291 research outputs found
Design of Boolean LUM Smoothers through Permutation Coloring Concept
Rank-order based LUM (lower-upper-middle) smoothers distinguishes by wide range of smoothing characteristics given by filter parameter. Thus, for the capability to achieve the best balance between noise suppression and signal details preservation, the LUM smoothers are preferred in smoothing applications. Thanks to threshold decomposition and stacking properties, the LUM smoothers belong to the class of stack filters. This paper is focused to the derivation of minimal positive Boolean function for LUM smoothers through permutation groups and a coloring concept
Adaptive Order-Statistic LMS Filters
The LMS-based adaptive order-statistic filters are presented in this paper. The adaptive Ll-filters as extension of the adaptive L-filter for two-dimensional filtering of noisy greyscale images is studied too. Their adaptation properties are studied by three types of noise, the additive white Gaussian noise, the impulsive noise or both, respectively. Moreover, the impulsive noise has the fixed noise value (Salt & Pepper noise). The problem of pixel value multiplicity and determination its position in the ordered input vector for adaptive Ll-filter is shown in this article. The two types of images with different of image complexity are used to demonstration of the power of time-spatial ordering
Extension of Impulse Detectors to Spatial Dimension and their Utilization as Switch in the LMS L-SD Filter
In this paper, one kind of adaptive LMS filters based on order statistics is used for two-dimensional filtration of noisy greyscale images degraded by mixed noise. The signal-dependent adaptive LMS L-filter (L-SD) consists of two normalized constrained adaptive LMS L-filters, because they have better convergence properties than simple LMS algorithm. Moreover, first filter suppresses the noise in homogeneous regions and second filter preserves the high components of filtered image. Some versions of spatial order statistic detectors were developed from the impulse detectors and were employed as switch between output these filters
V-I characteristics in the vicinity of order-disorder transition in vortex matter
The shape of the V-I characteristics leading to a peak in the differential
resistance r_d=dV/dI in the vicinity of the order-disorder transition in NbSe2
is investigated. r_d is large when measured by dc current. However, for a small
Iac on a dc bias r_d decreases rapidly with frequency, even at a few Hz, and
displays a large out-of-phase signal. In contrast, the ac response increases
with frequency in the absence of dc bias. These surprisingly opposite phenomena
and the peak in r_d are shown to result from a dynamic coexistence of two
vortex matter phases rather than from the commonly assumed plastic depinning.Comment: 12 pages 4 figures. Accepted for publication in PRB rapi
Evaluation of macro and microminerals in crude drugs and infusions of five herbs widely used as sedatives
It has been determined the concentration of fourteen micro and macrominerals (Al, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, P, Se, and Zn) in both crude drugs and infusions of Melissa officinalis L., Lamiaceae, Nepeta cataria L., Lamiaceae, Passiflora caerulea L., Passifloraceae, Tilia x moltkei Späth ex C.K. Schneid., Tiliaceae, and Valeriana officinalis L., Caprifoliaceae. These herbs are widely consumed by its sedative properties, either alone or in herb mixtures. All measurements were performed using an inductively coupled plasma optical emission spectrometer (ICP-OES). The products were obtained from regional markets, mainly in San Luis province (Argentina). The estimated daily intake was compared with current recommendations. All products and its infusions were included within the upper tolerable limits for minerals, in trace elements such as toxic elements present at low levels
Zinc recovery during refractory ore biooxidation by an indigenous consortium
