Population dynamics of Chrysomya megacephala (Diptera : Calliphoridae) at different temperatures

In this study we analysed the theoretical population dynamics of C. megacephala, an exotic blowfly, kept at 25 and 30degreesC, using a density-dependent mathematical model, with parametric estimates of survival and fecundity in the laboratory. No change in terms of oscillation patterns was found for the two temperatures. The populations exhibited a two-point limit cycle, i.e. oscillations between two fixed points, at 25 and 30degreesC. However a quantitative change was observed, indicating that at 25degreesC the number of immatures in equilibrium is 1176 and at 30degreesC, 1944. The implications of this difference in terms of equilibrium for population dynamics of C. megacephala are discussed.

Intersubband plasmon-phonon modes in quantum wires at high temperatures

Coupled intersubband plasmon-phonon modes are studied in a multisubband parabolic quantum wire at room temperatures. These modes are found by calculating the spectral weight function which is related to the inelastic Raman spectra. We use a 13 subband model. The plasmon-phonon coupling strongly modifies the dispersion relation of the intersubband modes in the vicinity of the optical phonon frequency omega(LO). Extra modes show up as a result of the electron-phonon interaction. We carefully study the density and temperature dependence of these extra modes. We also show that coupled intersubband plasmon-phonon modes should be observed for temperatures as high as 300 K.

Three-boson recombination at ultralow temperatures

The effects of trimer continuum resonances are considered in the three-body recombination rate of a Bose system at finite energies for large and negative two-body scattering lengths (a). The thermal average of the rate allows to apply our formula to Bose gases at ultra-low temperatures. We found a good quantitative description of the experimental three-body recombination length of cesium atoms to deeply bound molecules up to 500 nK. Consistent with the experimental data, the increase of the temperature moves the resonance peak of the three-body recombination rate to lower values of vertical bar a vertical bar exhibiting a saturation behavior. (C) 2006 Elsevier B.V. All rights reserved.

Screened potential and quarkonia properties at high temperatures

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Extension of the Nambu-Jona-Lasinio model predictions at high densities and temperatures using an implicit regularization scheme

Traditional cutoff regularization schemes of the Nambu-Jona-Lasinio model limit the applicability of the model to energy-momentum scales much below the value of the regularizing cutoff. In particular, the model cannot be used to study quark matter with Fermi momenta larger than the cutoff. In the present work, an extension of the model to high temperatures and densities recently proposed by Casalbuoni, Gatto, Nardulli, and Ruggieri is used in connection with an implicit regularization scheme. This is done by making use of scaling relations of the divergent one-loop integrals that relate these integrals at different energy-momentum scales. Fixing the pion decay constant at the chiral symmetry breaking scale in the vacuum, the scaling relations predict a running coupling constant that decreases as the regularization scale increases, implementing in a schematic way the property of asymptotic freedom of quantum chromodynamics. If the regularization scale is allowed to increase with density and temperature, the coupling will decrease with density and temperature, extending in this way the applicability of the model to high densities and temperatures. These results are obtained without specifying an explicit regularization. As an illustration of the formalism, numerical results are obtained for the finite density and finite temperature quark condensate and applied to the problem of color superconductivity at high quark densities and finite temperature.

A generalized alternating-direction implicit scheme for incompressible magnetohydrodynamic viscous flows at low magnetic Reynolds number

This paper presents numerical simulations of incompressible fluid flows in the presence of a magnetic field at low magnetic Reynolds number. The equations governing the flow are the Navier-Stokes equations of fluid motion coupled with Maxwell's equations of electromagnetics. The study of fluid flows under the influence of a magnetic field and with no free electric charges or electric fields is known as magnetohydrodynamics. The magnetohydrodynamics approximation is considered for the formulation of the non-dimensional problem and for the characterization of similarity parameters. A finite-difference technique is used to discretize the equations. In particular, an extension of the generalized Peaceman and Rachford alternating-direction implicit (ADI) scheme for simulating two-dimensional fluid flows is presented. The discretized conservation equations are solved in stream function-vorticity formulation. We compare the ADI and generalized ADI schemes, and show that the latter is more efficient in simulating low Reynolds number and magnetic Reynolds number problems. Numerical results demonstrating the applicability of this technique are also presented. The simulation of incompressible magneto hydrodynamic fluid flows is illustrated by numerical solution for two-dimensional cases. (c) 2007 Elsevier B.V. All rights reserved.

Analytical study of the nonlinear behavior of a shape memory oscillator: Part I-primary resonance and free response at low temperatures

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Structure and Growth Kinetics of 3-Glycidoxypropyltrimethoxysilane-Derived Organic/Silica Hybrids at Different Temperatures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Enrichment of a continuous culture of Saccharomyces cerevisiae with the yeast Issatchenkia orientalis in the production of ethanol at increasing temperatures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Design of hierarchical porous aluminas by using one-pot synthesis and different calcination temperatures

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

MICROBIAL COUNTS of DARK RED LATOSOL SAMPLES STORED AT DIFFERENT TEMPERATURES

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of dietary organic selenium and zinc on the internal egg quality of quail eggs for different periods and under different temperatures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Abundance of MyoD and myostatin transcripts in chicken embryos submitted to distinct incubation temperatures and timing exposures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

MICROBIAL ACTIVITY of DARK RED LATOSOL SAMPLES STORED AT DIFFERENT TEMPERATURES

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Temperatura e substrato para o teste de germinação de sementes de barbatimão ((Stryphnodendron adstringens (Mart.) Coville (Leguminosae))

As normas oficiais para análise de sementes não estabelecem critérios para a execução de testes de germinação da maioria das espécies florestais. Assim, o objetivo deste trabalho foi a determinação do substrato, da temperatura e da necessidade de superação da dormência das sementes para o teste de germinação de Stryphnodendron adstringens. Foram avaliados o tratamento de escarificação com ácido sulfúrico por 60 min, os substratos vermiculita, rolo de papel, areia e solo e as temperaturas constantes de 20, 25, 30 e 35 ºC e alternadas de 15-35 ºC e 20-30 ºC, utilizando-se a primeira contagem de germinação (7 dias) e a porcentagem de plântulas normais, anormais, sementes mortas e dormentes (42º dia após a semeadura) com quatro repetições de 50 sementes. As sementes de S. adstringens devem ser submetidas ao teste de germinação, após superação da dormência, em substrato papel e nas temperaturas constantes de 25, 30 ou 35 ºC ou alternadas de 20-30 ºC.