Aplicación de herramientas gis para la cartografía y correlación de datos de ensayos no destructivos en el diagnóstico de edificios históricos

La presente tesis propone un nuevo método de cartografía de ensayos no destructivos en edificios históricos mediante el uso de técnicas basadas en SIG. Primeramente, se define el método por el cual es posible elaborar y convertir una cartografía 3D basada en nubes de puntos de un elemento arquitectónico obtenida mediante fotogrametría, en cartografía raster y vectorial, legible por los sistemas SIG mediante un sistema de coordenadas particular que referencian cada punto de la nube obtenida por fotogrametría. A esta cartografía inicial la denominaremos cartografía base. Después, se define el método por el cual los puntos donde se realiza un ensayo NDT se referencian al sistema de coordenadas del plano base, lo que permite la generación de cartografías de los ensayos referenciadas y la posibilidad de obtener sobre un mismo plano base diferentes datos de múltiples ensayos. Estas nuevas cartografías las denominaremos cartografías de datos, y se demostrará la utilidad de las mismas en el estudio del deterioro y la humedad. Se incluirá el factor tiempo en las cartografías, y se mostrará cómo este nuevo hecho posibilita el trabajo interdisciplinar en la elaboración del diagnóstico. Finalmente, se generarán nuevas cartografías inéditas hasta entonces consistentes en la combinación de diferentes cartografías de datos con la misma planimetría base. Estas nuevas cartografías, darán pie a la obtención de lo que se ha definido como mapas de isograma de humedad, mapa de isograma de salinidad, factor de humedad, factor de evaporación, factor de salinidad y factor de degradación del material. Mediante este sistema se facilitará una mejor visión del conjunto de los datos obtenidos en el estudio del edificio histórico, lo que favorecerá la correcta y rigurosa interpretación de los datos para su posterior restauración. ABSTRACT This research work proposes a new mapping method of non-destructive testing in historical buildings, by using techniques based on GIS. First of all, the method that makes it possible to produce and convert a 3D map based on cloud points from an architectural element obtained by photogrammetry, are defined, as raster and vector, legible by GIS mapping systems using a particular coordinate system that will refer each cloud point obtained by photogrammetry. This initial mapping will be named base planimetry. Afterwards, the method by which the points where the NDT test is performed are referenced to the coordinate system of the base plane , which allows the generation of maps of the referenced tests and the possibility of obtaining different data from multiple tests on the same base plane. These new maps will be named mapping data and their usefulness will be demonstrated in the deterioration and moisture study. The time factor in maps will be included, and how this new fact will enable the interdisciplinary work in the elaboration of the diagnosis will be proved. Finally, new maps (unpublished until now) will be generated by combining different mapping from the same planimetry data base. These new maps will enable us to obtain what have been called isograma moisture maps, isograma salinity- maps, humidity factor, evaporation factor, salinity factor and the material degradation factor. This system will provide a better vision of all data obtained in the study of historical buildings , and will ease the proper and rigorous data interpretation for its subsequent restoration.

Non-destructive measurement of U-235 retained in absolute air filters /

"April 15, 1964."

Metodi di indagine acustica per l'integrità strutturale

Questa tesi ha lo scopo di indagare lo stato interno di materiali e strutture di diverso tipo tramite sollecitazione acustica o vibrazionale. Si sono sottoposte le strutture in esame a sollecitazione acustica (mediante speaker) o meccanica (mediante martello strumentato o altro percussore), acquisendo le onde meccaniche di ritorno con trasduttori microfonici, array microfonici, ed accelerometri. Si è valutato, di caso in caso, quale fosse la strumentazione più adeguata e quale il parametro da prendere in considerazione per effettuare una discriminazione tra oggetto integro ed oggetto danneggiato o contenente vuoti o inclusioni. Si è riflettuto sui dati raccolti allo scopo di capire quali caratteristiche accomunino strutture apparentemente diverse tra loro, e quali differenzino in realtà - rispetto alla possibilità di una efficace diagnosi acustica - strutture apparentemente simili. Si è sviluppato uno script su piattaforma MatLab® per elaborare i dati acquisiti. Tutte le analisi effettuate si basano sull'osservazione dello spettro acustico del segnale di ritorno dall'oggetto sollecitato. Ove necessario, si sono osservati la funzione di trasferimento del sistema (per il calcolo della quale si crosscorrelano i segnali di output e di input) o il waterfall. Da questa base, si sono sviluppati parametri specifici per i vari casi. Gli esami più proficui si sono effettuati sui solai, per la verifica dello sfondellamento dei laterizi. Anche lo studio su prodotti dell'industria alimentare (salami) si è rivelato molto soddisfacente, tanto da gettare le basi per la produzione di un tester da utilizzare in stabilimento per il controllo di qualità dei pezzi.

