• Journal of Radiation Industry
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• v.4 no.1
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• pp.39-45
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• 2010

The pollution of antibiotics is a major cause of spreading antibiotics resistant bacteria in the environment. Applications of ozonation, UV, and ${\gamma}-ray$ irradiations have been introduced to remove antibiotics in the effluents from wastewater treatment system. In this study, we compared the chemical (HPLC) and biological (antimicrobial susceptibility test, AMS) assays in measuring of the concentrations of residual antibiotics after ${\gamma}-ray$ and UV irradiation. Most samples were degraded by ${\gamma}-ray$ irradiation (1~2 kGy). However, lincomycin and tetracycline were not degraded by UV irradiation. The concentration of residual antibiotics, that was treated with ${\gamma}-ray$ and UV irradiation, measuring by bioassay was similar to HPLC. The concentrations of ${\gamma}-ray$ irradiated cephradine measured by AMS test were 2 times higher than that of HPLC assay, indicating AMS test is more sensitive than HPLC assay. These results indicate that ${\gamma}-ray$ irradiation technique is more useful than UV irradiation, and biological assay is more useful to detect the antibiotics and toxic intermediates in antibiotics degradation.

• Journal of the Semiconductor & Display Technology
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• v.6 no.1 s.18
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• pp.65-69
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• 2007

A design of experiments was applied in order to investigate the effect of processing variables in UV irradiation on the electrical/optical properties in indium-zinc oxide thin films, The processing variables, equivalently input variables are listed as UV irradiation time, oxygen flow rate, and chamber pressure. The statistical significance of Ultra Violet (UV) treatment was confirmed using a paired-t test. The full factorial $2^3$ design was employed to determine significant main and interaction effects in UV irradiation process. The chamber pressure and the interaction between UV irradiation time and $O_2$ flow rate were found to be statistically significant at the significance level of 0.1. Furthermore, the optimized approach was proposed in achieving the improved conductivity after UV irradiation.

• Journal of Food Hygiene and Safety
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• v.9 no.1
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• pp.15-21
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• 1994

The mutagenic activity of four phenothiazine derivatives such as chlorpromazine, perphenazine, trifluoperazine and thioridazine in conjunction with UV-A irradiation or not based on the Ames plate incorporation test in the presence and absence of liver microsomal enzyme(S9 fraction). None of these compounds and their photo-excited were detected as mutagen in the Salmonella microsome assay with TA 98 and TA 100.

• The Journal of Advanced Prosthodontics
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• v.3 no.2
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• pp.63-68
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• 2011

PURPOSE. The object of this study was to investigate the effect of UV irradiation (by a general commercial UV sterilizer) on anodized titanium surface. Surface characteristics and cellular responses were compared between anodized titanium discs and UV irradiated anodized titanium discs. MATERIALS AND METHODS. Titanium discs were anodized and divided into the following groups: Group 1, anodized (control), and Goup 2, anodized and UV irradiated for 24 hours. The surface characteristics including contact angle, roughness, phase of oxide layer, and chemical elemental composition were inspected. The osteoblast-like human osteogenic sarcoma (HOS) cells were cultured on control and test group discs. Initial cellular attachment, MTS-based cell proliferation assay, and ALP synthesis level were compared between the two groups for the evaluation of cellular response. RESULTS. After UV irradiation, the contact angle decreased significantly (P<.001). The surface roughness and phase of oxide layer did not show definite changes, but carbon showed a considerable decrease after UV irradiation. Initial cell attachment was increased in test group (P=.004). Cells cultured on test group samples proliferated more actively (P=.009 at day 2, 5, and 7) and the ALP synthesis also increased in cells cultured on the test group (P=.016 at day 3, P=.009 at day 7 and 14). CONCLUSION. UV irradiation induced enhanced wettability, and increased initial cellular responses of HOS cells on anodized titanium surface.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.1
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• pp.70-82
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• 2008

Objective : The purpose of this study is to examine the effects of Baickbujasan(BB) on the skin damage and depigmentation. Method : The inhibition of tyrosinase activity, melanogenesis and cell viability in cultured B16 melanoma cells were measured. In order to test effects of reduction of melanogenesis, B16 F-10 mouse melanoma stem line was employed to extract melanin from cultured cell, where BB was added or not, and was dissolved in alkali for colorimetric analysis. Also, in order to test skin alteration in C57BL/6 after UV irradiation, the animals were grouped into a UV urradiation group and UV irradiation after BB application group. Dopa oxidase tissue staining was excuted to invesitage the change in the distribution of active melanin cell. The distribution of active melanin cell in inner skin of iNOS after damage from UVB irradiation and the manifestation condition of P53 which takes part in natural death of keratinocyte were examined. Result : The results indicate that BB has significant effects on tyrosinase activity, and melanogenesis in vivo test. BB seems to reduce C57BL/6, external dermatological damage, for instance, erythematous papule, eczema, loss of keratinocyte, reduction in pus, and relieves dermatological damages. Conclusion : BB can be applied externally for UV protection and depigmentation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.3
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• pp.250-257
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• 2004

Recently, the use of UVC lamps inside building air-conditioning 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 surface sterilization effect of UV ray was investigated by using UV ray irradiation experimental chamber and pilot system. Experimental results show that the effective irradiance of UVC lamp is strongly dependent on air velocity and temperature with exception of relative huminity in air-conditioning system. An individual microbiological kill effectiveness experiment also shows that the fractional kill of two microbiological samples such as E. Coli and Legionella is roughly the same as the estimated fractional kill in the case of chamber test and pilot system test.

