High-Speed Microprocessor-Based Optical Instrumentation for the Detection and Analysis of Hydrodynamic Cavitation Downstream of an Additively Manufactured Nozzle Luís Gustavo Macêdo West, André Jackson Ramos Simões, Leandro do Rozário Teixeira, Lucas Ramalho Oliveira, Juliane Grasiela de Carvalho Gomes, Igor Silva Moreira dos Anjos, Antonio Samuel Bacelar de Freitas Devesa, Leonardo Rafael Teixeira Cotrim Gomes, Lucas Gomes Pereira, Iran Eduardo Lima Neto, Júlio Cesar de Souza Inácio Gonçalves, Luiz Carlos Simões Soares Junior, Germano Pinto Guedes, Geydison Gonzaga Demetino, Marcus Vinícius Santos da Silva, Vitor Leão Filardi, Vitor Pinheiro Ferreira, André Luiz Andrade Simões, Luciano Matos Queiroz, Iuri Muniz Pepe Fluids, 2026 This study presents the development and validation of a high-speed optical data acquisition system for detecting and characterizing hydrodynamic cavitation downstream of a triangular nozzle. The system integrates a PIN photodiode, a transimpedance amplifier, and a high-sampling-rate microcontroller. Its performance was first evaluated using controlled sinusoidal signals, and statistical stability was assessed as a function of the number of acquired samples. Experiments were subsequently conducted in a converging–diverging conduit under biphasic flow conditions, where mean irradiance, standard deviation, and frequency spectra were analyzed downstream of the nozzle. The optical signal distributions revealed transitions in flow behavior associated with cavitation development, which were quantified through statistical metrics and spectral features. The Strouhal number was estimated from dominant frequencies extracted from the spectra, exhibiting a non-monotonic dependence on the Reynolds number, consistent with changes in flow structure and turbulence intensity. Spectral analysis further indicated frequency bands associated with energy transfer across turbulent scales and bubble dynamics. Overall, the results demonstrate that the proposed optical system constitutes a viable and non-intrusive methodology for detecting and characterizing cavitation intensity in a way that complements other optical and acoustic methods.
Experimental and Numerical Analysis of Nozzle-Induced Cavitating Jets: Optical Instrumentation, Pressure Fluctuations and Anisotropic Turbulence Modeling Luís Gustavo Macêdo West, André Jackson Ramos Simões, Leandro do Rozário Teixeira, Igor Silva Moreira dos Anjos, Antônio Samuel Bacelar de Freitas Devesa, Lucas Ramalho Oliveira, Juliane Grasiela de Carvalho Gomes, Leonardo Rafael Teixeira Cotrim Gomes, Lucas Gomes Pereira, Luiz Carlos Simões Soares Junior, Germano Pinto Guedes, Geydison Gonzaga Demetino, Marcus Vinícius Santos da Silva, Vitor Leão Filardi, Vitor Pinheiro Ferreira, André Luiz Andrade Simões, Luciano Matos Queiroz, Iuri Muniz Pepe Fluids, 2025 Cavitation has been widely explored to enhance physical and chemical processes across various applications. This study aimed to model the key characteristics of a cavitation jet, induced by a triangular-orifice nozzle, using both experimental and numerical methods. Optical instrumentation, a pressure transducer and the Reynolds-Averaged Navier–Stokes (RANS) equations were employed. Optical instrumentation and high-speed photography detected the two-phase flow generated by water vaporization, revealing a mean decay pattern. Irradiance fluctuations and photographic evidence provided results about the light transmission dynamics through cavitating jets. Pressure fluctuations exhibited similar growth and decay, supporting optical instrumentation as a viable method for assessing cavitation intensity. Experimental data showed a strong relationship between irradiance and flow rate (R2 = 0.998). This enabled the correlation of the standard deviation of instantaneous pressure measurements and normalized flow rate (R2 = 0.977). Furthermore, vapor volume fraction and normalized flow rate reached a correlation coefficient of 0.999. On the simulation side, the SSG-RSM turbulence mode showed better agreement with experimental data, with relative deviations ranging from 2.1% to 6.6%. The numerical results suggest that vapor jet length is related to vapor fraction through a power law, enabling the development of new equations. These results demonstrated that anisotropic turbulence modeling is essential to reproduce experimental observations compared to mean flow properties. Based on the agreement between the numerical model and the experimental data for mean flow quantities, a formulation is proposed to estimate the jet length originating from the nozzle, offering a predictive approach for cavitating jet behavior.
