• Title/Summary/Keyword: light effect

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Effect of Alteration of Light-Darkness Cycle on Nitrogen Retention in the Rat (주야 변경이 흰쥐의 체내 질소 보유에 미치는 영향)

  • Kim, Mi-Kyung
    • Journal of Nutrition and Health
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    • v.16 no.4
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    • pp.273-280
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    • 1983
  • The effect of alteration of light-darkness cycle on the protein metabolism was studied in the rat. The light-darkness cycle was altered either every 3 or 9 days, and animals consumed diets containing 8 or 25% casein. The results were summarized as follows : 1) Food consumptions and body weight gains of the 25% casein groups were higher than those of the 8% casein groups, and, among the animals consumed 25% casein diet, the light-darkness cycle altered group had lower food consumption and body weight gain than the unaltered group. 2) Weights of liver and adrenal gland per l00g body weight were not different with the dietary protein levels, but, at the end of experimental period, the 8% casein diet group of which light-darkness cycle altered every 9 days had the smallest liver weight and the largest adrenal gland weight. 3) Liver nitrogen and plasma protein concentrations of the 25% casein groups were slightly higher than those of the 8% casein groups. 4) Percentages of nitrogen retention of the 25% casein groups at period III were slightly lower in the light-darknerr cycle altered animals than that of the unaltered group.

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Effect of light source on depth of cure and polymerization shrinkage of composites

  • Na, Joon-Sok;Oh, Won-Mann;Hwang, In-Nam
    • Proceedings of the KACD Conference
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    • 2001.11a
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    • pp.578.1-578
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    • 2001
  • The aim of this study was to evaluate the efficiency of the recently introduced light curing units to polymerize a light curing resin composite. Four light curing units XL 3000, Optilux 500 for halogen light source, Apollo 95E for plasma arc and Easy cure for LED (blue-light Emitting Diode) were evaluated. Radiometer was used for measure the light intensity.(omitted)

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Numerical Study on the Effect of Volume Change of Light-Off Catalyst on Light-Off Performance (저온활성촉매변환기의 체적변화가 활성화 성능에 미치는 영향에 관한 수치적 연구)

  • 정수진;김우승
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.6
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    • pp.87-100
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    • 2000
  • HC and CO emissions during the cold start contribute the majority of the total emissions in the legislated driving cycles. Therefore, in order to minimize the cold-start emissions, the fast light-off techniques have been developed and presented in the literature. One of the most encouraging strategies for reducing start-up emissions is to place the light-off catalyst, in addition to the main under-body catalyst, near the engine exhaust manifold. This study numerically consider three-dimensional, unsteady compressible reacting flow in the light-off and under body catalyst to examine the impact of a light-off catalyst on thermal response of the under body catalyst and tail pipe emission. The effect of flow distribution on the temperature distribution and emission performance have also been examined. The present results show that flow distribution has a great influence on the temperature distribution in the monolith at the early stage of warm-up process and the ultimate conversion efficiency of light-off catalyst is severly deteriorated when the space velocity is above $100,000hr^{-1}$.

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Implementation of Digital Light Drawing System based on Stereo Vision (스테레오 비전 기반 Light Drawing 시스템 구현)

  • Park, Won-Bae;Park, Chang-Bum;Paik, Doo-Won
    • The Journal of the Korea Contents Association
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    • v.10 no.2
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    • pp.130-137
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    • 2010
  • Light Drawing is a photographic technique which exposures are made at night or in a darkened room usually by moving a hand-held light source[1]. Due to the limitations of equipment and environment, users having difficulty in drawing a picture in 3D space. If user take a light drawing, they need a camera that have function and darkened environment. Alternative solution is that we can make a light drawing picture by using the computer drawing tool as in Photoshop. Nevertheless, this solution will let the User lose their interest in drawing because this solution cannot synchronize between the real action of human hand motion and the electronic input devices such as mouse and keyboard. This paper proposed a digital content that can make light drawing easier. We used a digital content that will facility Light Drawing easier. We can measure the light spot position by using the stereo camera. Based on the measured position of the light spot, we reproduce light drawing in virtual space by using drawing effect method.

