The Artist and the Rebel: The Art of Graffiti and Its Impact on Memory Architecture

The lasting presence of graffiti in major cities like Berlin raises the question, what kind of perspective does such an art form have on memory? Given that graffiti are written or painted on structures and buildings, which are already their own kind of monument, and that the content of graffiti tends towards the politically and socially critical, how are we to understand the relationship of these works to places of memory creation? Why, for example, do we sometimes give monumental protection (Denkmanlschutz) to works of graffiti, and why so often not? My research investigates the roll of graffiti in cultural memory and follows both after the theoretical work of Friedrich Nietzsche and Jan Mieszkowski and the empirical works of Dennis Beyer and Uta Papen, the latter of whom analyze the monumental value of graffiti and the roll of the public space. I expect that the graffiti artist is to be seen not as historically, but anti-historically minded and therefore critically engaged with the places that influence memory creation. This discourse will be shown to reveal, very much through graffiti’s own ephemeral and transient nature, the capacity of these messages to re-open the canvas of the public space to critical dialogue between peoples

Lattice defects in HPT processed fcc nanometals studied by differential scanning calorimetry

Die vorliegende Dissertation befasst sich mit der Untersuchung der Natur, Anordnung und Dichte der durch Severe Plastic Deformation (SPD) generierten Gitterdefekte in Nanomaterialien. Da diese Defekte in wichtigem Zusammenhang mit den aussergewöhnlichen physikalischen Eigenschaften von SPD Nanomaterialien stehen, ist ihre Analyse für das Verständnis dieser Eigenschaften von grosser Bedeutung. Eine sehr repräsentative SPD Methode ist die Hochdrucktorsion (High Pressure Torsion - HPT), da mit ihr der Verformungsgrad und der hydrostatische Druck kontrolliert eingestellt werden können. In dieser Arbeit wurden Proben von Cu und Ni verschiedener Reinheit mittels HPT bei verschiedenen hydrostatischen Drucken unterschiedlich stark verformt, bevor daran Messungen mittels Differential Scanning Kalorimetrie (DSC) vorgenommen wurden. Während in HPT Cu verformungsinduzierte Leerstellenagglomerate und Versetzungen nachgewiesen wurden, konnten in HPT Ni auch Einfach- bzw. Doppelleerstellen beobachtet werden. Die Gesamtkonzentration an Leerstellen war in Nickel höher als in Cu, was eher auf den Einfluss der homologen Verformungstemperatur als auf denjenigen der Stapelfehlerenergie zurückzuführen ist. Allgemein nehmen die Konzentrationen der verformungsinduzierten Gitterdefekte mit höherem Verformungsgrad und höherem hydrostatischen Druck zu. Für Ni wurde gezeigt, dass die thermische Stabilität der Gitterdefekte mit zunehmender Verunreinigung zunimmt. Für die Bestimmung der Aktivierungsenthalpien (Q) wurde die Kissinger Methode angewandt. Die Aktivierungsenthalpien der Peaks in Ni betragen Qvac = 0.65 eV und Qdisl = 0.95 eV, im Einklang mit der Interpretation, dass diese Peaks die Ausheilung von Einzel/ Doppelleerstellen bzw. die von Leerstellenagglomeraten und Versetzungen repräsentieren. Für den einzigen Ausheilpeak in HPT Cu ergibt sich eine Änderung von Q = 0.78 eV bis Q = 0.48 eV je nach HPT induziertem Verformungsgrad, in Übereinstimmung mit der