Equations of motion for constrained systems

"Series title: Springerbriefs in applied sciences and technology, ISSN 2191-530X"

Um modelo de planeamento económico aplicado ao sector agro-alimentar em Portugal: utilização da análise multi-objectivos.

Doutoramento em Economia.

Espectroscopía de emisión de rayos x. Aplicación a la caracterización de materiales. X-ray emission spectroscopy. Application to materials characterization

La idea principal del proyecto abarca el estudio de parámetros y fenómenos físicos. Los avances logrados se aplicarán al desarrollo de software y metodologías para cuantificación de materiales mediante microanálisis con sonda de electrones y microscopía electrónica de barrido. El microanálisis no es una técnica absoluta, sino que requiere de estándares de referencia, para obviar el uso de ciertos parámetros geométricos y atómicos difíciles de conocer con una precisión adecuada. Para contar con un método sin estándares debe abordarse la determinación de parámetros atómicos e instrumentales, que es uno de los aspectos que se desea encarar en este proyecto. Por otro lado, también se pretende incluir los parámetros estudiados en un software de cuantificación desarrollado por integrantes del proyecto. Otro de los propósitos del plan de trabajo es estudiar la potencialidad de la resolución espacial de una microsonda de electrones con el fin de desarrollar una metodología para caracterizar interfases, bordes de granos e inclusiones, con resolución submicrométrica, ya que los métodos tradicionales de cuantificación se restringen al caso de muestras planas y homogéneas dentro del volumen de interacción, pero la caracterización de inhomogeneidades a nivel micrométrico no ha sido desarrollada todavía, salvo algunas excepciones. The main idea of this project involves the study of physical parameters and phenomena. The concretion of the different goals will permit the elaboration of softeare and methodologies for materials characterization by means of electron probe microanalysis and scanning microscopy. Electron probe microanalysis is not an absolute technique, but requires reference standards in order not to involve certain geometrical and atomic parameters for which high uncertainties cannot be avoided. In order to have standardless method, the determination of atomic and instrumental parameters must be accomplished, as will be faced through this project. Complementary, the parameters studied will be included in a quantification software developed in our research group of FaMAF. Another objective of this activity plan is to study the spatial resolution potentiality of a focalized electron beam, with the aim of characterizing interphases, grain boundaries and inclusions with submicron sensitivity, since the traditional quantification procedures are restricted to flat homogeneous samples, whereas the characterization of inhomogeneities has not been developed yet.

Modelado multi-dominio de máquinas eléctricas. Multi-domain modeling of electric machines

El objetivo general de este proyecto es desarrollar nuevos modelos multi-dominio de máquinas eléctricas para aplicaciones al control y al diagnóstico de fallas. Se propone comenzar con el modelo electromagnético del motor de inducción en base a circuitos magnéticos equivalentes (MEC) validándolo por medio de simulación y de resultados experimentales. Como segundo paso se pretende desarrollas modelos térmicos y mecánicos con el objetivo que puedan ser acoplados al modelo electromagnético y de esta estudiar la interacción de los dominios y se validará mediante resultados de simulación y experimentales el modelo completo. Finalmente se pretende utilizar el modelo multi-dominio como una herramienta para la prueba de nuevas estrategias de control y diagnóstico de fallas. The main objective of this project is the development of new multi-domain models of electric machines for control and fault diagnosis applications. The electromagnetic modeling of the induction motor (IM) will be done using the magnetic equivalent circuits approach. This model will be validated by simulation and by experimental results. As a second step of this project, new mechanical and thermal models for the IM will be developed, with the objective of coupling these models with the electromagnetic one. With this multi-domain model it will be possible to study the interaction between each others. After that, the complete model will be validated by simulation and experimental results. Finally, the model will be used as a tool for testing new control and fault diagnosis strategies.

