Browsing by Author "Babunarayan, K.S."

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Evaluation of pyrolyzed areca husk as a potential adsorbent for the removal of Fe2+ ions from aqueous solutions
(2019) Sheeka, Subramani, B.; Shrihari, S.; Manu, B.; Babunarayan, K.S.
The hurdle of valorisation of Arecanut husk on one side and the pollution of aquatic bodies by heavy metals like Iron on the other end are contemplated together in this study. The areca husk is pyrolyzed at 450°C for two hours to obtain Biochar. Batch adsorption studies were employed to investigate the effect of adsorbent dosage (2-10 g/l), initial concentration of adsorbate (1-5 mg/l) and contact time (30 -360 min) at temperature of 28±2 °C & pH4.0±0.2 on the removal of Iron from pyrolyzed areca husk. The adsorption capacity was found to increase with increase in initial Iron concentartion and contact time, but decreases with the adsorbent dosage. Langmuir, Freundlich, Temkin and Dubinin-Radushkevich Isotherms was used to analyse the equilibrium data. Langmuir and Dubinin-Radushkevich model best describe the uptake of Iron ions implying a monolayer adsorption with physisorption. Pseudo second order, exhibited the best fit for the effectiveness of Iron adsorbtion indicating the maximum limit of chemisorption. Thermodynamic studies indicated that the adsorption was spontaneous and exothermic in nature. The mechanisms responsible for adsorption of Iron on pyrolysed areca husk was conducted by SEM-EDAX, XRD and FTIR indicating oxidation and precipitaion of Iron into complex compounds of jarosite and ferrous hydroxy sulphates. In conclusion, pyrolyzed areca husk can be technically & economically feasible alternative adsorbent material.
Experimental studies on the effects of corrosion on the flexural strength of RC beams
(2014) Pandit, P.; Venkataramana, K.; Babunarayan, K.S.; Parla, B.; Kimura, Y.
RC structures are generally very durable and are capable of withstanding a variety of adverse environmental conditions. However, failures of these structures still occur and reinforcement corrosion is one of the major causes. In the present research, corroded Ordinary Portland Cement (OPC) beams were tested in the laboratory to evaluate their flexural behavior. Accelerated corrosion technique was adopted to corrode the beams. The corrosion was measured using Applied Corrosion Monitoring (ACM) instrument. From the results, it is seen that, as the rate of corrosion increases, the load carrying capacity decreases. The deflection increases initially and then decreases. It is observed that the stiffness of the beams is reduced when rate of corrosion is increased due to changes in the modulus of elasticity of corroded steel. 2014 CAFET-INNOVA TECHNICAL SOCIETY.
Significance of modeling techniques in pushover analysis of RC buildings
(2010) Thapa, M.; Babunarayan, K.S.; Halemane, K.P.; Venkataramana, K.; Yaragal, S.C.; Ramesh, Babu, R.; Sharma, A.; Reddy, G.R.
The study presented here focuses on the effectiveness of the models adopted for the nonlinear static pushover (NSP) analysis and providing the best model that can predict the nonlinear response of RC buildings with sufficient accuracy with respect to the experimentally obtained results. NSP analysis considers material nonlinearity and is an effective tool to evaluate the performance of the structure under lateral seismic loads. However, the actual test data in order to verify the results of NSP analysis are very rare for RC structures, which are analytically sensitive to the models and procedure adopted by the analyzer. Under the present work three cases of geometric models; a) Frame with beamcolumn elements, b) Frame with beam-column elements and slabs modelled as a rigid diaphragm and c) Frame with beam-column elements and slabs modelled as shell element considering concrete as confined and unconfined were analyzed. Comparision of analytical curve with the experimental pushover curve, clearly suggests that frame modelled as confined beam-column elements and slabs modelled as a rigid diaphragm gives closer results. 2010 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.