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Partager le résultat de cette recherche Interroger des sources externesEtude des céramiques diélectriques du type BaTiO3-CaTiO3 Influence de différentes additions / Tarek Bezzi
Titre : Etude des céramiques diélectriques du type BaTiO3-CaTiO3 Influence de différentes additions Type de document : texte imprimé Auteurs : Tarek Bezzi, Auteur ; S.E. Barama, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 144 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles.
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : le titanate de baryum le titanate de calcium l’oxyde de bore le frittage ferroélectriques la permittivité relative pertes diélectriques hydrothermale Barium titanate Calcium titanate Boron oxide sintering ferroelectric relative permittivity dielectric loss hydrothermal تيتانات الباريوم تيتانات الكالسيوم أكسيد البور السماحية النسبية المعالجة
الحراريةIndex. décimale : 530 Physique Résumé : In this work we are concerned with the preparation and characterisation of BaTiO3 - CaTiO3 –B2O3 nonlinear dielectric materials. Samples of (1-x) BaTiO3 +xCaTiO3 +y B2O3 type (with x=0.3; 0.7 and 0.01≤y≤0.03) were elaborated by sintering at various temperatures (1200, 1250, 1300 and 1350°C respectively) during 03h. The obtained results showed an improvement in the relative density in the case of samples containing 1% B2O3. At the opposite, the relative density of the sintered samples decreases for higher B2O3 percentage probably in relation with the apparition of liquid phase. For example, in the case of samples containing 30 % mol. in CT and sintered 1300°C, the addition of 1% mol. in B2O3 leads to an increasing in the relative density from 65 to 93% and from 78 to 95% in the case 1350°C sintering temperature.
On the other hand, the obtained results reveal an increase in the relative density with sintering temperature for all B2O3 percentage. X-rays diffraction analyses carried out with different sintered samples showed the formation of both BT and CT solid solutions, and a non identified phase. The proportion of the farmer phase increases as a function of B2O3 addition.
Dielectric measurements carried out with samples containing 30% CT showed that the relative permittivity (εr) increases as function of BO additions in the case of samples sintered at 1200°C. In the case of higher sintering temperatures, maximum of permittivity is obtained with 1% BO. In addition, εr evolution with the temperature reveals ferro→ para transformation in all considered samples.
In the second part, a new simple method was used, saving time and effort for the preparation of the BCT. This method is the hydrothermal, a series of BCT samples were prepared without and with addition of F2O3. We used in autoclave Ti metal plates with BaOH, CaO powders in addition to F2O3 Chloride under temperature conditions of 200 ° C. for different periods of time. This allowed us to have the BCT compound. Following the addition of Iron Chloride, we noticed a change in the structure approved by the Raman, DRX and XPS analyzes. This latter confirms the presence of all the elements used in the synthesis
of the composit.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/BEZ7175.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10582 Etude des céramiques diélectriques du type BaTiO3-CaTiO3 Influence de différentes additions [texte imprimé] / Tarek Bezzi, Auteur ; S.E. Barama, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2017 . - 144 f. ; 30 cm.
2 copies imprimées disponibles.
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : le titanate de baryum le titanate de calcium l’oxyde de bore le frittage ferroélectriques la permittivité relative pertes diélectriques hydrothermale Barium titanate Calcium titanate Boron oxide sintering ferroelectric relative permittivity dielectric loss hydrothermal تيتانات الباريوم تيتانات الكالسيوم أكسيد البور السماحية النسبية المعالجة
الحراريةIndex. décimale : 530 Physique Résumé : In this work we are concerned with the preparation and characterisation of BaTiO3 - CaTiO3 –B2O3 nonlinear dielectric materials. Samples of (1-x) BaTiO3 +xCaTiO3 +y B2O3 type (with x=0.3; 0.7 and 0.01≤y≤0.03) were elaborated by sintering at various temperatures (1200, 1250, 1300 and 1350°C respectively) during 03h. The obtained results showed an improvement in the relative density in the case of samples containing 1% B2O3. At the opposite, the relative density of the sintered samples decreases for higher B2O3 percentage probably in relation with the apparition of liquid phase. For example, in the case of samples containing 30 % mol. in CT and sintered 1300°C, the addition of 1% mol. in B2O3 leads to an increasing in the relative density from 65 to 93% and from 78 to 95% in the case 1350°C sintering temperature.
On the other hand, the obtained results reveal an increase in the relative density with sintering temperature for all B2O3 percentage. X-rays diffraction analyses carried out with different sintered samples showed the formation of both BT and CT solid solutions, and a non identified phase. The proportion of the farmer phase increases as a function of B2O3 addition.
Dielectric measurements carried out with samples containing 30% CT showed that the relative permittivity (εr) increases as function of BO additions in the case of samples sintered at 1200°C. In the case of higher sintering temperatures, maximum of permittivity is obtained with 1% BO. In addition, εr evolution with the temperature reveals ferro→ para transformation in all considered samples.
