Roughness effect on heterojunction photovoltaics

In this work, we present an investigation of the junction interface roughness effect on the open circuit voltage, Voc for thin film heterojunction photovoltaics. The roughness effect is studied for self-affine rough interfaces, which are described in Fourier space by the correlation model ~σ^2ξ^2(1+aq^2ξ^2)^-1-H. σ, ξ, and H denote, respectively, the rms roughness, the in-plane roughness correlation length, and the interface irregularity exponent (0<H<1). The roughness effect becomes significant for small H (<0.5), and for large long-wavelength roughness of typical values σ/ξ~0.1. The junction interface roughness may yield a contribution to Voc even up to 10%. Comparison of the results is performed with predictions in real heterojunctions, e.g., CuxS/(Zn)CdS.

Using palladium membrane-used fuel reformers for combined heat and power (CHP) plants

Introduction It is widely accepted that the problem of global warming will require a combination of solutions ranging from carbon capture and sequestration (CCS) through to improved carbon effi ciency of fossil fuels and (in the long term) widespread use of renewable energy sources. In particular, as energy costs increase, the advantage of high energy-conversion effi ciency becomes very important. In this respect, fuel cell (FC) systems (with signifi cantly higher conversion efficiency than other energy conversion devices, particularly at small sizes) will become more important and their market share will increase accordingly (further enhanced by reductions in manufacturing costs). However, for FCs overall to achieve higher effi ciency, the energy carrier for those FCs (mostly H 2 ) should also be produced at higher effi ciency. This can be achieved by using membrane reactors, devices that integrate separation and reaction in a single unit, thus reducing the amount of equipment required and circumventing certain thermodynamic limitations that affect conventional systems. In this chapter, the application of membrane reactors as innovative reformers for combined heat and power (CHP) systems will be discussed. An overview of actual CHP systems will be outlined fi rst, then the advantages and disadvantages of applying novel reformers will be highlighted, and fi nally an energy analysis of a micro-CHP system with conventional and membrane reformers will be presented

Reducing fall risk with combined motor and cognitive training in elderly fallers

Falling is a major clinical problem in elderly people, demanding effective solutions. At present, the only effective intervention is motor training of balance and strength. Executive function-based training (EFt) might be effective at preventing falls according to evidence showing a relationship between executive functions and gait abnormalities. The aim was to assess the effectiveness of a motor and a cognitive treatment developed within the EU co-funded project I-DONT-FALL

Do acquirers manage earnings prior to a share for share bid?

Earnings management by acquirers ahead of share for share bids may affect whether a bid succeeds, and hence which management team controls the target's assets, as well as the distribution of gains between target and acquirer shareholders. This paper tests for such earnings management for the UK, the world's second largest takeover market, in the period 1997-2001 when M&A reached record levels and share for share deals came to account for the majority of expenditure. Using a range of approaches originating in Jones' model, the paper finds evidence consistent with earnings management ahead of share-financed bids