Use of recycled aggregates from civil construction in self-compacting mortar Fernanda Rodrigues Santos Valle, Paulo Cesar Gonçalves, Maria Gabriela A. Ranieri, Mirian de Lourdes Noronha Motta Melo, Valquíria Claret dos Santos Revista Ibracon De Estruturas E Materiais, 2022 The utilization of wastes from demolition in civil construction in self compacting concrete (SCM) has the potential to reduce both the environmental impact and financial cost. In this context, this article aims to verify the behavior of the incorporation of recycled aggregates of civil construction in the mix designs of self-compacting mortar (SCM) in replacing cement, presenting as an interesting alternative to natural raw materials. This study used the EMMA® software to optimize the choice of percentages of fine recycled aggregates when replacing cement. The proportions chosen were 0%, 5%, 15%, and 25%, through the analysis of the granular packing curve of the respective mix designs. The proportion of 0% has in its composition cement, metakaolin, sand, superplasticizer (SP) and water. The parameters obtained, through tests in the fresh state of the mini-slump and mini-funnel V, certified the samples as SCM. The compressive strength and flexural tensile strength tests in the hardened state demonstrated a reduction in mechanical properties of the material with cement replacement. It is concluded that the waste used brick and ceramic can be added in replacement to the cement in SCM without significant loss of properties in the fresh and hardened state.
Physical and chemical properties of waste foundry exhaust sand for use in self-compacting concrete Maria Auxiliadora de Barros Martins, Lucas Ramon Roque da Silva, Maria Gabriela A. Ranieri, Regina Mambeli Barros, Valquíria Claret dos Santos, et al. Materials, 2021 The reuse of waste in civil construction brings environmental and economic benefits. However, for these to be used in concrete, it is necessary a previous evaluation of their physical and chemical characteristics. Thus, this study aimed to characterize and analyze the waste foundry exhaust sand (WFES) for use in self-compacting concrete (SCC). Foundry exhaust sand originates from the manufacturing process of sand molds and during demolding of metal parts. It is a fine sand rich in silica in the form of quartz collected by baghouse filter. Characterization of WFES was conducted through laser granulometry, scanning electron microscopy (SEM) in the energy dispersive spectroscopy (EDS) mode, X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG) and derivative thermogravimetry (DTG) techniques. The waste was classified as non-hazardous and non-inert, with physical and chemical properties suitable for use in SCC composition, as fine aggregate or mineral addition. Five mixtures of SCC were developed, in order to determine the waste influence in both fresh and hardened concrete. The properties in the fresh state were reached. There was an increase in compressive strength and sulfate resistance, a decrease in water absorption of self-compacting concrete by incorporating WFES as 30% replacement.
Resistive switching and multiferroic behavior of La0.5Pr0.5FeO3 ferrite thin films M.G.A. Ranieri, P.P. Ortega, H. Moreno, M.A. Ramirez, E.C. Aguiar, et al. Journal of Alloys and Compounds, 2021 This study examines resistive switching behavior and magnetoelectric coupling in La0.5Pr0.5FeO3 thin films obtained through the polymeric precursor method at a temperature of 500 °C for 2 h. The real and imaginary part of dielectric constant (e′ and e″) as a function of temperature demonstrate significant values with increasing temperature and can be caused by the ferroelectric ordering in the present system. The magnetic and dielectric measurements suggest a coupling between magnetic and electric dipoles at room temperature. The magnetization versus temperature curves under zero-field cooling (ZFC) and field cooling (FC) conditions suggest antiferromagnetic to ferromagnetic transition. The maximum magnetoelectric coupling value is ∼0.06 for H ∼1.7 T. By varying the applied electric field, we noted the resistive memory phenomenon from current-voltage (I–V) characteristics being reversibly switched between two stable resistance states. Such behavior can be ascribed to the electron hopping from Fe2+ to Fe3+ levels with oxygen vacancies present in the lattice, as evidenced using XPS analysis. These state-of-art analyses motivated us to study the introduction of praseodymium (Pr) in La3+ sites, considering that LaFeO3 shows paramagnetic behavior at room temperature. La0.5Pr0.5FeO3 thin films exhibited slightly ferromagnetic behavior associated with coupling between cations at the octahedral and tetrahedral sites with the coexistence of resistive switching and magnetoelectric coupling behavior.
Optimization of anodization parameters in Ti-30Ta alloy Patricia Capellato, Daniela Sachs, Lucas V. B. Vasconcelos, Miriam M. Melo, Gilbert Silva, et al. Metals, 2020 The current metallic biomaterial still presents failures associated with the bulk alloy and the interface of material/human body. In previous studies, titanium alloy with tantalum showed the elastic modulus decrease in comparison with that of commercially pure (cp) titanium. In this study, surface modification on Ti-30Ta alloy was investigated. Titanium and tantalum were melted, homogenized, cold-worked by a rotary swaging process and solubilized. The anodization process was performed in electrolyte contained glycerol + NH4F 0.25% at 30 V using seven different durations—4 h, 5 h, 6 h, 7 h, 8 h, 9 h, and 10 h and annealed at 530 °C for 1 h. The surface topography was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) measurements, X-ray diffraction analysis (XRD), and contact angle. From the results, we conclude the time of anodization process influences the shape and morphology of the anodized layer. The 5 h-anodization process produced a smooth and porous surface. The 4-, 6-, 7-, 8-, 9-, and 10-h conditions showed nanotubes morphology. All surfaces are hydrophilic (<90°). Likewise, all the investigated conditions present anatase phase. So, this surface modification presents potential for biomedical application. However, more work needs to be done to better understand the influence of time on the anodization process.
La0.5Sm0.5FeO3: a new candidate for magneto-electric coupling at room temperature M. G. A. Ranieri, M. Cilense, E. C. Aguiar, A. Z. Simões, M. A. Ponce, et al. Journal of Materials Science Materials in Electronics, 2017 Samarium substituted lanthanum orthoferrite La0:5Sm0:5FeO3 thin film has been prepared by soft chemical method. A single perovskite phase with orthorhombic crystallographic structure was attained. Magnetic and ferroelectric orderings of the film is observed at room temperature (RT). The magnetization of the sample measured at room temperature increases non-linearly with the increase of magnetic field, which suggests the presence of dipole–dipole/exchange interaction in the sample. The resistivity measured in the temperature range 25–375 °C showed that the film is a semiconducting material with low resistivity. The Cole–Cole model reveals different grain boundaries electrical resistance caused by the equilibrium concentration of oxygen vacancies in orthoferrite and that the addition of samarium results in loss of oxygen during sintering. The ferroelectric behaviour of La0:5Sm0:5FeO3 at RT is also confirmed by its capacitance–voltage (C–V) characteristic suggesting a weak ferroelectric behaviour at room temperature. The variation of dielectric constant as a function of frequency predicts the presence of spontaneous polarization in the sample. The semiconductor electrical behavior of the La0:5Sm0:5FeO3 is mainly composed of tunneling current.
Magnetoelectricity at room temperature in the LaFeO3/BiFeO3 heterostructures M. G. Ranieri, R. A. C. Amoresi, M. A. Ramirez, J. A. Cortes, L. S. R. Rocha, et al. Journal of Materials Science Materials in Electronics, 2016 Thin films of BiFeO3 (BFO), LaFeO3 (LFO), and LFO/BFO heterostructures were successfully obtained on Pt/TiO2/SiO2/Si(100) substrates by chemical solution deposition. The films were characterized by structural, morphological and magneto-electrical techniques. The polycrystalline films obtained with good crystalline phases of BFO and LFO. The heterostructures films LFO/BFO showed no diffusion between the phases, and without the presence of secondary phases. The bottom layer of LFO was able to promote the grain growth, reducing oxygen vacancies, and influenced the tension between the new interfaces of the subsequent layer of BFO, thereby altering the physical and chemical properties obtained in the heterostructure. These show the coexistence of ferroelectricity and magnetism in the material. Measurements of capacitance and electrical polarization as a function of the magnetic field have been made and have indicated the magnetic–electric coupling at room temperature with high dielectric constant. Such materials may be of great significance in basic as well as applied research.
