Assessment of plastics in the National Trust: a case study at Mr Straw's House

The National Trust is a charity that cares for over 300 publically accessible historic buildings and their contents across England, Wales and Northern Ireland. There have been few previous studies on preservation of plastics within National Trust collections, which form a significant part of the more modern collections of objects. This paper describes the design of an assessment system which was successfully trialled at Mr Straws House, a National Trust property in Worksop, UK. This system can now be used for future plastic surveys at other National Trust properties. In addition, the survey gave valuable information about the state of the collection, demonstrating that the plastics that are deteriorating are those that are known to be vulnerable, namely cellulose nitrate/acetate, PVC and rubber. Verifying this knowledge of the most vulnerable plastics enables us to recommend to properties across National Trust that these types should be seen as a priority for correct storage and in-depth recording

Conservation of wallpapers from St Pancras Chambers

The renovation of St Pancras Chambers (Midland Grand Hotel) in London provided an excellent opportunity for in-depth research into the wallpapers used in decorating this historic building. Initially a hotel owned by Midland Railway, the building was subsequently used as offices and staff accommodation by British Rail before it finally closed in the 1980s. During the restoration project, many wallpapers were uncovered from previously hidden areas, in addition to other papers that were still on view on the walls. All the wallpapers were at high risk from damage and loss during the extensive building works, and in order to keep a record of that evidence wallpapers were collected and removed from the site. Spanning just over 100 years of wallpaper from the 1870s to the 1980s, the papers were cleaned and conserved, and stored within Melinex pockets, acid free envelopes or rolled Melinex, as appropriate. They now comprise a historic wallpaper archive, available for access for researchers, students and other interested parties, held at the University of Lincoln

Characterisation of the artist John Opie’s pigments, dated 1806

This paper discusses the contents of an artist’s paint box currently in the possession of St. Agnes Museum, Cornwall, UK, containing a selection of historic pigments. On its lid is a metal plaque that reads ‘John Opie 1806’. Very little is known about this paint box, so this piece of research aims to uncover some of the hidden information stored within it through identification of some of the pigments it contains. The main body of this research shows the first results obtained by the identification of a selection of the pigments from the paint box, using Fourier Transform Infra Red spectroscopy (FTIR) and optical microscopy techniques. These findings will be considered in relation to what this tells us about the artist John Opie, the authenticity of the pigments within the paint box, and the use of pigments in the early nineteenth century

Shape analysis of railway ballast stones : curvature-based calculation of particle angularity

Particle shape analysis is conducted, to compare two types of railway ballast: Calcite and Kieselkalk. Focus lies on the characterisation of particle angularity using 3D scanner data. In the literature, angularity is often characterised using 2D data, as these types of data are easier to collect. 3D scanner data contain a vast amount of information (e.g. curvatures) which can be used for shape analysis and angularity characterisation. Literature approaches that use 3D data are often not thoroughly tested, due to a lack of test cases. In this work, two new curvature-based angularity indices are introduced and compared to one from the literature. Analytical test bodies with shapes ranging from spherical towards cubic are used for a first plausibility test. Then, 3D scans of ballast stones are compared to artificially rounded meshes. Only one out of three evaluated angularity indices seem to be suited to characterise angularity correctly in all of the above tests: the newly introduced scaled Willmore energy. A complete shape analysis of the scanned ballast stones is conducted and no difference between the two types of ballast can be seen regarding form, angularity, roughness, sphericity or convexity index. These findings of shape analysis are set in the context of previous works, where experimental results and DEM simulations of uniaxial compression tests and direct shear tests were presented for the same ballast types

Zipf ’s Law and Its Correlation to the GDP of Nations

This study looks at power laws, specifically Zipf ’s law and Pareto distributions, previously used to describe city size distribution, income distribution within firms, and word distribution within languages and documents among other things, and Gibrat’s law describing growth rate. This study seeks to discover if Zipf’s law can also be used to model the distribution of GDP’s worldwide using Gibrat’s law as a justification. The simplest method to determine Zipf's law’s applicability, and the one used in this study, was to create a log log plot, plotting rank versus size of the GDPs. Using that plot, Zipf ’s law was verified through two criteria. First the plot must appear linear and second it must have a slope of -1. For the purpose of this study, the data looked at was for all countries and then countries split into categories of emerging economies and advanced economies for the years 2005, 2006, 2007, and 2008. The results of this study showed that all countries and countries with emerging economies did not appear linear on the log log plot while advanced economies appeared linear with a slope roughly -.70, suggesting that GDP distribution of advanced economies instead follow a Pareto distribution. Advanced economies also showed a significantly smaller variation in growth rates over the four years as implied by Gibrat’s law. This was used as a possible explanation for the distribution discovered

