Cranfield University at Silsoe (1975-2008)
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Item Open Access An adaptive grid algorithm for computational shock hydrodynamics(Cranfield University, 1991-01) Quirk, J. J.; Roe, P. L.During the development of computational methods that solve time dependent shock hydrodynamic problems, two underlying strategies have emerged that enable flow features to be resolved clearly. One, employ a numerical scheme of inherently high resolution, usually a second-order Godunov-type method. Two, locally refine the computational mesh in regions of interest. It has been demonstrated by Berger & Collela that a combination of both strategies is necessary if a solution of very high resolution is sought. The present study combines Roe's flux-difference splitting scheme with an adaptive mesh refinement algorithm developed from the ideas of Berger. The result being a general purpose scheme that can fully resolve complicated flows but which requires only modest computing power. The material in this thesis reflects three broad aims. First, to explain the methodology and intricacies of our scheme. Compared to non-adaptive methods our scheme is undeniably complicated, for it contains many elements which must be carefully co-ordinated. Second, to vindicate this complexity. To this end, computational results are presented which are comparable in resolution to Schlieren photographs, yet the calculations were performed on a small desktop workstation. Third, to give sufficient details of our implementation so as to allay the apprehensions of any person who might wish to code up the scheme.Item Open Access Advanced diffusion coatings for improved oxidation and corrosion performance(Cranfield University, 2001-08) Amperiawan, G.; Nicholls, J. R.Research to investigate advanced diffusion coatings for improved oxidation and hot corrosion resistance was conducted. The aim was to build on the performance of the standard aluminide on the nickel-base super alloy IN738LC. The main emphasis of this investigation was to examine the effects of adding small quantities of yttrium to the coating as well as to produce a platinum-modified aluminide diffusion coating which is accepted as the best industrial standard for diffusion aluminides at present. A pack diffusion process was used to produce the coatings in this current study. A standard aluminide coating was modified with a small YCI3 (0.5 Wt.%) addition to the pack, producing an aluminising-yttrising pack. In the platinum-modified altuninide coating process, a sample was coated with several microns of platinum using a sputtering technique prior to the aluminising process. The pack used in this platinum modified aluminide process was a standard aluminising pack. The performance of these modified coatings during oxidation and high temperature corrosion was evaluated. Promising results were obtained, which demonstrated that both platinum and yttrium modified aluminide coatings had beneficial effects on the oxidation performance of the coatings compared to the standard aluminide coating. However, they were found to work in different ways, to improve resistance to oxidation and hot corrosion resistance. The platinum modified aluminide extends the later stage of the coating life by reduces the amount of spall, whist yttrium modified aluminide reducing the amount of spall in the early stage of the coating life and increases the critical oxide thickness before the onset of spallation. From these results, the production of a combined platinum-yttrium modified aluminide coating would be expected to show improved oxidation and hot corrosion resistance throughout the life of the coating. This could be another direction for future work.Item Open Access Agricultural Futures and Implications for the Environment.(2005-11-01T00:00:00Z) Morris, Joe; Audsley, Eric; Wright, Iain A.; McLeod, Jim; Pearn, Kerry R.; Angus, Andrew; Rickard, SeanIn this context, the overall aim of project is to explore possible long term futures for agriculture in England and Wales in order to inform decision-making on environmental policy and provide a 2 framework for Defra research on sustainable agriculture, climate change and other environmental issues.Item Open Access Agricultural tractor powertrains: Fundamental characteristics and opportunities for intelligent control(Cranfield University, 2005-07-08) Sayer, David; Scarlett, A. J.; Godwin, R. J.The use of microprocessor-based control systems on agricultural tractors has eased operator burden by allowing changes to tractor and implement settings to be made with little physical effort. However, maintaining the optimum tractor-implement settings whilst encountering the variable nature of agricultural conditions still requires a high level of operator skill, partly due to the need to adjust individual sub-system controllers. CAN-bus communication between electronically controlled vehicle sub. systems provided a new opportunity to enhance vehicle powertrain operation, by intelligently integrating control of the sub-systems. The aim of the project was to develop ways to improve the operational characteristics of a tractor powertrain, by investigating system behaviour, and identifying opportunities for intelligent control. Market research was undertaken which highlighted power-split continuously variable transmissions as a credible alternative to powershift-type transmissions in specific specialist applications where the additional purchase price could be justified. However, there is little scientific evidence to suggest that there are significant improvements in overall vehicle performance to be gained through the use of a CVT tractor compared to a well operated powershift-type transmission. Improvements to gearshift quality and more intelligent use of the powertrain control features could ensure powershift-type transmissions remain competitive for the foreseeable future. A dynamic mathematical powertrain