Minimum Perimeter Coverage Set Based on Points of Tangency and Strong Barrier for an Extended WSN Lifetime

Wireless Personal Communications - The random deployment of sensors in the area of interest triggers several research issues. Among them, we can cite connectivity, localization and coverage. In...     

Experimental Investigation of the Parameters Influencing the Surface Defect Detection by Using the Critically Refracted Longitudinal Waves

Russian Journal of Nondestructive Testing - The aim of this work is the detection of surface defects by the refracted longitudinal wave and the study of the parameters that influence the use of...     

Dédoublement du tunnel d’Aokas (BEJAIA): geologie et caractérisation géotechnique du massif traversé. Stabilité de l’ouvrage

Underground work’s constructions and design techniques depend closely on the geological environment. The properties of the rock mass influence directly on the various steps of their realization so that geological and geotechnical studies become an absolute necessity to characterize the rock mass and to control the imposed constraints. At the end, we can conclude that the present work aims to define the geological and geotechnical conditions of the drilled rock mass; it consists mainly in determining the nature and the structure of the rock mass to cross, in addition to determining the rock mass stability and the reinforcement works. The route of the tunnel Aokas (Béjaïa) crosses a fractured limestone, where the karstification phenomenon is well developed and the best example being “fairy caves” contiguous on the old tunnel road in the NR 09. The two tunnel heads are located at the foot of two towering cliffs. All these characteristics make the tunnel in precarious potential stability. The detailed geological study allowed to determinate that the tunnel crosses through a karstified dolomitic limestone of the Babor’s chain of the lower Jurassic age, and a geotechnical study allowed a characterization of this rock mass regarding fracturing, mechanical and physical characteristics and led finally to a geomechanical classification. The stability of the tunnel is ensured by a strong support system.     

Feasibility study of hybrid fuel cell and geothermal heat pump used for air conditioning in Algeria

Hybrid Energy System (HES) is mainly based on proton exchange membrane fuel cell (PEMFC) technology, which is supplied by a fuel reforming process for hydrogen production, starting from natural gas. The exhaust heat from the PEMFC is evacuated to a thermal storage tank (TST) mixed with water provided by geothermal source, The bath (Hammam) Sidi Aïssa 47 °C, TST hot water maintained to 47 °C is used in a fan coil for canteen heating in Si Ben Salah School located in Saïda (NW of Algeria). Cooling is assured by the air conditioning sub-system made of a fan coil and heat pump using cool water tank. The experimental analysis of the air conditioning device is done for canteen application for cooling and heating modes. The feasibility study shows that using the geothermal sources located in Northern Algeria and low temperature PEMFC for air conditioning is a promising solution.     

Inhibition of Carbon Steel Corrosion in Neutral Calcareous Synthetic Water by Eruca sativa Extract

Protection of Metals and Physical Chemistry of Surfaces - Here, by various electrochemical and analytical techniques, we have examined whether Eruca sativa aqueous extract can inhibit the corrosion...     

Design,Synthesis and Discovery of N,N’-Carbazoyl-aryl-urea Inhibitors of Zika NS5 Methyltransferase and Virus Replication

The recent outbreaks of Zika virus (ZIKV) infection worldwide make the discovery of novel antivirals against flaviviruses a research priority. This work describes the identification of novel inhibitors of ZIKV through a structure-based virtual screening approach using the ZIKV NS5-MTase. A novel series of molecules with a carbazoyl-aryl-urea structure has been discovered and a library of analogues has been synthesized. The new compounds inhibit ZIKV MTase with IC₅₀ between 23–48 μM. In addition, carbazoyl-aryl-ureas also proved to inhibit ZIKV replication activity at micromolar concentration.     

Evolution of the properties of CuAlSe2 thin films with the oxygen content

CuAlSe₂ thin films have been synthesized by annealing, under argon flow, a multilayer structure of thin Cu, Al and Se layers sequentially deposited by evaporation under vacuum. It is shown that the oxygen content depends not only on the evaporation content but also on the argon flow. The properties of the thin films are modified by this oxygen percentage: when no more than 4–5 at % of oxygen is present in the films, their optical properties are very similar to that of single crystals. The inter-band transitions A, B, C typical of such chalcopyrite structure are clearly visible on the absorption spectra. The variation of the conductivity of these films in the high temperature domain is as that expected in CuAlSe₂, while in the low temperature, grain boundaries are dominant.     

The two-echelon multi-products location-routing problem with pickup and delivery: formulation and heuristic approaches

The two-echelon location-routing problem (LRP-2E) considers the first-level routes that serve from one depot a set of processing centres, which must be located and the second-level routes that serve customers from the opened processing centres. In this paper, we consider an extension of the LRP-2E, where the second-level routes include three constraints that have not been considered simultaneously in the location routing literature, namely multi-product, pickup and delivery, and the use of the processing centre as intermediate facility in the second-level routes. This new variant is named two-Echelon Multi-products Location-Routing problem with Pickup and Delivery (LRP-MPPD-2E). The objective of LRP-MPPD-2E is to minimise both the location and the routing costs, considering the new constraints. The first echelon deals with the selection of processing centres from a set of potential sites simultaneously with the construction of the first-level routes, such that each route starts from the main depot, visits the selected processing centres and returns to the main depot. The second echelon aims at assigning customers to the selected processing centres and defining the second-level routes. Each second-level route, starts at a processing centre, visits a set of customers, through one or several processing centres, and then returns to the first processing centre. We present a mixed-integer linear model for the problem and use a Cplex solver to solve small-scale instances. Furthermore, we propose non-trivial extensions of the nearest neighbour and insertion approaches. We also develop clustering-based approaches that have not been extensively investigated with regards to location routing. Computational experiments are conducted to evaluate and to compare the performances of the proposed approaches. The results confirm the effectiveness of clustering approaches.