Keding, Marcus

Official Name
Keding, Marcus
Main Affiliation
Akademische Titel
DI
Email
marcus.keding@forschung-burgenland.at
Scopus Author ID
36468736300
Status
staff

Settings

Now showing 1 - 9 of 9
  • Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Patent,
      224  287
  • Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Innovative Hydrogen Storage Solutions for Aerospace Applications
    (Jülich GmbH, 2010)
    ;
    Reissner, Alexander 
    ;
    Schmid, G. 
    ;
    Tajmar, M. 
      163  447
  • Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Improved µ-scale Turbine Expander for Energy Recovery
    (ASME, 2010-06-14)
    ;
    Dudzinski, Piotr 
    ;
    Reissner, Alexander 
    ;
    Hummel, Stefan 
    ;
    Tajmar, Martin 
    Scopus© Citations 4  166  350
  • Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Neutron transmission measurements on hydrogen filled microspheres
    (Elsevier, 2013-10-26)
    Dyrnjaja, Eva 
    ;
    Hummel, Stefan 
    ;
    ;
    Smolle, Marie-Theres 
    ;
    Gerger, Joachim 
    Hollow microspheres are promising candidates for future hydrogen storage technologies. Although the physical process for hydrogen diffusion through glass is well understood, measurements of static quantities (e.q. hydrogen pressure inside the spheres) as well as dynamic properties (e.g. diffusion rate of hydrogen through glass) are still difficult to handle due to the small size of the spheres (d ! 15 lm). For diffusion rate measurements, the long-term stability of the experiment is also mandatory due to the relatively slow diffusion rate. In this work, we present an accurate and long-term stable measurement technique for static and dynamic properties, using neutron radiography. Furthermore, possible applications for hydrogen filled microspheres within the scope of radiation issues are discussed.
      1Scopus© Citations 2  94
  • Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Radiation Shielding Using Micro Cavities Filled with Highly Pressurised Gas
    (2012-11-29)
    Usually, hydrogen is stored under high pressure, in chemical compounds or in its liquid state requiring very low temperatures. Gaseous hydrogen can be stored in hollow glass microspheres (5 μm to 200μm diameters) under high pressure (350 bar to 700 bar). The sphere-wall is impermeable for hydrogen at ambient temperature; the heating of the spheres increases the diffusion of hydrogen through the wall. The Aerospace Engineering group of the FOTEC GmbH developed an innovative process for the European Space Agency that combines the storage concepts of hollow glass microspheres with chemical hydrogen storage. The combination of these two principles provides the advantages of both but cancels their respective drawbacks. Our analysis shows that such a system can reach hydrogen storage capacities of up to 10wt% in theory. This value depends on the sphere dimensions, the weight of the spheres, the hydrogen pressure, and the nature of the utilised hydride. The expertise gained in the course of the extensive research on gas storage in hollow microspheres lead to new applications for such a system. One of these applications is the use of microspheres filled with highly pressurized gas as radiation shielding material. Since hydrogen is very effective in absorbing the energy of highly energetic particles with minimal generation of secondary particles, it is particularly suitable for radiation shielding. Effective radiation shielding materials therefore often incorporate high concentrations of hydrogen. By using glass microspheres, it becomes possible to collect large amounts of hydrogen atoms with a relatively high gravimetric as well as volumetric density. It is also possible to store other light gases in the microspheres like deuterium or helium, in order to customize the absorption properties of the material. Preliminary calculations show that this technique can be used as radiation shielding with significant mass savings in respect to conventional materials. In comparison to aluminium for example, the hydrogen filled microspheres can shield high-energy protons and ions with 30% to 40 % increased efficiency. Also bremsstrahlung, secondary neutrons and gamma rays can be significantly reduced. Due to the fact that the material can be easily adapted to any given form, the possible terrestrial applications include: radiation shielding of aircrafts, shielding of computer and electronics, radiation shielding in research facilities as well as on medical sites, but also protective clothing for PCRs (Competent Person in Radioprotection). Considering the possibility to produce large amounts of such a material with relatively low cost, a broad industrial interest for such a light-weight and ultra-dense radiation shielding material can be expected. Also, the considered material is easy to handle with respect to safety and flexibility. Space technology