Internal water channel loss : Mendoza (Argentina)

Mendoza (Argentina) es una zona árida que se abastece de agua de los deshielos en las altas cuencas de los Andes. Su distribución se efectúa por una red semipública de 12 270 km de canales, de los cuales sólo 660 están impermeabilizados. La responsabilidad para mejorar dicha infraestructura -desde el dique hasta bocatoma de finca- recae sobre el Dpto. Gral. de Irrigación en la red primaria y las Inspecciones de Cauces, en la red secundaria y derivados. La distribución dentro de las fincas se realiza por cauces en tierra con pérdidas del 5 al 13 % en función de la textura de los suelos y el contenido de sedimentos de las aguas. Las aguas claras, cuando provengan del dique Potrerillos, incrementarán las pérdidas. Con el objeto de mejorar la eficiencia interna se determinó la relación entre longitud del cauce distribuidor y la superficie cultivada. Posteriormente se calcularon las pérdidas anuales de agua infiltrada por metro lineal. Para paliar estas pérdidas se confeccionaron tablas de uso práctico para revestimientos de pequeños cauces para las secciones rectangular y trapecial y para diferentes caudales, pendientes y materiales. Complementan esta acción la factibilidad de construcción de aforadores que posibiliten la recepción volumétrica, la reducción de jornales para riego y mantenimiento y el menor costo de mantenimiento de la red pública y privada de colectores de drenajes.The water distribution is done by means of an important semipublic net of ditches wich are 12 270 km. long. Only 660 of them are lined. Two sectors are responsible for carrying out the improvements in the understructures of the distribution net from the damn to the farm inlet gate. The official sector which is represented by the Gral. Dept. of Irrigation in the main net, and the Water Users Association in the secondary and derived nets. Both sectors are nowadays construccion and modernizing the irrigation nets. Land channel do the internal distribution of the water, the distance between the inlet gate and the head of the irrigation units. There are conveyance losses that can vary from the 5 % to the 13 % according to the land texture and the quality of the water. The aim of this work is to improve the internal efficiency. For this purpose the relation between the length of the distribution ditch and the cultivated area was determined. After that the annual losses of intake water by each lineal meter were calculated. In order to avoid the water losses practical dimension tables were made for different kinds of flow rates, slopes and materials. The complementary justification for this is: the feasability of the construction of flume that permit the volume reception, reduction of wages for irrigation time and a saving in the cost of maintenance of the public and private net of the collecting drains.Fil: Ortiz Maldonado, Gonzalo. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Tapia, Carlos F.. Universidad Nacional de Cuyo. Facultad de IngenieríaFil: Cerutti, Gustavo. Mendoza. Departamento General de Irrigació

Culture: Not just Burns – what about the poet Robert Fergusson?

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Star formation across the w3 complex

We present a multi-wavelength analysis of the history of star formation in the W3 complex. Using deep, near-infrared ground-based images combined with images obtained with Spitzer and Chandra observatories, we identified and classified young embedded sources. We identified the principal clusters in the complex and determined their structure and extension. We constructed extinction-limited samples for five principal clusters and constructed K-band luminosity functions that we compare with those of artificial clusters with varying ages. This analysis provided mean ages and possible age spreads for the clusters. We found that IC 1795, the centermost cluster of the complex, still hosts a large fraction of young sources with circumstellar disks. This indicates that star formation was active in IC 1795 as recently as 2 Myr ago, simultaneous to the star-forming activity in the flanking embedded clusters, W3-Main and W3(OH). A comparison with carbon monoxide emission maps indicates strong velocity gradients in the gas clumps hosting W3-Main and W3(OH) and shows small receding clumps of gas at IC 1795, suggestive of rapid gas removal (faster than the T Tauri timescale) in the cluster-forming regions. We discuss one possible scenario for the progression of cluster formation in the W3 complex. We propose that early processes of gas collapse in the main structure of the complex could have defined the progression of cluster formation across the complex with relatively small age differences from one group to another. However, triggering effects could act as catalysts for enhanced efficiency of formation at a local level, in agreement with previous studies.Consejo Nacional de Ciencias y Tecnología (CONACYT) CB2010-15216

Heterogeneity in Monetary Transmission: Sectoral and Regional Effects

Different studies have analyzed monetary transmission in Chile, and the effects of monetary policy on aggregate macroeconomic variables. However, valuable information, relevant for the design and management of monetary policy, can be obtained in a more specific analysis of the impact of monetary shocks on the components of aggregate activity. Thus, this paper studies the disaggregate effects of monetary policy, distinguishing among three different classifications: private spending (consumption and investment), economic sectors and regional unemployment. The paper finds significant differences in the disaggregate impact (both in size and length) of monetary shocks. In most cases, these differences are consistent with the theoretical implications of traditional monetary transmission channels.

Nitrogen-carbon graphite-like semiconductor synthesized from uric acid

A new carbon-nitrogen organic semiconductor has been synthesized by pyrolysis of uric acid. This layered carbon-nitrogen material contains imidazole-, pyridine (naphthyridine)- and graphitic-like nitrogen, as evinced by infrared and X-ray photoelectron spectroscopies. Quantum chemistry calculations support that it would consist of a 2D polymeric material held together by hydrogen bonds. Layers are stacked with an interplanar distance between 3.30 and 3.36 Å, as in graphite and coke. Terahertz spectroscopy shows a behavior similar to that of amorphous carbons, such as coke, with non-interacting layers. This material features substantial differences from polymeric carbon nitride, with some characteristics closer to those of nitrogen-doped graphene, in spite of its higher nitrogen content. The direct optical band gap, dependent on the polycondensation temperature, ranges from 2.10 to 2.32 eV. Although in general the degree of crystallinity is low, in the material synthesized at 600 °C some spots with a certain degree of crystallinity can be found

Ultrastructurally-smooth thick partitioning and volume stitching for larger-scale connectomics

FIB-SEM has become an essential tool for studying neural tissue at resolutions below 10×10×10 nm, producing datasets superior for automatic connectome tracing. We present a technical advance, ultrathick sectioning, which reliably subdivides embedded tissue samples into chunks (20 µm thick) optimally sized and mounted for efficient, parallel FIB-SEM imaging. These chunks are imaged separately and then ‘volume stitched’ back together, producing a final 3D dataset suitable for connectome tracing

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO