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Partager le résultat de cette recherche Interroger des sources externesEtude de la microstructure et des propriétés électroniques des composés intermétalliques CeNi2, CeNi5 et NiZr avant et après hydrogénation / Atika Roustila
Titre : Etude de la microstructure et des propriétés électroniques des composés intermétalliques CeNi2, CeNi5 et NiZr avant et après hydrogénation Type de document : texte imprimé Auteurs : Atika Roustila ; Univ. de Constantine, Éditeur scientifique ; J. Chene, Directeur de thèse Année de publication : 1996 Importance : 118 f. Note générale : 1 Disponible à la salle de recherche
2 Disponibles au magasin de la bibliothèque centraleLangues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Microstructure Hydrogénation Cmposés intermétalliques CeNi2 CeNi5 NiZr Index. décimale : 530 Physique Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=3075 Etude de la microstructure et des propriétés électroniques des composés intermétalliques CeNi2, CeNi5 et NiZr avant et après hydrogénation [texte imprimé] / Atika Roustila ; Univ. de Constantine, Éditeur scientifique ; J. Chene, Directeur de thèse . - 1996 . - 118 f.
1 Disponible à la salle de recherche
2 Disponibles au magasin de la bibliothèque centrale
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Microstructure Hydrogénation Cmposés intermétalliques CeNi2 CeNi5 NiZr Index. décimale : 530 Physique Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=3075 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité ROU/2923 ROU/2923 Thèse Bibliothèque principale Thèses Disponible 
Titre : Caractérisation microbiologique de la peau de chèvre utilisée dans la fabrication du fromage traditionnel Algérien « Bouhezza » Type de document : texte imprimé Auteurs : Asma Senoussi, Auteur ; Mohamed-Nasreddine Zidoune, Directeur de thèse ; Leila Benatallah Benchikh El Feggoun, Directeur de thèse Editeur : constantine [Algérie] : Université Constantine 1 Année de publication : 2013 Importance : 92 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles Langues : Français (fre) Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : جلد الماعز"شكوة" علم الاحياء المجهرية البنية المجهرية Goat skin « Chekoua » microbiology microstructure PCR-TTGE Peau de chèvre « Chekoua » microbiologie Index. décimale : 640 Industrie Alimentaire Résumé : The objective of our work is the characterization ofgoat skinmicroflora and microstructure during its preparation which plays a very important role in ripening.
Bouhezzais a local Algerian traditionalcheese. Its making process requires the exceptional use of treated goat skin or ewe skin called"Chekoua"for draining and ripening.
The draininghappenscontinuously through "Chekoua" perforations. According to tradition, goat skin is treated with salt and juniper and it must be in contact with "lben" for a whole night.
We have made four bags (small chekoutes) from two whole skins. Two were maintained fresh and the other two were air dried. The results showed that the initial Chekouatesmicroflorawere characterized with low bacterial load with the absence of yeast; molds and the pathogenic flora. However, the contact with "lben" provoked an increase of the
microbial load and the apparition of yeasts.
The PCR-Temporal Temperature Gel Electrophoresisshowed a diversification of the bacterial ecosystem with the dominance of lactic bacteria. A microorganisms exchange has been observed between the "Chekoua" and the "lben".
The Microscopic (MEB)observation has revealed that the surface of chekouatesis wrinkled characterized with skin folds. The fibers are thicker and distinct in the fresh skin contrary to the dried skin which has showed nearly merged fibers.Pores diameter varies between 41 to 140µm in the fresh"chekoua" and 34 to 121 µm in the dried one.
