• Journal of the Optical Society of Korea
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• 제12권3호
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• pp.152-156
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• 2008

This paper reports a fiber-optic temperature sensor using a single mode fused fiber coupler incorporating a thermo-optic external medium. The spectral transmission was altered by changing the refractive index of the external thermo-optic medium. A theoretical and experimental investigation was carried out with the aim of achieving high sensitivity. The measured sensitivity for the environmental temperature was as high as -1.5 $nm/^{\circ}C$.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권3호
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• pp.263-267
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• 2014

Super junction trench gate power MOSFETs have been receiving attention in terms of the trade-off between breakdown voltage and on-resistance. The vertical structure of super junction trench gate power MOSFETs allows the on-resistance to be reduced compared with conventional Trench Gate Power MOSFETs. The heat release of devices is also decreased with the reduction of on-resistance. In this paper, Lattice Temperature of two devices, Trench Gate Power MOSFET and Super junction trench gate power MOSFET, are compared in several temperature circumstance with the same Breakdown Voltage and Cell-pitch. The devices were designed by 100V Breakdown voltage and measured from 250K Lattice Temperature. We have tried to investigate how much temperature rise in the same condition. According as temperature gap between top of devices and bottom of devices, Super junction trench gate power MOSFET has a tendency to generate lower heat release than Trench Gate Power MOSFET. This means that Super junction trench gate power MOSFET is superior for wide-temperature range operation. When trench etching process is applied for making P-pillar region, trench angle factor is also important component. Depending on trench angle, characteristics of Super junction device are changed. In this paper, we focus temperature characteristic as changing trench angle factor. Consequently, Trench angle factor don't have a great effect on temperature change.

• 한국식품위생안전성학회지
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• 제38권5호
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• pp.332-337
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• 2023

본 연구는 계란의 품질 유지를 위한 온도변화의 영향을 평가하고 실제 유통 환경에서 난각에 Salmonella Enteritidis가 오염된 비세척란의 적절한 온도 관리 방법을 결정하고자 하였다. Salmonella Enteritidis가 접종된 비세척란은 총 7일간 25℃ 항온보관 및 5가지의 다른 온도변화조건에서 보관하였다. 온도변화조건은 계란을 초기 25℃에서 보관 중 온도를 10℃ 또는 35℃로 변화하였다. 보관 중 기실의 높이, 중량감소율, 비중 및 농후난백 비율을 1일 간격으로 평가하였다. 기실의 높이, 중량감소율, 비중은 25℃ 보관 3일 및 4일차에 10℃로 온도를 낮추었을 때 초기값이 유의적으로 보존되었다. 농후난백 비율은 초기 값과 비교하였을 때 보관 조건에 따른 유의한 차이를 나타내지 않았다. 이러한 결과는 25℃ 보관 3일 및 4일차에 10℃로 낮추는 것이 실제 유통 시 비세척란의 안전관리에 적합함을 시사하였다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제34회 추계학술대회 개최
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• pp.117-126
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• 2001

Tribological properties of high temperature fade were investigated by changing relative amounts of ingredients in the brake friction material. Based on a simple experimental formulation containing 10 ingredients, friction materials were tested using a pad-on-disk type friction tester. Twenty-five friction material specimens with different relative amounts of the ingredients were manufactured according to the constrained mixture design .The difference ($\Delta$${\mu}$=${\mu}$$\sub$max/. -${\mu}$$\sub$min/. ) of friction coefficients was measured to represent the high temperature fade. Results from elevated temperature tests showed that five ingredients including cashew, graphite, Sb$_2$S$_3$, ZrSiO$_4$, and Cu fibers played important roles on $\Delta$${\mu}$. In order to find relative importance on fade phenomena among these ingredients, ANOVA(analysis of variance) was performed in this investigation. Thirty-two friction material specimens by changing ${\pm}$50vol.％ of these five ingredients were tested to examine the relative importance. Results showed that cashew, graphite '||'&'||' Sb$_2$S$_3$, and cashew '||'&'||' graphite aggravated the fade behavior and Cu fibers improved on fade resistance.

• 설비공학논문집
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• 제21권5호
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• pp.291-296
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• 2009

Ice accumulating system patterned ice-an-coil is the way of refrigerating regenerative materials on the surface of copper-tube inserted into the inside of ice-storage. The study experimented to understand ice-an-coil type ice making characteristics according to changing shape of ice making tube. The experiment were carried out under various conditions, that used brine temperature($-l0^{\circ}C$, $-6^{\circ}C$) brine flow rate(l.0m/s, 1.8m/s) and inlet water temperature($6^{\circ}C$, $12^{\circ}C$) etc. Mass of ice per making area increased according to the decrease of the brine temperature and inlet water temperature, but that was increased according to the increase of the brine flow rate. And I set up two hypotheses and compared the capacity of ice-making of the two cases; each had the same thermal area and one had an round-shaped copper tube but the other had an oval-shaped copper tube.

