摘要:

AbstractA survey (is presented) of the work of the Corrosion Research Section of Chemical Research Laboratory (Department of Scientific and Industrial Research), Teddington, since 1939. The topics discussed include the “high‐speed rotor apparatus” for accelerated immersed corrosion tests; the investigation of high‐duty coatings; antifreeze solutions; corrosion inhibitors for use in heat‐exchange systems, de‐icing systems, wrapping materials, enclosed air spaces; accelerated atmospheric corrosion tests; methods of pre‐treatment; bituminous coatings; microbiological (soil) corrosion; miscellaneous investigations and informa

ISSN:0368-4075    

DOI:10.1002/jctb.5000660501

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractThe quantitative determination of the % of amylose and amylo‐pectin in starches and starch fractions is best carried out using a low starch: iodine ratio. The use of a high starch: iodine ratio is undesirable, since it may not reveal differences in the amylose : amylo‐pectin ratio, but, even under these unfavourable conditions, any significant differences in colour intensity are still indicative of differences in the amylose : amylopectin ra

ISSN:0368-4075    

DOI:10.1002/jctb.5000660502

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractThe butoxyl contents of cured urea‐formaldehyde‐butanol resin films have been determined by a modified Zeisel method, using a technique for film preparation whereby the film is obtained on a glass substrate under controlled conditions. The results show that such films have a high butoxyl content even after long periods of stoving, thus supporting the theory that under the conditions used in the preparation of the resin, the butanol reacts .with the methylol urea polymers to form relatively heat stable eth

ISSN:0368-4075    

DOI:10.1002/jctb.5000660503

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractThis introductory paper describes the method and criteria that have been developed for a critical evaluation of die fungistatic action of chemically related compounds together with some related aspects arising from the application of these methods. Inhibition is determined as reduction in growth rate and particular attention has been giver, to dosage/response curves as providing a sound basis for comparisons between substances. Three moulds have been used :Aspergillus niger, Byssochlamys fulvaandPenicillium roqueforti.In the absence of inhibitor, growth/time curves were linear for all three organisms once the colony had attained a diameter of 10 mm.A. migerandP. roqucfortibehaved similarly in the presence of inhibitor butB. fulvashowed an accelerating growth that persisted and often resulted in the final diameter exceeding that of the control. In the first two organisms growth rate (mm. per 24 hours) in the linear phase has been used; forB. fulvathe rate was determined as soon as possible after the colony had reached 10 mm. and before it exceeded 20 mm.The dosage/response relationship forA. nigerhas the form:y= axb, wherey= inhibition,x= concentration of inhibitor;aandbare constants, the latter less than I. From this relationship inhibitory substances can be described in terms ofb(slope of log. dose/log. response curve) and log I30(—log. concentration giving 50% inhibition).B. fulvacan be interpreted similarly although complicated by acceleration in the growth/time curve. It is better to use log I67in place of log I50. Experimental values forP. roquefortican be interpreted as the resultant of an inhibitory action (logarithmic as before) and a stimulation rising to an early limiting value. In this case determination ofbis not practicable and inhibition is best expressed as log I50obtained graphically from experimental points. Log I25permits comparison at another part of the curve. Constantsband log I50determined forA. nigercan vary significantly between experiments although the cause of this variation is not apparent. Log I50is related to some factor that affects the control rate. The methyl ester causes striking morphological changes in the hyphal tips although concentrations of higher esters causing comparable inhibition fail to bring about such change

ISSN:0368-4075    

DOI:10.1002/jctb.5000660504

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractIn the preparation of methyl methacrylate by the acetone cyanhydrin‐methacrylamide route, a dimeric ester is formed as a by‐product, and can be isolated in amounts corresponding to about 1 % theoretical. The acid obtained by saponification of the dimeric ester has been shown to be α δ;‐dimethyl‐α β‐hydromuconic acid. Investigations made at points in the methyl methacrylate synthesis indicate that the dimeric acid is formed (as amide) by dimerisation of methacrylamide under the influence of the sulphuric

ISSN:0368-4075    

DOI:10.1002/jctb.5000660505

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractThe dry grinding of pectins from various sources in a ball mill caused depolymerisation of the pectin molecules as evidenced by the fall in the value of viscosity of aqueous solutions of the pectin and of acetone solutions of the nitro‐ester. The depolymerisation was accompanied by loss of gelling power. The calcium pectate and saponification values were not changed significantly by grindin

ISSN:0368-4075    

DOI:10.1002/jctb.5000660506

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractFollowing an historical introduction, a short survey is given of the chemical properties of trimethylamine oxide. The results of determinations of the content of trimethylamine oxide in Norwegian marine products, as well as results of investigations of the fate of trimethylamine oxide during bacterial decomposition of raw materials for canning, are reported. Certain chemical reactions taking place in canned products during storage, are then treated. In this connection the importance of trimediylamine oxide in the corrosion of cans and for the “maturing” of canned products is discus

ISSN:0368-4075    

DOI:10.1002/jctb.5000660507

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractPrevious papers in this series1,4have recorded the loss of ascorbic acid incurred in the drying of vegetables in the laboratory. In the present note data arc presented on the loss of ascorbic acid from cabbage and potato when the vegetables were dried in large‐scale factory plants. The experiments were carried out at two factories, which were using a standard Ministry of Food plan

ISSN:0368-4075    

DOI:10.1002/jctb.5000660508

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractThe preparation of 2 :4 : 6‐trinitrobenzoic acid by the oxidation of 2:4:6‐trinitrotoluene (TNT) in nitric acid solution with sodium chlorate, by the method of Lüttgen,1has been rightly condemned by Clarke and Hartman2on the grounds of control difficulty. However, it has been found that ‐with suitable modification this method produces trinitrobenzoic acid with the minimum of trouble and in 85—90% yield (cf. 60—70% by chromic acid

ISSN:0368-4075    

DOI:10.1002/jctb.5000660510

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY