4,820 research outputs found
Beneficial effects of cannabinoids (CB) in a murine model of allergen-induced airway inflammation: Role of CB(1)/CB(2) receptors.
No full textThe endocannabinoid system (ECS) consists of two cannabinoid (CB) receptors, namely CB(1) and CB(2) receptor, and their endogenous (endocannabinoids) and exogenous (cannabinoids, e.g. delta-9-tetrahydrocannabinol (THC)) ligands which bind to these receptors. Based on studies suggesting a role of THC and the ECS in inflammation, the objective of this study was to examine their involvement in type I hypersensitivity using a murine model of allergic airway inflammation. THC treatment of C57BL/6 wildtype mice dramatically reduced airway inflammation as determined by significantly reduced total cell counts in bronchoalveolar lavage (BAL). These effects were greatest when mice were treated during both, the sensitization and the challenge phase. Furthermore, systemic immune responses were significantly suppressed in mice which received THC during sensitization phase. To investigate a role of CB(1/2) receptors in this setting, we used pharmacological blockade of CB(1) and/or CB(2) receptors by the selective antagonists and moreover CB(1)/CB(2) receptor double-knockout mice (CB(1)(-/-)/CB(2)(-/-)) and found neither significant changes in the cell patterns in BAL nor in immunoglobulin levels as compared to wildtype mice. Our results indicate that the activation of the ECS by applying the agonist THC is involved in the development of type I allergies. However, CB(1)/CB(2) receptor-independent signalling seems likely in the observed results
A historical comment about the GVT in short interval
No full textIn this article, the author introduces the history, progress and method in the Goldbach-Vinogradov Theorem in short interval by which every sufficiently large odd integer could be expressed as the sum of three almost equal prime numbers.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000183488400018&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701MathematicsCPCI-S(ISTP)
Investigation on the DC CB Performance during a Current Interruption Failure at First Current Zero
No full textThe vacuum interrupter is used as the key component of an active DCCB due to its excellent interruption and dielectric recovery characteristics after current zero. The vacuum interrupter can only interrupt the fault currents below the limitation of a critical di/dt and TIV, otherwise it causes a reignition and the interruption failure. In this paper, a detailed active injection DC CB model is developed, considering operation delay of switches, parasitic parameters of switches and thorough control logic. The limitation dielectric strength between the vacuum gap is defined by the cold break down voltage. Based on the numerical modelling, investigation will be performed to see the performance of DC CB with a failure interruption on the first current zero. The simulation results can help to optimize the injection circuit parameters when DC CB has a failure on the first current zero and has to interrupt in the next current zeros. This algorithm will consider predefined threshold of di/dt, chopping current and variable operation time in different scenarios.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Intelligent Electrical Power Grid
Cb-LIKE
No full textGewitterzellen mit ihren negativen Begleiterscheinungen wie Starkregen, Hagel
oder Fallwinden verursachen Verspätungen sowie Flugausfälle und sind damit für
höhere Kosten der Airlines und Flughafenbetreiber verantwortlich. Eine verlässliche
Vorhersage von Gewittern bis zu mehreren Stunden könnte dagegen den
Entscheidungsträgern am Flughafen einen größeren zeitlichen Spielraum geben,
um auf mögliche Gewitterzellen angemessen zu reagieren und adäquate Maßnahmen
zu ergreifen. Zur Bereitstellung zuverlässiger Gewittervorhersagen bis zu
sechs Stunden wurde Cb-LIKE am Deutschen Zentrum für Luft- und Raumfahrt
(DLR) entwickelt.
