Contributors: Stanier, Samuel, White, DJ
Contributors: Abadie, Christelle, Byrne, BW, Levy-Paing, S, Meyer, V
... Monopile foundations for offshore wind turbines are subjected to many cycles of loading during their lifetime. This loading consists of a range of amplitudes, applied in various sequences, of many different cycle numbers. Calculation of the accumulated rotation experienced by the monopile as a result of this cyclic loading, and whether this exceeds allowable limits, is an important part of the design process. This paper provides an overview of recent research exploring laterally loaded pile response relevant to the design of offshore wind turbine monopiles. Experimental equipment for carrying out cyclic lateral loading tests is introduced, along with considerations of scaling for model testing. Results from a series of small scale model tests covering realistic multi-amplitude testing are then presented, providing new insight into the behaviour of rigid piles subjected to cyclic loading. The results are interpreted using a linear superposition method, as typically used for structural fatigue calculations, and this shows a good fit to the experimental results.
Use of the theory of dynamical systems for transient problems: application to the switching-on problem
Contributors: Galvanetto, Ugo, Magri, Luca
... This paper addresses the problem of dynamical systems with parameters varying in time (transient systems). A method to predict their behaviour is proposed. This class of transient systems can be seen as the evolution of an ordinary steady system into another ordinary steady system, for both of which the classical theory of dynamical systems holds. The evolution from a steady system to the other is driven by a transient force, which is regarded as a map between the two steady systems. We apply our method to a system which is subjected to a transient excitation, that is neither constant nor periodic, to simulate the effect of switching-on procedures.
Contributors: Abadie, Christelle, Byrne, BW, Gaudin, C, White, D
... Most offshore wind farms around Europe are being constructed with monopile foundations. Whilst there is some knowledge transfer from oil and gas design there are also a number of key differences, which means new design guidelines are needed. This paper outlines some of the key issues confronting the offshore wind turbine foundation designer and concentrates on the effect of cyclic loading. It presents experimental results from a series of 1 g model tests, following on from the work of Leblanc et al. (2010a). The tests aim at further exploring a framework for calculating the long term accumulated rotation. The results confirm the phenomenological laws proposed by Leblanc et al. (2010a) for the accumulated rotation and the cyclic secant stiffness. The results also highlight that in addition to the relative density and load characteristics, the accumulated rotation and the secant stiffness appear to be dependent on the sand properties.
Contributors: Wright, maya, Ruggeri, Francesco, Saar, Kadi, Challa, Pavan, Benesch, Justin, Knowles, Tuomas
... In recent years, significant advancements have been made in the understanding of the population distributions and dynamic oligomeric states of the molecular chaperone αB-crystallin and its core domain variants. In this work, we provide solution-phase evidence of the polydispersity of αB- crystallin using microfluidic methods, used for separating the oligomeric species present in solution according to their different electrophoretic mobilities on-chip in a matter of seconds. We, in particular demonstrate that microfluidic high-field electrophoresis and diffusion can detect the oligomerisation of these highly dynamic molecular chaperones and characterise the dominant oligomeric species present. We thereby provide a robust microfluidic method for characterising the individual species within complex protein mixtures of biological relevance.
Research data supporting "Social information use about novel aposematic prey is not influenced by a predator’s previous experience with toxins"
Contributors: Hamalainen, Liisa, Mappes, Johanna, Rowland, Hannah M, Thorogood, Rose
... This data is from the experiment investigating social avoidance learning in wild-caught great tits, conducted at Konnevesi Research Station in Central Finland during winter 2017. Sheet 1 (“main data”) contains data from the main avoidance learning experiment, including individual attributes (sex, age, weight etc.), experimental treatments and individuals’ foraging choices in the learning trials. Sheet 2 (“preference test”) contains data from the initial preference test of the symbols that were used in the experiment, and Sheet 3 (“visibility test”) data from the initial visibility test of the same symbols.
Why should wild nature be preserved? A dialogue between biblical theology and biodiversity conservation.
Contributors: Bookless, David John Charles
... The past century has seen a rapid acceleration in global anthropogenic biodiversity loss, despite massively increased conservation effort and knowledge. Consequently, there are wide-ranging debates around whether economic and instrumental valuations of wild nature assist in its preservation, or whether they commodify entities that possess intrinsic or inherent value. This thesis seeks to bring insights from biblical theology into dialogue with conservation biology concerning the value of wild nature and the place of humanity in relation to it. Through a theological overview of four major biblical themes expressing God’s initiative towards all that exists (creation, covenant, reconciliation in Christ, and eschatological consummation), it is proposed that God’s relationship with nonhuman creation provides a useful conceptual structure in addressing contemporary conservation dilemmas. In particular, it is suggested that debates regarding anthropocentric or ecocentric, and instrumental (including economic) or intrinsic valuations of wild nature, and similarly between ‘conservation’ and ‘preservation’, may constructively be placed within a wider context regarding humanity’s place with regard to its fellow creatures. Within a Christian worldview it is proposed that this is ultimately a Theo-eco-centric context wherein all value, nonhuman and human, is contingent upon God’s purposes from creation to consummation. The conclusion of the thesis brings the theological insights of the four central chapters into dialogue again with contemporary conservation debates. Moving beyond ecocentric (nature for itself) and anthropocentric (nature for people) motivations for conserving wild nature, it proposes a concept of ‘people within nature’ that is theologically coherent but expressed in language that brings biblical theology into debate both with secular conservationists and those of other faith traditions. It recognises both humanity’s total dependence on thriving ecosystems and the particular role humans play in nature’s protection. The language of virtue ethics is posited as being particularly valuable in this regard. It is hoped that this thesis will be a useful contribution to current conservation debates surrounding how nature should be valued, and will also encourage deeper theological reflection on the place and value of nonhuman animals.
Contributors: Feng, xiaolei, Gao, Pengyue, Li, Xue, Wu, Min, Wang, Hui, Lv, Jian, Redfern, Simon, Liu, Hanyu, Ma, Yanming
... Structure searches of beryllium chalcogenides (BeS, BeSe, and BeTe) at high pressures using a swarm intelligence algorithm, in conjunction with density functional theory, reveal modulated polymorphs, unusual for such simple binary compounds. Apart from the well-known cubic (space group F-43m, zinc-blende structure) to hexagonal closed packed (space group P63/mmc, nickel-arsenide structure) structural transition, a further transition at higher pressure to an orthorhombic structure is predicted for BeS and BeSe. The orthorhombic phase is space group Cmca in BeS and Pnma before finally adopting Cmca in BeSe, each accompanied by the onset of modulation of the atomic arrangement. The amplitude of displacements associated with the modulation increases with increasing pressure and molecular dynamics simulations show the modulated structure to become stable at least to 300 GPa and 2000 K. This unusual structural modulation is not seen, however, in BeTe, which instead transforms to a C2/m phase. Links are drawn between the modulated phases of BeS and BeSe and the high-pressure modulated phases of their parent chalcogens. Our results provide key insights into understanding the modulation in binary compounds at high pressure.
Comparative analysis of gene expression in virulent and attenuated strains of infectious bronchitis virus at sub-codon resolution
Contributors: Brierley, Ian, Dinan, Adam, Keep, Sarah, Bickerton, Erica, Britton, Paul, Firth, Andrew
... Like all coronaviruses, avian infectious bronchitis virus (IBV) possesses a long, single-stranded, positive-sense RNA genome (~27 kb) and has a complex replication strategy that includes the production of a nested set of sub-genomic mRNAs (sgmRNAs). Here, we used RNA sequencing (RNASeq) and ribosome profiling (RiboSeq) to delineate gene expression in the IBV M41-CK and Beau-CK strains at sub-codon resolution. RNASeq facilitated a comparative analysis of viral RNA synthesis and revealed two novel transcription junction sites in the attenuated Beau-CK strain, one of which would generate a sgmRNA encoding a ribosomally occupied ORF (dORF) located downstream of the nucleocapsid coding region. RiboSeq permitted quantification of the translational efficiency of virus gene expression and identified, for the first time, sites of ribosomal pausing on the genome. Quantification of reads flanking the programmed ribosomal frameshifting (PRF) signal at the genomic RNA ORF1a/ORF1b junction revealed that PRF in IBV is highly efficient (33–40%). Triplet phasing of RiboSeq data allowed precise determination of reading frames and revealed the translation of two ORFs (4b and 4c on sgmRNA IR), which are widely conserved across IBV isolates. Analysis of differential gene expression in infected primary chick kidney cells indicated that the host cell response to IBV occurs primarily at the level of transcription, with global up-regulation of immune-related mRNA transcripts following infection, and comparatively modest changes in the translation efficiencies of host genes. Cellular genes and gene networks differentially expressed during virus infection were also identified, giving insights into the host cell response to IBV infection.