In-situ, real time gas composition measurements for SOFC's using laser spectroscopy

The use of standard gas composition measurement techniques, such as gas chromatography, in large scale solid oxide fuel cells (SOFC's) operating at high temperatures can be both complex and time consuming. One of the main constraints is the necessity to condense out the water vapour present in the gas streams prior to measurement in the Gas Chromatograph (GC). True gas compositions can only be extracted through back-calculation, with each measurement taking in the order of minutes, and a number of measurement points needed to make the final measurement. For system status monitoring such a time delay between condition changes and measurement is a serious disadvantage. One of the main concerns for systems running on natural gas is the risk of methane slippage through the internal reformer, which increases the risk of carbon formation on the SOFC anode, invariably leading to irreversible loss of performance. It is therefore highly advantageous to measure gas stream compositions within the SOFC system in real time, enabling a rapid response to composition deviation outside of acceptable limits. Gas chromatography can never be made to work as a real-time system status monitoring product solution. A suitable, in-situ, solution for measurement is tuneable diode laser spectroscopy, TDLS. Using this technique it is possible to measure both the gas concentration and system pressure simultaneously for a number of different species, without condensing out the water vapour: reducing analysis time considerably and reducing errors associated with back calculation. In this paper, data taken on an operational fuel cell system is presented for methane, and a comparison with results obtained using a GC is made

Exploring the Relationship between Membership Turnover and Productivity in Online Communities

One of the more disruptive reforms associated with the modern Internet is the emergence of online communities working together on knowledge artefacts such as Wikipedia and OpenStreetMap. Recently it has become clear that these initiatives are vulnerable because of problems with membership turnover. This study presents a longitudinal analysis of 891 WikiProjects where we model the impact of member turnover and social capital losses on project productivity. By examining social capital losses we attempt to provide a more nuanced analysis of member turnover. In this context social capital is modelled from a social network perspective where the loss of more central members has more impact. We find that only a small proportion of WikiProjects are in a relatively healthy state with low levels of membership turnover and social capital losses. The results show that the relationship between social capital losses and project performance is U-shaped, and that member withdrawal has significant negative effect on project outcomes. The results also support the mediation of turnover rate and network density on the curvilinear relationship

Bacterial Succession during Decomposition

Undergraduate Basi

A Platform for Proactive, Risk-Based Slope Asset Management, Phase II

INE/AUTC 15.0

EU membership was a cultural symbol which Remainers approved and Leavers disliked

Provision of more facts and objective information would have been of marginal significance in the Brexit vote. Michael Cunningham (University of Wolverhampton) offers his reflections on the EU referendum that point to the existence of substantial political limitations of evidence. He argues that one observes a widespread tendency among many voters to be resistant to facts challenging positions they hold. He ..

The political limitations of evidence: a critique of the electoral reform society's it's good to talk

The Electoral Reform Society has called for more and better quality information to improve democratic debate in relation to referendums. This article argues that, particularly in relation to the European Union referendum, this would have had a marginal impact, because much of the debate was not reducible to facts and emotional and dispositional factors were of particular significance in the campaign

“Two wheels bad”? : the status of cycling in the Youth Hostels Association of England and Wales in the 1930s

The Youth Hostels Association (YHA) was founded to provide cheap accommodation for rural holidays. It catered for both walkers and cyclists. However, many perceived the organisation as one that favoured walkers, considering walking to be a superior form of travel which was also reflected in YHA policy. Despite this, the YHA had close institutional links with cycling organisations and many cyclists among its members. This article traces the YHA’s relationship with walkers and cyclists and, despite occasional tensions, shows that the two groups could be accommodated within the organisatio

Integrating Public, Private, and Homeschool Students Into a Cohesive Youth Ministry

Parents make agonizing educational decisions for their children, and there are more options than ever before. Some opt to teach their children in the home; others pay handsomely to put their children in the best private schools money can buy. The remaining groups of parents select public, charter, or magnet schools based on those schools’ particular merits or because those schools represent their primary educational option. These subtle lifestyle decisions are building blocks upon which students develop their personality, intellectual ambition, extracurricular interests, and social networks. Neighborhoods, schools, and community activities are often as influential in the formation of a student’s identity as their socioeconomic background, cultural heritage, or family milieu. With the erosion of neighborhood relationships and detachment from traditional norms, educational institutions provide a comprehensive solution for busy families to organize the educational, social, and recreational aspects of their lifestyles. Schools, therefore, have become the new neighborhood in American life. Pastors tend to be ill-prepared for the unique dynamics families bring to the church from their various walks of life. This paper will examine methods for assimilating public, private, and homeschool students into a cohesive student ministry where they can retain their identity, be enriched by other students’ experiences, and, most importantly, be united by their faith in serving Christ in their student ministry and in the greater church body

REANALYSIS OF THE NATIONAL CANCER INSTITUTE'S ACRYLONITRILE COHORT STUDY BY IMPUTATION OF MISSING SMOKING INFORMATION

A cohort study of workers exposed to the chemical acrylonitrile (AN) was carried-out in the late 1980s by the National Cancer Institute (NCI) to determine if there were any excess cancer risks associated with workplace exposures to AN. The results of the study did not show any overwhelming evidence that AN exposure was related to increased cancer risk, but did yield several results worth noting. Firstly, the authors reported an overall lung cancer risk of 3.6 for ever-smokers versus never-smokers, which appeared to be much too low. Secondly, there was a slight increase in the lung cancer relative risk due to exposure in the upper quintile of cumulative AN exposure. Lastly, there was a large proportion of missing smoking information for the employees selected in the sample.Because results of occupational cohort studies such as the NCI's are used as the basis for determining health risks associated with workplace exposures and because acrylonitrile is widely used in the manufacturing of plastics, it is very important from a public health perspective to eliminate any possible sources of confounding or bias. The goal of this reanalysis is to address the issues of missing smoking information and the low overall lung cancer relative risk in ever-smokers to determine if the slight excess in the highest AN exposure category appears to be valid. This was accomplished using imputation, a procedure that predicts a smoking status for the missings based on complete observations. The NCI analyses were then repeated with the imputed data to see if there were any differences in the overall smoking lung cancer RR or the lung cancer RR in the upper quintile of AN exposure.The overall lung cancer RR due smoking could not be increased dramatically using the weighting schemes in this paper. Also, the lung cancer RRs in the upper quintile of AN exposure were not much lower than those in the original NCI study, so their analysis with the missing smoking information does not appear to have been biased. However, the smoking adjusted lung cancer RRs for cumulative AN exposure using the imputed data have a much flatter exposure-response trend than the NCI analysis, which, when combined with the only slightly elevated RR in the upper exposure group, could be used as evidence against an increased lung cancer risk due to high AN exposure