129 research outputs found
Composición multielemental y valor nutricional de "dumosa" (Ilex dumosa), "yerba mate" (I. paraguariensis) y su mezcla comercial en diferentes formas de uso
The multielement composition and nutritional value of "dumosa" (Ilex dumosa) (ID),
"yerba mate" (I. paraguariensis) (IP) and their commercial 70:30 mixture (ID:IP, w/w)
in crude drug, brewed mate and tea-bag-like infusion were studied by ICP-OES. This
method allowed the detection of an unprecedented number of elements for these
species. The order was K>Ca>Mg>P>Mn>Al>Na>Si>Fe in crude drug. IP showed higher
concentration of minerals than ID, but most extractability in the latter largely offset its
shortcomings. Brewed mate had higher nutritional value than mate tea because their
higher solute/solvent ratio. A portion of brewed mate of both species exceeded the daily
recommended intake (DRI) of Mn, and providing Mg, Cu, Fe, Zn and K, too. The portions of
mate tea not contribute significantly to the DRI. Some essential trace elements and many
ultra-traces ones that exist in crude drug were not detected in aqueous extracts. Most of
the heavy metals were not leached into extracts, and in any case never exceeded international
safety limits. Therefore, the aqueous extracts of ID and IP and its mixture are
interesting from the nutritional point of view in minerales, and safe in terms of health.La composición multielemental y el valor nutricional de "dumosa" (Ilex dumosa) (ID),
"yerba mate" (I. paraguariensis) (IP) y su mezcla comercial 70:30 (ID:IP, p/p) fue estudiada
por ICP-OES en droga cruda y dos formas de consumo: "cebadura" y "mate cocido". Este
método permitió detectar un número sin precedentes de elementos en estas especies. En
droga cruda, el orden resultó K>Ca>Mg>P>Mn>Al>Na>Si>Fe. IP mostró mayor concentración
de minerales que ID, pero la mayor extractabilidad en esta última compensó
en gran medida sus deficiencias. La cebadura mostró mayor valor nutricional que la
infusión, a causa de su mayor relación soluto/disolvente. La porción de cebadura de
ambas especies superó la ingesta diaria recomendada (IDR) de Mn, aportando también
Mg, Cu, Fe, Zn y K. La porción de mate cocido no contribuyó significativamente a la IDR.
Algunos elementos traza esenciales y muchos ultra-trazas presentes en droga cruda no
fueron detectados en los extractos acuosos. La mayoría de los metales pesados no fueron
lixiviados hacia los extractos, y en todo caso nunca excedieron los límites de seguridad
internacionales. Por ello, los extractos acuosos de ID e IP y sus mezclas son interesantes
desde el punto de vista nutricional y son seguros en cuanto a la salud.Fil: Maiocchi, Marcos G..
Universidad Nacional del NordesteFil: Del Vitto, Luis A..
Universidad Nacional de San LuisFil: Petenatti, Marta E..
Universidad Nacional de San LuisFil: Avanza, María V..
Universidad Nacional del NordesteFil: Pellerano, Roberto G..
Universidad Nacional del NordesteFil: Petenatti, Elisa M..
Universidad Nacional de San LuisFil: Marchevsky, Eduardo J.
Order in driven vortex lattices in superconducting Nb films with nanostructured pinning potentials
Driven vortex lattices have been studied in a material with strong pinning,
such as Nb films. Samples in which natural random pinning coexists with
artificial ordered arrays of defects (submicrometric Ni dots) have been
fabricated with different geometries (square, triangular and rectangular).
Three different dynamic regimes are found: for low vortex velocities, there is
a plastic regime in which random defects frustrate the effect of the ordered
array; then, for vortex velocities in the range 1-100 m/s, there is a sudden
increase in the interaction between the vortex lattice and the ordered dot
array, independent on the geometry. This effect is associated to the onset of
quasi long range order in the vortex lattice leading to an increase in the
overlap between the vortex lattice and the magnetic dots array. Finally, at
larger velocities the ordered array-vortex lattice interaction is suppresed
again, in agreement with the behavior found in numerical simulations.Comment: 8 text pages + 4 figure
Dynamical Phases of Driven Vortices Interacting with Periodic Pinning
The finite temperature dynamical phases of vortices in films driven by a
uniform force and interacting with the periodic pinning potential of a square
lattice of columnar defects are investigated by Langevin dynamics simulations
of a London model. Vortices driven along the [0,1] direction and at densities
for which there are more vortices than columnar defects () are
considered. At low temperatures, two new dynamical phases, elastic flow and
plastic flow, and a sharp transition between them are identified and
characterized according to the behavior of the vortex spatial order, velocity
distribution and frequency-dependent velocity correlationComment: 4 pages with 4 figures. To be published in Phys. Rev. B Rapid
Communication
Multielemental composition and nutritional value of "dumosa" (Ilex dumosa), "yerba mate" (I. paraguariensis) and their commercial mixture in different forms of use
La composición multielemental y el valor nutricional de "dumosa" (Ilex dumosa) (ID),"yerba mate" (I. paraguariensis) (IP) y su mezcla comercial 70:30 (ID:IP, p/p) fue estudiadapor ICP-OES en droga cruda y dos formas de consumo: "cebadura" y "mate cocido". Estemétodo permitió detectar un número sin precedentes de elementos en estas especies. Endroga cruda, el orden resultó K;Ca;Mg;P;Mn;Al;Na;Si;Fe. IP mostró mayor concentraciónde minerales que ID, pero la mayor extractabilidad en esta última compensóen gran medida sus deficiencias. La cebadura mostró mayor valor nutricional que lainfusión, a causa de su mayor relación soluto/disolvente. La porción de cebadura deambas especies superó la ingesta diaria recomendada (IDR) de Mn, aportando tambiénMg, Cu, Fe, Zn y K. La porción de mate cocido no contribuyó significativamente a la IDR. Algunos elementos traza esenciales y muchos ultra-trazas presentes en droga cruda nofueron detectados en los extractos acuosos. La mayoría de los metales pesados no fueronlixiviados hacia los extractos, y en todo caso nunca excedieron los límites de