Simple film trough

The surface condensers are here shown, G G G. This process of condensation was introduced and patented by Messrs. Pontieex and Wood of London, who have recently patented a simple and efficient method of connecting the pipes—admirably adapted for the colonies, and all places where skilled labor is difficult to be obtained. The condensers consist of one or more series of copper pipes, fixed to boxes at each end, with partitions to direct the current of the vapor. Above each series of pipes is iked a trough always kept full of water, and so constructed that the water trickles in a gentle shower, uniformly spread over the pipes, so as to keep them well covered with a thin film of water the lowest pipe is connected with a small pump, workod by the engine, which draws the condensed... 

There are many applications of ellipsometry in the measurement of mono-layer and sub-monolayer films. The theory of the optical signal to be expected from an adsorbed layer less than one monolayer thick has been placed on a firm footing by Smith [15] in some elegant experiments on adsorption in a Langmuir trough. Simultaneous ellipsometric and surface potential measurements were made on various molecules spread in thin layers on mercury as the surface pressure was varied. One conclusion was the simple result that the effective thickness divided by the thickness of the island molecules in the adsorbed islands was equal to the fractional coverage of the surface area. 

Double-drum dryers normally employ a nip-feed device with adjustable space between the drums that provides a means of controlling the film thickness [29]. Alternately, and in the case of single-drum types, a variety of feeding methods can be used to apply materials to the drum. The most usual is the simple dip or splash feed [29,37]. With this arrangement, good liquor circulation in the trough is desirable to avoid increasing the concentration of the feed by... 

No data on solutions are included either. Although there is considerable information in the literature on certain polymers, it is dependent on the particular choice of solvent and not amenable to systematic tabulation. The same is true of the wealth of adsorption from solution onto solids and spread film Langmuir trough data. Equations are available for calculating the surface tension of simple liquid mixtures that could be applied to polymers [14] and for calculating polymer solvent solution [15] surface tensions. 

One of the most popular and simple methods for making a surface tension measurement is the Wilhelmy plate or rod method. Here, either a flat plate (held vertically) or a simple rod is dipped into the fluid and then retracted slowly. The plate is designed to be very hydrophilic, so the water in the trough will wet the plate and be pulled upward as it is retracted. In this method, calculation of the surface tension is easy as the method is analogous to our previous definition of surface tension by pulling out a film from the bulk (Section 3.3). 

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