Effect of Extreme Light Regime on Production and Characteristics of Egg in Laying Geese

  • Wang, S.D.;Wang, C.M.;Fan, Y.K.;Jan, D.F.;Chen, L.R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.8
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    • pp.1182-1185
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    • 2002
  • The objective of this study was to investigate the effect of long light regime (20 h light and 4 h dark, 20L:4D) and short light regime (4 h light and 20 h dark, 4L:20D) on egg production and egg characteristics of laying geese. Thirty-six laying birds, 4 replicates of 3 birds per treatment were allotted to three light regimes, i.e., 20L:4D, 4L:20D, and natural light (NAT) from March 7 to June 20. Results showed that the geese in 20L:4D consumed 54 g less feed per goose daily and laid 17.5 less eggs per goose (p<0.05) comparing to those in 4L:20D. The number of days from initiation of light treatment till cease of laying was 22 days shorter (p<0.05) in 20L:4D comparing to that in NAT. Five geese (41.7%) in 4L:20D kept laying by the end of applying light regime. Weight and surface area of the eggs in 4L:20D were greater (p<0.05) comparing to those in the other two light regimes. It is concluded that the period of egg production in goose could be manipulated by light regime in the ways such as using short light regime of 4 h light daily to prolong egg production through summer and using long light regime of 20 h light daily to induce cease of egg production.

The Blocking Effect of Sunscreen Materials on Blue Light (자외선 차단제의 블루라이트 차단효과에 관한 연구)

  • Chung, Sang Uk;Lee, Si Eun;Choi, Sun Young;Moon, Kwon Ki;Lim, Sora;Kim, Hae Kyoung;Park, Jong Ho
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.44 no.2
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    • pp.183-189
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    • 2018
  • Blue light is the highest energy wavelengths in the visible light region and induces skin aging and active oxygen. Studies on harmful mechanism of skin are under way. Research on blue light blocking materials in cosmetics and formulation studies are in the early stage, and the test methods related to blue light blocking measurement are not established. The blue light blocking efficacy was established by referring to the test method of the sunscreen in vitro test(COLIPA guideline, ISO 24443, FDA Final Rule on Sunscreen Testing and Labeling). The blue light blocking effect was evaluated for 17 kinds out of 27 kinds of sunscreen raw materials suggested in KFDA guideline. The Effect was 14.97% for zinc oxide and 16.32% for bishexyloxyphenol methoxyphenyl triazine, 35.47% for methylene bis-benzotriazolyltetramethylbutylphenol, and 65.96% for titanium dioxide. In addition, the effect of micro-titanium dioxide was twice as high as that of the nano-titanium dioxide. The results suggested that the light blocking effect test method can be used to search for blue light blocking materials and study cosmetic formulations.

Study on the UV illuminance to improve on attraction effect of fluorescent bait cage for pots (통발용 형광 미끼통의 유인 효과 개선을 위한 자외선 조도에 관한 연구)

  • Chang, Ho-Young
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.4
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    • pp.316-326
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    • 2011
  • In this study, the entrapped number is investigated on the UV light with different illuminance to fluorescent bait cage for swimming crab in order to find the appropriate illuminance which has the best attraction effect of fluorescent bait cage for pots. In addition, preference to the light, arrival time and residence time at light area are compared and analyzed to fluorescent bait cage and non-fluorescent bait cage for American lobster at the UV light and ordinary light according to the illuminance condition. Pot with red non-fluorescent bait cage at the no lighting (<0.01lux), pot with blue fluorescent bait cage at the 20W UV lighting (0.16lux) and pot with blue fluorescent bait cage at the 30W UV lighting (0.22lux) were soaked for 6 hours and the entrapped number of swimming crab was examined. The mean entrapped number of swimming crab in pot with red non-fluorescent bait cage at the no lighting (<0.01lux) was 1.0, but the mean entrapped number of swimming crab in pot with blue fluorescent bait cages at the 20W UV lighting (0.16lux) and 30W UV lighting (0.22lux) were 1.4 and 0.4, respectively (P<0.05). The rate of preference to the blue fluorescent bait cage at the UV lighting shows 1.6-4.8 times higher than that of preference to the red non-fluorescent bait cage at the ordinary lighting. In addition, The rate of preference to the blue fluorescent bait cage at the UV lighting is higher when the illuminance of ordinary light is same as or is lower than that of UV light (P<0.05). However, the preference to the light depending on gender shows no significant difference (P>0.05). The arrival time to UV light area of lobster is shown as 1.2-2.4 times faster than that to ordinary light area. Generally, it is shown that arrival time to UV light area is faster than the arrival time to ordinary light area when the illuminance of ordinary light is the same as or lower than that of UV light (P<0.05). However, arrival time to the light area depending on gender shows no significant difference (P>0.05). The residence time at UV light area of lobster is 1.2-1.7 times longer than that at ordinary light area. The residence time depending on different illuminance of ordinary light and genders showed no significant difference (P>0.05).

TWO UNITARY LIGHT CURVES OF AR LACERTAE IN 1984

  • Park, Hong-Suh;Chen, Kwan-Yu
    • Journal of The Korean Astronomical Society
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    • v.23 no.2
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    • pp.106-111
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    • 1990
  • Photoelectric observation in 1984 shows light variation outside eclipses. The effect of the changing ambient temperature on the light curves were studied. Difficulty of studying and unitary, or mean, light curve of AR Lac is stressed.

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Effects of light-emitting diodes on protoplast regeneration from gametophytic cells of the commercial kelp Undaria pinnatifida (Laminariales, Phaeophyceae)

  • Avila-Peltroche, Jose;Won, Boo Yeon;Cho, Tae Oh
    • ALGAE
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    • v.37 no.2
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    • pp.163-174
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    • 2022
  • Light-emitting-diodes (LEDs) are a lighting source useful for the precise evaluation of light quality effect on biological systems. Despite the importance of light spectra on the regeneration of land plant protoplasts ("naked cells"), this factor has not been tested yet on protoplasts from multicellular algae. This study reports on the effects of pure primary colors (red, blue, and green), dichromatic (red plus blue, RB, 1 : 2) and white LEDs on protoplast regeneration from male and female Undaria pinnatifida gametophytes. We also evaluated the effect of different light spectra on pigment composition (chlorophyll a, chlorophyll c, and fucoxanthine), and the light intensities under the best condition on the regeneration process. In the early stages, blue or RB LEDs increased the percentage of dividing female protoplasts, whereas red, blue, and RB LEDs enhanced that of dividing male protoplasts. In the later stages, RB LEDs showed a positive effect only on the percentage of multiple rhizoid-like protrusions (male gametophyte). They also increased the final area of both regenerated gametophytes. The LEDs did not affect pigment composition in female gametophytes. In male gametophytes, in contrast, they reduced chlorophyll c, while blue, RB, and green LEDs decreased fucoxanthin. Under RB LEDs, the optimal light intensity was 80 µmol photons m-2 s-1 for female gametophytes and 40 to 60 µmol photons m-2 s-1 for male gametophytes. Our results suggest that dichromatic LED illumination (red-blue) improves regeneration of U. pinnatifida gametophyte-isolated protoplasts. Thus, dichromatic LEDs might a suitable light source for enhancing protoplast regeneration in brown seaweeds.

Subjective Evaluation of Glare for Blinking and Colors of Vertical LED Lighting (수직형 LED 조명의 색상 및 점멸에 따른 눈부심 주관평가)

  • Jung, Hyun-Ji;Kim, In-Tae;Choi, An-Seop
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.1
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    • pp.22-30
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    • 2015
  • Currently, in South Korea, 'Light Pollution Prevention Act by Artificial Lighting' has been enforced. For advertising lighting, it is limited based on only the light-emitting luminance. Luminance is a concept related to the glare. Not only the luminance of the light source, but also glare is affected depending on some situations like blinking, luminance contrast, background illuminance. This study conducted glare subjective evaluation with brightness, color, and blinking by looking at the LED lighting box. The results showed that the glare indexes were higher about 2 times in a decrease of background illuminance from 100lx to 0lx. The glare index of R, G, B light was higher than that of white light. The average glare index of the blue light was higher about 8 times compared to 2,700K. And the blink rate had little effect on the glare, but it affected the irritation. Therefore, the glare effect of light color and blinking needs to be considered for the standard of luminous environment.