• Restorative Dentistry and Endodontics
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• v.26 no.5
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• pp.387-392
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• 2001

When cavity floor is near the pulp, polymerization of light-activated restorations results in temperature increase. This temperature increase cause by both the exothermic reaction process and the energy absorbed during irradiation. Therefore instating base is required. Most frequently used insulating base is glass ionmer. The purpose of this study was to evaluate intrapulpal temperature changes of glass ionomer according to various curing intensity and curing time. Caries and restoration-free mandibular molars extracted within three months were prepared Class I cavity of 3$\times$6mm with high speed handpiece. 1mm depth of dentin was evaluated with micrometer in mesial and distal pulp horns. Pulp chambers were filled with 37.0$\pm$0.1$^{\circ}C$ water to CEJ. Chromium-alumina thermocouple was placed in pulp horn for evaluating of temperature changes. glass ionomer material was placed in 2mm. total curing time was 40s: continuous 40s, intermittent 20s, intermittent 10s. Glass ionomer material was cured with 300mW/$\textrm{cm}^2$, 550mW/$\textrm{cm}^2$ light curing unit. The results were as follows : 1. Temperature in pulp increased as curing unit power is increased. 2. Temperature in pulp more increased continuous emission than intermittent emission.

• Plant Resources
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• v.8 no.3
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• pp.217-224
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• 2005

We tested the hypothesis that alpine plants have special physiological and biochemical mechanisms in addition to their structural adaptation in order to survive under extreme conditions. The photosynthetic organs of Pinus pumila were used to examine the seasonal changes in sugar concentration, antioxidative enzyme, and lipid peroxidation. The concentrations of sucrose, glucose, fructose and reducing sugar were the highest in the leaves in April. But sugar contents in buds and inner barks did not respond sensitively on temperature change. Meanwhile superoxide dismutase (SOD) activity responded sensitively on the change of temperature and SOD in all tissues maintained high activity in April. Meanwhile anthocyanin content increased rapidly in June but the increase of anthocyanin content was not enough to prevent their tissues from the damage by the exposure of high temperature or other stress. In conclusion, under low temperature condition, P. pumila increased the concentration of soluble sugars and SOD activity in their tissues in order to overcome extreme environmental condition. But in summer, these stress defense system against high temperature might be disturbed slightly. This results in the increase of malondialdehyde (MDA) contents in three tissues by lipid peroxidation.

• Magazine of the Korean Society of Agricultural Engineers
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• v.15 no.4
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• pp.3137-3146
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• 1973

This study was to investigate the effects of compaction, compressive strength and Atterberg limits in accordance with the temperatures changes. It was conducted on four soils-KJ, JJ, MH, SS-at temperatures of -1, 1, 3, 5, 7, 10, 15, 19, $22^{\circ}C$. These tests were obtained the maximum dry density and the optimum moisture content of four soils in accordance with temperature changes by using distilled water and $CaCl_2$ 10% solution, and were put to the compressive strength tests on remolded specimens of soils compacted at the optimum moisture content. The result of the study can be summarized as follows; The maximum dry density increased with an increase in temperature, and the use of $CaCl_2$ 10% solution had higher maximum dry density than distilled water. The optimum moisture content decreased with an increase in temperature, and the use of $CaCl_2$ 10% solution had lower optimum moisture content than distilled water. The maximum compressive strength was shown high peak from $7^{\circ}C\;to\;15^{\circ}C$, and the use of $CaCl_2$ 10% solution had higher maximum compressive strength than distilled water. The liquid limit and plasticity index decreased with an increased in temperature. It is estimated that the use of $CaCl_2$ 10% solution can lower the minimum compacted temperature from $2^{\circ}C\;to\;4^{\circ}C$ in low temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.718-721
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• 2004

The $(Sr_{0.9}Ca_{0.1})TiO_3$(SCT) thin films are deposited on Pt-coated electrode$(Pt/TiN/SiO_2/Si)$ using RF sputtering method at various substrate temperature. The optimum conditions of RF power and $Ar/O_2$ ratio were 140[W] and 80/20, respectively. Deposition rate of SCT thin films was about $18.75[{\AA}/min]$. The crystallinity of SCT thin films were increased with increase of substrate temperature in the temperature range of $100\sim500[^{\circ}C]$. The dielectric constant of SCT thin films were increased with the increase of substrate temperature, and changed almost linearly in temperature ranges of $-80\sim+190[^{\circ}C]$. The current-voltage characteristics of SCT thin films showed the increasing leakage current as the substrate temperature increases.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.6
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• pp.91-97
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• 2018

Chemical mechanical polishing(CMP) realizes a surface planarity through combined mechanical and chemical means. In CMP process, Preston equation is known as one of the most general approximation of the removal rate. Effects of pressure and relative speed on the mechanical property of Cu CMP has been investigated. On the other hand, The amount of abrasion also increased with changes in pressure and speed, resulting in a proportional increase of temperature during CMP. Especially this temperature is an important factor to change chemical reaction in a Cu CMP. However, when the slurry temperature became higher than $70^{\circ}C$, the removal rate went lower due to abrasives aggregation and scratching occurred on the Cu film. Therefore, it was found that the slurry temperature should not exceed $70^{\circ}C$ during Cu CMP. Finally, authors could increase the pressure, speed and slurry temperature up to a ceratin level to improve the removal rate without surface defects.

• Korean Journal of Materials Research
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• v.32 no.4
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• pp.181-185
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• 2022

In this study, phase-pure titanium dioxide TiO₂ ceramics are sintered using standard high-temperature solid-state reaction technique at different temperatures (1,000, 1,100, 1,200, 1,300, 1,400 ℃). The effect of sintering temperature on the densification and impedance properties of TiO₂ ceramics is investigated. The bulk density and average grain size increase with the increase of sintering temperature. Impedance spectroscopy analysis (complex impedance Z^* and complex modulus M^*), performed in a broad frequency range from 100 Hz to 10 MHz, indicates that the TiO₂ ceramics are dielectrically heterogeneous, consisting of grains and grain boundaries. The complex impedance Z^* -plane indicates the resistance of grains of the TiO₂ ceramics increases with increasing sintering temperature, while that of grain boundaries develops in the opposing direction. The complex modulus M^*-plane shows a grain capacitance that seems to be independent of the sintering temperature, while that of the grain boundaries decreases with increasing sintering temperature. These results suggest that different sintering temperatures have effects on the microstructure, leading to changes in the impedance properties of TiO₂ ceramics.

• Journal of ILASS-Korea
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• v.28 no.2
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• pp.89-96
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• 2023

This study presents a numerical simulation investigating hydrodynamic characteristics of high-temperature hydrocarbon aviation fuel injected through a plain orifice injector. The analysis encompassed the temperature range up to the critical point, and the obtained results were compared with prior experimental observations. The analysis unveiled that the injector's exit pressure remains equivalent to the ambient pressure when the fuel injection temperature is below the boiling point. However, when the fuel temperature surpasses the boiling point, the exit pressure of the injector transitions to the saturated vapor pressure corresponding to the fuel injection temperature. Consequently, the exit pressure of the injector increases in tandem with the rapid increase of the saturation vapor pressure due to escalating fuel temperatures. This rise in the exit pressure necessitates a proportional increase in fuel injection pressure to ensure a fixed fuel mass flow rate. Furthermore, the investigation revealed that the discharge coefficient obtained by applying the exit pressure instead of the ambient pressure did exhibit no decrease, but rather was maintained at a nearly constant value, comparable to its level below the boiling point.

• Geomechanics and Engineering
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• v.35 no.6
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• pp.593-601
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• 2023

In this paper, an analytical solution of large-strain cylindrical cavity expansion in compaction grouting problem under temperature field is given. Considering the stress increment caused by temperature, the analytical solution of cavity expansion under traditional isothermal conditions is improved by substituting the temperature stress increment into the cavity expansion analysis. Subsequently, combined with the first law of thermodynamics, the energy theory is also introduced into the cylindrical cavity expansion analysis, and the energy dissipation solution of cylindrical cavity expansion is derived. Finally, the validity and reliability of solution are proved by comparing the results of expansion pressure with those in published literatures. The results show that the dimensionless expansion pressure increases with the increase of temperature, and the thermal response increases with the increase of dilation angle. The higher the exothermic temperature of grouting slurry, the greater the plastic deformation energy of the surrounding soil, that is, the greater the influence on the surrounding soil deformation and the surrounding environment. The proposed solution not only enrich the theoretical system of cavity expansion, but also can be used as a theoretical tool for energy geotechnical engineering problems, such as CPT, nuclear waste disposal, energy pile and chemical grouting, etc.

• Environmental Analysis Health and Toxicology
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• v.26
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• pp.9.1-9.9
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• 2011

Objectives: In order to evaluate which temperature index is the best predictor for the health impact assessment of heat stress in Korea, several indexes were compared. Methods: We adopted temperature, perceived temperature (PT), and apparent temperature (AT), as a heat stress index, and changes in the risk of death for Seoul and Daegu were estimated with $^1{\circ}C$ increases in those temperature indexes using generalized additive model (GAM) adjusted for the non-temperature related factors: time trends, seasonality, and air pollution. The estimated excess mortality and Akaike's Information Criterion (AIC) due to the increased temperature indexes for the $75^{th}$ percentile in the summers from 2001 to 2008 were compared and analyzed to define the best predictor. Results: For Seoul, all-cause mortality presented the highest percent increase (2.99% [95% CI, 2.43 to 3.54%]) in maximum temperature while AIC showed the lowest value when the all-cause daily death counts were fitted with the maximum PT for the $75^{th}$ percentile of summer. For Daegu, all-cause mortality presented the greatest percent increase (3.52% [95% CI, 2.23 to 4.80%]) in minimum temperature and AIC showed the lowest value in maximum temperature. No lag effect was found in the association between temperature and mortality for Seoul, whereas for Daegu one-day lag effect was noted. Conclusions: There was no one temperature measure that was superior to the others in summer. To adopt an appropriate temperature index, regional meteorological characteristics and the disease status of population should be considered.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.169-173
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• 1997

In this paper, auto measuring system for evaluating sensing reliability of infrared temperature sensors is developed. A developed system is composed of temperature controller, measuring sysytem and operating S/W. A constant temperature control of a chamber is accomplished by multi-heater using PI control. It is shown that the control resulte of temperature are well followed to the desired temperature value. The developed untegrated measuring system will increase reliability and productivity of products.