• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6434-6440
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• 2013

In this paper, an integrated control system is proposed for automatic control and remote monitoring of pipeline type UV sterilizer. The proposed system can control the cleaning wiper in the sterilizer with various cleaning motions, and periodically check the contamination level of the UV lamps with the UV power sensors. Therefore, sterilizer repair and maintenance can be more effectively done. In addition, the control system based on the open-source processor can communicate with external smart devices via Bluetooth, and thus wirelessly exchange control commands and sensor data. Furthermore, the system is able to flexibly cope with changes of cleaning motions and sensors since its firmware can be wirelessly upgraded by using the smart device. Consequently, the proposed system is suitable to construct a smart sewage treatment system in small towns.

• The Journal of Natural Sciences
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• v.11 no.1
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• pp.41-44
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• 1999

For the purpose of improving the UV sterilization for toothbrush, the sterilizing effects by the UV light were studied. When toothbrushes were treated with the UV light for 5, 15, 30, 60 minutes, the sufficient antibacterial effect were shown after 15 minutes with 80% of bactericidal effects. To prevent the brownish stain on the sterilizer which was caused by the long exposure of UV light, no UV treatment for two hours after 15 minutes exposure were scheduled and then 3 minutes re-exposure were performed, which showed 97% of bactericidal effect. Also, the antibacterial effects of the sterilizer showed different results depending on the position of the toothbrush, it was recommended to adjust toothbrush to be exposed by the UV light directly.

• Journal of the Korean institute of surface engineering
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• v.41 no.2
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• pp.76-82
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• 2008

We investigated sterilization characteristics of UV lights by counting the number of bacteria units with varying sterilization time and distance from the light source. We focused on an idea that UV light of 184.9 nm could generate ozone and developed a new sterilizer. The UV-ozone duplex system sterilized bacteria faster than UV-only sterilizers. To reduce shadowing effects by target objects, we used UV transparent quartz plate as a support and put a reflecting plate. Distribution of UV irradiation intensity and ozone supply were analyzed by a 3D model and measured by a semiconductor UV sensor. But even with an Al reflector, multi-layered pens could not be treated properly from UV irradiation only. Ozone generating lamp could treat more uniformly multi-layered pens with a stirring fan by supplying ozone to shadowed surfaces.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.3
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• pp.238-246
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• 2024

Objectives: A collective of workers in the company's cafeteria encountered symptoms such as stinging and watering in and around the eyes, a sensation of sand in the eyes, erythema, swelling, and peeling of the skin on the face and neck. The objective of this study is to pinpoint the causes of these symptoms and propose preventive measures. Methods: Following preliminary on-site investigations, worker interviews, and literature research, it was determined that the most probable cause of the symptoms was ultraviolet rays emitted from a UV sterilizer. Consequently, the study measured and assessed the effective amount of ultraviolet radiation emitted by the sterilizer. Results: When operating with the curtain-type door of the ultraviolet sterilizer open, it was observed to surpass the 0.1 μW/cm2 8-hour work exposure standard recommended by ACGIH TLV in most kitchen workspaces. The evaluation of the maximum allowable exposure time based on the distance from the ultraviolet sterilizer indicated only 4.2 seconds at a distance of 0.2 m with the curtain door open, and merely 1.7 minutes at a distance of 1 m. Conclusions: This study confirmed that the symptoms among restaurant workers emerged immediately after the installation of the ultraviolet sterilizer, and these symptoms were consistent with those associated with exposure to ultraviolet rays. Furthermore, the assessment revealed that the exposure level to ultraviolet rays could be exceeded established exposure standards. It was recommended that the existing ultraviolet sterilizer be replaced with one featuring a glass door, and facility improvements should be made, such as implementing an automatic mechanism to turn off the ultraviolet lamp when the door is opened.

• Proceedings of the Korean Environmental Health Society Conference
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• 2001.04a
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• pp.103-105
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• 2001

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.6
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• pp.581-586
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• 2005

Recently, the use of UVGI system has been increasing in both medical and nonmedical buildings for the control of environmental microorganisms. In the present study, irradiance performance test of UVC lamp was carried out and indoor air sterilization effect of UV ray for preventing transimission of air borne contagion was investigated by using manufactured UVC air sterilizer. Experimental results show that the effective irradiance of UVC lamp is strongly dependent on air velocity and temperature in irradiance performance test. An individual microbiological killing effectiveness experiment also shows that the average kill rate of two microbiological samples such as bacteria and fungus is about $92\%$ by using manufactured UVC air sterilizer. Additionally irradiance performance experimental results also show that the ballast is very important factor to keep up irradiance performance of UVC lamp.

