Unhealthy food marketing to New Zealand children and adolescents through the internet.

AIM: To assess the extent and nature of unhealthy food marketing to New Zealand children and adolescents through the internet. METHODS: Internet traffic data for January 2014 was purchased from AC Nielsen to identify the most popular websites (n=110) among children and adolescents aged 6-17 years. In addition, websites (n=70) of food and beverage brands most frequently marketed to children through television, sports, magazines and Facebook were included. Marketing techniques and features on those websites were analysed. RESULTS: The extent of food marketing on popular non-food websites was low. A wide range of marketing techniques and features was, however, identified on food brand websites, including advercation (87%), viral marketing (64%), cookies (54%), free downloadable items (43%), promotional characters (39%), designated children's sections (19%) and advergaming (13%). Most techniques appeared more frequently on websites specifically targeting children and adolescents, than on other websites targeting the general public. CONCLUSION: Compared to traditional media, the internet allows food marketers to use engaging techniques to directly interact with children. While the range of marketing techniques and features identified on food brand websites was extensive, the most popular websites among children and adolescents were non-food related, and the extent of food marketing on those websites was found to be low. Additional assessment of food marketing to children through social and other digital media is recommended.

Development and characterization of a high yield transportable pulsed neutron source with efficient and compact pulsed power system.

The results of characterization experiments carried out on a newly developed dense plasma focus device based intense pulsed neutron source with efficient and compact pulsed power system are reported. Its high current sealed pseudospark switch based low inductance capacitor bank with maximum stored energy of ∼10 kJ is segregated into four modules of ∼2.5 kJ each and it cumulatively delivers peak current in the range of 400 kA-600 kA (corresponding to charging voltage range of 14 kV-18 kV) in a quarter time period of ∼2 µs. The neutron yield performance of this device has been optimized by discretely varying deuterium filling gas pressure in the range of 6 mbar-11 mbar at ∼17 kV/550 kA discharge. At ∼7 kJ/8.5 mbar operation, the average neutron yield has been measured to be in the order of ∼4 × 109 neutrons/pulse which is the highest ever reported neutron yield from a plasma focus device with the same stored energy. The average forward to radial anisotropy in neutron yield is found to be ∼2. The entire system is contained on a moveable trolley having dimensions 1.5 m × 1 m × 0.7 m and its operation and control (up to the distance of 25 m) are facilitated through optically isolated handheld remote console. The overall compactness of this system provides minimum proximity to small as well as large samples for irradiation. The major intended application objective of this high neutron yield dense plasma focus device development is to explore the feasibility of active neutron interrogation experiments by utilization of intense pulsed neutron sources.

Transmission line transformer for reliable and low-jitter triggering of a railgap switch.

The performance of railgap switch critically relies upon multichannel breakdown between the extended electrodes (rails) in order to ensure distributed current transfer along electrode length and to minimize the switch inductance. The initiation of several simultaneous arc channels along the switch length depends on the gap triggering technique and on the rate at which the electric field changes within the gap. This paper presents design, construction, and output characteristics of a coaxial cable based three-stage transmission line transformer (TLT) that is capable of initiating multichannel breakdown in a high voltage, low inductance railgap switch. In each stage three identical lengths of URM67 coaxial cables have been used in parallel and they have been wounded in separate cassettes to enhance the isolation of the output of transformer from the input. The cascaded output impedance of TLT is ~50 Ω. Along with multi-channel formation over the complete length of electrode rails, significant reduction in jitter (≤2 ns) and conduction delay (≤60 ns) has been observed by the realization of large amplitude (~80 kV), high dV/dt (~6 kV/ns) pulse produced by the indigenously developed TLT based trigger generator. The superior performance of TLT over conventional pulse transformer for railgap triggering application has been compared and demonstrated experimentally.