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Sample records for typical uv filters

  1. Occurrence and fate of benzotriazoles UV filters in a typical residential wastewater treatment plant in Harbin, China.

    Science.gov (United States)

    Zhao, Xue; Zhang, Zi-Feng; Xu, Lei; Liu, Li-Yan; Song, Wei-Wei; Zhu, Fu-Jie; Li, Yi-Fan; Ma, Wan-Li

    2017-08-01

    Benzotriazoles (BTs) UV filters are widely used as ultraviolet absorbents for our daily products, which received increasing attention in the past decades. Residential wastewater treatment plant (WWTP) is both an important sink for wastewater and a key pollution source for receiving water for these chemicals. In this study, pretreatment and gas chromatography-tandem mass spectrometry analysis method were developed to determine the occurrence and fate of 9 BTs UV filters in wastewater and sludge from the WWTP with anaerobic-oxic treatment process (A/O) and biological aerated filter treatment process (BAF). Totally, 81 wastewater samples and 11 sludge samples were collected in four seasons. In wastewater, UV-326 and UV-329 were frequently detected, while the highest mean concentrations were detected for UV-234 and UV-329. The concentrations were in the range of UV filters was >85% in A/O process and 60-77% in BAF process except for UV-350, which was more difficult to remove with lower removal efficiencies of 33.3% for both A/O and BAF. All the target chemicals except for UV-320 were detected in sludge samples with the mean concentration ranging from 0.90 ng/g to 303.39 ng/g. There was no significant difference with concentrations and removal efficiency among different seasons. Higher detection frequency and concentration of BTs UV filters in downstream of the receiving water system indicated the contribution of effluent of the WWTP. Compared with other rivers, the lower concentrations in surface water in the Songhua River indicated light pollution status with of BTs UV filters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. UV holographic filters

    Science.gov (United States)

    Kalyashova, Zoya N.

    2017-11-01

    A new approach to UV holographic filter's manufacturing, when the filters are the volume reflection holograms, working in UV region in the second Bragg diffraction order, is offered. The method is experimentally realized for wavelength of 266 nm.

  3. Inorganic UV filters

    Directory of Open Access Journals (Sweden)

    Eloísa Berbel Manaia

    2013-06-01

    Full Text Available Nowadays, concern over skin cancer has been growing more and more, especially in tropical countries where the incidence of UVA/B radiation is higher. The correct use of sunscreen is the most efficient way to prevent the development of this disease. The ingredients of sunscreen can be organic and/or inorganic sun filters. Inorganic filters present some advantages over organic filters, such as photostability, non-irritability and broad spectrum protection. Nevertheless, inorganic filters have a whitening effect in sunscreen formulations owing to the high refractive index, decreasing their esthetic appeal. Many techniques have been developed to overcome this problem and among them, the use of nanotechnology stands out. The estimated amount of nanomaterial in use must increase from 2000 tons in 2004 to a projected 58000 tons in 2020. In this context, this article aims to analyze critically both the different features of the production of inorganic filters (synthesis routes proposed in recent years and the permeability, the safety and other characteristics of the new generation of inorganic filters.

  4. Biobased Nanoparticles for Broadband UV Protection with Photostabilized UV Filters.

    Science.gov (United States)

    Hayden, Douglas R; Imhof, Arnout; Velikov, Krassimir P

    2016-12-07

    Sunscreens rely on multiple compounds to provide effective and safe protection against UV radiation. UV filters in sunscreens, in particular, provide broadband UV protection but are heavily linked to adverse health effects due to the generation of carcinogenic skin-damaging reactive oxygen species (ROS) upon solar irradiation. Herein, we demonstrate significant reduction in the ROS concentration by encapsulating an antioxidant photostabilizer with multiple UV filters into biobased ethyl cellulose nanoparticles. The developed nanoparticles display complete broadband UV protection and can form transparent and flexible films. This system therefore shows significant potential toward effective and safe nanoparticle-based UV protective coatings.

  5. Biobased Nanoparticles for Broadband UV Protection with Photostabilized UV Filters

    NARCIS (Netherlands)

    Hayden, D.R.|info:eu-repo/dai/nl/412640694; Imhof, A.|info:eu-repo/dai/nl/145641600; Velikov, K. P.|info:eu-repo/dai/nl/239483472

    2016-01-01

    Sunscreens rely on multiple compounds to provide effective and safe protection against UV radiation. UV filters in sunscreens, in particular, provide broadband UV protection but are heavily linked to adverse health effects due to the generation of carcinogenic skin-damaging reactive oxygen species

  6. UV filters for lighting of plants

    Science.gov (United States)

    Doehring, T.; Koefferlein, M.; Thiel, S.; Seidlitz, H. K.; Payer, H. D.

    1994-01-01

    The wavelength dependent interaction of biological systems with radiation is commonly described by appropriate action spectra. Particularly effective plant responses are obtained for ultraviolet (UV) radiation. Excess shortwave UV-B radiation will induce genetic defects and plant damage. Besides the ecological discussion of the deleterious effects of the excess UV radiation there is increasing interest in horticultural applications of this spectral region. Several metabolic pathways leading to valuable secondary plant products like colors, odors, taste, or resulting in mechanical strength and vitality are triggered by UV radiation. Thus, in ecologically as well as in economically oriented experiments the exact generation and knowledge of the spectral irradiance, particularly near the UV absorption edge, is essential. The ideal filter 'material' to control the UV absorption edge would be ozone itself. However, due to problems in controlling the toxic and chemically aggressive, instable gas, only rather 'small ozone filters' have been realized so far. In artificial plant lighting conventional solid filter materials such as glass sheets and plastic foils (celluloseacetate or cellulosetriacetate) which can be easily handled have been used to absorb the UV-C and the excess shortwave UV-B radiation of the lamp emissions. Different filter glasses are available which provide absorption properties suitable for gradual changes of the spectral UV-B illumination of artificial lighting. Using a distinct set of lamps and filter glasses an acceptable simulation of the UV-B part of natural global radiation can be achieved. The aging of these and other filter materials under the extreme UV radiation in the lamphouse of a solar simulator is presently unavoidable. This instability can be dealt with only by a precise spectral monitoring and by replacing the filters accordingly. For this reason attempts would be useful to develop real ozone filters which can replace glass filters. In

  7. UV filters for lighting of plants

    Science.gov (United States)

    Doehring, T.; Koefferlein, M.; Thiel, S.; Seidlitz, H. K.; Payer, H. D.

    1994-03-01

    The wavelength dependent interaction of biological systems with radiation is commonly described by appropriate action spectra. Particularly effective plant responses are obtained for ultraviolet (UV) radiation. Excess shortwave UV-B radiation will induce genetic defects and plant damage. Besides the ecological discussion of the deleterious effects of the excess UV radiation there is increasing interest in horticultural applications of this spectral region. Several metabolic pathways leading to valuable secondary plant products like colors, odors, taste, or resulting in mechanical strength and vitality are triggered by UV radiation. Thus, in ecologically as well as in economically oriented experiments the exact generation and knowledge of the spectral irradiance, particularly near the UV absorption edge, is essential. The ideal filter 'material' to control the UV absorption edge would be ozone itself. However, due to problems in controlling the toxic and chemically aggressive, instable gas, only rather 'small ozone filters' have been realized so far. In artificial plant lighting conventional solid filter materials such as glass sheets and plastic foils (celluloseacetate or cellulosetriacetate) which can be easily handled have been used to absorb the UV-C and the excess shortwave UV-B radiation of the lamp emissions. Different filter glasses are available which provide absorption properties suitable for gradual changes of the spectral UV-B illumination of artificial lighting. Using a distinct set of lamps and filter glasses an acceptable simulation of the UV-B part of natural global radiation can be achieved. The aging of these and other filter materials under the extreme UV radiation in the lamphouse of a solar simulator is presently unavoidable. This instability can be dealt with only by a precise spectral monitoring and by replacing the filters accordingly. For this reason attempts would be useful to develop real ozone filters which can replace glass filters. In

  8. UV filters for lighting of plants

    Energy Technology Data Exchange (ETDEWEB)

    Doehring, T.; Koefferlein, M.; Thiel, S.; Seidlitz, H.K.; Payer, H.D. [GSF-Forschungszentrum fuer Umwelt und Gesundheit GmbH, Oberschleissheim (Germany)

    1994-12-31

    Different filter glasses are available which provide absorption properties suitable for gradual changes of the spectral UV-B illumination of artificial lighting. Using a distinct set of lamps and filter glasses an acceptable simulation of the UV-B part of natural global radiation can be achieved. The ageing of these and other filter materials under the extreme UV radiation in the lamphouse of a solar simulator is presently unavoidable. This instability can be dealt with only by a precise spectral monitoring and by replacing the filters accordingly. For this reason attempts would be useful to develop real ozone filters which can replace glass filters. In any case chamber experiments require a careful selection of the filter material used and must be accompanied by a continuous UV-B monitoring.

  9. UV Fluorescence Photography of Works of Art : Replacing the Traditional UV Cut Filters with Interference Filters

    Directory of Open Access Journals (Sweden)

    Luís BRAVO PEREIRA

    2010-09-01

    Full Text Available For many years filters like the Kodak Wratten E series, or the equivalent Schneider B+W 415, were used as standard UV cut filters, necessary to obtain good quality on UV Fluorescence photography. The only problem with the use of these filters is that, when they receive the UV radiation that they should remove, they present themselves an internal fluorescence as side effect, that usually reduce contrast and quality on the final image. This article presents the results of our experiences on using some innovative filters, that appeared available on the market in recent years, projected to adsorb UV radiation even more efficiently than with the mentioned above pigment based standard filters: the interference filters for UV rejection (and, usually, for IR rejection too manufactured using interference layers, that present better results than the pigment based filters. The only problem with interference filters type is that they are sensitive to the rays direction and, because of that, they are not adequate to wide-angle lenses. The internal fluorescence for three filters: the B+W 415 UV cut (equivalent to the Kodak Wratten 2E, pigment based, the B+W 486 UV IR cut (an interference type filter, used frequently on digital cameras to remove IR or UV and the Baader UVIR rejection filter (two versions of this interference filter were used had been tested and compared. The final quality of the UV fluorescence images seems to be of a superior quality when compared to the images obtained with classic filters.

  10. UV Fluorescence Photography of Works of Art : Replacing the Traditional UV Cut Filters with Interference Filters

    OpenAIRE

    Luís BRAVO PEREIRA

    2010-01-01

    For many years filters like the Kodak Wratten E series, or the equivalent Schneider B+W 415, were used as standard UV cut filters, necessary to obtain good quality on UV Fluorescence photography. The only problem with the use of these filters is that, when they receive the UV radiation that they should remove, they present themselves an internal fluorescence as side effect, that usually reduce contrast and quality on the final image. This article presents the results of our experiences on usi...

  11. Photostability of cosmetic UV filters on mammalian skin under UV exposure.

    Science.gov (United States)

    Stiefel, Constanze; Schwack, Wolfgang; Nguyen, Yen-Thi Hai

    2015-01-01

    Previous studies showed that the common UV filter substances benzophenone-3 (BP-3), butyl methoxydibenzoylmethane (BM-DBM), octocrylene (OCR), ethylhexyl methoxycinnamate (EHMC), ethylhexyl salicylate (EHS) and ethylhexyl triazone (EHT) were able to react with amino side chains of different proteins in vitro. To transfer the results to mammalian skin conditions, sunscreen products were applied on both prepared fresh porcine skin and glass plates, followed by UV irradiation and the determination of depletion of the respective UV filters. Significantly lower recoveries of the UV filters extracted from skin samples than from glass plates indicated the additional reaction of the UV filters with skin constituents, when proteins will be the most important reactants. Among the products tested, BP-3 showed the greatest differences in recoveries between glass and skin samples of about 13% and 24% after 2 and 4 h of irradiation, respectively, followed by EHS > BM-DBM > OCR > EHMC > EHT. The obtained results raise the question, whether the common in vitro evaluations of sunscreens, using inert substrate materials like roughened quartz or polymethyl methacrylate (PMMA) plates are really suitable to fully replace in vivo methods, as they cannot include skin-typical reactions. © 2014 The American Society of Photobiology.

  12. Recent Advances on Endocrine Disrupting Effects of UV Filters

    OpenAIRE

    Wang, Jiaying; Pan, Liumeng; Wu, Shenggan; Lu, Liping; Xu, Yiwen; Zhu, Yanye; Guo, Ming; Zhuang, Shulin

    2016-01-01

    Ultraviolet (UV) filters are used widely in cosmetics, plastics, adhesives and other industrial products to protect human skin or products against direct exposure to deleterious UV radiation. With growing usage and mis-disposition of UV filters, they currently represent a new class of contaminants of emerging concern with increasingly reported adverse effects to humans and other organisms. Exposure to UV filters induce various endocrine disrupting effects, as revealed by increasing number of ...

  13. Exposure to phenols, parabens and UV filters

    DEFF Research Database (Denmark)

    Joensen, Ulla N.; Jørgensen, Niels; Thyssen, Jacob P.

    2017-01-01

    Concentrations of eight simple phenols, six parabens and nine UV filters were analysed in urine from 65 FLG loss-of-function mutation carriers and 130 non-carriers (controls). Regression analyses, controlling for urinary dilution and confounders, were performed to estimate associations between FLG mutation...... status and chemical concentrations in urine. Results FLG mutation carriers had 80% (13–180%) higher urinary concentrations of methyl paraben (MeP) and 91% (13–219%) higher concentrations of n-propyl paraben (n-PrP) than controls. For 13 compounds, levels were higher in FLG mutation carriers, although...

  14. Bragg Grating Optical Filters by UV Nanoimprinting

    Directory of Open Access Journals (Sweden)

    M. Casalboni

    2012-01-01

    Full Text Available Results on an optical waveguide filter operating in the near IR region are reported. The device consists of a hybrid sol-gel -based grating loaded waveguide, obtained through the merging of conventional photolithography and UV-nanoimprinting. Starting from submicrometric gratings, fabricated by electron beam lithography, a soft mould has been produced and the original structures were replicated onto sol-gel photosensitive films. A final photolithographic step allowed the production of grating-loaded channel waveguides. The devices were optically characterized by transmission measurements in the telecom range 1450–1590 nm. The filter extinction ratio is −11 dB and the bandwidth is 1.7 nm.

  15. UV Filters and Toursim: Their Impact on the Environment

    Science.gov (United States)

    Ultraviolet (UV) filters are widely used in cosmetics, sunscreens, and plastics to block UV radiation from the sun. Studies show that some sunscreens demonstrate estrogenicity and multiple hormonal activities in vitro. Because of the high consumption volume and high lipophilicity...

  16. Recent Advances on Endocrine Disrupting Effects of UV Filters.

    Science.gov (United States)

    Wang, Jiaying; Pan, Liumeng; Wu, Shenggan; Lu, Liping; Xu, Yiwen; Zhu, Yanye; Guo, Ming; Zhuang, Shulin

    2016-08-03

    Ultraviolet (UV) filters are used widely in cosmetics, plastics, adhesives and other industrial products to protect human skin or products against direct exposure to deleterious UV radiation. With growing usage and mis-disposition of UV filters, they currently represent a new class of contaminants of emerging concern with increasingly reported adverse effects to humans and other organisms. Exposure to UV filters induce various endocrine disrupting effects, as revealed by increasing number of toxicological studies performed in recent years. It is necessary to compile a systematic review on the current research status on endocrine disrupting effects of UV filters toward different organisms. We therefore summarized the recent advances on the evaluation of the potential endocrine disruptors and the mechanism of toxicity for many kinds of UV filters such as benzophenones, camphor derivatives and cinnamate derivatives.

  17. Recent Advances on Endocrine Disrupting Effects of UV Filters

    Directory of Open Access Journals (Sweden)

    Jiaying Wang

    2016-08-01

    Full Text Available Ultraviolet (UV filters are used widely in cosmetics, plastics, adhesives and other industrial products to protect human skin or products against direct exposure to deleterious UV radiation. With growing usage and mis-disposition of UV filters, they currently represent a new class of contaminants of emerging concern with increasingly reported adverse effects to humans and other organisms. Exposure to UV filters induce various endocrine disrupting effects, as revealed by increasing number of toxicological studies performed in recent years. It is necessary to compile a systematic review on the current research status on endocrine disrupting effects of UV filters toward different organisms. We therefore summarized the recent advances on the evaluation of the potential endocrine disruptors and the mechanism of toxicity for many kinds of UV filters such as benzophenones, camphor derivatives and cinnamate derivatives.

  18. Do 'cinnamon-sensitive' patients react to cinnamate UV filters?

    Science.gov (United States)

    Pentinga, Stefanie E; Kuik, Dirk J; Bruynzeel, Derk P; Rustemeyer, Thomas

    2009-04-01

    Use of sunscreens has increased dramatically worldwide, and some sunscreen chemicals may be allergens. Ultraviolet (UV) filters are added to various cosmetic products. Cinnamate UV filters are structurally related to cinnamon-related fragrances. The purpose of this study was to determine if 'cinnamon-sensitive' patients show positive photopatch tests to cinnamate UV filters and, therefore, should avoid these UV filters. We photopatch tested cinnamon-sensitive patients (n = 18) with cinnamon, cinnamon-related fragrances, Myroxylon pereirae, and two cinnamate UV filters. No positive photopatch test to cinnamate UV filters was found (95% confidence interval 0-13%). The risk of developing unwanted allergic contact dermatitis because of cinnamate UV filters in cinnamon-sensitive patients seems to be low, but our study population was small. Therefore, we recommend cinnamon-sensitive patients to perform a use test, for example the repeated open application test, before using cosmetic products containing cinnamate UV filters. In addition, physicians and patients should be aware that many sunscreens contain (cinnamon-related) fragrances and could, therefore, elicit allergic contact dermatitis in cinnamon-sensitive patients, independently from other potential sensitizing components of the sunscreen.

  19. Image quality, space-qualified UV interference filters

    Science.gov (United States)

    Mooney, Thomas A.

    1992-01-01

    The progress during the contract period is described. The project involved fabrication of image quality, space-qualified bandpass filters in the 200-350 nm spectral region. Ion-assisted deposition (IAD) was applied to produce stable, reasonably durable filter coatings on space compatible UV substrates. Thin film materials and UV transmitting substrates were tested for resistance to simulated space effects.

  20. UV blocking filters for polymeric films

    Science.gov (United States)

    Rayl, G. J.

    1979-01-01

    The concept of incorporating UV screening agents in silicone resins as a means of protecting underlying solar cell covers and adhesives from UV degradation is presented. A silicone hard-coat resin incorporating a UV screening agent was selected as a suitable coating material for PFA Teflon solar cell covers. Consideration is given to fabrication procedures and techniques for introduction of the UV screening agents into silicone resins and application of these UV-inhibited coatings to the Teflons. Some preliminary environmental tests, such as thermal shock and temperature humidity, were conducted.

  1. Deep UV Blocking Particle Filter, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — For sensitive detection of neutral and charged particles in satellite survey missions, instrumentation for the efficient rejection of EUV, Deep UV and visible flux...

  2. Determination of UV-filters in sunscreens by HPLC.

    Science.gov (United States)

    Chisvert, A; Pascual-Martí, M C; Salvador, A

    2001-04-01

    Simultaneous determination of six internationally authorised organic UV-filters in sunscreen formulations was performed by HPLC with UV spectrophotometric detection. The filters determined were: sulisobenzone, oxybenzone, octyl dimethyl PABA, octyl methoxycinnamate, octyl salicylate and homosalate. A C18 stationary phase and a mobile phase of ethanol water acetic acid (70:29.5:0.5) were used with a flow rate of 0.5 mL/min. UV measurements were carried out at 313 nm. The time required for the analysis was 25 min and the limits of detection were between 0.2 and 2 mg/L, except for sulisobenzone, which gave a limit of detection of 20 mg/L. The procedure proposed provides an accurate, fast and green analytical method, that does not involve toxic organic solvents.

  3. UV filters bioaccumulation in fish from Iberian river basins

    Energy Technology Data Exchange (ETDEWEB)

    Gago-Ferrero, Pablo [Dept. of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, E-08034 Barcelona (Spain); Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771 Athens (Greece); Díaz-Cruz, M. Silvia, E-mail: sdcqam@cid.csic.es [Dept. of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, E-08034 Barcelona (Spain); Barceló, Damià [Dept. of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, E-08034 Barcelona (Spain); Catalan Institute for Water Research (ICRA), Parc Científic i Tecnològic de la Universitat de Girona, C/ Emili Grahit, 101 Edifici H2O, E-17003 Girona (Spain)

    2015-06-15

    The occurrence of eight organic UV filters (UV-Fs) was assessed in fish from four Iberian river basins. This group of compounds is extensively used in cosmetic products and other industrial goods to avoid the damaging effects of UV radiation, and has been found to be ubiquitous contaminants in the aquatic ecosystem. In particular, fish are considered by the scientific community to be the most feasible organism for contamination monitoring in aquatic ecosystems. Despite that, studies on the bioaccumulation of UV-F are scarce. In this study fish samples from four Iberian river basins under high anthropogenic pressure were analysed by liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Benzophenone-3 (BP3), ethylhexyl methoxycinnamate (EHMC), 4-methylbenzylidene camphor (4MBC) and octocrylene (OC) were the predominant pollutants in the fish samples, with concentrations in the range of ng/g dry weight (d.w.). The results indicated that most polluted area corresponded to Guadalquivir River basin, where maximum concentrations were found for EHMC (241.7 ng/g d.w.). Sediments from this river basin were also analysed. Lower values were observed in relation to fish for OC and EHMC, ranging from below the limits of detection to 23 ng/g d.w. Accumulation levels of UV-F in the fish were used to calculate biota-sediment accumulation factors (BSAFs). These values were always below 1, in the range of 0.04–0.3, indicating that the target UV-Fs are excreted by fish only to some extent. The fact that the highest concentrations were determined in predators suggests that biomagnification of UV-F may take place along the freshwater food web. - Highlights: • First evidence of UV filters in fish from Iberian rivers • Biota-sediment accumulation factors (BSAFs) were always below 1. • Predator species presented higher UV-F concentrations suggesting trophic magnification.

  4. Urban groundwater contamination by residues of UV filters.

    Science.gov (United States)

    Jurado, Anna; Gago-Ferrero, Pablo; Vàzquez-Suñé, Enric; Carrera, Jesus; Pujades, Estanislao; Díaz-Cruz, M Silvia; Barceló, Damià

    2014-04-30

    The occurrence and fate of UV filters (UV F) in an urban aquifer in correlation with (1) the spatial distribution of UV F in Barcelona's groundwater, (2) the depth of the groundwater sample, (3) the physicochemical properties of the target compounds, (4) the recharge sources, and (5) the redox conditions of the Barcelona aquifers, were studied for the first time. The highest groundwater concentrations and the largest number of detected UV F were observed in an aquifer recharged by a polluted river (around 55 ng/L in SAP-4). In contrast, the urbanized areas had lower concentrations (around 20 ng/L in MPSP-1). Two pathways can be identified for UV F to enter the aquifers: (1) leakage of row sewage from the sewage network in urbanized areas and (2) wastewater treatment plant (WWTP) effluents discharged into the river. Measured concentrations of UV F were significantly much lower than those estimated from the waste water proportion in groundwater samples suggesting that UV F might undergo transformation processes in both reducing and oxidizing conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Optical Protection Filters for Harmful Laser Beams and UV Radiation

    Science.gov (United States)

    Azim M., Osama A.

    2007-02-01

    Due to the rapid growth of radiation protection applications in various devices and instruments, it is essential to use suitable filters for eye protection of the personal working in the radiation field. Different protection filters were produced to protect from four laser beam wavelengths (at 532nm, 632.8nm, 694nm and 1064nm) and block three UV bands (UVA, UVB, and UVC). The design structure of the required dielectric multilayer filters used optical thin film technology. The computer analyses of the multilayer filter formulas were prepared using Macleod Software for the production filter processes. The deposition technique was achieved on optical substrates (Glass BK-7 and Infrasil 301) by dielectric material combinations including Dralo (mixture of oxides TiO2/Al2O3), and Lima (mixture of oxides SiO2/Al2O3); deposition by an electron beam gun. The output transmittance curves for both theoretical and experimental values of all filters are presented. To validate the suitability for use in a `real world', rather than laboratory test application, full environmental assessment was also carried out. These filters exhibited high endurance after exposing them to the durability tests (adhesion, abrasion resistance and humidity) according to military standards MIL-C-675C and MIL-C-48497A.

  6. Optical Protection Filters for Harmful Laser Beams and UV Radiation

    International Nuclear Information System (INIS)

    Azim M, Osama A.

    2007-01-01

    Due to the rapid growth of radiation protection applications in various devices and instruments, it is essential to use suitable filters for eye protection of the personal working in the radiation field. Different protection filters were produced to protect from four laser beam wavelengths (at 532nm, 632.8nm, 694nm and 1064nm) and block three UV bands (UVA, UVB, and UVC). The design structure of the required dielectric multilayer filters used optical thin film technology. The computer analyses of the multilayer filter formulas were prepared using Macleod Software for the production filter processes. The deposition technique was achieved on optical substrates (Glass BK-7 and Infrasil 301) by dielectric material combinations including Dralo (mixture of oxides TiO2/Al2O3), and Lima (mixture of oxides SiO2/Al2O3); deposition by an electron beam gun. The output transmittance curves for both theoretical and experimental values of all filters are presented. To validate the suitability for use in a 'real world', rather than laboratory test application, full environmental assessment was also carried out. These filters exhibited high endurance after exposing them to the durability tests (adhesion, abrasion resistance and humidity) according to military standards MIL-C-675C and MIL-C-48497A

  7. Hormonal activity, cytotoxicity and developmental toxicity of UV filters.

    Science.gov (United States)

    Balázs, Adrienn; Krifaton, Csilla; Orosz, Ivett; Szoboszlay, Sándor; Kovács, Róbert; Csenki, Zsolt; Urbányi, Béla; Kriszt, Balázs

    2016-09-01

    Ultraviolet (UV) filters are commonly used compounds in personal care products and polymer based materials, as they can absorb solar energy in the UVA and UVB spectrum. However, they are able to bind to hormone receptors and have several and different types of hormonal activities determined by in vitro assays. One of the aims of this work was to measure the hormonal and cytotoxic activities of four frequently used UV filters using bioluminescence based yeast test organisms. Using Saccharomyces cerevisiae BLYES and BLYAS strains allowed the rapid and reliable detection of agonist and antagonist hormonal activities, whereas BLYR strain served to measure cytotoxicity. Results confirmed that all tested UV filters show multiple hormonal activities. Cytotoxicity is detected only in the case of benzophenone-3. Research data on the toxic effects of benzophenone-3, especially on aquatic organisms are scarce, so further investigations were carried out regarding its cytotoxic and teratogenic effects on bacteria and zebrafish (Danio rerio) embryos, respectively. Results revealed the cytotoxicity of benzophenone-3 not only to yeasts but to bacteria, as well as its ability to influence zebrafish embryo hatching and development. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. UV filters bioaccumulation in fish from Iberian river basins.

    Science.gov (United States)

    Gago-Ferrero, Pablo; Díaz-Cruz, M Silvia; Barceló, Damià

    2015-06-15

    The occurrence of eight organic UV filters (UV-Fs) was assessed in fish from four Iberian river basins. This group of compounds is extensively used in cosmetic products and other industrial goods to avoid the damaging effects of UV radiation, and has been found to be ubiquitous contaminants in the aquatic ecosystem. In particular, fish are considered by the scientific community to be the most feasible organism for contamination monitoring in aquatic ecosystems. Despite that, studies on the bioaccumulation of UV-F are scarce. In this study fish samples from four Iberian river basins under high anthropogenic pressure were analysed by liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Benzophenone-3 (BP3), ethylhexyl methoxycinnamate (EHMC), 4-methylbenzylidene camphor (4MBC) and octocrylene (OC) were the predominant pollutants in the fish samples, with concentrations in the range of ng/g dry weight (d.w.). The results indicated that most polluted area corresponded to Guadalquivir River basin, where maximum concentrations were found for EHMC (241.7 ng/gd.w.). Sediments from this river basin were also analysed. Lower values were observed in relation to fish for OC and EHMC, ranging from below the limits of detection to 23 ng/gd.w. Accumulation levels of UV-F in the fish were used to calculate biota-sediment accumulation factors (BSAFs). These values were always below 1, in the range of 0.04-0.3, indicating that the target UV-Fs are excreted by fish only to some extent. The fact that the highest concentrations were determined in predators suggests that biomagnification of UV-F may take place along the freshwater food web. Copyright © 2015. Published by Elsevier B.V.

  9. UV filters, ingredients with a recognized anti-inflammatory effect.

    Directory of Open Access Journals (Sweden)

    Céline Couteau

    Full Text Available BACKGROUND: To explain observed differences during SPF determination using either an in vivo or in vitro method, we hypothesized on the presence of ingredients having anti-inflammatory properties. METHODOLOGY/PRINCIPAL FINDINGS: To research our hypothesis, we studied the 21 UV filters both available on the market and authorized by European regulations and subjected these filters to the phorbol-myristate-acetate test using mice. We then catalogued the 13 filters demonstrating a significant anti-inflammatory effect with edema inhibition percentages of more than 70%. The filters are: diethylhexyl butamido triazone (92%, benzophenone-5 and titanium dioxide (90%, benzophenone-3 (83%, octocrylène and isoamyl p-methoxycinnamate (82%, PEG-25 PABA and homosalate (80%, octyl triazone and phenylbenzimidazole sulfonic acid (78%, octyl dimethyl PABA (75%, bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylamino hydroxybenzoyl hexylbenzoate (70%. These filters were tested at various concentrations, including their maximum authorized dose. We detected a dose-response relationship. CONCLUSIONS/SIGNIFICANCE: The anti-inflammatory effect of a sunscreen ingredient may affect the in vivo SPF value.

  10. Chemical UV Filters Mimic the Effect of Progesterone on Ca2+Signaling in Human Sperm Cells.

    Science.gov (United States)

    Rehfeld, A; Dissing, S; Skakkebæk, N E

    2016-11-01

    Progesterone released by cumulus cells surrounding the egg induces a Ca 2+ influx into human sperm cells via the cationic channel of sperm (CatSper) Ca 2+ channel and controls multiple Ca 2+ -dependent responses essential for fertilization. We hypothesized that chemical UV filters may mimic the physiological action of progesterone on CatSper, thus affecting Ca 2+ signaling in human sperm cells. We examined 29 UV filters allowed in sunscreens in the United States and/or the European Union for their ability to induce Ca 2+ signals in human sperm by applying measurements of the intracellular free Ca 2+ concentration. We found that 13 UV filters induced a significant Ca 2+ signal at 10 μM. Nine UV filters induced Ca 2+ signals primarily by activating the CatSper channel. The UV filters 3-benzylidene camphor (3-BC) and benzylidene camphor sulfonic acid competitively inhibited progesterone-induced Ca 2+ signals. Dose-response relations for the UV filters showed that the Ca 2+ signal-inducing effects began in the nanomolar-micromolar range. Single-cell Ca 2+ measurements showed a Ca 2+ signal-inducing effect of the most potent UV filter, 3-BC, at 10 nM. Finally, we demonstrated that the 13 UV filters acted additively in low-dose mixtures to induce Ca 2+ signals. In conclusion, 13 of 29 examined UV filters (44%) induced Ca 2+ signals in human sperm. Nine UV filters primarily activated CatSper and thereby mimicked the effect of progesterone. The UV filters 3-BC and benzylidene camphor sulfonic acid competitively inhibited progesterone-induced Ca 2+ signals. In vivo exposure studies are needed to investigate whether UV filter exposure affects human fertility.

  11. UV Blocking Glass: Low Cost Filters for Visible Light Photocatalytic Assessment

    OpenAIRE

    Charles W. Dunnill

    2014-01-01

    A number of commercially available art protection products have been compared and assessed for their suitability as UV blocking filters in the application of “visible light” photocatalytic research. Many groups claiming visible light photocatalytic success employ filters to block out stray UV radiation in order to justify that their photocatalysts are indeed visible light photocatalysts and not UV light photocatalysts. These filters come in varying degrees of ability and price and many author...

  12. Cytoprotective effect against UV-induced DNA damage and oxidative stress: role of new biological UV filter.

    Science.gov (United States)

    Said, T; Dutot, M; Martin, C; Beaudeux, J-L; Boucher, C; Enee, E; Baudouin, C; Warnet, J-M; Rat, P

    2007-03-01

    The majority of chemical solar filters are cytotoxic, particularly on sensitive ocular cells (corneal and conjunctival cells). Consequently, a non-cytotoxic UV filter would be interesting in dermatology, but more especially in ophthalmology. In fact, light damage to the eye can be avoided thanks to a very efficient ocular antioxidant system; indeed, the chromophores absorb light and dissipate its energy. After middle age, a decrease in the production of antioxidants and antioxidative enzymes appears with accumulation of endogenous molecules that are phototoxic. UV radiations can induce reactive oxygen species formation, leading to various ocular diseases. Because most UV filters are cytotoxic for the eye, we investigated the anti-UV properties of Calophyllum inophyllum oil in order to propose it as a potential vehicle, free of toxicity, with a natural UV filter action in ophthalmic formulation. Calophyllum inophyllum oil, even at low concentration (1/10,000, v/v), exhibited significant UV absorption properties (maximum at 300nm) and was associated with an important sun protection factor (18-22). Oil concentrations up to 1% were not cytotoxic on human conjunctival epithelial cells, and Calophyllum inophyllum oil appeared to act as a cytoprotective agent against oxidative stress and DNA damage (85% of the DNA damage induced by UV radiations were inhibited with 1% Calophyllum oil) and did not induce in vivo ocular irritation (Draize test on New Zealand rabbits). Calophyllum inophyllum oil thus exhibited antioxidant and cytoprotective properties, and therefore might serve, for the first time, as a natural UV filter in ophthalmic preparations.

  13. Sunscreens: are they beneficial for health? An overview of endocrine disrupting properties of UV-filters.

    Science.gov (United States)

    Krause, M; Klit, A; Blomberg Jensen, M; Søeborg, T; Frederiksen, H; Schlumpf, M; Lichtensteiger, W; Skakkebaek, N E; Drzewiecki, K T

    2012-06-01

    Today, topical application of sunscreens, containing ultraviolet-filters (UV-filters), is preferred protection against adverse effects of ultraviolet radiation. Evidently, use of sunscreens is effective in prevention of sunburns in various models. However, evidence for their protective effects against melanoma skin cancer is less conclusive. Three important observations prompted us to review the animal data and human studies on possible side effects of selected chemical UV-filters in cosmetics. (1) the utilization of sunscreens with UV-filters is increasing worldwide; (2) the incidence of the malignant disorder for which sunscreens should protect, malignant melanoma, is rapidly increasing and (3) an increasing number of experimental studies indicating that several UV-filters might have endocrine disruptive effects. The selected UV-filters we review in this article are benzophenone-3 (BP-3), 3-benzylidene camphor (3-BC), 3-(4-methyl-benzylidene) camphor (4-MBC), 2-ethylhexyl 4-methoxy cinnamate (OMC), Homosalate (HMS), 2-ethylhexyl 4-dimethylaminobenzoate (OD-PABA) and 4-aminobenzoic acid (PABA). The potential adverse effects induced by UV-filters in experimental animals include reproductive/developmental toxicity and disturbance of hypothalamic-pituitary-thyroid axis (HPT). Few human studies have investigated potential side effects of UV-filters, although human exposure is high as UV-filters in sunscreens are rapidly absorbed from the skin. One of the UV-filters, BP-3, has been found in 96% of urine samples in the US and several UV-filters in 85% of Swiss breast milk samples. It seems pertinent to evaluate whether exposure to UV-filters contribute to possible adverse effects on the developing organs of foetuses and children. © 2012 The Authors. International Journal of Andrology © 2012 European Academy of Andrology.

  14. Organic UV filters in personal care products in Switzerland: a survey of occurrence and concentrations.

    Science.gov (United States)

    Manová, Eva; von Goetz, Natalie; Hauri, Urs; Bogdal, Christian; Hungerbühler, Konrad

    2013-07-01

    Organic ultraviolet (UV) filters are a group of compounds designed to absorb UV radiation and hence protect our skin against UV-induced damage. Apart from traditional sunscreens, they can be found in many other categories of personal care products (PCPs). These include skin care, facial makeup and lip care products, which are often used simultaneously, and on a regular basis. The frequency of occurrence as well as concentrations of organic UV filters contained in PCPs change over time. Furthermore, in Switzerland the exact UV filter concentrations are confidential. To date, only limited data are available for the levels of organic UV filters in PCPs, and these data refer mainly to sunscreens. In this paper, we provide an up-to-date frequency of occurrence and concentrations of organic UV filters in PCPs, including for the first time PCPs used in everyday life. A total of 116 PCPs was selected on the basis of a product-use questionnaire and distributed among seven PCP categories: lip care products, lipsticks, face creams, liquid makeup foundations, aftershaves, hand creams, and sunscreens. Concentrations of 22 organic UV filters were measured in the selected PCPs. The most frequently occurring UV filters were butyl methoxydibenzoylmethane (BMBM) detected in 82 products (71%), ethylhexyl methoxycinnamate (EHMC) in 59 products (51%) and octocrylene (OCT) in 50 products (43%). BMBM, EHMC and OCT concentrations averaged 2.6%, 4.0%, and 6.0%, respectively. Overall, UV filter concentrations in PCPs applied regularly throughout the year can be as high as those in sunscreens that are primarily used for sun protection and hence applied only on selected days. PCPs that are used on a regular basis, and often simultaneously, thus represent an important and, as yet, unquantified source of UV filter exposure. This study provides essential information for aggregate exposure assessments that combine data on concentrations of individual UV filters widely used in a variety of PCP

  15. Environmental occurrence and risk of organic UV filters and stabilizers in multiple matrices in Norway.

    Science.gov (United States)

    Langford, Katherine H; Reid, Malcolm J; Fjeld, Eirik; Øxnevad, Sigurd; Thomas, Kevin V

    2015-07-01

    Eight organic UV filters and stabilizers were quantitatively determined in wastewater sludge and effluent, landfill leachate, sediments, and marine and freshwater biota. Crab, prawn and cod from Oslofjord, and perch, whitefish and burbot from Lake Mjøsa were selected in order to evaluate the potential for trophic accumulation. All of the cod livers analysed were contaminated with at least 1 UV filter, and a maximum concentration of almost 12 μg/g wet weight for octocrylene (OC) was measured in one individual. 80% of the cod livers contained OC, and approximately 50% of cod liver and prawn samples contained benzophenone (BP3). Lower concentrations and detection frequencies were observed in freshwater species and the data of most interest is the 4 individual whitefish that contained both BP3 and ethylhexylmethoxycinnamate (EHMC) with maximum concentrations of almost 200 ng/g wet weight. The data shows a difference in the loads of UV filters entering receiving water dependent on the extent of wastewater treatment. Primary screening alone is insufficient for the removal of selected UV filters (BP3, Padimate, EHMC, OC, UV-234, UV-327, UV-328, UV-329). Likely due in part to the hydrophobic nature of the majority of the UV filters studied, particulate loading and organic carbon content appear to be related to concentrations of UV filters in landfill leachate and an order of magnitude difference in these parameters correlates with an order of magnitude difference in the effluent concentrations of selected UV filters (Fig. 2). From the data, it is possible that under certain low flow conditions selected organic UV filters may pose a risk to surface waters but under the present conditions the risk is low, but some UV filters will potentially accumulate through the trophic food chain. Copyright © 2015. Published by Elsevier Ltd.

  16. Chemical UV Filters Mimic the Effect of Progesterone on Ca(2+) Signaling in Human Sperm Cells

    DEFF Research Database (Denmark)

    Rehfeld, A; Dissing, S; Skakkebæk, N E

    2016-01-01

    Progesterone released by cumulus cells surrounding the egg induces a Ca(2+) influx into human sperm cells via the cationic channel of sperm (CatSper) Ca(2+) channel and controls multiple Ca(2+)-dependent responses essential for fertilization. We hypothesized that chemical UV filters may mimic...... the physiological action of progesterone on CatSper, thus affecting Ca(2+) signaling in human sperm cells. We examined 29 UV filters allowed in sunscreens in the United States and/or the European Union for their ability to induce Ca(2+) signals in human sperm by applying measurements of the intracellular free Ca(2......+) signals. Dose-response relations for the UV filters showed that the Ca(2+) signal-inducing effects began in the nanomolar-micromolar range. Single-cell Ca(2+) measurements showed a Ca(2+) signal-inducing effect of the most potent UV filter, 3-BC, at 10 nM. Finally, we demonstrated that the 13 UV filters...

  17. Occurrence of pharmaceuticals and UV filters in swimming pools and spas.

    Science.gov (United States)

    Ekowati, Yuli; Buttiglieri, Gianluigi; Ferrero, Giuliana; Valle-Sistac, Jennifer; Diaz-Cruz, M Silvía; Barceló, Damià; Petrovic, Mira; Villagrasa, Marta; Kennedy, Maria D; Rodríguez-Roda, Ignasi

    2016-07-01

    The occurrence of 32 pharmaceuticals and 14 UV filters in swimming pools and spas was studied. Fifty-one water samples were collected from 17 pools located in sport centres and hotels in Catalonia, Spain. The samples were analysed by liquid chromatography-tandem mass spectrometry. The pharmaceuticals atenolol, carbamazepine, hydrochlorothiazide, metronidazole, ofloxacin, sulfamethoxazole, acetaminophen, ibuprofen, ketoprofen and phenazone were measured in water samples at concentrations higher than their limit of quantification (LOQ). The highest concentration of any individual pharmaceutical was measured for the diuretic hydrochlorothiazide (904 ng/L). The most frequently detected pharmaceutical was carbamazepine, as it was observed in more than half of all the water samples measured (53 %, 27/51). The UV filters at concentrations higher than LOQ in water samples were BP1, BP2, BP3, BP8, THB, 4DHB, 4MBC, OD-PABA, 1HBT, MeBT and DMeBT. The highest concentration of UV filter observed was 4MBC (69.3 ng/L) while the most frequent UV filters in the samples were 1HBT (59 %, 30/51). The results also showed that pharmaceuticals and UV filters were most frequently found in spas. Finally, from a water treatment technology perspective, the lowest occurrence of pharmaceuticals was in the pools applying sand filters followed by disinfection by sodium hypochlorite, while the lowest occurrence of UV filters was in the pools applying coagulation, sand filtration, UV and salt electrolysis.

  18. EDC IMPACT: Chemical UV filters can affect human sperm function in a progesterone-like manner.

    Science.gov (United States)

    Rehfeld, A; Egeberg, D L; Almstrup, K; Petersen, J H; Dissing, S; Skakkebæk, N E

    2018-01-01

    Human sperm cell function must be precisely regulated to achieve natural fertilization. Progesterone released by the cumulus cells surrounding the egg induces a Ca 2+ influx into human sperm cells via the CatSper Ca 2+ -channel and thereby controls sperm function. Multiple chemical UV filters have been shown to induce a Ca 2+ influx through CatSper, thus mimicking the effect of progesterone on Ca 2+ signaling. We hypothesized that these UV filters could also mimic the effect of progesterone on sperm function. We examined 29 UV filters allowed in sunscreens in the US and/or EU for their ability to affect acrosome reaction, penetration, hyperactivation and viability in human sperm cells. We found that, similar to progesterone, the UV filters 4-MBC, 3-BC, Meradimate, Octisalate, BCSA, HMS and OD-PABA induced acrosome reaction and 3-BC increased sperm penetration into a viscous medium. The capacity of the UV filters to induce acrosome reaction and increase sperm penetration was positively associated with the ability of the UV filters to induce a Ca 2+ influx. None of the UV filters induced significant changes in the proportion of hyperactivated cells. In conclusion, chemical UV filters that mimic the effect of progesterone on Ca 2+ signaling in human sperm cells can similarly mimic the effect of progesterone on acrosome reaction and sperm penetration. Human exposure to these chemical UV filters may impair fertility by interfering with sperm function, e.g. through induction of premature acrosome reaction. Further studies are needed to confirm the results in vivo . © 2018 The authors.

  19. EDC IMPACT: Chemical UV filters can affect human sperm function in a progesterone-like manner

    Directory of Open Access Journals (Sweden)

    A Rehfeld

    2017-12-01

    Full Text Available Human sperm cell function must be precisely regulated to achieve natural fertilization. Progesterone released by the cumulus cells surrounding the egg induces a Ca2+ influx into human sperm cells via the CatSper Ca2+-channel and thereby controls sperm function. Multiple chemical UV filters have been shown to induce a Ca2+ influx through CatSper, thus mimicking the effect of progesterone on Ca2+ signaling. We hypothesized that these UV filters could also mimic the effect of progesterone on sperm function. We examined 29 UV filters allowed in sunscreens in the US and/or EU for their ability to affect acrosome reaction, penetration, hyperactivation and viability in human sperm cells. We found that, similar to progesterone, the UV filters 4-MBC, 3-BC, Meradimate, Octisalate, BCSA, HMS and OD-PABA induced acrosome reaction and 3-BC increased sperm penetration into a viscous medium. The capacity of the UV filters to induce acrosome reaction and increase sperm penetration was positively associated with the ability of the UV filters to induce a Ca2+ influx. None of the UV filters induced significant changes in the proportion of hyperactivated cells. In conclusion, chemical UV filters that mimic the effect of progesterone on Ca2+ signaling in human sperm cells can similarly mimic the effect of progesterone on acrosome reaction and sperm penetration. Human exposure to these chemical UV filters may impair fertility by interfering with sperm function, e.g. through induction of premature acrosome reaction. Further studies are needed to confirm the results in vivo.

  20. Exposure to UV filters during summer and winter in Danish kindergarten children.

    Science.gov (United States)

    Krause, Marianna; Andersson, Anna-Maria; Skakkebaek, Niels E; Frederiksen, Hanne

    2017-02-01

    Ultra violet (UV) filters with known or suspected endocrine disrupting properties are widely used in sunscreens and other personal care products, clothing, food packaging and many other consumer products. Danish kindergarten children have sunscreens applied daily during summer to prevent skin burns. To estimate the assumed contribution of sunscreens to the total exposure to UV filters, we measured the urinary excretion of UV filters during summer and winter in kindergarten children. Spot- and first morning urines were collected during a summer and a winter day in 2013. A total of 266 urine samples were collected from 55 children and were analysed for content of benzophenone (BP), benzophenone-1 (BP-1), benzophenone-2 (BP-2), benzophenone-3 (BP-3), 5-chloro-2-hydroxybenzophenone (BP-7), 4-methyl-benzophenone (4-MBP), 4-hydroxybenzophenone (4-HBP), 3-(4-methylbenzylidene)-camphor (4-MBC), and 3-benzylidene camphor (3-BC) by LC-MS/MS. Of the analysed UV filters, the children excreted predominantly BP-1, BP-3 and 4-HBP. The urine levels were significantly higher in summer samples compared to winter samples, however exposure during winter was still evident. Furthermore, children with the highest concentrations of UV filters in summer urines also tended to be among those with the highest winter levels. Exposures to UV filters during summertime can partly be explained by the intended use of UV filters in sunscreens, which is considered to be beneficial for children during outdoor activities. However, exposure to UV filters all year round together with large inter-individual variation indicate that children's exposure to UV filters also comes from other consumer items, presumably highly influenced by the general lifestyle of an individual child: this is completely unintended, without benefit, and potentially harmful. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Exposure to UV filters during summer and winter in Danish kindergarten children

    DEFF Research Database (Denmark)

    Krause, Marianna; Andersson, Anna-Maria; Skakkebaek, Niels E

    2017-01-01

    BACKGROUND: Ultra violet (UV) filters with known or suspected endocrine disrupting properties are widely used in sunscreens and other personal care products, clothing, food packaging and many other consumer products. Danish kindergarten children have sunscreens applied daily during summer...... to prevent skin burns. OBJECTIVES: To estimate the assumed contribution of sunscreens to the total exposure to UV filters, we measured the urinary excretion of UV filters during summer and winter in kindergarten children. METHODS: Spot- and first morning urines were collected during a summer and a winter day...

  2. Environmental occurrence and distribution of organic UV stabilizers and UV filters in the sediment of Chinese Bohai and Yellow Seas.

    Science.gov (United States)

    Apel, Christina; Tang, Jianhui; Ebinghaus, Ralf

    2018-04-01

    Organic UV stabilizers and UV filters are applied to industrial materials and cosmetics worldwide. In plastics they prevent photo-induced degradation, while in cosmetics they protect human skin against harmful effects of UV radiation. This study reports on the occurrence and distribution of organic UV stabilizers and UV filters in the surface sediment of the Chinese Bohai and Yellow Seas for the first time. In total, 16 out of 21 analyzed substances were positively detected. Concentrations ranged from sub-ng/g dw to low ng/g dw. The highest concentration of 25 ng/g dw was found for octocrylene (OC) in the Laizhou Bay. In the study area, characteristic composition profiles could be identified. In Korea Bay, the dominating substances were OC and ethylhexyl salicylate (EHS). All other analytes were below their method quantification limit (MQL). Around the Shandong Peninsula, highest concentrations of benzotriazole derivatives were observed in this study with octrizole (UV-329) as the predominant compound, reaching concentrations of 6.09 ng/g dw. The distribution pattern of UV-329 and bumetrizole (UV-326) were related (Pearson correlation coefficient r > 0.98, p « 0.01 around the Shandong Peninsula), indicating an identical input pathway and similar environmental behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Exposure patterns of UV filters, fragrances, parabens, phthalates, organochlor pesticides, PBDEs, and PCBs in human milk: correlation of UV filters with use of cosmetics.

    Science.gov (United States)

    Schlumpf, Margret; Kypke, Karin; Wittassek, Matthias; Angerer, Juergen; Mascher, Hermann; Mascher, Daniel; Vökt, Cora; Birchler, Monika; Lichtensteiger, Walter

    2010-11-01

    In order to assess potential risks of exposure to environmental chemicals, more information on concomitant exposure to different chemicals is needed. We present data on chemicals in human milk of a cohort study (2004, 2005, 2006) of 54 mother/child pairs, where for the first time, cosmetic UV filters, synthetic musks, parabens and phthalate metabolites were analyzed in the same sample along with persistent organochlor pollutants (POPs), i.e., organochlor pesticides and metabolites, polybrominated diphenylethers and polychlorinated biphenyls (PCBs). The two groups of chemicals exhibited different exposure patterns. Six out of seven PCB congeners and a majority of pesticides were present in all milk samples, with significant correlations between certain PCB congener and pesticide levels, whereas the cosmetic-derived compounds, UV filters, parabens and synthetic musks, exhibited a more variable exposure pattern with inter-individual differences. UV filters were present in 85.2% of milk samples, in the range of PCB levels. Comparison with a questionnaire revealed a significant correlation between use of products containing UV filters and their presence in milk for two frequently used and detected UV filters, 4-methylbenzylidene camphor and octocrylene, and for the whole group of UV filters. Concentrations of PCBs and organochlor pesticides were within ranges seen in Western and Southern European countries. For several POPs, mean and/or maximum daily intake calculated from individual concentrations was above recent US EPA reference dose values. Our data emphasize the need for analyses of complex mixtures to obtain more information on inter-individual and temporal variability of human exposure to different types of chemicals. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. Thin carbon film serves as UV bandpass filter

    Science.gov (United States)

    1966-01-01

    Thin carbon film deposited on a 70 percent transparent screen provides a filter for narrow-band detectors in the extreme ultraviolet. The filter also suppresses scattered light and light of unwanted orders in vacuum spectrographs.

  5. Effects of Na and Ca on particle size; Effect of filtering on UV absorbance

    Data.gov (United States)

    U.S. Environmental Protection Agency — Effects of Na and Ca on particle size; Effect of filtering on UV absorbance. This dataset is associated with the following publication: Bouchard, D., C. Knightes, X....

  6. Investigations on (photo) reactions of cosmetic UV filters towards skin proteins

    OpenAIRE

    Stiefel, Constanze

    2014-01-01

    Although UV filters are important, widespread used cosmetic ingredients, their reaction potential towards skin proteins has hardly been studied so far. Therefore, the aim of the present thesis was to investigate the reactivity of widespread UV filter substances towards skin proteins using increasingly complex protein and skin model systems and different analytical techniques. At first, the development of a rapid high-performance thin-layer chromatographic (HPTLC) screening method on an ami...

  7. Influence of UV filters on the texture profile and efficacy of a cosmetic formulation.

    Science.gov (United States)

    Fossa Shirata, M M; Campos, P M B G Maia

    2017-12-01

    Considering that many cosmetic products contain UV filters in their composition and that few studies have evaluated the role of UV filters in the physical properties and clinical efficacy of these products, the aim of this study was to assess the influence of UV filters on the properties and immediate effects of a cosmetic formulation. Four cosmetic formulations, vehicle (V), vehicle containing UV filters (F), vehicle containing cassava polysaccharides and alfalfa (A) oligosaccharides and vehicle containing UV filters plus cassava polysaccharides and alfalfa oligosaccharides (multifunctional formulation, M) were developed. The texture profile of the formulations was analysed with a TA.XT plus Texturometer ® . Twenty female volunteers aged 39-45 years were then selected for the assessment of immediate clinical efficacy of the formulations under study and of transepidermal water loss (TEWL), stratum corneum water content and microrelief of the skin obtained with their use. The presence of UV filters resulted in an improvement of the physical properties of the multifunctional cosmetic formulation (M) and of skin microrelief. However, the presence of UV filters also caused a significant decrease in hydration. The presence of sunscreens had a negative influence on immediate skin hydration and TEWL. On the other hand, it positively influenced parameters related to the physical properties of the multifunctional formulation and skin microrelief. Thus, we conclude that the influence of UV filters on the development of cosmetic formulations is an important factor to be considered because it can have either positive or negative effect on the efficacy of the product. © 2017 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  8. Substance Flow Analysis and Source Mapping of Chemical UV-filters

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, E., E-mail: eve@env.dtu.dk; Andersen, H. R.; Ledin, A. [Technical University of Denmark, Department of Environmental Engineering (Denmark)

    2008-12-15

    Chemical ultraviolet (UV)-filters are used in sunscreens to protect the skin from harmful UV radiation which may otherwise cause sunburns and skin cancer. Commonly used chemical UV-filters are known to cause endocrine disrupting effects in both aquatic and terrestrial animals as well as in human skin cells. Here, source mapping and substance flow analysis were applied to find the sources of six UV-filters (oxybenzone, avobenzone, 4-methylbenzylidene camphor, octyl methoxycinnamate, octyl dimethyl PABA and homosalate) and to identify the most dominant flows of these substances in Denmark. Urban water, composed of wastewater and surface waters, was found to be the primary recipient of UV-filters, whereby wastewater received an estimated 8.5-65 tonnes and surface waters received 7.1-51 tonnes in 2005. In wastewater treatment plants, their sorption onto sludge is perceived to be an important process and presence in effluents can be expected due to a lack of biodegradability. In addition, the use of UV-filters is expected to continue to increase significantly. Not all filters (e.g., octyl dimethyl PABA and homosalate) are used in Denmark. For example, 4-MBC is mainly associated with self-tanning liquids and private import of sunscreens.

  9. Ultraviolet damage in solar cell assemblies with various UV filters

    Science.gov (United States)

    Meulenberg, A., Jr.

    1977-01-01

    Ultraviolet damage to the new violet and non-reflective type solar cell assemblies, was studied, and potential advantages of using coverslides with no filters or filters with cut-off wavelengths below 0.35 micron were determined. The experiments consisted of three types of tests on fused silica coverslides with 0.35- and 0.30-micron cut-off filters and no cut-off filters, as well as on ceria-doped microsheet coverslides. Ultraviolet irradiation for over 1500 hours at one sun conditions (AMO) was carried out under vacuum of about 1 million torr. Nearly identical results for non-reflective type cells with 0.35-micro cut-off filters or ceria-doped coverslides were obtained. The 0.30-um filtered cell shows greater than average degradation. The unfiltered cell shows an abrupt drop in the first 20 UVSH and very little subsequent degradation.

  10. Effects of the novel poly(methyl methacrylate) (PMMA)-encapsulated organic ultraviolet (UV) filters on the UV absorbance and in vitro sun protection factor (SPF).

    Science.gov (United States)

    Wu, Pey-Shiuan; Huang, Lan-Ni; Guo, Yi-Cing; Lin, Chih-Chien

    2014-02-05

    Sunscreens are thought to protect skin from many of the harmful effects of ultraviolet (UV) light and the photostability of sunscreens is thus an important concern in their application. Therefore, to discover new UV filters or to modify well-known UV filters are presents an important way for development of sunscreens. In this study, we presented several novel poly(methyl methacrylate) (PMMA) encapsulated organic UV filters, including encapsulated benzophenone-3 (TB-MS), avobenzone (TA-MS), octyl methoxycinnamate (TO-MS) and diethylamino hydroxybenzoyl hexyl benzoate (TD-MS). Our results have demonstrated that PMMA-encapsulated UV filters have improved safety, photoprotective ability and photostability. We proposed therefore that these PMMA-encapsulated UV filters can be used as ingredients for sunscreen products in the future. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. UV Blocking Glass: Low Cost Filters for Visible Light Photocatalytic Assessment

    Directory of Open Access Journals (Sweden)

    Charles W. Dunnill

    2014-01-01

    Full Text Available A number of commercially available art protection products have been compared and assessed for their suitability as UV blocking filters in the application of “visible light” photocatalytic research. Many groups claiming visible light photocatalytic success employ filters to block out stray UV radiation in order to justify that their photocatalysts are indeed visible light photocatalysts and not UV light photocatalysts. These filters come in varying degrees of ability and price and many authors fail to correctly characterise their filters in individual papers. The use of effective filters to prevent both false positive and false negative results is important to maintain scientific rigor and create accurate understanding of the subject. The optimum UV filter would have the highest UV blocking properties (<390 nm and simultaneously the highest visible light transmission (390–750 nm. Single and double layers of each of the glass products were assessed as well as laminate products. The conclusions show an inexpensive and highly effective setup for the conduction of visible light photochemistry that should be incorporated as a standard part in any researcher’s work where the claim of visible light activity is made.

  12. Toxicokinetics and metabolisms of benzophenone-type UV filters in rats

    International Nuclear Information System (INIS)

    Jeon, Hee-Kyung; Sarma, Sailendra Nath; Kim, Youn-Jung; Ryu, Jae-Chun

    2008-01-01

    Sunscreens containing UV filters are recommended to reduce damage caused by solar UV radiation. Recently, benzophenone (BP)-type UV filters have become widely used as UV stabilizers in skin-moisturizing products and sunscreen lotions; however, very little information is available regarding the potential harmful effects of prolonged exposure to these compounds. Therefore, we investigated the toxicokinetics and metabolism of BP-type UV filters in rats using gas chromatography-mass spectrometry (GC-MS). To examine the metabolism of BP-type UV filters, we analyzed the parent compounds BP and 2-hydroxy-4-methoxybenzophenone (HMB). In rats, BP was mainly converted to benzhydrol (BH) and 4-hydroxybenzophenone (HBP) (i.e., type A UV filters). In contrast, HMB was converted into at least three intermediates, including 2,4-dihydroxybenzophenone (DHB), which was formed via o-demethylation and subsequently converted into 2,3,4-trihydroxybenzophenone (THB), and 2,2'-dihydroxy-4-methoxybenzophenone (DHMB), which formed via the aromatic hydroxylation of HMB (i.e., type B UV filters). Next, the toxicokinetic curve for BP showed a peak concentration (C max ) of 2.06 ± 0.46 μg/ml at approximately 4 h after BP administration. After a single oral dose of HMB, the C max of HMB reached 21.21 ± 11.61 μg/ml within 3 h (T max ), and then declined rapidly compared to the kinetic curve of BP. The concentration of these metabolites in rat blood decreased much more slowly over time compared to the parent compounds. Thus, our results indicate that such metabolites might have more significant adverse effects than the parent compounds over the long term

  13. Ozonation of the oxybenzone, octinoxate, and octocrylene UV-filters: Reaction kinetics, absorbance characteristics, and transformation products.

    Science.gov (United States)

    Hopkins, Zachary R; Snowberger, Sebastian; Blaney, Lee

    2017-09-15

    UV-filters (UVFs) are active ingredients in personal care products that protect skin from exposure to UV light. Environmentally-relevant concentrations of UVFs have recently been linked to toxicity in aquatic organisms, necessitating research into improved UVF removal in water/wastewater treatment. Here, we investigated ozonation of the three most commonly employed UVFs: octinoxate (OMC), octocrylene (OC), and oxybenzone (OXY). Specific second-order rate constants for UVF reaction with ozone were identified as follows: OMC, 5.25×10 4 M -1 s -1 ; OC, 1.58M -1 s -1 ; OXY (neutral), 3.80×10 2 M -1 s -1 ; and, OXY (anion), 1.51×10 6 M -1 s -1 . These kinetic parameters indicated that OMC and OXY undergo significant (2-log or greater) transformation for typical ozone exposures in disinfection processes; however, minimal oxidation is expected for OC. UV absorbance mapping was employed to characterize the loss of UVF activity (i.e., absorbance across the UV-A, UV-B, and UV-C ranges) during ozonation. These 4-dimensional maps also confirmed ozone attack mechanisms, namely reaction at phenolate (OXY) and olefin (OMC, OC) groups. Primary transformation products from these reactions were identified for all three UVFs of concern. For OC and OXY, the benzophenone structure is conserved, suggesting that transformation products retain toxicity concerns. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Natural Microbial UV Radiation Filters - Mycosporine-like Amino Acids

    Czech Academy of Sciences Publication Activity Database

    Řezanka, Tomáš; Temina, M.; Tolstikov, A. G.; Dembitsky, V. M.

    2004-01-01

    Roč. 49, č. 4 (2004), s. 339-352 ISSN 0015-5632 Institutional research plan: CEZ:AV0Z5020903 Keywords : uv radiation * maas * ultraviolet-b Subject RIV: EE - Microbiology, Virology Impact factor: 1.034, year: 2004

  15. Optical filters for UV to near IR space applications

    Science.gov (United States)

    Begou, T.; Krol, H.; Hecquet, Christophe; Bondet, C.; Lumeau, J.; Grèzes-Besset, C.; Lequime, M.

    2017-11-01

    We present hereafter the results on the fabrication of complex optical filters within the Institut Fresnel in close collaboration with CILAS. Bandpass optical filters dedicated to astronomy and space applications, with central wavelengths ranging from ultraviolet to near infrared, were deposited on both sides of glass substrates with performances in very good congruence with theoretical designs. For these applications, the required functions are particularly complex as they must present a very narrow bandwidth as well as a high level of rejection over a broad spectral range. In addition to those severe optical performances, insensitivity to environmental conditions is necessary. For this purpose, robust solutions with particularly stable performances have to be proposed.

  16. UV filters are an environmental threat in the Gulf of Mexico: a case study of Texas coastal zones

    OpenAIRE

    Hamidreza Sharifan; David Klein; Audra N. Morse

    2016-01-01

    UV filters are the main ingredients in many cosmetics and personal care products. A significant amount of lipophilic UV filters annually enters the surface water due to large numbers of swimmers and sunbathers. The nature of these compounds cause bioaccumulation in commercial fish, particularly in estuarine areas. Consequently, biomagnification in the food chain will occur. This study estimated the amount of four common UV filters (ethylhexyl methoxycinnamate, EHMC; octocrylene, OC; butyl met...

  17. Plasma Treatment to Remove Carbon from Indium UV Filters

    Science.gov (United States)

    Greer, Harold F.; Nikzad, Shouleh; Beasley, Matthew; Gantner, Brennan

    2012-01-01

    The sounding rocket experiment FIRE (Far-ultraviolet Imaging Rocket Experiment) will improve the science community fs ability to image a spectral region hitherto unexplored astronomically. The imaging band of FIRE (.900 to 1,100 Angstroms) will help fill the current wavelength imaging observation hole existing from approximately equal to 620 Angstroms to the GALEX band near 1,350 Angstroms. FIRE is a single-optic prime focus telescope with a 1.75-m focal length. The bandpass of 900 to 1100 Angstroms is set by a combination of the mirror coating, the indium filter in front of the detector, and the salt coating on the front of the detector fs microchannel plates. Critical to this is the indium filter that must reduce the flux from Lymanalpha at 1,216 Angstroms by a minimum factor of 10(exp -4). The cost of this Lyman-alpha removal is that the filter is not fully transparent at the desired wavelengths of 900 to 1,100 Angstroms. Recently, in a project to improve the performance of optical and solar blind detectors, JPL developed a plasma process capable of removing carbon contamination from indium metal. In this work, a low-power, low-temperature hydrogen plasma reacts with the carbon contaminants in the indium to form methane, but leaves the indium metal surface undisturbed. This process was recently tested in a proof-of-concept experiment with a filter provided by the University of Colorado. This initial test on a test filter showed improvement in transmission from 7 to 9 percent near 900 with no process optimization applied. Further improvements in this performance were readily achieved to bring the total transmission to 12% with optimization to JPL's existing process.

  18. UV filters induce transcriptional changes of different hormonal receptors in Chironomus riparius embryos and larvae.

    Science.gov (United States)

    Ozáez, Irene; Aquilino, Mónica; Morcillo, Gloria; Martínez-Guitarte, José-Luis

    2016-07-01

    Organic ultraviolet (UV) filters are emerging contaminants that are ubiquitous in fresh and marine aquatic systems due to their extensive use in cosmetics, plastics, paints, textiles, and many other industrial products. The estrogenic effects of organic UV filters have been long demonstrated in vertebrates, and other hormonal activities may be altered, according to more recent reports. The impact of UV filters on the endocrine system of invertebrates is largely unknown. We have previously reported that some UV filters may affect ecdysone-related genes in the aquatic insect Chironomus riparius, an ecotoxicologically important model organism. To further analyze other possible effects on endocrine pathways, we first characterized four pivotal genes related with hormonal pathways in insects; thereafter, these genes were assessed for alterations in transcriptional activity after exposure to 4-methylbenzylidene camphor (4MBC) or benzophenone-3 (BP-3), two extensively used sunscreens. We found that both chemicals disturbed the expression of all four genes analyzed: hormonal receptor 38 (HR38), methoprene-tolerant (Met), membrane-associate progesterone receptor (MAPR) and insulin-like receptor (INSR), measured by changes in mRNA levels by real-time PCR. An upregulatory effect at the genomic level was detected in different developmental stages. Interestingly, embryos appeared to be more sensitive to the action of the UV filters than larvae. Our results suggest that the risk of disruption through different endocrine routes is not negligible, considering the significant effects of UV filters on key hormonal receptor and regulatory genes. Further effort is needed to develop environmental risk assessment studies on these pollutants, particularly for aquatic invertebrate model organisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Distribution and seasonal occurrence of UV filters in rivers and wastewater treatment plants in Korea.

    Science.gov (United States)

    Ekpeghere, Kalu Ibe; Kim, Un-Jung; O, Sung-Hee; Kim, Hee-Young; Oh, Jeong-Eun

    2016-01-15

    The occurrence and distribution of eight UV filters benzophenone (BP), benzophenone-3 (BP-3), ethylhexyl methoxy cinnamate (EHMC), 4-methylbenzylidene camphor (4-MBC), 2-ethylhexyl 4-dimethylaminobenzoate (OD-PABA), 2-ethylhexyl salicylate (EHS), isoamyl benzoate, and benzyl cinnamate in eleven sites among three rivers, five sewage treatment plants (STPs), and four wastewater treatment plants (WWTPs) located in different parts of Korea was investigated. The total concentrations of UV filters in the three sampled seasons were 62.9-412 ng L(-1) (river), 417-5055 ng L(-1) (STP influent), 108-2201 ng L(-1) (STP effluent), 122-4154 ng L(-1) (WWTP influent), and 120-849 ng L(-1) (WWTP effluent). The concentration of the target pollutants in the influent of the treatment systems was directly proportional to the resident population density. A seasonal increase of >27% was observed in the total concentration of the UV filters in the rivers and influents of the treatment plants (TPs) during summer. BP, BP-3, EHMC, 4-MBC, and EHS were the most dominant, showing a distinct distribution pattern that was dependent on the effectiveness of the treatment process and properties of each compound. The concentrations of the UV filters were higher in the TPs influents than in the rivers, and the most dominant UV filters in the rivers were those with low removal rate. Although biological treatment processes favored the removal of the UV filter compounds in the TPs, complete removal was not achieved before discharge into the rivers. Copyright © 2015. Published by Elsevier B.V.

  20. EDC IMPACT: Chemical UV filters can affect human sperm function in a progesterone-like manner

    OpenAIRE

    Rehfeld, A; Egeberg, D L; Almstrup, K; Petersen, J H; Dissing, S; Skakkebæk, N E

    2017-01-01

    Human sperm cell function must be precisely regulated to achieve natural fertilization. Progesterone released by the cumulus cells surrounding the egg induces a Ca2+ influx into human sperm cells via the CatSper Ca2+-channel and thereby controls sperm function. Multiple chemical UV filters have been shown to induce a Ca2+ influx through CatSper, thus mimicking the effect of progesterone on Ca2+ signaling. We hypothesized that these UV filters could also mimic the effect of progesterone on spe...

  1. Stability Study of Sunscreens with Free and Encapsulated UV Filters Contained in Plastic Packaging.

    Science.gov (United States)

    Briasco, Benedetta; Capra, Priscilla; Mannucci, Barbara; Perugini, Paola

    2017-05-31

    Sunscreens play a fundamental role in skin cancer prevention and in protection against photo-aging. UV filters are often photo-unstable, especially in relation to their vehicles and, being lipophilic substances, they are able to interact with plastic packaging. Finally, UV filter stability can be significantly affected by the routine use of the product at high temperatures. This work aims to study the stability of sunscreen formulations in polyethylene packaging. Butyl methoxydibenzoylmethane and octocrylene, both in a free form and as encapsulated filters were chosen as UV filters. Stability evaluations were performed both in the packaging and on the formulations. Moreover, a further two non-destructive techniques, near-infrared (NIR) spectroscopy and a multiple light scattering technique, were also used to evaluate the stability of the formulation. Results demonstrated clearly that all of the pack underwent significant changes in its elastic/plastic behavior and in external color after solar irradiation. From the evaluation of the extractable profile of untreated and treated packaging material an absorption of 2-phenoxyethanol and octocrylene were shown. In conclusion, the results highlighted clearly that a reduction of the UV filter in the formulation packed in high-density polyethylene/low-density polyethylene (HDPE/LDPE) material can occur over time, reducing the protective effect of the product when applied to the skin.

  2. Stability Study of Sunscreens with Free and Encapsulated UV Filters Contained in Plastic Packaging

    Directory of Open Access Journals (Sweden)

    Benedetta Briasco

    2017-05-01

    Full Text Available Sunscreens play a fundamental role in skin cancer prevention and in protection against photo-aging. UV filters are often photo-unstable, especially in relation to their vehicles and, being lipophilic substances, they are able to interact with plastic packaging. Finally, UV filter stability can be significantly affected by the routine use of the product at high temperatures. This work aims to study the stability of sunscreen formulations in polyethylene packaging. Butyl methoxydibenzoylmethane and octocrylene, both in a free form and as encapsulated filters were chosen as UV filters. Stability evaluations were performed both in the packaging and on the formulations. Moreover, a further two non-destructive techniques, near-infrared (NIR spectroscopy and a multiple light scattering technique, were also used to evaluate the stability of the formulation. Results demonstrated clearly that all of the pack underwent significant changes in its elastic/plastic behavior and in external color after solar irradiation. From the evaluation of the extractable profile of untreated and treated packaging material an absorption of 2-phenoxyethanol and octocrylene were shown. In conclusion, the results highlighted clearly that a reduction of the UV filter in the formulation packed in high-density polyethylene/low-density polyethylene (HDPE/LDPE material can occur over time, reducing the protective effect of the product when applied to the skin.

