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A novel ester-bonded gemini quaternary ammonium salt with good antimicrobial activity and anti-mold performance for wet blue leather / Tao Zhang in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVII, N° 4 (04/2022)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXVII, N° 4 (04/2022) . - p. 131-140 Titre : A novel ester-bonded gemini quaternary ammonium salt with good antimicrobial activity and anti-mold performance for wet blue leather Type de document : texte imprimé Auteurs : Tao Zhang, Auteur ; Chunhua Wang, Auteur ; Jun Sang, Auteur ; Long Zhang, Auteur ; Yuanhang Xiao, Auteur ; Wei Lin, Auteur Année de publication : 2022 Article en page(s) : p. 131-140 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Ammoniums quaternaires Antifongiques Antimicrobiens Esters Evaluation Toxicologie cellulaire Wet-blue (tannage) Peau tannée au chrome (le chrome donne une couleur bleue) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Herein, we have developed a kind of novel ester-bonded gemini quaternary ammonium salts microbicides named QAS(n+m) for leather application, in which n and m denotes the number of −CH2 between the ester groups on the spacer, and the length of alkyl chain connected to ester groups on the hydrophobic tail chain, respectively. Results indicate that the hydrophobic tail lengths and the spacer lengths in the QAS(n+m) structures affect their antimicrobial activities very differently. QAS(4+10) was used to investigate the antimicrobial mechanism, cytotoxicity, and antimold performance for wet blue leather as it exhibits the strongest antimicrobial effect. It shows QAS(4+10) is capable of inactivating microorganisms mainly by disrupting the integrity of their cell membranes. Compared to commercial leather microbicide product 2-thiocyanomethylthiobenzothiazole (TCMTB), QAS(4+10) exhibits comparable mold resistance and lower toxicity. The present work gives positive insight into the development of novel candidate microbicides for the preservation of wet blue leather. Note de contenu : - MATERIALS AND METHODS : Syntheses of gemini quaternary ammonium salts QAS(n+m) - Antimicrobial activity evaluation - ANTIMICROBIAL MECHANISM STUDY : Scanning electron microscopy (SEM) observation - Determination of K+ and soluble proteins content - Live/dead bacteria staining assay - Cytotoxicity assay ( CCK-8 test) - Anti-mold performance of QAS(4+10) for wet blue leather - RESULTS AND DISCUSSION : Antimicrobial activity evaluation - Antimicrobial mechanism study - Citotoxicity evaluation - Anti-mold performance of QAS(4+10) for wet blue leather - Table 1 : The MIC, MBC and MFC values of QAS(n+m) against different microorganisms - Table 2 : The K+ content and the soluble proteins content in the supernatant of A. niger spores with different treatment DOI : https://doi.org/10.34314/jalca.v117i4 En ligne : https://drive.google.com/file/d/1tpOpnHyYmlv6rkLycYRZXVVVJYwuJ4Cz/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37560 [article]

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Synthesis of multi-site polyether amine triazine derivative for sustainable leather manufacturing / Xinju Jia in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVII, N° 4 (04/2022)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXVII, N° 4 (04/2022) . - p. 141-152 Titre : Synthesis of multi-site polyether amine triazine derivative for sustainable leather manufacturing Type de document : texte imprimé Auteurs : Xinju Jia, Auteur ; Ran Tan, Auteur ; Biyu Peng, Auteur Année de publication : 2022 Article en page(s) : p. 141-152 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Analyse thermique Blancheur Cuirs et peaux -- Propriétés mécaniques Cuirs et peaux -- Propriétés physiques Environnement -- Etudes d'impact Epaisseur -- Mesure Morphologie (matériaux) Polyéther amine triazine Polymères -- Synthèse Potentiel zeta Tannage synthétique Température de retrait Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : In this work, a multi-site polyether amine triazine derivative (ET) was prepared via a one-step process and its structure was confirmed using FT-IR and 1H NMR analyses. Then, the ET was applied to the tanning process and the ET tanning approach optimized and evaluated. The result indicated that after tanning with 8% ET at pH 6 for 6 h, the shrinkage temperature of leather was 83.9°C and the thickness change rate was 97.5%. The XRD, DSC, TG, SEM and Zeta potential analyses demonstrated that ET could couple with the amino groups of the collagen side chains and breaking partial hydrogen bonds between fibers, brought significant improvement to the softness of leather without obvious damage to the high-level structure of collagen. Residual Cl- concentration in the wastewater decreased 42.1% in the tanning process compared to the conventional chrome tanning method. The emissions of COD and TDS in the tanning process reduced by 40.5% and 27.2%, respectively. It is conceivable that the ET tanning approach provides an improved approach to promote leather industry to develop sustainably. Note de contenu : - EXPERIMENTAL : Materials and equipment - Preparation of polyether amine triazine derivatives (ET) - Fourier Transform Infrared Spectroscopy (FT-IR) - Nuclear magnetic resonance spectroscopy (1H NMR) - Leather tanning processing - Determination of the shrinkage temperature - Determination of the exhaustion rate of tanning agent - Determination of the percent thickness increase - Thermal analysis - Zeta potential analyses - Morphological analyses - Whiteness analysis - X-ray diffraction (XRD) measurement - Determination of physical and mechanical properties - Environmental impact assessment - RESULTS AND DISCUSSIONS : Characterization of ET - Optimization of the ET tanning conditions - Optimization of the ET tanning temperature - Optimization of the ET dosage - Zeta potential analysis - XRD analysis - Physical performance leather - Whiteness analysis - Morphology analysis - Environmenta impact assessments - Table 1 : ET tanning process - Table 2 : CTDT tanning process - Table 3 : Tanning effect of different ET dosage - Table 4 : Weight loss in different thermogravimetric stage - Table 5 : Physical performances of leather tanned with different method - Table 6 : Whiteness of wet-white tanned by different methods DOI : https://doi.org/10.34314/jalca.v117i4.4897 En ligne : https://drive.google.com/file/d/1aScYsv5HLo94PmHjL2bri8iHG1jRufx0/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37561 [article]

