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Titre : Cheminement du Sélénium dans l’est Algérien. Type de document : texte imprimé Auteurs : Assia Nait Merzoug, Auteur ; Hocine Merazig, Directeur de thèse Editeur : constantine [Algérie] : Université Constantine 1 Année de publication : 2014 Importance : 124 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Chimie: chimie inorganique Sélénium Sélénium plasmatique sélénium Algérie Méthodes de dosage du sélénium Selenium plasmatic selenium selenium Algeria selenium determination السلينيوم تحديد السلينيوم السلينيوم في الجزائر Index. décimale : 540 Chimie et sciences connexes Résumé : Selenium is an antioxidant and a micronutrient for animals and humans. However, the concentration range between deficiency and toxicity is particularly narrow. This allotropic metalloid is indirectly introduced into the food chain through its accumulation in the food and water. However the literature and data on this subject are still limited and incomplete in Algeria. This thesis is focuses on the determination of selenium levels and its routing from soil and water to plants, animals and humans in an eastern region in Algeria. Quantification methods used are the atomic absorption (SAA ET) and mass spectrometry inductively coupled plasma (ICP- MS). The results showed that the soil contains a moderate rate in this trace element. While its content in drinking water does not exceed the Algerian standard and that the population of the target area is not deficient on tis that micronutrient and therefore it doesn’t risk cardiovascular problems due to a deficiency of this element.
Note de contenu : Annexe. Diplôme : Doctorat en sciences En ligne : ../theses/chimie/NAI6504.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9609 Cheminement du Sélénium dans l’est Algérien. [texte imprimé] / Assia Nait Merzoug, Auteur ; Hocine Merazig, Directeur de thèse . - constantine [Algérie] : Université Constantine 1, 2014 . - 124 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Chimie: chimie inorganique Sélénium Sélénium plasmatique sélénium Algérie Méthodes de dosage du sélénium Selenium plasmatic selenium selenium Algeria selenium determination السلينيوم تحديد السلينيوم السلينيوم في الجزائر Index. décimale : 540 Chimie et sciences connexes Résumé : Selenium is an antioxidant and a micronutrient for animals and humans. However, the concentration range between deficiency and toxicity is particularly narrow. This allotropic metalloid is indirectly introduced into the food chain through its accumulation in the food and water. However the literature and data on this subject are still limited and incomplete in Algeria. This thesis is focuses on the determination of selenium levels and its routing from soil and water to plants, animals and humans in an eastern region in Algeria. Quantification methods used are the atomic absorption (SAA ET) and mass spectrometry inductively coupled plasma (ICP- MS). The results showed that the soil contains a moderate rate in this trace element. While its content in drinking water does not exceed the Algerian standard and that the population of the target area is not deficient on tis that micronutrient and therefore it doesn’t risk cardiovascular problems due to a deficiency of this element.
Note de contenu : Annexe. Diplôme : Doctorat en sciences En ligne : ../theses/chimie/NAI6504.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9609 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité NAI/6504 NAI/6504 Thèse Bibliothèque principale Thèses Disponible L’effet du Chlore sur les propriétés électroniques du Sélénium amorphe pur. / Mohamed El Hadi Mansour
Titre : L’effet du Chlore sur les propriétés électroniques du Sélénium amorphe pur. Type de document : texte imprimé Auteurs : Mohamed El Hadi Mansour, Auteur ; Mohamed Lotfi Benkhedir, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2019 Importance : 104 f. Format : 30 cm. Note générale : 1 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : physique: Sciences des Matériaux sélénium photocourant transitoire transport défauts chargés TPC TOF Selenium transient photoconductivity charged defects السيلينيوم الناقلية الضوئية العابرة النقل العيوب المشحونة Index. décimale : 530 Physique Résumé :
Amorphous selenium (a-Se) is an important photoconductive material used as a lightsensitive layer in X-ray digital imaging detectors. The performance of these detectors is determined by the electronic transport properties of the a-Se.
