The study is based on a bibliometric analysis of scientific knowledge on geoheritage,geotourism,geoconservation and geoparks in Africa,using data from the Scopus database for the period 1999-2022.The results reveal an...The study is based on a bibliometric analysis of scientific knowledge on geoheritage,geotourism,geoconservation and geoparks in Africa,using data from the Scopus database for the period 1999-2022.The results reveal an exponential growth in research in these fields,characterised by two distinct phases,while highlighting the remarkable productivity of certain African countries,such as Morocco,South Africa,Egypt and Ethiopia.These results provide an overview of the trend in research on geoheritage,geoconservation,geotourism and geoparks in Africa,and make it possible to monitor the evolution of scientific research and identify research priorities across the continent.This approach is proving extremely useful in providing crucial information to the research community,practitioners and decision-makers who are seeking to understand the dynamics of these disciplines in Africa,and wish to actively contribute to their development.展开更多
The Mekkam inlier is located 50 km southeast of the town of Taourirt,in northeastern Morocco.It offers a great opportunity for the study of Variscan magmatism in Morocco.This inlier is punctuated by small magmatic bod...The Mekkam inlier is located 50 km southeast of the town of Taourirt,in northeastern Morocco.It offers a great opportunity for the study of Variscan magmatism in Morocco.This inlier is punctuated by small magmatic bodies which we will characterize through a petrographic and geochemical study to situate this inlier in its geotectonic context.The petrographic study revealed the existence of three trends:acidic,intermediate,and basic,which are represented by facies ranging from granites to basanites,including andesites,rhyolites,trachytes,dacites,quartz microdiorites,Aplite and microgranites.All these facies have a mineralogical assemblage dominated by quartz,plagioclase,oligoclase,potassium feldspar,pyroxene,and biotite;the most abundant accessory minerals are zircon and apatite.Green hornblende is found in microdiorites and dacites.The geochemical analysis,conducted through the examination of major elements,trace elements,and rare earth elements,has uncovered the presence of two distinct magmatic series:a calc-alkaline series of the island arc type or active continental margin,and another alkaline series of syn-collision.Based on this combined data,we propose that the Mekkam sector represents a magmatic arc developed within a compressional tectonic regime located above a subduction zone,which was later followed by an intracontinental collision phase.展开更多
In this paper,a detailed investigation of water(Pr=7.0)convection in a chemical condenser is carried out.Two openings are located along one side of the cavity.The Navier-Stokes equations are solved in the frame of a c...In this paper,a detailed investigation of water(Pr=7.0)convection in a chemical condenser is carried out.Two openings are located along one side of the cavity.The Navier-Stokes equations are solved in the frame of a control volume method using the SIMPLEC algorithm to implement adequate coupling of pressure and velocity.Special emphasis is given to the influence of the Reynolds number,the tilt of the channel and the Rayleigh number on the convective heat transfer.Results are presented and discussed allowing the control parameters to span relatively wide intervals:Rayleigh number(10^(4)≤Ra≤5×10^(5)),channel inclination(0°≤90°)and Reynolds number(10≤Re≤1000).On the basis of these results,a new correlation of the Nusselt number is elaborated.展开更多
This paper proposes a new set of 3D rotation scaling and translation invariants of 3D radially shifted Legendre moments. We aim to develop two kinds of transformed shifted Legendre moments： a 3D substituted radial sh...This paper proposes a new set of 3D rotation scaling and translation invariants of 3D radially shifted Legendre moments. We aim to develop two kinds of transformed shifted Legendre moments： a 3D substituted radial shifted Legendre moments （3DSRSLMs） and a 3D weighted radial one （3DWRSLMs）. Both are centered on two types of polynomials. In the first case, a new 3D ra- dial complex moment is proposed. In the second case, new 3D substituted/weighted radial shifted Legendremoments （3DSRSLMs/3DWRSLMs） are introduced using a spherical representation of volumetric image. 3D invariants as derived from the sug- gested 3D radial shifted Legendre moments will appear in the third case. To confirm the proposed approach, we have resolved three is- sues. To confirm the proposed approach, we have resolved three issues： rotation, scaling and translation invariants. The result of experi- ments shows that the 3DSRSLMs and 3DWRSLMs have done better than the 3D radial complex moments with and without noise. Sim- ultaneously, the reconstruction converges rapidly to the original image using 3D radial 3DSRSLMs and 3DWRSLMs, and the test of 3D images are clearly recognized from a set of images that are available in Princeton shape benchmark （PSB） database for 3D image.展开更多
We introduce a new wavelet based procedure for detecting outliers in financial discrete time series.The procedure focuses on the analysis of residuals obtained from a model fit,and applied to the Generalized Autoregre...We introduce a new wavelet based procedure for detecting outliers in financial discrete time series.The procedure focuses on the analysis of residuals obtained from a model fit,and applied to the Generalized Autoregressive Conditional Heteroskedasticity(GARCH)like model,but not limited to these models.We apply the Maximal-Overlap Discrete Wavelet Transform(MODWT)to the residuals and compare their wavelet coefficients against quantile thresholds to detect outliers.Our methodology has several advantages over existing methods that make use of the standard Discrete Wavelet Transform(DWT).The series sample size does not need to be a power of 2 and the transform can explore any wavelet filter and be run up to the desired level.Simulated wavelet quantiles from a Normal and Student t-distribution are used as threshold for the maximum of the absolute value of wavelet coefficients.The performance of the procedure is illustrated and applied to two real series:the closed price of the Saudi Stock market and the S&P 500 index respectively.The efficiency of the proposed method is demonstrated and can be considered as a distinct important addition to the existing methods.展开更多
