• 한국염색가공학회지
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• 제10권4호
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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.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1992년도 한국우주과학회보 제1권1호
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• pp.14-14
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• 1992

The IUE archival spectra of VV Cephei were collected to investigate the eclipse nature in the ultraviolet. The temperature of the B star has been determined, as approximately30,OOOK, based en the flux distributions durstributions during egress, Light curves of VV Cephei were reduced from the spectrophotometry of the IUE archival spectra. Three light curves at the center wavelengths of 2350A,2550A and :!850A have been analyzed by the modified Wilson and Oevinney light curve program. the radii of the B star and M star were deduced to 0.05 and 0.22 of uint separation, respectively. The UV light curves show anevidence that the light was attenuated by the highly opaque atmosphere of the M star

• Journal of Astronomy and Space Sciences
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• 제9권1호
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• pp.111-119
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• 1992

The IUE archival spectra of VV Cephei were collected to investigate the eclipse nature in the ultraviolet. The temperature of the B star has been determined, as approximately 30000K, based on the flux distributions during egress. Light curves of VV Cephei were reduced from the spectrophotometry of the IUE archival spectra. Three light curves at the center wavelengths of 2350 ${\AA}$, 2550 ${\AA}$ and 2850 ${\AA}$ have been analyzed by the modified Wilson and Devinney light curve program. The radii of the B star and M star were deduced to 0.05 and 0.22 of unit separation, respectively. The UV light curves show an evidence that the light was attenuated by the highly opaque atmosphere of the M star.

• 한국재난정보학회 논문집
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• 제17권2호
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• pp.195-205
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• 2021

연구목적: 연안건축 재료의 자외선 반사율과 투과율은 건물의 자외선 방출 및 방출의 주요 요인 중 하나이다. 이 연구에서는 건축 자재의 여러 종류의 자외선 스펙트럼 반사율이 측정되었으며 또한 표면 특성 중에 하나인 명도, 거칠기 및 색도와의 관계에 대해서도 검토 및 제안했다. 연구방법: 본 연구에서는 CIE 분류에 의거하여 자외선영역은 단파장 UV-C (10nm~280nm), 중파장 영역 UV-B (280-315 nm), 장파장 영역 UV-A (315-400nm), 가시광선 영역 (400nm~780nm)으로 정했으며, 연속적으로 측정하기 위하여 분광 광도계를 사용했다. 연구결과: 나무의 경우 반사율은 가시광선역 55-68 %, UV-A ^* 7-12 %, UV-B^* 4-5 %로 나타났다. 벽타일은 가시광선역 18-40 %, UV-A^* 8-20 %, UV-B^* 7-8 % 로 나타났으며, 콘크리트는 가사광선역 37 %, UV-A^* 28 %, UV-B^* 19 %로 나타났다. 결론: 가시광선 반사율에 의해 자외선 반사율을 추정 할 수 있으며, 또한 자외선 차단을 할 때에는 용도에 따라 다양한 재료를 선택하는 것이 중요하다.

• 대한물리치료과학회지
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• 제6권3호
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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.

• 한국의류산업학회지
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• 제10권2호
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• pp.249-253
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• 2008

The purpose of this study was to investigate the properties changes of wool fabrics dyed with safflower red and yellow colorants under Ultraviolet(UV)-light. For this purpose, the wool fabrics dyed with safflower red and yellow colorants were compared with each other after uv-light exposure in terms of K/S value, color changes(${\Delta}E$), morphology, and strength retention. K/S value rapidly decreased with increasing exposure time, but K/S value of the samples dyed with safflower yellow colorants decreased less than that of the samples dyed with safflower red colorants. In color changes, as increasing exposure time, $L^*$ and $b^*$ increased, $a^*$ decreased, and thereby ${\Delta}E$ increased in the samples dyed with safflower red colorants, $L^*$ increased, $a^*$ and $b^*$ decreased, and so ${\Delta}E$ increased in the samples dyed with safflower yellow colorants, indicating fading away by uv-light and changes of hue, value and chroma value. But the color change of samples dyed with safflower yellow colorants was less than that of samples dyed with safflower red colorants. SEM pictures showed a severe degradation by uv exposure, regardless of colorants type. Tensile strength slowly decreased until 14 days, and rapidly decreased until 21 days and slowly decreased. Strength retention of the samples dyed with safflower yellow colorants was higher than that of the samples dyed with safflower red colorants.

• 한국세라믹학회지
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• 제47권2호
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• pp.169-176
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• 2010

The Fe-treated CNT/$TiO_2$ photocatalysts mixed with anatase and rutile phase have been developed for the decomposition of non-biodegradable different organic dyes like methylene blue (MB), rhodamine B (Rh.B), and methyl orange (MO) in two conditions as ultraviolet and visible light respectively. The results indicate that all the Fe-CNT/$TiO_2$ composites proved to be more efficient photocatalysts since degradation of MB at higher reaction rates, tthe decomposition rate of different dyes increases with an increase of $Fe^{3+}$ concentration in composites the highest rate of decomposition of different dyes was noted under UV irradiation. These results can indicate that the large CNT network is facilitate the electron transfer and strongly adsorb dye molecules on the texted photocatalysts, iron is reactive in the photo-Fenton process resulting in high production of OH radicals and also high activity of the photocatalyst. And Fe particles can generate more photoinduced electrons to conduction band of $TiO_2$ under visible light irradiation. The composites of Fe-CNT/$TiO_2$ photocatalysts synthesized by a sol-gel method were characterized by BET, TEM, SEM, XRD and EDX.

• 한국대기환경학회지
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• 제22권2호
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• pp.223-233
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• 2006

We analyzed the monthly and seasonal mean of the daily Erythemal Ultraviolet-B (EUV-B, $280{\sim}320nm$) irradiance operating in Pohang, Anmyeon, Gosan, Mokpo and Kangnung with UV-Biometer (Solar Light Co., Model No. 501) at clear-sky noon during the period from 1999 to 2004. Also, we investigated the seasonal and regional characteristics for the UV index over the Korean Peninsula. The daily maximum occurred near solar southing time and the highest monthly accumulated EUV-B irradiance appeared in July and August at each regional observatory. The monthly mean value of the clear-sky EUV-B irradiance in Pohang, Anmyeon, Gosan, Mokpo and Kangnung showed 196.6, 161.8, 221.9, $171.5mWm^{-2}\;and\;179.7mWm^{-2}$ near noon in July respectively. The annual mean value of the daily accumulated EUV-B irradiance in Pohang, Anmyeon, Gosan, Mokpo and Kangnung were 1.8, 2.1, 2.2, $1.8kJm^{-2}\;and\;1.5kJm^{-2}$ respectively. The UV Index (UVI) showed above UVI 7(High) more than 90 days during one year over the Korean Peninsula.

• 한국환경농학회지
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• 제26권3호
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• pp.239-245
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• 2007

The effect of ultraviolet-B (UV-B) radiation on photosynthesis was studied by the simultaneous measurements of $O_2$ evolution and chlorophyll (Chl) fluorescence in tobacco leaves. When the tobacco leaves were teated with UV-B (1 $W{\cdot}m^{-2}$), the maximal photosynthetic $O_2$, evolution (Pmax; 4.60 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) at 200 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) was decreased with increasing time of UV-B treatment showing 80% decline after 4 h treatment. Chl fluorescence parameters were also affected by ultraviolet-B. Fo was increased while both Fm and Fv were decreased, resulted in the decreased of photochemical efficiency of PSII (Fv/Fm). Non-radiative dissipation of absorbed light as heat as estimated as NPQ (Fm/Fm' - 1) was also decreased with increasing time of UV-B treatment while the extent of photochemical quenching (qP) was not changed. Thus, the ratio of (1-qP)/NPQ parameter was also increased with increasing time of UV-B treatment indicating PSII is under the threat of photoinhibition. The result indicate that UV-B primarily decreases the capacity to dissipate excitation energy by trans-thylakoid pH, which in turn inhibits PSII activity.

• 천문학회보
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• 제44권2호
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• pp.48.2-48.2
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• 2019

Light from universe is absorbed, scattered, and re-released by interstellar dust before it reaches us. Therefore, accurate correction of the observed light requires not only spatial distribution of interstellar dust, but also information on absorption and scattering for each wavelength. Far-ultraviolet (FUV) light is mainly produced by bright, young O-type and some B-type stars, but it is also observed in interstellar space without these stars. Called FUV Galactic light (DGL), these lights are mostly known as starlight scattered by interstellar dust. With the recent release of GAIA DR2, not only accurate distance information of stars in our Galaxy, but also accurate three-dimensional distribution maps of interstellar dust of our Galaxy were produced. Based on this, we performed 3-dimensional Monte Carlo dust scattering radiative transfer simulations for FUV light to obtain dust scattered FUV images and compared them with the observed FUV image obtained by FIMS and GALEX. From this, we find the scattering properties of interstellar dust in our Galaxy and suggest the intensity of extragalactic background light. These results are expected to aid in the study of chemical composition, size distribution, shape, and alignment of interstellar dust in our Galaxy.