temperature is high, it is confirmed that sufficient gas is not generated when the residence time is shortened.

• Journal of The Korean Astronomical Society
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• v.39 no.4
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• pp.81-87
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• 2006

A relation between temperature and time has been constructed in the self-consistent model(SCM). This relation is used to calculate the a CMBR temperature. This temperature has been found to be 2.9K. The temperature gradient of microwave background radiation(CMBR) is calculated in the Self Consistent Model. Two relations between Hubble parameter and time derivative of the temperature, have been presented in two different cases. In the first case the temperature is treated as a function of time only, while in the other one, it is assumed to be a function in time and solid angle, beside the assumption that the universe expands adiabatically.