Programmable computer

Sixteen freely programmable computational formulae with assignment of the calculation parameters and units, mean-value calculations and arithmetic of one titration to another (via common variables) are available. Results can be calculated without any limitations. 

Robotics has been defined by Zenie [S] as an extension of programmable computers to do physical work, as well as processing data. Instrument systems using robotization and programmable computers are currently being used to improve productivity in scientific laboratories. Analysts need to identify samples, weigh, dilute, concentrate, extract, filter, evaporate, manipulate and analyse them. 

Because different people have slightly different opinions of what constitutes computational chemistry, it is useful to define its scope. Most published definitions embrace an overlapping set of ideas. Computational chemistry has been described as consisting of those aspects of chemical research that are expedited or rendered practical by computers (5). However, that scope is so broad that it would include most molecular science laboratories where modern instruments are built with programmed or programmable computers to collect and mathematically manipulate data. Such a definition is beyond the scope of this chapter. 

What Dirac did not—and perhaps could not—foresee is the development of computers. The first programmable computer was designed by Konrad... 

The first programmable computer, the Zl, is developed by Konrad Zuse Polystyrene is developed... 

Cu (5.1 min). Instrumental radioassay was performed with a similar nuclear counting system as for the airborne gunshot residues (Ref 17) described above with the addition of a programmable computer coupled to the multichannel analyzer for data processing. Using these procedures, it was possible to detect Ba levels above 2 x 10 g/cm and Sb levels above 1.5 x 10" g/cm of floor surface... 

Air sampling pumps may be self-metering, that is, they have a metering device built in. The pump may be operated by a programmable computer to set start/stop times and for intermittent, repeated, or continuum sampling (Figure 26.2). The one shown has an isothermal flow sensor. Fluctuations in temperature or pressure are automatically corrected for. The sampling data can be downloaded to the computer. 

Many differential equations occur for which no solution can be obtained with pencil and paper. A lot of these occur in the study of chemical reaction rates. With the use of programmable computers, it is now possible to obtain numerical approximations to the solutions of these equations to any desired degree of accuracy. 

The constants A. and fo can be incorporated into the controller as potentiometer adjustments, or in a program if a programmable computing type of controller is used. 

An alternative route to the total solvatochromic equation is by the method of multiple linear regression analysis (multiple parameter least squares correlation), which has become quite convenient with the recent availability of inexpensive programmable computers. In this one-step procedure, correlation of (9)max results with solvent ir and values leads directly to the equation. 

Numerical methods are a family of mathematical techniques for solving complicated problems approximately by the repetition of the elementary mathematical operations (+, —, x, H-). In the past, numerical solution of a PDE was extremely time consuming, requiring many man-hours of tedious calculation. However the utility of numerical methods has greatly increased since the advent of programmable computers. In the field of electrochemistry, two main techniques are used for simulation purposes the finite difference method and the finite element method, though the former is by far the more popular and will be used exclusively throughout this book. 

A programmable logic controller is a small programmable computer that gives a machine or device spedfic and limited directions. 

The simplicity and speed of SEC separations will ensure that SEC has widespread value in the low-molecular-mass area. The separating power of HPLC and GLC will always be greater, but the combination of techniques with different modes of separation will become more important as flowswitching systems with fully programmable computer-controlled operation become more freely available. Examples have already been highlighted for... 

Z3 programmable computer (Konrad Zuse) Zuse and his colleagues complete the first general-purpose, programmable computer, the Z3, in December. In 1950, Zuse wiU sell a Z4 computer—the only working computer in Europe. 

The first programmable computer, the Zl, is developed by Konrad Zuse Sunglasses become polarized by Ray Ban using a Polaroid filter developed by Edwin H. Land Polyst5frene is developed... 

Today such plots could be generated very quickly with a personal programmable computer. All of this is for just one point (wrist pin bearing at A) on the linkage of Fig. 2.11. Several other points are of interest in engine design. 

The 1950s marked the beginning of a new era - the time of programmable computers. Apparently, Just another tool for number crunching became available. In fact, however, the idea of programming made a revolution because it... 

When additional iterations produee only negligible changes in the orbital function and the energy, we say that the integral term provides a self-consistent energy of electron 1, or a self-consistent field. At this point, the iteration is stopped and we assume that our result resembles the best possible orbital. Hartree carried out this solution prior to the existence of programmable computers. 

We have discussed the diffraction of X-rays as though each atom in the crystal lattice were a point from which the X-rays are scattered. In fact, the principal scattering is from electrons, which are distributed over the entire unit cell. The scattering from the different parts of the unit cell interferes constructively and destructively in ways that are determined by the electron density in the unit cell. Analysis of the relative intensities of the different diffracted beams allows in some cases for the reconstruction of the electron density as a function of position in the unit cell. This is a complicated process, which we do not describe. The first such structure determinations were done before the advent of programmable computers, with many hours of hand calculation. Present-day calculations are done automatically by computer programs, using intensity data taken with automated computer-driven diffractometers. 

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