Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

What determines whether a mosquito develops as a male or a female is largely unknown. This question is not just an academic curiosity. Only female mosquitoes feed on vertebrate blood and hence are capable of transmitting disease. And the variety of diseases transmitted by mosquitoes is staggering. This proposal focuses on the Anopheles mosquitoes that transmit malaria but mosquitoes also transmit a number or incurable viruses as well as a number of severe parasitic diseases of humans and animals. We will use a variety or approaches to disclose the processes that trigger the sex development of Anopheles mosquitoes. We have already identified one gene, doublesex, which switches on a different chain of events in males and females. Based on studies in other insects, and our own preliminary data, we believe that this gene is a key regulator of sexual differentiation. In this proposal we will use doublesex as an anchor to identify steps upstream and downstream of the sex differentiation pathway and thereby begin to build a picture of the sex determination process in mosquitoes. We believe that this pathway will prove to be a rich source of targets for novel mosquito intervention strategies.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

Ecological restrictions in many parts of the world are demanding the elimination of lead (Pb) from all consumer items, an important environmental context that underlies this research programme. This prohibitive trend places the ceramics industry in a precarious position as it is entirely dependent on Pb-based materials for piezoelectric applications. Piezoelectric materials are widely used in sensors, actuators and other electronic devices. The most popular materials to date are those based on the perovskite PbZrxTi1-xO3 (PZT), in use in over 90% of the piezoelectricity market. There is an urgent need to find alternatives to PZT for piezoelectric applications and in recent years, a number of materials such as Na0.5Bi0.5TiO3 (NBT) and its solid-solutions with BaTiO3 (NBT-BT) or K0.5Bi0.5TiO3 (NBT-KBT), K0.5Na0.5NbO3 (KNN) and its solid solution with LiTaO3 (KNN-LT) have been researched as possible replacements. The newer lead-free materials are united with PZT in that they exhibit a region in their phase diagrams where there appears to be a sudden change in crystal structure, typically from a rhombohedral to a tetragonal phase. This region has been termed the Morphotropic Phase Boundary (MPB) and appears to coincide with the maximum piezo-response of these materials. It is the aim of this programme to obtain a unified scientific understanding of the morphotropic phase boundary (MPB) region and its impact upon piezoelectric properties in lead-free piezoelectric materials, taking as our example the Na0.5Bi0.5TiO3 - BaTiO3 (NBT-BT) solid solution. We aim to investigate the MPB in NBT-BT from the nano-scale science to the macroscopic physical properties thus exploring this material's full potential as a functioning lead-free alternative and providing the most thorough description and understanding of an MPB in a lead-free system to date. To put this aim in context, there is currently much research world-wide addressing the full and proper description of the archetypal MPB system PZT itself, for which several key questions remain unanswered. In particular, is the MPB region truly a new monoclinic crystalline phase (as has generally accepted since the breakthrough crystallographic studies of of Noheda et al in 1999)? Or does it consist of adaptive nano-domains of tetragonal/rhombohedral symmetry? Or should it be explained through the growth and diminution of short-range order driven by correlated atomic displacements? These and further questions about the nature of the MPB must be answered URGENTLY and DIRECTLY in lead-free MPB systems themselves both for a fundamental understanding of the processes that promote high piezoelectric properties and to engineer effective new functional materials. In this materials-worldwide-network (MWN) programme, which combines leading researchers from three continents, we will apply the new and advanced experimental methodologies that have been developed to address the nano-science of the MPB to the lead-free material, NBT/BT, which is the ultimate goal of this proposal. The principal aims can be summarised as:1 To identify the nanoscale domain structure and characterize its piezoelectric response; 2 To determine the structural mechanism (transformational sequences) by which high piezoelectricity is achieved in non-Pb materials, and identify similarities and differences between MPBs in non-Pb and Pb-based systems; 3 To use this understanding to improve piezoelectric properties in NBT-BT and non-Pb systems.4 To provide an enhanced research education/experience for PhD and early-career scientists via UK/US collaborations and exchanges.Total Resource Request by each Organisation: Warwick 489,758 (EPSRC contribution 403,174): Oxford 65,183 (EPSRC contribution 52,147)Total UK resources: 554,941 (455,321 EPSRC contribution)

The overall aim of this work is the investigation of the use of shape memory alloys in rotating machinery. It has emerged from work so far that it is possible to construct a bearing support whose stiffness can be modified by the application of an electric current. This is a highly desirable property as it implies that the vibrational response can be modified, and therefore controlled. With the appropriate loops, this lead to a so-called 'Smart Machine'.Working with colleagues at University of Glasgow, two distinct systems have so far been developed to address this problem. The approach followed at Swansea has been to support the actual bearing in a pair of elastomer O-rings, whose stiffness is a function of their compressive stress. The effective stiffness of the support is controlled by varying the loading on a pair of elastomer O-rings which support the rolling element bearings. The stiffness of the O-rings is strongly influenced by the (static) loading on the elastomer and the load is applied by two sets of SMA wires as shown. Ohmic heating is used to control the temperature of the SMA wires and this is monitored by means of thermocouples. The SMA wires, shown as a single wire in figure 3, actually comprise a multiloop of wire, so arranged in order to provide sufficient compressive pre-load for the elastomer O-ring. This is a simple geometry which is employed merely to prove the concept.Experimental results to date show very promising results, with natural frequencies being shifted by more than 50% as current is applied.To take this work forward it would be highly beneficial to discuss with members of the group at Virginia Tech, many of whom have extensive experience with SMA application.The subsidiary part of this visit, to a bearing manufacturer in Calgary is in the same general are of 'Smart Machines', albeit a somewhat different application.