WorldWideScience

Sample records for germicidal uv-irradiated airborne

  1. UV air cleaners and upper-room air ultraviolet germicidal irradiation for controlling airborne bacteria and fungal spores.

    Science.gov (United States)

    Kujundzic, Elmira; Matalkah, Fatimah; Howard, Cody J; Hernandez, Mark; Miller, Shelly L

    2006-10-01

    In-room air cleaners (ACs) and upper-room air ultraviolet germicidal irradiation (UVGI) are engineering control technologies that can help reduce the concentrations of airborne bacteria and fungal spores in the indoor environment. This study investigated six different types of ACs and quantified their ability to remove and/or inactivate airborne bacteria and fungal spores. Four of the air cleaners incorporated UV lamp(s) into their flow path. In addition, the efficacy of combining ACs with upper-room air UVGI was investigated. With the ventilation system providing zero or six air changes per hour, the air cleaners were tested separately or with the upper-room air UVGI system in operation in an 87-m3 test room. Active bacteria cells and fungal spores were aerosolized into the room such that their numbers and physiologic state were comparable both with and without air cleaning and upper-room air UVGI. In addition, the disinfection performance of a UV-C lamp internal to one of the ACs was evaluated by estimating the percentage of airborne bacteria cells and fungal spores captured on the air filter medium surface that were inactivated with UV exposure. Average airborne microbial clean air delivery rates (CADRm) varied between 26-981 m3 hr-1 depending on the AC, and between 1480-2370 m3 hr-1, when using air cleaners in combination with upper-room air UVGI. Culturing, direct microscopy, and optical particle counting revealed similar CADRm. The ACs performed similarly when challenged with three different microorganisms. Testing two of the ACs showed that no additional air cleaning was provided with the operation of an internal UV-C lamp; the internal UV-C lamps, however, inactivated 75% of fungal spores and 97% of bacteria cells captured in the air filter medium within 60 min.

  2. 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

  3. Ultraviolet germicidal irradiation inactivation of airborne fungal spores and bacteria in upper-room air and HVAC in-duct configurations

    Energy Technology Data Exchange (ETDEWEB)

    Kujundzic, E.; Hernandez, M. [Colorado Univ., Boulder, CO (United States). Dept. of Civil, Environmental and Architectural Engineering; Miller, S.L. [Colorado Univ., Boulder, CO (United States). Dept. of Mechanical Engineering

    2007-01-15

    This article presented an evaluation of the efficiency of ultraviolet germicidal irradiation (UVGI) for inactivating airborne fungal spores and bacterial vegetative cells under 3 configurations, namely intrinsic, upper-room air, and in-duct. Several experiments were conducted in a pilot-scale chamber fitted with 4 corner ultraviolet lamps that irradiated the entire chamber; a full-scale room fitted with a UVGI system that irradiated the top 30 cm of the room; and, the supply air duct of a heating ventilation and air-conditioning (HVAC) system. Fungal spores and vegetative cells of bacterium were aerosolized regularly such that their numbers and physiologic state were comparable both with and without the UVGI lamps operating. The article provided information on the materials and methods used including the experimental facilities (pilot-scale chamber, full-scale room, and in-duct UVGI system and ductwork) as well as the methods used for the three experimental studies. It also discussed the bioaerosol generation and sampling and quantification. These included culturing and direct microscopy. UV fluence rate was described. Last, the the results, discussion and conclusions from the studies were presented. It was shown that increasing the air stream velocity through the supply air duct reduces the residence time of bioaerosol being exposed to in-duct UVGI. 36 refs., 3 figs.

  4. A study on UV irradiated HDPE

    International Nuclear Information System (INIS)

    Sang Haibo; Liu Zimin; Wu Shishan; Shen Jian

    2006-01-01

    The structure and properties of HDPE irradiated by ultraviolet (UV) in ozone atmosphere were studied by FT-IR, XPS, gel, and water contact angle test. The oxygen-containing groups such as C=O, C-O and C(=O)O were introduced onto high density polyethylene (HDPE) chains through ultraviolet irradiation in ozone atmosphere, their content increased with the UV irradiation time. Under the same UV irradiation conditions, amount of the oxygen-containing groups introduced in ozone atmosphere was more than that in air atmosphere, indicating that the speed of oxygen-containing groups introduced through UV irradiation in ozone atmosphere was faster than that in air. Therefore, HDPE could be quickly functionalized through UV irradiation in ozone atmosphere. There was no gel formed in the HDPE irradiated in ozone atmosphere. After UV irradiation, the water contact angle of HDPE decreased, and its hydrophilicity was improved, suggesting that the compatibility between the irradiated HDPE and polar polymer or inorganic fillers may be better. Compared with HDPE, the temperature of initial weight loss for irradiated HDPE decreased. The structure and properties of irradiated HDPE/CaCO 3 blend were also investigated. The results showed that the compatibility and interfacial action of the irradiated HDPE/CaCO 3 blend were improved compared to that of HDPE/CaCO 3 blend. The mechanical properties of irradiated HDPE/CaCO 3 blend increased with increasing irradiation time. (authors)

  5. Effect of UV irradiation on cutaneous cicatrices

    DEFF Research Database (Denmark)

    Due, Eva; Rossen, Kristian; Sorensen, Lars Tue

    2007-01-01

    The aim of this study was to examine the effect of ultraviolet (UV) irradiation on human cutaneous cicatrices. In this randomized, controlled study, dermal punch biopsy wounds served as a wound healing model. Wounds healed by primary or second intention and were randomized to postoperative solar UV...... irradiation or to no UV exposure. Evaluations after 5 and 12 weeks included blinded clinical assessments, skin reflectance measurements, histology, immunohistochemistry, and biochemical analyses of the N-terminal propeptide from procollagen-1, hydroxyproline, hydroxylysine, and proline. Twelve weeks...... postoperatively, UV-irradiated cicatrices healing by second intention: (i) were significantly pointed out as the most disfiguring; (ii) obtained significantly higher scores of colour, infiltration and cicatrix area; and (iii) showed significantly higher increase in skin-reflectance measurements of skin...

  6. Increased inactivation of Saccharomyces cerevisiae by protraction of UV irradiation.

    OpenAIRE

    Sommer, R; Haider, T; Cabaj, A; Heidenreich, E; Kundi, M

    1996-01-01

    The principle of equi-effectivity of the product of intensity and exposure time (principle of Bunsen-Roscoe) of UV irradiation has been assumed to be valid for the inactivation of microorganisms in general. Earlier studies claimed higher survival of Escherichia coli B/r with fractionated irradiation compared with single-exposure survival. However, data on the inactivation effect of protraction of UV irradiation are not available. By means of a specially designed UV irradiation apparatus which...

  7. Reconstruction of solar UV irradiance since 1974

    Science.gov (United States)

    Krivova, N. A.; Solanki, S. K.; Wenzler, T.; Podlipnik, B.

    2009-09-01

    Variations of the solar UV irradiance are an important driver of chemical and physical processes in the Earth's upper atmosphere and may also influence global climate. Here we reconstruct solar UV irradiance in the range 115-400 nm over the period 1974-2007 by making use of the recently developed empirical extension of the Spectral And Total Irradiance Reconstruction (SATIRE) models employing Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) data. The evolution of the solar photospheric magnetic flux, which is a central input to the model, is described by the magnetograms and continuum images recorded at the Kitt Peak National Solar Observatory between 1974 and 2003 and by the Michelson Doppler Imager instrument on SOHO since 1996. The reconstruction extends the available observational record by 1.5 solar cycles. The reconstructed Ly-α irradiance agrees well with the composite time series by Woods et al. (2000). The amplitude of the irradiance variations grows with decreasing wavelength and in the wavelength regions of special interest for studies of the Earth's climate (Ly-α and oxygen absorption continuum and bands between 130 and 350 nm) is 1-2 orders of magnitude stronger than in the visible or if integrated over all wavelengths (total solar irradiance).

  8. CaII Κ Imaging to Understand UV Irradiance Variability

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... To identify and understand the underlying physical mechanisms of total solar and UV irradiance variability and to estimate the contribution of various chromospheric features to UV irradiance, detailed analysis of spatially resolved data is required. The various chromospheric features have been segregated ...

  9. Liquid egg white pasteurization using a centrifugal UV irradiator

    Science.gov (United States)

    Studies are lacking on UV nonthermal pasteurization of liquid egg white (LEW). The objective of this study was to inactivate Escherichia coli using a UV irradiator that centrifugally formed a thin film of LEW on the inside of a rotating cylinder. The LEW was inoculated with E. coli K12 to approximat...

  10. Rapid dephosphorylation of p107 following UV irradiation

    NARCIS (Netherlands)

    Voorhoeve, P.M.; Watson, R.J.; Farlie, P.G.; Benett, J.D.; Bernards, R.A.; Lam, E.W.-F.

    1999-01-01

    In response to UV irradiation, mouse NIH3T3 fibroblasts transiently arrest predominantly in the G1 phase of the cell cycle. Here, we investigate the role of the retinoblastoma-related pocket proteins in this biological process. We report here that UV induces an increase in p107/E2F complexes, shown

  11. Wavelength-Dependent Damage to Adenoviral Proteins Across the Germicidal UV Spectrum.

    Science.gov (United States)

    Beck, Sara E; Hull, Natalie M; Poepping, Christopher; Linden, Karl G

    2018-01-02

    Adenovirus, a waterborne pathogen responsible for causing bronchitis, pneumonia, and gastrointestinal infections, is highly resistant to UV disinfection and therefore drives the virus disinfection regulations set by the U.S. Environmental Protection Agency. Polychromatic UV irradiation has been shown to be more effective at inactivating adenovirus and other viruses than traditional monochromatic irradiation emitted at 254 nm; the enhanced efficacy has been attributed to UV-induced damage to viral proteins. This research shows UV-induced damage to adenoviral proteins across the germicidal UV spectrum at wavelength intervals between 200 and 300 nm. A deuterium lamp with bandpass filters and UV light-emitting diodes (UV LEDs) isolated wavelengths in approximate 10 nm intervals. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and image densitometry were used to detect signatures for the hexon, penton, fiber, minor capsid, and core proteins. The greatest loss of protein signature, indicating damage to viral proteins, occurred below 240 nm. Hexon and penton proteins exposed to a dose of 28 mJ/cm 2 emitted at 214 nm were approximately 4 times as sensitive and fiber proteins approximately 3 times as sensitive as those exposed to a dose of 50 mJ/cm 2 emitted at 254 nm. At 220 nm, a dose of 38 mJ/cm 2 reduced the hexon and penton protein quantities to approximately 33% and 31% of the original amounts, respectively. In contrast, a much higher dose of 400 mJ/cm 2 emitted at 261 and 278 nm reduced the original protein quantity to between 66-89% and 80-93%, respectively. No significant damage was seen with a dose of 400 mJ/cm 2 at 254 nm. This research directly correlates enhanced inactivation at low wavelengths with adenoviral protein damage at those wavelengths, adding fundamental insight into the mechanisms of inactivation of polychromatic germicidal UV irradiation for improving UV water disinfection.

  12. Resistance of Aerosolized Bacterial Viruses to Four Germicidal Products.

    Directory of Open Access Journals (Sweden)

    Nathalie Turgeon

    Full Text Available Viral diseases can spread through a variety of routes including aerosols. Yet, limited data are available on the efficacy of aerosolized chemicals to reduce viral loads in the air. Bacteriophages (phages are often used as surrogates for hazardous viruses in aerosol studies because they are inexpensive, easy to handle, and safe for laboratory workers. Moreover, several of these bacterial viruses display physical characteristics similar to pathogenic human and animal viruses, like morphological size, type of nucleic acids, capsid morphology, and the presence of an envelope. In this study, the efficacy of four chemicals was evaluated on four airborne phages at two different relative humidity levels. Non-tailed bacteriophages MS2 (single-stranded RNA, ϕ6 (double-stranded RNA, enveloped, PR772 (double-stranded DNA, and ϕX174 (single-stranded DNA were first aerosolized in a 55L rotative environmental chamber at 19°C with 25% and 50% relative humidity. Then, hydrogen peroxide, Eugenol (phenylpropene used in commercial perfumes and flavorings, Mist® (automobile disinfectant containing Triethylene glycol, and Pledge® (multisurface disinfectant containing Isopropanol, n-Alkyl Dimethyl Benzyl Amonium Chlorides, and n-Alkyl Dimethyl Ethylbenzyl Ammonium Chloride were nebulized with the phages using a separate nebulizer. Aerosols were maintained in suspension during 10 minutes, 1 hour, and 2 hours. Viral aerosols were sampled using an SKC BioSampler and samples were analyzed using qPCR and plaque assays. The resistance levels of the four phages varied depending on the relative humidity (RH and germicidal products tested. Phage MS2 was the most stable airborne virus under the environmental conditions tested while phage PR772 was the least stable. Pledge® and Eugenol reduced the infectivity of all airborne phages tested. At 25% RH, Pledge® and Eugenol were more effective at reducing infectivity of RNA phages ϕ6 and MS2. At 50% RH, Pledge® was the most

  13. Formation of gold nanoparticles in polymethylmethacrylate by UV irradiation

    International Nuclear Information System (INIS)

    Abyaneh, Majid Kazemian; Paramanik, D; Varma, S; Gosavi, S W; Kulkarni, S K

    2007-01-01

    Gold-polymethylmethacrylate (PMMA) nanocomposites were fabricated with a photoreduction method using UV irradiation. The irradiated samples are compared with unirradiated ones to investigate the mechanism of gold nanoparticle formation and the effect of UV irradiation and polymer matrix on the morphology of the particles. The triangular gold nanoparticles were formed in polymer medium at a specific concentration of gold salt and UV exposure. The particle size decreased when the gold salt to polymer ratio was increased. The samples were analysed using UV-Vis spectroscopy, Fourier transform infrared spectrometry, atomic force microscopy, x-ray diffraction, small angle x-ray scattering and x-ray photoelectron spectroscopy. The interfacial interaction of Au nanoparticles and PMMA polymer has been discussed

  14. Plasma polymer films of tetravinylsilane modified by UV irradiation

    Czech Academy of Sciences Publication Activity Database

    Čech, V.; Lichovníková, S.; Trivedi, R.; Peřina, Vratislav; Zemek, Josef; Mikulík, P.; Caha, O.

    2010-01-01

    Roč. 205, Suppl. 1 (2010), S177-S181 ISSN 0257-8972. [Asian-European International Conference on Plasma Surface Engineering/7./ - AEPSE 2009. Busan , 20.09.2009-25.09.2009] Institutional research plan: CEZ:AV0Z10100521; CEZ:AV0Z10480505 Keywords : thin film * PECVD * tetravinylsilane * UV irradiation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.135, year: 2010

  15. Hyaluronan minimizes effects of UV irradiation on human keratinocytes.

    Science.gov (United States)

    Hašová, Martina; Crhák, Tomáš; Safránková, Barbora; Dvořáková, Jana; Muthný, Tomáš; Velebný, Vladimír; Kubala, Lukáš

    2011-05-01

    Exposure to ultraviolet (UV) irradiation has detrimental effects on skin accompanied by the increased metabolism of hyaluronan (HA), a linear polysaccharide important for the normal physiological functions of skin. In this study, the modulation of human keratinocyte response to UVB irradiation by HA (970 kDa) was investigated. Immortalized human keratinocytes (HaCaT) were irradiated by a single dose of UVB and immediately treated with HA for 6 and 24 h. The irradiation induced a significant decrease in the gene expression of CD44 and toll-like receptor 2 6 h after irradiation. The expressions of other HA receptors, including toll-like receptor 4 and the receptor for HA-mediated motility, were not detected in either the control or UVB-irradiated or HA-treated HaCaT cells. UVB irradiation induced a significant decrease in the gene expression of HA synthase-2 and hyaluronidase-2 6 h after irradiation. The expressions of HA synthase-3 and hyaluronidase-3 were not significantly modulated by UV irradiation. Interestingly, HA treatment did not significantly modulate any of these effects. In contrast, HA significantly suppressed UVB-induced pro-inflammatory cytokine release including interleukin-6 and interleukin-8. Similarly, HA treatment reduced the UVB-mediated production of transforming growth factor β1. HA treatment also significantly reduced the UV irradiation-mediated release of soluble CD44 into the media. Finally, HA partially, but significantly, suppressed the UVB-induced decrease in cell viability. Data indicate that HA had significant protective effects for HaCaT cells against UVB irradiation.

  16. Antigen-antibody reactions of UV-irradiated phage DNA

    International Nuclear Information System (INIS)

    Fink, A.

    1976-01-01

    The observation of others could be confirmed that UV-irradiated DNA is a better immunogen than unirradiated DNA. The author's immune sera contained a high amount of antibodies with a specific action against photoproducts in the DNA. The thymine dimer was identified as relevant photoproduct and thus as antigenic determinant. In comparison, the amount of unspecific antibodies reacting with denaturated DNA was low and varied between sera. Thymin-dimer antibodies showed a high specificity without cross-reaction with other pyrimidine dimers such as anti CC and anti CT; they belong to the class of IgG molecules. UV-irradiated dinucleotide dTpT is sufficient to induce the formation of antibodies reacting with the cis-syn thymine dimers in UV-irradiated DNA. Antibody binding is proportional to the UV doses applied to the DNA. When using completely denaturated DNA, there is a linear increase changing into a plateau at higher doses. The extent of antigen-antibody binding is strongly dependent on the degree of denaturation of the DNA. With increasing denaturation, the antibody binding of the DNA increases. The antigen-antibody reaction can thus be used to estimate the degree of denaturation of the DNA. There were no signs of an influence of the degree of denaturation of the DNA on the quantum yield of thymine dimers. The different amounts of antibodies is therefore due to the masking of thymine dimers in native DNA. When irradiating intact phage particles, there was no sign of an influence of the phages' protein covers on the antibody binding capacity of DNA compared with DNA irradiated in vitro. (orig.) [de

  17. UV irradiation alters deoxynucleoside triphosphate pools in Escherichia coli

    International Nuclear Information System (INIS)

    Das, S.K.; Loeb, L.A.

    1984-01-01

    UV irradiation of exponentially growing Escherichia coli increased intracellular concentration of dATP and dTTP without significantly changing the concentrations of dGTP and dCTP. These selective increases in dATP and dTTP pools are seen in wild-type E. coli K12 and AB1157, as well as in recA and umuC strains, and are proportional to UV dose. The possible significance of these findings with respect to induction of the SOS response and nontargeted mutagenesis are discussed. (orig.)

  18. Airborne rhinovirus detection and effect of ultraviolet irradiation on detection by a semi-nested RT-PCR assay.

    Science.gov (United States)

    Myatt, Theodore A; Johnston, Sebastian L; Rudnick, Stephen; Milton, Donald K

    2003-01-13

    Rhinovirus, the most common cause of upper respiratory tract infections, has been implicated in asthma exacerbations and possibly asthma deaths. Although the method of transmission of rhinoviruses is disputed, several studies have demonstrated that aerosol transmission is a likely method of transmission among adults. As a first step in studies of possible airborne rhinovirus transmission, we developed methods to detect aerosolized rhinovirus by extending existing technology for detecting infectious agents in nasal specimens. We aerosolized rhinovirus in a small aerosol chamber. Experiments were conducted with decreasing concentrations of rhinovirus. To determine the effect of UV irradiation on detection of rhinoviral aerosols, we also conducted experiments in which we exposed aerosols to a UV dose of 684 mJ/m2. Aerosols were collected on Teflon filters and rhinovirus recovered in Qiagen AVL buffer using the Qiagen QIAamp Viral RNA Kit (Qiagen Corp., Valencia, California) followed by semi-nested RT-PCR and detection by gel electrophoresis. We obtained positive results from filter samples that had collected at least 1.3 TCID50 of aerosolized rhinovirus. Ultraviolet irradiation of airborne virus at doses much greater than those used in upper-room UV germicidal irradiation applications did not inhibit subsequent detection with the RT-PCR assay. The air sampling and extraction methodology developed in this study should be applicable to the detection of rhinovirus and other airborne viruses in the indoor air of offices and schools. This method, however, cannot distinguish UV inactivated virus from infectious viral particles.

  19. Improved sky imaging for studies of enhanced UV irradiance

    Directory of Open Access Journals (Sweden)

    J. M. Sabburg

    2004-01-01

    Full Text Available A recent World Meteorological Organisation report discussed the importance of continued study of the effect of clouds on the solar UV radiation reaching the earth's surface. The report mentions that the use of all-sky imagery offers the potential to understand and quantify cloud effects more accurately. There are an increasing number of studies investigating the enhancement of surface solar, UV irradiance, and UV actinic flux, using automated CCD and sky imagers. This paper describes new algorithms applicable to a commercially available all-sky imager (TSI-440, for research investigating cloud enhanced spectral UV irradiance. Specifically, these include three new algorithms relating to cloud amount at different spatial positions from 1 zenith and 2 from the solar position and 3 the visible brightness of clouds surrounding the sun. A possible relationship between UV enhancement and the occurrence of near-sun cloud brightness is reported based on this preliminary data. It is found that a range of wavelength dependent intensities, from 306 to 400 nm, can occur in one day for UV enhancements. Evidence for a possible decreasing variation of intensity with longer wavelengths is also presented.

  20. 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.)

  1. Alteration of Paramecium candatum germinal nucleus morphology after UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Fokin, S.I. (Leningradskij Gosudarstvennyj Univ. (USSR). Biologicheskij Nauchno-Issledovatel' skij Inst.)

    1982-09-01

    A study was made on morphologic changes of micronucleus (Mi) after whole-body ultraviolet (UV) irradiation of paramecia as well as after local irradiation of this nucleus or the area of macronucleus (Ma). The whole-body irradiation of its Ma part leads to generative nucleus growth in sizes and chromatin structure change, which is expressed in occurence of large chromatin bodies. Aftereffects of local action on Mi for viable descendants are expressed in nucleus size transformation (usually in reduction), gaining ''comet-shaped'' form and probably in reduction of dna amount. Irradiation of Ma and total effect on cell cause Mi changes of reversible character. All morphologic changes of Mi after local ultraviolet irradiation are conserved in descendants and are not photoreactivated. Possible reasons for this phenomenon are discussed. The results obtained make it possible to speak about different mechanisms of action on Mi in the case of local and whole-body UV irradiation of cell. The effect of irradiated Ma on generative nucleus, but not direct damage of this nucleus is the reason for Mi morphologic reconstruction after whole-body action on paramecium.

  2. The cloud effects on UV irradiance modeled in Antarctica

    International Nuclear Information System (INIS)

    Rafanelli, C.; Anav, A.; Ciattaglia, L.; Di Menno, I.; Di Menno, M.; Araujo, J.; Ochoa, H.; Rodriguez, H.

    2004-01-01

    Full text: The measurement of solar UV radiation in Antarctica is very important in order to obtain information about Ozone level, and many spectro radiometers are installed in the area to perform this task. Usually, their use is very difficult in harsh environment like Southern polar regions, and several multichannel radiometers have been installed. The evaluation of the irradiance and total ozone levels are done using analytical models. A new semi-analytical method to estimate the solar UV irradiance at ground, named WL4UV, was developed. Using spectral irradiance values at 4 selected wavelengths in the UV-B and UV-A regions (305, 320, 340 and 380 nm), the solar UV irradiance at ground is evaluated with low percent of error. The applicability of the method has been tested for clear sky but such conditions are not common in Antarctic. This work investigate the applicability of the WL4UV model under cloudy sky conditions. The 4 irradiance necessary for the model were selected from spectrophotometer Brewer measurements carried out in the Argentinean Belgrano II base (77 degrees 52' S and 34 degrees 38' W). Other tests using spectrophotometers, Brewer and SUV 100, located in Ushuaia, (54 degrees 50' S and 68 degrees 19' W), were also too. This project was funded by the PNRA, IIA-DNA and CADIC for funding and supporting the activities. They thank also all the Brewer operators that in these years spent their time in the management of the instrument. Last but not the least they thank all IIA-DNA personnel for the professional help they put in carrying out the activities in all these years. (author)

  3. Expression of Nudix hydrolase genes in barley under UV irradiation

    Science.gov (United States)

    Tanaka, Sayuri; Sugimoto, Manabu; Kihara, Makoto

    Seed storage and cultivation should be necessary to self-supply foods when astronauts would stay and investigate during long-term space travel and habitation in the bases on the Moon and Mars. Thought the sunlight is the most importance to plants, both as the ultimate energy source and as an environmental signal regulating growth and development, UV presenting the sunlight can damage many aspects of plant processes at the physiological and DNA level. Especially UV-C, which is eliminated by the stratospheric ozone layer, is suspected to be extremely harmful and give a deadly injury to plants in space. However, the defense mechanism against UV-C irradiation damage in plant cells has not been clear. In this study, we investigated the expression of Nudix hydrolases, which defense plants from biotic / abiotic stress, in barley under UV irradiation. The genes encoding the amino acid sequences, which show homology to those of 28 kinds of Nudix hydrolases in Arabidopsis thaliana, were identified in the barley full-length cDNA library. BLAST analysis showed 14 kinds of barley genes (HvNUDX1-14), which encode the Nudix motif sequence. A phylogenetic tree showed that HvNUDX1, HvNUDX7, HvNUDX9 and HvNUDX11 belonged to the ADP-ribose pyrophosphohydrolase, ADP-sugar pyrophosphohydrolase, NAD(P)H pyrophosphohydrolase and FAD pyrophosphohydrolase subfamilies, respectively, HvNUDX3, HvNUDX6, and HvNUDX8 belonged to the Ap _{n}A pyrophosphohydrolase subfamilies, HvNUDX5 and HvNUDX14 belonged to the coenzyme A pyrophosphohydrolase subfamilies, HvNUDX12 and HvNUDX13 belonged to the Ap _{4}A pyrophosphohydrolase subfamilies. Induction of HvNUDX genes by UV-A (340nm), UV-B (312nm), and UV-C (260nm) were analyzed by quantitative RT-PCR. The results showed that HvNUDX4 was induced by UV-A and UV-B, HvNUDX6 was induced by UV-B and UV-C, and HvNUDX7 and HvNUDX14 were induced by UV-C, significantly. Our results suggest that the response of HvNUDXs to UV irradiation is different by UV

  4. Photopatch and UV-irradiated patch testing in photosensitive dermatitis

    Directory of Open Access Journals (Sweden)

    Reena Rai

    2016-01-01

    Full Text Available Background: The photopatch test is used to detect photoallergic reactions to various antigens such as sunscreens and drugs. Photosensitive dermatitis can be caused due to antigens like parthenium, fragrances, rubbers and metals. The photopatch test does not contain these antigens. Therefore, the Indian Standard Series (ISS along with the Standard photopatch series from Chemotechnique Diagnostics, Sweden was used to detect light induced antigens. Aim: To detect light induced antigens in patients with photosensitive dermatitis. Methods: This study was done in a descriptive, observer blinded manner. Photopatch test and ISS were applied in duplicate on the patient's back by the standard method. After 24 hours, readings were recorded according to ICDRG criteria. One side was closed and other side irradiated with 14 J/cm2 of UVA and a second set of readings were recorded after 48 hrs. Result: The highest positivity was obtained with parthenium, with 18 out of 35 (51% patients showing a positive patch test reaction with both photoallergic contact dermatitis and photoaggravation. Four patients (11% showed positive patch test reaction suggestive of contact dermatitis to potassium dichromate and fragrance mix. Six patients had contact dermatitis to numerous antigens such as nickel, cobalt, chinoform and para-phenylenediamine. None of these patients showed photoaggravation on patch testing. Conclusion: Parthenium was found to cause photoallergy, contact dermatitis with photoaggravation and contact allergy. Hence, photopatch test and UV irradiated patch test can be an important tool to detect light induced antigens in patients with photosensitive dermatitis.

  5. Proteolytic activities in yeast after UV irradiation. Pt. 2

    Energy Technology Data Exchange (ETDEWEB)

    Schwencke, J.; Moustacchi, E.

    1982-04-01

    When the levels of three common yeast proteinases in exponentially growing cells of mutants blocked in different repair pathways are compared to that of isogenic wild-type cells, it can be seen that the level of proteinase B is enhanced in the mutants whereas the levels of leucin aminopeptidase (Leu.AP) and lysine aminopeptidase (Lys.AP) are similar in all strains. As in its corresponding wild type, the level of proteinase B activity is further enhanced after UV-irradiation in a mutant blocked in excision-repair (rad1-3). In contrast, following the same treatment the level of proteinase B remains almost constant in a mutant blocked in a general error-prone repair system (rad6-1) and in a mutant defective in a more specific mutagenic repair pathway (pso2-1). Cycloheximide, an inhibitor of protein synthesis, blocks the post-UV enhancement in proteinase B activity observed in rad1-3 indicating that, as in the wild-type cells, an inducible process is involved. The levels of Lys.AP and Leu.AP are, respectively, either unaffected or only moderately increased following UV-treatment of the repair defective mutants, as in wild-type strains.

  6. UVR measurement of a UV germicidal lamp.

    Science.gov (United States)

    Chang, Cheng-Ping; Liu, Hung-Hsin; Peng, Chiung-Yu; Shieh, Jeng-Yueh; Lan, Cheng-Hang

    2007-03-01

    Ultraviolet radiation (UVR) exposure is known to cause serious effects such as conjunctivitis and keratitis in eyes and erythema in skin. The exposure assessment of UVR has not been well established and developed in workplaces due to the lack of suitable UV detecting instruments. Therefore, UV monitoring and measuring procedures were investigated and developed with commercial spectroradiometry devices described in this paper. The UVR irradiance integrated with a biological effective parameter (S lambda) represents the impacts on human skin and eyes as UV effective irradiance. The spectral weighting function derived from the American Conference of Governmental Industrial Hygienists was applied and evaluated to indicate the degree of harmfulness of UVR as a function of wavelength. A portable UV germicidal lamp with short and long wavelengths (254 nm and 365 nm) served as the UVR emission source. The UVR photon count similar to the perceived brightness of a source, irradiance, and effective irradiance (E eff) of the germicidal lamp were measured and analyzed, then the permissible exposure times (T max) were derived for UVR exposure assessment. This monitoring provided a comprehensive approach to detecting UVR magnitude, evaluated the performance of the approach, and quantified the effective exposure based on measured data. From this study, the methodology of UV measurement was established and could be applied to further UVR exposure assessment in the workplace.

  7. Effect of UV-irradiated blood on hemopoiesis in experimental animals

    International Nuclear Information System (INIS)

    Polkanov, V.S.; Kipper, S.N.; Bochkarev, Yu.M.; Khudenskij, Yu.K.

    1986-01-01

    Data on the change in cellular composition of blood of experimental animals under the effect of auto- and alien UV-irradiated blood depending on irradiation dose and the number of courses are presented

  8. SYMBIODINIUM ISOLATES FROM STONY CORAL: ISOLATION, GROWTH CHARACTERISTICS AND EFFECTS OF UV IRRADIATION

    Science.gov (United States)

    Symbiodinium spp. Isolates from Stony Coral: Isolation, Growth Characteristics and Effects of UV Irradiation (Abstract). J. Phycol. 37(3):42-43.Symbiodinium species were isolated from Montipora capitata, Acropora palmata and two field samples of Porites porites. Cultures ...

  9. Metastable hydronium ions in UV-irradiated ice

    International Nuclear Information System (INIS)

    Moon, Eui-Seong; Kang, Heon

    2012-01-01

    We show that the irradiation of UV light (10−11 eV) onto an ice film produces metastable hydronium (H 3 O + ) ions in the ice at low temperatures (53–140 K). Evidence of the presence of metastable hydronium ions was obtained by experiments involving adsorption of methylamine onto UV-irradiated ice films and hydrogen-deuterium (H/D) isotopic exchange reaction. The methylamine adsorption experiments showed that photogenerated H 3 O + species transferred a proton to the methylamine arriving at the ice surface, thus producing the methyl ammonium ion, which was detected by low energy sputtering method. The H 3 O + species induced the H/D exchange of water, which was monitored through the detection of water isotopomers on the surface by using the Cs + reactive ion scattering method. Thermal and temporal stabilities of H 3 O + and its proton migration activity were examined. The lifetime of the hydronium ions in the amorphized ice was greater than 1 h at ∼53 K and decreased to ∼5 min at 140 K. Interestingly, a small portion of hydronium ions survived for an extraordinarily long time in the ice, even at 140 K. The average migration distance of protons released from H 3 O + in the ice was estimated to be about two water molecules at ∼54 K and about six molecules at 100 K. These results indicate that UV-generated hydronium ions can be efficiently stabilized in low-temperature ice. Such metastable hydronium ions may play a significant role in the acid-base chemistry of ice particles in interstellar clouds.

  10. Synthesis and Characterization of Silver/Clay/Chitosan Bionanocomposites by UV-Irradiation Method

    OpenAIRE

    Mansor B. Ahmad; Kamyar Shameli; Majid Darroudi; Wan M.Z.W. Yunus; Nor A. Ibrahim

    2009-01-01

    Problem statement: Silver/Montmorillonite/Chitosan Bionanocomposites (Ag/MMT/Cts BNCs) have been synthesized by UV-irradiation reduction method in the absence of any reducing agent or heat treatment which is used to antibacterial application and medical devices. Approach: MMT, Chitosan and AgNO3 were used as a solid support, stabilizer and silver precursor, respectively. The properties of Ag/MMT/Cts BNCs were studied as a function of UV-irradiation times. The crystalline structure, d-spacing ...

  11. UV irradiation assisted growth of ZnO nanowires on optical fiber surface

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Bo; Shi, Tielin; Liao, Guanglan; Li, Xiaoping; Huang, Jie; Zhou, Temgyuan; Tang, Zirong, E-mail: zirong@mail.hust.edu.cn

    2017-06-01

    Highlights: • A new fabrication process combined a hydrothermal process with UV irradiation from optical fiber is developed. • The growth of ZnO nanowires is efficient in the utilization of UV light. • A novel hybrid structure which integrates ZnO nanowires on optical fiber surface is synthesized. • The UV assisted growth of ZnO nanowires shows preferred orientation and better quality. • A mechanism of growing ZnO nanowires under UV irradiation is proposed. - Abstract: In this paper, a novel approach was developed for the enhanced growth of ZnO nanowires on optical fiber surface. The method combined a hydrothermal process with the efficient UV irradiation from the fiber core, and the effects of UV irradiation on the growth behavior of ZnO nanowires were investigated. The results show that UV irradiation had great effects on the preferred growth orientation and the quality of the ZnO nanowires. The crystallization velocity along the c-axis would increase rapidly with the increase of the irradiation power, while the growth process in the lateral direction was marginally affected by the irradiation. The structure of ZnO nanowires also shows less oxygen vacancy with UV irradiation of higher power. The developed approach is applicable for the efficient growth of nanowires on the fiber surface, and the ZnO nanowires/optical fiber hybrid structures have great potentials for a wide variety of applications such as optical fiber sensors and probes.

  12. Effect of UV irradiation on optical, mechanical and microstructural properties of PVA/NaAlg blends

    Science.gov (United States)

    Sheela, T.; Bhajantri, R. F.; Ravindrachary, V.; Rathod, Sunil G.; Pujari, P. K.; Poojary, Boja; Somashekar, R.

    2014-10-01

    Poly(vinyl alcohol) (PVA)/Sodium alginate (NaAlg) blend films with 60:40 wt% were prepared by solution casting method and subjected to UV irradiation for different intervals of time. The optical, mechanical and morphological properties of the blend films were modified after UV irradiation. The FTIR and FT-Raman results show the chemical interaction between PVA and NaAlg. The UV-vis absorption peak at 278 nm shifts slightly towards longer wavelength and the absorption increases with irradiation time, indicate the increase in crosslinking network. The XRD results show an increase in amorphous nature with increase in UV irradiation time. The DSC/TGA results show a single glass transition temperature (Tg), which confirm that the blends are completely miscible and thermally stable up to 250 °C. The Young's modulus, tensile strength and stiffness of the blend films increase with increase in UV irradiation time. The SEM images confirm that the surface of 48 h UV irradiated PVA:NaAlg blend is more photo-resistant than unirradiated blend.

  13. Effect of UV irradiation on macromolecular synthesis and colony formation in Bacteroides fragilis

    International Nuclear Information System (INIS)

    Schumann, J.P.; Jones, D.T.; Woods, D.R.

    1984-01-01

    Irradiation of Bacteroides fragilis cells with far-UV light resulted in the immediate degradation of DNA which continued for 40 to 60 min. During the degradation phase, DNA synthesis was decreased but was never totally inhibited. DNA degradation after irradiation was inhibited by chloramphenicol and caffeine. DNA synthesis in irradiated cells was reduced by chloramphenicol but resumed after 100 min. Irradiated cells continued to synthesize DNA for 40 min in the presence of caffeine but then DNA synthesis was completely inhibited and never recovered. RNA and protein synthesis were decreased by UV irradiation and the degree of inhibition was proportional to the UV dose. Colony formation was not affected immediately by UV irradiation and continued for a dose-dependent period before inhibition. There was an inverse relationship between UV dose and inhibition of colony formatiom which occurred sooner in cells irradiated with lower doses of UV light. The characteristics of DNA synthesis in B. fragilis cells after UV irradiation differ from those in wild-type Escherichia coli cells, where DNA synthesis is stopped immediately by UV irradiation, but resemble those in E. coli recA mutant cells where extensive degradation occurs following UV irradiation. (author)

  14. Modeling the natural UV irradiation and comparative UV measurements at Moussala BEO (BG)

    Science.gov (United States)

    Tyutyundzhiev, N.; Angelov, Ch; Lovchinov, K.; Nitchev, Hr; Petrov, M.; Arsov, T.

    2018-03-01

    Studies of and modeling the impact of natural UV irradiation on the human population are of significant importance for human activity and economics. The sharp increase of environmental problems – extraordinary temperature changes, solar irradiation abnormalities, icy rains – raises the question of developing novel means of assessing and predicting potential UV effects. In this paper, we discuss new UV irradiation modeling based on recent real-time measurements at Moussala Basic Environmental Observatory (BEO) on Moussala Peak (2925 m ASL) in Rila Mountain, Bulgaria, and highlight the development and initial validation of portable embedded devices for UV-A, UV-B monitoring using open-source software architecture, narrow bandpass UV sensors, and the popular Arduino controllers. Despite the high temporal resolution of the VIS and UV irradiation measurements, the results obtained reveal the need of new assumptions in order to minimize the discrepancy with available databases.

  15. FTIR analysis on aging characteristics of ABS/PC blend under UV-irradiation in air

    Science.gov (United States)

    Li, Jiarong; Chen, Fu; Yang, Long; Jiang, Long; Dan, Yi

    2017-09-01

    Fourier Transform Infrared Spectroscopy (FTIR) is adopted to study the aging characteristics of poly(acrylonitrile-butadiene-styrene)/polycarbonate (ABS/PC) blend under UV-irradiation in air by analyzing the variation of the three main absorbance at about 967 cm- 1, 1720 cm- 1 and 3420 cm- 1 associated with carbon-hydrogen bonds belonging to 1,4 butadiene, carbonyl and hydroxyl groups, respectively. Results indicate that, under UV-irradiation in air, the photo-oxidation of the blend is not a simple combination of the photo-oxidation of corresponding ABS and PC themselves and takes place predominantly at the ABS component. Due to the interaction between the two components and the Fries rearrangement taken place in the PC component during the UV-irradiation in air, the ABS/PC blends behave higher photo-stability than ABS has.

  16. Effect of UV irradiation on the dynamics of oxygen and water interaction with carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Anthony J [Virginia Tech, Blacksburg, VA; Ivanov, Ilia N [ORNL

    2016-01-01

    Carbon nanotube (CNT) films composed of semiconducting single wall nanotubes (s-SWNTs), metallic single wall nanotubes (m-SWNTs), and multiwall nanotubes (MWNTs) were exposed to O2 and H2O vapor in the dark and under UV irradiation. Changes in the film conductivity and mass were measured in situ. We find that UV irradiation increases the resistive response of CNT films to O2 and H2O by more than an order of magnitude. In m-SWNT and MWNT films, UV irradiation changes the sign of the resistive response to O2 and H2O by generating free charge carriers. S-SWNTs show the largest UV-induced resistive response and exhibit weakening of van der Waals interactions with the QCM crystal when exposed to gas/vapor.

  17. Liquid-like behavior of UV-irradiated interstellar ice analog at low temperatures

    Science.gov (United States)

    Tachibana, Shogo; Kouchi, Akira; Hama, Tetsuya; Oba, Yasuhiro; Piani, Laurette; Sugawara, Iyo; Endo, Yukiko; Hidaka, Hiroshi; Kimura, Yuki; Murata, Ken-ichiro; Yurimoto, Hisayoshi; Watanabe, Naoki

    2017-09-01

    Interstellar ice is believed to be a cradle of complex organic compounds, commonly found within icy comets and interstellar clouds, in association with ultraviolet (UV) irradiation and subsequent warming. We found that UV-irradiated amorphous ices composed of H2O, CH3OH, and NH3 and of pure H2O behave like liquids over the temperature ranges of 65 to 150 kelvin and 50 to 140 kelvin, respectively. This low-viscosity liquid-like ice may enhance the formation of organic compounds including prebiotic molecules and the accretion of icy dust to form icy planetesimals under certain interstellar conditions.

  18. Thermal helix-coil transition in UV irradiated collagen from rat tail tendon.

    Science.gov (United States)

    Sionkowska, A; Kamińska, A

    1999-05-01

    The thermal helix-coil transition in UV irradiated collagen solution, collagen film and pieces of rat tail tendon (RTT) were compared. Their thermal stability's were determined by differential scanning calorimeter (DSC) and by viscometric measurements. The denaturation temperatures of collagen solution, film and pieces of RTT were different. The helix-coil transition occur near 40 degrees C in collagen solution, near 112 degrees C in collagen film, and near 101 degrees C in pieces of RTT. After UV irradiation the thermal helix-coil transition of collagen samples were changed. These changes depend on the degree of hydratation.

  19. Liquid-like behavior of UV-irradiated interstellar ice analog at low temperatures.

    Science.gov (United States)

    Tachibana, Shogo; Kouchi, Akira; Hama, Tetsuya; Oba, Yasuhiro; Piani, Laurette; Sugawara, Iyo; Endo, Yukiko; Hidaka, Hiroshi; Kimura, Yuki; Murata, Ken-Ichiro; Yurimoto, Hisayoshi; Watanabe, Naoki

    2017-09-01

    Interstellar ice is believed to be a cradle of complex organic compounds, commonly found within icy comets and interstellar clouds, in association with ultraviolet (UV) irradiation and subsequent warming. We found that UV-irradiated amorphous ices composed of H 2 O, CH 3 OH, and NH 3 and of pure H 2 O behave like liquids over the temperature ranges of 65 to 150 kelvin and 50 to 140 kelvin, respectively. This low-viscosity liquid-like ice may enhance the formation of organic compounds including prebiotic molecules and the accretion of icy dust to form icy planetesimals under certain interstellar conditions.

  20. Restricted growth of human cytomegalovirus in uv-irradiated WI-38 human fibroblasts

    International Nuclear Information System (INIS)

    Furukawa, T.; Tanaka, S.; Plotkin, S.A.

    1975-01-01

    The growth of human CMV was inhibited by uv irradiation of cells prior to infection or during the 48-hr latent period of virus replication but not after virus synthesis began. The duration of uv exposure sufficient to inhibit CMV replication was insufficient to inhibit replication of Herpes simplex and did not prevent uninfected cells from dividing normally. The effect of uv irradiation on CMV replication may have been mediated through prevention of the stimulating effect of the virus on host cell RNA(s) synthesis. (U.S.)

  1. Release of cell coat glycoproteins from the human blood lymphocytes after UV irradiation (254 nm)

    Energy Technology Data Exchange (ETDEWEB)

    Artsishevskaya, R.A.; Mironova, A.P.; Samojlova, K.A. (AN SSSR, Leningrad. Inst. Tsitologii)

    1984-01-01

    Irradiation of the human peripheric blood lymphocytes by UV rays (254 nm) in nonlethal doses is accompanied by the decrease (8-13%) of sorption by them of man's life time of alcyane blue dya which selectively is bound by glycoproteins, glycolipides and acid mucopolysaccharides of cellular surface. As simultaneously the yield from substance cells by some properties similar to glycoproteins is intensified by 9-15%, an assumption is made that from the surface of UV-irradiated lymphocites glycoproteins are disorbed. This effect is discussed in connection with possible primary mechanisms of medical-sanitation effect of UV irradiation.

  2. Structural transformation of CsI thin film photocathodes under exposure to air and UV irradiation

    CERN Document Server

    Tremsin, A S; Siegmund, O H W

    2000-01-01

    Transmission electron microscopy has been employed to study the structure of polycrystalline CsI thin films and its transformation under exposure to humid air and UV irradiation. The catastrophic degradation of CsI thin film photocathode performance is shown to be associated with the film dissolving followed by its re-crystallization. This results in the formation of large lumps of CsI crystal on the substrate surface, so that the film becomes discontinuous and its performance as a photocathode is permanently degraded. No change in the surface morphology and the film crystalline structure was observed after the samples were UV irradiated.

  3. Airborne rhinovirus detection and effect of ultraviolet irradiation on detection by a semi-nested RT-PCR assay

    Directory of Open Access Journals (Sweden)

    Rudnick Stephen

    2003-01-01

    Full Text Available Abstract Background Rhinovirus, the most common cause of upper respiratory tract infections, has been implicated in asthma exacerbations and possibly asthma deaths. Although the method of transmission of rhinoviruses is disputed, several studies have demonstrated that aerosol transmission is a likely method of transmission among adults. As a first step in studies of possible airborne rhinovirus transmission, we developed methods to detect aerosolized rhinovirus by extending existing technology for detecting infectious agents in nasal specimens. Methods We aerosolized rhinovirus in a small aerosol chamber. Experiments were conducted with decreasing concentrations of rhinovirus. To determine the effect of UV irradiation on detection of rhinoviral aerosols, we also conducted experiments in which we exposed aerosols to a UV dose of 684 mJ/m2. Aerosols were collected on Teflon filters and rhinovirus recovered in Qiagen AVL buffer using the Qiagen QIAamp Viral RNA Kit (Qiagen Corp., Valencia, California followed by semi-nested RT-PCR and detection by gel electrophoresis. Results We obtained positive results from filter samples that had collected at least 1.3 TCID50 of aerosolized rhinovirus. Ultraviolet irradiation of airborne virus at doses much greater than those used in upper-room UV germicidal irradiation applications did not inhibit subsequent detection with the RT-PCR assay. Conclusion The air sampling and extraction methodology developed in this study should be applicable to the detection of rhinovirus and other airborne viruses in the indoor air of offices and schools. This method, however, cannot distinguish UV inactivated virus from infectious viral particles.

  4. Transformation of 2,2′,4,4′-tetrabromodiphenyl ether under UV irradiation: Potential sources of the secondary pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ji-Zhong [Exposure and Biomonitoring Division, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, AL: 0800C, EHC, Tunney' s Pasture, Ottawa, Ontario, Canada K1A 0K9 (Canada); Hou, Yuqing [Department of Chemistry and Biochemistry, Southern Illinois University, Mail Code 4405, 1245 Lincoln Drive, Carbondale, IL 62901 (United States); Zhang, Jianshun [Building Energy and Environmental Systems Laboratory, Syracuse University (United States); Zhu, Jiping [Exposure and Biomonitoring Division, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, AL: 0800C, EHC, Tunney' s Pasture, Ottawa, Ontario, Canada K1A 0K9 (Canada); Feng, Yong-Lai, E-mail: yong-lai.feng@hc-sc.gc.ca [Exposure and Biomonitoring Division, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, AL: 0800C, EHC, Tunney' s Pasture, Ottawa, Ontario, Canada K1A 0K9 (Canada)

    2013-12-15

    Highlights: • 2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47) was found transformed to six less brominated BDE analogs under UV irradiation. • BDE-47 was found degraded faster in liquid phase than in gas phase. • Two brominated phenols were formed in the transformation of BDE-47 in gas phase. • The bromine on the ortho positions of the phenyl rings was found lost first to form 2,4,4′-tribromodiphenyl ether (BDE-28). • The more volatile less brominated BDEs are a source of secondary pollutants in the environment. -- Abstract: A commercial brominated flame retardant 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) was used as the model chemical to investigate the degradation and transformation of polybrominated diphenyl ethers (PBDEs) in gas and liquid phases, respectively, under ultraviolet (UV) irradiation. The results showed that BDE-47 can be transformed to less-brominated BDE analogs. A total of six compounds that are less-brominated BDEs and two brominated phenols were observed as transformation products in the reaction mixtures. Different degradation rates of BDE-47 in n-nonane and in isooctane in the same chamber system were observed. Degradation rate of BDE-47 in n-nonane was faster than in isooctane. Under UV irradiation, the bromine on the ortho positions of the phenyl rings was lost first to form 2,4,4′-tribromodiphenyl ether (BDE-28), which then progressively lead to 4,4′-dibromodiphenyl ether (BDE-15) or 2,4′-dibromodiphenyl ether (BDE-8). An airborne transformation pathway has been proposed according to observed transformation products. The more volatile less-brominated BDEs from transformation of BDE-47 are easily evaporated into air to be a source of secondary pollutants in the environment.

  5. The influence of UV-irradiation on thermal and mechanical properties of chitosan and silk fibroin mixtures.

    Science.gov (United States)

    Sionkowska, Alina; Płanecka, Anna; Lewandowska, Katarzyna; Michalska, Marta

    2014-11-01

    In the present paper the results regarding the influence of UV-irradiation with 254 nm wavelength on the thermal and mechanical properties and the intrinsic viscosity of chitosan/silk fibroin mixtures are presented. The mixture of chitosan and silk fibroin in solution and thin films made of chitosan/silk fibroin mixture obtained by solvent evaporation were submitted to the treatment with UV irradiation (wavelength 254 nm) for different time intervals. Mechanical properties of thin films made of chitosan/silk fibroin blends before and after UV-irradiation have been investigated by mechanical testing machine and compared with mechanical properties of chitosan films. The changes in such mechanical properties as ultimate breaking strength, percentage of elongation at break and Young Modulus have been investigated. The results have shown, that the mechanical properties of the blends were greatly affected by time of exposure to UV irradiation. Ultimate tensile strength and ultimate percentage of elongation decreased after UV irradiation of the blend. Increasing UV irradiation led to the decrease in Young's Modulus of the chitosan/silk fibroin blend. Viscosity of chitosan/silk fibroin mixtures decreased after UV-irradiation. Thermal properties of the mixtures have been only slightly altered by UV-irradiation. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Treating cell culture media with UV irradiation against adventitious agents: minimal impact on CHO performance.

    Science.gov (United States)

    Yen, Sandi; Sokolenko, Stanislav; Manocha, Bhavik; Blondeel, Eric J M; Aucoin, Marc G; Patras, Ankit; Daynouri-Pancino, Farnaz; Sasges, Michael

    2014-01-01

    Sterility of cell culture media is an important concern in biotherapeutic processing. In large scale biotherapeutic production, a unit contamination of cell culture media can have costly effects. Ultraviolet (UV) irradiation is a sterilization method effective against bacteria and viruses while being non-thermal and non-adulterating in its mechanism of action. This makes UV irradiation attractive for use in sterilization of cell culture media. The objective of this study was to evaluate the effect of UV irradiation of cell culture media in terms of chemical composition and the ability to grow cell cultures in the treated media. The results showed that UV irradiation of commercial cell culture media at relevant disinfection doses impacted the chemical composition of the media with respect to several carboxylic acids, and to a minimal extent, amino acids. The cumulative effect of these changes, however, did not negatively influence the ability to culture Chinese Hamster Ovary cells, as evaluated by cell viability, growth rate, and protein titer measurements in simple batch growth compared with the same cells cultured in control media exposed to visible light. © 2014 The Authors. Published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers.

  7. Fullerene-catalyzed reduction of azo derivatives in water under UV irradiation

    KAUST Repository

    Guo, Yong

    2012-09-27

    Metal-free fullerene (C60) was found to be an effective catalyst for the reduction of azo groups in basic aqueous solution under UV irradiation in the presence of NaBH4. Use of NaBH4 by itself is not sufficient to reduce the azo dyes without the assistance of a metal catalyst such as Pd and Ag. Experimental and theoretical results suggest that C 60 catalyzes this reaction by using its vacant orbital to accept the electron in the bonding orbital of azo dyes, which leads to the activation of the N=N bond. UV irradiation increases the ability of C60 to interact with electron-donor moieties in azo dyes. Filling a vacancy: Experimental and theoretical methods have been combined to show that C60-catalyzed reductions of azo compounds form aromatic amines under UV irradiation (see scheme). The obtained results show that C60 acts as an electron acceptor to catalyze the reduction of azo compounds, and the role of UV irradiation is to increase the ability of C60 to interact with electron-donor moieties in azo compounds. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Assays of residual antibiotics after treatment of γ-ray and UV irradiation

    International Nuclear Information System (INIS)

    Shin, Ji Hye; Nam, Ji Hyun; Lee, Dong Hun; Yu, Seung Ho; Lee, Myun Joo

    2010-01-01

    The pollution of antibiotics is a major cause of spreading antibiotics resistant bacteria in the environment. Applications of ozonation, UV, and γ-ray irradiations have been introduced to remove antibiotics in the effluents from wastewater treatment system. In this study, we compared the chemical (HPLC) and biological (antimicrobial susceptibility test, AMS) assays in measuring of the concentrations of residual antibiotics after γ-ray and UV irradiation. Most samples were degraded by γ-ray irradiation (1 ∼ 2 kGy). However, lincomycin and tetracycline were not degraded by UV irradiation. The concentration of residual antibiotics, that was treated with γ-ray and UV irradiation, measuring by bioassay was similar to HPLC. The concentrations of γ-ray irradiated cephradine measured by AMS test were 2 times higher than of HPLC assay, indicating AMS test is more sensitive than HPLC assay. These results indicate that γ-ray irradiation technique is more useful than UV irradiation, and biological assay is more useful to detect the antibiotics and toxic intermediates in antibiotics degradation

  9. Homology and repair of UV-irradiated plasmid DNA in Haemophilus influenzae

    International Nuclear Information System (INIS)

    Cabrea-Juarez, E.; Setlow, J.K.

    1983-01-01

    UV-irradiated plasmid pNov1 containing a cloned fragment of chromosomal DNA could be repaired by excision, but plasmid p2265 without homology to the chromosome could not. Establishment of pNov1 was more UV resistant in Rec - than in Rec + cells. 19 references, 2 figures

  10. Structural Evolution of Human Recombinant alfaB-Crystallin under UV Irradiation

    DEFF Research Database (Denmark)

    Sugiyama, Masaaki; Fujii, Noriko; Morimoto, Yukio

    2008-01-01

    External stresses cause certain proteins to lose their regular structure and aggregate. In order to clarify this abnormal aggregation process, a structural evolution of human recombinant aB-crystallin under UV irradiation was observed with in situ small-angle neutron scattering. The abnormal...

  11. Screening of UV-irradiated and S-2-aminoethyl-Lcysteine resistant ...

    African Journals Online (AJOL)

    The screening of UV irradiated and aminoethyl-l-cysteine resistant (AECR) mutants of Bacillus megaterium strains for improved lysine accumulation was conducted. The mutants, MR-10 and MR-25 derived form irradiated cultures of B. megaterium SP 76, and MS-3 and MS-5 derived form B. megaterium SP 86 produced ...

  12. COMPARATIVE DISINFECTION EFFICIENCY OF PULSED AND CONTINUOUS-WAVE UV IRRADIATION TECHNOLOGIES

    Science.gov (United States)

    Pulsed UV (PUV) is novel UV irradiation system that is a non-mercury lamp based alternative to currently used continuous-wave systems for water disinfection. To compare the polychromatic PUV irradiation disinfection efficiency with that from continuous wave monochromatic low-pre...

  13. Soaps and Germicides as Adjunct Topical Antimycotic Agents on ...

    African Journals Online (AJOL)

    Objective: The study aims at evaluating the potentials of soaps and germicides / disinfectants as adjunct topical anti-vulvovaginal candidasis agents. Methods: In vitro inhibitory activities of the test agents, prepared according to the manufacturer's specification for toilet and midwifery purposes were determined using modified ...

  14. Bactericidal and antimicrobial effects of pure titanium and titanium alloy treated with short-term, low-energy UV irradiation.

    Science.gov (United States)

    Itabashi, T; Narita, K; Ono, A; Wada, K; Tanaka, T; Kumagai, G; Yamauchi, R; Nakane, A; Ishibashi, Y

    2017-02-01

    The surface of pure titanium (Ti) shows decreased histocompatibility over time; this phenomenon is known as biological ageing. UV irradiation enables the reversal of biological ageing through photofunctionalisation, a physicochemical alteration of the titanium surface. Ti implants are sterilised by UV irradiation in dental surgery. However, orthopaedic biomaterials are usually composed of the alloy Ti6Al4V, for which the antibacterial effects of UV irradiation are unconfirmed. Here we evaluated the bactericidal and antimicrobial effects of treating Ti and Ti6Al4V with UV irradiation of a lower and briefer dose than previously reported, for applications in implant surgery. Ti and Ti6Al4V disks were prepared. To evaluate the bactericidal effect of UV irradiation, Staphylococcus aureus 834 suspension was seeded onto the disks, which were then exposed to UV light for 15 minutes at a dose of 9 J/cm 2 . To evaluate the antimicrobial activity of UV irradiation, bacterial suspensions were seeded onto the disks 0, 0.5, one, six, 24 and 48 hours, and three and seven days after UV irradiation as described above. In both experiments, the bacteria were then harvested, cultured, and the number of colonies were counted. No colonies were observed when UV irradiation was performed after the bacteria were added to the disks. When the bacteria were seeded after UV irradiation, the amount of surviving bacteria on the Ti and Ti6Al4V disks decreased at 0 hours and then gradually increased. However, the antimicrobial activity was maintained for seven days after UV irradiation. Antimicrobial activity was induced for seven days after UV irradiation on both types of disk. Irradiated Ti6Al4V and Ti had similar antimicrobial properties. Cite this article: T. Itabashi, K. Narita, A. Ono, K. Wada, T. Tanaka, G. Kumagai, R. Yamauchi, A. Nakane, Y. Ishibashi. Bactericidal and antimicrobial effects of pure titanium and titanium alloy treated with short-term, low-energy UV irradiation. Bone Joint

  15. DNA repair in gamma-and UV-irradiated Escherichia coli treated with caffeine and acriflavine

    International Nuclear Information System (INIS)

    Zhestyanikov, V.D.; Savel'eva, G.E.

    1978-01-01

    A study is made of the postradiation effect of caffeine and acriflavine on the survival rate and DNA repair in E. coli exposed to γ- and UV-radiation. When added to postradiation growth medium caffeine and acriflavine lower the survival rate of γ-irradiated radioresistant strains, B/r and Bsub(s-1)γR, and UV-irradiated UV-resistant strain B/r, and do not appreciably influence the survival of strains that are sensitive to γ- and UV-radiation. The survival rate of UV-irradiated mutant BsUb(s-1) somewhat increases in the presence of caffeine. Caffeine and acriflavine inhibit repair of single-stranded DNA breaks induced in strain B/r by γ-radiation (slow repair) and UV light. Acriflavine arrests a recombination branch of postreplication repair of DNA in E. coli Bsub(s-1)γR Whereas caffeine does not influence this process

  16. Inhibition of IL-1 activity induced with allogeneic transfusion of UV-irradiated blood

    International Nuclear Information System (INIS)

    Horvat, B.; Poljak-Blazi, M.; Hadija, M.

    1991-01-01

    Treatment with UV-irradiated donor-specific blood transfusion is known to induce specific unresponsiveness in recipient animals and prolong allograft survival. Mixed lymphocyte response in transfused mice was decreased towards spleen cells of the blood donor strain, but was not altered to third-party cells. Sera from treated mice showed significantly lower interleukin-1 (IL-1) activity, which was increased with higher dilutions of sera, indicating the presence of IL-1 inhibitor. Furthermore, sera decreased rIL-1-induced cell proliferation in dose-dependent manner, while the response to rIL-2 neither depended on the concentration of sera, nor differed between non-treated controls and treated mice. These results indicate that UV-irradiated allogeneic blood transfusion could induce an inhibitor, specifically directed to IL-1 activity, which may be involved in the generation of immunological unresponsiveness in treated animals. (author)

  17. UV irradiance and albedo at Union Glacier Camp (Antarctica: a case study.

    Directory of Open Access Journals (Sweden)

    Raul R Cordero

    Full Text Available We report on the first spectral measurements of ultraviolet (UV irradiance and the albedo at a Camp located in the southern Ellsworth Mountains on the broad expanse of Union Glacier (700 m altitude, 79° 46' S; 82° 52'W; about 1,000 km from the South Pole. The measurements were carried out by using a double monochromator-based spectroradiometer during a campaign (in December 2012 meant to weight up the effect of the local albedo on the UV irradiance. We found that the albedo measured at noon was about 0.95 in the UV and the visible part of the spectrum. This high surface reflectivity led to enhancements in the UV index under cloudless conditions of about 50% in comparison with snow free surfaces. Spectral measurements carried out elsewhere as well as estimates retrieved from the Ozone Monitoring Instrument (OMI were used for further comparisons.

  18. Modelling UV irradiances on arbitrarily oriented surfaces: effects of sky obstructions

    Directory of Open Access Journals (Sweden)

    M. Hess

    2008-07-01

    Full Text Available A method is presented to calculate UV irradiances on inclined surfaces that additionally takes into account the influence of sky obstructions caused by obstacles such as mountains, houses, trees, or umbrellas. With this method it is thus possible to calculate the impact of UV radiation on biological systems, such as, for instance, the human skin or eye, in any natural or artificial environment. The method, which consists of a combination of radiation models, is explained here and the accuracy of its results is demonstrated. The effect of a natural skyline is shown for an Alpine ski area, where the UV irradiance even on a horizontal surface may increase due to reflection from snow by more than 10 percent. In contrast, in a street canyon the irradiance on a horizontal surface is reduced to 30% in shadow and to about 75% for a position in the sun.

  19. Modelling UV irradiances on arbitrarily oriented surfaces: effects of sky obstructions

    Science.gov (United States)

    Hess, M.; Koepke, P.

    2008-07-01

    A method is presented to calculate UV irradiances on inclined surfaces that additionally takes into account the influence of sky obstructions caused by obstacles such as mountains, houses, trees, or umbrellas. With this method it is thus possible to calculate the impact of UV radiation on biological systems, such as, for instance, the human skin or eye, in any natural or artificial environment. The method, which consists of a combination of radiation models, is explained here and the accuracy of its results is demonstrated. The effect of a natural skyline is shown for an Alpine ski area, where the UV irradiance even on a horizontal surface may increase due to reflection from snow by more than 10 percent. In contrast, in a street canyon the irradiance on a horizontal surface is reduced to 30% in shadow and to about 75% for a position in the sun.

  20. A thermal after-effect of UV irradiation of muscle glycogen phosphorylase b.

    Directory of Open Access Journals (Sweden)

    Valeriya V Mikhaylova

    Full Text Available Different test systems are used to characterize the anti-aggregation efficiency of molecular chaperone proteins and of low-molecular-weight chemical chaperones. Test systems based on aggregation of UV-irradiated protein are of special interest because they allow studying the protective action of different agents at physiological temperatures. The kinetics of UV-irradiated glycogen phosphorylase b (UV-Phb from rabbit skeletal muscle was studied at 37°C using dynamic light scattering in a wide range of protein concentrations. It has been shown that the order of aggregation with respect to the protein is equal to unity. A conclusion has been made that the rate-limiting stage of the overall process of aggregation is heat-induced structural reorganization of a UV-Phb molecule, which contains concealed damage.

