• Observation inflation and self-action inflation. Investigation of source memory errors as a result of action observation and action performance

      Lesk, Valerie E.; Mitrenga, Kaja Julia (University of BradfordDivision of Psychology, Faculty of Social Sciences, 2015)
      This thesis investigates two source memory errors: observation inflation, where observed actions are misremembered as being performed; and self-action inflation in which self-performed actions are misremembered as having been performed by somebody else. It has been proposed that these inflations occur because of overlapping brain activity during observation and performance. This has been attributed to mirror neurone activity. To test this, observation and self-action inflations are investigated for different types of actions (meaningful, meaningless and communicative) known to evoke different mirror neurone activity. Different age groups (young adult, and elderly) were studied as were the effects of relative ethnicity between observer and performer. The Remember-Know-Guess paradigm was used. This showed that people make inflations with high qualitative details and confidence. As anticipated, elderly participants made significantly more observation inflations than young adults. Across both age groups, significantly more inflations occurred for communicative and meaningful actions than for meaningless actions supporting the idea that mirror neurones may be involved in formation of inflations. However when the effects of relative ethnicity were included in the paradigm it was found that significantly more observation inflations were formed after observing different ethnicity actors. It has been hypothesised that if mirror neurone involvement is involved in observation inflations then the highest number of inflations are expected for the same ethnicity condition because of the overlap between participant and performer. This thesis therefore suggests a less simplistic explanation of the underlying mechanisms responsible for these types of memory error.
    • Occupational Pension Schemes and their Relevance for the Employment Relationship in Germany. A Case Study Approach in the German Financial Services Sector

      Prowse, Peter J.; Smith, Andrew J.; Lütke Kleimann, Mechthild (University of BradfordFaculty of Management and Law, 2018)
      Due to employees’ reduced entitlements to the German statutory state pension on the one hand, and the challenge to employers of a skilled worker shortage on the other, employers’ contributions towards occupational pension schemes (OPS) might be an effective human-resources management tool. Thus, the overarching research question is: What is the relevance of OPS for the employment relationship in Germany? Five sub-research questions address the role of OPS in recruitment and retention management, organisational commitment, the potential differences between women and men and between young and old employees and the employees’ psychological contract. The empirical study is a single case study in the financial-services sector. Key findings: OPS are of more relevance for retaining employees than for recruiting them. Their role differs significantly between employees with different generations of the OPS and, therefore, different pension entitlements. Only minor differences can be found between women and men and between younger and older employees. Satisfaction with the occupational pension scheme has no significant impact on organisational commitment. The majority of employees perceived psychological contract fulfilment with respect to the OPS. The contribution to theory is the closure of five research gaps. As far as is known, this is the first study in Germany that analyses the role of OPS in a specified context and from multifaceted viewpoints (recruitment/retention, quantitative/qualitative, men/women, age groups). The contribution to practice comprises the provision of a transferable analysis blueprint of the role of OPS in the employment relationship and the provision of recommendations that relate, among others, to communication and information aspects, cost-benefit calculations and the usage of additional employer contributions as a possible selective reward element.
    • Ocular accommodation control and adaptive optics. The development of monocular and binocular adaptive optics instrumentation for the study of accommodation and convergence, and study of the monocular accommodative response to rapid changes in dioptric stimuli.

      Mallen, Edward A.H.; Cufflin, Matthew P.; Curd, Alistair P. (University of BradfordBradford School of Optometry and Vision Science, School of Life Sciences, 2015-07-01)
      The relationship between accommodation and myopia has been under investigation for many years, and the effort to understand it is ongoing. In this thesis, an introduction to the state of myopia research is given first, with particular reference to studies of accommodation and higher-order ocular aberrations, which feature in the subsequent chapters. Following a brief introduction to the general technique of aberrometry and visual stimulus control using adaptive optics, the development of a monocular adaptive optics instrument for this purpose is described. The instrument is used to vary a dioptric stimulus and record the accommodation response in pilot studies and a detailed experiment, which has also been published elsewhere. It is found, among other things, that accommodation can respond to more than one different input level during its latency period, and that such inputs can be stored until components of the accommodation control system are free to process them. Indications of a minimum halting time for accommodation, of around 0.6 s, are presented. In later chapters, the development and testing of a new, binocular adaptive optics apparatus will be found. As well as binocular aberrometry and adaptive optics control of stimulus aberrations, this instrument displaces images to allow for and stimulate ocular convergence in binocular accommodation experiments. It is the first instrument in the world with its combined functionalities. Finally, the contribution of this thesis is summarised, and further instrumentation development and experiments are put forward for the continuation of this branch of accommodation and myopia research.
    • Ocular biometric change in orthokeratology. An investigation into the effects of orthokeratology on ocular biometry and refractive error in an adult population.

