Instrumentation and measurement platform aeronautics inspired, based on LabView

Within the framework of this thesis a graphical interface in the programming environment of LabView is to be developed. LabView is a software system of National Instruments which facilitatesdata acquisition anddata control.The main goal of the project is to visualise outgoings of several sensorsrelated to aeronauticson a panel which analyses the signals and eventually permits to use them for further employments.This implies a selection of sensorswhich are importantin the aeronautic area within previously settled criteria and connecting them to the programming environment. This accomplisheda software isto be developed in order to acquire the data of the connected sensors, process and allocatethem to further employment. The interface between user and software will be the panel on which the analysed data of the sensors will be represented.Considering all mentioned above,this project provides students the possibility to gain an inside in the concepts of instrumentation and in the handling of data within a programming environmentas LabView.Incomin

Design and validation of a structural health monitoring system for aeronautical structures.

Structural Health Monitoring (SHM) is an area where the main objective is the verification of the state or the health of the structures in order to ensure proper performance and maintenance cost savings using a sensor network attached to the structure, continuous monitoring and algorithms. Different benefits are derived from the implementation of SHM, some of them are: knowledge about the behavior of the structure under different loads and different environmental changes, knowledge of the current state in order to verify the integrity of the structure and determine whether a structure can work properly or whether it needs to be maintained or replaced and, therefore, to reduce maintenance costs. The paradigm of damage identification (comparison between the data collected from the structure without damages and the current structure in orderto determine if there are any changes) can be tackled as a pattern recognition problem. Some statistical techniques as Principal Component Analysis (PCA) or Independent Component Analysis (ICA) are very useful for this purpose because they allow obtaining the most relevant information from a large amount of variables. This thesis uses an active piezoelectric system to develop statistical data driven approaches for the detection, localization and classification of damages in structures. This active piezoelectric system is permanently attached to the surface of the structure under test in order to apply vibrational excitations and sensing the dynamical responses propagated through the structure at different points. As pattern recognition technique, PCA is used to perform the main task of the proposed methodology: to build a base-line model of the structure without damage and subsequentlyto compare the data from the current structure (under test) with this model. Moreover, different damage indices are calculated to detect abnormalities in the structure under test. Besides, the localization of the damage can be determined by means of the contribution of each sensor to each index. This contribution is calculated by several different methods and their comparison is performed. To classify different damages, the damage detection methodology is extended using a Self-Organizing Map (SOM), which is properly trained and validated to build a pattern baseline model using projections of the data onto the PCAmodel and damage detection indices. This baseline is further used as a reference for blind diagnosis tests of structures. Additionally, PCA is replaced by ICAas pattern recognition technique. A comparison between the two methodologies is performed highlighting advantages and disadvantages. In order to study the performance of the damage classification methodology under different scenarios, the methodology is tested using data from a structure under several different temperatures. The methodologies developed in this work are tested and validated using different structures, in particular an aircraft turbine blade, an aircraft wing skeleton, an aircraft fuselage,some aluminium plates and some composite matarials plates.La monitorización de daños en estructuras (SHM por sus siglas en inglés) es un área que tiene como principal objetivo la verificación del estado o la salud de la estructura con el fin de asegurar el correcto funcionamiento de esta y ahorrar costos de mantenimiento. Para esto se hace uso de sensores que son adheridos a la estructura, monitorización continua y algoritmos. Diferentes beneficios se obtienen de la aplicación de SHM, algunos de ellos son: el conocimiento sobre el desempeño de la estructura cuando esta es sometida a diversas cargas y cambios ambientales, el conocimiento del estado actual de la estructura con el fin de determinar la integridad de la estructura y definir si esta puede trabajar adecuadamente o si por el contrario debe ser reparada o reemplazada con el correspondiente beneficio del ahorro de gastos de mantenimiento. El paradigma de la identificación de daños (comparación entre los datos obtenidos de la estructura sin daños y la estructura en un estado posterior para determinar cambios) puede ser abordado como un problema de reconocimiento de patrones. Algunas técnicas estadísticas tales como Análisis de Componentes Principales (PCA por sus siglas en inglés) o Análisis de Componentes Independientes (ICA por sus siglas en ingles) son muy útiles para este propósito puesto que permiten obtener la información más relevante de una gran cantidad de variables. Esta tesis hace uso de un sistema piezoeléctrico activo para el desarrollo de algoritmos estadísticos de manejo de datos para la detección, localización y clasificación de daños en estructuras. Este sistema piezoeléctrico activo está permanentemente adherido a la superficie de la estructura bajo prueba con el objeto de aplicar señales vibracionales de excitación y recoger las respuestas dinámicas propagadas a través de la estructura en diferentes puntos. Como técnica de reconocimiento de patrones se usa Análisis de Componentes Principales para realizar la tarea principal de la metodología propuesta: construir un modelo PCA base de la estructura sin daño y posteriormente compararlo con los datos de la estructura bajo prueba. Adicionalmente, algunos índices de daños son calculados para detectar anormalidades en la estructura bajo prueba. Para la localización de daños se usan las contribuciones de cada sensor a cada índice, las cuales son calculadas mediante varios métodos de contribución y comparadas para mostrar sus ventajas y desventajas. Para la clasificación de daños, se amplia la metodología de detección añadiendo el uso de Mapas auto-organizados, los cuales son adecuadamente entrenados y validados para construir un modelo patrón base usando proyecciones de los datos sobre el modelo PCA base e índices de detección de daños. Este patrón es usado como referencia para realizar un diagnóstico ciego de la estructura. Adicionalmente, dentro de la metodología propuesta, se utiliza ICA en lugar de PCA como técnica de reconocimiento de patrones. Se incluye también una comparación entre la aplicación de las dos técnicas para mostrar las ventajas y desventajas. Para estudiar el desempeño de la metodología de clasificación de daños bajo diferentes escenarios, esta se prueba usando datos obtenidos de una estructura sometida a diferentes temperaturas. Las metodologías desarrolladas en este trabajo fueron probadas y validadas usando diferentes estructuras, en particular un álabe de turbina, un esqueleto de ala y un fuselaje de avión, así como algunas placas de aluminio y de material compuest

