Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Short-circuiting solids

The principles behind this membrane technology originate from solid-state electrochemistry. Conventional electrochemical halfceU reactions can be written for chemical processes occurring on each respective membrane surface. Since the general chemistry under discussion here is thermodynamically downhill, one might view these devices as short-circuited solid oxide fuel cells (SOFCs), although the ceramics used for oxygen transport are often quite different. SOFCs most frequently use fluorite-based solid electrolytes - often yttria stabUized zirco-nia (YSZ) and sometimes ceria. In comparison, dense ceramics for membrane applications most often possess a perovskite-related lattice. The key fundamental... [Pg.186]

H. S. Spadl and D. W. White, Internally short-circuited solid oxygen-ion electrolyte cell, USPatent 3,630,979, filed January 2.1969. [Pg.50]

High-voltage contactor-type motor controls depend on power fuses for short-circuit protection. The fuses are coordinated with the overload relays to protect the motor circuit over the full range of fault conditions from overload conditions to solid maximum-current short circmts. [Pg.2490]

Shock compression of piezoelectric solids, even under short-circuit conditions, causes large electric fields of varying amplitude and polarity within the material. In the uncoupled approximation to the solution of the short-circuit... [Pg.75]

Figure 5.3 Schematic representation of the penetration profile for bulk, grain boundary, and dislocation diffusion in a polycrystalline solid. The initial part of the curve is bell shaped, and the part due to short-circuit diffusion is made up of linear segments. The insets show the distribution of the tracer in the sample. Figure 5.3 Schematic representation of the penetration profile for bulk, grain boundary, and dislocation diffusion in a polycrystalline solid. The initial part of the curve is bell shaped, and the part due to short-circuit diffusion is made up of linear segments. The insets show the distribution of the tracer in the sample.
Volume diffusion refers to the transport of atoms through the body of a solid. It is also called lattice or bulk diffusion. In amorphous or glassy solids and in cubic crystals, the speed of diffusion in all directions is the same and is said to be isotropic. In all other crystals, the rate of volume diffusion depends upon the direction taken and is anisotropic. Volume diffusion is usually much slower than short-circuit diffusion, which refers to diffusion along two- and three-dimensional imperfections in the material. [Pg.245]

Dendrite growth. Solid silver crystal needles grow on the cathode that can lead to arcing, short circuits, and membrane breach. [Pg.73]

Simple rolls, extending over the full width of the filter, can be so arranged that any irregularities or cracks in the cake are eliminated, and subsequent washing and drying is therefore applied to a uniform surface. Otherwise wash liquors and air tend to short circuit, or channel , the deposited solids. The cake compression system may also incorporate a... [Pg.419]

The major ions have two main escape routes from the ocean (1) incorporation into sediments or pore water and (2) ejection into the atmosphere as seasalt spray. This spray is caused by bursting bubbles that produce small particles, called aerosols, that range in diameter from 0.1 to 1000 pm. The annual production rate of seasalt aerosols is large, on the order of 5 x lO kg/y, but virtually all of it is quickly returned when the spray fells back onto the sea surfece. A small fraction (about 1%) is deposited on the coastal portions of land masses and carried back into the ocean by river runoff. As shown in Table 21.6, seasalts represent a significant fraction of dissolved solids in river runoff, especially for sodium and chloride. Due to the short timescale of this process, seasalt aerosol losses and inputs are considered by geochemists to be a short circuit in the crustal-ocean-atmosphere fectory. The solutes transported by this process are collectively referred to as the cyclic salts. ... [Pg.534]

Macroelectrodes with solid membranes contain homogeneous [142] or heterogeneous [25] membranes. The construction of an ISE of this type with an internal reference electrode is shown in fig. 4.1. For good functioning of an ISE it is necessary that the membrane be completely sealed in the electrode body, with no cracks leading to short-circuiting between the external and internal solutions. Cements based on Teflon, PVC or epoxy resin are used (170). [Pg.64]

If a film is heterogeneous, there may be parallel paths of sohd transformations (Figure 9-15). A transformation process can be short circuited by the presence of a parallel process, and this can greatly accelerate solid-state transformations. These can also be simplified by considering them as series and parallel processes, and, as long as they are linear (first order in concentrations), the electrical analogs can be used (Figure 9-15). [Pg.393]