      Douthwaite, William A.; Mallen, Edward A.H.; Gilchrist, James M.; Parkinson, Annette (University of BradfordBradford School of Optometry and Vision Science, 2014-05-07)
      Aim; This study looks at the effect of orthokeratology on a number of biometric parameters and refractive error in an adult population. Method; Forty three myopic subjects were recruited to a twelve month study into the effects of orthokeratology on ocular biometry and refractive error. Two different back surface lens designs were applied right eye) pentacurve and left eye) aspheric. The aspheric design was chosen to more closely mimic the cornea¿s natural shape. Anterior and posterior apical radii and p-values; corneal thickness and anterior chamber depth were measured using the Orbscan IIz; together with ocular biometry by IOL Master and a standard clinical refraction. All measurements were repeated at one night, one week, one, three, six and twelve months. Refractive changes were analysed against biometric changes. Results; Twenty seven participants completed one month of lens wear. Twelve subjects completed twelve months of lens wear. Subjects with myopia ¿ -4.00DS were successfully treated with orthokeratology. Both anterior and posterior apical radii and p values were altered by orthokeratology. Corneal thickness changes were in agreement with previously published studies. Axial length and anterior chamber depth were unaffected by the treatment. Conclusion; Orthokeratology should be available as an alternative to laser refractive surgery. It is best restricted to myopes of up to -4.00DS with low levels of with the rule corneal astigmatism. The use of an aspheric back design contact lens did not produce a significant benefit over that of a pentacurve.
    • An odontological study of ovicaprine herding strategies in the North Atlantic islands. The potential of dental enamel defects for identifying secondary product utilisation in an archaeological context.

      Mainland, Ingrid L.; Ewens, Vicki J. (University of BradfordDepartment of Archaeological Sciences, 2011-10-06)
      Recent debate concerning the suitability of mortality profile analysis for identifying secondary product utilisation within archaeozoological assemblages has prompted the search for alternative methodologies. This research explores the potential of using weaning age to provide insight into herding strategies in ovicaprines, determined through the prevalence of developmental enamel defects. A histological methodology was developed, adapted to the specific nature of sheep molars through an understanding of formation processes and enamel structures. This established a relationship between weaning and developmental defects in modern sheep, revealed as distinct patterns in defect distribution within the enamel. Based on historical/archaeological data a weaning age model was developed for the North Atlantic region by which herding strategies could be recognised, specifically: mixed milk/meat subsistence, with an emphasis on milk (0-2 months) or on meat (2-4 months), and the optimisation of meat and/or wool (4-6 months). This methodology was then tested on archaeological material to interpret husbandry at Iron Age and Norse/Viking period sites. The results of this analysis showed that interpretations were in general agreement with those of mortality profile and correspondence analysis conducted as a methodological comparative. Some disparity, however, highlighted the ability of this new technique to provide more sensitivity in cases of mixed subsistence systems, possibly identifying the economic focus of husbandry, or where mortality profiles are confused. It was concluded that the study of weaning age has potential to provide valuable insight into ovicaprine husbandry in archaeological contexts, adding to the understanding of faunal assemblages, especially when supported with other evidence.
    • Oganisational boundaries and determinants of behaviour in organisations: A situational analysis. A conceptual and empirical inquiry into the determinants of behaviour of organisational members having direct contact with an organisation's exterior, emphasising the perception of situations which occur in work routines.

      Randell, Gerry; Butcher, David J. (University of BradfordPostgraduate School of Studies in Management and Administration., 2010-02-17)
      This study is concerned with furthering an understanding of the behaviour of organisational boundary personnel, or more exactly, with how boundaries act as psychological environments. The study has two complementary aims: to describe the psychological environment encountered by boundary personnel and to offer a theoretical model of the organisation as a psychological environment, the latter being a prerequisite of the former. It is held that a social psychological perspective is needed which can deal adequately with organisations as antecedent conditions of behaviour, and that situational analysis offers a useful social psychological framework for this purpose. The empirical investigation is an initial descriptive study of the psychological environment encountered by boundary personnel. It is argued that initial descriptive studies are necessary when dealing with largely unstudied phenomena, and that this stage in the scientific process has often been undervalued by social psychologists. A diary analysis followed by interviews were used to elicit a range of situations encountered by boundary personnel having direct and frequent contact with customers and clients. Four organisations were studied, each having a different primary task. A self-completion questionnaire was administered to elicit judgemental data, using the situations as stimuli. Multidimensional scaling was applied to analyse the data, treated as four sub-sets. This yielded the dimensions underlying each data set and the representation of situations according to these dimensions in each case. The results suggest that three common dimensions (formality, anxiety and socio-emotionality) underlie the cognitive representations of boundary personnel, and that the psychological environment encountered is complex. A taxonomy of situations is constructed and several important hypotheses relating to the psychological environment of boundary personnel formulated. Implications for future research are discussed.
    • On the Edge: Power and Partnership in Social Work

