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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
411

Application of molecular biological techniques to the identification of cyanobacteria

Lu, Weiqun January 1998 (has links)
No description available.
412

Studies of the foods and feeding ecology of wading birds

Greenhalgh, M. E. January 1975 (has links)
In this thesis are described the populations of waders (Aves: Charadrii) occurring on the Ribble Estuary, Lancashire, special reference being made to the eleven species comprising the bulk of the shore wader population. The daily routine of these birds is described including the time spent in feeding. The feeding areas are described together with the foods taken from gut and pellet analysis and direct observation. The distributions of invertebrates, and especially those of major importance as wader food, are described as well as the factors affecting these distributions. Variations in density of prey in relation to O. D., general geography of the estuary, and time of year are included. Depth distribution and variations in prey size are outlined for the main species. Food intake was studied in the eight main waders. Daily intake through the year is described. in relation to energy requirements. Variations of feeding rates with several factors are included. All data are combined to enable calculation of the total biomasses of the main prey taken by waders in the course of a year. These are compared with total minimum annual production of the prey. Future work, including a computer study based on these and extra data, is outlined.
413

Assessment of carbon and nutrient export from a peatland windfarm construction site

Smith, Benjamin Anthony Visocchi January 2016 (has links)
The full extent of a landscape’s resilience to the environmental impact of siting wind-based renewables on peats is currently unknown. This research explores if windfarm construction activities have caused disturbance by investigating; time series of fluvial carbon (C) and nutrient concentrations; constructing aquatic organic C fluxes, before, during and after the windfarm construction period. Additionally, C sequestration rates of peat and nearby lake sediments (Loch Brora) were calculated to provide a historical context to, i) calculated aquatic C fluxes and ii) sediment export from surrounding catchments, considering both a catchment hosting the windfarm construction and one that does not. Furthermore, the effectiveness of a peatland restoration technique, drain-blocking, was assessed as a means of undertaking a whole system approach to assessing the potential impact of the windfarm development, considering how these management strategies can help mitigate potential C losses associated with construction. The research field site was located on the Gordonbush Estate, near Brora, where construction started in July 2010 (the same time this research began) on Scottish and Sothern Energy Renewables (SSER) 35 turbine windfarm. Construction work finished in May 2012 and data collection continued until September 2014. Throughout this period, fieldwork was focussed on storm event sampling (collecting samples for dissolved organic carbon (DOC), particulate organic carbon (POC), total phosphorous (TP), soluble reactive phosphorous (SRP) and total oxidised nitrogen (TON)), collecting peat and lake sediment cores, samples of modern day sediment export and monitoring water table depth in an area where old drainage channels were blocked as part of a peatland restoration initiative. Three river catchments were studied, two affected by windfarm construction activities (GB10 and GB11) and one control site (GB12), DOC concentrations ranged from 1.1 mg l-1 to 48.3 mg l-1, POC from <0.1 mg l-1 to 21.3 mg l-1, TP from <0.5 µg l-1 to 264 µg l-1, SRP from <0.5 µg l-1 to 39 µg l-1 and TON from <1 µg l-1 to 141 µg l-1. These were all within ranges of macronutrient concentrations measured at other northern temperate peatland sites. Comparing macronutrient concentrations between catchments, generally GB10 > GB11 > GB12 for all determinants. Seasonal patterns in fluvial macronutrient concentrations were observed at Gordonbush: summer maxima and winter minima in DOC and TP concentrations and the opposite trend in TON concentrations. SRP data collected indicates a legacy of forest felling in the Bull Burn Plantation has contributed to increased concentration in the Allt Mhuilin river (GB10) compared to the two other catchments, Allt Smeorail (GB11) and Old Town Burn (GB12) where no forest felling occurred during the data collection period. Differences in DOC and TP concentration in Allt Mhuilin compared to other catchments could also be related to forest felling activities but catchment characteristics such as peat coverage may have also influenced results. For all relevant measures of water quality, macronutrient concentrations from Gordonbush shows studied streams consistently achieved “Good” or “High” status throughout the data collection period. Apart from the legacy of forest felling, a discernible impact of windfarm construction was not observed from macronutrient concentration time series. Calculating annual aquatic C fluxes from studied catchments offered a means of assessing potential impact. Various techniques of estimating fluxes were explored but splitting storm event DOC and POC data based on time of year and whether samples were collected on the rising or falling limbs were concluded to give the best estimates. Calculated fluxes ranged from 3 – 38 g C m-2 yr-1 and DOC consistently