Micro-mechanical parameterisations for continuum modelling of granular material using the discrete element method

The present work uses the discrete element method (DEM) to describe assemblies of particulate bulk materials. Working numerical descriptions of entire processes using this scheme are infeasible because of the very large number of elements (1012 or more in a moderately sized industrial silo). However it is possible to capture much of the essential bulk mechanics through selective DEM on important regions of an assembly, thereafter using the information in continuum numerical descriptions of particulate processes. The continuum numerical model uses population balances of the various components in bulk solid mixtures. It depends on constitutive relationships for the internal transfer, creation and/or destruction of components within the mixture. In this paper we show the means of generating such relationships for two important flow phenomena – segregation whereby particles differing in some important property (often size) separate into discrete phases, and degradation, whereby particles break into sub-elements, through impact on each other or shearing. We perform DEM simulations under a range of representative conditions, extracting the important parameters for the relevant transfer, creation and/or destruction of particles in certain classes within the assembly over time. Continuum predictions of segregation and degradation using this scheme are currently being successfully validated against bulk experimental data and are beginning to be used in schemes to improve the design and operation of bulk solids process plant.

Generating OpenMP code using an interactive parallelization environment

Code parallelization using OpenMP for shared memory systems is relatively easier than using message passing for distributed memory systems. Despite this, it is still a challenge to use OpenMP to parallelize application codes in a way that yields effective scalable performance when executed on a shared memory parallel system. We describe an environment that will assist the programmer in the various tasks of code parallelization and this is achieved in a greatly reduced time frame and level of skill required. The parallelization environment includes a number of tools that address the main tasks of parallelism detection, OpenMP source code generation, debugging and optimization. These tools include a high quality, fully interprocedural dependence analysis with user interaction capabilities to facilitate the generation of efficient parallel code, an automatic relative debugging tool to identify erroneous user decisions in that interaction and also performance profiling to identify bottlenecks. Finally, experiences of parallelizing some NASA application codes are presented to illustrate some of the benefits of using the evolving environment.

Podcasting - delivering learning to the iTunes generation

The Guardian newspaper (21st October 2005) informed its readers that: "Stanford University in California is to make its course content available on iTunes...The service, Stanford on iTunes, will provide…downloads of faculty lectures, campus events, performances, book readings, music recorded by Stanford students and even podcasts of Stanford football games". The emergence of Podcasting as means of sending audio data to users has clearly excited educational technologists around the world. This paper will explore the technologies behind Podcasting and how this could be used to develop and deliver new E-Learning material. The paper refers to the work done to create Podcasts of lectures for University of Greenwich students.

The ABC for Life Programme - Teaching Basic Life Support in Schools

Background Less than 1% of the general public know how to assess or manage someone who has collapsed. It has been estimated that if 15–20% of the population were capable of performing cardiopulmonary resuscitation (CPR), mortality of out of hospital cardiac arrest could be decreased significantly. Training basic life support (BLS) skills to school children would be the most cost effective way of achieving this goal and ensuring that a large proportion of the population acquire basic life saving skills. Aims To assess retention of knowledge of basic life support 6 months after a single course of instruction in cardiopulmonary resuscitation designed specifically for school children. Setting School pupils in a rural location in one region of the United Kingdom. Methods A course of instruction in cardiopulmonary resuscitation – the ‘ABC for life’ programme – specifically designed to teach 10–12-year-old school children basic life support skills. The training session was given to school pupils in a rural location in Northern Ireland. A 22 point questionnaire was used to assess acquisition and retention of basic life support knowledge. Results Children instructed in cardiopulmonary resuscitation showed a highly significant increase in level of knowledge following the training session. While their level of knowledge decreased over a period of 6 months it remained significantly higher than that of a comparable group of children who had never been trained. Conclusion A training programme designed and taught as part of the school curriculum would have a significant impact on public health.

Anna Magdalena as Bach's Copyist

Among the wives of eighteenth-century composers, no one is perhaps more favourably and affectionately described than Bach's second wife, Anna Magdalena (1701-1760). She has been commonly pictured as her husband's trusted assistant, copying his works in handwriting which closely resembled her husband's beautiful calligraphy. No one appreciates her contributions more than today's musicologists, for her copies are usually 'neat and accurate', and are often among the most important primary sources when Bach's autographs do not survive. Occasionally, however, it is difficult to accommodate this patronising view of her role and its significance. It is well known, for instance, that her copy of Bach's Cello Suites (BWV 1007-1012) contains an unusually large number of inaccuracies and copying errors. One must ask how many of these blunders should be ascribed to her. How would a 'neat and accurate' copyist produce such an error-ridden manuscript if she had made it from a fair copy? In this paper, I shall first discuss Anna's copies of Bach's works, and see if any particular patterns or tendencies in her copying activities emerge when these are placed in this broader chronological context. In an attempt to evaluate her performance as a copyist, I shall look at typical situations in which she worked, while at the same time seeking to discover what additional values her copies may bring to our studies of Bach's life and works.