      Kelly, Nancy; Karban, Kate E.
      This submission for the award of PhD by Published Work includes a range of single, joint and multiple-authored publications that were published between 2005 and 2016. The publications cover a range of issues relevant to social work with a particular emphasis on mental health and health inequalities. The statement provides an underpinning conceptual framework that demonstrates interwoven themes of power, partnership and marginality. These are explored in relation to the published work, demonstrating an original and coherent contribution to the social work knowledge and practice base. The discussion draws on a reflexive journey through social work practice, education and research. The conclusion proposes that considerations of power and partnership are crucial elements of the potential for creative work ‘on the margins’.
    • On the role of correspondence noise in human visual motion perception. A systematic study on the role of correspondence noise affecting Dmax and Dmin, using random dot kinematograms: A psychophysical and modelling approach.

      Tripathy, Srimant P.; Cox, Michael J.; Shafiullah, Syed N. (University of BradfordBradford School of Optometry and Vision Science, 2010-04-01)
      One of the major goals of this thesis is to investigate the extent to which correspondence noise, (i.e., the false pairing of dots in adjacent frames) limits motion detection performance in random dot kinematograms (RDKs). The performance measures of interest are Dmax and Dmin i.e., the largest and smallest inter-frame dot displacement, respectively, for which motion can be reliably detected. Dmax and threshold coherence (i.e., the smallest proportion of dots that must be moved between frames for motion to be reliably detected) in RDKs are known to be affected by false pairing or correspondence noise. Here the roles of correspondence noise and receptive field geometry in limiting performance are investigated. The range of Dmax observed in the literature is consistent with the current information-limit based interpretation. Dmin is interpreted in the light of correspondence noise and under-sampling. Based on the psychophysical experiments performed in the early parts of the dissertation, a model for correspondence noise based on the principle of receptive field scaling is developed for Dmax. Model simulations provide a good account of psychophysically estimated Dmax over a range of stimulus parameters, showing that correspondence noise and receptive field geometry have a major influence on displacement thresholds.
    • On-line shear and extensional rheometry of polymer melts in the extrusion process.

      Coates, Philip D.; Kelly, Adrian L. (University of BradfordInterdisciplinary Research Centre for Polymer Science and Technology, Department of Mechanical and Manufacturing Engineering., 2009-06-11)
      A novel on-line capillary rheometer (OLR) was used to examine the shear and extensional characteristics of polyolefin melts during twin screw extrusion (TSE). Comparisons with off-line rheometry were made using a twin-bore capillary rheometer and a modular in-line slit die rheometer (ILR) provided in-line rheometry comparisons. Both capillary rheometers were controlled via PCs running dedicated software, and the extrusion line and ELR were fully instrumented allowing real-time process monitoring to be carried out by IBM compatible PCs via data acquisition hardware and software. The prototype OLR was developed by the re-design of several key features including an instrumented transfer section and capillary die block which facilitated the use of various die geometries. Shear and extensional on-line rheometry of three polyethylenes (linear and branched), and four molecular weight grades of polypropylene were examined, and a direct comparison with off-line capillary rheometry showed a good correlation. The effect of a high loading of filler on two of the polyethylenes was investigated. In-line shear stress and entry pressure measurements showed a reasonable correlation with on-line rheometry. A study of entry flows in the OLR using capillary dies approaching orifice showed non-linearities occurred at very low capillary length to diameter(L:D) ratios, and this was repeatable using off-line rheometry. Predicted zero length entry pressures (Po) were used to estimate apparent extensional viscosity using a number of standard models. Melt instability and capillary wall slip were also investigated using on-line rheometry. Melt pressure and temperature in the twin screw extruder and OLR were monitored at various process conditions to examine the ability of the OLR to condition melt during testing, and the effect of OLR testing on extrusion conditions. Pressure variation in the extruder, OLR and off-line rheometer were compared in order to quantify process noise. The effect of OLR testing on melt rheology and polymer molecular weight were examined using off-line rheometry and gel permeation chromatography(GPC).
    • Oncoproteomic applications for detection of breast cancer. Proteomic profiling of breast cancer models and biopsies