  3. Simultaneous analysis and monitoring of 16 UV filters in cosmetics by high-performance liquid chromatography.

    Science.gov (United States)

    Kim, Dojung; Kim, Sangseop; Kim, Seol-A; Choi, Myoengsin; Kwon, Kyoung-Jin; Kim, Mijeong; Kim, Dong-Sup; Kim, Seung-Hee; Choi, Bo-Kyung

    2012-01-01

    Sixteen UV filters were simultaneously analyzed using the high-performance liquid chromatographic method. They were drometrizole (USAN Drometrizole), 4-methylbenzylidene camphor (USAN Enzacamene), menthyl anthranilate (USAN Menthyl anthranilate), benzophenone-3 (USAN Oxybenzone), benzophenone-8 (USAN Dioxybenzone), butyl methoxydibenzoylmethane (USAN Avobenzone), ethylhexyl triazone (USAN Octyl triazone), octocrylene (USAN Octocrylene), ethylhexyl dimethyl p-aminobenzoic acid (USAN Padimate O), ethylhexyl methoxycinnamate (USAN Octinoxate), p-aminobenzoic acid (USAN Aminobenzoic acid), 2-phenylbenzimidazole-5-sulfonic acid (USAN Ensulizole), isoamyl p-methoxycinnamate (USAN Amiloxate), and recent UV filters such as diethylhexyl butamidotriazone (USAN Iscotrizinol), methylene bis-benzotriazolyl tetramethylbutylphenol (USAN Bisoctrizole), and terephthalylidene dicamphor sulfonic acid (USAN Ecamsule). Separation of the UV filters was carried out in a C(18) column with a gradient of methanol-phosphate buffer, and the UV detection was at 300, 320, or 360 nm without any interference. The limits of detection were between 0.08 and 1.94 μg/ml, and the limits of quantitation were between 0.24 and 5.89 μg/ml. The extracting solvent for the UV filters was methanol, except for ethylhexyl triazone and methylene bis-benzotriazolyl tetramethylbutylphenol, which were prepared with tetrahydrofuran. The recoveries from spiked samples were between 94.90% and 116.54%, depending on the matrixes used. The developed method was applied to 23 sunscreens obtained from local markets, and the results were acceptable to their own criteria and to maximum authorized concentrations. Consequently, these results would provide a simple extracting method and a simultaneous determination for various UV filters, which can improve the quality control process as well as the environmental monitoring of sunscreens.

  4. Ecotoxicity of two organic UV-filters to the freshwater caddisfly Sericostoma vittatum.

    Science.gov (United States)

    Campos, Diana; Gravato, Carlos; Fedorova, Ganna; Burkina, Viktoriia; Soares, Amadeu M V M; Pestana, João L T

    2017-09-01

    Organic ultraviolet filters (UV-filters) used for protection against radiation in personal care products and other materials (e.g. textiles, plastic products) are considered emerging contaminants of aquatic ecosystem. Benzophenone-3 (BP3) and 3-(4-methylbenzylidene)camphor (4-MBC) are the most commonly used organic UV-filters and have been reported in freshwater environments due to contamination through discharges from wastewater treatment plants and swimming pools or by direct contamination from recreational activities. Our aim was to evaluate the ecotoxicological effects of these UV-filters using the freshwater caddisfly Sericostoma vittatum' biochemical biomarkers and energy processing related endpoints (feeding behaviour, energy reserves and cellular metabolism). In laboratory trials, both compounds induced feeding inhibition of S. vittatum at 3.55 mg/kg of BP3 and at concentrations ≥2.57 mg/kg of 4-MBC, decreased carbohydrates content at 3.55 and 6.95 mg/kg of BP3 and 4-MBC respectively, and increased total glutathione levels at concentrations ≥1.45 and 1.35 mg/kg of BP3 and 4-MBC respectively. No significant effects were observed on endpoints associated with oxidative stress, antioxidant defences, phase II biotransformation or neurotoxicity after exposure to the two UV-filters. Our results show that environmental relevant concentrations of BP3 and 4-MBC, can negatively impact freshwater insects and demonstrate the importance of monitoring the ecological effects of organic UV-filters using non-model invertebrate species. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Toxicity of organic UV-filters to the aquatic midge Chironomus riparius.

    Science.gov (United States)

    Campos, Diana; Gravato, Carlos; Quintaneiro, Carla; Golovko, Oksana; Žlábek, Vladimír; Soares, Amadeu M V M; Pestana, João L T

    2017-09-01

    Despite the frequent detection of organic ultraviolet-filters (UV-filters) in freshwater sediments, there is a lack of ecotoxicological data undermining a correct risk assessment for these emerging contaminants. The present study assessed the effects of three of the most commonly used UV-filters (benzophenone-3 - BP3; 3-(4-methylbenzylidene)camphor - 4-MBC and octocrylene - OC) on Chironomus riparius life history and biochemical responses. Standard ecotoxicological assays confirmed that all compounds impaired growth of C. riparius larvae and induced developmental effects such as delayed emergence and a reduction of imagoes weight. Concerning the biochemical responses analysed no evidences of oxidative damage in lipids or neurotoxicity (tested assessing acetylcholinesterase activity) were observed for any of the tested compounds. However, 4-MBC exposure induced a decrease in catalase activity and an increase in glutathione-S-transferase activity at 14.13mg/Kg while OC exposure caused an increase in total glutathione levels at 0.23 and 18.23mg/Kg. Exposure to all UV-filters tested, increased energy consumption on C. riparius with significant differences above 1.00mg/Kg for BP3, 0.09mg/Kg for 4-MBC and 2.13mg/Kg for OC. These results suggest that environmental relevant concentrations of UV-filters can cause deleterious effects to aquatic benthic species, such as C. riparius, and call for further research concerning effects of organic UV-filters on natural invertebrate communities and ecosystem functioning. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. A review of organic UV-filters in wastewater treatment plants.

    Science.gov (United States)

    Ramos, Sara; Homem, Vera; Alves, Arminda; Santos, Lúcia

    2016-01-01

    UV-filters are a group of compounds which have been massively used in the past years due to the recent concerns with sunburns, premature skin ageing and the risk of developing skin cancer, related to sun exposure. At the moment, these compounds have been identified by the scientific community as emerging pollutants, due to their persistence in the environment, potential to accumulate in biota and potential threat as endocrine disruptors. At some point, the majority of sunscreens will find their way into wastewater (due to bathing and washing activities) and because wastewater treatment plants (WWTPs) are not able to remove and/or degrade them, consequently they find their way into rivers, lakes and ocean, so it is not surprising that UV-filters are found in the environment. Therefore, wastewater treatment plants should be the focus of the scientific community aiming to better understand the fate of the UV-filters and develop new technologies to remove them from wastewater and sludge. This review, aims to provide the current state of the art in the occurrence and fate of UV-filters in wastewater treatment plants and how the technologies that are being used are successfully removing these compounds from both wastewater and sludge. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Widespread occurrence of estrogenic UV-filters in aquatic ecosystems in Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Fent, Karl, E-mail: karl.fent@bluewin.c [University of Applied Sciences (FHNW), School of Life Sciences, Gruendenstrasse 40, CH-4132 Muttenz (Switzerland); Swiss Federal Institute of Technology (ETH Zurich), Department of Environmental Sciences, CH-8092 Zuerich (Switzerland); Zenker, Armin [University of Applied Sciences (FHNW), School of Life Sciences, Gruendenstrasse 40, CH-4132 Muttenz (Switzerland); Rapp, Maja [Swiss Federal Institute of Technology (ETH Zurich), Institute of Environmental Engineering, Wolfgang-Pauli-Strasse 15, CH-8093 Zuerich (Switzerland)

    2010-05-15

    We performed a trace analytical study covering nine hormonally active UV-filters by LC-MS/MS and GC-MS in river water and biota. Water was analysed at 10 sites above and below wastewater treatment plants in the river Glatt using polar organic chemical integrative samplers (POCIS). Four UV-filters occurred in the following order of decreasing concentrations; benzophenone-4 (BP-4) > benzophenone-3 (BP-3) > 3-(4-methyl)benzylidene-camphor (4-MBC) > 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC). BP-4 ranged from 0.27 to 24.0 mug/POCIS, BP-3, 4-MBC and EHMC up to 0.1 mug/POCIS. Wastewater was the most important source. Levels decreased with higher river water flow. No significant in-stream removal occurred. BP-3, 4-MBC and EHMC were between 6 and 68 ng/L in river water. EHMC was accumulated in biota. In all 48 macroinvertebrate and fish samples from six rivers lipid-weighted EHMC occurred up to 337 ng/g, and up to 701 ng/g in 5 cormorants, suggesting food-chain accumulation. UV-filters are found to be ubiquitous in aquatic systems. - Several UV-filters from cosmetics and materials protection occur in rivers and EHMC accumulates in biota.

  8. Maternal exposure to UV filters and associations to maternal thyroid hormones and IGF-I/IGFBP3 and birth outcomes

    DEFF Research Database (Denmark)

    Krause, Marianna; Frederiksen, Hanne; Sundberg, Karin

    2018-01-01

    BACKGROUND: Several chemical UV filters/absorbers (in the following called UV filters) have endocrine disrupting properties in vitro and in vivo. Exposure to these chemicals, especially during prenatal development, is of concern. OBJECTIVES: To examine maternal exposure to UV filters and associat......BACKGROUND: Several chemical UV filters/absorbers (in the following called UV filters) have endocrine disrupting properties in vitro and in vivo. Exposure to these chemicals, especially during prenatal development, is of concern. OBJECTIVES: To examine maternal exposure to UV filters......) in urine and 4-hydroxy-benzophenone (4-HBP) in serum were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The relationships between 2nd trimester maternal concentrations of the three chemical UV filters and maternal serum concentrations of thyroid hormones and growth factors, as well...... and the possible impact on maternal thyroid hormones and growth factors, and on fetal growth, calls for further studies on possible long term consequences of the exposure to UV filters on fetal development and children's health....

  9. Hepatic oxidative stress biomarker responses in freshwater fish Carassius auratus exposed to four benzophenone UV filters.

    Science.gov (United States)

    Liu, Hui; Sun, Ping; Liu, Hongxia; Yang, Shaogui; Wang, Liansheng; Wang, Zunyao

    2015-09-01

    Benzophenone (BP) type UV filters are widely used in many personal care products to protect human from UV irradiation. Despite the estrogenic potencies to fish and the environmental occurrences of BP derivatives in aquatic systems, little information is available regarding their effects on the antioxidant defense system in fish. In this work, the oxidative stress induced in livers of Carassius auratus was assessed using four biomarkers. The integrated biomarker response (IBR) was applied to assess the overall antioxidant status in fish. Moreover, liver tissues were also studied histologically. The changes in the activities of antioxidant enzymes and glutathione levels suggested that BPs generates oxidative stress in fish. The IBR index revealed that the hepatic oxidative toxicity followed the order BP-1>BP-2>BP-4>BP-3. The histopathological analysis revealed lesions caused by BPs. This investigation provides essential information for assessing the potential ecological risk of BP-type UV filters. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Design of adaptive filter amplifier in UV communication based on DSP

    Science.gov (United States)

    Lv, Zhaoshun; Wu, Hanping; Li, Junyu

    2016-10-01

    According to the problem of the weak signal at receiving end in UV communication, we design a high gain, continuously adjustable adaptive filter amplifier. Based on proposing overall technical indicators and analyzing its working principle of the signal amplifier, we use chip LMH6629MF and two chips of AD797BN to achieve three-level cascade amplification. And apply hardware of DSP TMS320VC5509A to implement digital filtering. Design and verification by Multisim, Protel 99SE and CCS, the results show that: the amplifier can realize continuously adjustable amplification from 1000 to 10000 times without distortion. Magnification error is <=%4@1000 10000. And equivalent input noise voltage of amplification circuit is <=6 nV/ √Hz @30KHz 45KHz, and realizing function of adaptive filtering. The design provides theoretical reference and technical support for the UV weak signal processing.

  11. Evaluation of ecotoxicological effects of benzophenone UV filters: Luminescent bacteria toxicity, genotoxicity and hormonal activity.

    Science.gov (United States)

    Zhang, Qiuya; Ma, Xiaoyan; Dzakpasu, Mawuli; Wang, Xiaochang C

    2017-08-01

    The widespread use of organic ultraviolet (UV) filters in personal care products raises concerns about their potentially hazardous effects on human and ecosystem health. In this study, the toxicities of four commonly used benzophenones (BPs) UV filters including benzophenone (BP), 2-Hydroxybenzophenone (2HB), 2-Hydroxy-4-methoxybenzophenone (BP3), and 2-Hydroxy-4-methoxybenzophenone-5-sulfonicacid (BP4) in water were assayed in vitro using Vibrio fischeri, SOS/umu assay, and yeast estrogen screen (YES) assay, as well as in vivo using zebrafish larvae. The results showed that the luminescent bacteria toxicity, expressed as logEC 50 , increased with the lipophilicity (logKow) of BPs UV filters. Especially, since 2HB, BP3 and BP4 had different substituent groups, namely -OH, -OCH 3 and -SO 3 H, respectively, these substituent functional groups had a major contribution to the lipophilicity and acute toxicity of these BPs. Similar tendency was observed for the genotoxicity, expressed as the value of induction ratio=1.5. Moreover, all the target BPs UV filters showed estrogenic activity, but no significant influences of lipophilicity on the estrogenicity were observed, with BP3 having the weakest estrogenic efficiency in vitro. Although BP3 displayed no noticeable adverse effects in any in vitro assays, multiple hormonal activities were observed in zebrafish larvae including estrogenicity, anti-estrogenicity and anti-androgenicity by regulating the expression of target genes. The results indicated potential hazardous effects of BPs UV filters and the importance of the combination of toxicological evaluation methods including in vitro and in vivo assays. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. The effects of binary UV filter mixtures on the midge Chironomus riparius

    International Nuclear Information System (INIS)

    Ozáez, Irene; Morcillo, Gloria; Martínez-Guitarte, José-Luis

    2016-01-01

    Organic ultraviolet (UV) filters are used in a wide variety of products, including cosmetics, to prevent damage from UV light in tissues and industrial materials. Their extensive use has raised concerns about potential adverse effects in human health and aquatic ecosystems that accumulate these pollutants. To increase sun radiation protection, UV filters are commonly used in mixtures. Here, we studied the toxicity of binary mixtures of 4-methylbenzylidene camphor (4MBC), octyl-methoxycinnamate (OMC), and benzophenone-3 (BP-3), by evaluating the larval mortality of Chironomus riparius. Also molecular endpoints have been analyzed, including alterations in the expression levels of a gene related with the endocrine system (EcR, ecdysone receptor) and a gene related with the stress response (hsp70, heat shock protein 70). The results showed that the mortality caused by binary mixtures was similar to that observed for each compound alone; however, some differences in LC50 were observed between groups. Gene expression analysis showed that EcR mRNA levels increased in the presence of 0.1 mg/L 4MBC but returned to normal levels after exposure to mixtures of 4MBC with 0.1, 1, and 10 mg/L of BP-3 or OMC. In contrast, the hsp70 mRNA levels increased after exposure to the combinations tested of 4MBC and BP-3 or OMC mixtures. These data suggest that 4MBC, BP-3, and OMC may have antagonist effects on EcR gene transcription and a synergistic effect on hsp70 gene activation. This is the first experimental study to show the complex patterned effects of UV filter mixtures on invertebrates. The data suggest that the interactions within these chemicals mixtures are complex and show diverse effects on various endpoints. - Highlights: • Chironomus riparius is sensitive to UV filter binary mixtures. • UV filters binary mixtures show antagonism on survival of 4th instar larvae. • BP-3 and OMC antagonize the stimulatory effect of 4MBC on EcR gene. • 4MBC, OMC, and BP-3 induce hsp70

  13. The effects of binary UV filter mixtures on the midge Chironomus riparius

    Energy Technology Data Exchange (ETDEWEB)

    Ozáez, Irene; Morcillo, Gloria; Martínez-Guitarte, José-Luis, E-mail: jlmartinez@ccia.uned.es

    2016-06-15

    Organic ultraviolet (UV) filters are used in a wide variety of products, including cosmetics, to prevent damage from UV light in tissues and industrial materials. Their extensive use has raised concerns about potential adverse effects in human health and aquatic ecosystems that accumulate these pollutants. To increase sun radiation protection, UV filters are commonly used in mixtures. Here, we studied the toxicity of binary mixtures of 4-methylbenzylidene camphor (4MBC), octyl-methoxycinnamate (OMC), and benzophenone-3 (BP-3), by evaluating the larval mortality of Chironomus riparius. Also molecular endpoints have been analyzed, including alterations in the expression levels of a gene related with the endocrine system (EcR, ecdysone receptor) and a gene related with the stress response (hsp70, heat shock protein 70). The results showed that the mortality caused by binary mixtures was similar to that observed for each compound alone; however, some differences in LC50 were observed between groups. Gene expression analysis showed that EcR mRNA levels increased in the presence of 0.1 mg/L 4MBC but returned to normal levels after exposure to mixtures of 4MBC with 0.1, 1, and 10 mg/L of BP-3 or OMC. In contrast, the hsp70 mRNA levels increased after exposure to the combinations tested of 4MBC and BP-3 or OMC mixtures. These data suggest that 4MBC, BP-3, and OMC may have antagonist effects on EcR gene transcription and a synergistic effect on hsp70 gene activation. This is the first experimental study to show the complex patterned effects of UV filter mixtures on invertebrates. The data suggest that the interactions within these chemicals mixtures are complex and show diverse effects on various endpoints. - Highlights: • Chironomus riparius is sensitive to UV filter binary mixtures. • UV filters binary mixtures show antagonism on survival of 4th instar larvae. • BP-3 and OMC antagonize the stimulatory effect of 4MBC on EcR gene. • 4MBC, OMC, and BP-3 induce hsp70

  14. Removing UV-A and UV-C radiation from UV-B fluorescent lamp emissions. Differences in the inhibition of photosynthesis in the marine alga Dunaliella tertiolecta using chromate versus cellulose acetate-polyester filters.

    Science.gov (United States)

    White, Andrea L; Jahnke, Leland S

    2004-01-01

    Ultraviolet-B (UV-B; 280-320 nm)-emitting lamps unavoidably emit ultraviolet-A (UV-A; 320-400 nm) and ultraviolet-C (UV-C; UV-C "contamination" using a liquid potassium chromate (K(2)CrO(4)) filter, thus allowing more direct assessment of the effects of UV-B exposure. Cultures of the green marine alga Dunaliella tertiolecta were grown in the absence of UV radiation. Sunlamps supplied the UV radiation for a 24 h exposure (solar radiation was not used in this study). The UV radiation was filtered either by the standard method (i.e. cellulose acetate (CA) with polyester = Mylar controls) or by a liquid filter of potassium chromate. Photosynthetic responses were compared. Major decreases in the ratio of variable to maximal fluorescence in dark-adapted cells and photosynthetic capacity were observed in CA-filtered cultures, whereas no change was observed in cells exposed to the same UV-B flux with the UV-A removed by K(2)CrO(4). The use of a CA filter with a Mylar control does not link results unequivocally to UV-B radiation. Such results should be interpreted with caution.

  15. Analysis of UV filters in tap water and other clean waters in Spain.

    Science.gov (United States)

    Díaz-Cruz, M Silvia; Gago-Ferrero, Pablo; Llorca, Marta; Barceló, Damià

    2012-03-01

    The present paper describes the development of a method for the simultaneous determination of five hormonally active UV filters namely benzophenone-3 (BP3), 3-(4-methylbenzylidene) camphor (4MBC), 2-ethylhexyl 4-(dimethylamino) benzoate (OD-PABA), 2-ethylhexyl 4-methoxycinnamate (EHMC) and octocrylene (OC) by means of solid-phase extraction and gas chromatography-electron impact ionization-mass spectrometry. Under optimized conditions, this methodology achieved low method limits of detection (needed for clean waters, especially drinking water analysis), between 0.02 and 8.42 ng/L, and quantitative recovery rates higher than 73% in all cases. Inter- and intraday precision for all compounds were lower than 7% and 11%, respectively. The optimized methodology was applied to perform the first survey of UV absorbing compounds in tap water from the metropolitan area and the city of Barcelona (Catalonia, Spain). In addition, other types of clean water matrices (mineral bottled water, well water and tap water treated with an ion-exchange resin) were investigated as well. Results evidenced that all the UV filters investigated were detected in the water samples analyzed. The compounds most frequently found were EHMC and OC. Maximum concentrations reached in tap water were 290 (BP3), 35 (4MBC), 110 (OD-PABA), 260 (EHMC), and 170 ng/L (OC). This study constitutes the first evidence of the presence of UV filter residues in tap water in Europe.

  16. In the shadow of the Cosmetic Directive — Inconsistencies in EU environmental hazard classification requirements for UV-filters

    International Nuclear Information System (INIS)

    Sobek, A.; Bejgarn, S.; Rudén, C.; Molander, L.; Breitholtz, M.

    2013-01-01

    UV-filters are chemicals with potentially environmental hazardous properties. In the European Union (EU), UV-filters contained in sunscreen products are currently regulated by the Cosmetic Directive (from July 2013 by the Cosmetic Products Regulation). Environmental hazard classifications according to the regulation on classification, labelling and packaging of substances and mixtures (CLP) must be determined for UV-filters contained in industrial chemical products, whereas UV-filters contained in sunscreens are exempted from CLP. In this study we determined the potential environmental hazard classifications of UV-filters and sunscreen products if the CLP regulation was to be required for cosmetic products. Two sunscreen products were evaluated in accordance with the aquatic environmental hazard criteria for mixtures. The results highlight that the inconsistencies in the current EU regulation of UV filters hamper the risk management of environmental hazards of UV filters used in cosmetic products. Almost 50% of the investigated UV-filters approved for use in cosmetic products on the European market according to the current Cosmetic Directive were identified to meet the CLP classification as being hazardous to the aquatic environment. Assuming a worst-case scenario, the two examined sunscreens could both be classified as hazardous to the aquatic environment with long-lasting effects according to CLP classification criteria. Hence, if the CLP regulation was applicable to sunscreen products, both brands could potentially be labelled with the environmental hazard pictogram and associated hazard and precautionary statements. Including cosmetic products, and thereby sunscreens, in the CLP regulation would contribute to a more harmonized and transparent regulation of potentially hazardous substances on the EU market. - Highlights: • UV-filters are used in both cosmetic and industrial products/applications • UV-filters in cosmetic products are excluded from CLP • We

  17. Repartition of oil miscible and water soluble UV filters in an applied sunscreen film determined by confocal Raman microspectroscopy.

    Science.gov (United States)

    Sohn, Myriam; Buehler, Theodor; Imanidis, Georgios

    2016-07-06

    Photoprotection provided by topical sunscreens is expressed by the sun protection factor (SPF) which depends primarily on the UV filters contained in the product and the applied sunscreen amount. Recently, the vehicle was shown to significantly impact film thickness distribution of an applied sunscreen and sunscreen efficacy. In the present work, repartition of the UV filters within the sunscreen film upon application is investigated for its role to affect sun protection efficacy. The spatial repartition of an oil-miscible and a water-soluble UV filter within the sunscreen film was studied using confocal Raman microspectroscopy. Epidermis of pig ear skin was used as substrate for application of three different sunscreen formulations, an oil-in-water emulsion, a water-in-oil emulsion, and a clear lipo-alcoholic spray (CAS) and SPF in vitro was measured. Considerable differences in the repartition of the UV filters upon application and evaporation of volatile ingredients were found between the tested formulations. A nearly continuous phase of lipid-miscible UV filter was formed only for the WO formulation with dispersed aggregates of water-soluble UV filter. OW emulsion and CAS exhibited interspersed patches of the two UV filters, whereas the segregated UV filter domains of the latter formulation were by comparison of a much larger scale and spanned the entire thickness of the sunscreen film. CAS therefore differed markedly from the other two formulations with respect to filter repartition. This difference should be reflected in SPF when the absorption spectra of the employed UV filters are not the same. Confocal Raman microspectroscopy was shown to be a powerful technique for studying this mechanism of sun protection performance of sunscreens.

  18. Advances in analytical methods and occurrence of organic UV-filters in the environment — A review

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Sara; Homem, Vera, E-mail: vhomem@fe.up.pt; Alves, Arminda; Santos, Lúcia

    2015-09-01

    UV-filters are a group of compounds designed mainly to protect skin against UVA and UVB radiation, but they are also included in plastics, furniture, etc., to protect products from light damage. Their massive use in sunscreens for skin protection has been increasing due to the awareness of the chronic and acute effects of UV radiation. Some organic UV-filters have raised significant concerns in the past few years for their continuous usage, persistent input and potential threat to ecological environment and human health. UV-filters end up in wastewater and because wastewater treatment plants are not efficient in removing them, lipophilic compounds tend to sorb onto sludge and hydrophilics end up in river water, contaminating the existing biota. To better understand the risk associated with UV-filters in the environment a thorough review regarding their physicochemical properties, toxicity and environmental degradation, analytical methods and their occurrence was conducted. Higher UV-filter concentrations were found in rivers, reaching 0.3 mg/L for the most studied family, the benzophenone derivatives. Concentrations in the ng to μg/L range were also detected for the p-aminobenzoic acid, cinnamate, crylene and benzoyl methane derivatives in lake and sea water. Although at lower levels (few ng/L), UV-filters were also found in tap and groundwater. Swimming pool water is also a sink for UV-filters and its chlorine by-products, at the μg/L range, highlighting the benzophenone and benzimidazole derivatives. Soils and sediments are not frequently studied, but concentrations in the μg/L range have already been found especially for the benzophenone and crylene derivatives. Aquatic biota is frequently studied and UV-filters are found in the ng/g-dw range with higher values for fish and mussels. It has been concluded that more information regarding UV-filter degradation studies both in water and sediments is necessary and environmental occurrences should be monitored more

  19. Theoretical insights on flavanones as antioxidants and UV filters: A TDDFT and NLMO study.

    Science.gov (United States)

    Ajmala Shireen, P; Abdul Mujeeb, V M; Muraleedharan, K

    2017-05-01

    UV radiations can cause several irritations to the skin like sunburn, photo aging and even skin cancer. Sunscreens are widely used to protect the skin against these harmful radiations. One of the ingredients present in these sunscreens are organic molecules capable of absorbing these harmful radiations. Recently, the search is on for antioxidant molecules which can act as UV filters as they can facilitate photo protection. In this study, a computational investigation based on density functional theory (DFT) is attempted on flavanones namely pinocembrin, pinostrobin and alpinetin found in Boesenbergia pandurata. Several quantum chemical descriptors are computed to understand the antioxidant potentiality of these molecules. Quantum chemical descriptors of these flavanone molecules are found to be comparable to that of well-known anti-oxidant quercetin. UV response of these molecules are studied using time dependent density functional theory (TD-DFT) formalism and by means of natural bond orbital (NBO) theory. It could be seen that these molecules exhibit a broad absorption in the UV region 270-390nm. This falls exactly in the region of harmful UVB and UVA radiation. Thus, these molecules have the potential to absorb the harmful UV radiation. From NLMO cluster studies, the orbital contribution to absorption is explained. In flavanones, unlike other classes of flavonoids, there is a discontinuity in the electron conjugation due to the absence of C2C3 double bond. This might be the key structural feature that leads to the absorption of these molecules to be centered around the UV region. These molecules can thus be treated as promising candidates for antioxidant UV filters in sunscreens. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Assessment of the photo-degradation of UV-filters and radical-induced peroxidation in cosmetic sunscreen formulations.

    Science.gov (United States)

    Damiani, Elisabetta; Astolfi, Paola; Giesinger, Jochen; Ehlis, Thomas; Herzog, Bernd; Greci, Lucedio; Baschong, Werner

    2010-03-01

    Photo-instability of common UV-filters is a well documented phenomenon. This study develops a method for concomitant measurement of photostability and photo-induced ROS generation in cosmetic formulations. Oil-in-water formulations containing three common UV filters (OMC, BMDBM, EHT), individually or combined, were further supplemented with phosphatidylcholine and exposed to UVA. All filters show spectral decrease after UVA exposure. OMC and EHT do not induce significant lipid-peroxidation (as measured by TBARS production) while BMDBM does. In the latter case, this is reduced when BMDBM is combined with OMC but not with EHT. Neither OMC nor EHT stabilize BMDBM with respect to loss of absorbance. ROS-generation assessed via TBARS formation was supported by EPR experiments. The UV-induced changes in UV-filter performance, as monitored in the model formulations and in commercial sunscreens, demonstrate that this is a simple and effective method for stability assessment of sunscreen filters under conditions of use.

  1. Interaction mechanisms between organic UV filters and bovine serum albumin as determined by comprehensive spectroscopy exploration and molecular docking.

    Science.gov (United States)

    Ao, Junjie; Gao, Li; Yuan, Tao; Jiang, Gaofeng

    2015-01-01

    Organic UV filters are a group of emerging PPCP (pharmaceuticals and personal care products) contaminants. Current information is insufficient to understand the in vivo processes and health risks of organic UV filters in humans. The interaction mechanism of UV filters with serum albumin provides critical information for the health risk assessment of these active ingredients in sunscreen products. This study investigates the interaction mechanisms of five commonly used UV filters (2-hydroxy-4-methoxybenzophenone, BP-3; 2-ethylhexyl 4-methoxycinnamate, EHMC; 4-methylbenzylidene camphor, 4-MBC; methoxydibenzoylmethane, BDM; homosalate, HMS) with bovine serum albumin (BSA) by spectroscopic measurements of fluorescence, circular dichroism (CD), competitive binding experiments and molecular docking. Our results indicated that the fluorescence of BSA was quenched by these UV filters through a static quenching mechanism. The values of the binding constant (Ka) ranged from (0.78±0.02)×10(3) to (1.29±0.01)×10(5) L mol(-1). Further exploration by synchronous fluorescence and CD showed that the conformation of BSA was demonstrably changed in the presence of these organic UV filters. It was confirmed that the UV filters can disrupt the α-helical stability of BSA. Moreover, the results of molecular docking revealed that the UV filter molecule is located in site II (sub-domain IIIA) of BSA, which was further confirmed by the results of competitive binding experiments. In addition, binding occurred mainly through hydrogen bonding and hydrophobic interaction. This study raises critical concerns regarding the transportation, distribution and toxicity effects of organic UV filters in human body. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Reaction of benzophenone UV filters in the presence of aqueous chlorine: kinetics and chloroform formation.

    Science.gov (United States)

    Duirk, Stephen E; Bridenstine, David R; Leslie, Daniel C

    2013-02-01

    The transformation of two benzophenone UV filters (Oxybenzone and Dioxybenzone) was examined over the pH range 6-11 in the presence of excess aqueous chlorine. Under these conditions, both UV filters were rapidly transformed by aqueous chlorine just above circumneutral pH while transformation rates were significantly lower near the extremes of the pH range investigated. Observed first-order rate coefficients (k(obs)) were obtained at each pH for aqueous chlorine concentrations ranging from 10 to 75 μM. The k(obs) were used to determine the apparent second-order rate coefficient (k(app)) at each pH investigated as well as determine the reaction order of aqueous chlorine with each UV filter. The reaction of aqueous chlorine with either UV filter was found to be an overall second-order reaction, first-order with respect to each reactant. Assuming elemental stoichiometry described the reaction between aqueous chlorine and each UV filter, models were developed to determine intrinsic rate coefficients (k(int)) from the k(app) as a function of pH for both UV filters. The rate coefficients for the reaction of HOCl with 3-methoxyphenol moieties of oxybenzone (OXY) and dioxybenzone (DiOXY) were k(1,OxY) = 306 ± 81 M⁻¹s⁻¹ and k(1,DiOxY) = 154 ± 76 M⁻¹s⁻¹, respectively. The k(int) for the reaction of aqueous chlorine with the 3-methoxyphenolate forms were orders of magnitude greater than the un-ionized species, k(2,OxY) = 1.03(±0.52) × 10⁶ M⁻¹s⁻¹ and k(2_1,DiOxY) = 4.14(±0.68) × 10⁵ M⁻¹s⁻¹. Also, k(int) for the reaction of aqueous chlorine with the DiOXY ortho-substituted phenolate moiety was k(2_2,DiOxY) = 2.17(±0.30) × 10³ M⁻¹s⁻¹. Finally, chloroform formation potential for OXY and DiOXY was assessed over the pH range 6-10. While chloroform formation decreased as pH increased for OXY, chloroform formation increased as pH increased from 6 to 10 for DiOXY. Ultimate molar yields of chloroform per mole of UV filter were pH dependent

  3. Effects of Relative Humidity and Spraying Medium on UV Decontamination of Filters Loaded with Viral Aerosols

    Science.gov (United States)

    Woo, Myung-Heui; Grippin, Adam; Anwar, Diandra; Smith, Tamara; Wander, Joseph D.

    2012-01-01

    Although respirators and filters are designed to prevent the spread of pathogenic aerosols, a stockpile shortage is anticipated during the next flu pandemic. Contact transfer and reaerosolization of collected microbes from used respirators are also a concern. An option to address these potential problems is UV irradiation, which inactivates microbes by dimerizing thymine/uracil in nucleic acids. The objective of this study was to determine the effects of transmission mode and environmental conditions on decontamination efficiency by UV. In this study, filters were contaminated by different transmission pathways (droplet and aerosol) using three spraying media (deionized water [DI], beef extract [BE], and artificial saliva [AS]) under different humidity levels (30% [low relative humidity {LRH}], 60% [MRH], and 90% [HRH]). UV irradiation at constant intensity was applied for two time intervals at each relative humidity condition. The highest inactivation efficiency (IE), around 5.8 logs, was seen for DI aerosols containing MS2 on filters at LRH after applying a UV intensity of 1.0 mW/cm2 for 30 min. The IE of droplets containing MS2 was lower than that of aerosols containing MS2. Absorption of UV by high water content and shielding of viruses near the center of the aggregate are considered responsible for this trend. Across the different media, IEs in AS and in BE were much lower than in DI for both aerosol and droplet transmission, indicating that solids present in AS and BE exhibited a protective effect. For particles sprayed in a protective medium, RH is not a significant parameter. PMID:22685135

  4. UV protection filters by dielectric multilayer thin films on Glass BK-7 and Infrasil 301

    International Nuclear Information System (INIS)

    Abdel-Aziz, M.M.; Azim, Osama A.; Abdel-Wahab, L.A.; Seddik, Mohamed M.

    2006-01-01

    The increasing use of Ultraviolet (UV) light in medicine, industrial environments, for cosmetic use, and even in consumer products necessitates that greater attention be paid to the potential hazards of this type of electromagnetic radiation. To avoid any adverse effects of exposure to this type of radiation, four suitable protection filters were produced to block three UV bands (UVA, UVB, and UVC). The design structure of the required dielectric multilayer filters was done by optical thin film technology using the absorbing property of UV radiation for the substrates and dielectric materials. The computer analyses of the multilayer filter formulas were prepared using Macleod Software for the production processes. The deposition technique was achieved on optical substrates (Glass BK-7 and Infrasil 301) by dielectric material combinations including Titanium dioxide (Ti 2 O 3 ), Hafnium dioxide (HfO 2 ), and Lima (mixture of oxides SiO 2 /Al 2 O 3 ); deposition being achieved using an electron beam gun. The output results of the theoretical and experimental transmittance values for spectral band from 200 nm to 800 nm were discussed in four processes. To analyze the suitability for use in 'real world' applications, the test pieces were subjected to the durability tests (adhesion, abrasion resistance, and humidity) according to Military Standard MIL-C-675C and MIL-C-48497A

  5. UV protection filters by dielectric multilayer thin films on Glass BK-7 and Infrasil 301

    Science.gov (United States)

    Abdel-Aziz, M. M.; Azim, Osama A.; Abdel-Wahab, L. A.; Seddik, Mohamed M.

    2006-10-01

    The increasing use of Ultraviolet (UV) light in medicine, industrial environments, for cosmetic use, and even in consumer products necessitates that greater attention be paid to the potential hazards of this type of electromagnetic radiation. To avoid any adverse effects of exposure to this type of radiation, four suitable protection filters were produced to block three UV bands (UVA, UVB, and UVC). The design structure of the required dielectric multilayer filters was done by optical thin film technology using the absorbing property of UV radiation for the substrates and dielectric materials. The computer analyses of the multilayer filter formulas were prepared using Macleod Software for the production processes. The deposition technique was achieved on optical substrates (Glass BK-7 and Infrasil 301) by dielectric material combinations including Titanium dioxide (Ti 2O 3), Hafnium dioxide (HfO 2), and Lima (mixture of oxides SiO 2/Al 2O 3); deposition being achieved using an electron beam gun. The output results of the theoretical and experimental transmittance values for spectral band from 200 nm to 800 nm were discussed in four processes. To analyze the suitability for use in 'real world' applications, the test pieces were subjected to the durability tests (adhesion, abrasion resistance, and humidity) according to Military Standard MIL-C-675C and MIL-C-48497A.

  6. Lateral spreading of topically applied UV filter substances investigated by tape stripping.

    Science.gov (United States)

    Jacobi, U; Weigmann, H-J; Baumann, M; Reiche, A-I; Sterry, W; Lademann, J

    2004-01-01

    The lateral spreading of topically applied substances is a competitive process to the penetration into the stratum corneum (SC). The penetration of topically applied UV filter substances into the human SC and the lateral spreading were investigated in vivo. Tape stripping in combination with spectroscopic measurements was used to study both processes of two UV filter substances. The concentration of both UV filters was determined inside and outside the application area by varying the application and tape stripping protocol. A spreading of the topically applied substances from the treated to the untreated areas was observed, which caused a concentration gradient. This lateral spreading depends on the time between application and tape stripping and the size of the treated skin area. Significant amounts of topically applied substances were found adjoining the application area, due to the lateral spreading which takes place on the skin surface. In general, the lateral spreading must be considered to be a competitive process when studying penetration processes of topically applied substances. It has to be considered during drug treatment of small limited skin areas and for the interpretation of recovery rates obtained in penetration studies. Copyright 2004 S. Karger AG, Basel

  7. Occurrence, Distribution, and Fate of Organic UV Filters in Coral Communities.

    Science.gov (United States)

    Tsui, Mirabelle M P; Lam, James C W; Ng, T Y; Ang, P O; Murphy, Margaret B; Lam, Paul K S

    2017-04-18

    Organic ultraviolet (UV) filters are widely used in personal care products and occur ubiquitously in the aquatic environment. In this study, concentrations of seven commonly used organic UV filters were determined in seawater, sediment and five coral species collected from the eastern Pearl River Estuary of South China Sea. Five compounds, benzophenone-1, -3, and -8 (BP-1, -3, and -8), octocrylene (OC) and octyl dimethyl-p-aminobenzoic acid (ODPABA), were detected in the coral tissues with the highest detection frequencies (>65%) and concentrations (31.8 ± 8.6 and 24.7 ± 10.6 ng/g ww, respectively) found for BP-3 and BP-8. Significantly higher concentrations of BP-3 were observed in coral tissues in the wet season, indicating that higher inputs of sunscreen agents could be attributed to the increased coastal recreational activities. Accumulation of UV filters was only observed in soft coral tissues with bioaccumulation factors (log 10 -values) ranging from 2.21 to 3.01. The results of a preliminary risk assessment indicated that over 20% of coral samples from the study sites contained BP-3 concentrations exceeding the threshold values for causing larval deformities and mortality in the worst-case scenario. Higher probabilities of negative impacts of BP-3 on coral communities are predicted to occur in wet season.

  8. Occurrence of eight UV filters in beaches of Gran Canaria (Canary Islands). An approach to environmental risk assessment.

    Science.gov (United States)

    Sánchez Rodríguez, A; Rodrigo Sanz, M; Betancort Rodríguez, J R

    2015-07-01

    Due to the growing concern about human health effects of ultraviolet (UV) radiation, the use of UV filters has increased in recent decades. Unfortunately, some common UV filters are bioaccumulated in aquatic organisms and show a potential for estrogenic activity. The aim of the present study is to determine the presence of some UV filters in the coastal waters of six beaches around Gran Canaria Island as consequence of recreational seaside activities. Eight commonly used UV filters: benzophenone-3 (BP-3), octocrylene (OC), octyl-dimethyl-PABA (OD-PABA), ethylhexyl methoxy cinnamate (EHMC), homosalate (HMS), butyl methoxydibenzoyl methane (BMDBM), 4-methylbenzylidene camphor (4-MBC) and diethylamino hydroxybenzoyl hexyl benzoate (DHHB), were monitored and, with the exception of OD-PABA, all were detected in the samples collected. 99% of the samples showed some UV filters and concentration levels reached up to 3316.7 ng/L for BP-3. Environmental risk assessment (ERA) approach showed risk quotients (RQ) higher than 10, which means that there is a significant potential for adverse effects, for 4-MBC and EHMC for those samples with highest levels of UV filters. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. The development of a tunable, single-frequency ultraviolet laser source for UV filtered Rayleigh scattering

    Science.gov (United States)

    Finkelstein, N.; Gambogi, J.; Lempert, Walter R.; Miles, Richard B.; Rines, G. A.; Finch, A.; Schwarz, R. A.

    1995-01-01

    We present the development of a flexible, high power, narrow line width, tunable ultraviolet source for diagnostic application. By frequency tripling the output of a pulsed titanium-sapphire laser, we achieve broadly tunable (227-360 nm) ultraviolet light with high quality spatial and spectral resolution. We also present the characterization of a mercury vapor cell which provides a narrow band, sharp edge absorption filter at 253.7 nm. These two components form the basis for the extension of the Filtered Rayleigh Scattering technique into the ultraviolet. The UV-FRS system is comprised of four pieces: a single frequency, cw tunable Ti:Sapphire seeding source; a high-powered pulsed Ti:Sapphire oscillator; a third harmonic generator system; and an atomic mercury vapor filter. In this paper we discuss the development and characterization of each of these elements.

  10. Deep-UV Based Acousto-Optic Tunable Filter for Spectral Sensing Applications

    Science.gov (United States)

    Prasad, Narasimha S.

    2006-01-01

    In this paper, recent progress made in the development of quartz and KDP crystal based acousto-optic tunable filters (AOTF) are presented. These AOTFs are developed for operation over deep-UV to near-UV wavelengths of 190 nm to 400 nm. Preliminary output performance measurements of quartz AOTF and design specifications of KDP AOTF are presented. At 355 nm, the quartz AOTF device offered approx.15% diffraction efficiency with a passband full-width-half-maximum (FWHM) of less than 0.0625 nm. Further characterization of quartz AOTF devices at deep-UV wavelengths is progressing. The hermetic packaging of KDP AOTF is nearing completion. The solid-state optical sources being used for excitation include nonlinear optics based high-energy tunable UV transmitters that operate around 320 nm and 308 nm wavelengths, and a tunable deep-UV laser operating over 193 nm to 210 nm. These AOTF devices have been developed as turn-key devices for primarily for space-based chemical and biological sensing applications using laser induced Fluorescence and resonance Raman techniques.

  11. Effects of the UV filter benzophenone-2 on reproduction in fish

    International Nuclear Information System (INIS)

    Weisbrod, Christin J.; Kunz, Petra Y.; Zenker, Armin K.; Fent, Karl

    2007-01-01

    The UV filter benzophenone-2 (BP-2) is largely used in personal care products such as cosmetics and in numerous other materials for UV protection. Like other UV filters, BP-2 has been found to be estrogenic in vitro and in vivo, but potential effects on reproduction of fish are unknown. In this study, we evaluate whether BP-2 affects important reproductive parameters such as fecundity, gametogenesis and secondary sex characteristics. After a pre-exposure period of 19 days, reproductively mature fathead minnows (Pimephales promelas) were exposed to 0.002, 0.1, 1.2, 5.0 and 9.7 mg/L BP-2 for 15 days. BP-2 was accumulated in fish up to 3.1 μg/g body weight. In males, a dose-dependent vitellogenin induction and decrease in the number of nuptial tubercles occurred. Moreover, significant dose-related effects on gonads of male and female fish were observed. At concentrations of 1.2 mg/L and higher, spermatocyte and oocyte development was significantly inhibited in male and female fish, respectively. Testes of exposed males had much fewer spermatocytes and ovaries of exposed females had much fewer mature and more atretic follicles. Reproduction was negatively affected in a dose-dependent manner with a decrease in egg production at 5.0 mg/L and a complete cessation of spawning activity at 9.7 mg/L BP-2. Our findings show significant estrogenic effects of the common UV filter BP-2 on vitellogenin induction, secondary sex characteristics, gonadal development, and reproduction in fish

  12. In the shadow of the Cosmetic Directive--inconsistencies in EU environmental hazard classification requirements for UV-filters.

    Science.gov (United States)

    Sobek, A; Bejgarn, S; Rudén, C; Molander, L; Breitholtz, M

    2013-09-01

    UV-filters are chemicals with potentially environmental hazardous properties. In the European Union (EU), UV-filters contained in sunscreen products are currently regulated by the Cosmetic Directive (from July 2013 by the Cosmetic Products Regulation). Environmental hazard classifications according to the regulation on classification, labelling and packaging of substances and mixtures (CLP) must be determined for UV-filters contained in industrial chemical products, whereas UV-filters contained in sunscreens are exempted from CLP. In this study we determined the potential environmental hazard classifications of UV-filters and sunscreen products if the CLP regulation was to be required for cosmetic products. Two sunscreen products were evaluated in accordance with the aquatic environmental hazard criteria for mixtures. The results highlight that the inconsistencies in the current EU regulation of UV filters hamper the risk management of environmental hazards of UV filters used in cosmetic products. Almost 50% of the investigated UV-filters approved for use in cosmetic products on the European market according to the current Cosmetic Directive were identified to meet the CLP classification as being hazardous to the aquatic environment. Assuming a worst-case scenario, the two examined sunscreens could both be classified as hazardous to the aquatic environment with long-lasting effects according to CLP classification criteria. Hence, if the CLP regulation was applicable to sunscreen products, both brands could potentially be labelled with the environmental hazard pictogram and associated hazard and precautionary statements. Including cosmetic products, and thereby sunscreens, in the CLP regulation would contribute to a more harmonized and transparent regulation of potentially hazardous substances on the EU market. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Reactive low temperature plasma ionization mass spectrometry for the determination of organic UV filters in personal care products.

    Science.gov (United States)

    Ding, Xuelu; Gerbig, Stefanie; Spengler, Bernhard; Schulz, Sabine

    2018-02-01

    Organic UV filters in personal care products (PCPs) have been persistently reported as a potential threat to human health. In order to guarantee consumers ' safety, the dose of these compounds in PCPs needs to be monitored. Here, a methodology based on reactive low temperature plasma ionization (LTP) mass spectrometry (MS) has been developed for the determination of common organic UV filters in PCPs including benzophenone-3, ethylhexyl dimethyl p-aminobenzoic acid, ethylhexyl methoxycinnamate, 4-methylbenzylidene camphor, octocrylene, and ethylhexyl salicylate. The experiments were carried out in transmission geometry where the LTP ion source, samples loaded on a stainless steel mesh, and the MS inlet were aligned coaxially. Four chemicals, ammonia, ammonium formate, aniline, and methylamine were considered as reactive additives allowing reactions with the UV filters through different mechanisms. Methylamine-induced reactive LTP-MS showed the most prominent improvement on the detection of UV filter compounds. Compared to direct LTP-MS, the developed method improved the detection limits of UV filters more than 10 fold. Moreover, the method enabled fast semi-quantitative screening of UV filters in authentic PCPs. Concentrations of active ingredients in eight authentic PCPs as determined with reactive LTP-MS were found comparable to values offered by the cosmetic companies and corresponding HPLC data. The methodology provides high throughput analysis (70s per sample) and sensitive identification of organic UV filters. Lowest detectable concentrations ranged from 0.13µg/g for 4-methylbenzylidene camphor to 7.67µg/g for octocrylene in spiked cream. In addition, it shows the potential to be used as a screening tool for legal authentications of these chemicals in the future due to its semi-quantitative determination of UV filters in PCPs without tedious sample preparation and time-consuming chromatographic separation. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. UV filters are an environmental threat in the Gulf of Mexico: a case study of Texas coastal zones

    Directory of Open Access Journals (Sweden)

    Hamidreza Sharifan

    2016-10-01

    Full Text Available UV filters are the main ingredients in many cosmetics and personal care products. A significant amount of lipophilic UV filters annually enters the surface water due to large numbers of swimmers and sunbathers. The nature of these compounds cause bioaccumulation in commercial fish, particularly in estuarine areas. Consequently, biomagnification in the food chain will occur. This study estimated the amount of four common UV filters (ethylhexyl methoxycinnamate, EHMC; octocrylene, OC; butyl methoxydibenzoylmethane, BM-DBM; and benzophenone-3, BP3, which may enter surface water in the Gulf of Mexico. Our data analysis was based on the available research data and EPA standards (age classification/human body parts. The results indicated that among the 14 counties in Texas coastal zones, Nueces, with 43 beaches, has a high potential of water contamination through UV filters; EHMC: 477 kg year−1; OC: 318 kg year−1; BM-DBM: 258 kg year−1; and BP by 159 kg year−1. Refugio County, with a minimum number of beaches, indicated the lowest potential of UV filter contamination. The sensitive estuarine areas of Galveston receive a significant amount of UV filters. This article suggests action for protecting Texas estuarine areas and controlling the number of tourists and ecotourism that occurs in sensitive areas of the Gulf of Mexico.

  15. Efficiency and mass loading characteristics of a typical HEPA filter media material

    International Nuclear Information System (INIS)

    Novick, V.J.; Higgins, P.J.; Dierkschiede, B.; Abrahamson, C.; Richardson, W.B.; Monson, P.R.; Ellison, P.G.

    1991-01-01

    The particle removal efficiency of the high-efficiency particulate air (HEPA) filter material used at the Savannah River Site was measured as a function of monodisperse particle diameter and two gas filtration velocities. the results indicate that the material meets or exceeds the minimum specified efficiency of 99.97% for all particle diameters at both normal and minimum operating flow conditions encountered at the Savannah River site. The pressure drop across the HEPA filter material used at the Savannah River site was measured as a function of particle mass loading for various aerosol size distributions. The pressure drop was found to increase linearly with the particle mass loaded onto the filters, as long as the particles were completely dry. The slope of the curve was found to be dependent on the particle diameter and velocity of the aerosol. The linear behavior between the initial pressure drop (clean filter) and the final pressure drop (loaded filter) implies that the filtration mechanism is dominated by the particle cake that rapidly forms on the front surface of the HEPA filter. This behavior is consistent with the high filtration efficiency of the material

  16. The effect of UV-filters on the viability of neuroblastoma (SH-SY5Y) cell line.

    Science.gov (United States)

    Broniowska, Żaneta; Pomierny, Bartosz; Smaga, Irena; Filip, Małgorzata; Budziszewska, Bogusława

    2016-05-01

    Topical application of cosmetic products, containing ultraviolet filters (UV filters) are recommended as a protection against sunburns and in order to reduce the risk of skin cancer. However, some UV filters can be absorbed through skin and by consuming contaminated food. Among the chemical UV filters, benzophenone-3 (BP-3), 3-(4-methylbenzylidene)camphor (4-MBC) and 2-ethylhexyl-4-methoxycinnamate (OMC) are absorbed through the skin to the greatest extent. So far, these lipophilic compounds were demonstrated to influence the gonadal and thyroid hormone function, but their effect on central nervous system cells has not been investigated, yet. In the present study, we investigated the effect of some UV filters on cell viability and caspase-3 activity in SH-SY5Y cells. It has been found that benzophenone-2 (BP-2), BP-3, 4-methylbenzophenone (4-MBP) and OMC present in the culture medium for 72h in high concentration (10(-5) and 10(-4)M) and 4-MBC only 10(-4)M produced a significant cytotoxic effect, as determined both by the MTT reduction test and LDH release assay. In contrast to necrotic changes, all tested UV filters increased caspase-3 activity in much lower concentrations (from 10(-8) to 10(-7)M). Proapoptotic properties of the test compounds were positively verified by Hoechst staining. The obtained results indicated that UV filters adversely affected the viability of nerve cells, most likely by enhancing the process of apoptosis. The most potent effect was exerted by BP-3 and 4-MBC and at concentrations that may be reached in vivo. Since human exposure to UV filters is significant these compound should be taken into consideration as one of the possible factors involved in pathogenesis of neurodegenerative diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Estrogenic activity of ternary UV filter mixtures in fish (Pimephales promelas) - An analysis with nonlinear isobolograms

    International Nuclear Information System (INIS)

    Kunz, Petra Y.; Fent, Karl

    2009-01-01

    Numerous estrogenic compounds are present in aquatic environments, but currently it is not well understood how compounds that differ in maxima and slope of their individual dose-response curves contribute to the overall mixture effect. In order to better understand such interactions we investigated 3 commonly used UV filters, for their estrogenic mixture activity and analysed their joint effects by using the concentration addition (CA) concept. Thereby, we extended the method of isoboles for analysis of 3 compounds that differ in maxima and slopes of their dose-response curves. 3-Benzylidene camphor (3BC), benzophenone-1 (BP1) and benzophenone-2 (BP2) are estrogenic in fish and act as pure- or partial estrogen receptor α agonists. First we exposed juvenile fathead minnows for 14 days to six concentrations of each UV filter alone to determine vitellogenin (VTG) induction curves, calculate equi-effective mixture concentrations and predict mixture effects. For 3BC, BP1 and BP2 significant VTG-induction occurred at 420, 2668, and 4715 μg/L, respectively. BP2 displayed a full dose-response curve, whereas 3BC and BP1 showed submaximal activity of 70 and 78%, respectively. Second, we exposed fish to 6 equi-effective mixtures (EC-NOEC, EC1, EC5, EC10, EC20, EC30) of these UV filters. Significant VTG-induction occurred at EC5 and higher. Submaximal activity of 67% as compared to the control EE2 (100 ng/L) was reached. The curves for the observed and predicted mixture activity agreed for mixture levels (EC10 to EC30), however, at EC-NOEC, EC1 and EC5, lower activity was observed than predicted by CA. Detailed isobolographic analysis indicate additivity at EC10 to EC30, and antagonism at low levels (EC-NOEC to EC5). Our data show for the first time, that for compounds with differences in maxima and slope, considerably more mixture combinations are additive than previously thought. This should be taken into account for hazard and risk assessment of UV filters and

  18. Occurrence and toxicity of musks and UV filters in the marine environment.

    Science.gov (United States)

    S, Rainieri; A, Barranco; M, Primec; T, Langerholc

    2017-06-01

    Emerging chemical contaminants in the marine ecosystem represent a threat to the environment and also to human health due to insufficient knowledge about their toxicity and bioaccumulation in the food chain. Consequently, many of them are not regulated. In this review we focus on musks and organic UV filters. For both groups of compounds we describe occurrence in the marine environment, toxic effects identified so far and methods used to identify such effects. The final objective of this work is to identify gaps in the understanding of their toxicology. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Maternal exposure to UV filters: associations with maternal thyroid hormones, IGF-I/IGFBP3 and birth outcomes.

    Science.gov (United States)

    Krause, M; Frederiksen, H; Sundberg, K; Jørgensen, F S; Jensen, L N; Nørgaard, P; Jørgensen, C; Ertberg, P; Petersen, J H; Feldt-Rasmussen, U; Juul, A; Drzewiecki, K T; Skakkebaek, N E; Andersson, A M

    2018-02-01

    Several chemical UV filters/absorbers ('UV filters' hereafter) have endocrine-disrupting properties in vitro and in vivo . Exposure to these chemicals, especially during prenatal development, is of concern. To examine maternal exposure to UV filters, associations with maternal thyroid hormone, with growth factor concentrations as well as to birth outcomes. Prospective study of 183 pregnant women with 2nd trimester serum and urine samples available. Maternal concentrations of the chemical UV filters benzophenone-1 (BP-1) and benzophenone-3 (BP-3) in urine and 4-hydroxy-benzophenone (4-HBP) in serum were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The relationships between 2nd trimester maternal concentrations of the three chemical UV filters and maternal serum concentrations of thyroid hormones and growth factors, as well as birth outcomes (weight, height, and head and abdominal circumferences) were examined. Positive associations between maternal serum concentrations of 4-HBP and triiodothyronine (T 3 ), thyroxine (T 4 ), insulin-like growth factor I (IGF-I) and its binding protein IGFBP3 were observed in mothers carrying male fetuses. Male infants of mothers in the middle 4-HBP exposure group had statistically significantly lower weight and shorter head and abdominal circumferences at birth compared to the low exposure group. Widespread exposure of pregnant women to chemical UV filters and the possible impact on maternal thyroid hormones and growth factors, and on fetal growth, calls for further studies on possible long-term consequences of the exposure to UV filters on fetal development and children's health. © 2018 The authors.

  20. Single- and mixture toxicity of three organic UV-filters, ethylhexyl methoxycinnamate, octocrylene, and avobenzone on Daphnia magna.

    Science.gov (United States)

    Park, Chang-Beom; Jang, Jiyi; Kim, Sanghun; Kim, Young Jun

    2017-03-01

    In freshwater environments, aquatic organisms are generally exposed to mixtures of various chemical substances. In this study, we tested the toxicity of three organic UV-filters (ethylhexyl methoxycinnamate, octocrylene, and avobenzone) to Daphnia magna in order to evaluate the combined toxicity of these substances when in they occur in a mixture. The values of effective concentrations (ECx) for each UV-filter were calculated by concentration-response curves; concentration-combinations of three different UV-filters in a mixture were determined by the fraction of components based on EC 25 values predicted by concentration addition (CA) model. The interaction between the UV-filters were also assessed by model deviation ratio (MDR) using observed and predicted toxicity values obtained from mixture-exposure tests and CA model. The results from this study indicated that observed ECx mix (e.g., EC 10mix , EC 25mix , or EC 50mix ) values obtained from mixture-exposure tests were higher than predicted ECx mix (e.g., EC 10mix , EC 25mix , or EC 50mix ) values calculated by CA model. MDR values were also less than a factor of 1.0 in a mixtures of three different UV-filters. Based on these results, we suggest for the first time a reduction of toxic effects in the mixtures of three UV-filters, caused by antagonistic action of the components. Our findings from this study will provide important information for hazard or risk assessment of organic UV-filters, when they existed together in the aquatic environment. To better understand the mixture toxicity and the interaction of components in a mixture, further studies for various combinations of mixture components are also required. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Advances in analytical methods and occurrence of organic UV-filters in the environment--A review.

    Science.gov (United States)

    Ramos, Sara; Homem, Vera; Alves, Arminda; Santos, Lúcia

    2015-09-01

    UV-filters are a group of compounds designed mainly to protect skin against UVA and UVB radiation, but they are also included in plastics, furniture, etc., to protect products from light damage. Their massive use in sunscreens for skin protection has been increasing due to the awareness of the chronic and acute effects of UV radiation. Some organic UV-filters have raised significant concerns in the past few years for their continuous usage, persistent input and potential threat to ecological environment and human health. UV-filters end up in wastewater and because wastewater treatment plants are not efficient in removing them, lipophilic compounds tend to sorb onto sludge and hydrophilics end up in river water, contaminating the existing biota. To better understand the risk associated with UV-filters in the environment a thorough review regarding their physicochemical properties, toxicity and environmental degradation, analytical methods and their occurrence was conducted. Higher UV-filter concentrations were found in rivers, reaching 0.3mg/L for the most studied family, the benzophenone derivatives. Concentrations in the ng to μg/L range were also detected for the p-aminobenzoic acid, cinnamate, crylene and benzoyl methane derivatives in lake and sea water. Although at lower levels (few ng/L), UV-filters were also found in tap and groundwater. Swimming pool water is also a sink for UV-filters and its chlorine by-products, at the μg/L range, highlighting the benzophenone and benzimidazole derivatives. Soils and sediments are not frequently studied, but concentrations in the μg/L range have already been found especially for the benzophenone and crylene derivatives. Aquatic biota is frequently studied and UV-filters are found in the ng/g-dw range with higher values for fish and mussels. It has been concluded that more information regarding UV-filter degradation studies both in water and sediments is necessary and environmental occurrences should be monitored more

  2. Size-Resolved Penetration Through High-Efficiency Filter Media Typically Used for Aerosol Sampling

    Czech Academy of Sciences Publication Activity Database

    Zíková, Naděžda; Ondráček, Jakub; Ždímal, Vladimír

    2015-01-01

    Roč. 49, č. 4 (2015), s. 239-249 ISSN 0278-6826 R&D Projects: GA ČR(CZ) GBP503/12/G147 Institutional support: RVO:67985858 Keywords : filters * size-resolved penetration * atmospheric aerosol sampling Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.953, year: 2015

  3. UV filters analyzed by isotope diluted TurboFlow-LC-MS/MS in urine from Danish children and adolescents.

    Science.gov (United States)

    Frederiksen, Hanne; Nielsen, Ole; Skakkebaek, Niels E; Juul, Anders; Andersson, Anna-Maria

    2017-03-01

    Experimental studies indicate that some chemicals with UV blocking properties (known as UV filters) can act as endocrine disruptors. UV filters are used in sunscreens and other cosmetic- and personal care products, as well as in other consumer products such as food packaging, clothing and furniture textiles to protect the products against UV radiation. Here we present the urinary excretion of suspected endocrine active UV filters in Danish children and adolescents recruited from the general population. The content of benzophenone (BP), benzophenone-1 (BP-1), benzophenone-2 (BP-2), benzophenone-3 (BP-3), 5-chloro-2- hydroxybenzophenone (BP-7), 4-hydroxybenzophenone (4-HBP), 4-methyl-benzophenone (4-MBP), 3-(4- methylbenzylidene)-camphor (4-MBC) and 3-benzylidene camphor (3-BC) were monitored in 24h urine and two consecutive first morning samples from 129 healthy Danish children and adolescents (6-21 yrs). All 387 samples were collected during the autumn (Nov. 2007) and were analyzed by a new on-line TurboFlow-LC-MS/MS method developed for simultaneous biomonitoring of these nine UV filters in urine. BP-3 and BP-1 were detected in more than 80% of the 24h samples and were significantly correlated (R 2 =0.815). BP, 4-HBP and BP-2 were found in 43, 15 and 5% of the samples, respectively. The median (range) concentrations of the UV-filters in 24-h urine were as follows: BP-3, 0.92 (LOD-115); BP-1, 0.54 (LOD-44.6); BP,UV filters; BP-7, 4-MBP, 4-MBC or 3-BC were detected in urine. A highly significant correlation between first morning and 24h urine levels of BP-3, BP-1 and 4-HBP from the same day was observed. Our project on UV filters analyzed by a new robust and sensitive LC-MS/MS method in Danish children and adolescents showed that almost all individuals were exposed to UV filters. Sun protection products have been claimed to be a major source of exposure to sunscreens. However since all children in the present study were exposed during autumn where sunscreens are not

  4. Detection of emerging contaminants (UV filters, UV stabilizers and musks) in marine mussels from Portuguese coast by QuEChERS extraction and GC-MS/MS.

    Science.gov (United States)

    Picot Groz, M; Martinez Bueno, M J; Rosain, D; Fenet, H; Casellas, C; Pereira, C; Maria, V; Bebianno, M J; Gomez, E

    2014-09-15

    The UV filters and musk fragrances have come into focus because these compounds are contained and increasingly used not only in sunscreen products but also in many products of daily use, such as cosmetics, skin creams, plastics or varnish. In view of this, the main objective of the present work was to develop and validate a method for the determination of three UV filters, two UV stabilizers and four musks in mussel samples (Mytilus galloprovincialis). The procedure combined a QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction method with an analysis by gas chromatography-tandem mass spectrometry (GC-MS/MS). The methodology allowed the determination of target analytes at trace concentration levels (ng/g), with mean recoveries ranging from 91 to 112%. A monitoring study was conducted in four beaches in the Portuguese coast which are impacted by recreational activities and outflow of treated waste water effluents in rivers. The results are used to assess the occurrence of UV filters in comparison with UV stabilizers and musk fragrances which indicate other activities than bathing. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. UV filters interaction in the chlorinated swimming pool, a new challenge for urbanization, a need for community scale investigations.

    Science.gov (United States)

    Sharifan, Hamidreza; Klein, David; Morse, Audra N

    2016-07-01

    Sunscreen products and some personal care products contain the Ultraviolet (UV) chemical filters, which are entering the surface water. Public concerns about secondary effects of these compounds are growing because of the contamination of the aquatic environment that may reach to potentially toxic concentration levels. This article highlights the reaction of certain UV filters with hypochlorite disinfectant in the presence of sunlight. Due to urbanization and industrialization, use of outdoor plastic swimming pools is increasing. The relatively smaller volume of these pools compared to larger pools may increase the concentration of the UV filters in the pool and their potential interactions with materials of human origin (urine, sweat, cosmetics, skin cells, and hair) to the levels of toxicity concerns for children through the creation of disinfection by products (DBP). Based on our analysis, the minimum concentration levels of 2.85, 1.9, 1.78 and 0.95g/L, respectively, for EHMC, OC, 4-MBC and BP3 UV filters in children pools are predicted. Therefore, this article calls for an urgent investigation of potential toxic effects of the UV filters, the creation of DBPs and their subsequent impacts on human health. Published by Elsevier Inc.

  6. Benzophenone-type UV filters in surface waters: An assessment of profiles and ecological risks in Shanghai, China.

    Science.gov (United States)

    Wu, Ming-Hong; Xie, Deng-Guo; Xu, Gang; Sun, Rui; Xia, Xiao-Yu; Liu, Wen-Long; Tang, Liang

    2017-07-01

    Benzophenone-type UV filters (BP-UV filters) are frequently introduced into aquatic environment from several sources. The occurrence and fate of select BP-UV filters and their metabolites were investigated in this study. All target compounds were detected in water samples, except for 2, 3, 4-trihydroxybenzophenone (2, 3, 4-OH-BP). The concentration reached up 131ngL -1 for 5-benzoyl-4-hydroxy-2-ethoxybenzenesulfonic acid (BP-4), 30.0ngL -1 for 2-hydroxy-4-methoxybenzophenone (BP-3), and mean value of 158ngL -1 for benzophenone (BP). Concentrations of BP-UV filters were not related to recreational waters but with high population frequencies. In addition, five BP-UV filters, namely 2,2',4,4'-tetrahydroxybenzophenone (BP-2), 2,3,4-OH-BP, 2,4-dihydroxybenzophenone (BP-1), 4-hydroxybenzophenone (4-OH-BP) and BP were investigated for probable sources, and found that they originate from BP-3 metabolism. There is a similar source for BP-3, BP-4, BP-1, 4-OH-BP and BP. Environmental risk assessment (ERA) showed that risk quotients (RQs) of BP-4, BP-3 and BP were 2.7, 0.8 and 0.5, respectively. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Occurrence, distribution and ecological risk assessment of multiple classes of UV filters in surface waters from different countries.

    Science.gov (United States)

    Tsui, Mirabelle M P; Leung, H W; Wai, Tak-Cheung; Yamashita, Nobuyoshi; Taniyasu, Sachi; Liu, Wenhua; Lam, Paul K S; Murphy, Margaret B

    2014-12-15

    Organic UV filters are common ingredients of personal care products (PCPs), but little is known about their distribution in and potential impacts to the marine environment. This study reports the occurrence and risk assessment of twelve widely used organic UV filters in surface water collected in eight cities in four countries (China, the United States, Japan, and Thailand) and the North American Arctic. The number of compounds detected, Hong Kong (12), Tokyo (9), Bangkok (9), New York (8), Los Angeles (8), Arctic (6), Shantou (5) and Chaozhou (5), generally increased with population density. Median concentrations of all detectable UV filters were UV filter levels in Hong Kong. In general, spatial patterns varied with sampling month and all compounds showed higher concentrations in the wet season except benzophenone-4 (BP-4). Probabilistic risk assessment showed that 4-methylbenzylidene camphor (4-MBC) posed greater risk to algae, while benzophenone-3 (BP-3) and ethylhexyl methoxycinnamate (EHMC) were more likely to pose a risk to fishes and also posed high risk of bleaching in hard corals in aquatic recreational areas in Hong Kong. This study is the first to report the occurrence of organic UV filters in the Arctic and provides a wider assessment of their potential negative impacts in the marine environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Occurrence, distribution and ecological risk assessment of multiple classes of UV filters in marine sediments in Hong Kong and Japan.

    Science.gov (United States)

    Tsui, Mirabelle M P; Leung, H W; Kwan, Billy K Y; Ng, Ka-Yan; Yamashita, Nobuyoshi; Taniyasu, Sachi; Lam, Paul K S; Murphy, Margaret B

    2015-07-15

    Organic ultraviolet (UV) filters are used widely in various personal care products and their ubiquitous occurrence in the aquatic environment has been reported in recent years. However, data on their fate and potential impacts in marine sediments is limited. This study reports the occurrence and risk assessment of eleven widely used organic UV filters in marine sediment collected in Hong Kong and Tokyo Bay. Seven of the 11 target UV filters were detected in all sediment samples (median concentrations: UV filter occurrence; this was likely due to their relatively higher octanol-water partition coefficients. Probabilistic ecological risk assessment showed that the likelihood of EHMC causing toxic effects on reproduction in snails was over 84% and 32% based on toxicity data for two species, respectively, suggesting potential risks of UV filters to benthic organisms and possible wider effects on the marine food web. However, more toxicity data for sediment organisms is necessary for better risk assessment of these compounds in benthic communities. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. The UV filtering potential of drop-casted layers of frustules of three diatom species

    DEFF Research Database (Denmark)

    Su, Yanyan; Lenau, Torben Anker; Gundersen, Emil

    2018-01-01

    Diatoms are in focus as biological materials for a range of photonic applications. Many of theseapplications would require embedding a multitude of diatoms in a matrix (e.g. paint, crème or lacquer); however, most studies on the photonic and spectral properties of diatoms frustules (silica walls)...... performance of layers of diatom frustules is of central relevance for their potential use as innovative bio-based UV filters.......) havebeen carried out on single cells. In this study, for the first time, we test the spectral properties of layersof frustules of three diatom species (Coscinodiscus granii, Thalassiosira punctifera and Thalassiosira pseudonana), with special focus on transmission and reflectance in the UV range....... The transmittance efficiency in the UV A and B range was: T. pseudonana (56–59%) >C. granii (53–54%) >T. punctifera (18–21%) for the rinsed frustules. To investigate the underlying cause of these differences, we performed X-ray scattering analysis, measurement of layer thickness and microscopic determination...

  10. UV filters analyzed by isotope diluted TurboFlow-LC-MS/MS in urine from Danish children and adolescents

    DEFF Research Database (Denmark)

    Frederiksen, Hanne; Nielsen, Ole; Skakkebaek, Niels E

    2017-01-01

    between first morning and 24h urine levels of BP-3, BP-1 and 4-HBP from the same day was observed. CONCLUSION: Our project on UV filters analyzed by a new robust and sensitive LC-MS/MS method in Danish children and adolescents showed that almost all individuals were exposed to UV filters. Sun protection...... and adolescents (6-21 yrs). All 387 samples were collected during the autumn (Nov. 2007) and were analyzed by a new on-line TurboFlow-LC-MS/MS method developed for simultaneous biomonitoring of these nine UV filters in urine. RESULTS: BP-3 and BP-1 were detected in more than 80% of the 24h samples and were...

  11. ZnO nanoparticles and organic chemical UV-filters are equally well tolerated by human immune cells.

    Science.gov (United States)

    O'Keefe, Sean J; Feltis, Bryce N; Piva, Terrence J; Turney, Terence W; Wright, Paul F A

    2016-11-01

    An important part of assessing the toxic potential of nanoparticles for specific applications should be the direct comparison of biological activities with those of alternative materials for the same application. Nanoparticulate inorganic ultraviolet (UV) filters, such as zinc oxide (ZnO), are commonly incorporated into transparent sunscreen and cosmetic formulations. However, concerns have been raised about potential unwanted effects, despite their negligible skin penetration and inherent advantages over organic chemical UV-filters. To provide useful application-relevant assessments of their potential hazard with/without UVA co-exposure, we directly compared cytotoxic and immune response profiles of human THP-1 monocytic cells to ZnO nanoparticles (30 nm) with bulk ZnO particulates (200 nm) and five conventional organic chemical UV-filters - butylmethoxydibenzoylmethane (avobenzone), octylmethoxycinnamate, octylsalicylate, homosalate and 4-methylbenzylidene camphor. High exposure concentrations of both organic and particulate UV-filters were required to cause cytotoxicity in monocyte and macrophage cultures after 24 h. Co-exposure with UVA (6.7 J/cm(2)) did not alter cytotoxicity profiles. Particle surface area-based dose responses showed that ZnO NPs were better tolerated than bulk ZnO. Organic and particulate UV-filters increased apoptosis at similar doses. Only particulates increased the generation of reactive oxygen species. Interleukin-8 (IL-8) release was increased by all particulates, avobenzone, homosalate and octylsalicylate. IL-1β release was only increased in macrophages by exposure to avobenzone and homosalate. In conclusion, direct effects were caused in monocytes and macrophages at similar concentrations of both organic UV-filters and ZnO nanoparticulates - indicating that their intrinsic cytotoxicity is similar. With their lower skin penetration, ZnO nanoparticles are expected to have lower bioactivity when used in sunscreens.

