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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Otimização de um forno de reaquecimento a óleo - controle de emissões e crédito de carbono /

Sugahara, Dickson. January 2007 (has links)
Orientador: João Andrade de Carvalho Junior / Banca: Pedro Magalhães Sobrinho / Banca: Jorge Alberto Soares Tenório / Resumo: Esse trabalho destina-se ao estudo da relação entre as condições de operação e o nível de emissão de CO2 em um forno de soleira rotativa, a óleo, utilizado para o reaquecimento de blocos de aço carbono para forjamento de rodas ferroviárias. O foco principal foi a redução na emissão de CO2 e a possibilidade de geração de créditos de carbono. Inicialmente foram apresentadas as características do sistema de aquecimento e suas influências no desempenho geral do forjamento. Em complemento foram expostas algumas condições de emissões relacionadas ao combustível e ao funcionamento do sistema de combustão. Foram selecionados parâmetros para a correção das condições de operação e ajustados para o tipo de combustível utilizado. A verificação foi feita através de análises de atmosfera. A metodologia foi eficiente e mostrou uma redução de 0,5% na concentração de CO2 nos gases de combustão que equivale a uma redução de 3,6% na emissão total de CO2. / Abstract: This work studied the relation between the operation condition and the level of CO2 emission in an oil rotary furnace used to reheat steel carbon blocks to forge rail wheels. The main focus was a CO2 reduction emission and carbon credits revenue. Initially, the heating system characteristics and its influence in the forging performance were presented. Additionally, some emission conditions related to the fuel and combustion system working were exposed. Parameters were selected to correct the operation condition and adjusted to the type of the fuel used. The results were verified by atmosphere analysis. The methodology was efficient and shows 0,5% reduction in the concentration of CO2 in the combustion gases or 3,6% reduction in CO2 total emission. / Mestre
72

Experimental Verification and Comparison of Different Stabilizing Controllers for a Rotary Inverted Pendulum

AL-Jodah, Ammar Abdulhussein 01 December 2013 (has links)
This thesis focuses on implementation of the swing-up, switching and stabilizing controllers for the rotary inverted pendulum. An energy based method to swing-up the pendulum and a state feedback controller to keep the pendulum in the upright position are employed. The mixed H2/H∞; state feedback controller is used to stabilize the pendulum with reduced oscillations. The results have been compared with the standard full state feedback and LQR. The Quanser rotary inverted pendulum is used as the testbed. All controllers are implemented in real-time using dSPACE 1104 rapid prototyping system. Microstick II with dsPIC33FJ128MC802 and Simulink embedded target for Microchip® is used as a standalone way to implement the controllers.
73

Modification and Performance Evaluation of a Mono-valve Engine

Behrens, Justin William 01 August 2011 (has links)
AN ABSTRACT OF THE THESIS OF Justin W. Behrens, for the Master of Science degree in Mechanical Engineering, presented on June 24, 2011 at Southern Illinois University Carbondale. TITLE: MODIFICATION AND PERFORMANCE EVALUATION OF A MONO-VALVE ENGINE MAJOR PROFESSOR: Dr. Suri Rajan A four-stroke engine utilizing one tappet valve for both the intake and exhaust gas exchange processes has been built and evaluated. The engine operates under its own power, but has a reduced power capacity than the conventional 2-valve engine. The reduction in power is traced to higher than expected amounts of exhaust gases flowing back into the intake system. Design changes to the cylinder head will fix the back flow problems, but the future capacity of mono-valve engine technology cannot be estimated. The back flow of exhaust gases increases the exhaust gas recirculation (EGR) rate and deteriorates combustion. Intake pressure data shows the mono-valve engine requires an advanced intake valve closing (IVC) time to prevent back flow of charge air. A single actuation camshaft with advanced IVC was tested in the mono-valve engine, and was found to improve exhaust scavenging at TDC and nearly eliminated all charge air back flow at IVC. The optimum IVC timing is shown to be approximately 30 crank angle degrees after BDC. The mono-valve cylinder head utilizes a rotary valve positioned above the tappet valve. The open spaces inside the rotary valve and between the rotary valve and tappet valve represent a common volume that needs to be reduced in order to reduce the base EGR rate. Multiple rotary valve configurations were tested, and the size of the common volume was found to have no effect on back flow but a direct effect on the EGR rate and engine performance. The position of the rotary valve with respect to crank angle has a direct effect on the scavenging process. Optimum scavenging occurs when the intake port is opened just after TDC.
74

