78 research outputs found
Do extrativismo à domesticação: o caso do bacurizeiro no Nordeste paraense e na Ilha de Marajó.
Caracterização de sistemas de manejo de bacurizeiro (Platonia insignis mart.) nas mesorregiões do Nordeste paraense e do Marajó, estado do Pará.
O bacurizeiro (Platonia insignis Mart.) Ă© uma espĂ©cie arbĂłrea de porte mĂ©dio a grande com aproveitamento frutĂfero, madeireiro e energĂ©tico, com centro de origem na AmazĂ´nia Oriental. Assume importância econĂ´mica nos estados do Pará, MaranhĂŁo e PiauĂ, onde se concentram densas e diversificadas populações naturais, em áreas de vegetação secundária. O objetivo deste estudo foi identificar e observar as práticas realizadas nos sistemas (extrativo, manejado e plantado) desenvolvidos pelos agricultores familiares das mesorregiões do Nordeste Paraense e MarajĂł, tendo em vista o seu potencial de crescimento como produto para agroindĂşstria e para a recuperação de áreas degradadas na AmazĂ´nia Oriental. A amostra foi constituĂda por 108 agricultores familiares das duas mesorregiões, todos georeferenciados com os quais foram abordados aspectos relativos Ă disponibilidade de bacurizeiros em seus estabelecimentos, o tipo de manejo e as práticas adotadas. Espera-se, com a adoção de manejo adequado desses sistemas, a transformação de roçados abandonados em pomares de bacurizeiros com espaçamento definido, os quais poderiam ser viabilizados mediante a utilização de linhas de crĂ©dito especĂficas
A comercialização do fruto de bacuri pela agricultura familiar no Nordeste paraense e ilha de Marajó, no Pará.
Molecular Dynamics Simulations
A tutorial introduction to the technique of Molecular Dynamics (MD) is given,
and some characteristic examples of applications are described. The purpose and
scope of these simulations and the relation to other simulation methods is
discussed, and the basic MD algorithms are described. The sampling of intensive
variables (temperature T, pressure p) in runs carried out in the microcanonical
(NVE) ensemble (N= particle number, V = volume, E = energy) is discussed, as
well as the realization of other ensembles (e.g. the NVT ensemble). For a
typical application example, molten SiO2, the estimation of various transport
coefficients (self-diffusion constants, viscosity, thermal conductivity) is
discussed. As an example of Non-Equilibrium Molecular Dynamics (NEMD), a study
of a glass-forming polymer melt under shear is mentioned.Comment: 38 pages, 11 figures, to appear in J. Phys.: Condens. Matte
Elastic Constants of Quantum Solids by Path Integral Simulations
Two methods are proposed to evaluate the second-order elastic constants of
quantum mechanically treated solids. One method is based on path-integral
simulations in the (NVT) ensemble using an estimator for elastic constants. The
other method is based on simulations in the (NpT) ensemble exploiting the
relationship between strain fluctuations and elastic constants. The strengths
and weaknesses of the methods are discussed thoroughly. We show how one can
reduce statistical and systematic errors associated with so-called primitive
estimators. The methods are then applied to solid argon at atmospheric
pressures and solid helium 3 (hcp, fcc, and bcc) under varying pressures. Good
agreement with available experimental data on elastic constants is found for
helium 3. Predictions are made for the thermal expectation value of the kinetic
energy of solid helium 3.Comment: 9 pages doublecolumn, 6 figures, submitted to PR
Does type of hospital ownership influence physicians' daily work schedules? An observational real-time study in German hospital departments
Background: During the last two decades the German hospital sector has been engaged in a constant process of transformation. One obvious sign of this is the growing amount of hospital privatization. To date, most research studies have focused on the effects of privatization regarding financial outcomes and quality of care, leaving important organizational issues unexplored. Yet little attention has been devoted to the effects of privatization on physicians' working routines. The aim of this observational real-time study is to deliver exact data about physicians' work at hospitals of different ownership. By analysing working hours, further impacts of hospital privatization can be assessed and areas of improvement identified.
Methods: Observations were made by shadowing 100 physicians working in private, for-profit or non-profit as well as public hospital departments individually during whole weekday shifts in urban German settings. A total of 300 days of observations were conducted. All working activities were recorded, accurate to the second, by using a mobile personal computer.
Results: Results have shown significant differences in physicians' working activities, depending on hospital ownership, concerning working hours and time spent on direct and indirect patient care.
Conclusion: This is the first real-time analysis on differences in work activities depending on hospital ownership. The study provides an objective insight into physicians' daily work routines at hospitals of different ownership, with additional information on effects of hospital privatization
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