  12. Synthesis of New 2-(2´-Hydroxyarylbenzotriazoles and Evaluation of Their Photochemical Behavior as Potential UV-Filters

    Directory of Open Access Journals (Sweden)

    Lajos Novak

    2010-09-01

    Full Text Available Two new 2-(2´-hydroxyarylbenzotriazole derivatives were synthesized and studied by photophysical and photochemical techniques in order to assess their ability to act as UV-filters. The absorption and emission properties of both compounds were determined in solvents of different polarity. In non polar solvent, a photoinduced excited state intramolecular proton transfer was established leading to efficient non radiative dissipation of UV-energy. In addition, the compounds considered were photostable under irradiation with simulated sunlight.

  13. Multifunctional Moth-Eye TiO2/PDMS Pads with High Transmittance and UV Filtering.

    Science.gov (United States)

    Jang, Segeun; Kang, Seong Min; Choi, Mansoo

    2017-12-20

    This work reports a facile fabrication method for constructing multifunctional moth-eye TiO 2 /polydimethylsiloxane (PDMS) pads using soft nano-imprinting lithography and a gas-phase-deposited thin sacrificial layer. Mesoporous TiO 2 nanoparticles act as an effective UV filter, completely blocking high-energy UVB light and partially blocking UVA light and forming a robust TiO 2 /PDMS composite pad by allowing the PDMS solution to easily fill the porous TiO 2 network. The paraboloid-shaped moth-eye nanostructures provided high transparency in the visible spectrum and also have self-cleaning effects because of nanoroughness on the surface. Furthermore, we successfully achieved a desired multiscale-patterned surface by partially curing select regions using TiO 2 /PDMS pads with partial UVA ray blockers. The ability to fabricate multifunctional polymeric pads is advantageous for satisfying increasing demands for flexible and wearable electronics, displays, and solar cells.

  14. Synthesis and evaluation of octocrylene-inspired compounds for UV-filter activity

    Directory of Open Access Journals (Sweden)

    Hudson C. Polonini

    2014-07-01

    Full Text Available Octocrylene (2-ethylhexyl 2-cyano-3,3-diphenyl-2-propenoate is present in several sunscreens and is known to work synergistically with UV filters. We prepared eight octocrylene-related compounds to test their photoprotective activities by measuring diffuse transmittance. The compounds had varied photoprotection profiles, with Sun Protection Factors (SPF ranging from 1 to 5 and UVA Protection Factors (UVAPF ranging from 1 to 8. Compounds 4, 5, and 7 showed the best protection against UVB sunrays, while compounds 5, 6, and 7 presented the best results for protection from UVA, so compound 7 had the most balanced protection overall. Results for compounds 4, 8, and 9 are reported for the first time in the literature.

  15. UV Filtering of Dye-Sensitized Solar Cells: The Effects of Varying the UV Cut-Off upon Cell Performance and Incident Photon-to-Electron Conversion Efficiency

    Directory of Open Access Journals (Sweden)

    Matthew Carnie

    2012-01-01

    Full Text Available With current technology, UV filters are essential to ensure long-term dye-sensitized solar cell (DSC stability. Blocking photons, however, will have an obvious effect on device performance and upon its incident photon-to-current conversion efficiency (IPCE. Filters have been applied to DSC devices with a range of cut-off wavelengths in order to assess how different levels of filtering affect the performance and IPCE of devices made with three different dyes, namely N719, Z907, and N749. It is shown that dyes that extend their IPCE further into the NIR region suffer lesser relative efficiency losses due to UV filtering than dyes with narrower action spectra. Furthermore, the results are encouraging to those working towards the industrialisation of DSC technology. From the results presented it can be estimated that filtering at a level intended to prevent direct band gap excitation of the TiO2 semiconductor should cause a relative drop in cell efficiency of no more than 10% in forward illuminated devices and no more than 2% in reverse illuminated devices.

  16. Pollution patterns and underlying relationships of benzophenone-type UV-filters in wastewater treatment plants and their receiving surface water.

    Science.gov (United States)

    Wu, Ming-Hong; Li, Jian; Xu, Gang; Ma, Luo-Dan; Li, Jia-Jun; Li, Jin-Song; Tang, Liang

    2018-05-15

    The environmental behaviors of emerging pollutants, benzophenone-type UV filters (BP-UV filters) and their derivatives were investigated in four wastewater treatment plants (WWTPs), and their receiving surface waters in Shanghai. The concentration level of selected BP-UV filters in the WWTPs was detected from ngL -1 to μgL -1 . BP (621-951ngL -1 ) and BP-3 (841-1.32 × 10 3 ngL -1 ) were the most abundant and highest detection frequency individuals among the target BP-UV filters in influents, whereas BP (198-400ngL -1 ), BP-4 (93.3-288ngL -1 ) and BP-3 (146-258ngL -1 ) were predominant in effluents. BP-UV filters cannot be completely removed and the total removal efficiency varied widely (-456% to 100%) during the treatment process. It can be inferred that the usage of BP and BP-3 are higher than other BP-UV filters in the study area. The lowest and highest levels were BP-2 (ND-7.66ngL -1 ) and BP-3 (68.5-5.01 × 10 3 ng L -1 ) in the receiving surface water, respectively. Interestingly, the seasonal variation of BP-3 is larger than those of other BP-UV filters in surface water from Shanghai. There is no obvious pollution pattern of BP-UV filters in the surface water from the cosmetic factory area. The correlation analysis of BP-UV filters between WWTPs effluents and nearby downstream water samples suggested that BP-UV filters emitted from some WWTPs might be the main source of receiving surface water. Preliminary risk assessment indicated that the levels of BP-UV filters detected by the effluent posed medium to high risk to fish as well as other aquatic organisms. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Effects of the UV filter benzophenone-3 (oxybenzone) at low concentrations in zebrafish (Danio rerio)

    Energy Technology Data Exchange (ETDEWEB)

    Blüthgen, Nancy [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH‐4132 Muttenz (Switzerland); University of Basel, Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, Klingelbergstrasse 50, CH-4056 Basel (Switzerland); Zucchi, Sara [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH‐4132 Muttenz (Switzerland); Fent, Karl, E-mail: karl.fent@fhnw.ch [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH‐4132 Muttenz (Switzerland); Swiss Federal Institute of Technology (ETHZ), Department of Environmental Sciences, CH‐8092 Zürich (Switzerland)

    2012-09-01

    Organic UV filters including benzophenone-3 (BP-3) are widely used to protect humans and materials from damage by UV irradiation. Despite the environmental occurrence of BP-3 in the aquatic environment, little is known about its effects and modes of action. In the present study we assess molecular and physiological effects of BP-3 in adult male zebrafish (Danio rerio) and in eleuthero-embryos by a targeted gene expression approach focusing on the sex hormone system. Fish and embryos are exposed for 14 days and 120 hours post fertilization, respectively, to 2.4–312 μg/L and 8.2–438 μg/L BP-3. Chemical analysis of water and fish demonstrates that BP-3 is partly transformed to benzophenone-1 (BP-1) and both compounds are accumulated in adult fish. Biotransformation to BP-1 is absent in eleuthero-embryos. BP-3 exposure leads to similar alterations of gene expression in both adult fish and eleuthero-embryos. In the brain of adult males esr1, ar and cyp19b are down-regulated at 84 μg/L BP-3. There is no induction of vitellogenin expression by BP-3, both at the transcriptional and protein level. An overall down-regulation of the hsd3b, hsd17b3, hsd11b2 and cyp11b2 transcripts is observed in the testes, suggesting an antiandrogenic activity. No histological changes were observed in the testes after BP-3 treatment. The study leads to the conclusion that low concentrations of BP-3 exhibit similar multiple hormonal activities at the transcription level in two different life stages of zebrafish. Forthcoming studies should show whether this translates to additional physiological effects. Highlights: ► Activity of UV filter benzophenone-3 (BP-3) is assessed in zebrafish. ► BP-3 is partly metabolized to benzophenone-1 by adult fish but not embryos. ► Alterations of gene expression are similar in adult males and embryos. ► Gene expression alterations point to multiple hormonal activity of BP-3.

  18. Identification of a Typical CSTR Using Optimal Focused Time Lagged Recurrent Neural Network Model with Gamma Memory Filter

    Directory of Open Access Journals (Sweden)

    S. N. Naikwad

    2009-01-01

    Full Text Available A focused time lagged recurrent neural network (FTLR NN with gamma memory filter is designed to learn the subtle complex dynamics of a typical CSTR process. Continuous stirred tank reactor exhibits complex nonlinear operations where reaction is exothermic. It is noticed from literature review that process control of CSTR using neuro-fuzzy systems was attempted by many, but optimal neural network model for identification of CSTR process is not yet available. As CSTR process includes temporal relationship in the input-output mappings, time lagged recurrent neural network is particularly used for identification purpose. The standard back propagation algorithm with momentum term has been proposed in this model. The various parameters like number of processing elements, number of hidden layers, training and testing percentage, learning rule and transfer function in hidden and output layer are investigated on the basis of performance measures like MSE, NMSE, and correlation coefficient on testing data set. Finally effects of different norms are tested along with variation in gamma memory filter. It is demonstrated that dynamic NN model has a remarkable system identification capability for the problems considered in this paper. Thus FTLR NN with gamma memory filter can be used to learn underlying highly nonlinear dynamics of the system, which is a major contribution of this paper.

  19. Environmental occurrence and ecological risk assessment of organic UV filters in marine organisms from Hong Kong coastal waters.

    Science.gov (United States)

    Sang, Ziye; Leung, Kelvin Sze-Yin

    2016-10-01

    Organic UV filters, now considered to be emerging contaminants in aquatic ecosystems, are being intensively tracked in environmental waters worldwide. However, their environmental fate and impact of these contaminants on marine organisms remains largely unknown, especially in Asia. This work elucidates the occurrence and the ecological risks of seven UV filters detected in farmed fish, wild mussels and some other wild organisms collected from local mariculture farms in Hong Kong. For all of the organisms, ethylhexyl methoxycinnamate (EHMC) and octyl dimethyl p-aminobenzoic acid (OD-PABA) were the predominant contaminants with the highest concentrations up to 51.3 and 24.1ng/g (dw), respectively; lower levels were found for benzophenone-8 (BP-8), octocrylene (OC) and benzophenone-3 (BP-3) from UV filters indicated a positive correlation between their measured concentrations and the anthropogenic activities responsible for their direct emission. The ecological risk assessment specific to the marine aquatic environment was carried out. The risk quotient (RQ) values of EHMC and BP-3 were calculated as 3.29 and 2.60, respectively, indicating these two UV filters may pose significant risks to the marine aquatic environment. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Development of a HPLC method for determination of four UV filters in sunscreen and its application to skin penetration studies.

    Science.gov (United States)

    Souza, Carla; Maia Campos, Patrícia M B G

    2017-12-01

    This study describes the development, validation and application of a high-performance liquid chromatography (HPLC) method for the simultaneous determination of the in vitro skin penetration profile of four UV filters on porcine skin. Experiments were carried out on a gel-cream formulation containing the following UV filters: diethylamino hydroxybenzoyl hexyl benzoate (DHHB), bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT), methylene bis-benzotriazolyl tetramethylbutylphenol (MBBT) and ethylhexyl triazone (EHT). The HPLC method demonstrated suitable selectivity, linearity (10.0-50.0 μg/mL), precision, accuracy and recovery from porcine skin and sunscreen formulation. The in vitro skin penetration profile was evaluated using Franz vertical diffusion cells for 24 h after application on porcine ear skin. None of the UV filters penetrated the porcine skin. Most of them stayed on the skin surface (>90%) and only BEMT, EHT and DHHB reached the dermis plus epidermis layer. These results are in agreement with previous results in the literature. Therefore, the analytical method was useful to evaluate the in vitro skin penetration of the UV filters and may help the development of safer and effective sunscreen products. Copyright © 2017 John Wiley & Sons, Ltd.

  1. Applicability of light sources and the inner filter effect in UV/acetylacetone and UV/H{sub 2}O{sub 2} processes

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Bingdang; Yang, Minghui [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023 (China); Yin, Ran [Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); Zhang, Shujuan, E-mail: sjzhang@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023 (China)

    2017-08-05

    Highlights: • Acetylacetone (AA) could directly use solar irradiation to decolorize dyes. • AA had a wider applicability than H{sub 2}O{sub 2} to a variety of light sources. • The photonic efficiency in the UV/AA process was target-dependent. • An accurate calculation approach for the inner filter effect was developed. - Abstract: Light source is a crucial factor in the application of a photochemical process, which determines the energy efficiency. The performances of acetylacetone (AA) in conversion of aqueous contaminants under irradiation with a low-pressure mercury lamp, a medium-pressure mercury lamp, a xenon lamp, and natural sunlight were investigated and compared with those of H{sub 2}O{sub 2} as reference. In all cases, AA was superior to H{sub 2}O{sub 2} in the degradation of Acid Orange 7. Using combinations of the different light sources with various cut-off and band-pass filters, the spectra responses of the absorbed photons in the UV/AA and UV/H{sub 2}O{sub 2} processes were determined for two colored and two colorless compounds. The photonic efficiency (φ) of the two photochemical processes was found to be target-dependent. A calculation approach for the inner filter effect was developed by taking the obtained φ into account, which provides a more accurate indication of the reaction mechanisms.

  2. Transformation of benzophenone-type UV filters by chlorine: Kinetics, products identification and toxicity assessments

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jian; Ma, Li-yun; Xu, Li, E-mail: xulpharm@mails.tjmu.edu.cn

    2016-07-05

    Highlights: • Chlorination kinetics of three benzophenone-type UV filters (BPs) was studied. • Chlorination of BPs followed second-order reaction. • The transformation products (TPs) of six BPs were identified. • Several transformation pathways were proposed. • Mostly enhanced toxicity of TPs after chlorination was observed. - Abstract: The present study focused on the kinetics, transformation pathways and toxicity of several benzophenone-type ultraviolet filters (BPs) during the water chlorination disinfection process. The transformation kinetics of the studied three BPs was found to be second-order reaction, which was dependent on the concentration of BPs and chlorine. The second-order rate constants increased from 86.7 to 975 M{sup −1} s{sup −1} for oxybenzone, 49.6–261.7 M{sup −1} s{sup −1} for 4-hydroxybenzophenone and 51.7–540 M{sup −1} s{sup −1} for 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid with the increasing pH value from 6 to 8 of the chlorination disinfection condition. Then the transformation products (TPs) of these BPs were identified by HPLC-QTof analysis. Several transformation pathways, including electrophilic substitution, methoxyl substitution, ketone groups oxidation, hydrolysis, decarboxylation and ring cleavage reaction, were speculated to participate in the chlorination transformation process. Finally, according to the toxicity experiment on luminescent bacteria, Photobacterium phosphoreum, enhanced toxicity was observed for almost all the TPs of the studied BPs except for 2,2′-dihydroxy-4,4′-dimethoxybenzophenone; it suggested the formation of TPs with more toxic than the parent compounds during the chlorination process. The present study provided a foundation to understand the transformation of BPs during chlorination disinfection process, and was of great significance to the drinking water safety.

  3. Single and joint ecotoxicity data estimation of organic UV filters and nanomaterials toward selected aquatic organisms. Urban groundwater risk assessment.

    Science.gov (United States)

    Molins-Delgado, Daniel; Gago-Ferrero, Pablo; Díaz-Cruz, M Silvia; Barceló, Damià

    2016-02-01

    The hazardous potential of organic UV filters (UV-Fs) is becoming an issue of great concern due to the widespread application of these compounds in most daily-use goods, such as hygiene and beauty products. Nanomaterials (NMs) have also been used in personal care products (PCPs) for many years. Nowadays, both classes of chemicals are considered environmental emerging contaminants. Despite some studies performed in vitro and in vivo reported adverse effects of many UV-Fs on the normal development of organisms, there is scarce data regarding acute and chronic toxicity. The aim of the present study was to determine the EC50 values of selected UV-Fs using standardised toxicity assays on three aquatic species i.e. Daphnia magna, Raphidocelis subcapitata and Vibrio fischeri. EC50 values obtained were in the mgl(-1) range for all the species. The estimated toxicity data allowed us to assess the environmental risk posed by selected UV-Fs in urban groundwater from Barcelona (Spain). The calculated ecological risk indicated a negligible impact on the aquifer. Giving the increasing importance of studying mixtures of pollutants and due to the widespread presence of nanomaterials (NMs) in the aquatic environment, other objective of this work was to explore the response on D. magna after exposure to both binary combinations of UV-Fs among them and UV-F with NMs. In all cases but the nano-silver mixtures, joint toxicity was mitigated or even eradicated. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Occurrence of pharmaceuticals and UV-filters in riverine run-offs and waters of the German Baltic Sea.

    Science.gov (United States)

    Fisch, Kathrin; Waniek, Joanna J; Schulz-Bull, Detlef E

    2017-11-15

    The occurrence of pharmaceuticals and personal care products (PPCPs) in the marine environment is of great concern. This study was done to determine the emergence of eight pharmaceuticals and eleven ultraviolet filters (UV-Filters) in 5 rivers/streams discharging into the Baltic Sea. Furthermore, a focus was put on the influence of wastewater treatment plant as indirect source and the occurrence of the PPCPs in close beach proximity. Two pharmaceuticals (sulfamethoxazole, salicylic acid) and two UV-filters (2-phenylbenzimidazole-5-sulfonic acid, octocrylene) were detected in all analyzed water samples, with concentration ranging from 0.6ng/L to 836.3ng/L. In all rivers the PPCP concentration decreases towards the Baltic Sea. Sulfamethoxazole was detected at comparable concentration along the coast, which leads to the assumption of stable concentration in beach proximity. Along the coast UV-filters appeared in varying concentrations, leading to the conclusion that the direct input into the marine environment plays a bigger role than the indirect input. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. The occurrence of UV filters in natural and drinking water in São Paulo State (Brazil).

    Science.gov (United States)

    da Silva, Claudia Pereira; Emídio, Elissandro Soares; de Marchi, Mary Rosa Rodrigues

    2015-12-01

    Ultraviolet (UV) filters are widely used in the formulation of personal care products (PCPs) to prevent damage to the skin, lips, and hair caused by excessive UV radiation. Therefore, large amounts of these substances are released daily into the aquatic environment through either recreational activities or the release of domestic sewage. The concern regarding the presence of such substances in the environment and the exposure of aquatic organisms is based on their potential for bioaccumulation and their potential as endocrine disruptors. Although there are several reports regarding the occurrence and fate of UV filters in the aquatic environment, these compounds are still overlooked in tropical areas. In this study, we investigated the occurrence of the organic UV filters benzophenone-3 (BP-3), ethylhexyl salicylate (ES), ethylhexyl methoxycinnamate (EHMC), and octocrylene (OC) in six water treatment plants in various cities in Southeast Brazil over a period of 6 months to 1 year. All of the UV filters studied were detected at some time during the sampling period; however, only EHMC and BP-3 were found in quantifiable concentrations, ranging from 55 to 101 and 18 to 115 ng L(-1), respectively. Seasonal variation of BP-3 was most clearly noticed in the water treatment plant in Araraquara, São Paulo, where sampling was performed for 12 months. BP-3 was not quantifiable in winter but was quantifiable in summer. The levels of BP-3 were in the same range in raw, treated and chlorinated water, indicating that the compound was not removed by the water treatment process.

  6. Can coastline plant species be used as biosamplers of emerging contaminants? - UV-filters and synthetic musks as case studies.

    Science.gov (United States)

    Ribeiro, H; Ramos, S; Homem, V; Santos, L

    2017-10-01

    Personal care products, an important class of emerging contaminants, have been frequently detected in different environmental matrices. Included in this category are synthetic musks compounds (SMCs) and UV-filters. Their occurrence in the coastal environment has been poorly studied. Therefore, this work aimed to verify whether five coastline plant species (Carpobrotus edulis, Cakile maritima, Medicago marina, Elymus farctus borealis-atlanticus and Euphorbia paralias) have the ability to accumulate 11 SMCs (cashmeran, celestolide, phantolide, galaxolide, tonalide, exaltolide, musk moskene, tibetene, ambrette, xylene and ketone) and 2 organic UVB filters (3-(4'-methylbenzylidene) camphor and octocrylene), functioning as biosamplers. To accomplish this task, a QuEChERS technique ("Quick, Easy, Cheap, Effective, Rugged, and Safe") was employed to extract the target compounds from the plant material collected in 15 beaches of Matosinhos and Vila Nova de Gaia (Portugal). The resulting extracts were analysed by gas chromatography-mass spectrometry. Limits of detection ranged from 0.02 ng g -1 for celestolide and tonalide to 1.32 ng g -1 for musk ambrette. The obtained recoveries were around 93% and relative standard deviation was generally less than 15%. SMCs were detected at levels ranging from 1.56 to 350 ng g -1 dw and UV-filters from 2.9 to 264 ng g -1 dw. Galaxolide and 3-(4'-methylbenzylidene) camphor were the synthetic musk and UV-filter detected in higher concentrations, respectively. Plants with higher water content accumulate better SMCs (hottentot-fig), while those with higher lipid content retain better the UV-filters (sea spurge). Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Novel benzophenone-3 derivatives with promising potential as UV filters: Relationship between structure, photoprotective potential and phototoxicity.

    Science.gov (United States)

    González, María Teresa Páez; Fumagalli, Fernando; Benevenuto, Carolina Gomes; da Silva Emery, Flavio; Gaspar, Lorena Rigo

    2017-04-01

    Benzophenone-3 (BP-3) is a UV filter with absorption at the UVB and UVA wavelengths which has not been extensively studied in experiments involving its absorbing effects and toxicity. We synthetized four BP-3 derivatives and characterized their photoprotective potential by UV absorption and photodegradation, their phototoxicity potential by 3T3 Neutral Red Uptake (3T3 NRU PT) and their photoreactivity by the reactive oxygen species (ROS) assay. The UV absorption, photodegradation, phototoxicity and photoreactivity of the four BP-3 derivatives (BP-3 carbonate, BP-3 carbazole, BP-3 phenylamine and BP-3 methoxy-phenylamine) were evaluated and compared to those of BP-3. Results showed that all derivatives were photostable, except BP-3 carbonate, which did not absorb in the UVA range. BP-3 phenylamine and BP-3 methoxy-phenylamine were considered non-phototoxic and weakly photoreactive in the ROS assay, while the carbazole derivative was considered phototoxic and non-photoreactive due to its rigid structure. The UV spectra of BP-3 carbonate, BP-3 phenylamine and BP-3 methoxy-phenylamine showed the influence of hydrogen bonding on their UV absorption. Based on these results, we concluded that BP-3 phenylamine and BP-3 methoxy-phenylamine could be promising UVA filters. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. The fate of pharmaceuticals, steroid hormones, phytoestrogens, UV-filters and pesticides during MBR treatment.

    Science.gov (United States)

    Wijekoon, Kaushalya C; Hai, Faisal I; Kang, Jinguo; Price, William E; Guo, Wenshan; Ngo, Hao H; Nghiem, Long D

    2013-09-01

    This study examined the relationship between molecular properties and the fate of trace organic contaminants (TrOCs) in the aqueous and solid phases during wastewater treatment by MBR. A set of 29 TrOCs was selected to represent pharmaceuticals, steroid hormones, phytoestrogens, UV-filters and pesticides that occur ubiquitously in municipal wastewater. Both adsorption and biodegradation/transformation were found responsible for the removal of TrOCs by MBR treatment. A connection between biodegradation and molecular structure could be observed while adsorption was the dominant removal mechanism for the hydrophobic (logD>3.2) compounds. Highly hydrophobic (logD>3.2) but readily biodegradable compounds did not accumulate in sludge. In contrast, recalcitrant compounds with a moderate hydrophobicity, such as carbamazepine, accumulated significantly in the solid phase. The results provide a framework to predict the removal and fate of TrOCs by MBR treatment. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  9. UV-filters and musk fragrances in seafood commercialized in Europe Union: Occurrence, risk and exposure assessment

    DEFF Research Database (Denmark)

    Cunha, S. C.; Trabalón, L.; Jacobs, S.

    2018-01-01

    In the framework of the FP7 ECsafeSeafood project, 62 seafood samples commercialized in Europe Union from several representative species – mackerel, tuna, salmon, seabream, cod, monkfish, crab, shrimp, octopus, perch and plaice – were analysed for residues of 21 personal care products (PCPs......), including 11 UV-filters (UV-Fs) and 10 musk fragrances (musks). PCPs analysis were performed by Quick, Easy, Cheap, Effective Rugged, Safe (QuEChERS), combined with liquid-liquid extraction (LLE) or dispersive solid-phase extraction (dSPE), followed by gas chromatography-tandem mass spectrometry (GC...

  10. Trans-resveratrol and beta-carotene from sunscreens penetrate viable skin layers and reduce cutaneous penetration of UV-filters.

    Science.gov (United States)

    Freitas, J V; Praça, F S G; Bentley, M V L B; Gaspar, L R

    2015-04-30

    Cutaneous permeation is a critical parameter when topical application of sunscreens containing antioxidants is considered. The aim of this study was to evaluate the cutaneous penetration of most marketed UV-filters combined with trans-resveratrol (RES) and beta-carotene (BTC) since few studies report skin penetration when such compounds are applied. Formulations containing octocrylene, octyl methoxycinnamate, avobenzone and bemotrizinole were prepared and supplemented or not with BTC, or with RES, or with both compounds in combination. Penetration studies were performed using Franz vertical diffusion cells and porcine ear skin as the biological membrane. The quantification of UV-filters and antioxidants in the stratum corneum (SC), viable epidermis plus dermis and receptor fluid was performed by HPLC. Results suggested that UV-filters and antioxidants did not permeate the skin but were retained for 12h post application. About 90% and 80%, respectively, of the total penetrated amount of UV-filters and antioxidants was found in the SC. Interestingly, it was observed that BTC, alone or combined with RES, reduced the skin retention of UV-filters on average by 63%. In conclusion, this study demonstrated that the combination of antioxidants and UV-filters in sunscreens is advantageous for cutaneous penetration, since BTC and BTC+RES improved sunscreen safety by reducing delivery of the four UV-filters in the study into SC and viable epidermis. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Presence of benzophenones commonly used as UV filters and absorbers in paired maternal and fetal samples.

    Science.gov (United States)

    Krause, M; Frederiksen, H; Sundberg, K; Jørgensen, F S; Jensen, L N; Nørgaard, P; Jørgensen, C; Ertberg, P; Juul, A; Drzewiecki, K T; Skakkebaek, N E; Andersson, A M

    2018-01-01

    Previous studies have demonstrated widespread exposure of humans to certain benzophenones commonly used as UV filters or UV absorbers; some of which have been demonstrated to have endocrine disrupting abilities. To examine whether benzophenones present in pregnant women pass through the placental barrier to amniotic fluid and further to the fetal blood circulation. A prospective study of 200 pregnant women with simultaneously collected paired samples of amniotic fluid and maternal serum and urine. In addition, unique samples of human fetal blood (n=4) obtained during cordocentesis: and cord blood (n=23) obtained at delivery, both with paired maternal samples of serum and urine collected simultaneously, were used. All biological samples were analyzed by TurboFlow-liquid chromatography - tandem mass spectrometry for seven different benzophenones. Benzophenone-1 (BP-1), benzophenone-3 (BP-3), 4-methyl-benzophenone (4-MBP), and 4-hydroxy-benzophenone (4-HBP) were all detectable in amniotic fluid and cord blood samples and except 4-HBP also in fetal blood; albeit at a low frequency. BP-1 and BP-3 were measured at ~10-times lower concentrations in fetal and cord blood compared to maternal serum and 1000-times lower concentration compared to maternal urine levels. Therefore BP-1 and BP-3 were only detectable in the fetal circulation in cases of high maternal exposure indicating some protection by the placental barrier. 4-MBP seems to pass into fetal and cord blood more freely with a median 1:3 ratio between cord blood and maternal serum levels. Only for BP-3, which the women seemed to be most exposed to, did the measured concentrations in maternal urine and serum correlate to concentrations measured in amniotic fluid. Thus, for BP-3, but not for the other tested benzophenones, maternal urinary levels seem to be a valid proxy for fetal exposure. Detectable levels of several of the investigated benzophenones in human amniotic fluid as well as in fetal and cord blood calls

  12. Simultaneous separation and determination of 15 organic UV filters in sunscreen cosmetics by HPLC-ESI-MS/MS.

    Science.gov (United States)

    Meng, X; Ma, Q; Bai, H; Wang, Z; Han, C; Wang, C

    2017-08-01

    A comprehensive methodology for the simultaneous determination of 15 multiclass organic UV filters in sunscreen cosmetics was developed using high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Sunscreen cosmetics of various matrices, such as toning lotion, emulsion, cream and lipstick, were analysed. Ultrasound-assisted extraction (UAE) was utilized as the extraction technique for sample preparation. The 15 UV filters were chromatographically separated by two groups of mobile phase system on an XBridge C 18 analytical column (150 × 2.1 mm I.D., 3.5 μm particle size) and quantified using HPLC-ESI-MS/MS. The quantitation was performed using the external calibration method. The established method was validated in terms of linearity, sensitivity, specificity, accuracy, stability, intraday and interday precisions, recovery and matrix effect. The method was also applied for the determination of UV filters in commercial sunscreen cosmetics. The experimental results demonstrated that the developed method was accurate, rapid and sensitive and can be used for the analytical control of sunscreen cosmetics. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  13. In vivo photoprotective effects of cosmetic formulations containing UV filters, vitamins, Ginkgo biloba and red algae extracts.

    Science.gov (United States)

    Mercurio, D G; Wagemaker, T A L; Alves, V M; Benevenuto, C G; Gaspar, L R; Maia Campos, P M B G

    2015-12-01

    The aim of this study was to assess the photoprotective effects of cosmetic formulations containing UV filters, red algae, Porphyra umbilicalis, extracts and combinations of the extract with vitamins and Ginkgo biloba through the use of in vivo preclinical studies. For this study, 4 groups of 4 hairless mice each were treated with topical formulations applied on the dorsum for 5 days as follows: group 1 - control (no treatment); group 2 - application of the formulation F (sunscreen formulation containing only UV filters); group 3 - application of the formulation FA (sunscreen formulation with red algae extract); and group 4 - application of the formulation FVGA (sunscreen formulation with red algae extract, G. biloba and vitamins A, C and E). The effects of these formulations were evaluated by determining the transepidermal water loss (TEWL) and erythema index. Apoptosis was detected by immunohistochemical staining with anti-p53 and anti-caspase-3 antibodies. The results showed that the formulations protected the skin from erythema when exposed to UV radiation. The group that received the formulation FVGA presented a greater TEWL than did the other groups, suggesting that this formulation was involved in cell renewal. Immunohistochemical analysis showed that UV radiation caused an increase in the expression of p53 and active caspase-3, confirming that the damage caused by UV radiation exposure led to apoptosis. The application of all formulations studied resulted in a statistically significant reduction in the expression of p53 and caspase-3, with a more pronounced effect observed following treatment with FA. In conclusion, extracts from the red algae P. umbilicalis could be considered effective ingredients to be used in sunscreen formulations. The combination of vitamins A, E, C and G. biloba along with red algae extracts can improve significantly the performance of the sunscreens, preventing UV-induced DNA damage and inflammation. Thus, they should be considered

  14. Enabling HST UV Exploration of the Low Surface Brightness Universe: A Pilot Study with the WFC3 X Filter Set

    Science.gov (United States)

    Thilker, David

    2017-08-01

    We request 17 orbits to conduct a pilot study to examine the effectiveness of the WFC3/UVIS F300X filter for studying fundamental problems in star formation in the low density regime. In principle, the broader bandpass and higher throughput of F300X can halve the required observing time relative to F275W, the filter of choice for studying young stellar populations in nearby galaxies. Together with F475W and F600LP, this X filter set may be as effective as standard UVIS broadband filters for characterizing the physical properties of such populations. We will observe 5 low surface brightness targets with a range of properties to test potential issues with F300X: the red tail to 4000A and a red leak beyond, ghosts, and the wider bandpass. Masses and ages of massive stars, young star clusters, and clumps derived from photometry from the X filter set will be compared with corresponding measurements from standard filters. Beyond testing, our program will provide the first sample spanning a range of LSB galaxy properties for which HST UV imaging will be obtained, and a glimpse into the ensemble properties of the quanta of star formation in these strange environments. The increased observing efficiency would make more tractable programs which require several tens to hundreds of orbits to aggregate sufficient numbers of massive stars, young star clusters, and clumps to build statistical samples. We are hopeful that our pilot observations will broadly enable high-resolution UV imaging exploration of the low density frontier of star formation while HST is still in good health.

  15. Applicability of light sources and the inner filter effect in UV/acetylacetone and UV/H2O2processes.

    Science.gov (United States)

    Wu, Bingdang; Yang, Minghui; Yin, Ran; Zhang, Shujuan

    2017-08-05

    Light source is a crucial factor in the application of a photochemical process, which determines the energy efficiency. The performances of acetylacetone (AA) in conversion of aqueous contaminants under irradiation with a low-pressure mercury lamp, a medium-pressure mercury lamp, a xenon lamp, and natural sunlight were investigated and compared with those of H 2 O 2 as reference. In all cases, AA was superior to H 2 O 2 in the degradation of Acid Orange 7. Using combinations of the different light sources with various cut-off and band-pass filters, the spectra responses of the absorbed photons in the UV/AA and UV/H 2 O 2 processes were determined for two colored and two colorless compounds. The photonic efficiency (φ) of the two photochemical processes was found to be target-dependent. A calculation approach for the inner filter effect was developed by taking the obtained φ into account, which provides a more accurate indication of the reaction mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Penetration of UV-B radiation in foliage: evidence that the epidermis behaves as a non-uniform filter

    International Nuclear Information System (INIS)

    Day, T.A.; Martin, G.; Vogelmann, T.C.

    1993-01-01

    epidermis of P. pungens with either the fluorescing film or the fibre-optic microprobe technique. The epidermis appears to be a much more spatially uniform UV-B filter in conifers than in these herbaceous species

  17. Multiresidue determination of UV filters in water samples by solid-phase extraction and liquid chromatography with tandem mass spectrometry analysis.

    Science.gov (United States)

    Capriotti, Anna Laura; Cavaliere, Chiara; Piovesana, Susy; Samperi, Roberto; Stampachiacchiere, Serena; Ventura, Salvatore; Laganà, Aldo

    2014-10-01

    UV filters, contained in sunscreens and other cosmetic products, as well as in some plastics and industrial products, are nowadays considered contaminants of emerging concern because their widespread and increasing use has lead to their presence in the environment. Furthermore, some UV filters are suspected to have endocrine disruption activity. In the present work, we developed an analytical method based on liquid chromatography with tandem mass spectrometry for the determination of UV filters in tap and lake waters. Sixteen UV filters were extracted from water samples by solid-phase extraction employing graphitized carbon black as adsorbent material. Handling 200 mL of water sample, satisfactory recoveries were obtained for almost all the analytes. The limits of detection and quantification of the method were comparable to those reported in other works, and ranged between 0.7-3.5 and 1.9-11.8 ng/L, respectively; however in our case the number of investigated compounds was larger. The major encountered problem in method development was to identify the background contamination sources and reduce their contribution. UV filters were not detected in tap water samples, whereas the analyses conducted on samples collected from three different lakes showed that the swimming areas are most subject to UV filter contamination. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Additive estrogenic effects of mixtures of frequently used UV filters on pS2-gene transcription in MCF-7 cells

    International Nuclear Information System (INIS)

    Heneweer, Marjoke; Muusse, Martine; Berg, Martin van den; Sanderson, J. Thomas

    2005-01-01

    In order to protect consumers from ultraviolet (UV) radiation and enhance light stability of the product, three to eight UV filters are usually added to consumer sunscreen products. High lipophilicity of the UV filters has been shown to cause bioaccumulation in fish and humans, leading to environmental levels of UV filters that are similar to those of PCBs and DDT. In this paper, estrogen-regulated pS2 gene transcription in the human mammary tumor cell line MCF-7 was used as a measure of estrogenicity of four individual UV filters. Since humans are exposed to more than one UV filter at a time, an equipotent binary mixture of 2-hydroxy-4-methoxy-benzophenone (BP-3) and its metabolite 2,4-dihydroxy benzophenone (BP-1), as well as an equipotent multi-component mixture of BP-1, BP-3, octyl methoxy cinnamate (OMC) and 3-(4-methylbenzylidene) camphor (4-MBC), were also evaluated for their ability to induce pS2 gene transcription in order to examine additivity. An estrogen receptor-mediated mechanism of action was expected for all UV filters. Therefore, our null-hypothesis was that combined estrogenic responses, measured as increased pS2 gene transcription in MCF-7 cells after exposure to mixtures of UV filters, are additive, according to a concentration-addition model. Not all UV filters produced a full concentration-response curve within the concentration range tested (100 nM-1 μM). Therefore, instead of using EC 50 values for comparison, the concentration at which each compound caused a 50% increase of basal pS2 gene transcription was defined as the C50 value for that compound and used to calculate relative potencies. For comparison, the EC 50 value of a compound is the concentration at which the compound elicits an effect that is 50% of its maximal effect. Individual UV filters increased pS2 gene transcription concentration-dependently with C50 values of 0.12 μM, 0.5 μM, 1.9 μM, and 1.0 μM for BP-1, BP-3, 4-MBC and OMC, respectively. Estradiol (E2) had a C50

  19. Field research on the effects of UV-B filters on terrestrial Antarctic vegetation

    NARCIS (Netherlands)

    Huiskes, A.H.L.; Lud, D.; Moerdijk-Poortvliet, T.C.W.

    2001-01-01

    Patches of vegetation of six common species growing on Leonie Island (67 degrees 35' S, 68 degrees 20' W), Antarctic Peninsula region were covered with either UV-B transparent perspex screens or UV-B absorbing screens. Uncovered plots served as a control. Temperature and relative humidity were

  20. Prevention of UVA-induced oxidative damage in human dermal fibroblasts by new UV filters, assessed using a novel in vitro experimental system.

    Directory of Open Access Journals (Sweden)

    Francesca Brugè

    Full Text Available BACKGROUND: UVA rays present in sunlight are able to reach the dermal skin layer generating reactive oxygen species (ROS responsible for oxidative damage, alterations in gene expression, DNA damage, leading to cell inflammation, photo-ageing/-carcinogenesis. Sunscreens contain UV filters as active ingredients that absorb/reflect/dissipate UV radiation: their efficiency depends on their spectral profile and photostability which should then be reflected in biological protection of underlying skin. METHODS: A set of new UV filters was synthesized, and the most photostable one was compared to BMDBM, a widely used UVA filter. Cultured human dermal fibroblasts were exposed to UVA radiation which was filtered by a base cream containing or not UV filters placed above cell culture wells. The endpoints measured were: cell viability (MTT assay, ROS generation (DCFH-DA assay, mitochondrial function (JC-1 assay, DNA integrity (Comet assay and gene expression (MMP-1, COL1A1 by RT-qPCR. RESULTS: The new UV filter resulted more efficient than BMDBM in preserving cell viability, mitochondrial functionality and oxidative DNA damage, despite similar inhibition levels of intracellular ROS. Moreover, expression of genes involved in dermal photoageing were positively affected by the filtering action of the tested molecules. CONCLUSIONS: The experimental model proposed was able to validate the efficacy of the new UV filter, taking into account important cellular events related to UV-induced intracellular oxidative stress, often underestimated in the assessments of these compounds. GENERAL SIGNIFICANCE: The model may be used to compare the actual biological protection of commercial sunscreens and suncare products aside from their SPF and UVA-PF values.

  1. Prevention of UVA-induced oxidative damage in human dermal fibroblasts by new UV filters, assessed using a novel in vitro experimental system.

    Science.gov (United States)

    Brugè, Francesca; Tiano, Luca; Astolfi, Paola; Emanuelli, Monica; Damiani, Elisabetta

    2014-01-01

    UVA rays present in sunlight are able to reach the dermal skin layer generating reactive oxygen species (ROS) responsible for oxidative damage, alterations in gene expression, DNA damage, leading to cell inflammation, photo-ageing/-carcinogenesis. Sunscreens contain UV filters as active ingredients that absorb/reflect/dissipate UV radiation: their efficiency depends on their spectral profile and photostability which should then be reflected in biological protection of underlying skin. A set of new UV filters was synthesized, and the most photostable one was compared to BMDBM, a widely used UVA filter. Cultured human dermal fibroblasts were exposed to UVA radiation which was filtered by a base cream containing or not UV filters placed above cell culture wells. The endpoints measured were: cell viability (MTT assay), ROS generation (DCFH-DA assay), mitochondrial function (JC-1 assay), DNA integrity (Comet assay) and gene expression (MMP-1, COL1A1) by RT-qPCR. The new UV filter resulted more efficient than BMDBM in preserving cell viability, mitochondrial functionality and oxidative DNA damage, despite similar inhibition levels of intracellular ROS. Moreover, expression of genes involved in dermal photoageing were positively affected by the filtering action of the tested molecules. The experimental model proposed was able to validate the efficacy of the new UV filter, taking into account important cellular events related to UV-induced intracellular oxidative stress, often underestimated in the assessments of these compounds. The model may be used to compare the actual biological protection of commercial sunscreens and suncare products aside from their SPF and UVA-PF values.

  2. Correction and Validation of Total Ozone Data Series From An Antarctic Multichannel Filter Radiometer Solar UV Network

    Science.gov (United States)

    Torres, C.; Redondas, A.; Cuevas, E.; Lakkala, K.; Taalas, P.

    The Antarctic Network of the MAR-Project (Measurement of Antarctic Radiance for monitoring the ozone layer) is the result of a co-operation among the Instituto Nacional de Meteorología (INM, Spain), Instituto Nacional de Técnica Aeroespacial (INTA, Spain), the Instituto Antártico Argentino - Dirección Nacional del Antártico (IAA/DNA), the Finnish Meteorological Institute (FMI), and the Centro Austral de Investigaciones Científicas (CADIC, Argentina). This network consists on three NILU-UV6 multichannel filter radiometers installed at the Argentinean Antarctic bases of Vicecomodoro Marambio and Belgrano II, and at the CADIC in Ushuaia, respectively. These instruments measure at five UV channels (305, 3120, 320, 340 and 380 nm) and PAR (400 - 700 nm). Quality control and quality assurance systems of the network give us information for irradiance correction. Quality control is based on the 2-week lamp tests performed at each station, and provides quantitative information about the stability of each instrument. Quality assurance, which is performed twice a year by the FMI, lies in inter-comparisons between the travelling reference instrument and the station instruments. These intercomparisons provide calibration coefficients for each channel. Ozone can be derived from the NILU-UV6 instruments using the 305 nm / 320 nm ratio. Ozone data series before and after irradiance correction are compared against independent ozone measurements from the TOMS, the Dobson and the UV-VIS instruments at the Ushuaia station.

  3. Emission of poly and perfluoroalkyl substances, UV-filters and siloxanes to air from wastewater treatment plants.

    Science.gov (United States)

    Shoeib, Mahiba; Schuster, Jasmin; Rauert, Cassandra; Su, Ky; Smyth, Shirley-Anne; Harner, Tom

    2016-11-01

    The potential of wastewater treatment plants (WWTPs) to act as sources of poly and perfluoroalkyl substances (PFASs), volatile methyl siloxanes (VMSs) and organic UV-filters to the atmosphere was investigated. Target compounds included: PFASs (fluorotelomer alcohols (FTOHs), perfluorooctane sulfonamides/sulfonamidoethanols (FOSAs/FOSEs), perfluroalkyl sulfonic acids (PFSAs) and perfluroalkyl carboxylic acids (PFCAs)), cyclic VMSs (D3 to D6), linear VMSs (L3 to L5) and eight UV-filters. Emissions to air were assessed at eight WWTPs using paired sorbent-impregnated polyurethane foam passive air samplers, deployed during summer 2013 and winter 2014. Samplers were deployed on-site above the active tank and off-site as a reference. Several types of WWTPs were investigated: secondary activated sludge in urban areas (UR-AS), secondary extended aeration in towns (TW-EA) and facultative lagoons in rural areas (RU-LG). The concentrations of target compounds in air were ∼1.7-35 times higher on-site compared to the corresponding off-site location. Highest concentrations in air were observed at UR-AS sites while the lowest were at RU-LG. Higher air concentrations (∼2-9 times) were observed on-site during summer compared to winter, possibly reflecting enhanced volatilization due to higher wastewater temperatures or differences in influent wastewater concentrations. A significant positive correlation was obtained between concentrations in air and WWTP characteristics (influent flow rate and population in the catchment of the WWTP); whereas a weak negative correlation was obtained with hydraulic retention time. Emissions to air were estimated using a simplified dispersion model. Highest emissions to air were seen at the UR-AS locations. Emissions to air (g/year/tank) were highest for VMSs (5000-112,000) followed by UV-filters (16-2000) then ΣPFASs (10-110). Copyright © 2016. Published by Elsevier Ltd.

  4. Design, Fabrication, and Analysis of High-Performance UV Band-pass filters

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA’s strategic mission concept, ATLAST (Advanced Technology Large-Aperture Space Telescope), is a telescope merging ultraviolet (UV) astrophysics and visible...

  5. Sorption and degradation of selected organic UV filters (BM-DBM, 4-MBC, and OD-PABA) in laboratory water-sediment systems.

    Science.gov (United States)

    Li, Sheng; Lu, Guanghua; Xie, Zhengxin; Ding, Jiannan; Liu, Jianchao; Li, Yi

    2016-05-01

    Organic UV filters that have been widely used in sunscreens and other personal care products have drawn much public concern because of their widespread contamination in the environment and their potential ecological risks to ecosystems. We selected three UV filters with high frequency of detection in the environment, namely butyl methoxy dibenzoylmethane (BM-DBM), ethylhexyl dimethyl p-aminobenzoate (OD-PABA), and 4-methylbenzylidene camphor (4-MBC), to investigate the sorption and degradation behaviors of these compounds in lab-scale water-sediment systems set up with natural water and sediment samples collected from different rivers and lakes (i.e., Yangtze River, Qinhuai River, Xuanwu Lake, and Mochou Lake) in Nanjing, East China. The sorption isotherms of these UV filters were well described by the Freundlich equation (C s   = K f  × C w (n) ). The sorption of three UV filters in four sediments was all linear or close to it, with n values between 0.92 and 1.13. A moderate to strong sorption affinity was observed for these compounds, and the sorption appears to be irreversible. For the combined sorption and degradation studies, sorption was found to be a primary mechanism for the disappearance of these UV filters from the water phase, and biotransformation appears to be the predominant factor for the degradation of the target compounds in the water-sediment systems. All three UV filters were found to be slightly resistant to the microbes in these systems, with DT50total and DT90total values-the disappearance time (DT) describes the time in which the initial total mass of the UV filters in the whole system is reduced by 50 and 90 %-ranging between 18 and 31 days and 68 and 101 days, respectively.

  6. Removal of pharmaceuticals, polybrominated flame retardants and UV-filters from sludge by the fungus Trametes versicolor in bioslurry reactor

    International Nuclear Information System (INIS)

    Rodríguez-Rodríguez, Carlos E.; Barón, Enrique; Gago-Ferrero, Pablo; Jelić, Aleksandra; Llorca, Marta; Farré, Marinella; Díaz-Cruz, M. Silvia; Eljarrat, Ethel; Petrović, Mira; Caminal, Glòria; Barceló, Damià

    2012-01-01

    Highlights: ► Sludge from a WWTP was treated in a fungal slurry reactor with Trametes versicolor. ► Twenty-four pharmaceuticals were removed at important extents. ► UV-filters and brominated flame retardants were also degraded. ► Overall toxicity of sludge increased despite the pollutant removal. - Abstract: Conventional wastewater treatments are inefficient in the removal of many organic pollutants. The presence of these contaminants in the final sludge represents a source of environmental pollution due to the increasing use of biosolids in land application. A biotechnological approach which employed the fungus Trametes versicolor in a sludge-bioslurry reactor was assessed in order to remove several groups of emerging pollutants. Biological fungal activity was monitored by means of ergosterol and laccase determinations. Fifteen out of 24 detected pharmaceuticals were removed at efficiencies over 50% after the treatment, including eight completely degraded. Removal ranged between 16–53% and 22–100% for the brominated flame retardants and the UV-filters, respectively. Only two of all the detected compounds remained unchanged after the treatment. Although elimination results are promising, the toxicity of the final sludge increased after the treatment. This finding is contrary to the toxicity results obtained in similar treatments of sludge with T. versicolor in solid-phase.

  7. Co-occurrence of musk fragrances and UV-filters in seafood and macroalgae collected in European hotspots.

    Science.gov (United States)

    Cunha, S C; Fernandes, J O; Vallecillos, L; Cano-Sancho, G; Domingo, J L; Pocurull, E; Borrull, F; Maulvault, A L; Ferrari, F; Fernandez-Tejedor, M; Van den Heuvel, F; Kotterman, M

    2015-11-01

    In the last decades, awareness regarding personal care products (PCP), i.e. synthetic organic chemicals frequently used in cosmetic and hygienic products, has become a forward-looking issue, due to their persistency in the environment and their potential multi-organ toxicity in both human and wildlife. Seafood is one of the most significant food commodities in the world and, certainly, one of the most prone to bioaccumulation of PCP, what can consequently lead to human exposure, especially for coastal population, where its consumption is more marked. The aim of this work was to evaluate the co-occurrence of musk fragrances and UV-filters in both seafood and macroalgae collected in different European hotspots (areas with high levels of pollution, highly populated and near wastewater treatment plants). Despite the fact that UV-filters were detected in three different kind of samples (mussel, mullet, and clam), in all cases they were below the limit of quantification. Galaxolide (HHCB) and tonalide (AHTN) were the musk fragrances most frequently detected and quantified in samples from the European hotspots. Cashmeran (DPMI) was also detected in most samples but only quantified in two of them (flounder/herring and mullet). The highest levels of HHCB and AHTN were found in mussels from Po estuary. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Removal of pharmaceuticals, polybrominated flame retardants and UV-filters from sludge by the fungus Trametes versicolor in bioslurry reactor

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Rodriguez, Carlos E. [Unitat Asociada de Biocatalisi Aplicada IQAC-CSIC, Escola d' Enginyeria, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Centro de Investigacion en Contaminacion Ambiental, Universidad de Costa Rica, 2060 San Jose (Costa Rica); Baron, Enrique; Gago-Ferrero, Pablo; Jelic, Aleksandra; Llorca, Marta; Farre, Marinella; Diaz-Cruz, M. Silvia; Eljarrat, Ethel [Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, 08034 Barcelona (Spain); Petrovic, Mira [Institucio Catalana de Reserca i Estudis Avancats (ICREA), Passeig Lluis Companys 23, 80010 Barcelona (Spain); Catalan Institute for Water Research (ICRA), H2O Building, Scientific and Technological Park of the University of Girona, 101-E-17003 Girona (Spain); Caminal, Gloria, E-mail: Gloria.Caminal@uab.cat [Unitat Asociada de Biocatalisi Aplicada IQAC-CSIC, Escola d' Enginyeria, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Barcelo, Damia [Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, 08034 Barcelona (Spain); Catalan Institute for Water Research (ICRA), H2O Building, Scientific and Technological Park of the University of Girona, 101-E-17003 Girona (Spain); King Saud University (KSU), P.O. Box 2455, 11451 Riyadh (Saudi Arabia); and others

    2012-09-30

    Highlights: Black-Right-Pointing-Pointer Sludge from a WWTP was treated in a fungal slurry reactor with Trametes versicolor. Black-Right-Pointing-Pointer Twenty-four pharmaceuticals were removed at important extents. Black-Right-Pointing-Pointer UV-filters and brominated flame retardants were also degraded. Black-Right-Pointing-Pointer Overall toxicity of sludge increased despite the pollutant removal. - Abstract: Conventional wastewater treatments are inefficient in the removal of many organic pollutants. The presence of these contaminants in the final sludge represents a source of environmental pollution due to the increasing use of biosolids in land application. A biotechnological approach which employed the fungus Trametes versicolor in a sludge-bioslurry reactor was assessed in order to remove several groups of emerging pollutants. Biological fungal activity was monitored by means of ergosterol and laccase determinations. Fifteen out of 24 detected pharmaceuticals were removed at efficiencies over 50% after the treatment, including eight completely degraded. Removal ranged between 16-53% and 22-100% for the brominated flame retardants and the UV-filters, respectively. Only two of all the detected compounds remained unchanged after the treatment. Although elimination results are promising, the toxicity of the final sludge increased after the treatment. This finding is contrary to the toxicity results obtained in similar treatments of sludge with T. versicolor in solid-phase.

  9. Effects of ceiling-mounted HEPA-UV air filters on airborne bacteria concentrations in an indoor therapy pool building.

    Science.gov (United States)

    Kujundzic, Elmira; Zander, David A; Hernandez, Mark; Angenent, Largus T; Henderson, David E; Miller, Shelly L

    2005-02-01

    The purpose of this study was to assess the effectiveness of a new generation of high-volume, ceiling-mounted high-efficiency particulate air (HEPA)-ultraviolet (UV) air filters (HUVAFs) for their ability to remove or inactivate bacterial aerosol. In an environmentally controlled full-scale laboratory chamber (87 m3), and an indoor therapy pool building, the mitigation ability of air filters was assessed by comparing concentrations of total bacteria, culturable bacteria, and airborne endotoxin with and without the air filters operating under otherwise similar conditions. Controlled chamber tests with pure cultures of aerosolized Mycobacterium parafortuitum cells showed that the HUVAF unit tested provided an equivalent air-exchange rate of 11 hr(-1). Using this equivalent air-exchange rate as a design basis, three HUVAFs were installed in an indoor therapy pool building for bioaerosol mitigation, and their effectiveness was studied over a 2-year period. The HUVAFs reduced concentrations of culturable bacteria by 69 and 80% during monitoring periods executed in respective years. The HUVAFs reduced concentrations of total bacteria by 12 and 76% during the same monitoring period, respectively. Airborne endotoxin concentrations were not affected by the HUVAF operation.

  10. Vapour HF release of airgap-based UV-visible optical filters

    NARCIS (Netherlands)

    Ghaderi, M.; Ayerden, N.P.; De Graaf, G.; Wolffenbuttel, R.F.

    2015-01-01

    The design and CMOS-compatible fabrication of airgap-based optical filters in a surface micromachining process with sacrificial release using thevapour phase is presented. An airgap-dielectric layer combination offers a higher refractive index contrast, as compared to the conventional

  11. Far ultraviolet filters for the ISTP UV imager. [International Solar-Terrestrial Physics mission

    Science.gov (United States)

    Zukic, Muamer; Torr, Douglas G.; Kim, Jongmin; Spann, James F.; Torr, Marsha R.

    1992-01-01

    The far ultraviolet (FUV) imager for the International Solar-Terrestrial Physics (ISTP) mission is designed to image four features of the aurora: O I lines at 130.4 nm and 135.6 nm and the N2 Lyman-Birge-Hopfield (LBH) bands between 140 nm-160 nm (LBH long) and 160 nm-180 nm (LBH long). We report the design and fabrication of narrow-band and broadband filters for the ISTP FUV imager. Narrow-band filters designed and fabricated for the O I lines have a bandwidth of less than 5 nm and a peak transmittance of 22.3 and 29.6 percent at 130.4 nm and 135.6 nm, respectively. Broadband filters designed and fabricated for LBH bands have the transmittance greater than 40 percent for LBH short and close to 60 percent for LBH long. Blocking of out-of-band wavelengths for all filters is better than 0.001 percent with the transmittance at 121.6 nm of less than 10 exp -6 percent.

  12. Determination of parabens and benzophenone-type UV filters in human placenta. First description of the existence of benzyl paraben and benzophenone-4.

    Science.gov (United States)

    Valle-Sistac, Jennifer; Molins-Delgado, Daniel; Díaz, Marta; Ibáñez, Lourdes; Barceló, Damià; Silvia Díaz-Cruz, M

    2016-03-01

    UV filters and parabens (PBs) are chemicals used in daily personal care and hygiene products to protect materials and humans from the adverse effects of UV radiation and to preserve the integrity of the formulation, respectively. Several studies highlight their widespread environmental occurrence and endocrine disrupting effects. However, little is known about human exposure to these compounds. The objective of this study was to investigate the exposure of human embryos and foetuses to endocrine disrupting UV filters and PBs. Placentas from volunteer mothers in Barcelona were collected at delivery after informed, written consent by the pregnant women. UV filters and parabens were analysed by liquid chromatography-tandem mass spectrometry. The excellent performance of the method allowed measuring the target compounds in human placental tissue at low ng/g fresh weight level. The detection frequency of the selected compounds was in the range 17-100%. Benzophenone-1, methyl paraben, butyl paraben and benzyl paraben were detected in all samples. The highest measured concentration corresponded to methyl paraben, 11.77ng/g fresh weight. Reported concentrations of benzophenone-4 and benzyl paraben constitute the first evidence about their accumulation in placenta. The results obtained corroborate that foetuses are exposed to a wide diversity of UV filters and PBs via the placenta. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Second Order Harmonics Suppression With Glass Filters for Synchrotron UV Radiation Calibration Measurement

    CERN Document Server

    Burattini, E; Gambicorti, L; Malvezzi, F; Marcelli, A; Monti, F; Pace, E

    2005-01-01

    This development is the latest result of the cooperation between the National Laboratories of Frascati and the Department of Astronomy and Space Science of the University of Florence to improve the capabilities of the existing DXR-2 beam line at the DAΦNE-LIGHT laboratories. This collaboration has assessed a new facility in order to characterize optics and sensors in a wide spectral range (ranging from VUV to IR). Previous measurements [1] have highlighted some limitations in the present setup, as higher signal levels due to the diffracted radiation of the grating in the second order have to be removed to allow an accurate detection. In this work a glass filter is used to remove such spurious signal present in the spectral region with λ > 360 nm. The characteristics of the filter and its application to the optical system used to measure the sensitivity of a diamond-based photoconductor have been discussed.

  14. Octyl-methoxycinnamate (OMC), an ultraviolet (UV) filter, alters LHRH and amino acid neurotransmitters release from hypothalamus of immature rats.

    Science.gov (United States)

    Szwarcfarb, B; Carbone, S; Reynoso, R; Bollero, G; Ponzo, O; Moguilevsky, J; Scacchi, P

    2008-02-01

    OMC (octyl-methoxycinnamate), is an endocrine disruptor with estrogenic activity, which is used in sunscreen creams as a UV filter. We studied its " IN VITRO" effects on the hypothalamic release of LHRH as well as on the amino acid neurotransmitter system in immature rats of 15 (prepubertal) and 30 (peripubertal) days of age. OMC decreased the LH-RH release significantly in male and female rats of both age. In male rats OMC increased the release of GABA while in the female ones It diminished the excitatory amino acid aspartate (ASP) and Glutamate (GLU) without modifications in the hypothalamic GABA release. These results suggest that during sexual maturation the inhibitory effect of OMC on LH-RH release appears to be related to its action on the inhibitory and excitatory amino acid neurotransmitters in male and female rats.

  15. Photolysis of the organic UV filter, avobenzone, combined with octyl methoxycinnamate by nano-TiO2 composites.

    Science.gov (United States)

    Kim, E J; Kim, M J; Im, N R; Park, S N

    2015-08-01

    A protection of the skin from harmful UV rays is important in preventing the skin damage and skin aging when exposed to sunlight. Titanium dioxide composites are used as a UV filter in sunscreen products combined with organic compounds such as butyl methoxydibenzoyl methane (avobenzone) and octyl methoxycinnamate (OMC) to improve the function of the sunscreen. In this study, the photolysis of avobenzone and OMC caused by the photocatalytic TiO2 nano composites (NCs) is investigated. Three different types of oil/water (O/W) sunscreen formulations containing avobenzone and OMC were prepared. Each formulation contained one of three different types of surface modified TiO2 NCs, which were WP-S (small sized hydrophilic TiO2NCs, ~10nm), OP-S (small sized hydrophobic TiO2NCs, ~15nm), and OP-L (large sized hydrophobic TiO2NCs, ~200nm). The physicochemical properties of the NCs were analyzed using biophysical tools. Addition of a different size of TiO2NCs into O/W sunscreen formulations significantly increased the photolysis of OMC. Effect of quercetin on degradation of avobenzone and OMC by the NCs was also studied for all three formulations. Although the OP-S NCs showed the lowest photocatalytic ability and the highest UV blocking capability, the NCs promoted the photolysis of OMC to the greatest extent. These results can be utilized to design more effective sunscreens, which could potentially ensure optimal photo-protection. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. A new method for the determination of benzophenone-UV filters in human serum samples by dispersive liquid-liquid microextraction with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Vela-Soria, F; Ballesteros, O; Zafra-Gómez, A; Ballesteros, L; Navalón, A

    2014-04-01

    Benzophenone-UV filters (BP-UV filters) are extensively used in cosmetics products to avoid damaging effects of UV radiation. Despite their low toxicity, many research papers indicate that BP-UV filters are weak endocrine disruptors (EDCs). There are clear relationships between BP-UV filters exposure and several health disorders such as carcinogenesis and malformations observed in animals. In the present work, a new sample treatment procedure by dispersive liquid-liquid microextraction (DLLME) is proposed for the extraction of six BPs, namely benzophenone-1 (BP-1), benzophenone-2 (BP-2), benzophenone-3 (BP-3), benzophenone-6 (BP-6), benzophenone-8 (BP-8) and 4-hydroxybenzophenone (4-OH-BP), in human serum samples, followed by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. The method involves an enzymatic treatment to quantify the total content (free plus conjugated species) of BP-UV filters in serum. The extraction parameters were accurately optimized using multivariate optimization approach. Benzophenone-d₁₀ (BP-d₁₀) was used as surrogate. Limits of quantification (LOQs) ranged from 0.4 to 0.9 ng mL(-1) and inter-day precision (evaluated as relative standard deviation) ranged from 1.9% to 13.1%. The method was validated using matrix-matched calibration and a recovery assay. Recovery rates for spiked samples ranged from 97% to 106%, and acceptable linearity was obtained up to concentrations of 40 ng mL(-1). The method was applied to the determination of the target compounds in human serum samples from 20 randomly selected anonymous individuals. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Reactivity of cosmetic UV filters towards skin proteins: model studies with Boc-lysine, Boc-Gly-Phe-Gly-Lys-OH, BSA and gelatin.

    Science.gov (United States)

    Stiefel, C; Schwack, W

    2014-12-01

    Organic UV filters are used as active ingredients in most sunscreens and also in a variety of daily care products. Their good (photo) stability is of special interest to guarantee protective function and to prevent interactions with the human skin. Due to the mostly electrophilic character of the UV filters, reactions with nucleophilic protein moieties like lysine side chains are conceivable. Prior studies showed that the UV filters octocrylene (OCR), butyl methoxydibenzoylmethane (BM-DBM), ethylhexyl salicylate (EHS), ethylhexyl methoxycinnamate (EHMC), benzophenone-3 (BP-3), ethylhexyl triazone (EHT) and dibenzoylmethane (DBM) were able to covalently bind to an HPTLC amino phase and the amino acid models ethanolamine and butylamine after slightly heating and/or radiation. Boc-protected lysine, the tetrapeptide Boc-Gly-Phe-Gly-Lys-OH, bovine serum albumin (BSA) and porcine gelatin were used as more complex models to determine the reactivity of the mentioned UV filters towards skin proteins under thermal or UV irradiation conditions. After gentle heating at 37°C, benzophenone imines were identified as reaction products of BP-3 and OCR with Boc-lysine and the tetrapeptide, whereas DBM and BM-DBM yielded enamines. For EHMC, a Michael-type reaction occurred, which resulted in addition of Boc-lysine or the tetrapeptide to the conjugated double bond. Ester aminolysis of EHS and EHT mainly afforded the corresponding amides. Reactions of the UV filters with BSA changed the UV spectrum of BSA, generally associated with an increase of the absorption strength in the UVA or UVB range. For all protein models, the UV filters showed an increasing reactivity in the order EHT < EHMC < EHS < BP-3 < OCR < DBM < BM-DBM. Especially the UV absorbers BM-DBM, OCR and BP-3, which are seen as common allergens or photoallergens, showed a high reactivity towards the different skin protein models. As the formation of protein adducts is recognized as important key element in the induction of

  18. Influence of Titanium Dioxide Particle Size on the Photostability of the Chemical UV-Filters Butyl Methoxy Dibenzoylmethane and Octocrylene in a Microemulsion

    Directory of Open Access Journals (Sweden)

    Jutta Kockler

    2014-06-01

    Full Text Available Sunscreen products often contain combinations of ultraviolet (UV-filters in order to achieve broad spectrum protection from exposure to sunlight. The inclusion of both chemical and physical UV-filters in these products, however, increases the possibility for both photolytic and photocatalytic reactions to occur. This study investigated the effect of titanium dioxide (TiO2 particle size on the photostability of the chemical UV-filters butyl methoxy dibenzoylmethane (BMDM and octocrylene (OC formulated in a microemulsion. The International Conference on Harmonisation (ICH Guideline Q1B for photostability testing of new active substances and medicinal products was applied. BMDM and OC in the microemulsion were irradiated with simulated sunlight in the presence of nano- (<25 nm and micro-TiO2 (~0.6 μm and their concentrations determined using a validated high performance liquid chromatography (HPLC method. For the combination of BMDM and OC, the photodegradation for BMDM was found to be 12% higher in the presence of nano-TiO2 as compared to that of the micro-TiO2. This enhanced photodegradation is attributed to the larger surface area of the nano-TiO2 and the increased generation of reactive oxygen species (ROS. Because of these findings, sunscreen products containing chemical UV-filters and nano-TiO2 should be regarded with caution, due to the potential loss of photoprotection.

  19. Ecotoxicological evaluation of four UV filters using marine organisms from different trophic levels Isochrysis galbana, Mytilus galloprovincialis, Paracentrotus lividus, and Siriella armata.

    Science.gov (United States)

    Paredes, E; Perez, S; Rodil, R; Quintana, J B; Beiras, R

    2014-06-01

    Due to the concern about the negative effects of exposure to sunlight, combinations of UV filters like 4-Methylbenzylidene-camphor (4-MBC), Benzophenone-3 (BP-3), Benzophenone-4 (BP-4) and 2-Ethylhexyl-4-methoxycinnamate (EHMC) are being introduced in all kind of cosmetic formulas. These chemicals are acquiring a concerning status due to their increasingly common use and the potential risk for the environment. The aim of this study is to assess the behaviour of these compounds in seawater, the toxicity to marine organisms from three trophic levels including autotrophs (Isochrysis galbana), herbivores (Mytilus galloprovincialis and Paracentrotus lividus) and carnivores (Siriella armata), and set a preliminary assessment of potential ecological risk of UV filters in coastal ecosystems. In general, EC50 results show that both EHMC and 4-MBC are the most toxic for our test species, followed by BP-3 and finally BP-4. The most affected species by the presence of these UV filters are the microalgae I. galbana, which showed toxicity thresholds in the range of μg L(-1) units, followed by S. armata>P. Lividus>M. galloprovincialis. The UV filter concentrations measured in the sampled beach water were in the range of tens or even hundreds of ng L(-1). The resulting risk quotients showed appreciable environmental risk in coastal environments for BP-3 and 4-MBC. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Determination of UV filters in both soluble and particulate fractions of seawaters by dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Benedé, J L; Chisvert, A; Salvador, A; Sánchez-Quiles, D; Tovar-Sánchez, A

    2014-02-17

    An analytical method to determine the total content (i.e., not only in the soluble fraction but also in the particulate one) of eight commonly used UV filters in seawater samples is presented for the first time. Dispersive liquid-liquid microextraction (DLLME) is used as microextraction technique to pre-concentrate the target analytes before their determination by gas chromatography-mass spectrometry (GC-MS). In order to release the UV filters from the suspended particles an ultrasound treatment is performed before DLLME. The ultrasound treatment time was studied in order to achieve a quantitative lixiviation of the target analytes. The type and volume of both disperser and extraction solvent, the sample volume, the pH and the ionic strength involved in the DLLME have been optimized to provide the best enrichment factors. Under the optimized conditions, the method was successfully validated showing good linearity, enrichment factors between 112 and 263 depending on the analyte, limits of detection and quantification in the low ng L(-1) range (10-30 ng L(-1) and 33-99 ng L(-1), respectively) and good intra- and inter-day repeatability (RSD UV filters in the particulate fraction that would have been ignored if only the soluble fraction had been considered. This fact shows that the UV filters are also accumulated in the suspended particles contained in water, what should be taken into account from an environmental standpoint. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Determination of the UV filters worldwide authorised in sunscreens by high-performance liquid chromatography. Use of cyclodextrins as mobile phase modifier.

    Science.gov (United States)

    Chisvert, A; Pascual-Martí, M C; Salvador, A

    2001-07-06

    Simultaneous determination of organic UV filters worldwide authorised in sunscreen formulations was performed by HPLC with UV spectrophotometric detection. The filters determined were: benzophenone-4, benzophenone-3, butyl methoxydibenzoylmethane, octyl dimethyl PABA, octyl methoxycinnamate, homosalate and octyl salicylate. A C18 stationary phase and an isocratic mobile phase of ethanol-water-acetic acid (70:29.5:0.5) containing 65.4 mM of hydroxypropyl-beta-cyclodextrin, were used with a flow-rate of 0.6 ml/min. UV measurements were carried out at 313 nm. The time required for the analysis was 20 min and the limits of detection were between 1.5 and 2.3 mg/l. The procedure proposed provides a green analytical method with a basic instrumental configuration, it is fast and accurate and does not involve highly toxic organic solvents.

  2. On-line in-syringe magnetic stirring assisted dispersive liquid-liquid microextraction HPLC--UV method for UV filters determination using 1-hexyl-3-methylimidazolium hexafluorophosphate as extractant.

    Science.gov (United States)

    Suárez, Ruth; Clavijo, Sabrina; Avivar, Jessica; Cerdà, Víctor

    2016-02-01

    An environmental friendly and fully automated method using in-syringe magnetic stirring assisted dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography has been developed for the determination of UV filters in environmental water samples. The main "green" features on this method are the use of an ionic liquid as extracting solvent, avoiding the use of chlorinated solvents, and the on-line microextraction, preconcentration, separation and detection minimizing the use of reagents and so the waste generation. After sample treatment, 20 µL of the organic droplet was injected onto the HPLC-UV system. Various parameters affecting the extraction efficiency were studied using multivariate optimization approach, including the quantity of extraction and dispersive solvents, extraction and sedimentation time, ionic strength and pH. Under optimized conditions, limits of detection were within the range of 0.08-12 µg/L, for 3.5 mL sample volume. Linearity ranges were up to 500 µg/L for the UV-filters studied. Furthermore, enrichment factors ranging from 11 to 23 folds were obtained. Intra- and inter-assay precisions were 6% and 8%, respectively. Finally, the proposed method was successfully applied to determine UV filters in surface seawater and swimming pool samples attaining satisfactory recoveries over the range of 89-114% and 86-107%, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. [Ultraviolet-visible (UV-Vis) and fluorescence spectral characteristics of soil dissolved organic matter (DOM) in typical agricultural watershed of Three Gorges Reservoir Region].

    Science.gov (United States)

    Wang, Qi-Lei; Jiang, Tao; Zhao, Zheng; Mu, Zhi-Jian; Wei, Shi-Qiang; Yan, Jin-Long; Liang, Jian

    2015-03-01

    As an important geo-factor to decide the environmental fate of pollutants in watershed, soil dissolved organic matter (DOM) sampled from a typical agricultural watershed in the Three Gorges Reservoir area was investigated using ultraviolet-visible (UV-Vis) and fluorescence spectroscopies, to analyze and discuss the effect of different land uses including forest, cropland, vegetable field and residence, on soil DOM geochemical characteristics. The results showed that significant differences in DOM samples amongst different land uses were observed, and DOM from forest had the highest aromaticity and humification degree, followed by DOM from cropland. Although DOM from vegetable field and residence showed the highest dissolved organic carbon (DOC) concentration (average values 0.81 g x kg(-1) and 0.89 g x kg(-1), respectively), but the aromaticity was lower indicating lower humification, which further suggested that the non-chromophoric component in these DOM samples contributed significantly to total DOM compositions. Additionally, in all DOM samples that were independent of land uses, fluorescence index (FI) values were between 1.4 (terrigenous) and 1.9 (authigenic) , evidently indicating both the allochthonous and autochthonous sources contributed to DOM characteristics. Meanwhile, r(T/C) values in most of samples were higher than 2.0, suggesting that soil DOM in this agricultural watershed was heavily affected by anthropogenic activities such as agricultural cultivation, especially, vegetable field was a good example. Additionally, sensitivities of different special spectral parameters for reflecting the differences of DOM characteristics amongst different land uses were not identical. For example, neither spectral slope ratio (S(R)) nor humification index (HIX) could clearly unveil the various geochemical characteristics of soil DOM from different sources. Thus, simple and single special spectral parameter cannot comprehensively provide the detailed information

  4. Confinement of Reactive Oxygen Species in an Artificial-Enzyme-Based Hollow Structure To Eliminate Adverse Effects of Photocatalysis on UV Filters.

