Similarity flooding

A similar flood occurred at Three Mile Island Unit 1 in April, 1977, caused by a leak in the circulating-water system casing of one of the circulating-water pumps. However, because of the plant s layout, damage was confined to the six circulating-water pumps and did not affec y other systems (Verna, 1981). 

Melnik S, Garcia-Molina H, Rahm E (2002) Similarity flooding A versatile graph matching algorithm and its application to schema matching. In ICDE. IEEE Computer Society, Washington,... 

Contrary to most aggregation-based approaches, Similarity Flooding/Rondo [Melnik et al. 2002, 2003] uses a graph propagation mechanism to refine similarities between schema elements. Thus, it holds specific parameters. The first one is fixpoint formula, which enables the computation of updated similarities and the end of execution of the propagation. Different fixpoint formulas have been tested and evaluated in Melnik et al. [2002], In addition, several filters are proposed to select among all candidate pairs the ones that Rondo displays as mappings. Constraints (on cardinality and types) or thresholds are examples of filters. 

Fig. 3.2 Hypoglycemia causes an increase in tissue aspartate and decrease in glutamate, while both amino acids flood the extracellular space of the brain. GABA similarly floods the extracellular space, but its inhibitory effects at often insufficient to prevent hypoglycemic convulsions in the face of the excitatory amino acids released. Data from Norberg ruid Siesjb (1976) for whole tissue and extracellular data from Sandberg et al. (1986) (See also Color Insert)...

Both flooding calculations give similar flood% for this example. Thus, it could be expected that tray design has flooding% less than 80% in normal operation, and thus liquid entrainment will be less than 0.1 lb liquid/lb vapor. It should be noted that the Glitsch flood correlation 13 (Glitsch, 1974) is the most commonly used flood correlation for industrial distillation. 

Venturi scmbbers can be operated at 2.5 kPa (19 mm Hg) to coUect many particles coarser than 1 p.m efficiently. Smaller particles often require a pressure drop of 7.5—10 kPa (56—75 mm Hg). When most of the particulates are smaller than 0.5 p.m and are hydrophobic, venturis have been operated at pressure drops from 25 to 32.5 kPa (187—244 mm Hg). Water injection rate is typicaUy 0.67—1.4 m of Hquid per 1000 m of gas, although rates as high as 2.7 are used. Increasing water rates improves coUection efficiency. Many venturis contain louvers to vary throat cross section and pressure drop with changes in system gas flow. Venturi scmbbers can be made in various shapes with reasonably similar characteristics. Any device that causes contact of Hquid and gas at high velocity and pressure drop across an accelerating orifice wiU act much like a venturi scmbber. A flooded-disk scmbber in which the annular orifice created by the disc is equivalent to a venturi throat has been described (296). An irrigated packed fiber bed with performance similar to a... 

If the same measurement is repeated for different [BJ it should be possible to extractjy by plotting log vs log [BJ. This should be a straight line with slopejy. In a similar manner, can be obtained by varying [CJ. At the same time the assumption that x equals 1 is confirmed. Ideally, a variety of permutations should be tested. Even if xis not 1, and the integrated rate equation is not a simple exponential, a usefiil simplification stiU results from flooding all components except one. 

Fair s empirical correlation for sieve and bubble-cap trays shown in Fig. 14-26 is similar. Note that Fig. 14-26 incorporates a velocity dependence (velocity) above 90 percent of flood for high-density systems. The correlation implicitly considers the tray design factors such as the open area, tray spacing, and hole diameter through the impact of these factors on percent of flood. 

Not many operating data of large-scale hquid/hquid reactions are published. One study was made of the hydrolysis of fats with water at 230 to 260°C (446 to 500°F) and 41 to 48 atm (600 to 705 psi) in a continuous commercial spray tower. A small amount of water dissolved in the fat and reacted to form an acid and glycerine. Then most of the glycerine migrated to the water phase. Tlie tower was operated at about 18 percent of flooding, at which condition the HETS was found to be about 9 m (30 ft) compared with an expec ted 6 m (20 ft) for purely physical extrac tion (Jeffreys, Jenson, and Miles, Trans. In.st. Chem. Eng., 39, 389-396 [1961]). A similar mathematical treatment of a batch hydrolysis is made by Jenson and Jeffreys (In.st. Chem. Engrs. Symp. Ser, No. 23 [1967]). 

KSC increases the failure rates of components from causes such as earthquake, fiic. flooding, tornado, erroneous maintenance or inis-sp>ecifying the operating cnvironmcni. [ nvironmental qualification (EQ) of equipment, specified by Regulatory Guide 1.97, as.surcs ihc operation of instruments in an accident environment. Similar qualification is required for a tiesi uu-basis earthquake. 

Ice and hail, snow, etc. can cause a loss of off-site power. The reactor building was designed to withstand blast pressure of 1,000 Ibs/ft can withstand tornado missile impact (Sharp, 1986). A tornado could damage the reactor by hitting the river water pump houses similar to the flooding scenario. 

System limit flooding is similar to jet flooding, due to low surface tension and low density difference between liquid and vapor. Terminal velocity of some entrainment droplets is less than the upward vapor velocity, and hence they are carried up into the tray above, thus reducing tray efficiency and capacity. 

For hot water boilers the burner controls will be similar but controlled by a combination of pressure and temperature signals. A single overriding level control will be fitted to the flooded boiler to protect against any accidental low-water condition. 

The lubrication requirements for single-screw type compressors are not severe, but in oil-flooded rotary units, the oxidizing conditions are extremely severe because fine droplets of oil are mixed intimately with hot compressed air. In some screw-type air compressors, the rotors are gear driven and do not make contact. In others, one rotor drives the other. The heaviest contact loads occur where power is transmitted from the female to the male rotor here the lubricant encounters physical conditions similar to those between mating gear teeth. This arduous combination of circumstances places a great demand on the chemical stability, and lubricating power, of the oil. 

It machines in a similar manner to soft copper, and high-speed-steel tools with high cutting speeds are most satisfactory. Trichloroethane is recommended as a cutting medium and the work must be kept well flooded at all... 

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