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Based on a systematic review of convolutional neural networks (CNN), this study explores the efficacy of small imaging sensors in monitoring the real-time presence of cyanotoxins and hazardous contaminants in urban ecosystems. To develop a machine learning-based CNN, this study first investigated the relationships between the prevalence of hazardous algal blooms (HABs) and faecal indicator bacteria (FIB) in waterways and aquifers of certain semi-arid zones of Sri Lanka, Sweden and New York (United States). By incorporating a popularly known AbspectroscoPY framework to effectively process the spectrophotometric data of the obtained samples, the formulation subsequently reveals strong positive correlations between FIB coliforms and nutrient loads (particularly nitrate and phosphate). A corroborative association with the incidence of chronic kidney disease of uncertain aetiology (CKDu) among the residents of the studied regions further affirms the reliability of the methodology. These findings underline the need for policymakers to consider the geographical and land-use traits of urban habitats in strategies aimed at reducing water-borne health hazards. [ABSTRACT FROM AUTHOR]

The spread of infectious diseases such as COVID-19 depends on complex fluid dynamics interactions between pathogens and fluid phases, including individual droplets and multiphase clouds. Understanding these interactions is crucial for predicting and controlling disease spread. This applies to human and animal exhalations, such as coughs and sneezes, as well as bursting bubbles that create micron-sized droplets in various indoor and outdoor environments. By exploring case studies in this regard, this study examines the emerging field of fluid dynamics in disease transmission, focusing on multiphase flows, interfacial flows, turbulence, pathogens, human traffic, aerosol transmission, ventilation, and breathing microenvironments. These results indicate that increased ventilation rates and local ventilation methods can effectively reduce the concentration of SARS-CoV-2-laden aerosols in the immediate breathing spaces between individuals. In a displacement-ventilated room, both neutral and unstable conditions were more effective in removing breathed SARS-CoV-2-laden aerosols from the air, regardless of the presence of test subjects. However, stable conditions may increase the risk of infection in individuals living in confined spaces. Thus, the findings of this study are useful for providing practical guidance for managing the spread of airborne infections. [ABSTRACT FROM AUTHOR]

Arsenic pollution of groundwater is a serious concern in the developing world. Over the last decade, significant progress has been made in arsenic remediation in India, where millions of households are exposed to arsenic poisoning through drinking water drawn from contaminated aquifers. Arsenic-treatment units (ATUs) have been effective in helping regions where piped-water supply of surface water is unachievable due to logistic constraints. However, no policy measure exists on environmental and economic management of the voluminous wastewater produced by ATUs. The waste is highly toxic in terms of its arsenic content and leachability and therefore can readily re-contaminate local environments if suitable stabilisation methods are not implemented. This paper presents an investigation of the recent developments in arsenic-wastewater-management practices of a severely affected state called West Bengal. Commercial fixation of the waste by incorporation into building materials is often seen as a potent method for ultimate encapsulation of arsenic toxicity. By analysing the practical efficacy of such a prospective project, the author has made an attempt to model scenarios involving non-hazardous and financially beneficial arsenic waste management for sustainable arsenic mitigation in the region. [ABSTRACT FROM AUTHOR]

Organosilane-based thin coating on top of galvannealed (GA) coating, known as secondary coating, provides extra protection from corrosion and thus is used for manufacturing automotive fuel tanks. In the present investigation, resistance seam weldability of 0.8-mm-thick secondary-coated GA interstitial free steel has been evaluated and compared with conventional GA sheets of identical thickness, chemistry, and mechanical properties. It has been found that the 1-3-µm-thick layer of organosilane-based secondary coating increases the electrical contact resistance by up to 50%. Consequently, the heat input increases by 34% when welding secondary coated steel as compared to conventional GA steel. This higher heat-input ensures suitable nugget formation over a wide range of parameters viz. a wider weldability lobe. This paper also addresses the test results on the service life of the welding electrodes. It has been found that the electrodes can withstand up to 30 m of continuous welding of secondary-coated steel without affecting the weld quality in terms of the joint strength. However, for conventional GA sheets, the same electrodes lay up to 20 m of welding length prior to dressing. Higher electrode face widening takes place during welding of plain GA sheets which lowers the current density and thereby affects formation of high-quality weld nugget. [ABSTRACT FROM AUTHOR]

Electrical resistivity of commercially produced plain carbon manganese steel has been experimentally measured at room temperature (28–30°C) using four-probe method. Resulting data were used to generate both regression based and artificial neural network-based models for prediction of electrical resistivity from the chemical composition of steel. It was found that both models were capable of predicting the resistivity within ±5% error band. Analysis of data also indicated carbon to be the most influential element to increase resistivity followed by manganese and silicon. A comprehensive literature review indicates no such advanced resistivity prediction model is available in the public literature for commercially produced steel with wide variation in carbon content (0.03 0.85 wt-%), manganese content (0.35–1.50 wt-%) and silicon content (0.015–0.90 wt-%). [ABSTRACT FROM AUTHOR]

The Covid-19 pandemic has devastated the world of work, particularly labour. Worldwide economic crises and unemployment present a difficult road ahead in ensuring the sound health and productivity of labour. Among developing countries, India has been at the centre stage of this catastrophe, with millions of labourers suddenly losing their jobs and in desperate need of livelihoods to survive. Emergency policy measures undertaken to sustain industrial growth in the crises may not be comforting to the labour in India in the long run. This paper is intended to help policymakers and the civil engineering community in meeting the urgency of resolving the adverse impacts of the Covid-19 crisis. [ABSTRACT FROM AUTHOR]

It was attempted to produce galvannealed dual-phase (DP) steel through a commercial continuous galvanizing line (CGL). The main challenge was to form the DP microstructure even with the slow cooling rate after annealing in the CGL. A two-pronged approach was adopted for this, viz. design of the steel chemistry with calculations and optimization of the CGL parameters with simulation using Gleeble-3800 thermomechanical simulator. The steel thus produced in CGL revealed ferrite and 18 ± 2% martensite microstructure, with tensile strength exceeding 600 MPa and 24% total elongation along with good formability. Weldability study using resistance spot welding indicated the possibility of achieving sound joint with a 4-kA width in weld time-current lobe despite the high carbon equivalence. [ABSTRACT FROM AUTHOR]

In the current work, the influence of boron on austenite to ferrite transformation behavior under continuous cooling condition and its associated features, e.g., final microstructure, mechanical properties, etc., in low carbon steel has been studied. The steels (C 0.04 wt.%, B 10-100 ppm) prepared in an open air laboratory furnace showed identical microstructures having ferrite grains of 20-25 µm. However, tensile test data indicate variation of yield strength and ultimate tensile strength with boron content. The yield point elongation and strain aging index both were found to decrease with increase in boron content or boron-to-nitrogen ratio. As the boron nitride precipitates stimulate the nucleation of ferrite phase, the dilation curves show an increase in austenite to ferrite transformation start temperature with boron content. The resulting microstructure and hardness value also corroborate the finding. Transmission electron microscopy findings revealed the presence of ultra-fine boron nitride (BN) precipitates in both grain boundary and grain body of the steel having boron concentration of 30 ppm and beyond. The presence of these precipitates also increased with boron content. Based on austenite decomposition behavior, related microstructure and hardness values it is conjectured that these BN precipitates may act as nucleating agent for polygonal ferrite during austenite decomposition, thereby softening the steel during fast cooling. [ABSTRACT FROM AUTHOR]

Conventional testing of fracture toughness measurement for thin metallic sheets is not possible owing to the large plastic zone ahead of the crack tip. Hence, the critical-crack tip opening angle $$(\hbox {CTOA}_\mathrm{c})$$ has been considered to be the key parameter to evaluate resistance of a thin sheet against stable crack propagation. In the present work, attempt has been made to measure the $$\hbox {CTOA}_\mathrm{c}$$ of interstitial free high strength steel (IFHS) with 1 mm thickness using compact tension C(T) specimen. A high speed camera has been used for monitoring and imaging the progress of the crack length and crack tip angle during loading. The CTOA $$_\mathrm{c}$$ measured from these photographs found to be $$12^{\circ }\,\pm \,1.5^{\circ }$$ . In these experiments, the crack tip velocity was also varied from 1.9 to 960 mm/min and no changes in the $$\hbox {CTOA}_\mathrm{c}$$ value were observed. The high ductility of IFHS steel along with prevailing plane stress condition might be the reason of appreciably large $$\hbox {CTOA}_\mathrm{c}$$ value. [ABSTRACT FROM AUTHOR]