• Journal of The Korean Astronomical Society
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• v.34 no.2
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• pp.59-66
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• 2001

In this paper, we investigate the correlation between the radial ultraviolet color distribution and the shapes of the ultraviolet isophote for elliptical galaxies (M32, NGC 1399) and spiral bulges (of M31, M81) by using their archival UIT images. For M31, M81, and NGC 1399, the radial ultraviolet color distributions show a two-component trend; as the distance from the galactic center increase the color becomes redder in the inner region while it becomes bluer in the outer region. On the other hand, the color of M32 continues to become bluer with the increasing galactocentric distance. We also find, unlike the optical/IR images, significant variations of the position angle and the ellipticity in the ultraviolet isophotes of M31, M81, and NGC 1399 through the inner regions. For M32, the variation is significant in the outer region. Since these variation implies the triaxiality of their intrinsic shapes, we suggest that the early-type galaxies and spiral bulges with a radial color gradient in ultraviolet tend to have a triaxiality. On the other hand, the shape parameter characterized by the fourth order cosine Fourier coefficient of the isophote, a(4)/a, indicates that the systematic deviations of the ultraviolet isophotes of the four galaxies are smaller than $\~0.2\%$ in units of the semi-major axis. The latter result implies that the ultraviolet isophotes of the galaxies have a pure elliptical shape rather than the boxy or disky shapes. Therefore, there is no clear evidence of correlation between the radial ultra-violet color gradient and the boxy/disky shapes of isophotes.

• Journal of Radiation Protection and Research
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• v.26 no.4
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• pp.425-432
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• 2001

A bacteria infection on film cassette contact surface was examined at the diagnostic radiology department. Studies have demonstrated a bactericidal effect of ultraviolet irradiation, and to assess the contamination level on film cassette contact surface as a predictor of patient prevent from nosocomial infection. The study showed that the laboratory result was identified non-pathologic and pathologic bacterial in the five different cassette size of the contact surface. Film cassettes were exposed to ultraviolet light for 1, 2 and 3 minutes. Ultraviolet light disinfection practices suitable for bacteria. The study concludes that presence of a bacterial infection will prevent a using antiseptic technique on film cassette contact surface. In conclusion, ultraviolet irradiate on film cassette over the surface more than 2 minutes. Ultraviolet dose of $1565 {\mu}W{\codt}s/cm^2$ Win in 30 second relative to ultraviolet dose in time.

• Textile Coloration and Finishing
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• v.10 no.4
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• pp.53-61
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• 1998

The absorptions of ultraviolet rays of benzophenone derivatives were investigated in terms of the position of substituent, especially hydroxyl group. When the derivatives were added to the aqueous solution of Rhodamin B, which has very low light-fastness, all of them delayed the photofading of Rhodamin B solution. But on the fabrics, only the derivatives with the hydroxyl group at 2-position showed the good ability of ultraviolet rays absorption. The benzophenone derivatives absorb ultraviolet rays to form a hydrogen bond between hydroxyl group and carbonyl group, and return to their original structure by releasing heat energy. In solution, the derivatives can form a intermolecular hydrogen bond, and absorb the ultraviolet rays. But on the fabric, the intermolecular hydrogen bond is impossible, only hydroxyl group of 2-position forms a intramolecular hydrogen bond, and that makes the derivatives on the fabric absorb ultraviolet rays.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1219-1226
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• 2017

In this paper, it is performed the optimal design of the UV LED bar which can be used variously. The UV LED Bar emits ultraviolet rays, so it is important to emit ultraviolet rays constantly for the purpose of use. In order to emit a certain amount of ultraviolet rays as ever, the ultraviolet ray emission should be driven by a constant current source within the operable input voltage range. And also the heat dissipation is particularly important because of the long ultraviolet emission retention time due to the UV utilization characteristics. In addition, since human body protection is essential, the algorithm is configured to operate according to human body detection using distance sensor and Bluetooth. Three 365nm UV LEDs were used in series to emit ultraviolet UVA, operating at the constant current of 500mA with an efficiency of 87.5% and a power consumption of 6.006W. The ultraviolet radiation dose was measured at $5.35mW/cm^2$ at the distance of 10 cm when measured by the Lutron ultraviolet measuring instruments.

