Printing out processes

You must always believe that there is fertile soil for your ideas. If you lose hope then you will miss opportunities to plant a seed. 

The term printing out paper and the associated initials P.OP. were introduced in 1891 by the Ilford Company for their gelatin-chloride papers. The term has since been applied to any paper that requires ultraviolet light to form a complete image without the need for chemical development. In particular, it is used when referring to salted paper and related processes. 

The use of P.O.P. is a time-honored method for making inexpensive prints without a darkroom. The printing technique is simple the coated paper is contact-printed with a negative using the sun for a light source to make a visible image without development (a UV lamp, available from grocery and hardware stores, can also be used). 

There are several different types of P.O.P., salted paper, albumen, gelatino-chloride, and collodio-chloride, differing in the medium used to suspend the light-sensitive substance and if the sensitizer is applied in the salting solution (as in an emulsion) or as a second step. In the traditional salted paper process the silver is held by the fibers of the paper while albumen papers use egg whites as the binder. Gelatino-chloride papers suspend the silver in a gelatin layer and collodio-chloride uses a binder of cellulose nitrate. 

The basic light-sensitive substance used in all of these papers is silver chloride with an excess of silver nitrate. Once the image has been printed and toned, it is fixed, washed, dried, and preserved in much the same way as a silver print. Because the silver particles of printed out images are a much finer size than those of developed out prints, they are often more susceptible to deterioration. But with proper processing, they will stand the test of time as well as any process. Indeed, collodio-chloride is actually the most stable silver printing process because the nitrocellulose binder hermetically seals the silver from the harmful atmosphere that fades all silver base photographic prints. 

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In photography colloidal silver plays an important part, an instance being the image produced in the ordinary printing-out process. 

In a process similar to that described in the previous item, the stored data can be used to identify not just a series of compounds but specific ones. For example, any compound containing a chlorine atom is obvious from its mass spectrum, since natural chlorine occurs as two isotopes, Cl and Cl, in a ratio of. 3 1. Thus its mass spectrum will have two molecular ions separated by two mass units (35 -i- 2 = 37) in an abundance ratio of 3 1. It becomes a trivial exercise for the computer to print out only those scans in which two ions are found separated by two mass units in the abundance ratio of 3 1 (Figure 36.10). This selection of only certain ion masses is called selected ion recording (SIR) or, sometimes, selected ion monitoring (SIM, an unfortunate... 

As one might expect, computer data processing is an expensive adjunct to a liquid chromatograph and the more sophisticated reporting systems can be very expensive. An example of a computer print-out of... 

The purpose of interfacing instruments with computers is to enable raw analytical data to be collected as it is produced, then processed, stored and displayed or printed out. This may be accomplished as it is gathered, i.e. in real-time, or at some later time, i.e. post-run. Complete chromatograms or spectra can easily be stored in the main memory or RAM or transferred to disk. The immense storage capacity of mainframe computers can be used to provide large libraries of data (data banks) for future reference. 

Modem HPLC is adequately provided with complete data handling devices. Thousands of samples routinely analysed in Quality Assurance Laboratories in Pharmaceutical Industries/Bulk Drug Industries etc. are duly processed and the data stored in the computerised data-handling devices. Each stored data may be retrieved from the memory of the computerised device with the flick of a finger, as and when needed, in the form of print-out. 

Steward s algorithm, thus, can help locate errors in formulating a model of a process by identifying the set of equations that contains improperly specified design variables or parameters. The fortran program listed in Appendix A prints out the equation numbers in the subset that contains fewer variables than equations when an output set cannot be found. 

If the program is run on a Macintosh computer, then it will start processing immediately. However, it will obviously not complete the program until the last entry is made (the value of the extra column dispersion). The data is entered sequentially on request from statements given on the computer screen. On completion, the results are sent to the printer and an example of a computer print out is given below. ... 

Collodion printing-out paper was introduced by Obernelter of Munich in 1867 and was for many years the favorite printing process of the portrait... 

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