• Journal of Bio-Environment Control
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• v.25 no.1
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• pp.42-48
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• 2016

Angelica gigas, belonging family Apiaceae, is a perennial and famous medical plant growing in Korea, Japan, and China. The aims of this study was to analyze the growth and accumulated Decursin and its precursor Decursinol angelate of A.gigas grown under fluorescent lamp and LED. A. gigas 'Manchu' were sowed and managed for seedlings stage in a glass house for 4 weeks. One hundred twenty seedlings with 3 true leafs were transplanted at an ebb & flow system with fluorescent lamp and LED [red: peak wavelength 660nm, blue: peak wavelength 455 nm, white = 3:2:4 ratio] irradiated at $180{\pm}7{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ at the top of plant canopy for 5 weeks. The number of leaves increased by 13.5% in the LED treatment, though it is not statistically significant. Leaf length/width ratio of A. gigas grown under the fluorescent lamps was 24% bigger than the LED treatment and also the stem was 13% larger. Maximum root length was similar to both groups. Fresh weight and dry weight of shoots grown under the LED increased by 50% and 42% and the both weights of roots increased by 125% and 45%, respectively. The contents of Decursin and Decursinol angelate grown under the florescent lamps were larger than LED by 188% and 27% in shoot and 78% and 8% in root. The contents of Decursin and Decursinol angelate per plant grown under LED and florescent lamps were 132mg and 122mg. In conclusion, functional materials in A. gigas were increased by florescent light and its growth was promoted by LEDs light.

• Resources Recycling
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• v.29 no.3
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• pp.61-74
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• 2020

This study was conducted to improve the recycling process of waste fluorescent lamp, and investigate the possibility of using the waste fluorescent lamp glass as a raw material for glass beads, the leaching method of rare earth from the waste phosphor powder, and the possibility of solvent extraction of rare earth from the rare earth leaching solution. The waste phosphor contained 28.9% yttrium oxide, 3.46% cerium oxide, 1.95% europium oxide, 1.76% terbium oxide, and 1.43% lanthanum oxide. As a result of the trial production of glass beads using waste fluorescent lamp glass, it was judged that the production yield and quality were excellent, so that waste fluorescent lamp glass could be used as a raw material for glass beads. The soda roasted waste phosphor was leached in water and thereby the aqueous solution was blown with CO₂ to drop the pH to about 7, Then, Al, Si and residual N₂CO₃ were dissolved, and NaAlCO₃(OH)₂ and SiO₂ were precipitated in the aqueous solution. In the solvent extraction of cyanex272-hydrochloric acid, cyanex272-sulfuric acid, D2EHPA-hydrochloric acid, D2EHPA-sulfuric acid, Ionquest290-hydrochloric acid, Ionquest290-sulfuric acid, p507-hydrochloric acid using xylene as a diluent, the extraction yield of Y, Eu, Ce, La, and Tb are close to 100%. However, in this conditions, the difference in extraction yield for each element, that is, selectivity is 16% or less.

• Journal of the Korean Vacuum Society
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• v.17 no.6
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• pp.481-486
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• 2008

The different degrees of blackening were observed at the inner surface of borosilicate, soda-lime, and aluminosilicate glass tubes having different sodium (Na) contents. The sodium contents ($Na_2O$) within the borosilicate, soda-lime, and aluminosilicate glass tubes were found to be 4%, 14%, and 0.06%, respectively. The degree of blackening was shown to increase as the sodium content within the glass of the fluorescent lamp containing Ne+Ar+Hg gas mixture. Higher degree of blackening was observed from the inner surface of the glass tube coated with $Y_2O_3$. The blackening was found to be originated from the amalgam of $NaHg_2$ generated by the chemical reaction between the mercury ions within the discharge gas and sodium within the glass tube during operation.

• Horticultural Science & Technology
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• v.35 no.2
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• pp.178-187
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• 2017

The aim of this study was to investigate the effect of different light sources on the levels of glucosinolates (GSLs) in rocket salad (Eruca sativa L.). The light sources used in the study were: natural light (Control-1 or 2), red light-emitting diodes(LEDs), blue LEDs, mixed red and blue LEDs (R+B LEDs), white LEDs, fluorescent lamps (FL), and fluorescent lamps plus UV-C (FL+UV-C). Two separate experiments were conducted [Experiment I: Control-1, Red LED, Blue LED, Mix (R+B) LED and Experiment II: Control-2, White LED, FL, FL+UV-C] because of the limited number of growth chambers in our laboratory. The rate of increase in the length of rocket salad leaves was the highest under red LEDs and, FL confirming that red LED and, FL affect the growth of rocket salad. We separated and identified seven types of GSLs from the rocket salad:glucoraphanin, diglucothiobeinin, glucoerucin, glucobrassicin, dimeric 4-mercaptobutyl GSL, 4-methoxyglucobrassicin, and gluconasturtiin. The highest total GSL contents in Eexperiment I was found in plants grown under in red LEDs ($4.30{\mu}mol{\cdot}g^{-1}\;dry$ weight, DW), and the lowest under blue LEDs ($0.17{\mu}mol{\cdot}g^{-1}\;DW$). The highest total GSL contents in Experiment II was found in plants grown under FL ($13.45{\mu}mol{\cdot}g^{-1}\;DW$), and the lowest in FL+UV-C ($0.39{\mu}mol{\cdot}g^{-1}\;DW$). Especially in Experiment II, the content of dimeric 4-mercaptobutyl, which has a strong aroma and spicy flavor in rocket salad, was higher under FL and white LEDs than in Control-2, increasing by approximately 14.9 and 3.2-fold respectively. Therefore, light sources such as red LEDs, white LEDs and FL affected the accumulation of GSLs in rocket salad.

