Mineralizaciones estannovolframíferas en Noia y Lousame, estudio previo.

[Resumen] La región estudiada es rica en mineralizaciones de Sn-W, que son agrupadas por su paragénesis y otras características. Se indica el granito sincinemático como posible causante de mineralizaciones (especialmente, San Finx), y al granito tardicinemático (mina Esperanza). La zona per manece en un bajo nivel de investigación[Abstract] The studied region is rich in Sn-W mineralizations, which are grouped by its mineral paragenesis and other caracteristics. Sincinematic granite is suggested as possible causer of the local mineralization (specially San Finx) anf tardicinematic granite ("Esperanza" mine). This region is in_a low research level actuall

Anomalous quartic WWγγWW\gamma\gamma couplings in epep collisions at the LHeC and the FCC-he

We conducted a study on measuring $W^+W^-$ production and on the sensitivity limits at $95\%$ Confidence Level on thirteen anomalous couplings obtained by dimension-8 operators which are related to the anomalous quartic $WW\gamma\gamma$ couplings. We consider the main $e^-p \to e^-\gamma^*\gamma^*p \to e^-W^+W^-p$ reaction with the sub-process $\gamma^*\gamma^* \to W^+W^-$ at the Large Hadron electron Collider (LHeC) and the Future Circular Collider-hadron electron (FCC-he). For the LHeC, energies of the $e^-$ beams are taken to be $E_e =60$ and 140 GeV and the energy of the $p$ beams is taken to be $E_p = 7$ TeV. For the FCC-he, energies of the $e^-$ beams are taken to be $E_e =60$ and 140 GeV and the energy of the $p$ beams is taken to be $E_p = 50$ TeV, respectively. It is interesting to notice that the LHeC and the FCC-he will lead to model-independent limits on the anomalous quartic $WW\gamma\gamma$ couplings which are one order of magnitude stringent than the CMS Collaboration limits, in addition to being competitive with other limits reported in the literature.Comment: 28 pages, 10 Figures and 13 Table

Geometric constraint subsets and subgraphs in the analysis of assemblies and mechanisms

Geometric Reasoning ability is central to many applications in CAD/CAM/CAPP environments -- An increasing demand exists for Geometric Reasoning systems which evaluate the feasibility of virtual scenes specified by geometric relations -- Thus, the Geometric Constraint Satisfaction or Scene Feasibility (GCS/SF) problem consists of a basic scenario containing geometric entities, whose context is used to propose constraining relations among still undefined entities -- If the constraint specification is consistent, the answer of the problem is one of finitely or infinitely many solution scenarios satisfying the prescribed constraints -- Otherwise, a diagnostic of inconsistency is expected -- The three main approaches used for this problem are numerical, procedural or operational and mathematical -- Numerical and procedural approaches answer only part of the problem, and are not complete in the sense that a failure to provide an answer does not preclude the existence of one -- The mathematical approach previously presented by the authors describes the problem using a set of polynomial equations -- The common roots to this set of polynomials characterizes the solution space for such a problem -- That work presents the use of Groebner basis techniques for verifying the consistency of the constraints -- It also integrates subgroups of the Special Euclidean Group of Displacements SE(3) in the problem formulation to exploit the structure implied by geometric relations -- Although theoretically sound, these techniques require large amounts of computing resources -- This work proposes Divide-and-Conquer techniques applied to local GCS/SF subproblems to identify strongly constrained clusters of geometric entities -- The identification and preprocessing of these clusters generally reduces the effort required in solving the overall problem -- Cluster identification can be related to identifying short cycles in the Spatial Con straint graph for the GCS/SF problem -- Their preprocessing uses the aforementioned Algebraic Geometry and Group theoretical techniques on the local GCS/SF problems that correspond to these cycles -- Besides improving theefficiency of the solution approach, the Divide-and-Conquer techniques capture the physical essence of the problem -- This is illustrated by applying the discussed techniques to the analysis of the degrees of freedom of mechanism

Antiguas explotaciones de estaño-wolframio en Arteixo y Laracha (resumen)

[Resumen] En los términos municipales de Arteixo y Laracha se conocen una serie de pequeñas explotaciones sobre yacimientos de wolframita-casiterita, de escaso interés tomándolos por separados, pero con importancia potencial en su conjunto. Todos estos yacimientos fueron trabajados de forma muy rudimentaria entre los años 1940 a 1968, fecha en que cerró la última mina de la zona. El único estudio conocido sobre alguno de estos yacimientos corresponde a uno realizado por el Instituto Geológico y Minero, que investigó por medio de prospección geoquímica para Sn-W en la zona de Monteagudo-Lendo, clasificando la zona de Laracha como de interés medio a escaso para estas sustancias

EGCL: an extended G-Code Language with flow control, functions and mnemonic variables

In the context of computer numerical control (CNC) and computer aided manufacturing (CAM), the capabilities of programming languages such as symbolic and intuitive programming, program portability and geometrical portfolio have special importance -- They allow to save time and to avoid errors during part programming and permit code re-usage -- Our updated literature review indicates that the current state of art presents voids in parametric programming, program portability and programming flexibility -- In response to this situation, this article presents a compiler implementation for EGCL (Extended G-code Language), a new, enriched CNC programming language which allows the use of descriptive variable names, geometrical functions and flow-control statements (if-then-else, while) -- Our compiler produces low-level generic, elementary ISO-compliant Gcode, thus allowing for flexibility in the choice of the executing CNC machine and in portability -- Our results show that readable variable names and flow control statements allow a simplified and intuitive part programming and permit re-usage of the programs -- Future work includes allowing the programmer to define own functions in terms of EGCL, in contrast to the current status of having them as library built-in function

Limits on the Electromagnetic and Weak Dipole Moments of the Tau-Lepton in E_6 Superstring Models

We obtain limits on the electromagnetic and weak dipole moments of the tau-lepton in the framework of a Left-Right symmetric model (LRSM) and a class of $E_6$ inspired models with an additional neutral vector boson $Z_\theta$. Using as an input the data obtained by the L3 and OPAL Collaborations for the reaction $e^+e^-\to \tau^+\tau^-\gamma$, we get a stringent limit on the LRSM mixing angle $\phi$, $-1.66\times 10^{-3}< \phi<1.22\times 10^{-3}$, which in turn induces bounds on the tau weak dipole moments which are consistent with the bounds obtained recently by the DELPHI and ALEPH Collaborations from the reaction $e^+e^-\to \tau^+\tau^-$. We also get similar bounds for the weak dipole moments of the tau lepton in the framework of $E_6$ superstring models.Comment: 18 pages, 5 figure

Fixed grid finite element analysis for 3D structural problems

Fixed Grid (FG) methodology was first introduced by García and Steven as an engine for numerical estimation of two-dimensional elasticity problems -- The advantages of using FG are simplicity and speed at a permissible level of accuracy -- Two dimensional FG has been proved effective in approximating the strain and stress field with low requirements of time and computational resources -- Moreover, FG has been used as the analytical kernel for different structural optimisation methods as Evolutionary Structural Optimisation, Genetic Algorithms (GA), and Evolutionary Strategies -- FG consists of dividing the bounding box of the topology of an object into a set of equally sized cubic elements -- Elements are assessed to be inside (I), outside (O) or neither inside nor outside (NIO) of the object -- Different material properties assigned to the inside and outside medium transform the problem into a multi-material elasticity problem -- As a result of the subdivision NIO elements have non-continuous properties -- They can be approximated in different ways which range from simple setting of NIO elements as O to complex noncontinuous domain integration -- If homogeneously averaged material properties are used to approximate the NIO element, the element stiffness matrix can be computed as a factor of a standard stiffness matrix thus reducing the computational cost of creating the global stiffness matrix. An additional advantage of FG is found when accomplishing re-analysis, since there is no need to recompute the whole stiffness matrix when the geometry changes -- This article presents CAD to FG conversion and the stiffness matrix computation based on non-continuous elements -- In addition inclusion/exclusion of O elements in the global stiffness matrix is studied -- Preliminary results shown that non-continuous NIO elements improve the accuracy of the results with considerable savings in time -- Numerical examples are presented to illustrate the possibilities of the metho

On the critical point structure of eigenfunctions belonging to the first nonzero eigenvalue of a genus two closed hyperbolic surface

