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This review explores the structure and biogenesis of bacterial flagella, highlighting their structural diversity in various bacterial models. It delves into how these structures, originating from a conserved structural flagellar nucleus (NEFC), have evolved to adapt to different functions and capabilities. This diversity plays a crucial role in each species' ability to thrive in specific ecological niches. The bacterial flagellar motor is a complex apparatus comprising a rotor and a stator embedded in the cell envelope. Recent advancements have revealed the incorporation of new components that enhance its functionality. These components include additional rings or discs beyond those found in the NEFC. These additional elements cover or interact with the basal body and stator, resulting in greater efficiency and rotational speed by facilitating the recruitment of more stators or stabilizing their connection to the rotor. Furthermore, variations are observed in the hooks or filaments, with modified flagellins that possess unique enzymatic properties. The increasing number of bacterial models studied, coupled with advanced visualization techniques such as cryo-microscopy, has unveiled the remarkable diversity in flagellar architecture. This, in turn, has led to a paradigm shift in our understanding of the assembly and operation of the flagellar motor. In conclusion, the field of bacterial flagellum research is experiencing a period of rapid progress, driven by a growing body of evidence and the development of innovative visualization techniques. This progress enhances our understanding of this vital bacterial structure and its role in bacterial adaptation and function. [ABSTRACT FROM AUTHOR]

The stator core of an electric machine for teaching applications, with 12 teeth and open slots, is used and a rotor, of sintered magnetic material, is constructed to configure a flux switching three-phase heteropolar inductor alternator. The optimization of the rotor design consists of obtaining the best number of teeth that provides a waveform of the output voltage closest to a sinusoidal function and with a higher effective value (rms). An analytical model is presented, allowing to establish a comparison of the values of the permeances, depending on the number of teeth of the rotor. Results are compared with simulation values, using a finite element program. The conclusion reached is that seven is the ideal number of teeth and slots of the rotor. [ABSTRACT FROM AUTHOR]

This paper presents a mathematical model to obtain a failure indicator of stator faults based on the negative sequence component of the electric current. The model can be used in online diagnosis systems to separate the effects of voltage unbalance factor and the constructive asymmetries of the machine. Results of the application of the model were validated trough laboratory tests made into a specially modified motor and results were applied to success diagnosis of two motors of higher electrical power. As a main result of the work, a low computational model was obtained to diagnose a quick evolution failure that can evolve quickly to a thermal collapse of the stator winding with consequent repair costs. [ABSTRACT FROM AUTHOR]