Search

This paper presents the feasibility of developing an electromechanical in-situ viscosity measurement technique by analyzing the detectability of small variations in the viscosity of different shear thickening fluids and their different compositions. Shear thickening fluid (STF) is a kind of non-Newtonian fluid showing an increasing viscosity profile under loading. STF is utilized in several applications to take advantage of its tunable rheology. However, process control in different STF applications requires rheological measurements, which cause a costly investment and long-lasting labor. Therefore, one of the most commonly used in-situ structural health monitoring techniques, electromechanical impedance (EMI), was used in this study. In order to actuate the medium electromechanically, a piezoelectric wafer active sensor (PWAS) was used. The variations in the spectral response of PWAS resonator that can be submerged into shear thickening fluid are analyzed by the root mean square deviation, mean absolute percentage deviation and correlation coefficient deviation. According to the results, EMI metrics provide good correlations with the rheological parameters of STF and thereby enabling quick and low-cost rheological control for STF applications such as vibration dampers or stiffness control systems.

International audience; This paper covers the study of high-frequency (~ 1 GHz) ZnO piezoelectric transducer integrated on a silicon substrate able to generate both compressional and shear acoustic waves. First, to promote the longitudinal mode, an electrical matching of the transducer in this high-frequency range is effectuated. Second, to promote shear waves, new deposition conditions were applied, giving thin zinc oxide films of inclined c-axis. The RF microprobe was used to validate the transducer design and to conduct the viscosity measurements. Thus, the shear and the volume viscosity of a water droplet were measured.

The viscosity of the contents of the soft container could not be inspected by a non-destructive method. Therefore, we conducted an experimental study on whether the viscosity inspection of the contents of the soft container can be performed noncontact and non-destructively by measuring the vibration of the soft container due to the vibration of acoustic irradiation with a laser Doppler vibrometer. From the experimental results using the specimen, it was clarified that the viscosity of the soft container contents can be estimated without contact because the difference in vibration energy according to the viscosity of the soft container contents was detected.

The mechanical properties of biological cells, especially the elastic modulus and viscosity of cells, have been identified to reflect cell viability and cell states. The existing measuring techniques need additional equipment or operation condition. This paper presents a cell’s viscoelasticity measurement method based on the spheroidization process of non-spherical shaped cell. The viscoelasticity of porcine fetal fibroblast was measured. Firstly, we introduced the process of recording the spheroidization process of porcine fetal fibroblast. Secondly, we built the viscoelastic model for simulating a cell’s spheroidization process. Then, we simulated the spheroidization process of porcine fetal fibroblast and got the simulated spheroidization process. By identifying the parameters in the viscoelastic model, we got the elasticity (500 Pa) and viscosity (10 Pa·s) of porcine fetal fibroblast. The results showed that the magnitude of the elasticity and viscosity were in agreement with those measured by traditional method. To verify the accuracy of the proposed method, we imitated the spheroidization process with silicone oil, a kind of viscous and uniform liquid with determined viscosity. We did the silicone oil’s spheroidization experiment and simulated this process. The simulation results also fitted the experimental results well.

A new application of a high sensitivity magnetoelastic resonator able to measure period and damping constant of low frequency torsional oscillation is described and validated by experimental tests. The sensitive parameter is the amplitude of resonant magnetoelastic waves in the soft ferromagnetic core (Fe 62.5 Co 6 Ni 7.5 Zr 6 Cu 1 Nb 2 B 15 amorphous ribbon). The theoretical model of the device has been developed, correlating torsional oscillations to the friction force applied by the fluid in which they occur. Thus, an accurate indirect evaluation of fluid viscosity has been demonstrated. The main prerogative of the proposed sensor is to work without contact with the oscillating mechanism. As experimental validation, viscosity of UHT milk was measured versus different fat content. The experimental comparison with a standard rheometer demonstrates the new device competitiveness in the measure of low viscosity fluids at low share rate. Moreover, the detected behaviors at increasing temperature are in agreement with previous literature. In perspective, the new magnetoelastic resonators application can be very ductile and effective in on-line monitoring of viscosity change with time to control composition, degradation or contamination of liquids.