This paper discusses the integration between GIS and hydrological models and presents a case study relating to the upper section of Moulouya River Basin (UMRB) situated in the east of Morocco. The Basin is an inland w...This paper discusses the integration between GIS and hydrological models and presents a case study relating to the upper section of Moulouya River Basin (UMRB) situated in the east of Morocco. The Basin is an inland water-shed with a total area of approximately 10,000 km2, stretching in the junction between the Middle Atlas, the High Atlas Mountain and the Middle Moulouya basin. From ArcGIS ArcHydro framework data models, different parameters of the Moulouya River and its catchment area have been defined. DEM based ArcHydro model was run on Aster-GDEM V2 data at a horizontal spatial resolution of 30 meters. Several raster and vector products of the Upper Moulouya River and its catchment area have been defined at the end of the model. Final results of the models were discussed and compared with the reality. These results can be used in baseline for advanced hydrology and geomorphology research on the catchment area. They can support for decision-making on ground and surface water resource, distribution and management.展开更多
This study evaluates the annual loss of soil in the sub-basin of Oued Haricha (Tahaddart basin, Western Rif, NW Morocco). The integration of revised (RUSLE) and modified (MUSLE) soil loss empirical equations of Wischm...This study evaluates the annual loss of soil in the sub-basin of Oued Haricha (Tahaddart basin, Western Rif, NW Morocco). The integration of revised (RUSLE) and modified (MUSLE) soil loss empirical equations of Wischmeier and Smith in combination with GIS permits the modelling of soil erosion at the scale of parcels. The characteristics of precipitation and runoff, the soil properties, the culture system and the current working practices of soil in the sub-basin of the Oued Haricha are collected from local data. The digital terrain model is used to generate topographic factors. The combination of different RUSLE factors shows that the annual soil is 62.72 t/ha/year and corresponds to an average level of risk. The total losses calculated by MUSLE method are valued at 221,468 t/year. The rates of loss due to linear erosion are 82,652 t/year. These soil losses represent 20.33% of the total losses, and confirm that the losses on the slopes outweigh the losses due to the river system. Sedimentation module shows that the areas of high erosion (greater than 200 t/ha/year) are concentrated in the reliefs with average and high slope and occupy 38% of the total area. The deposition areas occupy the centre of sub-basin and constitute 9.12% of the total area. These deposits were concentrated on the edges of major rivers and the outlet of the sub-basin and contributed to siltation of the April 9, 1947 dam.展开更多
Until recently,the main pharmaceuticals used to control cholesterol and prevent cardiovascular disease(CVD)were statin-related drugs,known for their historical side effects.Therefore,there is growing interest in explo...Until recently,the main pharmaceuticals used to control cholesterol and prevent cardiovascular disease(CVD)were statin-related drugs,known for their historical side effects.Therefore,there is growing interest in exploring alternatives,such as nutritional and dietary components,that could play a central role in CVD prevention.This review aims to provide a comprehensive understanding of how natural phytosterols found in various diets combat CVDs.We begin with a description of the overall approach,then we explore in detail the different direct and indirect mechanisms that contribute to reducing cardiovascular incidents.Phytosterols,including stigmasterol,β-sitosterol,ergosterol,and fucosterol,emerge as promising molecules within nutritional systems for protection against CVDs due to their beneficial effects at different levels through direct or indirect cellular,subcellular,and molecular mechanisms.Specifically,the mentioned phytosterols exhibit the ability to diminish the generation of various radicals,including hydroperoxides and hydrogen peroxide.They also promote the activation of antioxidant enzymes such as superoxide dismutase,catalase,and glutathione,while inhibiting lipid peroxidation through the activation of Nrf2 and Nrf2/heme oxygenase-1(HO-1)signaling pathways.Additionally,they demonstrate a significant inhibitory capacity in the generation of pro-inflammatory cytokines,thus playing a crucial role in regulating the inflammatory/immune response by inhibiting the expression of proteins involved in cellular signaling pathways such as JAK3/STAT3 and NF-κB.Moreover,phytosterols play a key role in reducing cholesterol absorption and improving the lipid profile.These compounds can be used as dietary supplements or included in specific diets to aid control cholesterol levels,particularly in individuals suffering from hypercholesterolemia.展开更多
Satellite image classification is crucial in various applications such as urban planning,environmental monitoring,and land use analysis.In this study,the authors present a comparative analysis of different supervised ...Satellite image classification is crucial in various applications such as urban planning,environmental monitoring,and land use analysis.In this study,the authors present a comparative analysis of different supervised and unsupervised learning methods for satellite image classification,focusing on a case study in Casablanca using Landsat 8 imagery.This research aims to identify the most effective machine-learning approach for accurately classifying land cover in an urban environment.The methodology used consists of the pre-processing of Landsat imagery data from Casablanca city,the authors extract relevant features and partition them into training and test sets,and then use random forest(RF),SVM(support vector machine),classification,and regression tree(CART),gradient tree boost(GTB),decision tree(DT),and minimum distance(MD)algorithms.Through a series of experiments,the authors evaluate the performance of each machine learning method in terms of accuracy,and Kappa coefficient.This work shows that random forest is the best-performing algorithm,with an accuracy of 95.42%and 0.94 Kappa coefficient.The authors discuss the factors of their performance,including data characteristics,accurate selection,and model influencing.展开更多
Amorphous hydrogenated silicon nitride thin films a-SiN<sub>x</sub>:H (abbreviated later by SiN<sub>x</sub>) were deposited by Electron Cyclotron Resonance plasma enhanced chemical vapor deposi...Amorphous hydrogenated silicon nitride thin films a-SiN<sub>x</sub>:H (abbreviated later by SiN<sub>x</sub>) were deposited by Electron Cyclotron Resonance plasma enhanced chemical vapor deposition method (ECR-PECVD). By changing ratio of gas flow (R = NH<sub>3</sub>/SiH<sub>4</sub>) in the reactor chamber different stoichiometric layers x = [N]/[Si] ([N] and [Si] atomic concentrations) are successfully deposited. Part of the obtained films has subsequently undergone rapid thermal annealing RTA (800°C/1 s) using halogen lamps. Optical and structural characterizations are then achieved by spectroscopic ellipsometry (SE), ion beam analysis and infrared absorption techniques. The SE measurements show that the tuning character of their refractive index n(λ) with stoichiometry x and their non-absorption properties in the range of 250 - 850 nm expect for Si-rich SiN<sub>x</sub> films in the ultraviolet UV range. The stoichiometry x and its depth profile are determined by Rutherford backscattering spectrometry (RBS) while the hydrogen profile (atomic concentration) is determined by Elastic Recoil Detection Analysis (ERDA). Vibrational characteristics of the Si-N, Si-H and N-H chemical bonds in the silicon nitride matrix are investigated by infrared absorption. An atomic hydrogen fraction ranging from 12% to 22% uniformly distributed as evaluated by ERDA is depending inversely on the stoichiometry x ranging from 0.34 to 1.46 as evaluated by RBS for the studied SiN<sub>x</sub> films. The hydrogen loss after RTA process and its out-diffusion depend strongly on the chemical structure of the films and less on the initial hydrogen concentration. A large hydrogen loss was noted for non-thermally stable Si-rich SiNx films. Rich nitrogen films are less sensitive to rapid thermal process.展开更多
