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Prof. Ana Paula Betencourt Martins Amaro
University of Coimbra, CEMMPRE, Department of Mechanical Engineering

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0 Biomechanics
0 composite material
0 numercial simulation
0 Nanaocomposites
0 Adhesive Joint

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Review
Published: 23 June 2021 in Polymers
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The objective of current work is to analyse the influence of different welding techniques and welding parameters on the morphology and mechanical strength of friction stir welds (FSW) in polymers, based on data collected in the literature. In the current work, only articles that provide data on the joint efficiency, or sufficient information to estimate it are considered. The process using conventional tool is presented and compared with new procedures developed for FSW of polymers, such as those using tools with heated stationary shoulder, preheating of the polymer or double-side passage of the tool. The influence of tool rotational speed (w), welding speed (v), tilt angle and geometry of the pin are discussed. This work focuses on the polymers most studied in the literature, polyethylene (PE) and polypropylene (PP). The use of external heating and tools with stationary shoulder proved to be of great importance in improving the surface finish, reducing defects, and increasing the mechanical strength of the welds. The increase in the w/v ratio increased the joint efficiency, especially when using conventional tools on PE. A trend was obtained for conventional FSW, but it was difficult to establish mathematical relationships, because of the variability of welding conditions.

ACS Style

Miguel Pereira; Ana Amaro; Paulo Reis; Altino Loureiro. Effect of Friction Stir Welding Techniques and Parameters on Polymers Joint Efficiency—A Critical Review. Polymers 2021, 13, 2056 .

AMA Style

Miguel Pereira, Ana Amaro, Paulo Reis, Altino Loureiro. Effect of Friction Stir Welding Techniques and Parameters on Polymers Joint Efficiency—A Critical Review. Polymers. 2021; 13 (13):2056.

Chicago/Turabian Style

Miguel Pereira; Ana Amaro; Paulo Reis; Altino Loureiro. 2021. "Effect of Friction Stir Welding Techniques and Parameters on Polymers Joint Efficiency—A Critical Review." Polymers 13, no. 13: 2056.

Journal article
Published: 06 May 2021 in Applied Sciences
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The main purpose of this work was to analyze the stress distribution in premolars restored with indirect IPS Empress® CAD onlays or inlays. The three-dimensional geometry of a human first premolar was created using modeling software. The tooth fixation system was simulated through box geometry, comprising a cortical bone layer with 2 mm of thickness over a layer of trabecular bone with 15 mm of thickness. The tooth had the following approximated crown dimensions: 10.35 mm buccolingual length; 7.1 mm mesiodistal width; and 7.0 mm cervico-occlusal height. The mesio-occluso-distal (MOD) cavity preparations followed the suggestions available in the literature. The cement geometry was modified to include cohesive zone models (CZM) to perform the adhesive joint’s strength prediction. The loading body was created assuming contact between the food bolus and the tooth surface. Numerical solutions were obtained by performing static analysis and damage analysis using the finite element method. Von Mises stress values generated in the ceramic inlay restoration ranged from 1.39–181.47 MPa, which were on average 4.4% higher than those of the onlay ceramic restoration. The fracture strength of the onlay restoration was about 18% higher than that of the inlay restoration. The onlay design seems to contribute to higher homogenization of the adhesive resin cement strain and higher tooth structure protection.

ACS Style

Maria Neto; Luis Roseiro; Ana Messias; Rui Falacho; Paulo Palma; Ana Amaro. Influence of Cavity Geometry on the Fracture Strength of Dental Restorations: Finite Element Study. Applied Sciences 2021, 11, 4218 .

AMA Style

Maria Neto, Luis Roseiro, Ana Messias, Rui Falacho, Paulo Palma, Ana Amaro. Influence of Cavity Geometry on the Fracture Strength of Dental Restorations: Finite Element Study. Applied Sciences. 2021; 11 (9):4218.

Chicago/Turabian Style

Maria Neto; Luis Roseiro; Ana Messias; Rui Falacho; Paulo Palma; Ana Amaro. 2021. "Influence of Cavity Geometry on the Fracture Strength of Dental Restorations: Finite Element Study." Applied Sciences 11, no. 9: 4218.

Journal article
Published: 22 January 2021 in Applied Sciences
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Basketball is a team sport in which the players undergo rapid reactions, and running efforts are usually carried out in all directions. The main goal of the present study was to evaluate the muscle activity response in different basketball movements, considering two types of athletes with different levels of experience. Using a group of nine volunteers, female athletes from a senior basketball team, a data acquisition protocol was defined to identify the changes that occurred throughout the sports season. In this study, to assess the gastrocnemius muscle activity, intensity peak (%MC) and time to peak (TP) were evaluated for five typical basketball skills and movements involving running and jumping with and without the ball. Seven repetitions were executed for each movement, performed at two different time-points of the sports season: at the beginning of the teams’ competition, in November (T1), and at the season peak, in March (T2). TP presents greater values for T2 of the season when compared with T1. The results show that the level of experience of the athletes has a significant effect on the results of TP and %MC, particularly when comparing the two seasons.

