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Marburg, Universiẗat, Diss., 2005.

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Abstract Key words: ferrite process, extend type of ferrite process, elutriation The way, treating waste liquid in laboratory, currently is almost the sending to treatment factory run by the local people after collecting classification. For a long time in collection and the various sources in production of the above liquid, the waste from laboratory displays not having large variation of component but also knowing hardly the true constitution. Thus, to achieve the objective of a proper treatment is not easy in truth In this work, a ferrite process (denoted by FP) was used to develop a method that could completely treat the waste liquid of laboratory containing heavy metal in solutions. The waste liquid synthesized with ten common ions of heavy metal such as Cd, Cu, Pb, Cr, Zn, Ag, Hg, Ni, Sn and Mn for each concentration of 0.002 M, and total concentration of heavy metal mixed in solution was 0.02 M. The performance of treatment in FP was judging by that the concentration of all heavy metals in filtered solution and the heavy metal containing in sediment sludge should be both below the regulations of effluent standards and TCLP standards. It was found that the conventional FP could not meet the goal of performance. As a result, we develop the type of extend reaction of FP to improve the performance of conventional FP. The base of theory was to maintain enough concentration of ferrous ion for beneficial reaction going continuously. We found that extend type FP accurately did improve the sludge quality to meet the TCLP standards and the plus-adding was better than the continuous-adding in two kinds of dosage input into reactor, but it would raise the operation cost for overextended reaction. Thus, we designed a wash-cleaning method to decrease the cost and to confirm a further quality of sludge in extend FP. Base on the achievements of this study, combining the commercial technology of ion exchange, we recommended a complete flow-chart to the user or plant owner to design the treatment plant.

L'effet magnétoélectrique (ME) est la modification de la polarisation électrique par l'application d'un champ magnétique (effet ME direct), ou bien la modification de l'aimantation magnétique par l'action d'un champ électrique (effet ME inverse).L'utilisation de matériaux composites permet de reproduire de manière extrinsèque cet effet. Le couplage mécanique entre des matériaux magnétostrictifs et piézoélectriques fournit un effet ME extrinsèque plus important à température ambiante que celui fournit intrinsèquement. Nous avons dégagé (théoriquement et expérimentalement) différentes caractéristiques de matériaux nécessaires à l'obtention d'un effet ME important et justifé l'utilisation de ferrite et de PZT dans les composites ME. Nous expliquons dans cette thèse, les méthodes de fabrications des différentes géométries de composites étudiées (empilement de couches ou bien inclusions d'une phase dans l'autre). En particulier, l'utilisation du frittage non conventionnel par Spark Plasma Sintering, pour améliorer le couplage mécanique y est abordée. En nous focalisant sur la géométrie en multicouche, nous avons montré l'importance de facteurs tels que le champ démagnétisant ou encore la symétrie de la structure. Nous présentons un prototype de capteur de courant utilisable en génie électrique. Nous en avons montré sa bonne linéarité et sensibilité, mais aussi ses défauts en terme de bande passante. / The magnetoelctric (ME) response consists in the modification of the electric polarization by an applied magnetic field (direct effect) or the modification of the magnetic polarization by an applied electric field (inverse effect). Intrinsic multiferroics are rather uncommon and the effect is often weak at room temperature. An alternative route to achieve ME effect, consists in using magnetostrictive and piezoelectric materials and coupling the two phases by mechanical stress. We draw (theoretically and experimentally) some material characteristics to achieve an importantME effect, which justify the use of ferrite and PZT. We describe the production process of the two studied connectivity schemes (stack of layers or inclusion of a phase in another). We focus on the sintering by Spark Plasma Sintering as a potential improvement of the mecanical bonding. We devoted a part of our work on multilayer composite and showed the importance of some factors such as the demagnetizing effect or the symmetry of the structure. We introduce a current sensor prototype suitable for electrical engineering application. We showed its good linearity and sensitivity but also some effects of its bandwidth.

<p>The effect of molybdenum on the isothermal proeutectoid ferrite reaction has been studied in low to medium (.05 - .43) carbon steels containing 1% molybdenum by weight. At 600 - 700°C molybdenum additions to steel result in the production of a dark etching ferrite constituent which has been shown to be heavily dislocated. The origin and stability of this transformation induced substrctures is considered.</p> <p>In these alloys the austenite twin boundaries are sites for nucleation of ferrite. A simple model to describe nucleation on twins has been constructed and consequences for the equilibrium shape of a ferrite crystal in austenite developed. The equilibrium shape was determined experimentally and the shape is commensurate with the model developed.</p> / Thesis / Master of Engineering (ME)

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International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / This paper describes a ferrite antenna that can produce any polarization on the Poincaré sphere over the frequency range of 9.0 to 11.4 GHz by utilizing Faraday rotation and a quarter-wavelength phase shifter. All possible polarizations of the electromagnetic wave are achievable with this antenna which includes linear, circular and elliptical polarizations. Any tilt angle of elliptical polarization and any orientation of the linear polarization can be achieved as well. The polarization of the ferrite antenna can be electronically switched to a different polarization instantly without the use of moving parts. An automatic data acquisition system was designed and built to fully analyze the antenna' s characteristics.

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