4,803 research outputs found
Channeling of Electrons in a Crossed Laser Field
In this article a new analytical description of the effective interaction
potential for a charged particle in the field of two interfering laser beams is
presented. The potential dependence on the lasers intensities, orientation and
parameters of the particle entering the considered system is analyzed. It is
shown for the case of arbitrary lasers crossing angle that for different values
of projectile velocity the attracting potential becomes a scattering one so
that the channel axes and borders interchange each other. In addition the
projectile radiation spectral distribution is given and general estimations on
the expected beam radiation yield are outlined
Experience of caregivers with the survivors of Hepatitis C
Objectives: To assess and describe the experiences of those caring for hepatitis C patients in Karachi, Pakistan.
Methods: Using a qualitative approach, the study adopted a descriptive exploratory design for which 8 caregirers were selected through snowball sampling technique from different parts of Karachi. Data was collected between May and July 2010 through semi-structured interviews from the caregivers. The interviews were recorded on tape and were transcribed verbatim. The data was manually analysed for extracting themes and categories.
Results: The analyses of data led to one theme - \\u27deadly, dangerous, and devastating. Two associated categories could also be noted: \\u27perceptions and misperceptions of the caregivers about hepatitis C\\u27 and \\u27challenges and adversities of the disease.\\u27
Conclusion: The diagnosis of hepatitis C had a profound impact on patients\\u27 and the caregivers\\u27 wellbeing. Although to some extent, caregivers were found to have fulfilled their role, but it was evident that better disease knowledge, funds and social support could have further helped them to address issues related to the disease
Does the coagulation profile really matter in central venous cannulation? A review of the literature
Superfluid 4He dynamics beyond quasiparticle excitations
The dynamics of superfluid 4He at and above the Landau quasiparticle regime
is investigated by high precision inelastic neutron scattering measurements of
the dynamic structure factor. A highly structured response is observed above
the familiar phonon-maxon-roton spectrum, characterized by sharp thresholds for
phonon-phonon, maxon-roton and roton-roton coupling processes. The experimental
dynamic structure factor is compared to the calculation of the same physical
quantity by a Dynamic Many-body theory including three-phonon processes
self-consistently. The theory is found to provide a quantitative description of
the dynamics of the correlated bosons for energies up to about three times that
of the Landau quasiparticles.Comment: 5 pages, 3 figure
Hot electron driven enhancement of spin-lattice coupling in 4f ferromagnets observed by femtosecond x-ray magnetic circular dichroism
Femtosecond x-ray magnetic circular dichroism was used to study the
time-dependent magnetic moment of 4 fs electrons in the ferromagnets Gd and Tb,
which are known for their different spin-lattice coupling. We observe a
two-step demagnetization with an ultrafast demagnetization time of 750 fs
identical for both systems and slower times which differ sizeably with 40 ps
for Gd and 8 ps for Tb. We conclude that spin-lattice coupling in the
electronically excited state is enhanced up to orders of magnitude compared to
equilibrium.Comment: added reference 24, clarified the meaning of photo-induced,
emphasized that XMCD probes the magnetic moment localized at 4f electron
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