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Comparison of vector finite-difference techniques for modal analysis

We compare a vector finite-difference method that correctly applies the boundary conditions at both horizontal and vertical dielectric interfaces (but not at corners or slanted interfaces) to algorithms that only approximately satisfy these boundary conditions. We find, rather unexpectedly, that for strongly guiding waveguides the boundary conditions imposed at the refractive- index discontinuitie

Increased solar energy and daylight utilisation using anti-reflective coatings in energy-efficient windows

Glass with low-a coatings based on SnO2 (usually referred to as hard coatings) provides a cost-effective replacement of one of the panes in ordinary double-pane windows. It considerably improves the energy efficiency of the window and at the same time preserves the appearance of,old hand-crafted windows. Adding a low refractive index anti-reflective (AR) coating on both sides of the low-a coated p

Pretreatment of Lignocellulosic Materials for Efficient Bioethanol Production

Second-generation bioethanol produced from various lignocellulosic materials, such as wood, agricultural or forest residues, has the potential to be a valuable substitute for, or a complement to, gasoline. One of the crucial steps in the ethanol production is the hydrolysis of the hemicellulose and cellulose to monomer sugars. The most promising method for hydrolysis of cellulose to glucose is by

Golv på mark

I denna skrift ges en heltäckande beskrivning av de byggnadsfysikaliska förhållandena i konstruktioner med golv på mark. Olika fuktbelastningar och deras konsekvenser beskrivs i detalj. Stor vikt läggs vid att skapa förståelse för olika byggnadsfysikaliska samband, speciellt mellan värme och fukt. Vidare tillämpas fuktdimensioneringsmetodiken på tre noggrant beskrivna grundkonstruktioner

Cycle-To-Cycle Variations in S.I. Engines--The Effects of Fluid Flow and Gas Composition in the Vicinity of the Spark Plug on Early Combustion

Simultaneous measurements of early flame speed and local measurements of the major parameters controlling the process are presented. The early flame growth rate was captured with heat release analysis of the cylinder pressure. The local concentration of fuel or residual gas were measured with laser induced fluorescence (LIF) on isooctane/3-pentanone or water. Local velocity measurements were perfo

Development of tolerance against toxic cyanobacteria in Daphnia

We tested whether previous exposure to a toxic strain of cyanobacteria (Microcystis) affects survival, growth, and reproduction of a common herbivore, Daphnia magna. Samples from three natural populations of D. magna were each divided into two parts; one part was fed a mixture of toxic Microcystis and the non-toxic green alga Scenedesmus whereas the other part was fed only Scenedesmus. After four

Approximation numbers = singular values

This paper introduces a generalisation of the notion of singular value for Hilbert space operators to more general Banach spaces. It is shown that for a simple integral operator of Hardy type the singular values are the eigenvalues of a non-linear Sturm-Liouville equation and coincide with the approximation numbers of the operator. Finally, asymptotic formulas for the singular numbers are deduced.

Frataxin deficiency in pancreatic islets causes diabetes due to loss of beta cell mass

Diabetes is caused by an absolute (type 1) or relative (type 2) deficiency of insulin-producing beta cells. We have disrupted expression of the mitochondrial protein frataxin selectively in pancreatic beta cells. Mice were born healthy but subsequently developed impaired glucose tolerance progressing to overt diabetes mellitus. These observations were explained by impairment of insulin secretion d

Colour preferences influences odour learning in the hawkmoth, Macroglossum stellatarum

The hummingbird hawkmoth, Macroglossum stellatarum, learns colour fast and reliably. It has earlier been shown to spontaneously feed from odourless artificial flowers. Now, we have studied odour learning. The moths were trained to discriminate feeders of the same colour but marked with different odours. They did not learn to discriminate two natural flower odours when they were presented with the

Two-stage steam pretreatment of willow for increased pentose yield

A two-stage procedure for pretreatment of fast-growing willow with steam has been investigated. The first stage was performed at temperatures in the range 180°C to 220°C for times between 6 and 10 minutes while the second stage was performed at 220°C for 10 minutes. The fibrous material was washed between the two stages to remove the pentosans and thus increase the pentose yield. The pretreatment

Ramadan in Java : The Joy and Jihad of Ritual Fasting

Popular Abstract in Swedish Att fasta under ramadan är både en glädje och ett jihad för det muslimska samfundet i Java, och fastan är utan tvekan den mest aktade ritualen i det muslimska Indonesien (och på andra håll i den muslimska världen). Att avhålla sig från mat, dryck och sexuella relationer från gryning till skymning i en hel månad i ett tropiskt klimat - och att fylla nätterna med extra frFASTING DURING THE holy month of Ramadan is both a joy and a jihad for the Islamic community in Java, and it is arguably the most highly esteemed Muslim ritual in Indonesia (and beyond). To be given the opportunity to abstain from food, drink and sexual relations from the early morning hours until sunset during an entire month in a tropical climate - only to fill the nights with additional and sup

Multi-plume aerosol dynamics and transport model for urban scale particle pollution

The Multi-plume Aerosol dynamics and Transport (MAT) model has been developed to study the dynamics of the particle size distribution in urban environments. The MAT model uses a novel multi-plume scheme for vertical dispersion and routines of the aerodynamics models AERO3. It treats the processes: emission from a near ground source, dilution with background air, deposition, coagulation and condens