• Journal of Photoscience
• /
• v.6 no.1
• /
• pp.5-6
• /
• 1999

Solar ultraviolet-B (UV-B) irradiances incident on a horizantal surface at Taegu of Korea during 1995-1998 were calculated with 5 min averges of measuremets taken every 30 seconds by a broadband UV-B sensor. The maximum and minimum of monthly averages of daily UV-B dose were 15.89 KJ m-2 day-1 in April and 3.91KJm-2 day-1 on May 22, 1998 and 1.230W m-2 at 12 : 45, July 13, 1998, respectively. Increasing trend in annual maximum of instantaneous UV-B radiation was averaged to 12.0% per year during 1995-1998 of observation period.

• Biomolecules & Therapeutics
• /
• v.22 no.1
• /
• pp.35-40
• /
• 2014

Resveratrol is a polyphenolic compound found in various natural products such as grapes and berries and possesses anti-cancer, anti-hyperlipidemia, and anti-aging properties. Recently, it has been reported that resveratrol inhibits ${\alpha}$-melanocyte-stimulating hormone signaling, viability, and migration in melanoma cells. However, these effects have not been confirmed in vivo, specifically brownish guinea pigs. To evaluate the potential of resveratrol as a regulator of melanin for hyperpigmentation therapy, the influence of resveratrol on pigmentation was investigated by ultraviolet B-induced hyperpigmentation in brownish guinea pig skin. We found that resveratrol reduced the expression of melanogenesis-related proteins tyrosinase, tyrosinase-related proteins 1 and 2, and microphthalmia-associated transcription factor in melanoma cells. Furthermore, topical application of resveratrol was demonstrated to significantly decrease hyperpigmentation on ultraviolet B-stimulated guinea pig skin in vivo. Based on our histological data, resveratrol inhibits melanin synthesis via a reduction in tyrosinase-related protein 2 among the melanogenic enzymes. This study is the first to provide evidence supporting resveratrol as a depigmentation agent, along with further clinical investigation of resveratrol in ultraviolet B-induced skin disorders such as hyperpigmentation and skin photoaging.

• Textile Coloration and Finishing
• /
• v.10 no.4
• /
• pp.53-61
• /
• 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 Korean Journal of Ecology
• /
• v.24 no.2
• /
• pp.117-119
• /
• 2001

Solar ultraviolet-B (UV-B) irradiances incident on a horizontal surface at Taegu, Korea during 1996-1998 were calculated with 5 minute averages of measurements taken every 30 seconds by a broadband UV-B sensor. The average, maximum and minimum of daily UV-B dose were 11.31, 22.04 and 3.20kJ m$^{-2}$ day$^{-1}$ , respectively, for the measuring period. Variations in stratospheric ozone concentration measured from space explain 85% of changes in the daily UV-B dose. It was expected that decrease of 50 Du in stratospheric ozone cause increase of 24.1% in daily UV-B dose in this study.

• Journal of Photoscience
• /
• v.9 no.2
• /
• pp.154-157
• /
• 2002

Direct, continuous, and accurate measurements of solar ultraviolet irradiance (290-400 nm: UVR) have been carried out since 1990, by using both band-spectral ultraviolet-B (290-320 nm: UV-B) and ultraviolet-A (320-400 nm: UV-A) radiometers at Tokai University in Hiratsuka, Japan (35$^{\circ}$N, 139$^{\circ}$E). From our observations, the following findings are provided: 1) an increasing trend in solar UV -B from Oct. 1990 to Sept. 2000; 2) a regional comparison of solar UVR in Japan; 3) the distinct characteristics of UV-B and UV-A irradiance, such as diffuse property, daily and seasonal variation; and 4) human body protection against solar UVR. An increasing 10-year trend in global solar UV - B in Hiratsuka corresponded to a decrease in the total ozone amount measured at Tsukuba (36$^{\circ}$N, 140$^{\circ}$E), giving supportive evidence for a direct link between these two parameters. Furthermore, a strong correlation was found between solar UV-B and total ozone amount from results of UVR measurements at four Tokai University monitoring stations dispersed throughout Japan. Additional results revealed different diffuse properties in global solar UV and in global solar total (300-3000 nm: Total) irradiances. For example, in the global UVR, the diffuse component was dominant: about 80 % independent of weather, with more than 60 % of global UV-B, and more than 50% of global UV-A with even a cloudless clear sky. On the other hand, the portion of the diffuse in the global total irradiance was very low, less than 10 % on a cloudless clear day. Daily and seasonal variations of UV -B and UV -A irradiances were found to be quite different, because of the marked dependence of UV -B irradiance on the atmospheric ozone amount. Moreover, UV -B irradiance showed large daily and seasonal variations: the ratio between maximum and minimum irradiances was more than 5. In contrast, the variation in UV-A was small: the ratio between maximum and minimum was less than 2. Three important facts are proposed concerning solar UVR protection of the human body: 1) the personal minimal erythema dose (MED); 2) gender based difference in MED values; and 3) proper colors for UVR protective clothing.

