Influence of the Impaction Angle on the Triboelectric Charging of Aerosol Nanoparticles

A low pressure impactor is used to measure triboelectric charging behavior of metallic nanoparticles. Ag nanoparticles, produced by spark discharge, were impacted onto Pt sputtered targets. The influence of the impaction angle and impaction velocity on the triboelectric charging was investigated. While for perpendicular impaction the charge transfer behavior of previous work was confirmed, the oblique impaction revealed new phenomena. Additional charge transfer was observable, which increases with obliqueness. The possibility of mass transfer between particle and target due to the high-energy collisions was also investigated. SEM characterization and Auger spectroscopy indicate mass transfer from the particle to the target surface.     

Cardiac- versus diaphragm-based respiratory navigation for proton spectroscopy of the heart

Magnetic Resonance Materials in Physics, Biology and Medicine - To study inter-individual differences of the relation between diaphragm and heart motion, the objective of the present study was to...     

High‐Affinity Carbohydrate Binding by Trimeric Benzoboroxoles Measured on Carbohydrate Arrays

Carbohydrates are involved in a wide range of biological processes of pharmaceutical relevance. The selective recognition of carbohydrates is therefore of great interest in biology and medicine. In this study we present the synthesis of fluorescent multimeric benzoboroxoles and the analysis of multivalent binding processes to immobilized carbohydrate arrays by fluorescence spectroscopy. We observed high binding affinities of trimeric benzoboroxoles by determination of K_Dsurf values for their interaction with α‐Gal on glass chips. The observed K_Dsurf values were in the mid‐nM range (49 and 104 nM ) and are comparable to the K_Dsurf values for binding of natural lectins, such as that of ConA to immobilized α‐Man (79 nM ). The array technology was found to be an excellent tool for studying the binding processes of multivalent lectin mimetics with respect to profiling and quantitation.     

Alpha‐Synuclein Binds to the Inner Membrane of Mitochondria in an α‐Helical Conformation

The human alpha‐Synuclein (αS) protein is of significant interest because of its association with Parkinson's disease and related neurodegenerative disorders. The intrinsically disordered protein (140 amino acids) is characterized by the absence of a well‐defined structure in solution. It displays remarkable conformational flexibility upon macromolecular interactions, and can associate with mitochondrial membranes. Site‐directed spin‐labeling in combination with electron paramagnetic resonance spectroscopy enabled us to study the local binding properties of αS on artificial membranes (mimicking the inner and outer mitochondrial membranes), and to evaluate the importance of cardiolipin in this interaction. With pulsed, twofrequency, double‐electron electron paramagnetic resonance (DEER) approaches, we examined, to the best of our knowledge for the first time, the conformation of αS bound to isolated mitochondria.     

Microbial community structure in activated sludge floc analysed by fluorescence in situ hybridization and its relation to floc stability

The efficiency of activated sludge treatment plants is dependent on the solid-liquid separation properties of the activated sludge. A critical parameter is the stability of the microbial flocs. Weak flocs deflocculate easily leaving increased concentrations of suspended solids in the effluent. The knowledge about how different bacteria are attached to the flocs and their influence on the bioflocculation is limited. In this study, the deflocculation of different phylogenetic groups of bacteria in activated sludge from a full scale plant was investigated. The experiments were carried out by using a shear method where the sludge flocs are deflocculated under controlled shear conditions. The degree of deflocculation was measured as increase in turbidity of the supernatant. Identification and quantification of the microbial community structure of both total activated sludge and deflocculated bacteria were conducted with group-specific gene probes for broad groups of bacteria (Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and Actinobacteria) and fluorescence in situ hybridization (FISH). The microbial community structure of the deflocculated bacteria was different compared to the total activated sludge with a higher abundance of Gammaproteobacteria in the supernatant indicating that different groups of bacteria are bound with different strength to the floc surface. The results show that the bacteria in the outer parts of the flocs are relatively loosely bound to the floc matrix and can be easily eroded from the surface when exposed to shear.     

Development of a predictive simulation method for thin flash generation in flashless precision forging processes of aluminum parts using FEA and experiments

In this paper, the investigation of thin flash generation in precision forging process of an aluminum long flat part is described. The aim was to derive a predictive simulation method for thin flash generation in order to increase both process and part quality in the future. The forging processes were varied by use of different preforms with equal volumes but different mass distributions while using the same final part geometry. The experimentally forged parts were analyzed concerning the amount and part area of the generated thin flash. The conducted FE simulations were analyzed concerning the hydrostatic pressure values p in the part areas near to the tool gap between upper and lower die immediately before form-filling. For a more detailed comparison, single p values were included to hydrostatic pressure functions P. The comparison between the P functions and the experimentally determined thin flash height shows, that high pressure values as well as high gradients of the P functions indicate less thin flash generation. The method therefore allows a qualitative prediction of thin flash generation. It can provide two kind of information. First: The prediction of the specific locations where thin flash is likely to occur in one final part by use of one single preform. Second: The qualitative prediction of the specific final part areas were thin flash is likely to occur depending on different preform geometries. This method will decreases the necessity of time-consuming forging trials and can shorten the preform designing process in the future.     

Fostering Creativity in New Product Development through Entrepreneurial Decision Making

Research has emphasized the importance of employees' individual entrepreneurial decision making for innovation. In this context, practised creativity as the ability to perceive and exploit creative opportunities, can be regarded as a crucial requirement for employees in new product development. We discuss the application of decision making logic as an important antecedent of practised creativity in new product development. We survey 219 employees from new product development departments of German product and service firms. Results indicate that the use of entrepreneurial decision making logic positively impacts practised creativity; comparably we find indicators that the use of causal decision making logic negatively influences creativity. The effects significantly depend on the moderating role of uncertainty. The results contribute to the literature of creativity, entrepreneurship and new product development by theoretically and empirically revealing effectuation as antecedent to practised creativity. The results open promising avenues for future research and allow the derivation of valuable guidelines for practitioners. Aligning the new product development process to support employees' entrepreneurial decision making may help generating practised creativity.     

Enhancing the efficiency of alternating current driven organic light-emitting devices by optimizing the operation frequency

We report efficient and bright organic light-emitting devices operated by capacitive energy coupling. In this approach, the organic layers are enclosed between sputter-deposited hafnium dioxide layers to prevent charge carrier injection. When a sinusoidal voltage signal is applied to the electrodes, the devices emit bright green light whereas no detectable emission is generated upon application of a constant voltage. The efficiency of the process depends heavily on the frequency of the applied voltage signal. By optimizing the driving scheme, a record luminous efficacy for AC driven OLEDs of 2.7 lm/W at 500 cd/m² is achieved.