Recent Submissions

  • An Empirical Analysis of Foreign Direct Investment in the Libyan Oil Industry

    Baimbridge, Mark J.; Abushhewa, Tarek (University of BradfordBradford University School of Management, 2008)
    This study investigates the major factors that have restricted the flow of foreign direct investment (FDI) into the oil sector in Libya. The study focuses on the period from 2000 to 2009. This period is significant since, during this time Libya witnessed dramatic foreign and economic policy changes. The research objectives are: (1) To identify the determinants of foreign direct investment into Libya’s oil industry for the period 2000-2009; (2) To reveal the obstacles and barriers which hinder FDI in Libya’s oil industry; (3) To determine the extent that the Libyan Government FDI policy influenced FDI in Libya’s oil industry. The rationale for this thesis was driven by filling an empirical void of FDI studies on the oil industry in Libya and by the intention of providing practical insights for current and future Libyan governments. This study comprises of an analysis of the 30 multinational (MNCs) oil companies that are operating in the Libyan oil industry through questionnaire and interview data from executives employed by those MNCs, as well as data from ten Libyan senior government officials involved in the Libyan oil industry and/or FDI policies. The research has provided support for several of the determinants of FDI flows traditionally found in the literature. The survey and time series analysis further reveals that access to Libya’s proven oil and gas reserves was the singular most important determinate for influencing the MNCs to undertake FDI. Furthermore, the findings identified that Libyan government foreign policy had some impact on the MNCs decision to undertake FDI. The research findings with regards to the role played by environmental risk as a determinate of FDI, demonstrate that there is no significant relationship between overall levels of environmental risk and a country‘s performance in attracting FDI. Also, this research has identified a number of factors that are causing obstacles and challenges to the attractiveness of Libya as a location for foreign investment. It has revealed that MNCs are significantly dissatisfied by the stability of the public institutions and the lack of effective regulations in Libya.
  • Military Intervention in Africa. External Military Interventions and Security Prospects in Africa

    Dando, Malcolm R.; O'Connell, James; Rogers, Paul F.; Bob-Manuel, Kio L. (University of BradfordSchool of Peace Studies, 1990)
    The research was an investigation into the phenomenon of external military interventions in Africa. The broad interpretation often given to intervention compelled both an African view on the subject and an operational definition. External military intervention was defined as the execution of any military plans by a state or its citizens in another state, in a manner that radically alters the existing socio-political, economic and military conditions in the target state, with or without its consent. The role and effects of external powers in six conflict cases in Africa were examined. A taxonomy on intervention identified the phenomenon in its internal and external manifestations. Apart from the more publicised military role of extra-African powers in the region, the increasing role of African States as intra-continental interventionists was also considered. The research concluded that aspects of the problems perceived as endemically African may have their roots in events influenced by external actions. However, some African states were seen as contributing to this situation as well. The view was expressed that restraints by states in their exercise of power and perceived wisdom may reduce the level of conflicts in the contemporary world.
  • Autoscaling through Self-Adaptation Approach in Cloud Infrastructure. A Hybrid Elasticity Management Framework Based Upon MAPE (Monitoring-Analysis-Planning-Execution) Loop, to Ensure Desired Service Level Objectives (SLOs)

    Kamala, Mumtaz A.; Qahwaji, Rami S.R.; Butt, Sarfraz S. (University of BradfordFaculty of Engineering and Informatics, 2019)
    The project aims to propose MAPE based hybrid elasticity management framework on the basis of valuable insights accrued during systematic analysis of relevant literature. Each stage of MAPE process acts independently as a black box in proposed framework, while dealing with neighbouring stages. Thus, being modular in nature; underlying algorithms in any of the stage can be replaced with more suitable ones, without affecting any other stage. The hybrid framework enables proactive and reactive autoscaling approaches to be implemented simultaneously within same system. Proactive approach is incorporated as a core decision making logic on the basis of forecast data, while reactive approach being based upon actual data would act as a damage control measure; activated only in case of any problem with proactive approach. Thus, benefits of both the worlds; pre-emption as well as reliability can be achieved through proposed framework. It uses time series analysis (moving average method / exponential smoothing) and threshold based static rules (with multiple monitoring intervals and dual threshold settings) during analysis and planning phases of MAPE loop, respectively. Mathematical illustration of the framework incorporates multiple parameters namely VM initiation delay / release criterion, network latency, system oscillations, threshold values, smart kill etc. The research concludes that recommended parameter settings primarily depend upon certain autoscaling objective and are often conflicting in nature. Thus, no single autoscaling system with similar values can possibly meet all objectives simultaneously, irrespective of reliability of an underlying framework. The project successfully implements complete cloud infrastructure and autoscaling environment over experimental platforms i-e OpenStack and CloudSim Plus. In nutshell, the research provides solid understanding of autoscaling phenomenon, devises MAPE based hybrid elasticity management framework and explores its implementation potential over OpenStack and CloudSim Plus.
  • Beyond the vessel: Organic residue analysis of Late Bronze and Early Iron Age south-east European pottery

