A Rigorous Finite-Element Domain Decomposition Method for Electromagnetic Near Field Simulations

Rigorous computer simulations of propagating electromagnetic fields have become an important tool for optical metrology and design of nanostructured optical components. A vectorial finite element method (FEM) is a good choice for an accurate modeling of complicated geometrical features. However, from a numerical point of view solving the arising system of linear equations is very demanding even for medium sized 3D domains. In numerics, a domain decomposition method is a commonly used strategy to overcome this problem. Within this approach the overall computational domain is split up into smaller domains and interface conditions are used to assure continuity of the electromagnetic field. Unfortunately, standard implementations of the domain decomposition method as developed for electrostatic problems are not appropriate for wave propagation problems. In an earlier paper we therefore proposed a domain decomposition method adapted to electromagnetic field wave propagation problems. In this paper we apply this method to 3D mask simulation.Comment: 9 pages, 7 figures, SPIE conference Advanced Lithography / Optical Microlithography XXI (2008

Seasonality, precautionary savings and health uncertainty: Evidence from farm households in central Kenya

The high prevalence of risks in low income economies makes managing uncertainty critical for productivity and survival. This paper analyzes seasonal changes in farm households’ per capita consumption and saving in response to weather and health shocks. Using a sample of 196 households in central Kenya, it tests the notion that people save most of their transitory income, and examines their precautionary saving motives. The results show that the propensity to save out of transitory income is about a fifth of what the permanent income hypothesis postulates. The propensity to save differs by wealth, with the poor exhibiting stronger precautionary motives towards rainfall variability. But the wealth effect is weak, suggesting that the asset base is vulnerable even for the better-off. However, precautionary savings tend to increase with wealth among HIV/AIDS affected households. Since illness is associated with higher consumption, and therefore less investment, we find more volatile consumption for HIV/AIDS affected households

Monetary expansion and federal open market committee operating strategy in 1971

Federal Open Market Committee ; Monetary policy - United States

Direct comparison of the performance of CZT detectors contacted with various metals

Cadmium Zinc Telluride (CZT) achieves excellent spatial resolution and good energy resolution over the broad energy range from several keV into the MeV energy range. In this paper we present the results of a systematic study of the performance of CZT detectors manufacturered by Orbotech (before IMARAD) depending on surface preparation, contact materials and contact deposition. The standard Orbotech detectors have the dimension of 2.0 x 2.0 x 0.5 cm. They have a pixellated In anode with 8 x 8 pixels and a monolithic In cathode. Using the same CZT substrates several times, we have made a direct comparison of the performance of different contact materials by replacing the cathode and/or the anode contacts with several high-workfunction metals. We present the performance of the detectors and conclude with an overview over our ongoing detector optimization.Comment: 8 pages, 5 figures, to appear in the proceedings of the conference 5922, "Hard X-Ray and Gamma-Ray Detector Physics VII" on the "Optics & Photonics 2005" SPIE Symposium, July 31- August 4, 2005, San Diego, C

JCMmode: An Adaptive Finite Element Solver for the Computation of Leaky Modes

We present our simulation tool JCMmode for calculating propagating modes of an optical waveguide. As ansatz functions we use higher order, vectorial elements (Nedelec elements, edge elements). Further we construct transparent boundary conditions to deal with leaky modes even for problems with inhomogeneous exterior domains as for integrated hollow core Arrow waveguides. We have implemented an error estimator which steers the adaptive mesh refinement. This allows the precise computation of singularities near the metal's corner of a Plasmon-Polariton waveguide even for irregular shaped metal films on a standard personal computer.Comment: 11 page

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