An increment borer is the primary tool used to collect samples for dendrochronological analyses. These are precision instruments and users should be trained in their proper use, care, and maintenance. In this paper, I describe the various parts of an increment borer and how to keep these in working condition. I provide details on how to sharpen an increment borer, properly core a tree, check for core compression ("jamming"), extract the core, and store the core for transport. I provide tips on how to clear a jammed borer and remove a borer stuck in a tree. An important topic concerns the effects of boring on trees. The majority of studies indicate that conifers are minimally affected by both fungal decay and discoloration, whereas certain hardwood species can sustain major internal damage. Plugging the holes created by coring is unnecessary.

In this thesis, four inversion problems of different scale and difficulty are solved. Two of them are electromagnetic inverse problems. Two more are joint inversion problems of potential field data and other types of data. First, a linear approximation, which is a generalization of the low-induction-number approximation standard in slingram dual-loop interpretation is developed and used for rapid two and three dimensional inversion. The approximation takes induction within a background half-space into account and can thus be applied in conductive scenarios, where otherwise a rigorous electromagnetic modeling would be required. Second, a three-dimensional inversion of airborne tensor very-low-frequency data with a rigorous forward modeling at its core is developed. For dealing with the large scale of the forward problem, a nested fast-Fourier-transform-based integral equation method is introduced, wherein electromagnetic interactions are arranged according to their range and larger ranges are treated with less accuracy and effort. The inversion improves the traditional interpretation through data derived maps by providing a conductivity model, thus constraining the upper few hundred meters of the crust down to the shallowest conductor and allowing the study of its top in three dimensions. The third inversion problem is the the joint inversion of refraction and geoelectric data. By requiring the velocity and resistivity models to share a common, laterally variable layered geometry, easily interpretable models, which are reasonable in many geological near surface situations (e.g., groundwater exploration in Quaternary sediments), are produced directly from the joint inversion. Finally, a joint inversion of large scale potential field data from a gabbro intrusion is presented. Gravity and magnetic data are required to abide to a petrophysical constraint, which is derived from extensive field sampling. The impact of the constraint is maximized under the provision that both data sets are explained equally well as they would be through individual inversions. This leads to a simple and clearly defined intrusion geometry, consistent for both the density and magnetic susceptibility distribution. In all presented inversion problems, field data sets are successfully inverted, the results are appraised through synthetic tests and, if available, through comparison with independent data. / Diese Arbeit hat die Lösung von vier geophysikalischen Umkehraufgaben, sogenannten Inversionsproblemen, zum Gegenstand. Zwei dieser Aufgaben befassen sich mit der Inversion elektromagnetischer Daten, zwei weitere sind Probleme der kombinierten Inversion von Datensätzen aus unterschiedlichen geophysikalischen Messverfahren. Im ersten Problem wird die für die Auswertung elektromagnetischer Zweispulensystemdaten typische lineare Näherung der kleinen Induktionszahlen als Bornsche Näherung verallgemeinert, ihre Anwendbarkeit durch exakte Berücksichtigung der Induktionsvorgänge in einem beliebigen homogenen Halbraum von schlechtleitenden auf gutleitende Untergründe ausgedehnt und schließlich zur zwei- und dreidimensionalen Inversion eingesetzt. Dadurch kann auch im leitfähigen Untergrund eine aufwändige exakte Modellierung vermieden werden. Im zweiten Problem wird eine dreidimensionale Inversion von flugzeuggestützten Längstwellenmessungen entwickelt und als ihre Grundlage eine exakte elektromagnetische Rechnung erdacht. Damit wird traditionelle kartengestützte Dateninterpretation durch ein dreidimensionales Leitfähigkeitsmodell ergänzt, welches die oberen hundert bis dreihundert Meter der Erdkruste bis hin zur Tiefe des obersten Leiters abbildet, so dass dessen Oberflächenform erkundet werden kann. Die enorme Problemgröße wird durch eine Fouriertransformationsmethode bewältigt, welche die elektromagnetischen Wechselwirkungen nach ihrer Reichweite einteilt, die Fernwirkungen mit entsprechend verringerter Genauigkeit behandelt und dadurch eine erhebliche Anzahl an Rechnungen einspart. Im dritten Problem werden refraktionsseismische und geoelektrische Messungen kombiniert, indem sowohl das Geschwindigkeits- als auch das Widerstandsmodell mit einer gemeinsamen, lateral veränderlichen und durch beide Datensätze bestimmten Schichtstruktur versehen werden. Ein solches, durch Schichten definiertes Inversionsergebnis, stellt in vielen oberflächennahen Anwendungen, beispielsweise im Grundwasserbereich, ein sinnvolles Abbild der Erde dar. Im vierten Problem werden Schweremessungen und Magnetfeldmessungen, die über einer Gabbrointrusion aufgenommen wurden, mittels einer empirischen petrophysikalischen Beziehung vereinigt, welche aus Labormessungen an einer großen Anzahl von Gesteinsproben abgeleitet wurde. Hierbei wird der Einfluss dieser Modellkopplung solange maximiert, wie beide Datensätze mit derjenigen Genauigkeit angepasst werden können, welche vorher in Einzelinversionen erreicht wurde. Das Ergebnis ist ein einfaches, geometrisch konsistentes Modell der Verteilungen von Dichte und magnetischer Suszeptibilität. In allen vier Aufgaben wurden erfolgreich reale Felddaten invertiert. Die Güte der Ergebnisse wurde mittels synthetischer Experimente untersucht und, so vorhanden, mit unabhängigen Informationen verglichen.

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abstract: There has been a robust and ongoing investment in demystifying the discursive and material conditions of neoliberalism. Scholars in communication have done much work to explore the various rhetorical effects and processes of neoliberal discourses and practices. Many of these case studies have tethered their concerns of neoliberalism to the conceptualization of the public sphere. However, most of this research rests on the absence of those that try to “make do.” By privileging rhetoric after the fact, such studies tend to provide more agency to ideology than everyday bodies that engage in their own rhetorical judgments and discernments. In addition, scholarship across the board tends to treat neoliberalism as something dangerously and uniquely new. This framing effectively serves to ignore the longer history of liberalism and liberal thought that paved the path of neoliberalism the United States is now on. With these two broad concerns in mind, this study centers a case study of a charter school in South Phoenix to focus on the vernacular rhetorics of those on the ground. Guided by public sphere theory, critical race theory, and intersectionality, I take up rhetorical field methods to explore how those involved with this charter school navigate and make sense of school choice and charter schools in the age of neoliberalism. Within this context, field methods permit me to locate the various discourses, practices, and material constraints that shape running, being educated at, and selecting a charter school. These various rhetorical practices brought to the forefront an interest and concern with the school’s whole child approach as it is rooted within Stephen Covey’s (1989) seven habits. Additional qualitative data analysis brings about two new concepts of neoliberal scapegoating and dialectical vernacular complicity. Finally, I discuss the implications of these findings as they speak to how rhetorical field methods, supported by intersectionality and critical race theory, invites critics to center more agency on people rather than ideas, and how that makes for a more complicated and nuanced neoliberal reality and modes of resistance. / Dissertation/Thesis / Doctoral Dissertation Communication 2020

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In this thesis morphologies, coarsening mechanisms and kinetics are examined in a systematic way, when phase separation and subsequent microstructural coarsening is modelled using deterministic mean field and stochastic Monte Carlo methods. For the mean field approach a microscopic diffusion equation due to Khachaturyan is employed, and a variation of it with an environment dependent mobility. Monte Carlo simulations are carried out with vacancy and Kawasaki dynamics, and a residence time algorithm is applied in the vacancy case. In mean field models microstructural evolution results from a direct minimization of a free energy functional, and the mechanism of atomic diffusion does not appear explicitly. In Monte Carlo models, changes in site occupancies are effected by direct exchanges of neighbouring atoms (Kawasaki dynamics), or through vacancy motion. In this thesis the correspondence between mean field and Monte Carlo models in describing phase transformations in binary alloys is examined. Several examples of cases in which these differences between deterministic and stochastic models affect the phase transformation are given, and the underlying differences are analyzed. It is also investigated how the choice of diffusion mechanism in the Monte Carlo model affects the microstructural evolution. Most Monte Carlo studies have been carried out with Kawasaki dynamics, although in real metals such direct exchanges are very unlikely to occur. It will be shown how the vacancy diffusion mechanism produces a variety of coarsening mechanisms over a range of temperatures, which the Kawasaki dynamics fails to capture. Consequently, kinetics and resulting morphologies, especially at low temperatures, are affected. Finally, the question of physicality of time scales in mean field and Monte Carlo models is addressed. Often a linear dependence between Monte Carlo time and real physical time is assumed, although there is no rigorous justifcation for this. In mean field models, time is defined through the atomic mobility. By examining the effect of a realistic diffusion mechanism in systems undergoing phase transformation, a critical discussion of time scales in microscopic mean field models and a Monte Carlo model with Kawasaki dynamics is presented.

