Transitional edges: a conceptual framework for socio-spatial understanding of urban street edges

This paper develops a conceptual framework of transitional edges to enhance understanding of the social value of urban street edges. Building from theoretical principles associated with socio-spatial understandings of urban realms, transitional edges conceptualise urban street edges as integrations of their social, spatial and material dimensions. This is captured in a tripartite structure highlighting socially relevant properties of transitional edges that act along them (extent), across them (laterality) and within them (locality). This provides a foundation for developing an approach to practical application based on identification and evaluation of transitional edges as assemblages of territorialised segments. To progress this, a developmental study of a length of Sharrow Vale Road in Sheffield, UK was carried out to explore how theoretical principles of the transitional edge conceptual framework could be translated for practical application. This reveals the potential of transitional edges to highlight that locally focused small scale change and adaptation may be significant to the social potential of urban street edges. As a result, the current study sets out theoretical and practical foundations for a conceptual framework of transitional edges which will support development of an extensive funded programme of transitional edge case study research

Effects of a Three-week Core Training Program on Different Unstable Platforms

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Thermally excited tunneling from a metastable electronic state in a single-Cooper-pair transistor

International audienceMetastable electron traps and two-level systems are common in solid-state devices and lead to background charge movement and charge noise in single-electron and singleCooper-pair transistors. We present measurements of the real-time capture and escape of individual electrons in metastable trapped states at very low temperatures, leading to charge offsets close to 1e. The charge movement exhibits thermal excitation to a hysteretic tunneling transition. The temperature dependence and hysteresis can be explained by the coupling of a two-level system to a quasiparticle trap

Thermal excitation of large charge offsets in a single-Cooper-pair transistor

International audienceCharge offsets and two-level fluctuators are common in single-electron transistors (SET) with a typical magnitude |∆Q| < 0.1e. We now present measurements in a 2e-periodic single-Cooper-pair transistor (SCPT) which exhibited hysteretic charge offsets close to 1e. The real-time capture and escape of individual electrons in metastable trapped states was measured at very low temperatures. This enabled the dynamics of the transitions to be investigated in detail, demonstrating thermal excitation to a hysteretic tunneling transition. We also show that, allowing for the hysteresis, the metastable states are in thermal equilibrium with each other. The observed temperature dependence and hysteresis can be explained by the coupling of a two-level fluctuator to a quasiparticle trap

Nitrogen for Minnesota Soils

This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu

In-Class Versus At-Home Quizzes: Which is Better? A Flipped Learning Study in a Two-Site Synchronously-Broadcast Organic Chemistry Course

We recently shared our design of a two-semester flipped organic chemistry course, in which we gave students in-class quizzes to incentivize attendance and watching the lecture videos in advance. With a second iteration, we planned to make the video-watching experience more engaging. We accordingly hypothesized that if students completed short at-home quizzes while watching the videos, then attentiveness, engagement, and learning would increase. We tested this with a later section of the course, dividing the material into 13 units. For units 1-6, we gave in-class quizzes; for 7-13, quizzes were at home. Although units 1-6 and 7-13 covered different material, we were nonetheless surprised when students’ average quiz scores decreased for the take-home quizzes, because they did not have a time limit and were open-book, unlike the in-class quizzes. Anonymous survey feedback showed a strong preference for quizzes in class and indications that take-home quizzes demotivated attendance and pre-class watching of the videos. Thus, for analogous flipped course designs in chemistry, we recommend an in-class quizzing strategy over take-home quizzes to positively affect engagement, learning, and attendance. Of note, this course was synchronously delivered to two groups of students at geographically-distinct satellite locations

On the application of radio frequency voltages to ion traps via helical resonators

Ions confined using a Paul trap require a stable, high voltage and low noise radio frequency (RF) potential. We present a guide for the design and construction of a helical coil resonator for a desired frequency that maximises the quality factor for a set of experimental constraints. We provide an in-depth analysis of the system formed from a shielded helical coil and an ion trap by treating the system as a lumped element model. This allows us to predict the resonant frequency and quality factor in terms of the physical parameters of the resonator and the properties of the ion trap. We also compare theoretical predictions with experimental data for different resonators, and predict the voltage applied to the ion trap as a function of the Q-factor, input power and the properties of the resonant circuit

Fertilizer Urea

This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu