Enhancing nucleation density and adhesion of polycrystalline diamond films deposited by HFCVD using surface treaments on Co cemented tungsten carbide

The deposition of diamond films by chemical vapour deposition onto tungsten carbide is an attractive proposition since it can lead to improvements in the life and performance of cutting tools. However, deposition of diamond onto cemented tungsten carbide (WC-Co) dental burs and inserts are problematic due to the cobalt binder in the WC that provides additional toughness to the tool but it causes poor adhesion and low nucleation density. A number of surface treatments can be used to overcome these problems including chemical etching, ion implanting, interlayer coating and bias treatment. Negative biasing of the substrate is attractive because it can be controlled precisely; it is carried out in-situ, gives good homogeneity and results in improved adhesion. On flat substrates, such as copper and silicon, biasing has been shown to give better adhesion, improved crystallinity and smooth surface. In this study, we have used a modified hot filament chemical vapour deposition (HFCVD) system to coat complex shaped tools such as dental burs with polycrystalline diamond films, which have good adhesion and crystallinity. By applying a negative bias to the substrate, we show that the nucleation density, adhesion and surface properties can be improved. The effects of various process parameters such as bias time, emission current, bias voltage and the filament arrangement on the film properties are reported. For machining applications CVD diamond coatings must be hard, wear resistance and having a good quality film

An investigation into the perspectives of providers and learners on MOOC accessibility

An effective open eLearning environment should consider the target learner’s abilities, learning goals, where learning takes place, and which specific device(s) the learner uses. MOOC platforms struggle to take these factors into account and typically are not accessible, inhibiting access to environments that are intended to be open to all. A series of research initiatives are described that are intended to benefit MOOC providers in achieving greater accessibility and disabled learners to improve their lifelong learning and re-skilling. In this paper, we first outline the rationale, the research questions, and the methodology. The research approach includes interviews, online surveys and a MOOC accessibility audit; we also include factors such the risk management of the research programme and ethical considerations when conducting research with vulnerable learners. Preliminary results are presented from interviews with providers and experts and from analysis of surveys of learners. Finally, we outline the future research opportunities. This paper is framed within the context of the Doctoral Consortium organised at the TEEM'17 conference

mGovernment Services and Adoption: Current Research and Future Direction

Part 5: Research in ProgressInternational audienceWith the unprecedented growth of mobile technologies, governments of both developed and developing countries have started adopting mobile services in the form of m-government. While the vendors and practitioners are heavily engaged in this transformation, the scholarly world is lagging to keep pace with the progress and to provide clear theoretical guidance for successful adoption. This paper takes a stock of scholarly publications on m-government adoption since the year 2000 and reports findings and future directions based on meta-analysis of secondary data. The articles were classified into research themes, delivery mode, theory and methods. The paper identifies the dearth of scholarly work and calls for more in-depth work to make important contribution in this area

Integral equation method for the electromagnetic wave propagation in stratified anisotropic dielectric-magnetic materials

We investigate the propagation of electromagnetic waves in stratified anisotropic dielectric-magnetic materials using the integral equation method (IEM). Based on the superposition principle, we use Hertz vector formulations of radiated fields to study the interaction of wave with matter. We derive in a new way the dispersion relation, Snell's law and reflection/transmission coefficients by self-consistent analyses. Moreover, we find two new forms of the generalized extinction theorem. Applying the IEM, we investigate the wave propagation through a slab and disclose the underlying physics which are further verified by numerical simulations. The results lead to a unified framework of the IEM for the propagation of wave incident either from a medium or vacuum in stratified dielectric-magnetic materials.Comment: 14pages, 3figure

Multivariate morphometric analysis of Apis cerana of southern mainland Asia

Multivariate morphometric analyses were performed on a series of worker honeybees, Apis cerana, representing 557 colonies from all of southern mainland Asia extending from Afghanistan to Vietnam south of the Himalayas. Scores from the principal components analysis revealed five statistically separable but not entirely distinct morphoclusters of bees: (1) the Hindu Kush, Kashmir, N. Myanmar, N. Vietnam and S. China; (2) Himachal Pradesh region of N. India; (3) N. India, Nepal; (4) central and S. Myanmar and Vietnam, Cambodia, Thailand, S. China and peninsular Malaysia; (5) central and S. India. The major morphoclusters are distributed coherently with the different climatic zones of the region. While populations are definable, nomenclatural adjustments remain for the future

Statistical analysis of reinforced concrete bridges in Estonia

This paper introduces a possible way to use a multivariate methodology, called principal component analysis, to reduce the dimensionality of condition state database of bridge elements, collected during visual inspections. Attention is paid to the condition assessment of bridges in Estonian national roads and collected data, which plays an important role in the selection of correct statistical technique and obtaining reliable results. Additionally, detailed overview of typical road bridges and examples of collected information is provided. Statistical analysis is carried out by most natural reinforced concrete bridges in Estonia and comparison is made among different typologies. The introduced multivariate technique algorithms are presented and collated in two different formulations, with contrast on unevenness in variables and taking into account the missing data. Principal components and weighing factors, which are calculated for bridges with different typology, also have differences in results and element groups where variation is retainedTU1406 – Quality Specifications for Roadway Bridges, standardiza- tion at a European level (BridgeSpec), a COST Action sup- ported by EU Framework Programme Horizon 2020info:eu-repo/semantics/publishedVersio

The short-term effect of swimming training load on shoulder rotational range of motion, shoulder joint position sense and pectoralis minor length

Background: Shoulder pain or injury is the most common issue facing elite competitive swimmers and the most frequent reason for missed or modified training. Literature suggests that highly repetitive upper limb loading leads to inappropriate adaptations within the shoulder complex. The most likely maladaptations to occur are variations in shoulder rotational range of motion, reduction in joint position sense and shortened pectoralis minor length. This has yet to have been confirmed in experimental studies. The aim of this study was to investigate the short-term effects of swimming training load upon internal and external rotation range of motion, joint position sense and pectoralis minor length. Method: Sixteen elite swimmers training in the British Swimming World Class programme participated. Measures of internal and external range of motion, joint position sense error score and pectoralis minor length were taken before and after a typical 2h swimming session. Results: Following swimming training shoulder external rotation range of motion and pectoralis minor length reduced significantly (-3.4°,p=<0.001 and -0.7cm, p=<0.001, respectively), joint position sense error increased significantly (+2.0° error angle, p=<0.001). Internal rotation range of motion demonstrated no significant change (-0.6, p=0.53). Discussion: This study determined that elite level swimming training results in short-term maladaptive changes in shoulder performance that could potentially predispose them to injury