Hagen Schmidt

Learn More
This paper discusses the application of the finite element method to the simulation of surface acoustic wave generation on piezoelectric substrates and the possibility of reducing the number of computations by taking into account the symmetry of the problem. It is shown that the computations can be performed in only one half of the structure provided that(More)
Renal morphogenesis requires a balance between positive and negative signals, which are provided in part by the receptor tyrosine kinase Ret and the putative tumor suppressor Sprouty1, respectively. Tyrosine 1062 of Ret is a binding site for several adaptor and effector proteins, such as Grb2/Sos/Ras, which activate the ERK pathway. Mice lacking Ret(More)
The paper studies, by the finite element method, the reflection of surface acoustic waves from single obstacles of regular shapes on the surface of piezoelectric materials. The so-called perfectly matched layer is used to truncate the computational domain. The following types of imperfections are considered: single steps, grooves, and projections, as well(More)
Differential mobility spectra for alkanes, alcohols, ketones, cycloalkanes, substituted ketones, and substituted benzenes with carbon numbers between 3 and 10 were obtained from gas chromatography-differential mobility spectrometry (GC-DMS) analyses of mixtures in dilute solution. Spectra were produced in a supporting atmosphere of purified air with 0.6-0.8(More)
We have successfully grown high-quality AlN piezoelectric single crystal using the sublimation technique. Transparent crack-free boules of approximately 15 mm in diameter and 25 mm in length along the [0001] direction were obtained, with coloring from amber to dark brown depending on growth temperature. Full sets of material parameters of grown AlN and(More)
The principle, character and developments of the instrument of ion mobility spectrometry are introduced, the applications of IMS to chemical warfare agents, explosives, drugs, environments monitoring and on-site industrial sensing are discussed, and some work on IMS in ISAS is represented.
A numerical study is carried out of the surface acoustic wave generation by a bulk acoustic wave in a half-infinite anisotropic half-space without piezoeffect. The efficient conversion of bulk waves into surface waves occurs due to a grating area created on the surface of the substrate. Our simulations are fully based on the finite element method. Given the(More)
Generating aerosol droplets via the atomization of thin aqueous films with high frequency surface acoustic waves (SAWs) offers several advantages over existing nebulization methods, particularly for pulmonary drug delivery, offering droplet sizes in the 1-5-μm range ideal for effective pulmonary therapy. Nevertheless, the physics underlying SAW atomization(More)
In this paper, we detect and characterize the carbon contamination layers that are formed during the illumination of extreme ultraviolet (EUV) multilayer mirrors. The EUV induced carbon layers were characterized ex situ using spectroscopic ellipsometry (SE) and laser generated surface acoustic waves (LG-SAW). We show that both LG-SAW and SE are very(More)