Temperature time-dependent

Influence of the mode of operation on process performance. The mode of operation of stirred-tank reactors can also significantly affect reactor performance. The history of concentrations will be changed by the time policy of reactant(s) addition to the reaction mixture. In view of our very limited possibility of controlling of temperature in stirred-tank reactors, the temperature-time dependencies for different policies of dosing will also be different. For example, the result of nitration depends upon the method of addition of nitric acid to aromatics, and the choice which phase is dispersed and which is continuous. Consequently, if the reaction is concentration- or temperature-sensitive the result will be dependent on the mode of operation (see Example 5.3.1.5). 

Industrial chemical processes are determined by recipe and production route. The recipe is the specification of a sequence of processing steps for the transformation of raw materials into the desired product(s). Specifications include quantity and quality of raw materials, composition of feeds, sequence of additions to the reaction zone, rate of dosing, temperature-time dependencies, pressures, etc. The production route also includes the specification of equipment in which processing steps are performed. 

A number of methods are used to evaluate a data set to describe the kinetics of carbonization, such as determining the temperature/time dependence of viscosity, quinoline insolubles formation, or weight loss ... 

The process is temperature-time dependent. It goes through the following stages ... 

The resulting expression depends upon the temperature/time dependence of the collection of constants, Cj T = qt — Tq). The resulting equation will have a particular time dependence, which is different for each sintering mechanism. 

Figure 7. Temperature-time dependence for adsorption of liquid from mesoporous adsorbent. 1 - linear program, 2 - quasi-isothermal program.

It is known that destruction of solids, specifically polymers, at any loading operation may be considered proceeding from general ideas on the nature of temperature-time dependence of strong solids. According to these ideas destruction is the kinetic process developing in the body under the load. The process of destruction means that the principle of disturbance summation should be kept. This principle may be expressed by the formula ... 

Fig. 38. The temperature- (time) dependent functions assumed to describe the relative seasonal change in effective transport rate >e and NH4 production rate R [Eqs. (6.1), (6.7), (6.8)]. The maximum value for each is taken as that occurring at 22°C in the models. Apparent activation energies of II and 18 kcal/mole were used for >e (macrofauna controlled) and R (microbe controlled).

Figure 12 Temperature-time dependence of the rate constant upon cooling from 900 °C to 450, 500, or 550 °C at 0.5°Cs then holding at the indicated temperatures (After ref. 103)...

Partially reduced thiepines are known. The thermal reaction of divinyl episulfide (222) was shown to be useful for the preparation of 4,5- (34) and 2,7-dihydrothiepine (35) <79JA294>. The product ratio is variable and temperature/time dependent (Equation (46)). A 2,3,4,5-tetrahydro- and a 4,5-dihydrothiepine are prepared from a thiepane derivative by the Pummerer reaction (see Section 9.03.7). 

As described above, the deformation of plastics compared to metal is viscoelastic and viscous. The temperature-time dependence of the properties of plastics (and... 

The tensile creep behaviour of specially oriented sheets of LDPE was studied by Gupta and Ward. However, their data took the form of a dependence of isochronous modulus on temperature time dependence and non-linearity being ignored. The interpretation of such data is reviewed elsewhere in this book. 

Fig. 9.14 Simulation results showing the effect of the choice of anode material rm thermal runaway. The plot on the left shows the cell surface temperature time dependence fm two different anode submodels...

Elevated temperature, time-dependent deformation, or creep, is a critical parameter that affects the performance of solder interconnections. This signihcant contribution is a result of the low solidus temperature of solder alloys. Even... 

Figure 3 shows possible modeling levels for seismic analysis of steel and composite bridges, starting from the simple to the comprehensive ones. Simple models, like the first three in Fig. 3, can be used for preliminary seismic analysis. They may be employed for the derivation of seismic forces and displacements on bearings, piers, fotmdations, or the soil. Comprehensive models, like the last three of Fig. 3, are mostly used at the main design phase since they also cover analysis for construction stages and service conditions where other loads due to traffic, wind, temperature, time-dependent cmicrete effects, etc. must be taken into account. 

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