Faculty Publications

Now showing 1 - 3 of 3

Biological components and inflammatory responses of particulate matter from biomass burning houses
(International Society of Indoor Air Quality and Climate, 2017) Gangamma, S.; Desai, S.; Tripathi, D.K.; Vishnu Priya, D.; Krishnaja, S.
[No abstract available]
Investigations on the thermal actuation of carbon black reinforced pdms composite uni-layer and bi-layer cantilever beams
(ModTech Publishing House office@hotelfloramamaia.ro, 2020) Hiremath, H.; Desai, S.; Kulkarni, S.M.; Karanth P, N.; Desai, V.
Actuators are the essential components of robots, switches, relays, and many other automatic systems. There are various actuator types based on material, geometry, and stimulus. Nowadays, polymer composite based actuators are gaining importance due to their flexibility, ease of processing, low cost, and easy way of tailoring the properties. Among the polymers, Polydimethylsiloxane (PDMS) is one of the promising polymers for the actuator. In the present study, unilayer and bilayer cantilever beams of PDMS based composite subjected to a thermal stimulus are investigated. The Finite Element (FE) and the analytical models are developed for unilayer and bilayer polymer composite beams and simulated for actuator response. The deflection behavior of these beams is investigated for a temperature input range of 308K to 368K. The beams are analyzed for varying Carbon Black(CB) content from 5 to 25 Vol% in PDMS polymer and beam thickness from 1mm to 5mm. It is observed that with an increasing percentage of filler content, the increment in deflection of the bilayer beam is appreciably higher when compared to the unilayer beam. For 25 Vol% of CB, the bilayer beam shows 11.48 times improvement in deflection value. Also, it is noticed that the thickness of the beams influences deflection more compared to the percentage of the CB content. The deflection of the unilayer and bilayer beam is observed to increase linearly with temperature input. At 368K, the bilayer beam deflection is 6.87 times greater than the unilayer. Hence this analysis is the baseline for predicting the actuator performance of the unilayer and bilayer polymer composite beams considering the set of variables. © International Journal of Modern Manufacturing Technologies.
A multivariate index-flood approach for flood frequency analysis of ungauged watersheds: a case study on state of Kerala in India
(Springer Science and Business Media Deutschland GmbH, 2025) HariKrishna, M.; Vinod, D.; Desai, S.; Mahesha, A.
The multivariate index-flood method (MIF) advances flood risk evaluation at ungauged watersheds by utilizing information from gauged sites within a uniform region to forecast flood attributes where direct data is absent. It aims to enhance flood frequency analysis at ungauged watersheds by considering the interdependence between multiple flood variables using copulas and multivariate quantile curves. The proposed methodology involves screening data for anomalies, delineating homogeneous regions based on physiographic and hydrological descriptors, and selecting appropriate regional marginal distributions and copulas. Regional Flood Frequency Analysis and the index-flood method, MIF, can produce dependable multivariate quantile approximations, enhancing the precision of flood projections and risk evaluations at ungauged watersheds. Nine watersheds in the Indian state of Kerala situated along rivers flowing westward have been subjected to the suggested multivariate technique, which focuses on the bivariate case. This implementation involves recorded data series on flood volume and peak flow. The dataset includes daily maximum discharge data from India-WRIS, gridded precipitation and temperature data from IMD, and a 30 × 30 m DEM from USGS SRTM. The data record span 31–39 years. Subsequently, given a specific return period, a set of occurrences where volume and peak fall within a bivariate quantile curve is established at a designated watershed. The quantile curves derived from the regional methodology are juxtaposed with those obtained through the local method to assess the efficacy of the MIF technique. The model performed well for Arangali, Kalampur, Pattazhy, Pudur, and Mankara stations, as the quantile curves generated by the regional and local approaches matched well at these watersheds. In contrast, the regional and local quantile curves differ considerably at Perumannu, Ramamangalam, Kidangoor, and Erinjipuzha watersheds, indicating the effect of small sample size, higher sensitivity to local factors, modeling approach, and uncertainty involved. This investigation significantly enhances flood risk assessment in river areas using the MIF method to generate regional quantile curves, identify homogeneous regions, and compare regional and local quantile estimates, improving predictive accuracy at ungauged watersheds. The study confirmed data homogeneity across nine Kerala watersheds, with multivariate discordancy measures ?Di?<2.6, and a homogeneity test H value of -0.76. The BB8 copula best modeled the joint distribution of mean flood volume (V) and peak flow (Q), achieving a Kendall’s tau of 0.711 at Arangali. Regional quantile curves aligned well with standardized data, with the Gaussian copula (?)=0.4427, p<(1.75E-27) selected for multivariate regional analysis. © The Author(s) under exclusive licence to Institute of Geophysics, Polish Academy of Sciences 2025.

Faculty Publications

Browse

Filters

Settings

Sort By

Results per page

Search Results