16 resultados para whole of catchment
em Aston University Research Archive
Resumo:
A procedure has been developed which measures the settling velocity distribution of particles within a complete sewage sample. The development of the test method included observations of particle and liquid interaction using both synthetic media and sewage. Comparison studies with two other currently used settling velocity test procedures was undertaken. The method is suitable for use with either DWF or storm sewage. Information relating to the catchment characteristics of 35 No. wastewater treatment works was collected from the privatised water companies in England and Wales. 29 No. of these sites were used in an experimental programme to determine the settling velocity grading of 33 No. sewage samples. The collected data were analysed in an attempt to relate the settling velocity distribution to the characteristics of the contributing catchment. Statistical analysis of the catchment data and the measured settling velocity distributions was undertaken. A curve fitting exercise using an S-shaped curve which had the same physical characteristics as the settling velocity distributions was performed. None of these analyses found evidence that the settling velocity distribution of sewage had a significant relationship with the chosen catchment characteristics. The regression equations produced from the statistical analysis cannot be used to assist in the design of separation devices. However, a grading curve envelope was produced, the limits of which were clearly defined for the measured data set. There was no evidence of a relationship between settling velocity grading and the characteristics of the contributing catchment, particularly the catchment area. The present empirical approach to settling tank design cannot be improved upon at present by considering the variation in catchment parameters. This study has provided a basis for future research into the settling velocity measurement and should be of benefit to future workers within this field.
Resumo:
This paper makes a case for taking a systems view of knowledge management within health-care provision, concentrating on the emergency care process in the UK National Health Service. It draws upon research in two casestudy organizations (a hospital and an ambulance service). The case-study organizations appear to be approaching knowledge (and information) management in a somewhat fragmented way. They are trying to think more holistically, but (perhaps) because of the ways their organizations and their work are structured, they cannot ‘see’ the whole of the care process. The paper explores the complexity of knowledge management in emergency health care and draws the distinction for knowledge management between managing local and operational knowledge, and global and clinical knowledge.
Resumo:
Abnormal neuronal intermediate filament (IF) inclusions immunopositive for the type IV IF α-internexin have been identified as the pathological hallmark of neuronal intermediate filament inclusion disease (NIFID). We studied the topography of these inclusions in the frontal and temporal lobe in 68 areas from 10 cases of NIFID. In the cerebral cortex, CA sectors of the hippocampus, and dentate gyrus granule cell layer, the inclusions were distributed mainly in regularly distributed clusters, 50-800 μm in diameter. In seven cortical areas, there was a more complex pattern in which the clusters of inclusions were aggregated into larger superclusters. In 11 cortical areas, the size of the clusters approximated to those of the cells of origin of the cortico-cortical pathways but in the majority of the remaining areas, cluster size was smaller than 400 μm. The topography of the lesions suggests that there is degeneration of the cortico-cortical projections in NIFID with the formation of α-internexin-positive aggregates within vertical columns of cells. Initially, only a subset of cells within a vertical column develops inclusions but as the disease progresses, the whole of the column becomes affected. The corticostriate projection appears to have little effect on the cortical topography of the inclusions. © 2006 EFNS.
Resumo:
In many circumstances, it may be of interest to discover whether two or more regression lines are the same. Regression lines may differ in three properties, viz., in residual variance, in slope, and in elevation; all of which can be tested using analysis of covariance. If there are no significant differences between regression lines, an investigator may which to combine the data from different studies and fit a single regression line to the whole of the data.
