The surface of a thin liquid film with a nonconstant curvature is unstable, as the Laplace pressure drives a flow mediated by viscosity. We present the results of experiments on one of the simplest variable curvature surfaces: a thin polymer film with a step. Height profiles are measured as a function of time for a variety of molecular weights. The evolution of the profiles is shown to be self-...

Strain sensors build up directly on machine components by thin film techniques enable measurement of forces, strain and pressure even in harsh environments. Up to day, the application of thin film sensors is restricted to planar surfaces due to limitations in standard patterning techniques. We present an alternative patterning method based on laser thin film ablation. During laser processing of...

A theoretical investigation into the prediction and measurement of squeeze film stiffness and damping for double hole entry hybrid journal bearings has been undertaken together with a review of previous work to identify critical bearing parameters. The analysis used a partial differentiation of the Poiseuille and Hagen-Poiseuille flow equations to develop a mathematical model for the bearing sq...

An in situ optical absorbance measurement was used to study the growth dynamics of vertically aligned single-walled carbon nanotubes (VA-SWCNTs) synthesized by chemical vapor deposition of ethanol. The growth rate of the VA-SWCNT film was found to decay exponentially from an initial maximum, resulting in an effective growth time of approximately 15 minutes. Investigation of various growth condi...

we investigated the issue of noise pollution in the bidboland gas refineryby noise measurement and surveys. the bidboland gas refinery has several process units.the sound pressure levels were measured at several places, such as units of 200, 300,400, 500, boiler, powerhouse area, cooling towers pumps, and maintenance area, and thecorresponding noise maps were produced by using sound plan softwa...

a modified model has been analytically developed to describe the induction time of an elliptic air bubble in contact with an elliptic hydrophobic oil droplet. the role of hydrophobicity was revealed in the slippage of liquid over the surfaces of bubble and droplet. in this condition, the analytical relationships for pressure distribution and consequently hydrodynamic resistance force through th...

Objective: To compare the coefficient of friction (CoF) of skin against fabric when the skin is covered with a liquid barrier film versus a silicone dressing, relative to a bare skin baseline. Approach: A laboratory instrument allowing the measurement of friction between two surfaces was used to compare the CoF between a fabric representing bed linen (100% cotton) and the skin of two laboratory...

Salt crystallization is a major cause of weathering of rocks, artworks and monuments. Damage can only occur if crystals continue to grow in confinement, i.e. within the pore space of these materials, thus generating mechanical stress. We report the direct measurement, at the microscale, of the force exerted by growing alkali halide salt crystals while visualizing their spontaneous nucleation an...