Linearly polarised photon beams at ELSA and measurement of the beam asymmetry in pi^0-photoproduction off the proton

At the electron accelerator ELSA a linearly polarised tagged photon beam is produced by coherent bremsstrahlung off a diamond crystal. Orientation and energy range of the linear polarisation can be deliberately chosen by accurate positioning of the crystal with a goniometer. The degree of polarisation is determined by the form of the scattered electron spectrum. Good agreement between experiment and expectations on basis of the experimental conditions is obtained. Polarisation degrees of P = 40% are typically achieved at half of the primary electron energy. The determination of P is confirmed by measuring the beam asymmetry, \Sigma, in pi^0 photoproduction and a comparison of the results to independent measurements using laser backscattering.Comment: 9 pages, 10 figures, submitted to EPJ

Semantically Reconnecting Fragmented Information through User Activity Monitoring

Today information items on user’s workstations are usuallystored in separate collections depending on their format.This results in a disconnect between information systemsand user needs leading to high lookup times during task relatedinformation retrieval. This paper presents an approachto reduce document based information fragmentation by semanticallyreconnecting electronic documents to each otherwithout imposing additional training or tagging workloadon the user. To this end the actions knowledge workers performon their desktop are transparently monitored to analyzethe user’s interaction with his computer system. Theseaction metadata are further clustered by superordinate activitiesperformed by the user. Finally documents attachedto window instances within the identified activity clustersare semantically to each other related reducing the fragmentationof their contained information. This allows a subsequentassociative information discovery navigating from onedocument instance to other related document instances. Aprototypical implementation and evaluation in a small scaletesting setup indicates the validity of the approach

CCDC 1838409: Experimental Crystal Structure Determination

Related Article: Niels J. C. van Velzen, Sjoerd Harder|2018|Organometallics|37|2263|doi:10.1021/acs.organomet.8b00254,An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

CCDC 1838411: Experimental Crystal Structure Determination

Related Article: Niels J. C. van Velzen, Sjoerd Harder|2018|Organometallics|37|2263|doi:10.1021/acs.organomet.8b00254,An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

CCDC 893202: Experimental Crystal Structure Determination

Related Article: Julia Intemann, Jan Spielmann, Peter Sirsch, Sjoerd Harder|2013|Chem.-Eur.J.|19|8478|doi:10.1002/chem.201300684,An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

CCDC 893203: Experimental Crystal Structure Determination

Related Article: Julia Intemann, Jan Spielmann, Peter Sirsch, Sjoerd Harder|2013|Chem.-Eur.J.|19|8478|doi:10.1002/chem.201300684,An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

CCDC 893204: Experimental Crystal Structure Determination

Related Article: Julia Intemann, Jan Spielmann, Peter Sirsch, Sjoerd Harder|2013|Chem.-Eur.J.|19|8478|doi:10.1002/chem.201300684,An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

CCDC 1008317: Experimental Crystal Structure Determination

Related Article: Julia Intemann, Heiko Bauer, Jürgen Pahl, Laurent Maron, Sjoerd Harder|2015|Chem.-Eur.J.|21|11452|doi:10.1002/chem.201501072,An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Precise determination of graphene functionalization by in situ Raman spectroscopy

The verification of a successful covalent functionalization of graphene and related carbon allotropes can easily be carried out by Raman spectroscopy. Nevertheless, the unequivocal assignment and resolution of individual lattice modes associated with the covalent binding of addends was elusive up to now. Here we present an in situ Raman study of a controlled functionalization of potassium intercalated graphite, revealing several new bands appearing in the D-region of the spectrum. The evolution of these bands with increasing degree of functionalization from low to moderate levels provides a basis for the deconvolution of the different components towards quantifying the extent of functionalization. By complementary DFT calculations we were able to identify the vibrational changes in the close proximity of the addend bearing lattice carbon atoms and to assign them to specific Raman modes. The experimental in situ observation of the developing functionalization along with the reoxidation of the intercalated graphite represents an important step towards an improved understanding of the chemistry of graphene.© The Author(s) 201