• The Korean Journal of Food And Nutrition
• /
• v.17 no.4
• /
• pp.405-411
• /
• 2004

The sensory properties in Alaska pollack sikhae were compared in 3 different temperature conditions, 5$^{\circ}C$, 20$^{\circ}C$ and alternating temperature(stored at 5$^{\circ}C$ after 10 days of fermentation at 20$^{\circ}C$), respectively, during fermentation. The change of instrumental texture including hardness, cohesiveness, adhesiveness and chewiness increased and/or decreased without significant difference in the sikhae fermented at 5$^{\circ}C$ during fermentation. Three profiles, hardness, chewiness and cohesiveness in the sikhae fermented at 20$^{\circ}C$ increased up to 12 day and then decreased, whereas those in alternating temperature decreased significantly. From the acceptance test during fermentation, sikhae products fermented for 14 days at 5$^{\circ}C$, 9 days at 20$^{\circ}C$ and 13 days at alternating temperature were superior in sensory properties. The score more over 5 point in overall acceptance was maintained until 14 days in 5$^{\circ}C$, 9 days in 20$^{\circ}C$ and 13 days in alternating temperature, respectively, and particularly, alternating temperature condition was superior to the different temperature conditions. The sensory texture and overall acceptance had the high positive correlation with chewiness and taste, respectively. From the result of quantitative descriptive analysis, the intensities of acidic odor and taste in alternating temperature maintained and/or increased during 27 days of fermentation, whereas those in sikhae fermented at 5$^{\circ}C$ decreased. These results demonstrated that cold chain system such as alternating temperature was needed for shelf-life extension and producing of marketable Allaska pollack sikhae.

• Journal of the Korean Society of Combustion
• /
• v.4 no.1
• /
• pp.95-103
• /
• 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.

• Korean Journal of Medicinal Crop Science
• /
• v.24 no.4
• /
• pp.284-293
• /
• 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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.11a
• /
• pp.459-462
• /
• 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.

• Journal of the Microelectronics and Packaging Society
• /
• v.12 no.1 s.34
• /
• pp.27-33
• /
• 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.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.20 no.2
• /
• pp.39-47
• /
• 2018

This study was carried out to investigate the applicability of alternating temperature control during night time in a nursery seedling production. Three groups of samples were exposed to three different environmental conditions for 6 days from 18:00 to 09:00; one was constantly 15 ℃, another was alternating between 15 ℃ for 2 hours and 11 ℃ for 2 hours, and the other was alternating between 15 ℃ for 2 hours and 11 ℃ for 4 hours. Leaf temperature and stem temperature was measured in real time. The influence of cold stress was analyzed by flavonoid content and growth of tomato seedling. The temperature of leaves and stem became equal to the ambient temperature over time, furthermore, there was no significant difference among the treatments. In conclusion, it is considered that heating costs can be saved considerably, as the alternating temperature has fewer effects on cold stress reaction by tomato seedling growth.

• Progress in Superconductivity and Cryogenics
• /
• v.15 no.1
• /
• pp.51-54
• /
• 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.

• Journal of the Semiconductor & Display Technology
• /
• v.3 no.1
• /
• pp.35-39
• /
• 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.

• Journal of the Korean Vacuum Society
• /
• v.14 no.1
• /
• pp.24-28
• /
• 2005

A typical method for obtaining poly-Si films is the solid phase crystallization(SPC) of amorphous Si. Advantages of SPC are uniformity, process quality and low cost of production. However, high process temperature and long process time prevent the employment of SPC process on thermally susceptible glass substrate. In this parer, we propose a new method that applies an alternating magnetic field during crystallization annealing in an alternating magnetic field crystallization(AMFC) system for lowering process temperature and shorter process time of SPC. When we crystallized, in the case of SPC, annealing time is 24 hours at 570℃. But in the case of AMFC, annealing time is only 20 minutes at the same temperature.

• Progress in Superconductivity
• /
• v.6 no.2
• /
• pp.138-141
• /
• 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.