Determination of viscosity-average molecular weight of chitosan using intrinsic viscosity measurement

International Nuclear Information System (INIS)

Norzita Yacob; Norhashidah Talip; Maznah Mahmud; Nurul Aizam Idayu Mat Sani; Nor Akma Samsuddin; Norafifah Ahmad Fabillah

2013-01-01

Determination of molecular weight by intrinsic viscosity measurement is a simple method for characterization of chitosan. To study the effect of radiation on molecular weight, chitosan was first irradiated using electron beam at different doses prior to measurement. Different concentrations of chitosan were prepared and measurement was done at room temperature. The flow time data was used to calculate the intrinsic viscosity by extrapolating the reduced viscosity to zero concentration. The value of intrinsic viscosity was then recalculated into the viscosity-average molecular weight using Mark-Houwink equation. (Author)

Molecular mechanism of the viscosity of aqueous glucose solutions

Science.gov (United States)

Bulavin, L. A.; Zabashta, Yu. F.; Khlopov, A. M.; Khorol'skii, A. V.

2017-01-01

Experimental relations are obtained for the viscosity of aqueous glucose solutions in the temperature range of 10-80°C and concentration range 0.01-2.5%. It is found that the concentration dependence of fluidity is linear when the concentration is higher than a certain value and varies at different temperatures. The existence of such a dependence indicates that the mobilities of solvent and solute molecules are independent of the concentration of solutions. This assumption is used to construct a theoretical model, in which the structure of an aqueous glucose solution is presented as a combination of two weakly interacting networks formed by hydrogen bonds between water molecules and between glucose molecules. Theoretical relations are obtained using this model of network solution structure for the concentration and temperature dependence of solution viscosity. Experimental data are used to calculate the activation energies for water ( U w = 3.0 × 10-20 J) and glucose molecules ( U g = 2.8 × 10-20 J). It is shown that the viscosity of a solution in such a network structure is governed by the Brownian motion of solitons along the chains of hydrogen bonds. The weak interaction between networks results in the contributions to solution fluidity made by the motion of solitons in both of them being almost independent.

Effect of gamma irradiation on viscosity of aqueous solutions of some natural polymers

International Nuclear Information System (INIS)

Nguyen Tan Man; Truong Thi Hanh; Le Quang Luan; Le Hai; Nguyen Quoc Hien

2000-01-01

Effect of gamma irradiation on viscosity of aqueous solution of alginate and carbon xylmethyl cellulose (CMC) irradiated in solid state has been carried out. the viscosity of aqueous solution of alginate and CMC decreased remarkably with increasing dose and the viscosity of 2% solution of above polymers irradiated at 50 kGy was about 100 times lower than the original one. (author)

Reduced viscosity for flagella moving in a solution of long polymer chains

Science.gov (United States)

Zhang, Yuchen; Li, Gaojin; Ardekani, Arezoo M.

2018-02-01

The bacterial flagellum thickness is smaller than the radius of gyration of long polymer chain molecules. The flow velocity gradient over the length of polymer chains can be nonuniform and continuum models of polymeric liquids break in this limit. In this work, we use Brownian dynamics simulations to study a rotating helical flagellum in a polymer solution and overcome this limitation. As the polymer size increases, the viscosity experienced by the flagellum asymptotically reduces to the solvent viscosity. The contribution of polymer molecules to the local viscosity in a solution of long polymer chains decreases with the inverse of polymer size to the power 1/2. The difference in viscosity experienced by the bacterial cell body and flagella can predict the nonmonotonic swimming speed of bacteria in polymer solutions.

Microcantilever based disposable viscosity sensor for serum and blood plasma measurements.

Science.gov (United States)

Cakmak, Onur; Elbuken, Caglar; Ermek, Erhan; Mostafazadeh, Aref; Baris, Ibrahim; Erdem Alaca, B; Kavakli, Ibrahim Halil; Urey, Hakan

2013-10-01

This paper proposes a novel method for measuring blood plasma and serum viscosity with a microcantilever-based MEMS sensor. MEMS cantilevers are made of electroplated nickel and actuated remotely with magnetic field using an electro-coil. Real-time monitoring of cantilever resonant frequency is performed remotely using diffraction gratings fabricated at the tip of the dynamic cantilevers. Only few nanometer cantilever deflection is sufficient due to interferometric sensitivity of the readout. The resonant frequency of the cantilever is tracked with a phase lock loop (PLL) control circuit. The viscosities of liquid samples are obtained through the measurement of the cantilever's frequency change with respect to a reference measurement taken within a liquid of known viscosity. We performed measurements with glycerol solutions at different temperatures and validated the repeatability of the system by comparing with a reference commercial viscometer. Experimental results are compared with the theoretical predictions based on Sader's theory and agreed reasonably well. Afterwards viscosities of different Fetal Bovine Serum and Bovine Serum Albumin mixtures are measured both at 23°C and 37°C, body temperature. Finally the viscosities of human blood plasma samples taken from healthy donors are measured. The proposed method is capable of measuring viscosities from 0.86 cP to 3.02 cP, which covers human blood plasma viscosity range, with a resolution better than 0.04 cP. The sample volume requirement is less than 150 μl and can be reduced significantly with optimized cartridge design. Both the actuation and sensing are carried out remotely, which allows for disposable sensor cartridges. Copyright © 2013. Published by Elsevier Inc.

Viscosity solutions of fully nonlinear functional parabolic PDE

Directory of Open Access Journals (Sweden)

Liu Wei-an

2005-01-01

Full Text Available By the technique of coupled solutions, the notion of viscosity solutions is extended to fully nonlinear retarded parabolic equations. Such equations involve many models arising from optimal control theory, economy and finance, biology, and so forth. The comparison principle is shown. Then the existence and uniqueness are established by the fixed point theory.

Automation of a high-speed imaging setup for differential viscosity measurements

Science.gov (United States)

Hurth, C.; Duane, B.; Whitfield, D.; Smith, S.; Nordquist, A.; Zenhausern, F.

2013-12-01

We present the automation of a setup previously used to assess the viscosity of pleural effusion samples and discriminate between transudates and exudates, an important first step in clinical diagnostics. The presented automation includes the design, testing, and characterization of a vacuum-actuated loading station that handles the 2 mm glass spheres used as sensors, as well as the engineering of electronic Printed Circuit Board (PCB) incorporating a microcontroller and their synchronization with a commercial high-speed camera operating at 10 000 fps. The hereby work therefore focuses on the instrumentation-related automation efforts as the general method and clinical application have been reported earlier [Hurth et al., J. Appl. Phys. 110, 034701 (2011)]. In addition, we validate the performance of the automated setup with the calibration for viscosity measurements using water/glycerol standard solutions and the determination of the viscosity of an "unknown" solution of hydroxyethyl cellulose.

Automation of a high-speed imaging setup for differential viscosity measurements

Energy Technology Data Exchange (ETDEWEB)

Hurth, C.; Duane, B.; Whitfield, D.; Smith, S.; Nordquist, A.; Zenhausern, F. [Center for Applied Nanobioscience and Medicine, The University of Arizona College of Medicine, 425 N 5th Street, Phoenix, Arizona 85004 (United States)

2013-12-28

We present the automation of a setup previously used to assess the viscosity of pleural effusion samples and discriminate between transudates and exudates, an important first step in clinical diagnostics. The presented automation includes the design, testing, and characterization of a vacuum-actuated loading station that handles the 2 mm glass spheres used as sensors, as well as the engineering of electronic Printed Circuit Board (PCB) incorporating a microcontroller and their synchronization with a commercial high-speed camera operating at 10 000 fps. The hereby work therefore focuses on the instrumentation-related automation efforts as the general method and clinical application have been reported earlier [Hurth et al., J. Appl. Phys. 110, 034701 (2011)]. In addition, we validate the performance of the automated setup with the calibration for viscosity measurements using water/glycerol standard solutions and the determination of the viscosity of an “unknown” solution of hydroxyethyl cellulose.

Continuous dependence estimates for viscosity solutions of fully nonlinear degenerate elliptic equations

Directory of Open Access Journals (Sweden)

Espen R. Jakobsen

2002-05-01

Full Text Available Using the maximum principle for semicontinuous functions [3,4], we prove a general ``continuous dependence on the nonlinearities'' estimate for bounded Holder continuous viscosity solutions of fully nonlinear degenerate elliptic equations. Furthermore, we provide existence, uniqueness, and Holder continuity results for bounded viscosity solutions of such equations. Our results are general enough to encompass Hamilton-Jacobi-Bellman-Isaacs's equations of zero-sum, two-player stochastic differential games. An immediate consequence of the results obtained herein is a rate of convergence for the vanishing viscosity method for fully nonlinear degenerate elliptic equations.

Viscosity of high concentration protein formulations of monoclonal antibodies of the IgG1 and IgG4 subclass - Prediction of viscosity through protein-protein interaction measurements

DEFF Research Database (Denmark)

Neergaard, Martin S; Kalonia, Devendra S; Parshad, Henrik

2013-01-01

The purpose of this work was to explore the relation between protein-protein interactions (PPIs) and solution viscosity at high protein concentration using three monoclonal antibodies (mAbs), two of the IgG4 subclass and one of the IgG1 subclass. A range of methods was used to quantify the PPI...... low or high protein concentration determined using DLS. The PPI measurements were correlated with solution viscosity (measured by DLS using polystyrene nanospheres and ultrasonic shear rheology) as a function of pH (4-9) and ionic strength (10, 50 and 150mM). Our measurements showed that the highest...... solution viscosity was observed under conditions with the most negative kD, the highest apparent radius and the lowest net charge. An increase in ionic strength resulted in a change in the nature of the PPI at low pH from repulsive to attractive. In the neutral to alkaline pH region the mAbs behaved...

From Suitable Weak Solutions to Entropy Viscosity

KAUST Repository

Guermond, Jean-Luc

2010-12-16

This paper focuses on the notion of suitable weak solutions for the three-dimensional incompressible Navier-Stokes equations and discusses the relevance of this notion to Computational Fluid Dynamics. The purpose of the paper is twofold (i) to recall basic mathematical properties of the three-dimensional incompressible Navier-Stokes equations and to show how they might relate to LES (ii) to introduce an entropy viscosity technique based on the notion of suitable weak solution and to illustrate numerically this concept. © 2010 Springer Science+Business Media, LLC.

Conditions of viscosity measurement for detecting irradiated peppers

International Nuclear Information System (INIS)

Hayashi, Toru; Todoriki, Setsuko; Okadome, Hiroshi; Kohyama, Kaoru

1995-01-01

Viscosity of gelatinized suspensions of black and white peppers decreased depending upon dose. The viscosity was influenced by gelatinization and viscosity measurement conditions. The difference between unirradiated pepper and an irradiated one was larger at a higher pH and temperature for gelatinization. A viscosity parameter normalized with the starch content of pepper sample and the viscosity of a 5% suspension of corn starch could get rid of the influence of the conditions for viscosity measurement such as type of viscometer, shear rate and temperature. (author)

Viscosity measurement techniques in Dissipative Particle Dynamics

Science.gov (United States)

Boromand, Arman; Jamali, Safa; Maia, Joao M.

2015-11-01

In this study two main groups of viscosity measurement techniques are used to measure the viscosity of a simple fluid using Dissipative Particle Dynamics, DPD. In the first method, a microscopic definition of the pressure tensor is used in equilibrium and out of equilibrium to measure the zero-shear viscosity and shear viscosity, respectively. In the second method, a periodic Poiseuille flow and start-up transient shear flow is used and the shear viscosity is obtained from the velocity profiles by a numerical fitting procedure. Using the standard Lees-Edward boundary condition for DPD will result in incorrect velocity profiles at high values of the dissipative parameter. Although this issue was partially addressed in Chatterjee (2007), in this work we present further modifications (Lagrangian approach) to the original LE boundary condition (Eulerian approach) that will fix the deviation from the desired shear rate at high values of the dissipative parameter and decrease the noise to signal ratios in stress measurement while increases the accessible low shear rate window. Also, the thermostat effect of the dissipative and random forces is coupled to the dynamic response of the system and affects the transport properties like the viscosity and diffusion coefficient. We investigated thoroughly the dependency of viscosity measured by both Eulerian and Lagrangian methodologies, as well as numerical fitting procedures and found that all the methods are in quantitative agreement.

On the measurement of magnetic viscosity

Energy Technology Data Exchange (ETDEWEB)

Serletis, C. [Department of Physics, Aristotle University, Thessaloniki 54124 (Greece); Efthimiadis, K.G., E-mail: kge@auth.gr [Department of Physics, Aristotle University, Thessaloniki 54124 (Greece)

2012-08-15

This work is an investigation of the experimental method used for measuring the magnetic viscosity in a hard ferromagnetic material, i.e. the recording of the magnetization under constant applied field and temperature, after the material has been magnetically saturated. It investigates how the experimental results are affected by the initial conditions of the method (saturation field, field change rate and field oscillation prior to its stabilization), and by minor variations of field and temperature during the recording. Based on the arising conclusions and the use of a more complex fitting function of measurements, the accuracy and repeatability of experimental results is improved. - Highlights: Black-Right-Pointing-Pointer Magnetic viscosity is affected by initial measurement conditions. Black-Right-Pointing-Pointer Minor field deviations prior to its stabilization cause large changes in viscosity. Black-Right-Pointing-Pointer Viscosity is strongly dependent on the field change rate from saturation to the measurement field. Black-Right-Pointing-Pointer Small changes in field and temperature during the experiment can lead to false measurements. Black-Right-Pointing-Pointer Errors in measurements can be eliminated through the use of a proper fitting function.

Measurement and COrrelation on Viscosity and Apparent Molar Volume of Ternary System for L—ascorbic Acid in Aqueous D—Glucose and Sucrose Solutions

Institute of Scientific and Technical Information of China (English)

赵长伟; 马沛生

2003-01-01

Visosities and densities at ,several temperatures from 293.15 K to 313.15K are reported for L-ascorbic acid in aqueous glucose and sucrose solutions at different concentrations.The parameters of density,Viscosity coefficient B and partial molar volume are calculated by regression.The experimental results show that densities and viscositis decrease as temperature increases at the same solute and solvent (glucose and sucrose aueous solution)concentrations,and increase with concentration of glucose and sucrose at the same solute concentration and temperature,B increases with concentration of glucose and sucrose and temaperature,L-ascorbic acid is sturcture-breaker or structure-making for the glucose and sucrose aqueous solutions ,Furthermore,the solute-solvent interactions in ternary systems of water-glucose-electrolyte and water-sucrose-electrolyte are discussed.

Effect of gamma irradiation in the viscosity of gelatin and pectin solutions used in food industry

International Nuclear Information System (INIS)

Inamura, Patricia Yoko

2008-01-01

Pectin is a polysaccharide substance of plant origin that may be used as gelling agent, stabilizer in jams, in yogurt drinks and lactic acid beverages. Gelatin, a protein from bovine origin, in this case, is mainly used as gelling agent due to hydrogel formation during cooling. The 60 Co-irradiation process may cause various modifications in macromolecules, some with industrial application, as reticulation. The dynamic response of viscoelastic materials can be used in order to give information about the structural aspect of a system at molecular level. In the present work samples of pectin with different degree of methoxylation, gelatin and the mixture of both were employed to study the radiation sensitivity by means of viscosity measurements. Solutions prepared with citric pectin with high methoxylation content (ATM) 1 por cent, pectin with low content (BTM) 1 por cent, gelatin 0.5 por cent, 1 por cent and 2 por cent, and the mixture 1 por cent and 2 por cent were irradiated with gamma rays at different doses, up to 15 kGy with dose rate about 2 kGy/h. After irradiation the viscosity was measured within a period of 48 h. The viscosity of ATM and BTM pectin solutions decreased sharply with the radiation dose. However, the gelatin sample presented a great radiation resistance. When pectin and gelatin solutions were mixed a predominance of pectin behavior was found. (author)

The Asymptotic Solution for the Steady Variable-Viscosity Free ...

African Journals Online (AJOL)

Under an arbitrary time-dependent heating of an infinite vertical plate (or wall), the steady viscosity-dependent free convection flow of a viscous incompressible fluid is investigated. Using the asymptotic method of solution on the governing equations of motion and energy, the resulting Ordinary differential equations were ...

Rapid viscosity measurements of powdered thermosetting resins

Science.gov (United States)

Price, H. L.; Burks, H. D.; Dalal, S. K.

1978-01-01

A rapid and inexpensive method of obtaining processing-related data on powdered thermosetting resins has been investigated. The method involved viscosity measurements obtained with a small specimen (less than 100 mg) parallel plate plastometer. A data acquisition and reduction system was developed which provided a value of viscosity and strain rate about 12-13 second intervals during a test. The effects of specimen compaction pressure and reduction of adhesion between specimen and parallel plates were examined. The plastometer was used to measure some processing-related viscosity changes of an addition polyimide resin, including changes caused by pre-test heat treatment, test temperature, and strain rate.

Sensor for Viscosity and Shear Strength Measurement

International Nuclear Information System (INIS)

Dillon, J.; Moore, J.E. Jr.; Ebadian, M.A.; Jones, W.K.

1998-01-01

Measurement of the physical properties (viscosity and density) of waste slurries is critical in evaluating transport parameters to ensure turbulent flow through transport pipes. The environment for measurement and sensor exposure is extremely harsh; therefore, reliability and ruggedness are critical in the sensor design. The work for this project will be performed in three phases. The first phase, carried out in FY96, involved (1) an evaluation of acoustic and other methods for viscosity measurement; (2) measurement of the parameters of slurries over the range of percent solids found in tanks and transport systems; (3) a comparison of physical properties (e.g., viscosity and density) to percent solids found composition; and (4) the design of a prototype sensor. The second phase (FY97) will involve the fabrication of a prototype hybrid sensor to measure the viscosity and mechanical properties of slurries in remote, high-radiation environments. Two different viscometer designs are being investigated in this study: a magnetostrictive pulse wave guide viscometer; an oscillating cylinder viscometer. In FY97, the Hemispheric Center for Environmental Technology (HCET) at Florida International University (FIU), which has printed circuit, thick film, thin film, and co-fired ceramic fabrication capability, will fabricate five probes for demonstration after technology selection and evaluation

Densities, refractive indices, and viscosities of N,N-diethylethanol ammonium chloride–glycerol or –ethylene glycol deep eutectic solvents and their aqueous solutions

International Nuclear Information System (INIS)

Siongco, Kathrina R.; Leron, Rhoda B.; Li, Meng-Hui

2013-01-01

Highlights: • The densities, refractive indices, and viscosities of aqueous DES solutions were measured. • DES are made from N,N-diethylethanol ammonium chloride + glycerol or ethylene glycol. • The temperature studied was (298.15 to 343.15) K. • The measured data were reported as functions of temperature and composition. • The measured data were represented satisfactorily by the applied correlations. -- Abstract: In this work, we report new experimental data on density, ρ, refractive index, n D, and viscosity, η, of two deep eutectic solvents, N,N-diethylethanol ammonium chloride–glycerol (DEACG) and N,N-diethylethanol ammonium chloride–ethylene glycol (DEACEG), and their aqueous solutions, over the complete composition range, at temperatures from (298.15 to 343.15) K. Densities and viscosities were measured using the vibrating tube and the falling ball techniques, respectively, while the refractive index at the sodium D line was measured using an automatic refractometer. We aimed to represent the measured properties as a function of temperature and composition, and correlated them using the Redlich–Kister-type equation, for density, a polynomial function, for refractive index, and the Vogel–Fulcher–Tammann (VFT) equation, for viscosity

Density, viscosity, and N2O solubility of aqueous amino acid salt and amine amino acid salt solutions

International Nuclear Information System (INIS)

Aronu, Ugochukwu E.; Hartono, Ardi; Svendsen, Hallvard F.

2012-01-01

Highlights: ► Density of amino acid salt and amine amino acid salt. ► Viscosity of amino acid salt and amine amino acid salt. ► Henry’s law constant/N 2 O solubility of amino acid salt and amine amino acid salt. ► Schumpe model. Correlations for density, viscosity, and N 2 O solubility. - Abstract: Physicochemical properties of aqueous amino acid salt (AAS), potassium salt of sarcosine (KSAR) and aqueous amine amino acid salt (AAAS), 3-(methylamino)propylamine/sarcosine (SARMAPA) have been studied. Densities of KSAR were measured for sarcosine mole fraction 0.02 to 0.25 for temperature range 298.15 K to 353.15 K, the viscosities were measured for 0.02 to 0.10 mole fraction sarcosine (293.15 K to 343.15 K) while the N 2 O solubilities were measured from 0.02 to 0.10 mole fraction sarcosine solutions (298.15 K to 363.15 K). Densities of SARMAPA were measured for sarcosine mole fraction 0.02 to 0.23 for temperature range (298.15 K to 353.15 K), viscosities were measured for 0.02 to 0.16 mole fraction sarcosine (293.15 K to 343.15 K) while the N 2 O solubilities were measured from 0.02 to 0.16 mole fraction sarcosine solutions (298.15 K to 343.15 K). Experimental results were correlated well with empirical correlations and N 2 O solubility results for KSAR were predicted adequately by a Schumpe model. The solubilities of N 2 O in AAS and AAAS are significantly lower than values for amines. The solubilities vary as: amine > AAAS > AAS.

Viscosity of aqueous Ni(NO3)2 solutions at temperatures from (297 to 475) K and at pressures up to 30 MPa and concentration between (0.050 and 2.246) mol . kg-1

International Nuclear Information System (INIS)

Abdulagatov, I.M.; Zeinalova, A.B.; Azizov, N.D.

2006-01-01

Viscosity of nine aqueous Ni(NO 3 ) 2 solutions (0.050, 0.153, 0.218, 0.288, 0.608, 0.951, 1.368, 1.824, and 2.246) mol . kg -1 was measured in the temperature range from (297 to 475) K and at pressures (0.1, 10, 20, and 30) MPa. The measurements were carried out with a capillary flow technique. The total experimental uncertainty of viscosity, pressure, temperature, and composition measurements were estimated to be less than 1.6%, 0.05%, 15 mK, and 0.02%, respectively. All experimental and derived results are compared with experimental and calculated values reported in the literature. Extrapolation of the solution viscosity measurements to zero concentration (pure water values) for the given temperature and pressure are in excellent agreement (average absolute deviation, AAD = 0.13%) with the values of pure water viscosity from IAPWS formulation [J. Kestin, J.V. Sengers, B. Kamgar-Parsi, J.M.H. Levelt Sengers, J. Phys. Chem. Ref. Data 13 (1984) 175-189]. The viscosity data for the solutions as a function of concentration have been interpreted in terms of the extended Jones-Dole equation for strong electrolytes. The values of viscosity A-, B-, and D-coefficients of the extended Jones-Dole equation for the relative viscosity (η/η ) of aqueous Ni(NO 3 ) 2 solutions as a function of temperature are studied. The derived values of the viscosity A- and B-coefficients were compared with the results predicted by Falkenhagen-Dole theory (limiting law) of electrolyte solutions and the values calculated with the ionic B-coefficient data. The measured values of viscosity for the solutions were also used to calculate the effective rigid molar volumes in the extended Einstein relation for the relative viscosity (η/η )

Measuring Viscosities of Gases at Atmospheric Pressure

Science.gov (United States)

Singh, Jag J.; Mall, Gerald H.; Hoshang, Chegini

1987-01-01

Variant of general capillary method for measuring viscosities of unknown gases based on use of thermal mass-flowmeter section for direct measurement of pressure drops. In technique, flowmeter serves dual role, providing data for determining volume flow rates and serving as well-characterized capillary-tube section for measurement of differential pressures across it. New method simple, sensitive, and adaptable for absolute or relative viscosity measurements of low-pressure gases. Suited for very complex hydrocarbon mixtures where limitations of classical theory and compositional errors make theoretical calculations less reliable.

Viscosity of aluminum under shock-loading conditions

International Nuclear Information System (INIS)

Ma Xiao-Juan; Liu Fu-Sheng; Zhang Ming-Jian; Sun Yan-Yun

2011-01-01

A reliable data treatment method is critical for viscosity measurements using the disturbance amplitude damping method of shock waves. In this paper the finite difference method is used to obtain the numerical solutions for the disturbance amplitude damping behaviour of the sinusoidal shock front in a flyer-impact experiment. The disturbance amplitude damping curves are used to depict the numerical solutions of viscous flow. By fitting the experimental data to the numerical solutions of different viscosities, we find that the effective shear viscosity coefficients of shocked aluminum at pressures of 42, 78 and 101 GPa are (1500±100) Pa·s, (2800±100) Pa·s and (3500±100) Pa·s respectively. It is clear that the shear viscosity of aluminum increases with an increase in shock pressure, so aluminum does not melt below a shock pressure of 101 GPa. This conclusion is consistent with the sound velocity measurement. (interdisciplinary physics and related areas of science and technology)

Intrinsic viscosity of guar gum in sweeteners solutions | Samavati ...

African Journals Online (AJOL)

Rheological methods were applied to study the effect of sweeteners on the rheological behavior of guar gum in dilute solutions. The concentration of the sweeteners were 0.1, 0.2%w/v for aspartame, acesulfame-k and cyclamate, and 0.001, 0.002%w/v for neotame. Gum was evaluated for intrinsic viscosity by various ...

Hierarchical viscosity of aqueous solution of tilapia scale collagen investigated via dielectric spectroscopy between 500 MHz and 2.5 THz

Science.gov (United States)

Kawamata, H.; Kuwaki, S.; Mishina, T.; Ikoma, T.; Tanaka, J.; Nozaki, R.

2017-03-01

Aqueous solutions of biomolecules such as proteins are very important model systems for understanding the functions of biomolecules in actual life processes because interactions between biomolecules and the surrounding water molecules are considered to be important determinants of biomolecules’ functions. Globule proteins have been extensively studied via dielectric spectroscopy; the results indicate three relaxation processes originating from fluctuations in the protein molecule, the bound water and the bulk water. However, the characteristics of aqueous solutions of collagens have rarely been investigated. In this work, based on broadband dielectric measurements between 500 MHz and 2.5 THz, we demonstrate that the high viscosity of a collagen aqueous solution is due to the network structure being constructed of rod-like collagen molecules surrounding free water molecules and that the water molecules are not responsible for the viscosity. We determine that the macroscopic viscosity is related to the mean lifetime of the collagen-collagen interactions supporting the networks and that the local viscosity of the water surrounded by the networks is governed by the viscosity of free water as in the bulk. This hierarchical structure in the dynamics of the aqueous solution of biomolecules has been revealed for the first time.

Viscosity of crystalline proteins in solution, when irradiated with 60 Co

International Nuclear Information System (INIS)

Bernardes, D.M.L.; Mastro, N.L. del

1992-01-01

In order to study 60 Co radiation effects on proteins, an aqueous solution of bovine crystalline was irradiated with doses from O to 25,000 Gy. Changes in viscosity were followed whether in the presence or absence of radiation response modifiers: glutathione (GSH), amino ethyl isothiourea (AET), mercapto ethyl alanine (MEA) e dimethyl sulfoxide (DMSO). Viscosity data at different temperature revealed that aggregate formation was the predominant process induced by radiation. The results showed also that in presence of those substances the radiation effects was diminished. (author)

Effects of solution viscosity on heterogeneous electron transfer across a liquid/liquid interface

Energy Technology Data Exchange (ETDEWEB)

Bai Yamin; Sun Peng; Zhang Meiqin; Gao Zhao; Yang Zhengyu; Shao Yuanhua

2003-10-15

Scanning electrochemical microscopy (SECM) is employed to investigate the effect of solution viscosity on the rate constants of electron transfer (ET) reaction between potassium ferricyanide in water and 7,7,8,8-tetracyanoquinodimethane (TCNQ) in 1,2-dichloroethane. Either tetrabutylammonium (TBA{sup +}) or ClO{sub 4}{sup -} is chosen as the common ion in both phases to control the interfacial potential drop. The rate constant of heterogeneous ET reaction between TCNQ and ferrocyanide produced in-situ, k{sub 12}, is evaluated by SECM and is inversely proportional to the viscosity of the aqueous solution and directly proportional to the diffusion coefficient of K{sub 4}Fe(CN){sub 6} in water when the concentration of TCNQ in the DCE phase is in excess. The k{sub 12} dependence on viscosity is explained in terms of the longitudinal relaxation time of the solution. The rate constant of the heterogeneous ET reaction between TCNQ{sup -} and ferricyanide, k{sub 21}, is also obtained by SECM and these results cannot be explained by the same manner.

A different interpretation of Einstein's viscosity equation provides accurate representations of the behavior of hydrophilic solutes to high concentrations.

Science.gov (United States)

Zavitsas, Andreas A

2012-08-23

Viscosities of aqueous solutions of many highly soluble hydrophilic solutes with hydroxyl and amino groups are examined with a focus on improving the concentration range over which Einstein's relationship between solution viscosity and solute volume, V, is applicable accurately. V is the hydrodynamic effective volume of the solute, including any water strongly bound to it and acting as a single entity with it. The widespread practice is to relate the relative viscosity of solute to solvent, η/η(0), to V/V(tot), where V(tot) is the total volume of the solution. For solutions that are not infinitely dilute, it is shown that the volume ratio must be expressed as V/V(0), where V(0) = V(tot) - V. V(0) is the volume of water not bound to the solute, the "free" water solvent. At infinite dilution, V/V(0) = V/V(tot). For the solutions examined, the proportionality constant between the relative viscosity and volume ratio is shown to be 2.9, rather than the 2.5 commonly used. To understand the phenomena relating to viscosity, the hydrodynamic effective volume of water is important. It is estimated to be between 54 and 85 cm(3). With the above interpretations of Einstein's equation, which are consistent with his stated reasoning, the relation between the viscosity and volume ratio remains accurate to much higher concentrations than those attainable with any of the other relations examined that express the volume ratio as V/V(tot).

Separate measurement of the density and viscosity of a liquid using a quartz crystal microbalance based on admittance analysis (QCM-A)

International Nuclear Information System (INIS)

Itoh, Atsushi; Ichihashi, Motoko

2011-01-01

We previously used a quartz crystal microbalance (QCM) to identify a frequency f 2 that allows measurement of the mass load without being affected by the viscous load of a liquid in the liquid phase. Here, we determined that frequency in order to separately measure the density and viscosity of a Newtonian liquid. Martin et al separately measured the density and viscosity of a liquid by immersing two quartz resonators, i.e. a smooth-surface resonator and a textured-surface resonator, in the liquid. We used a QCM based on admittance analysis (QCM-A) in the current study to separately measure the viscosity and density of a liquid using only a textured-surface resonator. In the current experiments, we measured the density and viscosity of 500 µl of 10%, 30%, and 50% aqueous glycerol solutions and compared the measured values to reference values. The density obtained had an error of ±1.5% of reference values and the viscosity had an error of about ±5% of reference values. Similar results were obtained with 500 µl of 10%, 30%, and 50% ethanol solutions. Measurement was possible with a quartz resonator, so measurements were made with even smaller samples. The density and viscosity of a liquid were successfully determined with an extremely small amount of liquid, i.e. 10 µl, with almost the same precision as when using 500 µl of the liquid

Applicability of viscosity measurement to the detection of irradiated peppers

International Nuclear Information System (INIS)

Hayashi, T.; Todoriki, S.; Kohyama, K.

1996-01-01

Starch is degraded by ionising radiation, resulting in a decrease in viscosity. The viscosities of black and white peppers which contain large amounts of starch are reduced by irradiation so, therefore, viscosity measurement has been proposed as a method to detect the irradiation treatment of these food products. Although detection of irradiated spices by thermoluminescence measurement has been established, it is useful to establish the viscosity measuring technique for detecting irradiated peppers, as this method is carried out widely in the laboratories of food controlling authorities and food processing companies. (author)

Ultrasonic speed, densities and viscosities of xylitol in water and in aqueous tyrosine and phenylalanine solutions at different temperatures

Science.gov (United States)

Ali, A.; Bidhuri, P.; Uzair, S.

2014-07-01

Ultrasonic speed u, densities ρ and viscosities η of xylitol in water and in 0.001 m aqueous l-tyrosine (Tyr) and l-phenylalanine (Phe) have been measured at different temperatures. From the density and ultrasonic speed measurements apparent molar isentropic compression κ_{φ}, apparent molar isentropic compressions at infinite dilution κ_{{S,φ}}0 , experimental slope S K , hydration number n H , transfer partial molar isentropic compressibility Δ_{tr} κ_{{S,φ}}0 of xylitol from water to aqueous Tyr and Phe have been obtained. From the viscosity data, B-coefficient and B-coefficient of transfer Δ tr B of xylitol from water to aqueous Phe and Tyr at different temperatures have also been estimated. Gibbs free energies of activation of viscous flow per mole of solvent Δ μ 1 0# and per mole of solute Δ μ 2 0# have been calculated by using Feakins transition state theory for the studied systems. The calculated parameters have been interpreted in terms of solute-solute and solute-solvent interactions and hydration behavior of xylitol.

Drifting solutions with elliptic symmetry for the compressible Navier-Stokes equations with density-dependent viscosity

International Nuclear Information System (INIS)

An, Hongli; Yuen, Manwai

2014-01-01

In this paper, we investigate the analytical solutions of the compressible Navier-Stokes equations with dependent-density viscosity. By using the characteristic method, we successfully obtain a class of drifting solutions with elliptic symmetry for the Navier-Stokes model wherein the velocity components are governed by a generalized Emden dynamical system. In particular, when the viscosity variables are taken the same as Yuen [M. W. Yuen, “Analytical solutions to the Navier-Stokes equations,” J. Math. Phys. 49, 113102 (2008)], our solutions constitute a generalization of that obtained by Yuen. Interestingly, numerical simulations show that the analytical solutions can be used to explain the drifting phenomena of the propagation wave like Tsunamis in oceans

Density, thermal expansion coefficient and viscosity of sodium tetraborate (borax)-UO2 and of sodium metaborate-UO2 solutions at high temperatures

International Nuclear Information System (INIS)

Dalle Donne, M.; Dorner, S.; Roth, A.

1983-01-01

Measurements have been performed of the density, of the volumetric thermal expansion coefficient and of the viscosity of liquid sodium tetraborate (borax) and of sodium metaborate both pure and with two different amounts of UO 2 dissolved in each. The viscosity measurements have been performed for the solution of sodium tetraborate with UO 2 and CeO 2 , and with CeO 2 only as well. These data are required for the design of core-catchers based on sodium borates. The density measurements have been performed with the buoyancy method in the temperature range from 825 0 C to 1300 0 C, the viscosity measurements in the temperature range 700-1250 0 C with a modified Haake viscosity balance. The balance was previously calibrated at ambient temperature with a standard calibration liquid and at high temperatures, with data for pure borax available from the literature. (orig.)

Thermodynamic study of three pharmacologically significant drugs: Density, viscosity, and refractive index measurements at different temperatures

International Nuclear Information System (INIS)

Iqbal, Muhammad Javed; Chaudhry, Mansoora Ahmed

2009-01-01

Measurements of density, viscosity, and refractive index of three pharmacologically significant drugs, i.e. diclofenac sodium, cetrizine, and doxycycline have been carried in aqueous medium at T = (293.15 to 313.15) K. An automated vibrating-tube densimeter, viscometer, and refractometer are used in a concentration range from (7.5) . 10 -3 to 25 . 10 -3 ) mol . kg -1 . The precise density results are used to evaluate the apparent molar volume, partial molar volume, thermal expansion coefficient, partial molar expansivity, and the Hepler's constant. Viscosity results are used to calculate the Jones-Dole viscosity B-coefficient, free energy of activation of the solute and solvent, activation enthalpy, and activation entropy. The molar refractive indices of the drug solutions can be employed to calculate molar refraction. It is inferred from these results that the above mentioned drugs act as structure-making compounds due to hydrophobic hydration of the molecules in the drugs

Online shear viscosity measurement of starchy melts enriched in wheat bran.

Science.gov (United States)

Robin, Frédéric; Bovet, Nicolas; Pineau, Nicolas; Schuchmann, Heike P; Palzer, Stefan

2011-01-01

Addition of wheat bran to flours modifies their expansion properties after cooking extrusion. This can be attributed to changes in the melt shear viscosity at the die. The effect of wheat bran concentration added to achieve 2 levels of dietary fibers of 12. 6% and 24.4%, and process conditions on the shear viscosity of wheat flour was therefore assessed using an online twin-slit rheometer. The shear viscosity measured at 30 s⁻¹ ranged from 9.5 × 10³ to 53.4 × 10³ Pa s. Regardless of the process conditions and bran concentration, the extruded melts showed a pseudoplastic behavior with a power law index n ranging from 0.05 to 0.27. Increasing the barrel temperature of the extruder from 120 to 180 °C, the water content from 18% to 22% or the screw speed from 400 to 800 rpm significantly decreased the melt shear viscosity at the extruder exit. The addition of bran significantly increased the melt shear viscosity only at the highest bran concentration. The effect was process condition dependant. Mathematical interpretations, based upon observations, of the experimental data were carried out. They can be used to predict the effect of the process conditions on the melt shear viscosity at the die of extruded wheat flour with increasing bran concentration. The viscosity data will be applied in future works to study the expansion properties of extruded wheat flour supplemented with bran. Incorporation of wheat bran, a readily available and low cost by-product, in extruded puffed foods is constrained due to its negative effect on the product texture. Understanding the effect of wheat bran on rheological properties of extruded melts, driving the final product properties, is essential to provide solutions to the food industry and enhance its use. © 2011 Institute of Food Technologists®

Measurement of viscosity of slush at high shear rates

OpenAIRE

小林, 俊一; 川村, 公之; 津川, 圭一; 和泉, 薫; Kobayashi, Shun'ichi; Kawamura, Kimiyuki; Tugawa, Keiichi; Izumi, Kaoru

1988-01-01

Measurements of viscosity of slush were carried out using a method of flow along an inclined smooth surface in a 0℃cold room. The method was used to get the values of viscosity under high shear rates (25 and 75s^). From our experiments two important results were obtained: 1) the viscosity of slush decreases with increasing shear rates; 2) The fluid behavior is pseudoplastic that the values of non-Newtonian index of viscosity were less than unity.

Resistor capacitor, primitive variable solution of buoyant fluid flow within an enclosure with highly temperature dependent viscosity

Energy Technology Data Exchange (ETDEWEB)

Burns, S.P. [Texas Univ., Austin, TX (United States); Gianoulakis, S.E. [Sandia National Labs., Albuquerque, NM (United States)

1995-07-01

A numerical solution for buoyant natural convection within a square enclosure containing a fluid with highly temperature dependent viscosity is presented. Although the fluid properties employed do not represent any real fluid, the large variation in the fluid viscosity with temperature is characteristic of turbulent flow modeling with eddy-viscosity concepts. Results are obtained using a primitive variable formulation and the resistor method. The results presented include velocity, temperature and pressure distributions within the enclosure as well as shear stress and heat flux distributions along the enclosure walls. Three mesh refinements were employed and uncertainty values are suggested for the final mesh refinement. These solutions are part of a contributed benchmark solution set for the subject problem.

Viscosity measurements on metal melts at high pressure and viscosity calculations for the earth's core

International Nuclear Information System (INIS)

Mineev, Vladimir N; Funtikov, Aleksandr I

2004-01-01

A review is given of experimental and calculated data on the viscosity of iron-based melts on the melting curve. The interest in these data originates in the division of opinion on whether viscosity increases rather moderately or considerably in the high-pressure range. This disagreement is especially pronounced in the interpretation of the values of molten iron and its compounds in the environment of the earth's outer core. The conclusion on a substantial rise in viscosity mostly follows from the universal law, proposed by Brazhkin and Lyapin [1], of viscosity changing along the metal melting curve in the high-pressure range. The review analyzes available experimental and computational data, including the most recent ones. Data on viscosity of metals under shock wave compression in the megabar pressure range are also discussed. It is shown that data on viscosity of metal melts point to a small increase of viscosity on the melting curve. Specifics are discussed of the phase diagram of iron made more complex by the presence of several phase transitions and by the uncertainty in the position of the melting curve in the high-pressure range. Inaccuracies that arise in extrapolating the results of viscosity measurements to the pressure range corresponding to the earth's core environment are pointed out. (reviews of topical problems)

Study on viscosity measurement using fiber Bragg grating micro-vibration

International Nuclear Information System (INIS)

Song, Le; Fang, Fengzhou; Zhao, Jibo

2013-01-01

It is now ascertained that traditional electric sensors are vulnerable to electromagnetic interference when measuring viscosity. Here, we propose a new viscosity-sensitive structure based on the fiber Bragg grating (FBG) sensing principle and a micro-vibration measurement method. The symmetric micro-vibration motivation method is also described, and a mathematical model for compensational voltage and fluid viscosity is established. The probe amplitude, which is produced by reciprocating stimulation, is accessible by means of an FBG sensor mounted on an equal-strength beam. Viscosity can be therefore calculated using a demodulation technique based on linear edge filtering with long period grating. After performing a group of verifying tests, the sensor has been subsequently calibrated with a series of standard fluids to determine uncertain parameters in the mathematical model. The results of the experiment show that the relative measurement error was less than 2% when the viscosity ranged from 200 to 500 mPa s. The proposed architecture utilizes the characteristics of anti-interference, fast response speed, high resolution and compact structure of FBG, thereby offering a novel modality to achieve an online viscosity measurement. (paper)

Relating Fresh Concrete Viscosity Measurements from Different Rheometers.

Science.gov (United States)

Ferraris, Chiara F; Martys, Nicos S

2003-01-01

Concrete rheological properties need to be properly measured and predicted in order to characterize the workability of fresh concrete, including special concretes such as self-consolidating concrete (SCC). It was shown by a round-robin test held in 2000 [1,2] that different rheometer designs gave different values of viscosity for the same concrete. While empirical correlation between different rheometers was possible, for a procedure that is supposed to "scientifically" improve on the empirical slump tests, this situation is unsatisfactory. To remedy this situation, a new interpretation of the data was developed. In this paper, it is shown that all instruments tested could be directly and quantitatively compared in terms of relative plastic viscosity instead of the plastic viscosity alone. This should eventually allow the measurements from various rheometer designs to be directly calibrated against known standards of plastic viscosity, putting concrete rheometry and concrete workability on a sounder materials science basis.

Thermodynamic study of three pharmacologically significant drugs: Density, viscosity, and refractive index measurements at different temperatures

Energy Technology Data Exchange (ETDEWEB)

Iqbal, Muhammad Javed [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan)], E-mail: mjiqauchem@yahoo.com; Chaudhry, Mansoora Ahmed [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

2009-02-15

Measurements of density, viscosity, and refractive index of three pharmacologically significant drugs, i.e. diclofenac sodium, cetrizine, and doxycycline have been carried in aqueous medium at T = (293.15 to 313.15) K. An automated vibrating-tube densimeter, viscometer, and refractometer are used in a concentration range from (7.5) . 10{sup -3} to 25 . 10{sup -3}) mol . kg{sup -1}. The precise density results are used to evaluate the apparent molar volume, partial molar volume, thermal expansion coefficient, partial molar expansivity, and the Hepler's constant. Viscosity results are used to calculate the Jones-Dole viscosity B-coefficient, free energy of activation of the solute and solvent, activation enthalpy, and activation entropy. The molar refractive indices of the drug solutions can be employed to calculate molar refraction. It is inferred from these results that the above mentioned drugs act as structure-making compounds due to hydrophobic hydration of the molecules in the drugs.

High-pressure viscosity measurements for the ethanol plus toluene binary system

DEFF Research Database (Denmark)

Zeberg-Mikkelsen, Claus Kjær; Baylaucq, A.; Watson, G.

2005-01-01

measured with a classical capillary viscometer (Ubbelohde) with an uncertainty of 1%. A total of 209 experimental measurements have been obtained for this binary system, which reveals a non-monotonic behavior of the viscosity as a function of the composition, with a minimum. The viscosity behavior...... interacting system showing a negative deviation from ideality. The viscosity of this binary system is represented by the Grunberg-Nissan and the Katti-Chaudhri mixing laws with an overall uncertainty of 12% and 8%, respectively. The viscosity of methanol (23 point) has also been measured in order to verify...

Experimental viscosity measurements of biodiesels at high pressure

Directory of Open Access Journals (Sweden)

Schaschke C.J.

2016-01-01

Full Text Available The viscosity of biodiesels of soybean and rapeseed biodiesels blended with mineral diesel fuel were measured at pressures of up to 200 MPa. Using a falling sinker-type viscometer reproducible viscosity data were obtained based on the time taken for a sinker to descend a fixed distance down an enclosed tube under the influence of gravity. Measurements were taken using pressures which correspond to those of interest in automotive common rail diesel engines, and at temperatures of between 25ºC and 80ºC. In all cases, the viscosity of the biodiesel blends were found to increase exponentially for which the blends were noted as being more viscous than pure mineral fuels. A pressure-freezing effect was not observed for the blends.

Near-surface viscosity measurements with a love acoustic wave device

International Nuclear Information System (INIS)

Collings, A.F.; Cooper, B.J.; Lappas, S.; Sor, J.A.

1999-01-01

Full text: In the last decade, considerable research effort has been directed towards interfacing piezoelectric transducers with biological detection systems to produce efficient and highly selective biosensors. Several types of piezoelectric or, more specifically, acoustic wave transducers have been investigated. Our group has developed Love wave (guided surface skimming wave) devices which are made by attaching a thin overlayer with the appropriate acoustic properties to the surface of a conventional surface horizontal mode device. An optimised layer concentrates most of the propagating wave energy in the guiding layer and can improve the device sensitivity in detecting gas-phase mass loading on the surface some 20- to 40-fold. Love wave devices used in liquid phase sensing will also respond to viscous, as well as mass, loading on the device surface. We have studied the propagation of viscous waves into liquid sitting on a Love wave device both theoretically and experimentally. Modelling of the effect of a viscous liquid layer on a Love wave propagating in a layered medium predicts the velocity profile in the solid substrate and in the adjoining liquid. This is a function of the thickness of the guiding layer, the elastic properties of the guiding layer and the piezoelectric substrate, and of the viscosity and density of the liquid layer. We report here on measurements of the viscosity of aqueous glycerine solutions made with a quartz Love wave device with a 5.5 μm SiO 2 guiding layer. The linear relationship between the decrease in the device frequency and the square root of the viscosity density product is accurately observed at Newtonian viscosities. At higher viscosities, there is an increase in damping, the insertion loss of the device saturates, Δf is no longer proportional to (ηp) l/2 and reaches a maximum. We also show results for the determination of the gelation time in protein and inorganic aqueous gels and for the rate of change of viscosity with

Microfluidic method for measuring viscosity using images from smartphone

Science.gov (United States)

Kim, Sooyeong; Kim, Kyung Chun; Yeom, Eunseop

2018-05-01

The viscosity of a fluid is the most important characteristic in fluid rheology. Many microfluidic devices have been proposed for easily measuring the fluid viscosity of small samples. A hybrid system consisting of a smartphone and microfluidic device can offer a mobile laboratory for performing a wide range of detection and analysis functions related to healthcare. In this study, a new mobile sensing method based on a microfluidic device was proposed for fluid viscosity measurements. By separately delivering sample and reference fluids into the two inlets of a Y-shaped microfluidic device, an interfacial line is induced at downstream of the device. Because the interfacial width (W) between the sample and reference fluid flows was determined by their pressure ratio, the viscosity (μ) of the sample could be estimated by measuring the interfacial width. To distinguish the interfacial width of a sample, optical images of the flows at downstream of the Y-shaped microfluidic device were acquired using a smartphone. To check the measurement accuracy of the proposed method, the viscosities of glycerol mixtures were compared with those measured by a conventional viscometer. The proposed technique was applied to monitor the variations in blood and oil samples depending on storage or rancidity. We expect that this mobile sensing method based on a microfluidic device could be utilized as a viscometer with significant advantages in terms of mobility, ease-of-operation, and data management.

Measuring Shear Viscosity Using Transverse Momentum Correlations in Relativistic Nuclear Collisions

International Nuclear Information System (INIS)

Gavin, Sean; Abdel-Aziz, Mohamed

2006-01-01

Elliptic flow measurements at the Brookhaven National Laboratory Relativistic Heavy Ion Collider suggest that quark-gluon fluid flows with very little viscosity compared to weak-coupling expectations, challenging theorists to explain why this fluid is so nearly ''perfect.'' It is therefore vital to find quantitative experimental information on the viscosity of the fluid. We propose that measurements of transverse momentum fluctuations can be used to determine the shear viscosity. We use current data to estimate the viscosity-to-entropy ratio in the range from 0.08 to 0.3 and discuss how future measurements can reduce this uncertainty

On viscosity measurements of nanofluids in micro and mini tube flow

International Nuclear Information System (INIS)

Egan, V M; Walsh, P A; Walsh, E J

2009-01-01

This study presents measurements on the relative viscosity of Al 2 O 3 nanofluids, obtained using capillary and rotational viscometers. Suspension volume concentrations between 0.3% and 6.3% were considered and all exhibited Newtonian behaviour. This paper questions previously published data (Jang et al 2007 Appl. Phys. Lett. 91 243112) which show effective viscosity measurements of nanofluids to be strongly dependent on the tube dimension used in a microscale capillary viscometer. Hence, tubes of diameter 337 μm and 1017 μm were employed but no effect on relative viscosity was observed as all measurements compared favourably. Additionally, all viscosity measurements were found to correlate well using classical models when aggregate size was considered in calculating volume concentration.

A viscosity measurement during the high pressure phase transition in triolein

International Nuclear Information System (INIS)

Siegoczynski, R M; Rostocki, A J; Kielczynski, P; Szalewski, M

2008-01-01

The high-pressure properties of triolein, a subject of extensive research at the Faculty of Physics of Warsaw University of Technology (WUT) have been enhanced by the results of viscosity measurement within the pressure range up to 0.8 GPa. For the measurement the authors have adopted a new ultrasonic method based on Bleustein-Gulyaev waves, successfully developed earlier for the low pressures in the Section of Acoustoelectronics of the Institute of Fundamental Technological Research. The measurements have shown: 1. Exponential rise of viscosity with pressure up to 0.5 GPa. 2. Extraordinary increment of viscosity at constant pressure during phase transition. 3. Further exponential rise of viscosity with pressure of the high-pressure phase of triolein. 4. The pressure exponents of the viscosity of both phases were different (the high-pressure phase had much smaller exponent). 5. The decomposition of the high pressure phase due to the slow decompression have shown very large hysteresis of viscosity on pressure dependence

Viscosity measurements of molten refractory metals using an electrostatic levitator

International Nuclear Information System (INIS)

Ishikawa, Takehiko; Paradis, Paul-François; Okada, Junpei T; Watanabe, Yuki

2012-01-01

Viscosities of several refractory metals (titanium, nickel, zirconium, niobium, ruthenium, rhodium, hafnium, iridium and platinum) and terbium have been measured by the oscillation drop method with an improved procedure. The measured data were less scattered than our previous measurements. Viscosities at their melting temperatures showed good agreement with literature values and some predicted values. (paper)

On the measurement of the relative viscosity of suspensions

International Nuclear Information System (INIS)

Acrivos, A.; Fan, X.; Mauri, R.

1994-01-01

The relative viscosity of a suspension of rigid, noncolloidal particles immersed in a Newtonian fluid was measured in a Couette device and was found to be shear thinning even for values of the solids fraction as low as 20%. Although such behavior was reported previously, no satisfactory explanation appears to have been given thus far. It shall be shown presently, however, that, at least for our systems, this shear-thinning effect was due to a slight mismatch in the densities of the two phases. Moreover, the apparent relative viscosities measured in our apparatus were found to be in excellent agreement with those predicted theoretically using a model, originally proposed by Leighton and Acrivos [Chem. Eng. Sci. 41, 1377--1384 (1986)], to describe viscous resuspension, according to which the measured relative viscosity should depend on the bulk particle concentration and on the dimensionless Shields number A, and should attain its correct value for a well-mixed suspension only as A→∞. The predictions of this model are also in excellent agreement with the measured transient response of the apparent relative viscosity due to a sudden change in the shear rate

Measurement of viscosity of gaseous mixtures at atmospheric pressure

Science.gov (United States)

Singh, J. J.; Mall, G. H.; Chegini, H.