  1. In-situ investigation of graphene oxide under UV irradiation: Evolution of work function

    Directory of Open Access Journals (Sweden)

    Jun Li

    2015-06-01

    Full Text Available Using in-situ Kelvin probe force microscopy (KPFM to measure surface potential, we investigated the time-dependent work function evolution of solution-processed graphene oxide (GO under ultraviolet (UV irradiation. We found that the work function of GO exposed in UV shows a notable decrease with increasing irradiation time, which is proposed to be attributed to the gradual disappearance of oxygen-containing functional groups in GO during the UV-induced reduction reaction process. Fourier transform infrared spectrum and Raman spectrum were used to confirm the reduction of GO under UV irradiation. Our study would give an insight into understanding the transformation of GO’s electronic structures during the reduction process.

  2. UV irradiation as a tool for obtaining asymmetric somatic hybrids between Nicotiana plumbaginifolia and Lycopersicon esculentum

    International Nuclear Information System (INIS)

    Vlahova, M.; Hinnisdaels, S.; Frulleux, F.; Claeys, M.; Atanassov, A.; Jacobs, M.

    1997-01-01

    UV-irradiated kanamycin-resistant Lycopersicon esculentum leaf protoplasts were fused with wild-type Nicotiana plumbaginifolia leaf protoplasts. Hybrid calli were recovered after selection in kanamycin-containing medium and subsequently regenerated. Cytological analysis of these regenerants showed that several (2–4) tomato chromosomes, or chromosome fragments, were present in addition to a polyploid Nicotiana genome complement. All lines tested had neomycin phosphotransferase (NPTII) activity and the presence of the kanamycin gene was shown by Southern blotting. In two cases a different hybridization profile for the kanamycin gene, compared to the tomato donor partner, was observed, suggesting the occurence of intergenomic recombination events. The hybrid nature of the regenerants was further confirmed by Southernblotting experiments using either a ribosomal DNA sequence or a tomato-specific repeat as probes. The hybrids were partially fertile and some progeny could be obtained. Our results demonstrate that UV irradiation is a valuable alternative for asymmetric cell-hybridization experiments. (author)

  3. Study of maleic anhydride and styrene grafted onto polypropylene induced by UV irradiation

    International Nuclear Information System (INIS)

    Li Zhenzhong; He Wei; Guo Hongjun; Zhang Wenxiong; Ma Yalin

    2007-01-01

    Maleic anhydride (MAH) and styrene (St) grafted onto polypropylene (PP) were prepared by UV irradiation. Effects of the irradiation time, monomer and initiator content on the grafting rate and melt flow rate (MFR) were studied. The results show that the optimal duration of UV irradiation is 30s. The grafting rate increases with initiator content when initiator content less than 0.6 phr, the MFR value of grafted PP reaches the highest point when benzophenone (BP) content is 0.4 phr. The content of MAH and St have an effect on the grafting rate and MFR value of the grafted PP, and the optimal contents of monomer is 4 phr. The existence of St as a comonomer reduces apparently the MFR value of grafted PP greatly. Grafted PP present significant changes in crystallization and fusion peaks, indicating differences in crystal size and formation after grafting reaction. (authors)

  4. Exacerbation of lupus erythematodes visceralis as a result of UV irradiation - a hypothesis

    International Nuclear Information System (INIS)

    Diezel, W.; Meffert, H.; Guenther, W.; Huse, K.; Soennichsen, N.

    1979-01-01

    In the culture medium of human fibroblasts a proteolytic activity is evident after UV irradiation (290 - 320 nm). The effect of this proteolytic activity on human serum results in an electrophoretic mobility towards the anode of the C3 component of complement, which thus proves to be activated. In discussing recent and former results, a hypothesis on the exacerbation of lupus erythematodes visceralis is presented: UV irradiation causes peroxydation of lipids resulting in the release of proteolytic enzymes from lysosomal membranes and activation of the complemental system. Thus the reactivity of the immune system is increased and the disease becomes exacerbated. Further the following hypothetic aspects are discussed: porphyrins cause enhanced peroxydation of lipids, increased synthesis rate of porphyrins by drugs, decrease of lipid peroxydation by antioxidants, e.g. vitamin E, in relation to possible therapeutic effects

  5. Effects of whole body UV-irradiation on oxygen delivery from the erythrocyte

    International Nuclear Information System (INIS)

    Humpeler, E.; Mairbaeurl, H.; Hoenigsmann, H.

    1982-01-01

    In 16 healthy caucasian volunteers (mean age: 22.2 years) the influence of whole body UV-irradiation on the oxygen transport properties of erythrocytes was investigated. Four hours after irradiation with UV (using the minimal erythema dose, MED) no variation of haemoglobin concentration, hematocrit, mean corpuscular haemoglobin concentration, pH or standard bicarbonate could be found, whereas inorganic plasma phosphate (Psub(i)), calcium, the intraerythrocytic 2,3-diphosphoglycerate (2,3-DPG), the activity of erythrocytic phosphofructokinase (PFK) and pyruvatekinase (PK) increased significantly. The half saturation tension of oxygen (P 50 -value) tended to increase. The increase of Psub(i) causes - via a stimulation of the glycolytic pathway - an increase in 2,3-DPG concentration and thus results in a shift of the oxygen dissociation curve. It is therefore possible to enhance tissue oxygenation by whole body UV-irradiation. (orig.)

  6. Titanium dioxide nanoparticles detoxify pirimicarb under UV irradiation at ambient intensities.

    Science.gov (United States)

    Seitz, Frank; Bundschuh, Mirco; Dabrunz, André; Bandow, Nicole; Schaumann, Gabriele E; Schulz, Ralf

    2012-03-01

    Titanium dioxide nanoparticles (nTiO₂) form reactive oxygen species (ROS) under irradiation by ultraviolet light (UV). This known photocatalytic activity may finally affect the presence and toxicity of organic environmental chemicals, which have not yet been studied at ambient UV intensity. The authors used a three-factorial design to evaluate the interaction of the carbamate insecticide pirimicarb (initial nominal concentration, 20 µg/L), ambient UV irradiation (40 W/m² for 15 min), and nTiO₂(~100 nm; 2.0 mg/L). Pirimicarb, pirimicarb × UV, and pirimicarb × nTiO₂ treatments revealed a median immobilization of Daphnia magna after 72 h ranging between 70 and 80%. This effect seemed to be caused by the initial nominal pirimicarb concentration. However, UV irradiation before an exposure of daphnids in the presence of 2.0 mg nTiO₂/L reduced pirimicarb concentrations to values below the limit of quantification, likely because of the formation of ROS. This reduction was associated with an almost complete removal of toxicity for D. magna. Furthermore, during a second experiment, 0.2 mg nTiO₂/L in combination with 15 min UV irradiation reduced pirimicarb concentrations by approximately 30%. These results indicate a detoxification and therefore remediation potential of the combined application of nTiO₂ and UV irradiation at ambient levels. This potential has not been documented to date in surface waters, where nTiO₂ concentrations in the low to medium µg/L range may occur. Copyright © 2011 SETAC.

  7. XANES Analysis of Organic Residues Produced from the UV Irradiation of Astrophysical Ice Analogs

    Science.gov (United States)

    2011-01-01

    indicate that they are rich in nitrogen- and oxygen-bearing species. These data can be compared with XANES measurements of extraterrestrial materials...reserved. Keywords: Ices; UV irradiation; XANES spectroscopy; Extraterrestrial materials 1. Introduction The origin of the organic molecules that constitute...the building blocks of life and/or their precur- sors, are formed in the interstellar medium (ISM) at the surface of cold silicate and carbonaceous

  8. A Simple and Efficient Method to Improve Mechanical Properties of Collagen Scaffolds by UV Irradiation

    Directory of Open Access Journals (Sweden)

    F. Khayyatan

    2010-12-01

    Full Text Available Collagen is the major protein component of cartilage, bone, skin and connective tissue and constitutes the major part of the extracellular matrix. Collagen type I has complex structural hierarchy, which consists of treepolypeptide α-chains wound together in a rod-like helical structure. Collagen is an important biomaterial, finding many applications in the field of tissue engineering. It has been processed into various shapes, such as, gel, film, sponge and fiber. It is commonly used as the scaffolding material for tissue engineering due to its many superior properties including low antigenicity and high growth promotion. Unfortunately, poor mechanical properties and rapid degradation rates of collagen scaffolds can cause instability and difficulty in handling. By crosslinking, the structural stability of the collagen and its rate of resorption can be adapted with respect to its demanding requirements. The strength, resorption rate, and biocompatibility of collagenous biomaterials are profoundly influenced by the method and extent of crosslinking. In thisstudy, the effect of UV irradiation on collagen scaffolds has been carried out.Collagen scaffolds were fabricated using freeze drying method with freezing temperature of -80oC, then exposed to UV irradiation. Mean pore size of the scaffolds was obtained as 98.52±14.51 μm using scanning electron microscopy. Collagen scaffolds exposed to UV Irradiation (254 nm for 15 min showed the highest tensile strain (17.37±0.98 %, modulus (1.67±0.15 MPa and maximum load (24.47±2.38 cN values. As partial loss of the native collagen structure may influence attachment, migration, and proliferation of cells on collagen scaffolds, we detected no intact α-chains after SDS-Page chromatography. We demonstrate that UV irradiation is a rapid and easily controlled means of increasing the mechanical strength of collagen scaffolds without any molecular fracture.

  9. UV irradiation and autoclave treatment for elimination of contaminating DNA from laboratory consumables.

    Science.gov (United States)

    Gefrides, Lisa A; Powell, Mark C; Donley, Michael A; Kahn, Roger

    2010-02-01

    Laboratories employ various approaches to ensure that their consumables are free of DNA contamination. They may purchase pre-treated consumables, perform quality control checks prior to casework, and use in-house profile databases for contamination detection. It is better to prevent contamination prior to DNA typing than identify it after samples are processed. To this end, laboratories may UV irradiate or autoclave consumables prior to use but treatment procedures are typically based on killing microorganisms and not on the elimination of DNA. We report a systematic study of UV and autoclave treatments on the persistence of DNA from saliva. This study was undertaken to determine the best decontamination strategy for the removal of DNA from laboratory consumables. We have identified autoclave and UV irradiation procedures that can eliminate nanogram quantities of contaminating DNA contained within cellular material. Autoclaving is more effective than UV irradiation because it can eliminate short fragments of contaminating DNA more effectively. Lengthy autoclave or UV irradiation treatments are required. Depending on bulb power, a UV crosslinker may take a minimum of 2h to achieve an effective dose for elimination of nanogram quantities of contaminating DNA (>7250mJ/cm(2)). Similarly autoclaving may also take 2h to eliminate similar quantities of contaminating DNA. For this study, we used dried saliva stains to determine the effective dose. Dried saliva stains were chosen because purified DNA as well as fresh saliva are less difficult to eradicate than dried stains and also because consumable contamination is more likely to be in the form of a collection of dry cells.

  10. Kinetic regime of aggregation of UV-irradiated glyceraldehyde-3-phosphate dehydrogenase from rabbit skeletal muscle.

    Science.gov (United States)

    Kurganov, Boris I

    2018-01-01

    The study of the kinetics of aggregation of UV-irradiated proteins has attracted considerable interest, since test systems based on aggregation of proteins denatured by UV radiation can be used for screening of the natural and artificial agents possessing chaperone-like activity (anti-aggregation activity). To provide the proper interpretation of the effects caused by the agents under study, the kinetic mechanism of the aggregation process should be established. In the present work the kinetic data on aggregation of UV-irradiated glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from rabbit skeletal muscle at 37 °C (O.I. Maloletkina et al. Biophys. Chem. 163-164 (2012) 11-20) have been analyzed. It has been shown that the stage of aggregate growth follows the first-order kinetics and the experimentally measured rate constant of the first order corresponds to heat-induced structural reorganization of UV-irradiated GAPDH containing concealed damage. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Effect of blood UV-irradiation on the development of alimentary cholesterol atherosclerosis in rabbits (preliminary data)

    International Nuclear Information System (INIS)

    Chernigovskaya, S.V.; Yanushkene, T.S.

    1986-01-01

    In-house and literature data on possible effect of autotransfusion of UV-irradiated blood (AUVIB) on the development of hypercholesterolemia in rabbits and degree of ateriosclerotic change manifestation in the aorta of the animals are discussed

  12. OMI/Aura Surface UV Irradiance 1-orbit L2 Swath 13x24 km V003

    Data.gov (United States)

    National Aeronautics and Space Administration — The Version 003 of Aura-OMI Surface UV Irradiance Product OMUVB is now available(http://disc.gsfc.nasa.gov/Aura/OMI/omuvb_v003.shtml) from the NASA Goddard Earth...

  13. Improved osteoblast response to UV-irradiated PMMA/TiO2 nanocomposites with controllable wettability.

    Science.gov (United States)

    Shayan, Mahdis; Jung, Youngsoo; Huang, Po-Shun; Moradi, Marzyeh; Plakseychuk, Anton Y; Lee, Jung-Kun; Shankar, Ravi; Chun, Youngjae

    2014-12-01

    Osteoblast response was evaluated with polymethylmethacrylate (PMMA)/titanium dioxide (TiO2) nanocomposite thin films that exhibit the controllable wettability with ultraviolet (UV) treatment. In this study, three samples of PMMA/TiO2 were fabricated with three different compositional volume ratios (i.e., 25/75, 50/50, and 75/25) followed by UV treatment for 0, 4, and 8 h. All samples showed the increased hydrophilicity after UV irradiation. The films fabricated with the greater amount of TiO2 and treated with the longer UV irradiation time increased the hydrophilicity more. The partial elimination of PMMA on the surface after UV irradiation created a durable hydrophilic surface by (1) exposing higher amount of TiO2 on the surface, (2) increasing the hydroxyl groups on the TiO2 surface, and (3) producing a mesoporous structure that helps to hold the water molecules on the surface longer. The partial elimination of PMMA on the surface was confirmed by Fourier transform infrared spectroscopy. Surface profiler and atomic force microscopy demonstrated the increased surface roughness after UV irradiation. Both scanning electron microscopy and energy-dispersive X-ray spectroscopy demonstrated that particles containing calcium and phosphate elements appeared on the 8 h UV-treated surface of PMMA/TiO2 25/75 samples after 4 days soaking in Dulbecco's Modified Eagle Medium. UV treatment showed the osteoblast adhesion improved on all the surfaces. While all UV-treated hydrophilic samples demonstrated the improvement of osteoblast cell adhesion, the PMMA/TiO2 25/75 sample after 8 h UV irradiation (n = 5, P value = 0.000) represented the best cellular response as compared to other samples. UV-treated PMMA/TiO2 nanocomposite thin films with controllable surface properties represent a high potential for the biomaterials used in both orthopedic and dental applications.

  14. Impact of UV-irradiation on electrical impedance spectroscopy of benign nevi: study protocol for a prospective, controlled, clinical study.

    Science.gov (United States)

    Fink, Christine; Schweizer, Anissa; Uhlmann, Lorenz; Haenssle, Holger A

    2017-11-08

    The clinical and histological changes of nevi after ultraviolet (UV) irradiation have been studied in detail. In contrast, the impact of UV irradiation on electrical impedance spectroscopy scores of nevi has not been investigated. However, for physicians, it is essential to know the extent to which changes in electrical impedance spectroscopy scores of nevi may be attributed to seasonal effects of UV irradiation. This is a prospective, controlled, clinical study evaluating the impact of UV irradiation on the electrical impedance spectroscopy scores of benign nevi in 50 patients undergoing phototherapy. To this end, benign nevi of patients with a medical indication for phototherapy will be measured by electrical impedance spectroscopy before, during and after UV irradiation. At the same time, non-irradiated nevi of the same patient will be measured to account for changes over time that are independent of direct UV irradiation. Ethical approval was obtained from the ethics committee of the medical faculty of the University of Heidelberg (ethics approval number S-279/2017). The design and the final results of the study will be published and made available to the public. DRKS00012456; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  15. Mutagenesis and reparation processes in the methylotrophic bacterium Pseudomonas methanolica after UV irradiation

    International Nuclear Information System (INIS)

    Naumov, G.N.; Bokhan, I.K.; Multykh, I.G.

    1986-01-01

    High resistance of cells of methylotrophic bacterium Pseudomonas methanolica to bactericidal and mutagenous effects of ultraviolet irradiation is shown as well as activity of reparation processes after UV irradiation. The presence of low photoreactivating activity in P. methanolica is shown as well. Observed recovery in innutritious medium and decrease of irradiated cells survival rates under effect of reparation inhibitors (coffeine and acriflavine) testify to activity of excision reparation and, perhaps, recombination branch of postreplicative reparation. No manifestation of inducible reparation system is discovered. It is concluded that increased resistance of P. methanolica cells to bactericidal and mutagenous effects of short-wave ultraviolet radiation is related to activity of exact reparation systems

  16. The impact of short-term UV irradiation on grains of sensitive and tolerant cereal genotypes studied by EPR.

    Science.gov (United States)

    Kurdziel, Magdalena; Filek, Maria; Łabanowska, Maria

    2017-10-24

    UV irradiation has ionisation character and leads to the generation of reactive oxygen species (ROS). The destructive character of ROS was observed among others during interaction of cereal grains with ozone and was caused by changes in structures of biomolecules leading to the formation of stable organic radicals. That effect was more evident for stress sensitive genotypes. In this study we investigated the influence of UV irradiation on cereal grains originating from genotypes with different tolerance to oxidative stress. Grains and their parts (endosperm, embryo and seed coat) of barley, wheat and oat were subjected to short-term UV irradiation. It was found that UV caused the appearance of various kinds of reactive species (O 2 -• , H 2 O 2 ) and stable radicals (semiquinone, phenoxyl and carbon-centred). Simultaneously, lipid peroxidation occurred and the organic structure of Mn(II) and Fe(III) complexes become disturbed. UV irradiation causes damage of main biochemical structures of plant tissues, the effect is more significant in sensitive genotypes. In comparison with ozone treatment, UV irradiation leads to stronger destruction of biomolecules in grains and their parts. It is caused by the high energy of UV light, facilitating easier breakage of molecular bonds in biochemical compounds. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  17. 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.

  18. Ultraviolet spectral reflectance of ceiling tiles, and implications for the safe use of upper-room ultraviolet germicidal irradiation.

    Science.gov (United States)

    Wengraitis, Stephen; Reed, Nicholas G

    2012-01-01

    Ultraviolet germicidal irradiation can be used to prevent airborne transmission of infectious diseases. A common application is to irradiate upper-room areas, by passing air from the lower room into the irradiated zone. Well-designed systems do not expose people directly; however, some UV radiation may be reflected off ceiling tiles and wall paints into the lower room. Lower room exposure should be limited to the American Conference of Governmental Industrial Hygienists threshold limit value of 6 mJ·cm(-2) of 254 nm radiation per day. To limit the lower room exposure, the reflectance of upper-room surfaces must not be high. The reflective properties of wall paints have been studied, but less is known about the UV reflectance of ceiling tiles. Using a double monochromator spectroradiometer and an integrating sphere reflectance attachment, the UV spectral reflectance of 37 ceiling tiles was measured from 200 to 400 nm. The reflectances varied from 0.020 to 0.822 in this range, and from 0.035 to 0.459 at 254 nm, the main wavelength emitted by upper room low-pressure mercury germicidal lamps. These data were then used to estimate an 8 h exposure based on several simplified workplace scenarios. The implications for workplace safety are then discussed. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

  19. Processive nicking activity of T4 endonuclease V on UV-irradiated chromatin

    International Nuclear Information System (INIS)

    Gruskin, E.A.; Lloyd, R.S.

    1986-01-01

    T4 endonuclease V initiates the excision repair of pyrimidine dimers in UV-irradiated T4 infected E. coli cells. The pyrimidine dimer specific nicking activity of T4 endonuclease V functions by a processive scanning on UV-irradiated DNA. Previously it has been demonstrated that introduction of endonuclease V into repair-deficient human cells causes a restoration of UV survival in these cells. This demonstrates that endonuclease V is competent to incise mammalian DNA at the site of pyrimidine dimers. In order to assess the ability of endonuclease V to act processively on DNA associated as chromatin, minichromosomes were prepared for use as a substrate. Form I DNA was reconstituted with H3, H4 +/- H1 histones by sequential dialysis steps from 2.0 M NaCl to 50 mM NaCl. Time course reactions were performed with minichromosomes containing 10 and 25 dimers per molecule. In each case the rate of disappearance of form I DNA which was associated as chromatin was decreased relative to that of naked form I DNA. Concurrent with that observation, the rate and extent of appearance of form III DNA was increased with the DNA in minichromosomes relative to naked DNA. This is diagnostic of an enhancement of processivity. The inclusion of H1 in the minichromosomes resulted in a slight additional increase in processivity relative to minichromosomes consisting only of H3 and H4

  20. Characterization of substances that restore impaired cell division of UV-irradiated E. coli B

    International Nuclear Information System (INIS)

    Yoshiyama, Y.; Shimoii, H.; Tamura, G.

    1981-01-01

    Substances which restore impaired cell division in UV-irradiated E. coli B were surveyed among various bacteria. The active substance was found only in several genera of Gram-negative bacteria, i.e., Escherichia, Enterobacter, Salmonella and some species of Pseudomonas. The activity in the dialyzed cell extract of E. coli B/r was observed in the presence of β-NAD and was enhanced by Mg 2+ and Mn 2+ . The active substance was very labile, but the activity was protected by 1 mM dithiothreitol in the process of purification. The activity of a fraction recovered through DEAE-cellulose column chromatography was stimulated by the presence of membrane fraction. Upon treatment with lipid-degrading enzymes and proteases, the division-stimulating activity was lost or reduced. It appears that the inactivation by lipase and phospholipase A2 was due to the formation of lysophospholipids and that a proteinous substance participated in the recovery of impaired cell division of UV-irradiated E. coli B

  1. Algae and UV irradiation: effects on ultrastructure and related metabolic functions.

    Science.gov (United States)

    Holzinger, Andreas; Lütz, Cornelius

    2006-01-01

    The effects of ultraviolet radiation in the biological relevant wavebands of UV-A (315-400 nm) and UV-B (280-315 nm) on algae have become an important issue as a man-made depletion of the protecting ozone layer has been reported. However, experimental designs to investigate this issue are manifold and the target organisms are extremely diverse. Data are included from the prokaryotic cyanobacteria, haptophytes, diatoms, brown algae to green algae (fresh water, snow algae and marine species) including different habitats from marine littoral and open ocean to freshwater ponds, lakes and snow fields. A broad overview on UV effects on algae is given, with a focus on structurally visible changes. Here we report on destruction in chloroplasts, mitochondria, and the occurrence of structures that are likely to be related to the UV stress. In addition several new data are presented from organisms that have to face naturally high UV irradiation due to their habitats. As no disturbances are reported in these organisms, they obviously have a set of protective mechanisms allowing survival in extreme habitats such as snow fields. Physiological changes as a consequence of UV irradiation are included, effects on the DNA level are summarized, and avoidance strategies are discussed. Every effort has been made to summarize the diverse observations and critically evaluate and compare the different experimental strategies to study UV effects in algae.

  2. Listeria monocytogenes behaviour in presence of non-UV-irradiated titanium dioxide nanoparticles.

    Directory of Open Access Journals (Sweden)

    Maria Grazia Ammendolia

    Full Text Available Listeria monocytogenes is the agent of listeriosis, a food-borne disease. It represents a serious problem for the food industry because of its environmental persistence mainly due to its ability to form biofilm on a variety of surfaces. Microrganisms attached on the surfaces are a potential source of contamination for environment and animals and humans. Titanium dioxide nanoparticles (TiO2 NPs are used in food industry in a variety of products and it was reported that daily exposure to these nanomaterials is very high. Anti-listerial activity of TiO2 NPs was investigated only with UV-irradiated nanomaterials, based on generation of reactive oxigen species (ROS with antibacterial effect after UV exposure. Since both Listeria monocytogenes and TiO2 NPs are veicolated with foods, this study explores the interaction between Listeria monocytogenes and non UV-irradiated TiO2 NPs, with special focus on biofilm formation and intestinal cell interaction. Scanning electron microscopy and quantitative measurements of biofilm mass indicate that NPs influence both production and structural architecture of listerial biofilm. Moreover, TiO2 NPs show to interfere with bacterial interaction to intestinal cells. Increased biofilm production due to TiO2 NPs exposure may favour bacterial survival in environment and its transmission to animal and human hosts.

  3. Sulfonation of polyester fabrics by gaseous sulfur oxide activated by UV irradiation

    International Nuclear Information System (INIS)

    Kordoghli, Bessem; Khiari, Ramzi; Mhenni, Mohamed Farouk; Sakli, Faouzi; Belgacem, Mohamed Naceur

    2012-01-01

    Highlights: ► In this paper, an original technique was present to improve the hydrophilic properties of polyester fibres. ► The modification of PET fabric was carried out using gaseous sulfur trioxide activated by UV irradiations. ► We fully characterized the modified and untreated fabrics. - Abstract: This paper describes an original technique aiming to improve the hydrophilic properties of polyester fibres. In this method, the sulfonation of the aromatic rings is carried out using gaseous sulfur trioxide activated by UV irradiations. Thus, exposing the polyester textile fabric to the UVC light (wavelength around 254 nm) under a stream of sulfur trioxide leads to the fixation of -SO 3 H groups. The amounts of the fixed sulfonate groups depended on the reaction conditions. Evidence of grafting deduced from the measurements of hygroscopic properties was carried out by contact angle measurement, moisture regain as well as by measuring the rate of retention. SEM and FT-IR analysis, DSC and DTA/TGA thermograms showed that no significant modifications have occurred in the bulk of the treated PET fabrics.

  4. Sulfonation of polyester fabrics by gaseous sulfur oxide activated by UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kordoghli, Bessem [Laboratory of Applied Chemical and Environment (UR-CAE) - University of Monastir (Tunisia); Textile Research Laboratory (LRT) - ISET Kasr Hellal, University of Monastir (Tunisia); Khiari, Ramzi, E-mail: khiari_ramzi2000@yahoo.fr [Laboratory of Applied Chemical and Environment (UR-CAE) - University of Monastir (Tunisia); LGP2 - Laboratory of Pulp and Paper Science, 461, Rue de la Papeterie - BP 65, 38402 Saint Martin d' Heres Cedex (France); Mhenni, Mohamed Farouk [Laboratory of Applied Chemical and Environment (UR-CAE) - University of Monastir (Tunisia); Sakli, Faouzi [Textile Research Laboratory (LRT) - ISET Kasr Hellal, University of Monastir (Tunisia); Belgacem, Mohamed Naceur [LGP2 - Laboratory of Pulp and Paper Science, 461, Rue de la Papeterie - BP 65, 38402 Saint Martin d' Heres Cedex (France)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer In this paper, an original technique was present to improve the hydrophilic properties of polyester fibres. Black-Right-Pointing-Pointer The modification of PET fabric was carried out using gaseous sulfur trioxide activated by UV irradiations. Black-Right-Pointing-Pointer We fully characterized the modified and untreated fabrics. - Abstract: This paper describes an original technique aiming to improve the hydrophilic properties of polyester fibres. In this method, the sulfonation of the aromatic rings is carried out using gaseous sulfur trioxide activated by UV irradiations. Thus, exposing the polyester textile fabric to the UVC light (wavelength around 254 nm) under a stream of sulfur trioxide leads to the fixation of -SO{sub 3}H groups. The amounts of the fixed sulfonate groups depended on the reaction conditions. Evidence of grafting deduced from the measurements of hygroscopic properties was carried out by contact angle measurement, moisture regain as well as by measuring the rate of retention. SEM and FT-IR analysis, DSC and DTA/TGA thermograms showed that no significant modifications have occurred in the bulk of the treated PET fabrics.

  5. Effect of visible and UV irradiation on the aggregation stability of CdTe quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Tsipotan, Aleksei S.; Gerasimova, Marina A.; Aleksandrovsky, Aleksandr S., E-mail: aleksandrovsky@kirensky.ru; Zharkov, Sergey M.; Slabko, Vitaliy V. [Siberian Federal University (Russian Federation)

    2016-11-15

    The possibility of controlling the aggregation stability of CdTe quantum dots (QDs) stabilized by thioglycolic acid (TGA) is important for implementation of quasi-resonant laser-induced self-assembly. This study examines the influence of irradiation by the UV as well as by the visible light on the photostimulated aggregation of QDs. Different photochemical mechanisms are identified, depending on whether light wavelength falls into an interband transition or the first exciton transition. Irradiation by visible light does not lead to changes in the absorption spectra but decreases luminescence intensity through the detachment of TGA and the formation of dangling bonds, leading to the creation of radiativeless relaxation centers. UV irradiation (in the 300–370 nm range), at an intensity of 0.4 W/cm{sup 2}, initially (during the first 75 min) leads to the degradation of the stabilizer and QDs’ surface. After 75 min of combined UV and visible light irradiation, a gradual increase in spontaneous aggregation takes place, testifying excessive decrease in stabilizing potential barrier height. Hence, the laser-induced self-assembly of CdTe QDs is recommended to be performed over a time period of between 80 and 100 min after the beginning of low-intensity UV irradiation under conditions equivalent to those applied in this study.

  6. The alteration of Paramecium candatum germinal nucleus morphology after UV irradiation

    International Nuclear Information System (INIS)

    Fokin, S.I.

    1982-01-01

    A study was made on morphologic changes of micronucleus (Mi) after whole-body ultraviolet (UV) irradiation of paramecia as well as after local irradiation of this nucleus or the area of macronucleus (Ma). The whole-body irradiation of its Ma part leads to generative nucleus growth in sizes and chromatin structure change, which is expressed in occurence of large chromatin bodies. Aftereffects of local action on Mi for viaable descendants are expressed in nucleus size transformation (usually in reduction), gaining ''comet-shaped'' form and probably in reduction of dna amount. Irradiation of Ma and total effect on cell cause Mi changes of reversible character. All morphologic changes of Mi after local ultraviolet irradiation are conserved in descendants and are not photoreactivated. Possible reasons for this phenomenon are discussed. The results obtained make it possible to speak about different mechanisms of action on Mi in the case of local and whole-body UV irradiation of cell. The effect of irradiated Ma on generative nucleus, but not direct damage of this nucleus is the reason for Mi morphologic reconstruction after whole-body action on paramecium

  7. Effect of UV irradiation on aflatoxin reduction: a cytotoxicity evaluation study using human hepatoma cell line.

    Science.gov (United States)

    Patras, Ankit; Julakanti, Sharath; Yannam, Sudheer; Bansode, Rishipal R; Burns, Mallory; Vergne, Matthew J

    2017-11-01

    In this proof-of-concept study, the efficacy of a medium-pressure UV (MPUV) lamp source to reduce the concentrations of aflatoxin B 1 , aflatoxin B 2 , and aflatoxin G 1 (AFB 1, AFB 2 , and AFG 1 ) in pure water is investigated. Irradiation experiments were conducted using a collimated beam system operating between 200 to 360 nm. The optical absorbance of the solution and the irradiance of the lamp are considered in calculating the average fluence rate. Based on these factors, the UV dose was quantified as a product of average fluence rate and treatment time. Known concentrations of aflatoxins were spiked in water and irradiated at UV doses ranging from 0, 1.22, 2.44, 3.66, and 4.88 J cm -2 . The concentration of aflatoxins was determined by HPLC with fluorescence detection. LC-MS/MS product ion scans were used to identify and semi-quantify degraded products of AFB 1 , AFB 2 , and AFG 1 . It was observed that UV irradiation significantly reduced aflatoxins in pure water (p UV light may have caused photolysis of AFB 1 , AFB 2 , and AFG 1 molecules. In cell culture studies, our results demonstrated that the increase of UV dosage decreased the aflatoxin-induced cytotoxicity in HepG 2 cells. Therefore, our research finding suggests that UV irradiation can be used as an effective technique for the reduction of aflatoxins.

  8. UV irradiation impairs in vivo encapsidation of bacteriophage T4 DNA

    International Nuclear Information System (INIS)

    Zachary, A.; Black, L.W.

    1984-01-01

    T4 DNA structural requirements for encapsidation in vivo were investigated, using thin-section electron microscopy to quantitate the kinetics and yields of head intermediates after synchronous DNA packaging into accumulated processed proheads. UV irradiation (254 nm) of T4-infected bacteria just before initiation of encapsidation resulted in a reduction in the rate of DNA packaged measured by electron microscopy and in the yield of viable phage progeny. In UV-irradiated infections with excision-deficient mutants (denV-), the extent of packaging decline was proportional to the UV dose and phage yields were lower than expected based on the packaging levels observed by microscopy. Rescue analysis of progeny from such infections revealed elevated levels of nonviable virions. Pyrimidine dimers were encapsidated in denV- infections, but in excision-competent infections (denV+) dimers were not packaged. A UV-independent, 15 to 20% packaging arrest was also observed when denV endonuclease was inactive during encapsidation, indicating a denV requirement to achieve normal T4 packaging levels. Pyrimidine dimers apparently represent or induce transient blockage of DNA encapsidation or both, causing a decline in the rate. This is in contrast to other DNA structural blocks to packaging induced by mutations in T4 genes 30 and 49, which appear to arrest the process

  9. Listeria monocytogenes behaviour in presence of non-UV-irradiated titanium dioxide nanoparticles.

    Science.gov (United States)

    Ammendolia, Maria Grazia; Iosi, Francesca; De Berardis, Barbara; Guccione, Giuliana; Superti, Fabiana; Conte, Maria Pia; Longhi, Catia

    2014-01-01

    Listeria monocytogenes is the agent of listeriosis, a food-borne disease. It represents a serious problem for the food industry because of its environmental persistence mainly due to its ability to form biofilm on a variety of surfaces. Microrganisms attached on the surfaces are a potential source of contamination for environment and animals and humans. Titanium dioxide nanoparticles (TiO2 NPs) are used in food industry in a variety of products and it was reported that daily exposure to these nanomaterials is very high. Anti-listerial activity of TiO2 NPs was investigated only with UV-irradiated nanomaterials, based on generation of reactive oxigen species (ROS) with antibacterial effect after UV exposure. Since both Listeria monocytogenes and TiO2 NPs are veicolated with foods, this study explores the interaction between Listeria monocytogenes and non UV-irradiated TiO2 NPs, with special focus on biofilm formation and intestinal cell interaction. Scanning electron microscopy and quantitative measurements of biofilm mass indicate that NPs influence both production and structural architecture of listerial biofilm. Moreover, TiO2 NPs show to interfere with bacterial interaction to intestinal cells. Increased biofilm production due to TiO2 NPs exposure may favour bacterial survival in environment and its transmission to animal and human hosts.

  10. Sensitivity of Vibrio cholerae cells to lethal and mutagenic effect of UV-irradiation mediated by plasmids

    International Nuclear Information System (INIS)

    Tiganova, I.G.; Evdokimova, N.M.; Aleshkin, G.I.

    1988-01-01

    The effect of UV-irradiation on Vibrio cholerae cells and its changes mediated by the plasmid R245 have been studied. Vibrio cholerae strains 569B and RV31 have been shown to be considerably more sensitive to lethal effect of UV-irradiation as compared with Escherichia coli and Salmonella typhimurium cells. Highly toxigenic strain 569B and practically atoxigenic strain RV31 have the same UV-sensitivity. Lethla effect of UV-irradiation on Vibrio cholerae cells is incresed when the irradiated cells are plated on enriched media. UV-induction of mutations was not registered in plasmidless strains of Vibrio cholerae. Plasmid R245 increase UV-resistance of vibrio cells and makes them UV-mutable

  11. Postreplicational formation and repair of DNA double-strand breaks in UV-irradiated Escherichia coli uvrB cells

    International Nuclear Information System (INIS)

    Wang, Tzuchien V.; Smith, K.C.

    1986-01-01

    The number of DNA double-strand breaks formed in UV-irradiated uvrB recF recB cells correlates with the number of unrepaired DNA daughter-strand gaps, and is dependent on DNA synthesis after UV-irradiation. These results are consistent with the model that the DNA double-strand breaks that are produced in UV-irradiated excision-deficient cells occur as the result of breaks in the parental DNA opposite unrepaired DNA daughter-strand gaps. By employing a temperature-sensitive recA200 mutation, we have devised an improved assay for studying the formation and repair of these DNA double-strand breaks. Possible mechanisms for the postreplication repair of DNA double-strand breaks are discussed. (Auth.)

  12. GCN5 protects vertebrate cells against UV-irradiation via controlling gene expression of DNA polymerase η.

    Science.gov (United States)

    Kikuchi, Hidehiko; Kuribayashi, Futoshi; Imajoh-Ohmi, Shinobu; Nishitoh, Hideki; Takami, Yasunari; Nakayama, Tatsuo

    2012-11-16

    By UV-irradiation, cells are subjected to DNA damage followed by mutation, cell death and/or carcinogenesis. DNA repair systems such as nucleotide excision repair (NER) and translesion DNA synthesis (TLS) protect cells against UV-irradiation. To understand the role of histone acetyltransferase GCN5 in regulation of DNA repair, we studied the sensitivity of GCN5-deficient DT40, GCN5(-/-), to various DNA-damaging agents including UV-irradiation, and effects of GCN5-deficiency on the expression of NER- and TLS-related genes. After UV-irradiation, cell death and DNA fragmentation of GCN5(-/-) were appreciably accelerated as compared with those of DT40. Interestingly, GCN5(-/-) showed a remarkable sensitivity to only UV-irradiation but not to other DNA-damaging agents tested. Semiquantitative RT-PCR showed that transcription of DNA polymerase η (POLH) gene whose deficiency is responsible for a variant form of xeroderma pigmentosum was drastically down-regulated in GCN5(-/-) (to ∼25%). In addition, ectopic expression of human POLH in GCN5(-/-) dramatically reversed the sensitivity to UV-irradiation of GCN5(-/-) to almost the same level of wild type DT40. Moreover, chromatin immunoprecipitation assay revealed that GCN5 binds to the chicken POLH gene 5'-flanking region that contains a typical CpG island and acetylates Lys-9 of histone H3, but not Lys-14 in vivo. These data suggest that GCN5 takes part in transcription regulation of POLH gene through alterations in the chromatin structure by direct interaction with its 5'-flanking region, and protects vertebrate cells against UV-induced DNA damage via controlling POLH gene expression.

  13. GCN5 Protects Vertebrate Cells against UV-irradiation via Controlling Gene Expression of DNA Polymerase η*

    Science.gov (United States)

    Kikuchi, Hidehiko; Kuribayashi, Futoshi; Imajoh-Ohmi, Shinobu; Nishitoh, Hideki; Takami, Yasunari; Nakayama, Tatsuo

    2012-01-01

    By UV-irradiation, cells are subjected to DNA damage followed by mutation, cell death and/or carcinogenesis. DNA repair systems such as nucleotide excision repair (NER) and translesion DNA synthesis (TLS) protect cells against UV-irradiation. To understand the role of histone acetyltransferase GCN5 in regulation of DNA repair, we studied the sensitivity of GCN5-deficient DT40, GCN5−/−, to various DNA-damaging agents including UV-irradiation, and effects of GCN5-deficiency on the expression of NER- and TLS-related genes. After UV-irradiation, cell death and DNA fragmentation of GCN5−/− were appreciably accelerated as compared with those of DT40. Interestingly, GCN5−/− showed a remarkable sensitivity to only UV-irradiation but not to other DNA-damaging agents tested. Semiquantitative RT-PCR showed that transcription of DNA polymerase η (POLH) gene whose deficiency is responsible for a variant form of xeroderma pigmentosum was drastically down-regulated in GCN5−/− (to ∼25%). In addition, ectopic expression of human POLH in GCN5−/− dramatically reversed the sensitivity to UV-irradiation of GCN5−/− to almost the same level of wild type DT40. Moreover, chromatin immunoprecipitation assay revealed that GCN5 binds to the chicken POLH gene 5′-flanking region that contains a typical CpG island and acetylates Lys-9 of histone H3, but not Lys-14 in vivo. These data suggest that GCN5 takes part in transcription regulation of POLH gene through alterations in the chromatin structure by direct interaction with its 5′-flanking region, and protects vertebrate cells against UV-induced DNA damage via controlling POLH gene expression. PMID:23033487

  14. UV-Irradiated Photocatalytic Degradation of Nitrobenzene by Titania Binding on Quartz Tube

    Directory of Open Access Journals (Sweden)

    Thou-Jen Whang

    2012-01-01

    Full Text Available A new method for UV-irradiated degradation of nitrobenzene by titania photocatalysts was proposed, titania nanoparticles were coated on a quartz tube through the introduction of tetraethyl orthosilicate into the matrix. The dependence of nitrobenzene photodegradation on pH, temperature, concentration, and air feeding was discussed, and the physical properties such as the activation energy, entropy, enthalpy, adsorption constant, and rate constant were acquired by conducting the reactions in a variety of experimental conditions. The optimum efficiency of the photodegradation with the nitrobenzene residue as low as 8.8% was achieved according to the experimental conditions indicated. The photodegradation pathways were also investigated through HPLC, GC/MS, ion chromatography (IC, and chemical oxygen demand (COD analyses.

  15. Nucleobases and Other Prebiotic Species from the UV Irradiation of Pyrimidine in Astrophysical Ices

    Science.gov (United States)

    Sandford, Scott; Materese, Christopher; Nuevo, Michel

    2012-01-01

    Nucleobases are aromatic N-heterocycles that constitute the informational subunits of DNA and RNA and are divided into two families: pyrimidine bases (uracil, cytosine, and thymine) and purine bases (adenine and guanine). Nucleobases have been detected in meteorites and their extraterrestrial origin confirmed by isotope measurement. Although no N-heterocycles have been individually identified in the ISM, the 6.2-micron interstellar emission feature seen towards many astronomical objects suggests a population of such molecules is likely present. We report on a study of the formation of pyrimidine-based molecules, including nucleobases and other species of prebiotic interest, from the ultraviolet (UV) irradiation of pyrimidine in low temperature ices containing H2O, NH3, C3OH, and CH4, to simulate the astrophysical conditions under which prebiotic species may be formed in the Solar System.

  16. Reduction of haloforms by UV-irradiation and simultaneous addition of hydrogenperoxide in waterworks

    Energy Technology Data Exchange (ETDEWEB)

    Stachel, B.; Cetinkaya, M.; von Dueszeln, J.; Lahl, U.; Thiemann, W.; Gabel, B.; Kozicki, R.; Podbielski, A.

    1982-04-01

    One method of water treatment which is still under discussion today is UV/H/sub 2/O/sub 2/ desinfection and oxidation. This paper is a study of the reduction of ..gamma..-hexachlorocyclohexane (..gamma..-BHC), hexachlorobenzene (HCB), heptachlor, aldrin polychlorinated biphenyl (2-PCB) and two dichlorobenzenes in water by UV-irradiation and simultaneous H/sub 2/O/sub 2/ addition. The reduction of these compounds under various H/sub 2/O/sub 2/ concentrations and water flux rates were measured. There were obtained reductions between 0 and 89% of the organo-chlorine compounds which were added. The method's reliability was examined by error analysis. Problems in the use of UV/H/sub 2/O/sub 2/ and capabilities of the method for the purpose of water treatment are discussed.

  17. Effect of UV-irradiation on DNA-membrane complex of Bacillus subtilis

    International Nuclear Information System (INIS)

    Chefranova, O.A.; Gaziev, A.I.

    1979-01-01

    The UV radiation effect on DNA membrane complex of Bacillus subtilis has been studied. Increase of DNA content in the DNA membrane complex in two strains of 168 and recA - and its decrease in the polA - strain are shown. The above effect in the first two stamms is suppressed with caffeine and correlates with the change in protein content in the DNA membrane complex, determined by a radioactive label, but not lipids in other words, fixation of DNA and membrane goes through proteins. Capability of DNA content increase in the DNA membrane complex after UV irradiation and subsequent bacteria incubation in a total medium correlates with the relative sensitivity of stamm UV sensitivity. It is suggested, that the reparation synthesis goes in cells on the membrane and that binding of DNA and the membrane is necessary for the normal DNA reparation process

  18. Inactivation of bacteria found in solid particulate foods by using a continuous UV irradiation system

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchido, Tetsuaki; Hayashi, Masashi; Matsumura, Yoshinobu [Kansai Univ., Suita, Osaka (Japan). Faculty of Engineering; Ohya, Seiji

    2001-05-01

    We examined the effectiveness of a continuous tube-flow type UV irradiation system developed for cold pasteurization of solid particulate foods in flowing air. Among the six kinds of solid particulate foods tested, black pepper, red pepper, and oolong tea leaves could not be sterilized, since these were contaminated with bacterial spores which accounted for almost all counts of detectable bacteria. An apparently marked inactivation effect was obtained with green laver contaminated with relatively high counts of nonsporing bacteria. The effect of the irradiation system on green laver depended upon the flow rate of air supply and the irradiation time within the first 4 s. This system is not effective for killing bacterial spores but can be applied to kill vegetative cells. (author)

  19. Comparison of the efficacy of gamma and UV irradiation in sanitization of fresh carrot juice

    Science.gov (United States)

    Jo, Cheorun; Lee, Kyung Haeng

    2012-08-01

    As there is no pasteurization procedure for the manufacture of fresh vegetable juice, both industry and consumers have sought a method for improving the storage stability and shelf-life of this category of products. In this study, the effects of commercially available, non-thermal pasteurization processes, such as gamma and UV irradiation, were compared for their efficacy in sanitizing fresh carrot juice (FCJ). FCJ was manufactured, packaged, and gamma irradiated with doses of 0, 1, 3, and 5 kGy. The manufactured FCJ was also passed through 4 UV light lamps at doses of 3.67, 4.69, and 6.50 kGy. The total aerobic bacterial count of the FCJ approached the legal limit (105 CFU/mL) after manufacturing. Both treatments were effective in reducing the number of total aerobic bacteria, and the reduced number was maintained during storage for 7 days. Gamma irradiation was more effective in suppressing microbial growth during storage. When the doses for UV treatment and gamma irradiation were higher, the inactivation effects were higher. The reduction of ascorbic acid content was greater upon gamma irradiation than UV treatment. No difference was found in the contents of flavonoids and polyphenols in FCJ after either treatment. After 3 days of refrigerated storage, the sensory scores of gamma- or UV-irradiated FCJ were superior to those of the control. The results indicate that both non-thermal treatments were effective in improving storage stability and extending shelf-life, but gamma irradiation was slightly better in suppressing microbial growth after treatment.

  20. Repair and mutagenesis of herpes simplex virus in UV-irradiated monkey cells

    International Nuclear Information System (INIS)

    Lytle, C.D.; Goddard, J.G.; Lin, C.H.

    1980-01-01

    Mutagenic repair in mammalian cells was investigated by determining the mutagenesis of UV-irradiated or unirradiated herpes simplex virus in UV-irradiated CV-1 monkey kidney cells. These results were compared with the results for UV-enhanced virus reactivation (UVER) in the same experimental situation. High and low multiplicities of infection were used to determine the effects of multiplicity reactivation (MR). UVER and MR were readily demonstrable and were approximately equal in amount in an infectious center assay. For this study, a forward-mutation assay was developed to detect virus mutants resistant to iododeoxycytidine (ICdR), probably an indication of the mutant virus being defective at its thymidine kinase locus. ICdR-resistant mutants did not have a growth advantage over wild-type virus in irradiated or unirradiated cells. Thus, higher fractions of mutant virus indicated greater mutagenesis during virus repair and/or replication. The data showed that: (1) unirradiated virus was mutated in unirradiated cells, providing a background level of mutagenesis; (2) unirradiated virus was mutated about 40% more in irradiated cells, indicating that virus replication (DNA synthesis) became more mutagenic as a result of cell irradiation; (3) irradiated virus was mutated much more (about 6-fold) than unirradiated virus, even in unirradiated cells; (4) cell irradiation did not change the mutagenesis of irradiated virus except at high multiplicity of infection. High multiplicity of infection did not demonstrate UVER or MR alone to be either error-free or error-prone. When the two processes were present simultaneously, they were mutagenic. (orig.)

  1. Metabolic changes in the anterior segment of the eye induced by UV irradiation and measured ny NMR spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Midelfart, A.; Risa, O.; Sather, O.; Tessem, MB.; Fris, M.; Soderberg, P. G.; Čejková, Jitka

    s. 103 ISSN 0030-3747. [EVER 2004(European Association for Vision and Eye Research). 24.09.2004-27.09.2004, Vilamoura] R&D Projects: GA ČR GA304/03/0419 Keywords : UV irradiation * spectroscopy * cornea Subject RIV: FF - HEENT, Dentistry

  2. Activation of Peroxisome Proliferator-Activated Receptor Alpha Improves Aged and UV-Irradiated Skin by Catalase Induction.

    Science.gov (United States)

    Shin, Mi Hee; Lee, Se-Rah; Kim, Min-Kyoung; Shin, Chang-Yup; Lee, Dong Hun; Chung, Jin Ho

    2016-01-01

    Peroxisome proliferator-activated receptor alpha (PPARα) is a nuclear hormone receptor involved in the transcriptional regulation of lipid metabolism, fatty acid oxidation, and glucose homeostasis. Its activation stimulates antioxidant enzymes such as catalase, whose expression is decreased in aged human skin. Here we investigated the expression of PPARα in aged and ultraviolet (UV)-irradiated skin, and whether PPARα activation can modulate expressions of matrix metalloproteinase (MMP)-1 and procollagen through catalase regulation. We found that PPARα mRNA level was significantly decreased in intrinsically aged and photoaged human skin as well as in UV-irradiated skin. A PPARα activator, Wy14643, inhibited UV-induced increase of MMP-1 and decrease of procollagen expression and caused marked increase in catalase expression. Furthermore, production of reactive oxygen species (ROS) was suppressed by Wy14643 in UV-irradiated and aged dermal fibroblasts, suggesting that the PPARα activation-induced upregulation of catalase leads to scavenging of ROS produced due to UV irradiation or aging. PPARα knockdown decreased catalase expression and abolished the beneficial effects of Wy14643. Topical application of Wy14643 on hairless mice restored catalase activity and prevented MMP-13 and inflammatory responses in skin. Our findings indicate that PPARα activation triggers catalase expression and ROS scavenging, thereby protecting skin from UV-induced damage and intrinsic aging.

  3. EPR and luminescence of u.v. irradiated PbCl2 and PbBr2 crystals

    NARCIS (Netherlands)

    Gruijter, W.C. de; Kerssen, J.

    Results are presented of EPR-measurements on PbCl2 and PbBr2 single crystals at low temperatures. Pb+, Pb+-pairs and colloidal lead particles are formed during u.v. irradiation. The concentration of the Pb+-pairs increases after the irradiation is stopped. The red luminescence of both lead halides

  4. Effect of UV irradiation on free radicals in synthetic melanin and melanin biopolymer from Sepia officinalis – EPR examination

    Directory of Open Access Journals (Sweden)

    Zdybel Magdalena

    2015-07-01

    Full Text Available Free radicals in synthetic melanin and melanin from Sepia officinalis were studied by electron paramagnetic resonance (EPR spectroscopy. The effect of time of ultraviolet (UV irradiation on free radicals in these melanins was tested. The samples were exposed to UV during 15, 30, and 60 minutes. EPR spectra were measured with microwaves from an X-band (9.3 GHz in the range of microwave power of 2.2–70 mW. The performed EPR examinations indicate that high concentrations (~1021–1022 spin/g of o-semiquinone free radicals with g factors of 2.0039–2.0045 exist in all the tested samples. For nonirradiated samples, free radical concentration was higher in natural melanin than in synthetic melanin. UV irradiation caused the increase of free radical concentrations in synthetic melanin samples and this effect depends on the time of irradiation. The largest free radical formation in the both melanins was obtained for 60 min of UV irradiation. Free radical concentrations after the UV irradiation of melanins during 30 min were lower than during irradiation by 15 min, and probably this effect was the result of recombination of the radiatively formed free radicals. EPR lines of the tested samples broadened with increasing microwave power, so these lines were homogeneously broadened. The two types of melanins differed in the time of spin-lattice relaxation processes. Slower spin-lattice relaxation processes exist in melanin from Sepia officinalis than in synthetic melanin. UV irradiation did not change the time of spin-lattice relaxation processes in the tested melanins. The performed studies confirmed the usefulness of EPR spectroscopy in cosmetology and medicine.

  5. UV irradiation analysis of complementation between, and replication of, RNA-negative temperature-sensitivie mutants of Newcastle disease virus

    International Nuclear Information System (INIS)

    Peeples, M.E.; Bratt, M.A.

    1982-01-01

    Random uv irradiation-induced lesions destroy the infectivity of Newcastle disease virus (NDV) by blocking downstream transcription from the single viral promoter. The nucleocapsid-associated polypeptides most likely to be involved in RNA synthesis are located at the extreme ends of the genome: NP and P are promoter proximal genes, and L is the most distal gene. We attempted to order the two temperature-sensitive (ts) RNA-negative (RNA-) mutant groups of NDV by determining the uv target sizes for the complementing abilities of mutants A1 and E1. After uv irradiation, E1 was unable to complement A1, a result compatible with the A mutation lying in the L gene. In contrast, after uv irradiation A1 was able to complement E1 for both virus production and viral protein synthesis, with a target size most consistent with the E mutation lying in the P gene. UV-irradiated virus was unable to replicate as indicated by its absence in the yields of multiply infected cells, either as infectious virus or as particles with complementing activity. After irradiation, ts mutant B1ΔP, with a non-ts mutation affecting the electrophoretic mobility of the P protein, complemented E1 in a manner similar to A1, but it did not amplify the expression of ΔP in infected cells. This too is consistent with irradiated virus being unable to replicate despite the presence of the components needed for replication of E1. At high uv doses, A1 was able to complement E1 in a different, uv-resistant manner, probably by direct donation of input polypeptides. Multiplicity reactivation has previously been observed at high-multiplicity infection by uv-irradiated paramyxoviruses. In this case, virions which are noninfectious because they lack a protein component may be activated by a protein from irradiated virions

  6. Replication of UV-irradiated DNA in human cell extracts: Evidence for mutagenic bypass of pyrimidine dimers

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, D.C.; Kunkel, T.A. (National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States))

    1993-08-15

    The authors have examined the efficiency and fidelity of simian virus 40-origin-dependent replication of UV-irradiated double-stranded DNA in extracts of human cells. Using as a mutational target the [alpha]-complementation domain of the Escherichia coli lacZ gene in bacteriophage M13mp2DNA, replication of undamaged DNA in HeLa cell extracts was highly accurate, whereas replication of DNA irradiated with UV light (280-320 nm) was both less efficient and less accurate. Replication was inhibited by irradiation in a dose-dependent manner. Nonetheless, covalently closed, monomer-length circular products were generated that were resistant to digestion by Dpn I, showing that they resulted from semiconservative replication. These products were incised by T4 endonuclease V, whereas the undamaged replication products were not, suggesting that pyrimidine dimers were bypassed during replication. When replicated, UV-irradiated DNA was used to transfect an E. coli [alpha]-complementation host strain to score mutant M13mp2 plaques, the mutant plaque frequency was substantially higher than that obtained with either unirradiated, replicated DNA, or unreplicated, UV-irradiated DNA. Both the increased mutagenicity and the inhibition of replication associated with UV irradiation were reversed by treatment of the irradiated DNA with photolyase before replication. Sequence analysis of mutants resulting from replication of UV-irradiated DNA demonstrated that most mutants contained C [yields] T transition errors at dipyrimidine sites. A few mutants contained 1-nt frameshift errors or tandem double CC [yields] TT substitutions. The data are consistent with the interpretation that pyrimidine dimers are bypassed during replication by the multiprotein replication apparatus in human cell extracts and that this bypass is mutagenic primarily via misincorporation of dAMP opposite a cytosine (or uracil) in the dimer. 56 refs., 2 figs., 3 tabs.

  7. Effects of UV-irradiation on in vitro apatite-forming ability of TiO{sub 2} layers

    Energy Technology Data Exchange (ETDEWEB)

    Uetsuki, Keita, E-mail: dns20353@s.okayama-u.ac.jp [Graduate School of Natural Science and Technology, Okayama University, Tsushima, Kita-ku, Okayama-shi 700-8530 (Japan); Nakashima Medical Co., Ltd., Joto-Kitagata, Higashi-ku, Okayama-shi 709-0625 (Japan); Kaneda, Haruki [Faculty of Engineering, Okayama University, Tsushima, Kita-ku, Okayama-shi 700-8530 (Japan); Shirosaki, Yuki [Graduate School of Natural Science and Technology, Okayama University, Tsushima, Kita-ku, Okayama-shi 700-8530 (Japan); Hayakawa, Satoshi [Graduate School of Natural Science and Technology, Okayama University, Tsushima, Kita-ku, Okayama-shi 700-8530 (Japan); Research Center for Biomedical Engineering, Okayama University, Tsushima, Kita-ku, Okayama-shi 700-8530 (Japan); Osaka, Akiyoshi, E-mail: a-osaka@cc.okayama-u.ac.jp [Graduate School of Natural Science and Technology, Okayama University, Tsushima, Kita-ku, Okayama-shi 700-8530 (Japan); Research Center for Biomedical Engineering, Okayama University, Tsushima, Kita-ku, Okayama-shi 700-8530 (Japan)

    2010-10-15

    Titanium and its alloys are employed as artificial joints, bone plates, wires, screws and bone prostheses in orthopedic and dental fields, because of their high corrosion resistance, good mechanical properties, and biocompatibility. Since they cannot directly bond to living bone-tissue through stable chemical interactions, a few surface modification techniques have been proposed for giving materials apatite-forming ability that secures bone-tissue bonding, such as chemical treatment with H{sub 2}O{sub 2} or NaOH, electrochemical oxidation, electrophoretic apatite particle deposition, and UV-irradiation of surface titanium oxide layer. This study examined how the combination of H{sub 2}O{sub 2} chemical treatment and UV-irradiation affected in vitro apatite-formation on TiO{sub 2} (anatase phase) layers as UV was irradiated under a few different conditions. TiO{sub 2} layer was prepared by the chemical treatment with H{sub 2}O{sub 2} solution and subsequent heat-treatment (CHT). CHT samples were irradiated with UV-light for 1 h in air or in ultra-pure water. They were then soaked in Kokubo's simulated body fluid (SBF; pH 7.4) at 36.5 deg. C for 1 day. Their surface structure and morphology were examined by using a thin film X-ray diffractometer (TF-XRD), and a scanning electron microscope (SEM). The UV-irradiation of CHT in air reduced the number of active sites for apatite nucleation. On the contrary, however, the UV-irradiation in water increased them. These opposite results indicate that environmental factors of the UV-irradiation are important for controlling the in vitro apatite-forming ability of anatase layer.

  8. Local gene expression changes after UV-irradiation of human skin.

    Directory of Open Access Journals (Sweden)

    Benjamin Weinkauf

    Full Text Available UV-irradiation is a well-known translational pain model inducing local inflammation and primary hyperalgesia. The mediators and receptor proteins specifically contributing to mechanical or heat hyperalgesia are still unclear. Therefore, we irradiated buttock skin of humans (n = 16 with 5-fold MED of UV-C and assessed the time course of hyperalgesia and axon reflex erythema. In parallel, we took skin biopsies at 3, 6 and 24 h after UVC irradiation and assessed gene expression levels (RT-PCR of neurotrophins (e.g. NGF, BDNF, GDNF, ion channels (e.g. NaV1.7, TRPV1, inflammatory mediators (e.g. CCL-2, CCL-3 and enzymes (e.g. PGES, COX2. Hyperalgesia to mechanical impact (12 m/s and heat (48 °C stimuli was significant at 6 h (p<0.05 and p<0.01 and 24 h (p<0.005 and p<0.01 after irradiation. Axon reflex erythema upon mechanical and thermal stimuli was significantly increased 3 h after irradiation and particularly strong at 6 h. A significant modulation of 9 genes was found post UV-C irradiation, including NGF (3, 6, 24 h, TrkA (6, 24 h, artemin, bradykinin-1 receptor, COX-2, CCL-2 and CCL-3 (3 and 6 h each. A significant down-regulation was observed for TRPV1 and iNOS (6, 24 h. Individual one-to-one correlation analysis of hyperalgesia and gene expression revealed that changes of Nav1.7 (SCN9A mRNA levels at 6 and 24 h correlated to the intensity of mechanical hyperalgesia recorded at 24 h post UV-irradiation (Pearson r: 0.57, p<0.04 and r: 0.82, p<0.001. Expression of COX-2 and mPGES at 6 h correlated to the intensity of heat-induced erythema 24 h post UV (r: 0.57, p<0.05 for COX-2 and r: 0.83, p<0.001 for PGES. The individual correlation analyses of functional readouts (erythema and pain response with local expression changes provided evidence for a potential role of Nav1.7 in mechanical hyperalgesia.

  9. Coffee grounds as filler for pectin: Green composites with competitive performances dependent on the UV irradiation.

    Science.gov (United States)

    Cataldo, Vincenzo Alessandro; Cavallaro, Giuseppe; Lazzara, Giuseppe; Milioto, Stefana; Parisi, Filippo

    2017-08-15

    Novel composite bioplastics were successfully prepared by filling pectin matrix with treated coffee grounds. The amount of coffee dispersed into the pectin was changed within a wide filler range. The morphology of the pectin/coffee hybrid films was studied by microscopic techniques in order to investigate their mesoscopic structure as well as the sizes distribution of the particles dispersed into the matrix. The micrographs showed that the coffee grounds are uniformly dispersed within the polymeric matrix. The morphological characteristics of the biocomposite films were correlated to their properties, such as wettability, water uptake, thermal behavior and mechanical performances. Dynamic mechanical test were conducted as a function of the humidity conditions. As a general result, a worsening of the mechanical performances was induced by the addition of the coffee grounds into the pectin. An additional UV curing treatment was conducted on the pectin/coffee films with the aim to improve their tensile and viscoelastic features. The cured films showed promising and tunable properties that are dependent on both the filler content and the UV irradiation. In particular, the presence of single coffee particles into the pectin matrix renders the UV curing treatment effective in the enhancement of the elasticity as well as the traction resistance, whereas the cured composite films containing coffee clusters showed only more elastic characteristics. With this study, we fabricated pectin/coffee bioplastics with controlled behavior appealing for specific application within the food packaging. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Decolorization of Methylene Blue with TiO2 Sol via UV Irradiation Photocatalytic Degradation

    Directory of Open Access Journals (Sweden)

    Jun Yao

    2010-01-01

    Full Text Available TiO2 sol was prepared for the degradation of methylene blue (MB solution under ultraviolet (UV irradiation. The absorption spectra of MB indicated that the maximum wavelength, 663 nm, almost kept the same. The performance of 92.3% for color removal was reached after 160 min. The particle size of TiO2 sol was about 22.5 nm. X-ray diffraction showed that TiO2 consisted of a single anatase phase. The small size and anatase phase probably resulted in high photocatalytic activity of TiO2 sol. The degradation ratio decreased as the initial concentration of MB increased. The photodegradation efficiency decreased in the order of pH 2>pH 9>pH 7. Regarding catalyst load, the degradation increased with the mass of catalyst up to an amount of 1.5 g⋅L−1 then decreased as the mass continued to increase. The addition of H2O2 to TiO2 sol resulted in an increase on the degradation ratio.

  11. Effect of UV irradiation on the apoptosis and necrosis of Jurkat cells using UV LEDs

    Science.gov (United States)

    Inada, Shunko A.; Amano, Hiroshi; Akasaki, Isamu; Morita, Akimichi; Kobayashi, Keiko

    2009-02-01

    Phototherapy is a very effective method for treating most of the incurable skin diseases. A fluorescent light bulb is used as a conventional UV light source for this type of therapy. However, infrared radiation from the light source sometimes causes serious problems on patient's health. In addition, the normal part of the skin is irradiated when a large fluorescent light bulb is used. Moreover, a conventional UV irradiation system is heavy and has a short lifetime and a high electrical power consumption. Therefore, a new UV light source for solving the problems of phototherapy is required. To realize low-power-consumption, lightweight and long-lifetime systems, group III nitride-based UV-A1 light-emitting diodes (LEDs) were investigated. We examined the UV LED irradiation of Jurkat cell, which is a tumor cell and more sensitive to UV light than a healthy cell. The numbers of apoptotic and necrotic cells were confirmed to be the same using a UV LED and a conventional lamp system. The UV LED showed the possibility of realizing a new UV light source for phototherapy.

