18 documents found, page 1 of 2
Corrosion behaviour in artificial saliva of medical grade SS316L sputter-coated...
Frois, António; Faia, Pedro; Santos, Luis; Santos, Ana; Louro, C.ABSTRACT: Hydrogenated amorphous carbon (a-C:H) top layer was deposited onto 316L medical grade stainless steel by reactive magnetron sputtering with two types of interlayers, based on Cr and Ti. The goal was to evaluate the effect of the adhesion-promoting layers on the overall coating/substrate system. After the immersion test in acidic artificial saliva, no surface signs of corrosion were detected. However, ...
Corrosion behaviour in artificial saliva of medical grade SS316L sputter-coated...
Frois, António; Faia, Pedro; Santos, Luis; Santos, Ana; Louro, C.ABSTRACT: Hydrogenated amorphous carbon (a-C:H) top layer was deposited onto 316L medical grade stainless steel by reactive magnetron sputtering with two types of interlayers, based on Cr and Ti. The goal was to evaluate the effect of the adhesion-promoting layers on the overall coating/substrate system. After the immersion test in acidic artificial saliva, no surface signs of corrosion were detected. However, ...
Features of the incorporation of single and double based powders within emulsio...
Ribeiro, J. B.; Mendes, R.; Tavares, B.; Louro, C.In this work, features of the thermal and detonation behaviour of compositions resulting from the mixture of single and double based powders within ammonium nitrate based emulsion explosives are shown. Those features are portrayed through results of thermodynamic-equilibrium calculations of the detonation velocity, the chemical compatibility assessment through differential thermal analysis [DTA] and thermo grav...
Protective Ag :TiO2 thin films for pressure sensors in orthopedic prosthesis: t...
Lopes C.; Fonseca P.; Matamá, Maria Teresa; Gomes, Andreia C; Louro, C.; Paiva, Sandra; Vaz, F.DC reactive magnetron sputtered Ag:TiO2 nanocomposite thin films were developed to be used as protective coatings in pressure sensor devices. The coatings, with Ag content varying from 0 to about 30 at.%, were prepared and characterized in order to study their biological response. The as-deposited samples were annealed in vacuum at 500 °C in order to evaluate the influence of their morphological and structural ...
Effects of alkaline and acid solutions on glass/epoxy composites
Amaro, A. M.; Reis, P. N. B.; Neto, M. A.; Louro, C.Composite structures can be exposed to a range of corrosive environments during their in-service life, which causes degradation in terms of material properties. The effect of alkaline and acid solutions on the GRP mechanical properties can be found in open literature, but the studies presented are not sufficient to establish a full knowledge of this subject. In this paper the flexural properties and the impact ...
Effect of atmospheric environment on paediatric respiratory emergency admission...
Silva, G.; Dias, I.S.; Louro, C.Resumo/Abstract In order to assess the effect of atmospheric environmental factors on children’s health, we carried out a regression analysis by using paediatric respiratory emergency admissions, several pollutants and meteorological conditions in Barreiro city, Portugal. Although generalized linear models have been used for modeling that kind of data, generalized additive models can be a good option, especiall...
Análise Bayesiana do Efeito da Poluição Atmosférica na Admissão Hospitalar de C...
Dias, M.I.; Silva, G.; Louro, C.Air pollution is a serious environmental problem, causing adverse e ects such as respiratory disorders, allergies and, in more serious situations, degenerative lesions in the nervous system and vital organs, especially in children and the elderly. In most polluted cities, such disturbances become worse in winter with the usual low temperatures and high humidity level. Generalized linear models and generalized a...
Thermal stability in oxidative and protective environments of a-C:H cap layer o...
Louro, C.; Moura, C. Wagner; Carvalho, N.; Stueber, M.; Cavaleiro, A.Three types of hydrogenated amorphous carbon (a-C:H) coatings were synthesized on stainless steel substrates by a Plasma Assisted CVD process, containing hydrogen contents in the range from 25 to 29 at.%. The effect of annealing up to 600 °C in two different environments on both the structure and the mechanical properties of the coatings were investigated by means of Differential Scanning Calorimetry/Thermograv...
Development of new decorative coatings based on gold nanoparticles dispersed in...
Torrell, M.; Machado, P.; Cunha, L.; Figueiredo, N. M.; Oliveira, J. C.; Louro, C.; Vaz, F.The present work is devoted to the optical properties of Au:TiO2 thin films in order to clarify the role of the Au clusters inclusions in the TiO2 dielectric matrix. Three series of films containing about 30 at.% (29.2), 20 at. % (19.8) and 10 at.% (9.3) Au were deposited by dc reactive magnetron sputtering. On thermal annealing in the range from 300 to 800 °C in protective atmosphere, significant changes on th...
Effects of O addition on the thermal behaviour of hard W-N sputtered coatings
Louro, C.; Oliveira, J. C.; Cavaleiro, A.The structural thermal behaviour of three W-O-N sputtered coatings with similar metalloid to metal ratio (~2.1) was investigated up to 900 °C after annealing in a vacuum tube furnace as well as in-situ HT-XRD under a controlled atmosphere of Ar-5%H2. The as-deposited microstructure of the coatings consisting in a nanocomposite of low-order W-O and W-N phases evaluated differently as a function of the oxygen con...