Different types of economies within the LBK settlement Erkelenz-Kückhoven

Around 5300 BC the first farmers (Linear Pottery Culture) reached the Rhineland. In the region of the Aldenhovener Platte, Rhineland, a complex system of raw material exchange was proposed by A. Zimmermann (1995) in which main settlements (distributors) passed on cores, blades and final products to secondary and single farmstead settlements (receivers). With reference to the Early Neolithic settlement Erkelenz-Kückhoven, this paper sets out to demonstrate that similar processes, resembling a “receiver/distributor- settlement”-pattern, actually occurred within individual settlements. It is likely that these resulted from different social units within the settlement. The results were obtained in the course of a MA-thesis at the University of Cologne in 2005

Bis(benzyl­trimethyl­ammonium) di-μ-bromido-bis­[dibromido­mercurate(II)]

In the crystal structure of the title compound, (C10H16N)2[Hg2Br6], the condensed anion consists of two edge-sharing HgBr4 tetrahedra and is situated on a centre of symmetry. The anions are linked to the cations through weak C—H⋯Br inter­actions

Alternative Approaches to the Validation of Nondestructive Testing Methods

There is currently considerable interest in devising appropriate means for measuring how well test methods suit their avowed purpose. One of the major expressions of this interest has been through implementation of standards and guidelines issued by ISO/IEC (International Organization for Standardization/International Electrotechnical Commission) and, in Europe, CEN/CENELEC (European Committee for Standardization/European Commission for Electrotechnical Standardization). Among the goals of the ISO 9000 family of International Standards is provision of quality system guidelines [1] to complement the specific product requirements that are typically incorporated in specifications provided by “customers”. These criteria are intended to aid “suppliers” in achieving continuing improvements in product quality and customer satisfaction. Four key “facets of quality” are identified, associated with a) definition of needs for the product; b) aspects of product design that influence performance of the product; c) consistency in conforming to the product design; and d) providing life-cycle product support

Temperature dependence of the electrical conductivity of imidazolium ionic liquids.

The electrical conductivities of 1-alkyl-3-methylimidazolium tetrafluoroborate ionic liquids and of 1-hexyl-3-methylimidazolium ionic liquids with different anions were determined in the temperature range between 123 and 393 K on the basis of dielectric measurements in the frequency range from 1 to 10^7 Hz. Most of the ionic liquids form a glass and the conductivity values obey the Vogel-Fulcher-Tammann equation. The glass transition temperatures are increasing with increasing length of the alkyl chain. The fragility is weakly dependent on the alkyl chain length but is highly sensitive to the structure of the anion.ionic liquids; molten salts;

An introduction to zwitterionic salts

International audienceZwitterionic salts are hybrid materials, incorporating some characteristics of zwitterions and of ionic liquids, e.g. numerous options for structural design and functionalisation. They are comprised of cations and anions in which an additional zwitterionic moiety is embedded into either the cation or the anion. Such materials are characterised by having extended polar domains and high hydrophilicity. Here, we present results from the study of novel zwitterionic salts that are representative examples of this class of materials and illustrate the potential to exploit their functionalities and high hydrophilicity

μ3-Oxido-tris­{dichlorido[1,3-bis­(1,3,5-trimethyl­phen­yl)imidazol-2-yl­idene]gold(III)} bis­(trifluoro­methane­sulfon­yl)imide–[bis­(trifluoro­methane­sulfon­yl)imide]­silver(I) (1/2)

The unusual trinuclear AuIII oxide title complex, [Au3Cl6O(C21H24N2)3](C2F6NO4S2)·2[Ag(C2F6NO4S2)], is the side product of the reaction of [1,3-bis­(1,3,5-trimethyl­phen­yl)imidazol-2-yl­idene]dichloridophenyl­gold(III) with silver bis­(trifluoro­methane­sulfon­yl)imide in the presence of traces of water. In contrast to corresponding AuI complexes, the core structure of the title compound is planar. Two silver(I) bis­(trifluoro­methane­sulfon­yl)imide units are loosely bound to the complex cation. Here the silver atoms, disordered over two positions in a 0.870 (2):0.130 (2) ratio, inter­act either with the lone pairs of three chlorine ligands or two chlorine ligands and one edge of the mesityl π-system. The crystal under investigation was a partial racemic twin

Tris(1-ethyl-3-methyl­imidazolium) hexa­bromidoeuropate(III)

The crystal structure of the title compound, (C6H11N2)3[EuBr6], consists of 1-ethyl-3-methyl­imidazolium cations and centrosymmetric octa­hedral hexa­bromido­europate anions. The [EuBr6]3− anions are located at the corners and face-centres of the monoclinic unit cell. Characteristic hydrogen-bonding inter­actions can be observed between the bromide anions and the acidic H atoms of the imidazolium cations