Thermoelectric properties of p-type LiZnSb: Assessment of ab initio calculations

In response to theoretical calculations on the thermoelectric performance of LiZnSb, we report the pertinent transport properties between room temperature and 523 K. Nominal LiZnSb samples are found to be p-type, with a carrier concentration in the range (4–7)×10^(20) cm^(−3). The thermoelectric figure of merit (zT) is found to be 0.02–0.08 at 523 K. Analysis of material transport parameters and previously reported ab initio calculations demonstrates that even with optimal doping, p-type LiZnSb is unlikely to achieve zT>0.2 at 523 K. The accuracy of the high zT estimate (zT>2) for n-type compositions from ab initio calculations is discussed within the current synthetic limits

Topological Hochschild homology of Thom spectra and the free loop space

We describe the topological Hochschild homology of ring spectra that arise as Thom spectra for loop maps f: X->BF, where BF denotes the classifying space for stable spherical fibrations. To do this, we consider symmetric monoidal models of the category of spaces over BF and corresponding strong symmetric monoidal Thom spectrum functors. Our main result identifies the topological Hochschild homology as the Thom spectrum of a certain stable bundle over the free loop space L(BX). This leads to explicit calculations of the topological Hochschild homology for a large class of ring spectra, including all of the classical cobordism spectra MO, MSO, MU, etc., and the Eilenberg-Mac Lane spectra HZ/p and HZ.Comment: 58 page

Overcoming the barriers to implementing urban road user charging schemes

Urban road user charging offers the potential to achieve significant improvements in urban transport, but is notoriously difficult to implement. Cities need guidance on the range of factors to be considered in planning and implementing such schemes. This paper summarises the results of a 3 year programme which has collated evidence on the issues of most concern to cities. A state of the art report has provided evidence on 14 themes, ranging from objectives and design to implementation and evaluation. A set of 16 case studies has reviewed experience in design and implementation across Europe. The paper summarises their findings, provides references to more detailed information, presents the resulting policy recommendations to European, national and local government, and outlines the areas in which further research is needed

Do food banks help? Food insecurity in the UK.

Belgium Herbarium image of Meise Botanic Garden

Relevance of volunteered geographic information in a real world context

Volunteered Geographic Information has the potential to offer value and usability benefits to end-users over and above that of Professional Geographic Information. For this to be accomplished, the user centred factors of both information types must be understood in detail. Through a series of focus groups, the differences between volunteer and professional information sources are investigated relative to the characteristics which are the most, or least relevant to the end-user. These findings have implications for how different forms of information may be most effectively utilised within different usage situations

Using VGI to enhance user judgements of quality and authority

Amateur Volunteered Geographic Information (VGI) has been used together with Professional Geographic Information (PGI) since its inception during the mid 00's alongside neogeography. While the geographic accuracy and quality of VGI has been demonstrated to be more than good enough, no previous research has been published on the influence VGI has on the user perceptions of the mashup. This paper presents a quantitative investigation into how including VGI in mashups, and telling users their mashup contains VGI influences user perceptions of quality and authority- which ultimately decide if the user wishes to utilise the mashup or not

An exploration of Volunteered Geographic Information stakeholders

Volunteered Geographic Information (VGI) has huge potential for influencing the use of geographic information systems. However, there is a wide range of individuals involved in this process, each with their own motivations for contributing and using volunteered data. This paper investigates the range of stakeholders involved with VGI, their relationships and the main tensions and issues involved. The research was based on a series of detailed interviews and theory-driven coding of data. From this, a Rich Picture (Monk, Howard 1998) was developed to graphically present and relate stakeholder relationship information. The findings have implications for how stakeholder groups may be described, and how VGI can lead to enhanced products and services