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This study theoretically investigates the changes in the energy spectrum of the graphene monolayer subjected to different periodic potential to allow manipulation of the energy spectrum. Floquet theory and the resonance approximation are used to analyse the energy spectrum. Thus, we reviewed the application of single laser potential; linearly polarised and circularly polarised and concluded that the gap opening in the spectrum is determined by the polarisation of the laser field. Then we apply a time periodic electric filed and found that such single potential is not enough to break the topological symmetry. We investigate the manipulation of the spectrum in 1- spatial periodic magnetic field and 2- linearly polarised laser beam with an external periodically modulated static magnetic/electric field. We investigated in particular, the creation and the destruction of the Dirac-Weyl points. We found that at certain conditions the graphene is transformed into the two-dimensional Weyl metals, where each of the two original graphene Dirac cones is split into pairs of the Weyl cones. We also show that altering the laser's beam incidence (tilting) angle may lead to appearing and disappearing of the pairs of Weyl points, the opening gap in the spectrum, and its efficient manipulation. Deformation and symmetry breaking can be achieved via different laser s frequencies and amplitudes, hence the anisotropy can be controlled.

Forced displacement is the crises of our time as it has reached an unprecedented magnitude and rate, which exceeds the capacity of the international relief system and required efforts from global citizens, institutions, governments and communities. Social psychology has an important role in this needed mass response, to provide a better understanding of how the forcibly displaced people deal with their situation and how they are affected by it. Taking into consideration the sharp gap of resources available to the international relief system, it is especially important to understand the natural mechanisms of support the affected communities have, which can be an effective tool to build more efficient interventions and to empower marginalised communities and individuals. This research project aims to explore one possible mechanism underlining social support among refugees of conflict in developing countries, and sought to answer three main questions: how refugees help each other? Does sharing an emergent identity of being a “refugee” facilitate support among them, similar to people affected by disasters? Does this shared identity-based support impact their health? After conducting a systematic literature review (Paper 1) of psychosocial support among refugees of conflict in developing countries, we identified that the main challenge was the stressors arising from the exile environment (secondary stressors) and found indications of shared identity-based support among them. To do further exploration with social identity in mind, we conducted an 8-month ethnography (Paper 2) with Syrian refugees in Jordan that revealed an emergent shared “refugee” identity which seems to stem from a sense of common fate and motivates providing help to other refugees in addition to creating new social networks in exile that facilitates support efficiently. To better understand the secondary stressors (Paper 3), we conducted a survey (N = 305) and combined it with ethnographic data to find that Syrian refugees in Jordan suffer the most from financial stressors, due to loss of income and high living expenses; environmental stressors arise from exile and are either circumstantial (e.g., services and legal requirements) or created by this environment (e.g., instability and lack of familiarity); social stressors, directly related to social relations (e.g., discrimination & exploitation). In order to explore the process of support and the exact role of shared identity, we conducted two surveys (Paper 4) among Syrian refugees in Jordan (N = 156) and Turkey (N = 234) and used path analysis to build a model, which suggested that shared social identity is an important predictor of providing support and collective efficacy, which in turn has a positive association with general health of the refugees. We found indications that such positive associations could have a buffering effect in counter to the negative effect of stressors and stress on the health of refugees. We do acknowledge the stigmatic nature of a “refugee” identity and that there are other sources of support among the refugees. Nevertheless, we suggest that shared social identity can be a valuable resource in the field of psychosocial support among refugees of conflict in developing countries, especially if incorporated in the design of community level intervention.

In this thesis we introduce a new family of finite dimensional diagram algebras over a commutative ring with identity, the decorated partial Brauer algebras. These algebras are unital, associative and have a basis consisting of decorated partial Brauer diagrams which are partial Brauer diagrams with possibly decorated edges and decorated isolated vertices. We show that this algebra is a cellular algebra by applying Theorem of Green and Paget to iterated construction . Subsequently, we give an indexing set for the simple modules. Over a field of characteristic different from 2, we determine when the decorated partial Brauer algebra is quasi-hereditary. Finally, we give a complete description of the restriction rule for the cell modules over C.

