2 résultat(s) recherche sur le tag '????? ???? ?????? ???????'    

Elaboration des Couches minces du Semiconducteur ZnO dopées au Cobalt et étude de leurs propriétés structurales, optiques et électriques. / Ahmed Reda Khantoul  

Public ISBD 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) Tags : 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 : pdf 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) Tags : 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 : pdf 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

Modélisation d'un ballon de stockage thermique / Hamza Bouchetiba  

Public ISBD Titre : Modélisation d'un ballon de stockage thermique Type de document : texte imprimé Auteurs : Hamza Bouchetiba, Auteur ; Abla Chaker, Directeur de thèse Editeur : constantine [Algérie] : Université Constantine 1 Année de publication : 2014 Importance : 128 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles Langues : Français (fre) Tags : chauffe eau solaire  capteur solaire  ballon de stockage  installation solaire  stratification  échangeur de chaleur  solar water heating  solar collector  Storage tank  solar installation  heat exchanger  ???? ?????? ??????? ???????  ????? ?????? ???????  ????? ???? ?????? ???????  ???????????????  ????? ????? Index. décimale : 530 Physique Résumé : The stratification in a Storage tank is the key for the good functioning of all installation aiming at meeting thermal needs (production of sanitary hot water, home heating). The work undertaken in this dissertation focuses on the modeling of a storage tank in order to understand better the thermal behavior of the latter one. The impact of many parameters (water injection debit, the nature and the thickness of the insulation, usage of a heat exchanger or an electrical booster) on the temporal evolution of the temperature (in case of charge and of discharge) in the tank was examined. The modeling of the stratification is undertaken by subdividing the tank into N (20) layers. An energy and a masse balance is drawn up in every node. The system of the global equations is resolved by the Crank-Nicolson method. The results obtained show clearly that the last layer heats faster, especially as the injection debit is elevated and the tank homogenization time becomes shorter. Besides, it appears that a good isolation allows to minimize the losses, and to avoid the creation of convective current, which could degrade the stratification. The comparison of the numerical results obtained in this work with those of the literature shows a good agreement. Diplôme : Magistère En ligne : ../theses/physique/BOU6632.pdf Format de la ressource électronique : pdf Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9757 Modélisation d'un ballon de stockage thermique [texte imprimé] / Hamza Bouchetiba, Auteur ; Abla Chaker, Directeur de thèse . - constantine (Route ain el bey, Algérie) : Université Constantine 1, 2014 . - 128 f. ; 30 cm. 2 copies imprimées disponibles Langues : Français (fre) Tags : chauffe eau solaire  capteur solaire  ballon de stockage  installation solaire  stratification  échangeur de chaleur  solar water heating  solar collector  Storage tank  solar installation  heat exchanger  ???? ?????? ??????? ???????  ????? ?????? ???????  ????? ???? ?????? ???????  ???????????????  ????? ????? Index. décimale : 530 Physique Résumé : The stratification in a Storage tank is the key for the good functioning of all installation aiming at meeting thermal needs (production of sanitary hot water, home heating). The work undertaken in this dissertation focuses on the modeling of a storage tank in order to understand better the thermal behavior of the latter one. The impact of many parameters (water injection debit, the nature and the thickness of the insulation, usage of a heat exchanger or an electrical booster) on the temporal evolution of the temperature (in case of charge and of discharge) in the tank was examined. The modeling of the stratification is undertaken by subdividing the tank into N (20) layers. An energy and a masse balance is drawn up in every node. The system of the global equations is resolved by the Crank-Nicolson method. The results obtained show clearly that the last layer heats faster, especially as the injection debit is elevated and the tank homogenization time becomes shorter. Besides, it appears that a good isolation allows to minimize the losses, and to avoid the creation of convective current, which could degrade the stratification. The comparison of the numerical results obtained in this work with those of the literature shows a good agreement. Diplôme : Magistère En ligne : ../theses/physique/BOU6632.pdf Format de la ressource électronique : pdf Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9757

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