2,501 research outputs found
Biomass Production for Energy in India: Review
This paper presents a general view about biomass production in India and its potential energy for use in different fields. India has tremendous potential for energy generation through biomass and its residues. Biomass energy is normally produced from firewood, agricultural residues such as bagasse, crop stalks, animal dung and wastes generated from agro-based industries. With the estimated and predicted values, the generating power from the surplus biomass in India was significant and it will continue to be more effective in future. Residue use as a fuel in India is estimated to be 216 Mt as projected value in 2010, recently, around 605 MW of electricity is being produced from biomass firing and 720 MW from cogeneration activities for residue. About 185 Mt (40%) of the dung collected is used as fuel in cook stoves. The potential for biogas production annually is 8750 million m3 from 251 Mt of dung. The amount of fuel-wood consumption during year 2004 was 205 million tonnes used as fuel for traditional cook stoves with low efficiency, 16 Mt used in industrial sector producing 10 PJ, and it was estimated that the production of fuel wood and charcoal increased to the rate of 1.98 per cent per annum. The total quantity of solid wastes generated in larger towns and cities has been estimated at 40 Mt in 2001, and in 2005 the average MSW generation in overall India was approximately 100,000 Mt/day. For the wastewater in India, in 2010, the energy estimated to be around 3929.8 TJ as energy value of CH4
A foundation for analytical developments in the logarithmic region of turbulent channels
An analytical framework for studying the logarithmic region of turbulent
channels is formulated. We build on recent findings (Moarref et al., J. Fluid
Mech., 734, 2013) that the velocity fluctuations in the logarithmic region can
be decomposed into a weighted sum of geometrically self-similar resolvent
modes. The resolvent modes and the weights represent the linear amplification
mechanisms and the scaling influence of the nonlinear interactions in the
Navier-Stokes equations (NSE), respectively (McKeon & Sharma, J. Fluid Mech.,
658, 2010). Originating from the NSE, this framework provides an analytical
support for Townsend's attached-eddy model. Our main result is that
self-similarity enables order reduction in modeling the logarithmic region by
establishing a quantitative link between the self-similar structures and the
velocity spectra. Specifically, the energy intensities, the Reynolds stresses,
and the energy budget are expressed in terms of the resolvent modes with speeds
corresponding to the top of the logarithmic region. The weights of the triad
modes -the modes that directly interact via the quadratic nonlinearity in the
NSE- are coupled via the interaction coefficients that depend solely on the
resolvent modes (McKeon et al., Phys. Fluids, 25, 2013). We use the hierarchies
of self-similar modes in the logarithmic region to extend the notion of triad
modes to triad hierarchies. It is shown that the interaction coefficients for
the triad modes that belong to a triad hierarchy follow an exponential
function. The combination of these findings can be used to better understand
the dynamics and interaction of flow structures in the logarithmic region. The
compatibility of the proposed model with theoretical and experimental results
is further discussed.Comment: Submitted to J. Fluid Mec
Comparative Analysis of the Relative Similarities and Differences in the Educational Systems of United States and South Africa Facilitating or Impeding Educational Mobility
A crucial role of education is the function of transmitting culture and prepare the young for a vocation and assuming a productive role in a social system. In some cultures, education provides means for earning a living. For example, education to many Africans (Foster:1980), is viewed in very pragmatic and instrumental terms. The reason for going to school is necessary to obtain suitable employment. Education as a liberal framework is foreign to most Africans
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