Cette thèse s'inscrit dans le cadre du projet Cart-O-Matic mis en place pour participer au défi CAROTTE (CArtographie par ROboT d'un TErritoire) organisé par l'ANR et la DGA. Le but de ce défi est de construire une carte en deux et trois dimensions et de localiser des objets dans un environnement inconnu statique de type appartement. Dans ce contexte, l'utilisation de plusieurs robots est avantageuse car elle permet d'augmenter l'efficacité en temps de la couverture. Cependant, comme nous le montrons, le gain est conditionné par le niveau de coopération entre les robots. Nous proposons une stratégie de coopération pour une cartographie multirobot efficace. Une difficulté est la construction d'une carte commune, nécessaire, afin que chaque robot puisse connaître les zones de l'environnement encore inexplorées. Pour obtenir une bonne coopération avec un algorithme simple nous proposons une technique de déploiement fondée sur le choix d'une cible par chaque robot. L'algorithme proposé cherche à distribuer les robots vers différentes directions. Il est fondé sur le calcul partiel de champs de potentiels permettant à chaque robot de calculer efficacement son prochain objectif. En complément de ces contributions théoriques, nous décrivons le système robotique complet mis en oeuvre au sein de l'équipe Cart-O-Matic ayant permis de remporter la dernière édition du défi CAROTTE / This thesis is part of Cart-O-Matic project set up to participate in the challenge CARROTE (mapping of a territory) organized by the ANR and the DGA. The purpose of this challenge is to build 2D and 3D maps of a static unknown 'apartment-like' environment. In this context, the use of several robots is advantageous because it increases the time efficiency to discover fully the environment. However, as we show, the gain is determined by the level of cooperation between robots. We propose a cooperation strategy for efficient multirobot mapping. A difficulty is the construction of a common map, necessary so that each robot can know the areas of the environment which remain unexplored.For a good cooperation with a simple algorithm we propose a deployment technique based on the choice of a target by each robot. The proposed algorithm tries to distribute the robots in different directions. It is based on calculation of the partial potential fields allowing each robot to compute efficiently its next target. In addition to these theoretical contributions, we describe the complete robotic system implemented in the Cart-O-Matic team that helped win the last edition of the CARROTE challenge

Cette étude propose d'examiner les vestiges archéologiques de Qasr ʿAllam enfouis sous les sédiments en développant une approche géophysique adaptée aux contextes du site. La mesure du champ total à l'aide de magnétomètres vectoriels à vanne de flux permet la mise au point de dispositifs multi-capteurs qui permettent une acquisition au rapport rapidité/densité hautement modulable. Ainsi des cartes verticales et horizontales de l'anomalie de l'intensité du champ magnétique à différentes échelles sont établies. L'utilisation et le développement d'outils d'interprétation issus de la théorie du potentiel, couplés à des fouilles ciblées, permettent à la fois de d'obtenir des informations sur les sources et d'améliorer la méthode grâce aux preuves-terrain. Les résultats ainsi obtenus révèlent la présence d'un système d'irrigation complexe et étendu, d'un ensemble cultuel massif du 8e/7e siècle avant l'ère commune et d'un second ensemble plus petit postérieur de plusieurs siècles. Entre ces deux derniers un changement environnemental brutal d'un milieu humide à aride a manifestement eu lieu. Tous ces résultats permettent d'établir des cartes des vestiges pour l'étude archéologique et l'établissement d'un périmètre de protection du site. / This study proposes to investigate the archaeological remains covered by sediments in Qasr ʿAllam by developing a geophysical method adapted to the contexts of the site. The measurement of the magnetic total field with fluxgate vector magnetometers allows the design of multi-captor devices which enable an acquisition of data with a highly adjustable rapidity/density ratio. Thus, vertical and horizontal maps of the anomaly of the magnetic total field's intensity are established. The use and development of interpretative tools derived from the theory of potential fields in association with targeted excavations allow the procurement of information on the sources as well as the improvement of the method through field evidences. The results reveal the existence of a large and intricate irrigation system, of a massive cultic facility dating from the 8th/7th century before the Common Era, and of a smaller complex built a few centuries later. Evidences also show that a massive change from humid to arid environmental conditions took place during the time separating the two latter. All these results allow the establishment of maps of the remains for archaeological studies and the establishment of a perimeter of protection of the site.

