Optical and electrical properties of novel peripherally tetra and mono -quinoleinoxy substituted metallophtalocyanines

Two new Zinc phtalocyanine, ZnPcR₁ and ZnPcR₄, with peripheral mono and tetra quinoleinoxy substituents of the phtalocyanine ring, were characterized to investigate their optical and electrical properties. The modification of the chemical structure allows the elongation of the π-conjugation, leading to an enhanced solubility as well as a broadening of the ZnPcR₁ and ZnPcR₄ absorption spectra. The UV–Visible absorption spectra show a typical behavior of phtalocyanine for the two π-conjugated systems with an optical band gap of 1.70 and 1.74 eV for ZnPcR₁ and ZnPcR₄ respectively and the Photoluminescence study exhibits a green emission for both compounds. The highest occupied molecular orbital and lowest unoccupied molecular orbital levels were estimated using cyclic voltammetry analysis and the calculated electrochemical gap was found to be equal to the optical one. Current–voltage characteristics and impedance spectroscopy measurements performed on sandwich structures ITO/phtalocyanine derivatives/Al are used to elucidate the conduction mechanisms. The static electrical characterizations showed a space charge limited conduction with exponential trap distribution at high applied bias voltage. The impedance spectra were discussed in terms of an equivalent circuit model designed as a parallel resistor R_p and capacitor C_p network in series with a resistor R_s. The evolution of the electrical parameters deduced from fitting of the experimental data is discussed. The conduction mechanism revealed by I–V characteristics is in agreement with the impedance spectroscopy results.     

Semi-heterarchical control of FMS: From theory to application

This paper presents both a model and a real implementation of a semi-heterarchical control system for flexible manufacturing systems (FMS). After presenting the concepts of heterarchical and semi-heterarchical control, a product-based control structure, composed of a dynamic allocation process (DAP) and a dynamic routing process (DRP), is proposed. Though the associated control processes (DAP and DRP) are hierarchically dependant, each is managed heterarchically, with no supervisor. The dynamic allocation algorithms are presented, and our highly distributed approach to routing control is then explained in detail. A real distributed application of the active entities and the control architecture was implemented in the AIP-PRIMECA pole at the University of Valenciennes, and this implementation is described in detail. A mixed-integer linear model of the FMS was used to compute lower bounds. The flexibility and robustness of our approach are highlighted through several real experiments.     

On the SAR change detection review and optimal decision

Change detection is the process of identifying differences in the state of an object or scene after the occurence of an event. In this paper, we will present several similarity measures for automatic synthetic aperture radar (SAR) change detection, which can be classified into two families: the first regroups the measures based on pixel radiometry and the second collects the detectors based on local statistics. This article details a judicious method for SAR image change detection using Dezert–Smarandache Theory (DSmT). On the one hand, a Rayleigh distribution function is used to characterize globally the radar texture data, which allows mass assignment through the Kullback–Leibler distance. On the other hand, local pixel measurements are introduced through the Rayleigh Distribution Ratio indicator to refine the mass attribution and take into account the context information. Finally, DSmT is carried out by comparing the modelling results between temporal images. This technique has been applied on both simulated and real data and allows very satisfactory change detection results.     

Preparation of a novel zwitterionic graphene oxide-based adsorbent to remove of heavy metal ions from water: Modeling and comparative studies

A novel zwitterionic graphene oxide-based adsorbent was first synthesized in a multistep procedure including the successive grafting of bis(2-pyridylmethyl)amino groups (BPED) and 1,3-propanesultone (PS) onto graphene oxide (GO) sheets. Then, the as-prepared materials were used as adsorbent for the removal of metal ions from aqueous solutions. The influence of solution pH, contact time, metal ion concentration, and temperature onto the adsorption capacity of the zwitterionic GO-BPED-PS adsorbent was investigated and compared with the GO-BPED adsorbent. In particular, it was shown that the maximum adsorption capacities of the GO-BPED-PS adsorbent were as high as 4.174 ± 0.098 mmol.g^?1 for the Ni(II) ions and 3.902 ± 0.092 mmol.g^?1 for the Co(II) ions under optimal experimental conditions (metal ion concentration = 250 mg.L^?1, pH = 7 and T = 293 K). In addition, the adsorption behaviors of Ni(II) and Co(II) ions onto both the GO-BPED and GO-BPED-PS adsorbents fitted well with a pseudo-second-order kinetic model and a Jossens isotherm model. Moreover, adsorption thermodynamics of Ni(II) and Co(II) ions have been studied at various temperatures and confirmed the exothermic adsorption nature of the adsorption process onto the GO-BPED-PS adsorbent. Furthermore, the zwitterionic GO-BPED-PS adsorbent retained good adsorption properties after recycling 18 times which is much better than the conventional adsorbents.     

