• Journal of the Korean Vacuum Society
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• v.4 no.3
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• pp.261-269
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• 1995

본 실험에서는 실리콘 웨이퍼 위에 photoresist(PR)와 octadecyltrichlorosilane(OST, CH3((CH2)17SiCI3)를 입혀서 UV/zone 처리를 어떻게 유기물질들이 UV/zone과 반응하여, 어떻게 표면에서 제거되는지를 in-line으로 연결된 XPS로 분석하고 반응시킨 표면들의 거칠기(roughness)를 AFM을 이용하여 관찰하였다. 실험결과 상온에서 UV/zone 처리를 했을 경우, PR과 OTS같은 유기물질이 표면에서 산화되는 것을 알 수 있었으나 이들이 제거되지 않고 표면에 그대로 남아있음을 알 수 있었다. 그러나 가열하면서(PR:$250^{\circ}C$, ORS:$100^{\circ}C$)UV/ozone 처리를 하였을 경우 표면에서 산화됨과 동시에 이들 산화물들이 표면에서 제거됨을 알 수 있었다. XPS 분석으로부터 이들의 산화반응물은 PR과 OTS 모두 -CH2-, -CH2O-, =C=O, -COO-를 가지는 것으로 나타났으며, 열에너지에 의해서 이들이 표면에서 제거되는 것으로 나타났다. AFM 분석결과는 상온에서 UV/ozone 처리를 하였을 경우에 표면의 거칠기가 적은 반면, 가열하면서 UV/o-zone처리를 하였을 경우에는 표면의 거칠기가 다소 증가하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3B
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• pp.321-327
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• 2006

This study was performed to provide basic information for evaluating the efficiency and applicable extent of photocatalysis for the treatment of swine wastewater. Acid area was more efficient than neutral and alkalic areas in wastewater treatment, and level of pH3 was the most effective and the treatment efficiency continually increased as the amount of photocatalyst was increased. When the photocatalyst was increased, $TCOD_{Mn}$ was removed faster than chromaticity. Pollutants were more effectively eliminated with both UV light illumination and $TiO_2$ than with either UV or $TiO_2$ alone. The removal efficiency was increased with the addition of $H_2O_2$ as an oxidant, but the removal efficiency was decreased with over an dosage of $H_2O_2$. The optimal dosage of $H_2O_2$ was 200 mg/L. Continuous injection of $H_2O_2$ was required for effective oxidation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1798-1804
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• 2012

To prolong the shelf-life of domestic peaches, samples were treated with UV-C (0~10.0 $kJ/m^2$) and the spoiling rate and changes in physico-chemical and sensory properties were investigated. No spoiled peaches were observed within the first four days of storage in the control and 2.5 $kJ/m^2$ UV-C treatment groups. However, spoilage was observed in these groups on day six, and 29.17% and 25.0% of the samples showed spoilage on 10 day, respectively. Moreover, samples treated with greater than 5.0 $kJ/m^2$ of UV-C showed a higher percentage (41.67% or higher) of spoilage than those of the control or 2.5 $kJ/m^2$ UV-C treatment groups on 10 day. Additionally, weight changes in the peaches were the lower in the control group and 2.5 $kJ/m^2$ UV-C treatment group than in those treated with 5.0 $kJ/m^2$ of UV-C treatment or higher during 10 days of storage. There was no difference in pH among treatments, regardless of storage time. The hardness of the samples was not changed immediately after UV-C treatment, but that of samples treated with 5.0~10.0 $kJ/m^2$ of UV-C decreased rapidly after four days, when compared to the control and 2.5 $kJ/m^2$ UV-C treatment groups. No significant changes in the lightness and redness of the samples were observed in response to UV-C treatment, however, UV-C treatment led to a slight decrease in the yellowness of the samples. The initial taste, flavor, color, texture, and overall acceptance did not differ among control and UV-C treatments. The sensory score of the samples was the highest after 2 and 4 days of storage, while it decreased thereafter. In general, samples in the control and the 2.5 $kJ/m^2$ UV-C treatment groups showed higher sensory quality than those treated with UV-C at 5.0 $kJ/m^2$ or higher.

