Determination of the isentropic turbine efficiency due to adiabatic measurements and the validation of the conditions via a new criterion

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The determination of the isentropic turbine efficiency under adiabatic and SAE boundary conditions is studied in this paper. The study is structured into two parts. The first part describes the possibility of measuring the isentropic turbine efficiency directly. Normally this is not possible in measurements conducted following the SAE J922 guidelines. Therefore, the experiments have been carried out under adiabatic conditions, and combined with improved measuring equipment. The results were compared with adiabatic computational fluid dynamics simulations of this turbocharger. In the second part, a new criterion is defined in order to evaluate the quality of the adiabatic measurements and compare them with standard measurements. The investigation has been carried out with multiple turbochargers ranging from very small to medium passenger car size turbochargers. In the end, a possible application for the criterion is given

Rural cinema in the Saarland region

The article explores the characteristics of rural cinema culture taking the dense cinematic landscape of the Saarland and the village of Wiesbach as an example. As far as primary sources allow, spatial contexts and audiences of cinema screenings will be investigated. It is discussed how the programs were adapted to the specific audience and their taste. The development of distribution networks that were adapted to the lower settlement density of the country, and the proximity of the large city of Saarbrücken, from where the films could quickly be transported to the rural communities, also helped the rural business. In general, attendances declined sharply since the 1960s, but the proportion of young people increased. For several years the rural cinema successfully adjusted to this, until the competition of metropolitan cinema and of television as well as increasing automobility largely forced it to give up. Altogether, from the 1920s to the 1960s, rural cinema contributed to the integration of villages and small towns into the national media landscape. It had a special programme structure, which was influenced by the respective cultural climate and local social control. The cinema building as a place of consumption and as a symbol for an advanced media world contributed to the development of urbanity in the country towns.The article explores the characteristics of rural cinema culture taking the dense cinematic landscape of the Saarland and the village of Wiesbach as an example. As far as primary sources allow, spatial contexts and audiences of cinema screenings will be investigated. It is discussed how the programs were adapted to the specific audience and their taste. The development of distribution networks that were adapted to the lower settlement density of the country, and the proximity of the large city of Saarbrücken, from where the films could quickly be transported to the rural communities, also helped the rural business. In general, attendances declined sharply since the 1960s, but the proportion of young people increased. For several years the rural cinema successfully adjusted to this, until the competition of metropolitan cinema and of television as well as increasing automobility largely forced it to give up. Altogether, from the 1920s to the 1960s, rural cinema contributed to the integration of villages and small towns into the national media landscape. It had a special programme structure, which was influenced by the respective cultural climate and local social control. The cinema building as a place of consumption and as a symbol for an advanced media world contributed to the development of urbanity in the country towns

Entdeckung des Urbanen: Die Sozialforschungsstelle Dortmund und die soziologische Stadtforschung in Deutschland, 1930 bis 1960

Ulrike Kändler: Entdeckung des Urbanen: Die Sozialforschungsstelle Dortmund und die soziologische Stadtforschung in Deutschland, 1930 bis 1960. Bielefeld: transcript 2016. 978383762676

Barriers to the establishment of new key technologies. Summary

Germany is considered innovative and, in a global comparison, excellent in basic research and technology development. Germany is strong in its traditional markets, such as mechanical and vehicle engineering or electrical engineering. However, Germany also has problems when it comes to the rapid and broad implementation of the innovative ideas and results of research and development in concrete applications, especially for the establishment of new, future-oriented key technologies. The diffusion of applications resulting from new key technologies on the market also often confronts companies and entrepreneurs with blockades that are difficult or almost impossible to overcome. Subject and objective of the study The objective of the project "Blockades in the Establishment of New Key Technologies" was to investigate the existing innovation barriers in Germany that block or impede the establishment of new key technologies and the creation of German lead markets or the replacement of traditional export technologies by new key technologies. However, factors that have a particularly beneficial effect should also be identified. On this basis, specific technologies or markets were identified where Germany has not yet exhausted its diffusion and market potential or has been particularly successful in doing so. Finally, by analysing the factors to which these deficits or successes could be attributed, possibilities for political influence were elicited that could contribute to the removal of existing blockades and the promotion of positive factors. The project used a combined approach of a cross-technology innovation system analysis and three technology-specific, in-depth case studies to investigate specific key technologies. The innovation system approach was based on a comprehensive literature and data analysis and provided a research grid for the three case studies. In doing so, the innovation system analysis primarily aimed at capturing and structuring the central inhibiting and facilitating factors, which were specifically investigated and evaluated in the case studies. The case studies selected were Nanoelectronics as a cross-sectional technology, wind energy as an application technology, MP3 players and mini beamers as applications and product innovations respectively. Within the framework of these case studies, several expert interviews were conducted with relevant stakeholders in each case, as well as a workshop in the German Bundestag in Berlin with representatives from science, business and politics. The results of the three case studies were harmonised via the research grid in order to finally compare the identified blockages and derived measures or options for action on a generalised basis. In doing so, blockades were related to suitable measures and possible contributions for involved actors were identified, by means of which the dismantling of existing blockades and the establishment of new key technologies could be supported

