Imagen del niño Jesús [Material gráfico]

Inscripción: "Segun el cuadro que posee Dn. Pedro Pérez Conserge de la Real Academia de S. Carlos Dibujado y grabado p.r Mariano Sigüenza". En medio del texto anagrama "J.H.S."

Del Derecho del Niño al derecho a ser niño. La concepción de la infancia en una institución para 'chicos de la calle'

El Centro de Atención Integral a Niños y Adolescentes (CAINA-GCBA) se propone trabajar con los niños, niñas y adolescentes que se encuentran en situación de calle y que se acercan voluntariamente a la institución, desde la perspectiva de los Derechos del Niño. Más allá de las definiciones formales acerca de los destinatarios (de 8 a 18 años), es en las interacciones cotidianas entre las personas que allí trabajan y las que se acercan donde se ponen en juego de manera práctica los criterios para definir quiénes son los "chicos" que accederán a los recursos para la asistencia (y quiénes no), y cuál será el sentido de esa intervención. En este trabajo nos interesa recrear, a través del análisis de entrevistas al personal y de la observación participante de las interacciones entre éstos y los "chicos" que asisten, la manera en que desde esta institución se concibe el estatus social del "ser niño" (y sus características), y como consecuencia, se propone intervenir en una población en la que los atributos de esa infancia no aparecen como dados y evidentes

El Niño Southern Oscillation and Ross River Virus Outbreaks in Australia

Various authors have suggested a general predictive value of climatic indices of El Nino/Southem Oscillation events as indicators of outbreaks of arbovirus disease, particularly Ross River virus in Australia. By analyzing over 100 years of historical outbreak data on Ross River virus disease, our data indicate that, although high Southern Oscillation Index and La Nina conditions are potentially important predictors for the Murray Darling River region, this is not the case for the other four ecological zones in Australia. Our study, therefore, cautions against overgeneralization and suggests that, since climate and weather exert different influences and have different biological implications for the multiplicity of vectors involved, it is logical that predictors should be heterogeneous.

Redução in situ de NIO durante a sinterização de misturas NI/NIO produzidas por metalurgia do pó

The nickel alloys are widely used in the production of various materials, especially those that require mechanical strength characteristics associated with resistance to corrosion, for example, the stainless steel. Another use is the production of nickel alloy sintered from powder of metallic nickel. A promising alternative for the production of sintered components of nickel with an important reduction in costs of starting material is the use of mixtures of powders of Ni-NiO. This work aimed to study in situ reduction of NiO during sintering mixtures of Ni / NiO produced by powder metallurgy. The nickel mixtures have been processed by the technique of powder metallurgy and were pre-sintered in an oven under plasma reducing atmosphere of hydrogen. Mixtures Ni +15%NiO, Ni +25%NiO and Ni +35%NiO were studied and compared with samples consisting only of metallic Ni. Dilatometric tests were performed to study the sintering conditions of the mixtures. The consolidated material was analyzed for their microstructure and microhardness. Dilatometry graphs showed that the addition of nickel oxide in all compositions the active sintering the mixtures studied. In tests of microhardness indentations were made at different points of the sample surface. All compositions showed microhardness values close to the consolidated material from metallic nickel. However, sample containing Ni+35% NiO, showed a large dispersion of the values of microhardness tests performed at different points of the sample surface. Microstructural analysis of the material showed a higher concentration of voids and the presence of oxides in the waste composition of the mixtures Ni 35% NiO. The samples containing Ni+15%NiO showed microstructural characteristics and mechanical properties similar to metallic nickel consolidated under the same conditions of the compositions studied in this work and therefore had great potential for production of sintered nickel alloys

