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This manuscript presents current sensorless algorithms for maximum power point tracking (MPPT) in partially shaded photovoltaic (PV) systems. The necessity of a current sensor is eliminated with the use of mathematical modeling of the power electronics converter. This approach significantly reduces the implementation cost and the inherent disadvantages in the current sensor circuitry. MPPT techniques based on soft computing are employed, in addition to Perturb and Observe (P&O), due to their ability to explore a larger search space. This feature is advantageous because it minimizes convergence risk to a local maximum, a limitation of traditional techniques. Simulation and experimental results are presented and each algorithm is evaluated through different metrics, such as search time for the global maximum power point (GMPP) and efficiency. The tests consider dynamic irradiance profiles, producing a tracking factor (TF) above 99% and a remarkable fast convergence time.

Summary: Background: Although immunomodulators have established benefit against the new coronavirus disease (COVID-19) in general, it is uncertain whether such agents improve outcomes without increasing the risk of secondary infections in the specific subgroup of previously immunocompromised patients. We assessed the effect of immunomodulators on outcomes of immunocompromised patients hospitalized for COVID-19. Methods: The protocol was prospectively registered with PROSPERO (CRD42022335397). MEDLINE, Cochrane Central Register of Controlled Trials and references of relevant articles were searched up to 01-06-2022. Authors of potentially eligible randomized controlled trials were contacted to provide data on immunocompromised patients randomized to immunomodulators vs control (i.e., placebo or standard-of-care). Findings: Eleven randomized controlled trials involving 397 immunocompromised patients hospitalized for COVID-19 were included. Ten trials had low risk of bias. There was no difference between immunocompromised patients randomized to immunomodulators vs control regarding mortality [30/182 (16.5%) vs 41/215 (19.1%); RR 0.93, 95% CI 0.61–1.41; p = 0.74], secondary infections (RR 1.00, 95% CI 0.64–1.58; p = 0.99) and change in World Health Organization ordinal scale from baseline to day 15 (weighed mean difference 0.27, 95% CI -0.09–0.63; p = 0.15). In subgroup analyses including only patients with hematologic malignancy, only trials with low risk of bias, only trials administering IL-6 inhibitors, or only trials administering immunosuppressants, there was no difference between comparators regarding mortality. Interpretation: Immunomodulators, compared to control, were not associated with harmful or beneficial outcomes, including mortality, secondary infections, and change in ordinal scale, when administered to immunocompromised patients hospitalized for COVID-19. Funding: Hellenic Foundation for Research and Innovation.

An efficient genetic transformation protocol is necessary to edit genes for trait improvement directly in elite bread wheat cultivars. We used a protein fusion between a wheat growth-regulating factor 4 (GRF4) and its interacting factor (GIF1) to develop a reproducible genetic transformation and regeneration protocol, which we then used to successfully transform elite bread wheat cultivars Baj, Kachu, Morocco, Reedling, RL6077, and Sujata in addition to the experimental cultivar Fielder. Immature embryos were transformed with the vector using particle bombardment method. Transformation frequency increased nearly 60-fold with the GRF4-GIF1-containing vectors as compared to the control vector and ranged from ~5% in the cultivar Kachu to 13% in the cultivar RL6077. We then edited two genes that confer resistance against leaf rust and powdery mildew directly in the aforementioned elite cultivars. A wheat promoter, TaU3 or TaU6, to drive the expression of guide RNA was effective in gene editing whereas the OsU3 promoter failed to generate any edits. Editing efficiency was nearly perfect with the wheat promoters. Our protocol has made it possible to edit genes directly in elite wheat cultivars and would be useful for gene editing in other wheat varieties, which have been recalcitrant to transformation thus far.

Implantable medical devices (IMDs) necessitate a consistent energy supply, commonly sourced from an embedded battery. However, given the finite lifespan of batteries, periodic replacement becomes imperative. This paper addresses the challenge by introducing a wireless power transfer system designed specifically for implantable medical devices (IMDs). It begins with a detailed analysis of the four conventional topologies. Following this, the paper provides a thorough explanation for choosing the PS topology, highlighting its advantages and suitability for the intended application. The primary parallel capacitance necessitates power from current sources; thus, a Class-E amplifier was implemented. Additionally, the selected circuit was engineered to deliver 1 W at the biocompatible resonance frequency of 13.56 MHz. The delineation of the resonance parameters hinges on multifaceted solutions, encompassing bifurcation-free operation and the attainment of peak efficiency. To ensure the feasibility of the proposed solution, a Differential-Evolution-based algorithm was employed. The results obtained from simulation-based evaluations indicated that the system achieved an efficiency exceeding 86%. This efficiency level was maintained even in the face of frequency fluctuations and variations in the coupling between the coils, thereby ensuring stable operational performance. This aligns seamlessly with the specified application prerequisites, guaranteeing a feasible and reliable operation.

