@article{36983,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>The use of structured measuring systems to prevent wall slip is a common approach to obtain absolute rheological values. Typically, only the minimum distance between the measuring surfaces is used for further calculation, implying that no flow occurs between the structural elements. But this assumption is misleading, and a gap correction is necessary. To determine the radius correction <jats:inline-formula><jats:alternatives><jats:tex-math>$$\Delta r$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
                <mml:mrow>
                  <mml:mi>Δ</mml:mi>
                  <mml:mi>r</mml:mi>
                </mml:mrow>
              </mml:math></jats:alternatives></jats:inline-formula> for specific geometries, we conducted investigations on three Newtonian fluids (two silicon oils and one suspension considered to be Newtonian in the relevant shear rate range). The results show that <jats:inline-formula><jats:alternatives><jats:tex-math>$$\Delta r$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
                <mml:mrow>
                  <mml:mi>Δ</mml:mi>
                  <mml:mi>r</mml:mi>
                </mml:mrow>
              </mml:math></jats:alternatives></jats:inline-formula> is not only shear- and material-independent, but geometry-dependent, providing a Newtonian flow behaviour in a similar viscosity range. Therefore, a correction value can be determined with only minute deviations in different Newtonian fluids. As the conducted laboratory measurements are very time-consuming and expensive, a CFD-approach with only very small deviations was additionally developed and compared for validation purposes. Therefore, simulation is an effective and resource-efficient alternative to the presented laboratory measurements to determine <jats:inline-formula><jats:alternatives><jats:tex-math>$$\Delta r$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
                <mml:mrow>
                  <mml:mi>Δ</mml:mi>
                  <mml:mi>r</mml:mi>
                </mml:mrow>
              </mml:math></jats:alternatives></jats:inline-formula> for the correction of structured coaxial geometries even for non-Newtonian fluids in the future.</jats:p>}},
  author       = {{Josch, Sebastian and Jesinghausen, Steffen and Dechert, Christopher and Schmid, Hans-Joachim}},
  issn         = {{0035-4511}},
  journal      = {{Rheologica Acta}},
  keywords     = {{rheology, rheometry, suspension, coaxial, correction}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Experimental and simulative determination and correction of the effective gap extension in structured coaxial measuring systems}}},
  doi          = {{10.1007/s00397-023-01383-2}},
  year         = {{2023}},
}

@article{31035,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>Further innovation in the field of selective laser sintering (SLS) is strongly connected to the availability of new materials since the market is dominated by polyamide 12 (&gt;90%). The aim of this publication is to develop a descriptive model for the droplet formation process in a Filament Extension Atomizer to predict the applicability to exploit further polymers for the SLS process. The feasibility was tested, investigated and characterized using a “Dripping out of a nozzle” setup for uniaxial extension. The droplet formation process was then observed via high-speed camera imaging and classified for certain parameters. The experiments were carried out using semi-diluted polyethylene oxide (600–4000 kg/mol), glycerol and water solutions as model fluids. Driven by the Plateau-Rayleigh instability, different types of spherical droplets were observed and various droplet formation mechanisms demonstrated and analyzed. Based on the experimental results, a predictive model is derived to describe various essential parameters.</jats:p>}},
  author       = {{Neukötter, Moritz and Jesinghausen, Steffen and Schmid, Hans-Joachim}},
  issn         = {{0035-4511}},
  journal      = {{Rheologica Acta}},
  keywords     = {{Rheology, SLS, Lasersintering, exensional rheology}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Model droplet formation in extensional filament stretching within a Filament Extension Atomizer}}},
  doi          = {{10.1007/s00397-022-01339-y}},
  year         = {{2022}},
}

@article{26125,
  abstract     = {{We investigated an explanation for the length dependence of apparent wall slip in capillary and slit die experiments that had been implied in earlier studies. Firstly, we used a very long slit die fitted with six equidistant pressure transducers and an adjustable outlet. It was found that, all other parameters being equal, the impact of pressure on the flow behavior of suspensions was not different from the impact on the unfilled matrix fluid. Particle-related properties, such as apparent wall slip, were therefore not influenced by pressure as assumed by other authors. Secondly, we determined wall slip velocities by both the Mooney method and numerical simulation, based on an implementation of Phillips constitutive equation for particle migration. This led to a similar length dependence of wall slip as had been reported in an earlier work. We concluded that this was due to the transient nature of particle migration and its interrelationship with apparent wall slip, rather than an influence of pressure.}},
  author       = {{Pieper, Sven and Kirchhoff, Nadine and Schmid, Hans-Joachim}},
  issn         = {{0035-4511}},
  journal      = {{Rheologica Acta}},
  pages        = {{69--75}},
  title        = {{{Absence of pressure sensitivity of apparent wall slip in pressure-driven flow of non-colloidal suspensions}}},
  doi          = {{10.1007/s00397-014-0815-x}},
  year         = {{2014}},
}

@article{35370,
  author       = {{Schmidt, Gudrun and Müller, Stefan and Schmidt, Claudia and Richtering, Walter}},
  issn         = {{0035-4511}},
  journal      = {{Rheologica Acta}},
  keywords     = {{Condensed Matter Physics, General Materials Science}},
  number       = {{6}},
  pages        = {{486--494}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Rheo-optical investigations of lyotropic mesophases of polymeric surfactants}}},
  doi          = {{10.1007/s003970050201}},
  volume       = {{38}},
  year         = {{1999}},
}

@proceedings{35368,
  editor       = {{Schmidt, Claudia and Navard, Patrick}},
  issn         = {{0035-4511}},
  keywords     = {{Condensed Matter Physics, General Materials Science}},
  number       = {{6}},
  pages        = {{485--485}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{EURORHEO 99-1 in Sophia-Antipolis, France}}},
  doi          = {{10.1007/s003970050200}},
  volume       = {{38}},
  year         = {{1999}},
}

@article{35372,
  author       = {{Quijada-Garrido, Isabel and Siebert, Hartmut and Becker, Patrick and Friedrich, Christian and Schmidt, Claudia}},
  issn         = {{0035-4511}},
  journal      = {{Rheologica Acta}},
  keywords     = {{Condensed Matter Physics, General Materials Science}},
  number       = {{6}},
  pages        = {{495--502}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Transient rheological behavior of tumbling side-chain liquid crystal polymers and determination of their λ parameters}}},
  doi          = {{10.1007/s003970050202}},
  volume       = {{38}},
  year         = {{1999}},
}

@article{35376,
  author       = {{Siebert, Hartmut and Grabowski, David A. and Schmidt, Claudia}},
  issn         = {{0035-4511}},
  journal      = {{Rheologica Acta}},
  keywords     = {{Condensed Matter Physics, General Materials Science}},
  number       = {{6}},
  pages        = {{618--627}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Rheo-NMR study of a non-flow-aligning side-chain liquid crystal polymer in nematic solution}}},
  doi          = {{10.1007/bf00367357}},
  volume       = {{36}},
  year         = {{1997}},
}