Flow induction

Contact ignition by a block in which smoothfaced samples are rapidly brought into contact with a massive hot A1 block and induction times are determined at different block temps Ignition by a flow of gas (sic) in which sample cylinders of various diameters are introduced into a hot gas stream with the cylinder axis normal to the gas flow. Induction times are measured for varying gas compns and temps Results obtained.in Refs 14 15 are summarized in Table 4. Here the columns labelled Equation No and Figure No refer to Merz-hanov s article (Ref 14)... 

Temperature uniformity involves improvement by movement of radiating triatomic gases as well as convection poc. (See also chap. 5 of reference 51.) Concepts of this chapter will be facilitated by the following review of the laws of gas movement concerning buoyancy, velocity head, fluid friction between gases and solids, and flow induction. 

Fluid Friction, Velocity Head, Flow Induction... 

GRAPH 10.30 Three dipoles with common flow inductive CPE, resistor, and capacitive CPE and their representation as an equivalent electrical circuit in series (a) and as a single unit of Eormal Graph (b). Each CPE is built by complementing its own paths with its own evolution mode before being added to the resistance. As the linear circuit is not powered, the common flow is zero. 

Generally speaking, excitation of a medium by short laser pulses can be used to study dynamic properties of the medium over a very wide time range. Here, we have shown that nanosecond-pulse excitation can yield information about the dynamics of molecular reorientation on the -10-sec time scale, and thermal effect on the 10—l(X)-msec time scale. The power of this technique lies in the fact that a single 6-function-like laser pulse may induce a number of fundamental excitation modes of vastly different time constants. Consider, for example, molecular reorientation coupled with flow induct by a picosecond laser pulse in a liquid crystal. It can be shown that, aside from the thermal effect, the transient behavior will manifest itself with three characteristic time constants ... 

Chen XL, V amer SE, Rao AS, et al. Laminar flow induction of antioxidant response element-mediated genes in endothelial cells. A novel anti-inflammatory mechanism. J Biol Chem 2003 278 703-711. 

Flow induction is often called inertia, since this phenomena is a result of liquid inertia. For the reference volume in Fig. 2.4, the momentum balance holds ... 

In contrast to a direct injection of dc or ac currents in the sample to be tested, the induction of eddy currents by an external excitation coil generates a locally limited current distribution. Since no electrical connection to the sample is required, eddy current NDE is easier to use from a practical point of view, however, the choice of the optimum measurement parameters, like e.g. the excitation frequency, is more critical. Furthermore, the calculation of the current flow in the sample from the measured field distribution tends to be more difficult than in case of a direct current injection. A homogenous field distribution produced by e.g. direct current injection or a sheet inducer [1] allows one to estimate more easily the defect geometry. However, for the detection of technically relevant cracks, these methods do not seem to be easily applicable and sensitive enough, especially in the case of deep lying and small cracks. 

Exciting developments based on electromagnetic induction raced along from that time, giving us the sophisticated products our everyday lives depend on. During most of the period productive uses for eddy current technology were few and few people believed in it as a usefiil tool eddy currents caused power loss in electrical circuits and, due to the skin effect, currents flowed only in the outer surfaces of conductors when the user had paid for all the copper in the cable. The speedometer and the familiar household power meter are examples of everyday uses that we may tend to forget about. The brakes on some models of exercise bicycle are based on the same principle. 

A plasma of electrons, ions, and neutrals produced in gas flowing through concentric tubes is maintained and heated to 5000 to 8000 K by inductive coupling to a high (radio) frequency... 

Near the outlet from the torch, at the end of the concentric tubes, a radio high-frequency coil produces a rapidly oscillating electromagnetic field in the flowing gas. The applied high-frequency field couples inductively with the electric fields of the electrons and ions in the plasma, hence the name inductively coupled plasma or ICP. 

For inductively coupled plasma atomic emission spectroscopy (ICP-AES) the sample is normally in solution but may be a fine particulate solid or even a gas. If it is a solution, this is nebulized, resulting in a fine spray or aerosol, in flowing argon gas. The aerosol is introduced into a plasma torch, illustrated in Figure 3.21. 

Process-flow control and buffer-gas control have been discussed under Variable Nozzles and Buffer-Gas System respectively. Speed is usually self-controlled by a matching speed-sensitive load such as a compressor or a pump. If the load is an induction or svn-chronous generator feeding into a stable ac system, the system frequency fixes the speed. Otherwise, the speed can be controlled by a conventional governor. 

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