摘要:

The experimental technique employed in the determination of magnesium by means of tropaeolin 00, according to the method of Lang4), is discussed, and several sources of errors are pointed out. The solubility of magnesium tropaeolinate in water was determined; the saturated solution was shown to contain 3.25 × 10−7g magnesium per cm3at 20°C and about 2 × 10−7g magnesium at 0°C.A convenient method for the determination of minute quantities of magnesium (10−5to 10−7grams) was worked out. According to this method magnesium is precipitated with a known quantity of tropaeolin 00, the precipitate is separated by centrifuging and the excess of dye is estimated by measuring the extinction of a portion of the supernatant liquid after the addition of sul

ISSN:0165-0513    

DOI:10.1002/recl.19420611202

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

摘要:

AbstractIn the oxidation of xanthine and of uric acid in alkaline solution at 37° (or 40°) by free oxygen the oxidation of an arsenite solution is induced. Equipartition of the oxygen is thereby observe

ISSN:0165-0513    

DOI:10.1002/recl.19420611203

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

摘要:

AbstractThe phase transition in 1,2‐dibromoethane was studied dilatometrically. The transition was not accompanied by thermal hysteresis, but there were comparatively large superheating and supercooling effects. The transition temperature was found to be in excellent agreement with Pitzer's determination from heat content value

ISSN:0165-0513    

DOI:10.1002/recl.19420611204

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

摘要:

AbstractEinstein's theory forms the sole basis for a theoretical consideration of the factors governing the viscosity of a suspension.The practical significance of this theory is however only very relative, since Einstein's theory is only valid for very dilute suspensions (to concentrations of a few percents by volume), while in practice suspensions of medium to fairly high concentration are usually dealt with.1It was found possible to obtain theoretically a φ—c relation for a suspension of spherical particles which is in good agreement with the experimental results recently obtained by Eilers with asphalt emulsions. The relation derived by us is found to be valid up to high concentrations.The fluidity relation is as follows:2The physical concept upon which the φ—c relation obtained is based may be summarized as follows:aDue to the fall in velocity in the liquid a suspended particle takes on a rotating motion. To this rotating motion corresponds an extra motion of the liquid. The latter may now be considered as the cause of an energy dissipation (Einstein) or as the cause of a flow of liquid at the walls enclosing the flowing suspension, in a direction opposite to that of the main flow, and thus observable at a relatively great distance from the suspended particle (Burgers). Occurrence of the term −2.5 c.bThe other particles will also cause a motion of the liquid at the spot where the particle first considered is situated. The intensity of the extra motion of the liquid caused by the particle in question will hereby be changed. Occurrence of the term +1.552c2.3From the fundamental fluidity relation the following simple formula may be derived for the voluminositySee footnote9).VR:c= the concentration of the suspension in g/cm3d= the density of the suspended substance in the dry state.4There are indications that the same fundamental φ—c relation can be used as a basis for polydisperse colloidal systems, even when these systems are built up of long‐cha

ISSN:0165-0513    

DOI:10.1002/recl.19420611205

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19420611207

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

摘要:

AbstractThe dipole moment of cyanogen iodide, using benzene as a solvent, has been determined as 3.71 ± 0.02 D

ISSN:0165-0513    

DOI:10.1002/recl.19420611208

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

摘要:

AbstractFor mixtures of methyl ethyl ketone and water and of sec. butanol and water, the following data were determined:specific gravity, 21°/21°boiling point,composition of the liquid at boiling temperature,composition of the vapour at boiling temperature.Commercially pure products were use

ISSN:0165-0513    

DOI:10.1002/recl.19420611209

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

摘要:

AbstractThe compounds 2,2′‐dimethyl and 2,2′‐diethyl‐3,3′‐diketo‐diindolinyl‐2,2′ were prepared. They may be considered to be derived from indigo by the addition of two methyl or two ethyl groups at the double bond between the two indol radicals. The compounds resemble ind

ISSN:0165-0513    

DOI:10.1002/recl.19420611210

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

摘要:

AbstractAzines of aromatic aldehydes undergo “crisscross” addition with two molecules of maleic acid anhydride, with the formation of bis‐pyrrolidine deriva

ISSN:0165-0513    

DOI:10.1002/recl.19420611211

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

摘要:

AbstractCompounds like Schiff's bases and azines, which contain the group C:N, are able to add a molecule of maleic acid anhydride at the nitrogen a

ISSN:0165-0513    

DOI:10.1002/recl.19420611212

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY