Extension of the IEC 61000-4-20 Annex C to the Use of Arbitrary Transient Signals

Transverse electromagnetic (TEM) waveguides are predominantly used for emission and immunity tests. General requirements for TEM waveguides are given by the IEC 61000-4-20. Annex C of the IEC 61000-4-20 specifies immunity tests based on high-altitude electromagnetic pulses with a double exponential waveform. This waveform's shape is sufficiently defined by the rise time and the pulsewidth. The quality of its transmission within a waveguide can, thus, be expressed by the allowed variation of these parameters. However, other arbitrary signals cannot be reduced to just these characteristic parameters. In this paper, a method is described that offers the possibility to characterize the transmission quality of a TEM cell for arbitrary transient waveforms. It is based on the Pearson correlation coefficient of a so-called reference signal and the signals being measured within the test volume of a TEM cell. Both signals are measured simultaneously with identical field probes in order to be independent from the reproducibility of the signal generator. The signals are windowed and limited to include only the defining reflections and distortions. By means of this signal-dedicated validation procedure, the transmission quality of a TEM waveguide can be validated for an arbitrary transient waveform

Geochemical, Geophysical and Morphological Results from the Chilean Southern Volcanic Zone: The Role of Fluids in Generating the Highest Magmatic Output

In the Collaborative Research Center (SFB574), which studies the role of volatiles and fluids in subduction zones, we have compiled a comprehensive geochemical data set from the Chilean Southern Volcanic Zone. Here we focus on the middle volcanic front (MVF from 34.5-38°S) and the southern volcanic front (SVF from 38-43°S). We also have data from the behind the VF (BVF) volcanism in Argentina. This data set is augmented by calculations of volcano volume, a seismic profile from the forearc through the VF between 39-40°S and geophysical studies offshore the SVF. On the Sr vs Nd isotope diagram, the MVF almost completely overlaps the BVF samples. On Pb isotope diagrams, the MVF falls on the radiogenic end of the positive backarc array. On 206Pb/204Pb vs Sr and Nd isotope diagrams, the unradiogenic end of the BVF array has an EMORB type composition, suggesting an EMORB type of mantle wedge composition. The VF lavas can be explained largely by two component mixing of trench sediments (+/- subducting slab) and an EMORB type of mantle wedge. Combined with higher erupted volumes over shorter time scales for the SVF compared to the MVF (Völker et al., 2011, JVGR), the higher fluid mobile to fluid immobile (e.g. U/Th, Pb/Ce and Ba/Nb) ratios point to a higher fluid flux, whereas the lower more to less immobile incompatible (e.g. La/Yb, La/Sm, Th/Yb, Ta/Yb) element ratios are consistent with higher degrees of melting. On the Sr vs Nd and 206Pb/204Pb vs Sr and Nd isotope ratio diagrams, the SVF is shifted to higher Sr and Nd isotope ratios. We interpret these variations to indicate derivation of the fluids from seawater altered oceanic crust and/or mantle and sediments. The Pb isotopic composition of the SVF is identical to the MVF and is clearly dominated by the composition of the trench sediments. Delta 18O of olivine correlates inversely with U/Th and Nd isotope ratios, extending to lower and higher d18O than found in olivines in mantle peridotites. The low d18O and high U/Th and Nd isotope component present in the SVF (in Llaima and Villarrica) is interpreted to reflect fluids derived from hydrothermally altered oceanic crust and serpentinized upper mantle of the incoming plate, whereas the high d18O endmember primarily in the MVF points to fluids derived from subducted sediments. Beneath the VF between 39-40°S, where Villarrica, one of South America’s most active volcanoes, is located, a low-velocity seismic anomaly, together with high Vp/Vs ratios, is interpreted to reflect greater fluid ascent above the subducting Valdivia Fracture Zone. The combined morphologic (volume), geochemical and geophysical data suggest an enhanced fluid presence beneath much of the SVF (Llaima, Villarrica and Puyehue Volcanoes), probably caused by a stronger hydration of the incoming plate around and between the Valdivia and Chiloe Fracture Zones

Active Reduction of Magnetic Fields in Vehicles

This paper presents an innovative solution for the challenging problem of suppressing low frequent magnetic fields generated by electrical driven powertrains. The solution is based on active field reduction by generating a counter phase magnetic field to suppress the original field. Main principles and technical challenges of such a system are described and discussed. To illustrate the achievable suppression levels, measurement results under different drive modes of two commercially available electrically powered vehicle models (from two different makers) are presented

Literacy in Denmark. Country Report. Short Version

European Literacy Policy Network (ELINET

High-resolution signal-in-space measurements of VHF omnidirectional ranges using UAS

In this paper, we describe measurement results of the signal-in-space of very high frequency (VHF) omnidirectional range (VOR) facilities. In aviation VOR are used to display the current course of the aircraft in the cockpit. To understand the influence of wind turbines (WT) on the signal integrity of terrestrial navigation and radar signals, the signal content and its changes, respectively, must be investigated. So far, only numerical simulations have been carried out on the frequency-modulation (FM) part of the Doppler-VOR (DVOR) signal to estimate the influence of WT on DVOR. Up to now, the amplitude-modulated (AM) part of the DVOR was not assessed at all. In 2016, we presented an unmanned aerial system (UAS) as a carrier for state-of-the-art radio-frequency (RF) measurement instrumentation (Schrader et al., 2016a, c; Bredemeyer et al., 2016), to measure and to record the true signal-in-space (both FM and AM signal) during the flight. The signal-in-space (which refers to time-resolved signal content and field strength, respectively) is measured and sampled without loss of information and, furthermore, synchronously stored with time stamp and with precise position in space, where the measurements were taken

Which medical disciplines diagnose and treat melanoma in Europe in 2019? A survey of experts from melanoma centres in 27 European countries

Background and objectives The incidence of melanoma is increasing. This places significant burden on societies to provide efficient cancer care. The European Cancer Organisation recently published the essential requirements for quality melanoma care. The present study is aimed for the first time to roughly estimate the extent to which these requirements have been met in Europe. Materials and methods A web-based survey of experts from melanoma centres in 27 European countries was conducted from 1 February to 1 August 2019. Data on diagnostic techniques, surgical and medical treatment, organization of cancer care and education were collected and correlated with national health and economic indicators and mortality-to-incidence ratio (MIR) as a surrogate for survival. Univariate linear regression analysis was performed to evaluate the correlations. SPSS software was used. Statistical significance was set at P < 0.05. Results The MIR was lower in countries with a high health expenditure per capita and with a higher numbers of general practitioners (GPs) and surgeons (SURG) per million inhabitants. In these countries, GPs and dermatologists (DER) were involved in melanoma detection; high percentage of DER used dermatoscopy and were involved in the follow-up of all melanoma stages; both medical oncologists (ONC) and dermato-oncologists administered systemic treatments; and patients had better access to sentinel lymph node biopsy and were treated within multidisciplinary tumour boards. Conclusion Based on these first estimates, the greater involvement of GPs in melanoma detection; the greater involvement of highly trained DER in dermatoscopy, dermatosurgery, follow-up and the systemic treatment of melanoma; and the provision of ongoing dermato-oncology training for pathologists, SURG, DER and ONC are necessary to provide an optimal melanoma care pathway. A comprehensive analysis of the melanoma care pathway based on clinical melanoma registries will be needed to more accurately evaluate these first insights

Qualifikation von TEM Wellenleitern. Eine statistische Analyse

Transversal elektromagnetische (TEM-) Wellenleiter können als alternative Testmethode benutzt werden, wenn die Feldverteilung im Prüfvolumen als hinreichend homogen und der TEM-Mode als dominant bestätigt wurden. Die in der ersten Edition der DIN EN 61000-4-20 aufgestellten Bedingungen wurden vom statistischen Ansatz der zweiten Edition nur teilweise korrekt wiedergegeben. Insbesondere für den Nachweis des TEM-Modes war die Annahme von Normalverteilung insofern ungünstig, als dass besonders gute Messwerte zum Nichtbestehen führen konnten. Im Rahmen dieser Arbeit wurden umfangreiche Simulationen und Messungen mit verschiedenen TEM-Wellenleitern durchgeführt. Die so entstandenen Datensätze wurden einer statistischen Analyse unterzogen. Die Untersuchung der Feldhomogenität zeigt, dass die Annahme von Normalverteilung und die Auswertung gemäß DIN EN 61000-4-20 eine sinnvolle Güteziffer für die Feldhomogenität ergeben. Es wird aber auch gezeigt, dass durch die Wahl einer größeren Anzahl von Kalibrierpunkten die Güteziffer gemäß Standard verbessert werden kann. Dieses Vorgehen strebt für eine große Anzahl von Kalibrierpunkten gegen den wahren Wert der Feldhomogenität und ist damit letztlich nur eine genauere Messung. Bei dem Nachweis des TEM-Modes mit der Güteziffer gemäß DIN EN 61000-4-20 kommt es durch die Symmetrie der Normalverteilung zu fehlerhaften Annahmen und zu einer Überschätzung des tatsächlich gesuchten Grenzwertes. Mit der Rayleigh- Verteilung wird eine Verteilungsdichtefunktion vorgeschlagen, die die Verteilung der Messwerte besser abbildet. Die mit dieser Verteilung schon aus einer kleinen Anzahl von Kalibrierpunkten berechenbare Güteziffer liefert einen guten Schätzwert für den wahren Wert des gesuchten 75 % Quantils