could be used to protect the environment and the population against radiation. To make this technology available for terrestrial applications, the first step is the detailed assessment of the physical processes of gas-filled microspheres in a radioactive environment. It is then possible to investigate the best combination of gas species, microsphere properties, coating layer and support structure or binding material for different applications. The second step is the production of a prototype layer material based on filled microspheres and the testing of the radiation shielding properties of the new material. The Aerospace Engineering group is specialised in the development of micro propulsion and gas storage systems for space application. It has a long record of successful projects performed on behalf of the European Space Agency. As research and service provider of the University of Applied Sciences Wiener Neustadt, it is the ideal hub for educational, industrial and scientific projects. A test facility to test the catalyst efficiency and the thermal properties of the coated microspheres as well as filling the microspheres with different gases is available.
      1  125
  • Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Novel Hydrogen Storage Solutions for Space and Aerospace Applications
    (2011-05-15)
    ;
    Reissner, A. 
    ;
    Bichler, D. 
    ;
    Tajmar, M. 
    Novel hydrogen storage solutions are increasingly important for a number of future aerospace and space applications. The Aerospace Engineering Group of the fotec Forschungs- und Technologietransfer GmbH is presently developing an innovative hydrogen storage system based on high pressure hydrogen storage in microspheres. The hollow glass microspheres are loaded with up to 700 bar of hydrogen gas with a thermal process. The gas was released with a special heating wire. Such a system could be used as safety gas generator on satellites and airplanes. An additional space application for hydrogen filled microspheres seemed to be the use as additive in cryogenic liquid storage systems to enlarge the longtime durability. Further projects deals with new energy storage solutions to replace secondary batteries on satellites. We decided to approach this topic by directly coupling a fuel cell with a metal hydride based on Ti-doped sodium alanate. The power dissipation of the fuel cell can be used for desorption of hydrogen where heat is required, instead of being rejected by a heavy thermal control system. This advantage would be very interesting in order to obtain higher weight efficiencies which are especially important for space and submarine applications.
      243  394
  • Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Optimization of a container design for depositing uniform metal coatings on glass microspheres by magnetron sputtering
    (Elsevier, 2010-08-24)
    Schmid, G. 
    ;
    Eisenmenger-Sittner, C. 
    ;
    Hell, J. 
    ;
    Horkel, M. 
    ;
    Coating granular substrates by PVD methods like magnetron sputtering is a very challenging process. Although many of such substrates may also be coated by other means like the sol gel method, there are coating materials (e. g. refractory metals) for which PVD processes are the method of choice. One of these substrates is hollow glass microspheres with 2–80 μm diameter which can be used for hydrogen storage if a proper catalytic film is applied. To achieve a uniform film by magnetron sputtering on all the spheres a special apparatus was used which basically consists of rotating vessels positioned beneath the target. The arising problems of agglutination of the powdery substrate were solved by designing a special coating vessel, where the spheres are contained during deposition. For testing the system first copper was used as a target material, which was then replaced by platinum since the glass microspheres are used for a catalytic application. The film thickness on the spheres was determined by optical absorption and matches well with the thickness calculated for the special vessel geometry. Additionally it is shown that the glass microspheres can be coated with a uniform layer by magnetron sputtering whereas coatings produced by a chemical deposition process are not continuous.
      1Scopus© Citations 18  99
  • Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Metal Hydrides as Hydrogen and Heat Storage System for Satellite Applications
    (2013-06-16)
    Reissner, Alexander 
    ;
    ;
    Hummel, Stefan 
    ;
    Scharlemann, Carsten 
    ;
    Tajmar, Martin 
      2  150
  • Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Characterization of the Reversible Hydrogenation Properties of Sodium Alanate under various contaminated Hydrogen Conditions
    (2013-06-17)
    Reissner, Alexander 
    ;
    ;
    Hummel, Stefan 
    ;
    Scharlemann, Carsten 
    ;
    Tajmar, Martin 
      1  159