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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) Tags : 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)
Tags : 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
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire Etude des réactions de précipitation continue et des propriétés mécaniques des alliages à base d’aluminium. / Chahira Amrane
Titre : Etude des réactions de précipitation continue et des propriétés mécaniques des alliages à base d’aluminium. Type de document : texte imprimé Auteurs : Chahira Amrane, Auteur ; Djamel Hamana, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 135 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Tags : Al-Mg vieillissement précipitation frottement intérieur microstructure propriétés mécaniques Al-Mg alloys ageing precipitation internal friction mechanical properties ????? Al-Mg??????? ??????? ???????? ??????? ?????? ???????? ??????? ??????????? Index. décimale : 530 Physique Résumé : The Al-Mg alloys are widely used in industry especially for marine applications since they
possess good properties such as general corrosion resistance, strength, weldability, weight
compared to other Al alloys and formability. These properties are related to the magnesium
content and to the applied heat treatments. These alloys undergo phase transitions by
precipitation which improves their mechanical properties following solution heat treatments
and suitable ageing ones. Although these alloys are already well studied, the questions
concerning the stability of the microstructure and the effect of the various heat treatments are
always asked. In this work, we present a study on the evolution of the precipitation
(continuous one) reactions after quenching, more precisely the evolution of the precipitated
phases (formation, coalescence, and dissolution), in Al-(12, 10 and 8)wt.% Mg alloys aged at
150 and 250 °C during different ageing times. The use of various experimental techniques as
differential dilatometry, differential scanning calorimetry, scanning and transmission electron
microscopy, X-ray diffraction, microhardness and internal friction measurements, shows their
importance and their complementarity in the study of ageing process in these alloys. The
obtained results clarified the parameters that govern the stage of β’and β particles appearance
and the mechanical responses to the applied heat treatments. The ageing effect of a
supersaturated solid solution on the Temperature Dependent Internal Friction (TDIF) spectra
has been studied. A detailed TDIF analysis revealed the sensibility of the internal friction
technique to the formation of semi-coherent and non-coherent phases (β' and β) but not
enough to the formation of coherent phases (GP zones). Several observations on the nature
and the shape of the precipitates are also discussed.
Diplôme : Doctorat En ligne : ../theses/physique/AMR7234.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10804 Etude des réactions de précipitation continue et des propriétés mécaniques des alliages à base d’aluminium. [texte imprimé] / Chahira Amrane, Auteur ; Djamel Hamana, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2018 . - 135 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Tags : Al-Mg vieillissement précipitation frottement intérieur microstructure propriétés mécaniques Al-Mg alloys ageing precipitation internal friction mechanical properties ????? Al-Mg??????? ??????? ???????? ??????? ?????? ???????? ??????? ??????????? Index. décimale : 530 Physique Résumé : The Al-Mg alloys are widely used in industry especially for marine applications since they
possess good properties such as general corrosion resistance, strength, weldability, weight
compared to other Al alloys and formability. These properties are related to the magnesium
content and to the applied heat treatments. These alloys undergo phase transitions by
precipitation which improves their mechanical properties following solution heat treatments
and suitable ageing ones. Although these alloys are already well studied, the questions
concerning the stability of the microstructure and the effect of the various heat treatments are
always asked. In this work, we present a study on the evolution of the precipitation
(continuous one) reactions after quenching, more precisely the evolution of the precipitated
phases (formation, coalescence, and dissolution), in Al-(12, 10 and 8)wt.% Mg alloys aged at
150 and 250 °C during different ageing times. The use of various experimental techniques as
differential dilatometry, differential scanning calorimetry, scanning and transmission electron
microscopy, X-ray diffraction, microhardness and internal friction measurements, shows their
importance and their complementarity in the study of ageing process in these alloys. The
obtained results clarified the parameters that govern the stage of β’and β particles appearance
and the mechanical responses to the applied heat treatments. The ageing effect of a
supersaturated solid solution on the Temperature Dependent Internal Friction (TDIF) spectra
has been studied. A detailed TDIF analysis revealed the sensibility of the internal friction
technique to the formation of semi-coherent and non-coherent phases (β' and β) but not
enough to the formation of coherent phases (GP zones). Several observations on the nature
and the shape of the precipitates are also discussed.
Diplôme : Doctorat En ligne : ../theses/physique/AMR7234.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10804 Exemplaires
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Titre : Tenue et comportement au feu des bétons Type de document : texte imprimé Auteurs : Ishaq Allal, Auteur ; Hocine Chabil, Directeur de thèse ; Belkacem Toumi, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2015 Importance : 161 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Tags : béton ordinaire béton autoplaçant bétons de fibres de chanvre fibres
polypropylènes fibres métalliques propriétés mécaniques propriétés physiques feu ordinary concrete self-compacting concrete hemp fibers concrete polypropylene
fibers steel fibers mechanical properties physical properties fire ???????? ??????? ???????? ???????? ????? ??????? ?????? ????? ????? ????? ?????? ??????? ??????? ???????? ????? ????????? ????? ???????? ?????Index. décimale : 624 Génie civil Résumé : Concrete is a material of construction, its development and use in buildings and civil engineering works do not cease to increase in worldwide due to its ease of implementation and low cost.
Under the influence of fire and high temperatures, the concrete elements can suffer drop mechanical performance, thermal and physical, they can also undergo thermal instability characterized by spalling and it can also manifest explosive behavior.
The purpose of this research is to make an experimentally data base on the mechanical and physical fire behavior of three types of concrete, ordinary concrete, self-compacting concrete and hemp fiber concrete, to compare the behavior of self-compacting concrete with that ordinary concrete and the effect of the addition of polypropylene and steel fibers on the behavior of them.
For this, 9 formulations were defined, for each type of concrete, three compositions are defined:
a composition without fiber, a composition containing polypropylene fibers with a dosage of 2 kg/m3, a composition containing steel fibers with a dosage of 40 kg/m3.
The different concretes were subjected to a real fire, the speed to increase of temperature is 67.3 °C/min, the total duration of exposure to fire is about 85 minutes. The study shows a drop in physical and mechanical performance of different concretes.Diplôme : Magistère En ligne : ../theses/gcivil/ALL6863.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10177 Tenue et comportement au feu des bétons [texte imprimé] / Ishaq Allal, Auteur ; Hocine Chabil, Directeur de thèse ; Belkacem Toumi, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2015 . - 161 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Tags : béton ordinaire béton autoplaçant bétons de fibres de chanvre fibres
polypropylènes fibres métalliques propriétés mécaniques propriétés physiques feu ordinary concrete self-compacting concrete hemp fibers concrete polypropylene
fibers steel fibers mechanical properties physical properties fire ???????? ??????? ???????? ???????? ????? ??????? ?????? ????? ????? ????? ?????? ??????? ??????? ???????? ????? ????????? ????? ???????? ?????Index. décimale : 624 Génie civil Résumé : Concrete is a material of construction, its development and use in buildings and civil engineering works do not cease to increase in worldwide due to its ease of implementation and low cost.
Under the influence of fire and high temperatures, the concrete elements can suffer drop mechanical performance, thermal and physical, they can also undergo thermal instability characterized by spalling and it can also manifest explosive behavior.
The purpose of this research is to make an experimentally data base on the mechanical and physical fire behavior of three types of concrete, ordinary concrete, self-compacting concrete and hemp fiber concrete, to compare the behavior of self-compacting concrete with that ordinary concrete and the effect of the addition of polypropylene and steel fibers on the behavior of them.
For this, 9 formulations were defined, for each type of concrete, three compositions are defined:
a composition without fiber, a composition containing polypropylene fibers with a dosage of 2 kg/m3, a composition containing steel fibers with a dosage of 40 kg/m3.
