Reconfiguração dinâmica de estratégias distribuídas em dispositivos foundation fieldbus para a otimização de processos na indústria do petróleo

The petrochemical industry has as objective obtain, from crude oil, some products with a higher commercial value and a bigger industrial utility for energy purposes. These industrial processes are complex, commonly operating with large production volume and in restricted operation conditions. The operation control in optimized and stable conditions is important to keep obtained products quality and the industrial plant safety. Currently, industrial network has been attained evidence when there is a need to make the process control in a distributed way. The Foundation Fieldbus protocol for industrial network, for its interoperability feature and its user interface organized in simple configuration blocks, has great notoriety among industrial automation network group. This present work puts together some benefits brought by industrial network technology to petrochemical industrial processes inherent complexity. For this, a dynamic reconfiguration system for intelligent strategies (artificial neural networks, for example) based on the protocol user application layer is proposed which might allow different applications use in a particular process, without operators intervention and with necessary guarantees for the proper plant functioning

Estimação e compensação de não linearidades inerentes aos atuadores dos processos industriais

The oscillations presents in control loops can cause damages in petrochemical industry. Canceling, or even preventing such oscillations, would save up to large amount of dollars. Studies have identified that one of the causes of these oscillations are the nonlinearities present on industrial process actuators. This study has the objective to develop a methodology for removal of the harmful effects of nonlinearities. Will be proposed an parameter estimation method to Hammerstein model, whose nonlinearity is represented by dead-zone or backlash. The estimated parameters will be used to construct inverse models of compensation. A simulated level system was used as a test platform. The valve that controls inflow has a nonlinearity. Results and describing function analysis show an improvement on system response

Potencial larvicida de extratos de plantas regionais no controle de larvas de Aedes aegypti

Dengue, amongst the virus illnesses one can get by vectorial transmission, is the one that causes more impact in the morbidity and mortality of world s population. The resistance to the insecticides has caused difficulties to control of vector insect (Aedes aegypti) and has stimulated a search for vegetables with larvicidal activity. The biodiversity of Caatinga is barely known and it is potential of use even less. Some plants of this biome are commercialized in free fairs northeast of Brazil, because of its phytotherapics properties. The vegetables in this study had been selected by means of a questionnaire applied between grass salesmen and natives of the Serido region from Rio Grande do Norte state; culicids eggs had been acquired with traps and placed in container with water for the larva birth. Thirty larvae had been used in each group (a group control and five experimental groups), with four repetitions four times. The vegetables had been submitted to the processes of decoction, infusion and maceration in the standard concentration of 100g of the vegetable of study in 1l of H2O and analyzed after ½, 1, 2, 4, 8, 12, 24 and 48 hours for verification of the average lethal dose (LD50) from the groups with thirty larva. The LD50 was analyzed in different concentrations (50g/l, 100g/l, 150g/l, 200g/l e 300g/l) of Aspidosperma pyrifolium Mart. 48 extracts of rind, leaf and stem of the seven vegetal species: Aspidosperma pyrifolium Mart., Mimosa verrucosa Benth, Mimosa hostilis (Mart.) Benth., Myracrodruon urundeuva Allemão, Ximenia americana L, Bumelia sartorum Mart Zizyphus joazeiro Mart, had been analyzed. The extracts proceeding from the three methods were submitted to the freezedrying, to evaluate and to quantify substances extracted in each process. The results had shown that Aspidosperma pyrifolium Mart. and Myracrodruon urundeuva Allemão are the species that are more distinguished as larvicidal after 24 hours of experiment, in all used processes of extraction in the assays. The Zizyphus joazeiro Mart species has not shown larvicidal activity in none of the assays. In relation to the extraction method, the decoction was the most efficient method in the mortality tax of the A. aegypti larvae

Do controle de constitucionalidade dos atos jurisdicionais transitados em julgado

The following study aims to verify in which hypothesis res judicata, when it comes of an unconstitutional decision, shall not prevail over Constitution. It displayed the characteristics of formal and material constitutional systems. It debated the concepts of existence, validity and efficacy of juridical rules and acts. It dissertated about the idea of Constitution s superiority and about the birth of the judicial review of constitutionality. It focused some contemporary models of this judicial review and its historical evolution in Brazil, showing its effects towards the current Constitution. It sustained that the decision given by Supremo Tribunal Federal during abstract control of rules must bind even legislative bodies, preventing them to produce the same rules previously declared unconstitutional. It held up that all parts of the decision of Supremo Tribunal Federal oblige, even the juridical arguments employed, in both diffused and concentrated reviews. It showed that, despite these models of review live together in Brazil, our constitutional system preferred the concentrated one, considering one only court over the other constitutional organs. It discussed about res judicata with the purpose of clarifying its juridical nature, its objective and subjective limits and its regulation in collective demands. It explained that the material res judicata is an effect of a decision which cannot be reviewed, which makes the law s will free of discussion, binding the contendants and avoiding that other courts, judging future demands about the same object, may decide differently. It showed how the regulation of res judicata in collective demands, in respect oh their subjective limits, is useful to demonstrate that it is not the material law who must adapt itself to res judicata as traditionally thought, but res judicata, as a warranty of juridical certainty and security, who must be shaped from the debated rule. It presented to view the main doctrinal conceptions about res judicata s review in the hypothesis of unconstitutional judgement. It concluded that the decisions forged by unconstitutional rules or interpretations reputed not compatible to the Constitution by Supremo Tribunal Federal, in spite of it can make res judicata, may be reviewed beyond the term to file a recissory claim, since while the debated law is still valid, no matter if its decision was before or after the res judicata. At the end, it asserted that, when it is not legally authorized, the judicial review of res judicata is not admissible, after the term to file a recissory claim, under the argument that there was no direct violation to the constitutional principle or rule

A Livre expressão na alfabetização de jovens e adultos: vivências em salas de aula

Cette étude a été faite à partir d une expérience d alphabétisation chez des jeunes et des adultes dans deux groupes du "Projet Réduction de l analphabétisme" realisé par l Université Fédérale du Rio Grande do Norte, le bureau du Ministere de l Éducation et la Préfecture Municipale de Natal-RN. Nous avons choisi la méthode qualitative de recherche, en utilisant l observation de la dynamique en salle de classe, considérant les acteurs sociaux comme étant le sujet actif du processus historique, culturel et politique. Nous avons voulu colaborer dans ce theme en proposant un référenciel théorique et pratique, en visant le dynamisme de la salle de classe, à travers la vision de I alphabétisation centrée sur les utilisations sociales de la lecture et de l écrit; la conception dialogique de Paulo Freire, basée sur la propre culture de l élève et sur sa valorisation en tant que sujet actif de l apprentissage ; la proposition pédagogique de Célestin Freinet dans son aspect de la dynamisation de la salle de classe renforçant le principe de la libre expression, de la colaboration, de l activité et le respect du rytme individuel, pour le succes scolaire. Nous avons rappelé que Célestin Freinet e Paulo Freire ont contribué dans la conscientisation individuelle, sociale, culturelle, politique, de l éleve par le processus scolaire. Nous avons séparé l intérêt et la participation de celles qui alphabétisent et des élêves dans ce processus éducatif. Nous avons constaté tout au long du travail des changements dans la posture de celles qui alphabétisent, surpassant les pratiques centrées dans le formalisme, et le verbalisme fruits de l Éducation traditionnelle. A vançant dans le sens de l Abordage Constructiviste de la connaissance, garantissant un climat de sécurité, de dynamisme et de respect en salle de classe

Educação inclusiva e formação continuada: contribuições dos casos de ensino para os processos de aprendizagem e desenvolvimento profissional de professores

This study focuses on processes of learning and professional development experienced by elementary school teachers who have students with special educational needs in their classrooms. Cases and case methods can be used as methodological resource to articulate the continued training of teachers in an inclusive perspective. This research-intervention adopted a constructive-collaborative model for continued teachers formation. The main objective was to investigate the possible contributions of teaching cases, while investigative and formative strategies, for the processes of learning and professional development of teachers who work in the regular school. The data were collected by means of analytical activities, drafting collective discussion and teaching cases, having eight teachers as participants in a regular public school, located in the municipality of Natal/RN, Brasil. The theoretical reference covers the inclusive education, teaching learning, teachers professional development, the knowledge base for teaching and teaching cases as a resource for continued teachers formation in an inclusive perspective. The results indicated that teaching cases allowed description and analysis of educational practices developed by regular education teachers and adoption of reflective processes about situations reported and on their own pedagogical actuation, achieving indications of changes. It also indicates the contribution of cases for the clarification, systematization and extension of professional knowledge about inclusive education process as well as for involvement by the teachers of the study in a pedagogical thinking process. The lessons learned are related mainly to own role as teachers of regular education, to the role of professional support and specialized institutions faced to school inclusion. The analyses showed the methodological option was suitable to develop a schoolcentric training process, allowing teachers to seek in their actual environment alternatives for construction of a new logic of teaching that encloses diversity. The conclusion is that the cases, while bringing educational situations closer to the reality experienced by teachers in their daily professional role, causes relevant improvement on teachers education, because it offers training in conjunction with the experience and knowledge that teachers already have

