Quantification du transport solide par la technique floue, application au barrage de Beni Amrane (Algérie)

L’Algérie, caractérisée par un climat semi-aride, est menacée par l’érosion des terres agricoles qui provoque l’augmentation du transport solide et l’envasement croissant des barrages. Cet article décrit une nouvelle méthode d’estimation des flux de matières en suspension (MES) au niveau d’un barrage algérien (barrage de Beni Amrane) basée sur la logique floue. Cette dernière utilise des termes flous tels que « faible », « moyen » et « élevé », pour décomposer le processus débit-MES en plusieurs sous-ensembles flous et d’en déduire les quantités de matières solides en fonction du débit observé de la rivière. Les performances de cette méthode ont été évaluées en période de calage, mais aussi en période de validation, pour mieux juger de la capacité prédictive du modèle à ces deux échelles. En comparant la logique floue avec un modèle empirique régressif utilisant une relation de puissance, nous avons démontré la robustesse du modèle flou en tant qu’outil de quantification du transport solide.Sediment transport and erosion is a complex natural process that is strongly influenced by human activities such as deforestation, agriculture and urbanization. In particular, suspended sediments play a key role in controlling water quality and they can cause a major reduction in the capacity of a stream for handling floods. In Algeria, increasing erosion and suspended loads are responsible for serious problems in agricultural land and hydraulic reservoirs, since the suspended load and its sedimentation lead to flooding and dam silting. Water and soil conservation practices, such as contour ridges and areas of reforestation, were introduced in many regions of Algeria in order to decrease erosion and to collect runoff in hill-slope catchments.Relationships for water discharge and suspended sediment load can be divided into three types: empirical models that allow quantification of erosion on annual time scales, such as the Wischmeier and Smith soil loss equation; conceptual models, which include several reservoirs estimating sediment load on different time scales; and finally, physically-based models, which introduce physical laws such as the Saint-Venant equation. These models represent another category, and allow the estimation of sediment load in different areas of the watershed and supply spatial results. These models also take into account numerous variables that are difficult to obtain on a regional scale.The objective of this research was to develop runoff-suspended sediment models for the Beni Amrane reservoir. This reservoir is located in the Isser watershed, situated in northern Algeria. This basin covers an area of 4,000 km2 and is characterized by a semi-arid climate and a very high soil erosion rate, exceeding 2,000 tons/km2/year. The Beni Amrane reservoir represents an important dam as it supplies the Keddara dam, which in turn supplies the town of Algiers with drinking water.In the present study, two approaches to suspended sediment simulation were applied on hourly time scales for suspended sediment concentrations, and on daily time scales for water discharge and solid discharge analysis. The first approach is an empirical regression model based on a rating curve and uses a relationship between the observed runoff and the sediment concentration values. The model uses only two parameters, with the second being based on fuzzy logic. Fuzzy logic is already used in many scientific domains, and represents a new simulation technique based on artificial intelligence. Fuzzy variables were used to organize knowledge that is expressed ‘linguistically’ into a formal analysis (for example ‘high suspended sediment’, ‘average suspended sediment’ and ‘low suspended sediment’). The simulation results confirm the performances and robustness of the fuzzy logic model for the two time scales. In fact, the Nash criterion, which is the principal validation criterion for the models, displayed high performances in calibration and validation periods. The neurofuzzy model (fuzzy logic with neural supervised learning) offers a simulation advantage. On an hourly time scale, while increasing the number of fuzzy rules, the model results in good precision with the observed suspended sediments.The fuzzy logic model results showed that the Nash criterion for two periods (calibration and validation) was greater than 88%, and the peaks of suspended sediments were generally correctly reproduced for the four episodes studied. This is in contrast to the empirical model, where the Nash efficiency was generally weak and decreased during the validation period. In this latter period, the Nash criterion was often negative, the global error was high and the maximum concentration peak was underestimated.On a daily time scale, knowing the complexity of the runoff-suspended sediment process, we have analyzed these two models for solid discharge simulation. The study was carried out on daily solid discharge data collected from the gauging station on the Isser River (1986 to 1989). While based on the same validation criteria, i.e. the Nash efficiency and the global error, the fuzzy logic model appeared more robust than the empirical model. The fuzzy logic model produced better estimates of the daily sediment yield than the empirical model during calibration and validation periods, and it represents a high prediction power. Thus, we have validated the fuzzy logic model as a tool for simulation of runoff of suspended sediments, and it can be explored to predict sediment loading and silting in Algerian reservoirs

HPLC/ESI-MS Characterization of Phenolic Compounds from Cnicus benedictus L. Roots: A Study of Antioxidant, Antibacterial, Anti-Inflammatory, and Anti-Alzheimer's Activity.

