@article{LinnowNiermannBonatzetal.,
  author    = {Linnow, Kirsten and Niermann, Michael and Bonatz, Dennis and Posern, Konrad and Steiger, Michael},
  title     = {Experimental Studies of the Mechanism and Kinetics of Hydration Reactions},
  series = {Energy Procedia},
  journal   = {Energy Procedia},
  doi       = {10.1016/j.egypro.2014.02.046},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170425-31484},
  pages     = {394 -- 404},
  abstract  = {The mechanism and the kinetics of hydration reactions are important for the application of a salt hydrate as a thermochemical heat storage material. MgSO4·H2O and Na2SO4 were chosen in this study because they are both promising candidates for such an application. Considering that the hydration of these salts yields MgSO4·7H2O and Na2SO4·10H2O as the reaction products, the maximum overall heat effect can be calculated from the heat of condensation of water vapor (44 kJ mol-1) and the heats of hydration of 75 kJ·mol-1 (for MgSO4·H2O) and 81 kJ mol-1 (for Na2SO4). Based on the densities of the two hydrated phases, this results in the very high theoretical energy densities of 2.3 GJ·m-3 and 2.4 GJ·m-3, respectively, for MgSO4·7H2O and Na2SO4·10H2O. Not only the energy density is important for the dimensioning of a storage system, but also the kinetics of hydration reactions play a major role for the application as storage material. In the present study, hydration reactions under varying climatic conditions were investigated by using water vapor sorption measurements and in-situ Raman microscopy. Using the phase diagrams, it can be clearly shown that the mechanism and the kinetics depend on the climatic conditions. Below the deliquescence humidity of the lower hydrated phase the hydration proceeds as solid state reaction, whilst above the deliquescence humidity a through solution mechanism takes place.},
  subject      = {W{\"a}rmespeicherung},
  language  = {en}
}
@article{MotraHildebrandDimmigOsburg,
  author    = {Motra, Hem Bahadur and Hildebrand, J{\"o}rg and Dimmig-Osburg, Andrea},
  title     = {Assessment of strain measurement techniques to characterise mechanical properties of structural steel},
  series = {Engineering Science and Technology, an International Journal},
  journal   = {Engineering Science and Technology, an International Journal},
  doi       = {10.1016/j.jestch.2014.07.006},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170425-31540},
  pages     = {260 -- 269},
  abstract  = {Strain measurement is important in mechanical testing. A wide variety of techniques exists for measuring strain in the tensile test; namely the strain gauge, extensometer, stress and strain determined by machine crosshead motion, Geometric Moire technique, optical strain measurement techniques and others. Each technique has its own advantages and disadvantages. The purpose of this study is to quantitatively compare the strain measurement techniques. To carry out the tensile test experiments for S 235, sixty samples were cut from the web of the I-profile in longitudinal and transverse directions in four different dimensions. The geometry of samples are analysed by 3D scanner and vernier caliper. In addition, the strain values were determined by using strain gauge, extensometer and machine crosshead motion. Three techniques of strain measurement are compared in quantitative manner based on the calculation of mechanical properties (modulus of elasticity, yield strength, tensile strength, percentage elongation at maximum force) of structural steel. A statistical information was used for evaluating the results. It is seen that the extensometer and strain gauge provided reliable data, however the extensometer offers several advantages over the strain gauge and crosshead motion for testing structural steel in tension. Furthermore, estimation of measurement uncertainty is presented for the basic material parameters extracted through strain measurement.},
  subject      = {Baustahl},
  language  = {en}
}
@phdthesis{Buchwald,
  author    = {Buchwald, Anja},
  title     = {Der Einfluss des Kalziums auf die Kondensation von (Alumo-)Silikaten in alkali-aktivierten Bindern},
  doi       = {10.25643/bauhaus-universitaet.2104},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20140124-21046},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  pages     = {35},
  abstract  = {Es werden geopolymere und alkali-aktivierte Bindemittel definiert und ihre prinzipiellen technischen und {\"o}kologischen Eigenschaften diskutiert.},
  subject      = {Bindemittel},
  language  = {de}
}