In this paper we study the solutions and stability of the generalized Wilson＇s functional equation fc f（xty）dtt（t） ＋ fc f（xtσ（y））dtt（t） =2f（x）g（y）, x,y C G, where G is a locally compact group, a is a ...In this paper we study the solutions and stability of the generalized Wilson＇s functional equation fc f（xty）dtt（t） ＋ fc f（xtσ（y））dtt（t） =2f（x）g（y）, x,y C G, where G is a locally compact group, a is a continuous involution of G and # is an idempotent complex measure with compact support and which is a-invariant. We show that ∫Gg（xty）dp（t） ＋ fcg（xta（y））dp（t） = 2g（x）g（y） if f = 0 and fcf（t.）dp（t） =0, where [fcf（t.）dp（t）]（x） = fc f（tx）dμ（t）. We also study some stability theorems of that equation and we establish the stability on noncommutative groups of the classical Wilson＇s functional equation f（xy） ＋ X（y）f（xa（y）） = 2f（x）g（y） x, y C G, where X is a unitary character of G.展开更多
The aim of our study was to explore the antioxidant potential of Moroccan saffron stigmas(SS) and examine their performance as a natural antioxidant in enhancing the stability and quality properties of edible sunflowe...The aim of our study was to explore the antioxidant potential of Moroccan saffron stigmas(SS) and examine their performance as a natural antioxidant in enhancing the stability and quality properties of edible sunflower oil(SO), with a focus on understanding the critical importance of edible oil stability for predicting quality deterioration during storage. Bearing this in mind, our research was designed to compare the efficacy of three concentrations of dried SS(at 0.2%, 0.3%, and 0.6%) against tocobiol(a synthetic antioxidant) as a positive control(at 0.3% concentration). This comparison was conducted under three distinct storage conditions namely accelerated ageing(60 ℃), exposure to light at ambient temperature, and darkness, to evaluate their impact on preventing severe oxidation and extending oil shelf-life. Oxidation state evolution was evaluated through peroxide value(PV), free fatty acid(FFA), anisidine value(p-AV), K_(270)value(conjugated trienes), total oxidation index(TOTOX), iodine value(IV), and fatty acid composition(FA). Our results revealed notable differences in stability tracking parameters. Specifically, these parameters were higher in samples stored under accelerated conditions, followed by the samples stored in ambient light, while those stored in darkness showed the highest stability among the three storage conditions. Supplementation of sunflower oil with SS and tocobiol significantly enhanced its oxidation stability. Notably, SS exhibited exceptional effectiveness in stabilizing sunflower oil regardless of SS dose, with the highest efficacy observed at 0.6%. This was evidenced by the slower rate of oxidation parameters under various storage conditions, highlighting a superior antioxidant activity compared to both the non-enriched oil and tocobiol-enriched oil. Furthermore, saffron stigmas, used as a natural supplement,contributed to the preservation of polyunsaturated fatty acids, indicating its potential as a robust source of natural antioxidants in sunflower oil. These attributes position SS as a promising alternative to synthetic antioxidants, offering opportunities to enhance the nutritional quality and extend edible oil shelf-life.展开更多
The Laguerre polynomial method has been successfully used to investigate the dynamic responses of a half-space.However,it fails to obtain the correct stress at the interfaces in a layered half-space,especially when th...The Laguerre polynomial method has been successfully used to investigate the dynamic responses of a half-space.However,it fails to obtain the correct stress at the interfaces in a layered half-space,especially when there are significant differences in material properties.Therefore,a coupled Legendre-Laguerre polynomial method with analytical integration is proposed.The Rayleigh waves in a one-dimensional(1D)hexagonal quasicrystal(QC)layered half-space with an imperfect interface are investigated.The correctness is validated by comparison with available results.Its computation efficiency is analyzed.The dispersion curves of the phase velocity,displacement distributions,and stress distributions are illustrated.The effects of the phonon-phason coupling and imperfect interface coefficients on the wave characteristics are investigated.Some novel findings reveal that the proposed method is highly efficient for addressing the Rayleigh waves in a QC layered half-space.It can save over 99%of the computation time.This method can be expanded to investigate waves in various layered half-spaces,including earth-layered media and surface acoustic wave(SAW)devices.展开更多
Objective:To study the chemical profile,antimicrobial properties,and synergistic effect with known antibiotics of essential oil extracted from the marine red macroalgae Centroceras clavulatum(C.Agardh)Montagne,collect...Objective:To study the chemical profile,antimicrobial properties,and synergistic effect with known antibiotics of essential oil extracted from the marine red macroalgae Centroceras clavulatum(C.Agardh)Montagne,collected in Morocco.Methods:The chemical composition of the oil was analyzed by gas chromatography-mass spectrometry.The oil was evaluated for antibacterial(Pseudomonas aeruginosa,Escherichia coli,Bacillus subtilis,Micrococcus luteus,Staphylococcus aureus,and Klebsiella pneumoniae),and antifungal activity(Candida albicans,Candida glabrata,Candida krusei,and Candida parapsilosis),by the disc diffusion method.The minimum inhibitory and minimum microbicidal concentrations of the oil were determined,as well as the synergistic effects of its application combined with the antibiotics ciprofloxacin and fluconazole,by the checkerboard method.Results:Thirty molecules were identified in the essential oil,comprising 96.27%of the total oil composition.Monoterpenes such as carvacrol(36.06%)were the most abundant compounds,followed by caryophyllene(14.67%),endo-borneol(9.04%),pyroterebic acid(3.23%)and caryophyllene oxide(3.13%).The oil exhibited a moderate antimicrobial activity with inhibition zone diameters ranging from 9.0 to 15.0 mm.The minimum inhibitory concentration values varied between 0.9 and 14.7 mg/mL,and Bacillus subtilis and Escherichia coli were the more sensitive bacteria with 0.9 and 1.9 mg/mL,respectively.The minimum microbicidal concentration values ranged from 0.4 to 14.7 mg/mL.A significant synergic action was observed when the oil was applied in combination with ciprofloxacin and fluconazole,with fractional inhibitory concentration index values ranging from 0.31 to 0.50.Synergy was found in 80%of the combinations and a 2 to 16-fold reduction of antibiotics MIC was observed.Conclusions:Our findings suggest that the essential oil of Centroceras clavulatum should be further appraised for its potential use in the management of multi-drug resistant microorganisms,with the purpose to restore the activity of standard antimicrobial drugs.展开更多
