447 research outputs found
Comparing Network Centrality Measures of Non-Traditional Students in an Introductory Physics Class
The goal of this research was to compare different models of network influence for students. Two research questions were composed: 1. How do common centrality measures compare when ranking students\u27 network influence? 2. Do centrality values of non-traditional students show different trend than traditional students?https://corescholar.libraries.wright.edu/urop_celebration/1016/thumbnail.jp
Turbulent Mixing and Layer Formation in Double-Diffusive Convection: 3D Numerical Simulations and Theory
Double-diffusive convection, often referred to as semi-convection in astrophysics, occurs in thermally and compositionally stratified systems which are stable according to the Ledoux criterion but unstable according to the Schwarzschild criterion. This process has been given relatively little attention so far, and its properties remain poorly constrained. In this paper, we present and analyze a set of three-dimensional simulations of this phenomenon in a Cartesian domain under the Boussinesq approximation. We find that in some cases the double-diffusive convection saturates into a state of homogeneous turbulence, but with turbulent fluxes several orders of magnitude smaller than those expected from direct overturning convection. In other cases, the system rapidly and spontaneously develops closely packed thermo-compositional layers, which later successively merge until a single layer is left. We compare the output of our simulations with an existing theory of layer formation in the oceanographic context and find very good agreement between the model and our results. The thermal and compositional mixing rates increase significantly during layer formation and increase even further with each merger. We find that the heat flux through the staircase is a simple function of the layer height. We conclude by proposing a new approach to studying transport by double-diffusive convection in astrophysics
Network positions in active learning environments in physics
This study uses positional analysis to describe the student interaction
networks in four research-based introductory physics curricula. Positional
analysis is a technique for simplifying the structure of a network into blocks
of actors whose connections are more similar to each other than to the rest of
the network. This method describes social structure in a way that is comparable
between networks of different sizes and densities and can show large-scale
patterns such as hierarchy or brokering among actors. We detail the method and
apply it to class sections using Peer Instruction, SCALE-UP, ISLE, and
context-rich problems. At the level of detail shown in the blockmodels, most of
the curricula are more alike than different, showing a late-term tendency to
form coherent subgroups that communicate actively among themselves but have few
inter-position links. This pattern may be a network signature of active
learning classes, but wider data collection is needed to investigate.Comment: 17 pages, 10 figures; supplemental 10 pages, 9 figure
Students’ Use of Symmetry with Gauss’s Law
To study introductory student difficulties with electrostatics, we compared student techniques when finding the electric field for spherically symmetric and non-spherically symmetric charged conductors. We used short interviews to design a free-response and multiple-choice-multiple-response survey that was administered to students in introductory calculus-based courses. We present the survey results and discuss them in light of Singh\u27s results for Gauss\u27s Law, Collins and Ferguson\u27s epistemic forms and games, and Tuminaro\u27s extension of games and frames
Enriching gender in PER: A binary past and a complex future
In this article, we draw on previous reports from physics, science education,
and women's studies to propose a more nuanced treatment of gender in physics
education research (PER). A growing body of PER examines gender differences in
participation, performance, and attitudes toward physics. We have three
critiques of this work: (1) it does not question whether the achievements of
men are the most appropriate standard, (2) individual experiences and student
identities are undervalued, and (3) the binary model of gender is not
questioned. Driven by these critiques, we propose a conception of gender that
is more up-to-date with other fields and discuss gender-as-performance as an
extended example. We also discuss work on the intersection of identities [e.g.,
gender with race and ethnicity, socioeconomic status, lesbian, gay, bisexual,
and transgender (LGBT) status], much of which has been conducted outside of
physics. Within PER, some studies examine the intersection of gender and race,
and identify the lack of a single identity as a key challenge of "belonging" in
physics. Acknowledging this complexity enables us to further critique what we
term a binary gender deficit model. This framework, which is implicit in much
of the gender-based PER, casts gender as a fixed binary trait and suggests that
women are deficient in characteristics necessary to succeed. Alternative models
of gender allow a greater range and fluidity of gender identities, and
highlight deficiencies in data that exclude women's experiences. We suggest new
investigations that diverge from this expanded gender framework in PER.Comment: 27 pages, accepted to Phys. Rev. Special Topics - PE
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