Análise experimental de danos em pistões de motor à gasolina operando com adição de gás hidróxi

The addition of hydrogen gas as an alternative fuel source has been widely used, as well reported in scientific literature. Today, several experiments are underway for the use of hydrogen generators (electrolysers) demand for motor vehicles. In all these products their ads manufacturers claim that this provides a reduction of fuel consumption, reduces the emission levels of toxic gas by the discharge and improves engine life. This research analyzes the physical structure of engine components using electrolysis on demand. To this end, a stationary system was fitted with a power generator of electricity, drum roller and adapted two electrolyzers: a dry cell and wet cell other. In steps observation were consumption analyzes in four work load ranges and observing the piston engine, which has been cut and analyzed by Optical Microscopy (OM), Scanning Electron Microscopy and Dispersive Energy (SEM-EDS), X – Ray Diffraction (XRD) and Confocal Microscopy, the stationary system in each step. The results showed a considerable reduction in fuel consumption and a high corrosion in the original factory piston constituted of aluminum-silicon alloy. As corrosion barrier was made a plasma nitriding in the piston head, which proved resistant to attack by hydrogen, although it has presented evidence also, of having been attacked. It is concluded that the automotive electrolysers can be a good choice in terms of consumption and reducing toxic gas emissions, but the material of the combustion chambers of vehicles must be prepared for this purpose.

Caminhos que estruturam cidades: redes técnicas de transporte sobre trilhos e a conformação intra-urbana de Natal

The railroad, from 1870 and on, becomes an usual complaining in the press s and politician elite s speeches, especially because of Natal s geographic isolation. The implantation of two railroads in the capital territory Estrada de Ferro de Natal a Nova Cruz, afterwards part of Great Western Railway Company network, and Estrada de Ferro Central do Rio Grande do Norte had serious implications in the urban environment. While railroad s structures were already consolidated, other transportation mechanisms were being implanted in the first decades of the 20th century, such as trams lines, which, by the way, was a transport modal that also used rails as a dislocation meaning. Considering these questions, we may ask: how come railroads and tramways demands, roads and buildings had influenced the internal organization of Natal? We work with the general hypothesis that the influence of technical networks, composed by tramways and railroads, over Natal s urban space happened in a diversified way, sometimes consolidating social aspects in certain areas, sometimes improving the occupation of others. The impact over the city s territory also happens in a diversified way between the buildings/railroad s complexes and the pathways. The different scale of the train in comparison to the trams velocity, size, noise level, flow, among others is also a cause to the different consequences in urban environment. The main objective of this work is to understand the role of circulation technical networks in the construction process of urban space in Natal, as a way to contribute to the urban historiography about the subject. The time frame adopted, between 1881 and 1937, marks the time path of railroads and tramways in Rio Grande do Norte: 1881 is the year of railroad s first section inauguration from Natal to São José do Mipibu as well of the railroad complex in the Republic Square in Natal; the year of 1937 marks the beginning of tramways declination process in the city. At this time railroads and tramways had to face more intensively the competition of motor vehicles. The theory reference adopted is based on concepts and analysis of authors, such as Flávio Villaça and Roberto Lobato Corrêa references to the concepts of urban structure , localization and accessibility and Gabriel Dupuy to explain the concept of urban technical networks . These references reveal the conflict of different realities in the urban universe interests and values which is an important factor about the construction of urban space. The information sources used were from two distinctive natures: primary, journals of the time studied and official government reports, and secondary, based on other works about the subject. It was also used by this study iconographic source, especially images from the data base of the research group História da Cidade, do Território e do Urbanismo .

Sistema de sensoriamento eletromagnético utilizado para detecção da contaminação do óleo isolante do motor no método de elevação artificial do tipo bombeio centrífugo submerso

In the artificial lift method by Electrical Submersible Pump (ESP), the energy is transmitted for the well´s deep through a flat electric handle, where it is converted into mechanical energy through an engine of sub-surface, which is connected to a centrifugal pump. This transmits energy to the fluid under the pressure form, bringing it to the surface In this method the subsurface equipment is basically divided into: pump, seal and motor. The main function of the seal is the protect the motor, avoiding the motor´s oil be contaminated by oil production and the consequent burning of it. Over time, the seal will be wearing and initiates a contamination of motor oil, causing it to lose its insulating characteristics. This work presents a design of a magnetic sensor capable of detecting contamination of insulating oil used in the artificial lift method of oil-type Electrical Submersible Pump (ESP). The objective of this sensor is to generate alarm signal just the moment when the contamination in the isolated oil is present, enabling the implementation of a predictive maintenance. The prototype was designed to work in harsh conditions to reach a depth of 2000m and temperatures up to 150°C. It was used a simulator software to defined the mechanical and electromagnetic variables. Results of field experiments were performed to validate the prototype. The final results performed in an ESP system with a 62HP motor showed a good reliability and fast response of the prototype.

