• Ultra-wideband antenna design for microwave imaging applications. Design, optimisation and development of ultra-wideband antennas for microwave near-field sensing tools, and study the matching and radiation purity of these antennas within near field environment.

      Abd-Alhameed, Raed A.; McEwan, Neil J.; Adnan, S. (University of BradfordSchool of Engineering, Design and Technology, 2013-12-05)
      Near field imaging using microwave in medical applications has gain much attention recently as various researches show its high ability and accuracy in illuminating object comparing to the well-known screening tools such as Magnetic Resonance Imaging (MRI), digital mammography, ultrasound etc. This has encourage and motivate scientists continue to exploit the potential of microwave imaging so that a better and more powerful sensing tools can be developed. This thesis documents the development of antenna design for microwave imaging application such as breast cancer detection. The application is similar to the concept of Ground Penetrating Radar (GPR) but operating at higher frequency band. In these systems a short pulse is transmitted from an antenna to the medium and the backscattered response is investigated for diagnose. In order to accommodate such a short pulse, a very wideband antenna with a minimal internal reflection is required. Printed monopole and planar metal plate antenna is implemented to achieve the necessary operating wide bandwidth. The development of new compact printed planar metal plate ultra wide bandwidth antenna is presented. A generalized parametric study is carried out using two well-known software packages to achieve optimum antenna performance. The Prototype antennas are tested and analysed experimentally, in which a reasonable agreement was achieved with the simulations. The antennas present an excellent relative wide bandwidth of 67% with acceptable range of power gain between 3.5 to 7 dBi. A new compact size air-dielectric microstrip patch-antenna designs proposed for breast cancer detection are presented. The antennas consist of a radiating patch mounted on two vertical plates, fed by coaxial cable. The antennas show a wide bandwidth that were verified by the simulations and also confirmed experimentally. The prototype antennas show excellent performance in terms the input impedance and radiation performance over the target range bandwidth from 4 GHz to 8 GHz. A mono-static model with a homogeneous dielectric box having similar properties to human tissue is used to study the interaction of the antenna with tissue. The numerical results in terms the matching required of new optimised antennas were promising. An experimental setup of sensor array for early-stage breast-cancer detection is developed. The arrangement of two elements separated by short distance that confined equivalent medium of breast tissues were modelled and implemented. The operation performances due to several orientations of the antennas locations were performed to determine the sensitivity limits with and without small size equivalent cancer cells model. In addition, a resistively loaded bow tie antenna, intended for applications in breast cancer detection, is adaptively modified through modelling and genetic optimisation is presented. The required wideband operating characteristic is achieved through manipulating the resistive loading of the antenna structure, the number of wires, and their angular separation within the equivalent wire assembly. The results show an acceptable impedance bandwidth of 100.75 %, with a VSWR < 2, over the interval from 3.3 GHz to 10.0 GHz. Feasibility studies were made on the antenna sensitivity for operation in a tissue equivalent dielectric medium. The simulated and measured results are all in close agreement.
    • Ultrasound Assisted Processing of Solid State Pharmaceuticals. The application of ultrasonic energy in novel solid state pharmaceutical applications, including solvent free co-crystallisation (SFCC) and enhanced compressibility

      Kelly, Adrian L.; Paradkar, Anant R.; Brown, Elaine C.; Alwati, Abdolati A.M. (University of BradfordFaculty of Life Sciences, 2017)
      The objective of this study was to develop a new method for co-crystal preparation which adhered to green chemistry principles, and provided advantages over conventional methods. A novel, solvent-free, high-power ultrasound (US) technique, for preparing co-crystals from binary systems, was chosen as the technology which could fulfil these aims. The application of this technology for solid state co-crystal preparation was explored for ibuprofen-nicotinamide (IBU-NIC), carbamazepine-nicotinamide (CBZ-NIC) and carbamazepine-saccharin (CBZ-SAC) co-crystals. The effect of different additives and processing parameters such as power level, temperature and sonication time on co-crystallisation was investigated. Characterisation was carried out using DSC, PXRD, FTIR, Raman and HPLC. In addition, an NIR prediction model was developed and combined with multivariate analysis (PLS) and chemometric pre-treatments. It was found to be a robust, reliable and rapid method for the determination of co-crystal purity for the IBU-NIC and CBZ-NIC pairs. Co-crystal quantification of US samples helped to optimise the US method. Finally, a model formulation of paracetamol containing 5% and 10% PEG 8000 was ultrasonicated at maximum power with different exposure times. A comparison of technological and physicochemical properties of the resulting tablets with those of the tablets obtained using the pressing method evidenced significant differences. This suggested that US energy dissipation (mechanical and thermal effects) was the main mechanism which caused the PAR form I tabletability to improve. It was found that the ultrasound–compacted tablets released the drug at a slower rate compared to pure PAR. This technique was shown to be useful for improving tabletability for low-compressible drugs without the need to use a conventional tabletting machine.
    • Understanding account management in professional services relationships. Conceptualising a value framework of account management from client and professional perspective in the audit, tax and management consultancy industry.

