bluuebunny/crossref_metadata_2025 huggingface dataset:
The General Law of Flow of Matter
Authors: Reiner Markus
Published: January 2006

One may safely state that every material flows under certain conditions. It has been proved that this holds good for every solid, even for extremely brittle materials, which under ordinary conditions crumble to pieces as soon as the stress applied exceeds the cohesion. The condition under which such a material has to be placed to make it flow is a sufficiently high pressure acting on all sides. The brittleness then disappears and the material, instead of being friable, flows, like any plastic substance. This has been shown for cubes of marble by Karman.
The Plasticity of Solvated Colloids
Authors: Sheppard S. E. , Houck R. C.
Published: January 2006

Since attention was drawn by E. Hatschek and by E. C. Bingham to the anomalies of flow of suspensions and colloidal solutions, a great deal of work on this subject has been carried out, not only on suspensions of solid particles but also upon emulsions and solvated colloids.
A Modified Plastometer for Industrial Use
Authors: Gregory D. V. , Rassweiler G. M. , Lampert K. C.
Published: January 2006

At the present time in the paint, varnish, and lacquer industry there are a number of different methods for determining the viscosity, or as the paint man expresses it “the consistency” of a paint, varnish, or lacquer. It is difficult, and in some cases impossible, to obtain a correlation between these methods, which means that practically each type of product in this industry has its empirical method for measuring consistency. It would be highly desirable if one method and apparatus could be used throughout the industry so that intercomparisons could be made between all types of products. This paper is a description of an attempt to produce such an instrument which in addition to being universal would be correct in theory, would have the speed necessary for industrial use, and would require only a small amount of material.
The Plasticity of Solids
Authors: Davey Wheeler P.
Published: January 2006

The elastic limit is ordinarily defined as the limit beyond which Hooke's Law no longer holds. In terms of the usual engineering tests the elastic limit is indicated by a permanent deformation. More accurate measurements show, however, that the ratio of stress to strain is not a constant even before the point of permanent deformation. Calculations based on the electrostatic theory of crystal lattices show that instead of the stress, f, being simply proportional to the strain, Δr (i. e., f = f′Δr), it is to be represented by an infinite convergent series of the form f = f0 + f′ Δr + 12! f″(Δr)2 + 13! f‴(Δr)3± …. Normally f0 is zero, so that Hooke's Law is to be regarded as only an approximation based on the neglect of terms of higher order than f′Δr. It is therefore to be expected that Hooke's Law will fail for very refined measurements. The fact that it holds as well as it does up to the point of permanent deformation led Joffé to investigate the mechanism by which a permanent set is produced.
Flow Relationships in Nitrocellulose Dispersions
Authors: Wiggam David R.
Published: January 2006

Large amounts of work have been carried out in the study of flow conditions of liquids since the classical work of Poiseuille in 1842. Numerous satisfactory methods of measurement have been used for the truly viscous liquids. In the study of colloidal dispersions these same methods of measurement and similar methods of calculation have been applied. With viscous liquids the shearing stress is directly proportional to the rate of shear, but this is not generally true for colloidal dispersions of the nitrocellulose type (Figures 4 to 8). Hatschek some time ago called attention to this fact. To account for the difference in behavior of viscous liquids and hydrophylic substances in dispersing medium, M. von Smoluchowski has considered the latter as highly solvated masses which enclose dead areas of liquid. When the solution is subjected to shear these particles deform and the liquid in the dead areas acts as a drag on free flow. Similar considerations have been brought forward and extended by R. Hess and W. Ostwald.
A Multiple Bulb Consistometer
Authors: Herschel Winslow H.
Published: January 2006

In measuring the consistency of suspensions or plastic materials by the capillary tube method, it is necessary first to obtain a flow-pressure graph. This requires that successive observations should be made at different rates of flow. With the earlier forms of plastometer or consistometer only one point could be obtained on the required graph with a single run, and it proved unduly time consuming to obtain a sufficient number of points to adequately define the graph.
Internal Friction and the Structure of “Solvated” Colloids
Authors: Kraemer Elmer O. , Williamson Robert V.
Published: January 2006

Ever since Thomas Graham proposed the employment of a “liquid transpiration” tube (i. e., a capillary viscometer) as a “colloidoscope” (30b), internal friction or resistance to shear has been one of the most frequently used properties in the investigation of colloidal dispersions. Although it soon became evident that this property is in certain instances a very sensitive indicator of differences and changes in the inner structure of dispersions, the exact relationship between internal friction and structure has unfortunately remained obscure. In spite of this shortcoming, the “colloidoscope” or an equivalent instrument has proved its value as an empirical tool for both scientific investigations and industrial control. To serve these purposes, attention has been directed particularly to the refinement of experimental methods and to the empirical correlation of observable quantities.
The Rheology of Soil Pastes
Authors: Scott Blair G. W.
Published: January 2006

An apparatus is described for investigating the behavior of soil-water and clay-water pastes while flowing through narrow glass tubes. The nature of the curves relating rate of flow to shearing stress is discussed. It is found necessary to introduce a new constant into the flow equation, without which various serious errors occur in estimating the viscosity of very thin pastes, and the mobility of thicker ones.

While the author is at present unable to present any complete equation or series of equations to relate rate-of-flow to shearing stress independent of capillary dimensions for the whole range of stress investigated, yet certain constants of the material can be obtained having independent dimensions which are closely related to the properties of the soil as measured in the field and in the laboratory.
Plastic and Pseudo-Plastic Flow
Authors: de Waele A.
Published: January 2006

While an increasing number of workers are to be found in the field of the study of plastic flow, a fact which must appear rather disconcerting to the new student of the subject must be the great dissimilarity in viewpoint taken by the two schools of researchers in interpreting their data. While it is not proposed to undertake a complete analysis of the diverging conceptions obtaining, a few facts will be submitted which may serve to stimulate an enlightening discussion of the subject.
Plastic Study of Nitroglycerin-Nitrocotton Gels
Authors: Pritchett L. C.
Published: January 2006

Heretofore there has been no satisfactory method of measuring the consistency of mixtures of dynamite nitrocellulose and nitroglycerin. In general, the plastometer has not been applied to materials of very high consistency, although it is generally supposed that the flow-stress curve shows a high degree of curvature when the consistency rises. In a recent study of the properties of gelatin dynamites a precise method of consistency measurement became essential.
Consistency in the Application of Coatings to Paper
Authors: Cobb R. M. , Lowe D. V.
Published: January 2006

Among the color pulps used for coating paper, there are some that bear the reputation of giving difficulty on the coating machine, while others run perfectly under the same apparent conditions. Since Bingham first called attention to the plastic flow of solids in suspensions, a great deal of work has been done on the flow of dry pigments dispersed in oily vehicles. By applying similar methods of study to pigment pulps used in an aqueous medium, some light has been thrown on a bothersome coating problem which has hitherto defied solution.
Capillary Siphons
Authors: Bingham Eugene C. , Figlioli Daniel
Published: January 2006

In the ruling of paper it should be practical to run several hundred pens continuously for hours, all of the pens carrying the appropriate amount of ink, which amounts to as much as 0.4 ml per minute per pen. Not only must the flow be adequate regardless of the speed of the paper-feed within the limits of the machine but the flow of ink must practically stop with the stoppage of the machine. These requirements are met in an elegant manner by the use of capillary siphons, the most important part of which consists of woolen threads or “worsteds” which in themselves are very flimsy affairs, being made of very loosely twisted fibres but around these threads the capillary action forms a liquid skin which serves as the walls or the ink-delivery tubes, offering comparatively little resistance to flow.
A Study of the Fluidities and Densities of the Octyl Alcohols. The Association of Liquids
Authors: Bingham Eugene C. , Darrall Logan B.
Published: January 2006

