• Title/Summary/Keyword: ultraviolet (UV)

Search Result 1,212, Processing Time 0.029 seconds

Suppression of Powdery Mildew and Two-Spotted Spider Mite by UV-B Radiation and Mulching Type of Strawberry Cultivation in the Greenhouse (딸기 시설재배에서 UV-B 램프와 멀칭 종류에 따른 흰가루병과 점박이응애 억제)

  • Nam, Myeong Hyeon;Kim, Hyun Sook;Lee, InHa;Seo, Jeong Hak;Lee, Byung Joo
    • Research in Plant Disease
    • /
    • v.28 no.2
    • /
    • pp.61-68
    • /
    • 2022
  • Powdery mildew and two-spotted spider mite are detrimental to strawberry plants and are controlled with traditional pesticides. To accommodate consumer demand, eco-friendly methods of pest control are required. Strawberries were cultivated (in soil and in a hydroponic system) for two years, and ultraviolet B (UV-B) irradiation was used as an alternative pest control during the harvesting season. Three varieties were grown (Seolhyang, Kingsberry, and Durihyang), and four UV-B lamp/mulch (black, green, and light reflection sheet [LRS]) combinations were used during harvesting: UV-B+black or green mulch, UV-B+black or green+LRS, no UV-B+black or green, and no UV-B+black or green+LRS. In all varieties, powdery mildew was 65% more controlled when UV-B irradiation was used. The adult two-spotted spider mite density was lowest in the UV-B lamp+black or green+LRS treatments. Therefore, UV-B irradiation during the strawberry harvesting season could effectively control powdery mildew and two-spotted spider mite with little side effect on the plants.

Effect of UV Radiation on Early Growth of Korean Rice Cultivars(Oryza sativa L.)

  • Choi, Kwan-Sam;In, Jun-Gyo;Kang, Si-Yong;Bae, Chang-Hyu;Lee, Hyo-Yeon
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.44 no.3
    • /
    • pp.296-301
    • /
    • 1999
  • The concerns on the crop damage by ultraviolet (UV) radiations is increasing owing to the decrease of their absorbing stratospheric ozone in the tropospheric. Cultivar differences on early growth of UV radiation among five Korean rice cultivars, four japonica types and one Tongil type (indica-japonica cross hybrid), were studied. Pot-seeded rice plants were grown under four different radiation conditions, i.e., visible radiation only, visible radiation with supplemented with high or low dose of UV-B (280~320 nm in wavelength) and UV-C (less than 280 nm in wavelength). The inhibitory degree on plant height, shoot and root weight and length of leaf blade and leaf sheath were determined at 40 days after seeding. UV-C showed the most severe inhibitory effect on the degree of biomass gain and leaf growth in most cultivars examined, followed by high UV-B and low UV-B. Among the cultivars used, the Kuemobyeo was the most sensitive cultivar and had not repair or showed resistance ability to continued irradiation of UV radiation. However, Janganbyeo and Jaekeon showed different responses that the elongation of leaf blades was promoted on 2nd and 3rd leaves and inhibited on 4th and 5th leaves but this inhibitory degree was reduced on 6 th and 7th leaves. Such tendency on leaf growth means that both cultivars had low sensitivity and most resistant ability to continued irradiation of UV radiation. While Tongil showed different response to enhanced UV radiation, ie., low UV-B promoted leaf growth but the inhibitory was severely increased by continued irradiation of high UV-B and UV-C, which means that Tongil had high threshold of UV radiation for response as an inhibitory light of plant growth. The results of this study indicate that the differences on sensitivity or resistant to the effects of UV radiation were existed among Korean rice cultivars.

  • PDF

A Study on the UV-cut Properties of Cotton Fabrics Treated with UV-absorber (자외선 흡수제 처리 면직물의 소비성능 개선(제1보) - 자외선 차단성능에 관한 연구 -)

  • 강미정;권영아
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.25 no.5
    • /
    • pp.925-932
    • /
    • 2001
  • The influence of ultraviolet(UV)-ray in sun light on human skin has been noted. Textiles can provide protection against harmful UV-radiation. Normally UV-absorbing finishes are used to get better protection. The purpose of this study is to evaluate the UV-cut properties of cotton fabrics treated with UV-absorber. 2,2-dihydroxy-4,4-dimethoxbenzophenone, as UV-absorber was applied to 100% cotton fabric. Reagents added in finishing solution were Triton X-100, polyethylene glycol 400, and $MgCl_2{\cdot}6H_2O$, and C.I. Direct Red 81. Both untreated and treated cotton fabrics were exposed to a xenon arc lamp for 20 and 80 hours. UV absorption spectra of finishing solutions and UV transmission spectra of fabrics were measured by the UV/VIS spectrophotometer. The results of this study can be summarized as follows. The results of this study can be summarized as follows. Absorption and the related transmission spectra were modified in a controlled way with UV-absorber. Absorption effect of UV-absorber was improved by adding Triton X-100, PEG 400, and $MgCl_2{\cdot}6H_2O$ in finishing solution. The UV absorption of finishing solution was in the following order: U/D/T/P/M>D/T/P/M> D/T> D/P, D>U/T/P/M>U/T>T/P/M>T. The UV transmittance of cotton fabrics was remarkably decreased by the application of UV-absorber and additives. The UV-cut properties were most improved by the application of U/D/T/P/M.

