A Novel Generic Framework for Track Fitting in Complex Detector Systems

This paper presents a novel framework for track fitting which is usable in a wide range of experiments, independent of the specific event topology, detector setup, or magnetic field arrangement. This goal is achieved through a completely modular design. Fitting algorithms are implemented as interchangeable modules. At present, the framework contains a validated Kalman filter. Track parameterizations and the routines required to extrapolate the track parameters and their covariance matrices through the experiment are also implemented as interchangeable modules. Different track parameterizations and extrapolation routines can be used simultaneously for fitting of the same physical track. Representations of detector hits are the third modular ingredient to the framework. The hit dimensionality and orientation of planar tracking detectors are not restricted. Tracking information from detectors which do not measure the passage of particles in a fixed physical detector plane, e.g. drift chambers or TPCs, is used without any simplifications. The concept is implemented in a light-weight C++ library called GENFIT, which is available as free software

Optical fibers to measure temperature vertical profile at sea

The paper is focus in the use the optical fiber to measure the temperature in various heigh at the same time to get a temperature vertical variation. The temperature measurements are puntual while the Bragg gratings located in the fiber.Peer Reviewe

Fabrication and Characterization of Multiband Solar Cells Based on Highly Mismatched Alloys

Multiband solar cells are one type of third generation photovoltaic devices in which an increase of the power conversion efficiency is achieved through the absorption of low energy photons while preserving a large band gap that determines the open circuit voltage. The ability to absorb photons from different parts of the solar spectrum originates from the presence of an intermediate energy band located within the band gap of the material. This intermediate band, acting as a stepping stone allows the absorption of low energy photons to transfer electrons from the valence band to the conduction band by a sequential two photons absorption process. It has been demonstrated that highly mismatched alloys offer a potential to be used as a model material system for practical realization of multiband solar cells. Dilute nitride GaAs1-xNx highly mismatched alloy with low mole fraction of N is a prototypical multiband semiconductor with a well-defined intermediate band. Currently, we are using chemical beam epitaxy to synthesize dilute nitride highly mismatched alloys. The materials are characterized by a variety of structural and optical methods to optimize their properties for multiband photovoltaic devices

Validation of potentiometric method to determine the degree of deacetylation of chitosan

Un método potenciométrico para la determinación del grado de desacetilación de muestras de quitosanas derivadas de quitina de langosta se validó según las exigencias internacionales actuales. Para garantizar que ocurriera la reacción completa entre el analito y la disolución de HCl se aplicó calentamiento de las muestras a temperatura inferior a 60ºC. Auxiliarmente a los cambios de pH, para la detección del primer punto de infl exión, se utilizó el anaranjado de metilo como indicador visual cuyo intervalo de transición está en un rango estrecho de pH ácido, entre 2 a 4. No se registraron interferencias desde el punto de vista analítico en la zona de interés de la curva potenciométrica en ausencia del analito, por lo que el método fue selectivo. Se demostró que el método fue lineal en el rango de 10.0 a 15.0 mg/mL, además fue preciso y exacto para la determinación del porcentaje de grupos aminos libres.The purpose of this study was to validate, in accordance with international standards, a potentiometric method to determine the degree of deacetylation of chitosan samples derived from lobster chitin. To ensure a complete reaction between the analyte and the HCl solution, the samples were heated to temperatures of up to 60ºC. The change in pH and the methyl orange method, as a visual indicator were used to detect the fi rst infl ection point. The transition interval fell within the narrow pH acid range of 2 to 4. From an analytical point of view, no interference was observed on the potentiometric curve in the absence of the analyte, thus showing that the method was suffi ciently selective. For the determination of the percentage of free amino groups, the method proved to be linear within the 10.0 to 15.0 mg/mL range, as well as precise and exact

Shear band localization via local J2 continuum damage mechanics

This work describes a novel formulation for the solution of problems involving shear band localization using a local isotropic J2 continuum damage model and mixed linear simplex (triangles and tetrahedral). A simple isotropic local J2 damage constitutive model is considered, either with linear or exponential softening

A mixed Finite Element formulation for incompressibility using linear displacement and pressure interpolations

In this work shall be presented a stabilized finite element method to deal with incompressibility in solid mechanics. A mixed formulation involving pressure and displacement fields is used and a continuous linear interpolation is considered for both fields. To overcome the Ladyzhenskaya-Babuska-Brezzi condition, a stabilization technique based on the orthogonal sub-grid scale method is introduced. The main advantage of the method is the possibility of using linear triangular finite elements, which are easy to generate for real industrial applications. Results are compared with several improved formulations, as the enhanced assumed strain method (EAS) and the Q1P0-formulation, in nearly incompressible problems and in the context of linear elasticity and J2-plasticity