• Journal of Korean Physical Therapy Science
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• v.6 no.3
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• pp.63-82
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• 1999

Recent studies have revealed that Nitric oxide(NO) was one of the demonstration for the physiological regulator, endothelial derived relaxing factor(EDRF) and that NO was produced by ultraviolet irradiation in human. Thus, the present author have carried out a experimental study on the change of hematological, histological value of ultraviolet irradiation in sprague-dawley rats. The subjects were divided into four groups of ten rats each selected at random. There were 4 groups: 1. no irradiation control; 2. ultraviolet $75mJ/cm^2$ irradiation group; 3. ultraviolet $150mJ/cm^2$ irradiation group; 4. ultraviolet $225mJ/cm^2$ group. After a irradiation, hematological and histological tests were performed to observe erythrocyte, hemoglobin, hematocrit, MCH, MCHC, MCV, $O_2$ saturation, pH, $PO_2,\;PCO_2$ value and to observe histological changes. In hematological tests, erythrocyte, hemoglobin, hematocrit significantly increased in $75mJ/cm^2$ than control group and more $150mJ/cm^2$ ultraviolet irradiation group respectively. Also In blood gas tests, $PO_2$ significantly increased in $75mJ/cm^2$ and more $150mJ/cm^2$ group than control group. Whereas $PCO_2$ significantly decreased in $75mJ/cm^2$ and more $150mJ/cm^2$ group than control group (Duncan-Tukey test, P<0.05). In histological tests, control and $75mJ/cm^2$ group unchanged, but more $150mJ/cm^2$ group changed that it was cytolysis, cytotoxic effect, acanthosis, proliferation of keratinocyte, appearance of amorphous cell and pyknotic nucleus, production of sunburn cell. In conclusion, the present author results support the importance of the relation between NO effect and hematological, histological value by ultraviolet B irradiation.

• Geomechanics and Engineering
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• v.32 no.6
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• pp.627-637
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• 2023

Volleyball is an international sport with many fans. This sport has made significant progress in schools and clubs. Volleyball is suitable for all age groups and can be used in different environments. It has many social and physical benefits. During the game provides special physical training for the players and is considered one of the most exciting games. Another type of volleyball is beach volleyball, a beach sport and one of the Olympic sports held on the sand with the same rules as volleyball. This sport is usually played in coastal areas, especially with wide sandy beaches. Because this sport is played in open spaces, the players stay in this space for a long time and are exposed to dangerous ultraviolet radiation. It is a wavelength of light in the range of electromagnetic waves with a wavelength between 10 and 400 nm. This wavelength is shorter than visible light and more protracted than X-ray. Ultraviolet (UV) rays are naturally present in sunlight and include about 10% of all waves emitted from the sun's surface. Prolonged exposure to ultraviolet light causes acute and chronic damage to the skin and vision and even destroys the entire immune system. Different covers of the earth's surface reflect different amounts of UV rays. For example, snow cover, sand, and seawater surface reflect this radiation. Therefore, the health of volleyball players is in danger due to this harmful radiation. This work aims to introduce a type of clothing made of nanoparticles that can repel ultraviolet rays and protect beach volleyball players whose health is at risk from this radiation.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.143-146
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• 2005

Although many studies have been performed to elucidate the molecular consequences of ultraviolet irradiation, little is known about the effect of natural products. Ultraviolet irradiation is widely considered to be an environmental stress. Here we investigated the effect of 2',4',7-trihydroxyisoflavone on the regulation of MMP-1 and type 1 procollagen in Ultraviolet irradiation of cultured human dermal fibroblasts. Phytochemical investigation of the whole plants of Viola hondoensis led to the isolation of five flavonoids. The structures of these compounds were identified 2',4',5,7-tetrahydroxyisoflavone (1), 2',4',7-trihydroxyisoflavone (2), 4',7-dihydroxyflavone (3), isoorientin (4), and isovitexin (5) using spectroscopic analysis. Among these, 2',4',7-trihydroxyisoflavone reduced the expression of MMP-1 at the protein levels in a dose-dependent manner by ultraviolet irradiation. Taken together, our results suggest that 2',4',7-trihydroxyisoflavone an important role in the reduction of MMP-1 induction by ultraviolet irradiation.

