• 한국식품영양학회지
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• 제17권4호
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• pp.405-411
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• 2004

명태식해를 제조하여 온도조건(5$^{\circ}C$, 2$0^{\circ}C$, 변온조건)에 따른 관능적 특성을 비교 분석하였다. 기계적 조직감의 변화는 5$^{\circ}C$의 경우 경도, 부착성, 응집성 및 씹힘성에서는 증감은 있었으나 유의적 차이가 없었다. 2$0^{\circ}C$에서는 경도, 응집성 및 씹힘성이 전반적으로 숙성 12일까지 증가하다가 그 후로는 감소하였으나, 변온에서는 유의적으로 감소하였고, 감소폭도 적었다. 숙성 온도별에 따른 기호도의 변화를 살펴보면 5$^{\circ}C$, 2$0^{\circ}C$ 및 변온은 각각 14일, 9일 및 13일이 관능적으로 가장 좋았으며, 종합적 기호도가 5점 이상점을 유지하는 시점은 각각 14일, 12일 및 21일로 변온의 경우가 가장 양호하였다. 그리고 관능적 조직감은 씹힘성과, 전반적 기호도는 맛과 높은 양의 상관관계를 가졌다. 정량적 묘사분석(QDA) 결과 일정 숙성기간 후에 변온조건으로 저장함으로써 신맛과 신냄새는 일정 강도를 유지한 반면에 5$^{\circ}C$에서는 오히려 감소하는 경향을 보였다. 결론적으로 변온조건이 다른 온도조건에 비해 관능적 품질(조직감 및 기호도)의 유지가 양호하였으며, 종합적 기호도(5점 이상)가 저장 21일까지 유지되어 5$^{\circ}C$의 14일, 2$0^{\circ}C$의 12일에 비해 연장효과가 있었다. 따라서 산업화를 위한 명태식해 제조에서는 저온저장의 고려는 필수적이라고 생각되었다.

• 한국연소학회지
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• 제4권1호
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• pp.95-103
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• 1999

Experimental study on combustion characteristics of a regenerative combustor has performed. High-temperature air combustion in the regenerative combustor is obtained through heat recovery from exhaust gas flow by porous ceramic materials and through alternation of air flow direction through the combustor. Temperature field, CO and NOx emission with respect to the frequency of alternation are measured. It is found that at initial stage of the alternation, temperature of inlet section of main combustion chamber is increased sharply since both high temperature air preheated by the ceramics and prompt fuel injection results in rapid combustion. Following this initial stage, combustion temperature is reduced as the preheated air temperature is reduced. However peak temperature in the chamber and exhaust gas temperature are decreased as the alternation period is reduced, increased temperature of ceramic is observed. CO and NOx emission with respect to the alternation period is also examined. It is found that there exists a range of optimum alternating period for CO and NOx emission characteristics.

• 한국약용작물학회지
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• 제24권4호
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• pp.284-293
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• 2016

Background: Developing new ginseng cultivars is a significant time-consuming process owing to the three years of growth required for ginseng to flower. To shorten the ginseng breeding process, it is necessary to establish rapid progression through each generation. In this study, we examined it was possible to rapidly break ginseng seed dormancy using gibberellic acid ($GA_3$) treatment and alternating temperature. Methods and Results: Seeds were obtained from local variety. Seeds were treated with either $GA_3$ at a concentration of $100mg/{\ell} $, constant temperature ($-2^{\circ}C$ and $2^{\circ}C$), alternating temperature ($2^{\circ}C$ followed by $-2^{\circ}C$, followed by $2^{\circ}C$) or a combination $GA_3$ and temperature treatment. Following experimental treatment, seeds were sown into trays and placed in a greenhouse. Low germination rates were observed in seeds that did not receive $GA_3$ treatment, which were similar following $2^{\circ}C$ and $-2^{\circ}C$ constant temperature treatment. Germination rates increased in proportion to $GA_3$ and more so when combined with alternating temperature treatment. In additon, stem and leaf lengths of the resulting ginseng plants were increased following $GA_3$ treatment, although no synergistic effect was observed with alternating temperature treatment. Conclusions: These results suggest that a combination $GA_3$ and alternating temperature treatment enhances ginseng seed germination, which can contribute to shortening the time required to progress through a single ginseng generation for breeding.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.459-462
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• 2000

A new method for the fabrication of poly-Si films is reported using by alternating magnetic flux crystallization (AMFC) of LPCVD a-Si films. In this work we have studied the crystallization of LPCVD a-Si films by alternating magnetic flux. A-Si films were 1200$\AA$-thick deposited at 48$0^{\circ}C$ at a total pressure of 0.25Torr using Si$_2$H$_{6}$/H$_2$. After this step, these a-Si films were thermally annealed by Alternating Magnetic Flux at 43$0^{\circ}C$ for 1hours. The annealed films were characterized using X-ray diffraction (XRD), Raman Spectra, Atomic Force Microscopy(AFM). Both alternating magnetic flux crystallization and solid phase crystallization were investigated to compare enhanced crystallization a-Si. We have found that the low temperature crystallization method at 43$0^{\circ}C$ by alternating magnetic flux.x.