ACS Style

Catarina M. Amaro; Maria António Castro; Luis Roseiro; Rui Mendes; Ana M. Amaro. Gastrocnemius Activation throughout the Competitive Season in Athletes of Different Experience Levels. Applied Sciences 2021, 11, 984 .

AMA Style

Catarina M. Amaro, Maria António Castro, Luis Roseiro, Rui Mendes, Ana M. Amaro. Gastrocnemius Activation throughout the Competitive Season in Athletes of Different Experience Levels. Applied Sciences. 2021; 11 (3):984.

Chicago/Turabian Style

Catarina M. Amaro; Maria António Castro; Luis Roseiro; Rui Mendes; Ana M. Amaro. 2021. "Gastrocnemius Activation throughout the Competitive Season in Athletes of Different Experience Levels." Applied Sciences 11, no. 3: 984.

Journal article
Published: 12 January 2021 in Applied Sciences
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The main purpose of this work was to construct a clinically valid numerical model of a mandibular Kennedy class I patient rehabilitated with a conventional removable partial denture and another two with implant-assisted removable partial dentures at two different implant locations. The selected patient was classified as ASA I and its mandible geometry reconstruction was performed by the conversion of the Cone-Beam computed Tomography (CBCT) scan raw medical data into a 3D model and subsequent conversion to a CAD file by reverse engineering methods. The soft tissue and removable denture geometries were also included in the CAD model as well as implants, ball attachments and matrix. Moreover, periodontal ligament was modelled by offsetting the mesh of the root surface of each tooth. The finite element results showed that the installation of a dental implant in each of the bilateral edentulous regions helps providing support and retention to the extension bases of the Removable Partial Denture (RPD) and significantly reduces the vertical and anterior-posterior displacements, regardless of its position.

ACS Style

Ana Messias; Maria A. Neto; Ana M. Amaro; Vítor M. Lopes; Pedro Nicolau. Mechanical Evaluation of Implant-Assisted Removable Partial Dentures in Kennedy Class I Patients: Finite Element Design Considerations. Applied Sciences 2021, 11, 659 .

AMA Style

Ana Messias, Maria A. Neto, Ana M. Amaro, Vítor M. Lopes, Pedro Nicolau. Mechanical Evaluation of Implant-Assisted Removable Partial Dentures in Kennedy Class I Patients: Finite Element Design Considerations. Applied Sciences. 2021; 11 (2):659.

Chicago/Turabian Style

Ana Messias; Maria A. Neto; Ana M. Amaro; Vítor M. Lopes; Pedro Nicolau. 2021. "Mechanical Evaluation of Implant-Assisted Removable Partial Dentures in Kennedy Class I Patients: Finite Element Design Considerations." Applied Sciences 11, no. 2: 659.

Journal article
Published: 04 December 2020 in Applied Sciences
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Sports activity is extremely important in the health context, with a clear motivation for its practice. One of the sports that involve more athletes is basketball, where the human body undergoes rapid reactions, emphasizing the contact of the foot with the ground. The main goal of the present study is to evaluate the distribution of plantar pressure in five different basketball movements. Supported by a group of nine volunteer female athletes from a senior basketball team, a data acquisition protocol was defined to identify the changes that occur throughout the sports season. In this study, the maximum values of plantar pressure were evaluated for both feet. The five movements that were defined and studied are all movements that might be performed during the basketball practice period. To guarantee the necessary conditions of data reliability and repeatability, at least seven repetitions were performed for each movement, which occurred at two different moments of the sports season: at the beginning of the competition in November, and at season peak, four months later, in March. Overall, the results obtained did not present statistically significant changes between the two seasons in this study. However, a slight decrease was observed throughout the sporting season for all movements, except for the rebound, where there was a contrary evaluation. Additionally, athletes with a higher level of experience show higher values of plantar pressure than less experienced athletes.

ACS Style

Catarina M. Amaro; Maria A. Castro; Luis Roseiro; Maria A. Neto; Ana M. Amaro. Plantar Pressure Evaluation during the Season in Five Basketball Movements. Applied Sciences 2020, 10, 8691 .

AMA Style

Catarina M. Amaro, Maria A. Castro, Luis Roseiro, Maria A. Neto, Ana M. Amaro. Plantar Pressure Evaluation during the Season in Five Basketball Movements. Applied Sciences. 2020; 10 (23):8691.

Chicago/Turabian Style

Catarina M. Amaro; Maria A. Castro; Luis Roseiro; Maria A. Neto; Ana M. Amaro. 2020. "Plantar Pressure Evaluation during the Season in Five Basketball Movements." Applied Sciences 10, no. 23: 8691.

Journal article
Published: 03 September 2020 in Applied Sciences
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The literature reports benefits when the cork powder obtained from industrial by-products is used as the filler of composite laminates. For example, while the fatigue life is insensitive to the presence of cork in the resin, significant improvements are achieved in terms of to low-velocity impact strength. However, in terms of ballistic domain, the literature does not yet report any study about the effect of incorporating powdered cork into resins. Therefore, this study intended to analyse the ballistic behaviour and damage tolerance of Kevlar/epoxy reinforced composites with matrix filled by cork powder. For this purpose, high-velocity impacts were studied on plates of Kevlar bi-directional woven laminates with surfaces of 100 × 100 mm2. It was possible to conclude that the minimum velocity of perforation is 1.6% higher when the cork powder is added to the resin, but considering the dispersion, this small difference can be neglected. In terms of damage areas, they are slightly lower when cork dust is added, especially for velocities below the minimum perforation velocity. Finally, the residual bending strength shows that these composites are less sensitive to impact velocity than the samples with neat resin. In addition to these benefits, cork powder reduces the amount of resin in the composite, making it more environmentally friendly.

ACS Style

Ana Martins Amaro; Paulo Nobre Balbis Reis; Ines Ivañez; Sonia Sánchez-Saez; Shirley Kalamis Garcia-Castillo; Enrique Barbero. The High-Velocity Impact Behaviour of Kevlar Composite Laminates Filled with Cork Powder. Applied Sciences 2020, 10, 6108 .

AMA Style

Ana Martins Amaro, Paulo Nobre Balbis Reis, Ines Ivañez, Sonia Sánchez-Saez, Shirley Kalamis Garcia-Castillo, Enrique Barbero. The High-Velocity Impact Behaviour of Kevlar Composite Laminates Filled with Cork Powder. Applied Sciences. 2020; 10 (17):6108.

Chicago/Turabian Style

Ana Martins Amaro; Paulo Nobre Balbis Reis; Ines Ivañez; Sonia Sánchez-Saez; Shirley Kalamis Garcia-Castillo; Enrique Barbero. 2020. "The High-Velocity Impact Behaviour of Kevlar Composite Laminates Filled with Cork Powder." Applied Sciences 10, no. 17: 6108.

Journal article
Published: 02 September 2020 in Science & Sports
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The main goal of this study was to investigate the effect of two acrobatic competition floors upon plantar pressures at the gymnasts’ feet during landings from two different falling heights. Six competition gymnasts were evaluated, three “bases” and three “tops”, with a mean age of 16 years for the bases and 12 years for the tops. Two different commercial landing surfaces (practicable) and two cushion mattresses were used, the jumps were made from two different heights: 0.45 m and 1.15 m. The data acquisition system is based on flexible reference insoles, namely the Pedar Mobile® system (Novel, Germany). The results showed that the type of landing surface as well as the height of the jump have a considerable influence on the values of plantar pressure. Moreover, the presence of the mattresses allowed to reduce significantly the plantar pressure, so the mattresses can be used during the training to avoid the occurrence of injuries. Nevertheless, is clear that the use of additional mattresses over competition floors can increase the mean asymmetry value in about 3.5%, which can be related with changes on athlete performance. L’objectif principal de cette étude était d’étudier l’effet de deux planchers de compétition acrobatique sur les pressions plantaires aux pieds des gymnastes lors des atterrissages à partir de deux hauteurs de chute différentes. Six gymnastes de compétition ont été évaluées, trois « bases » et trois « sommets », avec un âge moyen de 16 ans pour les bases et de 12 ans pour les sommets. Deux surfaces d’atterrissage commerciales différentes (praticables) et deux matelas à coussin ont été utilisés, les sauts ont été effectués à partir de deux hauteurs différentes : 0,45 m et 1,15 m. Le système d’acquisition de données est basé sur des semelles de référence flexibles, à savoir le système Pedar Mobile® (Novel, Allemagne). Les résultats ont montré que le type de surface d’atterrissage ainsi que la hauteur du saut ont une influence considérable sur les valeurs de la pression plantaire. De plus, la présence des matelas a permis de réduire considérablement la pression plantaire, de sorte que les matelas peuvent être utilisés pendant l’entraînement pour éviter la survenue de blessures. Néanmoins, il est clair que l’utilisation de matelas supplémentaires sur les sols de compétition peut augmenter la valeur d’asymétrie moyenne d’environ 3,5 %, ce qui peut être lié à des changements dans les performances de l’athlète.

ACS Style

M.F. Paulino; L.M. Roseiro; J.P. Dias; M.A. Neto; A.M. Amaro. Differences among plantar pressure of acrobatic gymnasts when they jump over two competition floors. Does the presence of mattresses affect the gymnasts’ performance? Science & Sports 2020, 36, 232.e1 -232.e9.

