9 research outputs found

    An experimental investigation into the role of autoignition in turbulent flame stabilisation

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    This thesis presents experimental and complimentary numerical results based on a turbulent jet in a hot coflow burner (JHC). The thesis focuses on understanding and exploring the relative importance of autoignition in the flame stabilisation process for the conditions, temperatures and fuels considered. The influence of fuel type is explored using a range of gaseous fuels including: alkanes, alkenes, H2 and dimethyl ether (DME). High-speed (10 kHz) measurements of chemiluminescence and sound are applied to all flame cases, for all fuels, the measurements are used to temporally resolve the interaction of the flame base with ignition kernels. Similar flame-base and ignition kernel interaction characteristics are found for all fuels where the formation and merging of rapidly growing ignition kernels stabilise these flames. A measurement campaign employing 10 kHz OH and CH2O Planar Laser Induced Fluorescence combined with volumetric chemiluminescence imaging is applied to the ignition kernel formation region in DME flames. The measurements identify regions of low and high-temperatures respectively, with their spatial overlap representing heat release. The kernel heat release measurements indicate that differing degrees of autoignition stabilisation occurs for DME flames, specific to high and low coflow temperature flames. High coflow temperature flames produce lower heat release ignition-kernels; hence these flames are believed to have reduced dependence on autoignition for stability. Zero-dimensional and one-dimensional numerical simulation results, obtained in this thesis, agree with the findings from the hot coflow experiments. The 0-D ignition delay times are shown to successfully capture the different fuels lift-off height sensitivities with coflow temperature. The sensitivity of relatively low coflow temperatures are particularly well represented by delay times, with a linear correlation between delay times and experimental lift-off heights. To replicate the strained and diffusive conditions induced by the JHC burner, unsteady 1-D counter-flow simulations were applied. These simulations, using DME, identify that for high coflow temperature flames, the ignition kernels produce lower heat release, since they are igniting leaner. Using CH4 with the same counter-flow setup, the effect of strain-rate was explored. It was found that increased strain rate delays ignition, since the unity balance between diffusion and production fluxes of CH2O is also delayed. Furthermore, under autoignition conditions, the counter-flow solver, in addition to a premixed solver, show CH2O convection and production fluxes increase, with a corresponding diffusive decrease

    Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

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    Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field

    Molecular Mechanisms Of Cell Death: Recommendations Of The Nomenclature Committee On Cell Death 2018

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    Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field

    ILC Reference Design Report Volume 1 - Executive Summary

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    The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2s^-1. This report is the Executive Summary (Volume I) of the four volume Reference Design Report. It gives an overview of the physics at the ILC, the accelerator design and value estimate, the detector concepts, and the next steps towards project realization.The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2s^-1. This report is the Executive Summary (Volume I) of the four volume Reference Design Report. It gives an overview of the physics at the ILC, the accelerator design and value estimate, the detector concepts, and the next steps towards project realization

    ILC Reference Design Report Volume 4 - Detectors

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    This report, Volume IV of the International Linear Collider Reference Design Report, describes the detectors which will record and measure the charged and neutral particles produced in the ILC's high energy e+e- collisions. The physics of the ILC, and the environment of the machine-detector interface, pose new challenges for detector design. Several conceptual designs for the detector promise the needed performance, and ongoing detector R&D is addressing the outstanding technological issues. Two such detectors, operating in push-pull mode, perfectly instrument the ILC interaction region, and access the full potential of ILC physics.This report, Volume IV of the International Linear Collider Reference Design Report, describes the detectors which will record and measure the charged and neutral particles produced in the ILC's high energy e+e- collisions. The physics of the ILC, and the environment of the machine-detector interface, pose new challenges for detector design. Several conceptual designs for the detector promise the needed performance, and ongoing detector R&D is addressing the outstanding technological issues. Two such detectors, operating in push-pull mode, perfectly instrument the ILC interaction region, and access the full potential of ILC physics

    ILC Reference Design Report Volume 3 - Accelerator

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    The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2 s^-1. The complex includes a polarized electron source, an undulator-based positron source, two 6.7 km circumference damping rings, two-stage bunch compressors, two 11 km long main linacs and a 4.5 km long beam delivery system. This report is Volume III (Accelerator) of the four volume Reference Design Report, which describes the design and cost of the ILC.The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2 s^-1. The complex includes a polarized electron source, an undulator-based positron source, two 6.7 km circumference damping rings, two-stage bunch compressors, two 11 km long main linacs and a 4.5 km long beam delivery system. This report is Volume III (Accelerator) of the four volume Reference Design Report, which describes the design and cost of the ILC

    International Linear Collider Reference Design Report Volume 2: PHYSICS AT THE ILC

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    This article reviews the physics case for the ILC. Baseline running at 500 GeV as well as possible upgrades and options are discussed. The opportunities on Standard Model physics, Higgs physics, Supersymmetry and alternative theories beyond the Standard Model are described.This article reviews the physics case for the ILC. Baseline running at 500 GeV as well as possible upgrades and options are discussed. The opportunities on Standard Model physics, Higgs physics, Supersymmetry and alternative theories beyond the Standard Model are described
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