59 research outputs found
Bridging Physics and Biology Teaching through Modeling
As the frontiers of biology become increasingly interdisciplinary, the
physics education community has engaged in ongoing efforts to make physics
classes more relevant to life sciences majors. These efforts are complicated by
the many apparent differences between these fields, including the types of
systems that each studies, the behavior of those systems, the kinds of
measurements that each makes, and the role of mathematics in each field.
Nonetheless, physics and biology are both sciences that rely on observations
and measurements to construct models of the natural world. In the present
theoretical article, we propose that efforts to bridge the teaching of these
two disciplines must emphasize shared scientific practices, particularly
scientific modeling. We define modeling using language common to both
disciplines and highlight how an understanding of the modeling process can help
reconcile apparent differences between the teaching of physics and biology. We
elaborate how models can be used for explanatory, predictive, and functional
purposes and present common models from each discipline demonstrating key
modeling principles. By framing interdisciplinary teaching in the context of
modeling, we aim to bridge physics and biology teaching and to equip students
with modeling competencies applicable across any scientific discipline.Comment: 10 pages, 2 figures, 3 table
Comparing large lecture mechanics curricula using the Force Concept Inventory: A five thousand student study
The performance of over 5000 students in introductory calculus-based
mechanics courses at the Georgia Institute of Technology was assessed using the
Force Concept Inventory (FCI). Results from two different curricula were
compared: a traditional mechanics curriculum and the Matter & Interactions
(M&I) curriculum. Post-instruction FCI averages were significantly higher for
the traditional curriculum than for the M&I curriculum; the differences between
curricula persist after accounting for factors such as pre-instruction FCI
scores, grade point averages, and SAT scores. FCI performance on categories of
items organized by concepts was also compared; traditional averages were
significantly higher in each concept. We examined differences in student
preparation between the curricula and found that the relative fraction of
homework and lecture topics devoted to FCI force and motion concepts correlated
with the observed performance differences. Limitations of concept inventories
as instruments for evaluating curricular reforms are discussed.Comment: 21 pages, 4 figures, submitted to Am. J. Phys. arXiv admin note:
substantial text overlap with arXiv:1112.559
Scanning Angle Plasmon Waveguide Resonance Raman Spectroscopy for the Analysis of Thin Polystyrene Films
Scanning angle (SA) Raman spectroscopy was used to characterize thin polymer films at a sapphire/50 nm gold film/polystyrene/air interface. When the polymer thickness is greater than ∼260 nm, this interface behaves as a plasmon waveguide; Raman scatter is greatly enhanced with both p- and s-polarized excitation compared to an interface without the gold film. In this study, the reflected light intensities from the interface and Raman spectra were collected as a function of incident angle for three samples with different polystyrene thicknesses. The Raman peak areas were well modeled with the calculated mean-square electric field (MSEF) integrated over the polymer film at varying incident angles. A 412 nm polystyrene plasmon waveguide generated 3.34× the Raman signal at 40.52° (the plasmon waveguide resonance angle) compared to the signal measured at 70.4° (the surface plasmon resonance angle). None of the studied polystyrene plasmon waveguides produced detectable Raman scatter using a 180° backscatter collection geometry, demonstrating the sensitivity of the SA Raman technique. The data highlight the ability to measure polymer thickness, chemical content, and, when combined with calculations of MSEF as a function of distance from the interface, details of polymer structure and order. The SA Raman spectroscopy thickness measurements agreed with those obtained from optical interferometery with an average difference of 2.6%. This technique has the potential to impact the rapidly developing technologies utilizing metal/polymer films for energy storage and electronic devices
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