Qualitative Measures of Equity in Small Groups

We investigate the utility of two qualitative measures of equity. Our data are videos of groups of first-generation and Deaf or hard-of-hearing students in a pre-matriculation university program designed to help them persist in STEM fields by developing their metacognitive practices. We analyze video data of students in small groups trying to accomplish various tasks. We analyze how groups engage with proposed ideas (inchargeness) and create a space of open sharing (civility). By capturing different aspects of each group, these measures combine to help our understanding of what an equitable group could look like.Comment: Accepted to International Conference of the Learning Sciences (ICLS) 201

Fostering Physics Content and Pedagogy Learning by Future Physics Teachers via Student Authored YouTube Video Projects

We describe a curricular innovation for STEM teacher preparation -- the use of video projects in undergraduate and graduate physics courses for future physics teachers at SUNY Buffalo State. US courses were adapted under the guidance of our colleagues’ similar work at Universität zu Köln [1]. Our students prepared end of course short “proof of concept” rough video vignettes of 5-10min addressing both physics content and physics pedagogical topics. YouTube [2] example videos are provided, and insights are shared

Adding Student Video Projects to Physics Courses

Physics students have traditionally prepared many kinds of reports—laboratory, activity, project, and even book or article reports. Smartphones and YouTube videos are familiar cultural objects to current students, and our students use smartphone cameras to include photographs of apparatus, phenomena, hand-sketched figures, graphs, and mathematical equations in their physics reports. Here we present basic techniques for physics students to use smartphones and tablets to create short (\u3c 5 min) end-of-semester video projects. Our students mainly use Apple Computer’s iPad1 tablets, but also other tablets and various smartphones. Finally we discuss appropriate instructor expectations and grading. Similar non-physics student video reporting efforts were reported using video cameras by Kearney,2 and Hechter and Guy.

Operando Laboratory-Based Multi-Edge X-Ray Absorption Near-Edge Spectroscopy of Solid Catalysts

Laboratory-based X-ray absorption spectroscopy (XAS) and especially X-ray absorption near-edge structure (XANES) offers new opportunities in catalyst characterization and presents not only an alternative, but also a complementary approach to precious beamtime at synchrotron facilities. We successfully designed a laboratory-based setup for performing operando , quasi-simultaneous XANES analysis at multiple K edges, more specifically, operando XANES of mono-, bi-, and trimetallic CO 2 hydrogenation catalysts containing Ni, Fe, and Cu. Detailed operando XANES studies of the multi-element solid catalysts revealed metal-dependent differences in the reducibility and re-oxidation behavior and their influence on the catalytic performance in CO 2 hydrogenation. The applicability of operando laboratory-based XANES at multiple K edges paves the way for advanced multi-element catalyst characterization complementing detailed studies at synchrotron facilities.Peer reviewe

Adding Student Video Projects to Physics Courses

Physics students have traditionally prepared many kinds of reports—laboratory, activity, project, and even book or article reports. Smartphones and YouTube videos are familiar cultural objects to current students, and our students use smartphone cameras to include photographs of apparatus, phenomena, hand-sketched figures, graphs, and mathematical equations in their physics reports. Here we present basic techniques for physics students to use smartphones and tablets to create short (\u3c 5 min) end-of-semester video projects. Our students mainly use Apple Computer’s iPad1 tablets, but also other tablets and various smartphones. Finally we discuss appropriate instructor expectations and grading. Similar non-physics student video reporting efforts were reported using video cameras by Kearney,2 and Hechter and Guy.

Operando Laboratory-based Multi-edge X-ray Absorption Near-Edge Spectroscopy of Solid Catalysts

Laboratory-based X-ray absorption spectroscopy (XAS) and especially X-ray absorption near-edge structure (XANES) offers new opportunities in catalyst characterization and presents not only an alternative, but also a complementary approach to precious beamtime at synchrotron facilities. We successfully designed a laboratory-based setup for performing operando , quasi-simultaneous XANES analysis at multiple K edges, more specifically, operando XANES of mono-, bi-, and trimetallic CO 2 hydrogenation catalysts containing Ni, Fe, and Cu. Detailed operando XANES studies of the multi-element solid catalysts revealed metal-dependent differences in the reducibility and re-oxidation behavior and their influence on the catalytic performance in CO 2 hydrogenation. The applicability of operando laboratory-based XANES at multiple K edges paves the way for advanced multi-element catalyst characterization complementing detailed studies at synchrotron facilities

Atomic resolution of-axis electron holography with two biprisms

Die Off-Axis-Elektronenholographie zählt zu den am Weitesten verbreiteten holographischen Untersuchungsmethoden im Transmissionselektronenmikroskop. Entscheidende Neuerungen dieser Analysemethode, wie beispielsweise die Optimierung der Biprismaposition, die Vermeidbarkeit von biprismainduzierten Artefakten im Setup mit zwei Biprismen in Abhängigkeit des Biprismaschattens sowie die Möglichkeit, Multiinterferenzhologramme zu erzeugen und zu rekonstruieren, wurden betrachtet und die sich neu ergebenden Potentiale und Optimierungsmöglichkeiten insbesondere für atomare Auflösung abgeschätzt. Bei der Optimierung der Position eines Biprismas für atomar auflösende Elektronenholographie wird der Ablenkwinkel des Elektronenstrahls am Biprisma minimiert. Es ergab sich beispielsweise im Vergleich zum konventionellen Biprismasetup für einen Hologrammstreifenabstand von 100 pm eine direkt gemessene Kontrastverbesserung um den Faktor 1,5. Für das 2-Biprismen-Setup konnte ein formaler Zusammenhang zur Beschreibung der Kontrastdämpfung durch die Modulationstransferfunktion der Kamera, der partiellen räumlichen Kohärenz und der Biprismavibration analytisch abgeleitet werden. Damit konnte die Standardabweichung der Position des ersten Biprismas auf etwa 16 pm, bezogen auf die Objektebene, bestimmt werden, wenn man eine gauÿartige Vibration des Biprismas annimmt. Für einen Streifenabstand von 30 pm ergibt sich eine um den Faktor 1,25 verbesserte Kontrastdämpfung für die optimale Kombination der Biprismaspannun- gen im Vergleich zu einem Setup mit nur einem Biprisma. Werden die Biprismen nicht parallel, sondern senkrecht zueinander angeordnet, lassen sich Mulitiinterferenzhologramme eines Objekts anfertigen. Es konnte anhand von Simulation und Experiment gezeigt werden, dass dieses Vorgehen prinzipiell auch in der Elektronenholographie möglich ist, allerdings ist für die fehlerfreie Rekonstruktion der Bildwellen eine annähernd verzeichungsfreie Aufnahme erforderlich. Das optimierte Setup mit zwei Biprismen ist von Instabilitäten insgesamt geringer betroffen, was anhand von Hologrammen von Gold und Galliumnitrid gezeigt wurde. Die rekonstruierte und um Abbildungsfehler bereinigten Amplitude und Phase zeigen hervorragende quantitative Übereinstimmung zur Simulationen eines Galliumnitridkristalls.Off-axis electron holography is one of the most powerful holographic investigation methods within the transmission electron microscope. Several improvements of this investigation method, e.g., the optimization of the biprism position, the possibility to reduce biprism induced artefacts strongly with a double biprism setup, or the generation of multiinterference holograms, and their new possibilities were investigated, especially for atomic resolution. For the optimization of the biprism position for atomic resolution electron holograms, the deflection angle of the electron beam at the biprism is reduced. In comparison to the conventional setup, for a fringe spacing of 100 pm a contrast improvement of a factor of about 1.5 was observed in the optimized setup. In the double biprism setup the contrast damping by the modulation transfer function of the camera, by partial spatial coherence, and by biprism vibration leads to the optimum biprism voltage ratio with the lowest overall damping. Within this estimation the biprism vibration was investigated. A standard deviation of about 16 pm of the biprism position, relative to the object plane, was observed, assuming a gaussian distribution of the biprism position. For a fringe spacing of 30 pm, the contrast damping is improved by factor of about 1.25 in comparison to a setup with just one biprism. If the biprisms are positioned approximately perpendicular to each other, the aquisition of multiinterference holograms is possible. With simulation and experiment it was shown, that this is also possible in electron holography, but for the correct reconstruction of the image wave a hologram without almost any distortions is necessary. The optimized setup with two biprisms is less affected by instabilities. This was demonstrated using thin gold and gallium nitride crystals. Residual aberrations in the reconstructed amplitude and phase were removed numerically. The results show a very good quantitative match to the corresponding simulations

How Do Workers Adjust When Firms Adopt New Technologies?

We investigate how workers adjust to firms’ investments into new digital technologies, including artificial intelligence, augmented reality, or 3D printing. For this, we collected novel data that links survey information on firms’ technology adoption to administrative social security data. We then compare individual outcomes between workers employed at technology adopters relative to non-adopters. Depending on the type of technology, we find evidence for improved employment stability, higher wage growth, and increased cumulative earnings in response to digital technology adoption. These beneficial adjustments seem to be driven by technologies used by service providers rather than manufacturers. However, the adjustments do not occur equally across worker groups: IT-related expert jobs with non-routine analytic tasks benefit most from technological upgrading, coinciding with highly complex job requirements, but not necessarily with more academic skills