1986-01-01

Coefficients of viscosity of various types of gas mixtures, including simulated natural-gas samples, have been measured at atmospheric pressure and room temperature using a modified capillary tube method. Pressure drops across the straight capillary tube section of a thermal mass flowmeter were measured for small, well-defined, volume flow rates for the test gases and for standard air. In this configuration, the flowmeter provides the volumetric flow rates as well as a well-characterized capillary section for differential pressure measurements across it. The coefficients of viscosity of the test gases were calculated using the reported value of 185.6 micro P for the viscosity of air. The coefficients of viscosity for the test mixtures were also calculated using Wilke's approximation of the Chapman-Enskog (C-E) theory. The experimental and calculated values for binary mixtures are in agreement within the reported accuracy of Wilke's approximation of the C-E theory. However, the agreement for multicomponent mixtures is less satisfactory, possible because of the limitations of Wilkes's approximation of the classical dilute-gas state model.

Development, implementation, and characterization of a standalone embedded viscosity measurement system based on the impedance spectroscopy of a vibrating wire sensor

Science.gov (United States)

Santos, José; Janeiro, Fernando M.; Ramos, Pedro M.

2015-10-01

This paper presents an embedded liquid viscosity measurement system based on a vibrating wire sensor. Although multiple viscometers based on different working principles are commercially available, there is still a market demand for a dedicated measurement system capable of performing accurate, fast measurements and requiring little or no operator training for simple systems and solution monitoring. The developed embedded system is based on a vibrating wire sensor that works by measuring the impedance response of the sensor, which depends on the viscosity and density of the liquid in which the sensor is immersed. The core of the embedded system is a digital signal processor (DSP) which controls the waveform generation and acquisitions for the measurement of the impedance frequency response. The DSP also processes the acquired waveforms and estimates the liquid viscosity. The user can interact with the measurement system through a keypad and an LCD or through a computer with a USB connection for data logging and processing. The presented system is tested on a set of viscosity standards and the estimated values are compared with the standard manufacturer specified viscosity values. A stability study of the measurement system is also performed.

Development, implementation, and characterization of a standalone embedded viscosity measurement system based on the impedance spectroscopy of a vibrating wire sensor

International Nuclear Information System (INIS)

Santos, José; Ramos, Pedro M; Janeiro, Fernando M

2015-01-01

This paper presents an embedded liquid viscosity measurement system based on a vibrating wire sensor. Although multiple viscometers based on different working principles are commercially available, there is still a market demand for a dedicated measurement system capable of performing accurate, fast measurements and requiring little or no operator training for simple systems and solution monitoring. The developed embedded system is based on a vibrating wire sensor that works by measuring the impedance response of the sensor, which depends on the viscosity and density of the liquid in which the sensor is immersed. The core of the embedded system is a digital signal processor (DSP) which controls the waveform generation and acquisitions for the measurement of the impedance frequency response. The DSP also processes the acquired waveforms and estimates the liquid viscosity. The user can interact with the measurement system through a keypad and an LCD or through a computer with a USB connection for data logging and processing. The presented system is tested on a set of viscosity standards and the estimated values are compared with the standard manufacturer specified viscosity values. A stability study of the measurement system is also performed. (paper)

Gravimetric capillary method for kinematic viscosity measurements

Science.gov (United States)

Rosenberger, Franz; Iwan, J.; Alexander, D.; Jin, Wei-Qing

1992-01-01

A novel version of the capillary method for viscosity measurements of liquids is presented. Viscosity data can be deduced in a straightforward way from mass transfer data obtained by differential weighing during the gravity-induced flow of the liquid between two cylindrical chambers. Tests of this technique with water, carbon tetrachloride, and ethanol suggest that this arrangement provides an accuracy of about +/- 1 percent. The technique facilitates operation under sealed, isothermal conditions and, thus can readily be applied to reactive and/or high vapor pressure liquids.

Separate density and viscosity measurements of unknown liquid using quartz crystal microbalance

Directory of Open Access Journals (Sweden)

Feng Tan

2016-09-01

Full Text Available Aqueous liquids have a wide range of applications in many fields. Basic physical properties like the density and the viscosity have great impacts on the functionalities of a given ionic liquid. For the millions kinds of existing liquids, only a few have been systematically measured with the density and the viscosity using traditional methods. However, these methods are limited to measure the density and the viscosity of an ionic liquid simultaneously especially in processing micro sample volumes. To meet this challenge, we present a new theoretical model and a novel method to separate density and viscosity measurements with single quartz crystal microbalance (QCM in this work. The agreement of experimental results and theocratical calculations shows that the QCM is capable to measure the density and the viscosity of ionic liquids.

Should you trust your heavy oil viscosity measurement?

Energy Technology Data Exchange (ETDEWEB)

Nelson, L.; Miller, K.; Almond, R. [Petrovera Resources Ltd., Edmonton, AB (Canada)

2003-07-01

For the last 60 years, the heavy oil and bitumen reservoirs from western Canada have been exploited with varying degrees of success. There are many factors that may effect heavy oil and bitumen production rates. Primary production rates, which vary greatly from field to field, were found to improve with the addition of steam. Viscosity is the single most valued criteria in predicting cold production response from a new field. It is also the criteria used to determine whether thermal process are needed to reduce oil viscosity, or whether horizontal or vertical wells should be used. This study examined why production forecasts based on oil viscosity alone have been poor. It is based on an extensive data collection project in the Elk Point area reservoir which has lower than expected and erratic cold production rates. Viscosity values from the same wells were found to vary by a factor of four or more. One of the objectives of this study was to encourage commercial labs to develop an industry-wide standard method of heavy oil sample cleaning and viscosity measurement. It is generally understood that viscosity increases with an increase in the concentration of asphaltenes, but there is little information to quantify the relationship. Some studies suggest that viscosity increases logarithmically with increasing asphaltenes. It was concluded that the prediction of the viscosity of heavy oils and bitumens is very empirical, but there are ways to improve data comparisons and evaluation by applying available information from other scientific fields. 23 refs., 5 tabs., 6 figs.

On the Measurements of Numerical Viscosity and Resistivity in Eulerian MHD Codes

Energy Technology Data Exchange (ETDEWEB)

Rembiasz, Tomasz; Obergaulinger, Martin; Cerdá-Durán, Pablo; Aloy, Miguel-Ángel [Departamento de Astronomía y Astrofísica, Universidad de Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain); Müller, Ewald, E-mail: tomasz.rembiasz@uv.es [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany)

2017-06-01

We propose a simple ansatz for estimating the value of the numerical resistivity and the numerical viscosity of any Eulerian MHD code. We test this ansatz with the help of simulations of the propagation of (magneto)sonic waves, Alfvén waves, and the tearing mode (TM) instability using the MHD code Aenus. By comparing the simulation results with analytical solutions of the resistive-viscous MHD equations and an empirical ansatz for the growth rate of TMs, we measure the numerical viscosity and resistivity of Aenus. The comparison shows that the fast magnetosonic speed and wavelength are the characteristic velocity and length, respectively, of the aforementioned (relatively simple) systems. We also determine the dependence of the numerical viscosity and resistivity on the time integration method, the spatial reconstruction scheme and (to a lesser extent) the Riemann solver employed in the simulations. From the measured results, we infer the numerical resolution (as a function of the spatial reconstruction method) required to properly resolve the growth and saturation level of the magnetic field amplified by the magnetorotational instability in the post-collapsed core of massive stars. Our results show that it is most advantageous to resort to ultra-high-order methods (e.g., the ninth-order monotonicity-preserving method) to tackle this problem properly, in particular, in three-dimensional simulations.

Options for refractive index and viscosity matching to study variable density flows

Science.gov (United States)

Clément, Simon A.; Guillemain, Anaïs; McCleney, Amy B.; Bardet, Philippe M.

2018-02-01

Variable density flows are often studied by mixing two miscible aqueous solutions of different densities. To perform optical diagnostics in such environments, the refractive index of the fluids must be matched, which can be achieved by carefully choosing the two solutes and the concentration of the solutions. To separate the effects of buoyancy forces and viscosity variations, it is desirable to match the viscosity of the two solutions in addition to their refractive index. In this manuscript, several pairs of index matched fluids are compared in terms of viscosity matching, monetary cost, and practical use. Two fluid pairs are studied in detail, with two aqueous solutions (binary solutions of water and a salt or alcohol) mixed into a ternary solution. In each case: an aqueous solution of isopropanol mixed with an aqueous solution of sodium chloride (NaCl) and an aqueous solution of glycerol mixed with an aqueous solution of sodium sulfate (Na_2SO_4). The first fluid pair allows reaching high-density differences at low cost, but brings a large difference in dynamic viscosity. The second allows matching dynamic viscosity and refractive index simultaneously, at reasonable cost. For each of these four solutes, the density, kinematic viscosity, and refractive index are measured versus concentration and temperature, as well as wavelength for the refractive index. To investigate non-linear effects when two index-matched, binary solutions are mixed, the ternary solutions formed are also analyzed. Results show that density and refractive index follow a linear variation with concentration. However, the viscosity of the isopropanol and NaCl pair deviates from the linear law and has to be considered. Empirical correlations and their coefficients are given to create index-matched fluids at a chosen temperature and wavelength. Finally, the effectiveness of the refractive index matching is illustrated with particle image velocimetry measurements performed for a buoyant jet in a

Certain laws governing the influence of high molecular polymer additives on specific electrical conductivity and viscosity of zincate alkaline solution

Energy Technology Data Exchange (ETDEWEB)

Dmitrenko, V.Ye.; Toropetsera, T.N.; Zubov, M.S.

1983-01-01

A study was made of the influence of polymer additives of different nature: polyelectrolyte, copolymer of ethylene with maleic anhydride, polymethacrylic acid and nonpolyectrolyte copolymer of vinyl alcohol with vinyleneglycol and polyvinyleneglycol on specific electrical conductance and viscosity of the zincate alkaline solution. It is indicated that with an increase in the content of additives, the specific conductance of the solution diminishes according to a linear law, while the viscosity rises. The additives of polyelectrolyte nature reduce more strongly the specific conductance and increase the viscosity than the nonpolyelectrolyte additives. From a comparison of the data on specific conductance and viscosity the following conclusion is drawn: the more the polymer ''structures'' the zincate alkaline solution, the more strongly it reduces its specific electrical conductance.

Effects of the positioning force of electrostatic levitators on viscosity measurements

International Nuclear Information System (INIS)

Ishikawa, Takehiko; Paradis, Paul-Francois; Koike, Noriyuki; Watanabe, Yuki

2009-01-01

Electrostatic levitators use strong electric fields to levitate and accurately position a sample against gravity. In this study, the effects of the electric field are investigated with regard to viscosity measurements conducted with the oscillating drop method. The effects of the external field on viscosity measurements are experimentally confirmed by changing the sample size. Moreover, a numerical simulation based on a simple mass-spring-damper system can reproduce the experimental observations. Based on the above results, measurement procedures are improved. These help to minimize the effect of the positioning force and to increase the accuracy of the viscosity measurements.

Measurement of viscosity as a means to identify irradiated food

International Nuclear Information System (INIS)

Nuernberger, E.; Heide, L.; Boegl, K.W.

1990-01-01

The measurement of viscosity is a simple method to identify previous irradiation of some kinds of spices and foods, at least in combination with other methods. A possible change of the soaking capacity was examined up to a storage period of 18 months after irradiation of black pepper, white pepper, cinnamon, ginger and onion powder with a radiation dose of 10 kGy each. After irradiation, either increased or decreased viscosity values were measured; the results showed, also after the 18-months-storage period, considerable differences of the viscosity behaviour in non-irradiated and irradiated samples. The time of storage had no effect to the individual viscosity values, so that this method could also be applied to the examined spices after a longer storage period. (orig.) With 51 figs., 25 tabs [de

Apparent molar volumes and viscosity B-coefficients of caffeine in aqueous thorium nitrate solutions at T = (298.15, 308.15, and 318.15) K

International Nuclear Information System (INIS)

Sinha, Biswajit; Roy, Pran Kumar; Sarkar, Bipul Kumar; Brahman, Dhiraj; Roy, Mahendra Nath

2010-01-01

Apparent molar volumes φ V and viscosity B-coefficients for caffeine in (0.00, 0.03, 0.05, and 0.07) mol . dm -3 aqueous thorium nitrate, Th(NO 3 ) 4 , solutions were determined from solution density and viscosity measurements over the temperature range (298.15 to 318.15) K as function of concentration of caffeine and the relation: φ V 0 =a 0 +a 1 T+a 2 T 2 , have been used to describe the temperature dependence of the standard partial molar volumes φ V 0 . These results have been used to deduce the standard volumes of transfer Δφ V 0 and viscosity B-coefficients of transfer ΔB for caffeine from water to aqueous Th(NO 3 ) 4 solutions for rationalizing various interactions in the ternary solutions. The structure-making or breaking ability of caffeine has been discussed in terms of the sign of (δ 2 φ V 0 /δT 2 ) P . The Friedman-Krishnan co-sphere model was used to explain the transfer volume of caffeine with increasing Th(NO 3 ) 4 molarity. The activation parameters of viscous flow for the ternary solutions were also discussed in terms of transition state theory.

Viscosity estimation utilizing flow velocity field measurements in a rotating magnetized plasma

International Nuclear Information System (INIS)

Yoshimura, Shinji; Tanaka, Masayoshi Y.

2008-01-01

The importance of viscosity in determining plasma flow structures has been widely recognized. In laboratory plasmas, however, viscosity measurements have been seldom performed so far. In this paper we present and discuss an estimation method of effective plasma kinematic viscosity utilizing flow velocity field measurements. Imposing steady and axisymmetric conditions, we derive the expression for radial flow velocity from the azimuthal component of the ion fluid equation. The expression contains kinematic viscosity, vorticity of azimuthal rotation and its derivative, collision frequency, azimuthal flow velocity and ion cyclotron frequency. Therefore all quantities except the viscosity are given provided that the flow field can be measured. We applied this method to a rotating magnetized argon plasma produced by the Hyper-I device. The flow velocity field measurements were carried out using a directional Langmuir probe installed in a tilting motor drive unit. The inward ion flow in radial direction, which is not driven in collisionless inviscid plasmas, was clearly observed. As a result, we found the anomalous viscosity, the value of which is two orders of magnitude larger than the classical one. (author)

Viscosity Solutions for a System of Integro-PDEs and Connections to Optimal Switching and Control of Jump-Diffusion Processes

International Nuclear Information System (INIS)

Biswas, Imran H.; Jakobsen, Espen R.; Karlsen, Kenneth H.

2010-01-01

We develop a viscosity solution theory for a system of nonlinear degenerate parabolic integro-partial differential equations (IPDEs) related to stochastic optimal switching and control problems or stochastic games. In the case of stochastic optimal switching and control, we prove via dynamic programming methods that the value function is a viscosity solution of the IPDEs. In our setting the value functions or the solutions of the IPDEs are not smooth, so classical verification theorems do not apply.

Effect of temperature on the partial molar volume, isentropic compressibility and viscosity of DL-2-aminobutyric acid in water and in aqueous sodium chloride solutions

International Nuclear Information System (INIS)

Romero, Carmen M.; Rodríguez, Diana M.; Ribeiro, Ana C.F.; Esteso, Miguel A.

2017-01-01

Highlights: • Apparent volumes, apparent compressibilities, viscosities of DL-2-aminobutyric acid. • Effect of temperature on the values for these properties. • Hydrophobic and hydrophilic interactions and the effect of sodium chloride. - Abstract: Density, sound velocity and viscosity of DL-2-aminobutyric acid in water and in aqueous sodium chloride solutions have been measured at temperatures of (293.15, 298.15, 303.15, 308.15 and 313.15) K. The experimental results were used to determine the apparent molar volume and the apparent molar compressibility as a function of composition at these temperatures. The limiting values of both the partial molar volume and the partial molar adiabatic compressibility at infinite dilution of DL-2-aminobutyric acid in water and in aqueous sodium chloride solutions were determined at each temperature. The experimental viscosity values were adjusted by a least-squares method to a second order equation as proposed by Tsangaris-Martin to obtain the viscosity B coefficient which depends on the size, shape and charge of the solute molecule. The influence of the temperature on the behaviour of the selected properties is discussed in terms of both the solute hydration and the balance between hydrophobic and hydrophilic interactions between the acids and water, and the effect of the sodium chloride concentration.

Gas viscosity measurement with diamagnetic-levitation viscometer based on electromagnetically spinning system.

Science.gov (United States)

Shimokawa, Y; Matsuura, Y; Hirano, T; Sakai, K

2016-12-01

Utilizing a graphite-disk probe attached with a thin aluminum disk, we have developed a friction-free viscosity measurement system. The probe is levitated above a NdFeB magnet because of diamagnetic effect and rotated by an electromagnetically induced torque. The probe is absolutely free form mechanical friction, and therefore, the accurate measurements of the viscosity of gases can be achieved. To demonstrate the accuracy and sensitivity of our method, we measured the viscosity of 8 kinds of gases and its temperature change from 278 K to 318 K, and we confirmed a good agreement between the obtained values and literature values. This paper demonstrates that our method has the ability to measure the fluid viscosity in the order of μPa ⋅ s.

Gas viscosity measurement with diamagnetic-levitation viscometer based on electromagnetically spinning system

Science.gov (United States)

Shimokawa, Y.; Matsuura, Y.; Hirano, T.; Sakai, K.

2016-12-01

Utilizing a graphite-disk probe attached with a thin aluminum disk, we have developed a friction-free viscosity measurement system. The probe is levitated above a NdFeB magnet because of diamagnetic effect and rotated by an electromagnetically induced torque. The probe is absolutely free form mechanical friction, and therefore, the accurate measurements of the viscosity of gases can be achieved. To demonstrate the accuracy and sensitivity of our method, we measured the viscosity of 8 kinds of gases and its temperature change from 278 K to 318 K, and we confirmed a good agreement between the obtained values and literature values. This paper demonstrates that our method has the ability to measure the fluid viscosity in the order of μPa ṡ s.

Effects of surfactant micelles on viscosity and conductivity of poly(ethylene glycol) solutions

Science.gov (United States)

Wang, Shun-Cheng; Wei, Tzu-Chien; Chen, Wun-Bin; Tsao, Heng-Kwong

2004-03-01

The neutral polymer-micelle interaction is investigated for various surfactants by viscometry and electrical conductometry. In order to exclude the well-known necklace scenario, we consider aqueous solutions of low molecular weight poly(ethylene glycol) (2-20)×103, whose radial size is comparable to or smaller than micelles. The single-tail surfactants consist of anionic, cationic, and nonionic head groups. It is found that the viscosity of the polymer solution may be increased several times by micelles if weak attraction between a polymer segment and a surfactant exists, ɛsolutions may be significantly hindered by cooperative interactions between polymers and micelles. Even though ɛ is small, the interaction energy between a macromolecule and a micelle can be a few kBT due to many contacts, and thus leads to polymer adsorption on micelles' surfaces. The rapid growth of the viscosity with surfactant concentration is therefore attributed to the considerable cross links among micelles and polymers (transient network). In addition to substantial alteration of the transport properties, this weak interaction also influences the onset point of thermodynamic instability associated with polymer-surfactant solutions. The examples include the decrease of critical aggregation concentration for ionic surfactant and clouding point for nonionic surfactant due to PEG addition.

Measure-valued solutions to the complete Euler system revisited

Science.gov (United States)

Březina, Jan; Feireisl, Eduard

2018-06-01

We consider the complete Euler system describing the time evolution of a general inviscid compressible fluid. We introduce a new concept of measure-valued solution based on the total energy balance and entropy inequality for the physical entropy without any renormalization. This class of so-called dissipative measure-valued solutions is large enough to include the vanishing dissipation limits of the Navier-Stokes-Fourier system. Our main result states that any sequence of weak solutions to the Navier-Stokes-Fourier system with vanishing viscosity and heat conductivity coefficients generates a dissipative measure-valued solution of the Euler system under some physically grounded constitutive relations. Finally, we discuss the same asymptotic limit for the bi-velocity fluid model introduced by H.Brenner.

Viscosity in Modified Gravity 

Directory of Open Access Journals (Sweden)

Iver Brevik

2012-11-01

Full Text Available A bulk viscosity is introduced in the formalism of modified gravity. It is shownthat, based on a natural scaling law for the viscosity, a simple solution can be found forquantities such as the Hubble parameter and the energy density. These solutions mayincorporate a viscosity-induced Big Rip singularity. By introducing a phase transition inthe cosmic fluid, the future singularity can nevertheless in principle be avoided. 

Clinical diagnostic of pleural effusions using a high-speed viscosity measurement method

Science.gov (United States)

Hurth, Cedric; Klein, Katherine; van Nimwegen, Lena; Korn, Ronald; Vijayaraghavan, Krishnaswami; Zenhausern, Frederic

2011-08-01

We present a novel bio-analytical method to discriminate between transudative and exudative pleural effusions based on a high-speed video analysis of a solid glass sphere impacting a liquid. Since the result depends on the solution viscosity, it can ultimately replace the battery of biochemical assays currently used. We present results obtained on a series of 7 pleural effusions obtained from consenting patients by analyzing both the splash observed after the glass impactor hits the liquid surface, and in a configuration reminiscent of the drop ball viscometer with added sensitivity and throughput provided by the high-speed camera. The results demonstrate distinction between the pleural effusions and good correlation with the fluid chemistry analysis to accurately differentiate exudates and transudates for clinical purpose. The exudative effusions display a viscosity around 1.39 ± 0.08 cP whereas the transudative effusion was measured at 0.89 ± 0.09 cP, in good agreement with previous reports.

High-Pressure-High-Temperature Processing Reduces Maillard Reaction and Viscosity in Whey Protein-Sugar Solutions.

Science.gov (United States)

Avila Ruiz, Geraldine; Xi, Bingyan; Minor, Marcel; Sala, Guido; van Boekel, Martinus; Fogliano, Vincenzo; Stieger, Markus

2016-09-28

The aim of the study was to determine the influence of pressure in high-pressure-high-temperature (HPHT) processing on Maillard reactions and protein aggregation of whey protein-sugar solutions. Solutions of whey protein isolate containing either glucose or trehalose at pH 6, 7, and 9 were treated by HPHT processing or conventional high-temperature (HT) treatments. Browning was reduced, and early and advanced Maillard reactions were retarded under HPHT processing at all pH values compared to HT treatment. HPHT induced a larger pH drop than HT treatments, especially at pH 9, which was not associated with Maillard reactions. After HPHT processing at pH 7, protein aggregation and viscosity of whey protein isolate-glucose/trehalose solutions remained unchanged. It was concluded that HPHT processing can potentially improve the quality of protein-sugar-containing foods, for which browning and high viscosities are undesired, such as high-protein beverages.

High Resolution Viscosity Measurement by Thermal Noise Detection

Directory of Open Access Journals (Sweden)

Felipe Aguilar Sandoval

2015-11-01

Full Text Available An interferometric method is implemented in order to accurately assess the thermal fluctuations of a micro-cantilever sensor in liquid environments. The power spectrum density (PSD of thermal fluctuations together with Sader’s model of the cantilever allow for the indirect measurement of the liquid viscosity with good accuracy. The good quality of the deflection signal and the characteristic low noise of the instrument allow for the detection and corrections of drawbacks due to both the cantilever shape irregularities and the uncertainties on the position of the laser spot at the fluctuating end of the cantilever. Variation of viscosity below 0.03 mPa·s was detected with the alternative to achieve measurements with a volume as low as 50 µL.

Viscosity measurement - probably a means for detecting radiation treatment of spices?

International Nuclear Information System (INIS)

Heide, L.; Albrich, S.; Boegl, K.W.

1987-12-01

The viscosity of 13 different spices and dried vegetables in total was measured. Optimal conditions were first determined for each product, i.e. concentration, pH-value, temperature, particle size and soaking time. For method evaluation, examinations were primarily performed to study the effect of storage, the reproducibility and the influence of the different varieties of the same spice. In supplement, for pepper, the viscosity was measured as a function of radiation dose. In summation, significant changes in the gel forming capability after irradiation could be observed after preliminary experiments in 8 dried spices (ginger, carrots, leek, cloves, pepper, celery, cinnamon and onions). With 3 spices (ginger, pepper and cinnamon) could the results from examining all different varieties of the same spice be substantiated. An additional influence of storage time on viscosity could not be proved during the investigative period of 8 months. Generally seen, there is no possibility of being able to identify an irradiated spice on the basis of viscosity measurements alone, since the difference between the varieties of one and the same spice is considerably great. However, radiation treatment can be reliably excluded with ginger, pepper and cinnamon, if the viscosities are high (10-20 Pa x s). (orig./MG) [de

Bulk viscosity and cosmological evolution

International Nuclear Information System (INIS)

Beesham, A.

1996-01-01

In a recent interesting paper, Pimentel and Diaz-Rivera (Nuovo Cimento B, 109(1994) 1317) have derived several solutions with bulk viscosity in homogeneous and isotropic cosmological models. They also discussed the properties of these solutions. In this paper the authors relate the solutions of Pimentel and Diaz-Rivera by simple transformations to previous solutions published in the literature, showing that all the solutions can be derived from the known existing ones. Drawbacks to these approaches of studying bulk viscosity are pointed out, and better approaches indicated

Apparent molar volumes and viscosity B-coefficients of caffeine in aqueous thorium nitrate solutions at T = (298.15, 308.15, and 318.15) K

Energy Technology Data Exchange (ETDEWEB)

Sinha, Biswajit, E-mail: biswachem@gmail.co [Department of Chemistry, University of North Bengal, Darjeeling 734013 (India); Roy, Pran Kumar; Sarkar, Bipul Kumar; Brahman, Dhiraj [Department of Chemistry, University of North Bengal, Darjeeling 734013 (India); Roy, Mahendra Nath, E-mail: mahendraroy2002@yahoo.co.i [Department of Chemistry, University of North Bengal, Darjeeling 734013 (India)

2010-03-15

Apparent molar volumes phi{sub V} and viscosity B-coefficients for caffeine in (0.00, 0.03, 0.05, and 0.07) mol . dm{sup -3} aqueous thorium nitrate, Th(NO{sub 3}){sub 4}, solutions were determined from solution density and viscosity measurements over the temperature range (298.15 to 318.15) K as function of concentration of caffeine and the relation: phi{sub V}{sup 0}=a{sub 0}+a{sub 1}T+a{sub 2}T{sup 2}, have been used to describe the temperature dependence of the standard partial molar volumes phi{sub V}{sup 0}. These results have been used to deduce the standard volumes of transfer DELTAphi{sub V}{sup 0} and viscosity B-coefficients of transfer DELTAB for caffeine from water to aqueous Th(NO{sub 3}){sub 4} solutions for rationalizing various interactions in the ternary solutions. The structure-making or breaking ability of caffeine has been discussed in terms of the sign of (delta{sup 2}phi{sub V}{sup 0}/deltaT{sup 2}){sub P}. The Friedman-Krishnan co-sphere model was used to explain the transfer volume of caffeine with increasing Th(NO{sub 3}){sub 4} molarity. The activation parameters of viscous flow for the ternary solutions were also discussed in terms of transition state theory.

Electroosmotic flow in capillary channels filled with nonconstant viscosity electrolytes: exact solution of the Navier-Stokes equation.

Science.gov (United States)

Otevrel, Marek; Klepárník, Karel

2002-10-01

The partial differential equation describing unsteady velocity profile of electroosmotic flow (EOF) in a cylindrical capillary filled with a nonconstant viscosity electrolyte was derived. Analytical solution, based on the general Navier-Stokes equation, was found for constant viscosity electrolytes using the separation of variables (Fourier method). For the case of a nonconstant viscosity electrolyte, the steady-state velocity profile was calculated assuming that the viscosity decreases exponentially in the direction from the wall to the capillary center. Since the respective equations with nonconstant viscosity term are not solvable in general, the method of continuous binding conditions was used to solve this problem. In this method, an arbitrary viscosity profile can be modeled. The theoretical conclusions show that the relaxation times at which an EOF approaches the steady state are too short to have an impact on a separation process in any real systems. A viscous layer at the wall affects EOF significantly, if it is thicker than the Debye length of the electric double layer. The presented description of the EOF dynamics is applicable to any microfluidic systems.

Experimental density and viscosity measurements of di(2ethylhexyl)sebacate at high pressure

International Nuclear Information System (INIS)

Paredes, Xavier; Fandino, Olivia; Pensado, Alfonso S.; Comunas, Maria J.P.; Fernandez, Josefa

2012-01-01

Highlights: → We measure viscosities for di(2-ethylhexyl)sebacate from (298.15 to 398.15) K and up to 60 MPa. → We measure densities for DEHS from (298.15 to 373.15) K and from (0.1 to 60) MPa. → The reported and lit. data were used in a viscosity correlation from (273 to 491) K and up to 1.1 GPa. → This correlation could be used in industrial equipment that operate at high pressures. - Abstract: Experimental densities and dynamic viscosities of di(2-ethylhexyl)sebacate (DEHS) are the object of study in this work. DEHS could be a useful industrial reference fluid for moderately high viscosity at high pressures as it is often used as a pressure transmitting fluid. At atmospheric pressure the density and viscosity measurements have been performed in a rotational SVM 3000 Stabinger viscometer from (273.15 to 373.15) K, whereas from (0.1 to 60) MPa and from (298.15 to 398.15) K an automated Anton Paar DMA HPM vibrating-tube densimeter, and a high-pressure rolling-ball viscometer were used. Several Vogel-Fulcher-Tammann type equations were used to fit the experimental values of viscosity to the pressure and temperature. The measured viscosity data have been used together with previous data found in the literature to establish a correlation of the viscosity surface η(T, p) of DEHS, covering a temperature range from (273 to 491) K and pressure up to 1.1 GPa. This correlation could be used in industrial equipment like viscometers and other devices that operate at high pressures. Our viscosity data have also been fitted as a function of temperature and volume to the thermodynamic scaling model of Roland et al. [C.M. Roland, S. Bair, R. Casalini, J. Chem. Phys. 125 (2006) 124508].

Viscosity Measurements of SiO2-"FeO"-MgO System in Equilibrium with Metallic Fe

Science.gov (United States)

Chen, Mao; Raghunath, Sreekanth; Zhao, Baojun

2014-01-01

The present study delivers the measurements of viscosities in the SiO2-"FeO"-MgO system in equilibrium with metallic Fe. The rotational spindle technique was used for the measurements at the temperature range of 1523 K to 1773 K (1250 °C to 1500 °C). Molybdenum crucibles and spindles were employed in all measurements. The viscosity measurements were carried out at 31 to 47 mol pct SiO2 and up to 18.8 mol pct MgO. Analysis of the quenched sample by Electron probe X-ray microanalysis after the viscosity measurement enables the composition and microstructure of the slag to be directly linked with the viscosity. The replacement of "FeO" by MgO was found to increase viscosity and activation energy of the SiO2-"FeO"-MgO slags. The modified Quasi-chemical Viscosity Model was further optimized in this system based on the current viscosity measurements.

Viscosity Measurements of "FeO"-SiO2 Slag in Equilibrium with Metallic Fe

Science.gov (United States)

Chen, Mao; Raghunath, Sreekanth; Zhao, Baojun

2013-06-01

The current study delivered the measurements of viscosities in the system "FeO"-SiO2 in equilibrium with metallic Fe in the composition range between 15 and 40 wt pct SiO2. The experiments were carried out in the temperature range of 1473 K to 1773 K (1200 °C to 1500 °C) using a rotational spindle technique. An analysis of the quenched sample by electron probe X-ray microanalysis (EPMA) after the viscosity measurement enables the composition and microstructure of the slag to be directly linked with the viscosity. The current results are compared with available literature data. The significant discrepancies of the viscosity measurements in this system have been clarified. The possible reasons affecting the accuracy of the viscosity measurement have been discussed. The activation energies derived from the experimental data have a sharp increase at about 33 wt pct SiO2, which corresponds to the composition of fayalite (Fe2SiO4). The modified quasi-chemical model was constructed in the system "FeO"-SiO2 to describe the current viscosity data.

Viscosity Measurement: A Virtual Experiment - Abstract of Issues 9907W

Science.gov (United States)

Papadopoulos, N.; Pitta, A. T.; Markopoulos, N.; Limniou, M.; Lemos, M. A. N. D. A.; Lemos, F.; Freire, F. G.

1999-11-01

Viscosity Measurement: A Virtual Experiment simulates a series of viscosity experiments. Viscosity is an important subject in chemistry and chemical engineering. It is important when dealing with intermolecular forces in liquids and gases and it has enormous relevance in all technological aspects of equipment dealing with liquids or gases. Most university-level chemistry courses include viscosity to some extent. Viscosity Measurement includes three virtual experiments: an Ostwald viscometer simulator, a falling-ball viscometer simulator, and a balance simulator for a simple determination of the density of a liquid. The Ostwald viscometer simulator and the balance simulator allow the student to find out how composition and temperature influence the density and viscosity of an ethanol-water mixture. The falling-ball viscometer simulator allows the student to determine experimentally the size and density of the ball required to measure viscosity of various liquids. Each virtual experiment includes a corresponding theoretical section. Support from the program is sufficient to enable the students to carry out a virtual experiment sensibly and on their own. Preparation is not essential. Students can use the program unsupervised, thus saving staff time and allowing flexibility in students' time. The design of the program interface plays a key role in the success of a simulated experiment. Direct manipulation has greater intuitive appeal than alternative interface forms such as menus and has been observed to provide performance and learning advantages (1). We tried to design an interface that is visually attractive, is user friendly with simple and intuitive navigation, and provides appropriate schematic animations to clarify the principles of the laboratory procedures. The opening screen presents the virtual experiments that can be selected. Clicking an icon takes the student to the appropriate section. Viscosity Measurement allows the student to concentrate on the

A NOVEL INTERPRETATION OF CONCENTRATION DEPENDENCE OF VISCOSITY OF DILUTE POLYMER SOLUTION

Institute of Scientific and Technical Information of China (English)

Yan Pan; Rong-shi Cheng

2000-01-01

The concentration dependence of the reduced viscosity of dilute polymer solution is interpreted in the light of a new concept of the self-association of polymer chains in dilute solution. The apparent self-association constant is defined as the molar association constant divided by the molar mass of individual polymer chain and is numerically interconvertible with the Huggins coefficient. The molar association constant is directly proportional to the effective hydrodynamic volume of the polymer chain in solution and is irrespective of the chain architecture. The effective hydrodynamic volume accounts for the non-spherical conformation of a short polymer chain in solution and is a product of a shape factor and hydrodynamic volume. The observed enhancement of Huggins coefficient for short chain and branched polymer is satisfactorily interpreted by the concept of self-association. The concept of self-association allows us to predict the existence of a boundary concentration Cs (dynamic contact concentration) which divides the dilute polymer solution into two regions.

Viscosity and Liquid Density of Asymmetric n-Alkane Mixtures: Measurement and Modelling

DEFF Research Database (Denmark)

Queimada, António J.; Marrucho, Isabel M.; Coutinho, João A.P.

2005-01-01

Viscosity and liquid density Measurements were performed, at atmospheric pressure. in pure and mixed n-decane. n-eicosane, n-docosane, and n-tetracosane from 293.15 K (or above the melting point) up to 343.15 K. The viscosity was determined with a rolling ball viscometer and liquid densities...... with a vibrating U-tube densimeter. Pure component results agreed, oil average, with literature values within 0.2% for liquid density and 3% for viscosity. The measured data were used to evaluate the performance of two models for their predictions: the friction theory coupled with the Peng-Robinson equation...... of state and a corresponding states model recently proposed for surface tension, viscosity, vapor pressure, and liquid densities of the series of n-alkanes. Advantages and shortcoming of these models are discussed....

Viscosity of confined two-dimensional Yukawa liquids: A nonequilibrium method

International Nuclear Information System (INIS)

Landmann, S.; Kählert, H.; Thomsen, H.; Bonitz, M.

2015-01-01

We present a nonequilibrium method that allows one to determine the viscosity of two-dimensional dust clusters in an isotropic confinement. By applying a tangential external force to the outer parts of the cluster (e.g., with lasers), a sheared velocity profile is created. The decay of the angular velocity towards the center of the confinement potential is determined by a balance between internal (viscosity) and external friction (neutral gas damping). The viscosity can then be calculated from a fit of the measured velocity profile to a solution of the Navier-Stokes equation. Langevin dynamics simulations are used to demonstrate the feasibility of the method. We find good agreement of the measured viscosity with previous results for macroscopic Yukawa plasmas

Measurement and modeling of density and viscosity of n-octanol-kerosene-phosphoric acid solutions in a temperature range 293.15-333.15 K

Science.gov (United States)

Ye, Changwen; Pei, Xiangjun; Liu, J. C.

2016-12-01

Densities and viscosities have been measured for the n-octanol + aviation kerosene (AK) + phosphoric acid (H3PO4) system with the mass fraction of H3PO4 in the range from w = 0 to 0.26 and in the temperature of 293.15-333.15 K. According to the experimental data, the measured viscosities were found well correlated with the temperature and mass fraction of H3PO4, which were fitted to regression equations. The result shows that the dilution effect of AK is obvious under the same temperature and mass fraction of H3PO4.

Effect of ionic and non-ionic contrast media on whole blood viscosity, plasma viscosity and hematocrit in vitro

International Nuclear Information System (INIS)

Aspelin, P.

1978-01-01

The effect of the ionic contrast media diatrizoate, iocarmate and metrizoate and the non-ionic metrizamide on whole blood viscosity, plasma viscosity and hematocrit was investigated. All the contrast media increased whole blood and plasma viscosity and reduced the hematocrit. The whole blood viscosity increased with increasing osmolality of the contrast medium solutions, whereas the plasma viscosity increased with increasing viscosity of the contrast medium solutions. The higher the osmolality of the contrast media, the lower the hematocrit became. The normal shear-thinning (decreasing viscosity with increasing shear rate) property of blood was reduced when contrast medium was added to the blood. At 50 per cent volume ratio (contrast medium to blood), the ionic contrast media converted the blood into a shear-thickening (increasing viscosity with increasing shear rate) suspension, indicating a marked rigidification of the single red cell, while the non-ionic contrast medium still produced shear-thinning, indicating less rigidification of the red cell (p<0.01). (Auth.)

On the measurement of magnetic viscosity

Science.gov (United States)

Serletis, C.; Efthimiadis, K. G.

2012-08-01

This work is an investigation of the experimental method used for measuring the magnetic viscosity in a hard ferromagnetic material, i.e. the recording of the magnetization under constant applied field and temperature, after the material has been magnetically saturated. It investigates how the experimental results are affected by the initial conditions of the method (saturation field, field change rate and field oscillation prior to its stabilization), and by minor variations of field and temperature during the recording. Based on the arising conclusions and the use of a more complex fitting function of measurements, the accuracy and repeatability of experimental results is improved.

Spray-dried HPMC microparticles of Indomethacin: Impact of drug-polymer ratio and viscosity of the polymeric solution on dissolution

International Nuclear Information System (INIS)

Alanazi, Fars K.; El-Badry, M.; Alsarra, Ibrahim A.

2006-01-01

Polymeric microparticles prepared by spray-drying techniques were investigated to enhance the dissolution rate of indomethacin (IM) in comparison with conventional microparticles prepared by co-precipitation solid dispersion method. Drug-polymer ratios and viscosity of polymeric solutions as potential factors were used in order to enhance the dissolution rate of IM. Spray-drying technique was used for preparing of microparticles using aqueous suspension of IM in hydroxypropyl methylcellulose (HPMC) polymer solution. The effect of drug-polymer ratios on dissolution rates of IM was studied in simulating intestinal medium. IM was analyzed spectrophotometrically at λ =320nm. For each drug-polymer ratios, low and high viscosity polymeric solutions were prepared and their impacts on the dissolution of IM were observed. Microparticles were morphologically characterized by optical microscopy. The interaction between IM and HPMC was studied by differential scanning caloremetry (DSC) and x-ray diffractometry (XRD). Spherical fluffy microparticles of IM were obtained using HPMC. It was observed that the prepared spray-dried microparticles significantly increase the dissolution rate of IM. The increase in dissolution rates was achieved with drug: polymer ratios 1: 1 as well as 1:2 and interestingly, the decrease in drug content in ratio exceeding 1:2 resulted in reduction in dissolution rates. Also, with all drug-polymer ratios, the low viscosity polymeric solutions gave the higher dissolution rates. In conclusion, HPMC microparticles loaded with IM were prepared by spray drying-technique and the potential of this technique to enhance the dissolution was studied. The findings indicate that the dissolution profile of IM microparticles prepared by spray -drying technique relied on drug-polymer ratios and viscosity of polymeric solutions. (author)

Remarks on the Phragmen-Lindelof theorem for Lp-viscosity solutions of fully nonlinear PDEs with unbounded ingredients

Directory of Open Access Journals (Sweden)

Kazushige Nakagawa

2009-11-01

Full Text Available The Phragmen-Lindelof theorem for Lp-viscosity solutions of fully nonlinear second order elliptic partial differential equations with unbounded coefficients and inhomogeneous terms is established.

Measurement of changes in viscosity in polymers with gamma-ray dose using a differential viscometer

International Nuclear Information System (INIS)

Santra, L.; Bhaumik, D.; Roy, S.C.

1988-01-01

Although some works on changes in viscosity of liquids with gamma-ray dose have been made near the ''gel point'', very little works have been done bellow this point. Changes in viscosities of different-grade silicone fluids below gel point have been measured using a differential viscometer developed in our laboratory, capable of measuring change in viscosities of two liquids directly. Preliminary results on viscosity changes when irradiated with energetic alpha particles will also be reported [pt

Measurement of changes in viscosity in polymers with gamma-ray dose using a differential viscometer

International Nuclear Information System (INIS)

Santra, L.; Bhaumik, D.; Roy, S.C.

1989-01-01

Although some works on changes in viscosity of liquids with gamma-ray dose have been made near the 'gel point', very little works have been done below this point. Changes in viscosities of different-grade silicone fluids below gel point have been measured using a differential viscometer developed in our laboratory, capable of measuring change in viscosities of two liquids directly. Preliminary results on viscosity changes when irradiated with energetic alpha particles will also be reported. (orig.)

Simultaneous viscosity and density measurement of small volumes of liquids using a vibrating microcantilever.

Science.gov (United States)

Payam, A F; Trewby, W; Voïtchovsky, K

2017-05-02

Many industrial and technological applications require precise determination of the viscosity and density of liquids. Such measurements can be time consuming and often require sampling substantial amounts of the liquid. These problems can partly be overcome with the use of microcantilevers but most existing methods depend on the specific geometry and properties of the cantilever, which renders simple, accurate measurement difficult. Here we present a new approach able to simultaneously quantify both the density and the viscosity of microliters of liquids. The method, based solely on the measurement of two characteristic frequencies of an immersed microcantilever, is completely independent of the choice of a cantilever. We derive analytical expressions for the liquid's density and viscosity and validate our approach with several simple liquids and different cantilevers. Application of our model to non-Newtonian fluids shows that the calculated viscosities are remarkably robust when compared to measurements obtained from a standard rheometer. However, the results become increasingly dependent on the cantilever geometry as the frequency-dependent nature of the liquid's viscosity becomes more significant.

Detection of irradiated peppers by viscosity measurement at extremely high pH

International Nuclear Information System (INIS)

Hayashi, Toru; Todoriki, Setsuko

1996-01-01

The viscosities of aqueous suspensions of irradiated peppers determined after heat gelatinization were influenced by the pH of the suspension to a greater degree than those of unirradiated ones. Viscosity measurement under an extremely alkaline condition (pH 13.8) resulted in a significant different between irradiated peppers and unirradiated ones, irrespective of the planting locality and storage period. All of the pepper samples irradiated at 5 kGy showed viscosity values significantly lower than unirradiated ones. (Author)

Application of SH surface acoustic waves for measuring the viscosity of liquids in function of pressure and temperature.

Science.gov (United States)

Kiełczyński, P; Szalewski, M; Balcerzak, A; Rostocki, A J; Tefelski, D B

2011-12-01

Viscosity measurements were carried out on triolein at pressures from atmospheric up to 650 MPa and in the temperature range from 10°C to 40°C using ultrasonic measuring setup. Bleustein-Gulyaev SH surface acoustic waves waveguides were used as viscosity sensors. Additionally, pressure changes occurring during phase transition have been measured over the same temperature range. Application of ultrasonic SH surface acoustic waves in the liquid viscosity measurements at high pressure has many advantages. It enables viscosity measurement during phase transitions and in the high-pressure range where the classical viscosity measurement methods cannot operate. Measurements of phase transition kinetics and viscosity of liquids at high pressures and various temperatures (isotherms) is a novelty. The knowledge of changes in viscosity in function of pressure and temperature can help to obtain a deeper insight into thermodynamic properties of liquids. Copyright © 2011 Elsevier B.V. All rights reserved.

Finite Time Merton Strategy under Drawdown Constraint: A Viscosity Solution Approach

International Nuclear Information System (INIS)

Elie, R.

2008-01-01

We consider the optimal consumption-investment problem under the drawdown constraint, i.e. the wealth process never falls below a fixed fraction of its running maximum. We assume that the risky asset is driven by the constant coefficients Black and Scholes model and we consider a general class of utility functions. On an infinite time horizon, Elie and Touzi (Preprint, [2006]) provided the value function as well as the optimal consumption and investment strategy in explicit form. In a more realistic setting, we consider here an agent optimizing its consumption-investment strategy on a finite time horizon. The value function interprets as the unique discontinuous viscosity solution of its corresponding Hamilton-Jacobi-Bellman equation. This leads to a numerical approximation of the value function and allows for a comparison with the explicit solution in infinite horizon

Absolute measurement of the viscosity of classical and quantum fluids by rotating-cylinder viscometers

International Nuclear Information System (INIS)

Donnelly, R.J.; LaMar, M.M.

1987-01-01

We discuss the use of rotating-cylinder viscometers to determine absolute shear viscosities of classical fluids and of helium II in the context of past and current knowledge of the stability and flow of these fluids between concentric cylinders. We identify a problem in measuring the absolute viscosity when the inner cylinder is rotating and the outer cylinder is at rest. We conclude by discussing the design of viscometers for absolute viscosity measurements in helium I and helium II

Study of thermal and chemical effects on cellulase enzymes: Viscosity measurements

International Nuclear Information System (INIS)

Ghaouar, N.; Aschi, A.; Belbahri, L.; Trabelsi, S.; Gharbi, A.

2009-01-01

The behaviour of cellulase enzymes in phosphate saline buffer has been studied over a wide range of temperatures and enzyme concentrations by using viscosity measurements. To characterize the conformation change of cellulase versus temperature and chemical denaturants, such as guanidinium chloride (GdmCl) and urea, the information about the intrinsic viscosity and the hydrodynamic radius are necessary. The dependence of the intrinsic viscosity and the hydrodynamic radius in its random coil conformation on temperature and denaturant concentration were studied. Our results and discussions are limited to the dilute regime of concentration because of abnormalities in conformation observed in the very dilute regime due to the presence of capillary absorption effects.

Study of thermal and chemical effects on cellulase enzymes: Viscosity measurements

Energy Technology Data Exchange (ETDEWEB)

Ghaouar, N., E-mail: naoufel-ghaouar@lycos.co [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 (Tunisia); Institut National des Sciences Appliquees et de Technologie, INSAT, Centre Urbain Nord, BP. 676, Tunis (Tunisia); Aschi, A. [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 (Tunisia); Belbahri, L. [Agronomy Department, School of Engineering of Lullier, University of Applied Sciences of Western Switzerland, 150, Route de Presinge, 1254 Jussy (Switzerland); Trabelsi, S.; Gharbi, A. [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 (Tunisia)

2009-11-15

The behaviour of cellulase enzymes in phosphate saline buffer has been studied over a wide range of temperatures and enzyme concentrations by using viscosity measurements. To characterize the conformation change of cellulase versus temperature and chemical denaturants, such as guanidinium chloride (GdmCl) and urea, the information about the intrinsic viscosity and the hydrodynamic radius are necessary. The dependence of the intrinsic viscosity and the hydrodynamic radius in its random coil conformation on temperature and denaturant concentration were studied. Our results and discussions are limited to the dilute regime of concentration because of abnormalities in conformation observed in the very dilute regime due to the presence of capillary absorption effects.

Hydrodynamic radii of polyethylene glycols in different solvents determined from viscosity measurements

NARCIS (Netherlands)

Dohmen-Speelmans, M.P.J.; Pereira, A.M.; Timmer, J.M.K.; Benes, N.E.; Keurentjes, J.T.F.

2008-01-01

The hydrodynamic radius, rh, of low molar mass polyethylene glycol, MPEG = (200 to 1000) g·mol-1, in a homologous series of primary alcohols, acetone, and toluene has been determined from viscosity measurements. The viscosity data have been collected using a fast one-point method as well as a more

Simultaneous measurement of surface tension and viscosity using freely decaying oscillations of acoustically levitated droplets

Science.gov (United States)

Kremer, J.; Kilzer, A.; Petermann, M.

2018-01-01

Oscillations of small liquid drops around a spherical shape have been of great interest to scientists measuring physical properties such as interfacial tension and viscosity, over the last few decades. A powerful tool for contactless positioning is acoustic levitation, which has been used to simultaneously determine the surface tension and viscosity of liquids at ambient pressure. In order to extend this acoustic levitation measurement method to high pressure systems, the method is first evaluated under ambient pressure. To measure surface tension and viscosity using acoustically levitated oscillating drops, an image analysis method has to be developed and factors which may affect measurement, such as sound field or oscillation amplitude, have to be analyzed. In this paper, we describe the simultaneous measurement of surface tension and viscosity using freely decaying shape oscillations of acoustically levitated droplets of different liquids (silicone oils AK 5 and AK 10, squalane, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol) in air. These liquids vary in viscosity from 2 to about 30 mPa s. An acoustic levitation system, including an optimized standing wave acoustic levitator and a high-speed camera, was used for this study. An image analysis was performed with a self-written Matlab® code. The frequency of oscillation and the damping constant, required for the determination of surface tension and viscosity, respectively, were calculated from the evolution of the equatorial and polar radii. The results and observations are compared to data from the literature in order to analyze the accuracy of surface tension and viscosity determination, as well as the effect of non-spherical drop shape or amplitude of oscillation on measurement.

Partial molar volumes and viscosities of aqueous hippuric acid solutions containing LiCl and MnCl2 · 4H2O at 303.15 K

Science.gov (United States)

Deosarkar, S. D.; Tawde, P. D.; Zinjade, A. B.; Shaikh, A. I.

2015-09-01

Density (ρ) and viscosity (η) of aqueous hippuric acid (HA) solutions containing LiCl and MnCl2 · 4H2O have been studied at 303.15 K in order to understand volumetric and viscometric behavior of these systems. Apparent molar volume (φv) of salts were calculated from density data and fitted to Massons relation and partial molar volumes (φ{v/0}) at infinite dilution were determined. Relative viscosity data has been used to determine viscosity A and B coefficients using Jones-Dole relation. Partial molar volume and viscosity coefficients have been discussed in terms of ion-solvent interactions and overall structural fittings in solution.

Determination of temperature dependant viscosity values of lubricants via simultaneous measurements of refractive index

International Nuclear Information System (INIS)

Yaltkaya, S.

2005-01-01

Viscosity is one of the most important parameter in rheological and tribological properties of fluids. The objective of this study is to obtain the viscosity values from the simultaneous refractive-index measurements of lubricants, simply by dipping the fiber-optic probe into the oil to be measured. Due to the fact that these parameters are temperature dependent, within the interval under consideration, oil heated up steadily while measuring the viscosity and refractive index at the same time. The refractive index sensor, the digital viscometer and the thermometer were connected to a PC via an analog to digital converter and the values were acquired at the same time. The fiber optic refractive index sensor has been designed in our laboratory. By utilising Fresnel's fundamental reflection law, the intensity of reflected light from boundary surface (optic fiber core-motor oil) was measured at 660 nm wavelength and then refractive index of the oil was calculated. The derived refractive index values were converted viscosity values that acquired by using the calibration equation. The viscometer, used during the study, was the rotational Brookfield type

Numerical solution of problems concerning the thermal convection of a variable-viscosity liquid

Science.gov (United States)

Zherebiatev, I. F.; Lukianov, A. T.; Podkopaev, Iu. L.

