This Thesis focuses on the anthropogenic geomorphology in the vicinity of eight selected castles in the Bohemia region. The first part of study gathers information about already known archaeological features in the castle areas or hinterland. The first step of the survey uses LIDAR data combined with both historical and contemporary maps. Next, a surface survey helped to prove the existence of selected archaeological features, mark their location and get their written description and photographic documentation. Thanks to the information collected this way, we can possibly interpret former use of the features, as well as their origins in relation to the existence of the castle itself. The last part evaluates efficiency of the used method and reflects of the state of the examined castles areas and surroundings. Key-words: Medieval archaeology - Non-destructive methods - LIDAR - Castles - Anthropogenic landforms

A geological repository for spent nuclear fuel (SNF) and an associated encapsulation facility will be built in Sweden.  The encapsulation facility is planned to be in operation in 2025 and it will be the last place where verifying safeguards measurements of SNF can be performed. It is not clear what types of measurements that will be performed, because such requirements are not yet posed by national and international authorities and inspecting organizations. This report describes the objective and most recent results of a master thesis project, whereby a few existing non-destructive assay techniques for verifying SNF are selected for a review. The study focuses on the verifying ability of different techniques, or system of techniques in relation to the requirement that may be put on the future encapsulation plant. In addition, possible needs for future simulations and measurements are discussed. The work is done as a collaboration between Uppsala University in Sweden and Los Alamos National Laboratory in the USA.

The need for reliable and cost-effective testing procedures for Additive Manufacturing (AM) is growing. In this Dissertation, the development of a new computational-experimental method based on the realization of specific testing artifacts to address this need is presented. This research is focused on one of the widely utilized AM technologies, Fused Deposition Modeling (FDM), and can be extended to other AM technologies as well. In this method, testing artifacts are designed with simplified boundary conditions and computational domains that minimize uncertainties in the analyses. Testing artifacts are a combination of thin and thick cantilever structures, which allow measurement of natural frequencies, mode shapes, and dimensions as well as distortions and deformations. We apply Optical Non-Destructive Testing (ONDT) together with computational methods on the testing artifacts to predict their natural frequencies, thermal flow, mechanical properties, and distortions as a function of 3D printing parameters. The complementary application of experiments and simulations on 3D printed testing artifacts allows us to systematically investigate the density, porosity, moduli of elasticity, and Poisson’s ratios for both isotropic and orthotropic material properties to better understand relationships between these characteristics and the selected printing parameters. The method can also be adapted for distortions and residual stresses analyses. We optimally collect data using a design of experiments technique that is based on regression models, which yields statistically significant data with a reduced number of iterations. Analyses of variance of these data highlight the complexity and multifaceted effects of different process parameters and their influences on 3D printed part performance. We learned that the layer thickness is the most significant parameter that drives both density and elastic moduli. We also observed and defined the interactions among density, elastic moduli, and Poisson’s ratios with printing speed, extruder temperature, fan speed, bed temperature, and layer thickness quantitatively. This Dissertation also shows that by effectively combining ONDT and computational methods, it is possible to achieve greater understanding of the multiphysics that governs FDM. Such understanding can be used to estimate the physical and mechanical properties of 3D printed components, deliver part with improved quality, and minimize distortions and/or residual stresses to help realize functional components.

Dagens forskningsprojekt kräver minst lika mycket metodik och styrning som andra projekt, men studier av hur man driver och leder forskningsprojekt är fortfarande väldigt få. Syftet med den här uppsatsen har varit att utforska forskningsprojektet som arketyp och genom tio kvalitativa intervjuer få insikt om hur individer upplever att arbeta med forskningsprojekt.  Den här studien kommer visa på en del av den problematik som finns inom den akademiska naturvetenskapliga forskningen. En av den är att individens framgång dominerar över gruppens, vilket gör det svårt att samarbeta och bidrar till konkurrens mellan kollegor.  En del av den här studien berör psykosocial arbetsmiljö och ledarskap. Forskare tenderar till att arbeta oändliga timmar och har generellt svårt att sätta upp gränser för att ta vara på fritid och familj, något som kan leda till utbrändhet. Den osäkra miljön, konkurrensen och ambitionerna som finns kan leda till att destruktiva ledarskap får fotfäste. Alla de faktorer i kombination med att forskaren nästan uteslutande drivs av inre motivation, eftersom den yttre återkopplingen sällan finns, drabbas många av en känsla av otillräcklighet och bristande självförtroende. / Today's research projects require at least as much methodology and management as other projects, but studies on how to run and manage research projects are still very few. The purpose of this study has been to explore the research project as an archetype and through ten qualitative interviews gain insight into how individuals experience working with research projects.  This study will highlight some of the problems that exist in academic scientific research. One of them is that the success of the individual dominates over that of the group, making it difficult to collaborate and contributing to competition between colleagues.  Part of this study concerns the psychosocial work environment and leadership. Researchers tend to work endless hours and generally find it difficult to set boundaries to allow for leisure and family time, which can lead to burnout. The precarious environment, competition and ambitions that exist can lead to destructive leadership taking root. All of these factors, combined with the fact that the researcher is driven almost exclusively by internal motivation with little external feedback, leave many suffering from a sense of inadequacy and lack of self-confidence.

La simulation opérationnelle a déjà été développée pour diverses activités dont l'exercice en conditions réelles peut s'avérer coûteux voire dangereux : le pilotage d'avion, les interventions chirurgicales, etc. L'idée consiste à remplacer la réalité par une simulation suffisamment réaliste pour donner l'impression aux utilisateurs qu'ils réalisent réellement l'activité.Le Contrôle Non-Destructif (CND) regroupe l'ensemble des méthodes mises en œuvre pour tester l'intégrité des pièces mécaniques sans les altérer. Dans ce domaine, la simulation opérationnelle n'a été introduite que très récemment par un brevet déposé par Airbus. Cette approche permet de simuler numériquement la présence de défauts sans avoir à les ajouter réellement dans les pièces. Les pièces aéronautiques étant coûteuses, la simulation opérationnelle permet de réduire les coûts liés à la formation des opérateurs, à l'évaluation des performances des méthodes ou aux tests en conditions réelles de nouvelles procédures.La présente thèse vise à développer les outils scientifiques et technologiques nécessaires à donner vie au concept de simulation opérationnelle en CND. Pour remplacer la réalité par la simulation, les défis à relever sont de trois ordres : le réalisme de la simulation, la rapidité des calculs et l'instrumentation. Nous avons choisi d'illustrer ces trois aspects dans le cadre de l'inspection par ultrasons de pièces en matériaux composites. Les modèles de simulation couramment employés --- basés sur la résolution des équations de la physique --- n'offrent pas des temps de calculs suffisamment courts pour satisfaire les pré-requis de la simulation opérationnelle. Par ailleurs, le réalisme des simulations souffre parfois de la difficulté à paramétrer correctement les modèles. Nous explorons donc une autre approche : les modèles sont construits à partir de données expérimentales. Cette stratégie est exploitée pour traiter différents types de phénomènes tels que l'endommagement par impact, le trou à fond plat ou encore les perturbations de la micro-structure des matériaux. Par ailleurs, une solution matérielle et logicielle sont proposées et un premier prototype de simulateur opérationnel est mis au point. Ce système permet d'exploiter les modèles développés et de montrer que les signaux synthétiques peuvent sembler aussi réalistes que la réalité. Cette thèse court ainsi du concept jusqu'au prototype. / Several fields have already adopted the concept of operational simulation to limit risks and costs. For instance, part of the training phase of airline transport pilots or surgerons can now rely on simulations instead of real-life situations.Non-Destructive Testing (NDT) assesses the integrity of structural and mechanical components without damaging them. Operational simulation has drawn attention of the NDT community only recently through an Airbus patent. In this field, the operational simulation can be used to simulate the presence of a defect in a component without actually inserting the defect. For expensive parts such as aeronautical structures, this approach can reduce the costs of training operators, evaluating NDT method performances or testing new procedures in real-conditions.This thesis work aims to apply the concept of operational simulation to NDT. Three main scientific and technological challenges are to be tackled: the simulation realism, the computation speed and the instrumentation. We chose to focus this study on the ultrasound NDT technique applied to composite materials. Classical simulation approaches based on physical equations are not fast enough for a real-time synthesis of ultrasound signals. Moreover, the realism is often limited by the fidelity of the inspection set-up description. For instance, the material properties are not always well-known and bring to a drop of realism. Thus, we investigate an alternative way: the models are built directly from experimental data. This strategy is applied to model the effect of several phenomena such as impact damages, flat bottom holes or material micro-structure. Hardware and software solutions are also studied to propose a first prototype. We have shown that the replacement of real signals by on-the-fly simulated ones is achievable: the simulation is realistic enough to be considered as reality by operators. thus, this thesis work brings the concept to a first prototype dedicated to ultrasound NDT.