    Science.gov (United States)

    Ju, Enguo; Dong, Kai; Wang, Zhenzhen; Zhang, Yan; Cao, Fangfang; Chen, Zhaowei; Pu, Fang; Ren, Jinsong; Qu, Xiaogang

    2017-09-27

    Skin cancers caused by UV irradiation have been a major public health problem. One simple and effective way to avoid the above detrimental effects is the use of UV-protective sunscreens. However, there has been considerable concern with the issue of the production of reactive oxygen species (ROS) through the photodegradation of commercial UV filters. Herein, for the first time, it is reported that the integration of ZnO nanoparticles and CeO x nanoparticles into hollow microspheres (ZnO/CeO x HMS) could provide broad-spectrum UV protection and scavenge generated ROS under UV irradiation. Benefiting from the cooperative effect of the hollow structure and the antioxidative activity of CeO x , ROS generated under UV irradiation could be confined to a limited space and effectively conversion into nontoxic molecules is catalyzed as a consequence of increased collision frequency. Therefore, both primary, direct UV-induced damage and secondary ROS toxicity could be greatly reduced. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Simultaneous determination of UV-filters and estrogens in aquatic invertebrates by modified quick, easy, cheap, effective, rugged, and safe extraction and liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    He, Ke; Timm, Anne; Blaney, Lee

    2017-08-04

    Ultraviolet-filters (UV-filters) and estrogens have attracted increased attention as contaminants of emerging concern (CECs) due to their widespread occurrence in the environment. Most of these CECs are hydrophobic and have the potential to accumulate in aquatic organisms. To date, co-analysis of UV-filters and estrogens has not been reported due, in part, to the complex environmental matrices. Here, a multi-residue method has been developed for simultaneous determination of five UV-filters and three estrogens in tissue from aquatic and marine organisms. The procedure involved a modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction with a novel reverse-solid-phase extraction (reverse-SPE) cleanup in place of dispersive-SPE, followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. The tissue mass, acetonitrile content, and salt conditions for QuEChERS extraction, along with the reverse-SPE cartridge material and elution conditions, were thoroughly investigated and optimized. Five UV-filters (i.e., 3-(4-methylbenzylidene) camphor, benzophenone-3, ethylhexylmethoxycinnamate, homosalate, and octocrylene) and three estrogens (i.e., estrone, 17β-estradiol, and 17α-ethinylestradiol) were simultaneously analyzed by taking advantage of wrong-way-round ionization in LC-MS/MS. The optimized analytical protocol exhibited good recoveries (>80%) for target compounds and enabled their detection at concentrations as low as 0.2ng/g in 50mg tissue samples. The method was applied to determine concentrations of target analytes in four invertebrates (i.e., Orconectes virilis, Procambarus clarkii, Crassostrea virginica, and Ischadium recurvum). All eight target analytes were detected at least once in the tissue samples, with the highest concentration being 399ng/g of homosalate in O. virilis. These results highlight the ubiquitous bioaccumulation of CECs in aquatic and marine invertebrates. Copyright © 2017 Elsevier B.V. All rights

  6. Removal of pharmaceuticals, polybrominated flame retardants and UV-filters from sludge by the fungus Trametes versicolor in bioslurry reactor.

    Science.gov (United States)

    Rodríguez-Rodríguez, Carlos E; Barón, Enrique; Gago-Ferrero, Pablo; Jelić, Aleksandra; Llorca, Marta; Farré, Marinella; Díaz-Cruz, M Silvia; Eljarrat, Ethel; Petrović, Mira; Caminal, Glòria; Barceló, Damià; Vicent, Teresa

    2012-09-30

    Conventional wastewater treatments are inefficient in the removal of many organic pollutants. The presence of these contaminants in the final sludge represents a source of environmental pollution due to the increasing use of biosolids in land application. A biotechnological approach which employed the fungus Trametes versicolor in a sludge-bioslurry reactor was assessed in order to remove several groups of emerging pollutants. Biological fungal activity was monitored by means of ergosterol and laccase determinations. Fifteen out of 24 detected pharmaceuticals were removed at efficiencies over 50% after the treatment, including eight completely degraded. Removal ranged between 16-53% and 22-100% for the brominated flame retardants and the UV-filters, respectively. Only two of all the detected compounds remained unchanged after the treatment. Although elimination results are promising, the toxicity of the final sludge increased after the treatment. This finding is contrary to the toxicity results obtained in similar treatments of sludge with T. versicolor in solid-phase. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Design and fabrication of UV band-pass filters based on SiO{sub 2}/Si{sub 3}N{sub 4} dielectric distributed bragg reflectors

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Jiangping; Gao, Wang; Liu, Bin, E-mail: bliu@nju.edu.cn; Cao, Xianlei; Tao, Tao; Xie, Zili; Zhao, Hong; Chen, Dunjun; Ping, Han; Zhang, Rong

    2016-02-28

    Graphical abstract: - Highlights: • Tandem dielectric distributed Bragg reflectors were fabricated as UV band-pass filters. • Varied center wavelengths and passband widths of filters were achieved successfully. • Transition layer between sub-layers can be proved by XPS analysis clearly. • The optical performance degradation was discussed by FDTD simulation in detail. - Abstract: We have designed one kind of optical filters based on double stacks of 13.5-pairs SiO{sub 2}/Si{sub 3}N{sub 4} dielectric distributed Bragg reflector (DDBR) structures, to realize the passband with different central wavelengths in ultraviolet (UV) range. These SiO{sub 2}/Si{sub 3}N{sub 4} multi-layers have been successfully fabricated on (0001) sapphire substrates by plasma-enhanced chemical vapor deposition (PECVD). The reflectance spectra measured by the UV–visible spectrometer manifest that a series of band-pass filters with fixed passband width of ∼30 nm and central passband varied from 310 nm to 370 nm have been obtained successfully. Besides, the other series of filters with passband width varied from 30 nm to 45 nm can be achieved. With good control of PECVD deposition parameters, all samples exhibit smooth surface with root mean square roughness less than 4.5 nm. Moreover, cross-section scanning electron microscope (SEM) images show these DDBR structures have good periodicity in accordance with the design, indicating that these band-pass filter structures are suitable for wavelength-window-selection UV photodetectors.

  8. NILU-UV multi-filter radiometer total ozone columns: Comparison with satellite observations over Thessaloniki, Greece.

    Science.gov (United States)

    Zempila, Melina Maria; Taylor, Michael; Koukouli, Maria Elissavet; Lerot, Christophe; Fragkos, Konstantinos; Fountoulakis, Ilias; Bais, Alkiviadis; Balis, Dimitrios; van Roozendael, Michel

    2017-07-15

    This study aims to construct and validate a neural network (NN) model for the production of high frequency (~1min) ground-based estimates of total ozone column (TOC) at a mid-latitude UV and ozone monitoring station in the Laboratory of Atmospheric Physics of the Aristotle University of Thessaloniki (LAP/AUTh) for the years 2005-2014. In the first stage of model development, ~30,000 records of coincident solar UV spectral irradiance measurements from a Norsk Institutt for Luftforskning (NILU)-UV multi-filter radiometer and TOC measurements from a co-located Brewer spectroradiometer are used to train a NN to learn the nonlinear functional relation between the irradiances and TOC. The model is then subjected to sensitivity analysis and validation. Close agreement is obtained (R 2 =0.94, RMSE=8.21 DU and bias=-0.15 DU relative to the Brewer) for the training data in the correlation of NN estimates on Brewer derived TOC with 95% of the coincident data differing by less than 13 DU. In the second stage of development, a long time series (≥1 million records) of high frequency (~1min) NILU-UV ground-based measurements are presented as inputs to the NN model to generate high frequency TOC estimates. The advantage of the NN model is that it is not site dependent and is applicable to any NILU input data lying within the range of the training data. GOME/ERS-2, SCIAMACHY/Envisat, OMI/Aura and GOME2/MetOp-A TOC records are then used to perform a precise cross-validation analysis and comparison with the NILU TOC estimates over Thessaloniki. All 4 satellite TOC dataset are retrieved using the GOME Direct Fitting algorithm, version 3 (GODFIT_v3), for reasons of consistency. The NILU TOC estimates within ±30min of the overpass times agree well with the satellite TOC retrievals with coefficient of determination in the range 0.88≤R 2 ≤0.90 for all sky conditions and 0.95≤R 2 ≤0.96 for clear sky conditions. The mean fractional differences are found to be -0.67%±2.15%, -1

  9. Organic UV filters inhibit multixenobiotic resistance (MXR) activity in Tetrahymena thermophila: investigations by the Rhodamine 123 accumulation assay and molecular docking.

    Science.gov (United States)

    Gao, Li; Yuan, Tao; Cheng, Peng; Zhou, Chuanqi; Ao, Junjie; Wang, Wenhua; Zhang, Haimou

    2016-09-01

    Multixenobiotic resistance (MXR) transporters, which belong to ATP-binding cassette (ABC) family proteins, are present in living organisms as a first line of defense system against xenobiotics and environmental contaminants. The effects of six organic UV filters (4-methyl -benzylidene camphor, 4-MBC; benzophenone-3, BP-3; butyl methoxydibenzoyl-methane, BM-DBM; ethylhexyl methoxy cinnamate, EHMC; octocrylene, OC and homosalate, HMS) on multixenobiotic resistance (MXR) in Tetrahymena thermophila were investigated in this study. It was found that 4-MBC, BP-3 and BM-DBM could significantly inhibit activity of the MXR system, causing concentration dependent accumulation of rhodamine 123; while EHMC, OC and HMS had weak MXR inhibition. The IC50 (50 % inhibition concentration) values of 4-MBC, BP-3 and BM-DBM were 23.54, 40.59 and 26.37 μM, respectively, with inhibitory potentials of 23.1, 13.4 and 20.6 % relative to verapamil (VER, a model inhibitor of P-glycoprotein). Our results firstly provide the evidence for UV filters inhibition effect on MXR in aquatic organisms. In addition, it was revealed by molecular docking analysis that the selected six UV filters can occupy the same binding site on T. thermophila P-gp as VER does; and form H-bonds with residues Ser 328 and/or Asn 281. This study raises the awareness of aquatic ecological risk from the organic UV filters exposure, as they would be involved in potentiating toxic effects by chemosensitizing.

  10. Widespread occurrence of bisphenol A diglycidyl ethers, p-hydroxybenzoic acid esters (parabens), benzophenone type-UV filters, triclosan, and triclocarban in human urine from Athens, Greece.

    Science.gov (United States)

    Asimakopoulos, Alexandros G; Thomaidis, Nikolaos S; Kannan, Kurunthachalam

    2014-02-01

    Biomonitoring of human exposure to bisphenol A diglycidyl ethers (BADGEs; resin coating for food cans), p-hydroxybenzoic acid esters (parabens; preservatives), benzophenone-type UV filters (BP-UV filters; sunscreen agents), triclosan (TCS; antimicrobials), and triclocarban (TCC; antimicrobials) has been investigated in western European countries and North America. Nevertheless, little is known about the exposure of Greek populations to these environmental chemicals. In this study, 100 urine samples collected from Athens, Greece, were analyzed by liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for the determination of total concentrations of five derivatives of BADGEs, six parabens and their metabolite (ethyl-protocatechuate), five derivatives of BP-UV filters, TCS, and TCC. Urinary concentrations of BADGEs, parabens, ethyl-protocatechuate, BP-UV filters, TCS and TCC (on a volume basis) ranged 0.3-20.9 (geometric mean: 0.9), 1.6-1010 (24.2), <2-71.0 (2.1), 0.5-1120 (4.4), <0.5-2580 (8.0) and <0.5-1.9 (0.6) ng/mL, respectively. All 19 target chemicals were found in urine, and the highest detection rates were observed for methyl paraben (100%), bisphenol A bis (2,3-dihydroxypropyl) ether (90%), ethyl paraben (87%), 2,4-dihydroxybenzophenone (78%), propyl paraben (72%), and TCS (71%). Estimated daily intakes (EDIurine), calculated on the basis of the measured urinary concentrations, ranged from 0.023 μg/kg bw/day for Σ5BADGEs to 31.4 μg/kg bw/day for Σ6Parabens. © 2013.

  11. Presence of UV filters in surface water and the effects of phenylbenzimidazole sulfonic acid on rainbow trout (Oncorhynchus mykiss) following a chronic toxicity test.

    Science.gov (United States)

    Grabicova, Katerina; Fedorova, Ganna; Burkina, Viktoriia; Steinbach, Christoph; Schmidt-Posthaus, Heike; Zlabek, Vladimir; Kocour Kroupova, Hana; Grabic, Roman; Randak, Tomas

    2013-10-01

    UV filters belong to a group of compounds that are used by humans and are present in municipal waste-waters, effluents from sewage treatment plants and surface waters. Current information regarding UV filters and their effects on fish is limited. In this study, the occurrence of three commonly used UV filters - 2-phenylbenzimidazole-5-sulfonic acid (PBSA), 2-hydroxy-4-methoxybenzophenone (benzophenone-3, BP-3) and 5-benzoyl-4-hydroxy-2-methoxy-benzenesulfonic acid (benzophenone-4, BP-4) - in South Bohemia (Czech Republic) surface waters is presented. PBSA concentrations (up to 13μgL(-1)) were significantly greater than BP-3 or BP-4 concentrations (up to 620 and 390ngL(-1), respectively). On the basis of these results, PBSA was selected for use in a toxicity test utilizing the common model organism rainbow trout (Oncorhynchus mykiss). Fish were exposed to three concentrations of PBSA (1, 10 and 1000µgL(-1)) for 21 and 42 days. The PBSA concentrations in the fish plasma, liver and kidneys were elevated after 21 and 42 days of exposure. PBSA increased activity of certain P450 cytochromes. Exposure to PBSA also changed various biochemical parameters and enzyme activities in the fish plasma. However, no pathological changes were obvious in the liver or gonads. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Simultaneous in-vial acetylation solid-phase microextraction followed by gas chromatography tandem mass spectrometry for the analysis of multiclass organic UV filters in water.

    Science.gov (United States)

    Vila, Marlene; Celeiro, Maria; Lamas, J Pablo; Garcia-Jares, Carmen; Dagnac, Thierry; Llompart, Maria

    2017-02-05

    UV filters are a class of emerging contaminants that are widely used in personal care products (PCPs) and that can be detected at low concentrations in the aquatic environment (ngL -1 ). Sensitive modern analytical methods are then mandatory to accurately analyze them. A methodology based on solid-phase-microextraction (SPME), considered as a 'Green Chemistry' technique, followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) has been developed for the simultaneous analysis of 14 UV filters of different chemical nature in environmental and recreational waters. In-vial low-cost derivatization was carried out to improve chromatographic performance of phenolic compounds. The extraction parameters (fiber coating, extraction mode, and salt addition) were optimized by means of experimental designs in order to achieve reliable conditions. Finally, the SPME-GC-MS/MS method was validated in terms of linearity, accuracy and precision with LODs in the low ngL -1 level. Its application to the analysis of 28 different samples including sea, river, spa, swimming pool, and aquapark waters, enabled the detection of 11 target UV filters at concentration levels up to 540μgL -1 , highlighting the presence of OCR in all analyzed samples and of 2EHMC (proposed to be considered as priority pollutant) in 79% of them. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Combination of retinyl palmitate and UV-filters: phototoxic risk assessment based on photostability and in vitro and in vivo phototoxicity assays.

    Science.gov (United States)

    Benevenuto, Carolina Gomes; Guerra, Lucas Offenbecker; Gaspar, Lorena Rigo

    2015-02-20

    This study aimed to assess the phototoxic potential of combined UV-filters and retinyl palmitate (RP) in the presence or not of bemotrizinol (BMTZ), employing photostability and in vitro and in vivo phototoxicity assays. The formulations tested contained octocrylene (OCT), octyl methoxycinnamate (OMC), benzophenone-3 (BZP-3) and RP (photostable) or octocrylene (OCT), octyl methoxycinnamate (OMC), avobenzone (AVO) and RP (less photostable). Both formulations were supplemented with bemotrizinol. Photostability was evaluated by exposing, or not, formulations spread on a glass plate to UVA/UVB irradiation. The resulting products were quantified by HPLC analysis. In vitro phototoxicity of UV-filters and combinations were evaluated using 3T3 viable monolayer fibroblast cultures submitted, or not, to irradiation according to OECD TG 432. In vivo photoallergy and photoxicity were assessed by clinical studies (photopatch test). Photostability assays showed that UV-filter bemotrizinol was a better photostabilizer for RP/benzophenone-3 than for RP/avobenzone. The in vitro phototoxicity of the combination RP/avobenzone was reduced by bemotrizinol. Clinical studies did not indicate phototoxic or photoallergenic potentials in all formulations tested. It is concluded that the 3T3 NRU phototoxicity test may be considered a supplementary assay in formulation developments, since it can detect chemically unstable and potentially phototoxic combinations. However, extrapolation of in vitro positive results to human photopatch tests may be performed only to a limited extent. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Sediments as a sink for UV filters and benzotriazoles: the case study of Upper Iguaçu watershed, Curitiba (Brazil).

    Science.gov (United States)

    Mizukawa, Alinne; Molins-Delgado, Daniel; de Azevedo, Júlio César Rodrigues; Fernandes, Cristóvão Vicente Scapulatempo; Díaz-Cruz, Silvia; Barceló, Damià

    2017-08-01

    Ingredients in home and personal care products, including UV filters and benzotriazoles, are high production volume chemicals extensively used in our daily life, despite several studies revealed their potential eco-toxicity and endocrine-disrupting capacity. Due to some features, such as high lipophilicity, low degradability, and persistence of many of these compounds, sediments can be considered a sink for them in the aquatic environment. In the present study, nine organic UV filters and three benzotriazoles were investigated for the first time in sediments from four urban rivers in Brazil. The contaminants were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results revealed that octocrylene (OC), etylhexyl-methoxycinnamate (EHMC), benzophenone-3 (oxybenzone, BP3), and benzotriazole (BZT) were the predominant compounds adsorbed on the sediments, with concentrations ranging from 5.6 to 322.2 ng g -1 dry weight. The results reported in this work constitute the first data on the accumulation of polar benzotriazoles and lipophilic organic UV filters in sediments from Brazil.

  15. Acute Toxicity and Ecological Risk Assessment of Benzophenone-3 (BP-3 and Benzophenone-4 (BP-4 in Ultraviolet (UV-Filters

    Directory of Open Access Journals (Sweden)

    Yang Du

    2017-11-01

    Full Text Available Ultraviolet (UV-absorbing chemicals (UV filters are used in personal care products for the protection of human skin and hair from damage by UV radiation. Although these substances are released into the environment in the production and consumption processes, little is known about their ecotoxicology effects. The acute toxicity and potential ecological risk of UV filters benzophenone-3 (BP-3 and benzophenone-4 (BP-4 on Chlorella vulgaris, Daphnia magna, and Brachydanio rerio were analyzed in the present study. The EC50 values (96 h of BP-3 and BP-4 on C. vulgaris were 2.98 and 201.00 mg/L, respectively. The 48 h-LC50 of BP-3 and BP-4 on D. magna were 1.09 and 47.47 mg/L, respectively. The 96 h-LC50 of BP-3 and BP-4 on B. rerio were 3.89 and 633.00 mg/L, respectively. The toxicity of a mixture of BP-3 and BP-4 on C. vulgaris, D. magna, and B. rerio all showed antagonistic effects. The induced predicted no-effect concentrations of BP-3 and BP-4 by the assessment factor method were 1.80 × 10−3 and 0.47 mg/L, respectively, by assessment factor (AF method, which were both lower than the concentrations detected in the environment at present, verifying that BP-3 and BP-4 remain low-risk chemicals to the aquatic ecosystem.

  16. Acute Toxicity and Ecological Risk Assessment of Benzophenone-3 (BP-3) and Benzophenone-4 (BP-4) in Ultraviolet (UV)-Filters.

    Science.gov (United States)

    Du, Yang; Wang, Wen-Qian; Pei, Zhou-Tao; Ahmad, Fahmi; Xu, Rou-Rou; Zhang, Yi-Min; Sun, Li-Wei

    2017-11-19

    Ultraviolet (UV)-absorbing chemicals (UV filters) are used in personal care products for the protection of human skin and hair from damage by UV radiation. Although these substances are released into the environment in the production and consumption processes, little is known about their ecotoxicology effects. The acute toxicity and potential ecological risk of UV filters benzophenone-3 (BP-3) and benzophenone-4 (BP-4) on Chlorella vulgaris , Daphnia magna , and Brachydanio rerio were analyzed in the present study. The EC 50 values (96 h) of BP-3 and BP-4 on C. vulgaris were 2.98 and 201.00 mg/L, respectively. The 48 h-LC 50 of BP-3 and BP-4 on D. magna were 1.09 and 47.47 mg/L, respectively. The 96 h-LC 50 of BP-3 and BP-4 on B. rerio were 3.89 and 633.00 mg/L, respectively. The toxicity of a mixture of BP-3 and BP-4 on C. vulgaris , D. magna , and B. rerio all showed antagonistic effects. The induced predicted no-effect concentrations of BP-3 and BP-4 by the assessment factor method were 1.80 × 10 -3 and 0.47 mg/L, respectively, by assessment factor (AF) method, which were both lower than the concentrations detected in the environment at present, verifying that BP-3 and BP-4 remain low-risk chemicals to the aquatic ecosystem.

  17. Tunable UV Filters

    Science.gov (United States)

    Bruner, Marilyn E. (Principal Investigator); Rosenberg, William A.

    1996-01-01

    This report describes an investigation intended to determine the practical short wavelength limit for Fabry-Perot etalons operating in the far ultraviolet. This portion of the investigation includes a design study of multilayer dielectric reflector coatings that would be required by such an etalon. Results of the study indicate that etalons may be made to operate at wavelengths as short as 121 nm.

  18. Gel Based Sunscreen Containing Surface Modified TiO2 Obtained by Sol-Gel Process: Proposal for a Transparent UV Inorganic Filter

    Directory of Open Access Journals (Sweden)

    Marina Paiva Abuçafy

    2016-01-01

    Full Text Available Inorganic UV filters, as titanium dioxide (TiO2, have become attractive because of their role in protecting the skin against the damage caused by the continuous exposure to the sun. However, their high refractive index, responsible for a white residue when applied on the skin, has led to the development of alternative inorganic materials, such as TiO2 nanoparticles. Thus, the aim of this study was the development of transparent and stable gel formulations containing surface modified TiO2 nanoparticles for application in sunscreens. Also, the physical and chemical properties of formulations containing TiO2 nanoparticles were evaluated. The UV absorption spectroscopy analyses indicated that the formulations containing TiO2 nanoparticles had a broad protection spectrum. The diffuse reflectance spectroscopy revealed that the use of PTSH surface modified TiO2 nanoparticles improved the transparency of the sunscreen formulations compared to that containing commercial ones. The rheology analyses showed that the amount of nanoparticles incorporated in the formulations influences the gel-like or liquid-like behavior. The results showed that the surface modified TiO2 nanoparticles are a promising innovative UV filter and the formulations containing these nanoparticles are interesting candidates for being used as sunscreen.

  19. Air-assisted dispersive liquid-liquid microextraction based on a new hydrophobic deep eutectic solvent for the preconcentration of benzophenone-type UV filters from aqueous samples.

    Science.gov (United States)

    Ge, Dandan; Zhang, Yi; Dai, Yixiu; Yang, Shumin

    2017-12-28

    Deep eutectic solvents are considered as new and green solvents that can be widely used in analytical chemistry such as microextraction. In the present work, a new dl-menthol-based hydrophobic deep eutectic solvent was synthesized and used as extraction solvents in an air-assisted dispersive liquid-liquid microextraction method for preconcentration and extraction of benzophenone-type UV filters from aqueous samples followed by high-performance liquid chromatography with diode array detection. In an experiment, the deep eutectic solvent formed by dl-menthol and decanoic acid was added to an aqueous solution containing the UV filters, and then the mixture was sucked up and injected five times by using a glass syringe, and a cloudy state was achieved. After extraction, the solution was centrifuged and the upper phase was subjected to high-performance liquid chromatography for analysis. Various parameters such as the type and volume of the deep eutectic solvent, number of pulling, and pushing cycles, solution pH and salt concentration were investigated and optimized. Under the optimum conditions, the developed method exhibited low limits of detection and limits of quantitation, good linearity, and precision. Finally, the proposed method was successfully applied to determine the benzophenone-type filters in environmental water samples with relative recoveries of 88.8-105.9%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. The UV-filter benzophenone-1 inhibits 17beta-hydroxysteroid dehydrogenase type 3: Virtual screening as a strategy to identify potential endocrine disrupting chemicals.

    Science.gov (United States)

    Nashev, Lyubomir G; Schuster, Daniela; Laggner, Christian; Sodha, Seloni; Langer, Thierry; Wolber, Gerhard; Odermatt, Alex

    2010-04-15

    The prevalence of male reproductive disorders and testicular cancer is steadily increasing. Because the exposure to chemicals disrupting natural hormone action has been associated with these diseases, it is important to identify endocrine disrupting chemicals (EDCs) and their targets of action. Here, a 3D-structural database that can be applied for virtual screening approaches to facilitate the identification of EDCs was constructed. The database was screened using pharmacophores of 17beta-hydroxysteroid dehydrogenase type 3 (17beta-HSD3), which catalyzes the last step of testosterone synthesis in testicular Leydig cells and plays an essential role during male sexual development. Among other chemicals, benzophenone (BP) UV-filters were predicted as potential 17beta-HSD3 inhibitors. Biological analyses revealed (2,4-dihydroxyphenyl)-phenylmethanone (also known as benzophenone-1, BP-1) as an inhibitor of human 17beta-HSD3 (IC(50) 1.05microM). BP-1 also efficiently blocked conversion of androstenedione to testosterone by mouse and rat 17beta-HSD3 in whole-organ enzyme assays. Moreover, BP-1 antagonized the testosterone-dependent activation of androgen receptors (IC(50) 5.7microM), suggesting synergistic anti-androgenic effects of BP-1 by preventing testosterone formation and blocking receptor activation. In addition, analyses of several commonly used UV-filters on estrogen- and androgen-metabolizing 17beta-HSD enzymes revealed 3-benzylidene camphor (3-BC) and 4-methylbenzylidene camphor (4-MBC) as low micromolar 17beta-HSD2 inhibitors. In conclusion, screening of virtual chemical structure libraries can facilitate the identification of compounds interfering with hormone action. The potential disruption of 17beta-HSD enzyme function by the UV-filters BP-1, 3-BC and 4-MBC requires further investigation and should be considered for safety assessment of these chemicals. 2009 Elsevier Inc. All rights reserved.

  1. Effects of in vivo exposure to UV filters (4-MBC, OMC, BP-3, 4-HB, OC, OD-PABA) on endocrine signaling genes in the insect Chironomus riparius.

    Science.gov (United States)

    Ozáez, Irene; Martínez-Guitarte, José Luis; Morcillo, Gloria

    2013-07-01

    There is increasing evidence indicating that several UV filters might have endocrine disruptive effects. Numerous studies have evaluated hormonal effects in vertebrates, mainly reporting estrogenic and androgenic activities in mammals and fishes. There is only limited knowledge about potential endocrine activity in invertebrate hormonal systems. In this work, the effects on endocrine signaling genes of six frequently used UV filters were investigated in Chironomus riparius, a reference organism in aquatic toxicology. The UV filters studied were: octyl-p-methoxycinnamate (OMC) also called 2-ethylhexyl-4-methoxycinnamate (EHMC); 4-methylbenzylidene camphor (4-MBC); benzophenone-3 (BP-3); 4-hidroxybenzophenone (4-HB); octocrylene (OC); and octyldimethyl-p-aminobenzoate (OD-PABA). After in vivo exposure at different dosages, expression levels of the genes coding for the ecdysone receptor (EcR), the ultraspiracle (usp, ortholog of the RXR) and the estrogen-related receptor (ERR) were quantified by Real Time PCR. The EcR gene was significantly upregulated by 4-MBC, OMC/EHMC and OD-PABA, with a dose-related response following 24h exposure. In contrast, the benzophenones, BP-3 and 4-HB, as well as OC did not alter this gene at the same exposure conditions. The transcription profiles of the usp and ERR genes were not significantly affected, except for BP-3 that inhibited the usp gene at the highest concentration. To our knowledge, this is the first experimental evidence in invertebrates of a direct effect of UV filters on endocrine-related genes, and is consistent with the known effects on vertebrate hormonal receptor genes. The capability of 4-MBC, OMC/EHMC and OD-PABA to stimulate the expression of the ecdysone receptor, a key transcription factor for the ecdysone-genomic response in arthropods, suggests the possibility of a broad and long-term effect on this hormonal pathway. These findings strengthen the need for further research about the ecotoxicological implications

  2. Effects of pre- and postnatal exposure to the UV-filter Octyl Methoxycinnamate (OMC) on the reproductive, auditory and neurological development of rat offspring

    DEFF Research Database (Denmark)

    Petersen, Marta Axelstad; Boberg, Julie; Hougaard, Karin Sørig

    2011-01-01

    Octyl Methoxycinnamate (OMC) is a frequently used UV-filter in sunscreens and other cosmetics. The aim of the present study was to address the potential endocrine disrupting properties of OMC, and to investigate how OMC induced changes in thyroid hormone levels would be related to the neurological......, postnatal growth and timing of sexual maturation were assessed. On postnatal day 16, gene expression in prostate and testes, and weight and histopathology of the thyroid gland, liver, adrenals, prostate, testes, epididymis and ovaries were measured. After weaning, offspring were evaluated in a battery...... through usage of sunscreens and other cosmetics....

  3. Simultaneous determination of multiclass preservatives including isothiazolinones and benzophenone-type UV filters in household and personal care products by micellar electrokinetic chromatography.

    Science.gov (United States)

    Lopez-Gazpio, Josu; Garcia-Arrona, Rosa; Millán, Esmeralda

    2015-04-01

    In this work, a simple and reliable micellar electrokinetic chromatography method for the separation and quantification of 14 preservatives, including isothiazolinones, and two benzophenone-type UV filters in household, cosmetic and personal care products was developed. The selected priority compounds are widely used as ingredients in many personal care products, and are included in the European Regulation concerning cosmetic products. The electrophoretic separation parameters were optimized by means of a modified chromatographic response function in combination with an experimental design, namely a central composite design. After optimization of experimental conditions, the BGE selected for the separation of the targets consisted of 60 mM SDS, 18 mM sodium tetraborate, pH 9.4 and 10% v/v methanol. The MEKC method was checked in terms of linearity, LODs and quantification, repeatability, intermediate precision, and accuracy, providing appropriate values (i.e. R(2) ≥ 0.992, repeatability RSD values ˂9%, and accuracy 90-115%). Applicability of the validated method was successfully assessed by quantifying preservatives and UV filters in commercial consumer products. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Identification, characteristics and human exposure assessments of triclosan, bisphenol-A, and four commonly used organic UV filters in indoor dust collected from Shanghai, China.

    Science.gov (United States)

    Ao, Junjie; Yuan, Tao; Ma, Yuning; Gao, Li; Ni, Ni; Li, Dan

    2017-10-01

    Indoor dust is a very significant medium to understand human exposure of emerging contaminants. A novel and robust analytical method to measure the amounts of six personal care products (PCPs) (triclosan, bisphenol-A and four commonly used organic ultraviolet (UV) filters) simultaneously in indoor dust is developed in this paper. Target analytes were extracted using accelerated solvent extraction. After sample cleanup by solid-phase extraction (SPE), the extracts were derivatized and analyzed using gas chromatography-tandem mass spectrometry. The method detection limits achieves 0.16-0.62 pg g -1 (except for 4-methylbenzylidene camphor with 3800 pg g -1 ). The method was successfully applied to the analysis of 110 indoor dust samples from Shanghai, China. Results showed that the PCPs were found in most of the samples analyzed. The concentrations of the most analytes are relatively lower than those reported in USA, Japan, and European countries. The median concentration of octocrylene (OC) (1170.4 ng g -1 ) was found to be nearly 5-10 times higher than those of other analytes. The significantly higher concentration of ∑PCPs was observed in indoor dusts from residences than from offices (P UV filters in China. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Determination of selected UV filters in indoor dust by matrix solid-phase dispersion and gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Negreira, N; Rodríguez, I; Rubí, E; Cela, R

    2009-07-31

    A simple, inexpensive sample preparation procedure, based on the matrix solid-phase dispersion (MSPD) technique, for the determination of six UV filters: 2-ethylhexyl salicylate (EHS), 3,3,5-trimethylcyclohexyl salicylate (Homosalate, HMS), 3-(4-methylbenzylidene) camphor (4-MBC), isoamyl-p-methoxycinnamate (IAMC), 2-ethylhexyl-p-methoxycinnamate (EHMC) and octocrylene (OCR), in dust from indoor environments is presented and the influence of several operational parameters on the extraction performance discussed. Under the final working conditions, sieved samples (0.5 g) were mixed with the same amount of anhydrous sodium sulphate and dispersed with 2 g of octadecyl bonded silica (C18) in a mortar with a pestle. This blend was transferred to a polypropylene solid-phase extraction cartridge containing 2 g of activated silica, as the clean-up co-sorbent. The cartridge was first rinsed with 5 mL of n-hexane and the analytes were then recovered with 4 mL of acetonitrile. This extract was adjusted to 1 mL, filtered and the compounds were determined by gas chromatography combined with tandem mass spectrometry (GC-MS/MS). Recoveries for samples spiked at two different concentrations ranged between 77% and 99%, and the limits of quantification (LOQs) of the method between 10 and 40 ng g(-1). Analysis of settled dust from different indoor areas, including private flats, public buildings and vehicle cabins, showed that EHMC and OCR were ubiquitous in this matrix, with maximum concentrations of 15 and 41 microg g(-1), respectively. Both UV filters were also quantified in dust reference material SRM 2585 for first time. EHS, 4-MBC and IAMC were detected in some of the analyzed samples, although at lower concentrations than EHMC and OCR.

  6. The response of silicon PNCCD sensors with aluminium on-chip filter to visible light, UV- and X-ray radiation

    Energy Technology Data Exchange (ETDEWEB)

    Granato, Stefanie

    2012-10-18

    There are various scientific applications, from astronomical observations to free electron lasers, that make use of X-ray semiconductor detectors like PNCCDs. The PNCCD is a pixelized semiconductor detector for simultaneous X-ray imaging and spectroscopy. For the seven PNCCD cameras of the eROSITA space telescope, a radiation entrance window including an on-chip optical blocking filter has been designed. The blocking filter is a necessity to minimize electron generation by visible light and UV radiation affecting X-ray spectroscopy. A PNCCD with such a blocking filter has not been used so far in astronomy. The following work deals with the analysis of the response of PNCCDs with on-chip filter. This includes the study of photon absorption and emission processes as well as the transport of electrons inside the detector entrance window. Furthermore it comprises the experimental characterization of the detector properties regarding the attenuation of light as well as their X-ray spectral redistribution function and quantum efficiency. With the ability to reveal the involved physical processes, the PNCCD is subject of analysis and measurement device at the same time. In addition to the results of the measurements, simulations of the solid state physics inside the detector are presented. A Geant4 Monte-Carlo code is extended by the treatment of charge loss in the entrance window and is verified by comparison with experimental data. Reproducing the chain of processes from photon absorption to charge collection, this work provides a detailed understanding of the formation of PNCCD spectra. The spectral features observed in the measurements are attributed to their point of origin inside the detector volume and explained by the model. The findings of this work allow high precision analysis of spectra of silicon detectors, e.g. of the eROSITA data, based on the presented detailed spectral response model.

  7. The response of silicon PNCCD sensors with aluminium on-chip filter to visible light, UV- and X-ray radiation

    International Nuclear Information System (INIS)

    Granato, Stefanie

    2012-01-01

    There are various scientific applications, from astronomical observations to free electron lasers, that make use of X-ray semiconductor detectors like PNCCDs. The PNCCD is a pixelized semiconductor detector for simultaneous X-ray imaging and spectroscopy. For the seven PNCCD cameras of the eROSITA space telescope, a radiation entrance window including an on-chip optical blocking filter has been designed. The blocking filter is a necessity to minimize electron generation by visible light and UV radiation affecting X-ray spectroscopy. A PNCCD with such a blocking filter has not been used so far in astronomy. The following work deals with the analysis of the response of PNCCDs with on-chip filter. This includes the study of photon absorption and emission processes as well as the transport of electrons inside the detector entrance window. Furthermore it comprises the experimental characterization of the detector properties regarding the attenuation of light as well as their X-ray spectral redistribution function and quantum efficiency. With the ability to reveal the involved physical processes, the PNCCD is subject of analysis and measurement device at the same time. In addition to the results of the measurements, simulations of the solid state physics inside the detector are presented. A Geant4 Monte-Carlo code is extended by the treatment of charge loss in the entrance window and is verified by comparison with experimental data. Reproducing the chain of processes from photon absorption to charge collection, this work provides a detailed understanding of the formation of PNCCD spectra. The spectral features observed in the measurements are attributed to their point of origin inside the detector volume and explained by the model. The findings of this work allow high precision analysis of spectra of silicon detectors, e.g. of the eROSITA data, based on the presented detailed spectral response model.

  8. Global gene expression profile induced by the UV-filter 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC) in zebrafish (Danio rerio)

    Energy Technology Data Exchange (ETDEWEB)

    Zucchi, Sara [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gruendensrasse 40, CH-4132 Muttenz (Switzerland); Oggier, Daniela M. [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gruendensrasse 40, CH-4132 Muttenz (Switzerland); University of Zuerich, Institute of Plant Biology, Division of Limnology, 8802 Kilchberg (Switzerland); Fent, Karl, E-mail: karl.fent@fhnw.ch [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gruendensrasse 40, CH-4132 Muttenz (Switzerland); Swiss Federal Institute of Technology Zuerich (ETH Zuerich), Department of Environmental Sciences, 8092 Zuerich (Switzerland)

    2011-10-15

    Residues of the UV-filter 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC) are ubiquitously found in aquatic biota but potential adverse effects in fish are fairly unknown. To identify molecular effects and modes of action of EHMC we applied a gene expression profiling in zebrafish using whole genome microarrays. Transcriptome analysis and validation of targeted genes were performed after 14 days of exposure of male zebrafish. Concentrations of 2.2 {mu}g/L and 890 {mu}g/L EHMC lead to alteration of 1096 and 1137 transcripts, respectively, belonging to many pathways. Genes involved in lipid metabolism and estrogenic pathway (vtg1), lipid biosynthesis (ptgds), vitamin A metabolic process (rbp2a), DNA damage and apoptosis (gadd45b), and regulation of cell growth (igfbp1a) were investigated by qRT-PCR analysis in whole body, liver, brain and testis. The analysis showed tissue-specific gene profiles and revealed that EHMC slightly affects the transcription of genes involved in hormonal pathways including vtg1, esr1, esr2b, ar, cyp19b and hsd17{beta}3. - Highlights: > The UV-filter EHMC accumulates in biota and shows expressional changes in fish. > Molecular effects of EHMC are demonstrated by microarrays and qRT-PCR in zebrafish. > Expressional changes in zebrafish occur at environmentally relevant concentrations. > The expressional changes point to interference of EHMC with the sex hormone system. > Additionally, many pathways are affected demonstrating multiple activities of EHMC. - Gene expression changes by 2-ethyl-hexyl-4-trimethoxycinnamate in zebrafish.

  9. Global gene expression profile induced by the UV-filter 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC) in zebrafish (Danio rerio)

    International Nuclear Information System (INIS)

    Zucchi, Sara; Oggier, Daniela M.; Fent, Karl

    2011-01-01

    Residues of the UV-filter 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC) are ubiquitously found in aquatic biota but potential adverse effects in fish are fairly unknown. To identify molecular effects and modes of action of EHMC we applied a gene expression profiling in zebrafish using whole genome microarrays. Transcriptome analysis and validation of targeted genes were performed after 14 days of exposure of male zebrafish. Concentrations of 2.2 μg/L and 890 μg/L EHMC lead to alteration of 1096 and 1137 transcripts, respectively, belonging to many pathways. Genes involved in lipid metabolism and estrogenic pathway (vtg1), lipid biosynthesis (ptgds), vitamin A metabolic process (rbp2a), DNA damage and apoptosis (gadd45b), and regulation of cell growth (igfbp1a) were investigated by qRT-PCR analysis in whole body, liver, brain and testis. The analysis showed tissue-specific gene profiles and revealed that EHMC slightly affects the transcription of genes involved in hormonal pathways including vtg1, esr1, esr2b, ar, cyp19b and hsd17β3. - Highlights: → The UV-filter EHMC accumulates in biota and shows expressional changes in fish. → Molecular effects of EHMC are demonstrated by microarrays and qRT-PCR in zebrafish. → Expressional changes in zebrafish occur at environmentally relevant concentrations. → The expressional changes point to interference of EHMC with the sex hormone system. → Additionally, many pathways are affected demonstrating multiple activities of EHMC. - Gene expression changes by 2-ethyl-hexyl-4-trimethoxycinnamate in zebrafish.

  10. A new carbon-based magnetic material for the dispersive solid-phase extraction of UV filters from water samples before liquid chromatography-tandem mass spectrometry analysis.

    Science.gov (United States)

    Piovesana, Susy; Capriotti, Anna Laura; Cavaliere, Chiara; La Barbera, Giorgia; Samperi, Roberto; Zenezini Chiozzi, Riccardo; Laganà, Aldo

    2017-07-01

    Magnetic solid-phase extraction is one of the most promising new extraction methods for liquid samples before ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. Several types of materials, including carbonaceous ones, have been prepared for this purpose. In this paper, for the first time, the preparation, characterization, and sorption capability of Fe 3 O 4 -graphitized carbon black (mGCB) composite toward some compounds of environmental interest were investigated. The synthesized mGCB consisted of micrometric GCB particles with 55 m 2  g -1 surface area bearing some carbonyl and hydroxyl functionalities and the surface partially decorated by Fe 3 O 4 microparticles. The prepared mGCB was firstly tested as an adsorbent for the extraction from surface water of 50 pollutants, including estrogens, perfluoroalkyl compounds, UV filters, and quinolones. The material showed good affinity to many of the tested compounds, except carboxylates and glucoronates; however, some compounds were difficult to desorb. Ten UV filters belonging to the chemical classes of benzophenones and p-aminobenzoates were selected, and parameters were optimized for the extraction of these compounds from surface water before UHPLC-MS/MS determination. Then, the method was validated in terms of linearity, trueness, intra-laboratory precision, and detection and quantification limits. In summary, the method performance (trueness, expressed as analytical recovery, 85-114%; RSD 5-15%) appears suitable for the determination of the selected compounds at the level of 10-100 ng L -1 , with detection limits in the range of 1-5 ng L -1 . Finally, the new method was compared with a published one, based on conventional solid-phase extraction with GCB, showing similar performance in real sample analysis. Graphical Abstract Workflow of the analytical method based on magnetic solid-phase extraction followed by LC-MS/MS determination.

  11. Occurrence of UV filters, fragrances and organophosphate flame retardants in municipal WWTP effluents and their removal during membrane post-treatment.

    Science.gov (United States)

    Krzeminski, P; Schwermer, C; Wennberg, A; Langford, K; Vogelsang, C

    2017-02-05

    Membrane filtration using ultrafiltration (UF), nanofiltration (NF) or reverse osmosis (RO) membranes was evaluated as an efficient effluent polishing step at municipal wastewater treatment plants (WWTPs) for the removal of selected contaminants of emerging concern and for improvement of water quality according to water reuse requirements. In samples collected at two largest WWTPs in Norway, 12 out of 14 selected personal care products and organophosphate flame retardants (OPFRs) were found above analytical detection limit. The highest concentrations were observed for BP3, OC (UV filters), HHCB, AHTN (fragrances), TCPP and TBP (OPFRs), exceeding the predicted no-effect concentration for BP3 in one sample and AHTN in five samples. Independently of the membrane type used, membrane filtration effectively (>60%) removed BP3, UV-329, OC, HHCB, AHTN and DBPP. However, UF was insufficient (<20%) for removal of DEET, TCPP and TCEP. UF was sufficient to remove 30-50% of COD, 80-95% of TP, up to 30% of TN and NH 4 , and a min of 2log reduction of E. coli. Water quality improved further with application of NF and RO. The results indicate that membrane filtration can be effective post-treatment to improve overall water quality and a measure to reduce potential risk in the receiving aquatic environment. Copyright © 2016 The Author(s). Published by Elsevier B.V. All rights reserved.

  12. Pityriacitrin--a potent UV filter produced by Malassezia furfur and its effect on human skin microflora.

    Science.gov (United States)

    Machowinski, Angelika; Krämer, Hans-Joachim; Hort, Wiebke; Mayser, Peter

    2006-09-01

    In Malassezia furfur, tryptophan as the main nitrogen source induces production of the potent ultraviolet-absorbing indole compound pityriacitrin. An in vitro study about the effects of pityriacitrin on other human skin microorganisms is presented, with special focus on Candida albicans and staphylococci in which its toxicity and UV-protective capacity were investigated. Candida albicans was irradiated with UVB light either in the presence or in the absence of pityriacitrin (11 mmol) and the growth rate was determined. A UVB dose of 1 J cm(-2) caused death of the fungi without pityriacitrin, whereas those in the presence of pityriacitrin showed almost unaffected growth. A diffusion test in staphylococci revealed no antibiotic effects of pityriacitrin. For testing of an ultraviolet-protective effect, staphylococci were either inoculated and irradiated in a plate model for visual assessment of growth or inoculated and irradiated in square quartz cylinders for quantitative measurement of cell density, each time in the absence or presence of pityriacitrin. Cell density of the bacterial suspensions exhibited nearly no influence of pityriacitrin on growth rates, while again a UV-protective effect was observed. In summary, pityriacitrin has an ultraviolet-protective effect on Candida albicans and staphylococci with no toxicity in the range tested.

  13. Photodegradation of the UV filter ethylhexyl methoxycinnamate under ultraviolet light: Identification and in silico assessment of photo-transformation products in the context of grey water reuse.

    Science.gov (United States)

    Jentzsch, F; Olsson, O; Westphal, J; Reich, M; Leder, C; Kümmerer, K

    2016-12-01

    To prevent water shortages in the future and to reduce domestic water consumption, decentralized grey water (GW) reuse has become increasingly important. This water has, however, to be free of pollutants. Conventional treatment of GW does not fully eliminate micropollutants such as the UV filter substance ethylhexyl methoxycinnamate (EHMC). EHMC, which is commonly used in sunscreens and personal care products, is an endocrine disruptor and shows potential to bioaccumulation, which is also reflected in its low water solubility. Photolysis has been proposed as an alternative treatment method for other micropollutants, but it is not clear yet whether it can also be used to eliminate EHMC. One goal of this study was to better understand the basic pathways involved in this process. It aimed to identify photo-transformation products (photo-TPs) by using, in the test conditions, an initial concentration of EHMC higher than those expected in the environment. Acetonitrile (ACN) was added in low concentrations to the aqueous solution to overcome the low aquatic solubility of EHMC. The influence of this co-solvent on the degradation kinetics was studied. The photolysis experiments were carried out using a medium pressure mercury lamp, which emits UV light in the range of 200-400nm. The quantum yield of the photolysis of EHMC was 0.0042 and 0.0023mol·Einstein -1 (for 0.2 and 0.5% ACN (v/v), respectively), and the relative and absolute UV photon fluxes were determined. HPLC was used to monitor the elimination kinetics of EHMC, which followed first-order kinetics. The results of LC-MS n analyses revealed that beside others, several oxidized and hydroxylized EHMC isomers were formed as photo-TPs in aqueous solution. Using a set of in silico quantitative structure-activity relationship (QSAR) models, this study also offered new insights concerning the environmental fate and toxicity of the TPs of EHMC. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Concentrations of the UV filter ethylhexyl methoxycinnamate in the aquatic compartment: a comparison of modelled concentrations for Swiss surface waters with empirical monitoring data.

    Science.gov (United States)

    Straub, Jürg Oliver

    2002-05-10

    UV filters in sunscreens and cosmetics protect the skin from damage through UV radiation. Many tonnes per year of UV filters are being used in Europe and will be present, at least seasonally, in detectable concentrations in surface waters similar to common pharmaceutically active substances. Predicted environmental concentrations (PECs) of ethylhexyl methoxycinnamate (EHMC; CAS 5466-77-3) were extrapolated for Switzerland, taking into consideration substance-specific environmental fate data and marketing estimates, by crude worst-case reckoning and by applying two environmental models (Mackay Level III; USES 3.0), both configured for Swiss hydrological and area data. By worst-case reckoning the summer PEC is 70.8-81.3 ng/l while for the remaining 8 months of the year the PEC is 13.1-15.1 ng/l. The Level III model results in concentrations of 2.4 ng/l during the summer and 0.44 ng/l during the rest of the year, while the USES 3.0 model gives an average PEC for the whole year of 7.6 ng/l. Pooling summer monitoring data (90 single analyses) from the River Rhine below Basel in the year 1997 (Water Protection Board of Basel) and from Lakes Zurich and Hüttner in 1998 (Poiger et al., in preparation) allowed a derivation of a probabilistic median concentration of 4.6 ng/l, a 95th-percentile concentration of 18.6 ng/l and a 99th-percentile concentration of 33.5 ng/l. The 6-fold range from the median value to the maximum calls for caution in interpreting published monitoring concentrations. Comparison of modelled PECs with realistic median concentrations shows that crude reckoning overestimates actual concentrations by a factor of about 10, probably through insufficient consideration of (further) degradation of EHMC in sewage works, surface waters, sediments or river banks. Both computer models, in contrast, are within the same order of magnitude as the actual summer concentrations. Based on the available data, both these environmental fate and distribution models give

  15. Construction of a portable sample preparation device with a magnetic poly(methacrylic acid-co-ethylene dimethacrylate) monolith as the extraction medium and its application in the enrichment of UV filters in water samples.

    Science.gov (United States)

    Li, Jing; Xu, Li; Yu, Qiong-Wei; Shi, Zhi-Guo; Zhang, Ting; Liu, Yan

    2014-10-01

    A portable sample preparation device with a magnetic polymer monolith as the extraction medium was constructed. The monolith was synthesized by polymerizing methacrylic acid and ethylene dimethacrylate around a cylindrical magnet. In this way, the monolith with a magnetic core could be readily attached to the extraction device by magnetism. The constructed device was evaluated for the enrichment of UV filters in water samples, followed by high-performance liquid chromatographic analysis. The extraction efficiency for the targets was satisfactory with no matrix interference. Good linearities were obtained for the UV filters with the correlation coefficients >0.9986. The limits of detection and quantification for the UV filters were 0.3-0.8 and 1.0-2.4 ng/mL, respectively. The recoveries of the UV filters from the spiked water samples at the concentration of 100 ng/mL were 95.3-101.7%, with relative standard deviations <10%. Accordingly, the proposed portable device was demonstrated to be suitable for on-site simultaneous sampling, purification, and preconcentration within a single step. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. In situ growth and phenyl functionalization of titania nanoparticles coating for solid-phase microextraction of ultraviolet filters in environmental water samples followed by high performance liquid chromatography-UV detection.

    Science.gov (United States)

    Li, Li; Guo, Ruibin; Li, Yi; Guo, Mei; Wang, Xuemei; Du, Xinzhen

    2015-03-31

    Based on TiO2-nanoparticles coating fabricated by a one-step anodization method on titanium wire substrate, a novel phenyl functionalized solid-phase microextraction (SPME) fiber coating was prepared by simple and rapid in situ chemical assembling technique between the fiber surface titanol groups and trichlorophenylsilane reaction. The as-fabricated fiber exhibited good extraction capability for some UV filters and was employed to determine the ultraviolet (UV) filters in combination with high performance liquid chromatography-UV detection (HPLC-UV). The main parameters affecting extraction performance were investigated and optimized. Under the optimized conditions, the developed method was applied to detect several UV filters at trace concentration levels with only 8 mL of sample volume. They were determined in the range from 0.005 to 25 μg L(-1) with detection limits (S/N=3) from 0.1 to 50 ng L(-1). The relative standard deviations (RSDs) for single fiber repeatability varied from 4.6 to 6.5% (n=5) and fiber-to-fiber reproducibility (n=5) ranged from 5.5 to 9.1%. The linear ranges spanned two-four magnitudes with correlation coefficients above 0.9990. Five real water samples including four Yellow River water samples and one rain water sample were determined sensitively with good recoveries ranging from 86.2 to 105.5%. The functionalized fiber coating performed good reproducible manner, high mechanical strength, good stability and long service life. Moreover, this study proposed an efficient sample pretreatment method for the determination of UV filters from environmental water samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Effects of a 5-day treatment with the UV-filter octyl-methoxycinnamate (OMC) on the function of the hypothalamo-pituitary-thyroid function in rats.

    Science.gov (United States)

    Klammer, Holger; Schlecht, Christiane; Wuttke, Wolfgang; Schmutzler, Cornelia; Gotthardt, Inka; Köhrle, Josef; Jarry, Hubertus

    2007-09-05

    Octyl-methoxycinnamate (OMC) is one of the most frequently used UV-filters in sunscreens to protect the skin against the noxious influence of UV radiation. Recently, OMC was suspected to act as an "endocrine active chemical" (EAC) with estrogenic actions. While EACs have been investigated thoroughly for interference with reproductive function in mammalians, surprisingly little efforts have been made to investigate an interference of EACs with the hypothalamo-pituitary-thyroid (HPT) axis despite the expression of estrogen receptors in all parts of this axis. Therefore, we conducted an in vivo study with ovariectomised rats treated for 5 days with different doses of OMC or 17beta-estradiol (E2) as a control. Determined parameters comprised serum levels of TSH, T4 and T3, hypothalamic TRH mRNA expression, protein-expression of the sodium-iodide-symporter (NIS) and the TSH receptor and the activities of thyroid peroxidase (TPO) in the thyroid and the T3-responsive hepatic type I 5'deiodinase (Dio1) in the liver. While E2 did not affect TSH-, T4- or T3-levels, OMC caused a dose-dependent decrease of serum concentrations of all of these hormones. TRH expression remained unaffected, while in the thyroid, expression of the TSH receptor but not of NIS was stimulated by OMC. TPO activity was unaltered but Dio1 activity was reduced by OMC. Thus, our results demonstrate a non-estrogenic interference of OMC within the rodent HPT axis with inadequate feedback response to impaired thyroid hormone status, indicated by decreased serum thyroid hormone and hepatic Dio1 levels.

  18. Effects of a 5-day treatment with the UV-filter octyl-methoxycinnamate (OMC) on the function of the hypothalamo-pituitary-thyroid function in rats

    International Nuclear Information System (INIS)

    Klammer, Holger; Schlecht, Christiane; Wuttke, Wolfgang; Schmutzler, Cornelia; Gotthardt, Inka; Koehrle, Josef; Jarry, Hubertus

    2007-01-01

    Octyl-methoxycinnamate (OMC) is one of the most frequently used UV-filters in sunscreens to protect the skin against the noxious influence of UV radiation. Recently, OMC was suspected to act as an 'endocrine active chemical' (EAC) with estrogenic actions. While EACs have been investigated thoroughly for interference with reproductive function in mammalians, surprisingly little efforts have been made to investigate an interference of EACs with the hypothalamo-pituitary-thyroid (HPT) axis despite the expression of estrogen receptors in all parts of this axis. Therefore, we conducted an in vivo study with ovariectomised rats treated for 5 days with different doses of OMC or 17β-estradiol (E2) as a control. Determined parameters comprised serum levels of TSH, T4 and T3, hypothalamic TRH mRNA expression, protein-expression of the sodium-iodide-symporter (NIS) and the TSH receptor and the activities of thyroid peroxidase (TPO) in the thyroid and the T3-responsive hepatic type I 5'deiodinase (Dio1) in the liver. While E2 did not affect TSH-, T4- or T3-levels, OMC caused a dose-dependent decrease of serum concentrations of all of these hormones. TRH expression remained unaffected, while in the thyroid, expression of the TSH receptor but not of NIS was stimulated by OMC. TPO activity was unaltered but Dio1 activity was reduced by OMC. Thus, our results demonstrate a non-estrogenic interference of OMC within the rodent HPT axis with inadequate feedback response to impaired thyroid hormone status, indicated by decreased serum thyroid hormone and hepatic Dio1 levels

  19. A flow-through aqueous standard generation system for thin film microextraction investigations of UV filters and biocides partitioning to different environmental compartments.

    Science.gov (United States)

    Ahmadi, Fardin; Sparham, Chris; Pawliszyn, Janusz

    2017-11-01

    In this paper problems associated with preparation of aqueous standard of highly hydrophobic compounds such as partial precipitation, being lost on the surfaces, low solubility in water and limited sample volume for accurate determination of their distribution coefficients are addressed. The following work presents two approaches that utilize blade thin film microextraction (TFME) to investigate partitioning of UV filters and biocides to humic acid (dissolved organic carbon) and sediment. A steady-state concentration of target analytes in water was generated using a flow-through aqueous standard generation (ASG) system. Dialysis membranes, a polytetrafluoroethylene permeation tube, and a frit porous (0.5 μm) coated by epoxy glue were basic elements used for preparation of the ASG system. In the currently presented study, negligible depletion TFME using hydrophilic-lipophilic balance (HLB) and octadecyl silica-based (C18) sorbents was employed towards the attainment of free concentration values of target analytes in the studied matrices. Thin film geometry provided a large volume of extraction phase, which improved the sensitivity of the method towards highly matrix-bound analytes. Extractions were performed in the equilibrium regime so as to prevent matrix effects and with aims to reach maximum method sensitivity for all analytes under study. Partitioning of analytes on dissolved organic carbon (DOC) was investigated in ASG to facilitate large sample volume conditions. Binding percentages and DOC distribution coefficients (Log K DOC ) ranged from 20 to 98% and 3.71-6.72, respectively. Furthermore, sediment-water partition coefficients (K d ), organic-carbon normalized partition coefficients (Log K OC ), and DOC distribution coefficients (Log K DOC ) were investigated in slurry sediment, and ranged from 33 to 2860, 3.31-5.24 and 4.52-5.75 Lkg -1 , respectively. The obtained results demonstrated that investigations utilizing ASG and TFME can yield reliable binding

  20. A Dual-Line Detection Rayleigh Scattering Diagnostic Technique for the Combustion of Hydrocarbon Fuels and Filtered UV Rayleigh Scattering for Gas Velocity Measurements

    Science.gov (United States)

    Otugen, M. Volkan

    1997-01-01

    Non-intrusive techniques for the dynamic measurement of gas flow properties such as density, temperature and velocity, are needed in the research leading to the development of new generation high-speed aircraft. Accurate velocity, temperature and density data obtained in ground testing and in-flight measurements can help understand the flow physics leading to transition and turbulence in supersonic, high-altitude flight. Such non-intrusive measurement techniques can also be used to study combustion processes of hydrocarbon fuels in aircraft engines. Reliable, time and space resolved temperature measurements in various combustor configurations can lead to a better understanding of high temperature chemical reaction dynamics thus leading to improved modeling and better prediction of such flows. In view of this, a research program was initiated at Polytechnic University's Aerodynamics Laboratory with support from NASA Lewis Research Center through grants NAG3-1301 and NAG3-1690. The overall objective of this program has been to develop laser-based, non-contact, space- and time-resolved temperature and velocity measurement techniques. In the initial phase of the program a ND:YAG laser-based dual-line Rayleigh scattering technique was developed and tested for the accurate measurement of gas temperature in the presence of background laser glare. Effort was next directed towards the development of a filtered, spectrally-resolved Rayleigh/Mie scattering technique with the objective of developing an interferometric method for time-frozen velocity measurements in high-speed flows utilizing the uv line of an ND:YAG laser and an appropriate molecular absorption filter. This effort included both a search for an appropriate filter material for the 266 nm laser line and the development and testing of several image processing techniques for the fast processing of Fabry-Perot images for velocity and temperature information. Finally, work was also carried out for the development of

  1. Margin of safety for two UV filters estimated by in vitro permeation studies mimicking consumer habits: Effects of skin shaving and sunscreen reapplication.

    Science.gov (United States)

    Hojerová, Jarmila; Peráčková, Zuzana; Beránková, Martina

    2017-05-01

    Sunscreens are intended to work on the skin. To be both efficient and safe, the lowest possible percutaneous permeation of UV filters should occur. The potential for systemic absorption of Benzophenone-3 (BP3, 10%) and Ethylhexyl Triazone (EHT, 5%) in a silicone-based water-in-oil emulsion was assessed in vitro using a full-thickness porcine-ear skin mimicking in-use conditions. The estimated Systemic Exposure Dose (SED) after the sunscreen application at 1.0 mg/cm 2 for 6 h (i) on the face; (ii) on the whole-body skin, was (i) 136 and 30; (ii) 4200 and 933 μg/kg_bw/d for BP3 and EHT, respectively. Reapplication does not mean the double risk; the SED values were only 1.40-1.37-fold greater. Skin shaving increased BP3 and EHT bioavailability 1.38 and 1.80-fold, respectively. Margin of Safety values were estimated according to guidelines applicable for European Union. For three realistic exposure scenarios, MoS of 48, 34 and 34 for BP3 in the sunscreen applied on the whole-body indicate some concerns regarding the safety for consumers (MoSfilters should be focused on their specific physico-chemical properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Skin absorption studies of octyl-methoxycinnamate loaded poly(D,L-lactide) nanoparticles: estimation of the UV filter distribution and release behaviour in skin layers.

    Science.gov (United States)

    Vettor, M; Bourgeois, S; Fessi, H; Pelletier, J; Perugini, P; Pavanetto, F; Bolzinger, M A

    2010-05-01

    New formulation strategies have to be developed to limit the skin penetration of UV-filter. Nanoparticles (NP) are very suitable for that purpose. In this study, the skin distribution, at different times (1, 2 and 3 h), of octyl-methoxycinnamate (OMC) from loaded PLA-nanoparticles was compared to a classical formulation containing non-encapsulated OMC, using the Franz cell method. The results showed that the OMC penetration was clearly impeded by stratum corneum and that the major part of the OMC-NP was accumulated at the skin surface (> 80%). A significant lower OMC amount was quantified in viable skin with NP compared to the OMC emulgel. To accurately determine the real OMC amount in close contact with viable skin layers two solvents were used to extract OMC from the skin compartments. Acetone (ACET) allowed quantifying both OMC in NP and OMC released from the particles, while isopropylmyristate (IPM), a non-solvent of the NP polymer (PLA), allowed quantifying only OMC released from the particles. Using IPM as an extraction solvent, it appeared that the OMC released from NP, in contact with viable skin, was 3-fold lower than free OMC diffused from the emulgel. Lastly, a sustained release was observed when nanoparticles were used.

  3. Thin layer chromatography-spray mass spectrometry: a method for easy identification of synthesis products and UV filters from TLC aluminum foils.

    Science.gov (United States)

    Himmelsbach, Markus; Waser, Mario; Klampfl, Christian W

    2014-06-01

    A straightforward procedure for direct mass spectrometric (MS) analysis of spots from thin layer chromatography (TLC) plates, without the need of an external ion source, was developed using the aluminum plate backing as spray tip. The spots were cut out shaped as a tip with a 60° angle, mounted in front of the MS orifice, and after addition of a spray solvent spectra were obtained immediately. A high-resolution time-of-flight MS was used since the method is of particular interest for rapid identification or confirmation of spots from TLC plates. The practical benefits of this technique were demonstrated by detection of by-products of organic reactions, by identification of degradation products, and by accurate confirmation of spots when UV filters in sunscreens were analyzed by TLC. Employing the described method TLC spots can be evaluated fast without the need of an external ion source or devices for analyte transfer from TLC to MS, only a basic MS instrument and a high-voltage power supply is required.

  4. Filter-based measurements of UV-vis mass absorption cross sections of organic carbon aerosol from residential biomass combustion: Preliminary findings and sources of uncertainty

    Science.gov (United States)

    Pandey, Apoorva; Pervez, Shamsh; Chakrabarty, Rajan K.

    2016-10-01

    Combustion of solid biomass fuels is a major source of household energy in developing nations. Black (BC) and organic carbon (OC) aerosols are the major PM2.5 (particulate matter with aerodynamic diameter smaller than 2.5 μm) pollutants co-emitted during burning of these fuels. While the optical nature of BC is well characterized, very little is known about the properties of light-absorbing OC (LAOC). Here, we report our preliminary findings on the mass-based optical properties of LAOC emitted from the combustion of four commonly used solid biomass fuels - fuel-wood, agricultural residue, dung-cake, and mixed - in traditional Indian cookstoves. As part of a pilot field study conducted in central India, PM2.5 samples were collected on Teflon filters and analyzed for their absorbance spectra in the 300-900 nm wavelengths at 1 nm resolution using a UV-Visible spectrophotometer equipped with an integrating sphere. The mean mass absorption cross-sections (MAC) of the emitted PM2.5 and OC, at 550 nm, were 0.8 and 0.2 m2 g-1, respectively, each with a factor of ~2.3 uncertainty. The mean absorption Ångström exponent (AǺE) values for PM2.5 were 3±1 between 350 and 550 nm, and 1.2±0.1 between 550 and 880 nm. In the 350-550 nm range, OC had an AǺE of 6.3±1.8. The emitted OC mass, which was on average 25 times of the BC mass, contributed over 50% of the aerosol absorbance at wavelengths smaller than 450 nm. The overall OC contribution to visible solar light (300-900 nm) absorption by the emitted particles was 26-45%. Our results highlight the need to comprehensively and accurately address: (i) the climatic impacts of light absorption by OC from cookstove emissions, and (ii) the uncertainties and biases associated with variability in biomass fuel types and combustion conditions, and filter-based measurement artifacts during determination of MAC values.

  5. UV-induced effects

    NARCIS (Netherlands)

    Liebsch, M.; Spielmann, H.; Pape, W.; Krul, C.; Deguercy, A.; Eskes, C.A.M.

    2005-01-01

    Regulatory requirements: According to the current Notes for Guidance of the Scientific Committee on Cosmetic Products and Non-Food Products (SCCNFP), cosmetic ingredients and mixtures of ingredients absorbing UV light (in particular UV filter chemicals used, for example, to ensure the light

  6. Exposure to phenols, parabens and UV filters: Associations with loss-of-function mutations in the filaggrin gene in men from the general population.

    Science.gov (United States)

    Joensen, Ulla N; Jørgensen, Niels; Thyssen, Jacob P; Petersen, Jørgen Holm; Szecsi, Pal B; Stender, Steen; Andersson, Anne-Maria; Skakkebæk, Niels E; Frederiksen, Hanne

    2017-08-01

    Filaggrin is an epidermal protein that is important for normal skin barrier functions. Up to 10% of Europeans and Asians carry filaggrin gene (FLG) loss-of function mutations that appear to facilitate trans-epidermal penetration of certain chemicals. We previously showed that mutation carriers have higher internal exposure to certain phthalates, compared to controls, and hypothesized that they could have increased trans-epidermal penetration of other chemicals. We investigated exposure to non-persistent chemicals in young Danish men with and without FLG mutations. Concentrations of eight simple phenols, six parabens and nine UV filters were analysed in urine from 65 FLG loss-of-function mutation carriers and 130 non-carriers (controls). Regression analyses, controlling for urinary dilution and confounders, were performed to estimate associations between FLG mutation status and chemical concentrations in urine. FLG mutation carriers had 80% (13-180%) higher urinary concentrations of methyl paraben (MeP) and 91% (13-219%) higher concentrations of n-propyl paraben (n-PrP) than controls. For 13 compounds, levels were higher in FLG mutation carriers, although differences were only statistically significant for MeP and n-PrP. Combined statistical analysis of concentrations of all the 18 compounds that were detectable in >10% of subjects, suggested that concentrations were generally higher in mutation carriers (p=0.03). FLG loss-of-function mutation carriers have a higher internal exposure to some non-persistent chemicals, independently of atopic dermatitis. This may be due to increased trans-epidermal absorption and/or higher exposure, and mutation carriers may constitute a group susceptible to increased absorption of chemicals and topical medication. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Typical worlds

    Science.gov (United States)

    Barrett, Jeffrey A.

    2017-05-01

    Hugh Everett III presented pure wave mechanics, sometimes referred to as the many-worlds interpretation, as a solution to the quantum measurement problem. While pure wave mechanics is an objectively deterministic physical theory with no probabilities, Everett sought to show how the theory might be understood as making the standard quantum statistical predictions as appearances to observers who were themselves described by the theory. We will consider his argument and how it depends on a particular notion of branch typicality. We will also consider responses to Everett and the relationship between typicality and probability. The suggestion will be that pure wave mechanics requires a number of significant auxiliary assumptions in order to make anything like the standard quantum predictions.

  8. Effects of pre- and postnatal exposure to the UV-filter octyl methoxycinnamate (OMC) on the reproductive, auditory and neurological development of rat offspring.

    Science.gov (United States)

    Axelstad, Marta; Boberg, Julie; Hougaard, Karin Sørig; Christiansen, Sofie; Jacobsen, Pernille Rosenskjold; Mandrup, Karen Riiber; Nellemann, Christine; Lund, Søren Peter; Hass, Ulla

    2011-02-01

    Octyl Methoxycinnamate (OMC) is a frequently used UV-filter in sunscreens and other cosmetics. The aim of the present study was to address the potential endocrine disrupting properties of OMC, and to investigate how OMC induced changes in thyroid hormone levels would be related to the neurological development of treated offspring. Groups of 14-18 pregnant Wistar rats were dosed with 0, 500, 750 or 1000 mg OMC/kg bw/day during gestation and lactation. Serum thyroxine (T(4)), testosterone, estradiol and progesterone levels were measured in dams and offspring. Anogenital distance, nipple retention, postnatal growth and timing of sexual maturation were assessed. On postnatal day 16, gene expression in prostate and testes, and weight and histopathology of the thyroid gland, liver, adrenals, prostate, testes, epididymis and ovaries were measured. After weaning, offspring were evaluated in a battery of behavioral and neurophysiological tests, including tests of activity, startle response, cognitive and auditory function. In adult animals, reproductive organ weights and semen quality were investigated. Thyroxine (T(4)) levels showed a very marked decrease during the dosing period in all dosed dams, but were less severely affected in the offspring. On postnatal day 16, high dose male offspring showed reduced relative prostate and testis weights, and a dose-dependent decrease in testosterone levels. In OMC exposed female offspring, motor activity levels were decreased, while low and high dose males showed improved spatial learning abilities. The observed behavioral changes were probably not mediated solely by early T(4) deficiencies, as the observed effects differed from those seen in other studies of developmental hypothyroxinemia. At eight months of age, sperm counts were reduced in all three OMC-dosed groups, and prostate weights were reduced in the highest dose group. Taken together, these results indicate that perinatal OMC-exposure can affect both the reproductive and

  9. Effects of pre- and postnatal exposure to the UV-filter Octyl Methoxycinnamate (OMC) on the reproductive, auditory and neurological development of rat offspring

    International Nuclear Information System (INIS)

    Axelstad, Marta; Boberg, Julie; Hougaard, Karin Sorig; Christiansen, Sofie; Jacobsen, Pernille Rosenskjold; Mandrup, Karen Riiber; Nellemann, Christine; Lund, Soren Peter; Hass, Ulla

    2011-01-01

    Octyl Methoxycinnamate (OMC) is a frequently used UV-filter in sunscreens and other cosmetics. The aim of the present study was to address the potential endocrine disrupting properties of OMC, and to investigate how OMC induced changes in thyroid hormone levels would be related to the neurological development of treated offspring. Groups of 14-18 pregnant Wistar rats were dosed with 0, 500, 750 or 1000 mg OMC/kg bw/day during gestation and lactation. Serum thyroxine (T 4 ), testosterone, estradiol and progesterone levels were measured in dams and offspring. Anogenital distance, nipple retention, postnatal growth and timing of sexual maturation were assessed. On postnatal day 16, gene expression in prostate and testes, and weight and histopathology of the thyroid gland, liver, adrenals, prostate, testes, epididymis and ovaries were measured. After weaning, offspring were evaluated in a battery of behavioral and neurophysiological tests, including tests of activity, startle response, cognitive and auditory function. In adult animals, reproductive organ weights and semen quality were investigated. Thyroxine (T 4 ) levels showed a very marked decrease during the dosing period in all dosed dams, but were less severely affected in the offspring. On postnatal day 16, high dose male offspring showed reduced relative prostate and testis weights, and a dose-dependent decrease in testosterone levels. In OMC exposed female offspring, motor activity levels were decreased, while low and high dose males showed improved spatial learning abilities. The observed behavioral changes were probably not mediated solely by early T 4 deficiencies, as the observed effects differed from those seen in other studies of developmental hypothyroxinemia. At eight months of age, sperm counts were reduced in all three OMC-dosed groups, and prostate weights were reduced in the highest dose group. Taken together, these results indicate that perinatal OMC-exposure can affect both the reproductive and

  10. A rapid, accurate and sensitive method with the new stable isotopic tags based on microwave-assisted dispersive liquid-liquid microextraction and its application to the determination of hydroxyl UV filters in environmental water samples.