The different concretes were subjected to a real fire, the speed to increase of temperature is 67.3 °C/min, the total duration of exposure to fire is about 85 minutes. The study shows a drop in physical and mechanical performance of different concretes.Diplôme : Magistère En ligne : ../theses/gcivil/ALL6863.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10177 Exemplaires
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Titre : تحضير و دراسة خصائص الانورثيت المحضر انطلاقا من الكاولان DD2والكلسيت Type de document : texte imprimé Auteurs : سمية زعيو, Auteur ; عبد الحمید حرابي, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 118 ورقة. Format : 30 سم. Note générale : 2نسخ موجودة مكتبة المركزية
Langues : Arabe (ara) Tags : Frittage Anorthite Na2CO3 Fe2O3 propriétés mécaniques Bioactivité Sintering sodium carbonate ferric oxide Mechanical properties Bioactivity Index. décimale : 530 الفيزياء Résumé : In this work, anorthite have a chemical formula (CaO.Al2O3.2SiO2) was prepared from local kaolin and calcium oxide (CaO) extracted from CaCO3. In the first stage, two different methods were followed. The second method shows more efficiency, it gives a good sintering percentage over 96 % of anorthite theoretical density.
The effect of different amounts of (Na2CO3) and (Fe2O3) on the anorthite sintering and crystallisation was studied, 3 wt% sodium carbonate addition increases the density to values greater than 97 % of theoretical. Moreover, the density of about 98 % of the theoretical was reached for samples containing 1.5 wt% Fe2O3 sintered at 900 °C for 1 h and promotes anorthite crystallisation at lower temperatures. The anorthite phase appeared earlier at 850°C.
The prepared samples show a tensile strength of 82 MPa for 3% of Na2CO3 addition which corresponds to a flexural strength of about 222 MPa, a Vickers micro-hardness of 8.7 GPa that were treated at 900°C.
Excellent values of tensile strength about 96 MPa which corresponding to a flexural strength of 259 MPa, a Vickers micro-hardness of 9.1 GPa for the simples with 1.5 % weight of Fe2O3 were also obtained.
Finally, the bioactivity of anorthite by the possibility of formation of apatite on the surface of anorthite immersed in simulated body fluid (SBF) was confirmed.Diplôme : Doctorat en sciences En ligne : ../theses/physique/AZAI4214.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10660 تحضير و دراسة خصائص الانورثيت المحضر انطلاقا من الكاولان DD2والكلسيت [texte imprimé] / سمية زعيو, Auteur ; عبد الحمید حرابي, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2017 . - 118 ورقة. ; 30 سم.
2نسخ موجودة مكتبة المركزية
Langues : Arabe (ara)
Tags : Frittage Anorthite Na2CO3 Fe2O3 propriétés mécaniques Bioactivité Sintering sodium carbonate ferric oxide Mechanical properties Bioactivity Index. décimale : 530 الفيزياء Résumé : In this work, anorthite have a chemical formula (CaO.Al2O3.2SiO2) was prepared from local kaolin and calcium oxide (CaO) extracted from CaCO3. In the first stage, two different methods were followed. The second method shows more efficiency, it gives a good sintering percentage over 96 % of anorthite theoretical density.
The effect of different amounts of (Na2CO3) and (Fe2O3) on the anorthite sintering and crystallisation was studied, 3 wt% sodium carbonate addition increases the density to values greater than 97 % of theoretical. Moreover, the density of about 98 % of the theoretical was reached for samples containing 1.5 wt% Fe2O3 sintered at 900 °C for 1 h and promotes anorthite crystallisation at lower temperatures. The anorthite phase appeared earlier at 850°C.
The prepared samples show a tensile strength of 82 MPa for 3% of Na2CO3 addition which corresponds to a flexural strength of about 222 MPa, a Vickers micro-hardness of 8.7 GPa that were treated at 900°C.
Excellent values of tensile strength about 96 MPa which corresponding to a flexural strength of 259 MPa, a Vickers micro-hardness of 9.1 GPa for the simples with 1.5 % weight of Fe2O3 were also obtained.
Finally, the bioactivity of anorthite by the possibility of formation of apatite on the surface of anorthite immersed in simulated body fluid (SBF) was confirmed.Diplôme : Doctorat en sciences En ligne : ../theses/physique/AZAI4214.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10660 Exemplaires
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