Realization of the farad from the dc quantum Hall effect with digitally-assisted impedance bridges

A new traceability chain for the derivation of the farad from dc quantum Hall effect has been implemented at INRIM. Main components of the chain are two new coaxial transformer bridges: a resistance ratio bridge, and a quadrature bridge, both operating at 1541 Hz. The bridges are energized and controlled with a polyphase direct-digital-synthesizer, which permits to achieve both main and auxiliary equilibria in an automated way; the bridges and do not include any variable inductive divider or variable impedance box. The relative uncertainty in the realization of the farad, at the level of 1000 pF, is estimated to be 64E-9. A first verification of the realization is given by a comparison with the maintained national capacitance standard, where an agreement between measurements within their relative combined uncertainty of 420E-9 is obtained.Comment: 15 pages, 11 figures, 3 table

Regenerative agriculture in Aotearoa New Zealand - research pathways to build science-based evidence and national narratives.

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Mapping and monitoring geological hazards using optical, LiDAR, and synthetic aperture RADAR image data

Geological hazards and their effects are often geographically widespread. Consequently, their effective mapping and monitoring is best conducted using satellite and airborne imaging platforms to obtain broad scale, synoptic coverage. With a multitude of hazards and effects, potential data types, and processing techniques, it can be challenging to determine the best approach for mapping and monitoring. It is therefore critical to understand the spatial and temporal effects of any particular hazard on the environment before selecting the most appropriate data type/s and processing techniques to apply. This review is designed to assist the decision-making and selection process when embarking on a hazard mapping or monitoring exercise. It focuses on the application of optical, LiDAR, and synthetic aperture RADAR technologies for the assessment of pre-event risk and post-event damage. Geological hazards of global interest summarized here are landslides and erosion; seismic and tectonic hazards; ground subsidence; and flooding and tsunami

Community involvement and the Commonside Community Development Trust.

The Commonside Trust is a non-profit community organization devoted to developing the Commonside area, located in the London borough of Merton. Because of limited staff, the Trust has been unable to devote resources to increase its volunteer base and community awareness of its programs. The purpose of this study was (1) to gather and present information to the Trust about attitudes towards volunteering, and (2) to provide technical support (a website review and a database) that will aid their efforts to increase volunteers and community involvement

WPI AIAA Research Rocket (WARRIORS)

WARRIORS was a two-stage, high-powered rocket equipped with a computer and video camera. The goal of WARRIORS was to challenge students to develop innovative rocket staging and recovery techniques. The project was a joint effort between eight MQP students and AIAA WPI chapter student volunteers. This paper describes the design, testing, operation, and results from the creation and implementation of an innovative electromagnetic booster-separation system, non-pyrotechnic parachute deployment mechanisms, an ignition system that prevents asymmetric thrust, and a custom-constructed airframe