The Reverse Side of the Medal: About the 2010 FIFA World Cup and the Beautification of the N2 in Cape Town

This paper aims to show the reverse side of the (football) medal. The N2 gateway project in Cape Town is presented, by government and media, as a ‘flagship’ project of the new Breaking New Ground strategy, to fight the housing backlog of 400,000 houses in the city. But I want to argue that the fast-tracking of the project has to be understood as a beautification strategy to prepare the city for 2010. Massive slum eradication and the construction of ‘beautiful formal housing opportunities’ between the airport and the mother city are becoming a painful reminder of the forced removals under the apartheid regime.

Crops that feed the world 4. Barley: a resilient crop? Strengths and weaknesses in the context of food security

Barley is cultivated both in highly productive agricultural systems and also in marginal and subsistence environments. Its distribution is worldwide and is of considerable economic importance for animal feed and alcohol production. The overall importance of barley as a human food is minor but there is much potential for new uses exploiting the health benefits of whole grain and beta-glucans. The barley supply chains are complex and show added value at many stages. Germplasm resources for barley are considerable, with much potential for exploitation of its biodiversity available through the use of recently developed genomic and breeding tools. Consequently, substantial gains in crucial sustainability characteristics should be achievable in the future, together with increased understanding of the physiological basis of many agronomic traits, particularly water and nutrient use efficiency. Barley’s ability to adapt to multiple biotic and abiotic stresses will be crucial to its future exploitation and increased emphasis on these traits in elite germplasm is needed to equip the crop for environmental change. Similarly, resource use efficiency should become a higher priority to ensure the crop’s sustainability in the long-term. Clearly barley is a resilient crop with much potential which can be realised in the future.     

Invited article: the fast readout low noise camera as a versatile x-ray detector for time resolved dispersive extended x-ray absorption fine structure and diffraction studies of dynamic problems in materials science, chemistry, and catalysis

Originally conceived and developed at the European Synchrotron Radiation Facility (ESRF) as an "area" detector for rapid x-ray imaging studies, the fast readout low noise (FReLoN) detector of the ESRF [J.-C. Labiche, ESRF Newsletter 25, 41 (1996)] has been demonstrated to be a highly versatile and unique detector. Charge coupled device (CCD) cameras at present available on the public market offer either a high dynamic range or a high readout speed. A compromise between signal dynamic range and readout speed is always sought. The parameters of the commercial cameras can sometimes be tuned, in order to better fulfill the needs of specific experiments, but in general these cameras have a poor duty cycle (i.e., the signal integration time is much smaller than the readout time). In order to address scientific problems such as time resolved experiments at the ESRF, a FReLoN camera has been developed by the Instrument Support Group at ESRF. This camera is a low noise CCD camera that combines high dynamic range, high readout speed, accuracy, and improved duty cycle in a single image. In this paper, we show its application in a quasi-one-dimensional sense to dynamic problems in materials science, catalysis, and chemistry that require data acquisition on a time scale of milliseconds or a few tens of milliseconds. It is demonstrated that in this mode the FReLoN can be applied equally to the investigation of rapid changes in long range order (via diffraction) and local order (via energy dispersive extended x-ray absorption fine structure) and in situations of x-ray hardness and flux beyond the capacity of other detectors.     

Photoinduced Self‐Assembled Nanostructures and Permanent Polaron Formation in Regioregular Poly(3‐hexylthiophene)

Solution processing of conjugated polymers into ordered self‐assembled precursors has attracted great interest in the past years owing to the ability to manipulate their structural and physical properties. Regioregular poly(3‐hexylthiophene) (P3HT) has become the benchmark polymer in this scenario, where ordered lamellar structures significantly improve carrier mobility of the thin films due to increased crystallinity, extended intrachain conjugation, and ordered interchain π‐stacking. Here, a new photoinduced approach is presented for the generation of highly ordered P3HT aggregate structures that is amenable to the use of visible light to control the aggregate formation. Strong intra‐ and interchain interactions in the solution precursors allow for permanent formation of localized and delocalized polarons that are stable for months. Spin‐coated thin films are found to preserve, in part, the morphological and physical properties of the aggregated P3HT solution precursors with high degree of crystallinity and short π‐stack interchain distances.     

Process,Policy, and Implementation of Pool‐Wide Drawdowns on the Upper Mississippi River: A Promising Approach for Ecological Restoration of Large Impounded Rivers

The Upper Mississippi River (UMR) has been developed and subsequently managed for commercial navigation by the U.S. Army Corps of Engineers (USACE). The navigation pools created by a series of lock and dams initially provided a complex of aquatic habitats that supported a variety of fish and wildlife. However, biological productivity declined as the pools aged. The River Resources Forum, an advisory body to the St. Paul District of the USACE, established a multiagency Water Level Management Task Force (WLMTF) to evaluate the potential of water level management to improve ecological function and restore the distribution and abundance of fish and wildlife habitat. The WLMTF identified several water level management options and concluded that summer growing season drawdowns at the pool scale offered the greatest potential to provide habitat benefits over a large area. Here we summarize the process followed to plan and implement pool‐wide drawdowns on the UMR, including involvement of stakeholders in decision making, addressing requirements to modify reservoir operating plans, development and evaluation of drawdown alternatives, pool selection, establishment of a monitoring plan, interagency coordination, and a public information campaign. Three pool‐wide drawdowns were implemented within the St. Paul District and deemed successful in providing ecological benefits without adversely affecting commercial navigation and recreational use of the pools. Insights are provided based on more than 17 years of experience in planning and implementing drawdowns on the UMR. Copyright © 2015 John Wiley & Sons, Ltd.     

Development of an inexpensive, high-accuracy diamond turning machine

A small, numerically controlled, two-axis diamond lathe for parts up to 100 mm diameter has been assembled from commercially available components in two weeks. The machine has exceeded performance expectations; in a test of its accuracy, 25.4 mm diameter hemispherical aluminium parts were cut to an accuracy of 0.25 μm (size and contour band) with a surface finish of 25–40 nm rms     

A Systematic Approach to Achieving High Performance Hybrid Lighting Phosphors with Excellent Thermal‐ and Photostability

The authors have designed and synthesized a family of high‐performance inorganic–organic hybrid phosphor materials composed of extended and robust networks of one, two, and three dimensions. Following a bottom‐up solution‐based synthetic approach, these structures are constructed by connecting highly emissive Cu₄I₄ cubic clusters via carefully selected ligands that form strong Cu? N bonds. They emit intensive yellow‐orange light with high luminescence quantum efficiency, coupled with large Stokes shift, which greatly reduces self‐absorption. They also demonstrate exceptionally high framework‐ and photostability, comparable to those of commercial phosphors. The high stabilities are the result of significantly enhanced Cu? N bonds, as confirmed by the density functional theory (DFT) binding energy and electron density calculations. Possible emission mechanisms are analyzed based on the results of theoretical calculations and optical experiments. Two‐component white phosphors obtained by blending blue and yellow emitters reach an internal quantum yield as high as 82% and correlated color temperature as low as 2534 K. The performance level of this subfamily exceeds all other types of Cu–I based hybrid systems. The combined advantages make them excellent candidates as alternative rare‐earth element‐free phosphors for possible use in energy‐efficient lighting devices.     

Photoresponse of ZnO Tetrapod Nanocrystal Schottky Diodes

The fabrication of an ultraviolet photodiode employing a single ZnO tetrapod nanocrystal is reported. We have attached two tungsten leads and one platinum lead to three of the arms of the tetrapod. By measuring the transport properties between each pair of leads we show that the tungsten contacts are ohmic and the platinum contacts are rectifying. Photoresponse measurements were carried out with above and below band gap illumination. We observe a much larger ultraviolet photoresponse for the rectifying Pt-ZnO-W junction than the linear W-ZnO-W junction. We conclude that the enhanced photoresponse of our rectifying junction results from a photoinduced reduction of the Schottky barrier height at the Pt-ZnO interface.