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Antibacterial properties of several lichen extracts against two moderately halophilic bacteria from salted sheepskins / Ipek Türkmenoglu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVII, N° 4 (04/2022)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXVII, N° 4 (04/2022) . - p. 153-163 Titre : Antibacterial properties of several lichen extracts against two moderately halophilic bacteria from salted sheepskins Type de document : texte imprimé Auteurs : Ipek Türkmenoglu, Auteur ; O. Toksöz, Auteur ; Didem Berber, Auteur ; Pinar Caglayan, Auteur ; Meral Birbir, Auteur ; Nüzhet Cenk Sesal, Auteur Année de publication : 2022 Article en page(s) : p. 153-163 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Antibactériens Bactéries halophiles Cuirs et peaux de moutons Essais (technologie) Extraction (chimie) Extraits de plantes Lichens et constituants Statistique Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : It is well known that possible undesirable defects in finished leathers can result from microbial activities on the salted raw hides/skins during storage. The traditionally used salt curing method can control bacterial activities on the raw stock, but it does not seem possible to completely eliminate microbial attacks. Moderately halophilic bacteria can cause serious damage to hides/skins. From this point of view, potential procedures such as applying new antibacterial agents in the leather industry should be considered. Since some lichen species have been indicated for their promising biological efficacies in the literature; most researchers have focused on their potencies in various fields including leather industry from ancient times. In this study, the bacterial growth of proteolytic and lipolytic Gram-negative moderately halophilic bacteria, Chromohalobacter canadensis (YN6) and Halomonas eurihalina (BL5), from salted sheepskin samples were tested with the extracts of Usnea sp., Plastismatia glauca, Ramalina farinacea, Evernia divaricata, Bryoria capillaris, Hypogymnia tubulosa, Pseudevernia furfuracea and Lobaria pulmonaria. Some of these lichen species were found to be successful to inhibit the bacterial growth of C. canadensis (YN6) and H. eurihalina (BL5). In conclusion, lichen extracts may be utilized in stacked raw hides/skins in tanneries or warehouses to control moderately halophilic bacteria which causes several defects on leather. Note de contenu : - Moderately halophilic test bacteria - Lichen samples - Extraction of lichen samples - Antibacterial tests - Statistical analysis DOI : https://doi.org/10.34314/jalca.v117i4.4898 En ligne : https://drive.google.com/file/d/1JpK270mPD-iuFdcBl9PUzESigAqLbYrc/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37562 [article]

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An ensemble of fine-tuned deep learning networks for wet-blue leather segmentation / Masood Aslam in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVII, N° 4 (04/2022)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXVII, N° 4 (04/2022) . - p. 164-170 Titre : An ensemble of fine-tuned deep learning networks for wet-blue leather segmentation Type de document : texte imprimé Auteurs : Masood Aslam, Auteur ; Tariq M. Khan, Auteur ; Syed Saud Naqvi, Auteur ; Geoff Holmes, Auteur Année de publication : 2022 Article en page(s) : p. 164-170 Langues : Américain (ame) Catégories : Automatisation Evaluation visuelle Qualité -- Contrôle Surfaces -- Analyse Wet-blue (tannage) Peau tannée au chrome (le chrome donne une couleur bleue) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : As part of industrial quality control in the leather industry, it is important to segment features/defects in wet-blue leather samples. Manual inspection of leather samples is the current norm in industrial settings. To comply with the current industrial standards that advocate large-scale automation, visual inspection based leather processing is imperative. Visual inspection of wet-blue leather features is a challenging problem as the characteristics of these features can take on a variety of shapes and colour variations to constitute various normal and abnormal surface regions. The aim of this work is to automatically segment leather images to detect various features/defects along with the background through visual analysis of the surfaces. To accomplish this, a deep learning-based technique is developed that learns to segment wet-blue leather surface features. On our own curated leather images dataset, the proposed ensemble network performed well, with an F1-Score of 74 percent. Note de contenu : - LITERATURE REVIEW - THE PROPOSED METHOD : Data augmentation - Architectures - Ensembling convolutional neural networks - EXPERIMENTAL DESIGN : Dataset - Feature/defect types - Ground truth labelling - Experiment configuration - Quantitative measures - RESULTS : Quantitative comparison - Qualitative comparison - Table 1 : Comparison of the segmentation performance of our proposed method with other state-of-the-art segmentation odels for the wet-blue leather dataset - Table 2 : Class-wise comparison of the segmentation performance of state-of-the-art segmentation methods DOI : https://doi.org/10.34314/jalca.v117i4.4900 En ligne : https://drive.google.com/file/d/1eeGhr_Y_PMJEhoAwWdQfF7edVAP5PF7M/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37563 [article]

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