Unraveling the Effects of Melt–Mantle Interactions on the Gold Fertility of Magmas

We thank Tony Lanzirotti and Matt Newville for assistance with μ-XANES analyses at the GeoSoilEnviroCars (Sector 13), Advanced Photon Source (APS), Argonne National Laboratory.The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/feart.2020.00029/full#supplementary-materialThe oxidation state of the Earth’s mantle and its partial melting products exert a key control on the behavior and distribution of sulfur and chalcophile and siderophile elements between the mantle and crust, underpinning models of ore deposit formation. Whether the oxidized nature of magmas is inherited from the asthenospheric mantle source or acquired during ascent and differentiation is vigorously debated, limiting our understanding of the mechanisms of extraction of sulfur and metals from the mantle. Here, we focused on the redox-sensitive behavior of sulfur in apatite crystallized from quenched alkaline basaltic melts preserved within a peridotite xenolith from the El Deseado Massif auriferous province in southern Patagonia. We took advantage of this unique setting to elucidate the redox evolution of melts during their ascent through the subcontinental lithospheric mantle (SCLM) and grasp the inner workings of the Earth’s mantle during gold metallogenesis. Our data reveal that an initially reduced silicate melt (ΔFMQ −2.2 to −1.2) was oxidized to ΔFMQ between 0 and 1.2 during percolation and interaction with the surrounding peridotite wall-rock (ΔFMQ 0 to +0.8). This process triggered changes in sulfur speciation and solubility in the silicate melt, boosting the potential of the melt to scavenge ore metals such as gold. We suggest that large redox gradients resulting from the interaction between ascending melts and the surrounding mantle can potentially modify the oxidation state of primitive melts and enhance their metallogenic fertility. Among other factors including an enriched metal source and favorable geodynamic conditions, redox gradients in the mantle may exert a first-order control on the global-scale localization of crustal provinces endowed with gold deposits.This study was funded by the Iniciativa Científica Milenio through Millennium Nucleus for Metal Tracing along Subduction Grant NC130065. Additional funding for analytical work was provided by the FONDAP project 15090013 “Centro de Excelencia en Geotermia de Los Andes, CEGA.” ST acknowledges CONICYT for support through a Ph.D. scholarship #21170857. Grants RTI2018-099157-A-100 and RYC-2015-1796 provided funding for sample preparation and EPMA analyses. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. The DID-UACh project #S-201505 financed the fieldwork

FORMACIÓN DE PARTÍCULAS POR PLASMA DERIVADAS DE PIRROL

Este trabajo consistió en la síntesis de partículas derivadas de pirrol mediante plasmas de descargas luminiscentes. La caracterización de las partículas se realizó por Espectroscopíade Infrarrojo (IR), MicroscopíaElectrónica de Barrido (MEB), MicroscopíaElectrónica de Transmisión (MET), EspectroscopíaFotoelectrónica de Rayos X (XPS) y conductividad el̩ctric

XFVHDL4: A hardware synthesis tool for fuzzy systems

This paper presents a design technique that allows the automatic synthesis of fuzzy inference systems and accelerates the exploration of the design space of these systems. It is based on generic VHDL code generation which can be implemented on a programmable device (FPGA) or an application specific integrated circuit (ASIC). The set of CAD tools supporting this technique includes a specific environment for designing fuzzy systems, in combination with commercial VHDL simulation and synthesis tools. As demonstrated by the analyzed design examples, the described development strategy speeds up the stages of description, synthesis, and functional verification of fuzzy inference systems.Comunidad Europea FP7-IST-248858Ministerio de Ciencia e Innovación TEC2008-04920Junta de Andalucía P08-TIC-0367

Controlador difuso para problemas de navegación en presencia de obstáculos fijos

En esta comunicación se describe un sistema de control difuso para aplicaciones de navegación de robots móviles autónomos en presencia de obstáculos fijos. Las herramientas de CAD del entorno Xfuzzy 3, desarrollado en el IMSE, han facilitado el diseño del controlador. En la comunicación se procede a la verificación del controlador diseñado operando en un lazo cerrado con el modelo del robot móvil autónomo eléctrico Romeo 4R, diseñado y construido en la Escuela Superior de Ingenieros de la Universidad de Sevilla. Las simulaciones realizadas demuestran la eficiencia del controlador desarrollado.Comisión Interministerial de Ciencia y Tecnología TEC2005-04359/MICJunta de Andalucía DPI2005-0229

An automated design flow from linguistic models to piecewise polynomial digital circuits

This paper describes how the different CAD tools of the environment Xfuzzy 3, developed in Microelectronics Institute of Seville and University of Seville, allow to translate expressive linguistic models into mathematical ones, in particular, into a combination of piecewise polynomial systems that can be implemented efficiently in hardware. The new synthesis tool of Xfuzzy 3 automates communication with Xilinx System Generator in Matlab, thus facilitating implementation of the linguistic model into an FPGA from Xilinx. This is illustrated with the design of a navigation controller for an autonomous robot.Comunidad Europea FP7-IST-248858Ministerio de Ciencia y Tecnología TEC2008-04920Junta de Andalucía P08-TIC-0367

Soft computing techniques for video de-interlacing

This paper presents the application of soft computing techniques to video processing. Specially, the research work has been focused on de-interlacing task. It is necessary whenever the transmission standard uses an interlaced format but the receiver requires a progressive scanning, as happens in consumer displays such as LCDs and plasma. A simple hierarchical solution that combines three simple fuzzy logicbased constituents (interpolators) is presented in this paper. Each interpolator specialized in one of three key image features for de-interlacing: motion, edges, and possible repetition of picture areas. The resulting algorithm offers better results than others with less or similar computational cost. A very interesting result is that our algorithm is competitive with motion-compensated algorithm

FPGA-based implementation of a fuzzy motion adaptive de-interlacing algorithm

This paper surveys the hardware implementation of a de-interlacing algorithm on Field-Programmable Technology for real-time processing. The algorithm presented evaluates the level of motion at each pixel, and determines the interpolation between a spatial and a temporal method according to the presence of motion. To achieve it the algorithm employs an hierarchical structure with three simple fuzzy systems. The first one performs a set of fuzzy rules to apply reasoning in order to detect motion; the second one selects the most convenient direction to implement an edge-dependent line average method; and the third one is used to choose the most adequate temporal method. The hardware implementation of this algorithm combines pipeline architecture with a parallel processing of fuzzy rules to accelerate the computation. As result an efficient implementation is developed in terms of computational time and hardware cos

Aplicación de técnicas de interpolación basadas en lógica difusa al procesado de imágenes de video

Muchas tareas básicas de procesado de imágenes requieren la manipulación de grandes volúmenes de información que, en ocasiones, puede resultar ambigua y/o imprecisa como consecuencia de las características propias de las imágenes (gran cantidad de detalles con grandes contrastes de valores de luminancia y secuencias con un elevado grado de movimiento) o de los defectos de las mismas (presencia de ruido, falta de nitidez, etc.). En esta comunicación se analizan nuevas técnicas de interpolación basadas en lógica difusa que proporcionan soluciones eficaces para dos aplicaciones típicas de procesado de imágenes: el desentrelazado de señales de vídeo y el incremento de resolución de imágenes

Tuning of a hierarchical fuzzy system for video de-interlacing

The tuning of hierarchical fuzzy systems are not supported by the majority of CAD tools available at the market currently. The xfsl tool integrated into Xfuzzy 3 allows the tuning of complex fuzzy systems, for instance, hierarchical systems with modules in cascade. The authors propose the use of this tool for tuning a complex fuzzy system for video deinterlacing in this paper. The parameters obtained after tuning are proven by de-interlacing a wide battery of sequences. The use of tuning techniques improves the quality of de-interlacing and provides an algorithm simplification that facilitates its hardware implementatio

A motion and edge adaptive interlaced-to-progressive conversion using fuzzy logic-based systems

This paper presents an algorithm for video de-interlacing. The approach uses three fuzzy logic-based systems to adapt the interpolation strategy to the presence of motion and edges. Furthermore, the algorithm is able to deal with any kind of TV material independently of the source used to acquire the scene. Extensive simulations of standard and real sequences prove the efficiency of the proposed algorithmMinisterio de Educación y Ciencia TEC2005-04359 y DPI2005-02293Junta de Andalucía TIC2006-635 y TEP2006-37