In-Flight Reconfiguration with System-On-Module Based Architectures for Science Instruments on Nanosatellites

For science payloads on nanosatellite missions, there is a great interest in cost-effective, reliable and state-of-the-art computing performance. Highly integrated system architectures combine reconfigurable System-on-Chip (SoC) devices, memory and peripheral interfaces in a single System-on-Module (SoM) and offer low resource requirements regarding power and mass, but moderate to high processing power capabilities. The major advantages of these architectures are flexibility, (re)programmability, modularity and module reuse. However, it is a challenge to use SoM with COTS based memories devices in a radiation sensitive environment. In order to achieve these requirements, mitigation measures, such as the use of redundant or alternative memory devices and in-flight reconfiguration, are important in terms of reliability. Reprogramming strategies e.g. partial dynamic reconfiguration and scrubbing techniques are published in the past. With a remote sensing instrument for atmospheric temperature measurements using a SRAM-based Xilinx Zynq-7000 SoM, we combine some of these techniques with supervisor circuits to select the boot image from alternative memory devices. The approach distinguishes between programmable logic and processing system reconfiguration, and enables in-flight firmware updates in the case of Single Event Effect (SEE) hazards or changing measurement conditions

Learning Regularization Parameter-Maps for Variational Image Reconstruction using Deep Neural Networks and Algorithm Unrolling

We introduce a method for fast estimation of data-adapted, spatio-temporally dependent regularization parameter-maps for variational image reconstruction, focusing on total variation (TV)-minimization. Our approach is inspired by recent developments in algorithm unrolling using deep neural networks (NNs), and relies on two distinct sub-networks. The first sub-network estimates the regularization parameter-map from the input data. The second sub-network unrolls T iterations of an iterative algorithm which approximately solves the corresponding TV-minimization problem incorporating the previously estimated regularization parameter-map. The overall network is trained end-to-end in a supervised learning fashion using pairs of clean-corrupted data but crucially without the need of having access to labels for the optimal regularization parameter-maps. We prove consistency of the unrolled scheme by showing that the unrolled energy functional used for the supervised learning Γ-converges as T tends to infinity, to the corresponding functional that incorporates the exact solution map of the TV-minimization problem. We apply and evaluate our method on a variety of large scale and dynamic imaging problems in which the automatic computation of such parameters has been so far challenging: 2D dynamic cardiac MRI reconstruction, quantitative brain MRI reconstruction, low-dose CT and dynamic image denoising. The proposed method consistently improves the TV-reconstructions using scalar parameters and the obtained parameter-maps adapt well to each imaging problem and data by leading to the preservation of detailed features. Although the choice of the regularization parameter-maps is data-driven and based on NNs, the proposed algorithm is entirely interpretable since it inherits the properties of the respective iterative reconstruction method from which the network is implicitly defined

Unrolled three-operator splitting for parameter-map learning in low dose X-ray CT reconstruction

We propose a method for fast and automatic estimation of spatially dependent regularization maps for total variation-based (TV) tomography reconstruction. The estimation is based on two distinct sub-networks, with the first sub-network estimating the regularization parameter-map from the input data while the second one unrolling T iterations of the Primal-Dual Three-Operator Splitting (PD3O) algorithm. The latter approximately solves the corresponding TV-minimization problem incorporating the previously estimated regularization parameter-map. The overall network is then trained end-to-end in a supervised learning fashion using pairs of clean-corrupted data but crucially without the need of having access to labels for the optimal regularization parameter-maps