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The geochemistry and petrogenesis of the Lower Paleozoic granitoids of North WalesCroudace, Ian W. January 1980 (has links)
The Lower Paleozoic rocks of North Wales are penetrated by numerous bodies of dolerite and intermediate-acid material which are closely associated with pillow basalts, acid and basic tuffs and ignimbrites. Igneous activity occurred throughout the Ordovician although in Snowdonia and Lleyn it reached a climax during the Caradoc stage. The present study has considered the granitoids of Snowdonia and Lleyn which are intruded as stocks, laccoliths and high level plugs (<5 km2) into clastic and volcaniclastic sediments. A substantial body of new chemical data has been obtained for over thirty intrusions. Twenty-four major and trace elements were determined on each sample by X-ray fluorescence techniques and the rare earth abundances of forty-five selected samples were measured using a radiochemical neutron activation procedure. Three distinctly different types of granitic material are recognised and their possible evolutionary mechanisms are discussed in detail. On the basis of the geochemistries of the various sampled intrusions it is concluded that they were all ultimately derived from the mantle by partial melting. One group originated from the remobilisation of calc-alkaline plutons formed by hydrous melting of the mantle wedge above a destructive plate margin. The other two groups, it is argued, evolved from tholeiitic basaltic magma by low-pressure fractional crystallisation. The goochemical affinity between some Caradocian andesitic material from Lleyn and the tonalitic-granitic intrusions of the same area has provided good evidence against a view that the latter were emplaced late in the Caledonian cycle (Silurian-Devonian). A paleo-tectonic reconstruction of the North Wales region is presented and it is claimed that the area evolved as a volcano-tectonic rift zone, a precursor of a back-arc basin.
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The influence of exposed riverine sediment (ERS) physical habitat dynamics and river flow in determining the distributions of specialist ERS invertebratesHenshall, Sarah Elizabeth January 2011 (has links)
Exposed Riverine Sediments (ERS) are highly dynamic habitats that support large numbers of rare and scarce invertebrates. ERS are characterised by a high diversity of microhabitats and microclimates. The thesis aimed to assess ERS habitats at a micro, patch and reach scale addressing three broad aims (1) to characterise the nature and dynamics of ERS microhabitat through investigating the thermal characteristics of ERS with respect to sediment calibre, depth and distance from the water‟s edge, and so identify the key factors that control variations in surface and subsurface physical habitat spatially and temporally. (2) Establish the physical drivers of invertebrate microspatial distribution (a) investigate the interaction of microhabitat (moisture and temperature) and food availability in determining invertebrate habitat selection, achieved through experimental habitat manipulation and the use of marked beetles. (b) Determining the microspatial distribution of specialist ERS beetles and spiders, and whether different species were significantly spatially aggregated/ separated from each other. Significant positive or negative association with physical ERS habitat characteristics. Identifying if species show a (3) Examine the spatial dynamics of beetle assemblages in relation to patch environmental variables and, assess population stability, persistence, occupancy and synchrony over time in relation to river flow. ERS microhabitats were found to be subject to strong lateral gradients in sediment, temperature and humidity that are amplified in hot dry weather. Specialist ERS beetles and spiders were found to occupy distinct habitats and showed clear spatial zonation in regard to sediment calibre, vegetation and elevation. Distribution of some species was highly variable and responsive to elevated levels humidity and temperature. Microclimate was found to have a greater influence over invertebrate distributions than food availability. The analysis of the long term data set provided evidence that larger and diverse ERS within sample reaches is associated with larger numbers of beetles of conservation value. Cattle trampling and stabilisation through vegetation were identified as having significant deleterious effects on ERS habitat quality. River flow variability, specifically the timing of high flow events was found to potentially have a negative influence on beetle abundance, population stability and persistence. Population synchrony revealed that the UKBAP beetle Perileptus areolatus exhibits little mobility and is highly resilient to inundation. However this makes it more susceptible to reach scale disturbance and a reduction in either habitat availability or quality.
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An investigation into bee assemblage change along an urban-rural gradientFowler, Robert Edward January 2015 (has links)
Urban densification and a rise in human population call for greater investigation into how the urban-rural gradient can influence bees and their pollination services. This thesis aimed to further current knowledge by: (i) sampling bee assemblages along the urban-rural gradient in Birmingham, UK; (ii) increasing documentation of bee traits associated with pollen carryover; (iii) incorporating a trait-based analysis to bee assemblage change along the urban-rural gradient; (iv) testing whether the pollination services along the same gradient varied between land-use types and (v) investigating the provisioning and reproductive success of bees in the urban environment. This thesis supports previous evidence of species-specific variation by urbanisation and shows how trait composition and trait diversity are influenced by bee assemblage change along the urban-rural gradient. However, this recorded assemblage and trait variation appeared not to alter seed-set in Campanula glomerata between urban and rural areas. I also found that nutritional quality could play an important role in provisioning rate in the solitary bee \(Osmia\) \(bicornis\), with greater offspring produced in sites where more protein was found in provisioned pollen in urban areas. Furthermore, the inter-specific variation in pilosity (which could have an important role to play in pollen carryover and subsequent pollination) can be explained by body size and species’ pollen transport adaptation. From this work, I suggest trait based analysis could be a common framework for future studies to measure bee assemblage change between urban and rural areas. Moreover, this research builds on previous work which suggests that particular traits affect pollen transport and subsequent pollination, and that further detailed study could give clues as to how changing bee assemblages could influence pollination.
