Extensive Experimental and Analytical Investigation of the Aerodynamic Flow Field of Labyrinth Seals with Innovative Liner Configurations

The state-of-the-art sealing systems in aircraft engines are labyrinth seals to regulate mass flow between rotating components. To prevent structural damage of vital parts during a rubbing process, abradable liner configurations with hollow body structures are applied on the stator. Compared to smooth stator surfaces, these structures increase the cross-sectional area of the sealing gap and, thus, lead to a higher leakage. The aim of this paper is to identify the main geometrical parameters influencing the aerodynamic behavior of various liner configurations. As a basis of an analytical study, an extensive experimental database is required. For this purpose, a test rig is set up at the Institute of Thermal Turbomachinery (ITS). Three liner structures (honeycomb, rhombus, and polyhedral structures), two seal fin configurations, and the effect of the adjusted nominal clearances (0.1-1.0mm) and different pressure conditions are investigated. The experimental results will be presented, discussed, and evaluated by means of established parameters. The focus is on the leakage of the seal, the discharge coeffcient, and the equivalent gap width. Additionally, the influence of the geometric shape of the liner structures is discussed. Flow separation and flow direction play the main role. With the results of this paper, optimization guidelines are derived for the design of innovative liner configurations

Re-theorising the core: a ‘globalized’ business elite in Santiago, Chile

World systems theory continues to be a widely adopted approach in theorisations of the contemporary world economy. An important epistemological component to world systems theory is the metaphor of core-periphery. Recent work within the approach has sought to transcend earlier criticisms of regional conceptions of cores, peripheries and semi-peripheries by an increasing sensitivity to local differences and an increasing emphasis on Wallerstein's original idea of core-periphery as process, operating at all scales in the contemporary world system. However, this paper argues that the core-periphery metaphor currently used by world systems theorists is founded around a restrictively narrow spatial epistemology. Such a narrow epistemology implements the core-periphery metaphor only as something which produces territorial outcomes in the physical world. This paper contends that recent work within the social services, concerned with the globalization debate and issues of spatial epistemology, should inform world systems theory in producing a reformulated spatial understanding of the core-periphery metaphor, embodying a wider conception of space to include abstract social spaces. This argument is developed in the notion that the world economy must also be understood as having a ‘social core’: a transnational diasporic business elite exercising decision-making power over the capitalist world system. The contention is grounded in the presentation of research into a case study of such a ‘globalized’ business elite in the capital city of Chile, Santiago

A Rapid, Highly Sensitive and Open-Access SARS-CoV-2 Detection Assay for Laboratory and Home Testing

RT-qPCR-based diagnostic tests play important roles in combating virus-caused pandemics such as Covid-19. However, their dependence on sophisticated equipment and the associated costs often limits their widespread use. Loop-mediated isothermal amplification after reverse transcription (RT-LAMP) is an alternative nucleic acid detection method that overcomes these limitations. Here, we present a rapid, robust, and sensitive RT-LAMP-based SARS-CoV-2 detection assay. Our 40-min procedure bypasses the RNA isolation step, is insensitive to carryover contamination, and uses a colorimetric readout that enables robust SARS-CoV-2 detection from various sample types. Based on this assay, we have increased sensitivity and scalability by adding a nucleic acid enrichment step (Bead-LAMP), developed a version for home testing (HomeDip-LAMP), and identified open-source RT-LAMP enzymes that can be produced in any molecular biology laboratory. On a dedicated website, rtlamp.org (DOI: 10.5281/zenodo.6033689), we provide detailed protocols and videos. Our optimized, general-purpose RT-LAMP assay is an important step toward population-scale SARS-CoV-2 testing.MK was supported by the Vienna Science and Technology Fund (WWTF) through project COV20-031 (to JZ) and a Cambridge Trust LMB Cambridge Scholarship. Research in the AP lab is supported by the Austrian Science Fund (START Projekt Y 1031-B28, SFB “RNA-Deco” F 80) and EMBO-YIP; research in the JB lab is supported by the European Research Council (ERC- 2015-CoG - 682181). The IMP receives generous institutional funding from Boehringer Ingelheim and the Austrian Research Promotion Agency (Headquarter grant FFG-852936); IMBA is generously supported by the Austrian Academy of Sciences. Work in the LM-A laboratory is supported by grant PID2019- 104176RB-I00/AEI/10.13039/501100011033 of the Spanish Ministry of Science and Innovation, and an institutional grant of the Fundación Ramón Areces.Peer reviewe

The Physics of the B Factories

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C