Nanofluids are a potential alternative to significantly improving the performance of heat transfer applications. In this work, a numerical analysis to examine the eff ect of dispersing copper(Cu), copper oxide(CuO), a...Nanofluids are a potential alternative to significantly improving the performance of heat transfer applications. In this work, a numerical analysis to examine the eff ect of dispersing copper(Cu), copper oxide(CuO), and aluminum(Al2O3) nanoparticles in pure water on the performance of a flat plate solar collector(FPSC) and a numerical model was proposed. The influence of the nanofluid type on the thermal efficiency was critically investigated and discussed. The eff ect of the mass flow rate on the performance was also analyzed and discussed. Based on correlations of the thermophysical properties of nanofluids, a sensitivity analysis was used to analyze the impact of the nanoparticles on the base fluid. The results indicate that the performance of the FPSC with Cu/water nanofluid was better than that of FPSCs using CuO/water or Al2O3/water nanofluids. When the mass flow rate of the nanofluids was 8.0 L/min, the efficiency of the FPSC was much greater than those at the flow rates of 5.0 L/min and 2.0 L/min. Mean enhancements in thermal efficiency of 4.44%, 4.27%, and 4.21% were observed when 2.0 L/min was applied using Cu/water, Cu O/water, and Al2O3/water nanofluids, respectively. Improvements in thermal efficiency of 2.76%, 2.53%, and 2.47% occurred when 8.0 L/min was applied.展开更多
Following the example of other industrial activities, mining evaluation is now exposed to socio-economical and technological constraints which are unstable in quick evolution. The keys to its success are increasingly ...Following the example of other industrial activities, mining evaluation is now exposed to socio-economical and technological constraints which are unstable in quick evolution. The keys to its success are increasingly related to a methodology of work more scientific than ever. The Systemic Approach has broadly showed its effectiveness in numerous disciplinary fields, both scientific and engineering ones: Biology, Economy, Social and Management Sciences, Quality Management, Information Systems… Helped by technological progress, this approach has especially excelled in the management of spatial information (e.g. GIS). It constitutes therefore an excellent solution to the problems of mining evaluation by the integration of genetic, mining and managerial data within an Information System, thus optimizing scientific and economic valuation of mineral resources.展开更多
The Hercynian massif of the central Jebilet (Morocco) is characterized by the outcrop of many gossans with great economic importance. This work focuses on interpreting gravity data of Benslimane gossan, located about ...The Hercynian massif of the central Jebilet (Morocco) is characterized by the outcrop of many gossans with great economic importance. This work focuses on interpreting gravity data of Benslimane gossan, located about thirty kilometres to the North-West of Marrakech. The residual gravity map of the study area highlights several anomalies which coincide with the mining and geological contexts. Applying edge detection methods, for example, tilt angle derivative (TDR), the total horizontal derivative of the tilt angle derivative (HDR_TDR) and the 3D Euler deconvolution, allowed us to estimate the depth of the Benslimane deposit. As a result, the average depth of the ore deposit was estimated to exceed 200 m. The results are promising, and the processing methods must be applied to the other gossan in the Jebilet massif for further exploration studies.展开更多
The purpose of this research is to define initial parameters of Inaouene river and its catchment areas using radar data and satellite data. The Inaouene river is situated at the east of Sebou basin in North-East of Mo...The purpose of this research is to define initial parameters of Inaouene river and its catchment areas using radar data and satellite data. The Inaouene river is situated at the east of Sebou basin in North-East of Morocco. The study has been done by two dataset: 1) Shuttle Radar Topography Mission (SRTM) at a horizontal spatial resolution of 90 meters, and 2) ASTER (Advanced Spaceborn Thermal Emissionand and Reflection Radiometer) of GDEM version 2 at a horizontal spatial resolution of 30 meters, using ArcHydro model. Several raster and vector products of the Inaouene river and its catchment area have been defined at the end of the model. Moreover, final results of the ArcHydro model were compared with each other and with the reality. The result of this study can be used in baseline and advanced hydrology and geomorphology research on the catchment area. Besides of that, the result can define a spatial boundary of study on Inaouene River and its catchment area. Moreover, it would have support for decision-making on ground and surface water resource, distribution and management.展开更多
A field experiment was carried out in arid area to assess the influence of mycorrhizal inoculation with a native complex and bio-compost addition on establishment of Argania spinosa. The experimental area was located ...A field experiment was carried out in arid area to assess the influence of mycorrhizal inoculation with a native complex and bio-compost addition on establishment of Argania spinosa. The experimental area was located in the Admine forest at Agadir (Southwestern Morocco). The results showed a positive effect of arbuscular mycorrhizal fungi (AMF) on the growth of Argania spinosa seedlings in the nursery. Six months after planting, the mycorrhizal complex revealed an increase in the growth of Argan seedlings (51%) compared to non mycorrhizal plants. In the field conditions, after one year of transplantation, this benefit was maintained. Results showed that the height of Argan seedlings treated with AMF was double that of the control group. An additional positive effect of inoculation with AMF on plant biomass was observed and it was closely related to colonization by these microorganisms. There was an estimated 169% increase in biomass compared to control plants. The use of bio-compost alone or in combination with AMF improved the production of shoot biomass of Argan plants (84% and 108% respectively compared to control plants). In addition, AMF improved the survival rate and the contents of nitrogen (N) and phosphorus (P) in the tissues of A. spinosa plants. A significant positive correlation between dry biomass and nutrient content in plant tissue was detected. The content of (P) in the leaves and roots of inoculated plants was higher than those in non-inoculated and planted seedlings in amended soils. This result reaffirms the prime necessity of mycorrhiza in arid conditions. Thus the introduction of mycorrhizal fungi in forest nurseries is a key tool to improve the quality of seedlings produced and their resistance in reforestation sites.展开更多
