Frequency Coupling in Inverter Grids Modeling the Mutual Interference of Voltage Source Inverters in Island Grids

This paper presents a model to describe the mutual frequency disturbance of meshed and interconnected voltage source inverters during transient phases. The model provides a weighted mutual frequency coupling matrix taking into account that the mutual frequency measurement disturbance decreases for increasing electric distance between the inverters (i.e. depend on the line admittance) and depends on the respective inverter’s rated power, meaning that stronger inverters have more influence than small ones on the other inverters frequency perception

NetPower DemoLab A Test Bed Infrastructure for Security and Reliability Investigations of SCADA Systems

The purpose of this paper is to present the capabilities of the new NetPower DemoLab of the Interdisciplinary Centre for Reliability and Trust at the University of Luxembourg, operated by the Systems and Control group, and to stimulate potential public or private collaborations in the area of SCADA security and reliability investigations

First occurrence of western corn root worm beetles in the federal states Hesse and Rhineland-Palatinate (Germany), 2011

In 2011, western corn root worm beetles were detected in the federal states Hesse (Groß-Gerau) and Rhineland-Palatinate (Bodenheim) for the first time. Control measures based on commission decision 2003/766/EG (Byrne, 2003) were conducted after detection in PAL-traps. Focus and safety zones were established. In Hesse, both focus and safety zones were treated with the insecticide Biscaya, due to the high number of 50 beetles which were detected in the PAL-traps. Since in Rhineland-Palatinate, only one beetle had been captured, only the focus zone was treated with the insecticide. After insecticide treatment, new PAL-traps were arranged like a close grid over the infested areas in both federal states. In each maize field in the focus- and safety zone further traps were placed and checked weekly until September 30th by supporting staff. Until the end of the monitoring in 2011 (September 30th) further beetles were detected in the south of the area (district of Groß-Gerau, Hesse), were the first infestation had been discovered. However, in Rhineland-Palatinate no further beetles were detected that year. By the end of the monitoring 354 beetles in Hesse and one beetle in Rhineland-Palatinate had been captured in total. Subsequently the demarked zones in Hesse were extended. Taking into account the local circumstances, the new focus zone was delimited to include all the areas where beetles had been detected as well as the surrounding maize fields. In the focus zones the cultivation of maize was forbidden for the consecutive two years and a crop rotation with at least 50 percent maize was established in the safety zones. In 2012 no further beetles were captured in the infested region.Key words: Diabrotica virgifera virgifera LeConte, first occurrence, Hesse, Rhineland-Palatinate, eradicationErstauftreten des Westlichen Maiswurzelbohrers in den Bundesländern Hessen und Rheinland-Pfalz (Deutschland), 2011ZusammenfassungDer Westliche Maiswurzelbohrer (Diabrotica virgifera virgifera LeConte) trat in den Bundesländern Hessen (Groß-Gerau) und Rheinland-Pfalz (Bodenheim) erstmalig im Jahr 2011 auf. Die in der Kommissions-Entscheidung 2003/766/EG vorgeschriebenen Bekämpfungsmaßnahmen (Byrne, 2003) wurden umgehend durchgeführt. Befalls- und Sicherheitszonen wurden eingerichtet. In Hessen wurde wegen der hohen Zahl von 50 gefangenen Käfern sowohl die Befalls- als auch die Sicherheitszone mit dem Insektizid Biscaya behandelt. Da in Rheinland-Pfalz nur ein Käfer gefunden wurde, ist hier ausschließlich die Befallszone mit dem Insektizid behandelt worden. Im Anschluss an die Insektizidbehandlung wurden PAL-Fallen in den Befallsgebieten beider Länder engmaschig platziert- in jedem Maisfeld wurden PAL-Fallen aufgehängt. Alle Fallen wurden bis zum 30. September 2011 wöchentlich durch zusätzlich eingestellte Hilfskräfte kontrolliert. Bis zum Ende des Monitorings wurden südlich von Groß-Gerau, dem Ort des Erstfundes, weitere Käfer gefunden, sodass in Hessen insgesamt 354 Käfer festgestellt worden sind. Auf Rheinland-Pfälzischer Seite sind keine Käfer mehr hinzu gekommen. Die hessische Befallszone wurde unter Berücksichtigung der örtlichen Verhältnisse so ausgeweitet, dass alle Befallsstandorte einschließlich der umliegenden Nachbarmaisflächen eingeschlossen waren. Als Auflage darf in den Befallszonen beider Länder in den Jahren 2012 und 2013 kein Mais angebaut werden. In den Sicherheitszonen darf kein Mais nach Mais folgen. Im Jahr 2012 traten in den Befallsgebieten der Länder Rheinland Pfalz und Hessen, in denen 2011 Maiswurzelbohrer festgestellt wurde, keine Käfer mehr auf.Stichwörter: Maiswurzelbohrer, Erstauftreten, Hessen, Rheinland-Pfalz, Ausrottun

