• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.179-183
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• 2011

In this study, photochemical effects (OH radical formation) in the photoreactor was investigated to analyze UV-C intensity distribution. In addition, The influence radius of the UV-C lamp was measured at various dose of $TiO_2$ (Degussa P-25). The photoreactor used in this study was bath type reactor which is made by acrylic and the UV-C lamp (SANKYO DENKI, wavelength : 254 nm, Diameter : 2.2 cm, Length : 18.5 cm) was used as photo source. The maximum electric power consumption of the UV lamp was 10.5 W. The OH radical formation by UV-C was measured by KI dosimetry methods. From the results, the effective OH radical formation was occurred under the following condition. The reasonable distance of UV-C lamp is within 13 cm and the intensity of UV-C lamp should be more than 0.367 mW/$cm^2$. Moreover, the concentration of catalyst affects on the influence radius of the UV lamp.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.675-681
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• 2011

In this paper, we dealt with the design and fabrication of a medium pressure ultra-violet (UV) lamp and a magnetic ballast which are main components for ballast water treatment systems (BWTS). To acquire an optimal discharge condition of UV lamp, electrical and optical characteristics depending on the argon gas volume and the amount of mercury were experimentally analyzed. Rated voltage, current and power consumption of a prototype lamp were 490 [V], 8.6 [A] and 4.0 [kW], respectively. UV intensity of the lamp was 15 [%] higher than that of an equivalent lamp which is used in a BWTS. The magnetic ballast was designed in a UI core type through theoretical analysis and simulation. The open voltage and the rated power consumption of the ballast were 920 [V] and 8.5 [kVA] respectively. The disinfection efficacy which is carried out in a BWTS equipped with the UV lamp and magnetic ballast was over 99.99 [%], and this satisfy the IMO regulations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.5
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• pp.505-512
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• 2021

A 3D model was developed to calculate the UV intensity of a submerged-type UV disinfection reactor. Numerical experiments were conducted by inputting the design factors of an open channel-type disinfection reactor and a pipe-type disinfection reactor that were installed in an actual sewage treatment plant. The following data were obtained: The average UV intensity of the installed open channel-type reactor and pipe-type reactor was 7.87 mW/cm² and 13.09 mW/cm², respectively; the UV dose reflecting the UV irradiation time and taking into account attenuation effects such as mixing imbalance, lamp aging, temperature, and fouling, was expected to be 21.1 mJ/cm² and 24.8 mJ/cm², respectively, and these values are 5 % and 24 % higher than the target UV dose of 20 mJ/cm², respectively. By using the UV3D model, the optimal lamp position, which maximizes the average UV intensity without changing the size of the disinfection reactor or lamp output power, can be found. In this case, by only adjusting the lamp position, the average UV intensity can be increased by 0.9 % for the open channel-type and 0.5 % for the pipe-type, respectively. A better average UV intensity can be obtained by model simulation. By adjusting the horizontal and vertical ratio of the open channel-type reactor and by moving the lamp position, the average UV intensity can be increased by 7.4 % more than the present case.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.3822-3826
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• 2012

We have studied the effect of temperature and exposure time on the UV curing rate of Urethane Acrylate. UV dose has been modulated by changing the electric power, and temperature has been controled by coating rate and water temperature of the coating roll. Curing rate was evaluated by measuring gel fraction of the cured film. It has been found that effect of coating velocity on the gel fraction of the final film is predominant, but role of temperature of the UV chamber is negligible. These observations imply that exposure time of UV light is critical to have a fully cured film. To better understand the effect of design and operating condition of UV coater on the behavior of UV curing of Urethane Acrylate, we have also conducted heat-flux analysis of UV chamber.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.10
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• pp.133-137
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• 2016

Use of UV gel for nail management have been increasing gradually. In order to develop an UV lamp necessary to UV gel, in this study, we was designed circuits of the UV-LED lamp. Power supply part that supplies constant power to the several UV-LEDs, was designed the circuit with the method of DC-DC converter. Taking into account the direction of the thumb nail and the position of the little finger nail, it was placed UV-LEDs. Input power of the power supply part was used as a battery voltage of 3.8[V]. The output voltage of the power supply part was appeared in approximately 3.1[V]. And in order to examine the state of change of the output voltage according to the amount of current consumption of UV-LEDs, after inserting of load resister, the output voltage was more than about 3.0[V] in the simulation results of the power supply part while changing the resistance value.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.230-232
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• 2006

