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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 أكسيد الزنك كوبالت أفلام رقيقة طلاء بالتراجع المحلول-الهلامي أطياف حيود الاشعة السينية المجهر الالكتروني الماسح مجهر القوة الذرية انتشار رامول الطيفي التحليل الطيفي للأشعة فوق البنفسجية-المرئية تقنية الفوتو ضوئيات 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 : 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 . - 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 أكسيد الزنك كوبالت أفلام رقيقة طلاء بالتراجع المحلول-الهلامي أطياف حيود الاشعة السينية المجهر الالكتروني الماسح مجهر القوة الذرية انتشار رامول الطيفي التحليل الطيفي للأشعة فوق البنفسجية-المرئية تقنية الفوتو ضوئيات 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 : 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 : Synthèse par Sol-gel et caractérisation structurale et optique de nano poudres de ZnO pures et dopées en Aluminium (0.1, 0.5 , 0.75 , 1 , 5 , 7,10,15 et 20 % at). Type de document : texte imprimé Auteurs : Fatima Mahcène, Auteur ; Abdelhamid Chari, Directeur de thèse Mention d'édition : 08/03/2021 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2021 Importance : 100 f. Format : 30 cm. Note générale : 1 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : physique: Sciences des matériaux Sciences des matériaux: Semi-conducteurs Infra Rouge MEB ZnO Al203 Infra Red Sol-gel SEM ZnAl2O4 اكسید الزنك اكسید الالمنیوم السول جال الاشعة تحت الحمراء طور السبینل Index. décimale : 530 Physique Résumé :
Nanomaterials present new physical properties which open up promising prospects in terms of application, whether in the field of magnetism, mechanics, catalysis or optics. This aroused our interest with, however, a certain demarcation from previous studies, almost all carried out on thin films of ZnO. The novelty is that our study focused on zinc oxide in the form of nanopowders, with the objective of developing and then investigating the structural and optical properties as well as the morphology of these nanopowders. For this we have developed nanopowders by chemical sol-gel method, these nanopowders and doped with different proportions of aluminum oxide and aluminum chlorine by diffusion method at calcination temperatures of 450, 500, 700,750 and 900 degrees
CelsiusThe investigation was carried out by: X-ray, SEM, UV-visible, and infrared diffraction The results showed that the powders have a hexagonal structure (würtzite) and are of nanometric arrangementSolid solutions in which no new phase appears at 450 and 500 ° C, and this at low dopent, either starting from the doping of 7 percent or more, and at temperatures of 750 and 900 degrees Celsius, it shows a new phase of the spinelInoculation of ZnO nanopowders with aluminum oxide or chlorine showed a decrease in grainsize with an increase in concentration during spiking, and an increase in the effect of calcination temperature a also showed an increase in grain size and a sharp increase in doping. A scanning electron microscope study showed that nanopowders have a spherical shape. Its size decreases with the increase in the doping rate of aluminum. UV-visible characterizations show that the doped ZnO powders show an absorption edge around 380 nm. An optical gap decreases when aluminum is added. In conclusion, the nanopowders prepared reveal a good structural quality and a functional and optical aptitude for the application of these powders in the optoelectronic field.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/MAH7733.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11566 Synthèse par Sol-gel et caractérisation structurale et optique de nano poudres de ZnO pures et dopées en Aluminium (0.1, 0.5 , 0.75 , 1 , 5 , 7,10,15 et 20 % at). [texte imprimé] / Fatima Mahcène, Auteur ; Abdelhamid Chari, Directeur de thèse . - 08/03/2021 . - جامعة الإخوة منتوري قسنطينة, 2021 . - 100 f. ; 30 cm.
