Artificial flat plates

As with previous methods, artificially layered deposits may be obtained from a single chemical solution using a specially designed cell, for instance, with adjustable anode-cathode gap (see Fig. 17.3). This two-compartment cell may be constructed from Lucite with deposition conducted in one compartment, and KC1 solution placed in the other. A calomel reference electrode immersed in this KC1 solution should be coupled to the flat-plate cathode by a salt bridge, ending in a capillary on the deposition side. The specimen electrode is fixed, and the counter-electrode is movable using, say, a micrometer. Electrodeposition is best conducted under quiescent conditions. 

In stud dng stability of flows, it is convenient to pose the problem either as a temporal or as a spatial instability problem. While it is numerically expedient to take a temporal approach, many practical flows are known to follow spatial route. For example in lab experiments for external wall-bounded flows, it is noted that the disturbances grow in space as they travel downstream. This was established unambiguously through the experiments of Schubauer Skramstad (1947) for flat plate boundary layer and is an excellent example of spatial instability problems. However, there are many flows where the instability grows both in space and time. These type of problems to identify whether the flow suffers temporal and/ or spatial instability arise in linear stability analysis. Flow instability studied following descriptions of two independent routes, is an artificial way of treating general instability problems. 

You saw how the equations governing energy transfer, mass transfer, and fluid flow were similar, and examples were given for one-drmensional problems. Examples included heat conduction, both steady and transient, reaction and diffusion in a catalyst pellet, flow in pipes and between flat plates of Newtonian or non-Newtonian fluids. The last two examples illustrated an adsorption column, in one case with a linear isotherm and slow mass transfer and in the other case with a nonlinear isotherm and fast mass transfer. Specific techniques you demonstrated included parametric solutions when the solution was desired for several values of one parameter, and the use of artificial diffusion to smooth time-dependent solutions which had steep fronts and large gradients. 

Artificial collectors (e.g. buckets, funnels, Petri dishes, filter papers, and flat plates) set up in the field and exposed for knowi time periods. -Rainshields occasionally used to distinguish between wet and dry deposition. 

Orifice piates are flat plates with holes that are typically smaller than the inside diameter of the pipe. The intent is to place the device between two flanges and restrict flow so that an artificial high- and low-pressure zone is created on each side of the orifice. A transmitter is used to calculate the differential and calculate a flow rate. The venturi flow nozzle uses the same principle as... 

Develop the material balance equations that describe the steady-state axial concentration profiles in a flat plate membrane dialyzer used as an artificial kidney. A schematic is shown below ... 

Another is the combination of the same femoral component and conductive silicone rubber tibial flat specimen( E = 9.1 MPa, 3 mm in thickness) supported by acrylic flat plate. The latter model corresponds to the knee prosthesis with compliant artificial cartilage. 

We can also seek predictions based on solid-fluid interfaces, although these have less practical value. We will also consider mass transfer within a short tube, which is important for artificial kidneys and blood oxygenators and mass transfer on a flat plate, which is important because of strong parallels with heat transfer. However, while these solid-fluid interfaces are often detailed pedagogically, they are less significant than the results for fluid fluid interfaces. 

Figure 2.26 Heat transfer characteristics for stable nucleate boiling of sodium on a polished, flat, horizontal, nickel plate containing a single cylindrical artificial cavity. (From Deane Rohsenow, 1969. Copyright 1969 by American Society of Mechanical Engineers, New York. Reprinted with permission.)...

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