The one dimensional Kondo lattice model at partial band filling

The Kondo lattice model introduced in 1977 describes a lattice of localized magnetic moments interacting with a sea of conduction electrons. It is one of the most important canonical models in the study of a class of rare earth compounds, called heavy fermion systems, and as such has been studied intensively by a wide variety of techniques for more than a quarter of a century. This review focuses on the one dimensional case at partial band filling, in which the number of conduction electrons is less than the number of localized moments. The theoretical understanding, based on the bosonized solution, of the conventional Kondo lattice model is presented in great detail. This review divides naturally into two parts, the first relating to the description of the formalism, and the second to its application. After an all-inclusive description of the bosonization technique, the bosonized form of the Kondo lattice hamiltonian is constructed in detail. Next the double-exchange ordering, Kondo singlet formation, the RKKY interaction and spin polaron formation are described comprehensively. An in-depth analysis of the phase diagram follows, with special emphasis on the destruction of the ferromagnetic phase by spin-flip disorder scattering, and of recent numerical results. The results are shown to hold for both antiferromagnetic and ferromagnetic Kondo lattice. The general exposition is pedagogic in tone.Comment: Review, 258 pages, 19 figure

A new formula for calculating the magnetic force between two coaxial thick circular coils with rectangular cross-section

The magnetic force exerted by an array of two coaxial thick circular coils with rectangular cross-sections in air is important to both electrical and mechanical engineering applications. The magnetic force is typically calculated by taking the integral over the entire space defined by the array. This calculation even for this simple array is an intractable problem and numerical methods have been extensively used. In this work, the integration was subdivided into five regions, and in four of them, an analytical formula was found. The method proposed here is based on the Green's function of the free space that leads to the elliptical integral of the first and second kind. The formula reveals new insights into how the geometry and relative positioning of the coils within the array determines the strength of the magnetic force. The thicker the coils are and the farther apart they are, the weaker the magnetic force is, and vice versa. This new formula is simpler and practically free of truncation errors, which are commonly encountered in numerical approximations. Several examples from the literature were used to corroborate the present formulation. The results show an excellent agreement with respect to the different numerical and semi-analytical approaches used by other authors

Acceptability of psychotherapy, pharmacotherapy, and self-directed therapies in Australians living with chronic hepatitis C

Despite the prevalence of psychiatric co-morbidity in chronic hepatitis C (CHC), treatment is under-researched. Patient preferences are likely to affect treatment uptake, adherence, and success. Thus, the acceptability of psychological supports was explored. A postal survey of Australian CHC outpatients of the Royal Adelaide Hospital and online survey of Australians living with CHC was conducted, assessing demographic and disease-related variables, psychosocial characteristics, past experience with psychological support, and psychological support acceptability. The final sample of 156 patients (58 % male) had significantly worse depression, anxiety, stress, and social support than norms. The most acceptable support type was individual psychotherapy (83 %), followed by bibliotherapy (61 %), pharmacotherapy (56 %), online therapy (45 %), and group psychotherapy (37 %). The most prominent predictor of support acceptability was satisfaction with past use. While individual psychotherapy acceptability was encouragingly high, potentially less costly modalities including group psychotherapy or online therapy may be hampered by low acceptability, the reasons for which need to be further explored.Benjamin J. R. Stewart, Deborah Turnbull, Antonina A. Mikocka-Walus, Hugh A. J. Harley, Jane M. Andrew