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

A queueing-theoretic analysis of the threshold-based exhaustive data-backup scheduling policy

We analyse the threshold-based exhaustive data backup scheduling mechanism by means of a queueing-theoretic approach. Data packets that have not yet been backed up are modelled by customers waiting for service (back-up). We obtain the probability generating function of the system content (backlog size) at random slot boundaries in steady state

Status quo und Akzeptanz von Internet-basierten Informationssystemen: Ergebnisse einer empirischen Analyse in der deutschen Veredelungswirtschaft

Seit Mitte der 1990er Jahre werden verschiedene Internet-basierte Informationssysteme für den überbetrieblichen Austausch von produkt- und prozessbezogenen Daten zwischen Landwirten und den vor- und nachgelagerten Wertschöpfungsstufen entwickelt. Obwohl die meisten IT-Lösungen inzwischen relativ leistungsfähig sind, bevorzugen Landwirte nach wie vor die traditionellen Kommunikationskanäle (Post, Fax etc.). Dieser Beitrag thematisiert daher die mangelnde Akzeptanz für Internet-basierte interorganisationale Informationssysteme auf Basis einer Befragung von 873 Schweineproduzenten. Die Grundlage für die statistische Analyse bildet ein exploratives Modell, in dem sowohl die aus der Akzeptanzforschung bekannten Erklärungsgrößen berücksichtigt als auch speziell auf interorganisationale Informationssysteme zugeschnittene Konstrukte untersucht werden. Die Validierung erfolgte anhand einer binär-logistischen Regressionsanalyse. Die Untersuchungsergebnisse zeigen, dass die Anwendung Internet-basierter Informationssysteme maßgeblich von der Intensität der vertikalen Koordination der Geschäftsbeziehungen zwischen Landwirten und Schlachtunternehmen beeinflusst wird. --

Enabling Normalized Systems in Practice – Exploring a Modeling Approach

Contemporary organizations are required to adapt to a changing environment in an agile way, which is often deemed very challenging. Normalized Systems (NS) theory attempts to build highly evolvable software systems by using systems theory as its theoretical underpinning. A modeling method which supports the identification of the NS elements, required for building NS sofware in practice, is currently missing. Therefore, the paper introduces an approach for creating both data models and processing models in the context of NS, as well as their integration. It is discussed how these models can be taken as the input for the actual creation of evolutionary prototypes by using an earlier developed supporting tool. The modeling approach and its suitability for feeding the tool are evaluated to discover their current strengths and weaknesses

Anti-erosion stone bunds influence rodent dynamics and crop damage in Ethiopian highlands

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Transcriptional response of Lactococcus lactis during bacterial emulsification

Microbial surface properties are important for interactions with the environment in which cells reside. Surface properties of lactic acid bacteria significantly vary and some strains can form strong emulsions when mixed with a hydrocarbon. Lactococcus lactis NCDO712 forms oil-in-water emulsions upon mixing of a cell suspension with petroleum. In the emulsion the bacteria locate at the oil-water interphase which is consistent with Pickering stabilization. Cells of strain NCDO712 mixed with sunflower seed oil did not stabilize the oil droplets. This study shows that the addition of either ethanol or ammonium sulfate led to cell aggregation, which subsequently allowed stabilizing oil-in-water emulsions. From this, we conclude that bacterial cell aggregation is important for emulsion droplet stabilization. To determine how bacterial emulsification influences the microbial transcriptome RNAseq analysis was performed on lactococci taken from the oil-water interphase. In comparison to cells in suspension 72 genes were significantly differentially expressed with a more than 4-fold difference. The majority of these genes encode proteins involved in transport processes and the metabolism of amino acids, carbohydrates and ions. Especially the proportion of genes belonging to the CodY regulon was high. Our results also point out that in a complex environment such as food fermentations a heterogeneous response of microbes might be caused by microbe-matrix interactions. In addition, microdroplet technologies are increasingly used in research. The understanding of interactions between bacterial cells and oil-water interphases is of importance for conducting and interpreting such experiments

Fermentability of whole oat flour, PeriTec flour and bran by Lactobacillus plantarum

4 páginas, 2 tablas, 1 figuraWhole oat flour obtained by hammer milling was fermented with Lactobacillus plantarum along with white flour and bran in order to compare the suitability of these substrates for the production of a probiotic beverage. The three substrates show a viable cell concentration at the end of fermentation above the minimum required in a probiotic product. The highest cell concentration was observed in white flour (9.16 Log10 CFU/mL) and the lowest in the bran sample (8.17 Log10 CFU/mL)Peer reviewe