Power quality and electromagnetic compatibility: special report, session 2

The scope of Session 2 (S2) has been defined as follows by the Session Advisory Group and the Technical Committee: Power Quality (PQ), with the more general concept of electromagnetic compatibility (EMC) and with some related safety problems in electricity distribution systems. Special focus is put on voltage continuity (supply reliability, problem of outages) and voltage quality (voltage level, flicker, unbalance, harmonics). This session will also look at electromagnetic compatibility (mains frequency to 150 kHz), electromagnetic interferences and electric and magnetic fields issues. Also addressed in this session are electrical safety and immunity concerns (lightning issues, step, touch and transferred voltages). The aim of this special report is to present a synthesis of the present concerns in PQ&EMC, based on all selected papers of session 2 and related papers from other sessions, (152 papers in total). The report is divided in the following 4 blocks: Block 1: Electric and Magnetic Fields, EMC, Earthing systems Block 2: Harmonics Block 3: Voltage Variation Block 4: Power Quality Monitoring Two Round Tables will be organised: - Power quality and EMC in the Future Grid (CIGRE/CIRED WG C4.24, RT 13) - Reliability Benchmarking - why we should do it? What should be done in future? (RT 15

Angular Dependent Magnetization Dynamics of Kagome Artificial Spin Ice Incorporating Topological Defects

We report angular-dependent spin-wave spectroscopy on kagome artificial spin ice made of large arrays of interconnected Ni80Fe20 nanobars. Spectra taken in saturated and disordered states exhibit a series of resonances with characteristic in-plane angular dependencies. Micromagnetic simulations allow us to interpret characteristic resonances of a two-step magnetization reversal of the nanomagnets. The dynamic properties are consistent with topological defects that are provoked via a magnetic field applied at specific angles. Simulations that we performed on previously investigated kagome artificial spin ice consisting of isolated nanobars show characteristic discrepancies in the spin wave modes which we explain by the absence of vertices.Comment: 14 pages and 5 figure

If Chivalry Is Dead, Women Have Killed It

I am interested in the dual meaning of pattern. Pattern is a design format used for decoration. By introducing certain images into patterns, they have the ability to give meaning or messages. The repetition of a certain image emphasizes importance to a particular idea or issue. I embroider pattern designs onto pre-manufactured clothing pattern pieces as a response to things in society that I find absurd. This body of work focuses on female iconography. The delicate nature of these materials lends themselves to feminine associations. Embroidery, which is stereotypically associated with women\u27s work, is used to play on these clichés.Patterns also are instructions. The original intent for these pattern pieces was to construct a wearable garment. I am using these specifically shaped pieces to create flat representational images on the wall to point to the roles that people undertake consciously or unconsciously in their lives

Variability of thousand grain weights of seed batches of important arable and some horticultural crops

Das Tausendkorngewicht (TKG) von Saatgut variiert natürlicherweise zwischen Sorten und Saatgutchargen aber auch durch Größensortierungen bei Züchtern und Saatguterzeugern. Die Spanne von TKG-Werten von 55 verschiedenen landwirtschaftlichen Kulturen, 26 Gemüsekulturen sowie von 15 Kulturen mit pilliertem Saatgut werden präsentiert. Neben Mittelwerten, Minimal- und Maximalwerten, wurden auch Perzentilwerte berechnet. Für die Zusammenstellung wurden die TKG Werte von Saatgutchargen landwirtschaftlicher Kulturen, die beim Bundessortenamt zur Aussaat für die Sortenprüfung der Erntejahre 2011 bis 2018 kamen und von zumeist gartenbaulichen Kulturen genutzt, die in einer kommerziellen Saatgutbehandlungsanlage für den europäischen Markt behandelt wurden.The thousand grain weight (TGW) of seeds used for sowing varies because of natural mass variation within and between cultivars of a crop but also because of selection of sizes of seeds used for propagation by breeders and seed suppliers. The range of TGW data of 55 arable crops and 26 horticultural crops are presented as well as TGW data for 15 types of pelleted seeds of different crops. In addition to the mean and maximum and minimum values, different percentiles were calculated for most crops. This study presents TGW data of seed batches used for cultivar testing (most arable crops) as well as of seed lots used for seed coating with pesticides for the European market in the period of the harvesting years 2011–2018

