Conservation Agriculture(CA)covers more than 205 million hectares in the world.This made it possible to face and mitigate the challenges of climate change,reducing soil erosion and providing multiple ecosystem service...Conservation Agriculture(CA)covers more than 205 million hectares in the world.This made it possible to face and mitigate the challenges of climate change,reducing soil erosion and providing multiple ecosystem services.The first elementary factor influenced is the yield evaluation.It has a direct effect on farmers’choices for sustainable production.The present article records a review focused on wheat yield average positive change compared between conventional tillage(CT)and no tillage(NT)systems.The international database collected showed that NT is adaptable everywhere.The results of wheat yield differentiation showed the influence of crop rotation depending on stations located in different climatic zones.In more than 40 years of research,specialists have succeeded in demonstrating the importance of crop productivity like wheat.The whole integrates also experimentations where the initiation starts more than ten years.展开更多
Objective:To investigate the relationship between triterpenoid saponin content and antioxidant,antimicrobial,and α-glucosidase inhibitory activities of 70%ethanolic,butanolic,aqueous,supernate and precipitate extract...Objective:To investigate the relationship between triterpenoid saponin content and antioxidant,antimicrobial,and α-glucosidase inhibitory activities of 70%ethanolic,butanolic,aqueous,supernate and precipitate extracts of Juglans regia leaves.Methods:Triterpenoid saponins of different Juglans regia leaf extracts were measured by the vanillin method.Antioxidant activity was evaluated against DPPH and ABTS free radicals.We also assessed α-glucosidase inhibitory and antimicrobial activities of the leaf extracts.Pearson’s correlation coefficient was evaluated to determine the correlation between the saponin content and biological activities.Results:The butanolic extract was most effective against DPPH with an IC50of 6.63μg/mL,while the aqueous extract showed the highest scavenging activity against ABTS free radical with an IC50of 42.27μg/mL.Pearson’s correlation analysis indicated a strong negative correlation (r=-0.956) between DPPH radical scavenging activity (IC50) and the saponin content in the samples examined.In addition,the aqueous extract showed the best α-glucosidase inhibitory activity compared with other extracts.All the extracts had fair antibacterial activity against Bacillus subtilis,Escherichia coli,and Klebsiella pneumoniae except for the aqueous extract.Conclusions:Juglans regia extracts show potent antioxidant,antimicrobial,and α-glucosidase inhibitory activities.There is a correlation between saponin levels in Juglans regia leaf extracts and the studied activities.However,additional research is required to establish these relationships by identifying the specific saponin molecules responsible for these activities and elucidating their mechanisms of action.展开更多
Quantum correlations that surpass entanglement are of great importance in the realms of quantum information processing and quantum computation.Essentially,for quantum systems prepared in pure states,it is difficult to...Quantum correlations that surpass entanglement are of great importance in the realms of quantum information processing and quantum computation.Essentially,for quantum systems prepared in pure states,it is difficult to differentiate between quantum entanglement and quantum correlation.Nonetheless,this indistinguishability is no longer holds for mixed states.To contribute to a better understanding of this differentiation,we have explored a simple model for both generating and measuring these quantum correlations.Our study concerns two macroscopic mechanical resonators placed in separate Fabry–Pérot cavities,coupled through the photon hopping process.this system offers a comprehensively way to investigate and quantify quantum correlations beyond entanglement between these mechanical modes.The key ingredient in analyzing quantum correlation in this system is the global covariance matrix.It forms the basis for computing two essential metrics:the logarithmic negativity(E_(N)^(m))and the Gaussian interferometric power(P_(G)^(m)).These metrics provide the tools to measure the degree of quantum entanglement and quantum correlations,respectively.Our study reveals that the Gaussian interferometric power(P_(G)^(m))proves to be a more suitable metric for characterizing quantum correlations among the mechanical modes in an optomechanical quantum system,particularly in scenarios featuring resilient photon hopping.展开更多
The Tarfaya-Laayoune-Boujdour basin is of great interest to oil exploration;on this aspect, there has been exploration by the Moroccan National Office of Hydrocarbons and Mining, which has shown indices of oil and/or ...The Tarfaya-Laayoune-Boujdour basin is of great interest to oil exploration;on this aspect, there has been exploration by the Moroccan National Office of Hydrocarbons and Mining, which has shown indices of oil and/or gas recorded in most wells drilled in the Moroccan Atlantic margin. FD-1 well, object of this study, is one of these wells located in the offshore Tarfaya-Laayoune-Boujdour basin. A palynological examination of the processed samples revealed the existence of organic palynomorphs, well conserved and rich in dinoflagellate cysts. The latter are composed of worldwide marker taxa of high stratigraphic resolutions. Thus, the middle upper Albian (3408 - 3408.5 m) is determined by the presence of Cribroperidinium tensiftense, Tehamadinium coummia, Spiniferella cornuta, Chichaouadinium vestitum, Dinopterygium alatum and Litosphaeridium arundum. The upper Albian (3406.5 - 3408 m) is characterized by the FOs of marker taxa: Cyclonephelium chabaca, Cribroperidinium auctificum and Chichaouadinium vestitum. Lastly, the upper Albian-lower Cenomanian transition is defined between 3404 m and 3406.50 m, as suggested by the FOs of Chichaouadinium boydii, Dinopterygium tuberculatum, Sepispinula ancorifera, Litosphaeridium conispinum, Prolixosphaeridium conulum and Xenascus ceratioides.展开更多
