Condensed material

Trunin R F 1998 Shock Compression of Condensed Materials (Cambridge Cambridge University Press)... 

Vacuum Outgassing and Permeability. Under vacuum, modified ethylene—tetrafluoroethylene copolymers give off Htde gas at elevated temperatures. The loss rate is about one-tenth of the acceptable maximum rates for spacecraft uses. Exposing 750-pm specimens for 24 h at 149°C to a high vacuum results ia a maximum weight loss of 0.12% volatile condensible material is less than 0.02%. 

Drawdown from the die to nip is typically ca 10%. Sheet extmsion requires that the resin be of high melt viscosity to prevent excessive sag of the melt between the die and the nip. The melt should reach the nip before touching any other part of the middle roU to prevent uncontrolled cooling of the resin. The appearance of the lower surface of the sheet is deterrnined by the middle roU, ie, its poHsh, surface temperature, and freedom from condensed materials. The upper surface is cooled by air and has a more glossy appearance. Neither the top roU nor the bottom roU greatly affect the appearance of the top surface of the sheet. Edges of the sheet are trimmed. 

Shock-wave data have seen most applications in the measurement of density at high pressure. Other properties of compressed condensed materials whose measurements are discussed in this chapter include sound speed and temperature. Review articles by Grady (1977), Yakushev (1978), Davison and Graham (1979), Murri et al. (1974), Al tshuler (1965), and Miller and Ahrens (1991) summarize experimental techniques for measuring dynamic yielding. 

The study of shock-wave equations of state of porous materials provides a means to expand knowledge of the equation of state of condensed materials to higher temperatures at a given volume than can be achieved along the principal Hugoniot. Materials may be prepared in porous form via pressing... 

Can dangerous materials build up in the process, e.g. traces of combustible and non-condensible materials ... 

It is important to note that even if the blowdown is effective in disengaging liquid and vapor, further condensation could occur downstream especially if the vented vapor exits the drum at a temperature above ambient conditions. A proportion of such condensible materials in the blowdown drum vapor release may condense as a result of cooling in the flare header and contact with seal water, and then disengage in the flare seal drum while condensible vapors which are not condensed out at this stage may condense in the flare stack or its inlet line, thus creating the potential for hazardous fallout of burning liquid from the flare. Condensed hydrocarbon in the seal drum can be entrained out with the... 

Where a group of connected vessels is considered as one unit for pressure relief purposes, consider the possibility of an alternative location for the PR valve such that the discharge stream would contain a smaller quantity of condensible materials. 

The purpose of regulation is to protect the public from the risk of nuclear power. PSA make it possible to express the risk numerically. However, NRC regulations have been pro.scriptive to achieve an unknown risk level. Clearly too much regulation that destroys the industry is not desirable and too little may fail to protect the public. A possible solution is the use of PSA in regulations. Such has been resisted because of the uncertainties on the other hand there are uncertainties in proscriptive regulation but no attempt is made to express them quantitatively. The following condenses material from Murphy (1996) to reflect NRC thinking on this subject. 

When the ejector system consists of one or more ejectors and intercondensers in series, the volume as pounds per hour of mixture to each succeeding stage must be evaluated at conditions existing at its suction. Thus, the second stage unit after a first stage barometric intercondenser, handles all of the non-condensables of the system plus the released air from the water injected into the intercondenser, plus any condensable vapors not condensed in the condenser at its temperature and pressure. Normally the condensable material tvill be removed at this point. If the intercondenser is a surface unit, there wall not be any air released to the system from the cooling w ater. 

Indeed, one often observes a more or less direct relationship between the rheological properties of melts and the mechanical strength of the condensed material. This is a commonplace statement in regard of, say, stiffness, since the equations relating the viscosity of heterogeneous materials with their composition... 

Lutz HD (1995) Hydroxide Ions in Condensed Materials - Correlation of Spectroscopy and Structural Data. 82 85-104... 

For lower chlorinated phenates the reactions become even more complicated. The phenols vaporize without decomposition, and the sodium salts react in the melt (Figure 5), as shown for sodium 2,4-dichlorophenate. The relative amount of dioxins produced is lower in favor of more highly condensed material. 

In summary thermal decomposition of chlorinated phenols does not generally lead to dioxins. There are, however, several conditions which by themselves or combined would favor dioxin formation. First, of all chlorinated phenols either in bulk or in solution, only pentachlorophenol produced measurable amounts of dioxin. Secondly (Table II), only sodium salts in salid state reactions produced dioxins in reasonable yields. In contrast, the silver salt of pentachlorophenol (Figure 8) undergoes an exothermic decomposition at considerably lower temperatures and produced only higher condensed materials. No dioxin was detected. 

In the manufacture of aniline by the hydrogenation of nitrobenzene, the offgases from the reactor are cooled and the products and unreacted nitrobenzene condensed. The hydrogen and inerts, containing only traces of the condensed materials, are recycled. 

A most striking result from the work described above is that the composition of the bottoms product and residues from the dissolution reaction did not depend on the chemical structure of the original coal material only their relative quantities differed. This supports the view of a mechanism involving the stabilisation of reactive fragments rather than an asphaltene-intermediate mechanism. The formation of a carbon-rich condensed material as a residue of the reaction and the fact that hydrogen transfer occurred largely to specific parts of the coal further supports this view. 

Finally, in Sect. 7.6, we have discussed how various free energy calculation methods can be applied to determine free energies of ensembles of pathways rather than ensembles of trajectories. In the transition path sampling framework such path free energies are related to the time correlation function from which rate constants can be extracted. Thus, free energy methods can be used to study the kinetics of rare transitions between stable states such as chemical reactions, phase transitions of condensed materials or biomolecular isomerizations. 

Chemical separations are often either a question of equilibrium established in two immiscible phases across the contact between the two phases. In the case of true distillation, the equilibrium is established in the reflux process where the condensed material returning to the pot is in contact with the vapor rising from the pot. It is a gas-liquid interface. In an extraction, the equilibrium is established by motion of the solute molecules across the interface between the immiscible layers. It is a liquid-liquid, interface. If one adds a finely divided solid to a liquid phase and molecules are then distributed in equilibrium between the solid surface and the liquid, it is a liquid-solid interface (Table 1). 

Pressure resistant construction is characterized by a design pressure of a vessel or equipment that is higher than the pressure that can be reached in case of an explosion or runaway reaction. When decomposition of condensed materials need to be considered then it is usually very expensive to realize pressure resistant construction because of the high pressures that can be expected. 

In such cases it is reasonable to step down to the molecular level of these materials and to think of a conjecture that many of the condensed materials properties may actually be connected to the properties of the individual macromolecules. Pursuing this idea one may follow two approaches. The first consists of molecular modeling of structures on a computer and simulating the material properties of interest. Alternatively, attempts can be made to set up a rigorous basic molecular theory. 

Accumulation of condensed material as aerosols in the atmosphere may take place by two basic processes by condensation of supersaturated vapor or chemical reaction that leads to spontaneous formation of new particles, and by condensation, absorption, or reaction on existing particles. In the latter case, the chemical reactions may actually take place on the surface of or within existing particles. 

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