• Title/Summary/Keyword: Ultraviolet Rays

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Performance Test and Design of Distribution FRP Pole (배전용 FRP 전주 설계 및 성능시험)

  • 한동희;조한구;박기호;송일근;이웅선
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.295-298
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    • 2001
  • This paper presents mechanical properties and weatherability of FRP pole used for a distribution line about high strength and good insulation properties. The experiment strength obtained in cantilever beam test are comparable to ES standards. The environmental factors, such as elevated temperatures, high humidity, and corrosive fluids, and ultraviolet(UV) rays, influence on the performance of Polymeric matrix composite.

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ALD-based Functional Bragg Reflector Structure to Block Harmful Ultraviolet Rays that Affect the Reliability of Organic Devices (유기소자의 신뢰성에 영향을 주는 유해 자외선을 차단하기 위한 ALD기반 기능성 브래그반사경 구조)

  • Hyeun Woo Kim;Hyeong Jun Lee;Seungmi Jang;Hyeongjun Yun;Dokyun Lee;Yongmin Lee;Sangyeon Park;Jihoon Jung;Seokjun Lim;Jeong Hyun Kwon
    • Journal of the Semiconductor & Display Technology
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    • v.22 no.4
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    • pp.103-107
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    • 2023
  • To solve the reliability problem of organic devices that are often used outdoors, multifunctional gas barriers that block reactive gases such as moisture and oxygen and reflect harmful light such as ultraviolet rays are needed. In this study, ALD nanolaminate-based optically functional n-DBR was developed to overcome the poor gas permeability of polymer substrates and protect organic devices from harmful light. n-DBR not only achieved a WVTR of 8.76 × 10-6 g·m-2·day-1, but also showed a visible light transmittance of 94.3% and an ultraviolet ray blocking ability of 2.67%. In particular, n-DBR based on a nanolaminate structure maintained its permeability characteristics even in a high temperature and high humidity environment despite being used as a layer of Al2O3. This functional barrier Structure can not only be used as a functional encapsulation barrier for the reliability of organic devices, but can also be used as a tinting film for vehicles.

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A Study on the Daylighting Control Method in a Storage Room (장경각의 일조환경 평가에 관한 연구)

  • Lee, Soo-Min
    • Journal of The Korean Digital Architecture Interior Association
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    • v.12 no.1
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    • pp.45-51
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    • 2012
  • To see sunlight condition around in storage room, this study analyzers the scope both of sunlight and of the shade of sun into upper and lower window according to seasons. For this, this study investigates sun's seasonal changes, its effect of sunlight and notes antinomic conditions for ventilation and draft performance. In this, Architects of Jangkyunggak tride to block discoloration and fading due to ultraviolet rays and visible rays and block deterioration drying of the surface of Kyung-Pan due to infrared rays by oppressing sunlight flowing by means of narrowing the area of the upper window at front face that has a direct influence of Pan-Ga to avoid the exposure to direct sunlight.

Laboratory Evaluation of Polysulfide Epoxy Overlay Material for Bridge Deck (교면포장용 폴리설파이드 에폭시재료의 실내물성 평가)

  • Kim, Jun-Hyung;Suh, Young-Chan
    • International Journal of Highway Engineering
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    • v.13 no.2
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    • pp.159-166
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    • 2011
  • This research was performed to evaluate physical properties of polysulfide epoxy overlay material for bridge deck as part of a review for possibility of domestic application of polymer concrete for bridge deck pavement. In order to evaluate strength characteristics, compressive strength, flexural strength and bond strength were tested, and, for durability characteristics, chloride ion penetration resistance and freeze/thaw resistance were tested along with ultraviolet rays impact evaluation. The tests showed that the results met the criteria suggested by the American Concrete Institute in terms of compressive strength, flexural strength and bond strength. However, in terms of the strengths measured at various test temperatures, it was found that the epoxy material was highly dependent on temperature, and, therefore, this should be considered at the time of domestic application of the epoxy material later. Deflection characteristics was checked through flexural strength test and it was found that bridge deck pavement using the epoxy material was excellent compared to bridge deck pavement using asphalt. Furthermore, the results of chloride ion penetration resistance test and freeze/thaw resistance test were also excellent. In the evaluation of ultraviolet rays impact on epoxy slurry mixture, reduction of strain was noticed with increased strength, but the deflection characteristics after exposure to ultraviolet rays was better than the existing acryl polymer concrete. Therefore, it is concluded from the research that the polysulfide epoxy overlay material has the physical properties that are appropriate to pavement of bridge deck.

