• Korean Journal of Food Science and Technology
• /
• v.22 no.6
• /
• pp.646-650
• /
• 1990

To develop a new form of spice material by concentration of garlic juice, its rheological properties were investigated. In the temperature range of $15\;to\;65^{\circ}C$, the garlic juice with the solid content of $32\;to\;60^{\circ}Brix$ was considered as a pseudoplastic fluid. Flow and consistency indices of the juice interpreted by power-law equation varied from $0.9937\;to\;0.6130\;and\;0.0041\;to\;3.1886Pa{\;s^n$, respectively. Apparent viscosity was lineally decreased as shear rate was increased. Activation energy for the flow of the garlic juice changed in the range of 11,216 to 23,195 kJ/kg mol.

• Proceedings of the SCSK Conference
• /
• 1999.10a
• /
• pp.123-131
• /
• 1999

Liquid crystal known as a rheological barrier to coaleseence of oil dorplets. increases. emulsion stability, water-holding capacity and promotes active material penetration to skin. Some investigation for its rheological characteristics have been reported but its relations to consumer perception have been rarely published. In this study oil/water emulsion and oil/liquid crystal/water systems were manufactured using the same composition of Behenyltrimethylammonium chloride/Cetostearyl alcohol/Lanolin oil. and rheological properties of each system were investigated with Cone and Plate rheometer. The formation of liquid crystalline phase was observed with polarized microscope and Differential Scanning Calorimeter. Continuous shear experiment, creep yield and water holding capacity were measured for oil/water and oil/liquid crystal/water systems. The results were compared with sensory evaluations. Oil/liquid crystal/water system showed higher viscosity at the same shear rate, higher viscoelasticity and higher yield stress than oil/water system. These properties were expected to show good spreadability and excellent richness without waxiness I hair care products of creme type. This expectation was consistent with the results of sensory experiments. Water-holding capacity was evaluated by measuring residual water of specimens at specific temperature and relative humidity, Oil/liquid crystal/water system was proved to have ability to hold water in comparison with oil/water system. The results indicated that oil/liquid crystal/water system was of benefit to rheological properties creme type hair care products.

• Journal of the Korea Institute of Building Construction
• /
• v.8 no.2
• /
• pp.99-106
• /
• 2008

To improve concrete tensile strength and bending strength, New plan that have more economical and simple manufacture process is groped. By an alternative plan, chemical pre-stressed concrete is presented. In this study, we analyzed the rheological properties of cement paste with the kind and replacement ratio of k-type CSA type expansive additives that is used mainly in domestic. and we suggested that the algorithm of a mixing plan in the chemical pre-stressed concrete and from this, we presented the basic report for the right mixing plan. From the results, Flow increased more or less according to use of expansive additives. This phenomenon was observed by increasing paste amount that shows as substitution for expansive additives that specific gravity is smaller than that of cement. As linear regression a result supposing paste that mix expansive additives by Bingham plastic fluid. The shear rate and shear stress expressed high interrelationship. therefore, flow analysis of quantitative was available. The plastic viscosity following to replacement ratio of expansive additives is no change almost, the yield value is decreased in proportion to the added amount of expansive additives. Through this experiment, we could evaluate rheological properties of cement paste using the expansive additives. Hereafter by an additional experiment, we must confirm stability assessment of material separation by using the aggregate with the kind and replacement ratio of expansive additives.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.21 no.12
• /
• pp.1132-1137
• /
• 2011

MRE(magneto-rheological elastomers) is a material which shows reversible and various modulus in magnetic field. Comparing to conventional rubber vibration isolator, MREs are able to absorb vibration of broader frequency range. These characteristic phenomena result from the orientation of magnetic particles named carbonyl iron powder(CIP) in rubber matrix. In this paper, simulation on variation rate of shear modulus for anisotropic MRE due to volume fraction of CIP and an effective permeability model was applied to predict the field-induced shear modulus of MREs. Also, the variation rate of shear modulus for anisotropic MRE was derived using magneto-mechanical theory. Based on Maxwell-Garnett mixing rule, the increment of shear modulus was calculated to evaluate the shear modulus of MREs with column structure of CIP due to induced current. The simulation results on variation rate of shear modulus can be applied to the variable mechanical system of MRE such as tunable vibration absorber, stiffness variable bush and mount.

• Advances in concrete construction
• /
• v.9 no.1
• /
• pp.9-22
• /
• 2020

The present work looks at the possibilities of recycling more than once demolished concrete as coarse aggregates, to produce new concrete. Different concrete mixes were made with substitutions of 50%, 75% and 100% of recycled concrete aggregates respectively as coarse aggregates. The physico-mechanical characterization tests carried out on the recycled concrete aggregates revealed that they are suitable for use in obtaining a structural concrete. The resulting concrete materials had rheological parameters, compressive strengths and tensile strengths very slightly lower than those of the original concrete even when 100% of two cycles recycled concrete aggregates were used. The durability of the recycled aggregates concrete was assessed through water permeability, water absorption and chemical attacks. The obtained concretes were thought fit for use as structural materials. A linear regression was developed between the strength of the material and the number of cycles of concrete recycling to anticipate the strength of the recycled aggregates concrete. From the results, it appear clear that recycling demolished concrete represents a valuable resource for aggregates supply to the concrete industry and a the same time plays a key role in meeting the challenge for a sustainable development.