model was developed for a lOOkW, 16 speed semi-powershift transmission, four wheel drive tractor based on fundamental Newtonian principles. With the addition of implement models, this allowed accurate representation of the tractor-implement system and provided a platform to develop improved vehicle control strategies. Validation of the model with experimental data showed it was an accurate representation of the real system. The steady state and transient field performance of the tractor operating with a mouldboard plough, a power harrow and a laden trailer was determined for a number of tractor-implement configurations across a range of conditions. This provided a David Sayer, 2005 Cranfield University, Silsoe 11 large dataset for this vehicle for use in this, and other investigations. The level of powertrain loading for field experiments was found to be influenced by soil type, implement working width and depth as well as forward speed and engine speed. For the road investigation, the surface quality and terrain were major influencing factors on performance. It was found there was considerable variation in tractor response to the different gearshift types experienced in the semi-powershift transmission: the non-powershift changes being severe, particularly during downshifts; double-swap powershifts were markedly more severe than single-swap shifts. A unique investigation of the tractor driveline torque loss characteristics across the full operating spectrum using the axle dynamometer identified that the torque losses for this transmission are predominantly speed, rather than torque related. A mathematical model was developed to predict driveline torque losses from transmission output speed, flywheel torque and the number of power-transmitting gears in mesh. The axle dynamometer was also used to successfully replicate field loading patterns in real time. Throughout this investigation a number of undesirable powertrain characteristics were identified. Potential improvements to vehicle performance through the development of solutions to these characteristics have been made either through analysis of field data, experiments with the axle dynamometer, or using the developed mathematical model.Item Open Access Aircraft conceptual design decision through operational modelling(Cranfield University, 2005) Harasani, W.; Smith, HowardAircraft manufacturing is not only a difficult business but also a very competitive one, the consequences of any drop in sales would cost billions, loss of jobs, and maybe an economical failure. Therefore, concentrating on just flight performance and adding new technologies just because they exit is not enough to win the airlines attention, especially the flow cost carriers. Manufactures must be able to convince operators that the application of a new design or technology will produce a favourable change in the bottom line of their balance sheets and not just a reduction in fuel burn. Aircraft designers must put more emphasis on what happens to the aircraft after it leaves the assembly line, through the designed life operation cycle of the aircraft with the airline customer, quality should be built in to the aircraft. Knowing what are the airline's concerns, how the aircraft with a given design behaves, and the issues that the airline has, is vital. Firstly, it is important to know what are the issues that the airline has, the costumer (airlines) needs are identified, and, since fleet planning is the top level decision making department in the airline in which a decision is made to buy one aircraft over the other, it is important to understand the process and the elements that are involved in fleet planning. So fleet planning was studied. Second different technologies for the design have been looked at and selected. Then the aircraft, airline, airport, and air traffic control are studied, as well as the interaction between them. A key element of the research is a simulation program DEBOS that has been built to see the impact of the different design technologies and concepts through the operation of a simulation fleet size of 23 aircraft. The Boeing777 aircraft has been chosen to be the base line of the study. Finally, it was found that a given technology with improved performance, or a new concept, would improve the aircraft attractiveness only if it has better life cycle behaviour characteristics.Item Open Access Aircraft parameter estimation by estimation - before - modelling technique(Cranfield University, 1995-11) Hoff, J. C.; Cook, M. V.The use of the estímation-before-modellíng (EBM) two step identification procedure for the determination of aircraft aerodynamic derivatives from flight test data is analysed and illustrated. In the first step of the identification procedure the usual Extended Kalman Filter (EKF) associated with the Modified Bryson-Frazíer (MBF) smoother is compared with a new alterative filtering and smoothing process. The new smoother is simpler and less computationally demanding than the MBF smoother. However, its main advantage is that it enables simultaneous data smoothing with state derivative estimation, thereby avoiding the need for a separate differentiation algorithm. The new smoother differentiator has an important feature that is the determination of the noise characteristics of the measurement signal under analysis prior to the smoothing process. This is done by variance matching between the theoretical and measured autocorrelation of the innovation process generated by a Kalman filter. The new technique is compared with the old one by determining the aerodynamic models for a EMB-312 Tucano dutch roll manoeuvre. It is demonstrated that the new smoother may be used to replace the MBF. Otherwise the new technique is used in the analysis of the Handley Page Jetstream-100 aircraft low speed controls free phugoid trying to identify the contribution of the power Variation observed during the phugoid to the stability