The problem is that pure amorphous selenium is not stable and tends to crystallize at
temperatures near room temperature (~ 40 ° C). The addition of arsenic in small amounts to selenium, less than 1%, on the one hand, hardened material and slowed down crystallization process, but on the other hand affects the transport properties by decreasing the time of life of the holes. This fact is compensated by the addition of a few ppm of chlorine, which ensures the removal of negative charged defects, which present traps for the holes. Our investigation focused on the experimental measurement of photocurrents in chlorine-doped pure a-Se, and on the changes in the density of states (DOS) made by the addition of chlorine. Samples of pure Se doped with 12.5 ppm and 67 ppm of chlorine were prepared in thin films of 10 to 20 μm thick. The transient photocurrent measurements of the carriers were made on the doped samples using current and effective techniques (TPC and TOF), at different temperatures and under different electric fields, and compared by those of pure Se. The addition of a considerable amount of chlorine, in ppm (67 ppm) radically changes the density of localized electronic states of pure Se. The defect at 0.2 eV above the edge of the valence band of pure Se, connected to the change of alternation of the dihedral angle, disappears completely and the defect at 0.45 eV above the edge of the valence band, connected to the D- centres, (negative correlation energy defect) decreases to levels below the detection limit of the technique used. The experimental results have been interpreted in the framework of the multiple trapping conduction model. The TOF traces clearly show that a transient electron photocurrent cannot be measured, this is interpreted by the creation of new D+ centres (electron trap) in the mobility gap, next to the conduction band. On the other side of the valence band, Cl atoms eliminateDiplôme : Doctorat en sciences En ligne : ../theses/physique/MAN7509.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11344 L’effet du Chlore sur les propriétés électroniques du Sélénium amorphe pur. [texte imprimé] / Mohamed El Hadi Mansour, Auteur ; Mohamed Lotfi Benkhedir, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2019 . - 104 f. ; 30 cm.
1 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : physique: Sciences des Matériaux sélénium photocourant transitoire transport défauts chargés TPC TOF Selenium transient photoconductivity charged defects السيلينيوم الناقلية الضوئية العابرة النقل العيوب المشحونة Index. décimale : 530 Physique Résumé :
Amorphous selenium (a-Se) is an important photoconductive material used as a lightsensitive layer in X-ray digital imaging detectors. The performance of these detectors is determined by the electronic transport properties of the a-Se.
The problem is that pure amorphous selenium is not stable and tends to crystallize at
temperatures near room temperature (~ 40 ° C). The addition of arsenic in small amounts to selenium, less than 1%, on the one hand, hardened material and slowed down crystallization process, but on the other hand affects the transport properties by decreasing the time of life of the holes. This fact is compensated by the addition of a few ppm of chlorine, which ensures the removal of negative charged defects, which present traps for the holes. Our investigation focused on the experimental measurement of photocurrents in chlorine-doped pure a-Se, and on the changes in the density of states (DOS) made by the addition of chlorine. Samples of pure Se doped with 12.5 ppm and 67 ppm of chlorine were prepared in thin films of 10 to 20 μm thick. The transient photocurrent measurements of the carriers were made on the doped samples using current and effective techniques (TPC and TOF), at different temperatures and under different electric fields, and compared by those of pure Se. The addition of a considerable amount of chlorine, in ppm (67 ppm) radically changes the density of localized electronic states of pure Se. The defect at 0.2 eV above the edge of the valence band of pure Se, connected to the change of alternation of the dihedral angle, disappears completely and the defect at 0.45 eV above the edge of the valence band, connected to the D- centres, (negative correlation energy defect) decreases to levels below the detection limit of the technique used. The experimental results have been interpreted in the framework of the multiple trapping conduction model. The TOF traces clearly show that a transient electron photocurrent cannot be measured, this is interpreted by the creation of new D+ centres (electron trap) in the mobility gap, next to the conduction band. On the other side of the valence band, Cl atoms eliminateDiplôme : Doctorat en sciences En ligne : ../theses/physique/MAN7509.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11344 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité MAN/7509 MAN/7509 Thèse Bibliothèque principale Thèses Disponible
Titre : Contribution à l'étude de la diffusion des métaux dans les verres à base de sélénium Type de document : texte imprimé Auteurs : Michel Heitzmann ; Philibert, Directeur de thèse ; Université d'Orsay, Éditeur scientifique Année de publication : 1977 Importance : 75 f. Note générale : 1 Disponible au magasin de la bibliothèque centrale Langues : Français (fre) Catégories : Français - Anglais
ElectroniqueTags : Verre Diffusion des métaux Métal Sélénium Index. décimale : 621 Electronique Diplôme : Doctorat En ligne : ../theses/electronique/HIE509.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=2683 Contribution à l'étude de la diffusion des métaux dans les verres à base de sélénium [texte imprimé] / Michel Heitzmann ; Philibert, Directeur de thèse ; Université d'Orsay, Éditeur scientifique . - 1977 . - 75 f.
