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.

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.