76 research outputs found
Testing the hypothesis of acquired aminoglycoside resistance in ralstonia spp.
info:eu-repo/semantics/publishedVersio
Antimicrobial resistance profiles after conjugative events with an escherichia coli isolate from hospital effluent
info:eu-repo/semantics/publishedVersio
Influence of the sodium/proton replacement on the structural, morphological and photocatalytic properties of titanate nanotubes
Titanate nanotubes (TNT) with different sodium contents have been synthesised
using a hydrothermal approach and a swift and highly controllable post-washing
processes. The influence of the sodium/proton replacement on the structural and
morphological characteristics of the prepared materials was analysed. Different
optical behaviour was observed depending on the Na+/H+ samples' content. A band
gap energy of 3.27\pm0.03 eV was estimated for the material with higher sodium
content while a value of 2.81\pm0.02 eV was inferred for the most protonated
material, which therefore exhibits an absorption edge in the near visible
region. The point of zero charge of the materials was determined and the
influence of the sodium content on the adsorption of both cationic and anionic
organic dyes was studied. The photocatalytic performance of the TNT samples was
evaluated in the rhodamine 6G degradation process. Best photodegradation
results were obtained when using the most protonated material as catalyst,
although this material has shown the lowest R6G adsorption capability.Comment: 22 pages, 8 figures, accepted for publication in Journal of
Photochemistry and Photobiology A: Chemistr
Synthesis of titanate nanofibers co-sensitized with ZnS and Bi2S3 nanocrystallites and their application on pollutants removal
The synthesis of nanocomposite materials combining titanate nanofibers (TNF)
with nanocrystalline ZnS and Bi2S3 semiconductors is described in this work.
The TNF were produced via hydrothermal synthesis and sensitized with the
semiconductor nanoparticles, through a single-source precursor decomposition
method. ZnS and Bi2S3 nanoparticles were successfully grown onto the TNF's
surface and Bi2S3-ZnS/TNF nanocomposite materials with different layouts were
obtained using either a layer-by-layer or a co-sensitization approach. The
samples' photocatalytic performance was first evaluated through the production
of the hydroxyl radical using terephthalic acid as probe molecule. All the
tested samples show photocatalytic ability for the production of this oxidizing
species. Afterwards, the samples were investigated for the removal of methylene
blue. The nanocomposite materials with best adsorption ability for the organic
dye were the ZnS/TNF and Bi2S3ZnS/TNF. The removal of the methylene blue was
systematically studied, and the most promising results were obtained
considering a sequential combination of an adsorption-photocatalytic
degradation process using the Bi2S3ZnS/TNF powder as a highly adsorbent and
photocatalyst material.Comment: 26 pages, 10 figure
Fungos associados à Musca Domestica capturadas através de armadilhas com isca química e busca direta
Operation and performance of the ATLAS semiconductor tracker
The semiconductor tracker is a silicon microstrip detector forming part of the inner tracking system of the ATLAS experiment at the LHC. The operation and performance of the semiconductor tracker during the first years of LHC running are described. More than 99% of the detector modules were operational during this period, with an average intrinsic hit efficiency of (99.74±0.04)%. The evolution of the noise occupancy is discussed, and measurements of the Lorentz angle, δ-ray production and energy loss presented. The alignment of the detector is found to be stable at the few-micron level over long periods of time. Radiation damage measurements, which include the evolution of detector leakage currents, are found to be consistent with predictions and are used in the verification of radiation background simulations
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