Mixed cation and anion based perovskites solar cells exhibited enhanced stability under outdoor conditions,however,it yielded limited power conversion efficiency when TiO_(2) and Spiro-OMeTAD were employed as electron...Mixed cation and anion based perovskites solar cells exhibited enhanced stability under outdoor conditions,however,it yielded limited power conversion efficiency when TiO_(2) and Spiro-OMeTAD were employed as electron and hole transport layer(ETL/HTL)respectively.The inevitable interfacial recombination of charge carriers at ETL/perovskite and perovskite/HTL interface diminished the efficiency in planar(n-i-p)perovskite solar cells.By employing computational approach for uni-dimensional device simulator,the effect of band offset on charge recombination at both interfaces was investigated.We noted that it acquired cliff structure when the conduction band minimum of the ETL was lower than that of the perovskite,and thus maximized interfacial recombination.However,if the conduction band minimum of ETL is higher than perovskite,a spike structure is formed,which improve the performance of solar cell.An optimum value of conduction band offset allows to reach performance of 25.21%,with an open circuit voltage(VOC)of 1231 mV,a current density JSC of 24.57 mA/cm^(2) and a fill factor of 83.28%.Additionally,we found that beyond the optimum offset value,large spike structure could decrease the performance.With an optimized energy level of Spiro-OMeTAD and the thickness of mixed-perovskite layer performance of 26.56% can be attained.Our results demonstrate a detailed understanding about the energy level tuning between the charge selective layers and perovskite and how the improvement in PV performance can be achieved by adjusting the energy level offset.展开更多
This work is devoted to the study of the inhibition of corrosion of mild steel(MS)in molar hydrochloric acid(1 mol·L-1 HCl)by two named quinoxaline derivatives namely,2-(2,4-dichlorophenyl)-1,4-dihydroquinoxaline...This work is devoted to the study of the inhibition of corrosion of mild steel(MS)in molar hydrochloric acid(1 mol·L-1 HCl)by two named quinoxaline derivatives namely,2-(2,4-dichlorophenyl)-1,4-dihydroquinoxaline(HQ)and 2-(2,4-dichlorophenyl)-6-methyl-1,4-dihydroquinoxaline(CQ).The inhibitory efficacy of HQ and CQ compounds is first evaluated using the gravimetric method and using electrochemical techniques(stationary and transient techniques).The results showed that our compounds are efficient corrosion inhibitors and the inhibition rates(ηEIS%)reached up to 91%and 94.2%at 10-3 mol·L-1 for HQ and CQ,respectively.The mentioned molecules are classified as mixed-type inhibitors.The adsorption of these inhibitors on the surface of steel in hydrochloric HCl 1 mol·L-1 medium obeys the Langmuir adsorption isotherm.The results of the scanning electron microscope(SEM)showed the formation of a protective film on the surface of the steel in the presence of the inhibitors studied.Elementary analysis is obtained by energy dispersive X-ray spectroscopy(EDS).The inhibition property was further elucidated by theoretical approaches such as:Density Functional Theory(DFT),quantum chemical descriptors(QCD),local reactive indices,solvent effect,theoretical complexation,Molecular Dynamic(MD)simulation,effect of temperature on adsorption energy(Eads),Radial Distribution Function(RDF),and Mean Square Displacement(MSD).The results of these approaches support the experimental results.展开更多
Magnetic hysteresis and compensation behavior of a mixed spin-(1, 3/2) Ising model on a square lattice are investigated in the framework of effective field theory based on a probability distribution technique. The e...Magnetic hysteresis and compensation behavior of a mixed spin-(1, 3/2) Ising model on a square lattice are investigated in the framework of effective field theory based on a probability distribution technique. The effect of random crystal field, ferromagnetic and ferrimagnetic exchange interaction on hysteresis loops and compensation phenomenon are discussed. A number of characteristic phenomena have been reported such as the observation of triple hysteresis loops at low temperatures and for negative values of random crystal field. Critical and double compensation temperatures have been also found. The obtained results are also compared to some previous works.展开更多
In this article we propose to combine an integrated method, the PCA-GMM method that generates a relatively improved segmentation outcome as compared to conventional GMM with Kalman Filtering (KF). The combined new met...In this article we propose to combine an integrated method, the PCA-GMM method that generates a relatively improved segmentation outcome as compared to conventional GMM with Kalman Filtering (KF). The combined new method the PCA-GMM-KF attempts tracking multiple moving objects;the size and position of the objects along the sequence of their images in dynamic scenes. The obtained experimental results successfully illustrate the tracking of multiple moving objects based on this robust展开更多
We report carbon stock in biomass, litter and soil estimated for six locations in natural Quercus ilex L. stands of the Middle and High Moroccan Atlas. Twenty trees at each location were selected according to their di...We report carbon stock in biomass, litter and soil estimated for six locations in natural Quercus ilex L. stands of the Middle and High Moroccan Atlas. Twenty trees at each location were selected according to their diameter classes and felled to measure the biomass of trunk, branches, twigs and leaves and determine allometric relationships. Soil was sampled in five depths (0 - 15, 15 - 30, 30 - 50, 50 - 70 and 70 - 100 cm) and litterfall production measured in all tree stands. The total carbon stock in above-ground biomass ranged between 17 Mg·haǃ in Aït Aamar stand (High Atlas) and 91 Mg·haǃ in Ksiba stand (Middle Atlas). Perennial organs (trunk, branches and twigs) stored over 95% of the tree carbon stock. Soil organic carbon concentrations ranged from 0.01% (in 70 - 100 cm in all stands) to 8.1% (in 0 - 15 cm in the Ajdir stand in Middle Atlas). The total organic carbon stock in the soil ranged between 141.4 t·haǃ in Ajdir and 24.6 t·haǃ in Asloul. The litter contained 0.2 Mg C haǃ in the clearing (C2) stand of High Atlas and 14.3 Mg C haǃ in (Ajdir) of carbon. The best fitted model for predicting carbon stock in tree biomass was obtained by applying the allometric equation Y = aXb for each biomass fraction and stand, where Y is the aboveground biomass (dry weight) and X is the DBH (Mean diameter at breast height, 1.30 m). These previous data obtained in the present study confirm the important function of these natural forests as longterm C sinks, in forest biomass, litter and soil. The potential long term C storage of these systems is moderately high, especially in less-intensively managed forests that include large trees. The established relationship between DBH and carbon stock in different tree organs can be used for forest carbon accounting, and also synthesize available information on oak forest as a sink for atmospheric CO2, and identify the management options that may enhance the capacity for C capture/ storage in forest soils.展开更多
The phytoavailability of lead and chromium in cherry tomatoes Lycopersicon esculentum was studied both at the level of different parts of the plant (roots, stem, leaves and fruits) and at the level of its concentratio...The phytoavailability of lead and chromium in cherry tomatoes Lycopersicon esculentum was studied both at the level of different parts of the plant (roots, stem, leaves and fruits) and at the level of its concentration in water and cultivation soil of. Two experiments are thence carried out by planting in bioponics, in a patented BIOTOP device, plants which are exposed via their root system to concentrations of 5 ppm, 10 ppm and 20 ppm of each contaminant (lead or chromium) in a nutrient solution. The results show that lead accumulates mainly in the roots with a significant amount as to allow its translocation into the stem and leaves, while only a small amount reaches the fruit. The results also show that when the concentration increases the lead content in the roots also increases, but decreases in the fruits with three floral bouquets. Conversely, the chromium substance decreases in the roots and increases in the fruit. Based on these results, we note that the average distribution of lead in the edible part of the plant is much higher than that of chromium, and also lead presence in the plant is higher compared to that of chromium.展开更多
The Democratic Republic of the Congo holds important reserves of oil shale which is still under geological status.Herein,the characterization and pyrolysis kinetics of typeⅠkerogen-rich oil shale of the western Centr...The Democratic Republic of the Congo holds important reserves of oil shale which is still under geological status.Herein,the characterization and pyrolysis kinetics of typeⅠkerogen-rich oil shale of the western Central Kongo(CK)were investigated.X-ray diffraction,Fourier-transform infrared spectroscopy and thermal analysis(TG/DTA)showed that CK oil shale exhibits a siliceous mineral matrix with a consistent organic matter rich in aliphatic chains.The pyrolysis behavior of kerogen revealed the presence of a single mass loss between 300 and 550°C,estimated at 12.5%and attributed to the oil production stage.Non-isothermal kinetics was performed by determining the activation energy using the iterative isoconversional model-free methods and exhibits a constant value with E=211.5±4.7 kJ mol.1.The most probable kinetic model describing the kerogen pyrolysis mechanism was obtained using the Coats–Redfern and Arrhenius plot methods.The results showed a unique kinetic triplet confirming the nature of kerogen,predominantly typeⅠand reinforcing the previously reported geochemical characteristics of the CK oil shale.Besides,the calculation of thermodynamic parameters(ΔH~*,ΔS~*andΔG~*)corresponding to the pyrolysis of typeⅠkerogen revealed that the process is non-spontaneous,in agreement with DTA experiments.展开更多
We investigate the generation of quantum correlations between mechanical modes and optical modes in an optomechanical system,using the rotating wave approximation.The system is composed of two Fabry-Pérot cavitie...We investigate the generation of quantum correlations between mechanical modes and optical modes in an optomechanical system,using the rotating wave approximation.The system is composed of two Fabry-Pérot cavities separated in space;each of the two cavities has a movable end-mirror.Our aim is the evaluation of entanglement between mechanical modes and optical modes,generated by correlations transfer from the squeezed light to the system,using Gaussian intrinsic entanglement as a witness of entanglement in continuous variables Gaussian states,and the quantification of the degree of mixedness of the Gaussian states using the purity.Then,we quantify nonclassical correlations between mechanical modes and optical modes even beyond entanglement by considering Gaussian geometric discord via the Hellinger distance.Indeed,entanglement,mixdness,and quantum discord are analyzed as a function of the parameters characterizing the system(thermal bath temperature,squeezing parameter,and optomechanical cooperativity).We find that,under thermal effect,when entanglement vanishes,purity and quantum discord remain nonzero.Remarkably,the Gaussian Hellinger discord is more robust than entanglement.The effects of the other parameters are discussed in detail.展开更多
Our calculations are based on the modeling technique and simulation Ab-Initio that appeals to the Density Functional Theory (DFT) relying on the Full-Potential Linearized Augmented Plane Waves (FP-LAPW) method that re...Our calculations are based on the modeling technique and simulation Ab-Initio that appeals to the Density Functional Theory (DFT) relying on the Full-Potential Linearized Augmented Plane Waves (FP-LAPW) method that requires a calculation process using approximations such as Local Density (LDA) and Generalized Gradient (GGA) developed in the modelling software of nanostructures WIEN2k. The optimal structure of the binary semiconductor ZnSe crystallizing in the complex phase of Zinc Blende (B3) was determined by studying the variation of energy depending on the volume of the elementary cell. Then the electronic properties of the optimized state were analyzed such as the gap energy, the total density of states (TDOS), the partial density of states (PDOS) and the repartition of the electronic charge density. The obtained results were successful compared with other theoretical and experimental values reported in literature.展开更多
The use of cold thermal storage systems in low-temperature industrial applications is considered one of the most promising ways of improving energy efficiency and reducing the use of power during peak periods.In this ...The use of cold thermal storage systems in low-temperature industrial applications is considered one of the most promising ways of improving energy efficiency and reducing the use of power during peak periods.In this study,the thermal performance of a shell-and-tube cold storage system under realistic operating conditions is investigated numerically.The proposed model is developed based on energy balances and then validated using existing experimental data from the literature.Glycol/water is used as the heat transfer fluid(HTF)and the phase transition phenomena in the phase change material(PCM)is simulated using the enthalpy-porosity approach.The influence of several design and operating parameters,including the HTF mass flow rate,HTF temperature,PCM type,and volume,on the cold storage performance during the crystallization process is presented and analyzed.The numerical results show that increasing the HTF mass flow rate accelerates the PCM crystallization process.However,the delivery periods of constant thermal power and constant HTF outlet temperature are reduced.The HTF inlet temperature has a significant effect on the cold storage performance,and the complete charging period is reduced by approximately 37%when the HTF inlet temperature is reduced from−4°C to−7°C.Increasing the number of tubes in the cold storage unit is concluded to significantly improve the thermal performance of the system,and using water/ice as a cold storage medium is more suitable than using the commercial PCMs RT2-HC and RT4-HC.Finally,the proposed numerical model for cold storage systems can be successfully used to design and simulate their realistic operation under different conditions.展开更多
Let R be a ring and n,k be two non-negative integers.As an extension of several known notions,we introduce and study(n,k)-weak cotorsion modules using the class of right R-modules with n-weak fat dimensions at most k....Let R be a ring and n,k be two non-negative integers.As an extension of several known notions,we introduce and study(n,k)-weak cotorsion modules using the class of right R-modules with n-weak fat dimensions at most k.Various examples and applications are also given.展开更多
The discrimination of neutrons from gamma rays in a mixed radiation field is crucial in neutron detection tasks.Several approaches have been proposed to enhance the performance and accuracy of neutron-gamma discrimina...The discrimination of neutrons from gamma rays in a mixed radiation field is crucial in neutron detection tasks.Several approaches have been proposed to enhance the performance and accuracy of neutron-gamma discrimination.However,their performances are often associated with certain factors,such as experimental requirements and resulting mixed signals.The main purpose of this study is to achieve fast and accurate neutron-gamma discrimination without a priori information on the signal to be analyzed,as well as the experimental setup.Here,a novel method is proposed based on two concepts.The first method exploits the power of nonnegative tensor factorization(NTF)as a blind source separation method to extract the original components from the mixture signals recorded at the output of the stilbene scintillator detector.The second one is based on the principles of support vector machine(SVM)to identify and discriminate these components.In addition to these two main methods,we adopted the Mexican-hat function as a continuous wavelet transform to characterize the components extracted using the NTF model.The resulting scalograms are processed as colored images,which are segmented into two distinct classes using the Otsu thresholding method to extract the features of interest of the neutrons and gamma-ray components from the background noise.We subsequently used principal component analysis to select the most significant of these features wich are used in the training and testing datasets for SVM.Bias-variance analysis is used to optimize the SVM model by finding the optimal level of model complexity with the highest possible generalization performance.In this framework,the obtained results have verified a suitable bias–variance trade-off value.We achieved an operational SVM prediction model for neutron-gamma classification with a high true-positive rate.The accuracy and performance of the SVM based on the NTF was evaluated and validated by comparing it to the charge comparison method via figure of merit.The results indicate that the proposed approach has a superior discrimination quality(figure of merit of 2.20).展开更多
Coronavirus disease 2019(COVID-19)is an infectious disease caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),declared as a pandemic due to its rapid spreadworldwide.In this study,we investigate the...Coronavirus disease 2019(COVID-19)is an infectious disease caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),declared as a pandemic due to its rapid spreadworldwide.In this study,we investigate the genetic diversity and genomic epidemiology of SARS-CoV-2,using 22 virus genome sequences reported by three different laboratories in Morocco till June 7,2020,as well as 40,366 virus genomes from all around the world.The SARSCoV-2 genomes from Moroccan patients revealed 62 mutations,of which 30weremis-sense mutations.Themutations Spike_D614G and NSP12_P323L were present in all the 22 analyzed sequences,followed by N_G204R and N_R203K,which occurred in 9 among the 22 sequences.The mutations NSP10_R134S,NSP15_D335N,NSP16_I169L,NSP3_L431H,NSP3_P1292L and Spike_V6F occurred once in Moroccan sequences,with no record in other sequences worldwide.Phylogenetic analyses revealed that Moroccan SARS-CoV-2 genomes included 9 viruses belonging to Clade 20A,9 to Clade 20B and 2 to Clade 20C,suggesting that the epidemic spread inMorocco did not display a predominant SARS-CoV-2 route.Therefore,multiple and unrelated introductions of SARS-CoV-2 into Morocco through different routes have occurred,giving rise to the diversity of virus genomes in the country.Further,in all probability,the SARS-CoV-2 circulated in a cryptic way inMorocco,starting fromJanuary 15,2020 before the first case was officially discovered on March 2,2020.展开更多