    Science.gov (United States)

    Li, Xiu; Chen, Guang; Liu, Jianjun; Liu, Yuxia; Zhao, Xianen; Cao, Ziping; Xia, Lian; Li, Guoliang; Sun, Zhiwei; Zhang, Shijuan; Wang, Hua; You, Jinmao

    2017-05-15

    A rapid, accurate and sensitive method, using the stable isotope labeling (SIL), microwave-assisted dispersive liquid-liquid micro extraction (MADLLME) and the ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), was developed and validated for the determination of hydroxyl UV Filters in environmental water samples. A pair of new isotopic tags D 0 -/D 3 -1-methylindole-3-acetic acid (D 0 -/D 3 -MIAA) is synthesized, with which a simple yet efficient pretreatment MADLLME-SIL is developed. Under the optimized conditions (80℃, 240W, 180s), the sample pretreatment including analyte extraction, pre-concentration and isotope labeling can be finished conveniently in only 9min. D 0 -/D 3 -MIAA labeling improves the chromatographic retention by strengthening the hydrophobicity and enhances the MS response for 3-4 orders of magnitude. Excellent linearity is established by the H/D ratios of 1/10-10/1 with the correlation coefficients >0.9990. The quite low detection limits (0.54-1.79ng/L) are achieved, ensuring the trace detection. This method is successfully applied to a series of environmental water samples. The recoveries (93.2%~103.5%) are significantly improved and the analysis time is largely reduced (UV filters in water samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Effects of the UV-filter 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC) on expression of genes involved in hormonal pathways in fathead minnows (Pimephales promelas) and link to vitellogenin induction and histology

    International Nuclear Information System (INIS)

    Christen, Verena; Zucchi, Sara; Fent, Karl

    2011-01-01

    UV-filters are increasingly used in cosmetics and in the protection of materials against UV-irradiation, and ultimately they reach aquatic systems. The lipophilic UV-filter 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC) belongs to one of the most frequently used UV-filters and accumulates in aquatic animals. Despite its ubiquitous presence in water and biota, very little is known about its potential hormonal effects on aquatic organisms. In our study, we evaluated the effects of measured water concentration of 5.4, 37.5, 244.5 and 394 μg/L EHMC on the expression of genes involved in hormonal pathways in the liver, testis and brain of male and female fathead minnows (Pimephales promelas). We compare the transcription profile with the plasma vitellogenin (VTG) content, secondary sex characteristics, and gonad histology. Transcripts of the androgen receptor (ar) were significantly down-regulated in the liver of females at 37.5, 244.5 μg/L and 394 μg/L EHMC. Additionally, the 3β-hydroxysteroid dehydrogenase (3β-HSD) transcript was significantly decreased in the liver of males at 37.5, 244.5 and 394 μg/L EHMC, and at 244.5 and 394 μg/L EHMC in females. The expressional changes were tissue-specific in most cases, being most significant in the liver. Vitellogenin plasma concentration was significantly increased at 244.5 μg/L EHMC in males. EHMC induced significant histological changes in testes and ovaries at 394 μg/L. Testes displayed a decrease in spermatocytes, and ovaries a decrease in previtellogenic oocytes. The induction of VTG plasma concentration and the histological changes in gonads suggest an estrogenic and/or antiandrogenic activity of EHMC. On the other hand, the gene expression profile shows an antiestrogenic (e.g.: down-regulation of esr1) activity of EHMC. In conclusion, our data demonstrate that EHMC displays low but multiple hormonal activities in fish.

  12. uvsI mutants defective in UV mutagenesis define a fourth epistatic group of uvs genes in Aspergillus.

    Science.gov (United States)

    Chae, S K; Kafer, E

    1993-01-01

    Three UV-sensitive mutations of A. nidulans, uvsI, uvsJ and uvsA, were tested for epistatic relationships with members of the previously established groups, here called the "UvsF", "UvsC", and "UvsB" groups. uvsI mutants are defective for spontaneous and induced reversion of certain point mutations and differ also for other properties from previously analyzed uvs types. They are very sensitive to the killing effects of UV-light and 4-NQO (4-nitro-quinoline-N-oxide) but not to MMS (methylmethane sulfonate). When double- and single-mutant uvs strains were compared for sensitivity to these three agents, synergistic or additive effects were found for uvsI with all members of the three groups. The uvsI gene may therefore represent a fourth epistatic group, possibly involved in mutagenic repair. On the other hand, uvsJ was clearly epistatic with members of the UvsF group and fitted well into this group also by phenotype. The uvsA gene was tentatively assigned to the UvsC group. uvsA showed epistatic interactions with uvsC in all tests, and like UvsC-group mutants is UV-sensitive mainly in dividing cells. However, the uvsA mutation does not cause the defects in recombination and UV mutagenesis typical for this group.

  13. Simultaneous determination of the UV-filters benzyl salicylate, phenyl salicylate, octyl salicylate, homosalate, 3-(4-methylbenzylidene) camphor and 3-benzylidene camphor in human placental tissue by LC-MS/MS. Assessment of their in vitro endocrine activity.

    Science.gov (United States)

    Jiménez-Díaz, I; Molina-Molina, J M; Zafra-Gómez, A; Ballesteros, O; Navalón, A; Real, M; Sáenz, J M; Fernández, M F; Olea, N

    2013-10-01

    UV-filters are widely used in many personal care products and cosmetics. Recent studies indicate that some organic UV-filters can accumulate in biota and act as endocrine disruptors, but there are few studies on the occurrence and fate of these compounds in humans. In the present work, a new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to assess the presence of six UV-filters in current use (benzyl salicylate, phenyl salicylate, octyl salicylate, homosalate, 3-(4-methylbenzylidene) camphor, and 3-benzylidene camphor) in human placental tissue is proposed. The method involves the extraction of the analytes from the samples using ethyl acetate, followed by a clean-up step using centrifugation prior to their quantification by LC-MS/MS using an atmospheric pressure chemical ionization (APCI) interface. Bisphenol A-d16 was used as surrogate for the determination of benzyl salicylate, phenyl salicylate, octyl salicylate and homosalate in negative mode and benzophenone-d10, was used as surrogate for the determination of 3-(4-methylbenzylidene) camphor and 3-benzylidene camphor in positive mode. The found limits of detection ranged from 0.4 to 0.6ngg(-1) and the limits of quantification ranged from 1.3 to 2.0ngg(-1), while variability was under 13.7%. Recovery rates for spiked samples ranged from 97% to 104%. Moreover, the interactions of these compounds with the human estrogen receptor alpha (hERα) and androgen receptor (hAR), using two in vitro bioassays based on reporter gene expression and cell proliferation assessment, were also investigated. All tested compounds, except benzyl salicylate and octyl salicylate, showed estrogenic activity in the E-Screen bioassay whereas only homosalate and 3-(4-methylbenzylidene) camphor were potent hAR antagonists. Although free salicylate derivatives and free camphor derivatives were not detected in the human placenta samples analyzed, the observed estrogenic and anti-androgenic activities of some of these

  14. Ambient UV-B radiation reduces PSII performance and net photosynthesis in high Arctic Salix arctica

    DEFF Research Database (Denmark)

    Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

    2011-01-01

    Ambient ultraviolet-B (UV-B) radiation potentially impacts the photosynthetic performance of high Arctic plants. We conducted an UV-B exclusion experiment in a dwarf shrub heath in NE Greenland (74°N), with open control, filter control, UV-B filtering and UV-AB filtering, all in combination...

  15. Deep Ultraviolet Macroporous Silicon Filters, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal describes a novel method to make deep and far UV optical filters from macroporous silicon. This type of filter consists of an array of...

  16. Widespread occurrence of benzophenone-type UV light filters in personal care products from China and the United States: an assessment of human exposure.

    Science.gov (United States)

    Liao, Chunyang; Kannan, Kurunthachalam

    2014-04-01

    Benzophenone-3 (BP-3) is a sunscreen agent used in a variety of personal care products (PCPs) for the protection of human skin and hair from damage by ultraviolet (UV) radiation. Concerns have been raised over exposure of humans to BP-3, owing to the estrogenic potential of this compound. Nevertheless, the levels and profiles of BP-3 in PCPs and sources of exposure of humans to this estrogenic compound are not well-known. In this study, concentrations of BP-3 were determined in seven categories of 231 PCPs collected from several cities in China (n = 117) and the United States (U.S.) (n = 114), using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). BP-3 was found in the majority (81%) of the samples analyzed, at concentrations as high as 0.148%. The highest BP-3 concentrations (geometric mean [GM]: 548; median: 530 ng/g) were found in skin lotions (including sunscreen lotions), followed by makeup products (284; 221 ng/g). PCPs collected from the U.S. contained higher concentrations of BP-3 than those collected from China. On the basis of the concentrations measured and daily usage rates of PCPs, we estimated the daily intake of BP-3 through dermal absorption from the use of PCPs. The GM and 95th percentile exposure doses to BP-3 were 0.978 and 25.5 μg/day, respectively, for adult women in China, which were 2 orders of magnitude lower than those found for adult women in the U.S. (24.4 and 5160 μg/day). Skin lotions and face creams contributed to the preponderance of daily BP-3 exposures (>80%).

  17. Metabolism of UV-filter benzophenone-3 by rat and human liver microsomes and its effect on endocrine-disrupting activity

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yoko, E-mail: y-watanabe@nichiyaku.ac.jp [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan); Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Kojima, Hiroyuki; Takeuchi, Shinji [Hokkaido Institute of Public Health, Kita-19, Nishi-12, Kita-ku, Sapporo 060-0819 (Japan); Uramaru, Naoto [Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Sanoh, Seigo [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan); Sugihara, Kazumi [Faculty of Pharmaceutical Science, Hiroshima International University, Koshingai 5-1-1, Kure, Hiroshima 737-0112 (Japan); Kitamura, Shigeyuki [Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Ohta, Shigeru [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan)

    2015-01-15

    Benzophenone-3 (2-hydroxy-4-methoxybenzophenone; BP-3) is widely used as sunscreen for protection of human skin and hair from damage by ultraviolet (UV) radiation. In this study, we examined the metabolism of BP-3 by rat and human liver microsomes, and the estrogenic and anti-androgenic activities of the metabolites. When BP-3 was incubated with rat liver microsomes in the presence of NADPH, 2,4,5-trihydroxybenzophenone (2,4,5-triOH BP) and 3-hydroxylated BP-3 (3-OH BP-3) were newly identified as metabolites, together with previously detected metabolites 5-hydroxylated BP-3 (5-OH BP-3), a 4-desmethylated metabolite (2,4-diOH BP) and 2,3,4-trihydroxybenzophenone (2,3,4-triOH BP). In studies with recombinant rat cytochrome P450, 3-OH BP-3 and 2,4,5-triOH BP were mainly formed by CYP1A1. BP-3 was also metabolized by human liver microsomes and CYP isoforms. In estrogen reporter (ER) assays using estrogen-responsive CHO cells, 2,4-diOH BP exhibited stronger estrogenic activity, 2,3,4-triOH BP exhibited similar activity, and 5-OH BP-3, 2,4,5-triOH BP and 3-OH BP-3 showed lower activity as compared to BP-3. Structural requirements for activity were investigated in a series of 14 BP-3 derivatives. When BP-3 was incubated with liver microsomes from untreated rats or phenobarbital-, 3-methylcholanthrene-, or acetone-treated rats in the presence of NADPH, estrogenic activity was increased. However, liver microsomes from dexamethasone-treated rats showed decreased estrogenic activity due to formation of inactive 5-OH BP-3 and reduced formation of active 2,4-diOH BP. Anti-androgenic activity of BP-3 was decreased after incubation with liver microsomes. - Highlights: • Metabolic modification of the endocrine-disrupting activity of BP-3 was examined. • 2,4,5-TriOH BP and 3-OH BP-3 were identified as new BP-3 metabolites. • 2,4-DiOH BP and 2,3,4-triOH BP exhibited high or similar estrogenic activities. • Estrogenic activity of BP-3 was enhanced by incubation with rat liver

  18. Benzophenone-type UV filters in urine and blood from children, adults, and pregnant women in China: partitioning between blood and urine as well as maternal and fetal cord blood.

    Science.gov (United States)

    Zhang, Tao; Sun, Hongwen; Qin, Xiaolei; Wu, Qian; Zhang, Yanfeng; Ma, Jing; Kannan, Kurunthachalam

    2013-09-01

    Limited information exists on the exposure of benzophenone (BP)-type UV filters (i.e., sunscreen compounds) in children, adults, and pregnant women in China. In this study, we determined the concentrations of five BP derivatives, BP-1, BP-2, BP-3, BP-8, and 4OH-BP in urine (n=101) as well as paired specimens of blood and urine (n=24 pairs) collected from adults; in matched maternal and fetal cord blood (n=20 pairs) collected from pregnant women; and in blood collected from children (n=10). 4OH-BP, BP-1, and BP-3 were found in 61%, 57%, and 25%, respectively, of the urine samples analyzed. 4OH-BP was found in all blood samples; BP-3 was found more frequently in the blood of adults (83%), followed, in decreasing order, by pregnant women (35%) and children (30%). Among all adults, urinary BP-3 concentrations were significantly (pblood and urine was 0.21 in adults, which was significantly lower than that for 4OH-BP (0.36). The concentration ratio of BPs between cord blood and maternal blood was higher for 4OH-BP (0.61) than that for BP-3 (0.48), which suggested greater trans-placental transfer potential of 4OH-BP. This is the first study to document the occurrence of BPs in paired urine and blood, and in matched maternal and fetal cord blood. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Coupled exposure to ingredients of cosmetic products: III. Ultraviolet filters.

    Science.gov (United States)

    Uter, Wolfgang; Gonçalo, Margarida; Yazar, Kerem; Kratz, Eva-Maria; Mildau, Gerd; Lidén, Carola

    2014-09-01

    The use of cosmetics exposes consumers to mixtures of ingredients, many of which are potential allergens. Ultraviolet (UV) filters are used not just in sunscreens, but also in other products. Many UV filters are known contact allergens and photoallergens. To examine the pattern of co-exposure to UV filters in cosmetics. A survey of products marketed in Germany, conducted in 2006-2009 by the Chemical and Veterinary Investigation Office in Karlsruhe, identified 4447 products (of all 5667 cosmetic products examined) (i) that were categorizable according to Annex I to the Cosmetics Directive, and (ii) with information on the presence of UV filters or zinc oxide. The occurrence and co-occurrence of UV filters were analysed and presented in tabular and graphical format. UV filters or zinc oxide were present in 22.5% of all 4447 products, ranging from almost 100% in sunscreens to a few per cent in, for example, some hair products; they were absent in two product categories. Frequently, several different UV filters were included in one product, for example in sunscreens (median 4) and in perfumes (median 3). The overall most frequent UV filters were butyl methoxydibenzoylmethane and titanium dioxide, combined mostly with octocrylene in sunscreens and with ethylhexyl methoxycinnamate in creams. The frequent co-occurrence of UV filters in cosmetic products possibly facilitates sensitization, and may explain why patients often react to chemically unrelated UV filters. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. UV Signature Mutations †

    Science.gov (United States)

    2014-01-01

    Sequencing complete tumor genomes and exomes has sparked the cancer field's interest in mutation signatures for identifying the tumor's carcinogen. This review and meta-analysis discusses signatures and their proper use. We first distinguish between a mutagen's canonical mutations – deviations from a random distribution of base changes to create a pattern typical of that mutagen – and the subset of signature mutations, which are unique to that mutagen and permit inference backward from mutations to mutagen. To verify UV signature mutations, we assembled literature datasets on cells exposed to UVC, UVB, UVA, or solar simulator light (SSL) and tested canonical UV mutation features as criteria for clustering datasets. A confirmed UV signature was: ≥60% of mutations are C→T at a dipyrimidine site, with ≥5% CC→TT. Other canonical features such as a bias for mutations on the non-transcribed strand or at the 3' pyrimidine had limited application. The most robust classifier combined these features with criteria for the rarity of non-UV canonical mutations. In addition, several signatures proposed for specific UV wavelengths were limited to specific genes or species; non-signature mutations induced by UV may cause melanoma BRAF mutations; and the mutagen for sunlight-related skin neoplasms may vary between continents. PMID:25354245

  1. Lichenic extracts and metabolites as UV filters.

    Science.gov (United States)

    Lohézic-Le Dévéhat, Françoise; Legouin, Béatrice; Couteau, Céline; Boustie, Joël; Coiffard, Laurence

    2013-03-05

    Three lichen extracts and ten lichenic compounds have been screened for their photoprotective activities. The determination of their Sun Protection Factor (SPF) and Protection Factor-UVA (PF-UVA) values was done in vitro. Among them, a Lasallia pustulata extract and gyrophoric acid exhibited SPF values over 5, which is better than Homosalate (SPF≈4). Their photoprotective properties are only slightly modified after a 2-hours period of irradiation. Salazinic acid and L. pustulata presented characteristics of a UVA booster like the butyl-methoxydibenzoylmethane (Avobenzone) (PF-UVA≈2 vs. 2.8 for Avobenzone). Salazinic acid was a better anion superoxide scavenger than ascorbic acid and none of them exhibited a photosensitizing cytotoxicity by exposing them on HaCaT cells to UVA radiations (photo-irritancy factor PIF<5). Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Nanoscale freestanding gratings for ultraviolet blocking filters

    Energy Technology Data Exchange (ETDEWEB)

    van Beek, J.T.; Fleming, R.C.; Hindle, P.S.; Prentiss, J.D.; Schattenburg, M.L. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Ritzau, S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1998-11-01

    Ultraviolet (UV) blocking filters are needed for atomic flux imaging in environments where high levels of ultraviolet radiation are present. Freestanding gratings are a promising candidate for UV filtering. They have a high aspect ratio ({approximately}13), narrow ({approximately}40 nm) slots, and effectively block UV radiation. The grating fabrication process makes use of several etching, electroplating, and lithographic steps and includes an optional step to plug pinholes induced by particles during processing. Gratings were successfully manufactured and tested. Measured UV transmissions of {approximately}10{sup {minus}5} and particle transmissions of {approximately}10{percent} are in agreement with theoretical predictions. {copyright} {ital 1998 American Vacuum Society.}

  3. Filter arrays

    Energy Technology Data Exchange (ETDEWEB)

    Page, Ralph H.; Doty, Patrick F.

    2017-08-01

    The various technologies presented herein relate to a tiled filter array that can be used in connection with performance of spatial sampling of optical signals. The filter array comprises filter tiles, wherein a first plurality of filter tiles are formed from a first material, the first material being configured such that only photons having wavelengths in a first wavelength band pass therethrough. A second plurality of filter tiles is formed from a second material, the second material being configured such that only photons having wavelengths in a second wavelength band pass therethrough. The first plurality of filter tiles and the second plurality of filter tiles can be interspersed to form the filter array comprising an alternating arrangement of first filter tiles and second filter tiles.

  4. Benzophenone-type UV filters in urine and blood from children, adults, and pregnant women in China: Partitioning between blood and urine as well as maternal and fetal cord blood

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Tao; Sun, Hongwen; Qin, Xiaolei [College of Environmental Sciences and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300071 (China); Wu, Qian [Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States); Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Albany, NY 12201 (United States); Zhang, Yanfeng [College of Environmental Sciences and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300071 (China); Ma, Jing [Applied Radiation Institute, School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, P.O. Box 144, Shanghai 200444 (China); Kannan, Kurunthachalam, E-mail: kkannan@wadsworth.org [Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States); Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Albany, NY 12201 (United States); International Joint Research Center for Persistent Toxic Substances, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China)

    2013-09-01

    Limited information exists on the exposure of benzophenone (BP)-type UV filters (i.e., sunscreen compounds) in children, adults, and pregnant women in China. In this study, we determined the concentrations of five BP derivatives, BP-1, BP-2, BP-3, BP-8, and 4OH-BP in urine (n = 101) as well as paired specimens of blood and urine (n = 24 pairs) collected from adults; in matched maternal and fetal cord blood (n = 20 pairs) collected from pregnant women; and in blood collected from children (n = 10). 4OH-BP, BP-1, and BP-3 were found in 61%, 57%, and 25%, respectively, of the urine samples analyzed. 4OH-BP was found in all blood samples; BP-3 was found more frequently in the blood of adults (83%), followed, in decreasing order, by pregnant women (35%) and children (30%). Among all adults, urinary BP-3 concentrations were significantly (p < 0.001) positively correlated with urinary BP-1 concentrations. Nevertheless, no significant correlations were found between urinary concentrations of BP-3 (or BP-1) and 4OH-BP. Our results suggest that human exposure to BP-3 and BP-1 is related, whereas 4OH-BP originates from a discrete source. Females had higher urinary concentrations of BP-3, BP-1 and 4OH-BP than males. The distribution profiles of BP-1 and its parent compound (i.e., BP-3) in urine decreased with increasing age of donors (p < 0.05). The ratio of concentrations of BP-3 between blood and urine was 0.21 in adults, which was significantly lower than that for 4OH-BP (0.36). The concentration ratio of BPs between cord blood and maternal blood was higher for 4OH-BP (0.61) than that for BP-3 (0.48), which suggested greater trans-placental transfer potential of 4OH-BP. This is the first study to document the occurrence of BPs in paired urine and blood, and in matched maternal and fetal cord blood. Highlights: • Benzophenone (BP) concentrations are determined in paired blood and urine for the first time. • BP-3 and 4OH-BP partition preferentially into urine. • Cord to

  5. Benzophenone-type UV filters in urine and blood from children, adults, and pregnant women in China: Partitioning between blood and urine as well as maternal and fetal cord blood

    International Nuclear Information System (INIS)

    Zhang, Tao; Sun, Hongwen; Qin, Xiaolei; Wu, Qian; Zhang, Yanfeng; Ma, Jing; Kannan, Kurunthachalam

    2013-01-01

    Limited information exists on the exposure of benzophenone (BP)-type UV filters (i.e., sunscreen compounds) in children, adults, and pregnant women in China. In this study, we determined the concentrations of five BP derivatives, BP-1, BP-2, BP-3, BP-8, and 4OH-BP in urine (n = 101) as well as paired specimens of blood and urine (n = 24 pairs) collected from adults; in matched maternal and fetal cord blood (n = 20 pairs) collected from pregnant women; and in blood collected from children (n = 10). 4OH-BP, BP-1, and BP-3 were found in 61%, 57%, and 25%, respectively, of the urine samples analyzed. 4OH-BP was found in all blood samples; BP-3 was found more frequently in the blood of adults (83%), followed, in decreasing order, by pregnant women (35%) and children (30%). Among all adults, urinary BP-3 concentrations were significantly (p < 0.001) positively correlated with urinary BP-1 concentrations. Nevertheless, no significant correlations were found between urinary concentrations of BP-3 (or BP-1) and 4OH-BP. Our results suggest that human exposure to BP-3 and BP-1 is related, whereas 4OH-BP originates from a discrete source. Females had higher urinary concentrations of BP-3, BP-1 and 4OH-BP than males. The distribution profiles of BP-1 and its parent compound (i.e., BP-3) in urine decreased with increasing age of donors (p < 0.05). The ratio of concentrations of BP-3 between blood and urine was 0.21 in adults, which was significantly lower than that for 4OH-BP (0.36). The concentration ratio of BPs between cord blood and maternal blood was higher for 4OH-BP (0.61) than that for BP-3 (0.48), which suggested greater trans-placental transfer potential of 4OH-BP. This is the first study to document the occurrence of BPs in paired urine and blood, and in matched maternal and fetal cord blood. Highlights: • Benzophenone (BP) concentrations are determined in paired blood and urine for the first time. • BP-3 and 4OH-BP partition preferentially into urine. • Cord to

  6. Generic Kalman Filter Software

    Science.gov (United States)

    Lisano, Michael E., II; Crues, Edwin Z.

    2005-01-01

    The Generic Kalman Filter (GKF) software provides a standard basis for the development of application-specific Kalman-filter programs. Historically, Kalman filters have been implemented by customized programs that must be written, coded, and debugged anew for each unique application, then tested and tuned with simulated or actual measurement data. Total development times for typical Kalman-filter application programs have ranged from months to weeks. The GKF software can simplify the development process and reduce the development time by eliminating the need to re-create the fundamental implementation of the Kalman filter for each new application. The GKF software is written in the ANSI C programming language. It contains a generic Kalman-filter-development directory that, in turn, contains a code for a generic Kalman filter function; more specifically, it contains a generically designed and generically coded implementation of linear, linearized, and extended Kalman filtering algorithms, including algorithms for state- and covariance-update and -propagation functions. The mathematical theory that underlies the algorithms is well known and has been reported extensively in the open technical literature. Also contained in the directory are a header file that defines generic Kalman-filter data structures and prototype functions and template versions of application-specific subfunction and calling navigation/estimation routine code and headers. Once the user has provided a calling routine and the required application-specific subfunctions, the application-specific Kalman-filter software can be compiled and executed immediately. During execution, the generic Kalman-filter function is called from a higher-level navigation or estimation routine that preprocesses measurement data and post-processes output data. The generic Kalman-filter function uses the aforementioned data structures and five implementation- specific subfunctions, which have been developed by the user on

  7. Ozone layer - climate change interactions. Influence on UV levels and UV related effects

    NARCIS (Netherlands)

    Kelfkens G; Bregman A; de Gruijl FR; van der Leun JC; Piquet A; van Oijen T; Gieskes WWC; van Loveren H; Velders GJM; Martens P; Slaper H; NOP; LPI; LLO

    2002-01-01

    Ozone in the atmosphere serves as a partially protective filter against the most harmful part of the solar UV-spectrum. Decreases in ozone lead to increases in ambient UV with a wide variety of adverse effects on human health, aquatic and terrestrial ecosystems and food chains. Human health

  8. Applying polynomial filtering to mass preconditioned Hybrid Monte Carlo

    Science.gov (United States)

    Haar, Taylor; Kamleh, Waseem; Zanotti, James; Nakamura, Yoshifumi

    2017-06-01

    The use of mass preconditioning or Hasenbusch filtering in modern Hybrid Monte Carlo simulations is common. At light quark masses, multiple filters (three or more) are typically used to reduce the cost of generating dynamical gauge fields; however, the task of tuning a large number of Hasenbusch mass terms is non-trivial. The use of short polynomial approximations to the inverse has been shown to provide an effective UV filter for HMC simulations. In this work we investigate the application of polynomial filtering to the mass preconditioned Hybrid Monte Carlo algorithm as a means of introducing many time scales into the molecular dynamics integration with a simplified parameter tuning process. A generalized multi-scale integration scheme that permits arbitrary step-sizes and can be applied to Omelyan-style integrators is also introduced. We find that polynomial-filtered mass-preconditioning (PF-MP) performs as well as or better than standard mass preconditioning, with significantly less fine tuning required.

  9. Germicidal Efficacy and Mammalian Skin Safety of 222-nm UV Light

    Science.gov (United States)

    Buonanno, Manuela; Ponnaiya, Brian; Welch, David; Stanislauskas, Milda; Randers-Pehrson, Gerhard; Smilenov, Lubomir; Lowy, Franklin D.; Owens, David M.; Brenner, David J.

    2017-01-01

    We have previously shown that 207-nm ultraviolet (UV) light has similar antimicrobial properties as typical germicidal UV light (254 nm), but without inducing mammalian skin damage. The biophysical rationale is based on the limited penetration distance of 207-nm light in biological samples (e.g. stratum corneum) compared with that of 254-nm light. Here we extended our previous studies to 222-nm light and tested the hypothesis that there exists a narrow wavelength window in the far-UVC region, from around 200–222 nm, which is significantly harmful to bacteria, but without damaging cells in tissues. We used a krypton-chlorine (Kr-Cl) excimer lamp that produces 222-nm UV light with a bandpass filter to remove the lower- and higher-wavelength components. Relative to respective controls, we measured: 1. in vitro killing of methicillin-resistant Staphylococcus aureus (MRSA) as a function of UV fluence; 2. yields of the main UV-associated premutagenic DNA lesions (cyclobutane pyrimidine dimers and 6-4 photoproducts) in a 3D human skin tissue model in vitro; 3. eight cellular and molecular skin damage endpoints in exposed hairless mice in vivo. Comparisons were made with results from a conventional 254-nm UV germicidal lamp used as positive control. We found that 222-nm light kills MRSA efficiently but, unlike conventional germicidal UV lamps (254 nm), it produces almost no premutagenic UV-associated DNA lesions in a 3D human skin model and it is not cytotoxic to exposed mammalian skin. As predicted by biophysical considerations and in agreement with our previous findings, far-UVC light in the range of 200–222 nm kills bacteria efficiently regardless of their drug-resistant proficiency, but without the skin damaging effects associated with conventional germicidal UV exposure. PMID:28225654

  10. Germicidal Efficacy and Mammalian Skin Safety of 222-nm UV Light.

    Science.gov (United States)

    Buonanno, Manuela; Ponnaiya, Brian; Welch, David; Stanislauskas, Milda; Randers-Pehrson, Gerhard; Smilenov, Lubomir; Lowy, Franklin D; Owens, David M; Brenner, David J

    2017-04-01

    We have previously shown that 207-nm ultraviolet (UV) light has similar antimicrobial properties as typical germicidal UV light (254 nm), but without inducing mammalian skin damage. The biophysical rationale is based on the limited penetration distance of 207-nm light in biological samples (e.g. stratum corneum) compared with that of 254-nm light. Here we extended our previous studies to 222-nm light and tested the hypothesis that there exists a narrow wavelength window in the far-UVC region, from around 200-222 nm, which is significantly harmful to bacteria, but without damaging cells in tissues. We used a krypton-chlorine (Kr-Cl) excimer lamp that produces 222-nm UV light with a bandpass filter to remove the lower- and higher-wavelength components. Relative to respective controls, we measured: 1. in vitro killing of methicillin-resistant Staphylococcus aureus (MRSA) as a function of UV fluence; 2. yields of the main UV-associated premutagenic DNA lesions (cyclobutane pyrimidine dimers and 6-4 photoproducts) in a 3D human skin tissue model in vitro; 3. eight cellular and molecular skin damage endpoints in exposed hairless mice in vivo. Comparisons were made with results from a conventional 254-nm UV germicidal lamp used as positive control. We found that 222-nm light kills MRSA efficiently but, unlike conventional germicidal UV lamps (254 nm), it produces almost no premutagenic UV-associated DNA lesions in a 3D human skin model and it is not cytotoxic to exposed mammalian skin. As predicted by biophysical considerations and in agreement with our previous findings, far-UVC light in the range of 200-222 nm kills bacteria efficiently regardless of their drug-resistant proficiency, but without the skin damaging effects associated with conventional germicidal UV exposure.

  11. The effect of inorganic precursors on disinfection byproduct formation during UV-chlorine/chloramine drinking water treatment.

    Science.gov (United States)

    Lyon, Bonnie A; Dotson, Aaron D; Linden, Karl G; Weinberg, Howard S

    2012-10-01

    Ultraviolet (UV) disinfection is being increasingly used in drinking water treatment. It is important to understand how its application to different types of water may influence finished water quality, particularly as anthropogenic activity continues to impact the quality of source waters. The objective of this study was to evaluate the effect of inorganic precursors on the formation of regulated and unregulated disinfection byproducts (DBPs) during UV irradiation of surface waters when combined with chlorination or chloramination. Samples were collected from three drinking water utilities supplied by source waters with varying organic and inorganic precursor content. The filtered samples were treated in the laboratory with a range of UV doses delivered from low pressure (LP, UV output at 253.7 nm) and medium pressure (MP, polychromatic UV output 200-400 nm) mercury lamps followed by chlorination or chloramination, in the presence and absence of additional bromide and nitrate. The regulated trihalomethanes and haloacetic acids were not affected by UV pretreatment at disinfection doses (40-186 mJ/cm²). With higher doses (1000 mJ/cm²), trihalomethane formation was increased 30-40%. While most effects on DBPs were only observed with doses much higher than typically used for UV disinfection, there were some effects on unregulated DBPs at lower doses. In nitrate-spiked samples (1-10 mg N/L), chloropicrin formation doubled and increased three- to six-fold with 40 mJ/cm² MP UV followed by chloramination and chlorination, respectively. Bromopicrin formation was increased in samples containing bromide (0.5-1 mg/L) and nitrate (1-10 mg N/L) when pretreated with LP or MP UV (30-60% with 40 mJ/cm² LP UV and four- to ten-fold increase with 40 mJ/cm² MP UV, after subsequent chlorination). The formation of cyanogen chloride doubled and increased three-fold with MP UV doses of 186 and 1000 mJ/cm², respectively, when followed by chloramination in nitrate-spiked samples but

  12. Is our Universe typical?

    International Nuclear Information System (INIS)

    Gurzadyan, V.G.

    1988-01-01

    The problem of typicalness of the Universe - as a dynamical system possessing both regular and chaotic regions of positive measure of phase space, is raised and discussed. Two dynamical systems are considered: 1) The observed Universe as a hierarchy of systems of N graviting bodies; 2) (3+1)-manifold with matter evolving to Wheeler-DeWitt equation in superspace with Hawking boundary condition of compact metrics. It is shown that the observed Universe is typical. There is no unambiguous answer for the second system yet. If it is typical too then the same present state of the Universe could have been originated from an infinite number of different initial conditions the restoration of which is practically impossible at present. 35 refs.; 2 refs

  13. Wien filter

    NARCIS (Netherlands)

    Mook, H.W.

    1999-01-01

    The invention relates to a Wien filter provided with electrodes for generating an electric field, and magnetic poles for generating a magnetic field, said electrodes and magnetic poles being positioned around and having a finite length along a filter axis, and being positioned around the filter axis

  14. Rectifier Filters

    Directory of Open Access Journals (Sweden)

    Y. A. Bladyko

    2010-01-01

    Full Text Available The paper contains definition of a smoothing factor which is suitable for any rectifier filter. The formulae of complex smoothing factors have been developed for simple and complex passive filters. The paper shows conditions for application of calculation formulae and filters

  15. FILTER TREATMENT

    Science.gov (United States)

    Sutton, J.B.; Torrey, J.V.P.

    1958-08-26

    A process is described for reconditioning fused alumina filters which have become clogged by the accretion of bismuth phosphate in the filter pores, The method consists in contacting such filters with faming sulfuric acid, and maintaining such contact for a substantial period of time.

  16. Typical Complexity Numbers

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Typical Complexity Numbers. Say. 1000 tones,; 100 Users,; Transmission every 10 msec. Full Crosstalk cancellation would require. Full cancellation requires a matrix multiplication of order 100*100 for all the tones. 1000*100*100*100 operations every second for the ...

  17. Ecological responses to UV radiation: interactions between the biological effects of UV on plants and on associated organisms.

    Science.gov (United States)

    Paul, Nigel D; Moore, Jason P; McPherson, Martin; Lambourne, Cathryn; Croft, Patricia; Heaton, Joanna C; Wargent, Jason J

    2012-08-01

    Solar ultraviolet (UV)-B radiation (280-315 nm) has a wide range of effects on terrestrial ecosystems, yet our understanding of how UV-B influences the complex interactions of plants with pest, pathogen and related microorganisms remains limited. Here, we report the results of a series of experiments in Lactuca sativa which aimed to characterize not only key plant responses to UV radiation in a field environment but also consequential effects for plant interactions with a sap-feeding insect, two model plant pathogens and phylloplane microorganism populations. Three spectrally modifying filters with contrasting UV transmissions were used to filter ambient sunlight, and when compared with our UV-inclusive filter, L. sativa plants grown in a zero UV-B environment showed significantly increased shoot fresh weight, reduced foliar pigment concentrations and suppressed population growth of green peach aphid (Myzus persicae). Plants grown under a filter which allowed partial transmission of UV-A radiation and negligible UV-B transmission showed increased density of leaf surface phylloplane microbes compared with the UV-inclusive treatment. Effects of UV treatment on the severity of two plant pathogens, Bremia lactucae and Botrytis cinerea, were complex as both the UV-inclusive and zero UV-B filters reduced the severity of pathogen persistence. These results are discussed with reference to known spectral responses of plants, insects and microorganisms, and contrasted with established fundamental responses of plants and other organisms to solar UV radiation, with particular emphasis on the need for future integration between different experimental approaches when investigating the effects of solar UV radiation. Copyright © Physiologia Plantarum 2011.

  18. Filter unit

    International Nuclear Information System (INIS)

    Shiba, Kazuo; Nagao, Koji; Akiyama, Toshio; Tanaka, Fumikazu; Osumi, Akira; Hirao, Yasuhiro.

    1997-01-01

    The filter unit is used by attaching to a dustproof mask, and used in a radiation controlled area such as in a nuclear power plant. The filter unit comprises sheet-like front and back filtering members disposed vertically in parallel, a spacer for keeping the filtering members to a predetermined distance and front and back covering members for covering the two filtering members respectively. An electrostatic filter prepared by applying resin-fabrication to a base sheet comprising 100% by weight of organic fibers as fiber components, for example, wool felt, synthetic fiber non-woven fabric, wool and synthetic fiber blend non-woven fabric and then electrifying the resin is used for the filtering members. Then, residue of ashes can be eliminated substantially or completely after burning them. (I.N.)

  19. Influence of uvA on the erythematogenic and therapeutic effects of uvB irradiation in psoriasis; photoaugmentation effects

    International Nuclear Information System (INIS)

    Boer, J.; Schothorst, A.A.; Suurmond, D.

    1981-01-01

    The effect of repeated exposure to an additive dose of long ultraviolet (uvA) radiation on the erythemogenic and therapeutic effects of middle ultraviolet (uvB) irradiation was investigated in 8 patients with psoriasis. The surface of the backs of these patients was divided into 2 parts, 1 of which received only uvB irradiation 4 times a week and the other uvA + uvB. uvB was provided by Philips TL-12 lamps and uvA by glass-filtered Philips TL-09 lamps. uvA was held constantly at 10 J/cm2, whereas uvB alone were evaluated by 4 tests during the treatment to determine the minimal erythema dose (MED). Test I (at the start of the therapy) showed a photoaugmentative effect which was no longer apparent in Test III (third week). Test III showed a reversal of the ratios of the MEDs of the sites irradiated with the uvA + uvB and uvB (MED A + B/MED B). This is ascribed to the marked pigmentation which appeared after repeated irradiation with the uvA + uvB combination. Comparison showed for the improvement of the psoriasis no distinct differences between uvA + uvB irradiation and uvB alone, but the former had the cosmetic advantage of giving pleasing tan

  20. Typicality and reasoning fallacies.

    Science.gov (United States)

    Shafir, E B; Smith, E E; Osherson, D N

    1990-05-01

    The work of Tversky and Kahneman on intuitive probability judgment leads to the following prediction: The judged probability that an instance belongs to a category is an increasing function of the typicality of the instance in the category. To test this prediction, subjects in Experiment 1 read a description of a person (e.g., "Linda is 31, bright, ... outspoken") followed by a category. Some subjects rated how typical the person was of the category, while others rated the probability that the person belonged to that category. For categories like bank teller and feminist bank teller: (1) subjects rated the person as more typical of the conjunctive category (a conjunction effect); (2) subjects rated it more probable that the person belonged to the conjunctive category (a conjunction fallacy); and (3) the magnitudes of the conjunction effect and fallacy were highly correlated. Experiment 2 documents an inclusion fallacy, wherein subjects judge, for example, "All bank tellers are conservative" to be more probable than "All feminist bank tellers are conservative." In Experiment 3, results parallel to those of Experiment 1 were obtained with respect to the inclusion fallacy.

  1. Urinary concentrations of benzophenone-type ultra violet light filters and reproductive parameters in young men

    DEFF Research Database (Denmark)

    Adoamnei, Evdochia; Mendiola, Jaime; Moñino-García, Miriam

    2018-01-01

    BACKGROUND: Benzophenone (BP)-type ultraviolet (UV) light filters are chemicals frequently added to personal care products, insect repellents, sunscreens, and beverage and food packaging to diminish the harmful effects of UV sunlight on human skin or foodstuffs. BP-type UV filters have shown nega...

  2. Wien filter

    OpenAIRE

    Mook, H.W.

    1999-01-01

    The invention relates to a Wien filter provided with electrodes for generating an electric field, and magnetic poles for generating a magnetic field, said electrodes and magnetic poles being positioned around and having a finite length along a filter axis, and being positioned around the filter axis such that electric and magnetic forces induced by the respective fields and exerted on an electrically charged particle moving substantially along the fileter axis at a certain velocity

  3. Determination of ultraviolet filter activity on coconut oil cosmetic cream

    Science.gov (United States)

    Widiyati, Eni

    2017-08-01

    A research on determination of ultraviolet (UV) filter activity of cosmetic cream with coconut oil as raw material has been done. The cream was made by mixing the oil phase (coconut oil, stearic acid, lanolin and cetyl alcohol) at 70°C and the water phase (glycerin, aquadest and triethanolamine) at 70°C, while stirring until reached a temperature of 35°C. It was made also a cream with inorganic sunscreen TiO2 and organic sunscreen benzophenone-3 as a comparison. To study the UV filter activity, each cream was determined the UV absorption using UV spectrophotometer. The results show that cosmetic cream with coconut oil as raw material absorbs UV rays in the region of UV-C, whereas the cream with TiO2 absorbs the UV rays from UV-C to UV-A and cream with benzophenone-3 absorbs the UV rays from UV-B to UV-A region. This means that, the cosmetic cream with coconut oil as raw material has an activity as UV-C filter. If this cream is expected to have an activity as a sunscreen, it must be added an inorganic or organic sunscreen or a mixture of both as an active materials.

  4. Surface-micromachined Bragg Reflectors Based on Multiple Airgap/SiO2 Layers for CMOS-compatible Fabry-perot Filters in the UV-visible Spectral Range

    NARCIS (Netherlands)

    Ghaderi, M.; Ayerden, N.P.; De Graaf, G.; Wolffenbuttel, R.F.

    2014-01-01

    In CMOS-compatible optical filter designs, SiO2 is often used as the low-index material, limiting the optical contrast (nHi/nLo) to about 2. Using the air as low-index material improves the optical contrast by about 50%, thus increasing the reflectivity and bandwidth at a given design complexity.

  5. Ambient UV-B radiation reduces PSII performance and net photosynthesis in high Arctic Salix arctica

    DEFF Research Database (Denmark)

    Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, Helge

    2011-01-01

    Ambient ultraviolet-B (UV-B) radiation potentially impacts the photosynthetic performance of high Arctic plants. We conducted an UV-B exclusion experiment in a dwarf shrub heath in NE Greenland (74°N), with open control, filter control, UV-B filtering and UV-AB filtering, all in combination......, nitrogen and UV-B absorbing compounds. Compared to a 60% reduced UV-B irradiance, the ambient solar UV-B reduced net photosynthesis in Salix arctica leaves fixed in the 45° position which exposed leaves to maximum natural irradiance. Also a reduced Calvin Cycle capacity was found, i.e. the maximum rate...... across position in the vegetation. These findings add to the evidence that the ambient solar UV-B currently is a significant stress factor for plants in high Arctic Greenland....

  6. Filter systems

    International Nuclear Information System (INIS)

    Vanin, V.R.

    1990-01-01

    The multidetector systems for high resolution gamma spectroscopy are presented. The observable parameters for identifying nuclides produced simultaneously in the reaction are analysed discussing the efficiency of filter systems. (M.C.K.)

  7. Optical coatings for the Tropomi UV channel

    Science.gov (United States)

    Brouwer, Martijn; van Buuren, Robin; Gawlitta, Niels; Grabarnik, Semen; van der Valk, Nick; Vink, Rob; van Brug, Hedser; Visser, Huib

    2017-11-01

    Earth observation measurements at wavelengths below 320nm are challenging due to the steep decrease of the earth irradiance towards shorter wavelengths. Stray light and ghosting of longer wave light can easily overwhelm the signals at short wavelengths. In the UV channel (270-320nm) of the TROPOMI instrument this challenge has been addressed using a number of coatings. Three black UV mirror coatings absorb light with a wavelength above 370nm. Together, these achieve more than four orders suppression of long wave out-of-band light. A lowpass transmission filter with a position dependent cut-off wavelength is deposited on the last lens surface, directly in front of the detector. At the position where short wavelength light passes the filter, longer wavelength in-band stray light and ghosts are blocked. A simulation predicts that this graded filter reduces ghosting by a factor 20 and scatter related stray light by factor 30.

  8. Removal of residual particulate matter from filter media

    Energy Technology Data Exchange (ETDEWEB)

    Almlie, Jay C.; Miller, Stanley J.

    2018-01-09

    A method for removing residual filter cakes that remain adhered to a filter after typical particulate removal methodologies have been employed, such as pulse-jet filter element cleaning, for all cleanable filters used for air pollution control, dust control, or powder control.

  9. Improved UV-B screening capacity does not prevent negative effects of ambient UV irradiance on PSII performance in High Arctic plants. Results from a six year UV exclusion study

    DEFF Research Database (Denmark)

    Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

    2010-01-01

    Long-term responses of ambient solar ultraviolet (UV) radiation were investigated on Salix arctica and Vaccinium uliginosum in a High Arctic heath ecosystem in Zackenberg, northeast Greenland. Over a period of six years, UV exclusion was conducted in the growing season by means of filters: 60% UV......, exposing the vegetation to high spring UV-B, and to be present in the future to the degree the ozone layer is not fully recovered....

  10. Alfalfa seedlings grown outdoors are more resistant to UV-induced DNA damage than plants grown in a UV-free environmental chamber

    International Nuclear Information System (INIS)

    Takayanagi, Shinnosuke; Trunk, J.G.; Sutherland, J.C.; Sutherland, B.M.

    1994-01-01

    The relative UV sensitivities of alfalfa seedlings grown outdoors versus plants grown in a growth chamber under UV-filtered cool white fluorescent bulbs have been determined using three criteria: (1) level of endogenous DNA damage as sites for the UV endonuclease from Micrococcus luteus, (2) susceptibility to pyrimidine dimer induction by a UV challenge exposure and (3) ability to repair UV-induced damage. We find that outdoor-grown plants contain approximately equal frequencies of endogenous DNA damages, are less susceptible to dimer induction by a challenge exposure of broad-spectrum UV and photorepair dimers more rapidly than plants grown in an environmental chamber under cool white fluorescent lamps plus a filter removes most UV radiation. These data suggest that plants grown in a natural environment would be less sensitive to UVB-induced damage than would be predicted on the basis of studies on plants grown under minimum UV. (author)

  11. Preventive Long-Term Effects of a Topical Film-Forming Medical Device with Ultra-High UV Protection Filters and DNA Repair Enzyme in Xeroderma Pigmentosum: A Retrospective Study of Eight Cases

    Directory of Open Access Journals (Sweden)

    Sandra Giustini

    2014-09-01

    Full Text Available Skin cancer is common in xeroderma pigmentosum (XP due to a DNA repair mechanisms genetic defect. Ultraviolet (UV exposure is the main cause of increased incidence of actinic keratosis (AK, basal cell carcinoma (BCC and squamous cell carcinoma (SCC observed in XP subjects. Photoprotection is therefore a mandatory strategy in order to reduce skin damage. A topical DNA repair enzyme has been shown to slow down the development of skin lesions in XP. However, there are no data regarding the effects of photoprotection combined with DNA repair strategies in this clinical setting. A film-forming medical device containing the DNA repair enzyme photolyase and very high-protection UV filters (Eryfotona AK-NMSC, Ery is currently available. We report retrospective data regarding the use of Ery in 8 patients (5 women, 3 men with a diagnosis of XP treated for at least 12 consecutive months, comparing the rate of new skin lesions (AK, BCC and SCC during active treatment with Ery and during 12 months just before the use of the product. New AK, BCC and SCC mean lesion numbers during the 1-year Ery treatment were 5, 3 and 0, respectively in comparison with 14, 6.8 and 3 lesions, respectively during the 1-year pre-treatment period. Ery use was associated with a 65% reduction in appearance of new AK lesions and with 56 and 100% reductions in the incidence of new BCC and SCC lesions, respectively. These data suggest that topical use of photoprotection and DNA repair enzyme could help lower skin cancer lesions in XP. Control prospective trials are advisable in this clinical setting.

  12. Outdoor studies on the effects of solar UV-B on bryophytes: overview and methodology.

    NARCIS (Netherlands)

    Boelen, P.; de Boer, M.K.; Bakker, N.; Rozema, J.

    2006-01-01

    In this review all recent field studies on the effects of UV-B radiation on bryophytes are discussed. In most of the studies fluorescent UV-B tubes are used to expose the vegetation to enhanced levels of UV-B radiation to simulate stratospheric ozone depletion. Other studies use screens to filter

  13. Outdoor studies on the effects of solar UV-B on bryophytes : Overview and methodology

    NARCIS (Netherlands)

    Boelen, P.; de Boer, M.K.; de Bakker, N.; Rozema, Jelte

    In this review all recent field studies on the effects of UV-B radiation on bryophytes are discussed. In most of the studies fluorescent UV-B tubes are used to expose the vegetation to enhanced levels of UV-B radiation to simulate stratospheric ozone depletion. Other studies use screens to filter

  14. A UV-Vis photoacoustic spectrophotometer.

    Science.gov (United States)

    Wiegand, Joseph R; Mathews, L Dalila; Smith, Geoffrey D

    2014-06-17

    A novel photoacoustic spectrophotometer (PAS) for the measurement of gas-phase and aerosol absorption over the UV-visible region of the spectrum is described. Light from a broadband Hg arc lamp is filtered in eight separate bands from 300 to 700 nm using bandpass interference filters (centered at 301 nm, 314 nm, 364 nm, 405 nm, 436 nm, 546 nm, 578 and 687 nm) and modulated with an optical chopper before entering the photoacoustic cell. All wavelength bands feature a 20-s detection limit of better than 3.0 Mm(-1) with the exception of the lower-intensity 687 nm band for which it is 10.2 Mm(-1). Validation measurements of gas-phase acetone and nigrosin aerosol absorption cross sections at several wavelengths demonstrate agreement to within 10% with those measured previously (for acetone) and those predicted by Mie theory (for nigrosin). The PAS instrument is used to measure the UV-visible absorption spectrum of ambient aerosol demonstrating a dramatic increase in the UV region with absorption increasing by 300% from 405 to 301 nm. This type of measurement throughout the UV-visible region and free from artifacts associated with filter-based methods has not been possible previously, and we demonstrate its promise for classifying and quantifying different types of light-absorbing ambient particles.

  15. Adaptable Iterative and Recursive Kalman Filter Schemes

    Science.gov (United States)

    Zanetti, Renato

    2014-01-01

    Nonlinear filters are often very computationally expensive and usually not suitable for real-time applications. Real-time navigation algorithms are typically based on linear estimators, such as the extended Kalman filter (EKF) and, to a much lesser extent, the unscented Kalman filter. The Iterated Kalman filter (IKF) and the Recursive Update Filter (RUF) are two algorithms that reduce the consequences of the linearization assumption of the EKF by performing N updates for each new measurement, where N is the number of recursions, a tuning parameter. This paper introduces an adaptable RUF algorithm to calculate N on the go, a similar technique can be used for the IKF as well.

  16. Generalised Filtering

    Directory of Open Access Journals (Sweden)

    Karl Friston

    2010-01-01

    Full Text Available We describe a Bayesian filtering scheme for nonlinear state-space models in continuous time. This scheme is called Generalised Filtering and furnishes posterior (conditional densities on hidden states and unknown parameters generating observed data. Crucially, the scheme operates online, assimilating data to optimize the conditional density on time-varying states and time-invariant parameters. In contrast to Kalman and Particle smoothing, Generalised Filtering does not require a backwards pass. In contrast to variational schemes, it does not assume conditional independence between the states and parameters. Generalised Filtering optimises the conditional density with respect to a free-energy bound on the model's log-evidence. This optimisation uses the generalised motion of hidden states and parameters, under the prior assumption that the motion of the parameters is small. We describe the scheme, present comparative evaluations with a fixed-form variational version, and conclude with an illustrative application to a nonlinear state-space model of brain imaging time-series.

  17. Diabatic initialization using recursive filters

    Science.gov (United States)

    Lynch, Peter; Huang, Xiang-Yu

    1994-10-01

    Several initialization schemes based on recursive filters are formulated and tested with a numerical weather prediction model, HIRLAM. These have an advantage over schemes which use non-recursive filters in that they derive the initialized values from a diabatic trajectory passing through the original analysis. The changes to the analysed fields are comparable in size to typical observational errors. A non-recursive implementation of the recursive filters makes the new initialization schemes as easy to use as the original non-recursive filter schemes. It also allows use of higher-order filters without added cost. An initialization method using a 6th order filter is compared to a scheme based on an non-recursive optimal filter, and is found to produce similar results for less than half the computational cost. If the sole aim is noise suppression, a filter whose output validates later than the initial time may be used. The advantage of this is that computation time is further reduced and phase error completely eliminated.

  18. Olefin metathesis over UV-irradiated silica

    Science.gov (United States)

    Tanaka, Tsunehiro; Matsuo, Shigehiro; Maeda, Takashi; Yoshida, Hisao; Funabiki, Takuzo; Yoshida, Satohiro

    1997-11-01

    Photoirradiated silica evacuated at temperatures higher than 800 K was found to be active for olefin metathesis reactions. The analysis of products shows that the metalacyclobutane intermediate is likely. The instantaneous response of the reaction to the irradiation and the activity change with various UV filter showed that the reaction is induced by UV-excitation of silica. The correlation between the evacuation temperature and the activity showed that the surface free from water molecules plays a role in the reaction and the removal of isolated OH groups strongly relates to the generation of active sites.

  19. UV water disinfector

    Science.gov (United States)

    Gadgil, A.; Garud, V.

    1998-07-14

    A UV disinfector with a gravity driven feed water delivery system and an air-suspended bare UV lamp are disclosed. The disinfector is hydrodynamically optimized with a laminerizing, perforated baffle wall, beveled treatment chamber, and outlet weir. 7 figs.

  20. Comparison of effects of estradiol (E2) with those of octylmethoxycinnamate (OMC) and 4-methylbenzylidene camphor (4MBC) - 2 filters of UV light - on several uterine, vaginal and bone parameters

    International Nuclear Information System (INIS)

    Seidlova-Wuttke, D.; Jarry, H.; Christoffel, J.; Rimoldi, G.; Wuttke, W.

    2006-01-01

    OMC and 4MBC are 2 absorbers of ultraviolet light which are used in unknown quantities in sunscreens, cosmetics and plastic products to protect against UV light-induced damage of the skin or of fragrances or plastic material. From there, they were shown to reach surface water and/or by direct contamination or ingestion the human. Under various conditions in mice and rats, both substances were shown to be estrogenic. Therefore, we compared in vitro and in vivo the effects of chronic application of these compounds at 2 doses with those of E2, all administered via food. No signs of toxicity were observed under application of 0.6 mg E2, 57.5 or 275 mg of OMC, 57.5 or 250 mg of 4MBC; these amounts were ingested with 21 g of control food, 17.8 g E2 food, 20.6 g or 22.3 g OMC food and 23.7 or 22.8 g 4MBC food. In the uterus, vagina and bone, E2 exerted the expected stimulatory effects which were minimally shared by OMC and 4MBC in the uterus and vagina as assessed by histology and determination of a variety of estrogen-regulated genes such as insulin-like growth factor-1, progesterone receptor and estrogen receptor β. In the bone, OMC had no effect, while 4MBC shared the antiosteoporotic effects of E2 as measured by quantitative computer tomography in the metaphysis of the tibia. The mechanism of action of 4MBC, however, appears to be different as E2 reduced serum osteocalcin and the C-terminal breakdown products of collagen-1α1 which were both increased by 4MBC. Taken together, these data indicate a very weak estrogenic effect of OMC and 4MBC in the uterus and in the vagina but not in the bone where 4MBC exerted antiosteoporotic effects by a different mechanism than E2

  1. Comparison of effects of estradiol (E2) with those of octylmethoxycinnamate (OMC) and 4-methylbenzylidene camphor (4MBC)--2 filters of UV light - on several uterine, vaginal and bone parameters.

    Science.gov (United States)

    Seidlová-Wuttke, D; Jarry, H; Christoffel, J; Rimoldi, G; Wuttke, W

    2006-02-01

    OMC and 4MBC are 2 absorbers of ultraviolet light which are used in unknown quantities in sunscreens, cosmetics and plastic products to protect against UV light-induced damage of the skin or of fragrances or plastic material. From there, they were shown to reach surface water and/or by direct contamination or ingestion the human. Under various conditions in mice and rats, both substances were shown to be estrogenic. Therefore, we compared in vitro and in vivo the effects of chronic application of these compounds at 2 doses with those of E2, all administered via food. No signs of toxicity were observed under application of 0.6 mg E2, 57.5 or 275 mg of OMC, 57.5 or 250 mg of 4MBC; these amounts were ingested with 21 g of control food, 17.8 g E2 food, 20.6 g or 22.3 g OMC food and 23.7 or 22.8 g 4MBC food. In the uterus, vagina and bone, E2 exerted the expected stimulatory effects which were minimally shared by OMC and 4MBC in the uterus and vagina as assessed by histology and determination of a variety of estrogen-regulated genes such as insulin-like growth factor-1, progesterone receptor and estrogen receptor beta. In the bone, OMC had no effect, while 4MBC shared the antiosteoporotic effects of E2 as measured by quantitative computer tomography in the metaphysis of the tibia. The mechanism of action of 4MBC, however, appears to be different as E2 reduced serum osteocalcin and the C-terminal breakdown products of collagen-1alpha1 which were both increased by 4MBC. Taken together, these data indicate a very weak estrogenic effect of OMC and 4MBC in the uterus and in the vagina but not in the bone where 4MBC exerted antiosteoporotic effects by a different mechanism than E2.

  2. Eyeglass Filters

    Science.gov (United States)

    1987-01-01

    Biomedical Optical Company of America's suntiger lenses eliminate more than 99% of harmful light wavelengths. NASA derived lenses make scenes more vivid in color and also increase the wearer's visual acuity. Distant objects, even on hazy days, appear crisp and clear; mountains seem closer, glare is greatly reduced, clouds stand out. Daytime use protects the retina from bleaching in bright light, thus improving night vision. Filtering helps prevent a variety of eye disorders, in particular cataracts and age related macular degeneration.

  3. Linear variable optical filter-based ultraviolet microspectrometer

    NARCIS (Netherlands)

    Emadi, A.; Wu, H.; De Graaf, G.; Enoksson, P.; Higino Correia, J.; Wolffenbuttel, R.

    2012-01-01

    An IC-compatible linear variable optical filter (LVOF) for application in the UV spectral range between 310 and 400 nm has been fabricated using resist reflow and an optimized dry-etching. The LVOF is mounted on the top of a commercially available CMOS camera to result in a UV microspectrometer. A

  4. Supervised scale-regularized linear convolutionary filters

    DEFF Research Database (Denmark)

    Loog, Marco; Lauze, Francois Bernard

    2017-01-01

    We start by demonstrating that an elementary learning task—learning a linear filter from training data by means of regression—can be solved very efficiently for feature spaces of very high dimensionality. In a second step, firstly, acknowledging that such high-dimensional learning tasks typically...... filter. In particular, we demonstrate that it clearly outperforms the de facto standard Tikhonov regularization, which is the one employed in ridge regression or Wiener filtering....

  5. Índice UV

    Science.gov (United States)

    Información general sobre el Índice UV que proporciona un pronóstico del riesgo esperado de sobreexposición a la radiación ultravioleta (UV) del sol. El índice UV va acompañado de recomendaciones para protegerse del sol.

  6. Corneal epithelium and UV-protection of the eye.

    Science.gov (United States)

    Ringvold, A

    1998-04-01

    To study UV-absorption and UV-induced fluorescence in the bovine corneal epithelium. Spectrophotometry and spectrofluorimetry. The corneal epithelium absorbs UV-B radiation mainly owing to its content of protein, RNA, and ascorbate. Some of the absorbed energy is transformed to the less biotoxic UV-A radiation by fluorescence. RNA and ascorbate reduce tissue fluorescence. The corneal epithelium acts as a UV-filter, protecting internal eye structures through three different mechanisms: (1) Absorption of UV-B roughly below 310 nm wavelength. (2) Fluorescence-mediated ray transformation to longer wavelengths. (3) Fluorescence reduction. The extremely high ascorbate concentration in the corneal epithelium has a key role in two of these processes.

  7. Digital filters

    CERN Document Server

    Hamming, Richard W

    1997-01-01

    Digital signals occur in an increasing number of applications: in telephone communications; in radio, television, and stereo sound systems; and in spacecraft transmissions, to name just a few. This introductory text examines digital filtering, the processes of smoothing, predicting, differentiating, integrating, and separating signals, as well as the removal of noise from a signal. The processes bear particular relevance to computer applications, one of the focuses of this book.Readers will find Hamming's analysis accessible and engaging, in recognition of the fact that many people with the s

  8. CUVE — Cubesat UV Experiment: Unveil Venus' UV Absorber with Cubesat UV Mapping Spectrometer

    Science.gov (United States)

    Cottini, V.; Aslam, S.; Gorius, N.; Hewagama, T.; Glaze, L.; Ignatiev, N.; Piccioni, G.; D'Aversa, E.

    2017-11-01

    The Cubesat UV Experiment (CUVE) will investigate Venus’ atmosphere at its absorbers at the cloud tops in the UV, with two on-board science payloads (i) a high spectral resolution UV spectrometer and (ii) a multispectral UV imager.

  9. Harmonic Detection at Initialization With Kalman Filter

    DEFF Research Database (Denmark)

    Hussain, Dil Muhammad Akbar; Imran, Raja Muhammad; Shoro, Ghulam Mustafa

    2014-01-01

    the affect of harmonics on the supply. For the detection of these harmonics various techniques are available and one of that technique is the Kalman filter. In this paper we investigate that what are the consequences when harmonic detection system based on Kalman Filtering is initialized......Most power electronic equipment these days generate harmonic disturbances, these devices hold nonlinear voltage/current characteristic. The harmonics generated can potentially be harmful to the consumer supply. Typically, filters are integrated at the power source or utility location to filter out...

  10. Performance Estimation for Lowpass Ternary Filters

    Directory of Open Access Journals (Sweden)

    O'Shea Peter

    2003-01-01

    Full Text Available Ternary filters have tap values limited to , , or . This restriction in tap values greatly simplifies the multipliers required by the filter, making ternary filters very well suited to hardware implementations. Because they incorporate coarse quantisation, their performance is typically limited by tap quantisation error. This paper derives formulae for estimating the achievable performance of lowpass ternary filters, thereby allowing the number of computationally intensive design iterations to be reduced. Motivated by practical communications systems requirements, the performance measure which is used is the worst-case stopband attenuation.

  11. Effects of uv irradiation of nymphs of Blattella germanic and Periplaneta americana

    International Nuclear Information System (INIS)

    Cohen, S.H.; Sousa, J.A.; Roach, J.F.; Gingrich, J.B.

    1975-01-01

    Certain effects of uv irradiation on nymphs of the American cockroach, Periplaneta americana (L.), and the German cockroach, Blattella germanica (L.), were investigated. Of 7 wavelengths to which the nymphs were exposed, 254 and 265 nm were the most effective in producing mortality. The approximate LD 50 dose for nymphs exposed to germicidal (254 nm) uv was 4.56 x 10 4 μ j cm -2 for P. americana and 1.9 x 10 4 μj cm -2 for B. germanica. UV irradiation resulted in retarded feeding and delay in weight gain and molting. Structural abnormalities were observed among adults of those nymphs which were exposed to either pulsed or continuous uv. Pulsed uv was more effective in producing mortality than continuous uv exposure. Nymphs lured to a specific area by food, water, food and water, contaminated filter paper, or filter paper containing a crude extract of aggregation pheromone were killed when irradiated with germicidal (254 nm) uv

  12. Grid impedance estimation via excitation of LCL-filter resonance

    DEFF Research Database (Denmark)

    Liserre, M.; Blaabjerg, Frede; Teodorescu, Remus

    2007-01-01

    Inverters adopted in distributed power generation, active filter, and uninterruptible power supply are often connected to the grid through an inductance-capacitor-inductance (LCL) filter. The impedance of the LCL filter has a typical frequency characteristic with a resonance peak. Hence, the LCL...

  13. Biological responses to current UV-B radiation in Arctic regions

    DEFF Research Database (Denmark)

    Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

    2008-01-01

    on high-arctic vegetation. They supplement previous investigations from the Arctic focussing on other variables like growth etc., which have reported no or minor plant responses to UV-B, and clearly indicates that UV-B radiation is an important factor affecting plant life at high-arctic Zackenberg......Depletion of the ozone layer and the consequent increase in solar ultraviolet-B radiation (UV-B) may impact living conditions for arctic plants significantly. In order to evaluate how the prevailing UV-B fluxes affect the heath ecosystem at Zackenberg (74°30'N, 20°30'W) and other high......-arctic regions, manipulation experiments with various set-ups have been performed. Activation of plant defence mechanisms by production of UV-B absorbing compounds was significant in ambient UV-B in comparison to a filter treatment reducing the UV-B radiation. Despite the UV-B screening response, ambient UV...

  14. Biological responses to current UV-B radiation in Arctic regions

    DEFF Research Database (Denmark)

    Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

    2008-01-01

    (mycorrhiza) or in the biomass of microbes in the soil of the root zone. However, the composition of the soil microbial community was different in the soils under ambient and reduced UV radiation after three treatment years. These results provide new insight into the negative impact of current UV-B fluxes......Depletion of the ozone layer and the consequent increase in solar ultraviolet-B radiation (UV-B) may impact living conditions for arctic plants significantly. In order to evaluate how the prevailing UV-B fluxes affect the heath ecosystem at Zackenberg (74°30'N, 20°30'W) and other high......-arctic regions, manipulation experiments with various set-ups have been performed. Activation of plant defence mechanisms by production of UV-B absorbing compounds was significant in ambient UV-B in comparison to a filter treatment reducing the UV-B radiation. Despite the UV-B screening response, ambient UV...

  15. Comets in UV

    Science.gov (United States)

    Shustov, B.; Sachkov, M.; Gómez de Castro, A. I.; Vallejo, J. C.; Kanev, E.; Dorofeeva, V.

    2018-04-01

    Comets are important "eyewitnesses" of Solar System formation and evolution. Important tests to determine the chemical composition and to study the physical processes in cometary nuclei and coma need data in the UV range of the electromagnetic spectrum. Comprehensive and complete studies require additional ground-based observations and in situ experiments. We briefly review observations of comets in the ultraviolet (UV) and discuss the prospects of UV observations of comets and exocomets with space-borne instruments. A special reference is made to the World Space Observatory-Ultraviolet (WSO-UV) project.

  16. FLOWING BILATERAL FILTER: DEFINITION AND IMPLEMENTATIONS

    Directory of Open Access Journals (Sweden)

    Maxime Moreaud

    2015-06-01

    Full Text Available The bilateral filter plays a key role in image processing applications due to its intuitive parameterization and its high quality filter result, smoothing homogeneous regions while preserving the edges of the objects. Considering the image as a topological relief, seeing pixel intensities as peaks and valleys, we introduce a way to control the tonal weighting coefficients, the flowing bilateral filter, reducing "halo" artifacts typically produced by the regular bilateral filter around a large peak surrounded by two valleys of lower values. In this paper we propose to investigate exact and approximated versions of CPU and parallel GPU (Graphical Processing Unit based implementations of the regular and flowing bilateral filter using the NVidia CUDA API. Fast implementations of these filters are important for the processing of large 3D volumes up to several GB acquired by x-ray or electron tomography.

  17. UV exposure in cars.

    Science.gov (United States)

    Moehrle, Matthias; Soballa, Martin; Korn, Manfred

    2003-08-01

    There is increasing knowledge about the hazards of solar and ultraviolet (UV) radiation to humans. Although people spend a significant time in cars, data on UV exposure during traveling are lacking. The aim of this study was to obtain basic information on personal UV exposure in cars. UV transmission of car glass samples, windscreen, side and back windows and sunroof, was determined. UV exposure of passengers was evaluated in seven German middle-class cars, fitted with three different types of car windows. UV doses were measured with open or closed windows/sunroof of Mercedes-Benz E 220 T, E 320, and S 500, and in an open convertible car (Mercedes-Benz CLK). Bacillus subtilis spore film dosimeters (Viospor) were attached to the front, vertex, cheeks, upper arms, forearms and thighs of 'adult' and 'child' dummies. UV wavelengths longer than >335 nm were transmitted through car windows, and UV irradiation >380 nm was transmitted through compound glass windscreens. There was some variation in the spectral transmission of side windows according to the type of glass. On the arms, UV exposure was 3-4% of ambient radiation when the car windows were shut, and 25-31% of ambient radiation when the windows were open. In the open convertible car, the relative personal doses reached 62% of ambient radiation. The car glass types examined offer substantial protection against short-wave UV radiation. Professional drivers should keep car windows closed on sunny days to reduce occupational UV exposure. In individuals with polymorphic light eruption, produced by long-wave UVA, additional protection by plastic films, clothes or sunscreens appears necessary.

  18. Airborne Microorganism Disinfection by Photocatalytic HEPA Filter

    Directory of Open Access Journals (Sweden)

    Rotruedee Chotigawin

    2010-07-01

    Full Text Available This study determined the efficacy of photocatalytic HEPA filters on microorganism disinfection in a closed-loop chamber and later applied it in an air purifier and tested its efficacy in an 8-m3 chamber and in a hospital. The photocatalytic filters were made by dip-coating a HEPA filter in a TiO2 slurry. In order to disinfect the microorganisms retained on the filter, UV-A light was irradiated onto the filter to create strong oxidative radicals which can destroy microorganisms. The findings showed that disinfection efficiency of the photocatalytic filters with high TiO2 loading was insignificantly higher than with lower loading. S. epidermidis was completely eliminated within 2 hours, while 86.8% of B. subtilis, 77.1% of A. niger, and 82.7% of P. citrinum were destroyed within 10 hours. When applying the photocatalytic filters into an air purifier in a 8-m3 chamber, it was found that as soon as the air purifier was turned on, 83.4% of S. epidermidis, 81.4% of B. subtilis, 88.5% of A. niger, and 75.8% of P. citrinum were removed from the air. In a hospital environment, the PCO air purifier efficacy was lower than that in the chamber. Besides, relative humidity, distances from the air purifier and room size were suspected to affect the efficacy of the photocatalytic filters.

  19. Typical errors of ESP users

    Science.gov (United States)

    Eremina, Svetlana V.; Korneva, Anna A.

    2004-07-01

    The paper presents analysis of the errors made by ESP (English for specific purposes) users which have been considered as typical. They occur as a result of misuse of resources of English grammar and tend to resist. Their origin and places of occurrence have also been discussed.

  20. Dichloromethane removal and microbial variations in a combination of UV pretreatment and biotrickling filtration.

    Science.gov (United States)

    Jianming, Yu; Wei, Liu; Zhuowei, Cheng; Yifeng, Jiang; Wenji, Cai; Jianmeng, Chen

    2014-03-15

    Biofiltration of hydrophobic and/or recalcitrant volatile organic compounds in industry is currently limited. A laboratory-scale system integrating ultraviolet (UV) photodegradation and a biotrickling filter (BTF) was developed to treat dichloromethane (DCM), and this was compared to BTF alone. A combined UV-BTF approach permitted faster biofilm formation and greater removal than BTF. DCM distribution and its photodegradation intermediates revealed that the lower filter of the UV-BTF contributed more to CO2 production; the upper filter assisted more with DCM removal. The UV-BTF kept secretion of extracellular polymeric substances at a normal level with an evenly distributed biomass. Pyrosequencing analysis showed that the dominant population in the combined biofilter was more diverse than that in BTF alone. Our data provide a foundation for understanding the effect of UV pretreatment on BTF performance and the microbial community. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Optimizing UV Index determination from broadband irradiances

    Science.gov (United States)

    Tereszchuk, Keith A.; Rochon, Yves J.; McLinden, Chris A.; Vaillancourt, Paul A.

