Search results for "Homogeneous"

Depth Enhancement by Fusion for Passive and Active Sensing

2012

This paper presents a general refinement procedure that enhances any given depth map obtained by passive or active sensing. Given a depth map, either estimated by triangulation methods or directly provided by the sensing system, and its corresponding 2-D image, we correct the depth values by separately treating regions with undesired effects such as empty holes, texture copying or edge blurring due to homogeneous regions, occlusions, and shadowing. In this work, we use recent depth enhancement filters intended for Time-of-Flight cameras, and adapt them to alternative depth sensing modalities, both active using an RGB-D camera and passive using a dense stereo camera. To that end, we propose …

Über die Verwendung von homogenen azeotropen Gemischen in der Dünschichtchromatographie, 1. Mitt.

1968

Homogene azeotrope Gemische wurden auf ihre Brauchbarkeit fur die Dunnschichtchromatographie untersucht. Mehrere Gemische zeigten sich zur Trennung verschiedener Substanzklassen, z. B. Alkaloiden oder Sulfonamiden geeignet. Die DC mit diesen Gemischen fuhrt zu besonders konstanten Rf-Werten und zeichnet sich durch Wirtschaftlichkeit aus. The usefulness of homogeneous azeotropic mixtures in thin layer chromatography has been studied. Several mixtures are qualified for the separation of different classes of substances, for example alkaloids and sulfonamides. TLC with azeotropic solvents leads to especially constant Rf-values and is remarkably economical.

Prediction of the carbon-13 NMR chemical shifts of polysubstituted benzenes with homogeneous substituents

1991

A new incremental scheme for the calculation of the 13C NMR chemical shifts in polysubstituted benzenes with homogeneous substituents was derived and applied to spectral prediction for C6XnH6−n where XCH3, C2H5, i-C3H7, CF3, F, Cl, Br, COOH. Owing to the use of only two-particle increments the procedure is simple enough to be carried out on hand calculators, and gives complete agreement with experimental values within a few tenths of a ppm in all cases compared (76 compounds). The 13C NMR chemical shift was predicted for hexaethylbenzene with a good fit to the experiment value, and also for 20 unmeasured compounds. The present scheme can be used as an algorithm in structure-searching progra…

Quasiconformally Bi-Homogeneous Compacta in the Complex Plane

1999

Coordinación docente y precariedad. Modelos de coordinación en la enseñanza de la Sociología en Andalucía

2021

espanolDesde la implantacion de los Sistemas de Garantia de Calidad, la ensenanza universitaria ha incorporado mecanismos y figuras de coordinacion a la practica docente. Sin embargo, su aplicacion dista de ser homogenea. Un mecanismo disenado originalmente para la mejora de la calidad docente ha cobrado una nueva significacion e importancia debido al contexto de precarizacion generalizada de las plantillas de profesorado en la universidad. Este trabajo plantea un analisis del contexto, las bases teoricas y los distintos modelos de coordinacion implementados en una serie de universidades donde se imparte el grado de Sociologia en Andalucia, pero los resultados son perfectamente extrapolable…

Vibrational Signature of Water Molecules in Asymmetric Hydrogen Bonding Environments

2013

The O–H stretching vibrational modes of water molecules are sensitive to their local environments. Here, we applied effective normal-mode analysis to isolate contributions of each of the two hydrogen atoms to the vibrational modes ν1 and ν3 of water molecules in the liquid phase. We demonstrate that the decoupling of the two contributions fd and the frequency splitting of the vibrational modes Δω13 are inextricably related to the symmetry of the hydrogen bonding environment. We show that ambient liquid water modeled at the density functional level of theory exhibits the characteristics of an asymmetric environment with an average decoupling of 0.82 and a splitting of 137 inverse centimeters…

Die Herstellung einer molekulareinheitlichen Tetramethacrylsäure mittels verschiedener Matrizen. VI. Mitt. Modelle für Matrizenreaktionen

1968

Es wurde aus einer phenolischen Zweikernverbindung eine cyclische Verbindung IV hergestellt, die bei der alkalischen Hydrolyse eine molekulareinheitliche Tetramethacrylsaure (VII) und die phenolische Ausgangsverbindung gab. Die Synthese der gleichen Saure (VII) gelang auch mit strukturell verschiedenen Zweikernverbindungen, wenn nur bei den verwendeten Matrizen der innermolekulare Abstand der beiden phenolischen Hydroxylgruppen fur die Reaktion gunstig war. Alkaline hydrolysis of a cyclic compound (IV) which was prepared out of a dinuclear phenolic compound gave a molecularly homogeneous tetra-methacrylic acid (VII) and the original phenolic compound. The synthesis of the same acid could al…

Synthesis, reactivity, crystal structures and catalytic activity of new chelating bisimidazolium-carbene complexes of Rh

2003

A series of new bridging, chelating and pincer N-heterocyclic carbenes of RhI and RhIII have been obtained under mild conditions. The compounds have been fully characterised and their crystal structures determined. The chelate-pincer coordination of the ligands means that the stability of these compounds is significantly greater than other carbene complexes of Rh. The compounds have been tested in catalytic reactions such as hydrogen transfer from alcohols to ketones, and hydrosilylation of terminal olefins and alkynes; they show a high activity for both processes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

ω-hypoelliptic differential operators of constant strength

2004

Abstract We study ω-hypoelliptic differential operators of constant strength. We show that any operator with constant strength and coefficients in E ω (Ω) which is homogeneous ω-hypoelliptic is also σ-hypoelliptic for any weight function σ=O(ω). We also present a sufficient condition in order to ensure that a differential operator admits a parametrix and, as a consequence, we obtain some conditions on the weights (ω,σ) to conclude that, for any operator P(x,D) with constant strength, the σ-hypoellipticity of the frozen operator P(x0,D) implies the ω-hypoellipticity of P(x,D). This requires the use of pseudodifferential operators.

Bòvedas tabicadas: experimental and numerical analysis

2008

A class of thin vaults, the so-called “bovedas tabicadas”, which represent one of the most common Spanish traditional building techniques at the end of XIX century are studied here, treating the relevant analysis problem through a numerical, as well as an experimental, approach. At first the problem is studied by searching for the behaviour of the material effecting suitable experiments. Once the constitutive behaviour of the materials and the structural elements are experimentally characterized, a semi inverse method for the identification of the optimum mechanical parameters to assign to an equivalent homogeneous ideal material through analysis reproducing the executed experimental tests …