9,957 research outputs found
Analysis of the velocity field of granular hopper flow
We report the analysis of radial characteristics of the flow of granular
material through a conical hopper. The discharge is simulated for various
orifice sizes and hopper opening angles. Velocity profiles are measured along
two radial lines from the hopper cone vertex: along the main axis of the cone
and along its wall. An approximate power law dependence on the distance from
the orifice is observed for both profiles, although differences between them
can be noted. In order to quantify these differences, we propose a Local Mass
Flow index that is a promising tool in the direction of a more reliable
classification of the flow regimes in hoppers
Edible coatings from galactomannans and their application to tropical fruits
Edible coatings play an important role in the quality and in the resistance to transportation, storage and display of a wide range of fresh and processed foods. Polysaccharide coatings with an oil-free appearance and low caloric content can be used to increase the shelf life of fresh fruits, since they allow the modification of the internal gas composition of fruits, retarding their senescence. The objective of this work was to study the ability of seed galactomannans, with different manose:galactose relation, from the Leguminosae Caesalpinea pulcherrima (2.8:1) and Adenanthera pavonina (2:1) as coatings to extend the shelf life of acerola (Malpighia emarginata), cajá (Spondias lutea), mango (Mangifera indica), pitanga (Eugenia uniflora) and sirigüela (Spondias purpurea). Fresh fruits surface properties, galactomannans relative viscosity as well as the wetting capacity of the coatings were determined. Galactomannans were obtained from seed endosperm and their toxicological safety was determined by oral administration to Wistar adult rats. No toxic effects were detected. Blends with different galactomannan:glycerol proportions were tested as coatings. The blends wettability was determined by the spreading coefficient using the sessile-drop method. The best proportions of galactomannan/glycerol were determined for coatings of C.pulcherrima and A.pavonina in the various fruits tested.Fundação para a Ciência e a Tecnologia (FCT) ; Alfa-Valnatura; CNPq; CAPES; FUNCAP.Alfa-Valnatur
Analysis of parameter-independent PLLs with bang-bang phase-detectors
The parameter-independent design of Phase-Locked Loops (PLLs) is investigated for the case that a bang-bang phase-detector is used. Two self-biased CMOS PLL structures are proposed and compared, one l eading to a completely parameter- and frequency independent behavior. If the PLL frequency operation is constant and known in advance, however, both structures can be made independent of the transisto r Vt and b parameters
Obtenção de adultos e aspectos biológicos da broca-do-mamoeiro, Pseudopiazurus obesus (GOHEMAN, 1838) (Coleoptera: Curculionidade).
bitstream/CPATC/19910/1/bp-32.pd
Protein intake and obesity in schoolchildren
[resumo]Resumo de comunicação apresentada em: 16th European Congress on Obesity - ECO 2008; 2008 Mai 14-17; Genebra, SuÃça
Spin-phonon coupling in multiferroic RCrO (R-Y, Lu, Gd, Eu, Sm): A Raman study
Raman study on a select few orthochromites, RCrO (R = Y, Lu, Gd, Eu and
Sm) shows that the phonon behavior at TN in compounds with magnetic R-ion (Gd
and Sm) is remarkably different from that of non-magnetic R-ion (Y, Lu and Eu).
While anomalies in most of the observed phonon frequencies in all these
compounds may result from the distortion of CrO octahedra due to size
effect and magnetostriction arising from Cr-ordering, the anomalous behavior of
their linewidths observed at TN for the compounds with only magnetic R-ion
suggests spin-phonon coupling. The presence of spin-phonon coupling and the
anomalies in the low frequency modes related to R-ion motion in orthochromites
(R = Gd and Sm) support the suggestion that the coupling between 4f-3d moments
play important role in inducing switchable electric polarization.Comment: 6 pages (two column format), 7 figures; The updated version of the
manuscript can be found at Euro. Phys. Lett. 101, 17008 (2013
Atratividade dos compostos feromonais na captura da broca-do-mamoeiro Pseudopiazurus obesus (Boheman, 1838) (Coleoptera: Curculionidae) em condições de campo.
bitstream/CPATC/19909/1/bp-31.pd
Structural and insulator-to-metal phase transition at 50 GPa in GdMnO3
We present a study of the effect of very high pressure on the orthorhombic
perovskite GdMnO3 by Raman spectroscopy and synchrotron x-ray diffraction up to
53.2 GPa. The experimental results yield a structural and insulator-to-metal
phase transition close to 50 GPa, from an orthorhombic to a metrically cubic
structure. The phase transition is of first order with a pressure hysteresis of
about 6 GPa. The observed behavior under very high pressure might well be a
general feature in rare-earth manganites.Comment: 4 pages, 3 figures and 2 table
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