Spiral Growth Manufacturing (SGM) – A Continuous Additive Manufacturing Technology for Processing Metal Powder by Selective Laser Melting

Spiral growth manufacturing is a new innovative powder based rapid manufacturing technique. The innovation exists in the methodology in which powder layers are deposited. Unlike other pre-placed powder systems, the deposited layers move relative to the location at which they are processed. This is made possible by a rotating build drum into which powder is deposited, in spiralled layers, from a stationary hopper. With this configuration powder can be continuously deposited and levelled and simultaneously processed, eliminating delays in the build cycle. Stainless steel and cobalt-chrome powder is selectively melted using a 100W flash lamp pumped Nd:YAG laser. This paper reports on factors affecting build rate and on build strategies for creating a number of axis-symmetric thin and thick walled cylinders. Experimental results suggest that build rate for thin walled structures bonded to a substrate will ultimately be governed by tangential movements of the powder particles when frictional forces are not sufficient to accelerate the particles along a curved path, provided that enough laser power is available for melting. Even melt pool balling, which is evident when melting one layer at high speeds, diminishes in multiple layer builds due to re-melting and infilling.Mechanical Engineerin

Image Transformations and Printing of Plaster Layers in Spiral Growth Manufacturing

Spiral growth manufacturing (SGM) is a high speed rapid manufacturing technique in which objects are built up, layer by layer, by simultaneously depositing, levelling and selectively consolidating thin powder layers onto a rotating build platform. The size and position of the jetted droplets are mapped by the position and greyscale level of pixels within an 8 bit greyscale bitmap image. This paper reports on the development of software in which mathematical algorithms apply geometric transformations to images in preparation for printing onto a rotating substrate. In support of this work, dimensional accuracy measurements of printed images and methods to correct radial print density variations are reported. The accuracy of printed images were found to be within ±0.2mm of their predicted size. The experimental work is briefly extended to the direct printing of plaster layers, formed by mixing two reactive ink solutions.Mechanical Engineerin

Smoking and intention to quit in deprived areas of Glasgow: is it related to housing improvements and neighbourhood regeneration because of improved mental health?

Background: People living in areas of multiple deprivation are more likely to smoke and less likely to quit smoking. This study examines the effect on smoking and intention to quit smoking for those who have experienced housing improvements (HI) in deprived areas of Glasgow, UK, and investigates whether such effects can be explained by improved mental health. Methods: Quasi-experimental, 2-year longitudinal study, comparing residents’ smoking and intention to quit smoking for HI group (n=545) with non-HI group (n=517), adjusting for baseline (2006) sociodemographic factors and smoking status. SF-12 mental health scores were used to assess mental health, along with self-reported experience of, and General Practitioner (GP) consultations for, anxiety and depression in the last 12 months. Results: There was no relationship between smoking and HI, adjusting for baseline rates (OR=0.97, 95% CI 0.57 to 1.67, p=0.918). We found an association between intention to quit and HI, which remained significant after adjusting for sociodemographics and previous intention to quit (OR 2.16, 95% CI 1.12 to 4.16, p=0.022). We found no consistent evidence that this association was attenuated by improvement in our three mental health measures. Conclusions: Providing residents in disadvantaged areas with better housing may prompt them to consider quitting smoking. However, few people actually quit, indicating that residential improvements or changes to the physical environment may not be sufficient drivers of personal behavioural change. It would make sense to link health services to housing regeneration projects to support changes in health behaviours at a time when environmental change appears to make behavioural change more likely

Open Futures: an enquiry- and skills- based educational programme developed for primary education and its use in tertiary education

Open Futures is a transforming enquiry-based and skills-based system for education that is central to the curriculum, linking learning and life. It was developed to help children discover and develop practical skills, personal interests and values, which will contribute to their education and help to enhance their adult lives. Open Futures works in partnership with groups of schools in local clusters to develop a bespoke training programme, which extends the existing curriculum and nurtures independent learning through pupil-led approaches to personal learning. Schools benefit from the experience, knowledge and support of like-minded education professionals locally, nationally and internationally. Working with schools and their communities in the UK and India, Open Futures has been running with widespread success for 9 years. It now reaches more than 30,000 children in the UK. There is a body of independent evidence from primary and secondary education showing that both individual strands, as well as the complete Open Futures programme, significantly improve learner outcomes. We now wished to move Open Futures into the tertiary education sector. It was felt that an Open Futures approach to learning and teaching, particularly involving askit, would be beneficial to the community of learners at Central Bedfordshire Further Education College, rated Grade 2 by Ofsted in October 2013. Training has been in three areas so far: Construction, Public Services and Pathways (i.e. Learners with learning difficulties and disabilities). In all cases, there were significant positive impacts for learners and for teachers. As experience with Open Futures develops in the College, it should become clear how such a central enquiry-based and skills-based approach will help learners, and provide evidence for the use of Open Futures in tertiary education that could be used in other tertiary educational institutions

