Nutzung regenerativer Energie als Träger mechanischer Leistung in der Savannenregion Westafrikas

Ein Großteil des afrikanischen Kontinents ist noch immer von Armut betroffen. Im besonderen Maße ist dieser Zustand prägend für die westafrikanische Republik Togo. Kennzeichnend für die Region ist, dass sie über ein sehr schlecht ausgebautes Energienetz verfügt. Dieses hindert die Entwicklungsbedingungen sowohl im wirtschaftlichen als auch bildungspolitischen Bereich. Um die Weiterentwicklung des Landes zu fördern, hat sich die Technische Hochschule Wildau zum Ziel gestellt, Projektarbeiten im Bereich der Nutzbarmachung regenerativer Energien zu unterstützen und so einen Beitrag zur „Hilfe durch Selbsthilfe“ zu leisten. Im folgenden Artikel wird eine Analyse der Savannenregion hinsichtlich der klimatischen Bedingungen aufgezeigt. Die Analyseergebnisse dienen als Basis für die Ableitung möglicher regenerativer Energieträger und Konzepte zu deren dezentraler Nutzung. Am Fallbeispiel einer Lehmsteinpresse wird gezeigt, inwieweit der für die Region optimale regenerative Energieträger sinnvoll in mechanische Leistung überführt werden kann. Eine Berechnungsgrundlage zur Auslegung entsprechender Leistungsbedarfe wird abgeleitet. Hiermit wird ein Beitrag zum nachhaltigen Verbessern der Lebensbedingungen in Westafrika geleistet

Informationsgewinnung im cyberphysischen Produktionssystem

Im Fokus vieler industrieller Forschungsprojekte steht die intelligente Vernetzung von Entitäten im produktionstechnischen Umfeld. Im Rahmenkonzept Industrie 4.0 wird zum Wandel bestehender hierarchischer Betriebsstrukturen in ein cyberphysisches Produktionssystem beigetragen. Priorität haben Untersuchungen sensorischer Komponenten und deren Verkettung als Führungselement im zukünftigen Produktionsumfeld, welches durch Selbstanalyse, Selbstorganisation und Selbstoptimierung geprägt sein wird. Ziel des Hochschulprojektes (iSensPK) ist die Abwandlung bestehender Sensorkonzepte und deren Nutzbarmachung für das Internet der Dinge. Einen Schwerpunkt wird dabei insbesondere die Definition und Verknüpfung stabiler Kommunikationswege darstellen. Als Demonstrator erfolgt der Aufbau eines 6-Komponenten Kraftmesssystems zur Prüfung und Kalibrierung moderner Greifertechnologien unter Feldbedingungen. Durch die umfangreiche Vernetzung verschiedener Sensoren erfolgt die Erfassung von Störgrößen im Testumfeld. Das gewonnene Abbild der physischen Umgebung dient zur Korrektur der Kraftmessungsergebnisse. Für die Realisierung eines derartigen Kraftmess- und Umfelderfassungssystems wird in den sensorisch relevanten Bereichen der Kommunikation, Sensordatenfusion, Multifunktionsintegration und Selbstorganisation nach Lösungsansätzen gesucht.The main focus of different industrial R&D projects explores possible starting points for the intelligent interconnection of entities in a productional environment. Against a background of ‘Industrie 4.0‘, this contributes to a transformation of existing, hierarchical structures into a cyber physical production system. The focus here is on investigating sensor components and their interlinking as a main element in a future production environment which will be characterised by self-analysis, self-organisation and self-optimisation. The aim of the project iSensPK is to modify sensor concepts in being to facilitate their utilisation in the Internet of Things. Emphasis rests on defining and combining stable lines of communication. A demonstrator is set up, including a six-component force measuring system to enable inspecting and calibration of modern gripping technologies within field conditions. Through adequate linkage of different sensors, the capture of disturbance variables is made possible. The resulting image of the physical environments serves to readjust any measured force values. To implement such a force measuring and environment detecting system, sensorial relevant fields of communication, sensor data fusion, multifunctional integration and self-organisation are searched to conclude approaches to solutions

