Rural Teacher Attitudes and Engagement With Computing and Technology

The purpose of this sequential Case Study-Mixed Methods research is to explore rural teacher attitudes toward, approaches to, and engagement with making and computational thinking during STEM professional development and co-teaching learning experiences. Specifically, we examine the professional learning needs of two rural, middle school teachers as they engage technology. Using the lens of cultural historical activity theory, this paper examines the ways in which teacher attitude about computing shifted throughout professional learning and instructional practice. Findings show three broad themes that emerge surrounding teacher attitudes, approaches, and engagement with technology: Anxiety, Independent Learner, and Integration. Additionally, findings suggest that teacher attitude toward technology can be moderated through the means of a more knowledgeable other who scaffolds teacher learning and integration of technology

Situating Speech: A Rhetorical Approach to Political Strategy

Ideas are increasingly acknowledged as factors in explaining political behaviour. But often they are treated as inert resources rather than dynamic instances of action in themselves. The latter, I propose, requires reflection on the character of speech – as the medium of ideas – in responding to and refiguring a prevailing situation. I undertake such reflection by setting out a rhetorical approach to political strategy. Building upon ‘interpretive’ advances in political science I shift the focus from stable cognitive frames to the dynamics of argumentation where ideas work expressively. I then explore the rhetorical aspect of strategising with attention to the way speech serves to orient audiences by creatively re-appropriating a situation. That approach is shown to be consistent with a ‘dialectical’ political sociology that emphasises the interaction of structure and agency. Finally, I sketch a method for undertaking rhetorical analysis and indicate how it might be applied to a concrete example

Developing cognitive task analysis and the importance of sociocognitive competence/insight for professional practice

Accelerating the cognitive expertise of professionals is a critical challenge for many organizations. This paper reports a collaborative, longitudinal, academic practitioner project which aimed to elicit, document, and accelerate the cognitive expertise of engineering professionals working with the manufacture and management of petroleum additives. Twenty-five engineering experts were trained by three academic psychologists to use applied cognitive task analysis (ACTA) interview techniques to document the cognition of their expert peers. Results had high face validity for practitioners who elicited hot/ sensory-based cognition, a number of perceptual skills and mental models, highlighting undocumented context specific expertise. We conclude from a peer review of findings, combined with experienced CTA analysts that ACTA technique

Ultrasonic spectroscopy of silicon single crystal

Specimens of Si single crystals with different crystal orientation [100] and [110] were studied by Electro-Ultrasonic Spectroscopy (EUS) and Resonant Ultrasonic Spectroscopy (RUS). A silicon single crystal is an anisotropic crystal, so its properties are different in different directions in the material relative to the crystal orientation. EUS is based on interaction of two signals: an electric AC signal and an ultrasonic signal, which are working on different frequencies. The ultrasonic wave affects the charge carriers' transport in the structures and the intermodulation electrical signal which is created due to the interaction between the ultrasonic wave and charge carriers, is proportional to the density of structural defects. RUS enables to measure natural frequencies of free elastic vibrations of a simply shaped specimen by scanning a selected frequency range including the appropriate resonances of the measured specimens

A single-material multi-source energy harvester, multifunctional sensor, and integrated harvester-sensor system-demonstration of concept

Abstract Single‐source energy harvesters that convert solar, thermal, or kinetic energy into electricity for small‐scale smart electronic devices and wireless sensor networks have been under development for decades. When an individual energy source is insufficient for the required electricity generation, multi‐source energy harvesting is indicated. Current technology usually combines different individual harvesters to achieve the capability of harvesting multiple energy sources simultaneously. However, this increases the overall size of the multi‐source harvester, but in microelectronics miniaturization is a critical consideration. Herein, an advanced approach is demonstrated to solve this issue. A single‐material energy harvesting/sensing device is fabricated using a (K0.5Na0.5)NbO3‐Ba(Ni0.5Nb0.5)O3–Δ (KNBNNO) ceramic as the sole energy‐conversion component. This single‐material component is able simultaneously to harvest or sense solar (visible light), thermal (temperature fluctuation), and kinetic (vibration) energy sources by incorporating its photovoltaic, pyroelectric, and piezoelectric effects, respectively. The interactions between different energy conversion effects, e.g., the influence of dynamic behavior on the photovoltaic effect and alternating current–direct current (AC–DC) signal trade‐offs, are assessed and discussed. This research is expected to stimulate energy‐efficient design of electronic devices by integrating both harvesting and sensing functions in the same material/component

Nonlinear piezoelectric devices for broadband air-flow energy harvesting

This paper presents preliminary work on an investigation of a nonlinear air-flow energy harvester integrating magnets and a piezoelectric cantilever array. Two individual piezoelectric cantilevers with the structure of free-standing multi-layer thick-films have been fabricated and assembled with a free-spinning fan. The cantilevers were attached with different tip masses thereby achieving separated resonant frequencies. Also, permanent magnets were fixed onto the blades of the fan as well as the tips of the cantilevers, in order to create nonlinear coupling and transfer fluidic movement into mechanical oscillation. The device has been tested in a wind tunnel. Bifurcations in the spectra of the blade rotation speed of the fan as a function of output voltage have been observed, and a bandwidth (blade rotation speed range) widening effect has been achieved

A game changer:a multifunctional perovskite exhibiting giant ferroelectricity and narrow bandgap with potential application in a truly monolithic multienergy harvester or sensor

Abstract An ABO3-type perovskite solid-solution, (K₀.₅Na₀.₅)NbO₃ (KNN) doped with 2 mol% Ba(Ni₀.₅Nb₀.₅)O₃−δ (BNNO) is reported. Such a composition yields a much narrower bandgap (≈1.6 eV) compared to the parental composition—pure KNN—and other widely used piezoelectric and pyroelectric materials (e.g., Pb(Zr,Ti)O₃, BaTiO₃). Meanwhile, it exhibits the same large piezoelectric coefficient as that of KNN (≈100 pC N⁻¹) and a much larger pyroelectric coefficient (≈130 µC m⁻² K⁻¹) compared to the previously reported narrow-bandgap material (KNbO₃)₁₋ₓ-BNNOₓ. The unique combination of these excellent ferroelectric and optical properties opens the door to the development of multisource energy harvesting or multifunctional sensing devices for the simultaneous and efficient conversion of solar, thermal, and kinetic energies into electricity in a single material. Individual and comprehensive characterizations of the optical, ferroelectric, piezoelectric, pyroelectric, and photovoltaic properties are investigated with single and coexisting energy sources. No degrading interaction between ferroelectric and photovoltaic behaviors is observed. This composition may fundamentally change the working principles of state-of-the-art hybrid energy harvesters and sensors, and thus significantly increases the unit-volume energy conversion efficiency and reliability of energy harvesters in ambient environments

Investigation of a cantilever structured piezoelectric energy harvester used for wearable devices with random vibration input

Abstract The capability of using a linear kinetic energy harvester — A cantilever structured piezoelectric energy harvester — to harvest human motions in the real-life activities is investigated. The whole loop of the design, simulation, fabrication and test of the energy harvester is presented. With the smart wristband/watch sized energy harvester, a root mean square of the output power of 50 μW is obtained from the real-life hand-arm motion in human’s daily life. Such a power is enough to make some low power consumption sensors to be self-powered. This paper provides a good and reliable comparison to those with nonlinear structures. It also helps the designers to consider whether to choose a nonlinear structure or not in a particular energy harvester based on different application scenarios