Phase boundary detection for dilution refrigerators

We describe a device to conveniently measure the positions of the phase boundaries in a dilution refrigerator. We show how a simple modification of a standard capacitive level gauge (segmentation of one of the electrodes) permits a direct calibration of the capacitance versus phase boundary position. We compare this direct calibration with the indirect procedure that must be adopted for a conventional capacitive level gauge. The device facilitates the correct adjustment of the 3He/4He fraction in the dilution refrigerator.Comment: 3 page

Rats, cockroaches and people like us : views of humanity and human right

Many people appear to believe that there are a growing number of religious conflicts in the world, particularly since the end of the Cold War. On closer examination, however, it seems that the number of conflicts of the type which are today often labelled 'ethnic' or' 'religious' has in fact been growing since the 1950s'. Many such conflicts were already detectable in the period of the Cold War, but at that time, they were usually interpreted within a framework of East-West relations

The Invisible Worlds of Religion and Economy

Twelve years ago I accepted my Chair at ISS with an inaugural lecture entitled Rats, Cockroaches and People Like Us, in which I discussed the relation between people’s views of humanity and actual human rights. In it I made a plea for an intelligent use of the wide range of religious and spiritual resources available to people all over the world for the sake of human rights. In subsequent years I have expanded this argument by advocating the inclusion of religious resources for development in the broadest sense. Twelve years later it seems that, at least in the Netherlands, this remains a controversial proposal, especially in view of the great changes in the political climate at home and abroad since the dramatic events in 2001

The (In)Effectiveness of the European Employment Strategy

Qualitative studies of the European Employment Strategy produce conflicting accounts of its effectiveness within the Member States. Furthermore, such studies are limited in that they predominantly concern a small number of country case studies and one or two particular policy issues. Obtaining an accurate overview of the effectiveness of the OMC is therefore problematic. This article constructs a quantitative framework to analyse the effectivnes of the EES and applies it to ten EU Member States between 2005-2009. The analysis differentiates between shallow voluntary compliance, whereby member state responses to the EES represent activities which they themselves identify as a priority, and deep voluntary normative compliance, whereby member state activity is related to specific Council recommendations to improve policies in a particular area. The paper finds substantial evidence for both forms of compliance, however, an analysis of the formation of country specific recommendations, reveals the deeply politically negotiated nature of their formation and the limitations of our findings

The Influence of Plastic Bulk Deformation on Surface Roughness and Frictional Behavior during Deep Drawing Processes

In Sheet Metal Forming (SMF) processes, friction does play an important role. This with respect to the increase of product quality demands and the ability of predicting these processes by for instance finite element simulations. The existing simulation models do not contain an adequate friction model. In SMF processes different contact situations can be distinguished. As a result different coefficients of friction are locally present, which influences the forming process.\ud \ud Experiments are performed on a testing device by which it is possible to simulate the operational conditions as present in SMF processes. This test rig is a combination of a tensile tester and a friction measuring device, by which it is possible to measure the coefficient of friction as a function of the operational conditions (velocity and contact pressure) and deformation (elastic or plastic) in a well controlled way. Friction is presented in a generalized Stribeck-curve in which the different lubrication regimes can be distinguished, i.e. Boundary Lubrication (BL) and Mixed Lubrication (ML), which are also occurring during SMF processes.\ud \ud In SMF processes the sheet material deforms elastically and plastically and therefore the surface roughness will change and as a consequence will influence the frictional behavior between sheet and tool. In this paper, the influence of plastic deformation on A) the surface microgeometry and B) as a consequence of that on the frictional behavior of the sheet-tool system is studied. With the aid of a 3D-surface interference microscope, the microgeometry of the deformed material has been analyzed. The result of this investigation is that the CLA-roughness due to the deformation first decreases and then increases with increasing deformation. Furthermore, friction is hardly influenced due to the change in surface roughness. No change in the shape and the level of the generalized Stribeck curve is found

No Anomalous Fluctuations Exist in Stable Equilibrium Systems

An equilibrium statistical system is known to be stable if the fluctuations of global observables are normal, when their dispersions are proportional to the number of particles, or to the system volume. A general theorem is rigorously proved for the case, when an observable is a sum of linearly independent terms: The dispersion of a global observable is normal if and only if all partial dispersions of its terms are normal, and it is anomalous if and only if at least one of the partial dispersions is anomalous. This theorem, in particular, rules out the possibility that in a stable system with Bose-Einstein condensate some fluctuations of either condensed or noncondensed particles could be anomalous. The conclusion is valid for arbitrary systems, whether uniform or nonuniform, interacting weakly or strongly. The origin of fictitious fluctuation anomalies, arising in some calculations, is elucidated.Comment: Latex file, 9 page

Numerical Approaches for Linear Left-invariant Diffusions on SE(2), their Comparison to Exact Solutions, and their Applications in Retinal Imaging

Left-invariant PDE-evolutions on the roto-translation group $SE(2)$ (and their resolvent equations) have been widely studied in the fields of cortical modeling and image analysis. They include hypo-elliptic diffusion (for contour enhancement) proposed by Citti & Sarti, and Petitot, and they include the direction process (for contour completion) proposed by Mumford. This paper presents a thorough study and comparison of the many numerical approaches, which, remarkably, is missing in the literature. Existing numerical approaches can be classified into 3 categories: Finite difference methods, Fourier based methods (equivalent to $SE(2)$-Fourier methods), and stochastic methods (Monte Carlo simulations). There are also 3 types of exact solutions to the PDE-evolutions that were derived explicitly (in the spatial Fourier domain) in previous works by Duits and van Almsick in 2005. Here we provide an overview of these 3 types of exact solutions and explain how they relate to each of the 3 numerical approaches. We compute relative errors of all numerical approaches to the exact solutions, and the Fourier based methods show us the best performance with smallest relative errors. We also provide an improvement of Mathematica algorithms for evaluating Mathieu-functions, crucial in implementations of the exact solutions. Furthermore, we include an asymptotical analysis of the singularities within the kernels and we propose a probabilistic extension of underlying stochastic processes that overcomes the singular behavior in the origin of time-integrated kernels. Finally, we show retinal imaging applications of combining left-invariant PDE-evolutions with invertible orientation scores.Comment: A final and corrected version of the manuscript is Published in Numerical Mathematics: Theory, Methods and Applications (NM-TMA), vol. (9), p.1-50, 201

Joseph von Eichendorff : aus dem Leben eines Taugenichts ; Novelle

Inhalt: Aus dem Leben eines Taugenichts (mit Stellenkommentar) Entstehungs- und Druckgeschichte Zum Text der vorliegenden Ausgabe Literaturverzeichni