81 research outputs found
Approach channels: Risk- and simulation-based design
No full textThe aim of this study is to develop new interpretation methods and overall risk assessment models for navigation aspects in association with waterway design. The methods, which are based on the results achieved from ship maneuvering simulation and numerical models, address two ship accident scenarios (i.e. grounding or collision with fixed objects) in terms of the occurrence probability of such accidents. The final results derived from risk assessment are straightforwardly used in the optimal design of waterway dimensions. Several important procedures pertaining to the application of design tools and techniques for such purposes have also been discussed.Civil Engineering and Geoscience
Towards a Global Market-Based Measure for the Aviation Industry
No full textThe aviation industry is vital for economic growth, world trade, and is a major employer. Nearly $2.4 trillion in global GDP, 35% of world trade by value and 58.1 million jobs are supported by the industry. However, with these benefits comes an impact on the environment. In 2013, aviation produced 705 million tonnes of carbon dioxide, approximately 2% of anthropogenic CO2-emissions. With air traffic projected to grow by 4-5% per annum in the coming decades, this raises the question of how sustainable growth can be achieved in the aviation sector and the need for regulatory measures. In 2013 the International Civil Aviation Organization (ICAO) adopted a Resolution in which it was decided to develop a global market-based measure (MBM). From 2020 onwards this measure - a global levy, global emissions trading, or global mandatory offsetting - would regulate carbon dioxide emissions from international aviation. However whether the measure will in fact be implemented depends for a large share on ICAO’s next General Assembly in 2016, where the 191 Member States will vote on adopting the measure. Their decision will greatly depend upon whether the global market-based measure matches their interests and agenda. Therefore the design of the global MBM is crucial in ensuring adoption and implementation. In order to reach political consensus by 2016, this thesis has focused on how a robust global market-based measure can be designed by showing the design process to arrive at the robust global market-based measure, and applying this design process. The following four principles of robust design were defined: (i) legal feasibility, (ii) political viability, (iii) purposefulness, and (iv) sturdiness.SEPAMSection E&ITechnology, Policy and Managemen
Receptor-binding studies of the DBL gamma domain of Plasmodium falciparum erythrocyte membrane protein 1 from a placental isolate
No full textWe have previously identified a number of DBL gamma domains in Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) transcripts obtained from placental parasite isolates, showing that they bind specifically to chondroitin sulfate A (CSA) (Khattab A, Kun J, Deloron P, Kremsner PG, Klinkert MQ. Variants of Plasmodium falciparum erythrocyte membrane protein I expressed by different placental parasites are closely related and adhere to chondroitin sulfate A. J Infect Dis 2001;183:1165-9). Here we give a more detailed physico-chemical and binding characterisation of the soluble, recombinant DBL gamma domain derived from one of these isolates. Results from circular dichroism and limited proteolysis experiments are consistent with the recombinant domain being expressed with the native fold. Specific binding of DBL gamma to placental cryosections was demonstrated by labeling with antibodies raised against the recombinant domain; binding was diminished after treatment of the cryosections with chondroitinase or by blocking with anti-CSA antibody, showing that CSA mediates the interaction. Binding of the DBL gamma domain to purified placental chondroitin sulfate proteoglycan (CSPG) was also studied using surface plasmon resonance techniques, with DBL gamma as analyte and CSPG immobilised on the sensor chip; these quantitative measurements gave an affinity constant in the mu-molar range under the conditions used. The native conformation of the DBL gamma domain is essential for CSPG recognition since binding to the sensor chip is abolished when the protein is irreversibly reduced. As with the placental cryosections, association was significantly reduced after treating the immobilised CSPG with chondroitinase. Together, these results demonstrate specific interaction between the DBL gamma domain and the placental receptor
Self-healing of thermoplastic polymer by living polymerization