• Journal of Environmental Science International
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• v.8 no.6
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• pp.725-730
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• 1999

The advanced oxidation process (AOP) using ozone combined with hydrogen peroxide and ultraviolet treatment were evaluated for biodegradable dissolved organic carbon (EDOC) formation and dissolved organic carbon (DOC) removal. Oxidation treatment were conducted alone or combination with ozone, hydrogen peroxide and ultraviolet processes. Ozone dosage of ozone process was varied from $0.5mg/l{\ell}\cdot}min$ to $5mg/{\ell}{\cdot}min$. Ozone/hydrogen peroxide process was done using $20mg/{\ell}{\cdot}min$ of hydrogen peroxide concentration. Ozone/ultraviolet process was irradiated with $12mW/cm^2$ of density and 254nm. Ozone dosage was varied from $0.5mg/{\ell}{\cdot}min$ to $5mg/{\ell}{\cdot}min$ at the ozone/hydrogen peroxide and ozone/ultraviolet processes too. Contact time of all the process was 20 minutes. Oxidation treatment were performed on microfiltration effluent samples. BDOC formation was reached to an optimum at ozone dosage of $1.5mg/{\ell}{\cdot}min$ in the ozone/hydrogen peroxide process and $1mg/{\ell}{\cdot}min$ in ozone/ultraviolet process, after which BDOC formation was decreased at higher ozone dosages. But BDOC formation was increased with ozone dosages increasing in ozone process. The efficiency of DOC removal was higher AOPs than ozone process. Ozone/ultraviolet proces was the highest for DOC removal efficiency in each process. THMFP. removal efficiency by ozone/ultraviolet process was higher than that by each of ozone process and ozone/hydrogen peroxide process.

• Archives of Pharmacal Research
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• v.27 no.10
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• pp.1060-1064
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• 2004

Although many studies have been performed to elucidate the molecular consequences of ultraviolet irradiation, little is known about the effect of natural products. Ultraviolet irradiation is widely considered to be an environmental stress. Here we investigated the effect of 3,23-dihydroxy- 20(29)-lupen-27-oic acid on the regulation of MMP-1 and type 1 procollagen in Ultraviolet irradiation of cultured old age human dermal fibroblasts. 3, 23-dihydroxy-20(29)-lupen-27- oic acid was isolated from Tiarella polyphylla D. Don (Saxifragaceae). Among them, 3, 23- dihydroxy-20(29)-lupen-27-oic acid induced the regulation of Type 1- procollagen and reduced the regulation of MMP-1 at the protein levels in a dose-dependent manner by ultraviolet irradiation. Taken together, our results suggest that 3, 23-dihydroxy-20(29)-lupen-27-oic acid plays an important role in the induction of Type 1-procollagen and reduction of MMP-1 by ultraviolet irradiation in old age human dermal fibroblasts.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.4
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• pp.241-246
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• 2016

ZnO thin films have wide application areas due to its versatile properties as transparent conductors, wide-bandgap n-type semiconductors, gas sensor materials, and etc. We have performed a systematic investigation on ultraviolet-assisted CVD (chemical vapor deposition) method. Ultraviolet irradiation during the deposition of ZnO causes chemical reduction on the growing surface; which results in the reduction of the deposition rate, increase in the surface roughness, and decrease of the electrical resistivity. These effects produce larger characteristic variation with various deposition conditions in terms of surface morphology and optical/electrical properties compared to normal CVD deposited ZnO thin films. This versatile controllability of ultraviolet-assisted CVD can provide a larger processing options in the fabrication of nano-structured materials and flexible device applications.