The characteristic of flow and heat transfer of A12Oa-water nanofluids flowing through a horizontal ventilated cavity is investigated numerically. The bottom wall is subjected to a linearly varying increasing heating ...The characteristic of flow and heat transfer of A12Oa-water nanofluids flowing through a horizontal ventilated cavity is investigated numerically. The bottom wall is subjected to a linearly varying increasing heating temperature profile, whereas the other boundaries are assumed to be thermally insulated. The enclosure is cooled by an injected or sucked imposed flow. The simulations are focused specifically on the effects of different key parameters such as Reynolds number, 200 〈 Re 〈 5,000, nanoparticles concentration, 0 〈 φ 〈 0.1, and mode of imposed flow, on the flow and thermal patterns and heat transfer performances. The findings demonstrate clearly the positive role of the nanoparticles addition on the improvement of the heat transfer rate and the mean temperature within the cavity. Also, the results presented show that, the suction mode is more favorable to the heat transfer in comparison with the case of the injection mode. The cooling efficiency is found to be more pronounced by applying the suction mode.展开更多
文摘The study is based on a bibliometric analysis of scientific knowledge on geoheritage,geotourism,geoconservation and geoparks in Africa,using data from the Scopus database for the period 1999-2022.The results reveal an exponential growth in research in these fields,characterised by two distinct phases,while highlighting the remarkable productivity of certain African countries,such as Morocco,South Africa,Egypt and Ethiopia.These results provide an overview of the trend in research on geoheritage,geoconservation,geotourism and geoparks in Africa,and make it possible to monitor the evolution of scientific research and identify research priorities across the continent.This approach is proving extremely useful in providing crucial information to the research community,practitioners and decision-makers who are seeking to understand the dynamics of these disciplines in Africa,and wish to actively contribute to their development.
文摘The Mekkam inlier is located 50 km southeast of the town of Taourirt,in northeastern Morocco.It offers a great opportunity for the study of Variscan magmatism in Morocco.This inlier is punctuated by small magmatic bodies which we will characterize through a petrographic and geochemical study to situate this inlier in its geotectonic context.The petrographic study revealed the existence of three trends:acidic,intermediate,and basic,which are represented by facies ranging from granites to basanites,including andesites,rhyolites,trachytes,dacites,quartz microdiorites,Aplite and microgranites.All these facies have a mineralogical assemblage dominated by quartz,plagioclase,oligoclase,potassium feldspar,pyroxene,and biotite;the most abundant accessory minerals are zircon and apatite.Green hornblende is found in microdiorites and dacites.The geochemical analysis,conducted through the examination of major elements,trace elements,and rare earth elements,has uncovered the presence of two distinct magmatic series:a calc-alkaline series of the island arc type or active continental margin,and another alkaline series of syn-collision.Based on this combined data,we propose that the Mekkam sector represents a magmatic arc developed within a compressional tectonic regime located above a subduction zone,which was later followed by an intracontinental collision phase.
文摘In this paper,a detailed investigation of water(Pr=7.0)convection in a chemical condenser is carried out.Two openings are located along one side of the cavity.The Navier-Stokes equations are solved in the frame of a control volume method using the SIMPLEC algorithm to implement adequate coupling of pressure and velocity.Special emphasis is given to the influence of the Reynolds number,the tilt of the channel and the Rayleigh number on the convective heat transfer.Results are presented and discussed allowing the control parameters to span relatively wide intervals:Rayleigh number(10^(4)≤Ra≤5×10^(5)),channel inclination(0°≤90°)and Reynolds number(10≤Re≤1000).On the basis of these results,a new correlation of the Nusselt number is elaborated.
文摘This paper proposes a new set of 3D rotation scaling and translation invariants of 3D radially shifted Legendre moments. We aim to develop two kinds of transformed shifted Legendre moments： a 3D substituted radial shifted Legendre moments （3DSRSLMs） and a 3D weighted radial one （3DWRSLMs）. Both are centered on two types of polynomials. In the first case, a new 3D ra- dial complex moment is proposed. In the second case, new 3D substituted/weighted radial shifted Legendremoments （3DSRSLMs/3DWRSLMs） are introduced using a spherical representation of volumetric image. 3D invariants as derived from the sug- gested 3D radial shifted Legendre moments will appear in the third case. To confirm the proposed approach, we have resolved three is- sues. To confirm the proposed approach, we have resolved three issues： rotation, scaling and translation invariants. The result of experi- ments shows that the 3DSRSLMs and 3DWRSLMs have done better than the 3D radial complex moments with and without noise. Sim- ultaneously, the reconstruction converges rapidly to the original image using 3D radial 3DSRSLMs and 3DWRSLMs, and the test of 3D images are clearly recognized from a set of images that are available in Princeton shape benchmark （PSB） database for 3D image.
文摘We introduce a new wavelet based procedure for detecting outliers in financial discrete time series.The procedure focuses on the analysis of residuals obtained from a model fit,and applied to the Generalized Autoregressive Conditional Heteroskedasticity(GARCH)like model,but not limited to these models.We apply the Maximal-Overlap Discrete Wavelet Transform(MODWT)to the residuals and compare their wavelet coefficients against quantile thresholds to detect outliers.Our methodology has several advantages over existing methods that make use of the standard Discrete Wavelet Transform(DWT).The series sample size does not need to be a power of 2 and the transform can explore any wavelet filter and be run up to the desired level.Simulated wavelet quantiles from a Normal and Student t-distribution are used as threshold for the maximum of the absolute value of wavelet coefficients.The performance of the procedure is illustrated and applied to two real series:the closed price of the Saudi Stock market and the S&P 500 index respectively.The efficiency of the proposed method is demonstrated and can be considered as a distinct important addition to the existing methods.
文摘This paper discusses the integration between GIS and hydrological models and presents a case study relating to the upper section of Moulouya River Basin (UMRB) situated in the east of Morocco. The Basin is an inland water-shed with a total area of approximately 10,000 km2, stretching in the junction between the Middle Atlas, the High Atlas Mountain and the Middle Moulouya basin. From ArcGIS ArcHydro framework data models, different parameters of the Moulouya River and its catchment area have been defined. DEM based ArcHydro model was run on Aster-GDEM V2 data at a horizontal spatial resolution of 30 meters. Several raster and vector products of the Upper Moulouya River and its catchment area have been defined at the end of the model. Final results of the models were discussed and compared with the reality. These results can be used in baseline for advanced hydrology and geomorphology research on the catchment area. They can support for decision-making on ground and surface water resource, distribution and management.
文摘This study evaluates the annual loss of soil in the sub-basin of Oued Haricha (Tahaddart basin, Western Rif, NW Morocco). The integration of revised (RUSLE) and modified (MUSLE) soil loss empirical equations of Wischmeier and Smith in combination with GIS permits the modelling of soil erosion at the scale of parcels. The characteristics of precipitation and runoff, the soil properties, the culture system and the current working practices of soil in the sub-basin of the Oued Haricha are collected from local data. The digital terrain model is used to generate topographic factors. The combination of different RUSLE factors shows that the annual soil is 62.72 t/ha/year and corresponds to an average level of risk. The total losses calculated by MUSLE method are valued at 221,468 t/year. The rates of loss due to linear erosion are 82,652 t/year. These soil losses represent 20.33% of the total losses, and confirm that the losses on the slopes outweigh the losses due to the river system. Sedimentation module shows that the areas of high erosion (greater than 200 t/ha/year) are concentrated in the reliefs with average and high slope and occupy 38% of the total area. The deposition areas occupy the centre of sub-basin and constitute 9.12% of the total area. These deposits were concentrated on the edges of major rivers and the outlet of the sub-basin and contributed to siltation of the April 9, 1947 dam.
基金funded by the Deputyship for Research and Innovation,Ministry of Education in Saudi Arabia(Project number ISP23-81)Sunway University Research Accelerator Grant Scheme(GRTIN-RAG-SBMDC-10-2024).
文摘Until recently,the main pharmaceuticals used to control cholesterol and prevent cardiovascular disease(CVD)were statin-related drugs,known for their historical side effects.Therefore,there is growing interest in exploring alternatives,such as nutritional and dietary components,that could play a central role in CVD prevention.This review aims to provide a comprehensive understanding of how natural phytosterols found in various diets combat CVDs.We begin with a description of the overall approach,then we explore in detail the different direct and indirect mechanisms that contribute to reducing cardiovascular incidents.Phytosterols,including stigmasterol,β-sitosterol,ergosterol,and fucosterol,emerge as promising molecules within nutritional systems for protection against CVDs due to their beneficial effects at different levels through direct or indirect cellular,subcellular,and molecular mechanisms.Specifically,the mentioned phytosterols exhibit the ability to diminish the generation of various radicals,including hydroperoxides and hydrogen peroxide.They also promote the activation of antioxidant enzymes such as superoxide dismutase,catalase,and glutathione,while inhibiting lipid peroxidation through the activation of Nrf2 and Nrf2/heme oxygenase-1(HO-1)signaling pathways.Additionally,they demonstrate a significant inhibitory capacity in the generation of pro-inflammatory cytokines,thus playing a crucial role in regulating the inflammatory/immune response by inhibiting the expression of proteins involved in cellular signaling pathways such as JAK3/STAT3 and NF-κB.Moreover,phytosterols play a key role in reducing cholesterol absorption and improving the lipid profile.These compounds can be used as dietary supplements or included in specific diets to aid control cholesterol levels,particularly in individuals suffering from hypercholesterolemia.
文摘Satellite image classification is crucial in various applications such as urban planning,environmental monitoring,and land use analysis.In this study,the authors present a comparative analysis of different supervised and unsupervised learning methods for satellite image classification,focusing on a case study in Casablanca using Landsat 8 imagery.This research aims to identify the most effective machine-learning approach for accurately classifying land cover in an urban environment.The methodology used consists of the pre-processing of Landsat imagery data from Casablanca city,the authors extract relevant features and partition them into training and test sets,and then use random forest(RF),SVM(support vector machine),classification,and regression tree(CART),gradient tree boost(GTB),decision tree(DT),and minimum distance(MD)algorithms.Through a series of experiments,the authors evaluate the performance of each machine learning method in terms of accuracy,and Kappa coefficient.This work shows that random forest is the best-performing algorithm,with an accuracy of 95.42%and 0.94 Kappa coefficient.The authors discuss the factors of their performance,including data characteristics,accurate selection,and model influencing.
文摘Amorphous hydrogenated silicon nitride thin films a-SiN<sub>x</sub>:H (abbreviated later by SiN<sub>x</sub>) were deposited by Electron Cyclotron Resonance plasma enhanced chemical vapor deposition method (ECR-PECVD). By changing ratio of gas flow (R = NH<sub>3</sub>/SiH<sub>4</sub>) in the reactor chamber different stoichiometric layers x = [N]/[Si] ([N] and [Si] atomic concentrations) are successfully deposited. Part of the obtained films has subsequently undergone rapid thermal annealing RTA (800°C/1 s) using halogen lamps. Optical and structural characterizations are then achieved by spectroscopic ellipsometry (SE), ion beam analysis and infrared absorption techniques. The SE measurements show that the tuning character of their refractive index n(λ) with stoichiometry x and their non-absorption properties in the range of 250 - 850 nm expect for Si-rich SiN<sub>x</sub> films in the ultraviolet UV range. The stoichiometry x and its depth profile are determined by Rutherford backscattering spectrometry (RBS) while the hydrogen profile (atomic concentration) is determined by Elastic Recoil Detection Analysis (ERDA). Vibrational characteristics of the Si-N, Si-H and N-H chemical bonds in the silicon nitride matrix are investigated by infrared absorption. An atomic hydrogen fraction ranging from 12% to 22% uniformly distributed as evaluated by ERDA is depending inversely on the stoichiometry x ranging from 0.34 to 1.46 as evaluated by RBS for the studied SiN<sub>x</sub> films. The hydrogen loss after RTA process and its out-diffusion depend strongly on the chemical structure of the films and less on the initial hydrogen concentration. A large hydrogen loss was noted for non-thermally stable Si-rich SiNx films. Rich nitrogen films are less sensitive to rapid thermal process.
