Preliminary criteria for internal acoustic environments of orbiting space stations

Maximum noise levels for manned orbiting space station

Estimate of nuclear technology engine test stand sound power and spectrum

Estimate of nuclear technology engine test stand sound power and spectru

Interactions of a shock wave with an entropy discontinuity

Disturbances caused by shock wave interactions with entropy discontinuity in turbulent flow

Análisis psicométrico de las escalas Ryff (versión española) en una muestra de adolescentes chilenos

Cuadra, IG (reprint author), Univ Talca, Talca, Chile.The present work examines the psychometric properties of the psychological well-being scale proposed by Ryff (Spanish version) in Chilean adolescents. The sample consisted of 335 adolescents from the city of Talca, Chile, who completed the scale of psychological well-being in its version of 39 items validated for Spanish population. Reliability and construct validity analysis was conducted, resulting in a good reliability value for the entire scale, although by dimensions it took values between acceptable and bad. Regarding construct validity, the model proposed by Ryff showed the best theoretical fit compared with alternatives. Both psychometric properties were improved by reducing the amount of items in the scale according to statistical criteria

Modeling the Galactic center gamma-ray emission with more realistic cosmic-ray dynamics

Very-high-energy gamma-ray observations of the Galactic center (GC) show extended emission that is strongly correlated with the morphology of the central molecular zone (CMZ). The best explanation for that emission is a hadronic interaction between cosmic rays (CRs) and ambient gas, where a CR central and continuous source accelerates protons up to 1 PeV ("PeVatron"). However, current models assume very simplistic CR dynamics. Our goal is to verify if more realistic CR dynamics for the GC environment are consistent with current gamma-ray observations, and whether they could be constrained by upcoming observations with the Cherenkov Telescope Array (CTA). We generated synthetic gamma-ray maps using a CR transport model with spherical injection, different diffusion regimes (in and out of the CMZ), polar advection, and mono-energetic particles of 1 PeV, and including different CR populations injected from the Arches, Quintuplet, and nuclear clusters of young massive stars, plus supernova Sgr A East. We adopted two different 3D gas distributions consistent with the observed gas column density, either with or without an inner cavity. In order to reproduce the existing observations detected by the High Energy Stereoscopic System (HESS), a ring-like gas distribution, with its mass set by the standard Galactic CO-to-H$_2$ conversion factor, and CR acceleration from all relevant sources are required. For a conversion factor one order of magnitude lower, injection rates that are ten times higher are needed. We show that CTA will be able to differentiate between models with different CR dynamics, proton sources, and CMZ morphology, owing to its unprecedented sensitivity and angular resolution. More realistic CR dynamics suggest that the CMZ has a large inner cavity and that the GC PeVatron is a composite CR population accelerated by the Arches, Quintuplet, and nuclear star clusters, and Sgr A East.Comment: Accepted for publication in A&A. 15 pages, 11 figure

The Envelope Attractor of Non-Strict Multivalued Dynamical Systems with Application To The 3D Navier-Stokes and Reaction-Diffusion Equations

Multivalued semiflows generated by evolution equations without uniqueness sometimes satisfy a semigroup set inclusion rather than equality because, for example, the concatentation of solutions satisfying an energy inequality almost everywhere may not satisfy the energy inequality at the joining time. Such multivalued semiflows are said to be non-strict and their attractors need only be negatively semi-invariant. In this paper the problem of enveloping a non-strict multivalued dynamical system in a strict one is analyzed and their attactors are compared. Two constructions are proposed. In the first, the attainability set mapping is extending successively to be strict at the dyadic numbers, which essentially means (in the case of the Navier–Stokes system) that the energy inequality is satisfied piecewise on successively finer dyadic subintervals. The other deals directly with trajectories and their concatenations, which are then used to define a strict multivalued dynamical system. The first is shown to be applicable to the three-dimensional Navier–Stokes equations and the second to a reaction–diffusion problem without unique solutions

