9 research outputs found

    Mechanical and microstructural characterization of MCrAlY coatings produced by laser cladding: The influence of the Ni, Co and Al content

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    [EN] Laser metal deposition (LMD) and laser cladding (LC) are alternative methods to thermal spraying processes to produce dense, high-quality coatings. In this work, two MCrAlY coatings (M=Ni+Co) have been prepared onto stainless steel substrate using a coaxial LC technique under two different Ni/Co and Al proportions. The mechanical properties were then evaluated with microhardness, nanoindentation, and three-point bending tests. The microstructure and composition of coatings were characterized by X-ray Diffraction (XRD) analysis and Field Emission Electron Microscopy (FESEM) coupled to an Energy Dispersive Spectroscopy (EDS) detector. The study revealed that the ¿/ß phases formed in the MCrAlY coating microstructure result in a lower elastic modulus than the austenitic stainless steel substrate, while an inverse behavior for hardness was observed due the presence of the aluminum-rich ß-phase. Under flexural loads, the failure of coatings showed plasticity and anisotropy characteristics depending on the two laser tracks orientations evaluated.The authors would like to acknowledge the financial support of the Ministry of Science and Innovation of the Government of Spain through research project MAT2011-28492-C03, and the support of the Generalitat Valenciana through ACOMP/2013/114Pereira, JC.; Zambrano, JC.; Rayón, E.; Yañez, A.; Amigó, V. (2018). Mechanical and microstructural characterization of MCrAlY coatings produced by laser cladding: The influence of the Ni, Co and Al content. Surface and Coatings Technology. 338:22-31. https://doi.org/10.1016/j.surfcoat.2018.01.073S223133

    Preparation of functionalized magnetic nanoparticles conjugated with feroxamine and their evaluation for pathogen detection

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    This work reports the preparation of a conjugate between amino-functionalized silica magnetite and the siderophore feroxamine. The morphology and properties of the conjugate and intermediate magnetic nanoparticles (MNPs) were examined by powder X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), magnetization studies, zeta potential measurements, Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray (EDX) mapping. Furthermore, this study investigated the interaction between the functionalized magnetic NPs and Yersinia enterocolitica wild type (WC-A) using Scanning Electron Microscopy (SEM) and TEM images. In addition, the interaction between MNPs and a Y. enterocolitica mutant strain lacking feroxamine receptor FoxA, was also used to study the binding specificity. The results showed that the capture and isolation of Y. enterocolitica by the MNPs took place in all cases. Moreover, the specific interaction between the MNP conjugate and bacteria did not increase after blocking the free amine groups with t-butoxycarbonyl (Boc) and carboxylic acid (COOH) functional groups. Electrostatic surface interactions instead of molecular recognition between MNP conjugate and feroxamine receptor seem to rule the attachment of bacteria to the conjugate

    Molecular imprinting science and technology: a survey of the literature for the years 2004-2011

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    Depression and quality of life in older adults: Mediation effect of steep quality

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    Background/Objective: Sleep insufficiency, which affects more than 45% of the world's population, has a great importance when considering older adults. Thus, this research tested a mediation hypothesis, through a path analysis, which explains how depression relates to the quality of life considering the effect's of sleep quality in older adults. Method: A sample of 187 community-dwelling Portuguese older adults answered questionnaires about sociodemographic status (age, gender, highest level of education completed, family status, sports activities, health, and retirement status), quality of life, sleep quality, and depression. Descriptive and path analysis statistics were performed considering the results of the normality test. Results: The sample has health characteristics and presents adequate sleep duration. Sleep quality acted as a mediator between depression and the quality of life in older adults, considering the variation of gender and health. This suggests that it is important to establish self-care practices, namely sleep quality, to intervene in the ageing process. Conclusions: It is important to consider sleep quality associated with depression for older adults and to test interventions to minimize health impacts. Also, more researches are needed about the primary prevention in steep quality relating to depression. (c) 2017 Asociacion Espanola de Psicologia Conductual. Published by Elsevier Espana, S.L.U.Foundation for Science and Technology-Portugal (CIEO-Research Centre for Spatial and Organizational Dynamics, University of Algarve, Portugal); Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) [BEX 1990/15-2]info:eu-repo/semantics/publishedVersio

    Molecular imprinting science and technology : A survey of the literature for the years 2004 - 2011

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    Herein, we present a survey of the literature covering the development of molecular imprinting science and technology over the years 2004-2011. In total, 3779 references to the original papers, reviews, edited volumes and monographs from this period are included, along with recently identified uncited materials from prior to 2004, which were omitted in the first instalment of this series covering the years 1930-2003. In the presentation of the assembled references, a section presenting reviews and monographs covering the area is followed by sections describing fundamental aspects of molecular imprinting including the development of novel polymer formats. Thereafter, literature describing efforts to apply these polymeric materials to a range of application areas is presented. Current trends and areas of rapid development are discussed. Copyright © 2014 John Wiley & Sons, Ltd
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