Half-clamp

The seals in the clamp comprise either a standard hardness rubber (SHR) or a high hardness rubber (HHR), both of which are prepared via water-jet cutting from larger sheets. The seal is applied in a picture frame conhguration each half-clamp has an associated fully enclosed semicircular annulus, thus preventing fluid (leaking from a... 

The use of monomer-polymer doughs has been largely confined to the production of dentures. A plaster of Paris mould is first prepared from a supplied impression of the mouth. Polymer powder containing a suitable polymerisation initiator is then mixed with some monomer to form a dough. A portion of the dough is then placed in the mould, which is closed, clamped and heated in boiling water. After polymerisation, which usually takes less than half an hour, the mould is cooled and opened. This technique could also be usefully employed for other applications where only a few numbers-off are required but does not seem to have been exploited. 

This is a simple convenient expression for estimating the clamping force required for the disc. The same expression may also be used for more complex shapes where the projected area may be approximated as a circle. It will also give sufficiently accurate estimates for a square plate when the radius, R, in Fig. 4.41(a) is taken as half of the diagonal. 

The so-called hydro-vac pump, shown in Fig. II, 22, 2 (the upper half of the mercury reservoir and the column above it are insulated by a layer of asbestos), is an inexpensive, all-glass, mercury diffusion pump, which can be used in series either with an oil piunp or with a water filter pump (compare Fig. II, 21,1) capable of producing a vacuum of at least 2 mm. It is accordingly of particular value in the organic laboratory for vacuum distillations, fractionations, sublimations and pyrolyses as well as for molecular distillations (see Section 11,26). The hydro-vac pump, unlilce an oil pump, may be used in operations which evolve moisture and non-condensable or corrosive vapoius. In use the piunp is clamped in a vertical... 

In such an osmometer the lateral walls on the depth of the half cells are made up of perforated brass plates the width and the depth of each groove in the plate are 1.5 mm and the distance between two adjacent groove is also 1.5 mm. The diameter of osmometer cell is 11.5 cm. The semi-permeable membrane is clamped between the two half-cells. The solution is placed in the glass-tube having a needle-type stopcock and is fitted with pure solvent. The volume of the osmometer cell is about 7 ml. The assembled osmometer is put in a double-walled air thermometer. The temperature fluctuations in the thermostate are 0.05°C. 

As shown in Figure 4.2, the modified Ussing chamber system consists of two half chambers which when clamped together are separated by a piece of... 

Polyacetals and other engineering plastics cost about half that of cast metals, and are therefore used as replacements for cast metal-intense applications. They have been approved by the Food and Drug Administration for contact with foods. Some of the uses of molded polyacetals are as valves, faucets, bearings, appliance parts, springs, automotive window brackets, hose clamps, hinges, video cassettes, tea kettles, chains, flush toilet float arms, gears, shower heads, pipe fittings, pasta machines, desktop staplers, and air gun parts. 

A. 1 x 7-inch centrifuge tube immersed to half its height in an ice-water bath held in a 2-liter container E and held in place by a rubber covered clamp... 

Simple osmometers have also been developed by Adair particularly for aqueous colloidal solutions. A thimblc-typc collodion membrane is attached to a capillary tube and contains the solution, When equilibrium is established the difference in level inside and outside the capillary is measured, Capillary corrections are made. For organic solvents a dynamic type osmometer may be used. A membrane of large surface area is clamped between two half cells and attached to each half cell is a fine capillary observation tube. With such an apparatus, equilibrium is rapidly established between solution and solvent contained in the half cells, The volume of the half cell may be small (about 20 cubic centimeters), The level of the solvent is usually aiiangecl to be a little below the equilibrium position, and the height of the solvent in the capillary as a function of time is measured, This procedure is repeated with the level of the solvent just above the equilibrium position. A plot is then made of the half sum of these readings. 

A 2-1. round-bottom flask is clamped to a ring-stand and equipped with a rubber stopper protected with tin foil and carrying a glass stirrer with mercury seal and a reflux condenser. (Cf. Org. Syn. i, 4, Fig. 1, a.) As an outlet for the hydrogen chloride, the top of the condenser is provided with a bent tube which almost touches the surface of the water in a half-filled i-l. flask. 

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