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JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) . Vol. CXIV, N° 4Mention de date : 04/2019Paru le : 17/04/2019 |
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Ajouter le résultat dans votre panierEvaluation of chemical products in leather post-tanning process and their influence in presence of neutral salts in raw tannery effluent / M. V. Moreira in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIV, N° 4 (04/2019)
[article]
Titre : Evaluation of chemical products in leather post-tanning process and their influence in presence of neutral salts in raw tannery effluent Type de document : texte imprimé Auteurs : M. V. Moreira, Auteur ; Everton Hansen, Auteur ; G. Giacomolli, Auteur ; F. D. P. Morisso, Auteur ; P. M. Aquim, Auteur Année de publication : 2019 Article en page(s) : p. 108-117 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Caractérisation
Chlorure de sodiumLe chlorure de sodium est un composé chimique de formule NaCl. On l'appelle plus communément sel de table ou de cuisine, ou tout simplement sel dans le langage courant. C'est le principal produit dissous dans l'eau de mer ; on l'appelle alors sel marin.
On l'obtient : dans des marais salants par évaporation de l'eau de mer, dans des mines, par extraction du sel gemme (halite) ou en le synthétisant lors de réactions à hautes températures entre du dichlore (Cl2) et du sodium métallique (Na).
Le chlorure de sodium est utilisé dans l'industrie chimique pour produire du chlore, de la soude caustique et de l’hydrogène.
Chromatographie par échange d'ions
Eaux usées -- Analyse
Post-tannage
Produits chimiques
Spectroscopie d'absorption
Sulfate de sodiumLe sulfate de sodium est un composé chimique courant formé d'un ion sulfate et de deux ions sodium. Lorsqu'il est anhydre, il prend l'apparence d'un solide cristallin blanc de formule chimique Na2SO4. La forme déca-hydratée, Na2SO4·10H2O, est connue sous le nom de sel de Glauber ou mirabilite. Parmi un grand nombre d'usages différents, les principales utilisations du sulfate de sodium concernent la fabrication des détergents et dans le procédé de Kraft de traitement de la pâte à papier. La moitié environ de la production mondiale provient de l'extraction de la forme naturelle décahydratée, et l'autre moitié de productions secondaires dans des procédés de l'industrie chimique.Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : In the leather industry, several chemical products are used for the transformation of the raw hide into the demanded final product. The production flow and the post-tanning of wet-blue leathers may vary according to the available technologies and the type of final item produced. Previous operations and processes are also relevant, particularly the steps of unhairing-liming and tanning process. During the effluent treatment process, there is a great difficulty in removing soluble salts, such as sodium chloride and sodium sulfate in conventional effluent treatment stations. These salts might compromise the biological treatment of tannery wastewater and adversely impact the receiving water bodies, causing environmental pollution. Further, the presence of chlorides and sulfates might interfere in the implementation of the bath reuse system or in the recycling of the treated effluents in the post-tanning process. Therefore, this work aims to investigate the measures used to control the production of sodium neutral salts, such as the sodium chlorides and sulfates, contained in the chemical compounds uses in the industry that performs post-tanning in bovine wet-blue leather, mostly for automotive and furniture upholstery. The work was carried out following the production of the factory for six months, with approximately 1485 whole wet-blue leathers being processed per day, with an average production of 7500 m² of crust leathers per day. The work methodology was based on the diagnosis of the initial situation of the tannery, chemical analyses of the supplies employed and in proposals of action based on this initial profile. The work also involves the checking of the water consumption and the evaluation of the residual baths. The identification of the chemical products in the formulation that contribute directly to the presence of neutral salts in the gross effluent and their presence in the residual baths were among the main results observed in the present work. In order to determinate sodium, chlorides and sulfates, two methodologies were tested (ion chromatography, for chlorides and sulfates ; and absorption spectroscopy, for sodium), showing similar results. Note de contenu : - EXPERIMENTAL : Gathering of production data - Identification and characterization of the main chemical supplies used - Characterization of the critical chemical products regarding the presence of neutral salts - Characterization of the residual baths and water consumption measurements
- RESULTS AND DISCUSSION : Production data - Chemical supplies used in the formulations - Characterization of the critical chemical products regarding the presence of neutral salts - Water consumption - Characterization of the residual bathsEn ligne : https://drive.google.com/file/d/1eNSGuiZwOEvPyZjfpTvEoYbVILy5-ADX/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=32272
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Code-barres Cote Support Localisation Section Disponibilité 20830 - Périodique Bibliothèque principale Documentaires Disponible Characterization of halotolerant bacillus species isolated from salt samples collected from leather factories in Turkey / E. Yilmaz in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIV, N° 4 (04/2019)
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Titre : Characterization of halotolerant bacillus species isolated from salt samples collected from leather factories in Turkey Type de document : texte imprimé Auteurs : E. Yilmaz, Auteur ; Meral Birbir, Auteur Année de publication : 2019 Article en page(s) : p. 118-130 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Bactéries -- Comptage
Bactéries -- Identification
Caractérisation
Contamination microbienne
Cuirs et peaux -- Conservation
Cuirs et peaux -- Séchage
Numération
pH -- Mesure
Sels -- Teneur en humiditéIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : Salt curing is the method most commonly utilized in the leather industry to prevent microbial growth on raw hides/skins. Despite this processing, a wide diversity of microorganisms belonging to Domains Bacteria and Archaea have nevertheless been observed on salted hides/skins. In order to understand whether halotolerant bacterial species in salt contaminate hides/skins during the curing process, 30 salt samples collected from 14 leather factories in Corlu and Tuzla (Turkey) were examined for halotolerant bacteria. Total counts of halotolerant bacterial numbers, pH values and moisture contents of the salt samples were respectively determined between 104 CFU/g and 106 CFU/g, 6.23 and 7.22, 0.90 and 5.02. All isolates were able to grow on both Nutrient Agar Medium without NaCl and Nutrient Agar Medium containing NaCl at concentrations ranging from 2 to 10%. The microorganisms isolated from the samples were identified using phenotypic characteristics and comparative partial 16S rRNA gene sequence analysis. The phylogenetic analysis, using more than 1300 base comparisons of 16S rRNA sequence data, revealed 83 halotolerant isolates that share highly similar identities (97.82-100%) with their closest phylogenetic relatives. These isolates were assigned to 12 different Bacillus species (B. amyloliquefaciens, B.atrophaeus, B.halotolerans, B.licheniformis, B.mojavensis, B.paralicheniformis, B.pumilus, B.safensis, B.siamensis, B.subtilis, B.tequilensis, B.velezensis). We detected catalase and protease activities, as well as production acid from fructose, in all Bacillus isolates. Fifty-five isolates demonstrated positive oxidase activities, and 50 isolates utilized citrate as a sole carbon source. While a fairly high percentage of the isolates produced acid from maltose, almost half of the isolates produced acid from myo-inositol. While 67% of the salt samples contained 1-2 different Bacillus species, 33% of the salt samples contained 3-4 different Bacillus species. Although B.amyloliquefaciens, B.atrophaeus, B.safensis, B.siamensis species were detected at a few salt samples, B.paralicheniformis and B.halotolerans species were detected at more than half of the salt samples. These results uphold the hypothesis that proteolytic halotolerant Bacillus species in the curing salts may contaminate hides/skins during curing process. Hence, we recommend sterilized salts be used in the preservation of the hides/skins to prevent economic losses in the leather industry. Note de contenu : - Salt sample collection
- Detection of total counts of halotolerant bacterial numbers in salt samples and isolation of bacillus strains
- Determination of pH values of the salp samples
- Determination of moisture content of the salt samples
- Examination of mobility of bacillus species
- Gram staining procedure of bacillus isolates
- Endospore staining of bacillus species
- Salt tolerance of bacillus isolates
- DNA extraction and PCR amplification of bacillus isolates
- Oxidase activity of bacillus isolates
- Catalase activity of bacillus isolates
- Protease activity of bacillus isolates
- Citrate utilization by bacillus isolates
- Acid production from maltose, fructose and my-inositol by bacillus isolatesEn ligne : https://drive.google.com/file/d/1d7a8soq83A8ZpWlsxP7y2vaapbUsrRQP/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=32273
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Code-barres Cote Support Localisation Section Disponibilité 20830 - Périodique Bibliothèque principale Documentaires Disponible Quantitative analysis of FITC-trypsin distribution in goatskin matrix / Xuesong Li in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIV, N° 4 (04/2019)
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Titre : Quantitative analysis of FITC-trypsin distribution in goatskin matrix Type de document : texte imprimé Auteurs : Xuesong Li, Auteur ; Deyi Zhu, Auteur ; Zhu Jinzhi, Auteur ; Yanchun Li, Auteur Année de publication : 2019 Article en page(s) : p. 131-137 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Analyse quantitative (chimie)
Cuirs et peaux -- Analyse
Cuirs et peaux de chèvres
Enzymes pancréatiques
Microscopie de fluorescence
TrypsineLa trypsine (EC 3.4.21.4) est une enzyme digestive du suc pancréatique qui a pour rôle de digérer les protéines.
Elle est synthétisée par le pancréas sous forme de trypsinogène (proenzyme inactive), puis stockée dans les vésicules enzymatiques des cellules acineuses d'où elle est excrétée au moment de la digestion. L'activation du trypsinogène en trypsine est le résultat de l'hydrolyse d'un propeptide sous l'action de l'entérokinase ou par un effet d'autoactivation de la trypsine par elle-même. La cholecystokinine-pancréozymine active la sécrétion des enzymes (donc de la trypsine) dans le suc pancréatique.
