• 한국염색가공학회지
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• 제13권6호
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• pp.1-1
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• 2001

In this study, wool, silk and cotton fabrics were dyed with natural dyes derived from Ginkgo biloba bark using various mordants, and their dyeabilities were discussed. Additionally the fastness to washing, perspiration, light, rubbing, and drycleaning were investigated. And the effects of bacteria reduction and UV-B protection rate were also checked. The optimum dyeing condition of the colorants extracted from the Ginkgo biloba bark was three repeated dyeing at 95℃ for 1 hr. by using post mordanting. Mordanting improved the fastness to washing, Perspiration and drycleaning, but the fastness to light and rubbing were not increased. The bacteria reduction rate of the wool fabric increased drastically by dyeing with extract of Ginkgo biloba bark and its effect maintained after repeated washing and drycleaning. UV-B protection rate of the natural fibers increased by dyeing with extract of Ginkgo biloba bark and the dyed wool fabric was the best of the three fabrics.

• 한국연소학회지
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• 제14권4호
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• pp.17-24
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• 2009

Reburning is one of the most useful technologies for reducing nitric oxide in economically and technically. The reburning process was demonstrated as an effective NOx reduction method through injection of a secondary hydrocarbon fuel. An experimental study has been conducted to evaluate the effect of biomass reburning on NOx and CO formation in a light oil flamed combustion furnace. Reburning tests on NOx reduction of air-carried rice husk powder as the reburn fuel and light oil as the main fuel were performed in flames stabilized by a co-flow swirl and fuel staged burner, which was mounted at the front of the furnace. The results included flue gas emissions and temperature distribution in the furnace for several kinds of experimental conditions. It was observed clearly that NOx concentrations in the exhaust have considerably decreased due to effect of biomass reburning. The maximum NOx reduction rate was 42% when the reburn fuel fraction was 0.18. The CO emissions were kept under 42 ppmv in all experimental tests. And this paper makes clear that in order to decrease NOx concentration in the exhaust when the biomass reburning system is adapted, the control of some factors such as reburn fuel fraction and reburn zone fraction is very important.

• 조명전기설비학회논문지
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• 제30권3호
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• pp.9-20
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• 2016

This study compared the effect of green light consequent on maximum brightness 85 lx and intial brightness 15 lx, and its accompanying psychological, physiological response. 1) As a result of psychology(general stress evaluation, Symptom Checklist-90-Revision) evaluation, all stress evaluation items mostly showed a decrease, and they are comparatively positively evaluated in minimum brightness 15 lx comparing to maximum brightness 85 lx. 2) Physiological (Heart Rate Variability) evaluation result was included in stable range in all cardiovascular system variables after light stimulus in time of comparison with the standard range; in addition, the Heart Rate Variability evaluation result was found to be stable in all cardiovascular system variables except Low Frequency in minimum brightness 15 lx comparing to maximum brightness 85 lx. 3) Green light was found not to appear as a stimulating factor in the human body in time of space projection, being found to be effective in stability of mind and body, and reduction in stress. Thus, it was found that green light functioned as an emotional, relaxing tranquilizer by working on the sympathetic nervous system.

• 한국의상디자인학회지
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• 제2권1호
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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.

• 예술인문사회 융합 멀티미디어 논문지
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• 제5권5호
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• pp.461-470
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• 2015

