1-D profiles and time series from an idealised atmospheric boundary layer model are presented, which show agreement with boundary layer measurements of polar NOx. Diffusion models are increasingly being used as the framework for studying tropospheric air chemistry dynamics. Models based on standard boundary layer diffusivity profiles have an intrinsic behaviour that is not necessarily intuitive...

Aims. We present global 3D MHD simulations of disks of gas and solids, aiming at developing models that can be used to study various scenarios of planet formation and planet-disk interaction in turbulent accretion disks. Methods. We employ the PENCIL CODE, a 3D high-order finite-difference MHD code using Cartesian coordinates. We solve the equations of ideal MHD with a local isothermal equation...

Dissertation zur Erlangung des akademischen Grades Doktor der Naturwissenschaften Introduction Figure 1.1: One possible amorphous silicon (white) and carbon (black) network with incorporated hydrogen (small black dots) a-SiC:H. 20 Figure 1.2: Fourier transformed infrared (FTIR) absorption spectra for a typical stoichiometric SiC layer as deposited at 350°C. 21 Figure 1.3: Auger electron spectro...

In this work heat and mass transfer in tubular asymmetric ceramic membranes suitable for applications in membrane reactors have been investigated. An experimental matrix has been employed to quantify the heat and mass transfer in the membrane, which leads to the identification and validation of respective parameters in a comprehensive and consistent manner. Two types of membranes have been inve...

in the present work, b-zsm-5 zeolite membranes were synthesized on porous tubular α-alumina supports by several subsequence in situ crystallization hydrothermal treatments. the tio2- bohmite and ɣ- alumina intermediate layers were applied to improve the lattice matching between zeolite layer and the support. the uniform membrane intermediate layers with low permeation resistance were prepared o...

Sulfonated polyether ether ketone (SPEEK) is categorized in a nonfluorinated aromatic hydrocarbon proton exchange membrane (PEM) group and considered as a suitable substitute for common per-fluorinated membranes, such as Nafion, due to wider operating temperature, less feed gas crossover, and lower cost. Since modeling results in a better understanding of a phenomenon, in this study a dynamic o...

The reaction kinetics for the formation of CuInSe2 thin films from a stacked bilayer precursor consisting of InSe and CuSe was studied by means of in situ high-temperature x-ray diffraction. In particular, the isothermal phase evolution of the glass/InSe/CuSe precursor was observed at different temperatures. The pathway produces a CuInSe2 diffusion barrier layer that also functions as a nucleat...

Solid oxide fuel cell (SOFC) is a promising alternative energy source, with its advantages of high operating efficiency, fuel flexibility, low emissions and relatively low cost. However, there are several challenges concerning the SOFC research. Little is known about the complex interfacial electrochemistry and thermochemistry, and it is also difficult to diagnose problems and optimize cell per...