10,723 research outputs found
International perspectives on validity in action research: introduction to the special issue
This special issue has its roots in a series of meetings at the annual EGOS conferences held between 2001 and 2007. The Action Research sub-theme at these annual meetings has attracted almost 200 papers from authors on every continent. A particular focus of the group has been the socio-economic approach to action research developed by Henri Savall and the ISEOR team which discusses what Savall describes as "Generic Contingenciesâ and a âqualimetrics research methodologyâ (2003). The meetings have drawn together a truly international grouping of researchers who share a common interest in working closely with the world of practice to âmake a difference.
The effects of the reduction of manpower in the mining industry on mining social security systems and pension systems in particular. Studies: Social Policy Series 23, 1972
Digital phase-locked loops tracked by a relay sensor
An optimal algorithm is presented for tracking the
phase of a slowly modulating signal by means of digital sampling of its sign. Error bounds and a numerical illustration are given
The X-ray emission of magnetic cataclysmic variables in the XMM-Newton era
We review the X-ray spectral properties of magnetic cataclysmic binaries
derived from observations obtained during the last decade with the large X-ray
observatories XMM-Newton, Chandra and Suzaku. We focus on the signatures of the
different accretion modes which are predicted according to the values of the
main physical parameters (magnetic field, local accretion rate and white dwarf
mass). The observed large diversity of spectral behaviors indicates a wide
range of parameter values in both intermediate polars and polars, in line with
a possible evolutionary link between both classes.Comment: To appear in the Proceedings of "The Golden Age of Cataclysmic
Variables (Palermo 2011)", in Mem. Soc. Astron. It. (7 pages, 3 figures
Memory Effects in the Standard Model for Glasses
The standard model of glasses is an ensemble of two-level systems interacting
with a thermal bath. The general origin of memory effects in this model is a
quasi-stationary but non-equilibrium state of a single two-level system, which
is realized due to a finite-rate cooling and very slow thermally activated
relaxation. We show that single particle memory effects, such as negativity of
the specific heat under reheating, vanish for a sufficiently disordered
ensemble. In contrast, a disordered ensemble displays a collective memory
effect [similar to that described by Kovacs for glassy polymers], where
non-equilibrium features of the ensemble are monitored via a macroscopic
observable. An experimental realization of the effect can be used to further
assess the consistency of the model.Comment: 4 pages, 6 figure
Comparison of fragment partitions production in peripheral and central collisions
Ensembles of single-source events, produced in peripheral and central
collisions and correponding respectively to quasi-projectile and quasi-fusion
sources, are analyzed. After selections on fragment kinematic properties,
excitation energies of the sources are derived using the calorimetric method
and the mean behaviour of fragments of the two ensembles are compared.
Differences observed in their partitions, especially the charge asymmetry, can
be related to collective energy deposited in the systems during the collisions.Comment: 7 pages, 2 figures, presented at the International Workshop on
Multifragmentation and Related Topics, Caen France, 4-7th november 2007
(IWM2007
The ephemeris, orbital decay, and masses of 10 eclipsing HMXBs
We take advantage of more than 10 years of monitoring of the eclipsing HMXB
systems LMC X-4, Cen X-3, 4U 1700-377, 4U 1538-522, SMC X-1, IGR J18027-2016,
Vela X-1, IGR J17252-3616, XTE J1855-026, and OAO 1657-415 with the ASM
on-board RXTE and ISGRI on-board INTEGRAL to update their ephemeris. These
results are used to refine previous measurements of the orbital period decay of
all sources (where available) and provide the first accurate values of the
apsidal advance in Vela X-1 and 4U 1538-522. Updated values for the masses of
the neutron stars hosted in the ten HMXBs are also provided, as well as the
long-term lightcurves folded on the sources best determined orbital parameters.
These lightcurves reveal complex eclipse ingresses and egresses, that are
understood mostly as being due to the presence of accretion wakes. The results
reported in this paper constitute a database to be used for population and
evolutionary studies of HMXBs, as well as theoretical modelling of long-term
accretion in wind-fed X-ray binaries.Comment: Accepted for publication on A&
Estimations for the Single Diffractive production of the Higgs boson at the Tevatron and the LHC
The single diffractive production of the standard model Higgs boson is
computed using the diffractive factorization formalism, taking into account a
parametrization for the Pomeron structure function provided by the H1
Collaboration. We compute the cross sections at next-to-leading order accuracy
for the gluon fusion process, which includes QCD and electroweak corrections.
The gap survival probability () is also introduced to account for
the rescattering corrections due to spectator particles present in the
interaction, and to this end we compare two different models for the survival
factor. The diffractive ratios are predicted for proton-proton collisions at
the Tevatron and the LHC for the Higgs boson mass of = 120 GeV.
Therefore, our results provide updated estimations for the diffractive ratios
of the single diffractive production of the Higgs boson in the Tevatron and LHC
kinematical regimes.Comment: 20 pages, 6 figures, 3 table
Next 50 years of space research
Forecasting the next 50 years of space research is a dangerous game and a somewhat irresponsible action. Fortunately, the past 50 years have evidenced what remains in the realm of realism and of the feasible and what definitely belongs to the realm of utopia. Nevertheless those who, like me today, take the risk of forecasting such a relatively long time trend are sure of one thing: to be wrong
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