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Détail de l'auteur
Auteur Jonnalagadda Raghava Rao
Commentaire :
Central Leather Research Institute - Adyar - Chennai - India
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Documents disponibles écrits par cet auteur
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Kinetics of inhibition of type I collagenase by dialdehyde cellulose in stabilization of type I collagen / Gladstone Christopher Jayakumar in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CX, N° 3 (03/2015)
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Titre : Kinetics of inhibition of type I collagenase by dialdehyde cellulose in stabilization of type I collagen Type de document : texte imprimé Auteurs : Gladstone Christopher Jayakumar, Auteur ; Nagarajan Usharani, Auteur ; Arjunan Yasothai, Auteur ; Swarna Vinodh Kanth, Auteur ; Jonnalagadda Raghava Rao, Auteur Année de publication : 2015 Article en page(s) : p. 72-79 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Antienzymes
Cellulose dialdéhyde
CollagénasesLes collagénases sont des enzymes capables de rompre les liaisons peptidiques du collagène. Elles facilitent la destruction des structures extracellulaires lors de la pathogenèse bactérienne. Ce sont des exotoxines.
La production de collagénases peut être induite lors d'une réponse immunitaire, par les cytokines qui stimulent les cellules telles que les fibroblastes et les ostéoplastes et occasionnent indirectement des lésions tissulaires.
Collagène -- StabilitéIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : Collagen is one of the widely studied biomaterial for various industrial applications. However, search of eco-friendly and biocompatible stabilizing agent is a thrust research domain. In this research work, application of dialdehyde cellulose (DAC) was studied to understand the effect on the enzymatic and conformational stability in collagen. The secondary structure of collagen is not significantly altered on interaction with DAC. But, it was found that DAC lead to changes in the amplitude of the circular dichroic (CD) spectrum but did not alter the triple helical conformation of collagen. DAC treated collagen exhibited 93% resistance to collagenolytic hydrolysis. Conversely, DAC treated collagenase exhibited 89% inhibition against collagen degradation and the inhibition was found to be concentration dependent. The kinetics of inhibition of collagenase by DAC was derived from the extent of hydrolysis of (2-furanacryloyl-L-leucyl-glycyl-L-prolyl-L-alanine), FALGPA. DAC exhibited non-competitive mode of inhibition against collagenase. CD data on DAC-modified collagenase substantiate the hypothesis that the inhibition of collagenase by DAC arises from secondary and quaternary structural changes in the enzyme. Gaining new insights in understanding the mechanism of stabilization of collagen by DAC through kinetics of inhibition of collagenase was presented. Note de contenu : - MATERIALS AND METHODS : Materials - Methods - Preparation of DAC - Preparation of crosslinked collagen - Resistance to collagenase - Inhibition of collagenase activity - Kinetic investigation - Inhibition of collagenase by DAC - Conformational changes of DAC stabilized collagen
- RESULTS AND DISCUSSION : Inhibition of collagenase - DAC treated collagenase resistance of native collagen - Conformational changes in DAC stabilized collagen - Conformational changes in DAC treated collagenase - Kinetic analysis of inhibition of collagenase by DAC - Mechanism of inhibition of collagenase by DACEn ligne : https://drive.google.com/file/d/1SE-oSDIEYjm4_Qrm6DaXeblWS7zipi-Z/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=23452
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CX, N° 3 (03/2015) . - p. 72-79[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 17044 - Périodique Bibliothèque principale Documentaires Disponible Lignin based colorant : modified black liquor for leather surface coating application / P. Balasubramanian in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIII, N° 10 (10/2018)
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Titre : Lignin based colorant : modified black liquor for leather surface coating application Type de document : texte imprimé Auteurs : P. Balasubramanian, Auteur ; Sathya Ramalingam, Auteur ; Mohammed Javid, Auteur ; Jonnalagadda Raghava Rao, Auteur Année de publication : 2018 Article en page(s) : p. 311-317 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Calorimétrie
Caractérisation
Colorants
Colorimétrie
Cuirs et peaux -- Finition
Cuirs et peaux -- Teinture
Déchets industriels -- Recyclage
Formulation (Génie chimique)
Fourier, Spectroscopie infrarouge à transformée de
LignineLa lignine est un des principaux composants du bois, avec la cellulose, l'hémicellulose et des matières extractibles. La lignine est présente principalement dans les plantes vasculaires et dans quelques algues. Ses principales fonctions sont d'apporter de la rigidité, une imperméabilité à l'eau et une grande résistance à la décomposition. Toutes les plantes vasculaires, ligneuses et herbacées, fabriquent de la lignine. Quantitativement, la teneur en lignine est de 3 à 5 % dans les feuilles, 5 à 20 % dans les tiges herbacées, 15 à 35 % dans les tiges ligneuses. Elle est moindre pour les plantes annuelles que pour les vivaces, elle est maximum chez les arbres. La lignine est principalement localisée entre les cellules (voir parois pectocellulosiques), mais on en trouve une quantité significative à l'intérieur même de celles-ci. Bien que la lignine soit un réseau tridimensionnel hydrophobe complexe, l'unité de base se résume essentiellement à une unité de phénylpropane. La lignine est le deuxième biopolymère renouvelable le plus abondant sur la Terre, après la cellulose, et, à elles deux, elles cumulent plus de 70 % de la biomasse totale. C'est pourquoi elle fait l'objet de recherches en vue de valorisations autres que ses utilisations actuelles en bois d'œuvre et en combustible.
Voie de biosynthèse : La lignine est une molécule dont le précurseur est la phénylalanine. Cet acide aminé va subir une cascade de réactions faisant intervenir une dizaine de familles d'enzymes différentes afin de former des monolignols. Ces enzymes sont : phénylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), 4-coumarate:CoA ligase (4CL), hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase (HCT), p-coumarate 3-hydroxylase (C3H), caffeoyl-CoA o-methyltransferase (CCoAOMT), cinnamoyl-CoA reductase (CCR), ferrulate 5-hydroxylase (F5H), caffeic acid O-methyltransferase (COMT) et cinnamyl alcohol deshydrogenase (CAD). Dans un certain nombre de cas, des aldéhydes peuvent également être incorporés dans le polymère.
Lumière -- Diffusion
Pigments
Réflectance
Revêtement de surface
Séparation (technologie)
Sol-gel, Procédé
ThermogravimétrieIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : Nowadays, much research is focused towards the development of a value-added products from industrial waste. In this concern, the preparation of pigment colorant with good covering power from the paper and pulp industry waste is less explored within the leather world. The paper and pulp industry generate huge quantity of waste, which is commercially known as black liquor. In order to prepare the pigments with good covering property the black liquor was acidified, and the insoluble organic part of black liquor was used for pigment application. In this work, the structural characterization of the prepared pigment products was analyzed by FT-IR, TGA, DSC, BET, SEM and DLS. Further sol-gel method was employed for the preparation of pigment formulation using the insoluble lignin obtained from the black liquor. The applicability of isolated insoluble as brown pigment was evaluated by using it as pigment for leather surface coating. The color characteristics of the pigment coated leather and checkered card were analyzed by using CIELAB color measurement. The results obtained clearly confirm that the insoluble lignin has potential application as a brown pigment in leather finishing application and is compatible with various auxiliaries employed in leather finishing. Utilization of the prepared brown pigment in leather finishing resulted in upgradation of finished leather through excellent surface covering and in addition, no overloading of grain was observed. Thus, this article provides an approach for converting waste black liquor from paper and pulp industry into a value-added material for pigment application. Note de contenu : - MATERIALS AND METHODS : Separation of lignin based pigment from black liquor - Characterization of separated lignin FT-IR analysis - Thermogravimetric analysis and differential scanning calorimetry - Bruner Emmet Teller (BET) surface area measurements - Scanning electron microscopy - Dynamic light scattering measurement - Pigment formulation for leather finishing application - Mass tone of hiding power of the pigment - Characterization of the finished leather -
- RESULTS AND DISCUSSION : Characterization of the separated insoluble lignin from black liquor - BET surface area measurement - Scanning Electron Microscopic (SEM) analysis - Mass tone of hiding power - Application of lignin based pigment for leather surface coating - Reflectance measurements of pigment coated leather - Determination of fastness propertiesEn ligne : https://drive.google.com/file/d/1sFK4Pd3Z4ogugF6-1ruhcXGdOuI81A4b/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=31090
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXIII, N° 10 (10/2018) . - p. 311-317[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 20280 - Périodique Bibliothèque principale Documentaires Disponible Metal organic based syntan for multi-stage leather processing / Gladstone Christopher Jayakumar in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CX, N° 9 (09/2015)
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Titre : Metal organic based syntan for multi-stage leather processing Type de document : texte imprimé Auteurs : Gladstone Christopher Jayakumar, Auteur ; Sangeetha Subramanian, Auteur ; Kalarical Janardhanan Sreeram, Auteur ; Jonnalagadda Raghava Rao, Auteur ; Balachandran Unni Nair, Auteur Année de publication : 2015 Article en page(s) : p. 288-294 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cuirs et peaux -- Propriétés organoleptiques
MélamineLa mélamine, de nom chimique 1,3,5-triazine-2,4,6-triamine, est parfois dénommée cyanuramide ou cyanurotriamine. Sa formule brute est C3H6N6.
