Paulo Jose Abatti

The electric potential that exists across the cell membrane, known as resting potential at quiescent conditions, is fundamental to transport of nutrients, water, and salts to and fro the cell. This electric potential is usually attributed to the concentration gradients of ions and respective permeabilities across the membrane. The Goldman-Hodgkin-Katz (GHK) equation quantitatively describes this relationship. However, because it does not consider the active transport of ions carried out by the so-called ion pumps, GHK itself does not justify the stability of intracellular ionic concentrations over time. Furthermore, there are instances where GHK is not effective to calculate the cell membrane electric potential, e.g., when changes in the external potassium concentration modify the membrane potential. The objective of this work is to present the derivation of an equation that describes the membrane electric potential, including the action of ion pumps. The mathematical model proved to be able to reproduce adequately the experimental results available in the literature (correlation coefficient greater than 0.9469).

Two-coil wireless power transfer systems are composed of two circuits tuned at the same resonance frequency, one containing the source and the other containing the load, where both are connected to each other by a mutual inductance. The power delivered to the load circuit is divided by the total power supplied by the source or, alternatively, by the maximum ideal amount of power that can be delivered to the load circuit, are usual figures of merit known as efficiency and power transfer capability, respectively. Additionally, a third figure of merit can be defined as the power dissipated at the source circuit divided by total power supplied by the source. It has recently been demonstrated that efficiency and power transfer capability are related to this recently defined third figure of merit. In this paper, a simple method is presented to monitor the power dissipated at the source circuit divided by total power supplied by the source, which allows a determination of the efficiency and/or power transfer capability without a direct measurement at the load circuit. The advantages and limitations of the proposed method are discussed in detail. Practical results are included to verify the proposal.

In this paper, it is demonstrated that the efficiency and ability to transfer power to the load in three-coil wireless power transfer (WPT) systems are always higher than in equivalent four-coil ones. On the other hand, it is shown that there are features attainable in four-coil WPT system that are not in three-coil ones. For instance, in a four-coil WPT system, which can be divided into source, two communication, and load circuits, it is possible to devise a method for which the maximum power transferred to the load circuit or the maximum efficiency do not depend on the mutual inductance between the two communication coils, independently of the load resistance value. The necessary conditions to achieve the above feature together with the overall circuit analysis are discussed in details and practical results presented.

Two-coil wireless power transfer (WPT) systems are composed of two circuits tuned at the same resonance frequency, one containing the source, and other containing the load, both connected to each other by the mutual inductance. The power delivered to the load circuit (Po) divided by the total power supplied by the source (PT) and by the maximum ideal amount of power which can be delivered to the load circuit are usual figures of merit known as efficiency (n) and power transfer capability (P*), respectively. Additionally, it can be defined a third figure of merit (I*) as the power dissipated at the source circuit divided by PT. It has been recently demonstrated that n and P* are related to I* . In this paper, it is presented a simple method to monitor I*, allowing consequently the determination of n and/or P* without any direct measurement at the load circuit. The qualities and limitations of the proposed method are discussed in details. Practical results are included to verify the proposal.

Monitoring the ingestive behavior, especially rumination and eating, is important to assess animals’ health, welfare, needs, and to estimate production efficiency. In this paper, the myographic response of masticatory muscles was acquired from cows to directly access ingestive information (grazing and ruminating patterns) with high accuracy and time precision. Myographic signal processing is usually based on the same framework and optimal feature combinations have been extensively researched. However, recognition rates of hand-crafted feature based classifiers may be sensible to data deviation. In order to avoid the aforementioned issues and improve robustness, we propose an approach using sparse representation based classifiers which dismiss the need to select the best feature combination and classifier for the application. Also, we present a novel segmentation protocol to select chew related signal windows on cows. Four state-of-the-art multi-feature sets combined with linear discriminant analysis (LDA) were compared to a sparse representation based classifier called Fisher Discriminant Dictionary Learning (FDDL). Results suggest a significantly better performance of FDDL (p<0.05), achieving an accuracy rate of 90%, even in the presence of noise (0 - 20 dB), having a performance gain of 2.45% (SNR of 0 dB) in relation to the best hand-crafted feature set. When the noise was added just to the test set, all others classifiers remained under 75% (near 50%) for severe noise (0 - 10 dB), while FDDL stayed over 85%.

In this study, the analysis of a three‐coil wireless power transfer (WPT) system, which can be divided into source, communication and load circuits, is discussed in details. Among the three‐coil WPT systems features, it is demonstrated, for instance, that maximum efficiency ( ) and maximum power transferred to the load ( P _3MAX ) do not depend on the load resistance, neither on the mutual inductance between communication and load coils. In fact, it is shown that and P _3MAX depend only on source and communication circuits parameters. Practical results are also presented, showing good agreement with the developed theory and validating the proposed analysis.

Keywords Droplets; Nebulizers; Direct laminar incidence

Monitoring grazing ruminants ingestive behaviour has applications in measuring animal welfare, animal diseases detection and animal production system modelling. Current monitoring methods are mostly laborious, time expensive or invasive. In this work, it is presented a non-invasive method for chewing activity identification on goats by masseter muscle surface Electromyography (sEMG). Short-term chewing/resting time and chewing count were successfully predicted on male goats comparing to visual observation.