Resumo:
The lac promoter is widely used in plasmid expression systems, even though it is prone to catabolite repression. As a consequence glycerol is often used as an alternative carbon source. Three plasmids containing various sizes of the staphylococcal protein A (SPA) gene, which are under the control of the lac promoter were investigated in continuous culture, to evaluate the effects of nutrient limitations on their stability and expression. The fears of catabolite repression were dispelled as a low expression plasmid (pPA16) produced a greater amount of truncated SPA under glucose limiting conditions (11 ug mg-1 cell protein) when compared to that using glycerol (8 ug mg-1 cell protein). Segregational instability was also observed under glycerol limiting conditions at all the dilution rates investigated. Whereas pPA16 was relatively stable under glucose limiting conditions, with SPA production being continuous. Experiments using excess glycerol with limited ammonium increased the stability of pPA16, (when compared to limited glycerol) with expression of SPA being continuous but reduced (6 ug mg-1 cell protein). With excess glucose and limited ammonium the copy numbers remained high but expression of SPA paralled that produced under glucose limiting conditions. This might indicate that the higher levels of glucose are reducing expression (catabolite repression) or that the low level of ammonium is affecting protein production. A high expression plasmid (pPA31) produced nearly 100 ug full length SPA mg-1 cell protein, while another high expression plasmid (pPA34) producing truncated SPA proved to be very unstable. An ELISA was developed to detect the SPA produced by these experiments, which could be adapted for western blotting or immunogold probing using electron microscopy. SPA was localised in electron lucent areas present in the periplasmic space of the E. coli host harbouring pPA16. While in the same host containing pPA31, SPA was localised not only in electron lucent areas but also around the whole of the outer-membrane.
Resumo:
Physically based distributed models of catchment hydrology are likely to be made available as engineering tools in the near future. Although these models are based on theoretically acceptable equations of continuity, there are still limitations in the present modelling strategy. Of interest to this thesis are the current modelling assumptions made concerning the effects of soil spatial variability, including formations producing distinct zones of preferential flow. The thesis contains a review of current physically based modelling strategies and a field based assessment of soil spatial variability. In order to investigate the effects of soil nonuniformity a fully three dimensional model of variability saturated flow in porous media is developed. The model is based on a Galerkin finite element approximation to Richards equation. Accessibility to a vector processor permits numerical solutions on grids containing several thousand node points. The model is applied to a single hillslope segment under various degrees of soil spatial variability. Such variability is introduced by generating random fields of saturated hydraulic conductivity using the turning bands method. Similar experiments are performed under conditions of preferred soil moisture movement. The results show that the influence of soil variability on subsurface flow may be less significant than suggested in the literature, due to the integrating effects of three dimensional flow. Under conditions of widespread infiltration excess runoff, the results indicate a greater significance of soil nonuniformity. The recognition of zones of preferential flow is also shown to be an important factor in accurate rainfall-runoff modelling. Using the results of various fields of soil variability, experiments are carried out to assess the validity of the commonly used concept of `effective parameters'. The results of these experiments suggest that such a concept may be valid in modelling subsurface flow. However, the effective parameter is observed to be event dependent when the dominating mechanism is infiltration excess runoff.
Resumo:
The control needed in the management of a project was analysed with particular reference to the unique needs of the construction industry within the context of site management. This was explored further by analysing the various problems facing managers within the overall system and determining to what extent the organisation would benefit from an integrated mangement information system. Integration and management of information within the organisational units and the cycles of events that make up the main sub-system was suggested as the means of achieving this objective. A conceptual model of the flow of information was constructed within the whole process of project management by examining the type of information and documents which are generated for the production cycle of a project. This model was analysed with respect to the site managers' needs and the minimum requirements for an overall integrated system. The most tedious and time-consuming task facing the site manager is the determination of weekly production costs, calculation and preparation of interim certificates and valuation of variations occurring during the production stage and finally the settlement and preparation of supplier and sub-contractors' accounts. These areas where microcomputers could be of most help were identified and a number of packages were designed and implemented for various contractors. The gradual integration of stand-alone packages within the whole of the construction industry is a logical sequence to achieve integration of management system. The methods of doing this were analysed together with the resulting advantages and disadvantages.
