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Auteur Abdelaziz Boulkamh |
Documents disponibles écrits par cet auteur (4)
Affiner la recherche Interroger des sources externesEude du comportement photochimique de deux herbicides de type halogenophenylurée en solution aqueuse / Abdelaziz Boulkamh
Titre : Eude du comportement photochimique de deux herbicides de type halogenophenylurée en solution aqueuse : le métoxuron et le métobromuron Type de document : texte imprimé Auteurs : Abdelaziz Boulkamh ; Univ. de Constantine, Éditeur scientifique ; M. Sehili, Directeur de thèse Année de publication : 2002 Importance : 151 f. Note générale : 01 Disponible à la salle de recherche
02 Disponibles au magasin de la bibliothèque centraleLangues : Français (fre) Catégories : Français - Anglais
ChimieTags : Laser Photolyse Photocatalyse Metoxuron Métobromuron Toxicité pollution Pesticides Index. décimale : 540 Chimie et sciences connexes Permalink : index.php?lvl=notice_display&id=4074 Eude du comportement photochimique de deux herbicides de type halogenophenylurée en solution aqueuse : le métoxuron et le métobromuron [texte imprimé] / Abdelaziz Boulkamh ; Univ. de Constantine, Éditeur scientifique ; M. Sehili, Directeur de thèse . - 2002 . - 151 f.
01 Disponible à la salle de recherche
02 Disponibles au magasin de la bibliothèque centrale
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Laser Photolyse Photocatalyse Metoxuron Métobromuron Toxicité pollution Pesticides Index. décimale : 540 Chimie et sciences connexes Permalink : index.php?lvl=notice_display&id=4074 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/3682 BOU/3682 Thèse Bibliothèque principale Thèses Disponible 
Titre : Extraction et analyse de contaminants organiques hydrophobes (HAP et PCB) retenus par les déchets plastiques en milieu marin. Type de document : texte imprimé Auteurs : Rafika Bouhroum èp Filali, Auteur ; Abdelaziz Boulkamh, Directeur de thèse Mention d'édition : 09/07/2019 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2019 Importance : 189 f. Format : 30 cm. Note générale : Doctorat 3éme CYCLE LMD.
2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Chimie: Chimie Analytique et Environnement HAPs PCBs POPs débris plastiques mer océan PAHs plastic debris sea ocean الهيدروكربونات العطرية متعددة الحلقات ثنائي الفينيل متعدد الكلور الملوثات العضوية الثابتة الحطام البلاستيكي البحر المحيط Index. décimale : 540 Chimie et sciences connexes Résumé : As they are persistent and bioaccumulative, PAHs (Polycyclic Aromatic Hydrocarbons) and PCBs (Polychlorinated Biphenyls), reported to be toxic or to have a chronic effect in marine organisms, are likely to (i) disrupt the marine ecosystem balance, and (ii) be transmitted from one species to another through the food chain. In this study, the individual concentrations of PAHs and PCBs retained in plastic debris floating in marine waters were determined. Two hitherto unexplored ocean regions were examined. One is nearcoastal (Java Island, Indian Ocean) while the other is in the open sea (Gyre of the North Atlantic Ocean). Analyses revealed that all collected plastic samples contained PAHs and PCBs, which indicates the contamination of both regions. A total of 15 PAHs and 39 PCBs were detected and quantified. Some are highly toxic, such as Benzo [a] pyrene, PCB77 and PCB105 (dioxin-like PCBs, priority substances). Significant differences between the two regions samples, relating to the nature of the components and their concentrations, were revealed. Thus, the mean of the cumulative PAHs' concentrations in the Gyre Polyethylene debris reached 57.7 ng/g, while their Javanese counterparts (Polyethylene and Polypropylene) had an average content 9 times higher. Cumulative PCBs' concentrations observed in debris from the open ocean waters averaged 18.6 ng/g, while coastal debris showed an average concentration 550 times higher, raising much concern. The difference in concentrations of both PAHs and PCBs observed between coastal debris and gyre debris is interpreted by the degradation and/or release of these compounds by ocean
currents, during their transport from the coasts (from where they originate), to distant waters (where they migrate). From the qualitative point of view, gyre's Polyethylene debris were chiefly characterized by heavy PAHs and low-chlorinated PCBs, whereas the coastal polyolefin debris predominantly displayed light PAHs and high-chlorinated PCBs. The pollutant distribution heterogeneity, in samples collected from the same region (Java), but at five different sampling sites, is mainly explained by the different distances separating these sites from human activities, the latter being the main expected source of contamination. Polymer size, its residence time in the marine environment and its age also affect contaminants' adsorption on this polymer. The significant qualitative and quantitative difference of contents between polyethylene samples and polyethylene terephthalate samples, both from the gyre, cannot be fully explained by the difference in the affinity of these polymers for PAHs and PCBs.Note de contenu :
Annaxes.
