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Dataset of polarimetric images of mechanically generated water surface waves coupled with surface elevation records by wave gauges linear array.

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arXiv

arXiv 2024年

作者： Ginio, Noam Lindenbaum, Michael Fishbain, Barak Liberzon, Dan Faculty of Civil and Environmental Engineering Technion Haifa320003 Israel Faculty of Computer Science Technion Haifa320003 Israel Interdisciplinary Program for Marine Engineering Technion Haifa320003 Israel

Effective spatio-temporal measurements of water surface elevation (water waves) in laboratory experiments are essential for scientific and engineering research. Existing techniques are often cumbersome, computationally heavy and generally suffer from limited wavenumber/frequency response. To address these challenges a novel method was developed, using polarization filter equipped camera as the main sensor and Machine Learning (ML) algorithms for data processing [1,2]. The developed method training and evaluation was based on in-house made supervised dataset. Here we present this supervised dataset of polarimetric images of the water surface coupled with the water surface elevation measurements made by a linear array of resistance-type wave gauges (WG). The water waves were mechanically generated in a laboratory waves basin, and the polarimetric images were captured under an artificial light source. Meticulous camera and WGs calibration and instruments synchronization supported high spatio-temporal resolution. The data set covers several wavefield conditions, from simple monochromatic wave trains of various steepness, to irregular wavefield of JONSWAP prescribed spectral shape and several wave breaking scenarios. The dataset contains measurements repeated in several camera positions relative to the wave field propagation direction. © 2024, CC BY-NC-ND.

关键词： Water waves

Increasing risk of oppressive heatwaves over India in the future warming

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arXiv

arXiv 2025年

作者： Sudharsan, Naveen Singh, Jitendra Ghosh, Subimal Karmakar, Subhankar Environmental Science and Engineering Department Indian Institute of Technology Maharashtra Bombay India Department of Environmental Systems Science ETH Zürich Zürich Switzerland Department of Civil Engineering Indian Institute of Technology Maharashtra Bombay India Interdisciplinary Program in Climate Studies Indian Institute of Technology Maharashtra Bombay India Centre for Urban Science & Engineering Indian Institute of Technology Maharashtra Bombay India

The frequency of heatwave events has been increasing with climate change across the globe, causing devastating impacts on human and natural systems. Particularly, the co-occurrence of high temperature with high humidity has the potential of worse impacts on human health than extreme temperature alone. We use observations to examine the characteristics of extreme (high temperature and low humidity) and oppressive (high temperature and high humidity) heatwaves and their impacts on human mortality. We also use climate model simulations to understand the likelihood of heatwaves under varied warming conditions in future climates. We find an increasing trend in the number of days of extreme and oppressive heatwaves, with surprisingly a higher rate of increase in oppressive heatwaves. We also observe a higher correlation between oppressive heatwaves and historical heat-stress-related human deaths than extreme heatwaves, indicating more substantial impacts of oppressive heatwaves on the human population than extreme heatwaves. Further, our results show a five-fold increase in the number of days of oppressive heatwaves under 1.5°warming in both mid (2035-2065) and end (2070- 2100) of the 21st century, relative to the historical period (1975 to 2005) whereas the number of extreme heatwave days remains relatively constant in mid and end of this century. Remarkably, 2°warming results in an eight-fold and almost two-fold increase in the number of days of oppressive heatwaves by the end of the century relative to the historical period and 1.5°warming conditions. These results suggest that limiting the mean global warming to 1.5°can reduce the likelihood of oppressive and extreme heatwaves by 44% and 25% by the end of the century relative to the 2°warming world. Moreover, the remarkable increase in oppressive heatwave days highlights the elevated risk of heatwaves over densely populated countries and indicates an imminent need for adaptation measures. © 2025, CC BY.

