Relationship between tolerance

In the next chapter, we introduce the concepts of component manufacturing capability and the relationships between tolerance, variability and cost. The Component Manufacturing Variability Risks Analysis is then introduced, the first stage of the CA methodology, from which process capability estimates can be determined at the design stage. The development of the knowledge and indices used in the analysis... 

It must be emphasized that the relationship between tolerance, physical dependence and compulsive drug use is complex and depends both on the category of drug and the personality of the abuser. For example, it appears that the majority of patients prescribed benzodiazepines for periods of many months experience relatively minor withdrawal symptoms when the drugs are abruptly stopped. Others, however, experience severe anxiety states and have extreme difficulty in stopping the drug. 

Figure 1. Relationship between tolerance distribution and dose-response curve.

Relationship Between Tolerances and Actual Daily Intake of Pesticides" FA0/WH0 Food Standards Programme, World Health Organization, Geneva, 1974. 

TABLES. Relationship between tolerance limits and number of molecules retrieved from the CAVEAT intra database. 

Variation is an obvious measure for quality of conformance, but it must be associated with the requirements set by the specification to be of value at the design stage. Unfortunately, difficulty exists in finding the exact relationship between product tolerance and variability. Approximate relationships can be found by using process capability indices, quality metrics which are interrelated with manufacturing cost and tolerance (Lin et al., 1997). ... 

The data used to generate the maps is taken from a simple statistical analysis of the manufacturing process and is based on an assumption that the result will follow a Normal distribution. A number of component characteristics (for example, a length or diameter) are measured and the achievable tolerance at different conformance levels is calculated. This is repeated at different characteristic sizes to build up a relationship between the characteristic dimension and achievable tolerance for the manufacture process. Both the material and geometry of the component to be manufactured are considered to be ideal, that is, the material properties are in specification, and there are no geometric features that create excessive variability or which are on the limit of processing feasibility. Standard practices should be used when manufacturing the test components and it is recommended that a number of different operators contribute to the results. 

The critical characteristic on each component was analysed, calculated from the analysis and the value obtained was plotted against the process capability indices, Cpk and Cp, for the characteristic in question. See Appendix V for descriptions of the 21 components analysed, including the values of Cp and Cp from the SPC data supplied. Note that some components studied have a zero process capability index. This is a default value given if the process capability index calculated from the SPC data had a mean outside either one of the tolerance limits, which was the case for some of the components submitted. Although it is recognized that negative process capability indices are used for the aim of process improvement, they have little use in the analyses here. A correlation between positive values (or values which are at least within the tolerance limits) will yield a more deterministic relationship between design capability and estimated process capability. 

Note that the squared relationship which was initially used to model the degree of difficulty in obtaining more capable tolerances for a given manufacturing route and product design is being returned by the power law. Similarly, a relationship between the process capability index Cp and q for the components analysed is shown in... 

Check the toxicity of process materials, identify short and long term effects for various modes of entry into the body and different exposure tolerance Identify the relationship between odour and toxicity for all process materials Determine the means for industrial hygiene recognition, evaluation and control Determine relevant physical properties of process materials under all process conditions, check source and reliability of data... 

These considerations lead to the conclusion that the relationship between corrosion and deterioration of properties of a metal is highly complex, and involves a consideration of a variety of factors such as the rate and form of corrosion and the specific function of the metal concerned certain forms of corrosion such as uniform attack can be tolerated, whereas others such as pitting and stress corrosion cracking that ultimately lead to complete loss of function, cannot. 

For future research in this field, in addition to physiological and biochemical approaches, genetic analysis will be essential in the establishment of causal relationships between the induction of a stress protein and the establishment of tolerance to the stress condition. In most cases it is not difficult to detect the induction of new proteins during stress. However, the induction of new proteins does not necessarily establish stress tolerance it may well be the consequence of damage caused by stress conditions. Thus, genetic mutants will be necessary to test the physiological role of a stress protein. 

Plant cells selected for tolerance to stress show varied responses to the imposed osmotic gradients. In adapted cells, tolerance to salinity or to water stress was not found to increase proportionately with increases in turgor (Handa et al., 1983 Binzel et al., 1985). It was suggested from these observations and from studies by Heyser Nabors (1981) that no relationship existed between turgor and growth and that stress adaptation may alter the relationship between turgor and cell expansion (see also Chapter 6). 

Ben-Hayyim, G. (1987). Relationship between salt tolerance and resistance to polyethylene glycol-induced water stress in cultured citrus cells. Plant Physiology, 85, 430-4. 

Individual ability to tolerate radiation damage varies, so a statistical variation exists in the relationship between dose level and health effects. Also, there are effective treatments, such as blood transfusions, for some radiation effects. The statistical patterns of human response to radiation are summarized in Table 22-5. Doses of over 600 rem are almost always fatal. 

Freeman, A.S. Martin, B.R. and Balster, R.F. Relationship between the development of behavioral tolerance and the biodisposition of phencyclidine in mice. Pharmacol Biochem Behav 20 373-377, 1984. 

The first priority when caring for patients with an allergic reaction is to avoid doing serious harm by administering a drug that the patient cannot tolerate. We can establish the likelihood of a relationship between the suspected drug and... 

The initial dose of allopurinol is based on the patient s renal function. Patients with creatinine clearances of 50 mL/minute or less should receive a starting dose of less than 300 mg/day to minimize adverse effects. The relationship between dose of allopurinol and its most severe side effects is controversial. However, the dose can be adjusted upward as needed and tolerated. It is reasonable to reduce the dose temporarily in patients who develop reversible acute renal failure. 

Deitrich RA, Bludeau P, Erwin VG. Phenotypic and genotypic relationships between ethanol tolerance and sensitivity in mice selectively bred for initial sensitivity to ethanol (SS and LS) or development of acute tolerance (HAFT and LAFT). Alcohol Clin Exp Res 2000 24(5) 595—604. 

Chung, S-J., Fung, H-L., Relationship between nitroglycerin-induced vascular relaxation and nitric oxide production. Probes with inhibitors and tolerance development. Biochem. Pharmacol. 45 (1993), p. 157-163... 

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