최근 건물부분에서의 조명에너지 증가로 인한 이를 해결하고자 하는 연구와 기술기발의 수요는 증가하고 있으며, 광선반은 이러한 문제에 대한 해결책 중 하나로 그 유효성을 인정받아서 많은 연구가 이루어지고 있다. 그러나 광선반에 관련한 연구는 단순 광선반의 변인에 초점에 맞추어져 광선반 설계시 적절한 설계기초자료가 될 수 없다. 이에 본 연구는 실내공간의 반사율에 따른 광선반 성능평가로 광선반 설계시 기초자료 구축을 목적으로 한다. 본 연구는 실스케일의 테스트베드를 통하여 실내조도 분포 및 조명에너지 사용량을 산출하여 성능평가를 진행하였으며, 이에 대한 결론은 다음과 같다. 1) 실내공간의 천장과 벽의 반사율 감소는 동지, 하지, 중간기시 모두 평균조도를 감소시켜 조명에너지 저감에 부적합하며, 실내공간의 반사율에 따른 균제도는 동지, 하지, 중간기시 상이한 경향을 보여 광선반 설계시 고려해야 할 요소로 판단된다. 2) 조명제어에 따른 전력사용량을 도출한 결과 실내 공간의 높은 반사율은 에너지 저감에 적합할 수 있으나 실내 공간의 반사율에 관련한 연구 및 적용의 효용성에 입각하여 천정 80%이상, 벽면 75%의 반사율이 적정할 것으로 도출된다. 본 연구는 실내 환경의 변인을 고려한 광선반 연구로 의미를 부여할 수 있으며, 향후 보다 다각적인 변인을 기반한 연구는 지속적으로 필요할 것으로 판단된다.

• 한국산림과학회지
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• 제97권5호
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• pp.508-515
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• 2008

Sycamore (Platanus occidentalis L.) seedlings were grown under low light intensity and ozone treatments to investigate the role of the light environment in their response to chronic ozone stress. One-year-old seedlings of Platanus occidentalis L. were grown in pots for 3 weeks under low light (OL, $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and high light (OH, $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) irradiance in combination with 150 ppb of ozone fumigation. After three weeks of ozone and light treatment, seedlings were placed in ozone free clean chamber for 3 weeks for recovery from ozone stress with same light conditions to compare recovery capacity. Ozone fumigation determined an impairment of the photosynthetic process. Reduction of leaf dry weight (14%) and shoo/root ratio (17%) were observed in OH treatment. OL treatment also showed severe reductions in leaf dry weight and shoot/root ratio by 48% and 36% comparing to control, respectively. At the recovery phase, OH-treated plants recovered their biomass, whereas OL-treated plant showed reduction in leaf dry weight (52%) and shoot/root ratio (49%). OH-treated plants reached similar relative growth rate (RGR) comparing to control, whereas OL-treated plants showed lower RGR in stem height. However, there were no significant differences in response to those treatments in stem diameter RGR at the recovery phase. Ozone treatment produced significant reduction of net photosynthesis in both high and low light treatments. Carboxylation efficiency and apparent quantum yield in OL-treated plants showed significant reductions rate to 10% and 45%, respectively. At the recovery stage, ozone exposed seedlings under high light had similar photosynthetic capacity comparing to control plants. Antioxidant enzymes activities such as superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR) were increased in ozone fumigated plants only under low light. The present work shows that the physiological changes occur in photosynthesis-related parameters and growth due to ozone and low light stress. Thus, low light seems to enhance the detrimental effects of ozone on growth, photosynthesis, and antioxidant enzyme responses.

• 임산에너지
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• 제19권1호
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• pp.7-12
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• 2000

본 실험은 광도가 곰솔(Pinus thunbergii Parl.) 유묘의 생장과 물질생산에 어떠한 영향을 미치는 가를 알고자 자연전광이 100, 50, 30, 10% 및 2%로 조절된 야외포지에서 1997년 5월부터 1998년 10월까지 실시되었다. 곰솔의 수고생장 및 근원경생장은 1,2차년을 통하여 자연전광에서 가장 높악으며, 50%에서의 수고생장은 1,2차년도 각각 대조구의 96.4, 88.9%로, 근원경생장은 각각 94.1 77.6%로 조상되엇다, 30%이하로 상대광도가 낮아질수록 수고 및 근원경생장이 급격히 감소 되었으며, 근원경생장의 감소율이 수고생장의 감소율보다 높게 나타났다. 2차년도의 2%에서는 시험 유묘 모두가 고사하였다. 물질생산량도 광도가 낮아짐에 따라 감소되었으며, 1, 2차년도 모두 뿌리의 감소율이 잎, 줄기보다 높았고, 1차년도에는 줄기의 감소율이, 2차년도에는 잎이 감소율이 가장 낮았다. T/R율은 1차년도에는 50%에서,3.55, 2차년도에는 10%에서 4.88로 가장 높았다.