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Key fuel characteristics and techno-economic aspects of torrefied rubberwood biomass pellets produced by incorporating various cassava-based binders at varied doses

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environmental science and Pollution Research 2024年第25期31卷 37663-37680页

作者： Kongto, Pumin Palamanit, Arkom Chaiprapat, Sumate Tippayawong, Nakorn Khempila, Jarunee Ruangim, Panatda Energy Technology Program Department of Interdisciplinary Engineering Faculty of Engineering Prince of Songkla University 15 Kanjanavanich Rd. Songkhla Hat Yai90110 Thailand Research Center Faculty of Engineering Prince of Songkla University 15 Kanjanavanich Rd. Songkhla Hat Yai90110 Thailand Department of Civil and Environmental Engineering Faculty of Engineering Prince of Songkla University 15 Kanjanavanich Rd. Songkhla Hat Yai90110 Thailand Department of Mechanical Engineering Chiang Mai University 239 Huay Kaew Rd. Chiang Mai Muang District 50200 Thailand Physics Program Faculty of Science and Technology Rajabhat Maha Sarakham University 80 Nakhon Sawan Rd. Maha Sarakham Mueang District 44000 Thailand

Improving energy content and hydrophobic nature of woody biomass can be pursued through torrefaction. This gives torrefied biomass with a low bulk density, potentially increasing storage and transport costs. To overcome this issue, densifying the torrefied biomass is necessary. However, poor binding of particles makes densification challenging without using a binder. Therefore, the aim of this study was to investigate the physicochemical characteristics and techno-economic aspects of torrefied rubberwood biomass (TRWB) when pelletized using various cassava-based binders at different blending ratios. The selected binders included cassava starch (CS), cassava pulp (CP), and cassava chip (CC). Each binder at 5%, 10%, or 15% (wt.) was mixed with TRWB and water before pelletizing using a flat die machine. The results revealed that pelletizing TRWB with different cassava-based binders at various blending ratios influenced the physicochemical characteristics of the TRWB pellets, particularly dimensions, bulk density, fuel and atomic ratios, and energy content. The TRWB pellets demonstrated energy densities in the range of 7.95–11.39 GJ/m3, and their mechanical durability and fine content fell within acceptable ranges. The TRWB pellets maintained their shape during 120 min of water soaking, with water absorption levels varying by binder dose. The pelletizing ability, material, and energy costs of TRWB pellets depend on binder type and dose. CP can be applied as a binder for pelletizing torrefied rubberwood biomass. However, the mechanical durability of the product needs to be above the user requirement or standard. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.

关键词： Pelletizing

Flood Modelling for an Urban Indian Catchment: Challenges and Way Forward

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Flood Modelling for an Urban Indian Catchment: Challenges an...

Virtual Conference on Disaster Risk Reduction, VCDRR 2021

作者： Ghosh, Mousumi Karmakar, Subhankar Ghosh, Subimal Interdisciplinary Program in Climate Studies Indian Institute of Technology Bombay Mumbai400076 India Environmental Science and Engineering Department Indian Institute of Technology Bombay Mumbai400076 India Centre for Urban Science and Engineering Indian Institute of Technology Bombay Mumbai400076 India Department of Civil Engineering Indian Institute of Technology Bombay Mumbai400076 India

ISBN: (纸本)9789811655005

The current study aims to develop a holistic hydrodynamic flood modelling framework for the Mithi catchment of Mumbai city, India, which is subjected to flooding almost every year causing huge losses and inconvenience. A one-dimensional flood model (MIKE 11) which accounts for the river discharge along with stormwater drainage discharge is coupled with a two-dimensional flood model (MIKE 21) which simulates the overland flow in the MIKE FLOOD platform along with the major flood influencers such as rainfall and tidal elevation to develop a three-way coupled flood modelling framework. The flood parameters obtained from this framework are translated into flood inundation maps which account for flood depth and flood hazard maps which account for flood depth along with spatial velocity and can help to identify the potential areas at risk. However, hydrodynamic flood modelling is highly data-intensive and requires good resolution meteorological, hydraulic, and topographical data sets. Therefore, the unavailability of long-term and reliable data sets in developing and underdeveloping countries cause a major hindrance for modelling in such catchments. The current study also adapts alternate robust methods to address the challenge of data scarcity of rainfall, discharge, tidal elevation, and drainage network. The proposed framework and methods are generic and can be incorporated in similar data-scarce urban catchments for effective flood management. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Hydrodynamics

The Impact of Early Life Exposure to Individual and Combined Pfas on Learning, Memory, and Bioaccumulation in C. Elegans

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SSRN 2024年

作者： Currie, Seth D. Ji, Yuqing Huang, Qingguo Wang, Jia-Sheng Tang, Lili Interdisciplinary Toxicology Program University of Georgia AthensGA30602 United States Department of Environmental Health Science College of Public Health University of Georgia AthensGA30602 United States Department of Crop & Soil Sciences College of Agricultural and Environmental Sciences University of Georgia GriffinGA30223 United States

Per- and Polyfluoroalkyl Substances (PFAS) are a group of water-soluble chemicals used for decades with important industrial and commercial applications. Due to their chemical and thermal stability, persistence in the environment, and widespread human exposure, PFAS become an important concern for public health. In this study, eleven highly prevalent PFAS and a reference mixture were selected according to various drinking water sources. The nematode, Caenorhabditis elegans, were exposed to PFAS at 0.1, 1, 10, 100, and 200µM, and the toxic effects on learning & memory along with the bioaccumulation were investigated using a high-throughput screening (HTS) platform. Our results showed that perfluorooctanesulfonic acid (PFOS) and perfluorobutanesulfonic acid (PFBS) exhibited significant inhibitory effects (p © 2024, The Authors. All rights reserved.

关键词： Bioaccumulation

Design, Development and Performance Evaluation of a Miniature Electrostatic Precipitator in an Indoor Environment

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SSRN 2024年

作者： Kumar, Aiswarya Nawale, Prashant Rohidas Sahu, Manoranjan Aerosol and Nanoparticle Technology Laboratory Environmental Science and Engineering Department Indian Institute of Technology Bombay Mumbai400076 India Interdisciplinary Program in Climate Studies Indian Institute of Technology Bombay Mumbai400076 India Centre for Machine Intelligence and Data Science Indian Institute of Technology Bombay Mumbai400076 India

Different PM capture technologies are available in market as well as on lab scale, they pose several drawbacks. Therefore, a miniature ESP was designed in laboratory and operated at optimal operating conditions to obtain maximised capture of PM. Results from study confirmed that designed ESP was capable of capturing various standard aerosol, major indoor sources and infiltrated PM with a total removal efficiency of 97.87% to 99.97% in PM sizes from 10 nm to 800 nm. Additionally, energy consumed/clean air delivery rate and emission of by-products were found to be comparatively lesser compared to commercial purifiers. © 2024, The Authors. All rights reserved.

关键词： Electrostatic precipitators

Long-Term Performance of Sulfidated Nanoscale Iron for Hexavalent Chromium Removal from Groundwater in Sequential Batch Study

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SSRN 2023年

作者： Bhattacharya, Mainak Barbhuiya, Najmul Haque Singh, Swatantra Pratap Environmental Science and Engineering Department Indian Institute of Technology Bombay Mumbai India Interdisciplinary Program in Climate Studies Indian Institute of Technology Bombay Mumbai400076 India Centre for Research in Nanotechnology & Science Indian Institute of Technology Bombay Mumbai400076 India

Chromium [Cr] contamination in groundwater is one of the serious environmental concerns due to the carcinogenicity of its water-soluble and mobile hexavalent [Cr(VI)] form. In spite of the existence of multiple precipitation and adsorption-based Cr(VI) remediation technologies, the usage of sulfidated nano zerovalent iron (S-nZVI) has recently attracted researchers due to its high selectivity. Although S-nZVI has been proven to be effective towards Cr(VI) immobilization, its long-term performance in groundwater matrix has not been explored. In this contribution, a comparative study between conventional nano zerovalent iron (nZVI) and S-nZVI was conducted to investigate their respective efficiencies due to repeated usage. First, influences of S-nZVI dosage, initial concentration of Cr(VI), pH, ionic strength, total hardness, sulfate, carbonate, and silicate were probed in ultrapure water. Further experiments were performed in synthetic groundwater to investigate the effects of the initial concentration of Cr(VI) in the pH range of 4 – 8 for 1 g L-1 S-nZVI dosage. The removal rate of Cr(VI) was quantified in groundwater without pH fixation, following the second-order reaction kinetics. Finally, a set of sequential batch studies was performed to compare the performance of nZVI and S-nZVI due to repeated usage in Cr(VI)-spiked ultrapure water and groundwater matrices. Mechanistic interpretation of the processes governing the immobilization of Cr(VI) was done by integrating the results of these experiments with the metadata. While aggregation due to magnetic properties and rapid oxidation of Fe decreased the efficiency of nZVI with repeated usage, sulfidation minimized the passivation and favored an extended reducing environment because of continuous electron transfer from Fe and S. © 2023, The Authors. All rights reserved.

关键词： Groundwater

Performance Evaluation of Sulfidated Nanoscale Iron for Hexavalent Chromium Removal from Groundwater in Sequential Batch Study

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SSRN 2023年

Chromium [Cr] contamination in groundwater is one of the serious environmental concerns due to the carcinogenicity of its water-soluble and mobile hexavalent [Cr(VI)] form. In spite of the existence of multiple precipitation and adsorption-based Cr(VI) remediation technologies, the usage of sulfidated nano zerovalent iron (S-nZVI) has recently attracted researchers due to its high selectivity. Although S-nZVI effectively immobilized Cr(VI), its long-term performance in multiple shifted equilibrium has not been explored. In this contribution, a comparative study between conventional nano zerovalent iron (nZVI) and S-nZVI was conducted to investigate their respective efficiencies during repeated usage. First, influences of S-nZVI dosage, initial concentration of Cr(VI), pH, ionic strength, total hardness, sulfate, carbonate, and silicate were probed in ultrapure water. Further experiments were performed in synthetic groundwater to investigate the effects of the initial concentration of Cr(VI) in the pH range of 4 – 8 for 1 g L-1 S-nZVI dosage. The removal rate of Cr(VI) was quantified in groundwater without pH fixation. Finally, a set of sequential batch studies was performed to compare the performance of nZVI and S-nZVI due to repeated usage in Cr(VI)-spiked ultrapure water and groundwater matrices. Mechanistic interpretation of the processes governing the immobilization of Cr(VI) was done by integrating the results of these experiments with the metadata. While aggregation due to magnetic properties and rapid oxidation of Fe decreased the efficiency of nZVI with repeated usage, sulfidation minimized the passivation and favored an extended reducing environment because of continuous electron transfer from iron and sulfur components. © 2023, The Authors. All rights reserved.

关键词： Groundwater

Hexavalent Chromium Remediation Using Single-Step Synthesized Sulfidated Nanoscale Iron Particles Modified Kaolin

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SSRN 2023年

The occurrence of dissolved hexavalent chromium [Cr(VI)] in freshwater systems is a serious environmental hazard because of its high toxicity. Although different types of nZVI effectively removed Cr(VI), performance evaluation of nZVI modified with a suitable clay adsorbent—kaolinite—was not thoroughly studied. In the present research, kaolin was modified with nZVI (K-nZVI) and SnZVI (K-SnZVI) at two different kaolin to iron mass ratios (kaolin: Fe) to remove Cr(VI) under varying geochemical conditions. Both K-nZVI and K-SnZVI were synthesized by a simple one step process, avoiding complicated synthesis protocols of modified nZVI mostly reported in the literature. Usage of Fe in the nanoparticles was minimized by increasing the kaolin: Fe ratio, and effects of ionic strength of the background solution, pH, major cations, and anions in Cr(VI) remediation efficiencies were probed. Kinetics of Cr(VI) removal by K-nZVI and K-SnZVI were quantified from sacrificial batch studies. The uptake of Cr(VI) by K-nZVI and K-SnZVI was fitted to the Freundlich isotherm model. With maximum Cr(VI) remediation efficiencies of 100% and 98% in synthetic groundwater contaminated with 2 - 100 mg L-1 Cr(VI). Using kaolin, an analog of the naturally available kaolinite clay, with relatively decreased Fe content in the nanoparticles, would also aid in reducing the treatment cost. © 2023, The Authors. All rights reserved.

关键词： Groundwater