摘要:

An electrometric method for determination of nitric acid in RDX(B) liquors has been developed. The method is not largely affected by ammonium nitrate and acetic anhydride. A precision of ± 0.5% may be readily obtained. Acetic anhydride in RDX(B) liquors may be determined by direct titration with standard aniline–toluene solution at 0 °C., using calcium hypochlorite as an external indicator. In routine analysis, a precision of ± 2% may be obtained.

ISSN:0008-4042    

DOI:10.1139/v53-028

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

The thermal neutron capture cross sections of Na23and Mn55have been determined using the activation method. The values are 0.53 ± 0.03 and 12.7 ± 0.3 barns respectively with respect to σAul97 = 93 barns. These agree well with recent pile oscillator results. The half-life for Mn56is found to be 2.576 ± 0.002 hr.

ISSN:0008-4042    

DOI:10.1139/v53-029

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Wheat plants were fed with C14O2at the stage of growth corresponding to rapid lignification. Thereafter, plants were harvested every few days until maturity. The specific and total activity of the plants, and the specific and total activity in some lignin degradation products were determined. Results indicated that (i) C14O2was still being respired from the plants at maturity, (ii) all the C14which gets into the lignin does so within 24 hr. from the administering of C14O2, (iii) the total activity originally acquired by the syringaldehyde portion of the lignin remains constant throughout the growth of the plant, that is, the lignin (as represented by syringaldehyde) is a final end product of the plant and is not a part of the respiratory system, (iv) the total activity originally acquired by the vanillin suffers an initial drop for about two weeks after activation and then becomes constant, (v) thep-hydroxybenzaldehyde activity drops continuously throughout the life of the plant.

ISSN:0008-4042    

DOI:10.1139/v53-030

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

An analytical method has been developed for the estimation of nitric acid in acetic acid – acetic anhydride media, with a precision of 0.3%. The procedure involves the addition of a solution of potassium acetate in acetic acid to the sample. The excess is back-titrated conductometrically with a standard solution of nitric acid in acetic acid.

ISSN:0008-4042    

DOI:10.1139/v53-031

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

The serum proteins albumin and γ-globulin were precipitated by two polyhaptenic azobenzenearsonic acid dyes, at pH values in the region of or below the isoelectric points of the proteins. The occurrence of an optimum zone of precipitation suggests either a colloidal precipitation or the formation of a framework of dye and protein. The molecular ratios of dye to protein in the precipitate suggest increasing aggregation of the dye with lowering pH. The aggregation appears to be an acid constant effect. An estimate of the number of protein combining groups for one of the dyes is 22 for albumin, and 44 for γ-globulin. At pH values between 5.0 and 5.4, at which albumin is not precipitated, the precipitation of γ-globulin by the dyes is dramatically reduced by the presence of albumin. Apparently albumin forms soluble complexes with either the dye or γ-globulin or with both these substances.

ISSN:0008-4042    

DOI:10.1139/v53-032

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Kiliani's classic reduction of α-glucoheptonic (D-gluco-D-guloheptonic) lactone led to small, variable yields ofn-heptanoic acid and varying amounts of the lactone of a hydroxy-n-heptanoic acid. A repetition of this work showed that the combined yields of these two products reached a maximum near 70% of theory when the reduction with constant-boiling hydriodic acid (b.p. 127 °C) and phosphorus was limited to two hours. Under these conditions up to 9/10ths of the product consisted of the lactone. After purification through the hydrazide, m.p. 89 °C, the fragrant smelling lactone boiled at 61° to 62 °C at 10 mm. pressure, had a density of 0.9948, and a refractive index ofnD, 1.4405, both at 20 °C. The supposition that this lactone referred to 4-hydroxy-n-heptanoic acid was confirmed by preparing it from the known 4-keto-n-heptanoic acid, which in turn was synthesized by an improved method.The optimum time for reducing an uncrystallized mixture of α- and β-fructoheptonic acids under similar conditions was three to four hours, and the optimum yield of product was again near 70% of theory. This product consisted almost exclusively of the lactone of 2-methyl-4-hydroxyhexanoic acid. After purification through the crystalline hydrazide, m.p. 122 °C., the lactone was recovered as a fragrant oil boiling at 48° to 49 °C at 2 mm. pressure, with density 0.9806 and refractive indexnD1.4332 at 25 °C. The structure of this lactone was not in doubt.These lactones, prepared in good yield and with well defined hydrazides, were more readily characterized than the fully reduced heptanoic acids upon which Kiliani relied.

ISSN:0008-4042    

DOI:10.1139/v53-033

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

An electron micrographic study has been made of iron surfaces subjected to electropolishing. It has been found that although electropolishing produces a relatively smooth surface, the iron is covered with a film. The strengthening of this film by oxidation and its disruption by reduction with hydrogen have been followed. The film is assumed to be oxide and its thickness has been estimated to be approximately 100 Angstrom units. The effect of reduction of the film on surface area and thus on initial oxidation rates of the reduced specimen has been considered.

ISSN:0008-4042    

DOI:10.1139/v53-034

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Fission of uranium yields Xe135by two routes: direct production and production by the β-decay of I135. The amount produced directly (independent yield) has been measured by comparison with the amount produced from I135. The independent fission yield of Xe135is found to be 2.7 ± 1.0% of the cumulative yield of I135. Assuming this latter quantity to be 5.6% of all fissions, the independent yield of Xe135is ∼0.15%. The half-life of Xe135has been measured as 9.13 ±.05 hr.

ISSN:0008-4042    

DOI:10.1139/v53-035

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

The oxidation of aerated aqueous solutions of ferrousammonium sulphate has been studied using radium gamma rays and X rays of 24.5 Mev. peak energy from a betatron. The behavior at high photon energies has been shown to be closely similar to that at lower photon energies.

ISSN:0008-4042    

DOI:10.1139/v53-036

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

The products of the electrical discharge through hydrogen peroxide vapor were hydrogen peroxide, water, oxygen, and hydrogen, in amounts which depended upon the arrangement and temperature of the trap, reaction time, and surface to volume ratio of the reaction vessel. Water, hydrogen, and oxygen resulted from the gas phase reactions of the dissociated hydrogen peroxide, with hydrogen peroxide produced only in a trap cooled below −120 °C. Products trapped below −150 °C evolved oxygen on warming to room temperature. The decomposition products of the electrical discharge through hydrogen peroxide correspond closely with products obtainable both from a similar discharge through water vapor and from the interaction of hydrogen atoms with oxygen molecules in a cold trap. A mechanism which accounts for their correspondence is included. Water was the only product when molecular hydrogen peroxide was caused to react with hydrogen atoms, dissociated hydrogen peroxide vapor, or dissociated water vapor in the presence or absence of molecular hydrogen. A chain mechanism is postulated for these reactions.

ISSN:0008-4042    

DOI:10.1139/v53-037

出版商:NRC Research Press    

年代:1953

数据来源: NRC