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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.
1

Organic geochemistry applied to petroleum source potential and tectonic history of the Inner Moray Firth Basin

Duncan, Alasdair D. January 1986 (has links)
Upper Jurassic sediments from the Inner Moray Basin have been analysed using a variety of organic geochemical techniques. Shales belonging to the Kimmeridge Clay and Heather/Brora Formations may be readily distinguished using molecular parameters, bulk geochemical data and the results of transmitted light kerogen microscopy. Oxfordian sediments are characteristically more organic lean and sulphur poor than their ?Volgian - Kimmeridgian counterparts; they also contain a more significant terrestrially derived organic matter component. Lipid fractions in the remainder of the succession are typically dominated by the products of marine algal phytoplankton and bacteria. Detailed investigation of the distribution of biological marker compounds indicates that the nuclear demethylated hopanes are confined exclusively to sediments of ?Volgian - Kimmeridgian age in this basin. This feature, together with other more subtle, non-source specific variations may be attributed to a decrease in the dissolved oxygen content of the water column throughout the Upper Jurassic. All maturity measurements concur that in this region the Upper Jurassic sediments are insufficiently mature to have generated or expelled significant volumes of petroleum at any stage throughout their geological history. A range of maturities is nevertheless recognized which permits a ranking of the individual wells, and indicates that shales overlying the Beatrice reservoir have experienced the greatest thermal stress. A marked discrepancy in the maturities of contemporaneous sediments from two groups of wells presently at the same burial depth, has also been identified. This is largely consistent with the observed variation in geothermal gradients and the distribution of Kimmeridgian sands across the basin. Kinetic modelling using the biological marker maturity parameters has established that in the west 1km of sediment has been removed following Tertiary inversion of the basin. Results indicate that in the east, a figure of 700-800m is more appropriate. Potential source rock lithologies from the margins of the basin have also been examined. These included the Jurassic sediments in the Helmsdale outlier and Middle Devonian lacustrine laminites from Caithness. A Middle Devonian component to the Beatrice crude is strongly suggested by the similarity of their steroid alkane distributions.
2

The Neo-Firthian tradition and its contribution to general linguistics /

Monaghan, James. January 1979 (has links)
Texte remanié de: Dissertation--Linguistics--Frankfurt am Main. 1978. / Bibliogr. p. 213-223. Index.
3

Population dynamics, biology and ecology of the caridean shrimps : Crangon crangon Linnaeus, Crangon allmanni Kinahan and Pandalus montagui leach in the estuary and Firth of Forth, Scotland

Jayamanne, Sepalika Chandrani January 1995 (has links)
The population of shrimps from five stations in the estuary and one station in Firth of Forth were sampled for two years from January 1992 to investigate their population dynamics, reproductive biology and feeding ecology. Sampling was carried out at high water and low water, six times a year, by towing an Agassiz trawl, with the Forth River Purification Boards' research vessel, the 'Forth Ranger'. Two residents, Crangon crangon and Pandalus montagui, and a migrant species, Crangon ailmanni, were identified as the main three species of shrimps in the estuary and Firth of Forth. C. crangon was found throughout the estuary while P. montagui was confined to the lower reaches of the estuary. C. alimanni appeared in the estuary in October and left by June. In the Firth of Forth, P. montagui and C. alimanni were the dominant species. The breeding cycle commenced in October, and berried females were found by December/January for all species. Berried females of P. montagui, and both male and female C. alimanni, migrated from the estuary to deeper areas, never to return. C. crangon females with eggs ready to hatch, spent females and larvae all occurred in the estuary. The larvae were present in the estuary from April to October. Larvae of the other two species were not found in the estuary. All species fed mainly on polychaetes, followed by bivalves and crustaceans, which indicated a benthophagous feeding habit. The choice of food depended on the local availability of prey items, and the range of the particular shrimp species within the area; shrimps fed on prey which was abundant in their area of residence rather than moving elsewhere. The Forth Estuary is well utilized by the three species with little competition between them. Although a slow growth rate was observed in C. crangon, the mean condition factor indicated that the conditions in the Forth estuary were close to those normally required for shrimps. The Forth estuary shelters three species of shrimps, with populations, varying between 1992 and 1993, of 1.6-7.7 x 107 for C. crangon, 1.6-2.5 x 107 for P. montagui and 0.7-1.0 x 107 for C. alimanni. These three species contributed to the total annual shrimp production, which ranged from 5.59-17.93 tons at low water in the ratio 40:14:1. Both resident and migratory fish species benefit from this production because shrimps play a key role in the food web, forming the major link between the lower benthic invertebrates and predatory fish.
4

