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Letteratura scientifica selezionata sul tema "Tannin"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 8 giugno 2024

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Articoli di riviste sul tema "Tannin"

Makkar, H. P. S., M. Blümmel e K. Becker. "Formation of complexes between polyvinyl pyrrolidones or polyethylene glycols and tannins, and their implication in gas production and true digestibility in in vitro techniques". British Journal of Nutrition 73, n. 6 (giugno 1995): 897–913. http://dx.doi.org/10.1079/bjn19950095.

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Various tannin-complexing agentsw have been used to study the potential adverse effects of tannis on rumen metabolism. Using a method based on turbidity formation, the binding of various tannin-complexing agents (polyvinyl polypyrrolidone (PVPP), polyethylene glycol (PEG) of molecular weights 2000 to 35000, and polyvinyl pyrrolidone (PVP) of molecular weight 10000, 40000 and 360000) to tannins (tannic acid, purified tannins from quebracho (Aspidosperma quebracho) and leaves of trees and shrubs (Acioa barteri, Dichostachys cinerea, Guiera senegalensis, Piliostigma reticulatum)) was investigated at different pH values. The binding of all the tannins with PVPP was highest at pH 3–4 and lowest at pH 7. For all the pH range (3–7) studied, the binding of PEG was higher than that of PVP. For all the tannins except tannic acid, the binding to PVP was the same from pH 4·7 to 7. Similar results were observed for the PEG of molecular weight 6000 or higher for all the tannins except quebracho tannins for which the binding increased as the pH increased from 3 to 7. The binding with PEG 2000 decreased to a greater extent as the pH reached near neutral and for PEG 4000 this decrease was slightly lower. Addition of these tannin-complexing agents to the in vitro gas system resulted in higher gas production from tannin-rich feeds (increase varied from 0 to 135%). The PEG were the most effective followed by PVP and PVPP. The PEG 35000 was least effective. The efficiency of other PEG was similar. The PEG 6000 was preferred to PEG 2000 or 4000 as its binding to tannins was higher at near neutral pH values. The gas production increased with an increase in the amount of PEG 6000 up to 0·6 g/40 ml rumen-fluid-containing medium containing 0·5 g tannin-rich feed, beyond which no increase was observed. The percentage increase in gas value at 24 h fermentation correlated significantly with tannin values, the highest correlation (r 0·95) being with protein precipitation capacity of tannins. The increase in gas production was associated with higher production of short-chain fatty acids with little change in their molar proportions, suggesting an increase in organic matter digestibility by inclusion of the PEG in tannin-rich feeds. However, apparent and true digestibilities were lower on addition of the PEG, due to the presence of PEG-tannin complexes in the residues. The use of this bioassay (percentage increase in gas production in the presence of PEG 6000) along with other tannin assays would provide a better insight into the nutritional significance of tannins.

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Yan, Q., e A. Bennick. "Identification of histatins as tannin-binding proteins in human saliva". Biochemical Journal 311, n. 1 (1 ottobre 1995): 341–47. http://dx.doi.org/10.1042/bj3110341.

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Tannins have a number of detrimental biological effects and these include interference with normal growth and metabolism if they are present in the feed of various animals. Proline-rich proteins (PRPs) in saliva have been shown to provide protection against tannin, but little is known about the mechanism of protection and interaction of other salivary proteins with tannin. To identify tannin-binding human salivary proteins, parotid and submandibular/sublingual saliva samples were adsorbed with tannin. PRPs, and in particular a group of low-M(r) proteins, were readily precipitated by tannin. The low-M(r) proteins were purified from parotid saliva and demonstrated to be histatins, a family of well-characterized histidine-rich salivary proteins. The ability of synthetic histatin 5, as well as an acidic PRP (PRP-1) and gelatin to precipitate quebracho condensed tannin and tannic acid was determined. At pH 7.4 histatin 5 was the most effective precipitant of both condensed tannin and tannic acid and it also precipitated the largest amount of condensed tannin at pH 3.0, but the smallest amount of tannic acid at that pH. In contrast PRP-1 showed a greater ability to precipitate both condensed tannin and tannic acid at pH 3.0 than at pH 7.4. Under most circumstances histatin 5 was therefore more effective in precipitating tannins than proteins with high proline content which generally have been recognized as strong precipitants of tannin. Pre-incubation of tannic acid with alpha-amylase inhibited the enzyme, but addition of histatin 5 or the acidic PRP PIF-s protected amylase from inhibition by tannin. Similarly salivary proteins may protect other biological activities in the digestive tract from inhibition by dietary tannin.

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Frank Mayer. "Tannins: Natural plant-derived polyhydroxy phenolic compounds with potential for biotechnological and biomedical applications". World Journal of Biological and Pharmaceutical Research 2, n. 1 (30 gennaio 2022): 001–4. http://dx.doi.org/10.53346/wjbpr.2022.2.1.0127.

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The difference between Tannin and Tannic Acid is that the term Tannin is used to name the group of organic compounds whereas Tannic acid is a type of tannin. Members of the group of Tannins - all of them polyhydroxyphenolic compounds – are present in leaves and other nutrient-rich parts of a huge number of Angiosperm plants. In nature, Tannins play a significant role in the protection of the plants against herbivores. Tannins inactivate enzymes in the digestive tract of the herbivores, with respective consequences: the herbivores may die of starvation. A well-known example for a technological application of Tannins is the process of leather production. Complex formation with collagen the denaturation of proteins - here in the animal skin - by the polyhydroxyphenol components of Tannin is their major function. Various biomedical applications are known, such as application of Tannins due to their adstringent property, production of tannate salts, antihistamines and antitussive drugs. Recently, it was discovered that Tannic acid suppresses the virus SARS-CIY-2 as a dual inhibitor of the main viral protease and the cellular TMPRSS 2 protein, with the consequence that the virus cannot infect human cells.

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Mutiar, Sri, e Anwar Kasim. "Potential and Application of Vegetable Tanning Materials from Industrial Forest Plantation in Indonesia". Journal of Fibers and Polymer Composites 2, n. 1 (31 marzo 2023): 29–45. http://dx.doi.org/10.55043/jfpc.v2i1.62.

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Vegetable tanning materials are sourced from plants that contain tannin compounds. Tannins are obtained through the extraction method from the roots, stems, bark, or fruit of the original plant. There are several forest management companies in Indonesia that produce wood from plant species Acacia auriculiformis and Acacia mangium. Both species are known as Acacia. Acacia is an important source of tannin for material tanner vegetables. This wood is produced as a raw material for the pulp and paper industry. However, the bark contains tannin and has not been used optimally. Therefore, the study's potential and possible applications as vegetable tanning agents have been carried out. The research was started by investigating the availability of bark and extracting tannins to obtain extracts containing tannins. Furthermore, the extract obtained was applied as a vegetable tanning agent for the goatskin tanning process. The results showed that the bark of the Plant Industry Forest has the potential to be developed as a source of tannins for material vegetable tanning agents. The application of acacia bark extract in goatskin tanning has obtained tanned leather that meets the Indonesian National Standard.

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Odenyo, A. A., e P. O. Osuji. "Tannin-tolerant ruminal bacteria from East African ruminants". Canadian Journal of Microbiology 44, n. 9 (1 settembre 1998): 905–9. http://dx.doi.org/10.1139/w98-073.

