This way and that: Ruthenium complexes with asymmetric bidentate phosphine ligands bearing two substituents that differ in size (green spheres) produce a totally alternating copolymer of norbornene and cyclooctene by ring-opening metathesis polymerization (ROMP). The E/Z ratio can be influenced systematically by changing the bulkiness of the aryl sulfonate ligand (blue rectangles).

We have recently published a mechanistic concept for the olefin metathesis reaction with ruthenium catalysts that explains the independent control of chemo- and stereoselectivity by substitution in two orthogonal planes. The basic structure from which we started the structural modifications for improved stereoselectivity had been optimized substantially for chemoselectivity, as compared to the prototype that had been published. We designed the catalyst according to a concept in which the factor that governs alternation is directly related to the size difference of the substituents on the bidentate phosphine/phenolate ligand 2a-e and in which the origin of chemoselectivity arises from diastereomeric site control. The most selective catalyst (11d) outperforms our prototype (3) in selectivity as well as reactivity. Synthetic problems, i.e., the undesired formation of 2:1-complexes (bidentate ligand-to-ruthenium ratio) (8) by reaction of the bidentate phosphine/phenolate ligands 2a and 2b with the first-generation Floveyda-Grubbs catalyst 4, were solved by introduction of a larger carbene unit, which not only favors the formation of 1:1-complexes but also results in increased initiation rates. The work is supported by NMR data and X-ray crystallography, which give insights into the steric properties of the investigated system.

AbstractIn this work we have investigated viscous flow in a rotating system. The system consists of a horizontally oriented cylindrical drum rotating around the center and a fixed plate as a scraping internal tool. By this plate the inner volume is divided into two separate chambers. No mass transport between the chambers can take place. The drum is completely or partially filled with a highly viscous, optically transparent silicon oil. In the second case the remaining space is filled with air as a passive phase. Depending on the settings in the system, which are the rotational speed of the drum, material properties of the liquid and the volume ratio of the two phases, different flow phenomena can be observed [1, 2]. For the characterization of the flow dimensionless ratios given by the Reynolds number Re, the Froude number Fr, the Capillary number Ca and the volumetric filling degree F are used. The system is investigated applying the experimental method of Particle Image Velocimetry (PIV) as well as suitable models of Computational Fluid Dynamics (CFD). The goal of this investigation is to identify the velocity fields in the liquid phase for a better understanding of the observed phenomena. The results obtained by the different methods are presented and discussed. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)

The paper focuses on the role academic organizations and their members play within their socio-economic and socio-political contexts. It presents findings of the case study of a German university. Based on qualitative interviews, written documents and bibliometric analyses, we can see that, first, most of the university's links to the economy, political actors, and broader civil society emerge in a bottom-up and decentralized way, and they thrive on individual motivation and commitment. Therefore, there are clear limits to the formal institutionalization of such activities at the organizational level. Second, while ties to industry pay off at least indirectly through research funding, links to regional policy-making and broader civil society remain largely unrewarded in academia. For the future, we expect a growing tension between the organizational goal to embrace additional goals and the individual goals, especially of younger researchers who increasingly tend to focus on those activities that are rewarded in academia.

In this paper we describe a LIDAR‐based navigation approach applied at both the C‐Elrob (European Land Robot Trial) 2007 and the 2007 DARPA Urban Challenge. At the C‐Elrob 2007 the approach was used without any prior knowledge about the terrain and without global positioning system (GPS). At the Urban Challenge the approach was combined with a GPS‐based path follower. At the core of the method is a set of “tentacles” that represent precalculated trajectories defined in the ego‐centered coordinate space of the vehicle. Similar to an insect's antennae or feelers, they fan out with different curvatures discretizing the basic driving options of the vehicle. We detail how the approach can be used for exploration of unknown environments and how it can be extended to combined GPS path following and obstacle avoidance allowing safe road following in case of GPS offsets. © 2008 Wiley Periodicals, Inc.

The aim of this paper is to examine changing discursive conceptualizations of technology transfer mechanisms for speeding up innovation in Germany and the US since World War II with particular emphasis on universities. According to our analysis, the concepts of technology transfer are getting more and more complex, taking off from a linear model of innovation to a more complex model allowing for networking and entrepreneurial activities of the universities themselves. We suggest that the discourses in both countries can be framed employing three ideal-typical models: the information and documentation model, the cooperation model, and the blurring of boundaries model. In addition to these similarities, we also discuss differences that can be traced back to broader political cultures in which technology transfer is embedded. Both similarities and differences allow for a comparative perspective which is not limited to the countries analyzed here.

Via Mineralia is a serious pervasive game with the goal of transporting information in a playful manner to visitors of a minerals exposition. While in competitive pursuit of points for the search of and the answering of knowledge questions about exhibits they get to explore the museum in a guided fashion. First evaluations showed that especially for younger visitors this is a very promising approach for conveying information that might otherwise be regarded as unattractive or dry.