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Enzymatic dehairing of cattlehide with an alkaline protease isolated from aspergillus tamarii a,b / Daynandan Anandan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIII, N° 10 (10/2008)
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Titre : Enzymatic dehairing of cattlehide with an alkaline protease isolated from aspergillus tamarii a,b Type de document : texte imprimé Auteurs : Daynandan Anandan, Auteur ; William N. Marmer, Auteur ; Robert L. Dudley, Auteur Année de publication : 2008 Article en page(s) : p. 338-344 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : An enzymatic dehairing protocol based on the alkaline serine protease, siolated from the fungus aspergillus tamarii, required 16h, and we observed concomitant grain damage. The use of sodium dodecyl sulfate (SDS) as a preatreatment to remove the lipids from the hide allowed a shortening of the dehairing time to 6h without grain damage. We postulated that the SDS removed all of the sebaceous grease from the pores of the hair facilitating the penetration of the enzyme through the grain layer Using a lypophilic dye, nile red, we showed that SDS did remove some of the grease from the grain side of the hide. By tagging the enzyme with a fluorescent label, we clearly showed, however, that the enzyme penetrated the hide only through its flesh side. The enzymatic dehairing proccess did not remove the fine hairs frome the hide. Adding a common sharpening agent, sodium sulfide, to the liming step removed the fine hairs but also caused grain damage. Employing an auxiliary oxidative dehairing step removed the fine hairs but also caused grain damage. Employing an auxiliary oxidative dehairing step, based on alkaline sodium percarbonate, did remove the fine hairs ; under carefully controlled conditions, grain damage wa not observed. Mechanical data were collected from leather prepared from enzymatically dehaired hide that had been limed, enzymatically dehaired hide that had been further oxidatively dehaired and hide that had been dehaired with sulfide and relimed. The tensile strength of the leather made from enxymatically dehaired and oxidatively treated hide and the leather prepared from the enzymatically dehaired and traditionnaly relimed hide was not significantly different from the control. The leather made from the enzymatically dehaired and oxidatively treated hide, however, was significantly stronger than the leather prepared from the enzymatically dehaired and traditionally relimed hide. En ligne : https://drive.google.com/file/d/1dtUmmk8FB85gUuczxDAnfOackJJ9Nflp/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=2410
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CIII, N° 10 (10/2008) . - p. 338-344[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 010719 - Périodique Bibliothèque principale Documentaires Disponible Interactions between surfactant alkyl sulfo-N-succinimidyl esters and collagen fibrils / C. E. Kung in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. LXXXVIII, N° 1 (01/1993)
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Titre : Interactions between surfactant alkyl sulfo-N-succinimidyl esters and collagen fibrils Type de document : texte imprimé Auteurs : C. E. Kung, Auteur ; B. E. Maleeff, Auteur ; Robert L. Dudley, Auteur ; Paul L. Kronick, Auteur Année de publication : 1993 Article en page(s) : p. 12-24 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : A surface-active agent, sulfo-N-succinimidyl(SSU) was prepared as a probe for collagen-surfactant interactions.When the probe was mixed with monomeric and dimeric collagen in solution, the alfa1 and beta11 chains reacted to give an electrophoretically homogenous product with increased mobility; the mobilities of the alfa2 and beta12 chains were unaltered.The surfactant appeared to coat fibrils of collagen when dried and viewed in the electron microscope.Experimental evidence forthe chemical reactivity of SSU with hippuryllysine under mild conditions was obtained by NMR.Besides serving as a probe for investigations, SSU might also be a model of a permanent leather lubricant requiring minimal amounts of material. En ligne : https://drive.google.com/file/d/1iez6xE3Nn26ryoGo6O9MHzak9Kr-7zhE/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=8243
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. LXXXVIII, N° 1 (01/1993) . - p. 12-24[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 006902 - Périodique Bibliothèque principale Documentaires Disponible Mathematical model of raw hide curing with brine / Eduard Hernà ndez Balada in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIII, N° 5 (05/2008)
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Titre : Mathematical model of raw hide curing with brine Type de document : texte imprimé Auteurs : Eduard Hernà ndez Balada, Auteur ; Robert L. Dudley, Auteur ; Peter H. Cooke, Auteur ; Karel Kolomaznik, Auteur ; William N. Marmer, Auteur Année de publication : 2008 Article en page(s) : p. 167 - 173 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The most common method of preserving raw hides is brine curing with sodium chloride. However, this process has three important disadvantages : first, the length of time that it takes, which is a minimum of 18 hours ; second, the insufficient degree of curing reached in some hides due to an overload and possibly the low efficiency of the brine raceway ; and finally, the environmental impact associated with the discharge of large quantities of electrolytes in the soaking step. Our long term goal is to address all three issues. Initially, we have carried out a study of the salt uptake and its diffusion mechanism in order to attempt a reduction in the curing time. A continuous reaction mathematical model of a closed one dimensional system that describes the diffusion of sodium chloride in the hide during the curing process was chosen in the search for the optimum brine curing conditions such as the optimum brine concentration and percent float. The effect of these two parameters on the values of transport coefficient lambda was reported. Brine diffusion into the hide was tracked by measurement of the chloride concentration of the residual brine solution. In addition, a piece of hide was cured with a fluorescently labeled brine solution and analyzed by means of epifluorescent microscopy for direct visualization of the sodium location within the hide. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=2563