of the oscillation. Finally the models obtained from the phugoid analysis are reprocessed using the Total Least Square regression and the results are compared with those from the ordinary Least Square formulation.Item Open Access Alternative chemical control of anthracnose and crown rot of banana caused by Colletotrichum musae(2000-11) Khan, Sabir Hussain; Aked, JuliaChemical alternatives to the fungicides currently used to control Colletotrichum musae infections on banana fruit have been investigated. Four isolates of C. musae cultured from anthracnose lesions on imported banana fruit were screened against the fungicides thiabendazole (TBZ) and imazalil incorporated into malt extract agar (MEA). Two of the isolates showed some tolerance to TBZ even at 1.24 mM (250 ppm), whereas all four isolates were very sensitive to imazalil at concentrations of > 0.017 mM (5 ppm). One susceptible (CM100) and one tolerant (CM103) isolate (to TBZ) was selected. Eleven chemicals were evaluated over a range of concentrations for their effectiveness in inhibiting the germination and mycelial growth of these isolates in vitro (on MEA). The chemicals were the antioxidants ascorbic acid, propionic acid, benzoic acid, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propyl paraben (PP), propyl gallate (PG), dimethyl sulphoxide (DMSO), thiourea and tannic acid and the natural plant product azadiractin. BHA, azadiractin, benzoic acid, PP and PG gave the highest levels of fungal inhibition in vitro. BHA at 5 mM completely inhibited the germination and mycelial growth of CM100 and CM 103 at 25°C. BHA (1 mM) in combinations with benzoic acid (1 mM), PP (1 mM) or imazalil (1.68 pM) completely inhibited germination and mycelial growth of CM103 at 14 and 25°C. The effectiveness of imazalil was not affected by the pH of the medium whereas the effectiveness of BHA was greatest at pH 3.5 and 6.5 and benzoic acid was more effective at lower pH values. C. musae was shown to produce nine extracellular enzymes in liquid medium which have not been reported before including lipases, phosphatases and hydrolases. BHA, imazalil and TBZ caused differential inhibition of the production or activity of these enzymes. The toxicity of selected chemicals was tested against anthracnose or crown rot infections of fingers or hands of banana fruits. Inoculations of C. musae were made with either mycelium in wounds in the banana peel or with conidia on the intact surface of the fruit or on the cut stalk or crown tissues. Of the alternative chemicals tested on their own, BHA and azadiractin gave the greatest inhibition of anthracnose and crown rot infections with dip treatments at 1 mM giving control levels ranging from 10-39% compared with 17.6-38.3% for imazalil (0.84 mM = 250 ppm). BHA (5 mM) in combinations with imazalil (0.84 mM), PP (10 mM) or benzoic acid (10 mM) suppressed anthracnose lesions (CM103) by 64.7, 54.9 and 35.3 %, and crown rot development by 70.5, 62.3 and 42.6 % at 25°C respectively. At 14°C these same combinations gave complete control of anthracnose lesions and crown rot development. TBZ was less effective at controlling crown rot (CM100 or CM 103) than imazalil alone or when in combinations with BHA. Combinations of BHA with imazalil but not with TBZ showed synergism both in vitro and in vivo. The cost/litre of the best trial treatment (BHA at 5 mM with imazalil at 0.84 mM) was less than that of imazalil at 1.68 mM (500 ppm). This suggests that food grade phenolic antioxidants such as BHA may be useful adjuncts to currently used fungicides such as imazalil for commercial control of banana postharvest diseases.Item Open Access Aluminide-based coatings for turbine blade internal cooling passages(Cranfield University, 2004-10) Long , K.; Nicholls, J. R.The development of aero-gas turbines is moving towards more efficient engines with higher pressure ratios and increased Turbine Entry Temperatures. This leads to increases in overall turbine blades temperatures which has resulted in the widescale development of turbine blades with film cooling and Thermal Barrier Coatings (TBCs) which reduce the metal temperature of the blade. The air used for film cooling is directed around the blade by internal passages within the blade, current engines are experiencing hot corrosion in areas of these internal passages, even with internal aluminide coatings. The trend for more efficient engines means that corrosion of the internal passages will become more common, coupled with the inability to inspect the internal passages of turbine blades in service, results in a requirement for an improved coating for the internal passages of turbine blades. The aim of this study was to develop a coating which provides improved corrosion and oxidation performance over a standard vapour aluminide on single crystal CMSX-4 turbine blades material. The coating needs to be compatible with the Rolls- Royce bond coat and the Rolls-Royce manufacturing strategy. The study investigated a number of additions which could be used to improve the performance of an aluminide coating. Silicon was selected as the optimum addition on the basis of performance and ease of deposition. The work then assessed the influence of various production parameters on the formation of a silicon-aluminide coating. It was possible to control the level of silicon deposited in the coating. Performance testing, using cyclic oxidation and salt recoat hot corrosion tests, of various silicon aluminides developed in this programme demonstrated at least a doubling in life compared with vapour aluminide coatings.Item Open Access Amperometric biosensor for formic acid in air(Elsevier, 2000-11-01) Sandström, K. J. Mattias; Newman, Jeffrey D.; Sunesson, Anna-Lena; Levina, Jan-Olof; Turner, Anthony P. F.The possibility of developing a simple, inexpensive and specific personal passive ”real-time” air sampler based on biosensor technology was investigated. Formic acid was used