1,091 research outputs found

    Santa Clara University College of Law

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    Santa Clara University College of Law

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    Design research in early literacy within the zone of proximal implementation

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    Despite intentions to the contrary, insights on pedagogically appropriate innovations with representative teachers in everyday school settings are severely limited. In part, this is because (design) research is often conducted at the bleeding edge of what is possible, exploring innovative uses of new technologies and/or emerging theories, while insufficient research and development work focuses on what is practical, today. This leaves a problematic gap between what could be useful research in theory, and what can be useful research in practice. This paper calls for (design) researchers to attend to factors that determine if and how innovations are understood, adopted and used by teachers and schools, and gives one example of how this was tackled in the domain of early literacy. Across ten studies, researchers collected data that helped shape an intervention that can be implemented by representative teachers, for diverse learners, in varied school settings

    High-resolution imaging reveals indirect coordination of opposite motors and a role for LIS1 in high-load axonal transport

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    High-resolution particle tracking shows a specific role for the dynein regulatory factor LIS1 in high-load axonal transport of large vesicles but no evidence for mechanical activation of opposite-directed motors

    Development of an autonomous aerosol sampler for ocean buoys and land sites

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    The authors have successfully designed, built and tested an aerosol sampler which is capable of collecting, in an unattended manner, a time-series set of aerosol samples (aerosol-embedded filters) from moored ocean buoys and remote areas on land. Research on aerosols, in particular, and atmospheric chemistry, in general, has not been previously attempted from buoys. Aerosols entering and leaving the ocean play an important role in climate change, ocean productivity, pollutant transport and atmospheric optics. This report discusses (1) the scientific applications of a buoy-mounted aerosol sampler, (2) the advantages of using buoys as research platforms and (3) the authors' new instrument. Also discussed are the results of a four month test of the aerosol sampler on the AEROCE (Atmosphere/Ocean Chemistry Experiment) tower in Bermuda and the results of a three month test on a buoy moored in Vineyard Sound off Woods Hole, MA USA. The direct comparison between WHOI filters and AEROCE filters from the Bermuda tower is very encouraging as the Fe concentrations of aerosols compare to within 10-15% over a wide range of values. Aerosol sampling from a buoy moored in coastal waters was successfully tested under a variety of atmospheric and oceanic conditions.Funding was provided by the National Science Foundation through Grant No. OCE-943212

    Bringing Particle Scale Properties into Descriptions of Powder Behavior through the Enhanced Centrifuge Method

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    Inconsistent powder behavior introduces problems such as agglomeration, poor flowability, dust hazards, and segregation that decrease efficiency in powder processing environments. Understanding how a powder interacts with a surface at the particle scale provides insight into how to accommodate individual particle properties and avoid process deficiencies. This project uses an enhanced centrifuge technique to evaluate the adhesion between a stainless-steel surface and a powder comprised of fluorescent particles. Particles are deposited onto stainless steel plates which are rotated in a centrifuge. The adhesion properties are monitored by tracking the rotational speed at which particles of a known size are removed from the steel. To model the adhesion, a simulator was produced in MATLAB to map an ideal model to the experimental observations. In reality, the particles and steel are rough, and the particles are nonuniform in shape. The ideal case assumes the particles are smooth spheres and the steel is smooth. A modified van der Waals force model describes the observed forces. Within this model, a Hamaker constant, which usually describes only the effect of composition on the van der Waals force, is tuned to also describe the effects of the non-uniformity of the particles. This creates a distribution of ‘effective Hamaker constants’ that describes particle scale effects on the adhesion between the bulk powder and the stainless steel. This approach will allow industry to account for the effects of surface roughness, particle shape, and particle size when designing powder processing operations

    Extending KIDs to the Mid-IR for Future Space and Suborbital Observatories

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    The galaxy evolution probe (GEP) is a concept for a probe-class space observatory to study the physical processes related to star formation over cosmic time. To do so, the mid- and far-infrared (IR) spectra of galaxies must be studied. These mid- and far-IR observations require large multi-frequency arrays, sensitive detectors. Our goal is to develop low NEP aluminum kinetic inductance detectors (KIDs) for wavelengths of 10–400 μm for the GEP and a pathfinder long-duration balloon (GEP-B) that will perform precursor GEP science. KIDs for the lower wavelength range (10–100 μm) have not been previously implemented. We present an absorber design for KIDs sensitive to wavelengths of 10 μm shown to have around 75–80% absorption efficiency through ANSYS HFSS (high-frequency structure simulator) simulations, challenges that come with optimizing our design to increase the wavelength range, initial tests on our design of fabricated 10 μm KIDs, and theoretical NEP calculations

    Status of SuperSpec: A Broadband, On-Chip Millimeter-Wave Spectrometer

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    SuperSpec is a novel on-chip spectrometer we are developing for multi-object, moderate resolution (R = 100 - 500), large bandwidth (~1.65:1) submillimeter and millimeter survey spectroscopy of high-redshift galaxies. The spectrometer employs a filter bank architecture, and consists of a series of half-wave resonators formed by lithographically-patterned superconducting transmission lines. The signal power admitted by each resonator is detected by a lumped element titanium nitride (TiN) kinetic inductance detector (KID) operating at 100-200 MHz. We have tested a new prototype device that is more sensitive than previous devices, and easier to fabricate. We present a characterization of a representative R=282 channel at f = 236 GHz, including measurements of the spectrometer detection efficiency, the detector responsivity over a large range of optical loading, and the full system optical efficiency. We outline future improvements to the current system that we expect will enable construction of a photon-noise-limited R=100 filter bank, appropriate for a line intensity mapping experiment targeting the [CII] 158 micron transition during the Epoch of ReionizationComment: 16 pages, 10 figures, Proceedings of the SPIE Astronomical Telescopes + Instrumentation 2014 Conference, Vol 9153, Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VI
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