The spatial analysis and speciation of uranium and thorium series radionuclides in the soil of the Cronamuck Valley, County Donegal, Ireland

This thesis details the findings of a study into the spatial distribution and speciation of 238U, 226Ra and 228Ra in the soils of the Cronamuck valley, County Donegal . The region lies on the north-eastern edge of the Barnesmore granite and has been the subject of uranium prospecting efforts in the past. The results of the project provide information on the practicability of geostatistical techniques as a means of estimating the spatial distribution of natural radionuclides and provide insight into the behaviour of these nuclides and their modes of occurrence and enrichment in an upland bog environment. The results of the geostatistical survey conducted on the area indicate that the primary control over the levels of the studied nuclides in the soil of the valley is the underlying geology. Isopleth maps of nuclide levels in the valley indicate a predominance of elevated nuclide levels in the samples drawn from the granite region, statistical analysis of the data indicating that levels of the nuclides in samples drawn from the granite are greater than levels drawn from the non-granite region by up to a factor of 4.6 for 238U and 4.9 for 226Ra. Redistribution of the nuclides occurs via drainage systems within the valley, this process being responsible for transport of nuclides away from the granite region resulting in enrichment of nuclides in soils not underlain by the granite. Distribution of the nuclides within the valley is erratic, the effect of drainage f lows on the nuclides resulting in localized enriched areas within the valley. Speciation of the nuclides within one of the enriched areas encountered in the study indicates that enrichment is as a result of saturation of the soil with drainage water containing trace amounts of radionuclides. 238U is primarily held within the labile fractions (exchangeable cat ions + easily oxidisable organics + amorphous iron oxides ) of the soil , 226Ra being associated with the non- labile fractions, most probably the resistant organic material. 228Ra displays a significant occurrence in both the labile and non- labile fractions. The ability of the soil to retain uranium appears to be affected largely by the redox status of the soil, samples drawn from oxidizing environments tending to have little or no uranium in the easily oxidisable and amorphous iron oxide fractions. This loss of uranium from oxidised soil samples is responsible for the elevated 226Ra /238U disequilibrium encountered in the enriched areas of the valley. Analysis of the data indicates that samples displaying elevated 226Ra/238U ratios also exhibit elevated 228Ra/238U ratios indicating a loss of uranium from the samples as opposed to an enrichment of 226Ra.

Potentially viable solar powered appliances cooling and distillation

Stand alone solar powered refrigeration and water desalination, two of the most popular and sought after applications of solar energy systems, have been selected as the topic of research for the works presented in this thesis. The water desalination system based on evaporation and condensation was found to be the most suitable one to be powered by solar energy. It has been established that highoutput fast-response solar heat collectors used to achieve high rates of evaporation and reliable solar powered cooling system for faster rates of condensation are the most important factors in achieving increased outputs in solar powered desalination systems. Comprehensive reviews of Solar powered cooling/refrigeration and also water desalination techniques have been presented. In view of the fact that the Institute of Technology, Sligo has a well-established long history of research and development in the production of state of the art high-efficiency fast-response evacuated solar heat collectors it was decided to use this know how in the work described in this thesis. For this reason achieving high rates of evaporation was not a problem. It was, therefore, the question of the solar powered refrigeration that was envisaged to be used in the solar powered desalination tofacilitate rapid condensation of the evaporated water that had to be addressed first. The principles of various solar powered refrigeration techniques have also been reviewed. The first step in work on solar powered refrigeration was to successfully modify a conventional refrigerator working on Platen-Munters design to be powered by highoutput fast-response evacuated solar heat collectors. In this work, which was the first ever successful attempt in the field, temperatures as low as —19°C were achieved in the icebox. A new approach in the use of photovoltaic technology to power a conventional domestic refrigerator was also attempted. This was done by modifying a conventional domestic refrigerator to be powered by photovoltaic panels in the most efficient way. In the system developed and successfully tested in this approach, the power demand has been reduced phenomenally and it is possible to achieve 48 hours of cooling power with exposure to just 7 hours of sunshine. The successful development of the first ever multi-cycle intermittent solar powered icemaker is without doubt the most exciting breakthrough in the work described in this thesis. Output of 74.3kg of ice per module with total exposure area of 2.88 m2, or 25.73kg per m2, per day is a major improvement in comparison to about 5-6kg of ice per m2 per day reported for all the single cycle intermittent systems. This system has then become the basis for the development of a new solar powered refrigeration system with even higher output, named the “composite” system described in this thesis. Another major breakthrough associated with the works described in this thesis is the successful development and testing of the high-output water desalination system. This system that uses a combination of the high-output fast-response evacuated solar heat collectors and the multi-cycle icemaker. The system is capable of producing a maximum of 141 litres of distilled water per day per module which has an exposure area of 3.24m2, or a production rate of 43.5 litres per m2 per day. Once again when this result is compared to the reported daily output of 5 litres of desalinated water per m per day the significance of this piece of work becomes apparent. In the presentation of many of the components and systems described in this thesis CAD parametric solid modelling has been used instead of photographs to illustrate them more clearly. The multi-cycle icemaker and the high-output desalination systems are the subject of two patent applications.

