Technische Grundlagen der Beschallung von Räumen

Jegliche Form der Beschallung, von kleinen Einbaulautsprechern im Auto bis zu großvolumigen Line Array Systemen in Sportstadien oder bei Open Air Events mit 100.000 Zuhörern, benötigt ein elektroakustisches Wandlersystem, d. h. ein Gerät, das elektrische Energie in Schallwellen verwandelt. Die Eigenschaften des damit aufgebauten Lautsprechers hängen vom physikalischen Prinzip und von der Konstruktion des Wandlers (auch als Treiber bezeichnet) ebenso ab wie von seinem Einbau in ein Gehäuse und der vorgeschalteten Elektronik. Sobald mehr als ein einzelner Lautsprecher betrieben wird, ergeben sich die Eigenschaften der Beschallungsanlage als Ganzes daraus, wie verschiedene Lautsprecher zusammenwirken, um in einem mehr oder weniger ausgedehnten Hörbereich einen gut ausbalancierten Höreindruck zu erreichen. Dies reicht von der zweikanaligen Stereo-Wiedergabe bis zu Systemen mit mehreren Hundert Lautsprechern und entsprechend komplexer Signalverteilung. Dieser Systematik folgt der Aufbau des Kapitels, das zunächst den Aufbau eines einzelnen Lautsprechers behandelt, um in einem zweiten Abschnitt auf Prinzipien beim Zusammenwirken mehrerer Lautsprecher einzugehen, die man je nach Anwendung als Wiedergabeverfahren oder als Beschallungstechnik bezeichnen kann

The Universal One-Loop Effective Action

We present the universal one-loop effective action for all operators of dimension up to six obtained by integrating out massive, non-degenerate multiplets. Our general expression may be applied to loops of heavy fermions or bosons, and has been checked against partial results available in the literature. The broad applicability of this approach simplifies one-loop matching from an ultraviolet model to a lower-energy effective field theory (EFT), a procedure which is now reduced to the evaluation of a combination of matrices in our universal expression, without any loop integrals to evaluate. We illustrate the relationship of our results to the Standard Model (SM) EFT, using as an example the supersymmetric stop and sbottom squark Lagrangian and extracting from our universal expression the Wilson coefficients of dimension-six operators composed of SM fields.Comment: 30 pages, v2 contains additional comments and corrects typos, version accepted for publication in JHE

FCC-ee: The Lepton Collider: Future Circular Collider Conceptual Design Report Volume 2

In response to the 2013 Update of the European Strategy for Particle Physics, the Future Circular Collider (FCC) study was launched, as an international collaboration hosted by CERN. This study covers a highest-luminosity high-energy lepton collider (FCC-ee) and an energy-frontier hadron collider (FCC-hh), which could, successively, be installed in the same 100 km tunnel. The scientific capabilities of the integrated FCC programme would serve the worldwide community throughout the 21st century. The FCC study also investigates an LHC energy upgrade, using FCC-hh technology. This document constitutes the second volume of the FCC Conceptual Design Report, devoted to the electron-positron collider FCC-ee. After summarizing the physics discovery opportunities, it presents the accelerator design, performance reach, a staged operation scenario, the underlying technologies, civil engineering, technical infrastructure, and an implementation plan. FCC-ee can be built with today’s technology. Most of the FCC-ee infrastructure could be reused for FCC-hh. Combining concepts from past and present lepton colliders and adding a few novel elements, the FCC-ee design promises outstandingly high luminosity. This will make the FCC-ee a unique precision instrument to study the heaviest known particles (Z, W and H bosons and the top quark), offering great direct and indirect sensitivity to new physics

FCC Physics Opportunities: Future Circular Collider Conceptual Design Report Volume 1

We review the physics opportunities of the Future Circular Collider, covering its e+e-, pp, ep and heavy ion programmes. We describe the measurement capabilities of each FCC component, addressing the study of electroweak, Higgs and strong interactions, the top quark and flavour, as well as phenomena beyond the Standard Model. We highlight the synergy and complementarity of the different colliders, which will contribute to a uniquely coherent and ambitious research programme, providing an unmatchable combination of precision and sensitivity to new physics

A metasynthesis of qualitative studies regarding opinions and perceptions about barriers and determinants of health services’ accessibility in economic migrants

Background: Access to health services is an important health determinant. New research in health equity is required, especially amongst economic migrants from developing countries. Studies conducted on the use of health services by migrant populations highlight existing gaps in understanding which factors affect access to these services from a qualitative perspective. We aim to describe the views of the migrants regarding barriers and determinants of access to health services in the international literature (1997–2011). Methods: A systematic review was conducted for Qualitative research papers (English/Spanish) published in 13 electronic databases. A selection of articles that accomplished the inclusion criteria and a quality evaluation of the studies were carried out. The findings of the selected studies were synthesised by means of metasynthesis using different analysis categories according to Andersen’s conceptual framework of access and use of health services and by incorporating other emergent categories. Results: We located 3,025 titles, 36 studies achieved the inclusion criteria. After quality evaluation, 28 articles were definitively synthesised. 12 studies (46.2%) were carried out in the U.S and 11 studies (42.3%) dealt with primary care services. The participating population varied depending mainly on type of host country. Barriers were described, such as the lack of communication between health services providers and migrants, due to idiomatic difficulties and cultural differences. Other barriers were linked to the economic system, the health service characteristics and the legislation in each country. This situation has consequences for the lack of health control by migrants and their social vulnerability. Conclusions: Economic migrants faced individual and structural barriers to the health services in host countries, especially those with undocumented situation and those experimented idiomatic difficulties. Strategies to improve the structures of health systems and social policies are needed.Carolina Foundation (Spain), Mario Benedetti Foundation of the University of Alicante, Regional Ministry of Education (Generalitat Valenciana) (BEST/2009/003). Healthcare Research Fund of the Spanish Ministry of Health and Social Policy (PI 0790470)