Combining chemical with biological oxidation for efficient treatment of chloronitrobenzene in groundwater

2019 Fall.Includes bibliographical references.Chloronitrobenzene (CNB) is a chloronitroaromatic compound widely used in the synthetic production of pharmaceuticals, pesticides, dyes, lumber preservatives, and many other industrial products. CNB has been recognized as a toxic organic contaminant to humans and is recalcitrant to microbial biodegradation in anoxic environments. When receptors are threatened by CNB-contaminated groundwater, regulators may demand immediate remedial approaches, such as advanced oxidation processes (AOPs). While AOPs are effective for the removal of many organic contaminants from water, these techniques are often costly, especially when complete mineralization is the goal. In this study, it was hypothesized that chemical oxidation for the primary purpose of ring cleavage followed by biological oxidation of the generated intermediates is more cost-effective than relying on AOPs only for complete mineralization. Electrochemical oxidation via hydroxyl radicals was chosen as model AOP and performed at various applied potentials and for different treatment durations. Liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC/QToF-MS) revealed that the aromatic ring in CNB is rapidly hydroxylated and cleaved to form dicarboxylic products including muconic acid, succinic acid, malic acid, and maleic acid. Further electrochemical oxidation of these dicarboxylates was slower by about two orders of magnitude. To evaluate the universal biodegradability of the generated intermediates, the electrochemically oxidized samples of CNB were then exposed to a microbial culture enriched from a rhizosphere soil. Results showed that the dicarboxylic ring opening products biodegraded under anoxic conditions within 7 days while aromatic species including CNB, chloronitrophenol, chlorohydroquinone and dihydroxybenzoquinone persisted over 28 days of biological treatment. A comprehensive cost analysis considering both capital costs (electrodes) and operational costs (electric energy) revealed that the most efficient treatment strategy is to apply electrochemical oxidation at a low applied potential around 6 V until complete cleavage of the aromatic ring is achieved. Beyond that, advanced oxidation of the readily biodegradable ring cleavage products becomes uneconomical. Consequently, the coupling of chemical oxidation for persistent parent compounds with biodegradation of transformation intermediates is an efficient approach for the treatment of groundwater contaminated with CNB and likely other aromatic contaminants

Discrimination between Arabic and Latin from bilingual documents

2011 International Conference on Communications, Computing and Control Applications (CCCA)Comment: 5 page

Characterization of carbapenem resistant Acinetobacter baumannii isolated from intensive care units in two teaching hospitals from Algeria and Tunisia

Introduction: This study was conducted to identify the enzymatic mechanism of carbapenem resistance in A. baumannii isolated from intensive care units of 2 teaching hospitals (Charles Nicolle hospital of Tunis and University hospital of Annaba). Methods: Twenty seven non repetitive carbapenem-resistant A. baumannii were collected (7 strains in Algeria and 20 in Tunisia). Antibiotic susceptibility was performed by disk diffusion method. MICs were determined by agar dilution method. EDTA-disk synergy test was performed for metallo-β-lactamases (MBL) phenotypicdetection. Detection of blaOXA-23-like, blaOXA-24-like, blaOXA-51-like and blaOXA-58-like families was performed by PCR followed by sequencing. Geneticrelatedness between strains was investigated by pulsed-field gel electrophoresis (PFGE). Results: Strains were recovered especially from respiratory tract specimens (n=12) and blood (n=11). All strains were co-resistant to all β-lactams, gentamicin, amikacin and ciprofloxacin, but remainded susceptible to colistin. MBL production was negative for all isolates. blaOXA-51-like was detected in all strains and blaOXA-23-like in 23 strains. However, blaOXA-58-like and blaOXA-24-like were not found in any isolate. Six major PFGE patterns were found in the Tunisian isolates. However, the Algerian strains were clustered in one clone.Conclusion: This study shows a high distribution of blaOXA-23 in imipenem-resistant A. baumannii isolated in Tunisia and Algeria. It demonstrated the epidemic diffusion of this multidrug resistant pathogen. Thus, strengthening of prevention measures are required to control further spread of carbapenemases in the two countries.Key words: A. baumannii, Carbapenem resistance, OXA-23-like, Pulsed-field gel electrophoresi

Modèle perceptif neuronal à vision globale-locale pour la reconnaissance de mots manuscrits arabes.

Colloque avec actes et comité de lecture. internationale.International audienceNous proposons dans cet article un système de reconnaissance de mots manuscrit arabes basé sur les modèles perceptifs d'activation interactive et de vérification, définis par des psychologues. Le système proposé est basé sur un Réseau de Neurones faisant partie des systèmes Transparent (RNT). Il procède par une vision globale des caractéristiques structurelles apparentes durant la première phase de propagation et une vision locale par des Descripteurs de Fourier normalisés en phase de rétro-propagation (DF). L'avantage du système appelé RNT-DF, est qu'il ne nécessite pas d'étape d'apprentissage. Il se réfère à des descriptions standard de l'écriture imprimée aussi bien au niveau global (mot) qu'au niveau de la normalisation locale (lettres). Une évaluation expérimentale des deux visions est effectuée sur une base de données des montants littéraux de chèques et de noms de villes tunisiennes

Combination of Local and Global Vision Modelling for Arabic Handwritten Words Recognition

Colloque avec actes et comité de lecture. internationale.International audienceWe propose in this paper a recognition system of Arabic hand-written words issued from literal amounts of Arabic checks. This system is based on the concept of PERCEPTRO developed by M. Côté for Latin word recognition. It is a specific NN, named Transparent Neural Network (TNN), combining a global and a local vision modelling (GVM - LVM) of the word. In the forward propagation movement, the former (GVM) proposes a list of structural features characterising the presence of some letters in the word. GVM proposes a list of possible letters and words containing these characteristics. Then, in the back-propagation movement, these letters are confirmed or not according to their proximity with corresponding printed letters. The correspondence between the letter shapes and the corresponding printed letters is performed by LVM using the correspondence of their Fourier descriptors, playing the role of a letter shape normalizer

Local Normalization Towards Global Recognition of Arabic Handwritten Script

Colloque avec actes et comité de lecture. internationale.International audienceIn this paper we present a geometrical correction method of handwritten characters. This normalization method is based on Fourier coefficients of a chain-encoded contour. It is carried out in order to improve the rate and the performance of an Arabic handwritten word recognition system. The recognition is based on the global observation of apparent features associated to key-letters of the recognized word, followed by a succession of local observations of secondary features in the word. The global observation does not only try to detect key-word letters, but it also generates a set of characters giving some hints about the identity of the unknown letters present in the word image. The normalization stage leads back the features matching the letter hypothesis in order to increase the chance of recognizing the word presented to the system. Transformed parameters are the angular rotation of the first harmonic phasors and the magnitude of the semimajor axis associated to Fourier coefficients of the truncated approximation to a closed contour. Experimental tests help to evaluate distances between the normalized character and its reference

Caractérisation Elliptique par Coefficients de Fourier du Contour du Script Arabe en vue de la Normalisation des Caractères

Colloque avec actes et comité de lecture. internationale.International audienceUne méthode de correction géométrique des caractères arabesmanuscrits est présentée dans cet article. Cette méthode dite denormalisation est réalisée dans le cadre d'un système dereconnaissance de mots manuscrit basé sur une première observationglobale des caractéristiques apparentes du mot suivi d'une successiond'observations locales au niveau des caractères non détectésglobalement. Un sous-ensemble de caractères imprimés candidat estproposé par le système de reconnaissance. l'étape de normalisationconsiste à ramener les paramètres du caractère manuscrit ambigu à ceuxde chacun des caractères de référence proposés afin d'aider le systèmede reconnaissance à mieux décider sur l'identité du caractère nonreconnue globalement. Les paramètres transformés sont l'angled'inclinaison de l'ellipse associée au premier harmonique du contourdu caractère et la taille décrit par le module de l'axe principal decette ellipse. Des tests expérimentaux permettent d'évaluer ladistance entre l'image normalisée et celle de référenc

IFN/ENIT - database of handwritten Arabic words

ABSTRACT. In this paper we are presenting a new database with handwritten Arabic town/village names. For each name the ground truth information, e.g. the sequence of character shapes, some style information, and the baseline are coded. 411 writers filled forms with about 26400 names containing more than 210000 characters. The database is described in detail. It is designed for training and testing recognition systems for handwritten Arabic words. The IFN/ENIT-database is available for the purpose of research. RÉSUMÉ: Dans cet article on présente une novelle base de données, qui contient des noms manuscrits de villes/villages arabes. Pour chaque nom les informations de base, par exemple l'ordre des formes de caractère, les informations sur le style de l'écriture, et la ligne de base sont codées. 411 auteurs ont rempli des formulaires avec plus de 26400 noms contenant plus de 210 000 caractères. La base de données est décrite en détail, et elle est conçue pour la formation et l'essai des systèmes d'identification pour les mots arabes manuscrits. La base de données-IFN/ENIT est disponible pour la recherche