• 동력기계공학회지
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• 제19권6호
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• pp.47-53
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• 2015

Korea is the geographic location during the summer, the temperature rising to $35^{\circ}C$ and winter temperature is $-15^{\circ}C$ to reduce the air temperature changes, such as relatively large compared to other countries. This increase or decrease of the harmful exhaust gas discharged from automobile substantially inconvenience a significant impact on the active side of the car engine temperature and exhaust gas reducing device receives a large impact on the atmospheric temperature is regulation to be different. However, domestic vehicle emissions test temperature of $20{\sim}30^{\circ}C$ is it does not reflect this situation the actual test temperature to accurately measure the exhaust gas volume of the vehicle is difficult. In this study, domestic automobile exhaust gas test conditions of a test temperature $20{\sim}30^{\circ}C$ various temperatures, including (35, 25, 0, -7, -15, $-25^{\circ}C$) under the two vehicles (2.0L MPI, 2.4 L GDI) as was discussed with respect to the exhaust gas characteristics of the vehicle according to the ambient temperature gas. As a result, domestic emissions test temperature of $25^{\circ}C$ than average conditions were temperature decreases greenhouse gas emissions and increase overall increased by up to 15 times higher. Air temperature and the engine exhaust gas inconvenience a direct effect on the activation temperature required in the reduction unit is determined to be an increase of emissions and greenhouse gases, and also an increase in the variety of lubricants based lubricating and viscosity reduction, such as the engine oil due to the low temperature of these result It is considered that shows the.

• 한국지구과학회지
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• 제27권2호
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• pp.188-197
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• 2006

1924년부터 2004년까지 제주관측지점 자료를 이용하여 제주의 기온과 강수량의 변동 특성을 조사하였다. 지난 81년 동안 연평균 기온은 $0.02^{\circ}C/year$ 정도로 증가하였으며 1980년 이후에는 $0.05^{\circ}C/year$로 이전보다 큰 폭으로 증가하였다. 최저기온의 증가가 최고기온 증가보다 크게 나타나 결과적으로 최저기온의 상승이 평균기온의 상승을 유발한 것으로 보인다. 기온과 강수의 특이기후 발생빈도 또한 조사하였다. 최고기온 특이값 빈도에 대한 기온편차는 지구온난화경향과 더불어 1980년대에 증가하였으며, 최저기온 특이값은 여름과 겨울 동안 감소하는 것으로 나타났다. 강수일수는 감소하고 일강수량이 80 mm 이상인 호우일수의 빈도는 증가하여 강수강도가 강화되는 것으로 나타났다.

• 한국세라믹학회지
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• 제31권2호
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• pp.171-176
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• 1994

The spin-casted PLZT(9/65/35) thin films through polymeric sol-gel process were prepared on Pt substrate. The crack-free, uniform and dense films were obtained by post-annealing at the temperature between 35$0^{\circ}C$ and $700^{\circ}C$. The composite structure mixed together with large grains called "rosette" and surrounding small grains were observed on the films annealed over $600^{\circ}C$. Pyrochlore phase was completely changed to perovskite phase above $600^{\circ}C$ with the increase of annealing temperature. Dielectric constant (k) was larger with the increase of film thickness and annealing temperature. from the measurements of dielectric constant as a function of measuring temperature, it was also observed that Curie temperature was shifted to higher temperature with the increase of film thickness and annealing temperature. The pyroelectric coefficient(P) of 10 times coated film annealed at $700^{\circ}C$ was 65 $\mu$C/$\textrm{cm}^2$.K.$.K.

• 한국주조공학회지
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• 제8권4호
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• pp.429-436
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• 1988

The influences of some casting conditions on bonding ratio and state at bonding zone of stainless steel-cast iron dual tube produced by centrifugal casting process were investigated to estimate fabrication technics. 1) Bonding ratio is increasing such as increasing of inner surface temperature of outer metal(stainless steel STS 304), if pouring temperature of inner metal (cast iron) is constant. 2) The more pouring temperature of inner metal (cast iron) increase, the more bonding ratio increase when inner surface temperature of outer metal (cast iron) is constant. 3) As the mold rotary speed is increase, the hatching area of bonding map (perfect bonding area) goes down to the low pouring temperature of inner metal. 4) In order to predict bonding state of two different metal, we are able to make and use the bonding map about casting conditions such as inner surface temperature of outer metal, pouring temperature of inner metal and mold rotary speed.

• Journal of Biosystems Engineering
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• 제13권3호
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• pp.59-70
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• 1988

A computer simulation model for rice circulating concurrent-flow dryer was developed and verified by conduction a series of pilot-scale experiment. The effects of design parameter and operating conditions on dryer performance were analyzed by using simulation. The results indicated that the developed model was found suitable for analyzing operating characteristics. The other results from simulation also showed that; 1) an increse in the initial moisture content resulted in an increase in the drying rate and a reduction in the grain temperature and total energy requirements. 2) an increase in the drying air temperature resulted in an increase in the drying rate and grain temperature. 3) an increase in air flow rate resulted in an radical increase in drying rate, fan power requirements and total energy requirements but an radical decrease in final head rice yield. 4) an increase in the bed depth resulted in an increase in fan power requirements and a lowering of the final head rice yield.

