Thin-film GaAs photovoltaic solar energy cells Final report

Thin film gallium arsenide photovoltaic solar cell

Genetic computation of geodesics on three-dimensional curved surfaces

Most classical approaches to the determination of geodesics (such as the calculus of variations) are difficult to apply except for simple surfaces. Genetic algorithms are therefore used to provide a general methodology for the computation of geodesics.published_or_final_versio

Room temperature self-assembly of mixed nanoparticles into complex material systems and devices

The ability to manufacture nanomaterials with complex and structured composition using otherwise incompatible materials increasingly underpins the next generation of technologies. This is translating into growing efforts integrating a wider range of materials onto key technology platforms1 - in photonics, one such platform is silica, a passive, low loss and robust medium crucial for efficient optical transport2. Active functionalisation, either through added gain or nonlinearity, is mostly possible through the integration of active materials3, 4. The high temperatures used in manufacturing of silica waveguides, unfortunately, make it impossible to presently integrate many organic and inorganic species critical to achieving this extended functionality. Here, we demonstrate the fabrication of novel waveguides and devices made up of complex silica based materials using the self-assembly of nanoparticles. In particular, the room temperature fabrication of silica microwires integrated with organic dyes (Rhodamine B) and single photon emitting nanodiamonds is presented.Comment: Key words: nanotechnology, nanoparticles, self-assembly, quantum science, singel photon emitters, telecommunications, sensing, new materials, integration of incompatible materials, silica, glass, breakthrough scienc

Progress in thin film GaAs solar cells

Solar cells using polycrystalline films of gallium arsenid

Thin film GaAs photovoltaic solar energy cells

Fabrication process for thin film gallium arsenide photovoltaic solar energy cell

Age-related differences in foot mobility in individuals with patellofemoral pain

Background Age-related changes in midfoot mobility have the potential to influence success with foot orthoses intervention in people with patellofemoral pain (PFP). The aim of this study was to determine whether older people with PFP demonstrate less foot mobility than younger adults with PFP. Methods One hundred ninety four participants (113 (58%) women, age 32 ± 7 years, BMI 25 ± 4.9 kg/m2) with PFP (≥ 6 weeks duration) were included, with foot mobility quantified using reliable and valid methods. K-means cluster analysis classified participants into three homogenous groups based on age. After cluster formation, univariate analyses of co-variance (covariates: sex, weight) were used to compare midfoot height mobility, midfoot width mobility, and foot mobility magnitude between age groups (significance level 0.05). Results Cluster analysis revealed three distinct age groups: 18–29 years (n = 70); 30–39 years (n = 101); and 40–50 years (n = 23). There was a significant main effect for age for midfoot height mobility (p  0.05). Conclusion Individuals with PFP aged 40–50 years have less foot mobility than younger adults with PFP. These findings may have implications for evaluation and treatment of older individuals with PFP

Benchmarking 2D hydraulic models for urban flood simulations

This paper describes benchmark testing of six two-dimensional (2D) hydraulic models (DIVAST, DIVASTTVD, TUFLOW, JFLOW, TRENT and LISFLOOD-FP) in terms of their ability to simulate surface flows in a densely urbanised area. The models are applied to a 1·0 km × 0·4 km urban catchment within the city of Glasgow, Scotland, UK, and are used to simulate a flood event that occurred at this site on 30 July 2002. An identical numerical grid describing the underlying topography is constructed for each model, using a combination of airborne laser altimetry (LiDAR) fused with digital map data, and used to run a benchmark simulation. Two numerical experiments were then conducted to test the response of each model to topographic error and uncertainty over friction parameterisation. While all the models tested produce plausible results, subtle differences between particular groups of codes give considerable insight into both the practice and science of urban hydraulic modelling. In particular, the results show that the terrain data available from modern LiDAR systems are sufficiently accurate and resolved for simulating urban flows, but such data need to be fused with digital map data of building topology and land use to gain maximum benefit from the information contained therein. When such terrain data are available, uncertainty in friction parameters becomes a more dominant factor than topographic error for typical problems. The simulations also show that flows in urban environments are characterised by numerous transitions to supercritical flow and numerical shocks. However, the effects of these are localised and they do not appear to affect overall wave propagation. In contrast, inertia terms are shown to be important in this particular case, but the specific characteristics of the test site may mean that this does not hold more generally