271 research outputs found

    Understanding the buckling behaviour of steered tows in automated dry fibre placement (ADFP)

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    Technologies for automated fibre lay-up have proven their usefulness in composites manufacturing. Further development of the technologies, such as Automated Dry Fibre Placement (ADFP), allow further reduction of waste and increase of the design space through tow steering which enables creation of composites with tailored properties. Tow steering is, however, limited by possible defects such as wrinkles which result from mismatch of fibre length and steering path. This paper addresses wrinkle formation at different steering radii and provides a closed-form solution for the problem. Experimental results are used for estimation of the model parameters and validation of the model. An analytical framework is used to explore effects of processing parameters on defect formation. It was found that the tack stiffness has the greatest influence on defect formation. Parametric studies showed that increase of the temperature within the admissible temperature window can improve the tack properties and hence improve the lay-up

    Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV

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    Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7  fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale

    Anticholinesterase and Antioxidant Activities of Spilanthes filicaulis Whole Plant Extracts for the Management of Alzheimer’s Disease

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    Background: Spilanthes filicaulis is a tropical herb implicated as a memory enhancer in ethnomedicine. Objective: The study investigated acetyl/butyryl cholinesterase inhibitory and antioxidant activities of different extracts of S. filicaulis whole plant and correlated them to its phytochemical constituents. Methods: The powdered whole plant was successively extracted with n-hexane, ethyl acetate and methanol. Acetyl cholinesterase (AChE) and Butyryl cholinesterase (BuChE) inhibitory activity were evaluated by Ellman colorimetry assay. Antioxidant activity was tested using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, ferric reducing power and nitric oxide scavenging assays. Total phenolic, flavonoid and tannin were estimated using standard methods. Correlation was determined using Quest Graphℱ Regression Calculator. Results: Various extracts exhibited concentration-dependent AChE and BuChE inhibitory activity with ethyl acetate extract being the highest with IC50 of 0.77 ÎŒg/mL and 0.92 ÎŒg/mL for AChE and BuChE respectively. The ethyl acetate extract also showed the highest reducing power when compared with the other extracts. The methanol extract had slightly higher phenolic and flavonoid content and showed the highest DPPH radical scavenging effect. DPPH scavenging, AChE and BuChE inhibition had high correlation with the total flavonoid content with R2 values of 1.00, 0.800 and 0.992 respectively while nitric oxide scavenging had high correlation with phenolics and tannins with R2 = 0.942 and 0.806 respectively. Conclusion: These results show that the extracts of the whole plant of S. filicaulis possess significant AChE/BuChE inhibitory and antioxidant properties, mostly due to its flavonoid content, suggesting the possible use of the plant in neurodegenerative diseases such as AD
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