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Christchurch, New Zealand

Bennett A.J.,Industrial Research Ltd. | Harrison R.G.,University of Reading
Physical Review Letters | Year: 2013

By combining electrostatic measurements of lightning-induced electrostatic field changes with radio frequency lightning location, some field changes from exceptionally distant lightning events are apparent which are inconsistent with the usual inverse cube of distance. Furthermore, by using two measurement sites, a transition zone can be identified beyond which the electric field response reverses polarity. For these severe lightning events, we infer a horizontally extensive charge sheet above a thunderstorm, consistent with a mesospheric halo of several hundred kilometers' extent. © 2013 American Physical Society. Source


Poletti M.A.,Industrial Research Ltd.
Journal of the Acoustical Society of America | Year: 2010

The cylindrical and spherical harmonic expansions of oscillating sound fields rotating at a constant rate are derived. These expansions are a generalized form of the stationary sound field expansions. The derivations are based on the representation of interior and exterior sound fields using the simple source approach and determination of the simple source solutions with uniform rotation. Numerical simulations of rotating sound fields are presented to verify the theory. © 2010 Acoustical Society of America. Source


Saunders P.,Industrial Research Ltd.
International Journal of Thermophysics | Year: 2011

The size-of-source effect (SSE) is a major contributor to error and uncertainty in both the calibration and use of a radiation thermometer, and correcting for the SSE is necessary to achieve high accuracy. There are several recognized methods for measuring the SSE; each measures a slightly different quantity and may depend on one of various parameters, such as the diameter of the black spot or the maximum aperture diameter. When applying corrections, it is necessary, in principle, to recognize which SSE quantity has been measured and under which conditions, as the correction formulae for each quantity differ and may also be functions of the measurement parameters. In this article, the formulae for each quantity are derived, and it is shown that the differences are only second order, so that for sufficiently small SSE, a single simple approximation can be made, independent of whether the SSE values are close to 1, as in the direct method, or close to 0, as in the indirect method. It is also shown that when measuring the radiance distribution surrounding the target in order to apply SSE corrections for the target, these surrounding measurements, which are also subject to the SSE, do not themselves require corrections, even for the highest level of target temperature accuracy. © 2011 Springer Science+Business Media, LLC. Source


Saunders P.,Industrial Research Ltd.
International Journal of Thermophysics | Year: 2011

Recent advances in high-temperature thermometry have opened up the possibility of realizing and disseminating thermodynamic temperatures above the silver point by means of both primary radiometry and radiation thermometry with the aid of high-temperature fixed points with known thermodynamic temperatures. A variety of realization schemes, denoted n = 0, 1, 2, 3, 3+, where n refers to the number of fixed points used in the realization, are described in new sections of the "Mise en pratique for the definition of the kelvin." A major advantage of this approach is flexibility, accommodating the varying resources and needs of a wide range of laboratories and/or users. This article outlines the uncertainty analysis for each of the n ≥ 0 schemes, which provides a means for assessing the suitability of any particular scheme and for selection of the appropriate fixed points. In all cases, the analysis is based on a modified Sakuma-Hattori model of the radiometer response. This model allows simple analytical expressions to be derived for all sensitivity coefficients, identification of the dominant uncertainty components, and each scheme to be easily compared. Current best estimates for each uncertainty component are given, and these are propagated to give a total uncertainty for each scheme. © 2011 Springer Science+Business Media, LLC. Source


Weston R.J.,Industrial Research Ltd.
Food Chemistry | Year: 2010

The feijoa plant (Feijoa sellowiana, family Myrtaceae, synonym, Acca sellowiana) produces fruit similar to that of the guava. It is native to Brazil but is grown in many countries as a food crop, especially New Zealand, where it is valued for its highly aromatic fruit. This review covers published work on the bioactive components of the fruit of the feijoa and their pharmacology. Potential value might be added to this fruit if extracts of the fruit were to be used for nutraceutical purposes. © 2010 Elsevier Ltd. All rights reserved. Source

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