-A rope breaks. A bell chimes. A man dies.- The kwispel: a neglected international narrative riddle genre.

Retoric

Flat-plate solar array project. Volume 5: Process development

The goal of the Process Development Area, as part of the Flat-Plate Solar Array (FSA) Project, was to develop and demonstrate solar cell fabrication and module assembly process technologies required to meet the cost, lifetime, production capacity, and performance goals of the FSA Project. R&D efforts expended by Government, Industry, and Universities in developing processes capable of meeting the projects goals during volume production conditions are summarized. The cost goals allocated for processing were demonstrated by small volume quantities that were extrapolated by cost analysis to large volume production. To provide proper focus and coverage of the process development effort, four separate technology sections are discussed: surface preparation, junction formation, metallization, and module assembly

The South African Phillips Curve: How Applicable is the Gordon Model?

Is there a Phillips curve relationship present in South Africa and if so, what form does it take? Traditionally the way to estimate the Phillips curve is merely to regress the change in the price level on a measure of the output gap (or the deviation of actual unemployment from the NAIRU). However, Gordon (1990:481-5) has argued that estimating the Phillips curve in this manner biases the estimated results. Instead, Gordon (1997; 1989) puts forward his so-called triangular model that controls for inertia effects, output level effects and rates-of-change (in output) effects. He applies the model to several European countries, the US and Japan and finds meaningful results. The question this paper poses is whether or not the triangular model also applies to South Africa. In estimating the Phillips curve for South Africa the paper also experiments with four versions of the output gap, based on four different methods to estimate long run output, including the standard Hodrick-Prescott (HP) filter and the production function approach. There are several variants of the Phillips curve. The first, as estimated by Phillips (1958) himself, measures the relationship between wage inflation and unemployment. However, other versions consider the relationship between price inflation and unemployment or price inflation and output. This paper focuses on the latter, given the absence of quarterly unemployment data in South Africa, as well as the lack of a reliable and sufficiently long unemployment time series. The paper first presents an overview of literature on the Phillips curve and its estimation for South Africa and other countries. This is followed by the second section that considers the model to be estimated, the data as well as the discussion of the alternative measures of the output gap. The third section presents the estimated results followed by section four that contains the conclusion and a discussion of the policy implications.

Global optimization of complex optical structures using Baysian optimization based on Gaussian processes

Numerical simulation of complex optical structures enables their optimization with respect to specific objectives. Often, optimization is done by multiple successive parameter scans, which are time consuming and computationally expensive. We employ here Bayesian optimization with Gaussian processes in order to automatize and speed up the optimization process. As a toy example, we demonstrate optimization of the shape of a free-form reflective meta surface such that it diffracts light into a specific diffraction order. For this example, we compare the performance of six different Bayesian optimization approaches with various acquisition functions and various kernels of the Gaussian process.Comment: Proceedings article, SPIE conference "Digital Optical Technologies 2017

Evolution of a coherent array of Bose-Einstein Condensates in a magnetic trap

We investigate the evolution process of the interference pattern for a coherent array of Bose-Einstein condensates in a magnetic trap after the optical lattices are switched off. It is shown that there is a decay and revival of the density oscillation for the condensates confined in the magnetic trap. We find that, due to the confinement of the magnetic trap, the interference effect is much stronger than that of the experiment induced by Pedri et al. (Phys. Rev. Lett, {\bf 87}, 220401), where the magnetic trap is switched off too. The interaction correction to the interference effect is also discussed for the density distribution of the central peak.Comment: RevTex, 17 pages,9 figures. E-mail: [email protected]

Ability of new durum wheat pure lines to meet yield stability and quality requirements in low input and organic systems

Low-input production schemes adopted in organic or conventional farms require crop varieties that combine good product quality and high yield stability under non optimal environmental conditions (Gooding et al., 1999). These traits are not yet found among the durum wheat genotypes available in France. Consequently the cultivation of this crop is hardly successful in stockless organic farms in southern France, which are characterised by very low nitrogen resources. Some hopes emerged with the identification of new durum wheat pure lines with a high grain protein content in breeding experiments conducted near Montpellier in 2001 and 2002. The aim of the present work was to confirm and elucidate the origin of the enhanced protein performance of these new lines through a field experiment with nitrogen resources ranging from very low to sub-optimal levels

The mineralization of commercial organic fertilizers at 8°C temperature

In organic production only organic fertilizers and soil conditioners can be used to supply the soil with nitrogen. The mineralization of these products is slow and so there can be problems with the supply of nitrogen, when the demand of the plants is high. The supply of nitrogen from organic products depends on the speed of their mineralization which is primarily influenced by the composition and formulation of their raw material. In apple production in the Alps-region especially during spring problems with nitrogen supply are common. In that period, the weather conditions are sometimes bad, the temperature in the soil is low and mineralization starts slowly - apple trees demand more nitrogen than the soil can deliver. To compensate the demand of the apple tree organic growers can not use mineral fertilizers but only organic fertilizers and soil conditioners whose mineralization rate is often unknown. There is a strong need in organic fruit production to receive more information about the behaviour of fertilizers in the soil especially concerning their N-release under different conditions. To acquire that information, incubation experiments under controlled conditions (temperature, type of soil, humidity of the soil) were carried out in the laboratory to determine the mineralization-rate of different organic fertilizers and soil conditioners which are available in our region

Quasi 2D Bose-Einstein condensation in an optical lattice

We study the phase transition of a gas of Rb atoms to quantum degeneracy in the combined potential of a harmonically confining magnetic trap and the periodic potential of an optical lattice. For high optical lattice potentials we observe a significant change in the temperature dependency of the population of the ground state of the system. The experimental results are explained by the subsequent formation of quasi 2D condensates in the single lattice sites.Comment: 7 pages (including 3 figures