In the other hand, the microscopic (MEB and MCBL) observationshowed the microbial enrichment of "chekoua"biofilm after being in contact with"lben".The observed microorganisms arein form of diplococcal, bacilli and yeast. The confocal microscopy (MCBL)revealed the presence of living and dead bacteria in the four bags.Diplôme : Magistère En ligne : ../theses/agronomie/SEN6416.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9443 Caractérisation microbiologique de la peau de chèvre utilisée dans la fabrication du fromage traditionnel Algérien « Bouhezza » [texte imprimé] / Asma Senoussi, Auteur ; Mohamed-Nasreddine Zidoune, Directeur de thèse ; Leila Benatallah Benchikh El Feggoun, Directeur de thèse . - constantine [Algérie] : Université Constantine 1, 2013 . - 92 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : جلد الماعز"شكوة" علم الاحياء المجهرية البنية المجهرية Goat skin « Chekoua » microbiology microstructure PCR-TTGE Peau de chèvre « Chekoua » microbiologie Index. décimale : 640 Industrie Alimentaire Résumé : The objective of our work is the characterization ofgoat skinmicroflora and microstructure during its preparation which plays a very important role in ripening.
Bouhezzais a local Algerian traditionalcheese. Its making process requires the exceptional use of treated goat skin or ewe skin called"Chekoua"for draining and ripening.
The draininghappenscontinuously through "Chekoua" perforations. According to tradition, goat skin is treated with salt and juniper and it must be in contact with "lben" for a whole night.
We have made four bags (small chekoutes) from two whole skins. Two were maintained fresh and the other two were air dried. The results showed that the initial Chekouatesmicroflorawere characterized with low bacterial load with the absence of yeast; molds and the pathogenic flora. However, the contact with "lben" provoked an increase of the
microbial load and the apparition of yeasts.
The PCR-Temporal Temperature Gel Electrophoresisshowed a diversification of the bacterial ecosystem with the dominance of lactic bacteria. A microorganisms exchange has been observed between the "Chekoua" and the "lben".
The Microscopic (MEB)observation has revealed that the surface of chekouatesis wrinkled characterized with skin folds. The fibers are thicker and distinct in the fresh skin contrary to the dried skin which has showed nearly merged fibers.Pores diameter varies between 41 to 140µm in the fresh"chekoua" and 34 to 121 µm in the dried one.
In the other hand, the microscopic (MEB and MCBL) observationshowed the microbial enrichment of "chekoua"biofilm after being in contact with"lben".The observed microorganisms arein form of diplococcal, bacilli and yeast. The confocal microscopy (MCBL)revealed the presence of living and dead bacteria in the four bags.Diplôme : Magistère En ligne : ../theses/agronomie/SEN6416.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9443 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité SEN/6416 SEN//6416 Thèse Bibliothèque principale Thèses Disponible Documents numériques
texte intégraleAdobe Acrobat PDF
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) Catégories : Français - Anglais
PhysiqueTags : Al-Mg vieillissement précipitation frottement intérieur microstructure propriétés mécaniques Al-Mg alloys ageing precipitation internal friction mechanical properties سبائك Al-Mgالتعتيق الترسيب الاحتكاك الداخلي البنية المجهرية الخصائص الميكانيكية 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 . - جامعة الإخوة منتوري قسنطينة, 2018 . - 135 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Al-Mg vieillissement précipitation frottement intérieur microstructure propriétés mécaniques Al-Mg alloys ageing precipitation internal friction mechanical properties سبائك Al-Mgالتعتيق الترسيب الاحتكاك الداخلي البنية المجهرية الخصائص الميكانيكية 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 (1)
Code-barres Cote Support Localisation Section Disponibilité AMR/7234 AMR/7234 Thèse Bibliothèque principale Thèses Disponible
Titre : Elaboration et caractérisation par RX d’oxydes sous forme de couches minces Type de document : texte imprimé Auteurs : Amel Grine, Auteur ; Ali Boultif, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2015 Importance : 71 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Diffraction par poudre microstructure couches minces méthodes de déconvolution RFI profil de raies Powder diffraction thin deconvolution methods line profile الانعراج على المسحوق البنية المجهرية السطوح الرقيقة الدالةRFI-deconvolution-profil Line Index. décimale : 530 Physique Résumé : The subject of this thesis deals with the development and characterization of thin films of iron oxide. The
objective is to optimize the parameters for development of thin films crystallized well.
The preparation of thin films studied was carried out by the sol-gel developed in the laboratory method.
