The Journal of Engineering and Exact Sciences

MONITORING OF FLANK WEAR AND DAMAGE ON TURNING CUTTING TOOLS BY IMAGE PROCESSING

2020-06-19T09:51:42-03:00

The development of the tool wear monitoring system by machining processes has been well recognized in the machine industry mainly due to the growing demand for product quality and improved productivity. For this, artificial vision systems have been used as a measurement tool in various application areas. Thus, the objective was to develop a system automatic based in the image processing to identify and measure flank wear in machining tool. Image processing techniques, discriminant function, to identify insert breakage, and Hough Transform, to find the flank wear profile, achieved over accuracy. Consequently, 94.3% to identify between worn and broken insert and 0.04 mm mistake in measurement of flank wear width compared with microscope.

THEORETICAL AND INSILCO PHARMACOKINETIC INVESTIGATIONS ON SOME PHENYL PIPERIDINE DERIVATIVES AS NOVEL ANTIDEPRESSANT AGENTS

2020-06-17T17:28:02-03:00

A theoretical bioinformatic investigation was carried out on some Inhibitors of serotonin transporter (SERT) of Phenyl piperidine derivatives using Density Functional Theory (DFT/B₃LYP/6-31G*) at ground state with Spartan 14 V1.1.4 software in modeling the antipsychotic activity of the compounds. The molecular descriptors were computed using the PaDEL-Descriptor software 2.20 version. Penta-parametric Multi-linear regression models were developed using the MLR-GFA for selecting the most important descriptors. The statistical parameters for the best model are; R²_Train= 0.8572, R²_adj = 0.8274, R²_Test= 0.678, Q²_cv (LOO) = 0.7664, Ꭓ²= 0.0036, r²_m(LOO)= 0.694 and Delta r²_m(LOO)= 0.0051). Also, the estimated Chi-squared (Ꭓ²= 0.0036), Root-mean squared error (RMSE= 0.168) and and

STOCHASTIC MODELING OF LIVING/CONTROLLED COPOLYMERIZATIONS IN TUBULAR REACTORS WITH LATERAL FEED

2020-06-18T09:00:18-03:00

It is known the controlled microstructure polymers production increase in continuous reactors due to all industrial advantages that this type of operation presents. In this paper, the synthesis via Nitroxide-Mediated Polymerization (NMP) of copolymers based on styrene and methyl methacrylate accomplished in a tubular reactor with lateral feed is modeled by Kinect Monte Carlo (kMC). This reactional configuration aims the copolymers production with originals microstructure and applications. There were obtained all the microstructural properties distributions of the synthesized material at interest and the conversion values, Polydispersity Index (PDI) and chains average molar mass are compared to experimental data. The conversion presented minimum and maximum deviation in the module of 0.61 and -21.85%, respectively. For the PDI and the molar mass, there were obtained minimum and maximum errors of 0.72%, 1.50%, -23.10% and 1.77%, respectively. It was verified that the formed product differed from the expected one in experiments. There were found copolymers of polystyrene-b-poly(methyl styrene-rand-methacrylate), not being found any region that presented composition gradient through the chains, differently than it had been foreseen in the experimental synthesis, results that show the relevance of a stochastic simulation in the process to make decisions in the context of polymer reaction engineering.

PURIFICAÇÃO DO BIODIESEL DE ÓLEO DE SOJA POR MEIO DO EMPREGO DE LÍQUIDOS IÔNICOS ANÁLOGOS BASEADOS EM CLORETO DE COLINA

2020-06-17T17:28:05-03:00

Os processos tradicionais de purificação do biodiesel são onerosos e lentos, gerando grandes volumes de efluentes para atender os parâmetros de qualidade exigidos pela legislação. Este trabalho avalia os efeitos de novas combinações para a síntese de líquidos iônicos (LI’s) sobre a eficiência do solvente na remoção de impurezas do biodiesel de soja. Os LI’s análogos a base de cloreto de colina, sintetizados com a mistura eutética de glicerol, etilenoglicol e trietilenoglicol, foram usados para lavar o biodiesel pré-purificado em diferentes razões. O LI L9 composto por cloreto de colina, glicerol e trietilenoglicol (1:2:1), teve a maior eficiência (98,05%) quando usado na razão R2 (1:1), com um tempo ótimo de lavagem de 60 minutos. O biodiesel bruto também foi purificado com o novo solvente e apresentou uma boa eficiência mesmo quando reutilizado, em conformidade com a RANP 45/2014.

QUESTIONING THE RELEVANCE OF SOLUTION pH CALCULATION

2020-06-17T19:57:41-03:00

A brief discussion on the unnecessary calculation of pH in solution was done, as the historical reasons for this need before the invention of commercial pH meter was widely diffused. An alternative approach for acid-base equilibrium evaluation was proposed, without approximation or need of application only for simple solutions. The central aspect for the new approach is the determination of equilibrium concentration of all chemical species in solution, including the strong acid or base concentration for adjusting of pH of solutions. Therefore, the proposed method allowed the calculation in a mixture, including several polyprotic systems. Two detailed examples were presented. The effective electrical charge parameter was formally defined.