Development of a non-destructive fluorescence technique for analysis of contact lens deposition levels

The primary objective of this research has been to determine the potential of fluorescence spectroscopy as a method for analysis of surface deposition on contact lenses. In order to achieve this it was first necessary to ascertain whether fluorescence analysis would be able to detect and distinguish between protein and lipid deposited on a lens surface. In conjunction with this it was important to determine the specific excitation wavelengths at which these deposited species were detected with the greatest sensitivity. Experimental observations showed that an excitation wavelength of 360nm would detect lipid deposited on a lens surface, and an excitation wavelength of 280nm would detect and distinguish between protein and lipid deposited on a contact lens. It was also very important to determine whether clean unspoilt lenses showed significant levels of fluorescence themselves. Fluorescence spectra recorded from a variety of unworn contact lenses at excitation wavelengths of 360nm and 280nm indicated that most contact lens materials do not fluoresce themselves to any great extent. Following these initial experiments various clinically and laboratory based studies were performed using fluorescence spectroscopy as a method of analysing contact lens deposition levels. The clinically based studies enabled analysis of contact lenses with known wear backgrounds to be rapidly and individually analysed following discontinuation of wear. Deposition levels in the early stages of lens wear were determined for various lens materials. The effect of surfactant cleaning on deposition levels was also investigated. The laboratory based studies involved comparing some of the in vivo results with those of identical lenses that had been spoilt using an in vitro method. Finally, an examination of lysosyme migration into and out of stored ionic high water contact lenses was made.

An assessment of the influence of the industry distribution chain on the oxygen levels in commercial modified atmosphere packaged cheddar cheese using non-destructive oxygen sensor technology

The establishment and control of oxygen levels in packs of oxygen-sensitive food products such as cheese is imperative in order to maintain product quality over a determined shelf life. Oxygen sensors quantify oxygen concentrations within packaging using a reversible optical measurement process, and this non-destructive nature ensures the entire supply chain can be monitored and can assist in pinpointing negative issues pertaining to product packaging. This study was carried out in a commercial cheese packaging plant and involved the insertion of 768 sensors into 384 flow-wrapped cheese packs (two sensors per pack) that were flushed with 100% carbon dioxide prior to sealing. The cheese blocks were randomly assigned to two different storage groups to assess the effects of package quality, packaging process efficiency, and handling and distribution on package containment. Results demonstrated that oxygen levels increased in both experimental groups examined over the 30-day assessment period. The group subjected to a simulated industrial distribution route and handling procedures of commercial retailed cheese exhibited the highest level of oxygen detected on every day examined and experienced the highest rate of package failure. The study concluded that fluctuating storage conditions, product movement associated with distribution activities, and the possible presence of cheese-derived contaminants such as calcium lactate crystals were chief contributors to package failure.

Design and implementation of a non-destructive defect detection technique based on UWB-SAR imaging

In the last twenty years aerospace and automotive industries started working widely with composite materials, which are not easy to test using classic Non-Destructive Inspection (NDI) techniques. Pairwise, the development of safety regulations sets higher and higher standards for the qualification and certification of those materials. In this thesis a new concept of a Non-Destructive defect detection technique is proposed, based on Ultrawide-Band (UWB) Synthetic Aperture Radar (SAR) imaging. Similar SAR methods are yet applied either in minefield [22] and head stroke [14] detection. Moreover feasibility studies have already demonstrated the validity of defect detection by means of UWB radars [12, 13]. The system was designed using a cheap commercial off-the-shelf radar device by Novelda and several tests of the developed system have been performed both on metallic specimen (aluminum plate) and on composite coupon (carbon fiber). The obtained results confirm the feasibility of the method and highlight the good performance of the developed system considered the radar resolution. In particular, the system is capable of discerning healthy coupons from damaged ones, and correctly reconstruct the reflectivity image of the tested defects, namely a 8 x 8 mm square bulge and a 5 mm drilled holes on metal specimen and a 5 mm drilled hole on composite coupon.

