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SSRN 2023年

作者： Junio, Raí Felipe Pereira Cardoso, Robson Luis b. Ramos, Roberto Paulo b. Leão Filha, Elza M. Ribeiro, Mauricio M. Candido, Verônica S. Rodrigues, Jean da S. Silva, Douglas Santos Monteiro, Sergio N. Fujiyama, Roberto T. Federal University of Pará—UFPA Engineering of Natural Resources of the Amazon Program Rua Augusto Corrêa 01 PA BelémCEP 66075-110 Brazil Federal Institute of Education Science and Technology of Pará – IFPA Materials Engineering Program Avenida Almirante Barroso 1155 Marco PA BelémCEP 66093-020 Brazil Federal University of Pará - UFPA Postgraduate Program in Industrial Engineering Rua Augusto Corrêa 01 PA BelémCEP 66075-110 Brazil Federal Institute of Education Science and Technology of Pará – IFPA Estrada do Icuí Guajará PA AnanindeuaCEP 67125-000 Brazil Military Institute of Engineering – IME Department of Materials Science Praça General Tibúrcio 80 Praia Vermelha Urca RJ Rio de JaneiroCEP 22290-270 Brazil

Natural fibres show an increasing potential as reinforcement of polymeric composites, representing a promising concurrent to glass and carbon fibres extensively used in the construction of wind turbine blades synthetic fibres recyclability/disposability and high production energy cost have already been discussed in the main turbine producing centres. In particular, the development of wind turbines for low wind speed areas can increase the energy generation potential of regions not originally eligible for the installation of large turbines. This study proposes the evaluation of the use of jute fibre (Corchorus capsularis) reinforced epoxy composite in the construction of S1210 airfoil profile, of a small-scale wind turbine for low wind speed regions, considering the structural parameters, developed incorporating the Classical Laminate Theory (CLT) and Extended bredt-batho Shear Flow Theory (EbSFT).In order to raise the elastic properties and enable the use of the failure criteria, the composite blades were characterized according to ASTM standards. The mechanical properties surveyed, together with the elastic parameters of the cross section, torsional stiffness, axial stiffness and flexural rigidity, demonstrated the feasibility of using the jute fiber reinforced epoxy composite in the blade construction, evaluated according to the maximum tension failure criterion. © 2023, The Authors. All rights reserved.

关键词： Laminated composites

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Theoretical insights into the chemical bonding, electronic structure, and spectroscopic properties of the lanarkite Pb2SO5 structure

arXiv

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arXiv 2023年

作者： Fabris, Guilherme S.L. Ferrer, Mateus M. Sambrano, Julio R. Almeida, Cláudio R.R. Paskocimas, Carlos A. La Porta, Felipe A. Graduate Program in Materials Science and Engineering Technological Development Center Universidade Federal de Pelotas RS Pelotas96010-610 Brazil Modeling and Molecular Simulation Group São Paulo State University Bauru São Paulo17033-360 Brazil Department of Materials Engineering Federal University of Rio Grande do Norte RN Natal59078-970 Brazil Postgraduate Program in Science and Engineering of Materials Federal University of Rio Grande do Norte RN Natal59078-970 Brazil Federal University of Technology - Paraná Nanotechnology and Computational Chemistry Laboratory Avenida dos Pioneiros 3131 CEP PR Londrina86036-370 Brazil State University of Londrina Post-Graduation Program in Chemistry Rodovia Celso Garcia Cid 445 km 380 CEP PR Londrina86057-970 Brazil

Lanarkite is a mineral formed by a combination of lead, sulphur, and oxygen atoms arranged in the general chemical formula Pb2SO5 (PSO) that crystallises with monoclinic symmetry (belonging to the C2/m space group, No. 12). This mineral was first discovered in Lanarkshire, Scotland and was named after its location. PSO has a unique structure comprising alternating penta-coordinated lead [PbO5] and tetra-coordinated sulphur [SO4] clusters. This lanarkite-type structure has recently attracted significant scientific interest and has been the focus of the superconducting material research community. However, its chemistry needs to be explored further. This article presents a comprehensive investigation on the chemical bonding, electronic structure, and spectroscopic properties of the lanarkite-type PSO structure from a computational perspective. Thus, different functionals in the DFT (e.g., PbE, PbE0, PbESOL, PbESOL0, bLYP, WC1LYP37, and b3LYP) were assessed to accurately predict their fundamental properties. All the DFT calculations were performed using a triple-zeta valence plus polarisation basis set. Among all the DFT functionals tested in this study, PbE showed the best agreement with the experimental data available in the literature. Our results also reveal that the [PbO5] clusters are formed with three Pb–O bond lengths, with values of about 2.32, 2.59, and 2.84 Å, respectively, while the [SO4] clusters have the same S–O bond length of 1.57 Å. We performed a complete topological analysis of this system to comprehend these structural differences. Additionally, the PSO structure has an indirect band gap energy of 2.9 eV and an effective mass ratio (mℎ∗ /me∗) of about 0.415 (using PbE calculations) which may, in principle, indicate a low recombination of electron-hole pairs in the lanarkite structure. Therefore, we believe that a detailed understanding of their electronic structures, spectroscopic properties as well as their chemical bonding is critically important

