Crystal size INDEX

In 1921, a discontinuous index of refraction of vitreous Si02 near the a—P transition of quart2 (crystalline Si02) was noted (17). These data and subsequent x-ray investigations of vitreous siHca led to the suggestion (18) that crystaUites on the order of 1.5 nm were present. It was demonstrated, however, that the crystal size would be less than 0.8 nm, and it was suggested that the term crystal loses meaning for these dimensions (19,20). 

Figure 7.9 EJfect of mean residence time on mean crystal size parameter i = hjg, the relative nucleation to growth order index)...

Pigments Density (g cm-3) Refractive index a(BET) (m2 g"1) Crystal size (pm)... 

Four types of REY zeolite (Si/Al = 4.8) with different crystal sizes and acidic properties were used. The physical and chemical properties of the fresh zeolites are given in Table 6.4. Polyethylene plastics-derived heavy oil, shown in Table 6.2, was used as the feed oil. The cracking reaction was conducted in a tubular reactor filled with catalyst particles under the following conditions time factor W/F = 0.2-3.0 kg-catkg oil h and reaction temperature = 300-450°C. The lumping of reaction products were gas (carbon number 1-4), gasoline (5-11), heavy oil (above 12), and a carbonaceous residue referred to as coke. The index of the gasoline quality used was the research octane number (RON), which was calculated from Equation 6.1 [31]. 

Explore crystal size distribution as a function of solids holding time r, fines system cut puint Lf, and flow index into fines sytem ft. 

Optical Crystallographic Properties. As prepared by the thermal decomposition of ammonium hexafluorovanadate-(III), vanadium(III) fluoride has too fine a crystal size for the determination of optical properties with a polarizing microscope. Heating to 1350° in a platinum tube forms twinned crystals that are easily studied. According to Weaver, these crystals are biaxial (y=-) with optic angle (2V) of 5 to 10°. The a- and y-refractive indexes are, respectively, 1.536 and 1.544. 

Judgment of steady state. The judgment of the time needed for the response to reach the steady state is generally referred to settling time 65, which is necessary in order to evaluate the required time for start-up operation. Attainment of the steady state was determined from the convergence of the < tal size distribution. This was done by the use of the performance index (e) which is defined as the change in the mass based crystal size distrunition in every 1 residence time. 

P-quartz. The P-quartz crystals are <0.1 pm in diameter. Crystal sizes below the wavelength of visible light (A. = 0.7-0.4 pm), a good match in refractive index between the glass and the crystal phase, coupled with a low birefringence result in high transparency. Table 26.4 lists the compositions and applications of some commercial transparent LAS glass-ceramics based on P-quartz. 

A bivariant linear eq uation, contain ing factors such as phase percentages, crystal sizes, morphology and cluster indexes, for predicting the 28-day mortar strength was presented by Sinha, Rao, and Akhouri (1991). The standard deviation was said to be 17.9 kg/ cm agreeing closely with the actual strength. 

The ratio of crystal growth rate rg = dx/dt, and the nucleation rate dn/dt, or Bg, is plotted as the crystal size or grain index against the supersaturation a ... 

Ti02 particles in HDPE matrix aid the polymer chains in crystalhzing into more perfect and thermally stable lamella. The number of nucleation sites is dramatically increased and the crystal size decreased. The solar reflectance was related to the degree of crystallinity, the spherulite size of HDPE, refractive index, and distribution of Ti02 particles in HDPE matrix. The ratile Ti02 increased the total solar reflectance from 28.2 to 51.1%. ... 

Cellulose concentration (% w/w) Draw- down ratio Linear density (denier) Tenacity (g den ) Elongation (%) Initial modulus (g den ) Second bath Crystallinity index (%) Apparent crystal sizes (A) Crystal orientation factor (fc)... 

The "intercalaction" peak, here indexed as (100) in terms of the structure depicted in the lower part of Fig. 6 is very well resolved. In addition there is a very broad peak with maximum at about 2 =20. All features of the initial polymer structure have disappeared. The second peak may be decomposed in contributions from various reflections as indicated by the curve marked "Th". It is actually the expected intensity distribution for the peaks the position of which is indicated as well and which are assumed to be broadened by a gaussian profile due to limited crystal size and defects. 

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