R. Morgan, C.J. Sutcliffe and W. O’Neill
Describes the effects of the major process variables (Q‐switch pulse frequency, laser power, scan speed, scan spacing and scan length) on the production of single layer coupons…
Abstract
Describes the effects of the major process variables (Q‐switch pulse frequency, laser power, scan speed, scan spacing and scan length) on the production of single layer coupons. Results are compiled as a list of qualitative effects on the samples, such as degree of melting, shock compression effects, thermal stress cracking, etc. The results show that at certain pulse frequencies, evaporation recoil forces overcome the surface tension forces acting on the melt, improving cohesion compared to continuous wave (CW) lasing regime. The advantages lie in greater scan spacing and scan speeds enabling faster processing times for metallic objects built in this manner. The results also show the effect of power, scan speed, scan spacing and scan length on the morphology of the samples.
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C. Hauser, M. Dunschen, M. Egan and C. Sutcliffe
The purpose of this paper is to report on software development in which mathematical algorithms apply geometric transformations to digitised images in preparation for layer…
Abstract
Purpose
The purpose of this paper is to report on software development in which mathematical algorithms apply geometric transformations to digitised images in preparation for layer manufacturing by printing a binder onto a rotating powder substrate.
Design/methodology/approach
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. Consolidation occurs by infiltrating the powder layer with a binding agent deposited in droplet form using inkjet technology. During each rotation, the build platform falls away from a stationary doctor blade and print head assembly. This gives a continuous spiralled layer of powder with a constant layer pitch. To faithfully print digitised images onto a rotating substrate, polar and linear transformations have to be applied.
Findings
In support of this work, dimensional accuracy measurements of transformed printed images are reported and the measured results were found to be within ±0.2 mm of their predicted size. The experimental work is briefly extended to the printing of transformed images, using an aqueous binder, onto plaster powder to demonstrate the build speed capabilities of SGM. Primitive multiple layer parts built at speeds of 10 layers/min are reported.
Practical implications
From a practical standpoint, SGM has the potential to increase build speed by an order of magnitude over existing commercial rapid prototyping/manufacturing systems.
Originality/value
There is no commercial system available that allows high‐speed simultaneous deposition and processing of powder material and so this method could have implications in large batch manufacture.
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Frederick J. Brigham, Christopher Claude, Jason Chow, Colleen Lloyd Eddy, Nicholas Gage and John William McKenna
Four reputed leaders for the coming years in the field of special education for individuals with emotional and behavioral disorders (EBD) each with a slightly different…
Abstract
Four reputed leaders for the coming years in the field of special education for individuals with emotional and behavioral disorders (EBD) each with a slightly different perspective on the field were asked to respond independently to a prompt asking what does special education mean for students with EBD and what is being done and how do we maintain tradition? The contributors' responses to the prompt are presented and then summarized across the essays. A remarkable consistency emerges across the independent essays. In addition to the tradition of providing a free and appropriate education in the least restrictive environment, the contributors identify needs to support teachers serving this population. Needs in teacher training and the expertise required to meet the needs of individuals with EBD are outlined as well as potential contributions of technology to carry out specific tasks. We conclude with a call for increased advocacy for use of the knowledge that we currently possess and that which will soon be discovered to support students with EBD as well as their teachers. We also note that the contributors' names are listed alphabetically to acknowledge the equality of each person to the final product.
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S.R. Pogson, P. Fox, C.J. Sutcliffe and W. O’Neill
The relationship between the major process variables (laser power, laser scan speed, scan length, beam overlap and Q‐switch pulse frequency) of direct metal laser re‐melting and…
Abstract
The relationship between the major process variables (laser power, laser scan speed, scan length, beam overlap and Q‐switch pulse frequency) of direct metal laser re‐melting and their effect on the structure of single‐ and multi‐layer copper coupons has been investigated. The work successfully produced selectively fused copper powder layers and simple three‐dimensional copper structures with suitable laser parameters being identified for the production of parts, including thin‐walled cubic structures. It was shown that the specific energy density needed to melt thick powder beds was less than that to melt multi‐layer builds and that the type of substrate material used significantly affected the process parameters. Thus, the substrate and its thermal properties have a significant effect on the melt pool size and freezing rate.
