Optische Systeme im Phasenraumbild

Optical Microcavities are established model systems for non-linear dynamics. This motivates their description in phase space using Husimi-Functions, which give insight into the main radiation directions and the mode distribution at the dielectric interface. In this work, we generalize the application of Husimi-Functions to coupled microcavity systems

Resonant diffraction gratings with polarization-dependent efficiencies

Subwavelength-structures with different fill factors in the lateral dimensions result in unique phase shifts for the different polarization states of transmitted light.By using this additional degree of freedom for diffractive optical elements, we yield additional functionalities for compact optical systems with DOEs. As a fully operable example we present a binary subwavelength-grating which acts as a polarizing beamsplitter for TE- and TM-polarization over a wide range of incidence angles. We show our design approach, the manufacturing process with Soft-UV-Nanoimprint-Technology, as well as experimental results. We will also lay out possibilities for the design and application of multilevel polarization-functionalized gratings

Advective timescales and pathways of Agulhas leakage

Current research indicates an increase in Agulhas leakage for the past and coming decades. This change potentially alters the strength of the Atlantic meridional overturning circulation, in particular, through advection of positive density anomalies into the North Atlantic. To explore the fate of Agulhas leakage, results from a Lagrangian analysis were evaluated, with virtual floats advected within an eddy-permitting ocean model (ORCA025). A considerable fraction of Agulhas leakage reached the subtropical North Atlantic: of a mean Agulhas leakage transport of 15.3 Sv entering the South Atlantic, 9.7, 7.7, and 6.1 Sv crossed sections at 6 degrees S, 6 degrees N, and 26 degrees N, respectively. The most probable transit time of leakage to reach the respective latitudes is one to two decades. We suggest that changes in Agulhas leakage could manifest in the Gulf Stream regime most probably within two decades. These results were supported by an eddy-resolving implementation of the ocean model (INALT01

Nano-imprinted subwavelength gratings as polarizing beamsplitters

Polarizing beamsplitters have numerous applications in optical systems, such as systems for freeform surface metrology. They are classically manufactured from birefringent materials or with stacks of dielectric coatings. We present a binary subwavelength-structured form-birefringent diffraction grating, which acts as a polarizing beamsplitter for a wide range of incidence angles -30°…+30°. We refine the general design method for such hybrid gratings. We furthermore demonstrate the manufacturing steps with Soft-UV-Nanoimprint-Lithography, as well as the experimental verification, that the structure reliably acts as a polarizing beamsplitter. The experimental results show a contrast in efficiency for TE- and TM-polarization of up to 1:18 in the first order, and 34:1 in the zeroth order. The grating potentially enables us to realize integrated compact optical measurement systems, such as common-path interferometers

A ToxR-based two-hybrid system for the detection of periplasmic and cytoplasmic protein-protein interactions in Escherichia coli: minimal requirements for specific DNA binding and transcriptional activation

The Vibrio cholerae transcriptional regulator ToxR is anchored in the cytoplasmic membrane by a single transmembrane segment, its C-terminal domain facing the periplasm. Most of its N-terminal cytoplasmic domain shares sequence similarity with the winged helix-turn-helix (wHTH) motif of OmpR-like transcriptional regulators. In the heterologous host Escherichia coli ToxR activates transcription at the V.cholerae ctx promoter in a dimerization-dependent manner, which has led to its employment as a genetic indicator for protein-protein interactions. However, although offering a broader potential application range than other prokaryotic two-hybrid systems described to date, ToxR has so far only been used to study interactions between heterologous transmembrane segments or to monitor homodimerization of C-terminal fusion partners in the periplasm and the cytoplasm of E.coli. Here we show that the ToxR-system also allows the detection of heterodimerization in both cellular compartments of E.coli. In addition, to better understand ToxR's mode of action at ctx in E.coli, we have investigated the minimal requirements for its function as a transcriptional activator. We show that the wHTH motif of ToxR's N-terminal domain constitutes the minimal structural element required to activate transcription at ctx in E.coli when fused to a dimerizing protein modul

Simulation of Automated File Migratoon in Information Lifecycle Management

Information Lifecycle Management (ILM) is a strategic concept for storage of information and documents. ILM is based on the idea that in an enterprise information have different values. Information with different values are stored on different storage hierarchies. ILM offers significant potential cost savings by tiering storage and 90% of decision makers consider implementing ILM (Linden 2006). Nonetheless, there are too few experience reports and experimenting and researching in real systems are too expensive. This paper addresses this issue and contributes to supporting and assisting IT managers in their decision-making process. ILM automation needs migration rules. There are well-known static, heuristic migration rules and we present a new dynamic migration rule for ILM. These migration rules are implemented in an ILM simulator. We compare the performance of the new dynamic rule with the heuristics. The simulative approach has two advantages. On the one hand it offers predictions about the dynamic behaviour of an ILM migration rule and, on the other hand, it dispenses with real storage hardware. Simulation leads to decisions under certainty. When making a decision under certainty, the major problem is to determine which is the trade-off among different objectives. Cost-benefit analysis can be used to this purpose. A decision matrix is laid where rows represent choices and columns represent states of nature. The simulated results support the choice of migration rules and help to avoid mismanagement and poor investments in advance. The results raise the awareness of choosing the best alternative

Composition and variability of the Denmark Strait Overflow Water in a high-resolution numerical model hindcast simulation

Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 122 (2017): 2830–2846, doi:10.1002/2016JC012158.The upstream sources and pathways of the Denmark Strait Overflow Water and their variability have been investigated using a high-resolution model hindcast. This global simulation covers the period from 1948 to 2009 and uses a fine model mesh (1/20°) to resolve mesoscale features and the complex current structure north of Iceland explicitly. The three sources of the Denmark Strait Overflow, the shelfbreak East Greenland Current (EGC), the separated EGC, and the North Icelandic Jet, have been analyzed using Eulerian and Lagrangian diagnostics. The shelfbreak EGC contributes the largest fraction in terms of volume and freshwater transport to the Denmark Strait Overflow and is the main driver of the overflow variability. The North Icelandic Jet contributes the densest water to the Denmark Strait Overflow and shows only small temporal transport variations. During summer, the net volume and freshwater transports to the south are reduced. On interannual time scales, these transports are highly correlated with the large-scale wind stress curl around Iceland and, to some extent, influenced by the North Atlantic Oscillation, with enhanced southward transports during positive phases. The Lagrangian trajectories support the existence of a hypothesized overturning loop along the shelfbreak north of Iceland, where water carried by the North Icelandic Irminger Current is transformed and feeds the North Icelandic Jet. Monitoring these two currents and the region north of the Iceland shelfbreak could provide the potential to track long-term changes in the Denmark Strait Overflow and thus also the AMOC.Norwegian Research Council Grant Number: 2316472017-10-0

Plasma processes to detect fluorine with ICPMS as M-F+ : an argument for building a negative mode ICPMS/MS

NLAJ thanks the Malaysian Government (Grant number: RG12824-10) and National Defence University of Malaysia for financial support throughout the study period, while AB thanks the Erasmus programme of the EU. Special thanks to Swedish Research Council for additional financial support (Grant number: FORMAS 1397306) and also to Samira Al Hinai and Amanda Victor for helping in this project.Peer reviewedPostprin