      Not named; Van Bon, Hendrikus Johannes (University of BradfordDepartment of School of Management, 2013-12-18)
      Professionals take centre stage in the delivery of professional services and the role of account management has received little research attention. This thesis concerns the value of account management in professional service relationships in the audit, tax and management consultancy industry, contextualising the nature and value of account management through client and professional perspectives. It addresses the challenges of embedding the account management role in the firm as a role of the professional or a separate function. The aim of this thesis is to conceptualise a value framework for account management. Based on the principles of grounded theory, the method comprises 29 interviews with professionals, account managers and clients. Embracing an emergent, iterative process, the lenses used to reflect on these interviews include service dominant logic, relationships, the nature of professions and professionals along with client value and notions of organisational change. The emergent perceived value framework comprises five themes. Apart from the theme ¿perceived value of account management¿, the other themes can be conceptualised at three levels: ¿ external environment; ¿ firm¿s organisation and the professional-client relationships; ¿ and account management. Furthermore, the results indicate that professional service firms have difficulty in structuring and formalising account management implying a considerable organisational culture change management agenda. The role for account management varies between an integrated account management role performed by the professional in strategic services and by full-time dedicated account managers in more commoditised services and competitive environments. Well-embedded account management provides competitive advantage and differentiates the professional service firm.
    • Understanding Gender in an Australian Trade Union. An Analysis Using Joan Ackers Theory of Gendered Organizations

      German, Hayley; Bates, Judy (University of BradfordFaculty of Management, Law & Social Sciences, 2018)
    • Understanding international efforts to address the humanitarian impacts of cluster munitions, 2003-08.

      Rogers, Paul F.; Borrie, John P. (University of BradfordSchool of Social and International Studies, 2013-12-18)
      This thesis examines the evolution of international humanitarian concern culminating in adoption of a Convention on Cluster Munitions (CCM) banning these weapons in May 2008. It is based on systematic analysis of official documents, extensive interviews, participant-observation, and several bodies of international relations (IR) theory. Part I explains the research methodology and discusses the theoretical context for the thesis. It is argued that several core assumptions of rationalist-materialist approaches to IR theory impede understanding of the CCM¿s emergence, and thus the thesis adopts an interpretivist framework. The four chapters of Part II analyse international efforts on cluster munitions including prior, failed attempts to restrict cluster munitions, the emergence of an international campaign from 2003, ensuing activity involving states, international organisations and civil society, and the CCM¿s eventual negotiation involving more than 100 states. Part III marries this empirical account to theoretical analysis of four thesis propositions. It is concluded that non-state actor-engendered processes of evidence collection and analysis, learning and frame alignment were central to the Oslo process¿s emergence. The Oslo Declaration¿s particular humanitarian framing (to ban cluster munitions causing unacceptable harm to civilians) and the structure of the subsequent ¿define-and-ban¿ discourse permitted convergence between states over prohibiting these weapons. Nevertheless, they contain implications for other international efforts aimed at controlling means of armed violence.
    • Understanding Knowledge Sharing Within Communities of Practice. A Study of Engagement Patterns and Intervention within Community of Practice.