Magnetic properties of (Ni, Co)-doped tin oxide thin films Yuri Hamayano Lopes Ribeiro, Jime de Souza Sampaio, Vagner Oliveira Santos, Denis Gilbert Francis David, Marcus Vinicius Santos da Silva, Tenilson Souza da Silva, Tercio Neres dos Santos, Jailton Souza de Almeida Thin Solid Films, 2025
New dynamic test rig to study the influence of ultrasound on calcium carbonate scale formation Lucas R. Oliveira, Luiz C.S. Soares, Geydison G. Demetino, Lorena O.L. Soares, Juliane G.C. Gomes, Marcus V.S. da Silva, Vitor S. dos Santos, Leandro R. Teixeira, José M. de A. Santos, Vitor P. Ferreira, Iuri M. Pepe Results in Engineering, 2025 • Ultrasound reduces CaCO 3 scaling by altering nucleation and crystal growth. • Induction time analysis reveals significant acceleration under sonication. • CaCO 3 polymorphs shift from calcite to vaterite under ultrasonic treatment. • Ultrasound was able to reduce pressure drop and adhered mass on the rig. • Study provides a mechanistic understanding of ultrasound in scale control. Inorganic scale in oil and gas pipelines is a critical problem in the petrochemical industry, causing reduced flow in pipes and heat exchangers. Carbonates deposition is persistent and influenced by several factors such as temperature, pressure, and pH. This paper presents a Precipitation and Scaling Test Rig (PSTR) as an experimental platform to study the influence of ultrasound on calcium carbonate scale formation. This tool enables the investigation of the three main factors influencing inorganic scale formation (temperature, pressure, and pH) and allows experiments varying reagents flow rate, reagents concentration, and applying physical and chemical scale inhibitors during inorganic crystal formation reactions. To study the effects of ultrasound on calcium carbonate scale formation, two tests were performed: one without ultrasound irradiation and the other with ultrasound applied during the calcium carbonate crystallization process. In both cases, the same process parameters were used on the PSTR. The induction period was analyzed by measuring conductivity. The pressure drop across a deposition module was monitored. The results indicate that ultrasonic irradiation during crystallization accelerates crystal nucleation, prevents scale formation, and modifies the crystallographic phase of calcium carbonate crystals. Additionally, SEM images, composition, and phases of produced crystals showed changes in crystal morphology when ultrasound was applied.
Obtaining Microcellulose from Solid Agro-Waste by Ball Mill Assisted by Light Acid Hydrolysis Process Priscila S. Souza, Cristiani V. B. Grisi, Érica C. Monção, Marcus V. S. da Silva, Antonia L. de Souza ACS Omega, 2025 Cellulose, the most abundant biopolymer on Earth, is biodegradable, nontoxic, and derived from renewable sources. Its properties and applications depend on the extraction methods and sources, making plant waste reuse a sustainable production option. This study aimed to assess the potential of cowpea pod skin (Vigna unguiculata) as a source of microcellulose (CPMC) using a chemical-mechanical process involving ball milling combined with acid hydrolysis. For a comparative analysis of the method’s efficiency and biomass performance, corn straw (Zea mays L., CSMC) and pineapple peel (Ananas comosus, PPMC) were also utilized as extraction sources. The chemical composition of microcelluloses (MCs) was investigated by Fourier Transform Infrared Spectroscopy (FTIR), thermal behavior by Thermogravimetric Analysis (TGA), crystallinity by X-ray Diffraction (XRD), morphologies by Scanning Electron Microscopy (SEM), and shape and size by Atomic Force Microscopy (AFM). In the FTIR spectra, absorption bands characteristic of cellulose were observed at 3408 cm–1 (hydroxyl group OH stretching), 1640 cm–1 (adsorbed water molecules), 1205 cm–1 (O–H deformation vibration), 1165 cm–1 (C–O–C– stretching vibration), 1113 cm–1 (glucose ring stretching vibration), 1055 cm–1 (CO stretching), 1028 cm–1 (C–OH stretching), and 895 cm–1 (β-glycosidic bonds). The TGA/DTG curves of all the samples showed three stages of mass loss, and CPMC proved to be the sample with the greatest thermal stability. The crystallinity indices of the MCs samples ranged between 69.23–75%. The micrographs show compact and lamellar materials. However, AFM measurements revealed distinct nanostructures for each of the MCs obtained, displaying lamellar structures from 20 to 280 nm. Therefore, this method was efficient for extracting MCs from different types of biomass. The analyses demonstrated greater efficiency in the CPMC and CSMC samples. In this context, they have become promising candidates for application in a wide range of industrial materials.
