1,494 research outputs found
Bending behavior of shape memory polymer based laminates
ArticleCOMPOSITE STRUCTURES. 78(2): 153-161 (2007)journal articl
Mechanical properties of composites filled with SMA particles and short fibers
ArticleCOMPOSITE STRUCTURES. 79(1): 90-96 (2007)journal articl
Stiffness and vibration characteristics of SMA/ER3 composites with shape memory alloy short fibers
ArticleCOMPOSITE STRUCTURESjournal articl
High energy processes in clusters of galaxies and the origin of cosmic rays
We test the hypothesis of a universal cosmic ray intensity by calculating the secondary electron or positron production in the hadronic interactions of cosmic ray nuclei with intergalactic gas within clusters of galaxies. We find that the spectral characteristics of the radio synchrotron emission by these secondary electrons is not consistent with observations of the Coma cluster. Thus the hypothesis can be ruled out on cluster scales.published_or_final_versio
Shape memory effect and mechanical properties of carbon nanotube/shape memory polymer nanocomposites
ArticleCOMPOSITE STRUCTURES. 81(2): 176-184 (2007)journal articl
Heterogeneous activation of peroxymonosulfate by a biochar-supported Co3O4 composite for efficient degradation of chloramphenicols
Herein, a new peroxymonosulfate (PMS) activation system was established using a biochar (BC)-supported Co3O4 composite (Co3O4-BC) as a catalyst to enhance chloramphenicols degradation. The effects of the amount of Co3O4 load on the BC, Co3O4-BC amount, PMS dose and solution pH on the degradation of chloramphenicol (CAP) were investigated. The results showed that the BC support could well disperse Co3O4 particles. The degradation of CAP (30 mg/L) was enhanced in the Co3O4-BC/PMS system with the apparent degradation rate constant increased to 5.1, 19.4 and 7.2 times of that in the Co3O4/PMS, BC/PMS and PMS-alone control systems, respectively. Nearly complete removal of CAP was achieved in the Co3O4-BC/PMS system under the optimum conditions of 10 wt% Co3O4 loading on BC, 0.2 g/L. Co3O4-BC, 10 mM PMS and pH 7 within 10 min. The Co3O4/BC composites had a synergistic effect on the catalytic activity possibly because the conducting BC promoted electron transfer between the Co species and HSO5- and thus accelerated the Co3+/Co(2+)redox cycle. Additionally, over 85.0 +/- 1.5% of CAP was still removed in the 10th run. Although both SO4 center dot- and OH center dot were identified as the main active species, SO4 center dot- played a dominant role in CAP degradation. In addition, two other chloramphenicols, i.e., florfenicol (FF) and thiamphenicol (TAP), were also effectively degraded with percentages of 86.4 +/- 13% and 71.8 +/- 1.0%, respectively. This study provides a promising catalyst Co3O4-BC to activate PMS for efficient and persistent antibiotics degradation. (C) 2019 Elsevier Ltd. All rights reserved
Preparation and characterization of collagen-chitosan composites
In this article, nature derived collagen was mixed with chitosan and crosslinked by formaldehyde to form a homogeneous composite membrane. The microstructure of the composite was characterized by transmission electron microscopy and differential scanning calorimetry. Mechanical and swelling properties of the composite were improved compared with pure collagen and can be modulated via changing the crosslinking conditions, such as pH, time, and concentration. (C) 1997 John Wiley & Sons, Inc
Porous hydroxyapatite reinforced with collagen protein
Porous hydroxyngatite (HAP) with certain porosity and pore size was prepared, and incorporated with bovine collagen protein. The composition and structure of the HAP was confirmed by X-Rag Diffraction (XHD) and ICP. Scanning Electron Microscopy (SEM), mechanical tests and in vitro degradation were performed. Collagen protein vith low antigenicity was obtained from bovine tendon by enzyme digestion, and was then forced to fill in the HAP matrix to form composites. Scanning Electron Microscopy (SEM), Mechanical tests and in vitro degradation were performed. The test results show that first, HAP thus made has specific pore size and directions; second, mechanical properties of the composites have been markedly improved; third, the in vitro degradation rate of the composite is almost the same as and mainly controlled by the degradation rate of collagen
Generalized Painleve-Gullstrand descriptions of Kerr-Newman black holes
Generalized Painleve-Gullstrand metrics are explicitly constructed for the
Kerr-Newman family of charged rotating black holes. These descriptions are free
of all coordinate singularities; moreover, unlike the Doran and other proposed
metrics, an extra tunable function is introduced to ensure all variables in the
metrics remain real for all values of the mass M, charge Q, angular momentum
aM, and cosmological constant \Lambda > - 3/(a^2). To describe fermions in
Kerr-Newman spacetimes, the stronger requirement of non-singular vierbein
one-forms at the horizon(s) is imposed and coordinate singularities are
eliminated by local Lorentz boosts. Other known vierbein fields of Kerr-Newman
black holes are analysed and discussed; and it is revealed that some of these
descriptions are actually not related by physical Lorentz transformations to
the original Kerr-Newman expression in Boyer-Lindquist coordinates - which is
the reason complex components appear (for certain ranges of the radial
coordinate) in these metrics. As an application of our constructions the
correct effective Hawking temperature for Kerr black holes is derived with the
method of Parikh and Wilczek.Comment: 5 pages; extended to include application to derivation of Hawking
radiation for Kerr black holes with Parikh-Wilczek metho
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