The first goal of this study is to identify the ideal piezoelectric material for the manufacturing of rheological reflectance ultrasonic sensors. The second goal is to integrate the ultrasonic rheometer within a gas absorption reactor and to measure viscosity changes in an ionic liquid (IL) caused by gas absorption. To achieve the objectives, bismuth titanate, lead titanate, lead metaniobate and lead zirconate titanate materials in layer, tungsten bronze and perovskite structures were assembled on aluminum delay lines and tested under thermal cycling between room temperature and 150 &deg, C. The results showed that lead metaniobate in tungsten bronze structure is the most suitable material for long time duration thermal cycling. Therefore, the ultrasonic rheometer was assembled using this material and installed in a pressurized reactor to test a reference IL at the operating conditions of 50 &deg, C and at a pressure of 80 bar. The reference IL was saturated with nitrogen as well as hydrogen gas. Viscosity signals remained constant under the hydrogen atmosphere, while in nitrogen atmosphere the absorption of the gas lead to a rise in the value of viscosity.

This paper reports on a new system for liquid density and viscosity measurement based on a freely suspended rectangular vibrating plate actuated by piezoelectric ceramic (PZT) actuators. The Lamb mode used for these measurements allows us to infer both the density and viscosity in a larger range as compared to the existing gold-standard techniques of MEMS resonators. The combination of the measured resonance frequency and quality factor enables extraction of density and viscosity of the surrounding liquid. The system is calibrated while performing measurements in water glycerol solutions with a density range from 997 to 1264 kg/m3 and viscosity from 1.22 to 985 mPa&middot, s, which is a larger dynamic range compared to existing mechanical resonators showing an upper limit of 700 mPa&middot, s. The out-of-plane vibrating mode exhibits quality factor of 169, obtained in deionized water (1.22 mPa&middot, s viscosity), and 93 for pure glycerol with a viscosity of 985 mPa&middot, s. This Lamb wave resonating sensor can achieve measurement in fairly large viscosity media while keeping a quality factor superior to 90. Measurements performed on oil validate the use of the Lamb system. Oil density is evaluated at 939 kg/m3 and dynamic viscosity at 43 mPa&middot, s which corresponds to our expected values. This shows the possibility of using the sensor outside of the calibration range.

A proprietary cell was designed and fabricated to investigate the density and viscosity of fluid at high pressure and elevated temperatures. In the first part of this study the results of density and viscosity measurement of a heavy oil sample in the absence of water are presented and the results for water/oil blends will be reported in the second part. A heavy oil from a reservoir in Western Alberta was used and its density and viscosity were measured using a special blind cell and a custom made inline viscometer respectively at pressure of 13.76 MPa (2000 psig) and elevated temperatures of up to 300 °C. Hysteresis was observed on density and viscosity of the heavy oil when it was cooled down after being exposed to elevated temperatures.

A systematic study regarding the liquid crystallinity of p-Aramid and MWCNTs composite at various p-Aramid and MWCNTs concentrations in sulphuric acid was investigated and optimized by solution viscosity measurement and opalescence observation. We observed a merged liquid crystalline phase consisting of both p-Aramid and MWCNTs, and we believe this is the first study to report this combined liquid crystalline phase in one suspension. In addition to providing fundamental insights, we envision this study could be useful to those developing a strong, light, and high-performance polymeric composite fibers.

The traditional method for determining mixing and compaction temperatures of asphalt binders, such as Brookfield viscosity test, often yields excessively high temperatures when used in many modified asphalts, and underestimates the temperature decreasing effect of the additives when used in warm-mixing asphalts. This study proposed a new viscosity measurement method, namely rotational plate viscosity (RPV) testing, to overcome these issues. The new method uses a Dynamic Shear Rheometer (DSR) with a 25-mm-diameter parallel plate geometry and a fixed shear rate 40 s−1 to measure the viscosity-temperature curve of modified asphalts, which minimizes the effect of the shear-thinning behavior. In addition, there are two main advantages of this new method. First, it can be carried out using an existing standard DSR machine typically used in most asphalt binder laboratories. Second, it can greatly improve the accuracy and efficiency of testing with sophisticated sensors and programmed settings.

In this paper, we report the characterization of the viscosity of biodiesel produced from jatropha curcas . The viscosity measurement has been carried out by using a modified falling ball viscometer as well as optical technology. The viscosity was measured from 28 to 70 °C, which is the interest for determining the quality of biodiesel. We found that the falling ball optical viscometer offers a resolution of a viscosity measurement of ±0.039 mPa s with a relative error of 1.47933%. The measurement process was compared with a commercial viscometer, and it has been demonstrated that the biodiesel produced in Chiapas has good quality.

