We present a kinetic model for active suspensions and analyze the behavior of a suspension subjected to slow steady simple shear. We give the stability analysis of the steady states and predict the rheology of such systems including an activity thickening or thinning behavior of the apparent viscosity and a negative apparent viscosity depending on the particle type, their flow alignment behavio...

The apparent viscosity (pseudoplastic viscosity) of mucilage of leucaena seed gum was calculated, based on flow curves, obtamed With multiple point viscometer. Attempts were made to correlate the various rheological properties, describIng the_ overall flow behaviOur of gum, with their concentrations. The relationship between N(exponential constant) and concentration was found to be a zero order...

crosslinked poly(acrylic acid)s were prepared using two types of crosslinker by precipitation polymerization method in a binary organic solvent. n,n’-methylenebisacrylamide (mba) and polyethylene glycol dimethacrylate (pegdma-330) were used as low-molecular weight and long-chain crosslinkers, respectively. the effect of various types of crosslinkers on polymer characteristics (i.e., gel content...

For more than 20 years it has been debated if yield stress fluids are solid below the yield stress or actually flow; whether true yield stress fluids exist or not. Advocates of the true yield stress picture have demonstrated that the effective viscosity increases very rapidly as the stress is decreased towards the yield stress. Opponents have shown that this viscosity increase levels off, and t...

In order to simulate the in vivo dissolution of drugs, biorelevant dissolution media (BDM), simulating the gastric or intestinal juices are often employed. For gastric BDM, pH, surface tension and osmolality is simulated, however, viscosity has, to our knowledge not been taken into account. The dissolution rate of a drug compound is influenced by the viscosity of the dissolution medium. In the ...

Near-infrared spectroscopy in diffuse reflection mode was used to evaluate the apparent viscosity of Para rubber field latex and concentrated latex over the wavelength range of 1100 to 2500 nm, using partial least square regression (PLSR). The model with ten principal components (PCs) developed using the raw spectra accurately predicted the apparent viscosity with correlation coefficient (r), ...

The objective of this present numerical model is to investigate the effect of shape of stenosis on blood flow through an artery using power-law fluid model. Blood is modeled as power-law fluid in a uniform circular tube with an axially non-symmetric but radially symmetric stenosis. The expressions for dimensionless resistance to flow, wall shear stress and apparent viscosity have been obtained....

In this work, we study the stationary Poiseuille flow of nematic liquidcrystals through a tube under a constant gradient pressure. We first examine the dynamics of steady-state system of Poiseuille flow with strong anchoring boundary conditions. For zero gradient pressure (equilibrium situation), the steady-state system can be converted essentially to a Hamiltonian system but it is not structur...

A new theoretical model based on the local composition concept (TNRF-mNRTL model) was proposed to express the short-range contribution of the excess Gibbs energy for the solutions containing polymer and electrolyte. This contribution of interaction along with the long-range contribution of interaction (Pitzer-Debye-Hückel equation), configurational entropy of mixing (Flory-Huggins relation)...

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 t...