Engineering - what's that?

Engineering the Future (EtF) aims to develop a sustainable model of activities and interactions among researchers, policy makers and practitioners that develops pupils’ understanding of the nature of engineering, embeds experiences of engineering within the school classroom and curriculum and promotes engineering as a career.One barrier to young people entering engineering is inadequate awareness of the nature ofengineering and its diverse career paths. Many pupils in the participating schools had no awareness of engineering or very limited awareness. 65% had never considered engineering as a career choice.1st year electronic and electrial engineering students at the universities of Strathclyde and Glasgow identified family links as a key factor in encouraging them to study engineering. They also traced interest in engineering to particular school classroom experiences. Discussions with careers guidance staff revealed that careers guidance is almost entirely responsive to pupil requests: only occasionally will pupils who are good at science and mathematics be directed towards engineering.The current situation leaves almost all school pupils uninformed about the nature of engineering.The paper describes how the EtF project seeks to redress the situation by developing classroom engineering experiences, working to embed engineering formally in the curriculum and providing resources for active careers advice

A theoretical and experimental investigation into multilayered piezoelectric composite transducers

The behaviour of a number of 3-1 connectivity piezoelectric composite plate transducers is presented. The fundamental thickness mode resonance of such devices is found to be contaminated by lateral resonant activity; this is evidenced in the measured and predicted electrical impedance profile and the surface displacement data at the,fundamental thickness mode. Measurements taken on the 3-1 devices infer that they are not acting as true composites. In addition to this the finite element technique is applied to a number of stacked 3-1 and 1-3 connectivity devices to predict the mechanical Q-factor, and hence bandwidth, as a function of polymer filler properties

Angular momentum conservation for uniformly expanding flows

Angular momentum has recently been defined as a surface integral involving an axial vector and a twist 1-form, which measures the twisting around of space-time due to a rotating mass. The axial vector is chosen to be a transverse, divergence-free, coordinate vector, which is compatible with any initial choice of axis and integral curves. Then a conservation equation expresses rate of change of angular momentum along a uniformly expanding flow as a surface integral of angular momentum densities, with the same form as the standard equation for an axial Killing vector, apart from the inclusion of an effective energy tensor for gravitational radiation.Comment: 5 revtex4 pages, 3 eps figure

Fate of the first traversible wormhole: black-hole collapse or inflationary expansion

We study numerically the stability of Morris & Thorne's first traversible wormhole, shown previously by Ellis to be a solution for a massless ghost Klein-Gordon field. Our code uses a dual-null formulation for spherically symmetric space-time integration, and the numerical range covers both universes connected by the wormhole. We observe that the wormhole is unstable against Gaussian pulses in either exotic or normal massless Klein-Gordon fields. The wormhole throat suffers a bifurcation of horizons and either explodes to form an inflationary universe or collapses to a black hole, if the total input energy is respectively negative or positive. As the perturbations become small in total energy, there is evidence for critical solutions with a certain black-hole mass or Hubble constant. The collapse time is related to the initial energy with an apparently universal critical exponent. For normal matter, such as a traveller traversing the wormhole, collapse to a black hole always results. However, carefully balanced additional ghost radiation can maintain the wormhole for a limited time. The black-hole formation from a traversible wormhole confirms the recently proposed duality between them. The inflationary case provides a mechanism for inflating, to macroscopic size, a Planck-sized wormhole formed in space-time foam.Comment: 10 pages, RevTeX4, 11 figures, epsf.st

Engineering - young people want to be informed

Young people in developed nations recognise the contribution that science and technology make to society and acknowledge their importance now and in the future, yet few view their study as leading to interesting careers. Some countries are taking action to raise interest in science, technologies, engineering and mathematics and increase the number of students studying these subjects. One of the barriers to young people pursuing engineering is their limited or distorted perception of it - they associate it only with building and fixing things. Young people rarely encounter engineers, unlike other professionals, engineering has little or no advocacy in the media and there are few opportunities to experience engineering. Many of the pupils surveyed at the start of Engineering the Future, a three year EPSRC-funded project, wrote “don’t know what engineering is” and/or “would like more information”. This paper reports on work with researchers, policy makers and practitioners in Scotland to develop a sustainable model of activities and interactions that develops pupils’ understanding of the nature of engineering, embeds experiences of engineering within the school classroom and curriculum and promotes engineering as a career. After learning about engineering through the activities the pupils’ perceptions had improved. Almost all considered it important that young people know about engineering, because it is an essential part of everyday life and, in the words of one pupil - “If we know more about it, our minds wouldn’t stay closed to it. We would maybe take it up.

Improving the thermal stability of 1-3 piezoelectric composite transducers manufactured using thermally conductive polymeric fillers

With a view to improving the thermal stability of ultrasonic transducers prepared using 1-3 piezoelectric composites, the use of front face layers manufactured from thermally insulating and partially thermally conductive polymeric materials has been investigated. Experimentally, heat dissipation was investigated, in air and in water, using different transducer configurations and the advantage of including a front face layer manufactured from thermally conductive polymeric material is demonstrated. The PZFlex finite element modelling package was utilised to assess the thermal diffusivity of each polymer in the different transducer configurations and was found to compare well with experiment

Multi-layered piezoelectric composite transducers

Multilayered piezoelectric materials present themselves as a suitable technology for the development of sub 100kHz transducers. A variety of different configurations have been proposed, including stacked 2-2, 1-3 and 3-1 connectivity configurations. Historically multilayer devices designed for low frequency of operation have comprised uniform layer thickness through the height of the device. The potential for extended bandwidth through the use of non-uniform layers through the thickness dimension has been investigated. In addition commercially available stacked ceramic mechanical actuators have been investigated. A combination of theoretical and experimental assessment has been employed to evaluate each transducer technology. Selection of the passive phase for these multilayer devices is critical. Typically, these devices operate in the high power regime and as such selection of the passive polymer material is crucial - thermal stability coupled with thermal conductivity would be a virtue. To this end a number of polymer materials possessing the appropriate thermal properties have been investigated

Accurate angle-of-arrival measurement using particle swarm optimization

As one of the major methods for location positioning, angle-of-arrival (AOA) estimation is a significant technology in radar, sonar, radio astronomy, and mobile communications. AOA measurements can be exploited to locate mobile units, enhance communication efficiency and network capacity, and support location-aided routing, dynamic network management, and many location-based services. In this paper, we propose an algorithm for AOA estimation in colored noise fields and harsh application scenarios. By modeling the unknown noise covariance as a linear combination of known weighting matrices, a maximum likelihood (ML) criterion is established, and a particle swarm optimization (PSO) paradigm is designed to optimize the cost function. Simulation results demonstrate that the paired estimator PSO-ML significantly outperforms other popular techniques and produces superior AOA estimates

Research policy and practice - commitment, complexity and uncertainty: a case study of a government research council funded project, engineering the future

Evidence based policy formation, both at EU and national level, built upon close linkage of research, policy and practice is regarded by many as an optimum solution. However, while there are many examples in European education of any two of these communities collaborating in development, the realisation of meaningful inter-relationships among all three communities is complex (Ball 1997). Evidence is often contested, while policy is determined not only by explicit political philosophies but also by deeply embedded assumptions. This paper examines this complexity through the lens of a case study in one country, Scotland, which illuminates relationships among the policy, research and practitioner communities at national and local levels and the nature of their contributions to national curriculum development. The paper explores potential tensions between the development of participative ways of working and the existing structures and ways of thinking within an education system, and examines limitations on what can be effected within existing governance systems. Since 1999 the Scottish Parliament sets the legal framework for education in Scotland; within this the Scottish government has full responsibility for education policy and provision. Following the outcomes of a government initiated National Debate on the purposes and practices of school education, Scotland?s school system has for the last six years been the locus of an extensive and radical development programme in curriculum, assessment and pedagogy (Curriculum for Excellence)

Instrumented transducer for study of the bat echolocation process

Evolution has enabled the bat to echolocate with ease and efficiency, to the extent that the bats capabilities far exceed the most technologically advanced manmade systems. Such capabilities reinforce mans intrigue in the animal kingdom. In studying bats we aspire to quantify and understand their inherent skills in the hope of transferring them to engineering systems. In trying to further our understanding of the animal kingdom it is often the case that we try to replicate or mimic what the animal is doing. In terms of echolocation it is thought that a bat emits a signal and retains memory of an exact copy to be used in conjunction with the returning echo to reveal information about the target. To emulate the vocalisation and auditory system of a bat it is necessary to both accurately generate and detect sound waves