Improving the quality of energy using an active power filter with zero direct power command control related to a photovoltaic system connected to a network

Introduction. This article’s subject is a dual function energy system that improves the quality of the electric energy with help of an active power filter and uses a new technique of command named ZDPC (Zero Direct Power Command) on one hand, and on the other hand it injects the photovoltaic (PV) renewable energy to the electrical networks in the presence of non-linear charges. The novelty of the work consists in the subtraction of disturbances resulting from the non-linear charges is provided by an active power filter based on a new ZDPC method. Methods. This strategy combines a classic PI controller for DC bus voltage regulation with a smart method to maximum power point tracking (MPPT) of power based on fuzzy logic. Purpose. The elimination of the undesirable harmonics from the source currents makes the current almost sinusoidal with a harmonic distortion rate close to 1 %. The injection of PV energy into the electrical grid is provided by a PV panel in series with a chopper through a two-state inverter. Results. This system is simulated using MATLAB/Simulink software. The results prove the robustness and feasibility of the ZDPC control which simultaneously guarantees the compensation of harmonic currents, the correction of the power factor and the injection of the solar power into the electrical grid.Вступ. Предметом цієї статті є енергосистема подвійного призначення, що покращує якість електроенергії за допомогою фільтра активної потужності та використовує, з одного боку, нову техніку управління під назвою ZDPC (Zero Direct Power Command), а з іншого боку, фотоелектричні відновлювані джерела енергії в електричні мережі за наявності нелінійних зарядів. Новизна роботи полягає в тому, що віднімання перешкод, що виникають від нелінійних зарядів, забезпечується фільтром активної потужності на основі нового методу ZDPC. Методи. Ця стратегія поєднує класичний ПІ-регулятор для регулювання напруги на шині постійного струму з інтелектуальним методом відстеження точки максимальної потужності (MPPT) на основі нечіткої логіки. Мета. Усунення небажаних гармонік із струмів джерела робить струм майже синусоїдальним з коефіцієнтом гармонічних спотворень, близьким до 1 %. Подача фотоелектричної енергії в електричну мережу забезпечується фотоелектричною панеллю, послідовно з’єднаної з переривником через інвертор з двома станами. Результати. Ця система моделюється за допомогою програмного забезпечення MATLAB/Simulink. Результати доводять надійність та здійсненність управління ZDPC, яке одночасно гарантує компенсацію гармонічних струмів, корекцію коефіцієнта потужності та подачу сонячної енергії в електричну мережу

QCALT: a tile calorimeter for KLOE-2 upgrade

The upgrade of the DA$\Phi$NE machine layout requires a modification of the size and position of the inner focusing quadrupoles of KLOE-2 thus asking for the realization of two new calorimeters covering the quadrupoles area. To improve the reconstruction of $K_L\to 2\pi^0$ events with photons hitting the quadrupoles a calorimeter with high efficiency to low energy photons (20-300 MeV), time resolution of less than 1 ns and space resolution of few cm, is needed. To match these requirements, we are designing a tile calorimeter, QCALT, where each single tile is readout by mean of SiPM for a total granularity of 2400 channels. We show first tests of the different calorimeter components

Feedback to align teacher and student in a Digital Learning Ecosystem

In this paper, we present an example of a Digital Learning Ecosystem, set up during the first period of the pandemic emergency and then remodelled and re-proposed for hybrid didactics provided afterwards, involving five pedagogical-didactic courses of two universities in central Italy. The central device in this Ecosystem was recursive feedback, which in contexts of didactics mediated by screens can anyhow activate discursive, adaptive, interactive and reflexive dynamics. In order to understand if these aims were pursued, we administered an open-ended questionnaire to 274 students, which was not intended to measure their enjoyment of the method and the environment, but their perceptions regarding the effectiveness of the system on their learning processes, not only at a cognitive level, but also on at an interpersonal and intrapersonal level. The analysis was conducted according to the Structural Topic Model, which allowed us to re-read the responses as a unique corpus of reflective writings, generated by the students after the input provided by the assigned task

Effect of Breed and Non-genetic Factors on Body Weight and Average Daily Gains of Goats in Tunisia

The present study was carried out to evaluate growth performance of three goat breeds in Tunisia (Alpine, Boer and Damascus) from birth to 90 days and to investigate the effect of non- genetic factors on birth weight (BW), weight at 10 days (W10), weight at 30 days (W30), weight at 70 days (W70), weight at 90 days (W90) and average daily weight gains from birth to 30 days (ADG0-30), from 10 to 30 days (ADG10-30), from 30 to 70 days (ADG30-70), from 30 to 90 days (ADG30-90), from 70 to 90 days (ADG7090). A total of 3198 goats including Alpine (n%253D1030), Boer (n%253D2084) and Damascene (n%253D84), born during the period 2004-2016 were used. Data analysis showed non-significant effect of breed on growth traits. However Damascus goats had the heaviest overall live weight at birth (3.99plusmn%253B0.05kg) followed by Alpine (3.94plusmn%253B0.02kg) and Boer (3.90plusmn%253B0.02kg) until 90 days (13.25plusmn%253B0.66, 12.13plusmn%253B0.35, 12.07plusmn%253B0.35kg respectively ).Average daily weight gains followed the same trend as weights. Overall, sex-type of birth, season and the combined year of birth-farm-herd influenced growth traits. Higher performances were recorded in males born as singles, during the rainy season (November to March), in 2007 and 2008, belonging to herd1of Chenchou experimental station and herd 5 belonging to a private farm respectively. In conclusion, our study confirms that non-genetic factors affect these three goat breeds. Adjustments for those factors are necessary to provide standard comparisons among breeds under challenging Tunisian conditions

The use ultrasound guided for refilling intrathecal baclofene pump in complicated clinical cases: A practical approach

Muscular spasticity due to neurological disorders is a heavy cause of severe pain and disability for many patients, compromising the independence and quality life. Baclofene is a good tool to guarantee patients independence and pain control. Anyway in chronic therapy oral treatment become unsatisfactory. In all these cases, intrathecal baclofen therapy (ITB), after sub fascial implantation of intrathecal pumps is used as an important long term treatment to reduce spasticity. After pump implantation the drug reservoir must be refilled periodically in order to maintain the reduction of spasticity and avoid the symptoms and signs of withdrawal. ITB refilling, which involves the insertion of a needle through the skin until the access port of the pump, is often hard, mainly due to the layer of abdominal fat, spasticity, suboptimal pump positioning, pump rotation or inversion, and scar formation over the implantation site. To avoid the difficulties of ITB refilling radiography or other invasive supportive examinations are sometimes needed. We reported here our experience and we suggest a simple method to use the ultrasound in refilling with particular attention to some cases with complications after implantation with a difficult approach in refilling. We used the ultrasound examination to identify the access port of her pump so as to avoid multiple needle punctures and infections and radiation exposition. Ultrasound-guided technique may facilitate ITB refill in technically challenging cases. With ultrasound ITB was easily detectable and was quite simple to identify the exact point of needle injection. In the last years different new applications for ultrasounds are emerging. In our opinion the use of Doppler ultrasounds in the study of muscles and nerves represent an emerging tool for the physician's neurological rehabilitation