Hierarchical Poly Tree Configurations for the Solution of Dynamically Refined Finte Element Models

This paper demonstrates how a multilevel substructuring technique, called the Hierarchical Poly Tree (HPT), can be used to integrate a localized mesh refinement into the original finite element model more efficiently. The optimal HPT configurations for solving isoparametrically square h-, p-, and hp-extensions on single and multiprocessor computers is derived. In addition, the reduced number of stiffness matrix elements that must be stored when employing this type of solution strategy is quantified. Moreover, the HPT inherently provides localize 'error-trapping' and a logical, efficient means with which to isolate physically anomalous and analytically singular behavior

Finite element for rotor/stator interactive forces in general engine dynamic simulation. Part 1: Development of bearing damper element

A general purpose squeeze-film damper interactive force element was developed, coded into a software package (module) and debugged. This software package was applied to nonliner dynamic analyses of some simple rotor systems. Results for pressure distributions show that the long bearing (end sealed) is a stronger bearing as compared to the short bearing as expected. Results of the nonlinear dynamic analysis, using a four degree of freedom simulation model, showed that the orbit of the rotating shaft increases nonlinearity to fill the bearing clearance as the unbalanced weight increases

Bifunctional Lewis and Brønsted acidic zeolites permit the continuous production of bio-renewable furanic ethers

The catalytic valorisation of bio-renewable feedstock often relies upon multi-stage processing of highly-functionalised substrates, resulting in selectivity and processs engineering challenges. Herein, we demonstrate that a bifunctional zeolitic material, containing both Lewis and Brønsted acid sites in a single catalytic material, permits the continuous production of bio-renewable furanic ethers, such as (butoxy)methyl furan, which possess potential as fuel additives. In contrast to mono-functional catalysts and physical mixtures thereof, the bifunctional Sn- and Al-containing BEA zeolite results in uniquely-high levels of activity, selectivity and stability. Optimal results were obtained over a bifunctional catalyst containing 2 wt.% Sn and 0.5 wt.% Al, prepared by modified solid state incorporation, which was highly selective (> 75 %) to the deisred ether for over 107 h on stream, and for over 3000 substrate turnovers

Mercury's low‐degree geoid and topography controlled by insolation‐driven elastic deformation

©2015. American Geophysical UnionMercury experiences an uneven insolation that leads to significant latitudinal and longitudinal variations of its surface temperature. These variations, which are predominantly of spherical harmonic degrees 2 and 4, propagate to depth, imposing a long‐wavelength thermal perturbation throughout the mantle. We computed the accompanying density distribution and used it to calculate the mechanical and gravitational response of a spherical elastic shell overlying a quasi‐hydrostatic mantle. We then compared the resulting geoid and surface deformation at degrees 2 and 4 with Mercury's geoid and topography derived from the MErcury, Surface, Space ENvironment, GEochemistry, and Ranging spacecraft. More than 95% of the data can be accounted for if the thickness of the elastic lithosphere were between 110 and 180 km when the thermal anomaly was imposed. The obtained elastic thickness implies that Mercury became locked into its present 3:2 spin orbit resonance later than about 1 Gyr after planetary formation

The thermal state and interior structure of Mars

©2018. American Geophysical UnionThe present‐day thermal state, interior structure, composition, and rheology of Mars can be constrained by comparing the results of thermal history calculations with geophysical, petrological, and geological observations. Using the largest‐to‐date set of 3‐D thermal evolution models, we find that a limited set of models can satisfy all available constraints simultaneously. These models require a core radius strictly larger than 1,800 km, a crust with an average thickness between 48.8 and 87.1 km containing more than half of the planet's bulk abundance of heat producing elements, and a dry mantle rheology. A strong pressure dependence of the viscosity leads to the formation of prominent mantle plumes producing melt underneath Tharsis up to the present time. Heat flow and core size estimates derived from the InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) mission will increase the set of constraining data and help to confine the range of admissible models.DFG, 280637173, FOR 2440: Materie im Inneren von Planeten - Hochdruck-, Planeten- und Plasmaphysi

Atributos microbiológicos, físicos e químicos do solo em cultivos de mandioca sob manejo orgânico.

bitstream/item/66205/1/32001.pdfFERTBIO

Pesquisas participativas, construção de conhecimentos e socialização de tecnologias de base agroecológica em Mato Grosso do Sul, através de arranjos com Escolas Famílias Agrícolas.

Publicado também na: Revista Brasileira de Agroecologia, v. 6. n. 2, dez. 2011