Single chain Fab (scFab) fragment

BACKGROUND: The connection of the variable part of the heavy chain (VH) and and the variable part of the light chain (VL) by a peptide linker to form a consecutive polypeptide chain (single chain antibody, scFv) was a breakthrough for the functional production of antibody fragments in Escherichia coli. Being double the size of fragment variable (Fv) fragments and requiring assembly of two independent polypeptide chains, functional Fab fragments are usually produced with significantly lower yields in E. coli. An antibody design combining stability and assay compatibility of the fragment antigen binding (Fab) with high level bacterial expression of single chain Fv fragments would be desirable. The desired antibody fragment should be both suitable for expression as soluble antibody in E. coli and antibody phage display. RESULTS: Here, we demonstrate that the introduction of a polypeptide linker between the fragment difficult (Fd) and the light chain (LC), resulting in the formation of a single chain Fab fragment (scFab), can lead to improved production of functional molecules. We tested the impact of various linker designs and modifications of the constant regions on both phage display efficiency and the yield of soluble antibody fragments. A scFab variant without cysteins (scFabΔC) connecting the constant part 1 of the heavy chain (CH1) and the constant part of the light chain (CL) were best suited for phage display and production of soluble antibody fragments. Beside the expression system E. coli, the new antibody format was also expressed in Pichia pastoris. Monovalent and divalent fragments (DiFabodies) as well as multimers were characterised. CONCLUSION: A new antibody design offers the generation of bivalent Fab derivates for antibody phage display and production of soluble antibody fragments. This antibody format is of particular value for high throughput proteome binder generation projects, due to the avidity effect and the possible use of common standard sera for detection

Numerical Investigations of Mixed Convection of Incompressible Viscous Fluid in LNG Storage with a Various Locations of Input and Output Mass

The article shows the results of mathematical simulation of mixed convection in the low-temperature storage of liquefied natural gas with a regenerative cooling. The regimes of mixed convection in a closed area with the different arrangement of the input and output sections of the masses are investigated. Two-dimensional nonstationary problem in the model of the Navier-Stokes in dimensionless variables "vorticity - stream function - temperature" was examined. Are obtained distributions of the hydrodynamic parameters and temperatures, characteristic basic laws governing the processes being investigated. Detailed circulating currents and carried out analysis of the mechanism of vortices formation and the temperature distribution in the solution for mixed convection mode with low Reynolds and Grashof numbers (Gr=10{6}, 100<Re<1000). Is established the significant influence of the geometrical arrangement of the input and output mass sections and input stream velocity on the structure of liquid flow and temperature in the low temperature LNG storage tanks

Tools and methods for providing assurance of clonality for legacy cell lines

Over the last several years demonstration of cell line clonality has been a topic of many industry and regulatory presentations and papers. Guidance has been provided by the regulatory authorities, especially the FDA, on a path forward for providing evidence of clonality with high probability. It has been recommended that two-rounds of limiting dilution cloning (LDC) at sufficiently low seeding densities (≤0.5 cells/well) provides sufficient evidence that a cell line is clonal. Furthermore, one-round of LDC may also suffice if supplemental data from a characterized FACS or plate-imaging workflow are also included in the package. Cell lines generated by methods that do not demonstrate high probability of clonal derivation, including legacy cell lines, may require additional studies to provide assurance and/or process control strategies to satisfy regulatory expectations. Within the Biologics function of the IQ Consortium the “Clonality” Working Group is focusing on methods and tools which could be utilized to provide a high assurance of clonality for legacy cell lines. The presentation will outline a three tier approach to address legacy cell line clonality assurance: standard practices already used in industry to support limit of in vitro cell age studies, enhanced control strategies to ensure process consistency, and emerging technologies that could be used to further support cell line clonality

Alternative-splicing-based bicistronic vectors for ratio-controlled protein expression and application to recombinant antibody production

In the last decade polycistronic vectors have become essential tools for both basic science and gene therapy applications. In order to co-express heterologous polypeptides, different systems have been developed from Internal Ribosome Entry Site (IRES) based vectors to the use of the 2A peptide. Unfortunately, these methods are not fully suitable for the efficient and reproducible modulation of the ratio between the proteins of interest. Here we describe a novel bicistronic vector type based on the use of alternative splicing. By modifying the consensus sequence that governs splicing, we demonstrate that the ratio between the synthesized proteins could easily vary from 1 : 10 to 10 : 1. We have established this system with luciferase genes and we extended its application to the production of recombinant monoclonal antibodies. We have shown that these vectors could be used in several typical cell lines with similar efficiencies. We also present an adaptation of these vectors to hybrid alternative splicing/IRES constructs that allow a ratio-controlled expression of proteins of interest in stably transfected cell lines