Search results for "FIBER"
showing 10 items of 2343 documents
BN/GdxTi(1-x)O(4-x)/2 nanofibers for enhanced photocatalytic hydrogen production under visible light
2019
Abstract BN/GdxTi(1-x)O(4-x)/2 nanofibers were elaborated via electrospinning technique. The properties of the prepared nanofibers were controlled using different ratios of gadolinium. All the prepared nanofibers exhibit the tetragonal structure of anatase TiO2 phase. An increase in the unit cell volume and a decrease in the crystallite size were observed with increasing the doping amount of Gd3+ as revealed by Rietveld refinement analysis. The defect in TiO2 lattice was observed by Raman. The Gd3+ incorporation inside TiO2 lattice, which is accompanied by the creation of Ti-O-Gd bond, was characterized by the X-ray photoelectron spectra. Scanning electron microscopy demonstrates that the a…
Core-shell Zn-doped TiO2-ZnO nanofibers fabricated via a combination of electrospinning and metal-organic chemical vapour deposition
2010
Zn-doped TiO2 nanofibers shelled with ZnO hierarchical nanoarchitectures have been fabricated combining electrospinning of TiO2 (anatase) nanofibers and metal-organic chemical vapor deposition (MOCVD) of ZnO. The proposed hybrid approach has proven suitable for tailoring both the morphology of the ZnO external shell as well as the crystal structure of the Zn-doped TiO2 core. It has been found that the Zn dopant is incorporated in calcined electrospun nanofibers without any evidence of ZnO aggregates. Effects of different Zn doping levels of Zn-doped TiO2 fibers have been scrutinized and morphological, structural, physico-chemical and optical properties evaluated before and after the hierarc…
Photoluminescence: A very sensitive tool to detect the presence of anatase in rutile phase electrospun TiO 2 nanofibers
2015
Abstract This paper reports on the synthesis and the characterization of titanium dioxide (TiO2) nanofibers prepared by electrospinning. The samples were annealed at various temperatures in air for 4 h. The as-spun and annealed TiO2/PVP composite nanofibers were characterized by scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy analysis (EDX), X-ray diffraction (XRD), Raman spectroscopy and photoluminescence (PL). The results show that the heat treatment has an effect on the crystallization process. Even if the XRD data shows a complete anatase-to-rutile transition in the TiO2 nanofibers at 900 °C, photoluminescence reveals a small portion of anatase in rutile sample.…
The soluble dietary fiber inulin can influence the bioaccessibility of enniatins.
2012
Enniatins (ENs) are bioactive compounds produced by the secondary metabolism of several Fusarium strains and are known to have various biological activities, such as acting as enzyme inhibitors, antifungal antibacterial agents, and immunomodulatory substances. This study investigated the bioaccessibility of the ENs in wheat crispy breads produced with three different inulin concentrations (1, 5 and 10%). The mean bioaccessibility data of the four ENs (A, A(1), B and B(1)) ranged from 68.67% to 84.67 in the experiments carried out without inulin, whereas the data ranged from 51.00 to 74.00% in the experiments carried out with the wheat crispy bread produced with 5 and 10% of the inulin.
Natural Compounds as Sustainable Additives for Biopolymers
2020
In the last few decades, the interest towards natural compounds, coming from a natural source and biodegradable, for biopolymers is always increasing because of a public request for the formulation of safe, eco-friendly, and sustainable materials. The main classes of natural compounds for biopolymers are: (i) naturally occurring fillers (nFil), such as nano-/micro- sized layered alumino-silicate: halloysite, bentonite, montmorillonite, hydroxyapatite, calcium carbonate, etc.; (ii) naturally occurring fibers (nFib), such as wood and vegetable fibers; (iii) naturally occurring antioxidant molecules (nAO), such as phenols, polyphenols, vitamins, and carotenoids. However, in this short review, …
Association of Fiber Orientation and Dissection Properties of Ascending Thoracic Aortic Aneurysms With Aortic Valve Morphology
2011
Type A aortic dissection (AoD) of an ascending thoracic aortic aneurysm (ATAA) is a life-threatening cardiovascular emergency with a high potential for death. Despite improved surgical techniques, the morbidity risk for emergent surgery remains 24% worldwide according to data from the International Registry of Acute Aortic Dissection [1].Copyright © 2011 by ASME
The possibilities of using low-cost fibrous natural materials as sorbents for removing aliphatic hydrocarbons (C6-C15) from an aqueous solution
2020
Sorption of oil-related products (including mainly the propellants) is the basic process that coun-teracts spreading these types of pollution into the environment. Plenty of synthetic substances (including multi-component petroleum products) must be removed both from the fresh and ground-water. The aim of this study was to compare the possibilities of using natural fibrous materials (also weed or waste materials): broadleaf cattail (Typha latifolia L.) seeds, peat and coconut fiber as sorbents of aliphatic hydrocarbons from an aqueous solution. In order to increase sorptive capacity, tested materials were mercerized in hot (80°C) NaOH for sorption properties improvement. The removal of alip…
ON THE EFFECTS OF A CRACK PROPAGATING TOWARD THE INTERFACE OF A BIMATERIAL SYSTEM
2006
This paper deals with the influence of matrix cracks on the failure mode of bimaterial systems and composite materials. In order to investigate such an influence, the stress field near a crack embedded into the more yielding material and propagating perpendicularly to the interface, has been analyzed by using systematic numerical simulations. Such analysis has shown that the crack propagation give rises to transversal stresses that can damage the reinforcing materials when this has low modulus, as glass fibers, or low transversal strength, such as carbon fibers. Moreover, the longitudinal stress concentration can damage the reinforcing material only if this has high stiffness, as in the cas…
Confident methods for the evaluation of the hydrogen content in nanoporous carbon microfibers
2012
Abstract Nanoporous carbon microfibers were grown by chemical vapor deposition in the vapor-liquid solid mode using different fluid hydrocarbons as precursors in different proportions. The as-grown samples were further treated in argon and hydrogen atmospheres at different pressure conditions and annealed at several temperatures in order to deduce the best conditions for the incorporation and re-incorporation of hydrogen into the microfibers through the nanopores. Since there are some discrepancies in the results on the hydrogen content obtained under vacuum conditions, in this work, we have measured the hydrogen content in the microfibers using several analytical methods in ambient conditi…
Muons in air showers at the Pierre Auger Observatory: Measurement of atmospheric production depth
2014
The surface detector array of the Pierre Auger Observatory provides information about the longitudinal development of the muonic component of extensive air showers. Using the timing information from the flash analog-to-digital converter traces of surface detectors far from the shower core, it is possible to reconstruct a muon production depth distribution. We characterize the goodness of this reconstruction for zenith angles around 60° and different energies of the primary particle. From these distributions, we define Xμmax as the depth along the shower axis where the production of muons reaches maximum. We explore the potentiality of Xμmax as a useful observable to infer the mass compositi…