Decade switch

A low speed shutter (S2) is used for making computer controlled dark current measurements. A high speed electromagnetic shutter (SI, 22-8411, Ealing Corp., South Natick, MA 01760) is used for controlling the time interval that the vidicon is illuminated. Exposure times are entered into the shutter control module from a multiplier and a decade switch register providing shutter times of from 30 ms to 10 s. 

Care must be taken to speeify a low and high limit to the output power of the eonverter. At light loads, the frequency can drop drastically. If the frequency comes within a decade of the output T-C filter pole, too much ripple will be allowed to pass to the load. At heavy loads, the frequency can become too high, and the power switch conduction cycles will run together, thus producing a nonzero current switching situation. So,... 

There are several problems with these standards for older coal-fired plants that limit a sensible NO,-reduction policy. First, they are relatively lenient. Because they require only that low-NO, burners be used at coal-fired plants, relatively inexpensive NO,-reduction technologies are not being used, because the plants already meet the minimum standards. Second, standards are established on a technology-by-technology basis, and have resulted in more lenient requirements for dirtier technologies. This has created little or no incentive to switch to cleaner processes in the past decade. Thirdly, these standards are input-based, which means they provide no incentive for efficiency within any technology category. 

In the last decades, aluminium and aluminium alloys have received an increasing interest in cryogenic applications [5-7], Pure aluminium is used in the building of superconducting heat switches (see Section 4.3) because of its high switching ratio [8,9] and convenient critical field. Satisfactory procedures for welding have also been found [10,11],... 

The fossil hydrogen production option dominates during the first two decades while the infrastructure is being developed, and also in later periods if only economic criteria are applied initially on the basis of natural gas, later with increasing gas prices more and more on the basis of coal (where available). Carbon capture and storage will be critical for these pathways, if hydrogen is to contribute to an overall C02 reduction in the transport sector. The production mix between gas and coal is highly sensitive to the ratio of feedstock prices a switch occurs at a gas coal price ratio of about 2.5. 

If one examines the gp and gB on the graph shown in Fig. 4.40, one can make some interesting observations. The burner port diameter is fixed such that a rich mixture ratio is obtained at a value represented by the dashed line on Fig. 4.40. When the mixture ratio is set at this value, the flame can never flash back into the stove and bum without the operator s noticing the situation. If the fuel is changed, difficulties may arise. Such difficulties arose many decades ago when the gas industry switched from manufacturer s gas to natural gas, and could arise again if the industry is ever compelled to... 

These data suggest that biogeochemical domains undergo a systems switch on time scales required for return of exported nutrients to the sea surfece. In oligotrophic waters, this return requires decades to centuries as the strong density stratification at these sites forces the return to proceed through the meridional overturning circulation. 

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