186 research outputs found
A modified index for the description of the ionospheric short- and long-term activity
A modified ionospheric activity index AI has been developed on the basis of ionospheric foF2 observations. Such index can be helpful for an interested user to get information about the current state of the ionosphere. Using ionosonde data of the station Juliusruh (54.6° N; 13.4°E) this index has been tested for the time interval from January 1996 until December 2008. This index has no diurnal and seasonal variations, only a small positive dependence on the solar activity could be found. The variability of this index has, however, a marked seasonal variability with maxima during the equinoxes, a clear minimum in summer, and enhanced values in winter. The observed variability of AI is strongly correlated with the geomagnetic activity, most markedly during the equinoxes, whereas the influence of the solar activity is markedly smaller and mostly insignificant. Strong geomagnetic disturbances cause in middle latitudes in general negative disturbances in AI, mostly pronounced during equinoxes and summer and only partly during winter, thus in agreement with the current physical knowledge about ionospheric storms. © 2010 Author(s)
Long-term trends in the ionospheric F2 region with different solar activity indices
A new comprehensive data collection by Damboldt and Suessmann (2012a) with monthly foF2 and M(3000)F2 median values is an excellent basis for the derivation of long-term trends in the ionospheric F2 region. Ionospheric trends have been derived only for stations with data series of at least 22 years (124 stations with foF2 data and 113 stations with M(3000)F2 data) using a twofold regression analysis depending on solar and geomagnetic activity. Three main results have been derived: Firstly, it could be shown that the solar 10.7 cm radio flux F10.7 is a better index for the description of the solar activity than the relative solar sunspot number R as well as the solar EUV proxy E10.7. Secondly, the global mean foF2 and <hm F2 trends derived for the interval between 1948 and 2006 are in surprisingly good agreement with model calculations of an increasing atmospheric greenhouse effect (Rishbeth and Roble, 1992). Thirdly, during the years 2007 until 2009, the hmI F2 values and to a smaller amount the foF2 values strongly decrease. The reason for this effect is a reduction of the thermospheric density and ionization due to a markedly reduced solar EUV irradiation and extremely small geomagnetic activity during the solar cycle 23/24 minimum
Karl Alexander Ferdinand Kluge (1782 - 1844), der �animalische Magnetismus� und heutige Hypnosekonzepte
In der vorliegenden Arbeit wird Leben und Werk von Carl Alexander Ferdinand Kluge dargestellt mit dem Schwerpunkt auf seinem Werk über den animalischen Magnetismus �Versuch einer Darstellung des animalischen Magnetismus als Heilmittel�.
Kluge leistet mit seinem Werk einen äußerst wertvollen Beitrag für die Weiterentwicklung und Anwendung des Magnetismus. Dementsprechend großen Anklang fand sein Werk zur damaligen Zeit, es wurde in 5 verschiedene Sprachen übersetzt und wurde dreimal aufgelegt.
Seine Leistung bestand dabei nicht in einer bahnbrechend neuen Erkenntnis über den Magnetismus, sondern in der systematischen Aufbereitung des ungeordneten, brachliegenden Wissensstandes. Er machte sein Werk damit zur Grundlage für alle praktisch tätigen Anwender und auch Wissenschaftler auf diesem Gebiet. Er muss damit als Systematiker des animalischen Magnetismus gelten.
Kluge gliedert sein Werk �Versuch einer Darstellung des animalischen Magnetismus als Heilmittel� in einen theoretischen und einen praktischen Teil. Im theoretischen Teil befasst er sich zunächst mit der Geschichte des Magnetismus, deren erste Erfahrungen er schon in den Überlieferungen der ersten Hochkulturen der Ägypter und Griechen findet und sich bis in seine Zeit fortsetzt. Es folgt ein detaillierter Lebenslauf von Franz Anton Mesmer, den �Wiederentdecker dieses Heilmittels�, der versuchte ihn mit wissenschaftlichen Mitteln zu beschreiben und eine komplexe Theorie dazu entwickelte.
Im weiteren geht Kluge auf die magnetischen Erscheinungen ein, die bei den Sitzungen bei den Patienten beobachtbar sind und untergliedert diese in 6 Grade der �Sinnlichkeit�. Dabei nennt er in den unteren zwei Graden als besondere Erscheinungen physiologische Phänomene wie das Ansteigen der Körpertemperatur und der Atemfrequenz und das Erleben eines Schweregefühls, was auch heutzutage unter Hypnose messbare Phänomene sind. Im dritten Grad beschreibt Kluge den �magnetischen Schlaf�, den man heute als Trance- Zustand bezeichnen würde und beschreibt mit seinen Worten das heute als �posthypnotischen Amnesie� bekannte Phänomen der retrograden Amnesie. In den folgenden drei Graden erreiche der Patient laut Kluge Zustände, in denen erhöhte Sinneswahrnehmungen und hellseherische Fähigkeiten zu Tage treten. In den Beschreibungen kann man Hinweise auf das Auftreten von Hypnosephänomenen wie den Rapport, die Altersregression, den �posthypnotischen Auftrag� und die hohe Imaginationsfähigkeit erkennen.
