BITS Faculty Publications

Permanent URI for this communityhttp://localhost:4000/handle/123456789/1867

Browse

Subject: search.filters.subject.Civil Engineering

Search Results

Now showing 1 - 10 of 856
  • No Thumbnail Available
    Item
    Deep Learning Approach for SDN-Enabled Intrusion Detection System in IoT Networks
    (MDPI, 2023-01) Dua, Amit
    Owing to the prevalence of the Internet of things (IoT) devices connected to the Internet, the number of IoT-based attacks has been growing yearly. The existing solutions may not effectively mitigate IoT attacks. In particular, the advanced network-based attack detection solutions using traditional Intrusion detection systems are challenging when the network environment supports traditional as well as IoT protocols and uses a centralized network architecture such as a software defined network (SDN). In this paper, we propose a long short-term memory (LSTM) based approach to detect network attacks using SDN supported intrusion detection system in IoT networks. We present an extensive performance evaluation of the machine learning (ML) and deep learning (DL) model in two SDNIoT-focused datasets. We also propose an LSTM-based architecture for the effective multiclass classification of network attacks in IoT networks. Our evaluation of the proposed model shows that our model effectively identifies the attacks and classifies the attack types with an accuracy of 0.971. In addition, various visualization methods are shown to understand the dataset’s characteristics and visualize the embedding features.
  • No Thumbnail Available
    Item
    Landfill leachate-induced ultraviolet quenching substances
    (IWA, 2023-09) Mandal, Pubali
    Landfill leachate is a complex wastewater with a wide range of pollutants and requires proper treatment before discharge. Landfill leachate is either treated on-site by biological and membrane processes or treated transported to nearby wastewater treatment plant for co-treatment with municipal wastewater. Recalcitrant organics, especially for stabilized leachate will not be removed or degraded by conventional biological processes. Some of these pollutants may absorb ultraviolet (UV) lights and decrease the UV transmittance. The UV quenching substances (UVQS) can be broadly classified as hydrophobic substances (humic acid + fulvic acid) and hydrophilic substances. The UVQS may interfere with the UV disinfection process and make it less effective. It may also protect any co-pollutant from being degraded by UV. Therefore, understanding of the treatment methods capable of removing UVQS is necessary. The aim of this chapter is to present overview of different treatment technologies available to remove/degrade UVQS. The composition of solid waste responsible for the formation of UVQS, characteristics, chemical composition, distribution and problems of UVQS has also been discussed.
  • No Thumbnail Available
    Item
    Application of nanomaterials synthesized using agriculture waste for wastewater treatment
    (Elsevier, 2024) Mandal, Pubali
    Global water security is a pressing issue confronting the water sector. The high-water usage, discharge of untreated wastewater, and different anthropogenic pursuit pose severe threats to water quality. Wastewater treatment is inevitable to fight freshwater scarcity and to protect human health, aquatic fauna and flora, etc. High reactivity, surface-to-volume ratio, and versatility in material development (nanosorbents, nanocatalysts, and nanodisinfectants) made a promising platform for nanomaterials in wastewater remediation. Currently, wastewater treatment using green-based materials and processes is obtaining immense attention. The usage of green materials will reduce resource consumption, cost, and chances of secondary pollutant generation. The aim of this chapter is to understand the status of the development of nanosorbents, nanocatalysts, and nanodisinfectants using agricultural waste. The chapter highlights current trends in applying green nanomaterials modified using agriculture waste to treat wastewater. Agricultural wastes, which are used for nanosorbent, nanocatalyst, and nanodisinfectant synthesis, are documented. The applications of prepared nanomaterials in removing several recalcitrant organic contaminants such as dyes, phenolic compounds, antibiotics, and pathogenic bacteria are discussed. The discussion also includes heavy metals removal as well as disinfection using agro-waste-based nanomaterials. The mechanism of pollutant removal is described. The chapter aims to improve the understanding of agricultural waste that can be used in the green synthesis of nanomaterials. The applicability of all these nanomaterials for specific pollutant removal will help in selecting industries for large-scale implementations. The comparative assessment of pollutant removal efficacies is expected to help the researchers in selecting alternative agro-waste to prepare nanomaterials exhibiting better performance.
  • No Thumbnail Available
    Item
    Occurrence and detection of pharmaceuticals in wastewater and its subsequent treatment using constructed wetlands, bioelectrochemical systems and their combination
    (IWA, 2024-04) Mandal, Pubali
