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Interface Performance of Untreated Dracaena trifasciata Fibers in Epoxy Composites

Fibers and Polymers 2025年 1-10页

作者： Minillo, Larissa Queiroz Fabiche, Mariana Natale Fiorelli Ambrosio, Vanessa Carolina Lombardi de Castro Cardoso, Bruno César Ortenzi, Altibano Post-Graduate Program in Materials Science and Engineering Federal University of Paraná Curitiba Brazil Post-Graduate Program in Civil Engineering and Building Technology State University of Maringá Umuarama Brazil Post-Graduate Program in Civil Engineering State University of Londrina Londrina Brazil Post-Graduate Program in Construction Management and Building Technologies University of Western São Paulo Presidente Prudente Brazil

This study evaluates the potential of Dracaena trifasciata (DT) fibers as reinforcement in epoxy composites by analyzing mechanical, thermal, and microstructural properties. Fibers underwent water-retting and drying, and were characterized via SEM and FTIR. Composites were fabricated by vacuum infusion with 55% fiber volume fraction and tested according to ASTM D638. Two epoxy systems were investigated: a rigid matrix (LY5052) and a flexible matrix (AR324). With LY5052, DT fiber incorporation led to a 101% increase in elastic modulus but caused a 26% reduction in tensile strength, attributed to stress concentration at the fiber–matrix interface and brittle matrix behavior. In contrast, composites with AR324 exhibited a 908% increase in stiffness and nearly 1000% improvement in tensile strength, enabled by superior strain compatibility between the flexible matrix and the fiber reinforcement. TGA analysis showed thermal stability above 400 °C and ~ 5% increase in residual mass due to inorganic components in DT fibers. SEM revealed predominant fiber pull-out, 40 µm voids, and resin penetration into the fiber lumen. These findings highlight the importance of matrix selection in maximizing the mechanical potential of natural fibers. DT/epoxy composites are promising for lightweight applications, particularly when paired with ductile matrices that mitigate premature failure mechanisms.

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Injectable Platelet-Rich Fibrin in Contact with Bone Substitutes, Porous Zirconia, or Laser-Textured Implant Surfaces: A Detailed Morphological Analysis

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Biomedical materials and Devices 2024年第1期2卷 415-426页

作者： Oliveira, Miguel Noronha Varela, Hugo Almeida Nascimento, Rubens M. Sahoo, Narayan Carvalho, Oscar Henriques, Bruno Souza, Júlio C. M. Ceramic and Composite Materials Research Group (CERMAT) Department of Mechanical Engineering (EMC) Federal University of Santa Catarina (UFSC) Post-graduate Program in Materials Science and Engineering Federal University of Rio Grande Norte (UFRN) Center for MicroElectroMechanical Systems (CMEMS-UMINHO) Universidade do Minho LABBELS - Associate Laboratory University of Minho University Institute of Health Sciences (IUCS) CESPU

The aim of the present study was to perform a detailed morphological analysis of an injectable platelet rich fibrin after combination with two different particulate hydroxyapatite-based granules, a porous zirconia block, and laser-textured zirconia or titanium surfaces. Blood samples were harvested from three participants to prepare the flowable injectable PRF in contact or not with particulate hydroxyapatite (Hap), bone mineral granules (DBBM), porous zirconia blocks, laser-textured titanium or zirconia surfaces. Optical and scanning electron microscopy (SEM) were used to evaluate the fibrin network density, fibrin fibers’ diameter, blood cells, and the interaction of PRF with the biomaterials. Histomorphometry of the flowable PRF was also performed using the hematoxylin–eosin staining protocol. Specimens were independently evaluated by two blinded and well-trained researchers in histomorphometry and microscopy. Particulate Hap and DBBM shown different morphological aspects by SEM analyses since DBBM revealed macro- and micro-scale pores while Hap revealed a dense structure. Hydroxyapatite and DBBM granules were entirely embedded by the fibrin-network in the presence of leukocytes and blood platelets. The zirconia porous structured was filled with PRF and its components. Also, the laser-structured zirconia or implant surfaces were entirely coated with the PRF fibrin network embedding leukocytes and blood platelets. Laser-textured titanium surfaces revealed macro- and micro-scale irregularities that increase the surface area and retention of the injectable PRF. Histomorphometric analyses revealed complementary details on the distribution of lymphocytes, red blood cells, and fibrin associated with platelet aggregation. The flowing and viscosity of an injectable platelet rich fibrin provided an agglomeration of synthetic or xenogeneic particulate bone substitutes and the coating of porous zirconia and textured implant surfaces as inspected by scanning electron microsc

关键词： Bone healing Bone substitutes Histology Morphology Platelet-rich fibrin

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Sodium niobate with high photocatalytic activity for the removal of organic dye and inactivation of Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae bacteria: the effect of Zn doping on these properties