Although good progress was made by two international benchmark exercises on in-plane permeability, existing methods have not yet been standardized. This paper presents the results of a third benchmark exercise using in-plane permeability measurement, based on systems applying the radial unsaturated injection method. 19 participants using 20 systems characterized a non-crimp and a woven fabric at three different fiber volume contents, using a commercially available silicone oil as impregnating fluid. They followed a detailed characterization procedure and also completed a questionnaire on their set-up and analysis methods. Excluding outliers (2 of 20), the average coefficient of variation (c v ) between the participant´s results was 32% and 44% (non-crimp and woven fabric), while the average c v for individual participants was 8% and 12%, respectively. This indicates statistically significant variations between the measurement systems. Cavity deformation was identified as a major influence, besides fluid pressure/viscosity measurement, textile variations, and data analysis. Fil: May, D.. Institut Für Verbundwerkstoffe Gmbh; Alemania Fil: Aktas, A.. National Physical Laboratory; Reino Unido Fil: Advani, S.G.. University Of Delaware; Estados Unidos Fil: Berg, D. C.. Technische Universität Clausthal; Alemania Fil: Endruweit, A.. University of Nottingham; Estados Unidos. Science and Technology Facilities Council of Nottingham. Rutherford Appleton Laboratory; Reino Unido Fil: Fauster, E.. Montanuniversitat Leoben; Austria Fil: Lomov, S. V.. Katholikie Universiteit Leuven; Bélgica Fil: Long, A.. University of Nottingham; Estados Unidos. Science and Technology Facilities Council of Nottingham. Rutherford Appleton Laboratory; Reino Unido Fil: Mitschang, P.. Institut Für Verbundwerkstoffe Gmbh; Alemania Fil: Abaimov, S.. Skolkovo Institute Of Science And Technology; Rusia Fil: Abliz, D.. Technische Universität Clausthal; Alemania Fil: Akhatov, I.. Skolkovo Institute Of Science And Technology; Rusia Fil: Ali, M. A.. Khalifa University Of Science And Technology; Emiratos Arabes Unidos Fil: Allen, T. D.. University of Auckland; Nueva Zelanda Fil: Bickerton, S.. University of Auckland; Nueva Zelanda Fil: Bodaghi, M.. Institute Of Science And Innovation In Mechanical And Industrial; Portugal Fil: Caglar, B.. Koç Üniversitesi; Turquía Fil: Caglar, H.. Koç Üniversitesi; Turquía Fil: Chiminelli, A.. Instituto Tecnologico de Aragon; España Fil: Correia, N.. Institute Of Science And Innovation In Mechanical And Industrial; Portugal Fil: Cosson, B.. Imt Lille Douai; Francia Fil: Danzi, M.. Eth Zürich; Suiza Fil: Dittmann, J.. Universität Stuttgart; Alemania Fil: Ermanni, P.. Eth Zürich; Suiza Fil: Francucci, Gaston Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: George, A.. University Brigham Young; Estados Unidos Fil: Grishaev, V.. Skolkovo Institute Of Science And Technology; Rusia Fil: Hancioglu, M.. Koç Üniversitesi; Turquía Fil: Kabachi, M. A.. Eth Zürich; Suiza Fil: Kind, K.. Universitat Technical Zu Munich; Alemania Fil: Deléglise Lagardère, M.. Imt Lille Douai; Francia Fil: Laspalas, M.. Instituto Tecnologico de Aragon; España Fil: Lebedev, O. V.. Skolkovo Institute Of Science And Technology; Rusia Fil: Lizaranzu, M.. Instituto Tecnologico de Aragon; España Fil: Liotier, P. J.. Université de Lyon; Francia Fil: Middendorf, P.. Universität Stuttgart; Alemania Fil: Morán, J.. Universidad Nacional de Mar del Plata; Argentina Fil: Park, C. H.. Imt Lille Douai; Francia Fil: Pipes, R. B.. Purdue University; Estados Unidos Fil: Pucci, M. F.. Université de Montpellier; Austria Fil: Raynal, J.. Groupe Institut de Soudure; Francia Fil: Rodriguez, E. S.. Universidad Nacional de Mar del Plata; Argentina Fil: Schledjewski, R.. Montanuniversitat Leoben; Austria Fil: Schubnel, R.. Groupe Institut de Soudure; Francia Fil: Sharp, N.. Purdue University; Estados Unidos Fil: Sims, G.. National Physical Laboratory; Reino Unido Fil: Sozer, E. M.. Koç Üniversitesi; Turquía Fil: Sousa, P.. Katholikie Universiteit Leuven; Bélgica Fil: Thomas, J.. Khalifa University Of Science And Technology; Emiratos Arabes Unidos Fil: Umer, R.. Khalifa University Of Science And Technology; Emiratos Arabes Unidos Fil: Wijaya, W.. University of Auckland; Nueva Zelanda Fil: Willenbacher, B.. Institut Für Verbundwerkstoffe Gmbh; Alemania Fil: Yong, A.. National Physical Laboratory; Reino Unido Fil: Zaremba, S.. Universitat Technical Zu Munich; Alemania Fil: Ziegmann, G.. Technische Universität Clausthal; Alemania

