Krishnan K A.,Cochin University of Science and Technology |
Jose C.,Newman College |
Rohith K.R.,Cochin University of Science and Technology |
George K.E.,Albertian Institute of Science and Technology
Industrial Crops and Products | Year: 2015
In this work, cellulose nano fibers were extracted from sisal leaves using steam explosion technique. The chemical composition, morphology and thermal properties of the nano fibers and their intermediate products were characterized. The progressive removal of noncellulosic constituents is confirmed by FTIR studies. X-ray diffraction reveals that crystallinity increased with successive chemical treatments. Characterization of the fibers by SEM and TEM gives evidence for the formation of cellulose nano fibers. TGA results show that the cellulose nano fibers exhibit enhanced thermal properties over the untreated fibers. The effect of cellulose nanofibers on the mechanical and morphological properties of polypropylene/polystyrene blend has been studied. Water transmission data shows that the addition of 0.5. wt% CNF decreased the transmission rate in the composite. Mechanical properties improve with the incorporation of cellulose nano fiber. © 2015 Elsevier B.V.
Jose K.K.,Thomas College |
Luke J.A.,Newman College
Quality and Reliability Engineering International | Year: 2013
Process capability indices such as Cp, Cpk, C pmk and Cpm are widely used in manufacturing industries to provide a quantitative measurement of the performance of the products. In this article, we derived generalized confidence intervals for the difference between process capability indices for two processes under one-way random effect model. Our study provides coverage probability close to the nominal value in almost all cases as shown via simulation. An example from industrial contexts is given to illustrate the results. Copyright © 2012 John Wiley & Sons, Ltd.
Werner N.,Kavli Institute for Particle Astrophysics and Cosmology |
Werner N.,SLAC |
Sun M.,University of Virginia |
Bagchi J.,Inter-University Center for Astronomy and Astrophysics |
And 9 more authors.
Monthly Notices of the Royal Astronomical Society | Year: 2011
We present a multiwavelength study of the energetic interaction between the central active galactic nucleus (AGN), the intracluster medium (ICM) and the optical emission-line nebula in the galaxy cluster Sérsic 159-03. We use X-ray data from Chandra, high-resolution X-ray spectra and ultraviolet (UV) images from XMM-Newton, Hα images from the Southern Astrophysics Research Telescope, Hubble Space Telescope optical imaging, and Very Large Array and Giant Metrewave Radio Telescope radio data. The cluster centre displays signs of powerful AGN feedback, which has cleared the central regions (r < 7.5kpc) of a dense, X-ray-emitting ICM. X-ray spectral maps reveal a high-pressure ring surrounding the central AGN at a radius of r~ 15kpc, indicating an AGN-driven weak shock. The cluster harbours a bright, 44kpc long Hα+[Nii] filament extending from the centre of the cD galaxy to the north. Along the filament, we see low-entropy, high-metallicity, cooling X-ray gas. The gas in the filament has most likely been uplifted by 'radio mode' AGN activity and subsequently stripped from the galaxy due to its relative southward motion. Because this X-ray gas has been removed from the direct influence of the AGN jets, part of it cools and forms stars as indicated by the observed dust lanes, molecular and ionized emission-line nebulae and the excess UV emission. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.
Bagchi J.,Inter-University Center for Astronomy and Astrophysics |
Vivek M.,Inter-University Center for Astronomy and Astrophysics |
Vikram V.,University of Pennsylvania |
Hota A.,Center for Excellence in Basic science |
And 6 more authors.
Astrophysical Journal | Year: 2014
The radio galaxy phenomenon is directly connected to mass-accreting, spinning supermassive black holes found in the active galactic nuclei. It is still unclear how the collimated jets of relativistic plasma on hundreds to thousands of kiloparsec scales form and why they are nearly always launched from the nuclei of bulge-dominated elliptical galaxies and not flat spirals. Here we present the discovery of the giant radio source J2345-0449 (z = 0.0755), a clear and extremely rare counterexample where relativistic jets are ejected from a luminous and massive spiral galaxy on a scale of ∼1.6 Mpc, the largest known so far. Extreme physical properties observed for this bulgeless spiral host, such as its high optical and infrared luminosity, large dynamical mass, rapid disk rotation, and episodic jet activity, are possibly the results of its unusual formation history, which has also assembled, via gas accretion from a disk, its central black hole of mass >2 × 108 M ⊙. The very high mid-IR luminosity of the galaxy suggests that it is actively forming stars and still building a massive disk. We argue that the launch of these powerful jets is facilitated by an advection-dominated, magnetized accretion flow at a low Eddington rate onto this unusually massive (for a bulgeless disk galaxy) and possibly fast spinning central black hole. Therefore, J2345-0449 is an extremely rare, unusual galactic system whose properties challenge the standard paradigms for black hole growth and the formation of relativistic jets in disk galaxies. Thus, it provides fundamental insight into accretion disk-relativistic jet coupling processes. © 2014. The American Astronomical Society. All rights reserved.
Chirayil C.J.,Newman College |
Mathew L.,Newman College |
Thomas S.,Mahatma Gandhi University
Reviews on Advanced Materials Science | Year: 2014
Lignocellulosic fibers have become the focus of intense interest in recent years. They have attracted the attention of scientists and technologies worldwide because of their tremendous advantages and now it is possible to isolate cellulose nanofibrils and nanowhiskers from various lignocellulosic wastes. Studies in this area have shown that both cellulose nanofibrils and nanowhiskers could be used as reinforcing fillers to improve mechanical and barrier properties of different types of polymer systems which include rubbers, thermoplastics and thermo-sets. This review paper provides an overview of recent progress made in the area of nanocellulose and nanowhiskers preparation from various natural fibers. A thorough review of the various techniques being currently used for the isolation of cellulose nanofibers and nanowhiskers has been presented. Finally, the emerging applications of these materials in various fields including nanocomposite preparation have been presented. © 2014 Advanced Study Center Co. Ltd.