Indian Institute of Technology Guwahati

About: Indian Institute of Technology Guwahati is a education organization based out in Guwahati, Assam, India. It is known for research contribution in the topics: Catalysis & Computer science. The organization has 6933 authors who have published 17102 publications receiving 257351 citations.

Beaconless position based routing with guaranteed delivery for wireless ad-hoc and sensor networks

Abstract: Existing position-based routing algorithms, where packets are forwarded in the geographic direction of the destination, normally require that the forwarding node knows the positions of all neighbors in its transmission range This information on direct neighbors is gained by observing beacon messages that each node sends out periodically Several beaconless greedy routing schemes have been proposed recently However, none of the existing beaconless schemes guarantee the delivery of packets Moreover, they incur communication overhead by sending excessive control messages or by broadcasting data packets In this paper, we describe how existing localized position based routing schemes that guarantee delivery can be made beaconless, while preserving the same routes In our guaranteed delivery beaconless routing scheme, the next hop is selected through the use of control RTS/CTS messages and biased timeouts In greedy mode, neighbor closest to destination responds first In recovery mode, nodes closer to the source will select shorter timeouts, so that other neighbors, overhearing CTS packets, can eliminate their own CTS packets if they realize that their link to the source is not part of Gabriel graph Nodes also cancel their packets after receiving data message sent by source to the selected neighbor We analyze the behavior of our scheme on our simulation environment assuming ideal MAC, following GOAFR+ and GFG routing schemes Our results demonstrate low communication overhead in addition to guaranteed delivery

Mathematical Modeling for Economic Evaluation of Electric Vehicle to Smart Grid Interaction

Abstract: The objective of this work is to develop a mathematical model for the integration of electric vehicle (EVs) to the grid. Integrating the EV with the grid would help in simultaneous charging of numerous EVs and provide peak hour energy to the grid (from EV). This bi-directional exchange of energy between the grid and EV results in a complex financial calculations. So a simple model has been proposed. The energy provided by the EV to the grid depends on the battery capacity. Battery capacity is affected by capacity losses (CL). The model includes the possible cases of CL, such as CL due to battery usage (discharge during vehicle transportation) and CL due to the grid interaction. The main cause for a higher per kilometer (Km) transportation cost in EV, when compared to conventional vehicle, is the high cost of the battery and its maintenance. In this model, the economic analysis has been done in such a way that the battery related liabilities do not become a financial burden to EV owners. The above scenario has been evaluated for different combinations of charge rate (Cr) and discharge rate (Dr) ranging from 1Cr-1Dr to 3Cr-3Dr. Finally the optimal cost of electricity is determined such that the grid, EV owners, and consumers (EV users) are benefitted.

Pyrolysis kinetics behaviour and thermal pyrolysis of Samanea saman seeds towards the production of renewable fuel

Abstract: The present study addresses pyrolysis behaviour and potential of Samanea saman seeds (SS) towards its bioenergy potential using thermogravimetric analyzer and in a cylindrical pyrolyzer (semi-batch reactor). Pyrolysis kinetic behaviour of biomass was carried out using Kissinger, Distributed Activation Energy Model (DAEM) and Miura-Maki-Integral method (MMI) while thermal pyrolysis was carried out in a cylindrical shaped semi-batch reactor. Kinetic results confirmed that the average activation energy was found 118.24 kJ mol−1, 168.70 kJ mol−1, and 97.87 kJ mol−1 for Kissinger, DAEM, and MMI model respectively. Further, thermal pyrolysis of SS biomass yielded 44.20 wt% yield of pyrolytic liquid (31.20 wt% pyrolytic oil/organic oil and 13 wt% aqueous fraction). Characterization results of pyrolytic oil showed the presence of higher viscosity (86.01 cSt), higher oxygen content (33.11%), and lower ash content (0.46 wt%) and gross heating value. FTIR analysis confirmed mainly the presence of aromatics, acid, alkene, water, and protein impurities. Gas Chromatography (GC) results declared, an increase in hydrocarbon and hydrogen gas with an increase in temperature while reduced the generation of CO and CO2. Further, GC-MS analysis of pyrolytic oil revealed the presence of higher acids (19.46%), phenols (11.01%) ethers (11.12%) and ester (7.33%) which is a potent source of oxygenated compounds. Characterization results of biochar showed the presence of higher gross heating value (23.14 MJ kg), carbon content (62.66%), volatile matter (34.15%) and lower moisture (5.14%) and BET surface area (8.20 m2 g−1). Combining these results, it can be suggested that SS biomass has the potential to produce renewable fuel and chemicals, while biochar can be used for various applications.