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Visualization of back pain data-A 3-D solution
Traditional approaches to gathering and visualizing pain data rely on two-dimensional (2-D) human body models, where different types of sensation are recorded with various monochrome symbols. We proposean alternative that uses a three-dimensional (3-D) representation of the human body, which can be marked in color to visualize and record pain data
Young people’s experiences using electric powered indoor-outdoor wheelchairs (EPIOCs): Potential for enhancing users’ development?
Purpose: To examine the experiences of severely physically disabled young people using electric powered indoor/outdoor chairs (EPIOCs).
Methods: A priori interview questions examined young people’s functioning with EPIOCs, pain and discomfort with EPIOC use and accidents or injuries resulting from EPIOC use. Eighteen young people (13 males and 5 females) aged 10 -18 (mean 15) years were interviewed by telephone using a qualitative framework approach. Participants were interviewed 10 -19 (mean 14.5) months after delivery of the chair. Diagnoses included muscular dystrophy (n = 10), cerebral palsy (n = 5), and ‘other’ (n =3).
Results: Many children reported positive functioning following EPIOC use, including increased independence and social activities like wheelchair football. However, EPIOC use was also associated with pain and discomfort, as well as perceived lack of safety, and minor accidents. Most young people and their families were fairly satisfied with the service and provision of their wheelchairs.
Conclusions: The findings suggest that disabled children’s development may benefit from the use of electric powered indoor/outdoor wheelchairs, although the advantages may come at certain costs to young people’s perceived and real safety. Recommendations to powered wheelchair providers include the demonstrated need for additional driving training as these young people mature
Two Stages in the evolution of binary alkali Bose-Einstein condensate mixtures towards phase segregation
Two stages of quantum spinodal decomposition is proposed and analyzed for
this highly non-equilibrium process. Both time and spatial scales for the
process are found. Qualitative agreement with existing data is found. Some
cases the agreements are quantitative. Further experimental verifications are
indicated.Comment: late
Motion of Vacancies in a Pinned Vortex Lattice: Origin of the Hall Anomaly
Physical arguments are presented to show that the Hall anomaly is an effect
of the vortex many-body correlation rather than that of an individual vortex.
Quantitatively, the characteristic energy scale in the problem, the vortex
vacancy formation energy, is obtained for thin films. At low temperatures a
scaling relation between the Hall and longitudinal resistivities is found, with
the power depending on sample details. Near the superconducting transition
temperature and for small magnetic fields the Hall conductivity is found to be
proportional to the inverse of the magnetic field and to the quadratic of the
difference between the measured and the transition temperatures.Comment: minor change
Invalidity of Classes of Approximated Hall Effect Calculations
In this comment, I point out a number of approximated derivations for the
effective equation of motion, now been applied to d-wave superconductors by
Kopnin and Volovik are invalid. The major error in those approximated
derivations is the inappropriate use of the relaxation time approximation in
force-force correlation functions, or in force balance equations, or in similar
variations. This approximation is wrong and unnecessary.Comment: final version, minor changes, to appear in Phys. Rev. Let
Geometric phases in dressed state quantum computation
Geometric phases arise naturally in a variety of quantum systems with
observable consequences. They also arise in quantum computations when dressed
states are used in gating operations. Here we show how they arise in these
gating operations and how one may take advantage of the dressed states
producing them. Specifically, we show that that for a given, but arbitrary
Hamiltonian, and at an arbitrary time {\tau}, there always exists a set of
dressed states such that a given gate operation can be performed by the
Hamiltonian up to a phase {\phi}. The phase is a sum of a dynamical phase and a
geometric phase. We illustrate the new phase for several systems.Comment: 4 pages, 2 figure
Magnus Force on Quantum Hall Skyrmions and Vortices
We have discussed here the Magnus force acting on the vortices and skyrmions
in the quantum Hall systems. We have found that it is generated by the
chirality of the system which is associated with the Berry phase and is same
for both the cases.Comment: 5 page
Enhanced stability of hydrogen atoms at the graphene/graphane interface of nanoribbons
The thermal stability of graphene/graphane nanoribbons (GGNRs) is
investigated using density functional theory. It is found that the energy
barriers for the diffusion of hydrogen atoms on the zigzag and armchair
interfaces of GGNRs are 2.86 and 3.17 eV, respectively, while the diffusion
barrier of an isolated H atom on pristine graphene was only ~0.3 eV. These
results unambiguously demonstrate that the thermal stability of GGNRs can be
enhanced significantly by increasing the hydrogen diffusion barriers through
graphene/graphane interface engineering. This may provide new insights for
viable applications of GGNRs.Comment: 13 pages, 1 figure, 2 tables to appear in Appl. Phys. Let
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