Basic Operating Principles

The basic operation principles of the AEBIL system can be translated into a sequence of elementary processing steps and summarized as follows (fjg. 1). 

There are a wide variety of coatiag appHcatioas processes ia use. The majority of these techniques are similar to those used ia other coatiags iadustries, and the same basic operating principles apply to these uses as to coatiag a photographic film or a coil of metal for a refrigerator. 

Electromagnetic These are quickly outdated but we discuss these relays briefly below to give an idea of the basic operating principles of such relays. The same principle of application is then transformed into a static or microprocessor-based relay... 

Pressure regulators are made in a variety of types. However, the basic operating principles of all regulators are similar to the one illustrated in Figure 40.21. 

Directional control valves may be classified in several ways. Some of the different ways are by the type of control, the number of ports in the valve housing, and the specific function that the valve performs. The most common method is by the type of valving element used in the construction of the valve. The most common types of valving elements are the ball, cone, sleeve, poppet, rotary spool, and sliding spool. The basic operating principles of the poppet, rotary spool, and sliding spool types are discussed in this text. 

Optical sensors rely on optical detection of a chemical species. Two basic operation principles are known for optically sensing chemical species intrinsic optical property of the analyte is utilized for its detection indicator lor label) based sensing is used when the analyte has no intrinsic optical property. For example, pH is measured optically by immobilizing a pH indicator on a solid support and observing changes in the absorption or fluorescence of the indicator as the pH of the sample varies with time1 20. 

As this chapter aims at explaining the basics, operational principles, advantages and pitfalls of vibrational spectroscopic sensors, some topics have been simplified or omitted altogether, especially when involving abstract theoretical or complex mathematical models. The same applies to methods having no direct impact on sensor applications. For a deeper introduction into theory, instrumentation and related experimental methods, comprehensive surveys can be found in any good textbook on vibrational spectroscopy or instrumental analytical chemistry1"4. 

D. Koutsouris, R. Guillet, J.C. Lelievre, M.T. Guilemin, B.R Beuzard, Y. Beuzard, and M. Bounard, Determination of erythrocyte transit times through micropores I - Basic operational principles. Biorheology 25, 763-772 (1988). 

The basic operating principle of enzyme use in sensors is simple an enzyme is immobilized inside a permeable layer, into which the substrate(s) diffuse and from which the product(s) can effuse. Any other species that participate in the reaction, such as buffers, must also diffuse in and out of the layer (see Fig. 2.9). Because of the combined mass transport and chemical reaction, this scheme is often referred to as the diffusion-reaction mechanism. 

FIG. 5 Basic operating principles of an electrodialysis process using (A) a couple of monopolar (anionic, a, and cationic, c) membranes or (B) a bipolar membrane. 

A diagram showing the basic operating principle of a triple quadrupole mass spectrometer is shown in figure 4. The sample enters the ion source from the column, via a suitable interface if necessary, and, in GC, is usually fragmented by either an electron impact or... 

Brief History and Basic Operating Principles of COIL 141... 

In Feature 25-7 we described the basic operating principles of the Michelson interferometer and the function of the Fourier transform to produce a frequency spectrum... 

Bauer (1921) developed the first high-temperature MCFC based on a molten (Na/K)2C03 electrolyte, immobilized in a MgO matrix.The MCFC in its present form was developed by G. H. J. Broers in 1951. Small laboratory cells were constructed using a non-sintered MgO + molten carbonate paste electrolyte. The durability of these cells was tested up to 6 mo. Common features of today s cells and the early Broers cells are the nickel-based electrodes with planar and bipolar construction and the alkali carbonate electrolyte in inert matrix filler. The basic operating principles are still the same and the cell is represented below. 

A basic operating principle of selective oxidation catalysis is the need to minimise the contact time between the selective oxidation product and the catalyst to prevent conversion of the product, typically, into oxides of carbon. Whereas this aspect of selective oxidation catalysis is well recognised, it has never been put on a quantitative basis, so that the ability of a particular active site to activate a target bond in a reactant in preference to a similar bond in the product. 

Skimmers are also classified according to their basic operating principles oleophilic surface skimmers weir skimmers suction skimmers or vacuum devices ... 

The control of charge flow by an electric quantity is a key issue of today s electronics. The concept to electrically specify the conductivity of a resistor by pure solid state effects was already proposed in 1928 by Julius Edgar Lilien-feld in Germany [1], The basic idea was to control the charge carrier density in a solid by an electric field, applied over a third electrode. However, there is no evidence for a practical realisation by Lilienfeld. The first report about a pure electrically controllable solid state device was the well know Germanium transistor from William Shockley, John Bardeen and Walter Brattain [2]. The new term transistor was later explained as a combination of the words transconductance and varistor . Meanwhile a broad variety of different transistor concepts exists, which, however, can be mainly subdivided in two basic operational principles ... 

---