Effect on setting time

Many inorganic salts affect the setting times of calcium aluminate cements and are effective in concentrations of 0.5% (L6,C53,R45). The effects on setting times differ greatly both in direction and in relative magnitudes from... 

The use of air-entraining admixtures has no significant effect on setting time. 

Figure 5.9 The effect of SiOj/AljOj mass ratio on setting time, compressive strength and opacity (Hill Wilson, 1988a).

Figure 6.21 The effect of powder/liquid ratio on setting time and compressive strength of a dental silicate cement (Wilson Batchelor, 1967b).

Table 9.1. Effect of zinc oxide type on setting time of ZOE cements Prosser <6 Wilson, 1982)...

V. E. Akhrimenko, E. A. Aleksandrova, Z. N. Tkachenko, E. A. Dmitriev, F. N. Derevenets, and S. A. Abramov. Effect of aluminum compounds on setting time of cement slurry and strength of set cement. Stroit Neft Gaz Skvazhin Sushe More, 10-11 30-32, October-November 1997. 

Fig. 5.20 Effect of temperature on setting time with accelerators. 

The plot presented in Fig. 4.6 shows how the Reynolds number plays an effect on mixing time. The graph shows two sets of points, one for a mixing tank with baffles and the other for a mixing tank without baffles. 

Figure 11.15 Effect of temperature on setting times of silicate grouts. (From Ref. 5.)...

Figure 11.30 Effect of pH on setting time of iignosuifonate grouts. (pH controiied with H2SO4 and NaOH.)... 

Figure 11.34 Effect of percent solids on setting time for lignosulfonate grout. 

Sometimes we find it advantageous to focus our stochastic description not on the probability but on the random variable itself. This makes it possible to address more directly the source of randomness in the system and its effect on the time evolution of the interesting subsystem. In this case the basic stochastic input is not a set of transition probabilities or rates, but the actual effect of the environment on the interesting subsystem. Obviously this effect is random in nature, reflecting the fact that we do not have a complete microscopic description of the environment. 

Once the system variables are set within reasonable ranges, the parameters that have most effect on migration times and selectivity are the composition, concentration and pH of the electrolyte solution, and the presence of additives, if used, to provide additional selectivity [100,101,404-406]. Four features are important for an acceptable separation (i) the analytes must have different mobilities (ii) the electrolyte solution must be homogeneous and the field strength uniform along the column (iii) neither analytes nor matrix components must interact with the column wall and (iv) the conductivity of the electrolyte solution must exceed the conductivity of the sample. Suitable buffers with their pKa and ion mobility values are given in Table 8.2. 

The setting time of concrete containing an accelerator will be shorter than that of the equivalent plain concrete containing no accelerator. The effect of calcium chloride on setting time is generally greater than that of calcium formate. 

Fig. 4.14 Effect of gypsum and hemihydrate content on setting time (according to [1])...

Reliability and precision of the measurements were assessed. For a test set-up sample, we use an aluminum block was used which circumvents time dependent property changes associated with the drying of the green ceramics. Using this test sample the following parameters were varied to determine their effect on transit time measurements ... 

Portland cement is an accelerator for CAC and vice versa. The effect of proportions of each component on setting time is illustrated in Fig. 4. Ternary blends of portland blast-furnace cement and CAC also have an acceleratory effect. 

Table 4. Effect of Additives on Setting Times of Phosphate Cement ...

Although isotope-dilution analysis can be very accurate, a number of precautions need to be taken. Some of these are obvious ones that any analytical procedure demands. For example, analyte preparation for both spiked and unspiked sample must be as nearly identical as possible the spike also must be intimately mixed with the sample before analysis so there is no differential effect on the subsequent isotope ration measurements. The last requirement sometimes requires special chemical treatment to ensure that the spike element and the sample element are in the same chemical state before analysis. However, once procedures have been set in place, the highly sensitive isotope-dilution analysis gives excellent precision and accuracy for the estimation of several elements at the same time or just one element. 

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