UNIVAC computer

Computations were carried out on the IBM 1620 and the Univac 1108 computers. Programs (Fortran) were prepared for the cases where n, the number of components in addition to the central intermediate, is 2, 3, 4, and 5. These programs are available on request from the authors. 

Calculations for the extractive distillation of aqueous ethanol mixtures containing 85.64% m ethanol have been carried out with the aid of a UNIVAC 1108 computer. The computer program calculates all phase equilibria and tray-to-tray material and heat balances for each component... 

We thank R. M. Barrer for his valuable comments and P. H. Emmett for his helpful discussions. We are indebted to the Analytical Research Department for chemical analyses. Computer programs used were NRC-12 Fourier program (1) and POWOW (4) least squares program. Computations were done on the Univac 1108 computer at the University of Maryland. 

One of the authors (F. Kaser) is grateful to DFG and the Sonder-forschungsbereich 80 for financial support. The computations were performed on the UNIVAC 1108 computer of the University of Karlsruhe. 

Then T is calculated from Eq. (m) and subsequently r T). Next the integral equation is solved, starting with the assumed Pm as first approximation for the profile inside the particle. The (pm ), obtained from Eqs. (o) is compared with the assumed value. If they do not correspond the procedure described here is repeated. If they do, pco, and T/ are recalculated so that everything is known at z = 0. Then using the Runge-Kutta routine, the values of Pm, pco2> and T at the end of the first increment Az are calculated and from this F,. Then the values of p, Po)t , and so on have to be computed in the way outlined above. Cappelli et aL performed the simulation on a Univac 1108 computer. One such computation... 

The results obtained from Listing 10.14 are for a total of 8000 time points. If this number is increased by a factor of 4 to 32000 time points the h-2h estimated error would be expected to decrease by a faetor of 16 whieh would make it quite small on the scale of the solution. This is left as an exereise for the reader to execute the code in Listing 10.14 with various numbers of time steps and observe flie effect on the estimated error of the solution. For a linear step distribution, little improvement in the solution would be expeeted after a total number of 32000 steps. With modem desk top computers, fliis calculation can be performed in a few seconds even with the interpretative language used in fliis work. Interestingly in research for this work, a reference was found to such a calculation in 1974 using a UNIVAC 1108 computer and performing three simulations from 0 to 10 with a step size of 0.001 (total of 10,000 points per calculation) that was performed in a little less than 30 min Just shows how fortunate we are today with... 

Va, 22203. As with IBM, the UNIVAC Computers are of different type s for Government... 

The digital output can be transmitted to a Hewlett Packard digital printer. A 1205-060 interface makes possible real time or memory mode recording on a rapid option Kennedy magnetic tape recorder for subsequent readout in a Univac computer or a minicomputer. 

With their strength tied to available computer speed, simulations continue to become a more powerful tool. A letter to the Journal of Chemical Physics by B. J. Alder and T. E. Wainwright in 1957 was the first work that reported results from molecular dynamics simulations. The Lawrence Radiation Laboratory scientists studied two different sized systems with 32 and 108 hard spheres. They modeled bulk fluid phases using periodic boundary conditions. In the paper they mention that they counted 7000 and 2000 particle collisions for 32 and 108 particle systems, respectively. This required one hour on a UNIVAC computer. Incidentally, this was the fifth such commercial computer delivered out of the 46 ever produced. The computer cost around 200 000 in 1952 and each of ten memory units held 100 words or bytes. Nowadays, a 300 personal computer with a memory of approximately 500000000 bytes can complete this simulation in less than 1 second. And Moore s empirical law that computer power doubles every 18 months still holds. 

The actual program used at NPL was written by N.P. Barry on the basis of the methods described previously. It is written in FORTRAN and has been implemented on IBM 370 and UNIVAC 1100 computers operated by computer bureaux. Vector algebra is employed. The reason why the graphs have double boundaries is that the calculation can be performed for boundaries of any convex polygon of up to 30 sides. This permits calculations to be restricted to the stability range of particular components, for example, that of water or chloride. 

Though unstable, the computer industry grew rapidly during the 1960s, and the final piece of the computer development puzzle, time-sharing, came about late in the decade. Efforts to develop and commercialize time-shared computers were led by General Electric s computer department, which was quickly overtaken by IBM, UNIVAC, and Digital Equipment Corp. 

The "PS79" program is currently in operation on several major computers - IBM 370 series, UNIVAC 1100 series, CDC 6000 series, and DEC-10 - and in the majority of cases refinement runs can be completed within the fast turnaround job limitations of individual shops. Usually, only the final x-ray runs will demand more time. 

Digital computers were first built at Harvard University (Aiken s53 Automatic Sequence Controlled Calculator, Mark I, 1939-1944) and at the University of Pennsylvania by Eckert54 and Mauchly55 (Electronic Numerical Integrator and Calculator, ENIAC, 1946) they used vacuum tubes instead of the cumbersome and slow mechanical switches. ENIAC morphed into an Eckert-Mauchly design of BINAC, which was sold to Remington Rand and became Univac I. 

These data were then reduced to straight-line functions on a Univac 1105 computer by the method of least squares. Equations 1 and 2 were used to determine the density of liquid ozone-fluorine mixtures at the two temperatures investigated. 

Figure 6.2. Photo of the room-sized UNIVAC 1 computer system that was introduced in the late 1950sj8]...

Individual atoms seen for the first time using the field ion microscope The first commercial production of acrylic fibers by du Pont The computer UNIVAC 1 is developed... 

Table 2. Typical computing times (CPU minutes) on IBM 370/158 (IBM 370/158 s C DC 6400 csi Univac 1110) for the Nj—interaction potential surface ...

IBM 700 series. Remington Rand Univac series digital computer (J), General Electric 250 (27)... 

Molecular Manipulation and Superimposition. To facilitate molecular comparisons, a variety of computer graphic techniques are available for three-dimensional manipulation and display of the stored structures in the library file (12,13). In our laboratory lateral stereo pair views of either single line or ball and stick models are displayed on a Tektronix 4014 graphics terminal linked to a Univac 1100/42 computer. 

Users with in-house computers may lease from the JCPDS [14.3] magnetic tapes on which are stored all the diffraction data of the current card file. Johnson-Vand search programs for use on IBM 360/370, Univac 1100 series, or CDC 6000/7000 series computers are supplied with the tapes. 

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