Feeding back to feed forward:formative assessment as a platform for effective learning

Students construct meaning through relevant learning activities (Biggs, 2003) which are largely determined by the type, amount, and timing of feedback (Carless, 2006). The aim of the present study was to develop a greater awareness and understanding of formative assessment and feedback practices and their relationship with learning. During 2011 five focus group discussions were undertaken with students and academic staff involved with a range of modules and degree pathways at a UK University. Three of the focus groups were with undergraduate students (one at each level of study), and one was with taught postgraduate students. Discussions focussed on integration of formative assessment and feedback into modules, as well as an exploration of the effectiveness of feedback on future learning. The findings revealed that in order to emphasise continuous learning – feeding back to feed forward (Rushton, 2005) – and to encourage self-regulated learning (Nicol & Macfarlane-Dick, 2006), students need to have opportunities to make mistakes and to learn from them prior to summative assessment (through formative assessment and feedback). There was also firm evidence of different approaches to learning, emphasising in particular the transitional importance of the first year of study as the foundation upon which future achievement is built

What price planning? Reimagining planning as “market maker”

Planning has been widely vilified for the role it plays in disrupting the development process, hindering economic growth and creating the conditions for undersupply in housing markets, characterised by unaffordability. In this paper we hope to show that the analyses that support this view of planning are incomplete because of the theoretical limitations of the neoclassical tradition from which they emerge. By way of alternative we posit an account of planning that draws upon game theory and behavioural economics to explore those aspects of the activity that serve to animate the development process. This interpretation of planning as a “market maker” is explored through empirical case study research from three continental European contexts where planning is charged with playing an economically active role to control liquidity

Schottky Contacts on Polarity-Controlled Vertical ZnO Nanorods

Polarity-controlled growth of ZnO by chemical bath deposition provides a method for controlling the crystal orientation of vertical arrays of nanorods. The ability to define the morphology and structure of the nanorods is essential to maximising the performance of optical and electrical devices such as piezoelectric nanogenerators; however, well-defined Schottky contacts to the polar facets of the structures have yet to be explored. In this work, we demonstrate a process to fabricate metal-semiconductor-metal device structures from vertical arrays with Au contacts on the uppermost polar facets of the nanorods and show the O-polar nanorods (~0.44 eV) have a greater effective barrier height than the Zn-polar nanorods (~0.37 eV). Oxygen plasma treatment is shown by Cathodoluminescence (CL) spectroscopy to reduce mid-gap defects associated with radiative emissions that improves the Schottky contacts from weakly-rectifying to strongly-rectifying. Interestingly, the plasma treatment was shown to have a much greater effect in reducing the number of carriers in O-polar nanorods through quenching of the donor-type substitutional hydrogen on oxygen sites (HO) when compared to the zinc vacancy related hydrogen defect complexes (VZn, Hn) in Zn-polar nanorods that evolve to lower coordinated complexes. The effect on HO in the O-polar nanorods coincided with a large reduction in the visible range defects producing a lower conductivity and creating the larger effective barrier heights. This combination can allow radiative losses and charge leakage to be controlled enhancing devices such as dynamic photodetectors, strain sensors, and LEDs while showing the O-polar nanorods can outperform Zn-polar nanorods in such applications

Tunable Surface Properties of Aluminum Oxide Nanoparticles from Highly Hydrophobic to Highly Hydrophilic

The formation of materials with tunable wettability is important for applications ranging from antifouling to waterproofing surfaces. We report the use of various low-cost and nonhazardous hydrocarbon materials to tune the surface properties of aluminum oxide nanoparticles (NPs) from superhydrophilic to superhydrophobic through covalent functionalization. The hydrocarbon surfaces are compared with a fluorinated surface for wettability and surface energy properties. The role of NPs’ hydrophobicity on their dynamic interfacial behavior at the oil–water interface and their ability to form stable emulsions is also explored. The spray-coated NPs provide textured surfaces (regardless of functionality), with water contact angles (θ) of 10–150° based on their surface functionality. The superhydrophobic NPs are able to reduce the interfacial tension of various oil–water interfaces by behaving as surfactants

A magnetic analog of the isotope effect in cuprates

We present extensive magnetic measurements of the (Ca_xLa_{1-x})(Ba_{1.75-x}La_{0.25+x})Cu_{3}O_{y} (CLBLCO) system with its four different families (x) having a Tc^max(x) variation of 28% and minimal structural changes. For each family we measured the Neel temperature, the anisotropies of the magnetic interactions, and the spin glass temperature. Our results exhibit a universal relation Tc=c*J*n_s for all families, where c~1, J is the in plane Heisenberg exchange, and n_s is the carrier density. This relates cuprate superconductivity to magnetism in the same sense that phonon mediated superconductivity is related to atomic mass.Comment: With an additional inset in Fig.

Branched Hydrocarbon Low Surface Energy Materials for Superhydrophobic Nanoparticle Derived Surfaces

International audienceWe present a new class of superhydrophobic surfaces created from low-cost and easily synthesized aluminum oxide nanoparticles functionalized carboxylic acids having highly branched hydrocarbon (HC) chains. These branched chains are new low surface energy materials (LSEMs) which can replace environmentally hazardous and expensive fluorocarbons (FCs). Regardless of coating method and curing temperature, the resulting textured surfaces develop water contact angles (θ) of ~155° and root-mean-square roughnesses (Rq) ≈ 85 nm, being comparable with equivalent FC functionalized surfaces (θ = 157º and Rq = 100 nm). The functionalized nanoparticles may be coated onto a variety of substrates to generate different superhydrophobic materials