General-purpose developers formulas

The most widely used developer in the world, Kodak D-76, fells under the category of general-purpose developers. D-76 was formulated in 1927 byj. G. Capstaff of Kodak as a black and white movie film developer. However, not long afterwards better movie-film developing formulas were introduced and D-76 found use as a still-film developer. Eventually, it became the standard by which to judge all other developers. It was not that D-76 was the best developer ever formulated. It was more that a standard was needed and D-76 had the best all-around compromise of sharpness to grain with a full tonal range from black to white. 

When we speak of mathematical models for biology, we usually refer to formulae (such as the Hardy-Weinberg theorem, or the Lotka-Volterra equations) that effectively describe some features of living systems. In our case, embryonic development is not described by integrals and deconvolutions, and the formulae of the reconstruction algorithms cannot be a direct description of what happens in embryos. There is however another type of mathematical model. The formulae of energy, entropy and information, for example, apply to all natural processes, irrespective of their mechanisms, and at this more general level there could indeed be a link between reconstruction methods and embryonic development. For our purposes, in fact, what really matters are not the formulae per se, but... 

As will be seen in this discussion, the evolution of cleaners developed from simple soap powders to liquid formulations to products that are more specialized. All-purpose cleaners are the backbone of this development. Along with specialized formulas for specific cleaning problems, in some cases these products are augmented by specialized packaging. Generally, the packaging contributes more to the convenience of the product than the efficacy. 

To close this subsection, and for clarity purposes regarding the new PI calculations reported in this chapter, carried out with SCVJ, it is convenient to give the following information. The general formulas of the computational scheme developed by the author that are applied to compute k-space functions are... 

Probability distribution functions were first developed to measure the possibility of the occurrence of a specific event. Depending on the number of possible events, they can be discrete functions, when the number of possible events is discrete, or they can be classified as continuous functions. In the present contribution, only continuous distribution functions are studied. Probability distribution functions are defined for a reduced number of parameters and have simple formulae for calculating mean, mode, variance, etc. They have two main forms the probability density function (PDF) and the cumulative distribution function (CDF). The former is the most commonly used form of the probability distribution functions a very well known example of this type of function is the classical Gaussian bell (Evans et al, 1993). CDFs increase monotonically and generally describe the same behavior that is observed with distillation curves. Due to their simplicity, probability distribution functions are easily included in computer programs for modeling, optimization, and control purposes. 

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