摘要:

This paper deals with experiments performed to determine the electrostatic properties of celluloid camera films. The information derived was used in attempts to eliminate marks due to static electricity on film used in aerial photography.Camera films were rubbed with wool or brass and the resulting electrostatic effects studied. The required atmospheric conditions were reproduced by carrying out the experiments in a tank in which pressure, temperature and humidity could be controlled independently. It was found that the charging effect was more pronounced in a moist than a dry atmosphere.Methods of eliminating the trouble caused by static electricity in aerial photography are discussed.

ISSN:1923-4287    

DOI:10.1139/cjr33-080

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

An account is given of the outstanding work done and theories developed in connection with the critical phenomena during the last century. It was because of certain observations made in this laboratory a short time ago upon reaction rates at the critical temperature that the present investigation was begun with a view to providing more definite data concerning the density of both the liquid and gas in the region of the critical point.Experimental conditions have been kept under the most rigid supervision and previous errors eliminated or evaluated. A distinctly new technique has been developed, utilizing quartz spirals, for determining the density of both the liquid and gaseous phase almost simultaneously, up to, and past, the point where the meniscus vanishes. The results have been compiled from a great many observations taken over a period of two years upon eight separate units. In general, good agreement has been obtained in all but one case, and a probable solution has been advanced for the exception. Primarily, the paper is an experimental one designed to fill an important gap in previously recorded data.Extensive theoretical deductions have been purposely omitted because of the radical nature of the findings; and it would be necessary to proceed further with the work before anything really definite might be concluded. Briefly, it might be stated that the results cast considerable doubt upon Van der Waals' classical theory of the continuity of state.

ISSN:1923-4287    

DOI:10.1139/cjr33-081

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

An apparatus and a technique for studying the adsorption of gases, vapors and liquids on solid surfaces are described. The arrangement permits investigations in the region of the critical temperature and the critical pressure. Results with the system propylene and alumina are given. Adsorption from the gas and vapor phases indicates the formation of a surface complex which is unstable at low pressure and high temperature. The density of the adsorbed phase is greater than that of the bulk phase. There is no discontinuity in adsorption processes with a change from vapor state to gaseous state. No evidence was obtained of an increase in critical temperature on the surface of the solid. Adsorption does not occur from the liquid state, and there is a marked discontinuity in the adsorption curve with a change from liquid state to gaseous state. This is probably due to a change in the forces of attraction between liquid molecules and the solid as compared with the attraction between gaseous or vapor molecules and the solid surface. If this is the case it is further evidence for the discontinuity in the region of the critical temperature, which has been previously observed in other experiments in this laboratory.

ISSN:1923-4287    

DOI:10.1139/cjr33-082

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

Samples of wheat were exposed in the stook over winter and threshed in the spring in two seasons. These spring-threshed samples were compared with check samples from the same lots that had been threshed in the fall. The exposed samples lost grade in 50% of the cases, and decreased in weight per bushel in practically all cases. The flour yield was generally increased slightly as a result of the winter exposure. In respect to baking quality 22% showed improvement and 40% showed damage. The changes in grade and bushel weight do not correspond very closely with changes in baking behavior.

ISSN:1923-4287    

DOI:10.1139/cjr33-083

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

The recent discovery by Navashin (3), that the chromosomal mutation rate inCrepiswas influenced by aging of the seed, has been corroborated by observations on the mutation rate of corn plants grown from seed of various ages.A very high chromosomal mutation rate in barley was induced by heat treatments of seed under various conditions of humidity. The most common type of aberration resulting from these treatments appeared to be fracture of the chromosomes either at the attachment constriction, the secondary constriction or the point of attachment of the trabants. The reattachment of fragments to other chromosomes was observed in two instances.Considerable importance is attached to the discovery that a large proportion of the mutant cells are eliminated during the growth of the plant. The principle thatonly the fittest surviveseems equally true of cells as of individuals and groups of plants or animals.

ISSN:1923-4287    

DOI:10.1139/cjr33-084

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

The marine algae of the Atlantic coast of the maritime provinces of Canada were collected at representative places all along the coast. The most intensive collecting was done at St. Andrews, New Brunswick, and at Halifax, Nova Scotia. An entire summer was spent collecting around Prince Edward Island. The report covers the work of more than seven years. The collecting was done chiefly during the summer, but regular collecting was also carried out for two winters. The area is divided into three distinct geographical and ecological regions, namely, the Bay of Fundy, the Atlantic, and the Prince Edward Island regions. In the list of species, their regional distribution and prevalence are given in tabular form. The list includes 120 species, divided into 30 Chlorophyceae, 41 Phaeophyceae, and 49 Rhodophyceae. In addition to critical notes regarding certain forms, the striking differences in the marine flora from region to region are indicated diagramatically by distribution maps for a number of species.

ISSN:1923-4287    

DOI:10.1139/cjr33-085

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

The coastal area of the maritime provinces of Canada is divided into three regions, the Bay of Fundy, the Prince Edward Island, and the Atlantic. Each of these is distinctly different in regard to both marine flora and marine flora environment. The main features of the marine flora of each region are as follows: Bay of Fundy, generally dense and luxuriant; Prince Edward Island, a barren littoral zone and a rich sublittoral flora; Atlantic, intermediate in density and luxuriance with the predominance of large linear forms in the surf. With the exception ofFucus vesiculosusandAscophyllum nodosumwhich are dominant in the littoral zones of both the Bay of Fundy and Atlantic regions, there are species dominant for each region and peculiar to it. The physical factors varying throughout the area, and associated with the floral differences are: water temperature, tides, wave action, clarity of the water as regards mud, structure and composition of the rocks along the shore, materials forming the ocean floor near the shore, slope of the intertidal zone, slope of the ocean floor near the shore, salinity, and ice action. Each of these physical factors is associated with certain characteristic features in the marine flora.

ISSN:1923-4287    

DOI:10.1139/cjr33-086

出版商:NRC Research Press    

年代:1933

数据来源: NRC

摘要:

Gelasinosporais a genus closely related toSordaria, characterized by the foveolate sculpturing of the spore wall. At present it contains two species, as follows:—I.Gelasinospora tetrasperma, a coprophilous fungus which has been cultivated from spores collected in Manitoba and in Ontario.The species is described, together with illustrations of the chief characters, such as the four-spored condition of the ascus and the thickened ring bordering its apical perforation.Each normal-sized spore gives rise to a homothallic mycelium. The normal spore contains four nuclei. Asci very occasionally produce dwarf spores. Each dwarf spore gives rise to a mycelium which produces archicarps, but no perithecia. The mycelia from dwarf spores fall into two groups, (+) and (−), in regard to their sexual behavior. When (+) and (−) mycelia are paired, perithecia are produced. Sometimes asci contain giant spores. The giant spores usually produce homothallic mycelia and the spores usually contain six nuclei.II.Gelasinospora cerealis, isolated from the crown of wheat and oats in Manitoba.The species is described, together with illustrations of the chief characters, such as the eight-spored condition of the ascus and the two radial thickenings at its apical perforation.Each spore gives rise to a homothallic mycelium. The spores are binucleate.

ISSN:1923-4287    

DOI:10.1139/cjr33-087

出版商:NRC Research Press    

年代:1933

数据来源: NRC