The trade-off between starvation and predation risk in overwintering redshanks (Tringa totanus) /

Sansom, Alex. January 2010 (has links)
Thesis (Ph.D.) - University of St Andrews, February 2010.
5

Investigations into zooplankton assemblages off the west coast of Scotland

Richard, Jocelyn M. January 1992 (has links)
Zooplankton assemblages were examined from waters off the west coast of Scotland encompassing the Firths of Lorn and Clyde, the North Channel, and the Malin Shelf. Size fractionated samples (coarse, >1000μm; medium, 1000μm-330μm; fine, 330μm-180μm) were collected with a submersible pump from 10m and 30m depth in March (1987) and May (1986) providing a composite picture of the fauna in early and late spring conditions, respectively. The feasibility of using image analysis as a method for processing zooplankton samples was examined. Although a programme was successfully operated to obtain individual measurement data, much work is still required before a fully automated programme for routine use by planktologists is available. Total zooplankton numbers and biomass, and species distributions and relative abundances were examined. Species assemblages were identified using multivariate analyses. Biomass and abundance spectra by size were examined for the major station groupings. In general, meroplankton dominated the fauna in the Firth of Lorn while large numbers of Calanus spp. occurred in the Firth of Clyde. Small copepods such as Oithona spp. were characteristic of the assemblage on the Malin Shelf. Salinity, followed by temperature, showed the strongest association with the observed station clusters. Chlorophyll a and depth did not generally appear to influence station groupings. The potential for the mixing and exchange of zooplankton between the regions of the study area was evaluated. The results suggest that zooplankton may be entrained from the Firth of Clyde by the Scottish Coastal Current during the spring period. The Malin Shelf may also be an important source of zooplankton for the Firth of Lorn during winter months when an onshore flow of Atlantic water occurs.
6

The fish populations of the Lower Forth Estuary, including the environmental impact of cooling water extraction

Greenwood, M. F. D. January 2001 (has links)
The present study investigated the fish populations of the lower Forth Estuary, east Scotland. Cooling water extraction by the 2400 MW Longannet Power Station (LPS) inevitably removes a certain quantity of fish from the estuary, all of which experience mortality. The present study employed a sampling regime of greater intensity than previous studies to investigate the extent of mortalities from January 1999 - December 2000. Collections of fish impinged on intake screens were made eight times monthly, at LW or HW of spring or neap tides during the day or by night. Marine species dominated the assemblage of fish collected, with sprat, herring, and whiting contributing > 80% of total abundance. Sprat was twice as abundant as herring in 1999, while the proportions were very similar in 2000. Total abundance of all species collected in 1999 was estimated at 1. 09 x 107, while the value of 3.29 x 107 in 2000 was three times larger. These figures were the largest recorded among British estuarine and marine power stations, but were precisely the correct order based on an exponential relationship between total impingement and water abstraction rate established from data from other locations. Validation of the estimated total biomass of fish removed was given by comparison with the known total mass of all materials disposed to landfill. Statistical analysis of impingement data showed that tidal range and season were the most important environmental variables influencing the rate of removal of fish from the estuary. That light was not significant for most species is attributed to high levels of turbidity and the resulting low visibility by day and night. Demersal and benthic fish abundances collected from 1982 - 2000 in 30 annual trawls at three sites in the mid-lower Forth Estuary were analysed. Species tended to be present in greatest abundance at the most seaward of the sites. Patterns of seasonal abundance reflected those observed in the impingement study at LPS, and catches tended to be greatest at L W. Total species richness showed no significant trend over time, whilst total annual abundance of fish captured in trawls showed a significant negative trend. This was largely due to significant declines in the two most abundant species, namely whiting and eel pout, attributable in the latter case to increasing temperatures. Changes in the ichthyofaunal composition were largely driven by whiting, eel pout, cod and plaice. Eight of ten common species showed no significant trend in abundance over the length of the time series, suggesting them to perhaps be at equilibrium densities. Quantities of commercially fished species above minimum landing size limits that were removed by LPS were very low, and restricted to herring and occasional whiting. The quantity of juveniles that could have recruited into the fished populations was expressed as equivalent adults. The values were larger than any previously reported in the UK, primarily due to the quantities of juvenile fish impinged being greater than at any other British power station, and the importance of the Forth as a nursery area for marine species. It was concluded that LPS is the dominant UK power station in terms of magnitude of impingement losses. It may be prudent to consider a precautionary approach to mitigate losses, and to this end options for reduction of the magnitude of impingement are discussed.
7