      Sutton, Chris W.; Patterson, Laurence H.; Shaheed, Sadr-ul (University of BradfordFaculty of Life Sciences, 2017)
      The heterogeneity of breast cancer (disease stage and phenotype) makes it challenging to differentiate between each subtype; luminal A, luminal B, HER2, basal-like and claudin-low, on the basis of a single gene or protein. Therefore, a collection of markers is required that can serve as a signature for diagnosing different types of breast cancer. New developments in proteomics have provided the opportunity to look at phenotype-specific breast cancer cell lines and stage-specific liquid biopsies (nipple aspirate fluid [NAF], plasma samples) to identify disease and phenotype specific signature. An 8-plex iTRAQ quantification strategy was employed to compare proteomic profiles of a range of breast cancer and ‘normal-like’ cell lines with primary breast epithelial cells. From this, 2467 proteins were identified on Orbitrap Fusion and Ultraflex II, of which 1430 were common. Matched pairs of NAF samples from four patients with different stages of breast cancer, were analysed by SCX-LC-MS and a total of 1990 unique gene products were identified. More than double the number of proteins previously published data, were detected in NAF, including 300 not detected in plasma. The NAF from the diseased patients have 138 potential phenotype biomarkers that were significantly changed compared to the healthy volunteer (7 for luminal A, 9 for luminal B, 11 for HER2, 14 for basal-like and 52 for claudin-low type). The average coefficient of variation for triplicate analyses by multiple reaction monitoring mass spectrometry (MRM-MS), was 9% in cell lines, 17 % in tissue biopsies, 22% in serum samples and 24% in NAF samples. Overall, the results provide a strong paradigm to develop a clinical assay based on proteomic changes in NAF samples for the early detection of breast cancer supplementary to established mammography programmes.
    • Ontologies and knowledges of autonomous resistances in Barcelona: An ethnographic analysis of Can Batlló

      Chesters, Graeme S.; Ferrer Sanz, Maria N.
      This research is born from a conscious reflection on the roles and judgements that traditional scientific analyses imprint in its objects of study, especially in the field of social movement theory. It aims to understand whether and, to which extent, autonomous resistances knowledges constructed on the ground challenge the academic interpretations of those movements. For this reason, the first part of this dissertation focuses on unravelling how traditional ontologies have been built and underpin majoritarian scientific analyses. Thus, I review most current debates in the field. Traditional social movement research tends to focus on dualist discussions related to new and old social movements, European and American approaches, behavioural or cost-benefits views, structural and agency approaches, identity-based interpretations, etc. In opposition to that, I argue for an ontology breaking with dualist views, placing Deleuze’s concept of difference at the centre of my argument and feminist ontologies of the body as the medium affecting the political experience. I propose an autoethnographic method focused on presenting a cartography of urban resistance movements composed by difference and rhizomatic relationships in opposition to the homogenisation of ideas and demands of academic research for pilling up patterns, variables or categories. Deleuze and Guattari’s concept of the BwO is presented here as a theoretical tool that helps to introduce the case study in relation with its contexts, relationships, affects and networks. The second part of this research narrates and analyses how the proposed theory is unwrapped in the field. In doing so, I analyse my participation with and from within one of those collectives, Can Batlló and, more specifically, a project named La Fondona. Can Batlló is an autonomous and self-organised social centre in the neighbourhood of La Bordeta in Barcelona with which I worked during six months between 2013 and 2014. Throughout this period, I participated actively not only in Can Batlló but also in the actions and events that took place in the neighbourhood of Sants-Montjuïc and Barcelona. Hence, I present an analysis of the internal processes, relations and knowledge-practices as well as the relationships that this collective maintains with the community, its sociopolitical space and historical context. I argue those relations are constructed through rhizomatic principles as well as drawing from feminist approaches which put life and the body at the centre of their arguments. These outcomes will be finally reflected in chapter IX of this dissertation under the lenses of the research question posed in this thesis. That is whether current urban resistances challenge majoritarian social movements’ analyses.
    • Operating System Based Perceptual Evaluation of Call Quality in Radio Telecommunications Networks. Development of call quality assessment at mobile terminals using the Symbian operating system, comparison with traditional approaches and proposals for a tariff regime relating call charging to perceived speech quality.

