Coal/rock interface detection by sensitized pick, part A

In order to increase the operating margins of the detector for safe, reliable operation under difficult in-mine conditions the transmitted signal strength was increased to provide additional signal margin for in-mine conditions and the transmitter section was redesigned to reduce frequency pulling of the transmitter frequency with variations in antenna load. The linearity of the pick load SCO signal with true pick load was increased, and hysteresis effects were minimized. The sensitized pick hardware was ruggedized for rough inmine use. The sensitized pick and telemetry system provided excellent, high quality signals proportional to cutting load under all conditions experienced during testing

Advanced digital SAR processing study

A highly programmable, land based, real time synthetic aperture radar (SAR) processor requiring a processed pixel rate of 2.75 MHz or more in a four look system was designed. Variations in range and azimuth compression, number of looks, range swath, range migration and SR mode were specified. Alternative range and azimuth processing algorithms were examined in conjunction with projected integrated circuit, digital architecture, and software technologies. The advaced digital SAR processor (ADSP) employs an FFT convolver algorithm for both range and azimuth processing in a parallel architecture configuration. Algorithm performace comparisons, design system design, implementation tradeoffs and the results of a supporting survey of integrated circuit and digital architecture technologies are reported. Cost tradeoffs and projections with alternate implementation plans are presented

The smallest space miners: principles of space biomining

As we aim to expand human presence in space, we need to find viable approaches to achieve independence from terrestrial resources. Space biomining of the Moon, Mars and asteroids has been indicated as one of the promising approaches to achieve in-situ resource utilization by the main space agencies. Structural and expensive metals, essential mineral nutrients, water, oxygen and volatiles could be potentially extracted from extraterrestrial regolith and rocks using microbial-based biotechnologies. The use of bioleaching microorganisms could also be applied to space bioremediation, recycling of waste and to reinforce regenerative life support systems. However, the science around space biomining is still young. Relevant differences between terrestrial and extraterrestrial conditions exist, including the rock types and ores available for mining, and a direct application of established terrestrial biomining techniques may not be a possibility. It is, therefore, necessary to invest in terrestrial and space-based research of specific methods for space applications to learn the effects of space conditions on biomining and bioremediation, expand our knowledge on organotrophic and community-based bioleaching mechanisms, as well as on anaerobic biomining, and investigate the use of synthetic biology to overcome limitations posed by the space environments

Computer Science and Game Theory: A Brief Survey

There has been a remarkable increase in work at the interface of computer science and game theory in the past decade. In this article I survey some of the main themes of work in the area, with a focus on the work in computer science. Given the length constraints, I make no attempt at being comprehensive, especially since other surveys are also available, and a comprehensive survey book will appear shortly.Comment: To appear; Palgrave Dictionary of Economic

Impacto de la deposición de ceniza volcánica sobre la productividad foliar y la herbivoría por insectos en bosques deciduos del norte de la Patagonia

Volcanism has been a major force shaping the dynamics of Andean landscapes during the Holocene. Yet we still know little about the consequences of modern volcanic events on forest functioning. Ash fall may elicit multiple direct and indirect effects on key ecosystem attributes, with disturbance severity likely varying with distance to the crater. We examined the impact of ash deposition on foliage productivity and insect herbivory after the 2011 eruption of the Volcán Puyehue-Cordón Caulle system, in Nothofagus pumilio forests of northern Patagonia, Argentina. Tree leaf litterfall, a surrogate for annual foliar production, was measured before and after the event in wet and dry forest sites, which were located 22 km and 80 km east from the crater and were affected by mass deposition of coarse- and fine-grained tephra, respectively. Leaf damage by insects was monitored over a 10-year span (2004-2013) including the volcanic event. Foliar productivity in 2012 dropped by 60% in the wet forest, but did not change in the dry forest. Leaf area damaged by insects decreased abruptly in 2012, with post-eruption herbivory levels falling outside the range of annual variation recorded before the event. The impact was most severe in the dry forest wich normally supports the highest endemic herbivory. In contrast, leaf damage remained high in another dry forest located 98 km southeast from the crater and little affected by ashfall. Changes in foliar production and insect herbivory persisted for two years after the event. Our results show a widespread disruption of canopy-herbivore interactions in areas heavily affected by tephra. Remarkably, volcanic ash acted as a broad-spectrum insecticide on canopy herbivores. In the short-term, ashfall constrained the energy flow through the forest canopy and the arthropod consumer community, and thus temporarily overwhelmed previously existing differences in productivity and herbivory between wet and dry forest habitats.Impacto de la deposición de ceniza volcánica sobre la productividad foliar y la herbivoría por insectos en bosques deciduos del norte de la Patagonia: El vulcanismo ha moldeado la dinámica de los paisajes andinos durante todo el Holoceno. Sin embargo, aún se conoce poco sobre las consecuencias de eventos volcánicos modernos en el funcionamiento de los bosques nativos. La caída masiva de cenizas puede generar múltiples efectos directos e indirectos sobre procesos clave del ecosistema. Aquí evaluamos el impacto de la deposición de cenizas emitidas por la erupción del complejo Volcán Puyehue-Cordón Caulle en junio de 2011, sobre la productividad foliar y la herbivoría por insectos del dosel en bosques de Nothofagus pumilio del norte de la Patagonia Argentina. La producción de hojas fue medida antes y después de la erupción, en bosques húmedos y secos situados a 22 y 80 km del volcán y afectados por la caída de pumicita gruesa y fina, respectivamente. El área foliar dañada por insectos fue monitoreada durante 10 años (2004-2013), incluyendo al evento volcánico. La productividad foliar en 2012 cayó un 60% en el bosque húmedo pero no cambió en el bosque seco. El daño foliar se redujo abruptamente en 2012; los niveles de herbivoría post-erupción cayeron por debajo del rango de variación interanual registrado antes de la erupción. El impacto fue más severo en el bosque seco, donde los niveles endémicos de herbivoría son más elevados. En cambio, la herbivoría se mantuvo elevada en otro bosque seco localizado a 98 km del cráter y que recibió pocas cenizas. Los cambios en productividad y herbivoría persistieron por dos años después del evento. Estos resultados muestran una fuerte disrupción de las interacciones planta-herbívoro en áreas boscosas afectadas por la erupción volcánica. Las cenizas actuaron como un biocida de amplio espectro sobre los insectos defoliadores. En el corto plazo, la deposición de cenizas limitó el flujo de energía a través del dosel arbóreo y hacia los consumidores artrópodos.Fil: Chaneton, Enrique Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas A la Agricultura; ArgentinaFil: Mazía, Noemí. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal; ArgentinaFil: Garibaldi, Lucas Alejandro. Universidad Nacional de Rio Negro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chaij, Jaquelina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal; ArgentinaFil: Kitzberger, Thomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentin