Economic Evaluation of Irrigated Dairy Forage Production.

An optimisation model was developed to compare the profitability of different forage species on irrigated dairy farms. The model is driven by the energy and protein requirements of the milking cow. The objective of the model is to maximise income, after herd and feed costs, by selecting the area of the farm sown to particular forage species. Different forage species may require different animal production systems to optimise their profitability. In order to achieve this, the model can alter the herd size and structure, level of production, concentrate feeding regime and forage conservation and feeding on a monthly basis.Dairy cows, Modelling, Forage., Farm Management,

Optical sensing with Anderson-localised light

We show that fabrication imperfections in silicon nitride photonic crystal waveguides can be used as a resource to efficiently confine light in the Anderson-localised regime and add functionalities to photonic devices. Our results prove that disorder-induced localisation of light can be utilised to realise an alternative class of high-quality optical sensors operating at room temperature. We measure wavelength shifts of optical resonances as large as 15.2 nm, more than 100 times the spectral linewidth of 0.15\,nm, for a refractive index change of about 0.38. By studying the temperature dependence of the optical properties of the system, we report wavelength shifts of up to about 2 nm and increases of more than a factor 2 in the quality factor of the cavity resonances, when going from room to cryogenic temperatures. Such a device can allow simultaneous sensing of both local contaminants and temperature variations, monitored by tens of optical resonances spontaneously appearing along a single photonic crystal waveguide. Our findings demonstrate the potential of Anderson-localised light in photonic crystals for scalable and efficient optical sensors operating in the visible and near-infrared range of wavelengths.Comment: 10 pages, 3 figure