  12. Response of Bacillus subtilis spores to dehydration and UV irradiation at extremely low temperatures.

    Science.gov (United States)

    Dose, K; Klein, A

    1996-02-01

    Spores of Bacillus subtilis have been exposed to the conditions of extreme dehydration (argon/silica gel; simulated space vacuum) for up to 12 weeks at 298 K and 80 K in the dark. The inactivation has been correlated with the production of DNA-double strand-breaks. The temperature-dependence of the rate constants for inactivation or production of DNA-double strand-breaks is surprisingly low. Controls kept in the frozen state at 250 K for the same period of time showed no sign of deterioration. In another series of experiments the spores have been UV irradiated (253.7 nm) at 298 K, 200 K and 80 K after exposure to dehydrating conditions for 3 days. Fluence-effect relationships for inactivation, production of DNA-double strand-breaks and DNA-protein cross-links are presented. The corresponding F37-values for inactivation and production of DNA lesions are significantly increased only at 80 K (factor of 4 to 5). The data indicate that the low temperatures that prevail in the outer parts of the Solar System or at the nightside of Mars or the Moon are not sufficiently low to crucially inhibit inactivation by dehydration. Our data place further constraints on the panspermia hypothesis.

  13. UV Irradiation Accelerates Amyloid Precursor Protein (APP) Processing and Disrupts APP Axonal Transport

    Science.gov (United States)

    Almenar-Queralt, Angels; Falzone, Tomas L.; Shen, Zhouxin; Lillo, Concepcion; Killian, Rhiannon L.; Arreola, Angela S.; Niederst, Emily D.; Ng, Kheng S.; Kim, Sonia N.; Briggs, Steven P.; Williams, David S.

    2014-01-01

    Overexpression and/or abnormal cleavage of amyloid precursor protein (APP) are linked to Alzheimer's disease (AD) development and progression. However, the molecular mechanisms regulating cellular levels of APP or its processing, and the physiological and pathological consequences of altered processing are not well understood. Here, using mouse and human cells, we found that neuronal damage induced by UV irradiation leads to specific APP, APLP1, and APLP2 decline by accelerating their secretase-dependent processing. Pharmacological inhibition of endosomal/lysosomal activity partially protects UV-induced APP processing implying contribution of the endosomal and/or lysosomal compartments in this process. We found that a biological consequence of UV-induced γ-secretase processing of APP is impairment of APP axonal transport. To probe the functional consequences of impaired APP axonal transport, we isolated and analyzed presumptive APP-containing axonal transport vesicles from mouse cortical synaptosomes using electron microscopy, biochemical, and mass spectrometry analyses. We identified a population of morphologically heterogeneous organelles that contains APP, the secretase machinery, molecular motors, and previously proposed and new residents of APP vesicles. These possible cargoes are enriched in proteins whose dysfunction could contribute to neuronal malfunction and diseases of the nervous system including AD. Together, these results suggest that damage-induced APP processing might impair APP axonal transport, which could result in failure of synaptic maintenance and neuronal dysfunction. PMID:24573290

  14. Presence of UV-endonuclease sensitive sites in daughter DNA of UV-irradiated mammalian cells

    International Nuclear Information System (INIS)

    D'Ambrosio, S.; Setlow, R.B.

    1978-02-01

    Asynchronous Chinese hamster cells were irradiated with 10 Jm -2 uv radiation and 0.25 to 4 hours later pulse-labeled with [ 3 H]thymidine. Cells synchronized by shaking off mitotic and G 1 cells were irradiated in either the G 1 -phase or S-phase of the cell cycle and pulse-labeled with [ 3 H]thymidine in the S-phase. After a 12 to 14 hour chase in unlabeled medium, the DNA was extracted, incubated with Micrococcus luteus uv-endonuclease and sedimented in alkaline sucrose. The number of endonuclease sensitive sites decreased as the time between uv irradiation and pulse-labeling of daughter DNA increased. Further, there were significantly less endonuclease sensitive sites in the daughter DNA from cells irradiated in the G 1 -phase than in the S-phase. These data indicate that very few, if any, dimers are transferred from parental DNA to daughter DNA and that the dimers detected in daughter DNA may be due to the irradiation of replicating daughter DNA before labeling

  15. Gas chromatographic analysis of reactive carbonyl compounds formed from lipids upon UV-irradiation

    International Nuclear Information System (INIS)

    Dennis, K.J.; Shibamoto, T.

    1990-01-01

    Peroxidation of lipids produces carbonyl compounds; some of these, e.g., malonaldehyde and 4-hydroxynonenal, are genotoxic because of their reactivity with biological nucleophiles. Analysis of the reactive carbonyl compounds is often difficult. The methylhydrazine method developed for malonaldehyde analysis was applied to simultaneously measure the products formed from linoleic acid, linolenic acid, arachidonic acid, and squalene upon ultraviolet-irradiation (UV-irradiation). The photoreaction products, saturated monocarbonyl, alpha,beta-unsaturated carbonyls, and beta-dicarbonyls, were derivatized with methylhydrazine to give hydrazones, pyrazolines, and pyrazoles, respectively. The derivatives were analyzed by gas chromatography and gas chromatography-mass spectrometry. Lipid peroxidation products identified included formaldehyde, acetaldehyde, acrolein, malonaldehyde, n-hexanal, and 4-hydroxy-2-nonenal. Malonaldehyde levels formed upon 4 hr of irradiation were 0.06 micrograms/mg from squalene, 2.4 micrograms/mg from linolenic acid, and 5.7 micrograms/mg from arachidonic acid. Significant levels of acrolein (2.5 micrograms/mg) and 4-hydroxy-2-nonenal (0.17 micrograms/mg) were also produced from arachidonic acid upon 4 hr irradiation

  16. XANES Analysis of Organic Residues Produced from the UV Irradiation of Astrophysical Ice Analogs

    Science.gov (United States)

    Nuevo, M.; Milam, S N.; Sandford, S A.; De Gregorio, B T.; Cody, G D.; Kilcoyne, A L.

    2011-01-01

    Organic residues formed in the laboratory from the ultraviolet (UV) photo-irradiation or ion bombardment of astrophysical ice analogs have been extensively studied for the last 15 years with a broad suite of techniques, including infrared (IR) and UV spectroscopies, as well as mass spectrometry. Analyses of these materials show that they consist of complex mixtures of organic compounds stable at room temperature, mostly soluble, that have not been fully characterized. However, the hydrolysis products of these residues have been partly identified using chromatography techniques, which indicate that they contain molecular precursors of prebiotic interest such as amino acids, nitrile-bearing compounds, and amphiphilic compounds. In this study, we present the first X-ray absorption near-edge structure (XANES) spectroscopy measurements of three organic residues made from the UV irradiation of ices having different starting compositions. XANES spectra confirm the presence of different chemical functions in these residues, and indicate that they are rich in nitrogenand oxygen-bearing species. These data can be compared with XANES measurements of extraterrestrial materials. Finally, this study also shows how soft X rays can alter the chemical composition of samples.

  17. Enhancing the performance of electro-peroxone by incorporation of UV irradiation and BDD anodes.

    Science.gov (United States)

    Bensalah, Nasr; Bedoui, Ahmed

    2017-12-01

    In this work, the treatment of 4-nitrophenol (NP) in water by ozonation, electrolysis, electro-peroxone (EP), and photo-electro-peroxone (PEP) processes was investigated. PEP process is based on the combination of ozonation, UV irradiation, and electrolysis using a carbon felt cathode and a boron-doped diamond (BDD) anode. In this process, H 2 O 2 is electrochemically generated from reduction of O 2 in the ozone generator effluent at a carbon felt cathode. The in situ generated H 2 O 2 is simultaneously decomposed by UV-photolysis and by reaction with O 3 to form HO • radicals that can rapidly and non-selectively oxidize organic pollutants. The results showed that PEP is the most efficient process for a rapid NP degradation in water than the other individual and combined methods. In addition, PEP process was able to completely remove total organic carbon (TOC) from NP solution after consumption of 4.1 kWh/kg TOC removed. Hydroquinone, 1,2,4-trihydroxybenzene, oxalic and maleic acids were identified as the main intermediates of NP degradation. The addition of iron to NP solution did not significantly affect the efficiency of PEP process. The results demonstrated that the incorporation of BDD anodes and UV light in PEP process can significantly enhance the kinetics and minimize energy requirements.

  18. The combined action of UV irradiation and chemical treatment on the titanium surface of dental implants

    Energy Technology Data Exchange (ETDEWEB)

    Spriano, Silvia [Politecnico di Torino, Department of Applied Science and Technology, Corso Duca degli Abruzzi, 24-10129 Torino (Italy); Ferraris, Sara, E-mail: sara.ferraris@polito.it [Politecnico di Torino, Department of Applied Science and Technology, Corso Duca degli Abruzzi, 24-10129 Torino (Italy); Bollati, Daniele; Morra, Marco; Cassinelli, Clara [Nobil Bio Ricerche, Portacomaro (Italy); Lorenzon, Giorgio [Centro Chirurgico, Via Mallonetto, 47, 10032, Brandizzo Torino (Italy)

    2015-09-15

    Highlights: • A combined UV irradiation and H{sub 2}O{sub 2} treatment was applied to titanium surfaces. • A thin, homogeneous, not porous, crack-free and bioactive oxide layer was obtained. • The process significantly improves the biological response of titanium surfaces. • A clinical case demonstrates the effectiveness of the proposed treatment. - Abstract: The purpose of this paper is to describe an innovative treatment for titanium dental implants, aimed at faster and more effective osteointegration. The treatment has been performed with the use of hydrogen peroxide, whose action was enhanced by concomitant exposure to a source of ultraviolet light. The developed surface oxide layer was characterized from the physical and chemical points of view. Moreover osteoblast-like SaOS2 cells were cultured on treated and control titanium surfaces and cell behavior investigated by scanning electron microscope observation and gene expression measurements. The described process produces, in only 6 min, a thin, homogeneous, not porous, free of cracks and bioactive (in vitro apatite precipitation) oxide layer. High cell density, peculiar morphology and overexpression of several genes involved with osteogenesis have been observed on modified surfaces. The proposed process significantly improves the biological response of titanium surfaces, and is an interesting solution for the improvement of bone integration of dental implants. A clinical application of the described surfaces, with a 5 years follow-up, is reported in the paper, as an example of the effectiveness of the proposed treatment.

  19. Effect of UV irradiation and Nigella sativa protective role on the mice liver tissues

    International Nuclear Information System (INIS)

    El-Bahy, G.M.S.; Ismail, Z.M.K.

    1997-01-01

    The effect of UV irradiation on liver tissues of mice before and after feeding on the Nigella sativa L. for 4 and 7 days were investigated by following the variations in their infrared spectral features. The results showed that the exposure of experimental animals to UV radiations causes considerable changes in both proteins and PO 2 contents in the liver and the extent of changes depends on the energy of the source and time exposure. It was found that feeding of Nigella sativa L. during exposure for 4 days causes no significant effect on the UV induced changes in the liver tissues, while feeding for 7 days reduces the extent of the UV induced changes. Histological findings denoted that UV-Radiation causes different grades of damage in liver cells depending on the duration and type of radiation. Alcoholic extract of Nigella sativa seeds protected liver cells from being subjected to the degenerative changes. The present work investigates the possibility of applying Nigella sativa as a natural biological substance for curative purpose after UV radiation damage

  20. Sugar and Sugar Derivatives in Residues Produced from the UV Irradiation of Astrophysical Ice Analogs

    Science.gov (United States)

    Nuevo, M.; Sandford, S. A.; Cooper, G.

    2016-01-01

    A large variety and number of organic compounds of prebiotic interest are known to be present in carbonaceous chondrites. Among them, one sugar (dihydroxyacetone) as well as several sugar acids, sugar alcohols, and other sugar derivatives have been reported in the Murchison and Murray meteorites. Their presence, along with amino acids, amphiphiles, and nucleobases strongly suggests that molecules essential to life can form abiotically under astrophysical conditions. This hypothesis is supported by laboratory studies on the formation of complex organic molecules from the ultraviolet (UV) irradiation of simulated astrophysical ice mixtures consisting of H2O, CO, CO2, CH3OH, CH4, NH3, etc., at low temperature. In the past 15 years, these studies have shown that the organic residues recovered at room temperature contain amino acids, amphiphiles, nucleobases, as well as other complex organics. However, no systematic search for the presence of sugars and sugar derivatives in laboratory residues have been reported to date, despite the fact that those compounds are of primary prebiotic significance. Indeed, only small (up to 3 carbon atoms) sugar derivatives including glycerol and glyceric acid have been detected in residues so far.

  1. UV irradiation-initiated MMA polymerization to prepare microcapsules containing phase change paraffin

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Sude; Song, Guolin; Li, Wei; Fan, Pengfei; Tang, Guoyi [Institute of Advanced Materials, Graduated School at Shenzhen, Tsinghua University, Shenzhen 518055 (China)

    2010-10-15

    Microencapsulated phase change material (MEPCM), paraffin, with polymethylmethacrylate shell was prepared by introducing UV irradiation to an O/W emulsion polymerization for approximately 30 min under constant stirring. The results of differential scanning calorimetry analyses indicate that the latent heat and the content of paraffin of microcapsules are 101 J g{sup -1} and 61.2 wt%, respectively. The phase transition temperature of MEPCM ranges from 24 to 33 C. The MEPCM was characterized using scanning electron microscopy and Fourier transform infrared spectroscopy. Thermal gravimetric analysis results show that the MEPCM is degraded into two distinguishable steps. Accelerated thermal cycling tests also indicate that the MEPCM displays a good thermal reliability. Gypsum boards composed of as-prepared MEPCM show a good temperature-regulated property. Based on all these results, it can be concluded that the microencapsulated paraffin as MEPCMs have good potential for thermal energy storage purposes such as phase change material slurries, solar space heating applications, textiles and building materials. (author)

  2. UV irradiation of the blood in the therapy of torpid forms of gonorrheal uretritis

    International Nuclear Information System (INIS)

    Vasil'ev, M.M.; Zorin, S.P.

    1987-01-01

    Clinical efficiency of the IR-irradiation proper blood reinfusion (IRIPBR) method in therapy of torpid forms of gonorrheal uretritis, dynamics of such factors of the oxygen-dependent bactericidal system of polymorphonuclear neutrophils leukocytes (PMNL) as myeloperoxidases (MPO) and test of nitroblue tetrazolium (NBT-test) reduction as well as general quantity of PMNL in the course of immunotherapy by gonovaccine and pyrogenal and by the IRIPBR method have been studied in two groups of patients with gonorrheal uretritis (54 men). The patients of the first group (32) received peniciline, pyrogenal and gonovaccine injections, as well as local treatment according to the instruction, the patients of the second group (22) were prescribed instead of pyrogenal injections 3 procedures of IRIPBR on 2 ml autoblood basis per 1 kg of body mass (in average 130-150 ml) with further treatment by antibiotics. LK-5E has been used to carry out IRIPBR for blood UV irradiation. Blood has been irradiated by MD-73 M ''Izol'lda'' device. It is shown that IRIPBR causes statistically reliable increase of the number of circulating blood leucocytes including PMNL with simultaneous increase of MPO PMNL activity and the capability to generate pro-stimulations of O 2 - determined by the NBT-test

  3. UV-irradiated biodegradability of ethylene--propylene copolymers, LDPE, and I-PP in composting and culture environments.

    Science.gov (United States)

    Pandey, J K; Singh, R P

    2001-01-01

    The biodegradability of UV-irradiated films of ethylene--propylene copolymers (E--P copolymer), isotactic polypropylene (i-PP), and low-density polyethylene (LDPE), was measured in composting and culture environments by monitoring the variations in intrinsic viscosity [eta], weight loss per surface area, surface changes by SEM, colonization of fungus, chain scission, and evolution of hydroxyl and carbonyl groups by FT-IR spectroscopy. Photooxidation was used as a pretreatment for biodegradation of polymers. A systematic decrease in intrinsic viscosity [eta] and increase in carbonyl/hydroxyl regions in FT-IR spectra was found from 0 to 100-h irradiated samples. The degradation rate was strongly dependent on the composition of copolymers and markedly increased with decrease in ethylene content. Important surface erosion was detected after composting by SEM for longer UV-irradiated samples. It was estimated that chain-scission was directly related to photoirradiation.

  4. Amarginal contribution of selected carotenoids to the supression of UV-irradiation-induced lecithin peroxidation in hexane solution

    Directory of Open Access Journals (Sweden)

    DRAGAN CVETKOVIC

    2007-03-01

    Full Text Available The aim of this work was to study the anticipated antioxidant role of four selected carotenoids in mixtures with lecithin lipoidal compounds in hexane solution, under continuous UV-irradiation in three different ranges (UV-A, UV-B and UV-C. Two carotenes (b-carotene and licopene and two xantophylls (lutein and neoxanthin were employed to control the lipid peroxidation process generated by UV-irradiation, by scavenging the involved free radicals. The results show that while carotenoids undergo a substantial, structural dependent destruction (bleaching, which is highly dependent on energy of the UV-photons, their contribution to the expected suppression of lecithin peroxidation is of marginal importance, not exceeding a maximum of 20%. The marginal antioxidant behaviour has been attributed to a highly unordered hexane solution, where the scavenging action of the carotenoids becomes less competitive.

  5. Degradation of methyl orange using short-wavelength UV irradiation with oxygen microbubbles

    Energy Technology Data Exchange (ETDEWEB)

    Tasaki, Tsutomu; Wada, Tsubasa; Fujimoto, Kanji [JST Innovation Satellite Miyazaki, 1-1 Gakuen Kibanadai Nishi, Miyazaki 889-2192 (Japan); Kai, Shinji; Ohe, Kaoru; Oshima, Tatsuya; Baba, Yoshinari [Department of Applied Chemistry, Faculty of Engineering, University of Miyazaki, 1-1 Gakuen Kibanadai Nishi, Miyazaki 889-2192 (Japan); Kukizaki, Masato [Department of Material Development, Miyazaki Prefecture Industrial Technology Center, 16500-2 Higashi Kaminaka, Sadowara, Miyazaki 880-0303 (Japan)], E-mail: kukizaki@iri.pref.miyazaki.jp

    2009-03-15

    A novel wastewater treatment technique using 8 W low-pressure mercury lamps in the presence of uniform-sized microbubbles (diameter = 5.79 {mu}m) was investigated for the decomposition of methyl orange as a model compound in aqueous solution. Photodegradation experiments were conducted with a BLB black light blue lamp (365 nm), a UV-C germicidal lamp (254 nm) and an ozone lamp (185 nm + 254 nm) both with and without oxygen microbubbles. The results show that the oxygen microbubbles accelerated the decolorization rate of methyl orange under 185 + 254 nm irradiation. In contrast, the microbubbles under 365 and 254 nm irradiation were unaffected on the decolorization of methyl orange. It was found that the pseudo-zero order decolorization reaction constant in microbubble system is 2.1 times higher than that in conventional large bubble system. Total organic carbon (TOC) reduction rate of methyl orange was greatly enhanced by oxygen microbubble under 185 + 254 nm irradiation, however, TOC reduction rate by nitrogen microbubble was much slower than that with 185 + 254 nm irradiation only. Possible reaction mechanisms for the decolorization and mineralization of methyl orange both with oxygen and nitrogen mirobubbles were proposed in this study.

  6. Degradation of methyl orange using short-wavelength UV irradiation with oxygen microbubbles.

    Science.gov (United States)

    Tasaki, Tsutomu; Wada, Tsubasa; Fujimoto, Kanji; Kai, Shinji; Ohe, Kaoru; Oshima, Tatsuya; Baba, Yoshinari; Kukizaki, Masato

    2009-03-15

    A novel wastewater treatment technique using 8 W low-pressure mercury lamps in the presence of uniform-sized microbubbles (diameter = 5.79 microm) was investigated for the decomposition of methyl orange as a model compound in aqueous solution. Photodegradation experiments were conducted with a BLB black light blue lamp (365 nm), a UV-C germicidal lamp (254 nm) and an ozone lamp (185 nm+254 nm) both with and without oxygen microbubbles. The results show that the oxygen microbubbles accelerated the decolorization rate of methyl orange under 185+254 nm irradiation. In contrast, the microbubbles under 365 and 254 nm irradiation were unaffected on the decolorization of methyl orange. It was found that the pseudo-zero order decolorization reaction constant in microbubble system is 2.1 times higher than that in conventional large bubble system. Total organic carbon (TOC) reduction rate of methyl orange was greatly enhanced by oxygen microbubble under 185+254 nm irradiation, however, TOC reduction rate by nitrogen microbubble was much slower than that with 185+254 nm irradiation only. Possible reaction mechanisms for the decolorization and mineralization of methyl orange both with oxygen and nitrogen mirobubbles were proposed in this study.

  7. Rapid and apparently error-prone excision repair of nonreplicating UV-irradiated plasmids in Xenopus laevis oocytes.

    OpenAIRE

    Hays, J B; Ackerman, E J; Pang, Q S

    1990-01-01

    Repair of UV-irradiated plasmid DNA microinjected into frog oocytes was measured by two techniques: transformation of repair-deficient (delta uvrB delta recA delta phr) bacteria, and removal of UV endonuclease-sensitive sites (ESS). Transformation efficiencies relative to unirradiated plasmids were used to estimate the number of lethal lesions; the latter were assumed to be Poisson distributed. These estimates were in good agreement with measurements of ESS. By both criteria, plasmid DNA was ...

  8. Enhanced reactivation of UV-irradiated adenovirus 2 in HeLa cells treated with non-mutagenic chemical agents

    Energy Technology Data Exchange (ETDEWEB)

    Piperakis, S.M.; McLennan, A.G. (Liverpool Univ. (UK). Dept. of Biochemistry)

    1985-03-01

    Treatment of HeLa cells with ethanol and sodium arsenite, compounds which are known to elicit the heat-shock response, before infection with UV-irradiated adenovirus 2 has been found to result in the enhanced reactivation of the damaged virus in a manner similar to that obtained by pre-irradiation or heating of the cells. Enhanced reactivation may be the result of the inhibition of DNA synthesis caused by these agents since hydroxyurea also produced a significant enhancement.

  9. Enhanced reactivation of UV-irradiated adenovirus 2 in HeLa cells treated with non-mutagenic chemical agents.

    Science.gov (United States)

    Piperakis, S M; McLennan, A G

    1985-03-01

    Treatment of HeLa cells with ethanol and sodium arsenite, compounds which are known to elicit the heat-shock response, before infection with UV-irradiated adenovirus 2 has been found to result in the enhanced reactivation of the damaged virus in a manner similar to that obtained by pre-irradiation or heating of the cells. Enhanced reactivation may be the result of the inhibition of DNA synthesis caused by these agents since hydroxyurea also produced a significant enhancement.

  10. Impact of Dissolved Oxygen during UV-Irradiation on the Chemical Composition and Function of CHO Cell Culture Media.

    Science.gov (United States)

    Meunier, Sarah M; Todorovic, Biljana; Dare, Emma V; Begum, Afroza; Guillemette, Simon; Wenger, Andrew; Saxena, Priyanka; Campbell, J Larry; Sasges, Michael; Aucoin, Marc G

    2016-01-01

    Ultraviolet (UV) irradiation is advantageous as a sterilization technique in the biopharmaceutical industry since it is capable of targeting non-enveloped viruses that are typically challenging to destroy, as well as smaller viruses that can be difficult to remove via conventional separation techniques. In this work, we investigated the influence of oxygen in the media during UV irradiation and characterized the effect on chemical composition using NMR and LC-MS, as well as the ability of the irradiated media to support cell culture. Chemically defined Chinese hamster ovary cell growth media was irradiated at high fluences in a continuous-flow UV reactor. UV-irradiation caused the depletion of pyridoxamine, pyridoxine, pyruvate, riboflavin, tryptophan, and tyrosine; and accumulation of acetate, formate, kynurenine, lumichrome, and sarcosine. Pyridoxamine was the only compound to undergo complete degradation within the fluences considered; complete depletion of pyridoxamine was observed at 200 mJ/cm2. Although in both oxygen- and nitrogen-saturated media, the cell culture performance was affected at fluences above 200 mJ/cm2, there was less of an impact on cell culture performance in the nitrogen-saturated media. Based on these results, minimization of oxygen in cell culture media prior to UV treatment is recommended to minimize the negative impact on sensitive media.

  11. Elimination of pharmaceutical residues in biologically pre-treated hospital wastewater using advanced UV irradiation technology: a comparative assessment.

    Science.gov (United States)

    Köhler, C; Venditti, S; Igos, E; Klepiszewski, K; Benetto, E; Cornelissen, A

    2012-11-15

    UV irradiation technology as a membrane bioreactor (MBR) post-treatment was investigated and assessed. Both UV low pressure (LP) and medium pressure (MP) lamps were examined. The technology was installed in a pilot plant treating hospital wastewater to provide the study with adequate field data. The effect of the UV irradiation was enhanced with varying dosages of H2O2 to establish an advanced oxidation process (AOP). The efficiency of the pharmaceutical removal process was assessed by examining 14 micropollutants (antibiotics, analgesics, anticonvulsants, beta-blockers, cytostatics and X-ray contrast media) which are typically released by hospitals and detected with liquid chromatography coupled tandem mass spectrometry (LC-MS/MS). While the MBR treatment generally showed only a low degradation capacity for persistent pharmaceuticals, much better degradation was obtained by applying UV irradiation and H2O2 as AOP. The "conventional" cost-benefit analysis of the different technology options taking into account both electrical energy consumption and pharmaceutical removal efficiency, revealed clearly better performance of low pressure UV lamps as AOP. However, a holistic comparison between the different scenarios was carried out by evaluating their environmental impacts using the life cycle assessment (LCA) methodology. Decisive advantages were highlighted to include this approach in the decision making process. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Elimination of pharmaceutical residues in biologically pre-treated hospital wastewater using advanced UV irradiation technology: A comparative assessment

    International Nuclear Information System (INIS)

    Köhler, C.; Venditti, S.; Igos, E.; Klepiszewski, K.; Benetto, E.; Cornelissen, A.

    2012-01-01

    UV irradiation technology as a membrane bioreactor (MBR) post-treatment was investigated and assessed. Both UV low pressure (LP) and medium pressure (MP) lamps were examined. The technology was installed in a pilot plant treating hospital wastewater to provide the study with adequate field data. The effect of the UV irradiation was enhanced with varying dosages of H 2 O 2 to establish an advanced oxidation process (AOP). The efficiency of the pharmaceutical removal process was assessed by examining 14 micropollutants (antibiotics, analgesics, anticonvulsants, beta-blockers, cytostatics and X-ray contrast media) which are typically released by hospitals and detected with liquid chromatography coupled tandem mass spectrometry (LC–MS/MS). While the MBR treatment generally showed only a low degradation capacity for persistent pharmaceuticals, much better degradation was obtained by applying UV irradiation and H 2 O 2 as AOP. The “conventional” cost-benefit analysis of the different technology options taking into account both electrical energy consumption and pharmaceutical removal efficiency, revealed clearly better performance of low pressure UV lamps as AOP. However, a holistic comparison between the different scenarios was carried out by evaluating their environmental impacts using the life cycle assessment (LCA) methodology. Decisive advantages were highlighted to include this approach in the decision making process.

  13. Elimination of pharmaceutical residues in biologically pre-treated hospital wastewater using advanced UV irradiation technology: A comparative assessment

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, C., E-mail: christian.koehler@tudor.lu [Public Research Centre Henri Tudor/Resource Centre for Environmental Technologies, 66 rue de Luxembourg, BP 144, L-4002 Esch-sur-Alzette (Luxembourg); Venditti, S.; Igos, E.; Klepiszewski, K.; Benetto, E.; Cornelissen, A. [Public Research Centre Henri Tudor/Resource Centre for Environmental Technologies, 66 rue de Luxembourg, BP 144, L-4002 Esch-sur-Alzette (Luxembourg)

    2012-11-15

    UV irradiation technology as a membrane bioreactor (MBR) post-treatment was investigated and assessed. Both UV low pressure (LP) and medium pressure (MP) lamps were examined. The technology was installed in a pilot plant treating hospital wastewater to provide the study with adequate field data. The effect of the UV irradiation was enhanced with varying dosages of H{sub 2}O{sub 2} to establish an advanced oxidation process (AOP). The efficiency of the pharmaceutical removal process was assessed by examining 14 micropollutants (antibiotics, analgesics, anticonvulsants, beta-blockers, cytostatics and X-ray contrast media) which are typically released by hospitals and detected with liquid chromatography coupled tandem mass spectrometry (LC-MS/MS). While the MBR treatment generally showed only a low degradation capacity for persistent pharmaceuticals, much better degradation was obtained by applying UV irradiation and H{sub 2}O{sub 2} as AOP. The 'conventional' cost-benefit analysis of the different technology options taking into account both electrical energy consumption and pharmaceutical removal efficiency, revealed clearly better performance of low pressure UV lamps as AOP. However, a holistic comparison between the different scenarios was carried out by evaluating their environmental impacts using the life cycle assessment (LCA) methodology. Decisive advantages were highlighted to include this approach in the decision making process.

  14. Semi-conservative synthesis of DNA in UV-sensitive mutant cells of Chinese hamster after UV-irradiation

    International Nuclear Information System (INIS)

    Vikhanskaya, F.L.; Khrebtukova, I.A.; Manuilova, E.S.

    1985-01-01

    A study was made of the rate of semi-conservative DNA synthesis in asynchronous UV-resistant (clone V79) and UV-sensitive clones (VII and XII) of Chinese hamster cells after UV-irradiation. In all 3 clones studied, UV-irradiation (5-30 J/m 2 ) induced a decrease in the rate of DNA synthesis during the subsequent 1-2 h. In the resistant clone (V79) recovery of DNA synthesis rate started after the first 2 h post-irradiation (5 J/m 2 ) and by the 3rd hour reached its maximum value, which constituted 70% of that observed in control, non-irradiated cells. The UV-sensitive mutant clones VII and XII showed no recovery in the rate of DNA synthesis during 6-7 h post-irradiation. The results obtained show that the survival of cells is correlated with the ability of DNA synthesis to recover after UV-irradiation in 3 clones studied. The observed recovery of UV-inhibited DNA synthesis in mutant clones may be due to certain defects in DNA repair. (orig.)

  15. Investigation into the potential chemical mechanism of the pro-oxidant activity of carotenoids with liposomes under UV-irradiation

    Directory of Open Access Journals (Sweden)

    Cvetković Dragan J.

    2017-01-01

    Full Text Available This study focuses on the behavior of β-carotene and lutein inside multilamellar liposomes under continuous UV-irradiation. The liposomes were obtained by the thin film method and carotenoids (Crts were incorporated by mixing at various concentrations (0.005, 0.0075, 0.02, 0.07 and 0.5 mol %. Liposomes formation and the presence of Crts inside them were confirmed by SEM microscopy and FT-IR spectroscopy, respectively. The antioxidant/pro- -oxidant activity of Crts inside liposomes was determined by the thiobarbituric acid–malondialdehyde (TBA–MDA test. The investigated Crts acted more or less unexpected (as pro-oxidants inside the lipid bilayers, interacting with the UV-produced lipid radicals and simultaneously suffering under the UV-irradiation. Their pro-oxidant activity with liposomes and under UV-irradiation could be explained by the formation of unstable adducts in the reaction with peroxyl radicals, or by Crts-cation radicals formation via the electron transfer mechanism. Such tentatively unexpected behavior of carotenoids should be taken into consideration in further carotenoids-based UV-filters projections in cosmetic formulations for skin protection. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR-34012

  16. Observation of the degradation of three types of plastic pellets exposed to UV irradiation in three different environments.

    Science.gov (United States)

    Cai, Liqi; Wang, Jundong; Peng, Jinping; Wu, Ziqing; Tan, Xiangling

    2018-02-14

    Plastic debris represents one of the most prevalent and persistent pollution problems in the marine environment. In particular, microplastics that are mainly degraded from larger plastic debris have become a growing environmental concern. However, studies on the degradation of plastics in the aquatic environment that hydrobios reside in have been limited, while several studies regarding the degradation of plastics have been conducted under outdoor or accelerated weathering conditions. Thus, observation of the degradation of three types of virgin plastic pellets exposed to UV irradiation in three different environments (i.e., simulated seawater, ultrapure water, and a waterless (air) condition) was carried out. Data on the changes in physical and chemical properties were collected. The FTIR spectra showed that hydroxyl groups and carbonyl groups developed in three types of weathered plastic pellets under the air and ultrapure water environmental conditions after 3months of UV irradiation, while only carbonyl groups were found in plastic pellets in the simulated seawater environment. In contrast, the Raman spectra showed no significant changes in the weathered plastic pellets, but there were different intensities of characteristic peaks after exposure to UV irradiation. In addition, SEM images illustrated that granular oxidation, cracks and flakes were common patterns during degradation, and the plastic pellets in the three different environments experienced different levels of chemical weathering. We suggest that further studies on the degradation processes of plastic debris are needed to predict the fate of plastic debris in the environment. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Chlorine inactivation of Tubifex tubifex in drinking water and the synergistic effect of sequential inactivation with UV irradiation and chlorine.

    Science.gov (United States)

    Nie, Xiao-Bao; Li, Zhi-Hong; Long, Yuan-Nan; He, Pan-Pan; Xu, Chao

    2017-06-01

    The inactivation of Tubifex tubifex is important to prevent contamination of drinking water. Chlorine is a widely-used disinfectant and the key factor in the inactivation of T. tubifex. This study investigated the inactivation kinetics of chlorine on T. tubifex and the synergistic effect of the sequential use of chlorine and UV irradiation. The experimental results indicated that the Ct (concentration × time reaction ) concept could be used to evaluate the inactivation kinetics of T. tubifex with chlorine, thus allowing for the use of a simpler Ct approach for the assessment of T. tubifex chlorine inactivation requirements. The inactivation kinetics of T. tubifex by chlorine was found to be well-fitted to a delayed pseudo first-order Chick-Watson expression. Sequential experiments revealed that UV irradiation and chlorine worked synergistically to effectively inactivate T. tubifex as a result of the decreased activation energy, E a , induced by primary UV irradiation. Furthermore, the inactivation effectiveness of T. tubifex by chlorine was found to be affected by several drinking water quality parameters including pH, turbidity, and chemical oxygen demand with potassium permanganate (COD Mn ) concentration. High pH exhibited pronounced inactivation effectiveness and the decrease in turbidity and COD Mn concentrations contributed to the inactivation of T. tubifex. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Whole tumor antigen vaccination using dendritic cells: Comparison of RNA electroporation and pulsing with UV-irradiated tumor cells

    Directory of Open Access Journals (Sweden)

    Benencia Fabian

    2008-04-01

    Full Text Available Abstract Because of the lack of full characterization of tumor associated antigens for solid tumors, whole antigen use is a convenient approach to tumor vaccination. Tumor RNA and apoptotic tumor cells have been used as a source of whole tumor antigen to prepare dendritic cell (DC based tumor vaccines, but their efficacy has not been directly compared. Here we compare directly RNA electroporation and pulsing of DCs with whole tumor cells killed by ultraviolet (UV B radiation using a convenient tumor model expressing human papilloma virus (HPV E6 and E7 oncogenes. Although both approaches led to DCs presenting tumor antigen, electroporation with tumor cell total RNA induced a significantly higher frequency of tumor-reactive IFN-gamma secreting T cells, and E7-specific CD8+ lymphocytes compared to pulsing with UV-irradiated tumor cells. DCs electroporated with tumor cell RNA induced a larger tumor infiltration by T cells and produced a significantly stronger delay in tumor growth compared to DCs pulsed with UV-irradiated tumor cells. We conclude that electroporation with whole tumor cell RNA and pulsing with UV-irradiated tumor cells are both effective in eliciting antitumor immune response, but RNA electroporation results in more potent tumor vaccination under the examined experimental conditions.

  19. OMI/Aura Surface UV Irradiance 1-orbit L2 Swath 13x24 km V003 (OMUVB) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — The Aura Ozone Monitoring Instrument (OMI) Version 003 Surface UV Irradiance Product (OMUVB) is now available from the NASA Goddard Earth Sciences Data and...

  20. Comparison of UV irradiance measurements at Summit, Greenland; Barrow, Alaska; and South Pole, Antarctica

    Directory of Open Access Journals (Sweden)

    G. Bernhard

    2008-08-01

    Full Text Available An SUV-150B spectroradiometer for measuring solar ultraviolet (UV irradiance was installed at Summit, Greenland, in August 2004. Here we compare the initial data from this new location with similar measurements from Barrow, Alaska, and South Pole. Measurements of irradiance at 345 nm performed at equivalent solar zenith angles (SZAs are almost identical at Summit and South Pole. The good agreement can be explained with the similar location of the two sites on high-altitude ice caps with high surface albedo. Clouds attenuate irradiance at 345 nm at both sites by less than 6% on average, but can reduce irradiance at Barrow by more than 75%. Clear-sky measurements at Barrow are smaller than at Summit by 14% in spring and 36% in summer, mostly due to differences in surface albedo and altitude. Comparisons with model calculations indicate that aerosols can reduce clear-sky irradiance at Summit by 4–6%; aerosol influence is largest in April. Differences in total ozone at the three sites have a large influence on the UV Index. At South Pole, the UV Index is on average 20–80% larger during the ozone hole period than between January and March. At Summit, total ozone peaks in April and UV Indices in spring are on average 10–25% smaller than in the summer. Maximum UV Indices ever observed at Summit, Barrow, and South Pole are 6.7, 5.0, and 4.0, respectively. The larger value at Summit is due to the site's lower latitude. For comparable SZAs, average UV Indices measured during October and November at South Pole are 1.9–2.4 times larger than measurements during March and April at Summit. Average UV Indices at Summit are over 50% greater than at Barrow because of the larger cloud influence at Barrow.

  1. Assessment of DNA damage and repair in Mycobacterium terrae after exposure to UV irradiation.

    Science.gov (United States)

    Bohrerova, Z; Linden, K G

    2006-11-01

    Ultraviolet (UV) irradiation for drinking water treatment was examined for inactivation and subsequent dark and photo-repair of Mycobacterium terrae. UV sources tested were low pressure (monochromatic, 254 nm) and medium pressure (polychromatic UV output) Hg lamps. UV exposure resulted in inactivation, and was followed by dark or photo-repair experiments. Inactivation and repair were quantified utilizing a molecular-based endonuclease sensitive site (ESS) assay and conventional colony forming unit (CFU) viability assay. Mycobacterium terrae was more resistant to UV disinfection compared to many other bacteria, with approximately 2-log reduction at a UV fluence of 10 mJ cm(-2) ; similar to UV inactivation of M. tuberculosis. There was no difference in inactivation between monochromatic or polychromatic UV lamps. Mycobacterium terrae did not undergo detectable dark repair. Photo-repair resulted in recovery from inactivation by approximately 0.5-log in less than 30 min for both UV lamp systems. Mycobacterium terrae is able to photo-repair DNA damage within a short timeframe. The number of pyrimidine dimers induced by UV light were similar for Escherichia coli and M. terrae, however, this similarity did not hold true for viability results. There is no practical difference between UV sources for disinfection or prevention of DNA repair for M. terrae. The capability of M. terrae to photo-repair UV damage fairly quickly is important for wastewater treatment applications where disinfected effluent is exposed to sunlight. Finally, molecular based assay results should be evaluated with respect to differences in the nucleic acid content of the test micro-organism.

  2. Photodegradation of gemfibrozil in aqueous solution under UV irradiation: kinetics, mechanism, toxicity, and degradation pathways.

    Science.gov (United States)

    Ma, Jingshuai; Lv, Wenying; Chen, Ping; Lu, Yida; Wang, Fengliang; Li, Fuhua; Yao, Kun; Liu, Guoguang

    2016-07-01

    The lipid regulator gemfibrozil (GEM) has been reported to be persistent in conventional wastewater treatment plants. This study investigated the photolytic behavior, toxicity of intermediate products, and degradation pathways of GEM in aqueous solutions under UV irradiation. The results demonstrated that the photodegradation of GEM followed pseudo-first-order kinetics, and the pseudo-first-order rate constant was decreased markedly with increasing initial concentrations of GEM and initial pH. The photodegradation of GEM included direct photolysis via (3)GEM(*) and self-sensitization via ROS, where the contribution rates of degradation were 0.52, 90.05, and 8.38 % for ·OH, (1)O2, and (3)GEM(*), respectively. Singlet oxygen ((1)O2) was evidenced by the molecular probe compound, furfuryl alcohol (FFA), and was identified as the primary reactive species in the photolytic process. The steady-state concentrations of (1)O2 increased from (0.324 ± 0.014) × 10(-12) to (1.021 ± 0.040) × 10(-12) mol L(-1), as the initial concentrations of GEM were increased from 5 to 20 mg L(-1). The second-order rate constant for the reaction of GEM with (1)O2 was calculated to be 2.55 × 10(6) M(-1) s(-1). The primary transformation products were identified using HPLC-MS/MS, and possible photodegradation pathways were proposed by hydroxylation, aldehydes reactions, as well as the cleavage of ether side chains. The toxicity of phototransformation product evaluation revealed that photolysis potentially provides a critical pathway for GEM toxicity reduction in potable water and wastewater treatment facilities.

  3. Rad51 recombinase prevents Mre11 nuclease-dependent degradation and excessive PrimPol-mediated elongation of nascent DNA after UV irradiation

    Science.gov (United States)

    Vallerga, María Belén; Mansilla, Sabrina F.; Federico, María Belén; Bertolin, Agustina P.; Gottifredi, Vanesa

    2015-01-01

    After UV irradiation, DNA polymerases specialized in translesion DNA synthesis (TLS) aid DNA replication. However, it is unclear whether other mechanisms also facilitate the elongation of UV-damaged DNA. We wondered if Rad51 recombinase (Rad51), a factor that escorts replication forks, aids replication across UV lesions. We found that depletion of Rad51 impairs S-phase progression and increases cell death after UV irradiation. Interestingly, Rad51 and the TLS polymerase polη modulate the elongation of nascent DNA in different ways, suggesting that DNA elongation after UV irradiation does not exclusively rely on TLS events. In particular, Rad51 protects the DNA synthesized immediately before UV irradiation from degradation and avoids excessive elongation of nascent DNA after UV irradiation. In Rad51-depleted samples, the degradation of DNA was limited to the first minutes after UV irradiation and required the exonuclease activity of the double strand break repair nuclease (Mre11). The persistent dysregulation of nascent DNA elongation after Rad51 knockdown required Mre11, but not its exonuclease activity, and PrimPol, a DNA polymerase with primase activity. By showing a crucial contribution of Rad51 to the synthesis of nascent DNA, our results reveal an unanticipated complexity in the regulation of DNA elongation across UV-damaged templates. PMID:26627254

  4. Preparation, characterization and application of nanosized copper ferrite photocatalysts for dye degradation under UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zaharieva, Katerina, E-mail: zaharieva@ic.bas.bg [Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Block 11, 1113 Sofia (Bulgaria); Rives, Vicente, E-mail: vrives@usal.es [GIR-QUESCAT, Dpto. Química Inorgánica, Universidad de Salamanca, 37008 Salamanca (Spain); Tsvetkov, Martin, E-mail: mptsvetkov@gmail.com [Faculty of Chemistry and Pharmacy, St. Kliment Ohridski University of Sofia, 1 J. Bourchier Blvd., 1164 Sofia (Bulgaria); Cherkezova-Zheleva, Zara, E-mail: zzhel@ic.bas.bg [Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Block 11, 1113 Sofia (Bulgaria); Kunev, Boris, E-mail: bkunev@ic.bas.bg [Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Block 11, 1113 Sofia (Bulgaria); Trujillano, Raquel, E-mail: rakel@usal.es [GIR-QUESCAT, Dpto. Química Inorgánica, Universidad de Salamanca, 37008 Salamanca (Spain); Mitov, Ivan, E-mail: mitov@ic.bas.bg [Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Block 11, 1113 Sofia (Bulgaria); Milanova, Maria, E-mail: nhmm@wmail.chem.uni-sofia.bg [Faculty of Chemistry and Pharmacy, St. Kliment Ohridski University of Sofia, 1 J. Bourchier Blvd., 1164 Sofia (Bulgaria)

    2015-06-15

    {sup −3} min{sup −1}) for degradation of organic dye Malachite green under UV irradiation. - Highlights: • Copper ferrites via co-precipitation, mechanochemical and/or thermal treatment. • Nano ferrites show a superparamagnetic and collective magnetic excitations nature. • The co-precipitated Cu{sub 0.25}Fe{sub 2.75}O{sub 4} posses the highest photocatalytic activity. • The amount adsorbed Malachite Green by catalyst depends on the preparation method. • The prepared copper ferrites can be applicable as cheap adsorbents and catalysts.

  5. Preparation, characterization and application of nanosized copper ferrite photocatalysts for dye degradation under UV irradiation

    International Nuclear Information System (INIS)

    Zaharieva, Katerina; Rives, Vicente; Tsvetkov, Martin; Cherkezova-Zheleva, Zara; Kunev, Boris; Trujillano, Raquel; Mitov, Ivan; Milanova, Maria

    2015-01-01

    Malachite green under UV irradiation. - Highlights: • Copper ferrites via co-precipitation, mechanochemical and/or thermal treatment. • Nano ferrites show a superparamagnetic and collective magnetic excitations nature. • The co-precipitated Cu 0.25 Fe 2.75 O 4 posses the highest photocatalytic activity. • The amount adsorbed Malachite Green by catalyst depends on the preparation method. • The prepared copper ferrites can be applicable as cheap adsorbents and catalysts

  6. Differential expression of bean chitinase genes by virus infection, chemical treatment and UV irradiation

    International Nuclear Information System (INIS)

    Margis-Pinheiro, M.; Martin, C.; Didierjean, L.; Burkard, G.

    1993-01-01

    Three chitinases have been shown previously to be induced upon various stresses of bean leaves. Time course studies of mRNA accumulation of two of them (P3- and P4-chitinases) have been studied upon virus infection, mercuric chloride treatment and UV irradiation. In alfalfa mosaic virus (AlMV)-infected plants both mRNAs, absent in uninfected bean leaves, become detectable 36 h after inoculation. A maximum level of mRNAs is reached 84 h after inoculation and, whereas the amount of P3-ch mRNA decreases soon after having reached the maximum, the amount of P4-ch mRNA remains at high levels for several days. In mercuric chloride-treated leaves P4-ch mRNA becomes detectable 1-1.5 h after onset of treatment and a maximum level is observed between 6 h and 24 h after treatment; P3-ch mRNA becomes detectable later than P4-ch mRNA in treated leaves and reaches a maximum as late as 18 h after treatment has been applied. UV light also induces the synthesis of both mRNAs but, here again, important differences are observed in the accumulation rate of the two transcripts. The relative amounts of each mRNA induced by the different stresses have been compared. The most effective inducer of P3-ch mRNA is AlMV. In contrast, mercuric chloride induces P4-ch mRNA more efficiently than AlMV or UV light. We have also determined the complete nucleotide sequence of the cDNA encoding P3-chitinase that has been isolated from a cDNA library by using the cucumber lysozyme-chitinase cDNA as a probe. The 1072 bp P3-ch cDNA encodes a mature protein of 268 amino acid residues and the 25 residue NH2-terminal signal peptide of the precursor. Because of its high structural homology to the cucumber and Arabidopsis acidic chitinases as well as to the N-terminal amino acid sequence of the bifunctional lysozyme-chitinase from P. quinquifolia, bean P3-chitinase can be considered to belong to the class III chitinases. Southern blot analysis of bean genomic DNA revealed that P3-chitinase is encoded by a

  7. Infrared spectral investigations of UV irradiated nucleobases adsorbed on mineral surfaces

    Science.gov (United States)

    Fornaro, Teresa; Brucato, John Robert; Pace, Emanuele; Guidi, Mariangela Cestelli; Branciamore, Sergio; Pucci, Amaranta

    2013-09-01

    through in situ UV irradiation experiments. Experimental results confirm the high intrinsic photostability of such molecules, because a rather low probability of interaction between UV radiation and nucleobases was estimated, and furthermore indicate that cytosine and hypoxanthine have a greater photostability compared to adenine and uracil, both pure and adsorbed onto magnesium oxide and forsterite.

  8. Effect of UV irradiation (253.7 nm) on free Legionella and Legionella associated with its amoebae hosts.

    Science.gov (United States)

    Cervero-Aragó, Sílvia; Sommer, Regina; Araujo, Rosa M

    2014-12-15

    Water systems are the primary reservoir for Legionella spp., where the bacteria live in association with other microorganisms, such as free-living amoebae. A wide range of disinfection treatments have been studied to control and prevent Legionella colonization but few of them were performed considering its relation with protozoa. In this study, the effectiveness of UV irradiation (253.7 nm) using low-pressure lamps was investigated as a disinfection method for Legionella and amoebae under controlled laboratory conditions. UV treatments were applied to 5 strains of Legionella spp., 4 strains of free-living amoeba of the genera Acanthamoeba and Vermamoeba, treating separately trophozoites and cysts, and to two different co-cultures of Legionella pneumophila with the Acanthamoeba strains. No significant differences in the UV inactivation behavior were observed among Legionella strains tested which were 3 logs reduced for fluences around 45 J/m(2). UV irradiation was less effective against free-living amoebae; which in some cases required up to 990 J/m(2) to obtain the same population reduction. UV treatment was more effective against trophozoites compared to cysts; moreover, inactivation patterns were clearly different between the genus Acanthamoeba and Vermamoeba. For the first time data about Vermamoeba vermiformis UV inactivation has been reported in a study. Finally, the results showed that the association of L. pneumophila with free-living amoebae decreases the effectiveness of UV irradiation against the bacteria in a range of 1.5-2 fold. That fact demonstrates that the relations established between different microorganisms in the water systems can modify the effectiveness of the UV treatments applied. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Role of gene 59 of bacteriophage T4 in repair of uv-irradiated and alkylated DNA in vivo

    International Nuclear Information System (INIS)

    Wu, R.; Wu, J.L.; Yeh, Y.C.

    1975-01-01

    Nonsense mutants in gene 59 (amC5, am HL628) were used to study the role of this gene in the repair of uv-damaged and alkylated DNA of bacteriophage T4 in vivo. The higher sensitivity to uv irradiation and alkylation of gene 59 mutants after exposure to these agents was established by a comparison of the survival fractions with wild type. Zonal centrifugal analysis of both parental and nascent mutant intracellular DNA molecules after uv irradiation showed that immediately after exposure the size of single-stranded DNA fragments was the same as the wild-type intracellular DNA. However, the capability of rejoining fragmented intracellular DNA was greatly reduced in the mutant. In contrast, the wild-type-infected cells under the same condition resumed DNA replication and repaired its DNA to normal size. Methyl methanesulfonate induced more randomly fragmented intracellular DNA, when compared to uv irradiation. The rate of rejoining under these conditions as judged from their sedimentation profiles was also greatly reduced in mutant-infected cells. Further evidence is presented that uv repair is not a simple consequence of arrested DNA replication, which is a phenotype of the mutant when infected in a nonpermissive host, Escherichia coli B(su - ), but rather that the DNA repair function of gene 59 is independent of the replication function. These and other data presented indicate that a product(s) of gene 59 is essential for both repair of uv lesions and repair of alkylation damage of DNA in vivo. It is suggested that gene 59 may have two functions during viral development: DNA replication and replication repair of DNA molecules

  10. Detailed Study of the Formation of Sugar Derivatives Produced from the UV Irradiation of Astrophysical Ice Analogs

    Science.gov (United States)

    Nuevo, Michel; Cooper, George; Saunders, John; Buffo, Christina E.; Materese, Christopher K.; Sandford, Scott A.

    2018-01-01

    Carbonaceous meteorites such as Murchison contain a large variety of organic compounds of astrobiological interest such as amino acids, other amphiphilic compounds, functionalized nitrogen heterocycles (including nucleobases), functionalized polycylic aromatic hydro-carbons (including quinones), and sugar derivatives. The presence of such a broad variety of organics in meteorites strongly suggests that molecules essential to life can form abiotically under astrophysical conditions. This hypothesis is strongly supported by laboratory studies in which astrophysical ice analogs (i.e., mixtures of H2O, CO, CO2, CH3OH, CH4, NH3, etc.) are subjected to ultraviolet (UV) irradiation at low temperature (less than 15 K) to simulate cold interstellar environments. These studies have shown that the organic residues recovered at room temperature after irradiation contain organic compounds that are very similar to those found in meteorites. No systematic search for the presence of sugar derivatives in laboratory residues had been carried out until the recent detection of ribose, the sugar of RNA, as well as other sugars, sugar alcohols, and sugar acids in one residue produced from the UV irradiation of an ice mixture containing H2O, CH3OH, and NH3 at 80 K. In this work, we present a detailed study of the formation of sugar derivatives contained in organic residues that are produced from the UV irradiation of ice mixtures of different starting compositions (H2O, CH3OH, CO, CO2, and/or NH3) at less than 15 K. While the presence of sugar alcohols, sugars, and sugar acids-in some cases with up to 6 carbon atoms-could be confirmed in all these residues, their distribution was shown to vary with the composition of the starting ices. In particular, only a few ices result in the formation of sugar derivatives displaying a distribution that resembles that of meteorites, in which sugar alcohols and sugar acids are very abundant while sugars are mostly absent.

  11. Mitochondrial genetics X: Effects of UV irradiation on transmission and recombination of mitochondrial genes in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Dujon, B.; Kruszewska, A.; Slonimski, P.P.; Bolotin-Fukuhara, M.; Coen, D.; Deutsch, J.; Netter, P.; Weill, L.

    1975-01-01

    UV irradiation has been applied either to one parent prior to crossing or to newly formed zygotes. The effects of UV have been studied on the transmission of mitochondrial alleles at the loci conferring resistance to antibiotic and the frequency of recombinants between various combinations of alleles at these loci. The effects of UV depend on the nature of the cross i.e. homosexual (ω + x ω + or ω - x ω - ) or heterosexual (ω + x ω - ). In all cases UV irradiation of one of the parents diminishes the transmission of the mitochondrial alleles originated from the irradiated parent. In homosexual crosses the decrease of transmission is the same for alleles at all the loci. In heterosexual crosses, when the ω + parent is irradiated, there is a differential decrease of transmission depending on the distance of the resistance locus relative to the ω locus. In heterosexual crosses irradiation of the ω + parent increases the frequency of recombinants while irradiation of the ω - parent slightly decreases it. In homosexual crosses the frequency of recombinants diminishes when a high UV dose is applied to one of the parents. No or only minor modifications of the polarity of recombination are observed. Irradiation of newly formed zygotes has no or minor effects on the transmission of alleles and recombinant frequencies. All these effects can be interpreted in terms of a general model for recombination of mitochondrial genes. UV irradiation of one of the parents leads to a modification of the input fraction in favor of the non irradiated parent. As a consequence of this modification the output of alleles and the frequency of recombinants are changed. A good quantitative agreement between the predictions calculated on the basis of the model and the experimental data is found. Relationships between the molecular events responsible for the modifications of input and the production of rho - primary clones by UV are discussed. (orig./MG) [de

  12. Damaged DNA-binding protein 2 (DDB2 protects against UV irradiation in human cells and Drosophila

    Directory of Open Access Journals (Sweden)

    Lin Chia-Hua

    2010-04-01

    Full Text Available Abstract Background We observed previously that cisplatin-resistant HeLa cells were cross-resistant to UV light due to accumulation of DDB2, a protein implicated in DNA repair. More recently, we found that cFLIP, which represents an anti-apoptotic protein whose level is induced by DDB2, was implicated in preventing apoptosis induced by death-receptor signaling. In the present study, we investigated whether DDB2 has a protective role against UV irradiation and whether cFLIP is also involved in this process. Methods We explored the role of DDB2 in mediating UV resistance in both human cells and Drosophila. To do so, DDB2 was overexpressed by using a full-length open reading frame cDNA. Conversely, DDB2 and cFLIP were suppressed by using antisense oligonucleotides. Cell survival was measured using a colony forming assay. Apoptosis was monitored by examination of nuclear morphology, as well as by flow cytometry and Western blot analyses. A transcription reporter assay was also used to assess transcription of cFLIP. Results We first observed that the cFLIP protein was upregulated in UV-resistant HeLa cells. In addition, the cFLIP protein could be induced by stable expression of DDB2 in these cells. Notably, the anti-apoptotic effect of DDB2 against UV irradiation was largely attenuated by knockdown of cFLIP with antisense oligonucleotides in HeLa cells. Moreover, overexpression of DDB2 did not protect against UV in VA13 and XP-A cell lines which both lack cFLIP. Interestingly, ectopic expression of human DDB2 in Drosophila dramatically inhibited UV-induced fly death compared to control GFP expression. On the other hand, expression of DDB2 failed to rescue a different type of apoptosis induced by the genes Reaper or eiger. Conclusion Our results show that DDB2 protects against UV stress in a cFLIP-dependent manner. In addition, the protective role of DDB2 against UV irradiation was found to be conserved in divergent living organisms such as human and

  13. Olefin metathesis over silica-supported molybdena catalysts activated by UV-irradiation in the presence of alkanes

    International Nuclear Information System (INIS)

    Subbotina, I.R.; Shelimov, B.N.; Kazanskij, V.B.

    1997-01-01

    It is established that molybdenum-silica catalysts (MoO 3 /SiO 2 ) applied after their irradiation by UV-light in the alkanes atmosphere acquire high activity in the reaction of propylen and hexene metathesis at the temperature of 293 K. The efficiency of photoactivated catalysts during these reactions is determined. It is shown that by UV-irradiation of MoO 3 /SiO 2 in presence of alkanes there take place the Mo 6+ ions conversion to Mo 5+ and Mo 4+ , formation the of Mo 4+ solid π-complexes with olefins and, probably, the surface carbene complexes Mo=CH-R

  14. Comparison of UV irradiation and p-fluorphenylaline as selective agents for production of aromatic compounds in plant cell culture

    International Nuclear Information System (INIS)

    Quesnel, A.A.; Ellis, B.E.

    1989-01-01

    Resistance to UV irradiation, and to the toxicity of p-fluorophenylalanine, can both be mediateted in plants by enhanced synthesis of aromatic compounds. These selective agents were applied to cell cultures of Nicotiana tabacum, Anchusa officinalis and Catharanthus roseur, and the production of aromatic metabolites in the resulting resistant lines of each species was compared. While Nicotiana and Anchusa cultures responded to each selective agent ith an enhanced accumulation of aromatic compounds, the Catharanthus cultures acquired resistance through other, unknown, mechanisms. Some degree of cross-resistance was observed between cultures selected individually for resistance to each agent (author). 26 refs.; 2 figs.; 1 tab

  15. Dual UV irradiation-based metal oxide nanoparticles for enhanced antimicrobial activity in Escherichia coli and M13 bacteriophage.

    Science.gov (United States)

    Jin, Su-Eon; Hwang, Woochul; Lee, Hyo Jung; Jin, Hyo-Eon

    2017-01-01

    Metal oxide (MO) nanoparticles have been studied as nano-antibiotics due to their antimicrobial activities even in antibiotic-resistant microorganisms. We hypothesized that a hybrid system of dual UV irradiation and MO nanoparticles would have enhanced antimicrobial activities compared with UV or MO nanoparticles alone. In this study, nanoparticles of ZnO, ZnTiO 3 , MgO, and CuO were selected as model nanoparticles. A dual UV collimated beam device of UV-A and UV-C was developed depending upon the lamp divided by coating. Physicochemical properties of MO nanoparticles were determined using powder X-ray diffractometry (PXRD), Brunauer-Emmett-Teller analysis, and field emission-scanning electron microscopy with energy-dispersive X-ray spectroscopy. Atomic force microscopy with an electrostatic force microscopy mode was used to confirm the surface topology and electrostatic characteristics after dual UV irradiation. For antimicrobial activity test, MO nanoparticles under dual UV irradiation were applied to Escherichia coli and M13 bacteriophage (phage). The UV-A and UV-C showed differential intensities in the coated and uncoated areas (UV-A, coated = uncoated; UV-C, coated ≪ uncoated). MO nanoparticles showed sharp peaks in PXRD patterns, matched to pure materials. Their primary particle sizes were less than 100 nm with irregular shapes, which had an 8.6~25.6 m 2 /g of specific surface area with mesopores of 22~262 nm. The electrostatic properties of MO nanoparticles were modulated after UV irradiation. ZnO, MgO, and CuO nanoparticles, except ZnTiO 3 nanoparticles, showed antibacterial effects on E. coli . Antimicrobial effects on E. coli and phages were also enhanced after cyclic exposure of dual UV and MO nanoparticle treatment using the uncoated area, except ZnO nanoparticles. Our results demonstrate that dual UV-MO nanoparticle hybrid system has a potential for disinfection. We anticipate that it can be developed as a next-generation disinfection system in

  16. Dual UV irradiation-based metal oxide nanoparticles for enhanced antimicrobial activity in Escherichia coli and M13 bacteriophage

    Directory of Open Access Journals (Sweden)

    Jin SE

    2017-11-01

    Full Text Available Su-Eon Jin,1 Woochul Hwang,2 Hyo Jung Lee,3 Hyo-Eon Jin3 1Research Institute for Medical Sciences, College of Medicine, Inha University, Incheon, 2ECOSET Co., Ltd., Ansan, 3College of Pharmacy, Ajou University, Suwon, Korea Abstract: Metal oxide (MO nanoparticles have been studied as nano-antibiotics due to their antimicrobial activities even in antibiotic-resistant microorganisms. We hypothesized that a hybrid system of dual UV irradiation and MO nanoparticles would have enhanced antimicrobial activities compared with UV or MO nanoparticles alone. In this study, nanoparticles of ZnO, ZnTiO3, MgO, and CuO were selected as model nanoparticles. A dual UV collimated beam device of UV-A and UV-C was developed depending upon the lamp divided by coating. Physicochemical properties of MO nanoparticles were determined using powder X-ray diffractometry (PXRD, Brunauer-Emmett-Teller analysis, and field emission-scanning electron microscopy with energy-dispersive X-ray spectroscopy. Atomic force microscopy with an electrostatic force microscopy mode was used to confirm the surface topology and electrostatic characteristics after dual UV irradiation. For antimicrobial activity test, MO nanoparticles under dual UV irradiation were applied to Escherichia coli and M13 bacteriophage (phage. The UV-A and UV-C showed differential intensities in the coated and uncoated areas (UV-A, coated = uncoated; UV-C, coated << uncoated. MO nanoparticles showed sharp peaks in PXRD patterns, matched to pure materials. Their primary particle sizes were less than 100 nm with irregular shapes, which had an 8.6~25.6 m2/g of specific surface area with mesopores of 22~262 nm. The electrostatic properties of MO nanoparticles were modulated after UV irradiation. ZnO, MgO, and CuO nanoparticles, except ZnTiO3 nanoparticles, showed antibacterial effects on E. coli. Antimicrobial effects on E. coli and phages were also enhanced after cyclic exposure of dual UV and MO nanoparticle

  17. Enhanced performance of poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C61-butyric acid methyl ester solar cells by UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Wenjin; Song, Guoxin; Li, Yonghua; Yuan, Chunqiu; Fan, Tianju; Tang, Wei; Wang, Jin; Zhao, Chunyan; Lai, Wenyong [Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), School of Materials Science and Engineering, Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023 (China); Zhang, Hongmei, E-mail: iamhmzhang@njupt.edu.cn [Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), School of Materials Science and Engineering, Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023 (China); Min, Yong, E-mail: iamygmin@njupt.edu.cn [Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), School of Materials Science and Engineering, Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023 (China); Huang, Wei, E-mail: wei-huang@njtech.edu.cn [Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), School of Materials Science and Engineering, Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023 (China); Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials - SICAM, Nanjing Tech University - NanjingTech, 30 South Puzhu Road, Nanjing 211816 (China)

    2016-02-01

    This study was undertaken to investigate the effect of ultraviolet (UV) irradiation on poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C61-butyric acid methyl (P3HT:PCBM) solar cells before the thermal annealing of its active layer. Aggregation size of the active layer was observed to increase after UV irradiation, according to the transmission electron microscopy images. Characterization of X-ray diffraction and atomic force microscopy demonstrated that UV irradiation can improve the crystallinity of P3HT phase and optimize the roughness of the active layer. Simulation results indicated that UV irradiation of appropriate time can improve physics parameters of the devices. As a result, the maximum power conversion efficiency of the devices was increased from 3.5% to 4.5%. - Highlights: • High efficiency of 4.5% was achieved based on P3HT:PCBM system. • UV irradiation of 365 nm significantly influenced aggregate morphology of PCBM. • Physical parameters were calculated to evaluate the variation quantitatively.

  18. First performance results of two novel spectroradiometers developed for fast scanning of solar spectra UV irradiance

    Science.gov (United States)

    Feister, Uwe; Kaifel, Anton K.; Grewe, Rolf-Dieter; Kaptur, Jasmine; Reutter, Oliver; Wohlfart, Michael; Gericke, Klaus

    2003-11-01

    Two recently developed different types of fast spectroradiometers measuring solar UV irradiance have been compared in a field campaign: i) the UV spectroradiometer on filter model basis (UV-SPRAFIMO) and ii) the modified version of the spectroradiometer SPECTRO 320D by Instrument Systems. The all-weather UV-SPRAFIMO instrument combines a UV filter radiometer with 5 narrow-band (FBHM ~ 2.0 to 2.5 nm) filters centered within +/- 0.01 nm at 303.5, 309.0, 314.5, 327.0 and 387.0 nm, and an advanced neural network-based model. It allows up to 5 measurements per second to be taken that are averaged within time intervals between 5 and 30 s. The neural networks model that is embedded in the PC-based processing software converts the 5 measured irradiances into a full spectrum from 280 to 450 nm at small wavelength steps (>= 0.05 nm). These spectra can be convoluted with user-defined slit function and integrated to broad-band and action-spectra-weighted irradiance values. Users can access the data stored in the internal data logger by a serial RS232 interface or by a modem and display them on a PC-based Graphical User Interface. The spectroradiometer SPECTRO320D consists of a grating double monochromator with a cooled (-20°C) PMT receiver. The modified instrument version run by DWD uses a Schreder type cosine diffuser that directs the solar global irradiance via quartz fiber optics onto the spectroradiometer's entrance slit. The spectroradiometer used at the campaign was installed in a thermostatted (22 +/- 0.02)°C aluminum box. The modified instrument version performs a spectral scan over the whole UV region in two subsequent parts, with a lower speed in the UV-B than in the UV-A to account for the exponential changes of solar irradiance with increasing wavelengths in the UV-B and for the almost linear change in the UV-A region. In the configuration applied in the comparison, i.e. wavelength steps of 0.2 nm within the scan range from 290 nm to 450 nm, the resulting scan

  19. Efficacy of topically applied tocopherols and tocotrienols in protection of murine skin from oxidative damage induced by UV-irradiation.

    Science.gov (United States)

    Weber, C; Podda, M; Rallis, M; Thiele, J J; Traber, M G; Packer, L

    1997-01-01

    To assess the efficacy of various forms of vitamin E in protection of skin from UV-light-induced oxidative stress, vitamin E (tocotrienol-rich fraction of palm oil, TRF) was applied to mouse skin and the contents of antioxidants before and after exposure to UV-light were measured. Four polypropylene plastic rings (1 cm2) were glued onto the animals' backs, and 20 microliters 5% TRF in polyethylene glycol-400 (PEG) was applied to the skin circumscribed by two rings and 20 microliters PEG to the other two rings. After 2 h, the skin was washed and half of the sites were exposed to UV-irradiation (2.8 mW/cm2 for 29 mi: 3 MED). TRF treatment (n = 19 mice) increased mouse skin alpha-tocopherol 28 +/- 16-fold, alpha-tocotrienol 80 +/- 50-fold, gamma-tocopherol 130 +/- 108-fold, and gamma-tocotrienol 51 +/- 36-fold. A significantly higher percentage of alpha-tocopherol was present in the skin as compared with that in the applied TRF. After UV-irradiation, all vitamin E forms decreased significantly (p antioxidants: however, prior application of TRF to mouse skin results in preservation of vitamin E.

  20. Antioxidant activity for spice oils (1) anti oxidative stability of thyme and caraway oil extracts under UV-irradiation

    International Nuclear Information System (INIS)

    Atef Ghazy, M.; Shaker, E.S.

    2002-01-01

    The anti oxidative activity for some spice essential oils have been investigated using thiocyanate method and compared with common natural antioxidant. The antioxidant activity for nine spice oils has been measured at 500 ppm after 13 days. The most potent one was the lemon grass (99.8), followed by orange peel, thyme, and caraway. The activities for these four oils were higher than that for Alpha-tocopherol (87.7%). Petitgrain, and geranium oils have marched activity but less than that for Alpha-tocopherol. No obvious has been found for citronella. fennel, and cardamon oils. The aqueous, butanoic, methanolic and hexanoic extracts for thyme and caraway oil exhibit effective anti oxidative activities under UV irradiation (254 nm) for 6 and 10 hr compared with that for alpha-tocopherol. The anti oxidative effect of thyme and caraway oil extracts were found to be strong and stable towards UV-irradiation, and equal to that for Alpha-tocopherol. Thyme's aqueous and caraway's hexanal extracts were the most potent extracts under the same conditions

  1. A constitutive damage specific DNA-binding protein is synthesized at higher levels in UV-irradiated primate cells

    International Nuclear Information System (INIS)

    Hirschfeld, S.; Levine, A.S.; Ozato, K.; Protic, M.

    1990-01-01

    Using a DNA band shift assay, we have identified a DNA-binding protein complex in primate cells which is present constitutively and has a high affinity for UV-irradiated, double-stranded DNA. Cells pretreated with UV light, mitomycin C, or aphidicolin have higher levels of this damage-specific DNA-binding protein complex, suggesting that the signal for induction can either be damage to the DNA or interference with cellular DNA replication. Physiochemical modifications of the DNA and competition analysis with defined substrates suggest that the most probable target site for the damage-specific DNA-binding protein complex is a 6-4'-(pyrimidine-2'-one)-pyrimidine dimer: specific binding could not be detected with probes which contain -TT- cyclobutane dimers, and damage-specific DNA binding did not decrease after photoreactivation of UV-irradiated DNA. This damage-specific DNA-binding protein complex is the first such inducible protein complex identified in primate cells. Cells from patients with the sun-sensitive cancer-prone disease, xeroderma pigmentosum (group E), are lacking both the constitutive and the induced damage-specific DNA-binding activities. These findings suggest a possible role for this DNA-binding protein complex in lesion recognition and DNA repair of UV-light-induced photoproducts

  2. Removal of binary azo dyes from water by UV-irradiated degradation in TiO2 suspensions

    International Nuclear Information System (INIS)

    Juang, Ruey-Shin; Lin, Su-Hsia; Hsueh, Pei-Ying

    2010-01-01

    Photodegradation and mineralization of single and binary Acid Orange 7 (AO7) and Reactive Red 2 (RR2) under UV irradiation in TiO 2 suspensions was examined. Experiments were conducted as a function of initial pH, TiO 2 dose, and initial dye concentration. First-order derivative spectrophotometric method was used to simultaneously analyze AO7 and RR2 in binary solutions. The Langmuir-Hinshelwood kinetic model was applied to evaluate and compare the apparent rate constants for the photodegradation of both dyes in single and binary solutions. It was shown that photodegradation of both dyes in binary solution was slower than those in single solution under comparable conditions. Moreover, the difference between the apparent rate constants of RR2 and AO7 became smaller in contrast to the cases of single solutions. After 20-min UV irradiation with 0.5 g/L TiO 2 , complete removal of single 0.086 mM AO7 and 0.086 mM RR2 at pH 6.8 was obtained, but only 60% and 45% of binary 0.086 mM AO7 and 0.086 mM RR2 was removed, respectively.

  3. Protective effect of gelatin and gelatin hydrolysate from salmon skin on UV irradiation-induced photoaging of mice skin

    Science.gov (United States)

    Chen, Tiejun; Hou, Hu; Lu, Jiaohan; Zhang, Kai; Li, Bafang

    2016-08-01

    The objective of this study was to investigate the effect of gelatin (SG) isolated from salmon skin and its hydrolysate (SGH) on photoaging skin, and the mechanism responsible for anti-photoaging. The average molecular weights of SG and SGH were 65 kDa and 873 Da, respectively. The amino acid compositions of SG and SGH were similar. Both of them were abundant in hydrophobic amino acids. Twenty-five peptides were identified from SGH. SG and SGH could improve UV irradiation-induced pathological changes of macroscopical tissue texture and skin morphology. Hydroxyproline content is an indicator of matrix collagen content, SG and SGH could inhibit the decrease of hydroxyproline content in photoaging skin in a dose dependent manner. In addition, SG and SGH could alleviate UV irradiation-induced oxidative damages to skin by increasing the activities of total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), increasing the content of glutathione (GSH) and decreasing the content of malonaldehyde (MDA). Moreover, SG and SGH could enhance immune regulation system by increasing the thymus index. Thus, the anti-photoaging mechanisms of SG and SGH were by inhibiting the depletion of antioxidant defense components, involving in the synthesis of collagen and enhancing the function of immune system. Besides, SGH showed a better result in protecting skin from photoaging than SG.

  4. Effect of local UV irradiation of generative nuclei of Paramecium caudatum on sexual functions of the cells

    International Nuclear Information System (INIS)

    Skoblo, I.I.; Borkhsenius, O.N.

    1979-01-01

    The functions of micronucleus (MI) were studied in the period of the sexual process in Paramecium caudatum-infusoria the descendants of the cells, whose micronucleus was locally irradiated with UV rays at the dose of 3060 erg/mm 2 . It has been found that the descendants of the irradiated cells (the cells of UV clones) can be involved into the sexual process irrespoctive of the morphological type of their MI. Four out of forteen UV clones have changed the initial mating type for the opposite one. It is suggested that the change of the mating type is related to the changes of MI genome resulted from UV irradiation. The pathway of nuclear transformations in the course of sexual process was traced in cells of three UV clones. It has been found, that local UV irradiation of MI causes a number of deviations in the behaviour of MI derivatives in the metagamic part of the sexual process in the clones, whose MI have undergone substantial morphological changes. The exconjugants produced by crossing of UV clones with such changed MI and the normal test-clone were characterized by low viability

  5. Removal of binary azo dyes from water by UV-irradiated degradation in TiO2 suspensions.

    Science.gov (United States)

    Juang, Ruey-Shin; Lin, Su-Hsia; Hsueh, Pei-Ying

    2010-10-15

    Photodegradation and mineralization of single and binary Acid Orange 7 (AO7) and Reactive Red 2 (RR2) under UV irradiation in TiO(2) suspensions was examined. Experiments were conducted as a function of initial pH, TiO(2) dose, and initial dye concentration. First-order derivative spectrophotometric method was used to simultaneously analyze AO7 and RR2 in binary solutions. The Langmuir-Hinshelwood kinetic model was applied to evaluate and compare the apparent rate constants for the photodegradation of both dyes in single and binary solutions. It was shown that photodegradation of both dyes in binary solution was slower than those in single solution under comparable conditions. Moreover, the difference between the apparent rate constants of RR2 and AO7 became smaller in contrast to the cases of single solutions. After 20-min UV irradiation with 0.5 g/L TiO(2), complete removal of single 0.086 mM AO7 and 0.086 mM RR2 at pH 6.8 was obtained, but only 60% and 45% of binary 0.086 mM AO7 and 0.086 mM RR2 was removed, respectively. 2010 Elsevier B.V. All rights reserved.

  6. Spectral, structural, optical and dielectrical studies of UV irradiated Rose Bengal thin films prepared by spin coating technique

    Energy Technology Data Exchange (ETDEWEB)

    Zeyada, H.M., E-mail: hzeyada@gmail.com [Department of Physics, Faculty of Science at New Damietta, University of Damietta, 34517 (Egypt); Youssif, M.I.; El-Ghamaz, N.A. [Department of Physics, Faculty of Science at New Damietta, University of Damietta, 34517 (Egypt); Aboderbala, M.E.O. [Department of Physics, Faculty of Science at New Damietta, University of Damietta, 34517 (Egypt); Department of Physics, Faculty of Science, AlJabl Al Gharbi University (Libya)

    2017-02-01

    Optical properties of pristine and UV irradiated Rose Bengal (RB) films have been investigated using transmittance and reflectance methods. The refractive index(n) and extinction coefficient (k) have been calculated from the absolute values of transmission and reflection spectrum. Single oscillator parameters and Drude model of free carrier absorption have been applied for analysis of the refractive index dispersion. Within the frame work of the band-to-band electron transitions theory; the fundamental absorption edge data were analyzed. Our results suggest that thickness of RB films has no effect on the absorption or the refractive indices in the investigated thicknesses range and within the experimental error. Structural transformation of films from amorphous to polycrystalline has been observed upon UV irradiation. Accordingly, the decreases of all of the absorption coefficient, the energy gap and the refractive index of RB films have been detected. Furthermore, the dependence of the optical functions on UV exposure times has been discussed based on the spectral distribution of the dielectric constant.

  7. Effect of UV-irradiation in vitro on adenin nucleotides metabolism, Na+ and K+ concentration, osmotic properties and submicroscopic structure of pigeon red blood cells

    International Nuclear Information System (INIS)

    Kabat, I.A.; Sysa, J.; Leyko, W.; Kwiatkowski, B.; Sysa, A.; Zakrzewska, I.; Hlynczak, A.; Lodz Univ.; Akademia Medyczna, Lodz; Akademia Medyczna, Gdansk

    1975-01-01

    Effect of UV-irradiation in vitro on metabolism of adenine nucleotides: ADP, ATP and AXP, osmotic properties and submicroscopic structure of nucleated pigeon red blood cell was investigated. Irradiation was carried out for 60, 120, 180, 240 and 300 minutes. Hanau S-500 lamp with efficiency 4.34 x 10 8 erg/sec was used. A decrease of ATP content with a simultaneous increase of ADP and AXP contents and a rather constant level of the sum of adenine compounds was observed. UV-irradiation caused a decrease of reversal of hemolysis and osmotic resistance to hypotonic NaCl solutions. An equivalent exchange of Na + and K + ions and an increase of hematocrit value, following UV-irradiation was observed. Electron microscope studies demonstrated changes of ultrastructure concerning both cell nucleus and thickness and granulation of cell membrane. (orig.) [de

  8. Phototransformation of iodate by UV irradiation: Kinetics and iodinated trihalomethane formation during subsequent chlor(am)ination

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Fu-Xiang [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418 (China); Hu, Xiao-Jun, E-mail: hu-xj@mail.tsinghua.edu.cn [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418 (China); Xu, Bin; Zhang, Tian-Yang; Gao, Yu-Qiong [State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

    2017-03-15

    Highlights: • IO{sub 3}{sup −} can be photodegraded by UV irradiation with pseudo-first order kinetics. • Solution pH has no remarkable influence on the photodegradation rate of IO{sub 3}{sup −}. • The I{sup −} and HOI derived from the photoreduction of IO{sub 3}{sup −} were determined. • The presence of NOM greatly enhanced the photolysis rate of IO{sub 3}{sup −}. • NOM sources can affect the formation of I-THMs in UV-chlor(am)ination of IO{sub 3}{sup −}. - Abstract: The photodegradation of IO{sub 3}{sup −} at 254 nm and the formation of iodinated trihalomethanes (I-THMs) during subsequent chlorination or chloramination in the presence of natural organic matter (NOM) were investigated in this study. The thermodynamically stable IO{sub 3}{sup −} can be degraded by UV irradiation with pseudo-first order kinetics and the quantum yield was calculated as 0.0591 mol einstein{sup −1}. Solution pH posed no remarkable influence on the photolysis rate of IO{sub 3}{sup −}. The UV phototransformation of IO{sub 3}{sup −} was evidenced by the determination of iodide (I{sup −}) and hypoiodous acid (HOI) in solution. NOM sources not only enhanced the photodegradation rate of IO{sub 3}{sup −} by photoejecting solvated electrons, but also greatly influenced the production I-THMs in subsequent chlor(am)ination processes. In UV irradiation and sequential oxidation processes by chlorine or chloramine, the I-THMs formation was susceptible to NOM sources, especially the two major fractions of aqueous humic substances (humic acid and fulvic acid). The toxicity of disinfected waters greatly increased in chloramination over chlorination of the UV photodecomposed IO{sub 3}{sup −}, as far more I-THMs especially CHI{sub 3}, were formed. As “the fourth iodine source” of iodinated disinfection by-products, the occurrence, transportation and fate of IO{sub 3}{sup −} in aquatic environment should be of concern instead of being considered a desired

  9. High Refractive Organic–Inorganic Hybrid Films Prepared by Low Water Sol-Gel and UV-Irradiation Processes

    Directory of Open Access Journals (Sweden)

    Hsiao-Yuan Ma

    2016-03-01

    Full Text Available Organic-inorganic hybrid sols (Ti–O–Si precursor were first synthesized by the sol-gel method at low addition of water, and were then employed to prepare a highly refractive hybrid optical film. This film was obtained by blending the Ti–O–Si precursor with 2-phenylphenoxyethyl acrylate (OPPEA to perform photo-polymerization by ultraviolet (UV irradiation. Results show that the film transparency of poly(Ti–O–Si precursor-co-OPPEA film is higher than that of a pure poly(Ti–O–Si precursor film, and that this poly(Ti–O–Si precursor-co-OPPEA hybrid film exhibits a high transparency of ~93.7% coupled with a high refractive index (n of 1.83 corresponding to a thickness of 2.59 μm.

  10. Photocatalytic antibacterial effects are maintained on resin-based TiO2 nanocomposites after cessation of UV irradiation.

    Science.gov (United States)

    Cai, Yanling; Strømme, Maria; Welch, Ken

    2013-01-01

    Photocatalysis induced by TiO2 and UV light constitutes a decontamination and antibacterial strategy utilized in many applications including self-cleaning environmental surfaces, water and air treatment. The present work reveals that antibacterial effects induced by photocatalysis can be maintained even after the cessation of UV irradiation. We show that resin-based composites containing 20% TiO2 nanoparticles continue to provide a pronounced antibacterial effect against the pathogens Escherichia coli, Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus mutans and Enterococcus faecalis for up to two hours post UV. For biomaterials or implant coatings, where direct UV illumination is not feasible, a prolonged antibacterial effect after the cessation of the illumination would offer new unexplored treatment possibilities.

  11. Modification of immunological potential by ultraviolet radiation. I. Immune status of short-term uv-irradiated mice

    International Nuclear Information System (INIS)

    Spellman, C.W.; Woodward, J.G.; Daynes, R.A.

    1977-01-01

    C3Hf/HeN mice support the progressive growth of most transplanted syngeneic ultraviolet (uv) light-induced tumors following short-term uv exposure whereas nonexposed mice reject these tumors. Because an immunosuppressive role in uv-mediated tumor susceptibility might be suggested by these observations, a comparison of several immunological parameters has been conducted. These include antibody production, proliferation in response to antigenic and mitogenic stimulation, and the generation of cytotoxic effector cells by normal or short-term uv-exposed mice. The results indicate that short-term uv irradiation of mice does not result in any readily detectable alterations of the host's immune system other than the consistent loss of the antitumor response mediating rejection of the transplanted uv-induced tumor

  12. The effect of UV irradiation on the refractive index modulation in photo-thermo-refractive glasses: Mechanisms and application

    Science.gov (United States)

    Chernakov, Dmitry I.; Sidorov, Alexander I.; Stolyarchuk, Maxim V.; Kozlova, Darya A.; Krykova, Victoria A.; Nikonorov, Nikolay V.

    2018-02-01

    It is shown experimentally that in photo-thermo-refractive glasses the transformation of charged silver subnanosized molecular clusters to neutral state by UV irradiation results in the increase of glass refractive index. The increment of the refractive index reaches Δn = 0.76·10-4. Computer simulation has shown that the polarizability of neutral molecular clusters is by 20-40% larger than of charged ones. The reason of this is the increase of electron density and volume of electron density surfaces during the transformation of molecular cluster to the neutral state. The transition molecular cluster from the ground state to the excited state also results in the increase of its polarizability.

  13. Photocatalytic antibacterial effects are maintained on resin-based TiO2 nanocomposites after cessation of UV irradiation.

    Directory of Open Access Journals (Sweden)

    Yanling Cai

    Full Text Available Photocatalysis induced by TiO2 and UV light constitutes a decontamination and antibacterial strategy utilized in many applications including self-cleaning environmental surfaces, water and air treatment. The present work reveals that antibacterial effects induced by photocatalysis can be maintained even after the cessation of UV irradiation. We show that resin-based composites containing 20% TiO2 nanoparticles continue to provide a pronounced antibacterial effect against the pathogens Escherichia coli, Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus mutans and Enterococcus faecalis for up to two hours post UV. For biomaterials or implant coatings, where direct UV illumination is not feasible, a prolonged antibacterial effect after the cessation of the illumination would offer new unexplored treatment possibilities.

  14. TiO2/Pt/TiO2 Sandwich Nanostructures: Towards Alcohol Sensing and UV Irradiation-Assisted Recovery

    Directory of Open Access Journals (Sweden)

    Rungroj Maolanon

    2017-01-01

    Full Text Available The TiO2/Pt/TiO2 sandwich nanostructures were synthesized by RF magnetron sputtering and demonstrated as an alcohol sensor at room-temperature operation with a fast recovery by UV irradiation. The TiO2/Pt/TiO2 layers on SiO2/Si substrate were confirmed by Auger electron spectroscopy with the interdiffusion of each layer. The TiO2/Pt/TiO2 layers on printed circuit board show the superior sensor response to alcohol in terms of the sensitivity and stability compared to the nonsandwich structure, that is, the only Pt layer or the TiO2/Pt structures. Moreover, the recovery time of the TiO2/Pt/TiO2 was improved by UV irradiation-assisted recovery. The optimum TiO2/Pt/TiO2 with thicknesses of the undermost TiO2 layer, a Pt layer, and the topmost TiO2 layer being 50 nm, 6 nm, and 5 nm, respectively, showed the highest response to ethanol down to 10 ppm. Additionally, TiO2/Pt/TiO2 shows an excellent sensing stability and exhibits different sensing selectivity among ethanol, methanol, and 2-propanol. The sensing mechanism could be attributed to the change of Pt work function during vapor adsorption. The TiO2 layer plays an important role in UV-assisted recovery by photocatalytic activity and the topmost TiO2 acts as protective layer for Pt.

  15. Comparative investigations of the effects of X- and UV-irradiation on lysozyme in the absence or presence of additives

    International Nuclear Information System (INIS)

    Durchschlag, H.; Hefferle, T.; Zipper, P.

    2002-01-01

    Complete text of publication follows. The radiation damage (X-ray, UV light) of many proteins and other biomolecules has been investigated by various physicochemical techniques. They revealed numerous changes of the local and global structure of the proteins studied, together with alterations of their functional ability. For the comparison of radiation-induced effects, lysozyme was chosen in a case study, because this enzyme is well characterized, both from the radiobiological and physicochemical point of view. Since the 3D structure and many other details of this protein are known, it may also be used for modeling approaches, including visualization of the individual constituents (amino acid residues, surrounding water molecules). Despite many problems and ambiguities concerning an exact comparison of the impact of ionizing and nonionizing radiation, the resultant radiation effects may be correlated quantitatively. A critical analysis of the radiation damages obtained allows determination of 'isoeffective' doses. The doses, which have been derived from activity measurements (e.g., 1 kGy and 30 kJ/m 2 in the case of lysozyme), may also be applied successfully for comparing the structural changes occurring after preceding irradiation. A comparison of the radiation effects monitored in the absence of additives reveals that the damages observed after X- and UV-irradiation (inactivation, aggregation, fragmentation, destruction of aromatics and SS bonds, formation of crosslinks and new chromophores, partial unfolding etc.) are similar but differ with respect to the type of irradiation and the conditions applied. Addition of many compounds discloses a quite different behavior of the compounds tested as protectives against X- or UV-irradiation. Some substances may provide a chemical repair of already damaged particles, restoring some of the original molecular features

  16. Rapid and apparently error-prone excision repair of nonreplicating UV-irradiated plasmids in Xenopus laevis oocytes

    Energy Technology Data Exchange (ETDEWEB)

    Hays, J.B.; Ackerman, E.J.; Pang, Q.S. (Oregon State Univ., Corvallis (USA))

    1990-07-01

    Repair of UV-irradiated plasmid DNA microinjected into frog oocytes was measured by two techniques: transformation of repair-deficient (delta uvrB delta recA delta phr) bacteria, and removal of UV endonuclease-sensitive sites (ESS). Transformation efficiencies relative to unirradiated plasmids were used to estimate the number of lethal lesions; the latter were assumed to be Poisson distributed. These estimates were in good agreement with measurements of ESS. By both criteria, plasmid DNA was efficiently repaired, mostly during the first 2 h, when as many as 2 x 10(10) lethal lesions were removed per oocyte. This rate is about 10(6) times the average for removal of ESS from repair-proficient human cells. Repair was slower but still significant after 2 h, but some lethal lesions usually remained after overnight incubation. Most repair occurred in the absence of light, in marked contrast to differentiated frog cells, previously shown to possess photoreactivating but no excision repair activity. There was no increase in the resistance to DpnI restriction of plasmids (methylated in Escherichia coli at GATC sites) incubated in oocytes; this implies no increase in hemimethylated GATC sites, and hence no semiconservative DNA replication. Plasmid substrates capable of either intramolecular or intermolecular homologous recombination were not recombined, whether UV-irradiated or not. Repair of Lac+ plasmids was accompanied by a significant UV-dependent increase in the frequency of Lac- mutants, corresponding to a repair synthesis error frequency on the order of 10(-4) per nucleotide.

  17. Evaluation of carotenoids and reactive oxygen species in human skin after UV irradiation: a critical comparison between in vivo and ex vivo investigations.

    Science.gov (United States)

    Meinke, Martina C; Müller, Robert; Bechtel, Anne; Haag, Stefan F; Darvin, Maxim E; Lohan, Silke B; Ismaeel, Fakher; Lademann, Jürgen

    2015-03-01

    UV irradiation is one of the most harmful exogenous factors for the human skin. In addition to the development of erythema, free radicals, that is reactive oxygen species (ROS), are induced under its influence and promote the development of oxidative stress in the skin. Several techniques are available for determining the effect of UV irradiation. Resonance Raman spectroscopy (RRS) measures the reduction of the carotenoid concentration, while electron paramagnetic resonance (EPR) spectroscopy enables the analysis of the production of free radicals. Depending on the method, the skin parameters are analysed in vivo or ex vivo. This study provides a critical comparison between in vivo and ex vivo investigations on the ROS formation and carotenoid depletion caused by UV irradiation in human skin. The oxygen content of tissue was also determined. It was shown that the antioxidant status measured in the skin samples in vivo and ex vivo was different. The depletion in the carotenoid concentration in vivo exceeded the value determined ex vivo by a factor of about 1.5, and the radical formation after UV irradiation was significantly greater in vivo by a factor of 3.5 than that measured in excised human skin, which can be explained by the lack of oxygen ex vivo. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Heat-enhanced reactivation of UV-irradiated adenovirus 2 is not associated with enhanced mutagenesis in HeLa cells

    Energy Technology Data Exchange (ETDEWEB)

    Piperakis, S.M.; McLennan, A.G. (Liverpool Univ. (UK). Dept. of Biochemistry)

    1984-04-01

    The reversion frequency of an adenovirus 2 temperature-sensitive growth mutant irradiated with different doses of UV light was determined after infection of control, UV-irradiated and heat-shocked HeLa cells. No enhancement of mutagenesis by treatment of the cells was observed. Heat-enhanced viral reactivation does not therefore display a significant error-prone component.

  19. Heat-enhanced reactivation of UV-irradiated adenovirus 2 is not associated with enhanced mutagenesis in HeLa cells.

    Science.gov (United States)

    Piperakis, S M; McLennan, A G

    1984-04-01

    The reversion frequency of an adenovirus 2 temperature-sensitive growth mutant irradiated with different doses of UV light was determined after infection of control, UV-irradiated and heat-shocked HeLa cells. No enhancement of mutagenesis by treatment of the cells was observed. Heat-enhanced viral reactivation does not therefore display a significant error-prone component.

  20. Defect creation under UV irradiation of CsI:Pb crystals in Pb 2+ -induced absorption bands investigated by luminescence methods

    Czech Academy of Sciences Publication Activity Database

    Babin, V.; Kalder, K.; Krasnikov, A.; Nikl, Martin; Nitsch, Karel; Zazubovich, S.

    2002-01-01

    Roč. 234, č. 2 (2002), s. 689-700 ISSN 0370-1972 Grant - others:NATO(XX) SfP 973510 Institutional research plan: CEZ:AV0Z1010914 Keywords : CsI:Pb crystal * luminescence * thermoluminescence * defect creation * UV irradiation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.930, year: 2002

  1. Short- and long-term variability of spectral solar UV irradiance at Thessaloniki, Greece: effects of changes in aerosols, total ozone and clouds

    Directory of Open Access Journals (Sweden)

    I. Fountoulakis

    2016-03-01

    Full Text Available In this study, we discuss the short- and the long-term variability of spectral UV irradiance at Thessaloniki, Greece, using a long, quality-controlled data set from two Brewer spectrophotometers. Long-term changes in spectral UV irradiance at 307.5, 324 and 350 nm for the period 1994–2014 are presented for different solar zenith angles and discussed in association with changes in total ozone column (TOC, aerosol optical depth (AOD and cloudiness observed in the same period. Positive changes in annual mean anomalies of UV irradiance, ranging from 2 to 6 % per decade, have been detected both for clear- and all-sky conditions. The changes are generally greater for larger solar zenith angles and for shorter wavelengths. For clear-skies, these changes are, in most cases, statistically significant at the 95 % confidence limit. Decreases in the aerosol load and weakening of the attenuation by clouds lead to increases in UV irradiance in the summer, of 7–9 % per decade for 64° solar zenith angle. The increasing TOC in winter counteracts the effect of decreasing AOD for this particular season, leading to small, statistically insignificant, negative long-term changes in irradiance at 307.5 nm. Annual mean UV irradiance levels are increasing from 1994 to 2006 and remain relatively stable thereafter, possibly due to the combined changes in the amount and optical properties of aerosols. However, no statistically significant corresponding turning point has been detected in the long-term changes of AOD. The absence of signatures of changes in AOD in the short-term variability of irradiance in the UV-A may have been caused by changes in the single scattering albedo of aerosols, which may counteract the effects of changes in AOD on irradiance. The anti-correlation between the year-to-year variability of the irradiance at 307.5 nm and TOC is clear and becomes clearer as the AOD decreases.

  2. Disinfectant effects of Purit ® , Z-Germicide ® and Carcil ® on ...

    African Journals Online (AJOL)

    The two commonly used disinfectants were Purit® (chlorhexidine gluconate Bp 0.3 % w/v and cetrimide Bp 3.0 % w/v) and Z-germicide® (7 % tar acid phenol and 2 % cresol). The new one was Carcil® (Alkyl-benzyl-dimethyl ammonium chloride). It was observed that Purit® was most effective against E.coli since it required ...

  3. 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

  4. 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.

  5. Accidental exposure to UV radiation produced by germicidal lamp: case report and risk assessment.

    Science.gov (United States)

    Zaffina, Salvatore; Camisa, Vincenzo; Lembo, Marco; Vinci, Maria Rosaria; Tucci, Mario Graziano; Borra, Massimo; Napolitano, Antonio; Cannatà, Vittorio

    2012-01-01

    Ultraviolet radiation is known to cause both benefits and harmful effects on humans. The adverse effects mainly involve two target organs, skin and eye, and can be further divided into short- and long-term effects. The present case report describes an accidental exposure of two health-care workers to ultraviolet radiation produced by a germicidal lamp in a hospital pharmacy. The germicidal lamp presented a spectrum with an intense UV-C component as well as a modest UV-B contribution. Overexposure to UV-C radiation was over 100 times as large as the ICNIRP exposure limits. A few hours after the exposure, the two subjects reported symptoms of acute UV injury and both of them continued having significant clinical signs for over 2 years. In this study, we describe acute and potentially irreversible effects caused by high UV exposure. In addition, we present the results of risk assessment by occupational exposure to germicidal lamps. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

  6. Survival and mutagenesis in UV-irradiated phage: Multi-hit kinetics of mutation induction and lack of indirect induction by infection with UV-irradiated phage of error-prone repair

    International Nuclear Information System (INIS)

    Krauss, G.; Mennigmann, H.D.; Kaplan, R.W.

    1980-01-01

    The paper is concerned with the question of whether Weigle-reactivation (WR) and Weigle-mutagenesis (WM) can be indirectly induced by infection with UV-irradiated phage. Experiments neither with phage lambda of Escherichia coli nor with phage kappa of Serratia marcescens show such induction. In this respect phage DNA differs from F'-DNA or Hfr-DNA; possible explanations are discussed. In both systems clear plaque mutations can also be induced by UV without irradiation of the host cells; they appear, in unirradiated and irradiated host cells, with an increase in frequency which is greater than proportional to the UV dose. It is concluded that mutation induction of phage in the unirradiated host cells is due to a low level constitutive mutagenic repair; this could either be due to 'spontaneous' induction of the mutagenic SOS function or it could be a mechanism different from this one. Host irradiation would give rise to additional activity by the induced SOS function leading to WR and WM. It is further concluded that deviation of the induction kinetics from a linear dose-dependence is not due to the necessary induction of SOS functions. (author)

  7. Comparison of the Organic Composition of Cometary Samples with Residues Formed from the UV Irradiation of Astrophysical Ice Analogs

    Science.gov (United States)

    Milam, S. N.; Nuevo, M.; Sandford, S. A.; Cody, G. D.; Kilcoyne, A. L. D.; Stroud, R. M.; DeGregorio, B. T.

    2010-01-01

    The NASA Stardust mission successfully collected material from Comet 81P/Wild 2 [1], including authentic cometary grains [2]. X-ray absorption near-edge structure (XANES) spectroscopy analysis of these samples indicates the presence of oxygen-rich and nitrogen-rich organic materials, which contain a broad variety of functional groups (carbonyls, C=C bonds, aliphatic chains, amines, arnides, etc.) [3]. One component of these organics appears to contain very little aromatic carbon and bears some similarity to the organic residues produced by the irradiation of ices of interstellar/cometary composition, Stardust samples were also recently shown to contain glycine, the smallest biological amino acid [4]. Organic residues produced froth the UV irradiation of astrophysical ice analogs are already known to contain a large suite of organic molecules including amino acids [5-7], amphiphilic compounds (fatty acids) [8], and other complex species. This work presents a comparison between XANES spectra measured from organic residues formed in the laboratory with similar data of cometary samples collected by the Stardust mission

  8. Efficacy of UV-irradiated larval vaccine of Ancylostoma ceylanicum (Looss, 1911) in golden hamsters (Merocricetus auratus)

    International Nuclear Information System (INIS)

    Menon, S.; Bhopale, M.K.

    1985-01-01

    A vaccination trial in golden hamsters with UV-irradiated infective larvae of Ancylostoma ceylanicum was attempted. One oral vaccination of hamsters with 100 infective larvae irradiated by means of UV-tube (390 nm) at different time intervals induced the development of resistance. As the time exposure of irradiation was increased, there was a corresponding decrease in the subsequent worm establishment. A high level of protection afforded by larvae irradiated for 15 min UV-exposure was recorded giving 99.0% and 95.0% worm reduction against the challenge doses of 100 and 1000 normal larvae respectively. There was no marked difference in worm establishment in hamsters vaccinated either orally or subcutaneously, followed by oral challenge. In the vaccinated hamsters, the manifestations of resistance at 15 min UV-exposure were shown by marked reduction in worm establishment and highly reduced epg in pellets with significantly higher blood haemoglobin levels compared with those given normal larvae as vaccine and challenge controls. (author)

  9. Impact of Age and Insulin-Like Growth Factor-1 on DNA Damage Responses in UV-Irradiated Human Skin

    Directory of Open Access Journals (Sweden)

    Michael G. Kemp

    2017-02-01

    Full Text Available The growing incidence of non-melanoma skin cancer (NMSC necessitates a thorough understanding of its primary risk factors, which include exposure to ultraviolet (UV wavelengths of sunlight and age. Whereas UV radiation (UVR has long been known to generate photoproducts in genomic DNA that promote genetic mutations that drive skin carcinogenesis, the mechanism by which age contributes to disease pathogenesis is less understood and has not been sufficiently studied. In this review, we highlight studies that have considered age as a variable in examining DNA damage responses in UV-irradiated skin and then discuss emerging evidence that the reduced production of insulin-like growth factor-1 (IGF-1 by senescent fibroblasts in the dermis of geriatric skin creates an environment that negatively impacts how epidermal keratinocytes respond to UVR-induced DNA damage. In particular, recent data suggest that two principle components of the cellular response to DNA damage, including nucleotide excision repair and DNA damage checkpoint signaling, are both partially defective in keratinocytes with inactive IGF-1 receptors. Overcoming these tumor-promoting conditions in aged skin may therefore provide a way to lower aging-associated skin cancer risk, and thus we will consider how dermal wounding and related clinical interventions may work to rejuvenate the skin, re-activate IGF-1 signaling, and prevent the initiation of NMSC.

  10. Effects of chlorpromazine with and without UV irradiation on gene expression of HepG2 cells

    International Nuclear Information System (INIS)

    Froetschl, Roland; Weickardt, Sandra; Staszewski, Solveig; Kaufmann, Gabriele; Kasper, Peter

    2005-01-01

    Damage to DNA can trigger a variety of stress-related signals that alter the expression of genes associated with numerous biological pathways. In this study, we have used a cDNA microarray representing 1089 genes related to DNA damage and repair, cell cycle, transcription, metabolism and other toxicologically important cell functions to identify genes regulated in response to DNA damage in HepG2 cells induced by UV-activated chlorpromazine (CPZ). CPZ itself is not genotoxic but, upon UV irradiation with a non-genotoxic dose in the UVA range, it produces reactive free radical intermediates with DNA damaging properties. Genotoxicity in HepG2 cells was assessed concomitantly to gene expression profiling using the Comet assay. Kinetic studies were performed at a non-cytotoxic but clearly photogenotoxic concentration of CPZ (1.25 μg/ml) to characterize gene expression profiles at four different time points (3, 7, 15, 23 h) post short-term treatment. The results obtained from repeated experiments display a time-dependent expression pattern of up-regulated and repressed genes with distinct peaks in the number of differentially expressed genes at the 7 and 23 h time points. Most of the genes with altered expression belonged to the functional categories of cell cycle regulation and cell proliferation. A comparison with published expression profiles established in response to other genotoxic compounds showed low levels of concordance, which is most likely caused by the fact that extremely different testing conditions were used

  11. CNT-embedded hollow TiO{sub 2} nanofibers with high adsorption and photocatalytic activity under UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jin-Young; Lee, Dayoung; Lee, Young-Seak, E-mail: youngslee@cnu.ac.kr

    2015-02-15

    Highlights: • CNT-embedded hollow TiO{sub 2} nanofibers were successfully fabricated via electrospinning, impregnation, and calcination. • The highest degradation ratio achieved using the CNT-embedded hollow TiO{sub 2} nanofibers. • Incorporation of embedded CNTs both increased the adsorption capability and enhanced the photodegradation activity. - Abstract: Hollow TiO{sub 2} nanofibers with embedded carbon nanotubes (CNTs) were prepared for use as photocatalysts through electrospinning, impregnation, and calcination using multiwalled CNTs (MWCNTs) with various ratios of titanium tetraisopropoxide (TTIP), and further characterized by SEM, TGA, BET and XRD. The results demonstrated the successful fabrication of hollow TiO{sub 2} nanofibers with embedded CNTs. The CNT-embedded hollow TiO{sub 2} nanofibers prepared in this study exhibited improved photocatalytic activity compared to plain hollow TiO{sub 2} nanofibers based on the conversion of methylene blue (MB) in aqueous solution under UV irradiation. The highest degradation ratio produced by the CNT-embedded hollow TiO{sub 2} nanofibers was approximately 62% after 70 min, which represented an increase of more than 80% over that of TiO{sub 2}. It was found that the enhanced efficiency of MB removal could be attributed not only to the adsorption capability of the CNTs but also to electron transfer between the CNTs and the TiO{sub 2}.

  12. A rapid approach to prepare poly(2-methyl-2-oxazoline)-based antifouling coating by UV irradiation

    Science.gov (United States)

    Zhu, Haikun; Mumtaz, Fatima; Zhang, Chong; Tan, Lin; Liu, Songtao; Zhang, Yalin; Pan, Chao; Wang, Yanmei

    2017-12-01

    A series of brush copolymers, poly[(2-methyl-2-oxazoline)-random-4-vinylpyridine] (PMOXA-r-4VP), with a variety of compositions was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization of the poly(2-methyl-2-oxazoline) methacrylate macromonomer (PMOXA-MA) and 4-vinylpyridine (4VP), and then characterized by 1H NMR spectroscopy and gel permeation chromatography (GPC). The PMOXA-based coatings on the surfaces of glass, silicon, gold and polydimethylsiloxane (PDMS) substrates were then produced by short-time ultraviolet (UV) irradiation of PMOXA-r-4VP. Water contact angel (WCA), ellipsometry, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and ζ-potential techniques were used to characterize the coatings. The results showed that copolymers can be successfully bonded on the surfaces of glass, silicon, gold, and PDMS substrate. Besides, the PMOXA-based coatings displayed a superior resistance to bovine serum albumin, human blood platelets, Human Umbilical Vein Endothelial Cells adsorption and good biocompatibility. Finally, stability test indicated that the stability of coatings can be improved with the content of the 4VP segment. Furthermore, PMOXA-r1/2-4VP immobilized surfaces displayed good antifouling property in long-term applications.

  13. Influence of Heat Treatment and UV Irradiation on the Wettability of Ti35Nb10Ta Nanotubes

    Directory of Open Access Journals (Sweden)

    Joan Lario

    2018-01-01

    Full Text Available The implant osseointegration rate depends on the surface’s topography and chemical composition. There is a growing interest in the anodic oxidation process to obtain an oxide layer with a nanotube morphology on beta titanium alloys. This surface treatment presents large surface area, nanoscale rugosity and electrochemical properties that may increase the biocompatibility and osseointegration rate in titanium implants. In this work, an anodic oxidation process was used to modify the surface on the Ti35Nb10Ta alloy to obtain a titanium nanotubes topography. The work focused on analyzing the influence of some variables (voltage, heat treatment and ultraviolet irradiation on the wettability performance of a titanium alloy. The morphology of the nanotubes surfaces was studied by Field Emission Scanning Electron Microscopy (FESEM, and surface composition was analyzed by Energy Dispersive Spectroscopy (EDS. The measurement of contact angle for the TiO2 nanotube surfaces was measured by a video contact angle system. The surface with the non photoinduced nanotubes presented the largest contact angles. The post-heat treatment lowered the F/Ti ratio in the nanotubes and decreased the contact angle. Ultraviolet (UV irradiation of the TiO2 nanotubes decrease the water contact angle.

  14. Role of the viral and cellular encoded thymidine kinase in the repair of UV-irradiated herpes simplex virus

    International Nuclear Information System (INIS)

    Rainbow, A.J.; McMaster Univ., Hamilton, ON

    1989-01-01

    A strain of herpes simplex type 1 (HSV-1:KOS) encoding a functional thymidine kinase (tk + ) gene and a thymidine kinase deficient (tk - ) mutant strain (HSC-1:PTK3B) were used as probes to examine the repair of UV-damaged viral DNA in one tk - (143) and two tk + (R970-5 and AC4) human cell lines. UV survival for each HSC-1 strain was similar for infection of both tk - and tk + cells suggesting that the repair of viral DNA was not dependent on the expression of a functional cellular tk gene. In contrast, UV survival of HSV-1:PTK3B was substantially reduced compared to HSV-1:KOS when infecting all 3 human cell lines, as well as Vero monkey kidney cells and LPM1A mouse cells. Tjese results suggest that the repair of UV-irradiated HSV-1 in lytically infected mammalian cells depends, in part at least, on the expression of the viral encoded tk. (author). 20 refs.; 1 fig

  15. Impact of Temperature and UV Irradiation on Dynamics of NO₂ Sensors Based on ZnO Nanostructures.

    Science.gov (United States)

    Procek, Marcin; Stolarczyk, Agnieszka; Pustelny, Tadeusz

    2017-10-11

    The main object of this study is the improvement of the dynamics of NO₂ sensors based on ZnO nanostructures. Investigations presented in this paper showed that the combination of temperature and ultraviolet (UV) activation of the sensors can significantly decrease the sensor response and regeneration times. In comparison with the single activation method (elevated temperature or UV), these times for 1 ppm of NO₂ decreased from about 10 min (or more) to less than 40 s. In addition, at the optimal conditions (200 °C and UV), sensors were very stable, were fully scalable (in the range on NO₂ concentration of 1-20 ppm) and baseline drift was significantly reduced. Furthermore, in this paper, extensive studies of the influence of temperature and carrier gas (nitrogen and air) on NO₂ sensing properties of the ZnO nanostructures were conducted. The NO₂ sensing mechanisms of the sensors operating at elevated temperatures and under UV irradiation were also discussed. Our study showed that sensor responses to NO₂ and response/regeneration times are comparable from sensor to sensor in air and nitrogen conditions, which suggests that the proposed simple technology connected with well-chosen operation conditions is repeatable. The estimated limit of detection of the sensors is within the level of ≈800 ppb in nitrogen and ≈700 ppb in air.

  16. Control of mitosis in Physarum polycephalum. The effect of lowering the DNA: mass ratio by uv irradiation

    International Nuclear Information System (INIS)

    Sudbery, P.E.; Grant, W.D.

    1975-01-01

    A model for the control of mitosis is presented and, along with four other models described previously, is tested by the response of Physarum polycephalum to uv irradiation. Plasmodia were irradiated following the second mitosis (M II) after fusion of microplasmodia. As shown by other authors, the onset of the next mitosis (M III) was delayed but the period M III-M IV was shortened relative to control plasmodia. It is shown that the period M III-M IV cannot be shortened beyond a minimum of 6 h despite increasing doses of uv. This minimum length is shown to be relatively independent of growth rate. If conditions were such that the length of M III-M IV was shortened to this minimum value the length of M IV-M V was also shorter than the corresponding control period. If the period M II-M IV was longer than the minimum following irradiation then the length of M IV-M V was not shortened. It is argued that only the latter situation allows models to be tested and it is shown how the observed result is consistent with only two of the five models considered. A further test compared the length of M III-M IV under these conditions with that predicted from the amount of DNA destroyed by the uv. This result was consistent only with the same two models

  17. Photoreactivation of pyrimidine dimers generated by a photosensitized reaction in RNA of the Smittia sp. embryos after UV-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kal' thoff, K.; Iekle, G. (Texas Univ., Austin (USA). Dept. of Zoology)

    1981-12-01

    Mechanisms of biological effects resulting from the irradiation of Smittia sp. embryos in an early stage of development with UV rays with the wave-length of 265, 285 and 295 nm are investigated. It is shown that the cessation of development, deceleration of protein synthesis and emergence of additional abdomens after the irradiation of embryos in early stages of development are not connected with the damage of the nucleus but with the formation of pyrimidine dimers in RNA in the cortical layer of ovum cytoplasm. At first, the energy of UV rays with the given wave-lengths is accepted in the cell by molecules-photosensitizers. It is shown for the first time that pyrimidine dimers generated in RNA can be photoreactivated on exposure of cells to light. Maternal RNA accumulated during oogenesis play an important role in the early embryogeny of insects and other animals ova developing in the sunlight. Therefore, the protection of embryo RNA from solar UV irradiation damage is provided for by the mechanisms of RNA pyrimidine dimers photoreactivation resulted from the sunlight long waves.

  18. UV Irradiation and Pleiotropic Effects of Vitamin D in Chronic Kidney Disease - Benefits on Cardiovascular Comorbidities and Quality of Life.

    Science.gov (United States)

    Krause, Rolfdieter; Stange, Rainer; Kaase, Heinrich; Holick, Michael F

    2016-03-01

    Vitamin D3 can be metabolized in the skin to 25(OH)D and 1,25(OH)2D because the skin expresses vitamin D-25-hydroxylase, 25(OH)D-1-alpha-hydroxylase, and the vitamin D receptor. The aim of this review was to discuss the pleiotropic effects after serial suberythemal UVB irradiation with a sun-simulating UV spectrum in end-stage kidney disease patients. Fourteen hemodialysis patients, with a mean age of 51 (range 41-57) years, were whole-body UV irradiated over 6 months. Patients demonstrated an increase in their hematocrit and required less erythropoietin. An increase in maximal oxygen uptake and workload capacity was associated with decreased lactic acid production. The patients demonstrated a decreased heart rate and systolic and diastolic blood pressure with an increase in the R-R-interval and the beat-to-beat-differences. Cardiovascular disease is the most important comorbidity. Exposure to simulated sunlight that contains both UVB and UVA reduce cardiovascular risk factors and improve quality of life. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  19. Naphthalene degradation in seawater by UV irradiation: The effects of fluence rate, salinity, temperature and initial concentration

    International Nuclear Information System (INIS)

    Jing, Liang; Chen, Bing; Zhang, Baiyu; Zheng, Jisi; Liu, Bo

    2014-01-01

    Highlights: • The removal of naphthalene follows first order kinetics in seawater. • Irradiance and temperature are the most influential factors. • An increase in irradiance can linearly promote photodegradation. • High salinity suppresses the photodegradation of naphthalene. - Abstract: A large amount of oil pollution at sea is produced by the operational discharge of oily wastewater. The removal of polycyclic aromatic hydrocarbons (PAHs) from such sources using UV irradiation has become attractive, yet the photolysis mechanism in seawater has remained unclear. This study examines the photodegradation kinetics of naphthalene in natural seawater through a full factorial design of experiments (DOE). The effects of fluence rate, salinity, temperature and initial concentration are investigated. Results show that fluence rate, temperature and the interaction between temperature and initial concentration are the most influential factors. An increase in fluence rate can linearly promote the photodegradation process. Salinity increasingly impedes the removal of naphthalene because of the existence of free-radical scavengers and photon competitors. The results will help understand the photolysis mechanism of PAHs and develop more effective methods for treating oily seawater generated from offshore industries

  20. Cytoprotective effect of the enzyme-mediated polygallic acid on fibroblast cells under exposure of UV-irradiation.

    Science.gov (United States)

    Sánchez-Sánchez, Roberto; Romero-Montero, Alejandra; Montiel, Carmina; Melgarejo-Ramírez, Yaaziel; Sánchez-Ortega, Carmina; Lugo-Martínez, Haydée; Cabello-Arista, Beatriz; García-Arrazola, Roeb; Velasquillo, Cristina; Gimeno, Miquel

    2017-07-01

    The poly(gallic acid), produced by laccase-mediated oxidation of gallic acid in aqueous media (pH5.5) to attain a novel material with well-defined molecular structure and high water solubility (500mg/mL at 25°C), has been investigated to understand its potential biological activities. In this regard, a biomedical approach based on cytoprotective effect on human fibroblast cells exposed to UV-irradiation in the presence of the polymer has been demonstrated. The results also shows that 200μg/mL of poly(gallic acid) inhibits the growth and migration of dermal fibroblasts and cancer cell lines without affecting cell viability. Poly(gallic acid) pretreatment with 10μg/mL protects dermal fibroblasts from UV induced cell death and additionally, the cytoprotective effect reduce ROS presence in the cells. This property can be correlated with the antioxidant power (IC 50 of 23.5μg/mL) of this novel material, which was ascertained by electronic paramagnetic resonance spectroscopy and spectrophotometrically. Additionally, the antimicrobial activity of this material was corroborated with the inhibition of Staphylococcus aureus (ATCC 25923) and Enterococcus faecalis (ATCC 29212) strains (MIC=400mg/mL) common bacteria found in hospitals. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Formation of environmentally persistent free radicals as the mechanism for reduced catechol degradation on hematite-silica surface under UV irradiation.

    Science.gov (United States)

    Li, Hao; Pan, Bo; Liao, Shaohua; Zhang, Di; Xing, Baoshan

    2014-05-01

    Iron is rich in soils, and is recently reported to form stable complexes with organic free radicals, generating environmentally persistent free radicals (EPFRs). The observation may challenge the common viewpoint that iron is an effective catalyst to facilitate the degradation of various organic chemicals. But no study was specifically designed to investigate the possible inhibited degradation of organic chemicals because of the formation of EPFRs in dry environment. We observed that catechol degradation under UV irradiation was decreased over 20% in silica particles coated with 1% hematite in comparison to uncoated silica particles. Stabilized semiquinone or quinine and phenol radicals were involved in HMT-silica system. EPFR formation was thus the reason for the reduced catechol degradation on HMT-silica surface under UV irradiation at ambient temperature. EPFRs should be incorporated in the studies of organic contaminants geochemical behavior, and will be a new input in their environmental fate modeling. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Multiple-barrier disinfection by chlorination and UV irradiation for desalinated drinking waters: chlorine photolysis and accelerated lamp-sleeve fouling effects.

    Science.gov (United States)

    Wait, Isaac W

    2008-11-01

    Experiments were conducted to quantify interaction effects between UV irradiation and chlorination for desalinated drinking water. The rate of chlorine photolysis in desalinated water was characterized using a low-pressure UV lamp and chlorine doses typical of drinking water treatment and was found to be lower than reported photolysis rates for treated surface water. Results indicate that, for most desalinated water applications, reduction in free chlorine is likely to be limited, but, depending on the UV dose used, not necessarily negligible. Investigation of the potential for reactor lamp-sleeve fouling included mineral speciation and solubility modeling and showed that chlorination of desalinated water before UV disinfection may increase lamp-sleeve fouling, particularly for point-of-use reactors. UV irradiation before chlorination may minimize fouling. Overall results point to the variable nature of UV lamp-sleeve fouling and chlorine photolysis and an intrinsic dependence on local water chemistry conditions.

  3. Antimutagenic action of aminoacids on UV-irradiated E. Coli cells: evidence of the existence of metabolic regulation of antimutagenic activity

    International Nuclear Information System (INIS)

    Filippov, V.D.

    1990-01-01

    The yield of mutations in Escherichia Coli cells placed after UV irradiation in a glucose-free salt medium enriched with casamino acids was determined. It is shown that in the absence of glucose casamino acids and certain individual amino acids produce a strong antimutagenetic effect. The acquired data allow to assume the existence of fine metabolic regulation of mutation reparation processes and occurrence of mutations in E. Coli cells exposed to UV-radiation

  4. UV-irradiation and leaching in water reduce the toxicity of imidacloprid-contaminated leaves to the aquatic leaf-shredding amphipod Gammarus fossarum.

    Science.gov (United States)

    Englert, Dominic; Zubrod, Jochen P; Neubauer, Christoph; Schulz, Ralf; Bundschuh, Mirco

    2018-05-01

    Systemic neonicotinoid insecticides such as imidacloprid are increasingly applied against insect pest infestations on forest trees. However, leaves falling from treated trees may reach nearby surface waters and potentially represent a neonicotinoid exposure source for aquatic invertebrates. Given imidacloprid's susceptibility towards photolysis and high water solubility, it was hypothesized that the leaves' toxicity might be modulated by UV-irradiation during decay on the forest floor, or by leaching and re-mobilization of the insecticide from leaves within the aquatic ecosystem. To test these hypotheses, the amphipod shredder Gammarus fossarum was fed (over 7 d; n = 30) with imidacloprid-contaminated black alder (Alnus glutinosa) leaves that had either been pre-treated (i.e., leached) in water for up to 7 d or UV-irradiated for 1 d (at intensities relevant during autumn in Central Europe) followed by a leaching duration of 1 d. Gammarids' feeding rate, serving as sublethal response variable, was reduced by up to 80% when consuming non-pretreated imidacloprid-contaminated leaves compared to imidacloprid-free leaves. Moreover, both leaching of imidacloprid from leaves (for 7 d) as well as UV-irradiation reduced the leaves' imidacloprid load (by 46 and 90%) thereby mitigating the effects on gammarids' feeding rate to levels comparable to the respective imidacloprid-free controls. Therefore, natural processes, such as UV-irradiation and re-mobilization of foliar insecticide residues in water, might be considered when evaluating the risks systemic insecticide applications in forests might pose for aquatic organisms in nearby streams. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. [Autologous transfusion of UV-irradiated blood in the complex treatment of children with dysplasia of deep veins of the extremities].

    Science.gov (United States)

    Levanovich, V V; Kupatadze, D D; Endzhibadze, Iu G; Nabokov, V V; Mazurova, E V; Ivanov, A P; Chirovich, M

    1991-02-01

    Under examination there were 12 patients aged from 5 till 14 years. An investigation of hemostatic potential of blood in the diseased extremity and peripheral blood was performed. A mosaic character of blood coagulative alterations in this category of patients was detected. Autotransfusion of UV-irradiated blood is a pathogenetically grounded and accessible method of correction of hemocoagulation and may be included in the complex treatment of patients with dysplasia of the profound veins of lower extremities.

  6. A development and biological safety evaluation of novel PVC medical devices with surface structures modified by UV irradiation to suppress plasticizer migration.

    Science.gov (United States)

    Haishima, Yuji; Isama, Kazuo; Hasegawa, Chie; Yuba, Toshiyasu; Matsuoka, Atsuko

    2013-09-01

    This study examines the chemical, physicochemical, and biological properties of PVC sheets treated with UV irradiation on their surfaces to suppress the elution of a plasticizer, di-(2-ethylhexyl) phthalate (DEHP), for developing novel polyvinyl chloride (PVC) medical devices. The PVC sheets irradiated under conditions 1 (52.5 μW/cm(2), 136 J/cm(2)) and 2 (0.45 mW/cm(2), 972 J/cm(2)) exhibited considerable toxicity in cytotoxicity tests and chromosome aberration tests due to the generation of DEHP oxidants, but no toxicity was detected in the PVC sheet irradiated under condition 3 (8.3 mW/cm(2), 134 J/cm(2)). The release of DEHP from the surface irradiated under condition 3 was significantly suppressed, and mono-(2-ethylhexyl) phthalate (MEHP) converted from a portion of DEHP could be easily removed from the surface by washing with methanol. The physicochemical properties of the surface regarding the suppression of DEHP elution remained stable through all sterilizations tested, but MEHP elution was partially recrudesced by the sterilizations except for gamma irradiation. These results indicated that UV irradiation using a strong UV-source over a short time (condition 3) followed by methanol washing and gamma sterilization may be useful for preparing novel PVC products that did not elute plasticizers and do not exhibit toxicity originating from UV irradiation. Copyright © 2013 Wiley Periodicals, Inc.

  7. The effect of caffeine on post-replication repair and survival in two L5178Y cell lines with different sensitivities to UV irradiation

    International Nuclear Information System (INIS)

    Walicka, M.; Beer, J.Z.; Koerner, I.; Malz, W.

    1978-01-01

    2 Strains of murine lymphoma L5178Y cells that varied from the point of view of sensitivity to UV irradiation (mean lethal doses: 3.6 and 8.5 J/m 2 for L5178Y-R and L5178Y-S cells, respectively) also differed with respect to sensitization by caffeine. L5178Y-S cells were sensitized to UV irradiation by 0.75 mM caffeine, whereas in the same conditions L5178Y-R cells were not sensitized. Sedimentation analysis of the newly synthesized DNA indicated UV-induced gap formation in L5178Y-S cells only. The subsequent gap filling was inhibited by caffeine. Exposure to UV irradiation induced no gaps in L5178Y-R cells. However, when caffeine was added immediately after irradiation, DNA with reduced molecular weight was found in irradiated cells of both strains after a 2-h chase. On the other hand, caffeine inhibited elongation of undamaged DNA strands in neither of the 2 cell strains. (Auth.)

  8. Modulation of in vitro transformation and the early and late modes of DNA replication of uv-irradiation Syrian hamster cells by caffeine

    International Nuclear Information System (INIS)

    Doniger, J.; DiPaolo, J.A.

    1981-01-01

    The effect of caffeine on post-uv DNA replication was studied to determine its relevance to carcinogenesis. The level of uv-induced transformed colonies of Syrian hamster embryo cells (HEC) was increased up to fivefold when caffeine was added to cells between 0 and 6 h post-uv. The greatest increase was observed when the interval between uv irradiation and caffeine addition was 4 h. Two modes of DNA replication occurred after uv irradiation. During the early mode (0 to 3 h post-uv) the size of nascent strands, as measured by alkaline sucrose sedimentation, was smaller than those in nonirradiated cells, whereas during the late mode they recovered to normal size. Caffeine inhibited the rate of elongation of nascent strands during the early mode. When caffeine was added immediately after uv irradiation, the conversion of the early mode to the late mode was inhibited. Studies on the effects of caffeine have now been extended to the late mode. While caffeine has little effect with the fd elements beginning from the 10th day after irradiation is connected with their proliferation but not with the migration out from lymphoid organs

  9. Influence of melanocytes in the ex-vivo reconstructed epidermal melanin unit following an acute UV irradiation

    International Nuclear Information System (INIS)

    Cario-Andre, M.

    2000-11-01

    Influence of melanocytes in skin pigmentation is well documented, however its photo-protective role has given rise to controversy. The role of melanocytes have been investigated on reconstructed epidermis with 100 % of keratinocytes or 95 % of keratinocytes and 5 % of melanocytes. In a first time, the effect of an acute UVB dose has been studied on both reconstructed epidermis, next we have investigated UVA and UVA+B effects on these epidermis. Following irradiation, the presence of melanocytes in reconstructed epidermis protects against apoptosis without protecting significantly against DNA damage formation (CPD, 6-4PP) and protects against UV-induced unbalance of the SOD/catalase ratio (antioxidants enzymes). On the contrary, the presence of melanocytes in reconstructed epidermis amplifies lipids and proteins oxidations but seems to protect against DNA oxidations. Melanocytes differ from keratinocytes by their melanin content and their more important concentration in polyunsaturated fatty acids. To evaluate what is the part of melanin and the part of polyunsaturated fatty acids in epidermal UV responses, reconstructed epidermis with keratinocytes have been supplemented with polyunsaturated fatty acid. This study indicates that polyunsaturated fatty acids are responsible for lipids and proteins oxidations and that melanin protect against DNA oxidation induced by lipid peroxidation. All these studies demonstrate that, model of reconstructed epidermis and epidermis in-vivo have the same behaviour following UV irradiation. In the last part, sunscreens and antioxidants have been tested on reconstructed epidermis and have demonstrated that model of reconstructed epidermis is suitable for photo-protective molecules screening. (author)

  10. Effect of low- and medium-pressure Hg UV irradiation on bromate removal in Advanced Reduction Process.

    Science.gov (United States)

    Jung, Bahngmi; Nicola, Rana; Batchelor, Bill; Abdel-Wahab, Ahmed

    2014-12-01

    Advanced Reduction Processes (ARP) have been developed by combining UV irradiation with reducing reagents, which produces reactive reducing free radicals that degrade contaminants (e.g. vinyl chloride, 1,2-dichloroethane, perchlorate, and bromate). This study investigates bromate destruction by ARPs using medium-pressure mercury UV light lamp (UV-M) and low-pressure mercury UV light lamp (UV-L). Effects of experimental parameters including initial bromate concentration, reducing reagent (sulfite) dose, and pH on bromate removal kinetics and quantum yield were evaluated. The pseudo-first-order rate constant (kobs) by UV-M ARP was greater by 3 times than that by UV-L ARP. UV-M and UV-L achieved a complete bromate removal of an initial concentration at 500 ppb with fluences of 10.5 J cm−2 and 73.5 J cm−2, respectively. It was found that direct photolysis is a dominant mechanism with the UV-M ARP showing that the effect of sulfite dose had no apparent influence on the bromate removal, whereas kobs was dependent on the sulfite doses in UV-L/sulfite ARP. In the presence of sulfite, kobs was affected by the solution pH in both the UV-M and UV-L ARPs. The pH effect on UV-L ARP or UV-M ARP was explained by the effect of pH on the sulfite species distribution between sulfite and bisulfite or the hydrated electrons concentrations. Also it was found that dominant reaction mechanism of bromate removal was changed by initial bromate concentrations, and its behavior was varied dependent on the UV light sources.

