Circular discs

At its simplest, the mirror is a circular disc, of diameter 2a and mean thickness f, simply supported at its periphery (Fig. 7.2). When horizontal, it will deflect under its own weight M when vertical it will not deflect significantly. We want this distortion (which changes the focal length and introduces aberrations into the mirror) to be small... 

The equation for the intrinsic chord distribution of a circular disc of diameter 1 has first been published by P. W. Schmidt [204]... 

Experiments were conducted in a large (-26 m3) radon/thoron test facility (RTTF) designed for calibration purposes and simulation studies (Bigu, 1984). A number of different materials were exposed in the RTTF to a radon/radon progeny or thoron/thoron progeny atmosphere. Exposure of the materials was carried out under laboratory-controlled conditions of radiation level, aerosol concentration, air moisture content and temperature. The materials used were in the form of circular discs of the same thickness (-0.5 mm) and diameter (-25 mm), and they were placed at different locations on the walls of the RTTF at about 1.6 m above the floor. Other samples were placed on horizontal trays. Samples (discs) of different materials were arranged in sets of 3 to 4 they were placed very close to one another to ensure exposure under identical conditions. Exposure time was at least 24 hours to ensure surface activity equilibrium, or near equilibrium, conditions. 

A very powerful method for the evaluation of solubility differences between polymorphs or solvates is that of intrinsic dissolution, which entails measurements of the rates of solution. One method for this work is to simply pour loose powder into a dissolution vessel, and to monitor the concentration of dissolved solute as a function of time. However, data obtained by this method are not readily interpretable unless they are corrected by factors relating to the surface area or particle size distribution of the powder. In the other approach, the material to be studied is filled into the cavity of a circular dissolution die, compressed until it exhibits the effective planar surface area of the circular disc, and then the dissolution rate is monitored off the surface of the rotating disc in the die [130],... 

The analysis takes place in a circular disc called the transfer disc or rotor (Figure 6.1) made of an inert material such as Teflon or acrylic whose surface properties allow minimal adhesion of liquid. It contains radially arranged sets of cavities, each set composed of two or more interconnected cavities, one for the sample and the others for the reagents (Figure 6.2). Small measured volumes of sample and reagent, e.g. 5 - 200/rl, are automatically pipetted into the appropriate wells so that each set contains a different sample but the same... 

The rotated disc electrode (RDE) is one of the most commonly employed hydro-dynamic electrodes. Figure 7.1 shows a schematic representation of a typical RDE. The electrode itself is a flat, circular disc of metal, graphite or an other conductor, and has a radius of r its area A, therefore, is straightforwardly nr. The disc is embedded centrally into one flat end of a cylinder of an insulatory material such as Teflon or epoxy resin. Behind the face of the electrode is an... 

The answers to the previous six questions are yes, yes, no, 100 percent, zero, and zero (for all parts of question 6). To help understand these answers, consider the act of stuffing rigid circular regions of a plane into a sphere. If the circular discs are really two-dimensional, they have no thickness or volume. Therefore, in theory, you could fit an infinite number of these circles into a sphere—provided that the sphere s radius is slightly bigger than the circle s radius. If the sphere s radius were smaller, even one circle could not fit within the enclosed volume since it would poke out of the volume. Therefore, in answer to question 1, the volume of a whale could reside comfortably in a 24-D sphere with a radius of 2 inches. In fact, an infinite number of whale volumes could fit in a 24-D sphere. Likewise, in answer to question 2, a 1000-D sphere with a radius of 2 inches could contain a volume equivalent to that of a whale. However, you could not physically stuff a whale into either of these spheres because the whale has a minimum length that will not permit it to fit. (Con-... 

Triaxial tests usually involve more elaborate testing equipment and more precise measuring techniques than those normally used for uniaxial and biaxial measurements. In the poker chip test (33, 59) the faces of a thin circular disc are bonded to rigid plates (Figure 18). The speci-... 

The interpretation of measurements is discussed for the particular cases of collectors shaped like a circular cylinder, an aerofoil or a circular disc. It is shown through the trajectories of representative droplets that correction factors are needed to relate the numbers caught to the numbers present in the unobstructed flow. These factors are given in graphical form, and a practical application is discussed. 

For preliminary work, a circular disc electrode with a diameter in the 1-5 mm range is usually used. The substrate concentrations are typically between 1 and 10 mM and the voltage sweep rates are usually between 50 mV s 1 and 500 V s 1. Sometimes the voltage sweep is continued to include several E — t half-cycles. 

The output bias contact 107 is shaped to concentrate an electric field bias in the immediate vicinity of the contact 107. This concentrated field sweeps away minority carriers which otherwise accumulate near the output contact. It is proposed that the contact 107 is shaped by extending it towards input bias contact 105, or that the detector material 103 near this contact 107 is configured by slotting or tapering, or that an annular ring input bias contact surrounds a circular disc output contact. 

Fig. 2 Single crystals of linear polyethylene (a) crystallized at 130 °C at atmospheric pressure (b) crystallized at 0.3 GPa as uniform circular discs then given a complex twinned texture with lines inclined at 60° during return to ambient temperature and pressure from [12]...

Figure 2.10 Operating method of eccentric, synchronous, co-rotating, circular discs ...

This patent concerns a single-flighted, asymmetrical screw profile which is mainly composed of a circular disc with a small tip and a small root region. 

Spreading disc flow (circular disc, centre gate)... 

Dow s patented scrapless forming process is identified as the SFP process. An extruder produce a biaxially oriented sheet (Chapter 5). In turn the sheet is slit and cut into square blanks. These blanks are heated and pressed into circular disc with a lip. Immediately or latter after reheating, the disc is thermoformed into a shape such as a cup. 

Spin casting can use plastic molds, such as silicone, to produce close tolerance, highly cost effective, limited production in a variety of materials. The process uses easily adjustable centrifugal force to inject liquid thermoset plastics into a circular disc-shaped elastomeric mold under pressure, completely and rapidly filling the mold cavities. 

The ceramic circular discs (1cm diameter, 0.1cm thick) were prepared by pressing the powder, using a pressure of 8 MPa, with adding in 8 % PVA solution as binder, and sintering at 1 300 °C for 2 hours. Then the ceramic samples were prepared by electroding the sintered disc with silver paint. 

Because of the logarithmic term the drag changes but slowly with the ratio of major to minor axes. A thin circular disc of diameter a, thickness h, will have both a horizontal (m ) and a vertical velocity (mJ component of velocity (Figure 6.2), where ... 

Winkelmann used two concentric brass cylinders with the liquid in the intervening space, the whole being immersed in ice, and the temperatures of the inner cylinder was determined (see 4.VIIG). Weber used the fito method tried by Guthrie, the liquid being contained between two circular discs of copper separated by three thin glass spacers. The lower plate was put in contact with ice, and the fall in temperature of the upper plate followed by a thermocouple with one junction soldered to the plate. This method was... 

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