ISSN:0021-8871    

DOI:10.1002/jctb.5010150707

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractA mixture of 0.2% sodium nitrite and 0.8% hydrated disodium hydrogen phosphate in 40% glycerine is effective in preventing the corrosion of steel and copper over a much wider pH range than is possible with either inhibitor alone. In an unusually severe laboratory test involving oxygen under 500 p.s.i. pressure at 205°F, this inhibitor combination was much superior to triethanolamine phosphate with sodium mercaptobenzothiazole and superior to sodium benzoate with sodium nitrite. It was little affected by 100 p.p.m. of the fungicide dichlorophen, but larger concentrations caused a serious reduction in corrosion‐preventing properties in the laboratory test. The laboratory test indicates that use of ethylene glycol in place of glycerine with the nitrite‐phosphate inhibitor combination would be a considerable improve

ISSN:0021-8871    

DOI:10.1002/jctb.5010150701

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractIt has been shown that the introduction of a few stable crosslinks into the skin protein can greatly increase the resistance of the leather to deterioration by moist heat and perspiration.A method based on stress‐strain measurements has been developed for the determination of the number of crosslinks introduced into collagen, and a study made of the crosslinking potentialities of a number of bifunctional and polyfunctional compounds. Aldehydes appear to be most promising, cyanuric chloride and its derivatives also offer possibilities, while di‐isocyanates are relatively inefficient due mainly to their low solubility in and sensitivity to water. Of the aldehydes, glutaraldehyde and acrolein were the most efficient both with respect to the number of crosslinks introduced and their stability.Leathers tanned with glutaraldehyde show good resistance in moist heat and perspiration tests and pretannage or retannage of chrome leather with this aldehyde greatly improves its resista

ISSN:0021-8871    

DOI:10.1002/jctb.5010150702

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractThe importance has been assessed of various factors responsible for the release of corrosive vapours from certain freshly‐felled hardwood and softwood species on exposure to high humidity and temperatures in excess of 30°. Variables studied include (i) season of felling, (ii) differences between sapwood and heartwood regions, (iii) initial acid content of the timber on felling, (iv) rǒle of non‐volatile extractive components in catalysing release of corrosive vapours and (v) inhibition of enzymic reactions by mild chemical sterilisation. Although the release of volatile acid is closely related to the loss of bound acetyl groups from the wood substance, indicating autohydrolysis of acetate in the cell wall material, the vapour corrosivity of a timber species is not directly related to its bound acetyl content. The presence of very small free acetic acid contents (0.01—0.03%) in some freshly‐felled undried woods is shown to play a significant rǒle in promoting rapid release of corrosive vapours by the woods (e.g., sweet chestnut and oak). Sterilisation of sweet chestnut and oak with propylene oxide vapour at ambient temperatures markedly reduces, but does not completely eliminate, release of corrosive vapours by these woods. An accompanying reduction in the proportion of bound acetate groups hydrolysed in the cell wall substance may indicate that the release of volatile acidic products from wood is in part due to a microbiological hydrolysis as well as chemical

ISSN:0021-8871    

DOI:10.1002/jctb.5010150703

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractThe reaction of 3CaO,Al2O3with water in the presence of CaSO4,2H2O is investigated in suspensions and in pastes. In both, essentially the same sequence of reactions is found, the hydration products being (in the order of their appearance) ettringite, hydrous alumina, calcium aluminate hydrate monosulphate, and sulphate‐free hexagonal aluminate hydrates. In pastes, indications of water transport as an important factor in determining the reaction rate are found. Acceleration of the reaction after consumption of most of the sulphate ions present is probably due to chemical conversion of a retarding hydrate laye

ISSN:0021-8871    

DOI:10.1002/jctb.5010150704

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractThe corrosion of mild‐steel tubing by high‐purity water flowing at velocities up to 400 ft./min. and at temperatures of 25, 40 and 55° has been studied over periods of 1–10 weeks. The extent of attack was measured quantitatively from changes in weight of the tube specimens and qualitatively by visual examination and photography. The composition of the corrosion products was elucidated by X‐ray powder diffraction.The rate of attack,k1, increased with flow velocity,v, up to a maximum at about 200 ft./min. according to an expression of the formThe rate of attack fell on further increase of flow velocity and at 300 and 400 ft./min.,k1did not differ significantly from its value at 2.4 ft./min.The low values for the activation energies confirm that the corrosion reaction is controlled entirely by the rate of diffusion of oxygen to the metal surface at low flow velocities. At higher temperatures there are indications that both the rate of diffusion and the rate of cathodic reduction of oxygen are involved.The amount of goethite, α‐FeOOH, in the corrosion product increased with flow velocity, which was indicative of the higher rate of oxidation of the ferrous ion initially formed. The decrease in corrosion rate at the highest flow velocities is attributed to the formation by this oxide of a more protective ba

ISSN:0021-8871    

DOI:10.1002/jctb.5010150705

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractThe reduction of pure stannic oxide by direct mixing with mazut (a petroleum product) in the presence of lime and water, is studied for various paste compositions. It is found that a paste of the oxide 68—70%, mazut 20%, lime 4—6% and water 4—6%, can be almost completely (>94%) reduced. The extent of reduction increases slightly with decrease of particle size. Cassiterite fines were similarly reduced under conditions in which were varied (i) the starting temperature of heating; (ii) the duration of heating; (iii) the atmosphere in the reduction process; and (iv) the maximum temperature of heating. Complete reduction (94.3%) was obtained with a paste composed of cassiterite fines (<0.2 mm. mesh size) 82%, mazut 14%, lime 2% and water 2% by thermal treatment for 5 min. in a mazut vapour atmosphere and a maximum temperature of 1000°. Complete reduction was readily obtained with any starting temperature of heating between room temperature an

ISSN:0021-8871    

DOI:10.1002/jctb.5010150706

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY