• Title/Summary/Keyword: warm white

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Application of White Light Emitting Diodes to Produce Uniform Scions and Rootstocks for Grafted Fruit Vegetable Transplants (과채류 접목 시 균일한 접수와 대목 생산을 위한 백색 LED의 적용)

  • Hwang, Hyunseung;Chun, Changhoo
    • Journal of Bio-Environment Control
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    • v.31 no.1
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    • pp.14-21
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    • 2022
  • Uniform scions and rootstocks should be produced to ensure grafting success. Light quality is an important environmental factor that regulates seedling growth. The effects of warm- and cool-white light emitting diode (LED) ratios on seedling growth were investigated. Scions and rootstocks of cucumber, tomato, and watermelon were grown in a closed transplant production system using LED as the sole lighting source. The LED treatments were W1C0 (only warm-white), W1C1 (warm-white: cool-white = 1:1), W3C1 (warm-white: cool-white = 3:1), and W5C2 (warm-white: cool-white = 5:2). The seedlings grown in W1C1 had the shortest hypocotyls, and the seedlings grown in W1C0 had the longest hypocotyls among the three tested vegetables. The hypocotyls of watermelon scions, watermelon rootstocks, and tomato rootstocks were shortest in W1C1, followed by those in W3C1, W5C2, and W1C0, but there was no significant difference between W3C1 and W5C2, which remained the same as the ratio of cool-white LEDs increased. In addition, tomato scions had the first and second longest hypocotyls in W1C0 and W3C1, respectively, and the shortest hypocotyls in W5C2 and W1C1, along with W5C2 and W1C1, although the difference was not significant. The stem diameter was highest in W1C0 except for tomato seedlings and rootstocks of watermelon. The shoot fresh weight of scions and rootstocks of cucumber and watermelon and the root fresh weight of cucumber scions were lowest in W1C1. These results indicated that different ratios of LED lighting sources had a strong effect on the hypocotyl elongation of seedlings.

Vegetative Growth Characteristics of Phalaenopsis and Doritaenopsis Plants under Different Artificial Lighting Sources

  • Lee, Hyo Beom;An, Seong Kwang;Lee, Seung Youn;Kim, Ki Sun
    • Horticultural Science & Technology
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    • v.35 no.1
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    • pp.21-29
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    • 2017
  • This study was conducted to determine the effects of artificial lighting sources on vegetative growth of Phalaenopsis and Doritaenopsis (an intergeneric hybrid of Doritis and Phalaenopsis) orchids. One - month - old plants were cultivated under fluorescent lamps, cool - white light - emitting diodes (LEDs), or warm - white LEDs at 80 and $160{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. The blue (400 - 500 nm) : green (500 - 600 nm) : red (600 - 700 nm) : far - red (700 - 800 nm) ratios of the fluorescent lamps, cool-white LEDs, and warm-white LEDs were 1 : 1.3 : 0.8 : 0.1, 1 : 1.3 : 0.6 : 0.1, and 1 : 2.7 : 2.3 : 0.4, respectively. Each light treatment was maintained for 16 weeks in a closed plant-production system maintained at $28^{\circ}C$ with a 12 h photoperiod. The longest leaf span, as well as the leaf length and width of the uppermost mature leaf, were observed in plants treated with warm-white LEDs. Plants grown under fluorescent lamps had longer and wider leaves with a greater leaf span than plants grown under cool-white LEDs, while the maximum quantum efficiency of photosystem II was higher under cool-white LEDs. The vegetative responses affected by different lighting sources were similar at both 80 and $160{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Leaf span and root biomass were increased by the higher light intensity in both cultivars, while the relative chlorophyll content was decreased. These results indicate that relatively high intensity light can promote vegetative growth of young Phalaenopsis plants, and that warm - white LEDs, which contain a high red-light ratio, are a better lighting source for the growth of these plants than the cool-white LEDs or fluorescent lamps. These results could therefore be useful in the selection of artificial lighting to maximize vegetative growth of Phalaenopsis plants in a closed plant - production system.

