58 research outputs found
Asistencia técnica para el fortalecimiento de pequeñas unidades productivas para la habilitación de lugares de elaboración de alimentos y comercialización de los productos en ferias municipales
El proyecto tiene como objetivo que los pequeños productores de alimentos puedan habilitar un lugar de elaboración para sus productos, reciban asesoramiento técnico y el control necesario para asegurar la inocuidad de los alimentos. Además, que los productos elaborados tengan un lugar de comercialización controlado y común a los emprendedores que se encuentren dentro de esta metodología de trabajo. Esto lo lograremos trabajando en la generación de dos ordenanzas comunes a los municipios que integren el grupo de trabajo. La primera tiene como objetivo fijar las condiciones mínimas para habilitar, desde la municipalidad, los sectores de elaboración de estos pequeños productores, y la otra ordenanza tendrá como finalidad la creación de una feria en cada municipio donde puedan comercializar sus productos no sólo en el municipio al que pertenecen sino también en los municipios que adhieran al proyecto.Eje: Territorio y estrategias de intervenciónUniversidad Nacional de La Plat
Adiabatic transfer of light in a double cavity and the optical Landau-Zener problem
We analyze the evolution of an electromagnetic field inside a double cavity
when the difference in length between the two cavities is changed, e.g. by
translating the common mirror. We find that this allows photons to be moved
deterministically from one cavity to the other. We are able to obtain the
conditions for adiabatic transfer by first mapping the Maxwell wave equation
for the electric field onto a Schroedinger-like wave equation, and then using
the Landau-Zener result for the transition probability at an avoided crossing.
Our analysis reveals that this mapping only rigorously holds when the two
cavities are weakly coupled (i.e. in the regime of a highly reflective common
mirror), and that, generally speaking, care is required when attempting a
hamiltonian description of cavity electrodynamics with time-dependent boundary
conditions.Comment: 24 pages, 18 figures. Version 2 includes a new section (Sec. VIII) on
the regimes of validity of the Schroedinger-like equations and also of the
adiabatic approximation, together with a new figure (Fig. 10). The discussion
section (Sec. XI) has also been enhance
Functional diversity of bacterial genes associated with aromatic hydrocarbon degradation in anthropogenic dark earth of Amazonia.
The objective of this work was to evaluate the catabolic gene diversity for the bacterial degradation of aromatic hydrocarbons in anthropogenic dark earth of Amazonia (ADE) and their biochar (BC). Functional diversity analyses in ADE soils can provide information on how adaptive microorganisms may influence the fertility of soils and what is their involvement in biogeochemical cycles. For this, clone libraries containing the gene encoding for the alpha subunit of aromatic ring-hydroxylating dioxygenases (a-ARHD bacterial gene) were constructed, totaling 800 clones. These libraries were prepared from samples of an ADE soil under two different land uses, located at the Caldeirão Experimental Station - secondary forest (SF) and agriculture (AG) -, and the biochar (SF_BC and AG_BC, respectively). Heterogeneity estimates indicated greater diversity in BC libraries; and Venn diagrams showed more unique operational protein clusters (OPC) in the SF_BC library than the ADE soil, which indicates that specific metabolic processes may occur in biochar. Phylogenetic analysis showed unidentified dioxygenases in ADE soils. Libraries containing functional gene encoding for the alpha subunit of the aromatic ring-hydroxylating dioxygenases (ARHD) gene from biochar show higher diversity indices than those of ADE under secondary forest and agriculture
Cavity QED and quantum information processing with "hot" trapped atoms
We propose a method to implement cavity QED and quantum information
processing in high-Q cavities with a single trapped but non-localized atom. The
system is beyond the Lamb-Dick limit due to the atomic thermal motion. Our
method is based on adiabatic passages, which make the relevant dynamics
insensitive to the randomness of the atom position with an appropriate
interaction configuration. The validity of this method is demonstrated from
both approximate analytical calculations and exact numerical simulations. We
also discuss various applications of this method based on the current
experimental technology.Comment: 14 pages, 8 figures, Revte
Medición de impactos en una terraza verde para la definición de estandares de eficiencia en sistemas de techos verdes intensivos y extensivos en condiciones urbanas. Caso de estudio: Ciudad de Córdoba
Una alternativa para moderar el equilibrio en los ecosistemas urbanos e integrar la vegetación a las ciudades, lo constituyen los techos verdes. Dichos sistemas aportan servicios ecosistemicos, como la mitigación de las variaciones de temperatura entre el exterior y el interior de las unidades habitacionales, contribuyendo a la eficiencia energética de las construcciones edilicias. En el presente proyecto de investigación se evalúa la adecuación de esta tecnología a condiciones constructivas reales; como así también el impacto de los dos tipos de sistemas: el extensivo y el intensivo, comparándolos con un techo blanco como testigo. En dos aulas taller contiguas de la facultad de arquitectura se instaló un sistema extensivo de techos verdes (80 m2) y la otra se pintó la loza de blanco (testigo). En el techo del aula testigo se instalaron 3 cubos de simulación de 1 m3 para simular ambos sistemas (extensivo e intensivo) y comparar con el testigo. Se colocaron sensores exteriores, de loza e interiores tanto en ambas aulas como en los cubos, para evaluar la eficiencia energética y en los cubos además, la escorrentía. Se están procesando y analizando los datos recibidos para estimar las propiedades térmicas, las diferencias de temperaturas en los diferentes espacios, así como el impacto energéticode ambos sistemas. Al mismo tiempo se está analizando la detección y detención de la escorrentía de las lluvias recibidas en ese período. Este proyecto permite medir el impacto positivo del techo verde, establecer comparaciones entre sistemas constructivos, y dimensionar la magnitud de algunos de los servicos ecosistémicos que este mismo presta (e.g. regulación térmica, colecta del agua de lluvia, retención y detención de escorrentía, entre otros). La estimación certera de estos beneficios potenciales permitirá la definición de estándares de eficiencia
Expedition 376 summary
Volcanic arcs are the surface expression of magmatic systems that result from subduction of mostly oceanic lithosphere at convergent plate boundaries. Arcs with a submarine component include intraoceanic arcs and island arcs that span almost 22,000 km on Earth’s surface, and the vast majority of them are located in the Pacific region. Hydrothermal systems hosted by submarine arc volcanoes commonly contain a large component of magmatic fluid. This magmatic-hydrothermal signature, coupled with the shallow water depths of arc volcanoes and their high volatile contents, strongly influences the chemistry of the fluids and resulting mineralization and likely has important consequences for the biota associated with these systems. The high metal content and very acidic fluids in these hydrothermal systems are thought to be important analogs to numerous porphyry copper and epithermal gold deposits mined today on land.
During International Ocean Discovery Program (IODP) Expedition 376 (5 May–5 July 2018), a series of five sites was drilled on Brothers volcano in the Kermadec arc. The expedition was designed to provide the missing link (i.e., the third dimension) in our understanding of hydrothermal activity and mineral deposit formation at submarine arc volcanoes and the relationship between the discharge of magmatic fluids and the deep biosphere. Brothers volcano hosts two active and distinct hydrothermal systems: one is seawater influenced and the other is affected by magmatic fluids (largely gases). In total, 222.4 m of volcaniclastics and lavas were recovered from the five sites drilled, which include Sites U1527 and U1530 in the Northwest (NW) Caldera seawater-influenced hydrothermal field; Sites U1528 and U1531 in the magmatic fluid-influenced hydrothermal fields of the Upper and Lower Cones, respectively; and Site U1529, located within an area of low crustal magnetization that marks the West (W) Caldera upflow zone on the caldera floor. Downhole logging and borehole fluid sampling were completed at two sites, and two tests of a prototype turbine-driven coring system (designed by the Center for Deep Earth Exploration [CDEX] at Japan Agency for Marine-Earth Science and Technology [JAMSTEC]) for drilling and coring hard rocks were conducted.
Core recovered from all five sites consists of dacitic volcaniclastics and lava flows with only limited chemical variability relative to the overall range in composition of dacites in the Kermadec arc. Pervasive alteration with complex and variable mineral assemblages attest to a highly dynamic hydrothermal system. The upper parts of several drill holes at the NW Caldera hydrothermal field are characterized by secondary mineral assemblages of goethite + opal + zeolites that result from low-temperature (<150°C) reaction of rock with seawater. At depth, NW Caldera Site U1527 exhibits a higher temperature (~250°C) secondary mineral assemblage dominated by chlorite + quartz + illite + pyrite. An older mineral assemblage dominated by diaspore + quartz + pyrophyllite + rutile at the bottom of Hole U1530A is indicative of acidic fluids with temperatures of ~230°–320°C. In contrast, the alteration assemblage at Site U1528 on the Upper Cone is dominated by illite + natroalunite + pyrophyllite + quartz + opal + pyrite, which attests to high-temperature reaction of rocks with acid-sulfate fluids derived from degassed magmatic volatiles and the disproportionation of magmatic SO2. These intensely altered rocks exhibit extreme depletion of major cation oxides, such as MgO, K2O, CaO, MnO, and Na2O. Furthermore, very acidic (as low as pH 1.8), relatively hot (≤236°C) fluids collected at 160, 279, and 313 meters below seafloor in Hole U1528D have chemical compositions indicative of magmatic gas input. In addition, preliminary fluid inclusion data provide evidence for involvement of two distinct fluids: phase-separated (modified) seawater and a ~360°C hypersaline brine, which alters the volcanic rock and potentially transports metals in the system.
The material and data recovered during Expedition 376 provide new stratigraphic, lithologic, and geochemical constraints on the development and evolution of Brothers volcano and its hydrothermal systems. Insights into the consequences of the different types of fluid–rock reactions for the microbiological ecosystem elucidated by drilling at Brothers volcano await shore-based studies
Multidisciplinary scientific cruise to the Rio Grande Rise
The full text of this article can be freely accessed on the publisher's website
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