A stabilizing-correction scheme is constructed for integrating the fourth-order equation describing the dynamics of a viscous incompressible liquid. As an example, a solution is obtained to the problem of the solidification of a liquid in a rectangular region with allowance for convective energy transfer in the liquid phase as well as temperature-dependent changes of viscosity. It is noted that the proposed method can be used to study steady-state problems of thermal convection in ingots obtained through continuous casting.

Concentration dependence of the partial volume, viscosity, and electric conductivity of solutions of lithium salts in aliphatic alcohols

International Nuclear Information System (INIS)

Eliseeva, O.V.; Golubev, V.V.

2003-01-01

Concentration dependence of partial volumes, electric conductivity and viscosity of lithium nitrate and chloride solutions in methanol, propanol, isopropanol, butanol, isobutanol, pentanol and isopentanol at 298.15 K were studied by the methods of densimetry, conductometry and viscosimetry. Structural specific features of the solutions studied are discussed on the basis of the calculated volumetric characteristics of the substance dissolved and solvent [ru

Effect of Viscosity on Liquid Curtain Stability

Science.gov (United States)

Mohammad Karim, Alireza; Suszynski, Wieslaw; Francis, Lorraine; Carvalho, Marcio; Dow Chemical Company Collaboration; PUC Rio Collaboration; University of Minnesota, Twin Cities Collaboration

2016-11-01

The effect of viscosity on the stability of Newtonian liquid curtains was explored by high-speed visualization. Glycerol/water solutions with viscosity ranging from 19.1 to 210 mPa.s were used as coating liquids. The experimental set-up used a slide die delivery and steel tube edge guides. The velocity along curtain at different positions was measured by tracking small particles at different flow conditions. The measurements revealed that away from edge guides, velocity is well described by free fall effect. However, close to edge guides, liquid moves slower, revealing formation of a viscous boundary layer. The size of boundary layer and velocity near edge guides are strong function of viscosity. The critical condition was determined by examining flow rate below which curtain broke. Curtain failure was initiated by growth of a hole within liquid curtain, close to edge guides. Visualization results showed that the hole forms in a circular shape then becomes elliptical as it grows faster in vertical direction compared to horizontal direction. As viscosity rises, minimum flow rate for destabilization of curtain increased, indicating connection between interaction with edge guides and curtain stability. We would like to acknowledge the financial support from the Dow Chemical Company.

Effect of polycarboxylate ether comb-type polymer on viscosity and interfacial properties of kaolinite clay suspensions.

Science.gov (United States)

Zhang, Ling; Lu, Qingye; Xu, Zhenghe; Liu, Qingxia; Zeng, Hongbo

2012-07-15

The interactions between kaolinite clay particles and a comb-type polymer (polycarboxylate ether or PCE), so-called PCE super-plasticizer, were investigated through viscosity and surface forces measurements by a rheometer and a Surface Forces Apparatus (SFA). The addition of PCE shows a strong impact on the viscosity of concentrated kaolinite suspensions in alkaline solutions (pH=8.3) but a weak effect under acidic conditions (pH=3.4). In acidic solutions, the high viscosity measured is attributed to the strong electrostatic interaction between negatively charged basal planes and positively charged edge surfaces of clay particles. Under the alkaline condition, the suspension viscosity was found to first increase significantly and then decrease with increasing PCE dosages. The results from surface forces measurement show that PCE molecules at low dosages can bridge the kaolinite particles in the concentrated suspensions via hydrogen bonding, leading to the formation of a kaolinite-PCE "network" and hence an increased suspension viscosity. At high PCE dosages, clay particles are fully covered by PCE molecules, leading to a more dispersed kaolinite suspensions and hence lower suspension viscosity due to steric repulsion between the adsorbed PCE molecules. The insights derived from measuring viscosity and interfacial properties of kaolinite suspensions containing varying amount of comb-type super-plasticizer PCE at different pH provide the foundation for many engineering applications and optimizing industrial processes. Copyright © 2012 Elsevier Inc. All rights reserved.

Calibration and Measurement of the Viscosity of DWPF Start-Up Glass

International Nuclear Information System (INIS)

Schumacher, R.F.

2001-01-01

The Harrop, High-Temperature Viscometer has been in operation at the Savannah River Technology Center (SRTC) for several years and has proven itself to be reasonably accurate and repeatable. This is particularly notable when taking into consideration the small amount of glass required to make the viscosity determination. The volume of glass required is only 2.60 cc or about 6 to 7 grams of glass depending on the glass density. This may be compared to the more traditional viscosity determinations, which generally require between 100 to 1000 grams of glass. Before starting the present investigation, the unit was re-aligned and the furnace thermal gradients measured. The viscometer was again calibrated with available NIST Standard Reference Material glasses (717a and 710a) and a spindle constant equation was determined. Standard DWPF Waste Compliance Glasses (Purex, HM, and Batch 1) were used to provide additional verification for the determinations at low temperature. The Harrop, High-Temperature Viscometer was then used to determine the viscosity of three random samples of ground and blended DWPF, Black, Start -Up Frit, which were obtained from Pacific Northwest National Laboratory (PNNL). The glasses were in powder form and required melting prior to the viscosity determination. The results from this evaluation will be compared to ''Round Robin'' measurements from other DOE laboratories and a number of commercial laboratories

Theory of the high-frequency limiting viscosity of a dilute polymer solution. Pt. 2

Energy Technology Data Exchange (ETDEWEB)

Doi, M; Nakajima, H; Wada, Y

1976-06-01

High-frequency limiting viscosities of dilute polymer solutions are calculated on the basis of the author's previous theory for (1) necklace model of a chain with constant bond length and bond angle under a hindering rotational potential, and (2) broken rod model consisting of N rods with equal length connected by universal joints. Exact treatment is possible for a once-broken rod model, but the Monte Carlo method is used in the other calculations.

Effect of electron beam irradiation on viscosity/temperature characteristics of cellulose derivatives

International Nuclear Information System (INIS)

Mastro, N.L. del; Villavicencio, A.L.C.; Yamasaki, M.C.R.

1991-11-01

The direct relationship between intrinsic viscosity and molecular weight of polymers allowed to attend the aggregation, cross-linking and degradation processes induced by electron beam irradiation on carboxymethylcellulose and hydroxiethylcellulose in aqueous solutions. The changes in viscosity were related to irradiation doses from 2.5x10 4 Gy to 25x10 4 Gy at 5 0 C, 25 0 C, 50 0 C and 75 0 C measured at different intervals after irradiation. The results showed the viscosity decrease characteristics as a function of those parameters for each one of the polymers. (author)

The experimental viscosity and calculated relative viscosity of liquid In-Sn allcoys

International Nuclear Information System (INIS)

Wu, A.Q.; Guo, L.J.; Liu, C.S.; Jia, E.G.; Zhu, Z.G.

2007-01-01

The experimental measured viscosity of liquid pure Sn, In 20 Sn 80 and In 80 Sn 20 alloys was studied, and to make a comparison, the calculated relative viscosity based on the pair distribution functions, g(r), has also been studied. There is one peak in each experimental viscosity and calculated relative-viscosity curve of liquid pure Sn about 1000 deg. C. One valley appears in each experimental viscosity and calculated viscosity curve of liquid In 20 Sn 80 alloy about 700 deg. C. There is no abnormal behavior on In 80 Sn 20 alloy. The behavior of experimental viscosity and calculated relative viscosity is coincident with each other. Those results conformed that the temperature-induced structure anomalies reported before did take place

A MEMS Resonant Sensor to Measure Fluid Density and Viscosity under Flexural and Torsional Vibrating Modes

Directory of Open Access Journals (Sweden)

Libo Zhao

2016-06-01

Full Text Available Methods to calculate fluid density and viscosity using a micro-cantilever and based on the resonance principle were put forward. Their measuring mechanisms were analyzed and the theoretical equations to calculate the density and viscosity were deduced. The fluid-solid coupling simulations were completed for the micro-cantilevers with different shapes. The sensing chips with micro-cantilevers were designed based on the simulation results and fabricated using the micro electromechanical systems (MEMS technology. Finally, the MEMS resonant sensor was packaged with the sensing chip to measure the densities and viscosities of eight different fluids under the flexural and torsional vibrating modes separately. The relative errors of the measured densities from 600 kg/m3 to 900 kg/m3 and viscosities from 200 μPa·s to 1000 μPa·s were calculated and analyzed with different microcantilevers under various vibrating modes. The experimental results showed that the effects of the shape and vibrating mode of micro-cantilever on the measurement accuracies of fluid density and viscosity were analyzed in detail.

Measurement of Viscosity of Hydrocarbon Liquids Using a Microviscometer

DEFF Research Database (Denmark)

Dandekar, Abhijit; Andersen, Simon Ivar; Stenby, Erling Halfdan

1998-01-01

The viscosity of normal alkanes, their mixtures, and true boiling point (TBP) fractions (C (sub 6) -C (sub 19)) of four North Sea petroleum reservoir fluids have been measured by use of an automatic rolling ball mixroviscometer at 20°C. The equipment is specially suited for samples of limited amo...

A Riemann problem with small viscosity and dispersion

Directory of Open Access Journals (Sweden)

Kayyunnapara Thomas Joseph

2006-09-01

Full Text Available In this paper we prove existence of global solutions to a hyperbolic system in elastodynamics, with small viscosity and dispersion terms and derive estimates uniform in the viscosity-dispersion parameters. By passing to the limit, we prove the existence of solution the Riemann problem for the hyperbolic system with arbitrary Riemann data.

Applicability of Stokes method for measuring viscosity of mixtures with concentration gradient

Directory of Open Access Journals (Sweden)

César Medina

2017-12-01

Full Text Available After measuring density and viscosity of a mixture of glycerin and water contained in a vertical pipe, a variation of these properties according to depth is observed. These gradients are typical of non-equilibrium states related to the lower density of water and the fact that relatively long times are necessary to achieve homogeneity. In the same pipe, the falling velocity of five little spheres is measured as a function of depth, and then a numerical fit is performed which agrees very well with experimental data. Based on the generalization of these results, the applicability of Stokes method is discussed for measuring viscosity of mixtures with a concentration gradient.

Study of cellulase enzymes self-assembly in aqueous-acetonitrile solvent: Viscosity measurements

Energy Technology Data Exchange (ETDEWEB)

Ghaouar, N., E-mail: naoufel-ghaouar@lycos.co [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 (Tunisia); Institut National des Sciences Appliquees et de Technologie, INSAT, Centre Urbain Nord, BP. 676, Tunis (Tunisia); Aschi, A. [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 (Tunisia); Belbahri, L. [School of Engineering of Lullier, University of Applied Sciences of Western Switzerland, 150, Route de Presinge, 1254 Jussy (Switzerland); Trabelsi, S.; Gharbi, A. [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 (Tunisia)

2009-11-15

The present study extends the viscosity measurements performed by Ghaouar et al. [Physica B, submitted for publication.] to study the conformational change of the cellulase enzymes in aqueous-acetonitrile mixture. We aim to investigate: (i) the denaturation process by measuring the specific viscosity for temperatures varying between 25 and 65 deg. C and acetonitrile concentrations between 0% and 50%, (ii) the enzyme-enzyme interaction by calculating the Huggins coefficient and (iii) the enzyme sizes by following the hydrodynamic radius for various temperatures. The precipitation of cellulases versus acetonitrile concentration is also considered. We show from all physical quantities measured in this work that the precipitation and the denaturation processes of cellulase enzymes exist together.

Study of cellulase enzymes self-assembly in aqueous-acetonitrile solvent: Viscosity measurements

International Nuclear Information System (INIS)

Ghaouar, N.; Aschi, A.; Belbahri, L.; Trabelsi, S.; Gharbi, A.

2009-01-01

The present study extends the viscosity measurements performed by Ghaouar et al. [Physica B, submitted for publication.] to study the conformational change of the cellulase enzymes in aqueous-acetonitrile mixture. We aim to investigate: (i) the denaturation process by measuring the specific viscosity for temperatures varying between 25 and 65 deg. C and acetonitrile concentrations between 0% and 50%, (ii) the enzyme-enzyme interaction by calculating the Huggins coefficient and (iii) the enzyme sizes by following the hydrodynamic radius for various temperatures. The precipitation of cellulases versus acetonitrile concentration is also considered. We show from all physical quantities measured in this work that the precipitation and the denaturation processes of cellulase enzymes exist together.

Fabrication and Testing of Viscosity Measuring Instrument (Viscometer

Directory of Open Access Journals (Sweden)

A. B. HASSAN

2006-01-01

Full Text Available This paper presents the fabrication and testing of a simple and portable viscometer for the measurement of bulk viscosity of different Newtonian fluids. It is aimed at making available the instrument in local markets and consequently reducing or eliminating the prohibitive cost of importation. The method employed is the use of a D.C motor to rotate a disc having holes for infra-red light to pass through and fall on a photo-diode thus undergoing amplification and this signal being translated on a moving-coil meter as a deflection. The motor speed is kept constant but varies with changes in viscosity of the fluid during stirring, which alter signals being read on the meter. The faster is revolution per minute of the disc, the less the deflection on the meter and vise-versa. From the results of tests conducted on various sample fluids using data on standard Newtonian fluids as reliable guide the efficiency of the viscometer was 76.5%.

Perturbation Solutions for Hagen-Poiseuille Flow and Heat Transfer of Third-Grade Fluid with Temperature-Dependent Viscosities and Internal Heat Generation

Directory of Open Access Journals (Sweden)

B. Y. Ogunmola

2016-01-01

Full Text Available Regular perturbation technique is applied to analyze the fluid flow and heat transfer in a pipe containing third-grade fluid with temperature-dependent viscosities and heat generation under slip and no slip conditions. The obtained approximate solutions were used to investigate the effects of slip on the heat transfer characteristics of the laminar flow in a pipe under Reynolds’s and Vogel’s temperature-dependent viscosities. Also, the effects of parameters such as variable viscosity, non-Newtonian parameter, viscous dissipation, and pressure gradient at various values were established. The results of this work were compared with the numerical results found in literature and good agreements were established. The results can be used to advance the analysis and study of the behavior of third-grade fluid flow and steady state heat transfer processes such as those found in coal slurries, polymer solutions, textiles, ceramics, catalytic reactors, and oil recovery applications.

Noncontact surface tension and viscosity measurements of rhenium in the liquid and undercooled states

International Nuclear Information System (INIS)

Ishikawa, Takehiko; Paradis, Paul-Francois; Yoda, Shinichi

2004-01-01

Surface tension and viscosity of liquid rhenium, which have hardly been measured due to the extremely high melting temperature of rhenium, were measured using an electrostatic levitation method combined with the oscillation drop technique. Sample position instability problems caused by the photon pressure of the heating lasers and by sample evaporation were solved by modifying the electrodes design. Good sample stability allowed the measurements of the surface tension and the viscosity over wide temperature ranges including the undercooled states. Over the 2800-3600 K interval, the surface tension of rhenium was measured as σ(T)=2.71x10 3 -0.23(T-T m ), where T m is the melting temperature, 3453 K. At T m , the datum agrees well with the literature values. Similarly, on the same temperature range, the viscosity was determined as η(T)=0.08 exp[1.33x10 5 /(RT)] (mPa s)

Direct observations of the viscosity of Earth's outer core and extrapolation of measurements of the viscosity of liquid iron

International Nuclear Information System (INIS)

Smylie, D E; Brazhkin, Vadim V; Palmer, Andrew

2009-01-01

Estimates vary widely as to the viscosity of Earth's outer fluid core. Directly observed viscosity is usually orders of magnitude higher than the values extrapolated from high-pressure high-temperature laboratory experiments, which are close to those for liquid iron at atmospheric pressure. It turned out that this discrepancy can be removed by extrapolating via the widely known Arrhenius activation model modified by lifting the commonly used assumption of pressure-independent activation volume (which is possible due to the discovery that at high pressures the activation volume increases strongly with pressure, resulting in 10 2 Pa s at the top of the fluid core, and in 10 11 Pa s at its bottom). There are of course many uncertainties affecting this extrapolation process. This paper reviews two viscosity determination methods, one for the top and the other for the bottom of the outer core, the former of which relies on the decay of free core nutations and yields 2371 ± 1530 Pa s, while the other relies on the reduction in the rotational splitting of the two equatorial translational modes of the solid inner core oscillations and yields an average of 1.247 ± 0.035 Pa s. Encouraged by the good performance of the Arrhenius extrapolation, a differential form of the Arrhenius activation model is used to interpolate along the melting temperature curve and to find the viscosity profile across the entire outer core. The viscosity variation is found to be nearly log-linear between the measured boundary values. (methodological notes)

Measurement and calculation of the viscosity of metals—a review of the current status and developing trends

International Nuclear Information System (INIS)

Cheng, J; Hort, N; Kainer, K U; Gröbner, J; Schmid-Fetzer, R

2014-01-01

Viscosity is an important rheological property of metals in casting because it controls the rate of transport of liquid metals, which may lead to casting defects such as hot tearing and porosity. The measurement methods and numerical models of the viscosity of liquid and semi-solid state metals that have been published to date are reviewed in this paper. Most experimental measurements have been performed with rotational and oscillatory viscometers, which offer advantages at low viscosities in particular. Besides these two traditional methods for measuring viscosities, a couple of studies also introduced the technique of isothermal compression for alloys in the semi-solid state, and even an optical basicity method for the viscosity of slags. As to numerical models, most published results show that the viscosity of liquid and semi-solid state metals can be described by the Arrhenius, Andrade, Kaptay or Budai–Bemkő–Kaptay equations. In addition, there are some alternative models, such as the power model and the isothermal stress–strain model. (topical review)

Effects of the kinematic viscosity and surface tension on the bubble take-off period in a catalase-hydrogen peroxide system.

Science.gov (United States)

Sasaki, Satoshi; Iida, Yoshinori

2009-06-01

The effect of kinematic viscosity and surface tension of the solution was investigated by adding catalase, glucose oxidase, or glucose on the bubble movement in a catalase-hydrogen peroxide system. The kinematic viscosity was measured using a Cannon-Fenske kinematic viscometer. The surface tension of the solution was measured by the Wilhelmy method using a self-made apparatus. The effects of the hole diameter/cell wall thickness, catalase concentration, glucose concentration, and glucose oxidase concentration on the kinematic viscosity, surface tension, and bubble take-off period were investigated. With our system, the effects of the changes in the solution materiality on the bubble take-off period were proven to be very small in comparison to the change in the oxygen-producing rate.

On-line measurement of food viscosity during flow

DEFF Research Database (Denmark)

Mason, Sarah Louise; Friis, Alan

2006-01-01

Sarah L. Mason and Alan Friis discuss some of the principles and equipment used to monitor food viscosity in real time.......Sarah L. Mason and Alan Friis discuss some of the principles and equipment used to monitor food viscosity in real time....

Jet collimation by turbulent viscosity. I

International Nuclear Information System (INIS)

Henriksen, R.N.

1987-01-01

In this paper it is assumed that the subscale turbulent eddies induced in an ambient medium by the emergence of a (already collimated) jet from a galactic nucleus (VLBI jet) are the source of the viscosity which causes material to be entrained into the large-scale (VLA) jet. New analytic solutions are derived by a generalization of the self-similar Ansatz used in the Landau-Squires solution to include variable density and viscosity. It is shown that such a process of viscous collimation of the VLA jets can account for the observed collimation-luminosity correlation, the magnetic flux, and the inferred mass flux of these jets. Order of magnitude comparisons of velocity and density fields with recently observed emission-line flow regions near radio jets are made. All of the viscosity-dependent observational checks imply roughly the same plausible value for the eddy viscosity. It is emphasized that storing the initial VLBI jet energy in the intermediate scales occupied by the turbulent eddies allows this energy to be largely undetected. 35 references

Vanishing Shear Viscosity Limit in the Magnetohydrodynamic Equations

Science.gov (United States)

Fan, Jishan; Jiang, Song; Nakamura, Gen

2007-03-01

We study an initial boundary value problem for the equations of plane magnetohydrodynamic compressible flows, and prove that as the shear viscosity goes to zero, global weak solutions converge to a solution of the original equations with zero shear viscosity. As a by-product, this paper improves the related results obtained by Frid and Shelukhin for the case when the magnetic effect is neglected.

Density and viscosity of aqueous solutions of N,N-dimethylethanolamine at p = 0.1 MPa from T = (293.15 to 363.15) K

Energy Technology Data Exchange (ETDEWEB)

Bernal-Garcia, J. Manuel [Instituto Mexicano del Petroleo, Mexico D.F. C.P. 07330 (Mexico); Hall, Kenneth R. [Chemical Engineering Department, Texas A and M University, College Station, TX 77843 (United States); Estrada-Baltazar, Alejandro [Departamento de Ingenieria Quimica, Instituto Tecnologico de Celaya, Celaya, Guanajuato, CP 38010 (Mexico); Iglesias-Silva, Gustavo A. [Departamento de Ingenieria Quimica, Instituto Tecnologico de Celaya, Celaya, Guanajuato, CP 38010 (Mexico)]. E-mail: gais@iqcelaya.itc.mx

2005-08-15

This work presents atmospheric density and viscosity values for (N,N-dimethylethanolamine + water) over the entire composition range from T (293.15 to 363.15) K for density and from T = (313.15 to 353.15) K for viscosity. Density measurements come from a vibrating tube densimeter while we have used three different Cannon-Fenske viscosimeters for the viscosity measurements. Excess molar volumes and viscosity deviations are calculated using a Redlich-Kister type equation. Excess molar volumes present negative deviations from ideality and viscosity deviations are positive at all temperatures and compositions in this work.

Density and viscosity of aqueous solutions of N,N-dimethylethanolamine at p = 0.1 MPa from T = (293.15 to 363.15) K

International Nuclear Information System (INIS)

Bernal-Garcia, J. Manuel; Hall, Kenneth R.; Estrada-Baltazar, Alejandro; Iglesias-Silva, Gustavo A.

2005-01-01

This work presents atmospheric density and viscosity values for (N,N-dimethylethanolamine + water) over the entire composition range from T (293.15 to 363.15) K for density and from T = (313.15 to 353.15) K for viscosity. Density measurements come from a vibrating tube densimeter while we have used three different Cannon-Fenske viscosimeters for the viscosity measurements. Excess molar volumes and viscosity deviations are calculated using a Redlich-Kister type equation. Excess molar volumes present negative deviations from ideality and viscosity deviations are positive at all temperatures and compositions in this work

Microrheometric upconversion-based techniques for intracellular viscosity measurements

Science.gov (United States)

Rodríguez-Sevilla, Paloma; Zhang, Yuhai; de Sousa, Nuno; Marqués, Manuel I.; Sanz-Rodríguez, Francisco; Jaque, Daniel; Liu, Xiaogang; Haro-González, Patricia

2017-08-01

Rheological parameters (viscosity, creep compliance and elasticity) play an important role in cell function and viability. For this reason different strategies have been developed for their study. In this work, two new microrheometric techniques are presented. Both methods take advantage of the analysis of the polarized emission of an upconverting particle to determine its orientation inside the optical trap. Upconverting particles are optical materials that are able to convert infrared radiation into visible light. Their usefulness has been further boosted by the recent demonstration of their three-dimensional control and tracking by single beam infrared optical traps. In this work it is demonstrated that optical torques are responsible of the stable orientation of the upconverting particle inside the trap. Moreover, numerical calculations and experimental data allowed to use the rotation dynamics of the optically trapped upconverting particle for environmental sensing. In particular, the cytoplasm viscosity could be measured by using the rotation time and thermal fluctuations of an intracellular optically trapped upconverting particle, by means of the two previously mentioned microrheometric techniques.

Solute-solvent interactions in chloroform solutions of halogenated symmetric double Schiff bases of 1,1'-bis(4-aminophenyl)cyclohexane at 308.15 K according to ultrasonic and viscosity data

Science.gov (United States)

Gangani, B. J.; Patel, J. P.; Parsania, P. H.

2015-12-01

The density, viscosity and ultrasonic speed (2 MHz) of chloroform solutions of halogenated symmetric double Schiff bases of 1,1'-bis(4-aminophenyl)cyclohexane were investigated at 308.15 K. Various acoustical parameters such as specific acoustical impedance ( Z), adiabatic compressibility ( Ka), Rao's molar sound function ( R m), van der Waals constant ( b), internal pressure (π), free volume ( V f), intermolecular free path length ( L f), classical absorption coefficient (α/ f 2)Cl) and viscous relaxation time (τ) were determine using ultrasonic speed ( U), viscosity (η) and density (ρ) data of Schiff bases solutions and correlated with concentration. Linear increase of Z, b, R, τ, and (α/ f 2)Cl except π (nonlinear) and linear decrease of Ka and L f except V f (nonlinear) with increasing concentration of Schiff bases suggested presence of strong molecular interactions in the solutions. The positive values of solvation number further supported strong molecular interactions in the solutions. The nature and position of halogen substituent also affected the strength of molecular interactions.

Concentration dependences of the density, viscosity, and refraction index of Cu(NO3)2 · 3H2O solutions in DMSO at 298 K

Science.gov (United States)

Mamyrbekova, A. K.

2013-03-01

Physicochemical properties (density, dynamic viscosity, refraction index) of the DMSO-Cu(NO3)2 · 3H2O system are studied in the concentration range of 0.01-2 M at 298 K. The refraction index of a solution of copper(II) nitrate in dimethylsulfoxide (DMSO) is measured at 288-318 K. The excess and partial molar volumes of the solvent and dissolved substance are calculated analytically.

Phenomenology of polymer solution dynamics

National Research Council Canada - National Science Library

Phillies, George D. J

2011-01-01

... solutions, not dilute solutions or polymer melts. From centrifugation and solvent dynamics to viscosity and diffusion, experimental measurements and their quantitative representations are the core of the discussion...

Study of specific loss power of magnetic fluids with various viscosities

Energy Technology Data Exchange (ETDEWEB)

Phong, P.T., E-mail: phamthanhphong@tdt.edu.vn [Department for Management of Science and Technology Development, Ton Duc Thang University, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City (Viet Nam); Nguyen, L.H., E-mail: luuhuunguyen@ukh.edu.vn [Institute of Materials Science, Vietnam Academy of Science and Technology,18- Hoang Quoc Viet Street, Cau Giay District, Ha Noi City (Viet Nam); Khanh Hoa University, 1- Nguyen Chanh Street, Nha Trang City, Khanh Hoa Province (Viet Nam); Phong, L.T.H., E-mail: lthp52a@gmail.com [Institute of Materials Science, Vietnam Academy of Science and Technology,18- Hoang Quoc Viet Street, Cau Giay District, Ha Noi City (Viet Nam); Nam, P.H., E-mail: namph.ims@gmail.com [Institute of Materials Science, Vietnam Academy of Science and Technology,18- Hoang Quoc Viet Street, Cau Giay District, Ha Noi City (Viet Nam); Manh, D.H., E-mail: manhdh.ims@gmail.com [Institute of Materials Science, Vietnam Academy of Science and Technology,18- Hoang Quoc Viet Street, Cau Giay District, Ha Noi City (Viet Nam); Lee, I.J., E-mail: lij@dongguk.ac.kr [Department of Advanced Materials Chemistry, Dongguk University-Gyeongju, Dongdae-roDongdae-ro 123, Gyeongju-Si, Gyeongbuk 38066 (Korea, Republic of); Phuc, N.X., E-mail: phucnx1949@gmail.com [Institute of Materials Science, Vietnam Academy of Science and Technology,18- Hoang Quoc Viet Street, Cau Giay District, Ha Noi City (Viet Nam)

2017-04-15

Abstracts: Using hydrothermal method, CoFe{sub 2}O{sub 4} (hard ferrite) and MnFe{sub 2}O{sub 4} (soft ferrite) nanoparticles of size up to 20 nm were synthesized and the viscosities were controlled using various concentrations of agar. The hydrodynamic diameter of these particles was measured and fitted to a lognormal distribution and the results showed their polydispersity is very narrow. From the calorimetric measurements of the particles stabilized in agar solutions, we have demonstrated that at a given frequency, the dependence of the specific loss power of magnetic fluids on the viscosity is in good agreement with the theoretical predictions made in the earlier studies. - Highlights: • CoFe{sub 2}O{sub 4} (hard ferrite) and MnFe{sub 2}O{sub 4} (soft ferrite) nanoparticles size up to 20 nm were synthesized. • The relaxation loss depends on both the particle's intrinsic properties and the viscosity of the environment. • The SLP of hard nanoparticles strongly decreases with increasing the viscosity whereas that of soft nanoparticles remains almost unchanged.

The viscosity of dimethyl ether

DEFF Research Database (Denmark)

Sivebæk, Ion Marius; Jakobsen, Jørgen

2007-01-01

and NOx traps are installed. The most significant problem encountered when engines are fuelled with DME is that the injection equipment breaks down prematurely due to extensive wear. This tribology issue can be explained by the very low lubricity and viscosity of DME. Recently, laboratory methods have...... appeared capable of measuring these properties of DME. The development of this is rendered difficult because DME has to be pressurised to remain in the liquid state and it dissolves most of the commercially available elastomers. This paper deals fundamentally with the measurement of the viscosity of DME...... and extends the discussion to the difficulty of viscosity establishing of very thin fluids. The main issue here is that it is not easy to calibrate the viscometers in the very low viscosity range corresponding to about one-fifth of that of water. The result is that the low viscosity is measured at high...

Sensor for viscosity and shear strength measurement

Energy Technology Data Exchange (ETDEWEB)

Ebadian, M.A.; Dillion, J.; Moore, J.; Jones, K.

1998-01-01

Measurement of the physical properties (viscosity and density) of waste slurries is critical in evaluating transport parameters to ensure turbulent flow through transport pipes. The environment for measurement and sensor exposure is extremely harsh; therefore, reliability and ruggedness are critical in the sensor design. Two different viscometer techniques are being investigated in this study, based on: magnetostrictive pulse generated acoustic waves; and an oscillating cylinder. Prototype sensors have been built and tested which are based on both techniques. A base capability instrumentation system has been designed, constructed, and tested which incorporates both of these sensors. It requires manual data acquisition and off-line calculation. A broad range of viscous media has been tested using this system. Extensive test results appear in this report. The concept for each technique has been validated by these test results. This base capability system will need to be refined further before it is appropriate for field tests. The mass of the oscillating system structure will need to be reduced. A robust acoustic probe assembly will need to be developed. In addition, in March 1997 it was made known for the first time that the requirement was for a deliverable automated viscosity instrumentation system. Since then such a system has been designed, and the hardware has been constructed so that the automated concept can be proved. The rest of the hardware, which interfaced to a computer, has also been constructed and tested as far as possible. However, for both techniques the computer software for automated data acquisition, calculation, and logging had not been completed before funding and time ran out.

Solitary traveling wave solutions of pressure equation of bubbly liquids with examination for viscosity and heat transfer

Science.gov (United States)

Khater, Mostafa M. A.; Seadawy, Aly R.; Lu, Dianchen

2018-03-01

In this research, we investigate one of the most popular model in nature and also industrial which is the pressure equation of bubbly liquids with examination for viscosity and heat transfer which has many application in nature and engineering. Understanding the physical meaning of exact and solitary traveling wave solutions for this equation gives the researchers in this field a great clear vision of the pressure waves in a mixture liquid and gas bubbles taking into consideration the viscosity of liquid and the heat transfer and also dynamics of contrast agents in the blood flow at ultrasonic researches. To achieve our goal, we apply three different methods which are extended tanh-function method, extended simple equation method and a new auxiliary equation method on this equation. We obtained exact and solitary traveling wave solutions and we also discuss the similarity and difference between these three method and make a comparison between results that we obtained with another results that obtained with the different researchers using different methods. All of these results and discussion explained the fact that our new auxiliary equation method is considered to be the most general, powerful and the most result-oriented. These kinds of solutions and discussion allow for the understanding of the phenomenon and its intrinsic properties as well as the ease of way of application and its applicability to other phenomena.

Understanding and modulating opalescence and viscosity in a monoclonal antibody formulation.

Science.gov (United States)

Salinas, Branden A; Sathish, Hasige A; Bishop, Steven M; Harn, Nick; Carpenter, John F; Randolph, Theodore W

2010-01-01

Opalescence and high viscosities can pose challenges for high concentration formulation of antibodies. Both phenomena result from protein-protein intermolecular interactions that can be modulated with solution ionic strength. We studied a therapeutic monoclonal antibody (mAb) that exhibits high viscosity in solutions at low ionic strength ( approximately 20 cP at 90 mg/mL and 23 degrees C) and significant opalescence at isotonic ionic strength (approximately 100 nephelometric turbidity units at 90 mg/mL and 23 degrees C). The intermolecular interactions responsible for these effects were characterized using membrane osmometry, static light scattering, and zeta potential measurements. The net protein-protein interactions were repulsive at low ionic strength ( approximately 4 mM) and attractive at isotonic ionic strengths. The high viscosities are attributed to electroviscous forces at low ionic strength and the significant opalescence at isotonic ionic strength is correlated with attractive antibody interactions. Furthermore, there appears to be a connection to critical phenomena and it is suggested that the extent of opalescence is dependent on the proximity to the critical point. We demonstrate that by balancing the repulsive and attractive forces via intermediate ionic strengths and by increasing the mAb concentration above the apparent critical concentration both opalescence and viscosity can be simultaneously minimized.

Measuring Viscosity with a Levitating Magnet: Application to Complex Fluids

Science.gov (United States)

Even, C.; Bouquet, F.; Remond, J.; Deloche, B.

2009-01-01

As an experimental project proposed to students in fourth year of university, a viscometer was developed, consisting of a small magnet levitating in a viscous fluid. The viscous force acting on the magnet is directly measured: viscosities in the range 10-10[superscript 6] mPa s are obtained. This experiment is used as an introduction to complex…

Second viscosity effects in cosmology

International Nuclear Information System (INIS)

Potupa, A.S.

1978-01-01

The object of the investigation is to draw attention to two important aspects in the choice of a substance model, namely an allowance for the viscosity and behaviour of the metrics at the later stages of cosmological evolution. It is shown that in homogeneous cosmological models taking into account the viscosity there are solutions which realize interpolation between the Fridman and steady-state regimes. In a closed model a solution is obtained which corresponds to the ''curvature compensation'' regime with an unboundedly increasing radius. The problem of compensation of singularity at t → o is discussed as well as the choice of the equations of state for the early (hadron) stages of cosmological evolution in connection with the hydrodynamic theory of multiple hadron production

Measurement and Correlation on Viscosity and Apparent Molar Volume of Ternary System for L-ascorbic Acid in Aqueous D-Glucose and Sucrose Solutions%L-抗坏血酸在葡萄糖和蔗糖溶液中的黏度及其热力学性质的研究

Institute of Scientific and Technical Information of China (English)

赵长伟; 马沛生

2003-01-01

Viscosities and densities at several temperatures from 293.15 K to 313.15 K are reported for L-ascorbic acid in aqueous glucose and sucrose solutions at different concentrations. The parameters of density, viscosity coefficient B and partial molar volume are calculated by regression. The experimental results show that densities and viscosities decrease as temperature increases at the same solute and solvent (glucose and sucrose aqueous solution) concentrations, and increase with concentration of glucose and sucrose at the same solute concentration and temperature. B increases with concentration of glucose and sucrose and temperature. L-ascorbic acid is structure-breaker or structure-making for the glucose and sucrose aqueous solutions. Furthermore, the solute-solvent interactions in ternary systems of water-glucose-electrolyte and water-sucrose-electrolyte are discussed.

Volumetric, viscosity, and electrical conductivity properties of aqueous solutions of two n-butylammonium-based protic ionic liquids at several temperatures

International Nuclear Information System (INIS)

Xu, Yingjie

2013-01-01

Highlights: • Densities and viscosities of N4AC + water and N4NO 3 + water mixtures were measured. • Volumetric and viscosity properties were calculated. • Redlich–Kister equation was used to correlate the excess molar volumes and viscosity deviations. • Electrical conductivity was fitted according to the empirical Casteel–Amis equation. • The interactions and structural effects of N4AC or N4NO 3 with water were analyzed. -- Abstract: Densities and viscosities of (n-butylammonium acetate (N4AC) protic ionic liquid + water) and (n-butylammonium nitrate (N4NO 3 ) protic ionic liquid + water) mixtures were measured at T = (293.15, 298.15, 303.15, 308.15, and 313.15) K under atmospheric pressure. Electrical conductivities of the above-mentioned systems were determined at 298.15 K. Excess molar volumes and viscosity deviations were obtained from the experimental results and fitted to the Redlich–Kister equation with satisfactory results. Other volumetric properties, such as apparent molar volumes, partial molar volumes, and excess partial molar volumes were also calculated. The concentration dependence of electrical conductivity was fitted according to the empirical Casteel–Amis equation. Based on the measured and derived properties, the molecular interactions and structural factors in the above-mentioned systems were discussed

Design of instantaneous liquid film thickness measurement system for conductive or non-conductive fluid with high viscosity

Directory of Open Access Journals (Sweden)

Yongxin Yu

2017-06-01

Full Text Available In the paper, a new capacitive sensor with a dielectric film coating was designed to measure the thickness of the liquid film on a flat surface. The measured medium can be conductive or non-conductive fluid with high viscosity such as silicone oil, syrup, CMC solution and melt. With the dielectric film coating, the defects caused by the humidity in a capacitor can be avoided completely. With a excitation frequency 0-20kHz, the static permittivity of capacitive sensor is obtained and stable when small thicknesses are monitored within the frequency of 0-3kHz. Based on the measurement principle, an experimental system was designed and verified including calibration and actual measurement for different liquid film thickness. Experimental results showed that the sensitivity, the resolution, repeatability and linear range of the capacitive sensor are satisfied to the liquid film thickness measurement. Finally, the capacitive measuring system was successfully applied to the water, silicone oil and syrup film thickness measurement.

Extensional viscosity for polymer melts measured in the filament stretching rheometer

DEFF Research Database (Denmark)

Bach, Anders; Rasmussen, Henrik K.; Hassager, Ole

2003-01-01

A new filament stretching rheometer has been constructed to measure the elongational viscosity of polymer melts at high temperatures. Two polymer melts, a LDPE and a LLDPE, were investigated with this rheometer. A constant elongational rate has been obtained by an iterative application of the Orr...

Cellular Viscosity in Prokaryotes and Thermal Stability of Low Molecular Weight Biomolecules.

Science.gov (United States)

Cuecas, Alba; Cruces, Jorge; Galisteo-López, Juan F; Peng, Xiaojun; Gonzalez, Juan M

2016-08-23

Some low molecular weight biomolecules, i.e., NAD(P)H, are unstable at high temperatures. The use of these biomolecules by thermophilic microorganisms has been scarcely analyzed. Herein, NADH stability has been studied at different temperatures and viscosities. NADH decay increased at increasing temperatures. At increasing viscosities, NADH decay rates decreased. Thus, maintaining relatively high cellular viscosity in cells could result in increased stability of low molecular weight biomolecules (i.e., NADH) at high temperatures, unlike what was previously deduced from studies in diluted water solutions. Cellular viscosity was determined using a fluorescent molecular rotor in various prokaryotes covering the range from 10 to 100°C. Some mesophiles showed the capability of changing cellular viscosity depending on growth temperature. Thermophiles and extreme thermophiles presented a relatively high cellular viscosity, suggesting this strategy as a reasonable mechanism to thrive under these high temperatures. Results substantiate the capability of thermophiles and extreme thermophiles (growth range 50-80°C) to stabilize and use generally considered unstable, universal low molecular weight biomolecules. In addition, this study represents a first report, to our knowledge, on cellular viscosity measurements in prokaryotes and it shows the dependency of prokaryotic cellular viscosity on species and growth temperature. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Measuring viscosity with a levitating magnet: application to complex fluids

International Nuclear Information System (INIS)

Even, C; Bouquet, F; Deloche, B; Remond, J

2009-01-01

As an experimental project proposed to students in fourth year of university, a viscometer was developed, consisting of a small magnet levitating in a viscous fluid. The viscous force acting on the magnet is directly measured: viscosities in the range 10-10 6 mPa s are obtained. This experiment is used as an introduction to complex fluids and soft matter physics

Viscosity Measurements and Correlations for 1,1,1,2-tetrafluoroethane (HFC-134a) up to 140 MPa

DEFF Research Database (Denmark)

Comuñas, M.J.P.; Baylaucq, A.; Cisneros, Sergio

2003-01-01

In spite of being one of the most studied refrigerants, large discrepancies in the experimental determination of the dynamic viscosity of 1, 1, 1,2-tetrafluoroethane (HFC-134a) prevail. Additionally, there is a need for supplementary high-pressure measurements that can help to derive sound general...... correlations for the viscosity of this compound. Hence, in this work new dynamic viscosity measurements for HFC-134a using a falling-body viscometer in the temperature range of 293.15-373.15 K and pressures up to 140 MPa are presented. This work high-pressure data in combination with already published data...

A model for the viscosity of dilute smectite gels

International Nuclear Information System (INIS)

Liu, L.

2011-01-01

A simple yet accurate model describing the viscosity of dilute suspensions of sodium montmorillonite in dilute homo-ionic solutions is presented. Taking the clay particle and the surrounding clouds of ions as a whole as an uncharged but soft, coin-like particle, the Huggins' equation for a suspension of uncharged particles is extended in the model to account for not only the primary and the secondary electro-viscous effects, but also the multi-particle interaction. The agreements between the predicted and measured results are excellent. The Huggins' coefficient obtained compares favorably with available data, while the intrinsic viscosity reduces to the Simha's equation in the large limit of ionic strength, suggesting that the model is robust. (authors)

Density and Viscosity Measurement of Diesel Fuels at Combined High Pressure and Elevated Temperature

Directory of Open Access Journals (Sweden)

Carl Schaschke

2013-07-01

Full Text Available We report the measurement of the viscosity and density of various diesel fuels, obtained from British refineries, at elevated pressures up to 500 MPa and temperatures in the range 298 K to 373 K. The measurement and prediction procedures of fluid properties under high pressure conditions is of increasing interest in many processes and systems including enhanced oil recovery, automotive engine fuel injection, braking, and hydraulic systems. Accurate data and understanding of the fluid characteristic in terms of pressure, volume and temperature is required particularly where the fluid is composed of a complex mixture or blend of aliphatic or aromatic hydrocarbons. In this study, high pressure viscosity data was obtained using a thermostatically-controlled falling sinker-type high pressure viscometer to provide reproducible and reliable viscosity data based on terminal velocity sinker fall times. This was supported with density measurements using a micro-pVT device. Both high-pressure devices were additionally capable of illustrating the freezing points of the hydrocarbon mixtures. This work has, thus, provided data that can extend the application of mixtures of commercially available fuels and to test the validity of available predictive density and viscosity models. This included a Tait-style equation for fluid compressibility prediction. For complex diesel fuel compositions, which have many unidentified components, the approach illustrates the need to apply appropriate correlations, which require accurate knowledge or prediction of thermodynamic properties.

Intrinsic viscosity of a suspension of cubes

KAUST Repository

Mallavajula, Rajesh K.

2013-11-06

We report on the viscosity of a dilute suspension of cube-shaped particles. Irrespective of the particle size, size distribution, and surface chemistry, we find empirically that cubes manifest an intrinsic viscosity [η]=3.1±0.2, which is substantially higher than the well-known value for spheres, [η]=2.5. The orientation-dependent intrinsic viscosity of cubic particles is determined theoretically using a finite-element solution of the Stokes equations. For isotropically oriented cubes, these calculations show [η]=3.1, in excellent agreement with our experimental observations. © 2013 American Physical Society.

Chebyshev super spectral viscosity method for a fluidized bed model

International Nuclear Information System (INIS)

Sarra, Scott A.

2003-01-01

A Chebyshev super spectral viscosity method and operator splitting are used to solve a hyperbolic system of conservation laws with a source term modeling a fluidized bed. The fluidized bed displays a slugging behavior which corresponds to shocks in the solution. A modified Gegenbauer postprocessing procedure is used to obtain a solution which is free of oscillations caused by the Gibbs-Wilbraham phenomenon in the spectral viscosity solution. Conservation is maintained by working with unphysical negative particle concentrations

Measurements of the viscosity of carbon dioxide at temperatures from (253.15 to 473.15) K with pressures up to 1.2 MPa

International Nuclear Information System (INIS)

Schäfer, Michael; Richter, Markus; Span, Roland

2015-01-01

Highlights: • A new rotating-body viscometer for the low-pressure region was presented. • A viscosity dependent offset was compensated by calibrating the viscometer. • The viscosity of carbon dioxide was measured at low pressures. • Measurements were carried out from T = (253.15 to 473.15) K with p ≤ 1.2 MPa. • The relative expanded combined uncertainty (k = 2) was U r,c (η) = (0.20 to 0.41)%. - Abstract: The viscosity of carbon dioxide was measured over the temperature range T = (253.15 to 473.15) K with pressures up to 1.2 MPa utilizing a new rotating-body viscometer. The relative expanded combined uncertainty (k = 2) in viscosity (including uncertainties of temperature and pressure) was (0.20 to 0.41)%. The instrument was specifically designed for measurements at low gas densities and enables measurements of the dynamic viscosity at temperatures between T = 253.15 K and T = 473.15 K with pressures up to 2 MPa. For carbon dioxide, the fluid specific measuring range with regard to pressure was limited to 1.2 MPa due to the formation of disturbing vortices inside the measuring cell at higher pressures. The model function for the viscosity measurement was extended in such a way that the dynamic viscosity was measured relative to helium. Therefore, the influence of the geometry of the concentric cylindrical system inside the measuring cell became almost negligible. Moreover, a systematic offset resulting from a small but inevitable eccentricity of the cylindrical system was compensated for. The residual damping, usually measured in vacuum, was calibrated in the entire temperature range using viscosity values of helium, neon and argon calculated ab initio; at T = 298.15 K recommended reference values were used. A viscosity dependent offset of the measured viscosities, which was observed in previously published data, did not occur when using the calibrated residual damping. The new carbon dioxide results were compared to other experimental literature data

Influence Of Specific Mechanical Energy On Cornmeal Viscosity Measured By An On-line System During Twin-screw Extrusion

OpenAIRE

Chang Y.K.; Martinez-Bustos F.; Park T.S.; Kokini J.L.

1999-01-01

The influence of specific mechanical energy (SME) on cornmeal viscosity during the twin-screw extrusion at feed moisture contents of 25 and 30% and screw speeds in the range from 100 to 500 rpm was measured. Cornmeal was extruded in a co-rotating, intermeshing twin-screw coupled to a slit die rheometer. One approach to the on-line rheological measurement is to use a slit die with the extruder. In the present work it was show that shear viscosity decreased as a function of SME. The viscosity o...

Nano-viscosity of supercooled liquid measured by fluorescence correlation spectroscopy: Pressure and temperature dependence and the density scaling

Science.gov (United States)

Meier, G.; Gapinski, J.; Ratajczyk, M.; Lettinga, M. P.; Hirtz, K.; Banachowicz, E.; Patkowski, A.

2018-03-01

The Stokes-Einstein relation allows us to calculate apparent viscosity experienced by tracers in complex media on the basis of measured self-diffusion coefficients. Such defined nano-viscosity values can be obtained through single particle techniques, like fluorescence correlation spectroscopy (FCS) and particle tracking (PT). In order to perform such measurements, as functions of pressure and temperature, a new sample cell was designed and is described in this work. We show that this cell in combination with a long working distance objective of the confocal microscope can be used for successful FCS, PT, and confocal imaging experiments in broad pressure (0.1-100 MPa) and temperature ranges. The temperature and pressure dependent nano-viscosity of a van der Waals liquid obtained from the translational diffusion coefficient measured in this cell by means of FCS obeys the same scaling as the rotational relaxation and macro-viscosity of the system.

Chebyshev super spectral viscosity method for water hammer analysis

Directory of Open Access Journals (Sweden)

Hongyu Chen

2013-09-01

Full Text Available In this paper, a new fast and efficient algorithm, Chebyshev super spectral viscosity (SSV method, is introduced to solve the water hammer equations. Compared with standard spectral method, the method's advantage essentially consists in adding a super spectral viscosity to the equations for the high wave numbers of the numerical solution. It can stabilize the numerical oscillation (Gibbs phenomenon and improve the computational efficiency while discontinuities appear in the solution. Results obtained from the Chebyshev super spectral viscosity method exhibit greater consistency with conventional water hammer calculations. It shows that this new numerical method offers an alternative way to investigate the behavior of the water hammer in propellant pipelines.

Effectiveness of the squeezing out and final squeezing out of petroleum of an increased viscosity by alkaline solutions

Energy Technology Data Exchange (ETDEWEB)

Begnazarov, T.

1979-01-01

The remaining petroleum in the flooded zone is determined by the ratio of viscosity forces to the forces of the surface tension, which are expressed by the coefficient Ka. With this, for each kind of porous medium, there exists a natural cricial value Ka. For the purpose of studying the effect of the given parameters on the value of the remaining petroleum, experiments were carried out on artificial specimens. In the tests, using petroleum of the Mishkin deposit, the surface tension on the boundary of the petroleum with the distilled water and alkaline solutions were respectively equal to 37.1 and 1.33 dynes per centimeter. The experiments showed, that the squeezing out of the petroleum with water or alkaline solutions leads to similar results. This means, that the composite parameter Ka does not affect the value of the remaining petroleum saturation. The effectiveness of the final squeezing out of the petroleum of increased viscosity was also studied. These experiments were carried out in two variations of the injection of the squeezed out agent: in the first variation, the petroleum was squeezed out with water in the first stage, and in the second stage it was squeezed out by an alkaline solution, and in the subsequent stages, a change in the squeezing out agent took place. By finishing the first stage, the attained values of the coefficients of the squeezing out were practically similar (0.72). In the second stage, the final squeezing out of the petroleum with a solution of alkaline, provided a major effect.

THE LIME PURIFICATION OF SUGAR –CONTAINING SOLUTION USING HIGH VISCOSITY COLLOIDAL SOLUTIONS

Directory of Open Access Journals (Sweden)

K. V.

2015-12-01

Full Text Available Aim of the work was to determine the efficiency of combined application of lime and high-viscous suspensions, containing the aluminium nanoparticles as a precursor in treatment of sugar-containing solutions. At the first stage the aluminium nanopowder, encapsulated into a salt matrix, was produced by the combined precipitation from a gas phase of metal and halogenide of alkali metal (NaCl. For the long-term stabilization of aluminum nanoparticles the method, developed by the authors, for dispersing these powders in the composition of polyethylene glycols was used, providing the colloidal solution of high viscosity (gel. At the second stage, as an object of investigation a juice of sugar beet, produced in the laboratory conditions by water extracting from the beet chips, was applied. In the produced juice the main characteristics of its quality were determined: the content of solids, sucrose, its purity was calculated (ratio of sucrose to solids content, in%. The content of protein and pectin components was also determined (as the main components of the colloidal fraction of the diffusion juice. Conventionally, as a basic reagent for the process of a lime pretreatment a lime milk of 1.18 g/cm3 density, prepared by liming the burned lime using hot water, was used. During the experiments the effectiveness of reagents, containing aluminum in nanoform, on the degree of removal of the colloidal dispersion substances in the process of juice purification in sugar beet production and improvement of its quality, is shown. However, the obtained results show that, depending on the method of producing, the additional reagents with aluminium nanoparticles have different effect on change of diffusion juice purity in the process of its treatment by the lime milk.

Effect of gamma irradiation in the viscosity of gelatin and pectin solutions used in food industry; Efeito da radiacao gama sobre a viscosidade de solucoes de gelatina e pectina utilizadas na industria de alimentos

Energy Technology Data Exchange (ETDEWEB)

Inamura, Patricia Yoko

2008-07-01

Pectin is a polysaccharide substance of plant origin that may be used as gelling agent, stabilizer in jams, in yogurt drinks and lactic acid beverages. Gelatin, a protein from bovine origin, in this case, is mainly used as gelling agent due to hydrogel formation during cooling. The {sup 60} Co-irradiation process may cause various modifications in macromolecules, some with industrial application, as reticulation. The dynamic response of viscoelastic materials can be used in order to give information about the structural aspect of a system at molecular level. In the present work samples of pectin with different degree of methoxylation, gelatin and the mixture of both were employed to study the radiation sensitivity by means of viscosity measurements. Solutions prepared with citric pectin with high methoxylation content (ATM) 1 por cent, pectin with low content (BTM) 1 por cent, gelatin 0.5 por cent, 1 por cent and 2 por cent, and the mixture 1 por cent and 2 por cent were irradiated with gamma rays at different doses, up to 15 kGy with dose rate about 2 kGy/h. After irradiation the viscosity was measured within a period of 48 h. The viscosity of ATM and BTM pectin solutions decreased sharply with the radiation dose. However, the gelatin sample presented a great radiation resistance. When pectin and gelatin solutions were mixed a predominance of pectin behavior was found. (author)

Using Micromechanical Resonators to Measure Rheological Properties and Alcohol Content of Model Solutions and Commercial Beverages

Directory of Open Access Journals (Sweden)

Bart W. Hoogenboom

2012-05-01

Full Text Available Micromechanic resonators provide a small-volume and potentially high-throughput method to determine rheological properties of fluids. Here we explore the accuracy in measuring mass density and viscosity of ethanol-water and glycerol-water model solutions, using a simple and easily implemented model to deduce the hydrodynamic effects on resonating cantilevers of various length-to-width aspect ratios. We next show that these measurements can be extended to determine the alcohol percentage of both model solutions and commercial beverages such as beer, wine and liquor. This demonstrates how micromechanical resonators can be used for quality control of every-day drinks.

Volumetric and viscometric studies of glucose in binary aqueous solutions of urea at different temperatures

International Nuclear Information System (INIS)

Samanta, T.; Saharay, S.K.

2010-01-01

Densities and viscosities of glucose in (1.0, 2.5, and 5.0) mass% aqueous urea solutions have been measured at T = (298.15, 303.15, 308.15, and 313.15) K, respectively. Apparent molar volumes, limiting partial molar volume, and relative viscosity have been obtained from the density and viscosity results. Limiting partial molar expansibilities have also been calculated from the temperature dependence of limiting partial molar volumes. The viscosity data have been analyzed by using the modified Jones-Dole equation. The results are used to establish the nature of solute-solute and solute-solvent interactions. Transition state treatment of the relative viscosity was also used for the calculation of activation parameters of viscous flow. Pour findings show that the solute acts as a water structure former and provides strong solute-solvent interaction.

Volumetric and viscometric studies of urea in binary aqueous solutions of glucose at different temperatures

International Nuclear Information System (INIS)

Samanta, T.; Ray, A.

2010-01-01

Densities and viscosities of urea in (1.0, 2.5, and 5.0) mass% of aqueous glucose solutions have been measured at T = (298.15, 303.15, 308.15, and 313.15) K, respectively. Apparent molar volumes, limiting partial molar volume, and relative viscosity have been obtained from the density and viscosity data. Limiting partial molar expansibilities have also been calculated from the temperature dependence of limiting partial molar volumes. The viscosity data has been analyzed using the Jones-Dole equation. The results are used to establish the nature of solute-solute and solute-solvent interactions. The activation parameters of viscous flow have also been calculated on the basis of transition state treatment of the relative viscosity. Result shows that the solute acts as water structure breaker and posses' weak solute-solvent interaction.

New instrument for on-line viscosity measurement of fermentation media.

Science.gov (United States)

Picque, D; Corrieu, G

1988-01-01

In an attempt to resolve the difficult problem of on-line determination of the viscosity of non-Newtonian fermentation media, the authors have used a vibrating rod sensor mounted on a bioreactor. The sensor signal decreases nonlinearly with increased apparent viscosity. Electronic filtering of the signal damps the interfering effect of aeration and mechanical agitation. Sensor drift is very low (0.03% of measured value per hour). On the rheological level the sensor is primarily an empirical tool that must be specifically calibrated for each fermentation process. Once this is accomplished, it becomes possible to establish linear or second-degree correlations between the electrical signal from the sensor and the essential parameters of the fermentation process in question (pH of a fermented milk during acidification, concentration of extra cellular polysaccharide). In addition, by applying the power law to describe the rheological behavior of fermentation media, we observe a second-order polynomial correlation between the sensor signal and the behavior index (n).

Investigations on the detection of irradiated food by measuring the viscosity of suspended spices and dried vegetables

Science.gov (United States)

Heide, L.; Nürnberger, E.; Bögl, K. W.

Studies on the viscosity behavior were performed with 20 different spices or dried vegetables. In nine spices (cinnamon, ginger, mustard seed, celery, onions, shallots, lemon peel, black and white pepper) differences between unirradiated and irradiated samples were observed. Further lots were investigated to estimate the variations of viscosity depending on the origin of the samples. Additional storage experiments showed that measuring the viscosity may be a simple method to identify some radiation treated spices even after years.

A microfluidic device for simultaneous measurement of viscosity and flow rate of blood in a complex fluidic network

OpenAIRE

Jun Kang, Yang; Yeom, Eunseop; Lee, Sang-Joon

2013-01-01

Blood viscosity has been considered as one of important biophysical parameters for effectively monitoring variations in physiological and pathological conditions of circulatory disorders. Standard previous methods make it difficult to evaluate variations of blood viscosity under cardiopulmonary bypass procedures or hemodialysis. In this study, we proposed a unique microfluidic device for simultaneously measuring viscosity and flow rate of whole blood circulating in a complex fluidic network i...

Preparation of encapsulated proteins dissolved in low viscosity fluids

International Nuclear Information System (INIS)

Ehrhardt, Mark R.; Flynn, Peter F.; Wand, A. Joshua

1999-01-01

The majority of proteins are too large to be comprehensively examined by solution NMR methods, primarily because they tumble too slowly in solution. One potential approach to making the NMR relaxation properties of large proteins amenable to modern solution NMR techniques is to encapsulate them in a reverse micelle which is dissolved in a low viscosity fluid. Unfortunately, promising low viscosity fluids such as the short chain alkanes, supercritical carbon dioxide, and various halocarbon refrigerants all require the application of significant pressure to be kept liquefied at room temperature. Here we describe the design and use of a simple cost effective NMR tube suitable for the preparation of solutions of proteins encapsulated in reverse micelles dissolved in such fluids

A microfluidic device for simultaneous measurement of viscosity and flow rate of blood in a complex fluidic network.

Science.gov (United States)

Jun Kang, Yang; Yeom, Eunseop; Lee, Sang-Joon

2013-01-01

Blood viscosity has been considered as one of important biophysical parameters for effectively monitoring variations in physiological and pathological conditions of circulatory disorders. Standard previous methods make it difficult to evaluate variations of blood viscosity under cardiopulmonary bypass procedures or hemodialysis. In this study, we proposed a unique microfluidic device for simultaneously measuring viscosity and flow rate of whole blood circulating in a complex fluidic network including a rat, a reservoir, a pinch valve, and a peristaltic pump. To demonstrate the proposed method, a twin-shaped microfluidic device, which is composed of two half-circular chambers, two side channels with multiple indicating channels, and one bridge channel, was carefully designed. Based on the microfluidic device, three sequential flow controls were applied to identify viscosity and flow rate of blood, with label-free and sensorless detection. The half-circular chamber was employed to achieve mechanical membrane compliance for flow stabilization in the microfluidic device. To quantify the effect of flow stabilization on flow fluctuations, a formula of pulsation index (PI) was analytically derived using a discrete fluidic circuit model. Using the PI formula, the time constant contributed by the half-circular chamber is estimated to be 8 s. Furthermore, flow fluctuations resulting from the peristaltic pumps are completely removed, especially under periodic flow conditions within short periods (T viscosity with respect to varying flow rate conditions [(a) known blood flow rate via a syringe pump, (b) unknown blood flow rate via a peristaltic pump]. As a result, the flow rate and viscosity of blood can be simultaneously measured with satisfactory accuracy. In addition, the proposed method was successfully applied to identify the viscosity of rat blood, which circulates in a complex fluidic network. These observations confirm that the proposed method can be used for

Possible ambiguities when testing viscosity in compendial monographs - characterisation of grades of cellulose ethers.

Science.gov (United States)

Doelker, E

2010-10-01

The European Pharmacopoeia (Ph. Eur.) monographs for the water-soluble cellulose ethers require viscosity determination, either in the "Tests" section or in the non-mandatory "Functionality-related characteristics" section. Although the derivatives are chemically closely related and used for similar applications, the viscosity tests strongly differ. Some monographs generically speak of the rotating viscometer method (2.2.10) and a fixed shear rate (e.g. 10 s-1), which would necessitate an absolute measuring system, while others recommend the capillary viscometer method for product grades of less than 600 mPa∙s and the rotating viscometer method and given operating conditions for grades of higher nominal viscosity. Viscometer methods also differ between the United States Pharmacopeia/National Formulary (USP/NF) and the Japanese Pharmacopoeia (JP) monographs. In addition, for some cellulose ethers the tests sometimes diverge from one pharmacopoeia to the other, although the three compendiums are in a harmonisation process. But the main issue is that the viscometer methods originally employed by the product manufacturers are often not those described in the corresponding monographs and generally vary from one manufacturer to the other. The aim of this study was therefore to investigate whether such a situation could invalidate the present pharmacopoeial requirements. 2 per cent solutions of several viscosity grades of hydroxyethylcellulose, hypromellose and methylcellulose were prepared and their (apparent) viscosity determined using both relative and absolute viscometer methods. The viscometer method used not only affects the measured viscosity but experimental values generally do not correspond to the product nominal viscosities. It emerges that, in contrast to Newtonian solutions (i.e. those of grades of up to ca. 50 mPa∙s nominal viscosity), some of the viscometer methods currently specified in the monographs are not able unambiguously to characterise the

Comparison of parallel viscosity with neoclassical theory

International Nuclear Information System (INIS)

Ida, K.; Nakajima, N.

1996-04-01

Toroidal rotation profiles are measured with charge exchange spectroscopy for the plasma heated with tangential NBI in CHS heliotron/torsatron device to estimate parallel viscosity. The parallel viscosity derived from the toroidal rotation velocity shows good agreement with the neoclassical parallel viscosity plus the perpendicular viscosity. (μ perpendicular = 2 m 2 /s). (author)

Effect of increased groundwater viscosity on the remedial performance of surfactant-enhanced air sparging

Science.gov (United States)

Choi, Jae-Kyeong; Kim, Heonki; Kwon, Hobin; Annable, Michael D.

2018-03-01

The effect of groundwater viscosity control on the performance of surfactant-enhanced air sparging (SEAS) was investigated using 1- and 2-dimensional (1-D and 2-D) bench-scale physical models. The viscosity of groundwater was controlled by a thickener, sodium carboxymethylcellulose (SCMC), while an anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), was used to control the surface tension of groundwater. When resident DI water was displaced with a SCMC solution (500 mg/L), a SDBS solution (200 mg/L), and a solution with both SCMC (500 mg/L) and SDBS (200 mg/L), the air saturation for sand-packed columns achieved by air sparging increased by 9.5%, 128%, and 154%, respectively, (compared to that of the DI water-saturated column). When the resident water contained SCMC, the minimum air pressure necessary for air sparging processes increased, which is considered to be responsible for the increased air saturation. The extent of the sparging influence zone achieved during the air sparging process using the 2-D model was also affected by viscosity control. Larger sparging influence zones (de-saturated zone due to air injection) were observed for the air sparging processes using the 2-D model initially saturated with high-viscosity solutions, than those without a thickener in the aqueous solution. The enhanced air saturations using SCMC for the 1-D air sparging experiment improved the degradative performance of gaseous oxidation agent (ozone) during air sparging, as measured by the disappearance of fluorescence (fluorescein sodium salt). Based on the experimental evidence generated in this study, the addition of a thickener in the aqueous solution prior to air sparging increased the degree of air saturation and the sparging influence zone, and enhanced the remedial potential of SEAS for contaminated aquifers.

Methods of viscosity measurements in sealed ampoules

Science.gov (United States)

Mazuruk, Konstantin

1999-07-01

Viscosity of semiconductors and metallic melts is usually measured by oscillating cup method. This method utilizes the melts contained in vacuum sealed silica ampoules, thus the problems related to volatility, contamination, and high temperature and pressure can be alleviate. In a typical design, the time required for a single measurement is of the order of one hour. In order to reduce this time to a minute range, a high resolution angular detection system is implemented in our design of the viscometer. Furthermore, an electromagnet generating a rotational magnetic field (RMF) is incorporated into the apparatus. This magnetic field can be used to remotely and nonintrusively measure the electrical conductivity of the melt. It can also be used to induce a well controlled rotational flow in the system. The transient behavior of this flow can potentially yield of the fluid. Based on RMF implementation, two novel viscometry methods are proposed in this work: a) the transient torque method, b) the resonance method. A unified theoretical approach to the three methods is presented along with the initial test result of the constructed apparatus. Advantages of each of the method are discussed.

Viscosity measurement - probably a means for detecting radiation treatment of spices. Viskositaetsmessung - ein Verfahren zur Identifizierung strahlenbehandelter Gewuerze

Energy Technology Data Exchange (ETDEWEB)

Heide, L; Albrich, S; Boegl, K W; Mohr, E; Wichmann, G

1987-12-01

The viscosity of 13 different spices and dried vegetables in total was measured. Optimal conditions were first determined for each product, i.e. concentration, pH-value, temperature, particle size and soaking time. For method evaluation, examinations were primarily performed to study the effect of storage, the reproducibility and the influence of the different varieties of the same spice. In supplement, for pepper, the viscosity was measured as a function of radiation dose. In summation, significant changes in the gel forming capability after irradiation could be observed after preliminary experiments in 8 dried spices (ginger, carrots, leek, cloves, pepper, celery, cinnamon and onions). With 3 spices (ginger, pepper and cinnamon) could the results from examining all different varieties of the same spice be substantiated. An additional influence of storage time on viscosity could not be proved during the investigative period of 8 months. Generally seen, there is no possibility of being able to identify an irradiated spice on the basis of viscosity measurements alone, since the difference between the varieties of one and the same spice is considerably great. However, radiation treatment can be reliably excluded with ginger, pepper and cinnamon, if the viscosities are high (10-20 Pa x s).

The influence of specific mechanical energy on cornmeal viscosity measured by an on-line system during twin-screw extrusion

OpenAIRE

CHANG, Y. K.; MARTINEZ-BUSTOS, F.; PARK, T. S.; KOKINI, J .L.

1999-01-01

The influence of specific mechanical energy (SME) on cornmeal viscosity during the twin-screw extrusion at feed moisture contents of 25 and 30% and screw speeds in the range from 100 to 500 rpm was measured. Cornmeal was extruded in a co-rotating, intermeshing twin-screw coupled to a slit die rheometer. One approach to the on-line rheological measurement is to use a slit die with the extruder. In the present work it was show that shear viscosity decreased as a function of SME. The viscosity o...

Solution for laminar natural convection flows in a square cavity with temperature dependent viscosity

Energy Technology Data Exchange (ETDEWEB)

Sanchez, J.G. [Parsons Brinckerhoff, New York, NY (United States)

1995-12-31

This paper presents an examination of numerical results for the buoyancy-driven convection heat transfer problem, in a two-dimensional enclosure under steady-state, laminar, incompressible, and temperature dependent viscosity fluid flow conditions. The vertical walls are exposed to different temperatures and the top and bottom are insulated. Rayleigh numbers of 10{sup 4}, 10{sup 5}, and 10{sup 6} are considered. Specific heat, thermal conductivity, and the thermal expansion coefficient are assumed constant. Density variation is included using the Oberbeck-Boussinesq approximation. The results are obtained using the SIMPLEC solution technique based on a power-law, finite-volume discretization scheme. The hydrodynamic and thermal fields are presented at various locations in the enclosures.

The influence of specific mechanical energy on cornmeal viscosity measured by an on-line system during twin-screw extrusion

Directory of Open Access Journals (Sweden)

Y. K. CHANG

1999-09-01

Full Text Available The influence of specific mechanical energy (SME on cornmeal viscosity during the twin-screw extrusion at feed moisture contents of 25 and 30% and screw speeds in the range from 100 to 500 rpm was measured. Cornmeal was extruded in a co-rotating, intermeshing twin-screw coupled to a slit die rheometer. One approach to the on-line rheological measurement is to use a slit die with the extruder. In the present work it was show that shear viscosity decreased as a function of SME. The viscosity of cornmeal at the exit die was influenced by screw speed, rate of total mass flow, mass temperature inside the extruder and SME. An increase in screw speed resulted in an increase in SME and a decrease in viscosity. A reduction in slit die height and an increase in screw speed and mass temperature led to a remarkable macromolecular degradation of the starch, as evidenced by the decrease in viscosity.

Effective viscosity of dispersions approached by a statistical continuum method

NARCIS (Netherlands)

Mellema, J.; Willemse, M.W.M.

1983-01-01

The problem of the determination of the effective viscosity of disperse systems (emulsions, suspensions) is considered. On the basis of the formal solution of the equations governing creeping flow in a statistically homogeneous dispersion, the effective viscosity is expressed in a series expansion

Density, speed of sound, viscosity and refractive index properties of aqueous solutions of vitamins B1.HCl and B6.HCl at temperatures (278.15, 288.15, and 298.15) K

International Nuclear Information System (INIS)

Dhondge, Sudhakar S.; Deshmukh, Dinesh W.; Paliwal, Lalitmohan J.

2013-01-01

Highlights: ► Study of aqueous solutions of vitamins B 1 .HCl and B 6 .HCl at different temperatures has been presented. ► These are important vitamins. ► Different interactions among solute and solvents have been investigated. ► The results are interpreted in terms of water structure making and breaking effects due to cations. -- Abstract: The experimental values of density (ρ), speed of sound (u), absolute viscosity (η) and refractive index (n D ) properties are reported for aqueous solutions of thiamine hydrochloride (vitamin B 1 .HCl) and pyridoxine hydrochloride (vitamin B 6 .HCl) within the concentration range (0.01 to 0.55) mol ⋅ kg −1 at three different temperatures, viz. T/K = 278.15, 288.15, and 298.15. Using experimental data, different derived parameters such as the apparent molar volume of solute (ϕ V ), isentropic compressibility of solution (β S ), apparent molar isentropic compressibility of solute (ϕ KS ) and relative viscosity of solution (η r ) have been computed. The limiting values of apparent molar volume (ϕ V 0 ) and apparent molar isentropic compressibility (ϕ KS 0 ) have been obtained. The limiting apparent molar expansivity (ϕ E 0 ) of solute, coefficient of thermal expansion (α ∗ ) and hydration numbers (n h ) of above vitamins in the aqueous medium have also been estimated. The experimental values of relative viscosity are used to calculate the Jones–Dole equation viscosity A and B coefficients for the hydrochlorides. The temperature coefficients of B i.e. (dB/dT) for these solutes have been used to study water structure making and breaking effects due to cations. Further, a discussion is made on the basis of solute–solute and solute–solvent interactions

Drop Spreading with Random Viscosity

Science.gov (United States)

Xu, Feng; Jensen, Oliver

2016-11-01

Airway mucus acts as a barrier to protect the lung. However as a biological material, its physical properties are known imperfectly and can be spatially heterogeneous. In this study we assess the impact of these uncertainties on the rate of spreading of a drop (representing an inhaled aerosol) over a mucus film. We model the film as Newtonian, having a viscosity that depends linearly on the concentration of a passive solute (a crude proxy for mucin proteins). Given an initial random solute (and hence viscosity) distribution, described as a Gaussian random field with a given correlation structure, we seek to quantify the uncertainties in outcomes as the drop spreads. Using lubrication theory, we describe the spreading of the drop in terms of a system of coupled nonlinear PDEs governing the evolution of film height and the vertically-averaged solute concentration. We perform Monte Carlo simulations to predict the variability in the drop centre location and width (1D) or area (2D). We show how simulation results are well described (at much lower computational cost) by a low-order model using a weak disorder expansion. Our results show for example how variability in the drop location is a non-monotonic function of the solute correlation length increases. Engineering and Physical Sciences Research Council.

Viscosity Meaurement Technique for Metal Fuels

Energy Technology Data Exchange (ETDEWEB)

Ban, Heng [Utah State Univ., Logan, UT (United States). Mechanical and Aerospace Engineering; Kennedy, Rory [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-02-09

Metallic fuels have exceptional transient behavior, excellent thermal conductivity, and a more straightforward reprocessing path, which does not separate out pure plutonium from the process stream. Fabrication of fuel containing minor actinides and rare earth (RE) elements for irradiation tests, for instance, U-20Pu-3Am-2Np-1.0RE-15Zr samples at the Idaho National Laboratory, is generally done by melt casting in an inert atmosphere. For the design of a casting system and further scale up development, computational modeling of the casting process is needed to provide information on melt flow and solidification for process optimization. Therefore, there is a need for melt viscosity data, the most important melt property that controls the melt flow. The goal of the project was to develop a measurement technique that uses fully sealed melt sample with no Americium vapor loss to determine the viscosity of metallic melts and at temperatures relevant to the casting process. The specific objectives of the project were to: develop mathematical models to establish the principle of the measurement method, design and build a viscosity measurement prototype system based on the established principle, and calibrate the system and quantify the uncertainty range. The result of the project indicates that the oscillation cup technique is applicable for melt viscosity measurement. Detailed mathematical models of innovative sample ampoule designs were developed to not only determine melt viscosity, but also melt density under certain designs. Measurement uncertainties were analyzed and quantified. The result of this project can be used as the initial step toward the eventual goal of establishing a viscosity measurement system for radioactive melts.

Viscosity Meaurement Technique for Metal Fuels

International Nuclear Information System (INIS)

Ban, Heng

2015-01-01

Metallic fuels have exceptional transient behavior, excellent thermal conductivity, and a more straightforward reprocessing path, which does not separate out pure plutonium from the process stream. Fabrication of fuel containing minor actinides and rare earth (RE) elements for irradiation tests, for instance, U-20Pu-3Am-2Np-1.0RE-15Zr samples at the Idaho National Laboratory, is generally done by melt casting in an inert atmosphere. For the design of a casting system and further scale up development, computational modeling of the casting process is needed to provide information on melt flow and solidification for process optimization. Therefore, there is a need for melt viscosity data, the most important melt property that controls the melt flow. The goal of the project was to develop a measurement technique that uses fully sealed melt sample with no Americium vapor loss to determine the viscosity of metallic melts and at temperatures relevant to the casting process. The specific objectives of the project were to: develop mathematical models to establish the principle of the measurement method, design and build a viscosity measurement prototype system based on the established principle, and calibrate the system and quantify the uncertainty range. The result of the project indicates that the oscillation cup technique is applicable for melt viscosity measurement. Detailed mathematical models of innovative sample ampoule designs were developed to not only determine melt viscosity, but also melt density under certain designs. Measurement uncertainties were analyzed and quantified. The result of this project can be used as the initial step toward the eventual goal of establishing a viscosity measurement system for radioactive melts.

Extensional flow of low-viscosity fluids in capillary bridges formed by pulsed surface acoustic wave jetting

International Nuclear Information System (INIS)

Bhattacharjee, P K; McDonnell, A G; Prabhakar, R; Yeo, L Y; Friend, J

2011-01-01

Forming capillary bridges of low-viscosity (∼<10 mPa s) fluids is difficult, making the study of their capillary-thinning behavior and the measurement of the fluid's extensional viscosity difficult as well. Current techniques require some time to form a liquid bridge from the stretching of a droplet. Rapidly stretching a liquid bridge using these methods can cause its breakup if the viscosity is too low. Stretching more slowly allows the bridge to thin and break up before a suitable bridge geometry can be established to provide reliable and accurate rheological data. Using a pulsed surface acoustic wave to eject a jet from a sessile droplet, a capillary bridge may be formed in about 7.5 ms, about seven times quicker than current methods. With this approach, capillary bridges may be formed from Newtonian and non-Newtonian fluids having much lower viscosities-water, 0.04% by weight solution of high-molecular-weight (7 MDa) polystyrene in dioctyl phthalate and 0.25% fibrinogen solution in demineralized water, for example. Details of the relatively simple system used to achieve these results are provided, as are experimental results indicating deviations from a Newtonian response by the low-viscosity non-Newtonian fluids used in our study.

Extensional flow of low-viscosity fluids in capillary bridges formed by pulsed surface acoustic wave jetting

Energy Technology Data Exchange (ETDEWEB)

Bhattacharjee, P K; McDonnell, A G; Prabhakar, R; Yeo, L Y; Friend, J, E-mail: james.friend@monash.edu.au [MicroNanophysics Research Laboratory, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC 3800 (Australia); Melbourne Centre for Nanofabrication, Melbourne, VIC 3800 (Australia)

2011-02-15

Forming capillary bridges of low-viscosity ({approx}<10 mPa s) fluids is difficult, making the study of their capillary-thinning behavior and the measurement of the fluid's extensional viscosity difficult as well. Current techniques require some time to form a liquid bridge from the stretching of a droplet. Rapidly stretching a liquid bridge using these methods can cause its breakup if the viscosity is too low. Stretching more slowly allows the bridge to thin and break up before a suitable bridge geometry can be established to provide reliable and accurate rheological data. Using a pulsed surface acoustic wave to eject a jet from a sessile droplet, a capillary bridge may be formed in about 7.5 ms, about seven times quicker than current methods. With this approach, capillary bridges may be formed from Newtonian and non-Newtonian fluids having much lower viscosities-water, 0.04% by weight solution of high-molecular-weight (7 MDa) polystyrene in dioctyl phthalate and 0.25% fibrinogen solution in demineralized water, for example. Details of the relatively simple system used to achieve these results are provided, as are experimental results indicating deviations from a Newtonian response by the low-viscosity non-Newtonian fluids used in our study.

Capillary waves with surface viscosity

Science.gov (United States)

Shen, Li; Denner, Fabian; Morgan, Neal; van Wachem, Berend; Dini, Daniele

2017-11-01

Experiments over the last 50 years have suggested a correlation between the surface (shear) viscosity and the stability of a foam or emulsion. With recent techniques allowing more accurate measurements of the elusive surface viscosity, we examine this link theoretically using small-amplitude capillary waves in the presence of the Marangoni effect and surface viscosity modelled via the Boussinesq-Scriven model. The surface viscosity effect is found to contribute a damping effect on the amplitude of the capillary wave with subtle differences to the effect of the convective-diffusive Marangoni transport. The general wave dispersion is augmented to take into account the Marangoni and surface viscosity effects, and a first-order correction to the critical damping wavelength is derived. The authors acknowledge the financial support of the Shell University Technology Centre for fuels and lubricants.

Effect of β-cyclodextrin on Rheological Properties of some Viscosity Modifiers.

Science.gov (United States)

Rao, G Chandra Sekhara; Ramadevi, K; Sirisha, K

2014-01-01

Cyclodextrins are a group of novel excipients, extensively used in the present pharmaceutical industry. Sometimes they show significant interactions with other conventional additives used in the formulation of dosage forms. The effect of β-cyclodextrin on the rheological properties of aqueous solutions of some selected viscosity modifiers was studied in the present work. β-cyclodextrin showed two different types of effects on the rheology of the selected polymers. In case of natural polymers like xanthan gum and guar gum, enhanced apparent viscosity was found and in case of semi-synthetic polymers like sodium carboxymethyl cellulose and methyl cellulose, reduction in apparent viscosity was found. β-cyclodextrin was included at 0.5, 1 and 2% w/v concentrations into the polymeric solutions. These findings are useful in the adjustment of concentrations of viscosity modifiers during the formulation of physically stable disperse systems.

The Viscosity of Organic Liquid Mixtures

Science.gov (United States)

Len, C. W.; Trusler, J. P. M.; Vesovic, V.; Wakeham, W. A.

2006-01-01

The paper reports measurements of the viscosity and density of two heavy hydrocarbon mixtures, Dutrex and Arab Light Flashed Distillate (ALFD), and of their mixtures with hydrogen. The measurements have been carried out with a vibrating-wire device over a range of temperatures from 399 to 547 K and at pressures up to 20 MPa. Measurements have also been carried out on systems in which hydrogen at different concentrations has been dissolved in the liquids. The measurements have an estimated uncertainty of ±5% for viscosity and ±2% for density and represent the first results on these prototypical heavy hydrocarbons. The results reveal that the addition of hydrogen reduces both the density and viscosity of the original hydrocarbon mixture at a particular temperature and pressure.

Density and viscosity study of nicotinic acid and nicotinamide in dilute aqueous solutions at and around the temperature of the maximum density of water

International Nuclear Information System (INIS)

Dhondge, Sudhakar S.; Dahasahasra, Prachi N.; Paliwal, Lalitmohan J.; Deshmukh, Dinesh W.

2014-01-01

Highlights: • Volumetric and transport behaviour of aqueous solutions of important vitamins are reported. • Various interactions of nicotinic acid and nicotinamide with water have been reported. • The temperature dependence of interactions between solute and solvent is discussed. • The study indicates that nicotinamide is more hydrated as compared to nicotinic acid. - Abstract: In the present study, we report experimental densities (ρ) and viscosities (η) of aqueous solutions of nicotinic acid and nicotinamide within the concentration range (0 to 0.1) mol · kg −1 at T = (275.15, 277.15 and 279.15) K. These parameters are then used to obtain thermodynamic and transport functions such as apparent molar volume of solute (V ϕ ), limiting apparent molar volume of solute (V ϕ 0 ), limiting apparent molar expansivity of solute (E ϕ 0 ), coefficient of thermal expansion (α ∗ ), Jones–Dole equation viscosity A, B and D coefficients, temperature derivative of B coefficient i.e. (dB/dT) and hydration number (n H ), etc. The activation parameters of viscous flow for the binary mixtures have been determined and discussed in terms of Eyring’s transition state theory. These significant parameters are helpful to study the structure promoting or destroying tendency of solute and various interactions present in (nicotinic acid + water) and (nicotinamide + water) binary mixtures

Whole-blood viscosity and the insulin-resistance syndrome.

Science.gov (United States)

Høieggen, A; Fossum, E; Moan, A; Enger, E; Kjeldsen, S E

1998-02-01

In a previous study we found that elevated blood viscosity was linked to the insulin resistance syndrome, and we proposed that high blood viscosity may increase insulin resistance. That study was based on calculated viscosity. To determine whether directly measured whole-blood viscosity was related to the insulin-resistance syndrome in the same way as calculated viscosity had been found to be. Healthy young men were examined with the hyperinsulinemic isoglycemic glucose clamp technique, and we related insulin sensitivity (glucose disposal rate) to other metabolic parameters and to blood viscosity. We established a technique for direct measurement of whole-blood viscosity. There were statistically significant negative correlations between glucose disposal rate and whole-blood viscosity at low and high shear rates (r = -0.41, P = 0.007 for both, n = 42). Whole-blood viscosity was correlated positively (n = 15) to serum triglyceride (r = 0.54, P = 0.04) and total cholesterol (r = 0.52, P = 0.05), and negatively with high-density lipoprotein cholesterol (r = -0.53, P = 0.04) concentrations. Insulin sensitivity index was correlated positively to high-density lipoprotein cholesterol (r = 0.54, P = 0.04) and negatively to serum triglyceride (r = -0.69, P = 0.005) and to total cholesterol (r = -0.81, P = 0.0003) concentrations. The present results demonstrate for the first time that there is a negative relationship between directly measured whole-blood viscosity and insulin sensitivity as a part of the insulin-resistance syndrome. Whole-blood viscosity contributes to the total peripheral resistance, and these results support the hypothesis that insulin resistance has a hemodynamic basis.

Viscosity of particle laden films

Directory of Open Access Journals (Sweden)

Timounay Yousra

2017-01-01

Full Text Available We perform retraction experiments on soap films where large particles bridge the two interfaces. Local velocities are measured by PIV during the unstationnary regime. The velocity variation in time and space can be described by a continuous fluid model from which effective viscosity (shear and dilatational of particulate films is measured. The 2D effective viscosity of particulate films η2D increases with particle surface fraction ϕ: at low ϕ, it tends to the interfacial dilatational viscosity of the liquid/air interfaces and it diverges at the critical particle surface fraction ϕc ≃ 0.84. Experimental data agree with classical viscosity laws of hard spheres suspensions adapted to the 2D geometry, assuming viscous dissipation resulting from the squeeze of the liquid/air interfaces between the particles. Finally, we show that the observed viscous dissipation in particulate films has to be considered to describe the edge velocity during a retraction experiment at large particle coverage.

Viscosity of particle laden films

Science.gov (United States)

Timounay, Yousra; Rouyer, Florence

2017-06-01

We perform retraction experiments on soap films where large particles bridge the two interfaces. Local velocities are measured by PIV during the unstationnary regime. The velocity variation in time and space can be described by a continuous fluid model from which effective viscosity (shear and dilatational) of particulate films is measured. The 2D effective viscosity of particulate films η2D increases with particle surface fraction ϕ: at low ϕ, it tends to the interfacial dilatational viscosity of the liquid/air interfaces and it diverges at the critical particle surface fraction ϕc ≃ 0.84. Experimental data agree with classical viscosity laws of hard spheres suspensions adapted to the 2D geometry, assuming viscous dissipation resulting from the squeeze of the liquid/air interfaces between the particles. Finally, we show that the observed viscous dissipation in particulate films has to be considered to describe the edge velocity during a retraction experiment at large particle coverage.

Comparative evaluation of aqueous humor viscosity.

Science.gov (United States)

Davis, Kyshia; Carter, Renee; Tully, Thomas; Negulescu, Ioan; Storey, Eric

2015-01-01

To evaluate aqueous humor viscosity in the raptor, dog, cat, and horse, with a primary focus on the barred owl (Strix varia). Twenty-six raptors, ten dogs, three cats, and one horse. Animals were euthanized for reasons unrelated to this study. Immediately, after horizontal and vertical corneal dimensions were measured, and anterior chamber paracentesis was performed to quantify anterior chamber volume and obtain aqueous humor samples for viscosity analysis. Dynamic aqueous humor viscosity was measured using a dynamic shear rheometer (AR 1000 TA Instruments, New Castle, DE, USA) at 20 °C. Statistical analysis included descriptive statistics, unpaired t-tests, and Tukey's test to evaluate the mean ± standard deviation for corneal diameter, anterior chamber volume, and aqueous humor viscosity amongst groups and calculation of Spearman's coefficient for correlation analyses. The mean aqueous humor viscosity in the barred owl was 14.1 centipoise (cP) ± 9, cat 4.4 cP ± 0.2, and dog 2.9 cP ± 1.3. The aqueous humor viscosity for the horse was 1 cP. Of the animals evaluated in this study, the raptor aqueous humor was the most viscous. The aqueous humor of the barred owl is significantly more viscous than the dog (P humor viscosity of the raptor, dog, cat, and horse can be successfully determined using a dynamic shear rheometer. © 2014 American College of Veterinary Ophthalmologists.

Mantle viscosity structure constrained by joint inversions of seismic velocities and density

Science.gov (United States)

Rudolph, M. L.; Moulik, P.; Lekic, V.

2017-12-01

The viscosity structure of Earth's deep mantle affects the thermal evolution of Earth, the ascent of mantle upwellings, sinking of subducted oceanic lithosphere, and the mixing of compositional heterogeneities in the mantle. Modeling the long-wavelength dynamic geoid allows us to constrain the radial viscosity profile of the mantle. Typically, in inversions for the mantle viscosity structure, wavespeed variations are mapped into density variations using a constant- or depth-dependent scaling factor. Here, we use a newly developed joint model of anisotropic Vs, Vp, density and transition zone topographies to generate a suite of solutions for the mantle viscosity structure directly from the seismologically constrained density structure. The density structure used to drive our forward models includes contributions from both thermal and compositional variations, including important contributions from compositionally dense material in the Large Low Velocity Provinces at the base of the mantle. These compositional variations have been neglected in the forward models used in most previous inversions and have the potential to significantly affect large-scale flow and thus the inferred viscosity structure. We use a transdimensional, hierarchical, Bayesian approach to solve the inverse problem, and our solutions for viscosity structure include an increase in viscosity below the base of the transition zone, in the shallow lower mantle. Using geoid dynamic response functions and an analysis of the correlation between the observed geoid and mantle structure, we demonstrate the underlying reason for this inference. Finally, we present a new family of solutions in which the data uncertainty is accounted for using covariance matrices associated with the mantle structure models.

Effect of viscosity on tear drainage and ocular residence time.

Science.gov (United States)

Zhu, Heng; Chauhan, Anuj

2008-08-01

An increase in residence time of dry eye medications including artificial tears will likely enhance therapeutic benefits. The drainage rates and the residence time of eye drops depend on the viscosity of the instilled fluids. However, a quantitative understanding of the dependence of drainage rates and the residence time on viscosity is lacking. The current study aims to develop a mathematical model for the drainage of Newtonian fluids and also for power-law non-Newtonian fluids of different viscosities. This study is an extension of our previous study on the mathematical model of tear drainage. The tear drainage model is modified to describe the drainage of Newtonian fluids with viscosities higher than the tear viscosity and power-law non-Newtonian fluids with rheological parameters obtained from fitting experimental data in literature. The drainage rate through canaliculi was derived from the modified drainage model and was incorporated into a tear mass balance to calculate the transients of total solute quantity in ocular fluids and the bioavailability of instilled drugs. For Newtonian fluids, increasing the viscosity does not affect the drainage rate unless the viscosity exceeds a critical value of about 4.4 cp. The viscosity has a maximum impact on drainage rate around a value of about 100 cp. The trends are similar for shear thinning power law fluids. The transients of total solute quantity, and the residence time agrees at least qualitatively with experimental studies. A mathematical model has been developed for the drainage of Newtonian fluids and power-law fluids through canaliculi. The model can quantitatively explain different experimental observations on the effect of viscosity on the residence of instilled fluids on the ocular surface. The current study is helpful for understanding the mechanism of fluid drainage from the ocular surface and for improving the design of dry eye treatments.

Understanding and modulating opalescence and viscosity in a monoclonal antibody formulation

OpenAIRE

Salinas, Branden A; Sathish, Hasige A; Bishop, Steven M; Harn, Nick; Carpenter, John F; Randolph, Theodore W

2010-01-01

Opalescence and high viscosities can pose challenges for high concentration formulation of antibodies. Both phenomena result from protein-protein intermolecular interactions that can be modulated with solution ionic strength. We studied a therapeutic monoclonal antibody that exhibits high viscosity in solutions at low ionic strength (~20 centipoise (cP) at 90 mg/mL and 23°C) and significant opalescence at isotonic ionic strength (approximately 100 nephelometric turbidity units at 90 mg/mL and...

Pipeline flow of heavy oil with temperature-dependent viscosity

Energy Technology Data Exchange (ETDEWEB)

Maza Quinones, Danmer; Carvalho, Marcio da Silveira [Pontifical Catholic University of Rio de Janeiro (PUC-Rio), RJ (Brazil). Dept. of Mechanical Engineering], E-mail: msc@puc-rio.br

2010-07-01

The heavy oil produced offshore needs to be transported through pipelines between different facilities. The pipelines are usually laid down on the seabed and are submitted to low temperatures. Although heavy oils usually present Newtonian behavior, its viscosity is a strong function of temperature. Therefore, the prediction of pressure drops along the pipelines should include the solution of the energy equation and the dependence of viscosity to temperature. In this work, an asymptotic model is developed to study this problem. The flow is considered laminar and the viscosity varies exponentially with temperature. The model includes one-dimensional equations for the temperature and pressure distribution along the pipeline at a prescribed flow rate. The solution of the coupled differential equation is obtained by second-order finite difference. Results show a nonlinear behavior as a result of coupled interaction between the velocity, temperature, and temperature dependent material properties. (author)

Measurement of the Surface Dilatational Viscosity of an Insoluble Surfactant Monolayer at the Air/Water Interface Using a Pendant Drop Apparatus

Science.gov (United States)

Lorenzo, Jose; Couzis, Alex; Maldarelli, Charles; Singh, Bhim S. (Technical Monitor)

2000-01-01

When a fluid interface with surfactants is at rest, the interfacial stress is isotropic (as given by the equilibrium interfacial tension), and is described by the equation of state which relates the surface tension to the surfactant surface concentration. When surfactants are subjected to shear and dilatational flows, flow induced interaction of the surfactants; can create interfacial stresses apart from the equilibrium surface tension. The simplest relationship between surface strain rate and surface stress is the Boussinesq-Scriven constitutive equation completely characterized by three coefficients: equilibrium interfacial tension, surface shear viscosity, and surface dilatational viscosity Equilibrium interfacial tension and surface shear viscosity measurements are very well established. On the other hand, surface dilatational viscosity measurements are difficult because a flow which change the surface area also changes the surfactant surface concentration creating changes in the equilibrium interfacial tension that must be also taken into account. Surface dilatational viscosity measurements of existing techniques differ by five orders of magnitude and use spatially damped surface waves and rapidly expanding bubbles. In this presentation we introduce a new technique for measuring the surface dilatational viscosity by contracting an aqueous pendant drop attached to a needle tip and having and insoluble surfactant monolayer at the air-water interface. The isotropic total tension on the surface consists of the equilibrium surface tension and the tension due to the dilation. Compression rates are undertaken slow enough so that bulk hydrodynamic stresses are small compared to the surface tension force. Under these conditions we show that the total tension is uniform along the surface and that the Young-Laplace equation governs the drop shape with the equilibrium surface tension replaced by the constant surface isotropic stress. We illustrate this technique using

Viscosity and Electrical Conductivity of Concentrated Solutions of Soluble Coffee

Czech Academy of Sciences Publication Activity Database

Sobolík, Václav; Žitný, R.; Tovčigrečko, Valentin; Delgado, M.; Allaf, K.

2002-01-01

Roč. 51, č. 2 (2002), s. 93-98 ISSN 0260-8774 Institutional research plan: CEZ:AV0Z4072921; CEZ:MSM 212200008 Keywords : coffee extract * soluble coffee * viscosity Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.085, year: 2002

Resolution in QCM sensors for the viscosity and density of liquids: application to lead acid batteries.

Science.gov (United States)

Cao-Paz, Ana María; Rodríguez-Pardo, Loreto; Fariña, José; Marcos-Acevedo, Jorge

2012-01-01

In battery applications, particularly in automobiles, submarines and remote communications, the state of charge (SoC) is needed in order to manage batteries efficiently. The most widely used physical parameter for this is electrolyte density. However, there is greater dependency between electrolyte viscosity and SoC than that seen for density and SoC. This paper presents a Quartz Crystal Microbalance (QCM) sensor for electrolyte density-viscosity product measurements in lead acid batteries. The sensor is calibrated in H(2)SO(4) solutions in the battery electrolyte range to obtain sensitivity, noise and resolution. Also, real-time tests of charge and discharge are conducted placing the quartz crystal inside the battery. At the same time, the present theoretical "resolution limit" to measure the square root of the density-viscosity product [Formula: see text] of a liquid medium or best resolution achievable with a QCM oscillator is determined. Findings show that the resolution limit only depends on the characteristics of the liquid to be studied and not on frequency. The QCM resolution limit for [Formula: see text] measurements worsens when the density-viscosity product of the liquid is increased, but it cannot be improved by elevating the work frequency.

Effect of calcium chelators on physical changes in casein micelles in concentrated micellar casein solutions

NARCIS (Netherlands)

Kort, de E.J.P.; Minor, M.; Snoeren, T.H.M.; Hooijdonk, van A.C.M.; Linden, van der E.

2011-01-01

The effect of calcium chelators on physical changes of casein micelles in concentrated micellar casein solutions was investigated by measuring calcium-ion activity, viscosity and turbidity, and performing ultracentrifugation. The highest viscosities were measured on addition of sodium

Regression and Sparse Regression Methods for Viscosity Estimation of Acid Milk From it’s Sls Features

DEFF Research Database (Denmark)

Sharifzadeh, Sara; Skytte, Jacob Lercke; Nielsen, Otto Højager Attermann

2012-01-01

Statistical solutions find wide spread use in food and medicine quality control. We investigate the effect of different regression and sparse regression methods for a viscosity estimation problem using the spectro-temporal features from new Sub-Surface Laser Scattering (SLS) vision system. From...... with sparse LAR, lasso and Elastic Net (EN) sparse regression methods. Due to the inconsistent measurement condition, Locally Weighted Scatter plot Smoothing (Loess) has been employed to alleviate the undesired variation in the estimated viscosity. The experimental results of applying different methods show...

Thermodynamic study on some alkanediol solutions: Measurement and modeling

International Nuclear Information System (INIS)

Moosavi, Mehrdad; Motahari, Ahmad; Omrani, Abdollah; Rostami, Abbas Ali

2013-01-01

Highlights: • Measuring densities and viscosities for binary mixtures of some alkanediols. • Finding excess molar volume, partial molar volume and thermal expansion coefficient. • Fitting excess molar volume values with PFP and Redlich–Kister polynomial equations. • Deducing excess Gibbs free energy of activation and other thermodynamic parameters. • Predicting viscosity values with different single parameter semi empirical equations. - Abstract: The densities ρ and viscosities η of 1,2-ethanediol with 1,2-propanediol or 1,3-propanediol, and 1,2-propanediol with 1,3-propanediol binary liquid mixtures over the entire concentration range at temperatures (298.15 to 308.15) K with 5 K interval were measured. The experimental data were used to calculate the excess molar volume V m E , partial molar volume V ¯ m,i , partial molar volume at infinite dilution V ¯ i ∞ , apparent molar volume V φi , coefficient of thermal expansion α p , excess coefficient of thermal expansion α p E , excess viscosity η E , excess Gibbs energy of activation ΔG *E , and other thermodynamic parameters. A Redlich–Kister equation and Prigogine–Flory–Patterson (PFP) model was applied to correlate the excess molar volume results. Moreover, the viscosity data were correlated with the Grunberg–Nissan, Tamura–Kurata, Hind–Ubbelohde and Katti–Chaudhary equations. Good agreement was found between experimental data and modeling results

Evaluation of stability and viscosity measurement of emulsion from oil from production in northern oilfield in Thailand

Science.gov (United States)

Juntarasakul, O.; Maneeintr, K.

2018-04-01

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.

Irradiated pepper and ginger detected by viscosity and starch measurements

International Nuclear Information System (INIS)

Wegmueler, F.; Meier, W.

1999-01-01

Starch and rheological measurements of alkaline suspensions of white pepper, black pepper and ginger are a useful tool to distinguish not irradiated samples from the gamma-treated spices (dose gtoreq 2 kGy). In addition it is shown that starch is not the material which determines the different rheological behaviour of the alkaline suspensions of the spices. The differences in the viscosity data are rather due to irradiation damages of polymers which are enriched in the cell wall material of the pepper grains and the roots of the ginger

Rational design of viscosity reducing mutants of a monoclonal antibody: hydrophobic versus electrostatic inter-molecular interactions.

Science.gov (United States)

Nichols, Pilarin; Li, Li; Kumar, Sandeep; Buck, Patrick M; Singh, Satish K; Goswami, Sumit; Balthazor, Bryan; Conley, Tami R; Sek, David; Allen, Martin J

2015-01-01

High viscosity of monoclonal antibody formulations at concentrations ≥100 mg/mL can impede their development as products suitable for subcutaneous delivery. The effects of hydrophobic and electrostatic intermolecular interactions on the solution behavior of MAB 1, which becomes unacceptably viscous at high concentrations, was studied by testing 5 single point mutants. The mutations were designed to reduce viscosity by disrupting either an aggregation prone region (APR), which also participates in 2 hydrophobic surface patches, or a negatively charged surface patch in the variable region. The disruption of an APR that lies at the interface of light and heavy chain variable domains, VH and VL, via L45K mutation destabilized MAB 1 and abolished antigen binding. However, mutation at the preceding residue (V44K), which also lies in the same APR, increased apparent solubility and reduced viscosity of MAB 1 without sacrificing antigen binding or thermal stability. Neutralizing the negatively charged surface patch (E59Y) also increased apparent solubility and reduced viscosity of MAB 1, but charge reversal at the same position (E59K/R) caused destabilization, decreased solubility and led to difficulties in sample manipulation that precluded their viscosity measurements at high concentrations. Both V44K and E59Y mutations showed similar increase in apparent solubility. However, the viscosity profile of E59Y was considerably better than that of the V44K, providing evidence that inter-molecular interactions in MAB 1 are electrostatically driven. In conclusion, neutralizing negatively charged surface patches may be more beneficial toward reducing viscosity of highly concentrated antibody solutions than charge reversal or aggregation prone motif disruption.

A Deoxyuridine-Based Far-Red Emitting Viscosity Sensor.

Science.gov (United States)

Wang, Mengyuan; Zhang, Yuanwei; Yue, Xiling; Yao, Sheng; Bondar, Mykhailo V; Belfield, Kevin D

2016-05-30

A novel deoxyuridine (dU) benzothiazolium (BZ) derivative, referred to as dU-BZ, is reported that was synthesized via Sonogashira coupling reaction methodology. The deoxyuridine building block was introduced to enhance hydrophilicity, while an alkynylated benzothiazolium dye was incorporated for long wavelength absorption to reduce potential phototoxicity that is characteristic of using UV light to excite common fluorphores, better discriminate from native autofluorescence, and potentially facilitate deep tissue imaging. An impressive 30-fold enhancement of fluorescence intensity of dU-BZ was achieved upon increasing viscosity. Fluorescence quantum yields in 99% glycerol/1% methanol (v/v) solution as a function of temperature (293-343 K), together with viscosity-dependent fluorescence lifetimes and radiative and non-radiative rate constants in glycerol/methanol solutions (ranging from 4.8 to 950 cP) were determined. Both fluorescence quantum yields and lifetimes increased with increased viscosity, consistent with results predicted by theory. This suggests that the newly-designed compound, dU-BZ, is capable of functioning as a probe of local microviscosity, an aspect examined by in vitro bioimaging experiments.

A Deoxyuridine-Based Far-Red Emitting Viscosity Sensor

Directory of Open Access Journals (Sweden)

Mengyuan Wang

2016-05-01

Full Text Available A novel deoxyuridine (dU benzothiazolium (BZ derivative, referred to as dU-BZ, is reported that was synthesized via Sonogashira coupling reaction methodology. The deoxyuridine building block was introduced to enhance hydrophilicity, while an alkynylated benzothiazolium dye was incorporated for long wavelength absorption to reduce potential phototoxicity that is characteristic of using UV light to excite common fluorphores, better discriminate from native autofluorescence, and potentially facilitate deep tissue imaging. An impressive 30-fold enhancement of fluorescence intensity of dU-BZ was achieved upon increasing viscosity. Fluorescence quantum yields in 99% glycerol/1% methanol (v/v solution as a function of temperature (293–343 K, together with viscosity-dependent fluorescence lifetimes and radiative and non-radiative rate constants in glycerol/methanol solutions (ranging from 4.8 to 950 cP were determined. Both fluorescence quantum yields and lifetimes increased with increased viscosity, consistent with results predicted by theory. This suggests that the newly-designed compound, dU-BZ, is capable of functioning as a probe of local microviscosity, an aspect examined by in vitro bioimaging experiments.