Variation der Ausheiltemperatur. Da die Grösse der Aktivierungsenthalpie betreffend deren Abhängigkeit vom Verformungsgrad eindeutig mit der Grösse der lokalen inneren Spannungen korreliert, können letztere als Ursache der Änderung der Aktivierungsenthalpien mit dem Verformungsgrad angenommen werden. Im Rahmen dieser Dissertation wurden auch Pd Proben mit Wasserstoff versetzt und anschliessend einer HPT Verformung bei tiefen Temperaturen unterzogen. Die DSC Untersuchung zeigte die Bildung hoher Konzentrationen von Leerstellen-Wasserstoff Agglomeraten an (7*10-4), und ausserdem auch die Stabilisierung von Versetzungen mittels Wasserstoff, wie begleitende elektronenmikroskopische Untersuchungen ergeben haben.The current PhD thesis is concerned with the investigation of the nature, distribution and density of lattice defects in nanomaterials which have been processed by Severe Plastic Deformation (SPD). Since these defects have some importance for the exceptional physical properties of SPD nanomaterials, their careful analysis is to enable a better understanding of these properties. As a representative technique for SPD nanostructures, that of High Pressure Torsion (HPT) has been used because of its capability to accurately control strain and hydrostatic pressure. Samples of copper and nickel were deformed by HPT at different hydrostatic pressures to different shear strains, and subjected to different DSC investigations. While in HPT-processed Cu only vacancy agglomerates and dislocations were found, in HPT-processed Ni also single/double vacancies could be observed. The total concentration of vacancies including those of agglomerates was higher, indicating the influence of homologous processing temperature rather than that of stacking fault energy. Generally, the concentrations of all lattice defects increased with increasing strain and pressure applied. Concerning Ni, additional impurities have shown to stabilize the lattice defects resulting in an increased annealing temperature. Activation enthalpies Q were determined by DSC using Kissinger's method. For Ni, the activation enthalpies of the two annealing peaks were determined as Q_vac = 0.65 eV and Q_disl = 0.95 eV, respectively, indicating the annihilation of single or double vacancies, and that of dislocations and vacancy agglomerates, respectively. For the one annealing peak found in HPT Cu, Q amounts from Q = 0.78 eV down to 0.48 eV as a function of shear strain applied, in correspondence with the change of peak temperature. Due to the obvious correlation with the strain dependence of external and local internal stresses, the strain dependence of Q, can be attributed to the local internal stresses governing the annihilation of dislocations and/or vacancy agglomerates. In addition, pure palladium was hydrogenated, subsequently deformed by HPT and analyzed by DSC. For comparison hydrogen-free HPT processed samples were also investigated. The results, for the first time, gave evidence for the formation of vacancy-hydrogen clusters caused by HPT. The vacancy concentration produced in Pd-H by this method is with 7*10-4 extraordinarily high. Similar to the effect of impurities in Ni, hydrogen seems to stabilize vacancies but also other HPT induced lattice defects as it can be concluded from the increase in peak temperatures and from concomitant observations by transmission electron microscopy

