Seed germination and morphophysiological characterization of three tomato (Lycopersicon Esculentum) varieties irrigated with treated wastewater

The ability to reuse treated wastewater (TWW) would be of significant benefit to agriculture whilst at the same time providing a valuable water resource. This study concerned the effects of three various levels of treated wastewater (0%, 50% and 100% TWW) on seed germination and plant development of three different varieties of tomato (Lycopersicon esculentum) (viz. Toufan, Heinz and Bouzina). Irrigation with TWW persisted 15 days for the germination stage and 120 days for the growth and development stage. A control plot irrigated with a pure water (groundwater) was also set up in order to compare the seeds and the plants response to different concentrations of irrigation water. The final germination was expressed as a percentage of the total number of seeds in each treatment. This study has demonstrated that treated wastewater improves the germination in Heinz variety and had no effect on both Toufan and Bouzina varieties whether it is pure or diluted by half. For the growth stage, the statistical analysis showed that the Toufan variety has tolerated successfully the TWW irrigation with its high and moderate concentrations, and this by analysing all the morphophysiological parameters studied in this work (leaves numbers, stem and root length and dry biomass, relative water content and rate water loss)

Effect of nitrogen fertilizer on growth, flowering, fruiting and nodulation of three varieties of common bean in the arid region of aïn naga (Biskra, Algeria)

Field experiments were conducted to investigate the response of common bean (Phaseolus vulgaris L.) to nitrogen fertilizer. The main factor included the fertilizer (Granular Urea 46% N), was made up of two levels: no fertilization (0 kg/plot: control) and fertilization (0.4 kg/plot), while the secondary factor was the variety (three varieties of common bean: Djedida, Nelson and Jalila). The experimental design was a randomized complete block design with split plot arrangement and replicated four times. The effect of fertilization was evaluated during two development stages (flowering and fruiting) for each variety and this on the total dry biomass, the length of the aerial and root parts, as well as on the number of secondary roots. On the other hand, the combined effect of fertilization and variety was studied on some yield parameters per plant, such as the number of flowers, pods, seeds and the harvest index. In addition, the number of nodules at the end of seed maturation was evaluated. The results indicated that the nitrogen fertilizer application significantly reduced the root length, the number of nodules and secondary roots in most of the common bean varieties. However, fertilizer application significantly increased dry matter in both flowering and fruiting stages, for the three studied varieties. Pod number per plant and seed yield was increased by the application of N fertilizer, depending on varieties and the parameters being measured. Djedida and Jalila varieties gave the best yield and can therefore be recommended to farmers. According to our results, the percentage of improvement by N fertilization on one parameter or another does not exceed an average of 20%, compared to the control. Indeed, the effect of fertilization is positive and seems to increase the harvest index by 18% in Djedida and by 20% in Jalila, compared to non-fertilized plants. Unfertilized plants of the variety Nelson showed the highest ability to nodulate

Observer-based stabilisation of linear systems with parameter uncertainties by using enhanced LMI conditions

International audienceThis paper deals with the problem of observer-based stabilisation for linear systems with structured norm-bounded parameter uncertainties. A new design methodology is established thanks to a judicious use of some mathematical artefacts such as the well-known Young inequality and various matrix decompositions. The proposed method allows one to compute simultaneously the observer and controller gains by solving a single bilinear matrix inequality (BMI), which becomes a linear matrix inequality (LMI) by freezing some scalars. Furthermore, we show that some existing and elegant results reported in the literature can be regarded as particular cases of the stability conditions presented here. Numerical examples and evaluations of the conservatism are provided to show the effectiveness of the proposed design methodology

Convex optimization approach to observer-based stabilization of linear systems with parameter uncertainties

International audienceIn this paper we investigate the design of observer-based controller for uncertain linear systems. On the basis of the approach using the Lyapunov theory jointly with linear matrix inequalities (LMIs), and by handling judiciously the Young relation, we derive new sufficient linear matrix inequality (LMI) conditions for the asymptotic stabilizability. The proposed method allows to compute simultaneously the observer and controller gains by solving only one LMI. The developed approach is then extended to both continuous-time systems with parameter uncertainties and their Euler approximation models. We show that our approach contains, as a particular solution, the elegant results established in [1]. A numerical example is provided to compare with respect to some existing methods

Output feedback control for a class of switching discrete-time linear systems

International audienceThis paper is concerned with the output feedback control of switching linear systems without knowledge of the current switching mode. An observer-based control scheme is proposed that is based on the cascade of a Luenberger observer to estimate the continuous state, a mode estimator, and a controller fed with the estimates of both continuous state variables and mode. Conditions for the stability of such a control scheme are presented in both a noise-free setting and a noisy one because of bounded disturbances. Linear matrix inequalities are used to express such conditions with a reduced conservativeness as compared with the results available in the current literature. The effectiveness of the proposed approach is shown by means of simulations

