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Tolerable magnitudes for induced seismicity at offshore carbon capture and storage projects
No full textInduced seismicity is a risk that must be managed during the development of Carbon Capture and Storage (CCS) projects. A key step in effective management of induced seismicity is the definition of a tolerable magnitude threshold, MTOL, which defines the level at which the nuisance or damage caused by induced seismicity is likely to no longer be tolerated by affected populations. Having established MTOL, induced seismicity mitigation strategies can be implemented with the objective to avoid induced events that exceed MTOL. In this study our objective is to estimate MTOL for CCS developments in the waters around the UK. Siting CCS operations offshore reduces, but does not eliminate, the risks posed by induced seismicity by increasing the distance from exposed populations. For a given induced earthquake location and magnitude, we use ground motion models, nuisance and fragility functions, and population densities, to estimate the numbers of households that would experience different levels of disturbance and damage. We use past cases of induced seismicity that were, or were not, accepted by the public to define risk tolerances based on the numbers of households that experience different levels of disturbance or damage. We sense-check our results through comparison with observed macroseismic impacts from past, natural earthquakes located in the seas around the UK. As expected, we find that the strongest control on MTOL is the distance to the shore from the proposed project. Our results can be used by CCS operators and regulators in designing induced seismicity mitigation strategies for their sites
Tolerable magnitudes for induced seismicity at offshore carbon capture and storage projects
No full textInduced seismicity is a risk that must be managed during the development of Carbon Capture and Storage (CCS) projects. A key step in effective management of induced seismicity is the definition of a tolerable magnitude threshold, MTOL, which defines the level at which the nuisance or damage caused by induced seismicity is likely to no longer be tolerated by affected populations. Having established MTOL, induced seismicity mitigation strategies can be implemented with the objective to avoid induced events that exceed MTOL. In this study our objective is to estimate MTOL for CCS developments in the waters around the UK. Siting CCS operations offshore reduces, but does not eliminate, the risks posed by induced seismicity by increasing the distance from exposed populations. For a given induced earthquake location and magnitude, we use ground motion models, nuisance and fragility functions, and population densities, to estimate the numbers of households that would experience different levels of disturbance and damage. We use past cases of induced seismicity that were, or were not, accepted by the public to define risk tolerances based on the numbers of households that experience different levels of disturbance or damage. We sense-check our results through comparison with observed macroseismic impacts from past, natural earthquakes located in the seas around the UK. As expected, we find that the strongest control on MTOL is the distance to the shore from the proposed project. Our results can be used by CCS operators and regulators in designing induced seismicity mitigation strategies for their sites
Protocell Flow Reactors for Enzyme and Whole-cell Mediated Biocatalysis
No full textThe design and construction of continuous flow biochemical reactors comprising immobilized biocatalysts have generated great interest in the efficient synthesis of value-added chemicals. Living cells use compartmentalization and reaction-diffusion processes for spatiotemporal regulation of biocatalytic reactions, and implementing these strategies into continuous flow reactors can offer new opportunities in reactor design and application. Herein, the fabrication of protocell-based continuous flow reactors for enzyme and whole-cell mediated biocatalysis is demonstrated. Semipermeable membranized coacervate vesicles are employed as model protocells that spontaneously sequester enzymes or accumulate living bacteria to produce embodied microreactors capable of single- or multiple-step catalytic reactions. By packing millions of the enzyme/bacteria-containing coacervate vesicles in a glass column, a facile, cost-effective, and modular methodology capable of performing oxidoreductase, peroxidase and lipolytic reactions, enzyme-mediated L-DOPA synthesis, and whole-cell glycolysis under continuous flow conditions, is demonstrated. It is shown that the protocell-nested enzymes and bacterial cells exhibit enhanced activities and stability under deleterious operating conditions compared with their non-encapsulated counterparts. These results provide a step toward the engineering of continuous flow reactors based on cell-like microscale agents and offer opportunities in the development of green and sustainable industrial bioprocessing.</p
Protocell Flow Reactors for Enzyme and Whole-cell Mediated Biocatalysis
No full textThe design and construction of continuous flow biochemical reactors comprising immobilized biocatalysts have generated great interest in the efficient synthesis of value-added chemicals. Living cells use compartmentalization and reaction-diffusion processes for spatiotemporal regulation of biocatalytic reactions, and implementing these strategies into continuous flow reactors can offer new opportunities in reactor design and application. Herein, the fabrication of protocell-based continuous flow reactors for enzyme and whole-cell mediated biocatalysis is demonstrated. Semipermeable membranized coacervate vesicles are employed as model protocells that spontaneously sequester enzymes or accumulate living bacteria to produce embodied microreactors capable of single- or multiple-step catalytic reactions. By packing millions of the enzyme/bacteria-containing coacervate vesicles in a glass column, a facile, cost-effective, and modular methodology capable of performing oxidoreductase, peroxidase and lipolytic reactions, enzyme-mediated L-DOPA synthesis, and whole-cell glycolysis under continuous flow conditions, is demonstrated. It is shown that the protocell-nested enzymes and bacterial cells exhibit enhanced activities and stability under deleterious operating conditions compared with their non-encapsulated counterparts. These results provide a step toward the engineering of continuous flow reactors based on cell-like microscale agents and offer opportunities in the development of green and sustainable industrial bioprocessing.</p