The term “isolated find” has frequently been taken as a disposable artifact category in cultural resource management (CRM). Efforts were made to empirically demonstrate the fallacy of this concept and its use, using modified field sampling strategies, the inclusion of fine screen artifact analysis, and statistical analyses. Six sites containing prehistoric occupations on Camp McCain National Guard base in Grenada County, Mississippi were reinvestigated using these methods; their datasets were expanded in terms of site size, density, function, and temporal association, which may change their eligibility status for the National Register of Historic Places (NRHP). Fieldwork and classification based solutions are offered to account for biases introduced by current standard methods of sampling and site delineation during Phase I archaeological survey.

Die Ladungsinjektion (-extraktion) an einer Schnittstelle spielt in der organischen Elektronik eine entscheidende Rolle, da sie die Leistung des Bauelements stark beeinflusst. Eine der effizientesten Methoden zur Optimierung der Energiebarrieren für die Injektion ist die Modifikation der Austrittsarbeit der Elektroden. In dieser Dissertation untersuchen wir die Modifikation der Austrittsarbeit von Au(111) durch dithiol-terminiertes Polyethylenglykol (PEG(thiol)) sowie deren Abhängigkeit von der Anzahl der PEG-Wiederholungseinheiten. In beiden Fällen beobachten wir, dass die Austrittsarbeit des Au(111) durch eine Monoschicht PEG(thiol)-Moleküle reduziert wird. Unsere Berechnungen zeigen, dass diese Änderung der Austrittsarbeit hauptsächlich durch (i) die Ladungsumlagerung aufgrund der Chemisorption und (ii) das intrinsische Dipolmoment der PEG(thiol)-Monoschicht verursacht wird. Die Größe des letzteren Beitrags hängt spürbar von der Anzahl der Wiederholungseinheiten ab und bewirkt somit eine Variation in der Reduktion der Austrittsarbeit. Das oszillatorische Verhalten spiegelt einen ausgeprägten Odd-Even-Effekt wider. Dadurch kann die Austrittsarbeit der Metallelektrode unter Berücksichtigung des Odd-Even-Effekts gesteuert werden. Die Konvergenz der selbstkonsistenten Felditeration für unsere Systeme ist nicht garantiert. Um die Konvergenz zu verbessern, schlagen wir die Verwendung eines speziell auf die FP-LAPW-Methode zugeschnittenen Mischalgorithmus vor. In einem auf Ag(111) basierenden System zeigt sich, dass eine Struktur mit drei Leerstellen in der Substratschicht besonders stabil ist. Dabei ist eine kontinuierliche Abnahme der Austrittsarbeit des Ag(111) feststellbar. Ähnlich wie beim Au(111) manifestiert sich der Odd-Even-Effekt, der auf das Dipolmoment der Molekularschicht zurückzuführen ist. / Charge injection (extraction) at an interface plays a crucial role to organic electronics because this injection (extraction) heavily affects the device performance. One of the most efficient way to optimize energy barriers of the injection (extraction) is modifying the work function of electrodes. In this dissertation, we investigate the modification of work function of Au(111) and Ag(111) induced by the dithiol-terminated polyethylene glycol (PEG(thiol)) as well as a dependence of the work function change on different numbers of PEG repeat units. We find that the work function of the Au(111) is reduced by a monolayer of PEG(thiol) molecules. Overall, our calculations indicate that the work function change is mainly induced by (i) the charge rearrangement due to chemisorption and (ii) the intrinsic dipole moment of the PEG(thiol) monolayer. The magnitude of the latter contribution noticeably depends on the number of repeat units and, thus, causes a variation in the reduction of the work function. The oscillatory behavior reflects a pronounced odd-even effect. As a result, the work function of the metal electrode would be controlled by considering the odd-even effect. Unfortunately, the convergence of the self-consistent field iteration is not guaranteed for our investigated systems. To make the smooth convergence, a mixing algorithm, which is applicable to FP-LAPW method, is devised. We add the Kerker preconditioner as well as further improvements to Pulay’s direct inversion in the iterative subspace. Using this method, one can avoid charge sloshing and noise in the exchange-correlation potential. This method is also implemented in the exciting code. We find the decrease of the work function of the Ag(111) surface is always presented. Similar to the Au(111) case, the odd-even effect is revealed, arising from the dipole moment of the molecular layer.