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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, Éditeur 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 : 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, Éditeur 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 : 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 : Theoretical and computational approach of physical properties of materials : Tension-strain relationships, Type de document : texte imprimé Auteurs : Hocine Chorfi, Auteur ; Boubekeur Boudine, Directeur de thèse ; Fahima Boudjada, Directeur de thèse Mention d'édition : 28/10/2020 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2020 Importance : 165 f. Format : 30 cm. Note générale : 1 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : physique: Crystallography carbure de silicium oxyde de zinc bisulfure de molybdène défaillance mécanique contrainte-déformation premiers principes théorie fonctionnelle de la densité équation spinodale carburo de silicio óxido de zinc desulfuro de molibdeno falla mecánica tensión-deformación primeros principios teoría funcional de la densidad ecuación espinodal كربید السیلیكون أكسید الزنك ثاني كبریتید المولیبدینوم الفشل المیكانیكي إجھاد الإجھاد المبادئ الأولى نظریة الكثافة الوظیفیة المعادلة اللفافة Index. décimale : 530 Physique Résumé :
Silicon carbide (SiC), Zinc oxyde (ZnO), graphite and molybdenum disulfide (MoS2) attract much interest as materials with technological applications for the development of new electronic devices, in particular the new generation of semiconductors known as Power Semiconductor Devices (PSDs) or Field Effect Transistors (FETs). One of the biggest challenges is to understand the mechanical failure that occurs in the manufacturing process of these materials as a result of the stresses induced during the heating cycles to which they are subjected. Therefore, the fundamental objective of this thesis is the evaluation and analysis in chemical-physical terms of the stress-strain relationships. From these relationships, the limit of mechanical stability of these systems can be determined. Computational simulation allow acces to these relationships in a quantitative way, thus providing information that is difficult to acces, sometimes experimentally.In this study, we present results fromfirstprinciples density functional theory calculations that quantitatively account for the response of selected covalent, ionic and layered materials to general stress conditions. In particular, we have evaluated the ideal strength along the main crystallographic directions of 3C and 2H polytypes ofSiC, hexagonal ABA stacking of graphite, ZnO and 2H-MoS2. Transverse superimposed stress on thetensile stress was taken into account in order to evaluate how the critical strength is affected by thesemulti-load conditions. In general, increasing transverse
stress from negative to positive values leads to the expected decreasing of the critical strength. Few exceptions found in the compressive stressregion correlate with the trends in the density of bonds along the directions with the unexpectedbehavior. In addition, we propose a modified spinodal equation of state able to accurately describethe calculated stress–strain curves. This analytical function is of general use and can also be appliedto experimental data anticipating critical strengths and strain values, and for providing informationon the energy stored in tensile stress processes. The first part of this Doctoral Thesis will be devoted to the presentation of the theoretical and methodological bases of the computational tools that are used in the simulations of the mechanical behavior that will be investigated in these materials. In the second part, stressstrain relationships are evaluated along relevant crystallographic directions, the ideal voltage is calculated and the results are interpreted and explained in terms of the chemical bond and the thermodynamic stability limit using the spinodal equation. The thesis will conclude with a summary of the most relevant contributions of this study.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/CHO7695.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11529 Theoretical and computational approach of physical properties of materials : Tension-strain relationships, [texte imprimé] / Hocine Chorfi, Auteur ; Boubekeur Boudine, Directeur de thèse ; Fahima Boudjada, Directeur de thèse . - 28/10/2020 . - جامعة الإخوة منتوري قسنطينة, 2020 . - 165 f. ; 30 cm.
