1,343 research outputs found
Adquisición y visualización de vídeo 3D
La visualización de imágenes en 3D es posible gracias a los sistemas estereoscópicos, que nos permiten capturar diferentes vistas de una misma escena y mediante el procesado de estas se consigue extraer información de profundidad que nos permite realizar el efecto. El sistema estereoscópico está formado por dos cámaras convencionales situadas a una distancia de unos 65mm con el fin de simular la vista humana. El objetivo de este proyecto es realizar un sistema estereoscópico y procesar las imágenes obtenidas por este sistema, para finalmente lograr el efecto 3D. Esto lo logramos por medio de un proceso de calibración mediante los parámetros intrínsecos (internos de la cámara) y extrínsecos (informan de la rotación y traslación de los ejes de referencia de las cámaras respecto a los de la escena), conseguidos a través de imágenes controladas. Este proceso es conocido como rectificación del par estéreo y consiste en alinear los puntos de las dos vistas de modo que consigamos tener una correspondencia entre las dos vistas y la escena. Una vez calibrado el sistema estereoscópico se procesan las imágenes para visualizarlas en diferentes modos: anaglífico (método de visualización directa) y Side by Side (método que requiere de procesado y dispositivos necesarios para visualizar mediante la técnica de secuencia de frames alternados). Por tanto, se obtienen diferentes modos de visualización para su posterior transmisión, objetivo de otros TFC. El sistema estereoscópico es la fase inicial de un sistema completo de transmisión de imágenes, el cual dará el flujo de entrada con las posibilidades anteriormente expuestas. El sistema completo está compuesto por las siguientes fases: adquisición, codificación, transmisión, decodificación y visualización de imágenes en tres dimensiones
On the Effect of Synthetic and Real Data Properties on Seismic Intensity Prediction Equations
The present investigation focuses on the effect of input data properties on the estimation of seismic intensity prediction equation (IPE) coefficients. Emphasis is placed on small-tomoderate magnitude earthquakes. Synthetic intensity data points (IDPs) are created using a given IPE, assuming independence of azimuth. Extensive simulations are performed for single earthquakes and a synthetic database. Tests of single earthquakes show that increasing the sample size narrows the range of obtained coefficients. The larger the difference between the shortest and longest distance of IDPs from the epicentre, the narrower is this range. A short radius of perceptibility is more rapidly saturated with new data points than a long one. The synthetic database is used to examine the effect of magnitude and depth errors. The performance of synthetic data gives a model with which the real data can be compared. The attenuation coefficient appears stable against magnitude errors of +/- 0.2 units, but starts to be overestimated as magnitude errors increase. Assuming an erroneous regional depth easily leads to intensity differences of 1 degree. The mean coefficient values deviate from the correct ones and tend to increase with depth. The results resemble the synthetic ones, but imply larger uncertainties. The attenuation coefficient, m, appears to be the least sensitive coefficient to errors. Real data from seven post-1965 earthquakes in the magnitude range of 4.0-5.2 were retrieved from the intensity database of the United Kingdom.Peer reviewe
Homoallylic o-halobenzylamines: asymmetric diversity-oriented synthesis of benzo-fused cyclic amines
The presence of a halogen atom in the proximity of a homoallylic amine, obtained by asymmetric addition of allylzinc bromide to the corresponding tert-butyl sulfinimine, makes them versatile building blocks suitable to participate in several palladium-catalyzed processes, such as the intramolecular Heck reaction or the Sonogashira cross-coupling. The thus obtained orthoalkynyl derivatives display two unsaturated functional groups which may be further modified by means of the intramolecular Pauson–Khand reaction or the ring-closing enyne metathesis. In this way, a variety of benzo-fused amines can be obtained in 2–3 steps from readily available starting materials
Correlaciones entre la Radiación Solar, sus Componentes, el Ángulo de Montaje y la Generación de los Módulos Fotovoltaicos
Se midió durante un año la energía generada por cuatro módulos fotovoltaicos de 42 Wp montados a diferentes ángulos respecto al plano horizontal, y las radiaciones difusa y global. Se calculó la generación de energía mensual y anual, encontrándose los ángulos óptimos mensuales y anuales para máxima generación de energía. Se analizó la composición de la radiación en función de las características del clima y su incidencia en la eficiencia de conversión de los módulos.Fil: Cutrera, Miriam Edith. Universidad Nacional del Litoral; ArgentinaFil: Battioni, Mario Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Risso, Gustavo Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Buitrago, Roman Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin
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Five mononuclear pentacoordinate Co(II) complexes with field-induced slow magnetic relaxation
Five related mononuclear pentacoordinate complexes of the formula [CoL³Cl2] show slow magnetic relaxation under small applied DC field; L³ – a tridentate N-donor ligand based upon dipyrazolpyridine with an alkyl tail. All of them exhibit a supramolecular assembly, either forming dimers or chains via π–π stacking. Moreover, they display two relaxation branches, one being typical for single molecule magnets of this class, τ ∼ 10−6 s, and the second one as slow as τ ∼ 0.5 s at T = 1.9 K
A Tetranuclear Dysprosium Schiff Base Complex Showing Slow Relaxation of Magnetization
A tetranuclear dysprosium Schiff base complex was isolated by reacting dysprosium chloride with 2-hydroxy-3-methoxybenzaldehyde and 2-(aminomethyl)pyridine in-situ under basic conditions. The isolated Dy(III) complex was characterized by elemental analyses, single crystal X-ray diffraction and molecular spectroscopy. The complex crystallizes in the triclinic space group P-1 with unit cell parameters of a = 10.2003 (4), b = 13.8602 (5), c = 14.9542 (6), α = 94.523 (3), β = 109.362 (4), and γ = 99.861 (3). The magnetic properties of 1 have been investigated by DC and AC susceptibility measurements. The DC measurements reveal weak exchange coupling of antiferromagnetic nature. In the AC measurement, the complex shows a slow relaxation of magnetization in the absence of an external magnetic field
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Mixed-meal tolerance test to assess residual beta-cell secretion: Beyond the area-under-curve of plasma C-peptide concentration.
AIMS: Residual beta-cell secretion in type 1 diabetes is commonly assessed by area-under-curve of plasma C-peptide concentration (AUCCpep ) following mixed-meal tolerance test (MMTT). We aimed to investigate alternative measures of beta-cell responsiveness. METHODS: We analyzed data from 32 youth (age 7 to 17 years) undergoing MMTT within 6 months of type 1 diabetes diagnosis. We related AUCCpep with (a) validated mechanistic index of postprandial beta-cell responsiveness MI accounting for glucose level during MMTT, and (b) pragmatic marker calculated as baseline plasma C-peptide concentration corrected for baseline plasma glucose concentration. RESULTS: Postprandial responsiveness MI was correlated with age and BMI SDS (Rs = 0.66 and 0.44, P < 0.01 and P < 0.05) and was more correlated with glycated hemoglobin than AUCCpep (Rs = 0.79, P = 0.04). The pragmatic marker was highly correlated with AUCCpep (Rs = 0.94, P < 0.01). CONCLUSIONS: Postprandial responsiveness MI may be more relevant to glucose control than AUCCpep . Baseline C-peptide corrected for baseline glucose appears to be a suitable surrogate of AUCCpep if MMTT is not performed
Observing repetitive finger movements modulates response times of auditorily cued finger movements
Our motor and perceptual representations of actions seem to be intimately linked and the human mirror neuron system (MNS) has been proposed as the mediator. In two experiments, we presented biological or non-biological movement stimuli that were either congruent or incongruent to a required response prompted by a tone. When the tone occurred with the onset of the last movement in a series, i.e., it was perceived during the movement presentation, congruent biological stimuli resulted in faster reaction times than congruent non-biological stimuli. The opposite was observed for incongruent stimuli. When the tone was presented after visual movement stimulation, however, no such interaction was present. This implies that biological movement stimuli only affect motor behaviour during visual processing but not thereafter. These data suggest that the MNS is an “online” system; longstanding repetitive visual stimulation (Experiment 1) has no benefit in comparison to only one or two repetitions (Experiment 2)
Field-Induced Single Molecule Magnetic Behavior of Mononuclear Cobalt(II) Schiff Base Complex Derived from 5-Bromo Vanillin
A mononuclear Co(II) complex of a Schiff base ligand derived from 5-Bromo-vanillin and 4-aminoantipyrine, that has a compressed tetragonal bipyramidal geometry and exhibiting field-induced slow magnetic relaxation, has been synthesized and characterized by single crystal X-ray diffraction, elemental analysis and molecular spectroscopy. In the crystal packing, a hydrogen-bonded dimer structural topology has been observed with two distinct metal centers having slightly different bond parameters. The complex has been further investigated for its magnetic nature on a SQUID magnetometer. The DC magnetic data confirm that the complex behaves as a typical S = 3/2 spin system with a sizable axial zero-field splitting parameter D/hc = 38 cm⁻¹. The AC susceptibility data reveal that the relaxation time for the single-mode relaxation process is τ = 0.16(1) ms at T = 2.0 K and BDC = 0.12 T
Effect of gelled inner aqueous phase rheology on the colour degradation of muitle aqueous extracts incorporated into water-in-oil-in-water double emulsions
The aim of this work was to study different W1/O/W2 double emulsions in preserving color muitle aqueous extract (MAE), for which the work was divided into two fold, formulation and analysis of primary emulsion W1/O and W1/O/W2 double emulsions. Sodium alginate (SA), xanthan gum, guar gum, locust bean gum were used as gelling agents of MAE, and it was found that SA produced inner aqueous phase with enhanced viscoelastic properties, resulting in a W1/O primary emulsion with more uniform mean droplet size and distribution than when using the other gelling agents or ungelled MAE. Subsequently W1/O/W2 double emulsions were produced containing MAE gelled with SA or ungelled in the inner aqueous phase stabilized using pure gum Arabic (GA) or a blend of GA-mesquite gum (MG) in a 70:30 ratio in the outer aqueous phase. The double emulsion formulated with gelled MAE and 70:30 GA-MG blend exhibited more uniform mean inner water and outer oil droplet sizes, and protected best the anthocyanins contained in MAE to preserve its color when exposed to 8 h sunlight, providing a half-time life (t1/2) of 55.23 h. The double emulsion formulated with ungelled MAE and stabilized with pure GA displayed a t1/2 of 7.40 h. Keywords: double emulsions, muitle aqueous extract, gelling agents, viscoelastic properties, droplet size, half-time life
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