Speed-up

Most rigs are now fitted with a system whereby the drill string is rotated by a drive mechanism in the mast rather than by the rotary table at rig floor level. Thus 90 foot sections can be drilled before connections need to be made, and the drill string can be rotated while pulling out of the hole in 90 foot sections. This improved system, which speeds up the operation and allows better reaming of the hole is known as top drive. 

One production line of a paper mill consists according the size and the quality of the produced paper sometimes from more than 50 steam drums to dry and flatten the produced paper. These drums (cylinders with flat bottoms, see figure 1) will be used with a steam pressure up to 500 kPa (5 bar) and additionally with a rotation speed up 1200 m.min the material is mainly grey cast iron (with lamellar graphite). The diameters can reach up to 2.2 m and the cylindrical lengths up to 10 m. For the specific flattening drums the cyhndrical diameters can be up to 5 m and more. 

To speed up the process of attainment of the temperature steady value one can use special operations calculation without a kiln rotation, using large time intervals and calculation in two-dimensional R-tp geometry without regard for heat and mass transfer along an axis The program for realization of discussed simulation algorithms enables to calculate temperature in cells, a total number of which can not exceed 130 thousands A circular kiln structure can contain up to three layers. 

After these improvements the system was able to measure at drawing speeds up to 500 m/min on one channel. At higher velocities vibrations spoiled the measurements. The water remaining on the tube after the measuring chamber was removed using a pressured air system. 

The biased-sampling approach may be considerably generalized, to allow the construction of MC moves step-by-step, with each step depending on the success or failure of the last. Such a procedure is biased, but it is then possible to correct for the bias (by considering the possible reverse moves). The technique has dramatically speeded up polymer simulations, and is capable of wider application. 

An important aspect of biological transport is that nature makes extensive use of the reduction of dimensionality to speed up search and discovery (SD) (see also section C2.14.6.2). SD is enonnously enlranced upon moving from tliree to two or one dimensions, because the spatial extent to be explored is drastically reduced. Affinity follows kinetics in being enlranced upon moving from tliree dimensions to two dimensions 1791. 

The first term represents the forces due to the electrostatic field, the second describes forces that occur at the boundary between solute and solvent regime due to the change of dielectric constant, and the third term describes ionic forces due to the tendency of the ions in solution to move into regions of lower dielectric. Applications of the so-called PBSD method on small model systems and for the interaction of a stretch of DNA with a protein model have been discussed recently ([Elcock et al. 1997]). This simulation technique guarantees equilibrated solvent at each state of the simulation and may therefore avoid some of the problems mentioned in the previous section. Due to the smaller number of particles, the method may also speed up simulations potentially. Still, to be able to simulate long time scale protein motion, the method might ideally be combined with non-equilibrium techniques to enforce conformational transitions. 

Abstract. Molecular dynamics (MD) simulations of proteins provide descriptions of atomic motions, which allow to relate observable properties of proteins to microscopic processes. Unfortunately, such MD simulations require an enormous amount of computer time and, therefore, are limited to time scales of nanoseconds. We describe first a fast multiple time step structure adapted multipole method (FA-MUSAMM) to speed up the evaluation of the computationally most demanding Coulomb interactions in solvated protein models, secondly an application of this method aiming at a microscopic understanding of single molecule atomic force microscopy experiments, and, thirdly, a new method to predict slow conformational motions at microsecond time scales. 

In the next section we will illustrate how to further speed up the SAMM... 

For large systems comprising 36,000 atoms FAMUSAMM performs four times faster than SAMM and as fast as a cut-off scheme with a 10 A cut-off distance while completely avoiding truncation artifacts. Here, the speed-up with respect to SAMM is essentially achieved by the multiple-time-step extrapolation of local Taylor expansions in the outer distance classes. For this system FAMUSAMM executes by a factor of 60 faster than explicit evaluation of the Coulomb sum. The subsequent Section describes, as a sample application of FAMUSAMM, the study of a ligand-receptor unbinding process. 

Notes and Comments. Further improvements in efficiency were achieved by implementing the method on computers with highly parallel architecture. SISM performs in parallel as LFV which means the speed up Is gained due to longer time stop wliidi cun be u.sed by SISM [20]. 

In particular, in silico methods are expected to speed up the drug discovery process, to provide a quicker and cheaper alternative to in vitro tests, and to reduce the number of compounds with unfavorable pharmacological properties at an early stage of drug development. Bad ADMET profiles are a reason for attrition of new drug candidates during the development process [9, 10]. The major reasons for attrition of new drugs are ... 

Choose th e DIIS SCF con vergen ce accelerator to poten tially speed up SCF eon vergen ee. DIIS often reduees the number of iteration s required to reach a con vergen ec limit. However, it takes memory to store the Fock rnalriees from th c previous iteration s an d this option may increase th e com pu tation a I time for individual iteration s because th e Fock m atrix h as to be calcu la ted as a lin car corn -biriation of the current Fock matrix and Fock matrices from previous iteration s. 

Energy minimisation and normal mode analysis have an important role to play in the study of the solid state. Algorithms similar to those discussed above are employed but an extra feature of such systems, at least when they form a perfect lattice, is that it is can be possible to exploit the space group symmetry of the lattice to speed up the calculations. It is also important to properly take the interactions with atoms in neighbouring cells into account. 

Set-up for vac-distillation. She wraps the flask and still head with aluminum foil to act as an insulator. Speeds up the distillation process. Begin to heat the DCM extraction slowly under maximum... 

The term chiral recognition refers to a process m which some chiral receptor or reagent interacts selectively with one of the enantiomers of a chiral molecule Very high levels of chiral recognition are common m biological processes (—) Nicotine for exam pie IS much more toxic than (+) nicotine and (+) adrenaline is more active than (—) adrenaline m constricting blood vessels (—) Thyroxine an ammo acid of the thyroid gland that speeds up metabolism is one of the most widely used of all prescription... 

Some systems converge poorly, particularly those with multiple bonds or weak interactions between open-shell systems. HyperChem includes two convergence accelerators. One is the default convergence accelerator, effective in speeding up normally... 

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