Der neue Gewittervorhersagealgorithmus wird in der vorliegenden Dissertation
detailliert vorgestellt. Cb-LIKE ist ein automatisiertes System, das unter
Verwendung von Modelldaten des COSMO-DE Wettermodells des Deutschen
Wetterdienstes (DWD) Gebiete ausweist, die eher für oder gegen eine Entwicklung
von Gewittern sprechen. Vier atmosphärische Parameter (CAPE, Vertikalwind,
Radarreflektivität und Temperatur an der Wolkenobergrenze) fließen in
das System ein. Eine neu entwickelte „Best-Member-Selection“ sorgt dabei durch
einen Abgleich zur aktuellen Gewittersituation für die automatische Auswahl des
realistischsten Modelllaufes aus einem Ensemble. Dadurch wird die beste Datengrundlage
für die Berechnung der Gewittervorhersagen gewährleistet. Für die
Auswahl des besten Members stehen vier verschiedene Modi zur Verfügung. Ein
neu entwickeltes Fuzzy-Logik System ermöglicht anschließend die Kombination
der Modelldaten und die Berechnung eines Gewitterindikators von 11,6¯6 bis 88,3¯3
für jeden Gitterpunkt des Modells für die nächsten sechs Stunden in stündlichen
Intervallen. Je höher der Wert des Indikators, desto mehr sprechen die Modellparameter
für die Entstehung von Gewittern. Zusätzlich wird die Vorhersagequalität
des neuen Algorithmus anhand einer umfassenden Verifikation unter Verwendung
einer „neighbourhood-verification“ Technik und von „multi-event contingency tables“
untersucht. Für die Sommerperiode 2012 weist Cb-LIKE im Vergleich zur
COSMO-DE Radarreflektivität bessere Werte in den Verifikationsgrößen auf. So
ist das „Fehlalarmverhältnis“ für den neuen Algorithmus niedriger (0,48 zu 0,56),
die „Wahrscheinlichkeit der Detektion“ (0,52 zu 0,45) und der „Critical Success
Index“ (0,50 zu 0,48) fallen dagegen höher aus. Die Resultate zeigen, dass der Cb-
LIKE Algorithmus eine sinnvolle neue Methodik für Gewittervorhersagen von hoher
Qualität auf der Datenbasis des COSMO-DE Modells darstellt. Die Ergebnisse
aus der Verifikation ermöglichen außerdem die Übersetzung des Cb-LIKE Indikatorfeldes
in die gewünschten probabilistischen Gewittervorhersagen. Zusätzlich
wird die erfolgreiche Implementierung der Cb-LIKE Gewittervorhersagen in das
WxFUSION System, eine graphische Benutzeroberfläche, vorgestellt.Thunderstorm cells with their adverse weather hazards like heavy rain, hail or
downbursts cause delays and flight cancellations at airports and, as a negative
result, the airlines and airport operators have to bear high additional cost. A
reliable thunderstorm forecast up to several hours could provide more time for the
decision makers at the airport for an appropriate reaction on possible storm cells
and initiation of adequate counteractions. To provide the required thunderstorm
forecasts up to six hours Cb-LIKE has been developed at the DLR (Deutsches
Zentrum für Luft- und Raumfahrt) Institute of Atmospheric Physics.
The development of the new algorithm is described in detail in the present dissertation.
Cb-LIKE is an automated system which designates areas with possible
thunderstorm development by using model data of the COSMO-DE numerical
weather prediction model, which is driven by the German Meteorological Service
(DWD). Four atmospheric parameters (CAPE, vertical wind velocity, radar reflectivity
and cloud top temperature) of the model output are used within the
system. A newly developed “Best-Member-Selection“ allows the automatic selection
of that model run of a COSMO-DE model ensemble which matches best
the observed storm situation. Thereby, the application of the best available data
basis for the calculation of the thunderstorm forecasts is ensured. Altogether
there are four different modes for the selection of the best member. A newly
developed fuzzy logic system enables the subsequent combination of the model
data and the calculation of a thunderstorm indicator within a value range of
11. ¯ 66 up to 88. ¯ 33 for each grid point of the model domain for the following six
hours in hourly intervals. The higher the indicator the more the model parameters
imply the development of thunderstorms. The forecasting quality of the new
algorithm is demonstrated by a thorough verification using a neighborhood verification
approach and multi-event contingency tables. For the summer period
of 2012 Cb-LIKE shows better results in the verification scores in comparison
to the COSMO-DE radar reflectivity. For example the new algorithm features a
lower „False Alarm Ratio“ (0,48 to 0,56) and a higher „Probability of Detection“
(0,52 to 0,45) and „Critical Success Index“ (0,50 to 0,48). The results show
that Cb-LIKE is a sensible novel approach to obtain probabilistic thunderstorm
forecasts of high quality on the data basis of the COSMO-DE model. Finally, the
implementation of the Cb-LIKE forecasts into the WxFUSION system which is
a graphical user interface is presented
Technical performance of different DC CB technologies for future HVDC Grids
No full textMultiterminal dc (MTDC) network is preferred due to its reliability, security of supply and flexibility. However, MTDC network also comes with the protection challenges resulting from dc faults. Hence, the dc circuit breaker (DC CB) is imperative in such a network. In these recent years, several DC CB technologies have been proposed and demonstrated by different manufacturers. Besides, these DC CB technologies differ from each other in terms of the speed of operation, interruption capability and costs. Hence, for the optimal performance of the MTDC network, a study of the co-ordinative operation of different DC CB technologies is required. In this thesis, two typical types of DC CBs are modelled in detail and implemented in a 4-terminal MTDC network in PSCAD environment, by considering operation time, interruption capability and interruption characteristics. The obtained results are used for DC CB’s selection optimization methodology for the future MTDC networks. Similarly, a scaled model of DC CB has to be analysed in terms of its interruption capability in MTDC network considering various scenarios. Therefore, in this master thesis, technical performance of DC CB technologies is conducted for a test and multiterminal dc network in EMT based software environment.The DC CB is the key to unlock the reliable operation of a Multi-terminal direct current network, whereas fast, effective and accurate models are frequently needed for system-level studies. Due to higher subsystem components in DC CB, a detailed DC CB model creates a bottleneck in the network analysis. This thesis also proposes and compares, an average model with a detailed model of Voltage source converter Assisted Resonant Current (VARC) and Mechanical DC CB in MTDC Network in terms of their performance and computation time for two typical simulation cases. The average and detailed model is modelled and simulated on the PSCAD/EMTDC electromagnetic transient platform. Decisively, this thesis concludes by presenting an accurate response of the average model during the fast transient event, showing additional computational advantage.<br/
Atra-Hasis
No full textBeach soundscapes and choral works sung from portions of the ancient flood myth poem Atra-Hasis. Written nearly 4000 years ago, the Babylonian Atra-hasis is an iconic poem with an eternal message for mankind. It tells the story of how a thoughtless population weighs heavily upon the earth, such that the gods are forced to act. They first send forth a great sickness, then a great famine. But when neither of these can quiet the noise and chaos of humans, they are forced to send forth a great flood to wash away all mankind. These soundscapes and choral works were developed as part of the ‘Over Lunan’ performance project.
With special thanks to Dr. Martin Worthington, Prof. Nathan Wasserman, Charlotte Steeb M.A. for generous guidance and support in working through the Bablyonian pronunciation and for filling in gaps in the text with their extensive knowledge of the latest scholarship and discoveries.
Composition and Sound Design – Andrew Knight-Hill
Choir – Chamber Choir from the University of St Andrews Music Centre
Rebecca Black
Sarah Greer
James McNinch
Nathanael Fagerson
Ross McArthur
Guy Minch
Elizabeth Unsworth Wilson
Jane Pettegree
Choir Director – Claire Innes-Hopkins
Voice – Prof. Nathan Wasserman
Additional Sound Recording – Steve Urquhart
Babylonian Language Consultants – Dr. Martin Worthington, Prof. Nathan Wasserman, Charlotte Steeb M.A.
Atra-Hasīs Text Adapted from – W. G. Lambert; A. R. Millard (1969) Atra-ḫasīs: The Babylonian Story of the Flood. London: OUP. [with additions in bold
The characteristics of the polish CB-language
No full textThe paper analyzes the language used by drivers on the Citizens’ Band radio (CB radio). The
users of the radio communicate only in speech, their communication is highly pragmatic and
based on partnership. The utterances alternate between formal and informal ones, which
determines the range and register of vocabulary. Drivers often use diminutives and polite
addresses thus creating the atmosphere of mutual respect and cordiality, which can be
comforting and reassuring for strangers who happen to establish a casual contact. The specific
language used on the CB radio fulfils two basic functions: it creates a sense of community
among drivers and protects the information passed on as warnings. At the end of the paper,
the author appends a comprehensive glossary of the CB language
Cb-Like: Gewittervorhersagen bis zu sechs Stunden mit Fuzzy-Logik
No full textCB-LIKE ist ein automatisiertes Sytem, das unter Verwendung von Modelldaten des COSMO-DE Wettermodells des Deutschen Wetterdienstes (DWD) Gebiete ausweist, die eher für oder gegen eine Entwicklung von Gewittern sprechen
Modelling of GO/PPy/CB and rGO/PPy/CB nanocomposite supercapacitors using an electrical equivalent circuit
No full textIn this study, supercapacitor device performances of graphene oxide (GO), reduced graphene oxide (rGO), polypyrrole (PPy), and ternary nanocomposites of GO, PPy, and carbon black (CB) as GO/PPy/CB and rGO/PPy/CB were firstly prepared using the in situ polymerization method. The obtained composite materials were characterized by scanning electron microscopy energy–dispersive X-ray (SEM–EDX), Fourier-transform infrared-attenuated transmission reflectance (FTIR-ATR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), atomic force microscopy (AFM), Brunauer–Emmett–Teller (BET) surface area analysis, cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopic (EIS) methods. The highest specific capacitance (Csp) of the rGO/PPy/CB nanocomposite was obtained as Csp = 39, 48, and 27.86 F × g?1 by three methods of CV, GCD, and EIS, respectively. Two equivalent circuit models of Rs(CdlRct) and LRs(QRct) were presented to compare equivalent circuit parameters. Theoretical and experimental values are compatible with each other. Graphical abstract: [Figure not available: see fulltext.]. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Trakya ÜniversitesiThis work is a part of the research project NKUBAP.01.?NAP.19.213 approved by the Scientific and Research Project Unit (Tekirdag Namik Kemal University). This research grant is gratefully acknowledged. We thank Prof. Dr. Murat Turkyilmaz and Ozan Yoruk (PhD student) for TGA and BET measurements (TUTAGEM, Trakya University, Turkey)
„Misiek z okularami na hulajnodze”, czyli o CB-polszczyźnie
No full textThe paper analyzes the language used by drivers on the Citizens’ Band radio (CB radio). The users of the radio communicate only in speech, their communication is highly pragmatic and based on partnership. The utterances alternate between formal and informal ones, which determines the range and register of vocabulary. Drivers often use diminutives and polite addresses thus creating the atmosphere of mutual respect and cordiality, which can be comforting and reassuring for strangers who happen to establish a casual contact. The specific language used on the CB radio fulfils two basic functions: it creates a sense of community among drivers and protects the information passed on as warnings. At the end of the paper, the author appends a comprehensive glossary of the CB language
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