Classificação, metodologia de projeto e aplicação de retificadores multipulsos com conexão diferencial de transformador

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Controle de velocidade e tração de rodas independentes para veículos elétricos

This work presents a proposal to replace thetraditional system of traction electric car that usesone electric motor and a mechanical differential, by two electric motors of lower power, controlled byelectronic control low cost. The proposed control isopen loop and uses the technique of Pulse WidthModulation (PWM), discrete and synchronizedaiming to reduce the generation of harmonics. The implementation of two smaller motor one on each wheel-drive distributes the weight of the vehicle, improving the heat exchange of the windings,beyond enable the power components supporting a current of 50% predicted for only one motor . The solution adopted for being open-loop, has a similar behavior to the mechanical differential, where theeffort imposed by the trajectory makes the velocity distribution between the wheels be appropriate tovehicle trajectory

Microwave interferometric technique for characterizing few mode fibers

We propose and experimentally demonstrate a simple and accurate technique for measuring differential mode group delay (DMGD) in few mode fibers (FMF). A frequency-swept microwave signal is modulated on a filtered optical incoherent source. The microwave signals carried on different fiber modes experience different time delays and interfere with each other in the photodetector. Optical interference between propagating fiber modes is avoided by the use of an incoherent optical source. A mathematical model is established to analyze the interference pattern and extract the DMGD values. A 456-m two-mode fiber and a 981-m FMF, which supports four LP modes, are measured. The measurement covers the whole C-band and the results coincide well with those obtained by the time-of-flight method and the numerical simulations. A precision of ±0.002 ps/m is achieved.

Differential gene expression in drought-tolerant sugarcane roots

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)