  11. Optical and electrical properties of merocyanine dye LB films by various time of UV irradiation and heat treatment.

    Science.gov (United States)

    Sung, Gi-Chan; Kang, Hyen-Wook; Lee, Ji-Yoon; Yang, Chang-Heon; Shin, Hoon-Kyu; Lee, Burm-Jong; Kwon, Young-Soo

    2011-05-01

    The Langmuir-Blodgett (LB) technique provides many possibilities for the control of film thickness, dimensions, and molecular structures on the nanometer scale. Various kinds of dye molecules have been found to form the J-aggregation which has been used as sensitizers of silver halide photography for long time. In recent years, they attract attention as model systems for investigating the ultra-fast exciton dynamics, materials for ultra-fast nonlinear optical devices, fluorescence probes for mitochondrial membranes. We fabricated the merocyanine dye LB films with arachidic acid (AA). In order to observe the J-aggregation of the merocyanine dye LB films, CdCl2 and KHCO3 solutions were added in subphase. From the optical absorption spectra of the mixed dye LB films (6Me-Ds:AA = 1:2) at different layers, the optical absorption peak was about 520 nm. However, the optical absorption peak of the LB films was shifted to 600 nm, when CdCl2 and KHCO3 solutions were added. This is the consequence result to the J-aggregation of the merocyanine dye. We also investigated the optical absorption peak of the LB films according to various time at 60 degrees C and 275 nm UV. We measured the STM morphology of the merocyanine dye LB film (1 layer) before UV irradiation and heat treatment. The morphology size of the LB film on HOPG was 5 nm. The roughness and molecular size were about 66.163 pm and 0.176 nm, respectively. The J-aggregation of this type was also accompanied by large morphological changes. We analyze the morphology and electrical properties of the LB films by the scanning tunneling microscopy (STM).

  12. High temperature in combination with UV irradiation enhances horizontal transfer of stx2 gene from E. coli O157:H7 to non-pathogenic E. coli.

    Directory of Open Access Journals (Sweden)

    Wan-Fu Yue

    Full Text Available Shiga toxin (stx genes have been transferred to numerous bacteria, one of which is E. coli O157:H7. It is a common belief that stx gene is transferred by bacteriophages, because stx genes are located on lambdoid prophages in the E. coli O157:H7 genome. Both E. coli O157:H7 and non-pathogenic E. coli are highly enriched in cattle feedlots. We hypothesized that strong UV radiation in combination with high temperature accelerates stx gene transfer into non-pathogenic E. coli in feedlots.E. coli O157:H7 EDL933 strain were subjected to different UV irradiation (0 or 0.5 kJ/m(2 combination with different temperature (22, 28, 30, 32, and 37 °C treatments, and the activation of lambdoid prophages was analyzed by plaque forming unit while induction of Stx2 prophages was quantified by quantitative real-time PCR. Data showed that lambdoid prophages in E. coli O157:H7, including phages carrying stx2, were activated under UV radiation, a process enhanced by elevated temperature. Consistently, western blotting analysis indicated that the production of Shiga toxin 2 was also dramatically increased by UV irradiation and high temperature. In situ colony hybridization screening indicated that these activated Stx2 prophages were capable of converting laboratory strain of E. coli K12 into new Shiga toxigenic E. coli, which were further confirmed by PCR and ELISA analysis.These data implicate that high environmental temperature in combination with UV irradiation accelerates the spread of stx genes through enhancing Stx prophage induction and Stx phage mediated gene transfer. Cattle feedlot sludge are teemed with E. coli O157:H7 and non-pathogenic E. coli, and is frequently exposed to UV radiation via sunlight, which may contribute to the rapid spread of stx gene to non-pathogenic E. coli and diversity of shiga toxin producing E. coli.

  13. Tailoring of TiO2films by H2SO4treatment and UV irradiation to improve anticoagulant ability and endothelial cell compatibility.

    Science.gov (United States)

    Liao, Yuzhen; Li, Linhua; Chen, Jiang; Yang, Ping; Zhao, Ansha; Sun, Hong; Huang, Nan

    2017-07-01

    Surfaces with dual functions that simultaneously exhibit good anticoagulant ability and endothelial cell (EC) compatibility are desirable for blood contact materials. However, these dual functions have rarely been achieved by inorganic materials. In this study, titanium dioxide (TiO 2 ) films were treated by sulphuric acid (H 2 SO 4 ) and ultraviolet (UV) irradiation successively (TiO 2 H 2 SO 4 -UV), resulting in good anticoagulant ability and EC compatibility simultaneously. We found that UV irradiation improved the anticoagulant ability of TiO 2 films significantly while enhancing EC compatibility, though not significantly. The enhanced anticoagulant ability could be related to the oxidation of surface-adsorbed hydrocarbons and increased hydrophilicity. The H 2 SO 4 treatment improved the anticoagulant ability of TiO 2 films slightly, while UV irradiation improved the anticoagulant ability strongly. The enhanced EC compatibility could be related to the increased surface roughness and positive charges on the surface of the TiO 2 films. Furthermore, the time-dependent degradation of the enhanced EC compatibility and anticoagulant ability of TiO 2 H 2 SO 4 -UV was observed. In summary, TiO 2 H 2 SO 4 -UV expressed both excellent anticoagulant ability and good EC compatibility at the same time, which could be desirable for blood contact materials. However, the compatibility of TiO 2 H 2 SO 4 -UV with smooth muscle cells (SMCs) and macrophages was also improved. More effort is still needed to selectively improve EC compatibility on TiO 2 films for better re-endothelialization. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. High sensitivity but normal DNA-repair activity after UV irradiation in Epstein-Barr virus-transformed lymphoblastoid cell lines from Chediak-Higashi syndrome

    International Nuclear Information System (INIS)

    Tanaka, H.; Orii, T.

    1980-01-01

    We established lymphoblastoid cell lines from 2 children with Chediak-Higashi syndrome (CHS), 2 xeroderma pigmentosum (XP) patients and control donors after transformation of peripheral lymphocytes by Epstein-Barr virus (EBV). We used these lymphoblastoid cell lines to investigate repair activity after ultraviolet irradiation. Cell survival of both CHS lymphoblastoid cell lines after irradiation by UV and treatment by 4-nitroquinoline 1-oxide (4NQO) fell between those of the XP and control cells lines. Unscheduled DNA synthesis of CHS cells after UV irradiation occured at rates similar to those of control cells. (orig.)

  15. Enhanced reactivation of UV-irradiated adenovirus 2 is not associated with enhanced mutagenesis in carcinogen-pretreated HeLa cells.

    Science.gov (United States)

    Piperakis, S M

    1987-11-01

    Treatment of HeLa cells with low doses of the carcinogens aflatoxin B1, methyl methanesulfonate (MMS) or ethyl methanesulfonate (EMS) increases the survival rate of UV-irradiated adenovirus 2 (ade2). This increase is maximal if the time interval between cell treatment and virus infection is delayed by 36 h. No enhanced mutagenesis was found measuring the reversion frequency of a temperature-sensitive mutant of ade2 grown in HeLa cells treated with the same carcinogens. The enhanced viral reactivation observed does not, therefore, display a significant error-prone component.

  16. Effects of the ssb-1 and ssb-113 mutations on survival and DNA repair in UV-irradiated delta uvrB strains of Escherichia coli K-12.

    OpenAIRE

    Wang, T C; Smith, K C

    1982-01-01

    The molecular defect in DNA repair caused by ssb mutations (single-strand binding protein) was studied by analyzing DNA synthesis and DNA double-strand break production in UV-irradiated Escherichia coli delta uvrB strains. The presence of the ssb-113 mutation produced a large inhibition of DNA synthesis and led to the formation of double-strand breaks, whereas the ssb-1 mutation produced much less inhibition of DNA synthesis and fewer double-strand breaks. We suggest that the single-strand bi...

  17. Effects of UV irradiation on humic acid removal by ozonation, Fenton and Fe{sup 0}/air treatment: THMFP and biotoxicity evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Ming-Chi [Department of Food Science, Central Taiwan University of Science and Technology, Taichung, Taiwan, ROC (China); Wang, Kai-sung; Hsiao, Tung-En; Lin, I.-Chen; Wu, Hui-Ju [Department of Public Health, Chung-Shan Medical University, Taichung 402, Taiwan, ROC (China); Wu, Yuh-Luan; Liu, Pey-Horng [Green Energy and Environment Research Laboratories, Industrial Technology Research Institute, Taiwan, ROC (China); Chang, Shih-Hsien, E-mail: shchang@csmu.edu.tw [Department of Public Health, Chung-Shan Medical University, Taichung 402, Taiwan, ROC (China); Department of Family and Community Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan, ROC (China)

    2011-11-15

    Highlights: {yields} Fe{sup 0}/air rapidly and effectively removed HA within 9 min and its COD, biotoxicity and THMFP were low. {yields} THMFP of ozonation-treated solution was much higher than those of Fenton-treated and Fe{sup 0}/air-treated solutions. {yields} UV irradiation during ozonation and Fenton oxidation enhanced HA removal, but did not reduce the THMFP of the treated solutions. {yields} Fe{sup 0}/air treatment with UV irradiation obviously increased the THMFP of the treated solution. {yields} The relationship between biotoxicity and chloroform in the chlorinated solution was insignificant. - Abstract: Effects of UV irradiation on humic acid (HA) removal by Fe{sup 0}/air, ozonation and Fenton oxidation were investigated. The trihalomethane forming potential (THMFP) and toxicity of treated solutions were also evaluated. The experimental conditions were ozone of 21 mg min{sup -1}, H{sub 2}O{sub 2} of 8 x 10{sup -4} M, Fe{sup 0} of 20 g L{sup -1}, air flow of 5 L min{sup -1}, and UVC of 9 W. Results indicated that Fe{sup 0}/air rapidly removed HA color (>99%) and COD (90%) within 9 min. 51-81% of color and 43-50% of COD were removed by ozonation and Fenton oxidation after 60 min. Both UV enhanced ozone and Fenton oxidation removed HA, but the Fe{sup 0}/air process did not. Spectrum results showed all processes effectively diminished UV-vis spectra, except for ozonation. The THMFP of Fe{sup 0}/air-treated solution (114 {mu}g L{sup -1}) was much lower than those of Fenton- (226 {mu}g L{sup -1}) and ozonation-treated solutions (499 {mu}g L{sup -1}). Fe{sup 0}/air with UV irradiation obviously increased the THMFP of treated solution (502 {mu}g L{sup -1}). The toxicity results obtained from Vibrio fischeri light inhibition test indicated that the toxicity of Fe{sup 0}/air-treated solution (5%) was much lower than that of ozonation- (33%) and Fenton-treated solutions (31%). Chlorination increased the solution toxicity. The correlation between biotoxicity and

  18. Control of the amount of free molecular iodine in iodine germicides.

    Science.gov (United States)

    Hickey, J; Panicucci, R; Duan, Y; Dinehart, K; Murphy, J; Kessler, J; Gottardi, W

    1997-12-01

    Horseradish peroxidase has been used to generate iodine compositions that comprised principally free molecular iodine. The concentration of free molecular iodine in these enzyme-based compositions ranged from 44 to 63% of the thiosulphate titratable iodine; this is substantially higher than the corresponding value for the povidone-iodine preparation betadine. The biocidal efficacy of these compositions was proportional to the concentration of free molecular iodine. Iodine compositions with relatively low total iodine concentrations but high levels of free molecular iodine (20-175 ppm) killed Staphylococcus aureus and spores of Bacillus subtilis more rapidly than betadine. The effects of normal saline and these enzyme-based iodine compositions on the rate of epidermal regeneration in superficial swine wounds were comparable. These results suggest that an effective germicide containing a high level of molecular iodine need not be irritating or toxic.

  19. Failure of RNA synthesis to recover after UV irradiation: an early defect in cells from individuals with Cockayne's syndrome and xeroderma pigmentosum

    International Nuclear Information System (INIS)

    Mayne, L.V.; Lehmann, A.R.

    1982-01-01

    Previous work has shown that in cells from the ultraviolet-sensitive genetic disorder, Cockayne's syndrome, DNA synthesis fails to recover after ultraviolet irradiation, despite the fact that these cells have no detectable defect in either excision or daughter-strand repair pathways. We now show that Cockayne cells, as well as cells from a number of patients with xeroderma pigmentosum, are sensitive to the lethal effects of UV irradiation in stationary phase under conditions in which no DNA is synthesized after irradiation. Furthermore, in normal and defective human fibroblasts, RNA synthesis is depressed after UV irradiation. In normal (dividing) cells, RNA synthesis recovers very rapidly, but this recovery does not occur in Cockayne cells, and it is reduced or absent in xeroderma pigmentosum cells from different complementation groups. Qualitatively, similar results are obtained with cells in stationary phase. The recovery of RNA synthesis in the various defective cell strains is not correlated with the overall extent of excision repair, but there is some correlation between recovery of RNA synthesis and cell survival after ultraviolet irradiation. These results implicate recovery of RNA synthesis as an important early response to ultraviolet irradiation

  20. Synergistic effect of polyoxometalate solution and TiO2 under UV irradiation to catalyze formic acid degradation and their application in the fuel cell and hydrogen evolution

    Directory of Open Access Journals (Sweden)

    Congmin Liu

    2017-10-01

    Full Text Available The synergistic effect of H3PMo12O40 or H3PW12O40 polyoxometalate solution (POM and TiO2 to catalyze formic acid oxidation was investigated. Under UV irradiation, hole and electron were photogenerated by TiO2. Formic acid was oxided by the photogenerated hole and photogenerated electron was transferred to reduce polyoxometalate. With this design, formic acid can be converted into electricity in the fuel cell and hydrogen can be generated in the electrolysis cell without noble metal catalyst. Unlike other noble metal catalysts applied in the fuel cells and electrolysis cell, POM and TiO2 are stable and low cost. The maximum output power density of liquid formic acid fuel cell after 12 h UV irradiation is 5.21 mW/cm2 for phosphmolybdic acid and 22.81 mW/cm2 for phosphotungstic acid respectively. The applied potential for the hydrogen evolution is as low as 0.8 V for phosphmolybdic acid and 0.6 V for phosphotungstic acid. Keywords: TiO2, UV, Polyoxometalate solution (POM, Fuel cell, Hydrogen evolution

  1. Thio and hydrogen peroxide modofication of recA induction in UV-irradiated wild-type and catalase-deficient Escherichia coli K12

    International Nuclear Information System (INIS)

    Claycamp, H.G.; Kam-Kuen Ho; DeRose, C.; Iowa Univ., Iowa City, IA

    1990-01-01

    Induction of recA in Escherichia coli, monitored as β-D-galactosidase activity in recA-lacZ fusion strains, was shown to be elevated and prolonged by dithiothreitol (DTT) treatment after far-UV radiation. Pretreatment of UV-irradiated coltures using DTT led to a shortened recA response and little increase of β-Gal yield. Similar studies were performed using a catalase-deficient recA-lacZ strain in which the major feature was elevated levels of recA-lacZ induction. Catalase activity in UV-irradiated wild-type cells was reduced by DTT treatment to levels as low as in a katE mutant strain, leading to similar recA-lacZ induction patterns between the strains. Neither DTT nor H 2 O 2 treatment of cells could induce significant recA transcription in the absence of UV-radiation, implying that both agents modify recA activity primarily by interfering with repair of recA-inducing DNA lesions. The results confirm previous studies suggesting that modification of DNA repair is probably a significant portion of thiol radiation protection. (author). 36 refs.; 7 figs.; 1 tab

  2. Thermal annealing and UV irradiation effects on structure, morphology, photoluminescence and optical absorption spectra of EDTA-capped ZnS nanoparticles

    Science.gov (United States)

    Osman, M. A.; Othman, A. A.; El-Said, Waleed A.; Abd-Elrahim, A. G.; Abu-sehly, A. A.

    2016-02-01

    Monodispersed ZnS nanoparticles (NPs) were prepared by the chemical precipitation method. Thermally induced structural, morphological and optical changes have been investigated using x-ray diffraction, high-resolution transmission electron microscopy, optical absorption, photoluminescence (PL), and Fourier transform infrared and Raman spectroscopy. It was found that D increases with increasing annealing temperature (T a). The onset of the ZnS phase transition from cubic to hexagonal structure takes place at 400 °C, while cubic ZnS transforms into hexagonal ZnO via thermal oxidation in air at 600 °C. It is also noted that increasing T a results in the red shift of the optical band gap (E\\text{g}\\text{opt} ) and the thermal bleaching of exciton absorption. The PL spectrum of as-prepared ZnS nanopowder shows UV emission bands at 363 and 395 nm and blue and green emission at 438 and 515 nm, respectively. With increasing T a up to 500 °C, these bands were quenched and red-shifted. In addition, the UV irradiation effects on colloidal ZnS NPs were investigated. UV irradiation at a dose  ZnS NPs was discussed and an energy band diagram was proposed.

  3. Fouling Removal of UF Membrane with Coated TiO2 Nanoparticles under UV Irradiation for Effluent Recovery during TFT-LCD Manufacturing

    Directory of Open Access Journals (Sweden)

    S. H. You

    2013-01-01

    Full Text Available An ultrafiltration (UF membrane process was employed to treat the secondary effluent discharged from a manufacturing of thin film transistor-liquid crystal display (TFT-LCD in this study. A bench-scale system was performed to evaluate the fouling removal of a UF membrane with coated titanium dioxide (TiO2 nanoparticles under UV irradiation. The operating pressure and feed temperature were controlled at 300 KN/m2 and 25°C, respectively. It was found that the optimum operating conditions were attained with TiO2 concentrations of 10 wt% for both 5 KD and 10 KD MWCO. Continuous UV irradiation of 5 KD MWCO improved the permeate flux rate from 45.0% to 59.5% after 4 hours of operation. SEM-EDS analysis also showed that the photocatalytic effect had reduced the average thickness of cake fouling on the membrane from 6.40 μm to 2.70 μm for 5 KD MWCO and from 6.70 μm to 3.1 μm for 10 KD MWCO. In addition, the membrane contact angle was reduced from 54° to 44°. The photocatalytic properties of TiO2 apparently increased the hydrophilicity of the membrane surface, thereby reducing membrane fouling.

  4. Stable Internal Reference Genes for Normalizing Real-Time Quantitative PCR in Baphicacanthus cusia under Hormonal Stimuli and UV Irradiation, and in Different Plant Organs

    Directory of Open Access Journals (Sweden)

    Yuxiang Huang

    2017-05-01

    Full Text Available Baphicacanthus cusia (Nees Bremek, the plant source for many kinds of drugs in traditional Chinese medicine, is widely distributed in South China, especially in Fujian. Recent studies about B. cusia mainly focus on its chemical composition and pharmacological effects, but further analysis of the plant's gene functions and expression is required to better understand the synthesis of its effective compounds. Real-time quantitative polymerase chain reaction (RT-qPCR is a powerful method for gene expression analysis. It is necessary to select a suitable reference gene for expression normalization to ensure the accuracy of RT-qPCR results. Ten candidate reference genes were selected from the transcriptome datasets of B. cusia in this study, and the expression stability was assessed across 60 samples representing different tissues and organs under various conditions, including ultraviolet (UV irradiation, hormonal stimuli (jasmonic acid methyl ester and abscisic acid, and in different plant organs. By employing different algorithms, such as geNorm, NormFinder, and BestKeeper, which are complementary approaches based on different statistical procedures, 18S rRNA was found to be the most stable gene under UV irradiation and hormonal stimuli, whereas ubiquitin-conjugating enzyme E2 was the best suitable gene for different plant organs. This novel study aimed to screen for suitable reference genes and corresponding primer pairs specifically designed for gene expression studies in B. cusia, in particular for RT-qPCR analyses.

  5. Influence of fiber surface-treatment on interfacial property of poly(L-lactic acid)/ramie fabric biocomposites under UV-irradiation hydrothermal aging

    International Nuclear Information System (INIS)

    Chen Dakai; Li Jing; Ren Jie

    2011-01-01

    Research highlights: → Ramie fiber is used as reinforced material because it's lowest water absorption among sisal, jute, kenaf and ramie fiber. → Fiber surface-treatment can cause an accelerated decline in mechanical properties of PLLA biocomposites after UV-irradiation hydrothermal aging. → The swelling of ramie fibers reduce the interfacial adhesive strength in critical area of PLLA matrix-ramie fabric interface. - Abstract: The present study is devoted to the effect of fiber surface-treatment on the interfacial property of biocomposites based on poly(L-lactic acid) (PLLA) and ramie fabric. Ramie fiber is used as reinforced material because it's lowest water absorption among sisal, jute, kenaf and ramie fiber. Fiber surface-treatment can increase the water absorption of natural fibers. SEM images show that PLLA biocomposites with treated ramie fabric exhibit better interfacial adhesion character. DMA results show that the storage modulus of PLLA biocomposites with treated ramie increase compared to neat PLLA and PLLA biocomposites with untreated ramie. Unexpectedly, fiber surface-treatment can cause an accelerated decline in mechanical properties of PLLA biocomposites after UV-irradiation hydrothermal aging. Finally, GPC results show that there is no obvious decline in the molecular weight of PLLA. The main reason for this decline is the interfacial destructive effect induced by the water absorption of ramie fiber.

  6. Arterial and venous oxygen partial pressure and utilization factor η, resp., and 133Xe muscle clearance after UV irradiation of skin or blood of healthy persons and patients with occlusive arterial disease and psoriasis, resp

    International Nuclear Information System (INIS)

    Scherf, H.P.; Strangfeld, D.; Meffert, H.; Glatzel, E.; Siewert, H.; Soennichsen, N.; Correns, H.J.

    1988-01-01

    In three teams of test persons series of UV irradiations of the skin (λ max 365 nm) and of the blood (λ max 254 nm) were performed, and moreover pseudoirradiations of the blood as placebo and infrared irradiations of the skin were carried out. UV irradiations of the blood increased the factor η (O 2 utilization) in all test persons. In healthy persons and patients with psoriasis UV irradiations of the skin involved a homogeneous, but less distinct effect, this was, however, not the case in patients with vascular diseases. According to the results of the 133 Xe muscle clearance the improved utilization of oxygen does not result from increased peripheral blood supply. (author)

  7. The effect of caffeine on p53-dependent radioresponses in undifferentiated mouse embryonal carcinoma cells after X-ray and UV-irradiations

    International Nuclear Information System (INIS)

    Taga, Masataka; Shiraishi, Kazunori; Shimura, Tsutomu; Uematsu, Norio; Kato, Tomohisa; Niwa, Ohtsura; Nishimune, Yoshitake; Aizawa, Shinichi; Oshimura, Mitsuo

    2000-01-01

    The effect of caffeine was studied on the radioresponses of undifferentiated mouse embryonal carcinoma cells (EC cells) with or without the functional p53. The radioresponses studied included radiosensitivity, the activation of p53, apoptosis with characteristic DNA ladder formation and cell cycle progression. An undifferentiated mouse EC cell line, ECA2, and a newly established p53-deficient EC cell line, p53δ, were used in the present study. The status of the p53 gene did not significantly affect the colony survivals of undifferentiated EC cells to X-rays and UV. Although a post-irradiation treatment with caffeine sensitized both lines to X-rays marginally, the sensitization was prominent for UV regardless of the p53 status of the cells. The activation of a p53 responsible lacZ reporter construct was observed in stably transfected ECA2 cells after X-ray and UV irradiations. Caffeine suppressed the X-ray induced activation of the lacZ reporter, while it drastically enhanced the activation after UV irradiation. X-rays and UV readily triggered the apoptosis of ECA2 cells with the characteristic DNA ladder. Although UV-induced DNA ladder formation was enhanced by caffeine, that induced by X-rays was unaffected. Therefore, the effects of caffeine on the p53-dependent radioresponses were found to be agent specific: suppression for the X-ray induced and augmentation for the UV induced. In contrast to p53-proficient ECA2 cells, smear-like DNA degradation was observed for irradiated p53δ cells, suggesting the presence of a mode of cell death without DNA ladder formation. UV induction of the smear-like DNA degradation was enhanced in the presence of caffeine. Regardless of the state of the p53 gene, G1/S arrest was not observed in X-ray and UV irradiated EC cells. X-rays induced G2/M arrest in both lines, which was abrogated by caffeine, while G2/M arrest after UV was unaffected by a caffeine treatment. These results indicate that the radioresponses of undifferentiated

  8. The growth of a c-axis highly oriented sandwiched TiO{sub 2} film with superhydrophilic properties without UV irradiation on SnO:F substrate

    Energy Technology Data Exchange (ETDEWEB)

    Han Yangang; Wu Gang; Wang Mang; Chen Hongzheng [Department of Polymer Science and Engineering, Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China)], E-mail: wmang@zju.edu.cn, E-mail: hzchen@zju.edu.cn

    2009-06-10

    A c-axis highly oriented sandwiched film composed of single-crystalline rutile TiO{sub 2} on SnO:F (FTO) substrate was fabricated by a simple hydrothermal technique. The sandwich structure of the TiO{sub 2} film was found to be constructed by two layers of TiO{sub 2} nanorods, which grew towards both directions of the bulk solution and the substrate, respectively. One TiO{sub 2} nanoparticle interlayer between them acted as the 'seed' layer. The length and the density of the TiO{sub 2} nanoarrays could be tuned by varying the experimental parameters such as temperature and time. The resultant TiO{sub 2} films showed a specific superhydrophilicity without any prior UV irradiation, which can be kept for a long period of time.

  9. Effect of UV Irradiation on Mechanical and Morphological Properties of Natural and Synthetic Fabric Before and After Nano-Tio2 Padding

    Directory of Open Access Journals (Sweden)

    Wiener J.

    2017-12-01

    Full Text Available In this study, the effect of UV irradiation on mechanical properties of both natural and synthetic fabrics is investigated. Also the UV degradation of fabrics before and after TiO2 padding is studied. Cotton is used as natural fabric, and polyester, polypropylene, and polyamide were used as synthetic fabrics. After deposition with TiO2, prepared samples were irradiated by different dosage of UV light and the changes in fiber surface and the adhesion of nanoparticles is tested. The scanning electron microscopy, elemental analyses of Ti, and other methods were used. In some cases, the effect of stabilization of nanoparticles on fibers by UV light was realized. Reasons of this stabilization are the surface changes of polymer fibers-increase in surface roughness and oxidation of surface.

  10. Biological treatment of potato processing wastewater for red pigment production by immobilized cells of UV-irradiated monascus sp. in repeated batch

    International Nuclear Information System (INIS)

    Khalaf, S.A.

    2004-01-01

    Potato processing wastewater (PPW) was collected and analyzed for biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total nitrogen and starch content. A fungal strain isolated from PPW identified as Monascus sp. PPW was evaluated for its ability to grow and produce red pigment, biomass and reduce the starch content of the ,PPW. Active UV-irradiated isolate of the above strain was obtained by exposing the parent strain to UV-radiation and coded Monascus. sp. PPW-UV7 and used as immobilized cell system for PPW treatment process in repeated batch fermentation. The immobilized cells (in sponge cubes) were able to reduce COD by about 85.7 %, with biomass production of 9.22 gl+ l and over productivity of red pigment of 2.6 gl+ 1 after 8 days fermentation (2 batches). The immobilized cells showed stability and viability for 8 batches (32 days) during the process treatment

  11. Optical manipulation of Saccharomyces cerevisiae cells reveals that green light protection against UV irradiation is favored by low Ca2+ and requires intact UPR pathway.

    Science.gov (United States)

    Farcasanu, Ileana C; Mitrica, Radu; Cristache, Ligia; Nicolau, Ioana; Ruta, Lavinia L; Paslaru, Liliana; Comorosan, Sorin

    2013-11-01

    Optical manipulation of Saccharomyces cerevisiae cells with high density green photons conferred protection against the deleterious effects of UV radiation. Combining chemical screening with UV irradiation of yeast cells, it was noted that the high density green photons relied on the presence of intact unfolded protein response (UPR) pathway to exert their protective effect and that the low Ca(2+) conditions boosted the effect. UPR chemical inducers tunicamycin, dithiotreitol and calcium chelators augmented the green light effect in a synergic action against UV-induced damage. Photo-manipulation of cells was a critical factor since the maximum protection was achieved only when cells were pre-exposed to green light. Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  12. Human p38δ MAP kinase mediates UV irradiation induced up-regulation of the gene expression of chemokine BRAK/CXCL14

    International Nuclear Information System (INIS)

    Ozawa, Shigeyuki; Ito, Shin; Kato, Yasumasa; Kubota, Eiro; Hata, Ryu-Ichiro

    2010-01-01

    The mitogen-activated protein kinase (MAPK) family comprises ERK, JNK, p38 and ERK5 (big-MAPK, BMK1). UV irradiation of squamous cell carcinoma cells induced up-regulation of gene expression of chemokine BRAK/CXCL14, stimulated p38 phosphorylation, and down-regulated the phosphorylation of ERK. Human p38 MAPKs exist in 4 isoforms: p38α, β, γ and δ. The UV stimulation of p38 phosphorylation was not inhibited by the presence of SB203580 or PD169316, inhibitors of p38α and β, suggesting p38 phosphorylation was not dependent on these 2 isoforms and that p38γ and/or δ was responsible for the phosphorylation. In fact, inhibition of each of these 4 p38 isoforms by the introduction of short hairpin (sh) RNAs for respective isoforms revealed that only shRNA for p38δ attenuated the UV-induced up-regulation of BRAK/CXCL14 gene expression. In addition, over-expression of p38 isoforms in the cells showed the association of p38δ with ERK1 and 2, concomitant with down-regulation of ERK phosphorylation. The usage of p38δ isoform by UV irradiation is not merely due to the abundance of this p38 isoform in the cells. Because serum deprivation of the cells also induced an increase in BRAK/CXCL14 gene expression, and in this case p38α and/or β isoform is responsible for up-regulation of BRAK/CXCL14 gene expression. Taken together, the data indicate that the respective stress-dependent action of p38 isoforms is responsible for the up-regulation of the gene expression of the chemokine BRAK/CXCL14.

  13. Increased formation of halomethanes during chlorination of chloramphenicol in drinking water by UV irradiation, persulfate oxidation, and combined UV/persulfate pre-treatments.

    Science.gov (United States)

    Wenhai, Chu; Tengfei, Chu; Erdeng, Du; Deng, Yang; Yingqing, Guo; Naiyun, Gao

    2016-02-01

    Ultraviolet/persulfate (UV/PS) has been widely used to generate sulfate radicals for degradation of water organic pollutants in previous studies. However, its impacts on disinfection byproduct formation during post-chlorination of degraded compounds is unclear. The objective of this study was to evaluate the impacts of UV irradiation, PS oxidation, and the combined UV/PS advanced oxidation process (AOP) pre-treatments on halomethane formation during the following chlorination of chloramphenicol (CAP), a model antibiotic commonly found in wastewater-impacted water. Results showed that CAP could be transformed to more trichloromethane (TCM) than monochloromethane (MCM) and dichloromethane (DCM) in the presence of excess chlorine. UV photolysis, PS oxidation and UV/PS AOP all directly decomposed CAP to produce halomethanes (HMs) before post-chlorination. Moreover, UV and UV/PS pre-treatments both enhanced the formation of all the HMs in the subsequent chlorination. PS pre-oxidation decreased the TCM formation during post-chlorination, but increased the yields of MCM, DCM and total HMs. UV pre-irradiation significantly increased the bromide utilization of HMs, whereas UV/PS pre-oxidation decreased the bromine incorporation and utilization of HMs from the chlorination of CAP in a low-bromide water. UV irradiation, PS oxidation, and UV/PS AOP can inactivate pathogens and degrade organic pollutants, but this benefit should be weighed against a potential risk of the increased halomethane formation from degraded organic pollutants with and without post-chlorination. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. H2O2 and/or TiO2 photocatalysis under UV irradiation for the removal of antibiotic resistant bacteria and their antibiotic resistance genes

    International Nuclear Information System (INIS)

    Guo, Changsheng; Wang, Kai; Hou, Song; Wan, Li; Lv, Jiapei; Zhang, Yuan; Qu, Xiaodong; Chen, Shuyi; Xu, Jian

    2017-01-01

    Highlights: • TiO 2 thin film was successfully synthesized for treating ARB and ARGs from water. • More than 5.5 log units of ARB reduction was achieved by TiO 2 under UV irradiation. • With TiO 2 , ARGs were reduced by more than 5 log units under UV irradiation. • TiO 2 could remove both intracellular and extracellular forms of ARGs. - Abstract: Inactivating antibiotic resistant bacteria (ARB) and removing antibiotic resistance genes (ARGs) are very important to prevent their spread into the environment. Previous efforts have been taken to eliminate ARB and ARGs from aqueous solution and sludges, however, few satisfying results have been obtained. This study investigated whether photocatalysis by TiO 2 was able to reduce the two ARGs, mecA and ampC, within the host ARB, methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, respectively. The addition of H 2 O 2 and matrix effect on the removal of ARB and ARGs were also studied. TiO 2 thin films showed great effect on both ARB inactivation and ARGs removal. Approximately 4.5-5.0 and 5.5–5.8 log ARB reductions were achieved by TiO 2 under 6 and 12 mJ/cm 2 UV 254 fluence dose, respectively. For ARGs, 5.8 log mecA reduction and 4.7 log ampC reduction were achieved under 120 mJ/cm 2 UV 254 fluence dose in the presence of TiO 2 . Increasing dosage of H 2 O 2 enhanced the removal efficiencies of ARB and ARGs. The results also demonstrated that photocatalysis by TiO 2 was capable of removing both intracellular and extracellular forms of ARGs. This study provided a potential alternative method for the removal of ARB and ARGs from aqueous solution.

  15. Solvent-free thermoplastic-poly(dimethylsiloxane) bonding mediated by UV irradiation followed by gas-phase chemical deposition of an adhesion linker

    Science.gov (United States)

    Ahn, S. Y.; Lee, N. Y.

    2015-07-01

    Here, we introduce a solvent-free strategy for bonding various thermoplastic substrates with poly(dimethylsiloxane) (PDMS) using ultraviolet (UV) irradiation followed by the gas-phase chemical deposition of aminosilane on the UV-irradiated thermoplastic substrates. The thermoplastic substrates were first irradiated with UV for surface hydrophilic treatment and were then grafted with vacuum-evaporated aminosilane, where the alkoxysilane side reacted with the oxidized surface of the thermoplastic substrate. Next, the amine-terminated thermoplastic substrates were treated with corona discharge to oxidize the surface and were bonded with PDMS, which was also oxidized via corona discharge. The two substrates were then hermetically sealed and pressed under atmospheric pressure for 30 min at 60 °C. This process enabled the formation of a robust siloxane bond (Si-O-Si) between the thermoplastic substrate and PDMS under relatively mild conditions using an inexpensive and commercially available UV lamp and Tesla coil. Various thermoplastic substrates were examined for bonding with PDMS, including poly(methylmethacrylate) (PMMA), polycarbonate (PC), poly(ethyleneterephthalate) (PET) and polystyrene (PS). Surface characterizations were performed by measuring the contact angle and performing x-ray photoelectron spectroscopy analysis, and the bond strength was analyzed by conducting various mechanical force measurements such as pull, delamination, leak and burst tests. The average bond strengths for the PMMA-PDMS, PC-PDMS, PET-PDMS and PS-PDMS assemblies were measured at 823.6, 379.3, 291.2 and 229.0 kPa, respectively, confirming the highly reliable performance of the introduced bonding strategy.

  16. The ESR signals in silk fibroin and wool keratin under both the effect of UV-irradiation and without any external effects and the formation of free radicals.

    Science.gov (United States)

    Mamedov, Sh V; Aktas, B; Cantürk, M; Aksakal, B; Alekperov, V; Bülbül, F; Yilgin, R; Aslanov, R B

    2002-08-01

    ESR studies have been done on natural and UV-irradiated silk fibroins and wool keratins at the temperature range of -196 degrees C to 20 C. The intensities of ESR signals obtained from the irradiated samples at -196 C remarkably increase with respect to those of natural samples. While the signals mainly consist of triplet peaks at -196 C. a doublet arises around the room temperatures. For the first time, at room temperature without any external effect the complicated ESR spectra of fibrous proteins (wool keratin and silk fibroin) whose components are as follows have been observed: (1) (for white wool keratin) a central doublet with deltaHm = 1.1 mT and g = 2.0075; deltaHm = 5mT and g = 2.1911; (2) a wide peak with deltaHm approximately 66 mT and g approximately 2.1575; (3) the 'sulfur' peak given in the literature with deltaHm = 2.2 mT and g = 2.0218; (4) the signal with deltaHm = 0.6 mT and g = 2.0065, and for silk fibroin, (a) a very wide signal with deltaHm approximately 70 mT and g approximately 2.084; (b) a very sharp signal with deltaHm approximately 1.1 mT and g approximately 2.01; and (c) relatively narrower signal with deltaHm approximately 5 mT and g approximately 2.336. It has been shown by recombination kinetic method that 30-50% of the free radicals formed by UV-irradiation do not undergo recombination up to 220 degrees C and 15 degrees C for silk libroin and wool keratin, respectively, even they keep their concentration constant for long period of time (weeks, months, even longer). In this article, considering above-mentioned results, the mechanism of signals observed in natural wool keratin and silk fibroin without any external effects is examined. We can briefly explain the role of the subject of the article, by considering fibrous proteins and some applications of the reactions by free radical occurring in these proteins tinder the effects of different factors in medicine and biology and the important role of oxidation and the other kinds of

  17. Modelling of Disinfection by-products formation via UV irradiation of the water from Tajan River (source water for Sari drinking water, Iran

    Directory of Open Access Journals (Sweden)

    Allahbakhsh Javid

    2013-11-01

    Full Text Available Background & Aims of the Study Irradiation with ultraviolet light (UV is used for the disinfection of bacterial contaminants in the production of potable water. The main objective of the study was to investigate and model Disinfection By-Products (DBPs formation due to the UV Irradiation of the Tajan River water under different Irradiation conditions. Materials & Methods:  Water samples were collected throughout September 2011 to August 2013. Transportation of the sample to the laboratory was done on ice in a cooler, and physiochemical analysis was conducted immediately within one day. Dissolved organic carbon (DOC was determined by a TOC analyzer. Irradiation experiments were conducted in a series of 25 mL glass serum bottles with Teflon septa. The present study adopts an orthogonal design. The design involved irradiation with UV at a UV/DOC ratio of 0.5–3.0 and incubating (headspace-free storage for 5–25 sec. A 1 mM phosphate buffer maintained the pH at 6, 7, or 8 respectively, and an incubator maintained the temperature (Temp at 15, 20, or 25 °C respectively. The development of empirical models for DBPs formation used a multivariate regression procedure (stepwise which applied the SPSS System for Windows (Version 16.0. Results:  The results showed that the total DBPs formation ranged between 12.3 and 67.4 mg/l and that control of the levels was primarily due to the reaction time and the dissolved organic carbon level (DOC in the water. Conclusions:  Reaction time and level of DOC concentrations in water exerted a dominant influence on the formation of DBPs during the UV irradiation of water from the Tajan River. The relationships between the measured and predicted values were satisfactory with R 2 values ranging from 0.89 (for Octanal–0.92 (for Formaldehydes. The DOC level in water is the key factor in controlling DBPs formation.

  18. Similarities in the induction of synthesis of a cell-surface polypeptide in Arthrobacter sp. by near-UV irradiation and photodynamic conditions

    International Nuclear Information System (INIS)

    Hoober, J.K.; Franzi, J.

    1983-01-01

    Irradiation of aerobic suspensions of Arthrobacter sp. with near-UV light (310-400 nm) induced synthesis of a 21 000 dalton, cell-surface polypeptide. Synthesis of this polypeptide also was induced by visible light in the presence of photodynamic dyes. Induction of the polypeptide in ear-UV light and with visible light plus dyes was inhibited by histidine. Hemin inhibited induction in near-UV light and in visible light with methylene blue, neutral red and acriflavin, which are cationic dyes, but failed to inhibit induction in visible light with rose bengal, an anionic dye. These results suggested that inhibition by hemin required electrostatically favored interaction between the anionic porphyrin and the sensitizer, and that the near-UV light effect was mediated by a cationic or neutral endogenous sensitizer. The similarities in the responses of the cells to near-UV irradiation and visible light plus dyes suggested that the mechanism of induction under the two conditions was the same. (author)

  19. Research on photocatalytic H{sub 2} production from acetic acid solution by Pt/TiO{sub 2} nanoparticles under UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Xian-Jun; Zhang, Zhi-Hong; Jiang, Qiao-Juan; Wei, Yong-Jie; Wei, Ming-Bao [Laboratory of Clean Energy, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002 (China); Wei, Li-Fang; Xie, Bing [Henan Provincial Key Laboratory of Surface and Intersurface Science, Zhengzhou University of Light Industry, Zhengzhou 450002 (China)

    2009-11-15

    The Pt/TiO{sub 2} particles have been prepared by the photodeposition of Pt on TiO{sub 2} surface and characterized by X-ray diffraction. Photocatalytic H{sub 2} production from acetic acid (HAc) over Pt/TiO{sub 2} in aqueous solution has been studied at ambient temperature under UV irradiation. The effects of operational variables such as Pt loading, photocatalyst concentration, HAc concentration, and solution pH, have been systematically investigated. The optimum conditions for H{sub 2} production from HAc by Pt/TiO{sub 2} were Pt loading 1.0 wt.%, Pt/TiO{sub 2} concentration 0.22 g/L, HAc concentration 6.52 g/L and pH 1.0. The H{sub 2} yield is 0.27 mol-H{sub 2}/mol-HAc obtained under prolonged time irradiation. Experimental results showed that the photocatalytic H{sub 2} production activity could be enhanced remarkably by depositing a suitable amount Pt on TiO{sub 2} surface. Based on our results, a new process for H{sub 2} production from biomass can be achieved by coupling fermentative H{sub 2} production with photocatalytic H{sub 2} production. The process also provides a method for degradation of organic pollutants with simultaneous H{sub 2} production. A possible mechanism for photocatalytic decomposition of HAc over Pt/TiO{sub 2} was also proposed. (author)

  20. Photocatalytic H{sub 2} production from acetic acid solution over CuO/SnO{sub 2} nanocomposites under UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Xian-Jun; Wei, Yong-Jie; Wei, Ming-Bao [Laboratory of Clean Energy, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002 (China); Wei, Li-Fang; Xie, Bing [Henan Provincial Key Laboratory of Surface and Intersurface Science, Zhengzhou University of Light Industry, Zhengzhou 450002 (China)

    2010-11-15

    The CuO/SnO{sub 2} composites have been prepared by the simple co-precipitation method and further characterized by the XRD, FESEM and Raman spectroscopy. The photocatalytic H{sub 2} production from acetic acid (HAc) solution over CuO/SnO{sub 2} photocatalyst has been investigated at room temperature under UV irradiation. Effects of CuO loading, photocatalyst concentration, acetic acid concentration and pH on H{sub 2} production have been systematically studied. Compared with pure SnO{sub 2}, the 33.3 mol%CuO/SnO{sub 2} composite exhibited approximately twentyfold enhancement of H{sub 2} production. The H{sub 2} yield is about 0.66 mol-H{sub 2}/mol-HAc obtained under irradiation for prolonged time. The Langmuir-type model is applied to study the dependence of hydrogen production rate on HAc concentration. A possible mechanism for photocatalytic degradation of acetic acid over CuO/SnO{sub 2} photocatalyst is proposed as well. Our results provide a method for pollutants removal with simultaneous hydrogen generation. Due to simple preparation, high H{sub 2} production activity and low cost, the CuO/SnO{sub 2} photocatalyst will find wide application in the coming future of hydrogen economy. (author)

  1. Identification of a large genomic region in UV-irradiated human cells which has fewer cyclobutane pyrimidine dimers than most genomic regions

    Energy Technology Data Exchange (ETDEWEB)

    Kantor, G.J.; Deiss-Tolbert, D.M. [Wright State Univ., Dayton, OH (United States)

    1995-08-01

    Size separation after UV-endonuclease digestion of DNA from UV-irradiated human cells using denaturing conditions fractionates the genome based on cyclobutane pyrimidine dimer content. We have examined the largest molecules available (50-80 kb; about 5% of the DNA) after fractionation and those of average size (5-15 kb) for content of some specific genes. We find that the largest molecules are not a representative sampling of the genome. Three contiguous genes located in a G+C-rich isochore (tyrosine hydroxylase, insulin, insulin-like growth factor II) have concentrations two to three times greater in the largest molecules. This shows that this genomic region has fewer pyrimidine dimers than most other genomic regions. In contrast, the {beta}-actin genomic region, which has a similar G+C content, has an equal concentration in both fractions as do the p53 and {beta}-globin genomic regions, which are A+T-rich. These data show that DNA damage in the form of cyclobutane pyrimidine dimers occurs with different probabilities in specific isochores. Part of the reason may be the relative G-C content, but other factors must play a significant role. We also report that the transcriptionally inactive insulin region is repaired at the genome-overall rate in normal cells and is not repaired in xeroderma pigmentosum complementation group C cells. (author).

  2. FACTORS INFLUENCING THE PHOTOCATALYTIC DECOLORIZATION OF METHYLENE BLUE IN THE PRESENCE OF NATURAL IRON OXIDE AND OXALIC ACID UNDER UV IRRADIATION.

    Directory of Open Access Journals (Sweden)

    K BENHAMOUDA

    2014-06-01

    Full Text Available In this work, the methylene blue (MB heterogeneous photodegradation was investigated in the natural iron oxide (NIO and oxalic acid process under UV irradiation. The adsorption of MB onto the surface of NIO was found favorable by the Langmuir approach. Under the operating conditions of this study, the photo-Fenton reaction was set up in co-presence of NIO and Oxalic Acid (OA. Where, the total degradation of MB was achieved in 90 min. The mechanism of MB photodegradation was discussed and the use of 2.0 % of tertiobutanol as a scavenger of •OH confirmed their intervention in the reaction. The effect of oxygen and hydrogen peroxide were investigated, the results demonstrated that the oxygen was necessary in the MB photodegradation and that the optimum concentration of hydrogen peroxide was found to be 5x10-4 M. measuring the chemical oxygen demand (COD demonstrates the effectiveness of our natural iron oxide in the degradation of organic pollutants.

  3. Photocatalytic degradation of p-chlorophenol by hybrid H₂O₂ and TiO₂ in aqueous suspensions under UV irradiation.

    Science.gov (United States)

    Nguyen, Anh Thu; Juang, Ruey-Shin

    2015-01-01

    In this study, TiO2 particles were used as photocatalysts for the degradation of aqueous p-chlorophenol (p-CP) under UV irradiation. The effect of TiO2 dose (0-3 g/L), initial p-CP concentration, H2O2 concentration (2-45 mM), solution pH (4.6-9.5), and UV light intensity on the degradation of p-CP were examined. Four oxidative degradation processes, which utilized UV alone (direct photolysis), H2O2/UV, TiO2/UV, and H2O2/TiO2/UV, were compared in a batch photoreactor with a 100-W high-pressure mercury lamp. The photodegradation of p-CP could be described by the pseudo-first-order kinetics according to the Langmuir-Hinshelwood model. Moreover, the apparent degradation rate constants increased considerably from 3.5 × 10(-)(3) min(-)(1) (direct photolysis) to 19.9 × 10(-)(3) min(-)(1) (H2O2/TiO2/UV system). Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Characteristics of sucrose formation, and the influence of UV irradiation on the feeding by the silkworm, in leaves of the mulberry

    International Nuclear Information System (INIS)

    Yazawa, M.

    1997-01-01

    The mode of formation of sucrose, which is not only a nutritional material but also a phagostimulant for larvae of Bombyx mori, was investigated by measuring the rates of photosynthesis and carbon dioxide fixation in mulberry leaves. Also examined was the influence of UV irradiation to mulberry leaves on the feeding by larvae, as an increase in total amounts of UV rays arriving the surface of the earth due to the destruction of ozone layer has recently led to a global issue. Using mesophyll cells isolated from mulberry leaves, the photosynthetic rate was determined by the oxygen electrode method, and the pathway of carbon dioxide fixation was analyzed by the incorporation of radioactive precursors. In comparison with Ichinose, a popular Japanese race of mulberry, Thailand races investigated were found to be peculiar in that their photosynthetic activities were lower and the photorespiration (glycolic acid cycle) activities were higher, although the synthetic rate of sucrose and its content were much higher than those of Ichinose. It is thus likely that the photorespiration pathway is more important to the sucrose formation in the Thailand races than in Ichinose. In addition, the temperatures during cultivation of mulberry trees was found to influence the relative contributions of photosynthesis and photorespiration to the sucrose formation

  5. The influence of the UV irradiation intensity on photocatalytic activity of ZnAl layered double hydroxides and derived mixed oxides

    Directory of Open Access Journals (Sweden)

    Hadnađev-Kostić Milica S.

    2012-01-01

    Full Text Available Layered double hydroxides (LDHs have been studied to a great extent as environmental-friendly complex materials that can be used as photocatalysts or photocatalyst supports. ZnAl layered double hydroxides and their derived mixed oxides were chosen for the investigation of photocatalytic performances in correlation with the UV intensities measured in the South Pannonia region. Low supersaturation coprecipitation method was used for the ZnAl LDH synthesis. For the characterization of LDH and thermal treated samples powder X-ray diffraction (XRD, scanning electron microscopy (SEM, electron dispersive spectroscopy (EDS, nitrogen adsorption-desorption were used. The decomposition of azodye, methylene blue was chosen as photocatalytic test reaction. The study showed that the ZnAl mixed oxide obtained by thermal decomposition of ZnAl LDH has stable activity in the broader UV light irradiation range characterizing the selected region. Photocatalytic activity could be mainly attributed to the ZnO phase, detected both in LDH and thermally treated samples. The study showed that the ZnAl mixed oxide obtained by the calcination of ZnAl LDH has a stable activity within the measured UV light irradiation range; whereas the parent ZnAl LDH catalyst did not perform satisfactory when low UV irradiation intensity is implied.

  6. Comparison of UV irradiances from Aura/Ozone Monitoring Instrument (OMI) with Brewer measurements at El Arenosillo (Spain) - Part 2: Analysis of site aerosol influence

    Science.gov (United States)

    Cachorro, V. E.; Toledano, C.; Antón, M.; Berjón, A.; de Frutos, A.; Vilaplana, J. M.; Arola, A.; Krotkov, N. A.

    2010-12-01

    Several validation studies have shown a notable overestimation of the clear sky ultraviolet (UV) irradiance at the Earth's surface derived from satellite sensors such as the Total Ozone Mapping Spectrometer (TOMS) and the Ozone Monitoring Instrument (OMI) with respect to ground-based UV data at many locations. Most of this positive bias is attributed to boundary layer aerosol absorption that is not accounted for in the TOMS/OMI operational UV algorithm. Therefore, the main objective of this study is to analyse the aerosol effect on the bias between OMI erythemal UV irradiance (UVER) and spectral UV (305 nm, 310 nm and 324 nm) surface irradiances and ground-based Brewer spectroradiometer measurements from October 2004 to December 2008 at El Arenosillo station (37.1° N, 6.7° W, 20 m a.s.l.), with meteorological conditions representative of the South-West of Spain. The effects of other factors as clouds, ozone and the solar elevation over this intercomparison were analysed in detail in a companion paper (Antón et al., 2010). In that paper the aerosol effects were studied making only a rough evaluation based on aerosol optical depth (AOD) information at 440 nm wavelength (visible range) without applying any correction. We have used the precise information given by single scattering albedo (SSA) from AERONET for the determination of absorbing aerosols which has allowed the correction of the OMI UV data. An aerosol correction expression was applied to the OMI operational UV data using two approaches to estimate the UV absorption aerosol optical depth, AAOD. The first approach was based on an assumption of constant SSA value of 0.91. This approach reduces the OMI UVER bias against the reference Brewer data from 13.4% to 8.4%. Second approach uses daily AERONET SSA values reducing the bias only to 11.6%. Therefore we have obtained a 37% and 12% of improvement respectively. For the spectral irradiance at 324 nm, the OMI bias is reduced from 10.5% to 6.98% for constant

  7. Photocatalytic activity of ZnO doped with Ag on the degradation of endocrine disrupting under UV irradiation and the investigation of its antibacterial activity

    Science.gov (United States)

    Bechambi, Olfa; Chalbi, Manel; Najjar, Wahiba; Sayadi, Sami

    2015-08-01

    Ag-doped ZnO photocatalysts with different Ag molar content (0.0, 0.5, 1.0, 2.0 and 4.0%) were prepared via hydrothermal method. The X-ray diffraction (XRD), Nitrogen physisorption at 77 K, Fourier transformed infrared spectroscopy (FTIR), UV--Visible spectroscopy, Photoluminescence spectra (PL) and Raman spectroscopy were used to characterize the structural, textural and optical properties of the samples. The results showed that Ag-doping does not change the average crystallite size with the Ag low content (≤1.0%) but slightly decreases with Ag high content (>1.0%). The specific surface area (SBET) increases with the increase of the Ag content. The band gap values of ZnO are decreased with the increase of the Ag doping level. The results of the photocatalytic degradation of bisphenol A (BPA) and nonylphenol (NP) in aqueous solutions under UV irradiation and in the presence of hydrogen peroxide (H2O2) showed that silver ions doping greatly improved the photocatalytic efficiency of ZnO. The TOC conversion BPA and NP are 72.1% and 81.08% respectively obtained using 1% Ag-doped ZnO. The enhancement of photocatalytic activity is ascribed to the fact that the modification of ZnO with an appropriate amount of Ag can increase the separation efficiency of the photogenerated electrons-holes in ZnO. The antibacterial activity of the catalysts which uses Escherichia coli as a model for Gram-negative bacteria confirmed that Ag-doped ZnO possessed more antibacterial activity than the pure ZnO.

  8. Transcription factor VdCmr1 is required for pigment production, protection from UV irradiation, and regulates expression of melanin biosynthetic genes in Verticillium dahliae.

    Science.gov (United States)

    Wang, Yonglin; Hu, Xiaoping; Fang, Yulin; Anchieta, Amy; Goldman, Polly H; Hernandez, Gustavo; Klosterman, Steven J

    2018-04-01

    Verticillium dahliae is a soilborne fungus that causes vascular wilt diseases on numerous plant species worldwide. The production of darkly melanized microsclerotia is crucial in the disease cycle of V. dahliae, as these structures allow for long-term survival in soil. Previously, transcriptomic and genomic analysis identified a cluster of genes in V. dahliae that encodes some dihydroxynaphthalene (DHN) melanin biosynthetic pathway homologues found in related fungi. In this study, we explored the roles of cluster-specific transcription factor VdCmr1, as well as two other genes within the cluster encoding a polyketide synthase (VdPKS1) and a laccase (VdLac1), enzymes at initial and endpoint steps in DHN melanin production. The results revealed that VdCmr1 and VdPKS1 are required for melanin production, but neither is required for microsclerotia production. None of the three genes were required for pathogenesis on tobacco and lettuce. Exposure of ΔVdCmr1 and wild-type strains to UV irradiation, or to high temperature (40 °C), revealed an approx. 50 % reduction of survival in the ΔVdCmr1 strain, relative to the wild-type strain, in response to either condition. Expression profiles revealed that expression of some melanin biosynthetic genes are in part dependent on VdCmr1. Combined data indicate VdCmr1 is a key regulator of melanin biosynthesis, and that via regulation of melanogenesis, VdCmr1 affects survival of V. dahliae in response to abiotic threats. We conclude with a model showing regulation of VdCmr1 by a high osmolarity glycerol response (Hog)-type MAP kinase pathway.

  9. Methods for air cleaning and protection of building occupants from airborne pathogens

    DEFF Research Database (Denmark)

    Bolashikov, Zhecho Dimitrov; Melikov, Arsen Krikor

    2009-01-01

    This article aims to draw the attention of the scientific community towards the elevated risks of airborne transmission of diseases and the associated risks of epidemics or pandemics. The complexity of the problem and the need for multidisciplinary research is highlighted. The airborne route...... germicidal irradiation (UVGI), photocatalytic oxidation (PCO), plasmacluster ions and other technologies for air disinfection and purification from pathogens are analyzed with respect to currently used air distribution principles. The importance of indoor air characteristics, such as temperature, relative...... humidity and velocity for the efficiency of each method is analyzed, taking into consideration the nature of the pathogens themselves. The applicability of the methods to the different types of total volume air distribution used at present indoors, i.e. mixing, displacement and underfloor ventilation...

  10. Photocatalytic activity of ZnO doped with Ag on the degradation of endocrine disrupting under UV irradiation and the investigation of its antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Bechambi, Olfa [Université de Tunis El Manar, Faculté des Sciences de Tunis, Laboratoire de Chimie des Matériaux et Catalyse, 2092, Tunis (Tunisia); Chalbi, Manel [Laboratoire de Bioprocédés Environnementaux, Centre de Biotechnologie de Sfax, B.P. 1177, 3018 Sfax (Tunisia); Najjar, Wahiba, E-mail: najjarwahiba2014@gmail.com [Université de Tunis El Manar, Faculté des Sciences de Tunis, Laboratoire de Chimie des Matériaux et Catalyse, 2092, Tunis (Tunisia); Sayadi, Sami [Laboratoire de Bioprocédés Environnementaux, Centre de Biotechnologie de Sfax, B.P. 1177, 3018 Sfax (Tunisia)

    2015-08-30

    Graphical abstract: - Highlights: • A series of Ag-doped ZnO were synthesized via hydrothermal method. • Effect of doping with silver on the textural, structural optical properties of ZnO. • The photocatalytic activity has been tested using bisphenol A and nonylphenol. • The highest degradation efficiency was obtained with 1% Ag. • Ag doping enhances the photocatalytic and antibacterial activities of ZnO. - Abstract: Ag-doped ZnO photocatalysts with different Ag molar content (0.0, 0.5, 1.0, 2.0 and 4.0%) were prepared via hydrothermal method. The X-ray diffraction (XRD), Nitrogen physisorption at 77 K, Fourier transformed infrared spectroscopy (FTIR), UV–-Visible spectroscopy, Photoluminescence spectra (PL) and Raman spectroscopy were used to characterize the structural, textural and optical properties of the samples. The results showed that Ag-doping does not change the average crystallite size with the Ag low content (≤1.0%) but slightly decreases with Ag high content (>1.0%). The specific surface area (S{sub BET}) increases with the increase of the Ag content. The band gap values of ZnO are decreased with the increase of the Ag doping level. The results of the photocatalytic degradation of bisphenol A (BPA) and nonylphenol (NP) in aqueous solutions under UV irradiation and in the presence of hydrogen peroxide (H{sub 2}O{sub 2}) showed that silver ions doping greatly improved the photocatalytic efficiency of ZnO. The TOC conversion BPA and NP are 72.1% and 81.08% respectively obtained using 1% Ag-doped ZnO. The enhancement of photocatalytic activity is ascribed to the fact that the modification of ZnO with an appropriate amount of Ag can increase the separation efficiency of the photogenerated electrons-holes in ZnO. The antibacterial activity of the catalysts which uses Escherichia coli as a model for Gram-negative bacteria confirmed that Ag-doped ZnO possessed more antibacterial activity than the pure ZnO.

  11. In Situ Synthesis of Poly(methyl methacrylate/SiO2 Hybrid Nanocomposites via “Grafting Onto” Strategy Based on UV Irradiation in the Presence of Iron Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Hong Zhang

    2012-01-01

    Full Text Available Poly(methyl methacrylate/SiO2 (PMMA/SiO2 hybrid composites were prepared via “grafting onto” strategy based on UV irradiation in the presence of iron aqueous solution. Two steps were used to graft polymethyl methacrylate (PMMA onto the surface of nanosilica, anchoring 3-(methacryloxy propyl trimethoxysilane (MPTS onto the surface of nanosilica to modify it with double bonds, and then grafting PMMA onto the surface of nanosilica with FeCl3 as photoinitiator. The products were characterized by FT-IR, TGA, TEM, DLS, and XPS. The results showed that it is easy to graft PMMA onto the surface of nanosilica under UV irradiation, and the hybrid particles are monodisperse and have core-shell structure with nanosilica as the core and PMMA layers as the shell. Furthermore, the products initiated by FeCl3 have higher monomer conversion, percent grafting, and better monodispersion compared with the products initiated by traditional photoinitiator such as 2-hydroxy-4-(2-hydroxyethoxy-2-methyl-propiophenone (Irgacure 2959.

  12. Indoor environmental control of tuberculosis and other airborne infections.

    Science.gov (United States)

    Nardell, E A

    2016-02-01

    Tuberculosis (TB) remains the airborne infection of global importance, although many environmental interventions to control TB apply to influenza and other infections with airborne potential. This review focuses on the global problem and the current state of available environmental interventions. TB transmission is facilitated in overcrowded, poorly ventilated congregate settings, such as hospitals, clinics, prisons, jails, and refugee camps. The best means of TB transmission control is source control- to identify unsuspected infectious cases and to promptly begin effective therapy. However, even with active case finding and rapid diagnostics, not every unsuspected case will be identified, and environmental control measures remain the next intervention of choice. Natural ventilation is the main means of air disinfection and has the advantage of wide availability, low cost, and high efficacy-under optimal conditions. It is usually not applicable all year in colder climates and may not be effective when windows are closed on cold nights in warm climates, for security, and for pest control. In warm climates, windows may be closed when air conditioning is installed for thermal comfort. Although mechanical ventilation, if properly installed and maintained, can provide adequate air disinfection, it is expensive to install, maintain, and operate. The most cost-effective way to achieve high levels of air disinfection is upper room germicidal irradiation. The safe and effective application of this poorly defined intervention is now well understood, and recently published evidence-based application guidelines will make implementation easier. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Novel magnetic-fluorescent CS-Fe{sub 3}O{sub 4}@ZnS:Mn/ZnS (core/shell) nanoparticles: Preparation, characterization and damage to bovine serum albumin under UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Li, E-mail: liuli5058@yahoo.cn; Xiao, Ling, E-mail: 775706196@qq.com; Cao, Chunhua

    2013-07-15

    Novel magnetic-fluorescent nanoparticles (CS-Fe{sub 3}O{sub 4}@ZnS:Mn/ZnS) combined ZnS:Mn/ZnS semiconductor nanoparticles and Fe{sub 3}O{sub 4} magnetic nanoparticles with chitosan (CS) matrix were prepared and characterized. Characterization results indicate that CS-Fe{sub 3}O{sub 4}@ZnS:Mn/ZnS (core/shell) nanoparticles show superparamagnetic and strong fluorescent properties. Introduction of ZnS shell significantly enhances the photoluminescence intensity by 3.5 times. The saturation magnetization of CS-Fe{sub 3}O{sub 4}@ZnS:Mn/ZnS nanoparticles was 14.85 emu g{sup −1} at room temperature. The interaction and damage of CS-Fe{sub 3}O{sub 4}@ZnS:Mn/ZnS to bovine serum albumin (BSA) under UV irradiation was investigated by ultraviolet–visible and fluorescence spectra. The results show that electrostatic interaction is the major force for the binding processes of BSA to the surface of CS-Fe{sub 3}O{sub 4}@ZnS:Mn/ZnS. The damage of BSA is prone to happen in the presence of CS-Fe{sub 3}O{sub 4}@ZnS:Mn/ZnS under UV irradiation. CS-Fe{sub 3}O{sub 4}@ZnS:Mn/ZnS may be potential candidate for application as photosensitizers in photodynamic therapy, and fluorescence imaging and magnetic resonance imaging contrast agents for theranostics of cancer. - Highlights: • Novel magnetic-fluorescent CS-Fe{sub 3}O{sub 4}@ZnS:Mn/ZnS nanoparticles were synthesized. • CS-Fe{sub 3}O{sub 4}@ZnS:Mn/ZnS possesses superparamagnetic and bright fluorescent properties. • Introduction of ZnS shell significantly enhances the PL intensity by 3.5 times. • BSA molecule was effectively damaged by CS-Fe{sub 3}O{sub 4}@ZnS:Mn/ZnS under UV irradiation. • Magnetic-fluorescent nanoparticles would be potential agents for cancer treatment.

