Wafer-like

Figure 8 Optical image of an integrated LED/photodiode wafer like that shown schematically in Fig. 7b.

Some individual monographs already describe and require noncompendial equipment, such as Felodipine extended-release tablets, for dissolution testing.19 For example, one monograph describes a noncompendial probe inserted into Apparatus 2 as a wafer-like basket to the side of the paddle. Monographs with dissolution tests that require special equipment for low-dose products would most likely use a noncompendial apparatus in this manner. Use of noncompendial equipment should not be an obstacle as long as appropriate justification is provided and necessary qualification of the equipment is performed. 

An alternative system, manufactured as a wafer-like insoluble implant, has been developed (Ocusert). The system is preprogrammed to release pilocarpine at a constant rate of 20 or 40 / g/hr for a week to treat chronic glaucoma however, release from inserts may be incomplete and approximately 20% of all patients treated with the Ocusert lose the device without being aware of the loss. The device also presents problems including foreign-body sensation, expulsion from the eye, and difficulty in handling and insertion. An alternative to the advanced non-erodible systems is an erodible insert for placement in the cul-de-sac. 

Computer chips are everywhere. From pet-identification systems to laptop computers—any device that can be programmed contains a computer chip. Silicons abundance and ability as a semiconductor make it an ideal material for the production of computer chips. The first step in making a computer chip involves cutting pure silicon into wafer-like pieces. Silicon dioxide (Si02) is then cultivated on each wafer. Layers upon layers of silicon dioxide and other chemicals are used to create chips for specific functions. 

Figure 20-3 Dimensionless correlations between the effectiveness factor and the intrapellet Damkohler number for one-dimensional diffusion and nth-order irreversible chemical kinetics in porous catalysts with rectangular symmetry (i.e., n = 0, 1, 2). The quantity on the horizontal axis is A, not A. One-half of the thickness of these porous wafer-like catalysts is the characteristic length in the definition of A.

For a particular experiment in a packed catalytic tubular reactor, the chemical kinetics can be approximated by a zeroth-order rate law where the best value for the zeroth-order rate constant is calculated via the formalism on pages 459 and 460. At what value of the intrapeUet Damkohler number Aa. intrapellet does reactant A occupy 75% by volume of the catalyst if the porous pellets are (a) spherical, (b) long cylinders, and (c) wafer-like ... 

Lyophilized products are the result of a solution being removed of its water by freeze-drying. The resulting solid mass is called a cake. Typically, the cake sits in the bottom of the vial. Color typically is white or off-white. The consistency of the cake may range from solid and wafer-like to a light crystalline cake. The appearance of the cake would include color, a description of the texture (e.g., solid cake with crystalline nature), and the examination for any foreign particles. 

Maximum sample sizes that can be accommodated by SFM or STM vary. Current systems can scan a 8-inch Si wafer without cutting it. When industry calls for the capability to scan larger samples, the SPM manufacturers are likely to respond. 

A typical LIMS instrument accepts specimens up to 19 mm (0.75 in) in diameter and up to 6 mm in thickness. Custom designed instruments exist, with sample manipulation systems that accept much larger samples, up to a 6-in wafer. Although a flat sample is preferable and is easier to observe with the instrument s optical system, irregular samples are often analyzed. This is possible because ions are produced and extracted from pm-sized regions of the sample, without much influence from nearby topography. However, excessive sample relief is likely to result in reduced ion signal intensity. 

Bubble-shaped limif flame propagating up moves wifh a velocify defermined by buoyancy forces, like an air bubble in a column of wafer (in bofh cases, fhe Davies and Taylor formula [10] can be applied). 

Wafer Flour. Wafer flour is a type of biscuit flour with the same basic specification of low protein soft wheat flour with a low starch damage. Once again the required dough property is extensibility. The only differences are that if the protein is too low the wafer will be too soft to handle, and if the protein is too high the wafer will be too hard. The other important property is a resistance to gluten separation. Wafer flours are likely to be brown. 

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