Diplôme : Doctorat En ligne : ../theses/chimie/BOU7531.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11370 Extraction et analyse de contaminants organiques hydrophobes (HAP et PCB) retenus par les déchets plastiques en milieu marin. [texte imprimé] / Rafika Bouhroum èp Filali, Auteur ; Abdelaziz Boulkamh, Directeur de thèse . - 09/07/2019 . - جامعة الإخوة منتوري قسنطينة, 2019 . - 189 f. ; 30 cm.
Doctorat 3éme CYCLE LMD.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Chimie: Chimie Analytique et Environnement HAPs PCBs POPs débris plastiques mer océan PAHs plastic debris sea ocean الهيدروكربونات العطرية متعددة الحلقات ثنائي الفينيل متعدد الكلور الملوثات العضوية الثابتة الحطام البلاستيكي البحر المحيط Index. décimale : 540 Chimie et sciences connexes Résumé : As they are persistent and bioaccumulative, PAHs (Polycyclic Aromatic Hydrocarbons) and PCBs (Polychlorinated Biphenyls), reported to be toxic or to have a chronic effect in marine organisms, are likely to (i) disrupt the marine ecosystem balance, and (ii) be transmitted from one species to another through the food chain. In this study, the individual concentrations of PAHs and PCBs retained in plastic debris floating in marine waters were determined. Two hitherto unexplored ocean regions were examined. One is nearcoastal (Java Island, Indian Ocean) while the other is in the open sea (Gyre of the North Atlantic Ocean). Analyses revealed that all collected plastic samples contained PAHs and PCBs, which indicates the contamination of both regions. A total of 15 PAHs and 39 PCBs were detected and quantified. Some are highly toxic, such as Benzo [a] pyrene, PCB77 and PCB105 (dioxin-like PCBs, priority substances). Significant differences between the two regions samples, relating to the nature of the components and their concentrations, were revealed. Thus, the mean of the cumulative PAHs' concentrations in the Gyre Polyethylene debris reached 57.7 ng/g, while their Javanese counterparts (Polyethylene and Polypropylene) had an average content 9 times higher. Cumulative PCBs' concentrations observed in debris from the open ocean waters averaged 18.6 ng/g, while coastal debris showed an average concentration 550 times higher, raising much concern. The difference in concentrations of both PAHs and PCBs observed between coastal debris and gyre debris is interpreted by the degradation and/or release of these compounds by ocean
currents, during their transport from the coasts (from where they originate), to distant waters (where they migrate). From the qualitative point of view, gyre's Polyethylene debris were chiefly characterized by heavy PAHs and low-chlorinated PCBs, whereas the coastal polyolefin debris predominantly displayed light PAHs and high-chlorinated PCBs. The pollutant distribution heterogeneity, in samples collected from the same region (Java), but at five different sampling sites, is mainly explained by the different distances separating these sites from human activities, the latter being the main expected source of contamination. Polymer size, its residence time in the marine environment and its age also affect contaminants' adsorption on this polymer. The significant qualitative and quantitative difference of contents between polyethylene samples and polyethylene terephthalate samples, both from the gyre, cannot be fully explained by the difference in the affinity of these polymers for PAHs and PCBs.Note de contenu :
Annaxes.
