Business Critical: Understanding a Company’s Current and Desired Stages of Corporate Responsibility Maturity

It’s been a while since the Corporate Responsibility profession took stock of its collective wisdom on where we have been, and where we are going on running businesses responsibly. Meanwhile hardly a week goes by without a helpful suggestion from the outside world on how an organisation should improve its economic value, social usefulness and environmental efficiency; and it is very easy to spot businesses that get their social, environmental and economic decisions out of balance: these organisations hit the headlines seemingly within nanoseconds. On the upside, businesses are increasingly taking an approach that builds an Environmental, Social and Governance (ESG) premium into the core economic valuation. This is achieved by those organisations which bring in a diverse set of views to inform risk and reputation management activities, and to build a research and development pipeline for the future. This is managing both the negative and the positive social, environmental and economic impacts

Probing the Electrostatics of Integer Quantum Hall Edges with Momentum-Resolved Tunnel Spectroscopy

We present measurements of momentum-resolved magneto-tunneling from a perpendicular two-dimensional (2D) contact into integer quantum Hall (QH) edges at a sharp edge potential created by cleaved edge overgrowth. Resonances in the tunnel conductance correspond to coincidences of electronic states of the QH edge and the 2D contact in energy-momentum space. With this dispersion relation reflecting the potential distribution at the edge we can directly measure the band bending at our cleaved edge under the influence of an external voltage bias. At finite bias we observe significant deviations from the flat-band condition in agreement with self-consistent calculations of the edge potential

The national in the network society: UKUncut, the English Defence League and the challenge for social democracy

This chapter argues that the European crisis in social democracy is partially to do with a failure to engage publics at the level of the national. It looks at how two groups in the UK, one broadly left and the other far-right, have used social media to engage with the discourse of nation in the construction of identity networks to further their political goals. The argument is that social democratic parties need to learn from these groups if they are to continue to be a force in European politics

Novel metallic and insulating states at a bent quantum Hall junction

A non-planar geometry for the quantum Hall (QH) effect is studied, whereby two quantum Hall (QH) systems are joined at a sharp right angle. When both facets are at equal filling factor nu the junction hosts a channel with non-quantized conductance, dependent on nu. The state is metallic at nu = 1/3, with conductance along the junction increasing as the temperature T drops. At nu = 1, 2 it is strongly insulating, and at nu = 3, 4 shows only weak T dependence. Upon applying a dc voltage bias along the junction, the differential conductance again shows three different behaviors. Hartree calculations of the dispersion at the junction illustrate possible explanations, and differences from planar QH structures are highlighted.Comment: 5 pages, 4 figures, text + figs revised for clarit

Initial Public Offerings of Ballplayers

As a field study of choice under uncertainty, we examine baseball teams' investments in amateur players. Though most prospects fail to deliver any return on their multi-million dollar signing bonuses, returns on the minority who succeed easily offset these losses: the expected annual yield on the median first-round draftee is 33 percent. However, the pattern of returns is inconsistent with market efficiency. Yields are lower for high schoolers than collegians (27 percent vs. 43 percent), lower for pitchers than position players (24 percent vs. 41 percent), decline for later round long-shots, and may be negative under competitive bidding.Market efficiency; Bounded rationality; Prospect theory; Winner’s curse

Variable-gravity anti-vortex and vapor-ingestion-suppression device

A liquid propellant management device for placement in a liquid storage tank adjacent an outlet of the storage tank to substantially reduce or eliminate the formation of a dip and vortex in the liquid of the tank, as well as prevent vapor ingestion into the outlet, as the liquid drains out through the outlet. The liquid propellant management device has a first member adapted to suppress the formation of a vortex of a liquid exiting the storage tank. A plate is affixed generally perpendicular to the first member, wherein the plate is adapted to suppress vapor ingestion into the outlet by reducing a dip in a surface level of the liquid leaving the tank. A second member is affixed to the second side of the plate. The second member ensures that the plate is wet with liquid and assists in positioning bubbles away from the outlet

Corner overgrowth: Bending a high mobility two-dimensional electron system by 90 degrees

