Faculty Publications
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Item Assessment of Ionic Composition of Fresh Cement Blends System with Addition of SCMs and Conductive Materials(Springer Science and Business Media Deutschland GmbH, 2024) Rakesh Kumar, N.; Sundaramoorthi, S.; Palanisamy, T.In this experimental study, an attempt has been made to investigate the effect on the ionic composition of cement system at early age upon the addition of supplementary cementitious materials (SCMs) and conductive additives. The ionic composition of cement system refers to the type and concentration of ionic species and it varies depending on the type of cement and degree of hydration. Cement system containing fly ash, silica fume, and ground granulated blast furnace slag (GGBS) in different proportions were blended to examine the effect of SCMs on the ionic concentration. Apart from SCMs, conductive additives like graphite powder and inorganic salt were also included in the study. The pore solution, formed as a result of the hydration of cement, contains a complex mixture of ions. The ionic conductivity of the pore solution is determined from the concentration of various ionic species. Ionic conductivity is responsible for the electrical, chemical, and mechanical performance of the cement system, and hence, understanding the same is essential. Pore solution is extracted in the early age of the hydrating cement system by centrifugation, and with ion chromatographic technique, the concentrations of ions in the pore solution are determined and the results and discussion are compiled in this paper. From the study, silica fume and magnesium-based salt were observed to be an effective additive in improving the conductivity of the pore solution. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.Item Source apportionment of PM2.5 particles: Influence of outdoor particles on indoor environment of schools using chemical mass balance(AAGR Aerosol and Air Quality Research hhyang@cyut.edu.tw, 2017) Kalaiarasan, G.; Mohan Balakrishnan, R.M.; Sethunath, N.A.; Manoharan, S.Children have higher lung function than adults and they spend most of their day time in schools. Also, children studying at schools located in the vicinity of busy roadways are vulnerable to childhood asthma and respiratory disorders. The present study is focused on estimating the sources of PM2.5 particles present in the indoor air quality in schools which are located adjacent to urban and suburban roadways. The indoor PM2.5 samples from all the four schools were collected using fine dust sampler from 8 a.m. to 4 p.m. The sampling was carried out for one complete week during various seasons including both working and non-working days. The chemical compositions of the PM2.5 samples were analyzed for certain elements like Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sr, Ti, V and Zn using Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES) and ions like F-, Cl-, NO3-, PO43-, SO42-, K+, Ca2+, Mg2+, NH4+, Na+ using Ion Chromatography (IC). Source apportionment study using Chemical Mass Balance was carried out using the species concentration of the collected samples. The major sources were found to be Paved Road Dust, Soil Dust, Gasoline Vehicle Emissions, Diesel Vehicle Emissions and Marine Source Emissions. Among these, vehicular emissions contribution was found to be higher for the schools located close to roadways rather than the school located at a considerable distance from highway. The difference in source type contribution at each school clearly depicts the difference in nature of location and type of activities in the vicinity of the sampling sites. © Taiwan Association for Aerosol Research.Item Source apportionment studies on particulate matter (PM10 and PM2.5) in ambient air of urban Mangalore, India(Academic Press, 2018) Kalaiarasan, G.; Mohan Balakrishnan, R.M.; Sethunath, N.A.; Manoharan, S.Particulate matter (PM10 and PM2.5) samples were collected from six sites in urban Mangalore and the mass concentrations for PM10 and PM2.5 were measured using gravimetric technique. The measurements were found to exceed the national ambient air quality standards (NAAQS) limits, with the highest concentration of 231.5 ?g/m3 for PM10 particles at Town hall and 120.3 ?g/m3 for PM2.5 particles at KMC Attavar. The elemental analysis using inductively coupled plasma optical emission spectrophotometer (ICPOES) revealed twelve different elements (As, Ba, Cd, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Sr and Zn) for PM10 particles and nine different elements (Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sr and Zn) for PM2.5 particles. Similarly, ionic composition of these samples measured by ion chromatography (IC) divulged nine different ions (F?, Cl?, NO3 ?, PO4 3?, SO4 2?, Na+, K+, Mg2+ and Ca2+) for PM10 particles and ten different ions (F?, Cl?, NO3 ?, PO4 3?, SO4 2?, Na+, NH4 +, K+, Mg2+ and Ca2+) for PM2.5 particles. The source apportionment study of PM10 and PM2.5 for urban Mangalore in accordance with these six sample sites using chemical mass balance model (CMBv8.2) revealed nine and twelve predominant contributors for both PM10 and PM2.5, respectively. The highest contributor of PM10 was found to be paved road dust followed by diesel and gasoline vehicle emissions. Correspondingly, PM2.5 was found to be contributed mainly from two-wheeler vehicle emissions followed by four-wheeler and heavy vehicle emissions (diesel vehicles). The current study depicts that the PM10 and PM2.5 in ambient air of Mangalore region has 70% of its contribution from vehicular emissions (both exhaust and non-exhaust). © 2018 Elsevier LtdItem Optimising cement-based electrolytes: Ionic strength analysis and electrical performance in cement-based battery applications(Taylor and Francis Ltd., 2025) Sundaramoorthi, A.; Thangaraju, P.A fully developed and commercialised cement-based battery system has the potential to revolutionise building technology. This paper evaluates the performance of cement-based batteries and explores the effect of adding Supplementary Cementitious Materials (SCMs) like fly ash, silica fume and blast slag, and ion-conductive particles, with copper and aluminium as electrode combinations. Cement-based matrix as the electrolyte of the developed battery system, is characterised for its ionic strength and is correlated to the electrical performance of the system. The solid phase of the different electrolyte mixes is also characterised using FE-SEM and XRD. Electrical performance parameters like open circuit voltage, discharge performance under constant current rate, and capacity measurements of devised battery systems are reported in this paper. The combination of cement with silica fume at 5%, along with epsomite (SF5) resulted in a 250% (approx.) higher discharge life and capacity in comparison to the control system (CM45). The ionic strength of the pore solution also showed a strong positive correlation (R2 = 0.92) with the discharge life across all mixes, highlighting its critical role in the battery system’s performance. The SF5 mix also showed sufficient mechanical stability with a compressive strength of 19.3 and 29.4 MPa at 7-d and 28-day, respectively. © 2025 Informa UK Limited, trading as Taylor & Francis Group.Item Bioprospecting indigenous bacteria from landfill leachate for enhanced polypropylene microplastics degradation(Elsevier B.V., 2025) Dubey, A.P.; Thalla, A.K.Plastic pollution, especially microplastics (MPs), is a severe environmental threat. Due to the significant environmental issues posed by plastics, it is critical to use an effective and sustainable degradation technique. The study aimed to isolate and identify Indigenous bacterial strains from landfill leachate (LL) to evaluate its potential for degrading Polypropylene microplastics (PPMPs). The investigation identified two bacterial strains, Pseudomonas aeruginosa, and novel Staphylococcus haemolyticus, through 16S rRNA analysis, capable of decomposing PPMPs. Following a 30-day treatment period, it was noted that Staphylococcus haemolyticus reduced the dry weight of PPMPs by 25.46 % ± 1.35 %, whereas Pseudomonas aeruginosa strain reduced it by 7.01 % ± 0.85 %. Multiple tests, including weight loss, pH, optical density, total biomass yield, and BATH test of the medium, validated the growth of bacterial strains. The biochemical characteristics of the isolated strains were assessed through Biochemical tests. The study also investigated the surface, chemical, and structural changes in treated PPMPs using Scanning electron microscopy (SEM), Energy-Dispersive X-ray spectroscopy (EDS), X-ray diffractometer (XRD), and Ion Chromatography (IC) tests. The Fourier Transform Infrared Spectroscopy (FTIR) study also showed the creation of alcohol, methyl, as well as carbonyl groups due to hydrolysis and oxidation by both bacterial strains. This study implies that the Staphylococcus haemolyticus and Pseudomonas aeruginosa bacterial strains are secure and efficient for PPMP bioremediation. © 2025 Elsevier B.V.