Two kinds of aqueous solutions were used to make these thin layers. The first type of solution is formed of
a mixture of 1 ml of FeCl3 and 3 ml of HCl and the second type of solution consists of a mixture of 3 ml of
FeCl3 and 1 ml of HCl. Each of the two types is used to prepare several series of thin layers. Each set
corresponds to a given concentration of [Fe3+] and it consists of several thin films prepared at various
annealing temperatures.
The series from the first type of solution have not led to a diffraction. The thin films prepared from the
second type of solution have also, showed an insufficient crystallization except in the case of the series that
resulted from the concentration of 0.05 [Fe3+]. It is this series of layers that allowed, therefore, to continue
the work of memory analysis. Another series of layers obtained based on the concentration of 0.06 has
proved well crystallized.
Thin films of good crystallinity were subjected to X-ray analysis, SEM, in the IR and UV Visible.
The X-ray analysis was used to evaluate the average size of the crystallites constituting the layers. Thus,
the average sizes found for the crystallites grow with annealing temperature: the size from 20 nm to 130
nm. The microstrain serving on well-crystallized thin films were estimated by analyzing the diffraction
patterns. The values of deformations of lattice planes vary between 1/1000 and 7/1000.
The SEM images show that the morphology of the layers varies depending on the temperature. Average
morphology is first needles, low temperature and gets thick when the temperature increases, with a
curved shape of grains at 550 ° C.
The spectra obtained by UV spectroscopy show that the transmittance of the thin film of Fe2O3 increases
substantially as a function of the annealing temperature. There is a ""gap"" significantly larger between the
layer which have not undergone annealing and other layers obtained with annealing.
Furthermore, IR spectroscopy spectra show intense absorption peaks at wave numbers of around .2400
cm-1, 3350 cm-1 corresponding to the layer to 350 °C and around 2800 cm-1 and 3400 cm-1 for the layer
without annealing.
Diplôme : Magistère En ligne : ../theses/physique/GRI6950.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10326 Elaboration et caractérisation par RX d’oxydes sous forme de couches minces [texte imprimé] / Amel Grine, Auteur ; Ali Boultif, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2015 . - 71 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Diffraction par poudre microstructure couches minces méthodes de déconvolution RFI profil de raies Powder diffraction thin deconvolution methods line profile الانعراج على المسحوق البنية المجهرية السطوح الرقيقة الدالةRFI-deconvolution-profil Line Index. décimale : 530 Physique Résumé : The subject of this thesis deals with the development and characterization of thin films of iron oxide. The
objective is to optimize the parameters for development of thin films crystallized well.
The preparation of thin films studied was carried out by the sol-gel developed in the laboratory method.
Two kinds of aqueous solutions were used to make these thin layers. The first type of solution is formed of
a mixture of 1 ml of FeCl3 and 3 ml of HCl and the second type of solution consists of a mixture of 3 ml of
FeCl3 and 1 ml of HCl. Each of the two types is used to prepare several series of thin layers. Each set
corresponds to a given concentration of [Fe3+] and it consists of several thin films prepared at various
annealing temperatures.
The series from the first type of solution have not led to a diffraction. The thin films prepared from the
second type of solution have also, showed an insufficient crystallization except in the case of the series that
resulted from the concentration of 0.05 [Fe3+]. It is this series of layers that allowed, therefore, to continue
the work of memory analysis. Another series of layers obtained based on the concentration of 0.06 has
proved well crystallized.
Thin films of good crystallinity were subjected to X-ray analysis, SEM, in the IR and UV Visible.
The X-ray analysis was used to evaluate the average size of the crystallites constituting the layers. Thus,
the average sizes found for the crystallites grow with annealing temperature: the size from 20 nm to 130
nm. The microstrain serving on well-crystallized thin films were estimated by analyzing the diffraction
patterns. The values of deformations of lattice planes vary between 1/1000 and 7/1000.
The SEM images show that the morphology of the layers varies depending on the temperature. Average
morphology is first needles, low temperature and gets thick when the temperature increases, with a
curved shape of grains at 550 ° C.
