scholarly journals Some Rheological Properties of Katakuri (Erythronium japonicum Decne) Starch Pastes at Low Concentrations.

1993 ◽  
Vol 40 (3) ◽  
pp. 291-298
Author(s):  
Rieko AIKAWA ◽  
Sayuri AKUZAWA ◽  
Shigeru SAWAYAMA ◽  
Akiko KAWABATA ◽  
Michinori NAKAMURA
Keyword(s):  
Rheological Properties ◽  
Low Concentrations ◽  
Erythronium Japonicum

Solution Rheology of Saline and Polysaccharide Systems

2006 ◽  
Author(s):  
Ekmagage Don N. Almeida ◽  
Leela Rakesh ◽  
Stanley Hirschi ◽  
Anja Mueller
Keyword(s):  
Rheological Properties ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Water Soluble ◽  
Effluent Treatment ◽  
High Concentration ◽  
Concentrated Suspension ◽  
Cross Model ◽  
Low Concentrations ◽  
Pharmaceutical Industries

The problem of the characterization of the solution properties of water soluble polymers is long-standing. These polymers tend to form aggregated supramolecular gels that are resistant to molecular dispersion. These materials are being widely used in a variety of industrial applications. Their principle functions are as rheological modifiers, where they thicken or gel solutions in products such as hair-care, detergents, air fresheners and foods; as flocculants for particle separation as applied to water clarification, sewage, and effluent treatment, and as stabilizers to control the properties of concentrated suspension and emulsions, for example in paints, pesticides, dyes, and pharmaceutical industries. Therefore it is important to understand their rheological properties under various operating conditions such as stress, strain, temperature etc, which will induce gelation. The rheological properties of starch gels of high concentration (up to 86% starch) have been investigated before [1]. In this paper we have investigated experimentally the shear viscosity and viscoelasticity properties of saline and polysaccharide suspensions at various low concentrations and pH at different temperatures using controlled stress and strain rheometers (Vilastic-3 and AR 2000). The data were then fitted with the power law and Cross model for low and higher concentrations respectively. The present results show that the viscosity/elasticity does not significantly change for low concentrations at different pH values. The maximum viscosity/elasticity was obtained around pH 5-7.4 at higher concentrations.

scholarly journals Co-Supplementation of Flos Sophorae Extract with Tremella fuciformis Polysaccharides Improves Physicochemical, Textural, Rheological, and Antioxidant Properties of Low-Fat Yogurts

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Renyong Tang ◽  
Yurong Lu ◽  
Caiyun Hou ◽  
Jiaxuan Peng ◽  
Wei Wang ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Rheological Properties ◽  
Antioxidant Properties ◽  
Sensory Properties ◽  
Low Fat ◽  
Fermentation Time ◽  
Tremella Fuciformis ◽  
Low Concentrations ◽  
Health Promoting ◽  
Water Holding

Flos Sophorae extract (FSE) with abundant rutin and Tremella fuciformis polysaccharides (TP) could act as novel natural improvers of low-fat yogurt due to their health benefits and properties of interacting with proteins. This study attempted to understand how FSE or its combination with TP influences physicochemical, textural, and antioxidant properties of low-fat yogurts. The results indicated that the low concentrations of FSE (1.2 or 2.4%) increased the antioxidant activity, prompted the S. thermophilus growth, water holding capacity (WHC), and textural and sensory properties, and shortened the fermentation time, but reduced the rheological properties of yogurts compared with the control. Co-supplementing appropriate TP with the optimum FSE concentration (2.4%) improved the rheological properties, and further enhanced the S. thermophilus growth, WHC, textural and antioxidant properties, and sensory scores of yogurts compared with the 2.4% FSE group, with the best effects at 0.4 mg/mL TP. Taken together, co-supplementation of polyphenols extract FSE with Tremella fuciformis polysaccharides may be an available strategy to optimize health-promoting properties and overcome defects of low-fat yogurts.

scholarly journals Investigation of the dependences of the rheology of calcium alginate solutions on concentration, temperature and shear rate

2021 ◽  
Vol 83 (1) ◽  
pp. 100-105
Author(s):  
S.S. Karpova ◽  
◽  
A.K. Ospanova ◽  
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Calcium Alginate ◽  
Room Temperature ◽  
Practical Interest ◽  
Capillary Viscometer ◽  
Organic Salts ◽  
Calcium Salts ◽  
Low Concentrations ◽  
Object Of Study

The main problem: The rheological properties of calcium salts are of theoretical and practical interest for a modern researcher. The theoretical interest is primarily related to the search for general patterns and manifestations of the rheological properties of solutions of calcium salts. The practical component is based on the search for patterns and dependencies of the properties of solutions on the structure and composition of the object of study. Such chemicals as calcium salts are of particular practical interest, they are widely used in various fields, such as the food, chemical and pharmacological industries. Hydrophilic high-molecular solutions of alginates, namely calcium alginate, are actively used in the preparation of soft dosage forms, the manufacture of jelly masses in confectionery, act as thickeners in the food industry. They are characterized by a fairly high percentage of viscosity at low concentrations, bioavailability, prolonging effect, absence of irritating properties, biocompatibility with many polymers, which is especially important in the pharmaceutical industry and medicine. The use of calcium salts for these purposes is currently very promising, since these organic salts have a number of unique properties associated with gelation. Purpose: This paper contains the results of studying the features of the rheology of calcium alginate solutions. A concentration range of 0.1-0.7 % was chosen for the studies, which is sufficient to avoid gelation at room temperature. The dependence of viscosity on concentration, temperature (in the range of 25-45 °C) and shear rate were studied. Methods: Analysis of theoretical sources, observation, comparison of results. The rheological characteristics of the obtained substances were studied using a capillary viscometer. The measurements were carried out in the temperature range of 25-45°C. Results and their significance: it was found that there is a significant dependence of viscosity on concentration and temperature. For concentrations of 0.3 – 0.7 %, a similar type of dependence is observed, in contrast to solutions with a concentration of 0.1 % . Explanations of these dependencies were proposed.