1 Disponible au magasin de la bibliothèque centrale
Langues : Français (fre)
Catégories : Français - Anglais
ElectroniqueTags : Verre Diffusion des métaux Métal Sélénium Index. décimale : 621 Electronique Diplôme : Doctorat En ligne : ../theses/electronique/HIE509.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=2683 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité HEI/509 HEI/509 Thèse Bibliothèque principale Thèses Disponible
Titre : Cristallisation des couches minces Ge-Se riches en sélénium Type de document : texte imprimé Auteurs : Maryse BAR (Née Esquerre) ; Université de Paris-sud, Éditeur scientifique ; C. Mazières, Directeur de thèse Année de publication : 1976 Importance : 45 f. Note générale : 01 Disponible au magazin de la B.U.C. Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Cristallisation Sélénium Couches minces Ge-Se Index. décimale : 540 Chimie et sciences connexes Diplôme : Doctorat En ligne : ../theses/chimie/BAR1109.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=3835 Cristallisation des couches minces Ge-Se riches en sélénium [texte imprimé] / Maryse BAR (Née Esquerre) ; Université de Paris-sud, Éditeur scientifique ; C. Mazières, Directeur de thèse . - 1976 . - 45 f.
01 Disponible au magazin de la B.U.C.
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Cristallisation Sélénium Couches minces Ge-Se Index. décimale : 540 Chimie et sciences connexes Diplôme : Doctorat En ligne : ../theses/chimie/BAR1109.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=3835 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BAR/1109 BAR/1109 Thèse Bibliothèque principale Thèses Disponible
Titre : L’effet protecteur des antioxydants naturels dans l’intoxication du mercure chez le rat Albinos Wistar : (Aspects biochimiques, immunologiques et histologiques). Type de document : texte imprimé Auteurs : Ahlem Bahi, Auteur ; Youcef Necib, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2015 Importance : 158 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Biochimie appliquee Mercure Huile d’argan Sélénium Stress oxydatif Argania Spinosa antioxydants Mercury Argan Oil Selenium Oxidative Stress antioxidants السلينيوم الإجهاد التاكسدي زيت الأركان الزئبق Index. décimale : 570 Sciences de la vie. Biologie Résumé : The present study aimed to evaluate the protective effect of argan oil and selenium against oxidative stress induced by mercury. For this reason, a phytochemical study of antioxidant tested in vitro was performed on argan oil to estimate its expected effect. The results showed the presence of phenolic compounds in a very high concentration. The evaluation of power scavenger argan oil is more active with IC50 = 13.33 ± 1.3, and in vivo on Albino Wistar rats were treated with mercury alone or combined with argan oil and selenium, for a period of three weeks, the blood is then withdrawn and the rats are sacrificed the various parameters are determined. From the analysis of our results, we observed a significant reduction in weight gain during treatment with mercury alone or combined with argan oil and selenium, but no clear change in the relative weight of liver, kidney or spleen was obtained. The results also showed significant changes in biochemical parameters, immunological and haematological. Characterized primarily by a significant increase in serum glucose, urea, creatinine, uric acid, total and direct bilirubin, total lipids, cholesterol, triglyceride, conjugated diene and the enzymatic activity of AST, ALT, LDH and PAL .dropoff window Whereas serum concentrations of albumin and total protein were reduced in treated rats compared to mercury control animals. Results also show immunological and haematological toxicity especially among the treated groups the pure mercury, an increase in serum IL-1, IL-6 and TNF and elevated white blood cell count, decreased red blood cell levels, hemoglobin concentration the percentage of hematocrit and phagocytic activity during treatment with mercury. Thus the treatment of the rats with the mercury causes a reduction in the plasma antioxidant capacity characterized by decrease in the serum concentration of vitamin E and C and rate of DPPH and thiols. We also observed that the results obtained highlight the detoxifier potential expressed by the decrease in erythrocyte glutathione