41 documents found, page 1 of 5
High-temperature tribological behaviour and machining performance of self-lubri...
Rajput, S.S.; Upadhyay, C.; Gangopadhyay, S.; Fernandes, F.; Fernandes, FilipeTribological and machining performance of CrAlNAg coatings having different Ag content tested against AISI 1045 medium carbon steel were assessed. Wear track was evaluated by scanning electron microscopy and energy dispersive spectroscopy. 3D topography of wear track and ball counterpart was determined by non-contact type profilometer. The formation of different oxide phases on track was confirmed using Raman s...
Ti-Zr-Nb-(V) refractory alloy coatings deposited by highpower impulse magnetron...
Fraile, A.; Cavaleiro, D.; Bondarev, A.; Middleburgh, S.C.; Lee, W.E.; Fernandes, F.; Fernandes, FilipeA series of TiZrNb(V) high entropy alloy-based metallic coatings have been deposited using high-power impulse magnetron sputtering (HiPIMS), with variable V concentrations and constant ratios among the other metals. The coatings were analyzed regarding their composition, surface and cross-sectional morphologies, microstructure, roughness, mechanical properties, oxidation resistance, and thermal stability. The s...
Synthesis of (Ti, W, Mo) CN based cermets with different carbides configuration...
Rafiaei, Seyed Mahdi; Hadi, Morteza; Fernandes, F.; Fernandes, FilipeIn this study, based on different element configurations within constant atomic ratio of elements, (Ti0.93W0.07Mo0.07)C–20%Ni and (Ti0.93W0.07Mo0.07)CN0.3-20%Ni derived cermets have been synthesized. The basis for the difference in the production route was whether the carbides were formed by carbothermic reaction from the metal oxide together or separately, or in the case of Mo2C, the carbide is added to the mi...
Design and industrial implementation of a multi-functional part produced by pow...
Lopes, A. C.; Sampaio, Álvaro M.; Fernandes, F.; Vaz, P. M.; Pontes, A. J.The use of robot end-effectors programmed to perform handling tasks in industrial environments has expanded in several sectors as a consequence of the rapid digital transformation seen in recent years. With such growing demands, additive manufacturing is evolving in the robotics field with more efficient, innovative, and customer-specific solutions owing to its design flexibility. Thus, this work presents a rob...
Effect of substrate bias voltage on structural and tribological properties of W...
Ataie, S.A.; Soltanieh, M.; Naghizadeh, R.; Cavaleiro, A.; Evaristo, M.; Fernandes, F.; Ferreira, F.Protective multi-component thin films at the surface of cutting tools have been significantly developed to reduce wear and friction. The present work investigates the effect of substrate bias voltage on the structural-tribological relations of W-Ti-C-N thin films produced by HiPIMS and DCMS co-sputtering. Chemical analysis of the coatings is obtained and composite phase structure is revealed. Morphology of the ...
The role of interfaces and morphology on silver diffusion in hard coatings
Cavaleiro, D.; Munnik, F.; Krause, M.; Carbo-Argibay, E.; Ferreira, P.J.; Cavaleiro, A.; Fernandes, F.One of the main approaches to increase the tool lifetime during dry machining of “hard-to-machine” aerospace alloys is self-lubrication by the incorporation of noble metals in hard matrixes with good mechanical and diffusion barrier properties. In this paper, the diffusion of an Ag-rich layer sandwiched between two layers of either TiN or TiSiN is studied by transmission electron microscopy and in situ Rutherfo...
Effect of peak power on microstructure, mechanical and tribological properties ...
Ataie, S.A.; Soltanieh, M.; Naghizadeh, R.; Cavaleiro, A.; Fernandes, F.; Ferreira, F.This research investigates the impact of peak power (from 44 to 105 kW) on the structural and tribological properties of W-Ti-C-N(O) films. Chemical analysis of the coatings, using energy-dispersive spectroscopy and Raman spectroscopy, indicates that increasing target power results in a rise in the oxygen (from 2.6 to 12.0 at%), carbon (from 19.7 to 32.4 at%), and sp3 (from 9.8% to 24.3%) content. Morphological...
Preliminary findings from the follow-up of pregnant sickle cell disease patient...
Brito, Miguel; Ginete, Catarina; Ferreira, J.; Delgadinho, Mariana; Sebastião, Cruz; Mateus, A.; Mendes, M.; Quinto, F.; Simão, F.; Fernandes, F.Background: In Angola, the prevalence of Sickle Cell Disease (SCD) is almost 2%, and the carriers reach 21% of the population. Although its presentation tends to be very heterogeneous, chronic hemolytic anemia, frequent painful crises, and extensive organ damage are common features of these patients. Pregnancy in SCD patients is associated with an increase in severe outcomes, namely, a high risk of eclampsia an...
BODY MASS INDEX AND BLOOD PRESSURE IN FIGUEIRA DA FOZ PEDIATRIC POPULATION - A ...
Paz, G.; Vale, C.; Teles, E.; Teixeira, C.; Ribeiro, M.; Martins, I.; Viegas, A.; Pereira, T.; Rosa, M.; Fernandes, F.Introduction and Objectives: Increasing number of studies show an association between overweight and obesity with arterial hypertension in childhood. The aim of this study was to assess body mass index (BMI) and high blood pressure (HBP) and its association in children and adolescents.Methods: Observational, cross-sectional and analytical study. Data was collected from the medical records of patients between 5 ...
Provision of Preexposure Prophylaxis at the Portuguese National Health Service ...
Meireles, P.; Fernandes, F.; Rocha, Miguel; Plankey, M.; Barros, H.We aimed to study the uptake of preexposure prophylaxis (PrEP) before and after its implementation in the Portuguese National Health Service (PNHS) among men who have sex with men (MSM). We studied 6164 participants in the Lisbon Cohort of MSM who participated between March 2014 and July 2019. 198 participants (3.2%) reported having recently used PrEP. Approximately one-third started PrEP after its implementati...