Abstract

Flywheel systems are attractive in hybrid and electric vehicles due to their ability to handle power during acceleration and braking. The combination of a flywheel device with a battery source has several advantages such as high peak power capacity, high energy density and reduction in the number of charge/discharge cycles of the battery. A flywheel based all-electric driveline is investigated in this thesis. The novelty of the system consists in the use of a double wound flywheel machine, which divides the system in two different power levels. Due to this configuration, the system becomes efficient and can handle the power developed during fast dynamical processes. The complete driveline consists of three main components: the battery, the flywheel machine and the wheel motor. The High-Power (HP) side of the driveline connects the flywheel machine to the wheel motor, whereas the Low-Power (LP) side connects the flywheel machine to the battery. The connections of different components of the system are made electrically through power converter devices. The present thesis focuses on the electrical converters and control strategies used in the flywheel based all-electric driveline. The control of power converters is responsible for the logic and functionality of the driveline, being a challenging step within this project. Different power converter topologies have been investigated: a DC/DC plus a DC/AC converter on the LP side, and an AC/DC/AC converter on the HP side. The design and assembly of the power electronics and their control scheme have been successfully implemented. Different control strategies have been suggested and a complete scaled driveline has been assembled and tested based on previous simulation results. Results have confirmed the functionality of the driveline, where smoothed output power has been obtained from the battery, whereas the flywheel handles power transients on the traction side. An average efficiency of about 87% (battery to wheels) has been obtained. The power converter systems have been shown to be efficient and robust, with control strategies able to handle the peak energy flow in the system. A regenerative braking strategy has been simulated and a wheel-to-wheel efficiency of about 80% has been estimated.

Abstract

Inadequate management of domestic wastewater in rural areas, the discharge of which to water bodies without prior treatment, is a major problem of environmental pollution, as well as a risk to public health. The purpose of this study was to assess the efficiency in the removal of organic matter by lombrifilters in domestic wastewater in a rural area. Under experimental conditions, the wormfilter was designed using as a theoretical basis the Tohá treatment system, created by Dr. José Tohá, which consisted of four strata: sawdaught + Eisenia foetida, activated charcoal, gravel and river stones. The concentration of organic matter of the tributary was evaluated obtaining high concentrations of BOD5, COD, TSS and TS. T1 achieved the highest efficiency percentages with a volumetric flow of 1.8×10-2 l/s and TRH of 0.92 h obtaining 52.25 % for BOD5 and COD, 66.74 % TSS and 52.91 % TS. In this way, it was determined that the implementation of wormfilters based on Eisenia foetida for the removal of organic matter, represents an ecological and innovative treatment system that requires a low investment, is efficient and friendly to the environment.

Abstract

The social audience emerges with the simultaneous exposure to television and social networks. Through them the audience voices its opinions or interests about the contents in real time. This information is of great value for the advertising strategy. By analyzing the presence of social audiences in the most effective commercial communication campaigns, this study makes evident the common elements and variables used by them. The 23 campaigns awarded in the Efficacy Awards, granted by the Asociación Española de Anunciantes, in the category of media and tactical action, from 2014 to 2018 are examined. Social conversation is detected in 15 cases, although only four campaigns link television content to social media, including social audience in their public strategies. Accordingly, the use of the social audience is scarce but a favorable progression in the strategies is observed, since they gain in transmediality and agents’ participation. Engagement is pursued and branded content, gamification or multiplication of official transmitters is used. The latest cases reveal how they take advantage of these audiences.