    Armit, Ian; Stern, Ben; Heron, Carl P.; Büster, Lindsey S.; Bastos, Beatriz I.F. de (University of BradfordFaculty of Life Sciences: School of Archaeological and Forensic Sciences, 2019)
    The Encounters and Transformations in Iron Age Europe project (ENTRANS) aims to expand our knowledge regarding the nature and impact of cultural encounters during the European Iron Age. The study of ceramic vessels was included in the project, in order to further understand cultural practices in the south-east Alpine region. Organic residue analysis is an important tool in archaeological research for determining the presence of food and other organic substances associated with ceramic vessels. It has the potential to significantly improve our understanding of Iron Age societies and the interactions between them. This research focuses on the analysis of visible and absorbed organic residues from 377 ceramic vessels, from Late Bronze Age and Early Iron Age sites in Slovenia and Croatia, by gas-chromatography mass spectrometry. Two methods of lipid extraction were compared in a pilot study compressing 30 potsherds from Kaptol (solvent vs. acid extraction). This study revealed that more information was obtained by acid extraction, thus it was selected as the main method of extraction for this project. Differences between settlement, funerary and ritual sites were observed, suggesting that the vessels placed in the graves were not previously used or carried foodstuff with low lipid content, such as liquids and dry foods/cereals. Some types of residues were only identified in funerary vessels, specifically potential castor oil in Kaptol, mixed with other fats and oils. Lipid biomarkers and lipid ratios revealed significant differences between contexts and different sites, suggesting that the differences in cultural practices can also be identified in the use of ceramic vessels. Some residues were also sampled for gas-chromatography compound-specific isotope ratio mass spectrometry and bulk isotope analysis (only visible residues), which identified potential dairy fats in two potsherds from Poštela. The results were also compared with the contextual information, mainly the faunal remains, and the data obtained from the osteology and diet study preformed with individuals from the same area and chronology as the ceramic vessels.
  • Sedimentation and Consolidation of cohesive and non-cohesive soils formed under turbulent flows

    Mohamed, Mostafa H.A.; Pu, Jaan H.; Almabruk, Adam (University of BradfordFaculty of Engineering and Informatics, 2018)
    Settling and consolidation of suspended clay particles are significant issue in many fields such as geotechnical engineering, coastal and hydraulic engineering, and environmental engineering. A comprehensive literature review was conducted on the settling, consolidation and erosion of mixed soil material (cohesive and non-cohesive). Soil beds formed by sedimentation process of loose particles will be either show a segregated or homogeneous in structure, depending on the depositional environment. These sediments initially undergo self-weight consolidation and may be eroded under high flow rate. A number of studies have recently investigated the characteristic of consolidated clay bed in stagnant water. Hence, consolidation parameters were determined using a well-known vertical settling column consolidation test setup. However, limited research studies are available for deposition and consolidation of a mixture of sediment (clay, silt and sand) under flow conditions which are more representative of what happens in nature. A long flume and pump were used to create different turbulent conditions and simulate the natural process... The results for deposition and consolidation of different mixtures under stagnant and turbulence conditions were analyzed and compered in term of compressibility, permeability as well as shear strength. The results of this experimental research program indicated that the flow rate, initial concentration, height of settling and composition of sediment are all important factors that could affect the final bed dry unit weight. Two non-intrusive techniques were applied for measuring the dry unit weight at settling and consolidation stages. Impact echo technique has never been applied to measure the dry unit weight of self-weight consolidation along the vertical stratification of cohesive and non-cohesive particles. Also, a novel conductance sensor has been developed to improve the efficiency of this technique. The limitations of using these techniques will be highlighted in this study.
  • Effects of Graphene Oxide in vitro on DNA Damage in Human Whole Blood and Peripheral Blood Lymphocytes from Healthy individuals and Pulmonary Disease Patients: Asthma, COPD, and Lung Cancer

