Alvaro Hernan Bedoya Calle

Using X-ray diffraction (XRD), UV-Visible spectroscopy, XPS and photoluminescence (PL) measurements, the structural, optical and electronic properties of ZnO and Ce-doped ZnO thin films were investigated; the films were deposited on glass substrates by RF reactive-magnetron sputtering and post-annealed at 300C in an oxygen atmosphere. Under simila...

In2O3 thin films with a top layer of SnO2 were deposited onto glass substrates by DC reactive-magnetron sputtering. After deposition, In2O3/SnO2 samples were annealed in vacuum at 400oC. Structural, optical, and chemical composition was investigated by X-ray diffraction, UV-Vis spectroscopy and XPS, respectively. X-ray data showed that films grow p...

The following explicit model, valid for high aperture refraction with homogenous and isotropic materials, encompasses all explicit solutions of the first-order nonlinear differential equation representing the perfect image-forming process of any axial object point into its axial image point. Solutions include well-known cases, such as flats, sphere...

In this study, we address three key challenges in photonic crystals: modeling of isolated flat bands, electric field prediction, and band separation in dispersion relations. Using twisted square Bravais lattices at specific angles, we create Bravais-Moiré photonic crystals exhibiting unique characteristics. These include band pairing and parallelis...

Betanidin (Bd) is a nitrogenous metabolite with significant bioactive potential influenced by pH. Its free radical scavenging activity and deprotonation pathway are crucial to studying its physicochemical properties. Motivated by the published discrepancies about the best deprotonation routes in Bd, this work explores all possible pathways for prot...

Automatic search of cavities and binding mode analysis between a ligand and a 3D protein receptor are challenging problems in drug design or repositioning. We propose a solution based on a shape theory theorem for an invariant coupled system of ligand-protein. The theorem provides a matrix representation with the exact formulas to be implemented in...

Betanin and betanidin are compounds with extensive interest; they are effectively free radical scavengers. The present work aims to elucidate the differences between the mechanism of the antioxidant activity of betanin, betanidin, and their respective C15-epimers. Shape Theory establishes comparisons between the molecules’ geometries and determines...

We report tunable RF-sputtered AZO nanoflms through of deposition conditions. Perfect adsorption of light was simulated in ENZ mode. The coupling condition of thickness and wavelength in perfect absorption was obtained by a Drude model. The ftted parameters range as follows: charge density, from 1.6 × 1020 to 4.4 × 1020 cm−3; mobilities, from 8.23...

We present the synthesis of lanthanum nitrate nanoparticles via the polyol method. A crystallographic study of La(NO 3) 3 · 4H 2 O nanoparticles was carried out using the Rietveld method and XRD to detect the phases of the yield: α (monoclinic) and β (orthorhombic) phases were obtained. Thermogravimetric analysis showed a unique dehydration process...

Structural and optelectronic properties of ZnO and Ce-doped ZnO films deposited on glass substrates by RF reactivemagnetron sputtering, and later annealed at 300ºC into an oxygen atmosphere, were studied using X-ray diffraction (XRD), UV-Visible spectroscopy, XPS, and photoluminescence (PL) measurements. Under similar deposition conditions, both fi...

ZnO thin films were deposited on glass substrates using a RF magnetron sputtering. From the transmittance spectra and dielectric Drude-Lorentz model was used to obtain the optoelectronic properties.

Journal of Nano Research Vol. 30; Table of Contents; Electrical Properties of Copper Oxide Nanoparticles; Mechanical Properties of Epoxy Nanocomposites Using Alumina as Reinforcement -- A Review; Self-Cleaning TiO2 Nanofilms on FTO Glass: Influence of Electrophoretic Deposition and UV Irradiation Conditions; Nitrogen-Doped Carbon Nanotubes and Grap...

Zinc oxide films were deposited on glass substrates by RF reactive magnetron sputtering and post-annealed in vacuum at 100, 200, and 300 ºC. Structural and optical properties of films were obtained using X-ray diffraction and UV–visible spectroscopy. Optical parameters were extracted from transmittance curves using the single-oscillator Drude–Loren...

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Los óxidos transparentes conductores (TCO′ s) son materiales compuestos conformados por oxígeno y un metal, que presentan una combinación única de alta estabilidad química, alta concentración electrónica y alta transparencia óptica. Por esta razón, el procesamiento de TCO′ s en película delgada va orientado hacia aplicaciones específicas tales como...

Study of optical and microestructural properties in In2O3 and SnO2 multilayer thin films synthesis by DC magnetron sputtering characterized with SEM, X-RD and four point probe resistivity where is possible appreciate an enhancement in conductivity.

Study of optical and microestructural properties in In2O3 and SnO2 multilayer thin films synthesis by DC magnetron sputtering characterized with SEM, X-RD and four point probe resistivity where is possible appreciate an enhancement in conductivity.

La presente invención se refiere a un conjunto de lentes asféricas ovales que presentan cero aberración esférica, las cuales se pueden representar por medio de funciones matemáticas explicitas que permiten calcular los espesores de las lentes de manera exacta, evitando así el uso de las series aproximadas que se emplean en la industria óptica para...

Se presenta a continuación un modelo matemático riguroso del ojo humano que permite modelar de la manera más precisa el comportamiento del sistema óptico para su uso práctico en oftalmología, optometría e ingeniería óptica. El modelo presentado se fundamenta en análisis físicos, matemáticos y estadísticos para obtener toda la información geométrica...

Se presentan tres modelos matemáticos para la regresión y correlación de una nube de N puntos en R3 con coordenadas cartesianas xj, yj como abscisas, con su respectiva ordenada ri como radio de curvatura de la sección axial o sagital, pero que no corresponde a la curvatura gaussiana, con un paraboloide, elipsoide e hiperboloide de revolución en for...

Se presenta a continuación la creación de funciones trigonométricas especiales, con base en la geometría elíptica en coordenadas cartesianas y polares, que permiten describir una torsión del plano polar, para caracterizar variables físicas, con muchas aplicaciones en la industria electrónica, ya también para: modelar distribuciones de probabilidad...

Three mathematical models are presented for the regression and correlation of a cloud of N points in R3 with Cartesian coordinates xj, yj as abscissas, with his respective ordinate ri as a radius of curvature of the axial or sagittal section, but not corresponding to the Gaussian curvature, with a paraboloid, ellipsoid, and hyperboloid of revolutio...

This paper presents the method to obtain, in Cartesian coordinates, the parallel curve lines of non-degenerate conical curves, by analytical and numerical methods. Offset is defined as parallel function to the original function to a distance r. Offset of a conic is important for the manufacturing processes of mechanisms, lenses, mirrors, and molds;...

Este artículo presenta el método para obtener, en coordenadas cartesianas, las líneas curvas paralelas de las curvas cónicas no degeneradas, por métodos analíticos y numéricos. Se define el offset como una función paralela a la función original a una distancia r. El offset de una cónica es importante para los procesos de fabricación de mecanismos,...