关键词： Lead compounds

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Spin pumping mechanism in Py/SnTe bilayers: An approach through the magnetoimpedance effect

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Journal of Alloys and Compounds 2025年 1031卷

作者： de Morais, A. Souza, E.C. de Silva, A.L. Gamino, M. da Silva, E.F. Ferreira, A. Vaz, F. Lopes, C. bohn, F. Correa, M.A. Postgraduate Program in Materials Science and Engineering Federal University of Rio Grande do Norte RN Natal59078-970 Brazil Physics Department Federal University of Rio Grande do Norte RN Natal59075-000 Brazil Physics Department Federal University of Pernambuco PE Recife50670-901 Brazil University of Minho 4710-057 Portugal LaPMET - Laboratory of Physics for Materials and Emergent Technologies University of Minho 4710-057 Portugal

Different techniques addressing magnetization dynamics are helpful to estimate parameters of a ferromagnetic thin film nanostructure in the field of spintronics, including Gilbert damping parameter (αG), spin pumping contributions (αSP), two magnons scattering (αTMS), spin mixing conductance (Geff) and others. When considering a bilayer structure, the non-ferromagnetic layer effects need to be carefully selected to tailor an effective spintronic response. Here, the magnetization dynamics are explored in Ni81Fe19(Py)/Ag and Ni81Fe19(Py)/SnTe nanostructures and report the spin mixing conductance from magnetoimpedance experiments. The results are interpreted by considering structural and magnetic characterizations. The spin mixing conductance is estimated as Geff (Py/Ag) = 1.13×1014 cm−2 and Geff (Py/SnTe) = 18.05 ×1014 cm−2, revealing the significant enhancement of Geff when the SnTe acts as a cap layer, indicating that SnTe is a good spin sink. © 2025 Elsevier b.V.

关键词： Ferromagnetism

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Estimation of the main air pollutants from different biomasses under combustion atmospheres by artificial neural networks

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Chemosphere 2024年 352卷 141484页

作者： Monteiro, Thalyssa Oliveira Alves, Pedro Augusto Araújo da Silva de Almeida Nava barradas Filho, Alex Oliveira Villa-Vélez, Harvey Alexander Cruz, Glauber Postgraduate Program in Mechanical Engineering (PPGMEC) Department of Mechanics and Materials Federal Institute of Education Science and Technology of Maranhão (IFMA) Maranhão São Luís Brazil Postgraduate Program in Computer Science and Computational Mathematics (PPG-CCMC) Department of Computer Science University of São Paulo (USP) São Carlos São Paulo Brazil Data Analysis and Artificial Intelligence Laboratory (DARTi) Department of Computational Engineering Federal University of Maranhão (UFMA) Maranhão São Luís Brazil Department of Chemical Engineering Federal University of Maranhão (UFMA) Maranhão São Luís Brazil Processes and Thermal Systems Laboratory (LPSisTer) Department of Mechanical Engineering Federal University of Maranhão (UFMA) Maranhão São Luís Brazil

The production of biofuels to be used as bioenergy under combustion processes generates some gaseous emissions (CO, CO2, NOx, SOx, and other pollutants), affecting living organisms and requiring careful assessments. H... 详细信息