Resumo:
In this thesis a modified Canon IR optometer was used to record static and continuous responses of accommodation during sustained visual tasks. The instrument was assessed with regard to the ocular exit pupil used, its frequency response and noise levels. Experimental work concerned essentially the temporal characteristics and neurological basis of the accommodative mechanism. In the absence of visual stimuli, the accommodative system assumes a resting or tonic accommodative (TA) position, which may be modified by periods of sustained fixation. The rate of regression from a near task to TA in darkness has exhibited differences between regression rates for enunetropes (EMMs) compared with late-onset myopes (WMs). The rate of accommodative regression from a task set at 3D above TA was examined for a group of 10 EMMs and 10 LOMs for 3 conditions: saline, timolol and betaxolol. Timolol retarded the regression to TA for a sub-group of EMMs. The patterns of regression for the remaining emmetropes mirrored that for the LOMs, the drugs showing no difference in rate of regression compared with the saline condition. This provides support for the conjecture that LOMs and certain EMMs appear to be deficient in a sympathetic inhibitory component to the ciliary muscle which may attenuate adaptational changes in tonus and which leave them susceptible to the development of LOM. It is well established that the steady-state accommodative response is characterised by temporal changes in lens power having 2 dominant frequency components: a low frequency component (LFC: < 0.6Hz) and a high frequency component (HFC: 1.0-2.2Hz). This thesis investigates various aspects of these microfluctuations of accommodation.The HFC of accommodative fluctuations was shown to be present in central and peripheral lens zones, although the magnitude of the rms of accommodative microfluctuations was found to be reduced in the lens periphery. These findings concur with the proposal that the lens capsule acts as a force distributor, transmitting the tension from the zonules evenly over the whole of the lens surface.An investigation into the correlation between arterial pulse and the HFC of accommodative fluctuations showed that the peak frequency of the HFC was governed by the arterial pulse frequency. It was proposed that the microflucutations comprised a combination of neurological control (LFC) and physiological variations (HFC).The effect of timolol maleate on the steady-state accommodative response for a group of 10 emmetropes showed that timolol reduced significantly the rms of accommodative microfluctuations in treated but not untreated eyes. Consequently, the effect was considered to be locally, rather than systemically induced.The influence of the sympathetic system on within-task measurements of accommodation was examined by recording the accommodative response of 3 subjects to a sinusoidally moving target at 6 temporal frequencies from 0.05Hz to 0.5Hz for 3 drug conditions: saline, timolol and betaxolol. Timolol caused a reduced gain for frequencies below 0.3 whereas betaxolol reduced accommodative gain for all frequencies. It was proposed that the results for timolol were consistent with temporal response characteristics of sympathetic innervation of the ciliary muscle whereas the betaxolol results were thought to be a manifestation of fatigue resulting from the CNS depressant effect of the drug.
Resumo:
Stéphane Mallarmé's texts on dance criticism occupy a prominent place in dance literature. They have also been of major interest to the Mallarme specialists who have seen in them the key to a greater understanding of the whole of his work. In this article I determine how his dance writings can be interpreted in the context of the whole of the œuvre, including for example the women's magazine he wrote and produced, La Dernière Mode. I establish to what extent the female presence in Mallarmé's poetry tends towards metaphors, women's bodies absent or negated by the gaze of the poet. As the poet responds to the stimulus of the dance, he divests the female dancer of her womanly characteristics, recasting her in his own imagination both as feminine principle and incarnation of 'l'Idée', and also as mythical being, 'au-delà de toute vie possible', a composite of other female characters inhabiting his œuvre, constantly poised between presence and absence, stillness and movement, a locus for a precarious balance which is endlessly re-enacted in h.is own writing practice.
