Critical-voltage technique

In such models, the bonding is considered to be partially ionic with a charge transfer from A1 to the Ni 3d valence band. To explain the properties of /J NiAl at a more sophisticated level, Fox and Tabernor (1991) measured four low-angle structure factors by the HEED critical-voltage technique. The deformation density based on these four reflections shows a depletion of density around both the Ni and A1 atoms, and a buildup of about 0.13 eA-3 along the [111] direction halfway between Ni and A1 nearest neighbors. 

The chronoamperometric technique illustrates the principle that analytically useful current responses depend critically on the efficiency of analyte mass transport within the solution. The analyte mass transport in turn depends on the efficiency with which an appHed voltage can maintain the surface concentrations of oxidized and reduced species at values specified by the Nemst equation. It is generally the case in chronoamperometry that the bulk concentration of one of the species is zero whereas the surface concentration of the other species is forced to zero by the appHed potential, but this is not always so. 

In a V/f control generally, only the frequency is varied to obtain the required speed control. Based on this frequency, the switching logistics of the inverter control circuit control the inverter s output voltage using the PWM technique to maintain the same ratio of V/f. A W/control is, however, not suitable at lower speeds. Their application is limited to fan, pump and compressor-type loads only, where speed regulation need not be accurate, and their low-spccd performance or transient response is not critical and they are also not required to operate at very low speeds. They arc primarily used for soft starts and to conserve energy... 

Critical current measurements have been made with a variety of techniques. The indirect technique, that of obtaining the critical current from the magnetization response is discussed in Chapter 18. Direct transport measurements, using attached current and voltage leads, and indirect measurements requiring macroscopic current circulation will be discussed. Critical currents are desired as a function of both temperature and applied magnetic field since a variety of theories discuss the functional relationship. And applications may require either or both of these data. 

A tissue section cut from a frozen specimen in this situation, ice is the supporting matrix. See Yamada, E. and Watanabe, H., High voltage electron microscopy of critical-point dried cryosection, J. Electron Microsc. 26 (SuppL), 339-342, 1977 Maddox, P.H., Tay, S.K., and Jenkins, D., A new fixed cryosection technique for the simultaneous immuuocytochem-ical demoustratiou of T6 and SlOO antigens, Histochem. J. 19, 35-38,... 

Oveidoped superconducting Nd2.xCexCu04,s (NCCO) (x = 0.17) thin films have been fabricated by using a planar dc sputtering technique. Current-voltage (I-V) characteristics and critical current densities Jc have been measured as function of the perpendicular magnetic field at different temperatures. Films with critical temperatures around 10 K and critical current densities above 10 A/m at T = 2.1 K have been obtained. 

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