Dynamic Response of Heterogeneity and Reinforcement on the Propagation of Torsional Surface Waves

This paper aims to investigate the effect of reinforcement and heterogeneity on the propagation of torsional surface waves. Geometry of the problem is consists of heterogeneous fibre-reinforced layer lying over a heterogeneous isotropic half-space. Heterogeneity in the layer is caused due to exponential variation of elastic parameters whereas quadratic variation in elastic parameters is considered for half-space. Dispersion relation for torsional surface waves has been obtained and matched with classical Love wave equation by taking an isotropic homogeneous layer lying over an isotropic homogeneous half-space. Some existing results have been deduced as particular case of the present study. Velocity profile of surface waves is compared for both, reinforced and reinforced free cases. Numerical examples have been discussed by taking steel fibre-reinforced material. Graphical representation has been made to exhibit the findings

Influence of Torrefaction on Lignocellulosic Woody Biomass of Nigerian Origin

Torrefaction process is a thermal treatment that can improve quality of lignocellulosic biomass into a carbon-rich and hydrophobic feedstock which is applicable as fuel and metallurgical reductant. Biomass (Melina and Teak wood) of Nigerian origin was subjected to mild (240o C) and severe (300o C) torrefaction treatment at different residence times (30 and 60 min) and particle sizes (+0.5 - 2 mm and +4 - 6.35 mm). Raw biomass and biochar from torrefaction were subjected to proximate, ultimate, higher heating value and SEM analyses. The mass yield obtained for mild treatment conditions for both biomass was in the range of 72 - 84 (wt. %) compared to 40 - 54 (wt. %) under severe treatment conditions. However, 33 - 56 % increment in higher hating value was observed for severe treatment conditions as against 11 - 17 % of mild treatment condition. This ultimately led to a 60 - 72 (wt. %) energy yield for severe treatment conditions and 73 - 94 (wt. %). The fixed carbon content increased from the range of 8 - 11 (wt. %) to 20 - 61 (wt. %) after torrefaction. The volatile matter content under mild condition was reduced by 7 - 10 % for both biomass as against 41 - 47 % under severe treatment condition. The fuel ratio increased from 0.11 and 0.15 for Melina and Teak woods respectively to a range of 0.22 - 0.25 for mild treatment conditions and 0.97 - 1.75 for severe treatment condition. The H/C and O/C atomic ratios of biochar were lowered towards that of sub-bituminous coal and peat. A honey-comb-like structure with cylindrical holes were observed for biochar compared to the fibrous and spongy nature of the raw biomass. Biomass of Nigerian origin were improved under torrefaction and thus can be suitable as feedstock in thermal or metallurgical applications

HEAT TRANSFER AND FLOW FRICTION CHARACTERISTICS OF SOLAR WATER HEATER WITH INSERTED BAFFEL INSIDE TUBE

ABSTRACT Experimental investigation of friction factor and heat transfer characteristics of thermosyphone solar water heater with flat plate solar collector fitted with full length baffle of 10cm pitch have been presented. The flow regime is laminar for this study with the Reynolds number range 124 to 258. The experimental data obtained were compared with those obtained from plain tube data. The effects of full length baffle inside the tube on heat transfer and friction factor were presented. The heat transfer coefficient enhancement for baffle creates is higher than that of plain tube for a given Reynolds number. The use of baffle created improved the performance of thermosyphone solar water heater

Optical detection of a GMRT-detected candidate high-redshift radio galaxy with 3.6-m Devasthal optical telescope

Large scale structure and cosmolog

AstroSat detection of Lyman continuum emission from a z = 1.42 galaxy

Large scale structure and cosmolog