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Partager le résultat de cette recherche Interroger des sources externesTrasferts électroniques entre l'oxyde de zinc et les molécules chimisorbées O2; H2O; H2 etCO / Michel Guelton
Titre : Trasferts électroniques entre l'oxyde de zinc et les molécules chimisorbées O2; H2O; H2 etCO : etude expérimentale (RPE, RMN , gravimétrie) .Etude théorique et discussion des mécanismes Type de document : texte imprimé Auteurs : Michel Guelton ; Université de Reims, Editeur scientifique ; J.P. Beaufils, Directeur de thèse Année de publication : 1976 Importance : 137 f. Note générale : 01Disponible au magazin de la B.U.C. Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Oxyde de zinc Molécules chimisorbées O2 , H2O , H2 et CO Index. décimale : 540 Chimie et sciences connexes Diplôme : Doctorat en sciences En ligne : ../theses/chimie/GUE490.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=3988 Trasferts électroniques entre l'oxyde de zinc et les molécules chimisorbées O2; H2O; H2 etCO : etude expérimentale (RPE, RMN , gravimétrie) .Etude théorique et discussion des mécanismes [texte imprimé] / Michel Guelton ; Université de Reims, Editeur scientifique ; J.P. Beaufils, Directeur de thèse . - 1976 . - 137 f.
01Disponible au magazin de la B.U.C.
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Oxyde de zinc Molécules chimisorbées O2 , H2O , H2 et CO Index. décimale : 540 Chimie et sciences connexes Diplôme : Doctorat en sciences En ligne : ../theses/chimie/GUE490.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=3988 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité GUE/490 GUE/490 Thèse Bibliothèque principale Thèses Disponible
Titre : دراسة الخصائص الفـيزيـائـية للبورسلان المحضر إنطلاقا من مواد أولية محلية Type de document : texte imprimé Auteurs : سعاد قصراني, Auteur ; عبد الحميد حرابي, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 141 ورقة. Format : 30 سم. Note générale : 2نسخ موجودة مكتبة المركزية
Langues : Arabe (ara) Catégories : Arabe
الفيزياءTags : Porcelain Zinc oxide Titanium oxide Mechanical properties dielectrical properties Porcelaine oxyde de zinc oxyde de titane propriétés mécaniques propriétés diéléctriques ????????? ????? ????? ????? ??????? ????? ????????? Index. décimale : 530 الفيزياء Résumé : The aim of this work is to prepared porcelain with high mechanical and dielectric properties by
using economical native raw materials without providing ideal high-cost conditions. The basic
porcelain composition was selected consisting of 30 wt% kaolin, 45 wt% potash-feldspar and 25
wt% quartz. It was prepared by sintering the mixture at different temperatures (1140–1260 °C).
The optimum sintering conditions gave a bulk higher density (2.41 g/cm3) and excellent
mechanical properties. The three point flexural strength, Vickers micro-hardness of porcelains
were 205 MPa and 6.8 GPa, respectively. Dielectric measurements have been carried out at 1
KHz from room temperature to 200 °C. The dielectric constant, dielectric loss tangent, and
resistivity of the porcelain sample sintered at 1160 °C were 25, 0.008 and 9 x 1013 .cm,
respectively. So these values reveal that the porcelain is a good insulator. The mechanical and
dielectric properties of porcelain are improved by addition of titanium oxide and zinc oxide. The
addition of titanium oxide improved both mechanical and dielectrical properties. The optimum
sintering conditions gave a higher bulk density (2.47 g.cm−3) and excellent mechanical
properties. The three point flexural strength (3PFS), Vickers micro hardness of samples
containing 5 wt TiO2 and sintered at 1160 °C were 238 MPa, 12.3 GPa , respectively. The
dielectric constant, dielectric loss tangent of samples containing 5 wt TiO2 sintered at 1160 °C
for 2 h were: 31,0.005, respectively. These values were permitted to confirm that this is typical
insulating material. The mechanical properties of this latter may candidate it to be used in many
fields and several applications. Moreover, the addition of zinc oxide improved both mechanical
and dielectric properties. The optimum sintering conditions gave excellent mechanical
properties: The three point flexural strength, Vickers micro hardness of samples containing
5wt ZnO and sintered at 1160 °C were 242 MPa, 14.5 GPa, respectively. But it did not have a
significant impact on the dielectric properties. Besides, the maximum value of the three point
flexural strength achieved for the samples containing 5 wt TiO2 and 5 wt ZnO are nearby
that of the flexural strength of porcelain containing 5 wt% TiO2 and 30 wt % alumina (about 240
MPa). In other words, the presence of 30 wt % alumina in their product well confirm the benefic
effect of the used raw materials (saving 30 wt % alumina) on porcelain strengthening.Diplôme : Doctorat en sciences En ligne : ../theses/physique/AKAS4189.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10685 دراسة الخصائص الفـيزيـائـية للبورسلان المحضر إنطلاقا من مواد أولية محلية [texte imprimé] / سعاد قصراني, Auteur ; عبد الحميد حرابي, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2017 . - 141 ورقة. ; 30 سم.
