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Analysis of geometric variation of three degrees of freedom through the constructal design method for a oscillating water column device with double hidropneumatic chamber

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Defect and Diffusion Forum 2019年 396卷 22-31页

作者： Lima, Yuri T.B. Gomes, Mateus N. Cardozo, Camila F. Isoldi, Liércio A. Santos, Elizaldo D. Rocha, Luiz A.O. Universidade Federal Do Rio Grande Do sul - UFRGS Mechanical Engineering Post Graduation Program - PROMEC Rua Sarmento Leite 425 Porto Alegre RS Brazil Instituto Federal de Ciência e Tecnologia Do Paraná - IFPR Avenida Antônio Carlos Rodrigues 453 Paranaguá PR Brazil Universidade Do Vale Do Rio Dos Sinos - UNISINOS Mechanical Engineering Post Graduation Program Avenida Unisinos 950 São Leopoldo RS Brazil Universidade Federal Do Rio Grande - FURG Oceanic Engineering Pos Graduation Program Avenida Itália Km 8 Cp. 474 Rio Grande RS Brazil

This paper presents a biphasic two-dimensional numerical study of sea wave energy converters with operating principle being Oscillating Water Column (CAO) devices with two couples chambers. For the study of the geometric optimization, the Constructal Design method is applied in association with the exhaustive search method to determine the geometric arrangement that leads to the greatest hydropneumatic power available. The objective function is the maximization of hydropneumatic power converted by the device. The constraints of the problem are the inflow volumes of the hydropneumatic chamber (VE1, VE2), the total volumes (VT1, VT2) and the thicknesses of the device columns (e1, e3). The degrees of freedom analyzed were H1/L1 (ratio between height and length of the hydropneumatic chamber of the first device), H2/L2 (ratio between height and length of the hydropneumatic chamber of the second device), H2 (height of the column dividing the two devices) and e2 (thickness of the column dividing the devices). In the present work the degree of freedom H6 (depth of immersion of the device) is kept constant and equal to H6 = 9.86 m. The Finite Volume Method (FVM) was used in the numerical solution of the equations employed. For the treatment of the interaction between the air and water phases, the Volume of Fluid (VOF) method was applied. The results show that the maximum hydropneumatic power available was 5715.2 W obtained for degrees of freedom H1/L1 = H2/L2 = 0.2613 and e2 = 2.22 m. The case of lower performance has a power value equal to 4818.5 W with degrees of freedom equal to H1/L1 = H2/L2 = 0.2613 and e2 = 0.1 m. © 2019 Trans Tech Publications Ltd, Switzerland.

关键词： Design

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Effects of oxygen availability on Nb-Si multilayer processed by plasma transferred arc

Effects of oxygen availability on Nb-Si multilayer processed...

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Materials Science and Technology 2019, MS and T 2019

作者： Cardozo, Eloisa Pereira D'Oliveira, Ana Sofia C.M. Post Graduation Program on Materials Science and Engineering Universidade Federal do Paraná Curitiba Paraná Brazil Department of Mechanical Engineering Universidade Federal do Paraná Curitiba Paraná Brazil

ISBN: (纸本)0873397703

The need for higher propulsive and thermal efficiency in high temperature equipment has induced the search for materials that can withstand such harsh operating conditions. Within this group, the Nb-Si alloy system offers an attractive set of properties although they still present a challenge regarding the effects of oxygen. To address the role of processing environment on microstructure and oxidation performance of a Nb-Si multilayer, a powder mixture (Nb37wt%Si) were deposited under an argon atmosphere and in air. NbSi2 and Nb5Si3 were identified in multilayers processed with Nb37wt%Si mixture. The argon atmosphere accounts for changes in phase morphology and also for the enhanced oxidation resistance. This behavior can be accounted for by the high solubility of oxygen on silicides, that contributes to entrap oxygen in multilayers processed in air compromising oxidation performance. © 2019 MS&T19®

关键词： 3D printers

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Environmental Assessment of Used Lubricant Oil in Southern Brazilian Region

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环境核算与管理（英文） 2019年第4期7卷 381-394页

作者： Malaquias Zildo António Tsambe Cássio Florisbal de Almeida Cássia Maria Lie Ugaya Luiz Fernando de Abreu Cybis Institute of Hydraulic Research Post-Graduation Program in Hydric Resources and Environmental Sanitary Federal University of Rio Grande do Sul-Av.Bento Gon(c)alves 9500 Porto Alegre Brazil Federal University of Technology-Paraná Post-Graduation Program in Mechanical Engineering and Materials Av.Sete de Setembro Rebou(c)as-Curitiba 6681 Paraná Brazil

