Détail de l'auteur
Auteur Azzedine Bellel |
Documents disponibles écrits par cet auteur (4)
Affiner la recherche Interroger des sources externesElaboration d’un capteur pour la détection des composés organiques volatils à base d’une microbalance à quartz / Ali Bougharouat
Titre : Elaboration d’un capteur pour la détection des composés organiques volatils à base d’une microbalance à quartz Type de document : texte imprimé Auteurs : Ali Bougharouat, Auteur ; Azzedine Bellel, Directeur de thèse Editeur : constantine [Algérie] : Université Constantine 1 Année de publication : 2013 Importance : 132 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles Langues : Français (fre) Catégories : Français - Anglais
ElectroniqueTags : Composes organiques volatils Capteurs chimiques et biochimiques microbalance à quartz Index. décimale : 621 Electronique Résumé :
The work presented in this thesis concerns the study of the effects of the low frequency plasma discharge parameters (discharge time, monomer total pressure, and the proportion of oxygen with the monomer) on the essential characteristics of the elaborated chemical sensor such as: sensitivity, selectivity, linearity, reversibility,response time and ageing. The analysis of sensor response in adsorption mode and desorption mode show a good reproducibility and reversibility. The study of the response and recovery time showed that these latter appeared
extremely short compared to those usually obtained with the chemical sensors base on the QCM. The study of the variation of the sensitivity with deposited layer thickness showed an increase in the sensitivity with increasing film thickness followed by a decrease for a thicker film. Physical and chemical analysis of the deposited films revealed that the increase in the film thickness induces a densification of the elaborate layers. In the case of elaborate sensitive layers with TEOS in mixture with oxygen, the characteristic curves of the sensor response showed a significant increase in the sensor sensitivity with the increase of oxygen content in the mixture, followed by a reduction for a film elaborated with a high proportion of oxygen. Beyond 50% of O2 in the mixture, the films deposited have an inorganic character with a composition of SiOx type, close to thermal silica structure (dense, more rigid and less permeable). The study of the reliability of the sensor shows that the sensors elaborated from organosilicon films have a reasonable stability. The theoretical study of the diffusion phenomenon of the organic molecules inside the deposited films revealed that the molecular weight and the molar volume of the molecules influence significantly the diffusion phenomenon of COV. The results also show that all types of VOC have diffusion coefficients of about D > 1.90 X 10-11 cm ² /s and their diffusion kinetics follow a Fickienne evolution.Diplôme : Doctorat en sciences En ligne : ../theses/electronique/BOU6339.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=6311 Elaboration d’un capteur pour la détection des composés organiques volatils à base d’une microbalance à quartz [texte imprimé] / Ali Bougharouat, Auteur ; Azzedine Bellel, Directeur de thèse . - constantine [Algérie] : Université Constantine 1, 2013 . - 132 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ElectroniqueTags : Composes organiques volatils Capteurs chimiques et biochimiques microbalance à quartz Index. décimale : 621 Electronique Résumé :
The work presented in this thesis concerns the study of the effects of the low frequency plasma discharge parameters (discharge time, monomer total pressure, and the proportion of oxygen with the monomer) on the essential characteristics of the elaborated chemical sensor such as: sensitivity, selectivity, linearity, reversibility,response time and ageing. The analysis of sensor response in adsorption mode and desorption mode show a good reproducibility and reversibility. The study of the response and recovery time showed that these latter appeared
extremely short compared to those usually obtained with the chemical sensors base on the QCM. The study of the variation of the sensitivity with deposited layer thickness showed an increase in the sensitivity with increasing film thickness followed by a decrease for a thicker film. Physical and chemical analysis of the deposited films revealed that the increase in the film thickness induces a densification of the elaborate layers. In the case of elaborate sensitive layers with TEOS in mixture with oxygen, the characteristic curves of the sensor response showed a significant increase in the sensor sensitivity with the increase of oxygen content in the mixture, followed by a reduction for a film elaborated with a high proportion of oxygen. Beyond 50% of O2 in the mixture, the films deposited have an inorganic character with a composition of SiOx type, close to thermal silica structure (dense, more rigid and less permeable). The study of the reliability of the sensor shows that the sensors elaborated from organosilicon films have a reasonable stability. The theoretical study of the diffusion phenomenon of the organic molecules inside the deposited films revealed that the molecular weight and the molar volume of the molecules influence significantly the diffusion phenomenon of COV. The results also show that all types of VOC have diffusion coefficients of about D > 1.90 X 10-11 cm ² /s and their diffusion kinetics follow a Fickienne evolution.Diplôme : Doctorat en sciences En ligne : ../theses/electronique/BOU6339.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=6311 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/6339 BOU/6339 Thèse Bibliothèque principale Thèses Disponible
