1,818 research outputs found

    English translation of Tierra... with an introduction

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    La glosa que escribió en latín Gregorio Lopez

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    Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-2010Precede al tít.: Código de las siete PartidasVól. II y III: Imprenta de F. Maroto e Hijo

    Las reformas liberales en El Salvador y sus implicaciones en el poder municipal, 1871-1890

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    Este trabajo pretende entender el proceso de centralización del poder y construcción del Estado en El Salvador durante el último tercio del siglo xix a partir de las relaciones entre el poder central —léase Ejecutivo— y el poder local representado por las municipalidades. En la primera parte se da un panorama general del contexto histórico del período y luego se estudian aspectos puntuales de las «reformas liberales» que muestran de qué manera estas afectaron a las municipalidades. Para ilustrar esos cambios se estudiarán las milicias locales, los mecanismos de control sobre el poder municipal, las implicaciones municipales de la privatización de ejidos, y se fi nalizará con los esfuerzos de las municipalidades por defender su autonomía y obtener mayores recursos

    G345.45+1.50: An expanding ring-like structure with massive star formation

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    Ring-like structures in the ISM are commonly associated with high-mass stars. Kinematic studies of large structures in GMCs toward these ring-like structures may help us to understand how massive stars form. The origin and properties of the ring-like structure G345.45+1.50 is investigated through observations of the 13CO(3-2) line. The aim of the observations is to determine the kinematics in the region and to compare physical characteristics estimated from gas emission with those previously determined using dust continuum emission. The 13CO(3-2) line was mapped toward the whole ring using the APEX telescope. The ring is found to be expanding with a velocity of 1.0 km/s, containing a total mass of 6.9e3 Msun, which agrees well with that determined using 1.2 mm dust continuum emission. An expansion timescale of 3e6 yr and a total energy of 7e46 erg are estimated. The origin of the ring might have been a supernova explosion, since a 35.5 cm source, J165920-400424, is located at the center of the ring without an infrared counterpart. The ring is fragmented, and 104 clumps were identified with diameters of between 0.3 and 1.6 pc, masses of between 2.3 and 7.5e2 Msun, and densities of between 1.0e2 and 1.0e4 cm^-3. At least 18% of the clumps are forming stars, as is shown in infrared images. Assuming that the clumps can be modeled as Bonnor-Ebert spheres, 13 clumps are collapsing, and the rest of them are in hydrostatic equilibrium with an external pressure with a median value of 4e4 K cm^-3. In the region, the molecular outflow IRAS 16562-3959 is identified, with a velocity range of 38.4 km/s, total mass of 13 Msun, and kinematic energy of 7e45 erg. Finally, five filamentary structures were found at the edge of the ring with an average size of 3 pc, a width of 0.6 pc, a mass of 2e2 Msun, and a column density of 6e21 cm^-2

    Outflows, envelopes, and disks as evolutionary indicators in Lupus YSOs

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    By studying 7 objects in the Lupus clouds we aim to test if a coherence exists between commonly used evolutionary tracers. We present ALMA observations of the continuum and molecular line emission that probe the dense gas and dust of cores and their associated molecular outflows. Our source selection in a common environment allows for a consistent comparison across different evolutionary stages. The quality of the ALMA molecular data allows us to reveal the nature of the molecular outflows by studying their morphology and kinematics. The images in IRAS15398-3359 appear to show that it drives a precessing episodic jet-driven outflow with at least 4 ejections separated by periods of time between 50 and 80 years, while data in IRAS16059-3857 show similarities with a wide-angle wind model also showing signs of being episodic. The outflow of J160115-41523 could be better explain with the wide-angle wind model as well, but new observations are needed to explore its nature. We find that the most common evolutionary tracers are useful for broad evolutionary classifications, but are not consistent with each other to provide enough granularity to disentangle different evolutionary stage of sources that belong to the same Class. Outflow properties used as protostellar age tracers (mass, momentum, energy, opening angle) may suffer from differences in the nature of each outflow, thus detailed observations are needed to refine evolutionary classifications. We found both AzTEC-lup1-2 and AzTEC-lup3-5 to be in the pre-stellar stage, although the latter could be more evolved. IRAS15398-3359, IRAS16059-3857 and J160115-41523, which have clearly detected outflows, are Class 0 sources, although we are not able to determine which is younger and which is older. Sz102 and Merin28 are the most evolved sources and show signs of having associated flows, not as well traced by CO as for the younger sources.Fil: Vazzano, María Mercedes. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Fernandez Lopez, Manuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Plunkett, Adele. National Radio Astronomy Observatory; Estados UnidosFil: de Gregorio Monsalvo, Itziar. European Southern Observatory Chile.; ChileFil: Santamaría Miranda, Alejandro. European Southern Observatory Chile.; ChileFil: Takahashi, Satoko. Joint Alma Observatory; ChileFil: Lopez, Cristian. Joint Alma Observatory; Chil

    Modeling dominant height growth including site attributes in the GADA approach for Quercus faginea Lam. in Spain