as a model substance. The sensor is based on the enzymatic reaction between formic acid and formate dehydrogenase with NAD+ as a cofactor and Meldola’s blue as mediator. An effective way to immobilise the enzyme, cofactor and Meldola’s blue on screen-printed electrodes was found to be in a mixture of glycerol and phosphate buffer covered with a gas-permeable membrane. When the sensor was introduced into an atmosphere containing formic acid, it gave a distinct and rapid amperometric response.Item Open Access Analysis of sweet corrosion profiles(Cranfield University, 1990-05) Esfahani, A.; Strutt, J. E.The sweet corrosion profiles of X-52 carbon steel in 0.l% NaCl at 30, 40, 50 and 60°C were analysed. The corrosion tests lasted for a period of one month. They were performed using a flow loop under a total gas pressure of 1 atm. containing carbon dioxide (99.95% & 100 vpm O2). The corrosion profiles were obtained by scanning the corroded surfaces with a stylus. The results were analysed and compared with linear polarisation resistance (LPR) data. lt has been found that the (LPR) data at 40°C, i the absence of significant pitting, progressively underestimated the actual metal loss values. It has been proposed that the above discrepancy is due to the occurrence of small scale localised corrosion. The above effect was found to be exaggerated at 60°C, where extensive pitting occurred. Attempts to find a correlation between the (LPR) measurements and the actual metal loss distributions were unsuccessful. Furthermore, although sudden increase of the instantaneous corrosion rates for passive samples appeared to signal the onset of localised attack, i the absence of prior knowledge of the relative spread of the localised corrosion, it was not possible to quantify the observed errors. The range of the metal loss distributions was found to increase with time. This was most notíceable at 60°C. The progress of localised corrosion therefore, appears to have extended the distributions towards the extreme values. It has been proposed that, in the absence of severe pitting, the sweet corrosion profiles can be approximated by the Weibull statistical function. For pitted samples, where the localised attack resulted i metal loss on different scales, the upper 10% of the values were also found to be approximated by the Weibull function. The Weibull function was used for predicting the progress of the metal loss values with time. The analysis of the top 10% values, for pitted surfaces at 60°C, however, suggested the occurrence of an accelerating rate of attack. The original model was therefore improved to provide a time dependent sweet corrosion model. It has been estimated that the corrosion rate at 60°C increases with time at intervals of approximately 8 days. The effect of methanol on the sweet corrosion of X-52 carbon steel in 1% NaCl was also studied under stagnant conditions at 4, 40 and 60°C. The partial pressure of carbon dioxide was maintained at 0.3 bar. lt has been found that the corrosion rate decreases with increasing methanol concentration. The data was used to develop a predictive model within the range of 10 to 60% vol. methanol.Item Open Access Anglian Region: River Yare, River Wensum, Woldgrift Drain(National Rivers Authority, 1996) Dunderdale, J. A. L.; Morris, J.This document describes methods, results and conclusions of a study to evaluate the impacts of alternative river maintenance strategies on the River Yare and Wensum and the Woldgrift Drain in the Anglian Region. Its main purpose are to provide supporting information for R&D Note 456 'River Maintenance Evaluation' and to provide data which supports routines for the prioritisation and programming of river maintenance.Item Open Access Application of a hydrological model in a data-poor tropical West African catchment: a case study of the Densu Basin of Ghana(Cranfield University, 2005-11) Bekoe, Emmanuel Obeng; Holman, Ian P.This thesis reports on the suitability of using a hydrological model to predict the impact of future catchment changes on the surface water resources of tropical West African catchments, as a basis for sustainable watershed management strategies. The economically-important but data-poor Densu Basin (2100km2) in Ghana is used as a case study. Prior to the identification of an appropriate model, a range of model selection criteria to achieve the research objectives were developed, which included minimum data requirements. Following a review of available models, the ACRU hydrological model was chosen using these selection criteria. As this is the first use of the ACRU model in the Tropics, a sensitivity analysis was performed to gain a better understanding of the correspondence between the data and the physical processes being modelled and to inform future data collection priorities. The most sensitive parameters identified were rainfall; soil water content at field capacity and monthly crop coefficients. The sensitive parameters were different from those previously identified for semi arid regions, thereby improving the wider understanding of the behaviour of the ACRU model in a new climatic region of Africa for future studies. Although the ACRU model performed well during calibration (e.g. Nash and Sutcliff Efficiency > 0.8), it performed poorly during the validation period (e.g. NSE < 0.5). Aggregation of the daily output to monthly averages improved the performance appraisal statistics to a level where the model is appropriate for longer term water management issues such as irrigation planning and water supply planning. However, the prediction of the hydrological consequences of future catchment changes using the model could not be performed due to the variable model performance. A detailed analysis of input data quality and model performance identified a number of contributory reasons which included the poor distribution of available data from rain gauges and evaporation stations, poor data