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Investigation, Development And Application Of Knowledge Based Digital Signal Processing Methods For Enhancing Human Eegs, Mark Tremaine Hellyar Jan 1991

Investigation, Development And Application Of Knowledge Based Digital Signal Processing Methods For Enhancing Human Eegs, Mark Tremaine Hellyar

School of Engineering, Computing and Mathematics Theses

This thesis details the development of new and reliable techniques for enhancing the human Electroencephalogram {EEGI. This development has involved the incorporation of adaptive signal processing (ASP) techniques, within an artificial intelligence (Al) paradigm, more closely matching the implicit signal analysis capabilities of the EEG expert. The need for EEG enhancement, by removal of ocular artefact (OA) , is widely recognised. However, conventional ASP techniques for OA removal fail to differentiate between OAs and some abnormal cerebral waveforms, such as frontal slow waves. OA removal often results in the corruption of these diagnostically important cerebral waveforms. However, the experienced EEG …

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Automated Cold Vapour Flow-Injection Analysis Of Mercury At High Concentrations, Wt Corns, Lc Ebdon, Sj Hill, Pb Stockwell Jan 1991

Automated Cold Vapour Flow-Injection Analysis Of Mercury At High Concentrations, Wt Corns, Lc Ebdon, Sj Hill, Pb Stockwell

School of Geography, Earth and Environmental Sciences

Continuous-flow cold vapour- atomic fluorescence spectrometry is shown to be an extremely sensitive technique for the determination of mercury with detection limits typically below 0.01 μg l-1. Linear calibration ranges were found to be at least four orders of magnitude (i.e. up to 0.1 mg l-1). Samples with concentrations exceeding the linear range are susceptible to self-absorption, and may, in severe cases, cause carry-over problems between samples. The flow-injection approach has been utilized to extend the upper limit of the linear calibration range allowing determinations up to 10 mg l-1 of mercury. A range of certified reference materials and zinc …

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Wave Overtopping: A Comparison Of Physical And Numerical Studies, Gary John Murton Jan 1991

Wave Overtopping: A Comparison Of Physical And Numerical Studies, Gary John Murton

School of Engineering, Computing and Mathematics Theses

The overtopping of low-crested breakwater is investigated by means of hydraulic and mathematical models. A conventional laboratory wavemaker with a wedge-type paddle is converted into an absorbing wavemaker so that it can be used to investigate accurately wave overtopping of reflective coastal structures. The absorption system is achieved by use of a feedback loop added to the control circuit. The design criteria and implementation of the circuit are presented in detail. Enhanced control software is used to generate different 'random' sea states with the same statistical properties. The absorption system is validated by ail extensive series of tests made possible …

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On-Line Analyte Preconcentration With Atomic Spectrometric Detection., L. Ebdon, A. S. Fisher, S. J. Hill, P. J. Worsfold Jan 1991

On-Line Analyte Preconcentration With Atomic Spectrometric Detection., L. Ebdon, A. S. Fisher, S. J. Hill, P. J. Worsfold

School of Geography, Earth and Environmental Sciences

Pre-concentration of analytes, or matrix removal to overcome interferences using mini- or micro-columns of exchange media prior to atomic spectrometric detection is becoming increasingly more common. This paper is a review of some of the more recent applications of chelating, ion exchange and other resins and gels that have been used to accomplish this.

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An Investigation Into The Perceived Urgency Of Auditory Warnings, Elizabeth Jane Hellier Jan 1991

An Investigation Into The Perceived Urgency Of Auditory Warnings, Elizabeth Jane Hellier

School of Psychology Theses

This thesis considers the perceived urgency of sound, with specific reference to auditory warning design. Psychophysical techniques were investigated as a means of measuring perceived urgency. The biases inherent in different techniques were reviewed. Free modulus magnitude estimation, fixed modulus magnitude estimation, category estimation and cross modality matching were used to scale perceived urgency. On the basis of the cross modality matching validation procedure It was recommended that free modulus magnitude estimation or cross modality matching were used to measure perceived urgency. The successful application of psychophysical techniques meant that the relationship between perceived urgency and objective changes in sound …

