Special cause problems

Do attract management s attention to special cause problems and obtain commitment to action. 

Do classify the problems into groups that have a common cause and special cause. 

A surprisingly low concentration of water can reduce the viscosity such that reclaimed PET cannot be used for the blow molding of bottles with acceptable physical properties. The established solution to the moisture problem is to dry the recycled PET in special dryers prior to use. However, the drying process is both time and energy intensive. Paper labels can cause problems in PET recycling if they decompose during washing and removal. The paper fibers formed can produce cellulose fibers that are difficult to remove from the reprocessed PET.1... 

When a-sulfo fatty acid esters are used as the major active component in detergents they can cause problems because of their foaming properties. In European horizontal drum-type automatic washers they produce too much foam, and in the rinse cycle of the American and Japanese pulsator-type washers the foam cannot be completely rinsed out [38]. The problem of inefficient rinsing can be solved by the addition of soap [63] or sulfonated unsaturated fatty acid esters [64]. For European applications special foam inhibitors are needed. 

The laboratory operator must make a careful examination of all wastes that will be generated and, from this, work up a waste disposal system. Some wastes may be compatible and could be disposed of together. Others could react and thus cause problems. Flammables must be given special attention. Certain biological wastes may be very hazardous even in small quantities. Special rules apply to radioactive materials, even in the small amounts used for investigative purposes. 

Temperature and relative humidity cause problems because they are difficult to control except when special equipment is used. The variation depends on the weather and the quality of the climate control, but they do vary. Their effect on the retention is different for different solutes. Therefore the resolution can change. 

The methanation reaction is a highly exothermic process (AH = —49.2 kcal/ mol). The high reaction heat does not cause problems in the purification of hydrogen for ammonia synthesis since only low amounts of residual CO is involved. In methanation of synthesis gas, however, specially designed reactors, cooling systems and highly diluted reactants must be applied. In adiabatic operation less than 3% of CO is allowed in the feed.214 Temperature control is also important to prevent carbon deposition and catalyst sintering. The mechanism of methanation is believed to follow the same pathway as that of Fischer-Tropsch synthesis. 

It has been known for many years, however, that the (3-branched amino acids, especially valine and isoleucine, cause problems in synthesis,14,5] and special care and additional reaction time are required when -substituted amino acids are added to a growing peptide chain in synthesis. For example, in the synthesis of [2,4-diisoleucine]oxytocin efforts to couple the isoleucine to isoleucine by the azide method failed and only the rearranged product was obtained 61 Also, it is much more difficult to hydrolyze peptide bonds formed between two or more contiguous -substituted amino adds using standard 6M HC1 conditions. For example, in the hydrolysis of [2,4-diisoleucine]oxytocin (3 isoleucine residues adjacent to each other) complete hydrolysis takes 60 hours. 

The practical problems associated with Norplant have related to its physical form rather than its pharmacological profile. Practitioners specially trained in the insertion and removal of the device usually handle it without major problems, but without this special instruction it can be difficult to ensure that the rods are properly placed and that they are removed without scarring or other complications. Even given appropriate handling, the rods can cause problems as a result of migration or breakage in situ. 

Note The treatment of mycobacterial infections has become an even more important and challenging problem because of the emergence of multiple-drug-resistant organisms and because of the acquired immunodeficiency syndrome (AIDS) pandemic, which has been associated with a marked increase in tuberculosis and infection caused by the M. avium complex. Because the microorganisms grow slowly and the diseases often are chronic, patient compliance, drug toxicity, and the development of microbial resistance present special therapeutic problems. 

There have been attempts to develop special methods for some elements which cause problems with solvent analysis when using the flame or furnace atomiser techniques. 

Avoiding the water-rich region, where the special structure of water may cause problems, consider the B coefficient at x2 = 1/2, 2/3, and 1. From previous work we have... 

In general, activation analysis relies on the use of standards that are irradiated under the same conditions and in the same position, and are also measured under the same conditions. Monoelement standards contain a known amount of one element. If they are applied to the evaluation of other elements the ratio of the cross sections o x/o s under the special conditions of irradiation and the ratio H /Hs of the relative abundances of the decay processes that are measured must be known (subscript x is for the sample and subscript s for the standard). Knowledge of the ratio o x/o s may cause problems, because the cross sections may vary drastically with the energy of the projectiles, for instance in the energy range of epithermal neutrons. These problems are not encountered with multielement standards that contain all the elements to be determined. However, the preparation of such multielement standards may be time-consuming. 

Bleeding. Discoloration caused by migration of components from the underlying film. Substrates that can cause problems are those coated with tar- or bitumen-based materials, paints made on certain red and yellow organic pigments (which are partially soluble in solvent), some wallpapers, and timber stains that contain soluble dyes. The remedy is to use a specially formulated sealer or an aluminum paint. 

Most biopolymers are produced as extracellular metabolites by fermentation in bioreactors leading to special technical problems caused by the very viscous solutions that make mass transfer and mixing in the fermentation fluids difficult. Large volumes of water and solvents are needed for dilution and extraction, respectively. 

A special stability problem was studied by Yakhnin et al. [12,13] for cross-flow moving-bed reactors. The instability here is caused by the differential flow between heat acting as autocatalyst and the reacting matter at elevated Lewis numbers. The cross flow removes the system from equilibrium all along the reactor and thereby furthers the occurrence of instabilities. The study is purely theoretical without any experimental verification for the present. 

During Phase III, the process is monitored for instances of special causes. When special causes cannot be entirely eliminated, an Out-of-Control Action Plan (OCAP) can be developed for routine use by operating personnel.The OCAP comprises three features activators, checkpoints, and terminators. The activators define the conditions that signal when the OCAP must be activated, and the control chart usually performs this function. The checkpoints instruct the operator to investigate specific items as possible special causes for the out-of-control condition. Once a checkpoint has been identified as a special cause, a terminator caih for a specific action to be applied to resolve the problem. 

Using X-ray diffraction general radiation damage is easily observable. In the special case of ion implantation the small penetration compared with the total thickness of the target causes problems. One either has to use the technique of thin layer X-ray diffraction where the information depth is < lO A or to restrict the investigation to ion-bombarded thin films. 

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