Made available in DSpace on 2014-07-29T15:12:43Z (GMT). No. of bitstreams: 1 Dissertacao Thiago Eduardo Pereira Alves 2010.pdf: 1047109 bytes, checksum: dda1bfd56872ff259ec692829eb6e52b (MD5) Previous issue date: 2010-11-25 / In this work compounds Zn1-xFexO, with 0.00 ≤ x ≤ 0.09, were synthesized by combustion reaction method with two different heating processes, in a thermal blanket and muffle furnace. Chemical analysis of compounds was performed by atomic absorption spectroscopy (AAS) and Fourier transform infrared (FTIR). Structural analysis of the crystalline phase, the diameter of the crystallites and the lattice parameters were checked by X-ray diffraction (XRD, powder method) and refinement software (Unitt and powder X cell). The analysis of surfaces and morphologies were determined by adsorption and desorption of N2 (ASAP, BET model) and transmission electron microscopy (TEM). Finally, Magnetic measurements were performed by vibrating sample magnetometer (VSM). The stoichiometric determined by atomic absorption is in good agreement with the calculated value for all samples. The samples were synthesized in a thermal blanket which corresponds to the wurtzite crystal structure with no secondary phases. The samples synthesized in furnace had wurtzite crystal structure, however, showed a small sample to phase segregation above 5%. The second phases are found with spinel phase indicate that the formation of zinc ferrite. The data of thermal analysis, infrared and X-ray diffraction, we show that the synthesis product in blanket form moving slowly in several stages, while that in the synthesis furnace gets the product directly. We noted the tendency of the formation of smaller particles for the samples from the thermal blanket, as well as high surface areas for these samples, those prepared in a muffle grating. Images by transmission electron microscopy confirm the observations made by x-ray diffraction measurements of surface areas by BET model. The magnetic measurements show ferromagnetic phenomenon only for the sample produced in a muffle. The saturation magnetization was calculated by extrapolation, and their values are promising when compared with the literature. The Curie temperatures were estimated for some samples and all values were well above room temperature. / Neste trabalho compostos de Zn1-xFexO, com 0,00 ≤ x ≤ 0,09, foram sintetizados pelo método da reação de combustão por dois processos de aquecimento diferentes, em manta térmica e forno mufla. A análise química dos compostos foi realizada por espectroscopia de absorção atômica (AAS) e espectroscopia no infravermelho com transformada de Fourrier (FTIR). A análise estrutural da fase cristalina, o diâmetro dos cristalitos e os parâmetros de rede foram verificados por difração de raios X (XRD, método do pó) e softwares de refinamento (powder X e unitt cell). As análises das superfícies e morfologias foram realizadas por adsorção e dessorção de N2 (modelo de BET) e microscopia eletrônica de transmissão. Enfim, medidas magnéticas foram realizadas por magnetometria de amostra vibrante (VSM). A estequiometria determinada por absorção atômica está em boa concordância com o valor calculado para todas as amostras. As amostras sintetizadas em manta térmica apresentaram estrutura cristalina correspondente à wurtzita com ausência de fases secundárias. As amostras sintetizadas em forno mufla apresentaram estrutura cristalina wurtzita, porém, apresentaram uma pequena segregação de fases para amostra acima de 5%. As fases segregadas verificadas correspondem com a fase do espinélio que indicam a formação da ferrita de zinco. Os dados de análise térmica, infravermelho e difração de raios X, nos mostram que a síntese em manta forma o produto passando lentamente em várias etapas, ao passo, que a síntese em mufla obtém o produto de forma direta. Também foi observada a tendência da formação de menores partículas para as amostras provenientes da manta térmica, bem como, áreas superficiais elevadas para essas amostras, em relação àquelas preparadas em mufla. Imagens por microscopia eletrônica de transmissão comprovam as observações realizadas através da difração de raios x e das medidas de áreas superficiais por modelo de BET. As medidas magnéticas apresentaram fenômeno ferromagnético apenas para as amostra produzidas em mufla. As magnetizações de saturação foram calculadas por extrapolação, e seus valores são promissores quando comparados com a literatura. As temperaturas de Curie foram estimadas para algumas amostras e todas apresentaram valores bem acima da temperatura ambiente.

Embedded systems are commonplace, often with real-time requirements, limited resources and increasingly complex workloads with high demands on security and reliability. The complexity of these systems calls for extensive developer experience and many tools has been created to aid in the development of the software running on such devices. One of these tools, the Real-Time For the Masses (RTFM) concurrency framework developed at Luleå University of Technology (LTU), is built upon a pre-existing, well established and theoretically underpinned execution model providing deadlock free execution and strong guarantees about correctness. The framework is further enhanced by the memory safety provided by Rust, a modern systems programming language. This thesis documents the work done towards improving the framework by studying the possibility to make it extendable. For this, a model of the present layout is required, which in turn requires a solid understanding of Rust's way to structure code. To realise such a large structural change it was advisable to join the open-source RTFM community as a core developer. This role included new responsibilities and required work within different areas of the framework, not only directly related to the primary goal. It also provided the insight that in order to reach the desired extendable structure, many other improvements had to be done first, including the removal of large experimental features. To aid the development, usage of state of the art Continuous Integration testing (CI) were key. Changes to such systems are also part of the development process. The name of the project changed in the middle of this thesis work, going from RTFM to Real-Time Interrupt-driven Concurrency (RTIC). The implemented features and usability fixes detailed in this thesis improves the user experience for embedded system developers resulting in increased productivity while making the development process of such systems more accessible. These general improvements will be part of the next release of the framework. A version v0.6.0-alpha.0 of the framework has been released for testing. The experiences gained related to open-source project governance during this work are also presented.