We develop a method based on spectral graph theory to approximate the eigenvalues and eigenfunctions of the Laplace-Beltrami operator of a compact riemannian manifold -- The method is applied to a closed hyperbolic surface of genus two -- The results obtained agree with the ones obtained by other authors by different methods, and they serve as experimental evidence supporting the conjectured fact that the generic eigenfunctions belonging to the first nonzero eigenvalue of a closed hyperbolic surface of arbitrary genus are Morse functions having the least possible total number of critical points among all Morse functions admitted by such manifold

Gestión eficiente de reconocimiento del iris en bases de datos objetos-relacionales

Biometric applications have grown significantly in recent years, particularly iris-based systems. In the present work, an extension of an Object Relational Database Management System for the integral management of a biometric system based on the human iris was presented. Although at present, there are many database extensions for different domains, in no case for biometric applications. The proposed extension includes both the extension of the type system and the definition of domain indexes for performance improvement. The aim of this work is to provide a tool that facilitates the development of biometric applications based on the iris feature. Its development is based on a reference architecture that includes both the management of images of the iris trait, its associated metadata and the necessary methods for both manipulation and queries. An implementation of the extension is performed for PostgreSQL DBMS, and SP-GiST framework is used in the implementation of a domain index. Experiments were carried out to evaluate the performance of the proposed index, which shows improvements in query execution times.Las aplicaciones biométricas han crecido significativamente en los últimos años, en particular los sistemas basados en el iris. En el presente trabajo se presenta una ampliación de un Sistema de Gestión de Base de Datos Objeto-Relacional para la gestión integral de un sistema biométrico basado en el iris humano. Aunque en la actualidad existen muchas extensiones de bases de datos para diferentes dominios, en ningún caso existen para aplicaciones biométricas. La extensión propuesta incluye tanto la extensión del sistema de tipos como la definición de índices de dominio para la mejora del rendimiento. El objetivo de este trabajo es proporcionar una herramienta que facilite el desarrollo de aplicaciones biométricas basadas en el iris. Su desarrollo se basa en una arquitectura de referencia que incluye tanto la gestión de las imágenes del rasgo del iris, sus metadatos asociados y los métodos necesarios, tanto para la manipulación como para las consultas. Se realiza una implementación de la extensión para PostgreSQL DBMS, y se utiliza el framework SPGiST en la implementación de un índice de dominio. Se realizaron experimentos para evaluar el desempeño del índice propuesto, que muestra mejoras en los tiempos de ejecución de las consultas.Facultad de Informátic

Gestión eficiente de reconocimiento del iris en bases de datos objetos-relacionales

Biometric applications have grown significantly in recent years, particularly iris-based systems. In the present work, an extension of an Object Relational Database Management System for the integral management of a biometric system based on the human iris was presented. Although at present, there are many database extensions for different domains, in no case for biometric applications. The proposed extension includes both the extension of the type system and the definition of domain indexes for performance improvement. The aim of this work is to provide a tool that facilitates the development of biometric applications based on the iris feature. Its development is based on a reference architecture that includes both the management of images of the iris trait, its associated metadata and the necessary methods for both manipulation and queries. An implementation of the extension is performed for PostgreSQL DBMS, and SP-GiST framework is used in the implementation of a domain index. Experiments were carried out to evaluate the performance of the proposed index, which shows improvements in query execution times.Las aplicaciones biométricas han crecido significativamente en los últimos años, en particular los sistemas basados en el iris. En el presente trabajo se presenta una ampliación de un Sistema de Gestión de Base de Datos Objeto-Relacional para la gestión integral de un sistema biométrico basado en el iris humano. Aunque en la actualidad existen muchas extensiones de bases de datos para diferentes dominios, en ningún caso existen para aplicaciones biométricas. La extensión propuesta incluye tanto la extensión del sistema de tipos como la definición de índices de dominio para la mejora del rendimiento. El objetivo de este trabajo es proporcionar una herramienta que facilite el desarrollo de aplicaciones biométricas basadas en el iris. Su desarrollo se basa en una arquitectura de referencia que incluye tanto la gestión de las imágenes del rasgo del iris, sus metadatos asociados y los métodos necesarios, tanto para la manipulación como para las consultas. Se realiza una implementación de la extensión para PostgreSQL DBMS, y se utiliza el framework SPGiST en la implementación de un índice de dominio. Se realizaron experimentos para evaluar el desempeño del índice propuesto, que muestra mejoras en los tiempos de ejecución de las consultas.Facultad de Informátic