A Dynamic Adaptation Mechanism for Traffic Conditions in Wireless Sensor Network

As overall network traffic pursue to expand, a lot of low-power medium access control protocols have been proposed to deal with burst traffic in wireless sensor network. Although most of them provide low throughput but do not well optimize the energy consumption. In this paper, we propose a new hybrid carrier sense multiple access with collision avoidance (CSMA/CA) and time division multiple access (TDMA) protocol that arranges nodes into two categories of priority according to their traffic rate and data transmission delay. Nodes that have continuous data should send its data during the contention free period, those one will be classified as low priority and its data will be scheduling using TDMA. Others nodes who have a random data should transmit it immediately during the contention access period (CAP) using a fuzzy logic algorithm, based on their queue length and implemented in the CSMA/CA algorithm. Therefore, the proposed scheme dynamically changes the CAP length to ensure that nodes can complete its transaction during the same super-frame. Simulation results are done using the network simulator tools (NS-2) and have improved good efficiency regarding the IEEE 802.15.4 standard. The mechanism has improved the energy consumption, minimised the packet loss probability, increased the throughput variation in the network and also minimised the average end to end delay.     

Characteristics and functional properties of gelatin from zebra blenny (Salaria basilisca) skin

Gelatin was extracted from alkali-pretreated skin of zebra blenny (Salaria basilisca) using commercial pepsin with a yield of 18 g/100 g of skin sample. The polypeptides pattern, gel strength, viscosity, textural parameters and functional properties of the zebra blenny skin gelatin (ZBSG) were investigated. Amino acid analysis revealed that ZBSG contained almost all essential amino acids, with glycine being the most predominant one. ZBSG was identified as a type I gelatin, containing α₁ and α₂-chains as the major constituents. Its gel strength and viscosity were 170.2 g and 5.95 cP, respectively. Fourier transformed infrared spectroscopy (FT-IR) spectra showed helical arrangements in its structure. Its solubility and functional properties were concentration-dependent. While foam expansion (FE) and foam stability (FS) increased with the increase of concentration, emulsifying activity index (EAI) and emulsion stability index (ESI) were noted to decrease. ZBSG also showed strong clarification ability particularly for apple juice, without affecting nutritional value.     

Bayesian np control charts with adaptive sample size for finite production runs

The design of a control chart requires the specification of three decision variables, namely the sample size, n, the sampling interval, h, and the action limit under which the process must be stopped for potential repair. In this paper, the Bayesian attribute control chart, namely the np chart for short run production, using a variable sample size is discussed. In a simulated experiment, optimal solutions of the static np chart, the basic Bayesian np chart, and the Bayesian scheme with adaptive sample size are presented. Results of the empirical study show that varying the sample size leads to more cost savings compared with the other two approaches. In order to detect how the input parameters affect decision variables, a regression analysis is conducted. It is obtained that the benefits of using the basic Bayesian np chart and the Bayesian chart with adaptive sample size instead of the static scheme are affected by the length of the production run. Copyright © 2008 John Wiley & Sons, Ltd.     

Smart Parking Reservation System Based on Distributed Multicriteria Approach

In metropolitan area, finding a parking space is a difficult task for drivers especially in rush hours. This causes waste of time and fuel and results in traffic congestion. We propose a smart parking system based on multi-agent approach to provide a real-time decision-aid for drivers by handling their preferences. The system ensures an online space allocation based on real-time information by optimizing drivers’ preferences with respect to operational constraints. The online allocation problem is considered as a multicriteria decision-aid problem for which we present a mathematical formulation: multicriteria parking reservation problem. The solution is an optimal compromise from the set of efficient solutions which is determined by means of a multicriteria ranking method ELECTRE III. An update of resource allocation is performed to avoid reservation conflict and to ensure constraints satisfaction. After the reservation process, the driver is assisted via a guidance module to reach the reserved place through the shortest path. Simulation results show the wide applicability of the approach in real cases.     

A Structural and Electronic Properties DFT Study of BaFe2As2 and Two Derived Substitution Compounds

In this work, we calculated the structural and electronic properties of a pnictide iron based superconductor in both orthorhombic (Fmmm) and tetragonal (4I/mmm) phases using density functional theory in the generalized gradient approximation (GGA). We used pseudopotential and all-electron DFT variants. We found that the calculated structures are in good agreement with the experimental and other theoretical calculations. Two substitution compounds issued from the original compound were studied by the same methods.     

Comparative fatty acid profiles in edible parts of wild scallops from the Tunisian coast

Muscle and gonad fatty acid compositions from the Pectinids: Pecten jacobaeus, Chlamysvaria and Flexopectenglaber, from the Tunisian coast, were analysed. The recorded main fatty acid components in both organs for the three species were C16:0, C18:0, C18:1, C20:5ω3 and C22:6ω3. Meanwhile, high proportions of EPA and DHA were recorded in the muscle of C. varia (10.1–20.4%), P. jacobaeus (7.68–14.9%), whereas the highest rates (8.98–7.78%) were recorded in gonad for F. glaber. Highest ω3/ω6 ratios were recorded in muscle and gonad of C. varia (9.01 and 7.72, respectively). In P. jacobaeus, the muscle and the gonad had similar nutritional values. Muscle of C. varia had a better fatty acid composition than had the gonad, whilst the gonad value was higher than the muscle in the case of F. glaber.     

Buckling analysis of a laminated composite plate with delaminations using the enhanced assumed strain solid shell element

The paper deals with the validation of a recently proposed hexahedral solid-shell finite element in the buckling analysis of a laminated composite plate with delaminations. The object is to study the buckling behavior of structures with delaminations using the enhanced assumed strain (EAS) solid shell element with 5, 7 and 9 parameters. The EAS three-dimensional finite element formulation presented in this paper is free from shear locking and leads to accurate results for distorted element shapes. The developed FE model is used to study the effects of some parameters in the buckling load, such as the stacking sequences, delamination size, aspect ratio, width-to-thickness ratio. The feasibility of the proposed method is confirmed by numerical examples. Results show that using hexahedral solid-shell finite element in the buckling analysis is more efficient than using the enhanced solid finite element.     

Decolourization of the reconstituted dye bath effluent by commercial laccase treatment: Optimization through response surface methodology

This paper aims to study the effect of temperature, pH and enzyme concentration on decolourization of separately two reactive textile dyes (Black Novacron R and Blue Bezaktiv S-GLD 150) used in reconstituted dye bath effluent (textile dye and auxiliary components) and in aqueous dye solutions (dye dissolved in deionised water) by a commercial laccase formulation (DeniLite^® IIS). The central composite design (CCD) matrix and response surface methodology (RSM) have been applied to design experiments for the evaluation of the interactive effects of the three most important operating variables: temperature ‘T’ (25–45 °C), pH (3.0–7.0), and enzyme concentration ‘EC’ (80–240 U/L) on the enzymatic decolourization of the different synthetic dyes solutions at initial dye concentration of 40 mg/L. The RSM indicated that the optimum parameter values were respectively for the reconstituted Black Novacron R and the Blue Bezaktiv S-GLD 150 effluents: T = 43 °C and 41.44 °C, pH 6 and 6.29, EC = 222 and 226.43 U/L. The maximum colour removal was about 98.9% at 593 nm and 79.9% at 400 nm for reconstituted Black Novacron R effluent and about 98.9% at 620 nm for reconstituted Blue Bezaktiv S-GLD 150 effluent. For aqueous dye solutions, RSM has shown that colour removal obtained were quite similar. However, the optimum parameters were different. Hence, enzyme concentration depends on the effluent component.     

Purification and incorporation of the black ink of cuttlefish Sepia officinalis in eye cosmetic products

Synthetic colours used in cosmetics are a point of concern, and biotechnology has, to a certain extent, helped to resolve this problem. The present study aimed to integrate dyes from a natural extract, the black ink of cuttlefish Sepia officinalis, after purification, in black eye make‐up products (mascara and eyeshadow). Analyses showed differences in the chemical composition of treated and untreated forms of sepia black ink. Indeed, remarkable reductions in total mineral load, water content and proteins (79.3, 58.22 and 44% respectively) were noted. Treated sepia black ink had a low content of analytes. Very satisfactory results were obtained in terms of the level of aspect, texture, colour and covering capacity of the formulated cosmetic products. Moreover, the addition of S. officinalis black ink to iron oxide and black bone dyes improved the level of colour, spread and covering capacity of mascara and eyeshadow.     

Seasonal Variation of the Chemical Content and Fatty Acid Composition of Mantle and Tentacle of Male and Female Sepia officinalis

The goal of this study was to evaluate the chemical composition and the fatty acid profile of mantle and tentacle of male and female Sepia officinalis, sampled at four seasons from the Mediterranean sea of Tunisia. S. officinalis were found to be rich in glycogen, protein and oil, and significant differences were observed between samples. The level of saturated fatty acid and unsaturated fatty acid showed significant variability among sex and during seasons. DHA and EPA, as polyunsaturated fatty acids, were the most abundant in all samples (14.8–27.8 % and 10.4–18.3 %, respectively). Oleic acid was the most abundant monounsaturated fatty acids (1.63–4.52 %). Σn3 and Σn6 was remarkably different between seasons and among sex. This study could be suitable for the development of reliable guide of fatty acid accumulation in cephalopod.