On Mechanical and Electrical Coupling Determination at Piezoelectric Harvester by Customized Algorithm Modeling and Measurable Properties

Piezoelectric harvesters use the actuation potential of the piezoelectric material to transform mechanical and vibrational energies into electrical power, scavenging energy from their environment. Few research has been focused on the development and understanding of the piezoelectric harvesters from the material themselves and the real piezoelectric and mechanical properties of the harvester. In the present work, the authors propose a behavior real model based on the experimentally measured electromechanical parameters of a homemade PZT bimorph harvester with the aim to predict its Vrms output. To adjust the harvester behavior, an iterative customized algorithm has been developed in order to adapt the electromechanical coupling coefficient, finding the relationship between the harvester actuator and generator behavior. It has been demonstrated that the harvester adapts its elongation and its piezoelectric coefficients combining the effect of the applied mechanical strain and the electrical behavior as a more realistic behavior due to the electromechanical nature of the material. The complex rms voltage output of the homemade bimorph harvester in the frequency domain has been successfully reproduced by the proposed model. The Behavior Real Model, BRM, developed could become a powerful tool for the design and manufacturing of a piezoelectric harvester based on its customized dimensions, configuration, and the piezoelectric properties of the smart materials.This research was funded by the Basque Government, grant number KK-2021/00082-µ4IIoT, and by the European Commission, grant number 869884- RECLAIM

Low-Cost Piezoelectric Sensors for Time Domain Load Monitoring of Metallic Structures During Operational and Maintenance Processes

The versatility of piezoelectric sensors in measurement techniques and their performance in applications has given rise to an increased interest in their use for structural and manufacturing component monitoring. They enable wireless and sensor network solutions to be developed in order to directly integrate the sensors into machines, fixtures and tools. Piezoelectric sensors increasingly compete with strain-gauges due to their wide operational temperature range, load and strain sensing accuracy, low power consumption and low cost. This research sets out the use of piezoelectric sensors for real-time monitoring of mechanical strength in metallic structures in the ongoing operational control of machinery components. The behaviour of aluminium and steel structures under flexural strength was studied using piezoelectric sensors. Variations in structural behaviour and geometry were measured, and the load and μstrains during operational conditions were quantified in the time domain at a specific frequency. The lead zirconium titanate (PZT) sensors were able to distinguish between material types and thicknesses. Moreover, this work covers frequency selection and optimisation from 20 Hz to 300 kHz. Significant differences in terms of optimal operating frequencies and sensitivity were found in both structures. The influence of the PZT voltage applied was assessed to reduce power consumption without signal loss, and calibration to μstrains and loads was performed.This research was funded by Basque Government, grant number KK-2019/00051-SMARTRESNAK and by the European Commission, grant number 869884- RECLAIM

Piezoelectric Actuators Mode of Vibration Influence on Energy Harvesting Applications

At this research, the authors have been focused on the mechanical and vibrational energy harvesting system with piezoelectric actuators. By studying the characteristics vibration modes of the piezoelectric harvester and the clamping setup configuration, a design optimization has been carried out in order to analized its influence on energy scavenging

Home Parenteral Nutrition in Spain, 2015. Home and Ambulatory Artificial Nutrition (NADYA) Group report

Aim: To communicate the results of the Spanish Home Parenteral Nutrition (HEN) registry of the NADYA-SENPE group for the year 2015.Material and methods: Data was recorded online by NADYA group collaborators that were responsible of the HPN follow-up from 1st January to 31st December 2015.Results: Two hundred and thirty-six patients with 243 episodes of NPD were recorded from 40 hospitals. This represents a rate of 5.08 patients/million habitants for 2015. The most frequent pathology in adults was other (26.3%) followed by palliative oncological (21.6%). The most common complication was catheter-related sepsis which presented a rate of 0.53 infections/1,000 days of HPN. Sixty-four episodes were finished; the main cause was death (43.7%) and resuming to oral via (32.8%).Conclusions: we find increasing centers and professional partners, responding to the progressively more patients with parenteral nutrition support at home. The main indications for the establishment of NPD and causes termination of treatment remain stable