Advanced control of a rotary dryer

Yliniemi, L. (Leena) 01 June 1999 (has links)
Abstract Drying, especially rotary drying, is without doubt one of the oldest and most common unit operations in the process industries. Rotary dryers are workhorses which are easy and reliable to operate, but neither energy-efficient nor environmentally friendly. In order to conform better to the requirements of modern society concerning working conditions, safety practices and environmental aspects, the development of control systems can provide opportunities for improving dryer operation and efficiency. Our in depth understanding of rotary drying is poor, because it is a very complex process that includes the movement of solids in addition to thermal drying. Thus even today rotary dryers are controlled partly manually, based on the operator's "eye" and experience, and partly relying on conventional control methods. The control of a rotary dryer is difficult due to the long time delay, which means that accidental variations in the input variables can disturb the process for long periods of time before they are reflected in the output variables. To eliminate such disturbances at an early stage, increasing interest has been shown in more sophisticated control systems such as model-based constructs, fuzzy logic and neural nets in recent years. Although it has proved difficult and time-consuming to develop model-based control systems, due to the complexity of the process, intelligent control methods based on fuzzy logic and neural nets offer attractive solutions for improving dryer control. These methods make it possible to utilize experience, knowledge and historical data, large amounts of which are readily available. The aim of this research was to improve dryer control by developing new hybrid control systems, one consisting of a fuzzy logic controller (FLC) and PI controller and the other of a three-layer neural network (NN) and PI controller. The FLC and NN act as supervisory controllers giving set points for the PI controllers. The performance of each was examined both with simulations and in pilot plant experiments. The pilot plant dryer at the University of Oulu closely resembles a real industrial situation, so that the results are relevant. Evaluation of these results showed that the intelligent hybrid controllers are well suited for the control of a rotary dryer, giving a performance in which disturbances can be eliminated rapidly and operation of the dryer can thereby be improved, with the aim of enhancing its efficiency and environmental friendliness.
75

Design vstřikovacího lisu / Design of machine for injection molding

Multáňová, Katarína January 2010 (has links)
Diploma thesis deals with the development of injection moulding machine design. It is a type of industrial machine, which is designed for production of plastic parts by technology of compression molding. Injection and closing units in the machine are vertical orientated to each other. Injection moulding machine is equipped with rotary table. The main task of diploma work is to design an injection moulding machine with original shape for the future. Conception of the machine is based on present progresive technical solutions. Design of the machine tolerates main ergonomic demands and make the work for operating personnel easier.
76

Controlling Weldment and Metallurgical Properties Through Process Control in Rotary Friction Welding

Taysom, Brandon Scott Boyer 24 September 2019 (has links)
Weld quality in the context of process control and internal conditions is studied. Several different alloys are welded including plain carbon steel, high-temperature steels, and several traditional and advanced superalloys. Across all studied weld systems, the following conditions led to stronger welds: higher forces and feedrates, lower temperatures, and moderate or limited upsets. In the best cases, post-weld strengths were nearly equal to basemetal strength. Tradition holds that large and symmetric upsets are necessary for good welds, but this study contradicts that notion. The fundamental requirements for bonding are two sufficiently clean surfaces in intimate contact. Only minimal upset is necessary to achieve that. In welding alloy 718, only 1 mm of feed (or ~0.4 mm of sample upset) was necessary to achieve $>$95\% of basemetal strength. In an advanced superalloy with low ductility, very low upsets were required in order to achieve high joint strength. For this low-ductility alloy, using a containing geometry increased both the internal pressure and ductility of this alloy, leading to a much larger window of sound welding conditions and stronger welds overall. In several dissimilar alloy systems, the relationship between force/feedrate and upset asymmetry varied between each alloy, but a more symmetric upset did not correlate to stronger welds. Advanced process control in FW was also performed with closed-loop temperature control and open-loop predictive cooling rate control. Using this technique, martensitic microstructures associated with a fast natural cooling rate were avoided, and a pearlitic microstructure was obtained. The yield and tensile strength of the weld was not adversely affected, and both were within range of published values for the basemetal.
77

Contrôle adaptif d'un calcinateur de bioxyde de titane utilisant la méthode de Clarke et Gawthorp.

Gendron, Sylvain. January 1981 (has links)
No description available.
78

Efficient Way of Reading Rotary Dial Utility Meter Using Image Processing

Souare, Moussa January 2009 (has links)
No description available.
79

A Parametric Study of Micro Atomizing Nozzles on a Rotary Fuel Slinger

Jones, Nicholas Scott January 2014 (has links)
No description available.
80

A NOVEL APPROACH FOR THE MANUFACTURING OF EXTENDED RELEASE PELLETS

MENENDEZ, CARLOS JUAN 02 July 2003 (has links)
No description available.

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