    Anderson, Diana; Najafzadeh, Mojgan; Amadi, Emmanuel E. (University of BradfordFaculty of Life Sciences, 2019)
    For the past few decades, the popularity of graphene oxide (GO) nanomaterials (NMs) has increased exceedingly due to their biomedical applications in drug delivery of anti-cancer drugs. Their unique physicochemical properties such as high surface area and good surface chemistry with unbound surface functional groups (e.g. hydroxyl - OH, carboxyl /ketone C=O, epoxy/alkoxy C-O, aromatic group C=C, etc) which enable covalent bonding with organic molecules (e.g. RNA, DNA) make GO NMs as excellent candidates in drug delivery nanocarriers. Despite the overwhelming biomedical applications, there are concerns about their genotoxicity on human DNA. Published genotoxicity studies on GO NMs were performed using non-commercial GO with 2-3 layers of GO sheets, synthesized in various laboratories with the potential for inter-laboratory variabilities. However, what has not been studied before is the effects of the commercial GO (15-20 sheets; 4-10% edge-oxidized; 1 mg/mL) in vitro on DNA damage in human whole blood and peripheral blood lymphocytes (PBL) from real-life patients diagnosed with chronic pulmonary diseases [asthma, chronic obstructive pulmonary disease (COPD), and lung cancer], and genotoxic endpoints compared with those from healthy control individuals to determine whether there are any differences in GO sensitivity. Thus, in the present study, we had characterized GO NMs using Zetasizer Nano for Dynamic Light Scattering (DLS) and zeta potential (ZP) in the aqueous solution, and electron microscopy using the Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) in the dry state, respectively. Cytotoxicity studies were conducted on human PBL from healthy individuals and patients (asthma, COPD, and lung cancer) using the Methylthiazolyldiphenyl-tetrazolium bromide (MTT) and Neutral Red Uptake (NRU) assays, respectively. The genotoxicity (DNA damage) and cytogenetic effects (chromosome aberration parameters) induced by GO NMs on human whole blood from healthy individuals and patients were studied using the Alkaline Comet Assay and Cytokinesis-blocked Micronucleus (CBMN) assay, respectively. Our results showed concentration-dependent increases in cytotoxicity, genotoxicity, and chromosome aberrations, with blood samples from COPD and lung cancer patients being more sensitive to DNA damage insults compared with asthma patients and healthy control individuals. Furthermore, the relative gene and protein expressions of TP53, CDKN1A/p21, and BCL-2 relative to GAPDH on human PBL were studied using the Reverse Transcription Quantitative Polymerase Chain Reaction (RT-qPCR) and Western Blot techniques, respectively. Our results have shown altered gene and protein expression levels. Specifically, GO-induced cytotoxicity, genotoxicity, and micronuclei aberrations were associated with TP53 upregulation - a biomarker of DNA damage - in both patients and healthy individuals. These effects show that GO NMs have promising roles in drug delivery applications when formulated to deliver drug payload to COPD and cancer cells. However, the fact that cytotoxicity, genotoxicity, chromosome instability, and gene/protein expressions - biomarkers of cancer risk - were observed in healthy individuals are of concern to public health, especially in occupational exposures at micro levels at the workplace.
  • The Impact of Institutions on Innovation: Three Empirical Studies

    Wang, Chengang; Trivedi, Rohitkumar; Sharma, Abhijit; Abdin, Joynal (University of BradfordAccounting, Finance and Economics Research Centre, Faculty of Management, Law and Social Sciences, 2020)
    This thesis carries out empirical investigations of the possible impacts of institutions relating to different aspects of innovation, namely incremental innovation activities, collaborative research and development (R&D) activities and radical innovation outcomes. It comprises three studies. The first empirical study focuses on examining the impact of financial constraints and intellectual property rights (IPR) protection on incremental innovation. Using firm-level data from transition countries and employing a two-step probit model with endogenous regressors, this study provides evidence that both financing constraints and strong IPR protection are negatively associated with the incremental innovation activities of firms. Results also confirm that financing constraints faced by firms are significantly influenced by the overall levels of development of financial institutions within a country. The second empirical study looks at the effects of contracting institutions and intellectual property institutions on firms’ collaborative research and development (R&D) activities in developing and transition countries. By employing the Cragg double-hurdle model, this study finds that efficient contract enforcement has a positive effect on the likelihood of firms engaging in R&D partnership and the intensity of firms' expenditures on collaborative R&D. On the other hand, the decision of firms to participate in R&D partnerships and their level of expenditure on collaborative R&D are adversely affected by the strength of IPR protection. The third empirical study investigates the influences of a set of institutions on producing new-to-the-world technologies, as measured by patents. This study is conducted by using a large panel dataset of 98 developed and developing countries over a period of 23 years. Building on the idea production framework, the unconditional quantile regression (UQR) estimates of this study show that along with key research inputs (i.e., existing knowledge stock and resources devoted to R&D), the strength of IPR protection, quality of governance and functioning of financial institutions are also significant determinants of the patent output of a country. The UQR methodology also demonstrates that the effects of institutions on patent production are heterogeneous throughout the various quantiles of patent output distribution. This thesis, therefore, offers an example of how the new institutional economics (NIE) theory is applicable in analysing innovation performances. The findings of this thesis propose useful policy directions that can assist policymakers and managers in accelerating innovation and technological development.
  • Cyber Attack Modelling using Threat Intelligence. An investigation into the use of threat intelligence to model cyber-attacks based on elasticsearch and honeypot data analysis

    Awan, Irfan U.; Al-Mohannadi, Hamad (University of BradfordSchool of Electrical Engineering and Computer Science, 2019)
    Cyber-attacks have become an increasing threat to organisations as well as the wider public. This has led to greatly negative impacts on the economy at large and on the everyday lives of people. Every successful cyber attack on targeted devices and networks highlights the weaknesses within the defense mechanisms responsible for securing them. Gaining a thorough understanding of cyber threats beforehand is therefore essential to prevent potential attacks in the future. Numerous efforts have been made to avoid cyber-attacks and protect the valuable assets of an organisation. However, the most recent cyber-attacks have exhibited the profound levels of sophistication and intelligence of the attacker, and have shown conven- tional attack detection mechanisms to fail in several attack situations. Several researchers have highlighted this issue previously, along with the challenges faced by alternative solu- tions. There is clearly an unprecedented need for a solution that takes a proactive approach to understanding potential cyber threats in real-time situations. This thesis proposes a progressive and multi-aspect solution comprising of cyber-attack modeling for the purpose of cyber threat intelligence. The proposed model emphasises on approaches from organisations to understand and predict future cyber-attacks by collecting and analysing network events to identify attacker activity. This could then be used to understand the nature of an attack to build a threat intelligence framework. However, collecting and analysing live data from a production system can be challenging and even dangerous as it may lead the system to be more vulnerable. The solution detailed in this thesis deployed cloud-based honeypot technology, which is well-known for mimicking the real system while collecting actual data, to see network activity and help avoid potential attacks in near real-time. In this thesis, we have suggested a new threat intelligence technique by analysing attack data collected using cloud-based web services in order to identify attack artefacts and support active threat intelligence. This model was evaluated through experiments specifically designed using elastic stack technologies. The experiments were designed to assess the identification and prediction capability of the threat intelligence system for several different attack cases. The proposed cyber threat intelligence and modeling systems showed significant potential to detect future cyber-attacks in real-time.
  • Surface engineering, characterisation and applications of synthetic polymers for tissue engineering and regenerative medicine. Investigation of the response of MG63 osteosarcoma cell line to modified surface topographies, mechanical properties and cell-surface interactions using different synthetic polymers fabricated in house with various topographical features

    Youseffi, Mansour; Sefat, Farshid; Katsikogianni, Maria G.; Rehman, Ramisha U. (University of BradfordBiomedical and Electronics Engineering Department, Faculty of Engineering and Informatics, 2019)
    At present there is an extraordinary need to overcome barriers in regards to discovering novel and enhanced biomaterials for various tissue engineering applications. The need for durable orthopaedic implants is on the rise to limit issues such as revision surgery. A promising pathway to enhance fixation is to accelerate the onset and rate of early cellular adhesion and bone growth through nanoscale surface topography at the implant surface. The main aim of this research project was to investigate cellular response to altered physical and mechanical characteristics of materials suitable for orthopaedic applications. Four injection moulded polymeric substrates were produced, each with varied compositional and topographical characteristics. The four materials fabricated are Polyether-ether-ketone (PEEK), PEEK with 30% glass fibre (GL/PEEK) composite, PEEK and GL/PEEK with grooved topography. SEM and AFM analysis was used to investigate the groove dimensions and surface roughness of all samples followed by mechanical testing using a nano indenter to detect the Young’s modulus, stiffness and hardness of all four substrates. These tests were performed to determine which material has similar characteristics to cortical bone. These tests were followed by wettability and surface energy testing. Cell-substrate adhesion was examined using a cell viability assay to identify if there is a significant difference (p<0.05) between the percentage of viable cells on all four PEEK based materials. Imaging of MG-63 osteosarcoma cells using immunohistochemistry staining kits was conducted to observe the relationship between cell length and surface topography followed by a comparison between HaCaT (skin) cells and MG-63 (bone) cells. Following experimental testing mechanical variations between PEEK and GL/PEEK were identified alongside physical characterization differences. The grooved topography increased the surface roughness of PEEK and GL/PEEK in comparison to the planar surface. After 72 hours a correlation between the increased surface roughness and the percentage of viable MG-63 cells could be identified. When assessing the effect surface topography has on the water contact angles and surface energy, all four substrates showed no correlation. However, the grooved topography did increase the water contact angle and reduced the surface energy of PEEK in comparison to planar PEEK. Images of the four substrates after cell culture observed the grooved topography to affect the cellular orientation of both MG-63 and HaCaT cells. Polycaprolactone (PCL) scaffolds with a concentration of 1, 3, and 5% triclosan (an antimicrobial and antifungal agent) were fabricated using electrospinning. In addition to PCL + Triclosan scaffolds PCL with a concentration of 1% silver (an antimicrobial agent that can reduce the risk of infection) and 1, 3, and 5% triclosan were also electrospun. The pore size and fibre diameters of the scaffolds were investigated using SEM and Image J software followed by wettability and surface energy testing. MG-63 cells were cultured on all PCL scaffolds to study cellular viability percentage after 24 and 72 hours. The findings obtained showed the physical characteristics of PCL scaffolds to affect cellular viability of MG-63 cells. The output from these findings aim to provide data at a proof of concept level in understanding the relationship between the mechanical and physical characteristics of biomaterials and cellular behaviour.
  • Making the most of time: A Grounded Theory to explain what facilitates nursing home staff to connect with residents living with advanced dementia

    Downs, Murna G.; Oyebode, Jan R.; Haunch, Kirsty J. (University of BradfordFaculty of Health Studies, 2018)
    Background: People living with advanced dementia in nursing homes often spend the majority of time alone, with little contact with anyone. The need to connect with others is a central part of a philosophy known as Person Centred Dementia Care. A significant body of literature demonstrates the effectiveness of a range of approaches that facilitate connections, yet, we know little about staff perspectives on what facilitates them to connect on a daily basis. Aim: To develop a Grounded Theory to explain what facilitates nursing home staff to connect with residents living with advanced dementia. Methods: Semi structured interviews were conducted with nursing home staff (n=21) and relatives (n=5) from seven nursing homes. Following Strauss and Corbin’s (1990, 1998) Interpretivist Grounded Theory methodology, data collection and analysis proceeded iteratively, and theoretical sampling was used to develop the emergent theory. Results: The Grounded Theory ‘making the most of time’ explains that most connections occurred during personal care. Interdependent contextual and individual factors facilitated staff to make the most of time. Effective leaders were described to create a caring culture in which informal leaders (experienced staff) acted as role models. Staff were then more likely to understand, accept and tolerate dementia, know connections were part of their role, get to know residents and express caring values. In the right physical environment, this then facilitated staff to make the most of time during personal care. Increased training and education from specialised dementia units and experiential knowledge from family engagement then supplement such contexts. Implications: Future research could empirically test the theory ‘making the most of time’
  • Energy storage in the future smart grid. An investigation of pricing strategies and dynamic load levelling for efficient integration of domestic energy storage within a virtual power plant and its evaluation using a genetic algorithm optimization platform