levels, liver and kidney, metallothionein, the enzymatic activity of the antioxidant system SOD, GPx, GST and catalase and increased in lipid peroxidation expressed by the high levels of plasma MDA, erythrocyte, liver and kidney. Also the results clearly showed substantive alterations of tissue studies in comparison with the control, with hepatocyte cytolysis, hepatic necrosis and tubular degeneration with necrosis of the kidneys. Furthermore supplementation argan oil and selenium changed the toxic effects of mercury and decreased histological alterations and showed that both antioxidants are effective against oxidative stress induced by mercury
Diplôme : Doctorat en sciences En ligne : ../theses/biologie/BAH6696.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9928 L’effet protecteur des antioxydants naturels dans l’intoxication du mercure chez le rat Albinos Wistar : (Aspects biochimiques, immunologiques et histologiques). [texte imprimé] / Ahlem Bahi, Auteur ; Youcef Necib, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2015 . - 158 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Biochimie appliquee Mercure Huile d’argan Sélénium Stress oxydatif Argania Spinosa antioxydants Mercury Argan Oil Selenium Oxidative Stress antioxidants السلينيوم الإجهاد التاكسدي زيت الأركان الزئبق Index. décimale : 570 Sciences de la vie. Biologie Résumé : The present study aimed to evaluate the protective effect of argan oil and selenium against oxidative stress induced by mercury. For this reason, a phytochemical study of antioxidant tested in vitro was performed on argan oil to estimate its expected effect. The results showed the presence of phenolic compounds in a very high concentration. The evaluation of power scavenger argan oil is more active with IC50 = 13.33 ± 1.3, and in vivo on Albino Wistar rats were treated with mercury alone or combined with argan oil and selenium, for a period of three weeks, the blood is then withdrawn and the rats are sacrificed the various parameters are determined. From the analysis of our results, we observed a significant reduction in weight gain during treatment with mercury alone or combined with argan oil and selenium, but no clear change in the relative weight of liver, kidney or spleen was obtained. The results also showed significant changes in biochemical parameters, immunological and haematological. Characterized primarily by a significant increase in serum glucose, urea, creatinine, uric acid, total and direct bilirubin, total lipids, cholesterol, triglyceride, conjugated diene and the enzymatic activity of AST, ALT, LDH and PAL .dropoff window Whereas serum concentrations of albumin and total protein were reduced in treated rats compared to mercury control animals. Results also show immunological and haematological toxicity especially among the treated groups the pure mercury, an increase in serum IL-1, IL-6 and TNF and elevated white blood cell count, decreased red blood cell levels, hemoglobin concentration the percentage of hematocrit and phagocytic activity during treatment with mercury. Thus the treatment of the rats with the mercury causes a reduction in the plasma antioxidant capacity characterized by decrease in the serum concentration of vitamin E and C and rate of DPPH and thiols. We also observed that the results obtained highlight the detoxifier potential expressed by the decrease in erythrocyte glutathione levels, liver and kidney, metallothionein, the enzymatic activity of the antioxidant system SOD, GPx, GST and catalase and increased in lipid peroxidation expressed by the high levels of plasma MDA, erythrocyte, liver and kidney. Also the results clearly showed substantive alterations of tissue studies in comparison with the control, with hepatocyte cytolysis, hepatic necrosis and tubular degeneration with necrosis of the kidneys. Furthermore supplementation argan oil and selenium changed the toxic effects of mercury and decreased histological alterations and showed that both antioxidants are effective against oxidative stress induced by mercury
Diplôme : Doctorat en sciences En ligne : ../theses/biologie/BAH6696.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9928 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BAH/6696 BAH/6696 Thèse Bibliothèque principale Thèses Disponible Permalink