In the second part, a new simple method was used, saving time and effort for the preparation of the BCT. This method is the hydrothermal, a series of BCT samples were prepared without and with addition of F2O3. We used in autoclave Ti metal plates with BaOH, CaO powders in addition to F2O3 Chloride under temperature conditions of 200 ° C. for different periods of time. This allowed us to have the BCT compound. Following the addition of Iron Chloride, we noticed a change in the structure approved by the Raman, DRX and XPS analyzes. This latter confirms the presence of all the elements used in the synthesis
of the composit.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/BEZ7175.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10582 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEZ/7175 BEZ/7175 Thèse Bibliothèque principale Thèses Disponible
Titre : Etude géologique et gîtologique de la minéralisation ferrifère et cupro-barytique des massifs carbonates de Kef Sidi Marouf, kef derdja et Kef Boulehmame, commune de Sidi Marouf (ne Algerien) Type de document : texte imprimé Auteurs : Azzouz Benlamari, Auteur ; Youcef Bouftouha, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2015 Importance : 88 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
Sciences de la terreTags : Geologie ressources minerales Sidi Marouf formations carbonatées fracturation dissolution karstification dolomitisation silicification minéralisation cupro-ferro-barytique hydrothermale carbonate formations fracturing karst dolomitization mineralization copper-iron-baryte hydrothermal سيدي معروف انكسارات التكوينات الجيولوجية التمعدنات الفراغات الكارستية الباريتين المحاليل الهيدروتيرمالية Index. décimale : 550 Sciences de la terre Résumé :
The region of Sidi Maarouf and its surroundings in north-eastern Algeria is distinguished by the presence of a number of massive carbonates of Jurassic age (Kef Sidi Marouf, Kef oulehmame and Kef Derdja). These massives carbonates, belonging to the external domain of maghrebide range are located in the transition zone between the external and the internal domain, represented by metamorphic formations of the Kabyle plinth.
The mountains of Kef Sidi Marouf and Kef Boulehmame present an interest economic region, because they contain iron deposits and carbonate rocks that can be used for steel, cement and aggregates, while Kef Derdja contains only one index of a copper-iron-baryte mineralization and a quarry for the extraction of limestone blocks to rockfill.
These carbonate mountains occupying a peridiapiric position are formed mainly by carbonate rocks of jurassic age. The formations of these massifs show traces of several tectonic events (fracturing, grinding, rebound layers in the vertical).
The intense fracturing of the carbonate rocks greatly promoted the circulation of fluids and led the development of dissolution phenomena of karst, dolomitization, silicification and mineralization.
The ore bodies form the ore deposits of study area have variable morphologies and volumes. However, cluster and lode are the most common.
Mineralization of carbonate masses of the region of Sidi Marouf is composed mainly of iron oxides and hydroxides (hematite, goethite and limonite), plus a barium-copper mineralization.
The geological and gîtological data of mineralizations hosted in carbonate mountains formations in the region of Sidi Marouf reveal a set up of these mineralizations by hydrothermal solutions.
Diplôme : Magistère En ligne : ../theses/sc-terre/BEN6899.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10230 Etude géologique et gîtologique de la minéralisation ferrifère et cupro-barytique des massifs carbonates de Kef Sidi Marouf, kef derdja et Kef Boulehmame, commune de Sidi Marouf (ne Algerien) [texte imprimé] / Azzouz Benlamari, Auteur ; Youcef Bouftouha, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2015 . - 88 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Sciences de la terreTags : Geologie ressources minerales Sidi Marouf formations carbonatées fracturation dissolution karstification dolomitisation silicification minéralisation cupro-ferro-barytique hydrothermale carbonate formations fracturing karst dolomitization mineralization copper-iron-baryte hydrothermal سيدي معروف انكسارات التكوينات الجيولوجية التمعدنات الفراغات الكارستية الباريتين المحاليل الهيدروتيرمالية Index. décimale : 550 Sciences de la terre Résumé :
The region of Sidi Maarouf and its surroundings in north-eastern Algeria is distinguished by the presence of a number of massive carbonates of Jurassic age (Kef Sidi Marouf, Kef oulehmame and Kef Derdja). These massives carbonates, belonging to the external domain of maghrebide range are located in the transition zone between the external and the internal domain, represented by metamorphic formations of the Kabyle plinth.
The mountains of Kef Sidi Marouf and Kef Boulehmame present an interest economic region, because they contain iron deposits and carbonate rocks that can be used for steel, cement and aggregates, while Kef Derdja contains only one index of a copper-iron-baryte mineralization and a quarry for the extraction of limestone blocks to rockfill.
These carbonate mountains occupying a peridiapiric position are formed mainly by carbonate rocks of jurassic age. The formations of these massifs show traces of several tectonic events (fracturing, grinding, rebound layers in the vertical).
The intense fracturing of the carbonate rocks greatly promoted the circulation of fluids and led the development of dissolution phenomena of karst, dolomitization, silicification and mineralization.
The ore bodies form the ore deposits of study area have variable morphologies and volumes. However, cluster and lode are the most common.
Mineralization of carbonate masses of the region of Sidi Marouf is composed mainly of iron oxides and hydroxides (hematite, goethite and limonite), plus a barium-copper mineralization.
