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Challenges with bioaugmentation and field-scale application of bioremediation processes for petroleum-contaminated sites: a review
Get PDFBioremediation is a promising method for cleaning up sites contaminated with petroleum hydrocarbons (PHs), with bioaugmentation being a common strategy that involves the use of microbial consortia to treat these sites. However, using a single bacterium is not effective in treating PHC contamination due to the range of compounds present. The use of different strains as a consortium can improve treatment, but bioaugmentation often fails due to various factors, especially in large-scale applications. The number and survival of introduced microorganisms are critical during bioremediation, and immobilization by using carrier materials such as biochar can protect added microorganisms from adverse impacts. Advanced composting methods can also be effective in treating petroleum-polluted sites in commercial-scale applications. By adjusting environmental factors and adding compost, native microorganisms can be biostimulated. This review aims to critically analyze the challenges associated with bioaugmentation and field-scale applications of bioremediation for petroleum-contaminated sites, specifically identifying key variables that impact the success of bioremediation efforts and evaluating the effectiveness of different bioremediation strategies in field conditions. The review addresses the primary factors contributing to the failure of bioaugmentation in large-scale applications, how the survival and activity of introduced microbial consortia can be enhanced in contaminated environments, and the most effective strategies for field-scale bioremediation of petroleum-contaminated sites. The strategies discussed are evaluated based on their ability to enhance microbial survival, their practicality in large-scale applications, their environmental impact, and their overall effectiveness in reducing PHC levels. By providing a comprehensive analysis of these aspects, this review aims to offer insights into optimizing bioremediation processes for field-scale applications.Indian Journal of Microbiolog
Shock-induced fan cowl separation during aeroengine windmilling at diversion from cruise
Get PDFWhen a civil aircraft engine is operated at windmill during the cruise flight phase, there is supersonic flow acceleration around the leading edge of the fan cowl toward the external surface. The terminating normal shock wave can separate the turbulent boundary layer developing on this external surface. A series of experiments at a flight-relevant Reynolds number (1.2 million based on lip thickness) are performed in a quasi-two-dimensional wind tunnel rig to investigate the underlying flow physics. At a nominal inflow Mach number of 0.65 and a nacelle incidence angle of 4.5 deg, as the equivalent engine mass-flow rate is reduced, an increase in shock strength results in flow separation when the shock exceeds Mach 1.4. Over a 10% range in the notional engine mass-flow rate, the boundary layer developing on the external fan cowl thickens by a factor of three on the onset of separation. A reduction in the incoming Mach number from 0.65 to 0.60 weakens the shock wave and thus delays separation. An increase in surface roughness has no significant effect in situations where the boundary layer remains attached. However, for separated cases, an increased local roughness height causes a greater separation extent and a thicker boundary layer downstream of the shock wave.This project has received funding from the Clean Sky 2 Joint Undertaking (JU) under Grant Agreement No. 101007598. The JU receives support from the European Union’s Horizon 2020 research and innovation program and the Clean Sky 2 JU members other than the union.AIAA Journa
A new framework for river restoration planning at catchment scale in the UK
No full textSpecial Issue: River RestorationThe main aim of catchment planning is to prioritise measures that will reverse the decline of biological communities. In recent decades, there has been an increase in methods, tools and the availability of data to aid this process. However, how we use data to make decisions is the crucial and often neglected part of catchment planning, and there is sometimes a tendency to revert to reach‐scale opportunism rather than planning at the catchment scale. Planning approaches in the UK have ranged from public sector–led plans in the 1990s to the present‐day partnership approach led by the third sector (non‐governmental charitable or not‐for‐profit organisations). We have reviewed 237 catchment plans from the UK to understand the approaches that have been taken. Our findings indicate that many plans do not clearly link evidence and data to decision‐making; problems are poorly defined using broad terms such as ‘issues’ instead of characterising pressures and impacts; catchment objectives tend to be broad and not specific; measures are often prioritised based on opportunity; and it is not always clear how measures are expected to contribute to the achievement of catchment targets. Altogether, we noted the absence of agreed, standardised frameworks for producing plans, describing how data should be analysed, problems identified and actions prioritised. We propose a new catchment planning framework that encourages evidence‐based decisions through the assessment of pressures and impacts, and ultimately the prioritisation of river restoration options (encompassing rehabilitation, renaturalisation, enhancement, re‐creation and mitigation of the hydrology, water quality and geomorphology of the river, floodplain and wider catchment) based on their contribution to the alleviation of catchment‐scale impacts, and which can be applied by nonspecialists using citizen science data.River Research and Application
Impedimetric biosensors for the quantification of serum biomarkers for early detection of lung cancer
Get PDFData supporting this study are openly available from Cranfield University repository, CERES, at: https://dspace.lib.cranfield.ac.uk/handle/1826/19632, accessed on 16 November 2024.Lung cancer is the most common type of cancer diagnosed worldwide and is also among the most fatal. Early detection, before symptoms become evident, is fundamental for patients’ survival. Therefore, several lung cancer biomarkers have been proposed to enable a prompt diagnosis, including neuron-specific enolase (NSE) and carcinoembryonic antigen (CEA). NSE and CEA are two serum proteins whose elevated levels have been associated with lung cancer. Hence, in this study, impedimetric biosensors (immunosensors) able to quantify NSE and CEA were developed as proof-of-concept devices for lung cancer diagnosis. The sensing platform exploited for the immunosensors comprises a novel combination of a magnetic platform, screen-printed gold electrode (SPGE), and magnetic nanobeads (MB). The MB were functionalized with antibodies to capture the analyte from the sample and to move it over the sensing area. The immunosensors were then developed by immobilizing another set of antibodies for either CEA or NSE on the SPGE through formation of self-assembled monolayer (SAM). The second set of antibodies enabled a sandwich assay to be formed on the surface of the sensor, while MB manipulation was applied during the sensor performance to depict a microfluidic system and increase antigen–antibody complex formation prior to CEA or NSE detection and quantification. The optimized immunosensors were successfully tested to measure various concentrations of CEA and NSE (0–100 ng/mL) in both phosphate buffer and 100% human serum samples. Clinically relevant detection limits of 0.26 ng/mL and 0.18 ng/mL in buffer and 0.76 ng/mL and 0.52 ng/mL in 100% serum for CEA and NSE, respectively, were achieved via electrochemical impedance spectroscopy with the use of potassium ferri/ferrocyanide as a redox probe. Hence, the two immunosensors demonstrated great potential as tools to be implemented for the early detection of lung cancer.Biosensor
On the composition gradient of steel/Invar functionally graded material manufactured by wire-based direct energy deposition
Get PDFThis study utilized double-wire plasma arc direct energy deposition to produce functionally graded materials (FGMs) with two transition designs, abrupt (AT) and gradual (GT), from Er90s steel to Invar. The study systematically compared the transition in chemical composition, microstructure, phase evolution, thermal stress, and mechanical performance. Both FGM types exhibited a band structure in the Er90s section and coarse columnar grains in the Invar section, with the AT deposit showing a 1 mm thick, defect-free interface and the GT deposit having an 18 mm thick transition region with distinct boundaries. It revealed diverse microstructures across the transition zones, including fine ferrite, martensite with minor retained austenite (RA), coarse columnar austenite with martensite dendrites, and single FCC austenite. The GT sample uniquely featured a microstructure of martensite laths inside prior austenite decorated by RA semicontinuous network, with a crack detected due to dilatational stresses from martensite transformation. Hardness was similar in both FGM types, with higher values at the interfaces, especially in the GT FGM. The GT FGM demonstrated higher strength but lower ductility compared to the AT FGM, with failure occurring in the Invar portion for both. Thermal stress modelling indicated smoother stress transitions in the GT sample but no significant performance differences between Er90s and Invar. This study showcases the effectiveness of double-wire plasma arc DED in producing steel/Invar FGMs with varying composition gradients. It also underscores the importance of selecting the right mixing ratio for Er90s/Invar FGM deposits to avoid cracking and deterioration of properties in the gradient area.This work is financially supported by the “Enabling Multi-Functional Performance through Multi-Material Additive Manufacturing” project (No 862617 – MULTI-FUN) funded by European Union’s Horizon 2020 research and innovation programme.Additive Manufacturin
Membrane technology for water reuse in decentralised non-sewered sanitation systems: comparison of pressure driven (reverse osmosis) and thermally driven processes (membrane distillation and pervaporation)
Get PDFMembrane processes are an established barrier technology for water reclamation from wastewater. Applied at a household scale to improve sanitation practice, membrane technology can disrupt the source–receptor pathway, alleviate water scarcity through eliminating flush water and recover clean water for reuse. However, blackwater comprises a distinct composition compared to municipal wastewater, and there is only limited understanding on whether membrane selectivity is sufficient to produce water of sufficient quality for reuse. In this study, pressure driven and thermally driven membranes are evaluated for their potential to treat blackwater, by relating selectivity to relevant water quality standards (ISO 30500) and the transmission of volatile organic compounds (VOCs) that are primarily associated with faecal odour, and thus constitute a critical challenge to water reuse. Both pressure driven (reverse osmosis) and thermally driven (membrane distillation and pervaporation) membranes were able to produce water that conformed to category B of the ISO 30500 standard for the majority of determinants. A critical limiting factor was in the selectivity for ammonia and odorous VOCs which were generally poorly removed by reverse osmosis and membrane distillation. The high ammonia transmission was accounted for by the elevated pH of blackwater which shifted the ammonium equilibria toward volatile ammonia which is poorly separated by RO polymers, and is free to diffuse through the gas-filled micropores of the membrane distillation membrane. In contrast, greater ammonia and VOC separation was evidenced for the pervaporation membrane due to advanced polymer–solute interactions. In a preliminary assessment, the hydrophilicity exhibited by the membrane was also advantageous to withstanding fouling. If complemented with a polishing step to target the residual COD and VOCs (that may be of similar origin), pervaporation could deliver to category A standard for non-potable reuse. This is particularly advantageous for water scarce regions where solar or liquified fuels may be applied in favour of electricity for off-grid sanitation.Bill & Melinda Gates FoundationThis publication is based on research funded by the Bill & Melinda Gates Foundation.Environmental Science: Water Research & Technolog
A certifiable AI-based braking control framework for landing using scientific machine learning
Get PDFThis paper proposes an AI-based braking control system for aircraft during landing. Utilizing scientific machine learning, we train an agent to apply the most effective braking strategy under various landing conditions. This approach ensures physically consistent outputs by grounding the algorithm in the principles of landing physics. Our results demonstrate that the aircraft can successfully decelerate without skidding across all runway conditions and landing speeds. Additionally, the algorithm maintains performance and safety even when brake performance degradation and initial yaw angles are introduced. This robustness is crucial for the certification of AI in safety-critical systems, as the proposed framework provides a reliable and effective solution.Innovate UKThis work is part of the LANDOne project, funded by Innovate UK, a part of UK Research and Innovation, under grant number 10002411. DAS – No (Gemma copied in as UKRI funded)2024 AIAA DATC/IEEE 43rd Digital Avionics Systems Conference (DASC
Modular model and simulation for process optimisation in advanced material recovery facilities (MRFs)
Get PDFAt a time when the supply of critical materials is threatened, waste recycling and reuse is an essential solution for human development. The role of Material Recovery Facilities (MRFs) to deliver efficiently high-purity material fractions as feedstock cannot be underestimated. However, MRF sorting processes need to remain adaptive with evolving smart technologies and systems that further enhance their effectiveness. For example, a re-designed MRF with AI-based robotics can improve the performance of waste recycling, leading to significant economic and environmental benefits. This study assesses the performance of potential optimisation methods for future proofing MRFs using modular simulation methods. The authors set out to review current robotics sorting technology and pointed out the challenge of efficiency analysis with multiple variables. The study develops a new conceptual model of efficiency analysis considering the identification and sorting limitations of robots, as well as the coordination requirements between robots and conveyor belts. A computational model is designed and developed by modularity program codes to help practitioners gain insight into the MRF performance by modifying the variables (composition of input waste, separation coefficients and configurations) and analysing the resulting assessment factors (purity and recovery). In the end, this study demonstrates the performance of the optimisation methods of MRF (two target materials for one robot and recirculation loops) through simulation.34th CIRP Design Conference 2024Procedia CIR
Numerical simulation of the inviscid Taylor-Green Vortex using a Discontinuous Galerkin method with adaptive filtering to stabilize the solution: data
No full textNumerical simulation of the inviscid Taylor-Green Vortex using a Discontinuous Galerkin method with adaptive filtering to stabilize the solution.The UK Turbulence Consortiu
Data Supporting "Study of Orifice Design on Oleo-Pneumatic Shock Absorber"
No full textThis data contain the results of the paper.Landing Advances for a New Decade One "LANDOne