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at root s=13 TeV

Peer reviewe

Measurement of the W gamma Production Cross Section in Proton-Proton Collisions at root s=13 TeV and Constraints on Effective Field Theory Coefficients

A fiducial cross section for W gamma production in proton-proton collisions is measured at a center-of-mass energy of 13 TeV in 137 fb(-1) of data collected using the CMS detector at the LHC. The W -> e nu and mu nu decay modes are used in a maximum-likelihood fit to the lepton-photon invariant mass distribution to extract the combined cross section. The measured cross section is compared with theoretical expectations at next-to-leading order in quantum chromodynamics. In addition, 95% confidence level intervals are reported for anomalous triple-gauge couplings within the framework of effective field theory.Peer reviewe

Performance of the CMS muon trigger system in proton-proton collisions at √s = 13 TeV

The muon trigger system of the CMS experiment uses a combination of hardware and software to identify events containing a muon. During Run 2 (covering 2015-2018) the LHC achieved instantaneous luminosities as high as 2 × 10 cm s while delivering proton-proton collisions at √s = 13 TeV. The challenge for the trigger system of the CMS experiment is to reduce the registered event rate from about 40 MHz to about 1 kHz. Significant improvements important for the success of the CMS physics program have been made to the muon trigger system via improved muon reconstruction and identification algorithms since the end of Run 1 and throughout the Run 2 data-taking period. The new algorithms maintain the acceptance of the muon triggers at the same or even lower rate throughout the data-taking period despite the increasing number of additional proton-proton interactions in each LHC bunch crossing. In this paper, the algorithms used in 2015 and 2016 and their improvements throughout 2017 and 2018 are described. Measurements of the CMS muon trigger performance for this data-taking period are presented, including efficiencies, transverse momentum resolution, trigger rates, and the purity of the selected muon sample. This paper focuses on the single- and double-muon triggers with the lowest sustainable transverse momentum thresholds used by CMS. The efficiency is measured in a transverse momentum range from 8 to several hundred GeV

Search for long-lived particles decaying to jets with displaced vertices in proton-proton collisions at root s=13 Te V

A search is presented for long-lived particles produced in pairs in proton-proton collisions at the LHC operating at a center-of-mass energy of 13 TeV. The data were collected with the CMS detector during the period from 2015 through 2018, and correspond to a total integrated luminosity of 140 fb(-1). This search targets pairs of long-lived particles with mean proper decay lengths between 0.1 and 100 mm, each of which decays into at least two quarks that hadronize to jets, resulting in a final state with two displaced vertices. No significant excess of events with two displaced vertices is observed. In the context of R-parity violating supersymmetry models, the pair production of long-lived neutralinos, gluinos, and top squarks is excluded at 95% confidence level for cross sections larger than 0.08 fb, masses between 800 and 3000 GeV, and mean proper decay lengths between 1 and 25 mm.Peer reviewe

Search for top squark production in fully hadronic final states in proton-proton collisions at root s=13 TeV

A search for production of the supersymmetric partners of the top quark, top squarks, is presented. The search is based on proton-proton collision events containing multiple jets, no leptons, and large transverse momentum imbalance. The data were collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV, and correspond to an integrated luminosity of 137 fb(-1). The targeted signal production scenarios are direct and gluino-mediated top squark production, including scenarios in which the top squark and neutralino masses are nearly degenerate. The search utilizes novel algorithms based on deep neural networks that identify hadronically decaying top quarks and W bosons, which are expected in many of the targeted signal models. No statistically significant excess of events is observed relative to the expectation from the standard model, and limits on the top squark production cross section are obtained in the context of simplified supersymmetric models for various production and decay modes. Exclusion limits as high as 1310 GeVare established at the 95% confidence level on the mass of the top squark for direct top squark production models, and as high as 2260 GeV on the mass of the gluino for gluino-mediated top squark production models. These results represent a significant improvement over the results of previous searches for supersymmetry by CMS in the same final state.Peer reviewe