Phase equilibria, physical and rheological properties of extracellular polymeric substances in the aqueous urea solutions at different temperatures and concentrations

During the production of beer, and especially beer wort, the main wastes are spent grain and hot trub, i.e., the so-called “hot break.” Combined with yeast after fermentation, they represent the most valuable wastes. Hot trub is also one of the most valuable by-products. Studies on the chemical composition of these sediments and their rheological properties as waste products will contribute to their effective disposal and even further use as valuable pharmaceutical and cosmetic raw materials. So far, hot trub has been studied for morphology and particle distribution depending on the raw material composition and beer wort extract. However, there are no preliminary studies on the rheological properties of hot trub and hops. In particular, no attention has yet been paid to the dependence of these properties on the hop variety or different protein sources used. The aim of this study was to examine the effect of different hopping methods on hot trub viscosity and beer wort physicochemical parameters. Additionally, the hop solutions were measured at different temperatures. A microbiological analysis of hop sediments was also performed to determine the post-process survival of selected microorganisms in these wastes. For manufacturers of pumps used in the brewing industry, the most convenient material is that of the lowest viscosity. Low viscosity hot trub can be removed at lower velocities, which reduces costs and simplifies washing and transport. The sediments also had similar equilibrium viscosity values at high shear rates.

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Influence of biopolymers on the rheological properties of seafloor sediments and the runout behavior of submarine debris flows

Scientific Reports ◽

10.1038/s41598-021-81186-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jun Kameda ◽

Hamada Yohei

Keyword(s):

Rheological Properties ◽

Debris Flows ◽

Extracellular Polymeric Substances ◽

Flow Behavior ◽

Mass Movement ◽

Rheological Parameters ◽

Natural Environments ◽

Natural Systems ◽

Chemical Conditions ◽

Seafloor Sediments

AbstractSubmarine debris flows are mass movement processes on the seafloor, and are geohazards for seafloor infrastructure such as pipelines, communication cables, and submarine structures. Understanding the generation and run-out behavior of submarine debris flows is thus critical for assessing the risk of such geohazards. The rheological properties of seafloor sediments are governed by factors including sediment composition, grain size, water content, and physico-chemical conditions. In addition, extracellular polymeric substances (EPS) generated by microorganisms can affect rheological properties in natural systems. Here we show that a small quantity of EPS (~ 0.1 wt%) can potentially increase slope stability and decrease the mobility of submarine debris flows by increasing the internal cohesion of seafloor sediment. Our experiments demonstrated that the flow behavior of sediment suspensions mixed with an analogue material of EPS (xanthan gum) can be described by a Herschel–Bulkley model, with the rheological parameters being modified progressively, but not monotonously, with increasing EPS content. Numerical modeling of debris flows demonstrated that the run-out distance markedly decreases if even 0.1 wt% of EPS is added. The addition of EPS can also enhance the resistivity of sediment to fluidization triggered by cyclic loading, by means of formation of an EPS network that binds sediment particles. These findings suggest that the presence of EPS in natural environments reduces the likelihood of submarine geohazards.

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Rheological Properties of Tomato Concentrate

International Journal of Food Engineering ◽

10.2202/1556-3758.1470 ◽

2008 ◽

Vol 4 (7) ◽

Cited By ~ 7

Author(s):

Manish Dak ◽

Radha Charan Verma ◽

S N A Jaaffrey

Keyword(s):

Rheological Properties ◽

Absolute Temperature ◽

Power Law Model ◽

Arrhenius Model ◽

Rotational Viscometer ◽

Consistency Coefficient ◽

Flow Behaviour Index ◽

Different Temperatures ◽

Wide Gap ◽

Good Agreement

Rheological properties of tomato concentrate were evaluated using a wide-gap rotational viscometer (Brookfield Engineering Laboratories: Model LVDV-II) at different temperatures of 20, 30, 40, 50, and 60oC, at concentration of 18, 12.18 and 8.04 % total solids, and at appropriate shear rate(1-100 RPM). The power law model was fitted to the experimental results. The values of flow behaviour index (n) were found less than unity (0.23 to 0.82) at all the temperature and the concentration indicating shear-thinning (pseudoplasticity) behaviour of the concentrate. The correlation between the observed consistency coefficient ranging from 0.09 to 65.87 Pa.sn and the inverse absolute temperature has been exhibited by Arrhenius model. Consistency coefficient increased exponentially with increase in the concentration. Statistical model was used for prediction of the consistency coefficient as a function of temperature and concentration which showed a good agreement (r2=0.99) between experimental and theoretical values. The magnitude of activation energy were found to be in the range of 8.6 to 14.08 kJ/mol.K.

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Analysis of the relationship of extracellular polymeric substances to the dewaterability and rheological properties of sludge treated by acidification and anaerobic mesophilic digestion

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2019.02.012 ◽

2019 ◽

Vol 369 ◽

pp. 31-39 ◽

Cited By ~ 12

Author(s):

Siwei Zhang ◽

Jialin Liang ◽

Jinjia Huang ◽

Shaosong Huang ◽

Li Zheng ◽

...

Keyword(s):

Rheological Properties ◽

Extracellular Polymeric Substances ◽

Mesophilic Digestion ◽

Relationship Of ◽

The Relationship

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RHEOLOGICAL ANALYSIS OF VEGETABLE OILS USED FOR BIODIESEL PRODUCTION IN BRAZIL

Revista de Engenharia Térmica ◽

10.5380/reterm.v14i2.62129 ◽

2015 ◽

Vol 14 (2) ◽

pp. 31 ◽

Cited By ~ 1

Author(s):

L. E. Silva ◽

C. A. C. Santos ◽

J. E. S. Ribeiro ◽

C. C. Souza ◽

A. M. S. Sant’Ana

Keyword(s):

Shear Stress ◽

Rheological Properties ◽

Vegetable Oils ◽

Rheological Behavior ◽

Apparent Viscosity ◽

Biodiesel Production ◽

Viscosity Data ◽

Concentric Cylinder ◽

Lower Shear ◽

Different Temperatures

Rheology attempts to define a relationship between the stress acting on a given material and the resulting deformation and/or flow that takes place. Thus, the knowledge of rheological properties of fluid materials such as vegetable oils generates auxiliary data that can be used in its storage and application. In this context, the aim of this study was to evaluate the rheological behavior of vegetable oils (cotton, canola, sunflower, corn and soybean) at different temperatures, using four rheological models (Ostwald- de-Waelle, Herschel-Bulkley, Newton and Bingham). The rheological properties were determined using a Thermo Haake rheometer with concentric cylinder geometry. Measurements were taken at 30, 45 and 60 °C by controlling the temperature using a thermostatic bath coupled to the equipment. The software Rheowin Pro Job Manager was used for process control and data record. The rheograms were obtained by measuring the values of shear stress varying the shear rate from 100 to 600 s-1 within 250 seconds. For the analysis of the apparent viscosity at different shear rates was applied simple linear regression until 2nd degree with the aid of SAS (SAS/Stat 9.2) program. The apparent viscosity data were submitted to analysis of variance and the averages were compared by Tukey test at 5% of probability. Higher temperatures of the samples were correlated to lower shear stress values, hence lower values for viscosity and consistency index were obtained, since it is known that the density and viscosity are highly sensitive to temperature and that the increase in temperature results in reduction of viscosity, benefiting the fluid flow. The models of Newton and Ostwald-de-Waelle were chosen to evaluate the rheological behavior of the samples, showing a good fit for the rheological data.

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