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Three strains of tannin-tolerant rumen bacteria were isolated from enrichment cultures of rumen microflora of sheep, goat, and antelope and established in medium containing high concentrations of crude tannin extract or tannic acid. These three strains (EAT2, ES3, and EG19), characterized as Selenomonas species, were curved rods, obligately anaerobic, Gram negative, highly motile, and grew in media containing 50 g of tannin extract/L and 50-70 g of tannic acid/L. Strain EAT2 was able to hydrolyze gallic acid, while strains ES3 and EG19 hydrolyzed tannic acid but not gallic acid. All isolates were able to grow in media containing up to 8 g of condensed tannins/L. Growth was very slow when soluble carbohydrate was not added to the medium.Key words: tannin, rumen, bacteria, tannic acid, gallic acid, Selenomonas.

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Mutuku, Maxwell, Jackson Ombui e Arthur Onyuka. "Assessment of Coffee Pulp as a Potential Source of Tannins for Leather Processing". Textile & Leather Review 5 (17 marzo 2022): 132–46. http://dx.doi.org/10.31881/tlr.2021.31.

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The leather industry is experiencing environmental challenges due to pollution associated with chromium tanning. Vegetable tanning is considered as an ecofriendly alternative method. Previous research studies have established that coffee contains 1-10% of tannins. In this study coffee arabica pulp was determined for its tannin content and tanning strength for potential use as a source of tanning material. The hide powder method was used and the tannin content of coffee arabica pulp determined as 5.04% with the tanning strength of 2.26 compared to mimosa which had a tannin content of 63.56% with a tanning strength of 2.82. Both coffee arabica pulp and mimosa exceeded the 1.5 tanning strength recommended for tanning agents. It was concluded that coffee arabica pulp sufficient tanning strength to be used as a tanning material.

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Nyaga, Mwenda, Paul Tanui e Samuel Njenga. "Evaluation of Tamarindus indica L. Seed Tannins". Textile & Leather Review 6 (18 agosto 2023): 373–86. http://dx.doi.org/10.31881/tlr.2023.081.

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Tannins are water-soluble polyphenols mostly found in vascular plants and are important raw materials in many industries like leather, pharmaceuticals, and food and beverages. Tannins protect the plant and help its growth. In this study, Tamarindus indica L. seeds were extracted for the determination of tannin content and the tanning strength by the hide powder method. Earlier studies showed that Tamarindus indica L. seeds varied in the amount of tannins present. Mimosa was used as a control. The tanning strength was 1.73 for the tamarind seed extract and 2.06 for mimosa. The tannin content was >10% for both the tamarind seed extract and mimosa. It was concluded that both tamarind seed extract and mimosa had sufficient tanning strength exceeding (1.5) the minimum recommended for a tanning agent hence providing insights as a feasible material for the tanning process.

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Hernández, Mario Cruz, Juan Carlos Contreras Esquivel, Faustino Lara, Raúl Rodríguez e Cristóbal N. Aguilar. "Isolation and Evaluation of Tannin-degrading Fungal Strains from the Mexican Desert". Zeitschrift für Naturforschung C 60, n. 11-12 (1 dicembre 2005): 844–48. http://dx.doi.org/10.1515/znc-2005-11-1205.

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Eleven fungal strains (4 Penicillium commune, 2 Aspergillus niger, 2 Aspergillus rugulosa, Aspergillus terricola, Aspergillus ornatus and Aspergillus fumigatus) were isolated, characterized morphologically and by their capacity to degrade tannins. Aspergillus niger Aa-20 was used as control strain. Several concentrations of hydrolysable tannin (tannic acid) were used as sole carbon source. All strains were able to degrade hydrolysable tannins. Aspergillus niger GH1 and PSH showed the highest tannin-degrading capacity (67 and 70%, respectively). Also, the fungal capacity to degrade condensed tannin (catechin) was tested. Aspergillus niger PSH and Penicillium commune EH2 degraded 79.33% and 76.35% of catechin. The results demonstrated the capacity of fungi to use hydrolysable and condensed tannins as carbon source.

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Lamy, E., E. S. Baptista, A. V. Coelho e F. Capela e. Silva. "Morphological alterations in salivary glands of mice (Mus musculus) submitted to tannin enriched diets: comparison with sialotrophic effects of sympathetic agonists stimulation". Arquivo Brasileiro de Medicina Veterinária e Zootecnia 62, n. 4 (agosto 2010): 837–44. http://dx.doi.org/10.1590/s0102-09352010000400012.

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In order to study the effects of tannins at histomorphological level, mice were either fed with three structurally different types of tannins (tannic acid, chestnut, and quebracho) or treated with isoproterenol, during 10 days. Acini of parotid and submandibular glands increased significantly, being the increase higher for parotid compared to submandibular glands, and higher in the quebracho compared with the other tannin groups. Sublingual acinar size also increased after tannin consumption, by opposition to isoproterenol-treated animals. The results present evidences that the effects produced by tannins are dependent on their structure.

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Kusumo, Galuh Gondo, M. A. Hanny Ferry Fernanda e Heppy Asroriyah. "Identifikasi Senyawa Tanin Pada Daun Kemuning (Murraya panicullata L. Jack) Dengan Berbagai Jenis Pelarut Pengekstraksi". Journal of Pharmacy and Science 2, n. 1 (7 gennaio 2017): 29–32. http://dx.doi.org/10.53342/pharmasci.v2i1.63.

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ABSTRAKKemuning (Murraya paniculata L. Jack) adalah salah satu kekayaan alam yang memiliki banyak manfaat bagi kehidupan manusia. Tanin merupakan salah satu metabolit sekunder dari kemuning yang dapat digunakan sebagai anti diare dan pelangsing. Ekstrak kemuning didapatkan dari maserasi menggunakan tiga pelarut berbeda, yaitu metanol, etanol dan etil asetat. Tannin kemudian dipisahan dari ekstrak dengan menggunakan kromatografi lapis tipis (KLT) dengan berbagai jenis pelarut. Hasil nalisis menunjukkan bahwa pelarut terbaik untuk mengekstraksi tanin adalah metanol dengan perolehan 23,6989 g (31,59%). Skrining fitokimia yang dilakukan menggunakan dua reagen yang berbeda menunjukkan hasil yang positif mengandung tanin. Eluenterbaik untuk analisa tanin pada penelitian ini adalah dengan n-heksan-etil asetat (6 : 4) dengan nilai Rf sebesar 0,62.Kata Kunci : kemuning (Murraya paniculata L. Jack), tannin, kromatografi lapis tipis (KLT)ABSTRACTOrange Jessamine (Murraya paniculata L. Jack) is one of the natural treasures which has many benefits for human life. Tannin is one of secondary metabolite of orange jessamine that can be used as antidiarrhoeal and body slimming. It was obtained by maceration using 3 different solvents, such as : methanol, ethanol, and ethyl acetate. Tannins was separated from crude extract using thin layer chromatography (TLC) in different type of eluent. The analysis showed that the best solvent to extract tannin is methanol that produce of 23.6989 g (31.59%). The phytochemical screening test of the two reagents shows positif result contain tannin compound. The best eluent in this study aimed is n-hexane: ethyl acetate (6 : 4) with tannin Rf value of 0.62.Keywords: Orange jessamine (Murraya paniculata L. Jack), tannin, maceration, thin layer chromatography

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Più fonti

Tesi sul tema "Tannin"

Garnier, Sandrine. "Rhéologie des tannins polyflavanoi͏̈des industriels et des adhésifs tannin-aldéhyde". Nancy 1, 2002. http://docnum.univ-lorraine.fr/public/SCD_T_2002_0028_GARNIER.pdf.