• 한국염색가공학회지
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• 제27권1호
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• pp.96-104
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• 2015

This study examined the pretreatment effect, appropriate dyeing conditions, color fastness and functionality of cotton fabrics dyed with Zizania latifolia Turcz. Dye uptake was substantially increased by pretreatment and chitosan pretreatment was much more effective than tannic acid pretreatment. Optimal dyeing conditions were colorant concentration of 100%, dyeing temperature of $100^{\circ}C$, dyeing time of 80 minutes and dyebath pH of 5.5. Color fastness of chitosan pretreatment and dyed cotton to washing, rubbing, perspiration and light was 4, 5, 3-4(acidic), 3(alkaline) and 3 respectively. Color fastness of tannic acid pretreatment and dyed cotton to washing, rubbing, perspiration and light was 4, 5, 3-4(acidic), 4-5(alkaline) and 4 respectively. Deodorization rates of ammonia(NH3) were 99.9% in both cases. UV protection rate were 98.3% of UV-A and 98.5% of UV-B in case of chitosan pretreatment. UV protection rate were 98.2% of UV-A and 98.5% of UV-B in case of tannic acid pretreatment. UV protection factor(UPF) was 50+ in both cases. Reduction rate of Staphyloccus aureus were 99.9% in both cases. Therefore Zizania latifolia Turcz. could be used a new functional colorant.

• 융합정보논문지
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• 제7권3호
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• pp.97-103
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• 2017

본 논문에서는 가시광 통신 시스템에서 디밍 제어를 위한 Zero Reduction Code (ZRC)의 다양한 부호화율 및 채널 조건에서 성능 분석을 진행함으로써, ZRC 부호의 특성 일반화 고찰을 목표로 한다. 이를 위해 무선 광 통신 시스템의 LOS (Line-Of-Sight)와 NLOS (Non-LOS) 채널의 특성을 설명하고, (5, 4), (6, 5), (7, 6)ZRC 부호화율에서 디밍 과 BER (Bit Error Rate)측면에서 모의실험을 통해 성능 분석을 진행하였다. 모의실험 결과, 3가지 타입의 부호화율에서 디밍 성능은 비슷하지만, NLOS 채널 환경에서 RMS (Root Mean Square) 지연 확산 값이 증가 될수록 상대적으로 높은 부호화율의 ZRC코드가 좋은 BER성능을 달성하는 것을 확인 하였다. 따라서 향후 가시광 통신시스템에서 ZRC를 이용한 디밍 제어 기술을 설계할 때 본 연구에서 분석한 결과를 통해 채널 상태에 따른 부호화율을 결정하는데 도움이 될 것으로 예상된다.

• Current Optics and Photonics
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• 제2권5호
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• pp.468-473
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• 2018

We investigate the temperature dependence of efficiency droop in InGaN/GaN multiple-quantum-well (MQW) blue light-emitting diodes (LEDs) in the temperature range from 20 to $80^{\circ}C$. When the external quantum efficiency (EQE) and the wall-plug efficiency (WPE) of the LED sample were measured as injection current and temperature varied, the droop of EQE and WPE was found to be reduced with increasing temperature. As the temperature increased from 20 to $80^{\circ}C$, the droop ratio of EQE was decreased from 16% to 14%. This reduction in efficiency droop with temperature can be interpreted by a temperature-dependent carrier distribution in the MQWs. When the carrier distribution and radiative recombination rate in MQWs were simulated and compared for different temperatures, the carrier distribution was found to become increasingly homogeneous as the temperature increased, which is believed to partly contribute to the reduction in efficiency droop with increasing temperature.