The effectiveness of a proportional feedback control to suppress the Marangoni instability in a variable-viscosity fluid layer with a deformable free upper surface is investigated. Viscosity variation and deformable free surface have destabilizing effects on the stability limit. The stability thresholds for the short-scale mode are strongly dependent on viscosity variation and controller gain w...

A new concept for spinning unmagnetized plasma is demonstrated experimentally. Plasma is confined by an axisymmetric multicusp magnetic field and biased cathodes are used to drive currents and impart a torque in the magnetized edge. Measurements show that flow viscously couples momentum from the magnetized edge (where the plasma viscosity is small) into the unmagnetized core (where the viscosit...

Temperature dependent viscosity effect in buoyancy driven flow, of a gas or a liquid, in an enclosure filled with a porous medium is studied numerically, based on the general model of momentum transfer in a porous medium. The Arrhenius model, which proposes an exponential form of viscosity-temperature relation, is applied to examine three cases of viscositytemperature relation: constant, decrea...

The effective shear viscosity and frequency-dependent dynamic oscillatory shear spectra of water containing monovalent or divalent ions (ionic strength 25 mM), confined between mica crystals at 1-2 water molecules thickness, oscillated with twist angle with the period expected for the pseudohexagonal surface lattice. The effective viscosity varied by orders of magnitude as the twist angle was c...

   Drilling fluids are an essential component of the rotary drilling process used to drill for oil and gas on land and offshore environments. The injection of this nano particle into drilling fluid increases the viscosity levels fluids. In these experiments, the rheological properties of the fluid including apparent viscosity (AV), plastic viscosity (PV), yielding point (YP), mud c...

This report develops an ensemble or statistical eddy viscosity model. The model is parameterized by an ensemble of solutions of an ensemble-Leray regularization. The combined approach of ensemble time stepping and ensemble eddy viscosity modeling allows direct parametrization of the turbulent viscosity coefficient that gives an unconditionally stable algorithm. We prove that the model’s solutio...

The purpose of the study is to formulate and evaluate a new, cheap and effective natural mucoadhesive agent that can be used as an effective alternative for traditional mucoadhesive agent. The study procedure involved extraction of mucoadhesive agent from the Trigonellafoenumgraecum (fenugreek) seeds, solubility testing of the mucilage obtained, phytochemical testing, determination of swelling ...

Measurement of the variation of relaxation frequency of Brownian rotation of magnetic nanoparticles in a ferrofluid due to binding of organic molecules is a possible tool for detection of biomolecules in solution. We investigate frequencyand temperature-dependent magnetic behavior of model ferro-fluids of surfactant-coated Co nanoparticles, 20 nm in diameter, in dichlorobenzene in a wide concen...

Fluorescein transit tkne from pial arterioles to pial venules was measured in the mouse by analyzing motion pictures taken at 40 frames/sec. Increased blood pressure reduced the transit time. Increased blood viscosity lengthened the transit time. Viscosity was increased by rendering the animals polycythemic, or by infusions of high molecular weight dextran. Two different dexrrans were used. The...

the aim of this study was to investigate the rheological behavior and mucoadhesive nature of saliva substitutes, by incorporating various mucoadhesive polymers into an artificial saliva pump spray formulation. for this purpose various mucoadhesive polymers including cellulosic polymers in the range of 0.1-1.0% and carbomers such as c974p, c971, c934p and c971 in the range of 0.01-0.1% were adde...