摘要:

Arguments are advanced to support a proposal that the speed of photographic emulsions intended for aerial photography be determined by the use of a resolving power criterion. A statistical summary of experimental results is given to show that on such a basis speed determinations can be made with sufficient reliability by different observers. The relation between speed and gamma is given for Aero Super XX.

ISSN:1923-4287    

DOI:10.1139/cjr46a-001

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

Surface tension measurements have been made on normal heptylic, pelargonic, capric, and lauric acids above their melting points and on aqueous solutions of heptylic, pelargonic, capric, and undecylic acids, at various concentrations. A modified capillary rise method was employed. The results indicate that the surface does not reach the stable state at once but requires considerable time, being slower for more dilute solutions and longer chain molecules. Evidence is given for the existence of a monolayer of closely packed molecules, with long axes perpendicular to the surface, each molecule occupying an area of approximately 25 Å for heptylic acid.

ISSN:1923-4287    

DOI:10.1139/cjr46a-002

出版商:NRC Research Press    

年代:1946

数据来源: NRC