Introducing an epitaxial growth technique called corner overgrowth, we fabricate a quantum confinement structure consisting of a high-mobility GaAs/AlGaAs heterojunction overgrown on top of an ex-situ cleaved substrate corner. The resulting corner-junction quantum-well heterostructure effectively bends a two-dimensional electron system (2DES) at an atomically sharp $90^{\rm o}$ angle. The high-mobility 2DES demonstrates fractional quantum Hall effect on both facets. Lossless edge-channel conduction over the corner confirms a continuum of 2D electrons across the junction, consistent with Schroedinger-Poisson calculations of the electron distribution. This growth technique differs distinctly from cleaved-edge overgrowth and enables a complementary class of new embedded quantum heterostructures.Comment: 3 pages, 4 figures, latest version accepted to AP

Advancements in Microscale Tensile Testing: A Novel Device for the High Throughput Analysis of Two-photon Polymerized Microfibers in Liquid

Two-photon polymerization (TPP) enables the 3D fabrication of micro- and nanostructures from biocompatible materials with high resolutions, reaching into the realm of hundreds of nanometers. Such capabilities are crucial for advancing applications in fields like mechanobiology. As microscale technologies evolve, the precise characterization of material properties becomes increasingly essential. This is especially true for TPP-printed microstructures serving as scaffolds for 3D cell culture and intended for studying the mechanics of tissues. Despite the importance, traditional micro-scale tensile testing methods typically lack scalability and fail to replicate relevant environmental conditions. This dissertation introduces a new device that is specifically designed to enhance throughput and that enables tensile testing of microfibers within liquid environments. This microscale tensile testing device not only enhances testing capabilities but also provides unique insights into material behaviors, unlocking new possibilities for understanding and manipulating micro- and nano-scale materials. Central to this research is an extensive exploration of the physical and chemical processes underlying TPP. By examining various processing parameters and their effects on mechanical properties, this study elucidates how TPP can be optimized for enhanced performance. The results demonstrate that the new device not only significantly improves the efficiency of microscale mechanical testing but also enables precise evaluation of the fabrication process. This advancement establishes a new benchmark for evaluating microscale materials, crucial for advancing fields such as tissue engineering and regenerative medicine. These advancements also contribute significantly to the field of materials testing by providing a robust tool for rapid and detailed assessment of a multitude of photo-resins. Future work will focus on further refining the device’s capabilities, including standardization and automation, and exploring its applications in broader industrial settings. Advisor: Ruiguo Yan

Vertical quantum wire realized with double cleaved-edge overgrowth

A quantum wire is fabricated on (001)-GaAs at the intersection of two overgrown cleaves. The wire is contacted at each end to n+ GaAs layers via two-dimensional (2D) leads. A sidegate controls the density of the wire revealing conductance quantization. The step height is strongly reduced from 2e^2/h due to the 2D-lead series resistance. We characterize the 2D density and mobility for both cleave facets with four-point measurements. The density on the first facet is modulated by the substrate potential, depleting a 2um wide strip that defines the wire length. Micro-photoluminescence shows an extra peak consistent with 1D electron states at the corner.Comment: 4 pages, 4 figure

A Holistic Professional Development model for South African physical science teachers

The state of mathematics and science education in South Africa is a cause for concern. This situation can be attributed, in part, to many mathematics and science teachers’ limited content knowledge, ineffective teaching approaches, and unprofessional attitudes. To address these three problem areas simultaneously, a holistic model for the development of Grades 10 to 12 Physical Science teachers was constructed and evaluated against national and international benchmarks. The effects of the model were assessed over a period of four years with 75 teachers. The model was developed in a distance education context, with no face-to-face contact required. It comprises the following elements: a study guide which integrates the development of teachers’ content knowledge, pedagogical content knowledge, cognitive skills and experimental skills; reflective journals; assignments; workshops; peer support and sciencekits. We briefly describe the research that culminated in the Holistic ProfessionalDevelopment (HPD) model, followed by an account of each element of the model. We then present evidence that suggests that the model is effective in helping teachers develop along three desired dimensions, namely, content knowledge, teaching approaches, and professional attitudes