Educação inclusiva e formação continuada: contribuições dos casos de ensino para os processos de aprendizagem e desenvolvimento profissional de professores

This study focuses on processes of learning and professional development experienced by elementary school teachers who have students with special educational needs in their classrooms. Cases and case methods can be used as methodological resource to articulate the continued training of teachers in an inclusive perspective. This research-intervention adopted a constructive-collaborative model for continued teachers formation. The main objective was to investigate the possible contributions of teaching cases, while investigative and formative strategies, for the processes of learning and professional development of teachers who work in the regular school. The data were collected by means of analytical activities, drafting collective discussion and teaching cases, having eight teachers as participants in a regular public school, located in the municipality of Natal/RN, Brasil. The theoretical reference covers the inclusive education, teaching learning, teachers professional development, the knowledge base for teaching and teaching cases as a resource for continued teachers formation in an inclusive perspective. The results indicated that teaching cases allowed description and analysis of educational practices developed by regular education teachers and adoption of reflective processes about situations reported and on their own pedagogical actuation, achieving indications of changes. It also indicates the contribution of cases for the clarification, systematization and extension of professional knowledge about inclusive education process as well as for involvement by the teachers of the study in a pedagogical thinking process. The lessons learned are related mainly to own role as teachers of regular education, to the role of professional support and specialized institutions faced to school inclusion. The analyses showed the methodological option was suitable to develop a schoolcentric training process, allowing teachers to seek in their actual environment alternatives for construction of a new logic of teaching that encloses diversity. The conclusion is that the cases, while bringing educational situations closer to the reality experienced by teachers in their daily professional role, causes relevant improvement on teachers education, because it offers training in conjunction with the experience and knowledge that teachers already have

Avaliação do uso do DCP em areias para controle da capacidade de carga em fundações diretas e controle de compactação de aterros

This work presents results of field and laboratory tests using a Dynamic Cone Penetrometer, DCP. The tests were performed in order to evaluate the use of the equipment in sand for the control of bearing capacity of shallow foundations and fill compaction. For shallow foundations, the laboratory tests were conducted on sand placed in a metallic mould by the method of sand pluviation. Although the results show the inability to reproduce field conditions in the laboratory it was possible to verify the ability of the DCP to identify less resistant soil layers. The DCP tests for the analysis of compaction control were performed in a strong box with inside dimensions of 1,40 m x 1,40 m and 0,70 m in height. The soil layers were compacted with different densities though the use of a vibrating plate in order to obtain correlations between penetration index, DPI, and soil relative density. Other tests were also conducted to assess the influence of soil moisture on tests results. Among other findings, the results showed the great potential for the use of DCP to control the compaction of sand fills

Desenvolvimento de um sistema de planejamento, gestão de serviços e controle de custos em obras de construção civil

The increasing competitiveness of the construction industry, set in an economic environment in which the offer is now greater than the demand , causes the prices of many products and services, are strongly influenced by the processes of production and the final consumer. Thus, to become more competitive in the market and construction companies are seeking new alternatives to reduce and control costs, production processes and tools that allow for close monitoring of the construction schedule, with the consequent compliance deadline with the client. Based on this scenario, the creation of control tools, service management and planning work emerges as an investment opportunity and an area that can promote great benefits to construction companies. The goal of this work is to present a system of planning, service management and costs control that through worksheets provide information relating to the production phase of the work, allowing the visualization of possible irregularities in the planning and cost of the enterprise, enabling the company to take steps to achieve the goals of the enterprise in question, and correct them when necessary. The developed system has been used in a piece of real estate in Rio Grande do Norte, and the results showed that its use together allowed the construction company to accompany their results and take corrective and preventive actions during the production process, efficiently and effective

Controle on-line por atributos para o número de não-conformidades no item inspecionado com base em uma sequência de inspeção

This paper proposes a procedure to control on-line processes for attributes, using an Shewhart control chart with two control limits (warning limit and control limit) and will be based on a sequence of inspection (h). The inspection procedure is based on Taguchi et al. (1989), in which to inspect the item, if the number of non-conformities is higher than an upper control limit, the process needs to be stopped and some adjustment is required; and, if the last inspection h, from all items inspected present a number of non-conformities between the control limit and warning limit. The items inspected will suffer destructive inspection, being discarded after inspection. Properties of an ergodic Markov chain are used to get the expression of average cost per item and the aim was the determination of four optimized parameters: the sampling interval of the inspections (m); the constant W to draw the warning limit (W); the constant C to draw the control limit (C), where W £ C, and the length of sequence of inspections (h). Numerical examples illustrate the proposed procedure