No full textAutonomic self-healing thermosetting polymers or elastomers have been substantially studied, in which polymerization of the healing agents released from pre-embedded capsules serves as the key issue. As for thermoplastics, another major class of polymeric materials, however, researches on their self-healing approaches are less reported. Here in this work we show the feasibility of a healing chemistry based on living polymerization (that excludes the possibility of chain transfer and termination) for thermoplastics. Monomer-loaded microcapsules are dispersed in a living polymer matrix that contains living chain ends. When the fluidic monomer is released upon cracking, it is easily polymerized at room temperature wherever it meets the matrix. Then, the newly formed macromolecules, which are covalently attached to the interface, fill the interstitial space of cracks and fuse with the matrix into one, offering satisfied healing efficiency. No catalyst is required for resuming chain growth in the system. The repair processes are carried out without the necessity for manual intervention. Details of the microcapsules preparation, matrix synthesis and types of controlled radical polymerization (atom transfer radical polymerization (ATRP), and reversible addition\u96fragmentation chain transfer (RAFT)) are discussed. It is hoped that the results would serve as solid basis for the development of self-healing thermoplastic polymers
Rapid Situation Analysis: a hybrid, multi-methods, qualitative, participatory approach to researching tourism development phenomena
No full textThis study develops a hybrid, bottom-up approach to field research, namely Rapid
Situation Analysis, and implements it in Ghana. It draws on elements from two existing
participatory methodological approaches: Rapid Rural Appraisal and Participatory
RuralAppraisal. The approachwas developed to suit the particular needs of investigating
corporate social responsibility practices, sustainable development and poverty reduction
through tourism, a fragmented sector which tends to be ambiguous and unstructured and
lack cohesion (unlike, for example, agriculture or primary health care, both of which
are familiar territory for Rapid Rural Appraisal and Participatory Rural Appraisal). The
Rapid Situation Analysis bottom-up approach to data gathering was underpinned by
supporting methods, including participant and direct observation, in-depth interviews,
stakeholder focus groups and informal conversations. Moreover, the multiple methods
were further enriched by the collection of visual data in the form of moving and still
images. These research findings were fed back to the communities at the centre of the
research
Correction:Ballistic superconductivity in semiconductor nanowires (Nature Communications, (2017), 8, 1, (16025), 10.1038/ncomms16025)
No full textCorrection to: Nature Communicationshttps://doi.org/10.1038/ncomms16025, published online 06 July 2017 The original version of this Article included the authors Kun Zuo and Vincent Mourik who wish to be removed from authorship. Consequently, the author affiliations for these authors have been removed from the ‘Authors and Affiliations’ section. The original version of the ‘Contributions’ statement, which read “H.Z. and Ö.G. fabricated the devices, performed the measurements and analysed the data. S.C.-B. performed the TEM analysis. M.P.N. and M.W. performed the numerical simulations. K.Z., V.M., F.K.d.V., J.v.V., M.W.A.d.M., J.D.S.B., D.J.v.W., M.Q.-P., M.C.C. and S.G. contributed to the experiments. D.C., S.P. and E.P.A.M.B. grew the InSb nanowires. S.K. prepared the lamellae for the TEM analysis. K.W. and T.T. synthesized the h-BN crystals. L.P.K. supervised the project. All authors contributed to the writing of the manuscript”, has been amended to read “H.Z. and Ö.G. fabricated the devices, performed the measurements and analysed the data. S.C.-B. performed the TEM analysis. M.P.N. and M.W. performed the numerical simulations. F.K.d.V., J.v.V., M.W.A.d.M., J.D.S.B., D.J.v.W., M.Q.-P., M.C.C. and S.G. contributed to the experiments. D.C., S.P. and E.P.A.M.B. grew the InSb nanowires. S.K. prepared the lamellae for the TEM analysis. K.W. and T.T. synthesized the h-BN crystals. L.P.K. supervised the project. All authors contributed to the writing of the manuscript”. This has been corrected in both the PDF and HTML versions of the article.</p
Correction for Khan et al., Global selective sweep of a highly inbred genome of the cattle parasiteNeospora caninum
No full textThe authors note three author names appeared incorrectly. The author name Sarah M. Latham should instead appear as Sophia M. Latham, the author name Elizabeth A. Innes should instead appear as Elisabeth A. Innes, and the author name Johnathan M. Wastling should instead appear as Jonathan M. Wastling. The corrected author line appears below. The online version has been corrected. The authors also note that the author contributions footnote appeared incorrectly. Sophia M. Latham should be credited with designing research, performing research, and contributing new reagents/analytic tools. The corrected author contributions footnote appears below. Asis Khan, Ayako Wendy Fujita, Nadine Randle, Javier Regidor-Cerrillo, Jahangheer S. Shaik, Kui Shen, Andrew J. Oler, Mariam Quinones, Sophia M. Latham, Bartholomew D. Akanmori, Sarah Cleaveland, Elisabeth A. Innes, Una Ryan, Jan Slapeta, Gereon Schares, Luis M. Ortega-Mora, Jitender P. Dubey, Jonathan M. Wastling, and Michael E. Grigg Author contributions: A.W.F., S.M.L., J.P.D., J.M.W., and M.E.G. designed research; A.K., A.W.F., N.R., and S.M.L. performed research; A.K., J.R.-C., J.S.S., K.S., A.J.O., M.Q., S.M.L., B.D.A., S.C., E.A.I., U.R., J.S., G.S., L.M.O.-M., J.P.D., J.M.W., and M.E.G. contributed new reagents/analytic tools; A.K., A.W.F., N.R., and M.E.G. analyzed data; and A.K., J.P.D., J.M.W., and M.E.G. wrote the paper