Effect of Lu3Al5O12:Ce3+ and (Sr,Ca)AlSiN3:Eu2+ Phosphor Content on Glass Conversion Lens for High-Power White LED

  • Lee, Hyo-Sung;Hwang, Jong Hee;Lim, Tae-Young;Kim, Jin-Ho;Jeon, Dae-Woo;Jung, Hyun-Suk;Lee, Mi Jai
    • Journal of the Korean Ceramic Society
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    • v.52 no.4
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    • pp.229-233
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    • 2015
  • Currently, the majority of commercial white LEDs are phosphor converted LEDs made of a blue-emitting chip and YAG yellow phosphor dispersed in organic silicone. However, silicone in high-power devices results in long-term performance problems such as reacting with water, color transition, and shrinkage by heat. Additionally, yellow phosphor is not applicable to warm white LEDs that require a low CCT and high CRI. To solve these problems, mixing of green phosphor, red phosphor and glass, which are stable in high temperatures, is common a production method for high-power warm white LEDs. In this study, we fabricated conversion lenses with LUAG green phosphor, SCASN red phosphor and low-softening point glass for high-power warm white LEDs. Conversion lenses can be well controlled through the phosphor content and heat treatment temperature. Therefore, when the green phosphor content was increased, the CRI and luminance efficiency gradually intensified. Moreover, using high heat treatment temperatures, the fabricated conversion lenses had a high CRI and low luminance efficiency. Thus, the fabricated conversion lenses with green and red phosphor below 90 wt% and 10 wt% with a sintering temperature of $500^{\circ}C$ had the best optical properties. The measured values for the CCT, CRI and luminance efficiency were 3200 K, 80, and 85 lm/w.

Influence of Fluxing Agents in Sr3SiO5:Eu2+ Phosphors for Fabrication of Warm White Light Emitting Diodes (따뜻한 백색 LED의 제조를 위한 Sr3SiO5:Eu2+ 형광체에서의 융제 첨가 영향)

  • Kim, Hyun-Ho;Chung, Kang-Sup;Lee, Seoung-Won;Kim, Byoung-Gyu
    • Journal of the Korean Ceramic Society
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    • v.49 no.1
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    • pp.105-110
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    • 2012
  • In this paper, a yellow phosphor $Sr_3SiO_5:Eu^{2+}$ that emits efficiently at the 450 nm excitation for warm white LED is studied. In addition, the effects of various flux $BaF_2$, $NH_4Cl$ on the emission spectra were investigated. The samples were synthesized through conventional solid state reaction under reducing atmosphere of 95% $N_2$-5% $H_2$ mixture at the high temperature. All phosphors showed a excitation band from 450 nm and broad band emission peaking at region of 580 nm. The optimal concentration of $BaF_2$ flux is 3 wt% for $Sr_3SiO_5$ with doping 0.05mol Eu phosphors fired in a reductive atmosphere. The phosphor showed highest emission peaking at 582 nm.

The Effects of Heat Application on the Immune Activities of the Human Body

  • Lee, Sang-Bin;Park, Joo-Hyun;Kim, Yong-Nam;Lee, Byoung-Hee;Yoon, Jung-Gyu;Yoo, Kyoung-Tae;Lee, Suk-Hee;Kim, Sung-Joong;Lee, Mi-Joung
    • Journal of International Academy of Physical Therapy Research
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    • v.1 no.1
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    • pp.19-25
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    • 2010
  • The purpose of this study was to determine the effects of heat application on the immune activities of the human body. To exam, furthermore, the immune effect from the healthy volunteer(male:15, female:15) by monitoring changes of immune substances such as various leukocytes[total white blood cell(WBC), eosinophil, neutrophil, basophil, monocyte, and lymphocyte], a comparative study with warm water immersion($40.8{\pm}0.3^{\circ}C$) and infrared(250W) was carried out. The plasma analysis showed that the count of white blood cell, eosinophil, and neutrophil were elevated in warm water immersion- or infrared. stimulated group compared with control group. However, the count of basophil was decreased in both warm water immersion- and infrared-stimulated group than control group. Therefore, these results suggest that the thermostimulation improved immune activity.