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Amber L. Stephenson, Amy B. Diehl, Leanne M. Dzubinski, Mara McErlean, John Huppertz and Mandeep Sidhu
Women in medicine face barriers that hinder progress toward top leadership roles, and the industry remains plagued by the grand challenge of gender inequality. The purpose of this…
Abstract
Women in medicine face barriers that hinder progress toward top leadership roles, and the industry remains plagued by the grand challenge of gender inequality. The purpose of this study was to explore how subtle and overt gender biases affect women physicians, physician leaders, researchers, and faculty working in academic health sciences environments and to further examine the association of these biases with workplace satisfaction. The study used a convergent mixed methods approach. Sampling from a list of medical schools in the United States, in conjunction with a list of each state's medical society, the authors analyzed the quantitative survey responses of 293 women in medicine. The authors conducted ordinary least squares multiple regression to assess the relationship of gender barriers on workplace satisfaction. Additionally, 132 of the 293 participants provided written open-ended responses that were explored using a qualitative content analysis methodology. The survey results showed that male culture, lack of sponsorship, lack of mentoring, and queen bee syndrome were associated with lower workplace satisfaction. The qualitative results provided illustrations of how participants experienced these biases. These results emphasize the obstacles that women face and highlight the detrimental nature of gender bias in medicine. The authors conclude by presenting concrete recommendations for managers endeavoring to improve the culture of gender equity and inclusivity.
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Jane Hughes, Helen Chester, Caroline Sutcliffe, Chengqiu Xie and David Challis
– The purpose of this paper is to present a framework for examining variation in care coordination arrangements for older people.
Abstract
Purpose
The purpose of this paper is to present a framework for examining variation in care coordination arrangements for older people.
Design/methodology/approach
A multi-method approach was adopted combining analysis of secondary data and primary data. There were two stages: the development of the framework and its constituent attributes and indicators; and its validation from two perspectives: a meeting with managers and focus groups with practitioners. It was informed by an existing generic framework; subsequent policy guidance; data from an English national survey; previous research; and international literature.
Findings
The framework comprises 19 attributes each with indicators measuring performance relating to: organisational arrangements influencing service delivery; the performance of core tasks of care coordination; and differentiation within the process to distinguish between responses to different levels of need.
Originality/value
Care coordination arrangements in England are characterised by diversity. This paper provides a framework for evaluating local arrangements thereby highlighting strengths and where improvements are needed. It offers a means to promote programme fidelity. As such it has utility for both service commissioners and providers.
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Christina Victor, Ian Hastie, Georgina Christodoulou and Peter Millard
Despite the new ‘needs driven’ criteria for public funded admission to nursing homes, there remains concern that older people are entering such care inappropriately. However…
Abstract
Despite the new ‘needs driven’ criteria for public funded admission to nursing homes, there remains concern that older people are entering such care inappropriately. However, neither previous research or policy makers have sub‐divided such inappropriate entries into their constituent groups: those who are inappropriate because they are too independent and those who are inappropriate because they are too dependent. The aims of this study were to determine the extent of inappropriate nursing home admission amongst older people in nursing homes in six areas of England and Wales between 1995‐96. This was done through a retrospective case‐note review using a structured data‐collection pro forma. Although the study found no evidence of extensive inappropriate placement, extrapolation of these data suggests that 6,750 of those admitted to nursing care could have coped in a more independent environment. The inappropriately admitted group were more likely to have lived alone, be female, elderly and not to have seen a geriatrician. It is concluded that the most effective way to prevent such admissions would be to ensure the involvement of specialist geriatricians in the multidisciplinary team involved in admission decisions.
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Samuel Evans, Eric Jones, Peter Fox and Chris Sutcliffe
This paper aims to introduce a novel method for the analysis of open cell porous components fabricated by laser-based powder bed metal additive manufacturing (AM) for the purpose…
Abstract
Purpose
This paper aims to introduce a novel method for the analysis of open cell porous components fabricated by laser-based powder bed metal additive manufacturing (AM) for the purpose of quality control. This method uses photogrammetric analysis, the extraction of geometric information from an image through the use of algorithms. By applying this technique to porous AM components, a rapid, low-cost inspection of geometric properties such as material thickness and pore size is achieved. Such measurements take on greater importance, as the production of porous additive manufactured orthopaedic devices increases in number, causing other, slower and more expensive methods of analysis to become impractical.
Design/methodology/approach
Here the development of the photogrammetric method is discussed and compared to standard techniques including scanning electron microscopy, micro computed tomography scanning and the recently developed focus variation (FV) imaging. The system is also validated against test graticules and simple wire geometries of known size, prior to the more complex orthopaedic structures.
Findings
The photogrammetric method shows an ability to analyse the variability in build fidelity of AM porous structures for use in inspection purposes to compare component properties. While measured values for material thickness and pore size differed from those of other techniques, the new photogrammetric technique demonstrated a low deviation when repeating measurements, and was able to analyse components at a much faster rate and lower cost than the competing systems, with less requirement for specific expertise or training.
Originality/value
The advantages demonstrated by the image-based technique described indicate the system to be suitable for implementation as a means of in-line process control for quality and inspection applications, particularly for high-volume production where existing methods would be impractical.