A Test to Compare the Water Resistance Sun Protection Factor of General Water, Artificial Seawater, and Natural Seawater of Sunscreen (자외선 차단제의 일반 물, 인공 해수, 자연 해수의 내수성 차단지수를 비교하기 위한 시험)

  • Hyoung Hoon Hwang;Eun Young Kang;Su Yeong Kim;Hui Jeong Jung;Jun Seong Yang;Won Kyu Hong;Hong Suk Kim
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.49 no.4
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    • pp.349-354
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    • 2023
  • Sunscreen is a product that protects against ultraviolet rays by blocking and scattering ultraviolet rays, and has now become a daily necessity beyond cosmetics. Applying sunscreen is a common and easy way to prevent skin damage caused by ultraviolet rays. Due to its significance, the evaluation of sunscreen has evolved since its regulation by the FDA in 1978, progressing to standardized methods established by ISO. Additionally, to assess the loss of sunscreen due to activities such as water exposure or sweating, the Ministry of Food and Drug Safety in Korea and ISO have established protocols for evaluating the water-resistant sun protection factor (SPF). However, existing evaluations of water resistance have been mainly confined to test methods involving plain water, and methods accounting for the impact of seawater during activities like beach leisure, sports, and recreation are yet to be established. Based on the existing guidelines for testing the water-resistant UV protection index, this study compared the water-resistant UV protection index in water, artificial seawater (salt water) and natural seawater (sea water) to evaluate the UV protection index in real-world situations such as marine leisure, sports, and leisure activities. Through these results, we were able to compare the differences between water resistance sun protection index tests in ordinary water, artificial seawater, and natural seawater, and suggest a method for water resistance sun protection index tests using natural seawater.

The analysis of the Effect the Minute Quantities of Infrared Rays that Were not Filtered by IR Cut-Off Filter has on Digital Images (IR Cut-Off Filter가 차단하지 못한 미량의 적외선이 디지털화상에 미치는 영향 분석)

  • Lee, Yong-Hwan;Park, Se-Won;Hong, Jung-Eui
    • The Journal of the Korea Contents Association
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    • v.11 no.5
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    • pp.205-215
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    • 2011
  • Films are sensitive to ultraviolet rays and in contrast, digital camera sensors are extremely sensitive to infrared rays due to the differences in spectral characteristics. As a result, all digital cameras that use CCD or CMOS are equipped with IR Cut-Off Filter on the overall sensor. Complete block out of infrared rays is ideal, but the actual experiment results showed that infrared rays were not being blocked out completely. Infrared permeability was also different for each camera. Therefore, this study aims to analyze the effect of the minute quantities of infrared rays, which get transmitted due to mechanical properties of IR Cut-Off Filters that are installed on digital cameras, on digital picture images. The results obtained by carrying out a comparative analysis of a UV Filter (infrared transmitting state) and a UV-IR Filter (infrared blocked out state) are as follows. It was confirmed that the minute quantities of infrared rays do affect dynamic range and resolution to some extent, despite the little or no difference in noise and color reproduction.

Protective effect of Thymus quinquecostatus extracts UVB-induced matrix metalloproteinase-1 via suppressing MAPKs phosphorylation in human keratinocyte (사람의 각질세포에서 UVB 유도에 따른 MMP-1의 발현 조절과 MAPKs 인산화에 타임 추출물이 미치는 효과)

  • Jung, Hana;Jeong, Hyun Ju;Shin, Kyounghee;Kim, Yung Sun;Moon, Jae Heon;Lee, Tae Hoon
    • Journal of Applied Biological Chemistry
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    • v.61 no.4
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    • pp.417-421
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    • 2018
  • Ultraviolet rays are electromagnetic waves with a shorter wavelength than visible light, and ultraviolet rays that pass through the ozone layer are the main cause of skin aging. Chronic exposure of skin tissue to ultraviolet light activates the Mitogen-activated Protein Kinases (MAPKs) signaling pathways in human keratinocytes, resulting in increased production of matrix metalloproteinases (MMPs). In this study, we investigated the herbal extracts from Jeju Island on the anti-aging effect in human keratinocytes (HaCaTs) by ultraviolet stimulation. We examined that herb extract from Jeju Island were decreased in anti-aging activity on measuring the level of MMP-1 gene and protein expression in ultraviolet-induced keratinocytes. As a result, it was confirmed that Thymus quinquecostatus extract (TQE) significantly reduced the expression of MMP-1 in a dose-dependent manner by UV irradiated HaCaTs. According to our data, TQE significantly attenuated UV-induced phosphorylation of the MAPKs signaling elements ERK1/2, JNK1/2 and p38 proteins. These results suggest that the MAPKs pathway may contribute to the inhibitory effect of TQE on UV-induced MMP-1 production in human keratinocytes. Our results suggest that TQE may be a protective agent against skin aging by preventing UV-induced MMP-1 production.

