Grossansätze zur Herstellung von α,α,α',α'-Tetraaryl-1,3-dioxolan-4,5-dimethanolen (TADDOLe): Nützliche Hilfsstoffe für die EPC-Synthese und ihre Struktur im Festkörper

The large-scale preparation of α,α,α',α'-tetraaryl-1,3-dioxolan-4,5-dimethanol derivatives is described. It consists of acetalization of dimethyl tartrate and Grignard addition. The diols 2–12 thus obtained are crystalline and stable. They are useful as versatile auxiliaries for enantioselective reactions and for resolutions by clathrate formation. The X-ray crystal structure of the inclusion compound from one of the TADDOLs and CCl4 is described (6·2 CCl4) and compared with the structures of analogous derivatives, including C2-symmetrical diphosphines. Reference is given to other chiral auxiliaries containing the diaryl-methanol group

Ceramic cells for high pressure NMR spectroscopy of proteins

Application of high pressure to biological macromolecules can be used to find new structural states with a smaller specific volume of the system. High pressure NMR spectroscopy is a most promising analytical tool for the study of these states at atomic resolution. High pressure quartz cells are difficult to handle, high quality sapphire high pressure cells are difficult to obtain commercially. In this work, we describe the use of high pressure ceramic cells produced from yttrium stabilized ZrO2 that are capable of resisting pressures up to 200 MPa. Since the new cells should also be usable in the easily damageable cryoprobes a completely new autoclave for these cells has been constructed, including an improved method for pressure transmission, an integrated safety jacket, a displacement body, and a fast self-closing emergency valve.DF

Welche Macht darf es denn Sein? Tracing ‘Power’ in German Foreign Policy Discourse

The relationship between ‘Germany’ and ‘power’ remains a sensitive issue. While observers tend to agree that Germany has regained the status of the most powerful country in Europe, there is debate whether that is to be welcomed or whether that is a problem. Underpinning this debate are views, both within Germany and amongst its neighbours, regarding the kind of power Germany has, or should (not) have. Against this backdrop, the article reviews the dominant role conceptions used in the expert discourse on German foreign policy since the Cold War that depict Germany as a particular type of ‘power’. Specifically, we sketch the evolution of three prominent conceptions (constrained power, civilian power, hegemonic power) and the recent emergence of a new one (shaping power). The article discusses how these labels have emerged to give meaning to Germany’s position in international relations, points to their normative and political function, and to the limited ability of such role images to tell us much about how Germany actually exercises power

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe

Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV

Peer reviewe

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe