Innovative Grid-Connected Photovoltaic Systems Control Based on Complex-Vector-Filter

The research presented in this paper explains how the complex-vector-filter (CVF) method can help in minimizing the current harmonic of a grid-tied photovoltaic system. In fact, the harmonic-free positive sequence (HFPS) load current is used to produce referential sinusoidal currents. This control stabilizes the grid’s currents under unbalanced load currents, as well as mitigates undesirable harmonic load currents, while feeding clean active power to the grid. Thanks to the proposed controller, the performance, such as robustness, as well as the stability and dynamics of the CVF are more effective compared to the proportional-integral (PI) with phase-locked-loop (PLL) controller. Moreover, the CVF ensures robustness and stability during the synchronization between the photovoltaic (PV) generator and the utility grid system. The PI&PLL control presents higher active and reactive power fluctuations during synchronization. On the other hand, the CVF ensures the elimination of the reactive power fluctuations during synchronization. The performance of the proposed CVF is validated by simulation through MATLAB software. Under all conditions, the grid current, considering harmonics, is within the limits set by the IEEE-519 power quality standard, where a total harmonic distortion (THD) of 1.56% was achieved in the case of feeding a non-linear load

Análisis PLS-SEM del índice ECSI de satisfacción del consumidor de aceite de oliva ecológico versus convencional, en la zona de Lleida (España) y la zona de Sfax (Túnez)

Esta comunicación que forma parte de la investigación en una Tesis Doctoral, tiene por objetivo general analizar la satisfacción del consumidor de Aceite de Oliva Ecológico y Convencional de la zona de Lleida, en España, y de la zona de Sfax (Túnez). Se aplica el European Customer Satisfaction Index (ECSI). España es el país con más producción mundial de aceite de oliva, y Túnez ocupa la tercera posición después de Italia. El auge de la dieta mediterránea y su característica saludable influye sobre el aumento del cultivo del olivar y la producción de aceite. Sin embargo, la producción ecológica no aumenta en la misma medida, a pesar de su mejor imagen de calidad y de sostenibilidad productiva. Se aplica el ECSI y sus variables latentes pertinentes, que se estiman gracias a las variables medibles previstas y obtenidas a través de dos encuestas de más de 400 consumidores de la zona de Lleida (España) y otros 400 en la zona de Sfax (Túnez). Seguirá, la aplicación del modelo PLS-SEM, para cada tipo de aceite de oliva y para cada zona estudiada. Se podrá llegar a plantear explicaciones de dicha satisfacción a tener en cuenta en la planificación empresarial

Large photovoltaic power plants integration: A review of challenges and solutions

Renewable energy systems (RESs), such as photovoltaic (PV) systems, are providing increasingly larger shares of power generation. PV systems are the fastest growing generation technology today with almost ~30% increase since 2015 reaching 509.3 GWp worldwide capacity by the end of 2018 and predicted to reach 1000 GWp by 2022. Due to the fluctuating and intermittent nature of PV systems, their large-scale integration into the grid poses momentous challenges. This paper provides a review of the technical challenges, such as frequency disturbances and voltage limit violation, related to the stability issues due to the large-scale and intensive PV system penetration into the power network. Possible solutions that mitigate the effect of large-scale PV system integration on the grid are also reviewed. Finally, power system stability when faults occur are outlined as well as their respective achievable solutions

Análisis de componentes principales y clúster de los atributos del aceite de oliva ecológico versus convencional, en la zona de Lleida (España) y la zona de Sfax (Túnez)

Esta comunicación tiene como objeto resumir una investigación doctoral sobre la comparación entre el Aceite de Oliva Ecológico y Convencional consumido en la zona de Lleida, (España) y en la zona de Sfax (Túnez), estudiando y analizando atributos relevantes y la actitud del consumidor comparando el aceite de oliva ecológico y el convencional, y los resultados en las dos zonas estudiadas. España lidera la producción mundial de aceite de oliva, y Túnez ocupa la tercera posición después de Italia. El auge de la dieta mediterránea y su característica saludable influye sobre el aumento del cultivo del olivar y la producción de aceite. Sin embargo, la producción de aceite de oliva ecológico no aumenta en la misma medida, a pesar de su mejor imagen de calidad y de sostenibilidad productiva. La metodología planteada es el Análisis de Componentes Principales y el Análisis Clúster, sobre los resultados de una encuesta a una muestra de más de 400 consumidores en la zona de Lleida y a otro grupo de más de 400 consumidores de la zona de Sfax. Se llegará a detectar y analizar aspectos y elementos que influyen en la compra de uno u otro tipo de aceite en las zonas estudiadas