Measurements and correlation of viscosities and conductivities for the mixtures of ethylammonium nitrate with organic solvents

International Nuclear Information System (INIS)

Litaeim, Yousra; Zarrougi, Ramzi; Dhahbi, Mahmoud

2009-01-01

Room temperature ionic liquids (IL) as a new class of organic molten salts have been considered as an alternative of traditional organic solvents (OS). The physico-chemical transport properties of mixtures IL/OS were investigated and described by ion-ion, ion solvent and solvent-solvent interactions. Ethylammonium nitrate (EAN) was studied in presence of two types of organic solvents: the dimethyl carbonate (DMC) and the formamide (FA). The variation of the viscosity with salt concentration and temperature shows that EAN ions behave as a structure breaker for the DMC. However, no effect was recorded in the case of FA. Concentrated electrolyte solutions behave as very structured media and checked a theory of pseudo-lattice. The existence of a conductivity maximum indicates two competing effects; the increasing number of charge carriers and the higher viscosity of the electrolyte as the salt concentration was raised. The use of the Walden product to investigate ionic interactions of EAN with both solvents was discussed. A study of the effect of temperature on the conductivity and viscosity reveals that both systems (EAN/DMC and EAN/FA) obey an Arrhenius low. The activation energies for the tow transport process (Ea,L and Ea,h) as a function of the salt concentration were evaluated.

VISCOSE BASED MAGNETIC YARNS – PHYSICAL AND MECHANICAL CHARACTERIZATION

Directory of Open Access Journals (Sweden)

GROSU Marian-Cătălin

2017-05-01

Full Text Available In the context of the rapid growth in the number of electrical and electronic devices and accessories that emit electromagnetic energy in different frequency bands we present and characterize here several magnetic functionalized viscose twisted yarns. A 100% viscose twisted staple yarn was covered through an in-house developed process with a polymeric solution containing micrometric sized barium hexaferrite magnetic powder. The in-house developed process allows deposition of micrometric thickness polymeric paste layer on the yarn surface. Barium hexaferrite is a hard magnetic material exhibiting high chemical stability and corrosion resistivity, relatively large saturation and residual magnetization and microwave absorbing properties. Five different percentages of the magnetic powder in the polymer solution were used, i.e. ranging from 15 wt% to 45 wt%. Physical characterization shows a very good adherence between the highly hygroscopic viscose staple fibers and the polymeric solution that contains polyvinyl acetate and polyurethane as binders. SEM images evidenced the fact that the polymeric solution penetrated more than 1/3 of the yarn diameter. The concentration of magnetic powder in the polymeric solution has a direct influence on the coating amount, diameter and density. The mechanical characterization of the coated yarns revealed that the breaking force is increasing with increasing magnetic powder content up to o certain value and then decreased because the magnetic layer became stiffer. At the same time, the elongation at brake is decreasing.

Measurement and study of density, surface tension, and viscosity of quaternary ammonium-based ionic liquids ([N222(n)]Tf2N)

International Nuclear Information System (INIS)

Ghatee, Mohammad Hadi; Bahrami, Maryam; Khanjari, Neda

2013-01-01

Highlights: • Characterization of high purity synthesized alkyl quaternary ammonium ionic liquids. • Measurement of temperature dependent surface tension, density, viscosity and critical point. • Systematic increase of surface energy and surface entropy having plateau at high chain length. • Accurate application of VFT and fluidity equations to temperature dependent viscosities. • Particular variation of fluidity exponent with a plateau at high alkyl chain length. -- Abstract: In this work five quaternary ammonium-based ionic liquids with bis(trifluoromethylsulfonyl)imide anion were synthesized and their density, viscosity and surface tensions were measured in the temperature range (298 to 373) K. Surface tensions were measured by capillary rise method using a homemade capillary apparatus, in which the liquid/vapor can be brought into equilibrium practically. Measurements of viscosities and surface tensions were performed under water–vapor free atmosphere. The surface tension of quaternary ammonium-based ILs decreases as the alkyl chain length increases. Also surface energy and surface entropy are found as increasing functions of alkyl chain length with a plateau at high lengths in the surface. The viscosities measured by capillary viscometer fit in VFT equation, indication of non-Arrhenius ionic liquids. Viscosities are also fitted quite accurately in the relation we have developed recently as the fluidity equation with the characteristics exponent ϕ. Values of ϕ for ionic liquids are close to one another and tend to the limiting value, almost 0.328, asymptotically as the alkyl chain length increases. The critical temperatures predicted via the temperature dependent surface tensions decrease with increasing alkyl chain length of the cation. The trend of predicted critical temperature of these ionic liquids conforms to those of imidazolium-based ILs

Thermodynamic study on some alkanediol solutions: Measurement and modeling

Energy Technology Data Exchange (ETDEWEB)

Moosavi, Mehrdad; Motahari, Ahmad; Omrani, Abdollah, E-mail: omrani@umz.ac.ir; Rostami, Abbas Ali

2013-06-10

Highlights: • Measuring densities and viscosities for binary mixtures of some alkanediols. • Finding excess molar volume, partial molar volume and thermal expansion coefficient. • Fitting excess molar volume values with PFP and Redlich–Kister polynomial equations. • Deducing excess Gibbs free energy of activation and other thermodynamic parameters. • Predicting viscosity values with different single parameter semi empirical equations. - Abstract: The densities ρ and viscosities η of 1,2-ethanediol with 1,2-propanediol or 1,3-propanediol, and 1,2-propanediol with 1,3-propanediol binary liquid mixtures over the entire concentration range at temperatures (298.15 to 308.15) K with 5 K interval were measured. The experimental data were used to calculate the excess molar volume V{sub m}{sup E}, partial molar volume V{sup ¯}{sub m,i}, partial molar volume at infinite dilution V{sup ¯}{sub i}{sup ∞}, apparent molar volume V{sub φi}, coefficient of thermal expansion α{sub p}, excess coefficient of thermal expansion α{sub p}{sup E}, excess viscosity η{sup E}, excess Gibbs energy of activation ΔG{sup *E}, and other thermodynamic parameters. A Redlich–Kister equation and Prigogine–Flory–Patterson (PFP) model was applied to correlate the excess molar volume results. Moreover, the viscosity data were correlated with the Grunberg–Nissan, Tamura–Kurata, Hind–Ubbelohde and Katti–Chaudhary equations. Good agreement was found between experimental data and modeling results.

In vitro evaluation of the erosive potential of viscosity-modified soft acidic drinks on enamel.

Science.gov (United States)

Aykut-Yetkiner, Arzu; Wiegand, Annette; Ronay, Valerie; Attin, Rengin; Becker, Klaus; Attin, Thomas

2014-04-01

The objective of this in vitro study was to investigate the effect of viscosity-modified soft acidic drinks on enamel erosion. A total of 108 bovine enamel samples (∅ = 3 mm) were embedded in acrylic resin and allocated into six groups (n = 18). Soft acidic drinks (orange juice, Coca-Cola, Sprite) were used both in their regular forms and at a kinetic viscositiy of 5 mm(2)/s, which was adjusted by adding hydroxypropyl cellulose. All solutions were pumped over the enamel surface from a reservoir with a drop rate of 3 ml/min. Each specimen was eroded for 10 min at 20 °C. Erosion of enamel surfaces was measured using profilometry. Data were analyzed using independent t tests and one-way ANOVAs (p Coca-Cola, 5.60 ± 1.04 μm; Sprite, 5.49 ± 0.94 μm; orange juice, 1.35 ± 0.4 μm) than for the viscosity-modified drinks (Coca-Cola, 4.90 ± 0.34 μm; Sprite, 4.46 ± 0.39 μm; orange juice, 1.10 ± 0.22 μm). For both regular and viscosity-modified forms, Coca-Cola and Sprite caused higher enamel loss than orange juice. Increasing the viscosity of acidic soft drinks to 5 mm(2)/s reduced enamel erosion by 12.6-18.7 %. The erosive potential of soft acidic drinks is not only dependent on various chemical properties but also on the viscosity of the acidic solution and can be reduced by viscosity modification.

Coherent Rayleigh-Brillouin scattering measurements of bulk viscosity of polar and nonpolar gases, and kinetic theory

NARCIS (Netherlands)

Meijer, A.S.; Wijn, de A.S.; Peters, M.F.E.; Dam, N.J.; Water, van de W.

2010-01-01

We investigate coherent Rayleigh–Brillouin spectroscopy as an efficient process to measure the bulk viscosity of gases at gigahertz frequencies. Scattered spectral distributions are measured using a Fizeau spectrometer. We discuss the statistical error due to the fluctuating mode structure of the

VISCOSITY TEST OF VEHICLE ENGINE OILS

OpenAIRE

Rita Prasetyowati

2016-01-01

This study aims to determine the value of the kinematic viscosity lubricants motorcycle that has been used at various temperatures and the use of distance. This study also aims to remedy mengtahui how the value of the kinematic viscosity of the lubricant car that has been used in a wide range of temperature variation and distance usage. Viscosity liquid, in this case is the lubricants, can be determined using the Redwood viscometer By using Redwood viscometer, can be measured flow time requir...

Shear viscosity enhancement in water–nanoparticle suspensions

International Nuclear Information System (INIS)

Balasubramanian, Ganesh; Sen, Swarnendu; Puri, Ishwar K.

2012-01-01

Equilibrium molecular dynamics simulations characterize the increase in the shear viscosity of water around a suspended silicon dioxide nanoparticle. Water layering on the solid surface decreases the fraction of adjacent fluid molecules that are more mobile and hence less viscous, thereby increasing the shear viscosity. The contribution of the nanoparticle surface area to this rheological behavior is identified and an empirical model that accounts for it is provided. The model successfully reproduces the shear viscosity predictions from previous experimental measurements as well as our simulations. -- Highlights: ► Layering of water on the solid surfaces increases the fraction of less mobile molecules adjacent to them. ► A nondimensional parameter predicts of viscosity enhancement due to particle shape, volume fraction. ► Model predictions agree with the results of atomistic simulations and experimental measurements.

Uniaxial Elongational viscosity of bidisperse polystyrene melts

DEFF Research Database (Denmark)

Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole

2006-01-01

The startup and steady uniaxial elongational viscosity have been measured for three bidisperse polystyrene (PS) melts, consisting of blends of monodisperse PS with molecular weights of 52 kg/mole or 103 kg/mole and 390 kg/mole. The bidisperse melts have a maximum in the steady elongational...... viscosity, of up to a factor of 7 times the Trouton limit of 3 times the zero-shear viscosity....

Determination of viscosity in recirculating fluidized bed using radioactive tracer

International Nuclear Information System (INIS)

Silva, G.G. da.

1986-01-01

The use of radioactive tracer for measuring viscosity is proposed. The methodology relates the terminal velocity of a radioactive sphere in interior of fluid with the viscosity, which can be a fluidized bed or total flow of solids. The arrangement is composed by two γ detectors placed externally and along the bed. Both detectors are coupled by amplifier to electronic clock. The drop time of sphere between two detectors is measured. The bed viscosity two detectors is measured. The bed viscosity is calculated from mathematical correlations of terminal velocity of the sphere. (M.C.K.)

Viscosity of liquid sulfur under high pressure

International Nuclear Information System (INIS)

Terasaki, Hidenori; Kato, T; Funakoshi, K; Suzuki, A; Urakawa, S

2004-01-01

The viscosity of liquid sulfur up to 9.7 GPa and 1067 K was measured using the in situ x-ray radiography falling sphere method. The viscosity coefficients were found to range from 0.11 to 0.69 Pa s, and decreased continuously with increasing pressure under approximately constant homologous temperature conditions. The observed viscosity variation suggests that a gradual structural change occurs in liquid sulfur with pressure up to 10 GPa. The L-L' transition in liquid sulfur proposed by Brazhkin et al (1991 Phys. Lett. A 154 413) from thermobaric measurements has not been confirmed by the present viscometry

Comparing Two Methods of Neural Networks to Evaluate Dead Oil Viscosity

Directory of Open Access Journals (Sweden)

Meysam Dabiri-Atashbeyk

2018-01-01

Full Text Available Reservoir characterization and asset management require comprehensive information about formation fluids. In fact, it is not possible to find accurate solutions to many petroleum engineering problems without having accurate pressure-volume-temperature (PVT data. Traditionally, fluid information has been obtained by capturing samples and then by measuring the PVT properties in a laboratory. In recent years, neural network has been applied to a large number of petroleum engineering problems. In this paper, a multi-layer perception neural network and radial basis function network (both optimized by a genetic algorithm were used to evaluate the dead oil viscosity of crude oil, and it was found out that the estimated dead oil viscosity by the multi-layer perception neural network was more accurate than the one obtained by radial basis function network.

Magnetically-charged black branes and viscosity/entropy ratios

Energy Technology Data Exchange (ETDEWEB)

Liu, Hai-Shan [Institute for Advanced Physics & Mathematics,Zhejiang University of Technology, Hangzhou 310023 (China); George P. & Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy,Texas A& M University, College Station, TX 77843 (United States); Lü, H. [Department of Physics, Beijing Normal University,Beijing 100875 (China); Pope, C.N. [George P. & Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy,Texas A& M University, College Station, TX 77843 (United States); DAMTP, Centre for Mathematical Sciences,Cambridge University, Wilberforce Road, Cambridge CB3 OWA (United Kingdom)

2016-12-19

We consider asymptotically-AdS n-dimensional black brane solutions in a theory of gravity coupled to a set of Np-form field strengths, in which the field strengths carry magnetic charges. For appropriately chosen charges, the metrics are isotropic in the (n−2) transverse directions. However, in general the field strength configurations break the full Euclidean symmetry of the (n−2)-dimensional transverse space, and the shear viscosity tensor in the dual theory is no longer isotropic. We study the linearised equations for transverse traceless metric perturbations in these backgrounds, and by employing the Kubo formula we obtain expressions for the ratios η/S of the shear viscosity components divided by the entropy density. We find that the KSS bound on the ratios η/S is generally violated in these solutions. We also extend the discussion by including a dilatonic scalar field in the theory, leading to solutions that are asymptotically Lifshitz with hyperscaling violation.

Viscosity measurements - a comprehensive overview on the method and its applicability for the identification of irradiated foodstuffs

International Nuclear Information System (INIS)

Nuernberger, E.; Heide, L.; Boegl, K.W.

1991-01-01

The viscosity of a foodstuff depends mainly on the composition and the amount of starch, pectins and cellulose, which may undergo changes after irradiation. The investigation on the applicability of viscosity measurement for the identification of irradiated foods showed so far that this method seems to be applicable only to a definite number of spices and foods. The optimal method has to be determined empirically, because the reason is still unknown, why in some cases, the viscosity values decrease and in other cases increase after irradiation - and why sometimes no changes occur at all. Until now, the following irradiated spices can be identified by this method: cardamom, cinnamon, curcuma, horse-radish, nutmeg, mustard-seed and white pepper. (21 figs, 2 tabs, 10 refs)

Glasslike behavior in aqueous electrolyte solutions.

Science.gov (United States)

Turton, David A; Hunger, Johannes; Hefter, Glenn; Buchner, Richard; Wynne, Klaas

2008-04-28

When salts are added to water, generally the viscosity increases, suggesting that the ions increase the strength of the water's hydrogen-bond network. However, infrared pump-probe measurements on electrolyte solutions have found that ions have no influence on the rotational dynamics of water molecules, implying no enhancement or breakdown of the hydrogen-bond network. Here, we report optical Kerr effect and dielectric relaxation spectroscopic measurements, which have enabled us to separate the effects of rotational and transitional motions of the water molecules. These data show that electrolyte solutions behave like a supercooled liquid approaching a glass transition in which rotational and translational molecular motions are decoupled. It is now possible to understand previously conflicting viscosity data, nuclear magnetic resonance relaxation, and ultrafast infrared spectroscopy in a single unified picture.

Experimental study of the density and viscosity of 1-ethyl-3-methylimidazolium ethyl sulfate

International Nuclear Information System (INIS)

Schmidt, H.; Stephan, M.; Safarov, J.; Kul, I.; Nocke, J.; Abdulagatov, I.M.; Hassel, E.

2012-01-01

Highlights: ► Density of the ionic liquid [EMIM][EtSO 4 ]. ► Viscosity of the ionic liquid [EMIM][EtSO 4 ]. ► Thermodynamic properties of ionic liquid [EMIM][EtSO 4 ]. ► Equation of state of ionic liquid [EMIM][EtSO 4 ]. - Abstract: Density and viscosity of 1-ethyl-3-methylimidazolium ethyl sulfate [EMIM][EtSO 4 ] have been measured over the temperature range from (283.15 to 413.15) K and at pressures up to 140 MPa and in the temperature range from (283.15 to 373.15) K at 0.1 MPa, respectively. The expanded uncertainty of the density, pressure, temperature, and viscosity measurements at the 95% confidence level with a coverage factor of k = 2 is estimated to be (0.01 to 0.08)%, 0.1%, 15 mK, and 0.35%, respectively. The measurements were carried out with an Anton–Paar DMA HPM vibration-tube densimeter and a fully automated SVM 3000 Anton–Paar rotational Stabinger viscometer. The vibration-tube densimeter was calibrated using various reference fluids, double-distilled water, methanol, toluene, and aqueous NaCl solutions. An empiric equation of state for [EMIM][EtSO 4 ] has been developed using the measured (p, ρ, T) data. This equation was used to calculate the various thermodynamic properties of the IL and for compare with measured properties (speed of sound and enthalpy). Theoretically based Arrhenius–Andrade and Vogel–Tamman–Fulcher type equations were use to describe of the temperature dependence of measured viscosities for [EMIM][EtSO 4 ]. All measured properties were detailed compared with the reported data by other author.

Resolution in QCM Sensors for the Viscosity and Density of Liquids: Application to Lead Acid Batteries

Directory of Open Access Journals (Sweden)

Jorge Marcos-Acevedo

2012-08-01

Full Text Available In battery applications, particularly in automobiles, submarines and remote communications, the state of charge (SoC is needed in order to manage batteries efficiently. The most widely used physical parameter for this is electrolyte density. However, there is greater dependency between electrolyte viscosity and SoC than that seen for density and SoC. This paper presents a Quartz Crystal Microbalance (QCM sensor for electrolyte density-viscosity product measurements in lead acid batteries. The sensor is calibrated in H₂SO₄ solutions in the battery electrolyte range to obtain sensitivity, noise and resolution. Also, real-time tests of charge and discharge are conducted placing the quartz crystal inside the battery. At the same time, the present theoretical “resolution limit” to measure the square root of the density-viscosity product ( of a liquid medium or best resolution achievable with a QCM oscillator is determined. Findings show that the resolution limit only depends on the characteristics of the liquid to be studied and not on frequency. The QCM resolution limit for  measurements worsens when the density-viscosity product of the liquid is increased, but it cannot be improved by elevating the work frequency.

Control of radio degradation of natural polymers by measurement of viscosity and molecular weight determination

International Nuclear Information System (INIS)

Nabinger Machado, Patricia; Cerchietti, Maria Luciana; Mondino, Angel V.; Smolko, Eduardo E.

2009-01-01

Applications are now being made in various fields of oligosaccharides obtained by the depolymerization of large molecules such as natural alginates, carrageenan, pectin and chitosan. Find use in various disciplines such as crop production, sanitation, pharmacy, cosmetics, etc. Given the diversity of origins of these materials, almost all of marine origin, was the need for universal methods for recognition and composition, then the possible ways to get processed. A centralized program by the IAEA is promoting the use of ionizing radiation for these changes. This paper resents the calculations used to obtain the molecular weight of polysaccharides from determinations of viscosity. It has been found the molecular weight of sodium alginate and kappa-carrageenan irradiated with cobalt-60 gamma rays at doses between 2 and 35 kGy in solid state. We used a capillary Cannon Viscometer Ubbelohde-type and a protocol for standardized calculation procedure for this purpose. Were obtained reading times for passage through the capillary Viscometer, with various concentrations of polymer solutions of virgin material and the irradiated and from there calculated the relative viscosities, specific, inherent, reduced and intrinsic and then using the ratio of Mark-Houwink-SAKURADA calculate the viscosity average molecular weight of the different polymers. The changes found in the molecular weights by radio-depolymerization reach two orders of magnitude in some cases giving oligosaccharides of 8-12 monomer units. It is considered that this depolymerization method is effective and inexpensive compared to enzymatic or chemical methods. (author)

Experimental evidence of the role of viscosity in the molecular kinetic theory of dynamic wetting.

Science.gov (United States)

Duvivier, D; Seveno, D; Rioboo, R; Blake, T D; De Coninck, J

2011-11-01

We report an experimental study of the dynamics of spontaneous spreading of aqueous glycerol drops on glass. For a range of glycerol concentrations, we follow the evolution of the radius and contact angle over several decades of time and investigate the influence of solution viscosity. The application of the molecular kinetic theory to the resulting data allows us to extract the coefficient of contact-line friction ζ, the molecular jump frequency κ(0), and the jump length λ for each solution. Our results show that the modified theory, which explicitly accounts for the effect of viscosity, can successfully be applied to droplet spreading. The viscosity affects the jump frequency but not the jump length. In combining these data, we confirm that the contact-line friction of the solution/air interface against the glass is proportional to the viscosity and exponentially dependent on the work of adhesion.

The determination of the pressure-viscosity coefficient of two traction oils using film thickness measurements

NARCIS (Netherlands)

Leeuwen, van H.J.

2010-01-01

The pressure-viscosity coefficients of two commercial traction fluids are determined by fitting calculation results on accurate film thickness measurements, obtained at a wide range of speeds, and different temperatures. Film thickness values are calculated using a numerical method and approximation

Viscosity of iodinated contrast agents during renal excretion

International Nuclear Information System (INIS)

Jost, Gregor; Lengsfeld, Philipp; Lenhard, Diana C.; Pietsch, Hubertus; Huetter, Joachim; Sieber, Martin A.

2011-01-01

Objective: Modern iodinated non-ionic contrast agents (CAs) can be classified based on their molecular structure into monomeric and dimeric CAs and have at comparable iodine concentrations a different viscosity and osmolality. During their renal excretion, CAs are concentrated in the renal tubuli which might enhance the viscosity difference between monomeric and dimeric CAs. The viscosity of a CA might have an underestimated importance for renal safety, as suggested by recent publications. In this study, we investigated the viscosities of CAs at the concentrations expected to be present in renal tubules. This concentration process was simulated in vitro using dialysis. Furthermore, we investigated urine viscosity and urine flow in rodents after administration of several non-ionic monomeric and dimeric CAs. Materials and methods: To estimate the viscosity of the CAs in vivo, we performed an in vitro dialysis of monomeric and dimeric CAs at various physiological osmolalities of the renal tubulus (290, 400, 500, 700 and 1000 mOsm/kg H 2 O). Following the dialysis, the iodine concentrations and the viscosities of the CAs were determined. Furthermore, to investigate the concentration process in vivo, we measured the urine viscosity and the urine flow in Han Wister rats after the administration of Iopromide, Iohexol, Ioversol, Iomeprol, Iodixanol, and Iosimenol at comparable iodine concentrations. As a control, saline was injected at the same volume. Results: In vitro dialysis of the dimeric CA increased the iodine concentration and strongly increased the viscosity at all tested osmolalities. In contrast, for the monomeric agents an increase in concentration and viscosity was observed only at 700 as well 1000 mOsm/kg H 2 O but to a lesser extent. In summary, dialysis strongly enhanced the viscosity differences between the non-ionic monomeric and dimeric CAs. The administration of dimeric CAs leads to a strong increase in urine viscosity; this was not observed for the

Viscosity of iodinated contrast agents during renal excretion

Energy Technology Data Exchange (ETDEWEB)

Jost, Gregor, E-mail: Gregor.Jost@bayer.com [TRG Diagnostic Imaging, Bayer Schering Pharma AG, Berlin (Germany); Lengsfeld, Philipp, E-mail: Philipp.Lengsfeld@bayer.com [Global Medical Affairs Diagnostic Imaging, Bayer Schering Pharma AG, Berlin (Germany); Lenhard, Diana C., E-mail: Diana.Lenhard@bayer.com [TRG Diagnostic Imaging, Bayer Schering Pharma AG, Berlin (Germany); Pietsch, Hubertus, E-mail: Hubertus.Pietsch@bayer.com [TRG Diagnostic Imaging, Bayer Schering Pharma AG, Berlin (Germany); Huetter, Joachim, E-mail: Joachim.Huetter@bayer.com [TRG Diagnostic Imaging, Bayer Schering Pharma AG, Berlin (Germany); Sieber, Martin A., E-mail: Martin.Sieber@bayer.com [TRG Diagnostic Imaging, Bayer Schering Pharma AG, Berlin (Germany)

2011-11-15

Objective: Modern iodinated non-ionic contrast agents (CAs) can be classified based on their molecular structure into monomeric and dimeric CAs and have at comparable iodine concentrations a different viscosity and osmolality. During their renal excretion, CAs are concentrated in the renal tubuli which might enhance the viscosity difference between monomeric and dimeric CAs. The viscosity of a CA might have an underestimated importance for renal safety, as suggested by recent publications. In this study, we investigated the viscosities of CAs at the concentrations expected to be present in renal tubules. This concentration process was simulated in vitro using dialysis. Furthermore, we investigated urine viscosity and urine flow in rodents after administration of several non-ionic monomeric and dimeric CAs. Materials and methods: To estimate the viscosity of the CAs in vivo, we performed an in vitro dialysis of monomeric and dimeric CAs at various physiological osmolalities of the renal tubulus (290, 400, 500, 700 and 1000 mOsm/kg H{sub 2}O). Following the dialysis, the iodine concentrations and the viscosities of the CAs were determined. Furthermore, to investigate the concentration process in vivo, we measured the urine viscosity and the urine flow in Han Wister rats after the administration of Iopromide, Iohexol, Ioversol, Iomeprol, Iodixanol, and Iosimenol at comparable iodine concentrations. As a control, saline was injected at the same volume. Results: In vitro dialysis of the dimeric CA increased the iodine concentration and strongly increased the viscosity at all tested osmolalities. In contrast, for the monomeric agents an increase in concentration and viscosity was observed only at 700 as well 1000 mOsm/kg H{sub 2}O but to a lesser extent. In summary, dialysis strongly enhanced the viscosity differences between the non-ionic monomeric and dimeric CAs. The administration of dimeric CAs leads to a strong increase in urine viscosity; this was not observed for

Viscosity of Heterogeneous Silicate Melts: A Non-Newtonian Model

Science.gov (United States)

Liu, Zhuangzhuang; Blanpain, Bart; Guo, Muxing

2017-12-01

The recently published viscosity data of heterogeneous silicate melts with well-documented structure and experimental conditions are critically re-analyzed and tabulated. By using these data, a non-Newtonian viscosity model incorporating solid fraction, solid shape, and shear rate is proposed on the basis of the power-law equation. This model allows calculating the viscosity of the heterogeneous silicate melts with solid fraction up to 34 vol pct. The error between the calculated and measured data is evaluated to be 32 pct, which is acceptable considering the large error in viscosity measurement of the completely liquid silicate melt.

Solvation consequences of polymer PVP with biological buffers MES, MOPS, and MOPSO in aqueous solutions

International Nuclear Information System (INIS)

Gupta, Bhupender S.; Chen, Bo-Ren; Lee, Ming-Jer

2015-01-01

Highlights: • Densities and viscosities data for aqueous solutions with PVP and/or buffer. • The studied buffers include MES, MOPS, and MOPSO. • DFT was used to estimate the binding energies of the (PVP + buffer) complexes. • The viscosity data were correlated with the Jones–Dole equation. • The investigated buffers behave as Kosmotropies. - Abstract: Densities and viscosities were measured for the aqueous buffer (MES, MOPS, or MOPSO) solutions containing different concentrations of polyvinylpyrrolidone (PVP) (5, 10, 15, 20 and 30) mass% at temperatures from (298.15 to 318.15) K under atmospheric pressure. The DFT calculations were also performed and the binding energies of the possible (PVP + buffer) complexes were obtained. The experimental and computational results reveal the interactions of the PVP with the constituent compounds in the aqueous buffer solutions. Additionally we have explored the solvation behavior of the buffers by measuring the densities and the viscosities data of the aqueous buffer solutions from (0.0 to 1.0) mol · kg"−"1 at temperatures from (298.15 to 318.15) K. The viscosity results were correlated with the Jones–Dole equation. The correlated results confirmed that all the investigated buffers behave as Kosmotropes (structure makers).

Effect of hydrophilic additives on volumetric and viscosity properties of amino acids in aqueous solutions at T = (283.15 to 333.15) K

International Nuclear Information System (INIS)

Sastry, Nandhibatla V.; Valand, Pinakin H.; Macwan, Pradip M.

2012-01-01

Highlights: ► Densities and viscosities of amino acids in aqueous additive solutions at different temperatures. ► Side chain partial molar volumes, V ¯ 2,tr ∘ and transfer volumes ΔV tr ∘ were calculated. ► Temperature effect on volumetric functions and B-coefficients were analyzed. ► Hydrophobic side chains facilitate the solute–solute interactions and hydrophobic hydration. - Abstract: Apparent molar volumes and partial molar volumes at infinite dilution, V ¯ 2 ∘ for amino acids (glycine, L-valine, L-leucine, L-phenylalanine, and L-aspargine) aqueous solutions in sucrose (0.05 to 0.2 (w/w)), urea (0.05), 2,3-butane diol (0.05) and 2-butoxyethanol (0.05) as additives have been calculated from the experimental densities at T = (283.15 to 233.15) K. Limiting partial molar expansibilities, E 2 ∘ , side chain partial molar volumes, V ¯ 2,tr ∘ and transfer volumes (from water to aqueous additive environment), ΔV tr ∘ for both the amino acids and their side chains have also been calculated. Relative viscosities for same systems were also calculated over the same temperature range and were analyzed in terms of Jones–Dole equation to calculate B-coefficients. The analysis of volumetric functions and B-coefficients suggests that the solute–co-solute interactions are more favored at elevated temperatures and in presence of high concentration of sucrose. Otherwise the hydrophobic side chains facilitate the solute–solute interactions and also time induced hydrophobic hydration in the bulk water.

Utilizing the non-bridge oxygen model to predict the glass viscosity

International Nuclear Information System (INIS)

Choi, Kwansik; Sheng, Jiawei; Maeng, Sung Jun; Song, Myung Jae

1998-01-01

Viscosity is the most important process property of waste glass. Viscosity measurement is difficult and costs much. Non-bridging Oxygen (NBO) model which relates glass composition to viscosity had been developed for high level waste at the Savannah River Site (SRS). This research utilized this NBO model to predict the viscosity of KEPRI's 55 glasses. It was found that there was a linear relationship between the measured viscosity and the predicted viscosity. The NBO model could be used to predict glass viscosity in glass formulation development. However the precision of predicted viscosity is out of satisfaction because the composition ranges are very different between the SRS and KEPRI glasses. The modification of NBO calculation, which included modification of alkaline earth elements and TiO 2 , could not strikingly improve the precision of predicted values

Elongational viscosity of narrow molar mass distribution polystyrene

DEFF Research Database (Denmark)

Bach, Anders; Almdal, Kristoffer; Rasmussen, Henrik Koblitz

2003-01-01

Transient and steady elongational viscosity has been measured for two narrow molar mass distribution polystyrene melts of molar masses 200 000 and 390 000 by means of a filament stretching rheometer. Total Hencky strains of about five have been obtained. The transient elongational viscosity rises...... above the linear viscoelastic prediction at intermediate strains, indicating strain hardening. The steady elongational viscosities are monotone decreasing functions of elongation rate. At elongation rates larger than the inverse reptation time, the steady elongational viscosity scales linearly...

Temperature dependence of bulk viscosity in water using acoustic spectroscopy

International Nuclear Information System (INIS)

Holmes, M J; Parker, N G; Povey, M J W

2011-01-01

Despite its fundamental role in the dynamics of compressible fluids, bulk viscosity has received little experimental attention and there remains a paucity of measured data. Acoustic spectroscopy provides a robust and accurate approach to measuring this parameter. Working from the Navier-Stokes model of a compressible fluid one can show that the bulk viscosity makes a significant and measurable contribution to the frequency-squared acoustic attenuation. Here we employ this methodology to determine the bulk viscosity of Millipore water over a temperature range of 7 to 50 0 C. The measured attenuation spectra are consistent with the theoretical predictions, while the bulk viscosity of water is found to be approximately three times larger than its shear counterpart, reinforcing its significance in acoustic propagation. Moreover, our results demonstrate that this technique can be readily and generally applied to fluids to accurately determine their temperature dependent bulk viscosities.

Viscosity measurement in the capillary tube viscometer under unsteady flow

International Nuclear Information System (INIS)

Park, Heung Jun; Yoo, Sang Sin; Suh, Sang Ho

2000-01-01

The objective of the present study is to develop a new device that the viscous characteristics of fluids are determined by applying the unsteady flow concept to the traditional capillary tube viscometer. The capillary tube viscometer consists of a small cylindrical reservoir, capillary tube, a load cell system that measures the mass flow rate, interfaces, and computer. Due to the small size of the reservoir the height of liquid in the reservoir decreases as soon as the liquid in the reservoir drains out through the capillary and the mass flow rate in the capillary decreases as the hydrostatic pressure in the reservoir decreases resulting in a decrease of the shear rate in the capillary tube. The instantaneous shear rate and driving force in the capillary tube are determined by measuring the mass flow rate through the capillary, and the fluid viscosity is determined from the measured flow rate and the driving force

Various methods for determination of liquid viscosity with nuclear track membranes

International Nuclear Information System (INIS)

Guo Shilun

1991-01-01

A systematic study has been performed of the methods for determination of liquid viscosity with nuclear track membranes. Absolute and relative measurements have been suggested, the latter including relative measurements of absolute viscosity and kinematic viscosity. The study shows that the nuclear track membrane is a unique element for determination of liquid viscosity because it is small in volume, accurate in results and easy to manipulate in industries and laboratories

Convergence of a residual based artificial viscosity finite element method

KAUST Repository

Nazarov, Murtazo

2013-02-01

We present a residual based artificial viscosity finite element method to solve conservation laws. The Galerkin approximation is stabilized by only residual based artificial viscosity, without any least-squares, SUPG, or streamline diffusion terms. We prove convergence of the method, applied to a scalar conservation law in two space dimensions, toward an unique entropy solution for implicit time stepping schemes. © 2012 Elsevier B.V. All rights reserved.

A viscosity and density meter with a magnetically suspended rotor

International Nuclear Information System (INIS)

Bano, Mikulas; Strharsky, Igor; Hrmo, Igor

2003-01-01

A device for measuring the viscosity and density of liquids is presented. It is a Couette-type viscometer that uses a submerged rotor to measure the viscosity without errors originating in the contact of the rotor with the sample/air boundary. The inner cylinder is a glass rotor suspended in the liquid, and the outer cylinder is also made of glass. The rotor is stabilized on the axis of the outer cylinder by an electromagnetic force controlled by feedback from the rotor's vertical position. In the lower part of the rotor is an aluminum cylinder located in a magnetic field generated by rotating permanent magnets. The interaction of this rotating magnetic field with eddy currents generated in the aluminum cylinder causes rotation of the rotor. This rotation is optically detected, and viscosity is calculated from the measured angular velocity of rotor. The density of the liquid is calculated from the applied vertical equilibrating force. A computer controls the whole measurement. The device works at constant temperature or while scanning temperature. The sample volume is 1.6 ml, and the accuracy of measurement of both viscosity and density is ∼0.1%. The range of measured densities is (0.7-1.4) g/ml, and viscosity can be measured in the range (3x10 -4 -0.3) Pa s. The shear rate of the viscosity measurement varies in the range (20-300) s-1. The accuracy of the temperature measurement is 0.02 K

Real-time monitoring of viscosity changes triggered by chemical reactions using a high-speed imaging method

Directory of Open Access Journals (Sweden)

Wooseok Jung

2015-09-01

Full Text Available We present a method to monitor in real time peptide self-assembly or polymerization events. The temperature controlled modification of a previously reported splash test setup using high speed imaging enables to observe and measure rheological changes in liquid samples and can, in turn, monitor a peptide self-assembly or polymerization reaction accompanied with specific changes in solution viscosity. A series of 2 mm glass beads were dropped into an Fmoc-L3-OMe (methylated Fluorenylmethyloxycarbonyl-trileucine solution mixed with Alcalase 2.4 L (EC 3.4.21.62 or first dipped in Tetramethylethylenediamine (TEMED, a catalyst for acrylamide polymerization, then dropped into acrylamide. The resulting splashes were observed using a high speed camera. The results demonstrate that the viscosity changes of the peptide sample during the peptide self-assembly or acrylamide polymerization affect the specific shape and evolution of the splashing event. Typically, the increase in viscosity while the reaction occurs decreased the size of the splash and the amount of time for the splash to reach maximum extension from the moment for the beads to impact the sample. The ability to observe rheological changes of sample state presents the opportunity to monitor the real time dynamics of peptide self-assembly or cross-polymerization. Keywords: High-speed imaging, Self-assembly, Viscosity sensor

Vanishing Viscosity Approach to the Compressible Euler Equations for Transonic Nozzle and Spherically Symmetric Flows

Science.gov (United States)

Chen, Gui-Qiang G.; Schrecker, Matthew R. I.

2018-04-01

We are concerned with globally defined entropy solutions to the Euler equations for compressible fluid flows in transonic nozzles with general cross-sectional areas. Such nozzles include the de Laval nozzles and other more general nozzles whose cross-sectional area functions are allowed at the nozzle ends to be either zero (closed ends) or infinity (unbounded ends). To achieve this, in this paper, we develop a vanishing viscosity method to construct globally defined approximate solutions and then establish essential uniform estimates in weighted L p norms for the whole range of physical adiabatic exponents γ\\in (1, ∞) , so that the viscosity approximate solutions satisfy the general L p compensated compactness framework. The viscosity method is designed to incorporate artificial viscosity terms with the natural Dirichlet boundary conditions to ensure the uniform estimates. Then such estimates lead to both the convergence of the approximate solutions and the existence theory of globally defined finite-energy entropy solutions to the Euler equations for transonic flows that may have different end-states in the class of nozzles with general cross-sectional areas for all γ\\in (1, ∞) . The approach and techniques developed here apply to other problems with similar difficulties. In particular, we successfully apply them to construct globally defined spherically symmetric entropy solutions to the Euler equations for all γ\\in (1, ∞).

Determination of Viscosity Versus Pressure by Means of a Clearance Seal

DEFF Research Database (Denmark)

Christiansen, Peter; Schmidt Hansen, Niels; Lund, Martin Thomas Overdahl

2018-01-01

This paper describes the construction and testing of a simple, experimental tool setup that enables determination of the pressure–viscosity relationship for high viscosity oils. Comparing the determined pressure–viscosity relationship with a reference rheometer measuring the viscosity at ambient ...

Effect of various solvents on the viscosity-average molecular weight of poly (vinyl acetate)

International Nuclear Information System (INIS)

Rehman, W.U.; But, M.A.; Chughtai, A.; Jamil, T.; Sattar, A.

2006-01-01

Solution polymerization of Vinyl Acetate was carried out in various solvents (benzene, toluene, ethyl acetate, acetonitrile). Dilute solution viscometry was used to determine the viscosity-average molecular weight of the resulting Poly (Vinyl Acetate) (PV Ac) in each case. The viscosity-average molecular weight (M,J of PVAc was found to increase in the order benzene < toluene < ethyl acetate < acetonitrile, It was concluded that under the same reaction conditions (polymerization time, initiator quantity, solvent/monomer ratio, temperature), acetonitrile served as the best solvent for solution. polymerization of Vinyl Acetate monomer. (author)

Use of Intrinsic Viscosity for evaluation of polymer-solvent affinity

DEFF Research Database (Denmark)

Marani, Debora; Hjelm, Johan; Wandel, Marie

2013-01-01

The objective of the current paper was to define a rheological method for the study of the solvent/binder affinity. The adopted strategy involves the study of the intrinsic viscosity [η] of polymer solutions. [η] was estimated via an extrapolation procedure using the Huggins and Kramer equations....... The intrinsic viscosity and the Mark-Houwink shape parameter were estimated for the three polymers and used as criteria for estimating the polymer/solvent affinity....

Understanding the Viscosity of Liquids used in Infant Dysphagia Management.

Science.gov (United States)

Frazier, Jacqueline; Chestnut, Amanda H; Jackson, Arwen; Barbon, Carly E A; Steele, Catriona M; Pickler, Laura

2016-10-01

When assessing swallowing in infants, it is critical to have confidence that the liquids presented during the swallow study closely replicate the viscosity of liquids in the infant's typical diet. However, we lack research on rheological properties of frequently used infant formulas or breastmilk, and various forms of barium contrast media used in swallow studies. The aim of the current study was to provide objective viscosity measurements for typical infant liquid diet options and barium contrast media. A TA-Instruments AR2000 Advanced Rheometer was used to measure the viscosity of five standard infant formulas, three barium products, and two breastmilk samples. Additionally, this study measured the viscosity of infant formulas and breastmilk when mixed with powdered barium contrast in a 20 % weight-to-volume (w/v) concentration. The study findings determined that standard infant formulas and the two breastmilk samples had low viscosities, at the lower end of the National Dysphagia Diet (NDD) thin liquid range. Two specialty formulas tested had much thicker viscosities, close to the lower boundary of the NDD nectar-thick liquid range. The study showed differences in viscosity between 60 % w/v barium products (Liquid E-Z-Paque(®) and E-Z-Paque(®) powder); the powdered product had a much lower viscosity, despite identical barium concentration. When E-Z-Paque(®) powdered barium was mixed in a 20 % w/v concentration using water, standard infant formulas, or breastmilk, the resulting viscosities were at the lower end of the NDD thin range and only slightly thicker than the non-barium comparator liquids. When E-Z-Paque(®) powdered barium was mixed in a 20 % w/v concentration with the two thicker specialty formulas (Enfamil AR 20 and 24 kcal), unexpected alterations in their original viscosity occurred. These findings highlight the clinical importance of objective measures of viscosity as well as objective data on how infant formulas or breastmilk may change in

Understanding the Viscosity of Liquids used in Infant Dysphagia Management

Science.gov (United States)

Frazier, Jackie; Chestnut, Amanda; Jackson, Arwen; Barbon, Carly E. A.; Steele, Catriona M.; Pickler, Laura

2016-01-01

When assessing swallowing in infants, it is critical to have confidence that the liquids presented during the swallow study closely replicate the viscosity of liquids in the infant's typical diet. However, we lack research on rheological properties of frequently used infant formulas or breastmilk, and various forms of barium contrast media used in swallow studies. The aim of the current study was to provide objective viscosity measurements for typical infant liquid diet options and barium contrast media. A TA-Instruments AR2000 Advanced Rheometer was used to measure the viscosity, five standard infant formulas, three barium products and two breastmilk samples. Additionally, this study measured the viscosity of infant formulas and breastmilk when mixed with powdered barium contrast in a 20% weight-to-volume (w/v) concentration. Study findings determined that standard infant formulas and the two breastmilk samples had low viscosities, at the lower end of the National Dysphagia Diet (NDD) thin liquid range. Two specialty formulas tested had much thicker viscosities, close to the NDD nectar-thick liquid range lower boundary. The study showed differences in viscosity between two 60% w/v barium products (Liquid E-Z-Paque® and E-Z-Paque® powder); the powdered product had a much lower viscosity, despite identical barium concentration. When E-Z-Paque® powdered barium was mixed in a 20% w/v concentration using water, standard infant formulas or breastmilk, the resulting viscosities were at the lower end of the NDD thin range, and only slightly thicker than the non-barium comparator liquids. When E-Z-Paque® powdered barium was mixed in a 20% w/v concentration with the two thicker specialty formulas (Enfamil AR 20kcal and 24 kcal), unexpected alterations in their original viscosity occurred. These findings highlight the clinical importance of objective measures of viscosity as well as objective data on how infant formulas or breastmilk may change in consistency when mixed

Universality of the high-temperature viscosity limit of silicate liquids

DEFF Research Database (Denmark)

Zheng, Qiuju; Mauro, John C.; Ellison, Adam J.

2011-01-01

We investigate the high-temperature limit of liquid viscosity by analyzing measured viscosity curves for 946 silicate liquids and 31 other liquids including metallic, molecular, and ionic systems. Our results show no systematic dependence of the high-temperature viscosity limit on chemical...... composition for the studied liquids. Based on theMauro-Yue-Ellison-Gupta-Allan (MYEGA) model of liquid viscosity, the high-temperature viscosity limit of silicate liquids is 10−2.93 Pa·s. Having established this value, there are only two independent parameters governing the viscosity-temperature relation...

Viscosity overshoot followed by steady state measured in uni-axial elongation of LDPE. Ole Hassager, Henrik Koblitz Rasmussen, Anders Bach and Jens Kromann Nielsen

DEFF Research Database (Denmark)

Rasmussen, Henrik Koblitz; Hassager, Ole; Bach, Anders

2004-01-01

The transient (e.g. start up of) elongational viscosity of three low-density polyethylene (LDPE) melts (BASF Lupolen 1810H, 1840D and 3020D) was measured using a filament stretching rheometer (FSR) capable of measuring at elevated temperatures. The transient uni-axial elongational viscosity showe...

Viscosity calculations of simulated ion-exchange resin waste glasses

International Nuclear Information System (INIS)

Kim, Cheon Woo; Park, Jong Kil; Lee, Kyung Ho; Lee, Myung Chan; Song, Myung Jae; BRUNELOT, Pierre

2000-01-01

An induction cold crucible melter (CCM) located in the NETEC-KEPCO has been used to vitrify simulated ion-exchange resin. During vitrification, the CCM operations were tightly constrained by glass viscosity as an important process parameter. Understanding the role of viscosity and quantifying viscosity is highly required in the determination of optimized feed formulations and in the selection of the processing temperature. Therefore, existing process models of glass viscosity based on a relationship between the glass composition, its structure polymerization, and the temperature were searched and adapted to our borosilicate glass systems. Calculated data using a viscosity model based on calculation of non-bridging oxygen (NBO) were in good agreement with the measured viscosity data of benchmark glasses

Solution dynamics of synthetic and natural polyelectrolytes

Science.gov (United States)

Krause, Wendy E.

Polyelectrolytes are abundant in nature and essential to life, and used extensively in industry. This work discussed two polyelectrolytes: sodium poly(2-acrylamido-2-methylpropanesulfonate) (NaPAMS), synthetic polyelectrolyte, and sodium hyaluronate (NaHA), a glycosaminoglycan. Rheological data of NaPAMS solutions of variable chain length and concentration were reported. A strong dependence of viscosity eta on chain length: eta ˜ M2.4 was found. The comparison of the rheological data with two proposed scaling theories (Dobrynin 1995, Witten 1987) forces the conclusion that neither theory is correct. A possible interpretation of the viscosity data falling between the predictions of the two scaling theories is that some chain rigidity may persist beyond the correlation length. A sample model for the conductivity of semidilute polyelectrolytes with no added salt was presented. The model correctly describes the logarithmic decrease of specific conductance observed for many polyelectrolytes at low concentration (below ca. 10-2M), and is in good agreement with data from NaPAMS solutions. NaHA in phosphate buffered saline behaves as a typical polyelectrolyte in the high-salt limit, as Newtonian viscosities are observed over a wide range of shear rates. There is no evidence of intermolecular hydrogen bonding causing gel formation in NaHA solutions without protein present. The viscosity of 3 mg/mL NaHA was measured in the presence of the selected anti-inflammatory agents. Of the seven additives investigated only (D)-penicillamine significantly altered the rheology of HA. (D)-Penicillamine dramatically reduced the viscosity of HA, probably by disrupting intramolecular hydrogen bonding. The plasma proteins albumin and gamma-globulins bind to HA in solution to form a weak reversible gel. The rheology and osmotic pressure of the simple model for synovial fluid, consisting of 3mg/mL NaHA, 11 mg/mL albumin, and 7 mg/mL gamma-globulins in phosphate buffered saline, were studied

Design of Oil Viscosity Sensor Based on Plastic Optical Fiber

Science.gov (United States)

Yunus, Muhammad; Arifin, A.

2018-03-01

A research of plastic optical fiber based sensors have been studied for measurement of oil viscosity. This sensor was made with straight configuration, U configuration, and gamma configuration have two types, there are optical fiber sensor with cladding and without cladding. Viscosity sensor was made, dipped into an oil sample with a concentration of viscosity percentage about 270 mPa.s - 350 mPa.s. The light from the LED propagated into the optical fiber, then it was received by the photodetector converted to output power. When plastic optical fiber dipped into an oil sample, viscosity of oil affect increase of refractive index on optical fiber resulting in a bigger loss of power so the light intensity will be smaller, consequences the measured output power will be smaller. Sensitivity and resolution viscosity sensor without cladding peel showed the best result rather than viscosity sensor with cladding peel. The best result in the measurement showed in gamma configuration with 3 cm length of cladding peel and the diameter of bending 0,25 cm is the range 103,090 nWatt, sensitivity 1,289 nWatt/mPa.s, and resolution 0,776 mPa.s. This method is effectively and efficiently used as an oil viscosity sensor with high sensitivity and resolution.

Influence of hydroxypropylmethyl cellulose-sodium laurylsulfate interaction on rheological properties of the solution

Directory of Open Access Journals (Sweden)

Šaletić Jelena V.

2004-01-01

Full Text Available Interactions between the polymers and surfactants in solution have widely been investigated because of their scientific and technological importance. These interactions can be utilized to modify the physicochemical properties of system in many food products, pharmaceutical formulations, personal care products, paints, pesticides, etc. Interaction between nonionic polymer - hydroxypropylmethyl cellulose (HPMC and anionic surfactant - sodium laurylsulfate (SDS in solution has been investigated in this paper by rheological measurements. Rheological measurements are performed by rotational viscometer at 20°C and changes of rheological characteristics of HPMC solutions (0.5-1.5% with increasing SDS concentrations (0-4.0% were determined. The results of these investigations showed that viscosity of the solution is dependant on HPMC-SDS interaction. At particular SDS concentration viscosity increases, reach maximum and after that decreases until reach constant value. From the viscosity changes the characteristic concentrations of SDS, critical aggregation concentration (cac and polymer saturation point (psp, were determined. These concentrations are in linear relationships with HPMC concentrations. Rheological properties of the solution are strong influenced by HPMC-SDS interaction and exhibits more or less pronounced pseudoplastic behavior, which changes to Newtonian one after the psp has been reached.

In situ observation of sol-gel transition of agarose aqueous solution by fluorescence measurement.

Science.gov (United States)

Wang, Zheng; Yang, Kun; Li, Haining; Yuan, Chaosheng; Zhu, Xiang; Huang, Haijun; Wang, Yongqiang; Su, Lei; Fang, Yapeng

2018-06-01

Sol-gel transition behavior of agarose aqueous solution was investigated by using rheology and fluorescence measurement. On heating, the storage modulus G' decreased gradually, then deviated abruptly at the temperature of about 65°C, and finally decreased slowly again. For fluorescence measurement, the phase transition point kept almost at the temperature of 65°C, which was consistent with that in rheology measurement. Upon compression, it was indicated that the fluorescence lifetime for the probe in the agarose aqueous solution showed a dramatic change in the vicinity of the phase transition point. T vs. P phase diagram of agarose aqueous solution was constructed, which showed that the melting point was an increasing function of pressure. Based on the phase diagram, the agarose gels were prepared by cooling under atmospheric pressure and the pressure of 300MPa, respectively. From the result of the recovered samples studied by optical rheometry, it was found that agarose gel prepared under high pressure had a higher elasticity and lower viscosity index, compared with that under atmospheric pressure. It could be speculated that such kinds of properties might be attributed to the smaller pore size during gelation under high pressure. Copyright © 2018. Published by Elsevier B.V.

Viscometric study of high-cis polybutadiene in toluene solution

International Nuclear Information System (INIS)

Mwllo, Ivana L.; Coutinho, Fernanda M.B.; Delpech, Marcia C.; Albino, Fernanda F.M.