AMA Style

M.F. Paulino, L.M. Roseiro, J.P. Dias, M.A. Neto, A.M. Amaro. Differences among plantar pressure of acrobatic gymnasts when they jump over two competition floors. Does the presence of mattresses affect the gymnasts’ performance? Science & Sports. 2020; 36 (3):232.e1-232.e9.

Chicago/Turabian Style

M.F. Paulino; L.M. Roseiro; J.P. Dias; M.A. Neto; A.M. Amaro. 2020. "Differences among plantar pressure of acrobatic gymnasts when they jump over two competition floors. Does the presence of mattresses affect the gymnasts’ performance?" Science & Sports 36, no. 3: 232.e1-232.e9.

Journal article
Published: 09 May 2020 in Frattura ed Integrità Strutturale
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ACS Style

Paulo Nb Reis; Ana Amaro; Altino Loureiro. Comparison of mechanical performance between friction-stir spot welded and adhesive bonded joints. Frattura ed Integrità Strutturale 2020, 14, 124 -133.

AMA Style

Paulo Nb Reis, Ana Amaro, Altino Loureiro. Comparison of mechanical performance between friction-stir spot welded and adhesive bonded joints. Frattura ed Integrità Strutturale. 2020; 14 (53):124-133.

Chicago/Turabian Style

Paulo Nb Reis; Ana Amaro; Altino Loureiro. 2020. "Comparison of mechanical performance between friction-stir spot welded and adhesive bonded joints." Frattura ed Integrità Strutturale 14, no. 53: 124-133.

Review
Published: 10 April 2020 in Applied Sciences
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Structural sandwich composites have been widely used in many engineering applications, and this trend continues due to their superior mechanical properties, thermal insulation and acoustic damping. However, to further improve their mechanical properties, literature reports significant benefits obtained with nano-reinforcements. In this context, nanoclays are the most popular nano-reinforcements for polymeric nanocomposites, due to their relatively high ion exchange capacity, high aspect ratio and economic advantages. In order to stablish a systematic understanding for design criteria, this work intends to summarize all studies present in the open literature about this topic. It was possible to conclude that using nanoclays improves the mechanical properties of structural sandwich composites, especially in terms of impact strength. Nevertheless, the benefits obtained regarding fatigue performance are not adequately reported in the literature, revealing the need to develop these studies.

ACS Style

João Parente; Paulo N. B. Reis; M. Neto; A. M. Amaro. Mechanical Properties of Sandwich Composites Reinforced by Nanoclays: An Overview. Applied Sciences 2020, 10, 2637 .

AMA Style

João Parente, Paulo N. B. Reis, M. Neto, A. M. Amaro. Mechanical Properties of Sandwich Composites Reinforced by Nanoclays: An Overview. Applied Sciences. 2020; 10 (7):2637.

Chicago/Turabian Style

João Parente; Paulo N. B. Reis; M. Neto; A. M. Amaro. 2020. "Mechanical Properties of Sandwich Composites Reinforced by Nanoclays: An Overview." Applied Sciences 10, no. 7: 2637.

Articles
Published: 11 March 2020 in The Journal of Adhesion
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This research compares the mechanical behaviour of adhesive bonded (AB), friction stir spot welded (FSSW) and hybrid joints (H). The H joints were performed using both AB and FSSW. The influence of tool geometry, tool rotational speed and tool penetration depth on the joint strength were examined. The analysis of the mechanical performance of the joints was done using metallographic, hardness and tensile testing. In order to determine the local strains an optical extensometer with digital image correlation was used. Adhesive bonded joints displayed higher strength than welded or weld-bonded joints. Penetration of the tool pin into the lower plate increases the strength of the welded joint, although it has an unfavourable influence on defect formation. The weld-bonded (hybrid) joints have lower strength than adhesive-bonded joints or welded joints, as the uncured adhesive makes welding difficult, and the heat generated in the welding harms the adhesive.

ACS Style

A. M. Amaro; P. N. B. Reis; A. Loureiro. Effect of friction-stir weld parameters on hybrid bonded joints. The Journal of Adhesion 2020, 97, 1136 -1152.

AMA Style

A. M. Amaro, P. N. B. Reis, A. Loureiro. Effect of friction-stir weld parameters on hybrid bonded joints. The Journal of Adhesion. 2020; 97 (12):1136-1152.

Chicago/Turabian Style

A. M. Amaro; P. N. B. Reis; A. Loureiro. 2020. "Effect of friction-stir weld parameters on hybrid bonded joints." The Journal of Adhesion 97, no. 12: 1136-1152.