    Rajamani, Haile S.; Abd-Alhameed, Raed A.; Okpako, Oghenovo (University of BradfordSchool of Engineering and Informatics, 2019)
    One feature that is hoped for in the smart grid is the participation of energy prosumers in a power market through demand response program. In this work, we consider a third-party virtual power plant (VPP) that has “real-time” control over a number of prosumers’ storage units within an envisaged free market. Typically, a VPP with domestic energy storage will involve a bidirectional flow of energy, where energy can either flow from the grid to the prosumers’ battery or from the prosumers’ battery to the grid. Such a system requires prices to be set correctly in order to meet the market objectives of all the VPP stakeholders (VPP Aggregator, prosumers, and grid). Previous work has shown how VPPs could operate, and the benefits of using energy storage, coupled with pricing, in terms of reducing energy cost for stakeholders and providing the grid with its required load shape. The published work either assumes prices or costs or then optimises for least cost within the grid parameters i.e. losses, voltage limits, etc. However, the setting of prices in such a way that energy can be traded among VPP stakeholders that satisfies all stakeholders’ objectives has not been fully explored in the literature, particularly with real-time VPP aggregators. In this thesis, we present novel strategies for evaluating and setting the prices of a community VPP with domestic storage based on the bidirectional flow of energy through the VPP aggregator between the grid and the prosumers that mutually meet all VPP stakeholders’ objectives. This showed that depending on pricing and the VPP objectives, demand-side management could be attractive. However, the effect on the grid in terms of the load was not what was desired. A new performance index called the “Cumulative Performance Index” CPI is proposed to measure the VPP’s performance. Using the CPI, it was possible to compare and contrast between the VPP technical performance and its business case for stakeholders. Optimizing with respect to the grid’s requirement for DSM from the VPP, it was possible to achieve a CPI of 100%. This work was implemented using a novel approach on a genetic algorithm platform.
  • User Acceptance Evaluation of E-Government Services, Impact of Unified Approach Framework on the Government. Cloud Sultanate of Oman as a Case Study; Government and Citizens Perspectives

    Kamala, Mumtaz A.; Qahwaji, Rami S.R.; Al Shaidy, Al Noaman M.K. (University of BradfordDepartment of Computing Faculty of Engineering and Informatics, 2019)
    Oman has adopted e-government services, but according to the United Nations E-Government Development Index classification, such services are not fully utilised. E-government classification of Oman shows a lack that motivated this research. The aim is to provide a framework that can help the Omani government to better implement e-government services. As a result, Oman classification is expected to be improved. Such framework may also help similar developing countries in implementing their e-government services. This work aimed to address both; government and citizens prospective, also aiming to help conducting a sold research a good implementable framework. Therefore, an interview with 21 government participations from different institutions was conducted followed by citizens that attracted 400 qualified responses. The research process has led to the suggestion of using another approach of e-government services, the unified e-services portals. The outcomes of this research show; both government and citizens are in favour of using unified definitions in portals. In addition, a proposed framework is presented based on supported findings that is believed to better utilising e government services hence leading to improve ranking. It is also believed that the UN assessing committees would benefit from the unified approach. Simply, it unifies the definition of each service based on the published academic definitions and work. The evaluation of the proposed framework is outside this research and can be addressed by a further research as recommended. Implementing the unified approach portals is another front that attracts implementation and evaluation.
  • Experimental investigations and finite element analyses of interface heat partition in a friction brake system. New modelling paradigm for describing friction brake systems to support studies of interface temperature, contact pressure, heat flux distribution and heat partition ratio by experiment and FE simulation