  14. Resistance to nitrofurantoin and UV-irradiation in recA; uvrA; and uvrA, lexA, Escherichia coli mutants conferred by an R-plasmid from an Escherichia coli clinical isolate

    International Nuclear Information System (INIS)

    Obaseiki-Ebor, E.E.

    1984-01-01

    There have been some reports of R-plasmids conferring nitrofuran resistance by decreasing the reduction of nitrofurantoin. The mechanism by which these R-plasmids mediate nitrofurantoin resistance is still not properly understood. Since DNA repair mutants are very sensitive to nitrofurantoin, it was therefore of interest to see whether R-plasmids conferring nitrofurantoin resistance affected the nitrofurantoin sensitivity of recA; uvrA and uvrA, lexA strains of E. coli K-12. Protection against UV-irradiation was also estimated. The experiments showed that the nitrofurantoin resistance conferred by R-plasmid pBN105 was not due to defective nitrofurantoin reduction or altered permeability of the cell. Because it is known that repair-deficient bacteria have increased susceptibility to nitrofurantoin, it may be suggested that the mechanisms of UV and nitrofurantoin protection conferred by pBN105 to the DNA repair mutant strains are related. (Auth.)

  15. Optical Airborne Tracker System

    Data.gov (United States)

    National Aeronautics and Space Administration — The Optical Airborne Tracker System (OATS) is an airborne dual-axis optical tracking system capable of pointing at any sky location or ground target.  The objectives...

  16. Feasibility of Silver Doped TiO2/Glass Fiber Photocatalyst under Visible Irradiation as an Indoor Air Germicide

    Directory of Open Access Journals (Sweden)

    Thanh-Dong Pham

    2014-03-01

    Full Text Available This study investigated the feasibility of using Ag-TiO2 photocatalyst supported on glass fiber (Ag-TiO2/GF prepared by a sol-gel method as an indoor air germicide. An experimental model was designed to investigate the bacterial disinfection efficiency of Staphylococcus (Staph, the most popular bacterium in hospitals in Korea, by the Ag-TiO2/GF photocatalyst. The silver content in Ag/TiO2 was altered from 1 to 10% to investigate the optimal ratio of Ag doped on TiO2/glass fiber (TiO2/GF for photocatalytic disinfection of Staph. This study confirmed that Ag in Ag-TiO2/GF could work as an electron sink or donor to increase photocatalytic activity and promote the charge separation of electron-hole pairs generated from TiO2 after photon absorption. Ag also acts as an intermediate agent for the transfer of photo-generated electrons from the valence band of TiO2 to an acceptor (O2 gas to promote photo-oxidation processes. The photocatalytic disinfection activity of Ag-TiO2/GF under visible light increased with the increase in silver content up to 7.5% and then slightly decreased with further increasing silver content. The highest disinfection efficiency and disinfection capacity of Staph using 7.5% Ag-TiO2/GF were 75.23% and 20 (CFU∙s−1∙cm−2 respectively. The medium level of humidity of 60% ± 5% showed better photocatalytic disinfection than the lower (40% ± 5% or higher (80% ± 5% levels.

  17. Ultraviolet (UV)-reflective paint with ultraviolet germicidal irradiation (UVGI) improves decontamination of nosocomial bacteria on hospital room surfaces.

    Science.gov (United States)

    Jelden, Katelyn C; Gibbs, Shawn G; Smith, Philip W; Hewlett, Angela L; Iwen, Peter C; Schmid, Kendra K; Lowe, John J

    2017-06-01

    An ultraviolet germicidal irradiation (UVGI) generator (the TORCH, ClorDiSys Solutions, Inc.) was used to compare the disinfection of surface coupons (plastic from a bedrail, stainless steel, and chrome-plated light switch cover) in a hospital room with walls coated with ultraviolet (UV)-reflective paint (Lumacept) or standard paint. Each surface coupon was inoculated with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus faecalis (VRE), placed at 6 different sites within a hospital room coated with UV-reflective paint or standard paint, and treated by 10 min UVC exposure (UVC dose of 0-688 mJ/cm 2 between sites with standard paint and 0-553 mJ/cm 2 with UV-reflective paint) in 8 total trials. Aggregated MRSA concentrations on plastic bedrail surface coupons were reduced on average by 3.0 log 10 (1.8 log 10 Geometric Standard Deviation [GSD]) with standard paint and 4.3 log 10 (1.3 log 10 GSD) with UV-reflective paint (p = 0.0005) with no significant reduction differences between paints on stainless steel and chrome. Average VRE concentrations were reduced by ≥4.9 log 10 (light, MRSA concentrations on average were reduced by 5.2 log 10 (1.4 log 10 GSD) with standard paint and 5.1 log 10 (1.2 log 10 GSD) with UV-reflective paint (p = 0.017) and VRE by 4.4 log 10 (1.4 log 10 GSD) with standard paint and 5.3 log 10 (1.1 log 10 GSD) with UV-reflective paint (p bacteria on various surfaces compared to standard paint, particularly at a surface placement site indirectly exposed to UVC light.

  18. Effect of germicidal UV-C light(254 nm) on eggs and adult of house dustmites, Dermatophagoides pteronyssinus and Dermatophagoides farinae (Astigmata: Pyroglyhidae)

    OpenAIRE

    Lah, Ernieenor Faraliana Che; Musa, Raja Noor Azreen Raja; Ming, Ho Tze

    2012-01-01

    Objective: To examined the immediate and 24 hours post- irradiation germicidal effects of UV-C lamp on eggs and adults of house dust mites Dermatophagoides pteronyssinus (D. pteronyssinus) and Dermatophagoides farinae (D. farinae). Methods: This study investigated the immediate and 24 hours post irradiation mortalities of adult mites exposed to UV-C at different exposure times (5 mins, 10 mins, 15 mins, 20 mins, 30 mins and 60 mins) and distances (10 cm, 25 cm, 35 cm, 45 cm and 55 cm). Fre...

  19. CLPX-Airborne: Airborne GPS Bistatic Radar

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set consists of measurements of GPS signals reflected from the Earth's surface and collected on an airborne platform. A modified GPS Delay Mapping Receiver...

  20. H{sub 2}O{sub 2} and/or TiO{sub 2} photocatalysis under UV irradiation for the removal of antibiotic resistant bacteria and their antibiotic resistance genes

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Changsheng [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Wang, Kai [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Wuxi SensingNet Industrialization Research Institute, Wuxi 214000 (China); Hou, Song; Wan, Li; Lv, Jiapei; Zhang, Yuan [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Qu, Xiaodong [State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, and Department of Water Environment, China Institute of Water Resources and Hydropower Research, Beijing 100038 (China); Chen, Shuyi [Wuxi SensingNet Industrialization Research Institute, Wuxi 214000 (China); Xu, Jian, E-mail: xujian@craes.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China)

    2017-02-05

    Highlights: • TiO{sub 2} thin film was successfully synthesized for treating ARB and ARGs from water. • More than 5.5 log units of ARB reduction was achieved by TiO{sub 2} under UV irradiation. • With TiO{sub 2}, ARGs were reduced by more than 5 log units under UV irradiation. • TiO{sub 2} could remove both intracellular and extracellular forms of ARGs. - Abstract: Inactivating antibiotic resistant bacteria (ARB) and removing antibiotic resistance genes (ARGs) are very important to prevent their spread into the environment. Previous efforts have been taken to eliminate ARB and ARGs from aqueous solution and sludges, however, few satisfying results have been obtained. This study investigated whether photocatalysis by TiO{sub 2} was able to reduce the two ARGs, mecA and ampC, within the host ARB, methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, respectively. The addition of H{sub 2}O{sub 2} and matrix effect on the removal of ARB and ARGs were also studied. TiO{sub 2} thin films showed great effect on both ARB inactivation and ARGs removal. Approximately 4.5-5.0 and 5.5–5.8 log ARB reductions were achieved by TiO{sub 2} under 6 and 12 mJ/cm{sup 2} UV{sub 254} fluence dose, respectively. For ARGs, 5.8 log mecA reduction and 4.7 log ampC reduction were achieved under 120 mJ/cm{sup 2} UV{sub 254} fluence dose in the presence of TiO{sub 2}. Increasing dosage of H{sub 2}O{sub 2} enhanced the removal efficiencies of ARB and ARGs. The results also demonstrated that photocatalysis by TiO{sub 2} was capable of removing both intracellular and extracellular forms of ARGs. This study provided a potential alternative method for the removal of ARB and ARGs from aqueous solution.

  1. Airborne geoid determination

    DEFF Research Database (Denmark)

    Forsberg, René; Olesen, Arne Vestergaard; Bastos, L.

    2000-01-01

    Airborne geoid mapping techniques may provide the opportunity to improve the geoid over vast areas of the Earth, such as polar areas, tropical jungles and mountainous areas, and provide an accurate "seam-less" geoid model across most coastal regions. Determination of the geoid by airborne methods......-suited for geoid determination, with high-frequency survey and downward continuation noise being offset by the low-pass gravity to geoid filtering operation. In the paper the basic principles of airborne geoid determination are outlined, and examples of results of recent airborne gravity and geoid surveys...

  2. Two Different Replication Factor C Proteins, Ctf18 and RFC1, Separately Control PCNA-CRL4Cdt2-Mediated Cdt1 Proteolysis during S Phase and following UV Irradiation

    Science.gov (United States)

    Shiomi, Yasushi; Hayashi, Akiyo; Ishii, Takashi; Shinmyozu, Kaori; Nakayama, Jun-ichi; Sugasawa, Kaoru

    2012-01-01

    Recent work identified the E3 ubiquitin ligase CRL4Cdt2 as mediating the timely degradation of Cdt1 during DNA replication and following DNA damage. In both cases, proliferating cell nuclear antigen (PCNA) loaded on chromatin mediates the CRL4Cdt2-dependent proteolysis of Cdt1. Here, we demonstrate that while replication factor C subunit 1 (RFC1)-RFC is required for Cdt1 degradation after UV irradiation during the nucleotide excision repair process, another RFC complex, Ctf18-RFC, which is known to be involved in the establishment of cohesion, has a key role in Cdt1 degradation in S phase. Cdt1 segments having only the degron, a specific sequence element in target protein for ubiquitination, for CRL4Cdt2 were stabilized during S phase in Ctf18-depleted cells. Additionally, endogenous Cdt1 was stabilized when both Skp2 and Ctf18 were depleted. Since a substantial amount of PCNA was detected on chromatin in Ctf18-depleted cells, Ctf18 is required in addition to loaded PCNA for Cdt1 degradation in S phase. Our data suggest that Ctf18 is involved in recruiting CRL4Cdt2 to PCNA foci during S phase. Ctf18-mediated Cdt1 proteolysis occurs independent of cohesion establishment, and depletion of Ctf18 potentiates rereplication. Our findings indicate that individual RFC complexes differentially control CRL4Cdt2-dependent proteolysis of Cdt1 during DNA replication and repair. PMID:22493068

  3. Airborne geoid determination

    DEFF Research Database (Denmark)

    Forsberg, René; Olesen, Arne Vestergaard; Bastos, L.

    2000-01-01

    Airborne geoid mapping techniques may provide the opportunity to improve the geoid over vast areas of the Earth, such as polar areas, tropical jungles and mountainous areas, and provide an accurate "seam-less" geoid model across most coastal regions. Determination of the geoid by airborne methods...

  4. Methods for air cleaning and protection of building occupants from airborne pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Bolashikov, Z.D.; Melikov, A.K. [International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Nils Koppels Alle, building 402, 2800 Lyngby (Denmark)

    2009-07-15

    This article aims to draw the attention of the scientific community towards the elevated risks of airborne transmission of diseases and the associated risks of epidemics or pandemics. The complexity of the problem and the need for multidisciplinary research is highlighted. The airborne route of transmission, i.e. the generation of pathogen laden droplets originating in the respiratory tract of an infected individual, the survivability of the pathogens, their dispersal indoors and their transfer to a healthy person are reviewed. The advantages and the drawbacks of air dilution, filtration, ultraviolet germicidal irradiation (UVGI), photocatalytic oxidation (PCO), plasmacluster ions and other technologies for air disinfection and purification from pathogens are analyzed with respect to currently used air distribution principles. The importance of indoor air characteristics, such as temperature, relative humidity and velocity for the efficiency of each method is analyzed, taking into consideration the nature of the pathogens themselves. The applicability of the cleaning methods to the different types of total volume air distribution used at present indoors, i.e. mixing, displacement and underfloor ventilation, as well as advanced air distribution techniques (such as personalized ventilation) is discussed. (author)

  5. Influence of melanocytes in the ex-vivo reconstructed epidermal melanin unit following an acute UV irradiation; Role des melanocytes dans l'unite epidermique de melanisation reconstruite ex-vivo apres une irradiation UV aigue

    Energy Technology Data Exchange (ETDEWEB)

    Cario-Andre, M

    2000-11-15

    Influence of melanocytes in skin pigmentation is well documented, however its photo-protective role has given rise to controversy. The role of melanocytes have been investigated on reconstructed epidermis with 100 % of keratinocytes or 95 % of keratinocytes and 5 % of melanocytes. In a first time, the effect of an acute UVB dose has been studied on both reconstructed epidermis, next we have investigated UVA and UVA+B effects on these epidermis. Following irradiation, the presence of melanocytes in reconstructed epidermis protects against apoptosis without protecting significantly against DNA damage formation (CPD, 6-4PP) and protects against UV-induced unbalance of the SOD/catalase ratio (antioxidants enzymes). On the contrary, the presence of melanocytes in reconstructed epidermis amplifies lipids and proteins oxidations but seems to protect against DNA oxidations. Melanocytes differ from keratinocytes by their melanin content and their more important concentration in polyunsaturated fatty acids. To evaluate what is the part of melanin and the part of polyunsaturated fatty acids in epidermal UV responses, reconstructed epidermis with keratinocytes have been supplemented with polyunsaturated fatty acid. This study indicates that polyunsaturated fatty acids are responsible for lipids and proteins oxidations and that melanin protect against DNA oxidation induced by lipid peroxidation. All these studies demonstrate that, model of reconstructed epidermis and epidermis in-vivo have the same behaviour following UV irradiation. In the last part, sunscreens and antioxidants have been tested on reconstructed epidermis and have demonstrated that model of reconstructed epidermis is suitable for photo-protective molecules screening. (author)

  6. Alteration in murine epidermal Langerhans cell population by various UV irradiations: quantitative and morphologic studies on the effects of various wavelengths of monochromatic radiation on Ia-bearing cells

    International Nuclear Information System (INIS)

    Obata, M.; Tagami, H.

    1985-01-01

    The present study was undertaken in order to clarify the exact mode of the Langerhans cell (LC) depleting process caused by UV irradiation. Following irradiation with a single dose of various wavelengths of monochromatic UV radiation (UVR), the number of Ia-positive cells were studied in mouse epidermal sheets quantitatively, particularly with regard to dose-response relationships, action spectrum, and time course change. In addition, morphologic alterations of these cells were studied using electron- and immunoelectron microscopy (EM and IEM). The authors obtained the following results after a single dose of UVB radiation (200 mJ/cm2 of 300 nm) or PUVA (1% of 8-methoxypsoralen (8-MOP) 20 microliter and 1 J/cm2 of 360 nm): (1) EM and IEM showed that while some LCs simply lost their Ia marker without any structural alterations, the majority of the LCs disappeared due to actual cell damage. (2) During an ''injury phase,'' the initial 48 h, and a ''recovery phase,'' lasting from 4-14 days after irradiation, enlargement of the size of remaining Ia-positive LCs occurred. The degree of enlargement was closely related to the degree of reduction in number, suggesting a process compensating for the loss of the LC population. (3) It was found that the recovery rate of LCs after irradiation damage was slower than that of keratinocytes, indicating different cell kinetics between these distinct cell populations in the epidermis, i.e., restoration of LCs after irradiation seems to be achieved at least partially through a repopulation process originating in the bone marrow

  7. Airborne Power Supply Unit

    Data.gov (United States)

    National Aeronautics and Space Administration — The Airborne Power Supply Unit (APSU) is a programmable DC/DC converter that can supply multiple constant voltage or constant current outputs in a small enclosure,...

  8. Airborne Test Bed Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Laboratory operates the main hangar on the Hanscom Air Force Base flight line. This very large building (~93,000sqft) accommodates the Laboratory's airborne test...

  9. Airborne Magnetic Trackline Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA National Centers for Environmental Information (formerly National Geophysical Data Center) receive airborne magnetic survey data from US and non-US...

  10. Waterberg coalfield airborne geophysics

    CSIR Research Space (South Africa)

    Fourie, S

    2009-07-01

    Full Text Available Airborne Geophysics Project Number: 1.5.5 Sub Committee: Geology and Geophysics Presenter: Dr. Stoffel Fourie Co-Workers: Dr. George Henry & Me. Leonie Marè Collaborators: Coaltech & CSIR Project Objectives Major Objectives: circle5 Initiate Semi...-Regional Exploration of the Waterberg Coalfield to the benefit of the Industry. circle5 Generate a good quality Airborne Geophysical Dataset. circle5 Generate a basic lineament and surface geology interpretation of the Ellisras Basin. circle5 Generate a basic...

  11. 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.

  12. Thermoluminescence sensitivity of ulexite after UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Topaksu, M., E-mail: mats@cu.edu.tr [Cukurova University, Arts-Sciences Faculty, Physics Department, 01330 Adana (Turkey); CIEMAT, Av. Complutense 22, 28040 Madrid (Spain); Correcher, V. [CIEMAT, Av. Complutense 22, 28040 Madrid (Spain); Garcia-Guinea, J. [Museo Nacional de Ciencias Naturales, (CSIC), C/José Gutiérrez Abascal 2, 28006 Madrid (Spain)

    2015-04-15

    Highlights: •UV-induced thermoluminescence emission of Turkish ulexite was studied. •There are three groups of components. •The UV exposures were performed at controlled temperatures. -- Abstract: The effects of UV radiation on the thermoluminescence (TL) properties of natural materials, in contrast to synthetic materials, have been scarcely studied. We report on the UV-induced thermoluminescence emission of a Turkish ulexite (NaCaB{sub 5}O{sub 6}(OH){sub 6}·5H{sub 2}O) that displays very complex TL glow curves, with at least three groups of components peaked at 130–140 °C, 240 °C and, 340 °C, wherein the last group is weaker. Such emission could be associated with structural changes in the lattice as well as alkali self-diffusion processes. The UV exposure performed at controlled temperatures (at room temperature (RT), 50 °C and 100 °C) produced a (i) different evolutions of the intensities of each maximum, which are directly related to the controlled thermal treatment; (ii) different intensity ratios among the groups of components; (iii) different activation energies (E{sub a}) (1.13 eV for RT, 0.99 eV for 50 °C and 0.49 eV for 100 °C) calculated using the initial rise method; and (iv) similar scattering values (12.4%, 8.2% and 12.8%), which were not a function of the controlled temperature. The thermal stability tests conducted on this borate at different temperatures, based on the T{sub stop} protocol, confirm the presence of a continuum in the distribution of the trap system with progressively increasing E{sub a} (from 0.60 to 0.90 eV)

  13. Quantification of biologically effective environmental UV irradiance

    Science.gov (United States)

    Horneck, G.

    To determine the impact of environmental UV radiation on human health and ecosystems demands monitoring systems that weight the spectral irradiance according to the biological responses under consideration. In general, there are three different approaches to quantify a biologically effective solar irradiance: (i) weighted spectroradiometry where the biologically weighted radiometric quantities are derived from spectral data by multiplication with an action spectrum of a relevant photobiological reaction, e.g. erythema, DNA damage, skin cancer, reduced productivity of terrestrial plants and aquatic foodweb; (ii) wavelength integrating chemical-based or physical dosimetric systems with spectral sensitivities similar to a biological response curve; and (iii) biological dosimeters that directly weight the incident UV components of sunlight in relation to the effectiveness of the different wavelengths and to interactions between them. Most biological dosimeters, such as bacteria, bacteriophages, or biomolecules, are based on the UV sensitivity of DNA. If precisely characterized, biological dosimeters are applicable as field and personal dosimeters.

  14. Mammalian airborne allergens

    NARCIS (Netherlands)

    Aalberse, Rob C.

    2014-01-01

    Historically, horse dandruff was a favorite allergen source material. Today, however, allergic symptoms due to airborne mammalian allergens are mostly a result of indoor exposure, be it at home, at work or even at school. The relevance of mammalian allergens in relation to the allergenic activity of

  15. Airborne Power Supply Study,

    Science.gov (United States)

    The airborne power supply study considers the conversion of 400 cycle aircraft power to regulated DC voltages. Topics include the review of present...power conversion techniques, monolithic IC and hybrid series voltage regulators, power supply problem areas, trade-off considerations and power system

  16. Effect of germicidal UV-C light(254 nm) on eggs and adult of house dustmites, Dermatophagoides pteronyssinus and Dermatophagoides farinae (Astigmata: Pyroglyhidae).

    Science.gov (United States)

    Lah, Ernieenor Faraliana Che; Musa, Raja Noor Azreen Raja; Ming, Ho Tze

    2012-09-01

    To examined the immediate and 24 hours post- irradiation germicidal effects of UV-C lamp on eggs and adults of house dust mites Dermatophagoides pteronyssinus (D. pteronyssinus) and Dermatophagoides farinae (D. farinae). This study investigated the immediate and 24 hours post irradiation mortalities of adult mites exposed to UV-C at different exposure times (5 mins, 10 mins, 15 mins, 20 mins, 30 mins and 60 mins) and distances (10 cm, 25 cm, 35 cm, 45 cm and 55 cm). Fresh eggs of the 2 dust mites were also irradiated at 10, 35 and 55 cm for 0.5, 1, 2, 3, and 5 minutes, and observed daily post- irradiation for up to 7 days. Highest immediate mortality of 100% occurred with direct irradiation at 10 cm distance from UV-C lamp and for 60 mins, for both species of mites. The post 24 hours mean mortality rates were (58.4±17.4)% for D. pteronyssinus and (27.7±9.7)% for D. farinae when irradiated for 1 hour at 55 cm distance under UV-C lamp. When mites were irradiated in the presence of culture media, the highest mortality rates were lower compared to the direct irradiation; at 10 cm distance and 60 mins exposure, the mean mortality was (74.0±6.8)% for D. pteronyssinus and (70.3±6.7)% for D. farinae. Egg hatchability for both species of mites was also notably reduced by greater than 50% following irradiation. Ultraviolet C irradiation is lethal to an array of organisms by damaging their nucleic acids (DNA and RNA). This study demonstrates the increasing mite mortalities with increasing exposure times and decreasing distances.

  17. The airborne supercomputer

    Science.gov (United States)

    Rhea, John

    1990-05-01

    A new class of airborne supercomputer designated RH-32 is being developed at USAF research facilities, capable of performing the critical battle management function for any future antiballistic missile system that emerges from the SDI. This research is also aimed at applications for future tactical aircraft and retrofit into the supercomputers of the ATF. The computers are based on a system architecture known as multi-interlock pipe stages, developed by the DARPA. Fiber-optic data buses appear to be the only communications media that are likely to match the speed of the processors and they have the added advantage of being inherently radiation resistant. The RH-32 itself, being the product of a basic research effort, may never see operational use. However, the technologies that emerge from this major R&D program will set the standards for airborne computers well into the next century.

  18. Airborne wireless communication systems, airborne communication methods, and communication methods

    Science.gov (United States)

    Deaton, Juan D [Menan, ID; Schmitt, Michael J [Idaho Falls, ID; Jones, Warren F [Idaho Falls, ID

    2011-12-13

    An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

  19. Airborne Laser Polarization Sensor

    Science.gov (United States)

    Kalshoven, James, Jr.; Dabney, Philip

    1991-01-01

    Instrument measures polarization characteristics of Earth at three wavelengths. Airborne Laser Polarization Sensor (ALPS) measures optical polarization characteristics of land surface. Designed to be flown at altitudes of approximately 300 m to minimize any polarizing or depolarizing effects of intervening atmosphere and to look along nadir to minimize any effects depending on look angle. Data from measurements used in conjunction with data from ground surveys and aircraft-mounted video recorders to refine mathematical models used in interpretation of higher-altitude polarimetric measurements of reflected sunlight.

  20. Airborne monitoring system

    International Nuclear Information System (INIS)

    Kadmon, Y.; Gabovitch, A.; Tirosh, D.; Ellenbogen, M.; Mazor, T.; Barak, D.

    1997-01-01

    A complete system for tracking, mapping, and performing a composition analysis of a radioactive plume and contaminated area was developed at the NRCN. The system includes two major units : An airborne unit for monitoring and a ground station for analyzing. The airborne unit is mounted on a helicopter and includes file following. Four radiation sensor, two 2'' x 2'' Nal (Tl) sensors horizontally separated by lead shield for mapping and spectroscopy, and two Geiger Mueller (GM) tubes as part of the safety system. A multichannel analyzer card is used for spectroscopy. A navigation system, based on GPS and a barometric altitude meter, is used to locate the plume or ground data. The telemetry system, consisting of a transceiver and a modem, transfers all the data in real time to the ground station. An industrial PC (Field Works) runs a dedicated C++ Windows application to manage the acquired data. An independent microprocessor based backup system includes a recorder, display, and key pad. The ground station is based on an industrial PC, a telemetry system, a color printer and a modem to communicate with automatic meteorology stations in the relevant area. A special software controls the ground station. Measurement results are analyzed in the ground station to estimate plume parameters including motion, location, size, velocity, and perform risk assessment. (authors)

  1. Modeling for Airborne Contamination

    Energy Technology Data Exchange (ETDEWEB)

    F.R. Faillace; Y. Yuan

    2000-08-31

    The objective of Modeling for Airborne Contamination (referred to from now on as ''this report'') is to provide a documented methodology, along with supporting information, for estimating the release, transport, and assessment of dose to workers from airborne radioactive contaminants within the Monitored Geologic Repository (MGR) subsurface during the pre-closure period. Specifically, this report provides engineers and scientists with methodologies for estimating how concentrations of contaminants might be distributed in the air and on the drift surfaces if released from waste packages inside the repository. This report also provides dose conversion factors for inhalation, air submersion, and ground exposure pathways used to derive doses to potentially exposed subsurface workers. The scope of this report is limited to radiological contaminants (particulate, volatile and gaseous) resulting from waste package leaks (if any) and surface contamination and their transport processes. Neutron activation of air, dust in the air and the rock walls of the drift during the preclosure time is not considered within the scope of this report. Any neutrons causing such activation are not themselves considered to be ''contaminants'' released from the waste package. This report: (1) Documents mathematical models and model parameters for evaluating airborne contaminant transport within the MGR subsurface; and (2) Provides tables of dose conversion factors for inhalation, air submersion, and ground exposure pathways for important radionuclides. The dose conversion factors for air submersion and ground exposure pathways are further limited to drift diameters of 7.62 m and 5.5 m, corresponding to the main and emplacement drifts, respectively. If the final repository design significantly deviates from these drift dimensions, the results in this report may require revision. The dose conversion factors are further derived by using concrete of

  2. Airborne Cloud Computing Environment (ACCE)

    Science.gov (United States)

    Hardman, Sean; Freeborn, Dana; Crichton, Dan; Law, Emily; Kay-Im, Liz

    2011-01-01

    Airborne Cloud Computing Environment (ACCE) is JPL's internal investment to improve the return on airborne missions. Improve development performance of the data system. Improve return on the captured science data. The investment is to develop a common science data system capability for airborne instruments that encompasses the end-to-end lifecycle covering planning, provisioning of data system capabilities, and support for scientific analysis in order to improve the quality, cost effectiveness, and capabilities to enable new scientific discovery and research in earth observation.

  3. CLPX Airborne: Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set consists of apparent surface reflectance, subpixel snow-covered area and grain size inferred from data acquired by the Airborne Visible/Infrared...

  4. CLPX-Airborne: Airborne Synthetic Aperture Radar (AIRSAR) Imagery

    Data.gov (United States)

    National Aeronautics and Space Administration — Airborne Synthetic Aperture Radar (AIRSAR) is a side-looking imaging radar that is able to collect data irrespective of daylight or cloud cover. The AIRSAR...

  5. Airborne Particulate Threat Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Patrick Treado; Oksana Klueva; Jeffrey Beckstead

    2008-12-31

    Aerosol threat detection requires the ability to discern between threat agents and ambient background particulate matter (PM) encountered in the environment. To date, Raman imaging technology has been demonstrated as an effective strategy for the assessment of threat agents in the presence of specific, complex backgrounds. Expanding our understanding of the composition of ambient particulate matter background will improve the overall performance of Raman Chemical Imaging (RCI) detection strategies for the autonomous detection of airborne chemical and biological hazards. Improving RCI detection performance is strategic due to its potential to become a widely exploited detection approach by several U.S. government agencies. To improve the understanding of the ambient PM background with subsequent improvement in Raman threat detection capability, ChemImage undertook the Airborne Particulate Threat Assessment (APTA) Project in 2005-2008 through a collaborative effort with the National Energy Technology Laboratory (NETL), under cooperative agreement number DE-FC26-05NT42594. During Phase 1 of the program, a novel PM classification based on molecular composition was developed based on a comprehensive review of the scientific literature. In addition, testing protocols were developed for ambient PM characterization. A signature database was developed based on a variety of microanalytical techniques, including scanning electron microscopy, FT-IR microspectroscopy, optical microscopy, fluorescence and Raman chemical imaging techniques. An automated particle integrated collector and detector (APICD) prototype was developed for automated collection, deposition and detection of biothreat agents in background PM. During Phase 2 of the program, ChemImage continued to refine the understanding of ambient background composition. Additionally, ChemImage enhanced the APICD to provide improved autonomy, sensitivity and specificity. Deliverables included a Final Report detailing our

  6. Karoo airborne geophysical survey

    International Nuclear Information System (INIS)

    Cole, D.J.; Stettler, E.H.

    1984-01-01

    Thirty four uranium anomalies were selected for ground follow-up from the analogue spectrometer records of Block 4 of the Karoo Airborne Geophysical Survey. The anomalies were plotted on 1:50 000 scale topographic maps and to 1:250 000 scale maps which are included in this report. The anomaly co-ordinates are tabulated together with the farms on which they occur. Results of the ground follow-up of the aerial anomalies are described. Twenty two anomalies are related to uranium mineralisation of which seventeen occur over baked mudstone adjacent to a dolerite intrusion. Five are located over fluvial channel sandstone of the Beaufort Group and subsurface mineralised sandstone may be present. The other twelve anomalies are spurious. Of the anomalies located over baked mudstone, fifteen emanate from ferruginous mudstone of the Whitehill Formation west of longitude 21 degrees 15 minutes. One of the two remaining anomalies over baked mudstone occurs over the Prince Albert Formation and the other anomaly is over baked mudstone and calcareous nodules of the Beaufort Group. The general low uranium values (less than 355 ppm eU3O8) render the occurrences uneconomic

  7. GLORIA: an airborne imaging FTS

    Science.gov (United States)

    Sha, Mahesh K.

    2017-11-01

    The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) is an imaging Fourier Transform Spectrometer (FTS) which is capable of operating on various airborne platforms. The main scientific focus is on the dynamics and chemistry of the Upper Troposphere and Lower Stratosphere (UTLS) region.

  8. Airborne gamma-ray spectrometry

    DEFF Research Database (Denmark)

    Hovgaard, Jens

    A new method - Noise Adjusted Singular Value Decomposition, NASVD - for processing gamma-ray spectra has been developed as part of a Ph.D. project. By using this technique one is able to decompose a large set of data - for example from airborne gamma-ray surveys - into a few spectral components. ...

  9. Airborne microorganisms from waste containers.

    Science.gov (United States)

    Jedlicka, Sabrina S; Stravitz, David M; Lyman, Charles E

    2012-01-01

    In physician's offices and biomedical labs, biological waste is handled every day. This waste is disposed of in waste containers designed for holding red autoclave bags. The containers used in these environments are closed hands-free containers, often with a step pedal. While these containers protect the user from surface-borne microorganisms, the containers may allow airborne microorganisms to escape via the open/close mechanism because of the air current produced upon open/close cycles. In this study, the air current was shown to be sufficient to allow airborne escape of microorganisms held in the container, including Aspergillus niger. However, bacterial cultures, such as Escherichia coli and Lactococcus lactis did not escape. This may be due to the choice of bacterial cultures and the absence of solid waste, such as dust or other particulate matter in the waste containers, that such strains of bacteria could travel on during aerosolization. We compared these results to those obtained using a re-designed receptacle, which mimimizes air currents, and detected no escaping microorganisms. This study highlights one potential source of airborne contamination in labs, hospitals, and other environments that dispose of biological waste.

  10. Monitoring and evaluation techniques for airborne contamination

    International Nuclear Information System (INIS)

    Xia Yihua

    1997-01-01

    Monitoring and evaluation of airborne contamination are of great importance for the purpose of protection of health and safety of workers in nuclear installations. Because airborne contamination is one of the key sources to cause exposure to individuals by inhalation and digestion, and to cause diffusion of contaminants in the environment. The main objectives of monitoring and evaluation of airborne contamination are: to detect promptly a loss of control of airborne material, to help identify those individuals and predict exposure levels, to assess the intake and dose commitment to the individuals, and to provide sufficient documentation of airborne radioactivity. From the viewpoint of radiation protection, the radioactive contaminants in air can be classified into the following types: airborne aerosol, gas and noble gas, and volatile gas. In this paper, the following items are described: sampling methods and techniques, measurement and evaluation, and particle size analysis. (G.K.)

  11. Monitoring and evaluation techniques for airborne contamination

    Energy Technology Data Exchange (ETDEWEB)

    Xia Yihua [China Inst. of Atomic Energy, Beijing (China)

    1997-06-01

    Monitoring and evaluation of airborne contamination are of great importance for the purpose of protection of health and safety of workers in nuclear installations. Because airborne contamination is one of the key sources to cause exposure to individuals by inhalation and digestion, and to cause diffusion of contaminants in the environment. The main objectives of monitoring and evaluation of airborne contamination are: to detect promptly a loss of control of airborne material, to help identify those individuals and predict exposure levels, to assess the intake and dose commitment to the individuals, and to provide sufficient documentation of airborne radioactivity. From the viewpoint of radiation protection, the radioactive contaminants in air can be classified into the following types: airborne aerosol, gas and noble gas, and volatile gas. In this paper, the following items are described: sampling methods and techniques, measurement and evaluation, and particle size analysis. (G.K.)

  12. ZPR-9 airborne plutonium monitoring system

    International Nuclear Information System (INIS)

    Rusch, G.K.; McDowell, W.P.; Knapp, W.G.

    1975-01-01

    An airborne plutonium monitoring system which is installed in the ZPR-9 (Zero Power Reactor No. 9) facility at Argonne National Laboratory is described. The design and operational experience are discussed. This monitoring system utilizes particle size and density discrimination, alpha particle energy discrimination, and a background-subtraction techique operating in cascade to separate airborne-plutonium activity from other, naturally occurring, airborne activity. Relatively high sensitivity and reliability are achieved

  13. Electrospray Collection of Airborne Contaminants, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — In stark contrast to current stagnation-based methods for capturing airborne particulates and biological aerosols, our demonstrated, cost-effective electrospray...

  14. Electrospray Collection of Airborne Contaminants, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In stark contrast to current stagnation-based methods for capturing airborne particulates and biological aerosols, our demonstrated, cost-effective electrospray...

  15. Chemical Microsensor Instrument for UAV Airborne Atmospheric Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Makel Engineering, Inc. (MEI) proposes to develop a miniaturized Airborne Chemical Microsensor Instrument (ACMI) suitable for real-time, airborne measurements of...

  16. Source terms for airborne effluents

    International Nuclear Information System (INIS)

    Blomeke, J.O.; Perona, J.J.

    1976-01-01

    The origin and nature of fuel cycle wastes are discussed with regard to high-level wastes, cladding, noble gases, iodine, tritium, 14 C, low-level and intermediate-level transuranic wastes, non-transuranic wastes, and ore tailings. The current practice for gaseous effluent treatment is described for light water reactors and high-temperature gas-cooled reactors. Other topics discussed are projections of nuclear power generation; projected accumulation of gaseous wastes; the impact of nuclear fuel cycle centers; and global buildup of airborne effluents

  17. Compositae dermatitis from airborne parthenolide

    DEFF Research Database (Denmark)

    Paulsen, E; Christensen, Lars Porskjær; Andersen, Klaus Ejner

    2007-01-01

    suspected of causing airborne contact allergy, and its most important allergen is the sesquiterpene lactone (SQL) parthenolide (PHL). OBJECTIVES: The aims of this study were to (i) assess the allergenicity of feverfew-derived monoterpenes and sesquiterpenes and their oxidized products in feverfew......, obtained by fractionation of ether extracts, dynamic headspace and high-volume air sampler (HIVAS) technique, respectively. RESULTS: Among 12 feverfew-allergic patients, eight had positive patch-test reactions to a HIVAS filter extract, while two tested positive to a headspace extract. Subsequent analysis...

  18. Geophex airborne unmanned survey system

    International Nuclear Information System (INIS)

    Won, I.J.; Taylor, D.W.A.

    1995-01-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This nonintrusive system will provide open-quotes stand-offclose quotes capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits two operators to rapidly conduct geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance, of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak anomalies can be detected

  19. Enzymatic repair of uv-irradiated DNA in vitro

    International Nuclear Information System (INIS)

    Hamilton, L.D.; Mahler, I.; Grossman, L.

    1975-01-01

    Excision repair of uv-damaged Bacillus subtilis transforming DNA has been carried out by a sequential enzyme system in vitro. Incision adjacent to the pyrimidine dimer in the DNA strand by correndonuclease II-initiated excision of the damage by the 5' → 3'-directed exonuclease of the Micrococcus luteus DNA polymerase. Reinsertion of nucleotides into the gap in the strand by the DNA polymerase at 10 0 C terminated in a single-strand break which was sealed by a polynucleotide ligase, thereby repairing the DNA strand. This restored biological activity to damaged DNA up to doses resulting in 60 percent inactivation of transforming activity. At higher doses, less repair was achieved, due to the development of double-strand breaks during the in vitro incision and excision steps

  20. Nanoparticle production by UV irradiation of combustion generated soot particles

    International Nuclear Information System (INIS)

    Stipe, Christopher B.; Choi, Jong Hyun; Lucas, Donald; Koshland, Catherine P.; Sawyer, Robert F.

    2004-01-01

    Laser ablation of surfaces normally produce high temperature plasmas that are difficult to control. By irradiating small particles in the gas phase, we can better control the size and concentration of the resulting particles when different materials are photofragmented. Here, we irradiate soot with 193 nm light from an ArF excimer laser. Irradiating the original agglomerated particles at fluences ranging from 0.07 to 0.26 J/cm 2 with repetition rates of 20 and 100 Hz produces a large number of small, unagglomerated particles, and a smaller number of spherical agglomerated particles. Mean particle diameters from 20 to 50 nm are produced from soot originally having a mean electric mobility diameter of 265nm. We use a non-dimensional parameter, called the photon/atom ratio (PAR), to aid in understanding the photofragmentation process. This parameter is the ratio of the number of photons striking the soot particles to the number of the carbon atoms contained in the soot particles, and is a better metric than the laser fluence for analyzing laser-particle interactions. These results suggest that UV photofragmentation can be effective in controlling particle size and morphology, and can be a useful diagnostic for studying elements of the laser ablation process

  1. CaII Κ Imaging to Understand UV Irradiance Variability

    Indian Academy of Sciences (India)

    tribpo

    agencies responsible for CaII emission are: the plages, the network, and the intranet work elements. The changes in the network and intranetwork elements related to solar activity are less understood, especially because of the lack of systematic and quantitative measurements of these chromospheric features. In our earlier ...

  2. UV Irradiance Enhancements by Scattering of Solar Radiation from Clouds

    Directory of Open Access Journals (Sweden)

    Uwe Feister

    2015-08-01

    Full Text Available Scattering of solar radiation by clouds can reduce or enhance solar global irradiance compared to cloudless-sky irradiance at the Earth’s surface. Cloud effects to global irradiance can be described by Cloud Modification Factors (CMF. Depending on strength and duration, irradiance enhancements affect the energy balance of the surface and gain of solar power for electric energy generation. In the ultraviolet region, they increase the risk for damage to living organisms. Wavelength-dependent CMFs have been shown to reach 1.5 even in the UV-B region at low altitudes. Ground-based solar radiation measurements in the high Andes region at altitudes up to 5917 m a.s.l showed cloud-induced irradiance enhancements. While UV-A enhancements were explained by cloud scattering, both radiation scattering from clouds and Negative Ozone Anomalies (NOA have been discussed to have caused short-time enhancement of UV-B irradiance. Based on scenarios using published CMF and additional spectroradiometric measurements at a low-altitude site, the contribution of cloud scattering to the UV-B irradiance enhancement in the Andes region has been estimated. The range of UV index estimates converted from measured UV-B and UV-A irradiance and modeled cloudless-sky ratios UV-B/erythemal UV is compatible with an earlier estimate of an extreme UV index value of 43 derived for the high Andes.

  3. CaII Κ Imaging to Understand UV Irradiance Variability

    Indian Academy of Sciences (India)

    tribpo

    (NSO/Sac Peak). The main purpose of the present paper is to separate and to derive the relative intensity and area of various chromospheric features from 424 ... 2. Results and discussion. To analyze the CaII Κ spectroheliograms and to separate various chromospheric magnetic features, we have calculated histograms ...

  4. UV-irradiation enhances rice allelopathic potential in rhizosphere soil

    DEFF Research Database (Denmark)

    Mahmood, Khalid; Khan, Muhammad Bismillah; Song, Yuan Yuan

    2013-01-01

    and genes responsible for biosynthesis of allelopathic compounds were examined after UV exposure. Phenolic compounds accumulated in rice leaves were quantified through HPLC analysis. They were significantly higher in BR-41 leaves after UV exposure. Enzyme activities (PAL and C4H) were significantly higher...... plants in native environment) and Huajingxian (low allelopathic = not able to inhibit neighboring plants, which were suppressed by higher allelopathic plants) were exposed to UV. Rhizosphere soils and leaf leachates bioassay were used to evaluate allelopathic potentials against receiver plants (barnyard...

  5. Alteration of bacteriophage attachment capacity by near-uv irradiation

    International Nuclear Information System (INIS)

    Hartman, P.S.; Eisenstark, A.

    1982-01-01

    Near-uv (NUV) (300 to 400 nm) and far-uv (FUV) (254 nm) radiations damage bacteriophage by different mechanisms. Host cell reactivation, Weigle reactivation, and multiplicity reactivation were observed upon FUV, but not upon NUV irradiation. Also, the number of his + recombinants increased with P22 bacteriophage transduction in Salmonella typhimurium after FUV, but not after NUV irradiation. This loss of reactivation and recombination after NUV irradiation was not necessarily due to host incapability to repair phage damage. Instead, the phage genome failed to enter the host cell after NUV irradiation. In the case of NUV-irradiated T7 phage, this was determined by genetic crosses with amber mutants, which demonstrated that either ''all'' or ''none'' of a T7 genome entered the Escherichia coli cell after NUV treatment. Further studies with radioactively labeled phage indicated that irradiated phage failed to adsorb to host cells. This damage by NUV was compared with the protein-DNA cross-link observed previously, when phage particles were irradiated with NUV in the presence of H 2 O 2 . H 2 O 2 (in nonlethal concentration) acts synergistically with NUV so that equivalent phage inactivation is achieved by much lower irradiation doses

  6. Physiological alterations in UV-irradiated cells: liquid holding recovery

    International Nuclear Information System (INIS)

    Aragao, B.R.

    1980-01-01

    The biochemical and physiological alterations that occur in ultraviolet irradiated cells, during liquid holding have been studied. Incubation in buffer acts not to interfer directly with the mechanic repairs but by promoting metabolic alterations that would block some irreversible and lethal physiological responses. (L.M.J.) [pt

  7. Simultaneous effect of UV-irradiation and deformation

    International Nuclear Information System (INIS)

    Turchanyi, G.; Janszky, J.; Racz, S.; Tarjan, I.

    1982-01-01

    The present paper reports on experiments performed on X-ray coloured KCl single crystals by means of dislocation photoconduction. This method makes use of the internal electric field developing in ionic crystals due to charged dislocations during their deformation. The effect of previous illuminations in the visible region on the photocurrent produced by VUV-light was also investigated, a memory effect and changes of the sign of the photocurrents were found under suitable conditions. It was shown that using visible light of high enough intensity the direction of the photocurrent produced by it also changes sign. The problems involved in the dislocation photoconduction method are discussed. (author)

  8. Muscle cell adhesion on polytetrafluorethylene modified by UV irradiation

    Czech Academy of Sciences Publication Activity Database

    Švorčík, V.; Walachová, K.; Heitz, J.; Gumpenberger, T.; Bačáková, Lucie

    2001-01-01

    Roč. 20, č. 21 (2001), s. 1941-42 ISSN 0261-8028 R&D Projects: GA AV ČR IAA7011908 Grant - others:Vědeckotechnická spolupráce Rakousko-Česká republika(XE) KONTAKT ME 6/2000 Institutional research plan: CEZ:AV0Z5011922 Keywords : polytetrafluoroethylene ( PTFE ) * UV radiation Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 0.489, year: 2001

  9. Hyaluronan minimizes effects of UV irradiation on human keratinocytes

    Czech Academy of Sciences Publication Activity Database

    Hašová, M.; Crhák, Tomáš; Šafaříková, Barbora; Dvořáková, J.; Muthný, T.; Velebný, V.; Kubala, Lukáš

    2011-01-01

    Roč. 303, č. 4 (2011), s. 277-284 ISSN 0340-3696 R&D Projects: GA ČR(CZ) GA305/08/1704 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : hyaluronan * keratinocyte * ultraviolet light Subject RIV: BO - Biophysics Impact factor: 2.279, year: 2011

  10. Replicative intermediates in UV-irradiated Simian virus 40

    International Nuclear Information System (INIS)

    Clark, J.M.; Hanawalt, P.C.

    1984-01-01

    The authors have used Simian virus 40 (SV40) as a probe to study the replication of UV-damaged DNA in mammalian cells. Viral DNA replication in infected monkey kidney cells was synchronized by incubating a mutant of SV40 (tsA58) temperature-sensitive for the initiation of DNA synthesis at the restrictive temperature and then adding aphidicolin to temporarily inhibit DNA synthesis at the permissive temperature while permitting pre-replicative events to occur. After removal of the drug, the infected cells were irradiated at 100 J/m 2 (254 nm) to produce 6-7 pyrimidine dimers per SV40 genome, and returned to the restrictive temperature to prevent reinitiation of replication from the SV40 origin. Replicative intermediates (RI) were labeled with [ 3 H]thymidine. The size distribution of daughter DNA strands in RI isolated shortly after irradiation was skewed towards lengths less than the interdimer spacing in parental DNA; this bias persisted for at least 1 h after irradiation, but disappeared within 3 h by which time the size of the newly-synthesized DNA exceeded the interdimer distance. Evidence was obtained for the generation at late times after irradiation, of Form I molecules in which the daughter DNA strand contain dimers. Thus DNA strand exchange as well as trans-dimer synthesis may be involved in the generation of supercoiled Form I DNA from 0V-damaged SV40 replicative intermediates. (Auth.)

  11. Degradation Mechanisms of Transparent Polyurethane Interlayer under UV Irradiation

    Directory of Open Access Journals (Sweden)

    OU Yingchun

    2017-01-01

    Full Text Available According to the ageing problem of laminated transparency, the trasparent polyurethane film used as interlayer had been irradiated by fluorescent ultraviolet lamp for 0 h, 200 h, 300 h, and 500 h respectively. With the aid of ultraviolet/visible spectrophotometer, FTIR and SEM etc., the color, structure and morphology of the materials were studied. SEM shows that when the irradiation time is increased to 500 h, the film surface cracks. The UV degradation mechanisms are that -CH2- of the position connecting the O and N from hard segment and the soft segment are easy to oxidize and produce hydrogen peroxide under UV and oxygen, which is furtherly oxidized to CO, and some part of the C-O and C-N bonds is cracked through β scission, and then the materials are fractured.

  12. Photodegradation of Trace Trichloronitromethane in Water under UV Irradiation

    Directory of Open Access Journals (Sweden)

    Lin Deng

    2014-01-01

    Full Text Available This study’s objective was to study the photodegradation of TCNM (trichloronitromethane in water under UV light. The effects of light intensity, nitrate ions, chloride ions, humic acid, and pH on the photochemical degradation of TCNM were investigated under the irradiation of low pressure mercury lamp (λ = 254 nm, 12 W. The photodegradation rate of TCNM was found to increase with increasing the concentration of nitrate ions, chloride ions, humic acid, pH, and light intensity. The photodegradation of TCNM was examined at pH 6.0 with initial concentrations (C0 of TCNM at 10.0–200.0 µg/L. The overall rate of degradation of TCNM was modeled using a pseudofirst-order rate law. Finally, the proposed mechanism involved in the photodegradation of TCNM was also discussed by analysis. Results of this study can contribute to the development of new source control strategies for minimization of TCNM risk at drinking water and wastewater utilities.

  13. Proteolytic activities in yeast after UV irradiation. Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    Schwencke, J.; Moustacchi, E.

    1982-04-01

    Specific proteolytic activities are known to be induced in Escherichia coli following irradiation. Consequently it seemed of interest to investigate whether variations in proteinase activities occur in yeast. Among the five most well known proteinases of Saccharomyces cerevisiae, we have found that proteinase B activity increases up to three times in wild-type RAD/sup +/ yeast cells after a dose of 50 Jm/sup -2/ of 254 nm ultraviolet light (40% survival). Carboxypeptidase Y and aminopeptidase I (leucin aminopeptidase) activities were only moderately increased. Proteinase A activity was only slightly enhanced, while aminopeptidase II (lysin aminopeptidase) was unaffected in both RAD/sup +/ strains studied. The observed post UV-increase in proteinase B activity was inhibited by cycloheximide and was dose dependent. Increases in proteinase B levels were independent of the activation method used to destroy the proteinase B-inhibitor complex present in the crude yeast extracts. A standard method for comparison of the postirradiation levels among different proteinases, strains and methods of activation is presented.

  14. UV irradiation of Shigella dysenteriae induced the transformation ...

    African Journals Online (AJOL)

    253.7 nm) with in-tervening outgrowth of survivors gave rise to clear bacteriophage plaques. Isolation, propagation and partial purification of the new Shd-4L10 phages showed that they are similar in morphology to the Myxobacteriaphage ...

  15. Airborne Lidar Surface Topography (LIST) Simulator

    Science.gov (United States)

    Yu, Anthony W.; Krainak, Michael A.; Harding, David J.; Abshire, James B.; Sun, Xiaoli; Cavanaugh, John; Valett, Susan; Ramos-Izquierdo, Luis; Winkert, Tom; Plants, Michael; hide

    2011-01-01

    In this paper we will discuss our development effort of an airborne instrument as a pathfinder for the Lidar Surface Technology (LIST) mission. This paper will discuss the system approach, enabling technologies, instrument concept and performance of the Airborne LIST Simulator (A-LISTS).

  16. Resuscitation effects of catalase on airborne bacteria.

    OpenAIRE

    Marthi, B; Shaffer, B T; Lighthart, B; Ganio, L

    1991-01-01

    Catalase incorporation into enumeration media caused a significant increase (greater than 63%) in the colony-forming abilities of airborne bacteria. Incubation for 30 to 60 min of airborne bacteria in collection fluid containing catalase caused a greater than 95% increase in colony-forming ability. However, catalase did not have any effects on enumeration at high relative humidities (80 to 90%).

  17. Geronimo: Planning Considerations for Employing Airborne Forces

    Science.gov (United States)

    2017-05-25

    risk mitigation measure in crisis response scenarios, correlates to successful operations . In fact, operations undertaken without 100 or more days...22 4 Planning Time Allotted for Airborne Selected Airborne Operation ............................. 29 5 Summary Risk ...considerations. The doctrinal and service requirements provide a planner with a toolkit for mitigating risk prior to execution of an operation . First, a

  18. Airborne Oceanographic Lidar (AOL) (Global Carbon Cycle)

    Science.gov (United States)

    2003-01-01

    This bimonthly contractor progress report covers the operation, maintenance and data management of the Airborne Oceanographic Lidar and the Airborne Topographic Mapper. Monthly activities included: mission planning, sensor operation and calibration, data processing, data analysis, network development and maintenance and instrument maintenance engineering and fabrication.

  19. Digital airborne camera introduction and technology

    CERN Document Server

    Sandau, Rainer

    2014-01-01

    The last decade has seen great innovations on the airborne camera. This book is the first ever written on the topic and describes all components of a digital airborne camera ranging from the object to be imaged to the mass memory device.

  20. Realization of a scalable airborne radar

    NARCIS (Netherlands)

    Otten, M.P.G.; Vermeulen, B.C.B.; Liempt, L.J. van; Halsema, D. van; Jongh, R.V. de; Es, J. van

    2008-01-01

    Modern airborne ground surveillance radar systems are increasingly based on Active Electronically Scanned Array (AESA) antennas. Efficient use of array technology and the need for radar solutions for various airborne platforms, manned and unmanned, leads to the design of scalable radar systems. The

  1. Geophex Airborne Unmanned Survey System

    International Nuclear Information System (INIS)

    Won, I.L.; Keiswetter, D.

    1995-01-01

    Ground-based surveys place personnel at risk due to the proximity of buried unexploded ordnance (UXO) items or by exposure to radioactive materials and hazardous chemicals. The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide stand-off capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected. The Geophex Airborne Unmanned Survey System (GAUSS) is designed to detect and locate small-scale anomalies at hazardous sites using magnetic and electromagnetic survey techniques. The system consists of a remotely-piloted, radio-controlled, model helicopter (RCH) with flight computer, light-weight geophysical sensors, an electronic positioning system, a data telemetry system, and a computer base-station. The report describes GAUSS and its test results

  2. Airborne gamma ray spectrometer surveying

    International Nuclear Information System (INIS)

    1991-01-01

    The International Atomic Energy Agency (IAEA) in its role as collector and disseminator of information on nuclear techniques has long had an interest in gamma ray spectrometer methods and has published a number of Technical Reports on various aspects of the subject. At an Advisory Group Meeting held in Vienna in November 1986 to review appropriate activities the IAEA could take following the Chernobyl accident, it was recommended that preparation begin on a new Technical Report on airborne gamma ray spectrometer surveying, taking into account the use of the technique for environmental monitoring as well as for nuclear emergency response requirements. Shortly thereafter the IAEA became the lead organization in the Radioelement Geochemical Mapping section of the International Geological Correlation Programme/United Nations Educational, Scientific and Cultural Organization (UNESCO) Project on International Geochemical Mapping. These two factors led to the preparation of the present Technical Report. 18 figs, 4 tabs

  3. Airborne remote sensing of forest biomes

    Science.gov (United States)

    Sader, Steven A.

    1987-01-01

    Airborne sensor data of forest biomes obtained using an SAR, a laser profiler, an IR MSS, and a TM simulator are presented and examined. The SAR was utilized to investigate forest canopy structures in Mississippi and Costa Rica; the IR MSS measured forest canopy temperatures in Oregon and Puerto Rico; the TM simulator was employed in a tropical forest in Puerto Rico; and the laser profiler studied forest canopy characteristics in Costa Rica. The advantages and disadvantages of airborne systems are discussed. It is noted that the airborne sensors provide measurements applicable to forest monitoring programs.

  4. Airborne Multi-Gas Sensor, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Mesa Photonics has developed laser-based gas sensor technology compatible with UAV deployment. Our Airborne MUlti-Gas Sensor (AMUGS) technology is based upon...

  5. Airborne Radar Search for Diesel Submarines (ARSDS)

    National Research Council Canada - National Science Library

    Pilnick, Steven E; Landa, Jose

    2005-01-01

    .... In this research, a detection rate model is developed to analyze the effectiveness of an airborne radar search for a diesel submarine assumed to be intermittently operating with periscopes or masts...

  6. Airborne Radar Search for Diesel Submarines

    National Research Council Canada - National Science Library

    Pilnick, Steven E; Landa, Jose

    2005-01-01

    .... In this research, a detection rate model is developed to analyze the effectiveness of airborne radar search for a diesel submarine assumed to be intermittently operating with periscopes or masts...

  7. Airborne radioactive contamination following aerosol ventilation studies

    International Nuclear Information System (INIS)

    Mackie, A.; Hart, G.C.; Ibbett, D.A.; Whitehead, R.J.S.

    1994-01-01

    Lung aerosol ventilation studies may be accompanied by airborne contamination, with subsequent surface contamination. Airborne contamination has been measured prior to, during and following 59 consecutive 99 Tc m -diethylenetriamine pentaacetate (DTPA) aerosol studies using a personal air sampler. Airborne contamination ranging between 0 and 20 330 kBq m -3 has been measured. Airborne contamination increases with degree of patient breathing difficulty. The effective dose equivalent (EDE) to staff from ingested activity has been calculated to be 0.3 μSv per study. This figure is supported by data from gamma camera images of a contaminated staff member. However, surface contamination measurements reveal that 60% of studies exceed maximum permissible contamination limits for the hands; 16% of studies exceed limits for controlled area surfaces. (author)

  8. Airborne Laser (ABL): Issues for Congress

    National Research Council Canada - National Science Library

    Bolkcom, Christopher; Hildreth, Steven A

    2007-01-01

    Funding for the Airborne Laser (ABL) program began in FY1994, but the technologies supporting the ABL effort has evolved over 25 years of research and development concerning laser power concepts, pointing and tracking, and adaptive optics...

  9. SMEX03 Airborne GPS Bistatic Radar Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains measurements of Global Positioning System (GPS) signals reflected from the Earth’s surface and collected on an airborne platform. The...

  10. Airborne Multi-Gas Sensor, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Mesa Photonics proposes to develop an Airborne Multi-Gas Sensor (AMUGS) based upon two-tone, frequency modulation spectroscopy (TT-FMS). Mesa Photonics has developed...

  11. Miniaturized Airborne Imaging Central Server System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a miniaturized airborne imaging central server system (MAICSS). MAICSS is designed as a high-performance-computer-based electronic backend that...

  12. Miniaturized Airborne Imaging Central Server System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a miniaturized airborne imaging central server system (MAICSS). MAICSS is designed as a high-performance computer-based electronic backend that...

  13. Regenerable Lunar Airborne Dust Filter, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Effective methods are needed to control pervasive Lunar Dust within spacecraft and surface habitations. Once inside, airborne transmission is the primary mode of...

  14. Voxel inversion of airborne EM data

    DEFF Research Database (Denmark)

    Fiandaca, Gianluca G.; Auken, Esben; Christiansen, Anders Vest C A.V.C.

    2013-01-01

    of prior information. Inversion of geophysical data usually refers to a model space being linked to the actual observation points. For airborne surveys the spatial discretization of the model space reflects the flight lines. Often airborne surveys are carried out in areas where other ground-based...... geophysical data are available. The model space of geophysical inversions is usually referred to the positions of the measurements, and ground-based model positions do not generally coincide with the airborne model positions. Consequently, a model space based on the measuring points is not well suited...... for jointly inverting airborne and ground-based geophysical data. Furthermore, geological and groundwater models most often refer to a regular voxel grid not correlated to the geophysical model space, and incorporating the geophysical data into the geological/hydrological modelling grids is problematic. We...

  15. Challenges and Opportunities of Airborne Metagenomics

    KAUST Repository

    Behzad, H.

    2015-05-06

    Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles.

  16. Airborne infections and modern building technology

    Energy Technology Data Exchange (ETDEWEB)

    LaForce, F.M.

    1986-01-01

    Over the last 30 yr an increased appreciation of the importance of airborne infection has evolved. The concept of droplet nuclei, infectious particles from 0.5 to 3 ..mu.. which stay suspended in air for long periods of time, has been accepted as an important determinant of infectivity. Important airborne pathogens in modern buildings include legionella pneumophila, Aspergillus sp., thermophilic actinomycetes, Mycobacterium tuberculosis, measles, varicella and rubella. Perhaps, the most important microbiologic threat to most buildings is L. pneumophila. This organism can multiply in water cooling systems and contaminate effluent air which can be drawn into a building and efficiently circulated throughout by existing ventilation systems. Hospitals are a special problem because of the concentration of immunosuppressed patients who are uniquely susceptible to airborne diseases such as aspergillosis, and the likelihood that patients ill from diseases that can be spread via the airborne route will be concentrated. Humidifiers are yet another problem and have been shown to be important in several outbreaks of allergic alveolitis and legionellosis. Control of airborne infections is largely an effort at identifying and controlling reservoirs of infection. This includes regular biocide treatment of cooling towers and evaporative condensers and identification and isolation of patients with diseases that may be spread via the airborne route.

  17. Mapping permafrost with airborne electromagnetics

    Science.gov (United States)

    Minsley, B. J.; Ball, L. B.; Bloss, B. R.; Kass, A.; Pastick, N.; Smith, B. D.; Voss, C. I.; Walsh, D. O.; Walvoord, M. A.; Wylie, B. K.

    2014-12-01

    Permafrost is a key characteristic of cold region landscapes, yet detailed assessments of how the subsurface distribution of permafrost impacts the environment, hydrologic systems, and infrastructure are lacking. Data acquired from several airborne electromagnetic (AEM) surveys in Alaska provide significant new insight into the spatial extent of permafrost over larger areas (hundreds to thousands of square kilometers) than can be mapped using ground-based geophysical methods or through drilling. We compare several AEM datasets from different areas of interior Alaska, and explore the capacity of these data to infer geologic structure, permafrost extent, and related hydrologic processes. We also assess the impact of fires on permafrost by comparing data from different burn years within similar geological environments. Ultimately, interpretations rely on understanding the relationship between electrical resistivity measured by AEM surveys and the physical properties of interest such as geology, permafrost, and unfrozen water content in the subsurface. These relationships are often ambiguous and non-unique, so additional information is useful for reducing uncertainty. Shallow (upper ~1m) permafrost and soil characteristics identified from remotely sensed imagery and field observations help to constrain and aerially extend near-surface AEM interpretations, where correlations between the AEM and remote sensing data are identified using empirical multivariate analyses. Surface nuclear magnetic resonance (sNMR) measurements quantify the contribution of unfrozen water at depth to the AEM-derived electrical resistivity models at several locations within one survey area. AEM surveys fill a critical data gap in the subsurface characterization of permafrost environments and will be valuable in future mapping and monitoring programs in cold regions.

  18. NAMMA SECOND GENERATION AIRBORNE PRECIPITATION RADAR (APR-2) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NAMMA Second Generation Airborne Precipitation Radar (APR-2) dataset was collected by using the Second Generation Airborne Precipitation Radar (APR-2), which is...

  19. Total Shallow-Water Survey Through Airborne Hydrography

    National Research Council Canada - National Science Library

    Wozencraft, Jennifer M; Lillycrop, W. J

    2002-01-01

    Eight years of SHOALS (Scanning Hydrographic Operational Airborne Lidar Survey) operations have proven that airborne bathymetric lidar is an ideal tool for rapidly measuring shallow water depths and nearshore land elevations...

  20. Appendix : airborne incidents : an econometric analysis of severity

    Science.gov (United States)

    2014-12-19

    This is the Appendix for Airborne Incidents: An Econometric Analysis of Severity Report. : Airborne loss of separation incidents occur when an aircraft breaches the defined separation limit (vertical and/or horizontal) with another aircraft or terrai...

  1. GRIP AIRBORNE SECOND GENERATION PRECIPITATION RADAR (APR-2) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GRIP Airborne Second Generation Precipitation Radar (APR-2) dataset was collected from the Second Generation Airborne Precipitation Radar (APR-2), which is a...

  2. An Airborne Capability for South Africa from a Special Operations ...

    African Journals Online (AJOL)

    term strategy, and airborne forces form an important component in its envisioned Contingency Brigade. This article examines the utility of contemporary airborne forces despite the decline in major parachute assaults. It also explains the ...

  3. CAMEX-4 ER-2 MODIS AIRBORNE SIMULATOR (MAS) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The MODIS Airborne Simulator (MAS) is an airborne scanning spectrometer that acquires high spatial resolution imagery of cloud and surface features from its vantage...

  4. TCSP ER-2 MODIS AIRBORNE SIMULATOR (MAS) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The TCSP ER-2 MODIS Airborne Simulator (MAS) dataset was collected by a MODIS Airborne Simulator (MAS), which is a multi-spectral line-scanner system that acquires...

  5. Challenges and opportunities of airborne metagenomics.

    Science.gov (United States)

    Behzad, Hayedeh; Gojobori, Takashi; Mineta, Katsuhiko

    2015-05-06

    Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  6. Urban greenness influences airborne bacterial community composition.

    Science.gov (United States)

    Mhuireach, Gwynne; Johnson, Bart R; Altrichter, Adam E; Ladau, Joshua; Meadow, James F; Pollard, Katherine S; Green, Jessica L

    2016-11-15

    Urban green space provides health benefits for city dwellers, and new evidence suggests that microorganisms associated with soil and vegetation could play a role. While airborne microorganisms are ubiquitous in urban areas, the influence of nearby vegetation on airborne microbial communities remains poorly understood. We examined airborne microbial communities in parks and parking lots in Eugene, Oregon, using high-throughput sequencing of the bacterial 16S rRNA gene on the Illumina MiSeq platform to identify bacterial taxa, and GIS to measure vegetation cover in buffer zones of different diameters. Our goal was to explore variation among highly vegetated (parks) versus non-vegetated (parking lots) urban environments. A secondary objective was to evaluate passive versus active collection methods for outdoor airborne microbial sampling. Airborne bacterial communities from five parks were different from those of five parking lots (p=0.023), although alpha diversity was similar. Direct gradient analysis showed that the proportion of vegetated area within a 50m radius of the sampling station explained 15% of the variation in bacterial community composition. A number of key taxa, including several Acidobacteriaceae were substantially more abundant in parks, while parking lots had higher relative abundance of Acetobacteraceae. Parks had greater beta diversity than parking lots, i.e. individual parks were characterized by unique bacterial signatures, whereas parking lot communities tended to be similar to each other. Although parks and parking lots were selected to form pairs of nearby sites, spatial proximity did not appear to affect compositional similarity. Our results also showed that passive and active collection methods gave comparable results, indicating the "settling dish" method is effective for outdoor airborne sampling. This work sets a foundation for understanding how urban vegetation may impact microbial communities, with potential implications for designing

  7. Hyperspectral airborne remote sensing of the Belgian coastal waters

    OpenAIRE

    Sterckx, S.; Debruyn, W.; Kempeneers, P.

    2005-01-01

    On the 16th of June 2003 a CASI (Compact Airborne Spectrographic Imager) hyperspectral airborne remote sensing campaign took place above the Southern North Sea, just offshore of Oostende. In coincidence with the airborne overpasses seaborne measurements of water leaving reflectance and water quality parameters were performed. In addition near-simultaneous satellite imagery are available. This paper deals with the analysis of the airborne data. The CASI data have been atmospherically corrected...

  8. NASA Airborne Astronomy Ambassadors (AAA)

    Science.gov (United States)

    Backman, D. E.; Harman, P. K.; Clark, C.

    2016-12-01

    NASA's Airborne Astronomy Ambassadors (AAA) is a three-part professional development (PD) program for high school physics and astronomy teachers. The AAA experience consists of: (1) blended-learning professional development composed of webinars, asynchronous content learning, and a series of hands-on workshops (2) a STEM immersion experience at NASA Armstrong Flight Research Center's B703 science research aircraft facility in Palmdale, California, and (3) ongoing participation in the AAA community of practice (CoP) connecting participants with astrophysics and planetary science Subject Matter Experts (SMEs). The SETI Institute (SI) is partnering with school districts in Santa Clara and Los Angeles Counties during the AAA program's "incubation" period, calendar years 2016 through 2018. AAAs will be selected by the school districts based on criteria developed during spring 2016 focus group meetings led by the program's external evaluator, WestEd.. Teachers with 3+ years teaching experience who are assigned to teach at least 2 sections in any combination of the high school courses Physics (non-AP), Physics of the Universe (California integrated model), Astronomy, or Earth & Space Sciences are eligible. Partner districts will select at least 48 eligible applicants with SI oversight. WestEd will randomly assign selected AAAs to group A or group B. Group A will complete PD in January - June of 2017 and then participate in SOFIA science flights during fall 2017 (SOFIA Cycle 5). Group B will act as a control during the 2017-18 school year. Group B will then complete PD in January - June of 2018 and participate in SOFIA science flights in fall 2018 (Cycle 6). Under the current plan, opportunities for additional districts to seek AAA partnerships with SI will be offered in 2018 or 2019. A nominal two-week AAA curriculum component will be developed by SI for classroom delivery that will be aligned with selected California Draft Science Framework Disciplinary Core Ideas

  9. 14 CFR 121.357 - Airborne weather radar equipment requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... § 121.357 Airborne weather radar equipment requirements. (a) No person may operate any transport... December 31, 1964, unless approved airborne weather radar equipment has been installed in the airplane. (b...

  10. 14 CFR 135.175 - Airborne weather radar equipment requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... Aircraft and Equipment § 135.175 Airborne weather radar equipment requirements. (a) No person may operate a... conditions that can be detected with airborne weather radar equipment, may reasonably be expected along the...

  11. 14 CFR 125.223 - Airborne weather radar equipment requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... Equipment Requirements § 125.223 Airborne weather radar equipment requirements. (a) No person may operate an airplane governed by this part in passenger-carrying operations unless approved airborne weather radar...

  12. 30 CFR 57.5001 - Exposure limits for airborne contaminants.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Exposure limits for airborne contaminants. 57... Underground § 57.5001 Exposure limits for airborne contaminants. Except as permitted by § 57.5005— (a) Except as provided in paragraph (b), the exposure to airborne contaminants shall not exceed, on the basis of...

  13. CLPX Airborne: Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) Data, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set consists of apparent surface reflectance, subpixel snow-covered area and grain size inferred from data acquired by the Airborne Visible/Infrared...

  14. Airborne Gravity: NGS' Airborne Gravity Data for AN01 (2009-2010)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2009-2010 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

  15. Human Indoor Exposure to Airborne Halogenated Flame Retardants: Influence of Airborne Particle Size

    OpenAIRE

    La Guardia, Mark J.; Schreder, Erika D.; Uding, Nancy; Hale, Robert C.

    2017-01-01

    Inhalation of halogenated flame-retardants (HFRs) released from consumer products is an important route of exposure. However, not all airborne HFRs are respirable, and thus interact with vascular membranes within the gas exchange (alveolar) region of the lung. HFRs associated with large (>4 ?m), inhalable airborne particulates are trapped on the mucosal lining of the respiratory tract and then are expelled or swallowed. The latter may contribute to internal exposure via desorption from partic...

  16. Airborne microorganisms and dust from livestock houses

    NARCIS (Netherlands)

    Zhao, Y.; Aarnink, A.J.A.; Jong, de M.C.M.; Groot Koerkamp, P.W.G.

    2011-01-01

    The objective of this study was to evaluate the efficiencies and suitability of samplers for airborne microorganisms and dust, which could be used in practical livestock houses. Two studies were performed: 1) Testing impaction and cyclone pre-separators for dust sampling in livestock houses; 2)

  17. Experimental airborne transmission of PRRS virus

    DEFF Research Database (Denmark)

    Kristensen, C.S.; Bøtner, Anette; Takai, H.

    2004-01-01

    A series of three experiments, differing primarily in airflow volume, were performed to evaluate the likelihood of airborne transmission of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) from infected to non-infected pigs. Pigs were housed in two units (unit A and unit B) located 1 m...

  18. Geoid of Nepal from airborne gravity survey

    DEFF Research Database (Denmark)

    Forsberg, René; Olesen, Arne Vestergaard; Einarsson, Indriði

    2011-01-01

    An airborne gravity survey of Nepal was carried out December 2010 in a cooperation between DTU-Space, Nepal Survey Department, and NGA, USA. The entire country was flown with survey lines spaced 6 nm with a King Air aircraft, with a varying flight altitude from 4 to 10 km. The survey operations w...

  19. Topology optimized cloak for airborne sound

    DEFF Research Database (Denmark)

    Andkjær, Jacob Anders; Sigmund, Ole

    2013-01-01

    Directional acoustic cloaks that conceal an aluminum cylinder for airborne sound waves are presented in this paper. Subwavelength cylindrical aluminum inclusions in air constitute the cloak design to aid practical realizations. The positions and radii of the subwavelength cylinders are determined...

  20. Passive Sampling of Airborne Peroxyacetic Acid

    NARCIS (Netherlands)

    Henneken, H.; Assink, Laura; de Wit, Joyce; Vogel, M.; Karst, U.

    2006-01-01

    The first passive sampling device for the determination of airborne peroxyacetic acid (PAA) is presented. 2-([3-{2-[4-Amino-2-(methylsulfanyl)phenyl]-1-diazenyl}phenyl]sulfonyl)-1-ethanol (ADS) is used to impregnate glass fiber filters, and the reagent is oxidized by PAA to the corresponding

  1. Airborne gravity field Measurements - status and developments

    DEFF Research Database (Denmark)

    Olesen, Arne Vestergaard; Forsberg, René

    2016-01-01

    English Abstract:DTU-Space has since 1996 carried out large area airborne surveys over both polar, tropical and temperate regions, especially for geoid determination and global geopotential models. Recently we have started flying two gravimeters (LCR and Chekan-AM or inertial navigation systems) ...

  2. Airborne radioactive effluents: releases and processing

    International Nuclear Information System (INIS)

    Grissom, M.C.

    1982-10-01

    This bibliography contains 870 citations on airborne radioactive waste included in the Department of Energy's Energy Data Base from January 1981 through August 1982. These citations are to research reports, journal articles, books, patents, theses, and conference papers from worldwide sources. Five indexes, each preceded by a brief description, are provided: Corporate Author, Personal Author, Subject, Contract Number, and Report Number

  3. CALIOPE airborne CO{sub 2} DIAL (CACDI) system design

    Energy Technology Data Exchange (ETDEWEB)

    Mietz, D.; Archuleta, B.; Archuleta, J. [and others

    1997-09-01

    Los Alamos National Laboratory is currently developing an airborne CO{sub 2} Differential Absorption Lidar (DIAL) system based on second generation technology demonstrated last summer at NTS. The CALIOPE Airborne CO{sub 2} DIAL (CACDI) system requirements have been compiled based on the mission objectives and SONDIAL model trade studies. Subsystem designs have been developed based on flow down from these system requirements, as well as experience gained from second generation ground tests and N-ABLE (Non-proliferation AirBorne Lidar Experiments) airborne experiments. This paper presents the CACDI mission objectives, system requirements, the current subsystem design, and provides an overview of the airborne experimental plan.

  4. Airborne laser sensors and integrated systems

    Science.gov (United States)

    Sabatini, Roberto; Richardson, Mark A.; Gardi, Alessandro; Ramasamy, Subramanian

    2015-11-01

    The underlying principles and technologies enabling the design and operation of airborne laser sensors are introduced and a detailed review of state-of-the-art avionic systems for civil and military applications is presented. Airborne lasers including Light Detection and Ranging (LIDAR), Laser Range Finders (LRF), and Laser Weapon Systems (LWS) are extensively used today and new promising technologies are being explored. Most laser systems are active devices that operate in a manner very similar to microwave radars but at much higher frequencies (e.g., LIDAR and LRF). Other devices (e.g., laser target designators and beam-riders) are used to precisely direct Laser Guided Weapons (LGW) against ground targets. The integration of both functions is often encountered in modern military avionics navigation-attack systems. The beneficial effects of airborne lasers including the use of smaller components and remarkable angular resolution have resulted in a host of manned and unmanned aircraft applications. On the other hand, laser sensors performance are much more sensitive to the vagaries of the atmosphere and are thus generally restricted to shorter ranges than microwave systems. Hence it is of paramount importance to analyse the performance of laser sensors and systems in various weather and environmental conditions. Additionally, it is important to define airborne laser safety criteria, since several systems currently in service operate in the near infrared with considerable risk for the naked human eye. Therefore, appropriate methods for predicting and evaluating the performance of infrared laser sensors/systems are presented, taking into account laser safety issues. For aircraft experimental activities with laser systems, it is essential to define test requirements taking into account the specific conditions for operational employment of the systems in the intended scenarios and to verify the performance in realistic environments at the test ranges. To support the

  5. First airborne transient em survey in antarctica

    DEFF Research Database (Denmark)

    Auken, Esben; Mikucki, J. J.; Sørensen, Kurt Ingvard K.I.

    2012-01-01

    A first airborne transient electromagnetic survey was flown in Antarctica in December 2011 with the SkyTEM system. This transient airborne EM system has been optimized in Denmark for almost ten years and was specially designed for ground water mapping. The SkyTEM tool is ideal for mapping...... conductive targets, and the transient AEM method provides a better understanding of the saline ground water system for microbiology, paleoclimate studies, or geothermal potential. In this study we present preliminary results from our field survey which resulted in more than 1000 km of flight lines...... are presented here, the Taylor Valley demonstrating the promising capabilities of the geophysical method to map permafrost and the saline ground water systems....

  6. Designing transmitting CMUT cells for airborne applications.

    Science.gov (United States)

    Unlügedik, Aslı; Taşdelen, A; Atalar, Abdullah; Köymen, Hayrettin

    2014-11-01

    We report a new mode of airborne operation for capacitive micromachined ultrasonic transducers (CMUT), in which the plate motion spans the entire gap without collapsing and the transducer is driven by a sinusoidal voltage without a dc bias. We present equivalent-circuit-based design fundamentals for an airborne CMUT cell and verify the design targets using fabricated CMUTs. The performance limits for silicon plates are derived. We experimentally obtain 78.9 dB//20 μPa@1 m source level at 73.7 kHz, with a CMUT cell of radius 2.05 mm driven by 71 V sinusoidal drive voltage at half the frequency. The measured quality factor is 120. We also study and discuss the interaction of the nonlinear transduction force and the nonlinearity of the plate compliance.

  7. Analyzing Options for Airborne Emergency Wireless Communications

    Energy Technology Data Exchange (ETDEWEB)

    Michael Schmitt; Juan Deaton; Curt Papke; Shane Cherry

    2008-03-01

    In the event of large-scale natural or manmade catastrophic events, access to reliable and enduring commercial communication systems is critical. Hurricane Katrina provided a recent example of the need to ensure communications during a national emergency. To ensure that communication demands are met during these critical times, Idaho National Laboratory (INL) under the guidance of United States Strategic Command has studied infrastructure issues, concerns, and vulnerabilities associated with an airborne wireless communications capability. Such a capability could provide emergency wireless communications until public/commercial nodes can be systematically restored. This report focuses on the airborne cellular restoration concept; analyzing basic infrastructure requirements; identifying related infrastructure issues, concerns, and vulnerabilities and offers recommended solutions.

  8. Airborne geophysics in Australia: the government contribution

    International Nuclear Information System (INIS)

    Denham, D.

    1997-01-01

    Airborne geophysical data sets provide important cost-effective information for resource exploration and land management. Improved techniques, developed recently, now enable high-resolution aeromagnetic and gamma-ray surveys to be used extensively by the resource industries to improve the cost effectiveness of exploration and by governments to encourage resource development and sustainable management of natural resources. Although airborne geophysical techniques have been used extensively and are now used almost routinely by mineral explorers, it is only in the last few years that governments have been involved as major players in the acquisition of data. The exploration industry pioneered the imaging of high-resolution airborne geophysical data sets in the early 1980s and, at the same time, the Northern Territory Government started a modest program of flying the Northern Territory, at 500 m flight-line spacing, to attract mineral exploration. After the start of the National Geoscience Mapping Accord in 1990, the then BMR and its State/Territory counterparts used the new high-resolution data as an essential ingredient to underpin mapping programs. These new data sets proved so valuable that, starting in 1992/93, the annual expenditure by the Commonwealth and States/Northern Territory increased from roughly $2 million per year to a massive $10 million per year. These investments by governments, although unlikely to be permanently sustainable, have been made to encourage and expand exploration activity by providing new high-quality data sets in industry at very low cost. There are now approximately 11 million line-km of airborne geophysical data available in databases held by the Commonwealth, States and Northern Territory. The results so far have seen a significant increase in exploration activity in States that have embarked on this course (e.g. South Australia and Victoria), and the information provided from these surveys is proving crucial to understanding the

  9. The Caltech airborne submillimeter SIS receiver

    Science.gov (United States)

    Zmuidzinas, Jonas; Carlstrom, J.; Miller, D.; Ugras, N. G.

    1995-01-01

    We have constructed a sensitive submillimeter receiver for the NASA Kuiper Airborne Observatory (KAO) which at present operates in the 500-750 GHz band. The DSB receiver noise temperature is about 5 h nu/k(sub B) over the 500-700 GHz range. This receiver has been used to detect H2O(18)O, HCl, and CH in interstellar molecular clouds, and also to search for C(+) emission from the highly redshifted galaxy (z = 2.3) IRAS 10214.

  10. Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE)

    Science.gov (United States)

    Schwemmer, Geary K.

    1998-01-01

    Scanning holographic lidar receivers are currently in use in two operational lidar systems, PHASERS (Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing) and now HARLIE (Holographic Airborne Rotating Lidar Instrument Experiment). These systems are based on volume phase holograms made in dichromated gelatin (DCG) sandwiched between 2 layers of high quality float glass. They have demonstrated the practical application of this technology to compact scanning lidar systems at 532 and 1064 nm wavelengths, the ability to withstand moderately high laser power and energy loading, sufficient optical quality for most direct detection systems, overall efficiencies rivaling conventional receivers, and the stability to last several years under typical lidar system environments. Their size and weight are approximately half of similar performing scanning systems using reflective optics. The cost of holographic systems will eventually be lower than the reflective optical systems depending on their degree of commercialization. There are a number of applications that require or can greatly benefit from a scanning capability. Several of these are airborne systems, which either use focal plane scanning, as in the Laser Vegetation Imaging System or use primary aperture scanning, as in the Airborne Oceanographic Lidar or the Large Aperture Scanning Airborne Lidar. The latter class requires a large clear aperture opening or window in the aircraft. This type of system can greatly benefit from the use of scanning transmission holograms of the HARLIE type because the clear aperture required is only about 25% larger than the collecting aperture as opposed to 200-300% larger for scan angles of 45 degrees off nadir.

  11. Airborne Tactical Free-Electron Laser

    Energy Technology Data Exchange (ETDEWEB)

    Whitney, Roy; Neil, George

    2007-02-01

    The goal of 100 kilowatts (kW) of directed energy from an airborne tactical platform has proved challenging due to the size and weight of most of the options that have been considered. However, recent advances in Free-Electron Lasers appear to offer a solution along with significant tactical advantages: a nearly unlimited magazine, time structures for periods from milliseconds to hours, radar like functionality, and the choice of the wavelength of light that best meets mission requirements. For an Airborne Tactical Free-Electron Laser (ATFEL) on a platforms such as a Lockheed C-130J-30 and airships, the two most challenging requirements, weight and size, can be met by generating the light at a higher harmonic, aggressively managing magnet weights, managing cryogenic heat loads using recent SRF R&D results, and using FEL super compact design concepts that greatly reduce the number of components. The initial R&D roadmap for achieving an ATFEL is provided in this paper. Performing this R&D is expected to further reduce the weight, size and power requirements for the FELs the Navy is currently developing for shipboard applications, as well as providing performance enhancements for the strategic airborne MW class FELs. The 100 kW ATFEL with its tactical advantages may prove sufficiently attractive for early advancement in the queue of deployed FELs.

  12. Airborne laser altimeter measurements of landscape topography

    International Nuclear Information System (INIS)

    Ritchie, J.C.

    1995-01-01

    Measurements of topography can provide a wealth of information on landscape properties for managing hydrologic and geologic systems and conserving natural and agricultural resources. This article discusses the application of an airborne laser altimeter to measure topography and other landscape surface properties. The airborne laser altimeter makes 4000 measurements per second with a vertical recording resolution of 5 cm. Data are collected digitally with a personal computer. A video camera, borehole sighted with the laser, records an image for locating flight lines. GPS data are used to locate flight line positions on the landscape. Laser data were used to measure vegetation canopy topography, height, cover, and distribution and to measure microtopography of the land surface and gullies with depths of 15–20 cm. Macrotopography of landscape profiles for segments up to 4 km were in agreement with available topographic maps but provided more detail. Larger gullies with and without vegetation, and stream channel cross sections and their associated floodplains have also been measured and reported in other publications. Landscape segments for any length could be measured for either micro- or macrotopography. Airborne laser altimeter measurements of landscape profiles can provide detailed information on landscape properties or specific needs that will allow better decisions on the design and location of structures (i.e., roads, pipe, and power lines) and for improving the management and conservation of natural and agricultural landscapes. (author)

  13. Geological Mapping of Sabah, Malaysia, Using Airborne Gravity Survey

    DEFF Research Database (Denmark)

    Fauzi Nordin, Ahmad; Jamil, Hassan; Noor Isa, Mohd

    2016-01-01

    Airborne gravimetry is an effective tool for mapping local gravity fields using a combination of airborne sensors, aircraft and positioning systems. It is suitable for gravity surveys over difficult terrains and areas mixed with land and ocean. This paper describes the geological mapping of Sabah...... using airborne gravity surveys. Airborne gravity data over land areas of Sabah has been combined with the marine airborne gravity data to provide a seamless land-to-sea gravity field coverage in order to produce the geological mapping. Free-air and Bouguer anomaly maps (density 2.67 g/cm3) have been...... gravity data were 5-6 km. The airborne gravity survey database for landand marine areas has been compiled using ArcGIS geodatabase format in order to produce the update geological map of Sabah....

  14. Airborne or Fomite Transmission for Norovirus? A Case Study Revisited

    OpenAIRE

    Xiao, Shenglan; Tang, Julian W.; Li, Yuguo

    2017-01-01

    Norovirus infection, a highly prevalent condition associated with a high rate of morbidity, comprises a significant health issue. Although norovirus transmission mainly occurs via the fecal-oral and vomit-oral routes, airborne transmission has been proposed in recent decades. This paper re-examines a previously described norovirus outbreak in a hotel restaurant wherein airborne transmission was originally inferred. Specifically, the original evidence that suggested airborne transmission was r...

  15. High-Performance Airborne Optical Carbon Dioxide Analyzer, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Environmental species measurement on airborne atmospheric research craft is a demanding application for optical sensing techniques. Yet optical techniques offer many...

  16. High-Performance Airborne Optical Carbon Dioxide Analyzer, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Environmental species measurement on airborne atmospheric research craft is a demanding application for optical sensing techniques. Yet optical techniques offer many...

  17. Airborne infectious disease and the suppression of pulmonary bioaerosols.

    Science.gov (United States)

    Fiegel, Jennifer; Clarke, Robert; Edwards, David A

    2006-01-01

    The current understanding of airborne pathogen spread in relation to the new methods of suppressing exhaled bioaerosols using safe surface-active materials, such as isotonic saline, is reviewed here. We discuss the physics of bioaerosol generation in the lungs, what is currently known about the relationship between expired bioaerosols and airborne infectious disease and current methods of airborne infectious disease containment. We conclude by reviewing recent experiments that suggest the delivery of isotonic saline can significantly diminish exhaled aerosol--generated from airway lining fluid in the course of natural breathing. We also discuss these implications in relation to airborne infectious disease control.

  18. Towards airborne nanoparticle mass spectrometry with nanomechanical string resonators

    DEFF Research Database (Denmark)

    Schmid, Silvan; Kurek, Maksymilian; Boisen, Anja

    2013-01-01

    airborne nanoparticle sensors. Recently, nanomechanical mass spectrometry was established. One of the biggest challenges of nanomechanical sensors is the low efficiency of diffusion-based sampling. We developed an inertial-based sampling method that enables the efficient sampling of airborne nanoparticles...... mode. Mass spectrometry of airborne nanoparticles requires the simultaneous operation in the first and second mode, which can be implemented in the transduction scheme of the resonator. The presented results lay the cornerstone for the realization of a portable airborne nanoparticle mass spectrometer....

  19. Airborne LIDAR Data Processing and Analysis Tools

    Science.gov (United States)

    Zhang, K.

    2007-12-01

    Airborne LIDAR technology allows accurate and inexpensive measurements of topography, vegetation canopy heights, and buildings over large areas. In order to provide researchers high quality data, NSF has created the National Center for Airborne Laser Mapping (NCALM) to collect, archive, and distribute the LIDAR data. However, the LIDAR systems collect voluminous irregularly-spaced, three-dimensional point measurements of ground and non-ground objects scanned by the laser beneath the aircraft. To advance the use of the technology and data, NCALM is developing public domain algorithms for ground and non-ground measurement classification and tools for data retrieval and transformation. We present the main functions of the ALDPAT (Airborne LIDAR Data Processing and Analysis Tools) developed by NCALM. While Geographic Information Systems (GIS) provide a useful platform for storing, analyzing, and visualizing most spatial data, the shear volume of raw LIDAR data makes most commercial GIS packages impractical. Instead, we have developed a suite of applications in ALDPAT which combine self developed C++ programs with the APIs of commercial remote sensing and GIS software. Tasks performed by these applications include: 1) transforming data into specified horizontal coordinate systems and vertical datums; 2) merging and sorting data into manageable sized tiles, typically 4 square kilometers in dimension; 3) filtering point data to separate measurements for the ground from those for non-ground objects; 4) interpolating the irregularly spaced elevations onto a regularly spaced grid to allow raster based analysis; and 5) converting the gridded data into standard GIS import formats. The ALDPAT 1.0 is available through http://lidar.ihrc.fiu.edu/.

  20. Even Shallower Exploration with Airborne Electromagnetics

    Science.gov (United States)

    Auken, E.; Christiansen, A. V.; Kirkegaard, C.; Nyboe, N. S.; Sørensen, K.

    2015-12-01

    Airborne electromagnetics (EM) is in many ways undergoing the same type rapid technological development as seen in the telecommunication industry. These developments are driven by a steadily increasing demand for exploration of minerals, groundwater and geotechnical targets. The latter two areas demand shallow and accurate resolution of the near surface geology in terms of both resistivity and spatial delineation of the sedimentary layers. Airborne EM systems measure the grounds electromagnetic response when subject to either a continuous discrete sinusoidal transmitter signal (frequency domain) or by measuring the decay of currents induced in the ground by rapid transmission of transient pulses (time domain). In the last decade almost all new developments of both instrument hardware and data processing techniques has focused around time domain systems. Here we present a concept for measuring the time domain response even before the transient transmitter current has been turned off. Our approach relies on a combination of new instrument hardware and novel modeling algorithms. The newly developed hardware allows for measuring the instruments complete transfer function which is convolved with the synthetic earth response in the inversion algorithm. The effect is that earth response data measured while the transmitter current is turned off can be included in the inversion, significantly increasing the amount of available information. We demonstrate the technique using both synthetic and field data. The synthetic examples provide insight on the physics during the turn off process and the field examples document the robustness of the method. Geological near surface structures can now be resolved to a degree that is unprecedented to the best of our knowledge, making airborne EM even more attractive and cost-effective for exploration of water and minerals that are crucial for the function of our societies.

  1. Precision Rectification of Airborne SAR Image

    DEFF Research Database (Denmark)

    Dall, Jørgen; Liao, M.; Zhang, Zhe

    1997-01-01

    A simple and direct procedure for the rectification of a certain class of airborne SAR data is presented. The relief displacements of SAR data are effectively removed by means of a digital elevation model and the image is transformed to the ground coordinate system. SAR data from the Danish EMISAR......([7]) is used. The EMISAR produces data with a geometrical resolution of 2.0 meters. The corrected image is tested against photogrammetric control measurements and an accuracy better than 0.5 pixel corresponding to 0.75 meters is obtained. The results indicate promising possibilities...... for the application of SAR data in the difficult process of map revision and updating....

  2. Highly Protable Airborne Multispectral Imaging System

    Science.gov (United States)

    Lehnemann, Robert; Mcnamee, Todd

    2001-01-01

    A portable instrumentation system is described that includes and airborne and a ground-based subsytem. It can acquire multispectral image data over swaths of terrain ranging in width from about 1.5 to 1 km. The system was developed especially for use in coastal environments and is well suited for performing remote sensing and general environmental monitoring. It includes a small,munpilotaed, remotely controlled airplance that carries a forward-looking camera for navigation, three downward-looking monochrome video cameras for imaging terrain in three spectral bands, a video transmitter, and a Global Positioning System (GPS) reciever.

  3. Improvements in the detection of airborne plutonium

    International Nuclear Information System (INIS)

    Ryden, D.J.

    1981-02-01

    It is shown how it is possible to compensate individually for each of the background components on the filter paper used to collect samples. Experimentally it has been shown that the resulting compensated background count-rate averages zero with a standard deviation very close to the fundamental limit set by random statistical variations. Considerable improvements in the sensitivity of detecting airborne plutonium have been achieved. Two new plutonium-in-air monitors which use the compensation schemes described in this report are now available. Both have operated successfully in high concentrations of radon daughters. (author)

  4. 1. Airborne 2. Hangár

    OpenAIRE

    Johnson, Christy

    2008-01-01

    Hangár, Bakelit Multi Art Center 7th L1 Dance Festival, Budapest, Hungary Installation, 2008 AIRBORNE (projection-sound-monitor installation) was sited in the Hangár, B.A.C. as part of the 7th L1 Dance Festival in Budapest, Hungary (March 2008). This work continues Johnson's interest in and use of 'found' material (16mm wind tunnel footage), and performative methods (sound recording of Channel 9 on United Airlines). This immersive work explores the turbulence of suspension and sets ...

  5. Airborne radioactive emission control technology. Volume III

    International Nuclear Information System (INIS)

    Skoski, L.; Berlin, R.; Corby, D.; Clancy, J.; Hoopes, G.

    1980-03-01

    This report reviews the current and future control technology for airborne emissions from a wide variety of industries/facilities, including uranium mining and milling, other nuclear fuel cycle facilities, other NRC-licensed and DOE facilities, fossil fuel facilities, selected metal and non-metal extraction industries, and others. Where specific radioactivity control technology is lacking, a description of any existing control technology is given. Future control technology is assessed in terms of improvements to equipment performance and process alterations. A catalogue of investigated research on advanced control technologies is presented

  6. Airborne radioactive emission control technology. Volume II

    International Nuclear Information System (INIS)

    Skoski, L.; Berlin, R.; Corby, D.; Clancy, J.; Hoopes, G.

    1980-03-01

    This report reviews the current and future control technology for airborne emissions from a wide variety of industries/facilities, including uranium mining and milling, other nuclear fuel cycle facilities, other NRC-licensed and DOE facilities, fossil fuel facilities, selected metal and non-metal extraction industries, and others. Where specific radioactivity control technology is lacking, a description of any existing control technology is given. Future control technology is assessed in terms of improvements to equipment performance and process alterations. A catalogue of investigated research on advanced control technologies is presented

  7. Airborne radioactive emission control technology. Volume I

    International Nuclear Information System (INIS)

    Skoski, L.; Berlin, R.; Corby, D.; Clancy, J.; Hoopes, G.

    1980-03-01

    This report reviews the current and future control technology for airborne emissions from a wide variety of industries/facilities, includimg uranium mining and milling, other nuclear fuel cycle facilities, other NRC-licensed and DOE facilities, fossil fuel facilities, selected metal and non-metal extraction industries, and others. Where specific radioactivity control technology is lacking a description of any existing control technology is given. Future control technology is assessed in terms of improvements to equipment performance and process alterations. A catalogue of investigated research on advanced control technologies is presented

  8. Reducing windshear risk through airborne systems technology

    Science.gov (United States)

    Bowles, Roland L.

    1990-01-01

    A preliminary set of performance criteria for predictive windshear detection and warning systems is defined. Candidate airborne remote sensor technologies based on microwave Doppler radar, Doppler lidar, and IR radiometric techniques are examined from the viewpoint of overall system requirements, and the performance of each sensor is evaluated for representative microburst environments and ground clutter conditions. Preliminary simulation results indicate that all three sensors have potential for detecting windshear, and provide adequate warning time to permit flight crews to avoid the affected area or escape from the encounter.

  9. Savannah River Plant airborne emissions and controls

    International Nuclear Information System (INIS)

    Dukes, E.K.; Benjamin, R.W.

    1982-12-01

    The Savannah River Plant (SRP) was established to produce special nuclear materials, principally plutonium and tritium, for national defense needs. Major operating facilities include three nuclear reactors, two chemical separations plants, a fuel and target fabrication plant, and a heavy-water rework plant. An extensive environmental surveillance program has been maintained continuously since 1951 (before SRP startup) to determine the concentrations of radionuclides in a 1200-square-mile area centered on the plant, and the radiation exposure of the population resulting from SRP operations. This report provides data on SRP emissions, controls systems, and airborne radioactive releases. The report includes descriptions of current measurement technology. 10 references, 14 figures, 9 tables

  10. Treatment of gaseous and airborne radioactive waste

    International Nuclear Information System (INIS)

    Leichsenring, C.H.

    1982-01-01

    Gaseous and airborne radionuclides in the fuel cycle are retained in vessel off-gas filter systems and in the dissolver off-gas cleaning system. Those systems have to meet the regulatory requirements for both normal and accident conditions. From the solutions liquid aerosols are formed during liquid transfer (air lifts, steam jets) or by air sparging or by evaporation processes. During dissolution the volatile radionuclides i.e. 85 Kr, 129 I and 14 C are liberated and enter into the dissolver off-gas cleaning system. Flow sheets of different cleaning systems and their stage of development are described. (orig./RW)

  11. SOFIA's Airborne Astronomy Ambassadors: An External Evaluation of Cycle 1

    Science.gov (United States)

    Phillips, Michelle

    2015-01-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) represents a partnership between NASA and the German Aerospace Center (DLR). The observatory itself is a Boeing 747 SP that has been modified to serve as the world's largest airborne research observatory. The SOFIA Airborne Astronomy Ambassadors (AAA) program is a component of SOFIA's…

  12. Moving Target Indication for Multi-channel Airborne Radar Systems

    NARCIS (Netherlands)

    Lidicky, L.

    2010-01-01

    Moving target indication (MTI) using radar is of great interest in civil and military applications. Its uses include airborne or space-borne surveillance of ground moving vehicles (cars, trains) or ships at sea, for instance. Airborne (space-borne) radar offers several advantages when compared to

  13. Air-borne radiation from bone conduction transducers.

    Science.gov (United States)

    Lightfoot, G R

    1979-05-01

    The relative magnitudes of air-borne radiation and mechanical vibration from three types of bone conduction transducer have been measured. The study suggests that the presence of excess air-borne radiation can lead to the observation of a false air-bone gap in audiometry. Some methods of overcoming this effect are considered.

  14. Adaptive Restoration of Airborne Daedalus AADS1268 ATM Thermal Data

    International Nuclear Information System (INIS)

    D. Yuan; E. Doak; P. Guss; A. Will

    2002-01-01

    To incorporate the georegistration and restoration processes into airborne data processing in support of U.S. Department of Energy's nuclear emergency response task, we developed an adaptive restoration filter for airborne Daedalus AADS1268 ATM thermal data based on the Wiener filtering theory. Preliminary assessment shows that this filter enhances the detectability of small weak thermal anomalies in AADS1268 thermal images

  15. UAVSAR: An Airborne Window on Earth Surface Deformation

    Science.gov (United States)

    Hensley, Scott

    2011-01-01

    This study demonstrates that UAVSAR's precision autopilot and electronic steering have allowed for the reliable collection of airborne repeat pass radar interferometric data for deformation mapping. Deformation maps from temporal scales ranging from hours to months over a variety of signals of geophysical interest illustrate the utility of UAVSAR airborne repeat pass interferometry to these studies.

  16. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Exposure limits for airborne contaminants. 56... Quality and Physical Agents Air Quality § 56.5001 Exposure limits for airborne contaminants. Except as... contaminants shall not exceed, on the basis of a time weighted average, the threshold limit values adopted by...

  17. Measuring airborne microorganisms and dust from livestock houses

    NARCIS (Netherlands)

    Yang Zhao, Yang

    2011-01-01

    Airborne transmission has been suspected to be responsible for epidemics of highly infectious disease in livestock production. In such transmission, the pathogenic microorganisms may associate with dust particles. However, the extent to which airborne transmission plays a role in the

  18. OPTIMIZING THE PAKS METHOD FOR MEASURING AIRBORNE ACROLEIN

    Science.gov (United States)

    Airborne acrolein is produced from the combustion of fuel and tobacco and is of concern due to its potential for respiratory tract irritation and other adverse health effects. DNPH active-sampling is a method widely used for sampling airborne aldehydes and ketones (carbonyls); ...

  19. airborne data analysis/monitor system

    Science.gov (United States)

    Stephison, D. B.

    1981-01-01

    An Airborne Data Analysis/Monitor System (ADAMS), a ROLM 1666 computer based system installed onboard test airplanes used during experimental testing is evaluated. In addition to the 1666 computer, the ADAMS hardware includes a DDC System 90 fixed head disk and a Miltape DD400 floppy disk. Boeing designed a DMA interface to the data acquisition system and an intelligent terminal to reduce system overhead and simplify operator commands. The ADAMS software includes RMX/RTOS and both ROLM FORTRAN and assembly language are used. The ADAMS provides real time displays that enable onboard test engineers to make rapid decisions about test conduct thus reducing the cost and time required to certify new model airplanes, and improved the quality of data derived from the test, leading to more rapid development of improvements resulting in quieter, safer, and more efficient airplanes. The availability of airborne data processing removes most of the weather and geographical restrictions imposed by telemetered flight test data systems. A data base is maintained to describe the airplane, the data acquisition system, the type of testing, and the conditions under which the test is performed.

  20. Airborne fungi in an intensive care unit

    Directory of Open Access Journals (Sweden)

    C. L. Gonçalves

    2017-07-01

    Full Text Available Abstract The presence of airborne fungi in Intensive Care Unit (ICUs is associated with increased nosocomial infections. The aim of this study was the isolation and identification of airborne fungi presented in an ICU from the University Hospital of Pelotas – RS, with the attempt to know the place’s environmental microbiota. 40 Petri plates with Sabouraud Dextrose Agar were exposed to an environment of an ICU, where samples were collected in strategic places during morning and afternoon periods for ten days. Seven fungi genera were identified: Penicillium spp. (15.18%, genus with the higher frequency, followed by Aspergillus spp., Cladosporium spp., Fusarium spp., Paecelomyces spp., Curvularia spp., Alternaria spp., Zygomycetes and sterile mycelium. The most predominant fungi genus were Aspergillus spp. (13.92% in the morning and Cladosporium spp. (13.92% in the afternoon. Due to their involvement in different diseases, the identified fungi genera can be classified as potential pathogens of inpatients. These results reinforce the need of monitoring the environmental microorganisms with high frequency and efficiently in health institutions.

  1. Airborne Methane Measurements using Optical Parametric Amplifiers

    Science.gov (United States)

    Riris, H.; Numata, K.; Li, S.; Wu, S.; Ramanathan, A.; Dawsey, M.; Abshire, J. B.; Kawa, S. R.; Mao, J.

    2012-12-01

    We report on airborne methane measurements with an active sensing instrument using widely tunable, seeded optical parametric generation (OPG). Methane is a strong greenhouse gas on Earth and it is also a potential biogenic marker on Mars and other planetary bodies. Methane in the Earth's atmosphere survives for a shorter time than CO2 but its impact on climate change can be larger than CO2. Carbon and methane emissions from land are expected to increase as permafrost melts exposing millennial-age carbon stocks to respiration (aerobic-CO2 and anaerobic-CH4) and fires. Methane emissions from clathrates in the Arctic Ocean and on land are also likely to respond to climate warming. However, there is considerable uncertainty in present Arctic flux levels, as well as how fluxes will change with the changing environment and more measurements are needed. In this paper we report on an airborne demonstration of atmospheric methane column optical depth measurements at 1.65 μm using widely tunable, seeded optical parametric amplifier (OPA) and a photon counting detector. Our results show good agreement between the experimentally derived optical depth measurements and theoretical calculations and follow the expected changes for aircraft altitudes from 3 to 11 km. The technique has also been used to measure carbon dioxide and monoxide, water vapor, and other trace gases in the near and mid-infrared spectral regions on the ground.

  2. Changes to airborne pollen counts across Europe.

    Directory of Open Access Journals (Sweden)

    Chiara Ziello

    Full Text Available A progressive global increase in the burden of allergic diseases has affected the industrialized world over the last half century and has been reported in the literature. The clinical evidence reveals a general increase in both incidence and prevalence of respiratory diseases, such as allergic rhinitis (common hay fever and asthma. Such phenomena may be related not only to air pollution and changes in lifestyle, but also to an actual increase in airborne quantities of allergenic pollen. Experimental enhancements of carbon dioxide (CO[Formula: see text] have demonstrated changes in pollen amount and allergenicity, but this has rarely been shown in the wider environment. The present analysis of a continental-scale pollen data set reveals an increasing trend in the yearly amount of airborne pollen for many taxa in Europe, which is more pronounced in urban than semi-rural/rural areas. Climate change may contribute to these changes, however increased temperatures do not appear to be a major influencing factor. Instead, we suggest the anthropogenic rise of atmospheric CO[Formula: see text] levels may be influential.

  3. Precise Point Positioning in the Airborne Mode

    Science.gov (United States)

    El-Mowafy, Ahmed

    2011-01-01

    The Global Positioning System (GPS) is widely used for positioning in the airborne mode such as in navigation as a supplementary system and for geo-referencing of cameras in mapping and surveillance by aircrafts and Unmanned Aerial Vehicles (UAV). The Precise Point Positioning (PPP) approach is an attractive positioning approach based on processing of un-differenced observations from a single GPS receiver. It employs precise satellite orbits and satellite clock corrections. These data can be obtained via the internet from several sources, e.g. the International GNSS Service (IGS). The data can also broadcast from satellites, such as via the LEX signal of the new Japanese satellite system QZSS. The PPP can achieve positioning precision and accuracy at the sub-decimetre level. In this paper, the functional and stochastic mathematical modelling used in PPP is discussed. Results of applying the PPP method in an airborne test using a small fixed-wing aircraft are presented. To evaluate the performance of the PPP approach, a reference trajectory was established by differential positioning of the same GPS observations with data from a ground reference station. The coordinate results from the two approaches, PPP and differential positioning, were compared and statistically evaluated. For the test at hand, positioning accuracy at the cm-to-decimetre was achieved for latitude and longitude coordinates and doubles that value for height estimation.

  4. Handling Trajectory Uncertainties for Airborne Conflict Management

    Science.gov (United States)

    Barhydt, Richard; Doble, Nathan A.; Karr, David; Palmer, Michael T.

    2005-01-01

    Airborne conflict management is an enabling capability for NASA's Distributed Air-Ground Traffic Management (DAG-TM) concept. DAGTM has the goal of significantly increasing capacity within the National Airspace System, while maintaining or improving safety. Under DAG-TM, autonomous aircraft maintain separation from each other and from managed aircraft unequipped for autonomous flight. NASA Langley Research Center has developed the Autonomous Operations Planner (AOP), an onboard decision support system that provides airborne conflict management (ACM) and strategic flight planning support for autonomous aircraft pilots. The AOP performs conflict detection, prevention, and resolution from nearby traffic aircraft and area hazards. Traffic trajectory information is assumed to be provided by Automatic Dependent Surveillance Broadcast (ADS-B). Reliable trajectory prediction is a key capability for providing effective ACM functions. Trajectory uncertainties due to environmental effects, differences in aircraft systems and performance, and unknown intent information lead to prediction errors that can adversely affect AOP performance. To accommodate these uncertainties, the AOP has been enhanced to create cross-track, vertical, and along-track buffers along the predicted trajectories of both ownship and traffic aircraft. These buffers will be structured based on prediction errors noted from previous simulations such as a recent Joint Experiment between NASA Ames and Langley Research Centers and from other outside studies. Currently defined ADS-B parameters related to navigation capability, trajectory type, and path conformance will be used to support the algorithms that generate the buffers.

  5. Alternative analysis of airborne laser data collected within conventional multi-parameter airborne geophysical surveys

    Science.gov (United States)

    Ahl, Andreas; Supper, R.; Motschka, K.; Schattauer, I.

    2010-05-01

    For the interpretation of airborne gamma-ray spectrometry as well as airborne electromagnetics it is of great importance to determine the distance between the geophysical sensor and the ground surface. Since radar altimeters do not penetrate vegetation, laser altimeters became popular in airborne geophysics over the past years. Currently the airborne geophysical platform of the Geological Survey of Austria (GBA) is equipped with a Riegl LD90-3800VHS-FLP high resolution laser altimeter, measuring the distances according to the first and the last reflected pulse. The goal of the presented study was to explore the possibilities of deriving additional information about the survey area from the laser data and to determine the accuracy of such results. On one hand the difference between the arrival time of the first and the last reflected pulse can be used to determine the height of the vegetation. This parameter is for example important for the correction of damping effects on airborne gamma-ray measurements caused by vegetation. Moreover especially for groundwater studies at catchment scale, this parameter can also be applied to support the spatial assessment of evapotranspiration. In combination with the altitude above geoid, determined by a GPS receiver, a rough digital elevation model of the survey area can be derived from the laser altimetry. Based on a data set from a survey area in the northern part of Austria, close to the border with the Czech Republic, the reliability of such a digital elevation model and the calculated vegetation height was tested. In this study a mean deviation of -1.4m, with a standard deviation of ±3.4m, between the digital elevation model from Upper Austria (25m spatial resolution) and the determined elevation model was determined. We also found an obvious correlation between the calculated vegetation heights greater 15m and the mapped forest published by the ‘Department of Forest Inventory' of the ‘Federal Forest Office' of Austria

  6. Study of airborne science experiment management concepts for application to space shuttle, volume 2

    Science.gov (United States)

    Mulholland, D. R.; Reller, J. O., Jr.; Neel, C. B.; Haughney, L. C.

    1973-01-01

    Airborne research management and shuttle sortie planning at the Ames Research Center are reported. Topics discussed include: basic criteria and procedures for the formulation and approval of airborne missions; ASO management structure and procedures; experiment design, development, and testing aircraft characteristics and experiment interfaces; information handling for airborne science missions; mission documentation requirements; and airborne science methods and shuttle sortie planning.

  7. NASA Airborne Science Program: NASA Stratospheric Platforms

    Science.gov (United States)

    Curry, Robert E.

    2010-01-01

    The National Aeronautics and Space Administration conducts a wide variety of remote sensing projects using several unique aircraft platforms. These vehicles have been selected and modified to provide capabilities that are particularly important for geophysical research, in particular, routine access to very high altitudes, long range, long endurance, precise trajectory control, and the payload capacity to operate multiple, diverse instruments concurrently. While the NASA program has been in operation for over 30 years, new aircraft and technological advances that will expand the capabilities for airborne observation are continually being assessed and implemented. This presentation will review the current state of NASA's science platforms, recent improvements and new missions concepts as well as provide a survey of emerging technologies unmanned aerial vehicles for long duration observations (Global Hawk and Predator). Applications of information technology that allow more efficient use of flight time and the ability to rapidly reconfigure systems for different mission objectives are addressed.

  8. SOFIA'S Challenge: Scheduling Airborne Astronomy Observations

    Science.gov (United States)

    Frank, Jeremy

    2005-01-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) is NASA's next generation airborne astronomical observatory, and will commence operations in 2005. The facility consists of a 747-SP modified to accommodate a 2.5 meter telescope. SOFIA is expected to fly an average of 140 science flights per year over its 20 year lifetime. Depending on the nature of the instrument used during flight, 5-15 observations per flight are expected. The SOFIA telescope is mounted aft of the wings on the port side of the aircraft and is articulated through a range of 20deg to 60deg of elevation. The telescope has minimal lateral flexibility; thus, the aircraft must turn constantly to maintain the telescope's focus on an object during observations. A significant problem in future SOFIA operations is that of scheduling flights in support of observations. Investigators are expected to propose small numbers of observations, and many observations must be grouped together to make up single flights. Flight planning for the previous generation airborne observatory, the Kuiper Airborne Observatory (KAO), was done by hand; planners had to choose takeoff time, observations to perform, and decide on setup-actions (called "dead-legs") to position the aircraft prior to observing. This task frequently required between 6-8 hours to plan one flight The scope of the flight planning problem for supporting GI observations with the anticipated flight rate for SOFIA makes the manual approach for flight planning daunting. In response, we have designed an Automated Flight Planner (AFP) that accepts as input a set of requested observations, designated flight days, weather predictions and fuel limitations, and searches automatically for high-quality flight plans that satisfy all relevant aircraft and astronomer specified constraints. The AFP can generate one candidate flight plan in 5-10 minutes, of computation time, a feat beyond the capabilities of human flight planners. The rate at which the AFP can

  9. Composite mapping experiences in airborne gamma spectrometry

    International Nuclear Information System (INIS)

    Bucher, B.

    2014-01-01

    During an international intercomparison exercise of airborne gamma spectrometry held in Switzerland 2007 teams from Germany, France and Switzerland were proving their capabilities. One of the tasks was the composite mapping of an area around Basel. Each team was mainly covering the part of its own country at its own flying procedures. They delivered the evaluated data in a data format agreed in advance. The quantities to be delivered were also defined in advance. Nevertheless, during the process to put the data together a few questions raised: Which dose rate was meant? Had the dose rate to be delivered with or without cosmic contribution? Activity per dry or wet mass? Which coordinate system was used? Finally, the data could be put together in one map. For working procedures in case of an emergency, quantities of interest and exchange data format have to be defined in advance. But the procedures have also to be proved regularly. (author)

  10. Airborne Oceanographic Lidar (AOL) flight mission participation

    Science.gov (United States)

    Hoge, F. E.

    From February 1986 to the present, the AOL participated in six interagency flight missions. (1) Shelf Edge Exchange Processes (SEEP II) (Department of Energy). The SEEP experiments are designed to assess the assimilative capacity of the Continental Shelf to absorb the energy by-products introduced into the near-shore ocean environment from coastal communities and marine activities such as energy production plants and offshore oil operations. (2) BIOWATT II (Office of Naval Research). The major objective of this study was to provide a better understanding of the relationships between ocean physics, biology, bioluminescence, and optics in oligotrophic portions of the Atlantic Ocean. (3) Fall Experiment (FLEX) (Department of Energy). The FLEX studies were designed to determine the fate of low salinity water in the coastal boundary zone that is advected south towards the Florida coast during autumn. (4) Greenland Sea and Icelandic Marine Biological Experiments (NASA). The investigations were designed to evaluate the distribution of surface layer chlorophyll in the Greeland Sea and in the coastal waters in the vicinity of Iceland. (5) Submerged Oceanic Scattering Layer Experiment (Naval Ocean Systems Center). This flight experiment demonstrated for the first time the feasibility of detecting and metrically measuring the depth to submerged layers of particulate matter in the shelf break region and in the inner coastal zone. (6) Microbial Exchanges and Coupling in Coastal Atlantic Systems (National Science Foundation). This investigation was designed to study the transportation and fate of particulates in coastal waters and in particular the Chesapeake Bay/coastal Atlantic Ocean. Shortly after the conduct of the flight experiments, airborne laser-induced chlorophyll a and phycoerythrin fluorescence data, as well as sea surface temperature and airborne expendable bathythermograph water column temperature profiles are supplied to cooperating institutions.

  11. Data simulation of an airborne lidar system

    Science.gov (United States)

    Kim, Seongjoon; Min, Seonghong; Kim, Geunhan; Lee, Impyeong; Jun, Chulmin

    2009-05-01

    An airborne LIDAR (LIght Detection And Ranging) system can rapidly generate 3D points by densely sampling the terrain surfaces using laser pulses. The LIDAR points can be efficiently utilized for automatic reconstruction of 3D models of the objects on the terrain and the terrain itself. The data simulation of such a LIDAR system is significantly useful not only to design an optimal sensor for a specific application but also to assess data processing algorithms with various kinds of test data. In this study, we thus attempted to develop data simulation software of an airborne LIDAR system generally consisting of a GPS, an IMU and a laser scanner. We focused particularly on the geometric modeling of the sensors and the object modeling of the targets and background. Hence the data simulation software has been developed using these models. For the geometric modeling, we derived the sensor equation by modeling not only the geometric relationships between the three modules, such as a GPS, an IMU and a laser scanner but also the systematic errors associated with them. Moreover, for rapid and effective simulation, we designed the data model for both targets and background. We constructed the model data by converting the VRML formatted data into the designed model and stored these data in a 3D spatial database that can offer more effective 3D spatial indexing and query processing. Finally, we developed a program that generates simulated data along with the system parameters of a sensor, a terrain model and its trajectories over the model given.

  12. A Study of Reflected Sonic Booms Using Airborne Measurements

    Science.gov (United States)

    Kantor, Samuel R.; Cliatt, Larry J.

    2017-01-01

    In support of ongoing efforts to bring commercial supersonic flight to the public, the Sonic Booms in Atmospheric Turbulence (SonicBAT) flight test conducted at NASA Armstrong Flight Research Center. During this test, airborne sonic boom measurements were made using an instrumented TG-14 motor glider, called the Airborne Acoustic Measurement Platform (AAMP).During the flight program, the AAMP was consistently able to measure the sonic boom wave that was reflected off of the ground, in addition to the incident wave, resulting in the creation of a completely unique data set of airborne sonic boom reflection measurements.

  13. Photothermal Infrared Spectroscopy of Airborne Samples with Mechanical String Resonators

    DEFF Research Database (Denmark)

    Yamada, Shoko; Schmid, Silvan; Larsen, Tom

    2013-01-01

    -scale airborne samples. Airborne sample material is directly collected on the microstring with an efficient nondiffusion limited sampling method based on inertial impaction. Resonance frequency shifts, proportional to the absorbed heat in the microstring, are recorded as monochromatic IR light is scanned over...... the mid-infrared range. As a proof-of-concept, we sample and analyze polyvinylpyrrolidone (PVP) and the IR spectrum measured by photothermal spectroscopy matches the reference IR spectrum measured by an FTIR spectrometer. We further identify the organic surface coating of airborne TiO2 nanoparticles...

  14. NASA Langley Airborne High Spectral Resolution Lidar Instrument Description

    Science.gov (United States)

    Harper, David B.; Cook, Anthony; Hostetler, Chris; Hair, John W.; Mack, Terry L.

    2006-01-01

    NASA Langley Research Center (LaRC) recently developed the LaRC Airborne High Spectral Resolution Lidar (HSRL) to make measurements of aerosol and cloud distribution and optical properties. The Airborne HSRL has undergone as series of test flights and was successfully deployed on the Megacity Initiative: Local and Global Research Observations (MILAGRO) field mission in March 2006 (see Hair et al. in these proceedings). This paper provides an overview of the design of the Airborne HSRL and descriptions of some key subsystems unique to this instrument.

  15. Estimation of Needed Isolation Capacity for an Airborne Influenza Pandemic.

    Science.gov (United States)

    Subhash, Shobha S; Baracco, Gio; Miller, Shelly L; Eagan, Aaron; Radonovich, Lewis J

    2016-01-01

    We estimated the number of isolation beds needed to care for a surge in patients during an airborne-transmissible influenza pandemic. Based on US health system data, the amount of available airborne isolation beds needed for ill patients will be exceeded early in the course of a moderate or severe influenza pandemic, requiring medical facilities to find ways to further expand isolation bed capacity. Rather than building large numbers of permanent airborne infection isolation rooms to increase surge capacity, an investment that would come at great financial cost, it may be more prudent to prepare for wide-scale creation of just-in-time temporary negative-pressure wards.

  16. Monitoring of airborne bacteria and aerosols in different wards of hospitals - Particle counting usefulness in investigation of airborne bacteria.

    Science.gov (United States)

    Mirhoseini, Seyed Hamed; Nikaeen, Mahnaz; Khanahmd, Hossein; Hatamzadeh, Maryam; Hassanzadeh, Akbar

    2015-01-01

    The presence of airborne bacteria in hospital environments is of great concern because of their potential role as a source of hospital-acquired infections (HAI). The aim of this study was the determination and comparison of the concentration of airborne bacteria in different wards of four educational hospitals, and evaluation of whether particle counting could be predictive of airborne bacterial concentration in different wards of a hospital. The study was performed in an operating theatre (OT), intensive care unit (ICU), surgery ward (SW) and internal medicine (IM) ward of four educational hospitals in Isfahan, Iran. A total of 80 samples were analyzed for the presence of airborne bacteria and particle levels. The average level of bacteria ranged from 75-1194 CFU/m (3) . Mean particle levels were higher than class 100,000 cleanrooms in all wards. A significant correlation was observed between the numbers of 1-5 µm particles and levels of airborne bacteria in operating theatres and ICUs. The results showed that factors which may influence the airborne bacterial level in hospital environments should be properly managed to minimize the risk of HAIs especially in operating theaters. Microbial air contamination of hospital settings should be performed by the monitoring of airborne bacteria, but particle counting could be considered as a good operative method for the continuous monitoring of air quality in operating theaters and ICUs where higher risks of infection are suspected.

  17. Airborne Gravity: NGS' Gravity Data for CS06 (2012 & 2013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Texas collected in 2012 & 2013 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical...

  18. Airborne Gravity: NGS' Gravity Data for EN01 (2011)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for New York, Canada, and Lake Ontario collected in 2011 over 1 survey. This data set is part of the Gravity for the Re-definition of the...

  19. Airborne Gravity: NGS' Gravity Data for CN02 (2013 & 2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Nebraska collected in 2013 & 2014 over 3 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical...

  20. Airborne Gravity: NGS' Gravity Data for ES01 (2013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Florida, the Bahamas, and the Atlantic Ocean collected in 2013 over 1 survey. This data set is part of the Gravity for the Re-definition of...

  1. Airborne Gravity: NGS' Gravity Data for CN03 (2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Nebraska collected in 2014 over one survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

  2. CAMEX-3 AIRBORNE VERTICAL ATMOSPHERE PROFILING SYSTEM (AVAPS) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The CAMEX-3 DC-8 Airborne Vertical Atmosphere Profiling System (AVAPS) uses dropwinsonde and Global Positioning System (GPS) receivers to measure the atmospheric...

  3. CLPX Airborne Gamma Snow and Soil Moisture Surveys

    Data.gov (United States)

    National Aeronautics and Space Administration — Airborne gamma surveys were conducted over each of the three Cold Land Processes Field Experiment (CLPX) Meso-cell Study Areas (MSAs) in northern Colorado, USA,...

  4. Dispersion model for airborne radioactive particulates inside a process building

    International Nuclear Information System (INIS)

    Perkins, W.C.; Stoddard, D.H.

    1984-02-01

    An empirical model, predicting the spread of airborne radioactive particles after they are released inside a building, has been developed. The basis for this model is a composite of data for dispersion of airborne activity recorded during 12 case incidents. These incidents occurred at the Savannah River Plant (SRP) during approximately 90 plant-years of experience with the chemical and metallurgical processing of purified neptunium and plutonium. The model illustrates that the multiple-air-zone concept, used in the designs of many nuclear facilities, can be an efficient safety feature to limit the spread of airborne activity from a release. This study also provides some insight into an apparently anomalous behavior of airborne particulates, namely, their migration against the prevailing flow of ventilation air. 2 references, 12 figures, 4 tables

  5. GRIP AIRBORNE SECOND GENERATION PRECIPITATION RADAR (APR-2) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Second Generation Airborne Precipitation Radar (APR-2) is a dual-frequency (13 GHz and 35 GHz), Doppler, dual-polarization radar system. It has a downward...

  6. SMEX02 Airborne Synthetic Aperture Radar (AIRSAR) Data, Iowa

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains radar backscatter measurments taken over the Soil Moisture Experiments 2002 (SMEX02) Walnut Creek Watershed area in Iowa, USA. The Airborne...

  7. Advances and perspectives in bathymetry by airborne lidar

    Science.gov (United States)

    Zhou, Guoqing; Wang, Chenxi; Li, Mingyan; Wang, Yuefeng; Ye, Siqi; Han, Caiyun

    2015-12-01

    In this paper, the history of the airborne lidar and the development stages of the technology are reviewed. The basic principle of airborne lidar and the method of processing point-cloud data were discussed. At present, single point laser scanning method is widely used in bathymetric survey. Although the method has high ranging accuracy, the data processing and hardware system is too much complicated and expensive. For this reason, this paper present a kind of improved dual-frequency method for bathymetric and sea surface survey, in this method 176 units of 1064nm wavelength laser has been used by push-broom scanning and due to the airborne power limits still use 532nm wavelength single point for bathymetric survey by zigzag scanning. We establish a spatial coordinates for obtaining the WGS-84 of point cloud by using airborne POS system.

  8. SAFARI 2000 MODIS Airborne Simulator (MAS) Browse Images

    Data.gov (United States)

    National Aeronautics and Space Administration — The MODIS Airborne Simulator (MAS) collected imagery for the SAFARI 2000 field campaign. Currently available data consist of browse imagery and flight track...

  9. Airborne Cloud Radar (ACR) Reflectivity, Wakasa Bay, Japan

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes 94 GHz co- and cross-polarized radar reflectivity. The Airborne Cloud Radar (ACR) sensor was mounted to a NASA P-3 aircraft flown over the Sea...

  10. Experimental relations between airborne and ground measured wheat canopy temperatures

    Science.gov (United States)

    Millard, J. P.; Reginato, R. J.; Idso, S. B.; Jackson, R. D.; Goettelman, R. C.; Leroy, M. J.

    1980-01-01

    Experiments using ground-based measurements of canopy temperatures have shown that plant temperatures are good indicators of plant water stress, and thus are useful for assessing water requirements and predicting yields. An intensive 23-day airborne- and ground-measurement program was conducted in Phoenix, Arizona in 1977 to compare airborne-acquired wheat canopy temperatures with simultaneous ground measurements. For canopies that covered at least 85 percent of the soil surface, airborne measurements differed from ground measurements of plant temperature by less than 2 C. Regardless of the amount of plant cover, the airborne measurements were virtually identical to ground-nadir measurements, and thus represent a combination of plant temperature and solid background temperature.

  11. A metagenomic framework for the study of airborne microbial communities.

    Directory of Open Access Journals (Sweden)

    Shibu Yooseph

    Full Text Available Understanding the microbial content of the air has important scientific, health, and economic implications. While studies have primarily characterized the taxonomic content of air samples by sequencing the 16S or 18S ribosomal RNA gene, direct analysis of the genomic content of airborne microorganisms has not been possible due to the extremely low density of biological material in airborne environments. We developed sampling and amplification methods to enable adequate DNA recovery to allow metagenomic profiling of air samples collected from indoor and outdoor environments. Air samples were collected from a large urban building, a medical center, a house, and a pier. Analyses of metagenomic data generated from these samples reveal airborne communities with a high degree of diversity and different genera abundance profiles. The identities of many of the taxonomic groups and protein families also allows for the identification of the likely sources of the sampled airborne bacteria.

  12. CLPX Airborne Gamma Snow and Soil Moisture Surveys, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — Airborne gamma surveys were conducted over each of the three Cold Land Processes Field Experiment (CLPX) Meso-cell Study Areas (MSAs) in northern Colorado, USA,...

  13. Reconfigurable Weather Radar for Airborne Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Intelligent Automation, Inc (IAI) and its university partner, University of Oklahoma (OU), Norman, propose a forward-looking airborne environment sensor based on...

  14. APR-2 Dual-frequency Airborne Radar Observations, Wakasa Bay

    Data.gov (United States)

    National Aeronautics and Space Administration — In January and February 2003, the Airborne Second Generation Precipitation Radar (APR-2) collected data in the Wakasa Bay AMSR-E validation campaign over the sea of...

  15. SMEX02 Airborne GPS Bistatic Radar Data, Iowa

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains measurements of Global Positioning System (GPS) signals reflected from the Earth’s surface and collected on an airborne platform. The...

  16. Airborne Gravity: NGS' Gravity Data for AN03 (2010)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2010 and 2012 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

  17. Airborne Gravity: NGS' Gravity Data for PN01 (2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for California and Oregon collected in 2011 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical...

