3,604 research outputs found
Leisure settings: Bourgeois culture, medicine, and the spa in modern France. (book review)
Book review
Luminescent solar concentrators : a study of optical properties, re-absorption and device optimisation
This thesis presents the results of work on the optical properties and design optimisation
of the luminescent solar concentrator (LSC).
The optical properties of a range of
uorophores were measured and it was found
that the Lumogen F Rot 305 organic dye exhibited properties which make it ideal
for use in LSCs, namely a wide absorption range (300-650 nm), 100% quantum yield
at concentrations up to 1700 ppm, and the highest photostability of all the Lumogen
F dyes, although the overlap of the absorption and emission spectra results in reabsorption
(RA) losses.
Despite these optimum properties, a detailed analysis showed that LSCs based on
Rot 305 cannot compete with conventional glass/glass laminate modules on grounds
of either cost or embodied energy. Since Rot 305 represents an optimum dye, this
suggests it is unlikely that LSCs based on organic dyes will ever be competitive with
conventional technologies. The only solution is the use of a
uorophore with greatly
reduced RA losses, for example a rare-earth (RE) complex. The RA losses of a
europium-containing complex were found to be less than those of the Rot 305 dye,
despite the lower quantum yield of the complex (86 %).
The solar-to-electric conversion e ciencies of several LSC modules based on Rot 305
were measured. Modules with dimensions of 10 cm x 10 cm and 60 cm x 60 cm had
e ciencies of 2.7% and 1.84% respectively, both measured without a back re
ector.
In addition, the technique of current-matching the edge cells was successfully demonstrated,
resulting in a 15% increase in power output from an edge using matched cells
relative to an edge using unmatched cells
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Sharing Leadership in Top Teams: A Qualitative Case Study of One Governing Board in the Nonprofit Sector
Shared leadership is increasingly important in organisations today in order to meet the needs of changing environments, complex problems and to accommodate transparency and accountability. This is especially applicable to nonprofit organisations (NPOs) where good governance has been a concern for years not only because of underdeveloped theories of nonprofit governance (Cornforth, 2012) but also public pressure to demonstrate accountability, after reported cases of failed governance.
This research has a qualitative exploratory methodological design that interprets emerging data to develop and clarify concepts. The thesis adopts an ontological relativist position towards the epistemology of constructionism, and employs an intepretivist methodology to discuss findings and concepts.
The case study employs the concept of shared leadership, a mutual influence process in teams, (Pearce and Conger, 2003) and an ‘ethical form of board leadership’ for corporate boards following poor governance and various scandals (Vandewaerde et al, 2011, p.404) to explore sharing leadership and governance in one nonprofit board in practice. Three data collection techniques namely interviews, observation and document review have been carried out. Specifically, eight interviews, observation of one annual general meeting and one routine board meeting, and a review of 21 documents including seven board minutes and eight reports.
The participants richly described their experiences, having been identified using a Braun and Clarke (2006) interpretive process that examines the following themes; compliance; core purpose; expert knowledge and leadership. Findings inductively identified from the data suggest support for the concept of co-leadership between two individuals; for board governance moving towards a pluralist perspective in 2017; and changing context as the locus of leadership during 2014 – 2017
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