When a shear ultrasonic wave is incident on a solid and liquid boundary, the proportion that is reflected depends on the liquid viscosity. This is the basis for some instruments for on-line measurement of bulk liquid viscosity. In machine elements, the lubricant is usually present in a thin layer between two rubbing solid surfaces. The thin film has a different response to an ultrasonic shear w...

This paper studies a solid film lying on a liquid layer, which in turn lies on a solid substrate. It is well known that, subject to a compressive membrane force, the solid film wrinkles, dragging the liquid underneath to flow. When the solid film is very thin, the ratio between the number of atoms at the surface and that in the bulk becomes significant, so that surface stress contributes to the...

For the thickness 0 5 a liquid or solid quantum f i lm, like liquid helium or solid hydrogen, there exist still open questions about how the film thickness develops in certain limits. One of these is the thick film limit, i.e., the crossover from the thick film to bulk. We have performed rneasurements in this range using the surface plasmon resonance technique and an evaporated h g film deposit...

We provide a theoretical description of the dynamics of a liquid film perturbed by a nano-object. Our analysis is based on the general dispersion relation for surface perturbations which is valid for films of arbitrary thickness. In the case of thin liquid films the lubrication approximation is retrieved. The relevant time scales are derived and related to the characteristic length scales prese...

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...

Motivated by the development of lubricant-infused slippery surfaces, we study a sessile drop of a nonvolatile (ionic) liquid which is embedded in a slowly evaporating lubricant film (n-decane) on a horizontal, planar solid substrate. Using laser scanning confocal microscopy we imaged the evolution of the shape of the liquid/liquid and liquid/air interfaces, including the angles between them. Re...

for a paper presentation at the 12th international symposium on applications of laser techniques to fluid mechanics Investigation of film flow by means of μ-PIV P. Schober, B. Richter, O. Schäfer and K. Dullenkopf Lehrstuhl und Institut für Thermische Strömungsmaschinen (ITS) Universität Karlsruhe Germany Shear-driven liquid wall films play a major role in the fuel preparation process in state ...

The blanket system is one of the most important components in a fusion reactor because it has a major impact on both the economics and safety of fusion energy. The primary functions of the blanket in a deuterium/tritium-fueled fusion reactor are to convert the fusion energy into sensible heat and to breed tritium for the fuel cycle. The liquid-metal blanket concept requires an electrically insu...

A mathematical model which can be predicted the flow and heat transfer characteristics for evaporating thin film region in micro channel is presented and an analytical investigation is performed by using the presented model. For the formulation of modeling, the flow of the vapor phase and the shear stress at the liquid-vapor interface are considered. In addition, the disjoining pressure and the...

Visual observations on rates and modes of water penetration into black bean seeds and into wheat and sorghum kernels during conditioning were accomplished by an autoradiographic procedure that eliminates a freezing microtome and liquid and stripping film emulsions. Seeds soaked in tritiated H(2)O were hand sectioned before freeze-quenching in liquid N(2) and subsequent block autoradiography on ...