seguridadinternacionales. Por ello, los extractos acuosos de ID e IP y sus mezclas son interesantesdesde el punto de vista nutricional y son seguros en cuanto a la saludThe multielement composition and nutritional value of "dumosa" (Ilex dumosa) (ID),"yerba mate" (I. paraguariensis) (IP) and their commercial 70:30 mixture (ID:IP, w/w) in crude drug, brewed mate and tea-bag-like infusion were studied by ICP-OES. Thismethod allowed the detection of an unprecedented number of elements for thesespecies. The order was K;Ca;Mg;P;Mn;Al;Na;Si;Fe in crude drug. IP showed higherconcentration of minerals than ID, but most extractability in the latter largely offset itsshortcomings. Brewed mate had higher nutritional value than mate tea because theirhigher solute/solvent ratio. A portion of brewed mate of both species exceeded the dailyrecommended intake (DRI) of Mn, and providing Mg, Cu, Fe, Zn and K, too. The portions ofmate tea not contribute significantly to the DRI. Some essential trace elements and manyultra-traces ones that exist in crude drug were not detected in aqueous extracts. Most ofthe heavy metals were not leached into extracts, and in any case never exceeded internationalsafety limits. Therefore, the aqueous extracts of ID and IP and its mixture areinteresting from the nutritional point of view in minerales, and safe in terms of health
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
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
Critical points in the Bragg glass phase of a weakly pinned crystal of CaRhSn
New experimental data are presented on the scan rate dependence of the
magnetization hysteresis width ( critical current
density ) in isothermal scans in a weakly pinned single crystal
of CaRhSn, which displays second magnetization peak (SMP)
anomaly as distinct from the peak effect (PE). We observe an interesting
modulation in the field dependence of a parameter which purports to measure the
dynamical annealing of the disordered bundles of vortices injected through the
sample edges towards the destined equilibrium vortex state at a given .
These data, in conjunction with the earlier observations made while studying
the thermomagnetic history dependence in in the tracing of the minor
hysteresis loops, imply that the partially disordered state heals towards the
more ordered state between the peak field of the SMP anomaly and the onset
field of the PE. The vortex phase diagram in the given crystal of
CaRhSn has been updated in the context of the notion of the
phase coexistence of the ordered and disordered regions between the onset field
of the SMP anomaly and the spinodal line located just prior to the
irreversibility line. A multi-critical point and a critical point in the
() region of the Bragg glass phase have been marked in this phase diagram
and the observed behaviour is discussed in the light of recent data on
multi-critical point in the vortex phase diagram in a single crystal of Nb.Comment: To appear in Current trends in Vortex State Studies - Pramana J.
Physic
Domain regime in two-dimensional disordered vortex matter
A detailed numerical study of the real space configuration of vortices in
disordered superconductors using 2D London-Langevin model is presented. The
magnetic field is varied between 0 and for various pinning
strengths . For weak pinning, an inhomogeneous disordered vortex matter
is observed, in which the topologically ordered vortex lattice survives in
large domains. The majority of the dislocations in this state are confined to
the grain boundaries/domain walls. Such quasi-ordered configurations are
observed in the intermediate fields, and we refer it as the domain regime (DR).
The DR is distinct from the low-field and the high-fields amorphous regimes
which are characterized by a homogeneous distribution of defects over the
entire system. Analysis of the real space configuration suggests domain wall
roughening as a possible mechanism for the crossover from the DR to the
high-field amorphous regime. The DR also shows a sharp crossover to the high
temperature vortex liquid phase. The domain size distribution and the roughness
exponent of the lattice in the DR are also calculated. The results are compared
with some of the recent Bitter decoration experiments.Comment: 9 pages, 9 figure
Depinning and plasticity of driven disordered lattices
We review in these notes the dynamics of extended condensed matter systesm,
such as vortex lattices in type-II superconductors and charge density waves in
anisotropic metals, driven over quenched disorder. We focus in particular on
the case of strong disorder, where topological defects are generated in the
driven lattice. In this case the repsonse is plastic and the depinning
transition may become discontinuous and hysteretic.Comment: 21 pages, 6 figures. Proceedings the XIX Sitges Conference on
Jamming, Yielding, and Irreversible Deformations in Condensed Matter, Sitges,
Barcelona, Spain, June 14-18, 200
Nonequilibrium Steady States of Driven Periodic Media
We study a periodic medium driven over a random or periodic substrate. Our
work is based on nonequilibrium continuum hydrodynamic equations of motion,
which we derive microscopically. We argue that in the random case instabilities
will always destroy the LRO of the lattice. In most, if not all, cases, the
stable driven ordered state is a transverse smectic, with ordering wavevector
perpendicular to the velocity. It consists of a periodic array of flowing
liquid channels, with transverse displacements and density (``permeation
mode'') as hydrodynamic variables. We present dynamic functional
renormalization group calculations in two and three dimensions for an
approximate model of the smectic. The finite temperature behavior is much less
glassy than in equilibrium, owing to a disorder-driven effective ``heating''
(allowed by the absence of the fluctuation-dissipation theorem). This, in
conjunction with the permeation mode, leads to a fundamentally analytic
transverse response for . Our results are compared to recent experiments
and other theoretical work.Comment: 39 PRB pages, RevTex and 9 postscript figures, uses multicol.st
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