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Les modules dynamiques de solutions aqueuses d'extraits de tannins polyflavanoi͏̈des commerciaux : mimosa, pin, pécan et quebracho ont été mesurés par rhéométrie en fonction de l'amplitude de déformation et de la fréquence. La gélification et le durcissement des tannins avec le formaldéhyde ont été étudiés par rhéologie. De nouvelles méthodes de calcul ont permis de déterminer les propriétés rhéologiques de la polycondensation tannin-formaldéhyde : point de gel, énergie d'activation, degré de conversion, cinétique et d'analyser les effets de la température, la concentration en durcisseur et la nature du tannin. Les diagrammes TTT et CHT des adhésifs à base de tannins ont été construits pour différents pH et concentrations de formaldéhyde en suivant par analyse thermomécanique le durcissement de la résine in-situ un joint de colle. Des équations corrélant la force de cohésion interne des panneaux de particules à la déflexion minimale mesurée par TMA sur un joint de colle ont été établies
Commercial mimosa, quebracho, pine and pecan polyflavonoid tannin extracts water solutions of various concentrations were examined by rheometry, measuring dynamic moduli as a function of strain amplitude and frequency. Gelling and hardening reactions of tannin extracts with formaldehyde were studied by rheometry. Methods to determine rheological characteristics of tannin-formaldehyde polycondensation reactions before and after gel point were developed. Effect of temperature, influence of hardener concentration and tannin nature on gel point, activation energy, degree of conversion and kinetic were investigated. TTT and CHT curing diagrams of tannin-based adhesives were built for various pH and formaldehyde concentrations, using thermomechanical analysis to follow the hardening of the resin in-situ a wood joint. Regression equations relating the internal bond strength of a particleboard with the inverse of the minimum deflection measured by TMA during cure of a wood joint were obtained

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Auad, Priscila. "Composição química de taninos vegetais, curtimento e propriedades nos couros". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/185808.

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O Brasil é o país que possui o maior rebanho bovino comercial do mundo, e o balanço de exportações de couro vem demonstrando ascensão no número de metros quadrados de couros exportados. No processo produtivo, a etapa de curtimento é de extrema importância para transformar a pele bovina em couros, tornando-a resistente ao ataque de microorganismos, além de conferir enchimento e garantir maior estabilidade hidrotérmica do material. O crescente apelo ambiental pela utilização de materiais renováveis na indústria levou aos taninos vegetais desempenharem papéis importantes como compostos curtentes na indústria coureira. Os taninos são estruturas fenólicas complexas, existindo uma quantidade considerável de parâmetros químicos que podem ser mensurados através de diversas técnicas analíticas. Por outro lado, para os couros, também existem ensaios empregados no produto final, cujo desempenho pode depender do material curtente utilizado. No presente estudo, foram empregados cinco tipos de taninos de maior uso na indústria coureira para avaliação de parâmetros químicos e posterior associação com propriedades nos couros: tanino de acácia, quebracho, castanheiro, mirabolano e tara. Inicialmente, foi realizada uma revisão bibliográfica, a fim de determinar propriedades químicas de maior relevância a serem mensuradas nos taninos no contexto de sua utilização como agentes curtentes. Nesse sentido, elencaram-se os ensaios de determinação de tanantes totais, não-tanantes, sólidos insolúveis, sólidos solúveis, sólidos totais, fenóis totais e massa molecular média para os taninos. Os parâmetros de percentual de sólidos insolúveis, sólidos solúveis não-tanantes e tanantes totais distinguiram bem os grupos de taninos que atravessaram dos que não atravessaram o couro. Assim, pela análise de insolúveis ser a mais simples e direta delas, recomendar-se-ia o seu uso para definir uma faixa de corte para distinguir o desempenho dos taninos no curtimento. A análise de FTIR-UATR foi útil na caracterização e distinção dos taninos nas famílias dos hidrolisáveis e condensados. Os ensaios de temperatura de retração e distensão da flor nos couros também mostraram associação com o atravessamento dos taninos nas peles durante o curtimento. Por fim, a diferença total de cor após exposição à luz UV também foi avaliada para os couros curtidos com os taninos vegetais, sendo que os taninos hidrolisáveis apresentaram uma menor diferença de cor em relação aos condensados.
Brazil is the country with the largest commercial cattle herd in the world, and the balance of exports of leather has shown a rise in the number of square meters of exported leather. In the production process, the tanning step is extremely important to transform the skin into leather, making it resistant to the attack by microorganisms, as well as providing filling and assuring greater hydrothermal stability of the material. The increasing environmental approach for the use of renewable materials in the industry has led to vegetable tannins an important role as tanning compounds in the leather industry. Tannins are complex phenolic structures and there are a considerable amount of chemical parameters that can be measured through various analytical techniques to characterize them. On the other hand, for hides, there are also tests used in the final product, whose performance may depend on the tanning material used. In the present study, five types of tannins highly used in the tanning industry were used for the evaluation of their chemical parameters and later correlation with properties in hides: Black Wattle (Acacia mearnsii), Quebracho (Schinopsis lorentzii), Chestnut (Castanea sativa), Tara (Caesalpinia spinosa) and myrabolan (Terminalia chebula). Initially, a bibliographical review was carried out to determine the most relevant chemical properties to be measured in the tannins in the context of their use as tanning agents. In this context, the assays for the determination of total tannin polyphenols, non-tannin polyphenols, insoluble solids, soluble solids, total solids, total phenols and average molecular weight for tannins were performed. FTIR-UATR analysis was useful in characterizing and distinguishing tannins in their families of hydrolysates and condensates. The Mann-Whitney-U test showed that the insoluble solids, non-tannin polyphenols, soluble solids and total tannin polyphenols percentage distinguished well the groups of tannins that crossed the hide from those that didn´t. Hence, once the analysis of insoluble solids is the simplest and the most direct of them, it would be recommended to use this parameter to define a cutting range to distinguish the performance of tannins in leather tanning. The shrinkage temperature and distension tests in the leather also showed association with the leather cross-sectional results during tanning baths. Finally, the total color difference after exposure to UV light was also evaluated for the tanned hides with the vegetable tannins, and the hydrolysable tannins presented a smaller color difference or greater light fastness in comparison to the condensates.

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Wu, Jiacheng, Guoqiang Ning, Jinwei Zhang e Wuyong Chen. "Ti (III)-tannin combination tanning technology based on microwave irradiation - 76". Verein für Gerberei-Chemie und -Technik e. V, 2019. https://slub.qucosa.de/id/qucosa%3A34274.