    Qi, Hong Sheng; Wood, Alastair S.; Qui, Le (University of BradfordFaculty of Engineering and Informatics, 2018)
    Operating temperature range is one of the primary design considerations for developing effective disc brake system performance. Very high braking temperatures can introduce effects detrimental to performance such as brake fade, premature wear, brake fluid vaporization, bearing failure, thermal cracks, and thermally-excited vibration [2]. This project is concerned with investigating deficiencies and proposing improvements in brake system Finite Element (FE) models in order to provide high quality descriptions of thermal behaviour during braking events. The work focuses on brake disc/pad models and the degree of rotational freedom allowed for the pad. Conventional models [10] allow no motion/or free motion of the pad. The present work investigates the effect on disc/pad interface temperature and pressure distributions of limited relaxations of this rotational restriction. Models are proposed, developed and validated that facilitate different rotational degrees of freedom (DoF) of the pad. An important influencing factor in friction brake performance is the development of an interface tribo-layer (ITL). It is reasonable to assume that allowing limited rotational motion of the pad will impact the development of the ITL (e.g. due to different friction force distributions) and hence influence temperature. Here the ITL is modelled in the numerical simulations as a function of its thickness distribution and thermal conductivity. Different levels of ITL thermal conductivity are defined in this work and results show that conductivity significantly a1qwffects interface temperature and heat partition ratio. The work is based around a set of test-rig experiments and FE model developments and simulations. For the experimental work, a small-scale test rig is used to investigate the friction induced bending moment effect on the pad/disc temperature. Significant non-uniform wear is observed across the friction surface of the pad, and reasons for the different wear rates are proposed and analyzed together with their effect on surface temperature. Following on from experiment a suite of models is developed in order to evidence the importance of limited pad motion and ITL behaviours. A 2D coupled temperature-displacement FE model is used to quantify the influence of different pad rotational degrees of freedom and so provide evidence for proposing realistic pad boundary settings for 3D models. Normal and high interface thermal conductance is used in 2D models and results show that the ITL thermal conductivity is an important factor influencing the maximum temperature of contact surfaces and therefore brake performance. The interface heat partition ratio is calculated by using the heat flux results and it is confirmed that this value is neither constant nor uniform across the interface surfaces. Key conclusions from the work are (i) that ITL thermal conductivity is an important factor influencing the interface temperature/heat flux distribution and their maximum values, (ii) that allowed motion of the pad significantly affects the interface pressure distribution and subsequently the temperature distribution, (iii) that the transient heat partition in friction braking is clearly quite different to the conventional friction-pair steady heat partition (the heat partition ratio is not uniformly distributed along the interface) and (iv) that the thickness of the ITL increases through braking events, reducing the heat transfer to the disc, and so providing a possible explanation for increasing pad temperature observed over the life time of a brake pad.
  • Prostanoid-mediated Inhibition of IL-6 Trans-Signalling in Pulmonary Arterial Hypertension: a Role for Suppressor of Cytokine Signalling 3?

    Palmer, Timothy M.; Williams, Jamie J.L.; Nasim, Md. Talat; Elies, Jacobo; Durham, Gillian A. (University of BradfordSchool of Pharmacy and Medical Sciences Faculty of Life Sciences, 2019)
    Pulmonary arterial hypertension (PAH) is a rare, devastating disease with no cure. Current treatment consists of a cocktail of vasodilators which relieve symptoms of PAH but do not treat the cause. Thus, there is a need for novel drugs that target the underlying pathological causes of PAH. PAH is a multi-factorial, but one key contributor is the pro-inflammatory cytokine IL-6 which stimulates pro-inflammatory and pro-angiogenic signalling mediated by the JAK/STAT pathway. One way in which IL-6 signalling via JAK/STAT is inhibited is via SOCS3 in a type of negative feedback loop whereby IL-6 induces transcription of SOCS3, which then attenuates further JAK/STAT signalling. SOCS3 can also be induced by cAMP. This is interesting as prostanoids, a type of drug used in the treatment of PAH due to its vasodilator effects and the only type to show any efficacy improving the life expectancy of PAH patients, acts by mobilising cAMP. Thus, prostanoid stimulation of cAMP could potentially limit IL-6 signalling via the induction of SOCS3. This is a novel mechanism of prostanoids which has not previously been considered. This study investigated the capability of prostanoids to limit the pro-inflammatory/pro-angiogenic effects of IL-6 that enable PAH to develop. Initial experiments confirmed that vascular endothelial cells responded to prostanoids which increased SOCS3 and limited IL-6 signalling activity. Further experiments utilising SOCS3 KO endothelial cell models demonstrated prostanoid inhibition of IL-6 signalling was due in part to SOCS3. In conclusion, this project has confirmed that prostanoids do limit the pro-inflammatory effects induced by IL-6 and that this is in part due to SOCS3. Although the exact mechanism is yet to be discovered, it will be beneficial in the treatment of PAH as it provides currently unexploited drug targets which can be considered for future PAH therapies.
  • Managing risk; how doctors, nurses and pharmacists optimise the use of medicines in acute hospitals in Northern Ireland: a grounded theory study.

    Lucas, Beverley J.; Blenkinsopp, Alison; Friel, Anne B.M. (University of BradfordSchool of Pharmacy and Medical Sciences, Faculty of Life Sciences, 2018)
    Medicines optimisation requires healthcare professionals to work collaboratively to meet the medication needs of patients. A grounded theory was produced which explains how doctors, nurses and pharmacists work to optimise the use of medicines in acute hospital settings in Northern Ireland. Seventeen semi-structured, one-to-one interviews were conducted with doctors, nurses and pharmacists. Concurrent data collection and analysis was carried out using coding, particular to grounded theory, adopting a constant comparative approach, writing memos and using theoretical sampling as described by Strauss and Corbin (1998). The core category was managing risk. Participants had an implicit understanding of the need to continually manage risk when working with the complex and the routine. They used personal and systemic checks and balances which could be viewed either as duplication of effort or indicative of a culture of safety. Multi-professional interdependencies and support for new, professional, non-medical roles were highlighted. Working together was a further strategy to ensuring each patient gets the right medicine. Establishing an agreed framework for working with medicines at ward level could support the safer use of medicines. It is anticipated that this theory will contribute to the design of systems involved in medicines use in acute hospitals in Northern Ireland.
  • Development of digital imaging technologies for the segmentation of solar features and the extraction of filling factors from SODISM images