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Slurry Atomisation Using Mixed Gas Plasmas, Phillip Stephen Goodall Jan 1991

Slurry Atomisation Using Mixed Gas Plasmas, Phillip Stephen Goodall

School of Geography, Earth and Environmental Sciences Theses

The use of molecular gas addition as volatilisation aids in slurry nebulisation inductively coupled plasma atomic emission spectrometry (SN-ICP-AES) has been investigated using a combination of rigorous optimisation strategies and spectrochemical measurements. Three gases were studied, nitrogen, hexafluorethane (Freon 116) and hydrogen. Nitrogen addition did not appear to offer any benefits in terms of improved accuracy of SN-ICP-AES, whilst the introduction of Freon 116 was notable for some unusual plasma chemistry.

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Estuaries As Sources Of Methylated Arsenic To The North Sea, Heather Jane Kitts Jan 1991

Estuaries As Sources Of Methylated Arsenic To The North Sea, Heather Jane Kitts

School of Geography, Earth and Environmental Sciences Theses

Analytical techniques were developed for the detection of inorganic arsenic (As(III) and As(V)), monomethylarsenic (MMA) and dimethylarsenic (DMA) in water, pore waters, suspended particles and bed sediments of the Humber Estuary, Thames Estuary and the southern North Sea. Dissolved inorganic As in the Humber Estuary showed removal in the mouth of the estuary in association with an Fe-rich outfall. Intertidal sediments and suspended particles had elevated inorganic As concentrations in the vicinity of the As-rich outfall located in the low salinity zone. Particulate As had a distinct concentration gradient away from the estuary mouth, indicating the transport of As out …

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The Late Quaternary History Of The River Erme, South Devon, Susan Creak Jan 1991

The Late Quaternary History Of The River Erme, South Devon, Susan Creak

School of Geography, Earth and Environmental Sciences Theses

This thesis examines a typical 'drowned* river valley of south-west England. The River Erme drains southern Dartmoor and, in common, with other rivers of the region, has a buried channel graded to c. -50m OD. The channel has been infilled with a variety of sediments, of which the top 6-7m have been analysed for this study. Augered cores have been collected from the modern floodplain and salt marsh areas in the lower part of the valley and have been studied using particle size, diatom, molluscan and radiocarbon analyses. The main sediment types recovered include a fine silt unit representing the …

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Studies Of Sediments In A Tidal Environment, Fiona Fitzpatrick Jan 1991

Studies Of Sediments In A Tidal Environment, Fiona Fitzpatrick

School of Geography, Earth and Environmental Sciences Theses

Five sedimentary environments in Plymouth Sound, S.W. England, are defined by side-scan sonar surveys calibrated by direct sampling by SCUBA divers: (i) uniform mud depocentres, (ii) areas of continual sediment reworking, (iii) areas of relict sedimentation, (iv) areas of episodic deposition and, (v) clean-washed rock outcrops. Net sediment transport paths are defined using the physical properties of the sediment. Analysis of Airborne Thematic Mapper and Compact Airborne Spectographic Imager scanner data at High and Low Water, with concurrent sampling has enabled the relationship to be established between suspended sediment concentration, percentage organics, temperature and salinity and a marked continuity between …

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The Sedimentology, Petrology And Stratigraphy Of The Upper Greensand In S.W. England, Colin L. Williams Jan 1991

The Sedimentology, Petrology And Stratigraphy Of The Upper Greensand In S.W. England, Colin L. Williams

School of Geography, Earth and Environmental Sciences Theses

A new lithostratigraphic scheme is proposed for those deposits formerly known as the Upper Greensand. In the south and south-west of England the proposed Selbome Group is made up of the proposed Wessex Greensand Formation and Gault Clay Formation as well as the existing Haldon Sands Formation. Four members are proposed and type sections are designated. Lithological logs are presented for sections at Branscombe/Beer Head (Type Section for the Foxmould Sands Member and the Chert Beds Member); Kempstone Rocks, Dunscombe, S.E. Devon (Type Section for the Top Sandstones Member); Whitecliff, Seaton, S.E. Devon; and a small quarry at Dunscombe, S.E. …

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Reactive Gases In Electrothermal Atomisation Atomic Absorption Spectrometry, Andrew Fisher Jan 1991

Reactive Gases In Electrothermal Atomisation Atomic Absorption Spectrometry, Andrew Fisher

School of Geography, Earth and Environmental Sciences Theses

A variety of gases and vapours of organic compounds have been used as matrix modifiers in electrothermal atomic absorption spectroscopy (ETAAS). Oxidising gases such as air or nitrous-oxide, introduced during the charring stage, both thermally stabilised analytes such as lead, and improved the efficiency of pyrolysis by converting the normal charring into an ashing step. A number of interferences eg. magnesium chloride on lead determinations and non-specific absorbance interferences, decreased when air was introduced. Hydrocarbon gases (< 5% v/v) introduced during charring improved sensitivity (up to 89%) for certain refractory analytes (eg. Al, Ca, Mg, Si and V), prolonged tube life and improved precision.

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New Approaches To Automated Analytical Instrumentation, Warren Thomas Corns Jan 1991

New Approaches To Automated Analytical Instrumentation, Warren Thomas Corns

School of Geography, Earth and Environmental Sciences Theses

The development, optimisation and assessment of novel automated analytical equipment for cold vapour/hydride generation is described. Various designs of gas-liquid separators (GLS) were investigated for continuous flow hydride generation, including a glass 'U' tube GLS, a silicone rubber membrane GLS and a microporous polytetrafluoroethylene membrane GLS.

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Foraminiferal Biostratigraphy And Palaeoecology Of The Albian To Santonian (Cretaceous) Of Bornholm, Denmark, Stephen Ronald Packer Jan 1991

Foraminiferal Biostratigraphy And Palaeoecology Of The Albian To Santonian (Cretaceous) Of Bornholm, Denmark, Stephen Ronald Packer

School of Geography, Earth and Environmental Sciences Theses

The foraminiferal fauna recorded from the Amager Greensand, Amager Limestone and Bavnodde Greensand formations of Bornholm, Denmark are described herein. These formations range in age from Early Albian to Middle Santonian. The succession contains major breaks in deposition. A new foraminiferal biozonal scheme is presented, comprising six local assemblage biozones. These are compared to foraminiferal zonal schemes proposed for other areas of Northwest Europe. This data is then integrated with published data from macrofossil groups. Palaeoecological data is presented utilising foraminiferal group composition through the succession. An event synthesis is proposed for the study interval combining palaeoecology, biostratigraphy, lithostratigraphy and …

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The Determination Of Trace Metals In Concentrated Brines For Process Control, Howard William Handley Jan 1991

The Determination Of Trace Metals In Concentrated Brines For Process Control, Howard William Handley

School of Geography, Earth and Environmental Sciences Theses

The determination of the alkaline earths in concentrated feed brines is required for process control purposes in the chlor-alkali industry. Methodology was developed, based on ion-exchange chromatography, for the determination of alkaline earths in 30% sodium chloride. Brine samples were loaded onto a dynamically coated chelating ion-exchange column. The column selectively retained the analytes of interest while allowing the matrix to pass through unchanged. This allowed the simultaneous preconcentration of the analytes and matrix removal. Following the preconcentration step, the retained metals were backflushed from the column, using a lactic acid mobile phase, and separated by cation exchange chromatography. Detection …

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The Near-Miss Experience: Organization Change In The Maritime Bridge-Watch, Doward G. Douwsma Jan 1991

The Near-Miss Experience: Organization Change In The Maritime Bridge-Watch, Doward G. Douwsma

Other Faculty of Science and Engineering Theses

This thesis describes twenty-seven near-miss experiences by ten merchant marine officers on the U.S. Great Lakes. The experiences are related in the first person and include actions by self, other bridge watch members, and other vessels. The focus of the work is on the relationship between the near-miss experience and the organizational implications related to those experiences. The survey of the literature defines the near-miss experience and two major previous efforts to obtain and record maritime near-misses. The conceptual context places the near-miss in the traditional maritime organization which is defined through analysis of boundary and environment, horizontal and vertical …

