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.

Development of a radiographic technique for porcine head ballistic research

Introduction: The porcine model shows structural features comparable to that of humans and are routinely used within research, due to the ethical, legal, and practical use of post-mortem human samples. Methods for obtaining high quality and comparable reference data using standardised acquisition protocols are essential. Methods: The decapitated heads of three adult white sows were subjected to radiographic imaging before and after cranial trauma (9 mm, Heckler and Koch MP5). Digital radiographs were generated using a Siemens MULTIX TOP system with an Agfa digital detector, with foam blocks and sandbags as ancillary equipment. An iterative approach was adopted by the authors to generate reproducible radiographic views from two perpendicular angles. Specimens were kept at 5 °C and wrapped in polythene bags to reduce the impact of putrefaction. Results: Standardised head radiography technique was developed for superior-inferior and lateral views demonstrating porcine anatomy. Key parameters included: automatic exposure control for tube current (∼4 mAs), tube voltage of 73 kVp, 100 cm source to image receptor distance, and an anti-scatter grid. Slight variances in specimen morphology, developmental status, and soft tissue changes did not affect imaging outcomes. Conclusion: The technique and positioning proposed in this study allows for the acquisition of high quality and reproducible radiographic images for comparable ballistic research datasets. Specimen positioning and centring of the primary beam may be applied across porcine breeds, although individual radiographic parameters may differ according to equipment specifications and specimen size. Implications for practice: Development of a reproducible radiographic technique of porcine heads in forensic and veterinary research

Numerical modelling of the lobes of radio galaxies – Paper V: universal pressure profile cluster atmospheres

© 2023 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This is the final manuscript version of an article which has been published in final form at https://doi.org/10.1093/mnras/stad2933We present relativistic magnetohydrodynamic modelling of jets running into hydrostatic, spherically symmetric cluster atmospheres. For the first time in a numerical simulation, we present model cluster atmospheres based upon the universal pressure profile (UPP), incorporating a temperature profile for a ‘typical’ self-similar atmosphere described by only one parameter – M 500. We explore a comprehensive range of realistic atmospheres and jet powers and derive dynamic, energetic, and polarimetric data which provide insight into what we should expect of future high-resolution studies of AGN outflows. From the simulated synchrotron emission maps which include Doppler beaming we find sidedness distributions that agree well with observations. We replicated a number of findings from our previous work, such as higher power jets inflating larger aspect-ratio lobes, and the cluster environment impacting the distribution of energy between the lobe and shocked regions. Comparing UPP and β-profiles we find that the cluster model chosen results in a different morphology for the resultant lobes with the UPP more able to clear lobe material from the core; and that these different atmospheres influence the ratio between the various forms of energy in the fully developed lobes. This work also highlights the key role played by Kelvin–Helmholtz instabilities in the formation of realistic lobe aspect ratios. Our simulations point to the need for additional lobe-widening mechanisms at high jet powers, for example jet precession. Given that the UPP is our most representative general cluster atmosphere, these numerical simulations represent the most realistic models yet for spherically symmetric atmospheres.Peer reviewe

Thermal emission and absorption of radiation in finite inverted-opal photonic crystals

We study theoretically the optical properties of a finite inverted-opal photonic crystal. The light-matter interaction is strongly affected by the presence of the three-dimensional photonic crystal and the alterations of the light emission and absorption processes can be used to suppress or enhance the thermal emissivity and absorptivity of the dielectric structure. We investigate the influence of the absorption present in the system on the relevant band edge frequencies that control the optical response of the photonic crystal. Our study reveals that the absorption processes cause spectral broadening and shifting of the band edge optical resonances, and determine a strong reduction of the photonic band gap spectral range. Using the angular and spectral dependence of the band edge frequencies for stop bands along different directions, we argue that by matching the blackbody emission spectrum peak with a prescribed maximum of the absorption coefficient, it is possible to achieve an angle-sensitive enhancement of the thermal emission/absorption of radiation. This result opens a way to realize a frequency-sensitive and angle-sensitive photonic crystal absorbers/emitters. © 2005 The American Physical Society