Vehicle drivers are exposed daily to harmful low-frequency vertical vibration over the frequency range of 1-20 Hz. This reduces ride comfort and safety as well as possibly causing long-term harmful effects on human health in the form of lower back pain and driver fatigue. Accordingly, intensive work has been undertaken in this field on active seat suspension systems that have superior performance over a wide frequency range compared with passive and semi-active systems. One of the main features of these systems is the control strategy that is used to generate the demand control force and whilst many control strategies have been investigated in this area; their practical implementation is challenging as they require unavailable or expensive system states. Hence, in this thesis, a novel and cost-effective strategy has been developed that uses measurable and inexpensive displacement and velocity preview information from the vehicle suspension. In addition to these practical advantages, employing a prior knowledge of the disturbance in the control strategy increases the ability of the active seat to react rapidly to disturbances and hence provides a supplementary improvement to the vibration attenuation performance. The potential application of this strategy for an active seat suspension is investigated through both simulation and experimental tests. Firstly, for simplicity, the control force is defined from this suspension preview information based upon a linear control approach, with optimum gains using an integrated simulation model of a linear quarter vehicle model (QvM) and one degree of freedom of seat suspension. These gains are obtained off-line by optimising ride comfort in terms of the vertical Seat Effective Amplitude Transmissibility (SEAT) factor using a genetic algorithm (GA) and considering the physical constraints on both the limited seat suspension travel and actuator force capacity. The experimental tests are performed using a prototype active seat suspension installed on a multi-axis simulation table (MAST), which has been developed to mimic the dynamic motion of the sprung mass of the (QvM) through the principle of hardware-in-loop (HIL) simulation. Moreover, the experimental test rig is used to estimate the characteristics of a passive seat suspension as well as the driver’s body model. The ‘preview’ control strategy is examined according to the ISO 2631-1 standard, in both the frequency and time domains, under a range of operating conditions, including different road profiles and vehicle speeds. Both simulation and experimental results reveal that, in comparison with a passive seat suspension, employing this strategy for the active seat system significantly improves ride comfort, especially over the HBSF range (4-8 Hz). Also, experimental tests demonstrate that combining both the preview information with the vehicle body and seat acceleration feedback states provides further improvement in the vibration attenuation level, achieving up to a 19.5 dB reduction over the HBSF range. The linear control approach cannot always satisfy the physical constraints over a range of operating conditions and thus, to overcome this fault, a fuzzy logic controller (FLC) is selected. Accordingly, two novel and cost-effective FLCs are designed and optimised using the Particle Swarming Optimisation (PSO) algorithm. The feedforward fuzzy logic controller (FF-FLC) uses similar preview information as in the linear control approach, while the feedforward/feedback controller (FFFB-FLC) utilises a combination of both the preview information with seat suspension deflection and velocity feedback states. Once again, the simulation and experimental results confirm the effectiveness of these strategies for attenuating the vertical vibration, especially over the HBSF range, in which the FFFB-FLC provides the best performance as well as the highest robustness level at a variety of different driver weights and vehicle speeds. The application of the preview enhanced controller for an active seat suspension in a full vehicle model has been investigated in the simulation. Accordingly, three FLCs strategies, namely, front-left suspension (FLS-FLC), front-axle (FA-FLC) and four wheels (4W-FLC), have been developed based upon which vehicle suspension or/ suspensions are used to acquire the preview information. The former involves utilising suspension displacement and velocity preview information from the vehicle suspension nearest to the driver’s seat. The FA-FLC uses similar preview information, but from the front-left and front-right suspensions, whilst the 4W-FLC controller employs similar preview information from all the vehicle suspensions. Numerical results show that the proposed controllers are very useful in attenuating the vertical acceleration at the driver’s seat compared with a passive alternative. The 4W-FLC provides the best vibration attenuation performance, independent of the vehicle speed. Finally, to reduce the implementation cost of this controller, a practical alternative has been developed that requires less measured preview information. In conclusion, using the preview information enhanced controller for an active seat suspension provides a practical and cost-effective system that improves ride comfort and reduces driver fatigue.