• The Journal of the Korea Contents Association
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• v.9 no.8
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• pp.248-254
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• 2009

The aim of this study is to optimize the light source combination which can maximize the capability of the illuminance and color temperature of circadian lighting apparatus. To achieve this goal, the circadian lighting apparatus was consisted of two different types of fluorescent lamps having different color temperature of 2000K and 8000K, respectively, and the capability of the illuminance and color temperature of circadian lighting apparatus was evaluated by optical simulation as the number of the respective lamps were varied. Considering the Kruithof's curve and exceptional cases, the ranges of illuminance and color temperature for the living activities were reclassified in 4 groups - gathering, studying, relaxing and sleeping - so that the target range of illuminance and color temperature of lighting apparatus was settled. As a result, in the case of adopting two fixtures in which four 2000K lamps and five 8000K lamps were consisted, respectively to one fixture, the highest illuminance was expected at 4000K and over 500lx of illuminance was calculated between 3000K and 6000K. Through the optimized combination of light sources, the range of illuminance and color temperature were calculated as $44{\sim}750lx$ and $2500{\sim}6500K$, respectively.

• Journal of Applied Reliability
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• v.14 no.3
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• pp.203-207
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• 2014

Electrodeless lamp is famous for its long life. But its reliability is dependent not only on electrodes but also on materials and structures. To evaluate end product's reliability, we studied high temperature durability by $60^{\circ}C$, $75^{\circ}C$ and $90^{\circ}C$ temperature tests, and predicted failure times by an exponential model through regression analysis. However, the test showed that temperature does not affect degradation of electrodeless lamps. Their luminous outputs degrade during the early time of the test (till 250 hours) and then converge to a saturation points. Also, '410nm ~ 530nm' spectrum degrades more than other spectra.

• Journal of the Korean Home Economics Association
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• v.35 no.4
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• pp.149-158
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• 1997

The purpose of this study is to investigate the actual conditions of illumination circumstances in living rooms and the evaluation of residents about those. The respondents of this study were residents of 236 detached houses and 163 apartment houses in Taegu city, The results are as follows: (1) Fluorescent lamps are usded in living rooms by half and plural lighting fixtures are generally used; ceiling light and chandelier. While direct light system is generally used and core type is the most frequent in living rooms. (2) The average used illumination level is 59.7 1x while the possession illumination level is 84.9 1x by investigating of illumination circumstances. (3) Over half of residents are satisfied with illumination circumstances in their own houses. While they wish to improve the lighting fixtures lightness and the kind of light soure in order. And the evaluation of residents are medial level.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.107-109
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• 2007

LED is expected as an environmentally friendly light source with its good reliability and long lifetime. A few ten mW white LED can substitute for the indicator light source, and it is required to study several watt multi-chip semiconductor light sources in order to replace the light sources for general illumination such as incandescent lights and fluorescent lamps. Since the optical technology used for several mW white LED light source uses only 30% to 50% of the light, it is required to develop the design technology of optical system and lens to improve the efficiency more than 80% for insuring the high power of white LED. In this paper, we designed and fabricated new structure reflector to increase the efficiency.

• Proceedings of the KIEE Conference
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• 2006.10b
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• pp.221-223
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• 2006

최근 수요가 급증한 36W 단일 캡 형광램프의 과열로 인하여 화재의 위험성이 대두되고 있다. 단일 캡 형광램프는 이중 캡에 형광램프에 비하여 길이가 작아 다루기가 쉽고, 관 지름이 작아 고효율의 형광램프로 인식되고 있다. 그러나 한쪽방향에 전극을 가지고 있어 열 분산 면에서 이중 캡에 비하여 열 축적 가능성이 크고, 수명말기에 전극필라멘트가 열에 의해 소실되었을 경우 관경이 작아 필라멘트 지지 스템(stem)의 길이가 가까워 고속스위칭의 전자식안정기를 적용한 시스템에서 완전히 개방되지 않고 임피던스의 상승만을 가져올 수 있다. 이로 인하여 캡의 열화에 의한 분리가 일어나고, 화재의 원인이 될 수 있다. 이러한 현상은 형광등의 수명 말기에 발생하는데 본 논문에서는 형광등의 수명말기 현상을 모델링하여 단일 캡 36W 형광램프의 수명 말기에 발생하는 과열에 관한 시험방법에 대하여 시험 연구 하였다.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.403-405
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• 2004

This paper describes an implementation of Home network Control Protocol(HnCP) and it's application to an Intelligent lighting system. The HnCP was announced by korea PLC forum in June 2003 to provide a network protocol for PLC based home appliances. The HnCP master and HnCP slaves were implemented using XPLC30 which is an SOC with ARM9 core. The efficacy of the developed HnCP network modules were shown by applying them to a intelligent lighting system composed of dimmable fluorescent lamps. An extended message set was proposed for the intelligent lighting system and we proposed some directions for the future development of HnCP.