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Dégradation par l'intermédiaire du transfert d'électrons / Shingo Okamoto in EUROPEAN COATINGS JOURNAL (ECJ), N° 11/94 (11/1994)
[article]
Titre : Dégradation par l'intermédiaire du transfert d'électrons : expériences avec des films contenant des pigments de TiO2 et des phtalocyanines à teneur de cuivre Type de document : texte imprimé Auteurs : Shingo Okamoto, Auteur ; Takahiro Tsujita, Auteur ; Teiichi Suzuki, Auteur Année de publication : 1994 Article en page(s) : p. 812-824 Note générale : Bibliogr. Langues : Anglais (eng) Tags : Peinture 'Exposition intempérie' Feuil 'Dégradation 'Transfert électron' Oxygène 'Pigment minéral' 'Titane Oxyde' organique' 'Colorant phtalocyaninique' 'Phtalocyanine métallique' 'Cuivre Complexe' 'Etude expérimentale' 'Spectrométrie RPE' TiO2 Index. décimale : 667.9 Revêtements et enduits Résumé : Parfois on peut observer qu'une dégradation considérable a lieu pendant l'exposition à l'extérieur des films de peinture contenant des mélanges spéciaux de pigments à base de phtalocyanine et du TiO2. En utilisant les techniques de résonance de spin électronique (Electron Spin Résonance ― ESR), on a constaté la formation d'oxygène actif, directement dans le film, généré par le transfert des électrons entre les deux pigments. Sur la base de ces investigations, il a été suggéré que la dégradation du film a lieu comme suite à l'attaque de cet oxygène actif sur le liant. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=11260
in EUROPEAN COATINGS JOURNAL (ECJ) > N° 11/94 (11/1994) . - p. 812-824[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 002498 - Périodique Bibliothèque principale Documentaires Disponible Exterior Durability : II / Zeno W. Wicks in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 71, N° 889 (02/1999)
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Titre : Exterior Durability : II Type de document : texte imprimé Auteurs : Zeno W. Wicks, Auteur ; Frank N. Jones, Auteur ; S. Peter Pappas, Auteur Année de publication : 1999 Article en page(s) : p. 61-69 Note générale : Bibliogr. Langues : Américain (ame) Tags : 'Matériau revêtement' Peinture Durabilité Feuil 'Exposition intempérie' 'Résistance 'Dégradation photochimique' Adjuvant 'Absorbant UV' Antioxydant Amine Pigment Liant 'Polymère chlore' Hydrolyse 'Article synthèse' Index. décimale : 667.9 Revêtements et enduits Résumé : Exterior durability of coatings refers to their resistance to change during outdoor exposure; such changes include changes of modulus, loss of strength, embrittlement, discoloration, loss of adhesion, chalking, loss of gloss, and environmental etching. Thus, both aesthetic and functional properties are involved. The terms outdoor durability and weatherability are also used. This series examines exterior durability, focusing on the most common chemical processes leading to degradation of coatings-photoinitiated oxidation and hydrolysis resulting from exposure to sunlight, air, and water. These processes are interrelated, including enhanced photoxidative degradation in high humidity and enhanced hydrolytic degradation during photoexposure. Furthermore, both processes are accelerated by higher temperatures. Hydrolytic degradation may be enhanced by exposure to acid, as from acid rain. Other atmospheric degradants include ozone and oxides of nitrogen and sulfur. Changes in temperature and humidity may result in cracking, which arises from the expansion and contraction of coatings or substrates. Rates at which these processes occur vary, depending on exposure site(s), time of year, coating composition, and substrate. Note de contenu : - PHOTOSTABILIZATION : UV absorbers and excited state quenchers - antioxidants - Hindered amine light stabilizers - Pigmentation effects
- DEGRADATION OF CHLORINATED RESINS
- HYDROLYTIC DEGRADATIONPermalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=17831
in JOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 71, N° 889 (02/1999) . - p. 61-69[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 003558 - Périodique Bibliothèque principale Documentaires Disponible 009603 - Périodique Bibliothèque principale Documentaires Exclu du prêt Fluorescence and scanning electron microscopic characterization of cuticle erosion in human hair / Sigrid B. Ruetsch in IFSCC MAGAZINE, Vol. 9, N° 1 (01-02-03/2006)
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Titre : Fluorescence and scanning electron microscopic characterization of cuticle erosion in human hair Type de document : texte imprimé Auteurs : Sigrid B. Ruetsch, Auteur ; Yash K. Kamath, Auteur Année de publication : 2006 Article en page(s) : p. 29-35 Langues : Anglais (eng) Catégories : Caractérisation
Cheveux -- Détérioration
Cuticule -- Détérioration
Fluorimétrie
Microscopie électronique à balayageTags : 'Cheveu' 'Exposition environnementale' au toilettage 'Usure du cuticule' 'Caractéristiques phénomène de dommage cheveu' 'Microfluorométrie SEM' Index. décimale : 668.5 Parfums et cosmétiques Résumé : Environmental and natural grooming damage of hair were investigated by the microfluorometric method using Rhodamine B as the fluorescent tracer. An increase in fluorescence intensity of tracer-tagged hair as we moved from the root to middle section and trip end is indicative of weathering and progressive mechanical damage. The locus of Rhodamine B penetration and interaction occurs at the scale edge in the root end, changing to the scale face and scale edge in the middle section, and finally to the cortical cell surfaces and the intercellular cement at the tip end in long hair. The resulting increase in fluorescence emission intensity is indicative of progressive damage to the cuticular structure, ultimately resulting in the loss of the cuticular sheath. Scanning electron microscopic observations show detailed features of progressive cuticle erosion and abltion. Characteristic changes in the physical nature and shape of the cuticle cell compared to its appearance as it emerged from the follicle are indicative of environmental and mechanical damage inflicted upon hair. Change of the smoothly contoured scale edge to its jagged shape, frequent appearance of "failed endocuticular material" left behind after the inextensible A-layer and exocuticle have been chipped away, and "tear lines" or "seams", which are the loci where the surface cuticle cells were orinally attached, are indicative of progressive cuticle erosion. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=10535
