• Korean Journal of Microbiology
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• v.6 no.4
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• pp.122-130
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• 1968

Action of various wavelengths of visible light on ultraviolet-radiation damage to haploid yeast cells, Saccharomyces cerevisiae 23971, was studied. The results were obtained on the basis of the survival and respiration rates by pre- and post-illuminations of various wavelengths before and after U.V.-irradiations on the yeast cells. Among the wavelengths tested, 635 $m{\mu}$, 429 $m{\mu}$ and white light which caused increase of respiration in pre-treatment alone, induced less resistance to the U. V.-damage than in the control, in both pre- and U.V.-treatment. On the contrary, such wavelengths as 574 $m{\mu}$and 530 $m{\mu}$, showing a weak effect on respiration in pre-treatment increased the susceptability to U.V.-radiation. Photoinactivation was generally obtained by both pre- and post- illuminations along with U.V.-treatment. At 635 $m{\mu}$ the PI rate was the lowest and also a low PI rate was shown at 429 $m{\mu}$. But 429 $m{\mu}$, in the post-treatment of the yeast cells pre-treated by the white light and the darkness respectively, showed the highest PI rate. In both pre- and post- treatment of 574, 530 and 473 $m{\mu}$,the PI rates were high to the same degree. Post-treatments of the wavelengths on U.V.-treated yeasts incubated rather under the white light than the darkness induced lower PI rate. It is assumed that there are great differences in action even of the same wavelength, depending upon the various combination of pre- and post-treatments, and that, moreover, the action of various wavelengths of visible light on U.V.-damage on the cells are concerned with the doses and dose rates of U.V. and visible lights. These observations led to an interpretation that each wavelength of visible light might exert distinctively different effects oil U. V.-damage, mainly causing the inhibition or stimulation of enzymes in the yeast cells.

• Korean Journal of Materials Research
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• v.23 no.2
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• pp.116-122
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• 2013

For fabricating silicon solar cells with high conversion efficiency, texturing is one of the most effective techniques to increase short circuit current by enhancing light trapping. In this study, four different types of textures, large V-groove, large U-groove, small V-groove, and small U-groove, were prepared by a wet etching process. Silicon substrates with V-grooves were fabricated by an anisotropic etching process using a KOH solution mixed with isopropyl alcohol (IPA), and the size of the V-grooves was controlled by varying the concentration of IPA. The isotropic etching process following anisotropic etching resulted in U-grooves and the isotropic etching time was determined to obtain U-grooves with an opening angle of approximately $60^{\circ}$. The results indicated that U-grooves had a larger diffuse reflectance than V-grooves and the reflectances of small grooves was slightly higher than those of large grooves depending on the size of the grooves. Then amorphous Si:H thin film solar cells were fabricated on textured substrates to investigate the light trapping effect of textures with different shapes and sizes. Among the textures fabricated in this work, the solar cells on the substrate with small U-grooves had the largest short circuit current, 19.20 mA/$cm^2$. External quantum efficiency data also demonstrated that the small, U-shape textures are more effective for light trapping than large, V-shape textures.

• Journal of the Korea Fashion and Costume Design Association
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• v.2 no.1
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• pp.113-121
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• 2000

The effect of Sunlight exposure on reducing the microorganism counts in the bedding materials was experimented by using 3 kinds of microorganisms(S. aureus, K. pnenmoniae and E. coli) and 3 kinds of fabrics (cotton, silk and polyester). Counts of the microorganism were examined before and after sunlight exposure. The sunlights were controlled U.V and Daylight D50 using MacBeth artificial light source. The specimens were exposed for 5 min, 10 min and 30 minutes under the $20^{\circ}C$ and 60% R.H, distance is 50cm from the light source. Results were as follows, 1. The reduction rate of the 3kinds of microorganisms was remarkably great under the U.V exposure. The U.V. exposure was very effective way to sterlize the bedding materials in the house care. 2. S. aureus was the most susceptible to U.V. exposure and the sunlight exposure. E. coli was the most resistant to the U.V and the sunlight exposure. 3. The reduction rate of the 3 kinds of fabrics was not significantly different. The polyester is more resistant than the silk and the cotton. Those were shown good reduction rate if all kinds of microorganism under the U.V and daylight.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.4
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• pp.428-434
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• 1995

The purpose of this study is to develop a sanitary aquarium for the safety slices of raw fish by using U.V. light. Water re-circulating system was composed of two tanks. One of the tanks $(90\times45\times45cm\;in\;size),$ was used for rearing fish and the other $(90\times45\times45cm\;in\;size),$ with 37 pieces of corrugated plastic plates was used for the growth of Nitrosomonas and Nitrobacter to remove ammonia from the water. Consequently, bactericidal effects of U.V. light were examined under the controlled condition of water with flow rate 730m1/sec (water flow thickness: 10mm), the width 41cm of water flow route, and the distance 4.75cm from the lamp to its water bottom, and U.V. light 75W (5 lamps). The water of the aquarium tank will be theroetically circulated 1 cycle per 18 min. In these conditions the bactericidal effect was $85\%$ just after passing through U,V. light and 3 log cycle in aquarium tank water. The count of Vibrio parahaemolyticus just after irradiation was decreased by about over than 3 log cycle. Under the irradiation for 72 hours, viable cell counts in both skin and gill of fish reared were decreased into about 2 log cycle, but there was no significant decrease in viscera. When the temperature of the tank was controlled at about $20-23^{\circ}C$ under the same condition, viable cell counts were reduced about 2 log cycle, and fecal coliforms were reduced about 1 log rycle and 3 log cycle in Crassostrea gigas and Mytilus edulis, respectively.

• Transactions on Electrical and Electronic Materials
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• v.15 no.6
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• pp.315-319
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• 2014

In this paper, we investigate visible light stress instability in radio frequency (RF) sputtered a-IGZO thin film transistors (TFTs). The oxygen flow rate differs during deposition to control the concentration of oxygen vacancies, which is confirmed via RT PL. A negative shift is observed in the threshold voltage ($V_{TH}$) under illumination with/without the gate bias, and the amount of shift in $V_{TH}$ is proportional to the concentration of oxygen vacancies. This can be explained to be consistent with the ionization oxygen vacancy model where the instability in $V_{TH}$ under illumination is caused by the increase in the channel conductivity by electrons that are photo-generated from oxygen vacancies, and it is maintained after the illumination is removed due to the negative-U center properties.

• Journal of Astronomy and Space Sciences
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• v.21 no.2
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• pp.73-82
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• 2004

New photometric and spectroscopic solutions of W-type overcontact binary V 417 Aql were obtained by solving the UBV light curves of Samec et al. (1997) and radial-velocity ones of Lu ＆ Rucinski (1999) with the 2003 version of the Wilson-Devinney binary code. In the light curve synthesis the light of a third-body, which Qian (2003) proposed, was considered and obtained about 2.7%, 2.2%, and 0.4% for U, B, and V bandpasses, respectively. The model with third-light is better fitted to eclipse parts than that with no third-light. Absolute dimensions of V417 Aql are determined from our solution as $M_1$= 0.53 $M_{*}$, $M_2$= 1.45 $M_{*}$, $R_1$= 0.84 $R_{*}$, and $R_2$= 1.31 $M_{*}$, and the distance to it is deduced as about 216pc. Our distance is well consistent with that (204pc) derived from Rucinski ＆ Duerbeck's (1997) relation, $M_{v}$ = $M_{v}$(log P, B-V), but is more distant than that (131$\pm$40pc) determined by the Hipparcos trigonometric parallax. The difference may result from the relatively large error of Hipparcos parallax for V 417 Aql.l.

• Journal of Environmental Science International
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• v.5 no.3
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• pp.329-335
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• 1996

This project studies marine Vibrio vulnificus in oysters in the marine environment and attempts to correlate this bacteria's presence within various environmental parameters; we design this study to determine how different storage temperatures affect the survival of V. vuinficus in oysters and whether V. vulnificus is able to persist in oysters after exposure to UV light-disinfected seawater. Experimental depuration systems consist of aquaria containing temperature-controlled seawater treated with UV light and 0.2 ㎛ pore size filtration. Results showed that depuration at temperatures higher than 25℃ caused V. vuinificus counts to increase in oysters. Throughout the process, depuration water contained high concentrations of U vuinificus indicating"that the disinfection properties of UV radiation and 0.2 ㎛ pore size filtration were less than 어e release of V. vuinificus into seawater, In contrast, when depuration seawater was maintained at 10℃, the numbers of V. vuinificus were very little and multiplication in oysters was inhibited.

• Journal of Astronomy and Space Sciences
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• v.5 no.1
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• pp.9-18
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• 1988

Gamma Cassiopeae has been observe at Yonsei University Observatory(YUO) for 31 nights in the period 1983-1987 and a total of 312 UBV observations(104 in each colour) was secured. Light curves of ${\gamma}$ Cas in V, B-V, and U-B have been constructed with the YUO data; among them we present selected light curves of 5 different long nights. Discussed are the general photometric behaviour of ${\gamma}$ Cas, especially in connection with B-V changes, V/R variations of $H\alpha$ and H$\beta$, and high velocity narrow component(hvnc) exhibited in the far UV. Six spectral image sets of $\varepsilon$Per archived on IUE satellite are reduced and their line profiles in C IV and Si IV resonance lines are analyzed to find out any change, but the evidence is unlikely.

• Journal of Arbitration Studies
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• v.24 no.3
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• pp.79-103
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• 2014

In light of increasing international trade in recent years, international arbitration has been more widely used by international parties to resolve their conflicts. Thus, the need for reliable and effective enforcement of foreign arbitral awards has amplified. To facilitate the enforcement of foreign arbitral awards, the New York Convention lists grounds for the refusal of recognition and enforcement in Article V. This paper examines prominent U.S. case law on Article V(1)(b), which is put in place to ensure that arbitration proceedings are conducted properly in accordance with due process requirements: proper notice to parties and an opportunity to a fundamentally fair hearing. This examination of case law conveys that U.S. courts refuse to enforce foreign arbitral awards pursuant to Article V(1)(b) only when due process rights of the party against whom the award is to be enforced are clearly violated by the arbitral tribunal. This paper also reveals that U.S. courts mainly defer to arbitral tribunals' discretion, especially as to evidentiary matters. Therefore, it is predicted that U.S. courts will likely continue to narrowly construe the grounds in Article V to facilitate reliable and effective enforcement of foreign arbitral awards in the U.S.

• Journal of Astronomy and Space Sciences
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• v.11 no.1
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• pp.21-30
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• 1994

VV Cep-type long period spectroscopic-eclipsing binary AZ Cas has been observed for five years, 1985 Oct~1990 Feb, UBV at the Ilsan Station of Yonsei University Observatory. A total of 431 observations (U=129, B=142 and V=160) are made for 86 nights. Instrumental differential UBV and B-V light curves made with these observations cover phases nearly a half of one period. There is no appreciable light variation in V but in other two passbands a gradual decrease of the brightness is clearly noticed. The loss of light in B resulted in a reddening in $\Delta(B-V)$ by + 0.06 at phases between 0.4~0.5 as compared with that of at phase ~0.1. This intrinsic reddening arouses a question why at the orbital phase of the transit of a hot star in front of a cool M supergiant the heating of the facing hemisphere of M supergiant by the strong radiation from the B stat is absent. With regard to this unusual situation we propose a hypothesis that a large amount of gas stream of low temperature ejected from the surface of M supergiant component towards the B star dominates the brightness of B star and the reflection effect.