Time control

CR-1629 Non destructive real-time control of the quality of electrical spot welding Dr. M. Cherfaoui CETIM... 

On-line analysis is often more expensive and difficult to set up initially but can be more accurate and rehable if performed properly. On-line analyzers can also be used to provide real-time control of a process through a secondary variable such as severity or conversion, as opposed to controlling a primary variable, such as temperature (36,52). 

Fig. 10. Wet high, intensity magnetic separator using cryogenically cooled coils and a stationary matrix where A is the feed control for top-fed or retention time control for underfed operation and B is the feed control for underfed or retention time control for top-fed operation.

Hquid residence time control scrap iaput no no Material input yes yes yes... 

Model plasters are manufactured from select finishing plasters with special emphasis on a clean, white color. Setting-time control agents, setting-expansion control additives, fillers, and pigments may be added. 

The polysulfide impression materials can be formulated to have a wide range of physical and chemical characteristics by modifying the base (polysulfide portion), and/or the initiator system. Further changes may be obtained by varying the proportion of the base to the catalyst in the final mix. Characteristics varied by these mechanisms include viscosity control from thin fluid mixes to heavy thixotropic mixes, setting-time control, and control of the set-mbber hardness from a Shore A Durometer scale of 20 to 60. Variations in strength, toughness, and elasticity can also be achieved. 

P,n and the roll compaction time control compact density. Generally speaking, as compaction time decreases (e.g., by increasing roll speed), the minimum necessary pressure for quahty compacts increases. There may be an upper limit of pressure as well for friable materials or elastic materials prone to delamination. 

By the very nature of batch processing, it is inevitable that process equipment will have idle time between batches. The idle time also could occur if the controller is not being used at all times during the execution of the batch (e.g., a flow controller may only be used during the feed of one of the reactants). During the idle time, control considerations such as reset windup must be considered to prevent the control signal from going outside of the control limits. 

The discrete-time control matrix B T) from equations (8.75) and (8.76) is... 

Ogata, K. (1995) Discrete-Time Control Systems, 2nd ed., Prentice-Hall, Inc., Upper Saddle River, NJ. 

The elastic-shock region is characterized by a single, narrow shock front that carries the material from an initial state to a stress less than the elastic limit. After a quiescent period controlled by the loading and material properties, the unloading wave smoothly reduces the stress to atmospheric pressure over a time controlled by the speeds of release waves at the finite strains of the loading. Even though experiments in shock-compression science are typically... 

In spite of these acknowledged advantages, low volume dipping chambers and automated, time-controlled dipping apparatus (Fig. 40 and 41) have only been available commercially for a few years. 

The low quantum yield of the photografting process (0 = 2 X 10 ) provides a good opportunity to control the network formation (curing time control), and accordingly, the desirable properties of the crosslinked or grafted copolymer might be obtained. 

The reliability of a modern electric power system depends on continuous real-time control of power and energy production, transmission line flows, system frequency, and voltage. This complex task will get more involved in the new environment with increased market participation on both the supply and the demand sides. 

A second method is a time-controlled valve allowing regular intermittent blowdown of the boiler. Again, regular checks need to be carried out to monitor the quality of water in the boiler. 

Steam flow to vessels can be controlled by motorized valves, allowing timed control of the valve. Such valves can also be made to modulate rather than on/off operation. 

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