Thomas Graham first directed attention to the desirability of a study of the flow of pure liquids in connection with their other physical as well as chemical properties. A serious attempt to realize this purpose was made by Pribram and Handl who noted the increase of viscosity with the molecular weight and attempted to establish a relationship. Rellstab observed the apparently important effect of chemical constitution in that metameric substances do not in general have the same times of transpiration. Brühl, perhaps too optimistically, inferred that among metamers those having the greatest viscosity have also the greatest density, the highest boiling point and the greatest refractive index. To this generalization, however, Gartenmeister found numerous exceptions; by securing unprecedented standards of precision in measurement, Thorpe and Rodger hoped to be able to assign exact viscosity values to each atom. Their excellent data seemed, however, to shatter this hope rather than to justify it.
The Viscosity of Dilute Lyophilic Dispersions
Authors: Kraemer Elmer O. , Sears George R.
Published: January 2006

There are a considerable number of materials that possess the property of forming highly viscous, colloidal solutions in surprisingly low concentrations. To this class belong certain proteins, agar, starch, rubber, cellulose, nitrocellulose, cellulose acetate, and synthetic polymerized substances, such as polystyrene, polyvinyl chloride, polyvinyl acetate, etc. It is not uncommon for one per cent solutions to have viscosities several hundred or thousand per cent greater than that of the solvent, whereas equal concentrations of chemically related substances, such as albumin, styrene, etc., may cause an increase of but a few per cent.
The Kinetic Energy Correction in Fluid Flow
Authors: Stone S. Bradford
Published: January 2006

For fluids which deviate from the law of Poiseuille, the kinetic energy term is usually ignored. In many cases this is justified since the experiments are performed under conditions where the correction is apparently negligible. The neglect of this factor in the flow of viscous liquids has caused many errors, and it is therefore desirable that some method of calculating the effect should be developed for other types of flow. The purpose of this paper is to calculate the kinetic energy correction by making use of general principles which apply to every possible case of flow, and also to obtain conclusions concerning the possible magnitudes of the correction.
In Search for a General Law of the Flow of Matter
Authors: Reiner Markus
Published: January 2006

1. In my paper presented before the Third Plasticity Symposium I tried to indicate the way in which one could hope to make progress toward the ultimate goal of Rheology, which is to establish the general law of flow of matter.
The Plasticity of Protoplasm
Authors: Seifriz William
Published: January 2006

A study of the plasticity of protoplasm offers all the difficulties of such a study on gelatin and those additional ones which are associated with a substance that is alive and can be had only in microscopic quantities. It is the task of the biologist to conquer, as best he can, these latter difficulties which have to do with method, but he must appeal to the chemist for help in the interpretation of results. Patient and sympathetic cooperation between chemist and biologist is necessary if physical biology is to advance.
A New Consistometer and Its Application to Greases and to Oils at Low Temperatures
Authors: Bulkley Ronald , Bitner F. G.
Published: January 2006

The consistometer to be described here is rugged, simple of construction, speedy in operation, and can be employed for either opaque or clear materials of a wide range of consistencies. It also possesses two features which are unusual in a consistometer, but which are of great importance in the testing of all such plastic materials as show a breakdown of structure with working, or which change in consistency with time.
The Slippage Correction in the Equation of Plastic Flow
Authors: Williamson R. V.
Published: January 2006

The term “slippage” was introduced by Bingham and Green to account for the flow of plastic or pseudoplastic materials when the shearing stress falls below the yield value as defined by them. The idea of slippage was given mathematical expression by Buckingham in his equation for plastic flow in capillary tubes as shown in Equation 1 S = μ (F − 4/3f + f43F3) + ceFr (1) where S = rate of shear, 4π Vtr3; F = shearing stress, Prg2l ; f = yield value; μ = mobility; c = slippage constant; e = thickness of liquid layer causing slippage. This equation has been recognized by a considerable following as representing the facts of flow in capillary tubes for all materials which do not give straight-line flow-pressure curves. But very few workers have made any attempt to test the equation over a wide range of conditions.
Classification of Plastics and Definition of Certain Properties
Authors: Karrer E.
Published: January 2006

