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Artigo 0 Citação(ões) na Scopus Silício: Abundante, eclético, sofisticado(2004-01-04) PAPALEO, R.Artigo 3 Citação(ões) na Scopus Automation course for industrial engineers: An approach based on Petri Nets, software tools and laboratory experiments(2014-01-05) Fabio Lima; PRADO, A. C.; Alexandre Augusto Massote; Fabrizio Leonardi© 2014 TEMPUS Publications.This paper proposes a methodology for teaching industrial automation to Brazilian industrial engineering undergraduate students, based on analysing a computational solution associated with an integrated manufacturing laboratory. As a first approach an analytical analysis of the automated process is carried out. Then the manufacturing laboratory is combined with software tools, to provide the industrial engineering student with a powerful analysis for using these kinds of systems to improve product quality and production performance. For the computational analysis, we have inserted Petri Nets to evaluate the production system performance with a good acceptance from the students. This is the highlight of this work since using Petri Nets for Industrial Engineering undergraduate students is not a common approach. Finally, an assessment proved that such a strategy has been producing excellent learning results.- Crack tunneling effects on the elastic unloading compliance of C(T), SE(B) and clamped SE(T) specimens and correction methodology(2023) ANDRE, L. G. F.; MATTAR NETO, M.; Gustavo Donato© 2023 Elsevier LtdThis paper covers the effects of crack tunneling on SE(B), C(T), and clamped SE(T) specimens and presents a correction methodology for this effect and is divided in two parts. Part one presents an investigation of how crack front curvature affects instantaneous crack size predictions based on the elastic unloading compliance technique. Relative crack depths (a/W) of 0.2, 0.5, and 0.7, were considered alongside five levels of crack curvature. Refined finite element models provided load-CMOD records in order to support compliance assessment. The crack front was modeled as a semi-ellipse, and the compliance results agreed with experimental data from the literature. It was shown that for the same equivalent physical straight crack standardized by ASTM, compliance generally decreases as tunneling increases. Since the maximum crack curvature allowed by the aforementioned standards is very restrictive, compliance did not meaningfully change within that limit, however, if violated, this paper shows that higher deviations may occur, leading to inaccurate crack depth estimations and invalid test results. These limits and deviations were clearly determined and, as a step to improve the techniques, this paper also presents – in part two – an exploration of a possible approach to mitigate this problem, which is based on the modification of how the equivalent straight crack of a curved crack front is determined. This new approach presents reduced errors in compliance-based crack size estimation as crack curvature increases when compared to current standardized protocols, and it can support further investigations in order to validate and standardize improved measuring techniques. Finally, it is important to state that even though the ASTM E1820 is used for the determination of crack driving forces, this study is based only on the study of the crack front curvature, the limit imposed by this standard and the deviations on crack size estimation when those limits are violated, while not focusing on determining errors directly on the J-integral. This paper is a further development on the studies published before by the research group.
- Biomechanical Analysis of Tissue Engineering Construct for Articular Cartilage Restoration—A Pre-clinical Study(2022-04-15) FARIA, R. R. DE; MAIZATO, M. J. S.; CESTARI, I. A.; HERNANDEZ, A. J.; BUENO, D. F.; Roberto Bortolussi; Cyro Albuquerque; FERNANDES, T. L.© 2022, Springer Nature Switzerland AG.The chondral lesion and osteoarthritis are conditions associated with an economic burden, since if left untreated may cause changes in the biomechanics of the joint and result in several injuries considered highly disabling to the individual. Mesenchymal Stem Cells (MSCs) have the immunomodulatory capacity and paracrine signaling that are useful for tissue bioengineering to treat bone and cartilage injuries. To the best of our knowledge, there is no institution in Brazil studying cartilage biomechanical properties in Good Manufacturing Practice (GMP) technique. Therefore, this study aims to describe biomechanics analysis for cartilage restoration by tissue engineering and cell therapy treatments in a GMP translational large animal model. A controlled experimental study in fourteen Brazilian miniature pigs was performed, using scaffold-free Tissue Engineering Construct (TEC) from dental pulp and synovial MSCs with 6 months follow-up. To compare the cartilage with and without TEC, indentation and maximum compressive tests were performed, as well as Finite Element model to simulate the osteochondral block and characterize its properties. The Young’s Modulus of each sample was determined, and the outcomes of maximum compressive test demonstrated the cartilage integrity. The proposed method was feasible and capable to properly evaluate articular cartilage restoration.