Territorial Behavior of the Ozark Zigzag Salamander, Plethodon angusticlavius, Altered by Mode of Predator Cue and Sex of Intruder

Territorial defense in many species must be balanced with trade-offs in activities such as reproduction and predator avoidance. Adjusting behavior based on current assessments of predation risk and the cost of maintaining or gaining a territory is one way that individuals can balance trade-offs to maximize fitness. I conducted two experiments to determine how Ozark zigzag salamanders, Plethodon angusticlavius, adjust their territorial behavior-based predation risk. First, I tested whether male and female territorial intruders changed their competitive behavior according to whether predation risk is assessed via unimodal (chemical) or multimodal (chemical + physical) cues. Females and males responded differently to unimodal and multimodal cues with females generally responding similarly to all predator cues, and males responding to multimodal cues in an additive manner. Second, I determined whether predation risk affected competitive behavior differentially based on whether the intruder salamander was in a territory marked by a same-sex or different-sex residents. Overall, the territorial behavior of both male and female intruders was moderated by the presence of a predator, but the effect differed based on the sex of both the intruder and the resident salamander. The results of these two experiments suggest that P. angusticlavius salamanders adjust their territorial behavioral in the presence of predation risk based on the source of the information (unimodal vs multimodal cues) and the sex of nearby individuals (potential mates or competitors)