• 마이크로전자및패키징학회지
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• 제12권1호
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• pp.27-33
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• 2005

The effect of microstructure on alternating current-induced damage in 200 and 300 nm thick polycrystalline sputtered Cu lines on Si substrates has been investigated. Alternating currents were used to generate temperature cycles (with ranges from 100 to $300^{\circ}C$) and thermal strains (with ranges from 0.14 to $0.42\%$) in the Cu lines at a frequency of 10 kHz. Fatigue loading caused the development of severe surface roughness that was localized within individual grains which depends severely on grain orientations.

• 현장농수산연구지
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• 제20권2호
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• pp.39-47
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• 2018

본 연구에서는 토마토 모종을 대상으로 육묘기간 중 야간에 단시간 동안의 저온 노출에 따른 토마토의 잎과 줄기의 온도변화를 실시간으로 측정하였으며, 저온 스트레스가 항산화물질 생성에 미치는 영향과 생육을 분석하여 육묘 시 단시간의 변온관리 가능 여부를 구명하였다. 야간 변온실험은 첫날 18시부터 6일 후 9시까지 15℃ 항온, 15℃ 2시간과 11℃ 2시간 변온, 15℃ 2시간과 11℃ 4시간 변온처리를 하여 잎과 줄기의 온도, 생육정도 및 플라보노이드 함량을 측정하여 저온 스트레스 영향을 분석하였다. 실험결과, 토마토 모종은 기온에 따라 엽과 줄기 온도가 비슷해지는 경향을 보였으며, 15℃와 11℃ 각각 2시간씩 반복 변온처리한 토마토 묘와 15℃ 항온처리한 토마토 묘의 생육과 플라보노이드 함량 간의 차이가 작은 것으로 나타났다. 본 실험을 통해 육묘시 야간온도를 15℃ 2시간과 11℃ 2시간으로 반복하도록 관리하여도 저온 스트레스 영향이 적은 것으로 나타났다. 이러한 결과로 미루어 볼 때 육묘시 야간의 변온처리로 난방비 절감이 가능할 것으로 사료된다.

• 한국초전도ㆍ저온공학회논문지
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• 제15권1호
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• pp.51-54
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• 2013

This paper deals with harmonic components of the voltage on high temperature superconducting wire carrying an alternating current. HTS wire is used to manufacture superconducting power applications carrying an alternating current. Typically, international standard, IEC 61788-3 is used for critical current measurement. Thus, it is not ideal that critical current criteria in dc are adapted to superconducting power devices to decide the operating current of the devices. In this paper, we confirmed odd harmonic voltage on HTS wires carrying an AC. The ratio between harmonic components and fundamental component can be significant clues to decide the critical current criteria for HTS wire and its power applications in AC circumstance.

• 반도체디스플레이기술학회지
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• 제3권1호
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• pp.35-39
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• 2004

Statistical design of experiments was successfully employed to investigate the effect of alternating magnetic field on activation of polycrystalline Si (p-Si) doped as n-type using $\textrm{PH}_3$, by full factorial design of three factors with two levels. In this design, the input variables are graphite size, alternating current, and activation time. The output parameter, sheet resistance, is analyzed in terms of the primary effects and multi-factor interactions. Notably, the three-factor interaction is calculated to be a dominant interaction. The interaction between graphite size and activation time and the main effect of current are important effects compared to the other variables and relevant interactions. Alternating magnetic flux activation is proved a significantly beneficial processing technique.

• 한국진공학회지
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• 제14권1호
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• pp.24-28
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• 2005

a-Si을 poly-Si으로 결정화하는 전형적인 방법으로는 고상결정화(Solid Phase Crystallization, SPC)가 있다［1-3］. 고상결정화는 균일한 공정특성과 생산비가 저렴하다는 장점이 있으나, 고상결정화 공정에서 높은 공정온도와 긴 공정 시간은 유리 기판의 손상으로 인해 적용되기 어렵다. 본 논문에서는 고상결정화의 저온공정과 짧은 공정시간을 위해 교번자장결정화(Alternating Magnetic Field Crystallization, AMFC) 시스템 내에서 결정화하는 동안 교번자장(Alternating Magnetic Field)을 적용하는 새로운 방법을 소개한다. 고상결정화의 경우, 열처리 시간은 570℃에서 24시간이 소요되었으나, 교번자장결정화의 경우, 같은 온도에서 20분이 소요되었다.

• Progress in Superconductivity
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• 제6권2호
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• pp.138-141
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• 2005

Bi-2223/Ag tapes need to be safe, even it is under the over-critical current state for the protection of a superconducting power machine. However, it is not easy to identify the condition for the safe operation because of their broad S/N transition region. In this paper, for the study of the operation condition of Bi-2223/ Ag tapes, we investigated the V-I curves and the temperature variation of Bi-2223/ Ag tapes experimentally, applying alternating over-currents, and analyzed the relationship between resistance and temperature increase. For the experiments, a Bi-2223/Ag tape of 57 A $I_c$ was prepared, and the over-critical current characteristics under adiabatic state from $LN_2$ was measured. From the experiments, we confirmed that the Joule heating predicted by V-I curve corresponded with the increase of the measured temperature exactly. Using the results, a safe operation condition of Bi-2223 tape was discussed.