    Pharmaceutically active compounds (PhAC) are pervasive in aqueous environments, and their presence poses an ever-increasing threat to aquatic creatures and all associated living forms. Most PhACs are extremely hydrophilic and have a complicated molecular structure, preventing them from being destroyed by traditional wastewater treatment methods. In addition, these contaminants are present at such a low concentration that their detection poses a significant challenge. Researchers have utilized advanced oxidation processes to degrade these chemicals over time. However, most studies have been conducted on the lab scale and do not function well for real wastewater since many interfering substances are present. In addition, these techniques are expensive and result in the production of harmful byproducts. To combat the PhACs, it is vital to develop a sustainable economic strategy. This book chapter discusses the occurrence of PhACs in wastewater, their potential environmental impacts, and the necessary procedures for accurately quantifying these compounds. The book addresses the possibilities of biological systems, such as constructed wetlands (CW) and bioelectrochemical systems (BES), in the hunt for a sustainable method of eliminating PhACs. CWs have been selected because they are robust systems with several simultaneous removal mechanisms. BES have also demonstrated considerable potential for treating these substances in wastewater and producing bioelectricity. In addition, the chapter discusses an emerging technology, that is, hybrid CW–BES systems, which utilize the benefits of both CW and BES and may prove to be an efficient approach to treating wastewater, removing PhACs, and generating electricity simultaneously.
  • No Thumbnail Available
    Item
    Simultaneous ammonia and organics degradation from municipal landfill leachate by electrochemical oxidation
    (Taylor & Francis, 2024-03) Mandal, Pubali
    The two primary issues for wide implementation of the electrochemical oxidation of wastewater are the significant cost of electrode and high energy consumption. On the other side, conventional biological processes and membrane technology have several drawbacks for recalcitrant landfill leachate (LL) treatment. To address these issues, graphite/PbO2 anode was used to treat medium to mature age (biodegradability index, 5-day biochemical oxygen demand/chemical oxygen demand: 0.25) LL. To reduce the cost of the oxidation process and maximize the efficiency, operating conditions were optimized. The optimum parameter values were obtained as 24.7 mA cm−2, 180 ± 3 rpm, and 1.9 cm of current density, stirring rate, and electrode gap, respectively. Dissolved organic carbon (DOC), chemical oxygen demand (COD), and ammonia-N removal efficiencies of 55 ± 1.4%, 81 ± 1.9%, and 56 ± 3% were obtained after 8 h of degradation at optimum conditions. The decrease in aromatic substances and ultraviolet (UV) quenching materials were evaluated by UV-Visible spectroscopy and Specific UV absorbance. The conversion of aromatic compounds into simpler molecule compounds was also verified by Fourier-transform infrared spectroscopy analysis. The lab-scale anode synthesis cost was evaluated as 0.42 USD.
  • No Thumbnail Available
    Item
    A comprehensive review on the treatment of pesticide-contaminated wastewater with special emphasis on organophosphate pesticides using constructed wetlands
    (Elsevier, 2024-09) Mandal, Pubali
    Pesticides pose a significant threat to aquatic ecosystems due to their persistent nature and adverse effects on biota. The increased detection of pesticides in various water bodies has prompted research into their toxicological impacts and potential remediation strategies. However, addressing this issue requires the establishment of robust regulatory frameworks to determine safe thresholds for pesticide concentrations in water and the development of effective treatment methods. This assessment underscores the complex ecological risks associated with organophosphate pesticides (OPPs) and emphasizes the urgent need for strategic management and regulatory measures. This study presents a detailed examination of the global prevalence of OPPs and their potential adverse effects on aquatic and human life. A comprehensive risk assessment identifies azinphos-methyl, chlorpyrifos, and profenfos as posing considerable ecological hazard to fathead minnow, daphnia magna, and T. pyriformis. Additionally, this review explores the potential efficacy of constructed wetlands (CWs) as a sustainable approach for mitigating wastewater contamination by diverse pesticide compounds. Furthermore, the review assess the effectiveness of CWs for treating wastewater contaminated with pesticides by critically analyzing the removal mechanism and key factors. The study suggests that the optimal pH range for CWs is 6–8, with higher temperatures promoting microbial breakdown and lower temperatures enhancing pollutant removal through adsorption and sedimentation. The importance of wetland vegetation in promoting sorption, absorption, and degradation processes is emphasized. The study emphasizes the importance of hydraulic retention time (HRT) in designing, operating, and maintaining CWs for pesticide-contaminated water treatment. The removal efficiency of CWs ranges from 38% to 100%, depending on factors like pesticide type, substrate materials, reactor setup, and operating conditions.
  • No Thumbnail Available
    Item
    Simulation of Cyclic Mean Stress Relaxation and Ratcheting for Aluminium 7050 Alloy
    (Springer, 2022-02) Barai, Sudhir Kumar
    The study attempts to simulate the cyclic-plastic behaviour of aluminium 7050 alloy under uniaxial asymmetrical strain- and stress-controlled fatigue loading which is primarily characterized by the two phenomena: (a) cyclic mean stress relaxation and (b) ratcheting. The suggested approach considers the Chaboche combined hardening model; the parameters of the Chaboche model are estimated using genetic algorithm optimization technique. The proposed methodology provides a single set of hardening parameters, which are used to simulate the cyclic-plastic response under both strain- and stress-controlled cyclic loading. Reported experimental results on aluminium 7050 alloy are used to demonstrate the potential of the proposed methodology; the accuracy of the suggested methodology is compared with some reported simulations for the material in the existing literature.
  • No Thumbnail Available
    Item
    Temperature, porosity and strength relationship for fire affected concrete
    (Springer, 2022-02) Barai, Sudhir Kumar
    In a fire incident, structural members are mostly unevenly exposed to temperatures and consequently suffer uneven damage. To rehabilitate and restore these for future usage, it is essential to correctly map the temperature field that the structural elements were subjected to during fire events. The majority of the existing relationships for temperature prediction apply to reinforced concrete beams only. In the present study, a material-porosity-based approach is proposed. Normal and high strength concrete structural elements were exposed to a range of elevated temperatures, and reserved compressive strength was evaluated. Another set of the same specimens were used to determine porosity using four techniques. Based on the observations, correlations among temperature, strength, and porosity for normal and high strength concrete are proposed. The suggested methodology and expressions may be used to predict the reserved strength and temperature field that the structural elements may have been exposed to, based on the evaluated porosity of concrete. Back-scattered electron Imaging was found to be the most fitting method for porosity evaluation.
  • No Thumbnail Available
    Item
    Biocement treatment for upcycling construction and demolition wastes as concrete aggregates
    (Springer, 2022-06) Barai, Sudhir Kumar
    Reutilisation of the construction and demolition (C&D) wastes as aggregate in concrete is a vital step towards sustainability as it prevents depletion of natural resources as well as alleviates wastes. However, the attached mortar on the aggregate surface renders certain shortcomings like excessive water absorption, high porosity, and weak interfaces. Recycled aggregates can be treated to improve these shortcomings. However, the minimisation of the drawbacks involves huge energy, materials, and cost. Moreover, the efficacy of such adopted method is sometime questionable, and which needs further research. This study demonstrates bio-treatment of recycled coarse aggregate (RCA) as a means of upcycling and compares it with conventional cement slurry treatment. A novel spraying technique has been applied that significantly economises biocement treatment. The experimental results show that biocement treatment reduced the water absorption by 70%. The treatment has filled the pores of RCA and has prevented water absorption. In contrast, cement slurry coating treatment shows increase in water absorption of RCA by 19%. The compressive strength of concrete with 100% biocement treated RCA surpasses that of concrete with natural coarse aggregates. The genesis of this dramatic improvement in case of biocement has been established through micro-scale studies including scanning electron microscopy and energy-dispersive X-ray spectroscopy. The cost analysis demonstrates that RCA upcycled with biocement treatment is more economical than natural aggregates or cement treated ones. Findings of the present study led to the conclusion that 100% replacement of natural coarse aggregates can be achieved by upcycling C&D wastes as coarse aggregate through bio-treatment.
  • No Thumbnail Available
    Item
    Performance assessment and life cycle analysis of concrete containing ferrochrome slag and fly ash as replacement materials – A circular approach
    (Elsevier, 2022-09) Barai, Sudhir Kumar
    Climate change mitigation and resource efficiency have emerged as crucial challenges for long-term sustainability of concrete. Implementing circular approach through waste valorisation in concrete production with eco-efficient mix design is an efficient mitigation pathway to combat natural resources depletion and environmental issues. This paper investigates techno-environmental sustainability of concrete utilizing 100% ferrochrome slag as alternate coarse aggregate and fly ash as partial cement substitute (0–40%) adopting particle packing optimization technique (PPOT) as a sustainable mix design method. Total of ten types of concrete mixtures were prepared using the alternate materials and mix design methods (PPOT and IS:10262(2009)). Natural aggregate concrete prepared by IS:10262(2009) mix design was considered as the reference mixture. Technical assessment of concrete was performed experimentally in terms of compressive strength and tensile strength. Environmental performance was investigated through life cycle assessment (LCA) as per ISO 14040-44 guidelines using cradle-to-gate system boundary and two functional units: 1 m3 concrete and 1 MPa compressive strength. Results revealed that ferrochrome slag aggregate concrete (FCSAC) containing fly ash up to 30% prepared by PPOT has enhanced strength than reference concrete. Regardless of the functional units used, FCSAC with 30% fly ash designed by PPOT was ranked as the most sustainable mix with significant environmental savings (around 50–70%) without compromising desired requirements. Sensitivity analysis was performed by varying transportation distance, mode of transport and energy mix. Results showed that FCSAC with 30% fly ash is not sensitive to the scenarios investigated. The outcomes will be helpful for decision-makers to develop policy directives and frameworks on synergistic use of ferrochrome slag and fly ash towards concrete sustainability.