Add surface

To add surface area, the supports are uniformly coated with a slurry of gamma-alumina and recalcined under moderate conditions. The wash coat acts to accept the active metals, typically low levels of platinum and palladium, in a conventional impregnation process. In the United States in passenger car apphcations the spherical catalyst is used almost exclusively, and methods have been developed to replace the catalyst without removing the converter shell when vehicle inspection reveals that emission standards are not met. 

The hetero Y-type layers were prepared by an alternating deposition of compound C180AZ0SN and arachidic add ( surface pressure = 25 mNm1 for C180AZ0SN and 30 mNm 1 for arachidic add, and subphase was 10 M aq. cadmium chloride solution). For the preparation of the Z-type layers, the monolayers of C180AZ0SN were deposited only during withdrawing substrates. The Y-type layers were prepared by the ordinary deposition procedure. 

Subsequent finishing of the crude product typically involves heating the aqueous pigment suspension, frequently to temperatures of 100 to 150°C. The crude pigment slurry is thus heated under pressure. This technique may be varied to a certain extent. It is possible, for instance, to add or to exclusively use either water soluble or water immiscible organic solvents or to add surface-active nonionic, anionic, or cationic agents. 

In mixtures containing nitric acid various fuels may be employed. Fuels used for hypergolic ones, i.e. those which autoignite on mixing, differ essentially from those used in other mixtures. In hypergolic mixtures, fuels are used which reac. violently with nitric acid, e.g. aliphatic or aromatic amines, furfuryl alcohol, mercapt tans, hydrazine etc. It is also advisable to add surface-active substances to the mixture-... 

Single screw extruder. Let us take the case of a single screw extruder section that works well when dispersing a liquid additive within a polymer matrix. The single screw extruder was already discussed in the previous section. However, the effect of surface tension, which is important in dispersive mixing, was not included in that analysis. Hence, if we also add surface tension as a relevant physical quantity, it would add one more column on the dimensional matrix. To find the additional dimensionless group associated with surface tension, as, and size of the dispersed phase, R, two new columns to the matrix in eqn. (4.32) must be added resulting in ... 

The lamellar habit adopted by crystalline polymers adds surface terms to the specific Gibbs function (chemical potential), most importantly the fold surface free energy, ae, which contributes 2ae/Xg for a lamella of thickness k and crystalline density q. In consequence melting points are lowered from T, for infinite thickness, to Tm according to the Hoffman-Weeks equation... 

Plasticizers are used in rubber compounds to assist in the mixing or molding of the rubber, to soften the final vulcanized rubber, or to add surface lubricity to the surface of the rubber component. Examples are... 

F304 is the common convection bank for two fired heaters in the reforming unit. Currently 1300-1900 t/day of flue gas from F304 leaves the stack at temperatures around 390 °C. This is considerably higher than the typical value of 220 C seen in peer units within the industry. One of the options proposed is to add surface area in the convection section for extra MP steam generation of 85 t/day with a cost savings of 703,800 per year at the expence of 1.9 MM capital cost. 

For the crude preheat train in the refinery plant, three beneficial modifications are identified. Modifications 1 and 2 add a new shell to each of the feed preheat exchangers serviced by the diesel pump-around (PA). Modification 3 adds surface area to the diesel product run down heat exchanger. Before implementing these changes, it is crucial to make sure that the existing pump can handle the increased diesel PA flow and the increase can be tolerated in product cut points. These modifications can save 47 million Btu/h of fuel in the crude heaters, equating to cost savings of 2.3 million per year. With only a 2.2 million installed cost, this project provides a fast payback. 

Early reports and patent applications of Stonehart and Watanabe [22], Antonucci et al. [23], and Antonucci and Arico [24] claim the advantage of the introduction of small amounts of sihca particles to Nafion to ino-ease the retention of water and improve the membrane performance above 100°C. The effect is believed to be a result of water adsorption on the oxide surface. As a consequence the back-diffusion of the cathode-produced water is enhanced and the water electro-osmotic drag from anode to cathode is reduced [3]. A recent report of the group of Arico et al. [25] confirms the effect of water retention with the inclusion of oxide particles in Nafion and the importance of the acidity of the particle surface. An increase in both strength and amount of add surface functional groups in the fillers enhances the water retention in the membrane SiO -PWA (modified with phosphotungstic acid) > SiOj > neutral-AljOj > basic-AI2O3 > ZrO. ... 

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