본 논문은 Spice해석을 이용하여 push-pull inverter 방식의 전자식 안정기회로를 해석하고 안정기를 설계 제작하였다. Spice 시뮬레이션을 사용함으로서 전자식 안정기의 설계에 있어서 전기적 특성을 예측, 평가 할 수 있었고 이를 바탕으로 145W저압 UV램프용 전자식 안정기를 개발하였다.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.12
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• pp.1141-1146
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• 2010

Isolated the heterotrophic aerobic bacteria in sandfiltered water on NA and TSBA solid medium, selected 8 dominant species and identified by Sherlock System. Each samples are irradiated 0, 5, 16, 40 and $60\;mJ/cm^2$ using on CBD (Collimated Beam Device) Medium Pressure UV lamp after these identified bacterium did liquid culture how to make $10^6{\sim}10^7\;cells/mL$ suspended in dilution water. Then cultured bacteria are estimated inactivation rate on plate media. Identified Gram positive group are Bacillus Subtilus, Bacillus megaterium, Rhodococcus erythropolis and Microbacterium laevaniformans; Gram negative group are Pseudomonas vesicularis, Pseudomonas pseudoflava, Alcaligenes paradoxus and Zooglea ramigera. These isolation of bacterium are more stronger reference strain and high resistance of MP UV irradiation, Besides Gram negative bacterium are more sensitive Gram positive bacterium on MP UV dose. Now we are estimating to $60{\sim}100\;mJ/cm^2$ MP UV dose for efficient disinfection in water treatment plant.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.12 s.189
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• pp.117-121
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• 2006

Generally, micro-stereolithography technology uses laser and complex optical system as light source and light delivery system, respectively. In this research, a novel micro-stereolithography technology that uses UV lamp that is more economical than UV laser as light source and optical fiber that is simpler than previous light delivery system has been developed. Furthermore, precise control system that is composed of 3-axis linear stage and shutter has been used to fabricate truly three dimensional micro-structure. For confirming the feasibility of developed micro-stereolithography apparatus, the solidification experiments were conducted. The solidification widths and depths datum of photopolymer as varying scanning speed of the UV light have been obtained. Using developed apparatus, some micro structures were fabricated successfully.

• Journal of the Mineralogical Society of Korea
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• v.27 no.4
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• pp.223-233
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• 2014

Cyanidation method has been used to extract high-purity gold and silver in mining industry. Such mining activities have used a large amount of cyanide, and the mine wastewater contained a high level of cyanide has brought about pollution of surrounding aqueous environments. This research was initiated to study $TiO_2$-catalytic UV-LED photo-oxidation to remove cyanide from the mine wastewater. UV lamp has been generally used as a light source in conventional photo-oxidation so far, but it shows numerous drawbacks. For this reason, this study focused on the evaluation of applicability of UV-LED as an alternative light source in cyanide photo-oxidation process. Three types of $TiO_2$ photo-catalyst were compared in terms of performance of photo-oxidation of cyanide, and the results show that Degussa P25 was the most efficient. In addition, four types of UV-LED were tested to compare their efficiencies of cyanide photo-oxidation, and their efficacy was increased in the order of 365 nm lamp-type > 365 nm can-type > 280 nm can-type > 420 nm lamp-type. Not only did this study demonstrate that UV-LED can be used in the photo-oxidation of cyanide as an alternative light source of UV lamp, but also confirmed that the performance of photo-oxidation was significantly influenced by the type of $TiO_2$ catalysts.

• 보존과학연구
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• s.33
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• pp.85-97
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• 2012

In this study, reliability assessment was carried out on UV(ultraviolet) indicators for the application of the indicator method on cultural heritages. As a result, some UV indicators(L, K, and M) proved to be unsuitable due to their low reactivity to UV and high reactivity to RH(relative humidity). On the other hand, indicator S showed considerable color changes and fading due to UV-B and UV-C according to the integral amount of UV irradiation. Indicator S showed the most distinct reaction to UV and a remarkable applicability to exhibition light, which are used in museums. Therefore, UV indicator S is an easy and useful monitoring tool for light environment management in cultural- property conservation facilities.