@article{BaroudWuBohneretal.2003, author = {Baroud, G. and Wu, J.Z. and Bohner, M and Sponagel, Stefan and Steffen, T.}, title = {How to determine the permeability for cement infiltration into osteoporotic cancellous bone}, series = {Medical Engineering \& Physics. 25 (2003), H. 4}, journal = {Medical Engineering \& Physics. 25 (2003), H. 4}, issn = {1350-4533}, pages = {283 -- 288}, year = {2003}, abstract = {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.}, subject = {Osteoporose}, language = {en} } @inproceedings{DarvenizaFlisowskiKernetal.2002, author = {Darveniza, M. and Flisowski, Z. and Kern, Alexander and Landers, E.-U. and LoPiparo, G. and Mazzetti, C. and Rousseau, A. and Sherlock, J.}, title = {Application problems of the probabilistic approach to the assessment of risk for structures and services}, year = {2002}, abstract = {The paper deals with the development of the probabilistic approach to the assessment of risk due to lightning. Sources of damage, types of damage and types of loss are defined and, accordingly, the procedure for risk analysis and the way of assessment of different risk components is proposed. The way to evaluate the influence of different protection measures (lightning protection system; shielding of structure, cables and equipment; routing of internal wiring; surge protective device) in reducing such probabilities is considered. The paper has been prepared within the framework of the activity of IEC TC81-WG9/CLC TC81-WG4 directed to prepare the draft IEC 62305-2 Risk Management, in cooperation with the Secretary of IEC/CLC TC81.}, language = {en} } @inproceedings{DielmannPeters2002, author = {Dielmann, Klaus-Peter and Peters, Bernhard}, title = {Micro Turbine Using Different Gases and Liquid Fuels}, year = {2002}, abstract = {Micro turbine using different gases and liquid fuels}, subject = {Gasturbine}, language = {en} } @inproceedings{DielmannSchieke2000, author = {Dielmann, Klaus-Peter and Schieke, Wolf}, title = {Mikrogasturbinen - Aufbau und Anwendungen}, year = {2000}, abstract = {Mikrogasturbinen: Funktion, Aufbau, Hersteller, Bauformen, Rekuperatorparameter, Besonderheit der Konstruktion, Regelung, Regelbarkeit, Vergleich mit anderen Systemen, Wirkungs- und Nutzungsgrade, Schadstoffemissionen, Nutzung in Kraft-W{\"a}rme-Kopplung, Kraft-W{\"a}rme-K{\"a}lte-Kopplung}, subject = {Gasturbine}, language = {de} } @inproceedings{DielmannVelden2003, author = {Dielmann, Klaus-Peter and Velden, Alwin van der}, title = {Virtuelle Kraftwerke - Stand der Technik}, year = {2003}, abstract = {Ausgangslage, Funktionsprinzip des virtuellen Kraftwerkes, Energiemanagementsysteme (EMS), Einsatzgebiete, Anlagesysteme eines VKW's, Einsatzbereich der verschiedenen dezentralen Energieanlagen, Vorteile des virtuellen Kraftwerkes, Auswirkungen auf das elektrische Netz, Wirtschaftliche Aspekte, Beispielprojekte}, language = {de} } @misc{Gebhardt2005, author = {Gebhardt, Andreas}, title = {{\"U}bungsklausur zum Fach Werkstoffkunde 3}, year = {2005}, abstract = {{\"U}bungsklausur}, language = {de} } @misc{Gebhardt2005, author = {Gebhardt, Andreas}, title = {Fertigungsverfahren I : Urformen ; Skript zur Vorlesung}, year = {2005}, abstract = {Urformen aus dem fl{\"u}ssigen oder teigigen Zustand Im Mittelpunkt stehen alle Gießverfahren. Großtechnische Bedeutung haben neben den Metallgießverfahren vor allem auch Verfahren zum Urformen von Kunststoffen und in steigendem Maße auch solche zur Herstellung von Keramiken und Kompositwerkstoffen}, language = {de} } @misc{Gebhardt2005, author = {Gebhardt, Andreas}, title = {Fertigungsverfahren I : Umformen ; Skript zur Vorlesung}, year = {2005}, abstract = {Grundlagen, Druck-Umformen (Walzen, Schmieden, Gesenkschmieden), Zugdruckumformen (Durchziehen, Tiefziehen), Zugumformen, Biegeumformen}, language = {de} } @misc{Gebhardt2005, author = {Gebhardt, Andreas}, title = {{\"U}bungsklausur zum Fach Fertigungsverfahren 1}, year = {2005}, abstract = {{\"U}bungsklausur}, language = {de} } @misc{Gebhardt2005, author = {Gebhardt, Andreas}, title = {Regelungstechnik : Skript zur Vorlesung}, year = {2005}, abstract = {Prinzip und Geschichte der Regelungstechnik; technische Steuerungen und Regelungen; Definition und Stellung innerhalb der Automatisierungstechnik. Elementare {\"U}bertragungsglieder, Streckentypen, typische Regler (unstetige Regler, stetige Regler), Reglerentwurf (einfache Verfahren, einschließlich Faustformelverfahren). Stabilit{\"a}tsanalyse von Regelkreisen (einfache Verfahren, ohne Herleitung der Beweise)}, language = {de} }