Compositional Evolution And Magnetic Properties Of Nanocrystalline Fe 73.5cu1nb3si13.5b9

Melt-spun FeCuNbSiB ribbons were annealed at 540-550°C for various times (≤1 h). The development of a nanocrystalline structure was investigated by means of Mössbauer spectroscopy. From measured hyperfine fields and intensities the crystalline phase was inferred to be pure Fe 1-xSix, with x=0.18 after 1 h annealing. The residual amorphous volume fraction was determined to be ≅50%. With help of these results it has been possible to evaluate the amorphous contribution to magnetostriction in the nanocrystalline state. The development of a nanocrystalline structure was found to play a role in the main mechanisms of magnetic disaccommodation.711260086012Elfusa,Mineracao Jundu,Netzsc

The Influence Of Quenching Rate On Magnetic Properties Of Amorphous Ribbons

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Five sets of amorphous ribbons of the composition Fe73.5Cu 1Nb3Si13.5B9 produced with different quenching rates (QR) were studied in order to verify the influence of the topological disorder on magnetic properties. For this purpose several magnetic methods were applied. Significant differences have been found between the results of magnetic disaccommodation He·Δμ/μ, pinning field Hp and stress dependence of the magnetic permeability μ/μ0(σ) of as-cast materials produced at different QR. The values of He·Δμ/μ and Hp are directly proportional to the disorder degree of the samples. The μ/μ0(σ) curves display broad maxima, which are found to be related to the quenched-in stresses. In contrast with these results, no significant effects of the amorphous structure on the Curie temperature and Mössbauer spectra were found, because other parameters are dominating.7310660366052011/01071-3; FAPESP; São Paulo Research FoundationFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Desvelando a concepção de adolescência/adolescente presente no discurso da Saúde Pública

Este artigo é parte de uma Tese de Doutorado*. Trata-se de um trabalho de natureza teórica que, no campo das Ciências Sociais, busca analisar criticamente o conhecimento produzido e utilizado na área da saúde e que vem orientando a prática com adolescentes, de forma hegemônica, desvelando a concepção de adolescência/adolescente presente no discurso da Saúde Pública. Mediante um processo de desconstrução e reconstrução histórica do discurso em estudo, utilizando-se o instrumental de pesquisa em História Social, reconhece-se a concepção adotada, representativa do paradigma médico-biológico/ biomédico, que vem orientando, de forma predominante, a produção do conhecimento e as práticas correspondentes nessa área de atuação.The present paper is part of the PhD dissertation presented and defended in the Faculty of Public Health-USP in 1995. It is a theorical piece of work in the field of Social Sciences. It aims at a critical analysis of the knowledge produced and used in the health area that has hegemonically directed the practice with adolescents uncovering the concept of adolescent/adolescence present in the Public Health discourse. The adopted conception is recognized by means of a historic deconstruction and reconstruction of the discourse under study with the use of the Social History research tools. Such conception represents the biomedical paradigm that has predominantly guided the production of knowledge and corresponding practices in the areas