Panel. Community Engagement and Interpreting Slavery in North Mississippi

The “Behind the Big House” Project / Jodi Skipper, University of Mississippi and Suzanne DavidsonBehind the Big House is a slave dwelling interpretation program in Holly Springs, Mississippi. The program offers a counter-narrative to the Holly Springs Annual Pilgrimage Tour of Historic Homes and Churches, the city’s main tourist attraction which has historically neglected the contributions of enslaved persons. Behind the Big House was initiated by several private property owners who understood that interpreting the structures which housed enslaved persons could help to remedy such omissions. In addition to discussing how historical memory impacts the functions of these sites in the present, Skipper will discuss her role as a Behind the Big House tour guide, and how she incorporates the tour as an applied component in her courses. Slavery and Its Descendants / W. Ralph Eubanks, University of MississippiThe legacy of slavery and its impact across generations of African Americans is often ignored or overlooked, particularly by institutions that benefited from enslaved labor. The University of Mississippi is no exception. Payment records from the 1840s in the archives of the University of Mississippi indicate that Robert Sheegog—who once owned Faulkner’s home Rowan Oak—along with other local slave owners, loaned slaves to the University. This connection between the slaves of Rowan Oak and the building of the University of Mississippi holds the potential to redefine the idea of legacy connections to the University, since inevitably the descendants of several of those slaves are among the university’s alumni. This paper will discuss the on-going work of the University of Mississippi’s slavery research group and the possible outcomes of planned genealogical research to find the descendants of the slaves from Faulkner’s Rowan Oak who built the university.The University of Mississippi Slavery Research Group / Jeffrey Jackson and Charles K. Ross, University of MississippiIn this presentation, we present the story of the University of Mississippi Slavery Research Group focusing on its origins and the various factors that led to its formation. We highlight some of the groups’ most significant recent efforts to better understand how antebellum slavery shaped the formation of the University of Mississippi and life in North Mississippi generally and we discuss some of our initial projects and initiatives that seek to remember, memorialize and interpret the lives of enslaved people for our students, our local community, and our nation.Interpreting Slavery at Burns Belfry and Rowan Oak / George McDaniel, Burns-Belfry African American History MuseumCaroline Barr was a foundational figure in the life of William Faulkner. As he called her, “Mammy Callie,” she had worked for the Falkner family since he was a young boy. Her house and her story demand a further interpretation beyond the gates of Rowan Oak. Using her as a point of departure, this talk will explore African American history within the larger context of the town of Oxford. It will also look at the ways in which that history is being interpreted today and how that interpretation can be improved through building connections between different historical sites. This connectivity allows for a deeper understanding of African American history in Oxford and the world in which Faulkner lived and wrote

DEM modelling of railway ballast using the Conical Damage Model: a comprehensive parametrisation strategy

Despite ongoing research, the parametrisation of a DEM model is a challenging task, as it depends strongly on the particle shape representation used, particle-particle contact law and the simulated applications: for railway ballast e.g. lab tests or track conditions. The authors previously modelled railway ballast with a DEM model using a simple particle shape. The DEM model was parametrised, by trial-and-error, to compression and direct shear test results. A good agreement between DEM model and experimental results was achieved only when the Conical Damage Model (CDM) was used as the contact law. Compared to the well-known linear-spring Cundall-Strack law or the Hertz-Mindlin law, this contact law takes into account additional physical effects (e.g. edge breakage) occurring in the experiment. Little is known on the influence of the CDM model parameters on the simulation results or on possible parameter ambiguities. This lack of knowledge hinders a reliable and efficient parametrisation of DEM models using different particle shapes. Both points are addressed in this work in detail by investigating a DEM model for railway ballast using one simple particle shape. Suggestions for a parametrisation strategy of reduced computational effort are formulated and tested using a second particle shape. In future works, the newly presented parametrisation strategy can help to calibrate different DEM models and to study the influence of particle shape

Sanded wheel–rail contacts: experiments on sand crushing behaviour

In railway operation, the sanding process is used to overcome low adhesion conditions in the wheel–rail contact. In the literature, previously conducted research has been experimental, e.g., measuring adhesion coefficients (ACs) under different contact conditions (dry, wet, …) or applying different sands. Under dry conditions, sanding can reduce measured ACs, while under wet conditions different types of rail sand can leave ACs unchanged or increase adhesion. Despite active research, the physical mechanisms causing the change in ACs under sanded conditions are still poorly understood. A possible remedy is the development of advanced models of sanding including local effects. As a basis for such a model, this study presents experimental results concerning single grain crushing behaviour of two types of rail sand under dry and wet contact conditions. Firstly, initial breakage behaviour is investigated with focus on the particle fragments’ size and spread as only fragments within the running band are available to influence the AC during roll-over. Secondly, single grain crushing tests are conducted under realistic wheel–rail load showing the formation of solidified clusters of sand fragments, as well as their size and thickness. This information is important for understanding mechanisms and for future physics-based modelling of the sanding process in wheel–rail contacts