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Krasnov V.M.,Albanova University Center | Katterwe S.-O.,Albanova University Center | Katterwe S.-O.,Institute For Luft Und Kaltetechnik Gemeinnutzige Gesellschaft Mbh | Rydh A.,Albanova University Center
Nature Communications | Year: 2013

Understanding the pairing mechanism that gives rise to high-temperature superconductivity is one of the longest-standing problems of condensed-matter physics. Almost three decades after its discovery, even the question of whether or not phonons are involved remains a point of contention to some. Here we describe a technique for determining the spectra of bosons generated during the formation of Cooper pairs on recombination of hot electrons as they tunnel between the layers of a cuprate superconductor. The results obtained indicate that the bosons that mediate pairing decay over micrometre-scale distances and picosecond timescales, implying that they propagate at a speed of around 10 6 m s-1. This value is more than two orders of magnitude greater than the phonon propagation speed but close to Fermi velocity for electrons, suggesting that the pairing mechanism is mediated by unconventional repulsive electron-electron, rather than attractive electron-phonon, interactions. © 2013 Macmillan Publishers Limited.

Junk M.,Institute For Luft Und Kaltetechnik Gemeinnutzige Gesellschaft Mbh
Tribologie und Schmierungstechnik | Year: 2010

Mixtures of lubricants with refrigerants often show a behaviour which differs significantly from those of the pure lubricants. It concerns not only physical and thermodynamical properties like density, viscosity and thermal conductivity but also tribological properties. The tribological properties depend not only on viscosity of the mixtures but are influenced by several effects like misciblity, decomposition of lubricant and refrigerants and compatibility of refrigerants both with base oil and additives as well as compatibility of the mixture with materials used. Tribological investigations of oil-refrigerant mixtures are carried out as accompanying tests for lubricant and refrigerant development, for selection of specific oils for refrigeration applications, and for failure analysis. In the Institut für Luft- und Kältetechnik gGmbH Dresden a modified Almen-Wieland wear testing machine is used for the investigation of tribological properties of lubricant-refrigerant mixtures. The hermetic test cell of this wear tester allows testing under increased refrigerant pressure. The article gives a short survey of the possibilities and limits of tribological investigations of lubricant-refrigerant mixtures.

Schmalzm E.,Sachsiches Textilforschungsinstitut E V | Heidenreich R.,Institute For Luft Und Kaltetechnik Gemeinnutzige Gesellschaft Mbh | Rudolph H.,Forschungsinstitut For Leder Und Kunststoffbahnen
Kettenwirk-Praxis | Year: 2011

The use of biomasses in small incineration plants for the purposes of heating will increase in the future. Emissions from incineration plants must be decreased in order to comply with the requirements of environmental protection. As far as total emissions from boiler plants are concerned, it is also important for the filter system to have a low resistance and thus to influence the pressure conditions in the boiler. In this case, new filter materials have to be developed. The current research work has enabled the requirements relating to the air permeability to be met. Extensive investigations were carried out into the chemical resistance of the fibres, and the best materials were selected on the basis of the results. The filtration studies carried out on filter media based on pile-fibre stitch-bonded nonwovens resulted in low pressure differences for very different filtration performances. The majority of the textile materials did not achieve the target values for dust concentration levels in the clean gas. However, the results do give an indication of the possibilities and the direction that the development work should take. One of the filter materials produced has already achieved a filtration efficiency of above 95%.

Agency: Cordis | Branch: FP7 | Program: BSG-SME | Phase: SME-2011-1 | Award Amount: 1.17M | Year: 2011

AtexDeDust is a partnership of European SMEs that have identified a promising new design and functionality for air cleaning systems in industrial scale. The proposal addresses dust/air systems according to the ATEX Directive for systems with hazard of explosive atmospheres as well as standard applications in a wide range of production lines. Especially we focus on smart, mobile instrumentation to meet the demands of modern production management. This new technology will guarantee safe air pollution control inside production estates and in the output to environment for a wide size of particulate in air and gases. It overcomes the risks of potential explosive atmospheres of dust concentration inside the housing during the periodic regeneration process of the filter elements. Though it allows mobile instrumentation in smarter size, supply with common electric and electronic components and a better filtration performance compared to the state of the art. One main feature to reach this objectives is the use of a improved textile filter material with mani-fold air permeability. This succeed in a diminishing of the pressure loss about the filter layer thereby reducing energy consumption . Combining new approaches in air flow pattern, in filter design, in new cleaning method to dislodge the dust cake from filters and in sophisticated filter material, it will increase the performance of the filtration system.

Reinsch H.,Institute For Luft Und Kaltetechnik Gemeinnutzige Gesellschaft Mbh | Spadiut O.,Vienna University of Technology | Heidingsfelder J.,Institute For Luft Und Kaltetechnik Gemeinnutzige Gesellschaft Mbh | Herwig C.,Vienna University of Technology
Enzyme and Microbial Technology | Year: 2015

Numerous biopharmaceuticals are produced in recombinant microorganisms in the controlled environment of a bioreactor, a process known as Upstream Process. To minimize product loss due to physico-chemical and enzymatic degradation, the Upstream Process should be directly followed by product purification, known as Downstream Process. However, the Downstream Process can be technologically complex and time-consuming which is why Upstream and Downstream Process usually have to be decoupled temporally and spatially. Consequently, the product obtained after the Upstream Process, known as intermediate bulk, has to be stored. In those circumstances, a freezing procedure is often performed to prevent product loss. However, the freezing process itself is inseparably linked to physico-chemical changes of the intermediate bulk which may in turn damage the product.The present study analysed the behaviour of a Tris-buffered intermediate bulk containing a biopharmaceutically relevant protein during a bottle freezing process. Major damaging mechanisms, like the spatiotemporal redistribution of ion concentrations and pH, and their influence on product stability were investigated. Summarizing, we show the complex events which happen in an intermediate bulk during freezing and explain the different causes for product loss. © 2015 The Authors.

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