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    Aim of the study: To develop a site index model for Quercus faginea Lam. stands.Area of study: SpainMaterial and Methods: Data from 81 growth series collected in plots where Q. faginea was the main species were used for modelling. Different generalized algebraic difference equations (GADA) were fitted from traditionally used models. Richards model was selected and used to expand the parameters with environmental variables.Research highlights: Winter rainfall (WR), annual potential evapotranspiration (PET) and pH were introduced increasing the prediction ability of the GADA. It is strongly recommended to apply the model with ages lower than 80 years because the lack of data above that age makes bias increase and efficiency decrease.Keywords: Site index; Lusitanian oak; environmental variables

    New design parameters for biparabolic beach profiles (SW Cadiz, Spain)

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    165 profiles of seventy-one beaches along the Gulf of Cadiz (SW, Spain) were studied to improve the formulation of the beach profile in tidal seas. Maritime climate, degree of energy exposure and size of the sand grains were taken into account to study the two sections of the biparabolic profile. The objective of the study was the determination of more accurate formulations of the design parameters for the equilibrium profile that involves tidal seas. These formulations were modelled and validated based on existing profiles to quantify the error existing between the real profile and the modelling. This comparative analysis was extended by considering the formulations proposed by other authors. The best results were obtained with the proposal presented herein

    XANES Study Of The Radiation Damage On Alkanethiolates-Capped Au Nanoparticles

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    The radiation damage during XANES experiments on alkanethiols capped gold nanoparticles has been investigated. Different carbon length chains and nanoparticle sizes have been studied. Changes in the spectra after 45 minutes of irradiation, using a bend magnet, were observed for chains with more than 6 carbon atoms and are associated with the cleavage of S-C bonds and formation of atomic sulphur on the nanoparticle surface.Fil: Ramallo Lopez, Jose Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Giovanetti, Lisandro Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Visentin, F. C.. Centro Nacional de Pesquisa Em Energia E Materiais; BrasilFil: Requejo, Felix Gregorio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; Argentin

    Compost obtained from feces of dairy cattle vs. fertilizer on triticale production (X Triticum secale Wittmack)

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    El uso de abono es cada vez más frecuente en la agricultura por su efecto positivo sobre la fertilidad del suelo. El objetivo del presente estudio fue determinar la altura de planta, número de tallos por m2, longitud foliar, número de hojas por tallo y rendimiento de materia seca de triticale (X Triticum secale Wittmack), fertilizado con abono (humus de lombriz y ácidos húmicos) y urea. Los tratamientos fueron: humus de lombriz, ácidos húmicos, urea, humus de lombriz + urea, ácidos húmicos + urea y testigo. Se utilizó un diseño completo al azar, con 6 tratamientos y 3 repeticiones, en unidades experimentales de 60 m2 y densidad de siembra de 100 kg de semilla por ha. Los mayores resultados de producción indican que la combinación de la fertilización orgánica e inorgánica fue mejor que los demás tratamientos (p<0,05), sin embargo, no hubo diferencias en las propiedades bromatológicas (p>0,05). La producción de triticale en los tratamientos con urea fue hasta un 70% superior al testigo y a los tratamientos únicamente con abonos.The use of compost obtained from feces is increasingly common in agriculture for soil fertility, the objective of this study was to determine the plant height, number of stems per m2, leaf length, number of leaves per stem and dry matter yield of triticale (X Triticum secale Wittmack), fertilized with compost (humus and humic acids) and urea. A complete randomized design was used with 6 treatments and 3 replications in experimental units of 60 m2 and seeding density of 100 kg of seed per ha. The treatments were: humus, humic acids, urea, humus + urea, humic acids + urea and control. The higher production indicate that the combination of organic and inorganic fertilization was better than the other treatments (p <0.05), however, there were no differences in the bromatological properties (p> 0.05). The production of triticale in treatments with urea was up to 70% higher than the control and anothers treatments evaluated.Fil: Beltrán Santoyo, Miguel Ángel. Universidad Autónoma de San Luis Potosí (México)Fil: Álvarez Fuentes, Gregorio. Universidad Autónoma de San Luis Potosí (México)Fil: García Lopez, Juan Carlos. Universidad Autónoma de San Luis Potosí (México)Fil: Castro Rivera, Rigoberto

    Wave farm planning through high-resolution resource and performance characterization

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    Wave farm planning in a coastal region should lead to the selection of: i) the type of technology of wave energy converter (WEC) providing the highest performance at specific sites and ii) the sites for wave farm operation allowing an integrated coastal zone management (ICZM). On these bases, the deployment of a wave farm should be based on an accurate analysis of the performance of different WECs at coastal locations where wave energy exploitation does not interfere with other coastal uses, and the environmental impact is minimised (or positive, e.g. allowing coastal protection). With this in view, in this piece of research the intra-annual performance of various WECs of the same type (buoy-type) is computed at different locations in NW Spain allowing an ICZM perspective. For this purpose, the intra-annual version of WEDGE-p® (Wave Energy Diagram Generator – performance) tool is implemented. The results show that, as opposed to previous analysis on WECs with different principle of operation, the level of performance of buoy-type WECs at specific locations may present strong similarities. In this case, an accurate computation of different performance parameters along with their joint analysis emerge as a prerequisite for an informed decision-making
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