A superconductor with 4-fermion attraction perturbed by magnetic impurities

A superconductor with 4-fermion attraction, considered by Ma\'{c}kowiak and Tarasewicz is modified by adding to the Hamiltonian a long-range magnetic interaction $V$ between conduction fermions and localized distinguishable spin 1/2 magnetic impurities. $V$ has the form of a reduced s-d interaction. An upper and lower bound to the system's free energy density $f(H,\beta)$ is derived and the two bounds are shown to coalesce in the thermodynamic limit. The resulting mean-field equations for the gap $\Delta$ and a parameter $y$, characterizing the impurity subsystem are solved and the solution minimizing $f$ is found for various values of magnetic coupling constant $g$ and impurity concentration. The phase diagrams of the system are depicted with five distinct phases: the normal phase, unperturbed superconducting phase, perturbed superconducting phase with nonzero gap in the excitation spectrum, perturbed gapless superconducting phase and impurity phase with completely suppressed superconductivity.Comment: 21 pages, 3 figure

Spór o korzenie nazizmu. Hannah Arendt i Erica Voegelina koncepcje źródeł zjawiska

Published in 1951, The origins of totalitarianism was a quantum leap in Hannah Arendt’s academic career. The book made her one of the most important scholars of Nazi ideology. Arendt’s work also won wide acclaim, partly due to a critical review by Eric Voegelin, which did not remain without responses from the author (both in public and in private correspondence). This paper tries to reconstruct the debates of Hannah Arendt and Eric Voegelin (including in the articles New science of politics and Some problems of German hegemony) on the origins of Nazism

Developing national level informatics competencies for undergraduate nurses : methodological approaches from Australia and Canada

Health information systems are being implemented in countries by governments and regional health authorities in an effort to modernize healthcare. With these changes, there has emerged a demand by healthcare organizations for nurses graduating from college and university programs to have acquired nursing informatics competencies that would allow them to work in clinical practice settings (e.g. hospitals, clinics, home care etc). In this paper we examine the methods employed by two different countries in developing national level nursing informatics competencies expected of undergraduate nurses prior to graduation (i.e. Australia, Canada). This work contributes to the literature by describing the science and methods of nursing informatics competency development at a national level