Determination of Physicochemical Water Quality of the Ghis-Nekor Aquifer (Al Hoceima, Morocco) Using Hydrochemistry, Multiple Isotopic Tracers, and the Geographical Information System (GIS)

The chemical characterization of the Ghis-Nekor groundwater has become a concern of many researchers in Morocco. It is a crucial indicator for the environment situation and the socioeconomic development of this Moroccan region. Indeed, it helps decisionmakers carry out conscious and sustainable management. For this reason, 20 samples of the Ghis-Nekor aquifer were examined in terms of physicochemical parameters such as pH, temperature, electrical conductivity (EC), and total alkalinity (Alk), major cations–anions (Ca2+, Mg2+, Na+, K+, HCO3−, Cl−, SO42−, NO3−, and TDS), isotopic elements (δ18O, δ2H, and δ13C), and concentrations of Br and Sr anions in 2020. Furthermore, spatial data analysis with a geographic information system (GIS) using the ArcGis software (Redlands, California, USA). Indeed, static maps show significant water quality information that helps characterize the groundwater of the study area. The spatial analysis by the GIS indicates that except the EC (from 2630 to 6950 mS/cm), all the physical parameters showed standard concentration values in most of the samples. A significant concentration above the Moroccan norm of groundwater quality for sodium (Na+) from 264.3 to 1500 mg/L, chlorides (Cl−) concentrations from 408.3 to 1510 mg/L, SO42− from 313.1 to 999.2 mg/L, and bicarbonate (HCO3−) from 283.7 to 679.8 mg/L was observed, while all the points exceeded the recommended standards norm for SO42−. Most of the points met the potability standards for potassium (K+). In terms of the isotopic elements, the concentration values of δ18O were from −3.92‰ to –5.60‰, while the δ2H concentration values varied between −28.67‰ and −39.99‰. The analysis revealed values of carbon isotope δ13C ranging between −3.15‰ and −8.61‰, thus suggesting that the origin of the carbon is mineral, mainly deriving from calcite dissolution. The analysis of the bromide and strontium contents made it possible to discriminate the origin of the salinity anomalies. The Cl/Br, Br/Cl, and Sr/Ca molar ratios distinguished the areas of influence of geological setting (saliferous facies outcrops) or anthropogenic effect (wastewater). The results of the analysis shed light on factors of contamination, which are as follows: urban zones (Imzourene, Ait Youssef, and Souani) and agricultural activities. Therefore, the use of these waters could pose a risk to the health of humans and animals. Similarly, the GIS is a practical and effective tool for the Ghis-Nekor groundwater quality diagnostics and could help decisionmakers establish solutions

Family specific genetic predisposition to breast cancer: results from Tunisian whole exome sequenced breast cancer cases.