Journal article
Published: 15 February 2020 in Thin-Walled Structures
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There are no studies about stress relaxation of composite laminates after long exposure to low value electric currents. This phenomenon is very important because significant effects are expected in those materials when used in long-term applications. Therefore, the present study aims to analyse and quantify the effect of exposure to DC electric currents flowing through-thickness of the sample on the stress relaxation behaviour of carbon/epoxy laminates. For this purpose, flexural and stress relaxation tests were performed on the bending mode. It was possible to conclude that the residual flexural strength is significantly affected by the exposure time and magnitude of the electric currents. Comparatively to control samples, for example, 4 h of exposure to an electric current of 3 A promote a decrease in bending stress around 5 times higher than that observed for 1 A. From the stress relaxation tests, a decreasing of the stress over the time was observed and this tendency increases with the exposure time and the electric current magnitude. In this case, the decrease observed after 4 h of exposure is 28.6% and 30.8% higher than those observed for 1 h of exposure for currents of 1 A and 3, respectively. The Kohlrausch-Williams-Watts (KWW) model fits the experimental data with good accuracy, and it shows to be a good methodology to predict the stress relaxation against the time.

ACS Style

A.M. Amaro; P.N.B. Reis; M.A. Neto; M. Santos; J.B. Santos. Effect of the electric current on the stress relaxation behaviour of CFRP composites. Thin-Walled Structures 2020, 149, 106659 .

AMA Style

A.M. Amaro, P.N.B. Reis, M.A. Neto, M. Santos, J.B. Santos. Effect of the electric current on the stress relaxation behaviour of CFRP composites. Thin-Walled Structures. 2020; 149 ():106659.

Chicago/Turabian Style

A.M. Amaro; P.N.B. Reis; M.A. Neto; M. Santos; J.B. Santos. 2020. "Effect of the electric current on the stress relaxation behaviour of CFRP composites." Thin-Walled Structures 149, no. : 106659.

Journal article
Published: 01 February 2020 in Composite Structures
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The main goal of this work is to study the effect of solid particle erosion on the impact fatigue life. For this purpose, impingement angles of 10°, 45° and 90°, stand-off distances of 75 mm, 100 mm and 125 mm and particles size of 20 mesh, 24 mesh and 54 mesh were considered. After exposure to corundum particles flow, during 20 seg and constant pressure of 2 bar, the glass/epoxy laminates were evaluated in terms of weight loss and depth of eroded area. Finally, all samples were submitted to multi-impacts until full perforation. From the experimental tests, it can be concluded that weight loss and depth of eroded area increase with the increasing of impingement angle, reaching maximum values for 90°. In terms of distance between nozzle and target, higher values promote larger and shallower damaged areas, while smaller particles are responsible by lower weight loss and depth. Finally, the fatigue life is very sensitive to the erodent size, but the opposite tendency occurs for impingement angle and stand-off distance, alternating according to their values.

ACS Style

A.M. Amaro; A.J.R. Loureiro; M.A. Neto; P.N.B. Reis. Residual impact strength of glass/epoxy composite laminates after solid particle erosion. Composite Structures 2020, 238, 112026 .

AMA Style

A.M. Amaro, A.J.R. Loureiro, M.A. Neto, P.N.B. Reis. Residual impact strength of glass/epoxy composite laminates after solid particle erosion. Composite Structures. 2020; 238 ():112026.

Chicago/Turabian Style

A.M. Amaro; A.J.R. Loureiro; M.A. Neto; P.N.B. Reis. 2020. "Residual impact strength of glass/epoxy composite laminates after solid particle erosion." Composite Structures 238, no. : 112026.

Journal article
Published: 21 January 2020 in Applied Sciences
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This article presents an experimental study on the surface properties of epoxy resin nanocomposites (EPNCs) manufactured with a thermosetting epoxy resin (EP)–bisphenol A diglycidyl ether (BADGE)–2-[[4-[2-[4-(Oxiran-2-ylmethoxy)phenyl]propan-2-yl]phenoxy]methyl]oxirane) and filled with alumina nanoparticles (NPs). The NPs consist of pretreated (with a silane agent) alpha alumina with irregular shapes and a 100 nm maximum size. Three weight fractions of NPs were studied: 1, 3, and 5 wt. (%). Two different epoxy (EP) resins were manufactured, one cured and postcured with bis (4-aminophenyl) methane (DDM); and another one cured with 3-dodec-2-enyloxolane-2,5-dione (DDSA) + 8-methyl-3a,4,7,7a-tetrahydro-4,7-methano-2-benzofuran-1,3-dione (MNA). The wettability and the surface roughness of the obtained EPNCs were studied through the measurement of contact angles and topographic images obtained with atomic force microscopy (AFM), respectively. Significant influence of both the loading of NPs and used curing agents was observed. EPNCs cured with DDM were shown to be hydrophobic for 0, 1, and 3 wt. (%) and hydrophilic for 5 wt. (%). Maximum surface roughness was observed for 5 wt. (%). EPNCs cured with DDSA+MNA were shown to be hydrophilic for 0 and 1 wt. (%) and hydrophobic for 3 and 5 wt. (%). The surface roughness decreased as the weight fraction of NPs increased until 3 wt. (%), and then increased for 5 wt. (%).

ACS Style

Deesy Pinto; Ana M. Amaro; Luís Bernardo. Experimental Study on the Surface Properties of Nanoalumina-Filled Epoxy Resin Nanocomposites. Applied Sciences 2020, 10, 733 .

AMA Style

Deesy Pinto, Ana M. Amaro, Luís Bernardo. Experimental Study on the Surface Properties of Nanoalumina-Filled Epoxy Resin Nanocomposites. Applied Sciences. 2020; 10 (3):733.

Chicago/Turabian Style

Deesy Pinto; Ana M. Amaro; Luís Bernardo. 2020. "Experimental Study on the Surface Properties of Nanoalumina-Filled Epoxy Resin Nanocomposites." Applied Sciences 10, no. 3: 733.

Journal article
Published: 20 December 2019 in Polymers
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Polyamide creates high-performance composite materials, which are replacing the traditional epoxy composites in several applications. In this context, exposure to hostile environments is expected. On the other hand, due to the viscoelastic nature of the matrix, these composite materials are prone to stress relaxation. Therefore, the stress relaxation behaviour of glass/polyamide 6 composites was studied considering different fibre directions, as well as exposure to NaOH and HCl solutions. Stress relaxation tests on the bending mode were carried out, and the stress recorded during the loading time (7200 s). All tests were characterized by a stress decrease over time, but laminates with higher fibre angles were more prone to stress relaxation. However, exposure to hostile solutions promoted more significant decreases, where the highest stress relaxation was achieved for alkaline environments with values that were three times higher for laminates with fibres at 0° and around one and half times higher for 45° fibre alignments when compared with the control samples. Finally, the Kohlrausch–Williams–Watts (KWW) model showed that it can be used to predict stress relaxation time, due to the accuracy that was obtained between the experimental and theoretical results.

ACS Style

Paulo Nobre Balbis Dos Reis; Ana Martins Amaro; Maria Augusta Neto. Effect of Fibre Orientation and Hostile Solutions on Stress Relaxation of Glass/Polyamide Composites. Polymers 2019, 12, 20 .

AMA Style

Paulo Nobre Balbis Dos Reis, Ana Martins Amaro, Maria Augusta Neto. Effect of Fibre Orientation and Hostile Solutions on Stress Relaxation of Glass/Polyamide Composites. Polymers. 2019; 12 (1):20.

Chicago/Turabian Style

Paulo Nobre Balbis Dos Reis; Ana Martins Amaro; Maria Augusta Neto. 2019. "Effect of Fibre Orientation and Hostile Solutions on Stress Relaxation of Glass/Polyamide Composites." Polymers 12, no. 1: 20.

Journal article
Published: 18 December 2019 in Revista Portuguesa de Estomatologia, Medicina Dentária e Cirurgia Maxilofacial
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Objetivos: Etileno Vinil Acetato (EVA) é o material mais utilizado no fabrico de protetores bucais individualizados, mas apresenta algumas limitações ...

ACS Style

Maria Moreira; Paulo Reis; Ana Amaro; Ana Messias; João Carlos Ramos. #152 Teste de Impacto de novos materiais para protetores bucais. Revista Portuguesa de Estomatologia, Medicina Dentária e Cirurgia Maxilofacial 2019, 60, 61 .

AMA Style

Maria Moreira, Paulo Reis, Ana Amaro, Ana Messias, João Carlos Ramos. #152 Teste de Impacto de novos materiais para protetores bucais. Revista Portuguesa de Estomatologia, Medicina Dentária e Cirurgia Maxilofacial. 2019; 60 (1):61.

Chicago/Turabian Style

Maria Moreira; Paulo Reis; Ana Amaro; Ana Messias; João Carlos Ramos. 2019. "#152 Teste de Impacto de novos materiais para protetores bucais." Revista Portuguesa de Estomatologia, Medicina Dentária e Cirurgia Maxilofacial 60, no. 1: 61.

Journal article
Published: 18 December 2019 in Applied Sciences
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(1) Objective: External fixation systems are commonly used by surgeons to ensure stabilization and consolidation of bone fractures, especially in patients who are at high risk for systematic complications. Both rigid and elastic external fixations are important in the fracture healing process. This study aims to evaluate the behavior of the Orthofix Limb Reconstruction System (LRS)® in the dynamic compression mode. (2) Methods: Experimental and numerical setups were developed using a simplified model of a human tibia which consisted of a nylon bar with a diameter of 30 mm. The bone callus was included in both setups by means of a load cell-based system, which consisted of two carbon epoxy laminated composite plates with a final stiffness of 220 N/mm. The system was evaluated experimentally and numerically, considering different numbers of pins and comparing distances between the external fixator frame and the bone, achieving a good correlation between experimental and numerical results. (3) Results: The results identified and quantified the percental load transferred to the fracture and its sensibility to the distance between the external fixator and bone. Additionally, LRS locking stiffness was evaluated which resulted from the clamp-rail clearances. The results show that the blocking effects of the free clamp movement are directly related to the fixator configuration and are responsible for changes in the amount of load that crosses the bone callus. (4) Conclusions: From the biomechanical point of view, the results suggest that the average bending span of Schanz pins and the weights of the patients should be included into clinical studies of external fixators comparisons purpose.

ACS Style

Ana Martins Amaro; Maria Fátima Paulino; Luis Manuel Roseiro; Maria Augusta Neto. The Effect of External Fixator Configurations on the Dynamic Compression Load: An Experimental and Numerical Study. Applied Sciences 2019, 10, 3 .

AMA Style

Ana Martins Amaro, Maria Fátima Paulino, Luis Manuel Roseiro, Maria Augusta Neto. The Effect of External Fixator Configurations on the Dynamic Compression Load: An Experimental and Numerical Study. Applied Sciences. 2019; 10 (1):3.

Chicago/Turabian Style

Ana Martins Amaro; Maria Fátima Paulino; Luis Manuel Roseiro; Maria Augusta Neto. 2019. "The Effect of External Fixator Configurations on the Dynamic Compression Load: An Experimental and Numerical Study." Applied Sciences 10, no. 1: 3.

Journal article
Published: 14 December 2019 in International Journal of Environmental Research and Public Health
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During recent years the number of tennis athletes has increased significantly. When playing tennis, the human body is exposed to many situations which can lead to human injuries, such as the so-called tennis elbow (lateral epicondylitis). In this work a biomechanical analysis of tennis athletes, particularly during the service, was performed, considering three different types of over-grip and the presence of one anti-vibrator device. One part of the study evaluates the exposure to hand-arm vibration of the athlete, based on the European Directive 2002/44/EC concerning the minimum health and safety requirements, regarding the exposure of workers to risks from physical agents. The second part of the study considers an infrared thermography analysis in order to identify signs of risk of injury, particularly tennis elbow, one of the most common injuries in this sport. The results show that the presence of the anti-vibrator influences the vibration values greatly in the case of athletes with more experience and also for athletes with less performance. The presence of the Cork and/or Tourna on the racket grip does not have any significant effect on the hand-arm vibration (HAV), similarly in the case of athletes with the best performance and athletes with less technique. The results indicated that the infrared thermography technique may be used to identify the risk of injuries in tennis players.

ACS Style

Ana M. Amaro; Maria F. Paulino; Maria A. Neto; Luis Roseiro. Hand-Arm Vibration Assessment and Changes in the Thermal Map of the Skin in Tennis Athletes during the Service. International Journal of Environmental Research and Public Health 2019, 16, 5117 .

AMA Style

Ana M. Amaro, Maria F. Paulino, Maria A. Neto, Luis Roseiro. Hand-Arm Vibration Assessment and Changes in the Thermal Map of the Skin in Tennis Athletes during the Service. International Journal of Environmental Research and Public Health. 2019; 16 (24):5117.

Chicago/Turabian Style

Ana M. Amaro; Maria F. Paulino; Maria A. Neto; Luis Roseiro. 2019. "Hand-Arm Vibration Assessment and Changes in the Thermal Map of the Skin in Tennis Athletes during the Service." International Journal of Environmental Research and Public Health 16, no. 24: 5117.

Abstracts
Published: 25 September 2019 in Clinical Oral Implants Research
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ACS Style

Ana Messias; Pedro Nicolau; Fernando Guerra; Luìs Roseiro; Ana Amaro; Maria Augusta Neto. Pressure induced residual ridge resorption in implant‐assisted removable partial dentures for mandibular Kennedy class I patients – The impact of implant positioning. Clinical Oral Implants Research 2019, 30, 211 -211.

AMA Style

Ana Messias, Pedro Nicolau, Fernando Guerra, Luìs Roseiro, Ana Amaro, Maria Augusta Neto. Pressure induced residual ridge resorption in implant‐assisted removable partial dentures for mandibular Kennedy class I patients – The impact of implant positioning. Clinical Oral Implants Research. 2019; 30 (S19):211-211.

Chicago/Turabian Style

Ana Messias; Pedro Nicolau; Fernando Guerra; Luìs Roseiro; Ana Amaro; Maria Augusta Neto. 2019. "Pressure induced residual ridge resorption in implant‐assisted removable partial dentures for mandibular Kennedy class I patients – The impact of implant positioning." Clinical Oral Implants Research 30, no. S19: 211-211.