Diplôme : Doctorat En ligne : ../theses/chimie/BOU7531.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11370 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/7531 BOU/7531 Thèse Bibliothèque principale Thèses Disponible
Titre : Phototransformation de l’acide 5-chlorosalicylique en solution aqueuse et sur cuticule foliaire simulee. Type de document : texte imprimé Auteurs : Radia Tafer, Auteur ; Abdelaziz Boulkamh, Directeur de thèse ; Claire Richard, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2019 Importance : 201 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Chimie: chimie analytique, physique et environnement Phototransformation acide 5-chlorosalicylique éliciteur triplet radicaux hydroxyle 5-chlorosalicylic acid elicitor hydroxyl radicals تحول ضوئي حمض -5كلورو ساليسيليك محفز الدفاع الذاتي للنبات الفئة الثلاثية جذور الهيدروكسيل Index. décimale : 540 Chimie et sciences connexes Résumé :
The photochemical reactivity of 5-chlorosalicylic acid (Cl-C6H3-OH,COOH; 5-ClSA), an elicitor of natural plant defense mechanisms, was examined under different experimental conditions. In neutral aqueous solution and under the action of a simulated solar irradiation (suntest), the monoanionic form (5-ClSA‒) is phototransformed relatively quickly, dechlorination being the predominant primary step. This leads mainly to the respective conjugated bases of 2,5- dihydroxybenzoic acid (DHBA, P3), by photohydrolysis, and 2-carboxy-3-hydroxy-1,4- benzoquinone (P1), by photooxidation. A hydroxylation compound of 5-ClSA‒ (5ClSA-OH) and several dimeric compounds are also formed, but in smaller proportions. The phototransformation of DHBA, experimented separately, leads to the formation of dihydroxycyclopentadiene acid, through a very exceptional ring-contraction reaction. By fusion with P1, DHBA generates a polysubstituted biphenyl and by molecular association with the same P1, a quinhydrone-like complex, via an intermolecular charge transfer, a phenomenon that is just as rarely observed as the contraction of the cycle. About 40 photoproducts, comprising from 19 to 01 C atoms (formaldehyde), diversely oxygenated, comprising aromatic, aliphatic, polycyclic, monocyclic or acyclic compounds, in trace or ultra-trace concentrations, have been identified, revealing the nature of the detectable successive photoproducts, up to quasi-mineralization. The latter was confirmed by measuring the residual content of Total Organic Carbon. The production and involvement of hydroxy radicals (OH•), produced by ""light-induced secondary OH precursors "", in the mineralization of 5-ClSA, has been experimentally proven. The mechanism of photolysis of 5-ClSA, established through the identification of its photoproducts, has been refined by the identification of transient species, at the top of which is the triplet of 5-ClSA, a fleeting species holding nevertheless a central role. The solvated electron, the 2-carboxy-4-chlorophenoxyl radical and the carbene ""4-oxocyclohexa-2,5- dienylidene"" complete the picture. Singlet oxygen (1O2), the corollary of the triplet, was evidenced by phosphorescence. On a leaf model, 5-ClSA, without additives, resists to phototransformation. The presence of a surfactant, added in commercial formulations, considerably accelerates the phototransformation, while orienting it towards reduction. Salicylic acid (SA), the only photoproduct that accumulates, is also a mediator in the response of plants to pathogens.Note de contenu :
Annexes.Diplôme : Doctorat en sciences En ligne : ../theses/chimie/TAF7533.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11372 Phototransformation de l’acide 5-chlorosalicylique en solution aqueuse et sur cuticule foliaire simulee. [texte imprimé] / Radia Tafer, Auteur ; Abdelaziz Boulkamh, Directeur de thèse ; Claire Richard, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2019 . - 201 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Chimie: chimie analytique, physique et environnement Phototransformation acide 5-chlorosalicylique éliciteur triplet radicaux hydroxyle 5-chlorosalicylic acid elicitor hydroxyl radicals تحول ضوئي حمض -5كلورو ساليسيليك محفز الدفاع الذاتي للنبات الفئة الثلاثية جذور الهيدروكسيل Index. décimale : 540 Chimie et sciences connexes Résumé :
The photochemical reactivity of 5-chlorosalicylic acid (Cl-C6H3-OH,COOH; 5-ClSA), an elicitor of natural plant defense mechanisms, was examined under different experimental conditions. In neutral aqueous solution and under the action of a simulated solar irradiation (suntest), the monoanionic form (5-ClSA‒) is phototransformed relatively quickly, dechlorination being the predominant primary step. This leads mainly to the respective conjugated bases of 2,5- dihydroxybenzoic acid (DHBA, P3), by photohydrolysis, and 2-carboxy-3-hydroxy-1,4- benzoquinone (P1), by photooxidation. A hydroxylation compound of 5-ClSA‒ (5ClSA-OH) and several dimeric compounds are also formed, but in smaller proportions. The phototransformation of DHBA, experimented separately, leads to the formation of dihydroxycyclopentadiene acid, through a very exceptional ring-contraction reaction. By fusion with P1, DHBA generates