Excess losses

When drilling through normally pressured formations, the mud weight in the well is controlled to maintain a pressure greater than the formation pressure to prevent the influx of formation fluid. Atypical overbalance would be in the order of 200 psi. A larger overbalance would encourage excessive loss of mud Into the formation, slow down... 

Similarly, when drilling into an underpressured formation, the mud weight must be reduced to avoid excessive losses into the formation. Again, it may be necessary to set a casing before drilling into underpressures. 

Similarly, when drilling into an underpressured formation, the mud weight must be reduced to avoid excessive losses into the formation. If the rate of loss is greater than the rate at which mud can be made up, then the level of fluid in the wellbore will drop and there is a risk of influx from the normally pressured overlying formations. Again, it may be necessary to set a casing before drilling into underpressures. 

This preparation is an example of the use of di-M-butyl ether as a solvent in the Grignard reaction. The advantages are it is comparatively inexpensive, it can be handled without excessive loss due to evaporation, simple distillation gives an ether free from moisture and alcohol, and the vapour does not form explosive mixtures with air. n-Butyl ether cannot, of course, be employed when the boiling point of the neutral reaction product is close to 140°. 

Most adsorption systems use stationary-bed adsorbers. However, efforts have been made over the years to develop moving-bed adsorption processes in which the adsorbent is moved from an adsorption chamber to another chamber for regeneration, with countercurrent contacting of gases with the adsorbents in each chamber. Union Oil s Hypersorption Process (90) is an example. However, this process proved uneconomical, primarily because of excessive losses resulting from adsorbent attrition. 

Another possibiUty is to enclose only the working, top part of the horizontal belt in a pressure vessel and pass the belt through the sides of the vessel. The operation must be intermittent because the belt cannot be dragged over the support surface with the pressure on, and the entrance and exit ports for the belt must be sealed during operation to prevent excessive losses of air. The movement of the belt is intermittent and is synchronized with decompression in the vessel therefore, the entire vessel volume must be depressurized in every cycle and this is wasteful. There is also an inevitable downtime. There are no problems with discharging the cake because this is done at atmospheric pressure. 

It should be noted that a significant increase in ammonia supply could be achieved by improving the on-stream efficiency of plants and avoiding excessive losses throughout the downstream conversion and distribution processes. 

Liquid-phase chlorination of butadiene in hydroxyhc or other polar solvents can be quite compHcated in kinetics and lead to extensive formation of by-products that involve the solvent. In nonpolar solvents the reaction can be either free radical or polar in nature (20). The free-radical process results in excessive losses to tetrachlorobutanes if near-stoichiometric ratios of reactants ate used or polymer if excess of butadiene is used. The "ionic" reaction, if a small amount of air is used to inhibit free radicals, can be quite slow in a highly purified system but is accelerated by small traces of practically any polar impurity. Pyridine, dipolar aptotic solvents, and oil-soluble ammonium chlorides have been used to improve the reaction (21). As a commercial process, the use of a solvent requites that the products must be separated from solvent as well as from each other and the excess butadiene which is used, but high yields of the desired products can be obtained without formation of polymer at higher butadiene to chlorine ratio. 

Fixed-roof atmospheric tanks require vents to prevent pressure changes which would othei wise result from temperature changes and withdrawal or addition of liquid. API Standard 2000, Venting Atmospheric and Low Pressure Storage Tanks, gives practical rules for vent design. The principles of this standard can be applied to fluids other than petroleum products. Excessive losses of volatile liquids, particularly those with flash points below 38°C (100°F), may result from the use of open vents on fixed-roof tanks. Sometimes vents are manifolded and led to a vent tank, or the vapor may be extracted by a recov-eiy system. 

In general, tollers should have active insurance policies that protect themselves and to a certain extent the client from excessive loss. Make certain that the insurance coverage held by both parties works well to manage risks. 

The addition of water is accompanied by foaming, and care must be taken to avoid excessive loss of the solvent. 

Cold stress Physiological stress on the body created by excessive loss of body heat. 

In a toroidal traction drive, toroidal input and output disks face one another, separated by a number of rollers that contact the toroid surfaces. The rollers are mounted so that they can he tilted to vaiy the radius from the centerline of the disks where they contact the toroids, and therefore determine the input/output speed ratio of the rotating disks. A substantial axial force must be applied to the disks to prevent the rollers from slipping on the disk surfaces. To avoid excessive losses when the torque transmitted is low, this force needs to he modulated in proportion to the torque transmitted. 

The relation between free phosphoric acid content and total phosphate content in a processing bath, whether based on iron, manganese or zinc, is very important this relation is generally referred to as the acid ratio. An excess of free acid will retard the dissociation of the primary and secondary phosphates and hinder the deposition of the tertiary phosphate coating sometimes excessive loss of metal takes place and the coating is loose and powdery. When the free acid content is too low, dissociation of phosphates (equations 15.2, 15.3 and 15.4) takes place in the solution as well as at the metal/solution interface and leads to precipitation of insoluble phosphates as sludge. The free acid content is usually determined by titrating with sodium... 

Secondary hypokalemic paralysis can be caused by almost any event that causes excessive loss. One particularly interesting secondary condition, however, is thyrotoxic periodic paralysis, seen most commonly in Chinese patients. 

Attention to iron metabolism is particularly important in women for the reason mentioned above. Additionally, in pregnancy, allowances must be made for the growing fetus. Older people with poor dietary habits ( tea and toasters ) may develop iron deficiency. Iron deficiency anemia due to inadequate intake, inadequate utilization, or excessive loss of iron is one of the most prevalent conditions seen in medical practice. 

Iron deficiency anemia Inadequate intake or excessive loss of iron... 

Respiratory alkalosis Alkalosis caused by excessive loss of carbon dioxide due to a respiratory abnormality (e.g., hyperventilation). 

Although Averell and Norris (1) suggest that the final evaporation of the last 10 ml. be accomplished with the aid of a jet of air at room temperature, so as to avoid excessive losses of parathion, the apparatus shown in Figure 7 accomplishes the final evaporation without such excessive losses. This conclusion is supported by the data in Table IV, with losses of about 20% in all cases. Data for both acetone and benzene are again included to re-emphasize the interchangeability of the two solvents for this utility. The two... 

Reduction of Parathion. This reduction is carried out in the same kind of bottle and in the same bath as shown in Figure 7. Such a tall bottle, in contrast to a beaker or short flask, maintains reflux conditions and thus prevents excessive losses of alcohol. As indicated by Averell and Norris (1) and verified by the authors, this procedure will reduce quantitatively several milligrams of parathion in the time specified. Ordinarily six reductions are carried on simultaneously. 

This study investigates the retention behavior of dilute polymer solutions in oil sands. Results indicate that the presence of a large amount of fines and/or a variety of minerals in the sand may result in high adsorption and retention causing excessive loss of polymer and high injection pressures. Injection of a surfactant with the polymer leads to increased oil recoveries because the dilute polymer may selectively adsorb on mineral grain surfaces leaving the surfactant to act at liquid/iiquid contacts. 

Natural resins are substances with a high viscosity, semisolids or solid and insoluble in water. They are formed in the so-called resiniferous canals of several trees. Many varieties of plants spontaneously exude resins as a product of their metabolism, to protect themselves against excessive loss of water and attack from micro-organisms. 

The following operations should be done using standard safety procedures for working with radioactive compounds. All steps involving SASD prior to initiation of the photoreaction should be done protected from light to avoid loss of phenyl azide activity. The radiolabeling procedure should be done quickly to prevent excessive loss of NHS ester activity due to hydrolysis. 

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