Biomodels made of poly(vinyl alcohol) (PVA) are demanded because they can represent the geometries and mechanical properties of human tissues realistically. Injecting and molding, commonly used in three-dimensional (3D) modeling, help to represent the blood vessels accurately. However, these techniques sometimes require higher pressures than the upper pressure limit of the dispensers for pouring in high viscosity materials; the material viscosity should therefore be lower. Moreover, the mechanical properties of the biomodels should be reproduced. This study proposes a PVA solution through the addition of xanthan gum (XG) for 3D modeling, which lowers liquid viscosity while maintaining the mechanical properties of biomodels. XG is known to facilitate the achievement of non-Newtonian fluidity; however, the effects of XG on a PVA solution and PVA hydrogel (PVA-H) are not confirmed. The viscosity measurement using 15 wt% PVA with XG solution (PVA/XG) shows that it will provide easier pouring than 17 wt% PVA solution. The tensile test using the PVA-H of PVA(15 wt%)/XG(0.2 wt%) reveals that the gel is comparable in Young’s modulus to 17 wt% PVA-H. X-ray diffraction shows the crystalline structures of the PVA/XG gel and PVA-H are identical. Thus, this PVA/XG would be useful for fabricating biomodels using injection molding techniques.

In this work, possible use of FeSiB amorphous magnetic wire as a magnetoelastic sensor was investigated. As-received wire did not show any magnetoelastic change. But, the wire annealed in a furnace at 465 ∘C for various times showed good magnetoelastic change. A very large change in the resonance frequency of annealed FeSiB wire as a function of DC magnetic field was obtained. This large change was explained on the basis of the high value of magnetostriction of FeSiB wire and the increase in the rotational magnetization process. It was also found that resonance frequency of FeSiB wire changes when the wire was in a liquid with different viscosities.

This paper presents an active sensing system for concrete viscosity measurement during its very early age. The proposed system is based on the analysis of energy transmission at the boundary of interface between probe (stainless steel bar in the system) and concrete mixture. Different from traditional systems, which employed a couple of actuator and sensor attaching to the surface of the concrete, the new system employs only one transducer as both actuator and sensor. Therefore, the system could be integrated in a small size and more portable. Since only one transducer is employed, the viscosity change of early age concrete is extracted by analyzing the energy variation of the reflected ultrasonic waves instead of applying traditional digital signal processing (DSP) technique (magnitude, phase, velocity). Laboratory experiments are carried out to evaluate the effect of this approach. Results show good match with theoretical analysis. This system can be used in large-scale field investigation of concrete viscosity monitoring for bridges, highways and airport pavements.

The main aim of this paper is to characterize experimentally the flow behaviour of the green sand that is used for casting of sand moulds. After the sand casting process is performed, the sand moulds are used for metal castings. The rheological properties of the green sand is important to quantify as they can be used to evaluate whether the casting process will be successful. In addition, the properties can potentially be implemented in a computational fluid dynamics model which can be used as a tool to optimize the process. The rheological experiments are carried out on a MCR 502 rheometer with a new module for characterizing granular materials. The new module enables viscosity measurements of the green sand as function of the shear rate at different flow rates, i.e. 0, 2, 4, 6, 8, 10, 12 and 15 L/min. The results show generally that the viscosity decreases with both the shear- and flow rate. In addition, the measurements show that the green sand flow follows a shear-thinning behaviour even after the full fluidization point.

The use of modified asphalt binders has become much more common over the past two decades. Many types of modifier have been used in paving asphalts to enhance the performance of asphalt pavements in a wide range of climates and loading conditions. Among various asphalts binder modifiers, the recycled crumb rubber has been used very successfully for many years. Generally in production of CRM binder, mixing and compaction temperature is determined by measuring of binder viscosity. The ordinary method used for viscosity measurement of unmodified binder leads to a very high Mixing and Compaction Temperature (MCT) for CRM binder. The aims of this paper are to identify, develop and give some recommendations on a reliable laboratory approach for blending of CRM with binder, as well as introducing appropriate laboratory test methods for optimisation of MCT of crumb rubber modified binder asphalt. © (2013) Trans Tech Publications, Switzerland.