a polysubstituted biphenyl and by molecular association with the same P1, a quinhydrone-like complex, via an intermolecular charge transfer, a phenomenon that is just as rarely observed as the contraction of the cycle. About 40 photoproducts, comprising from 19 to 01 C atoms (formaldehyde), diversely oxygenated, comprising aromatic, aliphatic, polycyclic, monocyclic or acyclic compounds, in trace or ultra-trace concentrations, have been identified, revealing the nature of the detectable successive photoproducts, up to quasi-mineralization. The latter was confirmed by measuring the residual content of Total Organic Carbon. The production and involvement of hydroxy radicals (OH•), produced by ""light-induced secondary OH precursors "", in the mineralization of 5-ClSA, has been experimentally proven. The mechanism of photolysis of 5-ClSA, established through the identification of its photoproducts, has been refined by the identification of transient species, at the top of which is the triplet of 5-ClSA, a fleeting species holding nevertheless a central role. The solvated electron, the 2-carboxy-4-chlorophenoxyl radical and the carbene ""4-oxocyclohexa-2,5- dienylidene"" complete the picture. Singlet oxygen (1O2), the corollary of the triplet, was evidenced by phosphorescence. On a leaf model, 5-ClSA, without additives, resists to phototransformation. The presence of a surfactant, added in commercial formulations, considerably accelerates the phototransformation, while orienting it towards reduction. Salicylic acid (SA), the only photoproduct that accumulates, is also a mediator in the response of plants to pathogens.Note de contenu :
Annexes.Diplôme : Doctorat en sciences En ligne : ../theses/chimie/TAF7533.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11372 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité TAF/7533 TAF/7533 Thèse Bibliothèque principale Thèses Disponible
Titre : Phototransformation d'un fongicide foliaire, le chlorothalonil, dans un solvant mixte eau/acétonitrile. Type de document : texte imprimé Auteurs : Samira Bouchama, Auteur ; Abdelaziz Boulkamh, Directeur de thèse ; Claire Richard, Directeur de thèse Mention d'édition : 17 Avril 2019 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2019 Importance : 135 f. Format : 30 cm. Note générale : 1 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Chimie: Chimie analytique et physique chlorothalonil aqueux photoproduits espèces transitoires oxygène singulet mécanisme réactionnel aqueous photoproducts transient species singlet oxygen reaction mechanism كلوروثالونيل مائي منتجات ضوئية الأنواع العابرة الأوكسجين الأحادي آلية التفاعل Index. décimale : 540 Chimie et sciences connexes Résumé :
Chlorothalonil (CT ; 1,3-dicyano-2,4,5,6-tetrachlorobenzene), a broad-use fungicide, is likely to reach water supplies and contaminate them. Its phototransformation in water, assisted by acetonitrile (ACN) as a co-solvent, was studied under concentration and irradiation conditions close to those prevailing in the environment. It appears that direct photolysis is slow, but accelerated by photoproducts of CT or acetonitrile. The dissolved molecular oxygen acts strongly on the reaction rate, its suppression accelerating the reaction by a factor of 110. Four major photoproducts were identified. Their distribution varies considerably with the concentration of oxygen. In the water-rich medium, the major product is trichloro-1,3- dicyanobenzene (HCT, obtained by substitution of Cl by H). The formation of 4-OHCT (substitution of Cl at position 4 by OH) and CTOOH (removal of Cl, gain of OOH) is substantially favoured by enrichment of the medium with ACN and, in parallel, with O2. Conversely, the deoxygenation of the medium completely cancels the formation of these two products, in favour of CTH and a positional isomer of 4-OHCT, which quantum calculations assign to 2-OHCT. Whatever the conditions prevailing in the reaction medium, dechlorination, with the formation of HCl, is the privileged reaction pathway for degradation of CT and its photoproducts. Transient spectroscopy demonstrated the formation and participation of the triplet excited state of CT (3CT*) and the CTH• radical, derived from the triplet by addition of H, in the CT transformation. The kinetic and spectral characteristics of the triplet were evaluated, as well as the quantum efficiency of the intersystem crossing (ISC). The formation of singlet oxygen (1O2) was established by phosphorescence measurements. The quantum yield of 1O2 production varies from 0.85 (in 100% ACN) to 0.69 (in 30% ACN). In air saturated solutions, the triplet fraction that is trapped by oxygen ranged from 0.88 in pure ACN
to 0.48 in water-acetonitrile (95:5, % v/v). In agreement with the various results, a phototransformation mechanism is proposed. In surface water, one may expect that the disappearance of chlorothalonil will be promoted mainly by the organic compounds that this water contains and that are able of reducing the triplet. Chlorothalonil, in turn, generates high amounts of singlet oxygen, a species that is able of efficiently oxidizing a large number of pollutants in surface water.
