Mark computers

HUl, Mark, Computer Power Protection, Broadcast Engineering, PRIMEDIA Intertec, Overland Park, KS, April 1987. 

T. A. Wassenaar and A. E. Mark,/. Comput. Chem., 27, 316 (2006). The Effect of Box Shape on the Dynamic Properties of Proteins Simulated Under Periodic Boundary Conditions. 

As the feed composition approaches a plait point, the rate of convergence of the calculation procedure is markedly reduced. Typically, 10 to 20 iterations are required, as shown in Cases 2 and 6 for ternary type-I systems. Very near a plait point, convergence can be extremely slow, requiring 50 iterations or more. ELIPS checks for these situations, terminates without a solution, and returns an error flag (ERR=7) to avoid unwarranted computational effort. This is not a significant disadvantage since liquid-liquid separations are not intentionally conducted near plait points. 

The program storage requirements will depend somewhat on the computer and FORTRAN compiler involved. The execution times can be corrected approximately to those for other computer systems by use of factors based upon bench-mark programs representative of floating point manipulations. For example, execution times on a CDC 6600 would be less by a factor of roughly 4 than those given in the tcible and on a CDC 7600 less by a factor of roughly 24. 

Deuflhard P, Hermans J, Leimkuhler B, Mark A E, Reich S and Skeel R D (ed) 1998 Computational Molecular Dynamics Challenges, Methods, Ideas vol 4 Lecture Notes in Computational Science and Engineering (Berlin Springer)... 

Van Gunsteren, W.F., Beutler, T.C., Praternali, F., King, P.M., Mark, A.E., Smith, P.E. Computation of free energy in practice Choice of approximations and accuracy limiting factors, in Computer Simulations of Biomolecular Systems, Vol 2, W.F. van Gunsteren, P.K. Weiner and A.J. Wilkinson, eds. Escom, Leiden (1993) 315-348. 

Mark, A.E. Free energy perturbation calculations. Encyclopaedia of Computational Chemistry, Wiley, New York, (1998) (in press). 

Gerber, P. R., Mark, A. E., van Gunsteren, W. F. An approximate but efficient method to calculate free energy trends by computer simulation Application to dihydrofolate reductase-inhibitor complexes. J. Comp. Aid. Mol. Desgn 7 (1993) 305-323... 

The salient comparisons are between the bars marked P3-Dk, our initial parallel PME implementation, and DP-4, the macroscopic multipole method with four levels of macroscopic boxes. Though it is difficult to create a completely fair comparison in terms of the relative accuracy of the potentials and forces as computed by the two methods, the parameters for these simulations were tuned to give comparable overall accuracy. PME is clearly... 

Schafer H, W F van Gunsterten and A E Mark 1999. Estimating Relative Free Energies from a Sing] Ensemble Hydration Free Energies, Journal of Computational Chemistry 20 1604-1617. 

The density determination may be carried out at the temperature of the laboratory. The liquid should stand for at least one hour and a thermometer placed either in the liquid (if practicable) or in its immediate vicinity. It is usually better to conduct the measurement at a temperature of 20° or 25° throughout this volume a standard temperature of 20° will be adopted. To determine the density of a liquid at 20°, a clean, corked test-tube containing about 5 ml. of toe liquid is immersed for about three-quarters of its length in a water thermostat at 20° for about 2 hours. An empty test-tube and a shallow beaker (e.g., a Baco beaker) are also supported in the thermostat so that only the rims protrude above the surface of the water the pycnometer is supported by its capillary arms on the rim of the test-tube, and the small crucible is placed in the beaker, which is covered with a clock glass. When the liquid has acquired the temperature of the thermostat, the small crucible is removed, charged with the liquid, the pycnometer rapidly filled and adjusted to the mark. With practice, the whole operation can be completed in about half a minute. The error introduced if the temperature of the laboratory differs by as much as 10° from that of the thermostat does not exceed 1 mg. if the temperature of the laboratory is adjusted so that it does not differ by more than 1-2° from 20°, the error is negligible. The weight of the empty pycnometer and also filled with distilled (preferably conductivity) water at 20° should also be determined. The density of the liquid can then be computed. 

Consumer Products. Laser-based products have emerged from the laboratories and become familiar products used by many millions of people in everyday circumstances. Examples include the supermarket scaimer, the laser printer, and the compact disk. The supermarket scanner has become a familiar fixture at the point of sale in stores. The beam from a laser is scaimed across the bar-code marking that identifies a product, and the pattern of varying reflected light intensity is detected and interpreted by a computer to identify the product. Then the information is printed on the sales sHp. The use of the scanner can speed checkout from places like supermarkets. The scanners have usually been helium—neon lasers, but visible semiconductor lasers may take an impact in this appHcation. 

Thermal printing usually involves passing materials over a full-width array of electronically controlled heaters (a thermal printhead). This marks thousands of spots simultaneously, so pages print relatively quickly. Image data to control the printhead usually come from computer systems. Black-and-white and full-color systems are both practical. Color is slower and more cosdy to purchase and use, primarily because this involves three or four successive printing operations, one for each color used. 

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