Designing a Solid Waste Infrastructure Management Model for Integration into a National Infrastructure System-of Systems

Solid waste management is arguably one of the most important municipal services provided by government1. Given the rapid socio-economic changes that are projected to take place in the UK2 it is important that we plan our future waste management capacity to ensure the continuance of this valuable service. The Solid Waste Infrastructure Management System (SWIMS) model was designed to model the current solid waste infrastructure requirements (from collection through treatment and disposal) for an area based on its solid waste arisings. SWIMS allows an area’s waste treatment capacity requirements to be forecast against future socio-economic change to help decision-makers choose the right solid waste infrastructure given their goals, constraints and ideas about future conditions. The modelling of solid waste management systems has been carried out since the 1970s3 and such modelling exercises have been undertaken for numerous different geographical areas around the world4. However, the SWIMS model is unique in that it was designed to also operate within a larger national infrastructure system-of-systems model, including interdependencies with other infrastructure sectors including energy, water and waste water. To achieve such flexibility the SWIMS model was carefully designed using object-oriented programming (OOP) principles. In documenting this model’s design methodology we hope to demonstrate how applying OOP principles enables such models to not only be more flexible and more easily integrated with other modelling efforts, but also more easily understood by system experts and end-users

Thermal Conductivity of Simulated Soils by the Needle Probe Method for Energy Foundation Applications

Soil thermal conductivity is an important parameter in the design of ground source heat pump and energy foundation systems. A laboratory method for measuring the soil thermal conductivity is the needle probe method. Earlier, analysis of the needle probe test data has been simplistic, relying heavily on human judgment and rules of thumb. This article presents an alternative method of analyzing the needle probe data with the aid of MATLAB, which is a technical programming language and computing environment. Four agar–kaolin specimens of varying densities were prepared to resemble simple soils. These were tested using the needle probe for a range of heating times and heating powers, to see what effect these parameters would have on the results. The repeatability when keeping the heating time and heating power constant was within ±2%. When the heating time and heating power were varied, the variation in results from the average for a given specimen ranged from ±4% to +10%/–8%. This range is significantly higher than the repeatability. Possible reasons for this are discussed in this article

The influence of tree root water uptake on the long term hydrology of a clay fill railway embankment

This paper uses a numerical model to investigate the influence of tree root water uptake and tree removal on pore water pressures and the vertical movement of a clay fill railway embankment. Simulated results of soil wetting and drying are compared with field measurements from an instrumented railway embankment before and after tree removal. A parametric study compares the influence of vegetation on the seasonal movement of the embankment slope. The simulations and field measurements show that while trees cause significant seasonal variations in pore water pressure and water content near the soil surface, they can maintain persistent soil suctions at depth within the tree rooting zone. Demonstration of this result using a numerical model requires a root water uptake function that separates spatially the processes of water infiltration, evaporation and transpiration. When all of the trees are removed, the persistent soil suctions established by the trees are lost as water infiltrates from the soil surface. Leaving the trees in place over the bottom third of the slope can maintain persistent suctions at the slope toe, while potentially also reducing seasonal ground movements at the crest that may adversely affect railway track geometry

CD4+CD25+ TR Cells Suppress Innate Immune Pathology Through Cytokine-dependent Mechanisms

CD4+CD25+ regulatory T (TR) cells can inhibit a variety of autoimmune and inflammatory diseases, but the precise mechanisms by which they suppress immune responses in vivo remain unresolved. Here, we have used Helicobacter hepaticus infection of T cell–reconstituted recombination-activating gene (RAG)−/− mice as a model to study the ability of CD4+CD25+ TR cells to inhibit bacterially triggered intestinal inflammation. H. hepaticus infection elicited both T cell-mediated and T cell–independent intestinal inflammation, both of which were inhibited by adoptively transferred CD4+CD25+ TR cells. T cell–independent pathology was accompanied by activation of the innate immune system that was also inhibited by CD4+CD25+ TR cells. Suppression of innate immune pathology was dependent on T cell–derived interleukin 10 and also on the production of transforming growth factor β. Thus, CD4+CD25+ TR cells do not only suppress adaptive T cell responses, but are also able to control pathology mediated by innate immune mechanisms

Expression of CD45RC and Ia Antigen in the Spinal Cord in Acute Experimental Allergic Encephalomyelitis: An Immunocytochemical and Flow Cytometric Study

