Hoar report

The overall design process depends on the use of codes of practice and specifications, and to an increasing extent on computer-based techniques. The potential cost of delay is therefore a strong incentive to the use of standard solutions, compatible with the codes of practice , and to develop ways of using the computer to provide corrosion information and knowledge, or to improve prediction of corrosion behaviour. Note that both points relate to the use of existing knowledge, in the sense of an important conclusion of the Hoar Report. ... 

London (1971). An independent corrosion survey by P. Elliot, supplement to Chem. Engr. No. 265, Sept. (1973), substantiates the findings of the Hoar report. 

The three most important findings of the Hoar report were the following ... 

The Hoar report determined the cost of corrosion for the industry sectors of the economy (2). The cost of corrosion for each industry sector was added together to arrive at the cost of corrosion for the entire UK economy. The report identified the sources for the cost of corrosion by sectors of the economy. It evaluated and summarized the direct expenditures (costs to owner/operator) in each economic sector. Indirect costs (costs for user) were not included in the studies. 

Avoidable corrosion costs The Hoar report estimated that nearly 20-25% of the total corrosion costs could be saved by better use of current knowledge of corrosion control. For each industry, the percentage savings ranged from approximately 10% to 40% of the industry s corrosion costs. 

Some examples that highlight the conclusions of the Hoar Report are as follows. 

TP Hoar, Report of the Committee on Corrosion Protection a Survey of Corrosion Protection in the United Kingdom, 1971. 

In contrast to the traditional scientific mechanistic approach, systems engineers prefer the "top>-down" approach that broadens the definition of the system and is more likely to include causes of corrosion failures such as human behavior. This is consistent with the lessons to be learned from the U.K. Hoar Report, which stated that corrosion control of even small components could result in major cost savings because of the effect on systems rather than just the components [2]. 

R. G. Stewart, G. V. Barker, P. E. ChisnaU, andj. L. Hoare, WRONZ Report No. 25, Wool Research Organisation of New Zealand, Inc., Christchurch, New Zealand, 1974. 

H NMR data has been reported for the ethylzinc complex, Zn(TPP—NMe)Et, formed from the reaction of free-base N-methyl porphyrin H(TPP—NMe) with ZnEti. The ethyl proton chemical shifts are observed upheld, evidence that the ethyl group is coordinated to zinc near the center of the porphyrin. The complex is stable under N2 in the dark, but decomposed by a radical mechanism in visible light.The complex reacted with hindered phenols (HOAr) when irradiated with visible light to give ethane and the aryloxo complexes Zn(TPP—NMe)OAr. The reaction of Zn(TPP—NMe)Et, a secondary amine (HNEt2) and CO2 gave zinc carbamate complexes, for example Zn(TPP—NMclOiCNEti."" ... 

An interesting phenomenon in water-oil-amphiphile systems is the presence of self-assembled arrays of amphiphiles (surfactants) called micelles. From 1948 to 1950, Philip Alan Winsor reported that upon simple mixing (i.e., without the need for high shear conditions), oil, water, and amphiphiles yielded clear, macro-scopically homogeneous single phases which he termed type IV systems (Winsor, 1948, 1950). The term microemulsion was introduced later by Jack H. Shulman, a Columbia University chemistry professor, to denote these thermodynamically stable optically isotropic, transparent oil-water-amphiphile dispersions (Shulman et al., 1959). Type IV systems contain small droplets of one liquid dispersed within the other, with a self-assembled layer of surfactant molecules (micelles) along the interface between the two phases. The spontaneous self-assembly of the micelle is driven by the thermodynamic tendency to minimize the surface tension between the water and the oil in the presence of the amphiphile (Hoar and Shulman, 1943). 

Three papers have been published recently which attempt to describe the underlying physical mechanisms for the peculiar behavior in the simulated phase changes. Amar and Berry have recently applied the steepest-descent quench technique to the study of the melting transition in tt. The four isomers reported by Hoare and for Af = 7 were observed in the... 

For each cluster size n an initial configuration was chosen to match the minimum energy structure reported by Hoare and Pal. For the classical internal energy approximately 100,000 Monte Carlo moves were made, followed by approximately 1 million moves where data were accumulated in the evaluation of the energy. The constraining radius required to evaluate Eq. (3.1) was taken to be 3a for 2-, 3-, ad 4-particle clusters, 4cluster sizes from 5 to 16, and 5a for cluster sizes from 17 to 20. As shown by Lee, Barker, and Abraham, the calculated free energies are insensitive to the choice of... 

An alternative method of data reduction was reported early in the history of gas chromatography by Hoare and Purnell (12-15 see refs. 16,17 for recent applications), who considered the dependence oTffie specific retention volume on the solute saturation vapor pressure pA. Thus, taking the view [now recognized to be naive (18) see later], that the observed mole fraction-based solute activity coefficient" can be decomposed into "athermal" and "thermal" components (19-22) v v-... 

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