Fig. 10 Simulated solar cell electrical behavior in the dark dotted traces) and under illumination (solid traces) comparing the effect of the saturation current parameter 7 on Foe- The black traces represent a device with /g x 10 that of the device represented by the red traces. The sharp inflection points in the semilog plots (upper panel) are the points where the current switches from positive to negative. Also illustrated in the linear representation (lower panel) are the short circuit current density, J c, and the maximum output power, Fmax. given by the product of current and voltage. The blue arrows represent the point at which the dark current and the current under illumination are equal in magnitude. The corresponding potential marked in blue on the voltage axis is Foe for the black trace... Fig. 10 Simulated solar cell electrical behavior in the dark dotted traces) and under illumination (solid traces) comparing the effect of the saturation current parameter 7 on Foe- The black traces represent a device with /g x 10 that of the device represented by the red traces. The sharp inflection points in the semilog plots (upper panel) are the points where the current switches from positive to negative. Also illustrated in the linear representation (lower panel) are the short circuit current density, J c, and the maximum output power, Fmax. given by the product of current and voltage. The blue arrows represent the point at which the dark current and the current under illumination are equal in magnitude. The corresponding potential marked in blue on the voltage axis is Foe for the black trace...
Conditions favoring efficient separation of flocculent metal precipitates in a basin include a low surface overflow rate, adequate depth, and inlet and outlet designs for a uniform velocity field with minimal short circuiting or stagnation. Solids separation is likely to limit the overall efficiency of metals removal in treatment, so pilot studies include batch and continuous flow settling column studies.18... [Pg.397]

A minimum residence time of 10 to 30 minutes should be provided to assure that surges do not upset the system and to provide for some coalescence. As discussed previously, potential benefits of providing more residence time probably will not be cost efficient beyond this point. Skimmers with large residence times require baffles to attempt to distribute flow and eliminate short-circuiting. Tracer studies have shown dial skniimei tanks, even those with carefully designed spreaders and baffles, exhibit poor flow behavior and short-circuiting This is probably due to density and temper-atuie differences, deposition of solids, corrosion of spreaders. etc... [Pg.171]

L. C. Correa da Silva and R.F. Mehl, Interface and marker movements in diffusion in solid solutions of metals, Trans. AIME, Vol. 191, pp. 155-173. Copyright by TMS (The Minerals, Metals, and Materials Society). Fig. 6.2 and Fig. 6.3 Reprinted, by permission, from A. Vignes and J.P. Sabatier, Ternary diffusion in Fe-Co-Ni alloys, Trans. AIME> Vol. 245, pp. 1795-1802. Copyright 1969 by TMS (The Minerals, Metals, and Materials Society). Fig. 6.2 Reprinted, by permission, from J.S. Kirkaldy, Diffusion in the Condensed State. Copyright 1987 The Institute of Metals (Maney Publishing). Fig. 9.1 Reprinted, by permission, from N.A. Gjostein, Short circuit diffusion, in Diffusion. Copyright 1973 by The American Society for Metals (ASM International). Fig. 9.2, Fig. B.6, and Fig. B.8 From Interfaces in Crystalline Materials by A.P. Sutton and R.W. Balluffi (1995). Reprinted by permission of Oxford University Press. Fig. 9.2 Reprinted, by permission, from I. Herbeuval and... [Pg.617]


See other pages where Short-circuiting solids is mentioned: [Pg.489]    [Pg.40]    [Pg.489]    [Pg.40]    [Pg.278]    [Pg.1092]    [Pg.1664]    [Pg.1687]    [Pg.20]    [Pg.148]    [Pg.181]    [Pg.317]    [Pg.84]    [Pg.597]    [Pg.221]    [Pg.223]    [Pg.252]    [Pg.254]    [Pg.85]    [Pg.709]    [Pg.749]    [Pg.242]    [Pg.147]    [Pg.207]    [Pg.40]    [Pg.27]    [Pg.219]    [Pg.231]    [Pg.567]    [Pg.338]    [Pg.238]    [Pg.59]    [Pg.62]    [Pg.284]    [Pg.475]    [Pg.323]    [Pg.129]   
See also in sourсe #XX -- [ Pg.15 ]




SEARCH



Short-circuiting

© 2024 chempedia.info