Titre : Etude et caracterisation d’un capteur chimique a base de couches minces Type de document : texte imprimé Auteurs : Meriem Boutamine, Auteur ; Azzedine Bellel, Directeur de thèse Editeur : constantine [Algérie] : Université Constantine 1 Année de publication : 2014 Importance : 117 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ElectroniqueIndex. décimale : 621 Electronique Résumé : "Volatile organic compounds (VOCs) are found in ambient air due to human activities and natural sources. High concentration exposure to some VOCs over a short or long term may cause diseases or serious irreversible effect. VOCs do not only harm the human and survival health but also pollute the environment due to their contribution to stratospheric ozone depletion, tropospheric photochemical ozone formation and enhancement of the global green house effect. The identification and monitoring of VOCs have become serious tasks in many countries of the world and are important for the early control of environmental pollution. The analysis of gases represents one of the main objectives of current research in the sensor field. In this context, one widely investigated device is the quartz crystal microbalance (QCM), in which an increase of mass into the crystal electrode due to sorption of the analyte molecules can generates a shift of the resonance frequency (Δf) according to the well known Sauerbrey equation..
In this work, Hexamethyldisiloxane (HMDSO) thin films coated quartz crystal microbalance (QCM) electrodes have been characterized for the detection of volatile organic compounds (VOCs). The sensitive coatings were plasma polymerized in pure vapor of HMDSO and HMDSO/O2 mixture. The sensor sensitivity was evaluated by monitoring the frequency shift (Δf) of the coated QCM electrode exposed to different concentrations of VOCs vapors, such as ethanol, methanol, benzene and chloroform. The isotherm response characteristics showed good reproducibility and reversibility. For all types of analyte, Δf were found to be linearly correlated with the concentration of VOCs vapor. It was shown that it is possible to tune the chemical affinity of the sensor by changing the oxygen ratio in the deposition gas mixture. Contact angle measurements (CA), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to study surface wettability, chemical composition and surface morphology of the coated QCM electrodes. ATR-FTIR analysis showed the presence of methyl groups around 840 cm−1 due to Si–(CH3)3 rocking vibration making the elaborated sensor surface hydrophobic. When the coating is performed in HMDSO/O2 mixture, AFM and SEM images showed an increase in the effective specific surface area of the sensor due to the increase in surface roughness. Surface morphology combined with chemical composition significantly affects the sensitivity of the QCM-based sensor"
Diplôme : Doctorat En ligne : ../theses/electronique/BOU6576.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9636 Etude et caracterisation d’un capteur chimique a base de couches minces [texte imprimé] / Meriem Boutamine, Auteur ; Azzedine Bellel, Directeur de thèse . - constantine [Algérie] : Université Constantine 1, 2014 . - 117 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ElectroniqueIndex. décimale : 621 Electronique Résumé : "Volatile organic compounds (VOCs) are found in ambient air due to human activities and natural sources. High concentration exposure to some VOCs over a short or long term may cause diseases or serious irreversible effect. VOCs do not only harm the human and survival health but also pollute the environment due to their contribution to stratospheric ozone depletion, tropospheric photochemical ozone formation and enhancement of the global green house effect. The identification and monitoring of VOCs have become serious tasks in many countries of the world and are important for the early control of environmental pollution. The analysis of gases represents one of the main objectives of current research in the sensor field. In this context, one widely investigated device is the quartz crystal microbalance (QCM), in which an increase of mass into the crystal electrode due to sorption of the analyte molecules can generates a shift of the resonance frequency (Δf) according to the well known Sauerbrey equation..
