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Partager le résultat de cette recherche Interroger des sources externesElaboration des Couches minces du Semiconducteur ZnO dopées au Cobalt et étude de leurs propriétés structurales, optiques et électriques. / Ahmed Reda Khantoul
Titre : Elaboration des Couches minces du Semiconducteur ZnO dopées au Cobalt et étude de leurs propriétés structurales, optiques et électriques. Type de document : texte imprimé Auteurs : Ahmed Reda Khantoul, Auteur ; Miloud Seffari, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 108 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Oxyde de zinc Cobalt Couches minces Dip-Coating Sol-Gel DRX MEB AFM Raman UV-Visible photoluminescence Zinc oxide cobalt thin films SEM ????? ????? ?????? ???? ???????? ???????-??????? ????? ???? ?????? ??????? ?????? ?????????? ?????? ???? ????? ?????? ?????? ????? ?????? ??????? ?????? ?????? ??? ?????????-??????? ????? ?????? ?????? Index. décimale : 530 Physique Résumé : The present work consists in the elaboration and characterization of the undoped and cobalt-doped ZnO with different concentrations of cobalt (Co) (0.5, 1, 5 and 10% in weight) thin films in order to improve the structural, morphological, optical and electrical properties of ZnO. The samples were prepared using the Sol-Gel method and deposited on glass substrates by the Dip-coating ""Dipping-Drawing"" technique. Structural haracterization showed the formation of ZnO of hexagonal structure (wurtzite) with a preferential orientation according to plane (002) and made it possible to determine the nanometric size of the crystallites. The SEM and AFM images revealed the nanometric character of our layers. Raman scattering confirmed the results of the XRD, namely the formation of ZnO with an hexagonal structure (wurtzite). UV-visible spectroscopy has shown that our layers have a transparency, in the visible, which varies between 80 and 98%. It has shown also that the gap decreases with the increase in doping. The hotoluminescence of the films showed ultraviolet (UV) and visible emissions related to defects. The codoping of aluminum to cobalt allowed us also to improve the structural and optical properties.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/KHA7383.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=11033 Elaboration des Couches minces du Semiconducteur ZnO dopées au Cobalt et étude de leurs propriétés structurales, optiques et électriques. [texte imprimé] / Ahmed Reda Khantoul, Auteur ; Miloud Seffari, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2018 . - 108 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Oxyde de zinc Cobalt Couches minces Dip-Coating Sol-Gel DRX MEB AFM Raman UV-Visible photoluminescence Zinc oxide cobalt thin films SEM ????? ????? ?????? ???? ???????? ???????-??????? ????? ???? ?????? ??????? ?????? ?????????? ?????? ???? ????? ?????? ?????? ????? ?????? ??????? ?????? ?????? ??? ?????????-??????? ????? ?????? ?????? Index. décimale : 530 Physique Résumé : The present work consists in the elaboration and characterization of the undoped and cobalt-doped ZnO with different concentrations of cobalt (Co) (0.5, 1, 5 and 10% in weight) thin films in order to improve the structural, morphological, optical and electrical properties of ZnO. The samples were prepared using the Sol-Gel method and deposited on glass substrates by the Dip-coating ""Dipping-Drawing"" technique. Structural haracterization showed the formation of ZnO of hexagonal structure (wurtzite) with a preferential orientation according to plane (002) and made it possible to determine the nanometric size of the crystallites. The SEM and AFM images revealed the nanometric character of our layers. Raman scattering confirmed the results of the XRD, namely the formation of ZnO with an hexagonal structure (wurtzite). UV-visible spectroscopy has shown that our layers have a transparency, in the visible, which varies between 80 and 98%. It has shown also that the gap decreases with the increase in doping. The hotoluminescence of the films showed ultraviolet (UV) and visible emissions related to defects. The codoping of aluminum to cobalt allowed us also to improve the structural and optical properties.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/KHA7383.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=11033 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité KHA/7383 KHA/7383 Thèse Bibliothèque principale Thèses Disponible
Titre : Contribution a l'étude des procèdes électrochimiques d'adoucissement des eaux dures Type de document : texte imprimé Auteurs : Yasmina Boulahèib (Née Bendaoud), Auteur ; Samira Ghizellaoui, Directeur de thèse Editeur : Constantine : Université Mentouri Constantine Année de publication : 2015 Importance : 187 f. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Entartrage traitement chimique PCR chronoampérométrie impédancemétrie MEB KH2PO4 Polyphosphates HEDP Scaling chemical treatment chronoamperometry impedance SEM ???? ?????? ???????? ?????? ??????? ?????? ?????????????????? ?????? ????????? ???????? ????? Index. décimale : 540 Chimie et sciences connexes Résumé : Treating hard water has been interest from several works in order to reduce the adverse consequences of tartar. Hard water deposits form compact and adherent to the walls of pipes and industrial or domestic installations (GHIZELLAOUI, 2006).
