@article{VersenErnstGulati2017, author = {Versen, Martin and Ernst, W. and Gulati, P.}, title = {A row hammer pattern analysis of DDR2 SDRAM}, series = {Microelectronics Reliability}, volume = {76-77}, journal = {Microelectronics Reliability}, pages = {64 -- 67}, year = {2017}, abstract = {A DDR2 SDRAM test setup implemented on the Griffin III ATE test system from HILEVEL Technologies is used to analyse the row hammer bug. Row hammer pattern experiments are compared to standard retention tests. The analysis confirms that the row hammer effect is caused by a charge excitation process depending on the number of stress activation cycles. The stress has to occur in the local neighborhood of the cells under test. Shallow impurity levels support the responsible charge carrier transport process in the used DDR2 SDRAM technology}, language = {en} } @article{Schemme2008, author = {Schemme, Michael}, title = {Longfibre reinforced thermoplastics - status and perspectives}, series = {Plastics, Additives and Compounding}, volume = {10}, journal = {Plastics, Additives and Compounding}, number = {2}, pages = {38 -- 43}, year = {2008}, language = {de} } @article{Schemme2008, author = {Schemme, Michael}, title = {LFT - development status and perspectives}, series = {Reinforced Plastics}, volume = {52}, journal = {Reinforced Plastics}, number = {1}, pages = {32 -- 39}, year = {2008}, language = {en} } @article{PecqueurMaltenbergerPetrukhinaetal.2016, author = {Pecqueur, S{\´e}bastien and Maltenberger, Anna and Petrukhina, Marina A. and Halik, Marcus and Jaeger, Arndt and Pentlehner, Dominik and Schmid, G{\"u}nter}, title = {Bismut-haltige p-Dotanden mit großer Bandl{\"u}cke f{\"u}r optoelektronische Anwendungen}, series = {Angewandte Chemie}, journal = {Angewandte Chemie}, number = {128(35)}, publisher = {Wiley-VCH Verlag}, address = {Weinheim}, year = {2016}, abstract = {Zehn neue p-Dotanden f{\"u}r die Leitf{\"a}higkeitsdotierung von organischen Halbleitern wurden identifiziert. Der wesentliche Vorteil der elektrophilen Tris(carboxylato)-Bismut(III)-Verbindungen ist die niedrige Absorption der damit dotierten Schichten. Diese Eigenschaft zusammen mit ihren niedrigen Herstellungskosten sowie der guten Verdampfbarkeit und Stabilit{\"a}t macht diese Dotanden sehr attraktiv f{\"u}r Anwendungen in der organischen Elektronik.}, language = {de} } @article{PecqueurMaltenbergerPetrukhinaetal.2016, author = {Pecqueur, S{\´e}bastien and Maltenberger, Anna and Petrukhina, Marina A. and Halik, Marcus and Jaeger, Arndt and Pentlehner, Dominik and Schmid, G{\"u}nter}, title = {Wide Band-Gap Bismuth-based p-Dopants for Opto-Electronic Applications}, series = {Angewandte Chemie International Edition}, journal = {Angewandte Chemie International Edition}, number = {55}, publisher = {Wiley-VCH Verlag}, address = {Weinheim}, year = {2016}, abstract = {Ten new efficient p-dopants for conductivity doping of organic semiconductors for OLEDs are identified. The key advantage of the electrophilic tris(carboxylato) bismuth(III) compounds is the unique low absorption of the resulting doped layers which promotes the efficiency of OLED devices. The combination of these features with their low fabrication cost, volatility, and stability, make these materials very attractive as dopants in organic electronics.}, language = {en} } @article{LazarJarre2016, author = {Lazar, Markus and Jarre, F.}, title = {Calibration by Optimization Without Using Derivatives}, series = {Optimization and Engineering}, volume = {2016}, journal = {Optimization and Engineering}, number = {17/4}, publisher = {Springer}, pages = {833 -- 860}, year = {2016}, abstract = {Applications in engineering frequently require the adjustment of certain parameters. While the mathematical laws that determine these parameters often are well understood, due to time limitations in every day industrial life, it is typically not feasible to derive an explicit computational procedure for adjusting the parameters based on some given measurement data. This paper aims at showing that in such situations, direct optimization offers a very simple approach that can be of great help. More precisely, we present a numerical implementation for the local minimization of a smooth function f:Rn→R subject to upper and lower bounds without relying on the knowledge of the derivative of f. In contrast to other direct optimization approaches the algorithm assumes that the function evaluations are fairly cheap and that the rounding errors associated with the function evaluations are small. As an illustration, this algorithm is applied to approximate the solution of a calibration problem arising from an engineering application. The algorithm uses a Quasi-Newton trust region approach adjusting the trust region radius with a line search. The line search is based on a spline function which minimizes a weighted least squares sum of the jumps in its third derivative. The approximate gradients used in the Quasi-Newton approach are computed by central finite differences. A new randomized basis approach is considered to generate finite difference approximations of the gradient which also allow for a curvature correction of the Hessian in addition to the Quasi-Newton update. These concepts are combined with an active set strategy. The implementation is public domain; numerical experiments indicate that the algorithm is well suitable for the calibration problem of measuring instruments that prompted this research. Further preliminary numerical results suggest that an approximate local minimizer of a smooth non-convex function f depending on n≤300 variables can be computed with a number of iterations that grows moderately with n.}, language = {en} } @article{KrommesTomaschko2021, author = {Krommes, Sandra and Tomaschko, Florian}, title = {Chance f{\"u}r mehr Ressourceneffizienz - Methode der Wert- und Stoffstromanalyse im Kontext der digitalen Transformation bestehender Fertigungsanlagen}, series = {Zeitschrift f{\"u}r wirtschaftlichen Fabrikbetrieb (zwf)}, volume = {116}, journal = {Zeitschrift f{\"u}r wirtschaftlichen Fabrikbetrieb (zwf)}, number = {1-2}, publisher = {De Gruyter}, address = {Berlin}, pages = {58 -- 63}, year = {2021}, abstract = {Die dynamische Wert- und Stoffstrommodellierung bildet die In- und Output-Str{\"o}me von Prozessen mittels Digitalisierungstechnologien ab. In einem aus f{\"u}nf Schritten bestehenden methodischen Vorgehen kann der Einstieg in die Digitalisierung der Produktion f{\"u}r KMU mit bestehenden Anlagen- und Maschinenparks (Brownfield-Ansatz) gelingen: Ein digitaler Schatten erm{\"o}glicht ein echtzeit- und realdatenbasiertes Monitoring von Einzel- und Kleinserienfertigungen zur Steigerung der Ressourceneffizienz. Method of Value and Material Flow Analysis within the Digital Transformation of a Brownfield Approach. Dynamic value and material flow modeling maps input and output flows of processes by means of digitization. In a methodical approach consisting of five steps, SMEs with existing plant and machine parks (brownfield approach) can be successfully introduced to the digitization of production: A digital shadow of a defined process enables a real-time and real data-based monitoring and key figure system for individual and small series production.}, language = {de} } @article{HummelObermeierZieretal.2022, author = {Hummel, Sabine and Obermeier, Katharina and Zier, Katja and Krommes, Sandra and Schemme, Michael and Karlinger, Peter}, title = {Analysis of Mechanical Properties Related to Fiber Length of Closed-Loop-Recycled Offcuts of a Thermoplastic Fiber Composites (Organo Sheets)}, series = {Materials}, volume = {15}, journal = {Materials}, number = {11}, pages = {3872}, year = {2022}, abstract = {Increasing demand for energy-efficient means of transport has steadily intensified the trend towards lightweight components. Thermoplastic glass fiber composites (organo sheets) play a major role in the production of functional automotive components. Organo sheets are cut, shaped and functionalized by injection molding to produce hybrid components, such as those used in car door modules. The cutting process produces a considerable amount of production waste, which has thus far been thermally recycled. This study develops a closed mechanical recycling process and analyzes the different steps of the process. The offcuts were shredded using two shredding methods and implemented directly in the injection-molding process. Using tensile tests and impact bending tests, the material properties of the recycled materials were compared with the virgin material. In addition, fiber length degradation via the injection-molding process and the influence of the waterjet-cutting process on the mechanical properties are investigated. Recycled offcuts are both comparable to new material in terms of mechanical properties and usability, and are also economically and ecologically advantageous. Recycling polypropylene waste with glass fiber reinforcement in a closed loop is an effective way to reduce industrial waste in a sustainable and economical production process.