Les "résines mélamine-formaldéhyde" ou "mélamine-formol" (sigle MF) sont appelées "mélamine" dans le langage courant. Elles font partie de la famille des aminoplastes qui regroupe des résines thermodurcissables aminées, issues d'un comonomère tel l'urée ou la mélamine, parfois le thiocarbamide, le cyanamide hydrogène ou le dicyandiamide ; le second comonomère étant le formaldéhyde.
Syntans
Tannage au chrome
Tannage combinéLe tannage combiné se dit des tannages qui allient deux familles ou genre de tannage pour obtenir un résultat additionnant les qualités complémentaires des tannins mis en œuvre par exemple Chrome-Végétal ou Chrome-Synthétique
Tannage organique
Wet-blue (tannage)Peau tannée au chrome (le chrome donne une couleur bleue)Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The leather industry in India and elsewhere have adopted a two stage processing methodology wherein hides/skins are processed up to wet blue in stage one, and subsequently converted to value added products in stage two. The process of rechroming carried out when wet blue leathers are sourced from various vendors thus attains significance. Many tanners prefer to employ chromium based synthetic tanning agents for rechroming, as against basic chromium sulfate, so as to provide for a tanning at higher pH values of above 3.5 – 4.0. Chromium based synthetic tanning agents in addition to employing masked chromium salts also provide for increased fullness to the leather. A significantly large number of these synthetic tanning agents are based on formaldehyde condensed aromatic intermediates, the use of which could result in the presence of free formaldehyde in the crust leathers. Instances of poorer raw material quality also call for the use of melamine-based syntans for preferential filling of the belly regions. In this work, the application of a chromium based melamine syntan devoid of the use of formaldehyde for condensation is reported. The product has been evaluated in tanning, rechroming and post tanning (as a retanning agent). In tanning, the product provides for a shrinkage temperature of 106oC, 3.25-3.75% Cr2O3 content (dry weight) alongside good belly filling. On use in rechroming or post tanning, the product provides for fuller leathers complete with physical properties meeting standard norms. The results indicate that the newly developed product has a significant scope in increasing the cutting value of the leathers by way of providing uniform substance alongside good tanning properties. Note de contenu : - MATERIALS AND METHODS : Materials - Preparation of chrome melamine syntan - Evaluation of the prepared syntan - Physico-chemical evaluation of the leather - Organoleptic properties - Scanning electron microscopy analysis of processed leathers
- RESULTS AND DISCUSSION : Chrome tanned leathers - Rechromed leathers - Wet end finished leathersEn ligne : https://drive.google.com/file/d/15dpG2BTSVuDHRNBt8jYg3g7VcK5mqpct/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=24596
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Code-barres Cote Support Localisation Section Disponibilité 17423 - Périodique Bibliothèque principale Documentaires Disponible Mixed metal complexes of zirconium : A step towards reducing usage of chromium in tanning / Kalarical Janardhanan Sreeram in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIX, N° 3 (03/2004)
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Titre : Mixed metal complexes of zirconium : A step towards reducing usage of chromium in tanning Type de document : texte imprimé Auteurs : Kalarical Janardhanan Sreeram, Auteur ; Rathinam Aravindhan, Auteur ; Balachandran Unni Nair, Auteur ; Jonnalagadda Raghava Rao, Auteur Année de publication : 2004 Article en page(s) : p. 110-118 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The use of chromium(III) salts in tanning is likely to continue. The currently employed tanning methods lead to considerable waste of chromium(III) salts used. There is a need to develop mixed-metal complexes of chromium to reduce the use of chromium in tanning and avoid recovery-reuse methodologies required in conventional chrome tanning. A mixed-metal complex of chromium and zirconium has been developed. The mole ratios of zirconium and chromium in the complex have been optimized to achieve above 100 °C shrinkage temperature, without loss. of leather quality and changes to conventional tanning methods. The developed leathers meet various physical and chemicals characteristics required and also enable reduction in chromium loads in the effluent by 75 % and sulfates load by 50 En ligne : https://drive.google.com/file/d/168hPE-c-idGYzI7LKlUv-aADpl9DupR9/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4185
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCIX, N° 3 (03/2004) . - p. 110-118[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 001599 - Périodique Bibliothèque principale Documentaires Disponible Mixed metal tanning using chrome-zinc-silica : A new chrome-saver approach / N. N. Fathima in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVIII, N° 4 (04/2003)
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Titre : Mixed metal tanning using chrome-zinc-silica : A new chrome-saver approach Type de document : texte imprimé Auteurs : N. N. Fathima, Auteur ; Balachandran Unni Nair, Auteur ; Jonnalagadda Raghava Rao, Auteur ; Balaraman Madhan, Auteur Année de publication : 2003 Article en page(s) : p. 139-146 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Development of newer tanning agents is necessary to overcome the ecological pressure arising from the present tanning methods. Research of such nature will also lead to the evolution of better tanning systems. In the present work, a tanning system based on the mixed metal complexes of chromium, zinc and silica have been prepared. The percentages of chrome, zinc and silica in the tanning system have been optimized based on the properties like hydrothermal stability, physical strength characteristics and percentage exhaustion of chromium. Tanning agents with various ligand environments have been prepared so as to obtain an effective combination for tanning. Hydrothermal stability of the leathers is about 95°C and the percentage exhaustion of chromium is about 90%. The strength and organoleptic properties of the leathers tanned with this new tanning system are on par with and/or better than the conventional chrome tanned system. En ligne : https://drive.google.com/file/d/1f4E4qhU7m1Cegy37PR00lqzYG-DI0BXa/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4116
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Code-barres Cote Support Localisation Section Disponibilité 001586 - Périodique Bibliothèque principale Documentaires Disponible A modified leather processing method for water and pollution reduction in tannery / Subramani Saravanabhavan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIII, N° 1 (01/2008)
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PermalinkA molecular level investigation of dialdehyde starch interaction with collagen for eco-friendly stabilization / Gladstone Christopher Jayakumar in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CX, N° 5 (05/2015)
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PermalinkMolecular level understanding of tanning using an organo-zirconium complex / Balaraman Madhan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVIII, N° 11 (11/2003)
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PermalinkNatural dyeing of leathers using natural materials / Jonnalagadda Raghava Rao in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIII, N° 3 (02/2008)
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PermalinkNatural fibers reinforced chrome shaving composites for sound absorption applications / D. Hemalatha in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIII, N° 11 (11/2018)
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PermalinkNatural sunlight assisted bentonite-ZnO mixed oxide catalyst for organic pollutant removal in leather post tanning wastewater with solar reactor / E. T. Deva Kumar in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIII, N° 8 (08/2018)
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PermalinkNeoteric oxidizing agent for chamois process / Bindia Sahu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIV, N° 9 (09/2019)
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PermalinkA new chromium-zinc tanning agent : a viable option for less chrome technology / Balaraman Madhan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVII, N° 5 (05/2002)
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PermalinkA new leather-making process for meeting eco-label standards : Processing of goatkins / Subramani Saravanabhavan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CI, N° 5 (05/2006)
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PermalinkNon-polar medium enables efficient chrome tanning / Palanisamy Thanikaivelan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXII, N° 10 (10/2017)
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PermalinkA novel approach towards preservation of skins / K. C. Kannan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CV, N° 11 (11/2010)
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PermalinkA novel formaldehyde-free synthetic chrome tanning agent for pickle-less chrome tanning : comparative study on syntan versus modified basic chromium sulfate / Palanisamy Thanikaivelan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVII, N° 4 (04/2002)
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PermalinkPerformance and eco-impact of reverse processed hair sheep gloving leather / Subramani Saravanabhavan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIII, N° 9 (09/2008)
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PermalinkPhysico-chemical and structural studies on leathers tanned using high exhaust basic chromium sulphate salt / Jonnalagadda Raghava Rao in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIII, N° 5 (07/1998)
PermalinkPhytoremediation of soil using Sesuvium Portulacastrum - Part I / Swarna Vinodh Kanth in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIV, N° 1 (01/2009)
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PermalinkPhytoremediation of tannery wastewater treated lands : Part I : accumulation of Na+ and Ci- IN Salicornia Brachiata / P. Ramesh Kannan in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 93, N° 6 (11-12/2009)
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PermalinkPhytoremediation of tannery wastewater treated lands : Part II : Using harvested Salicornia Brachiata plants for the preservation of sheepskins / P. Ramesh Kannan in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 93, N° 6 (11-12/2009)
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PermalinkPolyanionic bio-emulsifier : a heteropolysaccharide based bio-composite for leather post tanning process / Sharmila Selvaraju in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIV, N° 3 (03/2019)
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PermalinkQuality enhancement of low grade wet blue leathers : up-grading of thin substance in the wet end process / K. Gowthaman in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVII, N° 9 (09/2012)
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PermalinkRecovery and reuse of chromium from semichrome liquors / Jonnalagadda Raghava Rao in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVII, N° 3 (03/2002)
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