      Hafeez, Khalid; Alghatas , Fathalla M. (University of BradfordSchool of Management, 2010-02-23)
      Online Communities of Practices (CoPs) is emerging as a major form for knowledge sharing in this era of information revolution. Due to the advancement of technology and ease of internet access in every part of the world, people began to get more and more involved in online CoPs to share knowledge. The defining characteristic of a Community of Practice is the interaction between members in order to jointly determine and embrace goals, eventually resulting in shared practices. Crucial to the success of a Community of Practice is the engagement between community members. Without engagement, a Community of Practice can not share knowledge and achieve its negotiated goals. To that end, there is a need to examine, why do people engage in an online discussion, what role domain experts play to keep on-line discussion alive and how to develop a ''right intervention'' to maintain and stimulate participants for engagement in on-line community. This thesis studied eight Communities of Practices that are being deliberately formed to facilitate knowledge sharing in the online community and describes an exploratory study of knowledge sharing within Communities of Practices (CoPs) by investigating eight CoPs ¿Start up Nation, All nurses, Young Enterpener, Teneric, SCM Focus, Systems Dynamics, Mahjoob and Alnj3 CoPs. The CoPs under investigation shared the following characteristics: permanent life span, created by interested members (i.e. bottom-up rather than top-down management creation), have a high level of boundary crossing, have more than 700 members who come from disparate locations and organizations, have voluntary membership enrollment, high membership diversity, high topic¿s relevance to members, high degree of reliance on technology, and are moderated. Data were gathered on the eight CoPs through online observations and online questionnaire survey. Results show that in each of the case study the most common type of activity performed by members of each CoP was sharing knowledge, followed by socialsing. Regarding the types of knowledge shared, the most common one across all CoPs was practical and general knowledge. The types of practical knowledge, however, varied in each CoP. The study also discovered that storytelling extensively enhances knowledge transfer and participants¿ interpersonal communications in eight communities under investigation. What were also notable in this study were the stories discussed in a CoP remains in the archive, what are more likely to generate interest and curiosity on the topic among inactive members who ultimately facilitates knowledge transfer. In this study it is also evident that successful topics with successful conclusion (in terms that the original query was answered) will not necessary get high responses and vice versa. An analysis of selected topics in the eight case studies has shown that some successful topics have few replies and vice versa, where many topics ended with open conclusion or they were unsuccessful in terms that the original query was not answered satisfactory. Therefore, it is not necessary that successful topic will get high number of responses as there are some successful topics which have limited number of replies. Overall, it is found that, topic may play a major role in the success of online discussion. It is observed in the study that members normally use short messages rather long messages and usually discusses more than one topic within one thread. Practical implications for knowledge sharing in online communities of practice were discussed, along with some recommendations for future research.
    • Understanding Madrassah Education and Its Impacts. A Case Study of Chach (Attock) region in Pakistan

      Anand, Prathivadi B.; Mdee (nee Toner), Anna L.; Akhtar, Waheed (University of BradfordBradford Centre for International Development, 2012)
      In recent years, madrassahs and their education systems in many developing countries - and specifically in Pakistan - have attracted much attention from researchers and policymakers at the local and international level. The main focus has been on the reform of madrassahs, their political activism and, more specifically, studies which attempted to investigate their alleged links with militancy. Moreover, madrassah education has been questioned for its relevance to the contemporary needs of individuals and societies. However, despite focusing on many dimensions of madrassahs, few studies have tried to understand madrassah education within the economic, socio-religious and cultural context of Pakistan. A number of publications have reached generalised conclusions about the madrassah education system in Pakistan. Inspired by this, and by adopting qualitative research methods, this study focused on two main research questions:(a) Why do people prefer a madrassah education and what type of factors shape their preference? (b) What are the socio-economic impacts of a madrassah education on individuals and at community level? Researcher conducted a field study of more than six months in the Chach (Attock) region of Pakistan. Different students, parents, madrassah teachers and key informants were interviewed to collect required informations. The findings of the study revealed that different economic backgrounds, parental religious interests, individuals¿ personal religious interests, and social norms and cultural values shape preferences for a madrassah education. Moreover, this study also revealed that there exist various socio-economic impacts of a madrassah education on individuals and at community level. However, a madrassah education has often caused conflict in communities. The study shows that while a madrassah education creates barriers to achieving modern skills and incomes, its social benefits are valuable for those living within socio-cultural constraints in rural areas. Specifically, it enhances the social status and agency of women. The study also shows that madrassah education is an opportunity for those who otherwise would have no other option to study. This study concludes that there is a need to re-think madrassah education within the economic, social, cultural and religious context of Pakistan. This study has practical implications for practitioners, madrassahs and researchers, and it also suggests further research related to madrassah education.
    • Understanding the Effects of Processing on the Properties of Perfluoroalkoxy (PFA)