The geological and gîtological data of mineralizations hosted in carbonate mountains formations in the region of Sidi Marouf reveal a set up of these mineralizations by hydrothermal solutions.
Diplôme : Magistère En ligne : ../theses/sc-terre/BEN6899.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10230 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEN/6899 BEN/6899 Thèse Bibliothèque principale Thèses Disponible
Titre : Study of ZnO nanorods decorated by Cu2O, CdS and PbS for Photoelectrochemical Application Type de document : texte imprimé Auteurs : Sihem Lakehal, Auteur ; S. Achour, Directeur de thèse Editeur : constantine [Algérie] : Université Constantine 1 Année de publication : 2014 Importance : 101 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : ZnO hydrothermale nanoparticules nanobatonet photoelectrochimie nanorods nanoparticles hydrothermal CdS PbS CuO Cu2O أكسید الزنك عصیات نانومتریة جزیئات نانومتریة كبریت الرصاص من كبریت الكادمیوم من
أكسید النحاسIndex. décimale : 530 Physique Résumé : Fabrication and characterization of a heterojunction structured by CdS, PbS, CuO-Cu2O/ZnO nanorods-array panels were presented. Firstly, ZnO nanorods-array panels were prepared by using a hydrothermal approach where wurtzite ZnO nanorods with a diameter of about 100 nm grew perpendicularly to glass substrate. Secondly, CdS, PbS, CuO-Cu2O nanoparticles were deposited onto the surface of the ZnO nanorods-arrays by using exchange ions method, and the CdS, PbS shell/ZnO core heterojunction were thus obtained. Scanning electron microscopy and
transmission electron microscopy results indicate that the CdS, PbS, CuO-Cu2O nanoparticles
can be uniformly deposited on the ZnO nanorods arrays and the thickness of the shell can be
controlled through varying the number of the adsorption and reaction time. Optical property indicate that the as-fabricated heterojunction structure not only exhibits a high absorption of the incident light in visible region but also can show improved photocurrent with respect to the litterateur results.Diplôme : Doctorat En ligne : ../theses/physique/LAK6661.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9812 Study of ZnO nanorods decorated by Cu2O, CdS and PbS for Photoelectrochemical Application [texte imprimé] / Sihem Lakehal, Auteur ; S. Achour, Directeur de thèse . - constantine [Algérie] : Université Constantine 1, 2014 . - 101 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : ZnO hydrothermale nanoparticules nanobatonet photoelectrochimie nanorods nanoparticles hydrothermal CdS PbS CuO Cu2O أكسید الزنك عصیات نانومتریة جزیئات نانومتریة كبریت الرصاص من كبریت الكادمیوم من
أكسید النحاسIndex. décimale : 530 Physique Résumé : Fabrication and characterization of a heterojunction structured by CdS, PbS, CuO-Cu2O/ZnO nanorods-array panels were presented. Firstly, ZnO nanorods-array panels were prepared by using a hydrothermal approach where wurtzite ZnO nanorods with a diameter of about 100 nm grew perpendicularly to glass substrate. Secondly, CdS, PbS, CuO-Cu2O nanoparticles were deposited onto the surface of the ZnO nanorods-arrays by using exchange ions method, and the CdS, PbS shell/ZnO core heterojunction were thus obtained. Scanning electron microscopy and
transmission electron microscopy results indicate that the CdS, PbS, CuO-Cu2O nanoparticles
can be uniformly deposited on the ZnO nanorods arrays and the thickness of the shell can be
controlled through varying the number of the adsorption and reaction time. Optical property indicate that the as-fabricated heterojunction structure not only exhibits a high absorption of the incident light in visible region but also can show improved photocurrent with respect to the litterateur results.Diplôme : Doctorat En ligne : ../theses/physique/LAK6661.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9812 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité LAK/6661 LAK/6661 Thèse Bibliothèque principale Thèses Disponible
Titre : Elaboration et caractérisation des nano poudres d’oxyde d’étain (SnO2) Type de document : texte imprimé Auteurs : Nassima Boufaa, Auteur ; Smail Boudjadar, Directeur de thèse Editeur : Constantine : Université Mentouri Constantine Année de publication : 2012 Importance : 85 f. Format : 31 cm. Note générale : Magister
2 copies imprimées disponiblesLangues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : dioxyde d’étain hydrothermale énergie de la micro-onde photoluminescence défauts intrinsèques Index. décimale : 530 Physique En ligne : ../theses/physique/BOU6231.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=6209 Elaboration et caractérisation des nano poudres d’oxyde d’étain (SnO2) [texte imprimé] / Nassima Boufaa, Auteur ; Smail Boudjadar, Directeur de thèse . - Constantine : Université Mentouri Constantine, 2012 . - 85 f. ; 31 cm.
Magister
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : dioxyde d’étain hydrothermale énergie de la micro-onde photoluminescence défauts intrinsèques Index. décimale : 530 Physique En ligne : ../theses/physique/BOU6231.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=6209 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/6231 BOU/6231 Thèse Bibliothèque principale Thèses Disponible
