An Experimental Study on Mesh-and-Fiber Reinforced Cementitious Composites

Development of new composite materials which reduces the large consumption of natural resources is an approach towards sustainability. This study is an attempt to explore the possibility of adding polyolefin fibers (PL-F) in steel mesh reinforced cementitious composites (SMRCC) and conduct low velocity impact tests. For this purpose, test specimens of slab size 250 X 250 X 25 mm (thickness) were cast with steel mesh (3 to 5 layers) and polyolefin fibers (0.5-2.5% of  volume of specimens with 0.5% interval) and compared with control specimens (cast with steel mesh of 3 to 5 layers). Statistical t-tests were employed to find out the paired difference in impact energy absorption capacity between initial impact energy absorption (IIEA) and ultimate impact energy absorption (UIEA). Also, through statistical analysis, it was found that when steel mesh layers were varied keeping fiber percentage constant, and vice-versa, there were significant differences in the energy absorption capacity of cementitious slabs

Exergy Analysis of Operating Lignite Fired Thermal Power Plant

The energy assessment must be made through the energy quantity as well as the quality. But the usual energy analysisevaluates the energy generally on its quantity only. However, the exergy analysis assesses the energy on quantity as well asthe quality. The aim of the exergy analysis is to identify the magnitudes and the locations of real energy losses, in order toimprove the existing systems, processes or components. The present paper deals with an exergy analysis performed on anoperating 50MWe unit of lignite fired steam power plant at Thermal Power Station-I, Neyveli Lignite Corporation Limited,Neyveli, Tamil Nadu, India. The exergy losses occurred in the various subsystems of the plant and their components havebeen calculated using the mass, energy and exergy balance equations. The distribution of the exergy losses in several plantcomponents during the real time plant running conditions has been assessed to locate the process irreversibility. The Firstlaw efficiency (energy efficiency) and the Second law efficiency (exergy efficiency) of the plant have also been calculated.The comparison between the energy losses and the exergy losses of the individual components of the plant shows that themaximum energy losses of 39% occur in the condenser, whereas the maximum exergy losses of 42.73% occur in the combustor.The real losses of energy which has a scope for the improvement are given as maximum exergy losses that occurredin the combustor

Dynamic mechanical, thermal and wear analysis of Ni-P coated glass fiber/Al₂O₃ nanowire reinforced vinyl ester composite

Hybrid polymer composites nowadays are increasingly used in many engineering products which are subjected to wear, dynamic mechanical and thermal applications. So in the present study, we have investigated the evaluation of dynamic mechanical, thermal and wear properties of vinyl ester hybrid composite strengthened with Ni-P coated E-glass fiber and Al₂O₃ nanowires as reinforcement at different concentrations. Nickel-Phosphorus is plated over the glass fiber substrate by means of the electroless plating method. The best optimum bath composition was determined after many trials and used for the proper plating process. From the outcome of the result, it is clear that the storage modulus has a trend to increase with increase in the concentration of Ni-P coated glass fiber (GF) and further increases when Al₂O₃ nanowires are used as the reinforcement. The glass transition temperature is also shifted to the higher temperature in the process. From the thermogravimetric analysis, it is clear that the thermal stability of the composite steps up with the addition of Al₂O₃ nanowires as fillers and Ni-P/GF as reinforcement. The wear properties are analyzed and the morphology of the coated and worn-out surfaces are studied by means of scanning electron micrographs and optical microscope images. Keywords: Hybrid composite, Al₂O₃ nanowire, Electroless Ni-P, Dynamic mechanical analysis, Wea