938 research outputs found
Search for Neutrinoless Double Beta Decay with NEMO 3 and SuperNEMO
Since 2003 the NEMO~3 experiment has been searching for neutrinoless double
beta decay using about 10 kg of enriched isotopes. A limit of T_(1/2)(0nu) >
5.8 10**23 years at 90 % CL has been obtained for 100-Mo from the first two
years of data. Several measurements of two-neutrino double beta decays have
also been performed. A first NEMO 3 measurement of the half-life of 130-Te is
presented, giving a value of T_(1/2)(2nu) = (7.6 +- 1.5 (stat) +- 0.8 (syst))
10**20 years. In parallel, there is an active R&D programme for the SuperNEMO
experiment which is expected to commence data taking in 2012-2013 with 100-200
kg of enriched isotopes.Comment: 6 pages, 3 figures, Proceedings of the 2007 Europhysics Conference on
High Energy Physics, in Manchester, England, 19-25 July 200
Fluctuations of statistics among subregions of a turbulence velocity field
To study subregions of a turbulence velocity field, a long record of velocity
data of grid turbulence is divided into smaller segments. For each segment, we
calculate statistics such as the mean rate of energy dissipation and the mean
energy at each scale. Their values significantly fluctuate, in lognormal
distributions at least as a good approximation. Each segment is not under
equilibrium between the mean rate of energy dissipation and the mean rate of
energy transfer that determines the mean energy. These two rates still
correlate among segments when their length exceeds the correlation length. Also
between the mean rate of energy dissipation and the mean total energy, there is
a correlation characterized by the Reynolds number for the whole record,
implying that the large-scale flow affects each of the segments.Comment: 7 pages, accepted by Physics of Fluids (see http://pof.aip.org/
The read-out system of spatial distribution of thermoluminescence in meteorites
The thermoluminescence (TL) technique used for dating the terrestrial age of meteorites is based on the TL fading of interior samples. The depth dependence of the TL for Antarctic meteorites with fusion crust is measured. Usually, meteorites are powdered and their TL measured under a photomultiplier. In this case, a TL spatial distribution of a cross section of antarctic meteorites is measured using a read out system of spatial distribution of TL, since a meteorite is made up of inhomogeneous material. Antarctic meteorites MET-78028(L6) and ALH-77278(L13) are used
On Landau's prediction for large-scale fluctuation of turbulence energy dissipation
Kolmogorov's theory for turbulence in 1941 is based on a hypothesis that
small-scale statistics are uniquely determined by the kinematic viscosity and
the mean rate of energy dissipation. Landau remarked that the local rate of
energy dissipation should fluctuate in space over large scales and hence should
affect small-scale statistics. Experimentally, we confirm the significance of
this large-scale fluctuation, which is comparable to the mean rate of energy
dissipation at the typical scale for energy-containing eddies. The significance
is independent of the Reynolds number and the configuration for turbulence
production. With an increase of scale r above the scale of largest
energy-containing eddies, the fluctuation becomes to have the scaling r^-1/2
and becomes close to Gaussian. We also confirm that the large-scale fluctuation
affects small-scale statistics.Comment: 9 pages, accepted by Physics of Fluids (see http://pof.aip.org
Noble gases and mineralogy of primary igneous materials of the Yamato-793605 shergottite
Mineralogical and petrologic study on the Y-793605 lherzolitic shergottite using an optical microscope and an electron microprobe shows that this meteorite is a primary cumulate rock with close affinity to ALH77005 (and possibly to LEW88516), and is different from Shergotty. Strong shock effects. 30-50 GPa, are observed as finely fractured texture of pyroxene, maskelynite and brownish color olivine. Noble gas analyses by total melt and stepwise heating were performed on 17.86 and 50.99 mg primary igneous materials from Y-793605,10,respectively. Xe isotopic ratios show weak isotope signature for shergottite, which is different from those of nakhlites, Chassigny and ALH84001. Cosmic-ray exposure ages calculated from cosmogenic ^3He and ^Ne are 5.1-5.8 Ma, which is slightly longer than the ages, 3.3-4.0 Ma, reported for other two lherzolitic shergottites ALH77005 and LEW88516. Multistage exposure to cosmic-rays would be responsible for the difference. Apparent K-Ar age of 1430-1860 Ma is calculated, which is concordant with the young crystallization ages for martian meteorites, though the age is still ambiguous
Near-linear dynamics in KdV with periodic boundary conditions
Near linear evolution in Korteweg de Vries (KdV) equation with periodic
boundary conditions is established under the assumption of high frequency
initial data. This result is obtained by the method of normal form reduction
Synthetic biodegradable polymers as drug delivery systems for bone morphogenetic proteins
ArticleAdvanced Drug Delivery Reviews. 57(7): 1037-1048 (2005)journal articl
Global well-posedness for the KP-I equation on the background of a non localized solution
We prove that the Cauchy problem for the KP-I equation is globally well-posed
for initial data which are localized perturbations (of arbitrary size) of a
non-localized (i.e. not decaying in all directions) traveling wave solution
(e.g. the KdV line solitary wave or the Zaitsev solitary waves which are
localized in and periodic or conversely)
A New Class of Resonances at the Edge of the Two Dimensional Electron Gas
We measure the frequency dependent capacitance of a gate covering the edge
and part of a two-dimensional electron gas in the quantum Hall regime. In
applying a positive gate bias, we create a metallic puddle under the gate
surrounded by an insulating region. Charging of the puddle occurs via electron
tunneling from a metallic edge channel. Analysis of the data allows direct
extraction of this tunneling conductance. Novel conductance resonances appear
as a function of gate bias. Samples with gates ranging from 1-170~m along
the edge display strikingly similar resonance spectra. The data suggest the
existence of unexpected structure, homogeneous over long length scales, at the
sample edge.Comment: 13 pages (revtex) including 4 figure
The phase shift of line solitons for the KP-II equation
The KP-II equation was derived by [B. B. Kadomtsev and V. I.
Petviashvili,Sov. Phys. Dokl. vol.15 (1970), 539-541] to explain stability of
line solitary waves of shallow water. Stability of line solitons has been
proved by [T. Mizumachi, Mem. of vol. 238 (2015), no.1125] and [T. Mizumachi,
Proc. Roy. Soc. Edinburgh Sect. A. vol.148 (2018), 149--198]. It turns out the
local phase shift of modulating line solitons are not uniform in the transverse
direction. In this paper, we obtain the -bound for the local phase
shift of modulating line solitons for polynomially localized perturbations
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