Delay-dependent robust observer-based control for discrete-time uncertain singular systems with interval time-varying state delay

The problem of observer-based robust control design is studied for discrete-time singular systems with norm-bounded uncertainties and a time-varying delay. More precisely, a delay-dependent criterion is established that guarantees the admissibility of the considered systems, without resorting to its decomposition. Based on the proposed criterion and without the assumption that the considered systems are admissible, robust observer-based controllers are designed for discrete-time singular time-delay systems such that the closed-loop systems have the characteristics of regularity, causality and asymptotic stability. Seeking computational convenience, all the developed results are cast in the format of strict linear matrix inequalities (LMIs). Finally, some numerical examples are presented to show the feasibility of the proposed approach.     

Unknown inputs observer for a class of nonlinear uncertain systems: An LMI approach

This paper deals with the simultaneous estimation of states and unknown inputs for a class of Lipschitz nonlinear systems using only the measured outputs. The system is assumed to have bounded uncertainties that appear on both the state and output matrices. The observer design problem is formulated as a set of linear constraints which can be easily solved using linear matrix inequalities (LMI) technique. An application based on manipulator arm actuated by a direct current (DC) motor is presented to evaluate the performance of the proposed observer. The observer is applied to estimate both state and faults.     

Anterior sacral meningocele associated with lumbar spondylodiscitis: contribution of images

The use of fiber bronchoscopy (FBS) for early diagnosis of aspiration in patients with grave craniocerebral (CCI) and combined injury is analyzed. Aspiration is not always associated with a clear-cut clinical picture in this cohort of patients, and x-ray examination of thoracic organs during the first hours after the injury is ineffective. High diagnostic potentials of BFS and possibility of removing the contents from the tracheobronchial tree under visual control dictate this measure for all cases with grave CCI and combined injuries during the first hours of hospitalization.     

Chemical composition, cytotoxicity effect and antimicrobial activity of Ceratonia siliqua essential oil with preservative effects against Listeria inoculated in minced beef meat

The present study describes the phytochemical profile and the protective effects of Ceratonia siliqua pods essential oil (CsEO), a food and medicinal plant widely distributed in Tunisia. Twenty five different components were identified in the CsEO. Among them, the major detected components were: Nonadecane, Heneicosane , Naphthalene, 1,2-Benzenedicarboxylic acid dibutylester, Heptadecane, Hexadecanoic acid, Octadecanoic acid, 1,2-Benzenedicarboxylic acid, Phenyl ethyl tiglate, Eicosene, Farnesol 3, Camphor, Nerolidol and n-Eicosane. The antimicrobial activity of CsEO was evaluated against a panel of 13 bacteria and 8 fungal strains using agar diffusion and broth microdilution methods. Results have shown that CsEO exhibited moderate to strong antimicrobial activity against the tested species. In addition, the inhibitory effect of this CsEO was evaluated in vivo against a foodborne pathogens Listeria monocytogenes, experimentally inoculated in minced beef meat (2 × 10² CFU/g of meat) amended with different concentrations of the CsEO and stored at 7 °C for 10 days. The antibacterial activity of CsEO in minced beef meat was clearly evident and its presence led to a strong inhibitory effect against the pathogens at 7 °C. On the other hand, the cytotoxic effects of the essential oil against two tumoral human cell lines HeLa and MCF-7 were examined by MTT assay. The CsEO showed an inhibition of both cell lines with significantly stronger activity against HeLa cells. The IC₅₀ values were 210 and 800 μg/ml for HeLa and MCF-7 cells, respectively. Overall, results presented here suggest that the EO of C. siliqua possesses antimicrobial and cytotoxic properties, and is therefore a potential source of active ingredients for food and pharmaceutical industry.     

Implementation of ISO 22000 in cereal food industry “SMID” in Tunisia

Cereal products (flour and semolina) are of great importance in the Tunisian diet. Over one million tons of cereal (soft and hard wheat) are consumed a year. Bread, pasta and couscous are the main forms of cereal consumption providing more than 70% of dietary proteins. The SMID, a wheat grinding company has implemented the ISO 22000 system involving essentially the prerequisite programs (PRPs) and the HACCP principals. The objective of this study is to determine food safety practices and procedures related to the food safety management system (ISO 22000). The PRPs were identified to prepare for the HACCP.     

Electrochemical degradation of 4-chloroguaiacol for wastewater treatment using PbO2 anodes

Electrochemical oxidation of 4-chloroguaiacol (4-CG) at Nb/PbO(2) anodes was studied under different experimental conditions such as initial concentration of substrate, electrolysis time, temperature and pH. We measured the concentrations of 4-chlorocatechol (4-CC), 2-methoxyhydroquinone (2-MHQ), maleic acid (MA) and carbon dioxide as the main products. Black solid particles consisting mainly of polymers were formed during electrolysis. A mechanism of electrochemical oxidation of 4-CG was investigated. The oxidation of 4-CG can generally be described by simple pseudo first-order kinetics. The degradation of 4-CG was favoured at high temperature and lower initial concentration of 4-CG and low solution pH. However, the increase of temperature has not a significant effect on the mineralization of carboxylic acids. Moreover, these products required long electrolysis time.