69 research outputs found
Entropy solutions for a traffic model with phase transitions
In this paper, we consider the two phases macroscopic traffic model
introduced in [P. Goatin, The Aw-Rascle vehicular traffic flow with phase
transitions, Mathematical and Computer Modeling 44 (2006) 287-303]. We first
apply the wave-front tracking method to prove existence and a priori bounds for
weak solutions. Then, in the case the characteristic field corresponding to the
free phase is linearly degenerate, we prove that the obtained weak solutions
are in fact entropy solutions \`a la Kruzhkov. The case of solutions attaining
values at the vacuum is considered. We also present an explicit numerical
example to describe some qualitative features of the solutions
Lack of BV bounds for approximate solutions to a two-phase transition model arising from vehicular traffic
We consider wave-front tracking approximate solutions to a two-phase transition model for vehicular traffic. We construct an explicit example showing that the total variation in space of the solution blows up in finite time even for an initial datum with bounded total variation
Characterization of Surface Water Quality Crossing Through Saids
Totals mesophile germs are also important notably at 2
Antifungal activity and evaluation of phenolics contents of dill Anethum graveolens L. extracts original from Algeria
188-194The present study aims to evaluate the antifungal activity of dill Anethum graveolens L. against two fungus pathogens of cereals in Algeria, where quantification of the secondary metabolite was investigated in different plant part (whole plant, seeds) and two soil conditions, one is non-salty and second salty soil.The polyphenols, flavonoids, and tannins ranged from 6.25±0.74 mg/g dried weight for the tannins to 167±9.47 mg/g dried weight for polyphenols. The antifungal activity of extracts was tested against Rhynchosporium secalis and Pyrenophora tritici-repentis. The mycelial growth of the tested fungi was also determined to evaluate the antifungal activity. The ideal concentration showed a significant reduction of the two tested fungi was found to be 10 mg/mL, and the mycelial growth inhibition was determined after 7 days of incubation. Observations on the mycelial growth after extracts treatment decreased growth diameters. The effect of the hexanoic extract on inhibition of P. tritici-repentis was 91.17% and the methanolic extract inhibited R. secalis at 93.42% as the highest inhibition rate. Thus, the extract of dill could be used to control fungus pathogens as a potential source of eco-friend fungicide
Antifungal activity and evaluation of phenolics contents of dill Anethum graveolens L. extracts original from Algeria
The present study aims to evaluate the antifungal activity of dill Anethum graveolens L. against two fungus pathogens of cereals in Algeria, where quantification of the secondary metabolite was investigated in different plant part (whole plant, seeds) and two soil conditions, one is non-salty and second salty soil.The polyphenols, flavonoids, and tannins ranged from 6.25±0.74 mg/g dried weight for the tannins to 167±9.47 mg/g dried weight for polyphenols. The antifungal activity of extracts was tested against Rhynchosporium secalis and Pyrenophora tritici-repentis. The mycelial growth of the tested fungi was also determined to evaluate the antifungal activity. The ideal concentration showed a significant reduction of the two tested fungi was found to be 10 mg/mL, and the mycelial growth inhibition was determined after 7 days of incubation. Observations on the mycelial growth after extracts treatment decreased growth diameters. The effect of the hexanoic extract on inhibition of P. tritici-repentis was 91.17% and the methanolic extract inhibited R. secalis at 93.42% as the highest inhibition rate. Thus, the extract of dill could be used to control fungus pathogens as a potential source of eco-friend fungicide
Pneumomédiastin tardif : complication rare du cathétérisme veineux jugulaire en hémodialyse
Le cathétérisme veineux central occupe une place considérable dans le traitement de l’insuffisance rénale terminale dans l’attente de la création d’une fistule artério-veineuse. Cependant il n’est pas dénué de complications. Nous rapportons un cas de pneumomédiastin tardif révélé par un œdème aigu du poumon chez une jeune patiente en hémodialyse, et nous discutons ses particularités
Évaluation de la résistance de dix porte-greffes d’agrumes résistants à la tristeza vis-à -vis du déficit hydrique
Introduction. In Morocco, citriculture faces up an increasing combination of biotic (Citrus tristeza virus (CTV) / Phytophthora spp.) and abiotic stresses (salinity, alkalinity and drought). Most of these constraints should be individually managed by adapted rootstock choice. However, the spread of CTV in the Mediterranean Basin will soon prohibit the use of the traditional sour orange rootstock, which currently provides sufficient tolerance to salinity and alkalinity. Therefore, the selection of new citrus rootstocks becomes urgent. Our study sought to investigate the effect of different water regimes on growth of ten citrus rootstocks: citrange Carrizo (France), citrange Carrizo (Morocco), citrange Troyer, citrange Yuma, Citrus volkameriana; two Poncirus trifoliata of different origins, citrumelo, Mand. Sunki x Poncirus trifoliata, and Poorman.
Materials and methods. For each rootstock, three months old seedlings were grown in plastic pots (0.5 L) in a greenhouse at El Menzeh, INRA, Morocco; they were subjected to three water regimes [(100%, 75% and 50%) moisture field capacity (Hcc) of the substrate]. The experiment was arranged in a split-plot design with three treatments. The morphological parameters measured were the plant height and dry and fresh matter accumulation. Physiological parameters studied were the Relative Water Content, transpiration rates and chlorophyll, soluble sugars and proline contents.
Results. The morphological and physiological parameters were affected by the intensity of water stress applied. However, rootstocks behaved differently regarding to this constraint. Water stress induced an increase in the proline and soluble sugars content in the rootstock leaves.
Conclusion. Water stress significantly affects the physiological and morphological characteristics of citrus rootstocks and, in conditions of extreme water deficit (50% Hcc), a differential behavior of the rootstock was found. Based on our results, the rootstocks Carrizo citrange (Morocco) and Poorman present the best overall ability to withstand water stress
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