1 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : physique: Crystallography carbure de silicium oxyde de zinc bisulfure de molybdène défaillance mécanique contrainte-déformation premiers principes théorie fonctionnelle de la densité équation spinodale carburo de silicio óxido de zinc desulfuro de molibdeno falla mecánica tensión-deformación primeros principios teoría funcional de la densidad ecuación espinodal كربید السیلیكون أكسید الزنك ثاني كبریتید المولیبدینوم الفشل المیكانیكي إجھاد الإجھاد المبادئ الأولى نظریة الكثافة الوظیفیة المعادلة اللفافة Index. décimale : 530 Physique Résumé :
Silicon carbide (SiC), Zinc oxyde (ZnO), graphite and molybdenum disulfide (MoS2) attract much interest as materials with technological applications for the development of new electronic devices, in particular the new generation of semiconductors known as Power Semiconductor Devices (PSDs) or Field Effect Transistors (FETs). One of the biggest challenges is to understand the mechanical failure that occurs in the manufacturing process of these materials as a result of the stresses induced during the heating cycles to which they are subjected. Therefore, the fundamental objective of this thesis is the evaluation and analysis in chemical-physical terms of the stress-strain relationships. From these relationships, the limit of mechanical stability of these systems can be determined. Computational simulation allow acces to these relationships in a quantitative way, thus providing information that is difficult to acces, sometimes experimentally.In this study, we present results fromfirstprinciples density functional theory calculations that quantitatively account for the response of selected covalent, ionic and layered materials to general stress conditions. In particular, we have evaluated the ideal strength along the main crystallographic directions of 3C and 2H polytypes ofSiC, hexagonal ABA stacking of graphite, ZnO and 2H-MoS2. Transverse superimposed stress on thetensile stress was taken into account in order to evaluate how the critical strength is affected by thesemulti-load conditions. In general, increasing transverse
stress from negative to positive values leads to the expected decreasing of the critical strength. Few exceptions found in the compressive stressregion correlate with the trends in the density of bonds along the directions with the unexpectedbehavior. In addition, we propose a modified spinodal equation of state able to accurately describethe calculated stress–strain curves. This analytical function is of general use and can also be appliedto experimental data anticipating critical strengths and strain values, and for providing informationon the energy stored in tensile stress processes. The first part of this Doctoral Thesis will be devoted to the presentation of the theoretical and methodological bases of the computational tools that are used in the simulations of the mechanical behavior that will be investigated in these materials. In the second part, stressstrain relationships are evaluated along relevant crystallographic directions, the ideal voltage is calculated and the results are interpreted and explained in terms of the chemical bond and the thermodynamic stability limit using the spinodal equation. The thesis will conclude with a summary of the most relevant contributions of this study.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/CHO7695.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11529 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité CHO/7695 CHO/7695 Thèse Bibliothèque principale Thèses Disponible
Titre : Deposition of ZnO thin films for treatment of water. Type de document : texte imprimé Auteurs : Fouzia Bourfa, Auteur ; Nadhir Attaf, Directeur de thèse Mention d'édition : 27/12/2020 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2020 Importance : 199 f. Format : 30 cm. Note générale : 1 copies imprimées disponibles
Langues : Anglais (eng) Catégories : Français - Anglais
PhysiqueTags : physique:Sciences des matériaux Materials science: Semi-conductor Oxyde de Zinc Couches minces Nanostructuré Photocatalyse Activité antibactérienne Cellules solaires Zinc Oxide Thin films Nanostructured Photocatalysis Antibacterial activity Solar cells أكسيد الزنك الأغشية الرقيقة البنيةالنانوية التحفيز الضوئي النشاط المضاد للبكتيريا الخلايا الشمسية Index. décimale : 530 Physique Résumé :
The semiconductor heterogeneous photocatalytic technique is a kind of green technology that has been used to solve environmental pollution problems. The present study focuses on the screening of potentially photocatalytic ZnO thin films and nanostructures by using them to degrade organic dyes. Primarily Zinc chloride, nitrate and acetate salts were tested for their photocatalytic activity through the degradation of Red reactive and Methylene Blue (MB) in aqueous solution. The select compounds which are deposited by spray pyrolysis show considerable photodegradation efficiency. The studied different parameters such as concentration of dye, time deposition, salt source and seed layer position have a great effect on the photodegradation of this dye. Hydrothermal ZnO nanostructured were also tested for decolorization of MB and the results are very encourage especially for ZnO Nanorods (acetate salt) and ZnO nanoflowers for water treatment and gas sensing. Undoped and ZnO: Ag NPs films on glass and tissue, which prepared by sol-gel, show the capability of zinc oxide and silver nanoparticles to resist the growth of Gram – of K. pneumonia and E. coli by their inhibition zone which reaches 23 mm. Zinc nitrate as a precursor was used to prepare the Al/ ZnO/p-Si heterojunction by ultrasonic spray in order to investigate the photovoltaic parameters of the solar cell of this device. The I-V measurements indicate that the ideality factor n is 1.39 and the barrier height ϕb is 0.67 eV. The ϕb from I-V measurement and Norde’s function (0.69 eV) are in well agreement. While the series resistance Rs obtained from Norde’s function is found 1194 Ω. The diode has a good rectification property,photovoltaic behavior, photosensing and photoresponsivity properties. The electrical and photoelectric characterization confirms that this device is a very suitable candidate as a photodiode, photosensor applications and optoelectronic applications. The ISC and VOC were varied 11.12- 50.73 µA and 125.33- 185.22 mV for various illuminations. The C-V analysis shows that capacitance and conductance of the Al/ZnO/ p-Si diode depends on voltage and frequency. The Na, ϕb and Vbi of this structure are increased with the increasing frequencies.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/BOU7776.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11610 Deposition of ZnO thin films for treatment of water. [texte imprimé] / Fouzia Bourfa, Auteur ; Nadhir Attaf, Directeur de thèse . - 27/12/2020 . - جامعة الإخوة منتوري قسنطينة, 2020 . - 199 f. ; 30 cm.