1 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : physique: Sciences des matériaux Sciences des matériaux: Semi-conducteurs Infra Rouge MEB ZnO Al203 Infra Red Sol-gel SEM ZnAl2O4 اكسید الزنك اكسید الالمنیوم السول جال الاشعة تحت الحمراء طور السبینل Index. décimale : 530 Physique Résumé :
Nanomaterials present new physical properties which open up promising prospects in terms of application, whether in the field of magnetism, mechanics, catalysis or optics. This aroused our interest with, however, a certain demarcation from previous studies, almost all carried out on thin films of ZnO. The novelty is that our study focused on zinc oxide in the form of nanopowders, with the objective of developing and then investigating the structural and optical properties as well as the morphology of these nanopowders. For this we have developed nanopowders by chemical sol-gel method, these nanopowders and doped with different proportions of aluminum oxide and aluminum chlorine by diffusion method at calcination temperatures of 450, 500, 700,750 and 900 degrees
CelsiusThe investigation was carried out by: X-ray, SEM, UV-visible, and infrared diffraction The results showed that the powders have a hexagonal structure (würtzite) and are of nanometric arrangementSolid solutions in which no new phase appears at 450 and 500 ° C, and this at low dopent, either starting from the doping of 7 percent or more, and at temperatures of 750 and 900 degrees Celsius, it shows a new phase of the spinelInoculation of ZnO nanopowders with aluminum oxide or chlorine showed a decrease in grainsize with an increase in concentration during spiking, and an increase in the effect of calcination temperature a also showed an increase in grain size and a sharp increase in doping. A scanning electron microscope study showed that nanopowders have a spherical shape. Its size decreases with the increase in the doping rate of aluminum. UV-visible characterizations show that the doped ZnO powders show an absorption edge around 380 nm. An optical gap decreases when aluminum is added. In conclusion, the nanopowders prepared reveal a good structural quality and a functional and optical aptitude for the application of these powders in the optoelectronic field.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/MAH7733.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11566 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité MAH/7733 MAH/7733 Thèse Bibliothèque principale Thèses Disponible
Titre : Caractérisation du pouvoir entartrant des eaux dures et inhibition du tartre par voie électrochimique et chimique. Type de document : texte imprimé Auteurs : Rayane Menzri ép Louaira, Auteur ; Samira Ghizellaoui, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2019 Importance : 209 f. Format : 30 cm. Note générale : Doctorat 3éme CYCLE LMD.
2 copies imprimées disponiblesLangues : Français (fre) Catégories : Français - Anglais
ChimieTags : Chimie: Chimie Analytique et Environnement Carbonate de calcium Traitement antitartre MgCl2 RPI2000 (polyacrylate) RS1600 (vitamines B1 et B6) Chronoampérométrie Impédancemétrie Méthode chimique IR RX Raman MEB Antiscaling treatment RS1600 (vitamins B1 and B6) Chronoamperometry Impedancemetry Chemical method SEM كربونات الكالسيوم العلاج المضاد للتكلس التقنية الكهروكيميائية للتكلس السريع تقنية قياس المقاومة الأشعة تحت الحمراء الأشعة السينية رامان الطيفي الميكروسكوب الالكتروني للمسح
RS1600(فيتامينات B1 و B6)Index. décimale : 540 Chimie et sciences connexes Résumé :
The ground water Hamma rich in calcium and bicarbonate likely to deposit the tartar and
subsequently lead to the obstruction of the pipes and the seizing of the stopping devices in addition to the financial losses resulting therefrom. It is therefore necessary to optimise an antiscaling treatment in order to avoid the risk of formation of tartar deposits in the various installations, and to protect the equipment in contact with this water. Three chemical inhibitors were tested: MgCl2, polyacrylate, and RS1600. The latter is a new green inhibitor that would allow the formation of tartar to be delayed. It is a mixture of vitamins B1 and B6 with a percentage of 50 % for each. To optimise the effective concentration of each product, we used two electrochemical methods (chronoamperometry and impedance) and three chemical methods (rapid controlled precipitation, the technique of degassing CO2 by agitation and technique of CO2 degassing by nitrogen sparge) to identify the best inhibitor and the best method for optimizing antiscaling treatment by chemical inhibition. The results obtained showed that the method of precipitation of calcium carbonate by degassing CO2 by agitation is the most effective method because the coefficient of oversaturation that is reached is closer to the real case avoiding thereafter the overestimation of inhibitors. This study also showed that it is possible to classify the chemical inhibitors according to their efficacy against the formation of calcium carbonate. All methods used revealed that RPI2000 is the most effective inhibitor. IR, RX, Raman spectroscopy, and SEM indicate that the raw waters of Hamma give precipitates in the form of calcite (the most stable form), with the presence of a small amount of magnesian calcite and aragonite. In the presence of the three inhibitors, calcium carbonate changes morphology to other forms that do not exist in the deposit obtained from the raw water (vaterite and calcium carbonate monohydrate).
Note de contenu :
Annexes.Diplôme : Doctorat En ligne : ../theses/chimie/MEN7512.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11348 Caractérisation du pouvoir entartrant des eaux dures et inhibition du tartre par voie électrochimique et chimique. [texte imprimé] / Rayane Menzri ép Louaira, Auteur ; Samira Ghizellaoui, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2019 . - 209 f. ; 30 cm.
Doctorat 3éme CYCLE LMD.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Chimie: Chimie Analytique et Environnement Carbonate de calcium Traitement antitartre MgCl2 RPI2000 (polyacrylate) RS1600 (vitamines B1 et B6) Chronoampérométrie Impédancemétrie Méthode chimique IR RX Raman MEB Antiscaling treatment RS1600 (vitamins B1 and B6) Chronoamperometry Impedancemetry Chemical method SEM كربونات الكالسيوم العلاج المضاد للتكلس التقنية الكهروكيميائية للتكلس السريع تقنية قياس المقاومة الأشعة تحت الحمراء الأشعة السينية رامان الطيفي الميكروسكوب الالكتروني للمسح
RS1600(فيتامينات B1 و B6)Index. décimale : 540 Chimie et sciences connexes Résumé :
The ground water Hamma rich in calcium and bicarbonate likely to deposit the tartar and
subsequently lead to the obstruction of the pipes and the seizing of the stopping devices in addition to the financial losses resulting therefrom. It is therefore necessary to optimise an antiscaling treatment in order to avoid the risk of formation of tartar deposits in the various installations, and to protect the equipment in contact with this water. Three chemical inhibitors were tested: MgCl2, polyacrylate, and RS1600. The latter is a new green inhibitor that would allow the formation of tartar to be delayed. It is a mixture of vitamins B1 and B6 with a percentage of 50 % for each. To optimise the effective concentration of each product, we used two electrochemical methods (chronoamperometry and impedance) and three chemical methods (rapid controlled precipitation, the technique of degassing CO2 by agitation and technique of CO2 degassing by nitrogen sparge) to identify the best inhibitor and the best method for optimizing antiscaling treatment by chemical inhibition. The results obtained showed that the method of precipitation of calcium carbonate by degassing CO2 by agitation is the most effective method because the coefficient of oversaturation that is reached is closer to the real case avoiding thereafter the overestimation of inhibitors. This study also showed that it is possible to classify the chemical inhibitors according to their efficacy against the formation of calcium carbonate. All methods used revealed that RPI2000 is the most effective inhibitor. IR, RX, Raman spectroscopy, and SEM indicate that the raw waters of Hamma give precipitates in the form of calcite (the most stable form), with the presence of a small amount of magnesian calcite and aragonite. In the presence of the three inhibitors, calcium carbonate changes morphology to other forms that do not exist in the deposit obtained from the raw water (vaterite and calcium carbonate monohydrate).
Note de contenu :
Annexes.Diplôme : Doctorat En ligne : ../theses/chimie/MEN7512.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11348 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité MEN/7412 MEN/7412 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 تكلس معالجة كيميائية الترسب المراقب السريع الكرونوأمبيرومترية مقاومة ميكروسكوب الكتروني للمسح 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 : 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 تكلس معالجة كيميائية الترسب المراقب السريع الكرونوأمبيرومترية مقاومة ميكروسكوب الكتروني للمسح 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 : 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 : Criblage des souches d’actinobactéries pour leurs pouvoirs PGPR : Essais in vitro et in planta sur Solanum lycopersicum L., Triticum durum Desf., et Daucus carota L. Type de document : texte imprimé Auteurs : Rihab Djebaili, Auteur ; Mahmoud Kitouni, Directeur de thèse ; Maddalena Del Gallo, Directeur de thèse Mention d'édition : 11-11-2021 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2021 Importance : 244 f. Format : 30 cm. Note générale : Doctorat 3éme CYCLE LMD.
