Hagen Schmidt

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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)
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)
In this paper a new tool to assess viscoelastic and dielectric properties of human fluids is presented. Shear horizontal polarized surface acoustic waves (SH-SAW) are used to detect the viscoelastic properties of coagulating blood and blood plasma samples. One-port SAW resonators, with fundamental modes of 85, 170 und 340 MHz were developed. Additionally,(More)
The high-frequency pressure induced by a surface acoustic wave in the fluid filling a microchannel is computed by solving the full scattering problem. The microchannel is fabricated inside a container attached to the top of a piezoelectric substrate where the surface wave propagates. The finite element method is used. The pressure found in this way is(More)
The discrete IGBT (Insulated Gate Bipolar Transistor) is the most important power semiconductor device for power conversion and control in the medium power range with voltages >400 V. Next generation IGBTs require low thermal budget p-n junction formation for the back side field stop and emitter layer. The requirement for the limited thermal budget is(More)
Rccently ion-implantation technique and activation technique are emphasized to enhance the performance of Insulated Gate Bipolar Transistor (IGBT) replacing epitaxial wafers with FZ wafers. In the IGBT's structure, an n-type layer and a p-type layer are introduced into the back side of the wafer at the different depth to form PN junction. The next(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 paper studies by the finite element method the harmonic surface acoustic wave scattering at 90° corners of piezoelectric substrates. The SAW is incident perpendicular to the vertical border. The dependencies of the reflection and transmission coefficient on the radius of the fillet at the corner are found for 128°YX and YZ LiNbO3 as well as ST-X SiO2(More)