Bearing damage characteristics of fibre-reinforced countersunk composite bolted joints subjected to quasi-static shear loading

This paper studies the progression of damage in carbon fibre-reinforced polymer (CFRP) countersunk composite bolted joints (CBJs) with neat-fit clearance, subjected to quasi-static loading. Damage mechanisms, comprising of fibre buckling and breakage, matrix damage, shear damage and inter-laminar delamination within the CFRP composite parts of the joints have been studied. Load-displacement curves, X-ray and optical microscopic images in single- and three-bolt CBJs were used to investigate damage and deformation characteristics. The observations were then employed to further investigate the type of failure and the extent of damage. The evolution of damage within the composite parts was correlated to the failure characteristics of the joints: It was found that the type and extension of damage is strongly correlated with the ultimate failure load point of the joint in single-bolt CBJs. A combined inter/intra-laminar damage consisting of fibre cluster breakage, extensive fibre buckling, debonding and delamination was observed at the ultimate failure load. This study was then extended to three-bolt CBJ where damage surrounding each bolt and its corresponding failure load was strongly correlated: The final study showed that the ultimate failure point in single-bolt CBJ and the first-bolt-failure point in three-bolt CBJ correspond to the composite plies undergoing intra-laminar damage with the size reaching to the edge of the countersunk head. This damage developed extensively through the thickness of the composite parts underneath the countersink, and in the direction opposite to the loading direction. Outside the countersunk head, debonding and delamination were found to be the dominant damage driving mechanisms. Finally, a new design rule has been proposed to predict the response of multi-bolt joints (damage area and failure load) by using the response in single-bolt CBJ as an initial baseline

Nature and dynamics of late Miocene/early Pliocene Ice-Sheet grounding events on the Pacific margin of the Antarctic Pennisula outer continental shelf

Package-3 unconformities identified by Bart and Anderson (1995) were mapped to evaluate their glacial unconformity interpretation using a regional grid of single channel seismic data from the Antarctic Peninsula outer continental shelf. Detailed correlations show many crosscutting relationships within Package 3 such that the unconformities and units they bound are not regionally continuous across the margin. Comparison of Package-3 unconformities with the modern bathymetry reveals that cross-shelf trough and bank morphology is absent, which indicates that ice streams probably did not exist on the shelf during Package-3 time. On the continental shelf, only the middle part of Package 3 is sampled at ODP Leg 178 sites (1097 and 1103 on the southern and northern sectors of the margin, respectively.) Although mapping results do not uniquely require/preclude ice sheet grounding, taken together, the diamict lithology and crosscutting supports the interpretation of waxing and waning of grounded ice on the outer continental shelf. Chronostratigraphic resolution at Leg 178 sites on the continental shelf is too coarse to allow unconformity-to-unconformity correlations between Package-3 strata sampled at the two shelf drill sites. At most, fifteen (15) Package-3 glacial unconformities are found at any one location, and this represents the most conservative estimate of the maximum number of grounding events from the perspective of regional shelf stratigraphy. Basinward of the continental shelf, coeval section sampled on continental-rise drift 6 at ODP site 1095 exhibits distinct meter-scale bioturbation events, capping thick (up to 20 m) unbioturbated section, interpreted to result from \u3e30 glacial episodes. The large difference between the minimum estimate of shelf grounding events (15) and the number of glacial cycles deduced from drift lithology (30) suggests either 1) amalgamation of shelf glacial unconformities, or 2) lithologic alternations on the rise reflect phenomena unrelated to grounding events. Chlorite-smectite covariance at drift 6, interpreted to represent ~16 glacial episodes, shows much better correspondence to the minimum number of Package-3 glacial unconformities. However, the poor covariance between the two drift-derived proxies (bioturbation and clay mineralogy) demonstrates that one or both may be recording something other than grounding events on the adjacent shelf