Coaxial

Driver and pick-up windings are coaxial (for small tubing diameters). 

On. CM, H O, and CO [31, 32, ]. A few negative ions have been studied using coaxial fast-ion/laser... 

These days, remarkably high-resolution spectra are obtained for positive and negative ions using coaxial-beam spectrometers and various microwave and IR absorption teclmiques as described earlier. Infonnation on molecular bond strengths, isomeric fonus and energetics may also be obtained from the teclmiques discussed earlier. The kinetics of cluster-ion fonuation, as studied in a selected-ion flow tube (SIFT) or by high-pressure... 

Waveguides are coimnonly used to transmit microwaves from the source to the resonator and subsequently to the receiver. For not-too-high-frequency radiation (<10 GHz) low-loss MW transmission can also be achieved usmg strip-lines and coaxial cables. At the output of a klystron an isolator is often used to prevent back-reflected microwaves to perturb the on-resonant klystron mode. An isolator is a microwave-ferrite device that pemiits the transmission of microwaves in one direction and strongly attenuates their propagation in the other direction. The prmciple of this device involves the Faraday effect, that is, the rotation of the polarization... 

Aono M, Katayama M and Nomura E 1992 Exploring surface structures by coaxial impact collision ion scattering spectroscopy (CAICISS) Nucl. Instrum. Methods B 64 29-37... 

Figure 2.3 Definition of variables for concentric cylinder viscometers (a) the rotating cylinder and (b) the coaxial cylinders.

These modes of operation ate used in conjunction with the two most popular energy analyzers, the cylindrical mirror analyzer (CMA) and the concentric hemispherical analyzer (CHA). The most common form of the CMA used today is the double-pass version diagramed in Eigute 21. This device consists of two perfectly coaxial cylinders of radii r and r. The outer cylinder is held at a potential of (— ) and the inner cylinder is held at ground. The... 

A widely used type of pump—mixer—settler, developed by IsraeH Mining Industries (IMI) (115), is shown in Figure 13a. A unit having capacity 8.3 m /min (2000 gal /min) has been used in phosphoric acid plants (116). The unique feature of this design is that the pumping device is not required to act as the mixer, and the two phases are dispersed by a separate impeller mounted on a shaft miming coaxially with the drive to the pump. 

The theory and appHcation of SF BDV and COV have been studied in both uniform and nonuniform electric fields (37). The ionization potentials of SFg and electron attachment coefficients are the basis for one set of correlation equations. A critical field exists at 89 kV/ (cmkPa) above which coronas can appear. Relative field uniformity is characterized in terms of electrode radii of curvature. Peak voltages up to 100 kV can be sustained. A second BDV analysis (38) also uses electrode radii of curvature in rod-plane data at 60 Hz, and can be used to correlate results up to 150 kV. With d-c voltages (39), a similarity rule can be used to treat BDV in fields up to 500 kV/cm at pressures of 101—709 kPa (1—7 atm). It relates field strength, SF pressure, and electrode radii to coaxial electrodes having 2.5-cm gaps. At elevated pressures and large electrode areas, a faH-off from this rule appears. The BDV properties ofHquid SF are described in thehterature (40—41). 

Particle Contamination. In assembling large, high voltage equipment such as coaxial lines, contamination by metal particles may occur which may decrease the dielectric strength under various conditions by 5 to 10-fold (44—45). Metal needles are the worst contaminants and electrostatic traps or adhesive areas have been designed to cope with them (46). 

Electrical Applications. The largest application of PTFE is for hookup and hookup-type wire used in electronic equipment in the military and aerospace industries. Coaxial cables, the second largest appHcation, use tapes made from fine powder resins and some from granular resin. Interconnecting wire appHcations include airframes. Other electrical appHcations include computer wire, electrical tape, electrical components, and spaghetti tubing. 

D. T. Tilin and co-workers, "Production of Acetylene by Electrocracking of Natural Gas ia a Coaxial Reactor," translated from J. Jippl. Chem. ULLR 42(3), 648 (1969). 

Data Communication Wires. Electronic cables such as data communication wires employ three basic designs coaxial, twisted pair, and fiber optics (3,4) (Eig. 1). Coaxial cables are so named because the axis of curvature of its outer conductor is concentric to its inner central wire. The metal braiding wrapped around the insulated center wire acts as the return current conductor in addition to shielding the wire from various interferences. 

Eig. 1. Cable designs (a) coaxial cable (b) twisted pair cable can be unshielded, as in regular telephone wiring, or shielded (as shown here) with braiding or... 

For coaxial cables, the following electrical properties related to the dielectric constant of the core material and the dimensions determine the quaUty of the signal impedance, capacitance, attenuation, crosstalk, and time delay and velocity of propagation. 

Impedance. Impedance defines the relationship of voltage and current in a coaxial cable. The electrical requirements of the hardware dictate the impedance values for the interconnecting cables. Most coaxial cables are designed to match the impedances required by electronic hardware. 

Coaxial (Concentric Cylinder) Viscometer, The eadiest and most common type of rotational viscometer is the coaxial or concentric cylinder instmment. It consists of two cylinders, one within the other (cup and bob), keeping the specimen between them, as shown in Figure 27. The first practical rotational viscometer consisted of a rotating cup with an inner cylinder supported by a torsion wire. In variations of this design the inner cylinder rotates. Instmments of both types ate useful for a variety of apphcations. 

The Nametre Rotary B rotational viscometer measures torque in terms of the current needed to drive the d-c motor at a given speed while a material is under test. The standard sensors are coaxial cylinders or Brookfield disk-type spindles, but a cone—plate system is also available. The viscosity range for the coaxial cylinder sensors is 5 to 5 x 1(T mPa-s, and the maximum shear rate is 200. ... 

Another type of electronic connector joins coaxial conductors. These have a soHd or stranded center-conductor surrounded by a dielectric. The dielectric is covered with a conductive shield made of metal braid or tape and with a layer of insulation. Coaxial cable connectors terminate the center-conductor and the shield. These are used primarily in radio frequency circuits. The shape, dimensions, and materials of an electronic connector shell or stmcture may have to be designed to shield the connection from electromagnetic and radio frequency interferences in many appHcations. 

FIG. 5-16 View factors for a system of two concentric coaxial c to inner cylinder, (h) Inner surface of outer cylinder to itself. 

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