Three main contributions are presented in this paper. First, the septic quasi-interpolants are calculated with all their coefficients. Second, we explore the results to solve a generalized and broad class of Fredholm integral equations of the second kind. Finally, we present three degenerate kernel methods; the latter is a combination of the two previously established methods in the literature. Moreover, we provide a convergence analysis and we give new error bounds. Finally, we exhibit some numerical examples and compare them with previous results in the literature.
Many self-adaptation routing schemes have been proposed for sensor networks. The most relevant of them consider a hierarchical topology and aim to meet energy conservation and QoS requirements in a homogeneous environment. In such networks, one specific algorithm is commonly applied by all nodes inside clusters. Contrarily, in this paper, we propose a heterogeneous routing by applying different strategies according to specific parameters at the same time inside different clusters. Moreover, each cluster can adopt different strategies at different moments under different conditions. This approach leads to a new self-adaptation protocol based on heterogeneity of the routing process in a multi-hop clustering WSN. The proposal uses a set of mechanisms that have been adopted in well-known protocols (HEEP, APTEEN, LEACH, PEGASIS, etc.) taking into account their strengths and weaknesses. Simulations under NS2 show that our proposal, based on heterogeneous routing protocol, prolongs the network lifetime with different ratios compared to HEEP, PEGASIS and others.
Tin oxide SnO2 thin films were deposited by sol gel method on glass substrates. The as-deposited thin films were then annealed at 550 °C for different time durations (15, 30, 60 and 120 min). Structural and morphological investigations were carried out on all samples by X-ray diffraction method and atomic force microscopy while optical properties were obtained with UV–Visible spectrophotometer. XRD patterns reveals that the samples possess polycrystalline with rutile structure of SnO2 without any secondary phase. AFM image showed that SnO2 thin films having a smooth surface morphology. The optical properties in the visible range showed that the deposited layers have a high transmission factor. The optical band gap energy varies in the range of 3.61–3.73 eV. Finally, ultraviolet (UV) detection properties of samples as an active layer in UV photodetector devices were investigated. Current-voltage characteristics of the SnO2 thin films are performed under dark and light environment, which show low dark current of 22.9 nA with a linear behavior and high current ration > 104 under 2 V applied voltage and 120 min as annealing time. Whereas, high photocurrent is observed for samples annealing for 30 min. Moreover, the transient photoresponse of the fabricated device is reported under different annealing times.
Seawater intrusion into fresh water aquifers is due to natural processes or human activities, and consequently salinization results not only from the ground but also from irrigation water. In an attempt to evaluate the effect of seawater irrigation on seedling growth and germination, seeds of three leguminous crops (Pisum sativum, Cicer arietinum and Phaseolus vulgaris) were irrigated with Mediterranean seawater of different concentrations (0, 10, 30, 50 and 100%) for 8-day period. Various parameters such as germination kinetics, mean germination time, germination rate index, shoot and root length, fresh and dry weight and moisture content were analysed.
The results showed that these species were able to germinate at different salinity levels, except for 100% seawater which resulted in total inhibition of germination. Compared with control, seed germination in all species remained unaffected up to 30% of seawater treatments. Indeed, the final germination percentage was maintained between 90 and 100%. A solution of 50% seawater significantly reduced germination rate index and increased mean germination time. 10% of seawater increased shoot and root length in all species compared to the control. The saline conditions reduced the growth parameter such as fresh and dry shoot and root weights of the three-studied species. Shoot and root dry weight was stable by 10, 30 and 50% of seawater except for P. vulgaris seedlings. The decrease in moisture content begins from 30% of seawater solution compared to the control in P. sativum and C. arietinum seedlings. However, it was maintained stable for P. vulgaris compared to the control.
Acacia nilotica is a ligneous forage tree of the family of Fabaceae (Legumes). This tree has a great agro-forester, sylvo-pastoral and nutritional importance in the arid and semi-arid regions where the plants cover is in a permanent reduction. The first cause is the lack of reforestation project. In addition, the stage of germination for the legume trees meets the problem of the integumentary dormancy (vernalization) and the global warming which limits the germination and the establishment of an important plant population. The germination rate in the nature is only between 5 and 10% according to the forest departments. The effect of a chemical pretreatment to improve the germination was studied by analyzing 3 parameters (germination kinetics; MGT: germination mean time (days) and GRI: germination rate index) after 4 times of incubation (4, 8, 12 and 16 days) in Petri dishes.
The pretreatment consisted of immersion of the seeds in concentrated sulphuric acid (98%) for 7 durations: 0 (Control), 20, 40, 60, 80, 100 and 120 minutes. For all the A. nilotica seeds treated in this study, the increasing duration of the soaking in the sulphuric acid improved significantly (p < 0,001) the germination by reducing the MGT and by increasing the GRI. The best germination reached a rate of 95%, with a reduced MGT (1 day) and a high GRI (47,33±2,64) for 100 minutes of soaking in the sulphuric acid. However, the immersion during 120 min reduced the GRI to (26,5±1,9). Such a pretreatment of 100 min is thus recommended to increase the rate of germination of the acacia trees implanted by the forest services in Algeria.
The present paper concerns a computational study of a three-dimensional (3D) unit cells with identical spherical voids in a von Mises matrix. The objective is to estimate the effective plastic flow surface of 3D microstructures. The work originality is to deal with identical spherical overlapping voids, covering a wide range of stress triaxiality ratios. The effective plastic flow surface is computed for nine distinct loadings on four distinct microstructures. The result indicates that the classical Gurson–Tvergaard–Needleman (GTN) model obtained using the Fritzen et al.parameters, matches with our numerical simulations.