A simple method of viscosity measurement is useful for cooking nursing care meal requiring suitable viscosity for each patients' swallow ability. The purpose of this study is the viscosity measurement for controlling viscosity without protruding any sensor into vessel. Proposed sensor consists of a radial mode piezoelectric resonator embedded in vessel bottom. Electrical impedance of the resonator was measured to obtain equivalent circuit parameters. As a result, the change of the equivalent capacitance linearly responds to the viscosity. Ratio of root mean square errors of estimated viscosity against viscosity of each samples were less than 25 % in the range of 42–229 mPa·s.

This paper is attempted to establish a practical shear rate for optimum compaction temperature determination of modified asphalt binders in asphalt mixture design. Viscosity of seven modified asphalt binders was measured, optimum compaction temperatures of eight asphalt mixtures were obtained and the shear rate range during roller compaction was estimated. Results showed that in the shear rate measuring range of commonly used Brookfield viscometer (0.3–25 s−1), viscosity characteristics at 25 s−1 showed the best similarity to viscosity characteristics during roller compaction in the shear rate range of 10–130 s−1. Also, viscosity at the shear rate of 25 s−1 exhibited the best correlation with the minimum compaction energy index of asphalt mixtures at optimum compaction temperatures. Based on the results above, 25 s−1 was suggested as the practical shear rate, providing a direct viscosity measurement for optimum compaction temperature determination of modified asphalt binders in asphalt mixture design.

Plastics are made of polymers and additives. For good processability special additives are necessary. Some additives were used for a better ejection and flow behavior. To get a proper classification of additives, new in-line measurements were developed. The flow behavior of plastics can be determined with an in-line viscosity measurement in an injection mold. To classify the ejection behavior during the injection molding process, the demolding force and the normal force were used. The new in-line measurement allows a detailed classification of processing aids in plastics.

For many applications the viscosity of a complex fluid sample is interesting to control the process and reactions. These fluids can for instance be suspensions of different types of microorganisms, e.g., bacteria or fungi. Macroscopic viscosity measurement systems would only be able to measure the global, averaged viscosity. Miniaturized TSM resonators, however, are probing only a very thin fluid film (typically only a few μm thick, depending on frequency and viscosity) on their surface. Earlier investigations with water-in-oil micro-emulsions have shown that the influence of water droplets in oil is dependent of their size. In this paper we focus on a similar effect, i.e. the influence of the surface roughness. It turns out that the sensor behaves differently if the dimension of the inclusions or particles is in the order of the surface roughness.

There has been an increasing awareness of the role of zero shear viscosity (ZSV) of bituminous binders as performance indicators of resistance to permanent deformation of asphalt mixtures because in some cases the conventional criteria for binders do not get reflected in asphalt pavement rutting performance. The aim of this paper is to analyze the zero shear viscosities of bitumen and bitumen-filler mastics with three different levels of limestone filler concentrations on the basis of two viscosity measurement techniques by using a dynamic shear rheometer (DSR). The empirical Cox-Merz rule is used to examine the viscosity correlation between dynamic oscillatory and rotational viscometry measurements. The straight-run 40/60 penetration grade bitumen and limestone bitumen-filler mastics containing low (15%) and intermediate (35%) filler content by mass obey the Cox-Merz rule, whereas the high filler content (65%) mastic shows a divergence in two types of viscosity measurements. The ZSVs of the bitumen and b...

The paper describes the theoretical standpoints of developing magnetoelastic viscometers and a concept of viscosity measurement. The magnetoelastic viscometer has shown the readings close to the capillary viscometer. Testing of the oils with PMMA viscosity-index improvers by viscometers has indicated changes in rheological properties observed in the non-Newtonian behavior of the oils. With increase in content or molecular weight of the improver, the non-Newtonian behavior of the oil appeared at lower frequencies of viscosity measurements.

There are many factors affecting segregation of self-compacting concrete, and one of major factors is aggregate size. Based on the application of Stokes law to analyze aggregate segregation, ball-drop paste viscosity measurement has been used in the research that segregation degree of aggregate of various particle size in paste of identical paste consistency and the relationship between aggregate size and paste viscosity when concrete mixture reach the same fluidity in this article. It shows that aggregate segregation rapidly grows up with the increase of aggregate size and in order to reduce aggregate segregation, paste viscosity should be increased correspondingly under identical fluidity; as the aggregate size comes up to a certain degree, the growth of paste viscosity speeds up obviously, for the sake of maintaining the fluidity, paste should be increased; there is a sudden change in the growth course curve that paste viscosity increases with the aggregate, from the perspective of aggregate segregation, the part before the change has been approved to be a reasonable size range of the aggregate.