Enfoques de investigación en problemas verbales aritméticos aditivos

A main field in the current research in Mathematics Education is the work with arithmetical word problem solving, which is both interesting and useful. There is ample previous work on this topic and it has received a very systematic treatment from different focuses. Researchers getting involved in this field need to know previous works and current focuses to clarify their research goals. In this study we offer a review about previous research done on difficulties with arithmetical word problems

Los recursos madereros. Condiciones socioeconómicas vinculadas con su aprovechamiento en la Provincia del Chaco

La actividad foresto-industrial atraviesa diferentes estratos sociales. Para entender su dinámica, primeramente debe conocerse su organización interna, es decir, quiénes forman parte de la misma. Cumplido este paso inicial de la investigación, se elaboró una caracterización de los componentes del sistema, enfatizándose en las condiciones socioeconómicas de cada grupo y, vinculado a ello, la situación de vulnerabilidad en la que se encuentran. Dentro de este escenario, los ámbitos que se han reconocido como demandantes de maderas (materias primas o insumos para el desarrollo de sus actividades) y otros asociados, donde se hallan los diferentes actores que nos interesa analizar, son los siguientes: la fábrica taninera, el aserradero y la carpintería de mediana dimensión, la pequeña fábrica, el sector asalariado, el taller de pulido, el acopio y reventa, el artesanado, la producción de leña, la fabricación de postes, la producción de carbón vegetal, la empresa de servicios diversificados, la fabricación de ladrillos, el sector transportista, el proveedor de recursos forestales y los sectores potenciales (fábrica de arrabio, pellets, espirales y aglomerados). Cada uno de estos componentes admiten subcategorías que exponen diferentes rasgos y grados de vulnerabilidad social y económica, que se analizan específicamente en esta investigación, a partir de un pormenorizado trabajo de campo que permitió la observación in situ y una diversidad de entrevistas abiertas y estructuradas a los distintos actores involucrados.

IMPACT OF PRECIPITATION CHARACTERISTICS IN NUTRIENT AND CARBON DELIVERY TO STREAMS IN ARTIFICIALLY DRAINED LANDSCAPES OF THE MIDWEST

Indiana University-Purdue University Indianapolis (IUPUI)Although many studies have investigated the impact of tile drainage on nitrate and pesticide export from cropland to streams, little information is known about the primary hydrological controls of tile flow response to precipitation events and its impact on N, P and C transport in artificially drained landscapes of the US Midwest. This study investigated 1) the relationship between precipitation characteristics and tile flow response at a high temporal resolution during storms; 2) the relative importance of macropore and matrix flow in tile flow and in N, P and C transport to tile drains; and 3) the impact of storm characteristics in N, P and C fluxes/export rates. The study was conducted between April and June 2008, in an agricultural tile drained soybean field, representative of agro-ecosystems of the US Midwest near Indianapolis, IN. For the 8 storms analyzed, results showed that bulk precipitation amount was the best predictor of mean and maximum tile flow, time to peak and runoff ratio. The contribution of macropore flow to total flow increased with precipitation amount, representing between 11% and 50% of total drain flow, with peak contributions between 15% and 74% of flow. For large storms (> 6 cm rainfall), cations data indicated a dilution of groundwater with new water as discharge peaked. Although no clear indication of dilution was observed for smaller storms (< 4 cm rainfall), macropore flow still contributed between 11% and 17% of total flow. For large storms, the transport of dissolved organic carbon (DOC), total phosphorous (TP) and soluble reactive phosphorus (SRP) was found to be regulated mainly by macropore flow while nitrate transport was regulated mainly by matrix flow. For smaller storms, macropore flow dominated DOC and TP transport while SRP and nitrate transport was dominated by matrix flow. These results significantly increase our understanding of the hydrological functioning of tile drained fields and its interaction with N, P and C transport in spring, which is the time of the year during which most water and N losses from tile drains occur in the Midwest