2,100 research outputs found
Entropy of spatial monopole currents in pure SU(2) QCD at finite temperature
We study properties of space-like monopole trajectories in the Maximal
Abelian gauge of quenched SU(2) QCD at the finite temperature. We concentrate
on infrared monopole clusters which are responsible for the confinement
properties of the theory. We determine numerically the effective action of the
monopoles projected onto the three-dimensional time-slice. Then we derive the
length distributions of the monopole loops and fix their entropy.Comment: 12 pages, 22 figures, RevTeX
Asynchronous vibration problem of centrifugal compressor
An unstable asynchronous vibration problem in a high pressure centrifugal compressor and the remedial actions against it are described. Asynchronous vibration of the compressor took place when the discharge pressure (Pd) was increased, after the rotor was already at full speed. The typical spectral data of the shaft vibration indicate that as the pressure Pd increases, pre-unstable vibration appears and becomes larger, and large unstable asynchronous vibration occurs suddenly (Pd = 5.49MPa). A computer program was used which calculated the logarithmic decrement and the damped natural frequency of the rotor bearing systems. The analysis of the log-decrement is concluded to be effective in preventing unstable vibration in both the design stage and remedial actions
Superconductivity without attraction in a quasi-one-dimensional metal
An array of one-dimensional conductors coupled by transverse hopping and
interaction is studied with the help of a variational wave function. This wave
function is devised as to account for one-dimensional correlation effects. We
show that under broad conditions our system possesses the superconducting
ground state even if no attraction is present. The superconducting mechanism is
of many-body nature and deviates substantially from BCS. The phase diagram of
the model is mapped. It consists of two ordered phases competing against each
other: density wave, spin or charge, and unconventional superconductivity.
These phases are separated by the first order transition. The symmetry of the
superconducting order parameter is a non-universal property. It depends on
particulars of the Hamiltonian. Within the framework of our model possible
choices are the triplet -wave and the singlet -wave. Organic
quasi-one-dimensional superconductors have similar phase diagram.Comment: 12 pages, 2 Encapsulated PostScript figures, revtex4; the model's
Hamiltonian is revised as compared to previous version, this revision affects
prediction of the order parameter symmetr
Transmission of Systemic AA Amyloidosis in Animals
Amyloidoses are a group of protein-misfolding disorders that are characterized by the deposition of amyloid fibrils in organs and/or tissues. In reactive amyloid A (AA) amyloidosis, serum AA (SAA) protein forms deposits in mice, domestic and wild animals, and humans that experience chronic inflammation. AA amyloid fibrils are abnormal beta-sheet-rich forms of the serum precursor SAA, with conformational changes that promote fibril formation. Extracellular deposition of amyloid fibrils causes disease in affected animals. Recent findings suggest that AA amyloidosis could be transmissible. Similar to the pathogenesis of transmissible prion diseases, amyloid fibrils induce a seeding-nucleation process that may lead to development of AA amyloidosis. We review studies of possible transmission in bovine, avian, mouse, and cheetah AA amyloidosis.ArticleVETERINARY PATHOLOGY. 51(2):363-371 (2014)journal articl
Non-local correlations in metals close to a charge order insulator transition
The charge ordering transition induced by the nearest-neighbor Coulomb
repulsion, V, in the 1/4-filled extended Hubbard model is investigated using
Cellular Dynamical Mean-Field Theory. We find a transition to a strongly
renormalized charge ordered Fermi liquid at VCO and a metal-to-insulator
transition at VMI>VCO. Short range antiferromagnetism occurs concomitanly with
the CO transition. Approaching the charge ordered insulator the Fermi surface
deforms and the scattering rate of electrons develops momentum dependence on
the Fermi surface.Comment: 4 pages, 6 Figures, accepted for publication in Physical Review
Letter
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