• Environmental Engineering Research
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• 제25권4호
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• pp.529-535
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• 2020

The present study investigated the photodegradation of synthetic organic dye; violet-3B, without and with the addition of C-N-codoped TiO₂ catalyst using a visible halogen-lamp as a light source. The catalyst was synthesized by using a peroxo sol-gel method with free-organic solvent. The effects of initial dye concentration, catalyst dosage, and pH solution on the photodegradation of violet-3B were examined. The efficiency of the photodegradation process for violet-3B dye was higher at neutral to less acidic pH. The kinetics reaction rate of photodegradation of violet-3B dye with the addition of C-N-codoped TiO₂ followed pseudo-first order kinetics represented by the Langmuir-Hinshelwood model, and increasing the initial concentration of dyes decreased rate constants of photodegradation. Photodegradation of 5 mg L^-1 violet-3B dye achieved 96% color removal within 240 min of irradiation in the presence of C-N-codoped TiO₂ catalyst, and approximately 44% TOC was removed as a result of the mineralization.

• 조명전기설비학회논문지
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• 제24권12호
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• pp.25-32
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• 2010

Compared to general lighting method, the lighting system that uses optic fiber can provide only the visible light of good quality to subject by eliminating ultraviolet ray and infrared ray. Thanks to this merit, it is possible to prevent the hard phenomenon of subject caused by ultraviolet ray and infrared ray and to provide the agreeable light environment. This study developed indoors illumination system of high color rendering on the basis of plastic optic fiber with excellent optical property and processing to substitute halogen lamp which has been used for excellent color rendering in spite of low efficiency and short life. Producing pilot product of the designed illumination system and evaluating the property of electric and optical property, ultraviolet ray radiation quantity and temperature property, this study verified the excellence of suggested lighting system of plastic optic fiber.

• 한국안전학회지
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• 제31권2호
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• pp.18-25
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• 2016

The incandescent lamp is an electric light fixture with a tungsten filament heated to a high temperature, by passing an electric current through it, until it glows with visible light. The hot filament is protected from oxidation with a glass bulb that is filled with inert gas. The incandescent lamp has fire risk when combustible materials are close to its glass bulb. Because its lamp has the property which converts 90~95 percents of the electric power to heat energy. 2015 national fire statistics show that fires caused by lighting fixtures were 652 cases, and incandescent lamps(44 cases) and halogen lamps(53 cases) accounted for 15 percents in those of high heating light fixtures. Since incandescent lamp fires account for about 45 percents in the high heating light fixture, we could not overlook the fire risks by the incandescent lamp. Although many studies related with those have been conducted, incandescent lamp fires are continuously occurred. This study was carried out to study the fire risk of ignition of wood due to radiant heat of incandescent lamp. Radiant heat flux of the incandescent lamp was predicted by applying point source model, and critical distance for ignition of wood was calculated by applying integral model. The results from this study could applied to fire prevention activities related to light bulb, and it could be used in fire cause investigations related to radiant heat of incandescent lamp.

• 조명전기설비학회논문지
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• 제18권5호
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• pp.48-53
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• 2004

광원의 분광복사조도를 250∼1600[nm] 파장 영역에서 정확하게 측정하기 위한 분광복사조도 측정 장치를 개발하였다. 분광복사조도 측정 장치는 광원 장치, 광학계, 분광장치, 광검출장치, 신호 처리 장치 등으로 이루어져 있다. 광검출 장치는 PMT, Si, InGaAs 및 IR enhanced InGaAs 광검출기를 이용함으로써 자외선, 가시광선, 적외선을 포함하는 넓은 파장 범위에서 광원의 스펙트럼을 측정할 수 있다. 개발된 측정 장치를 이용하여 1[kW] quartz-halogen 텅스텐 전구의 분광복사조도를 측정하여 비교하였는데, 측정 결과와 NIST에서 측정된 결과와는 차이는 450∼700[nm] 파장 영역에서 3[%] 이하이며, 700∼1600[m] 파장영역에서는 3.5[%] 이하이며, 250∼400[nm] 파장영역에서는 5[%] 이하로 측정되었다.

• 천문학논총
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• 제28권3호
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• pp.75-82
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• 2013

An optical grism for education is fabricated and tested. It is composed of a transmission grating as dispersion element and a prism as diffraction angle compensation device. The transmission grating is Edmundoptics #49-584(spatial frequency 600 lines/mm, dimension $50mm{\times}50mm$). The prism is the fused silica type with angles ($41.3^{\circ}$, $-48.7^{\circ}$, $-90^{\circ}$). The grism device is fabricated by bonding the transmission grating and the prism with an optical adhesive. The zig for assembling the grism, telescope and camera is composed of an aluminum tube, an aluminum disk ring and a T-ring camera adaptor. The fabricated optical grism spectrograph is tested in laboratory using Halogen lamp and Neon lamp with DSLR camera. And the grism assembled with reflector telescope is tested in a field using stellar light. The results show good agreements with design parameters. The wavelength coverage range of the grism is 250 nm at the un-deviated wavelength of 506 nm. The wavelength resolution is 0.11 nm/pixel.