accounted for ~90% of total aquatic C export. These values were within limits of other C flux based studies from peatlands but the time series constructed at Gordonbush suggested windfarm construction, between July 2010 and May 2012, may have contributed to an increase in aquatic C export from affected catchments during this time, relative to the control site. Long term C sequestration rates from within the Gordonbush estate were 20-25 g C m-2 yr-1, the same magnitude as aquatic organic C fluxes. However, peat C sequestration was shown to be variable over the last ~9000 years since Scottish peatlands became established, with rates ranging from 10-60 g C m-2 yr-1. Controls on this variation are likely climatic with delivery of moisture influenced by the North Atlantic Oscillation (NAO) a key factor. Calculated lake C sequestration also varied over time, 22-82 g C m-2 yr-1 but an inconclusive radiocarbon dating chronology meant historical comparison of C export dynamics between the, C ‘source’, peatland to the, C ‘sink’, lake was unfortunately not possible. Modern day sedimentary export data showed higher sediment yields from windfarm affected catchment than the control site. Physical characteristics varied considerably between the two catchments so although this observation could not definitively be attributed to a direct windfarm impact, it remains a possibility. Whilst studying and quantifying the impact of drain blocking, manual measurements of water table depth (WTD) ranged between -53 cm to +14 cm in dip-wells and -36 cm to +20 cm in automated logging pressure transducers. The response of WTD throughout both data sets indicates meteorological conditions were more influential as a factor controlling peat hydrology across the site compared to topography. Manual measurements from dip-wells shows the drainage channels investigated (~0.5-0.7 m deep and ~0.5 m wide) had the greatest influence on effect WTD 0-2 m from the main channel but no statistically significant difference was detected in mean WTDs measurements before or after blocking, in relation to distance from the drainage channels themselves or comparisons between drained and un-drained (control) areas. However, data from PTs indicate the net effect of multiple parallel drains can cause water table drawdown at a significant distance, ~ 25 m, from the drainage channel. This is an important finding as methodology used to calculate the C ‘payback time’ of windfarms utilises the lateral drainage extent of peat when turbines bases are excavated. Drain blocking had no obvious effect (either positive or negative) on WTDs however it is acknowledged positive effects can take up to five years, after blocking has taken place, to be observed. Maximum DOC concentrations increased the year after blocking however this result has been recorded at other sites and the exceptionally dry summer of 2013 could have contributed to the noticed increased by promoting more peat oxidation and subsequently DOC production. There was no statistically significant difference between [DOC] collected up and downstream of the drainage channel inputs for samples collected before and after blocking. This suggests drain-blocking has had little impact on the larger site [DOC] signature one year after drain-blocking. However, as discharge from drainage channels was not measured, a potential reduction in overall DOC export could not be fully assessed and this is a highlighted future research need. Combining averages of aquatic organic C fluxes and peat C sequestration rates calculated it is estimated net ecosystem exchange would have to be between -30 to -50 g C m-2 yr-1 for Gordonbush to be classed as a C ‘sink’. If the observed increases in sedimentary export could be attributed to windfarm construction, Loch Brora is unlikely to act as a strong C sink for any potential increased losses as it is estimated ~90% of POC exported is not sequestered on a long-term basis in the lake sediments. It has recently been recommended windfarms should not be developed on peatlands due to the marginal C savings achieved as our future energy mix changes (Smith et al., 2014). However, if similar projects are granted planning permission then findings from this research support the following recommendations: installation of buffer zones around areas of felled forestry to reduce nutrient export into surrounding streams; implementation of a water quality monitoring programme to assess impact of windfarm construction during construction and a period afterwards as it is still unclear from this research if there will be any lasting effects; installation of silt traps to reduce aquatic sediment export and disturbance; limit any high density excavation of drainage channels as the effects of water draw-down could be quite extensive; in addition, blocking all historical drainage channels and retaining as much moisture as possible within, and surrounding, areas of degraded peatland can increase long-term peat C sequestration rates and offset C losses experienced during construction. This research has been funded by SSER, Engineering and Physical Sciences Research Council (EPSRC) and Energy Technology Partnership (ETP). This research has been undertaken and supported at the University of Glasgow within the College of Science and Engineering, specifically aligned to the work of the Carbon Landscapes and Drainage (CLAD) research group headed by Prof. Susan Waldron in the School of Geographical and Earth Sciences. Finally, this research has also been supported in partnership with Stirling University.
414