Controlling the formation of sodium/black phosphorus intercalated compounds towards high sodium content

The solid-state synthesis of pure sodium-black phosphorus intercalation compounds (Na-BPICs) has been optimized in bulk for two stoichiometric ratios. Specifically, in-situ X-Ray diffraction (XRD) allowed the precise identification of the optimal temperature range for the formation of Na-BPICs: 94 °C–96 °C. Moreover, as the undesired formation of Na3P takes place at this very same range, we succeeded in introducing a new synthetic route based on a fast-thermal ball milling implementation that results in the bulk production of BPIC without Na3P in 9 out of 10 cases. Finally, by combining XRD, Raman spectroscopy, and DFT calculations we developed a new structural model for Na-based BPICs showing an increase of BP's unit cell with Na atoms incorporated in every second layer. These results will pave the way for the large-scale synthesis and application of pure BPICs, which are of great interest in fields such as optoelectronics or energy storage.PNICTOCHEM 804110 (G.A.)PID2019-111742-GA-I00CIDEGENT/2018/00

Enseñándole trucos nuevos a un perro viejo: intuición, razón y responsabilidad

According to one highly influential approach to moral responsibility, human beings are responsible (eligible to be praised or blamed) for what they do because they are responsive to reasons (Fischer & Ravizza 1998). However, this amounts to a descriptive assumption about human beings that may not be borne out by the empirical research. According to a recent trend in moral psychology (Haidt 2001), most human judgment is caused by fast, nonconscious, and intuitive processes, rather than explicit, conscious deliberation about one’s reasons. And when humans do engage in explicit deliberation, it primarily serves to provide post hoc rationalization of their intuitive judgments (confabulation). If this is correct, it is tempting to conclude that most of our judgments—and the actions we perform on their basis—are not genuine responses to reasons. The reasons-responsiveness approach would thus appear to be committed to the implausible conclusion that we are not responsible for very much after all, including, most problematically, our implicit biases. I argue that the reasons-responsiveness approach can avoid this conclusion by showing three things: (1) that affective and intuitive processes can be reasons-responsive; (2) that the responsiveness of those processes can be bolstered by the agent’s environment; and (3) that practices like blame are one of the key ways in which human beings are attuned to reasons over time. I argue that the first and second of these items, despite their initial plausibility, are insufficient on their own to explain why humans can be held accountable for things like implicit biases, and that the way forward is to appreciate what holding each other accountable does—i.e., its effects.Según una teoría influyente de la responsabilidad moral, los seres humanos son responsables (pueden ser disculpados o culpabilizados) cuando tienen la capacidad de responder a razones (Fischer & Ravizza 1998). Pero esta teoría hace una suposición descriptiva sobre los seres humanos que posiblemente no es consistente con investigaciones empíricas. De acuerdo con una tendencia reciente en la psicología moral (Haidt 2001), la mayor parte del juicio humano es resultado de un proceso inconsciente, rápido, e intuitivo en vez de un proceso consciente, deliberado, y racional. Y cuando el ser humano participa en la deliberación consciente, generalmente esta sirve para dar una justificación post hoc de sus intuiciones (“confabulación”). Si este modelo es correcto, uno puede concluir que la mayoría de nuestros juicios no están basados en una respuesta genuina basada en razones. Así, esta influyente teoría de la responsabilidad moral parece llevarnos a la conclusión de que no somos responsables por muchos de nuestros pensamientos y comportamientos, incluyendo los prejuicios implícitos. En este trabajo discuto que esta conclusión puede ser evitada mostrando: (1) que nuestras inclinaciones y procesos intuitivos pueden responder a razones; (2) que estos procesos pueden ser fortalecidos por el ambiente del individuo; y (3) que las prácticas sociales, como la culpa, son una forma clave en que los humanos se ajustan a las razones. Argumento que los puntos primero y segundo, a pesar de su plausibilidad inicial, son insuficientes para explicar por qué los humanos somos responsables de cosas tales como nuestros prejuicios implícitos, y que el modo de progresar en relación con este problema radica en apreciar los efectos de las prácticas sociales tales como la culpa

Learning Responsibly: Essays on Responsibility, Norm Psychology, and Personhood

This dissertation argues for a number of theses related to responsibility, norm psychology, and personhood. Although most of the papers argue for “standalone” theses, in the sense that their truth does not depend the truth of the others, the five papers collectively illustrate a broader view of humans as (a) responsible agents who are (b) self-governing and (c) equipped with a capacity for norms, and whose agency (d) centers on dynamic responsiveness to corrective feedback. Drawing on this broader picture, the dissertation sheds light on ethical questions about our social practices and technologies, as well as descriptive questions about the nature of substance use disorder. Most centrally, the dissertation argues that forward-looking considerations are relevant for responsibility, not merely because the consequences of our responsibility practices are desirable, but primarily because of a connection which I argue exists between relationships, norms, and learning. On the view I defend, an agent is a responsible agent only if she can learn from being held responsible, so as to regulate herself according to norms of which she presently falls short. I argue that, if it were not for the capacity of humans to learn from social corrective feedback, such as normative responses like praise and blame, humans would be unable to participate in norm-governed relationships and communities. It is in virtue of their participation in these relationships and communities that humans are subject to interpersonal norms, such that they can fulfill or violate these norms and be praiseworthy or blameworthy for doing so. So, without the kind of learning that makes participation in these relationships a possibility, humans could never be praiseworthy or blameworthy for anything that they do. The dissertation also argues that human norm psychology has implications for how we should relate to “social robots”—artificial agents designed to participate in relationships with humans. I argue that, like humans, social robots should be equipped with a capacity to recognize and respond to normative feedback. Lastly, the dissertation resists a common narrative about addiction as being a form of akrasia in which agents act against their own better judgment. While this is certainly a central aspect of many cases of addiction, I argue that it fails to appreciate the ways in which addiction sometimes interacts with a person’s identity and goals, especially in cases where the agent believes that the things she values would not be feasible if she did not continue to engage in addictive behavior