An interstellar precursor mission

A mission out of the planetary system, with launch about the year 2000, could provide valuable scientific data as well as test some of the technology for a later mission to another star. Primary scientific objectives for the precursor mission concern characteristics of the heliopause, the interstellar medium, stellar distances (by parallax measurements), low energy cosmic rays, interplanetary gas distribution, and mass of the solar system. Secondary objectives include investigation of Pluto. Candidate science instruments are suggested. Individual spacecraft systems for the mission were considered, technology requirements and problem areas noted, and a number of recommendations made for technology study and advanced development. The most critical technology needs include attainment of 50-yr spacecraft lifetime and development of a long-life NEP system

The effect of electromagnetic fields and impurities on crystal growth mechanisms

The precipitation, crystallisation and aggregation processes in CaC03, BaS04-SrS04-CaC03 and CaS04-CaC03 systems have been studied. For the CaC03 system the effects of applied magnetic fields on the formation of calcium carbonate scale were the subject of a detailed investigation. The study of the BaS04-SrS04-CaC03 and CaS04-CaC03 systems was designed to determine (1) the effects of varying the ion concentrations in simulated offshore oilfield formation and sea waters and (2) the effect of the ratio of mixing the simulated waters on the rate of deposition of scale. The scale-forming properties of CaC03 are shown to be affected by applied magnetic fields. Propensity to scale data obtained by measuring the back pressure as scale builds up in a microbore tube show that the passage of calcium-containing solutions through a magnetic field prior to CaC03 precipitation delays deposition. The effects of (1) flow rate of both calcium and hydrogen carbonate ion solutions through an electromagnetic field, (2) sodium hydrogen carbonate concentration and (3) temperature on CaC03 deposition are also reported. Heat exchanger experiments show that applied magnetic field treatment causes major differences in the crystal and aggregate sizes of the precipitates and significantly reduces the quantity of scale formed. The results are interpreted in terms of the direct interaction of applied fields on charged species in fluids. The data from the present work taken with the results from previous work show that these field interactions are part of a general phenomenon. The precipitation and aggregation properties of the solids formed in the BaS04-SrS04-CaC03 and CaS04-CaC03 systems from mixed simulated formation and sea waters are reported. Precipitation tests and scale prediction model data for the BaS04-SrS04-CaC03 system provide information on the amount of each solid formed and explain changes in the propensity to scale. Data for both systems on the changes arising from increasing each significant ion concentration in the simulated offshore oilfield waters are also reported. All the changes in the propensity to scale measurements are related to solubility effects, ion-pair effects and kinetic effects

Public Health Department Accreditation in Nebraska

https://digitalcommons.unmc.edu/coph_policy_reports/1023/thumbnail.jp

A Model-Based Measure to Assess Operator Adherence to Procedures

Procedures play an important role in domains where humans interact with critical, complex systems. In such environments, the operator’s ability to correctly follow a given set of procedures can directly impact system safety. A quantitative measure of procedural adherence during training for complex system operation would be useful to assess trainee performance and evaluate a training program. This paper presents a novel model-based objective metric for quantifying procedural adherence in training. This metric is sensitive to both the number and nature of procedural deviations, and can be used with cluster analysis to classify trainee performance based on adherence. The metric was tested on an experimental data set gathered from volunteers using aircraft maintenance computer-based training (CBT). The properties of the metric are discussed, along with future possibilities

Fundamental Studies Relating to Systems Analysis of Solid Propellants

As in the previous progress reports, the contents in this report have been categorized so as to present a clear picture of their role in contributing to the problem of mechanical failure analysis. The subject of material representation by mechanical failure analysis. The subject of material representation by mechanical models is discussed in Section I, while Section II contains additions to the subject of Elastic Solutions for cylinders. The Engineering Analysis section includes an example of the strain response of an internal star grain to pressure. A damped sinusoid has been assumed for the pressure rise, and the use of stress concentration factors for a star grain is demonstrated. Section V on failure includes some preliminary test results which indicate the feasibility of the cumulative damage concept for composite (polyurethane) propellants, at least in the limited range tested. Recommendations are given which would expand this testing to show how damage accumulates under other conditions such as low temperatures, high strain-rates and with other types of propellant