The environmental geochemistry of trace-metal contaminants in the urban area of Glasgow

Gibson, Martin John January 1984 (has links)
No description available.
415

An ecological and experimental study of sediment-benthos interactions in a polluted estuary

Abdula, Samira Abdul-Hussain Abdula January 1985 (has links)
No description available.
416

Corporate environmental management of private businesses in Saudi Arabia

Magbool, Samia S. January 2009 (has links)
The implementation of corporate environmental management system has become an essential part of running any business to attempt to achieve sustainable development. No previous studies in Saudi Arabia have been conducted to explore the use of environmental management systems. The objective of this thesis was to investigate the attitudes and levels of awareness of business managers towards their companies' environmental practices and to determine how far private Saudi companies are taking up environmental management. Different factors like the demographic features of the private Saudi companies, some important drivers and barriers that affect the levels of taking up corporate environmental policies and practices were explored and discussed. Two studies, qualitative and quantitative studies, were conducted to bridge this gap of knowledge. The survey method was used for the quantitative study (N=176), while a semi-structured interview was developed to run the qualitative study for a sample of 18 representatives from six companies to confirm and elaborate on the findings of the quantitative study. The results of these two studies showed that some demographic features of the company may have an effect on the uptake of CEM. It also showed the significance of a number of themes (i.e. environmental initiatives, organizational support, environmental operations, and environmental responsibility) in the uptake of sound environmental practices and procedures. The study also classified Saudi Arabian companies, according to the perception of their employees, in terms of their level of environmental performance into three categories; the Inactive/unaware, the Concerned-inactive, and Potentially proactive (ICP). Most of the companies investigated fell in the first category (51%) and second (27%) category which indicates that Saudi Arabia is still to begin developing in this area. Overall, the perceived level of the CEM performance of Saudi private companies is low due to the lack of enforcement of environmental laws, the philosophy of top management, the absence of environmental protection societies and an organizational structure in companies that does not support implementation of an EMS.
417

The transfer, storage and release of water colour in a reservoired catchment

Pattinson, Victoria A. January 1994 (has links)
In recent years discoloured water has become a matter of growing concern to water resource managers. Discoloured water is a major source of consumer complaints and is expensive in capital and recurrent costs. The treatment of water discolouration is believed to be associated with a number of health issues, such as Alzheimer's disease. In particular, discoloured water, upon chlorination, is believed to produce carcinogens. The principal aim of this research has been to consider and manage water colour within an entire reservoir catchment system; Thornton Moor Reservoir, the study area, has experienced some of the highest values of colour in the Yorkshire Water Region, and has been an area of significant concern and cost to Yorkshire Water Services. Apparently homogenous subcatchments can produce marked differences in the colour of runoff data. This research has involved an investigation into the relationship between the subcatchment tributary water colour and catchment morphology. The relationships established were used to generate a predictive model for water colour such that areas of high water colour could be identified without intensive sampling. The initial phase of this study considered the transfer network involved in bringing the colour from the catchment to the reservoir. This has involved an analysis of the spatial and temporal variation of water discolouration within the catchment. The consistency of the spatial variation of water colour between the tributaries has been utilised to develop a management protocol which is presently being implemented at Thornton Moor in order to minimise the level of discolouration, whilst maintaining water supplies. Edwards (1987), describes the reservoir as the second line of defence in the protection of water supplies in direct supply reservoirs. No research to date has considered the role of the reservoir in the storage, transmission and release of discoloured water. Empirical evidence at Thornton Moor Reservoir suggests that for the majority of the year, the reservoir operates as a buffer to colour; however at certain times of the year it appears actively to increase the colour entering the treatment works. In considering the entire catchment system, it has been possible to develop a transferable staged approach to catchment management.
418

Biodegradation and settlement behaviour of mechanically biologically treated (MBT) waste

Siddiqui, Asif Ali January 2011 (has links)
No description available.
419

Mixed herbivore grazing on a lowland heath system : quantifying the collective impacts for conservation management

