scholarly journals Manufacturing Condition Effects on Dynamic Viscoelastic Properties of High-amylose Rice Gel by High-speed Shear Treatment

2018 ◽  
Vol 24 (4) ◽  
pp. 739-746 ◽  
Author(s):  
Mario Shibata ◽  
Junichi Sugiyama ◽  
Kaori Fujita ◽  
Mito Kokawa ◽  
Yukari Hirano ◽  
...  
Keyword(s):  
Viscoelastic Properties ◽  
High Speed ◽  
Manufacturing Condition ◽  
High Amylose

scholarly journals Novel Method of Measuring Corneal Viscoelasticity Using the Corvis ST Tonometer

2022 ◽  
Vol 11 (1) ◽  
pp. 261
Author(s):  
Agnieszka Boszczyk ◽  
Henryk Kasprzak ◽  
Joanna Przeździecka-Dołyk
Keyword(s):  
Intraocular Pressure ◽  
Viscoelastic Properties ◽  
High Speed ◽  
Central Area ◽  
Biomechanical Properties ◽  
P Value ◽  
Corvis St ◽  
Corneal Deformation ◽  
The Times ◽  
High Repeatability

Background: The process of rapid propagation of the corneal deformation in air puff tonometer depends not only on intraocular pressure, but also on the biomechanical properties of the cornea and anterior eye. One of the biomechanical properties of the cornea is viscoelasticity, which is the most visible in its high-speed deformations. It seems reasonable to link the corneal viscoelasticity parameter to two moments of the highest speed of corneal deformations, when the cornea buckles. The aim of this work is to present a method of determining the time and place of occurrence of corneal buckling, examine spatial and temporal dependencies between two corneal applanations and bucklings in the Corvis ST tonometer, and correlate these dependencies with corneal viscoelastic properties. Methods: Images of the horizontal cross section of the Corvis ST deformed cornea from the air puff tonometer Corvis ST were used. 14 volunteers participated in the study, each of them had one eye measured eight times. Mutual changes in the profile slopes of the deformed corneas were numerically determined. They describe pure corneal deformation, eliminating the influence of rotation, and displacement of the entire eyeball. For each point in the central area of the corneal profile, the maximum velocities of mutual slope changes accompanying the applanations were estimated. The times of their occurrence were adopted as buckling times. Results: The propagation of buckling along the corneal profile is presented, as well as the repeatability and mutual correlations between the buckling parameters and intraocular pressure. Based on the relationship between them, a new parameter describing corneal hysteresis: Corvis Viscoelasticity (CVE) is introduced. It is characterized by high repeatability: ICC = 0.82 (0.69–0.93 CI) and low and insignificant correlation with intraocular pressure: r = 0.25 (p-value = 0.38). Conclusion: The results show for the first time how to measure the corneal buckling and viscoelastic effects with Corvis ST. CVE is a new proposed biomechanical parameter related to the viscoelastic properties of the cornea, which has high repeatability for the examined subject. The distribution of its values is planned to be tested on different groups of patients in order to investigate its clinical applicability.

Abrasion Resistance and High Speed Tensile Strength of Elastomers

1966 ◽  
Vol 39 (4) ◽  
pp. 823-840 ◽  
Author(s):  
Ruprecht Ecker
Keyword(s):  
Tensile Strength ◽  
Viscoelastic Properties ◽  
High Speed ◽  
Loss Modulus ◽  
Empirical Relation ◽  
Viscoelastic Behavior ◽  
Experimental Tests ◽  
Test Results ◽  
Resonant Vibrations ◽  
Mechanical Rupture

Abstract In earlier communications, we defined abrasion, especially of tires, as a thermal-oxidative process caused at high velocity of mechanical rupture. Other authors (e.g., Schallamach, Boggs, Zapp etc.), with theoretical and experimental tests, prove the importance of viscoelastic behavior as a characteristic property for abrasion. The results of experiments on six elastomers (NR, IR, BR, SBR, IIR, and EPT) compared in tire tread compounds are communicated and discussed in the present work. Tensile strength was determined over a temperature range of 20° to 140° C at deformation speeds of 10 to 20,000 % elongation per second. Forced, non-resonant vibrations were used to determine viscoelastic properties, e.g., resilience, storage modulus, and loss modulus. As abrasion is a consequence of frictional processes, coefficients of friction, dependent on temperature, were measured on dry, wet, and frosty asphalt/fine concrete track. The apparatus is briefly described. From these test results, an empirical relation established between abrasion, friction, viscoelastic properties, tensile strength at high speed and temperature allows one to predetermine the abrasion behavior of a vulcanizate in the laboratory.

