Dosed-loop systems

There are heat transfer fluids (such as Paratherm OR) that resist oxidation and also offer increased thermal efficiency, significantly higher flash and fire points and longer service life. Precise uniform temperature control to 316C (600F) is provided, in dosed-loop systems where the heat transfer fluids are more than occasionally exposed to air. Typical performance characteristics are ... 

EGR can seriously degrade engine performance, especially at idle, under load at low speed, and during cold start. Control of the amount of EGR during these phases can be accomplished by the same electronic computer controller used in the dosed loop oxygen sensor TWC system. Thus the desired NOx reduction is achieved while at the same time retaining good driveability. 

Nevertheless, there are still some cooling systems (especially closed-loop systems) that do not receive any form of chemical inhibitor dosing or other treatment. This situation typically persists because the operator either remains uneducated or skeptical concerning the benefits and cost-effectiveness of water treatment or relies on low-cost labor to provide regular manual cleaning. 

Many closed-loop hot/cold/chilled water systems are not treated, perhaps due to the mistaken notion that treatment is not required. Only when severe corrosion and fouling/blockages problems occur is something done, by which time it is normally too late to fully recover the situation. Closed-loop systems should always be cleaned, passivated, and treated. Treatment is most usually applied by means of a dosing pot (bypass feeder) installed on a bypass line. Some operators also install sidestream filters to remove suspended iron oxide. This is most probably not necessary if the... 

Isothiazoline is a widely used biocide, but it is not effective against anaerobic bacteria. It is deactivated by hydrogen sulfide leaks. Also, do not dose to closed systems (because of the presence of 0.2% copper and 2 to 3% magnesium salts, which are used as product stabilizers and can increase the risk of galvanic corrosion). Additionally, the high pH of closed-loop systems will hydrolyze isothiazoline. Automated feed systems may be useful for dosing isothiazolines due to the severe skin irritant nature of this material. 

All of the systems mentioned below are open-loop systems that is, an amount of insulin is administered, or insulin is delivered at a given rate, and for several hours this insulin manages the serum glucose in an unknown way. After some time, the glucose may or may not be measured, and another dose of insulin is administered, or the delivery rate is adjusted. 

The sub-systems will be a mixture of hardware and software, varying in complexity from single iVo channels, interlocks, dosed loops and. sequences through to complex control schemes and self-diagnostics. 

Continuous in-line measurements and control of the mass material balance in the process, with automatic feedback to the reactants dosing devices (performed either by computerized system or by traditional flow control loops). 

Early in the program, critical components (e.g.,the turbomolecular pump) and circuit boards were tested for their ability to survive neutron and gamma irradiation rates and doses similar to those that would be received from exposure to the detonation of a tactical nuclear device. All components were powered up at the start of the gamma irradiation tests but not during the neutron irradiation tests. Circuit boards were protected by circumvention circuits that powered down critical circuits in 10 to lOOps upon detecting radiation. All components survived the nuclear radiation tests. This unusual performance was noted with positive commendations by the staff at the White Sands Missile Range, where the tests were performed. Tests of the fully integrated CBMS II system, installed in a reconnaissance vehicle, will be conducted in the future. 

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