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CIII, N° 5 (05/2008) . - p. 167 - 173[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 010088 - Périodique Bibliothèque principale Documentaires Disponible Oxidative dehairing by sodium percabonate / William N. Marmer in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. C, N° 11 (11/2005)
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Titre : Oxidative dehairing by sodium percabonate Type de document : texte imprimé Auteurs : William N. Marmer, Auteur ; Robert L. Dudley, Auteur Année de publication : 2005 Article en page(s) : p. 427-431 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The dehairing of cattle hides generates large quantities of waste that are of environmental concern as they have a large biological and chemical oxygen demand. We had demonstrated that the traditional dehairing agent, sodium sulfide, can be replaced by an oxidative dehairing agent, sodium perborate, thereby reducing the amount of hazardous chemical in the waste stream. The by-product of perborate is borate, however, which is suspected to accelerate the degradation of wooden dehairing drums. In this paper we report the results of a study that uses sodium percarbonate as the dehairing agent. Although oxidatively dehaired hides exhibit a slight resistance to acid dye uptake, leather produced from percarbonate-dehaired hides in all other studied aspects -- shrinkage temperature, chromium uptake, elongation at break, toughness index -- compared favorably to leather from sulfide-dehaired hides. En ligne : https://drive.google.com/file/d/1glaNJAqIP6k3QpRMjNZpC2rdWmGVtcWZ/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4051
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. C, N° 11 (11/2005) . - p. 427-431[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 003709 - Périodique Bibliothèque principale Documentaires Disponible Rapid oxidative dehairing using alkaline hydrogen peroxide and potassium cyanate : reuse of the dehairing reagents / William N. Marmer in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. C, N° 5 (05/2005)
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Titre : Rapid oxidative dehairing using alkaline hydrogen peroxide and potassium cyanate : reuse of the dehairing reagents Type de document : texte imprimé Auteurs : William N. Marmer, Auteur ; Robert L. Dudley, Auteur Année de publication : 2005 Article en page(s) : p. 165-173 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Studies have continued on rapid dehairing of cattlehide using an oxidative system of alkaline hydrogen peroxide and potassium cyanate. For economic viability, the dehairing mixture needs to be used for more than one dehairing cycle. The number of cycles is dependent upon the residual concentration of the reagents in solution, namely, NaOH, H2O2 and KOCN. The concentrations of these reagents were measured after each dehairing cycle. In addition the solubilized protein concentration and the amount of insoluble material suspended in solution were determined. NaOH, H2O2 and KOCN all decreased with an increase in the number of dehairing cycles. After the 6th or 7th cycle the dehairing times had increased to the point where dehairing still occurred, but was no longer rapid. There was a buildup of, soluble protein in solution as well as suspended (insoluble) material with increasing dehairing cycles. Both the protein and insoluble (mostly hair) material reacted with the dehairing chemicals, resulting in a decrease in the efficacy of the dehairing mixture. Nevertheless, the system appears to offer a viable alternative to sulfide-based rapid dehairing, and further experimentation on a pilot plant scale is merited. En ligne : https://drive.google.com/file/d/1OckTNTPh91tsC3PX1V58kw7OpOUbQZui/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4064
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Code-barres Cote Support Localisation Section Disponibilité 002056 - Périodique Bibliothèque principale Documentaires Disponible Rapid oxidative dehairing with magnesium peroxide and potassium peroxymonosulfate / Andrew G. Gehring in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CI, N° 9 (09/2006)
PermalinkRapid oxidative unhairing with alkaline calcium peroxide / Andrew G. Gehring in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVIII, N° 6 (06/2003)
PermalinkRapid oxidative unhairing with alkaline hydrogen peroxide / William N. Marmer in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVIII, N° 9 (09/2003)
PermalinkThe oxidative degradation of keratin (wool and bovine hair) / William N. Marmer in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CI, N° 11 (11/2006)
PermalinkThe use of oxidative chemicals for the removal of hair from cattle hides in the beamhouse / William N. Marmer in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIX, N° 9 (09/2004)
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