Economic Analysis of an Integrated Wind-Hydrogen Energy System for a Small Alaska Community

Wind-hydrogen systems provide one way to store intermittent wind energy as hydrogen. We explored the hypothesis that an integrated wind-hydrogen system supplying electricity, heat, and transportation fuel could serve the needs of an isolated (off-grid) Alaska community at a lower cost than a collection of separate systems. Analysis indicates that: 1) Combustible Hydrogen could be produced with current technologies for direct use as a transportation fuel for about $15/gallon-equivalent; 2) The capital cost of the wind energy rather than the capital cost of electrolyzers dominates this high cost; and 3) There do not appear to be diseconomies of small scale for current electrolyzers serving a a village of 400 people.United States Department of Energy. DOE Award Number: DE-FC26-01NT41248Introduction / Executive Summary / Experimental Methods / Results and Discussion / Conclusion / Bibliography / Appendix: Associated Excel Workbook

Using twins and scaling to construct cospectral graphs for the normalized Laplacian

The spectrum of the normalized Laplacian matrix cannot determine the number of edges in a graph, however finding constructions of cospectral graphs with differing number of edges has been elusive. In this paper we use basic properties of twins and scaling to show how to construct such graphs. We also give examples of families of graphs which are cospectral with a subgraph for the normalized Laplacian matrix

Electrowetting of a soap bubble

A proof-of-concept demonstration of the electrowetting-on-dielectric of a sessile soap bubble is reported here. The bubbles are generated using a commercial soap bubble mixture - the surfaces are composed of highly doped, commercial silicon wafers covered with nanometre thick films of Teflon. Voltages less than 40V are sufficient to observe the modification of the bubble shape and the apparent bubble contact angle. Such observations open the way to inter alia the possibility of bubble-transport, as opposed to droplet-transport, in fluidic microsystems (e.g. laboratory-on-a-chip) - the potential gains in terms of volume, speed and surface/volume ratio are non-negligible

Preparing for a post-Assad Syria: What role for the European Union? CEPS Commentary, 2 August 2012

In this CEPS Commentary, Steven Blockmans notes that a prolonged period of instability lies ahead for Syria, with an on-going risk of spill-over effects affecting the entire region. The author argues that the EU’s plans for a post-Assad Syria should extend beyond the half-hearted responses to the monumental changes that have ripped through other parts of the Arab world. In recognition of the geostrategic shifts in the Middle East and the Gulf, and pursuant to the obligation imposed upon it by the Lisbon Treaty, the EU should plan for the creation of a regional space of shared security. Such a plan would fit well into the current efforts to revamp the European Security Strategy

Exploring the use of a gap analysis approach for quantitative evaluation of teaching effectiveness

The article investigates the potential of an adaptation of the SERVQUAL approach for obtaining student feedback. The technique involves measuring the gaps between what students want in terms of teaching delivery and what they actually receive, thereby enabling areas for improvement to be identified. Improving the effectiveness of classroom teaching so as to enhance the students’ learning experience is frequently viewed as a key to raising retention rates. Student feedback, just one of many indicators of teaching quality, plays a crucial role in teaching enhancement. Whilst informal methods are also useful for teaching appraisal, this project investigates a formal approach for obtaining student feedback. If a SERVQUAL type approach can be adapted using a fairly short questionnaire then it may prove a useful alternative / supplement to traditional survey methods for evaluating teaching effectiveness. The project focuses on several undergraduate and postgraduate business Marketing modules and was conducted to see whether the technique offers any particular benefits which the Department of Business and Service Sector Management may use in the future