• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.140-144
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• 2003

To investigate failure analysis of surface acoustic wave (SAW) filter for radio frequency, high temperature storage test was carried out. The failure criteria were insertion loss at passband and rejection level at stopband. As a result, the insertion loss at passband increase about 4 dB was due to damages of interdigital transducer (IDT). That is caused by poor adhesion between metal electrode(AI) and piezoelectric substrate and defects on a manufacturing process. This result indicates that good adhesion between electrode and ceramic substrate is important factor And also we investigated the demage factors of electrode. Screen possible of saw filter using high temperature storage test(HTOL) in the manufacturing phase be presented.

• 조명전기설비학회논문지
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• 제29권4호
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• pp.1-10
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• 2015

The light emitting diodes(LED) package of new structure is proposed to promote the reliability and lifespan by maximize heat dissipation occurred on the chip. We designed and fabricated the LED packages mixing the advantages of chip on board(COB) based on conventional metal printed circuit board(PCB) and the merits of Si sub-mount using base as a substrate. The proposed LED package samples were selected for the superior efficiency of the material through the sealant properties, chip characteristics, and phosphor properties evaluations. Reliability test was conducted the thermal shock test and flux rate according to the usage time at room temperature, high-temperature operation, high-temperature operation, high-temperature storage, low-temperature storage, high-temperature and high-humidity storage. Reliability test result, the average flux rate was maintained at 97.04% for each items. Thus, the Si sub-mount based LED package is expected to be applicable to high power down-light type LED light sources.

• Nuclear Engineering and Technology
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• 제55권10호
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• pp.3581-3590
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• 2023

High-temperature design evaluations were conducted on Type 316L stainless steel piping for a 700 ℃ large-capacity thermal energy storage verification test loop (TESET) under construction at KAERI. The hot leg piping with sodium coolant at 700 ℃ connects the main components of the loop heater, hot storage tank, and air-to-sodium heat exchanger. Currently, the design rules of ASME B31.1 and RCC-MRx provide design procedures for high-temperature piping in the creep range for Type 316L stainless steel. However, the design material properties around 700 ℃ are not available in those rules. Therefore, a number of material tests, including creep tests at various temperatures, were conducted to determine the insufficient material properties and relevant design coefficients so that high-temperature design on the 700 ℃ piping may be possible. It was shown that Type 316L stainless steel can be used in a 700 ℃ high-temperature piping system of Generation IV reactor systems or a renewable energy systems, such as thermal energy storage systems, for a limited operation time.

• 마이크로전자및패키징학회지
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• 제23권3호
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• pp.43-49
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• 2016

박형 package-on-package에 대해 T/H (temperature/humidity) 시험, TC (temperature cycling) 시험과 HTS(high temperature storage) 시험을 사용하여 신뢰성을 분석하였다. T/H 시험은 $85^{\circ}C/85%$의 조건으로 500시간, TC 시험은 $-40{\sim}100^{\circ}C$의 조건으로 1000회, HTS 시험은 $155^{\circ}C$의 조건으로 1,000시간 범위에서 평가하였다. 폴리이미드 써멀테이프를 사용하여 제작한 24개의 package-on-package (PoP) 시편에 대해 신뢰성 시험 전에 측정한 솔더접속 배선의 평균저항은 $0.56{\pm}0.05{\Omega}$이었으며, 24개 시편에서 모두 유사한 값이 측정되었다. 500시간까지의 T/H 시험, 1000회의 TC 시험 및 1,000시간까지의 HTS 시험후에도 솔더 접속부의 오픈 불량은 발생하지 않았다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1391-1393
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• 2008

In this paper, the long-term reliability for 1.25G transceiver in use of high speed optical access network is investigated. High temperature storage tests and accelerated life tests are used to long-term reliability. Accelerated aging test have been during 3,000 hour of the three accelerated aging conditions by caused high temperature stress. Mean life is assumed to follow the Arrhenius relationship and analysis from the failure data obtained in the accelerated aging conditions.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.676-683
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• 2000

For high quality storage of agricultural products, temperature, humidity and gas conditions in a storage house should be controlled properly. But most of the low temperature storage house is depending on temperature control. This study aimed to develop an automatic control system for low temperature storage house that can control storage conditions such as temperature, humidity and $CO_2$ gas concentration. The developed system alarms the user, by telephone or beeper, when abnormal condition has occurred. The farmer can also monitor the inside condition of warehouse in his residence, by Internet. From the results of the performance test, the temperature and relative humidity in the warehouse is controlled within the range of ${\pm}0.5^{circ}C$ and ${\pm}2%$, respectively.