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Ceramics International 2025年

作者： Fernandes, Daiane Raubach, Cristiane Trassante, Carla Dias, Vagner Melo, Luize Silveira, Marcelle Carvalho, Ramon Moreira, Mario Jardim, Pedro Ferrer, Mateus Giongo, Janice Vaucher, Rodrigo Longo, Elson Cava, Sergio Post-Graduate Program in Materials Science and Engineering Federal University of Pelotas RS Pelotas96010-610 Brazil Post-Graduate Program in Microbiology and Parasitology Federal University of Pelotas RS Capão do Leão96160-000 Brazil Post-Graduate Program in Physics Federal University of Pelotas RS Capão do Leão96160-000 Brazil Functional Materials Development Center São Carlos Federal University SP São Carlos13565-905 Brazil

NaNbO3 doped with Zn (0.00, 0.02, and 0.05 mmol) was synthesized by the microwave-assisted hydrothermal method. Photocatalytic and antibacterial activities were investigated. X-ray diffraction revealed the coexistence of two orthorhombic symmetries (P21ma and Pbma), with doping promoting a progressive increase in the Pbma fraction. All samples exhibited a fiber-like shape (diameter of ∼200 nm), which remained unchanged with doping. The low Zn content (0.02 mmol) reduced the band gap energy from 3.08 to 2.95 eV. As a result, this sample exhibited superior photocatalytic activity, achieving 100 % RhB dye degradation within 45 min, under UV light. Scavenger tests revealed that hydroxyl radicals, holes, and superoxide radical anions were the main active species involved in the photocatalytic reaction. Additionally, the photocatalyst demonstrated excellent recyclability over three consecutive cycles. Pure NaNbO3 exhibited strong antibacterial activity, completely inhibiting the growth of S. aureus, E. coli, and K. pneumoniae at the tested concentrations. Although the Zn-doped sample also demonstrated antibacterial action, the response was concentration-dependent. This study is the first report on Zn doping in NaNbO3, as well as the first investigation of its antibacterial activity against K. pneumoniae and S. aureus. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Escherichia coli

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Evaluation of Single and Duplex Plasma Treatment Applied to Aisi 409 Stainless Steel

SSRN

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SSRN 2024年

作者： do Monte e Silva, André Felipe Soares de Almeida, Larissa Solano Monteiro, Leandro Rossino, Luciana Sgarbi Nunes, Maelson Sousa Libório, Maxwell Santana de Carvalho Costa, Thércio Henrique Bandeira, Rafael Marinho de Sousa, Rômulo Ribeiro Magalhães Post-Graduate Materials Science and Engineering Program Federal University of Piauí PI Teresina Brazil Post-Graduate Program in Materials Science Federal University of São Carlos São Carlos Brazil Post-Graduate Program in Chemistry Federal University of Piauí PI Teresina Brazil School of Science and Technology Federal University of Rio Grande do Norte RN Natal Brazil Brazil Department of Mechanical Engineering Federal University of Piauí PI Teresina Brazil Brazil

The industrial landscape has witnessed a growing demand for components exhibiting superior performance and extended lifespan, especially in parts made of stainless steels like AISI 409 steel, widely used in automotive exhaust systems, heat exchangers, and lightweight structural components. This study investigates the enhancement of surface properties of AISI 409 stainless steel through cathodic cage plasma nitriding (CCPN) and cathodic cage plasma deposition (CCPD) processes, focusing on the novel implementation of duplex treatments. The research aims to improve the mechanical strength, wear resistance, and corrosion resistance of the steel by forming nitrides and vanadium nitride films on its surface. The duplex treatments, specifically N400D450 and N450D450, were found to significantly enhance the hardness of AISI 409 stainless steel, with the N450D450 sample achieving a maximum hardness of 1100 HV—a 461.22% increase compared to the untreated steel. This enhancement is attributed to the formation of a thick, uniform nitrided layer followed by a vanadium nitride film. The critical role of processing order was highlighted, with the sequence of nitriding followed by deposition proving more effective than the reverse. Corrosion resistance was markedly improved in the duplex-treated samples. The N450D450 sample exhibited an Ecorr of -198 mV and reduced jcorr values, indicating superior resistance to corrosive environments. These results underscore the synergistic effect of combining nitriding and vanadium deposition, which optimizes the formation of protective surface layers. Overall, this study demonstrates that duplex treatments significantly enhance the surface properties of AISI 409 stainless steel, offering the potential for extended component lifespan and reduced maintenance in industrial applications. The findings suggest that careful control of process parameters and treatment sequence is essential for achieving optimal results. © 2024, The Authors. All rights

关键词： Tribology

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Fatigue survival of endodontically treated teeth restored with different fiber-reinforced composite resin post strategies versus universal 2-piece fiber post system: An in vitro study

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Journal of Prosthetic Dentistry 2023年第3期129卷 456-463页

作者： Penteado, Marcela Moreira de Andrade, Guilherme Schmitt Araujo, Rodrigo Máximo Borges, Alexandre Luiz Souto Valandro, Luiz Felipe Pereira, Gabriel Kalil Rocha da Silva, João Maurício Ferraz PhD student Department of Dental Materials and Prosthodontics Institute of Science and Technology São Paulo State University UNESP SP São José dos Campos Brazil Assistant Professor Department of Dental Materials and Prosthodontics Institute of Science and Technology São Paulo State University UNESP SP São José dos Campos Brazil Associate Professor Department of Dental Materials and Prosthodontics Institute of Science and Technology São Paulo State University UNESP SP São José dos Campos Brazil Associate Professor MSciD PhD Post-Graduate Program in Oral Science Faculty of Dentistry Federal University of Santa Maria UFSM RS Santa Maria Brazil Adjunct Professor MSciD-PhD Post-Graduate Program in Oral Science Faculty of Dentistry Federal University of Santa Maria UFSM RS Santa Maria Brazil

Statement of problem: Various strategies have been proposed to reduce the cement space of foundation restorations for endodontically treated teeth. However, they may add more operative steps, or the dentist must keep different sizes of drills and posts in stock. A 2-piece universal adjustable post system has been developed to overcome this problem, but whether the system has acceptable fatigue survival performance is unclear. Purpose: The purpose of this in vitro study was to evaluate the fatigue survival and stress distribution of endodontically treated teeth without a ferrule and restored with different glass fiber post strategies versus a recently introduced universal 2-piece fiber post system. Material and methods: Bovine incisor roots were randomly assigned to 3 groups as per the post used (n=13): adapted glass fiber post with post space preparation of the same size, composite resin-custom glass fiber post (CTM), and universal 2-piece glass fiber-reinforced composite resin post (UNI). The posts were adhesively luted, the composite resin core was added, and a composite resin crown was produced with computer-aided design and computer-aided manufacturing (CAD-CAM), and then adhesively luted to each core. A fatigue test was performed with the stepwise stress method (10 000 cycles/step;20 Hz;load=100 N to 750 N;step=50 N) until fracture, and the failure mode analyzed. The stress distribution was evaluated by finite element analysis with the maximum principal stress criteria by following the parameters of the in vitro test. The solids were considered homogeneous, linear, and isotropic, except for the glass fiber post (orthotropic), and a load of 450 N at 30 degrees was applied. The fatigue failure load and the number of cycles for failure were analyzed with Kaplan-Meier and Mantel-Cox (log rank test) (α=.05). The finite element analysis results were analyzed with colorimetric graphs. Results: The highest fatigue failure load and the number of cycles for failure were

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Two Phase Dip-Coating Method: Growth Mechanisms and Effects on Electrical Properties of Tio2 and Tio2/Sno2

SSRN

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SSRN 2023年

作者： Pedrini, Luiz Felipe K. de Andrade Scalvi, Luis Vicente School of Sciences POSMAT - Post-Graduate Program in Materials Science and Technology SP Bauru Brazil School of Sciences Department of Physics SP Bauru Brazil

A dip-coating process is proposed for preparation of TiO2 thin films from a segregated fluid system. To study its effects, by changing the height of the floating, less dense phase, it was possible to modify the main draining mechanism, which has decreased agglomerate size during gelification process. By reducing the amount of volume adhered to the emerging substrate it was possible to shift the draining regime mechanism towards the capillary regime, a change mostly observed before only in slower emerging deposition rates. It was also found that further reduction in adhered volume decreased the size of agglomerates during deposition, which affected transparency and electrical conductivity of prepared films. A further increase in floating phase height was shown to lower roughness in film surface. This has lead to a better coupled interface in TiO2/SnO2 heterostructure, as seen by type II hererojunction behavior, when TiO2 films, deposited on top of a SnO2 films, are prepared with solutions with 0.6 cm of floating phase height. © 2023, The Authors. All rights reserved.

关键词： Titanium dioxide

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Growth of Wafer-Scale Single-Crystal 2D Semiconducting Transition Metal Dichalcogenide Monolayers

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Advanced science 2024年第11期11卷 e2307839页

作者： Singh, Jitendra Astarini, Nadiya Ayu Tsai, Meng-Lin Venkatesan, Manikandan Kuo, Chi-Ching Yang, Chan-Shan Yen, Hung-Wei Department of Materials Science and Engineering National Taiwan University of Science and Technology Taipei City106335 Taiwan Department of Physics Udit Narayan Post Graduate College Padrauna Uttar Pradesh Kushinagar274304 India Department of Molecular Science and Engineering Institute of Organic and Polymeric Materials National Taipei University of Technology Taipei City106344 Taiwan Institute and Undergraduate Program of Electro-Optical Engineering National Taiwan Normal University Taipei City11677 Taiwan Department of Materials Science and Engineering National Taiwan University Taipei City106319 Taiwan

Due to extraordinary electronic and optoelectronic properties, large-scale single-crystal two-dimensional (2D) semiconducting transition metal dichalcogenide (TMD) monolayers have gained significant interest in the development of profit-making cutting-edge nano and atomic-scale devices. To explore the remarkable properties of single-crystal 2D monolayers, many strategies are proposed to achieve ultra-thin functional devices. Despite substantial attempts, the controllable growth of high-quality single-crystal 2D monolayer still needs to be improved. The quality of the 2D monolayer strongly depends on the underlying substrates primarily responsible for the formation of grain boundaries during the growth process. To restrain the grain boundaries, the epitaxial growth process plays a crucial role and becomes ideal if an appropriate single crystal substrate is selected. Therefore, this perspective focuses on the latest advances in the growth of large-scale single-crystal 2D TMD monolayers in the light of enhancing their industrial applicability. In the end, recent progress and challenges of 2D TMD materials for various potential applications are highlighted. © 2023 The Authors. Advanced science published by Wiley-VCH GmbH.

关键词： Single crystals

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Effect of Fe on the Photo/Piezocatalytic Activity of Bazr1-2xfe2xo3-Δ Ceramics

SSRN

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SSRN 2023年

作者： Fernandes, Daiane Hernandes, Paola Gay Moreira, Mario Lucio Raubach, Cristiane Wienke Jardim, Pedro Lovato Gomes Ferrer, Mateus Meneghetti Moreira, Eduardo Ceretta Mastelaro, Valmor Roberto Cava, Sergio da S. Post-Graduate Program in Materials Science and Engineering Federal University of Pelotas RS Pelotas96010-610 Brazil Post-Graduate Program in Physics Federal University of Pelotas RS Capão do Leão96160-000 Brazil Spectroscopy Laboratory Federal University of Pampa RS Bagé96413-172 Brazil Physics Institute São Paulo University SP São Carlos13560-970 Brazil

BaZr1-2xFe2xO3-δ (x=0.00, 0.02, 0.04 and 0.08) samples were prepared by microwave-assisted hydrothermal method quickly and at low-temperature. Furthermore, we explored for the first time the effect of iron (Fe) in the barium zirconate (BZO) lattice on photocatalytic and piezocatalytic activity to degrade organic dye. Fe insertion reduced the band gap, altered the electronic structure and induced luminescence quenching. The catalytic activity of the samples was analyzed through the degradation of the rhodamine B (RhB) dye. The photocatalytic experiment was performed under UVC light and the piezocatalytic experiment under ultrasonic vibration. The pure sample of BZO showed better photocatalytic performance, while the insertion of Fe was unfavorable to degrade RhB. In contrast, pure BZO has negligible piezocatalytic activity, but a low Fe content is highly beneficial for promoting piezocatalysis. Based on the findings, this study provides important information for obtaining effective photocatalysts and piezocatalysts to be used in environmental remediation. © 2023, The Authors. All rights reserved.

关键词： Iron

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Effect of Fe on the Photo/Piezocatalytic Activity of Bazr1-2xfe2xo3-Δ Ceramics

SSRN

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SSRN 2023年

作者： Fernandes, Daiane Hernandes, Paola Gay Moreira, Mario Lucio Raubach, Cristiane Wienke Gomes Jardim, Pedro Lovato Ferrer, Mateus Meneghetti Moreira, Eduardo Ceretta Mastelaro, Valmor Roberto Cava, Sergio da S. Post-Graduate Program in Materials Science and Engineering Federal University of Pelotas RS Pelotas96010-610 Brazil Post-Graduate Program in Physics Federal University of Pelotas RS Capão do Leão96160-000 Brazil Spectroscopy Laboratory Federal University of Pampa RS Bagé96413-172 Brazil Physics Institute São Paulo University SP São Carlos13560-970 Brazil

关键词： Temperature

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Multipurpose Silicon-Based Toothpastes: Decision Making for a Better Oral Health

European Dental Research and Biomaterials Journal

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European Dental Research and Biomaterials Journal 2023年第1/02期03卷 001-002页

作者： Fabiano Vieira Vilhena Paulo Henrique Perlatti D'Alpino Trials Research and Development Inc. São Paulo SP Brazil Triplet Biotechnology Solutions São Paulo SP Brazil São Paulo State University (UNESP) School of Sciences POSMAT – Post-Graduate Program in Materials Science and Technology Bauru SP Brazil

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