Heating phase

The heating phase is used to take a molecular system smoothly from lower tern peratiires, indicative of a static initial (possibly optim i/ed ) structure, to th e temperature T at which it is desired to perform the molecular dynamics simulation. The run phase then consLitn tes a sim n lation at tern peratnre T. If th e heating h as been done carefully, it may be possible to skip the equilibration phase... 

In the heating phase (assuming i j is non-zero), the velocities are periodically rescaled to change the system temperature from the initial tern perature T to the simulation temperature T2 in incrc-m eiiis of th e temperature step AT. Th e h eaiin g period for rescaling the velocities, P, is defined by ... 

During the press operation, which is actually a form of compression mol ding, the resin-treated laminate pHes are heated under pressure and the resins cured. The initial heating phases cause the resin to melt and flow into voids in the reinforcing ply and bond the individual pHes together. The appHed heat simultaneously causes the resin to polymerize and eventually to cross-link or gel. Therefore, resin viscosity reaches a minimum during the press cycle. This is the point at which the curing process becomes dominant over the melt flow process. Dynamic mechanical and dielectric analyses (11) are excellent tools for study of this behavior. 

The heat input per unit mass of adsorbent in the isosteric heating phase when the concentration is... 

For example, the difference between the monoclinic CaC2 phases is the presence of only one type of acetylide ion in phase II and two distinct C2 species in phase III, as concluded from their crystal structures and from C-NMR studies (Fig. 8.3) [8]. The transformation between phases II and III is induced by heating phase II above 150°C until the metastable phase. III, is formed. Phase III remains stable even when being cooled down to room temperature. However, when the metastable phase III is ground in a mortar at room temperature, it transforms back into phase II. 

Oxidation of the durene derivative to benzenehexacarboxylic acid (mellitic acid) in an autoclave is normally effected in stages, initially by heating at 80-104°C with the vent open to allow escape of the evolved gases. Subsequent heating to a higher temperature with the vent closed completes the reaction. On one occasion omission of the first vented heating phase led to explosive rupture of the autoclave at 80° C. 

Fig. 2.9 Microwave heating (single-mode reactor) of ethanol under open-vessel conditions. Initially, the temperature rises during the heating phase (AB), above the normal boiling point of ethanol (78 °C), to a point C at which the solvent bumps and starts to boil at the vapor/liquid interface. At this point, the...

Standard burials are acceptable when contamination levels are low enough to allow bodies to be handled without wearing additional protective equipment. Cremation may be required if remains cannot be completely decontaminated. Although arsenic vesicant agents are destroyed at the operating temperature of a commercial crematorium (i.e., above 1000°F), the initial heating phase may volatilize some of the agents and allow vapors to escape. Additionally, combustion will produce toxic and potentially volatile arsenic oxides. 

A. HEATING PHASE. During heating, a total continuity equation and an energy equation for the steam vapor may be needed, plus an equation of state for the steam. 

The heating phase for melting the powder is crucial to the final surface quality. The heat-up should be fast but uniform. The ovens used to melt the powder on the part can be convection, infrared, or combination (hybrid) ovens. Infrared (IR) or combination (IR/convection) ovens are most widely... 

The progress of the various steps (the temperature increase under constant pressure during the heating phase, or the pressure decrease at a constant temperature during the esterification and the topping period) is checked at specific times in order to ascertain the development up to that point. 

Heat Phase I water to 80C. Blend in Witconate AOS with good agitation. When this is blended completely, add the remaining Phase I ingredients, melting them first before adding. Cool to 45C and add Phase II, in the order listed. Cool to 35C and adjust pH = 7.0-7.7 with citric acid. Add sodium chloride to desired viscosity. 

The interesting features of the photo-heating phase transition are that irradiation causes the originally continuous transition to become discontinuous and the transition temperature to be lowered. These can be explained using the Flory-Huggins equation of state ... 

It is common practice to stop the stirrer for sampling. Nevertheless, it should be restarted immediately afterwards. At least during the heating phase, the operator should have noticed the stirrer was inactive. 

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