30 documents found, page 1 of 3
Thermal performance evaluation of pure PDMS and PDMS composites heat exchangers
Souza, Reinaldo; Nobrega, Glauco; Afonso, Inês Santos; Pereira, José; Cardoso, Elaine; Marques, Filipe; Vilarinho, Cândida; Moita, Ana; Lima, Rui A.This study investigates the heat transfer performance of three types of heat exchangers: one made of pure polydimethylsiloxane (PDMS), another incorporating recycled graphite (PDMS + Graphite 30 mass%), and a third using commercial aluminium nanoparticles (PDMS + Aluminium 30 mass%). Thermal performance was evaluated by measuring the thermal conductivity of the materials, analysing experimental convection tests...
Progress in Nanofluid Technology: From Conventional to Green Nanofluids for Bio...
Cardoso, Beatriz D.; Souza, Andrews; Nobrega, Glauco; Afonso, Inês Santos; Neves, Lucas Boniatti; Faria, Carlos; Ribeiro, J.E.; Lima, Rui A.Nanofluids (NFs), consisting of nanoparticles (NPs) suspended in base fluids, have attracted growing interest due to their superior physicochemical properties and multifunctional potential. In this review, conventional and green NF technology aspects, including synthesis routes, formulation, and applications, are discussed. Conventional NFs, involving NPs synthesized using physical and chemical approaches, have...
Green synthesis of copper ferrite-based nanofluids using Chlorella vulgaris for...
Cardoso, Beatriz; Nobrega, Glauco; Machado, Mariana; Lima, Rui A.This study investigates the green synthesis of copper ferrite nanoparticles (CuFe2O4 NPs) using an aqueous extract of Chlorella vulgaris as a reducing agent and their application in enhancing heat transfer through nanofluids. The successful formation of CuFe2O4 NPs was confirmed through UV–vis spectroscopy, revealing a progressive blue shift in absorption peaks from 380 nm to 350 nm over 4 h, accompanied by a r...
Sustainable green synthesis of metallic nanoparticle using plants and microorga...
Lima, Rui Alberto Madeira Macedo; Cardoso, Beatriz; Nobrega, Glauco; Afonso, Inês S.; Ribeiro, João E.Green synthesis provides a sustainable approach to producing metallic nanoparticles (MNPs) using biological entities such as plants, algae, bacteria, yeast, and fungi. While extensive research has explored these biosynthetic processes, an integrated review is needed to systematically consolidate knowledge on biosynthesis mechanisms, key synthesis parameters, and the comparative advantages and limitations of gre...
Progress in nanofluid technology: from conventional to green nanofluids for bio...
Cardoso, Beatriz Dias; Souza, Andrews Victor Almeida; Nobrega, Glauco; Afonso, Inês S.; Neves, Lucas Boniatti; Faria, Carlos; Ribeiro, JoãoNanofluids (NFs), consisting of nanoparticles (NPs) suspended in base fluids, have attracted growing interest due to their superior physicochemical properties and multifunctional potential. In this review, conventional and green NF technology aspects, including synthesis routes, formulation, and applications, are discussed. Conventional NFs, involving NPs synthesized using physical and chemical approaches, have...
Green synthesis of copper ferrite-based nanofluids using Chlorella vulgaris for...
Lima, Rui Alberto Madeira Macedo; Cardoso, Beatriz; Nobrega, Glauco; Machado, MarianaThis study investigates the green synthesis of copper ferrite nanoparticles (CuFe2O4 NPs) using an aqueous extract of Chlorella vulgaris as a reducing agent and their application in enhancing heat transfer through nanofluids. The successful formation of CuFe2O4 NPs was confirmed through UV–vis spectroscopy, revealing a progressive blue shift in absorption peaks from 380 nm to 350 nm over 4 h, accompanied by a r...
A review of methods to modify the PDMS surface wettability and their applications
Neves, Lucas B.; Afonso, Inês S.; Nobrega, Glauco; Barbosa, Luiz G.; Lima, Rui Alberto Madeira Macedo; Ribeiro, João E.Polydimethylsiloxane (PDMS) has attracted great attention in various fields due to its excellent properties, but its inherent hydrophobicity presents challenges in many applications that require controlled wettability. The purpose of this review is to provide a comprehensive overview of some key strategies for modifying the wettability of PDMS surfaces by providing the main traditional methods for this modifica...
Exploring heat exchange in space: recent advances in two-phase fluid experiment...
Nobrega, Glauco; Afonso, Inês Santos; Cardoso, Beatriz; Souza, Reinaldo Rodrigues de; Moita, Ana; Ribeiro, João EduardoThermal regulation has assumed a central role in space expeditions ever since the inception of Sputnik-1 in 1957. Throughout the years, numerous techniques have been developed to regulate temperatures in spacecraft and space habitats. Initially, passive systems like heat shields and thermal linings were employed, while newer missions embrace active cooling using fluids like ammonia and water. With significant a...
Recent advances of PDMS in vitro biomodels for flow visualizations and measurem...
Souza, Andrews; Nobrega, Glauco; Neves, Lucas B.; Barbosa, Filipe; Ribeiro, João; Ferrera, Conrado; Lima, Rui Alberto Madeira MacedoPolydimethylsiloxane (PDMS) has become a popular material in microfluidic and macroscale in vitro models due to its elastomeric properties and versatility. PDMS-based biomodels are widely used in blood flow studies, offering a platform for improving flow models and validating numerical simulations. This review highlights recent advances in bioflow studies conducted using both PDMS microfluidic devices and macro...
Experimental evaluation of green nanofluids in heat exchanger made oF PDMS
Nobrega, Glauco; Souza, Reinaldo Rodrigues; Cardoso, Beatriz; Afonso, Inês; Pereira, José; Cardoso, Elaine; Moita, Ana; Ribeiro, João; Lima, RuiConventional methods for synthesizing metallic nanoparticles face challenges such as instability and environ mental concerns. Therefore, new, simpler, and more eco-friendly methods are being explored. In this context, the study reports a green synthesis process to produce magnetic iron oxide nanoparticles using an aqueous extract of the alga Chlorella vulgaris. This process leverages natural resources to create...