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City water balance : a new scoping tool for integrated urban water management optionsLast, Ewan W. January 2011 (has links)
Urban water scoping modelling packages are used as tools to inform decision makers of the sustainability of different water management options for a city. Previous scoping models have not taken sufficient account of natural systems in the urban environment and are often limited in terms of the range of indicators used to measure sustainability and the choice of water management options offered. A new modelling package, named City Water Balance, has been developed to address these limitations. It has the capability to assess the sustainability of a variety of water management options, including the sustainable urban drainage systems, in terms of water flow, water quality, whole life cost and life cycle energy for alternative scenarios of future urban land use, population and climate. Application of the modelling package to the City of Birmingham has demonstrated that the modelled components can describe adequately the existing system, giving confidence that it can be used for scoping strategic options for future water supply and wastewater management. The further application of the package to model alternative scenarios through to 2055 for Birmingham has also been undertaken to illustrate its application. The results from the different analyses have shown that medium scale rainwater harvesting and borehole abstraction are predicted to be more sustainable than the conventional centralised supply and that medium scale wastewater recycling would be more cost effective but less energy efficient. The most sustainable strategy was installation of water efficient appliances as there is the potential for large energy savings from reduced indoor usage and consequent water heating requirements.
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Characterisation of particulate matter emissions from cookingAbdullahi, Lami Karimatu January 2017 (has links)
Cooking fume have been found to be a significant component of ambient particulate matter and also to contribute to high concentrations of aerosol indoors. A linkage of individual exposure to cooking emissions with adverse health effects has been found and thus has led to the need for further understand the composition of this source of particulate matter. This study was concerned with gaining further insights into the chemical composition of aerosol generated from typical styles of cooking and the understanding of trends of the formation of particles among different culinary methods. Cooking source profile for African, Chinese, Western and Indian styles was obtained in a specially designed laboratory based kitchen. These profiles were used as input in a Chemical Mass Balance model where ambient data collected in Birmingham, UK were analysed in order to apportion the quantity of organic matter from cooking sources in the location sampled. It was found that cooking generated a significant mass of aerosol with the particle sizes largely within the respirable size range. The Chinese style of cooking was found to generate the highest concentration of particles with PM mass of 21.61µg/m3. The source profile from cooking obtained from the study were found to correlate well with each other with Indian and Western profiles exhibiting the highest correlation. When used for the CMB model runs, these two profiles provided the best output with the model runs apportioning 16% of the Organic Carbon to be from cooking, with traffic, wood smoke and soil debris contributing 44%, 18% and 24% respectively.
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Organic geochemical investigation of sediments in the Japan Sea : tracking paleoceanographic and paleoclimatic changes since the mid-MioceneWittkopp, Frederike January 2017 (has links)
The mid- to late Miocene marks one of the last warm periods of the Neogene, before the descent in to the ice house climate of the late Pliocene and Pleistocene. The mid- to late Miocene climate was long overlooked, but receives increasingly more interest. This study used organic geochemical biomarker distributions and their isotopic signatures in sediment samples from the Japan Sea, recovered during IODP Expedition 346 and ODP Leg 127/128. It was the aim to reconstruct paleoceanographic and paleoclimatic changes over the last 18 Ma. Reconstructed sea surface temperatures revealed declining temperatures since the Mid-Miocene Climatic Optimum, possibly driven by a long-term decline in atmospheric CO2. Reconstructed pCO2 using alkenone paleobarometry, revealed a late Miocene decline from circa 520 μatm to 380 μatm. A decline in this range is required to trigger the onset of the late Miocene C4 plant expansion, which was also fully detected in the sedimentary record from the Japan Sea. Stable isotope analysis of n-alkanes (δD and δ13C) revealed an intensified summer monsoon from 5-3 Ma, which also led to a freshening of surface waters in the Japan Sea. Overall, the Japan Sea is a suitable study area for the late Miocene climate change.