Electrical behavior of chemically grown lanthanum ferrite thin films M.G.A. Ranieri, M. Cilense, E.C. Aguiar, C.C. Silva, A.Z. Simões, et al. Ceramics International, 2016 Perovskite structured oxides are important functional materials often used for the development of modern devices. To extend their applicability, these materials need to be scalably and efficiently grown in the form of thin films. In this work, perovskite structured thin films of nanograined LaFeO3 (LFO) were chemically grown using polymeric precursors on Pt substrates. The thin films were characterized by X-ray diffraction, field-emission scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. The electrical properties of the films were also measured. The homogeneous LFO thin films synthesized at a sintering temperature of 500 °C in 2 h contained grains with lateral dimensions of about 68 nm and 356 nm in thickness. The dielectric permittivity and dielectric loss measurements of the sample indicated only a slight dispersion in the frequency because of the lower two-dimensional stress in the plane of the film. The nanograined LFO semiconductor thin films showed a room temperature magnetic coercive field, which rendered them magnetically soft. The electrical characterization of the films, including temperature-dependent conductivity and thermopower confirmed p-type conduction and the mobility activation energy was measured to be 0.96 eV. A strong magnetization with a remnant magnetization of ~60 emu/g was observed in the LFO films, indicating the uncompensated spin magnets moments of the Fe3+ ions.
Influence of processing route on electrical properties of Bi<inf>4</inf>Ti<inf>3</inf>O<inf>12</inf> ceramics obtained by tape-casting technology M.G.A. Ranieri, E.C. Aguiar, M. Cilense, B.D. Stojanovic, A.Z. Simões, et al. Materials Research Bulletin, 2015 Highlights: • Bi{sub 4}Ti{sub 3}O{sub 12} thick films were obtained by SSR and PPM methods. • Both systems crystallize in an orthorhombic structure. • Textured characteristics were evidenced. • Grain morphology affects the P–E loops. - Abstract: Bismuth titanate powders (Bi{sub 4}Ti{sub 3}O{sub 12}-BIT) were fabricated by solid state reaction (SSR) and polymeric precursor method (PPM). From these powders, Bi{sub 4}Ti{sub 3}O{sub 12} pellets were obtained by tape-casting using plate-like templates particles prepared by a molten salt method. The BIT phase crystallizes in an orthorhombic structure type with space group Fmmm. Agglomeration of the particles, which affects the densification of the ceramic, electrical conduction and leakage current at high electric fields, was monitored by transmission electronic microscopy (TEM) analyses. FEG-SEM indicated that different shape of grains of BIT ceramics was influenced by the processing route. Both SSR and PPM methods lead to unsaturated P–E loops of BIT ceramics originating from the highly c-axis orientation and high conductivity which was affected by charge carriers flowing normally to the grain boundary of the crystal lattice.
Fabrication and structural characterization of bismuth niobate thin films grown by chemical solution deposition L. F. Goncalves, J. A. Cortés, M. G. A. Ranieri, F. B. Destro, M. A. Ramirez, et al. Journal of Materials Science Materials in Electronics, 2015 Bi3NbO7 (BNO) thin films were deposited on Pt/TiO2/SiO2/Si (100) substrates at room temperature from the polymeric precursor method. X-ray powder diffraction and transmission electron microscopy were used to investigate the formation characteristics and stability range of the tetragonal modification of a fluorite-type solid solution. The results showed that this tetragonal, commensurately modulated phase forms through the intermediate formation of the incommensurately modulated cubic fluorite phase followed by the incommensurate-commensurate transformation. The 200 nm thick BNO films exhibit crystalline structure, a dielectric constant of 170, capacitance density of 200 nF/cm2, dielectric loss of 0.4 % at 1 MHz, and a leakage current density of approximately 1 × 10−7 A/cm2 at 5 V. They show breakdown strength of about 0.25 MV/cm. The leakage mechanism of BNO film in high field conduction is well explained by the Schottky and Poole–Frenkel emission models. The 200 nm thick BNO film is suitable for embedded decoupling capacitor applications directly on a printed circuit board.