Our study focuses on softening hard water Hamma having a hardness of 59°F and Negrine with a hardness of 56°F in the presence of KH2PO4, polyphosphates and HEDP.
The evaluation and the inhibition of scaling of hard waters of Hamma and Negrine were carried out by using four methods:
- The chemical method for evaluating the effective concentration of inhibitor to reduce the hardness of waters of Hamma and Negrine at temperature sources 30°C while maintaining a residual calcium concentration of 1 00 mg/L.
- The method of rapid precipitation controlled to track the phenomenon of germination growth during the formation of the deposit of calcium carbonate.
- The electrochemical method of accelerated scaling to assess the scaling power of raw waters of Hamma and Negrine by electrochemical way and in the presence of chemical inhibitors (KH2PO4, polyphosphates and HEDP );
- electrochemical method for measuring impedances of precipitated deposits metal deposit calcium carbonate
- electrolyte interface enables an overall assessment by means of the highfrequency resistance , adhesion and the importance of filing carbonate calcium ( Khalil et al.1993).
-The effect of inhibitors on the morphology and adhesion of the deposit of calcium carbonate was observed by the scanning electron microscope SEM and RX.
The application of chemical treatment of the waters of Hamma and Negrine at temperature of 30°C showed that partial inhibition of hardness requires addition of 2 mg/L of KH2PO4 for Hamma and 3 mg/L for Negrine. By against, the use of the polyphosphates inhibits scaling at a concentration of 10 mg/L for Hamma water and 5 mg/L for Negrine water.
The HEDP effect is at a concentration of 1 00 mg/L for Hamma and 50 mg/L for Negrine.
These values are reduced using the method of rapid controlled precipitation for each of the three inhibitors (0.1 mg/L KH2PO4, 0.01 mg/L Polyphosphates or 0.01 mg/L HEDP) for water of Hamma, and (0.5 mg/L KH2PO4, 1 mg/L Polyphosphates or 0.01 mg/L HEDP ) for water of Negrine.
The chronoamperometric study shows that the scaling time increases with the addition of (0.1 mg/L KH2PO4, 0.04 mg/L Polyphosphates or 0.005 mg/L HEDP ) for Hamma water and (0.5 mg/L KH2PO4, 0.25 mg/L Polyphosphtes or 10-5 mg/L HEDP) for Negrine water.
The impedance measurement obtained from the raw waters of Hamma and Negrine compared to treated waters shows a decrease in the amount of calcium carbonate scale as well as its adhesion by measuring high frequency resistors deposits from addition of (0.01 mg/L KH2PO4, 0.01 mg/L Polyphosphates or 0.005 mg/L HEDP) for Hamma also (0.5 mg/L KH2PO4, 0.05 mg/L Polyphosphates or 0.0075 mg/L HEDP) for Negrine.
Diplôme : Doctorat en sciences En ligne : ../theses/chimie/BOU6778.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9831 Contribution a l'étude des procèdes électrochimiques d'adoucissement des eaux dures [texte imprimé] / Yasmina Boulahèib (Née Bendaoud), Auteur ; Samira Ghizellaoui, Directeur de thèse . - Constantine : Université Mentouri Constantine, 2015 . - 187 f.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Entartrage traitement chimique PCR chronoampérométrie impédancemétrie MEB KH2PO4 Polyphosphates HEDP Scaling chemical treatment chronoamperometry impedance SEM ???? ?????? ???????? ?????? ??????? ?????? ?????????????????? ?????? ????????? ???????? ????? Index. décimale : 540 Chimie et sciences connexes Résumé : Treating hard water has been interest from several works in order to reduce the adverse consequences of tartar. Hard water deposits form compact and adherent to the walls of pipes and industrial or domestic installations (GHIZELLAOUI, 2006).
