A geostatistical approach for groundwater head monitoring network optimisation: case of the Sfax superficial aquifer (Tunisia)

In many developing countries, the groundwater monitoring network is randomly designed, and consequently needs to be revised and optimised to reduce operation time and cost, remove redundant piezometric data, and strengthen sparseness data zone with supplementary observation well. The geostatistical approach used in this work is based on the universal kriging variance combined with cross‐validation test. Hence, a rational interpolation of water table elevations was performed to evaluate the accuracy of data employed in the piezometric head modelling. In this study, the groundwater monitoring network of the Sfax superficial aquifer in the south east of Tunisia was optimised. The elimination of five observation wells induces the invariability in the variance of estimate due to their less contribution in interpretations of the groundwater level behaviour. However, 38 wells were added at areas of high variance of the kriging in order to ameliorate the spatial coverage of the monitoring network.     

A multi-level conceptual data reduction approach based on the Lukasiewicz implication

Starting from fuzzy binary data represented as tables in the fuzzy relational database, in this paper, we use fuzzy formal concept analysis to reduce the tables size to only keep the minimal rows in each table, without losing knowledge (i.e., association rules extracted from reduced databases are identical at given precision level). More specifically, we develop a fuzzy extension of a previously proposed algorithm for crisp data reduction without loss of knowledge. The fuzzy Galois connection based on the Lukasiewicz implication is mainly used in the definition of the closure operator according to a precision level, which makes data reduction sensitive to the variation of this precision level.     

Essential oil composition,phenolic compound,and antioxidant potential of Inulaviscosa as affected by extraction process

The purpose of this study was to compare the essential oil composition of Inula viscosa leaves by hydrodistillation (HDE), ultrasonic (UDE) and solvent (SE) extractions followed by hydrodistillation. The total polyphenol and flavonoid contents and their antioxidant effects were studied by different solvent of extraction: ethanol (ET), ethyl acetate (EA), methanol (ME) and aqueous (AE). The principal compounds for HDE were: 2-hexenal (3.70%), caryophyllene oxide (3.11%), γ-selinene (3.09%), 3-hexen-1-ol (2.00%), eugenol (1.70%) and trans-caryophyllene (1.34%), while for UDE were: γ-selinene (5.68%), caryophyllene oxide (4.87%), trans-caryophyllene (1.99%) and nerolidol (1.74%). The oil obtained by SE was shown to contain tridecane (3.89%), dodecane (3.08%), trans-caryophyllene (2.94%), caryophyllene oxide (2.56%) and nerolidol (2.53%). Significant changes on phenolic contents were found between the different solvent of extraction. ME and AE extracts led to the highest total polyphenol (PHL) and flavonoid (FL) amounts. The anti-radical activity and reducing power were maximal in AE and ME extract. HPLC examination established that the ferulic acid as major phenolic acid in ME and AE fractions, whereas luteolin was the main compound of EA and ET fractions.     

Effects of Extraction Solvents and Provenances on Phenolic Contents and Antioxidant Activities of Cumin (Cuminum cyminum L.) Seeds

Polyphenol contents and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activity of cumin (Cuminum cyminum L.) seed extracts were compared depending on their geographical origin (Tunisia and India: TCS and ICS, respectively) and the extraction solvent polarity. The ??-carotene bleaching assay, the chelating ability and the reducing power of the most promising solvent extracts were also assessed. In addition, TCS and ICS extracts were acid-hydrolyzed and the phenolics identified by reversed-phase high-performance liquid chromatography (HPLC). Seed phenolic contents and antioxidant activity appeared to be accession and solvent dependent. Extraction with 80% acetone led to the highest polyphenol (18.60 and 16.50?mg gallic acid equivalents (GAE)/g dry weight (DW)), flavonoid (5.91 and 4.99?mg catechin equivalents (CE)/g DW) and tannin (83.23 and 80.23?mg CE/g DW) contents, respectively for TCS and ICS. DPPH scavenging activity, ??-carotene bleaching assay, chelating ability and reducing power were maximal in 80% acetone for both TCS and ICS. HPLC analysis revealed several phenolic compounds in C. cyminum seeds, with p-coumaric (4.83 and 2.33?mg/g DW), trans-2-dihydrocinnamic (1.09 and 1.20?mg/g DW) and rosmarinic (0.70 and 1.04?mg/g DW) acids as major phenolics in TCS and ICS, respectively. Thus, phenolic composition of cumin seeds is also origin dependent. Taken together, our findings indicate that cumin might constitute a rich and novel source of natural antioxidants as food additives in food industry and that acetone 80% would be the most appropriate solvent for seed extraction.     