The spectra obtained by UV spectroscopy show that the transmittance of the thin film of Fe2O3 increases
substantially as a function of the annealing temperature. There is a ""gap"" significantly larger between the
layer which have not undergone annealing and other layers obtained with annealing.
Furthermore, IR spectroscopy spectra show intense absorption peaks at wave numbers of around .2400
cm-1, 3350 cm-1 corresponding to the layer to 350 °C and around 2800 cm-1 and 3400 cm-1 for the layer
without annealing.
Diplôme : Magistère En ligne : ../theses/physique/GRI6950.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10326 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité GRI/6950 GRI/6950 Thèse Bibliothèque principale Thèses Disponible
Titre : Etude, conception et réalisation de capteurs à base de matériaux céramiques. Type de document : texte imprimé Auteurs : Ahmed Bouchekhlal, Auteur ; Farida Hobar, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 98 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ElectroniqueTags : Varistance Coefficient de non linéarité Microstructure Propriétés électriques température de Frittage Varistor Coefficient of nonlinearity Electrical properties sintering temperature الفاريستور معامل اللاخطية المجهرية الخصائص الكهربائية حرارة التلبيد Index. décimale : 621 Electronique Résumé : Varistors are electrical components with variable resistivity depending on the electric field applied to them. These components are typically used in surge protection devices. The objectives of this work are to study the influence of the sintering temperature on the electrical properties of the material as well as to show the advantages and disadvantages compared to a conventional sintering method. To do this, zinc oxide varistors doped with Bi2O3, MnO2, Cr2O3, Sb2O3, Co3O4 and SiO2 were developed by a ceramic method and were sintered for different temperatures (1280, 1300, 1320, and 1350°c). Their characterization was done by DRX, MEB, and I (V). The samples obtained depend strongly on the production conditions (sintering temperature), the more the sintering temperature increases, the more the grain size increases. The grain size of the doped ZnO varistors obtained varies from 2.57 to 6.84 μm. The electrical characterization of these samples shows that they exhibit a non-linear behavior of varistor with a coefficient of 33.61.
In addition, the threshold field is 2991.56v / cm for the temperature of 1280 ° C. These results validate the possibility of miniaturization of varistors for their application in microelectronics.
Diplôme : Doctorat en sciences En ligne : ../theses/electronique/BOU7360.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=11009 Etude, conception et réalisation de capteurs à base de matériaux céramiques. [texte imprimé] / Ahmed Bouchekhlal, Auteur ; Farida Hobar, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2018 . - 98 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ElectroniqueTags : Varistance Coefficient de non linéarité Microstructure Propriétés électriques température de Frittage Varistor Coefficient of nonlinearity Electrical properties sintering temperature الفاريستور معامل اللاخطية المجهرية الخصائص الكهربائية حرارة التلبيد Index. décimale : 621 Electronique Résumé : Varistors are electrical components with variable resistivity depending on the electric field applied to them. These components are typically used in surge protection devices. The objectives of this work are to study the influence of the sintering temperature on the electrical properties of the material as well as to show the advantages and disadvantages compared to a conventional sintering method. To do this, zinc oxide varistors doped with Bi2O3, MnO2, Cr2O3, Sb2O3, Co3O4 and SiO2 were developed by a ceramic method and were sintered for different temperatures (1280, 1300, 1320, and 1350°c). Their characterization was done by DRX, MEB, and I (V). The samples obtained depend strongly on the production conditions (sintering temperature), the more the sintering temperature increases, the more the grain size increases. The grain size of the doped ZnO varistors obtained varies from 2.57 to 6.84 μm. The electrical characterization of these samples shows that they exhibit a non-linear behavior of varistor with a coefficient of 33.61.
In addition, the threshold field is 2991.56v / cm for the temperature of 1280 ° C. These results validate the possibility of miniaturization of varistors for their application in microelectronics.
Diplôme : Doctorat en sciences En ligne : ../theses/electronique/BOU7360.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=11009 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/7360 BOU/7360 Thèse Bibliothèque principale Thèses Disponible
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