Carry-over eliminating

The relatively low pX values seen for the benzoyl acetanilides, especiaHy as two-equivalent couplers, minimize concerns over slow ionization rates and contribute to the couplers overaH reactivity. But this same property often results in slow reprotonation in the acidic bleach, where developer carried over from the previous step can be oxidized and react with the stiH ionized coupler to produce unwanted dye in a nonimage related fashion. This problem can be eliminated by an acidic stop bath between the developer and the bleach steps or minimized by careful choice of coupling-off group, coupler solvent, or dispersion additives. 

These methods are primarily for water vapor removal. Removal of lubricating oil is secondary, although all drying systems will reduce its carry-over. It should be understood that complete elimination of lubricating oil, particularly in the vapor form, is very difficult and that when absolutely oil-free air is required, some form of non-lubricated compressor is the best guaranteed method. 

At the downstream end of the pipeline it is necessary to disengage the solids front the gas and this is most usually carried out in cyclone separators (See Volume 2, Chapter 8). However, there may be a carry-over of tine particles which must be eliminated before the gas is vented, and gas filters or electrostatic precipitators may be used for this purpose (See again Volume 2, Chapter 8). At the upstream end, the particles must be introduced using some form of positive feeder, such as a rotary valve or a blow tank. 

Metal alkyls can be prepared in a simple manner from the main group halides (X = Cl, Br, I) and the appropriate alkyl Grignard reagent (RMgl) or the alkyllithium salt (RLi), as shown for the cadmium alkyls (Equation (2)).13 The elimination of impurities from the precursor source is of great importance, as any remaining impurities are invariably carried over into the growing semiconductor layers. Incorporation of impurities, even at levels as low as 1015 free carriers per cubic centimeter (one part in ca. 107), can drastically affect the electronic properties of the... 

The need to remove suspended dust and mist from a gas arises not only in the treatment of effluent gas from a plant before it is discharged into the atmosphere, but also in processes where solids or liquids are carried over in the vapour or gas stream. For example, in an evaporator it is frequently necessary to eliminate droplets which become entrained in the vapour, and in a plant involving a fluidised solid the removal of fine particles is necessary, first to prevent loss of material, and secondly to prevent contamination of the gaseous product. Further, in all pneumatic conveying plants, some form of separator must be provided at the downstream end. 

SCIEX API 365 equipped with a TurboIonSpray interface operated in positive ion mode. The calibration range 0.124-497 ng/mL was readily validated with a negligible carry-over effect from this system. The method offered a total cycle time of 8 min and completely eliminated the manual sample preparation. ... 

It is important therefore to only use these designs when you can be sure that carry-over effects will not be seen. Introducing a washout period between period I and period II can help to eliminate carry-over so that when the subject enters period II their disease condition is similar to what it was at the start of period I. Cross-over designs should not be used where there is the potential to affect the underlying disease state. ICH E9 is very clear on the use of these designs. 

Volatile Treatment. This method of treatment may be used for units operating above 2000 psi (136 atm) drum pressure. In this method, no Solid chemicals are added lo either the boiler 01 pie-boiler cycle. By eliminating solid treatment, the volatile carry-over of solids is eliminated and consequently turbine deposits are avoided. Cycle pH is controlled at 9.0 to 9.5 with a volatile amine such as ammonia. Hydrazine is added as an oxygen scavenger in quantity sufficient to provide a concentration of 20 to 30 ppb at the economizer inlet. 

Steam Purity. The trend toward higher pressures and temperatures in steam power plant practice imposes a severe demand on steam-purification equipment for elimination of troublesome solids in the steam. Carryover may result from ineffective mechanical separation and from the vaporization of boiler-water salts. Total cany-over is the sum of the mechanical and vaporous carry-over of all impurities. 

A large capacity sea-water cooling tower is designed with a drift eliminator to drastically reduce the drift carry-over. The drift carry-over from the tower has in fact been reduced to only an order of 6 to 7 X 107 of the quantity of sea-water circulated for cooling, or is as low as 1/2000 or less as compared with 0.2% in the conventional fresh-water cooling tower. The present paper gives an outline of the service results of this cooling tower. 5 refs, cited. 

Significant droplet carry-over (drift) was detected at two new 2000 MW plants. More spray was found created in the larger installations and longer residence time in the larger towers increases droplet growth. However, the two recent occurrences were principally due to the use of eliminators which differed from the originally recommended designs in construction in one case, and in installation in the other. 

Oxidation Unit The oxidation unit is an empty pressure vessel that takes input reaction gases and blends in additional air from the bleaching column. The extra oxygen provided enables further oxidation to occur and raises the gas mixture temperature to 140°C. At the top of the oxidation unit is a mist eliminator to prevent carry over of acid vapour by entrainment. At the bottom of the vessel is the weak-acid drain. The oxidation unit is constructed from SS304L and has a design pressure of 1200 kPa... 

The time-honored method for fixing paper, established by Kodak, is the two-bath method. In the two-bath method, two fresh fixing baths are placed side by side. Paper is immersed in the first bath for a predetermined time, drained, and moved to the second bath for the same amount of time. If the first bath is fresh, the paper is completely fixed and only trace amounts of fixing by-products are carried into the second bath. There the action of fresh fixer breaks down any residual by-products, which are easily removed during washing. As the first fixer begins to age, increasing amounts of by-product are carried over to the second bath and there eliminated. 

During the operation of the tower, water is lost by evaporation, water droplets entrained in the outgoing air, and in a water purge, called blowdown. To reduce carry-over of water droplets the air flows across drift eliminators. The water droplets impinge on the drift eliminators and then flows down to the bottom of the tower. The droplet water loss is about 0.2% of the incoming water [11]. After leaving the drift eliminators, air flows up and out of the tower. Evaporation of water into air transfers heat from the water to the air. Cooling the water requires about 1.0 % evaporation for every 5.56 C (10.0 "F) drop in the water tempera-ture[l 1]. To reduce scale formation in the tower because of dissolved calcium or... 

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