Faculty Publications
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Item Preparation and characterization of novel PSf/PVP/PANI-nanofiber nanocomposite hollow fiber ultrafiltration membranes and their possible applications for hazardous dye rejection(Elsevier, 2015) Kajekar, A.J.; Dodamani, B.M.; Isloor, A.M.; Zulhairun, A.K.; Cheer, N.B.; A.F., A.F.; Shilton, S.J.In the present study, PANI (polyaniline)-nanofibers were synthesized by interfacial polymerization technique, dispersed in n-Methyl-2-Pyrrolidone (NMP) solvent and blended with PVP (Polyvinylpyrrolidone)/PSf (Polysulfone) for preparing the novel hollow fiber membrane by dry-wet spinning technique. The newly prepared nanocomposite ultrafiltration hollow fiber membrane is characterized by Scanning Electron Microscope (SEM), Contact Angle, Zeta Potential and Differential Scanning Calorimeter (DSC). Filtration studies are conducted to measure the membrane pure water flux (PWF), rejection of hazardous dye (Reactive Red 120) and fouling resistance. The maximum rejections are obtained for M 0.5 membrane with 99.25% rejection of RR120 hazardous dye at 2. bar pressure. The pure water flux, percentage rejection, antifouling property and thermal resistance increased with an increase in PANI-nanofiber concentration. The contact angle of the membrane decreased with increasing PANI-nanofiber concentration, which indicated increased hydrophilicity of the new membranes. © 2015 Elsevier B.V.Item Performance and emission analysis of a single cylinder CI engine using Simarouba glauca biodiesel(Springer Heidelberg, 2017) Bedar, P.; Chitragar, P.R.; Shivaprasad, K.V.; Kumar, G.N.It is well known fact that diesel engines are commonly used for transportation and power generation due to their high efficiency, low fuel consumption and durability. On contrary these engines churn out harmful and hazardous emissions like particulate matter (PM) and nitrogen oxides (NOx). Recently Bio-origin renewable fuels have taken center stage of discussion because of their ability to replace depleting fossil fuels and capacity to reduce hazardous engine exhausts emissions when used in diesel engines. In the present experimental study Simarouba glauca biodiesel is used in a naturally aspirated four stroke single cylinder air cooled direct injection kirloskar DA10 engine. The main objective is to investigate the effect of biodiesel and exhaust gas recirculation (EGR) on the performance and emission characteristics of a CI engine at 180 bar fuel injection pressure (FIP) with standard injection timing. B20, B40 biodiesel blends with 10, 15 and 20% EGR ratios were used for the study to investigate brake thermal efficiency (BTE), carbon monoxide (CO), unburned hydrocarbons (UBHC), NOx, and smoke opacity. Reduction in CO, HC and smoke opacity is noticed with simarouba biodiesel fuel while increasing NOx compared to diesel. Application of EGR along with biodiesel resulted in simultaneous reduction of nitrogen oxides and smoke without affecting engine performance. It was found from experiment that B20 blend at 15% EGR shown superior performance characteristics compared to other conditions. © Springer India 2017.Item Efficient treatment of hazardous reactive dye effluents through antifouling polyetherimide hollow fiber membrane embedded with functionalized halloysite nanotubes(Taiwan Institute of Chemical Engineers, 2017) Hebbar, R.S.; Isloor, A.M.; Zulhairun, A.K.; Sohaimi Abdullah, M.; A.F., A.F.A simple, efficient and scalable approach was developed for the fabrication of highly fouling resistance nanocomposite hollow fiber membranes with the aim of effective removal of environmentally detrimental reactive dyes. The naturally occurring halloysite nanotubes were functionalized via facile self-polymerization of m-aminophenol in mild acidic condition and employed as a hydrophilic additive. The chemical modification was confirmed by FTIR, TEM and energy dispersed X-ray (EDX) analysis. The hybrid nanocomposite membrane was prepared by dry–wet spin technique with different additive dosage. The resultant membrane was characterized in terms of contact angle, surface energy, porosity, zeta potential, elemental mapping and morphology. The permeation experiments illustrated superior water flux of 104.9 Lm?1 h?1 and 9.6% of irreversible fouling with more than 90.3% of