Development of an Apparatus for the Study of Electron Impact Fragmentation of Molecular Clusters

The aim of the experiment described in this thesis was to generate a beam of molecular clusters and to look at fragmentation processes induced by low-energy electron impact. These processes are studies by time-of-flight detection of ionised and neutral metastable fragments. A beam of molecular clusters is generated using a pulsed supersonic expansion, and this beam is crossed with a pulsed beam of electrons. The electron pulse is 1 μs to provide the necessary time-of-flight resolution. Ionised fragments are detected using a reflectron time-of-flight mass spectrometer with a microchannel plate detector. Neutral metastable fragments are detected using a channeltron with appropriately biased meshes in front to avoid the detection of charged particles. For both types of fragment data acquisition takes place using a multichannel scaler. Detection of the ions is mass resolved, whereas the flight time of the neutral metastable fragments provides information about the kinetic energy these fragments have acquired in the fragmentation process. The ultimate goal of this experiment is to study lowenergy electron impact on biomolecules solvated in water clusters. This is relevant in the context of radiation damage studies. Recent research on radiation damage in biological organisms has demonstrated the relevance of low-energy secondary electrons produced by the radiation. The work described in this thesis involved the development of a working cluster source, which produces excellent methanol and argon mass spectra, via supersonic expansion from a nozzle. A neutral metastable detector has been designed, constructed, and implemented; time-of-flight spectra have been gathered for electron impact on argon clusters, and are in agreement with previous work, indicating the detector is operating well. The electron gun has been adapted to incorporate a deflection system for steering of the electron beam, and now operates well with stability down to 20 eV. Programs have been written using LabVIEW for control of the electron impact energy, and for the acquisition of data and excitation functions, as well as providing quick analysis of mass spectra. Further minor modifications and implementations have been conducted to optimise the overall operation of the system. This developmental work has moved the apparatus at Maynooth closer to its ultimate goal, the study of electron impact fragmentation of molecular clusters

E-Learning

E-learning enables students to pace their studies according to their needs, making learning accessible to (1) people who do not have enough free time for studying - they can program their lessons according to their available schedule; (2) those far from a school (geographical issues), or the ones unable to attend classes due to some physical or medical restriction. Therefore, cultural, geographical and physical obstructions can be removed, making it possible for students to select their path and time for the learning course. Students are then allowed to choose the main objectives they are suitable to fulfill. This book regards E-learning challenges, opening a way to understand and discuss questions related to long-distance and lifelong learning, E-learning for people with special needs and, lastly, presenting case study about the relationship between the quality of interaction and the quality of learning achieved in experiences of E-learning formation

Real-time programming and the big ideas of computational literacy

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2003.Includes bibliographical references (p. 115-121).Though notoriously difficult, real-time programming offers children a rich new set of applications, and the opportunity to engage bodily knowledge and experience more centrally in intellectual enterprises. Moreover, the seemingly specialized problems of real-time programming can be seen as keys to longstanding difficulties of programming in general. I report on a critical design inquiry into the nature and potential of real-time programming by children. A cyclical process of design, prototyping and testing of computational environments has led to two design innovations: a language in which declarative and procedural descriptions of computation are given equal status, and can subsume each other to arbitrary levels of nesting [and] a "live text" environment, in which real-time display of, and intervention in, program execution are accomplished within the program text itself. Based on children's use of these tools, as well as comparative evidence from other media and domains, I argue that the coordination of discrete and continuous process should be considered a central Big Idea in programming and beyond. In addition, I offer the theoretical notion of the "steady frame" as a way to clarify the user interface requirements of real-time programming, and also to understand the role of programming in learning to construct dynamic models, theories, and representations. Implications for the role of programming in education and for the future of computational literacy are discussed.by Christopher Michael Hancock.Ph.D

Thrust and Performance Study of Micro Pulsed Plasma

This research is focused on several areas of the μPPT performance. An important idea studied is the effect of lifetime use on the performance. The thruster is fired for a simulated lifetime of use to see if there is an impact on the thrust of the thruster later in life. Also vital is the efficiency of the thruster. A μPPT performing at max efficiency will ionize all ablated material; however, we know that not to be the case. In this research the effort is made to collect these non-ionized particles in order to measure their mass post-test. With this collected mass and a knowledge of how much the thruster has ablated, it can be determined what percentage of the propellant has been ionized. With the non-ionized particles also comes a concern about contamination. Knowing the amount of particles that can collect at the end of a lifetime of use allows a better understanding of what contamination issues a spacecraft may have and what precautions need to be made