    2018-03-01

    A study was undertaken to improve upon the prognosticative capability of Environment and Climate Change Canada's (ECCC) UV Index forecast model. An aspect of that work, and the topic of this communication, was to investigate the use of the four UV broadband surface irradiance fields generated by ECCC's Global Environmental Multiscale (GEM) numerical prediction model to determine the UV Index. The basis of the investigation involves the creation of a suite of routines which employ high-spectral-resolution radiative transfer code developed to calculate UV Index fields from GEM forecasts. These routines employ a modified version of the Cloud-J v7.4 radiative transfer model, which integrates GEM output to produce high-spectral-resolution surface irradiance fields. The output generated using the high-resolution radiative transfer code served to verify and calibrate GEM broadband surface irradiances under clear-sky conditions and their use in providing the UV Index. A subsequent comparison of irradiances and UV Index under cloudy conditions was also performed. Linear correlation agreement of surface irradiances from the two models for each of the two higher UV bands covering 310.70-330.0 and 330.03-400.00 nm is typically greater than 95 % for clear-sky conditions with associated root-mean-square relative errors of 6.4 and 4.0 %. However, underestimations of clear-sky GEM irradiances were found on the order of ˜ 30-50 % for the 294.12-310.70 nm band and by a factor of ˜ 30 for the 280.11-294.12 nm band. This underestimation can be significant for UV Index determination but would not impact weather forecasting. Corresponding empirical adjustments were applied to the broadband irradiances now giving a correlation coefficient of unity. From these, a least-squares fitting was derived for the calculation of the UV Index. The resultant differences in UV indices from the high-spectral-resolution irradiances and the resultant GEM broadband irradiances are typically within 0

  2. Quality assurance of the UV irradiances of the UV-B Monitoring and Research Program: the Mauna Loa test case

    Science.gov (United States)

    Zempila, Melina Maria; Davis, John; Janson, George; Olson, Becky; Chen, Maosi; Durham, Bill; Simpson, Scott; Straube, Jonathan; Sun, Zhibin; Gao, Wei

    2017-09-01

    The USDA UV-B Monitoring and Research Program (UVMRP) is an ongoing effort aiming to establish a valuable, longstanding database of ground-based ultraviolet (UV) solar radiation measurements over the US. Furthermore, the program aims to achieve a better understanding of UV variations through time, and develop a UV climatology for the Northern American section. By providing high quality radiometric measurements of UV solar radiation, UVMRP is also focusing on advancing science for agricultural, forest, and range systems in order to mitigate climate impacts. Within these foci, the goal of the present study is to investigate, analyze, and validate the accuracy of the measurements of the UV multi-filter rotating shadowband radiometer (UV-MFRSR) and Yankee (YES) UVB-1 sensor at the high altitude, pristine site at Mauna Loa, Hawaii. The response-weighted irradiances at 7 UV channels of the UV-MFRSR along with the erythemal dose rates from the UVB-1 radiometer are discussed, and evaluated for the period 2006-2015. Uncertainties during the calibration procedures are also analyzed, while collocated groundbased measurements from a Brewer spectrophotometer along with model simulations are used as a baseline for the validation of the data. Besides this quantitative research, the limitations and merits of the existing UVMRP methods are considered and further improvements are introduced.

  3. Polarization control method for UV writing of advanced bragg gratings

    DEFF Research Database (Denmark)

    Deyerl, Hans-Jürgen; Plougmann, Nikolai; Jensen, Jesper Bo Damm

    2002-01-01

    We report the application of the polarization control method for the UV writing of advanced fiber Bragg gratings (FBG). We demonstrate the strength of the new method for different apodization profiles, including the Sinc-profile and two designs for dispersion-free square filters. The method has...

  4. The effects of altered levels of UV-B radiation on an Antarctic grass and lichen

    NARCIS (Netherlands)

    Lud, D.; Huiskes, A.H.L.; Moerdijk-Poortvliet, T.C.W.; Rozema, J.J.

    2001-01-01

    We report a long-term experiment on the photosynthetic response of natural vegetation of Deschampsia antarctica (Poaceae) and Turgidosculum complicatulum (Lichenes) to altered UV-B levels on Leonie Island, Antarctica. UV-B above the vegetation was reduced by filter screens during two seasons. Half

  5. Enabling High Performance Instruments for UV Astronomy and Space Exploration with ALD

    Science.gov (United States)

    Greer, F.; Hoenk, M. E.; Jones, T. J.; Jacquot, B. C.; Monacos, S.; Nikzad, S.; Hamden, E.; Schiminovich, D.

    2011-01-01

    Benefits of Atomic Layer Deposition (ALD) for UV instruments and application are: (1) Ultrathin, highly conformal, and uniform films over arbitrarily large surface area (2) High quality films (density, roughness, conductivity, etc.) (3) Angstrom level control of stoichiometry, interfaces, and surface properties (3a) Multilayer nanolaminates/nanocomposites (3b) Low temperature surface engineering UV flight applications enabled by ALD. (1) Anti -reflective coatings/Mirrors/Filters/Optics for UV/Vis/NIR Detectors (2) Surface Passivation for III -N detectors

  6. Passive Power Filters

    CERN Document Server

    Künzi, R.

    2015-06-15

    Power converters require passive low-pass filters which are capable of reducing voltage ripples effectively. In contrast to signal filters, the components of power filters must carry large currents or withstand large voltages, respectively. In this paper, three different suitable filter struc tures for d.c./d.c. power converters with inductive load are introduced. The formulas needed to calculate the filter components are derived step by step and practical examples are given. The behaviour of the three discussed filters is compared by means of the examples. P ractical aspects for the realization of power filters are also discussed.

  7. Filter replacement lifetime prediction

    Science.gov (United States)

    Hamann, Hendrik F.; Klein, Levente I.; Manzer, Dennis G.; Marianno, Fernando J.

    2017-10-25

    Methods and systems for predicting a filter lifetime include building a filter effectiveness history based on contaminant sensor information associated with a filter; determining a rate of filter consumption with a processor based on the filter effectiveness history; and determining a remaining filter lifetime based on the determined rate of filter consumption. Methods and systems for increasing filter economy include measuring contaminants in an internal and an external environment; determining a cost of a corrosion rate increase if unfiltered external air intake is increased for cooling; determining a cost of increased air pressure to filter external air; and if the cost of filtering external air exceeds the cost of the corrosion rate increase, increasing an intake of unfiltered external air.

  8. Tap water filters.

    Science.gov (United States)

    2003-02-01

    Moen PureTouch filters remove impurities from tap water without removing fluoride. These carbon block filters consist of finely powdered activated carbon that is combined with a plastic binder material and heated to form a hollow cylinder. The blocks are further wrapped with material to improve performance and reduce clogging. The filters are available with different filtering capabilities (Table 1). The filters mount in the faucet spout or under the sink.

  9. Gas permeability through thin-foil x-ray filters

    Science.gov (United States)

    Tveekrem, June L.; Keski-Kuha, Ritva A.; Webb, Andrew T.

    1997-10-01

    We have measured the permeation rates of helium and water through thin-foil UV-blocking filters used in the ASTRO-E/x- ray spectrometer (XRS) instrument. In the XRS program, there is a concern that outgassed contaminants such as water could permeate through the outermost filter which will be at room temperature and freeze on the inner filters which will be at cryogenic temperatures. The filters tested consisted of approximately 1000 angstroms Al on approximately 1000 angstroms of either Lexan or polyimide. Measurements were made using a vacuum apparatus consisting essentially of two small chambers separated by the filter under test. A helium leak detector was used to measure helium permeation rates, and a residual gas analyzer (RGA) was used to detect water. Results discussed include permeation rate as a function of pressure difference across a filter, the ratio of helium permeation rate over water permeation rate, and the effect of the aluminum layer thickness on permeation.

  10. Epidermal UV-A absorbance and whole-leaf flavonoid composition in pea respond more to solar blue light than to solar UV radiation.

    Science.gov (United States)

    Siipola, Sari M; Kotilainen, Titta; Sipari, Nina; Morales, Luis O; Lindfors, Anders V; Robson, T Matthew; Aphalo, Pedro J

    2015-05-01

    Plants synthesize phenolic compounds in response to certain environmental signals or stresses. One large group of phenolics, flavonoids, is considered particularly responsive to ultraviolet (UV) radiation. However, here we demonstrate that solar blue light stimulates flavonoid biosynthesis in the absence of UV-A and UV-B radiation. We grew pea plants (Pisum sativum cv. Meteor) outdoors, in Finland during the summer, under five types of filters differing in their spectral transmittance. These filters were used to (1) attenuate UV-B; (2) attenuate UV-B and UV-A light; and (5) as a control not attenuating these wavebands. Attenuation of blue light significantly reduced the flavonoid content in leaf adaxial epidermis and reduced the whole-leaf concentrations of quercetin derivatives relative to kaempferol derivatives. In contrast, UV-B responses were not significant. These results show that pea plants regulate epidermal UV-A absorbance and accumulation of individual flavonoids by perceiving complex radiation signals that extend into the visible region of the solar spectrum. Furthermore, solar blue light instead of solar UV-B radiation can be the main regulator of phenolic compound accumulation in plants that germinate and develop outdoors. © 2014 John Wiley & Sons Ltd.

  11. UV Resonant Raman Spectrometer with Multi-Line Laser Excitation

    Science.gov (United States)

    Lambert, James L.; Kohel, James M.; Kirby, James P.; Morookian, John Michael; Pelletier, Michael J.

    2013-01-01

    A Raman spectrometer employs two or more UV (ultraviolet) laser wavel engths to generate UV resonant Raman (UVRR) spectra in organic sampl es. Resonant Raman scattering results when the laser excitation is n ear an electronic transition of a molecule, and the enhancement of R aman signals can be several orders of magnitude. In addition, the Ra man cross-section is inversely proportional to the fourth power of t he wavelength, so the UV Raman emission is increased by another fact or of 16, or greater, over visible Raman emissions. The Raman-scatter ed light is collected using a high-resolution broadband spectrograph . Further suppression of the Rayleigh-scattered laser light is provi ded by custom UV notch filters.

  12. Solar UV-B effects on PSII performance in Betula nana are influenced by PAR level and reduced by EDU

    DEFF Research Database (Denmark)

    Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, Helge

    2012-01-01

    The long-term and diurnal responses of photosystem II (PSII) performance to near-ambient UV-B radiation were investigated in High Arctic Betula nana. We conducted an UV exclusion experiment with five replicated blocks consisting of open control (no filter), photosynthetic active radiation and UV...... the effects of UV-B. Chlorophyll-a fluorescence induction curves were used for analysis of OJIP test parameters. Near-ambient UV-B radiation reduced across season maximum quantum yield (TRo /ABS = Fv /Fm ), approximated number of active PSII reaction center (RC/ABS) and the performance index (PIABS ), despite...... improved leaf screening against UV-B with higher content of UV-B-absorbing compounds and a lower specific leaf area. EDU application counteracted the negative impact of UV-B on TR(o) /ABS, RC/ABS and PI(ABS) . This indicates that the mechanisms behind UV-B and ozone damage share some common features...

  13. Bioequivalent UV detectors based on cholesteric liquid crystals: effects of spectral composition and quantitative account for intensity of UV radiation

    Science.gov (United States)

    Lisetski, Longin N.; Panikarskaya, Valentina D.; Kasyan, Natalya A.; Grishchenko, Leonid V.; Terenetskaya, Irina P.

    2005-11-01

    Response of cholesteric sensor materials to biologically active UV radiation has been studied. The sensor mixture comprised a cholesteric liquid crystalline matrix doped with provitamin D, and changes in the maximum selective reflection wavelength λ max caused by the photochemical reaction of provitamin D --> vitamin D transformation were recorded. Using a UV source (DRT-240 lamp) calibrated accounting for the specific irradiation geometry, λ max shifts were obtained as function of UV illuminance dose (in J/cm2). Using a set of optical filters cutting off specified parts of the provitamin D absorption spectrum, effects of the spectral composition of UV radiation upon the response characteristics of sensor were determined. The results obtained support our earlier considerations of the developed sensor material as "bioequivalent".

  14. HEPA Filter Vulnerability Assessment

    International Nuclear Information System (INIS)

    GUSTAVSON, R.D.

    2000-01-01

    This assessment of High Efficiency Particulate Air (HEPA) filter vulnerability was requested by the USDOE Office of River Protection (ORP) to satisfy a DOE-HQ directive to evaluate the effect of filter degradation on the facility authorization basis assumptions. Within the scope of this assessment are ventilation system HEPA filters that are classified as Safety-Class (SC) or Safety-Significant (SS) components that perform an accident mitigation function. The objective of the assessment is to verify whether HEPA filters that perform a safety function during an accident are likely to perform as intended to limit release of hazardous or radioactive materials, considering factors that could degrade the filters. Filter degradation factors considered include aging, wetting of filters, exposure to high temperature, exposure to corrosive or reactive chemicals, and exposure to radiation. Screening and evaluation criteria were developed by a site-wide group of HVAC engineers and HEPA filter experts from published empirical data. For River Protection Project (RPP) filters, the only degradation factor that exceeded the screening threshold was for filter aging. Subsequent evaluation of the effect of filter aging on the filter strength was conducted, and the results were compared with required performance to meet the conditions assumed in the RPP Authorization Basis (AB). It was found that the reduction in filter strength due to aging does not affect the filter performance requirements as specified in the AB. A portion of the HEPA filter vulnerability assessment is being conducted by the ORP and is not part of the scope of this study. The ORP is conducting an assessment of the existing policies and programs relating to maintenance, testing, and change-out of HEPA filters used for SC/SS service. This document presents the results of a HEPA filter vulnerability assessment conducted for the River protection project as requested by the DOE Office of River Protection

  15. A Modal Model to Simulate Typical Structural Dynamic Nonlinearity

    Energy Technology Data Exchange (ETDEWEB)

    Pacini, Benjamin Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mayes, Randall L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roettgen, Daniel R [Univ. of Wisconsin, Madison, WI (United States)

    2015-10-01

    Some initial investigations have been published which simulate nonlinear response with almost traditional modal models: instead of connecting the modal mass to ground through the traditional spring and damper, a nonlinear Iwan element was added. This assumes that the mode shapes do not change with amplitude and there are no interactions between modal degrees of freedom. This work expands on these previous studies. An impact experiment is performed on a structure which exhibits typical structural dynamic nonlinear response, i.e. weak frequency dependence and strong damping dependence on the amplitude of vibration. Use of low level modal test results in combination with high level impacts are processed using various combinations of modal filtering, the Hilbert Transform and band-pass filtering to develop response data that are then fit with various nonlinear elements to create a nonlinear pseudo-modal model. Simulations of forced response are compared with high level experimental data for various nonlinear element assumptions.

  16. Evaporation of Sunscreen Films: How the UV Protection Properties Change.

    Science.gov (United States)

    Binks, Bernard P; Brown, Jonathan; Fletcher, Paul D I; Johnson, Andrew J; Marinopoulos, Ioannis; Crowther, Jonathan M; Thompson, Michael A

    2016-06-01

    We have investigated the evaporation of thin sunscreen films and how the light absorption and the derived sun protection factor (SPF) change. For films consisting of solutions of common UV filters in propylene glycol (PG) as solvent, we show how evaporation generally causes three effects. First, the film area can decrease by dewetting leading to a transient increase in the average film thickness. Second, the film thins by evaporative loss of the solvent. Third, precipitation of the UV filter occurs when solvent loss causes the solubility limit to be reached. These evaporation-induced changes cause the UV absorbance of the film to decrease with resultant loss of SPF over the time scale of the evaporation. We derive an approximate model which accounts semiquantitatively for the variation of SPF with evaporation. Experimental results for solutions of different UV filters on quartz, different skin mimicking substrates, films with added nanoparticles, films with an added polymer and films with fast-evaporating decane as solvent (instead of slow evaporating PG) are discussed and compared with model calculations. Addition of either nanoparticles or polymer suppress film dewetting. Overall, it is hoped that the understanding gained about the mechanisms whereby film evaporation affects the SPF will provide useful guidance for the formulation of more effective sunscreens.

  17. Kinetic parameters of uracil dosimeter in simulated extraterrestrial UV radiation

    Science.gov (United States)

    Kovács, G.; Gróf, P.; Bérces, A.; Patel, M. R.; Lammer, H.; Rontó, Gy.

    Studies of the solar UV environment on Earth 2.0 Gyr to 3.8 Gyr ago suggest that the terrestrial atmosphere was essentially anoxic, resulting in an ozone column abundance insufficient for protecting the planetary surface in the UV-B (280 nm - 315 nm) and the UV-C (200 nm - 280 nm) ranges. Since, short wavelength solar UV radiation in the UV-B and UV-C range penetrated through the atmosphere to the unprotected early Earth's surface, associated biological consequences may be expected. We discuss experimental data obtained as follows: Radiation sources applied were solar simulator and high power deuterium lamp, the wavelength were adjusted by interference filters (210, 230, 250 nm) and the irradiances were measured by OL754 spectroradiometer. The photo-reverse effect depends highly on the wavelength of the exposed radiation. Shorter wavelength UV radiation of about 200 nm is strongly effective in monomerization, while the longer wavelengths prefer the production of dimerization. In case of polychromatic light, like in space or on a planetary surface which is unprotected by an ozone layer the two processes run parallel. We could demonstrate experimentally, for the case of a uracil thin-layer that the photo-reaction process of the nucleotides can be both dimerization and the reverse process: monomerization. These results are important for the study of solar UV effects on organisms in the early terrestrial environment as well as for the search for life on Mars since we can show that biological harmful effects can also be reduced by shorter wavelength UV radiation, which is of importance in reducing DNA damages provoked by wavelengths longer than about 240 nm. Our earlier results showed that dimerization of the pyrimidin base uracil can be described by a first order kinetics, and this reaction gives the possibility to determine the dose of the UV source applied. This work is a theoretical and experimental approach to the relevant parameters of the first order kinetics.

  18. HEPA filter monitoring program

    Science.gov (United States)

    Kirchner, K. N.; Johnson, C. M.; Aiken, W. F.; Lucerna, J. J.; Barnett, R. L.; Jensen, R. T.

    1986-07-01

    The testing and replacement of HEPA filters, widely used in the nuclear industry to purify process air, are costly and labor-intensive. Current methods of testing filter performance, such as differential pressure measurement and scanning air monitoring, allow determination of overall filter performance but preclude detection of incipient filter failure such as small holes in the filters. Using current technology, a continual in-situ monitoring system was designed which provides three major improvements over current methods of filter testing and replacement. The improvements include: cost savings by reducing the number of intact filters which are currently being replaced unnecessarily; more accurate and quantitative measurement of filter performance; and reduced personnel exposure to a radioactive environment by automatically performing most testing operations.

  19. Bias aware Kalman filters

    DEFF Research Database (Denmark)

    Drecourt, J.-P.; Madsen, H.; Rosbjerg, Dan

    2006-01-01

    This paper reviews two different approaches that have been proposed to tackle the problems of model bias with the Kalman filter: the use of a colored noise model and the implementation of a separate bias filter. Both filters are implemented with and without feedback of the bias into the model state...... are illustrated on a simple one-dimensional groundwater problem. The results show that the presented filters outperform the standard Kalman filter and that the implementations with bias feedback work in more general conditions than the implementations without feedback. 2005 Elsevier Ltd. All rights reserved........ The colored noise filter formulation is extended to correct both time correlated and uncorrelated model error components. A more stable version of the separate filter without feedback is presented. The filters are implemented in an ensemble framework using Latin hypercube sampling. The techniques...

  20. New observation strategies for the solar UV spectral irradiance

    Directory of Open Access Journals (Sweden)

    Kretzschmar Matthieu

    2012-09-01

    Full Text Available Many applications in space weather and in space situational awareness require continuous solar spectral irradiance measurements in the UV, and to a lesser degree in the visible band. Most space-borne solar radiometers are made out of two different parts: (i a front filter that selects the passband and (ii a detector that is usually based on silicon technology. Both are prone to degradation, which may be caused either by the degradation of the filter coating due to local deposition or to structural changes, or by the degradation of the silicon detector by solar radiative and energetic particle fluxes. In this study, we provide a theoretical analysis of the filter degradation that is caused by structural changes such as pinholes; contamination-induced degradation will not be considered. We then propose a new instrumental concept, which is expected to overcome, at least partially, these problems. We show how most of the solar UV spectrum can be reconstructed from the measurement of only five spectral bands. This instrumental concept outperforms present spectrometers in terms of degradation. This new concept in addition overcomes the need for silicon-based detectors, which are replaced by wide band gap material detectors. Front filters, which can contribute to in-flight degradation, therefore are not required, except for the extreme-UV (EUV range. With a small weight and a low telemetry, this concept may also have applications in solar physics, in astrophysics and in planetology.

  1. MST Filterability Tests

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Burket, P. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Duignan, M. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-03-12

    The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). The low filter flux through the ARP has limited the rate at which radioactive liquid waste can be treated. Recent filter flux has averaged approximately 5 gallons per minute (gpm). Salt Batch 6 has had a lower processing rate and required frequent filter cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. In addition, at the time the testing started, SRR was assessing the impact of replacing the 0.1 micron filter with a 0.5 micron filter. This report describes testing of MST filterability to investigate the impact of filter pore size and MST particle size on filter flux and testing of filter enhancers to attempt to increase filter flux. The authors constructed a laboratory-scale crossflow filter apparatus with two crossflow filters operating in parallel. One filter was a 0.1 micron Mott sintered SS filter and the other was a 0.5 micron Mott sintered SS filter. The authors also constructed a dead-end filtration apparatus to conduct screening tests with potential filter aids and body feeds, referred to as filter enhancers. The original baseline for ARP was 5.6 M sodium salt solution with a free hydroxide concentration of approximately 1.7 M.3 ARP has been operating with a sodium concentration of approximately 6.4 M and a free hydroxide concentration of approximately 2.5 M. SRNL conducted tests varying the concentration of sodium and free hydroxide to determine whether those changes had a significant effect on filter flux. The feed slurries for the MST filterability tests were composed of simple salts (NaOH, NaNO2, and NaNO3) and MST (0.2 – 4.8 g/L). The feed slurry for the filter enhancer tests contained simulated salt batch 6 supernate, MST, and filter enhancers.

  2. Nitric oxide is involved in integration of UV-B absorbing compounds among parts of clonal plants under a heterogeneous UV-B environment.

    Science.gov (United States)

    Liu, Xiao; Li, Qian; Yue, Ming; Zhang, Xiaofei; Zhang, Ruichang; Zhang, Bing; Wang, Ming

    2014-11-26

    In nature, ultraviolet-B (UV-B) radiation is highly heterogeneous, both spatially and temporally. Plants exposed to UV-B radiation produce UV-B absorbing compounds that function as a protective filter. For clonal plants under heterogeneous UV-B radiation conditions, integration among ramets can allow irradiated ramets to benefit un-irradiated ramets by causing them to increase their UV-B absorbing compounds content. In this study, we evaluated integration between pairs of clonal ramets of Glechoma longituba under heterogeneous or homogeneous UV-B conditions. We determined the levels of UV-B absorbing compounds, nitric oxide (NO) and hydrogen peroxide (H 2 O 2 ) and measured the activity of phenylalanine ammonia-lyase (PAL) in connected ramet pairs under homogeneous or heterogeneous UV-B conditions. Under heterogeneous UV-B conditions, the UV-B absorbing compounds content increased in leaves of irradiated and un-irradiated ramets, but not in the connecting stolons. The NO content increased in irradiated and un-irradiated leaves and stolons, but the H 2 O 2 content did not. Application of NO synthesis inhibitors and an NO blocker to irradiated ramets blocked the increase in UV-B absorbing compounds and PAL activity in un-irradiated ramets. These results suggested that NO is involved in the integration process for UV-B absorbing compounds among ramets. Our findings suggested that a UV-B-induced increase in NO transmits a signal to un-irradiated ramets via the stolon, leading to an increase in PAL activity and UV-B absorbing compounds content. The internal translocation of signal enables members of clonal networks to function as a whole unit and to mount an efficient defensive response to localized UV-B radiation. © 2014 Scandinavian Plant Physiology Society.

  3. Updating the OMERACT filter

    DEFF Research Database (Denmark)

    Kirwan, John R; Boers, Maarten; Hewlett, Sarah

    2014-01-01

    OBJECTIVE: The Outcome Measures in Rheumatology (OMERACT) Filter provides guidelines for the development and validation of outcome measures for use in clinical research. The "Truth" section of the OMERACT Filter presupposes an explicit framework for identifying the relevant core outcomes that are......OBJECTIVE: The Outcome Measures in Rheumatology (OMERACT) Filter provides guidelines for the development and validation of outcome measures for use in clinical research. The "Truth" section of the OMERACT Filter presupposes an explicit framework for identifying the relevant core outcomes...

  4. Oriented Fiber Filter Media

    OpenAIRE

    R. Bharadwaj; A. Patel, S. Chokdeepanich, Ph.D.; G.G. Chase, Ph.D.

    2008-01-01

    Coalescing filters are widely used throughout industry and improved performance will reduce droplet emissions and operating costs. Experimental observations show orientation of micro fibers in filter media effect the permeability and the separation efficiency of the filter media. In this work two methods are used to align the fibers to alter the filter structure. The results show that axially aligned fiber media improve quality factor on the order of 20% and cutting media on an angle from a t...

  5. UV spectroscopy. Ch. 16

    International Nuclear Information System (INIS)

    Stevens, Eugene S.

    1991-01-01

    The use of synchrotron radiation (SR) in the ultraviolet (UV) region by biophysics and biophysical chemists continues to increase as access improves and as awareness of its unique combination of properties grows. SR is continuously tunable, intense (even in the UV region), and pulsed. Pulse characteristics are comparable to those of picosecond lasers, but have the advantage of being independent of wavelength. Drawbacks are the continuous, but slow, decay of intensity arising from loss of particles in the ring, and the intrinsic limitation in pulse repetition rate. The particular combination of features that makes SR a superior light source depends upon the application. Spectroscopic techniques based on absorption and some techniques based on emission exploit its intensity and continuous tunability; time resolved techniques make use of its pulse characteristics. This chapter is a status report on two of the major biological applications of UV SR, circular dichroism and time-resolved fluorescence, covering mainly the published literature of the last five years. For the present purpose, the term UV is understood to include the vacuum ultraviolet region to 100 nm. (author). 83 refs.; 4 figs.; 6 tabs

  6. HEPA filter encapsulation

    Science.gov (United States)

    Gates-Anderson, Dianne D.; Kidd, Scott D.; Bowers, John S.; Attebery, Ronald W.

    2003-01-01

    A low viscosity resin is delivered into a spent HEPA filter or other waste. The resin is introduced into the filter or other waste using a vacuum to assist in the mass transfer of the resin through the filter media or other waste.

  7. Filter service system

    Science.gov (United States)

    Sellers, Cheryl L [Peoria, IL; Nordyke, Daniel S [Arlington Heights, IL; Crandell, Richard A [Morton, IL; Tomlins, Gregory [Peoria, IL; Fei, Dong [Peoria, IL; Panov, Alexander [Dunlap, IL; Lane, William H [Chillicothe, IL; Habeger, Craig F [Chillicothe, IL

    2008-12-09

    According to an exemplary embodiment of the present disclosure, a system for removing matter from a filtering device includes a gas pressurization assembly. An element of the assembly is removably attachable to a first orifice of the filtering device. The system also includes a vacuum source fluidly connected to a second orifice of the filtering device.

  8. UV-induced recessive lethals in uvs strains of Neurospora which are deficient in UV mutagenesis

    International Nuclear Information System (INIS)

    Kaefer, E.

    1984-01-01

    The frequencies of spontaneous and UV-induced recessive lethal mutations were compared for UV-sensitive and wild-type heterokaryons of Neurospora crassa. These heterokaryons were homokaryotic either for one of two alleles of uvs-3, or for uvs-6 or uvs + . For uvs-3, which is known to have mutator effects, spontaneous recessive lethals were found to be 4-6 times more frequent than observed in uvs + . After correction for clonal distribution of spontaneous mutants, an observed 2-fold increase for uvs-6 was not statistically significant and may have been due to chance occurrence of a few large clones of mutants. Treatment with low doses of UV (50-200 J/m 2 ) produced very similar overall rates of increase for recessive lethals in uvs and uvs + heterokaryons. This means, that in contrast to results obtained when mutation to ad-3 was measured, both uvs-3 alleles showed highly significant increases for recessive lethals when treated with UV. It is proposed that certain types of UV damage may be processed into recessive lethal mutations by an alternate mechanism from that responsible for viable mutations. (Auth.)

  9. Changes in growth and 14CO2 fixation of Hordeum vulgare and Phaseolus vulgaris induced by UV-B radiation

    International Nuclear Information System (INIS)

    Moussa, H.R.; Khodary, S.A.

    2008-01-01

    Increased UV-B radiation on the earth's surface due to depletion of stratospheric ozone layer is one of the changes of current climate-change pattern. A field experiment was concluded to study the effects of solar ultraviolet-B (UV-B) radiation on growth parameters, photosynthetic efficiency (14CO2-fixation) and biochemical characteristics of barley (Hordeum vulgare) and common bean (Phaseolus vulgaris). Plants grown under ambient UV-B radiation were compared with those grown without UV-B by excluding ambient UV-B radiation. To exclude solar ambient UV-B radiation, the sunlight was filtered through a polyester film that selectively absorbed UV-B. For ambient UV-B effects, plants were grown under polyvinyl chloride (PVC) filters that transmitted the complete light spectrum. The results indicated increased shoot length, leaf area, dry matter accumulation, leaf area ratio and specific leaf weight in plants of both the crops grown without UV-B compared with those grown under ambient UV-B. Similarly, the rate of photosynthetic activity, chlorophyll content, nitrates reductase (NR) enzyme activity and sugar content. The effect of UV-B exclusion was clearer in common bean compared with that in barley. We conclude that monocot species may be less sensitive to increased solar UV-B due to ozone depletion than with dicots

  10. The Novel Microwave Stop-Band Filter

    Directory of Open Access Journals (Sweden)

    R. E. Chernobrovkin

    2008-01-01

    Full Text Available The stop-band filter with the new band-rejection element is proposed. The element is a coaxial waveguide with the slot in the centre conductor. In the frame of this research, the numerical and experimental investigations of the amplitude-frequency characteristics of the filter are carried out. It is noted that according to the slot parameters the two typical resonances (half-wave and quarter-wave can be excited. The rejection band of the single element is defined by the width, depth, and dielectric filling of the slot. Fifth-order Chebyshev filter utilizing the aforementioned element is also synthesized, manufactured, and tested. The measured and simulated results are in good agreement. The experimental filter prototype exhibits the rejection band 0.86 GHz at the level −40 dB.

  11. Balanced microwave filters

    CERN Document Server

    Hong, Jiasheng; Medina, Francisco; Martiacuten, Ferran

    2018-01-01

    This book presents and discusses strategies for the design and implementation of common-mode suppressed balanced microwave filters, including, narrowband, wideband, and ultra-wideband filters This book examines differential-mode, or balanced, microwave filters by discussing several implementations of practical realizations of these passive components. Topics covered include selective mode suppression, designs based on distributed and semi-lumped approaches, multilayer technologies, defect ground structures, coupled resonators, metamaterials, interference techniques, and substrate integrated waveguides, among others. Divided into five parts, Balanced Microwave Filters begins with an introduction that presents the fundamentals of balanced lines, circuits, and networks. Part 2 covers balanced transmission lines with common-mode noise suppression, including several types of common-mode filters and the application of such filters to enhance common-mode suppression in balanced bandpass filters. Next, Part 3 exa...

  12. Exhaust gas filter

    International Nuclear Information System (INIS)

    Wada, Tadamasa; Hiraki, Akimitsu.

    1993-01-01

    A filter material formed by joining glass clothes to both surfaces of a glass fiber non-woven fabric is used. The filter material is disposed at the inside of a square filter material support frame made of stainless steel. The filter material is attached in a zig-zag manner in the flowing direction of the exhaust gases so as to increase the filtration area. Separators, for example, made of stainless steel are inserted between the filter materials. The separator is corrugated so as to sandwich and support the filter materials from both sides by the ridged crests. The longitudinal bottom of the separator formed by corrugating it defines a flow channel of the exhaustion gases. The longitudinal bottom is also used as a channel for back blowing air. With such a constitution, combustion gases of radioactive miscellaneous solid wastes can be completely filtered. In addition, a back wash can be conducted under high temperature. (I.N.)

  13. Changing ventilation filters

    International Nuclear Information System (INIS)

    Hackney, S.

    1980-01-01

    A filter changing unit has a door which interlocks with the door of a filter chamber so as to prevent contamination of the outer surfaces of the doors by radioactive material collected on the filter element and a movable support which enables a filter chamber thereonto to be stored within the unit in such a way that the doors of the unit and the filter chamber can be replaced. The door pivots and interlocks with another door by means of a bolt, a seal around the periphery lip of the first door engages the periphery of the second door to seal the gap. A support pivots into a lower filter element storage position. Inspection windows and glove ports are provided. The unit is releasably connected to the filter chamber by bolts engaging in a flange provided around an opening. (author)

  14. Artificial bias typically neglected in comparisons of uncertain atmospheric data

    Science.gov (United States)

    Arola, A. T.; Pitkänen, M. R. A.; Mikkonen, S.; Lipponen, A.; Lehtinen, K. E.

    2016-12-01

    Researchers in atmospheric sciences typically neglect biases caused by regression dilution and regression to the mean (RTM) in comparisons of uncertain data. Regression dilution occurs when the ordinary least squares regression method is used on a predictor with random data uncertainty, which causes the slope to become biased towards zero. RTM on the other hand happens when an extreme observation is accompanied by a less extreme follow-up observation. These biases both originate from random uncertainties of the reference data, which is typically not taken into account and discussed in atmospheric sciences. This is crucial, since essentially all typical atmospheric data have some level of uncertainty. We use synthetic observations of aerosol optical thickness and UV index mimicking real atmospheric data to demonstrate how the biases arise from random data uncertainties of measurements, model output, or satellite retrieval products. Further, we provide examples of typical methods of data comparisons that have a tendency to pronounce the biases. The results show, that data uncertainties can significantly bias data comparisons due regression dilution and RTM, a fact that is known in statistics, but disregarded in atmospheric sciences. Thus we argue, that often these biases are widely regarded as measurement or modeling errors, for instance, while they in fact are artificial. It is essential that atmospheric and geoscience communities become aware of and consider features in research.

  15. Post-correlation filtering techniques for off-axis source and RFI removal

    NARCIS (Netherlands)

    Offringa, A. R.; de Bruyn, A. G.; Zaroubi, S.

    Techniques to improve the data quality of interferometric radio observations are considered. Fundaments of fringe frequencies in the uv-plane are discussed and filters are used to attenuate radio-frequency interference (RFI) and off-axis sources. Several new applications of filters are introduced

  16. Synthetic ultraviolet light filtering chemical contamination of coastal waters of Virgin Islands National Park, St. John, U.S. Virgin Islands

    Science.gov (United States)

    Bargar, Timothy A.; Alvarez, David; Garrison, Virginia H.

    2015-01-01

    Contamination of surface waters by synthetic ultraviolet light (UV) filtering chemicals is a concern for the Virgin Islands National Park (VINP). Discrete water samples were collected from VINP bays to determine UV filter chemical presence in the coastal waters. Spatial distribution and the potential for partitioning between subsurface waters and the sea surface microlayer (SML) were also examined. The UV filter chemicals 4-methylbenzylidene camphor, benzophenone-3, octinoxate, homosalate, and octocrylene were detected at concentrations up to 6073 ng/L (benzophenone-3). Concentrations for benzophenone-3 and homosalate declined exponentially (r2 = 0.86 to 0.98) with distance from the beach. Limited data indicate that some UV filter chemicals may partition to the SML relative to the subsurface waters. Contamination of VINP coastal waters by UV filter chemicals may be a significant issue, but an improved understanding of the temporal and spatial variability of their concentrations would be necessary to better understand the risk they present.

  17. Growth, photosynthesis and nitrogen metabolism in soybean varieties after exclusion of the UV-B and UV-A/B components of solar radiation

    Directory of Open Access Journals (Sweden)

    Sanjay Singh Baroniya

    2014-12-01

    Full Text Available A field experiment was conducted to study the impact of the exclusion of the solar UV components on growth, photosynthesis and nitrogen metabolism in soybean (Glycine max varieties PK-472, Pusa-24, JS 71-05, JS-335, NRC-7 and Kalitur. The plants were grown in specially designed UV exclusion chambers wrapped with filters to exclude UV-B or UV-A/B and transmitted all UV. Exclusion of UV significantly enhanced the growth of the aerial parts as well as the growth of the below ground parts in all of the six soybean varieties. Nitrate reductase activity (NRA was significantly reduced, whereas leghemoglobin (Lb content, total soluble protein, net photosynthesis (Pn and α-tocopherol content were enhanced after UV exclusion. The exclusion of solar UV-A/B enhanced all parameters to a larger extent than the exclusion of solar UV-B in four of the six varieties of soybean except for NRC-7 and Kalitur. These two varieties responded more to UV-B exclusion compared to UV-A/B exclusion. A significant inverse correlation between the NRA and the number of nodules per plant was observed. The extent of response in all parameters was greater in PK-472 and JS71-05 than that in Kalitur and JS-335 after UV exclusion. The exclusion of UV augmented the growth of nodules, Lb content and α-tocopherol levels and conferred higher rates of Pn to support better growth of nodules. Control plants (+ UV-A/B seemed to fulfill their N demand through the assimilation of NO3− resulting in lower symbiotic nitrogen fixation and higher NR activity.

  18. EXPLICIT LEAST-DEGREE BOUNDARY FILTERS FOR DISCONTINUOUS GALERKIN*

    Science.gov (United States)

    Nguyen, Dang-Manh; Peters, Jörg

    2017-01-01

    Convolving the output of Discontinuous Galerkin (DG) computations using spline filters can improve both smoothness and accuracy of the output. At domain boundaries, these filters have to be one-sided for non-periodic boundary conditions. Recently, position-dependent smoothness-increasing accuracy-preserving (PSIAC) filters were shown to be a superset of the well-known one-sided RLKV and SRV filters. Since PSIAC filters can be formulated symbolically, PSIAC filtering amounts to forming linear products with local DG output and so offers a more stable and efficient implementation. The paper introduces a new class of PSIAC filters NP0 that have small support and are piecewise constant. Extensive numerical experiments for the canonical hyperbolic test equation show NP0 filters outperform the more complex known boundary filters. NP0 filters typically reduce the L∞ error in the boundary region below that of the interior where optimally superconvergent symmetric filters of the same support are applied. NP0 filtering can be implemented as forming linear combinations of the data with short rational weights. Exact derivatives of the convolved output are easy to compute. PMID:29081643

  19. The Gattini South Pole UV experiment

    Science.gov (United States)

    Moore, Anna M.; Ahmed, Sara; Ashley, Michael C. B.; Croner, Ernest; Delacroix, Alex; Ebihara, Yusuke; Fucik, Jason; Martin, D. Christopher; Velur, Viswa; Weatherwax, Allan

    2012-09-01

    The Gattini South Pole UV experiment (Gattini SPUV) was deployed to the South Pole dark sector in February 2010 and has recently completed a highly successful first season of winter time observations. The experiment has, for the first time ever, measured and categorized the optical night sky brightness at the very blue wavelengths. The experiment consists of a remotely operated 6” aperture custom designed telescope. The telescope feeds a blue sensitive imager with 4 degree field of view that contains a bank of 3 filters: SDSS g’, Bessel U and a custom “super U” filter specifically designed to probe the sky emission at wavelengths approaching the atmospheric cut-off. The filters are continually cycled with exposure times ranging from 30 to 300 seconds throughout the winter period. The telescope, in addition, feeds a 2 degree long slit VPH grating spectrograph with R~1000. The bandwidth is 350-450nm. The spectra are recorded simultaneously with the imager exposures. The experiment is designed for low temperature Antarctic operation and resides on the roof of the MAPO building in the South Pole Antarctic sector. The primary science goals are to categorize the Antarctic winter-time sky background at the very bluest of wavelengths as a pathfinder for the Antarctic Cosmic Web Imager. We present a technical overview of the experiment and results from the first winter season.

  20. uv preilluminated gas switches

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, L.P.; Orham, E.L.; Stowers, I.F.; Braucht, J.R.

    1980-06-03

    We have designed, built, and characterized uv preilluminated gas switches for a trigger circuit and a low inductance discharge circuit. These switches have been incorporated into a 54 x 76 x 150 cm pulser module to produce a 1 Ma output current rising at 5 x 10/sup 12/ amps/sec with 1 ns jitter. Twenty such modules will be used on the Nova Inertial Confinement Fusion Laser System for plasma retropulse shutters.

  1. UV curable materials development

    Energy Technology Data Exchange (ETDEWEB)

    Parker, B.G.

    1996-12-01

    Adhesives, coatings, and inks were selected for evaluation based on literature search and possible production applications. A differential photocalorimeter was used to measure degree of cure and allow prediction of optimum processing conditions. UV cure equipment were characterized and the ability to size equipment to specific materials cure needs established. Adhesion tests procedures were developed for the adhesives and solvent resistance testing procedures developed for the coatings and inks.

  2. uv preilluminated gas switches

    International Nuclear Information System (INIS)

    Bradley, L.P.; Orham, E.L.; Stowers, I.F.; Braucht, J.R.

    1980-01-01

    We have designed, built, and characterized uv preilluminated gas switches for a trigger circuit and a low inductance discharge circuit. These switches have been incorporated into a 54 x 76 x 150 cm pulser module to produce a 1 Ma output current rising at 5 x 10 12 amps/sec with 1 ns jitter. Twenty such modules will be used on the Nova Inertial Confinement Fusion Laser System for plasma retropulse shutters

  3. Filter material charging apparatus for filter assembly for radioactive contaminants

    International Nuclear Information System (INIS)

    Goldsmith, J.M.; O'Nan, A. Jr.

    1977-01-01

    A filter charging apparatus for a filter assembly is described. The filter assembly includes a housing with at least one filter bed therein and the filter charging apparatus for adding filter material to the filter assembly includes a tank with an opening therein, the tank opening being disposed in flow communication with opposed first and second conduit means, the first conduit means being in flow communication with the filter assembly housing and the second conduit means being in flow communication with a blower means. Upon activation of the blower means, the blower means pneumatically conveys the filter material from the tank to the filter housing

  4. Light Conversion and Scattering in UV Protective Textiles

    Directory of Open Access Journals (Sweden)

    Grancarić Ana Marija

    2014-12-01

    Full Text Available The primary cause of skin cancer is believed to be a long exposure to solar ultraviolet radiation (UV-R crossed with the amount of skin pigmentation in the population. It is believed that in childhood and adolescence 80% of UV-R gets absorbed, whilst in the remaining 20% gets absorbed later in the lifetime. This suggests that proper and early photoprotection may reduce the risk of subsequent occurrence of skin cancer. Textile and clothing are the most suitable interface between environment and human body. It can show UV protection, but in most cases it does not provide full sun screening properties. UV protection ability highly depends on large number of factors such as type of fibre, fabric surface and construction, type and concentration of dyestuff, fluorescent whitening agent (FWA, UV-B protective agents, as well as nanoparticles, if applied. Based on electronically excited state by energy of UV-R (usually 340-370 nm, the molecules of FWAs show the phenomenon of fluorescence giving to white textiles high whiteness of outstanding brightness by reemitting the energy at the blue region (typically 420-470 nm of the spectrum. By absorbing UV-A radiation, optical brightened fabrics transform this radiation into blue fluorescence, which leads to better UV protection. Natural zeolites are rock-forming, microporous silicate minerals. Applied as nanoparticles to textile surface, it scatters the UV-R resulting in lower UV-A and UV-B transmission. If applied with other UV absorbing agents, e.g. FWAs, synergistic effect occurs. Silicones are inert, synthetic compounds with a variety of forms and uses. It provides a unique soft touch, is very resistant to washing and improves the property of fabric to protect against UV radiation. Therefore, the UV protective properties of cotton fabric achieved by light conversion and scattering was researched in this paper. For that purpose, the stilbene-derived FWAs were applied on cotton fabric in wide concentration

  5. Reproductive, morphological, and phytochemical responses of Arabidopsis thaliana ecotypes to enhanced UV-B radiation

    Energy Technology Data Exchange (ETDEWEB)

    Trumbull, V.L.; McCloud, E.S.; Paige, K.N. (Univ. of Illinois, Urbana, IL (United States))

    1994-06-01

    Two ecotypes of Arabidopsis thaliana, collected from Libya and Norway, were grown in the greenhouse under. UV-B doses of 0 and 10.5 kJ m[sup [minus]2] UV-B[sub BE]. The high UV-B dose simulated midsummer ambient conditions over Libya and a 40% reduction in stratospheric ozone over Norway. The Libyan ectotype, which originated from latitudes where solar UV-B is high, showed no UV-B induced damage to plant growth. However the Norwegian ecotype, which originated from latitudes where solar UV-B is low, showed a significant reduction in plant height, inflorescence weight, and rosette weight in response to enhanced UV-B. Although fruit and seed number for both ecotypes were unaffected by enhanced UV-B radiation the germination success of the seeds harvested from the irradiated Norwegian plants were significantly reduced. The two ecotypes also differed with respect to their accumulation of kaempferol, a putative UV-B protective filter. The Libyan ecotype increased kaempferol concentration by 38% over the 0 kJ treatment whereas the Norwegian ecotype increased by only 15%. These data suggest that, for these ecotypes, variation in UV-B sensitivity may be explained by the differential induction of UV-absorbing leaf pigments.

  6. The diffuse ensemble filter

    Directory of Open Access Journals (Sweden)

    X. Yang

    2009-07-01

    Full Text Available A new class of ensemble filters, called the Diffuse Ensemble Filter (DEnF, is proposed in this paper. The DEnF assumes that the forecast errors orthogonal to the first guess ensemble are uncorrelated with the latter ensemble and have infinite variance. The assumption of infinite variance corresponds to the limit of "complete lack of knowledge" and differs dramatically from the implicit assumption made in most other ensemble filters, which is that the forecast errors orthogonal to the first guess ensemble have vanishing errors. The DEnF is independent of the detailed covariances assumed in the space orthogonal to the ensemble space, and reduces to conventional ensemble square root filters when the number of ensembles exceeds the model dimension. The DEnF is well defined only in data rich regimes and involves the inversion of relatively large matrices, although this barrier might be circumvented by variational methods. Two algorithms for solving the DEnF, namely the Diffuse Ensemble Kalman Filter (DEnKF and the Diffuse Ensemble Transform Kalman Filter (DETKF, are proposed and found to give comparable results. These filters generally converge to the traditional EnKF and ETKF, respectively, when the ensemble size exceeds the model dimension. Numerical experiments demonstrate that the DEnF eliminates filter collapse, which occurs in ensemble Kalman filters for small ensemble sizes. Also, the use of the DEnF to initialize a conventional square root filter dramatically accelerates the spin-up time for convergence. However, in a perfect model scenario, the DEnF produces larger errors than ensemble square root filters that have covariance localization and inflation. For imperfect forecast models, the DEnF produces smaller errors than the ensemble square root filter with inflation. These experiments suggest that the DEnF has some advantages relative to the ensemble square root filters in the regime of small ensemble size, imperfect model, and copious

  7. Maternal inhalation of surface-coated nanosized titanium dioxide (UV-Titan) in C57BL/6 mice

    DEFF Research Database (Denmark)

    Jackson, Petra; Halappanavar, Sabina; Hougaard, Karin Sorig

    2013-01-01

    We investigated effects of maternal pulmonary exposure to titanium dioxide (UV-Titan) on prenatally exposed offspring. Time-mated mice (C57BL/6BomTac) were inhalation exposed (1 h/day to 42 mg UV-Titan/m(3) aerosolised powder or filtered air) during gestation days (GDs) 8-18. We evaluated DNA...

  8. Modelling object typicality in description logics

    CSIR Research Space (South Africa)

    Britz, K

    2009-12-01

    Full Text Available The authors present a semantic model of typicality of concept members in description logics (DLs) that accords well with a binary, globalist cognitive model of class membership and typicality. The authors define a general preferential semantic...

  9. Polymer filters for ultraviolet-excited integrated fluorescence sensing

    Science.gov (United States)

    Dandin, Marc; Abshire, Pamela; Smela, Elisabeth

    2012-09-01

    Optical filters for blocking ultraviolet (UV) light were fabricated by doping various polymer hosts with a UV absorbing chromophore. The polymers were polydimethylsiloxane (PDMS), a silicone elastomer frequently used in microfluidics, SU-8, a photopatternable epoxy, and Humiseal 1B66, an acrylic coating used for moisture protection of integrated circuits. The chromophore was 2-(2‧-hydroxy-5‧-methylphenyl) benzotriazole (BTA), which has a high extinction coefficient between 300 nm and 400 nm. We demonstrate filters 5 µm thick that exhibit high ultraviolet rejection (nearly -40 dB at 342 nm) yet pass visible light (near 0 dB above 400 nm), making them ideal for ultraviolet-excited fluorescence sensing within microsystems. The absorbance of the BTA depended on the host polymer. These filters are promising for integrated fluorescence spectroscopy in bioanalytical platforms because they can be patterned by dry etching, molding or exposure to ultraviolet light.

  10. Polymer filters for ultraviolet-excited integrated fluorescence sensing

    International Nuclear Information System (INIS)

    Dandin, Marc; Abshire, Pamela; Smela, Elisabeth

    2012-01-01

    Optical filters for blocking ultraviolet (UV) light were fabricated by doping various polymer hosts with a UV absorbing chromophore. The polymers were polydimethylsiloxane (PDMS), a silicone elastomer frequently used in microfluidics, SU-8, a photopatternable epoxy, and Humiseal 1B66, an acrylic coating used for moisture protection of integrated circuits. The chromophore was 2-(2′-hydroxy-5′-methylphenyl) benzotriazole (BTA), which has a high extinction coefficient between 300 nm and 400 nm. We demonstrate filters 5 µm thick that exhibit high ultraviolet rejection (nearly −40 dB at 342 nm) yet pass visible light (near 0 dB above 400 nm), making them ideal for ultraviolet-excited fluorescence sensing within microsystems. The absorbance of the BTA depended on the host polymer. These filters are promising for integrated fluorescence spectroscopy in bioanalytical platforms because they can be patterned by dry etching, molding or exposure to ultraviolet light. (paper)

  11. On typical properties of Hilbert space operators

    NARCIS (Netherlands)

    Eisner, T.; Mátrai, T.

    2013-01-01

    We study the typical behavior of bounded linear operators on infinite-dimensional complex separable Hilbert spaces in the norm, strong-star, strong, weak polynomial and weak topologies. In particular, we investigate typical spectral properties, the problem of unitary equivalence of typical

  12. UV Radiation and the Skin

    Science.gov (United States)

    D’Orazio, John; Jarrett, Stuart; Amaro-Ortiz, Alexandra; Scott, Timothy

    2013-01-01

    UV radiation (UV) is classified as a “complete carcinogen” because it is both a mutagen and a non-specific damaging agent and has properties of both a tumor initiator and a tumor promoter. In environmental abundance, UV is the most important modifiable risk factor for skin cancer and many other environmentally-influenced skin disorders. However, UV also benefits human health by mediating natural synthesis of vitamin D and endorphins in the skin, therefore UV has complex and mixed effects on human health. Nonetheless, excessive exposure to UV carries profound health risks, including atrophy, pigmentary changes, wrinkling and malignancy. UV is epidemiologically and molecularly linked to the three most common types of skin cancer, basal cell carcinoma, squamous cell carcinoma and malignant melanoma, which together affect more than a million Americans annually. Genetic factors also influence risk of UV-mediated skin disease. Polymorphisms of the melanocortin 1 receptor (MC1R) gene, in particular, correlate with fairness of skin, UV sensitivity, and enhanced cancer risk. We are interested in developing UV-protective approaches based on a detailed understanding of molecular events that occur after UV exposure, focusing particularly on epidermal melanization and the role of the MC1R in genome maintenance. PMID:23749111

  13. UV Radiation and the Skin

    Directory of Open Access Journals (Sweden)

    Timothy Scott

    2013-06-01

    Full Text Available UV radiation (UV is classified as a “complete carcinogen” because it is both a mutagen and a non-specific damaging agent and has properties of both a tumor initiator and a tumor promoter. In environmental abundance, UV is the most important modifiable risk factor for skin cancer and many other environmentally-influenced skin disorders. However, UV also benefits human health by mediating natural synthesis of vitamin D and endorphins in the skin, therefore UV has complex and mixed effects on human health. Nonetheless, excessive exposure to UV carries profound health risks, including atrophy, pigmentary changes, wrinkling and malignancy. UV is epidemiologically and molecularly linked to the three most common types of skin cancer, basal cell carcinoma, squamous cell carcinoma and malignant melanoma, which together affect more than a million Americans annually. Genetic factors also influence risk of UV-mediated skin disease. Polymorphisms of the melanocortin 1 receptor (MC1R gene, in particular, correlate with fairness of skin, UV sensitivity, and enhanced cancer risk. We are interested in developing UV-protective approaches based on a detailed understanding of molecular events that occur after UV exposure, focusing particularly on epidermal melanization and the role of the MC1R in genome maintenance.

  14. Hybrid Filter Membrane

    Science.gov (United States)

    Laicer, Castro; Rasimick, Brian; Green, Zachary

    2012-01-01

    Cabin environmental control is an important issue for a successful Moon mission. Due to the unique environment of the Moon, lunar dust control is one of the main problems that significantly diminishes the air quality inside spacecraft cabins. Therefore, this innovation was motivated by NASA s need to minimize the negative health impact that air-suspended lunar dust particles have on astronauts in spacecraft cabins. It is based on fabrication of a hybrid filter comprising nanofiber nonwoven layers coated on porous polymer membranes with uniform cylindrical pores. This design results in a high-efficiency gas particulate filter with low pressure drop and the ability to be easily regenerated to restore filtration performance. A hybrid filter was developed consisting of a porous membrane with uniform, micron-sized, cylindrical pore channels coated with a thin nanofiber layer. Compared to conventional filter media such as a high-efficiency particulate air (HEPA) filter, this filter is designed to provide high particle efficiency, low pressure drop, and the ability to be regenerated. These membranes have well-defined micron-sized pores and can be used independently as air filters with discreet particle size cut-off, or coated with nanofiber layers for filtration of ultrafine nanoscale particles. The filter consists of a thin design intended to facilitate filter regeneration by localized air pulsing. The two main features of this invention are the concept of combining a micro-engineered straight-pore membrane with nanofibers. The micro-engineered straight pore membrane can be prepared with extremely high precision. Because the resulting membrane pores are straight and not tortuous like those found in conventional filters, the pressure drop across the filter is significantly reduced. The nanofiber layer is applied as a very thin coating to enhance filtration efficiency for fine nanoscale particles. Additionally, the thin nanofiber coating is designed to promote capture of

  15. Variational Bayesian Filtering

    Czech Academy of Sciences Publication Activity Database

    Šmídl, Václav; Quinn, A.

    2008-01-01

    Roč. 56, č. 10 (2008), s. 5020-5030 ISSN 1053-587X R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : Bayesian filtering * particle filtering * Variational Bayes Subject RIV: BC - Control Systems Theory Impact factor: 2.335, year: 2008 http://library.utia.cas.cz/separaty/2008/AS/smidl-variational bayesian filtering.pdf

  16. The TROPOMI surface UV algorithm

    Science.gov (United States)

    Lindfors, Anders V.; Kujanpää, Jukka; Kalakoski, Niilo; Heikkilä, Anu; Lakkala, Kaisa; Mielonen, Tero; Sneep, Maarten; Krotkov, Nickolay A.; Arola, Antti; Tamminen, Johanna

    2018-02-01

    The TROPOspheric Monitoring Instrument (TROPOMI) is the only payload of the Sentinel-5 Precursor (S5P), which is a polar-orbiting satellite mission of the European Space Agency (ESA). TROPOMI is a nadir-viewing spectrometer measuring in the ultraviolet, visible, near-infrared, and the shortwave infrared that provides near-global daily coverage. Among other things, TROPOMI measurements will be used for calculating the UV radiation reaching the Earth's surface. Thus, the TROPOMI surface UV product will contribute to the monitoring of UV radiation by providing daily information on the prevailing UV conditions over the globe. The TROPOMI UV algorithm builds on the heritage of the Ozone Monitoring Instrument (OMI) and the Satellite Application Facility for Atmospheric Composition and UV Radiation (AC SAF) algorithms. This paper provides a description of the algorithm that will be used for estimating surface UV radiation from TROPOMI observations. The TROPOMI surface UV product includes the following UV quantities: the UV irradiance at 305, 310, 324, and 380 nm; the erythemally weighted UV; and the vitamin-D weighted UV. Each of these are available as (i) daily dose or daily accumulated irradiance, (ii) overpass dose rate or irradiance, and (iii) local noon dose rate or irradiance. In addition, all quantities are available corresponding to actual cloud conditions and as clear-sky values, which otherwise correspond to the same conditions but assume a cloud-free atmosphere. This yields 36 UV parameters altogether. The TROPOMI UV algorithm has been tested using input based on OMI and the Global Ozone Monitoring Experiment-2 (GOME-2) satellite measurements. These preliminary results indicate that the algorithm is functioning according to expectations.

  17. The TROPOMI surface UV algorithm

    Directory of Open Access Journals (Sweden)

    A. V. Lindfors

    2018-02-01

    Full Text Available The TROPOspheric Monitoring Instrument (TROPOMI is the only payload of the Sentinel-5 Precursor (S5P, which is a polar-orbiting satellite mission of the European Space Agency (ESA. TROPOMI is a nadir-viewing spectrometer measuring in the ultraviolet, visible, near-infrared, and the shortwave infrared that provides near-global daily coverage. Among other things, TROPOMI measurements will be used for calculating the UV radiation reaching the Earth's surface. Thus, the TROPOMI surface UV product will contribute to the monitoring of UV radiation by providing daily information on the prevailing UV conditions over the globe. The TROPOMI UV algorithm builds on the heritage of the Ozone Monitoring Instrument (OMI and the Satellite Application Facility for Atmospheric Composition and UV Radiation (AC SAF algorithms. This paper provides a description of the algorithm that will be used for estimating surface UV radiation from TROPOMI observations. The TROPOMI surface UV product includes the following UV quantities: the UV irradiance at 305, 310, 324, and 380 nm; the erythemally weighted UV; and the vitamin-D weighted UV. Each of these are available as (i daily dose or daily accumulated irradiance, (ii overpass dose rate or irradiance, and (iii local noon dose rate or irradiance. In addition, all quantities are available corresponding to actual cloud conditions and as clear-sky values, which otherwise correspond to the same conditions but assume a cloud-free atmosphere. This yields 36 UV parameters altogether. The TROPOMI UV algorithm has been tested using input based on OMI and the Global Ozone Monitoring Experiment-2 (GOME-2 satellite measurements. These preliminary results indicate that the algorithm is functioning according to expectations.

  18. Nanofiber Filters Eliminate Contaminants

    Science.gov (United States)

    2009-01-01

    With support from Phase I and II SBIR funding from Johnson Space Center, Argonide Corporation of Sanford, Florida tested and developed its proprietary nanofiber water filter media. Capable of removing more than 99.99 percent of dangerous particles like bacteria, viruses, and parasites, the media was incorporated into the company's commercial NanoCeram water filter, an inductee into the Space Foundation's Space Technology Hall of Fame. In addition to its drinking water filters, Argonide now produces large-scale nanofiber filters used as part of the reverse osmosis process for industrial water purification.

  19. Independent task Fourier filters

    Science.gov (United States)

    Caulfield, H. John

    2001-11-01

    Since the early 1960s, a major part of optical computing systems has been Fourier pattern recognition, which takes advantage of high speed filter changes to enable powerful nonlinear discrimination in `real time.' Because filter has a task quite independent of the tasks of the other filters, they can be applied and evaluated in parallel or, in a simple approach I describe, in sequence very rapidly. Thus I use the name ITFF (independent task Fourier filter). These filters can also break very complex discrimination tasks into easily handled parts, so the wonderful space invariance properties of Fourier filtering need not be sacrificed to achieve high discrimination and good generalizability even for ultracomplex discrimination problems. The training procedure proceeds sequentially, as the task for a given filter is defined a posteriori by declaring it to be the discrimination of particular members of set A from all members of set B with sufficient margin. That is, we set the threshold to achieve the desired margin and note the A members discriminated by that threshold. Discriminating those A members from all members of B becomes the task of that filter. Those A members are then removed from the set A, so no other filter will be asked to perform that already accomplished task.

  20. Randomized Filtering Algorithms

    DEFF Research Database (Denmark)

    Katriel, Irit; Van Hentenryck, Pascal

    2008-01-01

    of AllDifferent and is generalization, the Global Cardinality Constraint. The first delayed filtering scheme is a Monte Carlo algorithm: its running time is superior, in the worst case, to that of enforcing are consistency after every domain event, while its filtering effectiveness is analyzed......Filtering every global constraint of a CPS to are consistency at every search step can be costly and solvers often compromise on either the level of consistency or the frequency at which are consistency is enforced. In this paper we propose two randomized filtering schemes for dense instances...

  1. Fabrication of TiO2/EP super-hydrophobic thin film on filter paper surface.

    Science.gov (United States)

    Gao, Zhengxin; Zhai, Xianglin; Liu, Feng; Zhang, Ming; Zang, Deli; Wang, Chengyu

    2015-09-05

    A composite filter paper with super-hydrophobicity was obtained by adhering micro/nano structure of amorphous titanium dioxide on the filter paper surface with modifying low surface energy material. By virtue of the coupling agent, which plays an important part in bonding amorphous titanium dioxide and epoxy resin, the structure of super-hydrophobic thin film on the filter paper surface is extremely stable. The microstructure of super-hydrophobic filter paper was characterized by scanning electron microscopy (SEM), the images showed that the as-prepared filter paper was covered with uniform amorphous titanium dioxide particles, generating a roughness structure on the filter paper surface. The super-hydrophobic performance of the filter paper was characterized by water contact angle measurements. The observations showed that the wettability of filter paper samples transformed from super-hydrophilicity to super-hydrophobicity with the water contact angle of 153 ± 1°. Some experiments were also designed to test the effect of water-oil separation and UV-resistant by the super-hydrophobic filter paper. The prepared super-hydrophobic filter paper worked efficiently and simply in water-oil separation as well as enduringly in anti-UV property after the experiments. This method offers an opportunity to the practical applications of the super-hydrophobic filter paper. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. A latent model for collaborative filtering

    DEFF Research Database (Denmark)

    Langseth, Helge; Nielsen, Thomas Dyhre

    Recommender systems based on collaborative filtering have received a great deal of interest over the last decade. Typically, these types of systems either take a user-centered or an item-centered approach when making recommendations, but by employing only one of these two perspectives we may unin...... than other collaborative filtering systems (evaluated on the MovieLens data set). Furthermore, the explicit representation of all users and items allows the model to e.g. make group-based recommendations balancing the preferences of the individual users....

  3. UV-VIS absorption spectroscopy: Lambert-Beer reloaded

    Science.gov (United States)

    Mäntele, Werner; Deniz, Erhan

    2017-02-01

    UV-VIS absorption spectroscopy is used in almost every spectroscopy laboratory for routine analysis or research. All spectroscopists rely on the Lambert-Beer Law but many of them are less aware of its limitations. This tutorial discusses typical problems in routine spectroscopy that come along with technical limitations or careless selection of experimental parameters. Simple rules are provided to avoid these problems.

  4. A robust nonlinear filter for image restoration.

    Science.gov (United States)

    Koivunen, V

    1995-01-01

    A class of nonlinear regression filters based on robust estimation theory is introduced. The goal of the filtering is to recover a high-quality image from degraded observations. Models for desired image structures and contaminating processes are employed, but deviations from strict assumptions are allowed since the assumptions on signal and noise are typically only approximately true. The robustness of filters is usually addressed only in a distributional sense, i.e., the actual error distribution deviates from the nominal one. In this paper, the robustness is considered in a broad sense since the outliers may also be due to inappropriate signal model, or there may be more than one statistical population present in the processing window, causing biased estimates. Two filtering algorithms minimizing a least trimmed squares criterion are provided. The design of the filters is simple since no scale parameters or context-dependent threshold values are required. Experimental results using both real and simulated data are presented. The filters effectively attenuate both impulsive and nonimpulsive noise while recovering the signal structure and preserving interesting details.

  5. Life and the solar UV environment on early Earth

    Science.gov (United States)

    Bérces, A.; Kovács, G.; Lammer, H.; Kolb, Ch.; Rontó, Gy.

    Studies of the solar UV environment on Earth 2 0 Gyr to 3 8 Gyr ago suggest that the terrestrial atmosphere was essentially anoxic resulting in an ozone column abundance insufficient for protecting the planetary surface in the UV-B 280 nm - 315 nm and the UV-C 200 nm - 280 nm ranges Since short wavelength solar UV radiation in the UV-B and UV-C range penetrated through the atmosphere to the unprotected early Earth s surface associated biological consequences may be expected We discuss experimental data obtained as follows Radiation sources applied were low pressure Mercury lamp and Xenon 2 kW lamp the wavelength were adjusted by interference filters 200BP10 210BP10 220BP10 230BP10 240BP10 250BP10 260BP10 270BP10 280BP10 290BP10 300BP10 310BP10 320BP10 and the irradiances were measured by OL754 spectroradiometer The photo-reverse effect depends highly on the wavelength of the exposed radiation Shorter wavelength UV radiation of about 200 nm is strongly effective in monomerization while the longer wavelengths prefer the dimerisation In case of polychromatic light like in space or on a planetary surface which is unprotected by an ozone layer the two processes run parallel We could demonstrate experimentally for the case of a uracil thin-layer that the photo-reaction process of the nucleotides can be both dimerization and the reverse process monomerization These results are important for the study of solar UV effects on organisms in the early terrestrial environment as well as for the search for life on Mars since we can show that biological

  6. Comparative study of low-pass filter and phase-locked loop type speed filters for sensorless control of AC drives

    DEFF Research Database (Denmark)

    Wang, Dong; Lu, Kaiyuan; Rasmussen, Peter Omand

    2017-01-01

    filters exhibit almost linear relationship between the cutoff frequency of the PLL filter and its proportional-integral (PI) gains, which can ease the realization of speed filters with adaptive cutoff frequency for improving the speed transient performance. The proposed filters are verified experimentally......High quality speed information is one of the key issues in machine sensorless drives, which often requires proper filtering of the estimated speed. This paper comparatively studies typical low-pass filters (LPF) and phase-locked loop (PLL) type filters with respect to ramp speed reference tracking...... and steady-state performances, as well as the achievement of adaptive cutoff frequency control. An improved LPF-based filter structure with no ramping and steady-state errors caused by filter parameter quantization effects is proposed, which is suitable for applying LPF for sensorless drives of AC machines...

  7. Multilevel ensemble Kalman filter

    KAUST Repository

    Chernov, Alexey

    2016-01-06

    This work embeds a multilevel Monte Carlo (MLMC) sampling strategy into the Monte Carlo step of the ensemble Kalman filter (EnKF). In terms of computational cost vs. approximation error the asymptotic performance of the multilevel ensemble Kalman filter (MLEnKF) is superior to the EnKF s.

  8. Interdigital filter design

    CSIR Research Space (South Africa)

    Du Plessis, WP

    2009-10-01

    Full Text Available A new synthesis procedure for interdigital filters with shorted-pin feeds is developed by relating the coupling factors and external Qs to the physical structure of the filter. This new procedure is easily understood and applied, extremely flexible...

  9. Exclusion of solar UV radiation improves photosynthetic performance and yield of wheat varieties.

    Science.gov (United States)

    Kataria, Sunita; Guruprasad, K N

    2015-12-01

    Field studies were conducted to determine the potential for alterations in photosynthetic performance and grain yield of four wheat (Triticum aestivum) varieties of India- Vidisha, Purna, Swarna and Naveen Chandausi by ambient ultraviolet radiation (UV). The plants were grown in specially designed UV exclusion chambers, wrapped with filters that excluded UV-B (solar UV exclusion increased the leaf mass per area ratio, leaf weight ratio and chlorophylls per unit area of flag leaves in all the four varieties of wheat. Polyphasic chlorophyll a fluorescence transients from the flag leaves of UV excluded wheat plants gave a higher fluorescence yield. Exclusion of solar UV significantly enhanced photosynthetic performance as a consequence of increased efficiency of PS II, performance index (PIABS) and rate of photosynthesis in the flag leaves of wheat varieties along with a remarkable increase in carbonic anhydrase, Rubisco and nitrate reductase activities. This additional fixation of carbon and nitrogen by exclusion of UV was channelized towards the improvement in grain yield of wheat varieties as there was a decrease in the UV-B absorbing substances and an increase in soluble protein content in flag leaves of all the four varieties of wheat. The magnitude of response for UV exclusion for all the measured parameters was higher in two varieties of wheat Vidisha and Purna as compared to Swarna and Naveen Chandausi. Cumulative stress response index (CSRI) for each variety was developed from the cumulative sum of physiological and yield parameters such as leaf mass area ratio of flag leaf, total chlorophyll content, performance index at absorption basis, rate of photosynthesis and grain yield. All the varieties had a negative CSRI, demonstrating a negative impact of ambient UV radiation. Naveen Chandausi and Swarna are less sensitive to ambient UV radiation; Vidisha is more sensitive to both UV-A and UV-B and Purna is more sensitive to ambient UV-B radiation. Copyright

  10. China exported birefringent filter

    Science.gov (United States)

    Li, Ting; Mao, Weijun; Lu, Haitian; Zhu, Yong

    2001-09-01

    Since 1960s, Nanjing Astronomical Instrument Research center of CAS have been developing the birefringent filters for China solar observatories, the most famous one in the world is the 0.15Å(0.12Å)/5324Å(4861Å) filter for the 35cm Solar Magnetic Field Telescope of the Huairou Solar Station of Beijing Observatory. The big success in the field of Lyot filter has been proved by the international solar physics circle, since 1988, Japanese and Korean astronomers have been paying a lot of orders for making Lyot filters from China, up to now we have exported 11 sets of such sophisticated optical instruments, they have been used for routine solar observations in the observatories and planetaria in the two countries. We also begin to repair old Lyot filters made by Germany and France from foreign countries, as India and Germany.

  11. Sub-micron filter

    Science.gov (United States)

    Tepper, Frederick [Sanford, FL; Kaledin, Leonid [Port Orange, FL

    2009-10-13

    Aluminum hydroxide fibers approximately 2 nanometers in diameter and with surface areas ranging from 200 to 650 m.sup.2/g have been found to be highly electropositive. When dispersed in water they are able to attach to and retain electronegative particles. When combined into a composite filter with other fibers or particles they can filter bacteria and nano size particulates such as viruses and colloidal particles at high flux through the filter. Such filters can be used for purification and sterilization of water, biological, medical and pharmaceutical fluids, and as a collector/concentrator for detection and assay of microbes and viruses. The alumina fibers are also capable of filtering sub-micron inorganic and metallic particles to produce ultra pure water. The fibers are suitable as a substrate for growth of cells. Macromolecules such as proteins may be separated from each other based on their electronegative charges.

  12. Filter cake breaker systems

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Marcelo H.F. [Poland Quimica Ltda., Duque de Caxias, RJ (Brazil)

    2004-07-01

    Drilling fluids filter cakes are based on a combination of properly graded dispersed particles and polysaccharide polymers. High efficiency filter cakes are formed by these combination , and their formation on wellbore walls during the drilling process has, among other roles, the task of protecting the formation from instantaneous or accumulative invasion of drilling fluid filtrate, granting stability to well and production zones. Filter cake minimizes contact between drilling fluid filtrate and water, hydrocarbons and clay existent in formations. The uniform removal of the filter cake from the entire interval is a critical factor of the completion process. The main methods used to breaking filter cake are classified into two groups, external or internal, according to their removal mechanism. The aim of this work is the presentation of these mechanisms as well their efficiency. (author)

  13. Performance of mixed conducting electrochemical filters for YSZ oxygen sensors

    Energy Technology Data Exchange (ETDEWEB)

    Costa, A.D.S. [ESTGAD, Caldas da Rainha (Portugal). Inst. Politecnico Leiria; Labrincha, J.A.; Marques, F.M.B. [Dept. Eng. Ceramica e do Vidro, Univ. de Aveiro (Portugal)

    1997-12-31

    Oxygen sensors based on yttria stabilized zirconia (YSZ), used in some industrial applications, can be protected by dense filters with high electrochemical permeability to ensure longer lifetime. However, the performance of such sensors can be affected by the surface properties of the filter. This work reports on the relevance of surface processes on the overall oxygen transport rate across the filter. Different materials (filter and electrodes) were tested for this purpose, involving LaCoO{sub 3} (LC) and Ce{sub 0.8}Gd{sub 0.2}O{sub 2} (GCO) single phase or composite filters (combination of both phases), and different deposited electrode materials ((La,Sr)MnO{sub 3} and Pt). For a typical combination involving an ionic conductor as filter (GCO) and electronic conductors as electrodes, the cathodic process seems to be more relevant than the anodic one in determining the protected sensor performance. (orig.) 7 refs.

  14. CUVE - Cubesat UV Experiment: Unveil Venus' UV Absorber with Cubesat UV Mapping Spectrometer

    Science.gov (United States)

    Cottini, V.; Aslam, S.; D'Aversa, E.; Glaze, L.; Gorius, N.; Hewagama, T.; Ignatiev, N.; Piccioni, G.

    2017-09-01

    Our Venus mission concept Cubesat UV Experiment (CUVE) is one of ten proposals selected for funding by the NASA PSDS3 Program - Planetary Science Deep Space SmallSat Studies. CUVE concept is to insert a CubeSat spacecraft into a Venusian orbit and perform remote sensing of the UV spectral region using a high spectral resolution point spectrometer to resolve UV molecular bands, observe nightglow, and characterize the unidentified main UV absorber. The UV spectrometer is complemented by an imaging UV camera with multiple bands in the UV absorber main band range for contextual imaging. CUVE Science Objectives are: the nature of the "Unknown" UV-absorber; the abundances and distributions of SO2 and SO at and above Venus's cloud tops and their correlation with the UV absorber; the atmospheric dynamics at the cloud tops, structure of upper clouds and wind measurements from cloud-tracking; the nightglow emissions: NO, CO, O2. This mission will therefore be an excellent platform to study Venus' cloud top atmospheric properties where the UV absorption drives the planet's energy balance. CUVE would complement past, current and future Venus missions with conventional spacecraft, and address critical science questions cost effectively.

  15. RESEARCH OF UV-PROTECTIVE ACTIVITY OF FERULIC ACID AS PART OF OINTMENT COMPOSITIONS WITH DIFFERENT PHYSICAL AND CHEMICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    I. L. Abisalova

    2014-01-01

    Full Text Available Cosmetics with the ability to neutralize harmful influence of ultraviolet rays on skin are quite in demand. UV filters in creams composition are divided into two groups: physical and chemical. Antioxidants are used as chemical UV filters. The article presents the results of ferulic acid testing as UV filter in ointment bases with lipophile, hydrophile and lipophilic and hydrophilic properties. The dependence of ferulic acid efficiency from the base type where it was applied was established. The results received are correlated with data about release rate of ferulic acid received in vitro. Ointment bases with such emulsifiers as cetyl alcohol, base emulsifier and Olivem 1000 have the most signified UV protective effect of ferulic acid.

  16. A Comb Filter Design Method Using Linear Phase FIR Filter

    Science.gov (United States)

    Sugiura, Yosuke; Kawamura, Arata; Iiguni, Youji

    This paper proposes a comb filter design method which utilizes two linear phase FIR filters for flexibly adjusting the comb filter's frequency response. The first FIR filter is used to individually adjust the notch gains, which denote the local minimum gains of the comb filter's frequency response. The second FIR filter is used to design the elimination bandwidths for individual notch gains. We also derive an efficient comb filter by incorporating these two FIR filters with an all-pass filter which is used in a conventional comb filter to accurately align the nulls with the undesired harmonic frequencies. Several design examples of the derived comb filter show the effectiveness of the proposed comb filter design method.

  17. Detection of Harmonic Occurring using Kalman Filtering

    DEFF Research Database (Denmark)

    Hussain, Dil Muhammad Akbar; Shoro, Ghulam Mustafa; Imran, Raja Muhammed

    2014-01-01

    As long as the load to a power system is linear which has been the case before 80's, typically no harmonics are produced. However, the modern power electronic equipment for controlled power consumption produces harmonic disturbances, these devices/equipment possess nonlinear voltage/current chara...... using Kalman filter. This may be very useful for example to quickly switching on certain filters based on the harmonic present. We are using a unique technique to detect the occurrence of harmonics......./current characteristic. These harmonics are not to be allowed to grow beyond a certain limit to avoid any grave consequence to the customer’s main supply. Filters can be implemented at the power source or utility location to eliminate these harmonics. In this paper we detect the instance at which these harmonics occur...

  18. Flat zones filtering, connected operators, and filters by reconstruction.

    Science.gov (United States)

    Salembier, P; Serra, J

    1995-01-01

    This correspondence deals with the notion of connected operators. Starting from the definition for operator acting on sets, it is shown how to extend it to operators acting on function. Typically, a connected operator acting on a function is a transformation that enlarges the partition of the space created by the flat zones of the functions. It is shown that from any connected operator acting on sets, one can construct a connected operator for functions (however, it is not the unique way of generating connected operators for functions). Moreover, the concept of pyramid is introduced in a formal way. It is shown that, if a pyramid is based on connected operators, the flat zones of the functions increase with the level of the pyramid. In other words, the flat zones are nested. Filters by reconstruction are defined and their main properties are presented. Finally, some examples of application of connected operators and use of flat zones are described.

  19. Improving the segmentation for weed recognition applications based on standard RGB cameras using optical filters

    DEFF Research Database (Denmark)

    Stigaard Laursen, Morten; Jørgensen, Rasmus Nyholm; Midtiby, Henrik

    -filter following a rectangular function. However the filter in place is selected for best mimicking the spectral sensitivity of the human vision, the cut-off is therefore neither sharp nor blocks completely. In this work we show that by replacing the IR filter with a more carefully selected IR filter matched....... This method utilizes that most vegetation reflects more green light than blue and red. As silicon based image sensors is also sensitive to near-infrared light a typical rgb-camera will have a filter in place to block the near-infrared light. When using excess green the ideal filter would be a sinc...

  20. Ion track filters in imaging X-ray astronomy

    Science.gov (United States)

    Mitrofanov, A. V.; Apel, P. Yu.

    2006-04-01

    The application of ion track filters as blocking cut-off filters for solar telescopes in imaging X-ray astronomy is presented. Ion track membranes (ITMs) of high-porosity constitute a randomly inhomogeneous medium with sub-micrometer or micrometer open pores which not only transmits X-ray or extreme ultra violet (EUV) radiation and blocks long-wavelength UV radiation, but also transfers a focused imaging pattern with high-quality for further registration by means of CCD or imaging detectors of other types. X-ray and EUV filters based on ITMs with cylindrical parallel pores were successfully used as detector filters in the solar X-ray telescopes designed and manufactured at the Lebedev Physical Institute of the Russian Academy of Sciences (LPI, Moscow).

  1. Fracture and embolization of a Celect inferior vena cava filter strut to the liver: A Case Report

    International Nuclear Information System (INIS)

    Kim, So Hee; Song, Yun Gyu

    2017-01-01

    Inferior vena cava (IVC) filters are typically used for prophylaxis against pulmonary embolism. A new version of the Günther Tulip filter, the Celect IVC filter was introduced in April 2007. To the best of our knowledge, there are no reports commenting on Celect IVC filter fracture and fragment embolization to liver. We report a case in which the strut of the Celect IVC filter embolized to the liver

  2. Fracture and embolization of a Celect inferior vena cava filter strut to the liver: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, So Hee; Song, Yun Gyu [Dept. of Radiology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon (Korea, Republic of)

    2017-07-15

    Inferior vena cava (IVC) filters are typically used for prophylaxis against pulmonary embolism. A new version of the Günther Tulip filter, the Celect IVC filter was introduced in April 2007. To the best of our knowledge, there are no reports commenting on Celect IVC filter fracture and fragment embolization to liver. We report a case in which the strut of the Celect IVC filter embolized to the liver.

  3. A Typical Verification Challenge for the GRID

    NARCIS (Netherlands)

    van de Pol, Jan Cornelis; Bal, H. E.; Brim, L.; Leucker, M.

    2008-01-01

    A typical verification challenge for the GRID community is presented. The concrete challenge is to implement a simple recursive algorithm for finding the strongly connected components in a graph. The graph is typically stored in the collective memory of a number of computers, so a distributed

  4. Ceramic fiber reinforced filter

    Science.gov (United States)

    Stinton, David P.; McLaughlin, Jerry C.; Lowden, Richard A.

    1991-01-01

    A filter for removing particulate matter from high temperature flowing fluids, and in particular gases, that is reinforced with ceramic fibers. The filter has a ceramic base fiber material in the form of a fabric, felt, paper of the like, with the refractory fibers thereof coated with a thin layer of a protective and bonding refractory applied by chemical vapor deposition techniques. This coating causes each fiber to be physically joined to adjoining fibers so as to prevent movement of the fibers during use and to increase the strength and toughness of the composite filter. Further, the coating can be selected to minimize any reactions between the constituents of the fluids and the fibers. A description is given of the formation of a composite filter using a felt preform of commercial silicon carbide fibers together with the coating of these fibers with pure silicon carbide. Filter efficiency approaching 100% has been demonstrated with these filters. The fiber base material is alternately made from aluminosilicate fibers, zirconia fibers and alumina fibers. Coating with Al.sub.2 O.sub.3 is also described. Advanced configurations for the composite filter are suggested.

  5. UV Lidar Receiver Analysis for Tropospheric Sensing of Ozone

    Science.gov (United States)

    Pliutau, Denis; DeYoung, Russell J.

    2013-01-01

    A simulation of a ground based Ultra-Violet Differential Absorption Lidar (UV-DIAL) receiver system was performed under realistic daytime conditions to understand how range and lidar performance can be improved for a given UV pulse laser energy. Calculations were also performed for an aerosol channel transmitting at 3 W. The lidar receiver simulation studies were optimized for the purpose of tropospheric ozone measurements. The transmitted lidar UV measurements were from 285 to 295 nm and the aerosol channel was 527-nm. The calculations are based on atmospheric transmission given by the HITRAN database and the Modern Era Retrospective Analysis for Research and Applications (MERRA) meteorological data. The aerosol attenuation is estimated using both the BACKSCAT 4.0 code as well as data collected during the CALIPSO mission. The lidar performance is estimated for both diffuseirradiance free cases corresponding to nighttime operation as well as the daytime diffuse scattered radiation component based on previously reported experimental data. This analysis presets calculations of the UV-DIAL receiver ozone and aerosol measurement range as a function of sky irradiance, filter bandwidth and laser transmitted UV and 527-nm energy

  6. Skin Cancer and UV Protection

    Directory of Open Access Journals (Sweden)

    Tarbuk Anita

    2016-03-01

    Full Text Available The incidence of skin cancer is increasing by epidemic proportions. Basal cell cancer remains the most common skin neoplasm, and simple excision is generally curative. On the other hand, aggressive local growth and metastasis are common features of malignant melanoma, which accounts for 75% of all deaths associated with skin cancer. The primary cause of skin cancer is long exposure to solar ultraviolet radiation (UV-R crossed with the amount of skin pigmentation and family genetics. It is believed that in childhood and adolescence, 80% of UV-R gets absorbed while in the remaining, 20 % gets absorbed later in the lifetime. This suggests that proper and early photoprotection may reduce the risk of subsequent occurrence of skin cancer. Reducing the exposure time to sunlight, using sunscreens and protective textiles are the three ways of UV protection. Most people think that all the clothing will protect them, but it does not provide full sun screening properties. Literature sources claim that only 1/3 of the spring and summer collections tested give off proper UV protection. This is very important during the summer months, when UV index is the highest. Fabric UV protection ability highly depends on large number of factors such as type of fiber, fabric surface, construction, porosity, density, moisture content, type and concentration of dyestuff, fluorescent whitening agents, UV-B protective agents (UV absorbers, as well as nanoparticles, if applied. For all of these reasons, in the present paper, the results of UV protecting ability according to AS/NZS 4399:1996 will be discussed to show that standard clothing materials are not always adequate to prevent effect of UV-R to the human skin; and to suggest the possibilities for its improvement for this purpose enhancing light conversion and scattering. Additionally, the discrepancy in UV protection was investigated in distilled water as well as Adriatic Sea water.

  7. Circuits and filters handbook

    CERN Document Server

    Chen, Wai-Kai

    2003-01-01

    A bestseller in its first edition, The Circuits and Filters Handbook has been thoroughly updated to provide the most current, most comprehensive information available in both the classical and emerging fields of circuits and filters, both analog and digital. This edition contains 29 new chapters, with significant additions in the areas of computer-aided design, circuit simulation, VLSI circuits, design automation, and active and digital filters. It will undoubtedly take its place as the engineer's first choice in looking for solutions to problems encountered in the design, analysis, and behavi

  8. Flight of a UV spectrophotometer aboard Galileo 2, the NASA Convair 990 aircraft

    Science.gov (United States)

    Sellers, B.; Hunderwadel, J. L.; Hanser, F. A.

    1976-01-01

    An ultraviolet interference-filter spectrophotometer (UVS) fabricated for aircraft-borne use on the DOT Climatic Impact Assessment Program (CIAP) has been successfully tested in a series of flights on the NASA Convair 990, Galileo II. UV flux data and the calculated total ozone above the flight path are reported for several of the flights. Good agreement is obtained with the total ozone as deducted by integration of an ozone sonde vertical profile obtained at Wallops Island, Virginia near the time of a CV-990 underpass. Possible advantages of use of the UVS in the NASA Global Atmospheric Sampling Program are discussed.

  9. Integrated optical devices for wavelength division multiplexing using PECVD and direct UV writing techniques

    DEFF Research Database (Denmark)

    Zauner, Dan; Leistiko, Otto

    1999-01-01

    way of adjusting center frequencies opt optical filters to a grid. The draw-back is that the components need to be temperature stabilized. UV trimming have ben used to permanently change the refractive index in selected areas of a device. In this way, a novel way of trimmin arrayed waveguide gratings...... channel waveguides are presented: a conventional method and direct UV writing. It is shown that an optimized three layer glass structure yields directly UV written waveguides with low insertion losses. Integrated optical structures have been designed and fabricated. The impact of process variations...

  10. Transcriptional activity of detoxification genes is altered by ultraviolet filters in Chironomus riparius.

    Science.gov (United States)

    Martínez-Guitarte, José-Luis

    2018-03-01

    Ultraviolet (UV) filters are compounds used to prevent the damage produced by UV radiation in personal care products, plastics, etc. They have been associated with endocrine disruption, showing anti-estrogen activity in vertebrates and altering the ecdysone pathway in invertebrates. Although they have attracted the attention of multiple research teams there is a lack of data about how animals activate detoxification systems, especially in invertebrates. Here, analysis of the effects of two UV filters, benzophenone-3 (BP3) and 4-methylbenzylidene camphor (4MBC), on the transcriptional activity of nine genes covering the three steps of the detoxification process has been performed. Four cytochrome P450 genes belonging to different members of this family, five GST genes, and the multidrug resistance protein 1 (MRP1) gene were studied by RT-PCR to analyze their transcriptional activity in fourth instar larvae exposed to the UV filters for 8 and 24h. The obtained results show a differential response with downregulation of the different Cyp450s tested by 4MBC while BP3 seems not to modify their expression. On the other hand, some of the GST genes were affected by one or other of the filters, showing a less homogenous response. Finally, MRP1 was activated by both filters but at different times. These results demonstrate for first time that UV filters alter the expression of genes involved in the different steps of the detoxification process and that they can be processed by phase I enzymes other than Cyp450s. They also suggest that UV filters affect biotransformation processes, compromising the ability of the individual to respond to chemical stress, so further research is needed to know the extent of the damage that they can produce in the resistance of the cell to chemicals. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Filter-Dense Multicolor Microscopy.

    Directory of Open Access Journals (Sweden)

    Siavash Kijani

    Full Text Available Immunofluorescence microscopy is a unique method to reveal the spatial location of proteins in tissues and cells. By combining antibodies that are labeled with different fluorochromes, the location of several proteins can simultaneously be visualized in one sample. However, because of the risk of bleed-through signals between fluorochromes, standard multicolor microscopy is restricted to a maximum of four fluorescence channels, including one for nuclei staining. This is not always enough to address common scientific questions. In particular, the use of a rapidly increasing number of marker proteins to classify functionally distinct cell populations and diseased tissues emphasizes the need for more complex multistainings. Hence, multicolor microscopy should ideally offer more channels to meet the current needs in biomedical science. Here we present an enhanced multi-fluorescence setup, which we call Filter-Dense Multicolor Microscopy (FDMM. FDMM is based on condensed filter sets that are more specific for each fluorochrome and allow a more economic use of the light spectrum. FDMM allows at least six independent fluorescence channels and can be applied to any standard fluorescence microscope without changing any operative procedures for the user. In the present study, we demonstrate an FDMM setup of six channels that includes the most commonly used fluorochromes for histology. We show that the FDMM setup is specific and robust, and we apply the technique on typical biological questions that require more than four fluorescence microscope channels.

  12. Combined impact of solar UV-B radiation and selenium treatment on respiratory potential in pumpkins (Cucurbita pepo L.)

    International Nuclear Information System (INIS)

    Germ, M.

    2005-01-01

    The effects of ambient and filtered solar UV-B radiation and of selenium treatment on respiratory potential measured by electron transport system (ETS) activity in pumpkins, Cucurbita pepo L. were studied. Measurements were conducted three times in the growth period. Solar UV-B radiation decreased ETS activity in plants, regardless selenium treatment. The results suggested that the solar UV-B radiation impaired flow of electrons in the respiratory chain. Selenium decreased ETS activity in plants exposed to solar UV-B radiation in the end of the vegetation period

  13. A novel and simple fabrication method of embedded SU-8 micro channels by direct UV lithography

    International Nuclear Information System (INIS)

    Fu, C; Hung, C; Huang, H

    2006-01-01

    In this paper, we presents a novel and simple method to fabricate embedded micro channels. The method based on different light absorption properties of the SU-8 thick photoresist under different incident UV wavelengths. The channel structures are defined by the ordinary I-line, while the cover layer is patterned by the deep UV. Because the deep UV is obtained directly on the same aligner with a set of filter mirrors, the embedded channel can be easily produced without other rare facilities. Besides, the relationship between the thickness of the top layer and the exposure dose of the deep UV has been measured by an ingeniously designed experiment. The specific thickness of the top layer of the embedded micro channel can then be secured by the specific deep-UV exposure dose. Further more, many meaningful mechanical structures have been realized by this method, the material property of the top layer are also measured

  14. Electrophoresis microchip with integrated waveguides for simultaneous native UV fluorescence and absorbance detection

    DEFF Research Database (Denmark)

    Ohlsson, Pelle Daniel; Sala, Olga Ordeig; Mogensen, Klaus Bo

    2009-01-01

    Simultaneous label-free detection of UV absorbance and native UV-excited fluorescence in an electrophoresis microchip is presented. UV transparent integrated waveguides launch light at a wavelength of 254 nm from a mercury lamp along the length of a 1-mm. long detection cell. Transmitted UV light...... lid and by choosing a PMT insensitive to the excitation light. This way, the need for a fluorescence filter is eliminated. Calibration curves were measured for serotonin, tryptophan, propranolol and acetaminophen, and separations of the four compounds were demonstrated by electrophoresis and MEKC. All...... compounds could be detected in the micromolar range by absorbance detection, but fluorescence detection improved detection limits for compounds displaying native UV fluorescence up to ten times. The simultaneous detection also proved useful for the identification of compounds with similar retention times...

  15. Enhancement of UV absorption behavior in Zn O-TiO{sub 2} composites

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Reinosa, J.; Leret, P.; Alvarez-Docio, C. M.; Campo, A. del; Fernandez, J. F.

    2016-05-01

    The ultraviolet -visible, UV-vis, absorption edge behaviour of semiconductor oxides as TiO{sub 2} and ZnO promotes their use as inorganic UV filters for sunscreens. In cosmetics, the use of nanoparticles is favoured because of their higher yield and lower whiteness. However, the particle size effect in the UV absorption is unclear. For this reason, the performances of nano and microsized TiO{sub 2} and ZnO are evaluated in both the UV-vis spectroscopy and the Sun Protection Factor, SPF, value. In order to cover the UV range completely by using inorganic filters a new composite is attempted by dry nano dispersion methodology in which TiO{sub 2} nanoparticles are dispersed onto ZnO microparticles. The new composite shows superior UV absorbing properties and ca. 60% SPF value due to a synergism between components that resulted in extended UV coverage and reduction of the total amount of nanoparticles required in the sunscreens. In addition, nanoparticles are effectively anchored onto microparticles avoiding the presence of free nanoparticles. (Author)

  16. Paul Rodgersi filter Kohilas

    Index Scriptorium Estoniae

    2000-01-01

    28. I Kohila keskkoolis kohaspetsiifiline skulptuur ja performance "Filter". Kooli 130. aastapäeva tähistava ettevõtmise eesotsas oli skulptor Paul Rodgers ja kaks viimase klassi noormeest ئ Marko Heinmäe, Hendrik Karm.

  17. Dust filter testing

    International Nuclear Information System (INIS)

    Dupoux, J.

    1975-01-01

    The composition of dust filters used in cleanup systems for radioactive gaseous effluents is described as well as the technical controls, especially efficiency measured by a soda fluorescein aerosol [fr

  18. Vena cava filter

    International Nuclear Information System (INIS)

    Helmberger, T.

    2007-01-01

    Fulminant pulmonary embolism is one of the major causes of death in the Western World. In most cases, deep leg and pelvic venous thrombosis are the cause. If an anticoagulant/thrombotic therapy is no longer possible or ineffective, a vena cava filter implant may be indicated if an embolism is threatening. Implantation of the filter is a simple and safe intervention. Nevertheless, it is necessary to take into consideration that the data base for determining the indications for this treatment are very limited. Currently, a reduction in the risk of thromboembolism with the use of filters of about 30%, of recurrences of almost 5% and fatal pulmonary embolism of 1% has been reported, with a risk of up to 20% of filter induced vena cava thrombosis. (orig.) [de

  19. Perspectives on Nonlinear Filtering

    KAUST Repository

    Law, Kody

    2015-01-07

    The solution to the problem of nonlinear filtering may be given either as an estimate of the signal (and ideally some measure of concentration), or as a full posterior distribution. Similarly, one may evaluate the fidelity of the filter either by its ability to track the signal or its proximity to the posterior filtering distribution. Hence, the field enjoys a lively symbiosis between probability and control theory, and there are plenty of applications which benefit from algorithmic advances, from signal processing, to econometrics, to large-scale ocean, atmosphere, and climate modeling. This talk will survey some recent theoretical results involving accurate signal tracking with noise-free (degenerate) dynamics in high-dimensions (infinite, in principle, but say d between 103 and 108 , depending on the size of your application and your computer), and high-fidelity approximations of the filtering distribution in low dimensions (say d between 1 and several 10s).

  20. Updating the OMERACT filter

    DEFF Research Database (Denmark)

    Tugwell, Peter; Boers, Maarten; D'Agostino, Maria-Antonietta

    2014-01-01

    OBJECTIVE: The Outcome Measures in Rheumatology (OMERACT) Filter provides guidelines for the development and validation of outcome measures for use in clinical research. The "Truth" section of the OMERACT Filter requires that criteria be met to demonstrate that the outcome instrument meets...... the criteria for content, face, and construct validity. METHODS: Discussion groups critically reviewed a variety of ways in which case studies of current OMERACT Working Groups complied with the Truth component of the Filter and what issues remained to be resolved. RESULTS: The case studies showed...... that there is broad agreement on criteria for meeting the Truth criteria through demonstration of content, face, and construct validity; however, several issues were identified that the Filter Working Group will need to address. CONCLUSION: These issues will require resolution to reach consensus on how Truth...

  1. HEPA air filter (image)

    Science.gov (United States)

    ... pet dander and other irritating allergens from the air. Along with other methods to reduce allergens, such ... controlling the amount of allergens circulating in the air. HEPA filters can be found in most air ...

  2. Study of UV cloud modification factors in Southern Patagonia

    Science.gov (United States)

    Wolfram, Elian A.; Orte, Facundo; Salvador, Jacobo; Quiroga, Jonathan; D'Elia, Raúl; Antón, Manuel; Alados-Arboledas, Lucas; Quel, Eduardo

    2017-02-01

    Anthropogenic perturbation of the ozone layer has induced change in the amount of UV radiation that reaches the Earth's surface, mainly through the Antarctic ozone hole, making the ozone and ultraviolet (UV) radiation two important issues in the study of Earth atmosphere in the scientific community. Also the clouds have been identified as the main modulator of UV amount in short time scales and produce the main source of uncertainty in the projection of surface UV level as consequence of projected ozone recovery. While clouds can decrease direct radiation, they can produce an increase in the diffuse component, and as consequence the surface UV radiation may be higher than an equivalent clear sky scenario for several minutes. In particular this situation can be important when low ozone column and partially cloud cover skies happen simultaneously. These situations happen frequently in southern Patagonia, where the CEILAP Lidar Division has established the Atmospheric Observatory of Southern Patagonia, an atmospheric remote sensing site near the city of Río Gallegos (51°55'S, 69°14'W). In this paper, the impact of clouds over the UV radiation is investigated by the use of ground based measurements from the passive remote sensing instruments operating at this site, mainly of broad and moderate narrow band filter radiometers. We analyzed the UV Index obtained from a multiband filter radiometer GUV-541 (UVI) [Biospherical Inc.] installed in the Observatorio Atmosférico de la Patagonia Austral, Río Gallegos, since 2005. Cloud modification factors (CMF, ratio between the measured UV radiation in a cloudy sky and the simulated radiation under cloud-free conditions) are evaluated for the study site. The database used in this work covers the period 2005-2012 for spring and summer seasons, when the ozone hole can affect these subpolar regions. CMF higher than 1 are found during spring and summer time, when lower total ozone columns, higher solar elevations and high cloud

  3. Two-dimensional grating guided-mode resonance tunable filter.

    Science.gov (United States)

    Kuo, Wen-Kai; Hsu, Che-Jung

    2017-11-27

    A two-dimensional (2D) grating guided-mode resonance (GMR) tunable filter is experimentally demonstrated using a low-cost two-step nanoimprinting technology with a one-dimensional (1D) grating polydimethylsiloxane mold. For the first nanoimprinting, we precisely control the UV LED irradiation dosage and demold the device when the UV glue is partially cured and the 1D grating mold is then rotated by three different angles, 30°, 60°, and 90°, for the second nanoimprinting to obtain 2D grating structures with different crossing angles. A high-refractive-index film ZnO is then coated on the surface of the grating structure to form the GMR filter devices. The simulation and experimental results demonstrate that the passband central wavelength of the filter can be tuned by rotating the device to change azimuth angle of the incident light. We compare these three 2D GMR filters with differential crossing angles and find that the filter device with a crossing angle of 60° exhibits the best performance. The tunable range of its central wavelength is 668-742 nm when the azimuth angle varies from 30° to 90°.

  4. Reverse-contact UV nanoimprint lithography for multilayered structure fabrication

    DEFF Research Database (Denmark)

    Kehagias, N.; Reboud, V.; Chansin, G.

    2007-01-01

    polymer areas are dissolved in a developer solution leaving behind the negative features of the original stamp. This method delivers resist pattern transfer without a residual layer, thereby rending unnecessary the etching steps typically needed in the imprint lithography techniques for three......In this paper, we report results on a newly developed nanofabrication technique, namely reverse-contact UV nanoimprint lithography. This technique is a combination of nanoimprint lithography and contact printing lithography. In this process, a lift-off resist and a UV cross-linkable polymer......-dimensional patterning. Three-dimensional woodpile-like structures were successfully fabricated with this new technique....

  5. Trends in the wide web converting markets for UV curing

    International Nuclear Information System (INIS)

    Fisher, R.

    1999-01-01

    As we prepare to enter a new decade, the use of ultraviolet (UV) energy to initiate the polymerization of coatings in the wide web segment of the Converting industry continues to increase. As is typical in the Converting industry, while many of the significant advances in technology have been developed around the world, they have been driven initially by the Western European markets. This was true with regards to the introduction of water-borne Pressure Sensitive Adhesives and thermal curing 100% solids silicone release coatings during the late 1970s and early 1980s, but this trend has changed with regards to the current state-of-the-art in UV curing

  6. Switching power supply filter

    Science.gov (United States)

    Kumar, Prithvi R. (Inventor); Abare, Wayne (Inventor)

    1989-01-01

    A filter for a switching power supply. The filter includes a common mode inductor with coil configurations allowing differential mode current from a dc source to pass through but attenuating common mode noise from the power supply so that the noise does not reach the dc source. The invention also includes the use of feed through capacitors at the switching power supply input terminals to provide further high-frequency noise attenuation.

  7. Spatial filter issues

    International Nuclear Information System (INIS)

    Murray, J.E.; Estabrook, K.G.; Milam, D.; Sell, W.D.; Van Wonterghem, R.M.; Feil, M.D.; Rubenchick, A.M.

    1996-01-01

    Experiments and calculations indicate that the threshold pressure in spatial filters for distortion of a transmitted pulse scales approximately as I O.2 and (F number-sign) 2 over the intensity range from 10 14 to 2xlO 15 W/CM 2 . We also demonstrated an interferometric diagnostic that will be used to measure the scaling relationships governing pinhole closure in spatial filters

  8. Solar UV light regulates flavonoid metabolism in apple (Malus x domestica).

    Science.gov (United States)

    Henry-Kirk, Rebecca A; Plunkett, Blue; Hall, Miriam; McGhie, Tony; Allan, Andrew C; Wargent, Jason J; Espley, Richard V

    2018-03-01

    Ultraviolet-B light (UV-B) is one environmental signal perceived by plants that affects the flavonoid pathway and influences the levels of anthocyanins, flavonols, and proanthocyanidins. To understand the mechanisms underlying UV exposure, apple trees were grown under spectral filters that altered transmission of solar UV light. Fruit analysis showed that UV induced changes in physiology, metabolism, and gene expression levels during development over a season. These changes were sustained after storage. Under low UV, ripening was delayed, fruit size decreased, and anthocyanin and flavonols were reduced. Expression analysis showed changes in response to UV light levels for genes in the regulation and biosynthesis of anthocyanin and flavonols. Transcription of flavonol synthase (FLS), ELONGATED HYPOCOTYL 5 (HY5), MYB10, and MYB22 were down-regulated throughout fruit development under reduced UV. Functional testing showed that the FLS promoter was activated by HY5, and this response was enhanced by the presence of MYB22. The MYB22 promoter can also be activated by the anthocyanin regulator, MYB10. As ambient levels of UV light vary around the globe, this study has implications for future crop production, the quality of which can be determined by the response to UV. © 2018 John Wiley & Sons Ltd.

  9. Antiradiation UV Vaccine: UV Radiation, Biological effects, lesions and medical management - immune-therapy and immune-protection.

    Science.gov (United States)

    Popov, Dmitri; Jones, Jeffrey; Maliev, Slava

    moderate and high doses of UV and ionizing radiation induce cell death by necrosis and generate systemic inflammatory response syndrome (SIRS), toxic multiple organ injury (TMOI), toxic multiple organ dysfunction syndromes (TMODS),and finally, toxic multiple organ failure (TMOF). [D.Popov et al.2012, Fliedner T.et al. 2005, T. Azizova et al. 2004] UV-B is a complete carcinogen that is absorbed by DNA and directly damages DNA. DNA damage induced by UV-B irradiation typically includes the formation of cyclobutane pyrimidine dimmers (CPD) and 6-4 photoproducts (6-4P)[IARC, Working Group Reports, M.Saraiya et al. 2004]. The pre-vaccinated animals seem to have a blunted injury response relative to the unvaccinated animals, presumably by reduction in the inflammatory response and secondary injury effects. The mechanism of action of the antiradiation vaccine, needs further evaluation. Conclusion: A UV antiradiation vaccine appears to demonstrate efficacy as a prophylactic agent for acute solar burns and toxicity. An antiradiation UV vaccine could be used in conjunction with adjunctive measures, e.g. antioxidants and UV barriers to reduce UV radiation toxicity. The authors of this experiments would like to propose further development work of the antiradiation UV vaccine to enhance the armamentarium for prophylaxis and prevention of the various forms skin cancer.

  10. [Reliable UV-light protection in intraocular lenses--scientific rationale and quality requirements].

    Science.gov (United States)

    Augustin, A J

    2014-09-01

    Since the late 1980s implantation of UV-blocker intraocular lenses during cataract surgery has become an internationally accepted standard. Last year the Kassenärztliche Vereinigung Bayern (KVB) and statutory health insurance organisations proposed for the first time quality criteria for intraocular lenses (IOL), thereby including exact parameters for the amount of UV light transmission (≤10% at 400 nm). Since then, the discussion has been raised again as to what extent IOLs should filter or block UV light. In this article, exact definitions of spectral subbands within the optical radiation band are given. Today, 400 nm is the internationally accepted standard to distinguish UV light and visible light. Moreover, exposure of the eye to UV radiation is described as well as mechanisms of photooxidative damage to the retina. Comprehensive laboratory and animal experimental studies show that light of short wave lengths, i.e., above all UV light but also blue light, may induce photochemical damage to the retina. Primary sites of such damage are both the outer segments of the photoreceptors and the retinal pigment epithelium (RPE). Physiological protective mechanisms of the eye, such as filtering properties of different ocular media are described in detail. Cornea, aqueous and vitreous absorb UV radiation below 300 nm, while the natural adult lens absorbs UV radiation between 300 and 400 nm. This protection is lost when the lens is removed by cataract surgery and thus should be restored. UV light does not contribute to vision but damages retinal structures. Therefore, UV-blocking intraocular lenses with a 10% cut-off near 400 nm should be implanted during cataract surgery. This ensures sufficient retinal protection after surgery. These theoretical considerations are supported by results from animal and clinical studies. Georg Thieme Verlag KG Stuttgart · New York.

  11. Some typical solid propellant rocket motors

    NARCIS (Netherlands)

    Zandbergen, B.T.C.

    2013-01-01

    Typical Solid Propellant Rocket Motors (shortly referred to as Solid Rocket Motors; SRM's) are described with the purpose to form a database, which allows for comparative analysis and applications in practical SRM engineering.

  12. Efficacy of photocatalytic HEPA filter on microorganism removal.

    Science.gov (United States)

    Chuaybamroong, P; Chotigawin, R; Supothina, S; Sribenjalux, P; Larpkiattaworn, S; Wu, C-Y

    2010-06-01

    This study assessed the application of photocatalytic oxidation (PCO) to the high efficiency particulate air (HEPA) filter for disinfection of airborne microorganisms. Experiments were conducted at two TiO2 loadings (1870 +/- 169 and 3140 +/- 67 mg/m(2)) on the HEPA filter irradiated with UV-A at the intensity of 0.85 +/- 0.18 or 4.85 +/- 0.09 mW/cm(2) under two relative humidity conditions (45 +/- 5% and 75 +/- 5%). Inactivation and penetration of four microorganisms were tested, including Aspergillus niger, Penicillium citrinum, Staphylococcus epidermidis, and Bacillus subtilis. It was found that microorganisms retained on a photocatalytic filter were inactivated around 60-80% and even 100% for S. epidermidis when the PCO reactions occurred. Lower penetration was also found from the photocatalytic filter for all airborne microorganisms. High humidity decreased photocatalysis efficacy. Increasing TiO2 loading or irradiance intensity did not substantially affect its disinfection capability. The high efficiency particulate air filter is used widely to remove particulates and microorganisms from the air stream. However, the filter may become a source of microbes if those retained microorganisms proliferate and re-entrain back into the filtered air. This study demonstrates that such a problem can be handled effectively by using photocatalytic reactions to inactivate those confined microorganisms. A 60-100% microbe reduction can be achieved for a wide variety of microorganisms to provide better indoor air quality for hospitals, offices, and domestic applications.

  13. Sensory Pollution from Bag Filters, Carbon Filters and Combinations

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Clausen, Geo; Weschler, Charles J.

    2008-01-01

    Used ventilation filters are a major source of sensory pollutants in air handling systems. The objective of the present study was to evaluate the net effect that different combinations of filters had on perceived air quality after 5 months of continuous filtration of outdoor suburban air. A panel...... that contained AC and a synthetic fiber cartridge filter that contained AC. Air that had passed through used filters was most acceptable for those sets in which an AC filter was used downstream of the particle filter. Comparable air quality was achieved with the stand-alone bag filter that contained AC...

  14. Prediction and typicality in multiverse cosmology

    International Nuclear Information System (INIS)

    Azhar, Feraz

    2014-01-01

    In the absence of a fundamental theory that precisely predicts values for observable parameters, anthropic reasoning attempts to constrain probability distributions over those parameters in order to facilitate the extraction of testable predictions. The utility of this approach has been vigorously debated of late, particularly in light of theories that claim we live in a multiverse, where parameters may take differing values in regions lying outside our observable horizon. Within this cosmological framework, we investigate the efficacy of top-down anthropic reasoning based on the weak anthropic principle. We argue contrary to recent claims that it is not clear one can either dispense with notions of typicality altogether or presume typicality, in comparing resulting probability distributions with observations. We show in a concrete, top-down setting related to dark matter, that assumptions about typicality can dramatically affect predictions, thereby providing a guide to how errors in reasoning regarding typicality translate to errors in the assessment of predictive power. We conjecture that this dependence on typicality is an integral feature of anthropic reasoning in broader cosmological contexts, and argue in favour of the explicit inclusion of measures of typicality in schemes invoking anthropic reasoning, with a view to extracting predictions from multiverse scenarios. (paper)

  15. Resistance of human and mouse myeloid leukemia cells to UV radiation

    International Nuclear Information System (INIS)

    Poljak-Blazi, M.; Osmak, M.; Hadzija, M.

    1989-01-01

    Sensitivity of mouse bone marrow and myeloid leukemia cells and sensitivity of human myeloid leukemia cells to UV light was tested. Criteria were the in vivo colony-forming ability of UV exposed cells and the inhibition of DNA synthesis during post-irradiation incubation for 24 h in vitro. Mouse bone marrow cells irradiated with a small dose of UV light (5 J/m 2 ) and injected into x-irradiated animals did not form hemopoietic colonies on recipient's spleens, and recipients died. However, mouse leukemia cells, after irradiation with higher doses of UV light, retained the ability to form colonies on the spleens, and all recipient mice died with typical symptoms of leukemia. In vitro, mouse bone marrow cells exhibited high sensitivity to UV light compared to mouse myeloid leukemia cells. Human leukemia cells were also resistant to UV light, but more sensitive than mouse leukemia cells. (author)

  16. In vitro evidence for UV-protection of the eye by the corneal epithelium mediated by the cytoplasmic protein, RNA, and ascorbate.

    Science.gov (United States)

    Ringvold, A

    1997-10-01

    (1) To evaluate the effect of ribonucleic acid (RNA) and ascorbate on UV-absorption and their impact on ultraviolet-induced (UV) fluorescence from various proteins, and (2) to compare RNA and DNA reduction of protein fluorescence. These informations will be useful for later work on the UV-filtering effect of the corneal epithelium. Spectrophotometry and spectrofluorimetry. (1) RNA and ascorbate caused a significant UV-absorption and reduced the fluorescence from various water-soluble proteins, the degree of reduction varying independently from one protein to the other. (2) RNA and DNA showed protein fluorescence reduction of roughly the same order. The results are discussed both in the context of UV-protection of the cell nucleus in general, and the possible UV-filtering effect for the eye of bovine corneal epithelium.

  17. Choosing and using astronomical filters

    CERN Document Server

    Griffiths, Martin

    2014-01-01

    As a casual read through any of the major amateur astronomical magazines will demonstrate, there are filters available for all aspects of optical astronomy. This book provides a ready resource on the use of the following filters, among others, for observational astronomy or for imaging: Light pollution filters Planetary filters Solar filters Neutral density filters for Moon observation Deep-sky filters, for such objects as galaxies, nebulae and more Deep-sky objects can be imaged in much greater detail than was possible many years ago. Amateur astronomers can take

  18. UV Excited Photoacoustic Raman

    Energy Technology Data Exchange (ETDEWEB)

    Carter, J. Chance [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Chambers, David H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Steele, Paul T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Haugen, Peter [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Heller, Don [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-11-15

    To summarize, our efforts and findings are as follows: we analyzed the theoretical system performance using known PARS theory coupled with an acoustic detector model to estimate the expected signal-­to-noise ratio (SNR). The system model comprised a mathematical model of the Raman process leading to a prediction of the temperature change in the active region; a thermoacoustic gas prediction of the radiated pressure field (amplitude and pulse shape); and the receiver response for an acoustic microphone, including a simple model of the receiver circuitry (filters, integrators, etc.). Based on the PARS experimental parameters in Appendix B, the model predicted a PARS signal with pressure peak of 7 Pa and duration slightly longer than 2 ms at a distance of 7 mm from the focal spot when acoustic dissipation is not included. An analytical model of a PARS signal with acoustic dissipation was constructed but the numerical calculation is limited to gains of <1% of the experimental value. For these lower gains, the model predicts spreading of the signal.

  19. Low-power adaptive filter based on RNS components

    DEFF Research Database (Denmark)

    Bernocchi, Gian Luca; Cardarilli, Gian Carlo; Del Re, Andrea

    2007-01-01

    In this paper a low-power implementation of an adaptive FIR filter is presented. The filter is designed to meet the constraints of channel equalization for fixed wireless communications that typically requires a large number of taps, but a serial updating of the filter coefficients, based...... on the least mean squares (LMS) algorithm, is allowed. Previous work showed that the use of the residue number system (RNS) for the variable FIR filter grants advantages both in area and power consumption. On the other hand, the use of a binary serial implementation of the adaptation algorithm eliminates...... the need for complex scaling circuits in RNS. The advantages in terms of area and speed of the presented filter, with respect to its two's complement counterpart, are evaluated for implementations in standard cells....

  20. A Siren Detection System based on Mechanical Resonant Filters

    Directory of Open Access Journals (Sweden)

    John N. Avaritsiotis

    2001-09-01

    Full Text Available A system based on mechanical resonant filters is proposed that can be used for the detection of acoustical signals the frequency components of which vary according to specific periodic patterns. Usually, signals of this category produced by the siren of an emergency vehicle. The device essentially implements a mechanical narrow filter bank that covers the frequency range of a typical siren sound. Signal detection is obtained by measuring the time delay between successive activation of the filters of the bank. The whole analysis reveals how a set of simple, low-cost mechanical resonant filters can replace an electronic analog or digital system for the implementation of a filter bank. Moreover, a scaling down procedure is proposed so that a microsystem may be developed.

  1. Effects of ultraviolet-B (UV-B) radiation on two cryptogamic plants ...

    African Journals Online (AJOL)

    rudra

    Two plant species, lichen (X. elegans) and moss (B. argenteum) were selected and both were growing naturally on the mountains with other cryptogamic vegetation (Figure 2a and b). We have selected these plants for the field experiments because of their uniform growth, availability and UV-B filter frames can be placed.

  2. Photocatalytic ROS production and phototoxicity of titanium dioxide nanoparticles is dependent on solar UV radiation spectrum

    Science.gov (United States)

    Generation of reactive oxygen species (ROS) by titanium dioxide nanoparticles (nano-TiO2) and its consequent phototoxicity to Daphnia magna were measured under different solar UV radiation spectrum by applying a series of optical filters in a solar simulator. Removing UVB (280-32...

  3. D-glucose:oxygen-1-oxidoreductase by using Aspergillus niger UV ...

    African Journals Online (AJOL)

    Jane

    2011-10-24

    Oct 24, 2011 ... type Aspergillus niger was subjected to ultraviolet radiation for enhanced production of glucose oxidase. It was found that ... Optimum production of glucose oxidase from A. niger UV-180-C was carried out by using CSL. (2%), fermentation period .... using Whatman filter paper No. 1 and centrifuged for 15 ...

  4. Multilevel ensemble Kalman filtering

    KAUST Repository

    Hoel, Haakon

    2016-01-08

    The ensemble Kalman filter (EnKF) is a sequential filtering method that uses an ensemble of particle paths to estimate the means and covariances required by the Kalman filter by the use of sample moments, i.e., the Monte Carlo method. EnKF is often both robust and efficient, but its performance may suffer in settings where the computational cost of accurate simulations of particles is high. The multilevel Monte Carlo method (MLMC) is an extension of classical Monte Carlo methods which by sampling stochastic realizations on a hierarchy of resolutions may reduce the computational cost of moment approximations by orders of magnitude. In this work we have combined the ideas of MLMC and EnKF to construct the multilevel ensemble Kalman filter (MLEnKF) for the setting of finite dimensional state and observation spaces. The main ideas of this method is to compute particle paths on a hierarchy of resolutions and to apply multilevel estimators on the ensemble hierarchy of particles to compute Kalman filter means and covariances. Theoretical results and a numerical study of the performance gains of MLEnKF over EnKF will be presented. Some ideas on the extension of MLEnKF to settings with infinite dimensional state spaces will also be presented.

  5. 105 GHz Notch Filter Design for Collective Thomson Scattering

    DEFF Research Database (Denmark)

    Furtula, Vedran; Michelsen, Poul; Leipold, Frank

    2011-01-01

    A millimeter-wave notch filter with 105-GHz center frequency, >20-GHz passband coverage, and 1-GHz rejection bandwidth has been constructed. The design is based on a fundamental rectangular waveguide with cylindrical cavities coupled by narrow iris gaps, i.e., small elongated holes of negligible...... thickness. We use numerical simulations to study the sensitivity of the notch filter performance to changes in geometry and in material conductivity within a bandwidth of ±10 GHz. The constructed filter is tested successfully using a vector network analyzer monitoring a total bandwidth of 20 GHz....... The typical insertion loss in the passband is...

  6. A new parameterization of the UV irradiance altitude dependence for clear-sky conditions and its application in the on-line UV tool over Northern Eurasia

    Directory of Open Access Journals (Sweden)

    N. Chubarova

    2016-09-01

    Full Text Available A new method for calculating the altitude UV dependence is proposed for different types of biologically active UV radiation (erythemally weighted, vitamin-D-weighted and cataract-weighted types. We show that for the specified groups of parameters the altitude UV amplification (AUV can be presented as a composite of independent contributions of UV amplification from different factors within a wide range of their changes with mean uncertainty of 1 % and standard deviation of 3 % compared with the exact model simulations with the same input parameters. The parameterization takes into account for the altitude dependence of molecular number density, ozone content, aerosol and spatial surface albedo. We also provide generalized altitude dependencies of the parameters for evaluating the AUV. The resulting comparison of the altitude UV effects using the proposed method shows a good agreement with the accurate 8-stream DISORT model simulations with correlation coefficient r  >  0.996. A satisfactory agreement was also obtained with the experimental UV data in mountain regions. Using this parameterization we analyzed the role of different geophysical parameters in UV variations with altitude. The decrease in molecular number density, especially at high altitudes, and the increase in surface albedo play the most significant role in the UV growth. Typical aerosol and ozone altitude UV effects do not exceed 10–20 %. Using the proposed parameterization implemented in the on-line UV tool (http://momsu.ru/uv/ for Northern Eurasia over the PEEX domain we analyzed the altitude UV increase and its possible effects on human health considering different skin types and various open body fraction for January and April conditions in the Alpine region.

  7. UV/EB curable psa's

    International Nuclear Information System (INIS)

    Glotfelter, C.A.

    1995-01-01

    The author describe both water-based and 100% solids UV/EB curable PSA's (Pressure Sensitive Adhesives) and their properties. A new acrylate monomer, ethoxylated nonyl phenol acrylate, has great utility in the formulation of water-based PSA's

  8. Health Effects of UV Radiation

    Science.gov (United States)

    ... Related Topics: Sun Safety Contact Us Share Health Effects of UV Radiation Ozone layer depletion decreases our ... against these invaders. Fact Sheet Download the Health Effects of Overexposure to the Sun (PDF) Did You ...

  9. The effect of UV stars on the intergalactic medium. II

    International Nuclear Information System (INIS)

    Sonnanstine, A.E.; Hills, J.G.

    1976-01-01

    The effect of ionizing radiation from the UV stars (hot prewhite dwarfs) on the intergalactic medium (IGM) has been investigated. If the UV stars are powered only by gravitational contraction they radiate most of their energy at a typical surface temperature of 1.5 x 10 5 K which produces a very highly ionized IGM in which the elements carbon, nitrogen and oxygen are left with only one or two electrons. This result in these elements being very inefficient coolants. The gas is cooled principally by free-free emission and the collisional ionization of hydrogen and helium. For a typical UV star temperature of T=1.5 x 10 5 K, the temperature of the ionized gas in the IGM is Tsub(g)=1.2 x 10 5 K for a Hubble constant H 0 =75 kms -1 Mpc -1 and a hydrogen density nsub(H)=10 -6 cm -3 . Heating by cosmic rays and X-rays is insignificant in the IGM except perhaps in the H I clouds because when a hydrogen atom recombines in the IGM it is far more likely to be re-ionized by a UV-star photon than by either of the other two types of particles due to the greater space density of UV-star photons and their appreciably larger ionization cross sections. If the UV stars radiate a substantial fraction of their energy in a helium-burning stage in which they have surface temperatures of about 5 x 10 4 K, the temperature of the IGM could be lowered to about 5 x 10 4 K. (Auth.)

  10. Induction of sister-chromatid exchanges in ICR 2A frog cells exposed to 254 nm UV wavelengths

    International Nuclear Information System (INIS)

    Chao, C.C.K.; Rosenstein, B.S.

    1985-01-01

    Exposure of ICR 2A frog cells to 254 nm UV induced the formation of sister-chromatid exchanges (SCEs) in a fluence-dependent manner. Cells were also exposed to the UV produced by a fluorescent sunlamp that was filtered through 8C Mylar in order to simulate the mid-UV (290-320 nm) portion of sunlight reaching the earth's surface. In this instance, SCEs were induced in a linear fashion at low fluences but reached a plateau at a low level of induced SCEs. In addition, pretreatment of cells with the solar UV followed by exposure to 254 nm UV resulted in a significantly lower level of SCEs than in cells exposed to 254 nm UV alone. (author)

  11. Adaptive digital filters

    CERN Document Server

    Kovačević, Branko; Milosavljević, Milan

    2013-01-01

    “Adaptive Digital Filters” presents an important discipline applied to the domain of speech processing. The book first makes the reader acquainted with the basic terms of filtering and adaptive filtering, before introducing the field of advanced modern algorithms, some of which are contributed by the authors themselves. Working in the field of adaptive signal processing requires the use of complex mathematical tools. The book offers a detailed presentation of the mathematical models that is clear and consistent, an approach that allows everyone with a college level of mathematics knowledge to successfully follow the mathematical derivations and descriptions of algorithms.   The algorithms are presented in flow charts, which facilitates their practical implementation. The book presents many experimental results and treats the aspects of practical application of adaptive filtering in real systems, making it a valuable resource for both undergraduate and graduate students, and for all others interested in m...

  12. Stack filter classifiers

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Reid B [Los Alamos National Laboratory; Hush, Don [Los Alamos National Laboratory

    2009-01-01

    Just as linear models generalize the sample mean and weighted average, weighted order statistic models generalize the sample median and weighted median. This analogy can be continued informally to generalized additive modeels in the case of the mean, and Stack Filters in the case of the median. Both of these model classes have been extensively studied for signal and image processing but it is surprising to find that for pattern classification, their treatment has been significantly one sided. Generalized additive models are now a major tool in pattern classification and many different learning algorithms have been developed to fit model parameters to finite data. However Stack Filters remain largely confined to signal and image processing and learning algorithms for classification are yet to be seen. This paper is a step towards Stack Filter Classifiers and it shows that the approach is interesting from both a theoretical and a practical perspective.

  13. Automated electronic filter design

    CERN Document Server

    Banerjee, Amal

    2017-01-01

    This book describes a novel, efficient and powerful scheme for designing and evaluating the performance characteristics of any electronic filter designed with predefined specifications. The author explains techniques that enable readers to eliminate complicated manual, and thus error-prone and time-consuming, steps of traditional design techniques. The presentation includes demonstration of efficient automation, using an ANSI C language program, which accepts any filter design specification (e.g. Chebyschev low-pass filter, cut-off frequency, pass-band ripple etc.) as input and generates as output a SPICE(Simulation Program with Integrated Circuit Emphasis) format netlist. Readers then can use this netlist to run simulations with any version of the popular SPICE simulator, increasing accuracy of the final results, without violating any of the key principles of the traditional design scheme.

  14. Direct effects of elevated UV-B radiation on the decomposition of Quercus robur leaf litter

    International Nuclear Information System (INIS)

    Newsham, K.K.; McLeod, A.R.; Roberts, J.D.; Greenslade, P.D.; Emmett, B.A.

    1997-01-01

    Decomposing Quercus robur L. leaf litter was exposed for 64 weeks at an outdoor facility to supplemental levels of UV-B radiation (280-315 nm) under treatment arrays of cellulose diacetate-filtered fluorescent lamps which also produce UV-A radiation (315-400 nm). Litter was also exposed to UV-A radiation alone under control arrays of polyester-filtered lamps and to ambient levels of solar radiation under arrays of unenergised lamps. The treatment corresponded to a 30% elevation above the ambient erythemally-weighted level of UV-B radiation. Litter was sampled after 11, 39 and 64 weeks and was examined for differences in mass loss, decomposition constants (k), chemical composition and the abundances of saprotrophic fungi. No effects of UV radiation on k values were recorded, but after 11 weeks, percentage mass loss of litter exposed to UV-B radiation under treatment arrays was 3% lower than under control arrays and 2% lower than under ambient arrays. After 39 weeks, litters exposed to UV-A radiation under control arrays had 10% lower total nitrogen contents and 13% higher C:N ratios than those litters exposed beneath ambient arrays. At the last sampling, litters exposed to supplemental UV-B radiation had 5% higher carbon contents than those under ambient arrays. A 2.4-fold increase in the frequency of lamina particles of litter that were uncolonised by fungi was recorded in litter exposed to UV-B radiation under treatment arrays, compared to ambient arrays. The abundances of the saprotrophic fungi Cladosporium spp. and Acremonium persicinum (Nicot) W. Gams were decreased by 50% and 91%, respectively, under UV-B treatment arrays compared to ambient arrays, and the abundance of coelomycete conidiomata recorded on leaves was increased by 12% under treatment arrays, compared to ambient. Dactylella spp. were not recorded on litter exposed to UV-A radiation under control arrays and UV-A radiation applied under control and treatment arrays apparently increased the

  15. Typical horticultural products between tradition and innovation

    Directory of Open Access Journals (Sweden)

    Innocenza Chessa

    2009-10-01

    Full Text Available Recent EU and National policies for agriculture and rural development are mainly focused to foster the production of high quality products as a result of the increasing demand of food safety, typical foods and traditional processing methods. Another word very often used to describe foods in these days is “typicality” which pools together the concepts of “food connected with a specific place”, “historical memory and tradition” and “culture”. The importance for the EU and the National administrations of the above mentioned kind of food is demonstrated, among other things, by the high number of the PDO, PGI and TSG certificated products in Italy. In this period of global markets and economical crisis farmers are realizing how “typical products” can be an opportunity to maintain their market share and to improve the economy of local areas. At the same time, new tools and strategy are needed to reach these goals. A lack of knowledge has being recognized also on how new technologies and results coming from recent research can help in exploiting traditional product and in maintaining the biodiversity. Taking into account the great variety and richness of typical products, landscapes and biodiversity, this report will describe and analyze the relationships among typicality, innovation and research in horticulture. At the beginning “typicality” and “innovation” will be defined also through some statistical features, which ranks Italy at the first place in terms of number of typical labelled products, then will be highlighted how typical products of high quality and connected with the tradition and culture of specific production areas are in a strict relationship with the value of agro-biodiversity. Several different examples will be used to explain different successful methods and/or strategies used to exploit and foster typical Italian vegetables, fruits and flowers. Finally, as a conclusion, since it is thought that

  16. Spectral filtering for plant production

    Science.gov (United States)

    Young, Roy E.; Mcmahon, Margaret J.; Rajapakse, Nihal C.; Decoteau, Dennis R.

    1994-01-01

    Both plants and animals have one general commonality in their perception of light. They both are sensitive primarily to the 400 to 700 nm wavelength portion of the electromagnetic spectrum. This is referred to as the visible spectrum for animals and as the photosynthetically active radiation (PAR) spectrum for plants. Within this portion of the spectrum, animals perceive colors. Relatively recently it has been learned that within this same spectral range plants also demonstrate varying responses at different wavelengths, somewhat analogous to the definition of various colors at specific wavelengths. Although invisible to the human eye, portions of the electromagnetic spectrum on either side of the visible range are relatively inactive photosynthetically but have been found to influence important biological functions. These portions include the ultraviolet (UV approximately equal to 280-400 nm) and the far-red (FR approximately equal to 700-800 nm). The basic photoreceptor of plants for photosynthesis is chlorophyll. It serves to capture radiant energy which combined with carbon dioxide and water produces oxygen and assimulated carbon, used for the synthesis of cell wall polysaccarides, proteins, membrane lipids and other cellular constituents. The energy and carbon building blocks of photosynthesis sustain growth of plants. On the other hand, however, there are other photoreceptors, or pigments, that function as signal transducers to provide information that controls many physiological and morphological responses of how a plant grows. Known photomorphogenic receptors include phytochrome (the red/far-red sensor in the narrow bands of 655-665 nm and 725-735 nm ranges, respectively) and 'cryptochrome' (the hypothetical UV-B sensor in the 280-320 nm range). Since the USDA team of W. L. Butler, S. B. Hendricks, H. A. Borthwick, H. A. Siegleman and K. Norris in Beltsville, MD detected by spectroscopy, extracted and identified phytochrome as a protein in the 1950's, many

  17. Filters in topology optimization

    DEFF Research Database (Denmark)

    Bourdin, Blaise

    1999-01-01

    In this article, a modified (``filtered'') version of the minimum compliance topology optimization problem is studied. The direct dependence of the material properties on its pointwise density is replaced by a regularization of the density field using a convolution operator. In this setting...... it is possible to establish the existence of solutions. Moreover, convergence of an approximation by means of finite elements can be obtained. This is illustrated through some numerical experiments. The ``filtering'' technique is also shown to cope with two important numerical problems in topology optimization...

  18. Alarm filtering and presentation

    International Nuclear Information System (INIS)

    Bray, M.A.

    1989-01-01

    This paper discusses alarm filtering and presentation in the control room of nuclear and other process control plants. Alarm generation and presentation is widely recognized as a general process control problem. Alarm systems often fail to provide meaningful alarms to operators. Alarm generation and presentation is an area in which computer aiding is feasible and provides clear benefits. Therefore, researchers have developed several computerized alarm filtering and presentation approaches. This paper discusses problems associated with alarm generation and presentation. Approaches to improving the alarm situation and installation issues of alarm system improvements are discussed. The impact of artificial intelligence (AI) technology on alarm system improvements is assessed. (orig.)

  19. UV-induced DNA-binding proteins in human cells

    International Nuclear Information System (INIS)

    Glazer, P.M.; Greggio, N.A.; Metherall, J.E.; Summers, W.C.

    1989-01-01

    To investigate the response of human cells to DNA-damaging agents such as UV irradiation, the authors examined nuclear protein extracts of UV-irradiated HeLa cells for the presence of DNA-binding proteins. Electrophoretically separated proteins were transferred to a nitrocellulose filter that was subsequently immersed in a binding solution containing radioactively labeled DNA probes. Several DNA-binding proteins were induced in HeLa cells after UV irradiation. These included proteins that bind predominantly double-stranded DNA and proteins that bind both double-stranded and single-stranded DNA. The binding proteins were induced in a dose-dependent manner by UV light. Following a dose of 12 J/m 2 , the binding proteins in the nuclear extracts increased over time to a peak in the range of 18 hr after irradiation. Experiments with metabolic inhibitors (cycloheximide and actinomycin D) revealed that de novo synthesis of these proteins is not required for induction of the binding activities, suggesting that the induction is mediated by protein modification

  20. A novel research model for evaluating sunscreen protection in the UV-A1.

    Science.gov (United States)

    Figueiredo, Sônia Aparecida; de Moraes, Dayane Cristina; Vilela, Fernanda Maria Pinto; de Faria, Amanda Natalina; Dos Santos, Marcelo Henrique; Fonseca, Maria José Vieira

    2018-01-01

    The use of a broad spectrum sunscreen is considered one of the main and most popular measures for preventing the damaging effects of ultraviolet radiation (UVR) on the skin. In this study we have developed a novel in vitro method to assess sunscreens efficacy to protect calcineurin enzyme activity, a skin cell marker. The photoprotective efficacy of sunscreen products was assessed by measuring the UV-A1 radiation-induced depletion of calcineurin (Cn) enzyme activity in primary neonatal human dermal fibroblast (HDFn) cell lysates. After exposure to 24J/cm 2 UV-A1 radiation, the sunscreens containing larger amounts of UV-A1 filters (brand B), the astaxanthin (UV-A1 absorber) and the Tinosorb® M (UV-A1 absorber) were capable of preventing loss of Cn activity when compared to the sunscreens formulations of brand A (low concentration of UV-A1 filters), with the Garcinia brasiliensis extract (UV-B absorber) and with the unprotected cell lysate and exposed to irradiation (Irradiated Control - IC). The Cn activity assay is a reproducible, accurate and selective technique for evaluating the effectiveness of sunscreens against the effects of UV-A1 radiation. The developed method showed that calcineurin activity have the potential to act as a biological indicator of UV-A1 radiation-induced damages in skin and the assay might be used to assess the efficacy of sunscreens agents and plant extracts prior to in vivo tests. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Towards a high performing UV-A sensor based on Silicon Carbide and hydrogenated Silicon Nitride absorbing layers

    International Nuclear Information System (INIS)

    Mazzillo, M.; Renna, L.; Costa, N.; Badalà, P.; Sciuto, A.; Mannino, G.

    2016-01-01

    Exposure to ultraviolet (UV) radiation is a major risk factor for most skin cancers. The sun is our primary natural source of UV radiation. The strength of the sun's ultraviolet radiation is expressed as Solar UV Index (UVI). UV-A (320–400 nm) and UV-B (290–320 nm) rays mostly contribute to UVI. UV-B is typically the most destructive form of UV radiation because it has enough energy to cause photochemical damage to cellular DNA. Also overexposure to UV-A rays, although these are less energetic than UV-B photons, has been associated with toughening of the skin, suppression of the immune system, and cataract formation. The use of preventive measures to decrease sunlight UV radiation absorption is fundamental to reduce acute and irreversible health diseases to skin, eyes and immune system. In this perspective UV sensors able to monitor in a monolithic and compact chip the UV Index and relative UV-A and UV-B components of solar spectrum can play a relevant role for prevention, especially in view of the integration of these detectors in close at hand portable devices. Here we present the preliminary results obtained on our UV-A sensor technology based on the use of hydrogenated Silicon Nitride (SiN:H) thin passivating layers deposited on the surface of thin continuous metal film Ni_2Si/4H-SiC Schottky detectors, already used for UV-Index monitoring. The first UV-A detector prototypes exhibit a very low leakage current density of about 0.2 pA/mm"2 and a peak responsivity value of 0.027 A/W at 330 nm, both measured at 0V bias.

  2. UV absorbance of a bioengineered corneal stroma substitute in the 240-400 nm range.

    Science.gov (United States)

    Ionescu, Ana-Maria; de la Cruz Cardona, Juan; González-Andrades, Miguel; Alaminos, Miguel; Campos, Antonio; Hita, Enrique; del Mar Pérez, María

    2010-08-01

    To determine the UV absorbance of a bioengineered human corneal stroma construct based on fibrin and fibrin-agarose scaffolds in the 240-400 nm range. Three types of artificial substitutes of the human corneal stroma were developed by tissue engineering using fibrin and fibrin with 0.1% and 0.2% agarose scaffolds with human keratocytes immersed within. After 28 days of culture, the UV absorbance of each sample was determined using a spectrophotometer. The thickness of corneal stroma samples was determined by light microscope. For all the 3 types of corneal stroma substitutes studied, the range of the UV absorbance values was similar to that of the native human corneal stroma, although the fibrin with 0.1% agarose stroma substitute had the best UV filtering properties. The higher UV absorbance of the artificial substitute of the human corneal stroma was in the UV-B and -A ranges, suggesting that these artificial tissues could have potential clinical usefulness and proper UV light-absorption capabilities. Our data suggest that the bioengineered human corneal substitute of fibrin with 0.1% agarose is an effective absorber of harmful UV radiation and could therefore be potentially useful.

  3. TYPICAL FORMS OF LIVER PATHOLOGY IN CHILDREN

    Directory of Open Access Journals (Sweden)

    Peter F. Litvitskiy

    2018-01-01

    Full Text Available This lecture for the system of postgraduate medical education analyzes causes, types, key links of pathogenesis, and manifestations of the main typical forms of liver pathology — liver failure, hepatic coma, jaundice, cholemia, acholia, cholelithiasis, and their complications in children. To control the retention of the lecture material, case problems and multiple-choice tests are given.

  4. Typical electric bills, January 1, 1981

    International Nuclear Information System (INIS)

    1981-01-01

    The Typical Electric Bills report is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration; Department of Energy. The publication is geared to a variety of applications by electric utilities, industry, consumes, educational institutions, and government in recognition of the growing importance of energy planning in contemporary society. 19 figs., 18 tabs

  5. Statistically-Efficient Filtering in Impulsive Environments: Weighted Myriad Filters

    Directory of Open Access Journals (Sweden)

    Gonzalez Juan G

    2002-01-01

    Full Text Available Linear filtering theory has been largely motivated by the characteristics of Gaussian signals. In the same manner, the proposed Myriad Filtering methods are motivated by the need for a flexible filter class with high statistical efficiency in non-Gaussian impulsive environments that can appear in practice. Myriad filters have a solid theoretical basis, are inherently more powerful than median filters, and are very general, subsuming traditional linear FIR filters. The foundation of the proposed filtering algorithms lies in the definition of the myriad as a tunable estimator of location derived from the theory of robust statistics. We prove several fundamental properties of this estimator and show its optimality in practical impulsive models such as the -stable and generalized- . We then extend the myriad estimation framework to allow the use of weights. In the same way as linear FIR filters become a powerful generalization of the mean filter, filters based on running myriads reach all of their potential when a weighting scheme is utilized. We derive the "normal" equations for the optimal myriad filter, and introduce a suboptimal methodology for filter tuning and design. The strong potential of myriad filtering and estimation in impulsive environments is illustrated with several examples.

  6. UV-VIS absorption spectroscopy: Lambert-Beer reloaded.

    Science.gov (United States)

    Mäntele, Werner; Deniz, Erhan

    2017-02-15

    UV-VIS absorption spectroscopy is used in almost every spectroscopy laboratory for routine analysis or research. All spectroscopists rely on the Lambert-Beer Law but many of them are less aware of its limitations. This tutorial discusses typical problems in routine spectroscopy that come along with technical limitations or careless selection of experimental parameters. Simple rules are provided to avoid these problems. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. DNA damage caused by UV- and near UV-irradiation

    International Nuclear Information System (INIS)

    Ohnishi, Takeo

    1986-01-01

    Much work with mutants deficient in DNA repair has been performed concerning UV-induced DNA damage under the condition where there is no artificial stimulation. In an attempt to infer the effects of solar wavelengths, the outcome of the work is discussed in terms of cellular radiation sensitivity, unscheduled DNA synthesis, and mutation induction, leading to the conclusion that some DNA damage occurs even by irradiation of the shorter wavelength light (270 - 315 nm) and is repaired by excision repair. It has been thought to date that pyrimidine dimer (PD) plays the most important role in UV-induced DNA damage, followed by (6 - 4) photoproducts. As for DNA damage induced by near UV irradiation, the yield of DNA single-strand breaks and of DNA-protein crosslinking, other than PD, is considered. The DNA-protein crosslinking has proved to be induced by irradiation at any wavelength of UV ranging from 260 to 425 nm. Near UV irradiation causes the inhibition of cell proliferation to take place. (Namekawa, K.)

  8. The ATLAS event filter

    CERN Document Server

    Beck, H P; Boissat, C; Davis, R; Duval, P Y; Etienne, F; Fede, E; Francis, D; Green, P; Hemmer, F; Jones, R; MacKinnon, J; Mapelli, Livio P; Meessen, C; Mommsen, R K; Mornacchi, Giuseppe; Nacasch, R; Negri, A; Pinfold, James L; Polesello, G; Qian, Z; Rafflin, C; Scannicchio, D A; Stanescu, C; Touchard, F; Vercesi, V

    1999-01-01

    An overview of the studies for the ATLAS Event Filter is given. The architecture and the high level design of the DAQ-1 prototype is presented. The current status if the prototypes is briefly given. Finally, future plans and milestones are given. (11 refs).

  9. Spectral Ensemble Kalman Filters

    Czech Academy of Sciences Publication Activity Database

    Mandel, Jan; Kasanický, Ivan; Vejmelka, Martin; Fuglík, Viktor; Turčičová, Marie; Eben, Kryštof; Resler, Jaroslav; Juruš, Pavel

    2014-01-01

    Roč. 11, - (2014), EMS2014-446 [EMS Annual Meeting /14./ & European Conference on Applied Climatology (ECAC) /10./. 06.10.2014-10.10.2014, Prague] R&D Projects: GA ČR GA13-34856S Grant - others:NSF DMS -1216481 Institutional support: RVO:67985807 Keywords : data assimilation * spectral filter Subject RIV: DG - Athmosphere Sciences, Meteorology

  10. Filter and Passband Problems

    Science.gov (United States)

    Young, A. T.

    1984-01-01

    Problems associated with achieving precision in photometric measurements of stars are examined. The thermal stabilization of glass and interference filters and the determination of correct analytic representations of bandwidth effects in data reduction are particularly discussed. Spectral sampling requirements are also addressed.

  11. Ceramic HEPA Filter Program

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, M A; Bergman, W; Haslam, J; Brown, E P; Sawyer, S; Beaulieu, R; Althouse, P; Meike, A

    2012-04-30

    Potential benefits of ceramic filters in nuclear facilities: (1) Short term benefit for DOE, NRC, and industry - (a) CalPoly HTTU provides unique testing capability to answer questions for DOE - High temperature testing of materials, components, filter, (b) Several DNFSB correspondences and presentations by DNFSB members have highlighted the need for HEPA filter R and D - DNFSB Recommendation 2009-2 highlighted a nuclear facility response to an evaluation basis earthquake followed by a fire (aka shake-n-bake) and CalPoly has capability for a shake-n-bake test; (2) Intermediate term benefit for DOE and industry - (a) Filtration for specialty applications, e.g., explosive applications at Nevada, (b) Spin-off technologies applicable to other commercial industries; and (3) Long term benefit for DOE, NRC, and industry - (a) Across industry, strong desire for better performance filter, (b) Engineering solution to safety problem will improve facility safety and decrease dependence on associated support systems, (c) Large potential life-cycle cost savings, and (d) Facilitates development and deployment of LLNL process innovations to allow continuous ventilation system operation during a fire.

  12. Development of a molecular method for testing the effectiveness of UV systems on-site.

    Science.gov (United States)

    Nizri, Limor; Vaizel-Ohayon, Dalit; Ben-Amram, Hila; Sharaby, Yehonatan; Halpern, Malka; Mamane, Hadas

    2017-12-15

    We established a molecular method for quantifying ultraviolet (UV) disinfection efficacy using total bacterial DNA in a water sample. To evaluate UV damage to the DNA, we developed the "DNA damage" factor, which is a novel cultivation-independent approach that reveals UV-exposure efficiency by applying a simple PCR amplification method. The study's goal was to prove the feasibility of this method for demonstrating the efficiency of UV systems in the field using flow-through UV reactors. In laboratory-based experiments using seeded bacteria, the DNA damage tests demonstrated a good correlation between PCR products and UV dose. In the field, natural groundwater sampled before and after being subjected to the full-scale UV reactors was filtered, and the DNA extracted from the filtrate was subjected to PCR amplification for a 900-bp fragment of the 16S rRNA gene with initial DNA concentrations of 0.1 and 1 ng/μL. In both cases, the UV dose predicted and explained a significant proportion of the variance in the log inactivation ratio and DNA damage factor. Log inactivation ratio was very low, as expected in groundwater due to low initial bacterial counts, whereas the DNA damage factor was within the range of values obtained in the laboratory-based experiments. Consequently, the DNA damage factor reflected the true performance of the full-scale UV system during operational water flow by using the indigenous bacterial array present in a water sample. By applying this method, we were able to predict with high confidence, the UV reactor inactivation potential. For method validation, laboratory and field iterations are required to create a practical field calibration curve that can be used to determine the expected efficiency of the full-scale UV system in the field under actual operation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Designing a Wien Filter Model with General Particle Tracer

    Science.gov (United States)

    Mitchell, John; Hofler, Alicia

    2017-09-01

    The Continuous Electron Beam Accelerator Facility injector employs a beamline component called a Wien filter which is typically used to select charged particles of a certain velocity. The Wien filter is also used to rotate the polarization of a beam for parity violation experiments. The Wien filter consists of perpendicular electric and magnetic fields. The electric field changes the spin orientation, but also imposes a transverse kick which is compensated for by the magnetic field. The focus of this project was to create a simulation of the Wien filter using General Particle Tracer. The results from these simulations were vetted against machine data to analyze the accuracy of the Wien model. Due to the close agreement between simulation and experiment, the data suggest that the Wien filter model is accurate. The model allows a user to input either the desired electric or magnetic field of the Wien filter along with the beam energy as parameters, and is able to calculate the perpendicular field strength required to keep the beam on axis. The updated model will aid in future diagnostic tests of any beamline component downstream of the Wien filter, and allow users to easily calculate the electric and magnetic fields needed for the filter to function properly. Funding support provided by DOE Office of Science's Student Undergraduate Laboratory Internship program.

  14. Two-components UV-therapy

    International Nuclear Information System (INIS)

    Pullmann, H.; Steigleder, G.K.

    1980-01-01

    20 patients with generalized psoriasis were treated with an apparatus containing UV-A- and UV-B-fluorescence tubes to be switched separately. The therapy was started with an UV-A-dose of 12 J/cm 2 daily. After the first week of treatment UV-B in increasing doses was applicated additionally. Clearance was achieved in 80 percent. (orig.) [de

  15. Digital Simulation of a Hybrid Active Filter - An Active Filter in Series with a Shunt Passive Filter

    OpenAIRE

    Sitaram, Mahesh I; Padiyar, KR; Ramanarayanan, V

    1998-01-01

    Active filters have long been in use for the filtering of power system load harmonics. In this paper, the digital simulation results of a hybrid active power filter system for a rectifier load are presented. The active filter is used for filtering higher order harmonics as the dominant harmonics are filtered by the passive filter. This reduces the rating of the active filter significantly. The DC capacitor voltage of the active filter is controlled using a PI controller.

  16. Numerical study of canister filters with alternatives filter cap configurations

    Science.gov (United States)

    Mohammed, A. N.; Daud, A. R.; Abdullah, K.; Seri, S. M.; Razali, M. A.; Hushim, M. F.; Khalid, A.

    2017-09-01

    Air filtration system and filter play an important role in getting a good quality air into turbo machinery such as gas turbine. The filtration system and filter has improved the quality of air and protect the gas turbine part from contaminants which could bring damage. During separation of contaminants from the air, pressure drop cannot be avoided but it can be minimized thus helps to reduce the intake losses of the engine [1]. This study is focused on the configuration of the filter in order to obtain the minimal pressure drop along the filter. The configuration used is the basic filter geometry provided by Salutary Avenue Manufacturing Sdn Bhd. and two modified canister filter cap which is designed based on the basic filter model. The geometries of the filter are generated by using SOLIDWORKS software and Computational Fluid Dynamics (CFD) software is used to analyse and simulates the flow through the filter. In this study, the parameters of the inlet velocity are 0.032 m/s, 0.063 m/s, 0.094 m/s and 0.126 m/s. The total pressure drop produce by basic, modified filter 1 and 2 is 292.3 Pa, 251.11 Pa and 274.7 Pa. The pressure drop reduction for the modified filter 1 is 41.19 Pa and 14.1% lower compared to basic filter and the pressure drop reduction for modified filter 2 is 17.6 Pa and 6.02% lower compared to the basic filter. The pressure drops for the basic filter are slightly different with the Salutary Avenue filter due to limited data and experiment details. CFD software are very reliable in running a simulation rather than produces the prototypes and conduct the experiment thus reducing overall time and cost in this study.

  17. UV reflection properties of plumage and skin of domesticated turkeys (Meleagris gallopavo f. dom.) as revealed by UV photography.

    Science.gov (United States)

    Bartels, T; Lütgeharm, J-H; Wähner, M; Berk, J

    2017-12-01

    Reflection and fluorescence properties of feathered and non-feathered body regions of white- and bronze-colored fattening turkeys of various ages were examined by ultraviolet (UV) photography. The examinations were carried out on 20 white-feathered fattening turkeys (B.U.T. 6; 10 males, 10 females) and 20 bronze-feathered fattening turkeys (Grelier 708; 10 males, 10 females) over a period of 21 weeks. The turkeys were photographed once a wk under long-wave UV (UVA) radiation illumination (λ = 344-407 nm) using a digital camera. A bandpass filter was used for UV reflectography to filter out the visible components of the used light source. A longpass filter was used for UV fluorescence photography to avoid blurring in the image due to chromatic aberration as a result of UV illumination. We found that natal down feathers of white-feathered turkeys showed an intense yellowish-green fluorescence under UVA light. UVA fluorescence also was shown by the natal downs of the slightly melanized plumage areas of bronze turkeys. Vaned feathers of white fattening turkeys reflected UVA radiation. Freshly molted feathers were optically distinguishable from the previous feather generation due to their more intense UVA reflection. In bronze turkeys, both the bright end seams of the dark pennaceous feathers and rectrices and the bright banding of primary and secondary remiges reflected UVA radiation. Intense UVA fluorescence was recognizable in day-old chicks of both color variants on the scutellate scales of the legs and toes. In male turkeys of both color variants, UVA-reflecting parts were recognizable with increasing age on the featherless head region. The UVA-fluorescent and UVA-reflective characteristics of the plumage of fattening turkeys were closely related to the plumage color, the feather type, the molting state, and the age of the birds. Further research is needed regarding the UVA-reflecting properties of the turkey plumage and the effects of full-spectrum illumination

  18. Filtering Performance Comparison of Kernel and Wavelet Filters for Reactivity Signal Noise

    International Nuclear Information System (INIS)

    Park, Moon Ghu; Shin, Ho Cheol; Lee, Yong Kwan; You, Skin

    2006-01-01

    Nuclear reactor power deviation from the critical state is a parameter of specific interest defined by the reactivity measuring neutron population. Reactivity is an extremely important quantity used to define many of the reactor startup physics parameters. The time dependent reactivity is normally determined by solving the using inverse neutron kinetics equation. The reactivity computer is a device to provide an on-line solution of the inverse kinetics equation. The measurement signal of the neutron density is normally noise corrupted and the control rods movement typically gives reactivity variation with edge signals like saw teeth. Those edge regions should be precisely preserved since the measured signal is used to estimate the reactivity wroth which is a crucial parameter to assure the safety of the nuclear reactors. In this paper, three kind of edge preserving noise filters are proposed and their performance is demonstrated using stepwise signals. The tested filters are based on the unilateral, bilateral kernel and wavelet filters which are known to be effective in edge preservation. The bilateral filter shows a remarkable improvement compared with unilateral kernel and wavelet filters

  19. Criticality safety evaluation report for K Basin filter cartridges

    International Nuclear Information System (INIS)

    Schwinkendorf, K.N.

    1995-01-01

    A criticality safety evaluation of the K Basin filter cartridge assemblies has been completed to support operations without a criticality alarm system. The results show that for normal operation, the filter cartridge assembly is far below the safety limit of k eff = 0.95, which is applied to plutonium systems at the Hanford Site. During normal operating conditions, uranium, plutonium, and fission and corrosion products in solution are continually accumulating in the available void spaces inside the filter cartridge medium. Currently, filter cartridge assemblies are scheduled to be replaced at six month intervals in KE Basin, and at one year intervals in KW Basin. According to available plutonium concentration data for KE Basin and data for the U/Pu ratio, it will take many times the six-month replacement time for sufficient fissionable material accumulation to take place to exceed the safety limit of k eff = 0.95, especially given the conservative assumption that the presence of fission and corrosion products is ignored. Accumulation of sludge with a composition typical of that measured in the sand filter backwash pit will not lead to a k eff = 0.95 value. For off-normal scenarios, it would require at least two unlikely, independent, and concurrent events to take place before the k eff = 0.95 limit was exceeded. Contingencies considered include failure to replace the filter cartridge assemblies at the scheduled time resulting in additional buildup of fissionable material, the loss of geometry control from the filter cartridge assembly breaking apart and releasing the individual filter cartridges into an optimal configuration, and concentrations of plutonium at U/Pu ratios less than measured data for KE Basin, typically close to 400 according to extensive measurements in the sand filter backwash pit and plutonium production information

  20. Herpes zoster - typical and atypical presentations.

    Science.gov (United States)

    Dayan, Roy Rafael; Peleg, Roni

    2017-08-01

    Varicella- zoster virus infection is an intriguing medical entity that involves many medical specialties including infectious diseases, immunology, dermatology, and neurology. It can affect patients from early childhood to old age. Its treatment requires expertise in pain management and psychological support. While varicella is caused by acute viremia, herpes zoster occurs after the dormant viral infection, involving the cranial nerve or sensory root ganglia, is re-activated and spreads orthodromically from the ganglion, via the sensory nerve root, to the innervated target tissue (skin, cornea, auditory canal, etc.). Typically, a single dermatome is involved, although two or three adjacent dermatomes may be affected. The lesions usually do not cross the midline. Herpes zoster can also present with unique or atypical clinical manifestations, such as glioma, zoster sine herpete and bilateral herpes zoster, which can be a challenging diagnosis even for experienced physicians. We discuss the epidemiology, pathophysiology, diagnosis and management of Herpes Zoster, typical and atypical presentations.

  1. Weak and strong typicality in quantum systems.

    Science.gov (United States)

    Santos, Lea F; Polkovnikov, Anatoli; Rigol, Marcos

    2012-07-01

    We study the properties of mixed states obtained from eigenstates of many-body lattice Hamiltonians after tracing out part of the lattice. Two scenarios emerge for generic systems: (i) The diagonal entropy becomes equivalent to the thermodynamic entropy when a few sites are traced out (weak typicality); and (ii) the von Neumann (entanglement) entropy becomes equivalent to the thermodynamic entropy when a large fraction of the lattice is traced out (strong typicality). Remarkably, the results for few-body observables obtained with the reduced, diagonal, and canonical density matrices are very similar to each other, no matter which fraction of the lattice is traced out. Hence, for all physical quantities studied here, the results in the diagonal ensemble match the thermal predictions.

  2. Summary of typical routine maintenance activities at Tokai Reprocessing Plant. Supplement (March, 2002)

    International Nuclear Information System (INIS)

    2002-03-01

    Typical maintenance activities, such as replacement of worn out parts and cleaning of filter elements, routinely performed during steady operation are summarized. [The Summary of Typical Routine Maintenance Activities at Tokai Reprocessing Plant] (JNC TN 8450 2001-006) was already prepared in September, 2001. The purpose of this summary is to give elementary understanding on these activities to people who are responsible for explanation them to the public. At this time, the same kind of summary is prepared as a supplement of the previous one. (author)

  3. Digital Filters for Low Frequency Equalization

    DEFF Research Database (Denmark)

    Tyril, Marni; Abildgaard, J.; Rubak, Per

    2001-01-01

    Digital filters with high resolution in the low-frequency range are studied. Specifically, for a given computational power, traditional IIR filters are compared with warped FIR filters, warped IIR filters, and modified warped FIR filters termed warped individual z FIR filters (WizFIR). The results...... indicate that IIR filters are the most effective in a number of situations....

  4. Metabolic disorders with typical alterations in MRI

    International Nuclear Information System (INIS)

    Warmuth-Metz, M.

    2010-01-01

    The classification of metabolic disorders according to the etiology is not practical for neuroradiological purposes because the underlying defect does not uniformly transform into morphological characteristics. Therefore typical MR and clinical features of some easily identifiable metabolic disorders are presented. Canavan disease, Pelizaeus-Merzbacher disease, Alexander disease, X-chromosomal adrenoleukodystrophy and adrenomyeloneuropathy, mitochondrial disorders, such as MELAS (mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes) and Leigh syndrome as well as L-2-hydroxyglutaric aciduria are presented. (orig.) [de

  5. Enhancement of growth, photosynthetic performance and yield by exclusion of ambient UV components in C3 and C4 plants.

    Science.gov (United States)

    Kataria, Sunita; Guruprasad, K N; Ahuja, Sumedha; Singh, Bupinder

    2013-10-05

    A field experiment was conducted under tropical climate for assessing the effect of ambient UV-B and UV-A by exclusion of UV components on the growth, photosynthetic performance and yield of C3 (cotton, wheat) and C4 (amaranthus, sorghum) plants. The plants were grown in specially designed UV exclusion chambers, wrapped with filters that excluded UV-B (plant species responded to UV exclusion by a significant increase in plant height, leaf area, leaf biomass, total biomass accumulation and yield. Measurements of the chlorophyll, chlorophyll fluorescence parameters, gas exchange parameters and the activity of Ribulose-1,5-bisphosphate carboxylase (Rubisco) by fixation of (14)CO2 indicated a direct relationship between enhanced rate of photosynthesis and yield of the plants. Quantum yield of electron transport was enhanced by the exclusion of UV indicating better utilization of PAR assimilation and enhancement in reducing power in all the four plant species. Exclusion of UV-B in particular significantly enhanced the net photosynthetic rate, stomatal conductance and activity of Rubisco. Additional fixation of carbon due to exclusion of ambient UV-B was channeled towards yield as there was a decrease in the level of UV-B absorbing substances and an increase in soluble proteins in all the four plant species. The magnitude of the promotion in all the parameters studied was higher in dicots (cotton, amaranthus) compared to monocots (wheat, sorghum) after UV exclusion. The results indicated a suppressive action of ambient UV-B on growth and photosynthesis; dicots were more sensitive than monocots in this suppression while no great difference in sensitivity was found between C3 and C4 plants. Experiments indicated the suppressive action of ambient UV on carbon fixation and yield of C3 and C4 plants. Exclusion of solar UV-B will have agricultural benefits in both C3 and C4 plants under tropical climate. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Excimer UV curing in printing

    International Nuclear Information System (INIS)

    Mehnert, R.

    1999-01-01

    It is the aim of this study to investigate the potential of 308 run excimer UV curing in web and sheet fed offset printing and to discuss its present status. Using real-time FTIR-ATR and stationary or pulsed monochromatic (313 nm) irradiation chemical and physical factors affecting the curing speed of printing inks such as nature and concentration of photo-initiators, reactivity of the ink binding system, ink thickness and pigmentation, irradiance in the curing plane, oxygen concentration and nitrogen inerting, multiple pulse exposure, the photochemical dark reaction and temperature dependence were studied. The results were used to select optimum conditions for excimer UV curing in respect to ink reactivity, nitrogen inerting and UV exposure and to build an excimer UV curing unit consisting of two 50 W/cm 308 run excimer lamps, power supply, cooling and inerting unit. The excimer UV curing devices were tested under realistic conditions on a web offset press zirkon supra forte and a sheet fed press Heidelberg GTO 52. Maximum curing speeds of 300 m/min in web offset and 8000 sheets per hour in sheet fed offset were obtained

  7. Characterization of Actin Filament Dynamics during Mitosis in Wheat Protoplasts under UV-B Radiation.

    Science.gov (United States)

    Chen, Huize; Han, Rong

    2016-01-29

    Enhanced ultraviolet-B (UV-B) radiation is caused by the thinning ozone and affects photosynthesis and crop yield. Recently, UV-B radiation has been considered as an environmental signal that regulates plant growth. Elucidating the downstream effectors in UV-B-triggered pathways is of particular interest. Previous studies have shown that actin filaments (AFs) play many roles during cell physiological processes. However, the underlying response of AFs to UV-B radiation remains unclear. In this study, wheat protoplasts were isolated from 7-d-old leaves. The dynamics of AFs during mitosis were observed under different treatments. The protoplasts were treated with UV-B radiation, cytochalasin B (CB) and jasplakinolide (JAS). Ph-FITC labelling results revealed typical actin filament structures in the control group; AFs were rearranged under UV-B radiation. AFs polymerized into bundles during interphase, the preprophase band (PPB) structure was destroyed during prophase, and the AFs gathered into plaques during metaphase in response to UV-B radiation. During anaphase and telophase, the distribution of AFs was dispersed. Pharmacologic experiments revealed that CB induced apoptosis and JAS induced nuclear division without cytokinesis in wheat protoplasts. These results indicated that AFs respond to UV-B radiation during mitosis, supplying evidence of UV-B signal transduction in plants.

  8. Evaluation of DNA damage reversal during medium-pressure UV disinfection.

    Science.gov (United States)

    Poepping, Christopher; Beck, Sara E; Wright, Harold; Linden, Karl G

    2014-06-01

    Ultraviolet (UV) disinfection relies on the principal that DNA exposure to UV irradiation leads to the formation of cytotoxic lesions resulting in the inactivation of microorganisms. Cyclobutane pyrimdine dimers (CPDs) account for the majority of DNA lesions upon UV exposure. Past research has demonstrated reversal of CPDs in extracted DNA formed at high UV-C wavelength irradiation (280 nm) upon subsequent irradiation at lower UVC wavelengths (230-240 nm). Medium-pressure (MP) UV lamps produce a polychromatic emission giving rise to the possibility that cellular DNA in a target pathogen may undergo simultaneous damage and repair when exposed to multiple wavelengths during the disinfection process, decreasing the efficiency of MP UV lamp disinfection. Culture techniques and a quantitative polymerase chain reaction (qPCR) assay were used to examine cell viability and DNA damage reversal. qPCR results indicated direct photoreversal of UV-induced DNA damage through sequential irradiations of 280 nm followed by 228 nm in Escherichia coli DNA. However, significant photoreversal was only observed after high initial doses and secondary doses of UV light. The doses where significant photoreversal took place were more than 10 times higher than those typically used in UV disinfection. Despite evidence of CPD photoreversal, bacterial growth assays showed no indication that sequential-wavelength irradiations result in higher survival rates than single-wavelength irradiations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Effects of UV light disinfection on antibiotic-resistant coliforms in wastewater effluents

    International Nuclear Information System (INIS)

    Meckes, M.C.

    1982-01-01

    Total coliforms and total coliforms resistant to streptomycin, tetracycline, or chloramphenicol were isolated from filtered activated sludge effluents before and after UV light irradiation. Although the UV irradiation effectively disinfected the wastewater effluent, the percentage of the total surviving coliform population resistant to tetracycline or chloramphenicol was significantly higher than the percentage of the total coliform population resistant to those antibiotics before UV irradiation. This finding was attributed to the mechanism of R-factor mediated resistance to tetracycline. No significant difference was noted for the percentage of the surviving total coliform population resistant to streptomycin before or after UV irradiation. Multiple drug resistant to patterns of 300 total coliform isolates revealed that 82% were resistant to two or more antibiotics. Furthermore, 46% of these isolates were capable of transferring antibiotic resistance to a sensitive strain of Escherichia coli

  10. Hydrodynamics of microbial filter feeding

    DEFF Research Database (Denmark)

    Nielsen, Lasse Tor; Asadzadeh, Seyed Saeed; Dölger, Julia

    2017-01-01

    Microbial filter feeders are an important group of grazers, significant to the microbial loop, aquatic food webs, and biogeochemical cycling. Our understanding of microbial filter feeding is poor, and, importantly, it is unknown what force microbial filter feeders must generate to process adequate...... amounts of water. Also, the trade-off in the filter spacing remains unexplored, despite its simple formulation: A filter too coarse will allow suitably sized prey to pass unintercepted, whereas a filter too fine will cause strong flow resistance. We quantify the feeding flow of the filter......-feeding choanoflagellate Diaphanoeca grandis using particle tracking, and demonstrate that the current understanding of microbial filter feeding is inconsistent with computational fluid dynamics (CFD) and analytical estimates. Both approaches underestimate observed filtration rates by more than an order of magnitude...

  11. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2014-01-01

    Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehensively, linearization issues and measurement methods for the characterization of advanced analog filters are introduced in addition. Numerous elaborate illustrations promote an easy comprehension. This book will be of value to engineers and researchers in industry as well as scientists and Ph.D students at universities. The book is also recommendable to graduate students specializing on nanoelectronics, microelectronics ...

  12. Solubilisation de filtres-UV dans des melanges ternaires de phases apolaires, optimisation par l'utilisation de reseaux centres.

    Science.gov (United States)

    Marti-Mestres, G; Laget, J P; Maillols, H; Fernandez, C

    1998-02-01

    This paper is concerned with the solubility of UV filters. Emulsions are perfect formulations used for sunscreens, but to give the skin silky feel without being greasy, the oily phase content is low. Considerations of sunscreen solubility can help to solve specific problems of stability in formulations. It is important to determine what solvent dissolves them and what mixture of solvent improves their solubility. Two water insoluble sunscreens were tested at several concentrations in various non-polar solvents. A strategy with simplex centroid design was used to optimize this work. The graphical interpretation of the data assists our understanding of the solubility of UV filters.

  13. What Is Typical Is Good : The Influence of Face Typicality on Perceived Trustworthiness

    NARCIS (Netherlands)

    Sofer, Carmel; Dotsch, Ron; Wigboldus, Daniel H J; Todorov, Alexander

    2015-01-01

    The role of face typicality in face recognition is well established, but it is unclear whether face typicality is important for face evaluation. Prior studies have focused mainly on typicality’s influence on attractiveness, although recent studies have cast doubt on its importance for attractiveness

  14. A propositional typicality logic for extending rational consequence

    CSIR Research Space (South Africa)

    Booth, R

    2013-08-01

    Full Text Available We introduce Propositional Typicality Logic (PTL), a logic for reasoning about typicality. We do so by enriching classical propositional logic with a typicality operator of which the intuition is to capture the most typical (or normal) situations...

  15. UV detective quantum efficiency measurements

    Science.gov (United States)

    Joseph, Charles L.

    1999-11-01

    We have been testing the vacuum ultraviolet (UV) response of several types of detectors, supporting investigators developing photodiodes made of GaN, near UV photocathodes, and Electron-Bombarded CCDs (EBCCDs). We are currently supporting 4 independent research groups developing GaN most of which have produced devices with significant sensitivity down to 1200 Angstroms. Over the past year, we have also tested bare CCDs with coatings to enhance ultraviolet response. Detectors based on microchannel plate (MCP) have been used extensively for a wide variety of NASA mission and continue to be the standard to beat. Two particularly promising detector technologies are (1) EBCCDs which offer an immediate factor of 3 - 4 improvement in sensitivity and (2) devices made of GaN or GaAlN which may eventually offer factors of 6 - 8 increased sensitivity, both compared to MCPs for wavelengths between 1200 to 3000 Angstroms. We present latest results and plans to expand our vacuum UV testing.

  16. UV imaging in pharmaceutical analysis

    DEFF Research Database (Denmark)

    Østergaard, Jesper

    2018-01-01

    UV imaging provides spatially and temporally resolved absorbance measurements, which are highly useful in pharmaceutical analysis. Commercial UV imaging instrumentation was originally developed as a detector for separation sciences, but the main use is in the area of in vitro dissolution...... and release testing studies. The review covers the basic principles of the technology and summarizes the main applications in relation to intrinsic dissolution rate determination, excipient compatibility studies and in vitro release characterization of drug substances and vehicles intended for parenteral...... administration. UV imaging has potential for providing new insights to drug dissolution and release processes in formulation development by real-time monitoring of swelling, precipitation, diffusion and partitioning phenomena. Limitations of current instrumentation are discussed and a perspective to new...

  17. The Rao-Blackwellized Particle Filter: A Filter Bank Implementation

    Directory of Open Access Journals (Sweden)

    Karlsson Rickard

    2010-01-01

    Full Text Available For computational efficiency, it is important to utilize model structure in particle filtering. One of the most important cases occurs when there exists a linear Gaussian substructure, which can be efficiently handled by Kalman filters. This is the standard formulation of the Rao-Blackwellized particle filter (RBPF. This contribution suggests an alternative formulation of this well-known result that facilitates reuse of standard filtering components and which is also suitable for object-oriented programming. Our RBPF formulation can be seen as a Kalman filter bank with stochastic branching and pruning.

  18. On fractional filtering versus conventional filtering in economics

    Science.gov (United States)

    Nigmatullin, Raoul R.; Omay, Tolga; Baleanu, Dumitru

    2010-04-01

    In this study, we compare the Hodrick-Prescott Filter technique with the Fractional filtering technique that has recently started to be used in various applied sciences like physics, engineering, and biology. We apply these filtering techniques to quarterly GDP data from Turkey for the period 1988:1-2003:2. The filtered series are analyzed using Minimum Square Error (MSE) and real life evidence. In the second part of the study, we use simulated data to analyze the statistical properties of the aforementioned filtering techniques.

  19. Multilevel particle filter

    KAUST Repository

    Law, Kody

    2016-01-06

    This talk will pertain to the filtering of partially observed diffusions, with discrete-time observations. It is assumed that only biased approximations of the diffusion can be obtained, for choice of an accuracy parameter indexed by l. A multilevel estimator is proposed, consisting of a telescopic sum of increment estimators associated to the successive levels. The work associated to O( 2) mean-square error between the multilevel estimator and average with respect to the filtering distribution is shown to scale optimally, for example as O( 2) for optimal rates of convergence of the underlying diffusion approximation. The method is illustrated on some toy examples as well as estimation of interest rate based on real S&P 500 stock price data.

  20. Hydrodynamics of microbial filter feeding

    DEFF Research Database (Denmark)

    Nielsen, Lasse Tor; Asadzadeh, Seyed Saeed; Dölger, Julia

    2017-01-01

    Microbial filter feeders are an important group of grazers, significant to the microbial loop, aquatic food webs, and biogeochemical cycling. Our understanding of microbial filter feeding is poor, and, importantly, it is unknown what force microbial filter feeders must generate to process adequate...

  1. Toward Directly-Deposited Optical Blocking Filters for High-performance, Back-illuminated Imaging X-ray Detectors

    Science.gov (United States)

    Bautz, Mark W.; Kissel, S. E.; Ryu, K.; Suntharalingam, V.

    2014-01-01

    Silicon X-ray detectors require optical blocking filters to prevent out-of-band (UV, visible and near-IR) radiation from corrupting the X-ray signal. Traditionally, blocking filters have been deposited on thin, free-standing membranes suspended over the detector. Free-standing filters are fragile, however, and in past instruments have required heavy and complex vacuum housings to protect them from acoustic loads during ground operations and launch. A directly-deposited blocking filter greatly simplifies the instrument and in principle permits better soft X-ray detection efficiency than a traditional free-standing filter. Directly-deposited filters have flown in previous generation instruments (e.g. the XMM/Newton Reflection Grating Spectrometer) but none has yet been demonstrated on a modern, high-performance back-illuminated X-ray CCD. We report here on the status of our NASA-funded Strategic Astrophysics Technology program to demonstrate such filters.

  2. Matched-Filter Thermography

    Directory of Open Access Journals (Sweden)

    Nima Tabatabaei

    2018-04-01

    Full Text Available Conventional infrared thermography techniques, including pulsed and lock-in thermography, have shown great potential for non-destructive evaluation of broad spectrum of materials, spanning from metals to polymers to biological tissues. However, performance of these techniques is often limited due to the diffuse nature of thermal wave fields, resulting in an inherent compromise between inspection depth and depth resolution. Recently, matched-filter thermography has been introduced as a means for overcoming this classic limitation to enable depth-resolved subsurface thermal imaging and improving axial/depth resolution. This paper reviews the basic principles and experimental results of matched-filter thermography: first, mathematical and signal processing concepts related to matched-fileting and pulse compression are discussed. Next, theoretical modeling of thermal-wave responses to matched-filter thermography using two categories of pulse compression techniques (linear frequency modulation and binary phase coding are reviewed. Key experimental results from literature demonstrating the maintenance of axial resolution while inspecting deep into opaque and turbid media are also presented and discussed. Finally, the concept of thermal coherence tomography for deconvolution of thermal responses of axially superposed sources and creation of depth-selective images in a diffusion-wave field is reviewed.

  3. Controlling flow conditions of test filters in iodine filters

    International Nuclear Information System (INIS)

    Holmberg, R.; Laine, J.

    1979-03-01

    Several different iodine filter and test filter designs and experience gained from their operation are presented. For the flow experiments, an iodine filter system equipped with flow regulating and measuring devices was built. In the experiments the influence of the packing method of the iodine sorption material and the influence of the flow regulating and measuring divices upon the flow conditions in the test filters was studied. On the basis of the experiments it has been shown that the flows through the test filters always can be adjusted to a correct value if there only is a high enough pressure difference available across the test filter ducting. As a result of the research, several different methods are presented with which the flows through the test filters in both operating and future iodine sorption system can easily be measured and adjusted to their correct values. (author)

  4. piSCOPE - A Python based software package for the analysis of volcanic SO2 emissions using UV SO2 cameras

    Science.gov (United States)

    Gliss, J.; Stebel, K.; Kylling, A.; Skauli, T.; Sudbø, A.

    2016-12-01

    In the past years, the use of UV SO2 cameras rapidly increased in importance for the quantification of volcanic SO2 emissions. UV SO2 cameras measure scattered solar UV radiation in two wavelength windows, typically around 310 nm and 330 nm (strong / negligible SO2 absorption) using dichroic filters. The 330 nm filter is to correct for potential spectral broadband variations, for instance due to aerosols. The plume images in both channels are analysed with respect to the ambient sky intensity. The resulting optical density images are converted into SO2 column density (CD) images either using SO2 gas cells or spectral data (e.g. from a DOAS instrument) for calibration. SO2 emission fluxes are then determined along a plume cross section by integrating the product of SO2-CDs and plume speed. piSCOPE (python image analysis Software for Camera Observation of Plume Emissions) is a Python based open source, cross-platform software library for the analysis of SO2 camera data including a GUI application for interactive analysis. The idea and it's main purpose is to provide a common and fully transparent platform based on current analysis standards to encourage scientific exchange and further method development with regard to the analysis of UV SO2 camera data. piSCOPE provides high level convenience functionality and I/O routines for standard image formats and supplementary data (e.g. import of spectral results, live access to volcano database, access to high resolution topography data) as well as fast routines for SO2 flux retrievals. This includes algorithms for geometrical calculations (e.g. distance to plume / topography on a pixel base), image pre-processing (e.g. dark correction, noise reduction), background image modelling, cell and DOAS calibration, a routine for light dilution correction and pixel based plume speed retrievals (optical flow). All algorithms are either based on latest research findings or were newly developed. Thus, piSCOPE is an important step

  5. Group typicality, group loyalty and cognitive development.

    Science.gov (United States)

    Patterson, Meagan M

    2014-09-01

    Over the course of childhood, children's thinking about social groups changes in a variety of ways. Developmental Subjective Group Dynamics (DSGD) theory emphasizes children's understanding of the importance of conforming to group norms. Abrams et al.'s study, which uses DSGD theory as a framework, demonstrates the social cognitive skills underlying young elementary school children's thinking about group norms. Future research on children's thinking about groups and group norms should explore additional elements of this topic, including aspects of typicality beyond loyalty. © 2014 The British Psychological Society.

  6. UV dependent vitamin D syntheses. UV exposure time balancing for optimum production of the vitamins D3 status in the human body. Final report

    International Nuclear Information System (INIS)

    Knuschke, P.; Lehmann, B.; Pueschel, A.; Roensch, H.

    2012-01-01

    UV-dependent vitamin D 3 synthesis - balancing of UV exposure time and the production of an optimal vitamin D 3 status in men The adverse health effects on human skin and eyes by UV radiation have been well known for years. They are known to the public, too. Increased exposures by the UV-B fraction of solar radiation cause e.g. sun burn as an acute skin reaction or an increased risk on skin cancer as a chronic effect. Radiation of the same spectral UV-B range is necessary to induce the essential vitamin D metabolism in men. The UV-induced vitamin D synthesis in the skin supplies the body with more than 90 % while our typical nutrition contributes no more than 10 %. These photobiological effects are diametrically opposed. Therefore, up to now there are contradictory recommendations to the public concerning the health effects of solar UV exposure. The aim of this research project was to evaluate the quantitative and qualitative relations of UV exposure and the vitamin D status in men taking into account different conditions in the population. In result, well-balanced recommendations on optimal UV exposures for the different fractions of the population should be elaborated, realizing health protection aspects against detrimental UV effects. A literature survey (updated in 2011) summarizes the current knowledge on the vitamin D metabolism, on the effects of the hormone vitamin D and on the stage of the current discussion on the optimal vitamin D status. In a number of studies of this project the effects of UV exposure on the vitamin D status (25OH-vitamin D 3 und 1,25OH-vitamin D 3 ) were investigated. Exposure parameters were the photobiologically effective UV dose (with respect to the minimal erythema dose MED = individual sun burn dose in each investigated volunteer) and the extent of the exposed skin area: face and hands (like everyday conditions) or whole body respectively. Serial UV exposures were applied by natural solar UV radiation or by simulated solar

  7. The use of fast digital filters for the processing of scintigraphic pictures

    International Nuclear Information System (INIS)

    Grochulski, W.; Penczek, P.

    1982-01-01

    A brief review of typical methods applied in the development of digital filters for the processing of scintigraphic pictures is given. A simple parametrisation of such filters in the frequency domain is proposed and successfully applied in the case of mathematically simulated IAEA phantoms. The FFT algorithm is used. A possible application of the fast Walsh transform is pointed out. (author)

  8. Instrumental neutron activation analysis of air filter samples

    International Nuclear Information System (INIS)

    Kuykendall, W.E.; Fite, L.E. Jr.; Wainerdi, R.E.

    1974-01-01

    This paper reports the capabilities of automated instrumental neutron activation analysis as demonstrated on 40 air filter samples from Cleveland's area. The results indicate the usefulness of the method in the measurement of elemental concentrations in airborne particulates. Through the use of automated gamma-ray spectrometry procedures, magnetic tape recording of spectral data and computerized processing of data, the method becomes very competitive from the standpoint of sensitivity and cost. The capabilities of the technique for air filter analysis may be summarized as follows: a., over 33 elements are measurable in a filter sample; b., the median detection limit for airborne concentration of an element is approximately 4.10 -9 grams.meter -3 ; c., around 26 elements are detectable in a typical cellulose filter sample; d., the method is non-destructive, therefore the sample can be retained for further analysis. (T.G.)

  9. Sharpening minimum-phase filters

    Science.gov (United States)

    Jovanovic Dolecek, G.; Fernandez-Vazquez, A.

    2013-02-01

    The minimum-phase requirement restricts that filter has all its zeros on or inside the unit circle. As a result the filter does not have a linear phase. It is well known that the sharpening technique can be used to simultaneous improvements of both the pass-band and stop-band of a linear-phase FIR filters and cannot be used for other types of filters. In this paper we demonstrate that the sharpening technique can also be applied to minimum-phase filters, after small modification. The method is illustrated with one practical examples of design.

  10. A Short Note on t-filters, I-filters and Extended Filters on Residuated Lattices

    Czech Academy of Sciences Publication Activity Database

    Víta, Martin

    2015-01-01

    Roč. 271, 15 July (2015), s. 168-171 ISSN 0165-0114 R&D Projects: GA ČR GAP202/10/1826 Institutional support: RVO:67985807 Keywords : t-filters * I-filters * extended filters * residuated lattices Subject RIV: BA - General Mathematics Impact factor: 2.098, year: 2015

  11. Ultraviolet/visible and Fourier transform infrared spectroscopic investigations of organic–inorganic hybrid layers for UV protection

    Energy Technology Data Exchange (ETDEWEB)

    Präfke, Christiane, E-mail: christiane.praefke@iof.fraunhofer.de [Fraunhofer Institute of Applied Optics and Precision Engineering, Optical Coatings Department, Albert-Einstein-Straße 7, 07745 Jena (Germany); Institute of Applied Physics, Abbe Center of Photonics, Friedrich-Schiller-Universität Jena (Germany); Schulz, Ulrike, E-mail: ulrike.schulz@iof.fraunhofer.de [Fraunhofer Institute of Applied Optics and Precision Engineering, Optical Coatings Department, Albert-Einstein-Straße 7, 07745 Jena (Germany); Kaiser, Norbert, E-mail: norbert.kaiser@iof.fraunhofer.de [Fraunhofer Institute of Applied Optics and Precision Engineering, Optical Coatings Department, Albert-Einstein-Straße 7, 07745 Jena (Germany); Tünnermann, Andreas, E-mail: andreas.tuennermann@iof.fraunhofer.de [Fraunhofer Institute of Applied Optics and Precision Engineering, Optical Coatings Department, Albert-Einstein-Straße 7, 07745 Jena (Germany); Institute of Applied Physics, Abbe Center of Photonics, Friedrich-Schiller-Universität Jena (Germany)

    2013-04-01

    A study of vacuum-deposited organic–inorganic hybrid coatings for ultraviolet (UV) protection of polycarbonate is presented. For this purpose, UV-absorbing organic molecules were embedded in a silica matrix by thermal co-evaporation. Typical UV absorbers, namely a benzotriazole, a hydroxyphenyltriazine, and a cyanoacrylate, were used as organic materials. The hybrid layers were investigated by means of ultraviolet/visible (UV/VIS) and Fourier transform infrared spectroscopy (FTIR) concerning their UV/VIS absorption properties and the influence of the silica network on the organic molecules. The porosity and silica–organic interactions are discussed with reference to the infrared spectra. UV irradiation experiments were carried out to demonstrate the UV protection ability of the hybrid layers. Hybrid layers containing the hydroxyphenyltriazine compound showed the best results. - Highlights: ► Vacuum deposited organic–inorganic UV protective coatings for polycarbonate ► Thermal co-evaporation of organic UV absorbing compounds with silica ► Matrix materials and the absorber concentration influence the absorption behavior. ► The coatings on PC show improved UV stability under artificial irradiation. ► The hydroxyphenyltriazine–silica layer shows best UV protection results.

  12. Ultraviolet/visible and Fourier transform infrared spectroscopic investigations of organic–inorganic hybrid layers for UV protection

    International Nuclear Information System (INIS)

    Präfke, Christiane; Schulz, Ulrike; Kaiser, Norbert; Tünnermann, Andreas

    2013-01-01

    A study of vacuum-deposited organic–inorganic hybrid coatings for ultraviolet (UV) protection of polycarbonate is presented. For this purpose, UV-absorbing organic molecules were embedded in a silica matrix by thermal co-evaporation. Typical UV absorbers, namely a benzotriazole, a hydroxyphenyltriazine, and a cyanoacrylate, were used as organic materials. The hybrid layers were investigated by means of ultraviolet/visible (UV/VIS) and Fourier transform infrared spectroscopy (FTIR) concerning their UV/VIS absorption properties and the influence of the silica network on the organic molecules. The porosity and silica–organic interactions are discussed with reference to the infrared spectra. UV irradiation experiments were carried out to demonstrate the UV protection ability of the hybrid layers. Hybrid layers containing the hydroxyphenyltriazine compound showed the best results. - Highlights: ► Vacuum deposited organic–inorganic UV protective coatings for polycarbonate ► Thermal co-evaporation of organic UV absorbing compounds with silica ► Matrix materials and the absorber concentration influence the absorption behavior. ► The coatings on PC show improved UV stability under artificial irradiation. ► The hydroxyphenyltriazine–silica layer shows best UV protection results

  13. Sunglass Filter Transmission and Its Operational Effect in Solar Protection for Civilian Pilots.

    Science.gov (United States)

    Chorley, Adrian C; Lyachev, Andrey; Higlett, Michael P; Khazova, Marina; Benwell, Martin J; Evans, Bruce J W

    2016-05-01

    The ocular effects of excess solar radiation exposure are well documented. Recent evidence suggests that ocular ultraviolet radiation (UVR) exposure to professional pilots may fall outside international guideline limits unless eye protection is used. Nonprescription sunglasses should be manufactured to meet either international or national standards. The mean increase in UVR and blue light hazards at altitude has been quantified and the aim of this research was to assess the effectiveness of typical pilot sunglasses in reducing UVR and blue light hazard exposure in flight. A series of sunglass filter transmittance measurements were taken from personal sunglasses (N = 20) used by pilots together with a series of new sunglasses (N = 18). All nonprescription sunglasses measured conformed to international standards for UVR transmittance and offered sufficient UVR protection for pilots. There was no difference between right and left lenses or between new and used sunglasses. All sunglasses offered sufficient attenuation to counter the mean increase in blue light exposure that pilots experience at altitude, although used sunglasses with scratched lenses were marginally less effective. One pair of prescription sunglasses offered insufficient UVR attenuation for some flights, but would have met requirements of international and national standards for UV-A transmittance. This was likely due to insufficient UVR blocking properties of the lens material. Lenses manufactured to minimally comply with standards for UVR transmittance could result in excess UVR exposure to a pilot based on in-flight irradiance data; an additional requirement of less than 10% transmittance at 380 nm is recommended.

  14. PPCP degradation by UV/chlorine treatment and its impact on DBP formation potential in real waters.

    Science.gov (United States)

    Yang, Xin; Sun, Jianliang; Fu, Wenjie; Shang, Chii; Li, Yin; Chen, Yiwei; Gan, Wenhui; Fang, Jingyun

    2016-07-01

    The ultraviolet/chlorine (UV/chlorine) water purification process was evaluated for its ability to degrade the residues of pharmaceuticals and personal care products (PPCPs) commonly found in drinking water sources. The disinfection byproducts (DBPs) formed after post-chlorination were documented. The performance of the UV/chlorine process was compared with that of the UV/hydrogen peroxide (UV/H2O2) process in treating three types of sand-filtered natural water. Except caffeine and carbamazepine residues, the UV/chlorine process was found to be 59-99% effective for feed water with a high level of dissolved organic carbon and alkalinity, and 27-92% effective for water with a high ammonia content. Both chlorine radicals and hydroxyl radicals were found to contribute to the observed PPCP degradation. The removal efficiencies of chlorine- and UV-resistant PPCPs such as carbamazepine and caffeine were 2-3 times greater than in the UV/H2O2 process in waters not enriched with ammonia. UV/chlorine treatment slightly enhanced the formation chloral hydrate (CH), haloketone (HK) and trichloronitromethane (TCNM). It reduced haloacetonitrile (HAN) formation during the post-chlorination in comparison with the UV/H2O2 process. In waters with high concentrations of ammonia, the UV/chlorine process was only 5-7% more effective than the UV/H2O2 process, and it formed slightly more THMs, HKs and TCNM along with reduced formation of CH and HAN. The UV/chlorine process is thus recommended as a good alternative to UV/H2O2 treatment for its superior PPCP removal without significantly enhancing DBP formation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Vertical flow soil filter for the elimination of micro pollutants from storm and waste water

    DEFF Research Database (Denmark)

    Janzen, Niklas; Banzhaf, Stefan; Scheytt, Traugott

    2009-01-01

    ) to prevent clogging and was spiked with activated sludge to enhance microbial biomass and biodegradation potential. Compounds used as UV filters, antioxidants or plasticizers, namely 4-methylbenzylidene camphor (4-MBC), benzophenone-3 (BP-3), butylated hydroxytoluene (BHT), N-butylbenzenesulfonamide (NBBS...

  16. Near UV Aerosol Group Report

    Science.gov (United States)

    Torres, Omar

    2013-01-01

    2012-13 Report of research on aerosol and cloud remote sensing using UV observations. The document was presented at the 2013 AEROCENTER Annual Meeting held at the GSFC Visitors Center, May 31, 2013. The Organizers of the meeting are posting the talks to the public Aerocentr website, after the meeting.

  17. UV-LED photopolymerised monoliths

    Czech Academy of Sciences Publication Activity Database

    Abele, S.; Nie, F.; Foret, František; Paull, B.; Macka, M.

    2008-01-01

    Roč. 133, č. 7 (2008), s. 864-866 ISSN 0003-2654 R&D Projects: GA AV ČR KAN400310651 Institutional research plan: CEZ:AV0Z40310501 Keywords : photopolymerisation * UV-LED * polymethacrylate monolith Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.761, year: 2008

  18. Cigarette Smoke Cadmium Breakthrough from Traditional Filters: Implications for Exposure

    Science.gov (United States)

    Pappas, R. Steven; Fresquez, Mark R.; Watson, Clifford H.

    2015-01-01

    Cadmium, a carcinogenic metal, is highly toxic to renal, skeletal, nervous, respiratory, and cardiovascular systems. Accurate and precise quantification of mainstream smoke cadmium levels in cigarette smoke is important because of exposure concerns. The two most common trapping techniques for collecting mainstream tobacco smoke particulate for analysis are glass fiber filters and electrostatic precipitators. We observed that a significant portion of total cadmium passed through standard glass fiber filters that are used to trap particulate matter. We therefore developed platinum traps to collect the cadmium that passed through the filters and tested a variety of cigarettes with different physical parameters for quantities of cadmium that passed though the filters. We found less than 1% cadmium passed through electrostatic precipitators. In contrast, cadmium that passed through 92 mm glass fiber filters on a rotary smoking machine was significantly higher, ranging from 3.5% to 22.9% of total smoke cadmium deliveries. Cadmium passed through 44 mm filters typically used on linear smoking machines to an even greater degree, ranging from 13.6% to 30.4% of the total smoke cadmium deliveries. Differences in the cadmium that passed through from the glass fiber filters and electrostatic precipitator could be explained in part if cadmium resides in the smaller mainstream smoke aerosol particle sizes. Differences in particle size distribution could have toxicological implications and could help explain the pulmonary and cardiovascular cadmium uptake in smokers. PMID:25313385

  19. Enhancement of UV absorption behavior in ZnO–TiO2 composites

    Directory of Open Access Journals (Sweden)

    Julián Jiménez Reinosa

    2016-03-01

    Full Text Available The ultraviolet–visible, UV–vis, absorption edge behaviour of semiconductor oxides as TiO2 and ZnO promotes their use as inorganic UV filters for sunscreens. In cosmetics, the use of nanoparticles is favoured because of their higher yield and lower whiteness. However, the particle size effect in the UV absorption is unclear. For this reason, the performances of nano and microsized TiO2 and ZnO are evaluated in both the UV–vis spectroscopy and the Sun Protection Factor, SPF, value. In order to cover the UV range completely by using inorganic filters a new composite is attempted by dry nanodispersion methodology in which TiO2 nanoparticles are dispersed onto ZnO microparticles. The new composite shows superior UV absorbing properties and ca. 60% SPF value due to a synergism between components that resulted in extended UV coverage and reduction of the total amount of nanoparticles required in the sunscreens. In addition, nanoparticles are effectively anchored onto microparticles avoiding the presence of free nanoparticles.

  20. Total ozone derived from UV spectrophotometer measurements on the NASA CV-990 aircraft for the fall 1976 latitude survey flights

    Science.gov (United States)

    Hanser, F. A.

    1977-01-01

    An ultraviolet interference filter spectrophotometer was modified to use a photodiode and was flown on latitude survey flights in the fall of 1976. Comparison with Dobson station total ozone values shows agreement between UVS and Dobson total ozone of + or - 2 percent. The procedure used to convert UVS measured ozone above the aircraft altitude to total ozone above ground level introduces an additional 2 percent deviation for very high altitude UVS ozone data. Under stable aircraft operating conditions, the UVS derived ozone values have a variability, or reproducibility, of better than + or -1 percent. The UVS data from the latitude survey flights yield a detailed latitude profile of total ozone over the Pacific Ocean during November 1976. Significant latitudinal structure in total ozone is found at the middle latitudes (30 deg to 40 deg N and S).

  1. The effect of solar UV radiation of four plant species occurring in a coastal grassland vegetation in The Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Tosserams, M.; Rozema, J. [Vrije Univ., Dept. of Ecology and Ecotoxicology, Amsterdam (Netherlands); Pais, A. de Sa [Univ. de Tras-os-Montes e Alto Douro, Vila Real (Portugal)

    1996-09-01

    During the summer of 1992, growth and some physiological parameters of four native plant species occurring in a coastal grassland in The Netherlands, were studied after reduction of solar UV irradiance using different cut-off filters. Biomass production, morphology and photosynthesis of all species tested were unaffected by the different treatments. Litter production of Plantago lanceolata was increased in the absence of the total UV waveband, indicating a possible role for this waveband in plant senescence. Depletion of the total UV waveband from sunlight resulted in alterations in biomass allocation in Calamagrostis epigeios and Urtica dioica while no changes were observed in P. lanceolatata and Verbascum thapsus. In C. epigeios and increase in the specific leaf area was observed, whereas in U. dioica root weight per total plant weight was decreased resulting in an increase in the shoot/root ratio. Both photosynthetic and UV-absorbing pigment concentrations were altered by the different filter applications. When compared to control plants receiving full sunlight, depletion of UV-B resulted in a significant increase in chlorophyll concentration in U. dioica leaves, this however did not affect photosynthetic rate. The presence of UV-B radiation enhanced the UV-absorbance of leaf extract of all species except P. lanceolata. Optical characteristics of the leaves were also changed. Both the quantity (P. lanceolata and U. dioica) and the quality (all species) of radiation transmitted by the leaves was affected by the different treatments. (au) 44 refs.

  2. An overview of the analytical methods for the determination of organic ultraviolet filters in biological fluids and tissues

    Energy Technology Data Exchange (ETDEWEB)

    Chisvert, Alberto, E-mail: alberto.chisvert@uv.es [Departamento de Quimica Analitica, Facultad de Quimica, Universitat de Valencia, Doctor Moliner St. 50, 46100 Burjassot, Valencia (Spain); Leon-Gonzalez, Zacarias [Unidad Analitica, Instituto de Investigacion Sanitaria Fundacion Hospital La Fe, 46009 Valencia (Spain); Tarazona, Isuha; Salvador, Amparo [Departamento de Quimica Analitica, Facultad de Quimica, Universitat de Valencia, Doctor Moliner St. 50, 46100 Burjassot, Valencia (Spain); Giokas, Dimosthenis [Laboratory of Analytical Chemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina (Greece)

    2012-11-08

    Highlights: Black-Right-Pointing-Pointer Papers describing the determination of UV filters in fluids and tissues are reviewed. Black-Right-Pointing-Pointer Matrix complexity and low amounts of analytes require effective sample treatments. Black-Right-Pointing-Pointer The published papers do not cover the study of all the substances allowed as UV filters. Black-Right-Pointing-Pointer New analytical methods for UV filters determination in these matrices are encouraged. - Abstract: Organic UV filters are chemical compounds added to cosmetic sunscreen products in order to protect users from UV solar radiation. The need of broad-spectrum protection to avoid the deleterious effects of solar radiation has triggered a trend in the cosmetic market of including these compounds not only in those exclusively designed for sun protection but also in all types of cosmetic products. Different studies have shown that organic UV filters can be absorbed through the skin after topical application, further metabolized in the body and eventually excreted or bioaccumulated. These percutaneous absorption processes may result in various adverse health effects, such as genotoxicity caused by the generation of free radicals, which can even lead to mutagenic or carcinogenic effects, and estrogenicity, which is associated with the endocrine disruption activity caused by some of these compounds. Due to the absence of official monitoring protocols, there is a demand for analytical methods that enable the determination of UV filters in biological fluids and tissues in order to retrieve more information regarding their behavior in the human body and thus encourage the development of safer cosmetic formulations. In view of this demand, there has recently been a noticeable increase in the development of sensitive and selective analytical methods for the determination of UV filters and their metabolites in biological fluids (i.e., urine, plasma, breast milk and semen) and tissues. The complexity of

  3. An overview of the analytical methods for the determination of organic ultraviolet filters in biological fluids and tissues

    International Nuclear Information System (INIS)

    Chisvert, Alberto; León-González, Zacarías; Tarazona, Isuha; Salvador, Amparo; Giokas, Dimosthenis

    2012-01-01

    Highlights: ► Papers describing the determination of UV filters in fluids and tissues are reviewed. ► Matrix complexity and low amounts of analytes require effective sample treatments. ► The published papers do not cover the study of all the substances allowed as UV filters. ► New analytical methods for UV filters determination in these matrices are encouraged. - Abstract: Organic UV filters are chemical compounds added to cosmetic sunscreen products in order to protect users from UV solar radiation. The need of broad-spectrum protection to avoid the deleterious effects of solar radiation has triggered a trend in the cosmetic market of including these compounds not only in those exclusively designed for sun protection but also in all types of cosmetic products. Different studies have shown that organic UV filters can be absorbed through the skin after topical application, further metabolized in the body and eventually excreted or bioaccumulated. These percutaneous absorption processes may result in various adverse health effects, such as genotoxicity caused by the generation of free radicals, which can even lead to mutagenic or carcinogenic effects, and estrogenicity, which is associated with the endocrine disruption activity caused by some of these compounds. Due to the absence of official monitoring protocols, there is a demand for analytical methods that enable the determination of UV filters in biological fluids and tissues in order to retrieve more information regarding their behavior in the human body and thus encourage the development of safer cosmetic formulations. In view of this demand, there has recently been a noticeable increase in the development of sensitive and selective analytical methods for the determination of UV filters and their metabolites in biological fluids (i.e., urine, plasma, breast milk and semen) and tissues. The complexity of the biological matrix and the low concentration levels of these compounds inevitably impose sample

  4. Fibrous Filter to Protect Building Environments from Polluting Agents: A Review

    Science.gov (United States)

    Chavhan, Md. Vaseem; Mukhopadhyay, Arunangshu

    2016-04-01

    This paper discusses the use of fibrous filter to protect the building environments from air born polluting agents and especially of concern chemical, biological and radiological agents. Air-filtration includes removal of particulate from air and toxic gases from air. In air filtration, particulate which are mostly biological and radioactive types of agents can be removed by using mechanical and electrostatic filters. Some biological agents, which cannot be removed by air filtration alone, special techniques like antimicrobial finish, UV germicides, coated filters etc. are required. Biocide agent can be added into the fibre itself by grafting reaction to impart antimicrobial activity. Chemical agents like toxic gases can be removed by integrating adsorbents and sorbents in filters or by fibre modifications. It is also possible to impart catalytic conversion properties into the fibre to remove volatile gasous. Radioactive agents can be removed by particulate filter if present in the form of aerosol or by gas cleaning by the use of specific fibre impregnate.

  5. Typicity in Potato: Characterization of Geographic Origin

    Directory of Open Access Journals (Sweden)

    Marco Manzelli

    2010-03-01

    Full Text Available A two-year study was carried out in three regions of Italy and the crop performance and the chemical composition of tubers of three typical potato varieties evaluated. Carbon and nitrogen tuber content was determined by means of an elemental analyzer and the other mineral elements by means of a spectrometer. The same determinations were performed on soil samples taken from experimental areas. The Principal Component Analysis, applied to the results of mineral element tuber analysis, permitted the classification of all potato tuber samples according to their geographic origin. Only a partial discrimination was obtained in function of potato varieties. Some correlations between mineral content in the tubers and in the soil were also detected. Analytical and statistical methods proved to be useful in verifying the authenticity of guaranteed geographical food denominations.

  6. Possible values of UV index in Serbia

    Directory of Open Access Journals (Sweden)

    Letić Milorad

    2008-01-01

    Full Text Available INTRODUCTION UV Index is an indicator of human exposure to solar ultraviolet (UV rays. The numerical values of the UV Index range from 1-11 and above. There are three levels of protection against UV radiation; low values of the UV Index - protection is not required, medium values of the UV Index - protection is recommended and high values of the UV Index - protection is obligatory. The value of the UV Index primarily depends on the elevation of the sun and total ozone column. OBJECTIVE The aim of the study is to determine the intervals of possible maximal annual values of the UV Index in Serbia in order to determine the necessary level of protection in a simple manner. METHOD For maximal and minimal expected values of total column ozone and for maximal elevation of the sun, the value of the UV Index was determined for each month in the Northern and Southern parts of Serbia. These values were compared with the forecast of the UV Index. RESULTS Maximal clear sky values of the UV Index in Serbia for altitudes up to 500m in May, June, July and August can be 9 or even 10, and not less than 5 or 6. During November, December, January and February the UV Index can be 4 at most. During March, April, September and October the expected values of the UV Index are maximally 7 and not less than 3. The forecast of the UV Index is within these limits in 98% of comparisons. CONCLUSION The described method of determination of possible UV Index values showed a high agreement with forecasts. The obtained results can be used for general recommendations in the protection against UV radiation.

  7. Capsid-Damaging Effects of UV Irradiation as Measured by Quantitative PCR Coupled with Ethidium Monoazide Treatment.

    Science.gov (United States)

    Sangsanont, J; Katayama, H; Kurisu, F; Furumai, H

    2014-12-01

    The damage to a viral capsid after low-pressure (LP) and medium-pressure (MP) UV irradiation was assessed, using the quantitative or quantitative reverse transcription PCR coupled with ethidium monoazide treatment (EMA-PCR). After UV irradiation, adenovirus 5 (Ad5) and poliovirus 1 (PV1) were subjected to a plaque assay, PCR, and EMA-PCR to investigate the effect of UV irradiation on viral infectivity, genome damage, and capsid damage, respectively. The effectiveness of UV wavelengths in a viral genome and capsid damage of both PV1 and Ad5 was also further investigated using a band-pass filter. It was found that an MPUV lamp was more effective than an LPUV lamp in inactivating Ad5, whereas there was no difference in the case of PV1. The results of viral reduction determined by PCR and EMA-PCR indicated that MP UV irradiation damaged Ad5 capsid. The damage to PV1 and Ad5 capsid was also not observed after LP UV irradiation. The investigation of effects of UV wavelengths suggested that UV wavelengths at 230-245 nm have greater effects on adenovirus capsid in addition to viral genome than UV wavelengths beyond 245 nm.

  8. UV-generated free radicals (FR) in skin: Their prevention by sunscreens and their induction by self-tanning agents

    Science.gov (United States)

    Jung, K.; Seifert, M.; Herrling, Th.; Fuchs, J.

    2008-05-01

    In the past few years, the cellular effects of ultraviolet (UV) irradiation induced in skin have become increasingly recognized. Indeed, it is now well known that UV irradiation induces structural and cellular changes in all the compartments of skin tissue. The generation of reactive oxygen species (ROS) is the first and immediate consequence of UV exposure and therefore the quantitative determination of free radical reactions in the skin during UV radiation is of primary importance for the understanding of dermatological photodamage. The RSF method (radical sun protection factor) herein presented, based on electron spin resonance spectroscopy (ESR), enables the measurement of free radical reactions in skin biopsies directly during UV radiation. The amount of free radicals varies with UV doses and can be standardized by varying UV irradiance or exposure time. The RSF method allows the determination of the protective effect of UV filters and sunscreens as well as the radical induction capacity of self-tanning agents as dihydroxyacetone (DHA). The reaction of the reducing sugars used in self-tanning products and amino acids in the skin layer (Maillard reaction) leads to the formation of Amadori products that generate free radicals during UV irradiation. Using the RSF method three different self-tanning agents were analyzed and it was found, that in DHA-treated skin more than 180% additional radicals were generated during sun exposure with respect to untreated skin. For this reason the exposure duration in the sun must be shortened when self-tanners are used and photoaging processes are accelerated.

  9. Adaptation of a Filter Assembly to Assess Microbial Bioburden of Pressurant Within a Propulsion System

    Science.gov (United States)

    Benardini, James N.; Koukol, Robert C.; Schubert, Wayne W.; Morales, Fabian; Klatte, Marlin F.

    2012-01-01

    A report describes an adaptation of a filter assembly to enable it to be used to filter out microorganisms from a propulsion system. The filter assembly has previously been used for particulates greater than 2 micrometers. Projects that utilize large volumes of nonmetallic materials of planetary protection concern pose a challenge to their bioburden budget, as a conservative specification value of 30 spores per cubic centimeter is typically used. Helium was collected utilizing an adapted filtration approach employing an existing Millipore filter assembly apparatus used by the propulsion team for particulate analysis. The filter holder on the assembly has a 47-mm diameter, and typically a 1.2-5 micrometer pore-size filter is used for particulate analysis making it compatible with commercially available sterilization filters (0.22 micrometers) that are necessary for biological sampling. This adaptation to an existing technology provides a proof-of-concept and a demonstration of successful use in a ground equipment system. This adaptation has demonstrated that the Millipore filter assembly can be utilized to filter out microorganisms from a propulsion system, whereas in previous uses the filter assembly was utilized for particulates greater than 2 micrometers.

  10. Detector performance for the FIREBall-2 UV experiment

    Science.gov (United States)

    Jewell, April D.; Hamden, Erika T.; Ong, Hwei Ru; Hennessy, John; Goodsall, Timothy; Shapiro, Charles; Cheng, Samuel; Jones, Todd; Carver, Alexander; Hoenk, Michael; Schiminovich, David; Martin, Christopher; Nikzad, Shouleh

    2015-08-01

    We present an overview of the detector for the upcoming Faint Intergalactic Red-shifted Emission Balloon (FIREBall-2) experiment, with a particular focus on the development of device-integrated optical coatings and detector quantum efficiency (QE). FIREBall-2 is designed to measure emission from the strong resonance lines of HI, OVI, and CIV, all red-shifted to 195-225 nm window; its detector is a delta-doped electron multiplying charge coupled device (EM-CCD). Delta-doped arrays, invented at JPL, achieve 100% internal QE from the UV through the visible. External losses due to reflection (~70% in some UV regions) can be mitigated with antireflection coatings (ARCs). Using atomic layer deposition (ALD), thin-film optical filters are incorporated with existing detector technologies. ALD offers nanometer-scale control over film thickness and interface quality, allowing for precision growth of multilayer films. Several AR coatings, including single and multi-layer designs, were tested for FIREBall-2. QE measurements match modeled transmittance behavior remarkably well, showing improved performance in the target wavelength range. Also under development are ALD coatings to enhance QE for a variety of spectral regions throughout the UV (90-320 nm) and visible (320-1000 nm) range both for space-based imaging and spectroscopy as well as for ground-based telescopes.

  11. Multilevel ensemble Kalman filtering

    KAUST Repository

    Hoel, Hakon

    2016-06-14

    This work embeds a multilevel Monte Carlo sampling strategy into the Monte Carlo step of the ensemble Kalman filter (EnKF) in the setting of finite dimensional signal evolution and noisy discrete-time observations. The signal dynamics is assumed to be governed by a stochastic differential equation (SDE), and a hierarchy of time grids is introduced for multilevel numerical integration of that SDE. The resulting multilevel EnKF is proved to asymptotically outperform EnKF in terms of computational cost versus approximation accuracy. The theoretical results are illustrated numerically.

  12. Advances in Collaborative Filtering

    Science.gov (United States)

    Koren, Yehuda; Bell, Robert

    The collaborative filtering (CF) approach to recommenders has recently enjoyed much interest and progress. The fact that it played a central role within the recently completed Netflix competition has contributed to its popularity. This chapter surveys the recent progress in the field. Matrix factorization techniques, which became a first choice for implementing CF, are described together with recent innovations. We also describe several extensions that bring competitive accuracy into neighborhood methods, which used to dominate the field. The chapter demonstrates how to utilize temporal models and implicit feedback to extend models accuracy. In passing, we include detailed descriptions of some the central methods developed for tackling the challenge of the Netflix Prize competition.

  13. Modeling branching pore structures in membrane filters

    Science.gov (United States)

    Sanaei, Pejman; Cummings, Linda J.

    2016-11-01

    Membrane filters are in widespread industrial use, and mathematical models to predict their efficacy are potentially very useful, as such models can suggest design modifications to improve filter performance and lifetime. Many models have been proposed to describe particle capture by membrane filters and the associated fluid dynamics, but most such models are based on a very simple structure in which the pores of the membrane are assumed to be simple circularly-cylindrical tubes spanning the depth of the membrane. Real membranes used in applications usually have much more complex geometry, with interconnected pores which may branch and bifurcate. Pores are also typically larger on the upstream side of the membrane than on the downstream side. We present an idealized mathematical model, in which a membrane consists of a series of bifurcating pores, which decrease in size as the membrane is traversed. Feed solution is forced through the membrane by applied pressure, and particles are removed from the feed either by sieving, or by particle adsorption within pores (which shrinks them). Thus the membrane's permeability decreases as the filtration progresses, ultimately falling to zero. We discuss how filtration efficiency depends on the characteristics of the branching structure. Partial support from NSF DMS 1261596 is gratefully acknowledged.

  14. Do blue-light filtering intraocular lenses affect visual function?

    Science.gov (United States)

    Lavric, Alenka; Pompe, Manca Tekavcic

    2014-11-01

    To study different aspects of visual function, macular changes, and subjective differences between the eye with an ultraviolet (UV) and blue-light filtering intraocular lens (IOL) and the fellow eye with a UV-light filtering IOL. Thirty patients (60 eyes) with senile cataract had both cataracts extracted, and an IOL was implanted at least 2 years before clinical evaluation. In one eye, AcrySof SA60AT (a UV-light filtering IOL) was implanted, whereas in the contralateral eye, AcrySof IQ SN60WF (a blue-light filtering IOL) was implanted. Each patient underwent visual acuity testing, color vision testing (Ishihara and Farnsworth-Munsell 100-hue tests), and contrast sensitivity (CS) testing. The macula was evaluated with optical coherence tomography and with clinical examination. Patients were asked if they noted any difference between the implanted IOLs concerning visual impression. Subjective visual quality was evaluated using the National Eye Institute Visual Functioning Questionnaire. There was a borderline statistically significant difference in the mean best-corrected visual acuity (p = 0.05). As regards color vision, no significant changes in Ishihara and Farnsworth-Munsell 100-hue error scores were detected between both eyes (p = 0.48 and p = 0.59, respectively). Analysis of CS showed no significant difference between the groups at any spatial frequency. There were also no statistically significant differences in central macular thickness and total macular volume between the two IOL groups (p = 0.72 and p = 0.61, respectively). In both IOL groups, three eyes developed an epiretinal membrane, and six eyes developed early signs of age-related macular degeneration. This study showed no significant effects of a blue-light filtering IOL on visual acuity and no influence on color perception and CS. After more than 2 years, there were no significant differences in macular changes between the IOL groups. Clinical evidence of the effect of a blue-light filtering IOL on

  15. UV spectrophotometry of the Metronidazole

    Directory of Open Access Journals (Sweden)

    O. I. Panasenko

    2013-10-01

    Full Text Available Objective. The purpose of this research was to study the UV spectrum of Metronidazole in different polarity solvents (water, 95 % ethanol, 0,1 M sodium hydroxide, 0,1 M hydrochloric acid and 5 M sulfuric acid solution, to establish the relationship between chemical structure of the analyzed compounds and the nature of their electronic spectrum. In addition, a detailed study of the ultraviolet spectra of Metronidazole in different solutions enables to select the optimal wavelength and a thinner design for Metronidazole in substance and dosage forms. Materials and methods. Spectrophotometer SPECORD 200-222U214 has been used for study of the UV spectra of Metronidazole, the quantitative methods were used. Measuring of the absorption of Metronidazole solutions has been carried out in quartz cuvettes with a layer thickness of 10 mm. Due to the fact that the test material shows selective absorption in the ultraviolet spectra, model compounds were studied at a concentration of 1 mg%. Study of electronic spectra was performed in the range of 200 to 400 nm, and the curve has been constructed in coordinates A = f (λ. It has been used water, 95% ethanol, 0,1 M NaOH, 0,1 M HCl and 5 M H2SO4 as solvents. The content of Metronidazole in substance and dosage forms calculated with the equations according to SPU. The results. Study of the UV spectra of Metronidazole and its model compounds showed that in short-wave part of spectrum due to absorption and excitation electrons of imidazole ring were transferred, and in long-wave – conjugation chromophore imidazole cycle and nitro group as electron acceptor occurred. Analysis of the UV spectra of Metronidazole enables to determine a maximum of the analytical quantification of the medicine. Conclusions. Metronidazole UV spectra in water, 95% ethanol, 0,1 M solution of NaOH, 0,1 M solution of HCl and 5 M solution of H2SO4 have been studied. Metronidazole UV spectra are characterized by two absorption bands in the

  16. Evaluation of O{sub 3}UV e H{sub 2}O{sub 2}/UV processes combined with biological activated carbon for reuse refinery waste water; Avaliacao dos processos O{sub 3}UV e H{sub 2}O{sub 2}/UV combinados com carvao ativado granulado com biofilme para reuso de efluentes de refinaria

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Bianca Miguel de; Dezotti, Marcia [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil); Cerqueira, Ana Claudia Figueiras Pereira de [Petroleo Brasileiro S.A. (CENPES/PETROBRAS), Rio de Janeiro, RJ (Brazil). Centro de Pesquisas e Desenvolvimento

    2012-07-01

    The treatment of refinery wastewater by advanced oxidation processes (AOP) coupled with biological activated carbon (BAC) was investigated aiming to generate water for reuse. The Gabriel Passos Refinery wastewater was previously treated in a membrane bioreactor, but still presented a high TOC content (30 mg/L) which may cause biofouling in the subsequent process of reverse osmosis. O3/UV and H2O2/UV processes were employed to oxidize the organic matter and BAC process to remove the residual organic matter from the AOP effluent. AOP promoted oxidation of recalcitrant organic matter as observed by drops on the treated wastewater absorbance and TOC values. BAC filters reached a TOC removal of 65% after 84 days of operation, while GAC filters were saturated after 28 days. Inoculated sand filters were also tested at different flow rates to compare with BAC filters. Low TOC values were achieved by the combined treatment, reaching values around 5 mg/L and allowing water reuse. BAC filters showed to be quite efficient for removal of organic compounds found in biologically treated oil refinery wastewater. (author)

  17. Filter and Filter Bank Design for Image Texture Recognition

    Energy Technology Data Exchange (ETDEWEB)

    Randen, Trygve

    1997-12-31

    The relevance of this thesis to energy and environment lies in its application to remote sensing such as for instance sea floor mapping and seismic pattern recognition. The focus is on the design of two-dimensional filters for feature extraction, segmentation, and classification of digital images with textural content. The features are extracted by filtering with a linear filter and estimating the local energy in the filter response. The thesis gives a review covering broadly most previous approaches to texture feature extraction and continues with proposals of some new techniques. 143 refs., 59 figs., 7 tabs.

  18. Leukodepletion blood filters: filter design and mechanisms of leukocyte removal.

    Science.gov (United States)

    Dzik, S

    1993-04-01

    Modern leukocyte removal filters have been developed after years of refinement in design. Current filters are composite filters in which synthetic microfiber material is prepared as a nonwoven web. The filter material may be surface modified to alter surface tension or charge to improve performance. The housing design promotes effective contact of blood with the filter material and decreases shear forces. The exact mechanisms by which these filters remove leukocytes from blood components are uncertain, but likely represent a combination of both physical and biological processes whose contributions to leukocyte removal are interdependent. Small-pore microfiber webs result in barrier phenomena that permit retention of individual cells and increase the total adsorptive area of the filter. Modifications in surface charge can increase or decrease cell attraction to the fibers. Optimum interfacial surface tensions between blood cells, plasma, and filter fibers not only permit effective blood flow through small fiber pores, but also facilitate cell contact with the material. Barrier retention is a common mechanism for all modern leukocyte-removal filters and applies to all leukocyte subtypes. Because barrier retention does not depend on cell viability, it is operative for cells of any age and will retain any nondeformable cell, including whole nuclei from lymphocytes or monocytes. Barrier retention is supplemented by retention by adhesion. RBCs, lymphocytes, monocytes, granulocytes, and platelets differ in their relative adhesiveness to filter fibers. Different adhesive mechanisms are used in filters designed for RBCs compared with filters designed for platelets. Although lymphocytes, monocytes, and granulocytes can adhere directly to filter fibers, the biological mechanisms underlying cell adhesion may differ for these cell types. These differences may depend on expression of cell adhesion molecules. In the case of filtration of fresh RBCs, platelet-leukocyte interaction

  19. Intelligibility of bandpass filtered speech: The effect of filter types.

    Science.gov (United States)

    Amir, Noam; Kishon-Rabin, Liat

    2017-12-01

    Many studies have examined the contribution of different spectral bands to speech intelligibility, measuring recognition scores of filtered speech stimuli. For a given filter bandwidth, the influence of filter properties on such experiments has been studied mainly with respect to transition band slopes. The objective of the present study was to determine whether nominal transition band slope is a sufficient characterization of filter properties. Several types of