      Kelly, Adrian L.; Gough, Timothy D.; Todd, Cassandra N.Z. (University of BradfordFaculty of Engineering and Informatics, 2016)
      The effect of processing on the properties of three transfer moulding grades of perfluoroalkoxy was investigated. There is anecdotal evidence to suggest exposure to high shear rates and residence time at processing temperature detrimentally affect the polymer, however there is a lack of information published in this area. This work set out to provide a better understanding of the material behaviour under various processing conditions. A bespoke capillary rheometer was used to determine flow characteristics at various temperatures between 5-400s-1. The materials were found to be shear thinning, with the virgin grades exhibiting Newtonian behaviour at low shear rates. The viscosity of the carbon black filled PFA was found to have a higher viscosity than the virgin materials, despite it having a higher Melt Flow Rate. Spectroscopy was found to be unsuitable for investigation of polymer containing carbon black due to laser heating. However changes due to residence time at processing temperature in the virgin material could be detected using statistical analysis of Near Infrared spectra. Whether the mechanical properties of the virgin material changed following exposure to high shear rates or residence time varied on manufacturer, with Dyneon 6502TZ appearing to be more process stable than Chemours 350TJ. This information can be used to optimise the transfer moulding process, and assist in meeting the requirements of the Chemical Processing Industry for larger and more complex lined piping components.
    • Understanding the International Entrepreneurial Process of Emerging Economy Firms: Evidence from Nigerian SMEs

      Owens, Martin D.; Kalantaridis, Christos; Nuhu, Nuraddeen S.
      This study is motivated by the need to improve the understanding of international entrepreneurship (IE) in emerging economies. Thus, the researcher conducted an in-depth case study of four Nigerian firms to investigate how divergent institutional conditions influence the processes of IE from emerging economies to developed economies. The findings of the study depict how entrepreneurial activity from emerging economies to developed economies can involve many sub-activities and processes to achieve opportunity identification, development, and exploitation. This process which appears disruptive is significantly supported through resource acquisition and development. However, this process of IE is heavily shaped by the institutional conditions of the international entrepreneur’s host and home markets. The institutional environment impeded growth and entrepreneurial aspirations while simultaneously facilitating access to resources, reducing risks and providing legitimacy to the firms. These simultaneous effects of institutions constrained strategic choices of the entrepreneurs and by so doing, shaped the means and processes by which they identify and execute international opportunities. The major contributions of this thesis include the validation of New Institutional Economics (NIE) framework for the examination of IE processes and empirical evidence demonstrating how entrepreneurial activity from emerging economies to developed economies can involve many sub-activities and processes to achieve opportunity identification, development, and exploitation. Also, the study guides emerging economy managers and entrepreneurs on ways to effectively manage their liabilities of smallness and foreignness. Lastly, the study provides some policy recommendations to facilitate the development of a conducive environment for entrepreneurship and IE to flourish in Nigeria.
    • Understanding the later prehistoric field systems of the Yorkshire Dales

      Armit, Ian; Gaffney, Christopher F.; Brown, Hannah J. (University of BradfordSchool of Archaeological Sciences, Faculty of Life Sciences, 2016)
      The Yorkshire Dales National Park contains some of the UK’s most extensive and well-preserved prehistoric landscapes. Of particular interest are a number of coaxial field systems, which cover hundreds of hectares and exhibit significant time-depth, yet remain little studied and poorly understood in relation to comparable resources elsewhere in Britain and north western Europe. This research aims to address this situation, bringing together existing disparate source materials for the first time, alongside supplementary field observation, to develop a detailed record of the coaxial landscapes. Using a Geographic Information System to manage, interpret and interrogate the combined datasets, analysis focuses on form and character, and explores prehistoric use of the iconic landscape. The study seeks to enhance our knowledge and understanding of the landscapes’ place in space and time, setting them against the backdrop of systems elsewhere, and attempts to place them within the context of later prehistoric society. The research, conducted in association with the Yorkshire Dales National Park Authority, also informs the management and public understanding of the archaeological resource of the Dales via the Historic Environment Record.
    • United States Use of Force against Terrorism and the Threat of Terrorism: An Analysis of the Past Four U.S. Presidents¿ Use of Force to Combat International Terrorism.

      Rogers, Paul F.; Starr-Deelen, Donna G. (University of BradfordDepartment of Peace Studies, 2014-05-02)
      The thesis analyzes how the administrations of Ronald Reagan, George H.W. Bush, Bill Clinton, and George W. Bush used force in response to incidents of international terrorism. Key players in each administration and whether they advocated a law enforcement approach or a war paradigm approach to counterterrorism are examined. In addition, Koh¿s pattern of executive initiative, congressional acquiescence, and judicial tolerance forms a theoretical lens through which to compare and contrast administrations. An assessment of the role of Congress in making the administrations¿ counterterrorism policies confirms the vitality of this pattern, and suggests future administrations will adhere to it. During the George W. Bush administration, Koh¿s pattern of executive initiative (led by personalities like Vice President Cheney), congressional acquiescence, and judicial tolerance combined with the 9/11 tragedy and pervasive fears of another attack to create a ¿perfect storm¿ known as the ¿war on terror¿. The research also analyzes to what extent the four administrations were constrained by international legal norms on the use of force, i.e. articles 2(4) and 51 of the UN Charter. On the domestic side, the thesis analyzes the extent to which American legal norms on the use of force constrained the administrations. Although the lack of compelling constraints on the use of force is present in all four administrations, the thesis indicates that the George W. Bush administration embodied an extreme example of this trend.
    • University Knowledge Commercialisation through an Institutional Logics Perspective: The case of Oman

      Kalantaridis, Christos; Awlad-Thani, Faiza S.S.
      University Knowledge Commercialisation‘ (UKC) has come to be seen as a stimulant for developing economic performance. Regardless of the increasing body of literature in the UKC, it is revealed to be undertheorized, whilst existing theories are the result of inductive theorizing based on successful KC stories within the western context. Moreover, the literature provides modest practical directions and pay insufficient attention to the role of mechanisms, such as power, mimetic isomorphism, and intermediation, in bridging differences in institutional logics between actors. These gaps inspired the study aim, which is to explore the implication of such mechanisms in bridging differences in logics within UKC institutionally emerging context, Oman. Through a qualitative, multiple case-study approach, data was collected from four contract research projects through semi-structured interviews. The first three interviews served as a pilot study, the results of which were then used to formulate the second stage which was interviews with participants from academia, industry, and government. This approach improves the internal validity of the research, and provides a rich picture of the Omani UKC emerging institutional environment. The findings suggest that the influences of power, mimetic isomorphism, and intermediation have significantly shaped bridging, though not always positively, in logics in the Omani UKC context. The findings show that adverse influences in this process included: asymmetric power relationships, mimetic isomorphism‘s simplistic view of logics convergence and negligence of institutional fragmentation, and insufficient intermediation activities. The novelty of introducing the concept of power adds a new theoretical dimension into the UKC and ILP theories. Additionally, the novelty of using case of Oman as an empirical study added new contribution into the field. In addition, this study contributes to a better understanding of the Omani policy actions with regard to shift to an effective UKC approach.
    • Unraveling selves: A Butlerian reading of managerial subjectives during organizational change.

      Ford, Jackie M.; Harding, Nancy H.; Mischenko, Jane E. (University of BradfordSchool of Management, 2015-07-15)
      This poststructuralist research into managerial subjectivity follows ten senior managers’ experience, during significant organizational restructuring in the National Health Service. Located in the North of England the managers were interviewed three times during an eighteen-month period. An autoethnographic component is integral to the study; this recognises the researcher was a practising manager undergoing the same organizational change, whilst researching the field. Judith Butler’s theories provide the principle theoretical framework for the study. Whilst the managers narrated a fantasy of having a ‘true’ and coherent self, the research illustrated how fragile, fleeting and temporary each managerial self is and how passionately attached to their managerial subjectivity (despite how painful) they were. Emotion is presented as inextricably tied up with gender performativity and managerial subjectivity; despite best efforts the emotional ‘dirt’ of organizations cannot be ordered away; there is a constant seepage and spillage of emotion – as illustrated in the vignettes and profiled in the Butlerian deconstruction. During organizational change there was a fear of a social (organizational) death and even the most senior of managers were profoundly vulnerable. This fear and vulnerability heightened in contact with others perceived as more powerful (in critical conversations and interviews). Failure to receive the desired recognition and the risk of being organizationally unintelligible compounded this vulnerability and triggered recurrent, unpredictable patterns of loss, ek-stasis and unravelling of the managerial self. This acute vulnerability during restructuring anticipates and therefore (re) enacts a Machiavellian discourse, one that excuses unethical behaviour and relations as a ‘necessary evil’.
    • Unravelling novel molecular targets for photobiomodulation in human hair follicle towards the development of more effective light-based therapies for hair growth

