Interface free energy or surface tension: definition and basic properties

Interface free energy is the contribution to the free energy of a system due to the presence of an interface separating two coexisting phases at equilibrium. It is also called surface tension. The content of the paper is 1) the definition of the interface free energy from first principles of statistical mechanics; 2) a detailed exposition of its basic properties. We consider lattice models with short range interactions, like the Ising model. A nice feature of lattice models is that the interface free energy is anisotropic so that some results are pertinent to the case of a crystal in equilibrium with its vapor. The results of section 2 hold in full generality.Comment: 20 pages, 2 figure

Mixed Symmetry Solutions of Generalized Three-Particle Bargmann-Wigner Equations in the Strong-Coupling Limit

Starting from a nonlinear isospinor-spinor field equation, generalized three-particle Bargmann-Wigner equations are derived. In the strong-coupling limit, a special class of spin 1/2 bound-states are calculated. These solutions which are antisymmetric with respect to all indices, have mixed symmetries in isospin-superspin space and in spin orbit space. As a consequence of this mixed symmetry, we get three solution manifolds. In appendix \ref{b}, table 2, these solution manifolds are interpreted as the three generations of leptons and quarks. This interpretation will be justified in a forthcoming paper.Comment: 17 page

Interface Pinning and Finite-Size Effects in the 2D Ising Model

We apply new techniques developed in a previous paper to the study of some surface effects in the 2D Ising model. We examine in particular the pinning-depinning transition. The results are valid for all subcritical temperatures. By duality we obtained new finite size effects on the asymptotic behaviour of the two-point correlation function above the critical temperature. The key-point of the analysis is to obtain good concentration properties of the measure defined on the random lines giving the high-temperature representation of the two-point correlation function, as a consequence of the sharp triangle inequality: let tau(x) be the surface tension of an interface perpendicular to x; then for any x,y tau(x)+tau(y)-tau(x+y) >= 1/kappa(||x||+||y||-||x+y||), where kappa is the maximum curvature of the Wulff shape and ||x|| the Euclidean norm of x.Comment: 34 pages, Late

Non-Analyticity and the van der Waals Limit

We study the analyticity properties of the free energy f_\ga(m) of the Kac model at points of first order phase transition, in the van der Waals limit \ga\searrow 0. We show that there exists an inverse temperature $\beta_0$ and \ga_0>0 such that for all $\beta\geq \beta_0$ and for all \ga\in(0,\ga_0), f_\ga(m) has no analytic continuation along the path $m\searrow m^*$ ($m^*$ denotes spontaneous magnetization). The proof consists in studying high order derivatives of the pressure p_\ga(h), which is related to the free energy f_\ga(m) by a Legendre transform

Proyecto Fotovoz

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The metaphysics of Machian frame-dragging

The paper investigates the kind of dependence relation that best portrays Machian frame-dragging in general relativity. The question is tricky because frame-dragging relates local inertial frames to distant distributions of matter in a time-independent way, thus establishing some sort of non-local link between the two. For this reason, a plain causal interpretation of frame-dragging faces huge challenges. The paper will shed light on the issue by using a generalized structural equation model analysis in terms of manipulationist counterfactuals recently applied in the context of metaphysical enquiry by Schaffer (2016) and Wilson (2017). The verdict of the analysis will be that frame-dragging is best understood in terms of a novel type of dependence relation that is half-way between causation and grounding

The reception and implementation of ethical guidelines of the Swiss Academy of Medical Sciences in medical and nursing practice

Questions under study: We conducted a survey among Swiss health care professionals on the reception and implementation of a number of selected ethical guidelines of the Swiss Academy of Medical Sciences (SAMS). The following guidelines were chosen for evaluation: “Care of patients in the end of life”, “Palliative care”, “Borderline questions in intensive-care medicine” and “The determination of death in the context of organ transplantation”. Methods: Anonymous questionnaires were sent to 1933 physicians (general practitioners and internists) and nurses, randomly chosen from address lists of the relevant professional associations. We conducted a statistical analysis using SPSS 16.0. Results: The response rate was 43.1%. 16.3% of the responding physicians had never heard of the guidelines “Care of patients in the end of life”, 30.5% had already heard of them, 34.1% knew some of their contents and 19.1% were familiar with the complete content of the guidelines. 60.5% of those physicians and 56.0% of those nurses who had at least heard of these guidelines utilised them in clinical practice. The guidelines “Palliative care” and “Borderline questions in intensive- care medicine” yielded similar results. By contrast, only 0.5% of responding physicians reported never having heard of the guidelines “The determination of death in the context of organ transplantation”, 2.9% had already heard of them, 24.4% knew some of their contents and the vast majority of respondents (72.2%) considered themselves to be completely familiar with the guidelines. Conclusion: Knowledge of the evaluated guidelines is fairly widespread among Swiss GPs, internists and nurses. The guidelines are utilised in clinical practice by the majority of those care providers who are aware of their existence. The guidelines “The determination of death in the context of organ transplantation”, as a legally binding document, are even better known and routinely implemented in medical practice

A point is normal for almost all maps βx+α mod 1 or generalized β-transformations

We consider the map Tα,β(x):=βx+αmod1, which admits a unique probability measure μα,β of maximal entropy. For x[0,1], we show that the orbit of x is μα,β-normal for almost all (α,β)[0,1)×(1,∞) (with respect to Lebesgue measure). Nevertheless, we construct analytic curves in [0,1)×(1,∞) along which the orbit of x=0 is μα,β-normal at no more than one point. These curves are disjoint and fill the set [0,1)×(1,∞). We also study the generalized β-transformations (in particular, the tent map). We show that the critical orbit x=1 is normal with respect to the measure of maximal entropy for almost all