TY  - JOUR
A1  - Sponagel, Stefan
A1  - Groling, G.
T1  - Eine Bemerkung zum Beweis des π Theorems. G. Groling, S. Sponagel
JF  - Zeitschrift für angewandte Mathematik und Mechanik: ZAMM. 63 (1983)
Y1  - 1983
SN  - 0044-2267
N1  - weitere ISSN: 0946-8463
SP  - T258
EP  - T259
ER  - 
TY  - JOUR
A1  - Sponagel, Stefan
A1  - Müller, H.
T1  - Exakte instationäre Lösungen der Navier-Stokes-Gleichung. H. Müller, S. Sponagel
JF  - Zeitschrift für angewandte Mathematik und Mechanik: ZAMM. 63 (1983)
Y1  - 1983
SN  - 0044-2267
N1  - weitere ISSN: 0946-8463
SP  - T273
EP  - T275
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Sponagel, Stefan
A1  - Nguyen, Nhu Huynh
T1  - Experiment and material model for soft tissue materials
JF  - Constitutive  models for rubber VI : proceedings of the sixth European Conference on Constitutive Models for Rubber, Dresden, Germany, 7 - 10 September 2009 / eds. Gert Heinrich ...
Y1  - 2010
SN  - 978-0-415-56327-7
SP  - 465
EP  - 470
PB  - CRC Press
CY  - Boca Raton [u.a.]
ER  - 
TY  - JOUR
A1  - Sponagel, Stefan
A1  - Baroud, G.
A1  - Falk, R.
A1  - Crookshank, M.
T1  - 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
JF  - Journal of Biomechanics. 37 (2004), H. 2
Y1  - 2004
SN  - 0021-9290
SP  - 189
EP  - 196
ER  - 
TY  - BOOK
A1  - Sponagel, Stefan
T1  - Gummi-Metall-Bauteile
Y1  - 1987
N1  - Universität Kaiserslautern, Dissertation
CY  - Kaiserslautern
ER  - 
TY  - JOUR
A1  - Sponagel, Stefan
A1  - Spaltofski, R.
A1  - Steinhilper, W.
T1  - Hochmolekulare Additive für die Gleitlagerschmierung. Spaltofski, R.; Sponagel, S.; Steinhilper, W.
JF  - Tribologie und Schmierungstechnik. 35 (1988), H. 5
Y1  - 1988
SN  - 0036-6218
SP  - 236
EP  - 241
ER  - 
TY  - JOUR
A1  - Sponagel, Stefan
A1  - Spaltofski, R.
T1  - Hochmolekulare Zusätze verbessern die Leichtlaufeigenschaft und die Tragfähigkeit von Schmierfilmen / Sponagel, S.  ; Spaltofski, R.
JF  - Mineralöltechnik. 32 (1987), H. 3
Y1  - 1987
SN  - 0341-1893
SP  - 28 S.
ER  - 
TY  - JOUR
A1  - Baroud, G.
A1  - Wu, J.Z.
A1  - Bohner, M
A1  - Sponagel, Stefan
A1  - Steffen, T.
T1  - How to determine the permeability for cement infiltration into osteoporotic cancellous bone
JF  - Medical Engineering & Physics. 25 (2003), H. 4
N2  - Cement augmentation is an emerging surgical procedure in which bone cement is used to infiltrate and reinforce osteoporotic vertebrae. Although this infiltration procedure has been widely applied, it is performed empirically and little is known about the flow characteristics of cement during the injection process. We present a theoretical and experimental approach to investigate the intertrabecular bone permeability during the infiltration procedure. The cement permeability was considered to be dependent on time, bone porosity, and cement viscosity in our analysis. In order to determine the time-dependent permeability, ten cancellous bone cores were harvested from osteoporotic vertebrae, infiltrated with acrylic cement at a constant flow rate, and the pressure drop across the cores during the infiltration was measured. The viscosity dependence of the permeability was determined based on published experimental data. The theoretical model for the permeability as a function of bone porosity and time was then fit to the testing data. Our findings suggest that the intertrabecular bone permeability depends strongly on time. For instance, the initial permeability (60.89 mm4/N.s) reduced to approximately 63% of its original value within 18 seconds. This study is the first to analyze cement flow through osteoporotic bone. The theoretical and experimental models provided in this paper are generic. Thus, they can be used to systematically study and optimize the infiltration process for clinical practice.
KW  - Osteoporose
KW  - Permeabilität
KW  - Viskose Strömung
KW  - Viskosität
KW  - Vertebroplastie
KW  - Cement infiltration
KW  - Vertebroplasty
KW  - Osteoporosis
KW  - Permeability
KW  - Experiment
KW  - Analysis
KW  - Viscous flow
Y1  - 2003
SN  - 1350-4533
SP  - 283
EP  - 288
ER  - 
TY  - JOUR
A1  - Sponagel, Stefan
A1  - Unger, J.
A1  - Spies, K. H.
T1  - Härtebegriff im Zusammenhang mit Vernetzung, Bruchdehnung und Dauerfestigkeit eines Elastomers
JF  - Kautschuk Gummi Kunststoffe. 56 (2003), H. 11
Y1  - 2003
SN  - 0948-3276
SP  - 608
EP  - 613
ER  - 
TY  - JOUR
A1  - Sponagel, Stefan
A1  - Akbay, U.
A1  - Becker, E.
T1  - Instability of plane Couette flow of viscoelastic liquids
JF  - Journal of non-Newtonian fluid mechanics. 18 (1985), H. 2
Y1  - 1985
SN  - 0377-0257
SP  - 123
EP  - 141
ER  -