Print intensification

Larger emissions or consumption of scarce resource could occur elsewhere in the lifecycle via the large-scale introduction of process intensification. For example, the proposed printed circuit board reactors could in the manufacturing step cause large emissions of VOCs from cleaning chemicals. And the demolition phase could... 

A dry, untoned print that looks perfect might be too dark after iron blue-toning because of the intensification effect. If in doubt, make a slightly lighter print with clear highlights. 

Sepia Intensification Bleach and redevelop sepia toners, such as Ansco 221 Sepia Toner or Kodak T-7a Sulfide Sepia Toner, are more effective than chromium intensifier and will provide maximum archival protection for your negatives. The reason for the latter is explained more fully in Chapter 10,Toning Prints Protective Toners, though simply put, converting an image from silver metal to silver sulfide makes the image as permanent as it possibly can be. 

Intensification is also a good technique for paper negatives as it will strengthen the paper transparency, or paper negative, for contact printing on enlarging papers. 

Chromium Intensification for Prints The technique is to bleach the print and then redevelop it in a non-staining developer, just as you would for a negative. Slow chlorobromide and chloride papers respond best to this technique. Cold-toned and bromide papers don t respond as well to chromium intensification, but changes will occur. If in doubt, give it a try. 

Selenium Intensification Selenium toning causes a slight increase in print density, a form of intensification that gives most prints a richer appearance. The increased density is more noticeable in the shadow areas. If you want to use selenium toning on prints for longevity without noticeable intensification, compensate by reducing the development time of the print by about 10%. 

The depth of the blue toning will vary with the quality of the prints toned. Some intensification of the print usually occurs in toning consequently, prints should be slightly lighter than the density desired in the final toned print. 

The washing time can be shortened by at least half by placing the print for 10 to 20 seconds in a 3% solution of sodium carbonate. If this method is used, handle the prints carefully. This is because carbonate considerably softens the emulsion. Redevelop the image with any non-staining developer (e.g., Kodak D-72) for 2 to 5 minutes. The print should be washed for about Vi hour. Always use a fresh developer for print intensification. 

NOTE 1 Prints for intensification should not be hardened. If they have been hardened, use Dehardener. 

The UK pioneered advanced compact heat exchangers, such as the printed circuit (PCHEs) and Marbond units in the process industries, and the success of initiatives in this area - which led to the emphasis of enhancement and PI - was seen by many as the first official recognition of process intensification technologies as major tools in aiding more efficient use of energy. This has now extended internationally and to reactors (Haugwitz et al., 2007), as illustrated in Chapter 5. 

It is highly relevant to note that some of the most compact intensified process plants are fabricated nsing methodologies developed within the electronics sector - micro-technology and MEMS, (nficro-electro-mechanical systems) are synonymous with modem manufacturing technology and also with intensification. The Printed Circuit Heat Exchanger (Chapter 4), as its name implies, bears not a small relationship to electronics. 

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