Electromagnetic simulation of bonding wires and comparison withwide band measurements

Several typical bonding wire configurations have been measured in a frequency range up to 20 GHz using a vector network analyzer. Based on scanning electron microscope (SEM) pictures all bonding wires have been discretized and orthogonal grids suitable for electromagnetic simulation have been generated. Full wave finite difference time domain (FDTD) simulations as well as static and quasi static inductance extraction using a new Monte Carlo technique and FastHenry as well as capacitance extraction with a finite element method have been carried out. Numerical results are compared to measured scattering parameters and their quality and frequency dependence is discussed. All simulation techniques are evaluated with respect to their computational effort     

Loss of Interleukin-13-Receptor-Alpha-1 Induces Apoptosis and Promotes EMT in Pancreatic Cancer

In search of new therapies for pancreatic cancer, cytokine pathways have attracted increasing interest in recent years. Cytokines play a vital role in the crosstalk between tumour cells and the tumour microenvironment. The related inflammatory cytokines IL-4 and IL-13 can regularly be detected at increased levels in the microenvironment of pancreatic cancer. They share a receptor heterodimer consisting of IL-4Rα and IL-13Rα1. While IL-4Rα induces a more oncogenic phenotype, the role of IL-13Rα1 was yet to be determined. ShRNA-based knockdown of IL-13Rα1 was performed in Capan-1 and MIA PaCa-2. We assessed cell growth and migratory capacities under the influence of IL-13Rα1. Pathway alterations were detected by immunoblot analysis. We now have demonstrated that the loss of IL-13Rα1 induces apoptosis in pancreatic cancer cells. This was associated with an epithelial-to-mesenchymal transition. Loss of IL-13Rα1 also abolished the effects of exogenous IL-4 and IL-13 stimulation. Interestingly, in wild type cells, cytokine stimulation caused a similar increase in migratory capacities as after IL-13Rα1 knockdown. Overall, our results indicate the vital role of IL-13Rα1 in the progression of pancreatic cancer. The differential expression of IL-4Rα and IL-13Rα1 has to be taken into account when considering a cytokine-targeted therapy in pancreatic cancer.     

Dressing and truing of hybrid bonded CBN grinding tools using a short-pulsed fibre laser

This paper presents the results of an investigation into the dressing and truing of hybrid bonded (metal-vitrified) CBN grinding wheels using a short-pulsed fibre laser. Truing of complex contours on CBN grinding tools with sharp edges (edge radii of less than 20 μm) could be successfully applied, whereas other dressing methods have been neither technically nor economically successful. Sharpening by laser can provide the same wheel surface topography which is conventionally produced by SiC and/or Al₂O₃ sharpening tools. Grinding characteristics and long-term performance of the laser-profiled tools are discussed.     

Anomalous influence of polarity in sink EDM of titanium alloys

An anodic tool polarity is generally adopted in sink electrical discharge machining (EDM) to maximize material removal relative to tool wear. Sink EDM of Ti and Ti6Al4V is however atypical in that these materials necessitate a cathodic tool polarity. Adding to the intrigue is γ-TiAl, which machines better under the conventional anodic polarity. This research focused on clarifying the phenomena behind this interesting behavior by investigating removal mechanisms over a range of relevant process conditions. The anomaly is demonstrated to arise from the polarity-dependent nature and extent of TiC formation on the work surface, which significantly affects material removal.     

Electrically conductive and optically transparent Sb-doped SnO2 STM-probe for local excitation of electroluminescence

We demonstrate that an optically transparent and electrically conductive antimon-doped tin-oxide tip that is prepared in a sol-gel process can be used as a probe for scanning tunnelling microscopy (STM), yielding atomic vertical and nanometre lateral resolution. Emission of visible light from the tunnelling junction between gold particles and the tip is observed for bias voltages above 7 V. In contrast to the metallic tips generally used in STM, this tip does not significantly perturb the local optical response. Therefore, the tunnelling induced light can be used to map the optical near-field of surface structures with the tunnel gap acting as highly localised light source for the investigation of near-field enhancement in complex metal structures.     

High-Temperature Hall Measurements on BaSnO3Ceramics

Simultaneous Hall and conductivity measurements were performed in situ between 650° and 1050°C on n-type semiconducting BaSnO₃ceramics. The variation of the Hall mobility and the Hall carrier density as a function of oxygen partial pressure between 10² and 10⁵ Pa and of temperature was investigated. At temperatures below 900°C the conductivity exhibits a dependence on temperature and oxygen partial pressure which is mainly determined by variations of the Hall mobility. Above 900°C most of the significant dependence is due to a variation in carrier density. Furthermore, a simple defect model assuming doubly ionized oxygen vacancies and acceptor impurities is discussed for BaSnO₃.     

Effect of Ca and B incorporation into silicon oxycarbide on its microstructure and phase composition

Ca- and/or B-modified silicon oxycarbides were synthesized via pyrolysis of suitable polysilsesquioxane-based single-source precursors. Their polymer-to-ceramic transformation was investigated with thermogravimetric analysis, coupled with in situ evolved gas analysis. The prepared silicon oxycarbides were investigated with respect to their crystallization behavior, network architecture, and chemical compositions. The network connectivity in silicon oxycarbides can be affected/tuned upon using two different “tools”: (a) first, the use of network modifiers, such as Ca in our study, leads to a slight depolymerization of the network via generation of a small amount of Q³ sites; (b) second, the modification of silicon oxycarbide with B/Ca leads to a decrease of the carbon content in the network and thus to a significant decrease of its connectivity. Using these two different effects, the network connectivity in silicon oxycarbides can be finely tuned.     

Density of solutions of formaldehyde in water and alcohols

Formaldehyde is an important chemical that is mostly handled in aqueous solutions, which generally also contain methanol; furthermore, also solutions of formaldehyde in other alcohols are used. The density of these solutions is an important thermophysical property. The available models of the density of formaldehyde-containing solutions, however, all have shortcomings, such as a poor accuracy or a limited range of applicability. Therefore, in the present work, a new model of the density in systems of the type (formaldehyde + water + alcohol) was developed. The alcohols that are presently included in the new model are methanol, 1-propanol, and isoprenol; an extension to other alcohols is straightforward. The model was developed using literature data and extensive new density data measured in this work covering binary, ternary, and quarternary solutions of formaldehyde in water, methanol, 1-propanol, and isoprenol at temperatures of $283-333$ K and formaldehyde concentrations of 0.06 − 0.30 g g⁻¹.     

The development of the German energy market until 2030—A critical survey of selected scenarios

Many scenarios have been generated in the last years analysing the international energy market. The variety of these scenarios is manifold, as they are generated by different institutions using different methodological approaches and different framework assumptions. However, these scenarios can roughly be classified into three main groups: “moderate”, “climate protection” and “resource scarcity and high fossil fuel prices”. Analysing the German energy market makes a fourth scenario group necessary, which considers the possible revision of the decided nuclear energy phase out. Most of the existing scenarios developed by different institutions can be allocated into one of these groups. A representative scenario for each group has been selected to illustrate the development of the energy sector until 2030. Contrary to the worldwide primary energy demand (PED), the German PED decreases in each scenario, even though the drop differs strongly throughout the scenarios. On the other hand the structure of the PED in 2030 varies strongly for each scenario, especially regarding the share of fossil energy sources. However, a common robust result can be observed throughout all scenarios, namely the high increase in the share of the renewable energy resources, although the scenario generation processes are not always robust.