Examination timetabling automation using hybrid meta-heuristics

Trabalho de projeto realizado para obtenção do grau de Mestre em Engenharia Informática e de Computadores

Assessment and control of nanoparticles exposure in welding operations by use of a control banding tool

This paper describes the use of a Control Banding Tool to assess and further control of exposure of nanoparticles emitted during welding operations. The tool was applied to Metal Active Gas (MAG) arc welding of mild and stainless steel, providing semi-quantitative data on the process, so that protection measures could be derived, e.g. exhaust gas ventilation by hoods, local ventilation devices and containment measures. This tool is quite useful to compare and evaluate the characteristics of arc welding procedures so that more eco-friendly processes could be preferred over the more potentially noxious ones.

Laser welding of shape memory alloys

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Mecânica

Magnetic pulse welding

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do Grau de Mestre em Engenharia Mecânica

Estudo de um equipamento de processamento de soldaduras por Friction Stir Welding

Este é um projeto I&D interno do INEGI, com as unidades DPS e LOME, que tem em vista a utilização de componentes disponíveis no INEGI para o estudo de um equipamento capaz de efetuar soldaduras por Friction Stir Welding. O equipamento já conta com controlo numérico para um sistema de três eixos e os respetivos motores, ficando assim encarregue de tirar o máximo proveito possível destes componentes. Este equipamento terá como finalidade munir o INEGI com um equipamento capaz de dar resposta a eventuais projetos externos/internos bem como para fins de investigação para a melhoria da qualidade do processo de soldadura. A conceção deste equipamento tem a particularidade das condições envolventes do processo nomeadamente os esforços desenvolvidos durante o processo de soldadura, em particular a força vertical (eixo da ferramenta) que é necessária fazer de forma a evitar a ascensão de material da junta de soldadura. A soldadura por Friction Stir Welding, é um processo de soldadura relativamente actual, desenvolvido em 1991 por Wayne Thomas pelo The Welding Institute que se sobrepõe aos métodos de soldadura convencionais, uma vez que não necessita de levar o/os materiais acima da sua temperatura de fusão, sendo um processo de soldadura no estado solido, o material não chega a fundir. Este processo consiste na utilização de uma ferramenta em rotação que que se desloca ao longo da junta de soldadura, que uma vez a fricção gerada entre a ferramenta e o material base gera calor que promove o aquecimento e quase fusão do material base. A ligação do material dá-se aquando a passagem da ferramenta na junta, misturando os materiais. Com o recurso a este método de fabrico é possível efetuar soldaduras com grande qualidade em materiais considerados de difícil soldabilidade pelos métodos convencionais, como por exemplo o Alumínio. Neste projecto foram estudadas varias soluções, contactados vários fornecedores e com o seu feedback foi desenvolvido o equipamento. Este projecto consiste essencialmente na análise estrutural e selecção de equipamentos. O equipamento final resultou de uma série de iterações e ideias de forma a optimizar toda estrutura para a magnitude dos esforços envolvidos, obtendo no final um equipamento capaz de cumprir os requisitos. No final prevêse um equipamento com a capacidade de suportar esforços verticais de 50

Production of aluminium based composites reinforced with embedded NiTi by friction stir welding

Dissertação para a obtenção do grau de Mestre em Engenharia Mecânica

Service-oriented architecture for device lifecycle support in industrial automation

Dissertação para obtenção do Grau de Doutor em Engenharia Electrotécnica e de Computadores Especialidade: Robótica e Manufactura Integrada

Gas tungsten arc welding of NiTi shape memory alloy

Shape memory alloys are characterized by the ability of recovering their initial shape after being deformed and by superelasticity. Since the discovery of these alloys, a new field of interest emerged not only for the scientific community but also to many industries. However, these alloys present poor machinability which constitute a constrain in the design of complex components for new applications. Thus, the demand for joining techniques able to join these alloys without compromising their properties became of great importance to enlarge the complexity of existing applications. Literature shows that these alloys are joined mainly using laser welding. In the present study, similar NiTi butt joints, were produced using TIG welding. The welds were performed in 1.5 mm thick plates across the rolling direction. A special fixture and gas assist device was designed and manufactured. Also a robot arm was adapted to accommodate the welding torch to assure the repeatability of the welding parameters. Welds were successfully achieved without macroscopic defects, such as pores and distortions. Very superficial oxidation was seen on the top surface due to insufficient shielding gas flow on the weld face. The welded joints were mechanically tested and structurally characterized. Testing methods were used to evaluate macro and microstructure, as well as the phase transformation temperatures, the mechanical single and cyclic behaviour and the shape recovery ability. Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), microhardness measurements were techniques also used to evaluate the welded joints. A depletion in Ni in the fusion zone was seen, as well as a shift in Ms temperature. For strain values of 4% the accumulated irrecoverable strain was of about 30% and increased with the strain imposed during cycling. Nevertheless, a complete recovery of initial shape was observed when testing the shape memory effect on a dedicated device that introduces a deformation of 6.7%. That is, the welding procedure does not remove the ability of the specimens to recover their initial shape.

How could marketing automation impact the business performance of Comexposium?

Comexposium continues to exhibit strong growth through global acquisition of key events. However, the company identified the need to increase the renewal rate of its exhibitors. In order to do so, Comexposium determined marketing automation software could have enormous value. However, the company currently does not have the appropriate data to determine to specific returns the software could provide. Thus, this report focused on assessing the impact of marketing automation on the business performance of a B2B enterprise and the best methods to implement and measure it. The main findings were that the software could be of immense value to Comexposium, if the company is ready to invest in internal resources and take the time to adapt to the changes the tool will incur.

Electron Beam Welding In-Process Control and Monitoring

This work presents the results of an investigation of processes in the melting zone during Electron Beam Welding(EBW) through analysis of the secondary current in the plasma.The studies show that the spectrum of the secondary emission signal during steel welding has a pronounced periodic component at a frequency of around 15–25 kHz. The signal contains quasi-periodic sharp peaks (impulses). These impulses have stochastically varying amplitude and follow each other inseries, at random intervals between series. The impulses have a considerable current (up to 0.5 A). It was established that during electron-beam welding with the focal spot scanning these impulses follow each other almost periodically. It was shown that the probability of occurrence of these high-frequency perturbation increases with the concentration of energy in the interaction zone. The paper also presents hypotheses for the mechanism of the formation of the high-frequency oscillations in the secondary current signal in the plasma.

Integrated consideration of product quality within factory automation systems

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2013

Simulation von Koexistenzszenarien für die Automation mit SEAMCAT an einem Anwendungsbeispiel

Diese Arbeit beschäftigt sich mit Koexistenzaussagen von Funktechnologien. Dafür wurden verschiedene Simulationstools auf ihre Eignung untersucht. Einen besonderen Schwerpunkt nimmt das Tool SEAMCAT ein. In der Arbeit wurde ein Modell ausgearbeitet, das für die Simulation mit SEAMCAT geeignet ist. Ergebnisse wurden mit Messungen verglichen, die das ifak Magdeburg für das System erstellt haben. Empfehlungen und Ausblicke für Funktechnologien in der Automation wurden abschließend benannt.

Strategies for the successful implementation of viral laboratory automation.

It has been estimated that more than 70% of all medical activity is directly related to information providing analytical data. Substantial technological advances have taken place recently, which have allowed a previously unimagined number of analytical samples to be processed while offering high quality results. Concurrently, yet more new diagnostic determinations have been introduced - all of which has led to a significant increase in the prescription of analytical parameters. This increased workload has placed great pressure on the laboratory with respect to health costs. The present manager of the Clinical Laboratory (CL) has had to examine cost control as well as rationing - meaning that the CL's focus has not been strictly metrological, as if it were purely a system producing results, but instead has had to concentrate on its efficiency and efficacy. By applying re-engineering criteria, an emphasis has had to be placed on improved organisation and operating practice within the CL, focussing on the current criteria of the Integrated Management Areas where the technical and human resources are brought together. This re-engineering has been based on the concepts of consolidating and integrating the analytical platforms, while differentiating the production areas (CORE Laboratory) from the information areas. With these present concepts in mind, automation and virological treatment, along with serology in general, follow the same criteria as the rest of the operating methodology in the Clinical Laboratory.