We performed immunocytochemical studies to analyze the inflammatory infiltrate and major histocompatibility complex class II (Ia) antigen expression in the spinal cord of Lewis rats with acute experimental allergic encephalomyelitis (EAE) induced by inoculation with myelin basic protein and adjuvants. Using antibodies to lymphocyte markers and other monoclonal antibodies we found that during clinical episodes the inflammatory infiltrate was chiefly composed of T lymphocytes and macrophages. The majority of cells in the inflammatory infiltrate were stained by the W3/25 antibody to CD4 and a proportion was stained by OX22 which labels the high molecular weight form of the leucocyte common antigen (CD45RC). CDB+ T cells were sparse and B cells were not detected. There was minimal staining with the OX39 antibody to the interleukin-2 receptor. Presumptive microglia, identified by their dendritic morphology, expressed Ia antigen during the clinical episodes and after recovery. The prominence of Ia antigen expression after recovery could indicate that this la expression was associated with downregulation of the encephalitogenic immune response. We also performed flow cytometry studies on cells extracted from the spinal cord of rats before and during attacks of EAE. With flow cytometry, we found that in established disease a mean of 83(SD, 23)% of CD2+ cells were CD4+, and a mean of 27(SD, 12)% of CD2+ cells were CD45RC+. In rats sampled on the first day of signs, a mean of 43(SD, 22)% of CD2+ cells were CD45RC+. In the cells extracted from the spinal cord of rats with established disease a mean of 47(SD, 32)% of macrophages were CD45RC+. Our study has combined an immunocytochemical assessment of tissue sections with quantitative flow cytometry assessment of cells extracted from the spinal cord of rats with acute EAE. We have shown that the majority of T lymphocytes in the spinal cord are CD45RC-. We have also found prominent Ia expression on dendritic cells in acute EAE and after clinical recovery

Mechanisms of root reinforcement in soils:An experimental methodology using four-dimensional X-ray computed tomography and digital volume correlation

Vegetation on railway or highway slopes can improve slope stability through the generation of soil pore water suctions by plant transpiration and mechanical soil reinforcement by the roots. To incorporate the enhanced shearing resistance and stiffness of root-reinforced soils in stability calculations, it is necessary to understand and quantify its effectiveness. This requires integrated and sophisticated experimental and multiscale modelling approaches to develop an understanding of the processes at different length scales, from individual root-soil interaction through to full soil-profile or slope scale. One of the challenges with multiscale models is ensuring that they sufficiently closely represent real behaviour. This requires calibration against detailed high-quality and data-rich experiments. This study presents a novel experimental methodology, which combines in situ direct shear loading of a willow root reinforced soil with X-ray computed tomography to capture the 3D chronology of soil and root deformation within the shear zone. Digital volume correlation (DVC) analysis was applied to the computed tomography (CT) dataset to obtain full-field 3D displacement and strain information. This paper demonstrates the feasibility and discusses the challenges associated with DVC experiments on root-reinforced soils

Modelling of stress transfer in root-reinforced soils informed by four-dimensional X-ray computed tomography and digital volume correlation data

Vegetation enhances soil shearing resistance through water uptake and root reinforcement. Analytical models for soils reinforced with roots rely on input parameters that are difficult to measure, leading to widely varying predictions of behaviour. The opaque heterogeneous nature of rooted soils results in complex soil-root interaction mechanisms that cannot easily be quantified. The authors measured, for the first time, the shear resistance and deformations of fallow, willow-rooted, and gorse-rooted soils during direct shear using X-ray computed tomography and digital volume correlation. Both species caused an increase in shear zone thickness, both initially and as shear progressed. Shear zone thickness peaked at up to 35 mm, often close to the thickest roots and towards the centre of the column. Root extension during shear was 10-30% less than the tri-linear root profile assumed in a Waldron-type model, owing to root curvature. Root analogues used to explore the root-soil interface behaviour suggested that root lateral branches play an important role in anchoring the roots. The Waldron-type model was modified to incorporate non-uniform shear zone thickness and growth, and accurately predicted the observed, up to seven-fold, increase in shear resistance of root-reinforced soil

Upgrade of the Glasgow photon tagging spectrometer for Mainz MAMI-C

The Glasgow photon tagging spectrometer at Mainz has been upgraded so that it can be used with the 1500 MeV electron beam now available from the Mainz microtron MAMI-C. The changes made and the resulting properties of the spectrometer are discussed.Comment: 20 pages, 12 figure