Phys21

Phys21
Author: American Physical Society
Publisher:
Total Pages: 72
Release: 2016-10-14
Genre:
ISBN: 9780998252995

A report by the Joint Task Force on Undergraduate Physics Programs

Isotopes

Isotopes
Author: U.S. Atomic Energy Commission
Publisher:
Total Pages: 386
Release: 1955
Genre: Isotopes
ISBN:

Calendar

Calendar
Author: University of Saskatchewan
Publisher:
Total Pages: 226
Release: 1927
Genre:
ISBN:

Rotational Spectra and Molecular Structure

Rotational Spectra and Molecular Structure
Author: James E. Wollrab
Publisher: Academic Press
Total Pages: 485
Release: 2013-10-22
Genre: Science
ISBN: 148319485X

Physical Chemistry, A Series of Monographs: Rotational Spectra and Molecular Structure covers the energy levels and rotational transitions. This book is divided into nine chapters that evaluate the rigid asymmetric top molecules and the nuclear spin statistics for asymmetric tops. Some of the topics covered in the book are the asymmetric rotor functions; rotational transition intensities; classes of molecules; nuclear spin statistics for linear molecules and symmetric tops; and classical appearance of centrifugal and coriolis forces. Other chapters deal with the energy levels and effects of centrifugal distortion, as well as the internuclear distance and moments of inertia. The discussion then shifts to the coriolis coupling effects on rotational constants and the perturbation treatment of vibration-rotational Hamiltonian. The last chapter is devoted to the examination of origin of the quadrupole interaction. The book can provide useful information to chemists, physicists, electrical engineers, students, and researchers.

Flux Pinning in Superconductors

Flux Pinning in Superconductors
Author: Teruo Matsushita
Publisher: Springer Science & Business Media
Total Pages: 483
Release: 2014-02-20
Genre: Technology & Engineering
ISBN: 3642453120

The book covers the flux pinning mechanisms and properties and the electromagnetic phenomena caused by the flux pinning common for metallic, high-Tc and MgB2 superconductors. The condensation energy interaction known for normal precipitates or grain boundaries and the kinetic energy interaction proposed for artificial Nb pins in Nb-Ti, etc. are introduced for the pinning mechanism. Summation theories to derive the critical current density are discussed in detail. Irreversible magnetization and AC loss caused by the flux pinning are also discussed. The loss originally stems from the ohmic dissipation of normal electrons in the normal core driven by the electric field induced by the flux motion. The readers will learn why the resultant loss is of hysteresis type in spite of such mechanism. The influence of the flux pinning on the vortex phase diagram in high Tc superconductors is discussed and the dependencies of the irreversibility field are also described on other quantities such as anisotropy of superconductor, specimen size and electric field strength. Recent developments of critical current properties in various high-Tc superconductors and MgB2 are introduced. Other topics are: singularity in the case of transport current in a parallel magnetic field such as deviation from the Josephson relation, reversible flux motion inside pinning potentials which causes deviation from the critical state model prediction, the concept of the minimization of energy dissipation in the flux pinning phenomena which gives the basis for the critical state model, etc. Significant reduction in the AC loss in AC wires with very fine filaments originates from the reversible flux motion which is dominant in the two-dimensional pinning. The concept of minimum energy dissipation explains also the behavior of flux bundle size which determines the irreversibility line under the flux creep. The new edition has been thoroughly updated, with new sections on the progress in enhancing the critical current density in high temperature superconductors by introduction of artificial pinning centers, the effect of packing density on the critical current density and irreversibility field in MgB2 and derivation of the force-balance equation from the minimization of the free energy including the pinning energy.