Corrosion protection is very significant for metals in modern society from the view of industrial development. This thesis work project involves a research study that is aimed to investigate the effect of corrosion on the mechanical strength and magnetic properties of four no treated or treated Somaloy® component samples (Somaloy®700 1P,  Somaloy®700 3P, Somaloy®700HR 5P and Somaloy®110i 5P) provided by Höganäs AB and laminated steel sheets by salt spray test. The coatings for protection are phosphoric acid coating, sodium silicate coating, DCA-Modified silicone conformal coating and water-borne single coat paint respectively. Then the protective properties are evaluated by Electrochemical Impedance Spectroscopy (EIS) in 0.1 mol/L NaCl solution after 7 days exposure.   From transverse rupture strength (TRS) and hysteresis loop measurements by salt spray test, although the bar samples are treated coating, the corrosion decreases the mechanical strength to a certain extent more or less over time. For the magnetic properties, the corrosive environments hardly influence the magnetic parameters of the no treated or four types of coatings treated Somaloy® components. But the all kinds of magnetic parameters for laminated ring samples have a great variation after salt spray test.   In the EIS measurements, for the no treated samples, the initial corrosion resistance is only several hundred ohms and decreases after 1 hour, 8 hours and 1day exposure, then increases to a certain extent with time due to the corrosion products formed on the surface. For the sodium silicate coating, the initial corrosion resistance is approximately several ten thousands ohms and decreases rapidly only after 1 day exposure to several hundred ohms due to the sodium silicate film dissolves in the electrolyte solution and has no effective protective property. Then the following corrosion process is almost same as the no treated samples. For the water-borne single coat paint, the initial corrosion resistance can reach to several Giga-ohms and decreases over time, but can still stay at  level, indicating that this coating has a very good and effective protective properties.   EIS experiments indicate that water-borne single coat paint has a more effective protection than sodium silicate coating and can apply a better corrosion protection for the Somaloy® components   Key words: corrosion protection, soft magnetic composites, phosphoric acid coating, sodium silicate coating, DCA-Modified silicone conformal coating , water-borne single coat paint, salt spray test, TRS, hysteresis loop, EIS

Recently, there has been an increasing interest in high school mathematics education, especially in the teaching and learning of calculus. For example, studies conducted by Bressoud (2010); Judson and Nishimori (2005); Koh and Divaharan (2011); and St. Jarre (2008) all looked at how to improve the understanding of calculus students and what roles the educator must take to ensure that their students are successful. The purpose of this study was to determine if there was a significant difference between instruction using computer algebra system (CAS) compared to instruction using the graphing calculator in high school calculus on students’ conceptual and procedural understanding. This study explored and compared two different types of instruction based on the use of two different types of technology, CAS and graphing calculator. The total population for this study consisted of 333 students. There were 187 students classified as using the graphing calculator and 146 students classified as using CAS. The data for this study were collected from four Advanced Placement (AP) calculus AB courses from high schools in Florida. The study used observations and two sets of calculus tasks in order to gather data. The research questions for this study looked at comparing the grades of students categorized based on the type of instruction received during the learning of calculus. The statistical procedure that was used was a simple oneway analysis of variance (ANOVA). The results indicated that there was no significant difference between the two types of instruction on the students’ procedural knowledge, iii however, there was statistical significance on the students’ conceptual understanding in favor of the CAS students. The study introduces a framework on how to obtain information about the effects of different types of instruction on students’ understanding of calculus. The results of this study contribute in assisting teachers and future researchers on how to analyze student work in order to obtain information about the students’ conceptual and procedural understanding of first semester calculus.

Made available in DSpace on 2016-08-03T12:29:27Z (GMT). No. of bitstreams: 1 Vanderli Duarte de Carvalho 1_194.pdf: 2604830 bytes, checksum: 6aae3c2066d9140325e0e1a05861f79c (MD5) Previous issue date: 2011-06-28 / A questão relacional na área da saúde envolve o imaginário sociocultural. Nos casos de mulheres com câncer de mama, denota um caráter emergencial em virtude do elevado número de ocorrências ou pela falta de percepção feminina da doença, o que dificulta a prevenção e o tratamento em tempo hábil. Este estudo pretende analisar como e de que maneira ocorrem e repercutem as práticas discursivas entre os profissionais da saúde e as pacientes com câncer de mama. Para isso, delineamos como pressupostos teóricos as barreiras da comunicação, seja interpessoal, intrapessoal e não verbal. A metodologia foi com base na Teoria das Representações Sociais de Serge Moscovici e no Discurso do Sujeito Coletivo (DSC) de Ana Maria Cavalcanti Lefévre e Fernando Lefévre. Nas análises dos relatos das mulheres com câncer de mama, identificamos conflitos de ordem sociocultural, como crenças, valores pessoais, estereótipos, enfim, distorções provenientes do senso comum e do imaginário coletivo, disseminadas nas representações da doença levadas a público pela mídia em geral. Nas considerações finais, constatamos que tais representações (estigmas sociais) interferem na relação com os profissionais de saúde, influenciando, assim, a adesão ao tratamento da doença. Os aspectos comunicacionais são aqui apontados de maneira tácita.