On the Influence of Magnetic Fields on the Structure of Protostellar Jets

We here present the first results of fully three-dimensional (3-D) MHD simulations of radiative cooling pulsed (time-variable) jets for a set of parameters which are suitable for protostellar outflows. Considering different initial magnetic field topologies in approximate $equipartition$ with the thermal gas, i.e., (i) a longitudinal, and (ii) a helical field, both of which permeating the jet and the ambient medium; and (iii) a purely toroidal field permeating only the jet, we find that the overall morphology of the pulsed jet is not very much affected by the presence of the different magnetic field geometries in comparison to a nonmagnetic calculation. Instead, the magnetic fields tend to affect essentially the detailed structure and emission properties behind the shocks at the head and at the pulse-induced internal knots, particularly for the helical and toroidal geometries. In these cases, we find, for example, that the $H_\alpha$ emissivity behind the internal knots can be about three to four times larger than that of the purely hydrodynamical jet. We also find that some features, like the nose cones that often develop at the jet head in 2-D calculations involving toroidal magnetic fields, are smoothed out or absent in the 3-D calculations.Comment: 13 pages, 3 figures, Accepted by ApJ Letters after minor corrections (for high resolution figures, see http://www.iagusp.usp.br/~adriano/h.tar

A Receiver System for the TileCal Muon Signals

During the detector commissioning period, the TileCal muon signals have been used to trigger cosmic rays, as this signal, currently, is not being used by ATLAS level 1 muon trigger. Studies showed that the signal-to-noise ratio at the level 1 muon trigger is increased if both muon signals seeing the same D cell are summed. Thus, a system has been developed to receive TileCal muon signals and to aid ATLAS level 1 muon trigger. This article describes the receiver system and its main features, as well as circuit simulations

Empiricism and stochastics in cellular automaton modeling of urban land use dynamics

An increasing number of models for predicting land use change in regions of rapidurbanization are being proposed and built using ideas from cellular automata (CA)theory. Calibrating such models to real situations is highly problematic and to date,serious attention has not been focused on the estimation problem. In this paper, wepropose a structure for simulating urban change based on estimating land usetransitions using elementary probabilistic methods which draw their inspiration fromBayes' theory and the related ?weights of evidence? approach. These land use changeprobabilities drive a CA model ? DINAMICA ? conceived at the Center for RemoteSensing of the Federal University of Minas Gerais (CSR-UFMG). This is based on aneight cell Moore neighborhood approach implemented through empirical land useallocation algorithms. The model framework has been applied to a medium-size townin the west of São Paulo State, Bauru. We show how various socio-economic andinfrastructural factors can be combined using the weights of evidence approach whichenables us to predict the probability of changes between land use types in differentcells of the system. Different predictions for the town during the period 1979-1988were generated, and statistical validation was then conducted using a multipleresolution fitting procedure. These modeling experiments support the essential logicof adopting Bayesian empirical methods which synthesize various information aboutspatial infrastructure as the driver of urban land use change. This indicates therelevance of the approach for generating forecasts of growth for Brazilian citiesparticularly and for world-wide cities in general

Bananeira de coração branco: inovação para o mercado de ornamentais.

O presente trabalho teve como objetivo selecionar híbridos de bananeira ornamental com potencial de uso como plantas para vaso, paisagismo, flor de corte e minifrutos para arranjos florais. Cinquenta e dois híbridos oriundos de sete cruzamentos foram avaliados em três ciclos de produção. Para os caracteres quantitativos foram utilizados descritores para características vegetativas da planta (altura da planta, diâmetro do pseudocaule, número de perfilhos e número de folhas no florescimento); para características de cacho (comprimento do engaço, diâmetro do engaço, número de pencas por cacho, distância entre pencas, número de dedos por pencas, comprimento do fruto e diâmetro do fruto) e para inflorescência masculina (comprimento do coração e diâmetro do coração)

Testes de desinfestação para cultivo in vitro de variedades de Helicônia.

A acentuada procura por helicônias, principalmente por parte do mercado externo tem colocado o cultivo desse gênero de plantas em posição de destaque, dentre as atividades desenvolvidas no ramo da floricultura. A pouca oferta de mudas e a inexistência de mudas sadias prejudicam consideravelmente a expansão dessa cultura. A presença de microrganismos endofíticos, como a Pseudomonas sp., representa um empecilho no desenvolvimento de trabalhos de cultura de tecidos em helicônias.PDF. 124_11

Caracterização morfoagronômica de diferentes copas de maracujazeiro enxertadas em porta-enxerto de Passiflora gibertii.

Este trabalho teve como objetivo caracterizar morfoagronomicamente diferentes copas de maracujazeiro enxertadas em porta-enxertos de Passiflora gibertii, com vistas à seleção de copas superiores. Foi utilizado um porta-enxerto com 25 copas diferentes, previamente obtidos do trabalho de pesquisa desenvolvido pela equipe de Recursos Genéticos da Embrapa Mandioca e Fruticultura