The production of biofuels to be used as bioenergy under combustion processes generates some gaseous emissions (CO, COb>2b>, NOb>xb>, SOb>xb>, and other pollutants), affecting living organisms and requiring careful assessments. However, obtaining such information experimentally for data evaluation is costly and time-consuming and its in situ obtaining for regional biomasses (e.g., those from Northeast brazil (NEb) is still a major challenge. This paper reports on the application of artificial neural networks (ANNs) for the prediction of the main air pollutants (CO, COb>2b>, NO, and SOb>2b>) produced during the direct biomass combustion (Nb>2b>/Ob>2b>:80/20%) with the use of ultimate analysis (carbon, hydrogen, nitrogen, sulfur, and oxygen). 116 worldwide biomasses were used as input data, which is a relevant alternative to overcome the lack of experimental resources in NEb and obtain such information. Cross-validation was conducted with k-fold to optimize the ANNs and performance was analyzed with the use of statistical errors for accuracy assessments. The results showed an acceptable statistical performance for all architectures of ANNs, with 0.001–12.41% MAPE, 0.001–5.82 mg Nm⁻³ MAE, and 0.03–52.30 mg Nm⁻³ RMSE, highlighting the high precision of the emissions studied. On average, the differences between predicted and real values for CO, COb>2b>, NO, and SOb>2b> emissions from NEb biomasses were approximately 0.01%, 10⁻⁶%, 0.14%, and 0.05%, respectively. Pearson coefficient provided consistent results of concentration of the ultimate analysis in relation to the emissions studied and effectiveness of the test set in the developed models. © 2024 Elsevier Ltd

关键词： brazilian northeastern Environmental statistics Evaluation metrics Gaseous emissions Predictive models Thermoconversion

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Pressure-driven homogenization of lithium disilicate glasses

arXiv

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arXiv 2023年

作者： bakhouch, Yasser buchner, Silvio Silveira, Rafael Abel Resende, Leonardo Pereira, Altair Soria Hasnaoui, Abdellatif Atila, Achraf LS2ME Faculté Polydisciplinaire Khouribga Sultan Moulay Slimane University of Beni Mellal B.P 145 Khouribga25000 Morocco Graduate Program in Materials Science Federal University of Rio Grande do Sul Porto Alegre Brazil Department of Material Science and Engineering Saarland University Saarbrücken66123 Germany

Lithium disilicate glasses and glass-ceramics are good potential candidates for biomedical applications and solid-state batteries, and serve as models of nucleation and crystal growth. Moreover, these glasses exhibit a phase separation that influences their nucleation and crystallization behavior. The atomistic mechanisms of the phase separation and their pressure dependence are unclear so far. Here, we used molecular dynamics simulations supported by experiments to assess the spatial heterogeneity of lithium disilicate glasses prepared under pressure. We show that the glass heterogeneity decreases with increasing the cooling pressure and almost disappears at pressures around 30 GPa. The origin of the heterogeneity is due to the attraction between Li cations to form clustering channels, which decreases with pressure. Through our results, we hope to provide valuable insights and guidance for making glass-ceramics with controlled crystallization. Copyright © 2023, The Authors. All rights reserved.

关键词： Phase separation

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Micromobility: Progress, benefits, challenges, policy and regulations, energy sources and storage, and its role in achieving sustainable development goals

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International Journal of Thermofluids 2023年 17卷

作者： Olabi, A.G. Wilberforce, Tabbi Obaideen, Khaled Sayed, Enas Taha Shehata, Nabila Alami, Abdul Hai Abdelkareem, Mohammad Ali Dept. of Sustainable and Renewable Energy Engineering University of Sharjah P.O. Box 27272 Sharjah United Arab Emirates Mechanical Engineering and Design Aston University School of Engineering and Applied Science Birmingham Aston TriangleB4 7ET United Kingdom Center for Advanced Materials Research University of Sharjah PO Box 27272 Sharjah United Arab Emirates Faculty of Engineering Minia University Elminia Egypt Environmental Science and Industrial Development Department Faculty of Postgraduate Studies for Advanced Sciences Beni-Suef University Beni-Suef Egypt

Micromobility is dominant in urban areas, enhancing the transportation sustainability and assisting in fulfilling the United Nations Sustainable Development Goals (SDGs). This work provides an overall assessment of micromobility: its role under SDGs, policy options, micromobility regulations, emerging technologies, utilisation determinants, energy source, and energy storage. The analysis shows that micromobility could play a major role in achieving the SDGs, specifically SDG 3 (Good Health and Well-being) by lowering toxic gas emissions and reducing projected traffic accidents. Also, the effect on SDG 8 (Decent Work and Economic Growth) by reducing the transportation footprint, on SDG 11 (Sustainable Cities and Communities) by increasing transposition accessibility, reducing traffic congestion and improving the air quality, and equally on SDG 12 (Responsible Consumption and Production) by reducing transportation footprint and increase the sources efficiency. Moreover, micromobility affects SDG 13 (Climate Action) by reducing the greenhouse gases. Furthermore, the analysis shows a clear gap in literature and publications on micromobility, especially in energy management and energy storage area. This review shows that new technology of renewable energy and energy storage could play a significant role in achieving the sustainability of micromobility therefore achieving the SDGs. © 2023

