115 research outputs found

    From Data to Phenomena: A Kantian Stance

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    This paper investigates some metaphysical and epistemological assumptions behind Bogen and Woodward's data-to-phenomena inferences. I raise a series of points and suggest an alternative possible Kantian stance about data-to-phenomena inferences. I clarify the nature of the suggested Kantian stance by contrasting it with McAllister's view about phenomena as patterns in data sets

    Two-Functional Direct Current Sputtered Silver-Containing Titanium Dioxide Thin Films

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    The article reports on structure, mechanical, optical, photocatalytic and biocidal properties of Ti–Ag–O films. The Ti–Ag–O films were reactively sputter-deposited from a composed Ti/Ag target at different partial pressures of oxygen on unheated glass substrate held on floating potentialUfl. It was found that addition of ~2 at.% of Ag into TiO2film has no negative influence on UV-induced hydrophilicity of TiO2film. Thick (~1,500 nm) TiO2/Ag films containing (200) anatase phase exhibit the best hydrophilicity with water droplet contact angle (WDCA) lower than 10° after UV irradiation for 20 min. Thick (~1,500 nm) TiO2/Ag films exhibited a better UV-induced hydrophilicity compared to that of thinner (~700 nm) TiO2/Ag films. Further it was found that hydrophilic TiO2/Ag films exhibit a strong biocidal effect under both the visible light and the UV irradiation with 100% killing efficiency ofEscherichia coliATCC 10536 after UV irradiation for 20 min. Reported results show that single layer of TiO2with Ag distributed in its whole volume exhibits, after UV irradiation, simultaneously two functions: (1) excellent hydrophilicity with WDCA < 10° and (2) strong power to killE. colieven under visible light due to direct toxicity of Ag

    New Insights into the Mechanism of Visible Light Photocatalysis

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    ABSTRACT: In recent years, the area of developing visible-lightactive photocatalysts based on titanium dioxide has been enormously investigated due to its wide range of applications in energy and environment related fields. Various strategies have been designed to efficiently utilize the solar radiation and to enhance the efficiency of photocatalytic processes. Building on the fundamental strategies to improve the visible light activity of TiO2-based photocatalysts, this Perspective aims to give an insight into many contemporary developments in the field of visible-light-active photocatalysis. Various examples of advanced TiO2 composites have been discussed in relation to their visible light induced photoconversion efficiency, dynamics of electron− hole separation, and decomposition of organic and inorganic pollutants, which suggest the critical need for further development of these types of materials for energy conversion and environmental remediation purposes

    Enhanced activity of silver modified thin-film TiO2 photocatalysts

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    Novel, composite silver/titania immobilized on glass substrates were prepared, characterized and their photocatalytic activity was evaluated. The undoped original material consists of rough, high surface area nanocrystalline titanium dioxide (TiO2) thin films. To increase their efficiency, the TiO2 films were modified by silver cations deposition and subsequent UV-C irradiation. SEM pictures confirmed the existence of an open porous network of interconnected titania particles on the semiconductor surface. AFM analysis proved the presence of spherical silver particles on the catalyst surface and provided quantitative surface parameters as fractal dimension, surface roughness and mean particle diameter. Spectroreflectometry showed the presence of an increase in optical absorbance attributed to plasmon resonance absorption of the silver clusters. The photocatalytic properties of the surface modified materials were investigated through photodegradation of Methyl Orange. The silver deposition conditions were optimized for maximum photocatalytic efficiency and crucial parameters such as dipping period, UV irradiation time, and concentration of the dipping solution were determined. The optimum silver nitrate concentration of the dipping solution was found to be 10-3 M. This silver doped photocatalyst decomposes the azo-dye pollutant 3-times faster than the un-doped Degussa P25 TiO2 film. A concentration increase results in a decrease of the films photocatalytic performance. Strength and reproducibility tests proved that the photocatalytic activity of the silver doped titania was perfectly reproducible

    Bacteriome and Archaeome: The Core Family Under the Microbiomic Roof

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    The concept of “bacteriome” was recast to apply to microbiomics in the late 2000s as the major (in cell population and gene context) but residual part of individual microbiomes, once mycobiome and virome were detached. Following the genomic aspect of the microbiome of the era, the bacteriome abided to the three-domain concept, thus inaugurating the archaeome as well. Both prokaryotic biomes are characterized by diverse and massive horizontal gene transfer. The sum of antagonistic and cooperative interactions among the different participant prokaryota and their respective alterations over time, either spontaneously or due to a multitude of effectors, defines their attitude toward their surroundings, environmental, industrial, or health-associated (medicinal, veterinary, and phytopathological) contexts. Diverse in functional and spatiotemporal terms, the infinite bacteriomes are focal for process-based microbiomic studies, contrary to conventional, cell-based bacteriology, revealing novel traits as the development of multicellular, possibly chimeric prokaryota, as insinuated by multispecies biofilms. They are thus bound to attract major research effort and resources in near future. © 2020 Elsevier Inc. All rights reserved

    The design and photoreaction kinetic modeling of a gas-phase titania foam packed bed reactor

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    The design and testing as well as theoretical and experimental study involving kinetic modeling and photooxidation reactions of a gas-phase photocatalytic packed bed reactor (PBR) based on a porous titania foam is reported. The photoreactor was designed to incorporate a nanoporous titania foam photocatalyst for volatile organic compound (VOC) remediation in the gas-phase. Theoretical and experimental studies based on the photodegradation of model volatile organic compounds (VOCs), have been carried out and results show that 90% degradation can be achieved in the photoreactor which has been designed at low cost and to provide increased efficiency at elevated pollutant feed. The reactor represents an inexpensive design and can be applied to the remediation of various pollutants of biological, organic or inorganic origin. In addition, the reactor can accommodate the photocatalyst in the form of a thin film and porous foams. © 2007 Elsevier B.V. All rights reserved

    Cluster of Fusarium verticillioides bloodstream infections among immunocompetent patients in an internal medicine department after reconstruction works in Larissa, Central Greece

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    Background: Fusarium spp. can cause disseminated infections, particularly in immunocompromised patients. Fusarium verticillioides is a human pathogen, and sporadic cases of fusariosis have been reported. Aim: To report a nosocomial cluster of F.verticillioides bloodstream infections among seven immunocompetent inpatients following reconstruction works. Methods: Identification was performed using macroscopic and microscopic morphology, and molecular assays (sequencing the nuclear ribosomal internal transcribed spacer region and translation elongation factor-1α gene). Susceptibility testing was performed in accordance with the guidelines of the Clinical and Laboratory Standards Institute. Environmental surveillance specimens were taken and cultured on Sabouraud dextrose agar plates. Findings: In total, 16 blood cultures obtained from the seven patients were positive for F.verticillioides. All surveillance cultures were negative. Conclusions: In order to prevent fungaemia, it is important to implement effective infection control measures, before, during and after demolition and construction activities in healthcare settings. © 2014 The Healthcare Infection Society
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