Síndrome Metabólica, Strain e Redução da Função Miocárdica: Multi-Ethnic Study of Atherosclerosis

Fundamento: A doença cardiovascular subclínica é prevalente em pacientes com síndrome metabólica (SM). O strain circunferencial (εCC) e o strain longitudinal (εLL) do ventriculo esquerdo (VE), avaliados pelo ecocardiograma com speckle tracking (STE), são índices de função sistólica: o encurtamento das fibras circunferenciais e longitudinais do VE é indicado por um valor negativo do strain. Portanto, quanto mais negativo o strain, melhor a função sistólica do VE. O εCC e o εLL têm sido usados para demonstrar disfunção ventricular subclínica em vários distúrbios clínicos. Objetivo: Levantamos a hipótese de que a SM está associada com comprometimento da função miocárdica, quando avaliada pelo STE. Métodos: Este estudo analisou participantes do Multi-Ethnic Study of Atherosclerosis (MESA) que realizaram o STE e foram avaliados para todos os componentes da SM. Resultados: Entre os 133 participantes incluídos (mulheres: 63%; idade: 65 ± 9 anos), a prevalência de SM foi de 31% (41/133). Indivíduos com SM apresentaram valores menores do εCC e do εLL que aqueles sem SM (-16,3% ± 3,5% vs. -18,4% ± 3,7%, p < 0,01; e -12,1% ± 2,5% vs. -13,9% ± 2,3%, p < 0,01, respectivamente). A fração de ejeção do VE (FEVE) foi semelhante nos dois grupos (p = 0,09). Na análise multivariada, a SM associou-se a um valor mais baixo do strain circunferencial (B = 2,1%, IC 95%: 0,6-3,5; p < 0,01), mesmo após ajuste para idade, etnia, massa VE e FEVE. De maneira semelhante, a presença de SM (B = 1,3%, IC 95%: 0,3-2,2; p < 0,01) e a massa do VE (B = 0,02%, IC 95%: 0,01 0,03; p = 0,02) associaram-se a um valor menor do strain longitudinal após ajuste para etnia, FEVE e creatinina. Conclusão: O εCC e o εLL do VE, marcadores de doença cardiovascular subclínica, estão comprometidos em indivíduos assintomáticos com SM e sem história prévia de infarto miocárdico, insuficiência cardíaca e/ou de FEVE < 50%.

Spatial data mining in precision agriculture

Magdeburg, Univ., Fak. für Informatik, Diss., 2012

3-D surface reconstruction using spatial frequency-based approaches under influence of perspective distortion

Magdeburg, Univ., Fak. für Elektrotechnik und Informationstechnik, Diss., 2008

Spatio-temporal dynamics of glycolysis in an open spatial reactor

Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2008

Attitudes toward corporate sustainability : a multi-item scale and a multi-country empirical analysis

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

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.

Implementation of Multi-Core Processor Based on PLASMA (Most MIPS I) IP Core

Multi-core processors is a design philosophy that has become mainstream in scientific and engineering applications. Increasing performance and gate capacity of recent FPGA devices has permitted complex logic systems to be implemented on a single programmable device. By using VHDL here we present an implementation of one multi-core processor by using the PLASMA IP core based on the (most) MIPS I ISA and give an overview of the processor architecture and share theexecution results.

Micro-macro analysis of creep behavior in a multi-pass weld

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2014

Multi-echo radial FLASH techniques for real-time MRI

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2015