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

• Journal of the Society of Disaster Information
• /
• v.17 no.2
• /
• pp.195-205
• /
• 2021

Purpose: The ultraviolet reflectance and transmittance of coastal building materials are one of the important factors of ultraviolet radiation in and out of coastal building. In this research, the ultraviolet spectral reflectance of many kinds of building materials was measured. Also, the relationships with the lightness, roughness, and chromaticity, which are surface characteristics, were reviewed and suggested. Method: In this study, according to the CIE classification, the ultraviolet region was defined as short-wavelength region UV-C(10nm~280nm), medium-wavelength region UV-B (280-315 nm), and long-wavelength region UV-A (315-400nm), and the visible light region was defined as (400nm~780nm). Spectrophotometer was used to continuously measure the reflectance from the ultraviolet region to the visible light region. Results: From the measurement results, the ultraviolet reflectance on Wood was shown to be about Visible 55-68%, UV-A^* 7-12%, and UV-B 4-5%. Wall tiles are about Visible18-40%, UV-A^* 8-20%, and UV-B^* 7-8%. That on concrete was shown to be about Visible 37%, UV-A^* 28%, and UV-B^*19%. Conclusion: The ultraviolet reflectance can be estimated by visible reflectance. Also, it is important to select a variety of materials according to the application when blocking UV.

• 보존과학연구
• /
• s.29
• /
• pp.65-90
• /
• 2008

This study examines the status and the physical features of Paraloid B-72 layers with examination of microstructure and analysis of organic matters. Paraloid B-72 layers were coated on samples from the colour layer of outer wall painting in Mireuk hall in Geumsan temple. On the basis of the previous examination result, it has made the samples which are similar to outer wall in Mireuk hall in Geumsan temple. The samples can be divided into two, one; 5% Paraloid B-72 coating and another is without coating. Then samples have been experimented under the compulsive environments of infrared radiation and immersion, thereafter compared the results of the damages and physical features between two samples. As a result of the comparison, the sample with Paraloid B-72 had more serious cracks, exfoliations and peeling layers than that of without Paraloid B-72. Otherwise, in the examination of ultraviolet radiation, the sample with Paraloid B-72 coating showed weaker physical properties, less density in structure of colour layer and less hardness in surface of colour layer than the sample without coating. The percentage of moisture content after the ultraviolet radiation was higher in the sample without Paraloid B-72 than the sample with Paraloid B-72 coating. Observing the conditions before the ultraviolet radiation, the sample with Paraloid B-72 coating demonstrated lower rate in moisture evaporation rate than the sample without Paraloid B-72. As a consequence, in examination of this samples, the change of physical features are increased in the sample with Paraloid B-72 coating than that without Paraloid B-72 when compulsive environment of heat, moisture and ultraviolet rays for a short term are imposed.

• Journal of Bio-Environment Control
• /
• v.10 no.3
• /
• pp.197-206
• /
• 2001

The depletion of stratospheric ozone is regarded as a major environmental threat to plant growth and ecosystem. The ozone depletion has caused plants to be exposed to an increased penetration of solar ultraviolet-B (UV-B) radiation in the 280-320 nm wavelength range. Enhanced UV-B radiation may have influence on plants biological functions in many aspects including inhibition of photosynthesis, DNA damage, lipid peroxidation, changes in morphology, phenology, and biomass accumulation. To cope with the damage by UV radiation, plants have evolved to have protective mechanisms, such as photorepair, accumulation of UV-absorbing compounds, leaf thickening and activation of antioxidative enzymes. The objective of this review is to address the effects of enhanced UV-B on plant growth, UV-B action mechanisms and protection and protection mechanisms in plants.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2011.06a
• /
• pp.1115-1116
• /
• 2011