Characterization and recyclability of 304L stainless steel powder for use in the selective laser melting process

Powder-bed fusion refers to a subset of additive manufacturing (AM) methods which successively melts and solidifies selected regions within a powder bed on a layer-by-layer basis to construct components directly from computer-aided design files. Laser Powder-Bed Fusion (L-PBF) is a process among the powder-bed fusion techniques that utilizes a laser to consolidate particles into a material with little porosity. During the L-PBF process, the large energy input from the laser causes the production of ejecta in the form of laser spatter and condensate, both of which have the potential to settle in the surrounding powder bed compromising its reusability. In order to better understand the impact of ejecta on powder recyclability, samples of 304L laser spatter and condensate were characterized in terms of morphology, chemistry, and microstructure. Differences between ejecta and virgin powder were used as a basis for understanding the evolution in 304L powder properties with reuse in the L-PBF process over the course of 7 iterations, which revealed an improvement in flowability with recycling. The effects of evolving powder properties on the tensile and impact toughness properties were also assessed for capturing possible deterioration in mechanical performance. Due to the improvement in powder flowability during recycling, the effects of alterations in the particle size were further investigated using the Discrete Element Method (DEM). Through development of a mathematical definition of spreadability, differences in the particle size distribution as well as recoating velocity and layer thickness revealed changes in the powder-bed quality providing crucial knowledge of the mechanisms behind the powder spreading process --Abstract, page iv

PSR B0809+74: Understanding Its Perplexing Subpulse-separation (P2) Variations

The longitude separation between adjacent drifting subpulses, $P_2$, is roughly constant for many pulsars. It was then perplexing when pulsar B0809+74 was found to exhibit substantial variations in this measure, both with wavelength and with longitude position within the pulse window. We analyze these variations between 40 and 1400 MHz, and we show that they stem primarily from the incoherent superposition of the two orthogonal modes of polarization.Comment: Submitted for publication Astronomy and Astrophysic

Land Protection and Habitat Restoration as Catalysts for Sustained Community Engagement at the Roslindale Wetlands Urban Wild

The Roslindale Wetlands “Urban Wild,” a 10-acre forested wetland in the heart of Boston, Massachusetts, is the backdrop for a compelling story of land preservation and habitat restoration as primary drivers for sustained community engagement. Originally identified for residential development, this patchwork of City and private land was long neglected and degraded by incompatible adjacent development and illegal dumping. In 2005, the community group Roslindale Wetlands Task Force (RWTF) was formed to start the long, gradual process of cleaning up and advocating for full preservation of the site. However, between 2019 and 2023, an alignment of several strategic joint planning ventures between the RWTF, the City of Boston, and Mass Audubon accelerated efforts and culminated in a giant leap forward. By 2023, the majority of the site was permanently protected and was ecologically restored through a $1 million City capital renovation investment. These milestone achievements, in turn, have recharged long-term community organizing and site stewardship efforts and contributed to a wider embrace of this nature park by Bostonians

Confusion about collusion: working together and academic integrity

An increasing emphasis on developing students' transferable skills, such as group working and IT, is creating challenges in ensuring the academic integrity of individually assessed coursework. This study investigated the frequency with which students engaged in a range of study behaviours for individual assignments, with a focus on the extent to which they exchanged information or worked in informal study groups. Over 1000 responses were gathered from students at pre‐ and post‐92 universities engaged in either business or psychology degrees. Four behavioural factors emerged from the data: trust, cooperation, use of IT and conscientious practices. Results indicated that students engage in practices relying on trust and cooperation less often than other practices, implying a concern with avoiding issues of academic misconduct. This was supported by focus group discussions where students described their strategies for working together whilst ensuring the quality and integrity of their own work. Comparisons between academic disciplines revealed that business students were more likely to engage in sharing and group‐work behaviours than psychology students, as were students at the post‐92 university. Comparisons between years found no significant differences. Recommendations are made for improving student understanding of collusion whilst still encouraging the development of skills important to employability

