摘要:

Thirteen organic compounds capable of forming chelate complexes were used to fix copper in cotton duck. Their rotproofing effectiveness was then determined by the loss in tensile strength during soil burial. The compounds tested were, in order of decreasing effectiveness, cupferron, 8-hydroxyquinoline, 1-nitroso-2-naphthol, dimethylglyoxime, salicylaldoxime, glucose oxime, diphenyl-thiocarbazone, rhodanine, benzoin oxime,s-diphenylcarbazide, acetoin oxime, and fructose oxime. Copper complexes formed with cupferron and 8-hydroxyquinoline possessed rot resistant properties far superior to those of copper naphthenate or any of the other compounds tested.

ISSN:1923-4287    

DOI:10.1139/cjr48f-032

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

A granular form of silver permanganate on a zinc oxide carrier has been found to oxidize carbon monoxide in air at ordinary temperatures and at high space velocities. There is no noticeable change in activity over the range of 30 to 100% relative humidity of the air, although a small amount of water vapor is essential to initiate the combustion of carbon monoxide. The above properties have been utilized in the rapid determination of low concentrations by measuring the heat of oxidation in a thermocouple cell. The relation between the potential of the thermocouple junctions and the concentration of carbon monoxide is linear over the range of 0 to 600 p.p.m. at a definite space velocity. With increasing flow rate at a constant concentration the potential rises rapidly to a maximum, but in the range of optimum flow the flow rate may be varied considerably without producing a major change in e.m.f. The thermal efficiency is about 81% at the optimum flow rate. Hydrogen, unless it is present in amounts considerably in excess of the carbon monoxide concentration, does not introduce an appreciable error in the determination. The method is applicable to the field determination of considerably less than 0.005% carbon monoxide in air and the degree of precision is about equal to that of most laboratory methods. Twenty to twenty-five cubic centimeters of the material will give a useful life of over eight hours in continuous tests on concentrations below 0.1% carbon monoxide.

ISSN:1923-4287    

DOI:10.1139/cjr48f-033

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

In connection with the preparation of a standard specification, it became necessary to investigate the luminous intensity and color of a large number of railroad fusees. The rapid and wide fluctuations in intensity made it necessary to use special methods of colorimetry. The intensity was recorded by a highspeed electronic potentiometer and a barrier-layer photocell with correcting filter. To the pen carriage of the potentiometer was attached a special diaphragm which, with a lens and slit, acted as a 'light valve' to keep the flux into the colorimeter at a constant level over a range of about four to one. The very rapid flickering was, of course, not entirely eliminated. Visual colorimetry was used, the comparison field being produced in the lower half of a divided integrating sphere, the upper half of which received light from the fusee under test. The field, 2° in diameter, could be observed with both eyes. The accuracy of the colorimetry was made adequate by a careful choice of filters, advantage being taken of a fortunate circumstance regarding the color of the fusees. The results of testing more than 200 fusees are summarized.

ISSN:1923-4287    

DOI:10.1139/cjr48f-034

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

A graphical means of design and gain calculation for cathode coupled amplifiers is described. The method, based on data supplied by the plate characteristic curves of the tube, can be used to advantage in predicting the performance of the amplifier and in determining the zero signal operating conditions.

ISSN:1923-4287    

DOI:10.1139/cjr48f-035

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

not available

ISSN:1923-4287    

DOI:10.1139/cjr48f-036

出版商:NRC Research Press    

年代:1948

数据来源: NRC