Wilkie, Martin January 2013 (has links)
Degradation of terrestrial habitats with high conservation value has resulted in strategic efforts to cease or reverse their declines. Broad habitat management can restore ecological processes and large herbivores can provide ecological function in some terrestrial systems. Following years of decline and fragmentation, owing to factors such as cessation of traditional practices, lowland heathland has become an internationally important habitat with strategic protection. Free-ranging grazing aims to assist in mitigating such losses to habitat and vegetation communities, but quantifying the grazing regime and its associated impacts is necessary to ensure protection of these vulnerable systems. Reviews of herbivore impacts on lowland heath provide detailed evaluations and recognise the absence of experimental assessments and baseline monitoring. This research aimed to assess ecological activity and impacts (herbage removal, trampling and dunging) of horses and cattle on a lowland heath system to determine their influence on changing vegetation and to inform grazing management. This mixed regime is commonly adopted for restoration of semi-natural habitats but a failure to understand the separate vegetation impacts can be detrimental for the system as a whole. Behavioural activity was quantified using scan-sampling assessing spatial and temporal variation in behaviour, habitat selection and niche overlap, spatial occupancy and diet. A factorial design was set up to quantify the impacts of herbage removal, trampling and dunging to vegetation separately. Assessments vegetation community composition and architecture in treatment and control areas were undertaken. Analyses incorporated non-parametric and general linear models. Animals utilised their environments in different ways, varying for feeding and showed high habitat selectivity, based on physiology and foraging strategy primarily. Herbage removal strongly influenced vegetation architecture and heterogeneity owing to selection for graminoids and the plants’ competitive traits; effects on other plants were not as well defined due to minimal abundance. Trampling modified the vegetation structure due to reduced canopy density maintaining colonising gaps, but increased graminaceous cover and showed a capacity for lateral expansion. Dunging regime was highly influential for enhancing plant architecture and modified vegetation composition based on nutrient availability and competition. Worming regime was influential on architectural parameters and may be due to retarded dung degradation; further research is required. The findings contributed knowledge to lowland heath grazing management, validating the use of mixed regimes at low densities, for generating vegetation heterogeneity, for the control of dominating plants and for understanding the impacts of different animal-management practices. Expanding the reach of this research to comparable systems is necessary to develop the knowledge of grazing-management impacts. The work addressed an absence of experimental evaluation on these systems and also illustrated the importance of separately quantifying the impacts of large herbivores.
420

Variations in carbon emissions from vehicles at signalised intersections

Ing, Koh January 2011 (has links)
Carbon emissions from road transport make up 20% of the total greenhouse gas emissions in the UK. Therefore, reducing carbon emissions from road transport is significant in reaching carbon reduction targets. In urban areas where signal controlled intersections are common, carbon emissions from vehicular traffic can be aggravated by aggressive driving and interruptions induced by traffic control. Considerable variations in speed and acceleration profiles could be observed between high carbon and low carbon driving. In view of the immediate effects that changing driving behaviour could have on carbon emissions without extra cost, this study had investigated the variations in carbon emissions at signalised intersection, which includes the scale of impacts of changing driving behaviour and flow interruption on carbon emissions. Characteristics which lead to high CO2 emissions could then be modified by addressing the behavioural change and control strategies. High frequency real world driving data was collected using the TRG highly instrumented vehicle. The vehicle was equipped with a number of on-board systems, i.e., on-board emission measurement system, velocity box, on-board diagnostic unit, Dashdyno and video recorder. Aggressive and economical driving styles observed for two drivers during initial tests showed distinct differences in terms of speed profiles and fuel consumption. These initial tests were used to examine the nature and scale of potential impacts on fuel consumption and to design main field tests. Natural driving observed from twenty nine drivers from the main field tests also showed significantly different levels of carbon emissions at signalised intersections, which were caused by variations in both driving behaviour and traffic control. In terms of driving behaviour, changing the worst driving to the best driving during interrupted driving was found to reduce CO2 emissions significantly. The carbon reductions were collectively contributed by 1) applying soft acceleration and keeping acceleration below 0.6m/s2 during the acceleration mode and 2) reducing leaving speed at intersections, 3) practising smooth deceleration and stable speed during the deceleration mode and 4) applying the idle-stop system. Carbon emission rates of different vehicles may vary from one to another. However, it was found that the amount of carbon savings demonstrated in this study could be possibly achieved by other internal combustion vehicles of the same class, and by hybrid electric vehicles to a lesser extent. In this study, changing driving behaviour is recommended as a cost effective way to achieve carbon reduction.

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