TY - JOUR A1 - Pieper, Martin A1 - Klein, Peter T1 - Application of simple, periodic homogenization techniques to non-linear heat conduction problems in non-periodic, porous media JF - Heat mass transfer N2 - Often, detailed simulations of heat conduction in complicated, porous media have large runtimes. Then homogenization is a powerful tool to speed up the calculations by preserving accurate solutions at the same time. Unfortunately real structures are generally non-periodic, which requires unpractical, complicated homogenization techniques. We demonstrate in this paper, that the application of simple, periodic techniques to realistic media, that are just close to periodic, gives accurate, approximative solutions. In order to obtain effective parameters for the homogenized heat equation, we have to solve a so called “cell problem”. In contrast to periodic structures it is not trivial to determine a suitable unit cell, which represents a non-periodic media. To overcome this problem, we give a rule of thumb on how to choose a good cell. Finally we demonstrate the efficiency of our method for virtually generated foams as well as real foams and compare these results to periodic structures. Y1 - 2012 U6 - http://dx.doi.org/10.1007/s00231-011-0879-4 SN - 0947-7411 VL - 48 IS - 2 SP - 291 EP - 300 PB - Springer CY - Berlin ER - TY - CHAP A1 - Logen, Steffen A1 - Höfken, Hans A1 - Schuba, Marko T1 - Simplifying RAM Forensics : A GUI and Extensions for the Volatility Framework T2 - 2012 Seventh International Conference on Availability, Reliability and Security (ARES), 20-24 August 2012, Prague, Czech Republic N2 - The Volatility Framework is a collection of tools for the analysis of computer RAM. The framework offers a multitude of analysis options and is used by many investigators worldwide. Volatility currently comes with a command line interface only, which might be a hinderer for some investigators to use the tool. In this paper we present a GUI and extensions for the Volatility Framework, which on the one hand simplify the usage of the tool and on the other hand offer additional functionality like storage of results in a database, shortcuts for long Volatility Framework command sequences, and entirely new commands based on correlation of data stored in the database. Y1 - 2012 SN - 978-1-4673-2244-7 U6 - http://dx.doi.org/10.1109/ARES.2012.12 SP - 620 EP - 624 PB - IEEE CY - New York ER - TY - JOUR A1 - Huck, Christina A1 - Poghossian, Arshak A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Combined amperometric/field-effect sensor for the detection of dissolved hydrogen JF - Sensors and actuators B: Chemical N2 - Real-time and reliable monitoring of the biogas process is crucial for a stable and efficient operation of biogas production in order to avoid digester breakdowns. The concentration of dissolved hydrogen (H₂) represents one of the key parameters for biogas process control. In this work, a one-chip integrated combined amperometric/field-effect sensor for monitoring the dissolved H₂ concentration has been developed for biogas applications. The combination of two different transducer principles might allow a more accurate and reliable measurement of dissolved H₂ as an early warning indicator of digester failures. The feasibility of the approach has been demonstrated by simultaneous amperometric/field-effect measurements of dissolved H₂ concentrations in electrolyte solutions. Both, the amperometric and the field-effect transducer show a linear response behaviour in the H₂ concentration range from 0.1 to 3% (v/v) with a slope of 198.4 ± 13.7 nA/% (v/v) and 14.9 ± 0.5 mV/% (v/v), respectively. Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.snb.2012.10.050 SN - 0925-4005 N1 - Part of special issue "Selected Papers from the 14th International Meeting on Chemical Sensors" VL - 187 SP - 168 EP - 173 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Weigand, Christoph T1 - Statistical Tests Based on Reliability and Precision JF - Economic Quality Control : EQC ; international journal for quality and reliability N2 - The construction of a statistical test is investigated which is based only on “reliability” and “precision” as quality criteria. The reliability of a statistical test is quantifiedin a straightforward way by the probability that the decision of the test is correct. However, the quantification of the precision of a statistical test is not at all evident. Thereforethe paper presents and discusses several approaches. Moreover the distinction of “nullhypothesis” and “alternative hypothesis” is not necessary any longer. Y1 - 2012 U6 - http://dx.doi.org/10.1515/eqc-2012-0002 SN - 1869-6147 VL - 27 IS - 1 SP - 43 EP - 64 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Fateri, Miranda A1 - Hötter, Jan-Steffen A1 - Gebhardt, Andreas T1 - Experimental and Theoretical Investigation of Buckling Deformation of Fabricated Objects by Selective Laser Melting JF - Physics Procedia N2 - Although Selective Laser Melting (SLM) process is an innovative manufacturing method, there are challenges such as inferior mechanical properties of fabricated objects. Regarding this, buckling deformation which is caused by thermal stress is one of the undesired mechanical properties which must be alleviated. As buckling deformation is more observable in hard to process materials, silver is selected to be studied theoretically and experimentally for this paper. Different scanning strategies are utilized and a Finite Element Method (FEM) is applied to calculate the temperature gradient in order to determine its effect on the buckling deformation of the objects from experiments. Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.phpro.2012.10.062 SN - 1875-3892 N1 - Part of special issue "Laser Assisted Net shape Engineering 7 (LANE 2012)" VL - 39 SP - 464 EP - 470 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hasan, Istabrak A1 - Keil, Ludger A1 - Staat, Manfred A1 - Wahl, Gerhard A1 - Bourauel, Christoph T1 - Determination of the frictional coefficient of the implant-antler interface : experimental approach JF - Biomedical Engineering / Biomedizinische Technik N2 - The similar bone structure of reindeer antler to human bone permits studying the osseointegration of dental implants in the jawbone. As the friction is one of the major factors that have a significant influence on the initial stability of immediately loaded dental implants, it is essential to define the frictional coefficient of the implant-antler interface. In this study, the kinetic frictional forces at the implant-antler interface were measured experimentally using an optomechanical setup and a stepping motor controller under different axial loads and sliding velocities. The corresponding mean values of the static and kinetic frictional coefficients were within the range of 0.5–0.7 and 0.3–0.5, respectively. An increase in the frictional forces with increasing applied axial loads was registered. The measurements showed an evidence of a decrease in the magnitude of the frictional coefficient with increasing sliding velocity. The results of this study provide a considerable assessment to clarify the suitable frictional coefficient to be used in the finite element contact analysis of antler specimens. Y1 - 2012 SN - 1862-278X VL - 57 IS - 5 SP - 359 EP - 363 PB - De Gruyter CY - Berlin ER - TY - BOOK A1 - Wosnitza, Franz A1 - Hilgers, Hans Gerd T1 - Energieeffizienz und Energiemanagement : ein Überblick heutiger Möglichkeiten und Notwendigkeiten Y1 - 2012 SN - 978-3-8348-1941-3 N1 - eISBN 978-3-8348-8671-2 PB - Springer Spektrum CY - Wiesbaden ER - TY - BOOK A1 - Janser, Frank A1 - Havermann, Marc T1 - Inkompressible Strömungen Y1 - 2012 SN - 978-3-86130-446-3 N1 - Strömungslehre und Aerodynamik PB - Mainz CY - Aachen ER - TY - CHAP A1 - Schopp, Christoph A1 - Nachtrodt, Frederik A1 - Heuermann, Holger A1 - Scherer, Ulrich W. A1 - Mostacci, Domiziano A1 - Finger, Torsten A1 - Tietsch, Wolfgang T1 - A novel 2.45 GHz/200 W Microwave Plasma Jet for High Temperature Applications above 3600 K T2 - Journal of Physics : Conference Series Y1 - 2012 SN - 1742-6596 VL - 406 IS - 012029 ER - TY - CHAP A1 - Nix, Yvonne A1 - Frotscher, Ralf A1 - Staat, Manfred ED - Eberhardsteiner, J. T1 - Implementation of the edge-based smoothed extended finite element method T2 - Proceedings 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012 Y1 - 2012 ER -