The work consists of the development of a market-friendly 600 W photovoltaic battery-less water pumping system. The system is composed of four 280 Wp solar panels, an auxiliary 10 W solar panel, a three-phase converter and a ½ horsepower (hp) submersible water pump. The electronic stage involves a resonant DC-DC converter in series with a voltage source three-phase inverter. The novelties of this work are related to the use of a resonant DC-DC converter with fixed duty-cycle and frequency for water pumping application, the use of Silicon Carbide Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) for solving converter startup issues, and the use of a constant voltage maximum power tracking (MPPT) algorithm with auxiliary panels. The work displays the design of the converter, simulation and experimental results, discussions, and cost evaluation. The feasibility of the system is studied for the water requirements of a beef cattle farm in Brazil.

This paper presents novel current sensorless maximum-power point-tracking (MPPT) algorithms based on compensators/controllers and a single-input voltage sensor. The proposed MPPTs eliminate the expensive and noisy current sensor, which can significantly reduce the system cost and retain the advantages of the widely used MPPT algorithms, such as Incremental Conductance (IC) and Perturb and Observe (P&O) algorithms. Additionally, it is verified that the proposed algorithms, especially the proposed Current Sensorless V based on PI, can reach outstanding tracking factors (TFs) such as the IC and P&O based on PI algorithms. In this sense, the insertion of controllers inside the MPPT gives them adaptive characteristics, and the experimental TFs are in the remarkable range of more than 99%, with an average yield of 99.51% and a peak of 99.80%.

This work proposes a differential evolution algorithm to control a vehicle-to-grid (V2G) system based on photovoltaic generation and energy cost curves, and constraints associated with the power converters’ operation, battery charging strategy, and initial budgets. The algorithm is designed to trade off the batteries’ state of charge and the profits gained from selling energy to the grid. To achieve this balance, a fuzzy controller is employed and acts based on forecasts of the photovoltaic generation and the cost of electricity, within prediction windows of 120 min, adapting the batteries’ rate of charging or discharging. Simulation results show that for different curves and different initial budgets, the target state of charge is reached at the end of the time horizon. By evaluating the proposed scheme under different scenarios, the algorithm’s performance is proven to be suitable for future practical deployment.

This paper describes the use of a Cascaded H-Bridge Multilevel Inverter to deal with the problem of partial shading in a photovoltaic system connected to the grid. Combined with the topology, it proposes the use of a virtual synchronous generator for power sharing between photovoltaic arrays and to ensure the connection to the power grid even in extreme shading situations with no power buffer. The experimental results demonstrate the feasibility of the strategy adopted and the limitations to overcome.

This work compares the performance of two embedded FPGA controllers that can be used in Active Parallel Power Filters (APPF). Both controllers are validated through the FPGA-in-the-loop (FIL) technique, the algorithm’s synthesis is accomplished using the Quartus II® platform, and the board used is from Altera®—Cyclone IV DE2-115. The main difference between the controllers resides in the power theories used to obtain the currents for compensation. The results confirm that the FPGA is a suitable digital device for the parallel operation of multiple compensators and calculation stages, being a viable solution for the requirements imposed in the control of APPF. Furthermore, the effectiveness of the FIL technique for validating the operation of digital circuits and control systems is also confirmed. Finally, a comparison between the processing costs of each of the implemented power theories is presented to guide novel proposals.

This article presents a study of the sampling rate effect on electrical power measurements whose definitions are based on the Conservative Power Theory (CPT). The definitions of active power and reactive power of the CPT were applied in the MATLAB® software by varying the sampling rate and using a digital power meter as a reference. The measurements were performed in scenarios with linear and non-linear loads. Due to the usage of an integral in the CPT calculus, an error was verified associated with the reactive power being inversely proportional to the sampling rate. From the present study, it is possible to conclude that depending on the sample rate, the errors associated with the reactive power measurements are unacceptable and make the CPT implementation unfeasible. The results also presented effective information about the minimal sampling rate needed to make these errors neglected and to assist in choosing suitable microprocessors for the digital implementation of the CPT. It is worth mentioning that this paper was limited to assess how accurate the measurements of active and reactive powers were and important to highlight that the CPT has the additional contribution of dealing with distortion currents and consequently new portions of powers. For the latter, the influence of sampling rate may be crucial and new lines of investigation are motivated.

