Robust geocast routing protocols for safety and comfort applications in VANETs

Routing in cooperative vehicular networks is a challenging task because of high mobility of vehicles and difficulty of localization. In this paper, we study the geocast routing problem in Vehicular Ad‐hoc NETworks (VANETs), which aims at delivering data to a specific group of mobile vehicles identified by their geographical location. Although many geocast routing protocols have been proposed, only partial inherent constraints of VANETs (such as mobility, internal network fragmentation problem, external network fragmentation problem, and overload) are taken into account. Therefore, we propose two novel and robust geocast routing protocols: the first one, called Robust Geocast Routing Protocol for Safety Applications (RGRP‐SA), is dedicated to road safety applications, while the second, namely, Robust Geocast Routing Protocol for Comfort Applications (RGRP‐CA), is designed for comfort applications. Simulations conducted in NS‐2 demonstrate that our safety‐oriented RGRP‐SA protocol outperforms Inter‐Vehicle Geocast protocol and Mobicast Routing Protocol in VANETs by sending up to 25% more packets, cutting the end‐to‐end delay in half, and solving the internal network fragmentation problem. Besides, it is also shown that our comfort‐oriented RGRP‐CA protocol serves well comfort applications with only light overhead by solving internal and external network fragmentation problems and providing more reliable data delivery (with a 25% higher packet delivery ratio) and higher network throughput utilization in comparison with Mobicast with Carry‐and‐Forward protocol. Copyright © 2015 John Wiley & Sons, Ltd.     

Mechanical and thermal properties of compatibilized polypropylene reinforced by woven doum

In this work, the development and the mechanical characterization of a doum textile composite based on a polypropylene matrix were carried out. Mechanical and rheological tests were effectuated, to illustrate the effect of woven fibers on the mechanical and viscoelastic properties at 0°, 15°, 30°, and 45° directions. The woven fibers were treated and the matrix was melted to a coupling agent to assure compatibility between the fibers and the polymer. The composites with long fiber are generally used as film and the main properties is the tensile. In this study, our goal was to improve the tensile properties. Results have shown that tensile properties exhibited a significant increase when compared to the polypropylene. However, it was observed that the stress direction has no influence on the thermal properties of the composite. Also, this article evaluates models that predict the stiffness of the composites at different stress directions to be compared to the experiments. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4347–4356, 2013     

Deterrent and insecticidal properties of bean seed (Phaseolus vulgaris L.) whole meal or protein extract incorporated into the diet of Callosobruchus maculatus (F.) (Coleoptera: Bruchidae)

Callosobruchus maculatus, a pest that causes serious damage to chickpea Cicer arietinum, cannot develop in the seeds of Phaseolus or Vigna spp. which contain lectins. The insecticidal activity towards C. maculatus in these seeds is attributed both to lectins with specific affinity to N-acetylglucosamine, the major component of insect chitin, and to alpha-amylase inhibitors (lectin-like proteins). The insecticidal properties of bean meal or bean protein extracts from different sources towards different pest species are variable and need to be experimentally evaluated. The main objective of this study was to determine through a feeding trial on artificial chickpea seed the potential of bean seed meal from a wild bean Vigna caracalla, four varieties of Phaseolus vulgaris, and of a protein extract of P. vulgaris seed, to alter different life history traits of C. maculatus. The chickpea weevil was set up on artificial chickpea seeds containing different amounts of bean meal to observe the effects on female oviposition, percentage of development to adulthood and juvenile development time. These traits were combined in a composite index measuring the alteration of the multiplication rate of C. maculatus fed on artificial seed. The activity of lectin-like extracts was observed on chickpea artificial seed spiked with bean seed extract. Incorporation of bean flour at a rate of 10 and 20% in chickpea artificial seed significantly decreased C. maculatus female fecundity, percentage of adult emergence, and greatly increased the development time. Feeding trials with protein extracts of P. vulgaris reduced fecundity and survival of C. maculatus. Incorporation of 10% V. caracalla bean seed meal in chickpea artificial seed, reduced the multiplication potential of C. maculatus by over 90% showing that bean seed lectin extracts are worthy of further investigation for post-harvest infestation control.     

Modification of the molar anionic charge density of acetone–formaldehyde–sulfite dispersant to improve adsorption behavior and effectiveness in the presence of CaAMPS®‐co‐NNDMA cement fluid loss polymer

Sulfonated aldol polycondensates were synthesized from acetone, formaldehyde, and different amounts of sodium sulfite, resulting in polymers with varying degrees of sulfonation (DS). The anionic charge amount of these macromolecules measured by polyelectrolyte titration decreased with lower DS. The effectiveness of the acetone–formaldehyde–sulfite (AFS) polycondensates as cement dispersant was found to depend on the amount of polymer adsorbed on cement. AFS adsorption decreases with lower DS. Interaction and compatibility between AFS and CaAMPS®‐co‐NNDMA fluid loss additive was studied by formulating binary additive systems composed of one of the modified AFS polymers and CaAMPS‐co‐NNDMA. At high DS, AFS adsorbs strongly and prevents CaAMPS‐co‐NNDMA from adsorbing in sufficient amounts on the cement surface. The result is poor fluid loss control of the cement slurry. AFS polymers with lower DS, however, allow simultaneous adsorption of both polymers in sufficient quantities to provide good fluid loss control and low rheology at the same time. Thus, effectiveness of both additives was retained. Obviously, effectiveness of such multi‐admixture systems depends on the adjustment of the adsorption behavior of the individual components relative to each other. Molar anionic charge density of the polymers was found to be a major parameter influencing their relative adsorption behavior. The AFS polymer with DS = 0.2 possesses a molar anionic charge density comparable to CaAMPS‐co‐NNDMA. Thus, when admixtures with similar molar anionic charge densities are used, the performance of one component is not negatively influenced by the other. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Estimation robuste du canal non stationnaire en mode fdd de la norme utra

One of the most important problems in mobile communication happens when mobile stations are moving at high speed. In fact, we can consider that the movement of terminals can be viewed as a time variation of the channel between the mobile and the base station. In that way the received signal at the base station or at the terminal (if we consider the Uplink and the Dowlink) is corrupted by the fading phenomenon. In this paper, we will analyze this type of problems in the utra/fdd mode of the umts. The restitution of the data requires the evaluation of the channel features. We are interested to receivers for base station in the Uplink case. We will use a time-varying parameters linear model in order to depict the non-stationarities. The classical algorithms of channel equalization, based on the training sequence, suffer from the distortion effect caused by the traffic interferences. This leads to a big data deterioration at the receptor level. We propose in the paper an adaptive technique for channel estimation using Double Kaiman algorithm in order to limit the effect of these interferences. We will compare the obtained results with the classical algorithms in order to illustrate the efficiency of our algorithm.     

Isomerism as a remarkable tool for the design of new potentially bridging macrocycle ligands: Synthesis and characterization of the [Cu(4-L1)](NO3)2·2H2O polymeric chain (4-L1=mono-N (4-picolyl)cyclen)

A new coordination complex [Cu(4-L1)](NO₃)₂·2H₂O (1) based on the functionalized cyclen mono-N (4-picolyl)cyclen (4-L1) has been prepared and characterized by X-ray diffraction. The structure of 1 can be described as a monodimensional coordination polymer in which the macrocycle ligand acts as bridging ligand. Examination of the inter-chain distances revealed the presence of hydrogen bonds between oxygen atoms of the nitrate anions and the hydrogen atoms of two secondary amines of the macrocycle ligands, affording isolated “double-chain” units. The overall structure of 1 consists of alternating succession of cationic layers of infinite “double-chain” units and anionic nitrate-water H-bonded layers.     

A stated preference analysis comparing the Analytical Hierarchy Process versus Choice Experiments

Our paper compares individual preferences for attributes and levels of an agro-food product using two different methodologies. A key question is whether different results are obtained when asking consumers what they “prefer” versus what they would “buy”. Within this context, we compare empirical results obtained from Choice Experiments (CE) versus the Analytical Hierarchy Process (AHP) due to their capacity to simulate the “purchasing” and “theoretical” stated preferences, respectively. We utilize a survey of restaurateurs’ stated preferences to include rabbit meat in their menus in Catalonia (Spain) in this exploratory study. Results demonstrate similarities and differences in the stated preferences for attributes and attribute levels with a 55.6% coincidence in their ranking between methods. Utility variation between levels in both approaches follows a similar shape for two of the three analyzed attributes.     

The unusual electrical response in polyaniline-threonine composites

Polymer-amino acid composites are a new class of polymer materials with unusual electrical property. Novel polyaniline-threonine composites combining the synthesized polyaniline and proteinogenic amino acid threonine have been prepared. The samples were characterized by Fourier-transform infrared spectra, UV-vis absorption spectra and atomic force microscopy. The unusual electrical response was found from the d.c. conductivity measurement. The carboxyl group of the amino acid threonine played an important role in the electrical conductivity. Analysis of d.c. conductivity data revealed that in the temperature range of 300 K-200 K, the d.c. conductivity was governed by Mott's 3-dimensional variable range hopping.