By presenting Kuwaiti merchants as a case study for the Arab merchants of the Gulf, this dissertation takes a fresh look at the way that the merchants of this region conducted trade as part of the first global economy. This has been useful in helping us paint a broad picture of the Gulf merchants’ communities in the pre-oil period. This serves to elucidate a model and the relationships and reasons for success or failure in this network and thereby to add to the large historiography on Indian Ocean networks. The main analytic framework of this study is based on Claude Markovit’s argument for going back to the idea of a trade network by examining it through “the circulation of men and things”. This was developed into a “circulation society” by Aslanian. The dissertation draws on original materials from Kuwait, Bahrain and London, in addition to the rozenamahs of the nakhodas (log books of the dhow captains) and interviews with some pre-oil merchants in particular, which together constitute important Asian primary sources. These sources which are pivotal to it for a framework of the circulation connections trace the concomitant development of the family firms of merchants based in India but centred on Kuwait and explores how they operated/integrated legally and illegally in the Indian Ocean economy. At the same time, it examines how the merchants expressed the economic and social institutions of pre-oil Kuwait through their long-distance trading and pearl industry and even their smuggling networks. It further explores how Kuwaiti merchants in an ocean-wide commercial society constructed relationships of economic mutualism with one another by mobilizing mudaraba (commenda) partnerships with trusted partners. Taking the broadest picture, the dissertation argues that by organizing business in creative ways in the developing world of commerce, adjusting to the rise in contemporary capitalism in the Indian Ocean and by tactically moving into global markets, the merchants could develop their increasing commercial organization whilst becoming fundamental to economic and social life in Kuwait. From the middle of the 19th century to 1946, they played a critical role in structuring and developing Kuwait’s social, economic and political life and also its stability. More importantly, by making a case study of the Kuwaiti network, the dissertation demonstrates Kuwait’s importance in the global economic structure.

Spending almost two decades of experience with one of the largest oil and gas production company in the Middle East namely “Kuwait Oil Company” as a Team Leader and Senior Counsel for the Projects and Claims Team under Legal Affairs Department has undoubtedly inspired me the notion the essence of this thesis alongside with that sort of eagerness to research in quest for the knowledge which man has always and still run after but the least nevertheless only acquired! Before I join the company in late eighties, and on my graduation I found myself in cross roads, become a lecturer and embark on the academic career and satisfy my desire for research or fight my way in the legal profession as practitioner? I walked the second route in the hope of gaining the legal experience with the thought of grapping the research route in a later stage in which I now do enjoy and live. Working with KOC, I have been involved up to teeth in different areas of law since a project documents is governed and regulated not only by contract law but commercial law, companies law, patent law, labour law, construction law and tax law are also incorporated. The dispute resolution methods are addressed as well since local litigation is the main method and international adjudication, mediation and arbitration are exceptional but used and applied in particular on LSTK, EPC, EPF and Technical Service Agreements TSAs. Negotiation rounds which were entered with international oil companies on new projects and contracts gained me skills and exceptional knowledge in applying law and practice as well as sharing expertise not only in law function but in commercial and technical angles of the project bearing in mind the diversified expertise representing all aspects of business and the approaches followed to successfully accomplish a project. In the thesis, I’ve opted to deal with the elements of dispute resolution in the construction industry on the international scale and on the local or national level choosing State of Kuwait’s legal system and enhancing the research with the practical work experience in the Kuwait Oil Company extending seven chapters for this aim. I fully hope with my humble efforts exerted in this thesis that something valuable is added to the endless and depthless ocean of legal knowledge. In addition to the introductory section, the analysis of the thesis subject will be split into and developed through seven parts. Chapter one will define the construction contract, the field of the study subject, which will be followed by the mechanism of formation of the contract subject matter in chapter two. Then, the next four chapters, the means of the most common alternative dispute resolution; namely arbitration, adjudication, expert determination and mediation will be examined respectively. Chapter seven will mainly focus on the evaluation of the Kuwaiti national oil producer (Kuwait Oil Company “KOC”) as a case study and eventually will come up with the recommendations. Then, the mission of the thesis would reach the Conclusion being the final destination of its journey.