Emulsion is normally present in oil due to the mixing occurring during oil recovery. The formation of emulsion can cause some problems in production and transportation. Viscosity and stability of emulsion play a key roles in oil transportation and separation to meet sales specification. Therefore, the aims of this research are to measure the viscosity of oil an emulsion and to evaluate the stability of emulsion of light oil from Fang oilfield in Thailand. The parameters of this study are temperature, shear rate and water cut ranging from 50 to 80 °C, 3.75 to 70 s-1 and 0 to 60%, respectively. These effects of parameters on viscosity and stability of emulsion are required for the design of the process and to increase oil production with various conditions. The results shows that viscosity decreases as temperature and shear rate increase. In contrast, viscosity becomes higher when water cut is lower. Furthermore, droplet sizes of water-in-oil emulsion at different conditions are investigated the stability of emulsion. The droplet sizes become smaller when high shear rate is applied and emulsion becomes more stable. Furthermore, correlations are developed to predict the viscosity and stability of the oil and emulsion from Thailand.

It is known that UV curable resin used in UV nanoimprint shows viscosity change when thin UV-curable resin films are created by spin-coating. Through the study of UV nanoimprint using pentafluoropropane (PFP), which is a promising method enabling high-throughput and reliable UV nanoimprint, it was found that PFP may reduce the viscosity of UV curable resin PAK-01. In this paper, the effect of PFP on the viscosity of spin-coated PAK-01 is carefully studied with our unique viscosity measurement apparatus using an unpatterned mold under the same conditions as in UV nanoimprint where a patterned mold is contacted with spin-coated UV curable resin on a wafer. The effect of viscosity reduction occurs by PFP exposure even for 1s and the effect is not dependent on PFP exposure time. On the other hand, the effect caused by PFP exposure is lost by air exposure for less than 1 s. Namely, the gas, which exists at the moment when a UV curable resin film is making contact with a mold, impacts the viscosity of the UV curable resin regardless of the gas exposure history. We also preliminarily investigated a patterned mold which can trap a larger amount of gas and found that a patterned mold gives the lower viscosity than unpatterned one.

The vibrating fiber partially submerged in fluid has been shown to be an effective device for the viscosity sensing. In this study, small vibrational amplitude of the fiber ( ρ l μ l ) 1/2 and split over the liquid depth. Based on the results a simple way for the viscosity extraction from both the MVA and the bandwidth has been suggested and an explicit formula for the achievable accuracy of the viscosity sensing has been derived. Experiments have confirmed the method of the viscosity extraction.

Modified nanosilica was filled into stereolithography (SL) resin by means of mechanical and ultrasonic dispersion. While the concentration of SiO 2 was below 3 wt%, viscosity measurement showed that the nanoparticles were well dispersed in the resin. Then these modified photosensitive resins were applied to SL prototyping. The results of experiments indicated that, compared with the unmodified resin, the critical exposure of the modified resins increased and their penetration depth decreased. In addition, the mechanical properties of cured specimens increased, and glass transition temperature and the thermal stability of cured specimens were also improved.

Compatibility of the blends of polyamide 6 (PA6) and polyvinylpyrrolidone (PVP) was investigated by solution viscosity measurement, melting point depression and morphological analysis. The viscosity data were discussed by using ΔB and Δb criteria [Formula: see text], where b11 b22 and b12 characterize the interactions between polymer molecules (1-1, 2-2 and 1-2), respectively. ΔB and □b ≥ 0, miscible; ΔB and Δb < 0, immiscible). From melting point data of the PA6 component, the polymer-polymer interaction parameter χ12 = −0.069 was derived through the simplified Nishi-Wang equation. The results revealed that PA6 formed a partially compatible blend with PVP. This conclusion was further evidenced by morphological analysis.

Warm-mix asphalt (WMA) additives are environmentally friendly and cost-effective products that lower the viscosity of bituminous binders to allow reduction of mixing and compaction temperatures in asphalt mix production. In this study, two WMA additives were used; Sasobit® and Advera®. Both were mixed in the lab with unmodified 60/70 Pen and modified PG 76-22 binders. Strain oscillation and viscosity measurement tests were performed to determine the rheological properties of the binder with and without WMA additives. Different ageing processes were performed in this study; half and full short-term ageing using the Rolling Thin Film Oven (RTFO) procedure, and long-term ageing using the Pressurized Ageing Vessel (PAV) procedure. Test results have shown that the addition of Sasobit® increased the stiffness of both binders and changed PG grade by one unit up (6 °C PG grade). Also, Sasobit® presented better rutting resistance in modified and unmodified binders than Advera®, while both WMA additives decreased the fatigue cracking resistance. Multiple Stress Creep Recovery (MSCR) test was also conducted on both unaged and RTFO aged binders. Modified binder with Sasobit® and Advera® exhibited the same performance of the original binder after complete short-term ageing. However, Sasobit® increased the potential of rutting resistance in the unmodified binder more than Advera® did. The viscosity measurements revealed that adding Sasobit® to modified or unmodified binders lowered the viscosity more than Advera® did. These measures were considered as preliminary data required for further studies on the effect of WMA additives on the resistance of bituminous binders to fatigue cracking.

