摘要:

AbstractThe impulse‐rendering process, which consists in mechanical rupturing of membranes of fat‐containing cells by high‐speed impulses transmitted through the medium of a liquid, has been developed mainly for degreasing animal by‐products in such a way as to preserve the quality of the fat and protein. The degreasing of bone and soft fat is described in detail, and brief reference is made to possible applications in the recovery of oils from fish, fish livers, vegetable fruits an

ISSN:0021-8871    

DOI:10.1002/jctb.5010031202

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractThe mechanism of rubber hydrochlorination is discussed in the light of the known crystal structure of rubber hydrochloride. The coiling of a rubber chain segment into atrans‐decalin‐shaped transition state is shown to be necessary and sufficient to explain the alternation along the polymer chain of D‐and L‐asymmetric carbon atoms, each separated from the next by three CH2groups. As a preliminary to kinetic analysis, techniques are described for precise measurements on the degree of hydrochlorination of latex at various times of reaction. An analytical technique defines the reaction progress to 0·5%, and serves to calibrate a diffusion‐gradient method of following the reaction by density change. This method is at least equally sensitive, but more convenient. Despite the complexity of the natural latex medium, the reaction kinetics are shown to be reproducible and free from uncontrolled effects. The reaction is rate‐controlled chemically rather than by transport. The main part of the rate curve consists of two straight‐line (zero‐order) portions m

ISSN:0021-8871    

DOI:10.1002/jctb.5010031203

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractDuring experiments on the behaviour of galvanized steel in sodium benzoate solution, it was found that bare steel edges rusted heavily. Electrochemical measurements showed that, in certain circumstances, steel became anodic to zinc. Possible reasons for this behaviour are discussed.

ISSN:0021-8871    

DOI:10.1002/jctb.5010031204

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractGels were prepared by adding sodium silicate solution to sulphuric acid until a certain pH was reached, and then the products were aged, washed and dried under controlled conditions. The surface properties of the dry gels were studied by measuring adsorption isotherms of nitrogen at – 195·8° and nitrous oxide at — 78·5°. The pH reached came within the range 3·7–5·8, as this corresponded to a decrease in setting time from over an hour to a few seconds. For gels prepared over this pH range, the isotherms of the two gases also changed profoundly, both sets showing the same general pattern. In one preparation the temperature was varied, and in another the ageing period was reduced to the minimum; in neither case could any difference in the adsorption of nitrous oxide be detected. Activation, by soaking in very dilute sulphuric acid, was shown to be more important for a gel prepared at the higher‐pH end of the range.Surface areas have been calculated from both sets of isotherms by the Brunauer, Emmett and Teller (B.E.T.) method. Good agreement is obtained, in some cases, by assuming that each nitrous oxide molecule occupies an area of 20·4 Å2in the close‐packed monolayer, and taking the usual value of 16·2 Å2for the nitrogen molecule. The values of residual water content and B.E.T. surface area both decreased substantially over the pH range, but there appears to be no simple relati

ISSN:0021-8871    

DOI:10.1002/jctb.5010031205

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractSamples of water containing less than 8% of the normal quantity of H218O have been prepared by distillation in a 40‐ft. packed column, and oxygen made from them has been analysed by the mass spectrograph. From the results it has been calculated that the density of H216O at 25° is 262·4 ± 2 p.p.m. less than that of normal water. From this figure it has been deduced that the ratio of the density of H218O to that of normal water is 1·1134± 0·001, and it is very probable that the corresponding figure for H217O is 1·0577. The electrolytic fractionation factor for18O has been found to be 1·03. The distillation fractionation factor for H218O and H216O at 100° is almost certainly greater than 1·0045 and is probably 1·0056; for H217O it is probably 1·0028. It has been found that the ratio H218O:H217O in light‐water samples of the same density, obtained by distillation, does not vary greatly, so that their composition may be determined from thei

ISSN:0021-8871    

DOI:10.1002/jctb.5010031206

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010031207

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010031201

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY