摘要:

This paper is based upon data for the thixotropy of paints given in the previous paper of this series. The data will not be repeated here but reference will be made to it when necessary.

ISSN:0148-6055    

DOI:10.1122/1.2116448

出版商:The Society of Rheology    

年代:1932

数据来源: AIP

摘要:

The first two papers of this series have dealt entirely with thixotropy, while this paper deals with plasticity as it is affected by the presence of thixotropy. Several rather revolutionary conclusions will be arrived at for which the experimental proof cannot as yet be considered adequate. An attempt will be made to show the line of reasoning that leads to these conclusions.

ISSN:0148-6055    

DOI:10.1122/1.2116449

出版商:The Society of Rheology    

年代:1932

数据来源: AIP

摘要:

Theoretical Rheology deals with the definitions, physical concepts, and mathematical relations governing both the intrinsic flow‐characteristics or rheological properties of materials, and the resultant flow‐phenomena that may occur under stated conditions. The field of Theoretical Rheology need not be restricted to the study of problems for which a purely deductive solution can be found, but may be considered as including also the scientific planning and interpretation of experimental work.

ISSN:0148-6055    

DOI:10.1122/1.2116450

出版商:The Society of Rheology    

年代:1932

数据来源: AIP

摘要:

It is highly desirable in vacuum distillation for the purification of materials to be able to split the fractions of distillate without interrupting the distillation itself. Inasmuch as only the two fractions are required, the low boiling and the pure material fractions, the apparatus illustrated in the accompanying diagram serves the purpose exceedingly well: a distilling flask,F, with two side arms. Two additional arms could be provided rather easily, however, in order to increase the number of fractions which could be collected without interruption.

ISSN:0148-6055    

DOI:10.1122/1.2116451

出版商:The Society of Rheology    

年代:1932

数据来源: AIP

摘要:

Lying on the border line between plastic and elastic action in metals and in other solids, there is a group of phenomena which have received a good deal of attention in recent years. On rapidly loading and unloading a rod, a given strain first appears and then as rapidly disappears. This is clearly elastic action. On loading the same rod slightly beyond the yield point and maintaining the load, the elastic component of the strain first appears, very rapidly followed by large additional deformations which do not disappear on unloading. The latter, in a ductile material, clearly represent the result of plastic flow. More accurate observations show that in this second case, the recovery on removal of the load can be separated into two parts, the larger part of the recovery occurring virtually instantaneously on removal of the load, the balance being spread over a long period of time, hours or even days, the rate of recovery decreasing as the time increases.

ISSN:0148-6055    

DOI:10.1122/1.2116452

出版商:The Society of Rheology    

年代:1932

数据来源: AIP

摘要:

In his lecture at the last meeting ofThe Society of RheologyDr. Erk considered the Engler viscometer and pointed out that the relationship between kinematic vicosity ν and Engler degreesEis adequately represented by Vogel's empirical equationν = E100 {7.6(1−1/E3)}. In contrast, as Dr. Erk also indicated, the theoretical equations of Mises and of the author show appreciable departures from experimental values. With regard to the equation considered by the author as an approximate equation for high viscosities, I have since found that an error was made in its derivation, so that the failure of the equation is not to be ascribed to the theory of laminar entrance‐flow. Meanwhile it has been demonstrated that the theory of laminar entrance‐flow, as far as one can expect it, actually agrees with observations and with Vogel's equation, as I should like to show you briefly.

ISSN:0148-6055    

DOI:10.1122/1.2116453

出版商:The Society of Rheology    

年代:1932

数据来源: AIP

摘要:

In calibrating any apparatus adapted to measuring directly the coefficient of absolute viscosity of liquids, the constant must be obtained within certain limits of error. Direct calculation would leada priorito about 1 per cent for this error. The experiments made up to date show that it is more and that it may be 2 per cent. The authors attribute these additional errors to the great variation of viscosity with temperature of the standard liquids used, and to the uncertainty in maintaining uniformity of temperature in these liquids.The custom of using only such viscometric apparatus that is capable of giving directly a correct measure of this physical constant is spreading more and more among technologists of the oil industry. More and more often the objection is raised that these instruments are rather delicate in manipulation. The one thing really necessary for transpiration instruments is to have a set of capillary tubes, which assures laminar streaming, the so‐called Poiseuille régime, during every determination.Since it is impossible to construct capillaries of predetermined dimensions, it is necessary to calibrate each tube before releasing it for service.It is in a course of preliminary experiments toward the establishment of a center for the calibration of viscometrical tubes at the National School for Petroleum at Strasbourg, that we have been led to make the above remarks. We should like to have the opinions of others who have had occasion to do similar work.

ISSN:0148-6055    

DOI:10.1122/1.2116454

出版商:The Society of Rheology    

年代:1932

数据来源: AIP

摘要:

For many years scientists have tried to correlate the viscosity of pure liquids with their other physical and chemical properties. A relation between viscosity and chemical composition was observed first by Pribřam and Handl. Thorpe and Rodger attempted to assign a value to each atom in 1893. It was shown by Bingham and Harrison that fluidities rather than viscosities are additive, and they devised atomic temperature constants of fluidity for the single fluidity of 200 rhes. The effect of association on fluidity had not been noted heretofore, but Thorpe and Rodger assigned values to the iso‐grouping, the double bond linkage, the ring grouping, the hydroxyl oxygen, etc., which denoted the supposed effects of “constitution.” These constitutive effects were at least partly due to association. Bingham and Harrison gave a method for calculating the association and compared the values obtained with the values obtained in other ways. They found that the values to be assigned to a double bond, a ring grouping or an iso‐grouping are very small. Bingham and Darrall in a study of the isomeric octyl alcohols went so far as to assume that the constitution of chemical compounds does not affect the fluidity except in so far as it affects the association. It is a very simplifying assumption that the slight difference between the temperature required to give an unsaturated compound a certain fluidity and that required to give the corresponding saturated compound the same fluidity is due to association. The absence of two hydrogen atoms is made up for by the “condition of unsaturation.” Bingham and Fornwalt substantiated the conclusions of Bingham and Darrall and they were able to formulate the trend of association with changes in chemical composition and constitution for a number of types of compounds.

ISSN:0148-6055    

DOI:10.1122/1.2116455

出版商:The Society of Rheology    

年代:1932

数据来源: AIP

摘要:

The theories which have been proposed in order to explain rheological phenomena have increased to such an extent that it is difficult to avoid confusion. Some of these theories appear to be conflicting, although they may be equally correct, each one in its own field. For this reason a systematic survey of rheological theories should be very useful. It should make understanding the different theories more easy and it should assist in assessing to each of them its value in its proper field.

ISSN:0148-6055    

DOI:10.1122/1.2116456

出版商:The Society of Rheology    

年代:1932

数据来源: AIP

ISSN:0148-6055    

DOI:10.1122/1.2116457

出版商:The Society of Rheology    

年代:1932

数据来源: AIP