@article{Staat2021,
  author    = {Staat, Manfred},
  title     = {An extension strain type Mohr-Coulomb criterion},
  series = {Rock mechanics and rock engineering},
  volume    = {54},
  journal   = {Rock mechanics and rock engineering},
  number    = {12},
  publisher = {Springer Nature},
  address   = {Cham},
  issn      = {1434-453X},
  doi       = {10.1007/s00603-021-02608-7},
  pages     = {6207 -- 6233},
  year      = {2021},
  abstract  = {Extension fractures are typical for the deformation under low or no confining pressure. They can be explained by a phenomenological extension strain failure criterion. In the past, a simple empirical criterion for fracture initiation in brittle rock has been developed. In this article, it is shown that the simple extension strain criterion makes unrealistic strength predictions in biaxial compression and tension. To overcome this major limitation, a new extension strain criterion is proposed by adding a weighted principal shear component to the simple criterion. The shear weight is chosen, such that the enriched extension strain criterion represents the same failure surface as the Mohr-Coulomb (MC) criterion. Thus, the MC criterion has been derived as an extension strain criterion predicting extension failure modes, which are unexpected in the classical understanding of the failure of cohesive-frictional materials. In progressive damage of rock, the most likely fracture direction is orthogonal to the maximum extension strain leading to dilatancy. The enriched extension strain criterion is proposed as a threshold surface for crack initiation CI and crack damage CD and as a failure surface at peak stress CP. Different from compressive loading, tensile loading requires only a limited number of critical cracks to cause failure. Therefore, for tensile stresses, the failure criteria must be modified somehow, possibly by a cut-off corresponding to the CI stress. Examples show that the enriched extension strain criterion predicts much lower volumes of damaged rock mass compared to the simple extension strain criterion.},
  language  = {en}
}
@article{SrnanekGeurtsLentzeetal.2004,
  author    = {Srnanek, R. and Geurts, J. and Lentze, M. and Irmer, G. and Donoval, D. and Brdecka, P. and Kordos, P. and F{\"o}rster, Arnold and Sciana, B. and Radziewicz, D. and Tlaczala, M.},
  title     = {Study of d-doped GaAs layers by micro-Raman spectroscopy on bevelled samples},
  series = {Applied surface science . 230 (2004), H. 1 -4},
  journal   = {Applied surface science . 230 (2004), H. 1 -4},
  isbn      = {0169-4332},
  pages     = {379 -- 385},
  year      = {2004},
  language  = {en}
}
@inproceedings{SrivastavaSinghDhandetal.2006,
  author    = {Srivastava, Alok and Singh, Virendra and Dhand, Chetna and Kaur, Manindar and Singh, Tejvir and Witte, Katrin and Scherer, Ulrich W.},
  title     = {Study of swift heavy ion modified conduction polymer composites for application as gas sensor},
  url       = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1345},
  year      = {2006},
  abstract  = {A polyaniline-based conducting composite was prepared by oxidative polymerisation of aniline in a polyvinylchloride (PVC) matrix. The coherent free standing thin films of the composite were prepared by a solution casting method. The polyvinyl chloride-polyaniline composites exposed to 120 MeV ions of silicon with total ion fluence ranging from 1011 to 1013 ions/cm2, were observed to be more sensitive towards ammonia gas than the unirradiated composite. The response time of the irradiated composites was observed to be comparably shorter. We report for the first time the application of swift heavy ion modified insulating polymer conducting polymer (IPCP) composites for sensing of ammonia gas.},
  subject      = {Biosensor},
  language  = {en}
}
@incollection{SrivastavaKnolleHoyleretal.2015,
  author    = {Srivastava, Alok and Knolle, Friedhart and Hoyler, Friedrich and Scherer, Ulrich W. and Schnug, Ewald},
  title     = {Uranium Toxicity in the State of Punjab in North-Western India},
  series = {Management of Natural Resources in a Changing Environment},
  booktitle = {Management of Natural Resources in a Changing Environment},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-319-12559-6},
  doi       = {10.1007/978-3-319-12559-6_21},
  pages     = {271 -- 275},
  year      = {2015},
  abstract  = {Lately there has been an increasing concern about uranium toxicity in some districts of Punjab State located in the North Western part of India after the publication of a report (Blaurock-Busch et al. 2010) which showed that the concentration of uranium in hair and urine of children suffering from physical deformities, neurological and mental disorder from Malwa region (Fig. 1) of Punjab State was manifold higher than the reference ranges. A train which connects the affected region with the nearby city of Bikaner which has a Cancer Hospital has been nicknamed as Cancer Express due to the frenzy generated on account of uranium related toxicity.},
  language  = {en}
}
@article{SrivastavaSinghAggarwaletal.2010,
  author    = {Srivastava, A. and Singh, V. and Aggarwal, P. and Schneeweiss, F. and Scherer, Ulrich W. and Friedrich, W.},
  title     = {Optical studies of insulating polymers for radiation dose monitoring},
  series = {Indian Journal of Pure \& Applied Physics},
  volume    = {48},
  journal   = {Indian Journal of Pure \& Applied Physics},
  number    = {11},
  isbn      = {0019-5596},
  pages     = {782 -- 786},
  year      = {2010},
  language  = {en}
}
@article{SrivastavaLahiriMaitietal.2014,
  author    = {Srivastava, A. and Lahiri, S. and Maiti, M. and Knolle, F. and Hoyler, Friedrich and Scherer, Ulrich W. and Schnug, E. W.},
  title     = {Study of naturally occurring radioactive material (NORM) in top soil of Punjab State from the North Western part of India},
  series = {Journal of Radioanalytical and Nuclear Chemistry},
  volume    = {2014},
  journal   = {Journal of Radioanalytical and Nuclear Chemistry},
  number    = {302},
  publisher = {Springer Nature},
  address   = {Basel},
  issn      = {1588-2780 (E-Journal); 0022-4081 (Print); 0134-0719 (Print); 0236-5731 (Print); 1417-2097 (Print)},
  doi       = {0.1007/s10967-014-3450-1},
  pages     = {1049 -- 1052},
  year      = {2014},
  language  = {en}
}
@article{SrivastavaChaharSharmaetal.2017,
  author    = {Srivastava, A. and Chahar, V. and Sharma, V. and Sun, Y. and Bol, R. and Knolle, F. and Schnug, E. and Hoyler, Friedrich and Naskar, N. and Lahiri, S. and Patnaik, R.},
  title     = {Study of uranium toxicity using low-background gamma-ray spectrometry},
  series = {Journal of Radioanalytical and Nuclear Chemistry},
  journal   = {Journal of Radioanalytical and Nuclear Chemistry},
  number    = {Online first},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {1588-2780},
  doi       = {10.1007/s10967-017-5466-9},
  pages     = {1 -- 7},
  year      = {2017},
  language  = {en}
}
@inproceedings{SpaeteHafnerSchwarzer2000,
  author    = {Sp{\"a}te, Frank and Hafner, B. and Schwarzer, Klemens},
  title     = {A system for solar process heat for decentralized applications in developing countries},
  series = {ISES 1999 Solar World Congress, Jerusalem, Israel, July 4-9, 1999 : conference proceedings / ed. Gershon Grossman. Vol. 3},
  booktitle = {ISES 1999 Solar World Congress, Jerusalem, Israel, July 4-9, 1999 : conference proceedings / ed. Gershon Grossman. Vol. 3},
  publisher = {Elsevier},
  address   = {Oxford},
  isbn      = {0-080-043895-4},
  pages     = {236 -- 291},
  year      = {2000},
  language  = {en}
}
@article{SpaeteFaberSchwarzeretal.2004,
  author    = {Sp{\"a}te, Frank and Faber, Christian and Schwarzer, Klemens and Hartz, Thomas},
  title     = {Comparison of solar hot water systems in solar settlements - decentralized or centralized systems?},
  series = {Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol. 1},
  journal   = {Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol. 1},
  publisher = {PSE},
  address   = {Freiburg [Breisgau]},
  isbn      = {3-9809656-1-9},
  pages     = {1-666-1-671},
  year      = {2004},
  language  = {en}
}
@inproceedings{SpurmannOhndorfDachwaldetal.2009,
  author    = {Spurmann, J{\"o}rn and Ohndorf, Andreas and Dachwald, Bernd and Seboldt, Wolfgang and L{\"o}b, Horst and Schartner, Karl-Heinz},
  title     = {Interplanetary trajectory optimization for a sep mission to Saturn},
  series = {60th International Astronautical Congress 2009},
  booktitle = {60th International Astronautical Congress 2009},
  isbn      = {9781615679089},
  pages     = {5234 -- 5248},
  year      = {2009},
  abstract  = {The recently proposed NASA and ESA missions to Saturn and Jupiter pose difficult tasks to mission designers because chemical propulsion scenarios are not capable of transferring heavy spacecraft into the outer solar system without the use of gravity assists. Thus our developed mission scenario based on the joint NASA/ESA Titan Saturn System Mission baselines solar electric propulsion to improve mission flexibility and transfer time. For the calculation of near-globally optimal low-thrust trajectories, we have used a method called Evolutionary Neurocontrol, which is implemented in the low-thrust trajectory optimization software InTrance. The studied solar electric propulsion scenario covers trajectory optimization of the interplanetary transfer including variations of the spacecraft's thrust level, the thrust unit's specific impulse and the solar power generator power level. Additionally developed software extensions enabled trajectory optimization with launcher-provided hyperbolic excess energy, a complex solar power generator model and a variable specific impulse ion engine model. For the investigated mission scenario, Evolutionary Neurocontrol yields good optimization results, which also hold valid for the more elaborate spacecraft models. Compared to Cassini/Huygens, the best found solutions have faster transfer times and a higher mission flexibility in general.},
  language  = {en}
}
@misc{SponagelWachowitz1992,
  author    = {Sponagel, Stefan and Wachowitz, Waldemar},
  title     = {Shaft seal : United States Patent 5,143,385 ; date of patent: Sep. 1, 1992 / assignee: Firma Carl Freudenberg},
  publisher = {[United States Patent and Trademark Office]},
  address   = {[Alexandria, VA]},
  pages     = {5 S. : Ill.},
  year      = {1992},
  language  = {en}
}
@article{SponagelKilthauSpies1987,
  author    = {Sponagel, Stefan and Kilthau, G. and Spies, K. H.},
  title     = {Sealing mechanism of lip seals},
  series = {Eleventh 11th International Conference on Fluid Sealing : proceedings of the 11th Internat. Conference on Fluid Sealing, held at Cannes, France 8 - 10 April, 1987 / organised and sponsored by BHRA, the Fluid Engineering Centre. Ed. B. S. Nau},
  journal   = {Eleventh 11th International Conference on Fluid Sealing : proceedings of the 11th Internat. Conference on Fluid Sealing, held at Cannes, France 8 - 10 April, 1987 / organised and sponsored by BHRA, the Fluid Engineering Centre. Ed. B. S. Nau},
  publisher = {Elsevier},
  address   = {London},
  isbn      = {3-540-51383-3},
  pages     = {748 -- 772},
  year      = {1987},
  language  = {en}
}
@misc{SponagelGrafGross1989,
  author    = {Sponagel, Stefan and Graf, G{\"u}nter and Groß, Heinz},
  title     = {Method for manufacturing a sealing ring : United States Patent 4,861,536 ; date of patent: Aug. 12, 1989 / assignee: Firma Carl Freudenberg. Inventors: Gunter Graf ; Heinz Gross ; Stefan Sponagel},
  publisher = {[United States Patent and Trademark Office]},