La trypsine est une endoprotéase qui hydrolyse les liaisons peptidiques dans lesquelles un acide aminé basique (Lys-|-Xaa ou Arg-|-Xaa) engage sa fonction acide (sauf dans le cas où l'acide aminé suivant (schématisé ici par "Xaa") est une Proline). Elle coupe en C-terminal de ces acides aminés. En d'autres mots, elle transforme les chaînes polypeptides en chaînes protéiques plus courtes pour permettre la digestion. Efficace à pH 7,5 - 8,5, elle est inactivée et digérée en quelques heures à pH neutre (=7) dans l'intestin.
La trypsine participe à l'activation d'autres enzymes comme l'alpha-chymotrypsine par coupure hydrolytique de la chaîne polypeptidique du chymotrypsinogène.
Cette enzyme sert également lors de la 2e semaine du développement embryonnaire humain. Elle est sécrétée par le trophoblaste afin de digérer la zone pellucide entourant le blastocyste. Ce phénomène s'appelle l'éclosion.Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The application of enzyme for leather making has attracted much attention in recent years. Therefore, the enzyme diffusion mechanism deserves to be investigated and it is helpful to enzyme application in leather industry. In this study, a novel method basing fluorescence detection technology was developed to achieve quantitative detection of trypsin distribution into goatskin matrix in the model of one-way and turbulent diffusion. In one-way diffusion, trypsin diffusion from the flesh side was faster than that from the grain side. As for turbulent diffusion assay, the trypsin diffusions in grain and flesh layer were directly influenced by the position of goatskin matrix such as back and belly, which could lead to different fluorescence intensity distribution. In addition, the modeling equations, which were fitted with fluorescence intensities, confirmed the quantitation feature in trypsin diffusion process. These results indicated that the method was competent for quantitative detection of enzyme spatial distribution in goatskin matrix. And it would provide the basis foundation for the development of researches in enzyme mass transfer kinetics. Note de contenu : - EXPERIMENTAL : Materials - Pretreatment of goatskin - Preparation of fluorescent trypsin - Experimental apparatuses - Samplkng - Fluorescence microscopy - Quantitative determination - Dseign of formula for quantitative analysis
- RESULTS AND DISCUSSION : Experimental apparatuses - Observation of distribution of FITC-trypsin - Quantitative determination - One-way diffusion analysis - Turbulent diffusion analysisEn ligne : https://drive.google.com/file/d/1t3dTTJNT1yk-sVVdb1dWRn2ouEOWs9rM/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=32274
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Code-barres Cote Support Localisation Section Disponibilité 20830 - Périodique Bibliothèque principale Documentaires Disponible A diverse color-tunable luminous polyurethane leather coating based on long persistent phosphors and photochromic spiropyrans / Saiqi Tian in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIV, N° 4 (04/2019)
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Titre : A diverse color-tunable luminous polyurethane leather coating based on long persistent phosphors and photochromic spiropyrans Type de document : texte imprimé Auteurs : Saiqi Tian, Auteur ; Zhe Sun, Auteur ; Haojun Fan, Auteur ; Jun Yan, Auteur Année de publication : 2019 Article en page(s) : p. 138-145 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Analyse spectrale
Caractérisation
Couleur -- Analyse
Cuir
Fluorescence
Polyuréthanes
Revêtements organiques
SpyropyraneIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : A diverse color-tunable luminous polyurethane leather coating (CLPU) which can reversibly change color as well as fluorescent emission through the UV-vis or UV-darkness circle was prepared, via covalent incorporation of amino-functionalized phosphors and photochromic 1-(2-Hydroxyethyl)-3,3-Dimethylindolino-6’-nitrobenzopyrylospiran (SP). X-Ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis absorption spectra, reflectance spectra, fluorescent spectra as well as the migration percentage were measured to characterize the resultant samples structure and properties. In daylight, CLPU appears white before 365 UV irradiation and violet after UV irradiation, due to the transition of the spiro forms of spiropyran to merocyanine forms. In darkness, CLPU emits intense green light before UV irradiation, and the light changes to orange after UV irradiation, due to the phosphors showing pleasant diverse color-tunable luminous effect. Note de contenu : - EXPERIMENTAL : Materials - Preparation of CLPU - PU and PU/SP preparation - Film and leather preparation - Characterization
- RESULTS AND DISCUSSION : Structure analysis - Coloration and de-coloration process - Fluorescent properties - Diverse color-tunable luminous effect - Thermal migration propertiesEn ligne : https://drive.google.com/file/d/1-LBKUUq7Fx44CKYyVNl40nzYZkTz8UdY/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=32275
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