Dual-mode compact structure comprising of side-fed bifilar and quadrifilar helix antenna

A side-fed bifilar helix antenna can be integrated with a quadrifilar helix antenna in a piggy back configuration in order to achieve a dual-mode radiating structure. The overall length of the structure is 0.44 lambda at the resonant frequency (1.54 GHz) of the space mode antenna and 0.39 lambda at the resonant frequency (1.34 GHz) of the terrestrial mode antenna. The computed results are validated by experimental data.

Quantitative surface-enhanced Raman spectroscopy

The purpose of this tutorial review is to show how surface-enhanced Raman (SERS) and resonance Raman (SERRS) spectroscopy have evolved to the stage where they can be used as a quantitative analytical technique. SER(R)S has enormous potential for a range of applications where high sensitivity needs to be combined with good discrimination between molecular targets, particularly since low cost, compact spectrometers can read the high signal levels that SER(R)S typically provides. These advantages over conventional Raman measurements come at the cost of increased complexity and this review discusses the factors that need to be controlled to generate stable and reproducible SER(R)S calibrations.

Multiple model bootstrap filter for maneuvering target tracking

The extension of the bootstrap filter to the multiple model target tracking problem is considered. Bayesian bootstrap filtering is a very powerful technique since it represents samples by random samples and is therefore not restricted to linear, Gaussian systems, making it ideal for the multiple model problem where very complex densities fan be generated.

Electrical characterization of ALD Al2O3 and HfO2 films on germanium

Al2O3 and HfO2 films were deposited on germanium substrates by atomic layer deposition (ALD) and analyzed by MOS capacitor electrical characterization. In-situ plasma nitridation performed prior to ALD was found to improve the stability of the interface. For Al 2O3/GeON/Ge capacitors, a 450°C anneal in nitrogen ambient reduced hysteresis and oxide fixed charge to 90 mV and 1012 cm-2 respectively, with low leakage current density. On the contrary, degradation was observed for un-nitrided Al2O3/Ge capacitors after 300 and 400°C post-metal anneals. HfO2/GeON/Ge capacitors benefitted from a 400°C densification anneal but exhibited degradation after post-metal anneals at temperatures greater than 300°C. This degradation is attributed to the influence of Al electrodes on the HfO 2 gate stack. HfO2 is considered to be a suitable material for the gate stack and Al2O3 for the buried dielectric in a GeOI structure. ©The Electrochemical Society.

Expression of osteopontin coregulators in primary colorectal cancer and associated liver metastases

Background: A transcription regulatory complex (TRC) that includes Ets1, Ets2, PEA3 and ß-catenin/T-cell factors regulates osteopontin (OPN) that is implicated in colorectal cancer (CRC) dissemination. The consistency of OPN transcriptional control between primary CRC and metastases is unclear. This study investigates expression and prognostic significance of the OPN–TRC in primary human CRC and associated colorectal liver metastases (CRLM).

Methods: Osteopontin–TRC factors were assayed by digital microscopy in 38 primary CRCs and matched CRLM specimens and assessed against clinical prognosis.

Results: In primary CRC, OPN expression intensity correlated with that of its co-activators, PEA3 (r=0.600; P<0.01), Ets1 (r=0.552; P<0.01), Ets2 (r=0.521; P<0.01) and had prognostic significance. Osteopontin intensity in primary CRC inversely correlated with the interval between diagnosis and resection of CRLM. Overall OPN intensity was lower in CRLM than primary CRC and correlations with co-activators were weaker, for example, Ets1 (P=0.047), PEA3 (P=0.022) or nonsignificant (Ets2). The ratio of OPN expression in CRLM vs primary CRC had prognostic significance.

Conclusion: This study supports transcriptional control of OPN by known coregulators in both primary and secondary CRC. Weaker associations in CRLM suggest involvement of other unknown factors possibly from the liver microenvironment or resulting from additional genetic or epigenetic changes that drive tumour metastatic capability in OPN transcriptional control.