关键词： Sustainable development

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Influence of submerged arc welding slag content variation on cementitious materials: A sustainable alternative

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Construction and building materials 2025年 483卷

作者： Castro-Lopes, S. Rodrigues, V.D. Marden, Sandro Peña-Garcia, R. Padrón-Hernández, E. berenguer, Romildo Federal Institute of Education Science and Technology of Pará PA Altamira Brazil Laboratory of Composite Materials and Structural Integrity Corrosion and Biocorrosion - CompoLab/LBC Federal University of Pernambuco PE Recife Brazil Federal University of Paraiba Department of Mechanical Engineering PB Joao Pessoa Brazil Federal Rural University of Pernambuco Postgraduate Program in Physics Engineering Academic Unit of Cabo de Santo Agostinho Cabo de Santo PE Agostinho Brazil Federal University of Pernambuco Department of Physics PE Recife Brazil Polytechnic School University of Pernambuco PE Recife Brazil Federal University of Pernambuco Department of Mechanical Engineering PE Recife Brazil

This study evaluates the effects of submerged arc welding (SAW) slag as a partial replacement for Portland cement in cementitious materials. Cement pastes with 5 %, 10 %, 15 %, 20 %, 25 %, and 30 % SAW slag were tested for compressive strength, tensile strength, carbonation resistance, phase formation, and environmental impact. The results revealed that up to 10 % SAW slag significantly enhanced compressive strength, with the 5 % replacement showing a 20.10 % increase in strength at 28 days compared to the control. The mechanical improvement was attributed to the formation of the CSH phase, which was confirmed by X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Carbonation tests indicated that the 5 % SAW samples reduced carbonation by 5 % compared to the control, while the 10 % SAW samples showed a 1 % reduction. This suggests that SAW slag enhances the resistance of cementitious materials to CO2 attack, improving long-term durability. XRD analysis also identified an increase in amorphous phases in the SAW samples, particularly in the 5 % addition, further supporting the pozzolanic activity of SAW slag. Pozzolanic effectiveness coefficient analysis revealed synergistic effects for SAW slag blends, with optimal performance observed at 5 % replacement, in line with microstructural evidence of enhanced CSH gel formation. Environmental analysis demonstrated that replacing 10 % of Portland cement with SAW slag could reduce CO2 emissions by approximately 4564 kg annually, while a 15 % replacement could lead to a reduction of 6846 kg of CO2. These results underscore the potential of SAW slag as a sustainable and performance-enhancing alternative to conventional cement in concrete production. © 2025 Elsevier Ltd

关键词： Compressive strength

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Computational Characterization of the Recently Synthesized Pristine and Porous 12-Atom-Wide Armchair Graphene Nanoribbon

arXiv

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arXiv 2025年

作者： da Gomes, Djardiel S. Felix, Isaac M. Radel, Willian F. Dias, Alexandre C. Ribeiro Junior, Luiz A. Pereira Junior, Marcelo L. State University of Campinas Gleb Wataghin Institute of Physics Department of Applied Physics Campinas São Paulo13083-859 Brazil University of Brasília Faculty UnB Planaltina Materials Science Postgraduate Program Federal District Brasília Brazil Center for Agri-food Science and Technology Federal University of Campina Grande Paraíba Pombal58840-000 Brazil University of Brasília Institute of Physics Physics Postgraduate Program Federal District Brasília70910900 Brazil Institute of Physics International Center of Physics University of Brasília Federal District Brasília70910-900 Brazil Institute of Physics University of Brasília Federal District Brasília70910-900 Brazil Computational Materials Laboratory University of Brasília Federal District Brasília70910900 Brazil University of Brasília College of Technology Department of Electrical Engineering Federal District Brasília70910-900 Brazil

