4,463 research outputs found
Open Access Policy: Numbers, Analysis, Effectiveness
The PASTEUR4OA project analyses what makes an Open Access (OA) policy
effective. The total number of institutional or funder OA policies worldwide is
now 663 (March 2015), over half of them mandatory. ROARMAP, the policy
registry, has been rebuilt to record more policy detail and provide more
extensive search functionality. Deposit rates were measured for articles in
institutions' repositories and compared to the total number of WoS-indexed
articles published from those institutions. Average deposit rate was over four
times as high for institutions with a mandatory policy. Six positive
correlations were found between deposit rates and (1) Must-Deposit; (2)
Cannot-Waive-Deposit; (3) Deposit-Linked-to-Research-Evaluation; (4)
Cannot-Waive-Rights-Retention; (5) Must-Make-Deposit-OA (after allowable
embargo) and (6) Can-Waive-OA. For deposit latency, there is a positive
correlation between earlier deposit and (7) Must-Deposit-Immediately as well as
with (4) Cannot-Waive-Rights-Retention and with mandate age. There are not yet
enough OA policies to test whether still further policy conditions would
contribute to mandate effectiveness but the present findings already suggest
that it would be useful for current and future OA policies to adopt the seven
positive conditions so as to accelerate and maximise the growth of OA.Comment: 49 pages, 21 figures, 15 tables. Pasteur4OA Work Package 3 report:
Open Access policies 201
An Estimation of the Gamma-Ray Burst Afterglow Apparent Optical Brightness Distribution Function
By using recent publicly available observational data obtained in conjunction
with the NASA Swift gamma-ray burst mission and a novel data analysis
technique, we have been able to make some rough estimates of the GRB afterglow
apparent optical brightness distribution function. The results suggest that 71%
of all burst afterglows have optical magnitudes with mR < 22.1 at 1000 seconds
after the burst onset, the dimmest detected object in the data sample. There is
a strong indication that the apparent optical magnitude distribution function
peaks at mR ~ 19.5. Such estimates may prove useful in guiding future plans to
improve GRB counterpart observation programs. The employed numerical techniques
might find application in a variety of other data analysis problems in which
the intrinsic distributions must be inferred from a heterogeneous sample.Comment: 15 pages including 2 tables and 7 figures, accepted for publication
in Ap
Exciton mediated one phonon resonant Raman scattering from one-dimensional systems
We use the Kramers-Heisenberg approach to derive a general expression for the
resonant Raman scattering cross section from a one-dimensional (1D) system
explicitly accounting for excitonic effects. The result should prove useful for
analyzing the Raman resonance excitation profile lineshapes for a variety of 1D
systems including carbon nanotubes and semiconductor quantum wires. We apply
this formalism to a simple 1D model system to illustrate the similarities and
differences between the free electron and correlated electron-hole theories.Comment: 10 pages, 6 figure
Chirality dependence of the radial breathing phonon mode density in single wall carbon nanotubes
A mass and spring model is used to calculate the phonon mode dispersion for
single wall carbon nanotubes (SWNTs) of arbitrary chirality. The calculated
dispersions are used to determine the chirality dependence of the radial
breathing phonon mode (RBM) density. Van Hove singularities, usually discussed
in the context of the single particle electronic excitation spectrum, are found
in the RBM density of states with distinct qualitative differences for zig zag,
armchair and chiral SWNTs. The influence the phonon mode density has on the two
phonon resonant Raman scattering cross-section is discussed.Comment: 6 pages, 2 figures, submitted to Phys. Rev.
The Effects of Isometric Contractions on Breathing and Pulse Rates in the Performance of a Modified Harvard Step Test
The degree of fitness as ascertained by performance of a modified Harvard Step Test did not increase over controls for isometrically trained individuals. However, improvement over a prior training period was apparent. The breathing rate is probably a satisfactory index of measurement for the Harvard Step Test but needs further elucidation
Tunable Resonant Raman Scattering from Singly Resonant Single Wall Carbon Nanotubes
We perform tunable resonant Raman scattering on 17 semiconducting and 7
metallic singly resonant single wall carbon nanotubes. The measured scattering
cross-section as a function laser energy provides information about a tube's
electronic structure, the lifetime of intermediate states involved in the
scattering process and also energies of zone center optical phonons. Recording
the scattered Raman signal as a function of tube location in the microscope
focal plane allows us to construct two-dimensional spatial maps of singly
resonant tubes. We also describe a spectral nanoscale artifact we have coined
the "nano-slit effect"
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