The study of the mechanical impedance of foods and biomaterials to characterize their linear viscoelastic behavior at high frequencies

2008-09-01
A new instrumental setup, which is based on the oscillatory squeezing flow model, was developed to characterize the viscoelastic properties of foods and biopolymers. Analysis of the data was performed by two different approaches. The first approach employed principles of vibration to determine viscous damping and elasticity of the sample harmonically compressed between two plates. The second approach involved the use of additional calculations based on the squeezing flow model which were linked to concepts of vibration analysis, such as mechanical impedance, to determine fundamental rheological parameters like complex viscosity and related (elastic and viscous) moduli. The experimental setup for the method is simple to use and could be attached to existing commercial instruments such as texture analyzers and universal testing machines. The use of the proposed method with this type of instruments would provide them with the additional capability of performing dynamic rheological testing. The dynamic mass of the instrument was significantly low when compared to that of other instruments that use similar principles. This low dynamic mass enabled the use of relatively higher frequencies for the testing of the samples. Comparison of the viscous and elastic moduli obtained with the proposed method and from conventional rheometers for a variety of foods and biopolymers showed good agreements.
RHEOLOGICA ACTA

Suggestions

An Iterative Solution Approach to Coupled Heat and Mass Transfer in a Steadily Fed Evaporating Water Droplet
Akkus, Yigit; ÇETİN, BARBAROS; Dursunkaya, Zafer (ASME International, 2019-03-01)
Inspired by the thermoregulation of mammals via perspiration, cooling strategies utilizing continuously fed evaporating droplets have long been investigated in the field, yet a comprehensive modeling capturing the detailed physics of the internal liquid flow is absent. In this study, an innovative computational model is reported, which solves the governing equations with temperature-dependent thermophysical properties in an iterative manner to handle mass and heat transfer coupling at the surface of a const...
Determination of deep trapping center parameters in as-grown Tl2Ga2S3Se layered crystals
YILDIRIM, TACETTİN; Hasanlı, Nızamı (Elsevier BV, 2009-09-01)
Thermally stimulated current measurements were carried out on as-grown Tl2Ga2S3Se layered single crystals. The investigations were performed in temperatures ranging from 10 to 320 K with heating rates of 0.6-1.2 K s(-1). The analysis of the data revealed the hole trap level located at 498 meV. The activation energies of the traps have been determined using various methods of analysis, and they agree with each other. The calculation for these traps yielded 2.1 x 10(-18) cm(2) for capture cross-section and 2....
A new instrumental setup for determination of small amplitude viscoelastic properties of dough during fermentation
Mert, Behiç (Springer Science and Business Media LLC, 2008-05-01)
In this study, the working principles and the theoretical background of a new method to measure the viscoelastic properties of dough in the fermentation process are presented. During measurements, the dough sample was placed between a stationary bottom plate and an oscillating top plate and squeezed at random frequencies ranging from 10 to 100,000 rad/s. By measuring the required force and velocity of oscillations, the mechanical impedance of the samples, defined as the ratio of the force to oscillation vel...
A study of phase stability and mechanical properties of hydroxylapatite-nanosize alpha-alumina composites
Evis, Zafer (Elsevier BV, 2007-04-01)
Hydroxylapatite (HA)-nanosize alumina composites were synthesized to study their phase stability and mechanical properties. To make these composites, nanosize alpha-Al2O3 powder was used because of its better sinterability and densification as compared to nanosize gamma-Al2O3. The composites were air sintered without pressure and hot pressed in vacuum at 1100 degrees C and 1200 degrees C. In the composites, HA decomposed to tricalcium phosphate faster after the air sintering than hot pressing. Moreover, hex...
Comparison of the short and long-term degradation behaviors of as-cast pure Mg, AZ91 and WE43 alloys
Ocal, Ezgi Butev; ESEN, ZİYA; Aydınol, Mehmet Kadri; Dericioğlu, Arcan Fehmi (Elsevier BV, 2020-02-01)
The corrosion behaviors of pure magnesium, AZ91, and WE43 alloys have been evaluated by weight loss, hydrogen evolution rate, pH change measurements and potentiodynamic polarization as well as electrochemical impedance spectroscopy (EIS) methods. Main corrosion product formed on the surface of Mg/Mg-alloys after immersion of 24 h was Mg(OH)(2) on the other hand, at the end of the 20 days additional CaCO3 which was found to display a critical role in degradation characteristics of the samples, was found. Exa...
Citation Formats
B. Mert, “The study of the mechanical impedance of foods and biomaterials to characterize their linear viscoelastic behavior at high frequencies,” RHEOLOGICA ACTA, pp. 727–737, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/41680.