Improving magnetic coupling for battery charging through 3D magnetic flux

The spatial distribution of the magnetic field and the coupling between the coils in the Wireless Power Transfer (WPT) systems is an important aspect to consider in the system design and efficiency optimization. The presented study in this paper is based on tests performed on a physical model. The transmitting (primary) equipment, is an electrical three-phase system, capable to be connected in star or delta (both electrically and geometrically). The measured results allow to describe graphically the magnetic field distribution in three dimensions. The analytical formulas aim to help to understand and to quantify the physical phenomena but they cannot be considered a universal approach and the measurement results help to understand better the observable facts. In the WPT, the key issues that will influence the efficiency, are the alignment of the coils, the spatial orientation of the magnetic field, the detachment and the tilt between the windings, all they changing the magnetic coupling between the transmitter and the receiver of energy. This research is directed not only to the magnetic field distribution but finally, to optimize the energy transfer efficiency.

Questionário de cooperação organizacional: Estudos diferenciais

O objectivo do presente trabalho foi verificar as diferenças entre grupos, quanto à cooperação, numa amostra de 300 funcionários de 70 Câmaras Municipais, nas variáveis tempo de trabalho, função desempenhada, área de trabalho, idade, sexo e habilitações académicas. Utilizámos o Questionário de Cooperação Organizacional. Não observámos diferenças significativas nas variáveis tempo de serviço, área de trabalho, idade, sexo e habilitações académicas em nenhum dos três factores do QCO (cooperação configurada por regulamentações formais, cooperação decorrente da interdependência de indivíduos únicos articulados entre si, e cooperação através da orientação para a sociedade dos contributos singulares). Na variável função desempenhada, não houve diferenças significativas no primeiro nem no terceiro factores. No segundo factor, observámos uma diferença significativa entre administrativos (que referem que se coopera pouco) e ocupantes de cargos de direcção e chefia (que referem que se coopera moderadamente). As variáveis estudadas não são, em geral, pertinentes para a diferenciação dos processos de cooperação. /ABSTRACT: The aim of this dissertation was to test the differences between groups, concerning cooperation, on a random sample with 300 workers from 70 municipalities, focusing on the variables working time, task, working department, age, gender and qualifications. We used the Questionnaire on Organizational Cooperation. No significant differences in the variables working time, working department, age, gender, and qualifications in any of the three dimensions of the QOC (cooperation shaped by formal regulations; cooperation arising from the interdependence of unique individuals articulated with one another; cooperation towards society, arising from the individual action) were found. We found no significant differences in the variable task, neither in the first nor in the third factor. ln the second factor, we observed a significant difference between clerks (who state that cooperation is little) and workers in leading and management positions (who state that cooperation is moderate). The variables that were studied are not generally relevant to the differentiation of the cooperation processes.