1,884 research outputs found
RPYS i/o: A web-based tool for the historiography and visualization of citation classics, sleeping beauties, and research fronts
Reference Publication Year Spectroscopy (RPYS) and Multi-RPYS provide
algorithmic approaches to reconstructing the intellectual histories of
scientific fields. With this brief communication, we describe a technical
advancement for developing research historiographies by introducing RPYS i/o,
an online tool for performing standard RPYS and Multi-RPYS analyses
interactively (at http://comins.leydesdorff.net/). The tool enables users to
explore seminal works underlying a research field and to plot the influence of
these seminal works over time. This suite of visualizations offers the
potential to analyze and visualize the myriad of temporal dynamics of
scientific influence, such as citation classics, sleeping beauties, and the
dynamics of research fronts. We demonstrate the features of the tool by
analyzing--as an example--the references in documents published in the journal
Philosophy of Science
Nonlinear Development of the Secular Bar-mode Instability in Rotating Neutron Stars
We have modelled the nonlinear development of the secular bar-mode
instability that is driven by gravitational radiation-reaction (GRR) forces in
rotating neutron stars. In the absence of any competing viscous effects, an
initially uniformly rotating, axisymmetric polytropic star with a ratio
of rotational to gravitational potential energy is driven by
GRR forces to a bar-like structure, as predicted by linear theory. The pattern
frequency of the bar slows to nearly zero, that is, the bar becomes almost
stationary as viewed from an inertial frame of reference as GRR removes energy
and angular momentum from the star. In this ``Dedekind-like'' state, rotational
energy is stored as motion of the fluid in highly noncircular orbits inside the
bar. However, in less than 10 dynamical times after its formation, the bar
loses its initially coherent structure as the ordered flow inside the bar is
disrupted by what appears to be a purely hydrodynamical, short-wavelength,
``shearing'' type instability. The gravitational waveforms generated by such an
event are determined, and an estimate of the detectability of these waves is
presented.Comment: 25 pages, 9 figures, accepted for publication in ApJ, refereed
version, updated, for quicktime movie, see
http://www.phys.lsu.edu/~ou/movie/fmode/new/fmode.b181.om4.2e5.mo
Catalytic asymmetric synthesis of the alkaloid (+)-myrtine
A new protocol for the asymmetric synthesis of trans-2,6-disubstituted-4-piperidones has been developed using a catalytic enantioselective conjugate addition reaction in combination with a diastereoselective lithiation–substitution sequence; an efficient synthesis of (+)-myrtine has been achieved via this route.
Gravitational Waves from Rotating Proto-Neutron Stars
We study the effects of rotation on the quasi normal modes (QNMs) of a newly
born proto neutron star (PNS) at different evolutionary stages, until it
becomes a cold neutron star (NS). We use the
Cowling approximation, neglecting spacetime perturbations, and consider
different models of evolving PNS. The frequencies of the modes of a PNS are
considerably lower than those of a cold NS, and are further lowered by
rotation; consequently, if QNMs were excited in a sufficiently energetic
process, they would radiate waves that could be more easily detectable by
resonant-mass and interferometric detectors than those emitted by a cold NS. We
find that for high rotation rates, some of the g-modes become unstable via the
CFS instability; however, this instability is likely to be suppressed by
competing mechanisms before emitting a significant amount of gravitational
waves.Comment: 5 pages, proceedings of the 5th Edoardo Amaldi Conference On
Gravitational Wave
Citations: Indicators of Quality? The Impact Fallacy
We argue that citation is a composed indicator: short-term citations can be
considered as currency at the research front, whereas long-term citations can
contribute to the codification of knowledge claims into concept symbols.
Knowledge claims at the research front are more likely to be transitory and are
therefore problematic as indicators of quality. Citation impact studies focus
on short-term citation, and therefore tend to measure not epistemic quality,
but involvement in current discourses in which contributions are positioned by
referencing. We explore this argument using three case studies: (1) citations
of the journal Soziale Welt as an example of a venue that tends not to publish
papers at a research front, unlike, for example, JACS; (2) Robert Merton as a
concept symbol across theories of citation; and (3) the Multi-RPYS
("Multi-Referenced Publication Year Spectroscopy") of the journals
Scientometrics, Gene, and Soziale Welt. We show empirically that the
measurement of "quality" in terms of citations can further be qualified:
short-term citation currency at the research front can be distinguished from
longer-term processes of incorporation and codification of knowledge claims
into bodies of knowledge. The recently introduced Multi-RPYS can be used to
distinguish between short-term and long-term impacts.Comment: accepted for publication in Frontiers in Research Metrics and
Analysis; doi: 10.3389/frma.2016.0000
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