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Content: Microwave is a fast, efficient and energy-saving thermal resource, hence an attempt has been made for applying this technology in the combination tanning using titanium (III) and tannin extracts. In this work, the microwave effects on the complex reaction of Ti (III) with tannin extracts and leather products properties were investigated. The precipitation condition was used to characterize the complexation degree between Ti (III) and tannin extracts. And the shrinkage temperature, tear strength, SEM, DSC, TG, FT-IR, and histological structure were used to characterize the changes in the physical and chemical properties of the combined tanned leather. Take-Away: The results showed that microwave irradiation can accelerate the complex reaction of Ti (III) with tannin extracts. At the room temperature, the mixture of tannin and titanous sulphate kept stable at pH 3-4. In addition, microwave could increase the shrinkage temperature, tear strength, thermal stability, and fibrage of Ti (III)-tannin tanned leather, and it would not change the combination mode of the skins with tanning agents as well as the hierarchical structure of collagen. Therefore, these results inferred that microwave could promote the reaction between Ti (III) and tannins and the combination of tannins with collagen, which may provide a theoretical basis for the application of microwave in Ti (III)-tannin combination tanning technology.

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Oliveira, Franciéli Borges de. "Utilização de matéria-prima obtida de fonte renovável na preparação de compósitos de matriz tipo fenólica". Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/75/75131/tde-13102008-143432/.

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A matéria-prima utilizada na produção em larga escala de resinas fenólicas (normalmente fenol e formaldeído) é obtida a partir de fontes não renováveis. O tanino e o furfural, originados de fonte renováveis, apresentam a possibilidade de substituir parcialmente o fenol e formaldeído, respectivamente, na preparação de resinas fenólicas, formando uma rede integrada baseada em unidades de fenol/tanino e fenol/furfural para as resinas taninofenólica e fenol-furfural, respectivamente. No presente trabalho, estas resinas foram utilizadas na preparação de compósitos, os quais foram reforçados com fibras lignocelulósicas (sisal). As resinas taninofenólica e fenol-furfural foram caracterizadas por Ressonância Magnética Nuclear (RMN). Para análise da resina fenol-furfural, compostos modelo foram previamente sintetizados e avaliados por RMN 1H e 13C. Fibras de sisal foram usadas como agente de reforço das matrizes termorrígidas do tipo fenol, tendo em vista as excelentes propriedades mecânicas que esta fibra apresenta, assim como a disponibilidade da mesma no país, pois o Brasil é atualmente o maior produtor mundial desta fibra. Foram utilizadas fibras de sisal (3,0 cm de comprimento) em porcentagens diversas, sem tratamento e mercerizadas (tratamento com solução alcalina). Foram utilizadas também fibras tratadas com ar ionizado e reagidas com tanino hidroximetilado, variando-se o tempo de exposição das fibras ao tratamento. Os compósitos preparados com resina taninofenólica, contendo fibras de sisal tratadas (mercerização, ar ionizado e tanino hidroximetilado), apresentaram uma diminuição no valor de resistência ao impacto, quando comparados aos compósitos preparados com fibras de sisal sem tratamento. Provavelmente, estes tratamentos degradaram as fibras de sisal, tornando-as mais frágeis. As análises de microscopia eletrônica de varredura (MEV) destes compósitos reforçados com fibras tratadas, mostraram uma maior adesão entre fibra e matriz. Este aumento da adesão na região da interface foi confirmado pelos resultados obtidos nos testes de absorção de água, em que os compósitos contendo fibras de sisal mercerizadas absorveram no geral menores quantidades de água, confirmando que os tratamentos aplicados na fibra diminuíram o caráter hidrofílico característico das fibras de sisal sem tratamento. Os parâmetros obtidos a partir das curvas de absorção de água, revelaram que a difusão das moléculas de água no interior dos compósitos segue o regime fickiano. Para os compósitos de matriz fenol-furfural, a fim de avaliar os efeitos da natureza dos álcalis utilizados na propriedade destes compósitos, as resinas foram preparadas usando como catalisadores KOH e K2CO3, sendo na seqüência aplicadas na preparação de compósitos reforçados com fibras de sisal (3,0cm, 30% em massa, não tratadas). As análises de MEV mostram que a adesão na interface fibra/matriz é mais intensa quando KOH é utilizado, se comparado a K2CO3. Essa baixa adesão é provavelmente devido a possível liberação de CO2, quando K2CO3 é usado, que pode promover o surgimento de microcavidades em torno das fibras, o que pode levar a baixa adesão fibra/matriz. Essa baixa adesão se reflete na propriedade de resistência ao impacto, pois para os compósitos preparados com KOH os valores foram superiores. Ainda, para verificar se a resina obtida usando KOH pode ser preparada a partir de condições mais suaves, um experimento foi realizado com menores tempos de reação e temperatura. A resistência ao impacto deste compósito mostrou que um material com boas propriedades pode, ser obtido quando as resinas são preparadas nestas condições. Os resultados obtidos são promissores, e mostram que compósitos com boas propriedades podem ser preparados usando altas proporções de materiais obtidos de biomassa, isso é, fibras de sisal, tanino e furfural.
In the present work phenolic type matrices were prepered, which were reinforced with lignocellullosic fibers (sisal). The tannin-phenolic and phenol-furfural resins, amid other techniques, were characterized by nuclear magnetic resonance (NMR). Model compounds were synthesized specially for the 1H and 13C NMR analysis of phenol-furfural resins. The sisal fibers were chosen as reinforcing agent of the phenol-type thermoset matrices, due to their excellent mechanical properties, as well as the availability of this lignocellulosic material in Brazil, which is currently the greater world-wide producer of these fibers. Several percentages of unmodified and alkali treated (mercerized) fibers (3.0 cm length, randomly distributed) were used. Up to 50% of fibers (w/w), the impact strength of the composites improved with increase in the fiber content. In addition, fibers treated with ionized air and with hydroxymethylated tannin, varying the time exposure of the fibers to the treatments, were used. The tannin-phenolic matrices composites reinforced with 30 % (w/w) of modified sisal fibers (mercerized, treated with ionized air and hydroxymethylated tannin), showed lower impact strength than reinforced with sisal unmodified fibers. Probably, the sisal fibers were partially degraded by these treatments, turning them more fragile mechanically. The scanning electron microscopy (SEM) images of the composites reinforced with modified fibers showed better adhesion between fiber and matrix, confirmed by the results obtained from the water absorption experiments, where the composites reinforced with modified sisal fibers absorbed, in general, lesser amounts of water, indicating that the treatments applied in the fiber decreased the hydrophilic character of the fibers. The parameters obtained from the curves of water absorption revealed that the diffusion of water molecules within of the composites follows the Ficks law. Concerning the phenol-furfural resins, to evaluate the effect of the nature of the alkali used in the properties of the related composites, the resins were prepared using KOH and K2CO3 as catalysts, and then used in the preparation of composites reinforced with unmodified sisal fibers (3.0 cm length, 30% w/w, randomly distributed). The SEM images showed that the adhesion in the interface fiber/matrix was improved when KOH is used, instead of K2CO3. This low adhesion between fiber/matrix is probably caused by microcavities located around the fibers and possibly generated by CO2 release when K2CO3 is used in the preparation of the resin. This low adhesion reflects in the property of impact strength, for the composites prepared with KOH the values were superior. Nevertheless, to verify if the resin obtained using KOH can be prepared from softer conditions, a resin was prepared using lower reaction times (1h, instead of 3:15h) and temperature (70 °C, instead of 130 °C). The impact strength of the composite obtained from this resin showed that a material with good properties was obtained. Overall, the results are promising and indicate that composites with good properties can be prepared using high proportion of materials obtained from biomass, i.e., sisal fiber, tannin and furfural.