Resumo:
This chapter contributes to the anthology on learning to research - researching to learn because it emphases a need to design curricula that enables living research, and on-going researcher development, rather than one that restricts student and staff activities, within a marketised approach towards time. In recent decades higher education (HE) has come to be valued for its contribution to the global economy. Referred to as the neo-liberal university, a strong prioritisation has been placed on meeting the needs of industry by providing a better workforce. This perspective emphasises the role of a degree in HE to secure future material affluence, rather than to study as an on-going investment in the self (Molesworth , Nixon & Scullion, 2009: 280). Students are treated primarily as consumers in this model, where through their tuition fees they purchase a product, rather than benefit from the transformative potential university education offers for the whole of life.Given that HE is now measured by the numbers of students it attracts, and later places into well-paid jobs, there is an intense pressure on time, which has led to a method where the learning experiences of students are broken down into discrete modules. Whilst this provides consistency, students can come to view research processes in a fragmented way within the modular system. Topics are presented chronologically, week-by-week and students simply complete a set of tasks to ‘have a degree’, rather than to ‘be learners’ (Molesworth , Nixon & Scullion, 2009: 277) who are living their research, in relation to their own past, present and future. The idea of living research in this context is my own adaptation of an approach suggested by C. Wright Mills (1959) in The Sociological Imagination. Mills advises that successful scholars do not split their work from the rest of their lives, but treat scholarship as a choice of how to live, as well as a choice of career. The marketised slant in HE thus creates a tension firstly, for students who are learning to research. Mills would encourage them to be creative, not instrumental, in their use of time, yet they are journeying through a system that is structured for a swift progression towards a high paid job, rather than crafted for reflexive inquiry, that transforms their understanding throughout life. Many universities are placing a strong focus on discrete skills for student employability, but I suggest that embedding the transformative skills emphasised by Mills empowers students and builds their confidence to help them make connections that aid their employability. Secondly, the marketised approach creates a problem for staff designing the curriculum, if students do not easily make links across time over their years of study and whole programmes. By researching to learn, staff can discover new methods to apply in their design of the curriculum, to help students make important and creative connections across their programmes of study.
Resumo:
Coleridge, looking back at the end of the ‘long eighteenth century’, remarked that the whole of natural philosophy had been ‘electrified’ by advances in the understanding of electrical phenomena. In this paper I trace the way in which these advances affected contemporary ‘neurophysiology.’ At the beginning of the long eighteenth century, neurophysiology (in spite of Swammerdam’s and Glisson’s demonstrations to the contrary) was still understood largely in terms of hollow nerves and animal spirits. At the end of that period the researches of microscopists and electricians had convinced most medical men that the old understanding had to be replaced. Walsh, Patterson, John Hunter and others had described the electric organs of electric fish. Gray and Nollet had demonstrated that electricity was not merely static, but flowed. Franklin had alerted the world to atmospheric electricity. Galvani’s frog experiments were widely known. Volta had invented his ‘pile.’ But did ‘animal electricity’ exist and was it identical to the electricity physicists studied in the inanimate world? Was the brain a gland, as Malpighi’s researches seemed to confirm., and did it secrete electricity into the nervous system? The Monros (primus and secundus), William Cullen, Luigi Galvani, Alessandro Volta, Erasmus Darwin, Luigi Rolando and François Baillarger all had their own ideas. This paper reviews these ‘long-eighteenth century’ controversies with special reference to the Edinburgh medical school and the interaction between neurophysiology and physics.
Resumo:
The initial aim of this research was to investigate the application of expert Systems, or Knowledge Base Systems technology to the automated synthesis of Hazard and Operability Studies. Due to the generic nature of Fault Analysis problems and the way in which Knowledge Base Systems work, this goal has evolved into a consideration of automated support for Fault Analysis in general, covering HAZOP, Fault Tree Analysis, FMEA and Fault Diagnosis in the Process Industries. This thesis described a proposed architecture for such an Expert System. The purpose of the System is to produce a descriptive model of faults and fault propagation from a description of the physical structure of the plant. From these descriptive models, the desired Fault Analysis may be produced. The way in which this is done reflects the complexity of the problem which, in principle, encompasses the whole of the discipline of Process Engineering. An attempt is made to incorporate the perceived method that an expert uses to solve the problem; keywords, heuristics and guidelines from techniques such as HAZOP and Fault Tree Synthesis are used. In a truly Expert System, the performance of the system is strongly dependent on the high quality of the knowledge that is incorporated. This expert knowledge takes the form of heuristics or rules of thumb which are used in problem solving. This research has shown that, for the application of fault analysis heuristics, it is necessary to have a representation of the details of fault propagation within a process. This helps to ensure the robustness of the system - a gradual rather than abrupt degradation at the boundaries of the domain knowledge.