}, language = {en} } @article{HirschmuellerPravidaMarteetal.2018, author = {Hirschm{\"u}ller, Sebastian and Pravida, Johann and Marte, Roman and Flach, Michael}, title = {Adhesive properties of laminated veneer lumber poles for use in temporary soil nailing: bonding performance of curved structures in a high-alkaline environment}, series = {Wood Science and Technology}, volume = {52}, journal = {Wood Science and Technology}, number = {5}, editor = {Springer,}, pages = {1289 -- 1311}, year = {2018}, abstract = {Circular hollow sections of beech-laminated veneer lumber (LVL) for the use as temporary geotechnical soil nailing systems are currently being developed. Due to their permanent subsoil cement embedment, investigations of the bond line quality of the timber sections are essential. This paper presents the bonding properties of flat and curved beech LVL after cyclic conditioning in a water-cement grout solution aimed at inducing short- and long-term alkaline attack of the timber. In total, 409 and 69 samples were tested in tensile shear tests after short-term and long-term conditioning, respectively. Three different adhesive systems, a one-component polyurethane adhesive, a melamine-urea-formaldehyde adhesive and a melamine-urea-formaldehyde adhesive modified by means of (polyvinyl)-acetate adhesive were investigated and compared. Short-term conditioning by submersion in boiling cement suspension was found to be a reliable method for testing the bonding performance rather than long-term conditioning. In the case of tensile shear tests of samples subjected to long-term treatment, wood material strength was the decisive criterion. Generally, tensile shear test samples of all investigated adhesives achieved reliable bonding for a pressing force up to 1.0 MPa. No relationship was recognised between the determined bonding failure and the wood properties tensile shear strength, wood failure percentage, fracture pattern and bulk density of veneers adjacent to the bond line. For the determination of the bond line integrity of curved veneer poles, it was necessary to test bonding quality in a combined test using curved and flat samples and to compare tensile shear strength with data determined on reference samples in the same veneer population without bond line.}, language = {en} } @article{HirschmuellerPravidaMarteetal.2018, author = {Hirschm{\"u}ller, Sebastian and Pravida, Johann and Marte, Roman and Flach, Michael}, title = {Adhesive properties of laminated veneer lumber poles for use in temporary soil nailing: development and evaluation of a test method for curved structures in a high-alkaline environment}, series = {Wood Science and Technology}, volume = {52}, journal = {Wood Science and Technology}, number = {4}, editor = {Springer,}, pages = {1061 -- 1092}, year = {2018}, abstract = {Innovative circular, hollow, laminated veneer lumber (LVL) beech sections for use as temporary geotechnical soil reinforcement members are currently being developed. Appropriate surface gluing quality between the veneers is fundamental to this subsoil application of the permanently cement-embedded, engineered timber product. The circular cross-section geometry and the permanently high-alkaline environment of the structural member is not covered by presently standardized testing and conditioning methods for examining LVL surface bond line quality. The sample conditioning and tensile shear test method compliant with EN 302-1 (Adhesives for load-bearing timber structures—test methods—part 1: determination of longitudinal tensile shear strength, European Committee for Standardization, Brussels, 2013) was modified to determine bonding parameters for circular, hollow LVL sections. Bond line curvature, groove cutting depth and sample geometry were found to greatly influence stress distribution, percentage of wood failure and tensile shear strength. Short-term alkaline treatment of test samples did not significantly influence the bonding performance, wood failure percentage, tensile shear strength and fracture patterns. To improve tensile shear strength, adhesives with different material rigidities were used and compared. An orthotropic, elastic numerical analysis revealed a greater influence of adherent elasticity than adhesive elasticity on the stress distribution within the bond line. With regard to determining the bond line integrity of curved veneer poles, a sample geometry compliant with EN 302-1 (2013) was developed and numerically evaluated.}, language = {en} }