Investigation of Surface Integrity Induced by Ultra-Precision Grinding and Scratching of Glassy Carbon.

Glassy carbon provides material characteristics that make it a promising candidate for use as a mould material in precision glass moulding. However, to effectively utilize glassy carbon, a thorough investigation into the machining of high-precision optical surfaces is necessary, which has not been thoroughly investigated. This research analyses the process of material removal and its resulting surface integrity through the use of nano-scratching and ultra-precision grinding. The nano-scratching process begins with ductile plastic deformation, then progresses with funnel-shaped breakouts in the contact zone, and finally concludes with brittle conchoidal breakouts when the cutting depth is increased. The influence of process factors and tool-related parameters resulting from grinding has discernible impacts on the ultimate surface roughness and topography. Enhancing the cutting speed during cross-axis kinematic grinding results in improved surface roughness. Increasing the size of diamond grains and feed rates leads to an increase in surface roughness. An achievable surface roughness of Ra < 5 nm together with ductile-regime grinding behaviour meet optical standards, which makes ultra-precision grinding a suitable process for optical surface generation.

The strong arm of the law: a unified account of necessary and contingent laws of nature.

A common feature of all standard theories of the laws of nature is that they are 'absolutist': They take laws to be either all metaphysically necessary or all contingent. Science, however, gives us reason to think that there are laws of both kinds, suggesting that standard theories should make way for 'non-absolutist' alternatives: theories which accommodate laws of both modal statuses. In this paper, we set out three explanatory challenges for any candidate non-absolutist theory, and discuss the prospects of the two extant candidates in light of these challenges. We then develop our own non-absolutist theory, the essentialist DTA account, which combines the nomic-necessitation or DTA account with an essentialist approach to metaphysical modality in order to meet the three explanatory challenges. Finally, we argue that the distinction between kinematical and dynamical laws found in physical theories supports both non-absolutism in general and our proposed essentialist DTA view in particular.

The modal status of the laws of nature. Tahko's hybrid view and the kinematical/dynamical distinction.

In a recent paper, Tuomas Tahko has argued for a hybrid view of the laws of nature, according to which some physical laws are metaphysically necessary, while others are metaphysically contingent. In this paper, we show that his criterion for distinguishing between these two kinds of laws - which crucially relies on the essences of natural kinds - is on its own unsatisfactory. We then propose an alternative way of drawing the metaphysically necessary/contingent distinction for laws of physics based on the central kinematical/dynamical distinction used in physical theorising, and argue that the criterion can be used to amend Tahko's own account, but also that it can be combined with different metaphysical views about the source of necessity.

Thoughts on the Present and Future of Psychoanalytic Education.

This paper originated in a series of dialogues between the authors over a period of approximately one year, focused on present problems (and possible solutions) in psychoanalytic education, internationally but particularly in the U.S. Both authors have been involved in psychoanalytic education and governance over many years and share a concern with where psychoanalysis presently stands and where it is going. They share the experience of being part of what today is a significant minority of psychoanalysts involved in academic pursuits, thus being situated at the boundary between psychoanalysis and university-based psychiatry as professions. Having been involved in the leadership of both psychoanalytic and psychiatric organizations, they share an interest in organizational theory, an additional joint interest influencing their approach to institutional aspects of psychoanalysis. Despite these commonalities, however, they have been identified as having differently shaded positions and views within psychoanalytic politics: Robert Michels, as relatively conservative regarding controversial issues in psychoanalytic institutional functioning and governance, and Otto Kernberg as inclined toward rapid change regarding these issues (Auchincloss and Michels 2003; Kernberg 2014). This difference determined a dynamic of particular interest in their dialogue: the extent to which mutual respect yet differing viewpoints might issue in an analysis and joint recommendations that might be of interest to the field. In what follows, their achievement in that direction is spelled out in some detail.