• Journal of Plant Biotechnology
• /
• v.34 no.4
• /
• pp.363-373
• /
• 2007

To establish an efficient and reliable microspore culture system for pepper (Capsicum annuum L.), the effect of light intensity used for donor plant's growth, microspore isolation methods, the composition of culture medium, and culture period in light on the production of embryos were investigated. The viability of microspores taken from the plants grown under the light intensity of 10,000 lux was almost same as that from the lower (5,500 lux) light intensity, and the embryo induction and development were a bit higher when donor plants were grown under the lower light intensity. This result implies that lower light intensity does not interfere with the embryo induction and development. However, it was very difficult to prepare microspores for culture since only a small number of flower buds could be harvested from plants grown under the light intensity of 5,500 lux. Microspore isolation methods greatly affected microspores viability; that is, when microspores were isolated by blending rather than maceration, the greater number of viable microspores were easily generated (about 13 times). Among media used for microspores culture in this study, MN medium was most efficient for embryo induction and development. Total number of embryos and the number of cotyledonary embryos were highest when microspores were cultured in dark for 4 weeks, and then in light for one week. These results will be provide valuable information to set up efficient microspore culture system of hot pepper with a high frequency of embryo production, which are applicable to gene transformation and mutagenesis.

• Journal of Photoscience
• /
• v.9 no.2
• /
• pp.359-361
• /
• 2002

A green mutant of Rhodobacter sphaeroides 60I was acquired by chemical induction. The blue-shifted of the carotenoid absorption was found in the Light-harvesting complex II (LH2) of the mutant. With the excitation at different wavelength, we observed that the evolution of excited-state dynamics in LH2 of Rhodobacter sphaeroides 60I. The dynamical traces demonstrate a dominant absorption followed concomitantly by an ultrafast transmission increase and decay with 818nm excitation.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.137-140
• /
• 2005

Organic light emitting transistors (OLET) which are vertically combined with the organic static induction transistor (OSIT) and organic light emitting diode (OLED) are fabricated and the device characteristics are investigated. High luminance modulations by relatively low gate voltages are obtained. In order to realize the flexible electronic circuits and displays, we have fabricated OSIT on plastic substrates. The OSIT fabricated on plastic substrate show almost same characteristics comparing with those of nonflexible OSIT on glass substrate. The OLET described here is a suitable element for flexible sheet displays.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.05a
• /
• pp.454-458
• /
• 2005

Light railway system has many characteristics of better accessibility, frequency service, low construction cost, reduced air pollution and medium capacity public transport etc. Light railway system as a urban transportation system has been glowing worldwide since the late 20th century. More than 300 cities around the world have light railway systems. Many medium-size cities in domestic site is planning the construction of light railway. This paper reviews the domestic and foreign light railway system.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.35 no.9
• /
• pp.403-408
• /
• 1986

In this paper, the method to improve the efficiency of an induction motor at light load is discussed. Efficiency of induction motor can be very substantially improved by keeping the slip frequency as constant. Therefore, to simplify the control loop, algorithm which maintain constant slip frequency and control the input voltage is adopted. Simplified high efficiency drive of induction motor using PLL technique is suggested. In order to verify the validity of this system, the test results are compared with those obtained by optimal slip drive system and then we found closer to the optimal efficiency. For example its efficiency is improved from 18[%] to 42[%] at a few fraction of the full load (20[%]).

• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.316-320
• /
• 2008

A light rail transit, using a linear induction motor, is generally composed with reaction plates along railroad track and the three phase primary on the vehicle. This linear induction motor is driven to keep clearance between the primary and the secondary of the ground for preventing any contact. Therefore efficiency and power factor is very low. In addition, the reaction plate installed on the ground throughout entire railway is impossible to keep uniform gap and it may cause system deterioration. In this paper, A rotary-type small-scale model of a linear induction motor for various characteristic analysis is designed. Thrust force, normal force and input current of the model by air-gap variation have been analyzed by using a Finite Element Method (FEM). The effects of air-gap variation on system performance have been considered by analysis results.

• Journal of Photoscience
• /
• v.9 no.2
• /
• pp.338-340
• /
• 2002

In broom sorghum, Sorghum bicolor Moench, UV causes anthocyanin synthesis having action peaks in UVA and UVB regions. We previously reported that UV induces anthocyanin synthesis through UVB photoreceptor and phytochrome activated by UV. Furthermore, UVA and UVB amplify phytochrome-induced anthocyanin synthesis (PIAS). Our action- spectroscopic research indicated that a UV -receptor for amplification of PIAS is likely to be the same or same type of UVB photoreceptor for induction of anthocyanin synthesis. UVA-amplification of PIAS can be explained by the action of a cryptic red light signal (CRS), an amplification factor for PIAS produced by a distinct phytochrome-species activated by UVA. We suggest that UVA photoreceptors are not involved in anthocyanin synthesis in the broom sorghum.

• KIEE International Transactions on Electrophysics and Applications
• /
• v.5C no.3
• /
• pp.124-130
• /
• 2005

In this paper, we designed a cylindrical type light source having an electromagnetic principle of inductively coupled plasma, and measured its electrical-optical properties. Using the transformer principle, an electrically equivalent circuit cylindrical type light source was analyzed. According to the parameters of electromagnetic induction, which were diameter of coil with cpO.3$\~$ 1.2mm, number of turns with 4$\~$ 12 turns, distance with 40$\~$ l20mm and RF power with 10$\~$ 150W, the electrical .md optical properties were measured. When the diameter of the coil was cp0.3mm, number of turns was 8 and distance was 40mm, and the maximum brightness of 29,730 cd/m$^{2}$ was shown with RF power l50W. The relationship between electromagnetic induction and plasma discharges was demonstrated using the mode transition from E-mode to H-mode

• Journal of the Korea Convergence Society
• /
• v.11 no.1
• /
• pp.301-308
• /
• 2020

Based on the analysis of fire escape situations in public facility, this study was intended to propose a design of emergency light suitable for fire in public facility. A video analysis was conducted to understand the evacuation situation of public facility because the fire could not be randomized due to the disaster. Through video analysis, we were able to identify inconvenience and necessary needs in avoiding fire in public facility and reflected them in the design of emergency light, etc. As a result of the design of emergency light, the wall type induction lamp had different LED layout structures to minimize the thickness of the product. Ceiling induction lamps have been supplemented for additional installation in corridors of complex structures. The results of this study are designed based on the criteria used in the manufacture of actual emergency light and we intend to explore ways to be practical through further experiment measurements and complementary steps through expert advice.

• Korean Journal of Food Science and Technology
• /
• v.54 no.1
• /
• pp.59-65
• /
• 2022

Curcuminoids in turmeric oleoresin (TO) are known to be effective antioxidants; they exhibit photosensitizing properties under light. In this study, the photoreactive properties of TO and its consequent induction of lipid peroxidation and cytotoxicity were evaluated. TO exhibited photosensitizing activities as evidenced by the reduction of nitro blue tetrazolium and by the decolorization of formazan under light, whereas light-irradiated TO did not enhance the levels of reactive oxygen species. The levels of hydroperoxide and thiobarbituric acid reactive substance (TBARS) were significantly elevated under a fluorescent light (10 W/m²) in corn, canola, and soybean oils containing 10-40 and 20-80 ㎍/mL of TO (p<0.05) but not in olive oil. Canola oil was the most sensitive to photo-oxidation induced by TO. The level of TBARS from linoleic acid in the oil in water system was, however, decreased by TO under light. The cytotoxicity effect of TO on melanoma cells was also substantially enhanced under light.