Coherent properties and Rabi oscillations in two-level donor systems

Coherent properties and Rabi oscillations in two-level donor systems, under terahertz excitation, are theoretically investigated. Here we are concerned with donor states in bulk GaAs and GaAs-(Ga,Al)As quantum dots. We study confinement effects, in the presence of an applied magnetic field, on the electronic and on-center donor states in GaAs- (Ga,Al)As dots, as compared to the situation in bulk GaAs, and estimate some of the associated decay rate parameters. Using the optical Bloch equations with damping, we study the time evolution of the Is and 2p(+) states in the presence of an applied magnetic field and of a terahertz laser. We also discuss the role played by the distinct dephasing rates on the photocurrent and calculate the electric dipole transition moment. Results indicate that the Rabi oscillations are more robust as the total dephasing rate diminishes, corresponding to a favorable coherence time.

Confinement of spin-0 and spin-1/2 particles in a mixed vector-scalar coupling with unequal shapes for the potentials

The Klein - Gordon and the Dirac equations with vector and scalar potentials are investigated under a more general condition, V-v = V-s + constant. These isospectral problems are solved in the case of squared trigonometric potential functions and bound states for either particles or antiparticles are found. The eigenvalues and eigenfunctions are discussed in some detail. It is revealed that a spin-0 particle is better localized than a spin-1/2 particle when they have the same mass and are subjected to the same potentials.

DC and AC side harmonics in CCC converters

The capacitor-commutated converter (CCC) has frequently been used in the conception of HVDC systems connected to busbars with low short circuit level. This alternative arrangement, in substitution to the conventional ones, guarantees less sensitive operational conditions to problems related with the commutation failure in the inverters besides supplying part of the reactive energy to be compensated. Studies related with its performance in steady and transient states have been presented in several works, however its behavior as harmonic source is still little explored. This work presents preliminary studies focusing the generation of characteristic harmonics by this type of converter. Subjects related with the amplification of the harmonic magnitudes are investigated and compared considering similar arrangements of conventional static converters (LCC) and CCC schemes. It is also analyzed the harmonic generation on the dc side of the installation and its influence on the ac side harmonics. The results are obtained from simulations in the time domain in PSpice environment and they clearly illustrate the operational differences between the L CC and the CCC schemes with regard to characteristic harmonic generation.

Care cost for pregnant and parturient women with diabetes and mild hyperglycemia

OBJETIVO: Comparar custos de hospitalização e de atenção ambulatorial em gestantes/parturientes diabéticas e com hiperglicemia leve. MÉTODOS: Estudo observacional, prospectivo, quantitativo descritivo realizado em centro de diabete perinatal em Botucatu, SP, entre 2007 e 2008. Foram estimados os custos por absorção diretos e indiretos disponíveis na instituição e os custos específicos para a doença (medicamentos e exames). As 30 gestantes diabéticas tratadas com dieta foram acompanhadas em ambulatório e 20 tratadas com dieta mais insulina foram hospitalizadas. RESULTADOS: O custo da doença diabete (para a assistência pré-natal e parto) foi de US$ 3,311.84 para as gestantes hospitalizadas e de US$ 1,366.04 para as acompanhadas em ambulatório. CONCLUSÕES: Os custos diretos e indiretos e o custo total da assistência pré-natal foram mais elevados nas gestantes diabéticas hospitalizadas enquanto os custos da assistência ao parto e hospitalização para parto e puerpério foram semelhantes. Os custos da assistência pré-natal como no parto/puerpério foram superiores aos valores pagos pelo Sistema Único de Saúde.

What is a Fuzzy Bi-implication?

In order to make this document self-contained, we first present all the necessary theory as a background. Then we study several definitions that extended the classic bi-implication in to the domain of well stablished fuzzy logics, namely, into the [0; 1] interval. Those approaches of the fuzzy bi-implication can be summarized as follows: two axiomatized definitions, which we proved that represent the same class of functions, four defining standard (two of them proposed by us), which varied by the number of different compound operators and what restrictions they had to satisfy. We proved that those defining standard represent only two classes of functions, having one as a proper subclass of the other, yet being both a subclass of the class represented by the axiomatized definitions. Since those three clases satisfy some contraints that we judge unnecessary, we proposed a new defining standard free of those restrictions and that represents a class of functions that intersects with the class represented by the axiomatized definitions. By this dissertation we are aiming to settle the groundwork for future research on this operator.

Cost-benefit of hospitalization compared with outpatient care for pregnant women with pregestational and gestational diabetes or with mild hyperglycemia, in Brazil

CONTEXTO E OBJETIVO: Gestações complicadas pelo diabetes estão associadas com aumento de complicações maternas e neonatais. Os custos hospitalares aumentam de acordo com a assistência prestada. O objetivo foi calcular o custo-benefício e a taxa de rentabilidade social da hospitalização comparada ao atendimento ambulatorial em gestantes com diabetes ou com hiperglicemia leve. DESENHO do ESTUDO: Estudo prospectivo, observacional, quantitativo, realizado em hospital universitário, sendo incluídas todas as gestantes com diabetes pregestacional e gestacional ou com hiperglicemia leve que não desenvolveram intercorrências clínicas na gestação e que tiveram parto no Hospital das Clínicas, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista (HC-FMB-Unesp). MÉTODOS: Trinta gestantes tratadas com dieta foram acompanhadas em ambulatório e 20 tratadas com dieta e insulina foram abordadas com hospitalizações curtas e frequentes. Foram obtidos custos diretos (pessoal, material e exames) e indiretos (despesas gerais) a partir de dados contidos no prontuário e no sistema de custo por absorção do hospital e posteriormente calculado o custo-benefício. RESULTADOS: O sucesso do tratamento das gestantes diabéticas evitou o gasto de US$ 1.517,97 e US$ 1.127,43 para pacientes hospitalizadas e ambulatoriais, respectivamente. O custo-benefício da atenção hospitalizada foi US$ 143.719,16 e ambulatorial, US$ 253.267,22, com rentabilidade social 1,87 e 5,35 respectivamente. CONCLUSÃO: A análise árvore de decisão confirma que o sucesso dos tratamentos elimina custos no hospital. A relação custo-benefício indicou que o tratamento ambulatorial é economicamente mais vantajoso do que a hospitalização. A rentabilidade social de ambos os tratamentos foi maior que 1, indicando que ambos os tipos de atendimento à gestante diabética têm benefício positivo.

Prediction and probability of neonatal outcome in isolated congenital diaphragmatic hernia using multiple ultrasound parameters

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

Intracellular papillae of Actinocephalus (Eriocaulaceae-Poales) roots and their interaction with fungi: A light and transmission electron microscopy study

The genus Actinocephalus comprises 25 species and is restricted to Brazil, occurring mainly in the Espinhaco Mountains of Minas Gerais and Bahia States. Previous anatomical studies have reported the occurrence of intracellular papillae in the Actinocephalus roots, without dealing with their ultrastructure and function. The purpose of this paper is to investigate the structure, the composition and the probable function of the intracellular papillae of Actinocephalus roots, based on light microscopy, transmission electron microscopy and histochemical tests. The intracellular papillae occurred in all root tissues, from the rhizodermis to the vascular cylinder; they presented different forms and sizes and, ultrastructurally, they corresponded to material deposited between the cell wall and the plasma membrane. The histochemical tests carried out were positive for cellulose, pectin and callose. The intracellular papillae are responses of the plant cells to the interaction with fungi. They work as a physical barrier restricting fungal penetration, and they may also favor the supply of water and nutrients to the plant, since they increase root absorption surface. This might explain why the species of Actinocephalus are among the tallest Eriocaulaceae despite their reduced radicular system and the nutritional deficiency of the soil in which they grow. (C) 2006 Elsevier Ltd. All rights reserved.

Synchronization: Stability and duration time

We consider the problem of stability and duration of the synchronization process between self-excited oscillators, both in their regular and chaotic states. Making use of the properties of Hill equation describing the deviation between the slave and the master, we derive the stability conditions and expressions of the synchronization time. A fairly good agreement is obtained between the analytical and numerical results.

Low-energy direct muon transfer from H to Ne10+, S16+ and Ar18+ using the two-state close-coupling approximation to the Faddeev-Hahn-type equation

We perform a three-body calculation of direct muon-transfer rates from thermalized muonic hydrogen isotopes to bare nuclei Ne10+, S16+ and Ar18+ employing integro-differential Faddeev-Hahn-type equations in configuration space with a two-state close-coupling approximation scheme. All Coulomb potentials including the strong final-state Coulomb repulsion are treated exactly. A long-range polarization potential is included in the elastic channel to take into account the high polarizability of the muonic hydrogen. The transfer rates so-calculated are in good agreement with recent experiments. We find that the muon is captured predominantly in the n = 6, 9 and 10 states of muonic Ne10+, S16+ and Ar18+, respectively.

Zel'dovich's method of perturbation theory in quantum mechanics

Many years ago Zel'dovich showed how the Lagrange condition in the theory of differential equations can be utilized in the perturbation theory of quantum mechanics. Zel'dovich's method enables us to circumvent the summation over intermediate states. As compared with other similar methods, in particular the logarithmic perturbation expansion method, we emphasize that this relatively unknown method of Zel'dovich has a remarkable advantage in dealing with excited stares. That is, the ground and excited states can all be treated in the same way. The nodes of the unperturbed wavefunction do not give rise to any complication.

Mixing-demixing transition and collapse of a vortex state in a quasi-two-dimensional boson-fermion mixture

We investigate the mixing-demixing transition and the collapse in a quasi-two-dimensional degenerate boson-fermion mixture (DBFM) with a bosonic vortex. We solve numerically a quantum-hydrodynamic model based on a new density functional which accurately takes into account the dimensional crossover. It is demonstrated that with the increase of interspecies repulsion, a mixed state of DBFM could turn into a demixed state. The system collapses for interspecies attraction above a critical value which depends on the vortex quantum number. For interspecies attraction just below this critical limit there is almost complete mixing of boson and fermion components. Such mixed and demixed states of a DBFM could be experimentally realized by varying an external magnetic field near a boson-fermion Feshbach resonance, which will result in a continuous variation of interspecies interaction.

LARGE ATOMIC and NUCLEAR THREE-BODY SYSTEMS: SCATTERING and BINDING

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

Strong D* -> D pi and B* -> B pi couplings

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

TAXONOMY, ONTOGENY and PALEOECOLOGY of TWO SPECIES of HARBINIA TSAO, 1959 (CRUSTACEA, OSTRACODA) FROM THE SANTANA FORMATION, LOWER CRETACEOUS, NORTHEASTERN BRAZIL

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