• Computers and Concrete
• /
• v.15 no.6
• /
• pp.903-919
• /
• 2015

The flow of freshly mixed cement-based material shows thixotropy, which implies some difficulties on robust measurement of its rheological properties: The flow curve of thixotropic materials depends on the used protocol. For examples, higher viscosity is obtained when the rate of shear strain is more quickly increased. Even though precise measurement and modelling of the concrete rheology needs to consider the thixotropic effect, engineers in the concrete field prefer considering as a non-thixotropic Herschel-Bulkley fluid, even more simply Bingham fluid. That is due to robustness of the measurement and application in casting process. In the aspect of simplification, this papers attempts to mimic the thixoropic flow by the non-thixotropic Herschel-Bulkley model. Disregarding the thixotropy of cement based materials allows us to adopt the rheological concept in the field. An optimized protocol to measure the Bingham parameters was finally found based on the accuracy and reproducibility test of cement paste samples, which minimizes the error of simulation stemming from the assumption of non-thixotropy.

• Korean Journal of Food Science and Technology
• /
• v.23 no.6
• /
• pp.759-763
• /
• 1991

The dynamic rheological properties of the dope and the hydrated disperson of the soyprotein, as a starting material of soyprotein fiber, were studied to investigate their viscoelastic properties. The increase of protein concentration in the both cases of the dope and the dispersion resulted in the establishment of intermolecular reaction of the protein. With the addition of alkali solution to the dispersion, the dope shows the characteristics of very lightly cross-linked high molecular weight polymer. In constrast, the dispersion shows the properties of an amorphorous polymer. The effects of chemical modification of the dispersion on the dynamic properties were also investigated.

• International Journal of Concrete Structures and Materials
• /
• v.1 no.1
• /
• pp.11-18
• /
• 2007

In the recent design of high ductile engineered cementitious composites (ECC), optimizing both processing and mechanical properties for specific applications is critical. This study employs a method to develop useful ECC produced with slag particles (slag-ECC) in the field, which possesses different fluid properties to facilitate diverse types of processing (i.e., self-consolidating or spray processing). Control of rheological modulation was regarded as a key factor to allow the performance of the desired processing while retaining the ductile material properties. To control the rheological properties of the composite, the basic slag-ECC composition was initially obtained, determined based on micromechanics and steady-state cracking theory. The stability and consequent viscosity of the suspensions were then mediated by optimizing the dosage of the chemical and mineral admixtures. The rheological properties altered through this approach were revealed to be effective in obtaining ECC-hardened properties, represented by pseudo strain-hardening behavior in uniaxial tension, allowing the readily achievement of the desired function of the fresh ECC.

• Smart Structures and Systems
• /
• v.25 no.5
• /
• pp.581-592
• /
• 2020

Magneto-rheological fluids and magneto-strictive materials are of the well-known smart materials which are used to control and reduce the vibrations of the structures. Vibration analysis of a smart annular three-layered plate is provided in this work. MR fluids are used as the core's material type and the face sheets are made from MS materials and is assumed they are fully bonded to each other. The structure is rested on visco-Pasternak foundation and also is subjected to a transverse magnetic field. The governing motion equations are derived based on CPT and employing Hamilton's principle and are solved via GDQ as a numerical method for various boundary conditions. Effect of different parameters on the results are considered and discussed in detail. One of the salient features of this work is the consideration of MR fluids as the core, MS materials as the faces, and all of them under magnetic field. The outcomes of this study may be led to design and create smart structures such as sensors, actuators and also dampers.

• Tribology and Lubricants
• /
• v.28 no.6
• /
• pp.333-339
• /
• 2012

Typical magneto-rheological (MR) elastomers consist of silicon-based material. A number of studies have been carried out to evaluate the vibration and tribological characteristics of silicon-based MR e-lastomers. However, these elastomers have quite low strength, so they have low wear resistance. In this study, polyurethane-based MR elastomers with performances better than those of MR elastomers. Experiments have been conducted on different MR elastomers (Pu MR elastomer, Pu-Si MR elastomer, and Pu-wrapped-Si MR elastomer) and different predefined magnetic directions (Non-Direction, Vertical Direction, and Horizontal Directionality) to evaluate the friction and wear performance under a magnetic field. The results show that Pu-wrapped-Si MR elastomer with a horizontal predefined magnetic field has the best performance in terms of wear.