      Gardiner, John G.; Al-Mashouq, K.; Aburas, Akram (University of BradfordSchool of Engineering, Design and Technology, 2012-10-18)
      Call quality has been crucial from the inception of telecommunication networks. Operators need to monitor call quality from the end-user¿s perspective, in order to retain subscribers and reduce subscriber ¿churn¿. Operators worry not only about call quality and interconnect revenue loss, but also about network connectivity issues in areas where mobile network gateways are prevalent. Bandwidth quality as experienced by the end-user is equally important in helping operators to reduce churn. The parameters that network operators use to improve call quality are mainly from the end-user¿s perspective. These parameters are usually ASR (answer seizure ratio), PDD (postdial delay), NER (network efficiency ratio), the number of calls for which these parameters have been analyzed and successful calls. Operators use these parameters to evaluate and optimize the network to meet their quality requirements. Analysis of speech quality is a major arena for research. Traditionally, users¿ perception of speech quality has been measured offline using subjective listening tests. Such tests are, however, slow, tedious and costly. An alternative method is therefore needed; one that can be automatically computed on the subscriber¿s handset, be available to the operator as well as to subscribers and, at the same time, provide results that are comparable with conventional subjective scores. QMeter® ¿ a set of tools for signal and bandwidth measurement that have been developed bearing in mind all the parameters that influence call and bandwidth quality experienced by the end-user ¿ addresses these issues and, additionally, facilitates dynamic tariff propositions which enhance the credibility of the operator. This research focuses on call quality parameters from the end-user¿s perspective. The call parameters used in the research are signal strength, successful call rate, normal drop call rate, and hand-over drop rate. Signal strength is measured for every five milliseconds of an active call and average signal strength is calculated for each successful call. The successful call rate, normal drop rate and hand-over drop rate are used to achieve a measurement of the overall call quality. Call quality with respect to bundles of 10 calls is proposed. An attempt is made to visualize these parameters for better understanding of where the quality is bad, good and excellent. This will help operators, as well as user groups, to measure quality and coverage. Operators boast about their bandwidth but in reality, to know the locations where speed has to be improved, they need a tool that can effectively measure speed from the end-user¿s perspective. BM (bandwidth meter), a tool developed as a part of this research, measures the average speed of data sessions and stores the information for analysis at different locations. To address issues of quality in the subscriber segment, this research proposes the varying of tariffs based on call and bandwidth quality. Call charging based on call quality as perceived by the end-user is proposed, both to satisfy subscribers and help operators to improve customer satisfaction and increase average revenue per user. Tariff redemption procedures are put forward for bundles of 10 calls and 10 data sessions. In addition to the varying of tariffs, quality escalation processes are proposed. Deploying such tools on selected or random samples of users will result in substantial improvement in user loyalty which, in turn, will bring operational and economic advantages.
    • An operations management perspective of knowledge management: towards a knowledge management assessment and improvement tool.

      Barber, Kevin D.; Beach, Roger; Kapofu, Desmond (University of BradfordSchool of Management, 2013-11-22)
      This thesis describes the development of a Knowledge Management (KM) Assessment tool for the Operational level of the organisation. Its main focus is to help organisations to identify the KM activities and mechanisms that they could improve in order to improve their operational efficiency. Current KM literature is lacking in guiding organisations in what they need to do in order to implement and formalise KM in their operations with a view to improving operational efficiency. Therefore the aim of this thesis is to fill this gap in the literature and also to influence the manner in which KM is practiced. The research project has three distinct stages: the model development, modification and testing stages. The model development stage synthesises KM literature and a pilot study in order to develop a conceptual model of the KM assessment tool. The second stage of the research project describes the application of the tool in three organisations and details the modifications that were made as a result. Finally, the third stage tests the final version of the KM Assessment tool using four case organisations. The KM Assessment tool presented in this thesis is not a prescriptive KM solution; it emphasises the need to approach KM from a process and task specific perspective. Put another way, KM improvements should be implemented to reflect the processes and task charactaristics of each individual organisation. However, the thesis presents a method of evaluation of such that is unform across organisational types
    • Optimal design and operation of multivessel batch distillation with fixed product demand. Modelling, simulation and optimisation of design and operation parameters in multivessel batch distillation under fixed product demand scenario and strict product specifications using simple dynamic model in gPROMS.