Our study focuses on softening hard water Hamma having a hardness of 59°F and Negrine with a hardness of 56°F in the presence of KH2PO4, polyphosphates and HEDP.
The evaluation and the inhibition of scaling of hard waters of Hamma and Negrine were carried out by using four methods:
- The chemical method for evaluating the effective concentration of inhibitor to reduce the hardness of waters of Hamma and Negrine at temperature sources 30°C while maintaining a residual calcium concentration of 1 00 mg/L.
- The method of rapid precipitation controlled to track the phenomenon of germination growth during the formation of the deposit of calcium carbonate.
- The electrochemical method of accelerated scaling to assess the scaling power of raw waters of Hamma and Negrine by electrochemical way and in the presence of chemical inhibitors (KH2PO4, polyphosphates and HEDP );
- electrochemical method for measuring impedances of precipitated deposits metal deposit calcium carbonate
- electrolyte interface enables an overall assessment by means of the highfrequency resistance , adhesion and the importance of filing carbonate calcium ( Khalil et al.1993).
-The effect of inhibitors on the morphology and adhesion of the deposit of calcium carbonate was observed by the scanning electron microscope SEM and RX.
The application of chemical treatment of the waters of Hamma and Negrine at temperature of 30°C showed that partial inhibition of hardness requires addition of 2 mg/L of KH2PO4 for Hamma and 3 mg/L for Negrine. By against, the use of the polyphosphates inhibits scaling at a concentration of 10 mg/L for Hamma water and 5 mg/L for Negrine water.
The HEDP effect is at a concentration of 1 00 mg/L for Hamma and 50 mg/L for Negrine.
These values are reduced using the method of rapid controlled precipitation for each of the three inhibitors (0.1 mg/L KH2PO4, 0.01 mg/L Polyphosphates or 0.01 mg/L HEDP) for water of Hamma, and (0.5 mg/L KH2PO4, 1 mg/L Polyphosphates or 0.01 mg/L HEDP ) for water of Negrine.
The chronoamperometric study shows that the scaling time increases with the addition of (0.1 mg/L KH2PO4, 0.04 mg/L Polyphosphates or 0.005 mg/L HEDP ) for Hamma water and (0.5 mg/L KH2PO4, 0.25 mg/L Polyphosphtes or 10-5 mg/L HEDP) for Negrine water.
The impedance measurement obtained from the raw waters of Hamma and Negrine compared to treated waters shows a decrease in the amount of calcium carbonate scale as well as its adhesion by measuring high frequency resistors deposits from addition of (0.01 mg/L KH2PO4, 0.01 mg/L Polyphosphates or 0.005 mg/L HEDP) for Hamma also (0.5 mg/L KH2PO4, 0.05 mg/L Polyphosphates or 0.0075 mg/L HEDP) for Negrine.
Diplôme : Doctorat en sciences En ligne : ../theses/chimie/BOU6778.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9831 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/6778 BOU/6778 Thèse Bibliothèque principale Thèses Disponible
Titre : Etude de l’effet de la composition d’une couche mince et de ses conditions d’élaboration par plasma froid à partir de vapeurs organosiliciées sur les propriétés de surface d’un film polymérique Type de document : texte imprimé Auteurs : Abdelouahab Nouicer Ilyès dit, Auteur ; Salah Sahli, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 159 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ElectroniqueTags : HMDSO Polyimide traitement de surface mouillabilité super-hydrophobie nanopoudre PECVD RCER FTIR MEB AFM surface treatment wettability super-hydrophobic nanopowder SEM ????????? ?????? ????? ????? ???????? ??????????? Index. décimale : 621 Electronique Résumé : Plasma polymerization of hexamethyldisiloxane (PPHMDSO) was used to deposit SiOxCyHz thin films on silicon and polyimide substrates, using low-frequency plasma and microwave plasma discharge at low pressure. The effects of plasma chamber pressure, oxygen rate in Ar/O2 mixture, treatment time and post-treatment on the films characteristics were studied.
The thickness, surface properties and chemical structure of the deposited thin films were analyzed using profilo-meter measurements, scanning electron microscopy (SEM), static contact angle and infrared spectroscopy (FTIR and FTIR-ATR). At low frequencies and for certain deposition parameters, nano-powders of different concentrations and sizes were
observed on the deposited thin films surface. The FTIR analysis revealed that the chemical formula of the deposited layers is close to SiOxCyHz one, with more organic character when chamber pressure and/or deposition time were increased. Water contact angle measurements show that the increase in the deposition pressure and deposition time leads to the growth on
the polyimide and silicon substrates of thin layers with super-hydrophobic surface due to the increase in the concentration of the nano-powders on the treated surfaces. Plasmas created in HMDSO vapours using a microwave frequency plasma in ECR reactor leads to the deposition of similar PPHMDSO thin layer on polyimide and silicon surfaces. A post-treatment of these
coating layers using a microwave plasma created in Ar/O2 mixtures shows that the increase of oxygen rate in this mixture and the increase in the post-treatment time induces a significant decrease of the contact angle because of a decrease in the layers roughness (revealed by AFM characterization) and mainly, because of a more surface oxidation of the thin layers (revealed by FTIR analyzes)
Diplôme : Doctorat en sciences En ligne : ../theses/electronique/NOU7147.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10456 Etude de l’effet de la composition d’une couche mince et de ses conditions d’élaboration par plasma froid à partir de vapeurs organosiliciées sur les propriétés de surface d’un film polymérique [texte imprimé] / Abdelouahab Nouicer Ilyès dit, Auteur ; Salah Sahli, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2017 . - 159 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ElectroniqueTags : HMDSO Polyimide traitement de surface mouillabilité super-hydrophobie nanopoudre PECVD RCER FTIR MEB AFM surface treatment wettability super-hydrophobic nanopowder SEM ????????? ?????? ????? ????? ???????? ??????????? Index. décimale : 621 Electronique Résumé : Plasma polymerization of hexamethyldisiloxane (PPHMDSO) was used to deposit SiOxCyHz thin films on silicon and polyimide substrates, using low-frequency plasma and microwave plasma discharge at low pressure. The effects of plasma chamber pressure, oxygen rate in Ar/O2 mixture, treatment time and post-treatment on the films characteristics were studied.
The thickness, surface properties and chemical structure of the deposited thin films were analyzed using profilo-meter measurements, scanning electron microscopy (SEM), static contact angle and infrared spectroscopy (FTIR and FTIR-ATR). At low frequencies and for certain deposition parameters, nano-powders of different concentrations and sizes were
observed on the deposited thin films surface. The FTIR analysis revealed that the chemical formula of the deposited layers is close to SiOxCyHz one, with more organic character when chamber pressure and/or deposition time were increased. Water contact angle measurements show that the increase in the deposition pressure and deposition time leads to the growth on
the polyimide and silicon substrates of thin layers with super-hydrophobic surface due to the increase in the concentration of the nano-powders on the treated surfaces. Plasmas created in HMDSO vapours using a microwave frequency plasma in ECR reactor leads to the deposition of similar PPHMDSO thin layer on polyimide and silicon surfaces. A post-treatment of these
coating layers using a microwave plasma created in Ar/O2 mixtures shows that the increase of oxygen rate in this mixture and the increase in the post-treatment time induces a significant decrease of the contact angle because of a decrease in the layers roughness (revealed by AFM characterization) and mainly, because of a more surface oxidation of the thin layers (revealed by FTIR analyzes)
Diplôme : Doctorat en sciences En ligne : ../theses/electronique/NOU7147.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10456 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité NOU/7147 NOU/7147 Thèse Bibliothèque principale Thèses Disponible