management and problems with groundwater processes within ACRU. Recommendations to the Densu River Basin Management Board to address the main problem area of data quality include ensuring that all data (new as well as existing) is subject to QC/QA procedures, the development of data archiving / back-up systems, making historical data available to the wider hydrological community; and guidance on deriving model inputs from available data for future modellers. Finally recommendations on which areas need further study during future research using the ACRU model are given.Item Open Access Application of a vane-recessed turbular-passage casing treatment to a multistage axial-flow compressor(Cranfield University, 2001-11) Akhlaghi, M; Elder, R. L.The current study investigates a range of issues relating to the use of a vane-recessed tubular-passage casing treatment as a passive stall control technique in a multistage axial-flow compressor. The focus of the research was to determine whether such a treatment could delay the initiation of stall at lower mass flow rates as well as providing the most beneficial improvement in flow characteristics without sacrificing compressor efficiencies. Specific objectives of this study were to examine possible improvements or deterioration in the flow characteristics including stall margin, peak pressure rise coefficients and maximum efficiency in a multistage axial flow compressor. A casing treatment in addition to several spacer rings was developed from two initial designs and tested on the first stage of a low speed three-stage axial-flow compressor with a (0.7) hub to tip diameter ratio. The treatment configuration consisted of three parts: an outer casing ring, with a tubular shaped passage on the inside diameter, a set of 120 evenly spaced curved vanes, and a shroud or inner ring. The casing treatment was positioned following the inlet guide vanes upstream and partly covering the tip of the rotor blades. The main parts of the casing treatment including the recessed vanes in addition to some of the spacer rings were manufactured from high quality acrylic. Eight additional spacer rings of various shapes and geometry were added. The first ring held and partly covered the IGVs, in front of the casing treatment. The rotor tip exposure ratio was thought to have a significant impact on the effectiveness of the casing treatment. Therefore the other seven rings were used to provide the desired uncovered region of the rotor tip axial chord of about 10% in order to provide a range of exposures of (23.2%, 33.3%, 43.4%, 53.5%, 63.6%, 73.7%, and 83.8%). The results showed significant improvements in stall margin in all treated casing configurations along with insignificant efficiency sacrifices in some compressor builds. About (28.56%) of stall margin improvement in terms of corrected mass flow rate was achieved using a casing treatment with a (33.3%) rotor tip exposure. The compressor build with (0.535) rotor exposure ratios was the best configuration in terms of efficiency gain and loss characteristics. This build was able to provide the highest values of the maximum efficiencies in comparison with the performance achieved from the solid casing. An improvement of (1.81%) in the maximum efficiency in terms of the overall total-total pressure ratio, in association with a (22.54%) stall margin improvement in terms of the corrected mass flow rates were achieved by the application of this treatment configuration. The improvement in the peak pressure rise coefficients in terms of the overall total-total pressure ratio, obtained from this build was (2.33%). The compressor configuration using a casing treatment with a (0.636) rotor exposure ratio was the best build in terms of the pressure rise coefficients. This configuration was able to provide highest value of the peak pressure rise in comparison with the characteristics achieved from the datum build. An improvement of (2.65%) in the peak pressure rise coefficient in terms of the overall total-total pressure ratio, in association with a (22.49%) improvement in stall margin in terms of the corrected mass flow rates was achieved from this casing treatment build. The improvement in maximum efficiency in terms of the overall total-total pressure ratio, obtained from this build was (1.03%). The results suggest that the vane-recessed tubular-passage casing treatment designed as part of this investigation achieved the objectives, which were established for the research. In the majority of instances it not only produced gains in flow range, pressure rise coefficients and efficiencies, but also enabled the rotating stall, which developed at much lower mass flow rates in the compressor, to become progressive rather than abrupt.Item Open Access Application of GIS and remote sensing for land use planning in the arid areas of Jordan(2000-01) Ziadat, Feras M.; Taylor, J. C.Land suitability analysis formed part of a land use planning exercise in a development project aimed at improving agricultural productivity in the transitional Badia region of Jordan. Soil observations and soil maps were available at three levels of detail with differing coverage: level one (1:250,000 scale -complete cover), level two (1:50,000 scale - part cover) and level three (1:10,000 scale very limited cover). The development project selected the FAO Framework for Land Evaluation as the basis for land suitability analysis. This research investigated seven different calculation approaches for the processing of soil observations within soil map polygons using a GIS to derive land suitability ratings. These methods either use the soil observations to calculate the suitability of each soil mapping polygon or an interpolation technique (Voronoi diagram or Triangulated Irregular Network) between observation points. The overall map purity and homogeneity with respect to land characteristics were used to evaluate these methods. The quality of suitability