Gelatin-Oxidized Alginate and Chitosan-Coated Zein Nanoparticle Hydrogel Composite to Enhance Breast Cancer Cytotoxicity in Dual-Drug Delivery Sanierlly da Paz Do Nascimento, Ramon Ramos Marques de Souza, Marianna Vieira Sobral, Francisco Humberto Xavier-Junior, Marcus Vinícius Santos da Silva, Marcelo Machado Viana, Fausthon Fred da Silva, Michael J. Serpe, Antonia L. de Souza ACS Omega, 2024 This study explores the combined delivery of doxorubicin and quercetin using a gelatin-oxidized alginate-based hydrogel as a promising strategy for localized breast cancer therapy. Our approach involves the incorporation of doxorubicin within the hydrogel matrix and loading quercetin into chitosan-coated zein nanoparticles. The hydrogel exhibited self-healing properties attributed to Schiff base cross-linking and demonstrated injectability. Characterization of its microstructural, mechanical, and textural properties revealed a porous and flexible structure, demonstrating its suitability for drug release applications. Both drugs exhibited distinct in vitro release profiles at pH 6.8 (typical of tumor tissue), with doxorubicin at 81.2% and quercetin at 9.7%. After 72 h of release, the cytotoxicity against MCF-7 breast cancer cells was assessed. The hydrogel formulation containing doxorubicin increased the cytotoxic action by 4.66-fold, whereas the hydrogel composite, containing both doxorubicin and quercetin-loaded nanoparticles, enhanced it by 20.7-fold compared with doxorubicin alone. Thus, the findings of our study highlight the enhancing effect of the dual release system, thereby expanding the utility of gelatin-oxidized alginate-based hydrogels as advanced drug delivery systems, as exemplified by the combined delivery of doxorubicin and quercetin.
Calcium carbonate scaling control on heat plate exchange surfaces using ultrasound Lucas Ramalho Oliveira, Lucas Gomes Pereira, Leandro do Rozário Teixeira, Marcus Vinícius Santos da Silva, Iuri Muniz Pepe, Vítor Pinheiro Ferreira, Luiz Carlos Simões Soares Junior, Geydison Gonzaga Demetino, Fabio Oliveira de Mattos, Andre Luiz Rufino Cordeiro, Carlos Eduardo Aguiar Lima Rodrigues, Rodrigo Pommerehn Vitiello Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2024
Composition, Structural and Optical Properties of Golden Grass Denis Gilbert Francis David, Pascal Bargiela, Marcus Vinicius Santos da Silva, Christian Godet, Victor Mancir da Silva Santana, Erick Rohan Santos Oliveira Magalhães, Leonis L. da Luz, Severino Alves Júnior, José Fernando Diniz Chubaci, Oswaldo Baffa, Antônio Ferreira da Silva Brazilian Journal of Physics, 2022
Properties of nitrogen-doped titanium oxides D.G.F. David, J. Guerreiro, M.V.S. da Silva, M.V. Castro Meira, P. Bargiela, J.S. de Almeida, J.A. Freitas, A. Ferreira da Silva Journal of Crystal Growth, 2012
