2,805 research outputs found
Serological identification of virus in watermelon production fields in the Tocantins State.
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Afforestation of savannas: an impending ecological disaster.
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Previous issue date: 2017-02-06bitstream/item/180899/1/1-s2.0-S1679007316300779-main.pd
New order parameters in the Potts model on a Cayley tree
For the state Potts model new order parameters projecting on a group of
spins instead of a single spin are introduced. On a Cayley tree this allows the
physical interpretation of the Potts model at noninteger values q of the number
of states. The model can be solved recursively. This recursion exhibits chaotic
behaviour changing qualitatively at critical values of . Using an
additional order parameter belonging to a group of zero extrapolated size the
additional ordering is related to a percolation problem. This percolation
distinguishes different phases and explains the critical indices of percolation
class occuring at the Peierls temperature.Comment: 16 pages TeX, 5 figures PostScrip
Use of thermogravimetry analysis to quantify total volatile fraction in pine resin.
Pinus species exhibit fast growth and are good producers of wood, cellulose and resin. Brazil is the second largest producer of resin. The People?s Republic of China is the main producer with approximately 90% world?s resin production. Turpentine, volatile fraction, and rosin, solid fraction, are two major fractions or resin. The distillation process continues up to 170° C can be extracted about 95% of the total gum turpentine resin, preserving its constituents. There is little research using thermal analysis to study pine resin properties. This work involved evaporating volatile fraction of resins in an oven at 170 ÂșC consisted of 20 different samples from Pinus caribaea var. hondurensis and was compared with results obtained in thermal analysis to quantify the same fraction for each one. The volatile fraction in the oven (170 ÂșC) was from 14.69% to 24.05%. This fraction obtained through thermogravimetric analysis (TGA) was from 13.37% to 23.64%. The results demonstrate that the TGA technique is capable of accurately determining the volatile and non-volatile fractions of the resin and this technical proved to be suitable for further analyses.CBRATEC
Cry2A toxins from Bacillus thuringiensis expressed in insect cells are toxic to two lepidopteran insects.
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Cloning and expression of Aujeszky's disease virus glycoprotein E (gE) in a baculovirus system.
Projeto n. 03.03.23.20
Second Order Dissipative Fluid Dynamics for Ultra-Relativistic Nuclear Collisions
The M\"uller-Israel-Stewart second order theory of relativistic imperfect
fluids based on Grad's moment method is used to study the expansion of hot
matter produced in ultra-relativistic heavy ion collisions. The temperature
evolution is investigated in the framework of the Bjorken boost-invariant
scaling limit. The results of these second-order theories are compared to those
of first-order theories due to Eckart and to Landau and Lifshitz and those of
zeroth order (perfect fluid) due to Euler.Comment: 5 pages, 4 figures, size of y-axis tick marks for Figs. 3 and 4 fixe
Recoherence in the entanglement dynamics and classical orbits in the N-atom Jaynes-Cummings model
The rise in linear entropy of a subsystem in the N-atom Jaynes-Cummings model
is shown to be strongly influenced by the shape of the classical orbits of the
underlying classical phase space: we find a one-to-one correspondence between
maxima (minima) of the linear entropy and maxima (minima) of the expectation
value of atomic excitation J_z. Since the expectation value of this operator
can be viewed as related to the orbit radius in the classical phase space
projection associated to the atomic degree of freedom, the proximity of the
quantum wave packet to this atomic phase space borderline produces a maximum
rate of entanglement. The consequence of this fact for initial conditions
centered at periodic orbits in regular regions is a clear periodic recoherence.
For chaotic situations the same phenomenon (proximity of the atomic phase space
borderline) is in general responsible for oscillations in the entanglement
properties.Comment: 15 pages (text), 6 figures; to be published in Physical Review
Stochastic Quantization of Scalar Fields in de Sitter Spacetime
We consider the stochastic quantization method for scalar fields defined in a
curved manifold. The two-point function associated to a massive
self-interacting scalar field is evaluated, up to the first order level in the
coupling constant , for the case of de Sitter Euclidean metric. Its
value for the asymptotic limit of the Markov parameter is
exhibited. We discuss in detail the covariant stochastic regularization to
render the one-loop two-point function finite in the de Sitter Euclidean
metric
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