Output feedback control for discrete-time linear systems by using Luenberger observers under unknown switching

International audienceThis note deals with the problem of the design of observer-based controllers for linear switching systems without having at disposal the current knowledge of the switching mode. An estimate of switching mode is obtained by using a moving-horizon estimator and used in a output feedback scheme with a Luenberger observer and a controller fed with the state estimated by such an observer. Conditions for the stability of the proposed control scheme are presented that can be expressed in terms of linear matrix inequalities. Simulation results show the effectiveness of the approach as for both estimation method and stabilization capability

Serious central nervous system side effects of cephalosporins: A national analysis of serious reports registered in the French Pharmacovigilance Database

International audienceIntroduction.- Among antibiotics, Central Nervous System (CNS) adverse drug reactions (ADRs) are often under suspected and overlooked. Cephalosporins are an important cause of drug-induced CNS ADRs but the characteristics of such ADR have not been fully explored. We aimed to characterize the profile of cephalosporins serious CNS ADRs. Method: We performed an analysis of serious reports recorded in the French Pharmacovigilance database from 1987 to 2017. Results: A total of 511 serious ADRs reports was analyzed. Patients had a mean age of 67.1 years and were mainly men (52.5%), with a mean creatinine clearance of 32.9 ml/min. The most involved molecules were cefepime (33.1%), ceftriaxone (29.7%), ceftazidime (19.6%), cefotaxime (9%) and cefazoline (2.9%), mostly administered intravenously (87.3%). A CNS history was observed in 25% of the reports (n = 128). Patients exhibited encephalopathy (30.3%), confusional state (19.4%), convulsion (15.1%), myoclonia (9.4%), status epilepticus (9.2%), coma (6.3%) and hallucination (4.3%). The mean time of onset was 7.7 days and the mean duration was 6 days. Cephalosporin plasma levels were recorded for 153 patients (29.9%) and 107 were above the standards including 62 (57.9%) related to renal impairment. Electroencephalograms were performed in 38.2% (n = 195) of the patients and 81% (ri = 158) were abnormal. Conclusion: This study characterizes an off-target CNS ADRs of several cephalosporins. Ceftriaxone represented a large part of our reports after cefepime and it would be relevant to warn healthcare professionals. Investigations (EEG, though plasma levels and renal function) can be precious tools for clinicians to make a prompt diagnosis and improve patients' outcomes

Valorization of Algerian sand for photovoltaic application

Extracting quartz from sand, as well as extracting silicon from quartz requires knowledge of the physical and chemical properties of quartz found in the sand. In this work the chemical composition, the crystallographic phase, crystal system, space group, unit cell parameters, the absorption bands, the granulometric analysis and the microscopic observations of quartz in the sand from Mostaganem (Algeria) region have been carried out using X-ray fluorescence, X-ray diffraction, infrared spectroscopy, sifting, optical and scanning electron microscopy in order to determine the rate and the nature the crystallinity of its various components and to discover a layer rich in silica, containing a sufficient reserve to feed a unit manufacturing pure silicon starting from silica. The study is driven by current economic importance of the silicon application in the field of photovoltaic solar cells. The X-ray fluorescence indicates that Mostaganem sand has got a very good purity (99.5% silica). The crystallographic parameters of Mostaganem sand have been determined through analysis of X-ray diffraction. The following parameters were found, hexagonal crystal system, space group P3221, unit cell parameters: a=b=4.9030 Å, c=5.3999 Å. The infrared absorption spectrum of studied sand exhibits absorption bands characterizing the SiO₂ compound, due to Si-O-Si and Si-O aggregates and others. The granulometric analysis determines the percentage of the various fraction of the grain. The microscopy observation gives the shape of the grain. The results show finally that Mostaganem sand has got good proprieties for the photovoltaic application

New decentralized control design for interconnected nonlinear discrete-time systems with nonlinear interconnections

This paper deals with a new decentralizedobserver-based controller design method for nonlinear discretetimeinterconnected systems with nonlinear interconnections.Thanks to some algebraic transformations and the use of anew variant of Young’s inequality, an LMI-based approachis provided to compute the observer-based controller gainmatrices. Furthermore, the congruence principle is used undera judicious and new manner leading to include additional slackvariables and to cancel some bilinear matrix coupling. Theeffectiveness of proposed methodology is shown through anillustrative example

Observer-based control design via LMIs for a class of switched discrete-time linear systems with parameter uncertainties

This paper deals with observer-based controllerdesign method via Linear Matrix Inequalities (LMIs) for a classof switched discrete-time linear systems. The main contributionconsists in providing different scenarios of the use of Finsler’sLemma to reduce the conservatism of some previous resultsin the literature. Thanks to this scenarios and the use of someother new mathematical tools, one of the objectives of this paperis to open new research directions for other control designproblems. The validity and effectiveness of the proposed designmethodologies are shown through a numerical example