Two enrichment cultures (one iron oxidizing and one sulfur oxidizing) obtained from an acid mine drainage were physiological and molecular characterized; the first of them showed 99% 16S rRNA gene sequence similarity with Leptospirillum ferrooxidans, while the sulfur oxidizing species was highly related to Acidithiobacillus ferrooxidans and Acidithiobacillus ferrivorans sequences although, unlike them, the species in the enrichment culture does not seem to be able to oxidize iron. The consortium constituted by both enrichment cultures achieved a successful biooxidation of Hualilan ore allowing the increase of gold recovery up to 96.4 % in the best culture condition (low pulp density in 1K medium). At the same time, this condition showed an effective zinc bioleaching (up to 86 %) although the recovery was much higher in cultures with initially supplemented iron; kinetics studies suggested that bioleaching rate in 1K medium at low pulp densities is controlled by diffusion through a layer mainly constituted by jarosite (rather than sulfur) which was detected in X-ray diffraction diagrams. The recovery of zinc as subproduct of the pretreatment to optimize gold recovery would also allow decrease the metallic charge of the leachates from the biooxidation tanks which is an environmental advantage.Centro de Investigación y Desarrollo en Fermentaciones Industriale
A Bragg glass phase in the vortex lattice of a type II superconductor
Although crystals are usually quite stable, they are sensitive to a
disordered environment: even an infinitesimal amount of impurities can lead to
the destruction of the crystalline order. The resulting state of matter has
been a longstanding puzzle. Until recently it was believed to be an amorphous
state in which the crystal would break into crystallites. But a different
theory predicts the existence of a novel phase of matter: the so-called Bragg
glass, which is a glass and yet nearly as ordered as a perfect crystal. The
lattice of vortices that can contain magnetic flux in type II superconductors
provide a good system to investigate these ideas. Here we show that neutron
diffraction data of the vortex lattice in type II superconductors provides
unambiguous evidence for a weak, power-law decay of the crystalline order
characteristic of a Bragg glass. The theory also predicts accurately the
electrical transport properties of superconductors; it naturally explains the
observed phase transition and the dramatic jumps in the critical current
associated with the melting of the Bragg glass. Moreover the model explains
experiments as diverse as X-ray scattering in disordered liquid crystals and
conductivity of electronic crystals.Comment: 9 pages, 4 figure
Insertion Magnets
Chapter 3 in High-Luminosity Large Hadron Collider (HL-LHC) : Preliminary
Design Report. The Large Hadron Collider (LHC) is one of the largest scientific
instruments ever built. Since opening up a new energy frontier for exploration
in 2010, it has gathered a global user community of about 7,000 scientists
working in fundamental particle physics and the physics of hadronic matter at
extreme temperature and density. To sustain and extend its discovery potential,
the LHC will need a major upgrade in the 2020s. This will increase its
luminosity (rate of collisions) by a factor of five beyond the original design
value and the integrated luminosity (total collisions created) by a factor ten.
The LHC is already a highly complex and exquisitely optimised machine so this
upgrade must be carefully conceived and will require about ten years to
implement. The new configuration, known as High Luminosity LHC (HL-LHC), will
rely on a number of key innovations that push accelerator technology beyond its
present limits. Among these are cutting-edge 11-12 tesla superconducting
magnets, compact superconducting cavities for beam rotation with ultra-precise
phase control, new technology and physical processes for beam collimation and
300 metre-long high-power superconducting links with negligible energy
dissipation. The present document describes the technologies and components
that will be used to realise the project and is intended to serve as the basis
for the detailed engineering design of HL-LHC.Comment: 19 pages, Chapter 3 in High-Luminosity Large Hadron Collider (HL-LHC)
: Preliminary Design Repor
Vortex dynamics and upper critical fields in ultrathin Bi films
Current-voltage (I-V) characteristics of quench condensed, superconducting,
ultrathin films in a magnetic field are reported. These I-V's show
hysteresis for all films, grown both with and without thin underlayers.
Films on Ge underlayers, close to superconductor-insulator transition (SIT),
show a peak in the critical current, indicating a structural transformation of
the vortex solid (VS). These underlayers, used to make the films more
homogeneous, are found to be more effective in pinning the vortices. The upper
critical fields (B) of these films are determined from the resistive
transitions in perpendicular magnetic field. The temperature dependence of the
upper critical field is found to differ significantly from Ginzburg-Landau
theory, after modifications for disorder.Comment: Phys Rev B, to be published Figure 6 replaced with correct figur
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