It takes a village to raise a teacher: the Learning Assistant programme in Sierra Leone

This is a report on research funded by Plan International on the impact of Learning Assistant (LA) component of Girls Education Challenge Sierra Leone. The LA programme has enabled nearly 500 young women to train as teachers in remote rural areas where schools are understaffed and there are few female teachers. The LA programme provides a pathway to teaching through guided distance study and in-school work experience. This research examines empowering and constraining factors of the LA programme. The research draws on interviews in two rural locations with 18 participants: Learning Assistants themselves, and those who work alongside and support them: headteachers, class teachers, subject tutors, community leaders, family members and programme staff

Precision Vineyard Management: Collecting and Interpreting Spatial Data for Variable Vineyard Management

NYS IPM Type: Project ReportAs the second full year of the Efficient Vineyard SCRI project comes to completion, it is interesting to examine the tools developed, and their use, to move project information into grower vineyards. The most obvious tool is the project website found at https://efficientvineyard.com that provides access to current research articles, bios, interviews and contact information for project participants (broken down by team), general outreach information on the project as well as blog posts, project publications, photos, and general resources found in the dropdown menu under News. Since the start of the project, 12 current research articles and 33 blog posts have been posted. Posts are pushed out on social media (Facebook) to increase the audience for the project https://www.facebook.com/EfficientVineyard-1105411842849154

Spectroscopy and level detuning of few-electron spin states in parallel InAs quantum dots

We use tunneling spectroscopy to study the evolution of few-electron spin states in parallel InAs nanowire double quantum dots (QDs) as a function of level detuning and applied magnetic field. Compared to the much more studied serial configuration, parallel coupling of the QDs to source and drain greatly expands the probing range of excited state transport. Owing to a strong confinement, we can here isolate transport involving only the very first interacting single QD orbital pair. For the (2,0)-(1,1) charge transition, with relevance for spin-based qubits, we investigate the excited (1,1) triplet, and hybridization of the (2,0) and (1,1) singlets. An applied magnetic field splits the (1,1) triplet, and due to spin-orbit induced mixing with the (2,0) singlet, we clearly resolve transport through all triplet states near the avoided singlet-triplet crossings. Transport calculations, based on a simple model with one orbital on each QD, fully replicate the experimental data. Finally, we observe an expected mirrored symmetry between the 1-2 and 2-3 electron transitions resulting from the two-fold spin degeneracy of the orbitals.Comment: 17 pages, 8 figure

Reactive Power Compensation

Reactive power compensation serves to increase the power factor of large industrial loads and increase the efficiency of power transmission. In doing so, reactive power compensation decreases overall energy consumption and has lasting economic and environmental impacts. This paper discusses a simulation to model power consumption in a multitude of different loads, which gives industrial consumers a solution to increase the power factor of their systems to a more desirable level. The MATLAB simulation that we built successfully calculates and displays how much energy can be saved and it shows how that energy can be saved. If physical implementations of our simulation are adopted on a large scale, the economic and environmental impact will be substantial

Electron-hole interactions in coupled InAs-GaSb quantum dots based on nanowire crystal phase templates

We report growth and characterization of a coupled quantum dot structure that utilizes nanowire templates for selective epitaxy of radial heterostructures. The starting point is a zinc blende InAs nanowire with thin segments of wurtzite structure. These segments have dual roles: they act as tunnel barriers for electron transport in the InAs core, and they also locally suppress growth of a GaSb shell, resulting in coaxial InAs-GaSb quantum dots with integrated electrical probes. The parallel quantum dot structure hosts spatially separated electrons and holes that interact due to the type-II broken gap of InAs-GaSb heterojunctions. The Coulomb blockade in the electron and hole transport is studied, and periodic interactions of electrons and holes are observed and can be reproduced by modeling. Distorted Coulomb diamonds indicate voltage-induced ground-state transitions, possibly a result of changes in the spatial distribution of holes in the thin GaSb shell.Comment: 8 pages, 7 figure

Single-electron transport in InAs nanowire quantum dots formed by crystal phase engineering

We report electrical characterization of quantum dots formed by introducing pairs of thin wurtzite (WZ) segments in zinc blende (ZB) InAs nanowires. Regular Coulomb oscillations are observed over a wide gate voltage span, indicating that WZ segments create significant barriers for electron transport. We find a direct correlation of transport properties with quantum dot length and corresponding growth time of the enclosed ZB segment. The correlation is made possible by using a method to extract lengths of nanowire crystal phase segments directly from scanning electron microscopy images, and with support from transmission electron microscope images of typical nanowires. From experiments on controlled filling of nearly empty dots with electrons, up to the point where Coulomb oscillations can no longer be resolved, we estimate a lower bound for the ZB-WZ conduction-band offset of 95 meV.Comment: 9 pages 9 figure

Integrated Arrays of Ion-Sensitive Electrodes

The figure depicts an example of proposed compact water-quality sensors that would contain integrated arrays of ion-sensitive electrodes (ISEs). These sensors would serve as electronic "tongues": they would be placed in contact with water and used to "taste" selected dissolved ions (that is, they would be used to measure the concentrations of the ions). The selected ions could be any or all of a variety of organic and inorganic cations and anions that could be regarded as contaminants or analytes, depending on the specific application. In addition, some of the ISEs could be made sensitive to some neutral analyte