1,721,013 research outputs found
Composite biomaterials from fibre wastes: Characterization of wool-cellulose acetate blends
No full textHistological components from wool fibre wastes were extracted by an enzyme-ultrasonic treatment, characterised by SDS-PAGE and successively included, in different proportions, in a cellulose acetate matrix to make composite film-forming blends, suitable for film casting and filament spinning. Chemical, thermal and mechanical properties were characterised by FT-IR spectroscopy, DSC, TGA and tensile tests; surface and internal morphology were investigated by SEM and light microscopy. Cortical cells were partially degraded during extraction from wool, but the degradation extent does not depend on the enzyme amount used which, instead, showed an influence on the yield of the cell production. Cellulose acetate-wool cell blends are capable of forming smooth translucent composite films with acceptable tensile, thermal and water absorption properties. Extrusion in the form of filament resulted in a general orientation of the cortical cells in the direction of the fibre axis.
Application for keratin-cellulose based bio-composite materials can be envisaged as compostable packaging, disposables, agricultural films, textile fibres with novel properties such as improved fire resistance, moisture regain, dyeing performances, and colour effects, handle and look
Antimicrobial chitosan finish of cotton and silk fabrics by UV-curing with 2-hydroxy-2-methylphenylpropane-1-one
No full textRecupero e valorizzazione degli scarti di lana: caratterizzazione di membrane di acetato di cellulosa e cellule corticali
No full textChitosan coated cotton gauze for antibacterial water filtration
No full textCommunicable diseases can be transmitted by contaminated water. Water decontamination process is fundamental to eliminate microorganisms. In this work, cotton gauzes were coated with chitosan using an UV-curing process or cationized by introduction of quaternary ammonium groups and tested, in static and dynamic conditions, as water filter for biological disinfection against both Gram-negative and Gram-positive bacteria. Both materials showed good antibacterial activity, in static assessment, instead in dynamic conditions, chitosan treated gauze showed a high antimicrobial efficiency in few seconds of contact time. This composite could be a good candidate for application as biological filter
Multifunctional finishing of wool fabrics by chitosan UV-grafting: An approach
No full textThe aim of this study was the surface modification of wool fibers to confer a multifunctional finishing
to the fabrics, improving the textile value and its applications without damage of comfort properties.
The attention was focused on an economical and environmental friendly process to obtain an effective
treatment with good durability to washing.
Chitosan in acetic acid solution was applied by padding, and grafted by ultraviolet radiation, through
radical reactions promoted by a photoinitiator. 2% chitosan grafted was enough to confer satisfactory
antimicrobial activity (67% reduction of Escherichia coli) after an oxidative wool pre-treatment and 1 h
impregnation at 50 ◦C. Moreover treated wool fabrics showed a strong dyeability increase toward acid dye.
However the evaluation of the treatment durability to laundering showed different behavior depending
on the nature of the surfactants. Finally, anti-felting properties with respect to untreated fabrics were
revealed, while no effect was shown toward anti-pilling properties
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Multifunctional Finishing of Wool Fabrics by Chitosan UV-grafting
No full textChitosan was grafted on wool knitted fabrics, by ultraviolet radiation, in order to confer peculiar properties increasing the textile value and its applications. Results showed first of all the antimicrobial properties conferred by the treatment. Chitosan weight on was optimized while an oxidative pre-treatment of the wool as well as the impregnation method were investigated to improve the effectiveness of treated
fabrics. Moreover treated wool fabrics showed an increased dyeability towards acid dyes and antifelting properties with respect to untreated fabrics, while no effect was revealed toward antipilling properties
Antibacterial Water Filtration by Cationized or Chitosan Coated Cotton Gauze
No full textCommunicable diseases can be transmitted by contaminated water and water decontamination process is fundamental to eliminate micro-organisms. In this work, cotton gauzes were coated with chitosan, using an UV-curing process, or cationized by introduction of quaternary ammonium groups and tested, in static and dynamic conditions, as water filter for biological disinfection against both Gram-negative and Gram-positive bacteria. With both treatments 100% microorganisms reduction was reached in static assessment, while in dynamic conditions better results were obtained by chitosan treated gauze, reaching 100% S.Aureus and K. Pneumoniae reduction with 4 s and 8 s contact time respectively. This substrate could be a good candidate for application as biological filter
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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