• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.224-224
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• 2003

광통신을 위한 구성 요소는 빛을 발생시키는 발광소자, 빛을 검출하는 수광소자 그리고 광신호를 처리하는 광신호처리 소자로 구성된다. 이때 각 소자간 광전송과 광소자에 의한 광 신호 처리 과정에서 광전송 손실이 심각하게 일어나 광정보를 상실하게 되므로 각 요소별로 광신호 증폭이 반드시 필요하다. 뿐만 아니라 완전 광화에 의한 초고속/대용량 광통신망의 구축에는 저가이며, 광집적화가 가능한 광도파로형 광증폭기가 요구되고 있다. 짧은 거리에 높은 증폭 효율을 얻기 위한 광도파로형 광증폭기를 구현하기 위해서는 광통신 파장대인 1.55$\mu\textrm{m}$ 대역의 증폭이 가능한 Er 이온을 고농도로 도핑 할 필요가 있다. 그러나 Er 이온을 단순히 고농도로 첨가하면 Er-Er 간 뭉침 현상에 의해 더 이상의 증폭이 어렵게 된다. 본 연구에서는 이러한 문제를 해결하면서 스핀 코팅이 가능하여 저가 공정이 가능한 유/무기 졸-겔 재료 내에 Er 이온을 제어된 방법으로 첨가하고 그 결합 환경을 FT-IR 및 $^{17}$ O-NMR로 분석하였다. 유/무기 졸겔 재료 제조를 위하여 먼저 MPTS(MethAcryoxyPropylTrimethoxySilane)를 부분 가수분해한 후 ZrOCl$_2$.8$_2$O (Zirconyl Chloride Octahydrate) 와 ErCl$_3$. 6$H_2O$ (Erbium(III) Chloride Hexahydrate)를 순차적으로 결합시키고, Zr/MPTS 및 Zr/Er의 첨가비에 따른 발광 특성을 PL(photoluminescence) 스팩트럼으로 분석하여 Er 이온의 주위 결합 환경이 PL에 미치는 영향을 조사하였다. 또한 Si 기판에 코팅한 Er이 도핑된 유/무기 하이브리드 졸-겔 코팅막의 굴절율 등 광도파로 재료로서의 특성도 프리즘 커플러 등을 이용하여 조사하였다.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.284-289
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• 2010

Spectral irradiance of greenhouse covering films that three resins (red, blue, red plus blue) were added to get higher utilization efficiency of sunlight were compared to the normal film in this study. Growth and yield of tomato and pepper grown under the films were also investigated. Transmittance of PAR (photosynthetically active radiation, 400~700 nm) and sunlight (300~1,100 nm) of red or blue resin-added films increased by 5 to 6% and 0.5 to 1.0%, respectively. As compared to the normal film, fruit yield and soluble solid content of tomato and pepper grown under red plus blue resin-added film increased by 15 to 20% and by $0.5^{\circ}Bx$.

• Journal of Korea Soil Environment Society
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• v.2 no.3
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• pp.39-47
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• 1997

Geochemical study was carried out to find out the distribution of metals and cyanide in soil in the vicinity of the abandoned Daduck mine and the reason for acid mine drainage occurrence in the tailings impoundment. Chemical analysis showed that content of As in soil around tailings exceeded 15mg/kg, Korean standard of soil contamination in the farm land. That means the contamination of soil by As is due to input of tailings. According to total decomposition of tailings, As, Cd, Cu, Pb, Zn and S were highly concentrated in tailings. However the water in tailings impoundment was changed to acidic and contaminated by metals and sulfate because the tailings in the top of the tailings impoundment had been oxidized. Acid mine drainage contaminated the water course in the vicinity of the paddy soils. The proper measures are required to prevent contamination of the soil and water in the vicinity of the Daduck mine.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1997.05a
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• pp.53-58
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• 1997

시설내 방적처리별 광환경, 개선 효과는 수적율이 환기나 송풍 단독으로 처리한 경우보다 2.6-5.8% 가량 낮은 2.7%를 보여 투광율이 송풍, 환기 단독 처리구보다 2.7-4.9% 가량 높아 67.4%를 보인 송풍+환기개선처리에서 가장 우수하였고 하우스 공간에서의 정식후 6일간 적산최저기온은 무처리에 비하여 4.6$^{\circ}C$가 낮았으나 작물이 정식된 터널에서는 0.8$^{\circ}C$ 정도 낮았다. 참외의 생육은 환경이 방적효과로 광환경이 우수한 송풍+환기개선처리에서 두 처리보다 엽수가 3-5매 가량 많고 착과율도 4-8% 정도 높아 전체적인 수량이 3,630kg/10a로 무처리에 비하여 43%나 증수되었다.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.105-109
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• 2020

This study was conducted to the improvement of solar light-based artificial light supply system and effect of lettuce cultivation. The artificial light supply system was consisted of units such as light source, power, system measurement and controller. The light source supply was composed of a solar transmitter and an LED lamp. The power supply consisted of an leakage breaker, SMPS, LED controller and relay. The solar transmitter was made of a quartz optical fiber with optimal light transmission. Artificial light used white lamp among LEDs. System measurement and control consisted of touch screen, Zigbee communication module and light quantity sensor. The results of test confirmed that the LED light is automatically activated when the intensity measured by the light intensity sensor is 200 μmolm^-2s^-1 or less. Moreover, the leaf length, root length, chlorophyll content and root fresh weight of optical fiber treatment was hight than LED lamp treatment. Therefore, it can be inferred that the energy-saving solar light collector device can be effective in the indoor lettuce production. However, the use of LED lamp is also recommended to assure the availability of sufficient sunlight in cloudy and rainy days.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.2
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• pp.77-84
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• 2023

As the installation of solar panel accelerates, so does the number of solar panels reaching their end-of-life (EOL). However, the EOL solar panels is becoming a concern, as they contain potentially hazardous materials and are not easily recycled. Coping strategies such as effective collection, disposal, and recycling methods will be important to manage the growing number of EOL solar panels in the coming years.Therefore, many studies have focused on the development of EOL solar panel recycling technology. One recycling technology for EOL solar panels applicable to the construction field is the application of extracted tempered glass from EOL solar panels as construction materials. This study summarized the EOL solar panel disassembly technology and evaluated the mechanical properties of mortar using extracted tempered glass as fine aggregate. The results showed that when tempered glass was used as a fine aggregate in mortar, the compressive strength, flexural strength, and macro pores in the 1-3 ㎛ with 200-300 ㎛ range were affected, regardless of the disassembly technology of EOL solar panels. Especially, we found that the mechanical performance of mortar using chemically treated tempered glass was noticeably decreased due to changes in the chemical composition of the extracted tempered glass resulting from the removal of K₂O and CuO due to chemical reactions. Meanwhile, it was found that when fly ash was used as a binder, the reduction of mechanical performance could be alleviated.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.322-327
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• 2013

This research was conducted to elucidate the appropriate light environment right after grafting to produce vigorous cherry tomato seedlings. Tomato plants were grafted and then treated in 4 different ways: to keep in the natural light (Non), to cover the grafted stem part with aluminum foil to make only that part dark (Part), to put the grafted seedlings in the acclimation room for two (Day-2) or four days (Day-4) to make the whole seedlings in the dark condition. Tube grafting method was used for grafting, in which silicon tube of 1.5mm in diameter was used. The survival rate was the maximum in the treatment Day-2. The SPAD value, seedling quality and yield of $1^{st}$ and $2^{nd}$ cluster were the best in the treatment Part. The treatment Part needs cost more than other treatments but is more economic thanks to higher yield. Therefore it was concluded to be economically feasible to make the grafted stem part dark right after grafting in case of cherry tomato.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.284-293
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• 2000