    Qahwaji, Rami S.R.; Ipson, Stanley S.; Alasta, Amro F.A. (University of BradfordSchool of Electrical Engineering and computer. Science Faculty of Engineering and Informatics, 2018)
    Solar images are one of the most important sources of available information on the current state and behaviour of the sun, and the PICARD satellite is one of several ground and space-based observatories dedicated to the collection of that data. The PICARD satellite hosts the Solar Diameter Imager and Surface Mapper (SODISM), a telescope aimed at continuously monitoring the Sun. It has generated a huge cache of images and other data that can be analysed and interpreted to improve the monitoring of features, such as sunspots and the prediction and diagnosis of solar activity. In proportion to the available raw material, the little-published analysis of SODISM data has provided the impetus for this study, specifically a novel method of contributing to the development of a system to enhance, detect and segment sunspots using new hybrid methods. This research aims to yield an improved understanding of SODISM data by providing novel methods to tabulate a sunspot and filling factor (FF) catalogue, which will be useful for future forecasting activities. The developed technologies and the findings achieved in this research will work as a corner stone to enhance the accuracy of sunspot segmentation; create efficient filling factor catalogue systems, and enhance our understanding of SODISM image enhancement. The results achieved can be summarised as follows: i) Novel enhancement method for SODISM images. ii) New efficient methods to segment dark regions and detect sunspots. iii) Novel catalogue for filling factor including the number, size and sunspot location. v) Novel statistical method to summarise FFs catalogue. Image processing and partitioning techniques are used in this work; these methods have been applied to remove noise and detect sunspots and will provide more information such as sunspot numbers, size and filling factor. The performance of the model is compared to the fillers extracted from other satellites, such as SOHO. Also, the results were compared with the NOAA catalogue and achieved a precision of 98%. Performance measurement is also introduced and applied to verify results and evaluate proposal methods. Algorithms, implementation, results and future work have been explained in this thesis.
  • Design and Linearization of Energy Efficiency Power Amplifier in Nonlinear OFDM Transmitter for LTE-5G Applications. Simulation and measurements of energy efficiency power amplifier in the presence of nonlinear OFDM transmitter system and digital predistortion based on Hammerstein-Wiener method

    Abd-Alhameed, Raed A.; Mohammed, Buhari A. (University of BradfordFaculty of Engineering and Informatics, 2019)
    This research work has made an effort to understand a novel line of radio frequency power amplifiers (RFPAs) that address initiatives for efficiency enhancement and linearity compensation to harmonize the fifth generation (5G) campaign. The objective is to enhance the performance of an orthogonal frequency division multiplexing-long term evolution (OFDM-LTE) transmitter by reducing the nonlinear distortion of the RFPA. The first part of this work explores the design and implementation of 15.5 W class AB RF power amplifier, adopting a balanced technique to stimulate efficiency enhancement and redeeming exhibition of excessive power in the transmitter. Consequently, this work goes beyond improving efficiency over a linear RF power amplifier design; in which a comprehensive investigation on the fundamental and harmonic components of class F RF power amplifier using a load-pull approach to realise an optimum load impedance and the matching network is presented. The frequency bandwidth for both amplifiers was allocated to operate in the 2.620-2.690 GHz of mobile LTE applications. The second part explores the development of the behavioural model for the class AB power amplifier. A particular novel, Hammerstein-Wiener based model is proposed to describe the dynamic nonlinear behaviour of the power amplifier. The RF power amplifier nonlinear distortion is approximated using a new linear parameter approximation approach. The first and second-order Hammerstein-Wiener using the Normalised Least Mean Square Error (NLMSE) algorithm is used with the aim of easing the complexity of filtering process during linear memory cancellation. Moreover, an enhanced adaptive Wiener model is proposed to explore the nonlinear memory effect in the system. The proposed approach is able to balance between convergence speed and high-level accuracy when compared with behavioural modelling algorithms that are more complex in computation. Finally, the adaptive predistorter technique is implemented and verified in the OFDM transceiver test-bed. The results were compared against the computed one from MATLAB simulation for OFDM and 5G modulation transmitters. The results have confirmed the reliability of the model and the effectiveness of the proposed predistorter.
  • The Organic Material Culture of Western Ulster: An Ethno-historical and Heritage Science Approach

    Croucher, Karina T.; Wilson, Andrew S.; McElhinney, Peter J. (University of BradfordFaculty of Life Sciences, 2019)
    This research attempts to describe the material culture of the Gaelic labouring classes living in western Ulster in the Late Medieval period. The research combines ethnohistorical contextual and technical scientific analysis of ‘chance’ finds discovered in the region’s bogs. Technical analysis dates fifteen museum objects, characterises the materials from which they were made, and explores their cultural significance. Absolute dating indicates that one third of the 15 objects analysed relate to the Gaelic lordships of late medieval western Ulster, with the remainder reflecting aspects of Iron Age and Post-Medieval material culture and related cultural pracrices. Contextual analysis of the later medieval objects and their find locations provides new insights into Gaelic Irish culture and landscape interactions in this period and place. In addition, the research explores the trajectory of indigenous materiality in western Ulster beyond the Late Medieval period. To this end, the thesis examines the relationship between Late Medieval indigenous materiality, and the folk material culture that emerges in western Ulster in the Modern period.
  • Performance Analysis of Virtualisation in a Cloud Computing Platform. An application driven investigation into modelling and analysis of performance vs security trade-offs for virtualisation in OpenStack infrastructure as a service (IaaS) cloud computing platform architectures.

