La méthode des courants de Foucault (CF) est très largement utilisée en milieu industriel pour l'évaluation non destructive (END) de pièces ou de structures électriquement conductrices, parce qu'elle est sensible, robuste peu couteuse et non polluante. Toutefois, dans le cas général, l'évaluation quantitative des paramètres caractéristiques d'une structure est un problème difficile, d'une part parce que les données CF disponibles sont généralement incomplètes, d'autre part parce qu'il est nécessaire de faire appel à des modèle numériques élaborés pour rendre compte des interactions sonde / structure, et enfin, parce que le problème inverse consistant à estimer les paramètres de la structure à partir de la connaissance des interactions physiques et des données CF disponibles est " mal posé ".Dans cette thèse, nous nous intéressons au problème particulier de l'évaluation de jeux entre pièces dans un assemblage métallique. Pour contourner les difficultés liées à la mise en oeuvre de l'évaluation quantitative par CF, nous avons choisi de placer nos travaux dans un cadre multifréquence afin d'enrichir les données d'observation fournies par la sonde, et d'adopter une démarche consistant à élaborer des modèles comportementaux issus de l'analyse statistique des interactions sonde / structure. Partant de l'analyse de l'effet d'un jeu apparaissant entre les plaques d'un assemblage de plaques d'aluminium sur la variation de l'impédance normalisée de la sonde, menée expérimentalement et par simulations à l'aide de codes éléments finis, nous avons tout d'abord bâti un modèle comportemental approché d'interactions reposant sur la linéarité de la relation observée dans une bande de fréquences d'examen liée aux dimensions de la structure étudiée. Dans ce cadre, nous avons proposé, implanté et discuté des performances de plusieurs algorithmes de résolution du problème inverse, permettant d'estimer le jeu entre pièces et l'épaisseur de la pièce " cachée " de l'assemblage. Ensuite, nous avons étendu l'approche proposée à l'aide de réseaux de neurones artificiels, puis appliqué la méthode comportementale proposée à un second problème : celui de la caractérisation de fissures de fatigue réelles dans des pièces massives. Les résultats obtenus inclinent à considérer que la démarche proposée est généralisable à d'autres configurations en END par CF.

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This study is an attempt to better understand the experience of self-destructive behaviour in First Nations adolescent girls by telling their stories, discussing factors that may contribute to the behaviours, and providing counselling insight. Not every Native girl experiences self-destructive behaviour, however those that do require more effective solutions to their problems. There is ample literature regarding non-Native girls and their experiences with self-destructive behaviour. This is not the case with Native girls, and this study is an attempt to fill the literature gap, and at the same time provide insight into counselling practice. Many factors may contribute to the experience of self-destructive behaviour in First Nations adolescent girls (e.g., gender, developmental stages, parenting, cultural norms and values, and discrimination). The combination of these issues compounds each other and creates the context for the experience of self-destructive behaviour specific to Native girls. This reality puts them at risk for truancy, juvenile delinquency, teen pregnancy, drug and alcohol abuse, depression, anxiety, eating disorders, self-harming, and ultimately suicide. In order to understand the circumstances or events that lead to a young Native woman's experience with self-destructive behaviour I interviewed three women using in-depth, semi structured interviews. When answering the open-ended questions I asked, the interviewees revealed a story with a beginning, middle, and end. This story reflected the different stages in their lives, childhood, adolescence, and eventually young adulthood. Analysis of the interviews through theme identification revealed common threads through each woman's life. Although each woman had unique experiences, their stories revealed many commonalties. These common themes reflect factors that counsellors should consider when counselling First Nations girls who are experiencing self-destructive behaviour. The results of the study suggest that counsellors should not isolate factors that lead to self-destructive behaviour. For example, First Nations girls experience not just racism or neglectful parenting — they experience both of the factors. The contributing factors begin early in life and compound one another as the girl's life progresses. Hopefully, this study contributes to the betterment of individual Native girls, also to the betterment of the families' and communities' health.

Kompozicinių medžiagų konstrukcijų taikymas aviacijoje didėja. Saugumui aviacijoje užtikrinti reikalingos patikimos kontrolės sistemos. Šiame darbe pateiktas ultragarso greičio matavimo metodo taikymas kompozicinėms struktūroms tirti. Metodas numato akustinių gardelių panaudojimą, sudarant ultragarso bangų sklidimo greičio matavimo kanalą tiriamame sluoksnyje. Šis metodas atitinka keliamus tikslumo, patikimumo ir operatyvumo reikalavimus. Darbo apimtis – 65 p. teksto be priedų, 44 iliustr., 3 lent., 16 bibliografiniai šaltiniai. / Usage of compositional materials in aviation increases. To ensure safety in aviation - reliable control systems are required. Method of examination of compositional materials using ultrasound measuring system is introduced in this work. This method implies usage of acoustic lattice for measurement of created ultrasound waves in examined layer. This method complies with requirements for accuracy, reliability and effectiveness.

Mechanical waves provide information about the stiffness and the condition of a medium; thus, changes in medium conditions can be inferred from changes in wave velocity and attenuation. Non-destructive testing (NDT) methods based on ultrasonic waves are often more economical, practical and faster than destructive testing. Multichannel analysis of surface waves (MASW) is a well-established surface wave method used for determination of the shear-wave profile of layered medium. The MASW test configuration is also applicable to assess the condition of concrete elements using appropriate frequency range. Both attenuation and dispersion of ultrasonic waves can be evaluated by this technique. In ultrasonic testing, the characterization of a medium requires the precise measurement of its response to ultrasonic pulses to infer the presence of defects and boundary conditions. However, any ultrasonic transducer attached to a surface affects the measured response; especially at high frequencies. On the other hand, ultrasonic transducers available for engineering application are mostly used to measure wave velocities (travel time method). Therefore, these transducers do not have a flat response in the required frequency range. Moreover, in the case of full-waveform methods, the recorded signals should be normalized with respect to the transfer functions of the transducers to obtain the real response of the tested specimen. The main objective of this research is to establish a comprehensive methodology based on surface wave characteristics (velocity, attenuation and dispersion) for condition assessment of cemented materials with irregular defects. To achieve the major objective, the MASW test configuration is implemented in the ultrasonic frequency range. The measured signals are subjected to various signal processing techniques to extract accurate information. In addition, a calibration procedure is conducted to determine the frequency response functions (FRF) of the piezoelectric accelerometers outside their nominal frequency range. This calibration is performed using a high-frequency laser vibrometer. This research includes three main studies. The first study introduces the calibration approach to measure the FRFs of the accelerometers outside of their flat frequency range. The calibrated accelerometers are then used to perform MASW tests on a cemented-sand medium. The original signals and the corrected ones by eliminating the effect of the FRFs are used to determine material damping of the medium. Although, the damping ratios obtained from different accelerometers are not same, the values from the corrected signals are found closer to the characteristic damping value compared to those from the uncorrected signals. The second study investigates the sensitivity of Rayleigh wave velocity, attenuation coefficient, material damping and dispersion in phase velocity to evaluate the sensitivity of these characteristics to the damage quantity in a medium. The soft cemented-sand medium is preferred as the test specimen so that well-defined shaped defects could be created in the medium. MASW test configuration is implemented on the medium for different cases of defect depth. The recorded signals are processed using different signal processing techniques including Fourier and wavelet transforms and empirical mode decomposition to determine the surface wave characteristics accurately. A new index, ‘dispersion index’, is introduced which quantifies the defect based on the dispersive behaviour. All surface wave characteristics are found capable of reflecting the damage quantity of the test medium at different sensitivity levels. In the final study, the condition assessment of six lab-scale concrete beams with different void percent is performed. The beam specimens involving Styrofoam pellets with different ratios are tested under ultrasonic and mechanical equipment. The assessment produce established in the second study with well-defined defects is pursed for the beams with irregular defects. Among the characteristics, attenuation, P and R-wave velocities and dispersion index are found as the promising characteristics for quantifying the defect volume.

A Barkhausen noise (BN) testing system was developed for the non-destructive evaluation (NDE) of residual stresses in CANDU reactor feeder pipes. The system consists of a four-channel arbitrary waveform flux control system (FCS), and the spring-loaded tetrapole prototype (SL4P) BN probe. The combination of the FCS and SL4P was shown to provide repeatable BN measurements on feeder pipe samples, with variations in air gaps between the SL4P poles and the sample from 0.43 mm to 1.29 mm, and typical pickup coil coupling uncertainties for the total BN energy from ±2% to ±7%. Precision for elastic strain estimation in feeder pipes was found to be between ±7 MPa and ±9 MPa in tension, depending on the excitation field configuration, and negligible in compression. Modelling of the BN penetration depth as a function of the excitation field was used to estimate the BN penetration depth between 5 μm at 300 kHz to a maximum of 500 μm at 3 kHz. The modelling, engineering, and procedures developed for this BN testing system provide an improved basis for the future advancement of BN testing, and ferromagnetic NDE in general. / Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2009-07-22 15:34:28.967