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Sanchez, Lucero Manuel. "Extraction of jojoba tannins and their role in protein-tannin complex formation and digestive proteases inhibition". Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184405.

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Jojoba albumins and globulins were treated with jojoba tannins to study the protein-tannin complex formation. Trypsin and chymotrypsin were also treated with jojoba tannins to determine the change of enzymatic activity. The treated albumins and globulins were fractionated by gel filtration before and after treatment. Two albumin fractions did not appear after treatment, but a new fraction appeared with a shorter elution time. A precipitate was formed by addition of jojoba tannins to the jojoba globulins, and two globulin fractions did not appear after treatment. Trypsin was completely inhibited by 5.80 μg of tannin/ml. Chymotrypsin was completely inhibited by 36.44 μg of tannin/ml. Seven two-hour successive extractions with methanol were sufficient to obtain a jojoba meal which, when mixed at 15% in a ration with soybean, resulted in excellent growth of mice. Detannification of jojoba meal with methanol and acid methanol extracted other toxicants, because mice fed 15% of this jojoba meal gained more weight than the control. Acid methanol extraction was more effective than methanol or aqueous extraction in removing tannins; water extracted more protein and less tannin.

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Chen, Yumin. "Oxidation of Polymeric Polyphenols (Tannins) in Biologically Relevent Systems". Miami University / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=miami1089232925.

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Navarrete, Fuentes Paola Jeannette. "Adhésifs naturels à base de tannin, tannin/lignine et lignine/gluten pour la fabrication de panneaux de bois". Thesis, Nancy 1, 2011. http://www.theses.fr/2011NAN10089/document.

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Lors de cette étude, différentes recherches ont été effectuées sur l'utilisation de divers matériaux naturels comme source de matière premières pour la fabrication de colles vertes pour l'industrie de panneau. Dans ce contexte, le travail a consisté à : (i) Evaluer le potentiel de différents tannins en provenance de déchets d'écorces et développer des colles à base de tanins avec différents durcisseurs.(ii) Evaluer le potentiel de lignines de différentes origines et développer des colles à base de tannin de mimosa et de lignine. (iii) Développer des colles à base de tannin et de protéine de gluten.(iv) Evaluer les émissions de formaldéhyde et d'autres composés organiques volatiles (COV) à partir de panneaux de particules fabriqués avec les colles naturelles mises au point précédemment.Les techniques d'analyses thermomécaniques, de spectroscopie CP-MAS 13C NMR, de matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF) et de temps de gel ont été utilisées comme méthodes de travail pour l'évaluation et la caractérisation de ces colles. Les essais de cohésion interne pour l'évaluation de la résistance mécanique de la colle selon la norme EN -312 ont également été effectués.En ce qui concerne les émissions de formaldéhyde et des autres COV à partir de panneaux contentant des colles vertes, le recours à des techniques normalisées par chromatographie en phase gazeuse associée à un spectromètre de masse (GC-MS) et par chromatographie en phase liquide (HPLC) ont été privilégiées
This study deals with some researches carried out about the use of various natural materials as a source of raw material for the manufacturing of green adhesives for the industry of panel. In this context, work consisted in:(i) Evaluation of the potential of various tannins coming from barks wastes and development of adhesives containing tannins and various hardeners.(ii) Evaluation of the lignin potential from various origins and development of adhesives containing tannin from mimosa and lignin.(iii) Development of adhesives containing tannin and gluten protein.(iv) Evaluation of formaldehyde and other volatile organic compounds (VOC) from particleboards manufactures with the natural adhesives previously developed.Thermomechanical analyses, spectroscopy CP-MAS 13C NRM, matrix- assisted laser desorption/ionization mass spectroscometry (MALDI-TOF) and gelling time techniques were performed for evaluation and characterization of these adhesives. Internal bond test for the evaluation of adhesives mechanical resistance according to the standard EN-312 were also carried out.Concerning formaldehyde and other VOC emissions from panels with green adhesives, the recourse to standardized techniques which are gas chromatography associated with a mass spectrometer (GC-MS) and high performance liquid chromatography (HPLC) were privileged

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Navarrete, Fuentes Paola Jeannette. "Adhésifs naturels à base de tannin, tannin/lignine et lignine/gluten pour la fabrication de panneaux de bois". Electronic Thesis or Diss., Nancy 1, 2011. http://www.theses.fr/2011NAN10089.

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Glyphis, John Paul. "Herbivory and tannin polyphenols in mediterranean ecosystems". Thesis, University of Cape Town, 1985. http://hdl.handle.net/11427/23167.

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Albertz, Megan Lee. "Isolation and Characterization of Protein-Tannin Complexes". Miami University Honors Theses / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=muhonors1209128363.

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Libri sul tema "Tannin"

Rao, V. S. Sundara. Vegetable and synthetic tanning materials. Madras: Indian Leather, 1991.

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Jansen, P. C. M. 1943- e Plant Resources of Tropical Africa (Program), a cura di. Dyes and tannins. Wageningen, Netherlands: PROTA Foundation, 2005.

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Jansen, P. C. M. 1943- e Plant Resources of Tropical Africa (Program), a cura di. Dyes and tannins. Wageningen, Netherlands: PROTA Foundation, 2005.

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Ellis, R. P. Tannin-like substances in grass leaves. A cura di Leistner O. A e Momberg B. A. Pretoria, South Africa: National Botanical Institute, 1990.

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Yan, Qingyou. Identification of tannin-binding proteins in human saliva. [Toronto: Faculty of Dentistry, University of Toronto], 1995.

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Yan, Qingyou. Identification of tannin-binding proteins in human saliva. Ottawa: National Library of Canada, 1994.

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Marzocca, Angel. Index de plantas colorantes, tintóreas y curtientes: Manual de las especies de Argentina. Buenos Aires: [Academia Nacional de Agronomía y Veterinaria], 1993.

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Nacro, Mouhoussine. Plantes tinctoriales et plantes à tanins du Burkina Faso: Mouhoussine Nacro, Jeanne Millogo-Rasolodimbi ; illustration, Passari Y. Oulla. Amiens: ScientifikA, 1993.

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Sumardi, Sumadiwangsa, a cura di. Tanin bakau sebagai perekat papan partikel =: Mangrove tannins as particleboard adhesive. Bogor, Indonesia: Pusat Penelitian dan Pengembangan Hasil Hutan, 1985.

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Tanni. London: CollinsWillow, 1996.

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Capitoli di libri sul tema "Tannin"

Bährle-Rapp, Marina. "Tannin". In Springer Lexikon Kosmetik und Körperpflege, 545. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71095-0_10329.

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Gooch, Jan W. "Tannin". In Encyclopedic Dictionary of Polymers, 730. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_11555.

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Neelabh. "Tannin". In Encyclopedia of Animal Cognition and Behavior, 1–2. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-319-47829-6_363-1.

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Neelabh. "Tannin". In Encyclopedia of Animal Cognition and Behavior, 6855–57. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-319-55065-7_363.

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Makkar, Harinder P. S. "Tannin Bioassay". In Quantification of Tannins in Tree and Shrub Foliage, 75–81. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-0273-7_11.

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Hagerman, Ann E. "Tannin—Protein Interactions". In ACS Symposium Series, 236–47. Washington, DC: American Chemical Society, 1992. http://dx.doi.org/10.1021/bk-1992-0506.ch019.

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Schultz, Jack C. "Tannin-Insect Interactions". In Chemistry and Significance of Condensed Tannins, 417–33. Boston, MA: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4684-7511-1_26.

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Pizzi, Antonio. "Tannin Structure and the Formulation of Tannin-Based Wood Adhesives". In Plant Polyphenols, 991–1003. Boston, MA: Springer US, 1992. http://dx.doi.org/10.1007/978-1-4615-3476-1_60.

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Pizzi, Antonio. "Tannin Autocondensation and Polycondensation for Zero Emission Tannin Wood Adhesives". In Plant Polyphenols 2, 805–21. Boston, MA: Springer US, 1999. http://dx.doi.org/10.1007/978-1-4615-4139-4_45.

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Kreibich, Roland E. "Tannin-Based Wood Adhesives". In Chemistry and Significance of Condensed Tannins, 457–78. Boston, MA: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4684-7511-1_29.

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Atti di convegni sul tema "Tannin"

Iordache, Ovidiu, Ioana-Corina Moga, Elena-Cornelia Tănăsescu, Elena Perdum, Lucia Secăreanu, Mihaela-Cristina Lite, Irina-Mariana Săndulache e Elena-Laura Troancă. "Reduction of Residual Tannins Concentration Using Cerioporus squamosus Bio-Augmented Polymeric Carriers". In The 9th International Conference on Advanced Materials and Systems. INCDTP - Leather and Footwear Research Institute (ICPI), Bucharest, Romania, 2022. http://dx.doi.org/10.24264/icams-2022.ii.9.

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The oldest use of polyphenols in the leather industry is based on their ability to stabilize collagen in the skin against rotting. Leather tanning processes are among the most polluting industrial sources in terms of undesirable and toxic parameters (COD, BOD, content of tannic acids, fats, sulphureous residues, chloride, chromium, suspended solids etc.). Tannic acid is a naturally occurring phenolic compound and is widely used in the tanning processes, being one of the main pollutants in leather industry derived wastewaters. Current paper explored the ability of HDPE carrier, functionalized with Cerioporus squamosus microbial strain, to reduce the residual concentration of five natural tannins, widely used in the tanning processes in leather industry: Quebracho, Chestnut, Mimosa, Myrobalan and Gambier, in concentration of 1% in the tested solution. Bio-augmentation experiment of the HDPE structures were carried out in an experimental laboratory installation, and treatment of each aqueous solution, was carried out for 7 straight days, and percentage reduction of residual tannins was calculated at 3 and 7 days. Results highlighted varying degrees of reduction of the residual tannin concentration in the solutions, depending on the tannin tested, the best efficiency being achieved against Myrobalan tannin, with a maximum percentage reduction in residual concentration of 41% after 7 days, followed by Mimosa tannin (34%-7 days), Quebracho (28%-7 days), Chestnut (22%-7 days) and Gambier (9.30%-7 days).

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Sendrea, Claudiu, Maria-Cristina Micu, Emanuel Hadimbu, Simona Maria Paunescu, Iulia Maria Caniola, Madalina Ignat, Lucretia Miu e Elena Badea. "Micro DSC and NMR MOUSE studies of collagen–vegetable tannin interaction mechanism during leather making". In The 8th International Conference on Advanced Materials and Systems. INCDTP - Leather and Footwear Research Institute (ICPI), Bucharest, Romania, 2020. http://dx.doi.org/10.24264/icams-2020.v.13.

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In this study NMR MOUSE and micro DSC techniques were used to investigate the interaction between collagen and various vegetable tannins during leather making process with the aim of gaining a deeper understanding of different water environment in relation to tannin type. We have previously showed that relaxation times may provide useful information on collagen matrix properties. The vegetable tanned leathers were obtained by patented techniques inspired from ancient recipes at the National R&D Institute for Textile and Leather, ICPI Division, Bucharest using various vegetable extracts such as myrobalan, gambier and chestnut. Longitudinal and transversal relaxation times T1 and T2eff were measured using a PM2 portable NMR-MOUSE with 20.05 MHz frequency. Micro DSC measurements were carried out with a high-sensitivity SETARAM Micro-DSC III in the temperature range (5 to 95) °C at 0.5 K min-1 heating rate. The investigated leathers showed significant differences in the values of spin-spin (T2eff) and spin-lattice (T1) relaxation times depending on tannin type that well corelates with the variation of the calorimetric parameters (denaturation temperature and enthalpy, peak shape). These results highlight the complementarity of the information obtained by the two techniques and open new ways for both designing new leather assortments and analyses of historical and archaeological leather.

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Du, Yi, Coralie Brumaud e Guillaume Habert. "Water Stabilization of Clay Bricks with Improved Tannin and Iron Mixes". In 4th International Conference on Bio-Based Building Materials. Switzerland: Trans Tech Publications Ltd, 2022. http://dx.doi.org/10.4028/www.scientific.net/cta.1.377.

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Weak water resistance is a big obstacle for clay materials to overcome in modern construction industry. Compared to the hydraulic stabilized additives, bio-additives have a lower carbon footprint and have been used in many vernacular construction techniques to immobilize clay. In this work, the traditional recipes of tannin and iron have been revisited, in particular, the question of pH and iron solubility has been explored. Oak tannin and FeCl3 were chosen and their influence on the properties of clay materials in terms of rheological properties, compressive strength, and water resistance were characterized in the lab. Based on the results, tannin can reduce the yield stress of paste while with the addition of FeCl3, the yield stress of tannin dispersed pastes increased to a value similar to the reference sample but lower than the value contain only FeCl3. The increase was attributed to the complex reaction between tannin and Fe3+. The iron-tannin complexes can also increase the samples’ strength and water resistance. Although the complexes did not change the hydrophilic properties of the samples’ surface, they prevent the ingression of water. These results are very promising as they allow the production of a fluid earth material that is water-resistant. This opens a wide range of application potentials and can help to mainstream earth materials in construction.

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Ghazali, Nurul Aimi, Shigemi Naganawa, Yoshihiro Masuda, Wan Asma Ibrahim e Noor Fitrah Abu Bakar. "Eco-Friendly Drilling Fluid Deflocculant for Drilling High Temperature Well: A Review". In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-78149.