    Kouvatsos, Demetres D.; Kiran, Miriam; Kamala, Mumtaz A.; Maiyama, Kabiru M. (University of BradfordDepartment of Computer Science, Faculty of Engineering and Informatics, 2019)
    Virtualisation is one of the underlying technologies that led to the success of cloud computing platforms (CCPs). The technology, along with other features such as multitenancy allows delivering of computing resources in the form of service through efficient sharing of physical resources. As these resources are provided through virtualisation, a robust agreement is outlined for both the quantity and quality-of-service (QoS) in a service level agreement (SLA) documents. QoS is one of the essential components of SLA, where performance is one of its primary aspects. As the technology is progressively maturing and receiving massive acceptance, researchers from industry and academia continue to carry out novel theoretical and practical studies of various essential aspects of CCPs with significant levels of success. This thesis starts with the assessment of the current level of knowledge in the literature of cloud computing in general and CCPs in particular. In this context, a substantive literature review was carried out focusing on performance modelling, testing, analysis and evaluation of Infrastructure as a Service (IaaS), methodologies. To this end, a systematic mapping study (SMSs) of the literature was conducted. SMS guided the choice and direction of this research. The SMS was followed by the development of a novel open queueing network model (QNM) at equilibrium for the performance modelling and analysis of an OpenStack IaaS CCP. Moreover, it was assumed that an external arrival pattern is Poisson while the queueing stations provided exponentially distributed service times. Based on Jackson’s theorem, the model was exactly decomposed into individual M/M/c (c ≥ 1) stations. Each of these queueing stations was analysed in isolation, and closed-form expressions for key performance metrics, such as mean response time, throughput, server (resource) utilisation as well as bottleneck device were determined. Moreover, the research was extended with a proposed open QNM with a bursty external arrival pattern represented by a Compound Poisson Process (CPP) with geometrically distributed batches, or equivalently, variable Generalised Exponential (GE) interarrival and service times. Each queueing station had c (c ≥ 1) GE-type servers. Based on a generic maximum entropy (ME) product form approximation, the proposed open GE-type QNM was decomposed into individual GE/GE/c queueing stations with GE-type interarrival and service times. The evaluation of the performance metrics and bottleneck analysis of the QNM were determined, which provided vital insights for the capacity planning of existing CCP architectures as well as the design and development of new ones. The results also revealed, due to a significant impact on the burstiness of interarrival and service time processes, resulted in worst-case performance bounds scenarios, as appropriate. Finally, an investigation was carried out into modelling and analysis of performance and security trade-offs for a CCP architecture, based on a proposed generalised stochastic Petri net (GSPN) model with security-detection control model (SDCM). In this context, ‘optimal’ combined performance and security metrics were defined with both M-type or GE-type arrival and service times and the impact of security incidents on performance was assessed. Typical numerical experiments on the GSPN model were conducted and implemented using the Möbius package, and an ‘optimal’ trade-offs were determined between performance and security, which are crucial in the SLA of the cloud computing services.
  • Rethinking the design and implementation of financial services for poverty reduction: A case of Northern Ghana

    Arora, Rashmi; Anand, Prathivadi B.; Naab, Gilbert Z. (University of BradfordFaculty of Management, Law and Social Sciences, 2019)
    The thesis empirically examines how microfinance products are designed and implemented, and the implications for clients’ households and sources of livelihood. The study argues that the design of products and implementation that reflect the livelihood needs and poverty context of clients is one of the effective ways to reduce poverty. It investigates the microfinance operations of three financial institutions: Sinapi Aba Trust (SAT), St Joseph’s Cooperative Credit Union (CCU) and Sonzele Rural Bank (SRB) in Jirapa, a municipality in Northern Ghana. The study deployed a mixed-methods approach to collect data from six rural and urban communities. Data was sought from secondary sources, 20 interviews, 10 focus group discussions and 120 questionnaires. The research adopted the Sustainable Livelihoods and the Making Markets Work for the Poor approaches as a guide in the framework of analysis. The study, using qualitative and quantitative analytical tools found that product designs of SAT and SRB did not reflect the needs and poverty context of the majority of their clients. Clients of SAT and SRB were found to be less involved in the product design processes, suggesting a top-down institutional approach that seldom incorporated the needs of the poor. The method of group formation has a substantial implication on members’ poverty outcomes. Groups involving only females had a significant and positive relationship with members’ household and business outcomes, while members of male-only groups had a negative relationship with their household outcomes. The thesis concludes that accessible interest on loans and incentives to encourage savings would make microfinance markets work more sustainably for the rural poor. The findings challenge a reconsideration of the design of microfinance products to integrate financial technology as an efficient approach to deliver financial services, especially in rural areas.

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