Conference paper
Published: 25 September 2019 in VI Latin American Congress on Biomedical Engineering CLAIB 2014, Paraná, Argentina 29, 30 & 31 October 2014
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Removable partial dentures (RPDs) have been considered an acceptable cost-effective solution to restore oral function in partially edentulous patients. However, in mandibular Kennedy class I patients, the RPDs present unfavourable prognosis due to the combined tooth-mucous support with no posterior elements of retention and continuous resorption of the residual ridge. This process is inevitable but highly variable from one individual to the other and modified by both uncontrollable factors and functional or prosthetic factors that determine load distribution and might be subject of modification by the professional. Using the finite element method, the present study performed a biomechanical analysis of a mandibular distal extension removable partial denture regarding prosthesis displacements, strains in the supporting bone and pressure in the mucosa. The results suggest that bone resorption in the alveolar regions is a strain-mediated process whereas in the edentulous areas it is a process induced by pressure in the mucosa.

ACS Style

Ana Messias; Pedro Nicolau; Fernando Guerra; Ana Amaro; Luís Roseiro; Maria Augusta Neto. Residual Ridge Resorption in Mandibular Kennedy Class I Denture Wearers: Proposal of a Pressure-Induced Mechanism Based on a Finite Element Analysis. VI Latin American Congress on Biomedical Engineering CLAIB 2014, Paraná, Argentina 29, 30 & 31 October 2014 2019, 1431 -1440.

AMA Style

Ana Messias, Pedro Nicolau, Fernando Guerra, Ana Amaro, Luís Roseiro, Maria Augusta Neto. Residual Ridge Resorption in Mandibular Kennedy Class I Denture Wearers: Proposal of a Pressure-Induced Mechanism Based on a Finite Element Analysis. VI Latin American Congress on Biomedical Engineering CLAIB 2014, Paraná, Argentina 29, 30 & 31 October 2014. 2019; ():1431-1440.

Chicago/Turabian Style

Ana Messias; Pedro Nicolau; Fernando Guerra; Ana Amaro; Luís Roseiro; Maria Augusta Neto. 2019. "Residual Ridge Resorption in Mandibular Kennedy Class I Denture Wearers: Proposal of a Pressure-Induced Mechanism Based on a Finite Element Analysis." VI Latin American Congress on Biomedical Engineering CLAIB 2014, Paraná, Argentina 29, 30 & 31 October 2014 , no. : 1431-1440.

Conference paper
Published: 25 September 2019 in VI Latin American Congress on Biomedical Engineering CLAIB 2014, Paraná, Argentina 29, 30 & 31 October 2014
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This work presents the numerical results of arthrodesis using a modified bilateral-monoplanar external fixator for the treatment of septic sequelae of the knee joint. The knee arthrodesis serves as an option of salvage treatment for failed total knee arthroplasty procedures [1]. The arthrodesis technique used in this work was promoted with external fixation consisting on the union of two or more femoral pins with two or more tibial pins through bended lateral bars. Biplanar fixation has higher sagittal stability and higher fusion rates than the monoplanar fixation, but the level of compression on the fusion area as well as the extension of contact area can have a great impact on the bone union. Hence, the main purpose of this work is to give the surgeons additional information on how to influence positively the knee arthrodesis, namely relatively to the fixation level, the homogeneity of contact and to the compression level, but also about some possible complications. The arthrodesis technique was implemented using the CAD Solidworks® software and the numerical analysis was carried out on ADINA® software. With this methodology it was possible to recreate the mechanical procedure of the knee arthrodesis and the results indicate that the arthrodesis technique is not only influenced by the parameters associated with the kind of externatal fixator used, but also with the type of supported used to perform the external fixation assembly.

ACS Style

Maria A. Neto; Luis M. Roseiro; Maria F. Paulino; Ana M. Amaro. Numerical Evaluation of the Knee Arthrodesis Using a Modified External Fixator. VI Latin American Congress on Biomedical Engineering CLAIB 2014, Paraná, Argentina 29, 30 & 31 October 2014 2019, 1441 -1445.

AMA Style

Maria A. Neto, Luis M. Roseiro, Maria F. Paulino, Ana M. Amaro. Numerical Evaluation of the Knee Arthrodesis Using a Modified External Fixator. VI Latin American Congress on Biomedical Engineering CLAIB 2014, Paraná, Argentina 29, 30 & 31 October 2014. 2019; ():1441-1445.

Chicago/Turabian Style

Maria A. Neto; Luis M. Roseiro; Maria F. Paulino; Ana M. Amaro. 2019. "Numerical Evaluation of the Knee Arthrodesis Using a Modified External Fixator." VI Latin American Congress on Biomedical Engineering CLAIB 2014, Paraná, Argentina 29, 30 & 31 October 2014 , no. : 1441-1445.