The Molecular and behavioural ecology of click beetles (Coleoptera: Elateridae) in agricultural land

The larvae (wireworms) of some click beetle genera inhabit the soil in agricultural land and are crop pests. In the UK, a pest complex of Agriotes species, A. obscurus, A. sputator and A. lineatus, has been identified as the cause of the majority of damage. However, studies on their ecology are lacking, despite knowledge of this being important for the development of sustainable risk assessment and pest management strategies, in part due to the morphologically cryptic nature of wireworms. The ecology of economically important click beetle species was investigated, focusing on UK Agriotes species. The relationship between sex pheromone trapped male Agriotes adults and wireworms, identified using a molecular tool (T‐RFLP), was influenced by sampling method, and some environmental variables significantly correlated with species distributions. Scale of sampling influenced the observed distribution of wireworms and other soil insect larvae. Other wireworm species were trapped together with Agriotes species, but mitochondrial 16S rRNA sequences could not be matched to those of other UK species. Sequences from Canadian wireworm samples revealed possible cryptic species. Differences in adult movement rates were found in laboratory tests (A. lineatus > A. obscurus > A. sputator). Molecular markers (AFLPs) were developed to assess dispersal in adult male Agriotes but further protocol optimisation is required. The results show the importance of identifying wireworms to species for assessing adult and wireworm distributions, since the Agriotes pest complex may not be present or as 3 widespread as previously assumed. Sex pheromone trapping of adults may not be appropriate for risk assessment as the relationship between aboveground adult and belowground wireworm species distribution is not straightforward. The differences observed in Agriotes species’ ecology have implications for the implementation of pest management strategies. The techniques used here can be applied in future studies to provide information on other economically important click beetle species worldwide

Numerical study of floating wind turbines: hydro- and aero-mechanics

Floating wind technology has the potential to produce low-carbon electricity on a large scale: it allows the expansion of o shore wind harvesting to deep water, indicatively from 50-60 to a few hundred metres depth, where most of the worldwide technical resource is found. New design specifi cations are being developed for floating wind in order to meet diverse criteria such as conversion effi ciency, maintainability, buoyancy stability, and structural reliability. The last is the focus of this work. The mechanics of floating wind turbines in wind and waves are investigated with an array of numerical means. They demand the simulation of multiple processes such as aerodynamics, hydrodynamics, rotor and structural dynamics; understanding their interaction is essential for engineering design, verifi cation, and concept evaluation. The project is organised in three main parts, presented below. Aero-hydro-mechanical simulation, characterising the rigid-body motions of a floating wind turbine. An investigation of multi-physical couplings is carried out, mainly through EDF R&D's time-domain simulator CALHYPSO. Wave forces are represented with the potential- ow panel method and the Morison equation. Aerodynamic forces are represented by a thrust model or with the blade element momentum theory. Main fi ndings: Exposure of fi nite-angle coupling for semi-submersible turbines with focus on heave plate excursion; characterisation of the aerodynamic damping of pitch motion provided by an operating vertical-axis turbine. Dynamic mooring simulation, focussed on highly compliant mooring systems, where the fluid-structure interaction and mechanical inertial forces can govern line tension. EDF R&D's general-purpose, finite-element solver Code Aster is confi gured for this use exploiting its nonlinear large-displacement and contact mechanics functionalities. Main findings: Demonstration of a Code Aster-based work ow for the analysis of catenary mooring systems; explanation of the dynamic mooring eff ects previously observed in the DeepCwind basin test campaign. Aeroelastic analysis of vertical-axis rotors, aimed at verifying novel large-scale floating wind turbine concepts in operation, when aeroelastic-rotordynamic instabilities may occur. The finite-element modal approach is used to qualify rotor vibrations and to estimate the associated damping, based on the spinning beam formulation and a linearised aerodynamic operator. Main fi ndings: Characterisation of the vibration modes of two novel vertical-axis rotor concepts using the Campbell diagram; estimation of the related aerodynamic damping, providing information on the aeroelastic stability of these designs

MS FT-2-2 7 Orthogonal polynomials and quadrature: Theory, computation, and applications

Quadrature rules find many applications in science and engineering. Their analysis is a classical area of applied mathematics and continues to attract considerable attention. This seminar brings together speakers with expertise in a large variety of quadrature rules. It is the aim of the seminar to provide an overview of recent developments in the analysis of quadrature rules. The computation of error estimates and novel applications also are described

Generalized averaged Gaussian quadrature and applications

A simple numerical method for constructing the optimal generalized averaged Gaussian quadrature formulas will be presented. These formulas exist in many cases in which real positive GaussKronrod formulas do not exist, and can be used as an adequate alternative in order to estimate the error of a Gaussian rule. We also investigate the conditions under which the optimal averaged Gaussian quadrature formulas and their truncated variants are internal

On an economic Arnoldi method for BML-matrices

Matrices whose adjoint is a low rank perturbation of a rational function of the matrix naturally arise when trying to extend the well known Faber-Manteuffel theorem [8,9], which provides necessary and sufficient conditions for the existence of a short Arnoldi recurrence. We show that an orthonormal Krylov basis for this class of matrices can be generated by a short recurrence relation based on GMRES residual vectors. These residual vectors are computed by means of an updating formula. Furthermore, the underlying Hessenberg matrix has an accompanying low rank structure, which we will investigate closely.status: publishe