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Conventional clay-based drilling fluids often experienced difficulties in controlling the rheological properties, gelation, and filtration due to flocculation of clay at the temperature higher than 121°C. Deflocculant or thinner, one of the drilling fluid additives, serves a significant role in preventing the association of clay particles particularly in high temperature environments such as high-pressure and high-temperature (HPHT) deep-water drilling. Lignosulfonate has been commonly used in the industry as deflocculant for clay-based drilling fluids since the late 1950s as a replacement for Quebracho tannin. Degradation at the elevated temperature limits the usage of anionic polymer and lignosulfonate. In improving the stability of deflocculant at high temperature, lignosulfonate is admixed or reacted with chromium and iron compound to obtain ferro-chrome lignosulfonate whose temperature limit is approximately 190°C. While recent ferro-chrome lignosulfonate contains less chrome than in the past, development of more environmentally friendly and higher thermally stable deflocculant is still needed. In HPHT environment which requires high-density drilling fluid, a higher thermally-stable deflocculant is also valuable for barite sagging that becomes problematic at a temperature higher than 200°C. Several findings in the past development of adhesives show that addition of tannin improves the thermal stability of lignosulfonate. Tannin is a polyphenolic compound that is natural, non-toxic and biodegradable and can be found in various part of a vascular plant other than Quebracho. Lignosulfonate, on the other hand, is a byproduct of the paper pulping process. Tannin and lignosulfonate are cross-linked to obtain tannin–lignosulfonate for use as a high-temperature drilling fluid deflocculant. Tannin and lignin are the most abundant compounds extracted from biomass. The wide availability of tannin and lignosulfonate is an advantage from a manufacturing cost viewpoint. In this paper, an overview of drilling fluids, classification of drilling fluid, high temperature reservoir environment, and mechanisms of dispersion and deflocculation are presented. Further discussion on the potential development of eco-friendly tannin–lignosulfonate based drilling fluid system for the high temperature well development also presented.

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Chen, Yibin, Kui Chen, Wei Wang e Jiaxi Chen. "Tannin from Hua Xiang Shu Infructescence". In 2012 International Conference on Biomedical Engineering and Biotechnology (iCBEB). IEEE, 2012. http://dx.doi.org/10.1109/icbeb.2012.393.

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Anwer, Muhammad A. S., Hani E. Naguib, Alain Celzard e Vanessa Fierro. "Development and Characterization of PLA-Based Bio Composites". In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-39261.

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Polymers make up an important component of the manufacturing industry. Their density and mechanical properties makes them desirable for many applications. Currently much polymer produced is from non-renewable sources which adds to waste after disposal. PLA is a bio-based polymer shown to be promising in many studies but its inherent brittleness prevents wide scale application of the polymer. One readily feasible alternative is to reinforce PLA with fillers as a means to improve mechanical properties. Two types of PLA based bio-composites were considered: PLA-Lignin & PLA-Tannin composites. PLA was the matrix in these composites with the fillers either being Lignin or Tannin. Composites containing 5, 10, and 15 wt % of the fillers were studied. The composites were fabricated by means of melt blending in a twin screw compounder followed by injection molding. SEM morphological, mechanical, and dynamic mechanical evaluations of the composites were performed. Tan delta values of both Lignin and Tannin based PLA composites increased with increasing addition of fillers with the exception of PLA with 5 wt% Tannin. Lignin appears to have a plasticizing effect on the initial tensile stiffness while tannin appears to have a stiffening effect on the initial tensile stiffness. Glass transition temperatures of all composites do not seem to change significantly from that of pure PLA.

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Griyanitasari, Gresy, Emiliana Kasmudjiastuti, Ragil Yuliatmo e Mohammad Zainal Abidin. "Evaluation of combination tanning and natural finishing on sheep leather with Uncaria Gambir Roxb extract". In The 8th International Conference on Advanced Materials and Systems. INCDTP - Leather and Footwear Research Institute (ICPI), Bucharest, Romania, 2020. http://dx.doi.org/10.24264/icams-2020.ii.11.

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The discovery of natural local resources for tanning and coloring agents are growing dramatically to sustain a cleaner leather manufacturing technology. Gambir (Uncaria gambir Roxb) has been found potential as tannin and dyestuffs for leather and textile industry. Therefore, to explore these issues, a combination tanning and finishing system were evaluated to observe the efficiency of this extract on leather processing. A combination tanning system based on chrome or glutaraldehyde – gambir and followed by gambir as coloring agent with different concentrations (100 - 200 parts/L) have been applied. In this FTIR (Fourier-transform infrared spectroscopy) analysis of gambir extract showed the presence of phenolic hydroxyl group. Our results revealed that chrome - gambir and glutaraldehyde - gambir finished leather product with 150 parts/L of gambir extract showed excellent rub fastness, color fastness to perspiration and washing. Most of the result values obtained were generally at satisfactory levels which were between 3/4 and 5 fastness values. Visual evaluation reported that chrome-gambir finished leather product with 150 parts/L of gambir extract exhibited better uniformity of colour fastness.

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Sánchez-Martín, Jesús, Víctor Encinas-Sánchez e Jesús Beltrán-Heredia. "Heavy Metals Uptake from Aqueous Effluents by Novel Adsorbent derived from Tannin Extracts Role of Tannin Source". In The 1st World Sustainability Forum. Basel, Switzerland: MDPI, 2011. http://dx.doi.org/10.3390/wsf-00627.

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Živković, Andreja, Nataša Tomić, Marija Vuksanović e Aleksandar Marinković. "Synthesis and characterization of epoxy resin coating with improved fire resistance by the addition of modified tannic acid". In 8th International Conference on Renewable Electrical Power Sources. SMEITS, 2020. http://dx.doi.org/10.24094/mkoiee.020.8.1.35.

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The paper presents a new process for obtaining eco-epoxide materials with reduced combustibility or completely non-combustible, which are synthesized from bio-renewable raw materials, whose production process consists of two stages. A particular aspect of multiple environmental significance is the use of bio-renewable resources and the reduction of the share of the toxic epoxy component in the production of epoxy materials. The first stage considers the synthesis epoxy resin components: epoxy functionalized tannic acid (TA) – ETA, and synthesis of phosphate derivatives of TA - glycidyl ester of TA modified by phosphoric acid (PGET). The second stage considers the synthesis of bio-epoxy resins using ETA and PGET that are used as a replacement of the epoxy resin component (A) – bisphenol A based epoxy in a ratio 25-100% as a reactive diluent to obtain products that can be used in the construction and other industrial fields and have reduced combustibility or completely non-combustible. The second part presents the results of thermal and mechanical tests for some of the obtained derivatives. The addition of 25% of TA derivate improved the toughness as well as the tensile strength of epoxy material. Thermogravimetry showed that samples containing tannin epoxide showed more residue left. Partial or full replacement of the epoxy component with a tannin component produces eco-friendly material with while significantly increased fire resistance (V-2 to V-0).

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Sri Kosnayani, Ai, Liah Badriah, R. Reza El Akbar e Asep Kurnia Hidayat. "A Qualitative Analysis of Tannin Type and Tannin Content in Meniran Tea (Phyllanthus Niruri Linn.) with Permanganometry Method". In Proceedings of the 5th International Conference on Health Sciences (ICHS 2018). Paris, France: Atlantis Press, 2019. http://dx.doi.org/10.2991/ichs-18.2019.4.

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Rapporti di organizzazioni sul tema "Tannin"

Provenza, Frederick, Avi Perevolotsky e Nissim Silanikove. Consumption of Tannin-Rich Forage by Ruminants: From Mechanism to Improved Performance. United States Department of Agriculture, aprile 2000. http://dx.doi.org/10.32747/2000.7695840.bard.

