An Energy-Aware Routing Protocol in Wireless Sensor Networks

The most important issue that must be solved in designing a data gathering algorithm for wireless sensor networks (WSNS) is how to save sensor node energy while meeting the needs of applications/users. In this paper, we propose a novel energy-aware routing protocol (EAP) for a long-lived sensor network. EAP achieves a good performance in terms of lifetime by minimizing energy consumption for in-network communications and balancing the energy load among all the nodes. EAP introduces a new clustering parameter for cluster head election, which can better handle the heterogeneous energy capacities. Furthermore, it also introduces a simple but efficient approach, namely, intra-cluster coverage to cope with the area coverage problem. We use a simple temperature sensing application to evaluate the performance of EAP and results show that our protocol significantly outperforms LEACH and HEED in terms of network lifetime and the amount of data gathered

QoS multicast tree construction in IP/DWDM optical internet by bio-inspired algorithms

Copyright @ Elsevier Ltd. All rights reserved.In this paper, two bio-inspired Quality of Service (QoS) multicast algorithms are proposed in IP over dense wavelength division multiplexing (DWDM) optical Internet. Given a QoS multicast request and the delay interval required by the application, both algorithms are able to find a flexible QoS-based cost suboptimal routing tree. They first construct the multicast trees based on ant colony optimization and artificial immune algorithm, respectively. Then a dedicated wavelength assignment algorithm is proposed to assign wavelengths to the trees aiming to minimize the delay of the wavelength conversion. In both algorithms, multicast routing and wavelength assignment are integrated into a single process. Therefore, they can find the multicast trees on which the least wavelength conversion delay is achieved. Load balance is also considered in both algorithms. Simulation results show that these two bio-inspired algorithms can construct high performance QoS routing trees for multicast applications in IP/DWDM optical Internet.This work was supported in part ny the Program for New Century Excellent Talents in University, the Engineering and Physical Sciences Research Council (EPSRC) of UK under Grant EP/E060722/1, the National Natural Science Foundation of China under Grant no. 60673159 and 70671020, the National High-Tech Reasearch and Development Plan of China under Grant no. 2007AA041201, and the Specialized Research Fund for the Doctoral Program of Higher Education under Grant no. 20070145017

Développement et application des systèmes microanalytiques pour la détection des polluants dans l'eau

Cette thèse concerne la détection des métaux lourds dans l environnement et en particulier dans les eaux de surface et les sous-produits de désinfection de l eau potable. Les deux catégories de contaminations ont des propriétés différentes de sorte que deux méthodes correspondantes ont été dévéloppées : l une est basée sur des capteurs moléculaires fluorescents mis en oeuvre dans un micro-dispositif, l autre est basée sur une détection électrochimique. Deux capteurs moléculaires fluorescents, Rhod-5N et DPPS-PEG, et plusieurs dispositifs microfluidiques ont été fabriqués et appliqués pour la détection des ions de métaux lourds, Cd (II) et Hg (II),dans les eaux de surface. Une nouveau circuit en PMMA est fabriqué par ablation laser femtoseconde et testé pour la détection de Cd2+ avec le Rhod-5N. De plus, des améliorations de la performance des circuits microfluidiques ont été faites. Une nouvelle méthode de détermination sensible de cinq acides haloacétiques (AHAs) dans les d'eaux a été développée. Elle est basée sur l'extraction électromembranaire (EME) avant électrophorèse capillaire avec détection de conductivité sans contact à couplage capacitif (CE-C4D).This thesis is aimed at environmental contaminations detection, mainly heavy metal ions in surface water and disinfection by-products (DBPs) in drinking water. The two categories of contaminations have different properties so that two correspondent methods were developed: one is based on fluorescent molecular sensors in a microfabricated device, the other one is based on conductive detection. Two fluorescent molecular sensors, Rhod-5N and DPPS-PEG, and several microfluidic devices were developed and applied for heavy metal ions Cd (II) and Hg (II) detection in surface water. A new microchip made of PMMA was fabricated by femtosecond laser ablation and tested for Cd (II) sensing based on a fluorescent molecular sensor Rhod-5N. Further more, some improvements of the performance of microfluidic chips were made. A novel method for sensitive determination of five priority haloacetic acids (HAAs) in water systems has been developed based on electromembrane extraction (EME) prior to capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4D).CACHAN-ENS (940162301) / SudocSudocFranceF

