Chemistry Reference
In-Depth Information
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Swiss Federal Institute of Technology (ETH) Zurich, Switzerland
At the laboratory of food process engineering, the UVP-PD technique
was developed and tested from 1994 onwards (Windhab, 1994). Af-
ter finishing his PhD (Ouriev, 2000), Boris Ouriev published several
articles. Ouriev
et al.
(2000) deal with measurements of fat suspen-
sions with different solid fat concentrations and flow rates. Ouriev and
Windhab (2002) applied power law and Herschel-Bulkley models to
a shear-thinning suspension of cornstarch in silicon oil and a shear-
thickening suspension of cornstarch in glucose syrup. Ouriev (2002)
gave details on wall slip measurements of shear-thickening suspension.
UVP-PD measurements in chocolate suspension and the influence of
seeding with pre-crystallised cocoa butter were presented by Ouriev
et al.
(2003). Ouriev and Windhab (2004) investigated transient flows
of non-Newtonian model suspensions. Ouriev
et al.
(2004) presented
results on measurements in partly pulsating chocolate flow and corre-
sponding power law fits. Fischer
et al.
(2009) compared in- and off-line
measurements in a viscoelastic surfactant solution. Due to a limited
spatial resolution and missing velocity profile data towards the pipe
walls, it was not possible to detect the expected banding flow. During
a stay at ETH Zurich, J. Wiklund and M. Johansson made measure-
ments in shear-thinning surfactant solutions and cellulose suspension
and fitted the results to power law and Herschel-Bulkley models. The
results were also compared with off-line rheometer measurements. A
part of the findings were presented by Wiklund
et al.
(Wiklund
et al.
2001, 2002). In the course of his PhD work, Birkhofer (2007) made
in-line measurements of the acoustic properties and rheology of cocoa
butter crystal suspensions (Birkhofer
et al.
, 2004, 2008) as well as model
suspensions.
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Swedish Institute for Food and Biotechnology (SIK)
Gothenburg, Sweden
Wiklund continued with a PhD work (Wiklund, 2007) at SIK develop-
ing the UVP-PD technique mainly for the food industry. Wiklund
et al.
(2006) presented a comparative LDA-UVP study on highly concentrated
cellulose fibre suspensions. Results showed that the UVP-PD method
can be used to determine the yield stress of such suspensions, directly
in-line, and that an important concentration gradient exists close to the
wall, which was confirmed later by Wiklund
et al.
(2008). Wiklund
et al.
(2007) presented results of the UVP-PD measurements of various food
systems such as cheese sauce, fruit yoghurt and a vegetable sauce. The
aim of those trials was to test the applicability of the UVP-PD method
to highly concentrated polydisperse suspensions containing anisotropic
