Using micro-fabrication techniques, we have manufactured a single element kinoform lens in single-crystal silicon with an elliptical profile for 12.398 keV (1A) x-rays. By fabricating a lens that is optimized at fixed wavelengths, absorption in the lens material can be significantly reduced by removing 2_ phase-shifting regions. This permits short focal length devices to be fabricated with smal...

Since most available micro x-ray fluorescence (micro-XRF) spectrometers operate in air, which does not allow the analysis of low-Z elements (Z or = 6). It offers improved excitation and detection conditions necessary for light element analysis. To eliminate absorption of the ...

A new finite element method for the efficient discretization of elliptic homogenization problems is proposed. These problems, characterized by data varying over a wide range of scales cannot be easily solved by classical numerical methods that need mesh resolution down to the finest scales and multiscale methods capable of capturing the large scale components of the solution on macroscopic mesh...

Computational modeling of the structural behavior of continuous fiber composite materials often takes into account the periodicity of the underlying micro-structure. A well established method dealing with the structural behavior of periodic micro-structures is the socalled Asymptotic Expansion Homogenization (AEH). By considering a periodic perturbation of the material displacement, scale bridg...

Introduction: Micro-perforated absorbents are one of the structures that are widely used nowadays. The sound absorption mechanism is performed by viscous energy losses in the cavities on the plate. In this study, the acoustic properties of non-flat perforated panels in oblique angle was investigated in numerical method. Material and Methods: This paper examined the effect of the surface shape ...

One important question for less invasive surgical techniques, such as laparoscopy, is the behavior of the tissue of interest. Non-destructive approaches to determine material properties are of particular benefit. This paper considers the material properties of lamb liver via spherical indentation and finite element analysis. The indentation is performed under a series of step loads with a non c...

The finite element method is used for modeling of self-positioning microand nanostructures. The geometrically nonlinear problem with large rotations and large displacements is solved using step procedure with coordinate updating after each step. It is shown that the real shape of self-positioning structures is rather complicated and the analytical formulas have limited applicability in the esti...

Diarrhoea is acute when increased number of stools persists for less than 2 weeks. Although often mild, acute diarrhea can lead to severe dehydration as a result of large fluid and electrolyte losses. Macro and micro nutrient deficiency is rare. Management is with replacement of fluids and electrolytes (oral or parenteral) to prevent dehydration. Milk and dairy products is best avoided for 24 t...

Knowledge is limited about whether root nutrient concentrations are affected by mixtures of tree species and interspecific root competition. The goal of this field study was to investigate root nutrient element concentrations in relation to root and ectomycorrhizal (EM) diversity in six different mixtures of beech (Fagus sylvatica), ash (Fraxinus excelsior) and lime (Tilia sp.) in an old-growth...