Thermal transport and chemical conversion in single reacting sorbent particles

The effects of particle size and carbon dioxide concentration on chemical conversion in engineered spherical particles undergoing calcium oxide looping are investigated. Particles are thermochemically cycled in a furnace under different carbon dioxide concentrations. Changes in composition due to chemical reactions are measured using thermogravimetric analysis. Gas composition at the furnace exit is evaluated with mass spectroscopy. A numerical model of thermal transport phenomena developed previously is adapted to match the physical system investigated in the present study. The model is used to elucidate effects of reacting medium characteristics on particle temperature and reaction extent. Experimental and numerical results show that (1) an increase in particle size results in a decrease in carbonation extent, and (2) the carbonation step consists of fast and slow reaction regimes. The reaction rates in the fast and slow carbonation regimes increase with increasing carbon dioxide concentration. The effect of carbon dioxide concentration and the distinction between the fast and slow regimes become more pronounced with increasing particle size.     

(Re)conceptualising the boundaries between home and homelessness: the unheimlich

A burgeoning cross-disciplinary literature signifies a move towards diversifying understandings of the meanings of ‘home’. Homelessness is inextricably bound up in these definitions. While earlier work has considered meanings of homelessness, attempts to advance understandings of the relationship between home and homelessness have been sporadic. This article attempts to reinvigorate discussion around the home–homelessness relationship by problematizing the binaries in current understandings and poses a different way of theorizing the interplay between the two concepts. Drawing on interviews with women accessing homelessness services in the North of England, discussion interweaves women’s meanings of home and homelessness with the Freudian notion of the ‘unheimlich’. The ‘unheimlich’ captures the uncanny process of inversion whereby the familiar domestic sphere of the house turns into a frightening place; and a typical space of homelessness—the hostel—is considered home. The article seeks to contribute more adequate theoretical tools for future research to better understand and articulate the complexities of home and homelessness.     

Group IVB metallocene polyesters containing camphoric acid and preliminary cancer cell activity

Polyesters were formed from the reaction of the salt of camphoric acid and Group IVB metallocene dichlorides using the interfacial polycondenzation process. The polyesters were formed in good yields with moderate chain lengths. Fourier transform infrared spectroscopy shows bands characteristic of the presence of both reactants with new bands characteristic of the formation of the M?O and M–O(CO) linkage present. The polymers largely exist in a bridging geometry of the carbonyl groups about the metal atom. Nuclear magnetic resonance shows the presence of bands derived from both reactants. Matrix-assisted laser desorption/ionization mass spectroscopy shows ion fragments to three units for the polymers with isotopic abundance characteristic of the presence of metal atoms in the ion fragment clusters. All the polymers exhibit good ability to inhibit all the tested cancer cell lines but the zironocene and hafnocene polymers exhibit especially good inhibition of the tested cancer cell lines that included two pancreatic cancer cell lines. They represent a potential new group of anticancer drugs.     

Biomimetic Approach for the Production of 3D Woven Spherical Composite Applied in Apparel Protection and Performance

Applied Composite Materials - Current sports bras are typically manufactured via a cut and sew process resulting in a high volume of post-production material waste. Seams derived from this cut and...     

Lake extent changes in Basotu,Tanzania: a mixed-methods approach to understanding the impacts of anthropogenic influence and climate variability

Incompatible land use is a major contributor to ecosystem degradation, and is often exacerbated by climate change impacts. We investigate Lake Basotu, Tanzania as a case study where natural lake variability has been affected by agricultural land use. Comparisons between a satellite-derived history of lake surface area, local precipitation records, and corresponding anthropogenic activity show the impacts of agricultural and historical practices. We argue that insufficient consideration to the wider ecological impacts of large agricultural projects has lasting implications. This is particularly true in semi-arid environments where food production demands need to be continuously met. In the future, major conservation strategies should be investigated to maintain the environmental integrity and sustainability of freshwater resources.     

Stream quality in a small urbanised catchment

River-length patterns in the chemistry and biology of the Charlton Brook, an unclassified watercourse in Sheffield, England, have been examined. Five sampling sites for macroinvertebrates and pollutant analysis were used, in conjunction with Environment Agency's General Quality Assessment (GQA) methodologies and hydraulic analysis of the catchment. Sites were strategically located to account for the tributaries and the brook downstream of their confluence, to assess the potential impact from surface water outfalls (SWOs). Variations in GQA parameters indicate a significant drop in quality downstream of the SWOs that discharge to the study watercourse, with a marked drop in biological diversity noted at the onset of urbanisation. The decline in biological quality however is greater than that suggested by physicochemical analysis alone. There was a significant inverse relationship between impermeable area and biological diversity. Analysis of polycyclic aromatic hydrocarbons (PAHs) and trace metals in sediment from the watercourse showed significant yet irregular variations between sites. The potential toxicity of instream metal concentrations was determined using cumulative criterion unit (CCU) scores, which highlighted cadmium, copper and lead as the major sources of potential chronic instream toxicity. The threshold for likely harm to aquatic life is exceeded at all sites. In the absence of different physical characteristics, comparisons of the chemical and biological data indicate that the benthic macroinvertebrate population of such watercourses are adversely affected by the stormwater inputs.