Techno-economic analysis of supercritical carbon dioxide power blocks

Developing highly efficient power blocks holds the key to enhancing the cost competitiveness of Concentration Solar Thermal (CST) technologies. Supercritical CO (sCO) Brayton cycles have proved promising in providing equivalent or higher cycle efficiency than supercritical or superheated steam cycles at temperatures and scales relevant for Australian CST applications. In this study, a techno-economic methodology is developed using a stochastic approach to determine the ranges for the cost and performance of different components of central receiver power plants utilizing sCO power blocks that are necessary to meet the Australian Solar Thermal Initiative (ASTRI) final LCOE target of 12 c/kWh

Creating and curating an archive: Bury St Edmunds and its Anglo-Saxon past

This contribution explores the mechanisms by which the Benedictine foundation of Bury St Edmunds sought to legitimise and preserve their spurious pre-Conquest privileges and holdings throughout the Middle Ages. The archive is extraordinary in terms of the large number of surviving registers and cartularies which contain copies of Anglo-Saxon charters, many of which are wholly or partly in Old English. The essay charts the changing use to which these ancient documents were put in response to threats to the foundation's continued enjoyment of its liberties. The focus throughout the essay is to demonstrate how pragmatic considerations at every stage affects the development of the archive and the ways in which these linguistically challenging texts were presented, re-presented, and represented during the Abbey’s history

Using CFD analysis to optimise top submerged lance furnace geometries

The gas offtake design is an important aspect of the Top Submerged Lance (TSL) furnace technology. CFD modelling has been used to investigate the gas offtake geometry to better understand and address common industrial issues. The objective of the study was to understand how the shape of the offtake affected emissions from the roof ports, and influenced both the location of the post combustion reactions and the flow profile of the gas within the vessel and waste heat boiler (WHB). The conditions and gas species included in the modelling are based on typical large industrial copper smelters. Commercial software (ANSYS-FLUENT) has been used to investigate design variants by incorporating the effects of momentum, multi-component mixing, radiative and convective heat transfer, combustion reactions, and buoyancy. The learnings from the CFD modelling were integrated into the design of the new Novasmelt™ TSL technology.publishedVersio

Using CFD analysis to optimise top submerged lance furnace geometries

The gas offtake design is an important aspect of the Top Submerged Lance (TSL) furnace technology. CFD modelling has been used to investigate the gas offtake geometry to better understand and address common industrial issues. The objective of the study was to understand how the shape of the offtake affected emissions from the roof ports, and influenced both the location of the post combustion reactions and the flow profile of the gas within the vessel and waste heat boiler (WHB). The conditions and gas species included in the modelling are based on typical large industrial copper smelters. Commercial software (ANSYS-FLUENT) has been used to investigate design variants by incorporating the effects of momentum, multi-component mixing, radiative and convective heat transfer, combustion reactions, and buoyancy. The learnings from the CFD modelling were integrated into the design of the new Novasmelt™ TSL technology

Physical disturbance of an upland grassland influences the impact of elevated UV-B on metabolic profiles of below-ground micro-organisms.

This investigation determined the response of soil microbial communities to enhanced UV-B radiation and disturbance in upland grassland. A factorial field experiment encompassing two levels of UV-B supplementation (simulating ambient and a 30% increase in stratospheric ozone) and two levels of disturbance (disturbed and undisturbed) was established at Buxton Climate Change Impacts Laboratory, Derbyshire, UK, and maintained for 7 years prior to sampling. Enhanced UV-B increased microbial utilization of carbohydrates, carboxylic acids, polymers and aromatic compounds present in Biolog® GN plates when inoculated with soils taken from disturbed plots, but did not affect carbon utilization of soil microbial communities associated with undisturbed plots (UV-B×Disturbance interaction, P<0.05 for each substrate type). UV-B treatment did not affect numbers of bacteria or fungi. Direct microscopic counts showed fewer bacteria in soil originating from disturbed plots than from undisturbed plots (Disturbance, P<0.001), although a greater number of culturable bacteria and fungi were isolated from disturbed than from undisturbed soils (Disturbance, P<0.001). No UV-B- or disturbance-related differences in protein, starch or urea hydrolysis were exhibited by bacterial isolates. UV-B treatment did not affect total plant biomass within undisturbed plots or the biomass of individual groupings of grasses, forbs and mosses. Per cent root length colonized by arbuscular mycorrhizal fungi (AMF) was not affected by enhanced UV-B radiation in the undisturbed plots. Neither AMF nor plant biomass was measured in disturbed plots. The key findings of this study show that UV-B-mediated alterations in carbon utilization occurred in soil microbial communities subjected to disturbance, but such changes were not observed in communities sampled from undisturbed grassland. Differences in the catabolic potential of microbial communities from disturbed grassland subjected to enhanced UV-B are probably related to plant-mediated changes in resource availability or quality

Tall tales from the archive

The administrative documents preserved in archives tell stories which are shaped by their institutional and governmental context, and are as deceptive and full of invention as more self-consciously literary works. Medieval archives contain a vast repository of historical narratives which, despite their fictional components and bureaucratic manipulation, nevertheless provide vivid insights into everyday life. The rhetorical conventions of such bureaucratic documents as pardons, petitions and appeals represent forms of historical literature which are cultural productions of equal significance to the chronicle or the epic poem. But, unlike court poetry or chronicles, the archives tell us a great deal about the life of ordinary people. In the wake of the discussion of the archive by Foucault and Derrida, the archive has been seen as a symbol of power and a means of control, but often the archive is the chief means by which non-elite groups find their voice

Gildas

International audienceGildas est le premier auteur britannique à témoigner des événements postérieurs au départ des légions romaines. C'est par l'analyse de ses modèles, principalement bibliques, et de ses buts que son récit historique allusif, si frustrant, peut être compris et interprété comme un témoignage de premier plan