Advanced Non-Destructive Inspections focused on composite materials application for the automotive and marine sectors

The goal of this master thesis is to explain in detail the application of Non-Destructive-Inspection on the Automotive and the Marine sectors. Nowadays, these two particular industries faces many challenges, including increased global competition, the need for higher performance, a reduction in costs and tighter environmental and safety requirements. The materials used for these applications play key roles in overcoming these challenges. So, also an NDI procedure need to be planned in order to avoid problems during the manufacturing process and the after sale life of the structures. The entire thesis work has been done in collaboration with Vetorix Engineering.

Anomaly diagnosis in ceramic claddings by thermography - A review

With the increasing importance given to building rehabilitation comes the need to create simple, fast and non-destructive testing methods (NDT) to identify problems and for anomaly diagnosis. Ceramic tiles are one of the most typical kinds of exterior wall cladding in several countries; the earliest known examples are Egyptian dating from 4000 BC. This type of building facade coating, though being quite often used in due to its aesthetic and architectural characteristics, is one of the most complex that can be applied given the several parts from which it is composed; hence, it is also one of the most difficult to correctly diagnose with expeditious methods. The detachment of ceramic wall tiles is probably the most common and difficult to identify anomaly associated with this kind of cladding and it is also definitely the one that can compromise security the most. Thus, it is necessary to study a process of inspection more efficient and economic than the currently used which often consist in semi-destructive methods (the most common is the pull off test), that can only be used in a small part of the building at a time, allowing some assumptions of what can the rest of the cladding be like. Infrared thermography (IRT) is a NDT with a wide variety of applications in building inspection that is becoming commonly used to identify anomalies related with thermal variations in the inspected surfaces. Few authors have studied the application of IRT in anomalies associated with ceramic claddings claiming that the presence of air or water beneath the superficial layer will influence the heat transfer in a way that can be detected in both a qualitative and a quantitative way by the thermal camera, providing information about the state of the wall in a much broad area per trial than other methods commonly used nowadays. This article intends to present a review of the state of art of this NDT and its potentiality in becoming a more efficient way to diagnose anomalies in ceramic wall claddings.

Nondestructive testing techniques for titanium billets.

Mode of access: Internet.

ABOVE-GROUND BIOMASS ESTIMATION OF OPUNTIA FICUS-INDICA (L.) MILL. FOR FORAGE CROP IN A MEDITERRANEAN ENVIRONMENT BY USING NON-DESTRUCTIVE METHODS

In marginal lands Opuntia ficus-indica (OFI) could be used as an alternative fruit and forage crop. The plant vigour and the biomass production were evaluated in Portuguese germplasm (15 individuals from 16 ecotypes) by non-destructive methods, 2 years following planting in a marginal soil and dryland conditions. Two Italian cultivars (Gialla and Bianca) were included in the study for comparison purposes. The biomass production and the plant vigour were estimated by measuring the cladodes number and area, and the fresh (FW) and dry weight (DW) per plant. We selected linear models by using the biometric data from 60 cladodes to predict the cladode area, the FW and the DW per plant. Among ecotypes, significant differences were found in the studied biomass-related parameters and several homogeneous groups were established. Four Portuguese ecotypes had higher biomass production than the others, 3.20 Mg ha−1 on average, a value not significantly different to the improved ‘Gialla’ cultivar, which averaged 3.87 Mg ha−1. Those ecotypes could be used to start a breeding program and to deploy material for animal feeding and fruit production.

Time-frequency and time-scale analysis of Barkhausen noise signals

Carrying out information about the microstructure and stress behaviour of ferromagnetic steels, magnetic Barkhausen noise (MBN) has been used as a basis for effective non-destructive testing methods, opening new areas in industrial applications. One of the factors that determines the quality and reliability of the MBN analysis is the way information is extracted from the signal. Commonly, simple scalar parameters are used to characterize the information content, such as amplitude maxima and signal root mean square. This paper presents a new approach based on the time-frequency analysis. The experimental test case relates the use of MBN signals to characterize hardness gradients in a AISI4140 steel. To that purpose different time-frequency (TFR) and time-scale (TSR) representations such as the spectrogram, the Wigner-Ville distribution, the Capongram, the ARgram obtained from an AutoRegressive model, the scalogram, and the Mellingram obtained from a Mellin transform are assessed. It is shown that, due to nonstationary characteristics of the MBN, TFRs can provide a rich and new panorama of these signals. Extraction techniques of some time-frequency parameters are used to allow a diagnostic process. Comparison with results obtained by the classical method highlights the improvement on the diagnosis provided by the method proposed.

