A Generalization of Haldane state-counting procedure and π\pi-deformations of statistics

We consider the generalization of Haldane's state-counting procedure to describe all possible types of exclusion statistics which are linear in the deformation parameter $g$. The statistics are parametrized by elements of the symmetric group of the particles in question. For several specific cases we determine the form of the distribution functions which generalizes results obtained by Wu. Using them we analyze the low-temperature behavior and thermodynamic properties of these systems and compare our results with previous studies of the thermodynamics of a gas of $g$-ons. Various possible physical applications of these constructions are discussed.Comment: 17 pages, latex, 6 figures small corrections were made, reference and acknowledgments are adde

Exact vortex nucleation and cooperative vortex tunneling in dilute BECs

With the imminent advent of mesoscopic rotating BECs in the lowest Landau level (LLL) regime, we explore LLL vortex nucleation. An exact many-body analysis is presented in a weakly elliptical trap for up to 400 particles. Striking non-mean field features are exposed at filling factors >>1 . Eg near the critical rotation frequency pairs of energy levels approach each other with exponential accuracy. A physical interpretation is provided by requantising a mean field theory, where 1/N plays the role of Planck's constant, revealing two vortices cooperatively tunneling between classically degenerate energy minima. The tunnel splitting variation is described in terms of frequency, particle number and ellipticity.Comment: 4 pages,4 figure

Comparison of the technical performance of a discretely supported slab track system and an embedded slab track system in a high-speed railway

Slab tracks are increasingly used for High-Speed Railways (HSR) as opposed to the conventional ballasted track. This is due to many factors, including increased durability and sustainability, as the slab track can sustain higher dynamic loading with less maintenance and disruption to railway services. In line with this, this paper reports on preliminary work on the development and application of a 3D structural model using the Finite Element Analysis (FEA) software ABAQUS. The research aims at evaluating comparatively the behaviour of two types of slab track systems; namely, the RHEDA Track System (RTS), which is a German system, and the Balfour Beatty (UK) Embedded Rail System (ERS). The modelled track structures consist of a rail fastened onto a slab laid on a suitable foundation. The foundation comprises a Hydraulically Bound Layer (HBL) placed on a Frost Protection Layer (FPL) overlaying the subgrade soil. The paper reports on findings of static loading on a straight railway section investigating the relationship between slab the thickness values and the corresponding displacements (deflections) and related stresses along the load path. Ongoing research is further developing the model to assess the dynamic behaviour of HSR slab track including the railway geometry-structure interaction particularly at bends

The structure and petrology of the Cnoc nan Cuilean Intrusion, Loch Loyal Syenite Complex, NW Scotland

In NW Scotland, several alkaline intrusive complexes of Silurian age intrude the Caledonian orogenic front. The most northerly is the Loch Loyal Syenite Complex, which is divided into three separate intrusions (Ben Loyal, Beinn Stumanadh and Cnoc nan Cuilean). Mapping of the Cnoc nan Cuilean intrusion shows two main zones: a Mixed Syenite Zone (MZ) and a Massive Leucosyenite Zone (LZ), with a gradational contact. The MZ forms a lopolith, with multiple syenitic lithologies, including early basic melasyenites and later felsic leucosyenites. Leucosyenite melts mixed and mingled with melasyenites, resulting in extreme heterogeneity within the MZ. Continued felsic magmatism resulted in formation of the relatively homogeneous LZ, invading western parts of the MZ and now forming the topographically highest terrane. The identification of pegmatites, microgranitic veins and unusual biotite-magnetite veins demonstrates the intrusion's complex petrogenesis. Cross-sections have been used to create a novel 3D GoCad™ model contributing to our understanding of the intrusion. The Loch Loyal Syenite Complex is known to have relatively high concentrations of rare earth elements (REEs), and thus the area has potential economic and strategic value. At Cnoc nan Cuilean, abundant REE-bearing allanite is present within melasyenites of the MZ. Extensive hydrothermal alteration of melasyenites here formed steeply dipping biotite-magnetite veins, most enriched in allanite and other REE-bearing accessories. This study has thus identified the area of greatest importance for further study of REE enrichment processes in the Cnoc nan Cuilean intrusion

The Effect of Crystallization on the Pulsations of White Dwarf Stars

We consider the pulsational properties of white dwarf star models with temperatures appropriate for the ZZ Ceti instability strip and with masses large enough that they should be substantially crystallized. Our work is motivated by the existence of a potentially crystallized DAV, BPM 37093, and the expectation that digital surveys in progress will yield many more such massive pulsators. A crystallized core makes possible a new class of oscillations, the torsional modes, although we expect these modes to couple at most weakly to any motions in the fluid and therefore to remain unobservable. The p-modes should be affected at the level of a few percent in period, but are unlikely to be present with observable amplitudes in crystallizing white dwarfs any more than they are in the other ZZ Ceti's. Most relevant to the observed light variations in white dwarfs are the g-modes. We find that the kinetic energy of these modes is effectively excluded from the crystallized cores of our models. As increasing crystallization pushes these modes farther out from the center, the mean period spacing between radial overtones increases substantially with the crystallized mass fraction. In addition, the degree and structure of mode trapping is affected. The fact that some periods are strongly affected by changes in the crystallized mass fraction while others are not suggests that we may be able to disentangle the effects of crystallization from those due to different surface layer masses.Comment: 18 pages, 5 figures, accepted on 1999 July 2 for publication in the Astrophysical Journa

Anomalous hydrodynamics and "normal" fluids in rapidly rotating BECs

In rapidly rotating bose systems we show that there is a region of anomalous hydrodynamics whilst the system is still condensed, which coincides with the mean field quantum Hall regime. An immediate consequence is the absence of a normal fluid in any conventional sense. However, even the superfluid hydrodynamics is not described by conventional Bernoulli and continuity equations. We show there are kinematic constraints which connect spatial variations of density and phase, that the positions of vortices are not the simplest description of the dynamics of such a fluid (despite their utility in describing the instantaneous state of the condensate) and that the most compact description allows solution of some illuminating examples of motion. We demonstrate, inter alia, a very simple relation between vortices and surface waves. We show the surface waves can form a "normal fluid" which absorbs energy and angular momentum from vortex motion in the trap. The time scale of this process is sensitive to the initial configuration of the vortices, which can lead to long-lived vortex patches - perhaps related to those observed at JILA.Comment: 4 pages; 1 sentence and references modifie

Geotechnical properties of paper recycling waste streams

This paper studies two waste streams of the paper recycling industry for potential use in geotechnical applications. Namely, de-inking paper sludge from the secondary treatment stage, and paper sludge ash (PSA) obtained from the incineration of this sludge. Salient geotechnical properties of the statically compacted sludge before and after stabilisation with lime or PSA are presented. Tests include shear box testing, uniaxial compressive strength (UCS) testing, 1-D swelling and compression in oedometric conditions, p-wave velocity measurements using a Portable Ultrasonic Non-destructive Digital Indicating Tester (PUNDIT), and filter paper testing to determine water retention characteristics. The volume changes of the untreated sludge were found to be considerable in all above tests; however its shear strength at a highly compacted state was overall adequate. Chemical stabilization of the sludge was effective in reducing volume changes. The PSA was also assessed as a silt soil stabiliser. As geomaterial stabiliser, PSA was found to have a similar or better performance than lime. Overall the results are encouraging and indicate that it is possible to use paper industry waste in geotechnical applications