Radiocarbon Sample Preparation Procedures and the First Status Report from the Bristol Radiocarbon AMS (BRAMS) Facility
Full text linkThe Bristol Radiocarbon Accelerator Mass Spectrometry (BRAMS) Facility was established at the University of Bristol after the commissioning of our dedicated sample preparation laboratories and the installation and acceptance of the BrisMICADAS AMS in 2016. Routine measurements commenced in mid-2016, once validation was completed for each sample type. Herein, we give an overview of the standard pretreatment methods currently employed in the Facility and the results of radiocarbon (14C) determinations on a wide range of standards, blank materials, and intercomparison samples which have been measured during our extensive pretreatment method validation program and during our routine 14C analyses
Radiocarbon Sample Preparation Procedures and the First Status Report from the Bristol Radiocarbon AMS (BRAMS) Facility
Full text linkThe Bristol Radiocarbon Accelerator Mass Spectrometry (BRAMS) Facility was established at the University of Bristol after the commissioning of our dedicated sample preparation laboratories and the installation and acceptance of the BrisMICADAS AMS in 2016. Routine measurements commenced in mid-2016, once validation was completed for each sample type. Herein, we give an overview of the standard pretreatment methods currently employed in the Facility and the results of radiocarbon (14C) determinations on a wide range of standards, blank materials, and intercomparison samples which have been measured during our extensive pretreatment method validation program and during our routine 14C analyses
Terrestrial Analogs to Titan for Geophysical Research
No full textSaturn’s moon Titan exhibits remarkable parallels to the Earth in many geophysical and geological processes not found elsewhere in the solar system at the present day. These include a nitrogen atmosphere with a condensible gas - methane - replacing the Earth’s water, leading to an active meteorology with rainfall and surface manifestations including rivers, lakes and seas, and the dissolution of karstic terrain. Other phenomena such as craters, dunes, and tectonic features are found elsewhere - e.g. on Mars and Venus - but their continuing alteration by pluvial, fluvial and lacustrine processes can be studied only on Earth and Titan. Meanwhile Titan also hosts an interior liquid water ocean with similarities to the Earth as well as to ocean worlds such as Europa and Enceladus. Our focus in this review paper is twofold: to describe the geophysical and geological parallels between Earth and Titan, and to evaluate the yet-underexploited possibilities for field analog research to gain new knowledge about these processes. To date, Titan’s much colder temperature and different atmospheric and crustal materials have led to a skepticism that useful analogs can be found on Earth. Our conclusion, however, is that a much larger range of useful analog field work is possible and this work will substantially enhance our knowledge of both worlds. Such investigation will supplement the existing sparse data for Titan returned by space missions, will greatly enhance our understanding of such datasets, and will help to provide science impetus and goals for future missions
A novel medical trauma plate using bioactive ceramic composites — design and numerical modelling analysis
No full textIn traditional orthopaedics and traumatology, titanium alloy trauma plates (TATPs) are commonly used as internal fixators for fractured bones, typically with screws. However, this technique presents challenges: TATPs often require removal after healing due to non-degradability and potential corrosion, and their stiffness mismatch with bone can cause stress-shielding that may delay healing. To address these issues, a nacre-like biomimetic apatite-wollastonite composite has been introduced to develop a new trauma plate for orthopedic treatments and prosthetics. This bioactive ceramic composite trauma plate (BCCTP) is fully biocompatible with bone tissue, enabling permanent fixation without later removal.This study proposes an initial design for a biomimetic nacre-like BCCTP composed of apatite-wollastonite hydroxyapatite/poly(methyl methacrylate)-polyacrylic acid (AW-HA/PMMA-PAA). The composite exhibits an elastic modulus comparable to human bone, improving mechanical compatibility by reducing stress concentrations. A finite element method (FEM)-based construct model is established to optimize the structural design and geometric parameters of the BCCTP and its adhesive layer. The results indicate that the construct maintains compressive strains within the callus in the biomechanical range required for bone healing (2%–10%) across all loading cases, providing a foundation for next-generation bone fixation devices
Physical Learning in Soft Fluidic Channels through Experience
No full textFluidic circuits have received increasing interest as a paradigm for implementing computational functionality, e.g., for control in soft robots. However, typically control policies are encoded in circuits that are static, and only a few attempts have been made to realise physical learning capabilities that enable animal-like, real-time adaptation and lifetime development. We introduce the Fluidic Learning Channel (FLC), a physical learning framework that changes flow-conductance through its experienced flow rate history, allowing fluidic circuits to conduct physically embodied online learning. Two demonstrations are presented to validate this concept. The first involves a two-finger system that learns to memorise actuation speed under repetitively applied physical constraint. The second demonstrates a 22 FLC network that learns to map the flow rate at the two input nodes to the target pressure at one of the output nodes. In addition to physical demonstration, simulations were conducted to further explore the essential characteristics and provide insights for future FLC-type embodiment designs