Evidence of magnetoelectric coupling on calcium doped bismuth ferrite thin films grown by chemical solution deposition L. V. Costa, M. G. Ranieri, M. Cilense, E. Longo, A. Z. Simões Journal of Applied Physics, 2014 Magnetoelectric coupling was observed at room temperature in calcium modified bismuth ferrite BiFeO3 (BFO) thin films deposited on Pt/TiO2/SiO2/Si (100) substrates by the chemical solution deposition. Undoped and Ca-doped BiFeO3 films were coherently grown at a temperature of 500 °C for 2 h. The highest doped BFO film has a tetragonal structure with P4mm space group, while BFO has a rhombohedral structure with space group R3c, which can be treated as a special triclinic structure. Room temperature magnetic coercive field indicates that the undoped film is magnetically soft with maximum magnetoelectric coefficient in the longitudinal direction was about 12 V/cm. Adding Ca2+ ions to BFO in high concentration decreases the remnant polarization and stabilizes the charged domain walls which interact with oxygen vacancies reducing coercive field.
Uso de agregados reciclados da construção civil na argamassa autoadensável FRS Valle, PC Gonçalves, MGA Ranieri, MLNM Melo, VC Santos Revista IBRACON de Estruturas e Materiais 15, e15107 , 2022 2022 Citations: 1
Analysis of the Scientific Production of Cementitious Composites with Recycled Polymeric Materials LR Roque-Silva, PM Alves, MHB Souza, GZ Costal, RM Martins, ... Recycling of Plastics, Metals, and Their Composites, 357-385 , 2021 2021
Cementitious Composites for Civil Construction Made with Marble and Granite Waste MGA Ranieri, P Capellato, MAB Martins, VC dos Santos, PC Gonçalves, ... Recycling of Plastics, Metals, and Their Composites, 387-408 , 2021 2021
Design e Materiais: Análise sociotécnica e aplicação de novo material com minimização de recursos em Conceição dos Ouros, MG BSM Domingos, MGA Ranieri, A da Silva Mello, ÉL Luciano, RB Ribeiro, ... Conjecturas 21 (6), 191-220 , 2021 2021
Physical and Chemical Properties ofWaste Foundry Exhaust Sand for Use in Self-Compacting Concrete MA de Barros Martins, LRR da Silva, MGA Ranieri, RM Barros, ... mdpi , 2021 2021 Citations: 25
Use of recycled aggregates from civil construction in self-compacting mortar FRS Valle, PC Gonçalves, MGA Ranieri, MLNM Melo, VC Santos Revista IBRACON de Estruturas e Materiais 15 (1), e15107 , 2021 2021 Citations: 7
Microstructural characterization of ceramic artifacts made using the raku technique WAM Júnior, MGA Ranieri, RB Ribeiro, JL Rosa, A da Silva Mello Research, Society and Development 10 (9), e6910917755-e6910917755 , 2021 2021 Citations: 1
Análise microbiológica da água fornecida a uma Unidade de Saúde no Município de Itajubá, Minas Gerais AC França, GP de Abreu, LF Balioni, P Capellato, MGA Ranieri, ... Research, Society and Development 10 (6), e33910615220-e33910615220 , 2021 2021
Low environmental impact construction: fragilities and potentialities of hyperadobe as a solution for the Brazilian housing deficit P Capellato REVES-Revista Relações Sociais , 2021 2021 Citations: 2
Resistive switching and multiferroic behavior of La0.5Pr0.5FeO3 ferrite thin films Ranieri, Ortega, Moreno, Ramirez, Aguiar, Simões 2021 Citations: 15