The trade-off between starvation and predation risk in overwintering redshanks (Tringa totanus)

Sansom, Alex January 2010 (has links)
In order to meet their energy budget animals must often increase their risk of predation, either through their choice of foraging location or by decreasing anti-predation behaviours, which are incompatible with foraging. I investigated the starvation-predation risk trade-off in redshanks overwintering in the area of the Firth of Forth in Scotland over different spatial scales. On a small spatial scale, where redshanks foraged in an area where risk of attack was high I investigated the role of competition for food and decreased individual vigilance within groups and how this related to predation risk, additionally I looked at the relative roles of individual variation in time spent exposed to risk and variation in anti-predation behaviours on individual survival time. On larger spatial scales of 100s of meters and over several kilometres, I considered how choice of overwintering site was affected by predation risk, profitability and population density. Time available to feed increased with increased group size, allowing redshanks to compensate for increased competition and allowing large groups to form, thus decreasing individual predation risk. Individuals that spent less time exposed to attacking predators survived for longer, however individuals constrained by cold weather to spend long periods exposed to risk could increase their survival through increased intake rates and vigilance. On an intermediate spatial scale redshanks selected overwintering sites based on profitability rather than risk, and only used less profitable site when population density was high. On a large spatial scale redshanks increased their use of less profitable sites in warmer weather, but did this without increasing their risk of predation. Overall this suggests that across most spatial scales redshanks can minimise their predation risk by their choice of foraging location, but when forced by weather conditions or competition to be exposed to attack, capture reducing behaviours also reduce predation risk.
8

Die entwicklung des britischen Kontextualismus /

Steiner, Erich H. January 1983 (has links)
Diss.--philosophische Fakultät--Saarbrücken, 1982. / Bibliogr. p. 385-439. Index.
9

Public choice for flood defence

Simpson, Katherine Hannah January 2015 (has links)
Why do we want to value the environment? Environmental assets provide a flow of goods and services over time which benefit mankind. Valuing these services contributes towards their protection and enhancement, however many of these benefits cannot be valued in traditional markets and as such rely on non-market valuation techniques. One of these is contingent valuation (CV) which directly asks respondents whether they are willing to pay for an improvement in the good or service. This thesis seeks to explore methodological issues associated with this method by undertaking a CV survey to elicit willingness to pay (WTP) for a new type of flood defence (managed realignment) on the Tay Estuary, Scotland. One challenge for survey designers is to provide high quality, readily understandable information to mitigate bias in WTP estimates. This thesis contributes to the information provision literature by examining whether prior knowledge or new information has a greater effect on the WTP estimate when controlling for respondent experience and familiarity with the good. A field experiment was designed to test for respondent’s prior knowledge; allow for varying levels of information to be presented to respondents and identify information acquisition for each respondent. Specifically tested was the notion that respondents who learn the most about the good during the survey process will have a more robust WTP estimate. Results were mixed: a causal relationship between information provision and learning was established with respondents in the higher treatment groups scoring higher in the second quiz. However, there was no relationship identified between prior knowledge, information provision and WTP. Personal motivations were the strongest predictors of WTP: those who were most concerned about flood risk and who lived closest to the proposed flood defence were willing to pay the most. A second issue in CV is consequentiality. Carson and Groves (2007) argue that for a survey to produce meaningful information about respondent’s preferences the respondent must view their responses as potentially influencing the supply of the public good. This thesis seeks add to this relatively new literature by exploring the observable factors which may influence respondents perceived consequentiality; specifically the effects of familiarity and information. Respondents were asked to state how confident they were that the results of the survey would be used by policy makers on a Likert scale ranging from “very unconfident” through to “very confident”. Results conformed to the Carson and Groves knife edge result: consequential respondents had significantly different WTP distributions compared to inconsequential and unsure respondents and were willing to pay significantly more towards the scheme. Consequential respondents also conformed the theoretical considerations of construct validity whilst inconsequential respondents did not. Respondents with more prior knowledge also appeared to be more likely to perceive the survey as consequential, although this was not consistent across all treatment groups. There is a concern that WTP and consequentiality are endogenous: respondents who want the policy to go ahead may be more likely to state the survey is consequential and state a high WTP in the hope these responses combined contribute to the policy maker’s decision. From a policy perspective the high level of support for the new scheme was encouraging and in contrast to previous findings on preferences for managed realignment. From a flood risk management perspective a “miss-match” between actual and perceived flood risk was highlighted, with many respondents stating they were not at risk from flooding when they in fact were. This is potentially concerning as respondents may not be taking adequate steps to protect their home from future flood risks. Overall it is recognised that values derived from the CV survey form one small part of the planning process and while informative, the decision for a scheme to take place should not be based on these values alone.
10

