Controlling Hierarchy in Solution‐processed Polymer Solar Cells Based on Crosslinked P3HT

Understanding and controlling the morphology of donor/acceptor blends is critical for the development of solution processable organic solar cells. By crosslinking a poly(3‐n‐hexylthiophene‐2,5‐diyl) (P3HT) film we have been able to spin‐coat [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PCBM) onto the film to form a structure that is close to a bilayer, thus creating an ideal platform for investigating interdiffusion in this model system. Neutron reflectometry (NR) demonstrates that without any thermal treatment a smaller amount of PCBM percolates throughout the crosslinked P3HT when compared to a non‐crosslinked P3HT film. Using time‐resolved NR we also show thermal annealing increases the rate of diffusion, resulting in a near‐uniform distribution of PCBM throughout the polymer film. XPS measurements confirm the presence of both P3HT and PCBM at the annealed film's surface indicating that the two components are intermixed. Photovoltaic devices fabricated using this bilayer approach and suitable annealing conditions yielded comparable power conversion efficiencies to bulk heterojunction devices made from the same materials. The crosslinking procedure has also enabled the formation of patterned P3HT films by photolithography. Pillars with feature sizes down to 2 μm were produced and after subsequent deposition of PCBM and thermal annealing devices with efficiencies of up to 1.4% were produced.     

The Economic Impact of Pig-Associated Parasitic Zoonosis in Northern Lao PDR

The parasitic zoonoses human cysticercosis (Taenia solium), taeniasis (other Taenia species) and trichinellosis (Trichinella species) are endemic in the Lao People’s Democratic Republic (Lao PDR). This study was designed to quantify the economic burden pig-associated zoonotic disease pose in Lao PDR. In particular, the analysis included estimation of the losses in the pork industry as well as losses due to human illness and lost productivity. A Markov-probability based decision-tree model was chosen to form the basis of the calculations to estimate the economic and public health impacts of taeniasis, trichinellosis and cysticercosis. Two different decision trees were run simultaneously on the model’s human cohort. A third decision tree simulated the potential impacts on pig production. The human capital method was used to estimate productivity loss. The results found varied significantly depending on the rate of hospitalisation due to neurocysticerosis. This study is the first systematic estimate of the economic impact of pig-associated zoonotic diseases in Lao PDR that demonstrates the significance of the diseases in that country.     

Evaluation of the performance and accuracy of Global Positioning System bug transmitters deployed on a small mammal

Recent technological advances in Global Positioning System (GPS) telemetry have allowed the production of lightweight devices suitable for use on small mammals. We evaluated the use of GPS bugs on the European hedgehog (Erinaceus europaeus) in a series of static and field tests. Static tests were conducted in five different rural habitats, affording different degrees of obstruction to satellites. GPS bug performance was good in all habitats (fix success rate (FSR): median ≥?66.8 %; location error (LE): mean ≤?13.5 m), except woodland (FSR?=?37.7 %; LE?=?15.6 m), with performance highest in the open pasture habitat (FSR?=?100 %; LE?=?6.4 m). Field tests revealed mean FSR was high (84.6 %), with the use of nesting habitats, the probable cause of most failed fixes. Despite being more expensive, GPS bugs require less survey effort and substantially lower labour costs with unlimited longevity permitting re-use in multiple seasons. We recommend the use of GPS bugs in the spatial ecological study of any small mammal in a rural environment, providing accurate and unbiased movement data. Further performance testing is recommended before deployment on species inhabiting forested habitats where reduced FSR and high LE support the alternative use of very high frequency tracking.