17,218 research outputs found
The mechanism for the electrooxidation of procarbazine pharmaceutical preparation in alkaline media and its mathematical description
The mechanism for the electrooxidation of procarbazine in alkaline media has been proposed. The process is realized completely on the electrode surface and is adsorption-controlled. The oscillatory behavior in this case is more probable, than for neutral media and may be caused by influences of electrochemical oxidation and salt dissolution from the electrode surface
Running Gluon Mass from Landau Gauge Lattice QCD Propagator
The interpretation of the Landau gauge lattice gluon propagator as a massive
type bosonic propagator is investigated. Three different scenarios are
discussed: i) an infrared constant gluon mass; ii) an ultraviolet constant
gluon mass; iii) a momentum dependent mass. We find that the infrared data can
be associated with a massive propagator up to momenta MeV, with a
constant gluon mass of 723(11) MeV, if one excludes the zero momentum gluon
propagator from the analysis, or 648(7) MeV, if the zero momentum gluon
propagator is included in the data sets. The ultraviolet lattice data is not
compatible with a massive type propagator with a constant mass. The scenario of
a momentum dependent gluon mass gives a decreasing mass with the momentum,
which vanishes in the deep ultraviolet region. Furthermore, we show that the
functional forms used to describe the decoupling like solution of the
Dyson-Schwinger equations are compatible with the lattice data with similar
mass scales.Comment: Version to appear in J. Phys. G. New version include some rewriting
and new analysis. In particular, the section on the running mass is ne
Vehicle-Rear: A New Dataset to Explore Feature Fusion for Vehicle Identification Using Convolutional Neural Networks
This work addresses the problem of vehicle identification through
non-overlapping cameras. As our main contribution, we introduce a novel dataset
for vehicle identification, called Vehicle-Rear, that contains more than three
hours of high-resolution videos, with accurate information about the make,
model, color and year of nearly 3,000 vehicles, in addition to the position and
identification of their license plates. To explore our dataset we design a
two-stream CNN that simultaneously uses two of the most distinctive and
persistent features available: the vehicle's appearance and its license plate.
This is an attempt to tackle a major problem: false alarms caused by vehicles
with similar designs or by very close license plate identifiers. In the first
network stream, shape similarities are identified by a Siamese CNN that uses a
pair of low-resolution vehicle patches recorded by two different cameras. In
the second stream, we use a CNN for OCR to extract textual information,
confidence scores, and string similarities from a pair of high-resolution
license plate patches. Then, features from both streams are merged by a
sequence of fully connected layers for decision. In our experiments, we
compared the two-stream network against several well-known CNN architectures
using single or multiple vehicle features. The architectures, trained models,
and dataset are publicly available at https://github.com/icarofua/vehicle-rear
A spark-resistant bulk-micromegas chamber for high-rate applications
We report on the design and performance of a spark-resistant bulk-micromegas
chamber. The principle of this design lends itself to the construction of
large-area muon chambers for the upgrade of the detectors at the Large Hadron
Collider at CERN for luminosities in excess of 10**34/cm2/s or other high-rate
applications.Comment: 12 pages, 13 figure
Simulations of a mortality plateau in the sexual Penna model for biological ageing
The Penna model is a strategy to simulate the genetic dynamics of
age-structured populations, in which the individuals genomes are represented by
bit-strings. It provides a simple metaphor for the evolutionary process in
terms of the mutation accumulation theory. In its original version, an
individual dies due to inherited diseases when its current number of
accumulated mutations, n, reaches a threshold value, T. Since the number of
accumulated diseases increases with age, the probability to die is zero for
very young ages (n = T). Here, instead
of using a step function to determine the genetic death age, we test several
other functions that may or may not slightly increase the death probability at
young ages (n < T), but that decreases this probability at old ones. Our
purpose is to study the oldest old effect, that is, a plateau in the mortality
curves at advanced ages. Imposing certain conditions, it has been possible to
obtain a clear plateau using the Penna model. However, a more realistic one
appears when a modified version, that keeps the population size fixed without
fluctuations, is used. We also find a relation between the birth rate, the
age-structure of the population and the death probability.Comment: submitted to Phys. Rev.
Modelo de edificação para a produção de leitões em cama sobreposta.
bitstream/item/58282/1/CUsersPiazzonDocuments299.pd
Photoassociative ionization of Na inside a storage ring
Motivated by recent interest in low dimensional arrays of atoms, we
experimentally investigated the way cold collisional processes are affected by
the geometry of the considered atomic sample. More specifically, we studied the
case of photoassociative ionization (PAI) both in a storage ring where
collision is more unidirectional in character and in a trap with clear
undefinition of collision axis. First, creating a ring shaped trap (atomotron)
we investigated two-color PAI dependence with intensity and polarization of a
probing laser. The intensity dependence of the PAI rate was also measured in a
magneto-optical trap presenting equivalent temperature and density conditions.
Indeed, the results show that in the ring trap, the value of the PAI rate
constant is much lower and does not show evidences of saturation, unlike in the
case of the 3D-MOT. Cold atomic collisions in storage ring may represent new
possibilities for study.Comment: 5 pages, 5 figures; Accepted by Optics Communicatio
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