  18. Airborne Gravity: NGS' Gravity Data for AN08 (2016)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2016 over one survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

  19. Airborne Geophysical/Geological Mineral Inventory CIP Program

    National Research Council Canada - National Science Library

    1999-01-01

    The Airborne-Geophysical/Geological Mineral Inventory project is a special multi-year investment to expand the knowledge base of Alaska's mineral resources and catalyze private-sector mineral development...

  20. Airborne Wide Area Imager for Wildfire Mapping and Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An advanced airborne imaging system for fire detection/mapping is proposed. The goal of the project is to improve control and management of wildfires in order to...

  1. Airborne Gravity: NGS' Gravity Data for TS01 (2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Puerto Rico and the Virgin Islands collected in 2009 over 1 survey. This data set is part of the Gravity for the Re-definition of the...

  2. Airborne Gravity: NGS' Gravity Data for EN04 (2013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Michigan and Lake Huron collected in 2012 over 1 survey. This data set is part of the Gravity for the Re-definition of the American...

  3. Airborne Gravity: NGS' Gravity Data for EN10 (2013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for New York, Pennsylvania, New Jersey, Connecticut and the Atlantic Ocean collected in 2013 over 1 survey. This data set is part of the...

  4. Airborne Gravity: NGS' Gravity Data for EN09 (2016)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Massachusetts, Connecticut, Rhode Island, New Hampshire, New York, and the Atlantic Ocean collected in 2012 over 1 survey. This data set is...

  5. Miniaturized Airborne Imaging Central Server System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a miniaturized airborne imaging central server system (MAICSS). MAICSS is designed as a high-performance-computer-based electronic backend that...

  6. Miniaturized Airborne Imaging Central Server System, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a miniaturized airborne imaging central server system (MAICSS). MAICSS is designed as a high-performance computer-based electronic backend that...

  7. CAMEX-3 AIRBORNE VERTICAL ATMOSPHERE PROFILING SYSTEM (AVAPS) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The CAMEX-3 DC-8 Airborne Vertical Atmosphere Profiling System (AVAPS) uses dropwindsonde and Global Positioning System (GPS) receivers to measure the atmospheric...

  8. Thermal Mapping Airborne Simulator for Small Satellite Sensor, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — A high performance, inexpensive, airborne simulator that will serve as the prototype for a small satellite based imaging system capable of mapping thermal anomalies...

  9. TCSP ER-2 MODIS AIRBORNE SIMULATOR (MAS) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The MODIS Airborne Simulator (MAS) is a multi-spectral line-scanner system that acquires image data in 50 spectral bands over wavelengths ranging from 0.46 to 14.3...

  10. A Metagenomic Framework for the Study of Airborne Microbial Communities

    OpenAIRE

    Yooseph, Shibu; Andrews-Pfannkoch, Cynthia; Tenney, Aaron; McQuaid, Jeff; Williamson, Shannon; Thiagarajan, Mathangi; Brami, Daniel; Zeigler-Allen, Lisa; Hoffman, Jeff; Goll, Johannes B.; Fadrosh, Douglas; Glass, John; Adams, Mark D.; Friedman, Robert; Venter, J. Craig

    2013-01-01

    Understanding the microbial content of the air has important scientific, health, and economic implications. While studies have primarily characterized the taxonomic content of air samples by sequencing the 16S or 18S ribosomal RNA gene, direct analysis of the genomic content of airborne microorganisms has not been possible due to the extremely low density of biological material in airborne environments. We developed sampling and amplification methods to enable adequate DNA recovery to allow m...

  11. [Relationships between air conditioning, airborne microorganisms and health].

    Science.gov (United States)

    Parat, S; Perdrix, A; Baconnier, P

    1999-01-01

    Concurrently with the increase of air-conditioning, potentially severe or frequent new diseases have emerged, giving rise to social and economical consequences. The first part of this work is a state of the art review of the relationships between air-conditioning, airborne microorganisms and health, through a technical, metrological and medical approach. The second part presents four studies performed in this field. Two of them deal with the relationship between airborne microorganisms and technical features of air-conditioning. Measurements performed on actual sites demonstrated the benefit of using high efficiency filters and low risk components in air-conditioning systems. The third study was aimed to look for a relationship between airborne microorganisms and sick building syndrome symptoms. Statistical analyses of individual data revealed significant associations between airborne bacteria or fungi and symptoms. These results may be the first step in determining a dose-response relationship, in order to define threshold limit values in this field. In the fourth study, the contribution of particle counting in assessing exposure to airborne microorganisms was explored by monitoring simultaneous variations of microbial and particle concentrations. The results showed that associating particle counting may allow to detect microbial variations instantaneously, and therefore improve the assessment of exposure to airborne microorganisms.

  12. Miniaturized Airborne Imaging Central Server System

    Science.gov (United States)

    Sun, Xiuhong

    2011-01-01

    In recent years, some remote-sensing applications require advanced airborne multi-sensor systems to provide high performance reflective and emissive spectral imaging measurement rapidly over large areas. The key or unique problem of characteristics is associated with a black box back-end system that operates a suite of cutting-edge imaging sensors to collect simultaneously the high throughput reflective and emissive spectral imaging data with precision georeference. This back-end system needs to be portable, easy-to-use, and reliable with advanced onboard processing. The innovation of the black box backend is a miniaturized airborne imaging central server system (MAICSS). MAICSS integrates a complex embedded system of systems with dedicated power and signal electronic circuits inside to serve a suite of configurable cutting-edge electro- optical (EO), long-wave infrared (LWIR), and medium-wave infrared (MWIR) cameras, a hyperspectral imaging scanner, and a GPS and inertial measurement unit (IMU) for atmospheric and surface remote sensing. Its compatible sensor packages include NASA s 1,024 1,024 pixel LWIR quantum well infrared photodetector (QWIP) imager; a 60.5 megapixel BuckEye EO camera; and a fast (e.g. 200+ scanlines/s) and wide swath-width (e.g., 1,920+ pixels) CCD/InGaAs imager-based visible/near infrared reflectance (VNIR) and shortwave infrared (SWIR) imaging spectrometer. MAICSS records continuous precision georeferenced and time-tagged multisensor throughputs to mass storage devices at a high aggregate rate, typically 60 MB/s for its LWIR/EO payload. MAICSS is a complete stand-alone imaging server instrument with an easy-to-use software package for either autonomous data collection or interactive airborne operation. Advanced multisensor data acquisition and onboard processing software features have been implemented for MAICSS. With the onboard processing for real time image development, correction, histogram-equalization, compression, georeference, and

  13. The Origin And Spread Of Airborne Bacteria

    Science.gov (United States)

    Henderson-Begg, S. K.; Moffett, B. F.

    2009-12-01

    wind speed and direction, marine organisms would have been airborne for at least 16 hours in the Thursley sample and for at least 4 hours in the East London sample. The origin and spread of airborne organisms warrants further investigation.

  14. HIGH RESOLUTION AIRBORNE SHALLOW WATER MAPPING

    Directory of Open Access Journals (Sweden)

    F. Steinbacher

    2012-07-01

    Full Text Available In order to meet the requirements of the European Water Framework Directive (EU-WFD, authorities face the problem of repeatedly performing area-wide surveying of all kinds of inland waters. Especially for mid-sized or small rivers this is a considerable challenge imposing insurmountable logistical efforts and costs. It is therefore investigated if large-scale surveying of a river system on an operational basis is feasible by employing airborne hydrographic laser scanning. In cooperation with the Bavarian Water Authority (WWA Weilheim a pilot project was initiated by the Unit of Hydraulic Engineering at the University of Innsbruck and RIEGL Laser Measurement Systems exploiting the possibilities of a new LIDAR measurement system with high spatial resolution and high measurement rate to capture about 70 km of riverbed and foreland for the river Loisach in Bavaria/Germany and the estuary and parts of the shoreline (about 40km in length of lake Ammersee. The entire area surveyed was referenced to classic terrestrial cross-section surveys with the aim to derive products for the monitoring and managing needs of the inland water bodies forced by the EU-WFD. The survey was performed in July 2011 by helicopter and airplane and took 3 days in total. In addition, high resolution areal images were taken to provide an optical reference, offering a wide range of possibilities on further research, monitoring, and managing responsibilities. The operating altitude was about 500 m to maintain eye-safety, even for the aided eye, the airspeed was about 55 kts for the helicopter and 75 kts for the aircraft. The helicopter was used in the alpine regions while the fixed wing aircraft was used in the plains and the urban area, using appropriate scan rates to receive evenly distributed point clouds. The resulting point density ranged from 10 to 25 points per square meter. By carefully selecting days with optimum water quality, satisfactory penetration down to the river

  15. Evaluation of principal cannabinoids in airborne particulates

    International Nuclear Information System (INIS)

    Balducci, C.; Nervegna, G.; Cecinato, A.

    2009-01-01

    The determination of delta(9)-tetrahydrocannabinol (Δ 9 -THC), cannabidiol (CND) and cannabinol (CNB), primary active components in cannabis preparation, was carried out on airborne particulates by applying a specific procedure consisting of soot extraction by ultrasonic bath, purification by solvent partitioning, derivatization with N-(t-butyldimethylsilyl)-N-methyl-trifluoroacetamide, and separation/detection through gas chromatography coupled with tandem mass spectrometry. The optimized procedure was found suitable for measuring the three psychotropic substances at concentrations ranging from ca. 0.001 to ca. 5.0 ng cm -3 of air, with recoveries always higher than 82%, accuracy >7.3% and precision >90%. Application of the procedure performed on field in Rome and Bari, Italy, demonstrated that all three compounds contaminate the air in Italian cities whereas in Algiers, Algeria, only cannabinol, the most stable in the atmosphere, exceeded the limit of quantification of the method. The relative percentages of the three cannabinoids in general reproduced those typical of the Cannabis sativa plant and were very different from those found in human blood, urine and sweat.

  16. Evaluation of principal cannabinoids in airborne particulates

    Energy Technology Data Exchange (ETDEWEB)

    Balducci, C., E-mail: balducci@iia.cnr.it [Italian National Research Council, Institute for Atmospheric Pollution (CNR-IIA), Monterotondo Stazione (Italy); Nervegna, G.; Cecinato, A. [Italian National Research Council, Institute for Atmospheric Pollution (CNR-IIA), Monterotondo Stazione (Italy)

    2009-05-08

    The determination of delta(9)-tetrahydrocannabinol ({Delta}{sup 9}-THC), cannabidiol (CND) and cannabinol (CNB), primary active components in cannabis preparation, was carried out on airborne particulates by applying a specific procedure consisting of soot extraction by ultrasonic bath, purification by solvent partitioning, derivatization with N-(t-butyldimethylsilyl)-N-methyl-trifluoroacetamide, and separation/detection through gas chromatography coupled with tandem mass spectrometry. The optimized procedure was found suitable for measuring the three psychotropic substances at concentrations ranging from ca. 0.001 to ca. 5.0 ng cm{sup -3} of air, with recoveries always higher than 82%, accuracy >7.3% and precision >90%. Application of the procedure performed on field in Rome and Bari, Italy, demonstrated that all three compounds contaminate the air in Italian cities whereas in Algiers, Algeria, only cannabinol, the most stable in the atmosphere, exceeded the limit of quantification of the method. The relative percentages of the three cannabinoids in general reproduced those typical of the Cannabis sativa plant and were very different from those found in human blood, urine and sweat.

  17. Does airborne nickel exposure induce nickel sensitization?

    Science.gov (United States)

    Mann, Eugen; Ranft, Ulrich; Eberwein, Georg; Gladtke, Dieter; Sugiri, Dorothee; Behrendt, Heidrun; Ring, Johannes; Schäfer, Torsten; Begerow, Jutta; Wittsiepe, Jürgen; Krämer, Ursula; Wilhelm, Michael

    2010-06-01

    Nickel is one of the most prevalent causes of contact allergy in the general population. This study focuses on human exposure to airborne nickel and its potential to induce allergic sensitization. The study group consisted of 309 children at school-starter age living in the West of Germany in the vicinity of two industrial sources and in a rural town without nearby point sources of nickel. An exposure assessment of nickel in ambient air was available for children in the Ruhr district using routinely monitored ambient air quality data and dispersion modelling. Internal nickel exposure was assessed by nickel concentrations in morning urine samples of the children. The observed nickel sensitization prevalence rates varied between 12.6% and 30.7%. Statistically significant associations were showed between exposure to nickel in ambient air and urinary nickel concentration as well as between urinary nickel concentration and nickel sensitization. Furthermore, an elevated prevalence of nickel sensitization was associated with exposure to increased nickel concentrations in ambient air. The observed associations support the assumption that inhaled nickel in ambient air might be a risk factor for nickel sensitization; further studies in larger collectives are necessary.

  18. Airborne silica levels in an urban area

    Energy Technology Data Exchange (ETDEWEB)

    De Berardis, B. [Dipartimento di Tecnologie e Salute, Istituto Superiore di Sanita, Viale Regina Elena, 299, 00161 Rome (Italy)]. E-mail: barbara.deberardis@iss.it; Incocciati, E. [CONTARP Consulenza Tecnica Accertamento Rischi e Prevenzione, INAIL Direzione Generale, 00143 Rome (Italy); Massera, S. [CONTARP Consulenza Tecnica Accertamento Rischi e Prevenzione, INAIL Direzione Generale, 00143 Rome (Italy); Gargaro, G. [CONTARP Consulenza Tecnica Accertamento Rischi e Prevenzione, INAIL Direzione Generale, 00143 Rome (Italy); Paoletti, L. [Dipartimento di Tecnologie e Salute, Istituto Superiore di Sanita, Viale Regina Elena, 299, 00161 Rome (Italy)

    2007-09-01

    In order to evaluate the exposure levels of the general population we studied the concentrations of silica particles in the inhalable particulate fraction (PM10) in different meteorological-climate periods in an urban area of Rome. In order to determine the concentration and the granulometric spectrum of silica particles, PM10 sampled by a cascade impactor was analysed by X-ray diffractometry (XRD) and by scanning electron microscopy equipped with a thin-window system for X-ray microanalysis (SEM/EDX). Over the period September 2004-October 2005 the abundance of silica particles as evaluated by SEM/EDX ranged from 1.6 to 10.4% of the total PM10 particulate, with a weight concentration of free crystalline silica, evaluated by XRD, in the range 0.25-2.87 {mu}g/m{sup 3}. The mean diameter of silica particles ranged from 0.3 to 10.5 {mu}m, with more than 87% of particles having a diameter of less than 2.5 {mu}m. The correlations between SEM/EDX and XRD data seem to suggest that the airborne silica particles in the urban location studied were mainly in the form crystalline silica. A strong relationship was found between the meteorological-climate conditions and the concentration level of free crystalline silica. This result suggests that the Southern winds from the Sahara desert carry an important amount of silica particles into Mediterranean Europe.

  19. Robust automatic camera pointing for airborne surveillance

    Science.gov (United States)

    Dwyer, David; Wren, Lee; Thornton, John; Bonsor, Nigel

    2002-08-01

    Airborne electro-optic surveillance from a moving platform currently requires regular interaction from a trained operator. Even simple tasks such as fixating on a static point on the ground can demand constant adjustment of the camera orientation to compensate for platform motion. In order to free up operator time for other tasks such as navigation and communication with ground assets, an automatic gaze control system is needed. This paper describes such a system, based purely on tracking points within the video image. A number of scene points are automatically selected and their inter-frame motion tracked. The scene motion is then estimated using a model of a planar projective transform. For reliable and accurate camera pointing, the modeling of the scene motion must be robust to common problems such as scene point obscuration, objects moving independently within the scene and image noise. This paper details a COTS based system for automatic camera fixation and describes ways of preventing objects moving in the scene or poor motion estimates from corrupting the scene motion model.

  20. Diversity and seasonal dynamics of airborne archaea

    Science.gov (United States)

    Fröhlich-Nowoisky, J.; Ruzene Nespoli, C.; Pickersgill, D. A.; Galand, P. E.; Müller-Germann, I.; Nunes, T.; Gomes Cardoso, J.; Almeida, S. M.; Pio, C.; Andreae, M. O.; Conrad, R.; Pöschl, U.; Després, V. R.

    2014-11-01

    Archaea are widespread and abundant in many terrestrial and aquatic environments, and are thus outside extreme environments, accounting for up to ~10% of the prokaryotes. Compared to bacteria and other microorganisms, however, very little is known about the abundance, diversity, and dispersal of archaea in the atmosphere. By means of DNA analysis and Sanger sequencing targeting the 16S rRNA (435 sequences) and amoA genes in samples of air particulate matter collected over 1 year at a continental sampling site in Germany, we obtained first insights into the seasonal dynamics of airborne archaea. The detected archaea were identified as Thaumarchaeota or Euryarchaeota, with soil Thaumarchaeota (group I.1b) being present in all samples. The normalized species richness of Thaumarchaeota correlated positively with relative humidity and negatively with temperature. This together with an increase in bare agricultural soil surfaces may explain the diversity peaks observed in fall and winter. The detected Euryarchaeota were mainly predicted methanogens with a low relative frequency of occurrence. A slight increase in their frequency during spring may be linked to fertilization processes in the surrounding agricultural fields. Comparison with samples from the Cape Verde islands (72 sequences) and from other coastal and continental sites indicates that the proportions of Euryarchaeota are enhanced in coastal air, which is consistent with their suggested abundance in marine surface waters. We conclude that air transport may play an important role in the dispersal of archaea, including assumed ammonia-oxidizing Thaumarchaeota and methanogens.

  1. A 3D airborne ultrasound scanner

    Science.gov (United States)

    Capineri, L.; Masotti, L.; Rocchi, S.

    1998-06-01

    This work investigates the feasibility of an ultrasound scanner designed to reconstruct three-dimensional profiles of objects in air. There are many industrial applications in which it is important to obtain quickly and accurately the digital reconstruction of solid objects with contactless methods. The final aim of this project was the profile reconstruction of shoe lasts in order to eliminate the mechanical tracers from the reproduction process of shoe prototypes. The feasibility of an ultrasonic scanner was investigated in laboratory conditions on wooden test objects with axial symmetry. A bistatic system based on five airborne polyvinylidenedifluoride (PVDF) transducers was mechanically moved to emulate a cylindrical array transducer that can host objects of maximum width and height 20 cm and 40 cm respectively. The object reconstruction was based on a simplified version of the synthetic aperture focusing technique (SAFT): the time of flight (TOF) of the first in time echo for each receiving transducer was taken into account, a coarse spatial sampling of the ultrasonic field reflected on the array transducer was delivered and the reconstruction algorithm was based on the ellipsoidal backprojection. Measurements on a wooden cone section provided submillimetre accuracy in a controlled environment.

  2. RADIOMETRIC CALIBRATION OF AIRBORNE LASER SCANNING DATA

    Directory of Open Access Journals (Sweden)

    Pilarska Magdalena

    2016-12-01

    Full Text Available Airborne laser scanning (ALS is widely used passive remote sensing technique. The radiometric calibration of ALS data is presented in this article. This process is a necessary element in data processing since it eliminates the influence of the external factors on the obtained values of radiometric features such as range and incidence angle. The datasets were captured with three different laser scanners; since each of these operates at a different wavelength (532, 106 4 and 1550 nm this makes the experiment more interesting. Radiometric calibration is a complex process, and a short theoretical background is therefore provided at the beginning of the article. The applied calibration procedure relies on areas with known reflectivity . The calibration region s should exhibit s table radiometric properties, therefore asphalt is used to calibrate each dataset and calculate a calibration constant for each flight block (wavelength independently . Following this, the results of radiometric calibration , reflectance and backscattering coefficient, are presented and discussed in detail. Finally, the obtained reflectance values are compared with spectral characteristics. It could be shown that the reflectance values which result from radiometric calibration are similar to values presented on spectral characteristics.

  3. Airborne effluent control at uranium mills

    International Nuclear Information System (INIS)

    Sears, M.B.

    1976-01-01

    The Oak Ridge National Laboratory has made an engineering cost--environmental benefit study of radioactive waste treatment systems for decreasing the amount of radioactive materials released from uranium ore processing mills. This paper summarizes the results of the study which pertain to the control and/or abatement of airborne radioactive materials from the mill processes. The tailings area is not included. Present practices in the uranium milling industry, with particular emphasis on effluent control and waste management, have been surveyed. A questionnaire was distributed to each active mill in the United States. Replies were received from about 75 percent of the mill operators. Visits were made to six operating uranium mills that were selected because they represented the different processes in use today and the newest, most modern in mill designs. Discussions were held with members of the Region IV Office of NRC and the Grand Junction Office of ERDA. Nuclear Science Abstracts, as well as other sources, were searched for literature pertinent to uranium mill processes, effluent control, and waste management

  4. Airborne radiometric: Data evaluation and calibration

    International Nuclear Information System (INIS)

    Wendt, I.; Sengpiel, K.P.; Lenz, H.

    1984-01-01

    The airborne geophysical system of the BGR (German Geological Survey) consists of a helicopter equipped with an electromagnetic system with two transmittors and two receivers, a proton resonance magnetometer and a 16 L NaJ-crystal with four channel recording. All these data together with navigation data and flight altitude above ground are recorded each second on a nine track magnetic tape for further data evaluation. Different corrections have to be applied to the rough data such as: smoothing by means of a digital filter to reduce statistical noise, altitude correction, Compton-correction, and drift correction (cross-profile evaluation). Then the corrected measuring data are combined with the navigation data in order to be able to produce iso-line maps. The final results are presented as: line plots for U, Th, and K (and EM-data and magnetometer data); actual flight line plots; iso-line maps for U, Th, and K; iso-line maps for conductivity; depth of conducting layer; and magnetometry maps. The procedures of correction and evaluation of the above mentioned data as well as the calibration of the NaJ-detector in terms of ppm U, Th, and %K are dicussed in the paper. (author)

  5. Composite mapping experiences in airborne gamma spectrometry.

    Science.gov (United States)

    Bucher, B

    2014-08-01

    During an international intercomparison exercise of airborne gamma spectrometry held in Switzerland 2007 teams from Germany, France and Switzerland were proving their capabilities. One of the tasks was the composite mapping of an area around Basel. Each team was mainly covering the part of its own country at its own flying procedures. They delivered the evaluated data in a data format agreed in advance. The quantities to be delivered were also defined in advance. Nevertheless, during the process to put the data together a few questions raised: Which dose rate was meant? Had the dose rate to be delivered with or without cosmic contribution? Activity per dry or wet mass? Which coordinate system was used? Finally, the data could be put together in one map. For working procedures in case of an emergency, quantities of interest and exchange data format have to be defined in advance. But the procedures have also to be proved regularly. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Open Source Software Reuse in the Airborne Cloud Computing Environment

    Science.gov (United States)

    Khudikyan, S. E.; Hart, A. F.; Hardman, S.; Freeborn, D.; Davoodi, F.; Resneck, G.; Mattmann, C. A.; Crichton, D. J.

    2012-12-01

    Earth science airborne missions play an important role in helping humans understand our climate. A challenge for airborne campaigns in contrast to larger NASA missions is that their relatively modest budgets do not permit the ground-up development of data management tools. These smaller missions generally consist of scientists whose primary focus is on the algorithmic and scientific aspects of the mission, which often leaves data management software and systems to be addressed as an afterthought. The Airborne Cloud Computing Environment (ACCE), developed by the Jet Propulsion Laboratory (JPL) to support Earth Science Airborne Program, is a reusable, multi-mission data system environment for NASA airborne missions. ACCE provides missions with a cloud-enabled platform for managing their data. The platform consists of a comprehensive set of robust data management capabilities that cover everything from data ingestion and archiving, to algorithmic processing, and to data delivery. Missions interact with this system programmatically as well as via browser-based user interfaces. The core components of ACCE are largely based on Apache Object Oriented Data Technology (OODT), an open source information integration framework at the Apache Software Foundation (ASF). Apache OODT is designed around a component-based architecture that allows for selective combination of components to create highly configurable data management systems. The diverse and growing community that currently contributes to Apache OODT fosters on-going growth and maturation of the software. ACCE's key objective is to reduce cost and risks associated with developing data management systems for airborne missions. Software reuse plays a prominent role in mitigating these problems. By providing a reusable platform based on open source software, ACCE enables airborne missions to allocate more resources to their scientific goals, thereby opening the doors to increased scientific discovery.

  7. Elementary analysis of airborne dust (preliminary findings of the AFR Coordinated Airborne Dust Programme (LVPr))

    International Nuclear Information System (INIS)

    1983-03-01

    In March 1981 the systematic measuring of 15 elements of airborne dust was started in the Coordinated Airborne Dust Program (LVPr) by the Association for the Promotion of Radionuclide Technology (AFR). The sampling was done under comparable conditions at five selected places within the Federal Republic of Germany by using especially developed large-filter High Volume Samplers. The aim of this research is to establish the foundation for further investigations on the effects of the current given element concentrations on human life. When the results of the first half-year (summer period) were in hand, these element concentrations, which had been analysed using different methods, were presented to a group of experts, also with the experience gained with the analytical methods, in order to critically assess procedure and philosophy of this study. This evaluation was done on the occasion of a colloquium on Jun 29th, 1982 at the Karlsruhe Nuclear Research Centre. The presented AFR-Report contains the papers and the discussions of this meeting as well as the average element data with respect to the sampling time between 15th and 40th week of the year 1981. The discussion contributions presented here correspond to the essential statements that have been given and recorded. A total classification of all data relating to the whole sampling time of the LVPr will be given in AFR-Report No. 007. (orig.) [de

  8. Monitoring of airborne bacteria and aerosols in different wards of hospitals – Particle counting usefulness in investigation of airborne bacteria

    Directory of Open Access Journals (Sweden)

    Seyed Hamed Mirhoseini

    2015-12-01

    Full Text Available [b]Introduction and objective[/b]. The presence of airborne bacteria in hospital environments is of great concern because of their potential role as a source of hospital-acquired infections (HAI. The aim of this study was the determination and comparison of the concentration of airborne bacteria in different wards of four educational hospitals, and evaluation of whether particle counting could be predictive of airborne bacterial concentration in different wards of a hospital. [b]Materials and method.[/b] The study was performed in an operating theatre (OT, intensive care unit (ICU, surgery ward (SW and internal medicine (IM ward of four educational hospitals in Isfahan, Iran. A total of 80 samples were analyzed for the presence of airborne bacteria and particle levels. [b]Results.[/b] The average level of bacteria ranged from 75–1194 CFU/m [sup]3[/sup] . Mean particle levels were higher than class 100,000 cleanrooms in all wards. A significant correlation was observed between the numbers of 1–5 µm particles and levels of airborne bacteria in operating theatres and ICUs. The results showed that factors which may influence the airborne bacterial level in hospital environments should be properly managed to minimize the risk of HAIs especially in operating theaters. [b]Conclusions.[/b] Microbial air contamination of hospital settings should be performed by the monitoring of airborne bacteria, but particle counting could be considered as a good operative method for the continuous monitoring of air quality in operating theaters and ICUs where higher risks of infection are suspected.

  9. Airborne Sea of Dust over China

    Science.gov (United States)

    2002-01-01

    TDust covered northern China in the last week of March during some of the worst dust storms to hit the region in a decade. The dust obscuring China's Inner Mongolian and Shanxi Provinces on March 24, 2002, is compared with a relatively clear day (October 31, 2001) in these images from the Multi-angle Imaging SpectroRadiometer's vertical-viewing (nadir) camera aboard NASA's Terra satellite. Each image represents an area of about 380 by 630 kilometers (236 by 391 miles). In the image from late March, shown on the right, wave patterns in the yellowish cloud liken the storm to an airborne ocean of dust. The veil of particulates obscures features on the surface north of the Yellow River (visible in the lower left). The area shown lies near the edge of the Gobi desert, a few hundred kilometers, or miles, west of Beijing. Dust originates from the desert and travels east across northern China toward the Pacific Ocean. For especially severe storms, fine particles can travel as far as North America. The Multi-angle Imaging SpectroRadiometer, built and managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., is one of five Earth-observing instruments aboard the Terra satellite, launched in December 1999. The instrument acquires images of Earth at nine angles simultaneously, using nine separate cameras pointed forward, downward and backward along its flight path. The change in reflection at different view angles affords the means to distinguish different types of atmospheric particles, cloud forms and land surface covers. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team

  10. Forest Delineation Based on Airborne LIDAR Data

    Directory of Open Access Journals (Sweden)

    Norbert Pfeifer

    2012-03-01

    Full Text Available The delineation of forested areas is a critical task, because the resulting maps are a fundamental input for a broad field of applications and users. Different national and international forest definitions are available for manual or automatic delineation, but unfortunately most definitions lack precise geometrical descriptions for the different criteria. A mandatory criterion in forest definitions is the criterion of crown coverage (CC, which defines the proportion of the forest floor covered by the vertical projection of the tree crowns. For loosely stocked areas, this criterion is especially critical, because the size and shape of the reference area for calculating CC is not clearly defined in most definitions. Thus current forest delineations differ and tend to be non-comparable because of different settings for checking the criterion of CC in the delineation process. This paper evaluates a new approach for the automatic delineation of forested areas, based on airborne laser scanning (ALS data with a clearly defined method for calculating CC. The new approach, the ‘tree triples’ method, is based on defining CC as a relation between the sum of the crown areas of three neighboring trees and the area of their convex hull. The approach is applied and analyzed for two study areas in Tyrol, Austria. The selected areas show a loosely stocked forest at the upper timberline and a fragmented forest on the hillside. The fully automatic method presented for delineating forested areas from ALS data shows promising results with an overall accuracy of 96%, and provides a beneficial tool for operational applications.

  11. Airborne DOAS in South Africa: escaping flatland

    Science.gov (United States)

    Broccardo, S. P.; Heue, K.; Piketh, S.; Platt, U.

    2010-12-01

    The satellite instruments SCIAMACHY, OMI and GOME-2 show high average tropospheric NO2 vertical column densities over the South African Highveld, a region with a high density of coal-fired power stations and other heavy industries. A pushbroom-imaging DOAS spectrometer was flown over the Highveld and surrounding areas in order to further investigate this feature of the satellite record. The wavelength range of the instrument includes differential absorption structures of gases relevant to air quality such as NO2 and SO2. The high spatial resolution of the instrument allows individual sources to be distinguished, while the mobility of the airborne platform allows larger-scale measurements to be made. Emissions fluxes for individual facilities are calculated. An NO flux for the city of Johannesburg is derived from the nadir DOAS column measurements. Similarly, a flux for the entire Highveld region is derived and compared to a satellite-derived flux. The Highveld provides an excellent outdoor laboratory for development of trace-gas remote sensing instrumentation. The greater Johannesburg conurbation and nearby industrial point sources are surrounded by rural areas for several hundred kilometers on all sides. Flat topography and a stable atmosphere in winter lead to plumes with high trace-gas concentrations that are easy to measure and distinguish from the background. A lightweight scanning multi-axis spectrometer is being built to measure industrial plumes from an ultra-light aircraft. Using a tomographic inversion, this instrument will give a vertical cross-section of the plume, allowing validation of dispersion models and direct comparison with in-situ measurements. Using a suitable flight path, a three dimensional representation of the plume can be built up.

  12. Recent advances in airborne radiometric technology

    International Nuclear Information System (INIS)

    Jobst, J.E.

    1985-01-01

    Since its inception, the DOE Remote Sensing Laboratory has made dramatic innovations in airborne radiometric technology. In the past few years there have been at least four major changes in operational philosophy. (1) The helicopter is now the prime radiation survey vehicle. Surveys are conducted at low speed and low altitude, with lines spaced only a few hundred feet apart. Radiation anomalies and subtle changes in background can be readily identified. (2) Much greater emphasis is now placed on accurate, detailed analysis and interpretation of radiation data. Dramatic improvements in survey hardware and software provide much more data of considerably better quality. (3) Recent Laboratory research has been concentrated on error-free, positive identification of point radiation sources. In the past, the extent and magnitude of dispersed sources were the major concerns. (4) Integrated remote sensing has been strongly emphasized at the Laboratory in recent years. This involves the simultaneous use of radiation detectors, aerial cameras, and the multispectral scanner imagery. The synergistic effects of such data correlation are of significantly greater value in analyzing the terrestrial environment. Many of the changes in operational philosophy are directly traceable to new or dramatically improved hardware and software employed at the Laboratory. Six items have been instrumental in the above technological advances: (1) the UHF Transponder System and its predecessor, the Microwave Ranging System; (2) Model IC of the REDAR data acquisition system; (3) the development of the search algorithm; (4) continued improvements in the REDACA data analysis system; (5) deployment of polyscin sodium iodide radiation detectors; and (6) development of the Graphic Overview System

  13. Modelling airborne dispersion for disaster management

    Science.gov (United States)

    Musliman, I. A.; Yohnny, L.

    2017-05-01

    Industrial disasters, like any other disasters, can happen anytime, anywhere and in any form. Airborne industrial disaster is a kind of catastrophic event involving the release of particles such as chemicals and industrial wastes into environment in gaseous form, for instance gas leakages. Unlike solid and liquid materials, gases are often colourless and odourless, the particles are too tiny to be visible to the naked eyes; hence it is difficult to identify the presence of the gases and to tell the dispersion and location of the substance. This study is to develop an application prototype to perform simulation modelling on the gas particles to determine the dispersion of the gas particles and to identify the coverage of the affected area. The prototype adopted Lagrangian Particle Dispersion (LPD) model to calculate the position of the gas particles under the influence of wind and turbulent velocity components, which are the induced wind due to the rotation of the Earth, and Convex Hull algorithm to identify the convex points of the gas cloud to form the polygon of the coverage area. The application performs intersection and overlay analysis over a set of landuse data at Pasir Gudang, Johor industrial and residential area. Results from the analysis would be useful to tell the percentage and extent of the affected area, and are useful for the disaster management to evacuate people from the affected area. The developed application can significantly increase efficiency of emergency handling during a crisis. For example, by using a simulation model, the emergency handling can predict what is going to happen next, so people can be well informed and preparations works can be done earlier and better. Subsequently, this application helps a lot in the decision making process.

  14. Modelling airborne dispersion for disaster management

    International Nuclear Information System (INIS)

    Musliman, I A; Yohnny, L

    2017-01-01

    Industrial disasters, like any other disasters, can happen anytime, anywhere and in any form. Airborne industrial disaster is a kind of catastrophic event involving the release of particles such as chemicals and industrial wastes into environment in gaseous form, for instance gas leakages. Unlike solid and liquid materials, gases are often colourless and odourless, the particles are too tiny to be visible to the naked eyes; hence it is difficult to identify the presence of the gases and to tell the dispersion and location of the substance. This study is to develop an application prototype to perform simulation modelling on the gas particles to determine the dispersion of the gas particles and to identify the coverage of the affected area. The prototype adopted Lagrangian Particle Dispersion (LPD) model to calculate the position of the gas particles under the influence of wind and turbulent velocity components, which are the induced wind due to the rotation of the Earth, and Convex Hull algorithm to identify the convex points of the gas cloud to form the polygon of the coverage area. The application performs intersection and overlay analysis over a set of landuse data at Pasir Gudang, Johor industrial and residential area. Results from the analysis would be useful to tell the percentage and extent of the affected area, and are useful for the disaster management to evacuate people from the affected area. The developed application can significantly increase efficiency of emergency handling during a crisis. For example, by using a simulation model, the emergency handling can predict what is going to happen next, so people can be well informed and preparations works can be done earlier and better. Subsequently, this application helps a lot in the decision making process. (paper)

  15. Current technology in sampling for airborne radionuclides

    International Nuclear Information System (INIS)

    Schulte, H.F.

    1976-01-01

    Sampling for airborne radionuclides is an important part of assessing the occupational environment and that of the public or out-plant environment. Both of these are important to the operation of any nuclear facility. Most such facilities do not emit radionuclides continuously to any extent and hence both the occupational and environmental sampling system is designed to detect deviations from normal conditions or untoward events. Work with materials of a low degree of radioactivity or with nonradioactive materials may involve operations which are not enclosed and significant contaminating material may always exist in the air. In this case, the sampling is directed toward measuring this ambient level and assessing its continued impact on the worker and on the environment. Publication No. 12 of the International Commission on Radiological Protection specifies the types of operations where sampling is necessary for worker protection and the American National Standards Institute publication N 13.1-1969 is a guide to the methods used. Increasingly, this field is covered by various regulations which specify when sampling must be done and, in some cases, how it shall be done. These include requirements of the Occupational Safety and Health Administration, the Nuclear Regulatory Commission, and the Environmental Protection Agency. Needless to say, where these have specified methods they must be followed although in most cases exact procedures are not detailed as requirements. Within the plant, needs for sampling are often suggested by surface monitoring results and by bioassay, and outside by analysis of plants, soils, and material from fallout trays. 15 references

  16. Airborne asbestos fibres monitoring in tunnel excavation.

    Science.gov (United States)

    Gaggero, Laura; Sanguineti, Elisa; Yus González, Adrián; Militello, Gaia Maria; Scuderi, Alberto; Parisi, Giovanni

    2017-07-01

    Tunnelling across ophiolitic formation with Naturally Occurring Asbestos (NOA) can release fibres into the environment, exposing workers, and the population, if fibres spread outside the tunnel, leading to increased risk of developing asbestos-related disease. Therefore, a careful plan of environmental monitoring is carried out during Terzo Valico tunnel excavation. In the present study, data of 1571 samples of airborne dust, collected between 2014 and 2016 inside the tunnels, and analyzed by SEM-EDS for quantification of workers exposure, are discussed. In particular, the engineering and monitoring management of 100 m tunnelling excavation across a serpentinite lens (Cravasco adit), intercalated within calcschists, is reported. At this chrysotile occurrence, 84% of 128 analyzed samples (from the zone closer to the front rock) were above 2 ff/l. However, thanks to safety measures implemented and tunnel compartmentation in zones, the asbestos fibre concentration did not exceed the Italian standard of occupational exposure (100 ff/l) and 100% of samples collected in the outdoor square were below 1 ff/l. During excavation under normal working conditions, asbestos concentrations were below 2 ff/l in 97.4% of the 668 analyzed samples. Our results showed that air monitoring can objectively confirm the presence of asbestos minerals at a rock front in relative short time and provide information about the nature of the lithology at the front. The present dataset, the engineering measures described and the operative conclusions are liable to support the improvement of legislation on workers exposure to asbestos referred to the tunnelling sector, lacking at present. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Optical Properties of Airborne Soil Organic Particles

    Energy Technology Data Exchange (ETDEWEB)

    Veghte, Daniel P. [William; China, Swarup [William; Weis, Johannes [Chemical; Department; Kovarik, Libor [William; Gilles, Mary K. [Chemical; Laskin, Alexander [Department

    2017-09-27

    Recently, airborne soil organic particles (ASOP) were reported as a type of solid organic particles emitted after water droplets impacted wet soils. Chemical constituents of ASOP are macromolecules such as polysaccharides, tannins, and lignin (derived from degradation of plants and biological organisms). Optical properties of ASOP were inferred from the quantitative analysis of the electron energy-loss spectra acquired over individual particles in the transmission electron microscope. The optical constants of ASOP are further compared with those measured for laboratory generated particles composed of Suwanee River Fulvic Acid (SRFA) reference material, which was used as a laboratory surrogate of ASOP. The particle chemical compositions were analyzed using energy dispersive x-ray spectroscopy, electron energy-loss spectroscopy, and synchrotron-based scanning transmission x-ray microscopy with near edge x-ray absorption fine structure spectroscopy. ASOP and SRFA exhibit similar carbon composition, but SRFA has minor contributions of S and Na. When ASOP are heated to 350 °C their absorption increases as a result of their pyrolysis and partial volatilization of semi-volatile organic constituents. The retrieved refractive index (RI) at 532 nm of SRFA particles, ASOP, and heated ASOP were 1.22-62 0.07i, 1.29-0.07i, and 1.90-0.38i, respectively. Compared to RISRFA, RIASOP has a higher real part but similar imaginary part. These measurements of ASOP optical constants suggest that they have properties characteristic of atmospheric brown carbon and therefore their potential effects on the radiative forcing of climate need to be assessed in atmospheric models.

  18. An integrated compact airborne multispectral imaging system using embedded computer

    Science.gov (United States)

    Zhang, Yuedong; Wang, Li; Zhang, Xuguo

    2015-08-01

    An integrated compact airborne multispectral imaging system using embedded computer based control system was developed for small aircraft multispectral imaging application. The multispectral imaging system integrates CMOS camera, filter wheel with eight filters, two-axis stabilized platform, miniature POS (position and orientation system) and embedded computer. The embedded computer has excellent universality and expansibility, and has advantages in volume and weight for airborne platform, so it can meet the requirements of control system of the integrated airborne multispectral imaging system. The embedded computer controls the camera parameters setting, filter wheel and stabilized platform working, image and POS data acquisition, and stores the image and data. The airborne multispectral imaging system can connect peripheral device use the ports of the embedded computer, so the system operation and the stored image data management are easy. This airborne multispectral imaging system has advantages of small volume, multi-function, and good expansibility. The imaging experiment results show that this system has potential for multispectral remote sensing in applications such as resource investigation and environmental monitoring.

  19. Airborne soil particulates as vehicles for Salmonella contamination of tomatoes.

    Science.gov (United States)

    Kumar, Govindaraj Dev; Williams, Robert C; Al Qublan, Hamzeh M; Sriranganathan, Nammalwar; Boyer, Renee R; Eifert, Joseph D

    2017-02-21

    The presence of dust is ubiquitous in the produce growing environment and its deposition on edible crops could occur. The potential of wind-distributed soil particulate to serve as a vehicle for S. Newport transfer to tomato blossoms and consequently, to fruits, was explored. Blossoms were challenged with previously autoclaved soil containing S. Newport (9.39log CFU/g) by brushing and airborne transfer. One hundred percent of blossoms brushed with S. Newport-contaminated soil tested positive for presence of the pathogen one week after contact (PCompressed air was used to simulate wind currents and direct soil particulates towards blossoms. Airborne soil particulates resulted in contamination of 29% of the blossoms with S. Newport one week after contact. Biophotonic imaging of blossoms post-contact with bioluminescent S. Newport-contaminated airborne soil particulates revealed transfer of the pathogen on petal, stamen and pedicel structures. Both fruits and calyxes that developed from blossoms contaminated with airborne soil particulates were positive for presence of S. Newport in both fruit (66.6%) and calyx (77.7%). Presence of S. Newport in surface-sterilized fruit and calyx tissue tested indicated internalization of the pathogen. These results show that airborne soil particulates could serve as a vehicle for Salmonella. Hence, Salmonella contaminated dust and soil particulate dispersion could contribute to pathogen contamination of fruit, indicating an omnipresent yet relatively unexplored contamination route. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Modelling the risk of airborne infectious disease using exhaled air.

    Science.gov (United States)

    Issarow, Chacha M; Mulder, Nicola; Wood, Robin

    2015-05-07

    In this paper we develop and demonstrate a flexible mathematical model that predicts the risk of airborne infectious diseases, such as tuberculosis under steady state and non-steady state conditions by monitoring exhaled air by infectors in a confined space. In the development of this model, we used the rebreathed air accumulation rate concept to directly determine the average volume fraction of exhaled air in a given space. From a biological point of view, exhaled air by infectors contains airborne infectious particles that cause airborne infectious diseases such as tuberculosis in confined spaces. Since not all infectious particles can reach the target infection site, we took into account that the infectious particles that commence the infection are determined by respiratory deposition fraction, which is the probability of each infectious particle reaching the target infection site of the respiratory tracts and causing infection. Furthermore, we compute the quantity of carbon dioxide as a marker of exhaled air, which can be inhaled in the room with high likelihood of causing airborne infectious disease given the presence of infectors. We demonstrated mathematically and schematically the correlation between TB transmission probability and airborne infectious particle generation rate, ventilation rate, average volume fraction of exhaled air, TB prevalence and duration of exposure to infectors in a confined space. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Detection Range of Airborne Magnetometers in Magnetic Anomaly Detection

    Directory of Open Access Journals (Sweden)

    Chengjing Li

    2015-11-01

    Full Text Available Airborne magnetometers are utilized for the small-range search, precise positioning, and identification of the ferromagnetic properties of underwater targets. As an important performance parameter of sensors, the detection range of airborne magnetometers is commonly set as a fixed value in references regardless of the influences of environment noise, target magnetic properties, and platform features in a classical model to detect airborne magnetic anomalies. As a consequence, deviation in detection ability analysis is observed. In this study, a novel detection range model is proposed on the basis of classic detection range models of airborne magnetometers. In this model, probability distribution is applied, and the magnetic properties of targets and the environment noise properties of a moving submarine are considered. The detection range model is also constructed by considering the distribution of the moving submarine during detection. A cell-averaging greatest-of-constant false alarm rate test method is also used to calculate the detection range of the model at a desired false alarm rate. The detection range model is then used to establish typical submarine search probabilistic models. Results show that the model can be used to evaluate not only the effects of ambient magnetic noise but also the moving and geomagnetic features of the target and airborne detection platform. The model can also be utilized to display the actual operating range of sensor systems.

  2. Dispersion model for airborne particulates inside a building

    International Nuclear Information System (INIS)

    Perkins, W.C.; Stoddard, D.H.

    1985-01-01

    An empirical model has been developed for the spread of airborne radioactive particles after they are released inside a building. The model has been useful in performing safety analyses of actinide materials facilities at the Savannah River Plant (SRP). These facilities employ the multiple-air-zone concept; that is, ventilation air flows from rooms or areas of least radioactive material hazard, through zones of increasing hazard, to a treatment system. A composite of the data for dispersion of airborne activity during 12 actual case incidents at SRP forms the basis for this model. These incidents occurred during approximately 90 plant-years of experience at SRP with the chemical and metallurgical processing of purified neptunium and plutonium after their recovery from irradiated uranium. The model gives ratios of the airborne activity concentrations in rooms and corridors near the site of the release. The multiple-air-zone concept has been applied to many designs of nuclear facilities as a safety feature to limit the spread of airborne activity from a release. The model illustrates the limitations of this concept: it predicts an apparently anomalous behavior of airborne particulates; namely, a small migration against the flow of the ventilation air

  3. Glass characterization to assess the airborne sound isolation

    International Nuclear Information System (INIS)

    Alba Fernandez, J.; Rey Tormos, R. del; Ramis Soriano, J.; Berto Carbo, L.

    2012-01-01

    The main contribution of this paper is the formulation of an alternative to experimental determination of loss factor and, consequently, to improve the predictions of airborne sound insulation for any type of monolithic or laminated glass. In addition, a review of the standards related to measurement of mechanical parameters of glass is carried out, with particular interest in laminated glass Indeed, one of the problems that arise in the current context of building acoustics is to meet the requirements of facades airborne sound insulation of existing Building Technical Code (BTC). It is known that the blind and the hollow part of the facade should be distinguished. The weakest part regarding to airborne sound insulation is the empty one (consisting of glass, woodwork and other elements). Choosing an adequate woodwork makes the glass surface become the limiting factor. The Constructive Elements Catalog (CEC) of the BTC, the UNE-EN 12758:2011 standard, as well as some, increasingly, data vendors provide information about airborne sound insulation for monolithic glass, laminated glass and double glazing. In the case of laminated glass, these data are limited only to those with a single intermediate layer, and also nonacoustic. Can therefore be said that there is a gap of knowledge in this regard. To obtain reliable predictions of airborne sound insulation of multilayer partitions, such as laminated glass, mechanical characteristics must be known, being loss factor one of the most important. (Author) 7 refs.

  4. Human Indoor Exposure to Airborne Halogenated Flame Retardants: Influence of Airborne Particle Size.

    Science.gov (United States)

    La Guardia, Mark J; Schreder, Erika D; Uding, Nancy; Hale, Robert C

    2017-05-09

    Inhalation of halogenated flame-retardants (HFRs) released from consumer products is an important route of exposure. However, not all airborne HFRs are respirable, and thus interact with vascular membranes within the gas exchange (alveolar) region of the lung. HFRs associated with large (>4 µm), inhalable airborne particulates are trapped on the mucosal lining of the respiratory tract and then are expelled or swallowed. The latter may contribute to internal exposure via desorption from particles in the digestive tract. Exposures may also be underestimated if personal activities that re-suspend particles into the breathing zone are not taken into account. Here, samples were collected using personal air samplers, clipped to the participants' shirt collars (n = 18). We observed that the larger, inhalable air particulates carried the bulk (>92%) of HFRs. HFRs detected included those removed from commerce (i.e., polybrominated diphenyl ethers (Penta-BDEs: BDE-47, -85, -100, -99, and -153)), their replacements; e.g., 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB or EH-TBB); bis(2-ethylhexyl) 3,4,5,6-tetrabromophthalate (TBPH or BEH-TEBP) and long-produced chlorinated organophosphate-FRs (ClOPFRs): tris(2-chloroethyl)phosphate (TCEP), tris(1-chloro-2-propyl)phosphate (TCPP or TCIPP), and tris(1,3-dichloro-2-propyl)phosphate (TDCPP or TDCIPP). Our findings suggest estimates relying on a single exposure route, i.e., alveolar gas exchange, may not accurately estimate HFR internal dosage, as they ignore contributions from larger inhalable particulates that enter the digestive tract. Consideration of the fate and bioavailability of these larger particulates resulted in higher dosage estimates for HFRs with log K oa 12 (i.e., TBB and TBPH) compared to the alveolar route exposure alone. Of those HFRs examined, the most significant effect was the lower estimate by 41% for TBPH. The bulk of TBPH uptake from inhaled particles was estimated to be through the digestive tract, with

  5. DETECTION AND IDENTIFICATION OF TOXIC AIR POLLUTANTS USING AIRBORNE LWIR HYPERSPECTRAL IMAGING

    Science.gov (United States)

    Airborne longwave infrared LWIR) hyperspectral imagery was utilized to detect and identify gaseous chemical release plumes at sites in sourthern Texzas. The Airborne Hysperspectral Imager (AHI), developed by the University of Hawaii was flown over a petrochemical facility and a ...

  6. Characterization of airborne uranium from test firing of XM774 ammunition

    International Nuclear Information System (INIS)

    Glissmeyer, J.A.; Mishima, J.

    1979-11-01

    Pacific Northwest Laboratory conducted experiments at Aberdeen Proving Grounds, Maryland, to characterize the airborne depleted uranium (DU) resulting from the test firings of 105-mm, APFSDS-T XM774 ammunition. The goal was to obtain data pertinent to evaluations of human inhalation exposure to the airborne DU. Data was desired concerning the following: (1) size distribution of airborne DU; (2) quantity of airborne DU; (3) dispersion of airborne DU from the target vicinity; (4) amount of DU deposited on the ground; (5) solubility of airborne DU compounds in lung fluid; and (6) oxide forms of airborne and fallout DU. The experiments involved extensive air sampling for total airborne DU particulates and respirable DU particles both above the targets and at distances downwind. Fallout and fragments were collected around the target area. High-speed movies of the smoke generated from the impact of the penetrators were taken to estimate the cloud volumes. Results of the experiments are presented

  7. Airborne incidents : an econometric analysis of severity, December 31, 2014 : technical summary

    Science.gov (United States)

    2014-12-31

    This is a technical summary of the Airborne Incidents: An Econometric Analysis of Severity main report. : Airborne loss of separation incidents occur when an aircraft breaches the defined separation limit (vertical and/or horizontal) with anoth...

  8. Advances in the testing and evaluation of airborne radar through realtime simulation of synthetic clutter

    CSIR Research Space (South Africa)

    Strydom, JJ

    2011-11-01

    Full Text Available Clutter Simulation ? CSIR 2011 Slide 20 From: G. Morris and L. Harkness, Airborne Pulsed Doppler Radar Synthetic Clutter Simulation Recorded Data Airborne Range Doppler map ? CSIR 2011 Slide 21 Data from: Synthetic Clutter Simulation Building...

  9. CAMEX-4 CONICALLY-SCANNING TWO-LOOK AIRBORNE RADIOMETER (C-STAR) V1a

    Data.gov (United States)

    National Aeronautics and Space Administration — The CAMEX-4 Conically-Scanning Two-Look Airborne Radiometer (C-STAR) dataset was collected by the Conically-Scanning Two-look Airborne Radiometer (C-STAR), which was...

  10. Aerosol-Fluorescence Spectrum Analyzer: Real-Time Measurement of Emission Spectra of Airborne Biological Particles

    National Research Council Canada - National Science Library

    Hill, Steven

    1997-01-01

    ...) made from various biological materials (e.g., Bacillus subtilis spores, B. anthrasis spores, riboflavin, and tree leaves). The AFS may be useful in detecting and characterizing airborne bacteria and other airborne particles of biological origin.

  11. [Identification of airborne pollen and airborne particles with pollen allergen (Cry j 1, Dac g) by aeroallergen immunoblotting technique].

    Science.gov (United States)

    Takahashi, Yuichi; Nagoya, Takao; Ohta, Nobuo

    2002-08-01

    After collection of airborne particles with a seven-day recording volumetric spore trap (Burkard model) using optically clear, pressure sensitive acrylic adhesive tapes, a dry PVDF membrane was pressed down firmly onto the adhesive tape, antigen-antibody reaction was performed in full contact with the tapes and PVDF membrane. Dark purple spots from airborne pollen allergens were examined under a light microscope to evaluate the form of pollens and particles wit h the antigenicity. It is clarified that identification of the form of pollens with the antigencity is possible not only pollens with the antigenicity but a pollen has already lost its shape, and it is also clarified that some airborne particular matters have the pollen antigencity. Airborne samples were collected during the Cryptomeria japonica or grass pollen season. Samples collected during the C. japonica pollen season were treated with anti-Cry j 1 monoclonal antibody, and those during the grass pollen season with anti-Dac g rabbit IgG. Samples collected during the C. japonica and the grass pollen peak season were treated with antibodies from sera of pollinosis patients. Spots originated not only from relevant pollen grains but also from parts of airborne particular matter have the pollen antigenicity and some spots could not observed for any kind of particles.

  12. Polar gravity fields from GOCE and airborne gravity

    DEFF Research Database (Denmark)

    Forsberg, René; Olesen, Arne Vestergaard; Yidiz, Hasan

    2011-01-01

    Airborne gravity, together with high-quality surface data and ocean satellite altimetric gravity, may supplement GOCE to make consistent, accurate high resolution global gravity field models. In the polar regions, the special challenge of the GOCE polar gap make the error characteristics...... of combination models especially sensitive to the correct merging of satellite and surface data. We outline comparisons of GOCE to recent airborne gravity surveys in both the Arctic and the Antarctic. The comparison is done to new 8-month GOCE solutions, as well as to a collocation prediction from GOCE gradients...... in Antarctica. It is shown how the enhanced gravity field solutions improve the determination of ocean dynamic topography in both the Arctic and in across the Drake Passage. For the interior of Antarctica, major airborne gravity programs are currently being carried out, and there is an urgent need...

  13. Airborne signals of communication in sagebrush: a pharmacological approach.

    Science.gov (United States)

    Shiojiri, Kaori; Ishizaki, Satomi; Ozawa, Rika; Karban, Richard

    2015-01-01

    When plants receive volatiles from a damaged plant, the receivers become more resistant to herbivory. This phenomenon has been reported in many plant species and called plant-plant communication. Lab experiments have suggested that several compounds may be functioning as airborne signals. The objective of this study is to identify potential airborne signals used in communication between sagebrush (Artemisia tridentata) individuals in the field. We collected volatiles of one branch from each of 99 sagebrush individual plants. Eighteen different volatiles were detected by GC-MS analysis. Among these, 4 compounds; 1.8-cineol, β-caryophyllene, α-pinene and borneol, were investigated as signals of communication under natural conditions. The branches which received either 1,8-cineol or β-caryophyllene tended to get less damage than controls. These results suggested that 1,8-cineol and β-caryophyllene should be considered further as possible candidates for generalized airborne signals in sagebrush.

  14. The risk of airborne influenza transmission in passenger cars.

    Science.gov (United States)

    Knibbs, L D; Morawska, L; Bell, S C

    2012-03-01

    Travel in passenger cars is a ubiquitous aspect of the daily activities of many people. During the 2009 influenza A(H1N1) pandemic a case of probable transmission during car travel was reported in Australia, to which spread via the airborne route may have contributed. However, there are no data to indicate the likely risks of such events, and how they may vary and be mitigated. To address this knowledge gap, we estimated the risk of airborne influenza transmission in two cars (1989 model and 2005 model) by employing ventilation measurements and a variation of the Wells-Riley model. Results suggested that infection risk can be reduced by not recirculating air; however, estimated risk ranged from 59% to 99·9% for a 90-min trip when air was recirculated in the newer vehicle. These results have implications for interrupting in-car transmission of other illnesses spread by the airborne route.

  15. SGA-WZ: A New Strapdown Airborne Gravimeter

    DEFF Research Database (Denmark)

    Huang, Yangming; Olesen, Arne Vestergaard; Wu, Meiping

    2012-01-01

    Inertial navigation systems and gravimeters are now routinely used to map the regional gravitational quantities from an aircraft with mGal accuracy and a spatial resolution of a few kilometers. However, airborne gravimeter of this kind is limited by the inaccuracy of the inertial sensor performance......, the integrated navigation technique and the kinematic acceleration determination. As the GPS technique developed, the vehicle acceleration determination is no longer the limiting factor in airborne gravity due to the cancellation of the common mode acceleration in differential mode. A new airborne gravimeter...... taking full advantage of the inertial navigation system is described with improved mechanical design, high precision time synchronization, better thermal control and optimized sensor modeling. Apart from the general usage, the Global Positioning System (GPS) after differentiation is integrated...

  16. Parametric estimation of time varying baselines in airborne interferometric SAR

    DEFF Research Database (Denmark)

    Mohr, Johan Jacob; Madsen, Søren Nørvang

    1996-01-01

    A method for estimation of time varying spatial baselines in airborne interferometric synthetic aperture radar (SAR) is described. The range and azimuth distortions between two images acquired with a non-linear baseline are derived. A parametric model of the baseline is then, in a least square...... sense, estimated from image shifts obtained by cross correlation of numerous small patches throughout the image. The method has been applied to airborne EMISAR imagery from the 1995 campaign over the Storstrommen Glacier in North East Greenland conducted by the Danish Center for Remote Sensing. This has...... reduced the baseline uncertainties from several meters to the centimeter level in a 36 km scene. Though developed for airborne SAR the method can easily be adopted to satellite data...

  17. Data System for HS3 Airborne Field Campaign

    Science.gov (United States)

    Maskey, M.; Mceniry, M.; Berendes, T.; Bugbee, K.; Conover, H.; Ramachandran, R.

    2014-12-01

    Hurricane and Severe Storm Sentinel (HS3) is a NASA airborne field campaign aimed at better understanding the physical processes that control hurricane intensity change. HS3 will help answer questions related to the roles of environmental conditions and internal storm structures to storm intensification. Due to the nature of the questions that HS3 mission is addressing, it involves a variety of in-situ, satellite observations, airborne data, meteorological analyses, and simulation data. This variety of datasets presents numerous data management challenges for HS3. The methods used for airborne data management differ greatly from the methods used for space-borne data. In particular, metadata extraction, spatial and temporal indexing, and the large number of instruments and subsequent variables are a few of the data management challenges unique to airborne missions. A robust data system is required to successfully help HS3 scientist achieve their mission goals. Furthermore, the data system also needs to provide for data management that assists in broader use of HS3 data to enable future research activities. The Global Hydrology Resource Center (GHRC) is considering all these needs and designing a data system for HS3. Experience with past airborne field campaign puts GHRC in a good position to address HS3 needs. However, the scale of this mission along with science requirements separates HS3 from previous field campaigns. The HS3 data system will include automated services for geo-location, metadata extraction, discovery, and distribution for all HS3 data. To answer the science questions, the data system will include a visual data exploration tool that is fully integrated into the data catalog. The tool will allow visually augmenting airborne data with analyses and simulations. Satellite data will provide contextual information during such data explorations. All HS3 tools will be supported by an enterprise service architecture that will allow scaling, easy integration

  18. APEX Airborne Imaging Spectrometer Uncertainty Budget and Vicarious Validation Method

    Science.gov (United States)

    Hueni, A.; Woolliams, E.; Schlaepfer, D.; Wulf, H.

    2017-12-01

    ESA's Airborne Imaging Spectrometer APEX (Airborne Prism Experiment) was developed by a Swiss-Belgian consortium and entered its operational phase at the end of 2010 (Schaepman et al. 2015). Work on the sensor model and on propagated uncertainties from the laboratory to the in-flight case has been carried out extensively within the framework of EMRP (European Metrology Research Program) as part of the Metrology for Earth Observation and Climate (MetEOC and MetEOC2). The uncertainty propagation has been implemented in the APEX Calibration Information System (Hueni et al. 2013) and the APEX Level 1 processor (Hueni et al. 2009), thus allowing the operational computation of uncertainties for any at-sensor radiance APEX imaging cube. This fosters a better understanding and aids evaluation of the results of vicarious validation using spectral ground control points stored in the spectral information system SPECCHIO (Hueni et al. 2016). The presented work ultimately benefits the production of traceable higher-level products and enables sensitivity analyses of models, e.g. 3D canopy simulations, parameterised by APEX radiances. Hueni, A., Biesemans, J., Meuleman, K., Dell'Endice, F., Schläpfer, D., et al (2009). "Structure, Components and Interfaces of the Airborne Prism Experiment (APEX) Processing and Archiving Facility." IEEE TGRS 47(1): 29-43. Hueni, A., Damm, A., Kneubuehler, M., Schläpfer, D. and Schaepman, M. (2016). "Field and Airborne Spectroscopy Cross-Validation - Some Considerations." IEEE JSTARS 10(3): 1117 - 1135. Hueni, A., Lenhard, K., Baumgartner, A. and Schaepman, M. (2013). "The APEX (Airborne Prism Experiment - Imaging Spectrometer) Calibration Information System." IEEE TGRS 51(11): 5169-5180. Schaepman, M., Jehle, M., Hueni, A., D'Odorico, P., Damm, A., et al (2015). "Advanced radiometry measurements and Earth science applications with the Airborne Prism Experiment (APEX)." Remote Sensing of Environment 158: 207-219.

  19. The Multi-sensor Airborne Radiation Survey (MARS) Instrument

    Energy Technology Data Exchange (ETDEWEB)

    Fast, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Aalseth, Craig E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Asner, David M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bonebrake, Christopher A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Day, Anthony R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dorow, Kevin E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fuller, Erin S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glasgow, Brian D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hossbach, Todd W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hyronimus, Brian J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jensen, Jeffrey L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Kenneth I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jordan, David V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Morgen, Gerald P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Morris, Scott J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mullen, O Dennis [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Myers, Allan W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pitts, W. Karl [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rohrer, John S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Runkle, Robert C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Seifert, Allen [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shergur, Jason M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stave, Sean C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tatishvili, Gocha [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thompson, Robert C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Todd, Lindsay C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Warren, Glen A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Willett, Jesse A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wood, Lynn S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-01-11

    The Multi-sensor Airborne Radiation Survey (MARS) project has developed a new single cryostat detector array design for high purity germanium (HPGe) gama ray spectrometers that achieves the high detection efficiency required for stand-off detection and actionable characterization of radiological threats. This approach, we found, is necessary since a high efficiency HPGe detector can only be built as an array due to limitations in growing large germanium crystals. Moreover, the system is ruggedized and shock mounted for use in a variety of field applications, including airborne and maritime operations.

  20. Airborne campaigns for CryoSat prelaunch calibration and validation

    DEFF Research Database (Denmark)

    Skourup, Henriette; Hanson, Susanne; Hvidegaard, Sine Munk

    2011-01-01

    After the successful launch of CryoSat-2 in April 2010, the first direct validation campaign of the satellite is planned for spring 2011. DTU Space has been involved in ESA’s CryoSat Validation Experiment (CryoVEx) with airborne activities since 2003. To validate the prelaunch performance...... of the CryoSat radar altimeter (SIRAL), an airborne version of the SIRAL altimeter (ASIRAS) has been flown together with a laser scanner in 2006 and 2008. Of particular interest is to study the penetration depth of the radar altimeter over both land- and sea ice. This can be done by comparing the radar...