55 research outputs found
Modern customers and open universities: can open universities develop a course model in which students become the co-creators of value?
Marketing specialists have recently redefined the roles customers and enterprises play in the economy. Modern customers are connected, informed, mobile, educated and internationally oriented. They seek enterprises that empower them to co-construct personalised experiences. This view of the customer–enterprise relationship has a great impact on the ways markets function. Open universities can apply developed principles in marketing to optimise the value of their degree programmes. A capita selecta course within the Open University of the Netherlands has given students the opportunity to personalise learning. Within the limits of the formal Master programme, students were encouraged to define personal learning goals, study tasks and work to be delivered and formally assessed. In this paper, the course is analysed according to the principles of customer–enterprise relations, and I explore the question: can open universities develop a course model in which students become the co-creators of value
Mapping the internal recognition surface of an octanuclear coordination cage using guest libraries
Size and shape criteria for guest binding inside the cavity of an octanuclear cubic coordination cage in water have been established using a new fluorescence displacement assay to quantify guest binding. For aliphatic cyclic ketones of increasing size (from C5 to C11), there is a linear relationship between ΔG for guest binding and the guest’s surface area: the change in ΔG for binding is 0.3 kJ mol–1 Å–2, corresponding to 5 kJ mol–1 for each additional CH2 group in the guest, in good agreement with expectations based on hydrophobic desolvation. The highest association constant is K = 1.2 × 106 M–1 for cycloundecanone, whose volume is approximately 50% of the cavity volume; for larger C12 and C13 cyclic ketones, the association constant progressively decreases as the guests become too large. For a series of C10 aliphatic ketones differing in shape but not size, ΔG for guest binding showed no correlation with surface area. These guests are close to the volume limit of the cavity (cf. Rebek’s 55% rule), so the association constant is sensitive to shape complementarity, with small changes in guest structure resulting in large changes in binding affinity. The most flexible members of this series (linear aliphatic ketones) did not bind, whereas the more preorganized cyclic ketones all have association constants of 104–105 M–1. A crystal structure of the cage·cycloundecanone complex shows that the guest carbonyl oxygen is directed into a binding pocket defined by a convergent set of CH groups, which act as weak hydrogen-bond donors, and also shows close contacts between the exterior surface of the disc-shaped guest and the interior surface of the pseudospherical cage cavity despite the slight mismatch in shape
Molecular complex formation in the system poly(vinyl methyl ether)/water
The behaviour of poly(vinyl methyl ether) (PVME) in water has been studied in detail. A molecular complex with maximum two molecules of water per repeating unit is formed. The glass transition temperature of this complex is -58°C. Additional water plastisises and hydrates the complex. This conclusion is based on the detailed analysis of the concentration dependence of the glass transition of the system and melting behaviour of water. A similar behaviour is found with the chemical networks, obtained by radiation cross-linking
- …