1,720,970 research outputs found
Titania nano-coated quartz wool for the photocatalytic mineralisation of emerging organic contaminants
No full textMany emerging contaminants pass through conventional wastewater treatment plants, contaminating surface and drinking water. The implementation of advanced oxidation processes in existing plants for emerging contaminant remediation is one of the challenges for the enhancement of water quality in the industrialised countries. This paper reports on the production of a TiO2 nano-layer on quartz wool in a relevant amount, its characterisation by X-ray diffraction and scanning electron microscopy, and its use as a photocatalyst under ultraviolet radiation for the simultaneous mineralisation of five emerging organic contaminants (benzophenone-3, benzophenone-4, carbamazepine, diclofenac, and triton X-100) dissolved in deionised water and tap water. This treatment was compared with direct ultraviolet photolysis and with photocatalytic degradation on commercial TiO2 micropearls. The disappearance of every pollutant was measured by high performance liquid chromatography and mineralisation was assessed by the determination of total organic carbon. After 4 hours of treatment with the TiO2 nano-coated quartz wool, the mineralisation exceeds 90% in deionised water and is about 70% in tap water. This catalyst was reused for seven cycles without significant efficiency loss. © IWA Publishing 2018
N- and P-doped Polydithieno[3,4-B:3′,4′-D] thiophene: A narrow band gap polymer for redox supercapacitors
No full textWe studied polydithieno[3,4-b:3′,4′-d]thiophene (pDTT), an electronically conducting polymer with a narrow band gap, and our data clearly demonstrated that the charge injection of both signs is possible in electrolytic media with tetraalkylammonium salts. This is an important feature for the development of polymer-based redox supercapacitors with high charge storage capacity and high operating potential. Electrochemical characterization data of p- and n-doped pDTT films electrosynthesized in different conditions and on several electrode materials are reported. Successful results were achieved on carbon paper electrodes where the same p- and n-doping levels were reached. © 1995
Archaeometric investigations of sgraffito ceramic tiles (XV-XVI centuries) recovered from excavations in Udine (North-East Italy)
No full textOxidation Resistance of Pressureless-Sintered SiC-AlN-Re2O 3 Composites Obtained without Powder Bed
No full textOxidation resistance of SiC-AlN-Re2O3 composites (SiC 50%wt-AlN 50%wt) pressureless-sintered with an innovative and cost-effective method is reported, Yttria, Lutetia, Ytterbia and Erbia were tested as sintering-aids in this pressureless-sintered process which does not require the use of the powder bed to protect samples during the heat treatments, Sintered density was always >95%T.D. and microstructure was mainly composed by 2H SiC-AlN solid solution with well-dispersed grain boundary phases. The sintered samples, after oxidation in the temperature range 1200-1200°C over a period of time of 200h, showed a parabolic oxidation behaviour with diffusion of oxygen through the silica-based surface and interfacial reactions silica-alumina and silica-rare-earth oxides as rate-determining steps
Lifetime estimation of a zirconia-alumina composite for biomedical applications
No full textObjectives In this work long term stability of a zirconia toughened alumina (ZTA) composite was investigated. Methods Accelerated aging tests under hydrothermal environment, in autoclave and hot water, at different temperature, was conducted on material sample. Tetragonal to monoclinic transformation was evaluated by XRD analysis and the monoclinic content was plot as a function of the exposure time. The kinetic of transformation was studied by means Mehl-Avrami-Johnson (MAJ) nucleation and growth model. Results An activation energy for tetragonal to monoclinic transformation of 99 kJ/mol was found by the Arrhenius plot of reaction rate, value in agreement with other bibliography works regarding Y-TZP and alumina-zirconia composites. The in vivo hydrothermal stability simulation, estimated by the obtained activation energy, predicts in 65 years the time necessary to reach 25 vol% of monoclinic phase. Significance These results support the material suitability in biomedical field, especially in dentistry applications as implantology. © 2013 Academy of Dental Materials
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Assessing Silicon Carbide Ceramics and Composites for Energy-Related Applications
Full text linkSilicon carbide ceramics are really appreciated in energy applications, especially when extreme environments are involved. Their reliability and thermomechanical performances beyond 1000°C are higher than that of superalloys, therefore they may significantly contribute to the reduction of Critical Raw Materials use, which is a crucial point for sustainability issues. The examples discussed in the present paper are taken from European projects, in the field of nuclear energy (IV gen fission nuclear reactors) and renewable energy production (Concentrated Solar Power) and demonstrate a common approach based on optimizing and assessing the ceramic materials, considering current international standards, but also prenormative research and accelerated ageing tests in expected working environments. In this way, together with a simultaneous process implementation for the production of components in the size and geometry required for the applications, high target TRL (5-7) can be demonstrated, creating the competencies, the methods and the results needed for subsequent industrialisation. İ 2018 IEEE
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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