文摘In this paper we study the solutions and stability of the generalized Wilson＇s functional equation fc f（xty）dtt（t） ＋ fc f（xtσ（y））dtt（t） =2f（x）g（y）, x,y C G, where G is a locally compact group, a is a continuous involution of G and # is an idempotent complex measure with compact support and which is a-invariant. We show that ∫Gg（xty）dp（t） ＋ fcg（xta（y））dp（t） = 2g（x）g（y） if f = 0 and fcf（t.）dp（t） =0, where [fcf（t.）dp（t）]（x） = fc f（tx）dμ（t）. We also study some stability theorems of that equation and we establish the stability on noncommutative groups of the classical Wilson＇s functional equation f（xy） ＋ X（y）f（xa（y）） = 2f（x）g（y） x, y C G, where X is a unitary character of G.
文摘The aim of our study was to explore the antioxidant potential of Moroccan saffron stigmas(SS) and examine their performance as a natural antioxidant in enhancing the stability and quality properties of edible sunflower oil(SO), with a focus on understanding the critical importance of edible oil stability for predicting quality deterioration during storage. Bearing this in mind, our research was designed to compare the efficacy of three concentrations of dried SS(at 0.2%, 0.3%, and 0.6%) against tocobiol(a synthetic antioxidant) as a positive control(at 0.3% concentration). This comparison was conducted under three distinct storage conditions namely accelerated ageing(60 ℃), exposure to light at ambient temperature, and darkness, to evaluate their impact on preventing severe oxidation and extending oil shelf-life. Oxidation state evolution was evaluated through peroxide value(PV), free fatty acid(FFA), anisidine value(p-AV), K_(270)value(conjugated trienes), total oxidation index(TOTOX), iodine value(IV), and fatty acid composition(FA). Our results revealed notable differences in stability tracking parameters. Specifically, these parameters were higher in samples stored under accelerated conditions, followed by the samples stored in ambient light, while those stored in darkness showed the highest stability among the three storage conditions. Supplementation of sunflower oil with SS and tocobiol significantly enhanced its oxidation stability. Notably, SS exhibited exceptional effectiveness in stabilizing sunflower oil regardless of SS dose, with the highest efficacy observed at 0.6%. This was evidenced by the slower rate of oxidation parameters under various storage conditions, highlighting a superior antioxidant activity compared to both the non-enriched oil and tocobiol-enriched oil. Furthermore, saffron stigmas, used as a natural supplement,contributed to the preservation of polyunsaturated fatty acids, indicating its potential as a robust source of natural antioxidants in sunflower oil. These attributes position SS as a promising alternative to synthetic antioxidants, offering opportunities to enhance the nutritional quality and extend edible oil shelf-life.
基金Project supported by the National Natural Science Foundation of China(No.12102131)the Natural Science Foundation of Henan Province of China(No.242300420248)the International Science and Technology Cooperation Project of Henan Province of China(No.242102521010)。
文摘The Laguerre polynomial method has been successfully used to investigate the dynamic responses of a half-space.However,it fails to obtain the correct stress at the interfaces in a layered half-space,especially when there are significant differences in material properties.Therefore,a coupled Legendre-Laguerre polynomial method with analytical integration is proposed.The Rayleigh waves in a one-dimensional(1D)hexagonal quasicrystal(QC)layered half-space with an imperfect interface are investigated.The correctness is validated by comparison with available results.Its computation efficiency is analyzed.The dispersion curves of the phase velocity,displacement distributions,and stress distributions are illustrated.The effects of the phonon-phason coupling and imperfect interface coefficients on the wave characteristics are investigated.Some novel findings reveal that the proposed method is highly efficient for addressing the Rayleigh waves in a QC layered half-space.It can save over 99%of the computation time.This method can be expanded to investigate waves in various layered half-spaces,including earth-layered media and surface acoustic wave(SAW)devices.
基金the Researchers Supporting Project number(RSP-2021/56)King Saud University,Riyadh,Saudi Arabia+2 种基金the Foundation for Science and Technology(FCT)the Portuguese National Budget for the UIDB/04326/2019 projectthe FCT Scientific Employment Stimulus(CEECIND/00425/2017).
文摘Objective:To study the chemical profile,antimicrobial properties,and synergistic effect with known antibiotics of essential oil extracted from the marine red macroalgae Centroceras clavulatum(C.Agardh)Montagne,collected in Morocco.Methods:The chemical composition of the oil was analyzed by gas chromatography-mass spectrometry.The oil was evaluated for antibacterial(Pseudomonas aeruginosa,Escherichia coli,Bacillus subtilis,Micrococcus luteus,Staphylococcus aureus,and Klebsiella pneumoniae),and antifungal activity(Candida albicans,Candida glabrata,Candida krusei,and Candida parapsilosis),by the disc diffusion method.The minimum inhibitory and minimum microbicidal concentrations of the oil were determined,as well as the synergistic effects of its application combined with the antibiotics ciprofloxacin and fluconazole,by the checkerboard method.Results:Thirty molecules were identified in the essential oil,comprising 96.27%of the total oil composition.Monoterpenes such as carvacrol(36.06%)were the most abundant compounds,followed by caryophyllene(14.67%),endo-borneol(9.04%),pyroterebic acid(3.23%)and caryophyllene oxide(3.13%).The oil exhibited a moderate antimicrobial activity with inhibition zone diameters ranging from 9.0 to 15.0 mm.The minimum inhibitory concentration values varied between 0.9 and 14.7 mg/mL,and Bacillus subtilis and Escherichia coli were the more sensitive bacteria with 0.9 and 1.9 mg/mL,respectively.The minimum microbicidal concentration values ranged from 0.4 to 14.7 mg/mL.A significant synergic action was observed when the oil was applied in combination with ciprofloxacin and fluconazole,with fractional inhibitory concentration index values ranging from 0.31 to 0.50.Synergy was found in 80%of the combinations and a 2 to 16-fold reduction of antibiotics MIC was observed.Conclusions:Our findings suggest that the essential oil of Centroceras clavulatum should be further appraised for its potential use in the management of multi-drug resistant microorganisms,with the purpose to restore the activity of standard antimicrobial drugs.
文摘Nanofluids are a potential alternative to significantly improving the performance of heat transfer applications. In this work, a numerical analysis to examine the eff ect of dispersing copper(Cu), copper oxide(CuO), and aluminum(Al2O3) nanoparticles in pure water on the performance of a flat plate solar collector(FPSC) and a numerical model was proposed. The influence of the nanofluid type on the thermal efficiency was critically investigated and discussed. The eff ect of the mass flow rate on the performance was also analyzed and discussed. Based on correlations of the thermophysical properties of nanofluids, a sensitivity analysis was used to analyze the impact of the nanoparticles on the base fluid. The results indicate that the performance of the FPSC with Cu/water nanofluid was better than that of FPSCs using CuO/water or Al2O3/water nanofluids. When the mass flow rate of the nanofluids was 8.0 L/min, the efficiency of the FPSC was much greater than those at the flow rates of 5.0 L/min and 2.0 L/min. Mean enhancements in thermal efficiency of 4.44%, 4.27%, and 4.21% were observed when 2.0 L/min was applied using Cu/water, Cu O/water, and Al2O3/water nanofluids, respectively. Improvements in thermal efficiency of 2.76%, 2.53%, and 2.47% occurred when 8.0 L/min was applied.
文摘Following the example of other industrial activities, mining evaluation is now exposed to socio-economical and technological constraints which are unstable in quick evolution. The keys to its success are increasingly related to a methodology of work more scientific than ever. The Systemic Approach has broadly showed its effectiveness in numerous disciplinary fields, both scientific and engineering ones: Biology, Economy, Social and Management Sciences, Quality Management, Information Systems… Helped by technological progress, this approach has especially excelled in the management of spatial information (e.g. GIS). It constitutes therefore an excellent solution to the problems of mining evaluation by the integration of genetic, mining and managerial data within an Information System, thus optimizing scientific and economic valuation of mineral resources.
文摘The Hercynian massif of the central Jebilet (Morocco) is characterized by the outcrop of many gossans with great economic importance. This work focuses on interpreting gravity data of Benslimane gossan, located about thirty kilometres to the North-West of Marrakech. The residual gravity map of the study area highlights several anomalies which coincide with the mining and geological contexts. Applying edge detection methods, for example, tilt angle derivative (TDR), the total horizontal derivative of the tilt angle derivative (HDR_TDR) and the 3D Euler deconvolution, allowed us to estimate the depth of the Benslimane deposit. As a result, the average depth of the ore deposit was estimated to exceed 200 m. The results are promising, and the processing methods must be applied to the other gossan in the Jebilet massif for further exploration studies.
文摘The purpose of this research is to define initial parameters of Inaouene river and its catchment areas using radar data and satellite data. The Inaouene river is situated at the east of Sebou basin in North-East of Morocco. The study has been done by two dataset: 1) Shuttle Radar Topography Mission (SRTM) at a horizontal spatial resolution of 90 meters, and 2) ASTER (Advanced Spaceborn Thermal Emissionand and Reflection Radiometer) of GDEM version 2 at a horizontal spatial resolution of 30 meters, using ArcHydro model. Several raster and vector products of the Inaouene river and its catchment area have been defined at the end of the model. Moreover, final results of the ArcHydro model were compared with each other and with the reality. The result of this study can be used in baseline and advanced hydrology and geomorphology research on the catchment area. Besides of that, the result can define a spatial boundary of study on Inaouene River and its catchment area. Moreover, it would have support for decision-making on ground and surface water resource, distribution and management.
文摘A field experiment was carried out in arid area to assess the influence of mycorrhizal inoculation with a native complex and bio-compost addition on establishment of Argania spinosa. The experimental area was located in the Admine forest at Agadir (Southwestern Morocco). The results showed a positive effect of arbuscular mycorrhizal fungi (AMF) on the growth of Argania spinosa seedlings in the nursery. Six months after planting, the mycorrhizal complex revealed an increase in the growth of Argan seedlings (51%) compared to non mycorrhizal plants. In the field conditions, after one year of transplantation, this benefit was maintained. Results showed that the height of Argan seedlings treated with AMF was double that of the control group. An additional positive effect of inoculation with AMF on plant biomass was observed and it was closely related to colonization by these microorganisms. There was an estimated 169% increase in biomass compared to control plants. The use of bio-compost alone or in combination with AMF improved the production of shoot biomass of Argan plants (84% and 108% respectively compared to control plants). In addition, AMF improved the survival rate and the contents of nitrogen (N) and phosphorus (P) in the tissues of A. spinosa plants. A significant positive correlation between dry biomass and nutrient content in plant tissue was detected. The content of (P) in the leaves and roots of inoculated plants was higher than those in non-inoculated and planted seedlings in amended soils. This result reaffirms the prime necessity of mycorrhiza in arid conditions. Thus the introduction of mycorrhizal fungi in forest nurseries is a key tool to improve the quality of seedlings produced and their resistance in reforestation sites.
文摘The characteristic of flow and heat transfer of A12Oa-water nanofluids flowing through a horizontal ventilated cavity is investigated numerically. The bottom wall is subjected to a linearly varying increasing heating temperature profile, whereas the other boundaries are assumed to be thermally insulated. The enclosure is cooled by an injected or sucked imposed flow. The simulations are focused specifically on the effects of different key parameters such as Reynolds number, 200 〈 Re 〈 5,000, nanoparticles concentration, 0 〈 φ 〈 0.1, and mode of imposed flow, on the flow and thermal patterns and heat transfer performances. The findings demonstrate clearly the positive role of the nanoparticles addition on the improvement of the heat transfer rate and the mean temperature within the cavity. Also, the results presented show that, the suction mode is more favorable to the heat transfer in comparison with the case of the injection mode. The cooling efficiency is found to be more pronounced by applying the suction mode.