The design and operation of new viscometers are often presented with a focus on the miniaturization of the device and online monitoring of small amounts of liquid samples. The vibrational viscometers commonly used for viscosity measurements exploit the peak value of the frequency-response curve obtained from excitations of the oscillator submerged in the liquid. However, for high-viscosity liquids, the peak of the frequency-response curve is ambiguous or nonexistent, and hence hard to measure. To overcome this drawback and with a view to miniaturizing the device, we use the self-excited oscillations produced by a velocity feedback control. Our design uses a viscometer employing a cantilever driven by a piezo-actuator with analytics that do not rely on the frequency-response curve. A prototype piezo-driven macrocantilever with an oscillating plate attached at its tip was experimentally performed according to specifications. The proposed mechanism can be integrated into microelectromechanical systems (MEMS).

In this work we report the measurement of the viscosity of olive oil at high pressure using a falling sinker type viscometer. The design of the viscometer relies on a close-fitting self-centring sinker enclosed within a vertical tube maintained at a controlled temperature. Based on the accurate fall times of the sinker measured electronically, the performance of the viscometer was studied to provide the relationship of viscosity with pressure for olive oil up to 150 MPa. The viscometer used in this work was shown to provide easily obtained reliable experimental data for correlation with existing relationships of viscosity and pressure.

Cylindrical compression tests were conducted on two different optical glass grades for determining the high-temperature viscosity and elastic parameters. Numerical simulations of the compression tests and the precision lens molding process were performed by incorporating the data obtained from the compression tests using a commercial finite-element method program. Excellent agreement between the viscosity data from the compression test and the beam bending test was obtained, and a good comparison between the measured and predicted deformation load results was also observed. Further issues that have emerged from this research that would be relevant to the ongoing research on the numerical modeling of the precision aspherical lens molding process include determination of high-temperature elastic properties of glass (i.e. elastic and shear modulus) and friction characterization at the glass-mold interface.

The objective of this paper is to show the potential of gas film levitation for noncontact viscosity measurements. Materials studied include oxide and metallic glasses, ceramics, and biphasic metallic alloys. After a brief presentation of the gas film levitator, the analysis procedure of the drop relaxation, both in the aperiodic and oscillating modes, is described in connection with existing hydrodynamic models. The uncertainty of the viscosity measurements ranges from 5 to 15%, depending on the type of materials. The surface tension and the mass density of the sample necessary to derive the viscosity can also be measured in the same experimental apparatus.

The present article describes the generation of copper nanoparticles in the base fluid using developed micro-electrical discharge machining (micro-EDM) process. Micro-EDM was performed with various operating parameters such as voltage, current, pulse width and duty factor. To prevent agglomeration and coagulation of nanoparticles, polyvinyl alcohol (PVA) and polyethylene glycol (PEG) are used as stabilizers. The characterization of the generated copper nanofluid is done by energy dispersive analysis by X-rays, selected area electron diffraction pattern and transmission electron microscope followed by the study of thermal conductivity and viscosity of nanofluid using KD-2 pro device and falling ball type viscometer. The viscosity measurement enables to determine the dispersion stability of copper nanofluids. The experimental results show that the mean size of generated spherical copper nanoparticles is found to be less than 10 nm. It was observed that the thermal conductivity of copper-de-ionized (DI) water, copper-DI water with PVA and PEG nanofluids are 6%, 14% and 15% are higher than that of pure DI water. Also, it was found that there is a reduction of 96% and 99.9% in the sedimentation velocity of copper nanoparticles in copper-DI water with PVA and PEG nanofluid when compared to copper-DI water nanofluid resulting in excellent dispersion stability of the nanoparticles in copper-DI water with PEG nanofluid rather than PVA nanofluid. � 2014 Taylor & Francis Group, LLC.

