نتایج جستجو برای: bast fibers

تعداد نتایج: 70811  

Journal: :Journal of agricultural and food chemistry 2004
Ana Gutiérrez Isabel M Rodríguez José C Del Río

The chemical composition of lignin and lipids of bast fibers from kenaf (Hibiscus cannabinus) used for high-quality paper pulp production was studied. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) of fibers showed a lignin with a high syringyl/guaiacyl ratio (5.4) and minor amounts of p-hydroxyphenyl units. Simultaneously, sinapyl and coniferyl acetates were also identified, indicat...

Journal: :Journal of Archaeological Science: Reports 2023

Textiles from Neolithic Çatalhöyük are among the earliest and best-preserved woven plant artifacts ancient Southwest Asia. Recent examinations of textiles Çatalhöyük’s East Mound middle habitation phase (6700–6500 cal. B. C.) provide surprising evidence that instead being made flax (linen, Linum usitatissimum), as previously thought, fibers inner bark trees (tree bast), some samples identified ...

Journal: :Journal of agricultural and food chemistry 2006
Ana Gutiérrez Isabel M Rodríguez José C del Río

The chemical composition of lignin and lipids of bast fibers from industrial hemp (Cannabis sativa) used for high-quality paper pulp production was studied. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) of fibers showed a lignin with a p-hydroxyphenyl:guaiacyl:syringyl unit (H:G:S) molar proportion of 13:53:34 (S/G ratio of 0.64). p-Hydroxycinnamic acids, namely, p-coumaric and feru...

2016
Marc Behr Sylvain Legay Eva Žižková Václav Motyka Petre I. Dobrev Jean-Francois Hausman Stanley Lutts Gea Guerriero

Cannabis sativa L. is an annual herbaceous crop grown for the production of long extraxylary fibers, the bast fibers, rich in cellulose and used both in the textile and biocomposite sectors. Despite being herbaceous, hemp undergoes secondary growth and this is well exemplified by the hypocotyl. The hypocotyl was already shown to be a suitable model to study secondary growth in other herbaceous ...

Journal: :جنگل و فرآورده های چوب 0
امیر سعادتی دانشجوی کارشناسی ارشد بیولوژی و آناتومی، گروه علوم و صنایع چوب و کاغذ، دانشکدۀ منابع طبیعی، دانشگاه تهران، کرج، ایران کامبیز پورطهماسی دانشیار گروه علوم و صنایع چوب و کاغذ، دانشکدۀ منابع طبیعی، دانشگاه تهران، کرج، ایران سید علیرضا سلامی استادیار گروه علوم باغبانی و مهندسی فضای سبز، دانشکدۀ علوم و مهندسی کشاورزی، دانشگاه تهران، کرج، ایران رضا اولادی استادیار گروه علوم و صنایع چوب و کاغذ، دانشکدۀ منابع طبیعی، دانشگاه تهران، کرج، ایران

natural, renewable, biodegradable and low pollution hemp fibers are an alternative to trees xylem and artificial fibers. in this study, xylem and bast fiber properties of six iranian hemp populations including length, width, wall thickness, lumen width and wall index were measured and compared. to this purpose, collected population seeds from different parts of iran were nursed in a controlled ...

Journal: :جنگل و فرآورده های چوب 0
پژمان رضایتی چرانی استادیار گروه صنایع خمیر و کاغذ، دانشکدة جنگل داری و محیط زیست، دانشگاه صنعتی خاتم الانبیاء بهبهان، بهبهان، ایران محمد رضا دهقانی فیروزآبادی دانشیار گروه صنایع خمیر و کاغذ، دانشکدة صنایع چوب و کاغذ، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران

nanofibrillated cellulose fibers were produced from unbleached kraft pulp of kenaf bast fiber. air dried and vacuum filtrated films of cellulose nanofibers were produced and their density and tensile properties were investigated. kenaf bast fiber unbleached kraft pulp has good potential for production of cellulose nanofibers by microfluidizer; so that the use of kenaf bast fiber unbleached kraf...

Journal: :Bioresource technology 2005
Ana Gutiérrez José C del Río

The composition of pitch deposits occurring in pulp sheets and mill circuits during soda/anthraquinone pulping and elemental chlorine-free pulp bleaching of bast fibers of industrial hemp (Cannabis sativa) was studied. Pitch deposits were extracted with acetone, and the extracts analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Acetone extracts (15-25% of pit...

پایان نامه :وزارت بهداشت، درمان و آموزش پزشکی - دانشگاه علوم پزشکی و خدمات بهداشتی درمانی ایران 1388

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