Dose measurements in pre-clinical and radiobiology studies are frequently inadequate, thus undermining the reliability and reproducibility of the published findings.

The growth of ideal compound semiconductors can be challenging. Threading dislocations are inherent growth side effects of III-nitrides material systems and they can limit the optoelectronic performance of the resulting devices.

Smart Antenna Technologies Research at NPL.

Improved method for the measurement of the glass transition temperature by Dynamic Mechanical Analysis (DMA) – a VAMAS international validation exercise.

Siloxane impurities within biogas can cause extensive damage to gas processing equipment if not removed effectively. A European specification is being developed that will impose a maximum limit value on the total silicon content of biogas in order for it to be safely utilised. This requirement for accurate measurements of total silicon at low amount fractions has driven advances in measurement methods as part of a European project.

How NPL's engineering department and capabilities have changed throughout the years.

The market growth of conductive inks for flexible and printed electronics is predicted to increase from $2.3 billion to $3.2 billion by 2025 ^[1]. It is important that we are able to verify the electrical properties of printed electronics to maintain output quality and reduce wastage. Therefore we are driven to find a suitable non-contact technique suitable to measure the electrical properties of the printed structures during manufacture in a roll-to-roll process.

The emphasis of the work reported here is to use inductive sensors to measure electrical response. The impedance of an inductive sensor is affected by eddy currents induced in nearby conductors such that the electrical loss will be increased. The electrical response will be affected by a number of factors including material resistivity and thickness, temperature and sensor lift-off (distance between sample and sensor).

By controlling temperature and lift-off, we are able to use an inductive sensor to measure electrical impedance and relate it to the electrical properties of printed ink structures. By combining the electrical measuring system with another (such as optical) into a single metrology system for evaluating film properties, with extra thickness and lift-off data, it would be possible to extract the actual electrical resistivity of printed tracks and films.

Gas bubbles on the order of 1-10 μm in radius and stabilized by a coating of biological surfactant have found use as contrast agents for ultrasound imaging and, more recently, have shown a clear potential as targeted drug delivery vectors. The characterisation of the acoustic properties of these microbubbles is important in order to validate simulations and improve their design, thereby leading to safer, more clinically-effective and cost-effective medical products. In order to perform this characterization at the single bubble level, a system has been constructed based upon simultaneous use of optical and acoustic trapping (NPL sono-optical tweezers), with the former providing the reference force calibration and a finer manipulation than the latter.

The progressive diffusion of Al from coating into ferritic-martensitic substrate has been one of the main factors against the application of aluminide slurries on an industrial scale as it might affect the materials long term creep properties.

This paper presents results on the effect of a prolonged exposure to steam on the creep behaviour of a coated steel substrate.

Measurements of dielectric constant of human skin in vivo at THz frequencies using time-domain spectroscopy.

Polymer electrolyte membrane water electrolysers (PEMWE) are a promising technology for renewable hydrogen production. Here we present an investigation of catalyst degradation in PEMWEs using an innovative reference electrode.