Estudo experimental do escoamento bifásico líquido gás em golfadas com leve mudança de direção

Gas-liquid two-phase flow is very common in industrial applications, especially in the oil and gas, chemical, and nuclear industries. As operating conditions change such as the flow rates of the phases, the pipe diameter and physical properties of the fluids, different configurations called flow patterns take place. In the case of oil production, the most frequent pattern found is slug flow, in which continuous liquid plugs (liquid slugs) and gas-dominated regions (elongated bubbles) alternate. Offshore scenarios where the pipe lies onto the seabed with slight changes of direction are extremely common. With those scenarios and issues in mind, this work presents an experimental study of two-phase gas-liquid slug flows in a duct with a slight change of direction, represented by a horizontal section followed by a downward sloping pipe stretch. The experiments were carried out at NUEM (Núcleo de Escoamentos Multifásicos UTFPR). The flow initiated and developed under controlled conditions and their characteristic parameters were measured with resistive sensors installed at four pipe sections. Two high-speed cameras were also used. With the measured results, it was evaluated the influence of a slight direction change on the slug flow structures and on the transition between slug flow and stratified flow in the downward section.

Simulação numérica do escoamento monofásico em uma bomba centrífuga radial

Centrifugal pumps are vastly used in many industrial applications. Knowledge of how these components behave in several circumstances is crucial for the development of more efficient and, therefore, less expensive pumping installations. The combination of multiple impellers, vaned diffusers and a volute might introduce several complex flow characteristics that largely deviate from regular inviscid pump flow theory. Computational Fluid Dynamics can be very helpful to extract information about which physical phenomena are involved in such flows. In this sense, this work performs a numerical study of the flow in a two-stage centrifugal pump (Imbil ITAP 65-330/2) with a vaned diffuser and a volute. The flow in the pump is modeled using the software Ansys CFX, by means of a multi-block, transient rotor-stator technique, with structured grids for all pump parts. The simulations were performed using water and a mixture of water and glycerin as work fluids. Several viscosities were considered, in a range between 87 and 720 cP. Comparisons between experimental data obtained by Amaral (2007) and numerical head curves showed a good agreement, with an average deviation of 6.8% for water. The behavior of velocity, pressure and turbulence kinetic energy fields was evaluated for several operational conditions. In general, the results obtained by this work achieved the proposed goals and are a significant contribution to the understanding of the flow studied.

Validação numérica de leis coesivas triangulares para previsão de resistência de juntas adesivas em tração e corte puros

As ligações adesivas surgiram pela necessidade de se encontrar formas de unir componentes, por vezes de materiais distintos, através de técnicas mais vantajosas. Atualmente, qualquer estrutura deve ser resistente, robusta e leve, o que amplificou o interesse industrial e investigação nas ligações adesivas, principalmente na melhoria das propriedades de resistência e fratura de materiais. Desta forma, nos últimos anos, a utilização de juntas adesivas em aplicações industriais tem aumentando gradualmente, substituindo alguns métodos de ligação tradicionais, por apresentarem vantagens, tais como redução de concentração de tensões, reduzido peso e facilidade de processamento/fabrico. Em qualquer área da indústria, a aplicação em larga escala de uma determinada técnica de ligação supõe que estão disponíveis ferramentas confiáveis para o projeto e previsão da rotura. Neste âmbito, os Modelos de Dano Coesivo (MDC) são uma ferramenta fundamental, apesar de ser necessário estimar as leis coesivas do adesivo à tração e corte para entrada nos modelos numéricos. Nesta dissertação o trabalho experimental consistiu no tratamento de dados com vista à obtenção de GIc e GIIc, com a devida comparação de diferentes métodos de redução, bem como potencialidades e limitações dos mesmos. É realizada uma comparação dos três adesivos: Araldite® AV138, Araldite® 2015 e SikaForce® 7752. Neste trabalho estudou-se também numericamente a adequação de leis coesivas triangulares na previsão no comportamento de juntas adesivas, nomeadamente nas curvas forçadeslocamento (P-) de ensaios Double-Cantilever Beam para caracterização à tração e ensaios End-Notched Flexure para caraterização ao corte. Os ensaios foram simulados numericamente pelo software ABAQUS®, recorrendo ao Método de Elementos Finitos (MEF) e um MDC triangular, com o intuito de estimar a lei coesiva de cada um dos adesivos. Para os adesivos Araldite®AV138 e Araldite®2015, à tração e ao corte, a lei triangular previu o comportamento do adesivo com alguma razoabilidade. Para a previsão da resistência do adesivo SikaForce® 7752, a lei triangular não se ajustou convenientemente nem à tração nem ao corte. Considera-se que, para este adesivo, uma lei trapezoidal é a que melhor se adequa, devido à ductilidade do mesmo.

Influência da lubrirrefrigeração na qualidade superficial de metais retificados

Na fabricação de componentes mecânicos precisos, que necessitam de alta resistência mecânica e ao desgaste, utiliza-se o processo de retificação, para conferir o acabamento final desejado e, também, para eliminar as deformações ocorridas durante a têmpera do aço. No entanto, as condições de retificação devem ser adequadas, para que não sejam introduzidas falhas na peça. Novos conceitos de lubrificação e refrigeração, para o processo de retificação, estão sendo pesquisados, de forma a diminuir os custos e os danos ambientais causados pelos fluidos de corte. Nesse trabalho, é analisada a influência das técnicas de mínima quantidade de lubrificante (MQL), refrigeração otimizada e refrigeração convencional, com diferentes vazões e velocidade de aplicação do fluido de corte, na qualidade das peças produzidas com aço ABNT 4340 endurecido, no processo de retificação cilíndrica externa de mergulho com a utilização de rebolos de CBN. O Aço ABNT 4340 apresenta várias aplicações industriais, sendo considerado de uso aeronáutico devido, sua alta resistência mecânica sem aumentar o peso dos componentes que o utilizam. A análise da qualidade das peças foi realizada com a verficação das rugosidades e com a análise de microscopias eletrônicas de varredura. Verificou-se, ainda, a força tangencial de corte. em relação às diferentes formas de aplicação do fluido de corte, notou-se o melhor desempenho da aplicação otimizada, para maiores velocidades, mostrando a eficiência do bocal utilizado. O processo otimizado e o processo MQL foram capazes de manter a integridade superficial das peças produzidas. Exceção somente para a condição MQL com vazão de fluido de corte de 40ml/h, que produziu trincas e queima superficial. Rebolos com baixa concentração de CBN, conseqüentemente mais baratos, proporcionaram bons resultados, quando associados com técnicas mais eficientes de aplicação de fluido de corte apresentando desgaste reduzido.

Aplicação do método de Elementos Finitos eXtendido (MEFX) para a previsão da resistência de juntas adesivas de sobreposição dupla

As ligações adesivas têm sido utilizadas em diversas áreas de aplicação. A utilização das juntas adesivas em aplicações industriais tem vindo a aumentar nos últimos anos, por causa das vantagens significativas que apresentam comparativamente com os métodos tradicionais de ligação tais como soldadura, ligações aparafusadas e rebitadas. A redução de peso, redução de concentrações de tensões e facilidade de fabrico são algumas das principais vantagens das ligações adesivas. Devido à crescente utilização das ligações adesivas, torna-se necessário a existência de ferramentas que permitam prever a resistência das juntas com elevada precisão. Assim, para a análise de juntas adesivas, está a ser cada vez mais utilizado o método de Elementos Finitos. Neste âmbito o Método de Elementos Finitos eXtendido (MEFX) perfila-se como um método capaz de prever o comportamento da junta, embora este ainda não esteja convenientemente estudado no que diz respeito à aplicação a juntas adesivas. Neste trabalho é apresentado um estudo experimental e numérico pelo MEFX de juntas de sobreposição dupla, nas quais são aplicados adesivos que variam desde frágeis e rígidos, como o caso do Araldite® AV138, até adesivos mais dúcteis, como o Araldite® 2015 e o Sikaforce® 7888. Foram considerados substratos de alumínio (AW6082-T651) em juntas com diferentes comprimentos de sobreposição, sendo sujeitos a esforços de tração de forma a avaliar o seu desempenho. Na análise numérica foi realizada uma análise da distribuição de tensões na camada adesiva, a previsão da resistência das juntas pelo MEFX segundo critérios de iniciação de dano baseados em tensões e deformações, e ainda um estudo sobre o critério energético de propagação de dano. A análise por MEFX revelou que este método é bastante preciso quando usados os critérios de iniciação de dano MAXS e QUADS, e parâmetro com valor de 1 no critério energético de propagação de dano. Apesar de ser um método pouco estudado na literatura comparativamente com outros, o MEFX apresentou resultados muito satisfatórios.