Im letzten Abschnitt des theoretischen Teils beleuchtet er die physikalischen und physiologischen Grundlagen der Wirkung des animalischen Magnetismus und gibt somit einen interessanten Überblick über den neurophysiologischen Wissensstand seiner Zeit.
Den folgenden praktischen Teil untergliedert Kluge in drei Teile. Im ersten befasst sich Kluge mit den Anforderungen und nötigen Eigenschaften eines Magnetiseurs, der zweite Teil beschreibt die genaue praktische Anwendung des Magnetismus als Heilmittel. Im dritten Teil trifft er Aussagen zu den verschiedenen Krankheitsbildern, die mit dem Magnetismus behandelt werden können.
Im Anschluss an die Darstellung von Kluges Werk befasst sich die vorliegende Arbeit mit der Weiterentwicklung des Magnetismus zur heutigen Hypnose
Towards positive energy districts: assessing the contribution of virtual power plants and energy communities
The concept of positive energy districts (PED) encompasses a range of policies and strategies in response to climate protection targets in urban areas. Due to the limited potential of renewable energy in urban neighborhoods, broader definitions of PED are proposed that allow for energy exchange through the grid infrastructure. This study evaluates demand side management in combination with a virtual power plant (VPP) to assess the impact on the design of PED. In particular, the optimal customer behavior in response to flexible electricity tariffs is analyzed. A techno-economic energy system model is proposed for an urban area in Germany that optimizes the customer cost and the VPP’s margin. This includes electrical energy generation, storage, demand, and access to the short-term electricity market. Based on economic analysis, a dynamic market-based tariff allows the VPP to maximize profit margins. Consumers benefit when the local balances of renewable energy supply and demand are integrated into the dynamic tariff
Economic potential of demand side management based on smart metering of youth hostels in Germany
Additional electricity meters behind the grid access point can improve understanding of energy consumption patterns and thus, adjust consumption behavior. For this study, smart meters were installed in three hostels, out of which two are analyzed further in this paper. Starting from an onsite inspection, all appliances were assigned to reasonable groups for sub-metering. Based on data for the year 2021, the sites are characterized according to the sub-metering concept. In addition, load profiles for type-days are derived, which allows to establish a baseload during COVID lockdown and compare it to consumption patterns for normal occupation. In the prescriptive part, the demand profiles are analyzed regarding their economic potential for load shifting. Consumption data for one week with normal occupation is used as input for techno-economic modeling. The mixed-integer model minimizes electricity purchasing costs for different scenarios including dynamic tariffs and onsite generation from photovoltaics
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Identification of potential precursors for the occurrence of Large-Scale Traveling Ionospheric Disturbances in a case study during September 2017
Traveling Ionospheric Disturbances (TIDs) reflect changes in the ionospheric electron density which are caused by atmospheric gravity waves. These changes in the electron density impact the functionality of different applications such as precise navigation and high-frequency geolocation. The Horizon 2020 project TechTIDE establishes a warning system for the occurrence of TIDs with the motivation to mitigate their impact on communication and navigation applications. This requires the identification of appropriate indicators for the generation of TIDs and for this purpose we investigate potential precursors for the TID occurrence. This paper presents a case study of the double main phase geomagnetic storm, starting from the night of 7th September and lasting until the end of 8th September 2017. Detrended Total Electron Content (TEC) derived from Global Navigation Satellite System (GNSS) measurements from more than 880 ground stations in Europe was used to identify the occurrence of different types of large scale traveling ionospheric disturbances (LSTIDs) propagating over the European sector. In this case study, LSTIDs were observed more frequently and with higher amplitude during periods of enhanced auroral activity, as indicated by increased electrojet index (IE) from the International Monitor for Auroral Geomagnetic Effects (IMAGE). Our investigation suggests that Joule heating due to the dissipation of Pedersen currents is the main contributor to the excitation of the observed LSTIDs. We observe that the LSTIDs are excited predominantly after strong ionospheric perturbations at high-latitudes. Ionospheric parameters including TEC gradients, the Along Arc TEC Rate (AATR) index and the Rate Of change of TEC index (ROTI) have been analysed for their suitability to serve as a precursor for LSTID occurrence in mid-latitude Europe, aiming for near real-time indication and warning of LSTID activity. The results of the presented case study suggest that the AATR index and TEC gradients are promising candidates for near real-time indication and warning of the LSTIDs occurrence in mid-latitude Europe since they have a close relation to the source mechanisms of LSTIDs during periods of increased auroral activity
