High-Pressure Injection Method

Molecules tend to move from a high-concentration area toward a low-concentration area, and the flux is a function of the concentration gradient. Therefore, by creating and keeping a concentration gradient near the surface of the source chemical, it will be continually released into the dilution gas stream through the diffusion process. 

The diffusion method can be used to deliver higher-concentration vapor than the permeation method (discussed in next section) but lower concentration than the evaporation method. It can produce vapor with concentration in the parts-per-billion to 100-ppm range and is used for generating vapor from liquid chemicals. 

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The smallest diameter attained for bismuth nanowires by the pressure injection method was about 13 nm, using a pressure of approximately 0.3 kbar (Zhang et al., 1999). Finer nanowires might be fabricated by increasing injection pressures (Huber et al., 2000), but it remains to be seen if the anodic alumina templates would retain their structural integrity under those high pressures. 

Depending the method used to meter the hydrogen to the engine, the power output compared to a gasoline engine can be anywhere from 85% (intake manifold injection) to 120% (high pressure injection). 

A well-known floating catalyst method developed at Rice Uruversity is the so-called HiPCO (high-pressure CO) method. In this case, the growth of SWNTs is realized by disproportionation of CO catalyzed by Fe clusters generated in situ by decomposition of Fe(CO)s in continuously flowing CO at high pressure and elevated temperature (79). A mixture of the Fe precursor and CO is injected into the reactor... 

The developed method was apphed on test system representing simplified high pressure injection system of the nuclear power plant. The comparison of the obtained results with the results of other two optimization algorithms is done. The obtained results show that particle swarm optimization algorithm surpass other optimization algorithms by its speed and optimal function value. 

While not strictly considered emulsions, two other systems may be classified in this category, both of which comprise very small particles of silicone fluids in aqueous dispersions. The first method of preparing these microdroplets involves in situ polymerization of a water-soluble vinyl monomer or mixtures of said monomer and acryl comonomers. The silicone fluids are first dispersed into microdroplets in the water phase by means of high-speed agitation and then the vinyl monomers or cationic polymers are added at elevated temperatures in the presence of free-radical catalysts. The resulting aqueous polymer matrix contains stable, discreet microdroplets of the silicone fluids. The second method utilized to prepare such a fine dispersion is very-high-pressure injection of silicone into the aqueous phase. These microdroplets have been referred to as nanoparticles, but they are actually nanometer-sized fluid droplets as opposed to nanometer-sized sihcone resin particles, which are referred to by the same term (86). Both of the systems described above have been claimed to readily deposit onto hair and skin, and to increase ease of formulation (87,88). 

In the gas plant, corrosive agents (H,S, HCN, and NHj) are r concentrated at high-pressure points. Water is usually injected into the first and second-stage compressor discharges. The water contacts the hoi gas and scrubs these agents. There are two common injection methods forward cascading and reverse cascading. 

A knowledge of processing methods will be useful to the designer to help determine what tolerances can be obtained. With such high-pressure methods as injection and compression molding of 2,000 to 30,000 psi... 

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