• 전기학회논문지
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• 제60권12호
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• pp.2311-2317
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• 2011

In this paper, we study the temperature change of a ${\mu}$-bolometer focal plane array with a capacitive transimpedance amplifier bias cancellation circuit. Thermal analysis is essential to understand the performance of a ${\mu}$-bolometer focal plane array, and to improve the temperature stability of a focal plane array characteristics. In this study, the thermal analyses of a ${\mu}$-bolometer and its two reference detectors are carried out as a function of time. The analyses are done with the $30{\mu}m$ pitch $320{\times}240$ focal plane array operating of 60 Hz frame rate and having a columnwise readout. From the results, the temperature increase of a ${\mu}$-bolometer in FPA by an incident IR is estimated as $0.689^{\circ}C$, while the temperature increase by a pulsed bias as $7.1^{\circ}C$, which is about 10 times larger than by IR. The temperature increase of a reference detector by a train of bias pulses may be increased much higher than that of an active ${\mu}$-bolometer. The suppression of temperature increase in a reference bolometer can be done by increasing the thermal conductivity of the reference bolometer, in which the selection of thermal conductivity also determines the range of CTIA output voltage.

• 한국의류학회지
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• 제17권4호
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• pp.511-517
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• 1993

Changes of the surface and interface tension with temperature for washing liquids and alkanes were measured by FACE surface tensiometer. Using the extended Fowkes' equation, the dispersion and polar force components of the surface tension were estimated. The results were as follows : 1. The surface tensions of washing liquids and alkanes decreased almost linearly with the increase of temperature. 2. The interface tensions of 0.25% DBS/alkane increased slowly with the increase of temperature. In the case of nonionic surfactant solutions, however, the interface tensions with alkanes varied with the number of hydrophilic ethylene oxide(EO) groups. 3. Of the surface tension of water at $20^{\circ}C$, the dispersion force component was 25.3 dyn/cm and the polar force component was 47.8 dyn/cm. As the temperature increased, both the polar and dispersion force components decreased in a similar fashion. 4. The dispersion force component of surface tension of 0.25% DBS solution was 30.0 dyn/cm, and the polar force component was 2.2 dyn/cm at $20^{\circ}C$. The two components decreased with the increase of temperature. 5. As the temperature increased, the dispersion force component of surface tension decreased and the polar force component increased significantly for 0.25% NPPG-7.5EO solution. In the case of 025% NPPG-10EO, both the dispersion and polar force components decreased slowly, but the polar force component is expected to increase from $60^{\circ}C$. However, the polar force component of surface tension decreased with the increase of temperature for 025% NPPG-15EO solution, and at the temperature higher than $60^{\circ}C$ the surface tension is expected to be composed of only dispersion force component.

• Restorative Dentistry and Endodontics
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• 제26권5호
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• pp.393-398
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• 2001

Polymerization of light-activated restorations results in temperature increase caused by both the exothermic reaction process and the energy absorbed during irradiation. Within composite resin, temperature increases up to 2$0^{\circ}C$ or more during polymerization. But, insulation of hard tissue of tooth lowers this temperature increase in pulp. However, many clinicians are concerned about intrapulpal temperature injury. The purpose of this study was to evaluate temperature changes in the pulp according to various restorative materials and bases during curing procedure. Caries and restoration-free mandibular molars extracted within three months were prepared Class I cavity of 3$\times$6mm with high speed handpiece fissure bur. 1mm depth of dentin was evaluated with micrometer in mesial and distal pulp horns. Pulp chambers were filled with 37.0$\pm$0.1$^{\circ}C$ water to CEJ. Chromium-alumina thermocouple was placed in pulp horn below restorative materials for evaluating of temperature changes. This thermocouple was connected to temperature-recording device(Multiplication analyzer MX, 6.000, JAPAN). Temperature changes was evaluated from initial 37.$0^{\circ}C$ after temperature changes to 37.$0^{\circ}C$. Tip of curing unit was placed in the center of prepared cavity separated 1mm from restorative materials. Curing time was 40s. The restorative materials were used with Z 100, Fuji II LC, Compoglass flow and bases were used with Vitrebond, Dycal. Resrorative materials were placed in 2mm. The depth of bases were formed in 1mm and in this upper portion, resin of 2mm depth was placed. This procedure was performed 10 times. The results were as follows. 1. All the groups showed that the temperature in pulp increased as curing time increased 2. The temperature increase of glass ionomer was significantly higher than that of Resin and Compomer during curing procedure (P<0.05). 3. The temperature increase in glass ionomer base was significantly higher than that of Calcium hydroxide base during Resin curing procedure (P<0.05).

• Journal of Photoscience
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• 제9권2호
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• pp.299-301
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• 2002

Recent denaturation experiments of bacteriorhodopsin (bR) in the dark and under illumination at high temperatures revealed that irreversible thermal bleaching occurs above ~ 70°C and the preceding reversible structural changes in the dark above 60°C are closely related to irreversible photobleaching observed in the same temperature range (Yokoyama et al. (2002). J Biochem. 131,785). In this study, structural properties of bacteriorhodopsin (bR) at high temperatures were extensively probed by hydroxylamine reactivity with the Schiff base in the dark and hydrogen-deuterium (H-D) exchange in the peptide groups. In the Arrhenius plot from kinetics measurements of the hydroxylamine reaction, a good linear relationship between the reaction time constant and the inverse of the absolute temperature was observed below 60°C, while significant increase started above 60°C, suggesting that remarkable increase in water accessibility of the Schiff base in the temperature region. FT-IR spectroscopic studies on the H-D exchange suggested increase in the deuterium exchanges rate of the peptide hydrogen in the same temperature region.

• International Journal of Automotive Technology
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• 제6권6호
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• pp.585-590
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• 2005

The effects of spark timing and exhaust valve timing change on exhaust gas temperature during cold start period of an SI engine are studied through engine bench tests. The exhaust gas temperature increases when the spark timing or valve timing are retarded individually, due to late combustion or slow flame speed. Therefore, exhaust gas temperature shows a large increase when the two timings are retarded simultaneously. However, it is considered that combustion stability during cold start deteriorated under these retarded conditions. To increase exhaust gas temperature for fast warmup of catalysts while maintaining combustion stability, an optimal condition for spark and valve timing retard should be applied for the cold start period.