Surface area as a function

Fig. 14. BET surface area as a function of position in a large CFCMS monolith with 10.4 4% bum-off [27].

Fig. 15. Mesopore surface area as a function of pore diameter obtained from mercury intrusion data for PAN derived carbon fiber porous monoliths [28].

Figure 9.0. Surface area as a function of volume of exchanger for different types...

Figure 1 shows more detailed data of the change of the surface area as a function of the Cs content, x in CsxH3-xPWi2O40. The surface area of the acid form (x = 0), 5 m g-1, decreased as x increased to 2 (the surface area of Cs2 was only 0.5 m2 g-1). However, the surface area greatly increased as x exceeded 2 and... 

In heterogeneous catalysis reactions take place at the surface of the catalyst. In order to maximize the production rates, catalysts are, in general, porous materials. In practice, the surface area of catalysts ranges from a few up to 1500 square metres per gram of catalyst. It is instructive to calculate the specific surface area as a function of the particle size. 

Figure 3.11. Specific surface area as a function of crystallite size of Ni (p = 8900 kg/m ) d = particle diameter (nm).

However, nitrogen adsorption reveals considerable differences, as shown in Fig. 5.14, in terms of surface area distribution of a 28-day hydrated C3S specimen [20], or of specific surface area as a function of hydration time... 

Figure 6. Methane conversions (normalized to unit surface area) as a function of the mole fraction for the substitution (x) of ytterbium in SrCe i.x)YbxO(3 x/2). Conditions for catalytic experiment were 810°C in a quartz reactor using an inlet feed composition ofHe/C /02/N2 =11.5/2.0/1.0/0.5...

Jurs-PNSA-2 (characterization of positively charged surface area as a function of molecular shape and electronic considerations)... 

Fig.4. Potential energy per thermal energy and surface area as a function of the distance to a nanoslab with occluded TPAOH and TB AOH and the temperature.

Walker, Foresti, and Wright (73) have studied surface area as a function of the amount of carbon consumed by the C + C02 reaction at 900° to 1000° C. They find that an increase in internal surface area increases the rate of reaction until the graphite sample is about 10% consumed. Thus in one case the area changes by a factor of 14. Both rate and area become constant after 10% consumption of the sample. 

Sped c surface area as a function of particle size. 

GEPOU87 Sovent Accessible Surface (Area) as a Function of Probe Radius... 

Conventional preparation aethod. The mixed gel for crystallization of ZSM-34 was hydrogelatinous as noted in the experimental section. The change in crystal morphology and BET surface area as a function of the crystallization time at 100°C is shown in Fig.1 with the results of methanol conversion by these materials. 

The true intrinsic kinetic measurements require (1) negligible heat and mass transfer resistances by the fluids external to the catalyst (2) negligible intraparticle heat and mass transfer resistances and (3) that all catalyst surface be exposed to the reacting species. The choice of the reactor among the ones described in this section depends upon the nature of the reaction system and the type of the required kinetic data. Generally, the best way to determine the conditions where the reaction is controlled by the intrinsic kinetics is to obtain rate per unit catalyst surface area as a function of the stirrer speed. When the reaction is kinetically controlled, the rate will be independent of the stirrer speed. The intraparticle diffusional effects and flow uniformity (item 3, above) are determined by measuring the rates for various particle sizes and the catalyst volume, respectively. If the reaction rate per unit surface area is independent of stirrer speed, particle size, and catalyst volume, the measurements can be considered to be controlled by intrinsic kinetics. It is possible... 

From the plots of BET specific surface areas as a function ofheat-treatment temperature for both Vulcan XC-72R and Shawinigan acetylene black, shown in Fig. 10, it is obvious that the latter black has experienced a much higher temperature than that for Vulcan XC-72R. It is well known that Shawinigan acetylene black is formed at a high temperature, which leads to significant surface area diminution. 

Figure 2 Distribution of surface area as a function of altitude for Venus, i.e., the hypsometric curve (after Fegley and Treiman, 1992) (reproduced by permission of American Geophysical Union from Geophysical Monograph...

A is the rate of loss of membrane surface area as a function of time Jo is the initial value of the flux J is the flux observed after inhnite time fp is the time of permeation... 

If the adsorption were uniform, we would expect the adsorbate concentration to increase with decreasing size. This effect can be eliminated if the amount of adsorbate per unit area of particles is estimated. Assuming that the particles are spherical and have constant density, it is possible to calculate the relative amount adsorbed per unit surface area as a function of... 

Figure 2. Catalyst surface areas as a function of time on stream (TOS). Negative TOS denote catalyst pretreatment positive TOS denote Fischer-Tropsch synthesis.

Selection of solvent/antisolvent, temperature, and overall concentration were critical parameters in affecting the supersaturation as well as the nucleation and crystal growth rates. Table 9-3 summarizes the experimental conditions and results of impinging jet crystallization of DFP. Figure 9-29 further shows the flnal product surface area as a function of supersaturation. As shown in Fig. 9-29, higher... 

Figure 9-29 Surface area as a function of supersaturation. The higher the supersaturation, the higher the surface area.

Figure 12.4 Accessible surface area as a function of pore width for a set of activated charcoals (activation increases from Cl to C4). The liquids used for immersion calorimetry are, in order of increasing size benzene, methanol, isopropanol, cyclohexane, tertiary butanol, and a-pinene. (Adapted from [36].)...

FIGURE 4 Specific surface area as a function of pretreatment temperature for (0) Zr02 and ( IZrOj-SO ". 

Fig. 1 Variation of Surface area as a function of TiO, content in the support...

The pore volume and pore surface-area as a function of pore radius for an active mass formed from 3BS paste on lead-antimony grids are presented in Fig. 3.29(a) and (b), respectively. The pore volume begins to rise at a pore radius of 1 pm and the surface area at a pore radius of 0.1 pm. Pores with 0.1 pm radius have a specific pore volume of 0.065 cm g , which is about 62% of the total pore volume. The surface area of the pores of this same size is only 6% of the total surface-area of the PAM. These results demonstrate that the macrostructure of the PAM is basically built up of pores with radii larger than 0.1 pm (macro-pores), and these pores serve as the main transport system for the flows of ions and H2O between the bulk of the solution... 

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