Compósitos NiO-CGO obtidos pelo método de síntese em uma etapa

Composite NiO-C0.9Gd0.1O1.95 (NiO-GDC), one of the materials most used for the manufacture of anodes of Cells Solid Oxide Fuel (SOFC) currently, were obtained by a chemical route which consists in mixing the precursor solution of NiO and CGO phases obtained previously by the Pechini method. The nanopowders as-obtained were characterized by thermal analysis techniques (thermogravimetry and Differential Scanning Calorimetry) and calcined materials were evaluated by X-ray diffraction (XRD). Samples sintered between 1400 and 1500 ° C for 4 h were characterized by Archimedes method. The effects of the composition on the microstructure and electrical properties (conductivity and activation energy) of the composites sintered at 1500 ° C were investigated by electron microscopy and impedance spectroscopy (between 300 and 650 ° C in air). The refinement of the XRD data indicated that the powders are ultrafine and the crystallite size of the CGO phase decreases with increasing content of NiO. Similarly, the crystallite of the NiO phase tends to decrease with increasing concentration of CGO, especially above 50 wt % CGO. Analysis by Archimedes shows a variation in relative density due to the NiO content. Densities above 95% were obtained in samples containing from 50 wt % NiO and sintered between 1450 and 1500 °C. The results of microscopy and impedance spectroscopy indicate that from 30-40 wt.% NiO there is an increase in the number of contacts NiO - NiO, activating the electronic conduction mechanism which governs the process of conducting at low temperatures (300 - 500 °C). On the other hand, with increasing the measuring temperature the mobility of oxygen vacancies becomes larger than that of the electronic holes of NiO, as a result, the high temperature conductivity (500-650 ° C) in composites containing up to 30-40 wt.% of NiO is lower than that of CGO. Variations in activation energy confirm change of conduction mechanism with the increase of the NiO content. The composite containing 50 wt. % of each phase shows conductivity of 19 mS/cm at 650 °C (slightly higher than 13 mS/cm found for CGO) and activation energy of 0.49 eV.

Hybrid density functional theory description of N- and C-doping of NiO

The large intrinsic bandgap of NiO hinders its potential application as a photocatalyst under visible-light irradiation. In this study, we have performed first-principles screened exchange hybrid density functional theory with the HSE06 functional calculations of N- and C-doped NiO to investigate the effect of doping on the electronic structure of NiO. C-doping at an oxygen site induces gap states due to the dopant, the positions of which suggest that the top of the valence band is made up primarily of C 2p-derived states with some Ni 3d contributions, and the lowest-energy empty state is in the middle of the gap. This leads to an effective bandgap of 1.7 eV, which is of potential interest for photocatalytic applications. N-doping induces comparatively little dopant-Ni 3d interactions, but results in similar positions of dopant-induced states, i.e., the top of the valence band is made up of dopant 2p states and the lowest unoccupied state is the empty gap state derived from the dopant, leading to bandgap narrowing. With the hybrid density functional theory (DFT) results available, we discuss issues with the DFT corrected for on-site Coulomb description of these systems.

Recent Changes in Central and Eastern Pacific El Niño

Recent research indicates that characteristics of El Niño and the Southern Oscillation (ENSO) have changed over the past several decades. Here, I examined different flavors of El Niño in the observational record and the recent changes in the character of El Niño events. The fundamental physical processes that drive ENSO were described and the Eastern Pacific (EP) and Central Pacific (CP) types or flavors of El Niño were defined. Using metrics from the peer-reviewed literature, I examined several historical data sets to interpret El Niño behavior from 1950-2010. A Monte Carlo Simulation was then applied to output from coupled model simulations to test the statistical significance of recent observations surrounding EP and CP El Niño. Results suggested that EP and CP El Niño had been occurring in a similar fashion over the past 60 years with natural variability, but no significant increase in CP El Niño behavior.

Educación, Higiene. Educación Física. Cultura Física. Ideas expuestas en el Segundo y Tercer Congreso del niño en Santa Fé, años 1935 y 1938

El presente trabajo se desprende del proyecto de investigación "La constitución histórica del campo de la cultura física y de la Educación Física. Actores, instituciones, discursos, políticas. Argentina (1901-1938)". Para el desarrollo del mismo se toma como fuente primaria el Segundo Congreso Provincial del Niño, realizado en Santa Fe en el año 1935 y Tercer Congreso Provincial del niño de Santa Fé en el año 1938. Se tratara de identificar ¿Qué bases científicas daban soporte a la formación docente y la enseñanza de la Educación Física escolar? ¿Qué importancia tuvieron las concepciones eugenésicas y fisiológicas en con relación a la Cultura Física y la Educación Física?

Educación, Higiene. Educación Física. Cultura Física. Ideas expuestas en el Segundo y Tercer Congreso del niño en Santa Fé, años 1935 y 1938

El presente trabajo se desprende del proyecto de investigación "La constitución histórica del campo de la cultura física y de la Educación Física. Actores, instituciones, discursos, políticas. Argentina (1901-1938)". Para el desarrollo del mismo se toma como fuente primaria el Segundo Congreso Provincial del Niño, realizado en Santa Fe en el año 1935 y Tercer Congreso Provincial del niño de Santa Fé en el año 1938. Se tratara de identificar ¿Qué bases científicas daban soporte a la formación docente y la enseñanza de la Educación Física escolar? ¿Qué importancia tuvieron las concepciones eugenésicas y fisiológicas en con relación a la Cultura Física y la Educación Física?