  address   = {[Alexandria, VA]},
  pages     = {5 S. : Ill.},
  year      = {1989},
  language  = {en}
}
@misc{SponagelGrafGross1989,
  author    = {Sponagel, Stefan and Graf, G{\"u}nter and Groß, Heinz},
  title     = {Method for the manufacture of a sealing ring with a sealing lip having hydrodynamically acting return elements : United States Patent 4,850,097 ; date of patent: Jul. 25, 1989 / assignee: Firma Carl Freudenberg. Inventors: Gunter Graf ; Heinz Gross ; Stefan Sponagel},
  publisher = {[United States Patent and Trademark Office]},
  address   = {[Alexandria, VA]},
  pages     = {4 S. : Ill.},
  year      = {1989},
  language  = {en}
}
@article{SponagelBaroudSteffenetal.2002,
  author    = {Sponagel, Stefan and Baroud, G. and Steffen, T. and Wu, J.},
  title     = {Parameter identification for cement infiltration of osteoporotic bone},
  series = {Poromechanics II : Proceedings of the Second Biot Conference on Poromechanics Grenoble, France 26 - 28 August 2002 / ed. by J.-L. Auriault ...},
  journal   = {Poromechanics II : Proceedings of the Second Biot Conference on Poromechanics Grenoble, France 26 - 28 August 2002 / ed. by J.-L. Auriault ...},
  publisher = {Balkema},
  address   = {Lisse [u.a.]},
  isbn      = {90-5809-394-8},
  pages     = {55 -- 58},
  year      = {2002},
  language  = {en}
}
@article{SponagelBaroudFalketal.2004,
  author    = {Sponagel, Stefan and Baroud, G. and Falk, R. and Crookshank, M.},
  title     = {Experimental and theoretical investigation of directional permeability of human vertebral cancellous bone for cement infiltration. G. Baroud, R. Falk, M. Crookshank, S. Sponagel, T. Steffen},
  series = {Journal of Biomechanics. 37 (2004), H. 2},
  journal   = {Journal of Biomechanics. 37 (2004), H. 2},
  isbn      = {0021-9290},
  pages     = {189 -- 196},
  year      = {2004},
  language  = {en}
}
@article{SponagelBaroudFalketal.2004,
  author    = {Sponagel, Stefan and Baroud, G. and Falk, R. and Crookshank, M.},
  title     = {Corrigendum to "Experimental and theoretical investigation of directional permeability of human vertebral cancellous bone for cement infiltration". Baroud, G.; Falk, R.; Crookshank, M.; Sponagel, S.; Steffen, T.},
  series = {Journal of Biomechanics. 37 (2004), H. 2},
  journal   = {Journal of Biomechanics. 37 (2004), H. 2},
  isbn      = {0021-9290},
  pages     = {1802},
  year      = {2004},
  language  = {en}
}
@article{SponagelAkbayBeckeretal.1980,
  author    = {Sponagel, Stefan and Akbay, U. and Becker, E. and Krozer, S.},
  title     = {Instability of slow viscometric flow},
  series = {Mechanics Research Communications. 7 (1980), H. 4},
  journal   = {Mechanics Research Communications. 7 (1980), H. 4},
  isbn      = {0093-6413},
  pages     = {199 -- 204},
  year      = {1980},
  language  = {en}
}
@article{SponagelAkbayBecker1985,
  author    = {Sponagel, Stefan and Akbay, U. and Becker, E.},
  title     = {Instability of plane Couette flow of viscoelastic liquids},
  series = {Journal of non-Newtonian fluid mechanics. 18 (1985), H. 2},
  journal   = {Journal of non-Newtonian fluid mechanics. 18 (1985), H. 2},
  isbn      = {0377-0257},
  pages     = {123 -- 141},
  year      = {1985},
  language  = {en}
}
@article{SponagelAdbayBeckeretal.1980,
  author    = {Sponagel, Stefan and Adbay, U. and Becker, E. and Krozer, S.},
  title     = {A possible cause of viscoelastic turbulence},
  series = {Rheology : proceedings of the 8th International Congress of Rheology, held in Naples, Italy, September 1 - 5, 1980 / Hrsg. von Giovanni Astarita, Vol. 2},
  journal   = {Rheology : proceedings of the 8th International Congress of Rheology, held in Naples, Italy, September 1 - 5, 1980 / Hrsg. von Giovanni Astarita, Vol. 2},
  publisher = {Plenum Pr.},
  address   = {New York},
  isbn      = {0-306-40465-6},
  pages     = {79 -- 84},
  year      = {1980},
  language  = {en}
}