Slab method

Describe the slab method of clay object construction. 

The slab method is the best choice for forming rectilinear pieces. 

Slab Method Roll and Cut. In the slab method, the clay is rolled into a flat sheet using a rolling pin, the thickness being regulated with guide sticks. Pieces are cut from the sheet and assembled. (See Figure 4.15.)... 

Slab PAGE allows simultaneous electrophoresis of a number of samples to be performed under identical conditions. Slab PAGE has a higher resolving power than column PAGE, and is often used for molecular weight and purity determinations. Because the slab is relatively thin, heat dissipation is more efficient in a slab than in a column. The slab can be used vertically or horizontally, but in practice, the horizontal slab method is used only when the monomer plus cross-linker concentrations are low and the gel is soft. A slab gel is prepared in the same way as a column gel, except that a comb, or slot-former, is inserted before polymerization. Removal of the comb after the gel has set leaves sample wells that are separated from each other by continuous strips of gel. 

The slab methods suffer from two disadvantages. They are computationally intensive, and the density of states obtained is a discrete, rather than a continuous, spectrum. One method which... 

The last approach is the periodic slab method. In this approach one defines a unit cell which comprises a large enough surface ensemble. Periodic boundary conditions are then used to expand the cell in the x, y, and/or z directions, thus providing the electronic structure for linear, slab (surface), and bulk materials, respectively. 

I. Machida, T. Saeki, K. Yoshikawa, and S. Nakai, Improved technique for growth-inhibition test by agar-slab method for detection of chemical mutagens in Saccharomyces cereviciae, Mutat. Res. 31,1 (1975). 

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