Water management in morocco faces significant challenges in both levels, quality and quantity, in order to address these challenges and to secure the rational and efficient management of water resources, it is necessa...Water management in morocco faces significant challenges in both levels, quality and quantity, in order to address these challenges and to secure the rational and efficient management of water resources, it is necessary to try to understand the different issues involved in the water cycle works! The large number of hydrological studies and techniques used at the Sebou watershed are limited to water quality, and the use of the simpler empirical models, that, do not permit to take into consideration all the factors affecting flow and cycle of water. In the purpose of using the hydrological model SWAT to study the hydrological functioning of the Sebou watershed (Morocco) which faces many problems regarding the management of its water resources like all the other watersheds in our country, this study focuses on the creation, organization and generation of input data (soil, soil occupation, climate…) using a GIS (ARCGIS) then, the configuration and calibration of the model and after that, the evaluation of the results. The main reason behind this work is to measure the adaptability of this model to the selected area in order to generalize the model to the whole Sebou watershed. The results are satisfying;they show that this model can represent the overall hydrological regime of the pilot basin Bab-Merzouka. This model can open up new perspectives regarding the effects of climate change, and the changes caused by humans on water resources, in terms of both quantity and quality.展开更多
In this paper,we introduce a new graph whose vertices are the non-zero zerodivisors of a commutativc ring R、and for distincts elements x and y in the set Z(R)^(*)of the non-zero zero-divisors of R,x and y are adjacen...In this paper,we introduce a new graph whose vertices are the non-zero zerodivisors of a commutativc ring R、and for distincts elements x and y in the set Z(R)^(*)of the non-zero zero-divisors of R,x and y are adjacent if and only if xy=0 or x+y∈Z(R).We present some properties and examples of this graph,and we study its relationship with the zero-divisor graph and with a subgraph of the total graph of a commutative ring.展开更多
文摘Conservation Agriculture(CA)covers more than 205 million hectares in the world.This made it possible to face and mitigate the challenges of climate change,reducing soil erosion and providing multiple ecosystem services.The first elementary factor influenced is the yield evaluation.It has a direct effect on farmers’choices for sustainable production.The present article records a review focused on wheat yield average positive change compared between conventional tillage(CT)and no tillage(NT)systems.The international database collected showed that NT is adaptable everywhere.The results of wheat yield differentiation showed the influence of crop rotation depending on stations located in different climatic zones.In more than 40 years of research,specialists have succeeded in demonstrating the importance of crop productivity like wheat.The whole integrates also experimentations where the initiation starts more than ten years.
基金supported by the Deanship of Scientific Research at Umm Al-Qura University(Grant code:22UQU4331128DSR77).
文摘Objective:To investigate the relationship between triterpenoid saponin content and antioxidant,antimicrobial,and α-glucosidase inhibitory activities of 70%ethanolic,butanolic,aqueous,supernate and precipitate extracts of Juglans regia leaves.Methods:Triterpenoid saponins of different Juglans regia leaf extracts were measured by the vanillin method.Antioxidant activity was evaluated against DPPH and ABTS free radicals.We also assessed α-glucosidase inhibitory and antimicrobial activities of the leaf extracts.Pearson’s correlation coefficient was evaluated to determine the correlation between the saponin content and biological activities.Results:The butanolic extract was most effective against DPPH with an IC50of 6.63μg/mL,while the aqueous extract showed the highest scavenging activity against ABTS free radical with an IC50of 42.27μg/mL.Pearson’s correlation analysis indicated a strong negative correlation (r=-0.956) between DPPH radical scavenging activity (IC50) and the saponin content in the samples examined.In addition,the aqueous extract showed the best α-glucosidase inhibitory activity compared with other extracts.All the extracts had fair antibacterial activity against Bacillus subtilis,Escherichia coli,and Klebsiella pneumoniae except for the aqueous extract.Conclusions:Juglans regia extracts show potent antioxidant,antimicrobial,and α-glucosidase inhibitory activities.There is a correlation between saponin levels in Juglans regia leaf extracts and the studied activities.However,additional research is required to establish these relationships by identifying the specific saponin molecules responsible for these activities and elucidating their mechanisms of action.
文摘Quantum correlations that surpass entanglement are of great importance in the realms of quantum information processing and quantum computation.Essentially,for quantum systems prepared in pure states,it is difficult to differentiate between quantum entanglement and quantum correlation.Nonetheless,this indistinguishability is no longer holds for mixed states.To contribute to a better understanding of this differentiation,we have explored a simple model for both generating and measuring these quantum correlations.Our study concerns two macroscopic mechanical resonators placed in separate Fabry–Pérot cavities,coupled through the photon hopping process.this system offers a comprehensively way to investigate and quantify quantum correlations beyond entanglement between these mechanical modes.The key ingredient in analyzing quantum correlation in this system is the global covariance matrix.It forms the basis for computing two essential metrics:the logarithmic negativity(E_(N)^(m))and the Gaussian interferometric power(P_(G)^(m)).These metrics provide the tools to measure the degree of quantum entanglement and quantum correlations,respectively.Our study reveals that the Gaussian interferometric power(P_(G)^(m))proves to be a more suitable metric for characterizing quantum correlations among the mechanical modes in an optomechanical quantum system,particularly in scenarios featuring resilient photon hopping.
