Force computer programs

Empirical conformational energy program for peptides (ECEPP) is the name of both a computer program and the force field implemented in that program. This is one of the earlier peptide force fields that has seen less use with the introduction of improved methods. It uses three valence terms that are fixed, a van der Waals term, and an electrostatic term. 

For two- and three-layered cross-ply and angle-ply laminates of E-glass-epoxy, Tsai [4-10] tabulates all the stiffnesses, inverse stiffnesses, thermal forces and moments, etc. Results are obtained for various cross-ply ratios and lamination angles, as appropriate, from a short computer program that could be used for other materials. 

For complex offshore structures or where foundations may be critical, finite-element analysis computer programs with dynamic simulation capability erm be used to evaluate foundation natural frequency and the forced vibration response. 

Molecular mechanics simulations use the laws of classical physics to predict the structures and properties of molecules. Molecular mechanics methods are available in many computer programs, including MM3, HyperChem, Quanta, Sybyl, and Alchemy. There are many different molecular mechanics methods. Each one is characterized by its particular/orce eW. A force field has these components ... 

As can be seen, conditions in a flowing reactor, even the simplest such as a tube, may be far from the thermodynamic equilibrium conditions predicted by the equilibrium computer programs. However, in the diffusion controlled range, it is possible to use as the driving force for diffusion, the difference between an assumed equi-... 

Most other major industrial countries have adopted similar rules, and in 2002 the World Intellectual Property Organisation (WIPO) Copyright Treaty of 1996 [25] entered into force for a number of countries, including Japan and the United States. Signatories to this treaty must ensure that computer programs are protected as literary works [26]. 

This relation is useful because it effectively removes the requirement that Mj be known for one of the basis species. Instead of setting this value directly, it can be determined by balance from the mole numbers of the other basis species. When charged species appear in the basis, in fact, it is customary for equilibrium models to force charge balance by adjusting Mi for a component chosen either by the modeler or the computer program. 

The use of molecular mechanics calculations has become common practice in chemical research since the early 80s, when general-purpose force fields, incorporated into user-oriented computer programs, started to appear (Figure 1). As noted above, the most popular and extensively used force fields are undoubtedly those developed by Allinger s group, namely MMI (early 70s), MM2 (1977-) and, more recently, MM3 (1988-). 

In a reversed-phase liquid chromatography system, if the hydrogen-bonding and Coulombic forces are negligible, the retention of molecules depends upon their size, and the presence of n electrons enhances the selectivity. The molecular size, i.e. the van der Waals volume, can be calculated by hand, by Bondi s method,29 or by certain computer programs. 

GF method calculations are simplified by the systematic behavior of the G matrix elements (Decius 1948). MUBFF calculations, however, are somewhat complicated by the force constants representing interactions between non-bonded atoms— these can be tedious to express in terms of internal coordinates. Computer programs have been written to partially automate calculations, thereby reducing the necessary effort and minimizing opportunities for errors (e.g., Schachtschneider 1964 Gale and Rohl 2003). 

The first analytical effort was MA VIS, a computer program which modelled all the interactions present in a valve and calculated the forces and velocities involved. The data used to confirm MAVIS were some preliminary data acquired in 1968 on a valve design of that era. 

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