7,410 research outputs found
The Effect of Student Learning Styles on the Learning Gains Achieved When Interactive Simulations Are Coupled with Real-Time Formative Assessment via Pen-Enabled Mobile Technology
This paper describes results from a project in an undergraduate engineering
physics course that coupled classroom use of interactive computer simulations
with the collection of real-time formative assessment using pen-enabled mobile
technology. Interactive simulations (free or textbook-based) are widely used
across the undergraduate science and engineering curriculia to help actively
engaged students increase their understanding of abstract concepts or phenomena
which are not directly or easily observable. However, there are indications in
the literature that we do not yet know the pedagogical best practices
associated with their use to maximize learning. This project couples student
use of interactive simulations with the gathering of real-time formative
assessment via pen-enabled mobile technology (in this case, Tablet PCs). The
research question addressed in this paper is: are learning gains achieved with
this coupled model greater for certain types of learners in undergraduate STEM
classrooms? To answer this, we correlate learning gains with various learning
styles, as identified using the Index of Learning Styles (ILS) developed by
Felder and Soloman. These insights will be useful for others who use
interactive computer simulations in their instruction and other adopters of
this pedagogical model; the insights may have broader implications about
modification of instruction to address various learning styles.Comment: 6 pages 2 tables and 1 figur
First Detection of a Strong Magnetic Field on a Bursty Brown Dwarf: Puzzle Solved
We report the first direct detection of a strong, 5 kG magnetic field on the
surface of an active brown dwarf. LSR J1835+3259 is an M8.5 dwarf exhibiting
transient radio and optical emission bursts modulated by fast rotation. We have
detected the surface magnetic field as circularly polarized signatures in the
819 nm sodium lines when an active emission region faced the Earth. Modeling
Stokes profiles of these lines reveals the effective temperature of 2800 K and
log gravity acceleration of 4.5. These parameters place LSR J1835+3259 on
evolutionary tracks as a young brown dwarf with the mass of 554 M and age of 224 Myr. Its magnetic field is at least 5.1 kG and covers
at least 11% of the visible hemisphere. The active region topology recovered
using line profile inversions comprises hot plasma loops with a vertical
stratification of optical and radio emission sources. These loops rotate with
the dwarf in and out of view causing periodic emission bursts. The magnetic
field is detected at the base of the loops. This is the first time that we can
quantitatively associate brown dwarf non-thermal bursts with a strong, 5 kG
surface magnetic field and solve the puzzle of their driving mechanism. This is
also the coolest known dwarf with such a strong surface magnetic field. The
young age of LSR J1835+3259 implies that it may still maintain a disk, which
may facilitate bursts via magnetospheric accretion, like in higher-mass T
Tau-type stars. Our results pave a path toward magnetic studies of brown dwarfs
and hot Jupiters.Comment: ApJ, in pres
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