• 마이크로전자및패키징학회지
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• 제12권2호
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• pp.135-140
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• 2005

Although it was recently observed that severe fatigue damage was formed in Al or Cu interconnects due to the cyclic temperatures generated by Joule heating of the metal lines by the passage of alternating currents (AC), AC loading frequency effect on the damage evolution characteristics are not known so far. This work focused on the effect of AC loading frequency (100 Hz vs. 10 kHz) on the thermo-mechanical fatigue characteristics by using polycrystalline sputtered Cu lines with temperature cycles with amplitudes from 100 to $300^{\circ}C$. It was consistently observed that higher loading frequency accelerated damaged grain growth and led to earlier failure irrespective of Cu grain sizes. The frequency effect is believed to result from differences in the concentration of defects created by the deformation-induced motion of dislocations to the grain boundaries.

• 한국자원식물학회지
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• 제13권3호
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• pp.202-207
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• 2000

자생식물 16종의 종자형질 특성 및 저온습윤 및 변온 처리에 의한 발아양상을 조사하기 위하여 본실험은 수행되었다. 종에 따라 종자의 길이, 넓이, 폭은 각각 1.1∼8.9, 0.7∼7.5, 0.4∼l.7mm의 범위였으며 천립중은 0.1∼8.8g의 범위였다. 무처리에서 발아율이 가장 높은 종에 있어 냉이와 익모초는 암조건에서 각각 16, 36%이었으며 장구채와 각시취는 명조건에서 각각 69, 81%이었다. 참취, 고려엉겅퀴, 곰취, 질경이, 청옥취는 저온습윤처리 명조건에서 각각 84, 29, 57, 78, 95%로 물엉겅퀴는 암조건에서 30%로 발아율이 가장 높았다. 변온처리에서 발아율이 높은 종에 있어 두릅나무와 벌개미취는 명조건에서 각각 2,57%로, 수리취는 암조건에서 52%로 가장 높았다.

• 한국응용곤충학회지
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• 제26권1호
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• pp.13-23
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• 1987

온도조건이 벼멸구(Nilaparvate lugens Stal)의 발육과 산란에 미치는 영향을 정밀하게 조사하여 벼 포장에서의 온도변화에 따른 벼멸구의 발육경과를 예측함으로서 방제적기를 포착하는데 필요한 기초자료를 얻고자 정온과 변온의 식물 생장조정항온기 내에서 벼멸구의 발육속도 및 산란력을 측정하는 실험을 수행한 바 그 결과를 요약하면 다음과 같다. 1. 정온조건에서의 발육 및 산란 벼멸구 난의 부화율은 $25^{\circ}C$에서 가장 높았으며 그 이하나 이상의 온도로 변함에 따라 낮아지는 경향이었다. 난기간은 $27.5^{\circ}C$에서 가장 짧았으며 온도가 낮아짐에 따라 난기간이 길어지는 경향이었고 $30^{\circ}C$ 이상의 고온에서도 난의 발육이 지연되었다. 우화율은 $27.5^{\circ}C$에서 가장 높았고 온도가 낮아짐에 따라 낮아져 $32.5^{\circ}C$와 $35^{\circ}C$에서는 전혀 우화하지 못하였다. 약충기간은 $27.5^{\circ}C$와 $30^{\circ}C$에서 가장 짧았으며 온도가 낮아짐에 따라 길어지는 경향이었다. 우화성충의 수명은 온도가 낮아짐에 따라 길어지는 경향이었고 수컷은 $27.5^{\circ}C$에서 수명이 가장 짧았다. 산란전기는 $32.5^{\circ}C$에서 가장 짧았으며 온도가 낮아짐에 따라 길어져 $17.5^{\circ}C$에서는 $32.5^{\circ}C$에서보다 약 6.5배에 달했다. 산란수는 $25^{\circ}C$에서 가장 많았으며 그 이하나 이상의 온도로 변함에 따라 적어지는 경향이었다. 2. 변온조건과 정온조건에서의 발육 및 산란 같은 유효적산온도에서, 난의 부화율은 정온 조건에서보다 변온조건에서 약 10% 정도 높았으나 난기간은 큰 차이가 없었다. 우화율은 $22^{\circ}C$ 동일 유효적산온도 조건의 경우 변온에서 약 8% 정도 높았으나 $28^{\circ}C$ 동일 유효적산온도의 경우 반대로 정온조건에서 약 8% 정도 높았다. 약충기간은 정온조건에서보다 변온조건에서 약 $4{\sim}6$일 정도 길었다. 같은 유효적산온도에서, 성충의 수명과 산란수는 성충기의 온도가 정온인 것보다 변온인 것에서 길었으며 산란수도 많았다. 한편, 난기에서부터 약충기까지 노출시켰던 온도를 고려해 보면 약충기까지 $28^{\circ}C$ 정온에서 노출시켰던 구에서 각 온도 공히 성충의 수명이 길어져 성충의 수명은 약충기의 온도에 영향을 받았다. 산란전기에는 약충기와 성충기의 온도가 함께 영향을 주었으며 산란수에는 성충기의 온도가 큰 영향을 주었다. 3. 각 발육단계별 발육임계온도 및 유효적산 온도 본 실험결과 계산된 발육임계온도는 난기에서 $14.12^{\circ}C$, 약충기에서 $14.76^{\circ}C$, 성충기에서 $9.12^{\circ}C$, 산란전기에서 $15.95^{\circ}C$로 나타났다. 각 발육단계별 유효적산온도는 난기에서 141.25 온일도(Degree-Day), 약충기에서 167.83 온일도, 성충기에서 349.64 온일도, 그리고 산란전기에서 58.60 온일도 이었다.

• The Korean Journal of Ecology
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• 제12권4호
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• pp.219-236
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• 1989

The effect of salinity on the seed germination and seedling growth of Pinus densiflora for. erecta Uyeki were studied under the controlled conditions in the growth chamber. The seeds were sorted into three classes in weight such as large ($15.49\pm$1.63mg), medium($10.61\pm$1.38mg), and small ($6.57\pm$1.33mg) to determine the role of seed weight in germination and seedling growth of the pine. Polymorphic seeds of the pine were germinated an salinity range of 0 to 1.5% NaCl under various temperature ($10^{\circ}$ $-25^{\circ}$ with $5^{\circ}$C interval of constant temperature, and $10^{\circ}$ $-20^{\circ}$C, $15^{\circ}$ $-25^{\circ}$C of alternating temperature) in order to determine their germinability and seeding growth. In control plot, there was little difference of germination percentage among the seed weight classes, but in saline plot, the larger seeds generally had a higher percentage and rate of germination. There occurred synergistic interaction between salinity and temperature in the germination and the increase of temperature enhanced germination of seeds at the same salinity level. Alternating temperature regimes of $15^{\circ}$-$25^{\circ}$C yielded maximum germination and no germination was occurred at $10^{\circ}C$. The germination at alternating temperature showed higher germination percentage than at constant temperature. The percentage and of germination decreased drastically with increased salinity level to 1.00%; no germination was occurred at 1.50% salinity level. The growth fo sddelings from larger seeds was better than that of smaller seeds at the same salinity and temperature. The hypocotyl and radicle were more sensitive than cotyledon to the increased salinity stress.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.44-44
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• 2019

Spring sowing of ginseng seeds often results in failure of seedling establishment. Storage condition during winter, sowing time, and seed treatment might effect on germination. Here we tested effects of temperature regimes of seed storage on spring sowing. Dehisced wet or dry ginseng seeds were stored at $2^{\circ}C$, $-2^{\circ}C$, $-3.5^{\circ}C$, or alternating temperature: at $2^{\circ}C$ until December, $-3.5^{\circ}C$ in January, and $2^{\circ}C$ in February, and sowed in March. In overall, emergence rate was dependent on storage temperature, and $-3.5^{\circ}C$ resulted poorest emergence than other conditions. Storage of wet seeds in alternating temperature resulted highest emergence rate. Seed dry also affected on emergence rate, while it was dependent on the storage temperature. In terms of growth, storage at $2^{\circ}C$ as wet seed resulted highest growth, and dried seeds resulted poorer growth than wet seeds. As a modification of alternating temperature, seeds were stored at $2^{\circ}C$ at first, then transferred to $-3.5^{\circ}C$ at Nov 30, Dec 20, and Jan 10, each. When transfer date was delayed, emergence rate was increased. We suggest that seed storage temperature for ginseng should not be decreased below $-2^{\circ}C$, and alternative temperature regime for successful spring sowing could be useful.

• Journal of Magnetics
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• 제17권1호
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• pp.42-45
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• 2012

We have developed an alternating magnetic field stimulation system consisting of a switched-mode power supply and a digital control circuit which modulates a duty ratio to maintain a magnetic field intensity of a few mT even while the frequency increases up to 4 kHz with a controllable coil temperature below $30^{\circ}C$ in air. This duty ratio modulation and water circulation are advantageous for cell culture under ac-magnetic field stimulation by preventing the incubator from exceeding a cell-viable temperature of $37^{\circ}C$. Although the temperature of the coil when subjected to a sinusoidal voltage rapidly increased, that of our system modulated by the duty factor did not change. This is a potentially valuable method to investigate the effects of intermediate frequency magnetic field stimulation on biological entities such as cells, tissues and organs.

• 한국전기전자재료학회논문지
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• 제16권11호
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• pp.1041-1046
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• 2003

In order to improve the surface uniformity and the conduction properties of the fabricated YBCO thick films, a system that applies alternating field vertically to the EPD field has been developed for the first time and applied to the electrophoretic deposition process. The applied alternating electric field, so called Shaky Alternating Assisted Field, caused a force to be exerted on each YBCO particle and resulted in a shaking of the particle in the direction of applied electric field, accomplishing a uniform particle orientation. The usual commercial electrical power was used for the vertically applied alternating voltage and the induced electric field was 25-120 V/cm at 60Hz. The thick film fabricated by the method developed in this paper showed better surface uniformity without crack and porosity and improved film characteristics such as critical temperature (Tc,zero = 90 K) and critical current density (2354 A/$\textrm{cm}^2$), Therefore, it is expected that the shaky-aligned electrophoretic deposition method can be used to fabricate superconductor films through a simpler process and at less expense.

• 한국식품영양과학회지
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• 제33권10호
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• pp.1709-1714
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• 2004

숙성온도 조건(5$^{\circ}C$, 2$0^{\circ}C$ 및 변온조건)을 달리한 명태식해에서 숙성에 지배적으로 관여하는 미생물상의 변화 및 효소학적 특성을 구명하였다. 2$0^{\circ}C$조건의 숙성초기에는 단백질분해균이나 Lactobacillus속 및 Pediococcus속이 총균수의 대부분을 차지하였으며, 숙성 10일 이후에는 단백질분해 3, Leuconostoc속, Streptococcus속 및 Pediococcus속의 감소가 총균수의 감소에 기여하였고 숙성 10일 이후의 총균수는 Lactobacillus속, Pediococcus속 및 효모가 대부분이었다. 변온조건의 경우 숙성 10일 이후에도 총균수가 일정수준을 유지하였는데, 이는 Lactobacillus속, Pediococcus속 및 Streptococcus속이 변온 이후에도 균수가 일정하게 유지되었기 때문이다. 따라서 2$0^{\circ}C$와 변온에서 숙성 10일 이후의 균증식 양상은2$0^{\circ}C$의 경우효모의 증식이 우세한 반면에, 변온에서는 Streptococcus속의 증식이 우세하였다. 반면 5$^{\circ}C$의 경우 Lactobacillus속이 숙성초기에 대부분을 차지하였고 특히 Leuconostoc속이 다른 조건의 비해 오래 지속되었다. 산성단백질분해효소 및 지방분해효소 활성은 온도에 민감하여 2$0^{\circ}C$일 때가 5$^{\circ}C$보다 활성이 높은 반면 중성 단백질분해효소와 지방분해효소는 온도에 따른 활성의 차이가 나타나지 않았다. 그리고 변온조건에서는 단백질분해효소의 경우 실활 되었고, 지방분해효소는 온도변화에 적응력이 존재하여 활성 이 유지되었다.

• Journal of the Korean Wood Science and Technology
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• 제41권5호
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• pp.456-465
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• 2013

Log cross sections of yellow poplar were dried in a radio frequency vacuum (RFV) dryer under alternating vacuum and release (AVR) process. The average moisture content (MC), temperature and vapor pressure at the volumetric center were monitored as functions of time. Three different log thicknesses (33, 60 and 75mm) were tested. The results show that the AVR process caused an increase in the drying rate when the moisture content was above fiber saturation point (FSP, about 30% MC) but that it had an inverse effect on the drying rate when the MC was below FSP. The effect of the AVR process on the drying rate decreased, and the severity of heart checks increased, with the increase in the thickness of the specimens.

• 한국수산과학회지
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• 제55권2호
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• pp.121-128
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• 2022

The aims of this study were to optimize the processing procedure of high-quality semi-alternating temperature dried Israeli carp Cyprinus carpio (SAD-IC) and to investigate the sensory properties of the product. Based on the differences in moisture content of the dorsal and ventral muscles, high quality SAD-IC was prepared by alternating the drying temperature between 4 h at 35℃, and 2 h at 5℃, three times before final drying for 2 h at 35℃. The surface in SAD-IC produced under the optimal alternating-temperature drying process had a markedly superior browning index value and softer texture compared to products produced using constant-temperature drying. SAD-IC produced from dorsal and ventral muscle had significantly superior taste values than the raw material. These results suggest that SAD-IC has the potential to be industrialized.