Recently synthesized Porous 12-Atom-Wide Armchair Graphene Nanoribbons (12-AGNRs) [Nano Lett. 2024, 24, 10718-10723]exhibit tunable properties through periodic porosity, enabling precise control over their electronic, optical, thermal, and mechanical behavior. This work presents a comprehensive theoretical characterization of pristine and porous 12-AGNRs based on density functional theory (DFT) and molecular dynamics (MD) simulations. DFT calculations reveal substantial electronic modifications, including band gap widening and the emergence of localized states. Analyzed within the bethe–Salpeter equation (bSE) framework, optical properties highlight strong excitonic effects and significant absorption shifts. Thermal transport simulations indicate a pronounced reduction in conductivity due to enhanced phonon scattering at nanopores. At the same time, MD-based mechanical analysis shows decreased stiffness and strength while maintaining structural integrity. Despite these modifications, porous 12-AGNRs remain mechanically and thermally stable. These findings establish porosity engineering as a powerful strategy for tailoring graphene nanoribbons’ functional properties, reinforcing their potential for nanoelectronic, optoelectronic, and thermal management *** Codes 00-xx © 2025, CC bY.

关键词： Nanoribbons

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Comparison of Cu−Al−Ni−Mn−Zr shape memory alloy prepared by selective laser melting and conventional powder metallurgy

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Transactions of Nonferrous Metals Society of China 2020年第12期30卷 3322-3332页

作者： Dennis GERA Jonadabe SANTOS Cláudio SKIMINAMI Piter GARGARELLA Postgraduate Program in Materials Science and Engineering Federal University of São CarlosSão CarlosBrazil Materials Engineering Department Federal University of São CarlosR.Washington Luískm 235-SP 310São CarlosBrazil

This work aimed to investigate and critically analyze the differences in microstructural features and thermal stability of Cu−11.3Al−3.2Ni−3.0Mn−0.5Zr shape memory alloy processed by selective laser melting(SLM)and conventional powder *** specimens were produced by sintering 106−180μm pre-alloyed powders under an argon atmosphere at 1060°C without secondary *** specimens were consolidated through melting 32−106μm pre-alloyed powders on a Cu−10Sn *** properties were measured through Vickers hardness *** scanning calorimetry was conducted to assess the martensitic transformation temperatures.X-ray diffraction patterns were collected to identify the metallurgical *** and scanning electron microscopy was used to analyze the microstructural features.b′1 martensite was found,irrespective of the processing route,although coarser martensitic variants were present in *** conventional powder metallurgy samples,intergranular eutectoid constituents and stabilized austenite also formed at room ***-specimens showed similar average hardness values to the SLM-specimens,albeit with high standard deviation linked to the *** specimens processed by SLM showed reversible martensitic transformation(T0=171°C).PM-processed specimens did not show shape memory effects.

关键词： shape memory alloys powder metallurgy additive manufacturing selective laser melting Cu-based alloys

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Synthesis and characterization of ba and Sr celsian ceramics from zeolites obtained from amazonian bauxite waste clay

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Applied Clay science 2025年 275卷

作者： Nayara Aparecida Fonseca Couto bruno Apolo Miranda Figueira Igor Alexandre Rocha barreto Patricia Teresa Souza da Luz Oscar Jesus Choque Fernandez Marcondes Lima da Costa Postgraduate Program in Materials Engineering Federal Institute of Education Science and Technology of Pará 66093-020 Belém Brazil Institute of Geosciences Federal University of Pará 66075-110 Belém Brazil

This study explored the use of bauxite washing clay (bWC), a mining residue from the Amazon region, as a raw material for the synthesis of zeolites, followed by their conversion into barium and strontium celsian ceramics. The bWC, rich in gibbsite and kaolinite, demonstrated significant potential due to its high aluminum and silicon content. Zeolites were synthesized through alkaline activation with 1 M NaOH at 350 °C for 4 h, followed by hydrothermal treatment at 100 °C for 24 h. Ion exchange with ba 2+ and Sr 2+ cations was then performed, and the obtained materials were thermally treated at 1200 °C. The results showed the formation of monoclinic barium celsian with high crystallinity, while Sr-celsian exhibited partial conversion, retaining nepheline as a secondary phase. Monoclinic barium celsian exhibited superior mechanical properties, achieving a compressive strength of 15.9 MPa in compositions with lower silica content, whereas Sr-celsian reached 11.94 MPa. In conclusion, this study highlights the potential of bWC as a valuable and sustainable precursor for advanced ceramic production.

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