Different properties of Mg-Cu alloys have been studied by using Monte Carlo (MC) simulation and embedded-atom method (EAM) interatomic potentials. The interatomic potentials were derived by fitting to properties of crystalline phases. The pair distribution function g(r) has been calculated showing that a crystal, an amorphous solid, a supercooled liquid, or a liquid can be produced. The RSD (root mean square displacements) have been calculated for the same temperatures and compositions. The Radial Distribution Function (RDF) let us carried out structural analyses. We have been able to reproduce the experimentally measured structural properties of the liquid with potentials fitted to the solid state. The chemical potential is obtained from calculation and thermodynamic properties are derived. Examples studied are the free energy of mixing for liquid and solid alloys. The integral excess free energy, the thermodynamic activities and the activity factors of Mg and Cu were calculated. A good agreement with experimental results is obtained for the theoretical calculations.

Diferentes propiedades de aleaciones de Mg-Cu se estudiaron usando simulación de Monte Carlo y el método del átomo implantado de potenciales interatómicos(EAM). Los potenciales interatómicos fueron derivados por ajuste a las propiedades de fases cristalinas. La función de distribución de pares g(r) calculada indicó que un cristal, un sólido amorfo, un líquido sobreenfriado o un líquido pueden ser producidos. The RSD ha sido calculado para las mismas temperaturas y composiciones. La función de distribución radial (RDF) permitió realizar análisis estructurales. Se reprodujeron las propiedades estructurales medidas experimentalmente del líquido con potenciales ajustados al estado sólido. El potencial químico se obtuvo por cálculo y se derivaron propiedades termodinámicas. Se estudiaron la energía libre de mezclado para líquidos y aleaciones sólidas. Se calcularon el exceso de energía libre integral, las actividades termodinámicas y los factores de actividad de Mg y Cu. Se obtuvo una buena concordancia entre los resultados experimentales y los cálculos teóricos.

The concept of ExB flow velocity shear suppression is utterly fundamental in modern fusion research. It is asserted that there are models enabling to understand the physics involved in LH transitions. To improve the understanding of the mechanisms leading to the formation of Transport Barriers, especially the relation between Internal and Edge barriers it is necessary to invoke the issue of electric fields. Edge transport barriers are the feature of the H-mode, the baseline regime of ITER, whereas Internal Transport Barriers are used to develop regimes that might be employed for steady state operation of ITER , definitely beneficial for design and operation of fusion power plants in the future. Their synergy will be addressed. Plasma flows are closely connected to electric fields. Therefore, their role is crucial for understanding of tokamaks aimed at the achievement of fusion energy. This appears in the well known neoclassical theory as the most accomplished and selfconsistent basis for understanding of fusion plasmas. It pertains to the novel concept of "zonal flows" emerging from the recent development of gyro-kinetic transport codes. The equilibrium poloidal and toroidal flows are also crucial for the concept of the electric field shear suppression of plasma turbulence in tokamaks. Yet, this timely and topical issue has remained largely unaddressed experimentally because of great difficulties in measuring flows in plasmas.

General metrics of large aspect ratio tokamaks is used in the paper. General expressions for the neoclassical poloidal plasma rotation <img src="http:/img/fbpe/bjp/v32n1/03eq01.gif"> and radial ion heat flux gammaTi are obtained. Their dependence on the squared Mach number alpha = <img src="http:/img/fbpe/bjp/v32n1/03eq02.gif" align="absMiddle"> is analyzed (here Uzetai is the ion toroidal velocity and c s is the sound velocity, respectively). Some interesting peculiarities of this dependence are emphasized.

São descritas as principais etapas de uma técnica simples e sensível para a pesquisa, na mesma placa, do antígeno, do anticorpo e de imunocomplexos específicos baseada no "Enzyme-Linked Immunosorbent Assay" (ELISA). A técnica se mostrou de grande utilidade na pesquisa do antígeno, do anticorpo e de imunocomplexos específicos no soro de pacientes com esquistossomose hépato-intestinal crônica.