Avaliação do desempenho funcional de crianças com paralisia cerebral de acordo com níveis de comprometimento motor

Contextualization: Several studies have examined the mobility of this group of children, however little is known about the impact of motor function in activities of daily living, considering the seriousness of their neuromotor damage. Objective: Identify the functional differences of children with Cerebral Palsy with different levels of motor dysfunction and correlate these differences with the areas of mobility, self-care and social function in functional ability and caregiver´s assistance of these children. Methods: An l analytical cross-section search was developed, which were part 70 children / families aged from 4 to 7.5 years, in the Rehabilitation Center for Children. As tools were used the Pediatric Evaluation Disability Inventory (PEDI) and the Gross Motor Function Classification System (GMFCS). Data analysis was performed by ANOVA and Pearson's correlation tests. Results: The results show the functional variability of children CP in different severity levels of motor disfunction This variation was observed in the areas of mobility, self-care and social function. The results also showed a strong correlation between the domains mobility and self-care, mobility and social function. Conclusions: The variability shown by the children with CP, suggests the use of PEDI and GMFCS as this association appears to increase the understanding of how the gross motor functions are related to activities of daily living, describing the best commitments and their degree of impact on functional activities. This correlation demonstrates how mobility is crucial to evaluate the performance and guide the therapeutic practice, to develop the children´s potencial, and guide the caregiver in stimulation

Estado nutricional, desempenho motor e marcadores dermatoglíficos em escolares púberes

A fase da puberdade é o período em que ocorrem as maiores transformações características da adolescência. Por essa razão, este estudo objetivou identificar o estado nutricional, desempenho motor e marcadores dermatoglíficos em 2363 escolares púberes selecionados de forma estratificada, de ambos os sexos, com idades variando de 6 a 15 anos, matriculados no Ensino Fundamental (2ª a 9ª Séries) do ensino público no estado do Rio Grande do Norte. Foram avaliados o estado nutricional (Índice de Massa Corporal); as qualidades físicas básicas ( testes de coordenação, equilíbrio, agilidade, flexibilidade, força e velocidade); o potencial genético (método da dermatoglifia) e o estágio maturacional (auto avaliação de Tanner); Com relação ao estado nutricional observou-se que escolares acima do peso apresentam valores mais baixos em relação ao seu desempenho motor sendo esses valores, mais significativos nos meninos. No que se refere à maturação sexual, os resultados apontaram que os meninos atingem os estágios maturacionais primeiro que as meninas, não tendo encontrado correlação entre o potencial genético e os demais indicadores o que nos permite concluir que os escolares do estado do Rio Grande do Norte, principalmente os do sexo masculino sofrem influência significativa de seu estado nutricional e seu estágio maturacional no que diz respeito ao seu desempenho motor. Essa dissertação apresenta relação de interdisciplinaridade, tendo o seu conteúdo uma aplicação nos campos da Educação Física, Nutrição, Medicina e Enfermagem.

Caracterização do acidente de trânsito e gravidade do trauma: um estudo em vítimas de um hospital de emergência de Natal

Descriptive exploratory study, with quantitative approach and prospective data performed on the Monsenhor Walfredo Gurgel Hospital Complex (MWGH), in Natal/RN, aiming to classify the type of motor vehicle involved in the accident, the public roadway s user quality and the more frequent injuries; to evaluate the severity of trauma in traffic accident victims; characterized the severity of the injuries and the trauma, and the type of motor vehicle involved. The population comprises 605 traffic accident victims, with data collected between October and December 2007. We used as a support for the evaluation of severity of injuries and trauma the Glasgow Coma Scale (GCSl), the Condensed Abbreviated Injury Scale (CAIS) and the Injury Severity Score (ISS). The results show that 82.8% of the victims were male; 78.4% were aged 18 to 38; the victims originating from the State s Countryside prevailed (43.1%); 24.3% of the population had completed middle-level instruction; 23.1% worked on commerce and auxiliary activities; most (79.4%) was catholic; 48.8% were married/consensual union; 76.2% earned up to two monthly minimum wages; Sunday was the day with the most accidents (25.1%); 47.4% were attended to in under an hour after the event; the motorcycle on its own was responsible for 53.2% of the accidents; 42.3% were attended to by the SAMU; 61.8% were victims of crashes; over half (53.4%) used individual protection equipment (IPE); 49.4% were helmets and 4.0% the seatbelt; 61.3% were motorcycle drivers; 43.3% of the accidents took place in the afternoon shift; from 395 drivers, 55.2% were licensed, and 50.7% among those had been licensed for 1 to 5 years; 90.7% of the victims had GCS1 between 13 and 15 points at the time of evaluation; the body area most affected was the external surface (35.9%); 38.8% of the injuries were light or moderate (AIS=1 and AIS=2); 83.2% had light trauma (ISS between 1 and 15 points). In face of the results, we can conclude that there is a risk for the elevation of injury severity and trauma resulting from traffic accidents, when these events are related to certain variables such as gender, age, weekday, the interval between the accident and the first care, ingestion of drugs, type of accident, the public roadway s user quality, the use of IPE, day shift, body regions and the type of motor vehicle involved in the accident

Impacto urbano ocasionado por empreendimentos da construção civil no entorno da zona de proteção ambiental (zpa-6), Vila de Ponta Negra, Natal/RN

The process of urbanization in recent decades has generated considerable seriousness of problems relating to the use and occupation physical environment of cities. The concentration of population, economic activities and technological standards have reinforced an existing urban environment highly degraded as a consequence of the development style that leads to the predatory use of natural resources. In this context, cities as centers of production and consumption, have the most serious problems of environmental degradation. This study investigated the impacts of the municipal building projects to large-scale vertical in the town of Vila de Ponta Negra, Natal-RN, given the proximity to the Environmental Protection Area (ZPA-6) and considering its environmental importance , scenic, landscape and tourism for the city of Natal-RN. The fragility of the licensing process and the failure of the assumptions in the analysis, objective and subjective, for the granting of environmental permits for the building construction projects, specifically those set out in the surroundings of the Environmental Protection Area (ZPA-6) and fundamental importance of landscape and tourism for the city of Natal, has aroused the concern of local people in and of itself the Government, faced with the probable impacts that will affect greatly the Vila de Ponta Negra. The methodology used to achieve the intended objectives will be the literature review, questionnaire to the surrounding population and the Government, as well as findings on the spot, through the photographic record. The beneficiaries of the license, if the entrepreneurs, have been affected because of the granting of licensing act of investing large amount of capital in the works. Additionally, with distrust of the population, since they are to discredit the public system of environmental management have guessed by the probability of imbalance to the environment and structural damage to the Vila de Ponta Negra, where such failure to support energy, lack of regular supply of water , lack of sanitation and access roads sufficient for the flow of motor vehicles in these areas, among other factors. Thus, this work will contribute to the diagnosis and solutions to the problem in question, so that the Government will effectively fulfill its social management of ecologically balanced environment of continuing urban development in Natal, Brazil

Um algoritmo híbrido para o problema de roteamento de veículos com frotas heterogêneas

This paper aims to propose a hybrid meta-heuristics for the Heterogeneous Fleet Vehicle Routing Problem (HVRP), which is a combinatorial optimization problem NP-hard, and is characterized by the use of a limited fleet consists of different vehicles with different capacities. The hybrid method developed makes use of a memetic algorithm associated with the component optimizer Vocabulary Building. The resulting hybrid meta-heuristic was implemented in the programming language C + + and computational experiments generated good results in relation to meta-heuristic applied in isolation, proving the efficiency of the proposed method.

Controle vetorial de velocidade de um motor de indução trifásico com estimação neural de fluxo

This work describes the study and the implementation of the speed control for a three-phase induction motor of 1,1 kW and 4 poles using the neural rotor flux estimation. The vector speed control operates together with the winding currents controller of the stator phasis. The neural flux estimation applied to the vector speed controls has the objective of compensating the parameter dependences of the conventional estimators in relation to the parameter machine s variations due to the temperature increases or due to the rotor magnetic saturation. The implemented control system allows a direct comparison between the respective responses of the speed controls to the machine oriented by the neural rotor flux estimator in relation to the conventional flux estimator. All the system control is executed by a program developed in the ANSI C language. The main DSP recources used by the system are, respectively, the Analog/Digital channels converters, the PWM outputs and the parallel and RS-232 serial interfaces, which are responsible, respectively, by the DSP programming and the data capture through the supervisory system

Motor de indução trifásico sem mancais com bobinado dividido: otimização do sistema de posicionamento radial

