Time factor types

Many factors affect the rate and extent of coal liquefaction, including temperature, hydrogen partial pressure, residence time, coal type and analysis, solvent properties, solvent-to-coal ratio, ash composition, and the presence or absence of a catalyst. Many kinetic expressions have appeared in the literature, but since they are generally specific to a particular process, they will not be listed here. In general, liquefaction is... 

Table 10.5 provides performance data regarding the SCWO process. Typical destruction efficiencies (DEs) for a number of compounds are also summarized in Table 10.5, which indicates that the DE could be affected by various parameters such as temperature, pressure, reaction time, oxidant type, and feed concentration. Feed concentrations can slightly increase the DE in supercritical oxidation processes. For SCWO, the oxidation rates appear to be first order and zero order with respect to the reactant and oxygen concentration, respectively. Depending upon reaction conditions and reactants involved, the rate of oxidation varies considerably. Pressure is another factor that can affect the oxidation rate in supercritical water. At a given temperature, pressure variations directly affect the properties of water, and in turn change the reactant concentrations. Furthermore, the properties of water are strong functions of temperature and pressure near its critical point. 

In the last mentioned case, where a time factor may introduce bias, or in cases where inhomogeneities of the sampled material may influence the responses, block designs can be chosen. To eliminate several block effects one can select a latin square design. With regard to the arrangement of experiments we refer to appropriate text books, e.g. [BANDEMER et al., 1973 MORGAN, 1991]. There the reader may find special types of design which fit his requirements. 

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]. 

Figure 6.22 shows the typical carbon number distribution of products obtained using Ni-REY in steam at 400°C and with a time factor W/F of 1 h. The results obtained with MFI-type (ZSM-5) and REY zeolites in N2 are also shown for comparison. Although steam was used as a carrier gas, Ni-REY gave the largest amount of fuel, e.g. gasoline, kerosene, and gas oil, thus suggesting the potential use of steam as a carrier gas. 

Gralnidc HR, Ride ME, Mckeown LP, Williams SB, Parker RI, Maisonneuve P, Jeanneau C, Sultan Y Platelet von Willdtrand factor An important determinant of the bleeding time in type I von Willebrand s disease. BIocxl68 58-61,1986. 

It has been recently demonstrated [4] that the disproportionation mechanism of n-propylbenzene essentidly depends on the nature of the catalyst it is mainly of Sn2 type on Y-zeolites and leads to a meta/para (m/p) ratio s 2. This has been also observed for sBB under atmospheric pressure [5]. The ratio m/p between the two di-sec-butylbenzene isomers can be assumed as an indication of the relative extent of the Sn2 and SnI mechanisms the higher the m/p ratio, the higher the Sn2 extent. At low time factor values, when DBA is present in small amount (Fig.2a), the m/p ratio observed is about 1.6 and is constant with time on stream (t-o-... 

As mentioned and discussed in the section on stability testing, no uncertainty factor should come from a possible instability. It is far too hazardous to try to deduce from simple measurements over a certain period of time, which type of decrease a possible degradation of the material will follow. Degradation, as discussed in Chapter 4, can affect the matrix and the substance certified. The kinetics of the degradations are not simply of a first order and may even change in time. Therefore, corrections of any kind for instability should be forbidden. Unstable materials should never be certified. 

In a PGA model over dicarboxylic acids from degradation of the degradable polyethylenes. Fig. 10, PCI was totally settled by the time factor, whereas the class separation was described in PC2. The degraded samples were positioned at different sides of the mid-axes depending on the type of pro-oxidant system. 

Reactions were conducted with a flow type reaction apparatus under atmospheric pressure. The standard reaction conditions were as follows temperature 750 °C, time factor (W/F) 1.0 g"h/mol, feed gas composition CH4 14%, O2 1.6%, N2 balance, catalyst weight 1.0 g. 

An application torque may be given as between x and y lb ft ins or N m. The removal torque will change according to how long after application a check is made, the environment in which it has been stored, the type of materials used, etc. Hence removal torques may differ considerably after 10 min, 2 h, 24 h, 7 days, etc.—therefore the time factor between application and removal may have to be assessed and documented. Such changes are usually greater when plastic caps are applied to plastic containers. 

The oxygen-iodine chemical transfer laser, 02( A) + I( / 3/2) 02( 2)+ I( /, /2)> based on the same electronic transition as the iodine photochemical laser, I( 7, /2) I( 3/2). and a few systems operating on pure rotational transitions are among the recent developments in chemical laser research. Other electronic lasers such as the iodine photochemical laser and the large group of excimer lasers are also classified sometimes as chemical lasers. Yet, most chemical laser systems utilize vibrotational transitions, almost exclusively of diatomic molecules. Our discussion will be confined to this type of chemical lasers. To emphasize the nonequilibrium characteristics and the time factor we shall consider only pulsed lasers. We shall not discuss important subjects such as optical properties, gas dynamic factors, and computational methods. As specific guiding examples we shall refer to the well-studied F-l-H2->HF-h H laser and the relatively simple (only one active vibrational band) Cl -I- HBr- HCl -I- Br system. ... 

As can be seen from Table VII, the mercury concentration in all seven core samples ranged from < 0.08 mg/kg to a maximum concentration of 0.32 mg/kg. The maximum concentration (0.32 mg/kg) occured at a depth of 24-31 cm at the mouth of the Sucker Brook watershed system. All otha samples were generally at concentrations near the 0.08 mg/kg detection limit no discernible difference in mercury concentration was observed with depth and the variation that does exist is more likely attributed to sediment type rather than to a depth (time) factor. 

IR spectroscopic studies were conducted of the reaction of polyacrylic acid(PAA) and metal oxides (zinc oxide, calcium oxide, cupric oxide, chromium oxide and aluminium oxide). Factors such as the amount of metal oxide, reaction time, solvents, type of metal oxides and temp, were also evaluated to derive the optimum conditions for this reaction. The reactions of chromium oxide and aluminium oxide were far from complete. An extra solvent added to the reaction system could increase the solubility of PAA and metal oxide in the solution to cause complete reaction. The reactivity of the reaction was increased by using a hydrophilic solvent, particularly water and methanol. Furthermore, the reaction rate increased when temp, decreased. The reactivity of the reaction was proportional to the pH value of the metal oxide in the aqueous solution. 16 refs. 

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