      Mujtaba, Iqbal M.; Mahmud, Mohamed Taher Mustafa (University of BradfordSchool of Engineering, Design and Technology, 2010-09-28)
      Increased interest in unconventional batch distillation column configurations offers new opportunities for increasing the flexibility and energy efficiency of batch distillation. One configuration of particular interest is multivessel batch distillation column, which can be viewed as a generalization of all previously studied batch column configuration. In this work, for the first time the optimal design and operation tasks are developed for multivessel batch distillation with strict product specifications under fixed product demand. Also, in this work, two different operation schemes defined as STN (State Task Network) in terms of the option and numbers of off-cuts were considered for binary and ternary separation. Both the vapour load and number of stages in each column section together with the production sequence are optimised to achieve maximum profit function. The performance of the multivessel batch distillation column is evaluated against the performance of conventional batch column with a simple dynamic model using binary and ternary mixtures. It has been found that profitability improves with the multivessel system in both separations. gPROMS, a user-friendly, software is used for the modeling, simulation, and optimisation.
    • Optimal investment in an oil-based economy. Theoretical and Empirical Study of a Ramsey-Type Model for Libya.

      Jalilian, Hossein; Weiss, John A.; Zarmouh, Omar Othman (University of BradfordDevelopment and Project Planning Centre, 2010-07-23)
      In a developing oil-based economy like Libya the availability of finance is largely affected by the availability of oil revenues which are subjected to disturbances and shocks. Therefore, the decision to save and invest a certain ratio of the country's aggregate output is, to large extent, determined (and affected) by the shocks in the oil markets rather than the requirements of economic development. In this study an attempt is made to determine the optimal rate of saving and investment, both defined as a ratio of the aggregate output, according to the requirements of economic development. For this purpose, a neo-classical Ramsey-type model for Libya is constructed and applied to obtain theoretically and empirically the optimal saving and investment rate during the period (1965-1991). The results reveal that Libya was investing over the optimal level during the oil boom of 1970s and less than the optimal level during the oil crisis of 1980s. In addition, an econometric investigation of the determinants of actual investment by sector (agriculture, non-oil industry, and services) is carried out in order to shed lights on how possible it is for Libya to adjust actual investment towards its optimal level. It is found that, as expected, the most important factor which can be used in this respect is the oil revenues or, generally, the availability of finance. In addition, the study reveals that investment in agriculture is associated, during the period of study, with a very low marginal productivity of capital whereas marginal productivity was higher in both non-oil industry and services. Finally, the study investigates also the future potential saving and investment rates and concludes that the economy, which has already reached its steady state, can be pushed out towards further growth if the economy can be able to increase the level of per worker human capital, proxied by the secondary school enrolment as a percentage of population.
    • Optimal Multi-Drug Chemotherapy Control Scheme for Cancer Treatment. Design and development of a multi-drug feedback control scheme for optimal chemotherapy treatment for cancer. Evolutionary multi-objective optimisation algorithms were used to achieve the optimal parameters of the controller for effective treatment of cancer with minimum side effects.

      Hossain, M. Alamgir; Majumder, Md A.A.; Algoul, Saleh (University of BradfordSchool of Computing, Informatics and Media, 2013-01-23)
      Cancer is a generic term for a large group of diseases where cells of the body lose their normal mechanisms for growth so that they grow in an uncontrolled way. One of the most common treatments of cancer is chemotherapy that aims to kill abnormal proliferating cells; however normal cells and other organs of the patients are also adversely affected. In practice, it¿s often difficult to maintain optimum chemotherapy doses that can maximise the abnormal cell killing as well as reducing side effects. The most chemotherapy drugs used in cancer treatment are toxic agents and usually have narrow therapeutic indices, dose levels in which these drugs significantly kill the cancerous cells are close to the levels which sometime cause harmful toxic side effects. To make the chemotherapeutic treatment effective, optimum drug scheduling is required to balance between the beneficial and toxic side effects of the cancer drugs. Conventional clinical methods very often fail to find drug doses that balance between these two due to their inherent conflicting nature. In this investigation, mathematical models for cancer chemotherapy are used to predict the number of tumour cells and control the tumour growth during treatment. A feedback control method is used so as to maintain certain level of drug concentrations at the tumour sites. Multi-objective Genetic Algorithm (MOGA) is then employed to find suitable solutions where drug resistances and drug concentrations are incorporated with cancer cell killing and toxic effects as design objectives. Several constraints and specific goal values were set for different design objectives in the optimisation process and a wide range of acceptable solutions were obtained trading off among different conflicting objectives. Abstract v In order to develop a multi-objective optimal control model, this study used proportional, integral and derivative (PID) and I-PD (modified PID with Integrator used as series) controllers based on Martin¿s growth model for optimum drug concentration to treat cancer. To the best of our knowledge, this is the first PID/I-PD based optimal chemotherapy control model used to investigate the cancer treatment. It has been observed that some solutions can reduce the cancer cells up to nearly 100% with much lower side effects and drug resistance during the whole period of treatment. The proposed strategy has been extended for more drugs and more design constraints and objectives.
    • Optimal scheduling, design, operation and control of reverse osmosis desalination. Prediction of RO membrane performance under different design and operating conditions, synthesis of RO networks using MINLP optimization framework involving fouling, boron removal, variable seawater temperature and variable fresh water demand.