Optimization of anodization parameters in Ti-30Ta alloy P Capellato, D Sachs, LVB Vasconcelos, MM Melo, G Silva, MGA Ranieri, ... Metals 10 (8), 1059 , 2020 2020 Citations: 7
Avaliação da biocompatibilidade do polímero PCL recobrindo a liga Ti-30Ta P Capellato, G Silva, MGA Ranieri, MLNM Melo, SEA Camargo, ... Research, Society and Development 9 (8), e788985953-e788985953 , 2020 2020 Citations: 1
Método de ensino ativo utilizando avaliação por pares e autoavaliação P Capellato, LVB Vasconcelos, MGA Ranieri, D Sachs Research, Society and Development 9 (7), e21973495-e21973495 , 2020 2020 Citations: 15
Como escrever uma dissertação de mestrado MGA Ranieri, AC de Siqueira Ferreira, P Capellato, G Silva, LF Silva Research, Society and Development 9 (3), e149932584-e149932584 , 2020 2020 Citations: 3
How to write a master degree dissertation MGA Ranieri, AC de Siqueira Ferreira, P Capellato, G Silva, LF Silva Research, Society and Development 9 (3), 149932584 , 2020 2020
Peer and self-evaluation using active teaching method P Capellato, LVB Vasconcelos, MGA Ranieri, D Sachs Research, Society and Development 9 (7), e21973495 , 2020 2020 Citations: 5
Biocompatibility evaluation of the PCL polymer covering the Ti-30Ta alloy P Capellato, G Silva, MGA Ranieri, MLNM Melo, SEA Camargo, ... 2020
Possibilidade de utilizar resíduos de pneus inservíveis na composição de misturas para fabricação de blocos de cimento Possibility to use waste tire waste in the composition of … MGA Ranieri, MA de Barros Martins, P Capellato, MLNM Melo, ... Research, Society and Development 9 (9), e69996773 , 2020 2020
Possibility to use waste tire waste in the composition of mixtures for the manufacture of cement blocks MGA Ranieri THE RESEARCH, SOCIETY AND DEVELOPMENT Учредители: Federal University of … , 2020 2020 Citations: 2
La 0.5 Sm 0.5 FeO 3 : a new candidate for magneto-electric coupling at room temperature MGA Ranieri, M Cilense, EC Aguiar, AZ Simões, MA Ponce, E Longo Journal of Materials Science: Materials in Electronics 28 (14), 10747-10757 , 2017 2017 Citations: 2
MOST CITED SCHOLAR PUBLICATIONS
Gas sensor applications of zinc oxide thin film grown by the polymeric precursor method G Biasotto, MGA Ranieri, CR Foschini, AZ Simões, E Longo, MA Zaghete Ceramics International 40 (9), 14991-14996 , 2014 2014 Citations: 52
Syntheses of bismuth titanate templates obtained by the molten salt method MGA Ranieri, EC Aguiar, M Cilense, AZ Simões, JA Varela Ceramics International 39 (7), 7291-7296 , 2013 2013 Citations: 27
Physical and Chemical Properties ofWaste Foundry Exhaust Sand for Use in Self-Compacting Concrete MA de Barros Martins, LRR da Silva, MGA Ranieri, RM Barros, ... mdpi , 2021 2021 Citations: 25
Resistive switching and multiferroic behavior of La0.5Pr0.5FeO3 ferrite thin films Ranieri, Ortega, Moreno, Ramirez, Aguiar, Simões 2021 Citations: 15
Método de ensino ativo utilizando avaliação por pares e autoavaliação P Capellato, LVB Vasconcelos, MGA Ranieri, D Sachs Research, Society and Development 9 (7), e21973495-e21973495 , 2020 2020 Citations: 15
