Herleitung und Validierung eines einfachen Modells zur Beschreibung des Misch- und Entmischungsprozesses beim Feststoffmischen

Discontinuous solids mixing processes are largely carried out over the mixing time. The required mixing time is often determined separately in mixing tests. It remains to be seen whether this corresponds to the optimum. There is a lack of models to describe the mixing quality curve over time. The present article adds a simple, two-parameter model that considers not only the homogenization but also the segregation process. In this way, possible mixing quality optima can be approximated with the help of fewer mixing tests that have been carried out.     

On the complexity of bandwidth allocation in radio networks

We define and study an optimization problem that is motivated by bandwidth allocation in radio networks. Because radio transmissions are subject to interference constraints in radio networks, physical space is a common resource that the nodes have to share in such a way, that concurrent transmissions do not interfere. The bandwidth allocation problem we study under these constraints is the following. Given bandwidth (traffic) demands between the nodes of the network, the objective is to schedule the radio transmissions in such a way that the traffic demands are satisfied. The problem is similar to a multicommodity flow problem, where the capacity constraints are replaced by the more complex notion of non-interfering transmissions. We provide a formal specification of the problem that we call round weighting  . By modeling non-interfering radio transmissions as independent sets, we relate the complexity of round weighting to the complexity of various independent set problems (e.g. maximum weight independent set, vertex coloring, fractional coloring). From this relation, we deduce that in general, round weighting is hard to approximate within n^1−ε$n^{1-\epsilon }$ (n$n$ being the size of the radio network). We also provide polynomial (exact or approximation) algorithms e.g. in the following two cases: (a) when the interference constraints are specific (for instance for a network whose vertices belong to the Euclidean space), or (b) when the traffic demands are directed towards a unique node in the network (also called gathering, analogous to single commodity flow).     

Zeolite based trace humidity sensor for high temperature applications in hydrogen atmosphere

We present a humidity sensor based on H-ZSM-5 type zeolite that is suitable to detect traces of humidity (10–110 ppm_V) under harsh conditions, e.g. reducing atmosphere (H₂) and high temperature (up to 600 °C). By means of complex impedance spectroscopy (IS) we show that the zeolite sensor responds linearly towards minimal changes in humidity. Therefore this result indicates that the zeolite sensor is capable to detect traces of humidity in processes where high temperatures in a hydrogen environment are required.     

Entwicklung Serviceorientierter Architekturen zur Integration von Produktion und Dienstleistung – Eine Konzeptionsmethode und ihre Anwendung am Beispiel des Recyclings elektronischer Geräte

Offering product-service bundles (consisting of products and services) is becoming more important for companies. Modifying the organizational structure of the cooperation as well as adapting to changing customer demands requires versatile information systems. Implementing Service Oriented Architectures (SOA) is one attempt to provide this flexibility. Currently, there is little methodical guidance for the identification, specification and implementation of services as building blocks of Service Oriented Architectures. Accounting for this need, a conceptual approach is designed, which adapts approaches of customer integration, and combines a business and IT analysis. The applicability of the method is demonstrated by designing a Service Oriented Architecture for the recycling of electronic equipment. Implementing services for other product-service bundles will support additional integration scenarios. By standardizing services, a sound integration of products and services can be backed by providing a reference architecture.     

从过程价值的角度出发对集成的客户方案进行定价

Integrating products and services to customized solutions can help firms to differentiate from their competitors. In practice, however, various companies fall short in extracting value from their customers. Therefore this paper focuses on pricing aspects as central means for value appropriation in the context of solutions. Following the resource-based view of the firm, we adopt a process-oriented perspective on pricing practices in order to identify crucial factors and activities. Based on 15 in-depth interviews with practitioners from various industries we derive six steps of a price management process for value appropriation in the context of solution selling and present critical activities and routines within each step.     

BerlinMOD: a benchmark for moving object databases

This document presents a method to design scalable and representative moving object data (MOD) and two sets of queries for benchmarking spatio-temporal DBMS. Instead of programming a dedicated generator software, we use the existing Secondo DBMS to create benchmark data. The benchmark is based on a simulation scenario, where the positions of a sample of vehicles are observed for an arbitrary period of time within the street network of Berlin. We demonstrate the data generator’s extensibility by showing how to achieve more natural movement generation patterns, and how to disturb the vehicles’ positions to create noisy data. As an application and for reference, we also present first benchmarking results for the Secondo DBMS. Whereas the benchmark focuses on range queries, we demonstrate its ability to incorporate new future classes of queries by presenting a preliminary extension handling various nearest neighbour queries. Such a benchmark is useful in several ways: It provides well-defined data sets and queries for experimental evaluations; it simplifies experimental repeatability; it emphasizes the development of complete systems; it points out weaknesses in existing systems motivating further research. Moreover, the BerlinMOD benchmark allows one to compare different representations of the same moving objects.     

Scenario analysis and management options for sustainable river basin management: Application of the Elbe DSS

We developed a decision support system (DSS) for sustainable river basin management in the German Elbe catchment (～100,000 km²), called Elbe-DSS. The system integrates georeferenced simulation models and related data sets with a user friendly interface and includes a library function. Design and content of the DSS have been developed in close cooperation with end users and stakeholders. The user can evaluate effectiveness of management actions like reforestation, improvement of treatment plant technology or the application of buffer strips under the influence of external constraints on climate, demographic and agro-economic changes to meet water management objectives such as water quality standards and discharge control. The paper (i) describes the conceptual design of the Elbe-DSS, (ii) demonstrates the applicability of the integrated catchment model by running three different management options for phosphate discharge reduction (reforestation, erosion control and ecological-farming) under the assumption of regional climate change based on IPCC scenarios, (iii) evaluates the effectiveness of the management options, and (iv) provides some lessons for the DSS-development in similar settings. The georeferenced approach allows the identification of local inputs in sub-catchments and their impact on the overall water quality, which helps the user to prioritize his management actions in terms of spatial distribution and effectiveness.     

Precise selective deposition of microparticles on electrodes of microelectronic chips

We examined the high precision deposition of toner and polymer microparticles with a typical size of approximately 10 microm on electrode arrays with electrodes of 100 microm and below using custom-made microelectronic chips. Selective desorption of redundant particles was employed to obtain a given particle pattern from preadsorbed particle layers. Microparticle desorption was regulated by dielectrophoretic attracting forces generated by individual pixel electrodes, tangential detaching forces of an air flow, and adhesion forces on the microchip surface. A theoretical consideration of the acting forces showed that without pixel voltage, the tangential force applied for particle detachment exceeded the particle adhesion force. When the pixel voltage was switched on, however, the sum of attracting forces was larger than the tangential detaching force, which was crucial for desorption efficiency. In our experiments, appropriately large dielectrophoretic forces were achieved by applying high voltages of up to 100 V on the pixel electrodes. In addition, electrode geometries on the chip's surface as well as particle size influenced the desorption quality. We further demonstrated the compatibility of this procedure to complementary metal oxide semiconductor chip technology, which should allow for an easy technical implementation with respect to high-resolution microparticle deposition.     

Multifunctional Gadolinium‐Doped Mesoporous TiO2 Nanobeads: Photoluminescence,Enhanced Spin Relaxation,and Reactive Oxygen Species Photogeneration,Beneficial for Cancer Diagnosis and Treatment

Materials with controllable multifunctional abilities for optical imaging (OI) and magnetic resonant imaging (MRI) that also can be used in photodynamic therapy are very interesting for future applications. Mesoporous TiO₂ sub‐micrometer particles are doped with gadolinium to improve photoluminescence functionality and spin relaxation for MRI, with the added benefit of enhanced generation of reactive oxygen species (ROS). The Gd‐doped TiO₂ exhibits red emission at 637 nm that is beneficial for OI and significantly improves MRI relaxation times, with a beneficial decrease in spin–lattice and spin–spin relaxation times. Density functional theory calculations show that Gd³⁺ ions introduce impurity energy levels inside the bandgap of anatase TiO₂, and also create dipoles that are beneficial for charge separation and decreased electron–hole recombination in the doped lattice. The Gd‐doped TiO₂ nanobeads (NBs) show enhanced ability for ROS monitored via ^?OH radical photogeneration, in comparison with undoped TiO₂ nanobeads and TiO₂ P25, for Gd‐doping up to 10%. Cellular internalization and biocompatibility of TiO₂@x Gd NBs are tested in vitro on MG‐63 human osteosarcoma cells, showing full biocompatibility. After photoactivation of the particles, anticancer trace by means of ROS photogeneration is observed just after 3 min irradiation.