1,127 research outputs found
Indian Political and Cultural Influence in Cambodia (Kambuja) From the 6th to the 14th Centuries.
Abstract Not Provided
Electrophoretic Properties of Highly Charged Colloids: A Hybrid MD/LB Simulation Study
Using computer simulations, the electrophoretic motion of a positively
charged colloid (macroion) in an electrolyte solution is studied in the
framework of the primitive model. Hydrodynamic interactions are fully taken
into account by applying a hybrid simulation scheme, where the charged ions
(i.e. macroion and electrolyte), propagated via molecular dynamics (MD), are
coupled to a Lattice Boltzmann (LB) fluid. In a recent experiment it was shown
that, for multivalent salt ions, the mobility initially increases with
charge density , reaches a maximum and then decreases with further
increase of . The aim of the present work is to elucidate the behaviour
of at high values of . Even for the case of monovalent microions,
we find a decrease of with . A dynamic Stern layer is defined
that includes all the counterions that move with the macroion while subject to
an external electrical field. The number of counterions in the Stern layer,
, is a crucial parameter for the behavior of at high values of
. In this case, the mobility depends primarily on the ratio
(with the valency of the macroion). The previous contention that
the increase in the distortion of the electric double layer (EDL) with
increasing leads to the lowering of does not hold for high
. In fact, we show that the deformation of the EDL decreases with
increase of . The role of hydrodynamic interactions is inferred from
direct comparisons to Langevin simulations where the coupling to the LB fluid
is switched off. Moreover, systems with divalent counterions are considered. In
this case, at high values of the phenomenon of charge inversion is
found.Comment: accepted in J. Chem Phys., 10 pages, 9 figure
Hyperfine interaction and electronic spin fluctuation study on SrLaFeCoO (x = 0, 1, 2) by high-resolution back-scattering neutron spectroscopy
The study of hyperfine interaction by high-resolution inelastic neutron
scattering is not very well known compared to the other competing techniques
viz. NMR, M\"ossbauer, PACS etc. Also the study is limited mostly to
magnetically ordered systems. Here we report such study on
SrLaFeCoO (x = 0, 1, 2) of which first (SrFeCoO with x
= 0) has a canonical spin spin glass, the second (SrLaFeCoO with x = 1) has
a so-called magnetic glass and the third (LaFeCoO with x = 2) has a
magnetically ordered ground state. Our present study revealed clear inelastic
signal for SrLaFeCoO, possibly also inelastic signal for SrFeCoO
below the spin freezing temperatures but no inelastic signal at all
for for the magnetically ordered LaFeCoO in the neutron scattering
spectra. The broadened inelastic signals observed suggest hyperfine field
distribution in the two disordered magnetic glassy systems and no signal for
the third compound suggests no or very small hyperfine field at the Co nucleus
due to Co electronic moment. For the two magnetic glassy system apart from the
hyperfine signal due only to Co, we also observed electronic spin fluctuations
probably from both Fe and Co electronic moments. \end{abstract
Search algorithm for a gravitational wave signal in association with Gamma Ray Burst GRB030329 using the LIGO detectors
One of the brightest Gamma Ray Burst ever recorded, GRB030329, occurred
during the second science run of the LIGO detectors. At that time, both
interferometers at the Hanford, WA LIGO site were in lock and acquiring data.
The data collected from the two Hanford detectors was analyzed for the presence
of a gravitational wave signal associated with this GRB. This paper presents a
detailed description of the search algorithm implemented in the current
analysis.Comment: To appear in the Proceedings of 8th Gravitational Wave Data Analysis
Workshop (Milwaukee, WI) (Class. Quantum Grav.
The Critical Coupling Likelihood Method: A new approach for seamless integration of environmental and operating conditions of gravitational wave detectors into gravitational wave searches
Any search effort for gravitational waves (GW) using interferometric
detectors like LIGO needs to be able to identify if and when noise is coupling
into the detector's output signal. The Critical Coupling Likelihood (CCL)
method has been developed to characterize potential noise coupling and in the
future aid GW search efforts. By testing two hypotheses about pairs of
channels, CCL is able to identify undesirable coupled instrumental noise from
potential GW candidates. Our preliminary results show that CCL can associate up
to of observed artifacts with , to local noise sources,
while reducing the duty cycle of the instrument by . An approach
like CCL will become increasingly important as GW research moves into the
Advanced LIGO era, going from the first GW detection to GW astronomy.Comment: submitted CQ
Methods for Reducing False Alarms in Searches for Compact Binary Coalescences in LIGO Data
The LIGO detectors are sensitive to a variety of noise transients of
non-astrophysical origin. Instrumental glitches and environmental disturbances
increase the false alarm rate in the searches for gravitational waves. Using
times already identified when the interferometers produced data of questionable
quality, or when the channels that monitor the interferometer indicated
non-stationarity, we have developed techniques to safely and effectively veto
false triggers from the compact binary coalescences (CBCs) search pipeline
Property (RD) for Hecke pairs
As the first step towards developing noncommutative geometry over Hecke
C*-algebras, we study property (RD) (Rapid Decay) for Hecke pairs. When the
subgroup H in a Hecke pair (G,H) is finite, we show that the Hecke pair (G,H)
has (RD) if and only if G has (RD). This provides us with a family of examples
of Hecke pairs with property (RD). We also adapt Paul Jolissant's works in 1989
to the setting of Hecke C*-algebras and show that when a Hecke pair (G,H) has
property (RD), the algebra of rapidly decreasing functions on the set of double
cosets is closed under holomorphic functional calculus of the associated
(reduced) Hecke C*-algebra. Hence they have the same K_0-groups.Comment: A short note added explaining other methods to prove that the
subalgebra of rapidly decreasing functions is smooth. This is the final
version as published. The published version is available at: springer.co
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