17 research outputs found
Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector
A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
Highly Integrated Ultra-Compact Three-Port Converter Systems for Automotive Applications
Three-Port Series-Resonant DC/DC Converter for Automotive Charging Applications
In the energy distribution grid of electric vehicles (EVs), multiple different voltage potentials need to be interconnected, to allow arbitrary power flow between the various energy sources and the different electrical loads. However, between the different potentials, galvanic isolation is absolutely necessary, either due to safety reasons and/or due to different grounding schemes. This paper presents an isolated three-port DC/DC converter topology, which, in combination with an upstream PFC rectifier, can be used as combined EV charger for interconnecting the single-phase AC mains, the high-voltage (HV) battery and the low-voltage (LV) bus in EVs. The proposed topology comprises two synergetically controlled and magnetically coupled converter parts, namely, a series-resonant converter between the PFC-sided DC-link capacitor and the HV battery, as well as a phase-shifted full-bridge circuit equivalent in the LV port, and is mainly characterized by simplicity in terms of control and circuit complexity. For this converter, a simple soft switching modulation scheme is proposed and comprehensively analyzed, in consideration of all parasitic components of a real converter implementation. Based on this analysis, the design of a 3.6 kW, 500 V/500 V/15 V prototype is discussed, striving for the highest possible power density and as low as possible manufacturing costs, by using PCB-integrated windings for all magnetic components. The hardware demonstrator achieves a measured full-load efficiency in charge mode of 96.5% for nominal operating conditions and a power density of 16.4 kWL−1.ISSN:2079-929
Multi-Port Multi-Cell DC/DC Converter Topology for Electric Vehicle’s Power Distribution Networks
Diagnosis of arre diseases: a scoping review of clinical decision support systems
Background: Rare Diseases (RDs), which are defined as diseases affecting no more than 5 out of 10,000 people, are often severe, chronic and life-threatening. A main problem is the delay in diagnosing RDs. Clinical decision support systems (CDSSs) for RDs are software systems to support clinicians in the diagnosis of patients with RDs. Due to their clinical importance, we conducted a scoping review to determine which CDSSs are available to support the diagnosis of RDs patients, whether the CDSSs are available to be used by clinicians and which functionalities and data are used to provide decision support.
Methods: We searched PubMed for CDSSs in RDs published between December 16, 2008 and December 16, 2018. Only English articles, original peer reviewed journals and conference papers describing a clinical prototype or a routine use of CDSSs were included. For data charting, we used the data items “Objective and background of the publication/project”, “System or project name”, “Functionality”, “Type of clinical data”, “Rare Diseases covered”, “Development status”, “System availability”, “Data entry and integration”, “Last software update” and “Clinical usage”.
Results: The search identified 636 articles. After title and abstracting screening, as well as assessing the eligibility criteria for full-text screening, 22 articles describing 19 different CDSSs were identified. Three types of CDSSs were classified: “Analysis or comparison of genetic and phenotypic data,” “machine learning” and “information retrieval”. Twelve of nineteen CDSSs use phenotypic and genetic data, followed by clinical data, literature databases and patient questionnaires. Fourteen of nineteen CDSSs are fully developed systems and therefore publicly available. Data can be entered or uploaded manually in six CDSSs, whereas for four CDSSs no information for data integration was available. Only seven CDSSs allow further ways of data integration. thirteen CDSS do not provide information about clinical usage.
Conclusions: Different CDSS for various purposes are available, yet clinicians have to determine which is best for their patient. To allow a more precise usage, future research has to focus on CDSSs RDs data integration, clinical usage and updating clinical knowledge. It remains interesting which of the CDSSs will be used and maintained in the future
Conceptualization and Analysis of a Next-Generation Ultra-Compact 1.5-kW PCB-Integrated Wide-Input-Voltage-Range 12V-Output Industrial DC/DC Converter Module
The next-generation industrial environment requires power supplies that are compact, efficient, low-cost, and ultra-reliable, even across mains failures, to power mission-critical electrified processes. Hold-up time requirements and the demand for ultra-high power density and minimum production costs, in particular, drive the need for power converters with (i) a wide input voltage range, to reduce the size of the hold-up capacitor, (ii) soft-switching over the full input voltage and load ranges, to achieve low losses that facilitate a compact realization, and (iii) complete PCB-integration for low-cost manufacturing. In this work, we conceptualize, design, model, fabricate, and characterize a 1.5 kW, 12 V-output DC/DC converter for industrial power supplies that is required to operate across a wide 300 V–430 V input voltage range. This module utilizes an LLC-based control scheme for complete soft-switching and a snake-core transformer to divide the output current with a balanced flux among multiple secondary windings. Detailed loss models are derived for every component in the converter. The converter achieves close to 96% peak efficiency with a power density of 337 W in−3 (20.6 kW/dm−3), excellent matching to the derived loss models, and zero-voltage switching even down to zero load. The loss models are used to identify improvements to further boost efficiency, the most important of which is the minimization of delay times in synchronous rectification, and a subsequent improved 1.5 kW hardware module eliminates nearly 25% of converter losses for a peak efficiency of nearly 97% with a power density of 308 W in−3 (18.8 kW dm−3). Two 1.5 kW modules are then paralleled to achieve 3 kW output power at 12 V and 345 W in−3 (21.1 kW dm−3) with ideal current sharing between the secondary outputs and no drop in efficiency from a single module, an important characteristic enabled by the novel snake-core transformer.ISSN:2079-929
se-atlas.de - medical care atlas for people with rare diseases
Eine Erkrankung zählt in der Europäischen Union zu den Seltenen Erkrankungen (SE), wenn diese nicht mehr als 5 von 10.000 Menschen betrifft. Derzeit existiert mit mehr als 6000 SE eine sowohl große als auch heterogene Menge an unterschiedlichen Krankheitsbilder, die in ihrer Symptomatik komplex, vielschichtig und damit im medizinischen Alltag schwierig einzuordnen sind. Dies erschwert Diagnosefindung und Behandlung sowie das Auffinden eines passenden Ansprechpartners, da es nur wenige Experten für jede einzelne SE gibt. Der medizinische Versorgungsatlas für Seltene Erkrankungen www.se-atlas.de ermöglicht anhand von Erkrankungsnamen die Suche nach Versorgungseinrichtungen und Selbsthilfeorganisationen zu bestimmten SE und stellt die Suchergebnisse geografisch dar. Ebenso gibt er einen Überblick über alle deutschen Zentren für SE, die eine Anlaufstelle für betroffene Personen mit unklarer Diagnose darstellen. Der se-atlas dient als Kompass durch die heterogene Menge an Informationen über Versorgungseinrichtungen für SE und stellt niederschwellig Informationen für eine breite Nutzergruppe von Betroffenen bis hin zu Mitgliedern des medizinischen Versorgungsteams bereit.In the European Union a disease is classified as rare if it affects no more than 5 out of 10,000 people. Currently, there are more than 6000 rare diseases, consisting of a large and heterogeneous number of different diseases that are complex in their symptomatology, multidimensional and therefore difficult to classify in everyday medical practice. This complicates the diagnosis and treatment as well as finding a suitable contact person, as there are only a few experts for each individual rare disease. The medical care atlas for rare diseases www.se-atlas.de enables the search for care facilities and patient organizations for specific rare diseases by disease name and presents the search results geographically. It also provides an overview of all German centers for rare diseases, which are a contact point for patients with an unclear diagnosis. The se-atlas serves as a compass through the heterogeneous amount of information on care facilities for rare diseases and provides low-threshold information for a broad user group, from affected persons to members of the medical care team
A vapor-phase-assisted growth route for large-scale uniform deposition of MoS2 monolayer films
In this work a vapor-phase-assisted approach for the synthesis of monolayer MoS2 is demonstrated, based on the sulfurization of thin MoO3-x precursor films in an H2S atmosphere. We discuss the co-existence of various possible growth mechanisms, involving solid-gas and vapor–gas reactions. Different sequences were applied in order to control the growth mechanism and to obtain monolayer films. These variations include the sample temperature and a time delay for the injection of H2S into the reaction chamber. The optimized combination allows for tuning the process route towards the potentially more favorable vapor–gas reactions, leading to an improved material distribution on the substrate surface. Raman and photoluminescence (PL) spectroscopy confirm the formation of ultrathin MoS2 films on SiO2/Si substrates with a narrow thickness distribution in the monolayer range on length scales of a few millimeters. Best results are achieved in a temperature range of 950–1000 °C showing improved uniformity in terms of Raman and PL line shapes. The obtained films exhibit a PL yield similar to mechanically exfoliated monolayer flakes, demonstrating the high optical quality of the prepared layers