Unpacking paradise: geography education narratives from the Seychelles

The hybrid legacy of an English-based curriculum and socialist education principals, fused with contemporary aspirations to be a ‘knowledge-based society’, mean Seychelles’ model of education presents a peculiar, paradoxical mélange. The small island nation is inextricably linked to England’s farreaching ‘educational space', yet while this connection enhances the legitimacy of its educational achievements, local governance is compromised. To understand the nature and scope of this compromise, the forces influencing education in Seychelles are explored through one area of the curriculum: geography education. The research draws on teachers’ narratives to investigate the extent to which geography education is framed by a (neo)colonial geographical imagination. The narratives, co-constructed from stories of classroom practice, make meaning from the everyday and the 'taken-for-granted' lives of geography teachers in Seychelles. Close and trusted relationships had to be developed so teachers felt comfortable sharing their stories. Given the intimacies involved, an intriguing set of ethical and methodological challenges were encountered. Through the linking of personal stories of geography curriculum making to public narratives of geography education, and to wider social, cultural and historical events, the intricacies of teaching geography in a small and relatively isolated professional community were revealed. The politics of language, culture and power created unease in geography classrooms, yet this disquiet did not resonate with teachers’ proud sense of Kreolité. Also, while some teachers felt marginalized from geography curriculum conversations, others were keen to engage in ‘subversive’ dialogue in order to challenge the curriculum status quo and develop a greater sense of professional self-worth. As an example of the use of storytelling to support teachers’ professional development, the inquiry also provides an innovative contribution to understanding the way powerful discourses and the dialectic realities of globalisation not only shape geography teachers lives, but also destabilise vulnerable SIDS’ education systems

Processing Issues in Top-Down Approaches to Quantum Computer Development in Silicon

We describe critical processing issues in our development of single atom devices for solid-state quantum information processing. Integration of single 31P atoms with control gates and single electron transistor (SET) readout structures is addressed in a silicon-based approach. Results on electrical activation of low energy (15 keV) P implants in silicon show a strong dose effect on the electrical activation fractions. We identify dopant segregation to the SiO2/Si interface during rapid thermal annealing as a dopant loss channel and discuss measures of minimizing it. Silicon nanowire SET pairs with nanowire width of 10 to 20 nm are formed by electron beam lithography in SOI. We present first results from Coulomb blockade experiments and discuss issues of control gate integration for sub-40nm gate pitch levels

Electrical activation and electron spin coherence of ultra low dose antimony implants in silicon

We implanted ultra low doses (2x10^11 cm-2) of 121Sb ions into isotopically enriched 28Si and find high degrees of electrical activation and low levels of dopant diffusion after rapid thermal annealing. Pulsed Electron Spin Resonance shows that spin echo decay is sensitive to the dopant depths, and the interface quality. At 5.2 K, a spin decoherence time, T2, of 0.3 ms is found for profiles peaking 50 nm below a Si/SiO2 interface, increasing to 0.75 ms when the surface is passivated with hydrogen. These measurements provide benchmark data for the development of devices in which quantum information is encoded in donor electron spins

Drift compensation of gas sensor array data by Orthogonal Signal Correction

Drift is an important issue that impairs the reliability of gas sensing systems. Sensor aging, memory effects and environmental disturbances produce shifts in sensor responses that make initial statistical models for gas or odor recognition useless after a relatively short period (typically few weeks). Frequent recalibrations are needed to preserve system accuracy. However, when recalibrations involve numerous samples they become expensive and laborious. An interesting and lower cost alternative is drift counteraction by signal processing techniques. Orthogonal Signal Correction (OSC) is proposed for drift compensation in chemical sensor arrays. The performance of OSC is also compared with Component Correction (CC). A simple classification algorithm has been employed for assessing the performance of the algorithms on a dataset composed by measurements of three analytes using an array of seventeen conductive polymer gas sensors over a ten month period

Short-Pulse, Compressed Ion Beams at the Neutralized Drift Compression Experiment

