摘要:

Vegetable-tanned leather had a fungicidal effect on one strain ofTrichophyton gypseumand two strains ofT.interdigitalebut not on several strains of common mould contaminants. Chrome-tanned leather, vegetable-tanned leather from an old shoe, and vegetable-tanned leather leached overnight in running water did not possess fungistatic or fungicidal properties.Of a number of disinfectants tested under conditions similar to those occurring during the fat-liquoring operation, phenylmercuric acetate was the most effective, destroying the above organisms in a concentration of 1:100,000. Under the same conditions a 1:1000 dilution of commercial formalin was required.

ISSN:1923-4287    

DOI:10.1139/cjr44f-019

出版商:NRC Research Press    

年代:1944

数据来源: NRC

摘要:

Curves are presented showing the growth in liquid egg ofSalmonella bareilly,S.manhattan,S.typhi-murium,S.oranienburg,S.typhi,Escherichia coli,Aerobacter aerogenes,Staphylococcus aureus,Streptococcus fecalisandS.pyogenes, and ofSalmonella bareillyin reconstituted egg.Streptococcus pyogenesdoes not grow in egg and dies off rapidly at temperatures above 60° F. (15.6 °C.). The other organisms generally grow well in liquid egg at temperatures above 60° F. (15.6 °C.). Liquid and reconstituted egg should therefore be maintained well below this temperature to prevent the multiplication ofSalmonellaand other possible pathogens.

ISSN:1923-4287    

DOI:10.1139/cjr44f-020

出版商:NRC Research Press    

年代:1944

数据来源: NRC

摘要:

Some physical properties of a sample of bituminous sand from the Abasand Oils Ltd. quarry have been determined. The sample contained about 17% bitumen and 1% water. The porosity of the sample in its natural state of packing was 39 to 40%, while saturation of the pore space with bitumen was 80 to 85% and with water, 3.5 to 4.5%. The coefficient of thermal conductivity of the sample in its natural state of packing was 0.0035 in c.g.s. units and at 45 °C. The specific heat of the bitumen content of the sample was 0.35 and of the mineral content, 0.18 for the temperature range 0° to 100 °C. The bitumen had a calorific value of 17,860 B.t.u. per lb.

ISSN:1923-4287    

DOI:10.1139/cjr44f-021

出版商:NRC Research Press    

年代:1944

数据来源: NRC

摘要:

The effects of moisture content on the heating of flaxseed and sunflower seed were studied in an adiabatic thermostat. Under these conditions, storage periods of less than two months produced heating in flax at 11.4% moisture and in sunflower seed at 10.5% moisture. Thus it appears that the commercial limits of 10.5 and 9.5%, moisture respectively are not too low for these grains.Evidence is presented to show that an acceleration in the over-all respiration rate of flaxseed and sunflower seed precedes heating. This indicates that heating is caused by active growth of the microflora on the grain and, at moisture levels in the order of those required for safe storage, normal embryonic activity is insufficient to cause heating.It is suggested that when the relative humidity of the interstitial air in bulk grain exceeds a value of 74% the microflora will grow and heating may ensue. From this it follows that the moisture content of any grain, in equilibrium with air at a relative humidity of 74%, will closely approximate the upper limit permissible for admission to 'straight' grades.

ISSN:1923-4287    

DOI:10.1139/cjr44f-022

出版商:NRC Research Press    

年代:1944

数据来源: NRC

摘要:

Linseed oil that has been hydrogenated to a plastic consistency is subject to a type of deterioration termed "flavour reversion" when heated to temperatures used in baking or frying. Investigation of the course of hydrogenation of linseed oil by the spectral method of Mitchell, Kraybill, and Zscheile (11) has indicated that linolenic acid is converted to an isomeric linoleic acid; this acid differs from naturally occurring linoleic acid in that the double bonds are in such positions that diene conjugation is not produced by high-temperature saponification. In a typical hydrogenation, the concentration of the isomeric acid increased to a maximum, at about iodine number 120, of 18% of the total fatty acids, and at iodine number 80, at which point the plasticity was similar to that of a commercial shortening, the concentration of the isomer was 13%. Evidence is presented that the isomeric linoleic acid in partially hydrogenated linseed oil is responsible for the unpleasant flavour that develops when the oil is heated.

ISSN:1923-4287    

DOI:10.1139/cjr44f-023

出版商:NRC Research Press    

年代:1944

数据来源: NRC

摘要:

The common milkweed,Asclepias syriacaL. was selected from the most promising native genera as the only species with a resin–rubber content high enough to warrant extraction studies. Rubber is concentrated in the leaves. Drying milkweed under glass in air and full daylight at temperatures up to 60 °C. does not reduce the rubber content. Concentrates are produced by fermentative decomposition. There is a gradual increase in the leaf rubber content during the growing season, with a maximum of about 3.5% in late September in the Ottawa district.

ISSN:1923-4287    

DOI:10.1139/cjr44f-024

出版商:NRC Research Press    

年代:1944

数据来源: NRC

摘要:

Resin–rubber gum containing about 40% resin, 35% rubber, and 25% residue insoluble in either acetone or benzene, has been extracted from milkweed leaves by a mechanical method. The extraction method involves cooking leaves in dilute alkali, washing until the pH is reduced to about 9.5, and pebble milling to effect agglomeration. Sodium hydroxide solution (1.5%) boiling at atmospheric pressure has been used with cooking periods of fromto 3 hr. Gum yields of the order of 8% of the weight of dried leaves have been obtained.Resin–rubber gums also have been obtained by this method from the stalks and seed pod hulls of milkweed. Similar materials have been extracted from a number of other plants.

ISSN:1923-4287    

DOI:10.1139/cjr44f-025

出版商:NRC Research Press    

年代:1944

数据来源: NRC