Design of 8-bit Single Slope ADC for Signal Processing of Multiple Image Sensors (다중 이미지 센서의 신호처리를 위한 8-bit Single Slope ADC 설계)

  • Lee, Jong-Cheol;Lee, Sang-Hoon;Kim, Jin-Tae;Park, Jae-Roul;Shin, Jang-Kyoo;Choi, Pyung
    • Journal of Sensor Science and Technology
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    • v.24 no.4
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    • pp.252-257
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    • 2015
  • This paper proposes a single slope A/D converter (SSADC) that is possible to process the signal of the ultraviolet, visible and infrared rays with a single chip. And the proposed SSADC is a type of single channel ADC. In the conventional SSADC, it is possible to process the only one signal with a kind of the sensor because the speed of the operating frequency and the slope of ramp signal generated by the ramp generator are fixed. In order to improve the disadvantages, a ramp generator which has variable slope in ramp function is designed and $3{\times}1$ MUX(multiplexer) is adopted so that we can change the speed of the operating frequency and the slope of ramp signal. Therefore, the multiple signal processing of the wanted sensors can be possible. The designed circuit is layout by the $0.35-{\mu}m$ CMOS 2-poly 4-metal technology process and is checked through DRC and LVS tools.

Remote Measurement of Ultraviolet Reflections for the Guidelines for Leisure Tourism Activities on the Adjacent Coast of the Demilitarized Zone Peace Life Belt (비무장지대 평화생명벨트 인접해안에서의 레저관광활동 가이드라인을 위한 자외선 반사량 원격측정)

  • Uh, Je-Sun;Choi, chul-Jae
    • The Journal of the Korea institute of electronic communication sciences
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    • v.17 no.3
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    • pp.499-506
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    • 2022
  • With the construction of the northern line of the East Sea in 2021, expectations for peaceful use of the Demilitarized Zone (DMZ) are rising. Accordingly, it is necessary to prepare for leisure tourism activities at nearby beaches using the Demilitarized Zone as a security ecological tourism. However, despite the increase in the amount of ultraviolet rays on the surface due to the destruction of the ozone layer, there are no guidelines for UV exposure. In this paper, the amount of ultraviolet reflection on the coast adjacent to the DMZ using remote exploration was measured and analyzed. It is hoped that the presented results will be used as basic data to prepare UV guidelines for leisure tourism activities in nearby areas.

A Study on the Treatment of Dyeing Wastewater Using TiO2/UV (TiO2/UV 산화기술을 이용한 염색폐수처리에 관한 연구)

  • Kim, Jong-kyu;Chung, Ho-jin
    • Journal of Korean Society of Water and Wastewater
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    • v.18 no.3
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    • pp.392-400
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    • 2004
  • This research uses the $TiO_2$/UV process to verify the most suitable condition and possibility to dispose dyeing wastewater that contains pigment and a large amount of pollutants. For this, this research has enforced experiments that compare photo adsorption, photolysis, and photo catalyst oxidation reaction, and also evaluated and analyzed the change of pH and $TiO_2$ dosage, irradiation rates of ultraviolet rays and the dosage change and injection method of $H_2O_2$. According to the results of the dyeing wastewater experiment of storehouse catalyst that uses the new form of $TiO_2$, the photo catalyst oxidation reaction proved to be more effective than photo adsorption and photolysis; 35%, 21% in the case of $TCOD_{cr}$ and 39%, 28% in the case of chromaticity. Taking into consideration the reaction time, amount of photo catalyst reaction and irradiation amount of ultraviolet rays, the decomposition efficiency of pH change proved to be most effective at pH 4. On the whole, the acidity area proved to be effective in dyeing water exclusion than neutral and alkalinity areas. Having evaluated the influence of $TiO_2$ dosage, not only does the decomposition efficiency continuously improve as the $TiO_2$ dosage increases but the shielding effect does not occur also when the $TiO_2$ is at a fixed state. The influence of ultraviolet irradiation amount concluded in the result that as the ultraviolet irradiation amount increases the decomposition efficiency continually increased, but in the case of chromaticity when the irradiation amount was higher than 37.8mW/cm2 the removal efficiency is slowed remarkably. The influence of $H_2O_2$ dosage evaluation reached the results that although the decomposition efficiency increases with the increase of $H_2O_2$ dosage, when above 150mg (total dosage: 1200mg) $H_2O_2$ consumes OH radical itself and reduces the decomposition efficiency. Also in the case of the $H_2O_2$ injection method rather than injecting in the whole amount of $H_2O_2$ (1200mg) needed at the beginning all at once, injecting divided quantities of $H_2O_2$ whenever the electric current density falls below 10mgfl reduces the wases of OH radical due to an excess of $H_2O_2$ and in tum heightens the decomposition efficiency.