Handheld X-Ray Fluorescence Analysis (HH-XRF): a non-destructive tool for distinguishing sandstones in historic structures

Determining the provenance of building stone can be important when researching the history of historic structures or identifying suitable substitute stone to use in building repairs. Commonly, however, there is no written record of stone source, and a visual examination alone is inconclusive. In many such situations stone provenance can only be constrained with confidence if the stone has a distinctive property or character that allows it to be distinguished from, or matched with, other stones. A small proportion of stones have one or more genuinely distinctive visual characteristics that uniquely confirm their provenance, but for most stones such distinctive properties, if they exist at all, are cryptic and usually revealed only by microscope examination or bulk chemical analysis. However, collecting and analysing representative hand samples for this purpose can be difficult, timeconsuming and damaging to historic structures. Handheld X-Ray Fluorescence analysis offers the potential to provide bulk composition data without the need to collect physical samples. HH-XRF instruments are lightweight, wireless and portable, and they provide a rapid, non-destructive means of analysing most materials in a wide range of settings. This study has examined the benefits and limitations of the instrument when applied to sandstone building stones from the UK. A programme of laboratory tests has been used to: develop a robust methodology for gathering, managing, displaying and interpreting data; determining the extent to which sample surface condition affects the analytical results; and assessing the degree to which different sandstones can be distinguished on the basis of their bulk composition. The results are promising: the data can be used to compare, distinguish and match visually indistinguishable sandstones (and potentially a wide range of other geological and man-made materials) quickly and easily, and as such the method should find widespread application in disciplines such as building conservation and archaeology

Scotland's building stone industry: a review

Scotland has one of the richest legacies of traditional (pre-1919) buildings and other stone structures of any country in the world, but the building stone industry that created that legacy is now a small fraction of its former size and struggling to survive as the use of imported stone continues to grow. This report presents an objective review of the building stone industry in Scotland today. It includes: a brief synopsis of its history; evidence of its current fragile state, and the threat this poses to the historic and natural environments; an analysis of the potential for the industry to grow, and the benefits that a stronger indigenous industry could bring; a description of factors that are holding back its development (‘barriers to growth’); and a list of practical steps that can be taken by the industry and other stakeholders to encourage and facilitate growth

Deep geothermal energy potential in Scotland

Geothermal energy is simply the natural heat that exists within our planet. In some parts of the world the existence of a geothermal energy resource is made obvious by the presence of hot springs, and such resources have been exploited in various ways for millennia. More usually, there is no direct evidence at Earth‘s surface of the vast reservoir of stored heat below, and geothermal energy has remained largely ignored and untapped in most parts of the world. Now, its potential as a renewable source of energy is being recognised increasingly, and technologies and concepts for exploiting it are developing rapidly along two lines: low enthalpy (low temperature) resources, which exploit warm water in the shallow subsurface to provide heat either directly (as warm water) or indirectly (via heat exchange systems); and high enthalpy (high temperature) resources, which yield hot water, usually from deeper levels, that can be used to generate electricity. The potential for harnessing electricity from geothermal energy has long been recognised; the potentially substantial reserves, minimal environmental impact, and capacity to contribute continuously to base load electricity supply make it an extremely attractive prospect. The ongoing drive to develop renewable sources of energy, coupled with anticipated technological developments that will in future reduce the depth at which heat reservoirs are considered economically viable, means there is now a pressing need to know more about the deep geothermal energy potential in Scotland. This report contains the British Geological Survey (BGS) contribution to a collaborative project between AECOM and BGS to produce a qualitative assessment of deep geothermal energy potential in onshore Scotland for the Scottish Government. BGS‘s role is to provide the Stage One deliverable ―Identifying and assessing geothermal energy potential‖, comprising an assessment of areas in Scotland most likely to hold deep geothermal resources based on existing geological and geothermal data sets. The report is divided into two parts. Part 1 sets out the background to geothermal energy, describes the geological context, and presents an analysis of the size and accessibility of the heat resource in Scotland based on existing geothermal data. The potential for exploiting deep geothermal energy in three settings in inshore areas of Scotland (abandoned mine workings, Hot Sedimentary Aquifers, and Hot Dry Rocks) is examined in Part 2

A Building Stone Assessment of sandstone in Iona Nunnery and at Carsaig quarry on Mull

This report presents the outcomes of a project commissioned by Historic Scotland to determine, using a combination of archival records and geological evidence, whether blocks of sandstone in Iona Nunnery (a Scheduled Monument on the island of Iona) came from Carsaig quarry (a long-disused quarry on the south coast of Mull). The report also considers the feasibility of sourcing new stone to use in future repairs to the nunnery from Carsaig quarry and from the remains of nearby Carsaig pier. Details of the most suitable commercially available stones from elsewhere in the UK are also provided, should it prove not possible or not practical to obtain new stone from Carsaig quarry or Carsaig pier

A building stone assessment of The Engine Shed, Stirling

This report describes the outcomes of a project commissioned by Historic Scotland to identify suitable stone to use in forthcoming repairs to the building known as The Engine Shed, in Stirling, which will become Historic Scotland’s National Conservation Centre. A Building Stone Assessment has been conducted on three samples of sandstone supplied by Historic Scotland – two from different parts of The Engine Shed and one from the recently demolished Seaforth Place Bridge in Stirling – with a view to assessing whether stone recovered from the demolished bridge could be considered amongst the closest-matching currently available stones and therefore a suitable replacement stone. This assessment has shown that stone from the bridge is amongst the closest-matching stones, and should provide a good replacement stone for walling and copestones in The Engine Shed provided weathered stone is first removed from the recycled blocks and any blocks required to perform a load-bearing function are subjected to a geotechnical test to confirm they are sufficiently strong. Drumhead sandstone, which is currently quarried near Denny, should also provide a good replacement stone

Handheld x-Ray fluorescence : a method for non-destructive compositional analysis of sandstone building stones

This report describes a study designed to devise an appropriate methodology for using a Handheld X-Ray Fluorescence (HH-XRF) instrument for in situ testing of sandstone building stones. HH-XRF is a non-destructive method of compositional analysis that could offer the means to geochemically differentiate different sandstones, and constrain their quarry sources. To examine the potential of HH-XRF for these purposes, a programme of laboratory tests has been conducted on a range of sandstone building stones from the UK. The aims of the test programme were to: develop and refine a robust and fit-for-purpose methodology for gathering, managing, displaying and interpreting compositional data; determine the extent to which sample surface condition and stone texture affect the results; and evaluate whether or not the results can provide a basis for distinguishing different sandstones. The results suggest the instrument can be used to distinguish sandstones (and potentially a wide range of other geological and man-made materials) that are otherwise indistinguishable in the field, and as such the method should find widespread application in disciplines such as building conservation and archaeology

Application of mineralogical, petrological and geochemical tools for evaluating the palaeohdrogeological evolution of the PADAMOT study sites

The role of Work Package (WP) 2 of the PADAMOT project – ‘Palaeohydrogeological Data Measurements’ - has been to study late-stage fracture mineral and water samples from groundwater systems in Spain, Sweden, United Kingdom and the Czech Republic, with the aim of understanding the recent palaeohydrogeological evolution of these groundwater systems. In particular, the project sought to develop and evaluate methods for obtaining information about past groundwater evolution during the Quaternary (about the last 2 million years) by examining how the late-stage mineralization might record mineralogical, petrographical and geochemical evidence of how the groundwater system may have responded to past geological and climatological changes. Fracture-flow groundwater systems at six European sites were studied: • Melechov Hill, in the Bohemian Massif of the Czech Republic: a shallow (0-100 m) dilute groundwater flow system within the near-surface weathering zone in fractured granitic rocks; • Cloud Hill, in the English Midlands: a (~100 m) shallow dilute groundwater flow system in fractured and dolomitized Carboniferous limestone; • Los Ratones, in southwest Spain: an intermediate depth (0-500 m) dilute groundwater flow system in fractured granitic rocks; • Laxemar, in southeast Sweden: a deep (0-1000 m) groundwater flow system in fractured granitic rocks. This is a complex groundwater system with potential recharge and flushing by glacial, marine, lacustrine and freshwater during the Quaternary; • Sellafield, northwest England: a deep (0-2000 m) groundwater flow system in fractured Ordovician low-grade metamorphosed volcaniclastic rocks and discontinuous Carboniferous Limestone, overlain by a Permo-Triassic sedimentary sequence with fracture and matrix porosity. This is a complex coastal groundwater system with deep hypersaline sedimentary basinal brines, and deep saline groundwaters in crystalline basement rocks, overlain by a shallow freshwater aquifer system. The site was glaciated several times during the Quaternary and may have been affected by recharge from glacial meltwater; • Dounreay, northeast Scotland: a deep (0-1400 m) groundwater flow system in fractured Precambrian crystalline basement overlain by fractured Devonian sedimentary rocks. This is within the coastal discharge area of a complex groundwater system, comprising deep saline groundwater hosted in crystalline basement, overlain by a fracture-controlled freshwater sedimentary aquifer system. Like Sellafield, this area experienced glaciation and may potentially record the impact of glacial meltwater recharge. In addition, a study has been made of two Quaternary sedimentary sequences in Andalusia in southeastern Spain to provide a basis of estimating the palaeoclimatic history of the region that could be used in any reconstruction of the palaeoclimatic history at the Los Ratones site: • The Cúllar-Baza lacustrine sequence records information about precipitation and palaeotemperature regimes, derived largely from the analysis of the stable isotope (δ18O and δ13C) signatures from biogenic calcite (ostracod shells). • The Padul Peat Bog sequence provided information on past vegetation cover and palaeogroundwater inputs based on the study of fossil pollen and biomarkers as proxies for past climate change. Following on from the earlier EC 4th Framework EQUIP project, the focus of the PADAMOT studies has been on calcite mineralization. Calcite has been identified as a late stage mineral, closely associated with hydraulically-conductive fractures in the present-day groundwater systems at the Äspö-Laxemar, Sellafield, Dounreay and Cloud Hill sites. At Los Ratones and Melechov sites late-stage mineralization is either absent or extremely scarce, and both the quantity and fine crystal size of any late-stage fracture mineralization relevant to Quaternary palaeohydrogeological investigations is difficult to work with. The results from the material investigated during the PADAMOT studies indicate that the fracture fillings at these sites are related to hydrothermal activity, and so do not have direct relevance as Quaternary indicators. Neoformed calcite has not been found at these two sites at the present depth of the investigations. Furthermore, the HCO3 - concentration in all the Los Ratones groundwaters is mainly controlled by complex carbonate dissolution. The carbonate mineral saturation indices do not indicate precipitation conditions, and this is consistent with the fact that neoformed calcite, ankerite or dolomite have not been observed petrographically

Transient behavior in Single-File Systems

We have used Monte-Carlo methods and analytical techniques to investigate the influence of the characteristics, such as pipe length, diffusion, adsorption, desorption and reaction rates on the transient properties of Single-File Systems. The transient or the relaxation regime is the period in which the system is evolving to equilibrium. We have studied the system when all the sites are reactive and when only some of them are reactive. Comparisons between Mean-Field predictions, Cluster Approximation predictions, and Monte Carlo simulations for the relaxation time of the system are shown. We outline the cases where Mean-Field analysis gives good results compared to Dynamic Monte-Carlo results. For some specific cases we can analytically derive the relaxation time. Occupancy profiles for different distribution of the sites both for Mean-Field and simulations are compared. Different results for slow and fast reaction systems and different distribution of reactive sites are discussed.Comment: 18 pages, 19 figure

A jump-growth model for predator-prey dynamics: derivation and application to marine ecosystems

This paper investigates the dynamics of biomass in a marine ecosystem. A stochastic process is defined in which organisms undergo jumps in body size as they catch and eat smaller organisms. Using a systematic expansion of the master equation, we derive a deterministic equation for the macroscopic dynamics, which we call the deterministic jump-growth equation, and a linear Fokker-Planck equation for the stochastic fluctuations. The McKendrick--von Foerster equation, used in previous studies, is shown to be a first-order approximation, appropriate in equilibrium systems where predators are much larger than their prey. The model has a power-law steady state consistent with the approximate constancy of mass density in logarithmic intervals of body mass often observed in marine ecosystems. The behaviours of the stochastic process, the deterministic jump-growth equation and the McKendrick--von Foerster equation are compared using numerical methods. The numerical analysis shows two classes of attractors: steady states and travelling waves.Comment: 27 pages, 4 figures. Final version as published. Only minor change

Loss of Baiap2l2 destabilizes the transducing stereocilia of cochlear hair cells and leads to deafness

The transduction of sound waves into electrical signals depends upon mechanosensitive stereociliary bundles that project from the apical surface of hair cells within the cochlea. The height and width of these actin‐based stereocilia is tightly regulated throughout life to establish and maintain their characteristic staircase‐like structure, which is essential for normal mechanoelectrical transduction. Here, we show that BAIAP2L2, a member of the I‐BAR protein family, is a newly identified hair bundle protein that is localized to the tips of the shorter rows of transducing stereocilia in mouse cochlear hair cells. BAIAP2L2 was detected by immunohistochemistry from postnatal day 2.5 (P2.5) throughout adulthood. In Baiap2l2 deficient mice, outer hair cells (OHCs), but not inner hair cells (IHCs), began to lose their third row of stereocilia and showed a reduction in the size of the mechanoelectrical transducer current from just after P9. Over the following post‐hearing weeks, the ordered staircase structure of the bundle progressively deteriorates, such that, by 8 months of age, both OHCs and IHCs of Baiap2l2 deficient mice have lost most of the second and third rows of stereocilia and become deaf. We also found that BAIAP2L2 interacts with other key stereociliary proteins involved in normal hair bundle morphogenesis, such as CDC42, RAC1, EPS8 and ESPNL. Furthermore, we show that BAIAP2L2 localization to the stereocilia tips depends on the motor protein MYO15A and its cargo EPS8. We propose that BAIAP2L2 is key to maintenance of the normal actin structure of the transducing stereocilia in mature mouse cochlear hair cells