Brazil is currently the sixth world largest lubricating oil consumer,as a result,the sixth largest used lubricating oil (ULO) producer,with an annual ULO production of about one million ***,due to the environmental consequences and also to the large amount of this waste,it becomes necessary to quantify and qualify the impacts resulting from ULO management *** study evaluates,through the life cycle assessment (LCA) methodology,the current ULO management system in southern *** comparisons regarding the environmental performance scenarios were defined with the use of eight impact categories: land use,nonrenewable energy,global warming potential,aquatic acidification potential,aquatic eutrophication potential,human toxicity potential,terrestrial ecotoxicity potential and carcinogens *** LCA was conducted based on Simapro,using the "IMPACT 2002+ for ULO v2.12/IMPACT 2002+" *** scenarios comprised the two ULO management models currently used in *** first,which is designated in the study,by TTrR scenario and the second,regarded as TsTR *** LCA results showed that the re-refine phase,in the TsTR scenario,presents lower impact when compared to the corresponding TTR scenario *** TsTR scenario presented the greatest impacts in seven categories (carcinogens,terrestrial ecotoxicity,land use,eutrophication,global warming,use of nonrenewable energy and acidification),corresponding to about 87.5％ of all the *** the contrary,the TTR scenario presented lower impacts in these seven categories,impacting more on only one category (human toxicity).In relation to transportation,the opposite occurs,transport in the TTR scenario presents a larger contribution,impacting 100％ more than transport in the TsTR *** presence of the transshipment center decreases the amount of re-refining impacts in 87.5％ of the categories in the TTR *** in the TTR scenario contributes relatively more to the fact that

关键词： Life cycle assessment Used lubricant oil ULO management

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Prediction of Geometrical Characteristics and Process Parameter Optimization of Laser Deposition AISI 316 Steel Using Fuzzy Inference

Research Square

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Research Square 2021年

作者： Velázquez, Daniel René Tasé Helleno, André Luís Fals, Hipólito Carvajal dos Santos, Raphael Galdino Production Engineering Post-Graduation Program Methodist University of Piracicaba São Paulo Brazil Engineering School Mackenzie Presbyterian University São Paulo Brazil College of Mechanical and Industrial Engineering Oriente University Santiago de Cuba Cuba Federal Technological University of Paraná Paraná Brazil Insper - Institute for Education and Research São Paulo Brazil

Laser Metal Deposition (LMD) process is an additive manufacturing technique that has attracted the interest of the automotive and aerospace industries due to its ability to manufacture parts with complex geometries and different types of metallic materials. However, the structure of the deposited layers and the geometrical characteristics of the manufactured parts are influenced by the interaction among the deposition process parameters. In this paper, fuzzy inference (FIS) technique was used to develop two models for predicting the geometrical characteristics and, for optimizing the LMD process parameters using AISI 316 stainless steel powder and substrate. An experimental design, based on factorial analysis, was used to correlate the influence of selected deposition process parameters, laser power (Lp), powder flow (Pf) and focal length (Fl) with the process geometrical characteristics bead height (Bh), bead width (Bw), depth of penetration (Dp), dilution (d) and wetting angle (wa). The factors Lp and Fl were used with three operating levels each: Lp = 225 W, 250 W, 275 W, and Fl = 4.8 mm, 5.0 mm, 5.2 mm. The factor Pf was used with two levels, 9.40 g/s and 13.35 g/s. Analysis of variance allowed identifying that the Pf affect the Bh, Bh/Bw ratio, d and wa. The increase in Laser power (Lp) resulted in an increase of the geometric characteristics Bw and Dp. The first FIS, for predicting the bead’s geometrical characteristics, presented high adequacy (relative error up to 8.43 %) for assessing the experimental conditions. The second FIS indicated the best possible interaction, given the studied operating conditions and the variables evaluated. The maximum Output Defuzzified Index (ODI = 0.845) was obtained with the deposition process parameters Lp = 250 W, Fl = 5 mm, and Pf = 9.40 g/s. © 2021, CC BY.

