摘要:

A hand refractometer may be useful for routine inspection of the solids content of honey, and of strawberry jam containing added pectin. For 76 pairs of determinations on honey,with a standard error of prediction of ± 0.4%; for 116 pairs of determinations on the jam,with a standard error of prediction of ± 0.3%, whereyis the per cent solids by the A.O.A.C. vacuum-oven method andxis the reading on the hand refractometer. A standard error of ± 0.5% was observed for determinations by the vacuum-oven method, and of ± 0.4% for determinations with the hand refractometer.

ISSN:1923-4287    

DOI:10.1139/cjr49f-010

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

The fluidized solids technique has been applied successfully to the flash distillation of oil from Alberta bituminous sand on a laboratory scale. At 500 °C. a 76% oil recovery was obtained. The remaining 24% produced approximately equal weights of coke and gaseous compounds. At temperatures below 460 °C. trouble was experienced in maintaining a fluidized bed because of the slow rate of distillation. As temperatures were increased above 500 °C. the yield of oil decreased, with a corresponding increase in gas formation.

ISSN:1923-4287    

DOI:10.1139/cjr49f-011

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

Unbleached cotton tentage duck treated with the copper and copper–iron complexes of nitrosophenylhydroxylamine showed considerable resistance to rotting in soil burial tests but gave evidence of enhanced actinic degradation and loss of treating compound as a result of outdoor weathering for three months during the summer. With samples containing a higher concentration of the complexes this degradation was more severe.

ISSN:1923-4287    

DOI:10.1139/cjr49f-012

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

The German general purpose tire rubber, Buna S-3, differed from the chemical rubber produced in Canada. The study of the polymerization recipe used for this polymer centered around the role of the regulator in the system. The German technique resulted in a system in which the dilute solution viscosity of the polymer remained relatively constant during the reaction. It was found that this system could be duplicated in the laboratory using the equivalents of the German materials. Methods of analysis for diproxid in solution and in latex were investigated. It was observed that the diproxid disappeared very rapidly from the system and the regulating index was found to be similar to that of tertiary amyl mercaptan and to lie between that ofn-dodecyl andn-tetradecyl mercaptan when all were used in the Buna S-3 system. The polymers produced compared favorably with the German polymer as to molecular weight homogeneity, response to heat softening, and other data. Substitution of tertiary amyl mercaptan in the Buna S-3 system resulted in a polymer very similar to that produced using diproxid, and the reaction rate was increased nearly fivefold. The polymer prepared with diproxid and other regulators in this system seemed to be more homogeneous than those prepared by the Mutual formula.

ISSN:1923-4287    

DOI:10.1139/cjr49f-013

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

Buna S-3 chemical rubber was prepared in 5 and 110 gal. glass lined autoclaves. The polymerization conditions were not identical with those reported by the Germans or by a concurrent laboratory program. The polymers failed to heat soften in a manner comparable to the German material but, nevertheless, when the polymer was degraded on a mill and compounded in a standard tire tread recipe the resulting vulcanizate had properties superior to GR–S and approximating those of low temperature chemical rubber, although the Buna S-3 lacked the ease of processing of the low temperature copolymer.

ISSN:1923-4287    

DOI:10.1139/cjr49f-014

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

By special methods of grinding it has been found possible to make reproducible ground-glass surfaces. A series of six surfaces of increasing roughness was produced in crown glass, and a similar series in flint. These were illuminated at normal incidence by 2850° K. light in a photoelectric goniophotometer and intensity was measured at various angles. The apparent color temperature of the light diffused at each angle was also measured photoelectrically, with visual checks at some angles. Photomicrographs were taken of some of the surfaces, and finally the recording spectrophotometer was used to measure the diffuse reflectance, diffuse transmittance, and transmittance over a half-angle of about 8°, of several glasses. Some sandblasted samples were also studied. The transmitted light is most reddish at 0°, while at angles of more than 60° most of the glasses raise the apparent color temperature of the light. With the most finely ground glasses the color temperature at 0° reaches 2300° K. Some theoretical studies lead to the belief that most of the color changes are due to scattering, while diffraction plays a minor part.

ISSN:1923-4287    

DOI:10.1139/cjr49f-015

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

The general manner in which guy wires behave is well known, but in this paper the problem is treated by means of new catenary formulae which are especially convenient for the purpose. The behavior is discussed in detail, and there is given a simple practical means of designing a set of guy wires which will serve any preassigned purpose. The method is illustrated by numerical examples.

ISSN:1923-4287    

DOI:10.1139/cjr49f-016

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

not available

ISSN:1923-4287    

DOI:10.1139/cjr49f-017

出版商:NRC Research Press    

年代:1949

数据来源: NRC