Intrinsic self-healing of polymer solid while keeping integrity and load-bearing capability
No full textGenerally, intrinsic self-healing polymers based on reversible covalent bonds scission and reconnection would lose their load bearing capability as a result of molecular cleavage during healing process. This shortcoming also results in creep deformation of the products. To solve the problem, we introduce a novel healing mechanism by using dynamically reversible C-ON bonds. Upon heating to a certain homolysis temperature, C-ON bonds in alkoxyamines moieties frequently cleave but immediately recombine. When alkoxyamines are incorporated into polymer chains, C-ON covalent bonds fission and recombination synchronously take place with very high frequency, and the equilibrium tends to the combination side. Cracked parts can thus be restored through chemical exchange reaction of alkoxyamine moieties. More importantly, because a large amount of C-ON bonds remain connection, the possible material deformation in the course of crack remending could be avoided. Here, crosslinked polystyrenes and epoxy with alkoxyamine moieties are synthesized as model polymers to prove feasibility of the above considerations. It is shown that the polymers can repeatedly self-heal cracks without deformation induced by chain scission, and provides the polymer with mechanical stability at elevated temperature as well. Moreover, the healing can be conducted within a wide temperature range when different alkoxyamines moieties are used. Molecular structures of alkoxyamines moieties, as well as thermodynamic behavior of C-ON bonds scission and recombination, etc., are studied in detail to optimize selfhealing behavior of the polymers. Full reversibility can be acquired when only one type of C-ON bond is included in the polymers. Accordingly, synthesis routes, molecular structures, thermally reversible characteristics, self-healing performance and self-healing mechanism, thermal stability and thermal-mechanical properties, etc, have been studied in detail
Effect of viscoelasiticity on the far-dissipation range of homogeneous isotropic turbulence
No full textThe comparison of the results of direct numerical simulations of isotropic turbulence of Newtonian and viscoelastic fluid, based on the FENE-P model, provide evidence that viscoelasticity modifies qualitatively the behavior of the smallest scales: we observe a k−6 law in the far dissipation range of the energy spectrum and we show that it is a robust feature, roughly independent of the large-scale dynamics. It is further shown that the drag-reduction in such flows, as measured by the difference in energy dissipation between Newtonian and viscoelastic flow, strongly depends on the initial conditions
Mobile phone use across cultures: A comparison between the UK and the Sudan
Get PDFThis thesis was submitted for the degree of Doctor of Philosophy and was awarded by Brunel University.Over the last decade the use of mobile phones has increased dramatically everywhere
by people from different cultural backgrounds. However, while such technological
adoption move on at an ever increasing pace all over the world, the key problem for
designers and developers of mobile phones is how to develop mobile phone services
that effectively support the dynamic and flexible communication needs of such
diverse groups of users.
To counter this problem, this thesis focused on establishing how people from different
cultural backgrounds use mobile phones to achieve their communicative, social and
informational goals. Questionnaires and interviews were undertaken and analysed to
achieve this. The findings from the analysis led to the development of two prototypes
missed call services; the icon-based missed call service (IBMCS) and the personalised
icon-based missed call service.
Several key findings emerged from this research. For example, mobile phone users in
the Sudan and the UK differed in the way they used their mobile phones especially in
the public places. British participants were more comfortable using their mobile
phones in public sphere. British and Sudanese stated that they would like to use an
IBMCS to support their communication needs. However, Sudanese users were more
keen than the British participants on personalising the developed missed call service
to aid the management of their communication needs and to better coordinate their
activities. The evaluation of the personalised IBMCS highlighted an important redesign
implication, such as allowing the receiver to manipulate the receipt of missed
calls in public settings
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