Resumo:
Experirnental data and theoretical calculation on the heat transfer performance of extended surface submerged: in shallow air fluidized beds ~ less than 150 mm, are presented. Energy t;ransferrence from the bed material was effected by water cooled tubes passing through the fins. The extended surface tested was either manufactured from square or radial copper fins silver soldered to a circular basic tube or commercially supplied, being of the crimped or extruded helical fin type. Performances are compared, for a wide range of geometric variables, bed configurations and fluidized materials, with plain and oval tubes operating under similar experimental conditions. A statistical analysis of all results, using a regression technique, has shown the relative importance of each significant variable. The bed to surface heat transfer coefficients are higher than those reported in earlier published work using finned tubes in much deeper beds and the heat transfer to the whole of the extended surface is at least as good as that previously reported for un-finned tubes. The improved performance is attributed partly to the absence of large bubbles in shallow beds and it is suggested that the improved circulation of the solids when constrained in the narrow passages between adjacent fins may be a contributory factor. Flow visualisation studies between a perspex extended surface and a fluidized bed using air at ambient temperatures, have demonstrated the effect of too small a fin spacing. Fin material and the bonding to the basic tube are more important in the optimisation of performance than in conventional convective applications because of the very much larger heat fluxes involved. A theoretical model of heat flow for a radial fin surface, provides data concerning the maximum heat transfer and minimum metal required to fulfil a given heat exchange duty. Results plotted in a series of charts aim at assisting the designer of shalJow fluidized beds.
Resumo:
The research compares the usefullness of four remote sensing information sources, these being LANDSAT photographic prints, LANDSAT computer compatible tapes, Metric Camera and SIR-A photographic prints. These sources provide evaluations of the catchment characteristics of the Belize and Sibun river basins in Central America. Map evaluations at 1:250,000 scale are compared to the results of the same scale, remotely sensed information sources. The values of catchment characteristics for both maps and LANDSAT prints are used in multiple regression analysis, providing flood flow formulae, after investigations to provide a suitable dependent variable discharge series are made for short term records. The use of all remotely sensed information sources in providing evaluations of catchment characteristics is discussed. LANDSAT prints and computer compatible tapes of a post flood scene are used to estimate flood distributions and volumes. These are compared to values obtained from unit hydrograph analysis, using the dependent discharge series and evaluate the probable losses from the Belize river to the floodplain, thereby assessing the accuracy of LANDSAT estimates. Information relating to flood behaviour is discussed in terms of basic image presentation as well as image processing. A cost analysis of the purchase and use of all materials is provided. Conclusions of the research indicate that LANDSAT print material may provide information suitable for regression analysis at levels of accuracy as great as those of topographic maps, that the differing information sources are uniquely applicable and that accurate estimates of flood volumes may be determined even by post flood imagery.
River basin surveillance using remotely sensed data: a water resources information management system
Resumo:
This thesis describes the development of an operational river basin water resources information management system. The river or drainage basin is the fundamental unit of the system; in both the modelling and prediction of hydrological processes, and in the monitoring of the effect of catchment management policies. A primary concern of the study is the collection of sufficient and sufficiently accurate information to model hydrological processes. Remote sensing, in combination with conventional point source measurement, can be a valuable source of information, but is often overlooked by hydrologists, due to the cost of acquisition and processing. This thesis describes a number of cost effective methods of acquiring remotely sensed imagery, from airborne video survey to real time ingestion of meteorological satellite data. Inexpensive micro-computer systems and peripherals are used throughout to process and manipulate the data. Spatial information systems provide a means of integrating these data with topographic and thematic cartographic data, and historical records. For the system to have any real potential the data must be stored in a readily accessible format and be easily manipulated within the database. The design of efficient man-machine interfaces and the use of software enginering methodologies are therefore included in this thesis as a major part of the design of the system. The use of low cost technologies, from micro-computers to video cameras, enables the introduction of water resources information management systems into developing countries where the potential benefits are greatest.