OBJECTIVES: The aim of this in vitro study is to investigate the bond strength of recently introduced commercial denture teeth to denture base materials that are fabricated in different methods. The effect of thermocycling on shear bond strength was investigated. MATERIALS AND METHODS: From high-impact pourable acrylic HIPA (Dentsply Sirona), Ivotion Base (Ivoclar Vivadent), Lucitone Digital Print (Dentsply Sirona), and Formlabs Denture Base (Formlabs) denture base materials, plate specimens were fabricated (15 mm × 15 mm × 2 mm). These base materials were bonded to Portrait IPN (Dentsply Sirona), Ivotion Dent (Ivoclar Vivadent), Lucitone Digital Value (Dentsply Sirona), and Formlabs Denture Tooth (Formlabs) tooth rods (3.5 mm × 6 mm) according to manufacturer instructions, respectively. For each material combination, 24 specimens were prepared and divided into 2 groups including control and aged. Bond strength was determined using shear bond test. Data were analyzed using two-way ANOVA followed by Tukey’s HSD test and Student’s t test (α=0.05). RESULTS: Lucitone Digital Print (Dentsply Sirona) bonded to Lucitone Digital Value (Dentsply Sirona) and Ivotion Base (Ivoclar Vivadent) bonded to Ivotion Dent (Ivoclar Vivadent) exhibited significantly higher bond strength to high-impact pourable acrylic HIPA (Dentsply Sirona) bonded to Portrait IPN (Dentsply Sirona) and Formlabs Denture Base (Formlabs) bonded to Formlabs Denture Tooth (Formlabs) (p < 0.0001). Each paired Student’s t-test showed that thermocycling treatment decreased the shear bond strength of the Formlabs materials significantly (p < 0.0001). CONCLUSION: The application of monomer and conditioning agents improved bond strength between denture base and denture tooth material regardless of the fabrication method. Thermocycling had an adverse effect on bond strength for all materials.

Industrial flaring can have negative impacts on regional air quality and recent studies have shown that flares are often operated at low combustion efficiency, which exacerbates these air quality impacts. This thesis examines industrial flaring with the objectives of (1) assessing the air quality impacts of flares operating at a variety of conditions, (2) examining the extent to which improvements in flare operations could reduce emissions, (3) identifying opportunities for recycling flared gases in fuel gas networks, and (4) identifying opportunities for reducing the generation of flared gases, using the improved control of catalytic cracking operations as a case study. The work presented in this thesis demonstrates that flares operating at low combustion efficiency can increase localized ambient ozone concentrations by more than 15 ppb under some conditions. The impact of flares on air quality depends most strongly on combustion efficiency, the flow rates to the flares and the chemical composition (photochemical reactivity) of the emissions. Products of incomplete combustion and nitrogen oxides emissions from flaring generally had a smaller impact on air quality than unburned flare gases. The combustion efficiency at which a flare can operate can be constrained by the flare’s design. In a case study of an air-assisted flare, it was demonstrated that choices in blower configurations could lead to emissions that were orders of magnitude greater or less than those predicted using an assumed combustion efficiency of 98%. Designing flares with air-assist rates that can be finely tuned can significantly reduce emissions. Similarly, flaring can be reduced by integrating sources of waste gases into fuel gas networks. Analyses for a petroleum refinery indicated that this integration can often be accomplished with little net cost by expanding boiler capacities. Finally, flared gases can be reduced at their source. A case study of a fluid catalytic cracking indicated that using better temperature control could significantly minimize flared gases.

Industrial flaring can result in atmospheric emissions that have significant impact on regional air quality. This study investigates the impact on one-hour average ozone concentrations due to industrial flaring, using the region around Houston, Texas as a case study. Specifically, this study examined the impact on ozone formation of different flare destruction efficiencies. There are some concerns about whether flare destruction efficiency is reduced from design conditions (98 to 99% destruction) at low flare flow rates. Some studies have reported very low flares destruction efficiencies under low flow, so it is possible that ozone precursor emissions may be underestimated by an order of magnitude or more at low flow conditions. In this thesis, 100 different destruction efficiency scenarios have been constructed where destruction efficiency depends on the ratio of flare flow rate to the maximum flow rate (turndown ratio). The scenarios differ in the assumed destruction efficiency at near zero flow and the turndown ratio at which destruction efficiency returns to the design value. These destruction scenarios are applied to hourly mass flow data for twenty-five flares in Houston, Texas. The scenarios have very different impacts on air quality. The air quality implications of these results for possible modifications to flare operation are explored.