Análise por meio de espectroscopia de emissão óptica das espécies ativas em nitretação iônica e gaiola catódica

Plasma process like ionic nitriding and cathodic cage plasma nitriding are utilized in order to become hard surface of steels. The ionic nitriding is already accepted in the industry while cathodic cage plasma nitriding process is in industrial implementation stage. Those process depend of plasma parameters like electronic and ionic temperature (Te, Ti), species density (ne, ni) and of distribution function of these species. In the present work, the plasma used to those two processes has been observed through Optical Emission Spectroscopy OES technique in order to identify presents species in the treatment ambient and relatively quantify them. So plasma of typical mixtures like N2 H2 has been monitored through in order to study evolution of those species during the process. Moreover, it has been realized a systematic study about leaks, also thought OES, that accomplish the evolution of contaminant species arising because there is flux of atmosphere to inside nitriding chamber and in what conditions the species are sufficiently reduced. Finally, to describe the physic mechanism that acts on both coating techniques ionic nitriding and cathodic cage plasma nitriding

Sintonia automática de controladores PID: uma abordagem neuro - genética

Dissertação de dout. em Electrónica e Computação, Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2004

Análise do desempenho de um queimador infravermelho funcionando com gás liquefeito de petróleo e glicerina

The use of infrared burners in industrial applications has many advantages in terms of technical-operational, for example, uniformity in the heat supply in the form of radiation and convection, with greater control of emissions due to the passage of exhaust gases through a macro-porous ceramic bed. This paper presents an infrared burner commercial, which was adapted an experimental ejector, capable of promoting a mixture of liquefied petroleum gas (LPG) and glycerin. By varying the percentage of dual-fuel, it was evaluated the performance of the infrared burner by performing an energy balance and atmospheric emissions. It was introduced a temperature controller with thermocouple modulating two-stage (low heat / high heat), using solenoid valves for each fuel. The infrared burner has been tested and tests by varying the amount of glycerin inserted by a gravity feed system. The method of thermodynamic analysis to estimate the load was used an aluminum plate located at the exit of combustion gases and the distribution of temperatures measured by a data acquisition system which recorded real-time measurements of the thermocouples attached. The burner had a stable combustion at levels of 15, 20 and 25% of adding glycerin in mass ratio of LPG gas, increasing the supply of heat to the plate. According to data obtained showed that there was an improvement in the efficiency of the 1st Law of infrared burner with increasing addition of glycerin. The emission levels of greenhouse gases produced by combustion (CO, NOx, SO2 and HC) met the environmental limits set by resolution No. 382/2006 of CONAMA

Análise de um queimador infravermelho funcionando com combustível híbrido : GLP/Bio-óleo

Biomass is considered the largest renewable energy source that can be used in an environmentally sustainable. From the pyrolysis of biomass is possible to obtain products with higher energy density and better use properties. The liquid resultant of this process is traditionally called bio-oil. The use of infrared burners in industrial applications has many advantages in terms of technical-operational, for example, uniformity in the heat supply in the form of radiation and convection, with a greater control of emissions due to the passage of exhaust gases through a macroporous ceramic bed. This paper presents a commercial infrared burner adapted with an ejector proposed able to burn a hybrid configuration of liquefied petroleum gas (LPG) and bio-oil diluted. The dilution of bio-oil with absolute ethanol aimed to decrease the viscosity of the fluid, and improving the stability and atomization. It was introduced a temperature controller with thermocouple modulating two stages (low heat / high heat), and solenoid valves for fuels supply. The infrared burner has been tested, being the diluted bio-oil atomized, and evaluated its performance by conducting energy balance. The method of thermodynamic analysis to estimate the load was used an aluminum plate located at the exit of combustion gases and the distribution of temperatures measured by thermocouples. The dilution reduced the viscosity of the bio-oil in 75.4% and increased by 11% the lower heating value (LHV) of the same, providing a stable combustion to the burner through the atomizing with compressed air and burns combined with LPG. Injecting the hybrid fuel there was increase in the heat transfer from the plate to the environment in 21.6% and gain useful benefit of 26.7%, due to the improved in the efficiency of the 1st Law of Thermodynamics of infrared burner

Aplicações de enzimas na síntese e na modificação de polímeros

Enzymes are biological catalysts that offer great potential for use in the synthesis and modification of polymers, being more specific and greener than chemical catalysts. In this work, enzymes from the classes of hydrolases (lipase, cutinase and protease) and of oxidoreductases (horseradish peroxidase, manganese peroxidase and laccase) were identified as the main biocatalysts responsible for the synthesis of polymers. Biocatalysis can potentially be part of the life cycle of several polymers, including polyesters, polyurethanes, polycarbonates, polyamides, functionalized polysaccharides and polystyrene, allowing the synthesis of specialty macromolecules for fine applications and with higher added-value than commodity polymers.

