• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2133-2139
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• 2012

A new system using $TiO_2$ (nano-sized, band-gap 3.14 eV)-impregnated spherical ZnS (micro-sized, band-gap 2.73 eV) nano/micro-composites (Ti 0.001, 0.005, 0.01, and 0.05 mol %/ZnS) was developed to enhance the production of hydrogen from methanol/water splitting. The ZnS particles in a spherical morphology with a diameter of about 2-4 mm which can absorb around 455 nm were prepared by hydrothermal method. This material was used as a photocatalyst with loading by nano-sized $TiO_2$ (20-30 nm) for hydrogen production. The evolution of $H_2$ from methanol/water (1:1) photo splitting over the $TiO_2$/ZnS composite in the liquid system was enhanced, compared with that over pure $TiO_2$ and ZnS. In particular, 1.2 mmol of $H_2$ gas was produced after 12 h when 0.005 mol % $TiO_2$/ZnS nano/micro-composite was used. On the basis of cyclic voltammeter (CV) and UV-visible spectrums results, the high photoactivity was attributed to the larger band gap and the lower LUMO in the $TiO_2$/ZnS composite, due to the decreased recombination between the excited electrons and holes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1491-1495
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• 2007

Due to proliferation of Digital cameras and high-speed digital printers, anyone can do easily digital photo shoot and print services, but album manufacture for celebrating the graduation or marriage, and a hundred days needs a lot of capacity of image files and requires high quality, therefore that is working in the photo studio's to the whole responsibility. In this paper, we show all album process to product album manufacture quickly and accurately using high-quality template and variety of libraries, and propose CTS(computerized typesetting system) to build album, which separates a role of photo studio, processing laboratory and printing house and can revolutionize a working process.

• Journal of Adhesion and Interface
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• v.15 no.1
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• pp.22-30
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• 2014

Self-photoinitiating acrylate (SPIA) which can undergo self-initiation under UV irradiation was synthesized by a Michael addition in the presence of a base catalyst. The SPIA polymerizations were investigated by photo-differential scanning calorimeter (photo-DSC) and surface physical properties such as pendulum hardness and pencil hardness. The results showed that the SPIA can cure upon UV irradiation by itself without a photoinitiator. But we found out that both the curing rate and the conversion were too low for the self-curing reaction of SPIA. In order to improve the SPIA curing properties, we introduced the SPIA/cationic hybrid system and observed the effects of the addition of commercial free radical type monomer and photoinitiator on the curing behaviors. SPIA/cationic hybrid system was the best suitable to improve the SPIA curing properties. The kinetic analysis indicated that the cationic monomer and photoinitiator apparently accelerated the cure reaction and rate of the hybrid SPIA system, mostly due to the synergistic effect of cationic monomer and photoinitiator increasing the mobility of active species and the generation of reactive species (free radical, cation) during the photopolymerization process. The physical properties showed that, unlike typical free radical system, the hybrid systems did not show oxygen inhibition effect because of cationic reaction on the coating surface.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4B
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• pp.441-447
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• 2008

Volatile organic compounds (VOCs) emitted from various industrial sources commonly consist of biodegradable chemicals and recalcitrant compounds. Therefore, it is not effective to employ a single method to treat such mixtures. In this study, a novel hybrid system coupled with a ultraviolet (UV) photolysis reactor and a biofilter in a series was developed and evaluated using toluene and TCE as model VOCs. When only TCE was applied to the UV reactor, greater than 99% of TCE was degraded and the concentration of soluble byproducts from photo-oxidation reaction increased significantly. However, the toluene and TCE mixture was not effectively degraded by the UV photo-oxidation standalone process. The hybrid system showed high toluene removal efficiencies, and TCE degradation at a low toluene/TCE ratio was improved by UV pretreatment. These findings indicated that the UV photo-oxidation were effective for TCE degradation when the concentration of toluene in the mixture was relatively low. A restively high toluene content in the mixture resulted in an inhibition of TCE degradation. Thus, chemical interactions in both photo-oxidation and biodegradation need to be carefully considered to enhance overall performance of the hybrid system.

• The Optical Journal
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• v.8 no.3 s.43
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• pp.27-38
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• 1996

• The Optical Journal
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• v.7 no.5 s.39
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• pp.36-39
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• 1995

• The Optical Journal
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• v.8 no.1 s.41
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• pp.91-96
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• 1996

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.319-320
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• 2006

In this paper, automatic sunvisor system is introduced for driver's safety and convenience. This system has the mechanism which keeps the sun off without obstruction of driver's sight. The mechanism can make the sunvisor move forward or rotate left while remaining inside inner roof. The control system consists of a CPU, a motor driver, light sensors, and the algorithm that can control the movement of sunvisor efficiently. When the light sensors take the sun light, they give the signal to the CPU and the CPU calculates the best position of the sunvisor with the information of driver's eyes height. Then, the CPU gives the signal to motors that can move the sunvisor.

• Journal of Sensor Science and Technology
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• v.20 no.1
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• pp.53-57
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• 2011

We developed a small methane detection system because methane gas is used in many areas and is dangerous. The developed system consisted of LD(Laser Diode) tuned a wavelength of $1.65\;{\mu}m$, two mirrors to collect a laser beam, photo detector. It could detect methane gas at a long range and its sensitivity was 1.98 V/$CH_4%$.

• Proceedings of the KIEE Conference
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• 2001.07e
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• pp.3-6
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• 2001

This paper is shows the configuration of the maximum power tracking control of Photo-voltaic and battery charge system. Up to now, the chopper system had the problem which a battery become a short life by reason of discontinuity of output current and its energy reduce. But in this paper, We propose the chopper system which maintain the successive output current and at the same time, control the maximum output location by change time-ratio using tracking of energy variation that occur because of the varied volume of insolation per a day and temperature.