• 한국식생활문화학회지
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• 제35권5호
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• pp.450-458
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• 2020

This study examined the optimal temperature and time conditions to maintain high quality Dongchimi during the fermentation and storage period. Dongchimi was fermented at low (5℃), medium (10 and 15℃), and high (20℃) temperatures until the acidity reached 0.2, 0.3, and 0.4%. respectively. From the consumer's preference test enrolling five consumers, Dongchimi fermented at 15℃ until an acidity of 0.3% (for approximately six days) was evaluated to be the optimal status because of its high score of overall acceptance, taste, and odor of consumers. To determine the optimal storage temperature of fermentation, Dongchimi was stored at three different temperatures (-1, 2, 5℃) for four weeks after fermenting at 15℃ for six days. During the storage period, most of the physicochemical properties (pH, acidity, reducing sugar content, and organic acid) and microbiological properties changed significantly in the 2 and 5℃ groups, resulting in a significant change in descriptive sensory analysis of Dongchimi. These results indicate that fermentation at 15℃ and storage at -1℃ for Dongchimi enables it to maintain the best quality for a long time.

• 대한화학회지
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• 제65권2호
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• pp.145-150
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• 2021

The present study describes a hands-on experiment to help students understand the concept of phase change or phase transition and its application in a phase change material (PCM). PCMs are substances that have the capability of storing and releasing large amounts of thermal energy. They act as energy storage materials that provide an effective way to save energy by reducing the electricity required for heating and cooling. Lauric acid (LA) was selected as an example of the PCM. Students investigated the temperature change of LA and the temperature (of air) inside the test tube. The differences in the temperatures of the systems helped students understand how PCMs work. A one-group pretest and posttest design was implemented with 34 grade-11 students in science and mathematics. Students' understanding was assessed using a multiple-choice test and a questionnaire. The findings revealed that the designed activity helped students understand the concept of phase change and its application to materials for thermal energy storage.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권3호
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• pp.238-244
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• 2016

Purpose: Domestic electric railway Regenerative Energy Storage System seriously affects the maintenance cost of the total operating expenses of nearly 60% of the total LCC (Life Cycle Cost) due to high dependence on foreign Leading company. Therefore by developing the system, it is important to lower the maintenance cost in the domestic supply. This study about the capacitor Reliability test and the purpose of this study is development electric railway Regenerative Energy Storage System. Methods: In case of, having a close relation between the temperature and the reaction rate, Accelerated Model was known that according to Arrhenius' law of chemical activity. If you apply this formula in using allowable temperature range of the capacitor can induce the Arrhenius empirical formula used in much Manufacture Fields. We evaluate the capacitors Leading company through the Arrhenius model. in order to providing a base for the localization of Ultra Capacitor. Conclusion: In this paper, we conducted a reliability test. And it was performed by the accelerated life test and Cycle Test with temperature and C-rate. and then MTBF and B10 life are estimated by analyzing the accelerated life test result. This is thought to need detailed study applying complex stress than about whether it matches the actual behavior in electric railway.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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• pp.259-261
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• 2012

본 연구에서는 3점 굽힘시험 및 DMA 시험을 통해 온도환경이 에폭시 수지의 굽힘탄성계수에 미치는 영향을 조사하였다. 굽힘 시험의 온도 조건은 $30^{\circ}C$, $100^{\circ}C$, $140^{\circ}C$의 세 가지 조건을 적용하였으며 시편은 종횡비 16, 32, 40배의 세 가지 종류가 고려되었다. 연구결과에 따르면 DMA를 통한 저장탄성계수와 굽힘시험을 통해 얻은 강성은 주어진 온도조건에서 서로 유사한 경향을 보였다. 또한 종횡비가 증가함에 따라 굽힘탄성계수도 증가 하였으며, 고온환경에서는 32배 이상의 종횡비가 적합하다고 판단된다.