• 한국농림기상학회지
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• 제19권4호
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• pp.252-269
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• 2017

본 시험은 품종별 개화가 가능한 기준온도와 저온($5.0^{\circ}C$) 누적시간 및 발아 후 변온에 따른 평균 개화소요일수를 구명하여 국내 주요 사과품종('후지', '쓰가루')들과 국내에서 육성한 품종('추광', '감홍', '홍안', '홍금', '홍로', '홍소', '화홍', '섬머드림', '선홍')들의 개화기를 예측하고자 군위지역에서 4년(2009-2012년)동안 조사하였다. 또한, 이들 자료를 이용하여 군위 지역 기온이 현재보다 $5.0^{\circ}C$ 상승되었을 때의 개화시기를 추정하였다. 저온($5.0^{\circ}C$) 누적시간(저온요구도)의 처리 범위는 0~1,671hr 정도였고, 저온 처리 후 개화를 위한 고온(고온요구도) 처리 범위는 $5.0{\sim}29.0^{\circ}C$ 정도였다. 발아 후 변온 처리구들은 항온구(대조구), $5.0{\sim}10.0^{\circ}C$ 상승구 및 하강구로 분류하였다. 결과를 살펴보면, 저온에서의 누적시간이 짧을수록 개화소요일수가 길어지는 경향이 있었으며, 0hr 처리구의 발아 후 개화까지의 소요된 일수는 1,335~1,503hr 처리구보다 2~4주 정도 길었다. 품종 별로는 모든 품종이 발아 후 기온이 $10.0^{\circ}C$ 미만일 때 개화를 하지 못하였고, 저온요구도가 낮은 품종일수록 개화에 필요한 고온요구도가 낮았다. 발아 후 기온을 $15.0^{\circ}C$로 조절된 처리구들의 개화소요일수는 $10.0^{\circ}C$ 처리구들보다 1~3주 정도 빨랐다. 발아 후 변온 처리에서는 발아 후 기온 상승 처리구들의 발아 후 개화까지 소요된 일수가 항온 처리구보다 짧았다. 이상의 결과를 종합해보면, 국내 주요 사과품종들의 개화 기준온도는 $10.0^{\circ}C$로 생각되었으며, 군위지역의 기온이 지금보다 $5.0^{\circ}C$ 정도 상승된다고 가정하면, 개화기는 1주 정도 지연될 것으로 예측되었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.945-949
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• 2001

This study is an experimental study on the characteristics of emission by changing catalytic converter position for cold-start. The measurements are done a changing of the distance between exhaust manifold and catalytic converter. It measured temperature of exhaust manifold, before and after catalytic converter at each position of experimental condition. and measured the characteristics of emission which is HC, CO, $CO_{2}$ and lambda at each position of experimental condition. The results show a few advantage about reduction of HC and CO as catalytic converter's temperature is raised quickly as closed exhaust manifold. but $CO_{2}$ has not the same trend of HC and CO. From measurement value of lambda, reduction effects of $NO_{x}$ are known a few advantage as increase of the distance between exhaust manifold and catalytic converter.

• 한국연소학회지
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• 제14권4호
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• pp.41-47
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• 2009

An experimental study was performed to confirm the effect of the changing combustor pressure(-30~30 kpa), combustion characteristics were investigated by measuring the local chemiluminescence intensity, the local temperature distribution and emission. In order to investigate combustion ones, the combustor pressure index($P^*$) was controlled in the range of 0.7~1.3 for each equivalence ratio in the present combustion system, where $P^*$ is defined as the ratio of absolute pressure to atmospheric one. The local mean temperature showed the uniform distributions for lower pressure index, which increased with increasing equivalence ratio. The mean $OH^*$ chemiluminescence intensity, showed high level for lower pressure index for ${\Phi}{\get}1.0$ conditions. EINOx decreased with decreasing pressure index for overall equivalence ratio conditions.

• 한국신뢰성학회지:신뢰성응용연구
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• 제6권3호
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• pp.205-212
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• 2006

The purpose of this article is about the accelerated product-reliability-test method of the changing colors of mobile products, which are majorly from the frequent touching of sweating fingers. Such problems of changing colors of mobile products have found mostly In metallic paint containing aluminum paste pigments. Also we found that the color of Al Paste is changed by human sweat. Therefore, the accelerated experimental method has been tested as follow: applying the various concentration of lactic acid, which is the changing color components from human sweat, and deeping the testing sample under temperature of $60^{\circ}C$ in dilutelactic acid with water. From the series of tests, the most optimum concentration of lacticacid has been obtained in 10wt% and the sample is observed to be almost same effect as natural changing of colors by human touching after the test. It has been also confirmed from the cross-sectional analysis. In detail, the testing sample has changed its color in 48hr by changing color effect of Alpaste with 10 wt% of lactic acid, and the digit of $\Delta$ E has measured 10.9 after the test.

• 동력기계공학회지
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• 제6권3호
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• pp.17-23
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• 2002

The purpose of this study is to investigate the combustion emission characteristics changing auxiliary air injection in combustion field of coaxial swirling diffusion combustor. For this purpose, mean temperature, CO, CO2, O2 and HC concentration were measured by changing excess air ratio and auxiliary air injection. As a result of this study, mean temperature, CO2 emission were increased and CO emission decreased by increasing auxiliary air. Therefore, this paper showed the auxiliary air injection effected strongly on flame structure and combustion emission characteristics.