2نسخ موجودة مكتبة المركزية
Langues : Arabe (ara)
Catégories : Arabe
الفيزياءTags : Porcelain Zinc oxide Titanium oxide Mechanical properties dielectrical properties Porcelaine oxyde de zinc oxyde de titane propriétés mécaniques propriétés diéléctriques ????????? ????? ????? ????? ??????? ????? ????????? Index. décimale : 530 الفيزياء Résumé : The aim of this work is to prepared porcelain with high mechanical and dielectric properties by
using economical native raw materials without providing ideal high-cost conditions. The basic
porcelain composition was selected consisting of 30 wt% kaolin, 45 wt% potash-feldspar and 25
wt% quartz. It was prepared by sintering the mixture at different temperatures (1140–1260 °C).
The optimum sintering conditions gave a bulk higher density (2.41 g/cm3) and excellent
mechanical properties. The three point flexural strength, Vickers micro-hardness of porcelains
were 205 MPa and 6.8 GPa, respectively. Dielectric measurements have been carried out at 1
KHz from room temperature to 200 °C. The dielectric constant, dielectric loss tangent, and
resistivity of the porcelain sample sintered at 1160 °C were 25, 0.008 and 9 x 1013 .cm,
respectively. So these values reveal that the porcelain is a good insulator. The mechanical and
dielectric properties of porcelain are improved by addition of titanium oxide and zinc oxide. The
addition of titanium oxide improved both mechanical and dielectrical properties. The optimum
sintering conditions gave a higher bulk density (2.47 g.cm−3) and excellent mechanical
properties. The three point flexural strength (3PFS), Vickers micro hardness of samples
containing 5 wt TiO2 and sintered at 1160 °C were 238 MPa, 12.3 GPa , respectively. The
dielectric constant, dielectric loss tangent of samples containing 5 wt TiO2 sintered at 1160 °C
for 2 h were: 31,0.005, respectively. These values were permitted to confirm that this is typical
insulating material. The mechanical properties of this latter may candidate it to be used in many
fields and several applications. Moreover, the addition of zinc oxide improved both mechanical
and dielectric properties. The optimum sintering conditions gave excellent mechanical
properties: The three point flexural strength, Vickers micro hardness of samples containing
5wt ZnO and sintered at 1160 °C were 242 MPa, 14.5 GPa, respectively. But it did not have a
significant impact on the dielectric properties. Besides, the maximum value of the three point
flexural strength achieved for the samples containing 5 wt TiO2 and 5 wt ZnO are nearby
that of the flexural strength of porcelain containing 5 wt% TiO2 and 30 wt % alumina (about 240
MPa). In other words, the presence of 30 wt % alumina in their product well confirm the benefic
effect of the used raw materials (saving 30 wt % alumina) on porcelain strengthening.Diplôme : Doctorat en sciences En ligne : ../theses/physique/AKAS4189.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10685 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité قصر/4189 قصر/4189 Thèse Bibliothèque principale Thèses Disponible
Titre : Elaboration et caractérisation des couches minces du semiconducteur ZnO pures et dopées par le Cadmium Type de document : texte imprimé Auteurs : Badis Rahal, Auteur ; Boubekeur Boudine, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 117 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Zinc oxide Cadmium oxide Nanocomposite Thin films Dip-coating Colloidal Sol-Gel Oxyde de zinc Oxyde de cadmium Couches minces Dip-Coating Colloïdale Index. décimale : 530 Physique Résumé : The present work consists in the elaboration and characterization of the undoped and
cadmium-doped ZnO with different concentrations of cadmium (Cd) (1, 2, 5 and 10% in weight)
thin films in order to improve the structural and optical properties of ZnO. The samples were
prepared using two methods; Colloidal and Sol-Gel and deposited on glass and silicon substrates
by the Dip-coating technique.
