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The paper aims to evaluate mechanisms for silicon overfilling including volume expansion of silicon on solidification for composite silicon/silicon carbide (SiC) objects generated using post‐process infiltration of selective laser sintered (SLS) SiC preforms.

Overfilling was characterized through geometrical means and microscopy, and results were used for further study and discussion of overfilling mechanisms.

Silicon overfilling in silicon infiltrated SLS SiC parts is attributed primarily to its infiltrant silicon volume expansion on solidification. Si/SiC composites were found to be thermally stable with good material bonding.

Silicon as an infiltrant is unusual as it expands on solidification, whereas most infiltrants contract. Overfilling during infiltration of SLS porous performs is therefore not considered to be prevalent.

This paper provides an examination of the value of silicon as an infiltrant material for SLS SiC preforms. Various mechanisms are presented for volume change during post‐process infiltration of indirect SLS non‐metallic performs.

The purpose of this paper is to compare different powder metallurgy (PM) processes to produce ceramic parts through additive manufacturing (AM). This creates the potential to rapidly shape ceramic parts with an almost unlimited shape freedom. In this paper, alumina (Al₂O₃) parts are produced, as Al₂O₃ is currently the most commonly used ceramic material for technical applications.

Variants of the following PM route, with indirect selective laser sintering (indirect SLS) as the AM shaping step, are explored to produce ceramic parts: powder synthesis, indirect SLS, binder removal and furnace sintering and alternative densification steps.

Freeform-shaped Al₂O₃ parts with densities up to approximately 90 per cent are obtained.

The resulting Al₂O₃ parts contain inter-agglomerate pores. To produce higher-quality ceramic parts through indirect SLS, these pores should be avoided or eliminated.

The research is innovative in many ways. First, composite powders are produced using different powder production methods, such as temperature-induced phase separation and dispersion polymerization. Second, four different binder materials are investigated: polyamide (nylon-12), polystyrene, polypropylene and a carnauba wax – low-density polyethylene combination. Further, to produce ceramic parts with increased density, the following densification techniques are investigated as additional steps of the PM process: laser remelting, isostatic pressing and infiltration.

The purpose of this paper is to develop a methodology to achieve successful infiltration of indirect selective laser sintered steel components with ferrous alloys and thereby to produce fully ferrous components with desirable properties while preserving part geometry.

The approach is to generate a “green” part by selective laser sintering (SLS) of ferrous powder mixed with a transient binder in a commercial polymer machine. This part is post‐processed to burn off the transient binder (brown part) and to infiltrate the porous structure with a lower melting point ferrous metal. A critical consideration is loss of part structural integrity by over‐melting after infiltration as a result of chemical diffusion of alloying elements, principally carbon. A predictive model defining the degree of success of infiltration based on chemical equilibrium may be used to select the temperature for infiltration.

The infiltration temperature should be set such that the equilibrium solid fraction of the final infiltrated part is at least equal to or greater than the brown part solid fraction.

Infiltration temperature must be carefully controlled to prevent melting of the brown part. Effect of alloying elements other than carbon on equilibrium solid fraction is not considered while constructing the predictive model.

This approach can be used to obtain fully ferrous parts with complex geometry and desirable properties using a low‐cost polymer SLS machine.

The purpose of this paper is to report on the use of a combination of selective laser sintering (SLS) and vacuum casting to create plastic composites made by additive manufacturing.

The research has been carried out by approaching a new concept of the final part consistent in a plastic component, where the main body is made by SLS and the internal long fibres for reinforcing are made by vacuum casting of high-resistance epoxy resin. The part is designed for optimal number and distribution of the internal fibres taking into account the target relative stiffness (N/mm*kg). The methodology is applied to a pedal clutch of a car which has been tested in an equipment for fatigue and durability, being compared to the correspondent design for injection moulding.

Research has proven that the approach introduces relevant improvement in mechanical properties of the base resin consistent in PA 3200GF (EOS), reinforced by internal long fibres of resin VG SP5. Experiments showed significant increase of stiffness in the pedal clutch made under this procedure, where the stiffness was 77 per cent higher than the conventional SLS part and only 11.7 per cent lower than the one made by injection moulding of PA 66 with 50 per cent fibreglass.

The developed method introduces an alternative procedure for increasing the mechanical properties of plastic parts developed in SLS. Optimal orientation and distribution of long fibres clearly achieves better mechanical properties at low cost.

Parkruns are weekly, free, community-based, 5 km runs around open spaces, with a growing body of research indicating their social, physical and psychological benefits. Thirty-one custodial establishments in England and Wales regularly offer parkruns. The purpose of this paper is to consider prisoners' experiences of parkrun in custodial settings, and these are discussed in the context of the evidence base regarding parkrun in the community and the wider literature on prison sport, desistance, and rehabilitation culture.

Using an inductive, qualitative approach, data was collected at three English prisons, via semi-structured interviews with 24 adult male prisoners who participated in parkrun. Data was subjected to thematic analysis.

