300,467 research outputs found
Acoustic suspension system
An acoustic levitation system is described, with single acoustic source and a small reflector to stably levitate a small object while the object is processed as by coating or heating it. The system includes a concave acoustic source which has locations on opposite sides of its axis that vibrate towards and away from a focal point to generate a converging acoustic field. A small reflector is located near the focal point, and preferably slightly beyond it, to create an intense acoustic field that stably supports a small object near the reflector. The reflector is located about one-half wavelength from the focal point and is concavely curved to a radius of curvature (L) of about one-half the wavelength, to stably support an object one-quarter wavelength (N) from the reflector
The nature of power corrections in large approximation
We investigate the nature of power corrections and infrared renormalon
singularities in large approximation. We argue that the power
correction associated with a renormalon pole singularity should appear at O(1),
in contrast to the renormalon ambiguity appearing at , and give
an explanation why the leading order renormalon singularities are generically
poles.Comment: 6 page
Phase Transitions and Pairing Signature in Strongly Attractive Fermi Atomic Gases
We investigate pairing and quantum phase transitions in the one-dimensional
two-component Fermi atomic gas in an external field. The phase diagram,
critical fields, magnetization and local pairing correlation are obtained
analytically via the exact thermodynamic Bethe ansatz solution. At zero
temperature, bound pairs of fermions with opposite spin states form a singlet
ground state when the external field . A completely ferromagnetic
phase without pairing occurs when the external field . In the
region we observe a mixed phase of matter in which paired
and unpaired atoms coexist. The phase diagram is reminiscent of that of type II
superconductors. For temperatures below the degenerate temperature and in the
absence of an external field, the bound pairs of fermions form hard-core bosons
obeying generalized exclusion statistics.Comment: 9 pages, 5 figures, expanded version with additional text, references
and figure
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Gender differences in health-related quality of life following total laryngectomy
Background: The impact of a total laryngectomy on an individual's life has primarily been measured from a male viewpoint reflecting the demographics of a diagnosis of laryngeal cancer. A small number of studies have looked specifically at females, but very few are comparison studies. Consequently, there is little consistent research regarding any potential gender differences.
Aims: To investigate whether there are gender differences in perceptions of health-related quality of life and functional abilities following total laryngectomy.
Methods & Procedures: A total of 43 participants (22 males, 21 females), who had undergone a total laryngectomy procedure at least one year previously, took part in the study. They completed The European Organisation for Research and Treatment of Cancer Core Questionnaire Version 3.0 (EORTC QLQ-C30) in conjunction with the disease-specific Head & Neck Cancer Module (QLQ-H&N35).
Outcomes & Results: There were no significant differences between males and females on demographic and disease-related variables, except for the following: significantly more females lived alone and changed their employment status following surgery. Males had a significantly higher global health status/quality of life than females (p < 0.05) and significantly higher levels of physical (p = 0.01), emotional (p < 0.01), cognitive (p < 0.05) and social functioning (p < 0.05). After adjusting for differences in living arrangements and change in employment status, differences in emotional and social functioning remained significant. There was a general trend for females to have higher symptom/impairment levels and to report more treatment-related problems, but the majority of these differences were not significant.
Conclusions & Implications: Following total laryngectomy, females appear to be worsely affected in aspects of quality of life than males. Emotional and social functioning are particularly vulnerable. The findings imply that rehabilitation programmes after total laryngectomy need to evaluate quality of life and address these specific areas in order to improve patient-reported long-term outcomes
Quantum Phase Transitions and the Hidden Order in a Two-Chain Extended Boson Hubbard Model at Half-Odd-Integer Fillings
We study the phase diagram of two weakly coupled one-dimensional dipolar
boson chains at half-odd-integer fillings. We find that the system contains a
rich phase diagram. Four different phases are found. They are the Mott
insulators, the single-particle resonant superfluid, the paired superfluid, and
the bond- or inter-chain density waves. Moreover, the Mott insulating phase can
be further classified according to a hidden string order parameter, which is
analogous to the one investigated recently in the one-dimensional boson Mott
insulator at integer fillings.Comment: 7 pages, 2 figure
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