  • PDF

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
    • /
    • v.61 no.4
    • /
    • pp.417-421
    • /
    • 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.

Study on the Physicochemical Change of Human Hair Shaft Following Radiation with Ultraviolet (자외선 조사에 따른 모발의 물리화학적 변화에 관한 연구)

  • Chang, Byung-Soo;Na, Su-Kyong;Lee, Gui-Yeong
    • Applied Microscopy
    • /
    • v.36 no.2
    • /
    • pp.109-118
    • /
    • 2006
  • The physicochemical properties of damaged hair by irradiation of ultraviolet-B (UV-B) have been investigated by using transmission electron microscope and scanning electron microscope. The range of irradiation of hair irradiated for expectative 6 hours, 12 hours, 24 hours and 48 hours with stimulated ultraviolet ray. The treated hairs showed characteristic morphological damage pattern in the cornified cell of matrix and the cuticle following time past. The various sized vacuoles in the endocuticle of the cuticular cells was formed. The statistically significant differences in diameter of cuticular cell were observed in terms of tranverse swelling by formation of vacuoles. The hair cortex and matrix undergo long term exposure to UV-B radiation. The macrofibrils of cortex appeared to be affected most by UV-B, although the morphology and volume of melanin granule was not changed. The physicochemical destruction of hair matrix and cuticular cells is largely accelerated by long term irradiation of UV-B.

Screening of Freshwater Microalgae for Resistance to Ultraviolet Radiation (자외선 차단능을 보유한 미세조류의 스크리닝)

  • Han, Mi-Ae;Han, Hye Jin;Jung, Moon Hee;Yoo, Rim Hwan;Hwang, Chae Eun;Myung, Su Hyun;Son, Yun Jin;Yoon, Young-Sil;Lee, Choul-Gyun
    • Journal of Marine Bioscience and Biotechnology
    • /
    • v.6 no.2
    • /
    • pp.131-137
    • /
    • 2014
  • Ultraviolet-B radiation (UV-B) in sunlight causes biological damages such as erythema and blister on skin. Microalgae have been in the limelight as an attractive feedstock for manufacturing functional materials. This study focused on screening microalga with protection ability against UV-B. The microalgae were isolated from local areas on April to June 2013 as well as June 2014. The cells were grown under continuous illumination from fluorescent lamps at $136.3{\pm}2.2{\mu}E/m^2/s$ in BG-11 medium at $15^{\circ}C$ for 12-14 days. The selected cells were spread on BG-11 agar and were exposed to UV-B (312 nm) for 20 and 25 minutes. The 13 strains among selected algae were classified. Among these, 9 strains were Scenedesmus sp. and the remains were Chlorella sp. Based on this study, it seems that Scenedesmus sp. and Chlorella sp. have resistibility against ultraviolet. These results will help to study on UV protection using microalgae.

Development of harmful ultraviolet blocking transparent flexible device using TiO2-x thin film process (TiO2-x 산화물 박막공정을 이용한 유해자외선차단 투명유연소재개발)

  • Kim, Geug Tae
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.29 no.3
    • /
    • pp.123-131
    • /
    • 2019
  • In this study, the development of transparent UV blocking material using $TiO_{2-x}$ oxide thin film process was developed. A process technology is related to a process technology for making a sample with ultraviolet-shielding property of visible light transmittance of 78 % or more (total light transmittance at 550 nm) and of a UV cut-off characteristic of more than 95 % at 315 nm in ultraviolet wavelength band. In this study, it is possible to establish a flexible device process condition of high performance ultraviolet (UV) shielding thin film, to design mixed type of transparent flexible device with heterogeneous characteristics and to formulate composite deposition technology, according to various market demands. Establishment of actual roll-to-roll continuous process and equipment and process technology will affect related industries greatly.

A Study on the Properties Changes of Wool Fabrics Dyed with Safflower under Ultraviolet(UV)-Light (홍화 염색 모직물의 자외선에 의한 성능 변화 연구)

  • Shin, Youn-Sook;Choi, Seung-Youn
    • Fashion & Textile Research Journal
    • /
    • v.10 no.2
    • /
    • pp.249-253
    • /
    • 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.