The loss of 6 million U.S. manufacturing jobs since 2000 has severely affected communities that have lost a vital source of employment. Voluntary employee turnover has compounded the problem. The purpose of this correlational study was to examine the relationship between employee turnover and destructive leadership behaviors of managers in small and medium enterprise (SME) manufacturing businesses in Warren County, New Jersey. The constructive-destructive leadership model formed the theoretical framework for the study. A random sample of 96 SME manufacturing firm employees completed the destructive leadership scale (DLS), multifactor leadership questionnaire (MLQ), and the turnover intention scale (TIS-6) via an online survey. Multiple linear regression analyses and Pearson-product correlation coefficients were used to predict employee turnover. Tyrannical leadership and laissez-faire leadership were the only significant contributors to the regression model. Implications for social change include providing business managers with information needed to maintain or increase employee retention levels, which may improve employee morale, increase job satisfaction, and enhance customer satisfaction in the communities served.

De nombreuses structures utilisées industriellement peuvent être considérées comme des guides d'ondes, comme les plaques, les tuyaux ou encore le rails. La maintenance de ces structures nécessite de pouvoir détecter efficacement des défauts internes par le Contrôle Non Destructif. Nous nous intéressons dans ce manuscrit à l'application d'une méthode d'échantillonnage, la Linear Sampling Method, au CND des guides d'ondes élastiques, qui en particulier impose des sollicitations et des mesures à la surface du guide en régime temporel. La stratégie choisie repose sur une formulation modale et multi-fréquentielle de la LSM, spécifique aux guides d'ondes, qui permet une régularisation efficace et de nature physique du problème inverse, qui est par nature mal posé. Cette stratégie permet par ailleurs une optimisation du nombre et de la position des émetteurs et des récepteurs. Nous nous limitons dans un premier temps au cas scalaire du guide d'ondes acoustiques, pour ensuite s'attaquer au cas vectoriel, et par conséquent plus complexe, du guide d'ondes élastiques.L'efficacité de la méthode inverse est dans un premier temps démontrée sur des données artificielles (obtenues numériquement), puis sur des données réelles obtenues à l'aide d'expériences réalisées sur des plaques métalliques. Ces expériences confirment la faisabilité du CND par méthode d'échantillonnage dans un cadre industriel. Dans le cas où une seule sollicitation est réalisée, l'utilisation de la LSM est exclu. Nous utilisons une approche tout à fait différente et dite "extérieure", couplant une formulation mixte de quasi-réversibilité et une méthode de lignes de niveau, pour reconstruire le défaut. / Widely used structures in an industrial context, such as plates, pipes or rails, can be considered as waveguides. Hence efficient Non Destructive Testing techniques are needed in order to detect defects in these structure during their maintenance. This work is about adapting a sampling method, the Linear Sampling Method, to the context of NDT for elastic waveguides. This context implies that the sollicitations and measurements must be on the surface of the waveguide in a time-dependent regime. A modal and multi-frequency formulation of the LSM, specific to waveguides, has been chosen to solve the problem. This formulation allows an efficient and physical regularization of the inverse problem, which is naturally ill-posed. An optimization of the number of sources and measurements and of their positioning is possible thanks to the methodology used to solve the problem. The scalar case of an acoustic waveguide is considered as a first step, while the vectorial case of an elastic waveguide, more complex by nature, is addressed in a second time.The efficiency of the method is at first tested on artificial data (numerically made), and then on real data obtained from experiments on metallic plates. These experiments show the feasibility of using sampling methods for Non Destructive Testing in an industrial context. In the case when only one sollicitation is available, the LSM can not be applied. A completely different approach is then used, which is called the ``exterior'' approach, coupling a mixed formulation of quasi-reversibility and a level-set method in order to recover the shape of the defect.

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第17918号 / エネ博第290号 / 新制||エネ||60(附属図書館) / 30738 / 京都大学大学院エネルギー科学研究科エネルギー応用科学専攻 / (主査)教授 大垣 英明, 教授 白井 康之, 教授 松田 一成 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DGAM

The use of ultrasound contrast agents increases the information available for reconstruction during ultrasound imaging. Previously studied microbubbles, consisting of a gas core, are subject to limitations such as a short lifetime and a large size. Droplets with a liquid perfluorocarbon core that is stabilized by cellulose nanofibers eliminate these drawbacks, but require further investigation. By studying the frequency-dependent attenuation profile of the cellulose nanofiber coated perfluorocarbon droplets within an ultrasound field, information about the droplets as oscillators can be retrieved, enabling characterization of their physical properties. In this study, the frequency-dependent attenuation profile was experimentally acquired and compared between two concentrations, using flat transducers covering the frequency range of 1-15 MHz. The data collected in the time domain was processed and transformed into the frequency domain and the attenuation was calculated across the entire frequency range. Among the frequencies studied, the attenuation increases with frequency and covers the range of approximately 0.25-8.3 dB/cm and 0.01-3.3 dB/cm at the concentrations of 50 million droplets/ml and 10 million droplets/ml respectively. The attenuation reaches a minimum at 3 MHz within the highest concentration, compared to 4.43 MHz within the lowest. The increase of the attenuation with frequency is explained by the droplets not exhibiting large oscillations within the range covered. It is probable that the droplets do exhibit oscillations, due to a viscosity lower than that of water, but a resonance frequency is not found within the spectrum studied. This could be explained by a shell elasticity or a small droplet radius placing the resonance frequency outside of the spectrum studied, or high levels of damping broadening the resonance peak. Localizing the resonance frequency would enable characterization of these physical properties of the cellulose nanofiber shell as well as the perfluorocarbon liquid core of the droplets. The increase of the attenuation with frequency demonstrates that the droplets do not produce a maximized amount of scattering at a specific frequency within the range studied, which is observed among other oscillating particles implemented as ultrasound contrast agents. The attenuation is, however, larger than that of blood across all frequencies except for those among which the attenuation reaches its minimum. Potential errors that are affecting the results include droplet vaporization, the formation of flocs after the mechanical agitation has ceased, the experimental setup, the settings on the pulse generator, the sensitivity of the transducers and the processing code.

Today, microbubbles are one of the most commonly used ultrasound contrast agents, since their high compressibility results in a strongly scattered signal. Despite this advantage, microbubbles experience limitations by the decreased stability and large diameter. The cellulose nanofiber (CNF) stabilized perfluoropentane (PFC5) droplets have the possibility of eliminating these drawbacks. In order to examine the droplet behavior and scattering ability when exposed to ultrasound, the acoustic response of the droplets is studied and compared with that of microbubbles (MBs). Therefore, this thesis aims to design an experimental set-up and a processing method to determine the phase velocity, bulk modulus and compressibility of the CNF-coated PFC5 droplets. The experimental study of the acoustic characterization uses pulse-echo spectroscopy with an aluminum reflector and seven flat transducers covering the frequency range 0.7 to 14.1 MHz. By using fast Fourier transform, while accounting for the 2πn ambiguity, the phase velocity profiles are obtained. The dispersions within this frequency spectrum are 1391-1487 m/s and 1387-1488 m/s for the concentrations 10 ∙ 106 and 50 ∙ 106 droplets/ml, respectively. These profiles display an increasing phase velocity with frequency and a slight increase in dispersion with concentration. These results agree with theory and studies examining the phase velocity of MBs. The bulk modulus presents values between 3-4 GPa, while the compressibility is 2.7 − 3.2 ∙ 10-10 𝑃𝑎-1 within the frequency range studied. Compared to water and certain MBs, both possessing a lower bulk modulus, the droplets are less compressible. To conclude, the droplets have similar phase velocity profiles with the same dependencies on frequency and concentration as MBs, resulting in similar behavior of these droplets when exposed to ultrasound. Hence, affecting the wave similarly to MBs in terms of spreading. The droplet are, however, not as compressible. This most likely affects their oscillation and they, hence, might not have equally beneficial scattering ability. This could reduce their utilization as contrast agents. Some of the potential error sources present during the laboratory work and the development of the post-processing code were not achieving perfect optimization of the transducer alignment, vaporization of the droplets resulting in reduced concentration, possible diffraction, not optimal processing of data and inadequate correction for 2πn ambiguity.