7,001 research outputs found
Redundancy of stereoscopic images: Experimental Evaluation
With the recent advancement in visualization devices over the last years, we
are seeing a growing market for stereoscopic content. In order to convey 3D
content by means of stereoscopic displays, one needs to transmit and display at
least 2 points of view of the video content. This has profound implications on
the resources required to transmit the content, as well as demands on the
complexity of the visualization system. It is known that stereoscopic images
are redundant, which may prove useful for compression and may have positive
effect on the construction of the visualization device. In this paper we
describe an experimental evaluation of data redundancy in color stereoscopic
images. In the experiments with computer generated and real life and test
stereo images, several observers visually tested the stereopsis threshold and
accuracy of parallax measuring in anaglyphs and stereograms as functions of the
blur degree of one of two stereo images and color saturation threshold in one
of two stereo images for which full color 3D perception with no visible color
degradations is maintained. The experiments support a theoretical estimate that
one has to add, to data required to reproduce one of two stereoscopic images,
only several percents of that amount of data in order to achieve stereoscopic
perception
Long-distance entanglement and quantum teleportation in XX spin chains
Isotropic XX models of one-dimensional spin-1/2 chains are investigated with
the aim to elucidate the formal structure and the physical properties that
allow these systems to act as channels for long-distance, high-fidelity quantum
teleportation. We introduce two types of models: I) open, dimerized XX chains,
and II) open XX chains with small end bonds. For both models we obtain the
exact expressions for the end-to-end correlations and the scaling of the energy
gap with the length of the chain. We determine the end-to-end concurrence and
show that model I) supports true long-distance entanglement at zero
temperature, while model II) supports {\it ``quasi long-distance''}
entanglement that slowly falls off with the size of the chain. Due to the
different scalings of the gaps, respectively exponential for model I) and
algebraic in model II), we demonstrate that the latter allows for efficient
qubit teleportation with high fidelity in sufficiently long chains even at
moderately low temperatures.Comment: 9 pages, 6 figure
On Higher Derivatives as Constraints in Field Theory: a Geometric Perspective
We formalize geometrically the idea that the (de Donder) Hamiltonian
formulation of a higher derivative Lagrangian field theory can be constructed
understanding the latter as a first derivative theory subjected to constraints.Comment: 7 page
Synthesis of a Plant-based Dust Suppressant and Testing on Coal from Moatize, Mozambique
The dust suppressant was synthesized using Pinus elliottii resin as raw material for the new plant-based formulation. The dust suppressant formulation was prepared by solubilizing rosin in a ternary solution containing calcium chloride, ultrapure water, and ethanol in a molar ratio of 1:2:8. After centrifugation the supernatant was collected, 20 mL of 2 % γ-polyglutamic acid dissolved in an aqueous ethanol solution was added, and the mixture was stirred for 2 hours. The dust suppressant formulation included Pinus extract and γ-PGA acid, resulting in a plant-based dust suppressant. The performance of the new formulation in reducing PM10 was significantly superior (82.7 %) to that of water. This suppressant is suitable for spraying onto coal ore piles and hopper cars carrying coal ore. The wettability of the product was analyzed by the Walker test, which confirmed its adhesiveness to coal dust.
This work is licensed under a Creative Commons Attribution 4.0 International License
Cell death induced by the application of alternating magnetic fields to nanoparticle-loaded dendritic cells
In this work, the capability of primary, monocyte-derived dendritic cells
(DCs) to uptake iron oxide magnetic nanoparticles (MNPs) is assessed and a
strategy to induce selective cell death in these MNP-loaded DCs using external
alternating magnetic fields (AMFs) is reported. No significant decrease in the
cell viability of MNP-loaded DCs, compared to the control samples, was observed
after five days of culture. The amount of MNPs incorporated into the cytoplasm
was measured by magnetometry, which confirmed that 1 to 5 pg of the particles
were uploaded per cell. The intracellular distribution of these MNPs, assessed
by transmission electron microscopy, was found to be primarily inside the
endosomic structures. These cells were then subjected to an AMF for 30 min, and
the viability of the blank DCs (i.e., without MNPs), which were used as control
samples, remained essentially unaffected. However, a remarkable decrease of
viability from approximately 90% to 2-5% of DCs previously loaded with MNPs was
observed after the same 30 min exposure to an AMF. The same results were
obtained using MNPs having either positive (NH2+) or negative (COOH-) surface
functional groups. In spite of the massive cell death induced by application of
AMF to MNP-loaded DCs, the amount of incorporated magnetic particles did not
raise the temperature of the cell culture. Clear morphological changes at the
cell structure after magnetic field application were observed using scanning
electron microscopy. Therefore, local damage produced by the MNPs could be the
main mechanism for the selective cell death of MNP-loaded DCs under an AMF.
Based on the ability of these cells to evade the reticuloendothelial system,
these complexes combined with an AMF should be considered as a potentially
powerful tool for tumour therapy.Comment: In Press. 33 pages, 11 figure
Efeitos salinos no crescimento e desenvolvimento do arroz: alterações fisiológicas.
Com o objetivo de avaliar os efeitos do NaCl sobre o desenvolvimento vegetativo de plantas de arroz (Oryza sativa L.) (cultivar IAC 25, um experimento foi conduzido em casa de vegetação no Centro de Ciências Agrárias da Universidade Federal do Ceará, em Fortaleza, CE. Sob os potenciais osmóticos de 0,0, -0,4, -0,8 e -1,2 MPa de NaCl, foram avaliados o peso da matéria seca da parte aérea e da raiz, o peso da matéria seca total, a relação raiz/parte aérea, o volume e o comprimento das raízes, o número de perfilhos por planta e transpiração/ planta/dia. O aumento da concentração salina provocou reduções significativas no peso da matéria seca da parte aérea. O comprimento e o volume das raízes foram reduzidos significativamente com o aumento do teor de NaCl na solução nutritiva. O número de perfilhos/planta, mesmo sendo uma característica genética, sofreu redução significativa com o aumento da concentração de NaCl. O aumento do nível salino reduziu o volume de água transpirado, principalmente nos tratamentos com potenciais osmóticos de -0,4 MPa. A salinização do meio de cultivo provocou envelhecimento precoce nas plantas de arroz
Cultivo de milho-verde consorciado com plantas aromáticas no agreste de Sergipe, sob manejo orgânico.
bitstream/item/68648/1/cot-119.pd
Marcador bioquímico para seleção de genótipos de milho tolerantes ao alumínio.
xSuplemento. Edição dos resumos do IX Congresso Brasileiro de Fisiologia Vegetal, 2003, Atibaia, SP
Hot and repulsive traffic flow
We study a message passing model, applicable also to traffic problems. The
model is implemented in a discrete lattice, where particles move towards their
destination, with fluctuations around the minimal distance path. A repulsive
interaction between particles is introduced in order to avoid the appearance of
traffic jam. We have studied the parameter space finding regions of fluid
traffic, and saturated ones, being separated by abrupt changes. The improvement
of the system performance is also explored, by the introduction of a
non-constant potential acting on the particles. Finally, we deal with the
behavior of the system when temporary failures in the transmission occurs.Comment: 22 pages, uuencoded gzipped postscript file. 11 figures include
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