Este artigo apresenta um inversor monofásico de 4,8kW para aplicações fotovoltaicas, baseado nos conversores Boost ZVT e inversor H6, para a conexão à rede de distribuição. Devido aos valores nominais de corrente o conversor Boost ZVT traz vantagens, considerando-se reduzida interferência eletromagnética, além de elevada eficiência (acima de 96%), enquanto que o inversor H6 permite o projeto de elementos de conexão com indutância reduzida, além de propiciar baixa variação de nível de tensão de modo comum. No presente artigo, um sistema de MPPT híbrido que pode atuar dependendo do nível da tensão de entrada da associação de painéis é apresentado, podendo o sistema operar com todos os conversores ou apenas com o conversor CC-CA, fato que eleva a eficiência do sistema. Finalmente, resultados e análises são apresentadas, contendo todos os algoritmos necessários à aplicação proposta.

Vascular calcification is associated with poor cardiovascular outcome. Histochemical analysis of calcification and the expression of proteins involved in mineralization are usually based on whole section analysis, thereby often ignoring regional differences in atherosclerotic lesions. At present, limited information is available about factors involved in the initiation and progression of atherosclerosis.This study investigates the intra-section association of micro-calcifications with markers for atherosclerosis in randomly chosen section areas of human coronary arteries. Moreover, the possible causal relationship between calcifying vascular smooth muscle cells and inflammation was explored in vitro.To gain insights into the pathogenesis of atherosclerosis, we performed analysis of the distribution of micro-calcifications using a 3-MeV proton microbeam. Additionally, we performed systematic analyses of 30 to 40 regions of 12 coronary sections obtained from 6 patients including histology and immuno-histochemistry. Section areas were classified according to CD68 positivity. In vitro experiments using human vascular smooth muscle cells (hVSMCs) were performed to evaluate causal relationships between calcification and inflammation.From each section multiple areas were randomly chosen and subsequently analyzed. Depositions of calcium crystals at the micrometer scale were already observed in areas with early pre-atheroma type I lesions. Micro-calcifications were initiated at the elastica interna concomitantly with upregulation of the uncarboxylated form of matrix Gla-protein (ucMGP). Both the amount of calcium crystals and ucMGP staining increased from type I to IV atherosclerotic lesions. Osteochondrogenic markers BMP-2 and osteocalcin were only significantly increased in type IV atheroma lesions, and at this stage correlated with the degree of calcification. From atheroma area type III onwards a considerable number of CD68 positive cells were observed in combination with calcification, suggesting a pro-inflammatory effect of micro-calcifications. In vitro, invasion assays revealed chemoattractant properties of cell-culture medium of calcifying vascular smooth muscle cells towards THP-1 cells, which implies pro-inflammatory effect of calcium deposits. Additionally, calcifying hVSMCs revealed a pro-inflammatory profile as compared to non-calcifying hVSMCs.Our data indicate that calcification of VSMCs is one of the earliest events in the genesis of atherosclerosis, which strongly correlates with ucMGP staining. Our findings suggest that loss of calcification inhibitors and/or failure of inhibitory capacity is causative for the early precipitation of calcium, with concomitant increased inflammation followed by osteochondrogenic transdifferentiation of VSMCs.

Este trabalho propõe um sistema de medição e uma metodologia de modelação para a avaliação de erros de medição em medidores de energia elétrica ativa do tipo indução e eletrônico. O sistema de medição propicia condições distintas de distorções harmônicas para tensões e correntes nos testes experimentais, além de permitir o emprego de formas de onda de tensões equilibradas ou desequilibradas (3% e 5%). As formas de onda empregadas nos testes experimentais são provenientes de um banco de dados composto por medições em consumidores com diferentes características de carga (industrial, comercial, rural e residencial). A metodologia para modelação dos erros de medição é baseada na utilização de dados experimentais provenientes do sistema de medição proposto, evitando as incertezas de modelação relacionadas com a idealização e não modelação de parâmetros comportamentais, especialmente quando o modelo de erro de medição é determinado de maneira totalmente teórica, e consideradas condições não senoidais. Com o objetivo de demonstrar a metodologia de avaliação proposta, o sistema de medição é descrito e são apresentados alguns resultados de modelação dos efeitos das distorções harmônicas e desequilíbrios de tensões sobre medidores watt-hora eletromecânicos do tipo indução e eletrônicos, bifásicos e trifásicos.

