Publicações - engenharias
|
Jeferson A Moreto;
Cléber Alexandre da Silva;
Jeferson A Moreto;
Castro, D.B.V;
Haroldo de Ara[ujo Ponte
Palavra-chave:
Sulphidation process;
protective film;
corrosion;
erosion - corrosion
Áreas do conhecimento:
Engenharias; Engenharia Elétrica; Telecomunicações;
Engenharias; Engenharia de Materiais e Metalúrgica; Metalurgia Física; Corrosão;
Engenharias; Engenharia de Materiais e Metalúrgica; Metalurgia Física
resumo ...
Abstract. This work presents a survey of the mechanical properties (hardness and modulus of elasticity), tribology (friction coefficient and wear rate), and metallography analysis of the ASTM A283 carbon steel subjected to the sulphidation process. The samples were submitted to the sulphidation process at an atmosphere with 0.2 % H2S (hydrogen sulphide) and 98.8 % H2 (hydrogen gas) for different time (5,10, 20, 60, and 120 min)at 300°C. After exposure to sulphidation environment the growth kinetics was analyzed. The results obtained with the sulphidation process indicate that the ASTM A283 carbon steel follows a parabolic law with a equilibrium constant in terms of pressure Kp = 1.47· × 10−12 g2 cm−4 s−1 for the material analyzed. The experimental results for the hardness and surface modulus of the samples show an increase in the values for the sulphide sample for 120 min.
|
|
Rafael J. N. Gomes;
Sergio Henke;
Ana Sofia Climaco Monteiro D'Oliveira
Palavra-chave:
Plasma Transferred Arc;
Hardfacing;
Co- alloys
resumo ...
Cobalt-based alloys are widely used as hardfacing materials when wear resistance is required at...
|
|
ROSAS, GRACITA B.;
Elizete Maria Lourenço;
Thelma Solange Piazza Fernandes
Palavra-chave:
Modelagem de redes no nível de subestação;
Fluxo de Potência Ótimo;
Ramos de Impedância Nula
Áreas do conhecimento:
Engenharias; Sistemas Elétricos de Potência; Transmissão da Energia Elétrica, Distribuição da Energia Elétrica
resumo ...
Este artigo propõe a extensão da formulação do problema de Fluxo de Potência Ótimo (FPO) com o...
|
|
Gracita Batista Rosas;
Thelma Solange Piazza Fernandes;
Elizete Maria Lourenço
Palavra-chave:
Fluxo de Potência Ótimo;
Ramos de Impedância Nula
Áreas do conhecimento:
Engenharias; Engenharia Elétrica; Telecomunicações
resumo ...
Este artigo propõe a extensão da formulação do problema de Fluxo de Potência Ótimo (FPO) com o...
|
|
Lucas Weihmann;
Daniel Martins;
LEANDRO DOS SANTOS COELHO
Palavra-chave:
Robótica;
robótica de manipuladores;
otimização
Áreas do conhecimento:
Engenharias; Inteligência Computacional;
Engenharias; Engenharia Mecânica; Robótica de Manipuladores
resumo ...
The global optimization problem is not easy to solve and is still an open challenge for researchers since an analytical optimal solution is difficult …
|
|
Felix Sharipov
Palavra-chave:
Internal flow;
mass flow rate;
Mixture;
Vacuum System
resumo ...
|
|
Marsil de Athayde Costa e Silva;
LEANDRO DOS SANTOS COELHO;
Luiz Lebensztajn
Palavra-chave:
Biogeografia;
otimização com múltiplos objetivos;
dispositivos eletromagnéticos
resumo ...
Biogeography is the science that studies the geographical distribution and the migration of species in an ecosystem. Biogeography-based optimization (BBO) is a recently developed global optimization algorithm as a generalization of biogeography to evolutionary algorithm and has shown its ability to solve complex optimization problems. BBO employs a migration operator to share information between the problem solutions. The problem solutions are identified as habitat, and the sharing of features is called migration. In this paper, a multiobjective BBO, combined with a predator-prey (PPBBO) approach, is proposed and validated in the constrained design of a brushless dc wheel motor. The results demonstrated that the proposed PPBBO approach converged to promising solutions in terms of quality and dominance when compared with the classical BBO in a multiobjective version.
|
|
Yandre Maldonado e Gomes da Costa;
Luiz Eduardo Soares de Oliveira;
Alessandro Koerich;
Fabien Gouyon;
Jefferson Martins
Palavra-chave:
Audio;
Aprendizagem Computacional;
classificação;
música
Áreas do conhecimento:
Ciências Exatas e da Terra; Ciência da Computação; Metodologia e Técnicas da Computação; Engenharia de Software;
Engenharias; Engenharia Elétrica; Telecomunicações
resumo ...
|
|
Eduardo M. Szesz;
G. B. de Souza;
Emanuel Santos Júnior;
Neide Kazue Kuromoto
Palavra-chave:
titanium;
Bioactivity;
anodic oxidation;
alkali treatment
Áreas do conhecimento:
Engenharias; Engenharia Elétrica; Telecomunicações;
Engenharias; Engenharia de Materiais e Metalúrgica; biomateriais metálicos
resumo ...
|
|
Sandro Froehner;
Karina Scurupa Machado;
Luiz Fernando Dombroski;
Nunes, Anderson Correa;
Kishi, Regina Tiemy;
Tobias Bernward Bleninger;
SÁNEZ, JUAN
Palavra-chave:
biofilmes;
Controle Ambiental;
Compostos policíclicos aromáticos;
indicadores geoquímicos
Áreas do conhecimento:
Engenharias; Engenharia Sanitária; Saneamento Ambiental; Qualidade do Ar, das Águas e do Solo
resumo ...
Hydrophobic organic compounds are common in the environment, especially in water bodies like rivers and lakes. Generally, due to their physico-chemical characteristics, mainly to hydrophobicity, these compounds are adsorbed by suspended material or other compartments which provide compatibility. Thus, compounds such as polycyclic aromatic hydrocarbons (PAHs) are rapidly adsorbed onto suspended material or even naturally occurring biofilms in water bodies. Biofilms can be defined as complex structures with cells and aggregates of cells. The extracellular polymers present empty spaces that can be filled by water. The biofilm is a sessile microbial community with several kinds of organisms such as bacteria, protozoa, fungi, algae, and extracellular polymeric substances, which may be found on almost any surface exposed to water. Here, biofilms were used to monitor the presence of PAHs in the Barigui River in Curitiba, Brazil. For the measurements and collection of representative microcoenoses, a biofilm sampling device was designed consisting of six glass plates installed in an open polyvinyl chloride pipe of 30 cm diameter and 60 cm length. The sampling device was exposed in the Barigui River for 2 weeks campaigns. The formed biofilm was treated and chemical analysis was performed for PAHs determination. The results showed that biofilms can trap most of the PAHs, especially those with high K ow values (octanol–water partition coefficient). Four campaigns were conducted. The total PAHs concentration ranged from 11,204.34 ± 560.12 to 45,846.90 ± 2,290.45 ng/g. According to the isomers ratio, the main source of PAHs in the first and second campaign was of pyrolytic origin, in other words, the PAHs were by-products from burning of light-refined oil products (gasoline and diesel oil). Meanwhile, the other campaigns revealed that the main source is of petrogenic origin. However, the possibility of both sources is not discarded considering the scenario studied and the records of sediments samples. Most of the investigations carried out focused on the loading of river sediments and suspended solids, but the biofilms might detect the amount that could be taken up by benthic organisms, for instance.
|