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Opportunities And Constraints In Housing Private Tenants In Plymouth, Josephine Andrea Wright Jan 1991

Opportunities And Constraints In Housing Private Tenants In Plymouth, Josephine Andrea Wright

Other Faculty of Arts, Humanities and Business Theses

This thesis makes a contribution to research concerned with access to housing, but differs from the mainstream studies, both in its use of an individualist approach to illuminate differential opportunity within the housing market, and in its focus on private tenants. Its main purpose is to seek explanations for the variations in the housing situations of different types of privately renting household in Plymouth. This is achieved through an examination of the households’ financial and employment circumstances, and through an exploration of the constraints on choice which the households had experienced in the course of searching for accommodation. The work …

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The Misericords Of Beverley Minister : A Corpus Of Folkloric Imagery And Its Cultural Milieu, With Special Reference To The Influence Of Northern European Iconography On Late Medieval And Early Modern English Woodwork, Malcolm Haydn Jones Jan 1991

The Misericords Of Beverley Minister : A Corpus Of Folkloric Imagery And Its Cultural Milieu, With Special Reference To The Influence Of Northern European Iconography On Late Medieval And Early Modern English Woodwork, Malcolm Haydn Jones

Other Faculty of Arts, Humanities and Business Theses

The set of 68 misericords in Beverley Minster, Yorkshire, carved in 1520, are considered here both as a corpus of 'folkloric' imagery in their own right, and in a eider cultural context. A detailed iconographic examination of the individual misericords under such headings as 'The Fool and Follies', 'Satires', 'The bestiary' 'Exempla', etc., leads to the isolation of a small number of motifs which are seen not to belong to the native tradition. These non-English motifs are traced to two main sources, the border woodcuts in early Parisian printed Horae and Flemish & German prints. The identification of these sources …

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Observations Of Estuarine Turbulence And Floc Size Variations, Jeremy Charles Mccabe Jan 1991

Observations Of Estuarine Turbulence And Floc Size Variations, Jeremy Charles Mccabe

Other Faculty of Science and Engineering Theses

Laboratory studies show that turbulence controls the size of flocs by disrupting those flocs which exceed a critical diameter. Estuarine floc sizes have been shown to vary with the spring/neap cycle and turbulence has been suggested as the mechanism. A survey of the tidal variations of cohesive sediment floc size distributions and turbulence parameters has been undertaken in the Tamar estuary in south-west Britain. In-situ particle size distributions have been obtained using a 'marinised' version of the 'Malvern' laser diffraction sizing system. Turbulent current speeds were obtained using 10 cm diameter annular electromagnetic current meters. Velocity data is analysed using …

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The Existence And Use Of Benefit Segments In The Irish Sea Ferry Market, Sheelagh Maureen Matear Jan 1991

The Existence And Use Of Benefit Segments In The Irish Sea Ferry Market, Sheelagh Maureen Matear

Other Faculty of Arts, Humanities and Business Theses

In the last thirty years segmentation has been recognised as a fundamental concept in the understanding of a market. This research undertakes a benefit segmentation of the passenger and freight, sea and air transport markets between Great Britain and Ireland (both Northern Ireland and Eire). In so doing, two areas which have been under-researched are addressed; segmentation in a transport market and the Irish sea passenger and freight market. The dominant features of the Irish sea passenger and freight markets are identified; seasonality in the passenger market and imbalance in the freight market. The concept of segmentation is applied to …

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Development And Evaluation Of A New Scale To Measure Motivation, Clive Thacker Jan 1991

Development And Evaluation Of A New Scale To Measure Motivation, Clive Thacker

School of Psychology Theses

This programme of research was undertaken with the aim of using psychometric techniques to develop and evaluate a new scale to measure motivation. An initial hypothesis was stated, proposing that five related factors could be used to describe individual differences in certain motivational determinants. These factors are Goal Coherence, Strength of Will, Planning, Perseverance, and Self Evaluation. A questionnaire was constructed, and versions administered to 813 subjects over 5 studies. The resultant data were subjected to maximum likelihood factoring, and the solutions rotated obliquely. Results from each study led to successive refinements of the questionnaire, and an eventual rejection of …

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Evaluation Of Animal And Plant By-Products As Constituents In Diets For Seabream Sparus Aurata L., Ioannis Nengas Jan 1991

Evaluation Of Animal And Plant By-Products As Constituents In Diets For Seabream Sparus Aurata L., Ioannis Nengas

School of Biological and Marine Sciences Theses

The principle aim of the study was to evaluate the nutritional value of animal and plant by-products, with the objective of improving the cost effectiveness of diets for culturing seabream (Sparus aurata). The programme of work was initially directed towards applying the current methodology used in fish nutrition research to establish reliable digestibility coefficients for various feed ingredients. A selection of animal and plant materials were tested for digestibility within a reference basal diet designed for seabream. Ingredients for special consideration included poultry by-product meal, feather meal, meat and bone meal, solvent extracted and full fat soyabean meal as well …

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Evaluation Of Microbial Extracts For Contamination Control In Plant Tissue Culture Systems, Shayne Hussain Jan 1991

Evaluation Of Microbial Extracts For Contamination Control In Plant Tissue Culture Systems, Shayne Hussain

School of Biological and Marine Sciences Theses

Culture filtrates of 13 microbial antagonists exhibited in vitro growth inhibition of a range of test contaminations of herbaceous and woody plant tissue culture systems. Filtrates produced by Bacillus subtilis and Trichoderma viride isolates displayed the greatest broad- range inhibitory activity. Microscopic analysis of antagonized fungal mycelia revealed altered hyphal morphology. Maximum filtrate inhibitory activity was produced when selected antagonists were cultured within a pH range of 5-7 and a temperature range of 20-35°C. Filtrates were thermo-stable at 70°C and could be stored for up to 4 weeks with only a minimal reduction in their inhibitory activity. Bulk-volume production of …

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On-Line Analyte Preconcentration With Atomic Spectrometric Detection, L Ebdon, As Fisher, Sj Hill, Pj Worsfold Jan 1991

On-Line Analyte Preconcentration With Atomic Spectrometric Detection, L Ebdon, As Fisher, Sj Hill, Pj Worsfold

School of Geography, Earth and Environmental Sciences

Pre-concentration of analytes, or matrix removal to overcome interferences using mini- or micro-columns of exchange media prior to atomic spectrometric detection is becoming increasingly more common. This paper is a review of some of the more recent applications of chelating, ion exchange and other resins and gels that have been used to accomplish this.

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Building Society Marketing Strategies: The Role Of Service Image, Julie Robson Jan 1991

Building Society Marketing Strategies: The Role Of Service Image, Julie Robson

Plymouth Business School Theses

In recent years building societies have experienced dramatic change in the markets in which they operate. Deregulation has provided societies with the powers to enter new and very different markets. Societies wishing to re-work their strategies to exploit the new opportunities however did so with the knowledge that their own traditional markets had also to be protected from new competitors. Deregulation had provided access into the savings and mortgage markets to their natural competitors, the banks and insurance companies. The selection, by societies, of appropriate strategies thus became critical to their future success. Whilst recent studies have investigated the likely …

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The Role Of Small Firms In Employment And Innovation Generation, With Particular Reference To The Electronics Manufacturing Industry Of South West England, Claire Herbert Jan 1991

The Role Of Small Firms In Employment And Innovation Generation, With Particular Reference To The Electronics Manufacturing Industry Of South West England, Claire Herbert

Plymouth Business School Theses

This thesis examines the role of small firms in two key areas of economic activity, employment creation and innovation generation, through an exploration of existing literature and an empirical study of small firms in the electronics manufacturing industry of South West England. The work focuses initially on the scale of the small firm sector in terms of employment and on the ability of small firms to generate new jobs. Theoretical perspectives on the factors affecting the apparent resurgence of the small firm sector in the last two decades are also considered, and the effects of recession on small firm sector …

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An Information Processing Approach To Cognitive Recovery Following Closed Head Injury, Clive Skilbeck Jan 1991

An Information Processing Approach To Cognitive Recovery Following Closed Head Injury, Clive Skilbeck