关键词： Forecasting

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Corrigendum to “A new predictive model for a photovoltaic module’s surface temperature” [Energy Rep. 8 (2022) 15206–15220]

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Energy Reports 2024年 11卷 4522-4522页

作者： Domisley Dutra Silva Vinicius Marson Reinaldo Rodrigues de Souza Jeferson Diehl de Oliveira João Batista Campos Silva Elaine Maria Cardoso UNESP - São Paulo State University School of Engineering Post-Graduation Program in Mechanical Engineering Av. Brasil 56 Ilha Solteira SP 15385-000 Brazil Metrics Mechanical Engineering Department University of Minho Campus de Azurém Guimarães 4800-058 Portugal FSG - University Center Center of Innovation and Technology Department of Mechanical Engineering Os Dezoito do Forte 2366 Caxias do Sul RS 95020-472 Brazil UNESP - São Paulo State University School of Engineering São João da Boa Vista Brazil

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Erratum: Minimally Invasive Arthrodesis of the Equine Proximal Interphalangeal Joint: A Biomechanical Comparison of Three 5.5-mm Cortical Screws Inserted in Lag Fashion and Two 7.0-mm Headless Cannulated Dual-Pitch Compression Screws

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Veterinary and Comparative Orthopaedics and Traumatology 2024年第4期36卷 e1-e1页

作者： Aires Santana Rumpel Anderson Luiz De Carvalho Jakson Manfredini Vassoler Matheus Lothar Schmidt Cleiton Costa Mertz Cesar Augusto Camacho Rozo Joanna Kulczynski Campos Marcelo Meller Alievi Department of Animal Medicine Federal University of Rio Grande do Sul Porto Alegre RS Brazil Department of Mechanical Engineering Federal University of Rio Grande do Sul Porto Alegre RS Brazil Post-Graduation Program in Mining Metallurgical and Materials Engineering Federal University of Rio Grande do Sul Porto Alegre RS Brazil Universidad del Quindío Armenia Quindío Colombia

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An Innovative Elastomer Serpentine Heat Exchanger

SSRN

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SSRN 2023年

作者： de Souza, Reinaldo Rodrigues Sá Barbosa, Filipe M. Nobrega, Glauco Cardoso, Elaine Maria Teixeira, J.C.F. Moita, Ana Sofia Lima, R. Metrics Mechanical Engineering Department University of Minho Campus de Azurém Guimarães4800-058 Portugal IN+ Center for Innovation Technology and Policy Research Instituto Superior Técnico Universidade de Lisboa Av. Rovisco Pais Lisboa1049-001 Portugal UNESP - São Paulo State University School of Engineering Post-Graduation Program in Mechanical Engineering Av. Brasil 56 SP Ilha Solteira15385-000 Brazil UNESP - São Paulo State University Câmpus of São João da Boa Vista São João da Boa Vista Brazil CINAMIL—Centro de Investigação Desenvolvimento e Inovação da Academia Militar Academia Militar Instituto Universitário Militar Rua Gomes Freire Lisboa1169-203 Portugal R. Dr. Roberto Frias Porto4200-465 Portugal

This work aims to present the development stages of a serpentine heat exchanger, composed uniquely of a thin layer of a silicon-based organic elastomeric polymer, polydimethylsiloxane (PDMS). The novelty of this heat exchanger is that it allows the flowing liquid to wet the surface to be cooled directly, an innovation in relation to traditional exchangers, generally made up of tubes coupled to the heating surfaces. In order to evaluate its thermal performance, experimental flow tests compared two PDMS serpentines with a hydraulic diameter of around 5.0 mm with a traditional tubular copper serpentine. The heat exchanger made of PDMS was coupled to a steel plate that simulated the rear side of a photovoltaic thermal solar panel (PVT). In addition, different geometries were tested. Although PDMS is considered a material of low thermal conductivity, the experimental results showed a greater cooling capacity when compared to the traditional heat exchanger. Though the experimental results presented here were obtained for a specific case, the innovation can be used for thermal control of central process units (CPUs), smartphones, tablets, video games, and other mechanical and electronic devices with high cooling requirements © 2023, The Authors. All rights reserved.

关键词： Thermal conductivity

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Retraction notice to "Personal protective equipment-derived pollution during Covid-19 era: A critical review of ecotoxicology impacts, intervention strategies, and future challenges" [Sci. Total Environ. 887(2023) 164164]

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The Science of the total environment 2025年 967卷 178758页