Impedance monitoring of cell adhesion, migration and differentiation for drug screening

Les mesures d'impédance électrique permettent de contrôler en temps réel des cultures cellulaires, ce qui constitue une approche utile à la fois pour la recherche fondamentale et les applications avancées. Dans ce travail de thèse, nous avons développé plusieurs types de dispositifs de suivi cellulaire par mesure d impédance, en utilisant différents types de substrats et de cellules. En premier lieu, on étudie l adhérence et la prolifération des cellules cultivées sur une membrane méso-poreuse (taille de pores bien inférieure à celle de la cellule); on montre ainsi une augmentation de l'impédance à travers la membrane avec le temps d incubation. En second lieu, on s'intéresse à la migration des cellules cultivées sur des membranes micro-poreuses (taille de pores comparable à celle de la cellule), indiquant la possibilité de mesure de variation d'impédance transwell à la résolution de la cellule unique. Enfin, un système de mesure d impédance à multiplexage est proposé pour observer la différenciation des cellules adipogéniques en milieu de culture avec ou sans médicaments. Ainsi, ce travail a permis de mettre au point plusieurs techniques de mesure d'impédance électrique pour des processus d adhésion, de migration et de différenciation cellulaire à haute résolution et/ou haut débit. En considérant d autres avantages tels que la miniaturisation, la facilité des mesures en temps réel, et leur aspect non-destructif, nous tenons à insister sur l étendue des possibilités de ces techniques pour des applications variées dans le domaine de la recherche biomédicale, du diagnostic, du criblage de nouveaux médicamentsPARIS-BIUSJ-Biologie recherche (751052107) / SudocSudocFranceF

Residue analysis of melamine in milk products by micellar electrokinetic capillary chromatography with amperometric detection

A high-performance micellar electrokinetic capillary chromatography with amperometric detection (MECC–AD) method for the fast determination of melamine (MM), occasionally used to increase the apparent protein content of milk products, has been developed. Method development involved optimisation of the working electrode, the running buffer system and acidity, the concentration of sodium dodecyl sulphate (SDS), the separation voltage, the applied potential and the sample injection time. Under the optimum conditions, MM can be well separated from its co-existing interferences in real-world samples within 9 min at the separation voltage of 20 kV in a 8 mmol/L SDS/20 mmol/L H₃BO₃–Na₂B₄O₇ running buffer (pH 7.4). Satisfactory recovery (83.3–105.5%), repeatability of the peak current (3.2%) and migration time (3.8%), and the limit of detection (2.1 × 10⁻⁶ g/mL) for the method were achieved. This proposed procedure has been successfully used for the determination of MM in milk products.5 page(s

Application of capillary electrophoresis to study phenolic profiles of honeybee-collected pollen

Honeybee-collected pollen is promoted as a health food with a wide range of nutritional and therapeutic properties. A high-performance capillary electrophoresis with amperometric detection method has been developed for the simultaneous determination of bioactive ingredients in 10 samples of honeybee-collected pollen in this work. Under the optimum conditions, 13 phenolic components can be well-separated or nearly baseline-separated (apigenin and vanillic acid peaks) within 29 min at the separation voltage of 14 kV in a 50 mM borax running buffer (pH 9.0), and adequate extraction was obtained with ethanol for the determination of the above 13 compounds. Recovery (94.1–104.0%), repeatability of the peak current (<5.4%), and detection limits (6.9 × 10⁻⁷−6.4 × 10⁻⁹ g mL⁻¹) for the method were evaluated. This procedure was successfully used for the analysis and comparison of the phenolic content of honeybee-collected pollen samples originating from different floral origins based on their electropherograms or “phenolic profiles”.6 page(s