      Botchkareva, Natalia V.; Mardaryev, Andrei N.; Buscone, Serena (University of BradfordFaculty of Life Sciences, 2017)
      Light and optical techniques have made a profound impact on modern medicine both in diagnostics and in therapy. Therapeutic action of light is based on photomechanical, photothermal, photochemical and photobiological interactions, depending on the wavelength, power density, exposure time and optical properties of tissue and cells. Last decade experienced a growing rise of commercial devices for management of hair growth, where all of them are based on low levels of light resulting into photobiological, non-thermal interaction of photons with cells, a process that recently has received an official term ‘photobiomodulation’. However, the design and analysis of the reported clinical studies are highly debated in a wider scientific community. The picture is further complicated by a virtual lack of proof about the exact molecular targets that mediate the physiological response of skin and hair follicles (HF) to low levels of light. The goal of this project was to investigate the expression of light-sensitive receptors in the human HF and to study the impact of UV-free blue light on hair growth ex vivo. The expression of Cryptochromes 1 and 2 (CRY1, 2), Opsin 2 and 3 (OPN2 and OPN3), but not other Opsins 1, 4 and 5 was detected in the distinct compartments of skin and anagen HF. Evaluation of the physiological role of detected light-sensitive receptors on hair growth was performed by the modulation of photoreceptors activity in HF ex vivo model. HFs treated with KL001, a stabilizer of CRY1 protein that lengthens the circadian period, delayed HF anagen-catagen transition; while silencing of CRY1 induced premature catagen development accompanied by reduced cell proliferation. Silencing of CRY1 in the HF outer root sheath (ORS) cells in vitro caused downregulation of ii genes involved in the control of proliferation; including the cyclin dependent kinase 6 (CDK6). OPN3 also had a positive effect on metabolic activity and proliferation of the ORS cells in vitro. OPN3 silencing resulted in the altered expression of genes involved in the control of proliferation and apoptosis. Investigated CRY1, OPN2 and 3 greatly absorb in the blue to green-region of the visible spectrum. This led us to investigate the effect of blue light on HF growth. Daily treatment with blue light (453 nm, 3.2 J/cm2, 16 nm full width half maximum) prolonged anagen phase in HF ex vivo that was associated with sustained proliferation. In addition, blue light (3.2 J/cm2) significantly stimulated proliferation of ORS cells in vitro. This effect was abrogated by silencing of OPN3. To summarize, CRY 1, OPN 2 and OPN 3 are expressed in the distinct compartments of the HF, including HF stem cells. Blue light (453 nm) at low radiant exposure exerts a positive effect on hair growth ex vivo, potentially via interaction with OPN3. The further research should be conducted to decipher interactions between blue light and the investigated receptors in the HFs. In addition, the beneficial effect of blue light at low radiant exposure on hair growth raises a possibility of increasing therapeutic efficacy when combined with topical chemistry used for management of hair growth.
    • Use of liquid chromatography for assay of flavonoids as key constituents and antibiotics as trace elements in propolis. Investigation into the application of a range of liquid chromatography techniques for the analysis of flavonoids and antibiotics in propolis; and extraction studies of flavonoids in propolis

      Assi, Khaled H.; Paradkar, Anant R.; Kamble, Ujjwala Kerba (University of BradfordFaculty of Life Sciences, 2016)
      Propolis is an approved food additive containing flavonoids as a major active constituent. Variability has been found in the composition of propolis in distinctive regions and it was noticed that there are limitations in the analysis of propolis. In this study, the identification of ten flavonoids and residual antibiotics in propolis was investigated by using several liquid chromatography techniques, including reversed-phase high-performance liquid chromatography (RP-HPLC), microemulsion LC (MELC) and ultra-performance LC (UPLC). The ten flavonoids that were selected for this research include rutin, myricetin, quercetin, apigenin, kaempferol, pinocembrin, CAPE, chrysin, galangin and acacetin while chlortetracycline, oxytetracycline and doxycycline were selected to examine the residual antibiotics in propolis. For the analysis of the selected flavonoids, routine RP-HPLC method was found to be the best method, while MELC technique was found more efficient for the analysis of the selected antibiotics. Solid phase extraction with HLB sorbent was utilised in the analysis of antibiotics for clean-up of propolis. In method development studies for flavonoids and antibiotics, one-factor-at-a-time (OFAT) approach was followed. The final optimised method for the analysis of flavonoids as well as the method. for the analysis of antibiotics was validated using the ICH guidelines, and various aspects, such as the linearity, selectivity, accuracy, recovery, robustness and stability parameters, were examined. Development of efficient conventional method for the extraction of flavonoids from propolis was studied extensively in the present research work using different extraction techniques such as maceration, hot extraction, ultrasound assisted extraction. Among all extraction experiments, ethanolic extraction using ultrasound extraction method was the best efficient approach. This thesis shows that, in general, the performance of O/W MELC is superior to that of conventional HPLC for the determination of residual antibiotics in propolis. UPLC was not suitable for the analysis of flavonoids and antibiotics. The conventional LC was the only technique to separate the ten flavonoids but MELC was able to separate nine of the flavonoids with faster analysis time. This work also showed that MELC uses cheaper solvents. This considerable saving in both cost and time will potentially improve efficiency within quality control.
    • Use of nanoemulsion liquid chromatography (NELC) for the analysis of inhaled drugs. Investigation into the application of oil-in-water nanoemulsion as mobile phase for determination of inhaled drugs in dosage forms and in clinical samples.