Legislative Update

The Legislative Update exists to inform the reader of various state and federal laws passed during the 2021-2022 legislative sessions. More specifically, the statutes discussed below relate to alternative dispute resolution (“ADR”) in its many forms. This is an annual update compiled and written by the Journal of Dispute Resolution’s Associate Members and edited by the Associate Editor-in-Chief. This year represented a wide mix of laws passed—some related to health and safety in a post-pandemic world; others posed solutions to problems relevant before the COVID-19 pandemic. Usually, the Legislative Update is limited exclusively to state legislation. We decided to include federal given the substantial impact the bills would have on arbitration and dispute resolution more broadly

Impact of Integrating a Unified Population Health and Systems Thinking Curriculum into a PA Program

Purpose This study shows the impact of a 3-part population health and interprofessional education (IPE) curriculum on Physician Assistant (PA) students’ knowledge and experience of population health and systems thinking (PHST) and to promote a team-based approach to patient care and improve patient health and preventative services. Methods Human Resources and Services Administration funded a 5-year Primary Care and Training Enhancement grant in PHST. With this funding, the Department of Family and Community Medicine developed a three-part plan emphasizing interprofessional learning. The impact was measured using a 22-item survey measuring knowledge and experience of PHST delivered to PA students annually. Survey responses were statistically compared across phases. Results There were 394 student responses analyzed comprising of 36.3% phase I, 38.1% phase II, and 25.6% phase III. After exposure to the PHST curriculum, students were significantly more likely to report choosing primary care (40% phase I to 54% phase III; p=0.0073). Knowledge and experience in all 13 educational goals significantly increased from phase I to phase III (ps \u3c 0.0001) with only 13% of PA students reporting no current knowledge by phase III. PA students’ reported need for additional training significantly decreased (ps \u3c 0.01), but an average of 75% of phase III students still reported needing additional training across the 13 educational goals. Conclusion The enhanced curriculum, emphasizing interprofessional collaboration, delivered in the PA program was effective in providing experiences and applying the knowledge surrounding PHST, which is consistent with other educational strategies in population health education. This study validates the need for continued education and training with the integration of PHST in the education of future clinicians being extremely vital for continued efforts in improving health outcomes for all patients

Bounding the graviton mass with binary pulsar observations

By comparing the observed orbital decay of the binary pulsars PSRB1913+16 and PSRB1534+12 to that predicted by general relativity due to gravitational-wave emission, we are able to bound the mass of the graviton to be less than $7.6\times10^{-20} \text{eV}/c^2$ at 90% confidence. This is the first such bound to be derived from dynamic gravitational fields. It is approximately two orders of magnitude weaker than the static-field bound from solar system observations, and will improve with further observations.Comment: 9 pages, 1 figure. Presented at Fourth Edoardo Amaldi Conference on Gravitational Waves, Perth, 200

A model for exploring student understandings of plagiarism

A clear understanding of how students view plagiarism is needed if the extensive efforts devoted to helping them engage in high-quality scholarship are to be worthwhile. There are a variety of views on this topic, but theoretical models to integrate the literature, take account of international differences and guide practitioners are limited. Using a large, international student sample, this paper presents just such a model. More than 2500 university students in the UK and Australia completed a questionnaire rating the perceived ‘seriousness' of various plagiarism-related actions in an individual assignment. Factor analysis identified three underlying themes: dishonest acts, poor referencing, and group work. Group comparisons indicated statistically significant differences in student understanding dependent on previous region of study, current faculty/school and level of study, with the former two emerging as more influential than the latter. This three-factor model provides practitioners with a methodology for integrating the many different studies in the area and gaining a broader overview of student understanding of plagiarism. In particular, it highlights how students consider plagiarism related to group work to be far less serious than other types. Given the increasing emphasis on group work in higher education, the implications of this for policy and practice are discussed. Importantly, the study also notes that effect sizes were small, suggesting that findings in this study, as in other studies, may not represent substantive differences in student perceptions. A single, universal approach to educating students about plagiarism may be as effective as approaches tailored to the individual's background