Optimizing the performance of thermionic devices using energy filtering

Conventional thermionic power generators and refrigerators utilize a barrier in the direction of transport to selectively transmit high-energy electrons. Here we show that the energy spectrum of electrons transmitted in this way is not optimal, and we derive the ideal energy spectrum for operation in the maximum power regime. By using suitable energy filters, such as resonances in quantum dots, the power of thermionic devices can, in principle, be improved by an order of magnitude.Comment: 3 pages, 2 figure

Home Drying of Foods

PDF pages: 1

Efficiency of Financial Institutions: International Survey and Directions for Future Research

This paper surveys 130 studies that apply frontier efficiency analysis to financial institutions in 21 countries. The primary goals are to summarize and critically review empirical estimates of financial institution efficiency and to attempt to arrive at a consensus view. We find that the various efficiency methods do not necessarily yield consistent results and suggest some ways that these methods might be improved to bring about findings that are more consistent, accurate, and useful. Secondary goals are to address the implications of efficiency results for financial institutions in the areas of government policy, research, and managerial performance. Areas needing additional research are also outlined.

More than the sum of its parts: Cumulative risk effects on school functioning in middle childhood.

BACKGROUND: Risk factors for poor school functioning rarely occur in isolation, but instead are likely to cluster together. As they accumulate, cumulative risk theory (CRT) predicts that the likelihood of negative outcomes increases, often disproportionately. AIMS: We build upon and extend previous research by (i) examining two critical aspects of school functioning (reading attainment and behavioural difficulties); (ii) utilizing a large number of candidate risk factors across multiple ecological domains; (iii) testing the two core assumptions of CRT; and (iv) formally examining the functional form of the risk-outcome relationships. SAMPLE: Participants were N = 3084 children aged 6-7 attending 77 mainstream primary schools in England. METHODS: Sixteen candidate risk factors (e.g., familial poverty) were modelled using data from the National Pupil Database. Reading attainment and behavioural difficulties data were generated via teachers' reading assessment scores and the Teacher Observation of Children's Adaptation Checklist (disruptive behaviour subscale), respectively. A cumulative risk score was generated for each pupil. Multilevel modelling was utilized for analysis. RESULTS: Six risk factors were identified for behaviour and seven for reading attainment. A cumulative risk effect was found for both outcomes, and the two core assumptions of CRT were supported. Quadratic relationships were found for both aspects of school functioning, indicative of a threshold effect. CONCLUSIONS: As the number of risk factors increases, difficulties in school functioning increase disproportionately. Consistent with CRT, our results suggest that the number of risks is more important than their nature. This has implications for future risk research and the implementation of school-based interventions

Open University Day Final Report

Final report on the Open University Day which was held on Saturday, October 17, 2016 as part of UMaine’s 150th Anniversary Celebration which was held in conjunction with Homecoming and Family & Friends Weekend