Plastics are materials that under certain conditions have a convenient and useful range of plasticity. In general, something must be done to the material to bring it into the plastic state for purposes of molding; and, in general, something quite different must be done to make it again non-plastic. The first step in processing the material is termed plasticizing, the last is in some cases termed curing, but may, perhaps in general, be more appropriately termed deplasticizing.
Jean Leonard Marie Poiseuille
Authors: Brillouin Marcel
Published: January 2006

Poiseuille, born and died in Paris, appears to have passed his entire life as unattached (libre) professor of medical physics. He was the son of a carpenter. We know nothing of his primary studies nor of his preparation for the École Polytechnique.
The Fluidity of Liquids
Authors: Sheppard S. E. , Houck R. C.
Published: January 2006

The nature of the liquid state of matter is the subject of less definite conceptions than that of either the solid or the gaseous state. A clear concept obtains for the state of a gas on the basis of the molecular kinetic theory, in terms of a system of particles in random translatory movement. An equally clear general conception exists for the crystalline solid state, on the basis of the space lattice theory, in terms of atom-groups arranged in regular periodic ordering. Such atoms or atom-groups have no free translatory motion relative to the ensemble, but their thermal energy is due to vibrations about the centers of position which constitute the particular space group.
Chemical Constitution and Association
Authors: Bingham Eugene C. , Fornwalt Holmes J.
Published: January 2006

Constitution has been considered until recently to be of great importance in determining the fluidity of liquids. It is believed that association of liquid molecules also affects the fluidity so that it is surprising that in the earlier writings on fluidity, association as a cause of fluidity lowering was entirely overlooked. It appears that either chemical constitution or association might be effective but the problem of disentangling these effects is not easy. Gradually the so-called constitutive factors have disappeared as the data and the methods of comparison have improved until there appeared to be but two left which were small or avoidable and might also be explained on the basis of association. Bingham and Darrall in their study of 23 octyl alcohols made the assumption that chemical constitution determines association and that association has a pronounced effect on fluidity, but that constitution itself is without effect on the fluidity. By this simplifying assumption they were able to calculate the association of those alcohols and to point out for the first time that a simple relation exists between chemical constitution and association, both among the octyl alcohols and also the lower members of the alcohol series. For example, it was found that in a normal aliphatic alcohol the association decreases regularly as the paraffin residue is increased. This conclusion was perhaps to be expected, but so far as known it had not been demonstrated before and it raised many questions. Would this conclusion be borne out with other classes of compounds? Does the association actually decrease in a linear manner or asymptotically? If linearly, is it possible to obtain compounds with a zero or even a negative association? A vast field for research seemed to open out. New data seemed the most urgent need but there was also need for newer points of view. Since constitution brings about the association, the effects upon the fluidity are due to the constitution anyhow. Constitution refers to the method in which given atoms are linked up but one cannot well give a number to the constitution of a certain octyl alcohol. One can, however, measure the association of that alcohol. Hence it may be said that association is a measure of resultant constitutional influences. When we are in a position to evaluate the resultant of the forces between the electric charges, the relation of constitution to association may be calculable.
The Correction in Viscometry When Using Capillary Tubes Which Have Trumpet-Shaped Openings
Authors: Bingham Eugene C. , Thompson Richard R.
Published: January 2006

In the transpiration method, it has seemed to be the best practice to avoid trumpet-shaped tubes altogether by cutting the capillary off squarely and sealing it to the remainder of the apparatus without constriction or expansion of any kind. Aside from the mechanical difficulty of meeting this requirement, there have been those who have maintained that a capillary with a trumpet-shaped exit would be simpler to operate because it would make unnecessary the kinetic energy correction. The theory of the kinetic energy correction was worked out for a tube that was a true cylinder or, at any rate, departed from it but slightly, and therefore it seemed unjustifiable to use modified tubes without further investigation.
On the Flow of Viscous and Plastic Materials along an Initially Empty Long Narrow Glass Tube
Authors: Scott Blair G. W.
Published: January 2006

