446 research outputs found
Optimisation of the green synthesis of Cu/Cu2O particles for maximum yield production and reduced oxidation for electronic applications
Taguchi method with an L8 orthogonal array and analysis of variance (ANOVA) were used to evaluate the effect of pH, amount of Cynara scolymus L.(artichoke) extract (AE), copper salt concentration (SC) and temperature (T) on the optimization of green synthesis of copper microparticles with respect to the maximization of the yield production and, for the first time, with respect to the minimization of the oxidation degree of the copper microparticles. Results indicate that pH and AE have greater influence on the Cu/Cu2O microparticles yield. While the pH, AE and T have greater influence on the oxidation degree of the Cu/Cu2O microparticles. XRD confirmed the minimization of Cu2O phase over Cu/Cu2O mixture, reducing Cu2O from 83% to 31%. Spherical particles of 324–711 nm were observed and the electrical resistivity of Cu/Cu2O (69/31 wt%) was 1.52 × 10 −3 Ω.cm.This work was supported by the North Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreements [project TSSiPRO - TECHNOLOGIES FOR SUSTAINABLE
AND SMART INNOVATIVE PRODUCTS, N◦ NORTE-01-0145-FEDER-000015]
Multiplicity and degree as bi‐Lipschitz invariants for complex sets
We study invariance of multiplicity of complex analytic germs and degree of complex affine sets under outer bi-Lipschitz
transformations (outer bi-Lipschitz homeomorphims of germs in the first case and outer bi-Lipschitz homeomorphims at infinity
in the second case). We prove that invariance of multiplicity in the local case is equivalent to invariance of degree in the global case.
We prove invariance for curves and surfaces. In the way we prove invariance of the tangent cone and relative multiplicities at infinity under outer bi-Lipschitz homeomorphims at infinity, and that the abstract topology of a homogeneous surface germ determines its multiplicity.The first named author is partially supported by IAS and by ERCEA 615655 NMST Consolidator Grant, MINECO by the project reference MTM2013-45710-C2-2-P, by the Basque Government through the
BERC 2014-2017 program, by Spanish Ministry of Economy and Competitiveness MINECO: BCAM Severo Ochoa excellence accreditation SEV-2013-0323, by
Bolsa Pesquisador Visitante Especial (PVE) - Ciencias sem Fronteiras/CNPq Project number: 401947/2013-0 and by Spanish MICINN project MTM2013-45710-C2-2-P.
The second named author was partially supported by CNPq-Brazil grant 302764/2014-7.
The third named author was partially supported by the ERCEA 615655 NMST Consolidator Grant and also by the Basque Government through the BERC 2014-2017 program and by Spanish Ministry of Economy and Competitiveness MINECO: BCAM Severo Ochoa excellence accreditation SEV-2013-0323
Resonant Orbital Dynamics in LEO Region: Space Debris in Focus
The increasing number of objects orbiting the earth justifies the great attention and interest in the observation, spacecraft protection, and collision avoidance. These studies involve different disturbances and resonances in the orbital motions of these objects distributed by the distinct altitudes. in this work, objects in resonant orbital motions are studied in low earth orbits. Using the two-line elements (TLE) of the NORAD, resonant angles and resonant periods associated with real motions are described, providing more accurate information to develop an analytical model that describes a certain resonance. the time behaviors of the semimajor axis, eccentricity, and inclination of some space debris are studied. Possible irregular motions are observed by the frequency analysis and by the presence of different resonant angles describing the orbital dynamics of these objects.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo UNIFESP, BR-12231280 Sao Jose Dos Campos, SP, BrazilAstron Observ, AMU, PL-60286 Poznan, PolandITA, BR-12228900 Sao Jose Dos Campos, SP, BrazilUniversidade Federal de São Paulo UNIFESP, BR-12231280 Sao Jose Dos Campos, SP, BrazilFAPESP: 2012/24369-0FAPESP: 2012/21023-6CNPq: 303070/2011-0Web of Scienc
IL-1 polymorphisms may predict unsuccessful dental implants?
AimThe aim of this study was to analyse the possible association between no success of dental implants and two polymorphisms, IL1A (-889) and IL1B (+3953), in a Caucasian Portuguese population, and a possible relationship with other potential risk variables associated with a peri-implant disease.Material and Methods155 unrelated Caucasian individuals, were divided into 2 groups: 100 with successful dental implant rehabilitations and 55 with unsuccessful ones. To identify the polymorphisms, in positions -889 of IL1A gene and +3953 of IL1B gene, was performed an oral mucosa scraping of the patients and the DNA obtained from epithelial cells. The data were analysed in the SPSS Statistics 17.0® and the statistic analysis included the independence test of the chi-square, the exact test of Fisher and techniques of analysis of binary logistic regression.ResultsThe estimated prevalence of polymorphisms of IL1A and IL1B gene, determined by the TGP (CGC Genetics, Portugal) results, in the Caucasian Portuguese population was of 33.5%.Success of rehabilitation with dental implants was more associated to a negative TGP result, whereas failure was found to be related to a positive result.Tobacco and alcohol consumption showed no statistically significant association with success or no success of the dental implants.ConclusionThe success of the dental implants was more associated with the presence of the allele 2 of the IL1A gene and the allele 2 of the IL1B gene.Tobacco and alcohol consumption showed no association with success or no success of the rehabilitation with dental implants
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