• Animal Bioscience
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• v.36 no.5
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• pp.731-739
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• 2023

Objective: This study was to evaluate the interaction of three different light-emitting diode (LED) light colors (white, green, and blue) and three intensities (5, 10, and 15 lx) on slaughter performance, meat quality and serum antioxidant capacity of broilers raised in three-layer cages. Methods: A total of 648 (8-days-old) male broiler chicks (Cobb-500) were randomly assigned in 3×3 factorially arranged treatments: three light colors (specifically, white, blue, and green) and three light intensities (namely, 5, 10, and 15 lx) for 35 days. Each treatment consisted of 6 replicates of 12 chicks. The test lasted for 35 days. Results: The semi-eviscerated weight percentage (SEWP) in 5 lx white was higher than that in 15 lx (p<0.01). The eviscerated weight percentage (EWP) (p<0.05) and water-loss percentage (WLP) (p<0.01) decreased in 10 lx white light than those in green light. Under blue light, the content of hypoxanthine (Hx) in muscle was lower than that under white and green light (p<0.01). The content of malondialdehyde (MDA) in 15 lx blue light was higher than that in 10 lx green light (p<0.05). Light color had an extremely significant effect on thigh muscle percentage, WLP, Hx, and crude protein content (p<0.01). Light intensity had a significant effect on SEWP (p<0.05), EWP (p<0.05), lightness (L^*) value (p<0.05), WLP (p<0.01), and the contents of superoxide dismutase (p<0.05), MDA (p<0.01), glutathione peroxidase (p<0.01). Conclusion: Using white LED light with 10 lx light intensity can significantly improve the chicken quality of caged Cobb broilers, improve the content of inosine acid in chicken breast and enhance the antioxidant capacity of the body. We suggest that the broiler farm can use 10 lx white LED light source for lighting in 8 to 42 days.

• Current Optics and Photonics
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• v.1 no.4
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• pp.358-363
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• 2017

In this study, we present a detailed investigation of luminescence properties of a blue light-emitting diode using InGaN/GaN (indium component is 17.43%) multiple quantum wells as the active region grown on patterned sapphire substrate by low-pressure metal-organic chemical vapor deposition (MOCVD). High-resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman scattering (RS) and photoluminescence (PL) measurements are employed to study the crystal quality, the threading dislocation density, surface morphology, residual strain existing in the active region and optical properties. We conclude that the crystalline quality and surface morphology can be greatly improved, the red-shift of peak wavelength is eliminated and the superior blue light LED can be obtained because the residual strain that existed in the active region can be relaxed when the LED is grown on patterned sapphire substrate (PSS). We discuss the mechanisms of growing on PSS to enhance the superior luminescence properties of blue light LED from the viewpoint of residual strain in the active region.

• Journal of Environmental Science International
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• v.27 no.10
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• pp.821-829
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• 2018

This study was conducted to examine the influence of Light-Emitting Diode (LED) light quality in urban agricultural plant factories on the growth and development of Seolhyang strawberry daughter plants in order to improve the efficiency of daughter plant growth and urban agriculture. LED light quality by demonstrated that above-ground growth and development were greatest for daughter plant 2. Daughter plant 1 showed the next highest growth and development, followed by daughter plant 3. Among the different qualities of LED light, the stem was thickest and growth rate of leaves was highest for R + B III (LED quality: red 660 nm + blue 450 nm/photosynthetic photon flux density (PPFD): $241-243{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and lowest for R (red $660nm/115-117{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). Plant height, leaf width, petiole length, and the leaf growth rate were highest for W (white fluorescent lamp/$241-243{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and lowest for R + B I (red 660nm+blue 450nm/$80-82{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). For above-ground growth and development, as the plants surpassed the seedling age, mixed light (red + blue), rather than monochromatic light (red or blue), and higher PPFD values tended to increase development. Regarding the quality of the LED light, daughter plant 2 showed the highest chlorophyll content, followed by daughter plant 1, and daughter plant 3 showed the least chlorophyll content. When the wavelength was monochromatic, chlorophyll content increased, compared to that when PPFD values were increased. Mixed light vitality was highest in daughter plant 2, followed by 1, and 3, showed increased photosynthesis when PPFD values were high with mixed light, in contrast to the results observed for chlorophyll content.

• Journal of Marine Bioscience and Biotechnology
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• v.8 no.1
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• pp.24-29
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• 2016

Microalgae are considered as superior biodiesel producers, because they could effectively produce high amount of lipid with fast growth rate. In this study, Chlorella vulgaris was exposed to various light wavelengths (${\lambda}_{max}$ 470 nm, ${\lambda}_{max}$ 525 nm, and ${\lambda}_{max}$ 660 nm) using light emitting diodes (LEDs) to examine effect of light quality on their growth and fatty acid production in 0.4-L bubble column photobioreactors. Fluorescent lamps were also used as polychromatic light sources (control). From the results, biomass productivity was varied by light wavelength from 0.05 g/L/day to 0.30 g/L/day. Maximum biomass productivity was obtained from red LED among tested ones. We also observed that contents of oleic acid and linolenic acid, which affect biodiesel properties, were significantly changed depending on supplied wavelength. These results indicated that production of algal biomass, and fatty acid content and productivity could be improved or controlled by supplying specific light wavelength.

