The Reasons for Failure

The causes of low pressure, for example, could be cither hydraulic or mechanical. In many cases of failure analysis, asking Wliy. and Wliat and answering those questions, until you can no longer ask why , will almost always get you to the answer. If all evidence leads to a mechanical reason for the failure, the problem is probably maintenance induced. If the evidence leads to a hydraulic reason for the failure, the problem is eitJier operations or design induced. In cases where the reason for failure was not determined, a more extensive analysis is necessary. The additional analysis is recommended to take advantage of the pump supplier experience in identifying the root cause. 

A pilot project generally ensures the complete project is implemented smoothly and a clear understanding of the value of the project is established. Of course, a failure at the pilot stage can lead to cancellation of the overall project. If the pilot is not successful, it is important to analyze the reasons for failure so that any decision to continue or abandon the integration is made rationally. 

It practice it is usually difficult to establish the reasons for failure as a number of factors may be simultaneously responsible, such as (n) application of the protective to dirty surfaces, (b) carelessness in application, (c) inherent inadequacy of the material, (rf) exposure to unreasonably severe conditions, (e) inevitable difficulties in application. Point (c) includes inadequacy not only in protective properties but, in the case of the hard-film materials, in certain physical properties, e.g. the film may become brittle and flake when handled, may remain too sticky and become contaminated with dirt or adhere to the... 

It can sometimes be very difficult to obtain an overview of the reasons for failure. 

Thus, if the planner fails to come up with a feasible plan, and the reason for failure is that no ASVS was found, the preceding algorithm may be used to propose flowsheet modifications (in the form of extra valves) to create an appropriate ASVS. 

Figure 3.11 Failure of drug molecules. Many drugs that are successful in the pharmacodynamic phase ultimately fail to become useful drugs. This pie-chart presents the reasons for failure at this stage of the development process. Toxicity is an important cause of failure.

Appropriate qualified staff must study the results to identify the reason for failure, which may not be due to the facilities or operations under test, but instead due to ... 

When things go wrong we often do not know why. If we did we probably would have stopped it happening. Hence, we may also test to fathom out the reasons for failure. 

Secondly, the description of the general procedures given below, as distinct from the specific experimental procedures of the preparations described in earlier chapters, provides an excellent opportunity for the student to explore on the small scale the optimum reaction conditions, the chromatographic monitoring of the reaction, the methods of isolation and purification procedures (solvent extraction, recrystallisation, etc.) for the successful completion of the preparation. The small-scale nature of the experiments is of particular importance in providing experience of those techniques of reaction work-up in which mechanical loss is frequently the reason for failure. Such experience is vital to the synthetic chemist since many of the new chemo-, regio- and stereo-specific reagents are expensive and used in small-scale reactions. 

Analytical studies of the PVC profile surface indicated that the reasons for failure of the adhesive bond between the PVC film and PVC profile in decorative film laminated structures, was finely dispersed lubricant and wax particles on the PVC profile. These contaminants prevented the build-up of bond forces at the interface between the adhesive and PVC profile. A biodegradable alkaline cleaning agent was developed to remove the contaminants, which, when combined with flame treatment and a solvent free polyurethane hot melt... 

White Test failed (a written message may be added giving the reason for failure)... 

Jordan and Russell 1989). Sioli (1973) believed that the reluctance of administrators to mention poor soils as the reason for failure of Amazonian projects. Jari was their faith in the myth of the Amazon as a source of unbridled productivity. 

One recourse is to use low-destructive test methods that can quantify the efficacy of protective agents [27] and provide evidence of improper use or application of the silicone [4, 15, 27, 28, 32, 36, 37], High-resolution microscopy would offer the advantage of visualizing the reasons for failure of hydrophobic treatments just after application, before they became visible very much later when the weathered materials started to fail [38, 39]. Weak areas such as inadequate uptake of the treatment, poor penetration depth, and incompleteness of coating could be documented just after the masonry treatment had been applied. 

India s modern steel industry is about 75 yr old. The first fully successful iron and steel mill was established in 1907 by Jamshedji Tata. There were as many as 17 earlier unsuccessful attempts to establish Indian ironworks using Western-type technology. Some of the reasons for failure were as follows ... 

The importance of spacers and all techniques to improve delivery is relative. If the dose delivered the old way achieves maximum pharmacodynamic effect, improving delivery is moot [53]. This observation raises other questions about aerosol drug delivery, namely, the effective dose. It is likely that the dose overkill concept has been the reason for failure to show differences when some applications were compared. A new, refined device may not be more effective than an older one because the older one delivers such a large dose that, despite inefficiency, it is pharmacodynamically equivalent. At least one study shows no difference in protection from exercise-induced asthma by nedocromil sodium and by sodium cromoglycate via MDI, and use of a spacer did not change results [54]. 

Cumulative standard curve and quality control (QC) data tables containing appropriate statistical parameters should be generated and included with the study sample values in the final study report. Additional documentation with respect to the failed runs, dates of these mns, and the reason for failure should be documented. All deviations, impact to the study results, and supporting data should also be included in the final report. 

Process design and scale-up always carry risk, and the reasons for failure are often tedious to work out. Although it is clear that answering the above questions may not overcome all problems and risks in industrial practice, doing so with a solid understanding of the characteristics of the drug substance to be crystallized should help to minimize these risks. 

Biochemical in vitro screening may deliver compounds that despite a clear target activity cannot exhibit in vivo activity due to, for example, unfavorable physicochemical properties (lacking bioavailability), fast metabolization, insufficient stability, or poor distribution in the target organism. Nevertheless, these chemical classes are of interest to chemists, because these properties are characteristics of compounds that in principle can be overcome by chemical optimization. Agro -kinetics has identified pure in vitro hits as such and helped to elucidate the reasons for failure in an in vivo test, thus guiding the in vitro to in vivo transfer of hit classes. 

It is. of course possible to analyze the reasons for failure of a crystal structure predietion study using the experimental strueture. The seareh is inadequate if it does not find the minimum obtained starting from the experimental structure, using the same force field. If this... 

Some corrosion wear effect was associated, as a rule, with deterioration of a primary water chemistry condition (as compared to a specified one). In particular, the fact that steam generators were operated with excessive salt content in feed water, that could be the reason for failures of some steamgenerating tubes and other items of SGs. As a result of irradiation of reactor internals, an increase in... 

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