maps varied according to the level of soil mapping and the method of processing the soil observations. The relative performance of the processing methods is discussed and recommendations for each level of mapping are proposed. The results showed that the purity of suitability maps was between 60 and 70% at the highest level of detail. Thus they should be used with caution for site specific analyses. Statements of map quality should be appended to suitability maps. The soil maps and observation points were derived and collected in a previous soil survey programme and georeferenced by map reading before the widespread availability of the Global Positioning System (GPS). When the data were integrated and overlaid on a satellite image within a GIS, a number of inconsistencies in georeferencing the data and in the attributes attached to them were revealed. Investigation and correction of these evolved into a major component of this work. Systematic errors caused by the use of different datums to georeference soil maps and observation points in the Jordan Soil and Climate Information System (JOSCIS) were detected. The map reading procedure also caused unsystematic errors in the locations of soil observations, which were re-measured at a sample of original observation sites using GPS. The correction of the unsystematic errors was not feasible due to the difficulty and cost of relocating all observation points. Errors in the attributes attached to the observation points were caused by survey recording procedures, highlighting the need for an examination of the data before analysis. The systematic and attribute errors were corrected and the implication for suitability analysis examined. The areas and spatial distribution of different suitability classes were affected increasingly as the level of mapping became more detailed. The presence of all these errors was sufficient to create errors in the derived land suitability maps, which could lead to incorrect land use planning decisions. The integration of satellite imagery, soil observations and soil mapping polygons within a GIS was indispensable for quality control of the data. The highest purities of suitability maps using existing soil mapping polygons were between 60% to 70% at level three but they only covered veiy limited areas. This indicated the need to extend mapping at this detail for site-specific planning and if possible, to increase the purity of soil mapping units. This was investigated by integrating satellite imagery and topographic data in a GIS. A 3-D perspective view of a Landsat TM image using an air photo-derived DEM was the most promising way of using the available data. Further research is needed to investigate the interactive use of air photo-derived DEMs and Landsat images, with more focus applied to site specific planning and field verification of the technique. Although this work was necessarily focussed on the issues and problems particular to one data set used in a Jordanian context, a number of general lessons have been learned. Firstly, careful examination of all input data is necessary to eliminate georeferencing and attribute errors. Secondly, overlay of input data onto a geocoded satellite image is extremely useful for detecting potential sources of input data errors and is recommended. And thirdly, GIS is indispensable for investigating existing data for errors and exploring new methods of analysis.Item Open Access Application of ion exchange for ammonium removal from municipal wastewaters(Cranfield University, 2007-01) Thornton, A.; Parsons, SimonTraditional methods of ammonium removal from municipal wastewaters rely on naturally occurring biological processes, where ammonium is converted into less harmful substances before being released into the environment. These processes are extremely effective at nitrogen removal but are less responsive to shock loads, in which case they can fall short of achieving the required effluent quality. In recent years research has been conducted into the possibility of using ion exchange technology as a complementary process for the. removal of ammonium from wastewater streams. Much of the research has been concerned with the .performance of naturally occuring materials, zeolites, with much of the work being undertaken at laboratory scale using synthetic solutions. This study investigates the performance of the modified media, MesoLite, using real and synthetic solutions, at both laboratory and pilot scale, in the presence of competing cautions. Initial studies were performed under batch conditions to assess the effect of a number of parameters such as contact time, solution ammonium concentration and pH on the uptake of ammonium on to MesoLite. This was followed by a investigation into a number of design parameters under dynamic conditions, leading to a pilot scale examination of the potential of the process to be used for the application of removing ammonium from low concentration wastewater treatment works effluents. Subsequent experiments were performed pilot scale to investigate the benefit of using the ion exchange process for ammonium removal from high strength liquors arising from the sludge dewatering process. Results indicate that a range of parameters affects the performance of the media and optimum performance is observed at high ammonium concentrations with increased contact time at pH 6-7. Results also show that MesoLite was successful in removing ammonium from high concentration sludge liquors, giving a total capacity of 47-51 g + -1 + -1 NH4 N kg and a operational capacity of 27 36 g NH4 N kg . The treatment of low concentration effluents return a total capacity of 19 g NI-14+-N kg`1 and a operational capacity of 9.5 g NI-14+-N kg`1. However, this reduced capacity is offset by the significant increase run time, from 1.5 to 22 days, and a increase in the amount of liquid treated from 140 bed volumes to in excess of 6000 bed volumes.Item Open