The Rheological Properties of κ-Carrageenan-Konjac Gum Mixed Gel

2013 ◽  
Vol 781-784 ◽  
pp. 1652-1655
Author(s):  
Yu Wei ◽  
Yuan Lan Wang
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Modulus Of Elasticity ◽  
Small Amplitude ◽  
Plastic Behavior ◽  
Rheological Analysis ◽  
Low Concentrations ◽  
Konjac Gum

The rheological properties of κ-Carrageenan-Konjac Gum Mixed Gel were investigated by using dynamic rheological analysis. Results showed that the mixture of κ-Carrageenan and Konjac Gum had higher modulus of elasticity than single κ-Carrageenan or Konjac Gum. Blends solution has a good pseudo-plastic behavior at low concentrations, viscosity declined rapidly with shear rate increased. K+ and Ca2+ participated in the gelatin process and under the controlled condition might enhance force among molecules. With the temperature increasing G' and G" increased, and G' and G" presented suddenly change at 60-70 °C. Small amplitude oscillatory tests in the linear domain of viscoelasticity showed that κ-Carrageenan played the major role in the viscoelasticity of the mixture, and Konjac gum strengthened the gel-net configuration and stability.

scholarly journals The Study of the Influence of Chemical Nature of Functional Groups in Oligomeric and Low--Molecular Modifiers on the Rheological Properties of the Epoxy Oligomer

2021 ◽  
Vol 15 (1) ◽  
pp. 53-60
Author(s):  
Elena Barabash ◽  
◽  
Yuriy Popov ◽  
Yuliya Danchenko ◽  
◽  
...  
Keyword(s):  
Rheological Properties ◽  
Structure Formation ◽  
Intermolecular Interaction ◽  
Functional Groups ◽  
Dynamic Viscosity ◽  
Chemical Nature ◽  
Epoxy Oligomer ◽  
Epoxy System ◽  
Intermolecular Interaction Energy ◽  
Low Concentrations

The influence of chemical nature of modifier functional groups on the level of intermolecular interactions in the system "epoxy oligomer ‒ modifier", as well as the structure formation and dynamic viscosity of epoxy oligomer has been studied in detail. Modifying additives in low concentrations contribute to an increase in the degree of structure formation of the epoxy system by increasing the intermolecular interaction between the associates of the epoxydiane oligomer. It was established that the strength of the formed coagulation structures depends both on the compatibility parameter of the modifiers and ED-20, and on their intermolecular interaction energy.

Microtubule nucleation sequence studied by time-resolved x-ray scattering and electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 766-767
Author(s):  
Eva-Maria Mandelkow ◽  
Eckhard Mandelkow ◽  
Joan Bordas
Keyword(s):  
Electron Microscopy ◽  
Dynamic Equilibrium ◽  
Time Resolved ◽  
X Ray ◽  
Additional Information ◽  
X Ray Scattering ◽  
Low Concentrations ◽  
Microtubule Growth ◽  
Ray Patterns ◽  
Ray Scattering

When a solution of microtubule protein is changed from non-polymerising to polymerising conditions (e.g. by temperature jump or mixing with GTP) there is a series of structural transitions preceding microtubule growth. These have been detected by time-resolved X-ray scattering using synchrotron radiation, and they may be classified into pre-nucleation and nucleation events. X-ray patterns are good indicators for the average behavior of the particles in solution, but they are difficult to interpret unless additional information on their structure is available. We therefore studied the assembly process by electron microscopy under conditions approaching those of the X-ray experiment. There are two difficulties in the EM approach: One is that the particles important for assembly are usually small and not very regular and therefore tend to be overlooked. Secondly EM specimens require low concentrations which favor disassembly of the particles one wants to observe since there is a dynamic equilibrium between polymers and subunits.

The CM120 Biotwin: a high-contrast objective lens, optimum cryo-vacuum and improved EDX performance

1995 ◽  
Vol 53 ◽  
pp. 584-585
Author(s):  
Uwe Lücken ◽  
Michael Felsmann ◽  
Wim M. Busing ◽  
Frank de Jong
Keyword(s):  
Life Science ◽  
Focal Length ◽  
Objective Lens ◽  
High Contrast ◽  
Contrast Imaging ◽  
X Ray ◽  
Forming Mechanism ◽  
Similar Image ◽  
High Contrast Imaging ◽  
Low Concentrations

A new microscope for the study of life science specimen has been developed. Special attention has been given to the problems of unstained samples, cryo-specimens and x-ray analysis at low concentrations.A new objective lens with a Cs of 6.2 mm and a focal length of 5.9 mm for high-contrast imaging has been developed. The contrast of a TWIN lens (f = 2.8 mm, Cs = 2 mm) and the BioTWTN are compared at the level of mean and SD of slow scan CCD images. Figure 1a shows 500 +/- 150 and Fig. 1b only 500 +/- 40 counts/pixel. The contrast-forming mechanism for amplitude contrast is dependent on the wavelength, the objective aperture and the focal length. For similar image conditions (same voltage, same objective aperture) the BioTWIN shows more than double the contrast of the TWIN lens. For phasecontrast specimens (like thin frozen-hydrated films) the contrast at Scherzer focus is approximately proportional to the √ Cs.

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