      Mujtaba, Iqbal M.; Sassi, Kamal M. (University of BradfordSchool of Engineering Design and Technology, 2013-11-20)
      An accurate model for RO process has significant importance in the simulation and optimization proposes. A steady state model of RO process is developed based on solution diffusion theory to describe the permeation through membrane and thin film approach is used to describe the concentration polarization. The model is validated against the operation data reported in the literature. For the sake of clear understanding of the interaction of feed temperature and salinity on the design and operation of RO based desalination systems, simultaneous optimization of design and operation of RO network is investigated based on two-stage RO superstructure via MINLP approach. Different cases with several feed concentrations and seasonal variation of seawater temperature are presented. Also, the possibility of flexible scheduling in terms of the number of membrane modules required in operation in high and low temperature seasons is investigated A simultaneous modelling and optimization method for RO system including boron removal is then presented. A superstructure of the RO network is developed based on double pass RO network (two-stage seawater pass and one-stage brackish water pass). The MINLP problem based on the superstructure is used to find out an optimal RO network which will minimize the total annualized cost while fulfilling a given boron content limit. The effect of pH on boron rejection is investigated at deferent seawater temperatures. The optimal operation policy of RO system is then studied in this work considering variations in freshwater demand and with changing seawater temperature throughout the day. A storage tank is added to the RO layout to provide additional operational flexibility and to ensure the availability of freshwater at all times. Two optimization problems are solved incorporating two seawater temperature profiles, representing summer and winter seasons. The possibility of flexible scheduling of cleaning and maintenance of membrane modules is investigated. Then, the optimal design and operation of RO process is studied in the presence of membrane fouling and including several operational variations such as variable seawater temperature. The cleaning schedule of single stage RO process is formulated as MINLP problem using spiral wound modules. NNs based correlation has been developed based on the actual fouling data which can be used for estimating the permeability decline factors. The correlation based on actual data to predict the annual seawater temperature profile is also incorporated in the model. The proposed optimization procedure identified simultaneously the optimal maintenance schedule of RO network including its design parameters and operating policy. The steady state model of RO process is used to study the sensitivity of different operating and design parameters on the plant performance. A non-linear optimization problem is formulated to minimize specific energy consumption at fixed product flow rate and quality while optimizing the design and operating parameters. Then the MINLP formulation is used to find the optimal designs of RO layout for brackish water desalination. A variable fouling profile along the membrane stages is introduced to see how the network design and operation of the RO system are to be adjusted Finally, a preliminary control strategy for RO process is developed based on PID control algorithm and a first order transfer function (presented in the Appendix).
    • Optimising Turnaround Maintenance (TAM) Scheduling of Gas plants in Libya

      Khan, M. Khurshid; Munive-Hernandez, J. Eduardo; El Werfalli, Abdelnaser A.K.
      Gas plants consist of several pieces of both critical static and rotating equipment, which operate continuously under severe operating conditions. These pieces of equipment are permanently subjected to be inspected and maintained during total shutdown of plant facilities to execute Turnaround Maintenance (TAM) event. The TAM is the largest maintenance activities used in most oil and gas companies in terms of both cost and time. Oil and gas companies have suffered losses in the production and enormity in the TAM cost due to duration and interval of TAM which have randomly estimated without taking the size and age of plants into account. Sirte Oil Company (SOC) was a good example and used as a reference point for other gas plants to achieve the aim of this thesis associated with optimising TAM scheduling for gas plants (decreasing duration and increasing interval of TAM) by implementing the TAM model. The contribution of this research is in developing the TAM model, consisting of four stages, which is broken down into four main stages: First stage; removing Non-critical pieces of Equipment (NEs) from the Scope of Work (SoW) of TAM to proactive maintenance strategies. Second stage; selecting Critical Static pieces of Equipment (CSEs) that constitute the highest risk based on Risk-Based Inspection (RBI). Third stage; selecting Critical Rotating pieces of Equipment (CREs) that constitute the highest risk based on Risk-Based Failure (RBF). Fourth stage; defining the optimum duration and interval of TAM based on Failure Distributions (FDs). Consequently, the TAM model developed in this study provides a novelty in the TAM event and decision making process. This is basically about optimisation of TAM scheduling in the medium and long-term, characterized by decreasing duration and increasing interval of TAM based on both CSEs and CREs to achieve the TAM model results. The result is the reduction in TAM cost and production losses, and the improvement in reliability and availability requirements of gas plants according to the residual life of critical equipment and operating conditions. To ensure reliability and consistency of the TAM model, it was validated with three Libya-plants SOC and data from three published case studies. The results from the validation of the TAM model are consistent with the real duration and interval of TAM in most plants SOC. The research concludes that the developed TAM model is a reliable and applicable tool to assist decision-makers in the estimation of TAM scheduling for any a processing plant.
    • The optimization of multiple antenna broadband wireless communications. A study of propagation, space-time coding and spatial envelope correlation in Multiple Input, Multiple Output radio systems