Erosion-fatigue of steam turbine blades

The premature failure of steam turbine rotor blades, manufactured in forged 12% Cr-NiMoV martensitic stainless steel, was investigated using visual inspection non-destructive testing, macro and microfractography, microstructural characterization, EDS microanalysis, chemical analysis, micro hardness and tensile testing. The blades belonged to the last stage of a thermoelectric plant steam turbine generator (140 MV A). The results indicated that the failure of the blades was promoted by foreign-particle erosion, which attacked preferentially the low-pressure side of the lower trailing edge of the blades. The resulting wear grooves acted as stress raisers and promoted the nucleation of fatigue cracks, which probably grew during the transition events of the steam turbine operation. Finally, water drop erosion was observed on the blade upper leading edge (low-pressure side). (C) 2009 Elsevier Ltd. All rights reserved.

Diagnóstico de estruturas de madeira em serviço num palacete do século XIX

Dissertação para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização em Edificações

Delamination analysis of carbon fibre reinforced laminates: evaluation of a special step drill

Drilling of carbon fibre/epoxy laminates is usually carried out using standard drills. However, it is necessary to adapt the processes and/or tooling as the risk of delamination, or other damages, is high. These problems can affect mechanical properties of produced parts, therefore, lower reliability. In this paper, four different drills – three commercial and a special step (prototype) – are compared in terms of thrust force during drilling and delamination. In order to evaluate damage, enhanced radiography is applied. The resulting images were then computational processed using a previously developed image processing and analysis platform. Results show that the prototype drill had encouraging results in terms of maximum thrust force and delamination reduction. Furthermore, it is possible to state that a correct choice of drill geometry, particularly the use of a pilot hole, a conservative cutting speed – 53 m/min – and a low feed rate – 0.025 mm/rev – can help to prevent delamination.

Diagnóstico e avaliação da segurança de estruturas de madeira existentes

A utilização da madeira enquanto material estrutural é um aspeto abordado com algum receio ou até desconhecimento por parte dos elementos intervenientes no processo de construção civil, sendo ainda uma área pouco lecionada e muitas vezes excluída dos planos curriculares em Engenharia Civil. Assim sendo é importante o surgimento de trabalhos relacionados com esta matéria, relembrando ao sector da construção civil e ao ramo de estudo relacionado, que a madeira já teve e possivelmente voltará a ter um papel importante a desempenhar na área da construção. Um dos aspetos evidenciados nos estudos realizados consiste na importância da reabilitação de edifícios e do seu papel cada vez mais determinante na sociedade. Esta metodologia de intervenção apresenta-se muitas vezes como uma vantagem económica assim como contribui para a preservação do património arquitetónico e cultural, cujo valor histórico é incalculável. A importância da reabilitação de edifícios habitacionais nas zonas históricas, bem como de monumentos de grande importância cultural apresenta-se cada vez mais como um desafio devido à falta de conservação dos mesmos ao longo da sua vida útil, e da necessidade de preservar a identidade do local, beneficiando assim a qualidade do tecido urbano. Assim sendo, este trabalho apresenta um levantamento dos danos possíveis de ocorrer em elementos de madeira, dando especial destaque aos agentes patológicos e às consequências da sua atividade na madeira assim como às metodologias de inspeção e diagnóstico que poderão ser aplicadas em estruturas de madeira existentes, favorecendo assim a vertente da reabilitação ao invés da demolição. Estas metodologias recorrem a ensaios não destrutivos, como é exemplo o Pilodyn, o Resistógrafo, o Ultra-sons, etc., referindo também o recurso a ensaios destrutivos, cuja utilização terá de ser uma questão muito bem ponderada devido às consequências que implica. Por fim, apresenta-se um caso real de estudo em que se analisa um pavimento em madeira através da aplicação de metodologias de ensaio não destrutivas e destrutivas a amostras recolhidas. O objetivo será determinar o estado de conservação da madeira e algumas características físicas tais como a sua densidade e os módulos de elasticidade, sendo posteriormente efetuada uma análise estrutural. Os resultados obtidos permitem efetuar uma avaliação qualitativa do estado geral do pavimento sendo as principais conclusões que o pavimento se encontra atacado por parte de insetos xilófagos e apresenta problemas a nível de verificação a estados limite de utilização, deformação e vibração, fator que condiciona a possível utilização do pavimento.