Origens e aplicações de recursos das companhias abertas industriais e comerciais no período 1980-1985

This research had for objective to fammi1iarize the user of accounting information to an efficient instrument in the modern financiaI ana1izes of eva1uation of entities: the Statement of Sources and App1ication of Resources. This statement goes on, ti11 today, to be 1ess used by the financiaI ana1ists because it is not understood concerning its objectives, concepts of Resources and shares of to bui1d and disc10sure the statement. During the period of time between 1980 and 1985 the Brazi1's economy spent of a situation of recession to another of prosperity and growth. In the first four years of the historiaI series, the country had a recession period and it was kept unti1 the end of 1983: the national private company increased its debt degree and decreased its 1iquidity. After 1984 the economy began to grow and that was pushed by the export entities: the entities decreased its debt degree and increased its 1iquidity. The Statement of Sources and Uses of Resources has been bui1t and pub1ished in United States since the 1ast 50 years of nineteenth century, and it has been known as Statement of Funds. In Brazi1 it has just introducted after the Security Exchange Law in 1976 that put 1imits for obrigatority to disc10sure by the companies. This 1aw described, summari1y, the objective, cQII1position and manner to disc1osure. The ma in objective of the statement is to show the financiaI position of the entity. This objective envolves aspects relationed to the long-term's strategy of the company because it disclosure the policy of application of resources in long-term assets, the policy of dividends that has been used, and the structure of resources provided by long-t:erm financing, the resources of the operations, and so on. There are several means of Resources. The concept more used in Brazil is Working Capital, till for orientation of the law. Concepts as Cash and Equivalent-Cash and Net Realizable Assets can be more informatives to the users because they show informations with better complexity, including informations concerning to the short-term. Concerning to the building methods, there are three that are known: the Transations Analizing method, the T-Account method and the Work-Sheet method. AlI of them are efficient, but it's recomendable that the method used can be in accordance with the disclosured formato The statement, despite of others statements, fell \

Atividade β-D-N-Acetilglucosaminidásica de enzimas imobilizadas extraídas da Artemia franciscana e possíveis aplicações biotecnológicas

A β-D-N-acetilglucosaminidase extracted and partially isolated from crustacean Artemia franciscana by ammonium sulfate precipitation and filtration gel chromatography Bio Gel A 1.5m. the enzyme was immobilized on ferromagnetic Dacron yielding a insoluble active derivative with 5.0 units/mg protein and 10.35% of the soluble enzyme activity. β-D-N-acetilglucosaminidase-ferromagnetic Dacron was easily removed from the reaction mixture by a magnetic field, it was reused for ten times without loss in its activity. The ferromagnetic Dacron was better activated at pH 5.0. The particles visualized at scanning electron microscope (SEM) had presented different sizes, varying between 721nm and 100µm. Infra red confirmed immobilization on support, as showed by primary amino peaks at 1640 and 1560 cm-1 . The immobilize enzyme presented Km of 2.32 ± 0.48 mM and optimum temperature of 50°C. Bought presented the same thermal stable of the soluble enzyme and larger enzymatic activity at pH 5.5. β-D-N-acetilglucosaminidase-Dacron ferromagnético showed sensible for some íons as the silver (AgNO3), with loss of activity. The β-D-N acetilglucosaminidase activity for mercury chloride (HgCl2), whom is one of the most toxic substance joined in nature, it was presented activity already diminished at 0,01mM and lost total activity at 4mM, indicating sensitivity for this type of metal. β-D-N-acetilglucosaminidase-ferromagnetic Dacron showed degradative capacity on heparan sulfate, the enzyme still demonstrated degradative capacity on heparan sulphate, suggesting a possible application to produce fractions of this glycosaminoglycan

Ambiente para desenvolvimento de aplicações fuzzy industriais

This paper describes the design, implementation and enforcement of a system for industrial process control based on fuzzy logic and developed using Java, with support for industrial communication protocol through the OPC (Ole for Process Control). Besides the java framework, the software is completely independent from other platforms. It provides friendly and functional tools for modeling, construction and editing of complex fuzzy inference systems, and uses these logical systems in control of a wide variety of industrial processes. The main requirements of the developed system should be flexibility, robustness, reliability and ease of expansion

Produção e avaliação das aplicações de enzimas quitinolíticas e queratinolíticas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Proteção de sistemas eletricos industriais: relés e suas aplicações em subestações

Electrical installations in industries involving high currents and voltages considered. On the other side is the common appearance of electrical failures, caused by human error, defects in electrical equipment or electrical installation aging itself. These failures are varied, those with the highest rate of occurrence and cause much damage to electrical installations, are overcurrent and overvoltage. Therefore there is a need to project a system that can detect and minimize possible effects caused by faults in electrical installations industries. Protection systems in electric industries emerge as an alternative to control especially voltage and current magnitudes. Engineered based on the functions of the relays, protection systems are an indispensable tool for any industrial substation. But the project of such systems becomes increasingly more complex, due to technological development. Electrical equipment not develop at the same speed that the protective devices (relays), making it indispensable knowledge of integration of technologies