Controle adaptativo robusto para um modelo desacoplado de um robô móvel

This thesis presents a new structure of robust adaptive controller applied to mobile robots (surface mobile robot) with nonholonomic constraints. It acts in the dynamics and kinematics of the robot, and it is split in two distinct parts. The first part controls the robot dynamics, using variable structure model reference adaptive controllers. The second part controls the robot kinematics, using a position controller, whose objective is to make the robot to reach any point in the cartesian plan. The kinematic controller is based only on information about the robot configuration. A decoupling method is adopted to transform the linear model of the mobile robot, a multiple-input multiple-output system, into two decoupled single-input single-output systems, thus reducing the complexity of designing the controller for the mobile robot. After that, a variable structure model reference adaptive controller is applied to each one of the resulting systems. One of such controllers will be responsible for the robot position and the other for the leading angle, using reference signals generated by the position controller. To validate the proposed structure, some simulated and experimental results using differential drive mobile robots of a robot soccer kit are presented. The simulator uses the main characteristics of real physical system as noise and non-linearities such as deadzone and saturation. The experimental results were obtained through an C++ program applied to the robot soccer kit of Microrobot team at the LACI/UFRN. The simulated and experimental results are presented and discussed at the end of the text

Sistema web didático para a supervisão de redes fieldbus

Technological evolution of industrial automation systems has been guided by the dillema between flexibilization and confiability on the integration between devices and control supervisory systems. However, there are few supervisory systems whose attributions can also comprehend the teaching of the communication process that happens behind this technological integration, where those which are available are little flexible about accessibility and reach of patterns. On this context, we present the first module of a didactic supervisory system, accessible through Web, applied on the teaching of the main fieldbus protocols. The application owns a module that automatically discovers the network topology being used and allows students and professionals of automation to obtain a more practical knowledgment by exchanging messages with a PLC, allowing those who are involved to know with more details the communication process of an automation supervisory system. By the fact of being available through Web, the system will allow a remote access to the PLC, comprehending a larger number of users. This first module is focused on the Modbus protocol (TCP and RTU/ASCII)

Ambiente de simulação híbrido integrando hysys e rede industrial Foundation Fieldbus aplicado ao controle de uma coluna de destilação

The main purpose of this work is to develop an environment that allows HYSYS R chemical process simulator communication with sensors and actuators from a Foundation Fieldbus industrial network. The environment is considered a hybrid resource since it has a real portion (industrial network) and a simulated one (process) with all measurement and control signals also real. It is possible to reproduce different industrial process dynamics without being required any physical network modification, enabling simulation of some situations that exist in a real industrial environment. This feature testifies the environment flexibility. In this work, a distillation column is simulated through HYSYS R with all its variables measured and controlled by Foundation Fieldbus devices

Uma arquitetura para sistemas supervisórios industriais e sua aplicação em processos de elevação artificial de petróleo

The using of supervision systems has become more and more essential in accessing, managing and obtaining data of industrial processes, because of constant and frequent developments in industrial automation. These supervisory systems (SCADA) have been widely used in many industrial environments to store process data and to control the processes in accordance with some adopted strategy. The SCADA s control hardware is the set of equipments that execute this work. The SCADA s supervision software accesses process data through the control hardware and shows them to the users. Currently, many industrial systems adopt supervision softwares developed by the same manufacturer of the control hardware. Usually, these softwares cannot be used with other equipments made by distinct manufacturers. This work proposes an approach for developing supervisory systems able to access process information through different control hardwares. An architecture for supervisory systems is first defined, in order to guarantee efficiency in communication and data exchange. Then, the architecture is applied in a supervisory system to monitor oil wells that use distinct control hardwares. The implementation was modeled and verified by using the formal method of the Petri networks. Finally, experimental results are presented to demonstrate the applicability of the proposed solution

Modelagem e controle adaptativo de uma planta didática de nível com instrumentação industrial

The control, automation and optimization areas help to improve the processes used by industry. They contribute to a fast production line, improving the products quality and reducing the manufacturing costs. Didatic plants are good tools for research in these areas, providing a direct contact with some industrial equipaments. Given these capabilities, the main goal of this work is to model and control a didactic plant, which is a level and flow process control system with an industrial instrumentation. With a model it is possible to build a simulator for the plant that allows studies about its behaviour, without any of the real processes operational costs, like experiments with controllers. They can be tested several times before its application in a real process. Among the several types of controllers, it was used adaptive controllers, mainly the Direct Self-Tuning Regulators (DSTR) with Integral Action and the Gain Scheduling (GS). The DSTR was based on Pole-Placement design and use the Recursive Least Square to calculate the controller parameters. The characteristics of an adaptive system was very worth to guarantee a good performance when the controller was applied to the plant