2006-01-01

Viscometric measurements, in toluene solution at 30 deg C, were performed with high-cis polybutadiene synthesized by neodymium based catalyst. Six different equations were used to calculate intrinsic viscosities and viscosimetric constant values: Huggins, Kraemer, Martin and Schulz-Blaschke by graphic extrapolation, and Solomon-Ciuta, Deb-Chanterjee and again Schulz- Blaschke, through a single point determination. The molecular weight of the polymers was also determined applying Mark-Houwink-Sakurada equation using the values of intrinsic viscosity obtained by the six equations. The values of intrinsic viscosity and viscosity-average molecular weight obtained by the two methods were compared in order to verify the validity of the single point determination for high-cis polybutadiene. (author)

Temperature Dependence Viscosity and Density of Different Biodiesel Blends

Directory of Open Access Journals (Sweden)

Vojtěch Kumbár

2015-01-01

Full Text Available The main goal of this paper is to assess the effect of rapeseed oil methyl ester (RME concentration in diesel fuel on its viscosity and density behaviour. The density and dynamic viscosity were observed at various mixing ratios of RME and diesel fuel. All measurements were performed at constant temperature of 40 °C. Increasing ratio of RME in diesel fuel was reflected in increased density value and dynamic viscosity of the blend. In case of pure RME, pure diesel fuel, and a blend of both (B30, temperature dependence of dynamic viscosity and density was examined. Temperature range in the experiment was −10 °C to 80 °C. Considerable temperature dependence of dynamic viscosity and density was found and demonstrated for all three samples. This finding is in accordance with theoretical assumptions and reference data. Mathematical models were developed and tested. Temperature dependence of dynamic viscosity was modeled using a polynomial 3rd polynomial degree. Correlation coefficients R −0.796, −0.948, and −0.974 between measured and calculated values were found. Temperature dependence of density was modeled using a 2nd polynomial degree. Correlation coefficients R −0.994, −0.979, and −0.976 between measured and calculated values were acquired. The proposed models can be used for flow behaviour prediction of RME, diesel fuel, and their blends.

Containerless Measurements of Density and Viscosity of Fe-Co Alloys

Science.gov (United States)

Lee, Jonghyun; Choufani, Paul; Bradshaw, Richard C.; Hyers, Robert W.; Matson, Douglas M.

2012-01-01

During the past years, extensive collaborative research has been done to understand phase selection in undercooled metals using novel containerless processing techniques such as electrostatic and electromagnetic levitation. Of major interest is controlling a two-step solidification process, double recalescence, in which the metastable phase forms first and then transforms to the stable phase after a certain delay time. The previous research has shown that the delay time is greatly influenced by the internal convection velocity. In the prediction of internal flow, the fidelity of the results depends on the accuracy of the material properties. This research focuses on the measurements of density and viscosity of Fe-Co alloys which will be used for the fluid simulations whose results will support upcoming International Space Station flight experiments.

Kinematic viscosity of liquid Al-Cu alloys

International Nuclear Information System (INIS)

Konstantinova, N Yu; Popel, P S

2008-01-01

Temperature dependences of kinematic viscosity n of liquid Al 100-x -Cu x alloys (x = 0.0, 10.0, 17.1, 25.0, 32.2, 40.0 and 50.0 at.%) were measured. A technique based on registration of the period and the decrement of damping of rotating oscillations of a cylindrical crucible with a melt was used. Viscosity was calculated in low viscous liquids approximation. Measurements were carried out in vacuum in crucibles of BeO with a temperature step of 30 deg. C and isothermal expositions of 10 to 15 minutes during both heating up to 1100-1250 deg. C and subsequent cooling. We have discovered branching of heating and cooling curves v(T) (hysteresis of viscosity) below temperatures depending on the copper content: 950 deg. C at 10 and 17.1 at.% Cu, 1050 deg. C at 25 and 40 at.% Cu, 850 deg. C at 32.2 at.% Cu. For samples with 10 and 17.1 at.% Cu the cooling curve 'returns' to the heating one near 700 deg. C. An abnormally high spreading of results at repeated decrement measurements was fixed at heating of the alloy containing 50 at.% Cu above 1000 deg. C. During subsequent cooling the effect disappeared. Isotherms of kinematic viscosity have been fitted for several temperatures

Long-time stability effects of quadrature and artificial viscosity on nodal discontinuous Galerkin methods for gas dynamics

Science.gov (United States)

Durant, Bradford; Hackl, Jason; Balachandar, Sivaramakrishnan

2017-11-01

Nodal discontinuous Galerkin schemes present an attractive approach to robust high-order solution of the equations of fluid mechanics, but remain accompanied by subtle challenges in their consistent stabilization. The effect of quadrature choices (full mass matrix vs spectral elements), over-integration to manage aliasing errors, and explicit artificial viscosity on the numerical solution of a steady homentropic vortex are assessed over a wide range of resolutions and polynomial orders using quadrilateral elements. In both stagnant and advected vortices in periodic and non-periodic domains the need arises for explicit stabilization beyond the numerical surface fluxes of discontinuous Galerkin spectral elements. Artificial viscosity via the entropy viscosity method is assessed as a stabilizing mechanism. It is shown that the regularity of the artificial viscosity field is essential to its use for long-time stabilization of small-scale features in nodal discontinuous Galerkin solutions of the Euler equations of gas dynamics. Supported by the Department of Energy Predictive Science Academic Alliance Program Contract DE-NA0002378.

Elongational viscosity of monodisperse and bidisperse polystyrene melts

DEFF Research Database (Denmark)

Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole

2006-01-01

The start-up and steady uniaxial elongational viscosity have been measured for two monodisperse polystyrene melts with molecular weights of 52 and 103 kg/mole, and for three bidisperse polystyrene melts. The monodisperse melts show a maximum in the steady elongational viscosity vs. the elongational...

Viscosity of Ga-Li liquid alloys

Science.gov (United States)

Vidyaev, Dmitriy; Boretsky, Evgeny; Verkhorubov, Dmitriy

2018-03-01

The measurement of dynamic viscosity of Ga-Li liquid alloys has been performed using low-frequency vibrational viscometer at five temperatures in the range 313-353 K and four gallium-based dilute alloy compositions containing 0-1.15 at.% Li. It was found that the viscosity of the considered alloys increases with decreasing temperature and increasing lithium concentration in the above ranges. It was shown that dependence of the viscosity of Ga-Li alloys in the investigated temperature range has been described by Arrhenius equation. For this equation the activation energy of viscous flow and pre-exponential factor were calculated. This study helped to determine the conditions of the alkali metals separating process in gallam-exchange systems.

Excess molar volume and viscosity deviation for binary mixtures of γ-butyrolactone with dimethyl sulfoxide

International Nuclear Information System (INIS)

Krakowiak, Joanna; Śmiechowski, Maciej

2017-01-01

Highlights: • Densities and viscosities of DMSO-GBL binary liquid mixtures were measured. • The volumetric parameters and excess quantities were obtained. • Ab initio calculations were performed for single molecules and dimers in the studied mixture. • The interactions in solutions are weaker than in pure solvents. - Abstract: The densities of binary liquid mixtures of dimethyl sulfoxide and γ-butyrolactone at (293.15, 298.15, 303.15 and 313.15) K and viscosity at T = 298.15 K have been measured at atmospheric pressure over the entire range of concentration. From these data the excess molar volumes V E at (293.15, 298.15, 303.15 and 313.15) K and the viscosity deviation, the excess entropy, and the excess Gibbs energy of activation for viscous flow at T = 298.15 K have been determined. These data were mathematically represented by the Redlich-Kister polynomial. Partial and apparent molar volumes have been calculated for better understanding of the interactions in the binary systems. The obtained data indicate the lack of specific interactions between unlike molecules, which seem to be a little weaker as compared to the interactions in pure solvents.

A Study of Nonlinear Variable Viscosity in Finite-Length Tube with Peristalsis

Directory of Open Access Journals (Sweden)

Y. Abd Elmaboud

2014-01-01

Full Text Available Peristaltic motion of an incompressible Newtonian fluid with variable viscosity induced by periodic sinusoidal traveling wave propagating along the walls of a finite-length tube has been investigated. A perturbation method of solution is sought. The viscosity parameter α (α << 1 is chosen as a perturbation parameter and the governing equations are developed up to the first-order in the viscosity parameter (α. The analytical solution has been derived for the radial velocity at the tube wall, the axial pressure gradient across the length of the tube, and the wall shear stress under the assumption of low Reynolds number and long wavelength approximation. The impacts of physical parameters such as the viscosity and the parameter determining the shape of the constriction on the pressure distribution and on the wall shear stress for integral and non-integral number of waves are illustrated. The main conclusion that can be drawn out of this study is that the peaks of pressure fluctuate with time and attain different values with non-integral numbers of peristaltic waves. The considered problem is very applicable in study of biological flow and industrial flow.

Uni-axial Elongational Viscosity of Linear and Branched polymer melts

DEFF Research Database (Denmark)

Hassager, Ole; Nielsen, Jens Kromann; Rasmussen, Henrik Koblitz

2005-01-01

About 40 years ago interest in the measurement of elongational viscosity of polymer melts started to grow. Here we present measurements of transient (and steady) uni-axial elongational viscosity, using the FSR, of the following melts: Four narrow MMD polystyrene (PS) samples with weight......-average molar mass Mw in the range of 50k to 390k. Three different bi-disperse samples, mixed from the narrow MMD PS. Two low-density polyethylene (LDPE) melts (Lupolen 1840D and 3020D). A steady-state viscosity was kept for 1-2.5 Hencky strain units in all measurements.The measurements on the bi-disperse PS...... melts have demonstrated that both the transient and steady elongational viscosity is quite sensitive to polydispersity. Bi-disperse PS resembles the behaviour of mono-disperse melts only at elongational rates larger then the inverse of maximal time constant of the smallest molecule. As observed in Boger...

Viscometric studies of interactions between ionic liquid 1-octyl-3-methyl-imidazolium bromide and polyvinyl pyrrolidone in aqueous solutions

International Nuclear Information System (INIS)

Mehrdad, Abbas; Shekaari, Hemayat; Niknam, Zahra

2014-01-01

Highlights: • Viscosities of PVP in aqueous solution of IL are measured. • The flow activation energies are calculated. • The flow activation energies are correlated in terms of polymer concentration. • Intrinsic viscosity of PVP is decreased by increasing temperature. - Abstract: Ionic liquids are investigated as solvents for polymerization processes, as plasticizers of various kinds of polymers and as components of the polymeric matrixes. In this research, viscosity of polyvinyl pyrrolidone in aqueous solution of ionic liquid, 1-octyl-3-methyl imidazolium bromide are measured at various temperatures. The flow activation energies are calculated and correlated in terms of polymer concentration. From sign of the initial slope of the activation energy versus polymer concentration at zero concentration, it is concluded that thermodynamic quality of ionic liquid aqueous solutions are reduced by increasing temperature. The value of the intrinsic viscosity of polyvinyl pyrrolidone was determined using Huggins equation and thermodynamic parameters of this polymer were calculated on the basis of intrinsic viscosity. Also the effect of ionic liquid, 1-octyl-3-methyl imidazolium bromide on the thermodynamic parameters of dilute aqueous polyvinyl pyrrolidone solutions, such as (polymer + solvent) interaction parameter, theta temperature, the heat of dilution parameter and the entropy of dilution parameter was investigated. Results suggest that the thermodynamic quality of water was increased slightly by the addition of ionic liquid in aqueous solution of polyvinyl pyrrolidone

3D Suspended Polymeric Microfluidics (SPMF3 with Flow Orthogonal to Bending (FOB for Fluid Analysis through Kinematic Viscosity

Directory of Open Access Journals (Sweden)

Mostapha Marzban

2017-10-01

Full Text Available Measuring of fluid properties such as dynamic viscosity and density has tremendous potential for various applications from physical to biological to chemical sensing. However, it is almost impossible to affect only one of these properties, as dynamic viscosity and density are coupled. Hence, this paper proposes kinematic viscosity as a comprehensive parameter which can be used to study the effect of fluid properties applicable to various fluids from Newtonian fluids, such as water, to non-Newtonian fluids, such as blood. This paper also proposes an ideal microplatform, namely polymeric suspended microfluidics (SPMF3, with flow plane orthogonal to the bending plane of the structure, along with tested results of various fluids covering a wide range of engineering applications. Kinematic viscosity, also called momentum diffusivity, considers changes in both fluid intermolecular forces and molecular inertia that define dynamic viscosity and fluid density, respectively. In this study a 3D suspended polymeric microfluidic system (SPMF3 was employed to detect changes in fluid parameters such as dynamic viscosity and density during fluid processes. Using this innovative design along with theoretical and experimental results, it is shown that, in fluids, the variations of fluid density and dynamic viscosity are not easily comprehensible due to their interconnectivity. Since any change in a fluid will affect both density and dynamic viscosity, measuring both of them is necessary to identify the fluid or process status. Finally, changes in fluid properties were analyzed using simulation and experiments. The experimental results with salt-DI water solution and milk with different fat concentrations as a colloidal fluid show that kinematic viscosity is a comprehensive parameter that can identify the fluids in a unique way using the proposed microplatform.

Comparison of quartz tuning forks and AlN-based extensional microresonators for viscosity measurements in oil/fuel mixtures

Science.gov (United States)

Toledo, J.; Manzaneque, T.; Hernando-García, J.; Vazquez, J.; Ababneh, A.; Seidel, H.; Lapuerta, M.; Sánchez-Rojas, J. L.

2013-05-01

In-situ monitoring of the physical properties of liquids is of great interest in the automotive industry. For example, lubricants are subject to dilution with diesel fuel as a consequence of late-injection processes, which are necessary for regenerating diesel particulate filters. This dilution can be determined by tracking the viscosity and the density of the lubricant. Here we report the test of two in-plane movement based resonators to explore their capability to monitor oil dilution with diesel and biodiesel. One of the resonators is the commercially available millimeter-sized quartz tuning fork, working at 32.7 kHz. The second resonator is a state-of-the-art micron-sized AlN-based rectangular plate, actuated in the first extensional mode in the MHz range. Electrical impedance measurements were carried out to characterize the performance of the structures in various liquid media in a wide range of viscosities. These measurements were completed with the development of low-cost electronic circuits to track the resonance frequency and the quality factor automatically, these two parameters allow to obtain the viscosity of various fluids under investigation, as in the case of dilution of lubricant SAE 15W40 and biodiesel.

High pressure changes of the castor oil viscosity by ultrasonic method

International Nuclear Information System (INIS)

Rostocki, A J; Siegoczynski, R M; Kielczynski, P; Szalewski, M

2008-01-01

The pressure change of viscosity of castor oil have been measured by ultrasonic method within the range of pressure up to 0.9 GPa. For the measurement, the authors have applied a new ultrasonic method based on Bleustein-Gulyaev (B-G) waves. For the lower pressures (up to 0.3 GPa) the results have been compared with earlier results obtained by falling body method, whereas for the higher pressure range results were compared with those obtained by the flow type viscometer. The measurements have shown: 1. Exponential rise of viscosity with pressure up to 0.4 GPa according to the Barus formula. 2. Extraordinary increment of viscosity at constant pressure during phase transition. 3. The decomposition of the high pressure phase during the decompression process have shown very large hysteresis of viscosity on pressure. 4. After the decompression process the viscosity lasts higher then a initial value for several hours

In situ droplet surface tension and viscosity measurements in gas metal arc welding

International Nuclear Information System (INIS)

Bachmann, B; Siewert, E; Schein, J

2012-01-01

In this paper, we present an adaptation of a drop oscillation technique that enables in situ measurements of thermophysical properties of an industrial pulsed gas metal arc welding (GMAW) process. Surface tension, viscosity, density and temperature were derived expanding the portfolio of existing methods and previously published measurements of surface tension in pulsed GMAW. Natural oscillations of pure liquid iron droplets are recorded during the material transfer with a high-speed camera. Frame rates up to 30000 fps were utilized to visualize iron droplet oscillations which were in the low kHz range. Image processing algorithms were employed for edge contour extraction of the droplets and to derive parameters such as oscillation frequencies and damping rates along different dimensions of the droplet. Accurate surface tension measurements were achieved incorporating the effect of temperature on density. These are compared with a second method that has been developed to accurately determine the mass of droplets produced during the GMAW process which enables precise surface tension measurements with accuracies up to 1% and permits the study of thermophysical properties also for metals whose density highly depends on temperature. Thermophysical properties of pure liquid iron droplets formed by a wire with 1.2 mm diameter were investigated in a pulsed GMAW process with a base current of 100 A and a pulse current of 600 A. Surface tension and viscosity of a sample droplet were 1.83 ± 0.02 N m -1 and 2.9 ± 0.3 mPa s, respectively. The corresponding droplet temperature and density are 2040 ± 50 K and 6830 ± 50 kg m -3 , respectively. (paper)

Thermophysical property characterization of aqueous amino acid salt solution containing serine

International Nuclear Information System (INIS)

Navarro, Shanille S.; Leron, Rhoda B.; Soriano, Allan N.; Li, Meng-Hui

2014-01-01

Highlights: • Thermophysical properties of aqueous potassium and sodium salt solutions of serine were studied. • Density, viscosity, refractive index and electrolytic conductivity of the solution were measured. • The concentrations of amino acid salt ranges from x 1 = 0.009 to 0.07. • The temperature range studied was (298.15 to 343.15) K. • The measured data were represented satisfactorily by using the applied correlations. - Abstract: Thermophysical property characterization of aqueous potassium and sodium salt solutions containing serine was conducted in this study; specifically the system’s density, refractive index, electrical conductivity, and viscosity. Measurements were obtained over a temperature range of (298.15 to 343.15) K and at normal atmospheric pressure. Composition range from x 1 = 0.009 to 0.07 for aqueous potassium and sodium salt solutions containing serine was used. The sensitivity of the system’s thermophysical properties on temperature and composition variation were discussed and correlated based on the equations proposed for room temperature ionic liquids. The density, viscosity, and refractive index measurements of the aqueous systems were found to decrease as the temperature increases at fixed concentration and the values increase as the salt concentration increases (water composition decreases) at fixed temperature. Whereas, a different trend was observed for the electrical conductivity data; at fixed concentration, the conductivity values increase as the temperature increases and at fixed temperature, its value generally increases as the salt concentration increases but only to a certain level (specific concentration) wherein the conductivity of the solution starts to decrease when the concentration of the salt is further increased. Calculation results show that the applied models were satisfactory in representing the measured properties in the aqueous amino acid salt solution containing serine

A symmetrizable extension of polyconvex thermoelasticity and applications to zero-viscosity limits and weak-strong uniqueness

KAUST Repository

Christoforou, Cleopatra

2018-03-21

We embed the equations of polyconvex thermoviscoelasticity into an augmented, symmetrizable, hyperbolic system and derive a relative entropy identity in the extended variables. Following the relative entropy formulation, we prove the convergence from thermoviscoelasticity with Newtonian viscosity and Fourier heat conduction to smooth solutions of the system of adiabatic thermoelasticity as both parameters tend to zero. Also, convergence from thermoviscoelasticity to smooth solutions of thermoelasticity in the zero-viscosity limit. Finally, we establish a weak-strong uniqueness result for the equations of adiabatic thermoelasticity in the class of entropy weak solutions.

Effects of SOC-dependent electrolyte viscosity on performance of vanadium redox flow batteries

International Nuclear Information System (INIS)

Xu, Q.; Zhao, T.S.; Zhang, C.

2014-01-01

Highlights: • The correlations of electrolyte viscosity and SOC are obtained. • Effect of SOC-dependent electrolyte viscosity is considered in this model. • This model enables a more realistic simulation of variable distributions. • It provides accurate estimations of pumping work and system efficiency. - Abstract: The viscosity of the electrolyte in vanadium redox flow batteries (VRFBs) varies during charge and discharge as the concentrations of acid and vanadium ions in the electrolyte continuously change with the state of charge (SOC). In previous VRFB models, however, the electrolyte has been treated as a constant-viscosity solution. In this work, a mass-transport and electrochemical model taking account of the effect of SOC-dependent electrolyte viscosity is developed. The comparison between the present model and the model with the constant-viscosity simplification indicates that the consideration of the SOC-dependent electrolyte viscosity enables (i) a more realistic simulation of the distributions of overpotential and current density in the electrodes, and (ii) more accurate estimations of pumping work and the system efficiency of VRFBs

Viscosity of glasses containing simulated Savannah River Plant waste

International Nuclear Information System (INIS)

Plodinec, M.J.

1978-08-01

The viscosity of glass melts containing four simulated sludge types and two frit candidates (Frits 18 and 21) was measured over the temperature range 750 to 1200 0 C. The viscosity of melts made with either frit was reduced by the addition of high iron sludge, unchanged by average sludge, and increased by composite and high aluminum sludge. High aluminium sludge greatly increased the viscosity. Frit 21 (containing 4 wt % Li 2 O substituted for 4 wt % Na 2 O in Frit 18) was clearly better than Frit 18 in terms of its low viscosity. However, further reductions in viscosity are desirable, especially for glasses containing high aluminum sludge. Changing any frit component by 1 wt % did not significantly affect the viscosity of the glasses. Therefore, variability of 1 wt % in any frit component can be tolerated

A comparative study of high-viscosity cement percutaneous vertebroplasty vs. low-viscosity cement percutaneous kyphoplasty for treatment of osteoporotic vertebral compression fractures.

Science.gov (United States)

Sun, Kai; Liu, Yang; Peng, Hao; Tan, Jun-Feng; Zhang, Mi; Zheng, Xian-Nian; Chen, Fang-Zhou; Li, Ming-Hui

2016-06-01

The clinical effects of two different methods-high-viscosity cement percutaneous vertebroplasty (PVP) and low-viscosity cement percutaneous kyphoplasty (PKP) in the treatment of osteoporotic vertebral compression fractures (OVCFs) were investigated. From June 2010 to August 2013, 98 cases of OVCFs were included in our study. Forty-six patients underwent high-viscosity PVP and 52 patients underwent low-viscosity PKP. The occurrence of cement leakage was observed. Pain relief and functional activity were evaluated using the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI), respectively. Restoration of the vertebral body height and angle of kyphosis were assessed by comparing preoperative and postoperative measurements of the anterior heights, middle heights and the kyphotic angle of the fractured vertebra. Nine out of the 54 vertebra bodies and 11 out of the 60 vertebra bodies were observed to have cement leakage in the high-viscosity PVP and low-viscosity PKP groups, respectively. The rate of cement leakage, correction of anterior vertebral height and kyphotic angles showed no significant differences between the two groups (P>0.05). Low-viscosity PKP had significant advantage in terms of the restoration of middle vertebral height as compared with the high-viscosity PVP (Pviscosity PVP and low-viscosity PKP have similar clinical effects in terms of the rate of cement leakage, restoration of the anterior vertebral body height, changes of kyphotic angles, functional activity, and pain relief. Low-viscosity PKP is better than high-viscosity PVP in restoring the height of the middle vertebra.

Viscosity of aqueous and cyanate ester suspensions containing alumina nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Lawler, Katherine [Iowa State Univ., Ames, IA (United States)

2009-01-01

The viscosities of both aqueous and cyanate ester monomer (BECy) based suspensions of alumina nanoparticle were studied. The applications for these suspensions are different: aqueous suspensions of alumina nanoparticles are used in the production of technical ceramics made by slip casting or tape casting, and the BECy based suspensions are being developed for use in an injection-type composite repair resin. In the case of aqueous suspensions, it is advantageous to achieve a high solids content with low viscosity in order to produce a high quality product. The addition of a dispersant is useful so that higher solids content suspensions can be used with lower viscosities. For BECy suspensions, the addition of nanoparticles to the BECy resin is expected to enhance the mechanical properties of the cured composite. The addition of saccharides to aqueous suspensions leads to viscosity reduction. Through DSC measurements it was found that the saccharide molecules formed a solution with water and this resulted in lowering the melting temperature of the free water according to classic freezing point depression. Saccharides also lowered the melting temperature of the bound water, but this followed a different rule. The shear thinning and melting behaviors of the suspensions were used to develop a model based on fractal-type agglomeration. It is believed that the structure of the particle flocs in these suspensions changes with the addition of saccharides which leads to the resultant viscosity decrease. The viscosity of the BECy suspensions increased with solids content, and the viscosity increase was greater than predicted by the classical Einstein equation for dilute suspensions. Instead, the Mooney equation fits the viscosity behavior well from 0-20 vol% solids. The viscosity reduction achieved at high particle loadings by the addition of benzoic acid was also investigated by NMR. It appears that the benzoic acid interacts with the surface of the alumina particle which may

[Sputum viscosity and pulmonary function measurements during a one-week parenteral treatment with a standardized oxidation product of oil of turpentine and terpin hydrate].

Science.gov (United States)

Löllgen-Horres, I; Löllgen, H

1976-01-01

In 23 patients with chronic obstructive lung diseases, viscosity, airway resistance, arterial blood gases and acid-base balance, and sputum aspect were measured before and after one-week treatment with Ozothin, a substance from oxidation products of ol. terebinth. and terpinum hydratum. Within this time, viscosity of the sputum was reduced, airway resistance decreased, and arterial oxygen pressure slightly increased, whereas arterial carbon dioxide tension obvious change of sputum aspect could be observed. Correlation calculations revealed no significant relations between viscosity and the above cited lung function values. The results indicate that administration of Ozothin may liquefy viscous secretion and reduce sputum viscosity.

Volumetric and viscometric studies of some drugs in aqueous solutions at different temperatures

International Nuclear Information System (INIS)

Dhondge, Sudhakar S.; Zodape, Sangesh P.; Parwate, Dilip V.

2012-01-01

Highlights: ► Study of aqueous solutions of biologically important compounds has been reported. ► MH is used for treating type II diabetes, RH is in treatment of peptic ulcer and TH is used to treat severe pain. ► All the compounds act as structure makers by volumetric studies. ► MH and RH act as weak structure breakers and TH acts as a weak structure maker by viscometric studies. - Abstract: Density and viscosity measurements are reported for aqueous solutions of the drugs like Metformin hydrochloride (MH), Ranitidine hydrochloride (RH) and Tramadol hydrochloride (TH) at different temperatures T = (288.15, 298.15, and 308.15) K within the concentration range (0 to 0.15) mol · kg −1 . The density and viscosity data are used to obtain apparent molar volume of solute (φ V ) and relative viscosity (η r ) of aqueous solutions at different temperatures. The limiting apparent molar volume of solute (φ V 0 ), limiting apparent molar expansivity (φ E 0 ), thermal expansion coefficient (α ∗ ), hydration number (n h ), Jones–Dole equation viscosity A and B coefficients, experimental slope (S V ) at different temperatures, and temperature coefficient of Bi.e.(dB/dT) at T = 298.15 K were also obtained. The results obtained have been interpreted in terms of solute–solvent and solute–solute interactions and structure making/breaking ability of solute in the aqueous solution.

Viscosity properties of sodium borophosphate glasses

International Nuclear Information System (INIS)

Gaylord, S.; Tincher, B.; Petit, L.; Richardson, K.

2009-01-01

The viscosity behavior of (1 - x)NaPO 3 -xNa 2 B 4 O 7 glasses (x = 0.05-0.20) have been measured as a function of temperature using beam-bending and parallel-plate viscometry. The viscosity was found to shift to higher temperatures with increasing sodium borate content. The kinetic fragility parameter, m, estimated from the viscosity curve, decreases from 52 to 33 when x increases from 0.05 to 0.20 indicating that the glass network transforms from fragile to strong with the addition of Na 2 B 4 O 7 . The decrease in fragility with increasing x is due to the progressive depolymerization of the phosphate network by the preferred four-coordinated boron atoms present in the low alkali borate glasses. As confirmed by Raman spectroscopy increasing alkali borate leads to enhanced B-O-P linkages realized with the accompanying transition from solely four-coordinated boron (in BO 4 units) to mixed BO 4 /BO 3 structures. The glass viscosity characteristics of the investigated glasses were compared to those of P-SF67 and N-FK5 commercial glasses from SCHOTT. We showed that the dependence of the viscosity of P-SF67 was similar to the investigated glasses due to similar phosphate network organization confirmed by Raman spectroscopy, whereas N-FK5 exhibited a very different viscosity curve and fragility parameter due to its highly coordinated silicate network

Giant Viscosity Enhancement in a Spin-Polarized Fermi Liquid

International Nuclear Information System (INIS)

Akimoto, H.; Xia, J. S.; Adams, E. D.; Sullivan, N. S.; Candela, D.; Mullin, W. J.

2007-01-01

The viscosity is measured for a Fermi liquid, a dilute 3 He- 4 He mixture, under extremely high magnetic field/temperature conditions (B≤14.8 T, T≥1.5 mK). The spin-splitting energy μB is substantially greater than the Fermi energy k B T F ; as a consequence the polarization tends to unity and s-wave quasiparticle scattering is suppressed for T F . Using a novel composite vibrating-wire viscometer an enhancement of the viscosity is observed by a factor of more than 500 over its low-field value. Good agreement is found between the measured viscosity and theoretical predictions based upon a t-matrix formalism

A model for the viscosity of dilute smectite gels

International Nuclear Information System (INIS)

Liu, Di; Liu, Longcheng

2010-01-01

Document available in extended abstract form only. A simple yet accurate model describing the viscosity of dilute suspensions of sodium montmorillonite in low ionic strength waters is presented. Taking the clay particle and the surrounding clouds of ions as whole as an uncharged but soft particle, the Huggins' equation is extended in the model to account for both the primary and the secondary electro-viscous effects, by use of the notion of an effective volume fraction. In the model, however, we do not represent the clay particle as a sphere surrounded by immobile water layer with thickness of a Debye length, as did by Adachi et al. (1998) who used the co-volume fraction to approximate the effective volume fraction. We visualize the effective geometry of the particle and the associated ionic atmosphere as an ellipsoid. This representation is more practical and more plausible, because in the limit of large ionic strength, the electrolyte ions have been screened to a significant extent so that the charged particle behaves just like an uncharged one. As a result, the application of the Simha's equation of intrinsic viscosity for ellipsoidal particle following with random Brownian motion enables us to obtain an analytical expression for the primary electro-viscous effect. More importantly, the available models for hard plate-like particles can be used to aid in the quantification of the secondary electro-viscous effect. The development of the model is based firmly on precise measurements of the viscosity of sufficiently dilute suspensions of sodium montmorillonite in low concentration NaCl solutions (at room temperature) using Ostwald capillary viscometers. The obtained data clearly demonstrate the primary and the secondary electro-viscous effects. That is, with an decrease of ionic strength, the intrinsic viscosity which is the intercept of the extrapolation of the plot at zero volume fraction will increase, and the slope of the linear part which appears in

Shallow water equations: viscous solutions and inviscid limit

Science.gov (United States)

Chen, Gui-Qiang; Perepelitsa, Mikhail

2012-12-01

We establish the inviscid limit of the viscous shallow water equations to the Saint-Venant system. For the viscous equations, the viscosity terms are more degenerate when the shallow water is close to the bottom, in comparison with the classical Navier-Stokes equations for barotropic gases; thus, the analysis in our earlier work for the classical Navier-Stokes equations does not apply directly, which require new estimates to deal with the additional degeneracy. We first introduce a notion of entropy solutions to the viscous shallow water equations and develop an approach to establish the global existence of such solutions and their uniform energy-type estimates with respect to the viscosity coefficient. These uniform estimates yield the existence of measure-valued solutions to the Saint-Venant system generated by the viscous solutions. Based on the uniform energy-type estimates and the features of the Saint-Venant system, we further establish that the entropy dissipation measures of the viscous solutions for weak entropy-entropy flux pairs, generated by compactly supported C 2 test-functions, are confined in a compact set in H -1, which yields that the measure-valued solutions are confined by the Tartar-Murat commutator relation. Then, the reduction theorem established in Chen and Perepelitsa [5] for the measure-valued solutions with unbounded support leads to the convergence of the viscous solutions to a finite-energy entropy solution of the Saint-Venant system with finite-energy initial data, which is relative with respect to the different end-states of the bottom topography of the shallow water at infinity. The analysis also applies to the inviscid limit problem for the Saint-Venant system in the presence of friction.

Magnetisation processes and magnetic viscosity of mechanically alloyed SmCo5

International Nuclear Information System (INIS)

Ding, J.; Smith, P.A.I.; McCormick, P.G.; Street, R.

1996-01-01

Mechanically alloyed SmCo 5 materials with coercivities in the range of 50-75 kOe were studied in this work. Irreversible magnetisation processes were investigated by measuring remanences after initial magnetisation and after demagnetisation. A large deviation of the demagnetisation remanence from the Wohlfarth relationship indicated that interactions between grains play an important role in the irreversible magnetisation process. Viscosity tests showed nearly linear relationship between the magnetic field and the viscosity parameter for the initial magnetisation, while the viscosity was not strongly dependent on the field for the demagnetisation. High values of the viscosity parameter, Λ, between 120 to 220 Oe were measured at fields near coercivity. (orig.)

Nonlinear second order evolution inclusions with noncoercive viscosity term

Science.gov (United States)

Papageorgiou, Nikolaos S.; Rădulescu, Vicenţiu D.; Repovš, Dušan D.

2018-04-01

In this paper we deal with a second order nonlinear evolution inclusion, with a nonmonotone, noncoercive viscosity term. Using a parabolic regularization (approximation) of the problem and a priori bounds that permit passing to the limit, we prove that the problem has a solution.

Density, viscosity, and saturated vapor pressure of ethyl trifluoroacetate

International Nuclear Information System (INIS)

Huang, Zhixian; Jiang, Haiming; Li, Ling; Wang, Hongxing; Qiu, Ting

2015-01-01

Highlights: • Density of ethyl trifluoroacetate was measured and its thermal expansion coefficient was determined. • Viscosity of ethyl trifluoroacetate was measured and fitted to the Andrade equation. • Saturated vapor pressure of ethyl trifluoroacetate was reported. • The Clausius–Clapeyron equation was used to calculate the molar evaporation enthalpy of ethyl trifluoroacetate. - Abstract: The properties of ethyl trifluoroacetate (CF 3 COOCH 2 CH 3 ) were measured as a function of temperature: density (278.08 to 322.50) K, viscosity (293.45 to 334.32) K, saturated vapor pressure (293.35 to 335.65) K. The density data were fitted to a quadratic polynomial equation, and the viscosity data were regressed to the Andrade equation. The correlation coefficient (R 2 ) of equations for density and viscosity are 0.9997 and 0.9999, respectively. The correlation between saturated vapor pressures and temperatures was achieved with a maximum absolute relative deviation of 0.142%. In addition, the molar evaporation enthalpy in the range of T = (293.35 to 335.65) K was estimated by the Clausius–Clapeyron equation

Anomalous intrinsic viscosity of octadecylamine-functionalised carbon nanotubes in suspension.

Science.gov (United States)

Donovan, K J; Scott, K

2013-06-28

Single walled carbon nanotubes, SWCNTs, are used as a model cylinder of nanoscopic dimensions for testing rheological theories of how addition of cylindrical particles affects the viscosity of a suspension of such particles. Using the rate of growth of the accompanying induced linear dichroism following application of an applied electric field, the dynamics of carbon nanotube alignment is studied in suspensions of octadecylamine functionalised single walled carbon nanotubes, ODA-SWCNTs, in 1,2 dichloroethane. From such measurements the viscosity of the suspension is measured as the concentration of the suspension is varied. While working within the dilute limit the viscosity is found to increase linearly with concentration and the intrinsic viscosity of the suspension is found to be 8000. This anomalously high intrinsic viscosity is compared with the predictions of various models for a rigid cylinder and found to be incompatible with any of the current models. Some suggestions are made as to the way this ODA-SWCNT result may be eventually accommodated within other models.

Experimental determination of gamma radiation effect from cobalt 60 on the viscosity of SSBR-B polymer

International Nuclear Information System (INIS)

Santos, L.G. dos; Silva Filho, E.

1989-01-01

Samples of the polymer known as SSBR-B (Solution Styrenne Butadiene Rubber-Blockade) were irradiated with gamma rays from a 60 Co source. Viscosity analysis performed by using the method of Ostwald Showed that the viscosity remains about constant for doses in the range of zero to 11560 Gray (Gy). For doses greater than 11560 Gy the viscosity increases. This result characterizes an irradiation induced hardening of the polymer. (author) [pt

Influence of calcium chelators on concentrated micellar casein solutions : from micellar structure to viscosity and heat stability

NARCIS (Netherlands)

Kort, de E.J.P.

2012-01-01

In practice it is challenging to prepare a concentrated medical product with high heat stability
and low viscosity. Calcium chelators are often added to dairy products to improve heat stability,
but this may increase viscosity through interactions with the casein proteins. The aim of

Nonlinear Eddy Viscosity Models applied to Wind Turbine Wakes

DEFF Research Database (Denmark)

Laan, van der, Paul Maarten; Sørensen, Niels N.; Réthoré, Pierre-Elouan

2013-01-01

The linear k−ε eddy viscosity model and modified versions of two existing nonlinear eddy viscosity models are applied to single wind turbine wake simulations using a Reynolds Averaged Navier-Stokes code. Results are compared with field wake measurements. The nonlinear models give better results...

Thermal ignition in a reactive variable viscosity Poiseuille flow ...

African Journals Online (AJOL)

In this paper, we investigate the thermal ignition in a strongly exothermic reaction of a variable viscosity combustible material flowing through a channel with isothermal walls under Arrhenius kinetics, neglecting the consumption of the material. Analytical solutions are constructed for the governing nonlinear boundary-value ...

Experimental study on viscosity of spinel-type manganese ferrite nanofluid in attendance of magnetic field

Energy Technology Data Exchange (ETDEWEB)

Amani, Mohammad, E-mail: m_amani@sbu.ac.ir [Mechanical and Energy Engineering Department, Shahid Beheshti University, Tehran (Iran, Islamic Republic of); Amani, Pouria, E-mail: pouria.amani@ut.ac.ir [Department of Chemical Engineering, Faculty of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Kasaeian, Alibakhsh, E-mail: akasa@ut.ac.ir [Department of Renewable Energies, Faculty of New Science & Technologies, University of Tehran, Tehran (Iran, Islamic Republic of); Mahian, Omid, E-mail: omid.mahian@mshdiau.ac.ir [Young Researchers and Elite Club, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Kasaeian, Fazel, E-mail: f.kasa92@student.sharif.edu [Faculty of Material Science and Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Wongwises, Somchai, E-mail: somchai.won@kmutt.ac.th [Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab (FUTURE), Department of Mechanical Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi (KMUTT), Bangmod, Bangkok (Thailand)

2017-04-15

In this paper, an experimental evaluation on the viscosity of water-based manganese ferrite nanofluid with and without magnetic field with 100, 200, 300, and 400 G intensities has been conducted. The Brookfield DV-I PRIME viscometer is implemented to measure the MnFe{sub 2}O{sub 4}/water nanofluid viscosity and to evaluate the influence of different volume concentrations (from 0.25% to 3%) and various temperatures (from 20 to 60 °C) on the viscosity. According to the measurements, viscosity incrementally increases with the augmentation of nanoparticles concentration while it remarkably decreases at higher temperatures under absence and attendance of magnetic field. The maximum viscosity ratio of 1.14 is achieved at 3 vol% of nanoparticles and 20 °C under no magnetic field, whereas it increments to maximum viscosity ratio of 1.75 at 3 vol% of nanoparticles and 40 °C under 400 G magnetic field. Furthermore, new correlation is proposed for determination of viscosity of MnFe{sub 2}O{sub 4}/water nanofluids in terms of magnetic field intensity, volume concentration and temperature. - Highlights: • Viscosity of spinel-type manganese ferrite nanofluids is measured. • Effect of a constant magnetic field on the viscosity is investigated. • A novel correlation is proposed for estimation of the measured viscosity.

Experimental study on viscosity of spinel-type manganese ferrite nanofluid in attendance of magnetic field

International Nuclear Information System (INIS)

Amani, Mohammad; Amani, Pouria; Kasaeian, Alibakhsh; Mahian, Omid; Kasaeian, Fazel; Wongwises, Somchai

2017-01-01

In this paper, an experimental evaluation on the viscosity of water-based manganese ferrite nanofluid with and without magnetic field with 100, 200, 300, and 400 G intensities has been conducted. The Brookfield DV-I PRIME viscometer is implemented to measure the MnFe 2 O 4 /water nanofluid viscosity and to evaluate the influence of different volume concentrations (from 0.25% to 3%) and various temperatures (from 20 to 60 °C) on the viscosity. According to the measurements, viscosity incrementally increases with the augmentation of nanoparticles concentration while it remarkably decreases at higher temperatures under absence and attendance of magnetic field. The maximum viscosity ratio of 1.14 is achieved at 3 vol% of nanoparticles and 20 °C under no magnetic field, whereas it increments to maximum viscosity ratio of 1.75 at 3 vol% of nanoparticles and 40 °C under 400 G magnetic field. Furthermore, new correlation is proposed for determination of viscosity of MnFe 2 O 4 /water nanofluids in terms of magnetic field intensity, volume concentration and temperature. - Highlights: • Viscosity of spinel-type manganese ferrite nanofluids is measured. • Effect of a constant magnetic field on the viscosity is investigated. • A novel correlation is proposed for estimation of the measured viscosity.

The Flow of a Variable Viscosity Fluid down an Inclined Plane with a Free Surface

Directory of Open Access Journals (Sweden)

M. S. Tshehla

2013-01-01

Full Text Available The effect of a temperature dependent variable viscosity fluid flow down an inclined plane with a free surface is investigated. The fluid film is thin, so that lubrication approximation may be applied. Convective heating effects are included, and the fluid viscosity decreases exponentially with temperature. In general, the flow equations resulting from the variable viscosity model must be solved numerically. However, when the viscosity variation is small, then an asymptotic approximation is possible. The full solutions for the temperature and velocity profiles are derived using the Runge-Kutta numerical method. The flow controlling parameters such as the nondimensional viscosity variation parameter, the Biot and the Brinkman numbers, are found to have a profound effect on the resulting flow profiles.

Searching for perfect fluids: quantum viscosity in a universal Fermi gas

International Nuclear Information System (INIS)

Cao, C; Elliott, E; Wu, H; Thomas, J E

2011-01-01

We measure the shear viscosity in a two-component Fermi gas of atoms, tuned to a broad s-wave collisional (Feshbach) resonance. At resonance, the atoms strongly interact and exhibit universal behavior, where the equilibrium thermodynamic properties and transport coefficients are universal functions of density n and temperature T. We present a new calibration of the temperature as a function of global energy, which is directly measured from the cloud profiles. Using the calibration, the trap-averaged shear viscosity in units of ℎn is determined as a function of the reduced temperature at the trap center, from nearly the ground state to the unitary two-body regime. Low-temperature data are obtained from the damping rate of the radial breathing mode, whereas high-temperature data are obtained from hydrodynamic expansion measurements. We also show that the best fit to the high-temperature expansion data is obtained for a vanishing bulk viscosity. The measured trap-averaged entropy per particle and shear viscosity are used to estimate the ratio of shear viscosity to entropy density, which is compared with that conjectured for a perfect fluid.

Viscosity, surface tension, density and contact angle of selected PbI2, PbCl2 and methylammonium lead halide perovskite solutions used in perovskite solar cells

Directory of Open Access Journals (Sweden)

Mohammad-Reza Ahmadian-Yazdi

2018-02-01

Full Text Available Perovskite solar cells (PSCs are currently under vigorous research and development, owing to their compelling power conversion efficiencies. PSCs are solution-processed and, therefore, are fabricated using casting and printing methods, such as spin, spray and blade coating. The coating characteristics significantly depend on the physical and rheological properties of the solutions. Thus, due to the scarcity of such properties, in this work, we report the surface tension, viscosity, density, and contact angle of selected methylammonium lead halide perovskite solutions, in order to gain insight into the behavior of the perovskite solutions and the range of such physical properties. The contact angles were measured on PEDOT:PSS and compact TiO2 (c-TiO2 substrates, commonly used as the underneath layers of the perovskite film. In total, 12 solutions of CH3NH3PbI3 and CH3NH3PbI3-xClx dissolved in common solvents, as well as solutions of PbI2, PbCl2, and CH3NH3I were tested. Among the results, it is shown that the tested perovskite solutions are Newtonian, the apparent contact angles on the mesoporous TiO2 (m-TiO2 are close to zero, on the PEDOT:PSS are around 10°, and on the c-TiO2 are around 30°. Also, contact angle hysteresis is observed in the case of the c-TiO2 substrates. Representative impact dynamics and spreading of perovskite solution droplets are also studied, to demonstrate the importance of the solution properties and process parameters on the coating process.

Viscosity, surface tension, density and contact angle of selected PbI2, PbCl2 and methylammonium lead halide perovskite solutions used in perovskite solar cells

Science.gov (United States)

Ahmadian-Yazdi, Mohammad-Reza; Rahimzadeh, Amin; Chouqi, Zineb; Miao, Yihe; Eslamian, Morteza

2018-02-01

Perovskite solar cells (PSCs) are currently under vigorous research and development, owing to their compelling power conversion efficiencies. PSCs are solution-processed and, therefore, are fabricated using casting and printing methods, such as spin, spray and blade coating. The coating characteristics significantly depend on the physical and rheological properties of the solutions. Thus, due to the scarcity of such properties, in this work, we report the surface tension, viscosity, density, and contact angle of selected methylammonium lead halide perovskite solutions, in order to gain insight into the behavior of the perovskite solutions and the range of such physical properties. The contact angles were measured on PEDOT:PSS and compact TiO2 (c-TiO2) substrates, commonly used as the underneath layers of the perovskite film. In total, 12 solutions of CH3NH3PbI3 and CH3NH3PbI3-xClx dissolved in common solvents, as well as solutions of PbI2, PbCl2, and CH3NH3I were tested. Among the results, it is shown that the tested perovskite solutions are Newtonian, the apparent contact angles on the mesoporous TiO2 (m-TiO2) are close to zero, on the PEDOT:PSS are around 10°, and on the c-TiO2 are around 30°. Also, contact angle hysteresis is observed in the case of the c-TiO2 substrates. Representative impact dynamics and spreading of perovskite solution droplets are also studied, to demonstrate the importance of the solution properties and process parameters on the coating process.

Dependence of Helium II viscosity properties on oscillation frequency

International Nuclear Information System (INIS)

Nadirashvili, Z.S.; Tsakadze, J.S.

1979-01-01

The causes of a discrepancy in the results of measurements of He II viscosity below Tapprox. =1.6 K obtained with different measurement methods are investigated. It is shown that to obtain correct results in oscillation experiments, the condition delta>>lambda/sub ph/ should obtain, where delta is the depth of viscous wave penetration and lambda/sub ph/ is the phonon free path length. Results of viscosity measurements at different ratios delta/lambda/sub ph/ (by a wire viscometer) are presented. It is shown that for the condition delta>>lambda/sub ph/, the results obtained are in good agreement with the results of Andronikashvili (in which delta/lambda/sub ph/>100). If the mentioned relation is not satisfied, then as the value of the ratio delta/lambda/sub ph/ is decreased, the value measured for the viscosity is increasingly lower than the results of Andronikashvili

Finding viscosity of liquids from Brownian motion at students' laboratory

International Nuclear Information System (INIS)

Greczylo, Tomasz; Debowska, Ewa

2005-01-01

Brownian motion appears to be a good subject for investigation at advanced students' laboratory [1]. The paper presents such an investigation carried out in Physics Laboratory II at the Institute of Experimental Physics of Wroclaw University. The experiment has been designed to find viscosity of liquids from Brownian motion phenomenon. Authors use modern technology that helps to proceed with measurements and makes the procedure less time and effort consuming. Discussion of the process of setting up the experiment and the results obtained for three different solutions of glycerin in water are presented. Advantages and disadvantages of the apparatus are pointed out along with descriptions of possible future uses

Dynamic rheology behavior of electron beam-irradiated cellulose pulp/NMMO solution

International Nuclear Information System (INIS)

Zhou Ruimin; Deng Bangjun; Hao Xufeng; Zhou Fei; Wu Xinfeng; Chen Yongkang

2008-01-01

The rheological behavior of irradiated cellulose pulp solution by electron beam was investigated. Storage modulus G', loss modulus G'', the dependence of complex viscosity η* and frequency ω of cellulose solutions were measured by DSR-200 Rheometer (Rheometrics co., USA). The molecular weight of irradiated cellulose was measured via the intrinsic viscosity measurement using an Ubbelohde capillary viscometer. The crystalline structure was studied by FTIR Spectroscopy. The results congruously showed that the molecular weight of pulp cellulose decrease and the molecular weight distribution of cellulose become narrow with increase in the irradiation dose. Moreover, the crystalline structure of the cellulose was destroyed, the force of the snarl between the cellulose molecules weakens and the accessibility of pulp spinning is improved. The study supplies some useful data for spinnability of irradiated cellulose and technical data to the filature industry

Volumetric and viscometric studies of amino acids in L-ascorbic acid aqueous solutions at T = (293.15 to 323.15) K

International Nuclear Information System (INIS)

Jiang, Xiaofeng; Zhu, Chunying; Ma, Youguang

2014-01-01

Graphical abstract: The densities and viscosities of L-alanine in L-ascorbic acid aqueous solutions at T = 293.15 K. Highlights: • Densities and viscosities of five amino acids in L-ascorbic acid aqueous solutions were measured. • Based on the experimental data, a series of volumetric and viscometric parameters were calculated. • The group additivity analysis has been applied to analyze the V φ 0 and B-coefficients. -- Abstract: Densities and viscosities of glycine, L-alanine, L-valine, L-threonine and L-arginine in aqueous solutions of (0.0, 0.1, 0.2, 0.3 and 0.4) mol · kg −1 L-ascorbic acid have been measured at T = (293.15, 303.15, 313.15 and 323.15) K under atmospheric pressure. The apparent molar volumes (V φ ), limiting partial molar volumes (V φ 0 ), limiting partial molar volumes of transfer (Δ tr V φ 0 ) and limiting partial molar expansibilities (E 2 0 ) were computed by densities. The extended Jones–Dole equation was used to correlate the viscosities in order to obtain viscosity B-coefficients and the free energies of activation per mole of solvent (Δμ 1 0≠ ) and solute (Δμ 2 0≠ ) were also calculated. The contributions of zwitterionic end group (NH 3 + , COO − ), CH 2 group, OH group and CNHNHNH 2 group to V φ 0 and viscosity B-coefficients were obtained through the group additivity analysis

Investigations to explore interactions in (polyhydroxy solute + L-ascorbic acid + H2O) solutions at different temperatures: Calorimetric and viscometric approach

International Nuclear Information System (INIS)

Banipal, Parampaul K.; Sharma, Mousmee; Aggarwal, Neha; Banipal, Tarlok S.

2016-01-01

Highlights: • The hydrophilic-hydrophilic interactions predominate at low temperatures. • Enthalpy change for polyol is less exothermic than its parent saccharide. • Δ dil C o p,2,m values suggest structural increase in presence of L-ascorbic acid. • Solutes act as kosmotropes in L-ascorbic acid (aq) solutions as indicated by dB/dT. - Abstract: Isothermal titration micro-calorimeter has been used to measure the enthalpy change (q) of polyhydroxy solutes [(+)-D-xylose, xylitol, (+)-D-glucose, 2-deoxy-D-glucose, (+)-methyl-α-D-glucopyranoside, and (+)-maltose monohydrate] in water and in (0.05, 0.15, and 0.25) mol·kg −1 L-ascorbic acid (aq) solutions at (288.15, 298.15, 308.15, and 318.15) K. Limiting enthalpies of dilution (Δ dil H°) of these solutes were calculated from heat evolved/absorbed during calorimetric experiments. Further thermodynamic quantities such as limiting enthalpies of dilution of transfer (Δ tr Δ dil H°), change in heat capacity (Δ dil C o p,2,m ), and pair (h AB ) and triplet (h ABB ) enthalpic interaction coefficients were also calculated and used to explore the nature of interactions of solutes with cosolute (L-ascorbic acid). The Jones-Dole viscosity B-coefficients for (+)-D-xylose, xylitol, (+)-D-galactose, galactitol, (+)-D-glucose, 2-deoxy-D-glucose, (+)-methyl-α-D-glucopyranoside, and (+)-maltose monohydrate in water and in (0.05, 0.15, 0.25, and 0.35) mol·kg −1 L-ascorbic acid (aq) solutions have been determined from viscosity (η) data measured over temperature range (288.15–318.15) K and at pressure, P = 101.3 kPa. The temperature dependence of B-coefficients (dB/dT), and viscosity B-coefficients of transfer (Δ tr B) of solutes from water to cosolute have also been estimated. These parameters have been discussed in terms of structure-making (kosmotropic) or -breaking (chaotropic) behavior of solutes.

