1,832 research outputs found

    Droplet Spray Behavior of an Atomization-Based Cutting Fluid (ACF) System for Machining of Titanium Alloys

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    The aim of this research is to study droplet spray characteristics of an atomization-based cutting fluid (ACF) spray system including droplet entrainment angle and flow development regions with respect to three ACF spray parameters, viz., droplet and gas velocities, and spray distance. ACF spray experiments are performed by varying droplet and gas velocities. The flow development behavior is studied by modeling the droplets entrainment mechanism, and the density and distribution of the droplets across the jet flare. Machining experiments are also performed in order to understand the effect of the droplet spray behavior on the machining performances, viz., tool life/wear, and surface roughness during turning of a titanium alloy, Ti-6Al-4V. Experiments and the modeling of flow development behavior reveal that a higher droplet velocity and a smaller gas velocity result in smaller droplet entrainment angle leading to a gradual and early development of the co-flow with a smaller density and a better distribution of the droplet across the jet flare. Machining experiments also show that a higher droplet velocity, a lower gas velocity and a longer spray distance significantly improve the machining performances such as tool life and wear, and surface finish

    Investigating Miniature Electrodynamic Tethers and Interaction with the Low Earth Orbit Plasma

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106509/1/AIAA2013-5391.pd

    Investigating Miniaturized Electrodynamic Tethers for Picosatellites and Femtosatellites

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143110/1/1.A33629.pd

    Avalanche Dynamics in Wet Granular Materials

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    We have studied the dynamics of avalanching wet granular media in a rotating drum apparatus. Quantitative measurements of the flow velocity and the granular flux during avalanches allow us to characterize novel avalanche types unique to wet media. We also explore the details of viscoplastic flow (observed at the highest liquid contents) in which there are lasting contacts during flow, leading to coherence across the entire sample. This coherence leads to a velocity independent flow depth at high rotation rates and novel robust pattern formation in the granular surface.Comment: 5 pages, 3 figures in color, REVTeX4, for smaller pdfs see http://angel.elte.hu/~tegzes/condmat.htm

    Principles And Practices Fostering Inclusive Excellence: Lessons From The Howard Hughes Medical Institute’s Capstone Institutions

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    Best-practices pedagogy in science, technology, engineering, and mathematics (STEM) aims for inclusive excellence that fosters student persistence. This paper describes principles of inclusivity across 11 primarily undergraduate institutions designated as Capstone Awardees in Howard Hughes Medical Institute’s (HHMI) 2012 competition. The Capstones represent a range of institutional missions, student profiles, and geographical locations. Each successfully directed activities toward persistence of STEM students, especially those from traditionally underrepresented groups, through a set of common elements: mentoring programs to build community; research experiences to strengthen scientific skill/identity; attention to quantitative skills; and outreach/bridge programs to broaden the student pool. This paper grounds these program elements in learning theory, emphasizing their essential principles with examples of how they were implemented within institutional contexts. We also describe common assessment approaches that in many cases informed programming and created traction for stakeholder buy-in. The lessons learned from our shared experiences in pursuit of inclusive excellence, including the resources housed on our companion website, can inform others’ efforts to increase access to and persistence in STEM in higher education

    Mental health and the impact of ubiquitous technologies

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    This Theme issue focuses on the emerging research of ubiquitous technologies to support mental health. So far, the majority of work presented in the field of ubiquitous healthcare has focused on supporting people affected by somatic diseases. However, increasing number of diseases affecting mental health has prompted research on technologies to support people suffering from these diseases. This Theme issue provides a number of examples of research on the potential impact of ubiquitous technologies in the field of mental health
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