O objetivo deste trabalho é apresentar uma topologia de um inversor push-pull de três níveis, denominado push-pull modificado. Algumas topologias com o mesmo objetivo já foram propostas [2-3], mas, em geral, não apresentam vantagens em relação a um inversor de ponte completa. A simplicidade é a principal vantagem dos conversores push-pull, o que os torna atrativos para aplicações de baixa potência. O inversor proposto é obtido adicionando-se apenas uma chave ao push-pull padrão. Esta nova topologia permite controle completo de três níveis, utilizando menor quantidade de chaves comparado a um inversor de ponte completa. Primeiramente, a topologia do inversor será apresentada e, então, os passos de operação serão descritos, mostrando os princípios de operação e as leis de controle. Uma comparação entre quatro topologias de inversores também é apresentada. Finalmente, simulações e resultados experimentais são mostrados para a validação da topologia. Esse novo inversor é viável para aplicações com baixas tensões de entrada e que demandam modulação de três níveis, como em sistemas de geração distribuída baseada em energia renovável.

Afirmar que vivimos en una sociedad de consumo no es un simple eufemismo sino una realidad que sentimos y vivimos en cada situación en la que nos vemos involucrados. Ello se debe a que ha finalizado la época del autoabastecimiento y en un mundo cada vez más complejo y diversificado la interdependencia es un elemento indispensable para que el factor económico tenga pujanza. El consumismo puede desenvolverse dentro de la sociedad de cada Estado; es notable ver cómo las relaciones de consumo han sido el ámbito preferido de regulación en el continente latinoamericano, generalmente dotadas de normas de policía o de aplicación inmediata. Consumo y arbitraje han sido los temas seleccionados por el legislador nacional a la hora de actualizar sus ordenamientos jurídicos. (...) Contenido: Antecedentes. El Protocolo de Santa María. Ambito material. La competencia.

Al modelo de Estado del siglo XVIII que asumía como únicas funciones la de juez para la solución de los litigios entre los particulares y de gendarme con el objetivo de preservar lapaz pública, le sucedió en los primeros 50 años de nuestro siglo la concepción de un Estado intervencionista -denominado también welfare state o Estado Bienestar- en el que se le otorgó una mayor atención al bienestar de sus habitantes mediante una gestión directa de numerosos sectores de la economía, al privilegio en el desarrollo de aquellas áreas más deprimidas, a la distribución intencional de los recursos sociales en favor de los desprotegidos económicamente, etc (...) Contenido: La doctrina. El derecho positivo. La doctrina uruguaya. 1985-1995. La posición de Uruguay respecto de la liberalización del comercio internacional. La Ronda Uruguay del GATT y la Organización Mundial del Comercio. Conclusiones

El grupo de países europeos que se encuentra comprometido en el proceso de integración económica formuló hace ya tiempo, los criterios para determinar las bases de competencia a fi~ de resolver los litigios de derecho privado que pudieran surgir en dicho espacio geográfico. El documento elaborado fue el Convenio de Bruselas sobre competencia judicial y ejecución de las resoluciones en materia civil y mercantil del 27 de setiembre de 1968. Sin embargo, en dicho momento no fue posible regular las bases de competencia en los procedimientos civiles que se vinculaban conlos temas del divorcio, de la separación legal de los cónyuges y acerca de las cuestiones relacionadas conla nulidad del matrimonio (...) Contenido: Ambito de aplicación. Bases de competencia directa. Verificación de la competenciay verificación de la admisibilidad. Litispendentia y acciones conexas. Reconocimiento y ejecución. Definiciones. Ejecución.Procedimiento de la ejecución. Ejecución parcial. Cláusulas de compatibilidad interconvencionales. Tribunal de Justicia de las Comunidades Europeas. Una visión general del Convenio

Contenido: Introducción. El Estado como instrumento de la racionalidad jurídica. Primer contragolpe en favor de la restauración de los valores irreflexivos: Savigny. La racionalidad jurídica al servicio del Estado: el neo-territorialismo rioplatense. Segundo contragolpe contra el racionalismo formal: el materialismo de Quintín Alfonsín. El reconocimiento de otras formas de racionalidad descartan al Estado como el único intérprete. ¿Y el futuro?