![]() ![]() The expression obtained for stress-induced migration can be viewed as a generalized nonequilibrium Stokes–Einstein relation. Owing to the axisymmetry of the motion about a spherical probe, the second normal stress difference is zero, while the first normal stress difference is linear in Pe for P e ≫ 1 and vanishes as P e 4 for P e ≪ 1. ![]() This relation is shown to agree with two standard micromechanical definitions of the stress, suggesting that the normal stresses and normal stress differences can be measured in nonlinear microrheological experiments if both the mean and mean-square motion of the probe are monitored. In this study, a connection is made between diffusion and stress gradients, and a relation between the particle-phase stress and the diffusivity and viscosity is derived for a probe particle moving through a colloidal dispersion. The notion that diffusive flux is driven by stress gradients leads to the idea that the stress can be related directly to the microdiffusivity, and thus the anisotropy of the diffusion tensor reflects the presence of normal stress differences in nonlinear microrheology. The viscosity and diffusivity can thus be obtained by two simple quantities-mean and mean-square displacement of the probe. Recent studies showed that the mean probe speed can be interpreted as the effective material viscosity, whereas fluctuations in probe velocity give rise to an anisotropic force-induced diffusive spread of its trajectory. Probe motion through the medium distorts the microstructure the character of this deformation, and hence its influence on probe motion, depends on the strength with which the probe is forced, F ext, compared to thermal forces, kT/b, defining a Péclet number, P e = F ext / ( k T / b ), where kT is the thermal energy and b is the characteristic microstructural length scale. In the absence of external forcing, the probe and background particles form an equilibrium microstructure that fluctuates thermally. Testing volume: Approx.In active, nonlinear microrheology, a Brownian “probe” particle is driven through a complex fluid and its motion tracked in order to infer the mechanical properties of the embedding material. And by fine-tuning your production based on analysis results you can improve quality control of milk and profitability. With MilkoScan Minor you can rapidly measure up to six key quality parameters from a single sample and remove the need for slow and expensive chemistry methods. Easy calibration adjustment, and data storage can all be carried out on an external PC. In less than 90 seconds you have the result. Just select product type and press the start button. The MilkoScan Minor is designed for ease of use. Pre-calibrated for milk and cream it enables on on-the-spot analysis so you can pay the right price for deliveries and control production more accurately. MilkoScan™ Minor allows smaller producers to get fast and accurate milk testing analysis. Inline process refraktometer iPR series.MeatScan™ for meat and sausage products.FoodScan™ for meat and sausage products.Analyzer for falling number Alphatec and hammer mill Hammertec.Laboratory mills for sample preparation.Fibertec™ Systems for crude fibre determination.Digestor™ Systems for Kjeldahl analysis. ![]()
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