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488 cases analysis of tongue characteristic from case record monographs of Warm disease in Qing Dynasty (488례청대온병의안적설상분석)

  • Li, Ya;Wang, Shenghua;Hou, Yangfang;Guan, Junda;Liang, Rong
    • Journal of Korean Medical classics
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    • v.19 no.3
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    • pp.427-431
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    • 2006
  • From 51 monographs of case record in Qing Dynasty, we chose 29 monographs in which tongue diagnosis applied to Warm disease. Then extracted all the case records and got 488 cases from them. In according to the classification of tongue diagnosis in teaching material of TCM diagnosis of higher TCM schools education, we had a statistic analysis on the 488 cases. Results show that the recording rate of tongue coating was highest, 65.16%. From high to low sequentially, the frequency of different fur was yellow fur, white fur and black fur. During $1850{\sim}1911$ of Qing Dynasty, the description of tongue coating changed that the proportion of white fur, yellow fur and compound fur was increased. On the contrary, the proportion of black fur was decreased. The recording rate of the color of tongue was 23.16%, in which the rate of red tongue and crimson tongue were higher. The recording rate of fur character was 37.7%. During $1850{\sim}1911$ of Qing Dynasty, the recording rate of greasy fur was increased to the first. The application of tongue diagnosis involves the warm-heat species of Warm Disease, damp-heat species of Warm Disease and pestilence.

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The Color Temperature Flexibility-typed LED Lighting Control System (색온도 가변형 LED 조명제어시스템)

  • Kim, Hye-Myeong;Yang, Woo-Seok;Cho, Young-Seek;Park, Dae-Hee
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.2
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    • pp.284-288
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    • 2015
  • The color temperature flexibility-typed Lighting Emitting Diode(LED) lighting control system proposed in this thesis employs Pulse Width Modulation(PWM) technique to control the brightness of LED lighting. The LED lighting used as a light source has 20W downlight composed of two types of LED chips: one is Warm White and the other is Cool white. One multi-sensor module consisting an infrared sensor, an illumination sensor, and a temperature sensor was made, to which Bluetooth wireless communication technique was applied to enable a smartphone application to control lighting brightness and identify the information collected from the sensor. CS-1000, a spectroradiometer, was used to measure LED dimming control and the changing values of a color temperature in eight steps. According to a test, it was found that it was possible to change a color temperature from 3187K of Warm White LED to 5600K of Cool White LED.

Implementation of LED Dimming System Using Bluetooth and Smartphone (Bluetooth와 Smartphone을 이용한 LED 디밍 시스템 구현)

  • Yang, Woo-Seok;Kim, Hye-Myeong;Cho, Young-Seek;Park, Dae-Hee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.1
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    • pp.64-68
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    • 2015
  • In this paper, LED lighting system is realized by using Bluetooth wireless communications and smartphones. A bluetooth module with a lighting control function is manufactured by miniaturizing a development board of TI company and the volume of LED dimming system as a whole is reduced. And a trial product is materialized by designing a hardware composed of the manufactured bluetooth module, LED down light equipped with degree warm white and cool white, and 2-channel LED driver; and LED dimming software. The materialized trial product is controled in terms of the brightness and color temperature of LED light source using an application of a smartphone. The experiment showed that the users can easily control the intensity of illumination of LED light source by using the scroll bar of the applications of smartphones. In addition, the color temperatures of both warm white and cool white can be controlled, and when the color temperature of the trial product using the manufactured bluetooth module is compared with that of a trial product of TI company, they show the same color temperatures.

Novel Phosphors for UV Excitable White Light Emitting Diodes

  • Liu, Ru-Shi;Lin, Chun-Che;Tang, Yu-Sheng;Hu, Shu-Fen
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1343-1346
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    • 2008
  • $KSrPO_4$ and $Sr_3(Al_2O_5)Cl_2$ phosphors doped with $Eu^{2+}$ emit a blue and orange-yellow luminescence under ultraviolet (UV) excitation at ~ 400 nm, respectivel, which can be used for making white light emitting diodes.

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Consideration of the Urticaria (은진에 대한 문헌적 소고)

  • Na Hyun Uk;Lee Kwang Gyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.5
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    • pp.1133-1140
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    • 2003
  • Clinical feature of the urticaria is characterised by sudden appearance on the certain positions of the body, scarlet or light yellow, enlarging and merging into stretches with scraching. The most common menifestations are burning heat, severe itching, fever, abdominal pain etc. It Is classified on the basis of the color. There are red and white urticaria in the classics of the Oriental medicine. Red urticaria is caused by warm-heat evil on the other hand white urticaria is caused by cold-wetness evil. It is advisable to follow the therapeutic principles of expelling warm-heat and cold-wetness evils, regulating yin-yang.