School of Psychology Theses

The aim of this thesis was to investigate cognitive recovery following closed head injury within an information processing approach. Reasons why Clinical Neuropsychology has neglected the potential contribution from experimental psychology were outlined. Relevant head injury variables were reviewed. including the cognitive deficits often associated with such damage and their recovery. A pilot study confirmed that head-injured people, even soon after injury can attempt tasks with a high information processing load. The study covered the first six months post-injury using mild/moderate and severe head-injured subjects (total n=12). the findings indicating slower performance in severe subjects and their greater susceptibility to …

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A Knowledge Based Support Tool For The Early Stages Of Electronic Engineering Design, Dean Grant Curtis Scothern Jan 1991

A Knowledge Based Support Tool For The Early Stages Of Electronic Engineering Design, Dean Grant Curtis Scothern

School of Engineering, Computing and Mathematics Theses

A desire to produce a design support system for the early stages of electronic engineering design, has led to the conception of the Plymouth Engineer's Design Assistant (PEDA), pulling together experience from the three fields of computing, psychology and electronic engineering. The basic emphasis of this tool has been to use psychological techniques to analyze the cognitive aspects of designers in action and then make recommendations for design tool improvement. The results of the complementary psychological research, and other relevant literature are examined and potential avenues to realizing an improving design explored. A new idealized abstract representation of early electronic …

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An Evaluation Of The Effectiveness Of Video And The Formulation Of Hierarchical Models Of Student Understanding In Mechanics, Edward Graham Jan 1991

An Evaluation Of The Effectiveness Of Video And The Formulation Of Hierarchical Models Of Student Understanding In Mechanics, Edward Graham

School of Engineering, Computing and Mathematics Theses

This thesis reports on research into two areas. Firstly the evaluation of the effectiveness of video as a resource for the teaching of mechanics and secondly investigations into student understanding of mechanics concepts. The first of these two areas has been based on a controlled experiment, used to determine whether the use of video can lead to improved levels of student understanding among sixth form mathematics students. The data that has been collected from this experiment has revealed that there are virtually no statistically significant differences between the understanding of the control and experimental groups involved in the experiment. However, …

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The Trophic Level Of Mytilicola Intestinalis Steuer (Copepoda: Poecilostomatoida) In Mytilus Edulis L., As Determined From Stable Isotope Analysis, K Gresty, C Quarmby Jan 1991

The Trophic Level Of Mytilicola Intestinalis Steuer (Copepoda: Poecilostomatoida) In Mytilus Edulis L., As Determined From Stable Isotope Analysis, K Gresty, C Quarmby

School of Biological and Marine Sciences

Mytilicola intestinalis inhabits the digestive tract of the commercially important European blue mussel Mytilus edulis. Early researchers believed that Mytilicola damaged the host by feeding directly upon the epithelial lining of the host intestine, whilst more recent work indicated that it does not seriously affect the host and feeds upon excess food (phytoplankton and detritus) which passes through the mussel intestine. Comparative analysis of the stable isotope 15N shows that it is 2.8 ppt higher in whole Mytilicola than in mussel intestine, suggesting that Mytilicola occupies a higher a trophic level than Mytilus and therefore is unlikely to use the …

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Multiple Track Performance Of A Digital Magnetic Tape System : Experimental Study And Simulation Using Parallel Processing Techniques, Timothy John Jackson Jan 1991

Multiple Track Performance Of A Digital Magnetic Tape System : Experimental Study And Simulation Using Parallel Processing Techniques, Timothy John Jackson

School of Engineering, Computing and Mathematics Theses

The primary aim of the magnetic recording industry is to increase storage capacities and transfer rates whilst maintaining or reducing costs. In multiple-track tape systems, as recorded track dimensions decrease, higher precision tape transport mechanisms and dedicated coding circuitry are required. This leads to increased manufacturing costs and a loss of flexibility. This thesis reports on the performance of a low precision low-cost multiple-track tape transport system. Software based techniques to study system performance, and to compensate for the mechanical deficiencies of this system were developed using occam and the transputer. The inherent parallelism of the multiple-track format was exploited …

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