      Assi, Khaled H.; Clark, Brian J.; Althanyan, Mohammed S. (University of BradfordPostgraduate Studies in Pharmaceutical and Biomedical Analysis, Institute of Pharmaceutical Innovation., 2011-11-09)
      There has been very little research into the bioanalytical application of Microemulsion High Performance Liquid Chromatography (MELC), a recently established technique for separating an active pharmaceutical ingredient from its related substances and for determining the quantity of active drug in a dose. Also, the technique is not good at separating hydrophilic drugs of very similar chemical structures. Different phase diagrams of oil (octane or ethyl acetate), co-surfactant (butanol), surfactant (sodium dodecyl sulphate (SDS) or Brij-35) and buffer (Phosphate pH 3) were developed and several nanoemulsion mobile phases identified. Nanoemulsion mobile phase that is, prepared with SDS, octane, butanol and a phosphate buffer, failed to separate hydrophilic compounds with a very close chemical structure, such as terbutaline and salbutamol. A nanoemulsion mobile phase containing a non-ionic surfactant (Brij-35) with ethyl acetate, butanol and a phosphate buffer, was, however, successful in achieving a base line separation, and the method was validated for simultaneous determination of terbutaline and salbutamol in aqueous and urine samples. An oil-in-water (O/W) NELC method was developed and validated for the determination of formoterol in an Oxis® Turbuhaler® using pre-column fluorescence derivatisation. Although the same mobile phase was extended for separation of formoterol in urine, the formoterol peak¿s overlap with endogenous peaks meant that fluorescence detection could not determine formoterol in urine samples. Solid phase extraction, concentrating the final analyte 40 times, enabled determination of a low concentration of formoterol in urine samples by UV detection. The method was validated and an acceptable assay precision %CV <4.89 inter-day and %CV <2.33 intra-day was achieved. Then after the application of O/W nanoemulsion mobile phase for HPLC was extended for the separation of lipophilic drugs. The nanoemulsion liquid chromatography (NELC) method was optimised for the determination of salmeterol and fluticasone propionate in good validation data was achieved. This thesis shows that, in general, the performance of O/W NELC is superior to that of conventional High Performance Liquid Chromatography (HPLC) for the analysis of both hydrophilic and lipophilic drugs in inhaled dosage formulations and urine samples. It has been shown that NELC uses cheaper solvents and that analysis time is faster for aqueous and urine samples. This considerable saving in both cost and time will potentially improve efficiency within quality control.
    • The use of solubility parameters to predict the behaviour of a co-crystalline drug dispersed in a polymeric vehicle. Approaches to the prediction of the interactions of co-crystals and their components with hypromellose acetate succinate and the characterization of that interaction using crystallographic, microscopic, thermal, and vibrational analysis.

      Forbes, Robert T.; Bonner, Michael C.; Isreb, Abdullah (University of BradfordThe School of Pharmacy., 2013-04-09)
      Dispersing co-crystals in a polymeric carrier may improve their physicochemical properties such as dissolution rate and solubility. Additionally co-crystal stability may be enhanced. However, such dispersions have been little investigated to date. This study focuses on the feasibility of dispersing co-crystals in a polymeric carrier and theoretical calculations to predict their stability. Acetone/chloroform, ethanol/water, and acetonitrile were used to load and grow co-crystals in a HPMCAS film. Caffeine-malonic acid and ibuprofennicotinamide co-crystals were prepared using solvent evaporation method. The interactions between each of the co-crystals components and their mixtures with the polymer were studied. A solvent evaporation approach was used to incorporate each compound, a mixture, and co-crystals into HPMCAS films. Differential scanning calorimetry data revealed a higher affinity of the polymer to acidic compounds than their basic counterparts as noticed by the depression of the glass transition temperature (Tg). Moreover, the same drug loading produced films with different Tgs when different solvents were used. Solubility parameter values (SP) of the solvents were employed to predict that effect on the depression of polymer Tg with relative success. SP values were more successful in predicting the preferential affinity of two acidic compounds to interact with the polymer. This was confirmed using binary mixtures of naproxen, flurbiprofen, malonic acid, and ibuprofen. On the other hand, dispersing basic compounds such as caffeine or nicotinamide with malonic acid in HPMCAS film revealed the growth of co-crystals. A dissolution study showed that the average release of caffeine from films containing caffeine-malonic acid was not significantly different to that of films containing similar caffeine concentration. The stability of the caffeine-malonic acid co-crystals in HPMC-AS was prolonged to 8 weeks at 95% relative humidity and 45°C. The theory developed in this project, that an acidic drug with a SP value closer to the polymer will dominate the interaction process and prevent the majority of the other material from interacting with the polymer, may have utility in designing co-crystal systems in polymeric vehicles
    • The use of the fungus Ascochyta caulina as a biological control agent for the weed Chenopodium album. Evaluation of the bioherbicide formulation efficacy of Ascochyta caulina on different life stages of the weed plant Chenopodium album under laboratory and field conditions comparing Libyan and UK populations.

