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[en] A collection of formulas frequently used in the field of plasma physics has been compiled and prepared for evaluation with the Microsoft Excel spreadsheet program, which runs on an IBM-compatible PC as well as on a Macintosh computer. The present version of this plasma formulary, a worksheet named FORMEX, comprises 133 formulas depending on 23 variables. The formulas are evaluated numerically and these numerical values are promptly updated whenever any of the input variables is changed. A complete set of input variables can be chosen by the name of an experimental device. Stellarators and tokamaks, 16 altogether, have been incorporated in the formulary. A diagram can be displayed to show how a specific formula depends on any of its input variables. Each formula is extensively annotated to show it origin and give literature references. The formulary is operated with a series of macros, all inside the macro sheet named FORMAK, which are invoked by menu commands from a special menu bar. All the information from the formulary, the genuine formulas, the table of numerically evaluated plot coordinates, the notes, and the diagrams can be further processed or transferred to any other application with the help of the usual Excel commands. The formulary is open to adding more formulas and, if needed, variables as well as data of further experimental devices. The FORMEX and FORMAK files are made available by ANONYMOUS FTP via the address FTP.IPP-GARCHING.MPG.DE, which allows public access. (orig.)
[en] Early morning values of the atmospheric electric potential gradient (P.G.) determined for late winter (January-February) at the Nagycenk observatory (Hungary) did not indicate any regular variation according to the 11-year period of solar activity during the last two solar cycles. Nevertheless, when the P.G. data were separated according to the two phases of the Quasi-Biennial Oscillation (QBO) a positive and significant correlation has been found between the atmospheric electric and the solar parameter for the QBO west phase; the correlation was negative and less significant for the QBO east phase. The present results are discussed in accordance with previous ones indicating that the change in the ionospheric potential (i.e. that in a basic element of the atmospheric electric global circuit) seems to be opposite to the solar cycle variation. Additionally, the possibility of a global QBO signal is also discussed
[en] The main points addressed in this study are the following: Statistical distribution patterns of published literature on instrumental analytical techniques 1981-1984; structure of scientific literature and heuristics for identifying active specialities and emerging hot spot research areas in instrumental analytical techniques; growth and growth rates of the literature in some of the identified hot research areas; quality and quantity in instrumental analytical research output. (orig.)
[en] In the present study, differential interferometry and shadowgraphy are combined to determine cavitation-induced pressure fields and corresponding bubble dynamics during laser-induced single-bubble cavitation. An evaluation method is presented that allows to reconstruct the pressure distribution from interference images with high accuracy. The minimum reconstruction accuracy of the pressure amplitudes with the presented method is determined from synthetic data sets for an angular range of to be . On the basis of statistically evaluated data, the energy budget of single cavitation bubbles and the corresponding pressure wave energy could be determined also for weak pressure wave amplitudes in the order of . Graphical abstract: .
BackgroundScenario design is currently not a standardised process. The formulation of storylines representing different dimensions (for example economic or societal developments) demands an investigation of assumption compatibility, coherence, and consistency. Scenario techniques that use expert opinion as the sole information source are particularly appropriate for personal decisions. Contexts where scenarios serve as decision support on a societal level—for example in political decision-making—benefit from unbiased, fact-depicting, multi-dimensional information that is available in statistical data.
MethodsThe presented approach uses the well-established method of Bayesian model averaging for the formulation of consistent, transparent, and intuitively understandable quantitative scenario assumptions. These assumptions are used in quantitative models to produce outlooks and forecasts. Illustrated by the example of quantitative energy models used to investigate developments of the energy system by scenario technique, the approach contrasts with other scenario methods. Bayesian model averaging (BMA) is a method that allows for an evaluation of both system relation stability in terms of observable co-evolvement of phenomena in the past and of future system states of interest based on expert opinion where past evolvements serve as a point of reference.
ResultsThe results are scenarios assessable with respect to (1) the consistency of scenario assumptions in terms of statistical confirmation, (2) the suitability of a quantitative model to represent the scenario, and (3) the statistical uncertainty of the scenario for a given quantitative model. A transparent scenario construction process results in traceable assumption documentation (an exemplary communication is provided in the Appendix). Perhaps, the most important novelty of the approach is the possibility of communicating to decision-makers the associated uncertainty in easily understandable terms. The distinction between provable possible assumptions (based on statistical evidence) and hypothetical assumptions is a novelty and significantly improves the aptitude of scenario study recipients to evaluate scenarios on their part.
ConclusionsBMA provides the possibility for decision-makers (and all recipients of outlooks based on scenario technique) to trace back results to assumptions and provide an evaluation of these assumptions in terms of statistical confirmation. As such, the approach adds to the currently limited methodological diversity in scenario construction techniques.
[en] Quantum two-level systems interacting with the surroundings are ubiquitous in nature. The interaction suppresses quantum coherence and forces the system towards a steady state. Such dissipative processes are captured by the paradigmatic spin-boson model, describing a two-state particle, the ''spin'', interacting with an environment formed by harmonic oscillators. A fundamental question to date is to what extent intense coherent driving impacts a strongly dissipative system. Here we investigate experimentally and theoretically a superconducting qubit strongly coupled to an electromagnetic environment and subjected to a coherent drive. This setup realizes the driven Ohmic spin-boson model. We show that the drive reinforces environmental suppression of quantum coherence, and that a coherent-to-incoherent transition can be achieved by tuning the drive amplitude. An out-of-equilibrium detailed balance relation is demonstrated. These results advance fundamental understanding of open quantum systems in the case of strong light-matter interaction.
[en] A computer assisted spectra interpretation based on special comparison was developed. The search program implements three different searching strategies to be used according to the specific analytical problem: Search for a spectrum of the same substance, partial structure search and spectra identification for mixed substances. It turned out, that the success of a search program depends significantly on the used spectra collection; optimization procedures involve the information content classification for each spectral information. A combined search program is demonstrated for infrared, 13C-NMR and mass spectra. (TW)