Luhmann T.,University of Oldenburg
ISPRS Journal of Photogrammetry and Remote Sensing | Year: 2010
This article summarizes recent developments and applications of digital photogrammetry in industrial measurement. Industrial photogrammetry covers a wide field of different practical challenges in terms of specified accuracy, measurement speed, automation, process integration, cost-performance ratio, sensor integration and analysis. On-line and off-line systems are available, offering general purpose systems on the one hand and specific turnkey systems for individual measurement tasks on the other. Verification of accuracy and traceability to standard units with respect to national and international standards is inevitable in industrial practice. System solutions can be divided into the measurement of discrete points, deformations and motions, 6DOF parameters, 3D contours and 3D surfaces. Recent and future developments concentrate on higher dynamic applications, integration of systems into production chains, multi-sensor solutions and still higher accuracy and lower costs. © International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS).
Kaupp G.,University of Oldenburg
CrystEngComm | Year: 2011
A systematic survey over the varied use of milling with metals according to reaction types is presented. After the mechanistic distinction of the brittle milling and ductile kneading also for large-scale industrial processes, the consequences for improved applications are exemplified. This covers milling of metals with infinitely covalent non-metals, with metal salts, molecular crystals and carbon, with metal hydrides, with gases (H2, N2, O2), with semi-metals (As, B, Ge, Se, Si, Te), with organic halides and ketones, and with other metals for mechanical alloying. Homogeneous alloys and nanocomposites are distinguished. Metal-metal mechanical alloying is subdivided under solid solutions of immiscible metals, metal-metal nanocomposites, and intermetallics (crystalline and amorphous). The latter is further subdivided into brittle-brittle, brittle-ductile, and ductile-ductile combinations and followed by superalloy composites. Binary alloys are primarily used for the exemplification in order to limit the already enormous field. Various techniques for the decreasing of unduly long milling times become evident from the mechanistic considerations. Optimal choice of the temperature in heat-controlled mills featuring upgrading and adjustable milling conditions is substantial. This is equally important for milling and for ductile kneading. Essential parameters are the selected temperature and optimal (not maximal) milling impact (for example ball mass, size and speed, ball to powder ratio, chamber filling level) for avoiding clogging or lumping instead of generating the maximal number of collisions. Further tools are cycle operation and semi-continuous processing in closed systems for milling and easy collection under vacuum or with pressurized gases. © 2011 The Royal Society of Chemistry.
Mattes J.,University of Oldenburg
Regional Studies | Year: 2012
Mattes J. Dimensions of proximity and knowledge bases: innovation between spatial and non-spatial factors, Regional Studies. Innovations face the challenge of integrating knowledge from heterogeneous sources by establishing an appropriate level of proximity. Proximity is thereby not a purely spatial phenomenon, but also includes organizational, institutional, social and cognitive dimensions. Geographical and social proximity are thereby auxiliary factors, whereas organizational, institutional and cognitive proximity act as critical enablers for learning. These dimensions can be connected to synthetic, analytical and symbolic knowledge bases. They thereby trigger a dynamic trade-off between various forms of proximity, whereby the proximity form varies depending on the underlying knowledge base. Hence, innovation is a complex combination of spatial and non-spatial factors. © 2012 Copyright Regional Studies Association.
Kunzel S.,University of Oldenburg
Journal of European Social Policy | Year: 2012
Active inclusion reforms are radically transforming social policies in Europe. Consequently, the welfare state is changing from a social citizenship approach based on uniform benefits and services towards a system of individualized, targeted welfare intervention. Reforms therefore involve a fundamental re-organization of welfare provision. This transformation is usually discussed as a matter of national regimes for active inclusion and European diffusion of 'good' governance. However, active inclusion policies rely on a different social policy approach implying differentiated implementation processes. The implementation of active inclusion reforms can therefore only be understood by taking into account the local level. A series of local studies on French and German minimum income schemes raises questions about national accounts of these schemes, which depict a shift towards workfare. By contrast, this article reveals local variation between market-oriented, bureaucratic and participatory active inclusion strategies dependent on the distinct local governance arrangements. © SAGE Publications 2012.
Bormann H.,University of Oldenburg
Climatic Change | Year: 2011
Potential evapotranspiration models very often are important part of hydrological catchment models to calculate potential evapotranspiration (PET) which then is used to estimate actual evapotranspiration considering the soil moisture status. As many different approaches exist, the question arises in which way the choice of the PET model affects the impact of climate change on the calculated water balance? Therefore, 18 different PET models were compared with respect to their sensitivity to observed climate change. Long-term climate data of six German climate stations were used to identify changes in the climate data itself and changes in the calculated PET. The results show that all investigated PET models are sensitive to significant trends in climate data. However, it is also shown that all models show different sensitivities, and that the sensitivities cannot be grouped in terms of different types of PET models such as the aerodynamic concept, radiation or temperature based approaches and combination equations. Predominantly, the variability within a group of models of the same type is comparable to the variability between different model types. Therefore it can be concluded that PET models should be validated in a regional context before they are applied to a certain region within a climate change study despite the poor availability of long-term PET measurements. © 2010 Springer Science+Business Media B.V.