Energy management based on a fuzzy controller of a photovoltaic/fuel cell/Li-ion battery/supercapacitor for unpredictable, fluctuating, high-dynamic three-phase AC load

Introduction. Nowadays, environmental pollution becomes an urgent issue that undoubtedly influences the health of humans and other creatures living in the world. The growth of hydrogen energy increased 97.3 % and was forecast to remain the world’s largest source of green energy. It can be seen that hydrogen is one of the essential elements in the energy structure as well as has great potential to be widely used in the 21st century. Purpose. This paper aims to propose an energy management strategy based a fuzzy logic control, which includes a hybrid renewable energy sources system dedicated to the power supply of a three-phase AC variable load (unpredictable high dynamic). Photovoltaic (PV), fuel cell (FC), Li-ion battery, and supercapacitor (SC) are the four sources that make up the renewable hybrid power system; all these sources are coupled in the DC-link bus. Unlike usual the SC was connected to the DC-link bus directly in this research work in order to ensure the dominant advantage which is a speedy response during load fast change and loads transient. Novelty. The power sources (PV/FC/Battery/SC) are coordinated based on their dynamics in order to keep the DC voltage around its reference. Among the main goals achieved by the fuzzy control strategy in this work are to reduce hydrogen consumption and increase battery lifetime. Methods. This is done by controlling the FC current and by state of charge (SOC) of the battery and SC. To verify the fuzzy control strategy, the simulation was carried out with the same system and compared with the management flowchart strategy. The results obtained confirmed that the hydrogen consumption decreased to 26.5 g and the SOC for the battery was around 62.2-65 and this proves the desired goal.Вступ. В даний час забруднення навколишнього середовища стає актуальною проблемою, яка, безперечно, впливає на здоров’я людини та інших істот, які живуть у світі. Зростання водневої енергетики збільшилося на 97,3 %, і прогнозувалося, що вона залишиться найбільшим у світі джерелом зеленої енергії. Видно, що водень є одним із найважливіших елементів у структурі енергетики, а також має великий потенціал для широкого використання у 21 столітті. Мета. У цій статті пропонується стратегія управління енергоспоживанням, заснована на нечіткому логічному управлінні, яка включає гібридну систему відновлюваних джерел енергії, призначену для живлення трифазного змінного навантаження змінного струму (непередбачувана висока динаміка). Фотоелектричні (PV), паливні елементи (FC), літій-іонні батареї та суперконденсатори (SC) – це чотири джерела, з яких складається відновлювана гібридна енергосистема; всі ці джерела підключені до шини постійного струму. На відміну від звичайних застосувань,ув цій дослідницькій роботі SC був підключений до шини постійного струму безпосередньо, щоб забезпечити домінуючу перевагу, що полягає в швидкому реагуванні при швидкій зміні навантаження та перехідних режимах навантаження. Новизна. Джерела живлення (PV/FC/батареї/SC) координуються на основі їхньої динаміки, щоб підтримувати напругу постійного струму біля свого еталонного значення. Серед основних цілей, досягнутих стратегією нечіткого управління у цій роботі, - зниження споживання водню та збільшення терміну служби батареї. Методи. Це робиться шляхом керування струмом FC та станом заряду (SOC) батареї та SC. Для перевірки стратегії нечіткого управління було проведено моделювання з тією самою системою та порівняння зі стратегією блок-схеми керування. Отримані результати підтвердили, що споживання водню знизилося до 26,5 г, а SOC для батареї становило близько 62,2-65, що доводить досягнення бажаної мети

Construction and Test of a Flux Modulation Superconducting Machine for Aircraft

International audienceThe increasing of drives towards More Electric Aircraft (MEA) or the development of electric propulsion aircraft calls for MW-class electrical machines with more compact and power dense designs. One way is to explore the use of superconducting materials to create a high magnetic field in order to reduce the mass of ferromagnetic components. This paper presents the construction and the test of a brushless axial flux superconducting machine. The brushless topology satisfies the aeronautics industry requirements in terms of maintenance, while the axial configuration ensures an optimal use of the anisotropic HTS tapes. The machine is classed as partially superconducting, only the inductor is made with superconducting materials. A special design concerning the use of a stationary cryostat is presented. This improvement reduces significantly the electromagnetic air-gap length. A 50kW prototype is manufactured with a minimal mass objective. The prototype constitutes a first step to a scale-up MW-class machine design