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Trees and shrubs are potentially important sources of food for livestock in many parts of the world, but their use is limited by tannins. Tannins reduce food intake by decreasing digestibility or by causing illness. Supplementing cattle, sheep, and goats with polyethylene glycol (PEG), which has a high affinity for binding tannins and thus attenuating their aversive effects, increases intake of high-tannin foods and improves weight gains and wool growth. The objectives of this proposal were: Objective 1: To further delineate the conditions under which PEG affects intake of high-tannin foods. Objective 2: To ascertain if animals self-regulate intake of PEG in accord with the tannin content of their diet under pen, paddock, and field conditions. Objective 3: To determine how nutritional status and PEG supplementation affect preference for foods varying in nutrients and tannins. Objective 4: To assess the effects of PEG on food selection, intake, and livestock performance in different production systems. The results from this research show that supplementing livestock with low doses of PEG increases intake of high-tannin foods and improves performance of cattle, sheep, and goats. Neutralizing the effects of tannins with supplemental PEG promotes the use of woody species usually considered useless as forage resources. Supplementing animals with PEG has the potential to improve the profitability - mainly milk production - of high-yielding dairy goats fed high-quality foods and supplemented with browse in Mediterranean areas. However, its contribution to production systems utilizing low-yielding goats is limited. Our findings also support the notion that supplemental PEG enhances the ability of livestock to control shrub encroachment and to maintain firebreaks. However, our work also suggests that the effectiveness of supplemental PEG may be low if alternative forages are equal or superior in nutritional quality and contain fewer metabolites with adverse effects.

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Landau, Sergei Yan, John W. Walker, Avi Perevolotsky, Eugene D. Ungar, Butch Taylor e Daniel Waldron. Goats for maximal efficacy of brush control. United States Department of Agriculture, marzo 2008. http://dx.doi.org/10.32747/2008.7587731.bard.

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Background. Brush encroachment constitutes a serious problem in both Texas and Israel. We addressed the issue of efficacy of livestock herbivory - in the form of goat browsing - to change the ecological balance to the detriment of the shrub vegetation. Shrub consumption by goats is kept low by plant chemical defenses such as tannins and terpenes. Scientists at TAES and ARO have developed an innovative, cost-effective methodology using fecal Near Infrared Spectrometry to elucidate the dietary percentage of targeted, browse species (terpene-richredberry and blueberry juniper in the US, and tannin-rich Pistacialentiscus in Israel) for a large number of animals. The original research objectives of this project were: 1. to clarify the relative preference of goat breeds and the individual variation of goats within breeds, when consuming targeted brush species; 2. to assess the heritability of browse intake and validate the concept of breeding goat lines that exhibit high preference for chemically defended brush, using juniper as a model; 3. to clarify the relative contributions of genetics and learning on the preference for target species; 4. to identify mechanisms that are associated with greater intake of brush from the two target species; 5. to establish when the target species are the most vulnerable to grazing. (Issue no.5 was addressed only partly.) Major conclusions, solutions, achievements: Both the Israel and US scientists put significant efforts into improving and validating the technique of Fecal NIRS for predicting the botanical composition of goat diets. Israeli scientists validated the use of observational data for calibrating fecal NIRS, while US scientists established that calibrations could be used across animals differing in breed and age but that caution should be used in making comparisons between different sexes. These findings are important because the ability to select goat breeds or individuals within a breed for maximal efficiency of brush control is dependent upon accurate measurement of the botanical composition of the diet. In Israel it was found that Damascus goats consume diets more than twice richer in P. lentiscus than Mamber or Boer goats. In the US no differences were found between Angora and Boer cross goats but significant differences were found between individuals within breeds in juniper dietary percentage. In both countries, intervention strategies were found that further increased the consumption of the chemically defended plant. In Israel feeding polyethylene glycol (PEG, MW 4,000) that forms high-affinity complexes with tannins increased P. lentiscus dietary percentage an average of 7 percentage units. In the US feeding a protein supplement, which enhances rates of P450-catalyzed oxidations and therefore the rate of oxidation of monoterpenes, increased juniper consumption 5 percentage units. However, the effects of these interventions were not as large as breed or individual animal effects. Also, in a wide array of competitive tannin-binding assays in Israel with trypsin, salivary proteins did not bind more tannic acid or quebracho tannin than non-specific bovine serum albumin, parotid saliva did not bind more tannins than mixed saliva, no response of tannin-binding was found to levels of dietary tannins, and the breed effect was of minor importance, if any. These fundings strongly suggest that salivary proteins are not the first line of defense from tannin astringency in goats. In the US relatively low values for heritability and repeatability for juniper consumption were found (13% and 30%, respectively), possibly resulting from sampling error or non-genetic transfer of foraging behavior, i.e., social learning. Both alternatives seem to be true as significant variation between sequential observations were noted on the same animal and cross fostering studies conducted in Israel demonstrated that kids raised by Mamber goats showed lower propensity to consume P. lentiscus than counterparts raised by Damascus goats.

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Tian, Li, Rachel Amir, Doron Holland e Hamutal Borochov-Neori. Elucidating the genetic pathways involved in shikimate, anthocyanin and hydrolyzable tannin accumulation in pomegranate. United States Department of Agriculture, gennaio 2015. http://dx.doi.org/10.32747/2015.7600023.bard.

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Carpenter, Christopher, Brandyn Churchill e Michelle Marcus. Bad Lighting: Effects of Youth Indoor Tanning Prohibitions. Cambridge, MA: National Bureau of Economic Research, ottobre 2021. http://dx.doi.org/10.3386/w29443.

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Yoo, Jeong-Ju, e Seahee Lee. Identifying Factors Influence Individuals' Intention to Quit Tanning: Sociocultural Perspective. Ames: Iowa State University, Digital Repository, 2017. http://dx.doi.org/10.31274/itaa_proceedings-180814-1823.

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Cordingley, John S. The Molecular and Cellular Mechanisms of Quinone Tanning of Proteins. Fort Belvoir, VA: Defense Technical Information Center, giugno 1994. http://dx.doi.org/10.21236/ada303501.

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Keenan, Teresa A. Suncare, Tanning, and Skin Cancer: A Survey of Adults Ages 18 and Older. Washington, DC: AARP Research, febbraio 2024. http://dx.doi.org/10.26419/res.00779.003.

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Yoo, Jeong-Ju, e Hye-Young Kim. Influences of Parental Attachment and Life Satisfaction on Social Tanning Behaviors among College Students. Ames: Iowa State University, Digital Repository, 2013. http://dx.doi.org/10.31274/itaa_proceedings-180814-820.

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Gilbert, G., E. Guyer e D. Brownell. Plastic film heat exchanger development project field test at Prime Tanning Company, Phase 3. Office of Scientific and Technical Information (OSTI), agosto 1989. http://dx.doi.org/10.2172/5255589.

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Harding, Scott, A, Chung-jui Tsai e Lindroth, Richard, L. A genomics investigation of partitioning into and among flavonoid-derived condensed tannins for carbon sequestration in Populus. Office of Scientific and Technical Information (OSTI), marzo 2013. http://dx.doi.org/10.2172/1069258.

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