Magnetoelectricity at room temperature in the LaFeO 3 /BiFeO 3 heterostructures MG Ranieri, RAC Amoresi, MA Ramirez, JA Cortes, LSR Rocha, CC Silva, ... Journal of Materials Science: Materials in Electronics 27 (9), 9325-9334 , 2016 2016 Citations: 13
Electrical behavior of chemically grown lanthanum ferrite thin films MGA Ranieri, M Cilense, EC Aguiar, CC Silva, AZ Simões, E Longo Ceramics International 42 (2), 2234-2240 , 2016 2016 Citations: 13
Electrical behavior of Bi0. 95Nd0. 05FeO3 thin films grown by the soft chemical method FB Destro, F Moura, CR Foschini, MG Ranieri, E Longo, AZ Simões Ceramics International 40 (6), 8715-8722 , 2014 2014 Citations: 10
Evidence of magnetoelectric coupling on calcium doped bismuth ferrite thin films grown by chemical solution deposition LV Costa, MG Ranieri, M Cilense, E Longo, AZ Simões Journal of Applied Physics 115 (17) , 2014 2014 Citations: 9
Use of recycled aggregates from civil construction in self-compacting mortar FRS Valle, PC Gonçalves, MGA Ranieri, MLNM Melo, VC Santos Revista IBRACON de Estruturas e Materiais 15 (1), e15107 , 2021 2021 Citations: 7
Optimization of anodization parameters in Ti-30Ta alloy P Capellato, D Sachs, LVB Vasconcelos, MM Melo, G Silva, MGA Ranieri, ... Metals 10 (8), 1059 , 2020 2020 Citations: 7
Influence of processing route on electrical properties of Bi4Ti3O12 ceramics obtained by tape-casting technology MGA Ranieri, EC Aguiar, M Cilense, BD Stojanovic, AZ Simões, JA Varela Materials Research Bulletin 70, 20-25 , 2015 2015 Citations: 7
Caracterização tecnológica das argilas da cidade de cunha para fins de cerâmica artística MGA Ranieri Universidade Estadual Paulista (Unesp) , 2007 2007 Citations: 6
Estudo de argilas para uso em cerâmica vermelha A TANAKA, MGA RANIERI CONGRESSO BRASILEIRO DE ENGENHARIA E CIÊNCIA DOS MATERIAIS, 1-10 , 2006 2006 Citations: 6
Peer and self-evaluation using active teaching method P Capellato, LVB Vasconcelos, MGA Ranieri, D Sachs Research, Society and Development 9 (7), e21973495 , 2020 2020 Citations: 5
Avaliação da cobertura vegetal arbórea em Cachoeira do Sul/RS: índice e distribuição espacial do elemento verde na paisagem urbana D de Souza Lindenmaier, BS Penna Geografia Ensino & Pesquisa, 79-88 , 2015 2015 Citations: 4
Fabrication and structural characterization of bismuth niobate thin films grown by chemical solution deposition LF Goncalves, JA Cortés, MGA Ranieri, FB Destro, MA Ramirez, ... Journal of Materials Science: Materials in Electronics 26 (2), 1142-1150 , 2015 2015 Citations: 4
Como escrever uma dissertação de mestrado MGA Ranieri, AC de Siqueira Ferreira, P Capellato, G Silva, LF Silva Research, Society and Development 9 (3), e149932584-e149932584 , 2020 2020 Citations: 3
Low environmental impact construction: fragilities and potentialities of hyperadobe as a solution for the Brazilian housing deficit P Capellato REVES-Revista Relações Sociais , 2021 2021 Citations: 2
Possibility to use waste tire waste in the composition of mixtures for the manufacture of cement blocks MGA Ranieri THE RESEARCH, SOCIETY AND DEVELOPMENT Учредители: Federal University of … , 2020 2020 Citations: 2