Pharmacy students' attitudes toward pharmaceutical care in Qatar

Objectives: The study objectives were to investigate Qatar pharmacy students' attitudes toward pharmaceutical care (PC), to identify the factors that influence their attitudes, and to recognize their perceived barriers for PC provision. Methods: A cross-sectional and online survey of Qatar pharmacy students was conducted. Results: Over 4 weeks, 46 surveys were submitted (88% response rate). All respondents agreed that the pharmacist's primary responsibility is to prevent and resolve medication therapy problems. Most respondents believed that PC provision is professionally rewarding and that all pharmacists should provide PC (93% and 91% of respondents, respectively). Highly perceived barriers for PC provision included lack of access to patient information (76%), inadequate drug information sources (55%), and time constraints (53%). Professional year and practical experience duration were inversely significantly associated with four and five statements, respectively, out of the 13 Standard Pharmaceutical Care Attitudes Survey statements, including the statements related to the value of PC, and its benefit in improving patient health and pharmacy practitioners' careers. Conclusion: Qatar pharmacy students had positive attitudes toward PC. Efforts should be exerted to overcome their perceived barriers.Scopu

Seminar sejarah lokal: sastra dan sejarah lokal

Buku ini berisi kumpulan tulisan dari seminar sejarah lokal yang berisi "Sastra sejarah dan penulisan sejarah lokal", "Sumbangan karya sastra sejarah terhadap sejarah lokal di indonesia", "Karya sastra sebagai sumber sejarah", dan "Sastra dan sejarah lokal"

Therapeutic concentrations of antidepressants inhibit pancreatic beta-cell function via mitochondrial complex inhibition

Diabetes mellitus risk is increased by prolonged usage of antidepressants (ADs). Although various mechanisms are suggested for their diabetogenic potential, whether a direct effect of ADs on pancreatic β-cells is involved is unclear. We examined this idea for 3 ADs: paroxetine, clomipramine and, with particular emphasis, fluoxetine, on insulin secretion, mitochondrial function, cellular bioenergetics, KATP channel activity, and caspase activity in murine and human cell-line models of pancreatic β-cells. Metabolic assays showed that these ADs decreased the redox, oxidative respiration, and energetic potential of β-cells in a time and concentration dependent manner, even at a concentration of 100 nM, well within the therapeutic window. These effects were related to inhibition of mitochondrial complex I and III. Consistent with impaired mitochondrial function, lactate output was increased and insulin secretion decreased. Neither fluoxetine, antimycin nor rotenone could reactivate KATP channel activity blocked by glucose unlike the mitochondrial uncoupler, FCCP. Chronic, but not acute, AD increased oxidative stress and activated caspases, 3, 8, and 9. A close agreement was found for the rates of oxidative respiration, lactate output and modulation of KATP channel activity in MIN6 cells with those of primary murine cells; data that supports MIN6 as a valid model to study beta-cell bioenergetics. To conclude, paroxetine, clomipramine and fluoxetine were all cytotoxic at therapeutic concentrations on pancreatic beta-cells; an action suggested to arise by inhibition of mitochondrial bioenergetics, oxidative stress and induction of apoptosis. These actions help explain the diabetogenic potential of these ADs in humans

Use of artificial intelligence on electroencephalogram (EEG) waveforms to predict failure in early school grades in children from a rural cohort in Pakistan

Universal primary education is critical for individual academic growth and overall adult productivity of nations. Estimates indicate that 25% of 59 million primary age out of school children drop out and early grade failure is one of the factors. An objective and feasible screening measure to identify at-risk children in the early grades can help to design appropriate interventions. The objective of this study was to use a Machine Learning algorithm to evaluate the power of Electroencephalogram (EEG) data collected at age 4 in predicting academic achievement at age 8 among rural children in Pakistan. Demographic and EEG data from 96 children of a cohort along with their academic achievement in grade 1-2 measured using an academic achievement test of Math and language at the age of 7-8 years was used to develop the machine learning algorithm. K- Nearest Neighbor (KNN) classifier was used on different model combinations of EEG, sociodemographic and home environment variables. KNN model was evaluated using 5 Stratified Folds based on the sensitivity and specificity. In the current dataset, 55% and 74% failed in the mathematics and language test respectively. On testing data across each fold, the mean sensitivity and specificity was calculated. Sensitivity was similar when EEG variables were combined with sociodemographic, and home environment (Math = 58.7%, Language = 66.3%) variables but specificity improved (Math = 43.4% to 50.6% and Language = 32% to 60%). The model requires further validation for EEG to be used as a screening measure with adequate sensitivity and specificity to identify children in their preschool age who may be at high risk of failure in early grades