Concave domes

Steel. The steel container s most usual form is cylindrical with a concave (or flat) bottom and a convex top dome with a circular opening finished to receive a valve with a standard 2.54-cm opening. The three pieces (body, bottom, and top) are produced separately and joined by high speed manufacturing. The size of the container is described by its diameter and height to top seam, in that order. Hence a 202 x 509 container is 54.0 mm (2 /jg in.) in diameter by 141.3 mm (5 /jg in.) high. Tables of available sizes and overflow volumes and suggested fill levels can be readily obtained from manufacturers. 

The first of these reactions takes place at temperatures of about 150°C, the second reaction proceeds at about 550—660°C. Typical furnaces used to carry out the reaction include cast-iron retorts the Mannheim mechanical furnace, which consists of an enclosed stationary circular muffle having a concave bottom pan and a domed cover and the Laury furnace, which employs a horizontal two-chambered rotating cylinder for the reaction vessel. The most recent design is the Cannon fluid-bed reactor in which the sulfuric acid vapor is injected with the combustion gases into a fluidized bed of salts. The Mannaheim furnace has also been used with potassium chloride as the feed. 

The tank is typically about sixteen inches in diameter and about four to five feet tall. The top of the tank is domed upward and the bottom of the tank is also domed upward in a concave manner. The outside of the tank is insulated with a polyurethane foam insulation that is squirted into the gap between the tank and a thinner sheet metal jacket. The polyurethane is made of two different components that react and harden when mixed. Included in the mixture is a blowing agent that causes the polyurethane to expand in a foam-like manner. Prior to about 1980, water heaters were insulated with fiberglass insulation. The foam insulation process was developed to allow automation and increased manufacturing speed and reduced costs. A side benefit was improved insulating ability leading to a slight increase in efficiency. 

A previous edition of the dimensions standard also had a method intended for compression set test pieces which was similar except that the force on the foot was 850 30 mN and the contact members were either domed surfaces of 12.5 mm radius or a spherical contact of 6.35 mm diameter and a raised platform of 9.5 mm diameter. This use of curved surfaces for compression set is based on the fact that after compression, particularly with non-lubricated test pieces, the rubber may well have concave surfaces. This does not happen if the test piece is lubricated as is now the usual practice and, hence, the curved surfaces were eliminated. However, if concave test pieces are encountered it may well be better to resort to the old method... 

The Dome Matrix is constituted of a cylindrically shaped tablet, with one of the bases concave and the other convex [1]. Principally, the individual modules are designed to allow the convex base of one module to be inserted into the concave base of another. The axial section of each module appears as a dome, hence such assembly is named Dome Matrix. The assembly of two adjacent modules is mediated via frictional interlocking. The basic modules differ in their concave base design. The male model is characterized by an annular protrusion on the concave rim base, whereas the female model exhibits a concave base that receives the annular protrusion of the male model (Figure 7.2) [1]. 

Dished n Showing a symmetrical concave distortion of a flat or curved surface of a plastic object, so that, as normally viewed, it appears more concave than its design calls for. Opposite of domed. See also Warp and Sink Mark. 

In the CHARITE design, the polyethylene core has two domed (convex) surfaces, which articulate against the concave metallic endplates. In full flexion or extension, the core is (theoretically) free to translate and rotate, so that the polyethylene rim contacts the metallic rims of the end-plates (Figure 12.2). This artificial disc is implanted by an anterior approach. An excellent summary of the design can be found in a recent monograph [10]. 

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