Peter K. O’Brien

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Statistics NZ for their support in organising access to the data and for guidance and comments. Malcolm McKee of the Treasury answered endless questions about benefits and Ivan Tuckwell provided valuable assistance in the analysis of the Household Economic Survey. David Feslier of the Office of the Retirement Commission (ORC) has been instrumental in(More)
We are developing a 4 to 8 GHz cryogenic low-noise amplifier (LNA) using Quasi-Monolithic Microwave Integrated Circuit (QMMIC) technology. This amplifier has been demonstrated as an IF amplifier of a 690 GHz quasi-optical SIS receiver for the Caltech Submillimeter Observatory (CSO), and later will be used on SOFIA. The QMMIC consists of a thin-film passive(More)
We examined in detail the optical properties of NaYF 4 :Eu 3? nanocrystals of *9 nm in diameter. For such small nanocrystals roughly 17 % of Y 3? ions occupy surface sites and can be efficiently substituted by optically active Eu 3? ions. In order to determine the influence of surface Eu 3? on the optical properties of the whole nanocrystal, small b-NaY-F 4(More)
Dedicated multi-project wafer (MPW) runs for photonic integrated circuits (PICs) from Si foundries mean that researchers and small-to-medium enterprises (SMEs) can now afford to design and fabricate Si photonic chips. While these bare Si-PICs are adequate for testing new device and circuit designs on a probe-station, they cannot be developed into prototype(More)
Recreational water quality is commonly monitored by means of culture based faecal indicator organism (FIOs) assays. However, these methods are costly and time-consuming; a serious disadvantage when combined with issues such as non-specificity and user bias. New culture and molecular methods have been developed to counter these drawbacks. This study compared(More)
To evaluate cervix brachytherapy dosimetry with the introduction of magnetic resonance (MR) based treatment planning and volumetric prescriptions and propose a method for plan evaluation in the transition period. The treatment records of 69 patients were reviewed retrospectively. Forty one patients were treated using computed tomography (CT)-based, Point(More)
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