A sensitive viscometer performing the shear-stress and shear-rate measurement of electrorheological fluid is constructed. This apparatus can measure the absolute value of the low viscosity of pure water as low as with an accuracy of 10% as calibrated from the standard value. The stress - strain relation of electrorheological fluids showing step-wise stick - slip response can clearly be observed from this instrument.

SCC counter which is suitable for somatic cell count (SCC) measurement at individual cow has been developed in our Institute. It consists of metal box with electronics and servomotor. There is a mechanical arm on the front size of it, where a transparent glass tube with running metal ball is placed. SCC counter works on the basis of milk viscosity measurement. After the glass tube is filled with milk mixed with reagent, the tube declines for certain time (20 s) from the horizontal position to the angle of 25°. The metal ball moves downwards and it’s velocity depend on the density of milk. The length of the ball’s path is inverse proportional to the viscosity of the milk. Near the measurement tube the scale is placed, which shows the SCC. Higher viscosity means higher SCC. Three types of equipment were developed. The first has short measurement tube /20 cm/ and it is suitable for quick measurement, when the accuracy is not so important. Second one has longer measurement tube /50 cm/ and is suitable for more precise measurement. The third equipment has four long measurement tubes on the same arm and can measure four samples at once. This type of equipment can be regularly used for measurement of milk from each quarter of the udder. In an experiment we tested the equipment for its accuracy and reliability in practical conditions. Samples of milk were taken from True - test during milking for SCC measurement. Three control ones of the same milk were sent to three different certificated laboratories for SCC analysis. Total two hundred samples have been measured. The average value of SCC from these three laboratories was calculated. The correlation coefficient between SCC from SCC counter and the average value from laboratories was computed (r = 0.96, p

This note is to report on improvements to the slotted-plate device that allows for the determination of viscosity and yield stress in structured systems such as suspensions and electro-rheological fluids. The improvements address the determination of very low yield stress values that occur, for example, with biological fluids, as well as viscosity measurements at extremely low shear rates.

The effect of aggregation on the viscosity was experimentally investigated in the graphite water-based nanofluids. The shear thinning non-Newtonian behavior is observed in the effective viscosity measurement with the shear rate in the nanofluids. On the basis of the best fitting of the experimental data, the viscosities at zero shear rate and at infinite shear rate are determined. As a function of the particle volume concentration and holding period of the nanofluids after preparation, the effective viscosity the increases. The maximum enhancement of the viscosity at infinite rate of shear is over 24 times higher in the 4 vol % 3-day nanofluids compared with the base fluid. A scanning electron microscope was applied to reveal the morphology of aggregated nanoparticles in the nanofluids. The large and irregular aggregation of the particles is found if the nanofluids were kept for three days. Experimental results indicate that the abnormal effective viscosity increase of nanofluids is related to the nanoparticle aggregation in their base fluids.

The aim of this contribution is to present invariance of elongational viscosity measured with respect to a rectangular shape and thickness of LDPE samples using an SER Universal Testing Platform fixed in Anton Paar MCR 501 host system. The width of the samples was changed in the range 2.1–12.7 mm and thickness altered within 0.3÷1 mm. The measurements when a thickness attained 0.1 mm are also presented. There are further compared measurements with and without the clamps.

The paper presents an attempt to find the possibility of measuring high temperature properties of mould powder slags such as viscosity, break temperature, liquidus temperature during heating as well as solidification start and solidification end temperatures during cooing using ultrasonics. These powders are used in continuous casting of steel and the abnormality in their properties can impact the productivity and quality of the steel products. These properties are in general measured by high temperature rotational viscometers, hot stage microscopes and DTA instruments. Here, the fundamental flexural guided wave mode F(1,1) in a ceramic buffer rod was employed in experiments. The results show the possibility of measuring all the above properties in single experiment by measuring ultrasonic reflection factors during continuous heating and cooling of the mould powders. The advantage of the ultrasonic system is that it can be installed in the plant for online monitoring of these properties. The ultrasonically measured properties of the mould powders supplied by five different suppliers were compared with those measured by rotational viscometers and estimated by mathematical models. � 2011.

Nuclear magnetic resonance (NMR) images have been obtained from small-scale samples (multi-laminate and rolled) made from a continuous carbon-fibre reinforced epoxy resin. Empirical relationships may be established between the image intensity observed and the internal viscosity of the polymer phase. Using slice-selective techniques, it is possible to obtain internal images, and hence measure local internal viscosity, non-invasively during the curing process. The results show that NMR imaging may be useful in optimizing both the processing conditions and performance of such materials by enabling the measurement of curing characteristics during manufacture.