      Abd-Alhameed, Raed A.; Jones, Steven M.R.; Diameh, Yousef A. (University of BradfordSchool of Engineering, Design and Technology, 2014-05-30)
      This work concentrates on the application of diversity techniques and space time block coding for future mobile wireless communications. The initial system analysis employs a space-time coded OFDM transmitter over a multipath Rayleigh channel, and a receiver which uses a selection combining diversity technique. The performance of this combined scenario is characterised in terms of the bit error rate and throughput. A novel four element QOSTBC scheme is introduced, it is created by reforming the detection matrix of the original QOSTBC scheme, for which an orthogonal channel matrix is derived. This results in a computationally less complex linear decoding scheme as compared with the original QOSTBC. Space time coding schemes for three, four and eight transmitters were also derived using a Hadamard matrix. The practical optimization of multi-antenna networks is studied for realistic indoor and mixed propagation scenarios. The starting point is a detailed analysis of the throughput and field strength distributions for a commercial dual band 802.11n MIMO radio operating indoors in a variety of line of sight and non-line of sight scenarios. The physical model of the space is based on architectural schematics, and realistic propagation data for the construction materials. The modelling is then extended and generalized to a multi-storey indoor environment, and a large mixed site for indoor and outdoor channels based on the Bradford University campus. The implications for the physical layer are also explored through the specification of antenna envelope correlation coefficients. Initially this is for an antenna module configuration with two independent antennas in close proximity. An operational method is proposed using the scattering parameters of the system and which incorporates the intrinsic power losses of the radiating elements. The method is extended to estimate the envelope correlation coefficient for any two elements in a general (N,N) MIMO antenna array. Three examples are presented to validate this technique, and very close agreement is shown to exist between this method and the full electromagnetic analysis using the far field antenna radiation patterns.
    • Organic residue analysis of Red Lustrous Wheelmade Ware vessels traded across the eastern Mediterranean during the Late Bronze Age

      Steele, Valerie J.; Stern, Ben
      Red Lustrous Wheelmade Ware (RLWm ware) transport and storage vessels have been excavated from Late Bronze Age (LBA) sites across the eastern Mediterranean. These distinctive vessels were traded for the valuable commodity they contained so far unidentified. Seventy-three sherds (61 RLWm ware, 12 in local fabrics) and two visible residues were analysed for organic residues using standard lipid extraction techniques. Seven residues from a previous study were re-examined. Gas chromatography-mass spectrometry identified four materials ¿ beeswax, bitumen, fat/oil and resin. Beeswax, found only in vessels from Hittite sites in Turkey, was probably used as a post-firing treatment. Fat/oil, present in some sherds from every site, represents the contents of the vessels and showed many of the characteristics of degraded plant oil. Two examples contained a plant sterol and three yielded ricinoleic acid, a biomarker for castor oil. Gas-chromatography compound-specific isotope ratio mass spectrometry of selected residues excluded dairy products, ruminant animal fats and fish oils as source materials for the fats/oils, while comparison with a small database of modern oils created during this study does not exclude plant oils. Selected samples analysed by high performance liquid chromatography-tandem mass spectrometry did not reveal wine residues. Data on the elemental composition of the fabric collected during another study was re-analysed and compared with data from a further published study, confirming the remarkable consistency of RLWm ware fabric. Volume calculations were also attempted to give an estimate of the capacity of the main vessel forms.