Noise due to rotor-turbulence interaction

A procedure for calculating the noise due to turbulent inflow to a propeller or helicopter rotor in hover is summarized. The method is based on a calculation of noise produced by an airfoil moving in rectilinear motion through turbulence. At high frequency the predicted spectrum is broadband, while at low frequency the spectrum is peaked around multiples of blade passage frequency. The results of a parametric study of the variation of the noise with rotor tip speed, blade number, chord, turbulence scale, and directivity angle are given. A comparison of the theory with preliminary experimental measurements shows good agreement

BENEFITS AND BARRIERS OF ONLINE SCIENCE ENGAGEMENT: AUDIENCE AND PRESENTER EXPERIENCES OF 2020 NATIONAL SCIENCE WEEK

Online engagement has unique benefits and challenges compared to face-to-face delivery, and requires a different approach and design considerations to take advantage of its different capabilities (Roddy et al., 2017). To reap the potential benefits of online engagement, there is a need to understand what the challenges of digital platforms are, and how they can be used to the best of their ability. Building on preliminary data presented at ACSME 2020 (McRae et al., 2020), this work presents additional analysis from interviews with 17 presenters and 22 audience members from 2020 National Science Week. The data from our study provide insights into best practice for online delivery of science education and outreach and highlight challenges within this format. We discuss how to enhance benefits such as the ease and flexibility provided by the online environment, and new interaction or production modes enabled by the online format. We also explore the barriers associated with the learning curve of new platforms, and more abstract issues such as the sense that online engagement is “missing something” compared to face-to-face delivery. Through the lenses of benefits and barriers of online engagement, we explore implications for educators and communicators working in the online environment. REFERENCES McRae, O. F., Downing, E., Motion, A., O’Reilly, C., & Pullen, R. (2020). A new ecosystem of online science: Online events as a tool for public engagement in science. Proceedings of The Australian Conference on Science and Mathematics Education, 0(0), 56. Roddy, C., Amiet, D. L., Chung, J., Holt, C., Shaw, L., McKenzie, S., Garivaldis, F., Lodge, J. M., & Mundy, M. E. (2017). Applying Best Practice Online Learning, Teaching, and Support to Intensive Online Environments: An Integrative Review. Frontiers in Education, 2. https://doi.org/10.3389/feduc.2017.0005

Local peace agreement in Abyei: achievements, challenges and opportunities

In February 2016, after a series of meetings between Ngok Dinka and Misseriya chiefs, a peace agreement was signed in Noong (west of Abyei). The local mediation was initiated in 2015 by Chief Nyuon Pagot, after a lack of cooperation between the two communities since the 2011 Abyei conflict. During this period, Concordis, an international non-governmental organisation (NGO), became involved to provide logistical support, and to help facilitate the meetings. The main implementation mechanism for the 2016 agreement was the formation of the Joint Community Peace Committee (JCPC) comprised of 10 Ngok Dinka and 10 Misseriya. This governing body’s functions included coordinating with UNISFA, organising migration conferences, supporting conflict resolution, ruling on compensation, and overseeing the work of its sub-committees, including the community police committee, a court, and a committee on trade. There is also a detention centre (two containers) provided by UNISFA. The agreement and JCPC have been lauded for reducing the number of killings and incidences of violence conflict. Peaceful pastoralist migrations into the Abyei area are now taking place

Description of the previously unknown male of Systropha (Austrosystropha) macronasuta (Hymenoptera: Halictidae: Rophitinae) from Kenya

We describe and illustrate for the first time the previously unknown male of Systropha (Austrosystropha) macronasuta Strand.  We provide a species diagnosis and modified couplets of the recent identification key to allow for easy identification of this sex.  Based on the first record of S. macronasuta from the African mainland, we discuss the distribution of the species

Xray Tomographic Microscopic Studies a Resin Embedded Paint Sample from a Mechanical Failing Area in the Floor Tiles of The Art of Painting by Johannes Vermeer (1632-1675)

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 - August 5, 201