• JSTS:Journal of Semiconductor Technology and Science
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• 제6권2호
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• pp.119-123
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• 2006

This work presents the fabrication and characteristics of $Bi_2O_3/Si$ heterojunction prepared by rapid thermal oxidation technique without any postdeposition annealing condition. The bismuth trioxide film was deposited onto monocrystalline Si and glass substrates by rapid thermal oxidation of bismuth film with aid of halogen lamp at $500^{\circ}C/\;45$ s in static air. The structural, optical and electrical properties of $Bi_2O_3$ film were investigated and compared with other published results. The structural investigation showed that the grown films are polycrystalline and multiphase (${\alpha}-Bi_2O_3$ and ${\beta}-Bi_2O_3$). Optical properties revealed that these films having direct optical band gap of 2.55 eV at 300 K with high transparency in visible and NIR regions. Dark and illuminated I-V, CV, and spectral responsivity of $Bi_2O_3/Si$ heterojunction were investigated and discussed.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.408-408
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• 2014

Graphene has received attention with its high electron mobility and visual transparency as a promising material for optoelectronic and photonic applications. Combination of graphene and conducting nanostructures i.e. plasmonic structures has recently been researched for enhancing light-matter interaction and overcoming diffraction limit of light. Here we show enhanced photodetection of incoherent visible light with graphene-mediated plasmonics. Gold nanoparticles fabricated by focused ion beam was used as an active element of photodetection and graphene was utilized as an interfacing material between nanostructures and electrodes. Hot electrons generated upon plasmon decay within nanoparticles pass over the potential barrier between nanostructure and graphene and give rise to a photocurrent with built-in electric field. We report 76.7% enhancement of photocurrent under resonant irradiation of fiber-coupled halogen lamp compared to the case without light illumination. We showed wavelength-dependent current response arisen from plasmonic nanostructure, providing a good agreement with theoretical calculation.

• Journal of Periodontal and Implant Science
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• 제43권2호
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• pp.72-78
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• 2013

Purpose: The purpose of this study was to compare the phototoxic effects of blue light exposure on periodontal pathogens in both planktonic and biofilm cultures. Methods: Strains of Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis, in planktonic or biofilm states, were exposed to visible light at wavelengths of 400.520 nm. A quartz-tungsten-halogen lamp at a power density of $500mW/cm^2$ was used for the light source. Each sample was exposed to 15, 30, 60, 90, or 120 seconds of each bacterial strain in the planktonic or biofilm state. Confocal scanning laser microscopy (CSLM) was used to observe the distribution of live/dead bacterial cells in biofilms. After light exposure, the bacterial killing rates were calculated from colony forming unit (CFU) counts. Results: CLSM images that were obtained from biofilms showed a mixture of dead and live bacterial cells extending to a depth of $30-45{\mu}m$. Obvious differences in the live-to-dead bacterial cell ratio were found in P. gingivalis biofilm according to light exposure time. In the planktonic state, almost all bacteria were killed with 60 seconds of light exposure to F. nucleatum (99.1%) and with 15 seconds to P. gingivalis (100%). In the biofilm state, however, only the CFU of P. gingivalis demonstrated a decreasing tendency with increasing light exposure time, and there was a lower efficacy of phototoxicity to P. gingivalis as biofilm than in the planktonic state. Conclusions: Blue light exposure using a dental halogen curing unit is effective in reducing periodontal pathogens in the planktonic state. It is recommended that an adjunctive exogenous photosensitizer be used and that pathogens be exposed to visible light for clinical antimicrobial periodontal therapy.

• 한국축산시설환경학회지
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• 제16권3호
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• pp.227-236
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• 2010

본 시험은 가시광선을 이용한 돈분뇨 액비의 부숙여부를 구명하고, 이를 활용한 측정 장치의 개발을 목적으로 수행하였으며, 그 결과는 다음과 같다.가. 돈분뇨 액비 저장기간이 경과함에 따라 pH는 증가하고 EC는 낮아졌으며, 액비를 폭기처리하므로서 무처리에 비해 pH는 더 증가하고 EC는 더 낮아지는 경향을 나타내었다. 나. 돈분뇨 액비 저장기간이 경과함에 따라 주요 악취물질인 암모니아 ($NH_3$)와 황화수소($H_2S$) 농도가 낮아지는 경향을 나타냈으며, 폭기처리를 하므로서 악취농도가 현저하게 낮아지거나 없어지는 결과를 보였다. 다. 돈분뇨 액비의 종자발아율은 무 및 배추종자 공히 초기부터 6주 경과시까지는 전혀 전혀 발아되지 않았고, 7주가 지나고부터 서서히 서서히 발아율이 높아지는 경향이었으나, 무폭기처리한 액비의 종자발아율은 무 및 배추종자 공히 초기부터 시험종료시까지 전혀 전혀 발아되지 않았다. 라. 원형여지크로마토그래피법에 의한 돈 분뇨 액비 부숙여부 반응을 조사한 결과, 폭기처리한 액비의 경우 초기부터 10주까지는 부식반응을 보이지 않았으나, 10주가 지나고 톱니바퀴 모양이 조금씩 형성되면서 반응을 보이기 시작하였고, 무폭기 처리한 액비는 시험 종료시까지 반응을 보이지 않았다. 마. 돈분뇨 액비의 부숙에는 pH, EC, 종자 발아율, 악취농도 및 원형여지크로마토그래피 반응 등이 관련되는 것으로 나타났다. 바. 색도를 이용한 돈분뇨 액비 부숙도 축정을 위해 소프트웨어와 하드웨어를 개발하였으며, 클러스터링을 이용한 액비부숙도 분석 프로그램을 완성하였다. 사. 돈분뇨 액비 부숙도 측정장치는 텅스텐할로겐, 듀테륨램프, 시료투입구, 석영셀, 분광분석기, 악취측정기, 분석소프트웨어 등으로 구성되었으며, 액비의 부숙여부를 간편하고 신속하게 예측할 수 있었다.