作者： Mehedi Hasan Abu Reza Md Towfiqul Islam Most Mastura Munia Farjana Jion Md Naimur Rahman Susmita Datta Peu Arnob Das A B M Mainul Bari Md Saiful Islam Subodh Chandra Pal Aznarul Islam Tasrina Rabia Choudhury Md Refat Jahan Rakib Abubakr M Idris Guilherme Malafaia Department of Disaster Management Begum Rokeya University Rangpur 5400 Bangladesh. Department of Disaster Management Begum Rokeya University Rangpur 5400 Bangladesh Department of Development Studies Daffodil International University Dhaka 1216 Bangladesh. Department of Geography and Environmental Science Begum Rokeya University Rangpur 5400 Bangladesh. Department of Agriculture Hajee Mohammad Danesh Science and Technology University Dinajpur 5200 Bangladesh. Department of Mechanical Engineering Rajshahi University of Engineering & Technology 6 Rajshahi 6204 Bangladesh. Department of Industrial and Production Engineering Bangladesh University of Engineering and Technology Dhaka 1000 Bangladesh. Department of Soil Science Patuakhali Science and Technology University Dumki Patuakhali 8602 Bangladesh. Department of Geography The University of Burdwan Bardhaman 713104 West Bengal India. Department of Geography Aliah University 17 Gorachand Road Kolkata 700 014 West Bengal India. Analytical Chemistry Laboratory Chemistry Division Atomic Energy Centre Dhaka (AECD) Bangladesh Atomic Energy Commission Dhaka 1000 Bangladesh. Department of Fisheries and Marine Science Faculty of Science Noakhali Science and Technology University Noakhali Bangladesh. Department of Chemistry College of Science King Khalid University Abha 62529 Saudi Arabia Research Center for Advanced Materials Science (RCAMS) King Khalid University Abha Saudi Arabia. Post-Graduation Program in Conservation of Cerrado Natural Resources Goiano Federal Institute Urutaí GO Brazil Post-Graduation Program in Ecology Conservation and Biodiversity Federal University of Uberlândia Uberlândia MG Brazil Post-Graduation Program in Biotechnology and Biodiversity Federal University of Goiás Goiânia GO Brazil.

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Uncertainty evaluation on aperture area measurement for radiometric traceability 22

Uncertainty evaluation on aperture area measurement for radi...

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22nd World Congress of the International Measurement Confederation, IMEKO 2018

作者： Costa, P.B. Barros, W.S. Baldner, F.O. Department of Mechanical Engineering Federal University of Minas Gerais Campus Pampulha Av. Antonio Carlos 6627 Belo Horizonte/MG Brazil 50 Av. Nossa Senhora das Gracas Xerém Duque de Caxias/RJ Brazil Fluminense Federal University Post-Graduation Program on Mechanical Engineering-UFF-PGMEC 156 Rua Passo da Patria Niterói/RJ Brazil

In computer vision applications one of important step, when the aim of the system is to obtain a measurement result, is the uncertainty of measurement evaluation. Involving image processing and analysis for measurement requires a specific study of all input quantities and its contribution for expanded uncertainty. In this paper will be described all contributions and how each one affect the measurement result, including contributions from algorithms of image processing. Finally this work compares the uncertainty obtained with a previous result from Monte Carlo simulation for analysis validation. © 2018 Institute of Physics Publishing. All rights reserved.

关键词： Image processing

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Sequential deposition method of TiO2/CH3NH3PbI3 films for solar cell application

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IOP Conference Series: Materials Science and engineering 2019年第1期659卷

作者： A E R T P Oliveira F Bonatto A K Alves C Fragassa Post-Graduation Program in Mining Metallurgy and Materials Engineering (PPGE3M) Federal University of Rio Grande do Sul Osvaldo Aranha 99 90035-190 Porto Alegre Brazil InterDepartmental Centre for Industrial Research on Advanced Applications in Mechanical Engineering & Materials Technology Alma Mater Studiorum University of Bologna viale Risorgimento 2 40136 Bologna Italy

Seeking to study innovative solar cell compositions with the goal to reach the highest energy efficiency level attainable, the aim of this study was to develop a route to obtain a solar cell composed by hybrid perovskite (CH3NH3PbI3) using a sequential deposition method through the techniques of spin-coating and immersion. Initially, the deposition of PbI2 thin film of was performed on a FTO/glass substrate coated with TiO2, which was subsequently converted into perovskite crystals through spin coating using a CH3NH3I solution. The influence of the PbI2 layer thickness on the formation of CH3NH3PbI3 crystals was evaluated. The hydrophilic characteristic of TiO2 affects the distribution of the crystals nucleation sites, since PbI2 possesses a non-polar liquid characteristic. The characterization of the perovskite thin films showed that thickness affects directly the bandgap and the surface morphology, revealing the presence of dendritic structures and acicular crystals. Both growth and coverage increased for thinner layers of PbI2. It was also possible to observe an increased uniformity in the film for smaller PbI2 layers.

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