Towards more reliable and secure source routing in mobile ad hoc and sensor networks

Routing protocols in mobile ad hoc and sensor networks discover a multi-hop route between source and destination nodes. A highly reliable path is an important component for enhancing the security of communication. This paper presents RAS: a Reliable routing protocol for enhanced reliability and security of communication in mobile Ad hoc and Sensor networks. Enhanced reliability and security are achieved by the maintenance of a reliability factor by the nodes, which is increased when nodes participate successfully in data transmissions. This is determined through the use of positive and passive acknowledgements. Additional optimizations are included in order to increase the efficiency and performance of the network. Simulation experiments are performed in order to verify the operation of the proposed protocol and evaluate its performance. The results show an improvement in the reliability of the discovered path with the proper choice of certain important reliability parameters.     

Combinations of organic and inorganic wastes for brick production

A mixture of different types of clay was blended with rice straw (RS) and microcrystalline cellulose (MCC) in the presence or absence of cement kiln dust (CKD) to produce new types of brick. The ratios of RS and MCC were 0, 5, and 10% w/w in the absence of CKD while they were kept at 5% w/w in its presence. The samples produced were compared to “blended” bricks prepared using 10% w/w CKD. Samples were fired at temperatures up to 1000°C and their surface and composition studied using SEM and XRD. Moreover, the chemical and physical properties of prepared bricks were determined. Introducing RS reduced both strength and bulk density but increased porosity of prepared samples. The presence of MCC alone increased the compressive strength, while combining RS with CKD overcame the decrease in strength resulting from the presence of RS alone. This has enabled the production of light‐weight low‐cost bricks with a compressive strength close to nonblended bricks, especially at high firing temperature. POLYM. COMPOS., 35:174–179, 2014. © 2013 Society of Plastics Engineers     

Characterisation and phenolic profiles of two rare olive oils from southern Tunisia: Dhokar and Gemri‐Dhokar cultivars

BACKGROUND: The aim of this work was to study the chemical characteristics of two Tunisian cultivars, namely Dhokar and Gemri‐Dhokar, to analyse the fatty acids, sterols, triacylglycerols, triterpenic alcohols, and to determine the phenolic composition and oxidative stability. RESULTS: Among the rare varieties, Gemri‐Dhokar olive oil had the highest value of oleic acid (69.39%) whereas Dhokar oil was noteworthy for its lower content of phenolic compounds (94.56 mg kg^?1 gallic acid equivalents of oil) and presented the highest level of palmitic acid (19.37%). The main sterols found in all olive oil samples were β‐sitosterol and Δ5‐avenasterol, whereas cholesterol and 24‐methylenecholesterol were also found in all samples but in lower amounts. Two triterpenic dialcohols (erythrodiol and uvaol) were also detected and their content ranged from 1.45 to 2.30%, in Gemri‐Dhokar and Dhokar olive oil, respectively. Ten phenolic compounds were identified. In all samples, the main phenols found were oleuropein aglycon and pinoresinol. These phenolic compounds showed significant correlations with oxidative stability. CONCLUSION: The analytical parameters of two oils that were determined in this study were greatly influenced by genetic factors (cultivar). © 2012 Society of Chemical Industry     

Deterioration of a Tunisian coastal aquifer due to agricultural activities and possible approaches for better water management

The purpose of this study is to provide a better understanding of the impact of agricultural activities on groundwater quality in a semi‐arid coastal environment (Korba, Tunisia). Impacts have been assessed through groundwater samples that were analysed for a range of chemical and biological parameters. Results indicate that groundwater overexploitation for irrigation and fertiliser use have affected the quality of the groundwater not only by direct contamination but also seawater intrusion. The implementation of appropriate regulatory and economic instruments to foster sustainable practices in the agricultural sector have been analysed within the framework of the EC (European Community) FP6 (funding program 6) INECO (Institutional and Economic Instruments for Sustainable Water Management in the Mediterranean Region) Project. Through stakeholder involvement processes, the project analysed issues relating to the regulation and control of groundwater abstractions, the promotion of wastewater reuse, efficiency improvements in irrigation water use, as well as instruments to strengthen the socioeconomic and institutional environment towards better managing and conserving available groundwater resources.     

Phased arrays in communication system based on Taguchi‐neural networks

Phased antenna array design is one of the most important electromagnetic optimization problems. This research combined the Taguchi method and artificial intelligence methods, used them as the prediction tool in designing parameters for the communication system, and then constructed a set of the optimal parameter analysis flow and steps. In this paper, we present an application of artificial neural networks in the electromagnetic domain. We particularly look at the multilayer perceptron network, which has been the most used of artificial neural networks architectures both in the electromagnetic domain and in the Taguchi optimization technique and describes the Taguchi method to optimize the excitations elements of the linear array to produce a radiation pattern with minimum side lobe level and null placement control. This paper investigates how the implementation of the signal processing in hardware affects the performance of the adaptive array antenna. The investigation is confined to uplink or receive antenna array only. Results of a prototype of antenna array with feeding values designed using the proposed techniques are also presented. Copyright © 2013 John Wiley & Sons, Ltd.     

Modeling coupled heat transfer and air flow in a partitioned building with a zonal model: Application to the winter thermal comfort

The assessment of building thermal comfort quality in the Mediterranean context necessitates detailed information concerning local air speed and temperature inside the space. We have extended the three-dimensional zonal model ZAER (Zonal AERial model) to enable predictions of air flow pattern and thermal distributions between and within rooms. Numerical simulations from the new program have been compared with data obtained from measurements on the experimental cell Minibat (CETHIL, INSA Lyon laboratory) and with the prediction of another zonal model as well as a computational fluid dynamics (CFD) tool. The comparison indicates that this new program is an effective model for predicting air flow and temperature distribution in a partitioned building. By coupling ZAER with a thermal comfort model, we study the influence of a passive solar component belonging to a south-oriented room upon the winter thermal comfort of an unconditioned Tunisian dwelling. The obtained results show that this simulation tool has the potential to describe realistically the thermal comfort within a dwelling, and that a Trombe wall can be a useful heating component to improve thermal winter comfort in the Tunisian context, even in another room.     

Measuring changes in radio-frequency dielectric properties of chicken meat during storage

Changes in dielectric properties of stored chicken meat were tracked by using a radio-frequency dielectric spectroscopy method. For this purpose, the dielectric properties were measured with an open-ended coaxial-line probe and a vector network analyzer over a broad frequency range from 200 MHz to 20 GHz at 23 °C. Chicken meat samples were stored in a refrigerator for 8 days at 4 °C. Dielectric constant and loss factor were measured daily over that period. The dielectric constant decreased with frequency and storage duration with a slope change at about 4 GHz. The dielectric loss factor increased with storage duration for frequencies below 3 GHz and remained almost constant above that. The frequency dependence of the dielectric loss factor was dominated by ionic conduction in the lower frequency range and dipolar relaxation of water above 3 GHz. For frequencies below 3 GHz, both the dielectric loss factor and loss tangent increased linearly with storage duration. A three-dimensional representation of the dielectric loss factor as a function of storage duration and conductivity provided analytical expressions that can be used to track chicken meat aging from measurement of the dielectric properties at a single frequency.     

Nitric Oxide-Releasing Drug Glyceryl Trinitrate Targets JAK2/STAT3 Signaling,Migration and Invasion of Triple-Negative Breast Cancer Cells

Triple-negative breast cancer (TNBC) is a highly aggressive disease with invasive and metastasizing properties associated with a poor prognosis. The STAT3 signaling pathway has shown a pivotal role in cancer cell migration, invasion, metastasis and drug resistance of TNBC cells. IL-6 is a main upstream activator of the JAK2/STAT3 pathway. In the present study we examined the impact of the NO-donor glyceryl trinitrate (GTN) on the activation of the JAK2/STAT3 signaling pathway and subsequent migration, invasion and metastasis ability of TNBC cells through in vitro and in vivo experiments. We used a subtoxic dose of carboplatin and/or recombinant IL-6 to activate the JAK2/STAT3 signaling pathway and its functional outcomes. We found an inhibitory effect of GTN on the activation of the JAK2/STAT3 signaling, migration and invasion of TNBC cells. We discovered that GTN inhibits the activation of JAK2, the upstream activator of STAT3, and mediates the S-nitrosylation of JAK2. Finally, the effect of GTN (Nitronal) on lung metastasis was investigated to assess its antitumor activity in vivo.     

The synergistic combination of bis-silane and CeO2·ZrO2 nanoparticles on the electrochemical behaviour of galvanised steel in NaCl solutions

Bis-1,2-[triethoxysilylpropyl]tetrasulfide silane films containing CeO₂·ZrO₂ nanoparticles were deposited by dip-coating on galvanised steel substrates. The morphological features of the coated substrates were evaluated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The anti-corrosion performance of the modified silane film applied on galvanised steel substrates was studied by electrochemical impedance spectroscopy (EIS). The ability of nanoparticles to mitigate localized corrosion activity at artificially induced defects was investigated via the scanning vibrating electrode technique (SVET) and by the scanning ion-selective electrode technique (SIET). The results showed that the addition of nanoparticles provides good corrosion protection of the galvanised steel substrates pre-treated with the modified silane solutions. The corrosion activity was reduced by more than one order of magnitude. Complementary d.c. experiments, using zinc electrodes exposed to NaCl solutions containing the nanoparticles were also performed in order to better understand the role of the nanoparticles. An ennoblement of the corrosion potential and polarisation of the anodic reactions could be detected.