Chatterjee S.,Sn Bose National Center For Basic Science |
Harish R.,TCE Consulting Engineers Ltd |
Schutz G.M.,Jülich Research Center
Chemie-Ingenieur-Technik | Year: 2013
In the past, the investigation of catalytic reactivity enhancement through molecular traffic control (MTC) by means of dynamical Monte Carlo simulations of catalysis was initiated in simple, idealized zeolite channel networks. These results are reviewed here and, emphasizing more recent work, the conditions of reactivity enhancement through MTC are examined for a realistic channel topology based on the pore structure of the zeolite TNU-9. For a wide range of reaction rates a very strong MTC effect can be found that increases with grain size. This effect is argued to be a generic feature of a certain class of zeolite pore topologies. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Elayiaraja P.,TCE Consulting Engineers Ltd |
Harish S.,TU Eindhoven |
Wilson L.,Ingersoll Rand Energy Systems |
Bensely A.,Aristotle University of Thessaloniki |
Lal D.M.,Anna University
Experimental Heat Transfer | Year: 2010
The effect of the cooling performance of a copper metal foam heat sink under buoyancy-induced convection is investigated in this work. Experiments are conducted on copper metal foam of 61.3% porosity with 20 pores per inch. The pressure drop experiment is carried out to find the permeability and foam coefficient of the porous media. It is found that the property of porous media changes by changing the angle of inclination of the porous media from a horizontal to a vertical position while keeping the orientation and porosity the same. The Hazen-Dupuit Darcy model is used to curve-fit the longitudinal global pressure drop versus the average fluid speed data from an isothermal steady-flow experiment across the test section of the porous medium. The study concludes that the permeability and foam coefficient for copper foam is found to be 1.11 10-7 m2 and 79.9 m-1, respectively. The heat transfer study shows that the thermal performance of copper metal foam is 35-40% higher than the conventional aluminum metal heat sink under an actual conventional mode. Copyright © Taylor & Francis Group, LLC.
Matin A.,University of Calcutta |
Banerjee S.,University of Calcutta |
Gupta C.D.,University of Calcutta |
Gupta C.D.,TCE Consulting Engineers Ltd. |
Banerjee N.,University of Calcutta
International Geology Review | Year: 2012
Structural investigations in the Precambrian Singhbhum Shear Zone of eastern India document an intimate relationship between micro- to meso-scale structures and the deformation history. Shear zone rocks are characterized by composite foliation, a well-developed stretching lineation, folds, shear planes, and quartz veins. These structures reflect thrusting of the Proterozoic north Singhbhum hanging wall block over the Archaean south Singhbhum footwall block. Microstructural analysis of multiple foliation and mylonitic rocks within the shear zone helps to define its progressive evolution. During progressive deformation, overprinting of microstructures resulted in incomplete transposition or complete erasing of previously formed structures and mineral assemblages, allowing room for new dynamic equilibrium structures to form. The dominant deformation mechanism was dissolution-recrystallization, with locally important fluid circulation responsible for transformation of the quartzo-feldspathic mass into phyllonite, and quartzites and schists into mylonite. Textural features suggest that the bulk deformation was non-coaxial, evolving from dominant pure shear in the early stage followed by simple shear in a single progressive strain history of the Singhbhum Shear Zone. © 2012 Copyright Taylor and Francis Group, LLC.
Chatterjee S.,Technion - Israel Institute of Technology |
Harish R.,TCE Consulting Engineers Ltd |
Schutz G.M.,Institute of Complex Systems
Journal of Physical Chemistry B | Year: 2011
Reactivity enhancement in a catalytic zeolite grain through molecular traffic control (MTC) rests on the basic notion that the reactant and product molecules prefer to diffuse along different channels inside the grain and therefore do not mutually hinder their transport in and out of the grain. We investigate the conditions of reactivity enhancement in the presence of MTC for a realistic channel topology that describes the pore structure of a TNU-9 zeolite. We compare the output current of an MTC system with a reference system, which does not show any channel selectivity. For a wide range of reaction rates and for different grain sizes, we find that there is a very significant enhancement of reactivity for the MTC system. This effect remains strong as the grain size increases. The mechanism behind reactivity enhancement is argued to be generic rather than being confined to the particular structure of TNU-9. © 2011 American Chemical Society.
Ramu Ch.,TCE Consulting Engineers Ltd |
Mehta N.K.,Indian Institute of Technology Roorkee |
Kumar P.,Indian Institute of Technology Roorkee |
Shankara Murthy A.G.,Indian Institute of Technology Roorkee
International Journal of Manufacturing Technology and Management | Year: 2010
This paper aims at optimising step drill geometry, to minimise burr size, in drilling mild steels. The influence of step parameters namely step angle, size and length on burr size were studied. The results reveal that burr size depends not only on thrust force but also on torque. Optimisation results show that to get minimum burr height on the exit side, step diameter should be approximately 75-85% of drill diameter and step length should be about 50% of drill diameter. Empirical equations for thrust force, torque and burr height were also established in terms of step parameters. Copyright © 2010 Inderscience Enterprises Ltd.
Ahluwalia P.K.,TCE Consulting Engineers Ltd |
Nema A.K.,Indian Institute of Technology Delhi
Practice Periodical of Hazardous, Toxic, and Radioactive Waste Management | Year: 2010
Computer waste has considerable reverse flow in terms of reuse and recycles. The reuse component is particularly significant for developing nations like India. The hierarchy of prevention, reuse, recycle/treatment, and disposal in a landfill is a universally accepted approach to waste management. This approach becomes complex to practice if due considerations are given to cost, health, environment issues, and socially perceived risk in decision making. Shifting from one stage of hierarchy to another becomes an involved decision requiring an integrated approach to visualize the tradeoffs between these factors. Also, to be able to reach the best possible configuration of such waste management systems, it is necessary to consider its reappearance in future years. The present study proposes a methodology for estimating the optimum reuse span for a waste and demonstrates the same by applying the same to a personal computer. The results of the example problem clearly demonstrate the variation in optimum reuse span for different objectives/priorities. The results can help the decision makers limit the reuse of waste categories beyond a certain age. © 2010 ASCE.
Saha D.,Indian Statistical Institute |
Chakraborti S.,Indian Statistical Institute |
Chakraborti S.,TCE Consulting Engineers Ltd. |
Tripathy V.,Indian Statistical Institute
Journal of the Geological Society of India | Year: 2010
Recent works suggest Proterozoic plate convergence along the southeastern margin of India which led to amalgamation of the high grade Eastern Ghats belt (EGB) and adjoining fold-and-thrust belts to the East Dhrawar craton. Two major thrusts namely the Vellikonda thrust at the western, margin of the Nellore Schist belt (NSB) and the Maidukuru thrust at the western margin of the Nallamalai fold belt (NFB) accommodate significant upper crustal shortening, which is indicated by juxtaposition of geological terranes with distinct tectonostratigraphy, varying deformation intensity, structural styles and metamorphic grade. Kinematic analysis of structures and fabric of the fault zone rocks in these intracontinental thrust zones and the hanging wall and footwall rocks suggest spatially heterogeneous partitioning of strain into various combinations of E-W shortening, top-to-west shear on stratum parallel subhorizontal detachments or on easterly dipping thrusts, and a strike slip component Although relatively less prominent than the other two components of the strain triangle, non-orthogonal slickenfibres associated with flexural slip folds and mylonitic foliationstretching lineation orientation geometry within the arcuate NSB and NFB indicate left lateral strike slip subparallel to the overall N-S trend. On the whole an inclined transpression is inferred to have controlled the spatially heterogeneous development of thrust related fabric in the terrane between the Eastern Ghats belt south of the Godavari graben and the East Dharwar craton. © GEOL. SOC. INDIA.
Geetha R.S.,DRMGR Educational and Research Institute |
Keshavamurthy R.S.,Indira Gandhi Center for Atomic Research |
Harish R.,TCE Consulting Engineers Ltd
Annals of Nuclear Energy | Year: 2010
Bounds of asymmetric Doppler broadening function Χ(χ, θ) are obtained ab initio from application of Steffensen's inequality. It is shown how these bounds and their averages provide approximations for the function to any desired accuracy. These bounds along with similar bound approximations for Ψ(χ, θ) lead to bounds for temperature and energy derivatives of Doppler broadening functions. Accuracies of the approximations for the derivatives are also discussed. It is demonstrated that calculation of derivatives to desired accuracies require Ψ and Χ functions evaluated with higher relative accuracies. © 2010 Published by Elsevier Ltd.