Access The application of land evaluation technique in the north-east of Libya(Cranfield University, 2006-08-10T13:45:00Z) Nwer, Bashir Ahmad Bashir; Hallett, Stephen; Brewer, Timothy R.Land evaluation is a prerequisite to achieving optimum utilisation of available land resources for agricultural production. The principal purpose of land evaluation is to predict the potential and the limitations of land for changing use. Food security is one of the most important issues of agriculture policy in Libya. The country aims to obtain self‐sufficiency for its in agricultural products which contribute largely to the diet of most of the population. Therefore, eighty per cent of water transferred from aquifer‐sourced in the south of the country to the north, is planned for agriculture development. Cereal crops such wheat, barley, maize and sorghum are given the highest priority. There is, therefore, a pressing need to develop an optimal land evaluation method to identify in which part of a region these selected crops could e grown favourably. The model should be developed in accordance with the priorities of the Libyan Government in developing a practical and applicable land evaluation system that can be used by the average computer user. The FAO Framework was selected to conduct the land suitability assessment. This selection was based upon extensive and critical review of land evaluation methodologies and an evaluation of the objectives for and of the data available for study area. The FAO framework is a set of guidelines rather than a classification system, and model used builds upon this.Item Open Access The application of metrics to the measurement of quality systems(Cranfield University, 1995-01) Williamson, A.; Vella, A. D.Quality system auditing has been a topic of much recent discussion but there has not been a commensurate amount of research on how the audit process can make more effective use of auditor time and improve the quality of their judgements. An approach certification bodies and their clients may adopt is to measure the quality system activities of the client, and use these measurements (or metrics) to improve their understand of the quality system. If these metrics were available to auditors, they could identify the strengths and weaknesses of the quality system and assist in deciding if the client complies with ISO 9000. This could make the audit process more cost-effective and focused. A detailed study of the current auditing process used by certification bodies, and a survey of auditors, identified the quality system activities that provide the most confidence that the company has a compliant quality system. The "quality loop" activities of internal audit/management review and corrective action were found to be both the most important activities in showing compliance and provide the basis of metrics that can inform the auditor about the state of health of these activities. Metrics capable of measuring the other quality system activities required by ISO 9000 are identified, and their effectiveness in monitoring the quality system is discussed. The research shows that metrics concerned with the quality loop can provide useful information to an auditor and can help them in reaching a judgement. It is also shown that the use of metrics is constrained by organisational and technical factors, such as the size of the organisation being measured and the correspondence between the activity being measured and the requirements of ISO 9000.Item Open Access Application of the ecosystem functions framework to community woodlands(Cranfield University, 2007-02) Agbenyega, Olivia; Burgess, Paul J.; Cook, M. V.The UK government provides financial incentives to land owners who promote community use of newly-planted woodlands. De Groot et al. (2002) have developed a framework for classifying ecosystem functions. This research applies this framework to identify and describe perceptions of the function, use and value of community woodlands in order to inform local management and government policy. The research was an exploratory and descriptive case study with an initial flexible and final fixed stage. A poplar wood (Pegnut Wood) and two mixed-broadleaf woodlands(Clapham Park Wood and Reynolds Wood), all planted in Bedfordshire between 1993 and 1998, provided the case studies. Data collection methods included semi-structured interviews, self-administered structured questionnaires, direct observation, modelling of tree data and review of secondary documents. In total 172 out of 400 local residents, 20 on-site visitors, and 8 other stakeholders (owners, government institutions and conservation groups) gave responses. The primary motivations of the owners for establishing the woods were production, information and habitat functions. However financial cost-benefit analyses indicated negative returns to owners without government grants. In the first set of interviews 43- 58% of the local respondents at each site described the selected woods and community woods as “very important”. There was a significant positive association between nearness to the woods and level of importance. Those who visited the woods placed greatest emphasis on the use of the woods for exercise and recreation (48-64%), and as a wildlife habitat (50-52%). Using the ecosystem function framework, local respondents at Pegnut Wood and Clapham Park Wood placed greatest value on habitat (29-39%) and information functions (33-38%) and lowest value on regulation (14-19%), production (5-8%) and negative functions (7-8%). Respondents at Reynolds Wood placed the greatest relative importance on negative functions (36%). Across the three sites, local respondents placed the greatest relative value on the use of the woodlands as a habitat for wild plants and animals (14%) and to provide landscape beauty (12%). A second set of interviews, focussed on the recreational use of the woodlands, showed that the main purpose for visiting the woods was walking (median frequency of once a month and duration of between 31-60 minutes). Fifteen out of 88 respondents indicated that they were willing to contribute to support the woods. Many of those not in favour felt such support was a government responsibility. Overall, owners, local residents, government and local conservation groups showed similar relative valuations of the different functions and uses of community woodlands, indicating that there was substantial scope for working together. The research showed that it was useful to apply the ecosystem functions framework to community woodlands. It provided a structure for analysing planting objectives and it encouraged a focus on indirect uses. Stakeholders recognised potential negative functions of the woodland, and it proved useful to include these in the framework. We note the challenges in recognising and placing a high value on the regulation function amongst the range of stakeholders. The framework also helped to identify synergies and tensions between stakeholders without the need for monetising values.Item Open Access Applications of volatile fingerprint sensor arrays for rapid detection of environmental contaminants(Cranfield University, 2005-03) Canhoto, Olinda; Aldred, David; Magan, NareshThe electronic nose (e-nose) technology has rapidly evolved in the past decade with a range of applications in the food industry, medical diagnosis, and recently environmental monitoring. This is the first time that this technology has been examined in detail for a range of specific environmental applications including: detection of low concentrations of bacterial, fungal and heavy metal contaminants in potable water; analyses of changes in the microbial activity of soil samples amended with heavy metals; and the detection of fungal contaminants in paper samples from library material. In some studies comparisons between different e-nose systems has also been carried out. The e-nose system based on a conducting polymer (CP) sensor array Bloodhound (BH114) was able to detect different bacterial species (Escherichia coli, Pseudomonas aeruginosa and Enterobacter aerogenes), initially inoculated in tap, reverse osmosis and bottled water with a concentration of 102 cells mL-1, after 24 hrs incubation. In the presence of low concentrations (0.5 ppm) of a mixture of heavy metal ions including cadmium, lead and zinc, the volatile pattern produced by the bacterial species was discriminated from that where no metal was added, probably due to a change in the microbial metabolism. The Bloodhound e-nose system was also used to detect fungal spores of Aspergillus fumigatus, Fusarium culmorum and a Penicillium species, inoculated in water samples. The initial concentrations were 102 – 105 spores mL-1. Good discrimination was observed between the control samples after 24 hrs incubation at 25oC. After 48 hrs incubation, it was possible to differentiate between the various spore concentrations present in water samples. Good reproducibility was achieved as results from different days were consistent and data could be pooled and combined for analysis. A comparative study was performed with three e-nose instruments, two of them had CP sensor arrays (Bloodhound (BH-114); Neotronics (eNOSE 4000), and the third was a metal oxide (MO) sensor-based system, the NST 3220. The experiments carried out with the CP based-systems showed similar results when analysing water samples contaminated with 104 and 102 bacterial cells mL-1 after 24 hrs incubation. Both CP and MO based e-nose systems could differentiate control water samples from those contaminated with both bacteria and fungal spores. GC-SPME analyses confirmed the results obtained with the e-nose system of metal ions and bacterial cells in water samples. At-line studies were performed with the MO array-based system (NST 3220), for the detection of contamination episodes. E. coli and P. aeruginosa cells were used as contamination agents for tap and reverse osmosis sterile water, in two concentration levels, 102 and 106 cells mL-1. The samples collected downstream in a simulated watercourse, were analysed by the e-nose over a period of 1-2 hrs. The results suggested the potential of this technique to monitor episodes of bacterial cells at a low concentration in water samples. Experiments performed in soil samples artificially and naturally contaminated with heavy metal ions were analysed with the MO-based e-nose system. Results indicated that for artificially contaminated soil samples, after 40 days incubation the control samples could be discriminated from those containing 3 and 100 ppm of metal ions. For naturally contaminated soils, the sensor array was only able to separate samples containing a high concentrations of metal ions. Headspace analysis of cellulose-based agar showed good discrimination between Aspergillus terreus, A. hollandicus and Eurotium chevallieri, after 20 hrs incubation at 25oC. An increase in the incubation period to 40 hrs resulted in better separation between the control and fungal treatments. In situ studies performed on paper samples suggested that the e-nose was able to discriminate between control samples and paper inoculated with 103 fungal spores mL-1. The substrate was a determinant factor in the headspace analysis of microbial species. It was shown that the same fungal species produced different volatile profiles according to the growth substrate.Item Open Access Approaches to allergy detection using aptasensors(Taylor and Francis, 2007) Brys, Emile; Tombelli, Sara; Minunni, Maria E.; Mascini, Marco; Turner, Anthony P. F.1. Immunoglobulins and IgE Antibodies are glycoprotein molecules which are produced by plasma cells in response to an immunogen (1). They belong to a class of spherical proteins called globulins and are hence known as immunoglobulins (Igs). Their primary function is to mediate the host immune response by binding to antigens.