• Journal of Food Hygiene and Safety
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• v.32 no.1
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• pp.64-69
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• 2017

This study was conducted to investigate the effect of cold plasma combined with UV-C irradiation against Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes on lettuce. E. coli O157:H7, S. Typhimurium, and L. monocytogenes, corresponding to approximately 5.82, 5.09, 5.65 log CFU/g, were inoculated on lettuce, respectively. Then, the lettuce was treated with cold plasma, UV-C and combination (cold plasma + UV-C), respectively. The treated lettuce was stored for 9 days at $4^{\circ}C$ for microbiological analysis and sensory evaluation. Cold plasma reduced the populations of E. coli O157:H7, S. Typhimurium, and L. monocytogenes by 0.26, 0.65, and 0.93 log CFU/g, respectively. Each microorganism were reduced by 0.87, 0.88, and 1.14 log CFU/g after UV-C treatment. And, the combined treatment that was treated by cold plasma after UV-C treatment reduced the populations of inoculated microorganisms by 1.44, 2.70, 1.62 log CFU/g, respectively. The all treatment significantly (p < 0.05) reduced the populations of all inoculated bacteria compared to untreated lettuce. UV-C combined with cold plasma was the most effective for reducing the pathogenic bacteria on lettuce, by showing log-reductions of ${\geq}2.0\;log\;CFU/g$. All treatment was not significantly different until 6 day storage compared to control group in terms of appearance, texture and overall acceptability. Therefore, the combined treatment will be an effective intervention method to control the bacteria on lettuce.

• Research in Plant Disease
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• v.28 no.2
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• pp.61-68
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• 2022

Powdery mildew and two-spotted spider mite are detrimental to strawberry plants and are controlled with traditional pesticides. To accommodate consumer demand, eco-friendly methods of pest control are required. Strawberries were cultivated (in soil and in a hydroponic system) for two years, and ultraviolet B (UV-B) irradiation was used as an alternative pest control during the harvesting season. Three varieties were grown (Seolhyang, Kingsberry, and Durihyang), and four UV-B lamp/mulch (black, green, and light reflection sheet [LRS]) combinations were used during harvesting: UV-B+black or green mulch, UV-B+black or green+LRS, no UV-B+black or green, and no UV-B+black or green+LRS. In all varieties, powdery mildew was 65% more controlled when UV-B irradiation was used. The adult two-spotted spider mite density was lowest in the UV-B lamp+black or green+LRS treatments. Therefore, UV-B irradiation during the strawberry harvesting season could effectively control powdery mildew and two-spotted spider mite with little side effect on the plants.

• Journal of Environmental Science International
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• v.5 no.5
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• pp.635-642
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• 1996

Rice plants, cv. Koshihikari, were subjected to the biologically effective ultraviolet-B(UV-BBE) radiation {daily dose : 0.0 (control) and 11.5 (enhanced UV-B) KJ m-2} to investigate the effect of enhanced UV-B radiation on lipid peroxidation and to determine whether carotenoids and polyamines are involved in protection mechanism against enhanced UV-B radiation. Enhanced UV-B radiation significantly depressed plant dW weight. Malondialdehyde (MDA) content in rice leaves was increased by about 30% after 6 days of UV-B irradiation. Total carotenoid contents tended to slightly decrease with the UV-B irradiation, even though there was no significance. In rice leaves, 3 major polyamines, putrescine, spermidine and spermine are observed. All of the polyamine contents were increased with UV-B irradiation. The results suggest that enhanced UV- B radiation caused oxidative stress on lipids and that polyamines may serve as a biochemiral protectant against increased UV-B radiation in rice plants.

