The crystal structure of the title compound, C(12)H(10)O(2), was originally determined by Rajan [Acta Cryst. (1978). B34, 998-1000] using intensity data estimated from Weissenberg films. This redetermination provides a structure with significantly improved precision with respect to the geometric parameters. In the crystal structure, inter-molecular O-H⋯O hydrogen bonds, weak C-H⋯O hydrogen bond...

We present a molecular dynamics simulation study of crystal nucleation from undercooled melts of n-alkanes, and we identify the molecular mechanism of homogeneous crystal nucleation under quiescent conditions and under shear flow. We compare results for n-eicosane (C20) and n-pentacontahectane (C150), i.e., one system below the entanglement length and one above, at 20%-30% undercooling. Under q...

We present special numerical techniques for viscoelastic fluid flow utilizing a fully coupled monolithic multigrid finite element approach with consistent edge-oriented stabilization technique. The governing equations arise from the Navier-Stokes for the Oldroyd-B type of fluid with the help of the log-conformation reformulation to allow a wide range of Weissenberg numbers. The resulting nonlin...

We investigate the use of two distinct and complementary approaches to measuring the viscometric properties of low viscosity complex fluids at high shear rates up to 80,000 s−1. Firstly we adapt commercial controlled-stress and controlled-rate rheometers to access elevated shear rates by using parallel plate fixtures with very small gap settings (down to 30 μm). The resulting apparent viscositi...

This work presents a finite volume method used to solve the relevant coupled equations for general electro-osmotic flows of viscoelastic fluids, using the upper-convected Maxwell and the simplified Phan-Thien–Tanner models. Three different implementations of the electro-osmosis physical models were carried out, which depend on the required level of approximation. In the first implementation, th...

This paper is concerned with regular flows of incompressible weakly viscoelastic fluids which obey a differential constitutive law of Oldroyd type. We study the newtonian limit for weakly viscoelastic fluid flows in IR or T N for N = 2, 3, when the Weissenberg number (relaxation time measuring the elasticity effect in the fluid) tends to zero. More precisely, we prove that the velocity field an...

In our previous work, we explored the dynamics of a dilute suspension of rigid dumbbells as a model for polymeric liquids in large-amplitude oscillatory shear flow, a flow experiment that has gained a significant following in recent years. We chose rigid dumbbells since these are the simplest molecular model to give higher harmonics in the components of the stress response. We derived the expre...

The focus of this manuscript is on two-dimensional mixed convection non-Newtonian nanofluid flow near stagnation point over a stretched surface with convectively heated boundary conditions. modeled equation representing nonlinear transformed into system ordinary differential equations by implementing appropriate similarity transformations. generated structure numerically solved applying the bvp...

Large-amplitude oscillatory shear flow (LAOS) is a popular for studying the nonlinear physics of complex fluids. Specifically, the strain rate sweep (also called the strain sweep) is used routinely to identify the onset of nonlinearity. In this paper, we give exact expressions for the nonlinear complex viscosity and the corresponding nonlinear complex normal stress coefficients for the Oldroyd ...