      Hale, William H.G.; Donahue, Randolph E.; Asshleb, Almabrouk A. (University of BradfordDivision of Archaeological, Geographical and Environmental Sciences, 2010-09-17)
      Chenopodium album is considered one of the most important weeds adversely affecting agricultural production due to its highly competitive influence on field crops. Chemical herbicides have increased the efficiency of farming, but recently problems of herbicideresistant weed populations and herbicide residues in soil, water, food products and effects on non-target organisms have increased, consequently, other methods of control of weeds by using specific fungi as herbicides have been suggested. The purpose of this research was to evaluate the biological control of the weed Chenopodium album by the fungus Ascochyta caulina. Some of the factors which control dormancy and germination of Chenopodium album seeds have been investigated to understand better the weed population dynamics. The results showed that seeds from two populations (UK and Libya) differ in their response to factors such as light, chilling, and burying in soil. This could have implications for effective control of the weed in different regions. Two formulations of mycoherbicides (Tween 80 and Gelatine based applications) were tested in the laboratory, and showed promise in reducing growth of the weed, especially the formula of Tween 80. There was extensive shoot fresh and dry weight reduction of inoculated Chenopodium album, as well as reduced root growth. Highest disease severity rates were observed on plants in the first three week of life. A field trial revealed similar results but less disease severity was observed, possibly because of dry weather. However, it was concluded that the fungus Ascochyta caulina is a potentially useful biological control agent but many factors still can be modified in relation to application of the mycoherbicide to increase its efficacy.
    • Using Link Layer Information to Enhance Mobile IP Handover Mechanism. An investigation in to the design, analysis and performance evaluation of the enhanced Mobile IP handover mechanism using link layer information schemes in the IP environment.

      Awan, Irfan U.; Holton, David R.W.; Alnas, Mohamed J.R. (University of BradfordDepartment of Computing, 2011-06-16)
      Mobile computing is becoming increasingly important, due to the rise in the number of portable computers and the desire to have continuous network connectivity to the Internet, irrespective of the physical location of the node. We have also seen a steady growth of the market for wireless communication devices. Such devices can only have the effect of increasing the options for making connections to the global Internet. The Internet infrastructure is built on top of a collection of protocols called the TCP/IP protocol suite. Transmission Control Protocol (TCP) and Internet Protocol (IP) are the core protocols in this suite. There are currently two standards: one to support the current IPv4 and one for the upcoming IPv6 [1]. IP requires the location of any node connected to the Internet to be uniquely identified by an assigned IP address. This raises one of the most important issues in mobility because, when a node moves to another physical location, it has to change its IP address. However, the higher-level protocols require the IP address of a node to be fixed for identifying connections. The Mobile Internet Protocol (Mobile IP) is an extension to the Internet Protocol proposed by the Internet Engineering Task Force (IETF) that addresses this issue. It enables mobile devices to stay connected to the Internet regardless of their locations, without changing their IP addresses and, therefore, an ongoing IP session will not be interrupted [2, 3, 4]. More precisely, Mobile IP is a standard protocol that builds on the Internet Protocol by making mobility transparent to applications and higher-level protocols like TCP. However, before Mobile IP can be broadly deployed, there are still several technical barriers, such as long handover periods and packet loss that have to be overcome, in addition to other technical obstacles, including handover performance, security issues and routing efficiency [7]. This study presents an investigation into developing new handover mechanisms based on link layer information in Mobile IP and fast handover in Mobile IPv6 environments. The main goal of the developed mechanisms is to improve the overall IP mobility performance by reducing packet loss, minimizing signalling overheads and reducing the handover processing time. These models include the development of a cross-layer handover scheme using link layer information and Mobile Node (MN) location information to improve the performance of the communication system by reducing transmission delay, packet loss and registration signalling overheads. Finally, the new schemes are developed, tested and validated through a set of experiments to demonstrate the relative merits and capabilities of these schemes.