The restoration of intertidal habitats for non-breeding waterbirds through breached managed realignment

Crowther, Amy E. January 2007 (has links)
Conservation of intertidal habitats in the UK is vital in order to continue to support nationally and internationally important populations of non-breeding waterbirds. Historic reclamation for agriculture and industry has resulted in the loss and degradation of large areas of these intertidal habitats in estuaries and they continue to be threatened by sea-level rise. Managed realignment is one method which is increasingly being used to restore intertidal habitats. As managed realignment is a relatively new restoration technique, the extent to which knowledge of the biology of estuaries is applicable to managed realignment sites is unclear. Habitat restoration is often unsuccessful or incomplete, so a detailed knowledge of both the natural system and the characteristics of restored systems will usually be necessary to recreate fully-functional estuarine habitats. This thesis focuses on Nigg Bay Managed Realignment Site (Nigg Bay MRS), the first managed realignment site in Scotland, and follows the first four years of ecological development to gain an understanding of how breached realignment can be used to restore intertidal habitats to support non-breeding waterbirds. This thesis has six major aims: (i) to describe the development of saltmarsh, (ii) to describe the development of intertidal flat, (iii) to describe the colonisation by non-breeding waterbirds (iv) to determine how tidal cycle and weather affect patterns of waterbird use, (v) to determine which factors affect the spatial distribution of waders and finally (vi) to determine the patterns of use by individual birds. Four summers after the re-establishment of tidal conditions, almost all of the saltmarsh species recorded on the nearby saltmarsh had colonised Nigg Bay MRS, although recognisable communities had yet to establish. Three winters after the re- establishment of tidal conditions in Nigg Bay MRS, the sediments had a significantly smaller particle size and higher organic matter content compared to the fine sands of the adjacent intertidal flats. The intertidal invertebrate community also differed from the adjacent intertidal flats. Nigg Bay MRS attracted large numbers of non-breeding waterbirds and supported each of the most common wader and wildfowl species present in the wider estuary. Nigg Bay MRS performs a number of important functions for non-breeding waterbirds by: (i) providing a foraging and resting habitat when the tide is absent and intertidal sediments in Nigg Bay are exposed; (ii) providing a foraging resource as the tide passes over the intertidal sediments within the site once the intertidal flats in Nigg Bay are inundated; and (iii) providing a high tide roosting site. On days with low temperatures and high wind speeds, more waterbirds use Nigg Bay MRS, suggesting that it is likely to be providing sheltering benefits. Nigg Bay MRS also provides top-up feeding habitat. The factors that often influence the spatial distributions of waders in estuaries appear to be operating within Nigg Bay MRS. Wader densities are greater on the intertidal flats when they are accessible than on the saltmarsh. Wader densities are also greatest close to creeks and drainage channels, possibly due to higher invertebrate densities, more accessible prey or sheltering benefits. Colour-ringing and radio-tracking of Common Redshank established that Nigg Bay MRS has a subset of regular users, including both adults and juveniles, and the wader assemblage at night may differ from the assemblage during the day. These findings are discussed in terms of the implications for locating, designing and managing future managed realignment projects.

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