Maize Transposable Elements Ac/Ds as Insertion Mutagenesis Tools in Candidaalbicans
In non-model systems genetic research is often limited by the lack of
techniques for the generation and identification of gene mutations. One
approach to overcome this bottleneck is the application of transposons for
gene tagging. We have established a two-element transposon tagging system,
based on the transposable elements Activator (Ac)/Dissociation (Ds) from
maize, for in vivo insertion mutagenesis in the fungal human pathogen Candida
albicans. A non-autonomous Ds transposon carrying a selectable marker was
constructed into the ADE2 promoter on chromosome 3 and a codon usage-adapted
Ac transposase gene was inserted into the neutral NEUT5L locus on chromosome
5. In C. albicans cells expressing the transposase the Ds element efficiently
excised and reintegrated elsewhere in the genome, which makes the Ac/Ds
transposons promising tools for saturating insertion mutagenesis in clinical
strains of C. albicans
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Lensing from small-scale travelling ionospheric disturbances observed using LOFAR
Observations made using the LOw-Frequency ARray (LOFAR) between 10:15 and 11:48 UT on the 15th of September 2018 over a bandwidth of approximately 25-65 MHz contain discrete pseudo-periodic features of ionospheric origin. These features occur within a period of approximately 10 min and collectively last roughly an hour. They are strongly frequency dependent, broadening significantly in time towards the lower frequencies, and show an overlaid pattern of diffraction fringes. By modelling the ionosphere as a thin phase screen containing a wave-like disturbance, we are able to replicate the observations, suggesting that they are associated with small-scale travelling ionospheric disturbances (TIDs). This modelling indicates that the features observed here require a compact radio source at a low elevation and that the TID or TIDs in question have a wavelength <~30 km. Several features suggest the presence of deviations from an idealised sinusoidal wave form. These results demonstrate LOFAR-s capability to identify and characterise small-scale ionospheric structures
Gene Essentiality Analyzed by In Vivo Transposon Mutagenesis and Machine Learning in a Stable Haploid Isolate of Candida albicans
This work was supported by European Research Council Advanced Award 340087 (RAPLODAPT) to J.B., the Dahlem Centre of Plant Sciences (DCPS) of the Freie Universität Berlin (R.K.), Israel Science Foundation grant no. 715/18 (R.S.), the Wellcome Trust (grants 086827, 075470, 101873, and 200208) and the MRC Centre for Medical Mycology (N006364/1) (N.A.R.G.). Data availability.All of the code and required dependencies for analysis of the TnSeq data are available at https://github.com/berman-lab/transposon-pipeline. Library insertion sequences are available at NCBI under project PRJNA490565 (https://www.ncbi.nlm.nih.gov/bioproject/PRJNA490565). Datasets S1 through S9 are available at https://doi.org/10.6084/m9.figshare.c.4251182.Peer reviewedPublisher PD
pilot ionosonde network for identification of traveling ionospheric disturbances
Travelling Ionospheric Disturbances (TIDs) are the ionospheric signatures of atmospheric gravity waves (AGWs). Their identification and tracking is important because the TIDs affect all services that rely on predictable ionospheric radio wave propagation. Although various techniques have been proposed to measure TID characteristics, their real-time implementation still has several difficulties. In this contribution, we present a new technique, based on the analysis of oblique Digisonde-to-Digisonde (D2D) "skymap" observations, to directly identify TIDs and specify the TID wave parameters based on the measurement of angle-of-arrival, Doppler frequency, and time-of-flight of ionospherically reflected high-frequency (HF) radio pulses. The technique has been implemented for the first time for the Net-TIDE project with data streaming from the network of European Digisonde DPS4D observatories. The performance is demonstrated during a period of moderate auroral activity, assessing its consistency with independent measurements such as data from auroral magnetometers and electron density perturbations from Digisondes and GNSS stations. Given that the different types of measurements used for this assessment were not made at exactly the same time and location, and that there was insufficient coverage in the area between the AGW sources and the measurement lo cations, we can only consider our interpretation as plausible and indicative for the reliability of the extracted TID characteristics. In the framework of the new TechTIDE project (European Commission H2020), a retrospective analysis of the Net-TIDE results in comparison with those extracted from GNSS TEC-based methodologies is currently being attempted, and the results will be the objective of a follow up paper
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