• Environmental Engineering Research
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• v.22 no.4
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• pp.426-431
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• 2017

Some phototoxicity of titanium dioxide nanoparticles ($TiO_2$ NPs) has been reported in recent years in studies with fish embryos or larvae. However, it is necessary to focus on the potential effects of embryonic exposure due to irreversible abnormalities and mortalities observed in sac-fry, and to expand various fish embryos to generate multiple test species. The aim of this study was to evaluate the effects of $TiO_2$ NPs under different irradiation conditions in exposed Oryzias latipes (O. latipes) at the embryonic and sac-fry stages. The effects of different irradiation conditions were observed using ultra-violet (UV) and visible light, and the corresponding effects were monitored by determining cumulative mortality and abnormality. O. latipes were exposed for 8 d to 0, 1, 5, 10, or 50 mg/L $TiO_2$ NPs under UV ($4,818.86mW/m^2$ at the bottom of clear vials) or visible light, after which the embryos were transferred to NP-free embryo-rearing solution until 16 days post fertilization (dpf). Abnormalities of embryos and sac-fry increased at high $TiO_2$ NP concentrations under UV irradiation, compared to control samples treated with visible light or UV irradiation alone. This work provides information regarding the phototoxicity of $TiO_2$ NPs using O. latipes at the embryonic and sac-fry stages.

• Journal of Technologic Dentistry
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• v.42 no.2
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• pp.113-120
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• 2020

Purpose: This study is to compare and analyze the shrinkage of the specimen after UV irradiation of UV cured resin at 5, 15, and 30 minutes. Methods: A cylindrical UV cured specimen was produced using a stainless steel mold. UV cured resin specimens were prepared in three groups: 5 minutes cured (5M), 15 minutes cured (15M), and 30 minutes cured (30M). The measurement was made in total 3rd. The measurement was made in total 3rd. The primary measurement was made after 24 hours using a digital measuring instrument. The 2nd and 3rd measurements were deposited in a constant temperature water bath and the shrinkage was measured. The measured data was calculated by referring to the ASTM C326 linear measurement calculation method. T-test and One-way ANOVA were performed to test the significance between groups. The post-test was conducted with Tukey (α=0.05). Results: When the inner diameter and the outer diameter of the three groups not placed in the water bath were compared and analyzed, the contraction was the smallest at 6.8% in the 5M group, and the contraction was the largest at 7.3% in the 30M group. In the outer diameter, the contraction of the 5M group was the smallest at 3.5%, and the contraction of the 30M group was the largest at 4.5%. Shrinkage decreased in all three groups immersed in a water bath for 3-7 days. Conclusion: In the UV cured resin specimen, the shrinkage increased as the amount of UV irradiation increased.

• Journal of Environmental Health Sciences
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• v.26 no.2
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• pp.49-58
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• 2000

The present study was performed to investigate photodegradation rate constants and degradation products of phosphamidon and profenofos by the USEPA method. The two pesticides were very stable in 16 days exposure of sunlight from September 3 to 22, 1999 and humic acid had no sensitizing effect on the photolysis of each pesticide in sunlight. In the UV irradiation test, phosphamidon was rapidly degraded as increasing UV intensity. In case of UV irradiation with TiO2 and with TiO2 powder amount, degradation of profenofos showed no significant difference with UV irradiation. Photodegradation rate of profenofos was slower than that of phosphamidon. In order to identify photolysis products, the extracts of degradation products were analyzed by GC/MS. The mass spectra of photolysis products of phosphamidon were at m/z 153 and 149, those of the profenofos were at m/z 208 and 240, respectively. It was suggested that the photolysis products of phosphamidon were 0, 0-dimethyl phosphate(DMP) and N, N-diethylchloroacetamide, those of profenofos were 4-bromo-2-chlorophenol and 0-ethyl-S-propyl phosphate.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.634-637
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• 2012

In strawberry production, among others, the high incidence of diseases by pathogenic fungi resulting in the reduction of fruit yield and quality requires the development of eco-friendly management systems rather than chemical sprays to control them. The diameter of colonies grown in media at $25^{\circ}C$ for 5 days was measured to evaluate the in vitro inhibition of mycelial growth of 5 pathogenic fungi by irradiation with ultraviolet (UV-C, 264 nm). The mycelial growth of 5 pathogenic fungi was inhibited in potato dextrose agar (PDA) by the irradiation of UV-C for 1 hour a day, and was dramatically inhibited by the irradiation of UV-C for 9-12 h a day. The irradiation of UV-C for 9-12 h a day inhibited completely the growth of the late blight pathogen, Phytophthora cactorum. The irradiation distance of 40 to 50 cm was effective for the inhibition of mycelial growth of fungi. The mycelial growth of fungi without pre-incubation was inhibited strongly by UV-C irradiation compared to fungi pre-incubated for 2 days without light. The mycelia growth of Colletotrichum gloeosprioides and Fusarium oxysporum was inhibited strongly by UV-C irradiation in vegetable 8 juice agar compared to PDA.