Hemispherical ends

The basic device is very simple. A tip of refractory metal, such as tungsten, is electrically heat-polished to yield a nearly hemispherical end of about 10" cm radius. A potential of about 10 kV is applied between the tip and a hemispherical fluorescent screen. The field, F, falls off with distance as kr, and if the two radii of curvature are a and b, the total potential difference V is then... 

Flard spherocylinders (cylinders witli hemispherical end caps) were studied using computer simulations [118]. In addition to a nematic phase, such particles also display a smectic-A phase, in which tire particles are arranged in liquid-like layers. To observe tliis transition, ratlier monodisperse particles are needed. The smectic-A phase was indeed observed in suspensions of TMV particles [17]. 

Calculation of Tank Volume A tank may be a sin e geometrical element, such as a cylinder, a sphere, or an ellipsoid. It may also have a compound form, such as a c inder with hemispherical ends or a combination of a toroid and a sphere. To determine the volume, each geometrical element usually must be calculated separately. Calculations for a full tank are usually simple, but calculations for partially filled tanks may be complicated. 

The vessel under gas pressure bursts into equal fragments. If there are only two fragments and the vessel is cylindrical with hemispherical end-caps, the vessel bursts perpendicular to the axis of symmetry. If there are more than two fragments and the vessel is cylindrical, strip fragments are formed and expand radially about the axis of symmetry. (The end caps are ignored in this case.)... 

A horizontal, cylindrical, tank, with hemispherical ends, is used to store liquid chlorine at 10 bar. The vessel is 4 m internal diameter and 20 m long. Estimate the minimum wall thickness required to resist this pressure, for the cylindrical section and the heads. Take the design pressure as 12 bar and the allowable design stress for the material as 110 MN/m2. 

Incendiary Stick Grenade had light steel cylindrical body with hemispherical ends and wooden handle threaded into the base. Length of body 13.2 inches, diam 2.1 inches and length of handle 5.3 inches. The body was filled with 41 rubber pellets, each impregnated with a soln of WP in carbon disulfide. The pellets were scattered by means of a small central burster chge. 

The apparatus used is represented in Fig. 376 in vertical section taken through the centre of the apparatus. It consists of a cast-iron cistern, A, having semicircular ends, and open on the upper side at one end of it is a cylindrical vessel, b, with hemispherical ends. This vessel is of considerable strength, and ahould be capable of withstanding a pressure of five... 

Combustion Rate of Carbon—Eq (12-18) can hardly be expected to hold at ignition temperatures. Indeed it is doubtful whether it will hold at temperatures much above 400 deg C even in the case of anthracite coal. Above this point the carbon ignites and a completely new set of conditions pertains to the problem. Studies on the combustion rate of carbon particles have been studied in considerable detail by several investigators. The general method used was described by Parker and Hottel (1936). The device used consists of a furnace in which is suspended a cylindrical rod of carbon 2.5 cm in diameter with a hemispherical end. The rod is mounted on a porcelain tube and suspended from one arm of a balance so that the hemispherical end is downward in the furnace. In this way loss of weight is easily determined. The surface of the specimen is also capable of measurement. Known volumes of air heated to the required temperatures are then made to flow past the carbon, and by means of a small quartz sampling-tube (which can be adjusted at any distance from the specimen) samples are withdrawn for analysis. In this way samples of air may -be analyzed for the amount of carbon dioxide and oxygen present at any distance from the heated particle-surface. 

Image analysis provide information based on the number of cells examined the question of the volume is therefore often raised, as some other sizing systems (Coulter counter, laser diffraction granulometers) provide volume-based results. It is important to note that, because an image is essentially a plane, volume estimation will require some assumption on the 3D-shape. Bacteria are often considered as cylinders with hemispherical ends at each side. Based on these simple geometrical assumptions their volume can be computed [94,95] ... 

Representations of mesophyll cells showing how geometry affects Ames/A. Spheres or cylinders with hemispherical ends in an orthogonal (right-angled) array lead to the indicated Ames/A. The length of the lateral walls of the palisade cells in panel c is six times the radius r. 

Sokplskys used a rotating cylinder with a hemispherical end. Mooney and Ewart used two rotating cylinders with conical bases with different angles. Lillieio measured the torque on an inner cylinder with a rotating outer cylinder. 

FIG, 6.46. A constant level device, (a) Double points from 25 mm diameter tubing, (b) One end blown to a hemisphere, (c) Shows a 8 mm diameter hole blown in tlie hemispherical end. (d) Tlie prepared overflow tube, of 6 mm tube and witli a 10 mm diameter bulb, inserted into tlie body of tlie constant level device, (e) Tlie ring seal completed, and the inlet tube ready to join on. (f) The outlet tube joined on. All the heated glass, at this end of the device, should be annealed, (g) Shows tlie completed constant level device witli tlie top blown out and rimmed. 

The amount of gas transferred to the liquid slug from the hemispherical ends is equal to the mass transferred from the liquid slug to the wall i.e.. 

Mass transfer according to this mechanism is described by Eq. (25). The mass transfer area of the hemispherical ends of the gas bubble is given by... 

Calculated from optimum theoretical capsule shape, each part a cylinder with a hemispherical end. 

Elongated cylindrical, rodlike micelles with hemispherical ends (prolate ellipsoids)... 

Cylindrical vessels and horizontal tanks are used for the storage of fluids in the chemical process industries. Various level instruments are employed to determine the liquid level in process vessels. The exact liquid volume can be obtained either by calibration of the vessels or by tedious calculations. Partial volumes for horizontal, cylinders with flat, dished, elliptical, and hemispherical ends, and for vertical cylinders are employed for storing process fluids. 

At the present time, the major types of micelles appear to be (1) relatively small, spherical structures (aggregation number <100), (2) elongated cylindrical, rodlike micelles with hemispherical ends (prolate ellipsoids), (3) large, flat lamellar... 

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