For the artificial removal of air pollutants such as pesticides, environmental toxicants, and pathogenic microorganisms in the greenhouse or the living environment, the accelerated photodegradation and the biocidal effects of some photosensitizers (PS)/photocatalysts (PC) were tested under the sunlight and/or artificial light. The selected photosensitizers/photocatalysts included the semiconductors (PC-1 and PC-2), the oxidizers (PC-3, PC-4, PC-5 and PC-6), the aromatic ketone (PS-7) and the aromatic amine (PS-8). In the case of dichlorvos, all the photocatalysts selected showed more accelerated photodegradation than the control without photocatalysts under both the sunlight and artificial light. Whereas, only the photocatalyst PC-1 accelerated the degradation of methyl tert-butyl ether about 17 times more than the control under both the sunlight and artificial light. Procymidone was much more degraded by the photosensitizer PS-8 and the two photocatalysts (PC-1, PC-6) than by PS-7. In the preliminary experiments to diminish the population of the microorganisms in the air, the photocatalyst PC-1 added to the suspensions of Pseudomonas putida, Phytophthora capsici, and Salmonella typhimurium obviously inhibited the microbial growth under the artificial light. The photocatalyst PC-1 showed a bactericidal activity against Salmonella typhimurium spread on the nutrient broth agar medium. These results suggest that the photosensitizers/photocatalysis under the light can remove some air pollutants and hence they can be used to reduce the exposure of the workers in the horticultural facilities and/or the public in the environment to the harmful pollutants.

• Journal of Life Science
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• v.28 no.11
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• pp.1321-1331
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• 2018

The aim of this study was to separate the photosensitizer that induces apoptosis of U937 and SK-HEP-1 cells from Nostoc commune. Dried N. commune was extracted with $CH_2Cl_2/MeOH$ (1:1) to separate the photosensitizer using various chromatographic techniques. The isolated compound was identified as pheophytin a ($C_{55}H_{74}N_4O_5$) with a molecular weight of 870. Its photodynamic activities were assessed under different irradiation conditions (light and non-light) at the same concentration range of $1.15-23.0{\mu}M$. The apoptosis inducing activity in U937 or SK-HEP-1 cells appeared only in the light. The mechanisms underlying the pheophytin a-mediated photodynamic inhibition of cancer cells were further investigated by examining cell morphology changes, cytotoxicity, caspase-3/7 activity, fluorescence staining, flow cytometry analysis, and DNA fragmentation in these two cell lines. The positive control and the light irradiation group showed typical apoptotic responses, including morphological changes, cytotoxicity, caspase activity, nucleus shrinkage owing to chromatin condensation, DNA laddering, and the presence of apoptotic bodies. Cytotoxicity markedly increased in a dose-dependent manner after a 12 hr exposure. Caspase-3/7 activity was higher in U937 cells than in SK-HEP-1 cells. Apoptosis induction therefore appeared to be both concentration- and light-dependent. In conclusion, pheophytin a, isolated from the blue green alga N. commune, had a photodynamic apoptosis-inducing effect on U937 and SK-HEP-1 cells. The findings reported here can be used as basic data for the development of next-generation photosensitizers from N. commune.

• Electric Engineers Magazine
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• s.311
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• pp.30-31
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• 2008

이번호에서는 건축물에 설치한 태양광발전시스템에 대한 뇌보호에 대하여 설명하기로 한다. 우리나라는 국토가 좁아 국토를 낭비하면서 무한정으로 지상에 태양광발전설비를 시설할 수는 없는 실정이며, 전세계적으로 전체에너지의 약 75%는 도시에서 소비하고 그 중 40%는 건물에서 사용되고 있으며 건물을 건설하고 이용하는 동안 에너지의 약 50%가 소비되고 오염물질의 34%가 발생한다고 한다. 따라서 건물을 건설시 건물일체형인 BIPV(Building lntegrated Photovoltaic)시스템을 적용시킴으로서 토지매입비와 또 다른 환경파괴를 방지하는 것은 물론 전 국토와 도시를 효율적으로 이용할 수 있는 것이다.