We have commenced experiments with intense short pulses of ion beams on the Neutralized Drift Compression Experiment (NDCX-II) at Lawrence Berkeley National Laboratory, with 1-mm beam spot size within 2.5 ns full-width at half maximum. The ion kinetic energy is 1.2 MeV. To enable the short pulse duration and mm-scale focal spot radius, the beam is neutralized in a 1.5-meter-long drift compression section following the last accelerator cell. A short-focal-length solenoid focuses the beam in the presence of the volumetric plasma that is near the target. In the accelerator, the line-charge density increases due to the velocity ramp imparted on the beam bunch. The scientific topics to be explored are warm dense matter, the dynamics of radiation damage in materials, and intense beam and beam-plasma physics including select topics of relevance to the development of heavy-ion drivers for inertial fusion energy. Below the transition to melting, the short beam pulses offer an opportunity to study the multi-scale dynamics of radiation-induced damage in materials with pump-probe experiments, and to stabilize novel metastable phases of materials when short-pulse heating is followed by rapid quenching. First experiments used a lithium ion source; a new plasma-based helium ion source shows much greater charge delivered to the target.Comment: 4 pages, 2 figures, 1 table. Submitted to the proceedings for the Ninth International Conference on Inertial Fusion Sciences and Applications, IFSA 201

MICROGRAVITY AND ITS BEARING WITH SPACE FLIGHT-RELATED RESEARCH

This study investigates the unique properties and applications of microgravity in the context of spaceflight research. Understanding and harnessing the behaviors of a microgravity environment opens up the doors to long-term space travel and consequently, future missions to other planets within our solar system. More specifically, simulating and conducting experiments in microgravity environments helps us explore its effects on the various necessary tasks and behaviors that are carried out during spaceflight. The most immediate and pronounced effects of microgravity are on human physiology. In particular, studies have shown that prolonged exposure to microgravity can result in a 20% decrease in muscle mass and a 5% decrease in bone mineral density. As research on these effects continue, astronauts will be better equipped to battle these unusual conditions in order to maintain a healthy and able body during spaceflight. In addition to its effects on the human body, microgravity environments provide promising ways to manufacture materials that would otherwise be too costly or difficult to create on Earth. Manufacturing materials of incredible strength and developing cables that can transmit information at unprecedented speeds are made possible in a microgravity environment. Not only does this paper summarize the currently known effects of microgravity, but it also explores the direct applications of microgravity research in past, present, and future space missions

SEDIMENTOLOGY OF THE UPPER SCOTLAND FORMATION (EOCENE), BARBADOS

Representative samples collected from the Lower Scotland Formation (Eocene) outcropping in northeastern Barbados were investigated in conjunction with overall facies distribution and stratigraphic and sedimentological characteristics to interpret depositional environment and provenance of the fine-grained clastics. The Lower Scotland Formation is, for the most part, a fine-grained clastic-dominated sequence with occasional thin intercalations of gypsum, ironstone, and kaolinite. Distinctive deep-water-facies have been well-documented in dark gray shale units containing load cast, flutes, grooves and prods. In addition, turbiditic brown sandstone with a sharp erosive base and pelagic caps also characterize the base of the formation. Notable marine fauna observed include Nummulites, Orbitoids, and occasionally Discocyclina sp. The Lower Scotland Formation has been intensely folded and faulted and, in many places, shows a thrust contact with the Upper Scotland Formation. Preliminary compositional studies involved both light and heavy mineral separation, as well as thin section studies. Detrital minerals in the formation include quartz (both monocrystalline and polycrystalline), feldspar (mostly altered microcline), and altered biotite. Heavy minerals include zircon, monazite, tourmaline, rutile, kyanite, and augite. Lithic fragment of varied source rocks are also observed. Bulk chemical and trace element investigation of the selected samples suggests an overall trend of immobile traces including Sr, Ba, and Rb increasing up-section and an overall decreasing silica content up-section. The Northwestern Venezuelan Shield, located to the south of the study area, acted as the primary source of detritus for the Lower Scotland Formation, the latter being subjected to pronounced structural deformation in response to the Cenozoic Andean Orogenic episode

Fast Grain Mapping with Sub-Nanometer Resolution Using 4D-STEM with Grain Classification by Principal Component Analysis and Non-Negative Matrix Factorization

High-throughput grain mapping with sub-nanometer spatial resolution is demonstrated using scanning nanobeam electron diffraction (also known as 4D scanning transmission electron microscopy, or 4D-STEM) combined with high-speed direct electron detection. An electron probe size down to 0.5 nm in diameter is implemented and the sample investigated is a gold-palladium nanoparticle catalyst. Computational analysis of the 4D-STEM data sets is performed using a disk registration algorithm to identify the diffraction peaks followed by feature learning to map the individual grains. Two unsupervised feature learning techniques are compared: Principal component analysis (PCA) and non-negative matrix factorization (NNMF). The characteristics of the PCA versus NNMF output are compared and the potential of the 4D-STEM approach for statistical analysis of grain orientations at high spatial resolution is discussed