- Indoor Airflow Dynamics in Compartmentalized Pneumology Units Equipped with Variable-Thickness MERV-13 Filters(2023-04-05) ALVES, C. G. A.; CHECHI JUNIOR, J. T.; Da SILVA NETO F.B.; ANJOS, G. R.; DOS SANTOS, M. D.; OLIVEIRA, G. P. DE© 2023 by the authors.Infection containment in the post-pandemic scenario became a top priority for healthcare engineering control staffers, especially in pneumology sectors, where the treatment of airborne infectious diseases is frequent. In Brazil, where COVID-19 left a long record of casualties, there is a lack of information on the influence of filtration systems on the maintenance of regulated operational conditions for indoor comfort in hospital environments. This paper has the following objectives: to study arrangements of filtering systems in hospital acclimatization ducts; to verify how filtering characteristics could compromise safety regulations for airflow in hospital environments; and to identify airflow stagnation points that might favor suspended viral concentrations and increase contamination risks. We used the computational fluid dynamics STAR-CCM+© software to perform numerical simulations of different cases of indoor airflow in a model corresponding to a sector of the Lauro Wanderley University Hospital (João Pessoa city, Brazil). We concluded that standards for maximum velocity are reachable despite thinner or thicker filters affecting the spread of the air. In this way, acclimatization systems are limited by a tradeoff between regulation and protection. Our findings are relevant to future technological development, interventions, safety strategies amidst contamination scenarios, and new filtration arrangements in hospital environments.
- Synergism between tribological parameters – “micro-abrasive concentration level”, “micro-abrasive particle type”, and “liquid type” of a micro-abrasive slurry composition on the micro-abrasive wear behaviour of Fe-30Al-6Cr (at.%) iron aluminide alloy(2023-07-15) DE PAULA, A. F. M.; BORGES, D. F. L.; DA SILVA F. C.; ROSSINO, L. S.; MANFRINATO, M. D.; VERMA, V.; LUNA-DOMINGUEZ, J. H.; MAGNABOSCO, R.; SCHON, C. G.; Ronaldo Câmara Cozza© 2023 Elsevier B.V.Observing the importance of intermetallic materials in mechanical and metallurgical applications, the present work investigates the micro-abrasive wear behaviour in a model–carbide reinforced iron aluminide system. Fe–30Al–6Cr (at.%) iron aluminide alloy with carbon additions “as cast” specimen was tested. Micrographs revealed a continuous network of eutectic chromium carbides at the interdendritic regions of the D03 ordered aluminide matrix. AISI 52100 bearing steel sphere of diameter 25.4 mm (1″) was used for wear tests as counter body. Micro-abrasive slurries were prepared with micro-abrasive particles of black silicon carbide – SiC or alumina – Al2O3, with distilled water or glycerin, in four possible combinations of materials ⇒ “Al2O3 + H2O distilled”, “Al2O3 + glycerin”, “SiC + H2O distilled” and “SiC + glycerin”. Further, keeping the normal force constant and together with different levels of micro-abrasive slurries compositions and sliding distances, a factorial experiment was designed. Result analysis showed that wear volume increased with an increase in micro-abrasive slurry concentration, independently of the type of micro-abrasive particle and liquid. However, the micro-abrasive slurries prepared with SiC and distilled water provided larger wear volumes than the volumes of wear reported under the micro-abrasive slurries formulated with Al2O3 and glycerin. The reason is attributed to the high hardness of SiC particles resulting in high abrasion, whereas the Al2O3 – glycerin slurry lubrication effect restricted high wear. Wear micrographs revealed a change in worn surface morphology from “grooving micro-abrasion” to “rolling micro-abrasion” due to an increase in sliding distance and micro-abrasive slurry concentration.
- SCRUM applied to foundry simulation projects(2021-01-05) DE SÁ, D. A.; WILLIAN GOMES, C.; PAULIELI COLOSSETTI, A.; SCHMIDT, J.; RODOLFO ABRAHAM, E.© 2021 SAE International.Process simulation has a growing role in the casting industry, considered as an essential tool by most foundries that aim to develop systems that deliver quality parts, with the highest possible yield and lowest scrap rate. The challenges of performing casting simulation as part of tool construction projects for permanent molds are presented here. Real schedules from tooling companies are analyzed and their bottlenecks are explored. Using the concepts of agile project management and the Scrum framework applied to a cast part, it was possible to verify that integration between tool construction and simulation can increase quality and robustness with no impact to product development time.
- Use of ball-cratering wear test and nanoscratching test to compare the wear resistance of homogeneous and functionally graded titanium nitride thin films(2023-01-05) CARNEIRO DA SILVA F.; DE MATOS MACEDO M.; COSTA MISCIONE J. M.; FONTANA, L. C.; SAGA J. C.; Ronaldo Câmara Cozza; SCHON C. G.© 2022 The Author(s).Homogeneous (HM) and functionally graded (FG) TiN thin films were produced by the grid-assisted magnetron sputtering (GAMS) technique. The joint use of ball-cratering micro-abrasive wear test (BCMA) and nanoscratching (NN) test was proposed and carried out to evaluate the wear resistance of TiN films. The results showed an increase of 33.3% wear resistance in the FG TiN thin film, when compared with the HM TiN thin film. This result was justified by the higher resistance to nucleation and propagation of cracks and higher level of adhesion to the substrate by the FG TiN thin film, validated through the NN tests.
- Assessment of different more-electric and hybrid-electric configurations for long-range multi-engine aircraft(2023-03-15) GIMENEZ, F. R.; Carlos Mady; HENRIQUES, I. B.© 2023 Elsevier LtdIn this study, the characteristics, penalties, gains, and challenges in the electrification and hybridization process for long-range aircraft were investigated. A system and mission analysis was conducted on thermodynamics and cost. A reference aircraft was compared with other more-electric and hybrid-electric versions of the same type. These latter versions may carry batteries to supply the aircraft system and/or engine. A state-of-the-art propulsion and system architecture were also implemented in these innovative aircraft. A full factorial analysis was conducted to vary the battery energy density and the hybridization ratio for the hybrid configurations. A typical mission profile was developed to match the boundary conditions in all cases. The hybrid powertrains were confirmed in our results as exhibiting superior behavior compared to those of the other cases. The least efficient hybrid configuration, which employed an intermediate battery choice, reduced fuel consumption by 10.7% in the conventional aircraft and by 1% in the battery-powered more-electric type. Moreover, both baseline models were surpassed by the worst intermediate-battery hybrid aircraft by 3.6% and 1% in terms of overall mission exergy efficiency. Considering the actual low density of batteries available on the market, long-range hybrid-electric aircraft will require substantial time to become viable.
- Tissue Engineering and Cell Therapy for Cartilage Repair: Preclinical Evaluation Methods(2022-02-05) SANTANNA, J. P. C.; FARIA, R. R.; ASSAD, I. P.; PINHEIRO, C. C. G.; AIELLO, V. D.; Cyro Albuquerque; Roberto Bortolussi; CESTARI, I. A.; MAIZATO, M. J. S.; HERNANDEZ, A. J.; BUENO, D. F.; FERNANDES, T. L.A chondral injury is a limiting disease that can affect the quality of life and be an economic burden due to the cost of immediate treatment and loss in work productivity. If left untreated, such an injury may progress to osteoarthritis, a degenerative and debilitating joint disease characterized by pain and functional impairment. Mesenchymal stromal cells (MSCs), which have immune-modulatory properties and the ability to differentiate into chondroblasts and osteoblasts, are a predictable source for the treatment of cartilage injuries. This article presents tools to evaluate cartilage restoration by tissue engineering and cell therapy treatment in a translational and preclinical large animal model. In this controlled experimental study with 14 miniature pigs, a scaffold-free tissue engineering construct (TEC) derived from dental pulp and synovial MSCs for cartilage therapy was tested. Total thickness cartilage defects were performed in both posterior knees. The defect was left empty in one of the knees, and the other received the TEC. The tissue repair was morphologically assessed by magnetic resonance imaging (MRI) using the three-dimensional double echo steady-state (3D-DESS) sequence, and compositional assessment was carried out based on the T2 mapping technique. The osteochondral specimens were fixed for histopathology, decalcified, subjected to standard histological processing, sectioned, and stained with hematoxylin and eosin. The sections stained for immunohistochemical detection of collagen types were digested with pepsin and chondroitinase and incubated with antibodies against them. The mechanical evaluation involved analysis of Young's modulus of the cartilage samples based on the indentation and maximum compression test. In addition, a finite element model was used to simulate and characterize properties of the osteochondral block. At 6 months after surgery, there were no complications with the animals and the MRI, histological, immunohistochemical, and biomechanical evaluations proved to be effective and qualified to differentiate good quality chondral repair from inadequate repair tissue. The proposed methods were feasible and capable to properly evaluate the defect filled with TEC containing stromal cells after 6 months of follow-up in a large animal model for articular cartilage restoration. Impact Statement Articular chondral injuries are prevalent and represent an economic burden due to the cost of treatment. The engineering of cartilage tissue can promote the repair of chondral injuries and is dependent on selecting appropriate cells and biocompatible frameworks. In this article, methods for evaluation of a scaffold-free cell delivery system made from mesenchymal stromal cells were present in a translational study that allows further clinical safety and efficacy trials.