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Firms finance and the weather : the UK weather derivatives marketRandalls, Samuel Cecil January 2006 (has links)
The spectre of climate change is motivating businesses to evaluate the weather sensitivity of their operations and earnings. Persistent changes in day-to-day weather, such as a warmer than average winter, may prove very costly for businesses and since 1997 a new financial market has grown up around the mitigation of these day-to-day weather risks. This weather derivatives market has expanded from being a small US energy product to become a $45.2 billion industry by 2006. In the process this commodification of weather indexes is re-valuing meteorological data, forecasts and expertise, as well as changing the ways in which firms have traditionally considered weather as unmanageable. This thesis presents an empirical examination of the weather derivatives market, particularly focusing upon the UK, drawing upon in-depth interviews with market participants. Setting this within the context of current theories in human geography and science studies, the research also illustrates the material and discursive implications weather derivatives are having not just on firms and meteorology, but also climate change policies.
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Organic matter fluorescence properties of some U.K. fresh and waste watersHudson, Naomi Jane January 2010 (has links)
Organic carbon is ubiquitous throughout the aquatic environment. It is an heterogeneous mixture of compounds, some of which are fluorescent, with allochthonous and autochthonous origins. The most common aquatic fluorophores are humic materials (peaks C and A) from degraded plant matter and protein-like material (peaks T1 and T2) of microbial origin. Spectral fingerprints of aquatic organic matter composition may be visualised on an excitation emission matrix (EEM) on which each fluorophore is identifiable as a characteristic peak. Protein-like fluorescence (T1 and T2) is linked to bacterial activity, sewage treatment process efficiency and therefore organic matter bioavailability but its source and fluorescence response is poorly understood. In comparison, peaks C and A are widely studied and have historically been considered to be old, degraded and stable. In this thesis I investigate the character of surface water and effluent fluorescent organic matter using EEMs. I identify the likely origins and bioavailability of common fluorophores and the applicability of fluorescence as a technique for measuring the polluting potential of organic carbon in waters. I also determine changes in sample character and organic carbon concentration, through responses of the common fluorophores, under different environmental conditions and recommend best practice for sample storage.
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Establishing the environmental risk of metal contaminated river bank sedimentsLynch, Sarah Francesca Lynn January 2015 (has links)
Climate change predictions indicate an increase in the frequency and duration of flood events along with longer dry antecedent conditions , which could alter patterns of trace metal release from contaminated river bank sediments. This study took a laboratory mesocosm approach. Chemical analysis of water and sediment samples allowed the patterns of Pb and Zn release and key mechanisms controlling Pb and Zn mobility to be determined. Trace metal contaminants Pb and Zn were released throughout flooded periods, however the highest concentrations of dissolved Pb were observed at the end of the longest flood period and high concentrations of dissolved Zn were released at the start of a flood. These concentrations were found to exceeded environmental quality standards. Key mechanisms controlling mobility were (i) anglesite solubility control of dissolved Pb, (iii) evaporation, precipitation and dissolution of Zn sulphate salts, (iii) oxidation of galena and sphalerite, (iv) reductive dissolution Mn/ Fe hydroxides and co precipitation/adsorption with Zn. In light of climate change predictions these results indicate future scenarios may include larger or more frequent transient 'pulses' of dissolved Pb and Zn released to river systems. These short lived pollution episodes could act as a significant barrier to achieving the EU Water Framework Directive objectives.
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The assessment of potential impacts of open cast gold mining on the regional groundwater flow system in hard rock environments : with special reference to GhanaSam, Frederick January 2014 (has links)
We consider a simple semi-empirical scoping calculation in conjunction with mathematical models to estimate the radius of impact (Ri) and to determine the circumstances under which gold mines in Ghana are likely to have adverse effect on water levels and volumes in surrounding villages/farms. The approach involves the assessment of local mine geometries, collation and examination of hydraulic conductivity data and the assessment of recharge infiltration rate. Most of the models used with the entire conductivity dataset (Group A) predicted very close radius of impacts to mine with less than few 100m with a median distance of 400m from the mine’s edge. Although it is expected that 25% of cases could reach up to 2km and further if the system was anisotropic. Derogation of water level and volume is more of a problem for Group B and C aquifer systems of higher conductivity values. Model results show that 50% of cases could reach up to 3.6km with a range of 2.7km to 5.1km, and 3km with a range of 2km to 4.6km from mine centre respectively. Nevertheless, Ri could reach 7.6km and further in extreme cases if the system was anisotropic. With regards to Ghana, by constraining conductivity values using water volumes produced by mines in Ghana, and comparing with the model output, it is tentatively suggested that the most likely Ri values are those calculated with the Group B dataset. It should, however, be noted that this results are very sensitive to hydraulic conductivity, and therefore there is the need in Ghana to publish conductivity and volume data to enable suggestions from this work to be confirmed.
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