Effect of retort treatment on physicochemical properties of high-amylose rice gel made by high-speed shear treatment

2018 ◽  
Vol 79 ◽  
pp. 335-340 ◽  
Author(s):  
Keisuke Isaka ◽  
Mario Shibata ◽  
Marin Osawa ◽  
Junichi Sugiyama ◽  
Tomoaki Hagiwara
Keyword(s):  
Physicochemical Properties ◽  
High Speed ◽  
High Amylose

Rheological scaling properties of starch solutions in dimethylsulfoxide

2012 ◽  
Vol 33 (3) ◽  
pp. 323-333 ◽  
Author(s):  
Paweł Ptaszek ◽  
Marcin Łukasiewicz ◽  
Anna Ptaszek ◽  
Mirosław Grzesik
Keyword(s):  
Viscoelastic Properties ◽  
Amylose Content ◽  
Concentration Function ◽  
Empirical Method ◽  
Observation Window ◽  
Scaling Properties ◽  
Continuous Relaxation ◽  
Waxy Starch ◽  
Tikhonov Regularisation ◽  
High Amylose

Abstract The possibility of scaling viscoelastic properties of starch solutions in relation to biopolymer concentration was presented in this study. An application of this empirical method enabled to widen the observation horizon of viscoelastic properties. It was also determined that the scope of its applicability is limited by amylose content in the solution. In high amylose solutions, for which up to 40% (w/w) concentration was the highest one obtained, calibration caused the formation of master curve in the widest frequency range. Determined values of scaling coefficients aC changed exponentially in starch concentration function in the solution. For waxy starch solutions of maximum concentration equal to 20% (w/w), scaling did not significantly widen the observation window. Based on master curves constructed in such way, continuous relaxation spectra H(λ) were determined using Tikhonov regularisation method. Their structure indicates advantageous of viscous elements in the process of viscoelastic phenomena formation.

Effect of a High-amylose Gel Prepared by High-speed Shear Treatment on the Physical Properties of Bread

2015 ◽  
Vol 62 (4) ◽  
pp. 212-218 ◽  
Author(s):  
Mario Shibata ◽  
Junichi Sugiyama ◽  
Kaori Fujita ◽  
Yukari Hirano ◽  
Mizuki Tsuta ◽  
...  
Keyword(s):  
Physical Properties ◽  
High Speed ◽  
High Amylose

Viscoelastic properties and bubble structure of rice-gel made from high-amylose rice and its effects on bread

2017 ◽  
Vol 73 ◽  
pp. 33-39 ◽  
Author(s):  
Mito Kokawa ◽  
Yoko Suzuki ◽  
Yukiko Suzuki ◽  
Masatoshi Yoshimura ◽  
Vipavee Trivittayasil ◽  
...  
Keyword(s):  
Viscoelastic Properties ◽  
Bubble Structure ◽  
High Amylose

Dynamic Viscoelastic Properties of Raw Butadiene—Acrylonitrile Elastomers

1974 ◽  
Vol 47 (4) ◽  
pp. 778-787 ◽  
Author(s):  
N. Nakajima ◽  
E. A. Collins ◽  
P. R. Kumler
Keyword(s):  
Shear Stress ◽  
Tensile Stress ◽  
Viscoelastic Properties ◽  
High Speed ◽  
Master Curve ◽  
Viscoelastic Behavior ◽  
Master Curves ◽  
Stress Strain ◽  
Strain Measurements ◽  
Using Data

Abstract The dynamic viscoelastic properties of four samples of butadiene—acrylonitrile raw elastomers, were obtained with a Rheovibron at 110 Hz and temperature range of −80 to 160°C. The complex properties were in agreement with the master curves obtained previously from stress-strain measurements. A master curve encompassing 13 decades of time was constructed using data from Mooney rheometer shear stress-strain, MTS high speed tensile stress-strain, and the Rheovibron. The master curve represents the rubbery region of viscoelastic behavior in terms of time, temperature, and the magnitude of deformation up to the breaking point. This study demonstrates that corresponding states can be found between small (ca. 1 per cent) and large deformation up to break (e.g., 1400 per cent).

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