A GNU library for high order boudary integral equation methods in electromagnetism

In this talk we will present a GNU library made by The Simons Foundation, Inc (Leslie Greengard and Manas Racch), Michael O’Neil, Felipe Vico and others. The library can be downloaded from https://fastalgorithms.github.io/ and consist of a set of functions for the high order discretization of integral equations in electromagnetism. We will explain the main functionalities and interfaces available. The source code is made in fortran and there are wrappers from Matlab, Python, C and other high order languages. The surface geometry is provided by using high order triangular patches and the induced densities on the surface are described by using Koorwninder orthogonal polynomials. The functions provided allow to compute the field on the surface by using a multilevel fast multipole algorithm that is stable in low frequency and a fast adaptive quadrature algorithm for the near interaction terms. The EM formulations provided are: the decoupled potential integral equation (DPIE), the non-resonant chargecurrent integral equation (NRCCIE) and the regularized combined source integral equation (RCSIE). Those formulations are particularly interesting in the low frequency regime due to its stability but can be also used in higher frequencies. The library uses openmp for paralelization and explicit SIMD vectorization for the evaluation of the near field in the adaptive quadrature algorithm. The resulting algorithms don’t suffer from high density mesh breakdown, instead the user can obtain arbitrarily low errors by doing hp refinement (reducing the size of the triangles and increasing the order of the polynomials on each triangle). The formulations allow also adaptive discretizations for geometries with small details. The talk will include a quick user’s guide to the library and interfaces and its installation process in different platforms. We will also show different numerical results. The library also contains low level functions that allow to implement easily other EM formulations or the use of different basis/test functions easily making use of all the adaptive integration and FMM machinery

Procedimiento de fermentación dirigida secuencial, nueva cepa de levadura que interviene en el mismo, y su aplicación industrial

Número de publicación: ES2222786 A1 (01.02.2005) También publicado como: ES2222786 B1 (01.04.2006) Número de Solicitud: Consulta de Expedientes OEPM (C.E.O.) P200202743 (28.11.2002)La presente invención se refiere a una nueva cepa de Pichia fermentans, CECT 11773, y a la aplicación de un nuevo procedimiento de vinificación mediante fermentación secuencial dirigida, por el cual el mosto es sembrado en tiempos diferentes por dicha cepa y por otra del género Saccharomyces. La primera da lugar a la síntesis de una gran cantidad de sustancias aromáticas y saborizantes con baja producción de etanol, que determinarán el aroma del producto final; la segunda levadura se encarga de terminar la fermentación aumentando la cantidad de alcohol acumulado hasta un 12-13% v/v.Universidad de Almerí

Sistema enzimático y procedimiento para la preparación de d-aminoacidos o derivados de los mismos

Número de publicación: ES2241394 A1 (16.10.2005) También publicado como: ES2241394 B1 (16.12.2006) Número de Solicitud: Consulta de Expedientes OEPM (C.E.O.) P200202208 (30.09.2002)La presente invención se refiere a un procedimiento para la preparación de D-aminoácidos o derivados de D-aminoácidos, a partir de mezclas racémicas de D,L-hidantoinas caracterizado por estar constituido por las enzimas hidantoín racemasa, D-hidantoinasa y D-carbomilasa; y a un sistema enzimático de utilidad en dicho procedimiento que cataliza la conversión estereoselectiva de D-5-hidantoina hasta D-aminoácido y la racemización entre los enantiómeros de la misma.Universidad de Almerí

The Decoupled Potential Integral Equation for Time-Harmonic Electromagnetic Scattering

We present a new formulation for the problem of electromagnetic scattering from perfect electric conductors. While our representation for the electric and magnetic fields is based on the standard vector and scalar potentials ${\bf A},\phi$ in the Lorenz gauge, we establish boundary conditions on the potentials themselves, rather than on the field quantities. This permits the development of a well-conditioned second kind Fredholm integral equation which has no spurious resonances, avoids low frequency breakdown, and is insensitive to the genus of the scatterer. The equations for the vector and scalar potentials are decoupled. That is, the unknown scalar potential defining the scattered field, $\phi^{Sc}$, is determined entirely by the incident scalar potential $\phi^{In}$. Likewise, the unknown vector potential defining the scattered field, ${\bf A}^{Sc}$, is determined entirely by the incident vector potential ${\bf A}^{In}$. This decoupled formulation is valid not only in the static limit but for arbitrary $\omega\ge 0$.Comment: 33 pages, 7 figure

Decoupled field integral equations for electromagnetic scattering from homogeneous penetrable obstacles

[EN] We present a new method for the analysis of electromagnetic scattering from homogeneous penetrable bodies. Our approach is based on a reformulation of the governing Maxwell equations in terms of two uncoupled vector Helmholtz systems: one for the electric field and one for the magnetic field. This permits the derivation of resonance-free Fredholm equations of the second kind that are stable at all frequencies, insensitive to the genus of the scatterers, and invertible for all passive materials including those with negative permittivities or permeabilities. We refer to these as decoupled field integral equations.Vico Bondía, F.; Greengard, L.; Ferrando Bataller, M. (2018). Decoupled field integral equations for electromagnetic scattering from homogeneous penetrable obstacles. Communications in Partial Differential Equations. 43(2):159-184. https://doi.org/10.1080/03605302.2018.1446447S15918443

l-Amino Acid Production by a Immobilized Double-Racemase Hydantoinase Process: Improvement and Comparison with a Free Protein System

Protein immobilization is proving to be an environmentally friendly strategy for manufacturing biochemicals at high yields and low production costs. This work describes the optimization of the so-called “double-racemase hydantoinase process,” a system of four enzymes used to produce optically pure l-amino acids from a racemic mixture of hydantoins. The four proteins were immobilized separately, and, based on their specific activity, the optimal whole relation was determined. The first enzyme, d,l-hydantoinase, preferably hydrolyzes d-hydantoins from d,l-hydantoins to N-carbamoyl-d-amino acids. The remaining l-hydantoins are racemized by the second enzyme, hydantoin racemase, and continue supplying substrate d-hydantoins to the first enzyme. N-carbamoyl-d-amino acid is racemized in turn to N-carbamoyl-l-amino acid by the third enzyme, carbamoyl racemase. Finally, the N-carbamoyl-l-amino acid is transformed to l-amino acid by the fourth enzyme, l-carbamoylase. Therefore, the product of one enzyme is the substrate of another. Perfect coordination of the four activities is necessary to avoid the accumulation of reaction intermediates and to achieve an adequate rate for commercial purposes. The system has shown a broad pH optimum of 7–9, with a maximum activity at 8 and an optimal temperature of 60 °C. Comparison of the immobilized system with the free protein system showed that the reaction velocity increased for the production of norvaline, norleucine, ABA, and homophenylalanine, while it decreased for l-valine and remained unchanged for l-methionine

Eficiencia Energética de los Frigoríficos

En este trabajo de la asignatura de Eficiencia Energética en el Producto 2013-2014 se trata la refrigeración doméstica. En este documento se han plasmado todos los temas que son de interés general a la hora de tener que elegir un frigorífico en el mercado, centrándonos sobre todo en la eficiencia del mismo. También se han obtenidos datos reales de su consumo, y junto con la información recogida se ha creado un diseño de “frigorífico ideal