Viscosity Prediction of Natural Gas Using the Friction Theory

DEFF Research Database (Denmark)

Zeberg-Mikkelsen, Claus Kjær; Cisneros, Sergio; Stenby, Erling Halfdan

2002-01-01

Based on the concepts of the friction theory (f-theory) for viscosity modeling, a procedure is introduced for predicting the viscosity of hydrocarbon mixtures rich in one component, which is the case for natural gases. In this procedure, the mixture friction coefficients are estimated with mixing...... rules based on the values of the pure component friction coefficients. Since natural gases contain mainly methane, two f-theory models are combined, where the friction coefficients of methane are estimated by a seven-constant f-theory model directly fitted to methane viscosities, and the friction...... coefficients of the other components are estimated by the one-parameter general f-theory model. The viscosity predictions are performed with the SRK, the PR, and the PRSV equations of state, respectively. For recently measured viscosities of natural gases, the resultant AAD (0.5 to 0.8%) is in excellent...

A Simple BODIPY-Based Viscosity Probe for Imaging of Cellular Viscosity in Live Cells

Directory of Open Access Journals (Sweden)

Dongdong Su

2016-08-01

Full Text Available Intracellular viscosity is a fundamental physical parameter that indicates the functioning of cells. In this work, we developed a simple boron-dipyrromethene (BODIPY-based probe, BTV, for cellular mitochondria viscosity imaging by coupling a simple BODIPY rotor with a mitochondria-targeting unit. The BTV exhibited a significant fluorescence intensity enhancement of more than 100-fold as the solvent viscosity increased. Also, the probe showed a direct linear relationship between the fluorescence lifetime and the media viscosity, which makes it possible to trace the change of the medium viscosity. Furthermore, it was demonstrated that BTV could achieve practical applicability in the monitoring of mitochondrial viscosity changes in live cells through fluorescence lifetime imaging microscopy (FLIM.

Vanishing viscosity limits of mixed hyperbolic–elliptic systems arising in multilayer channel flows

International Nuclear Information System (INIS)

Papaefthymiou, E S; Papageorgiou, D T

2015-01-01

This study considers the spatially periodic initial value problem of 2 × 2 quasi-linear parabolic systems in one space dimension having quadratic polynomial flux functions. These systems arise physically in the interfacial dynamics of viscous immiscible multilayer channel flows. The equations describe the spatiotemporal evolution of phase-separating interfaces with dissipation arising from surface tension (fourth-order) and/or stable stratification effects (second-order). A crucial mathematical aspect of these systems is the presence of mixed hyperbolic–elliptic flux functions that provide the only source of instability. The study concentrates on scaled spatially 2π-periodic solutions as the dissipation vanishes, and in particular the behaviour of such limits when generalized dissipation operators (spanning second to fourth-order) are considered. Extensive numerical computations and asymptotic analysis suggest that the existence (or not) of bounded vanishing viscosity solutions depends crucially on the structure of the flux function. In the absence of linear terms (i.e. homogeneous flux functions) the vanishing viscosity limit does not exist in the L ∞ -norm. On the other hand, if linear terms in the flux function are present the computations strongly suggest that the solutions exist and are bounded in the L ∞ -norm as the dissipation vanishes. It is found that the key mechanism that provides such boundedness centres on persistent spatiotemporal hyperbolic–elliptic transitions. Strikingly, as the dissipation decreases, the flux function becomes almost everywhere hyperbolic except on a fractal set of elliptic regions, whose dimension depends on the order of the regularized operator. Furthermore, the spatial structures of the emerging weak solutions are found to support an increasing number of discontinuities (measure-valued solutions) located in the vicinity of the fractally distributed elliptic regions. For the unscaled problem, such spatially

Construction of a high-temperature viscosimeter and measurement of the viscosity of melts of the system aluminium-nickel; Aufbau eines Hochtemperaturviskosimeters und Messung der Viskositaet von Schmelzen des Systems Aluminium-Nickel

Energy Technology Data Exchange (ETDEWEB)

Kehr, Mirko

2009-10-29

The system aluminium-nickel is of importance as a model-system in materials science as well as a basic system for superalloys in technical applications. The knowledge of the thermophysical properties of the system aluminium-nickel has been limited to the areas close to the pure elements mainly related to the high melting temperatures of up to 1638 C. The viscosity, which is one of these thermophysical properties, depends on alloy composition as well as on temperature. The viscosity is of importance as an input parameter in computer simulations and for improving casting processes of metallic alloys. The viscosity of aluminium-nickel melts has been measured only once so far. However, not the whole concentration range of the aluminium-nickel system was covered by these data. In particular the viscosity values of the high melting alloys, which are of technological interest, were unknown. The measurement of the missing values was not possible due to the high melting temperatures using existing viscometers. A new oscillating cup viscometer has been constructed within this work. The viscometer has been tested measuring the viscosity values of pure metals, which are well known in literature. The test measurements have been done at temperatures up to 1800 C. A temperature of 2300 C is achievable with slight modifications. A new software for controlling the device and evaluation of the measured data has been developed. Several working equations for calculating the viscosity have been implemented. Furthermore a new approach has been used for detecting the damping of the oscillation of the pendulum containing the liquid sample. The viscosity of aluminium-nickel melts have been measured successfully. The measured values are in good agreement with the little number of known values. A good agreement with values calculated from diffusion experiments and computer simulations was observed as well. Several models for calculating the viscosity of liquid alloys have been tested and

Hydrolysis of polyacrylamide containing associative hydrophobic groups: effect of the degree of hydrolysis and ionic strength on the viscosity in aqueous medium

International Nuclear Information System (INIS)

Lima, Bruna V. de; Vidal, Rosangela R.L.; Reis, Jeanne H.C. dos; Balaban, Rosangela de C.

2009-01-01

The HAPAM-10N polymer (hydrophobically modified and partially hydrolyzed polyacrylamide) was obtained by partial hydrolysis of HAPAM (hydrophobically modified polyacrylamide) precursor containing very low amount of hydrophobic groups (0.75%) in 0.1 M NaCl and 0.25 M NaOH aqueous solutions, at 40 deg C for 10 min. Hydrolysis degree of 44.64 % was obtained by 13 C NMR. The viscosity of polymers solutions was evaluated as a function of polymer concentration, ionic strength and temperature, at constant shear rate. The viscosity of HAPAM solutions increased with polymer concentration, however, it did not change significantly with the increase of ionic strength, and decreased with the temperature enhancement. The viscosity of HAPAM-10N solutions increased significantly in distilled water, due to electrostatic repulsions among carboxylate groups. However, with the increase of polymer concentration, ionic strength and temperature, it was not observed a significant increase of viscosity, probably due to the low amount of hydrophobic groups and high hydrolysis degree. (author)

Variation of velocity profile according to blood viscosity in a microfluidic channel

Science.gov (United States)

Yeom, Eunseop; Kang, Yang Jun; Lee, Sang-Joon

2014-11-01

The shear-thinning effect of blood flows is known to change blood viscosity. Since blood viscosity and motion of red blood cells (RBCs) are closely related, hemorheological variations have a strong influence on hemodynamic characteristics. Therefore, understanding on the relationship between the hemorheological and hemodynamic properties is importance for getting more detailed information on blood circulation in microvessels. In this study, the blood viscosity and velocity profiles in a microfluidic channel were systematically investigated. Rat blood was delivered in the microfluidic device which can measure blood viscosity by monitoring the flow-switching phenomenon. Velocity profiles of blood flows in the microchannel were measured by using a micro-particle image velocimetry (PIV) technique. Shape of velocity profiles measured at different flow rates was quantified by using a curve-fitting equation. It was observed that the shape of velocity profiles is highly correlated with blood viscosity. The study on the relation between blood viscosity and velocity profile would be helpful to understand the roles of hemorheological and hemodynamic properties in cardiovascular diseases. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIP) (No. 2008-0061991).

NVP melt/magma viscosity: insight on Mercury lava flows

Science.gov (United States)

Rossi, Stefano; Morgavi, Daniele; Namur, Olivier; Vetere, Francesco; Perugini, Diego; Mancinelli, Paolo; Pauselli, Cristina

2016-04-01

After more than four years of orbiting Mercury, NASA's MESSENGER spacecraft came to an end in late April 2015. MESSENGER has provided many new and surprising results. This session will again highlight the latest results on Mercury based on MESSENGER observations or updated modelling. The session will further address instrument calibration and science performance both retrospective on MESSENGER and on the ESA/JAXA BepiColombo mission. Papers covering additional themes related to Mercury are also welcomed. Please be aware that this session will be held as a PICO session. This will allow an intensive exchange of expertise and experience between the individual instruments and mission. NVP melt/magma viscosity: insight on Mercury lava flows S. Rossi1, D. Morgavi1, O. Namur2, D. Perugini1, F.Vetere1, P. Mancinelli1 and C. Pauselli1 1 Dipartimento di Fisica e Geologia, Università di Perugia, piazza Università 1, 06123 Perugia, Italy 2 Uni Hannover Institut für Mineralogie, Leibniz Universität Hannover, Callinstraβe 3, 30167 Hannover, Germany In this contribution we report new measurements of viscosity of synthetic komatitic melts, used the behaviour of silicate melts erupted at the surface of Mercury. Composition of Mercurian surface magmas was calculated using the most recent maps produced from MESSENGER XRS data (Weider et al., 2015). We focused on the northern hemisphere (Northern Volcanic Province, NVP, the largest lava flow on Mercury and possibly in the Solar System) for which the spatial resolution of MESSENGER measurements is high and individual maps of Mg/Si, Ca/Si, Al/Si and S/Si were combined. The experimental starting material contains high Na2O content (≈7 wt.%) that strongly influences viscosity. High temperature viscosity measurements were carried out at 1 atm using a concentric cylinder apparatus equipped with an Anton Paar RheolabQC viscometer head at the Department of Physics and Geology (PVRG_lab) at the University of Perugia (Perugia, Italy

Experimental study of electric conductivity, density and viscosity of Wood's alloy

International Nuclear Information System (INIS)

Kazandzhan, B.I.; Matveev, V.M.; Savich, T.B.; Umarov, A.M.

1989-01-01

Electric conductivity, density and kinematic viscosity of commercially pure Wood's alloy are obtained in a wide temperature range. Electric conductivity and density are investigated from the room temperature to 1000 K. Measurements of kinematic viscosity are carried out from 372 to 1000 K by means of torsional vibrations method using informatiom computer system permitting to automate data acquisition and processing and to increase the measurement accuracy. On the basis of analysis the character of electric conductivity and kinematic viscosity polyterms Wood's alloy liquidus and solidus temperatures are estimated

Time Dependent and Steady Uni-axial Elongational Viscosity

DEFF Research Database (Denmark)

Nielsen, Jens K.; Rasmussen, Henrik Koblitz; Hassager, Ole

2005-01-01

Here we present measurements of transient and steady uni-axial elongational viscosity, using the Filament Stretching Rheometer1 or FSR1 (see Fig. 1) of the following melts: Four narrow MMD polystyrene (PS) samples with weight-average molar mass Mw in the range of 50k to 390k. Three different bi......-disperse samples, mixed from the narrow MMD PS. Two low-density polyethylene (LDPE) melts (Lupolen 1840D and 3020D). A steady-state viscosity was kept for 1-2.5 Hencky strain units in all measurements....

Blood viscosity during coagulation at different shear rates

Science.gov (United States)

Ranucci, Marco; Laddomada, Tommaso; Ranucci, Matteo; Baryshnikova, Ekaterina

2014-01-01

Abstract During the coagulation process, blood changes from a liquid to a solid gel phase. These changes are reflected by changes in blood viscosity; however, blood viscosity at different shear rates (SR) has not been previously explored during the coagulation process. In this study, we investigated the viscosity changes of whole blood in 10 subjects with a normal coagulation profile, using a cone‐on‐plate viscosimeter. For each subject, three consecutive measurements were performed, at a SR of 20, 40, 80 sec−1. On the basis of the time‐dependent changes in blood viscosity, we identified the gel point (GP), the time‐to‐gel point (TGP), the maximum clot viscosity (MCV), and the clot lysis half‐time (CLH). The TGP significantly (P = 0.0023) shortened for increasing SR, and was significantly associated with the activated partial thromboplastin time at a SR of 20 sec−1 (P = 0.038) and 80 sec−1 (P = 0.019). The MCV was significantly lower at a SR of 80 sec−1 versus 40 sec−1 (P = 0.027) and the CLH significantly (P = 0.048) increased for increasing SR. These results demonstrate that measurement of blood viscosity during the coagulation process offers a number of potentially useful parameters. In particular, the association between the TGP and the activated partial thromboplastin time is an expression of the clotting time (intrinsic and common pathway), and its shortening for increasing SR may be interpreted the well‐known activating effects of SR on platelet activation and thrombin generation. Further studies focused on the TGP under conditions of hypo‐ or hypercoagulability are required to confirm its role in the clinical practice. PMID:24994896

Suitability of thermoluminescence, chemiluminescence, ESR and viscosity measurements as detection method for the irradiation of medicinal herbs

International Nuclear Information System (INIS)

Schuettler, C.; Gebhardt, G.; Stock, A.; Helle, N.; Boegl, K.W.

1993-01-01

Chemiluminescence, electron spin resonance, thermoluminescence and viscosity measurements have been investigated for their suitability as detection method for the irradiation of the medicinal herbs anise seeds (anisi fructus), valerian roots (valerianae radix), redberry leaves (uvae ursi folium), birch leaves (betulae folium), greek hay seeds (foenugraeci semen), cayenne pepper (capsici fructus acer), black-aldertee bark (frangulae cortex), fennel fruits (feoniculi fructus), rose hip shells (cynosbati fructus), coltsfoot (farfarae folium), acorus roots (calami rhizoma), chamomile flowers (matricariae flos), caraway (carvi fructus), lavender flowers (lavandulae flos), linseed (lini semen), lime tree flowers (tiliae flos), St. Mary's thistle fruit (cardui mariae herba), lemon balm (melissae folium), java tea (orthosiphonis folium), peppermint (menthae piperitae folium), sage leaves (salviae folium), scouring rush (equiseti herba), senna leaves (sennae folium), plantain herbs (plantaginis lanceolata herba), thyme herbs (thymi herba), juniper berries (juniperi fructus), hawthorne herbs (crataegi folium), wheat starch (amylum tritici) and wormwood (absinthii herba). Depending on the herbs, the methods used were more or less suitable. Chemiluminescence measurements showed the smallest differences between untreated and irradiated samples whereas thermoluminescence measurements on isolated minerals from the vegetable drugs gave better results. In some herbs radiation-specific radicals could be identified by ESR spectroscopy. Viscosity measurement is suitable for some herbs as fast and inexpensive method for screening. (orig.) [de

Viscosity of diluted suspensions of vegetal particles in water

Directory of Open Access Journals (Sweden)

Szydłowska Adriana

2017-01-01

Full Text Available Viscosity and rheological behaviour of sewage as well as sludge are essential while designing apparatuses and operations employed in the sewage treatment process and its processing. With reference to these substances, the bio-suspensions samples of three size fractions ((i 150÷212 μm, (ii 106÷150 μm and (iii below106 μm of dry grass in water with solid volume fraction 8%, 10% and 11% were prepared. After twenty four hours prior to their preparation time, the suspension samples underwent rheometeric measurements with the use of a rotational rheometer with coaxial cylinders. On the basis of the obtained results, flow curves were plotted and described with both the power model and Herschel-Bulkley model. Moreover, the viscosity of the studied substances was determined that allowed to conclude that the studied bio-suspensions display features of viscoelastic fluids. The experimentally established viscosity was compared to the calculated one according to Manley and Manson equation, recommended in the literature. It occurred that the measured viscosity values substantially exceed the calculation viscosity values, even by 105 times. The observations suggest that it stems from water imbibition of fibrous vegetal particles, which causes their swelling and decreases the amount of liquid phase in the suspension.

In situ viscosity of oil sands using low field NMR

International Nuclear Information System (INIS)

Bryan, J.; Moon, D.; Kantzas, A.

2005-01-01

In heavy oil and bitumen reservoirs, oil viscosity is a vital piece of information that will have great bearing on the chosen EOR scheme and the recovery expected. Prediction of in situ viscosity with a logging tool would he very beneficial in reservoir characterization and exploitation design. Low field NMR is a technology that has shown great potential as a tool for characterizing hydrocarbon properties in heavy oil and bitumen reservoirs. An oil viscosity correlation has previously been developed that is capable of providing order of magnitude viscosity estimates for a wide range of oils taken from various fields in Alberta. This paper presents tuning procedures to improve the NMR predictions for different viscosity ranges, and extends the NMR viscosity model to in situ heavy oil in unconsolidated sands. The results of this work show that the NMR oil peak can be de-convoluted from the in situ signals of the oil and water, and the bulk viscosity correlation that was developed for bulk oils can he applied to predict the in situ oil viscosity. These results can be translated to an NMR logging tool algorithm, allowing for in situ measurements of oil viscosity at the proper reservoir conditions. (author)

The Impact of Waste Loading on Viscosity in the Frit 418-SB3 System

International Nuclear Information System (INIS)

PEELER, DAVID

2004-01-01

In this report, data are provided to gain insight into the potential impact of a lower viscosity glass on melter stability (i.e., pressure spikes, cold cap behavior) and/or pour stream stability. High temperature viscosity data are generated for the Frit 418-SB3 system as a function of waste loading (from 30 to 45 percent) and compared to similar data from other systems that have been (or are currently being) processed through the Defense Waste Processing Facility (DWPF) melter. The data are presented in various formats to potentially align the viscosity data with physical observations at various points in the melter system or critical DWPF processing unit operations. The expectations is that the data will be provided adequate insight into the vitrification parameters which might evolve into working solutions as DWPF strives to maximize waste throughput. This report attempts to provide insight into a physical interpretation of the data from a DWPF perspective. The theories present ed are certainly not an all inclusive list and the order in which they are present does imply a ranking, probability, or likelihood that the proposed theory is even plausible. The intent of this discussion is to provide a forum in which the viscosity data can be discussed in relation to possible mechanisms which could potentially lead to a workable solution as discussed in relation to possible solution as higher overall attainment is striven for during processing of the current or future sludge batches

Estimation of shear viscosity based on transverse momentum correlations

International Nuclear Information System (INIS)

Sharma, Monika

2009-01-01

Event anisotropy measurements at RHIC suggest the strongly interacting matter created in heavy ion collisions flows with very little shear viscosity. Precise determination of 'shear viscosity-to-entropy' ratio is currently a subject of extensive study [S. Gavin and M. Abdel-Aziz, Phys. Rev. Lett. 97 (2006) 162302]. We present preliminary results of measurements of the evolution of transverse momentum correlation function with collision centrality of Au+Au interactions at √(s NN )=200 GeV. We compare two differential correlation functions, namely inclusive [J. Adams et al. (STAR Collaboration), Phys. Rev. C 72 (2005) 044902] and a differential version of the correlation measure C introduced by Gavin et al. [S. Gavin and M. Abdel-Aziz, Phys. Rev. Lett. 97 (2006) 162302; M. Sharma and C. A. Pruneau, Phys. Rev. C 79 (2009) 024905.]. These observables can be used for the experimental study of the shear viscosity per unit entropy.

Estimation of shear viscosity based on transverse momentum correlations

Science.gov (United States)

STAR Collaboration; Sharma, Monika; STAR Collaboration

2009-11-01

Event anisotropy measurements at RHIC suggest the strongly interacting matter created in heavy ion collisions flows with very little shear viscosity. Precise determination of “shear viscosity-to-entropy” ratio is currently a subject of extensive study [S. Gavin and M. Abdel-Aziz, Phys. Rev. Lett. 97 (2006) 162302]. We present preliminary results of measurements of the evolution of transverse momentum correlation function with collision centrality of Au+Au interactions at s=200 GeV. We compare two differential correlation functions, namely inclusive [J. Adams et al. (STAR Collaboration), Phys. Rev. C 72 (2005) 044902] and a differential version of the correlation measure C˜ introduced by Gavin et al. [S. Gavin and M. Abdel-Aziz, Phys. Rev. Lett. 97 (2006) 162302; M. Sharma and C. A. Pruneau, Phys. Rev. C 79 (2009) 024905.]. These observables can be used for the experimental study of the shear viscosity per unit entropy.

Plugging solution

Energy Technology Data Exchange (ETDEWEB)

Sharipov, A U; Yangirov, I Z

1982-01-01

A clay-powder, cement, and water-base plugging solution is proposed having reduced solution viscosity characteristics while maintaining tensile strength in cement stone. This solution utilizes silver graphite and its ingredients, by mass weight, are as follows: cement 51.2-54.3%; claypowder 6.06-9.1%; silver graphite 0.24-0.33%; with water making up the remainder.

Refractive index and viscosity: dual sensing with plastic fibre gratings

Science.gov (United States)

Ferreira, Ricardo; Bilro, Lúcia; Marques, Carlos; Oliveira, Ricardo; Nogueira, Rogério

2014-05-01

A refractive index and viscosity sensor based on FBGs in mPOF is reported for the first time. The refractive index was measured with a sensitivity of -10:98nm=RIU and a resolution of 1 - 10-4RIU. Viscosity measurements were performed with acousto-optic modulation, obtaining a sensitivity of -94:42%=mPa • s and a resolution of 0:06mPa • s.

A Viscosity-Based Model for Bubble-Propelled Catalytic Micromotors

Directory of Open Access Journals (Sweden)

Zhen Wang

2017-06-01

Full Text Available Micromotors have shown significant potential for diverse future applications. However, a poor understanding of the propelling mechanism hampers its further applications. In this study, an accurate mechanical model of the micromotor has been proposed by considering the geometric asymmetry and fluid viscosity based on hydrodynamic principles. The results obtained from the proposed model are in a good agreement with the experimental results. The effects of the semi-cone angle on the micromotor are re-analyzed. Furthermore, other geometric parameters, like the length-radius aspect ratio, exert great impact on the velocity. It is also observed that micromotors travel much slower in highly viscous solutions and, hence, viscosity plays an important role.

Viscosity sinergism of hydrozypropmethyl and carboxy methyl cellulose

Directory of Open Access Journals (Sweden)

Katona Jaroslav M.

2008-01-01

Full Text Available Rheology modifiers are common constituents of food, cosmetic and pharmaceutic products. Often, by using two or more of them, better control of the product rheological properties can be achieved. In this work, rheological properties of hydroxypropymethyl cellulose (HPMC and sodium carboxymethyl cellulose (NaCMC solutions of different concentrations were investigated and compared to the flow properties of 1% HPMC/NaCMC binary mixtures at various HPMC/NaCMC mass ratios. Solutions of HPMC and NaCMC were found to be pseudoplastic, where pseudoplasticity increases with increase in the macromolecules concentration. Changes of the degree of pseudoplasticity, n as well as the coefficient of consistency, K with the concentration are more pronounced in HPMC solutions when compared to the NaCMC ones. This is mostly due to the ability of HPMC molecules to associate with each other at concentrations above critical overlap concentration, c , and greater flexibility of macromolecular chains. Binary mixtures of HPMC/NaCMC were also found to be pseudoplastic. Experimentally obtained viscosities of the mixture were proved to be larger than theoretically expected ones, indicating viscosity synergism as a consequence of HPMC-NaCMC interaction. Maximum in synergy was observed when HPMC/NaCMC mass ratio was 0.4/0.6, no matter of the shear rate applied. On the other hand, it was found that relative positive deviation, RPD decreases when shear rate is increased.

Technical Note: New methodology for measuring viscosities in small volumes characteristic of environmental chamber particle samples

Directory of Open Access Journals (Sweden)

L. Renbaum-Wolff

2013-01-01

Full Text Available Herein, a method for the determination of viscosities of small sample volumes is introduced, with important implications for the viscosity determination of particle samples from environmental chambers (used to simulate atmospheric conditions. The amount of sample needed is < 1 μl, and the technique is capable of determining viscosities (η ranging between 10⁻³ and 10³ Pascal seconds (Pa s in samples that cover a range of chemical properties and with real-time relative humidity and temperature control; hence, the technique should be well-suited for determining the viscosities, under atmospherically relevant conditions, of particles collected from environmental chambers. In this technique, supermicron particles are first deposited on an inert hydrophobic substrate. Then, insoluble beads (~1 μm in diameter are embedded in the particles. Next, a flow of gas is introduced over the particles, which generates a shear stress on the particle surfaces. The sample responds to this shear stress by generating internal circulations, which are quantified with an optical microscope by monitoring the movement of the beads. The rate of internal circulation is shown to be a function of particle viscosity but independent of the particle material for a wide range of organic and organic-water samples. A calibration curve is constructed from the experimental data that relates the rate of internal circulation to particle viscosity, and this calibration curve is successfully used to predict viscosities in multicomponent organic mixtures.

Errors detection in viscosity temperature measurements. Pt. B. Results, usefullness. Fehlersuche bei Viskositaet-Temperatur-Messungen. T. B. Resultate, Nuetzlichkeit

Energy Technology Data Exchange (ETDEWEB)

Schwen, R. (BASF, Farbenlaboratorium, Ludwigshafen am Rhein (Germany)); Puhl, H. (BASF, Ammoniaklaboratorium, Ludwigshafen am Rhein (Germany))

1992-06-01

The temperature dependence of the viscosity spreads often over a large range. It can be measured with less then one per cent error with usual effort, but the result cannot yet be controlled to the same accuracy: Graphic methods are far too incorrect and the numerous approximate equations given in literature do not adequately represent the true shape of the curves of all types of substances at the whole range of interesting temperatures. The different slopes and curvatures of the temperature dependence of the dynamic and kinematic viscosities can now be represented by means of one-term or multi-term exponential-functions with a maximum of eight coefficients. The Antoine equation is included in this investigation and the Ubbelohde-Walter-equation for comparison only. Tests on more than 400 data sets show, that there is no single equation to cope with all existing slopes. The numerical values of the coefficients are determined by the Marquardt statistical search method; the starting values are obtained by fixed rules. Using a non-linear regression of exponential sums, the method exactly describes the viscosity-temperature-behavior of normal liquids and real gases as well as the supercritical region over any desired range starting with four measured values and being complete with nine measured values or more; it allows tabellation, interpolation and, with caution, extrapolation. In the first part published, the problem and the mathematic procedure were discussed. The following publication presents the results and considers the applicability. (orig.).

Viscosity change of coal during carbonization; Sekitan tanka hannochu no nendo henka

Energy Technology Data Exchange (ETDEWEB)

Matsuoka, K.; Hayashi, J.; Kumagai, H.; Chiba, T. [Hokkaido University, Sapporo (Japan). Center for Advanced Research of Energy Technology

1996-10-28

In relation to softening, melting and solidification of coal during heating, the effect of heating rate and nitrogen gas pressure on viscosity change, and change with time in the yield of pyridine extract were measured to study the mechanism of viscosity change. In experiment, six kinds of coals were used, and their needle penetration and dilatation were measured using compacted disk coal pellets. The coking and slight coking coal heat-treated under the same condition as the above experiment were used for pyridine extraction. As the experimental result, the apparent viscosity during coal heating was dependent on heating rate, nitrogen pressure and coal kinds. The minimum apparent viscosity decreased with an increase in heating rate and nitrogen pressure, and approached to a constant value. Like apparent viscosity change, the yield of pyridine extract was also dependent on heating rate, and its temperature range nearly agreed with that of apparent viscosity change. It was suggested that the viscosity is dependent on not only the mass fraction of plastic intermediate but also temperature and the relation between plastic intermediate and other components. 3 refs., 5 figs., 1 tab.

WCSPH with Limiting Viscosity for Modeling Landslide Hazard at the Slopes of Artificial Reservoir

Directory of Open Access Journals (Sweden)

Sauro Manenti

2018-04-01

Full Text Available This work illustrated an application of the FOSS code SPHERA v.8.0 (RSE SpA, Milano, Italy to the simulation of landslide hazard at the slope of a water basin. SPHERA is based on the weakly compressible SPH method (WCSPH and holds a mixture model, consistent with the packing limit of the Kinetic Theory of Granular Flow (KTGF, which was previously tested for simulating two-phase free-surface rapid flows involving water-sediment interaction. In this study a limiting viscosity parameter was implemented in the previous formulation of the mixture model to limit the growth of the apparent viscosity, thus saving computational time while preserving the solution accuracy. This approach is consistent with the experimental behavior of high polymer solutions for which an almost constant value of viscosity may be approached at very low deformation rates near the transition zone of elastic–plastic regime. In this application, the limiting viscosity was used as a numerical parameter for optimization of the computation. Some preliminary tests were performed by simulating a 2D erosional dam break, proving that a proper selection of the limiting viscosity leads to a considerable drop of the computational time without altering significantly the numerical solution. SPHERA was then validated by simulating a 2D scale experiment reproducing the early phase of the Vajont landslide when a tsunami wave was generated that climbed the opposite mountain side with a maximum run-up of about 270 m. The obtained maximum run-up was very close to the experimental result. Influence of saturation of the landslide material below the still water level was also accounted, showing that the landslide dynamics can be better represented and the wave run-up can be properly estimated.

Solution properties of hydrophobically modified

Directory of Open Access Journals (Sweden)

A.M. Al-Sabagh

2016-12-01

Full Text Available We tested nine hydrophobically modified polyacrylamides with molecular weights situated between 1.58 and 0.89 × 106 g/mol for enhanced oil recovery applications. Their solution properties were investigated in the distilled water, brine solution, formation water and sea water. Their critical association concentrations were determined from the relationship between their concentrations and the corresponding apparent viscosities (ηapp at 30 °C at shear rate 6 s−1. They were between 0.4 and 0.5 g/dl. The brine solutions of 0.5 g/dl of HM-PAMs were investigated at different conditions regarding their apparent viscosities. Such conditions were mono and divalent cations, temperature ranging from 30 to 90 °C, the shear rate ranging from 6 to 30 s−1 and the aging time for 45 days. The surface and interfacial tensions for the HM-PAMs were measured for concentration range from 0.01 to 1 g/dl brine solutions at 30 °C and their emulsification efficiencies were investigated for 7 days. The discrepancy in the properties and efficiencies of the tested copolymers was discussed in the light of their chemical structure.

Determining Quiescent Colloidal Suspension Viscosities Using the Green-Kubo Relation and Image-Based Stress Measurements

Science.gov (United States)

Lin, Neil Y. C.; Bierbaum, Matthew; Cohen, Itai

2017-09-01

By combining confocal microscopy and stress assessment from local structural anisotropy, we directly measure stresses in 3D quiescent colloidal liquids. Our noninvasive and nonperturbative method allows us to measure forces ≲50 fN with a small and tunable probing volume, enabling us to resolve the stress fluctuations arising from particle thermal motions. We use the Green-Kubo relation to relate these measured stress fluctuations to the bulk Brownian viscosity at different volume fractions, comparing against simulations and conventional rheometry measurements. We find that the Green-Kubo analysis gives excellent agreement with these prior results, suggesting that similar methods could be applied to investigations of local flow properties in many poorly understood far-from-equilibrium systems, including suspensions that are glassy, strongly sheared, or highly confined.

Temperature dependent kinematic viscosity of different types of engine oils

Directory of Open Access Journals (Sweden)

Libor Severa

2009-01-01

Full Text Available The objective of this study is to measure how the viscosity of engine oil changes with temperature. Six different commercially distributed engine oils (primarily intended for motorcycle engines of 10W–40 viscosity grade have been evaluated. Four of the oils were of synthetic type, two of semi–synthetic type. All oils have been assumed to be Newtonian fluids, thus flow curves have not been determined. Oils have been cooled to below zero temperatures and under controlled temperature regulation, kinematic viscosity (mm2 / s have been measured in the range of −5 °C and +115 °C. Anton Paar digital viscometer with concentric cylinders geometry has been used. In accordance with expected behavior, kinematic viscosity of all oils was decreasing with increasing temperature. Viscosity was found to be independent on oil’s density. Temperature dependence has been modeled using se­ve­ral mathematical models – Vogel equation, Arrhenius equation, polynomial, and Gaussian equation. The best match between experimental and computed data has been achieved for Gaussian equation (R2 = 0.9993. Knowledge of viscosity behavior of an engine oil as a function of its temperature is of great importance, especially when considering running efficiency and performance of combustion engines. Proposed models can be used for description and prediction of rheological behavior of engine oils.

Characterizing Vibrating Cantilevers for Liquid Viscosity and Density Sensing

Directory of Open Access Journals (Sweden)

Bernhard Jakoby

2008-10-01

Full Text Available Miniaturized liquid sensors are essential devices in online process or condition monitoring. In case of viscosity and density sensing, microacoustic sensors such as quartz crystal resonators or SAW devices have proved particularly useful. However, these devices basically measure a thin-film viscosity, which is often not comparable to the macroscopic parameters probed by conventional viscometers. Miniaturized cantilever-based devices are interesting alternatives for such applications, but here the interaction between the liquid and the oscillating beam is more involved. In our contribution, we describe a measurement setup, which allows the investigation of this interaction for different beam cross-sections. We present an analytical model based on an approximation of the immersed cantilever as an oscillating sphere comprising the effective mass and the intrinsic damping of the cantilever and additional mass and damping due to the liquid loading. The model parameters are obtained from measurements with well-known sample liquids by a curve fitting procedure. Finally, we present the measurement of viscosity and density of an unknown sample liquid, demonstrating the feasibility of the model.

Viscosity characteristics of selected volcanic rock melts

Science.gov (United States)

Hobiger, Manuel; Sonder, Ingo; Büttner, Ralf; Zimanowski, Bernd

2011-02-01

A basic experimental study of the behavior of magma rheology was carried out on remelted volcanic rocks using wide gap viscometry. The complex composition of magmatic melts leads to complicated rheologic behavior which cannot be described with one simple model. Therefore, measurement procedures which are able to quantify non-Newtonian behavior have to be employed. Furthermore, the experimental apparatus must be able to deal with inhomogeneities of magmatic melts. We measured the viscosity of a set of materials representing a broad range of volcanic processes. For the lower viscous melts (low-silica compositions), non-Newtonian behavior is observed, whereas the high-silica melts show Newtonian behavior in the measured temperature and shear rate range (T = 1423 K - 1623 K, γ˙ = 10 - 2 s - 1 - 20 s - 1 ). The non-Newtonian materials show power-law behavior. The measured viscosities η and power-law indexes m lie in the intervals 8 Pa s ≤ η ≤ 210 3 Pa s, 0.71 ≤ m ≤ 1.0 (Grímsvötn basalt), 0.9 Pa s ≤ η ≤ 350 Pa s, 0.61 ≤ m ≤ 0.93 (Hohenstoffeln olivine-melilitite), and 8 Pa s ≤ η ≤ 1.510 4 Pa s, 0.55 ≤ m ≤ 1.0 (Sommata basalt). Measured viscosities of the Newtonian high-silica melts lie in the range 10 4 Pa s ≤ η ≤ 310 5 Pa s.

Viscosity and volume properties of the Al-Cu melts

Directory of Open Access Journals (Sweden)

Kurochkin A.

2011-05-01

Full Text Available Temperature dependences of the kinematic viscosity v and the density ρ of Al-Cu melts were investigated in the same regime taking into account that viscometric experiments with the melts enriched with cupper have not been repeated since 1960th and densimetric measurements did not perform before at all. The first measurements were fulfilled using the method of dumping oscillation of a crucible filled in by a melt investigated. Its precision was as high as 1.5%. Density was measured using the gamma-absorption method with the accuracy of 0.2 to 0.3%. Crucibles of BeO were used in both the cases. In the course of the measurements a distinct branching of the heating and cooling curves were fixed below some temperature characteristic of each composition for most of the investigated samples. The branching temperature systematically changes with growth of cupper content. The authors believe that the effect is caused by the irreversible transition of the melts from microheterogeneous state inherited from the initial rough materials into a true solution state.

Suppression of steam explosions in tin and Fe-Al2O3 melts by increasing the viscosity of the coolant

International Nuclear Information System (INIS)

Nelson, L.S.; Guay, K.P.

1986-01-01

Steam explosions, energetic interactions that sometimes occur when a melt and water come together, can be suppressed by increasing the viscosity of the aqueous phase. This has been demonstrated both in the laboratory with drops of molten tin released into aqueous glycerol or cellulose gum solutions, and in one field-scale experiment where 50 kg of molten Fe-Al 2 O 3 was released into a cellulose gum solution; vigorous spontaneous explosions occurred in both situations when the cold liquid was water alone. There is a threshold solution viscosity near 0.015 Pa s, above which spontaneous tin drop explosions no longer occur. Increase of coolant viscosity might prevent injury to workers and damage to equipment in industrial processes where melts are normally handled near cooling water. (author)

Predicting the glass transition temperature and viscosity of secondary organic material using molecular composition

Science.gov (United States)

Wong DeRieux, Wing-Sy; Li, Ying; Lin, Peng; Laskin, Julia; Laskin, Alexander; Bertram, Allan K.; Nizkorodov, Sergey A.; Shiraiwa, Manabu

2018-05-01

Secondary organic aerosol (SOA) accounts for a large fraction of submicron particles in the atmosphere. SOA can occur in amorphous solid or semi-solid phase states depending on chemical composition, relative humidity (RH), and temperature. The phase transition between amorphous solid and semi-solid states occurs at the glass transition temperature (Tg). We have recently developed a method to estimate Tg of pure compounds containing carbon, hydrogen, and oxygen atoms (CHO compounds) with molar mass less than 450 g mol-1 based on their molar mass and atomic O : C ratio. In this study, we refine and extend this method for CH and CHO compounds with molar mass up to ˜ 1100 g mol-1 using the number of carbon, hydrogen, and oxygen atoms. We predict viscosity from the Tg-scaled Arrhenius plot of fragility (viscosity vs. Tg/T) as a function of the fragility parameter D. We compiled D values of organic compounds from the literature and found that D approaches a lower limit of ˜ 10 (±1.7) as the molar mass increases. We estimated the viscosity of α-pinene and isoprene SOA as a function of RH by accounting for the hygroscopic growth of SOA and applying the Gordon-Taylor mixing rule, reproducing previously published experimental measurements very well. Sensitivity studies were conducted to evaluate impacts of Tg, D, the hygroscopicity parameter (κ), and the Gordon-Taylor constant on viscosity predictions. The viscosity of toluene SOA was predicted using the elemental composition obtained by high-resolution mass spectrometry (HRMS), resulting in a good agreement with the measured viscosity. We also estimated the viscosity of biomass burning particles using the chemical composition measured by HRMS with two different ionization techniques: electrospray ionization (ESI) and atmospheric pressure photoionization (APPI). Due to differences in detected organic compounds and signal intensity, predicted viscosities at low RH based on ESI and APPI measurements differ by 2-5 orders

Experimental density, viscosity, interfacial tension and water solubility of ethyl benzene-α-methyl benzyl alcohol–water system

International Nuclear Information System (INIS)

Barega, Esayas W.; Zondervan, Edwin; Haan, André B. de

2013-01-01

Highlights: • Properties were measured for MBA (methyl benzyl alcohol)-EB (ethyl benzene)-water. • MBA concentration was found to influence all the properties strongly. • The water solubility, density, and viscosity increased at high MBA concentration. • The interfacial tension decreased sharply at high MBA concentration. • MBA dictates the phase separation and mass transfer of the ternary system. -- Abstract: Density, viscosity, interfacial tension, and water solubility were measured for the (α-methyl benzyl alcohol (MBA) + Ethyl benzene (EB)) system at different concentrations of MBA in contact with water and sodium hydroxide solution (0.01 mol · kg −1 ) as aqueous phases. The properties were measured to identify the component which plays a governing role in changing the physical properties relevant to mass transfer and phase separation of the ternary system. The concentration of MBA was found to be the major factor influencing all the properties. The water solubility, the density, and the viscosity increased notably at higher concentrations of MBA; while, the interfacial tension decreased strongly. The use of 0.01 mol · kg −1 NaOH as an aqueous phase resulted in a decrease of the interfacial tension and a minor decrease in the water solubility. The density data were correlated using a quadratic mixing rule to describe the influence of concentration at any temperature. The viscosity data are correlated using the Nissan and Grunberg and Katti-Chaudhri equations. The Szyzkowski’s equation was used to correlate the interfacial tension data. The water solubility data were described using an exponential relationship. All the correlations described the experimental physical property data adequately

Solution properties and taste behavior of lactose monohydrate in aqueous ascorbic acid solutions at different temperatures: Volumetric and rheological approach.

Science.gov (United States)

Sarkar, Abhijit; Sinha, Biswajit

2016-11-15

The densities and viscosities of lactose monohydrate in aqueous ascorbic acid solutions with several molal concentrations m=(0.00-0.08)molkg(-1) of ascorbic acid were determined at T=(298.15-318.15)K and pressure p=101kPa. Using experimental data apparent molar volume (ϕV), standard partial molar volume (ϕV(0)), the slope (SV(∗)), apparent specific volumes (ϕVsp), standard isobaric partial molar expansibility (ϕE(0)) and its temperature dependence [Formula: see text] the viscosity B-coefficient and solvation number (Sn) were determined. Viscosity B-coefficients were further employed to obtain the free energies of activation of viscous flow per mole of the solvents (Δμ1(0≠)) and of the solute (Δμ2(0≠)). Effects of molality, solute structure and temperature and taste behavior were analyzed in terms of solute-solute and solute-solvent interactions; results revealed that the solutions are characterized predominantly by solute-solvent interactions and lactose monohydrate behaves as a long-range structure maker. Copyright © 2016 Elsevier Ltd. All rights reserved.

An exploration of viscosity models in the realm of kinetic theory of liquids originated fluids

Science.gov (United States)

Hussain, Azad; Ghafoor, Saadia; Malik, M. Y.; Jamal, Sarmad

The preeminent perspective of this article is to study flow of an Eyring Powell fluid model past a penetrable plate. To find the effects of variable viscosity on fluid model, continuity, momentum and energy equations are elaborated. Here, viscosity is taken as function of temperature. To understand the phenomenon, Reynold and Vogel models of variable viscosity are incorporated. The highly non-linear partial differential equations are transfigured into ordinary differential equations with the help of suitable similarity transformations. The numerical solution of the problem is presented. Graphs are plotted to visualize the behavior of pertinent parameters on the velocity and temperature profiles.

Elongational viscosity of monodisperse and bidisperse polystyrene melts

DEFF Research Database (Denmark)

Nielsen, Jens Kromann; Rasmussen, Henrik Koblitz; Hassager, Ole

2005-01-01

The startup and steady uniaxial elongational viscosity have been measured for two monodisperse polystyrene melts with molecular weights of 52 kg/mole (PS52K) and 103 kg/mole (PS103K), and for three bidisperse polystyrene melts. The bidisperse melts consist of PS103K or PS52K and a monodisperse...... (closed loop proportional regulator) using the laser in such a way that the stretch rate at the neck is kept constant. The rheometer has been described in more detail in (A. Bach, H.K. Rasmussen and O. Hassager, Journal of Rheology, 47 (2003) 429). PS390K show a decrease in the steady viscosity as a power......-law function of the elongational rate (A. Bach, K. Almdal, H.K. Rasmussen and O. Hassager, Macromolecules 36 (2003) 5174). PS52K and PS103K show that the steady viscosity has a maximum that is respectively 100% and 50% above 3 times the zero-shear-rate viscosity. The bidisperse melts show a significant...

Influence of starch origin on rheological properties of concentrated aqueous solutions

Directory of Open Access Journals (Sweden)

Stojanović Željko P.

2011-01-01

Full Text Available The rheological properties of corn and potato starch concentrated aqueous solutions were investigated at 25ºC. The starches were previously dispersed in water and the solutions were obtained by heating of dispersions at 115-120ºC for 20 minutes. The solutions of potato starch were transparent, while the corn starch solutions were opalescent. The results of dynamic mechanical measurements showed that the values of viscosity, h, storage modulus, G′, and loss modulus, G″, of the corn starch solutions increased with the storage time. This phenomenon was not observed for the potato starch solutions. It was assumed that the increase of h, G′ and G″ is the result of starch solutions retrogradation. The potato starch solutions retrogradation did not occur probably because of the phosphates presence. The viscosity of 2 mass % corn starch solution is less than the viscosity of 2 mass % potato starch solution. By increasing the concentration of corn starch solution the gel with elastic behavior was formed. The corn starch solutions formed gel as early as at 4 mass % concentration, while potato starch solutions achieved the gel state at the concentration of 5 mass %. The value of exponent m (G′ and G″ µ wm during the transition of potato starch solutions to gel is 0.414, which gives the fractal dimensions for corn starch of 2.10. The obtained value of fractal dimension corresponds to slow aggregation. The corn starch solutions with the starch concentrations higher than 4 mass % form weak gels. For these solutions the values of modulus in rubber plateau were determined. It was found that the modulus in rubber plateau increased with the concentration by the exponent of 4.36. Such high exponent value was obtained in the case when the tridimensional network is formed, i.e. when supermolecular structures like associates or crystal domains are formed.

Heritability and Seasonal Changes in Viscosity of Slash Pine Oleoresin

Science.gov (United States)

Robert D. McReynolds

1971-01-01

Oleoresin viscosity was measured in slash pine (Pinus elliottii var. elliottii) trees of known genetic origin over a 1-year period. A strong broad-sense heritability of this trait was found. Seasonal variation followed a definite pattern, with the highest viscosities occurring in early spring and a gradual decline occurring in...

Inference of viscosity jump at 670 km depth and lower mantle viscosity structure from GIA observations

Science.gov (United States)

Nakada, Masao; Okuno, Jun'ichi; Irie, Yoshiya

2018-03-01

A viscosity model with an exponential profile described by temperature (T) and pressure (P) distributions and constant activation energy (E_{{{um}}}^{{*}} for the upper mantle and E_{{{lm}}}^* for the lower mantle) and volume (V_{{{um}}}^{{*}} and V_{{{lm}}}^*) is employed in inferring the viscosity structure of the Earth's mantle from observations of glacial isostatic adjustment (GIA). We first construct standard viscosity models with an average upper-mantle viscosity ({\\bar{η }_{{{um}}}}) of 2 × 1020 Pa s, a typical value for the oceanic upper-mantle viscosity, satisfying the observationally derived three GIA-related observables, GIA-induced rate of change of the degree-two zonal harmonic of the geopotential, {\\dot{J}_2}, and differential relative sea level (RSL) changes for the Last Glacial Maximum sea levels at Barbados and Bonaparte Gulf in Australia and for RSL changes at 6 kyr BP for Karumba and Halifax Bay in Australia. Standard viscosity models inferred from three GIA-related observables are characterized by a viscosity of ˜1023 Pa s in the deep mantle for an assumed viscosity at 670 km depth, ηlm(670), of (1 - 50) × 1021 Pa s. Postglacial RSL changes at Southport, Bermuda and Everglades in the intermediate region of the North American ice sheet, largely dependent on its gross melting history, have a crucial potential for inference of a viscosity jump at 670 km depth. The analyses of these RSL changes based on the viscosity models with {\\bar{η }_{{{um}}}} ≥ 2 × 1020 Pa s and lower-mantle viscosity structures for the standard models yield permissible {\\bar{η }_{{{um}}}} and ηlm (670) values, although there is a trade-off between the viscosity and ice history models. Our preferred {\\bar{η }_{{{um}}}} and ηlm (670) values are ˜(7 - 9) × 1020 and ˜1022 Pa s, respectively, and the {\\bar{η }_{{{um}}}} is higher than that for the typical value of oceanic upper mantle, which may reflect a moderate laterally heterogeneous upper

Determination of the density and the viscosities of biodiesel-diesel fuel blends

Energy Technology Data Exchange (ETDEWEB)

Alptekin, Ertan; Canakci, Mustafa [Department of Mechanical Education, Kocaeli University, 41380 Kocaeli (Turkey); Alternative Fuels R and D Center, Kocaeli University, 41040 Kocaeli (Turkey)

2008-12-15

In this study, commercially available two different diesel fuels were blended with the biodiesels produced from six different vegetable oils (sunflower, canola, soybean, cottonseed, corn oils and waste palm oil). The blends (B2, B5, B10, B20, B50 and B75) were prepared on a volume basis. The key fuel properties such as density and viscosities of the blends were measured by following ASTM test methods. Generalized equations for predicting the density and viscosities for the blends were given and a mixing equation, originally proposed by Arrhenius and described by Grunberg and Nissan, was used to predict the viscosities of the blends. For all blends, it was found that there is an excellent agreement between the measured and estimated values of the density and viscosities. According to the results, the density and viscosities of the blends increased with the increase of biodiesel concentration in the fuel blend. (author)

Macroscopic and microscopic structural integrity in magnetic colloids-cationic micellar solution: Rheology, SANS and magneto-optical study

Energy Technology Data Exchange (ETDEWEB)

Patel, Rajesh, E-mail: rjp@bhavuni.ed [Department of Physics, Bhavnagar University, Bhavnagar 364 022 (India); Upadhyay, R.V., E-mail: rvu.as@ecchanga.ac.i [Charotar Institute of Applied Sciences, Education Campus, Changa 388421, Anand, Gujarat (India); Aswal, V.K. [Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Joshi, J.V.; Goyal, P.S. [UGC- DAE Consortium for Scientific Research, Mumbai Centre, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

2011-03-15

A stable mixture of two colloid system composed of double surfactant coated aqueous nanomagnetic fluid and aqueous micellar solution of cationic micelles of cetyletrymethyl ammonium bromide (CTABr) is prepared as a function of nanomagnetic fluid concentration. This mixed system is analyzed using three techniques such as zero field and field induced viscosity measurements, Small Angle Neutron Scattering technique and magneto-optical birefringence measurements. In field induced viscosity measurement it is observed that even 20% magnetic fluid concentration in CTABr aqueous solution shows 75% increase in viscosity compared to pure magnetic fluid. This suggests that in presence of CTABr micelles, a novel magneto rheological effect for low concentration of magnetic fluid is observed. From SANS measurements it is observed that aggregation number and a/b ratio increases with magnetic fluid concentration and magnetic birefringence reveals non-superimpose behavior of normalized field induced retardation. Results of these experiments are compared and indicate zero fields and field induced structural integrity between magnetic particles and soft micelles. - Research Highlights: {yields} This study exhibits zero field and field induced structural integrity between soft micelles and magnetic nanoparticles. {yields} The techniques used are viscosity measurements, Small Angle Neutron Scattering technique and magneto-optical birefringence. {yields} Study is useful for magnetic hyperthermia via micelles, as soft actuators, as an artificial micro-muscles, micro-manipulators, etc.

A new model for the accurate calculation of natural gas viscosity

Directory of Open Access Journals (Sweden)

Xiaohong Yang

2017-03-01

Full Text Available Viscosity of natural gas is a basic and important parameter, of theoretical and practical significance in the domain of natural gas recovery, transmission and processing. In order to obtain the accurate viscosity data efficiently at a low cost, a new model and its corresponding functional relation are derived on the basis of the relationship among viscosity, temperature and density derived from the kinetic theory of gases. After the model parameters were optimized using a lot of experimental data, the diagram showing the variation of viscosity along with temperature and density is prepared, showing that: ① the gas viscosity increases with the increase of density as well as the increase of temperature in the low density region; ② the gas viscosity increases with the decrease of temperature in high density region. With this new model, the viscosity of 9 natural gas samples was calculated precisely. The average relative deviation between these calculated values and 1539 experimental data measured at 250–450 K and 0.10–140.0 MPa is less than 1.9%. Compared with the 793 experimental data with a measurement error less than 0.5%, the maximum relative deviation is less than 0.98%. It is concluded that this new model is more advantageous than the previous 8 models in terms of simplicity, accuracy, fast calculation, and direct applicability to the CO2 bearing gas samples.

Crystallization, Microstructure, and Viscosity Evolutions in Lithium Aluminosilicate Glass-Ceramics

Directory of Open Access Journals (Sweden)

Qiang Fu

2016-11-01

Full Text Available Lithium aluminosilicate glass-ceramics have found widespread commercial success in areas such as consumer products, telescope mirrors, fireplace windows, etc. However, there is still much to learn regarding the fundamental mechanisms of crystallization, especially related to the evolution of viscosity as a function of the crystallization (ceramming process. In this study, the impact of phase assemblage and microstructure on the viscosity was investigated using high temperature X-ray diffraction (HTXRD, beam bending viscometry (BBV, and transmission electron microscopy (TEM. Results from this study provide a first direct observation of viscosity evolution as a function of ceramming time and temperature. Sharp viscosity increases due to phase separation, nucleation and phase transformation are noticed through BBV measurement. A near-net shape ceramming can be achieved in TiO2-containing compositions by keeping the glass at a high viscosity (> 109 Pa.s throughout the whole thermal treatment.

Effect of Fluid Dynamic Viscosity on the Strength of Chalk

DEFF Research Database (Denmark)

Hedegaard, K.; Fabricius, Ida Lykke

The mechanical strength of high porosity and weakly cemented chalk is affected by the fluid in the pores. In this study, the effect of the dynamic viscosity of non-polar fluids has been measured on outcrop chalk from Sigerslev Quarry, Stevns, Denmark. The outcome is that the measured strength...... of the chalk decreases with increasing dynamic viscosity. The proposed qualitative explanation is that pressure difference supports and enhances the generation of microscopic shear and tensile failures....

Viscosity of saturated helium-3-helium-4 mixture below 200 mK

NARCIS (Netherlands)

Zeegers, J.C.H.; Waele, de A.T.A.M.; Gijsman, H.M.

1991-01-01

The shear viscosity of saturated3He-4He mixture has been measured at temperatures between 7 mK and 200 mK using a vibrating-wire viscometer and a calibrated pressure cell. The reliability of the vibrating-wire technique was tested by measuring the viscosity of pure4He. The results are internally

Temperature Dependence of the Viscosity of Isotropic Liquids

Science.gov (United States)

Jadzyn, J.; Czechowski, G.; Lech, T.

1999-04-01

Temperature dependence of the shear viscosity measured for isotropic liquids belonging to the three homologous series: 4-(trans-4'-n-alkylcyclohexyl) isothiocyanatobenzenes (Cn H2n+1 CyHx Ph NCS; nCHBT, n=0-12), n-alkylcyanobiphenyls (CnH2n+1 Ph Ph CN; nCB, n=2-12) and 1,n-alkanediols (HO(CH2)nOH; 1,nAD, n=2-10) were analysed with the use of Arrhenius equation and its two modifications: Vogel--Fulcher and proposed in this paper. The extrapolation of the isothermal viscosity of 1,n-alkanediols (n=2-10) to n=1 leads to an interesting conclusion concerning the expected viscosity of methanediol, HOCH2OH, the compound strongly unstable in a pure state.

Solute-solvent interactions in solutions of 2-hydroxy-5-chloro-3-nitroacetophenone isonicotinoylhydrazone in N, N-dimethylformamide at 298-313 K according to ultrasonic and viscometric data

Science.gov (United States)

Dikkar, A. B.; Pethe, G. B.; Aswar, A. S.

2015-12-01

Density (ρ), speed of sound ( u), and viscosity (η), measurements have been carried on 2-hydroxy- 5-chloro-3-nitroacetophenone isonicotinoylhydrazone (HCNAIH) in N, N-dimethylformamide at 298.15, 303.15, 308.15, and 313.15 K. Adiabatic compressibility (βs), intermolecular free length ( L f), acoustic impedance ( Z), internal pressure ( P int), the apparent molar volume ( V w), limiting apparent molar volume ( V w 0), partial molar expansibility (wE 0), apparent molar adiabatic compressibility ( K w), limiting apparent molar adiabatic compressibility ( K w 0), viscosity B coefficients of Jones-Dole equation have been calculated. The activation free energy (Δμ 2 0 *) for viscous flow in solution have been calculated from B coefficient and partial molar volume data. The calculated parameters are used to interpret the solute-solvent interactions and structure forming/breaking ability of solute in DMF.

Technological characteristics of meat - viscosity

OpenAIRE

DIBĎÁK, Tomáš

2012-01-01

This bachelor thesis is focused on the technological characteristics of meat, mainly viscosity of meat. At the beginning I dealt with construction of meat and various types of meat: beef, veal, pork, mutton, rabbit, poultry and venison. Then I described basic chemical composition of meat and it?s characteristic. In detail I dealt with viscosity of meat. Viscosity is the ability of meat to bind water both own and added. I mentioned influences, which effects viscosity and I presented the possib...

Prediction of the viscosity of lubricating oil blends at any temperature

Energy Technology Data Exchange (ETDEWEB)

Diaz, R.M.; Bernardo, M.I.; Fernandez, A.M.; Folgueras, M.B. [University of Oviedo, Oveido (Spain). Dept. of Energy

1996-04-01

This paper discusses a method of predicting the viscosity of multicomponent base lubricating oil mixtures based on Andrade`s equation. The kinematic viscosity of three types of base lubricating oils and their binary and ternary mixtures were measured at different temperatures and the parameters of Andrade`s equation were calculated. The results obtained indicate that the Andrade parameters vary linearly with the mixture composition. From these linear equations, generalized mixing equations are derived which confirm the experimental results. By application of the mixing equations, a simple method is obtained for prediction of the viscosity of oil blends at any temperature from viscosity-temperature data of the oil components. The calculated viscosities gave an average absolute deviation of 10% over the temperature range 20-100{degree}C. 8 refs., 3 figs., 4 tabs.

Fission hindrance and nuclear viscosity

Indian Academy of Sciences (India)

is in exact conformity with all the previous measurements [7,10–13]. The CASCADE calculations (solid lines in figure 1) used in this first level of analysis do not include any viscosity or temperature-dependent nuclear level density parameter a. The γ and particle decay are calculated using the standard prescriptions as ...

Predicting the glass transition temperature and viscosity of secondary organic material using molecular composition

Directory of Open Access Journals (Sweden)

W.-S. W. DeRieux

2018-05-01

Full Text Available Secondary organic aerosol (SOA accounts for a large fraction of submicron particles in the atmosphere. SOA can occur in amorphous solid or semi-solid phase states depending on chemical composition, relative humidity (RH, and temperature. The phase transition between amorphous solid and semi-solid states occurs at the glass transition temperature (Tg. We have recently developed a method to estimate Tg of pure compounds containing carbon, hydrogen, and oxygen atoms (CHO compounds with molar mass less than 450 g mol−1 based on their molar mass and atomic O : C ratio. In this study, we refine and extend this method for CH and CHO compounds with molar mass up to ∼ 1100 g mol−1 using the number of carbon, hydrogen, and oxygen atoms. We predict viscosity from the Tg-scaled Arrhenius plot of fragility (viscosity vs. Tg∕T as a function of the fragility parameter D. We compiled D values of organic compounds from the literature and found that D approaches a lower limit of ∼ 10 (±1.7 as the molar mass increases. We estimated the viscosity of α-pinene and isoprene SOA as a function of RH by accounting for the hygroscopic growth of SOA and applying the Gordon–Taylor mixing rule, reproducing previously published experimental measurements very well. Sensitivity studies were conducted to evaluate impacts of Tg, D, the hygroscopicity parameter (κ, and the Gordon–Taylor constant on viscosity predictions. The viscosity of toluene SOA was predicted using the elemental composition obtained by high-resolution mass spectrometry (HRMS, resulting in a good agreement with the measured viscosity. We also estimated the viscosity of biomass burning particles using the chemical composition measured by HRMS with two different ionization techniques: electrospray ionization (ESI and atmospheric pressure photoionization (APPI. Due to differences in detected organic compounds and signal intensity, predicted viscosities at low RH based on ESI and

An ultrasonic instrument for measuring density and viscosity of tank waste

International Nuclear Information System (INIS)

Sheen, S.H.; Chien, H.T.; Raptis, A.C.

1997-01-01

An estimated 381,000 m 3 /1.1 x 10 9 Ci of radioactive waste are stored in high-level waste tanks at the Hanford Savannah River, Idaho Nuclear Engineering and Environmental Laboratory, and West Valley facilities. This nuclear waste has created one of the most complex waste management and cleanup problems that face the United States. Release of radioactive materials into the environment from underground waste tanks requires immediate cleanup and waste retrieval. Hydraulic mobilization with mixer pumps will be used to retrieve waste slurries and salt cakes from storage tanks. To ensure that transport lines in the hydraulic system will not become plugged, the physical properties of the slurries must be monitored. Characterization of a slurry flow requires reliable measurement of slurry density, mass flow, viscosity, and volume percent of solids. Such measurements are preferably made with on-line nonintrusive sensors that can provide continuous real-time monitoring. With the support of the U.S. Department of Energy (DOE) Office of Environmental Management (EM-50), Argonne National Laboratory (ANL) is developing an ultrasonic instrument for in-line monitoring of physical properties of radioactive tank waste

Viscosity of komatiite liquid at high pressure and temperature

Science.gov (United States)

O Dwyer, L.; Lesher, C. E.; Wang, Y.

2006-12-01

The viscosities of komatiite liquids at high pressures and temperatures are being investigated by the in-situ falling sphere technique, using the T-25 multianvil apparatus at the GSECARS 13 ID-D beamline at the Advanced Photon Source, ANL. The refractory and fluid nature of komatiite and other ultramafic liquids relevant to the Earth's deep interior, presents unique challenges for this approach. To reach superliquidus temperatures we use a double reservoir configuration, where marker spheres are placed at the top of both a main melt reservoir and an overlying reservoir containing a more refractory composition. Using this approach, we have successfully measured the viscosity of a komatiite from Gorgona Island (GOR-94-29; MgO - 17.8 wt.%; NBO/T = 1.6) up to 6 GPa and 1900 K. Under isothermal conditions, viscosity increases with pressure, consistent with the depolymerized nature of the komatiite. At 1900 K, viscosity increases from 1.5 (+- 0.3) Pa s at 3.5 GPa to 3.4 (+- 0.3) Pa s at 6 GPa, corresponding to an activation volume of 2.2 cm3/mol. At high pressures, the viscosities of Gorgona Island komatiite melt are an order of magnitude higher than those measured by Liebske et al. (2005, EPSL, v. 240) for peridotite melt (MgO 37.1 wt.%; NBO/T = 2.5), and similar in magnitude to molten diopside (NBO/T = 2) (Reid et al. 2003, PEPI, v. 139). The positive pressure dependence is consistent with the reduction in interatomic space diminishing the free volume of the liquid as it is compressed. Above 6 GPa the free volume reduction may become less important with the production of high-coordinated network formers, as attributed to the reversal of the pressure dependence of viscosity for peridotite melt at ~8.5 GPa and diopside melt at ~10 GPa. Experiments at higher pressures are underway to determine if a similar viscosity maximum occurs for komatiite melt and whether its pressure is greater than 10 GPa, as suggested by the data for peridotite and diopside melts.

Characterization of oscillator circuits for monitoring the density-viscosity of liquids by means of piezoelectric MEMS microresonators

Science.gov (United States)

Toledo, J.; Ruiz-Díez, V.; Pfusterschmied, G.; Schmid, U.; Sánchez-Rojas, J. L.

2017-06-01

Real-time monitoring of the physical properties of liquids, such as lubricants, is a very important issue for the automotive industry. For example, contamination of lubricating oil by diesel soot has a significant impact on engine wear. Resonant microstructures are regarded as a precise and compact solution for tracking the viscosity and density of lubricant oils. In this work, we report a piezoelectric resonator, designed to resonate with the 4th order out-of-plane modal vibration, 15-mode, and the interface circuit and calibration process for the monitoring of oil dilution with diesel fuel. In order to determine the resonance parameters of interest, i.e. resonant frequency and quality factor, an interface circuit was implemented and included within a closed-loop scheme. Two types of oscillator circuits were tested, a Phase-Locked Loop based on instrumentation, and a more compact version based on discrete electronics, showing similar resolution. Another objective of this work is the assessment of a calibration method for piezoelectric MEMS resonators in simultaneous density and viscosity sensing. An advanced calibration model, based on a Taylor series of the hydrodynamic function, was established as a suitable method for determining the density and viscosity with the lowest calibration error. Our results demonstrate the performance of the resonator in different oil samples with viscosities up to 90 mPa•s. At the highest value, the quality factor measured at 25°C was around 22. The best resolution obtained was 2.4•10-6 g/ml for the density and 2.7•10-3 mPa•s for the viscosity, in pure lubricant oil SAE 0W30 at 90°C. Furthermore, the estimated density and viscosity values with the MEMS resonator were compared to those obtained with a commercial density-viscosity meter, reaching a mean calibration error in the best scenario of around 0.08% for the density and 3.8% for the viscosity.

Design of a High Viscosity Couette Flow Facility for Patterned Surface Drag Measurements

Science.gov (United States)

Johnson, Tyler; Lang, Amy

2009-11-01

Direct drag measurements can be difficult to obtain with low viscosity fluids such as air or water. In this facility, mineral oil is used as the working fluid to increase the shear stress across the surface of experimental models. A mounted conveyor creates a flow within a plexiglass tank. The experimental model of a flat or patterned surface is suspended above a moving belt. Within the gap between the model and moving belt a Couette flow with a linear velocity profile is created. PIV measurements are used to determine the exact velocities and the Reynolds numbers for each experiment. The model is suspended by bars that connect to the pillow block housing of each bearing. Drag is measured by a force gauge connected to linear roller bearings that slide along steel rods. The patterned surfaces, initially consisting of 2-D cavities, are embedded in a plexiglass plate so as to keep the total surface area constant for each experiment. First, the drag across a flat plate is measured and compared to theoretical values for laminar Couette flow. The drag for patterned surfaces is then measured and compared to a flat plate.

Solute-solvent interactions in 2,4-dihydroxyacetophenone isonicotinoylhydrazone solutions in N, N-dimethylformamide and dimethyl sulfoxide at 298-313 K on ultrasonic and viscometric data

Science.gov (United States)

Dikkar, A. B.; Pethe, G. B.; Aswar, A. S.

2016-02-01

The speed of sound ( u), density (ρ), and viscosity (η) of 2,4-dihydroxyacetophenone isonicotinoylhydrazone (DHAIH) have been measured in N, N-dimethyl formamide and dimethyl sulfoxide at equidistance temperatures 298.15, 303.15, 308.15, and 313.15 K. These data were used to calculate some important ultrasonic and thermodynamic parameters such as apparent molar volume ( V ϕ s st ), apparent molar compressibility ( K ϕ), partial molar volume ( V ϕ 0 ) and partial molar compressibility ( K ϕ 0 ), were estimated by using the values of ( V ϕ 0 ) and ( K ϕ), at infinite dilution. Partial molar expansion at infinite dilution, (ϕ E 0 ) has also been calculated from temperature dependence of partial molar volume V ϕ 0 . The viscosity data have been analyzed using the Jones-Dole equation, and the viscosity, B coefficients are calculated. The activation free energy has been calculated from B coefficients and partial molar volume data. The results have been discussed in the term of solute-solvent interaction occurring in solutions and it was found that DHAIH acts as a structure maker in present systems.

Relationship between viscosity of the ankle joint complex and functional ankle instability for inversion ankle sprain patients.

Science.gov (United States)

Lin, Che-Yu; Kang, Jiunn-Horng; Wang, Chung-Li; Shau, Yio-Wha

2015-03-01

Measurement of viscosity of the ankle joint complex is a novel method to assess mechanical ankle instability. In order to further investigate the clinical significance of the method, this study intended to investigate the relationship between ankle viscosity and severity of functional ankle instability. Cross-sectional study. 15 participants with unilateral inversion ankle sprain and 15 controls were recruited. Their ankles were further classified into stable and unstable ankles. Ankle viscosity was measured by an instrumental anterior drawer test. Severity of functional ankle instability was measured by the Cumberland Ankle Instability Tool. Unstable ankles were compared with stable ankles. Injured ankles were compared with uninjured ankles of both groups. The spearman's rank correlation coefficient was applied to determine the relationship between ankle viscosity and severity of functional ankle instability in unstable ankles. There was a moderate relationship between ankle viscosity and severity of functional ankle instability (r=-0.64, pankles exhibited significantly lower viscosity (pankle instability (pankles. Injured ankles exhibited significantly lower viscosity and more severe functional ankle instability than uninjured ankles (pankle viscosity and severity of functional ankle instability. This finding suggested that, severity of functional ankle instability may be partially attributed to mechanical insufficiencies such as the degenerative changes in ankle viscosity following the inversion ankle sprain. In clinical application, measurement of ankle viscosity could be a useful tool to evaluate severity of chronic ankle instability. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Determination of liquid viscosity at high pressure by DLS

International Nuclear Information System (INIS)

Fukui, K; Asakuma, Y; Maeda, K

2010-01-01

The movement of particles with a size smaller than few microns is governed by random Brownian motion. This motion causes the fluid to flow around the particles. The force acting upon Brownian particles as well as their velocities are measured by using the dynamic light scattering (DLS) technique. It provides the relationship between fluid shear stress and shear rate over the Brownian particle and determines the viscosity properties of the fluid. In this study, we propose a new rheometer which is widely applicable to fluid viscosity measurements at both normal and high pressure levels for Newtonian and non- Newtonian fluids.

Experimental determination of viscosity of water based magnetite nanofluid for application in heating and cooling systems

International Nuclear Information System (INIS)

Toghraie, Davood; Alempour, Seyed Mohammadbagher; Afrand, Masoud

2016-01-01

In this paper, experimental determination of dynamic viscosity of water based magnetite nanofluid (Fe 3 O 4 /water) was performed. The viscosity was measured in the temperature range of 20–55 °C for various samples with solid volume fractions of 0.1%, 0.2%, 0.4%, 1%, 2% and 3%. The results showed that the viscosity considerably decreases with increasing temperature. Moreover, the viscosity enhances with an increase in the solid volume fraction, remarkably. The calculated viscosity ratios showed that the maximum viscosity enhancement was 129.7%. Using experimental data, a new correlation has been proposed to predict the viscosity of magnetite nanofluid (Fe 3 O 4 /water). A comparison between the experimental results and the correlation outputs showed that the proposed model has a suitable accuracy. - Highlights: • Preparing Magnetite nanofluids with solid volume fractions up to 3%. • Measuring viscosity in temperature range of 20–55 °C using Brookfield Viscometer. • Maximum viscosity enhancement occurred at volume fraction of 3% and was 129.7%. • Proposing new correlation to predict the viscosity of Fe3O4/water nanofluid.

Measuring and overcoming limits of the Saffman-Delbrück model for soap film viscosities.

Science.gov (United States)

Vivek, Skanda; Weeks, Eric R

2015-01-01

We observe tracer particles diffusing in soap films to measure the two-dimensional (2D) viscous properties of the films. Saffman-Delbrück type models relate the single-particle diffusivity to parameters of the film (such as thickness h) for thin films, but the relation breaks down for thicker films. Notably, the diffusivity is faster than expected for thicker films, with the crossover at h/d = 5.2 ± 0.9 using the tracer particle diameter d. This indicates a crossover from purely 2D diffusion to diffusion that is more three-dimensional. We demonstrate that measuring the correlations of particle pairs as a function of their separation overcomes the limitations of the Saffman-Delbrück model and allows one to measure the viscosity of a soap film for any thickness.

Spectroscopic studies on di-pophyrin rotor as micro-viscosity sensor

Science.gov (United States)

Doan, H.; Raut, S.; Kimbal, J.; Gryczynski, Z.; Dzyuba, S.; Balaz, M.

2015-03-01

In typical biological systems the fluid compartment makes up more than 70% percent of the system weight. A variety of mass and signal transportation as well as intermolecular interactions are often governed by viscosity. It is important to be able to measure/estimate viscosity and detect the changes in viscosity upon various stimulations. Understanding the influence of changes in viscosity is crucial and development of the molecular systems that sensitive to micro-viscosity is a goal of many researches. Molecular rotors have been considered the potential target since they present enhanced sensitivity to local viscosity that can strongly restrict molecular rotation. To understand the mechanics of rotor interaction with the environment we have been studied conjugated pophyrin-dimer rotor (DP) that emit in the near IR. Our goal is to investigate the photo physical properties such as absorption, transition moment orientation, emission and excitation, polarization anisotropy and fluorescence lifetime in various mediums of different viscosities from ethanol to poly vinyl alcohol (PVA) matrices. The results imply the influences of the medium's viscosity on the two distinct confirmations: planar and twisted conformations of DP. Linear dichroism from polarized absorption in PVA matrices shows various orientations of transition moments. Excitation anisotropy shows similar transition splitting between two conformations. Time resolved intensity decay at two different observations confirms the two different emission states and furthermore the communication between the two states in the form of energy transfer upon excitation.

Viscosity calculated in simulations of strongly coupled dusty plasmas with gas friction

International Nuclear Information System (INIS)

Feng Yan; Goree, J.; Liu Bin

2011-01-01

A two-dimensional strongly coupled dusty plasma is modeled using Langevin and frictionless molecular dynamical simulations. The static viscosity η and the wave-number-dependent viscosity η(k) are calculated from the microscopic shear in the random motion of particles. A recently developed method of calculating the wave-number-dependent viscosity η(k) is validated by comparing the results of η(k) from the two simulations. It is also verified that the Green-Kubo relation can still yield an accurate measure of the static viscosity η in the presence of a modest level of friction as in dusty plasma experiments.

The adhesive strength and initial viscosity of denture adhesives.

Science.gov (United States)

Han, Jian-Min; Hong, Guang; Dilinuer, Maimaitishawuti; Lin, Hong; Zheng, Gang; Wang, Xin-Zhi; Sasaki, Keiichi

2014-11-01

To examine the initial viscosity and adhesive strength of modern denture adhesives in vitro. Three cream-type denture adhesives (Poligrip S, Corect Cream, Liodent Cream; PGS, CRC, LDC) and three powder-type denture adhesives (Poligrip Powder, New Faston, Zanfton; PGP, FSN, ZFN) were used in this study. The initial viscosity was measured using a controlled-stress rheometer. The adhesive strength was measured according to ISO-10873 recommended procedures. All data were analyzed independently by one-way analysis of variance combined with a Student-Newman-Keuls multiple comparison test at a 5% level of significance. The initial viscosity of all the cream-type denture adhesives was lower than the powder-type adhesives. Before immersion in water, all the powder-type adhesives exhibited higher adhesive strength than the cream-type adhesives. However, the adhesive strength of cream-type denture adhesives increased significantly and exceeded the powder-type denture adhesives after immersion in water. For powder-type adhesives, the adhesive strength significantly decreased after immersion in water for 60 min, while the adhesive strength of the cream-type adhesives significantly decreased after immersion in water for 180 min. Cream-type denture adhesives have lower initial viscosity and higher adhesive strength than powder type adhesives, which may offer better manipulation properties and greater efficacy during application.

The magnetoviscous effect of micellar solutions doped with water based ferrofluids

Energy Technology Data Exchange (ETDEWEB)

Arantes, Fabiana R., E-mail: farantes@if.usp.br [Institute of Physics, University of Sao Paulo (Brazil); Institute of Fluid Mechanics, Technische Universität Dresden (Germany); Odenbach, Stefan, E-mail: stefan.odenbach@tu-dresden.de [Institute of Fluid Mechanics, Technische Universität Dresden (Germany)

2015-09-15

This work presents a magnetorheological study of micellar solutions of potassium laurate and water doped with magnetite nanoparticles, accompanied by auxiliary dynamic light scattering measurements. An increase in the viscosity of the samples under applied field was observed and, furthermore, a considerable magnetoviscous effect was revealed even at magnetic particles' concentrations as low as 0.005–0.01 vol%. This indicates that the rheological behavior of the micelles is changed by the interaction of the magnetic particles with the applied field, leading to different microscopic arrangements in the micellar solutions. - Highlights: • We study the magnetorheological behavior of micellar solutions doped with ferrofluids. • We observe an increase in the viscosity of the samples under an applied field. • We find a large magnetoviscous effect even at low magnetic particles' concentration. • Interaction of particles with the field changes the micelles' rheological behavior.

Influence of solution properties in the laser forward transfer of liquids

Energy Technology Data Exchange (ETDEWEB)

Dinca, V. [Universitat de Barcelona, Departament de Fisica Aplicada i Optica, Marti i Franques 1, E-08028 Barcelona (Spain); National Institute for Lasers, Plasma and Radiation Physics Atomistilor No.409, P O. Box MG 16, 077125 Bucharest (Romania); Patrascioiu, A.; Fernandez-Pradas, J.M.; Morenza, J.L. [Universitat de Barcelona, Departament de Fisica Aplicada i Optica, Marti i Franques 1, E-08028 Barcelona (Spain); Serra, P., E-mail: pserra@ub.edu [Universitat de Barcelona, Departament de Fisica Aplicada i Optica, Marti i Franques 1, E-08028 Barcelona (Spain)

2012-09-15

Highlights: Black-Right-Pointing-Pointer Influence of viscosity on the LIFT dynamics in the case of a Newtonian liquid. Black-Right-Pointing-Pointer A very broad range of viscosities (1.9-850 mPa s) can be LIFT printed. Black-Right-Pointing-Pointer Printing uniformity correlates well with the stability of the ejection process. - Abstract: The influence of the viscosity of the printed solution on the laser-induced forward transfer (LIFT) of liquids is investigated. A set of water and glycerol mixtures with different glycerol content are prepared with the aim of having a collection of solutions covering a wide range of viscosities, from 1.9 to 850 mPa s. Arrays of micrometric droplets of those solutions are spotted through LIFT and characterized by means of optical microscopy, revealing that for all the analyzed solutions there always exists a range of laser fluences leading to the formation of regular circular droplets, with that range increasing and widening with viscosity. The dynamics of liquid ejection is investigated through time-resolved imaging with the aim of understanding the role of viscosity in the process, and its influence on the morphology of the deposited droplets. The acquired stop-action movies reveal that liquid transfer proceeds mainly through jetting, with the exception of LIFT at low viscosities and high laser fluences, in which bursting develops. From this study it is concluded that viscosity plays an important role in the stabilization of liquid ejection and transport, which contributes to the uniformity of the deposited droplets.

Calculated viscosity-distance dependence for some actively flowing lavas

International Nuclear Information System (INIS)

Pieri, D.

1987-01-01

The importance of viscosity as a gauge of the various energy and momentum dissipation regimes of lava flows has been realized for a long time. Nevertheless, despite its central role in lava dynamics and kinematics, it remains among the most difficult of flow physical properties to measure in situ during an eruption. Attempts at reconstructing the actual emplacement viscosities of lava flows from their solidified topographic form are difficult. Where data are available on the position of an advancing flow front as a function of time, it is possible to calculate the effective viscosity of the front as a function of distance from the vent, under the assumptions of a steady state regime. As an application and test of an equation given, relevant parameters from five recent flows on Mauna Loa and Kilauea were utilized to infer the dynamic structure of their aggregate flow front viscosity as they advanced, up to cessation. The observed form of the viscosity-distance relation for the five active Hawaiian flows examined appears to be exponential, with a rapid increase just before the flows stopped as one would expect

Validation of the Eddy Viscosity and Lange Wake Models using Measured Wake Flow Characteristics Behind a Large Wind Turbine Rotor

Energy Technology Data Exchange (ETDEWEB)

Jeon, Sang Hyeon; Kim, Bum Suk; Huh, Jong Chul [Jeju National Univ., Jeju (Korea, Republic of); Go, Young Jun [Hanjin Ind, Co., Ltd., Yangsan (Korea, Republic of)

2016-01-15

The wake effects behind wind turbines were investigated by using data from a Met Mast tower and the SCADA (Supervisory Control and Data Acquisition) system for a wind turbine. The results of the wake investigations and predicted values for the velocity deficit based on the eddy viscosity model were compared with the turbulence intensity from the Lange model. As a result, the velocity deficit and turbulence intensity of the wake increased as the free stream wind speed decreased. In addition, the magnitude of the velocity deficit for the center of the wake using the eddy viscosity model was overestimated while the turbulence intensity from the Lange model showed similarities with measured values.

Using Of Viscosity Property For Identification Of Irradiated Black Pepper And Cumin

International Nuclear Information System (INIS)

ALI, H.G.M.

2009-01-01

In the present investigation, the viscosity measurement was used for detecting irradiated black pepper and cumin during storage period. All samples under investigation were packed in polyethylene bags then irradiated at 3, 5, 7 and 10 kGy and stored for 12 months at room temperature then viscosity were measured under extremely alkaline condition (ph 13.8). The results indicated that irradiation treatment caused significant decrease in apparent viscosity values, where it decreased from 67.3 in control sample to 49.7, 42.3, 38.7 and 32.7 mpa.s in black pepper, while the viscosity of cumin was decreased from 74 mpa.s for control to 64.9, 41.7, 25.3 and 11.3 mpa.s for samples. The viscosity of black pepper and cumin were decreased significantly with increasing the radiation dose and during storage period. It was decreased from 67.3 for control to 67.0, 47.7, 32.3 and 17.7 mpa.s after 3, 6, 9 and 12 months, respectively, in black pepper while the viscosity of cumin samples was decreased significantly from 74 for control to 50.3, 17.1, 9.5 and 7.2 mpa.s after the same months. The data also showed that the moisture and carbohydrate contents were decreased by increasing the radiation dose. It could be concluded that the viscosity parameter can be used to identify of black pepper and cumin samples after irradiation and during 12 months of storage at ambient temperature.

Viscosity of SiO2-"FeO"-Al2O3 System in Equilibrium with Metallic Fe

Science.gov (United States)

Chen, Mao; Raghunath, Sreekanth; Zhao, Baojun

2013-08-01

The present study delivered the measurements of viscosities in SiO2-"FeO"-Al2O3 system in equilibrium with metallic Fe. The rotational spindle technique was used in the measurements at the temperature range of 1473 K to 1773 K (1200 °C to 1500 °C). Molybdenum crucibles and spindles were employed in all measurements. The Fe saturation condition was maintained by an iron plate placed at the bottom of the crucible. The equilibrium compositions of the slags were measured by EPMA after the viscosity measurements. The effect of up to 20 mol. pct Al2O3 on the viscosity of the SiO2-"FeO" slag was investigated. The "charge compensation effect" of the Al2O3 and FeO association has been discussed. The modified quasi-chemical viscosity model has been optimized in the SiO2-"FeO"-Al2O3 system in equilibrium with metallic Fe to describe the viscosity measurements of the present study.

Temperature and particle-size dependent viscosity data for water-based nanofluids - Hysteresis phenomenon

International Nuclear Information System (INIS)

Nguyen, C.T.; Desgranges, F.; Roy, G.; Galanis, N.; Mare, T.; Boucher, S.; Angue Mintsa, H.

2007-01-01

In the present paper, we have investigated experimentally the influence of both the temperature and the particle size on the dynamic viscosities of two particular water-based nanofluids, namely water-Al 2 O 3 and water-CuO mixtures. The measurement of nanofluid dynamic viscosities was accomplished using a 'piston-type' calibrated viscometer based on the Couette flow inside a cylindrical measurement chamber. Data were collected for temperatures ranging from ambient to 75 deg. C, for water-Al 2 O 3 mixtures with two different particle diameters, 36 nm and 47 nm, as well as for water-CuO nanofluid with 29 nm particle size. The results show that for particle volume fractions lower than 4%, viscosities corresponding to 36 nm and 47 nm particle-size alumina-water nanofluids are approximately identical. For higher particle fractions, viscosities of 47 nm particle-size are clearly higher than those of 36 nm size. Viscosities corresponding to water-oxide copper are the highest among the nanofluids tested. The temperature effect has been investigated thoroughly. A more complete viscosity data base is presented for the three nanofluids considered, with several experimental correlations proposed for low particle volume fractions. It has been found that the application of Einstein's formula and those derived from the linear fluid theory seems not to be appropriate for nanofluids. The hysteresis phenomenon on viscosity measurement, which is believed to be the first observed for nanofluids, has raised serious concerns regarding the use of nanofluids for heat transfer enhancement purposes

Influence of complexing on physicochemical properties of polymer-salt solutions

International Nuclear Information System (INIS)

Ostroushko, A.A.; Yushkova, S.M.; Koridze, N.V.; Skobkoreva, N.V.; Zhuravleva, L.I.; Palitskaya, T.A.; Antropova, S.V.; Ostroushko, I.P.; AN SSSR, Moscow

1993-01-01

Using the methods of spectrophotometry, viscosimetry, conductometry the influence of salt-polymer complexing processes on physicochemical prperties of aqueous solutions of yttrium, barium, copper nitrates and formates with polyvinyl alcohol was studied. Change of dynamic viscosity, specific electric conductivity of solutions in the process of complexing was shown. Thermal effects of salt-polymer interaction were measured. It is shown that decrease of transition temperature of polymer to plastic state in films, temperature and effective activation energy of salt decomposition is also connected with complexing. Effective values of surface tension on the boundary with air are measured. Coefficients of cation diffusion in polymer-salt solutions are estimated

Steady flow on to a conveyor belt - Causal viscosity and shear shocks

Science.gov (United States)

Syer, D.; Narayan, Ramesh

1993-01-01

Some hydrodynamical consequences of the adoption of a causal theory of viscosity are explored. Causality is introduced into the theory by letting the coefficient of viscosity go to zero as the flow velocity approaches a designated propagation speed for viscous signals. Consideration is given to a model of viscosity which has a finite propagation speed of shear information, and it is shown that it produces two kinds of shear shock. A 'pure shear shock' corresponds to a transition from a superviscous to a subviscous state with no discontinuity in the velocity. A 'mixed shear shock' has a shear transition occurring at the same location as a normal adiabatic or radiative shock. A generalized version of the Rankine-Hugoniot conditions for mixed shear shocks is derived, and self-consistent numerical solutions to a model 2D problem in which an axisymmetric radially infalling stream encounters a spinning star are presented.

Effect of Polyvinyl Siloxane Viscosity on Accuracy of Dental Implant Impressions

Directory of Open Access Journals (Sweden)

Ahmad Ghahremanloo

2017-02-01

Full Text Available Objectives: The aim of this study was to compare the accuracy of dental implant impressions obtained by a combination of different impression techniques and viscosities of polyvinyl siloxane (PVS.Materials and Methods: Four parallel fixtures were placed between mental foramina in a master model of lower dental arch. Three different viscosities (putty/light body, medium body/light body, and monophase: heavy body and direct and indirect techniques (six groups were used, and seven impressions were obtained from each group (n=42. To measure the accuracy of impressions, drift, horizontal, and vertical angles of the implants, as well as the hex rotation of the implants in casts were evaluated using a digitizer device (1μm accuracy, in comparison with master arch. Data were analyzed using five-factor two-way ANOVA and Tukey’s post-hoc test.Results: The accuracy of impressions was assessed and the results showed that direct technique was not significantly different from indirect technique (P>0.05. Also, there were no significant differences between the mentioned viscosities except for the horizontal angle (P=0.006.Conclusions: Viscosity of impression materials is of high significance for the accuracy of dental impressions.Keywords: Dental Materials; Dental Implants; Dental Impression Technique; Viscosity; Vinyl Polysiloxane; Dimensional Measurement Accuracy

glutamic acid from high-viscosity fermentation broth

African Journals Online (AJOL)

Measurement of IR spectrum was performed using an IR spectrophotometer with ... Results: The results showed that the γ-PGA yield was 35 g/L. The viscosity of ... of Pharmaceutical Research is indexed by Science Citation Index (SciSearch), ...

From Suitable Weak Solutions to Entropy Viscosity

KAUST Repository

Guermond, Jean-Luc; Pasquetti, Richard; Popov, Bojan

2010-01-01

This paper focuses on the notion of suitable weak solutions for the three-dimensional incompressible Navier-Stokes equations and discusses the relevance of this notion to Computational Fluid Dynamics. The purpose of the paper is twofold (i

On the mesoscopic origins of high viscosities in some polyelectrolyte-surfactant mixtures

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, Ingo, E-mail: ingo.hoffmann@tu-berlin.de [Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 124, Sekr. TC 7, D-10623 Berlin (Germany); Institut Max von Laue-Paul Langevin (ILL), F-38042 Grenoble Cedex 9 (France); Farago, Bela; Schweins, Ralf; Falus, Peter; Sharp, Melissa [Institut Max von Laue-Paul Langevin (ILL), F-38042 Grenoble Cedex 9 (France); Prévost, Sylvain [Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 124, Sekr. TC 7, D-10623 Berlin (Germany); Helmholtz-Zentrum Berlin, D-14109 Berlin (Germany); Gradzielski, Michael, E-mail: michael.gradzielski@tu-berlin.de [Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 124, Sekr. TC 7, D-10623 Berlin (Germany)

2015-08-21

Oppositely charged polyelectrolyte (PE) surfactant mixtures allow the control of rheological parameters of a solution even at fairly low concentrations. For example, addition of 0.3 wt. % of anionic surfactant to a 1 wt. % solution of the polycation JR 400 increases the viscosity by 4 orders of magnitude. Recently, we could show that this increase is related to the formation of mixed, rod-like PE/surfactant aggregates which interconnect several polyelectrolyte chains [Hoffmann et al., Europhys. Lett. 104, 28001 (2013)]. In this paper, we refine our structural model of the aggregates to obtain a more consistent picture of their internal structure for different anionic surfactants. Combining small angle neutron scattering (SANS) and neutron spin-echo (NSE) allows us to determine the size of the aggregates. By comparing different contrasts, the internal structure of the aggregates can be elucidated and it is seen that the PE in the aggregates retains a relatively high freedom of movement. We proceeded to investigate the influence of the surfactant concentration and the surfactant type on structure and dynamics of the mixed aggregates. It is seen that the structural parameters of the aggregates depend very little on the surfactant concentration and headgroup. However, it is crucial to incorporate a sufficient amount of PE in the aggregates to increase the viscosity of the aggregates. By comparing viscous samples at 1 wt. % PE concentration with samples at a PE concentration of 0.3 wt. %, where no significant increase in viscosity is observed, we find that similar aggregates are formed already at this lower PE concentrations. However, the amount of PE incorporated in them is insufficient to interconnect several PE chains and therefore, they do not increase viscosity. So, our detailed investigation combining contrast variation SANS and NSE does not only allow to explain the viscosity behavior but also to deduced detailed information regarding the structures and

Free convective boundary layers in variable-viscosity fluids by the method of local nonsimilarity: application to plumes in the earth's mantle

International Nuclear Information System (INIS)

Quareni, F.; Yuen, D.A.; Eby, H.E.

1983-01-01

The effects due to departures from local similarity in steady-state boundary layers ascending through a fluid with strongly variable viscosity are examined with the local-nonsimilarity method. Both the absolute temperature and the hydrostatic pressure appear in the argument of an exponential in the viscosity function. The fluid-dynamical system studied here is that which characterizes plume structures in the Earth's mantle. By means of an iterative approach, two successive nonlinear boundary value problems are solved simultaneously and the errors incurred in the locally similar solutions are then assessed from a comparison between the first (locally similar) and the second level of a system of truncated equations. Three different sources of nonsimilarity have been considered: 1) localized radiogenic hearting within the plume, 2) ambient thermal stratification, 3) pressure dependence of mantle rheology. Of particular interest is an appraisal of the degree of accuracy of the locally similar solutions as a function of viscosity contrast within the boundary layer. For the range of viscosity contrast examined, up to 10 8 , the velocity and temperature fields between the first- and second-level solutions differ at most by 20 to 30%, for the rheological parameter values relevant to the Earth's mantle

Estimation of viscosity based on transverse momentum correlations

Science.gov (United States)

Sharma, Monika

2010-02-01

The heavy ion program at RHIC created a paradigm shift in the exploration of strongly interacting hot and dense matter. An important milestone achieved is the discovery of the formation of strongly interacting matter which seemingly flows like a perfect liquid at temperatures on the scale of T ˜ 2 x10^12 K [1]. As a next step, we consider measurements of transport coefficients such as kinematic, shear or bulk viscosity? Many calculations based on event anisotropy measurements indicate that the shear viscosity to the entropy density ratio (η/s) of the fluid formed at RHIC is significantly below that of all known fluids including the superfluid ^4He [2]. Precise determination of η/s ratio is currently a subject of extensive study. We present an alternative technique for the determination of medium viscosity proposed by Gavin and Aziz [3]. Preliminary results of measurements of the evolution of the transverse momentum correlation function with collision centrality of Au + Au interactions at √sNN = 200 GeV will be shown. We present results on differential version of the correlation measure and describe its use for the experimental determination of η/s.[4pt] [1] J. Adams et al., [STAR Collaboration], Nucl. Phys. A 757 (2005) 102.[0pt] [2] R. A. Lacey et al., Phys. Rev. Lett. 98 (2007) 092301.[0pt] [3] S. Gavin and M. Abdel-Aziz, Phys. Rev. Lett. 97 (2006) 162302. )

Correlation of shear and dielectric ion viscosity of dental resins - Influence of composition, temperature and filler content.

Science.gov (United States)

Steinhaus, Johannes; Hausnerova, Berenika; Haenel, Thomas; Selig, Daniela; Duvenbeck, Fabian; Moeginger, Bernhard

2016-07-01

Shear viscosity and ion viscosity of uncured visible light-curing (VLC) resins and resin based composites (RBC) are correlated with respect to the resin composition, temperature and filler content to check where Dielectric Analysis (DEA) investigations of VLC RBC generate similar results as viscosity measurements. Mixtures of bisphenol A glycidyl methacrylate (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) as well as the pure resins were investigated and compared with two commercial VLC dental resins and RBCs (VOCO, Arabesk Top and Grandio). Shear viscosity data was obtained using a Haake Mars III, Thermo Scientific. Ion viscosity measurements performed by a dielectric cure analyzer (DEA 231/1 Epsilon with Mini IDEX-Sensor, Netzsch-Gerätebau). Shear viscosity depends reciprocally on the mobility of molecules, whereas the ion viscosity also depends on the ion concentration as it is affected by both ion concentration and mixture viscosity. Except of pure TEGDMA, shear and ion viscosities depend on the resin composition qualitatively in a similar manner. Furthermore, shear and ion viscosities of the commercial VLC dental resins and composites exhibited the same temperature dependency regardless of filler content. Application of typical rheological models (Kitano and Quemada) revealed that ion viscosity measurements can be described with respect to filler contents of up to 30vol.%. Rheological behavior of a VLC RBC can be characterized by DEA under the condition that the ion concentration is kept constant. Both methods address the same physical phenomenon - motion of molecules. The proposed relations allows for calculating the viscosity of any Bis-GMA-TEGDMA mixture on the base of the viscosities of the pure components. This study demonstrated the applicability of DEA investigations of VLC RBCs with respect to quality assurance purposes. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

The effect of shear and extensional viscosities on atomization of Newtonian and non-Newtonian fluids in ultrasonic inhaler.

Science.gov (United States)

Broniarz-Press, L; Sosnowski, T R; Matuszak, M; Ochowiak, M; Jabłczyńska, K

2015-05-15

The paper contains results of the experimental study on atomization process of aqueous solutions of glycerol and aqueous solutions of glycerol-polyacrylamide (Rokrysol WF1) in an ultrasonic inhaler. In experiments the different concentration aqueous solutions of glycerol and glycerol-polyacrylamide have been tested. The results have been obtained by the use of laser diffraction technique. The differences between characteristics of ultrasonic atomization for test liquids have been observed. The analysis of drop size histograms shows that the different sizes of drops have been formed during atomization process. The present study confirmed the previous reports which suggested that the drops size changes with the increase in viscosity of solution changes in spray characteristics were also observed. It has been shown that the shear and extensional viscosities affect the process of atomization. Copyright © 2015 Elsevier B.V. All rights reserved.

Viscosity overshoot in the start-up of uniaxial elongation of low density polyethylene melts

DEFF Research Database (Denmark)

Rasmussen, Henrik K.; Nielsen, Jens Kromann; Bach, Anders

2005-01-01

The transient uniaxial elongational viscosity of BASF Lupolen 1840D and 3020D melts has been measured on a filament stretch rheometer up to Hencky strains of 6-7. The elongational viscosity of both melts was measured at 130 degrees C within a broad range of elongational rates. At high elongation ...

Body fat and blood rheology: Evaluation of the association between different adiposity indices and blood viscosity.

Science.gov (United States)

Tripolino, Cesare; Irace, Concetta; Carallo, Claudio; Scavelli, Faustina Barbara; Gnasso, Agostino

2017-01-01

In recent years, new measures of body adiposity have been introduced: lipid accumulation product (LAP), body adiposity index (BAI) and body shape index (ABSI). These indices have been demonstrated to better associate with cardiovascular disease than other measures of adiposity. The aim of the present study was to evaluate if LAP or BAI better associate with blood viscosity than other measures of adiposity (body mass index, BMI; waist circumference, WC; waist-to-hip ratio, W/HR; waist-to-height ratio, W/HtR). 344 subjects were recruited for the present investigation. Exclusion criteria were: diabetes, elevated triglycerides, smoking and drug use. Blood lipids and glucose were measured by routine methods. Blood and plasma viscosity were measured by a cone-plate viscometer. Adiposity measures were computed as previously described. In simple correlation analyses, blood viscosity (BV) correlated with BMI, BAI, and LAP in males and with LAP in females. Correlations between plasma viscosity and adiposity indices were weak and not statistically significant. Other variables significantly related with BV were: gender, HDL- and LDL-Cholesterol, and triglycerides (p index is strongly associated to blood viscosity. This result, along with previous evidence, identifies LAP index as a potential cardiovascular risk marker.

Viscosity measurements and correlations of binary mixtures: 1,1,1,2-tetrafluoroethane (HFC-134a)+tetraethylene glycol dimethylether (TEGDME)

DEFF Research Database (Denmark)

Monsalvo, Matias Alfonso; Baylaucq, A.; Reghem, P.

2005-01-01

.15-373.15 K. The measurements have been carried out with a failing body viscometer for four molar fractions x(1) =(0.28, 0.44, 0.63 and 0.88). The density values of this system were interpolated from previous results obtained at the laboratory. All of the available viscosity data, including pure HFC-134a...

Effect of viscosity on learned satiation

NARCIS (Netherlands)

Mars, M.; Hogenkamp, P.S.; Gosses, A.M.; Stafleu, A.; Graaf, C.de

2009-01-01

A higher viscosity of a food leads to a longer orosensory stimulation. This may facilitate the learned association between sensory signals and metabolic consequences. In the current study we investigated the effect of viscosity on learned satiation. In two intervention groups a low viscosity (LV)

Effects of powdered versus liquid barium on the viscosity of fluids used in modified swallow studies

International Nuclear Information System (INIS)

Baron, J.; Alexander, T.

2003-01-01

To determine if the viscosity of thickened juice mixtures used in modified barium swallow studies significantly changes with the addition of powdered barium. We also describe a test formulation created using liquid barium, which has a negligible effect on juice viscosity. The viscosities of water and standardized honey- and nectar-consistency juices mixed with different amounts of powdered barium were measured by timing the laminar flow of a given initial hydrostatic head of fluid under gravity though an orifice of fixed diameter. Standardized juices were then mixed with a liquid formulation of barium and with measured quantities of water to produce viscosities that more closely equated with those of the standardized juices. With the addition of powdered barium, viscosity increased in all fluids, most markedly with the nectar-consistency juice. Liquid barium formulations maintained the viscosities of the original thickened juices. Rendering juices radio-opaque with barium powder results in dramatic increases in the viscosity of the resulting mixture and compromises diagnostic accuracy. Liquid barium preparations have the advantage that they can be rapidly and accurately dispensed by syringe, and their use does not significantly increase the viscosity of the preparation. (author)

Effects of powdered versus liquid barium on the viscosity of fluids used in modified swallow studies

Energy Technology Data Exchange (ETDEWEB)

Baron, J.; Alexander, T. [Univ. of Alberta, Dept. of Radiology, Edmonton, Alberta (Canada)

2003-06-01

To determine if the viscosity of thickened juice mixtures used in modified barium swallow studies significantly changes with the addition of powdered barium. We also describe a test formulation created using liquid barium, which has a negligible effect on juice viscosity. The viscosities of water and standardized honey- and nectar-consistency juices mixed with different amounts of powdered barium were measured by timing the laminar flow of a given initial hydrostatic head of fluid under gravity though an orifice of fixed diameter. Standardized juices were then mixed with a liquid formulation of barium and with measured quantities of water to produce viscosities that more closely equated with those of the standardized juices. With the addition of powdered barium, viscosity increased in all fluids, most markedly with the nectar-consistency juice. Liquid barium formulations maintained the viscosities of the original thickened juices. Rendering juices radio-opaque with barium powder results in dramatic increases in the viscosity of the resulting mixture and compromises diagnostic accuracy. Liquid barium preparations have the advantage that they can be rapidly and accurately dispensed by syringe, and their use does not significantly increase the viscosity of the preparation. (author)

Effect of tellurium on viscosity and liquid structure of GaSb melts

Energy Technology Data Exchange (ETDEWEB)

Ji Leilei [School of Material Science and Engineering, Jinan University, Jinan 250022 (China); Geng Haoran [School of Material Science and Engineering, Jinan University, Jinan 250022 (China)], E-mail: mse_genghr@ujn.edu.cn; Sun Chunjing [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Teng Xinying; Liu Yamei [School of Material Science and Engineering, Jinan University, Jinan 250022 (China)

2008-04-03

The behavior of GaSb melt with tellurium addition was investigated using viscometer and differential scanning calorimetry (DSC). Normally, the viscosity of all melts measured decreased with the increasing temperature. However, anomalous transition points were observed in the temperature dependence of viscosity for Ga-Sb-Te system. Corresponded with the abnormal points on the viscosity-temperature curves, there were thermal effect peaks on the DSC curves. Furthermore, viscous activation energy and flow units of these melts and their structural features were discussed in this paper.

Blood and plasma viscosity in diabetes: possible contribution to late organ complications?

NARCIS (Netherlands)

Schut, N. H.; van Arkel, E. C.; Hardeman, M. R.; Bilo, H. J.; Michels, R. P.; Vreeken, J.

1992-01-01

It has been postulated that an increased whole blood and plasma viscosity contribute to diabetic organ complications. Blood viscosity was measured in 30 controls and four groups of insulin-dependent diabetic patients at three shear rates: 70 sec-1, 0.5 sec-1 and 0.05 sec-1. Results were compared

Microfluidics for simultaneous quantification of platelet adhesion and blood viscosity

Science.gov (United States)

Yeom, Eunseop; Park, Jun Hong; Kang, Yang Jun; Lee, Sang Joon

2016-01-01

Platelet functions, including adhesion, activation, and aggregation have an influence on thrombosis and the progression of atherosclerosis. In the present study, a new microfluidic-based method is proposed to estimate platelet adhesion and blood viscosity simultaneously. Blood sample flows into an H-shaped microfluidic device with a peristaltic pump. Since platelet aggregation may be initiated by the compression of rotors inside the peristaltic pump, platelet aggregates may adhere to the H-shaped channel. Through correlation mapping, which visualizes decorrelation of the streaming blood flow, the area of adhered platelets (APlatelet) can be estimated without labeling platelets. The platelet function is estimated by determining the representative index IA·T based on APlatelet and contact time. Blood viscosity is measured by monitoring the flow conditions in the one side channel of the H-shaped device. Based on the relation between interfacial width (W) and pressure ratio of sample flows to the reference, blood sample viscosity (μ) can be estimated by measuring W. Biophysical parameters (IA·T, μ) are compared for normal and diabetic rats using an ex vivo extracorporeal model. This microfluidic-based method can be used for evaluating variations in the platelet adhesion and blood viscosity of animal models with cardiovascular diseases under ex vivo conditions. PMID:27118101

Glass viscosity calculation based on a global statistical modelling approach