This dissertation dea1s with the active magnetic suspension controI system of an induction bearingIess motor configured with split windings. It analyses a dynamic modeI for the radial magnetic forces actuating on the rotor. From that, it proposes a new approach for the composition of the currents imposed to the machine's stator. It shows the tests accomplished with a prototype, proving the usefulness of the new actuating structure for the radial positioning controI. Finnaly, it points out the importance of adapting this structure to well-known rotational controI techniques, continuing this kind of equipment research, which is carried out at Federal University of Rio Grande do Norte since 2000

Controle preditivo bilinear aplicado a um motor de indução

The present work is based on the applied bilinear predictive control applied to an induction motor. As in particular case of the technique based on predictive control in nonlinem systems, these have desperted great interest, a time that present the advantage of being simpler than the non linear in general and most representative one than the linear one. One of the methods, adopted here, uses the linear model "quasi linear for step of time" based in Generalized Predictive Control. The modeling of the induction motor is made by the Vectorial control with orientation given for the indirect rotor. The system is formed by an induction motor of 3 cv with rotor in squirregate, set in motion for a group of benches of tests developed for this work, presented resulted for a variation of +5% in the value of set-point and for a variation of +10% and -10% in the value of the applied nominal load to the motor. The results prove a good efficiency of the predictive bilinear controllers, then compared with the linear cases

Identificação de uma planta de corrente de um motor de indução utilizando redes de base radial

The present work describes the use of a mathematical tool to solve problems arising from control theory, including the identification, analysis of the phase portrait and stability, as well as the temporal evolution of the plant s current induction motor. The system identification is an area of mathematical modeling that has as its objective the study of techniques which can determine a dynamic model in representing a real system. The tool used in the identification and analysis of nonlinear dynamical system is the Radial Basis Function (RBF). The process or plant that is used has a mathematical model unknown, but belongs to a particular class that contains an internal dynamics that can be modeled.Will be presented as contributions to the analysis of asymptotic stability of the RBF. The identification using radial basis function is demonstrated through computer simulations from a real data set obtained from the plant

Sensores e interfaces com aplicações em motor mancal

Relevant researches have been growing on electric machine without mancal or bearing and that is generally named bearingless motor or specifically, mancal motor. In this paper it is made an introductory presentation about bearingless motor and its peripherical devices with focus on the design and implementation of sensors and interfaces needed to control rotor radial positioning and rotation of the machine. The signals from the machine are conditioned in analogic inputs of DSP TMS320F2812 and used in the control program. This work has a purpose to elaborate and build a system with sensors and interfaces suitable to the input and output of DSP TMS320F2812 to control a mancal motor, bearing in mind the modularity, simplicity of circuits, low number of power used, good noise imunity and good response frequency over 10 kHz. The system is tested at a modified ordinary induction motor of 3,7 kVA to be used with a bearingless motor with divided coil

Controle vetorial para velocidade de um motor de indução trifásico utilizando estimador filtro de Kalman

This paper describes the study, computer simulation and feasibility of implementation of vector control speed of an induction motor using for this purpose the Extended Kalman Filter as an estimator of rotor flux. The motivation for such work is the use of a control system that requires no sensors on the machine shaft, thus providing a considerable cost reduction of drives and their maintenance, increased reliability, robustness and noise immunity as compared to control systems with conventional sensors

Controle de posição com restrição à orientação de um Veículo Aéreo Não-Tripulado tipo Quadrirrotor

Quadrotors aircraft are composed by four propellers mounted on four engines on a cross or x disposition, and, in this structure, the engines on the same arm spin in the same direction and the other arm in the opposite direction. By rotating each helix generates vertical upward thrust. The control is done by varying the rotational speed of each motor. Among the advantages of this type of vehicle can cite the mechanical simplicity of construction, the high degree of maneuverability and the ability to have vertical takeoffs and landings. The modeling and control of quadrirrotores have been a challenge due to problems such as nonlinearity and coupling between variables. Several strategies have been developed to control this type of vehicle, from the classical control to modern. There are air surveillance applications where a camera is fixed on the vehicle to point forward, where it is desired that the quadrotor moves at a fixed altitude toward the target also pointing forward, which imposes an artificial constraint motion, because it is not desired that it moves laterally, but only forwards or backwards and around its axes . This restriction is similar to the naturally existing on robots powered by wheels with differential drive, which also can not move laterally, due to the friction of the wheels. Therefore, a position control strategy similar to that used in this type of robot could be adapted for aerial robots like quadrotor. This dissertation presents and discusses some strategies for the control of position and orientation of quadrotors found in the literature and proposes a strategy based on dynamic control of mobile robots with differential drive, called the variable reference control. The validity of the proposed strategy is demonstrated through computer simulations