The Experts below are selected from a list of 189 Experts worldwide ranked by ideXlab platform

Jose A Ayllon - One of the best experts on this subject based on the ideXlab platform.

  • new low temperature preparation method of the tio2 porous photoelectrode for dye sensitized solar cells using uv irradiation
    Journal of Photochemistry and Photobiology A-chemistry, 2005
    Co-Authors: David Gutierreztauste, I Zumeta, Elena Vigil, M A Hernandezfenollosa, Xavier Domenech, Jose A Ayllon
    Abstract:

    Abstract Thick porous TiO 2 films have been prepared at low temperature from a mixture of a commercial TiO 2 powder (Degussa P25) and an easy-to-handle water-soluble titania precursor: titanium(IV) bis (ammonium lactato)dihydroxide. Films have been obtained spreading the mixture using “doctor blade” technique. UV light treatment using a medium-pressure mercury vapor Lamp leads to decomposition of the titania precursor as a result of the photocatalytic activity of nanocrystalline TiO 2 present in the blend. The additional titanium oxide thus formed assures both, necking between particles and film adhesion to the substrate. Porous nano-structured TiO 2 films were fabricated by this low-temperature method (always lower than 80 °C) on transparent conducting oxide-covered glass and flexible plastic substrates (indium-tin-oxide on glass and on PET, and fluorine-doped tin oxide on glass). The photoelectrodes obtained by this method have been characterized by scanning electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy, photoluminiscence, monochromatic incident photon-to-current conversion efficiency (IPCE) and I – V measurements. Results obtained with dye-sensitized solar cells (DSSC) built with these films are promising.

Ayato Kawashima - One of the best experts on this subject based on the ideXlab platform.

  • Degradation of methylene blue by radio frequency plasmas in water under ultraviolet irradiation.
    Journal of hazardous materials, 2009
    Co-Authors: Tsunehiro Maehara, Kyohei Nishiyama, Shingo Onishi, Shinobu Mukasa, Hiromichi Toyota, Makoto Kuramoto, Shinfuku Nomura, Ayato Kawashima
    Abstract:

    The degradation of methylene blue by radio frequency (RF) plasmas in water under ultraviolet (UV) irradiation was studied experimentally. When the methylene blue solution was exposed to RF plasma, UV irradiation from a mercury vapor Lamp enhanced degradation significantly. A Lamp without power supply also enhanced degradation since weak UV light was emitted weakly from the Lamp due to the excitation of mercury vapor by stray RF power. Such an enhancement is explained by the fact that after hydrogen peroxide is produced via the recombination process of OH radicals around the plasma, OH radicals reproduced from hydrogen peroxide via the photolysis process degrade methylene blue.

Pere Roca I Cabarrocas - One of the best experts on this subject based on the ideXlab platform.

  • Substrate versus superstrate configuration for stable thin film silicon solar cells
    Solar Energy Materials and Solar Cells, 2013
    Co-Authors: Ka-hyun Kim, S. Kasouit, Erik V. Johnson, Pere Roca I Cabarrocas
    Abstract:

    Abstract We report on the light-induced degradation kinetics of hydrogenated polymorphous silicon (pm-Si:H) solar cells having either substrate or superstrate device configuration. Both types of devices were exposed to light-soaking for 500 h. While pm-Si:H superstrate solar cells showed strong degradation (up to 60%) under mercury vapor Lamp illumination, we have found that substrate structures are remarkably stable. The difference between the two types of devices is shown to be related to interface delamination which only occurs in superstrate devices. We further demonstrate a strong correlation between short-circuit current density decrease upon light-soaking and solar cell area loss.

Vipin K. Rastogi - One of the best experts on this subject based on the ideXlab platform.

  • Inactivation of Bacillus anthracis and Bacillus atrophaeus spores on different surfaces with ultraviolet light produced with a low-pressure mercury vapor Lamp or light emitting diodes.
    Journal of applied microbiology, 2020
    Co-Authors: Joseph P. Wood, J. Archer, M.w. Calfee, Shannon Serre, Leroy Mickelsen, A. Mikelonis, L. Oudejans, S. Hurst, Vipin K. Rastogi
    Abstract:

    Aims To obtain quantitative efficacy data of two ultraviolet light (UVC) technologies for surface inactivation of Bacillus anthracis Ames and Bacillus atrophaeus spores. Methods and results Spores were deposited onto test coupons and controls of four different materials, via liquid suspension or aerosol deposition. The test coupons were then exposed to UVC light from either a low-pressure mercury vapor Lamp or a system comprised of light emitting diodes, with a range of dosages. Positive controls were held at ambient conditions and not exposed to UVC light. Following exposure to UVC, spores were recovered from the coupons and efficacy was quantified in terms of log10 reduction (LR) in the number of viable spores compared to that from positive controls. Conclusions Decontamination efficacy varied by material and UVC dosage (efficacy up to 5·7 LR was demonstrated). There was no statistical difference in efficacy between the two species or between inoculation methods. Efficacy improved for the LED Lamp at lower relative humidity, but this effect was not observed with the mercury vapor Lamp. Significance and impact of the study This study will be useful in determining whether UVC could be used for the inactivation of B. anthracis spores on different surface types.

Maria Valnice Boldrin Zanoni - One of the best experts on this subject based on the ideXlab platform.

  • assessment of the breakdown products of solar uv induced photolytic degradation of food dye tartrazine
    Food and Chemical Toxicology, 2014
    Co-Authors: Tuane Cristina Dos Santos, Guilherme Juliao Zocolo, Daniel Alexandre Morales, Gisela De Aragão Umbuzeiro, Maria Valnice Boldrin Zanoni
    Abstract:

    Abstract The food dye tartrazine (CI 19140) was exposed to UV irradiation from an artificial source, a mercury vapor Lamp, and a natural one, sunlight. It was observed that conditions such as energy dose, irradiation time, pH and initial dye concentration affected its discoloration. There was 100% of color removal, after 30 min of irradiation, when a dye solution 1 × 10 −5  mol L −1 was submitted to an energy dose of 37.8 J cm −2 . Liquid Chromatography coupled to Diode Array Detection and Mass Spectrometry confirmed the cleavage of the chromophore group and the formation of five by-products at low concentration. Although by-products were formed, the Salmonella / microsome mutagenicity assay performed for both, the dye solution at a dose of 5.34 mg/plate and the solutions obtained after exposure to UV irradiation, did not present mutagenic activity for TA98 and TA100 with and without S9.