• 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 Life Science
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• v.27 no.9
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• pp.975-985
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• 2017

To investigate the beneficial effects of an agar gel mask (AGM) on UV-induced photoaging, SKH-1 hairless mice were treated with a topical application of AGM and an AGM dipped in essence (AGMdE). The mice were divided into an no radiation group, UV + AGM, UV + AGMdE, and UV + vehicle (PBS) treatment groups. Alterations in skin wrinkles, skin phenotype, histological structures, oxidative status, and toxicity were then evaluated during 4 weeks of exposure. The topical application of AGM and AGMdE inhibited wrinkle formation, suppressed the erythema index, prevented transepidermal water loss, and enhanced skin hydration. In addition, epidermal thickness recovered to a similar level as that in the no irradiation group in the UV + AGM and UV + AGMdE treatment groups compared with the UV + vehicle (distilled water) group. Furthermore, the expression levels of matrix metalloproteinase-1 (MMP-1) and tyrosinase were reduced in the UV + AGM and UV + AGMdE treatment groups, although the highest level varied. Moreover, superoxide dismutase (SOD) activity was significantly lower in the UV + AGM and UV + AGMdE treatment groups as compared with the UV + vehicle group. No significant alterations induced by most toxic compounds were measured in serum biochemical markers and liver and kidney histological features of the UV + AGM and UV + AGMdE treatment groups. These results suggest that AGM may protect against skin aging by regulating skin morphology, histopathological structures, and oxidative conditions.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.5
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• pp.576-585
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• 2020

This study quantitatively investigated the increase in ballasting time through numerical calculations when an ultraviolet (UV) ballast water management system (BWMS) is installed on an existing vessel. The calculation results indicate that the ballasting time of a gas carrier having 55,000 dead weight tonnage was 2.152 hours without installation of the UV BWMS and implementation of a flow control function. Ballasting time increased by 14.2% after installing the UV BWMS, and it increased by 20.4% with both its installation and implementation of a flow control function. If actual conditions are taken into account, ballasting time after installing the UV BWMS is estimated to increase by at least 30% compared with current ballasting time. Therefore, when concerned parties select a UV type BWMS, it is advisable for them to minimize ship operation losses from an increase in ballasting time by considering the capacity of the actual ballast pumps on board and the flow energy loss of the UV BWMS. Additionally, it is recommended that a BWMS with larger capacity, larger pipes, and pipes with inside coatings be used to minimize the increase in ballasting time after installation of the BWMS.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.69-69
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• 2011

폴리케톤 섬유는 제조 원료로 에틸렌과 일산화탄소를 사용하여 합성한 공중합체 물질로 생산에 필요한 비용을 크게 절약할 수 있다. 폴리케톤 섬유는 p-아라미드 섬유에 근접하는 고강도 고탄성을 가진 섬유로 우수한 내화학성을 가지며, 고무와의 계면접착이 우수하다는 특성을 가지고 있어 MRG(Mechanical Rubber Goods)용 보강재 및 타이어코드로의 사용에 대한 관심이 증대하고 있다. 그러나 폴리케톤 섬유의 생산 및 산업현장에서의 활용은 아직 적은 상태로 그 특성에 대한 연구가 미흡한 상태이다. 따라서 본 연구에서는 폴리케톤 섬유의 기본적인 특성 분석을 하고, 폴리케톤 소재의 표면을 UV 조사와 인산을 이용한 산처리 방법을 이용하여 처리하고 표면처리에 따른 폴리케톤 섬유의 표면특성 및 물성특성을 분석하였다. UV 조사 처리시 에너지 변화와 산처리시의 pH조건 및 처리시간의 변화에 따른 표면의 미세구조를 SEM과 AFM 등을 이용하여 관찰한 결과, UV 에너지와 산처리 조건의 증가에 따라 표면요철이 증가를 보이다가 과도한 처리에 의하여 표면에 degradation이 발생하였다. 또한 UV 에너지 및 산처리 조건에 따른 열적, 화학적 그리고 물리적 특성의 변화를 분석하였다.