Gaussian superpositions in scalar-tensor quantum cosmological models

A free scalar field minimally coupled to gravity model is quantized and the Wheeler-DeWitt equation in minisuperspace is solved analytically, exhibiting positive and negative frequency modes. The analysis is performed for positive, negative and zero values of the curvature of the spatial section. Gaussian superpositions of the modes are constructed, and the quantum bohmian trajectories are determined in the framework of the Bohm-de Broglie interpretation of quantum cosmology. Oscillating universes appear in all cases, but with a characteristic scale of the order of the Planck scale. Bouncing regular solutions emerge for the flat curvature case. They contract classically from infinity until a minimum size, where quantum effects become important acting as repulsive forces avoiding the singularity and creating an inflationary phase, expanding afterwards to an infinite size, approaching the classical expansion as long as the scale factor increases. These are non-singular solutions which are viable models to describe the early Universe.Comment: 14 pages, LaTeX, 3 Postscript figures, uses graficx.st

Uso de promotores de crescimento para cabritos leiteiros, fase de aleitamento.

A fase de aleitamento de cabritos leiteiros esta inserida no periodo de seu maior potencial de crescimento. Nesta fase, os animais sao susceptiveis as enterites (diarreias) de origem alimentar e/ou infecciosa, consideradas como a principais causas de baixo desempenho de cabritos. Assim, este experimento foi conduzido para avaliar o efeito de promotores de crescimento sobre o desempenho de cabritos leiteiros, na fase de aleitamento. Foram utilizados 30 crias, femeas, sendo 15 da raca Saanen e 15 da raca Anglo-Nubiana. Os animais foram aleitados com leite de vaca durante todo o periodo experimental e receberam capim elefante e concentrado ad libitum a partir de 15 dias de idade. Os tratamentos foram: T1= leite de vaca, T2= leite de vaca+salinomicina e T3= leite de vaca+probiotico. Os resultados mostraram que nao houve diferenca (P>0,05) entre tratamentos. Os valores encontrados para ganho de peso (g/animal/dia) e para peso ao desaleitamento (Kg) foram: 126,5 126,8, 122,4 e 10,2, 10,4 e 10,0, respectivamente. Nao foi observado ocorrencia de enterite nos animais. Entre raca, tambem, nao foi detectada diferenca (P>0,05) significativa. [Use of growth promotors for dairy kids, at the suckling phase]. The suckling phase of dairy kids is the period of higher potential for growth. In this phase, the animals are susceptible to the alimentary and infectious enteritis. These types of enteritis are the principal cause of low kid's performance. So, this experiment was carried out to evaluate the effect of growth promoters on performance of dairy kids during the suckling phase. Thirty females kids of the Anglo-nubiana breed (15) and of the Saanen breed (15) were used. The animals were artificially reared with cow milk, during the trial and they received napiergrass (Pennisetum purpureum) and concentrate ad libitum after 15 days of age. The treatments were T1 - cow milk, T2 - cow milk + salinomicine T3 - cow milk + probiotic. The results showed that there was no significant difference (P>0.05) among treatments and breed. The values to weight gain (g/animal/day) and wean weight (kg/animal) were 126.5, 126.8, 122.4 e 10.2, 10.4 e 10.0, respectively. There was not enteritis in animals

Liquid crystal phase and waterlike anomalies in a core-softened shoulder-dumbbells system

Using molecular dynamics we investigate the thermodynamics, dynamics and structure of 250 diatomic molecules interacting by a core-softened potential. This system exhibits thermodynamics, dynamics and structural anomalies: a maximum in density-temperature plane at constante pressure and maximum and minimum points in the diffusivity and translational order parameter against density at constant temperature. Starting with very dense systems and decreasing density the mobility at low temperatures first increases, reach a maximum, then decreases, reach a minimum and finally increases. In the pressure-temperature phase diagram the line of maximum translational order parameter is located outside the line of diffusivity extrema that is enclosing the temperature of maximum density line. We compare our results with the monomeric system showing that the anisotropy due to the dumbbell leads to a much larger solid phase and to the appearance of a liquid crystal phase. the double ranged thermodynamic and dynamic anomalies.Comment: 14 pages, 5 figure

Evaluation of water and sucrose diffusion coefficients during osmotic dehydration of jenipapo (Genipa americana L.).

The apparent diffusion coefficients for sucrose and water during osmotic dehydration of jenipapos were determined. Long time experiments (up to 60 h) were carried out in order to determine equilibrium concentrations inside jenipapos, whereas short time experiments (up to 4 h) were performed to provide detailed information on kinetics of water loss and solids gain at the beginning of osmotic treatment. According to the result, mass transfer rates for water and solutes, as well as the apparent diffusion coefficients for sucrose showed to be dependent on sucrose concentration in osmotic solution. The immersion time did not have significant effect (p>0.05) over the diffusion coefficients for sucrose and water

Brazilian sedimentary zeolite use in agriculture.

Zeolites are hydrated crystalline aluminosilicate minerals of alkaline and alkaline earth metals, structured in rigid three dimension nets, organized by AlO4 and SiO4 tetrahedral and are of natural occurrence. This report describes the characterization and application of the Brazilian zeolitic sedimentary rock as a release fertilizer and soil conditioner. The characterization of the head samples showed that it is composed of the zeolite stilbite intermixed with a smectitic clay mineral, and quartz. A low-cost quartz separation technique was established. Enrichment of concentrated natural zeolite was carried out: zeolite + KNO3, zeolite + K2HPO4 and zeolite + H3PO4 + apatite and the concentrated zeolite. These materials were tested with Rangpur lime rootstock and an experiment was also carried out with successive crops grown on the same substrate: lettuce, tomato, rice, and Andropogon grass. The results indicated that N, P and K enriched zeolite was an adequate slow-release source of nutrients to plants. Other green house and field experiments with concentrated zeolite applied with urea showed reduction of losses of ammonia by volatilization and improved in N use efficiency by maize. Concentrated zeolite also increased water retention and the available water capacity of a sand soil

The Consistency of Causal Quantum Geometrodynamics and Quantum Field Theory

We consider quantum geometrodynamics and parametrized quantum field theories in the framework of the Bohm-de Broglie interpretation. In the first case, and following the lines of our previous work [1], where a hamiltonian formalism for the bohmian trajectories was constructed, we show the consistency of the theory for any quantum potential, completing the scenarios for canonical quantum cosmology presented there. In the latter case, we prove the consistency of scalar field theory in Minkowski spacetime for any quantum potential, and we show, using this alternative hamiltonian method, a concrete example where Lorentz invariance of individual events is broken.Comment: Final version. See also http://www.cosmologia.cbpf.b