4,589 research outputs found
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 and
\ga_0>0 such that for all and for all \ga\in(0,\ga_0),
f_\ga(m) has no analytic continuation along the path (
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
Postmortale Organspende: es spricht mehr für die Zustimmungslösung als für die Widerspruchslösung
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
- …