The structural characterization showed the formation of ZnO with hexagonal structure
(wurtzite) with a preferential orientation according to plane (002) (sol-gel method). With the
exception of doping with 10% Cd (colloidal method), the formation of the ZnO/CdO
nanocomposite was assisted. SEM and AFM images revealed the nanometric character of our
films. The Raman diffusion confirmed the results of the DRX that is the formation of ZnO with
hexagonal structure (wurtzite).
The RBS spectroscopy has proved the existence, in our films, of the elements (zinc,
cadmium and oxygen) and gave us an idea on the thickness of the thin films. The measurement
of ellipsometry allowed us to evaluate the refractive index of our films and to estimate their
thickness. UV-visible spectroscopy has shown that our layers have a transparency, in the visible,
which varies between 70 and 90%. And that the gap decreases with the increase in doping. The
photoluminescence of the films showed ultraviolet (UV) and visible emissions related to defects.
Auger analysis on layers deposited on silicon substrates gave us an estimate of the thickness.Diplôme : Doctorat en sciences En ligne : ../theses/physique/RAH7052.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10548 Elaboration et caractérisation des couches minces du semiconducteur ZnO pures et dopées par le Cadmium [texte imprimé] / Badis Rahal, Auteur ; Boubekeur Boudine, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2017 . - 117 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Zinc oxide Cadmium oxide Nanocomposite Thin films Dip-coating Colloidal Sol-Gel Oxyde de zinc Oxyde de cadmium Couches minces Dip-Coating Colloïdale Index. décimale : 530 Physique Résumé : The present work consists in the elaboration and characterization of the undoped and
cadmium-doped ZnO with different concentrations of cadmium (Cd) (1, 2, 5 and 10% in weight)
thin films in order to improve the structural and optical properties of ZnO. The samples were
prepared using two methods; Colloidal and Sol-Gel and deposited on glass and silicon substrates
by the Dip-coating technique.
The structural characterization showed the formation of ZnO with hexagonal structure
(wurtzite) with a preferential orientation according to plane (002) (sol-gel method). With the
exception of doping with 10% Cd (colloidal method), the formation of the ZnO/CdO
nanocomposite was assisted. SEM and AFM images revealed the nanometric character of our
films. The Raman diffusion confirmed the results of the DRX that is the formation of ZnO with
hexagonal structure (wurtzite).
The RBS spectroscopy has proved the existence, in our films, of the elements (zinc,
cadmium and oxygen) and gave us an idea on the thickness of the thin films. The measurement
of ellipsometry allowed us to evaluate the refractive index of our films and to estimate their
thickness. UV-visible spectroscopy has shown that our layers have a transparency, in the visible,
which varies between 70 and 90%. And that the gap decreases with the increase in doping. The
photoluminescence of the films showed ultraviolet (UV) and visible emissions related to defects.
Auger analysis on layers deposited on silicon substrates gave us an estimate of the thickness.Diplôme : Doctorat en sciences En ligne : ../theses/physique/RAH7052.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10548 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité RAH/7052 RAH/7052 Thèse Bibliothèque principale Thèses Disponible
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
