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Your search keyword '"VISCOELASTICITY"' showing total 3 results
3 results on '"VISCOELASTICITY"'

1. Fabrication of Artificial Food Bolus for Evaluation of Swallowing.

Author

Hosotsubo, Miyu, Magota, Tetsuro, Egusa, Masahiko, Miyawaki, Takuya, and Matsumoto, Takuya

Subjects
*MASTICATION disorders, *ARTIFICIAL foods, *GELATIN, *MICROFABRICATION, *VISCOELASTICITY, *THERAPEUTICS
Abstract

Simple and easy methods to evaluate swallowing are required because of the recently increased need of rehabilitation for dysphagia. "Artificial food bolus", but not "artificial food", would be a valuable tool for swallowing evaluation without considering the mastication effect which is altered according to the individual's oral condition. Thus, this study was carried out to fabricate artificial bolus resembling natural food bolus. The mechanical property and the volume change of food bolus in normal people were firstly investigated. Thirty healthy adults without dysphagia were selected and asked to chew four sample foods (rice cake, peanut, burdock, and gummy candy). The results indicated that Young’s modulus of bolus before swallowing was below 150 kPa. The bolus volume before swallowing was below 400 mm3. In addition, the saliva component ratio of each bolus was approximately 30wt%, and the average saliva viscosity of research participants was approximately 10 mPa•s. Based on the obtained data, artificial food bolus was designed and fabricated by using alginate hydrogel as a visco-elastic material and gelatin solution as a viscotic material with a ratio of 7:3 based on weight. Consequently, the swallowing time of fabricated artificial food bolus was measured among the same participants. The results indicated the participants swallowed fabricated food bolus with similar manner reflecting their mechanical property and volume. Thus, this artificial food bolus would be a promising tool for evaluation of swallowing. [ABSTRACT FROM AUTHOR]

Published
2016
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2. Functional Properties of Glutinous Rice Flour by Dry-Heat Treatment.

Author

Qin, Yang, Liu, Chengzhen, Jiang, Suisui, Cao, Jinmiao, Xiong, Liu, and Sun, Qingjie

Subjects
*RICE starch, *HEAT treatment, *FOOD industry, *VISCOELASTICITY, *ENDOTHERMIC reactions
Abstract

Glutinous rice flour (GRF) and glutinous rice starch (GRS) were modified by dry-heat treatment and their rheological, thermal properties and freeze-thaw stability were evaluated. Compared with the native GRF and GRS, the water-holding ability of modified GRF and GRS were enhanced. Both the onset and peak temperatures of the modified samples increased while the endothermic enthalpy change decreased significantly (p < 0.05). Meanwhile, dry heating remarkably increased the apparent viscosities of both GRF and GRS. Importantly, compared with GRS samples, the storage modulus (G') and loss modulus (G") values of modified GRF increased more greatly and the tanδ values decreased more remarkably, indicating that the dry-heat treatment showed more impact on the GRF and a higher viscoelasticity compared with GRS. Our results suggest the dry-heat treatment of GRF is a more effective method than that of GRS, which omits the complex and tedious process for purifying GRS, and thereby has more practical applications in the food industry. [ABSTRACT FROM AUTHOR]

Published
2016
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3. Effects of moisture content and tillage methods on creep properties of paddy soil

Author

Xia Junfang, Liu Guoyang, Cheng Jian, Li Dong, Zheng Kan, and Du Jun

Subjects
0106 biological sciences, business.product_category, Compaction, Physical Chemistry, Polynomials, 01 natural sciences, Plough, Soil, Materials Physics, Agricultural Soil Science, Relaxation Time, Water content, Multidisciplinary, Moisture, Viscosity, Physics, Classical Mechanics, Eukaryota, Agriculture, Viscoelasticity, 04 agricultural and veterinary sciences, Plants, Deformation, Tillage, Chemistry, Experimental Organism Systems, Agricultural soil science, Physical Sciences, Medicine, Research Article, Science, Materials Science, Material Properties, Soil Science, Soil science, Research and Analysis Methods, Rivers, Plant and Algal Models, Grasses, Relaxation (Physics), Damage Mechanics, Organisms, Biology and Life Sciences, Water, Elasticity, Algebra, Chemical Properties, Models, Chemical, Soil water, Earth Sciences, Animal Studies, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Environmental science, Rice, business, Mathematics, 010606 plant biology & botany
Abstract

The rheological properties parameters of paddy soil affect the interaction between the tillage tools and soil, thus influencing the operation quality and power consumption. In order to study the effects of tillage methods and moisture content on the rheological properties parameters of paddy soil in the middle and lower reaches of the Yangtze River, uniaxial compression creep tests of paddy soils with four moisture contents under no tillage (moisture contents: 26.71%, 24.52%, 23.26%, 21.28%) and plough tillage (moisture contents: 26.77%, 25.55%, 23.40%, 20.56%) were carried out using a TMS-PRO texture analyzer. The creep properties curves obtained from the tests, and the rheological constitutive equation of paddy soil under compression was established by Burgers viscoelastic model. Respectively, the quantitative change rules of creep properties of paddy soil with different moisture contents under different tillage methods and the correlation between these parameters were explored. The results showed that the moisture content under the three-year plough tillage and no tillage methods had significant influence on the rheological properties parameters of paddy soil (P < 0.05). The instantaneous elastic modulus, delay elastic modulus, and viscosity coefficient of the two paddy soils (no tillage and plough tillage soils) decreased with the increase of moisture content. However, the variation rules of relaxation time and delay viscosity coefficient with moisture content differed between these two paddy soils. Specifically, the strain rate of the two paddy soils decreased as moisture content decreased, where the total strain combines elastic strain, viscous strain, and viscoelastic strain. The initial strain rate and steady strain rate of the plough tillage paddy soils were lower than that of the no tillage paddy soils. The established creep model equation could be used to obtain viscoelastic rheological parameters of paddy soil in a wide range. The fitting equations between rheological parameters and moisture content were introduced into Burgers model, and the coupling equations between creep deformation and moisture content and time were derived, which could be used to predict the creep properties and deformation behavior of paddy soil in a certain range of no tillage and ploughed field. Overall, this study has a certain theoretical significance for the development and improvement of paddy soil rheology theory, and can also provide theoretical basis and technical support for the research of agricultural machinery design optimization, field water, soil conservation, soil tillage and compaction related simulation analysis in the middle and lower reaches of the Yangtze River.

Published
2021

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