Investigation into the feasibility of a DNA based radiosensitive device

In this work, the application of deoxyribonucleic acid (DNA) as a radiosensitive detector material is investigated. The aim is to bridge a measurable physical quantity with the severity of radiation damages on the biochemical stage. Radiation damages, which are expressed in alterations of the molecular structure of the DNA, can influence the charge transport properties of the molecule. The electrical conductivity is therefore a measure for the magnitude of the radiation damage. DNA samples consist of a substrate material with gold electrodes of nano- or microscale dimensions and of DNA molecules contacted between these electrodes. Experiments were performed with two types of DNA samples. Lambda-DNA molecules of several micrometer length suspended in air and single DNA origami structures trapped via dielectrophoresis. Lambda-DNA samples were provided by San Diego State University. The samples are expected to have non-uniform conductivity values, due to differences in number and alignment of the DNA strands. Therefore, an exact quantitative analysis of the radiation effects might not be possible. Nevertheless, the effects of different radiation qualities were studied on these samples. Changes of conductivity were monitored in situ during irradiation. The experiments showed that the conductivity of DNA is indeed sensitive to radiation. For the application as a detector material, a quantitative relation between the amount of DNA damage and the change in conductivity needs to be established. Single DNA origami structures can be electrically contacted using dielectrophoretic trapping. Experiments were carried out to investigate whether samples can be produced which retain ohmic conductivity in dry conditions. This investigation was accompanied by molecular dynamics simulations of microhydrated, multilayered DNA molecules. These can give insight under which conditions the DNA molecules keep their regular helical structures. It was found that tightly packed multilayered structures were indeed much more stable than individual or loosely packed strands. However, stable helical structures as in the case of fully hydrated states, were still only achieved for very high hydration levels in the simulation. To further increase the resilience of the DNA origami structures, they were covered with a layer of poly-L-lysine (PLL). It has been shown in studies that PLL coatings stabilize DNA origami structures against buffers of low salt concentrations. Experiments with these samples showed ohmic conductivity in dry conditions. The measured resistance values were in the range of several megaohm. A frequently observed phenomenon was the local destruction of the substrate material and electrodes after DEP trapping. The destruction was the result of high electrical currents. This indicates that the DNA origami structures can possess even higher values of electrical conductivity. Therefore, experiments with current limitation during DEP trapping should be the subject of future experiments. The subsequent step would be to test the influence of different radiation qualities and doses on the conductivity of these samples.In dieser Arbeit wird die Anwendung von Desoxyribonukleinsäure als strahlensensitives Detektormaterial untersucht. Ziel ist es eine Verbindung zwischen einer messbaren physikalischen Größe und dem Ausmaß des Strahlenschadens auf der biochemischen Ebene zu finden. Strahlenschäden, welche sich durch Änderungen der molekularen Struktur der DNA äußern, können die Ladungstransporteigenschaften von DNA-Molekülen verändern. Die elektrische Leitfähigkeit kann daher als Maßstab für die Größe des Strahlenschadens genutzt werden. DNA-Proben bestehen aus einem Substrat mit Nano/Mikrometer messenden Goldelektroden und DNA-Molekülen, welche zwischen den Elektroden kontaktiert sind. Es wurden Experimente mit zwei Arten von DNA-Proben durchgeführt. Diese sind Lambda-DNA Moleküle von mehreren Mikrometern Länge, frei hängend kontaktiert, und einzelnen DNA-Origami Strukturen, welche mittels Dielektrophorese kontaktiert wurden. Die Lambda-DNA Proben wurden von der San Diego State University bezogen. Diese Proben haben meist uneinheitliche Leitfähigkeitswerte, da sie sich in der Anzahl und Ausrichtung der DNA-Moleküle unterscheiden können. Hierdurch ist eine quantitative Analyse der Strahleneffekte wahrscheinlich nicht möglich. Gleichwohl wurden die Effekte verschiedener Strahlenqualitäten an den DNA-Proben untersucht. Die Veränderung der Leitfähigkeit wurde in situ während der Bestrahlung gemessen. Die Versuche zeigen, dass die Leitfähigkeit von DNA tatsächlich sensitiv bezüglich Strahlung ist. Damit eine Anwendung als Detektormaterial möglich ist, muss noch eine quantitative Verbindung zwischen dem Ausmaß des DNA-Schadens und der Änderung der Leitfähigkeit gefunden werden. Einzelne DNA-Origami Strukturen können per dielektrophoretischem Einfang elektrisch kontaktiert werden. Es wurden Versuche durchgeführt, um zu untersuchen, ob so Proben hergestellt werden können, die in einer trockenen Umgebung eine ohmsche Leitfähigkeit aufweisen. Diese Untersuchungen wurden durch Molekulardynamik-Simulationen von mikrohydrierten, mehrlagigen DNA-Molekülen begleitet. Diese Simulationsrechnungen können helfen einen Einblick zu gewinnen, unter welchen Bedingungen die DNA-Moleküle ihre regelmäßige helikale Struktur behalten. Es wurde festgestellt, dass dicht gepackte, mehrlagige Strukturen tatsächlich deutlich stabiler waren als einzelne, oder lose gepackte Stränge. Jedoch wurden eine stabile helikale Struktur, wie sie im voll hydrierten Zustand auftritt, auch hier nur im Falle sehr hoher Hydrierungsgrade erreicht. Um die Widerstandsfähigkeit der DNA-Origami Strukturen weiter zu verbessern wurden diese mit einer Schicht aus poly-L-Lysin umhüllt. Es wurde in Studien gezeigt, dass PLL Schutzschichten DNA-Origami Strukturen in Pufferlösungen mit niedrigem Salzgehalt stabilisieren. Diese Proben zeigten in unseren Experimenten ohmsche Leitfähigkeiten in trockener Umgebung. Die gemessenen elektrischen Widerstandswerte bewegten sich im Bereich einiger Megaohm. Ein häufig beobachtetes Phänomen war die lokale Zerstörung von Substrat und Elektroden nach dem DEP Einfang. Diese wurde durch hohe elektrische Ströme hervorgerufen und weist darauf hin, dass die DNA-Origami Strukturen sogar noch höhere elektrische Leitfähigkeiten besitzen könnten. Daher soll in folgenden Experimenten den DEP Einfang dieser Strukturen mit begrenzter Stromstärke untersucht werden. Der darauffolgende Schritt wäre den Einfluss verschiedener Strahlenqualitäten auf die Leitfähigkeit dieser Proben zu testen