An invariant observer for a chemostat model

In this paper, we tackle the problem of designing an invariant observer for a chemostat model with adjustable and robust convergence. The main idea of the paper is to build a new class of observers for chemostat model using hidden symmetries. The effectiveness of the proposed observer is shown through simulations.     

Leveraging Multi-Instance RPL Routing Protocol to Enhance the Video Traffic Delivery in IoMT

Wireless Personal Communications - Nowadays, the massive proliferation of real-world multimedia devices has paved the way to the emergence of a new paradigm called the Internet of Multimedia Things...     

Combustion with mixed enrichment of oxygen and hydrogen in lean regime

A low global richness of combustion is interesting from an ecological and economic point of view as it helps to limit fuel consumption. In fact, the consequences of the combustion in poor mode are the appearance of local or global flame extinctions, energy loss by radiation and change in flame structure. The flammability limits of the diffusion methane flame can be resolved by the enrichment of the combustion air with oxygen or the use of the pure oxygen as oxidant as well as the addition to hydrogen in natural gas. Moreover, the use of oxygen and hydrogen as previously mentioned allow working in low ranges of richness while maintaining good flame stability. For a constant burner power of 15 kW, the reduction of the richness involves an increase in the oxidizer flow rate injected into the combustion reaction. In this present study, the variation of the richness, the fuel enrichment with hydrogen and the oxidant enrichment with oxygen are shown as major parameters where they have direct influences on the flow dynamic, the flame structure and the pollutant emissions.The Chemiluminescence of OH* radical and the PIV (Particle image velocimetry) are used in this work to characterize the flame structure, the stability and the dynamics of the flame. The measurement of pollutant emissions effected by a gas analyzer. The enrichment in oxygen and hydrogen provides a stable flame, which is well attached to the burner for the following richness values: 0.7, 0.8, 0.9 and 1. The reduction of the richness promotes the mixture quality of the reactants and leads a reduction in CO₂ and CO concentration. By contrast, the decrease of the richness supports the formation of NOx.     

Structural and optical studies of Yb^3＋, Er^3＋ and Er^3＋/Yb^3＋ co-doped phosphate glasses

Phosphate glass samples with various Yb2O3 and Er2O3 contents were synthesized by the conventional melt quenching technique and characterized by X-ray diffraction,IR absorption spectroscopy and Raman scattering spectroscopy.The absorption,emission spectra and fluorescence decay studies were carried out both at low and room temperatures.Results showed the existence of several sites occupied by the rare earth ions in the phosphate glass.Up-conversion and cooperative fluorescence were also discussed.     

Total Phenolics, Flavonoids, and Antioxidant Activity of Sage (Salvia officinalis L.) Plants as Affected by Different Drying Methods

In the current study, we determined the effects of seven drying methods on total phenolics, flavonoids, individual phenolics, and antioxidant activity of the methanol extract of Salvia officinalis L. As compared with total phenolic content (TPC) of fresh plants, results showed that the highest TPC was recorded in plants dried by microwave (MW) at a power of 800 W/30 g of fresh plant and was 4.2 times higher than that of fresh plants whereas the lowest content was found in the case of plants dried by far-infrared (FIR) at 45 °C. The analysis of the different extracts by RP-HPLC showed a predominance of phenolic acids particularly in fresh plants and those dried by MW (600 W/30 g of fresh plant) whereas flavonoids predominate in the case of plants dried by FIR (65 °C). The assessment of the radical scavenging activity (RSA) against the stable radical 1,1-diphenyl-1-picrylhydrazyl (DPPH) showed an increase in the scavenging effect particularly in MW (800 W/30 g of fresh plant) dried plants with an IC50?=?13.49 μg ml^?1 (IC50 is the concentration required to cause 50 % DPPH inhibition). The complementary assessment of the RSA using the β-carotene/linoleic acid system showed an increase of this activity for all extracts and particularly for the extract derived from MW (600 W/30 g of fresh plant) dried plants as compared to fresh ones. Finally, all the plant extracts showed moderate reducing power as assessed by the ferric-reducing antioxidant potential. These results suggested that MW drying could be applied to retain phenolic contents and to enhance antioxidant activity of sage plant materials.     

Effects of hydrogen addition and Carbone dioxide dilution on the velocity field in non reacting and reacting flows

The evolution of anti-pollution standards and the optimization of combustion efficiency push the development of new fuels with high energy efficiency. It is necessary to develop new alternative fuel to improve the efficiency of conventional systems, reduce emissions (NO_x, SO_x, soot particles) and recover for its materials. A new fuel called bio-hythane, a mixture of natural gas up to 20% hydrogen and up to 50% Carbone dioxide, from the recovery of the waste from households and agriculture, via suitable digesters provides a source of renewable energy and usable, is a very interesting solution to improve emission standards and optimization of the combustion chambers.