International audienceBACKGROUND:A family history of breast cancer has long been thought to indicate the presence of inherited genetic events that predispose to this disease. In North Africa, many specific epidemio-genetic characteristics have been observed in breast cancer families when compared to Western populations. Despite these specificities, the majority of breast cancer genetics studies performed in North Africa remain restricted to the investigation of the BRCA1 and BRCA2 genes. Thus, comprehensive data at a whole exome or whole genome level from local patients are lacking.METHODS:A whole exome sequencing (WES) of seven breast cancer Tunisian families have been performed using a family-based approach. We focused our analysis on BC-TN-F001 family that included two affected members that have been sequenced using WES. Relevant variants identified in BC-TN-F001 have been confirmed using Sanger sequencing. Then, we conducted an integrative analysis by combining our results with those from other WES studies in order to figure out the genetic transmission model of the newly identified genes. Biological network construction and protein-protein interactions analyses have been performed to decipher the molecular mechanisms likely accounting for the role of these genes in breast cancer risk.RESULTS:Sequencing, filtering strategies, and validation analysis have been achieved. For BC-TN-F001, no deleterious mutations have been identified on known breast cancer genes. However, 373 heterozygous, exonic and rare variants have been identified on other candidate genes. After applying several filters, 12 relevant high-risk variants have been selected. Our results showed that these variants seem to be inherited in a family specific model. This hypothesis has been confirmed following a thorough analysis of the reported WES studies. Enriched biological process and protein-protein interaction networks resulted in the identification of four novel breast cancer candidate genes namely MMS19, DNAH3, POLK and KATB6.CONCLUSIONS:In this first WES application on Tunisian breast cancer patients, we highlighted the impact of next generation sequencing technologies in the identification of novel breast cancer candidate genes which may bring new insights into the biological mechanisms of breast carcinogenesis. Our findings showed that the breast cancer predisposition in non-BRCA families may be ethnic and/or family specific

Family specific genetic predisposition to breast cancer: results from Tunisian whole exome sequenced breast cancer cases

Abstract Background A family history of breast cancer has long been thought to indicate the presence of inherited genetic events that predispose to this disease. In North Africa, many specific epidemio-genetic characteristics have been observed in breast cancer families when compared to Western populations. Despite these specificities, the majority of breast cancer genetics studies performed in North Africa remain restricted to the investigation of the BRCA1 and BRCA2 genes. Thus, comprehensive data at a whole exome or whole genome level from local patients are lacking. Methods A whole exome sequencing (WES) of seven breast cancer Tunisian families have been performed using a family-based approach. We focused our analysis on BC-TN-F001 family that included two affected members that have been sequenced using WES. Relevant variants identified in BC-TN-F001 have been confirmed using Sanger sequencing. Then, we conducted an integrative analysis by combining our results with those from other WES studies in order to figure out the genetic transmission model of the newly identified genes. Biological network construction and protein–protein interactions analyses have been performed to decipher the molecular mechanisms likely accounting for the role of these genes in breast cancer risk. Results Sequencing, filtering strategies, and validation analysis have been achieved. For BC-TN-F001, no deleterious mutations have been identified on known breast cancer genes. However, 373 heterozygous, exonic and rare variants have been identified on other candidate genes. After applying several filters, 12 relevant high-risk variants have been selected. Our results showed that these variants seem to be inherited in a family specific model. This hypothesis has been confirmed following a thorough analysis of the reported WES studies. Enriched biological process and protein–protein interaction networks resulted in the identification of four novel breast cancer candidate genes namely MMS19, DNAH3, POLK and KATB6. Conclusions In this first WES application on Tunisian breast cancer patients, we highlighted the impact of next generation sequencing technologies in the identification of novel breast cancer candidate genes which may bring new insights into the biological mechanisms of breast carcinogenesis. Our findings showed that the breast cancer predisposition in non-BRCA families may be ethnic and/or family specific

Contamination of planktonic food webs in the Mediterranean Sea: Setting the frame for the MERITE-HIPPOCAMPE oceanographic cruise (spring 2019)

International audienceThis paper looks at experiential feedback and the technical and scientific challenges tied to the MERITE-HIPPOCAMPE cruise that took place in the Mediterranean Sea in spring 2019. This cruise proposes an innovative approach to investigate the accumulation and transfer of inorganic and organic contaminants within the planktonic food webs. We present detailed information on how the cruise worked, including 1) the cruise track and sampling stations, 2) the overall strategy, based mainly on the collection of plankton, suspended particles and water at the deep chlorophyll maximum, and the separation of these particles and planktonic organisms into various size fractions, as well as the collection of atmospheric deposition, 3) the operations performed and material used at each station, and 4) the sequence of operations and main parameters analysed. The paper also provides the main environmental conditions that were prevailing during the campaign. Lastly, we present the types of articles produced based on work completed by the cruise that are part of this special issue