Note de contenu :
Annexes.Diplôme : Doctorat en sciences En ligne : ../theses/chimie/BOU7651.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11485 Phototransformation d'un fongicide foliaire, le chlorothalonil, dans un solvant mixte eau/acétonitrile. [texte imprimé] / Samira Bouchama, Auteur ; Abdelaziz Boulkamh, Directeur de thèse ; Claire Richard, Directeur de thèse . - 17 Avril 2019 . - جامعة الإخوة منتوري قسنطينة, 2019 . - 135 f. ; 30 cm.
1 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Chimie: Chimie analytique et physique chlorothalonil aqueux photoproduits espèces transitoires oxygène singulet mécanisme réactionnel aqueous photoproducts transient species singlet oxygen reaction mechanism كلوروثالونيل مائي منتجات ضوئية الأنواع العابرة الأوكسجين الأحادي آلية التفاعل Index. décimale : 540 Chimie et sciences connexes Résumé :
Chlorothalonil (CT ; 1,3-dicyano-2,4,5,6-tetrachlorobenzene), a broad-use fungicide, is likely to reach water supplies and contaminate them. Its phototransformation in water, assisted by acetonitrile (ACN) as a co-solvent, was studied under concentration and irradiation conditions close to those prevailing in the environment. It appears that direct photolysis is slow, but accelerated by photoproducts of CT or acetonitrile. The dissolved molecular oxygen acts strongly on the reaction rate, its suppression accelerating the reaction by a factor of 110. Four major photoproducts were identified. Their distribution varies considerably with the concentration of oxygen. In the water-rich medium, the major product is trichloro-1,3- dicyanobenzene (HCT, obtained by substitution of Cl by H). The formation of 4-OHCT (substitution of Cl at position 4 by OH) and CTOOH (removal of Cl, gain of OOH) is substantially favoured by enrichment of the medium with ACN and, in parallel, with O2. Conversely, the deoxygenation of the medium completely cancels the formation of these two products, in favour of CTH and a positional isomer of 4-OHCT, which quantum calculations assign to 2-OHCT. Whatever the conditions prevailing in the reaction medium, dechlorination, with the formation of HCl, is the privileged reaction pathway for degradation of CT and its photoproducts. Transient spectroscopy demonstrated the formation and participation of the triplet excited state of CT (3CT*) and the CTH• radical, derived from the triplet by addition of H, in the CT transformation. The kinetic and spectral characteristics of the triplet were evaluated, as well as the quantum efficiency of the intersystem crossing (ISC). The formation of singlet oxygen (1O2) was established by phosphorescence measurements. The quantum yield of 1O2 production varies from 0.85 (in 100% ACN) to 0.69 (in 30% ACN). In air saturated solutions, the triplet fraction that is trapped by oxygen ranged from 0.88 in pure ACN
to 0.48 in water-acetonitrile (95:5, % v/v). In agreement with the various results, a phototransformation mechanism is proposed. In surface water, one may expect that the disappearance of chlorothalonil will be promoted mainly by the organic compounds that this water contains and that are able of reducing the triplet. Chlorothalonil, in turn, generates high amounts of singlet oxygen, a species that is able of efficiently oxidizing a large number of pollutants in surface water.
Note de contenu :
Annexes.Diplôme : Doctorat en sciences En ligne : ../theses/chimie/BOU7651.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11485 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/7651 BOU/7651 Thèse Bibliothèque principale Thèses Disponible