The main steps of a sensitive and quantitative technique for the simultaneous determination, in the same microplate, of antigen, antibody and specific immune complexes has been described. The assay involved principles of the double sandwich technique used in the "Enzyme-Linked Immunosorbent Assay" (ELISA). The technique proved to be useful for the estimation of antigen, antibody and specific immune complexes in sera of patients with human chronic hepato-intestinal schistosomiasis.

Foram realizados experimentos com camundongos SW albinos, para se estabelecer a comparação entre diferentes vias de infecção por cercárias do S. mansoni: inoculação subcutânea, infecção percutânea em três áreas distintas e injeção intraperitoneal. Os animais foram infectados simultaneamente com cercárias de um mesmo lote. A avaliação da infecção foi realizada 45 dias após, por perfusão do sistema porta hepático e mesentérico e contagem dos vermes recuperados. Com base nos resultados obtidos podemos dizer que a infecção percutânea na região abdominal se mostrou a mais eficiente, seguida pela infecção subcutânea. Com relação às infecções intraperitoneal e percutânea pela cauda, concluímos que são semelhantes entre si porém diferem muito, das duas primeiras. Mais um grupo experimental foi incluído neste trabalho, seguindo-se a mesma metodologia utilizada nos grupos anteriores. O objetivo das experiências complementares foi a avaliação comparativa da eficiência da via percutânea no pavilhão da orelha em relação a via subcutânea. A influência do sítio da pele, utilizado na infecção pela via percutânea, foi também discutida.

Experiments were carried out with Sw albino mice and it was concluded that the percutaneous route via abdominal skin was significatively more efficient than tail immersion method and subcutaneous infection; the subcutaneous injection was significatively more efficient than the percutaneous infection through the tail; this latter and the intraperitoneal injection, resulted in similar infections, but were significatively less efficient than the others. Significative difference was also observed in the comparison between the subcutaneous route and percutaneous infection through ear pinna. The influence of the site of skin infection by percutaneous route was also discussed.

Pesquisas realizadas em camundongos Sw, não singeneicos, mostraram não ter havido correlação entre a intensidade da reação granulomatosa pulmonar e o grau de resistência adquirida contra a infeccção por S.mansoni induzida pelo BCG.

Studies carried out in Sw outbred mice showed that there is no correlation between the degree of lung granulomatous reaction and the level of acquired resistance against S. mansoni infection induced by BCG.

Avaliou-se em coelhos e camundongos, a atividade imunogênica e protetora de um extrato antigênico de Schistosoma mansoni, obtido pela estocagem de vermes adultos em solução salina tamponada (Extrato Salino). A imunização dos animais determinou o desenvolvimento de resposta imune celular e humoral, avaliada por provas específicas. Todos os coelhos imunizados com ES, desenvolveram altos níveis de anticorpo citotóxico (91 a 100%), determinados pela avaliação da atividade citotóxica in vitro, contra esquitossômulos. Concluiu-se que os coelhos e camundongos imunizados com o extrato salino apresentaram diminuição da carga parasitária oriunda da infecção posterior com cercárias do S. mansoni, em relação aos controles. Os percentuais de proteção foram de 88.6% e 54% para os animais vacinados (coelhos e camundongos respectivamente).

The immunogenic and protective activity of an extract of S. mansoni, obtained by incubation of viable adult worms in buffered saline, was evaluated in rabbits and mice. Animal immunization with this extract resulted in the development of both humoral and cellular immune response. All immunized rabbits developed high levels (91 to 100%) of cytotoxic antibodies as determined by in vitro assays of cytotoxic activity of their sera against viable schistosomules. Immunized animals challenged with S. mansoni cercariae showed a lower parasite load than that of normal controls. Protective activity was 88.6% and 54.0% in immunized rabbits and mice, respectively.