131 documents found, page 1 of 14
Syringe irrigation in confluent canals: A sequential computational fluid dynami...
Rito Pereira, Mário; Silva, Goncalo; Semiao, Viriato; Martins, Jorge; Silverio, Vania; Pascoal-Faria, Paula; Duarte, Isabel; Alves, NunoThis study aims to assess the influence of root canal preparation, irrigation needle design and its placement depth in the irrigation flow of confluent canals during syringe irrigation. A mandibular molar presenting two confluent canals in its mesial root was sequentially prepared and scanned by micro-computed tomography after mechanical preparation up to ProTaper Next system sizes X2 (25/.06v), X3 (30/.07v) an...
Dimension Stone Quarries Risk Assessment Estremoz Marbles
Lopes, Luís; Martins, Ruben; Pinho, António; Duarte, Isabel; Faria, PaulaFor centuries, dimension stone marble exploitation from the Estremoz Anticline, south Portugal, leads to a peculiar landscape consisting of hundreds of deep open-pit quarries. In the 80s of the last century, more than 180 quarries operate side-by-side simultaneously. The struggle for interesting outcrops, in addition to private property that legally characterises the mineral masses in Portugal, led to a situati...
Elaboration and experimental characterizations of copper-filled polyamide micro...
Akrout, Mabrouka; Difallah, Basma Ben; Kharrat, Mohamed; Dammak, Maher; Pereira, António B.; Oliveira, Filipe J.; Duarte, IsabelPolyamide 66 (PA66) has been used for dynamic bearing applications due to its good wear and abrasion resistance, hardness, and rigidity. PA66/copper micro-composites were studied with respect to micro-mechanical, tribological, and structural properties. A mixing step followed by injection molding was used to develop the different composites: PA66+5 wt.% Cu, PA66+10 wt.% Cu, and PA66+15 wt.% Cu. The morphologica...
Flash X-ray radiography of internal damage in soft cellular materials during in...
Fíla, Tomáš; Falta, Jan; Koudelka, Petr; Šleichrt, Jan; Krčmářová, Nela; Duarte, IsabelProcesses of internal damage development during localized dynamic penetration represent a crucial mechanism important for relevant analysis of deformation and failure of plates and sandwich panels under high strain rate conditions. Soft cellular materials are of special importance as the internal damage defines mode of collapse and energy absorption capabilities. In this paper, a fast X-ray radiography is emplo...
Relationship between decision-making styles and leadership styles of portuguese...
Rouco, Carlos; Marques-Quinteiro, Pedro; Reis, Vitor; Duarte, IsabelNumerous studies in management and leadership indicate that one’s decision-making style is reflective of one’s leadership style. In the context of civil protection and the fire service, the ability of the fire officers to adopt the best style of decision-making and leadership in each situation represents a critical factor of success. Therefore, the present study was designed to examine the relationship between ...
18Ni300 maraging steel lattice structures fabricated via laser powder bed fusio...
Oliveira, D. F.; Vieira, J. S.; Duarte, Isabel; Vincze, G.; Oliveira, J. M.; Miranda, G.Maraging steels have attracted the attention of the injection molding industry, mainly due to their mechanical properties. However, the use of these steels for complex inserts is still a challenge, given the limitations of conventional subtractive technologies. In this context, additive manufacturing technologies, especially Laser powder bed fusion (LPBF), arise as a solution for the manufacture of maraging ste...
A 3D-Printed Ceramics Innovative Firing Technique: A Numerical and Experimental...
Santos, Tiago; Ramani, Melinda; Devesa, Susana; Batista, Catarina; Franco, Margarida; Duarte, Isabel; Costa, Luis; Ferreira, Nelson; Alves, NunoAdditive manufacturing (AM), also known as three-dimensional (3D) printing, allows the fabrication of complex parts, which are impossible or very expensive to produce using traditional processes. That is the case for dinnerware and artworks (stoneware, porcelain and clay-based products). After the piece is formed, the greenware is fired at high temperatures so that these pieces gain its mechanical strength and ...
On the Structural, Thermal, Micromechanical and Tribological Characterizations ...
Akrout, Mabrouka; Ben Difallah, Basma; Kharrat, Mohamed; Dammak, Maher; Pereira, António; Oliveira, Filipe J.; Duarte, IsabelThe purpose of this work was to investigate the structural, thermal, micromechanical and tribological properties of novel polymer/metal composite materials for bearing applications. Copper (Cu)-filled Acrylonitrile Butadiene Styrene (ABS) composites were mixed in a laboratory scale by an internal mixer with two blade impellers, and then injection-molded. Neat ABS, ABS+5wt% Cu, ABS+10wt% Cu, and ABS+15wt% Cu wer...
Syringe irrigation in confluent canals: A sequential computational fluid dynami...
Rito Pereira, Mário; Silva, Goncalo; Semiao, Viriato; Martins, Jorge N. R.; Silverio, Vania; Pascoal-Faria, Paula; Duarte, Isabel; Alves, NunoThis study aims to assess the influence of root canal preparation, irrigation needle design and its placement depth in the irrigation flow of confluent canals during syringe irrigation. A mandibular molar presenting two confluent canals in its mesial root was sequentially prepared and scanned by micro-computed tomography after mechanical preparation up to ProTaper Next system sizes X2 (25/.06v), X3 (30/.07v) an...
3D-Printed Collagen-Nanocellulose Hybrid Bioscaffolds with Tailored Properties ...
Dobaj Štiglic, Andreja; Lackner, Florian; Nagaraj, Chandran; Beaumont, Marco; Bračič, Matej; Duarte, Isabel; Kononenko, Veno; Drobne, DamjanaHybrid collagen (Coll) bioscaffolds have emerged as a promising solution for tissue engineering (TE) and regenerative medicine. These innovative bioscaffolds combine the beneficial properties of Coll, an important structural protein of the extracellular matrix, with various other biomaterials to create platforms for long-term cell growth and tissue formation. The integration or cross-linking of Coll with other ...