46,486 research outputs found
Reactor Searches for Neutrino Magnetic Moment as a Probe of Extra Dimensions
We present calculations of the magnetic moment contribution to neutrino
electron scattering in large extra dimension brane-bulk models (LED) with three
bulk neutrinos. We discuss the cases with two and three large extra dimensions
of sizes . The calculations are done using reactor flux from Uranium,
as the neutrino source. We find that if the electron neutrino mass is
chosen to be in the range of one eV, the differential cross section for
scattering for low electron recoil energy can be of the same
order as the presently explored values in reactor experiments. Furthermore the
spectral shape for the LED models is different from the four dimensional case.
Future higher precision reactor experiments can therefore be used to provide
new constraints on a class of large extra dimension theories.Comment: 8 pages; 3 figure
Relativity in space-times with short-distance structure governed by an observer-independent (Planckian) length scale
I show that it is possible to formulate the Relativity postulates in a way
that does not lead to inconsistencies in the case of space-times whose
short-distance structure is governed by an observer-independent length scale.
The consistency of these postulates proves incorrect the expectation that
modifications of the rules of kinematics involving the Planck length would
necessarily require the introduction of a preferred class of inertial
observers. In particular, it is possible for every inertial observer to agree
on physical laws supporting deformed dispersion relations of the type , at least for certain types of .Comment: Same formulas and results as in 1st version, but a change of notation
is introduced in order to clarify that the studied illustrative example is
consistent with the R.P. for both choices of the overall sign. 1 ref added
and 2 refs upgraded. Some rewording of the text in Sec5, and addition of an
analogy with background fields in ordinary electromagnetism which I use to
illustrate difference between space-times with an observer-independent Lp,
and space-times in which Lp is introduced without modifications of Special
Relativit
A study of energy concentration and drain in incompressible fluids
In this paper we examine two opposite scenarios of energy behavior for
solutions of the Euler equation. We show that if is a regular solution on a
time interval and if for some , where is the dimension of the fluid, then the energy at the
time cannot concentrate on a set of Hausdorff dimension samller than . The same holds for solutions of the three-dimensional
Navier-Stokes equation in the range . Oppositely, if the energy
vanishes on a subregion of a fluid domain, it must vanish faster than
(T-t)^{1-\d}, for any \d>0. The results are applied to find new exclusions
of locally self-similar blow-up in cases not covered previously in the
literature.Comment: an update of the previous versio
Semi-classical limit and minimum decoherence in the Conditional Probability Interpretation of Quantum Mechanics
The Conditional Probability Interpretation of Quantum Mechanics replaces the
abstract notion of time used in standard Quantum Mechanics by the time that can
be read off from a physical clock. The use of physical clocks leads to apparent
non-unitary and decoherence. Here we show that a close approximation to
standard Quantum Mechanics can be recovered from conditional Quantum Mechanics
for semi-classical clocks, and we use these clocks to compute the minimum
decoherence predicted by the Conditional Probability Interpretation.Comment: 8 pages, references adde
Development of mainshaft seals for advanced air breathing propulsion systems, phase 1 Final report, 25 Jun. 1965 - 25 Jul. 1967
Comparison of gas film mainshaft seals with rubbing contract seals for high temperature, high speed, and high pressure gas turbine application
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Electrospray synthesis of PLGA TIPS microspheres
We successfully demonstrate the synthesis of polymer microspheres using a single electrospray source, and show their physical characterisation. Electrospray has proven to be a versatile method to manufacture particles, giving tight control over size with quasi-monodisperse size distributions. It is a liquid atomisation technique that generates a monodisperse population of highly charged liquid droplets over a broad size range (nanometres to tens of microns). The droplets contain liquid precursors for the in-flight synthesis of particles, and control over the trajectory of these droplets can be precisely manipulated with the use of electric fields to drive them to a grounded substrate. This study reports a method to synthesize poly(lactic-co-glycolic) acid (PLGA) microspheres using the electrospray and thermally induced phase separation (TIPS) techniques, followed by subsequent freeze-drying, for particle production. These microspheres are of interest as vehicles for controlled drug release systems
Decoherence of Einstein-Podolsky-Rosen steering
We consider two systems A and B that share Einstein-Podolsky-Rosen (EPR)
steering correlations and study how these correlations will decay, when each of
the systems are independently coupled to a reservoir. EPR steering is a
directional form of entanglement, and the measure of steering can change
depending on whether the system A is steered by B, or vice versa. First, we
examine the decay of the steering correlations of the two-mode squeezed state.
We find that if the system B is coupled to a reservoir, then the decoherence of
the steering of A by B is particularly marked, to the extent that there is a
sudden death of steering after a finite time. We find a different directional
effect, if the reservoirs are thermally excited. Second, we study the
decoherence of the steering of a Schr\"odinger cat state, modeled as the
entangled state of a spin and harmonic oscillator, when the macroscopic system
(the cat) is coupled to a reservoir
The Ammann-Beenker tilings revisited
This paper introduces two tiles whose tilings form a one-parameter family of
tilings which can all be seen as digitization of two-dimensional planes in the
four-dimensional Euclidean space. This family contains the Ammann-Beenker
tilings as the solution of a simple optimization problem.Comment: 7 pages, 4 figure
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