Magnetic correlations of the quasi-one-dimensional half-integer spin-chain antiferromagnets SrM2M_2V2_2O8_8 (MM = Co, Mn)

Magnetic correlations of two iso-structural quasi-one-dimensional (1D) antiferromagnetic spin-chain compounds Sr$M_2$V$_2$O$_8$ ($M$ = Co, Mn) have been investigated by magnetization and powder neutron diffraction. Two different collinear antiferromagnetic (AFM) structures, characterized by the propagation vectors, $k$ = (0 0 1) and $k$ = (0 0 0), have been found below $\sim$ 5.2 K and $\sim$ 42.2 K for the Co- and Mn-compounds, respectively. For the Mn-compound, AFM chains (along the $c$ axis) order ferromagnetically within the $ab$ plane, whereas, for the Co-compound, AFM chains order ferro-/antiferromagnetically along the $a/b$ direction. The critical exponent study confirms that the Co- and Mn-compounds belong to the Ising and Heisenberg universality classes, respectively. For both compounds, short-range spin-spin correlations are present over a wide temperature range above $T_N$. The reduced ordered moments at base temperature (1.5 K) indicate the presence of quantum fluctuations in both compounds due to the quasi-1D magnetic interactions.Comment: 14 pages, 10 figures, 9 table

Computer-Aided Techniques as a Tool for the Integration of Industrial Processes

The main topics of this working paper are: (1) To roughly characterize the main processes of industrial systems by their essential features. (2) To point out the possibilities of rationalization of the main processes of industrial systems -- first of all by utilization of computers. (3) To sketch some methodological aspects of analysis and synthesis of industrial processes. (4) To recommend problems that could be investigated in IIASA in connection with the rationalization of Integrated Industrial Systems by utilization of computers. (5) To investigate the role of CAD techniques as a tool for the integration of industrial processes. The main objective of this working paper is to explain the problems and to fix the limits of the area to be discussed at the CAD conference at IIASA in November 1974. We shall not describe here state-of-the-art reports or solutions to the problems but will only point out the direction of possible research and various ideas which will be explained in some papers presented at the conference

Kommunikation von Naturschutzmaßnahmen in der ökologischen Direktvermarktung

The preservation of living ecosystems and the protection of nature and environment as a basis for existence are important challenges of our time, which are highlighted in the principles of the International Federation of Organic Agriculture Movements (IFOAM 2015). Since nature conservation measures within organic farming are often related to more costs, expenses or even yield losses, there are approaches to get the conservation efforts rewarded by the customers. The object of this research is the description of the communication of nature conservation measures on three organic farms with direct selling in Northern and Eastern Germany. Therefore, three guided interviews with the farm managers were conducted and analyzed. Afterwards, personally-written customer surveys using standardized questionnaires were carried out in the farm shops. The intensity of nature communication to consumers ranged from very low on farm1 to very high on farm3. It became clear that for many customers the engagement of the farms for nature conservation is an important factor to buy there. The combination of nature conservation and direct selling can lead to positive interactions, e.g. by emphasizing the authenticity of organic farming. Under certain conditions nature conservation can be used as a unique selling proposition and by that enhancing customer loyalty and willingness to pay

FCP

Farmer Consumer Partnerships

Concept-Development of a Structure Supported Membrane for Deployable Space Applications - From Nature to Manufacture and Testing

Current space applications of membrane structures include large area solar power arrays, solar sails, antennas, and numerous other large aperture devices like the solar shades of the new James Webb Space Telescope. These expandable structural systems, deployed in-orbit to achieve the desired geometry, are used to collect, reflect and/or transmit electromagnetic radiation. This work, a feasibility study supporting a diploma thesis, describes the systematic process for developing a biologically inspired concept for a structure supported (integrated) membrane, that features a rip stop principle, makes self-deployment possible and is part of an ultra-light weight space application. Novel manufacturing of membrane prototypes and test results are presented for the rip-stop concepts. Test data showed that the new membrane concept has a higher tear resistance than neat film of equivalent mass