Spectroscopy Using Short-Path Surface Plasmon Dispersion

A miniature surface-plasmon based spectrometer is presented for both the near zone and the far zone. In the near zone four different experiments have been completed with this system. It will be shown that with 632, 614, 543, and 440 nm incident lasers upon the system there is good agreement between experimental and theoretical transmission spectra. This system is shown to provide transmission spectra of different broad band-pass, glass filters across the visible wavelength range with high stray-light rejection at low resolution. These spectra are compared to those taken with a commercial spectrophotometer. Spectra of solutions of the laser dye Coumarin 540A are also prepared with the solvent methanol. Absorption spectra of different concentrations of this solution are shown. The system can distinguish between the absorption of the different solutions used in the work. Lastly, an absorption spectrum of chlorophyll extracted from a spinach leaf is shown and compared to the spectrum obtained with a commercial spectrophotometer. Although this is not the first time this experiment has been set up, these are the first successful production of spectral data using the near field surface plasmon specrtrometer. The surface plasmon spectrometer in the far field is also presented. This set up can similarly be used as a spectrometer or to determine the optical properties of materials by operation as a biosensor. Several initial test results and future ideas for this device are also presented

Experimental Measurements of Clothes Dryer Drum Heat and Mass Transfer Effectiveness

Accurate system modeling of a clothes dryer requires a drum component that displays correct trends with respect to changing conditions. In this work, a model of drum heat and mass transfer effectiveness is adopted. Within this framework, experimental measurements of drum effectiveness are investigated with respect to several variables: drum volume, load mass, cloth type, drum volumetric air flow rate, and drum entering air temperature. These data can inform the modeling and simulation of any clothes dryer with horizontal-axis, axial-flow tumble-type clothes dryer drum

Online test administration results in students selecting more responses to multiple-choice-multiple-response items

We developed the Physics Inventory of Quantitative Literacy (PIQL) to assess students\u27 quantitative reasoning in introductory physics contexts. The PIQL includes several multiple-choice-multiple-response (MCMR) items (i.e., multiple-choice questions for which more than one response may be selected) as well as traditional single-response multiple-choice items. In this paper, we discuss differences in performance on MCMR items that seems to result from differences in administration method (paper versus online). In particular, we find a tendency for clickiness in online administration: students choose more responses to MCMR items when taking the electronic version of the assessment. Student performance on single-response multiple-choice items was not affected by administration method. These results suggest that MCMR items may provide a unique opportunity to probe differences in online and on-paper administration of low-stakes assessments. © 2023 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article\u27s title, journal citation, and DOI

Online administration of a reasoning inventory in development

We are developing a new research based assessment (RBA) focused on quantitative reasoning -- rather than conceptual understanding -- in physics contexts. We rapidly moved administration of the RBA online in Spring 2020 due to the COVID-19 pandemic. We present our experiences with online, unproctored administration of an RBA in development to students enrolled in a large-enrollment, calculus-based, introductory physics course. We describe our attempts to adhere to best practices on a limited time frame, and present a preliminary analysis of the results, comparing results from the online administration to earlier results from in-person, proctored administration. We include discussion of online administration of multiple-choice/multiple-response (MCMR) items, which we use on the instrument as a way to probe multiple facets of student reasoning. Our initial comparison indicates little difference between online and paper administrations of the RBA, consistent with previous work by other researchers.Comment: PERC 202

Exploring student facility with "goes like'' reasoning in introductory physics

Covariational reasoning -- reasoning about how changes in one quantity relate to changes in another quantity -- has been examined extensively in mathematics education research. Little research has been done, however, on covariational reasoning in introductory physics contexts. We explore one aspect of covariational reasoning: ``goes like'' reasoning. ``Goes like'' reasoning refers to ways physicists relate two quantities through a simplified function. For example, physicists often say that ``the electric field goes like one over r squared.'' While this reasoning mode is used regularly by physicists and physics instructors, how students make sense of and use it remains unclear. We present evidence from reasoning inventory items which indicate that many students are sense making with tools from prior math instruction, that could be developed into expert ``goes like'' thinking with direct instruction. Recommendations for further work in characterizing student sense making as a foundation for future development of instruction are made.Comment: under review for Physics Education Research Conference Proceedings 202

Toward a valid instrument for measuring physics quantitative literacy

We have developed the Physics Inventory of Quantitative Literacy (PIQL) as a tool to measure students' quantitative literacy in the context of introductory physics topics. We present the results from various quantitative analyses used to establish the validity of both the individual items and the PIQL as a whole. We show how examining the results from classical test theory analyses, factor analysis, and item response curves informed decisions regarding the inclusion, removal, or modification of items. We also discuss how the choice to include multiple-choice/multiple-response items has informed both our choices for analyses and the interpretations of their results. We are confident that the most recent version of the PIQL is a valid and reliable instrument for measuring students' physics quantitative literacy in calculus-based introductory physics courses at our primary research site. More data are needed to establish its validity for use at other institutions and in other courses.Comment: accepted for publication: 2020 Physics Education Research Conferenc