混合粉的弃模能力

粉末冶金混合粉的质量常用标准技术，如霍尔流动性、松装密度等进行研究。可是这些技术在预测生产性能上是有限的。为此，开发出一种充模模拟器。表征矩形模的填充以确立模宽与取向对混合粉填充密度的重要性。而且研究了混合粉的粘对对充模的影响，特别是在进料靴的最大可能速度下进行研究。根据压制中对填充性能的影响，对结果进行了讨论。     

Role of cation exchange processes on the sorption influenced transport of cationic β-blockers in aquifer sediments

The influence of cation exchange processes on the transport behavior of the cationic β-blockers atenolol and metoprolol was investigated by applying saturated laboratory column experiments. Breakthrough curves using natural sediments under different competitive conditions were generated and resulting sorption coefficients were compared. For the cationic species of atenolol (at pH = 8), the existence and dominating role of cation exchange processes were demonstrated by varying calcium concentrations. No effect of atenolol concentration on its retardation was observed within a wide concentration range. The breakthrough curve comparison of atenolol and the more hydrophobic metoprolol under constant conditions showed a significantly stronger retardation for metoprolol than for atenolol. However, additional non-polar interactions cannot explain the observed differences as they are determined to be negligible for both compounds. Due to the dominating role of cation exchange processes for the cationic species on overall sorption, a simple prediction of β-blocker transport in the subsurface by using K_OC values derived from log K_OW-log K_OC correlations is not feasible.     

AUTCOMS — Automatisierungstechnik und Computertechnik

Ohne Zusammenfassung     

Safe airport operation based on innovative magnetic detector system

A novel magnetic sensing technology that forms the basis of an innovative system to monitor ground vehicle movements at airports is presented. The operating principle of this system is the detection of interaction of aircraft or ground vehicles with the earth?s magnetic field using sensitive magnetic field detectors. After development and laboratory testing of the detectors, test sites have been set up at three European airports. Potential applications of the detectors were designed and demonstrated. Tests have shown that the system can be applied for ground movement surveillance. The approach can be used as a complementary surveillance system for existing and future advanced surface movement guidance and control systems (A-SMGCS) at large airports or as a cost-effective stand-alone solution for monitoring critical areas at medium and small airports. Furthermore, this system can be applied as well in road traffic and car park occupancy monitoring. Unaffected by weather conditions, interference and shadowing effects, the system provides reliable vehicle position, velocity and direction information without requiring any equipment in aircraft or ground vehicles and thus it increases airport operational safety.     

High-Temperature Mechanical Properties of Si-B-C-N-Precursor-Derived Amorphous Ceramics and the Applicability of Deformation Models Developed for Metallic Glasses

The characterization of Si-B-C-N amorphous ceramics using isothermal compression creep testing in the temperature range of 1200°–1500°C is reported. The deformation rate contains a stress-dependent component that is proportional to the applied stress, which indicates that this portion of the deformation mechanism is based on viscous flow. An increase in the creep resistance is observed, following either preliminary annealing or hot isostatic pressing, which may be explained by a reduction of free volume in the amorphous material. The application of two deformation models that are used to predict similar deformation behavior in metallic glasses also is discussed. Although both models accurately predict the time dependence of the deformation rate of precursor-derived amorphous ceramics, the free-volume model fits the observed temperature dependence better than the "two-step" rearrangement model.     

Forschungscluster „Automatisierungstechnik und Computertechnik“

Ohne Zusammenfassung