1 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Microbiologie: Microbiologie générale et appliquée PGPB actinomycètes solubilisation du phosphate acide indole-3-acétique acide cyanhydrique biofertilisant ACC désaminase blé dur stress salin halotolérance la lutte biologique pathogènes SEM filtrats de culture tomate carotte actinomycetes phosphatesolubilization indole-3-acetic acid hydrocyanic acid biofertilizer ACC deaminase durum wheat salt stress halotolerance biological control pathogens culture filtrates tomato carrot Index. décimale : 570 Sciences de la vie. Biologie Résumé : Abiotic stress due to climate change and phytopathogens attacks lead to several damages in agricultural crops. Excessive use of chemicals in agriculture causes environmental pollution and loss of agricultural lands with fertile soils. Plant growth-promoting bacteria (PGPB) are an alternative strategy for sustainable agriculture. Among PGPBs, actinomycetes have recently gained increasing attention for their ability to alleviate plant stress and improve agricultural productivity. This study aimed to select actinomycetes strains with plant growth promoting traits, their plantroots association capacities, and their biostimulating effects without and with salt stress as well as the biocontrol power against several fungal and bacterial plant pathogens. The strains were studied for their phosphate solubilization capacity, indole-3-acetic acid (IAA), hydrocyanic acid (HCN),
and ammonia (NH3) production, and several enzymatic activities. Bacteria-root associations were studied by scanning electron microscopy (SEM), and a greenhouse experiment was performed to assess the inoculation effects on Solanum lycopersiumL.. Likewise, these strains were tested for in vitro halotolerant ability by several PGP tests with different salt concentrations (i.e., 0, 0.25, 0.5, 0.75, 1, 1.25, and 1.5 M NaCl) and by a greenhouse experiment on Triticum durum. The presence of 1-aminocyclopropane-1-carboxylate deaminase activity was also studied. Moreover, the strains were screened for their in vitro biocontrol activity by soluble and volatile compounds production against the fungal strains Fusarium oxysporum f. sp. radicis-lycopersici (FORL) and Rhizoctonia solani (RHS). The post-interaction events fungus-PGPB were analyzed by scanning electron microscopy. The antibacterial activity was evaluated against Pseudomonassyringae, Pseudomonas corrugata, Pseudomonas syringaepv. actinidiae, and Pectobacteriumcarotovorum subsp. carotovorum. Strains showing good in vitro biological control activities were studied for their antifungal and antibacterial activity using the cell culture filtrate (CFS). The consortium of potent strain was applied on Solanum lycopersicum L. and Daucus carota L. for in planta biocontrol activity. Among sixty actinomycetes, fourteen strains exhibited plant growth promoting characteristics. These strains were able to solubilize the phosphate, produce ammonia, and showed several enzymatic activities at different rates. The scanning electron microscopy revealed a good in vitro plant root association and colonization abilities. The actinomycetes inoculation influenced positively the tomato growth parameters. These strains exhibited important in vitro PGP traits under different salt concentrations. Most strains (86%) had 1-aminocyclopropane-1-carboxylate deaminase activity with significant amounts of ketobutyric acid. In the greenhouse experiment, inoculation with actinomycetes strainsimproved the durum wheat morpho-biochemical parameters, which recorded a significantly higher content of chlorophyll and proline than those of uninoculated controls both under normal and stressed conditions. Strains H12 (Streptomyces albidoflavus) and H14 (Nocardiopsisaegyptica) showed good in vitro antifungal activity with diffusible and volatile compounds (inhibition up to 85%) and antibacterial activity (diameter of inhibition> 10 mm). SEM micrographs showed morphological deterioration of the fungal filaments and changes in their structures. The CFS of potent strains was also active in fungal and bacterial pathogens inhibition (minimum inhibitory concentration up to 0.2%). The consortium was also able to alleviate the infection symptoms and allow a normal growth of the infected plants compared to the control. The obtained results demonstrate the efficacy of halotolerant actinomycetes strains as a biofertilizer and biocontrol agent for plant diseases management and for the alleviation of negative effects of salt stress in plants.
Note de contenu : Annexes.
Diplôme : Doctorat En ligne : ../theses/biologie/DJE7836.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11668 Criblage des souches d’actinobactéries pour leurs pouvoirs PGPR : Essais in vitro et in planta sur Solanum lycopersicum L., Triticum durum Desf., et Daucus carota L. [texte imprimé] / Rihab Djebaili, Auteur ; Mahmoud Kitouni, Directeur de thèse ; Maddalena Del Gallo, Directeur de thèse . - 11-11-2021 . - جامعة الإخوة منتوري قسنطينة, 2021 . - 244 f. ; 30 cm.
Doctorat 3éme CYCLE LMD.
1 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Microbiologie: Microbiologie générale et appliquée PGPB actinomycètes solubilisation du phosphate acide indole-3-acétique acide cyanhydrique biofertilisant ACC désaminase blé dur stress salin halotolérance la lutte biologique pathogènes SEM filtrats de culture tomate carotte actinomycetes phosphatesolubilization indole-3-acetic acid hydrocyanic acid biofertilizer ACC deaminase durum wheat salt stress halotolerance biological control pathogens culture filtrates tomato carrot Index. décimale : 570 Sciences de la vie. Biologie Résumé : Abiotic stress due to climate change and phytopathogens attacks lead to several damages in agricultural crops. Excessive use of chemicals in agriculture causes environmental pollution and loss of agricultural lands with fertile soils. Plant growth-promoting bacteria (PGPB) are an alternative strategy for sustainable agriculture. Among PGPBs, actinomycetes have recently gained increasing attention for their ability to alleviate plant stress and improve agricultural productivity. This study aimed to select actinomycetes strains with plant growth promoting traits, their plantroots association capacities, and their biostimulating effects without and with salt stress as well as the biocontrol power against several fungal and bacterial plant pathogens. The strains were studied for their phosphate solubilization capacity, indole-3-acetic acid (IAA), hydrocyanic acid (HCN),
and ammonia (NH3) production, and several enzymatic activities. Bacteria-root associations were studied by scanning electron microscopy (SEM), and a greenhouse experiment was performed to assess the inoculation effects on Solanum lycopersiumL.. Likewise, these strains were tested for in vitro halotolerant ability by several PGP tests with different salt concentrations (i.e., 0, 0.25, 0.5, 0.75, 1, 1.25, and 1.5 M NaCl) and by a greenhouse experiment on Triticum durum. The presence of 1-aminocyclopropane-1-carboxylate deaminase activity was also studied. Moreover, the strains were screened for their in vitro biocontrol activity by soluble and volatile compounds production against the fungal strains Fusarium oxysporum f. sp. radicis-lycopersici (FORL) and Rhizoctonia solani (RHS). The post-interaction events fungus-PGPB were analyzed by scanning electron microscopy. The antibacterial activity was evaluated against Pseudomonassyringae, Pseudomonas corrugata, Pseudomonas syringaepv. actinidiae, and Pectobacteriumcarotovorum subsp. carotovorum. Strains showing good in vitro biological control activities were studied for their antifungal and antibacterial activity using the cell culture filtrate (CFS). The consortium of potent strain was applied on Solanum lycopersicum L. and Daucus carota L. for in planta biocontrol activity. Among sixty actinomycetes, fourteen strains exhibited plant growth promoting characteristics. These strains were able to solubilize the phosphate, produce ammonia, and showed several enzymatic activities at different rates. The scanning electron microscopy revealed a good in vitro plant root association and colonization abilities. The actinomycetes inoculation influenced positively the tomato growth parameters. These strains exhibited important in vitro PGP traits under different salt concentrations. Most strains (86%) had 1-aminocyclopropane-1-carboxylate deaminase activity with significant amounts of ketobutyric acid. In the greenhouse experiment, inoculation with actinomycetes strainsimproved the durum wheat morpho-biochemical parameters, which recorded a significantly higher content of chlorophyll and proline than those of uninoculated controls both under normal and stressed conditions. Strains H12 (Streptomyces albidoflavus) and H14 (Nocardiopsisaegyptica) showed good in vitro antifungal activity with diffusible and volatile compounds (inhibition up to 85%) and antibacterial activity (diameter of inhibition> 10 mm). SEM micrographs showed morphological deterioration of the fungal filaments and changes in their structures. The CFS of potent strains was also active in fungal and bacterial pathogens inhibition (minimum inhibitory concentration up to 0.2%). The consortium was also able to alleviate the infection symptoms and allow a normal growth of the infected plants compared to the control. The obtained results demonstrate the efficacy of halotolerant actinomycetes strains as a biofertilizer and biocontrol agent for plant diseases management and for the alleviation of negative effects of salt stress in plants.
Note de contenu : Annexes.
Diplôme : Doctorat En ligne : ../theses/biologie/DJE7836.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11668 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité DJE/7836 DJE/7836 Thèse Bibliothèque principale Thèses Disponible
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