1 copies imprimées disponibles
Langues : Anglais (eng)
Catégories : Français - Anglais
PhysiqueTags : physique:Sciences des matériaux Materials science: Semi-conductor Oxyde de Zinc Couches minces Nanostructuré Photocatalyse Activité antibactérienne Cellules solaires Zinc Oxide Thin films Nanostructured Photocatalysis Antibacterial activity Solar cells أكسيد الزنك الأغشية الرقيقة البنيةالنانوية التحفيز الضوئي النشاط المضاد للبكتيريا الخلايا الشمسية Index. décimale : 530 Physique Résumé :
The semiconductor heterogeneous photocatalytic technique is a kind of green technology that has been used to solve environmental pollution problems. The present study focuses on the screening of potentially photocatalytic ZnO thin films and nanostructures by using them to degrade organic dyes. Primarily Zinc chloride, nitrate and acetate salts were tested for their photocatalytic activity through the degradation of Red reactive and Methylene Blue (MB) in aqueous solution. The select compounds which are deposited by spray pyrolysis show considerable photodegradation efficiency. The studied different parameters such as concentration of dye, time deposition, salt source and seed layer position have a great effect on the photodegradation of this dye. Hydrothermal ZnO nanostructured were also tested for decolorization of MB and the results are very encourage especially for ZnO Nanorods (acetate salt) and ZnO nanoflowers for water treatment and gas sensing. Undoped and ZnO: Ag NPs films on glass and tissue, which prepared by sol-gel, show the capability of zinc oxide and silver nanoparticles to resist the growth of Gram – of K. pneumonia and E. coli by their inhibition zone which reaches 23 mm. Zinc nitrate as a precursor was used to prepare the Al/ ZnO/p-Si heterojunction by ultrasonic spray in order to investigate the photovoltaic parameters of the solar cell of this device. The I-V measurements indicate that the ideality factor n is 1.39 and the barrier height ϕb is 0.67 eV. The ϕb from I-V measurement and Norde’s function (0.69 eV) are in well agreement. While the series resistance Rs obtained from Norde’s function is found 1194 Ω. The diode has a good rectification property,photovoltaic behavior, photosensing and photoresponsivity properties. The electrical and photoelectric characterization confirms that this device is a very suitable candidate as a photodiode, photosensor applications and optoelectronic applications. The ISC and VOC were varied 11.12- 50.73 µA and 125.33- 185.22 mV for various illuminations. The C-V analysis shows that capacitance and conductance of the Al/ZnO/ p-Si diode depends on voltage and frequency. The Na, ϕb and Vbi of this structure are increased with the increasing frequencies.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/BOU7776.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11610 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/7776 BOU/7776 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 : 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 . - 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 : 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 : 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 البورسلان أكسيد الزنك أكسيد التيتان خصائص ميكانيكية خصائص عزلية 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 : 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 . - 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 البورسلان أكسيد الزنك أكسيد التيتان خصائص ميكانيكية خصائص عزلية 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 : 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
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