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Firefighters’ coats and pants, referred to as firefighters’ protective clothing in this research, are made of similar fabrics and often include three layers: an outer shell, a moisture barrier, and a thermal liner. Minimum requirements of firefighters’ protective clothing performance have been clearly established by various national and international standards for new clothing to ensure the reasonable safety of firefighters. However, there are no clear guidelines on the requirements for continuing performance of firefighters’ protective clothing. In general, the protection offered by firefighters’ protective clothing is expected to deteriorate over time, but it is still uncertain how destructive different exposures are and how long a piece of firefighters’ protective clothing can continue to protect a firefighter to an acceptable level. Non-destructive techniques are preferable in order to investigate how the performance of protective clothing may change with time since this allows firefighters’ protective clothing to return to service after a test. These non-destructive methods, which could be used to monitor the level of deterioration in firefighters’ protective clothing performance and to make decisions on retirement of individual pieces of protective clothing, would be extremely useful for fire departments in Canada and other countries. Thermal exposure is an important factor in ageing of firefighters’ protective clothing during firefighting operations. Outer shell and moisture barrier specimens made of common fabrics used in construction of firefighters’ protective clothing, and of different colours, were exposed to different levels of thermal exposure simulated using a cone calorimeter in single and multiple stages. Tensile strength of outer shell specimens, and tear strength, water vapour transmission rate, and water penetration pressure of moisture barrier specimens, which are critical aspects of performance of firefighters’ protective clothing, were measured. In order to explain the changes in performance after thermal exposure, the temperature profile of specimens during each thermal exposure was recorded. Furthermore, thermogravimetric analysis for each specimen material was carried out and images of the surface of specimens were obtained using scanning electron microscope. The test results demonstrated that tensile strength of outer shell specimens deteriorated faster than other aspects of performance. Two non-destructive techniques, colour measurement and near infrared spectroscopy, were implemented to correlate tensile strength of outer shell specimens with discoloration and reflectance spectrum. Two types of correlation between tensile strength and colour change were identified among the tested fabrics, depending on the initial fabric colour, which could be a basis to develop numerical models to predict tensile strength of outer shell specimens. Linear predictive equations were developed using a numerical code based on regression analysis, which correlated tensile strength with reflectance of outer shell specimens within the wavelength region of 1500-2500 nm. A three-variable model predicted tensile strength of thermally aged test specimens, the tensile strength of which were 600 N and higher, with a relative error of up to 10%. For test specimens with tensile strength of about 300 N, the relative error was 55%. The difference in error percentage was related to a gap in training data points for the model within the tensile strength range of 300 - 600 N.

This research investigates the paradox that many coastal communities in developing countries are resource rich but income poor. Another aspect of this paradox is the belief that local communities possess traditional knowledge that respects nature. This belief contrasts the fact that major tropical coastal ecosystems, namely coral reefs and mangroves, are being destroyed at rapid and increasing rates, in many cases by the people whose livelihoods depend on them. These paradoxical circumstances lead to a central question: if the sustainability of coastal resources is vital for the livelihood of local communities, why are these resources being degraded, often to the point of complete destruction? This study explores the motives and consequences of destructive methods of coastal resource utilisation and examines the potential for sustainable livelihoods based on coastal resources currently under threat from destructive use patterns. The analysis is based on a field study conducted in 2006 and 2008 in eleven sites around the island of Sulawesi, Indonesia. This area is characterised by great biodiversity, including one of the highest marine biodiversities in the Asia-Pacific region. Coral and mangrove ecosystem resource use was found to be driven by different processes and activities; hence the destructive practices impacting both ecosystems were also different. Blast and poison fishing were the most widespread destructive resource use methods found for coral reefs whereas large-scale habitat conversion was responsible for mangrove ecosystem reduction. In the field both resources were found to be under enormous anthropogenic pressures, with published data suggesting that only 5.8% of Indonesian coral reefs are currently in excellent condition and only 38% of mangrove cover remaining in Sulawesi relative to that of 25 years ago. The dynamics of these coastal resources, and of their destruction, are classic examples of the ’tragedy of the commons’. Research findings further indicate that formal institutions tasked with managing these resources have not been able to promote their effective conservation. An array of competing demands and conflicting interests, coupled with inefficient institutional arrangements and under-investment, have rendered inadequate many resource management efforts, including the externally-imposed concepts, allowing destructive patterns of resource utilization to persist. Local communities are disempowered when confronted with (1) the intricate network of destructive-fishing actors targeting coral reefs, or (2) large company-government bureaucracy collusions allowing mangrove conversion. The existence of this collusive network must be considered in any effort to address problems of effective management. Empirical insights suggest that conservation at local level has to face the challenges of market-driven resource extraction at a global scale. Only when a coastal community manages to overcome the dilemma in managing common-pool resource, conservation measures can be implemented and a degree of sustainability attained. Findings from this research have important implications for the discourses on coastal resource policy and research. This research advances the discussions to the area where the core of conflict of interests among stakeholders took place, and yet has rarely been addressed previously. The synthesis from this study provides a strong basis to understand the nature of asymmetric relations amongst the resource stakeholders, and therefore will help in generating effective policies for a fairer coastal resource management regime.

Målet med dette arbeidet er å få kunnskaper om lederes mobbing, relatere det til konseptet destruktiv ledelse, og undersøke hvilken betydning makt og verdier kan ha i denne prosessen. Hensikten er å bruke kunnskapen til å bekjempe mobbing. Metode: Dette er en litteraturstudie med et systemteoretisk perspektiv. Mobbingen blir sett på som en dynamisk prosess med interaksjon mellom lederen som mobber, mobbeofferet, arbeidsgruppen og organisasjonen, hvor de alle inngår i et flerdimensjonalt system. Det er lagt stor vekt på å presisere begrepene. Resultater: Det er funnetgode holdepunkter for å hevde at ledere som mobber utøveren meget skadelig form for ledelse. I denne prosessen som har en tendens til å eskalere over tid, spiller makt og verdier en viktig rolle. Ledere med en psykopatisk personlighet kan praktisere ledelse på en måte som får store negative konsekvenser for organisasjonen og de ansatte, og slike personer har en tendens til å misbruke makt. De kan likevel bli ansatt som ledere fordi de har egenskaper som organisasjonen søker og setter pris på. Det er ikke enighet om at mobbing er en uetisk handling. Litteraturen viser at enkelte ledere bruker mobbing strategisk for å oppnå egne fordeler, eller for kontrollere eller straffe de ansatte. Mobbing kan inngå i en bevisst ”organisasjonspolitikk” som blir aksepterti visse organisasjoner. Bedriftsetikk ser i mange sammenhenger ut til å være et begrep uten forpliktende innhold. Det er undersøkt hvordan begrepene managementideologi, instrumentell rasjonalitet og paradokser kan påvirkelederes mobbing. Managementideologien som gjennomsyrer synet på ledelse i store deler av samfunnet, i offentlige organisasjoner i form av New Public Management, er preget av instrumentelle verdier og en utilitaristisk etikk. Dette kan stå i motsetning til den grunnleggende respekt for mennesket som er et fundament i Emmanuel Kants etikk. Konklusjon:Studiet viser atlederes mobbingav ansatte er et meget utbredt og alvorlig problem som er svært ødeleggende for personer og organisasjoner. Det er dermed et betydelig folkehelseproblem. / Objectives: This study aimed to gain insight into the process of leaders bullying their subordinates, relate it to the concept of destructive leadership, and examinethe role of power and values in this process. The overall aim was to provide knowledge about how toreduce bullying. Method: This literature study looked at workplace bullying from the perspective of systems theory. Bullying is seen as a dynamic process characterized by interactions between the perpetrator, the victim, the workgroup, and the organization. The author has given priority toprecision of concept definitions. Results: The literature suggests that leaders who bully practicea very destructive form of leadership. Powerand values play an important rolein the bullying process, which tends to escalate over time.Leaders with a psychopathic personality practicea leadership style that may have serious negative consequences for the organization and its employees. Although psychopathic leaders often misuse power they may retain their leadership role because they seem to have personality traits the organization seeks and appreciates. Interestingly, the author found no agreement about bullying being an immoral act. The literature shows that some leaders use bullying strategically for personal gain or to control or punish employees. Bullying may be part of the organization politics accepted by some organizations,and business ethics often sees to be a concept without areal obligation. An overview discusse show the concepts of management ideology, instrumental rationality and paradoxes may affect leaders ́bullying and harassment. Instrumental values and utilitarian ethics dominate the management ideology that strongly influences leadership in a large part of society, and in public organizations such as New Public Management.This is often in opposition to the fundamental respect for the person that is central to the ethics of Emmanuel Kant. Conclusions: This study shows thatorganization leaders who bully their subordinates representa large and serious problem, with very destructive consequences for persons and organizations. Bullying is thus an important public health problem / <p>ISBN 978-91-86739-83-6</p>