文摘The Tarfaya-Laayoune-Boujdour basin is of great interest to oil exploration;on this aspect, there has been exploration by the Moroccan National Office of Hydrocarbons and Mining, which has shown indices of oil and/or gas recorded in most wells drilled in the Moroccan Atlantic margin. FD-1 well, object of this study, is one of these wells located in the offshore Tarfaya-Laayoune-Boujdour basin. A palynological examination of the processed samples revealed the existence of organic palynomorphs, well conserved and rich in dinoflagellate cysts. The latter are composed of worldwide marker taxa of high stratigraphic resolutions. Thus, the middle upper Albian (3408 - 3408.5 m) is determined by the presence of Cribroperidinium tensiftense, Tehamadinium coummia, Spiniferella cornuta, Chichaouadinium vestitum, Dinopterygium alatum and Litosphaeridium arundum. The upper Albian (3406.5 - 3408 m) is characterized by the FOs of marker taxa: Cyclonephelium chabaca, Cribroperidinium auctificum and Chichaouadinium vestitum. Lastly, the upper Albian-lower Cenomanian transition is defined between 3404 m and 3406.50 m, as suggested by the FOs of Chichaouadinium boydii, Dinopterygium tuberculatum, Sepispinula ancorifera, Litosphaeridium conispinum, Prolixosphaeridium conulum and Xenascus ceratioides.
基金funding from the European Union H2020 programme under Excellence research,ERC grant MOLEMAT(726360)PARASOL(RTI2018-102292-B-I00)from Spanish ministry of Science and Innovation。
文摘Mixed cation and anion based perovskites solar cells exhibited enhanced stability under outdoor conditions,however,it yielded limited power conversion efficiency when TiO_(2) and Spiro-OMeTAD were employed as electron and hole transport layer(ETL/HTL)respectively.The inevitable interfacial recombination of charge carriers at ETL/perovskite and perovskite/HTL interface diminished the efficiency in planar(n-i-p)perovskite solar cells.By employing computational approach for uni-dimensional device simulator,the effect of band offset on charge recombination at both interfaces was investigated.We noted that it acquired cliff structure when the conduction band minimum of the ETL was lower than that of the perovskite,and thus maximized interfacial recombination.However,if the conduction band minimum of ETL is higher than perovskite,a spike structure is formed,which improve the performance of solar cell.An optimum value of conduction band offset allows to reach performance of 25.21%,with an open circuit voltage(VOC)of 1231 mV,a current density JSC of 24.57 mA/cm^(2) and a fill factor of 83.28%.Additionally,we found that beyond the optimum offset value,large spike structure could decrease the performance.With an optimized energy level of Spiro-OMeTAD and the thickness of mixed-perovskite layer performance of 26.56% can be attained.Our results demonstrate a detailed understanding about the energy level tuning between the charge selective layers and perovskite and how the improvement in PV performance can be achieved by adjusting the energy level offset.
文摘This work is devoted to the study of the inhibition of corrosion of mild steel(MS)in molar hydrochloric acid(1 mol·L-1 HCl)by two named quinoxaline derivatives namely,2-(2,4-dichlorophenyl)-1,4-dihydroquinoxaline(HQ)and 2-(2,4-dichlorophenyl)-6-methyl-1,4-dihydroquinoxaline(CQ).The inhibitory efficacy of HQ and CQ compounds is first evaluated using the gravimetric method and using electrochemical techniques(stationary and transient techniques).The results showed that our compounds are efficient corrosion inhibitors and the inhibition rates(ηEIS%)reached up to 91%and 94.2%at 10-3 mol·L-1 for HQ and CQ,respectively.The mentioned molecules are classified as mixed-type inhibitors.The adsorption of these inhibitors on the surface of steel in hydrochloric HCl 1 mol·L-1 medium obeys the Langmuir adsorption isotherm.The results of the scanning electron microscope(SEM)showed the formation of a protective film on the surface of the steel in the presence of the inhibitors studied.Elementary analysis is obtained by energy dispersive X-ray spectroscopy(EDS).The inhibition property was further elucidated by theoretical approaches such as:Density Functional Theory(DFT),quantum chemical descriptors(QCD),local reactive indices,solvent effect,theoretical complexation,Molecular Dynamic(MD)simulation,effect of temperature on adsorption energy(Eads),Radial Distribution Function(RDF),and Mean Square Displacement(MSD).The results of these approaches support the experimental results.
文摘Magnetic hysteresis and compensation behavior of a mixed spin-(1, 3/2) Ising model on a square lattice are investigated in the framework of effective field theory based on a probability distribution technique. The effect of random crystal field, ferromagnetic and ferrimagnetic exchange interaction on hysteresis loops and compensation phenomenon are discussed. A number of characteristic phenomena have been reported such as the observation of triple hysteresis loops at low temperatures and for negative values of random crystal field. Critical and double compensation temperatures have been also found. The obtained results are also compared to some previous works.
文摘In this article we propose to combine an integrated method, the PCA-GMM method that generates a relatively improved segmentation outcome as compared to conventional GMM with Kalman Filtering (KF). The combined new method the PCA-GMM-KF attempts tracking multiple moving objects;the size and position of the objects along the sequence of their images in dynamic scenes. The obtained experimental results successfully illustrate the tracking of multiple moving objects based on this robust
文摘We report carbon stock in biomass, litter and soil estimated for six locations in natural Quercus ilex L. stands of the Middle and High Moroccan Atlas. Twenty trees at each location were selected according to their diameter classes and felled to measure the biomass of trunk, branches, twigs and leaves and determine allometric relationships. Soil was sampled in five depths (0 - 15, 15 - 30, 30 - 50, 50 - 70 and 70 - 100 cm) and litterfall production measured in all tree stands. The total carbon stock in above-ground biomass ranged between 17 Mg·haǃ in Aït Aamar stand (High Atlas) and 91 Mg·haǃ in Ksiba stand (Middle Atlas). Perennial organs (trunk, branches and twigs) stored over 95% of the tree carbon stock. Soil organic carbon concentrations ranged from 0.01% (in 70 - 100 cm in all stands) to 8.1% (in 0 - 15 cm in the Ajdir stand in Middle Atlas). The total organic carbon stock in the soil ranged between 141.4 t·haǃ in Ajdir and 24.6 t·haǃ in Asloul. The litter contained 0.2 Mg C haǃ in the clearing (C2) stand of High Atlas and 14.3 Mg C haǃ in (Ajdir) of carbon. The best fitted model for predicting carbon stock in tree biomass was obtained by applying the allometric equation Y = aXb for each biomass fraction and stand, where Y is the aboveground biomass (dry weight) and X is the DBH (Mean diameter at breast height, 1.30 m). These previous data obtained in the present study confirm the important function of these natural forests as longterm C sinks, in forest biomass, litter and soil. The potential long term C storage of these systems is moderately high, especially in less-intensively managed forests that include large trees. The established relationship between DBH and carbon stock in different tree organs can be used for forest carbon accounting, and also synthesize available information on oak forest as a sink for atmospheric CO2, and identify the management options that may enhance the capacity for C capture/ storage in forest soils.
文摘The phytoavailability of lead and chromium in cherry tomatoes Lycopersicon esculentum was studied both at the level of different parts of the plant (roots, stem, leaves and fruits) and at the level of its concentration in water and cultivation soil of. Two experiments are thence carried out by planting in bioponics, in a patented BIOTOP device, plants which are exposed via their root system to concentrations of 5 ppm, 10 ppm and 20 ppm of each contaminant (lead or chromium) in a nutrient solution. The results show that lead accumulates mainly in the roots with a significant amount as to allow its translocation into the stem and leaves, while only a small amount reaches the fruit. The results also show that when the concentration increases the lead content in the roots also increases, but decreases in the fruits with three floral bouquets. Conversely, the chromium substance decreases in the roots and increases in the fruit. Based on these results, we note that the average distribution of lead in the edible part of the plant is much higher than that of chromium, and also lead presence in the plant is higher compared to that of chromium.
基金financially supported by University of Mohammed V-Morocco under the Project No.SCH 04/09 and HassanⅡAcademy of Science and Technology,Morocco.
文摘The Democratic Republic of the Congo holds important reserves of oil shale which is still under geological status.Herein,the characterization and pyrolysis kinetics of typeⅠkerogen-rich oil shale of the western Central Kongo(CK)were investigated.X-ray diffraction,Fourier-transform infrared spectroscopy and thermal analysis(TG/DTA)showed that CK oil shale exhibits a siliceous mineral matrix with a consistent organic matter rich in aliphatic chains.The pyrolysis behavior of kerogen revealed the presence of a single mass loss between 300 and 550°C,estimated at 12.5%and attributed to the oil production stage.Non-isothermal kinetics was performed by determining the activation energy using the iterative isoconversional model-free methods and exhibits a constant value with E=211.5±4.7 kJ mol.1.The most probable kinetic model describing the kerogen pyrolysis mechanism was obtained using the Coats–Redfern and Arrhenius plot methods.The results showed a unique kinetic triplet confirming the nature of kerogen,predominantly typeⅠand reinforcing the previously reported geochemical characteristics of the CK oil shale.Besides,the calculation of thermodynamic parameters(ΔH~*,ΔS~*andΔG~*)corresponding to the pyrolysis of typeⅠkerogen revealed that the process is non-spontaneous,in agreement with DTA experiments.
文摘We investigate the generation of quantum correlations between mechanical modes and optical modes in an optomechanical system,using the rotating wave approximation.The system is composed of two Fabry-Pérot cavities separated in space;each of the two cavities has a movable end-mirror.Our aim is the evaluation of entanglement between mechanical modes and optical modes,generated by correlations transfer from the squeezed light to the system,using Gaussian intrinsic entanglement as a witness of entanglement in continuous variables Gaussian states,and the quantification of the degree of mixedness of the Gaussian states using the purity.Then,we quantify nonclassical correlations between mechanical modes and optical modes even beyond entanglement by considering Gaussian geometric discord via the Hellinger distance.Indeed,entanglement,mixdness,and quantum discord are analyzed as a function of the parameters characterizing the system(thermal bath temperature,squeezing parameter,and optomechanical cooperativity).We find that,under thermal effect,when entanglement vanishes,purity and quantum discord remain nonzero.Remarkably,the Gaussian Hellinger discord is more robust than entanglement.The effects of the other parameters are discussed in detail.
文摘Our calculations are based on the modeling technique and simulation Ab-Initio that appeals to the Density Functional Theory (DFT) relying on the Full-Potential Linearized Augmented Plane Waves (FP-LAPW) method that requires a calculation process using approximations such as Local Density (LDA) and Generalized Gradient (GGA) developed in the modelling software of nanostructures WIEN2k. The optimal structure of the binary semiconductor ZnSe crystallizing in the complex phase of Zinc Blende (B3) was determined by studying the variation of energy depending on the volume of the elementary cell. Then the electronic properties of the optimized state were analyzed such as the gap energy, the total density of states (TDOS), the partial density of states (PDOS) and the repartition of the electronic charge density. The obtained results were successful compared with other theoretical and experimental values reported in literature.
文摘The use of cold thermal storage systems in low-temperature industrial applications is considered one of the most promising ways of improving energy efficiency and reducing the use of power during peak periods.In this study,the thermal performance of a shell-and-tube cold storage system under realistic operating conditions is investigated numerically.The proposed model is developed based on energy balances and then validated using existing experimental data from the literature.Glycol/water is used as the heat transfer fluid(HTF)and the phase transition phenomena in the phase change material(PCM)is simulated using the enthalpy-porosity approach.The influence of several design and operating parameters,including the HTF mass flow rate,HTF temperature,PCM type,and volume,on the cold storage performance during the crystallization process is presented and analyzed.The numerical results show that increasing the HTF mass flow rate accelerates the PCM crystallization process.However,the delivery periods of constant thermal power and constant HTF outlet temperature are reduced.The HTF inlet temperature has a significant effect on the cold storage performance,and the complete charging period is reduced by approximately 37%when the HTF inlet temperature is reduced from−4°C to−7°C.Increasing the number of tubes in the cold storage unit is concluded to significantly improve the thermal performance of the system,and using water/ice as a cold storage medium is more suitable than using the commercial PCMs RT2-HC and RT4-HC.Finally,the proposed numerical model for cold storage systems can be successfully used to design and simulate their realistic operation under different conditions.
文摘Let R be a ring and n,k be two non-negative integers.As an extension of several known notions,we introduce and study(n,k)-weak cotorsion modules using the class of right R-modules with n-weak fat dimensions at most k.Various examples and applications are also given.
基金L’Ore´al-UNESCO for the Women in Science Maghreb Program Grant Agreement No.4500410340.
文摘The discrimination of neutrons from gamma rays in a mixed radiation field is crucial in neutron detection tasks.Several approaches have been proposed to enhance the performance and accuracy of neutron-gamma discrimination.However,their performances are often associated with certain factors,such as experimental requirements and resulting mixed signals.The main purpose of this study is to achieve fast and accurate neutron-gamma discrimination without a priori information on the signal to be analyzed,as well as the experimental setup.Here,a novel method is proposed based on two concepts.The first method exploits the power of nonnegative tensor factorization(NTF)as a blind source separation method to extract the original components from the mixture signals recorded at the output of the stilbene scintillator detector.The second one is based on the principles of support vector machine(SVM)to identify and discriminate these components.In addition to these two main methods,we adopted the Mexican-hat function as a continuous wavelet transform to characterize the components extracted using the NTF model.The resulting scalograms are processed as colored images,which are segmented into two distinct classes using the Otsu thresholding method to extract the features of interest of the neutrons and gamma-ray components from the background noise.We subsequently used principal component analysis to select the most significant of these features wich are used in the training and testing datasets for SVM.Bias-variance analysis is used to optimize the SVM model by finding the optimal level of model complexity with the highest possible generalization performance.In this framework,the obtained results have verified a suitable bias–variance trade-off value.We achieved an operational SVM prediction model for neutron-gamma classification with a high true-positive rate.The accuracy and performance of the SVM based on the NTF was evaluated and validated by comparing it to the charge comparison method via figure of merit.The results indicate that the proposed approach has a superior discrimination quality(figure of merit of 2.20).
文摘Coronavirus disease 2019(COVID-19)is an infectious disease caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),declared as a pandemic due to its rapid spreadworldwide.In this study,we investigate the genetic diversity and genomic epidemiology of SARS-CoV-2,using 22 virus genome sequences reported by three different laboratories in Morocco till June 7,2020,as well as 40,366 virus genomes from all around the world.The SARSCoV-2 genomes from Moroccan patients revealed 62 mutations,of which 30weremis-sense mutations.Themutations Spike_D614G and NSP12_P323L were present in all the 22 analyzed sequences,followed by N_G204R and N_R203K,which occurred in 9 among the 22 sequences.The mutations NSP10_R134S,NSP15_D335N,NSP16_I169L,NSP3_L431H,NSP3_P1292L and Spike_V6F occurred once in Moroccan sequences,with no record in other sequences worldwide.Phylogenetic analyses revealed that Moroccan SARS-CoV-2 genomes included 9 viruses belonging to Clade 20A,9 to Clade 20B and 2 to Clade 20C,suggesting that the epidemic spread inMorocco did not display a predominant SARS-CoV-2 route.Therefore,multiple and unrelated introductions of SARS-CoV-2 into Morocco through different routes have occurred,giving rise to the diversity of virus genomes in the country.Further,in all probability,the SARS-CoV-2 circulated in a cryptic way inMorocco,starting fromJanuary 15,2020 before the first case was officially discovered on March 2,2020.
文摘Water management in morocco faces significant challenges in both levels, quality and quantity, in order to address these challenges and to secure the rational and efficient management of water resources, it is necessary to try to understand the different issues involved in the water cycle works! The large number of hydrological studies and techniques used at the Sebou watershed are limited to water quality, and the use of the simpler empirical models, that, do not permit to take into consideration all the factors affecting flow and cycle of water. In the purpose of using the hydrological model SWAT to study the hydrological functioning of the Sebou watershed (Morocco) which faces many problems regarding the management of its water resources like all the other watersheds in our country, this study focuses on the creation, organization and generation of input data (soil, soil occupation, climate…) using a GIS (ARCGIS) then, the configuration and calibration of the model and after that, the evaluation of the results. The main reason behind this work is to measure the adaptability of this model to the selected area in order to generalize the model to the whole Sebou watershed. The results are satisfying;they show that this model can represent the overall hydrological regime of the pilot basin Bab-Merzouka. This model can open up new perspectives regarding the effects of climate change, and the changes caused by humans on water resources, in terms of both quantity and quality.
文摘In this paper,we introduce a new graph whose vertices are the non-zero zerodivisors of a commutativc ring R、and for distincts elements x and y in the set Z(R)^(*)of the non-zero zero-divisors of R,x and y are adjacent if and only if xy=0 or x+y∈Z(R).We present some properties and examples of this graph,and we study its relationship with the zero-divisor graph and with a subgraph of the total graph of a commutative ring.