RESPONSE SURFACE METHODOLOGY AND DESIRABILITY FUNCTION AS STATISTICAL TOOLS IN THE OPTIMIZATION OF ELECTROCOAGULATION PROCESS IN SURFACE WATER

2020-06-17T17:27:55-03:00

The electrocoagulation for water clarification for purification have been studied as alternative to the processes of the water treatment. This study aimed to model and to optimize this process for types of water with different turbidity conditions; considering the current intensity, electrolysis time and initial pH on apparent color removal, chemical oxygen demand and surface water turbidity. Electrocoagulation tests were make aluminum electrodes. The optimal operating conditions and models based on the response surface methodology were obtained with central composite design. In order to comply with the esthetic / organoleptic standard stipulated for this stage of the process, the characterization of the three types of water studied must have color < 15 uH, COD < 18 mg L^-1 O₂ and turbidity < 5 NTU). The correlation between the analyzed answers allows finding specific conditions of the parameters, assisting in the determination of safe work points in the operation of clarification.

CRIAÇÃO DE BANCO DE DADOS PARA SIMULAÇÃO DA PRODUÇÃO DE BIODIESEL. PARTE 1: ESTIMATIVA DE PROPRIEDADES TERMOFÍSICAS DE ÓLEOS VEGETAIS

2020-06-23T12:05:58-03:00

Pesquisas com foco no desenvolvimento de processos de produção de biocombustíveis têm aumentado significativamente nos últimos anos, principalmente por questões ambientais e econômicas. A busca por matérias-primas de baixo custo, bem como o desenvolvimento de modelos de simulação capazes de prever as condições da produção e as propriedades dos componentes, podem ser o caminho para aumentar o desempenho desses processos. O conhecimento propriedades termofísicas dos componentes da alimentação é crucial para que os resultados sejam similares aos reais. Assim, o objetivo deste trabalho foi avaliar métodos de estimativas de propriedades termofísicas, a fim de desenvolver uma base de dados dos compostos dos óleos vegetais e recomendar os métodos adequados com base na precisão e consistência dos dados obtidos. Ao final deste trabalho recomendou-se o modelo mais viável para cada propriedade avaliada, comparando-se os valores estimados aos dados experimentais disponíveis na literatura.

CRIAÇÃO DE BANCO DE DADOS PARA SIMULAÇÃO DA PRODUÇÃO DE BIODIESEL. PARTE 2: ESTIMATIVA DE PROPRIEDADES TERMOFÍSICAS DO BIODIESEL

2020-06-23T12:06:53-03:00

O conhecimento adequado das propriedades físicas do biodiesel é necessário para simular e otimizar seu processo de obtenção, principalmente o reator químico. O objetivo deste trabalho foi avaliar modelos de predição de propriedades físicas de ésteres metílicos e etílicos que compõem o biodiesel para modelagem de um reator. Embora alguns dados experimentais estejam disponíveis, a determinação para todos os componentes existentes no biodiesel pode ter alto custo e ser uma tarefa complexa. Portanto, este trabalho investigou modelos de contribuição de grupos e abordagem por fragmentos no cálculo dessas propriedades. As propriedades avaliadas foram: temperatura normal de ebulição, temperatura crítica, pressão crítica, volume crítico, fator acêntrico, densidade, entalpia de vaporização, entalpia e energia de Gibbs de formação, viscosidade, número de cetano, propriedades de fluxo a frio e ponto de fulgor. Para cada propriedade avaliada, foi recomendado o modelo mais viável, comparando-se os valores estimados aos dados experimentais disponíveis na literatura. Assim, foi criado um banco de dados dessas propriedades para uso em aplicações de engenharia.

COMBINATORIAL TECHNIQUE FOR OPTIMIZING THE COMBINATION

2020-06-23T09:35:22-03:00

This paper presents an innovative computing method and models for optimizing the combination defined in combinatorics. The optimized combination has been derived from the iterative computation of multiple geometric series and summability by specialized approach. The optimized combinatorial technique has applications in science, engineering and management. In this paper, several properties and consequences on the innovative optimized combination has been introduced that are useful for scientific researchers who are solving scientific problems and meeting today’s challenges.

POSFUST RELIABILITY OF A NON-REPAIRABLE MULTI-STATE SYSTEM WITH POSFUST FAILURE RATE ESTIMATION

2020-08-04T15:25:20-03:00

Present research paper attempts to estimate the posfust reliability of a non-repairable multi-state system (NRMSS). Failure rate estimation is key factor in the reliability estimation. But due to uncertainty in the environment and probabilistic measure, the absolute measurement of the failure rate is quite tedious. In this research paper, we have introduced a new measure for failure rate estimation using possibilistic measure based on fuzzy logic. In this work for the effective measurements of reliability, we have tried to cover the uncertainty in the failure rate at every state failure level. In this research paper, we have taken a non-repairable three state system and failure rate transition of every state is taken in the form of upper and lower bound in possibilistic measure. In this approach, Markov process (multi-state system) is used for getting the governing differential equation for transition from one state to another state. Numerical computations are also being carried out to estimate the posfust reliability.