flux recovery by the simple hydraulic cleaning. Most importantly, prepared membrane was subjected for hazardous reactive dye removal application with different experimental parameters. The hybrid membrane with 2 wt. % of additive concentration showed more than 97% and 94% for the Reactive Red 102 and Reactive Black 5 dyes respectively. This approach may also be very useful in developing high flux, fouling resistant ultrafiltration hollow fiber membranes for the other similar type applications such as hemodialysis membranes. © 2017 Taiwan Institute of Chemical EngineersItem Fabrication of novel PPSU/ZSM-5 ultrafiltration hollow fiber membranes for separation of proteins and hazardous reactive dyes(Taiwan Institute of Chemical Engineers, 2018) Nayak, M.C.; Isloor, A.M.; Moslehyani, A.; Ismail, N.; A.F., A.F.Polyphenylsulfone (PPSU) based asymmetric hollow fiber membranes were prepared by the addition of different percentages of ZSM-5 particles by diffusion induced phase separation method. Polyvinylpyrrolidone (PVP) was used as a pore forming agent. The fabricated membranes were characterized by Field Emission scanning electron microscopy (FESEM), Energy Dispersive Spectroscopy (EDS), contact angle, water permeability, water uptake and by porosity measurements. Membranes filtration study was performed using different proteins namely bovine serum albumin (BSA), egg albumin (EA) and hazardous dyes like Reactive black 5 (RB-5), Reactive orange 16 (RO-16) in aqueous solutions. It was found that, addition of ZSM-5 in membrane matrix showed better dye removal capacity because of its hydrophilic and adsorptive nature. The membrane (PZ-3) with higher loading of additive exhibited rejection percentages of 100% for BSA, 95.23% for EA proteins and with reactive dyes 90.81% for RB-5 and 82.84% for RO-16 as compared to the pristine HF membrane. © 2017 Taiwan Institute of Chemical EngineersItem Probabilistic Seismic Hazard Assessment of Mangalore and Its Adjoining Regions, A Part of Indian Peninsular: An Intraplate Region(Birkhauser Verlag AG, 2019) Shreyasvi, C.; Venkataramana, K.; Chopra, S.; Rout, M.M.The Southwestern part of India investigated in the present study mainly comprises of states such as Goa, north Kerala and a major portion of Karnataka. A comprehensive regional seismic catalog has been compiled spanning over 190 years apart from a few prehistoric events from the early 16th century. The classical Cornel–McGuire approach has been incorporated in the estimation of seismic hazard. The seismic sources are modeled as area sources and the entire study region is divided into four seismogenic source zones. The uncertainties involved in the formulation of the seismic source model and ground motion prediction model has been discussed in detail. Further, the procedure for selecting appropriate GMPEs involves the evaluation of multidimensional (M, R, T) ground motion trends and performance against observed macroseismic data. The epistemic uncertainty in the estimation of seismicity parameters and ground motion prediction equations (GMPEs) has been addressed using logic tree computation. The results of the hazard analysis demonstrate that the existing seismic code underestimates the seismic potential of seismic zone II (BIS 1893) areas. The de-aggregation of the predicted seismic hazard revealed earthquakes of magnitude range (Mw) 4–6 occurring within a distance of 35kms to be most influential for any given site of interest. Sensitivity analysis has been performed for crucial input parameters in the formulation of seismic source and ground motion models. Site amplification study has been carried out using topographic slope as a proxy to shear velocity in the top 30 m (Vs30). A maximum of 60% to 80% amplification has been observed in the study area. The seismic hazard maps in terms of PGA have been plotted for the seismic hazard estimated at the bedrock level as well as the surface level for 2% and 10% probability of exceedance in 50 years. The hazard estimation specifically for the southern part of the west coast is the first of its kind. The investigation suspects mining-induced seismicity in Bellary and Raichur districts though there is no mention of this in the prior literature. © 2019, Springer Nature Switzerland AG.Item Local site effect incorporation in probabilistic seismic hazard analysis – A case study from southern peninsular India, an intraplate region(Elsevier Ltd, 2019) Shreyasvi, C.; Venkataramana, K.; Chopra, S.The inclusion of local site effects into seismic hazard analysis is an important issue and has been attempted previously in both deterministic and probabilistic manner. The present study is an attempt to combine the local site response with the standard probabilistic seismic hazard analysis. The site response was computed by performing an equivalent linear analysis in the frequency domain. The input soil profiles for the analysis were taken from the borehole data of the North Kerala region (one of the Southerly states in India). The uncertainty in estimating the shear velocity profile (VS) has been addressed by applying multiple VS–N correlations. The variability in the choice of input motions has been reduced by selecting multiple ground motions representing distinct hazard levels (return period of 50–2000 years). The uniform hazard spectrum developed for the host reference site conditions has been adjusted to the target region and the input motions are scaled accordingly. The analyzed soil profiles were categorized into three distinct soil types namely ‘Sand’, ‘Clay’ and ‘All soil’ based on the predominant soil content. The empirical amplification equation as a function of input rock spectral acceleration (Sa r) was developed for each soil type. ‘Sand’ exhibits nonlinear behavior for Sa r > 0.1 g whereas ‘clay’ demonstrates sustained amplification at longer periods. The average spectral amplification observed is 3 for ‘All soil’, 5 for ‘clay’ and 3.5 for ‘sand’ in the study region. The regionally developed amplification function aids in transforming a Ground Motion Prediction Equation (GMPE) from generic to site-specific. The modified GMPE is integrated with the regional seismic source model to estimate site-specific probabilistic seismic hazard. The study produces site-specific spectrum and surface hazard maps which can be of direct use to planners and designers in creating a seismic resilient built environment. © 2019 Elsevier LtdItem Assessment of Cooling Performance of Neem Oil for Distortion Control in Heat Treatment of Steel(Springer, 2020) Pranesh Rao, K.M.; Prabhu, K.N.Growing concerns over the hazardous impact of mineral oil-based industrial quench media on human health and the environment have forced researchers to seek renewable and non-hazardous alternatives. Non-edible vegetable oil-based quench media are perceived to be a potential replacement for mineral-based industrial quench media. The present work focuses on assessing the cooling performance of neem oil as compared to commercial hot oil quench media. Inconel and steel probes were used to characterize the cooling performance of these quench media maintained at bath temperatures 100 °C, 150 °C and 200 °C. The heat extraction rates and uniformity of heat extraction in Inconel probes quenched in neem oil were observed to be substantially higher at all bath temperatures. The hardness of AISI 52100 steel probe quenched in neem oil at all bath temperatures was observed to be higher. The pearlitic microstructure was observed in the steel probe quenched in hot oil maintained at 200 °C bath temperature. In contrast to this, a mixture of bainite, martensite and carbide was observed in case of steel probes quenched in neem oil maintained at 200 °C. Oxidation experiments revealed that neem oil is susceptible to an increase in viscosity due to oxidation. An increase in the viscosity by about 15% was observed in the case of neem oil as compared to only 4% increase in viscosity of hot oil. However, after an initial increase, the viscosity of neem oil stabilized and further no significant change in viscosity due to oxidation were observed. Oxidation had no significant effect on the cooling performance hot neem oil quench medium, and thus, it can be considered as an effective replacement for hot oil. © 2020, ASM International.Item Probabilistic seismic hazard analysis of North and Central Himalayas using regional ground motion prediction equations(Springer Science and Business Media Deutschland GmbH, 2021) Ramkrishnan, R.; Kolathayar, S.; Sitharam, T.G.Recently developed region-specific GMPEs are used for a comprehensive seismic hazard analysis (SHA) of the North and Central Himalayas (NCH) using a probabilistic approach considering two source models. Vulnerable seismic sources in the areas are identified based on the Seismotectonic Atlas (Dasgupta et al. 2000), published by the Geological Survey of India. An up to date, homogenized and declustered earthquake catalogue is compiled from various sources, with earthquake data since 250 BC, to create a new digitized seismotectonic representation of the region. Regional seismic zones having similar seismicity are recognized based on the Gutenberg-Richter (GR) parameters and the region is delineated into 5 seismic zones. The study area is divided into grids of size 0.05° × 0.05° and the hazard in terms of Peak Ground Acceleration (PGA) at the centre of each grid point is estimated and presented as hazard maps for individual seismic sources, maximum of all sources, and average of both sources. From the current study, it could be concluded that the PGA estimated in the regions is comparatively higher than what is reported in the codal provisions for seismic zonation and estimation of design horizontal acceleration for the region. © 2021, Springer-Verlag GmbH Germany, part of Springer Nature.Item Photonic crystal fiber sensor for the detection of hazardous gases(Springer Science and Business Media Deutschland GmbH, 2022) Nizar, S.M.; Elizabeth Caroline, E.C.; Krishnan, P.Three different Photonic Crystal Fiber (PCF) gas sensors are designed to detect five different gases for a wide range of wavelengths. The three unique configurations are designed based on four outer Elliptical cores PCF (4E-PCF), four outer Circular cores (4C-PCF) PCF, and different Eight Elliptical cores PCF (8E-PCF) to analyze and sense the light interface with applied gases. For three proposed gas sensors, the sensing parameters for five different hazardous gases, such as relative sensitivity, effective area, birefringence and dispersion, are acquired. The five different gases considered in the sensor investigation are Sulfur trioxide [SO3] (20 °C), Tetracholorosilane [SiCl4], Tetracholoromethane [CCl4], Turpentine [C10H16], Tin Terra chloride [SnCl4]. Among the three designs, 8E-PCF yields a maximum sensitivity of 75.75%, an effective area of 2.45μm2, and a birefringence of 0.0421 for SnCl4 gas. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Item Multihazard Assessment of the Sutlej-Beas River Basin Using Bivariate Statistical Frequency Ratio (FR) Model and Management Barriers of Land-River Interface(Springer Science and Business Media Deutschland GmbH, 2023) Rehman, S.; Azhoni, A.Climate change coupled with increased anthropogenic activities intensifies the potency and frequency of extreme weather events. While multihazard assessments of these extreme weather events enhance the estimation of hazard susceptibility, it must be coupled with identifying institutional barriers of managing the land-river interface. Thus, this study has carried out a multihazard susceptibility assessment based on landslide and flood susceptibility in the Sutlej-Beas River basin and prepared flood and landslide susceptibility maps using eleven causative parameters through a bivariate statistical frequency ratio (FR) model. This statistical evaluation of hazard susceptibility from multiple factors is supplemented by identifying the key barriers of managing the land-river interface, producing a more comprehensive understanding of the challenges of mitigating extreme weather-related hazards in a river basin. Nearly 51% of the study area was identified as susceptible to landslide while 43% was under flood and 48% area was observed under multihazard susceptibility. Landslides, floods, and multihazard followed a similar pattern of spatial distribution where elevation, population, drainage density, stream power index (SPI), and rainfall were identified as the contributing parameters. Changing attitudes of people toward rivers, lack of coordination among different stakeholders, and deficit funds were identified as prominent barriers in the case of land-river management. Susceptibility maps generated in this study will help in identifying the areas under hazard susceptibility while the identified institutional barriers may guide towards contextual sustainable planning of the basin and attainment of sustainable development goals. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.