• Journal of Korean Society of Forest Science
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• v.99 no.5
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• pp.750-754
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• 2010

Among the environmental conditions employed in micropropagation, light quality plays an important role in growth, specially morphogenesis and photosynthesis. The effect of radiation quality (350-740 nm) on the development and growth of zygotic embryos and in vitro plantlets of open-pollinated chestnut (Castanea crenata S. et Z.) were studied. Two types of explants were exposed for 4 weeks to cool white (W, as control), monochromatic red (R, peak emission 650 nm), monochromatic blue (B, peak emission 440 nm), red+blue (R+B, 1:1), or red+far-red (R+Fr, 1:1, far-red peak emission 720 nm) radiation from a light-emitting-diode (LED) system. While the zygotic embryos showed positive photoblastic behavior, their germination was inhibited by blue radiation. Hypocotyl elongation and root development were promoted by red radiation. The emergence of primary leaf and its expansion were faster under blue than under red radiation. In the plantlets, red and red+far-red radiation significantly increased the formation and growth of the root, whereas blue light reduced rooting. Therefore, radiation quality appears to influence some steps in the development of zygotic embryos and plantlets in the chestnut.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.1
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• pp.64-68
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• 2014

This paper introduces the use of a crown-shaped (CR) lens to effectively diffuse the light from a light-emitting diode (LED) without any loss in the light intensity, in contrast to polymer-bulb-type diffusers. The diffusion lens was designed based on the Snell's law, which describes the physical path of a ray passing through the boundary between different media. CR lenses were fabricated by polydimethylsiloxane (PDMS) casting and UV-embossing processes, which used a pre-designed metal mold and UV-curable resin, respectively. Through experiments and optical evaluations, it was verified that the newly proposed CR lens not only decreased the vertical light strength and glare effect from an LED light source but also improved the diffusion characteristics while maintaining the quality of the LED's light intensity.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.1
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• pp.36-43
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• 2023

To establish a culture system with enhanced cellular nutrition, we investigated the effects of light quality (blue, 450 nm; yellow, 590 nm; and red, 630 nm) of a light-emitting diode (LED) on the biochemical composition of Tetraselmis suecica and T. tetrathele. The protein content of both species was higher (42-69%) than the content of other biochemical substances under all wavelengths. Carbohydrate, protein, and lipid contents were higher under the yellow wavelength, which showed a low growth rate, than those under other wavelengths. The contents of all biochemical substances were low under the red wavelength, which showed a high growth rate. These results indicated that protein synthesis occurs in response to decreased cell division rate, while lipid and carbohydrate synthesis occurs owing to altered chemical composition and enzymatic activity. Therefore, we suggested a two-phase LED culture system, which emitted red LED during the early-middle exponential phase and yellow LED during the late exponential and stationary phases, to increase the yield of useful biochemical substances of T. suecica and T. tetrathele.

• Korean Journal of Food Science and Technology
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• v.47 no.6
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• pp.785-788
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• 2015

In this study, the effect of light irradiation on tyrosinase activity during storage in a low temperature incubator was investigated, with the goal of identifying the appropriate wavelength and intensity of light for inhibiting tyrosinase activity. Fluorescent light and blue light emitting diode (LED) irradiation were found to inhibit tyrosinase activity. In particular, tyrosinase activity was significantly inhibited under high intensity blue LED irradiation, suggesting that the activity of tyrosinase present in vegetables or fruits might be inhibited by LED irradiation. Therefore, blue LED irradiation during food storage and the distribution stage would be useful for ensuring good quality of food, owing to the inhibition of the enzymatic browning reaction.

• Journal of Auto-vehicle Safety Association
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• v.11 no.4
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• pp.16-21
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• 2019

In recent years, most automobile manufacturers have been using slim light source images to imprint their own brand image and identity. A light guide type lamp is widely used for making these kinds of a slim light source image. A light guide lamp means using a light emitting diode light source at one end of a long cylindrical pipe. The light from the light emitting diode source moves through the pipe by total reflection principle. Moving light is sent forward by various optic structures which is applied in the cylindrical pipe. However, the light guide lamp has a problem that the image of the light differs depending on the viewing direction, and in some cases there is dark section. It means light guide has low quality about lighting image. In this paper, trying to improve the fundamental problems of the light guide mentioned above by using various triz methods. Through functional modeling, estimating the factors affecting the light in the light guide lamp and make various ideas to improve the lighting image using the chain effect cause analysis, function oriented search scientific database techniques. Using these kinds of various TRIZ methods, finally find solutions that can improve the brightness and lighting uniformity of the light guide lamp. The ideas obtained in this paper were applied to actual vehicle development, and several patents achievements were obtained. In conclusion, it is proved that TRIZ method is useful for making ideas in actual automobile industrial field and is also a useful method for acquiring patent.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.441-443
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• 1995

A new optical-resistive voltage divider, which consists of light emitting diode, optic fiber, PIN-photo diode and a high qualify shielding resistive divider, whose total response time is 7.35 [ns], has been obtained. The optical to electrical signal converter was constructed with GaAsP series light emitting diode. The response characteristics have been verified by applying the Marx impulse voltage generator experimentally. Comparing with the performance of conventional resistive voltage divider, the characteristics of the proposed optical-resistive voltage divider are more excellent in step response and less sensitive to electromagnetic interference.