In this work, Hexamethyldisiloxane (HMDSO) thin films coated quartz crystal microbalance (QCM) electrodes have been characterized for the detection of volatile organic compounds (VOCs). The sensitive coatings were plasma polymerized in pure vapor of HMDSO and HMDSO/O2 mixture. The sensor sensitivity was evaluated by monitoring the frequency shift (Δf) of the coated QCM electrode exposed to different concentrations of VOCs vapors, such as ethanol, methanol, benzene and chloroform. The isotherm response characteristics showed good reproducibility and reversibility. For all types of analyte, Δf were found to be linearly correlated with the concentration of VOCs vapor. It was shown that it is possible to tune the chemical affinity of the sensor by changing the oxygen ratio in the deposition gas mixture. Contact angle measurements (CA), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to study surface wettability, chemical composition and surface morphology of the coated QCM electrodes. ATR-FTIR analysis showed the presence of methyl groups around 840 cm−1 due to Si–(CH3)3 rocking vibration making the elaborated sensor surface hydrophobic. When the coating is performed in HMDSO/O2 mixture, AFM and SEM images showed an increase in the effective specific surface area of the sensor due to the increase in surface roughness. Surface morphology combined with chemical composition significantly affects the sensitivity of the QCM-based sensor"
Diplôme : Doctorat En ligne : ../theses/electronique/BOU6576.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9636 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/6576 BOU/6576 Thèse Bibliothèque principale Thèses Disponible
Titre : Evaluation de la concentration d'un composé dans un mélange gazeux par un nez électronique Type de document : texte imprimé Auteurs : Omar Cherif Lezzar, Auteur ; Azzedine Bellel, Directeur de thèse ; Khalifa Aguir, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2016 Importance : 125 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ElectroniqueTags : Multicapteurs Analyse multivariable Identification des COV Quantification
des mélanges PECVD Capteurs de gaz.
Multi sensors multivariate analysis Identification of COV Quantification of
mixtures Gas sensors.
مجسات متعددة التحلیل متعدد المتغیرات تحدید المركبات العضویة المتطایرة تحدید ا ة لكمي من أخلاط
منها ترسب البلازما أجهزة الاستشعار الغازIndex. décimale : 621 Electronique Résumé : The identification and monitoring of volatile organic compounds (VOCs) have gained an
increasing concern in recent years because of their harmful effects on humans and the
environment. This has greatly promoted the development of chemical sensors to discern these latters. The selective detection of volatile organic compounds by means of chemical sensors is one of the open challenges in chemical sensing. In practice, most chemical sensors suffer from cross-sensitivity problem. To overcome this drawback, the identification and quantification of volatile organic compounds (VOC) by using a non-selective sensor requires a combination of sensors, followed by pattern recognition methods. In this context, a device widely studied is the quartz crystal microbalance (QCM) Based on this concept, the QCM-based sensors coated with different monomers were deposited by the technique of plasma enhanced chemical vapor deposition. A brief summary on physico-chemical and morphological analysis of sensitive layers, with infrared spectroscopy (FTIR) and atomic force microscopy (AFM) is also presented. The sensor sensitivity was evaluated by recording the frequency shift of the quartz (∆f) when exposed to different concentrations of VOCs, such as; ethanol, benzene and chloroform and their binary mixture. This has allowed the creation of a database consisting of different fingerprints of VOCs and their mixtures with different combinations of QCM to evaluate the performance of
each sensor combination by a qualitative and quantitative study using different methods of multivariate analysis, namely; hierarchical ascendant clustering (HAC), principal component analysis (PCA), factorial discriminate analysis (FDA), support vector machines (SVM) and artificial neural networks (ANN).
The results obtained showed that the combination of all the sensors as well as the
combination of sensors coated with different monomers are the most effective for the
identification and quantification of individual VOCs as well as the evaluation of a VOC in the mixtures, with different methods of multivariate analysis.Diplôme : Doctorat En ligne : ../theses/electronique/LEZ6867.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10181 Evaluation de la concentration d'un composé dans un mélange gazeux par un nez électronique [texte imprimé] / Omar Cherif Lezzar, Auteur ; Azzedine Bellel, Directeur de thèse ; Khalifa Aguir, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2016 . - 125 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ElectroniqueTags : Multicapteurs Analyse multivariable Identification des COV Quantification
des mélanges PECVD Capteurs de gaz.
Multi sensors multivariate analysis Identification of COV Quantification of
mixtures Gas sensors.
مجسات متعددة التحلیل متعدد المتغیرات تحدید المركبات العضویة المتطایرة تحدید ا ة لكمي من أخلاط
منها ترسب البلازما أجهزة الاستشعار الغازIndex. décimale : 621 Electronique Résumé : The identification and monitoring of volatile organic compounds (VOCs) have gained an
increasing concern in recent years because of their harmful effects on humans and the
environment. This has greatly promoted the development of chemical sensors to discern these latters. The selective detection of volatile organic compounds by means of chemical sensors is one of the open challenges in chemical sensing. In practice, most chemical sensors suffer from cross-sensitivity problem. To overcome this drawback, the identification and quantification of volatile organic compounds (VOC) by using a non-selective sensor requires a combination of sensors, followed by pattern recognition methods. In this context, a device widely studied is the quartz crystal microbalance (QCM) Based on this concept, the QCM-based sensors coated with different monomers were deposited by the technique of plasma enhanced chemical vapor deposition. A brief summary on physico-chemical and morphological analysis of sensitive layers, with infrared spectroscopy (FTIR) and atomic force microscopy (AFM) is also presented. The sensor sensitivity was evaluated by recording the frequency shift of the quartz (∆f) when exposed to different concentrations of VOCs, such as; ethanol, benzene and chloroform and their binary mixture. This has allowed the creation of a database consisting of different fingerprints of VOCs and their mixtures with different combinations of QCM to evaluate the performance of
each sensor combination by a qualitative and quantitative study using different methods of multivariate analysis, namely; hierarchical ascendant clustering (HAC), principal component analysis (PCA), factorial discriminate analysis (FDA), support vector machines (SVM) and artificial neural networks (ANN).
The results obtained showed that the combination of all the sensors as well as the
combination of sensors coated with different monomers are the most effective for the
identification and quantification of individual VOCs as well as the evaluation of a VOC in the mixtures, with different methods of multivariate analysis.Diplôme : Doctorat En ligne : ../theses/electronique/LEZ6867.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10181 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité LEZ/6867 LEZ/6867 Thèse Bibliothèque principale Thèses Disponible
Titre : Traitement de surfaces de polymères par décharge couronne et plasma Type de document : texte imprimé Auteurs : Azzedine Bellel ; Univ. de Constantine, Éditeur scientifique ; S. Sahèi, Directeur de thèse Année de publication : 2004 Importance : 125 f. Note générale : 01 Disponible à la salle de recherche 02 Disponibles au magazin de la bibliothèque centrale Langues : Français (fre) Catégories : Français - Anglais
ElectroniqueTags : Traitement de surface Polymères Décharge couronne et plasma Index. décimale : 621 Electronique Permalink : index.php?lvl=notice_display&id=2347 Traitement de surfaces de polymères par décharge couronne et plasma [texte imprimé] / Azzedine Bellel ; Univ. de Constantine, Éditeur scientifique ; S. Sahèi, Directeur de thèse . - 2004 . - 125 f.
01 Disponible à la salle de recherche 02 Disponibles au magazin de la bibliothèque centrale
Langues : Français (fre)
Catégories : Français - Anglais
ElectroniqueTags : Traitement de surface Polymères Décharge couronne et plasma Index. décimale : 621 Electronique Permalink : index.php?lvl=notice_display&id=2347 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEL/4098 BEL/4098 Thèse Bibliothèque principale Thèses Disponible
