摘要:

Analyses of whole meals and beverages indicated that the amount of fluoride normally present in the adult diet is quite low but the ingestion of tea or high fluoride waters greatly increases it. The fluoride content of cow's milk from low and high water-fluoride areas was determined. Analyses of some baby foods showed that the fluoride content of certain cereals containing bonemeal is high. The influence on the infant diet of these cereals and of water and milk is illustrated.

ISSN:1923-4287    

DOI:10.1139/cjr50f-020

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The effect of different amounts of starch and crude fat on humin formation during the hydrolysis of gluten prepared from a commercial flour depended on the acid/protein ratio, high ratios giving less humin nitrogen and less humin weight. The nitrogen content of humin was almost independent of the acid/protein ratio but increased with decreasing humin formation. Filtration time increased markedly with increasing purity of the samples. The color of the hydrolyzates varied slightly with impurities and acid/protein ratios.

ISSN:1923-4287    

DOI:10.1139/cjr50f-021

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The sorption of the dye Orange II by wool has been determined at the boiling point in the presence of various concentrations of sulphuric acid and of sodium sulphate within the range usually found in practice. Some experiments were also carried out with hydrochloric acid and sodium chloride. It is shown that the results for any one acid and salt concentration can be represented by a simple relation which has the same form for all results. Although this relation has the form of an adsorption isotherm, it remains purely empirical at present. The salt effect is readily explained on the basis of the Donnan equilibrium. The effect of acid strength is to fix the saturation value for the dye.

ISSN:1923-4287    

DOI:10.1139/cjr50f-022

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The use of radiant heating panels 2 ft. square for obtaining data on heat outputs for design purposes, instead of panels about 15 ft. square, would save much time and expense. A miniature panel heating system was constructed and gave the desired data. For ceiling panels the method has the advantage of eliminating convective heat output. This is discussed in detail.

ISSN:1923-4287    

DOI:10.1139/cjr50f-023

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

A modified brucine method for the determination of small amounts of nitrate in biological material is described. Error due to instability of the reagent has been overcome by dissolving the brucine in 91% ethanol. A 10% solution of the alkaloid was found to be most satisfactory and was stable for up to a year. Less color is developed with the ethanol solution than with other commonly used solvents and the effective working range of the method is thus increased approximately five times. Chloride does not interfere seriously but nitrite must be removed (by adding urea and boiling) prior to the determination. Organic matter in the sample may char slightly when the concentrated sulphuric acid is added but this error is compensated for by appropriate blanks. The method has been applied successfully to cured meat and to soils, and excellent recoveries of added nitrate have been obtained. The results agree with those obtained by the gasometric method but are higher than those obtained by the phenoldisulphonic acid procedure.

ISSN:1923-4287    

DOI:10.1139/cjr50f-024

出版商:NRC Research Press    

年代:1950

数据来源: NRC