In total, five themes reflecting positive experiences associated with custodial parkrun were identified: connection with others; healthy living; a safe and predictable exercise environment; a sense of purpose; and a re-humanising experience. Factors appearing frequently in the wider parkrun research are present in the perceptions of parkrunners in custody. In addition, factors deemed important to desistance and promoting a rehabilitation culture were also found in the experiences of the sample.

The work emphasises the successes of His Majesty’s Prison and Probation Service (HMPPS) and parkrun working in partnership to support custodial events. By highlighting the positive experiences of custodial parkrun on prisons and prisoners, the authors anticipate that their findings may encourage further sites to consider launching parkrun events and prompt existing sites to consider their events in line with efforts to promote desistance and a rehabilitation culture.

To the best of the authors’ knowledge, this is the first paper to explore custodial parkrun. The findings indicate that custodial parkrun supports HMPPS strategic goals by offering an opportunity for prisons to promote desistance.

This paper describes qualitative research evaluating the impacts of parkrun in a female prison. The extended methodology section explains why HMPPS psychologists have been ideally suited to investigate custodial parkrun whilst successfully partnering with a range of stakeholders, conferring benefits that could not have been achieved in any other way.

Purposive sampling resulted in 15 semi-structured interviews with prisoner parkrunners and volunteers at a women’s prison in England.

A range of highly positive parkrun experiences were described, which were grouped into four themes with sub-themes; improved mental and physical health, a sense of purpose, enhanced connections to others and stabilisation in prison. Women struggled when custodial parkrun was inconsistently delivered.

Custodial parkrun offers an opportunity for women to develop factors underpinning health and well-being, harnesses elements which engage women in physical activity and mitigates some gendered barriers to exercise. The findings also describe factors which are important to desistance, the development of a rehabilitation culture, self-determination theory (Ryan and Deci, 2000) and a trauma-informed approach. The opportunity for women to participate in parkrun through the gate may offer an important and sustainable “catalyst for change” (Maruna, 2001, p. 96).

The paper discusses how parkrun might be further utilised across the female prison estate. It adds to the evidence base regarding the benefits of physical activity for women, which might be considered when developing a sports strategy specific to the female estate. Additionally, HMPPS managers hoping to further develop the rehabilitation culture in their establishment might be persuaded as to the benefits of parkrun in this regard. Finally, the work provides an exemplar of how HMPPS psychologists can work with stakeholders to enhance practice evaluations.

This is only the second published research paper focusing on the impacts of parkrun in the custodial estate, and the first looking at women. Additionally, its inclusion in this Special Edition mean it is among the first published works describing how HMPPS psychologists can successfully partner with stakeholders to support evidence-based practice.

The Sno‐cat “Haywire” one of four used in Dr. Vivian Fuchs' 2,150 mile journey over Antarctic snow and ice has been presented to the British Petroleum Company in appreciation of the contribution made by the Company to the success of the expedition. The Company provided at their own expense, all petroleum fuels and lubricants for the party from the U.K. as well as that led by Sir Edmund Hilary from New Zealand. They also commissioned at their own expense a film record in colour of the expedition which will be ready by the late summer and B.P's. share of the proceeds from the commercial screenings will be placed at the disposal of the Trans‐Antarctic Expedition.

Nonprofit organisations (NPOs) are an increasingly fundamental part of our society. Meeting rising demand requires NPOs to attract enough resources, especially volunteers, to enable service delivery. This paper aims to adopt a novel theoretical lens to reframe this marketing challenge to inform practice and extend theory.

Practice-based exploration of a volunteer-enabled NPO, parkrun, through in-depth interviews and secondary source analysis.

The research identified that the brand community connects volunteers through three inter-connected levels. The big idea of parkrun, the focal brand, resonated with people through being “on their wavelength”, something they believed in. The local, physical event meant engagement was “on their patch”, anchored in place. Finally, the brand community enables people to volunteer “on their terms”, with fluid roles and flexible levels of commitment.

Not all NPOs have service beneficiaries who are able to volunteer, services with different volunteering roles, or operate through a local physical presence. However, taking a focal brand approach to consider the brand community through which people volunteer for an NPO, the practices that reinforce that community, and how to offer volunteers significantly greater flexibility in both role and commitment presents an opportunity for NPOs to rethink how volunteering works for them in the future.

Clear recommendations for practice include the opportunity to integrate service beneficiary with service delivery enabler (volunteer) to strengthen the implicit social contract, increasing participation to deepen the social identity felt towards the brand, and key practices that reduce barriers to volunteering.

The paper extends volunteering theory from the traditional individual needs approach to a focal brand community perspective. The marketing challenge of attracting volunteer resources to NPOs is understood through rethinking the boundaries between service beneficiaries and service enablers, anchored in social identity theory. It provides clear recommendations for practice through reframing the recruitment challenge.