TY - JOUR
AB - This paper presents the results of an interlaboratory study of the rheological properties of cement paste and ultrasound gel as reference substance. The goal was to quantify the comparability and reproducibility of measurements of the Bingham parameters yield stress and plastic viscosity when measured on one specific paste composition and one particular ultrasound gel in different laboratories using different rheometers and measurement geometries. The procedures for both in preparing the cement paste and carrying out the rheological measurements on cement paste and ultrasound gel were carefully defined for all of the study’s participants. Different conversion schemes for comparing the results obtained with the different measurement setups are presented here and critically discussed. The procedure proposed in this paper ensured a reasonable comparability of the results with a coefficient of variation for the yield stress of 27% and for the plastic viscosity of 24%, despite the individual measurement series’ having been performed in different labs with different rheometers and measurement geometries.
AU - Haist, Michael
AU - Link, Julian
AU - Nicia, David
AU - Leinitz, Sarah
AU - Baumert, Christian
AU - von Bronk, Tabea
AU - Cotardo, Dario
AU - Eslami Pirharati, Mahmoud
AU - Fataei, Shirin
AU - Garrecht, Harald
AU - Gehlen, Christoph
AU - Hauschildt, Inga
AU - Ivanova, Irina
AU - Jesinghausen, Steffen
AU - Klein, Christopher
AU - Krauss, Hans-W.
AU - Lohaus, Ludger
AU - Lowke, Dirk
AU - Mazanec, Oliver
AU - Pawelczyk, Sebastian
AU - Pott, Ursula
AU - Radebe, Nonkululeko W.
AU - Riedmiller, Joachim Jürgen
AU - Schmid, Hans-Joachim
AU - Schmidt, Wolfram
AU - Secrieru, Egor
AU - Stephan, Dietmar
AU - Thiedeitz, Mareike
AU - Wilhelm, Manfred
AU - Mechtcherine, Viktor
ID - 21949
JF - Materials and Structures
KW - Rheology
KW - Wall Slip
KW - Slip
KW - apparent slip
KW - suspension
KW - cement
KW - concrete
SN - 1359-5997
TI - Interlaboratory study on rheological properties of cement pastes and reference substances: comparability of measurements performed with different rheometers and measurement geometries
ER -
TY - JOUR
AB - Since suspensions (e.g., in food, cement, or cosmetics industries) tend to show wall slip, the application of structured measuring surfaces in rheometers is widespread. Usually, for parallel-plate geometries, the tip-to-tip distance is used for calculation of absolute rheological values, which implies that there is no flow behind this distance. However, several studies show that this is not true. Therefore, the measuring gap needs to be corrected by adding the effective gap extension δ to the prescribed gap height H in order to obtain absolute rheological properties. In this paper, we determine the effective gap extension δ for different structures and fluids (Newtonian, shear thinning, and model suspensions that can be adjusted to the behavior of real fluids) and compare the corrected values to reference data. We observe that for Newtonian fluids a gap- and material-independent correction function can be derived for every measuring system, which is also applicable to suspensions, but not to shear thinning fluids. Since this relation appears to be mainly dependent on the characteristics of flow behaviour, we show that the calibration of structured measuring systems is possible with Newtonian fluids and then can be transferred to suspensions up to a certain particle content.
AU - Pawelczyk, Sebastian
AU - Kniepkamp, Marieluise
AU - Jesinghausen, Steffen
AU - Schmid, Hans-Joachim
ID - 21948
JF - Materials
KW - wall slip prevention
KW - effective gap height
KW - parallel-plate system
KW - structured surfaces
KW - model suspensions
KW - cement paste
KW - fresh concrete
SN - 1996-1944
TI - Absolute Rheological Measurements of Model Suspensions: Influence and Correction of Wall Slip Prevention Measures
ER -
TY - JOUR
AU - Gonchikzhapov, Munko
AU - Kasper, Tina
ID - 32490
IS - 18
JF - Industrial & Engineering Chemistry Research
KW - Industrial and Manufacturing Engineering
KW - General Chemical Engineering
KW - General Chemistry
SN - 0888-5885
TI - Decomposition Reactions of Fe(CO)5, Fe(C5H5)2, and TTIP as Precursors for the Spray-Flame Synthesis of Nanoparticles in Partial Spray Evaporation at Low Temperatures
VL - 59
ER -
TY - JOUR
AU - Otroshi, M.
AU - Rossel, Moritz Sebastian
AU - Meschut, G.
ID - 20691
JF - Journal of Advanced Joining Processes
SN - 2666-3309
TI - Stress state dependent damage modeling of self-pierce riveting process simulation using GISSMO damage model
ER -
TY - CHAP
AB - Als zeitgenössischer Komponist, dessen Werke von einem christlich-humanistischen Geist getragen werden, fühlt sich Stefan Heucke (*1959) unverkennbar der Tradition der deutschen Kunstmusik ab dem 18. Jahrhundert verpflichtet.
Das Verzeichnis seiner Werke lässt Stefan Heucke mit den "Drei Liedern nach Gedichten von Georg Trakl" op. 1 beginnen, die Ende der 1970er Jahre entstanden sind. Spätestens seit Mitte der 1980er Jahre, als er mit der Uraufführung seiner "Vier Orchesterstücke" op. 5 beim "Forum junger deutscher Komponisten für Orchestermusik" ausgezeichnet wurde, ist Heucke als Komponist in der Öffentlichkeit präsent. Sein Werkkatalog ist seither auf annähernd 100 Kompositionen angewachsen, die eindrucksvoll belegen, dass er als Komponist die musikalischen Gattungen in ihrer Breite bedient: Opern und Oratorien stehen neben Sinfonien, Konzerten und geistlicher Musik ebenso wie Kammermusik und Liedern.
AU - Höink, Dominik
ED - Tadday, Ulrich
ID - 36806
SN - 978-3-86916-829-6
T2 - Stefan Heucke
TI - Komponierte Erinnerungskultur in traditioneller Form? Eine Annäherung an Stefan Heuckes Oratorium "Nikolaus Groß" op. 62
VL - 187
ER -
TY - CHAP
AU - Tumat, Antje
ED - Wiesenfeldt, Christiane
ID - 36823
SN - 978-3-7618-2071-1
T2 - Mendelssohn-Handbuch
TI - Musik für das Theater
ER -
TY - JOUR
AU - Niewöhner, Nadine
AU - Asmar, Laban
AU - Röltgen, Daniel
AU - Kühn, Arno
AU - Dumitrescu, Roman
ID - 37122
JF - Procedia CIRP
KW - General Medicine
SN - 2212-8271
TI - The impact of the 4th industrial revolution on the design fields of innovation management
VL - 91
ER -
TY - CHAP
AU - Schmidt, Jochen
ED - Dockter, Cornelia
ED - Dürnberger, Martin
ED - Langefeld, Aaron
ID - 36956
KW - Theologie
KW - dialektik
T2 - Theologische Grundbegriffe. Ein Handbuch
TI - Dialektische Theologie
ER -
TY - BOOK
AU - Schuh, Günther
AU - Anderl, Reiner
AU - Dumitrescu, Roman
AU - Krüger, Antonio
AU - ten Hompel, Michael
ID - 37125
TI - Der Industrie 4.0 Maturity Index in der betrieblichen Anwendung. Aktuelle Herausforderungen, Fallbeispiele und Entwicklungstrends (acatech KOOPERATION)
ER -
TY - JOUR
AB - Abstract
Mathematics learning support centres (MLSC) are widely established and evaluated in English-speaking countries (such as the UK, Ireland and Australia). In most of these countries, several national surveys on MLSCs exist. They give an overview of the number of MLSCs as well as their characteristics in these countries. In Germany, there is a lack of studies on MLSCs and the landscape of MLSCs has not been described yet. This article presents basic information concerning counts of MLSCs and their characteristics at universities. Based on a three-step approach of analysing university homepages and additional personal contact via email or phone calls, we gathered typical MLSC features (e.g. staff quantities and qualification, opening and support hours, supported study programmes). We analysed 190 universities from a web-based register on study programmes. In total, we found 61 MLSCs located at 51 German universities. Another 16 support centres were specialized on mathematics didactics, which means they focussed on didactical and methodological support for preservice teacher students and often provided different teaching materials. Thirty-eight centres were located at universities (62.3%) and 23 MLSCs at universities of applied sciences and comparable universities (37.7%). The MLSCs were different in their sizes of staff and opening hours, and both the numbers of staff and the service hours differed greatly. The student groups MLSCs at German universities focus on differ concerning characteristics like study programme or semester. We will provide the main categories describing these groups. We seek to answer research questions concerning the characteristics of MLSCs in Germany and discuss the results compared to international findings. This information is useful for further international collaborative research, for example a standardized international survey. From a national perspective, these findings support networking and collaborations between the MLSCs as well. As some German MLSCs are facing financial cuts, these results might help in gaining additional funding.
AU - Schürmann, Mirko
AU - Gildehaus, Lara
AU - Liebendörfer, Michael
AU - Schaper, Niclas
AU - Biehler, Rolf
AU - Hochmuth, Reinhard
AU - Kuklinski, Christiane
AU - Lankeit, Elisa
ID - 35712
IS - 2
JF - Teaching Mathematics and its Applications: An International Journal of the IMA
KW - Education
KW - General Mathematics
SN - 0268-3679
TI - Mathematics learning support centres in Germany—an overview
VL - 40
ER -