It is internationally recognized that validation is necessary in analytical laboratories. The use of validated methods is important for an analytical laboratory to show its qualification and competency. This work describes the methods for validation of gamma spectrometric analytical procedure in the determination of some gamma emitters in environmental samples. The method was tested and validat...

Institut für Geowissenschaften, Abt. Kristallographie, Johann Wolfgang Goethe-Universität Frankfurt, Senckenberganlage 30, D-60325 Frankfurt a.M., Germany, Institut für Geowissenschaften, Mineralogie, Kristallographie, Christian-Albrechts-Universität zu Kiel, Olshausenstraße 40, D-24098 Kiel, Germany, Department Chemie und Biochemie, Lehrstuhl für Anorganische Festkörperchemie, LudwigMaximilian...

The unsustainable harvest of wildlife is a major threat to global biodiversity and to the millions of people who depend on wildlife for food and income. Past research has called attention to the fact that commonly used methods to evaluate the sustainability of wildlife hunting perform poorly, yet these methods remain in popular use today. Here, we conduct a systematic review of empirical sustai...

Analytical ultracentrifugation experiments can be accurately modeled with the Lamm equation to obtain sedimentation and diffusion coefficients of the solute. Existing finite element methods for such models can cause artifactual oscillations in the solution close to the endpoints of the concentration gradient, or fail altogether, especially for cases where somega(2)/D is large. Such failures can...

Sedimentation velocity analysis is a powerful tool for the investigation of biological macromolecules under a wide range of solution conditions. If carefully applied, it can be an effective tool for the characterization of interacting systems in solution. It is rapidly becoming a method of choice among the biotechnology community. In recent years, there have been notable advances in the ease of...

Dielectrophoresis is a non-destructive, label-free method to manipulate and separate (bio-) particles and macromolecules. The mechanism is based on the movement of polarizable objects in an inhomogeneous electric field. Here, microfluidic devices are reviewed that generate those inhomogeneous electric fields with insulating posts or constrictions, an approach called electrodeless or insulator-b...

This paper deals with a three-dimensional numerical procedure based on the finite-element method for the modeling of finite-amplitude progressive acoustic waves. The method can predict the nonlinear propagation of acoustic fields produced by sources of arbitrary geometry. Based upon a perturbation method, a second-order analytical study is developed and the numerical procedure is formulated. Ba...

In this paper, we develop two computational models for the electrical performance of the tubular solid oxide fuel cell designed by Siemens Westinghouse Corporation. The first model makes simplifying assumptions for activation and concentration polarizations and obtains an analytical solution. In the second procedure, we allow the polarizations to vary with the current density and solve the equa...