• The Journal of Advanced Prosthodontics
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• v.5 no.1
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• pp.2-8
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• 2013

PURPOSE. Autoclaves and UV sterilizers have been commonly used to prevent cross-infections between dental patients and dental instruments or materials contaminated by saliva and blood. To develop a dental sterilizer which can sterilize most materials, such as metals, rubbers, and plastics, the sterilization effect of an atmospheric pressure non-thermal air plasma device was evaluated. MATERIALS AND METHODS. After inoculating E. coli and B. subtilis the diamond burs and polyvinyl siloxane materials were sterilized by exposing them to the plasma for different lengths of time (30, 60, 90, 120, 180 and, 240 seconds). The diamond burs and polyvinyl siloxane materials were immersed in PBS solutions, cultured on agar plates and quantified by counting the colony forming units. The data were analyzed using one-way ANOVA and significance was assessed by the LSD post hoc test (${\alpha}$=0.05). RESULTS. The device was effective in killing E. coli contained in the plasma device compared with the UV sterilizer. The atmospheric pressure non-thermal air plasma device contributed greatly to the sterilization of diamond burs and polyvinyl siloxane materials inoculated with E. coli and B. subtilis. Diamond burs and polyvinyl siloxane materials inoculated with E. coli was effective after 60 and 90 seconds. The diamond burs and polyvinyl siloxane materials inoculated with B. subtilis was effective after 120 and 180 seconds. CONCLUSION. The atmospheric pressure non-thermal air plasma device was effective in killing both E. coli and B. subtilis, and was more effective in killing E. coli than the UV sterilizer.

• Current Optics and Photonics
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• v.6 no.2
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• pp.202-211
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• 2022

In the pasteurization of escalator handrails using ultraviolet (UV) sterilizers, a combination of light distribution and escalator speed has priority over other important factors. Furthermore, since part of the escalator handrail has a curved structure, proper design is needed to improve the sterilization rate on the surfaces touched by users. In this paper, two types of sterilizers satisfying these conditions are manufactured with 275-nm UV-C LEDs, after modeling the three-dimensional (3D) structure of an escalator handrail and simulating optical distributions of UV-C irradiation on the handrail's surface according to light-emitting diode (LED) positions and reflector variations in the sterilizers. Pasteurization experiments with the UV-C LED sterilizers are conducted on six types of gram-positive and gram-negative bacteria, with exposure times of 0.2, 5, and 15 s at an actual installation distance of 20 mm. The sterilization rates for the gram-positive bacteria are 10.63% to 27.94% at 0.2 s, 89.44% to 96.30% at 5 s, and 99.64% to 99.88% at 15 s. Those for the gram-negative bacteria are 57.70% to 77.63% at 0.2 s, 98.90% to 99.49% at 5 s, and 99.88% to 99.99% at 15 s. The power consumption of the UV-C LED sterilizer is about 8 W, which can be supplied by a self-generation module instead of an external power supply.

• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.652-656
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• 2009

A cylindrical ultraviolet (UV) sterilization system was developed for decreasing microorganisms in takju. The takju was passed through 110 strips of honeycomb-type teflon tubing with 9 UV lamps (1,395 W) set between the teflon tubes. Thus, during passage, the takju was effectively exposed to the UV rays without loss. In terms of the overall quality aspects of the takju, the optimum sterilization condition was set for 4 min at 2 L/min. A 2-3 log cycle decrease in viable cell numbers of total bacteria and fungi was observed at this operating condition. Quality changes in the UV-sterilized takju were examined via UV irradiation of samples followed by storage at 30oC for 8 days. To evaluate the quality changes, pH, amino nitrogen content, acidity, reducing sugar content, and viable cell numbers of total bacteria and fungi were measured. Increases in pH, acidity, and amino nitrogen content were observed in both the takju control and UV sterilized takju with increasing storage time. However, reducing sugar content was decreased in both samples. The L, a, and b values of the control takju and UV sterilized takju showed similar trends over the storage period. Viable cell numbers of fungi did not change in the control or UV sterilized takju during storage, showing approximately $10^8\;CFU/mL$ and $10^4-10^5\;CFU/mL$, respectively. In addition, viable cell numbers of total bacteria remained lower in the UV sterilized takju over 4 days compared to the non-sterilized takju.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.248-249
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• 2009

자외선 램프를 이용한 살균기는 고전압 방전과 달리 오존의 발생을 최소화 하면서 짧은 시간에 원하는 물체를 살균할 수 있는 장점이 있다. 본 연구에서는 인체의 피부에 직접 접촉하는 티슈들의 포장 상태에서 세균의 밀도를 조사하고 그 결과 살균이 필요한 수준이라는 것을 파악한 다음, 공중 화장실용 공동 티슈 공급기에 적합한 살균기를 설계, 제작하고 그 효과를 세균 배양 실험을 통하여 확인하였다.