in IFSCC MAGAZINE > Vol. 9, N° 1 (01-02-03/2006) . - p. 29-35[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 003890 - Périodique Bibliothèque principale Documentaires Disponible Improving cellular function through modulation of energy metabolism / D. Maes in IFSCC MAGAZINE, Vol. 7, N° 2 (04-05-06/2004)
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Titre : Improving cellular function through modulation of energy metabolism Type de document : document électronique Auteurs : D. Maes, Auteur ; Donald Collins, Auteur ; Lieve Declercq, Auteur ; Reyhaned Foyouzi-Youssefi, Auteur ; David Gan, Auteur ; Thomas Mammone, Auteur ; Edward Pelle, Auteur ; Ken Marenus, Auteur ; Harvey Gedeon, Auteur Année de publication : 2004 Article en page(s) : p. 121-126 Note générale : Bibliogr. Langues : Anglais (eng) Tags : 'Adénosine triphosphate' Energie 'Métabolisme énergétique' Mitochondrie Senescence 'exposition aux UV' Index. décimale : 668.5 Parfums et cosmétiques Résumé : The ambivalent consequences of mitochondrial stimulation on cellular activity have been well established. Mitochondria supply the cell with energy through a process of oxidative phosphorylation but thereby generate free radicals, resulting in the accumulation of hydrogen peroxide in the cytoplasm. We have investigated the impact of cellular senescence as well as UV irradiation, on the balance between these two activities.
The adenosine triphosphate (ATP) level, DNA and protein synthesis in fibroblasts obtained from donors between 30 and 90 years of age appeared to be significantly influenced by the aging process. Both DNA and protein synthesis could be stimulated by increasing intracellular ATP levels. In-vitro senescent fibroblasts showed a reduction in the level of ATP as well as a shift in mitochondrial membrane potential. At the same time, there was an increase in intracellular hydrogen peroxide with increasing population doubling, indicating a clear dysfunction of the metabolic machinery in the mitochondria of senescent cells. To counteract this degradation of the energy pool, we treated cells with creatine, which is known to restore the pool of phosphocreatine in the mitochondria. Creatine treatment significantly increased cell survival after UV exposure, stimulated the repair of UVB-induced DNA damage in keratinocytes and caused a significant reduction in the number of sunburn cells in a UVB-exposed reconstituted skin model. These results clearly indicate that restoration of the energy pool in mitochondria increased cellular self-defense mechanism. These data show the important role played by the mitochondrial energy metabolism on the aging process, and indicate a possible therapy that can be used to counteract this negative effect. Treatment with creatine seems to provide the necessary boost to the cellular metabolism, which leads to an induction of a significant amount of protection and repair to human skin cells.Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=10526
in IFSCC MAGAZINE > Vol. 7, N° 2 (04-05-06/2004) . - p. 121-126[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 003883 - Périodique Bibliothèque principale Documentaires Disponible Occupational exposure to airborne isocyanates during brush/roller application of 2-pack polyurethane paints in a tropical climate / G. DeNola in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 7, N° 2 (03/2010)
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Titre : Occupational exposure to airborne isocyanates during brush/roller application of 2-pack polyurethane paints in a tropical climate Type de document : texte imprimé Auteurs : G. DeNola, Auteur ; J. Kibby, Auteur ; P. J. Hanhela, Auteur ; T. H. Gan, Auteur ; W. Mazurek, Auteur Année de publication : 2010 Article en page(s) : p. 201-208 Note générale : Bibliogr. Langues : Américain (ame) Tags : 'Peinture polyuréthane' Isocyanates Brosse 'Prélèvement air' 'Exposition professionnelle' Rouleau Analyse Index. décimale : 667.9 Revêtements et enduits Résumé : Shipboard and laboratory trials were conducted to determine airborne occupational exposure to isocyanates by brush/roller application of 2-pack polyurethane paints. Airborne concentrations in the breathing zones of the operators were found to be <0.1 µg/m3 during the paint application to a vessel deck, in a tropical climate, in the open air. Similarly, brush/roller application of the paints in an enclosed space generated airborne isocyanate concentrations <3 µg/m3. The dust generated during light sanding of the polyurethane paint, 24 h after curing, did not show detectable levels of isocyanates. DOI : 10.1007/s11998-009-9179-z En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-009-9179-z.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9066
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 7, N° 2 (03/2010) . - p. 201-208[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 012083 - Périodique Bibliothèque principale Documentaires Disponible Prevention of UV-induced skin damage by activation of tumor suppressor genes p53 and p14ARF / Rolf-Dieter Petersen in IFSCC MAGAZINE, Vol. 6, N° 4 (10-11-12/2003)
PermalinkLe thermoformage veut redorer son blason / Michel Queruel in PLASTIQUES & ELASTOMERES MAGAZINE, N° 55-9 (12/2003)
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