A Critical Assesment of Occluded Fronts

The aim of this work was the assessment about the structure and use of the conceptual model of occlusion in operational weather forecasting. In the beginning a survey has been made about the conceptual model of occlusion as introduced to operational forecasters in the Finnish Meteorological Institute (FMI). In the same context an overview has been performed about the use of the conceptual model in modern operational weather forecasting, especially in connection with the widespread use of numerical forecasts. In order to evaluate the features of the occlusions in operational weather forecasting, all the occlusion processes occurring during year 2003 over Europe and Northern Atlantic area have been investigated using the conceptual model of occlusion and the methods suggested in the FMI. The investigation has yielded a classification of the occluded cyclones on the basis of the extent the conceptual model has fitted the description of the observed thermal structure. The seasonal and geographical distribution of the classes has been inspected. Some relevant cases belonging to different classes have been collected and analyzed in detail: in this deeper investigation tools and techniques, which are not routinely used in operational weather forecasting, have been adopted. Both the statistical investigation of the occluded cyclones during year 2003 and the case studies have revealed that the traditional classification of the types of the occlusion on the basis of the thermal structure doesn t take into account the bigger variety of occlusion structures which can be observed. Moreover the conceptual model of occlusion has turned out to be often inadequate in describing well developed cyclones. A deep and constructive revision of the conceptual model of occlusion is therefore suggested in light of the result obtained in this work. The revision should take into account both the progresses which are being made in building a theoretical footing for the occlusion process and the recent tools and meteorological quantities which are nowadays available.

Essays in Philosophical Moral Psychology

The dissertation consists of four essays and a comprehensive introduction that discusses the topics, methods, and most prominent theories of philosophical moral psychology. I distinguish three main questions: What are the essential features of moral thinking? What are the psychological conditions of moral responsibility? And finally, what are the consequences of empirical facts about human nature to normative ethics? Each of the three last articles focuses on one of these issues. The first essay and part of the introduction are dedicated to methodological questions, in particular the relationship between empirical (social) psychology and philosophy. I reject recent attempts to understand the nature of morality on the basis of empirical research. One characteristic feature of moral thinking is its practical clout: if we regard an action as morally wrong, we either refrain from doing it even against our desires and interests, or else feel shame or guilt. Moral views seem to have a conceptual connection to motivation and emotions – roughly speaking, we can’t conceive of someone genuinely disapproving an action, but nonetheless doing it without any inner motivational conflict or regret. This conceptual thesis in moral psychology is called (judgment) internalism. It implies, among other things, that psychopaths cannot make moral judgments to the extent that they are incapable of corresponding motivation and emotion, even if they might say largely the words we would expect. Is internalism true? Recently, there has been an explosion of interest in so-called experimental philosophy, which is a methodological view according to which claims about conceptual truths that appeal to our intuitions should be tested by way of surveys presented to ordinary language users. One experimental result is that the majority of people are willing to grant that psychopaths make moral judgments, which challenges internalism. In the first article, ‘The Rise and Fall of Experimental Philosophy’, I argue that these results pose no real threat to internalism, since experimental philosophy is based on a too simple conception of the relationship between language use and concepts. Only the reactions of competent users in pragmatically neutral and otherwise conducive circumstances yield evidence about conceptual truths, and such robust intuitions remain inaccessible to surveys for reasons of principle. The epistemology of folk concepts must still be based on Socratic dialogue and critical reflection, whose character and authority I discuss at the end of the paper. The internal connection between moral judgment and motivation led many metaethicists in the past century to believe along Humean lines that judgment itself consists in a pro-attitude rather than a belief. This expressivist view, as it is called these days, has far-reaching consequences in metaethics. In the second essay I argue that perhaps the most sophisticated form of contemporary expressivism, Allan Gibbard’s norm-expressivism, according to which moral judgments are decisions or contingency plans, is implausible from the perspective of the theory of action. In certain circumstances it is possible to think that something is morally required of one without deciding to do so. Morality is not a matter of the will. Instead, I sketch on the basis of Robert Brandom’s inferentialist semantics a weak form of judgment internalism, according to which the content of moral judgment is determined by a commitment to a particular kind of practical reasoning. The last two essays in the dissertation emphasize the role of mutual recognition in the development and maintenance of responsible and autonomous moral agency. I defend a compatibilist view of autonomy, according to which agents who are unable to recognize right and wrong or act accordingly are not responsible for their actions – it is not fair to praise or blame them, since they lacked the relevant capacity to do otherwise. Conversely, autonomy demands an ability to recognize reasons and act on them. But as a long tradition in German moral philosophy whose best-known contemporary representative is Axel Honneth has it, both being aware of reasons and acting on them requires also the right sort of higher-order attitudes toward the self. Without self-respect and self-confidence we remain at the mercy of external pressures, even if we have the necessary normative competence. These attitudes toward the self, in turn, are formed through mutual recognition – we value ourselves when those who we value value us. Thus, standing in the right sort of relations of recognition is indirectly necessary for autonomy and moral responsibility. Recognition and valuing are concretely manifest in actions and institutions, whose practices make possible participation on an equal footing. Seeing this opens the way for a kind of normative social criticism that is grounded in the value of freedom and automomy, but is not limited to defending negative rights. It thus offers a new way to bridge the gap between liberalism and communitarianism.

Modelling vacuum arcs : from plasma initiation to surface interactions

A better understanding of vacuum arcs is desirable in many of today's 'big science' projects including linear colliders, fusion devices, and satellite systems. For the Compact Linear Collider (CLIC) design, radio-frequency (RF) breakdowns occurring in accelerating cavities influence efficiency optimisation and cost reduction issues. Studying vacuum arcs both theoretically as well as experimentally under well-defined and reproducible direct-current (DC) conditions is the first step towards exploring RF breakdowns. In this thesis, we have studied Cu DC vacuum arcs with a combination of experiments, a particle-in-cell (PIC) model of the arc plasma, and molecular dynamics (MD) simulations of the subsequent surface damaging mechanism. We have also developed the 2D Arc-PIC code and the physics model incorporated in it, especially for the purpose of modelling the plasma initiation in vacuum arcs. Assuming the presence of a field emitter at the cathode initially, we have identified the conditions for plasma formation and have studied the transitions from field emission stage to a fully developed arc. The 'footing' of the plasma is the cathode spot that supplies the arc continuously with particles; the high-density core of the plasma is located above this cathode spot. Our results have shown that once an arc plasma is initiated, and as long as energy is available, the arc is self-maintaining due to the plasma sheath that ensures enhanced field emission and sputtering. The plasma model can already give an estimate on how the time-to-breakdown changes with the neutral evaporation rate, which is yet to be determined by atomistic simulations. Due to the non-linearity of the problem, we have also performed a code-to-code comparison. The reproducibility of plasma behaviour and time-to-breakdown with independent codes increased confidence in the results presented here. Our MD simulations identified high-flux, high-energy ion bombardment as a possible mechanism forming the early-stage surface damage in vacuum arcs. In this mechanism, sputtering occurs mostly in clusters, as a consequence of overlapping heat spikes. Different-sized experimental and simulated craters were found to be self-similar with a crater depth-to-width ratio of about 0.23 (sim) - 0.26 (exp). Experiments, which we carried out to investigate the energy dependence of DC breakdown properties, point at an intrinsic connection between DC and RF scaling laws and suggest the possibility of accumulative effects influencing the field enhancement factor.