peer reviewedThe phenolic composition of Cnicus benedictus roots from four Algerian regions was investigated. Extractions were performed in both hydro-methanolic (30 : 70, v/v) and hydro-ethanolic (30 : 70, v/v) solvents. Their efficiency was determined in terms of the qualitative and quantitative composition in phenolic compounds by HPLC-LC/MS of the different extracts isolated from C. Benedictus roots. Cnicus benedictus roots extract have been characterized by high content of phenolic compounds, where the trans chalcone, 2,3-dihydro flavone, 3-hydroxy flavone and cinnamic acid constitute the major components, in addition to fourteen minor acidic compounds and flavonoids as rutin. The hydro-methanolic extract was the richest in phenolic compounds yield from C benedictus. On the other hand, hydro methanolic (30 : 70, v/v) and hydro ethanolic (30 : 70, v/v) extracts exhibited a high anti-inflammatory activity by in vitro 5-lipoxygenase inhibitory activity (IC50 : 6.05±94.16 μg/mL) as well as by in silico docking according two methods. Likewise, anti-Alzheimer activity of extracts was confirmed by this last technique taking into account the major compounds identified. Antibacterial tests revealed interesting results compared to amoxicillin for the different regions studied with a high content in trans chalcone and 3-hydroxy Flavone

Positive Solution for the Integral and Infinite Point Boundary Value Problem for Fractional-Order Differential Equation Involving a Generalized ϕ-Laplacian Operator

In this paper, we establish the existence of nontrivial positive solution to the following integral-infinite point boundary-value problem involving ϕ-Laplacian operator D0+αϕx,D0+βux+fx,ux=0,x∈0,1,D0+σu0=D0+βu0=0,u1=∫01 gtutdt+∑n=1n=+∞ αnuηn, where ϕ:0,1×R→R is a continuous function and D0+p is the Riemann-Liouville derivative for p∈α,β,σ. By using some properties of fixed point index, we obtain the existence results and give an example at last

Existence and Uniqueness Results of Positive Solution of A Class of Singular Duffing Oscillators

In this paper, we give existence and uniqueness results of nontrivial positive solution of the singular and non-autonomous kind of Duffing oscillator by using fixed point index theory

Chemical composition and physicochemical characteristics of fixed oils from Algerian Nigella sativa seeds

The fatty acids, sterols, and polyphenols from the fixed oils of Nigella sativa seeds originating from four locations were determined. The seeds contained respectively 30.63–34.27% and 25.66–32.77% of fixed oils using hexane and isopropyl alcohol in solvent extraction. Linoleic, oleic, and palmitic acids formed the main proportion using the two solvents, respectively: hexane 54.47–61.28%, isopropanol 56.98–67.30%; hexane 19.62–22.94%, isopropanol 18.85–21.96%, and hexane 11.17–13.60%, isopropanol 9.20–14.18%. Other minor unsaturated fatty acids were identified. Eight phytosterols were isolated and identified in the fixed oils by GC and GC/MS analysis, wherein -sitosterol was the dominating compound that inhibits the absorption of dietary cholesterol, followed by stigmasterol, campesterol, and 5-avenasterol

Kinetic study of volatile oil of Curcuma longa L. rhizome and Carum carvi L. fruits extracted by microwave-assisted techniques using the cryogrinding

peer reviewedHydrodistillation assisted by microwave (HDAM) and steam distillation assisted by microwave (SDAM) of Curcuma longa L. rhizome (CL) and Carum carvi fruits (CC) were investigated. The effect of the cryogrinding (CG) showed differences in yields and composition of volatile oils compared with classical grinding. HDAM–CG (CL: 1.20%, CC: 1.25%) and SDAM–CG (CL: 1.45%, CC: 1.75%) allowed extraction of substantial amounts of volatile oils in less time compared with HDAM (CL: 0.6%, CC: 1.00%) and SDAM (CL: 0.90%, CC: 1.00%). In addition, the major amounts of volatile oils were globally obtained during the first 5 and 10 minutes of extraction for CL and CC, respectively. A kinetic study of essential oils extraction from CL and CC was quantitatively performed. The composition of the major components and family classes present a significant variation with the extraction time. Essential oils extracted by these two methods were quantitatively (yield) and qualitatively [aromatic profile by gas chromatography (GC) and GC–mass spectrometry (GC–MS)] analyzed. There were differences, especially in the major compounds ar-turmerone (HDAM: 46.00–57.96%, HDAM–CG: 30.85–60.32%) and β-turmerone (HDAM: 14.43–16.74%, HDAM–CG: 10.46–15.77%) for CL, and limonene (HDAM: 23.61–56.97%, HDAM–CG: 38.04–43.00%) and carvone (HDAM: 36.19–64.54%, CC–CG: 53.65–56.31%) for CC