Bingham and Murray have described an apparatus for studying the properties of materials under flow in which the material is forced to flow along a long capillary of constant radius (initially empty) which is graduated in units of length. The time is taken for the head of the advancing column of material to pass each graduation.
A Method for Measuring the Relative Plasticity of Pastes and Doughs
Authors: Bailey C. H.
Published: January 2006

The relative mobility of industrial pastes and doughs is not infrequently too low to permit of its measurement with the classic type of flow plastometer. Yet the industrial operator must attempt to adjust and control the consistency of these materials within small limits of variation. Thus in the flour testing laboratory and in industrial bread baking the quantity of water required to bring the relative plasticity of dough to a definite level must be determined. The “feel” of such material in the hand of the experienced operative is the common criterion. Expensive errors of judgment, as revealed by inferior finished products, then occasion adjustments of the consistency by a trial and error procedure.
On the Determination of the Fluidity of Water as a Reference Standard
Authors: Bingham Eugene C.
Published: January 2006

At the recent meeting of The Society of Rheology, as reported in the January number, there was a formal expression by the body in favor of “immediate action on the problem of determining the viscosity of water for the purpose of establishing a reference standard,” and the appointment of a committee of five on Standards and Nomenclature was provided for. President Davey has appointed on this Committee, as published in the January number of THIS JOURNAL: G. S. Haslam, E. O. Kraemer, S. E. Sheppard, David R. Wiggam, and Eugene C. Bingham. It is hoped to have some foreign members to act with the committee, for, particularly in matters dealing with nomenclature, their assistance will be invaluable.
The Data of Poiseuille on the Flow of Water
Authors: Bingham Eugene C.
Published: January 2006

The original data of Poiseuille are not generally accessible and therefore they were reproduced in full in Fluidity and Plasticity but unfortunately with several errors, and it is highly desirable that these be corrected at this time when the fluidity of water is being discussed. The tables have therefore been compared by several people, and it is hoped that the following corrections will make them reliable.
Plasticity and Viscosity as Criteria of Molecular Aggregation
Authors: Sheppard S. E.
Published: January 2006

In a paper published in the JOURNAL OF RHEOLOGY Sheppard and Houck showed that certain solvent combinations of non-polar and polar liquids produced solutions of cellulose esters which gave purely viscous flow. It was argued that this indicated that the dispersion of these substances had been carried to molecular dispersion, the crystallites indicated by x-ray examinations being reduced to molecular entities of the long chain, primary valence type.
The Colloidal Structure of Egg White as Indicated by Plasticity Measurements
Authors: St. John J. L. , Green E. L.
Published: January 2006

The study of egg albumin has been approached from different angles and a large amount of work has been done upon it. Sorensen (1917) in a classical series of papers has studied the methods of preparation, chemical composition, chemical and physical-chemical properties of albumin isolated from egg white.
On the Rate of Shear in Capillary Tubes
Authors: Herschel Winslow H.
Published: January 2006

Since little is known concerning the laws of plastic flow, it is often convenient to use approximate methods of calculation based on the law of Poiseuille for simple viscous liquids. Neglecting the kinetic energy correction, the reciprocal of the viscosity is Fluidity = 4qπR3PR2L = YX (1)

where q = rate of flow in cm3 per second

P = pressure causing flow

R and L = radius and length of capillary
Some Fundamental Definitions of Rheology
Authors: Bingham Eugene C.
Published: January 2006

In 1678, roughly two hundred and fifty years ago, Robert Hooke announced his justly famous law of deformation, “Ut tensio sic vis” or the deformation of a body is proportional to the shearing stress producing it, or finally, in the more elegant language of mathematics, s = eFr.
A Contribution to the Theory of Thixotropy
Authors: Hauser E. A.
Published: January 2006

Although a careful review of literature has revealed that the phenomenon now termed “thixotropy” had already been observed some years ago by various research workers, the first systematic study of this phenomenon is of comparatively recent date as well as the denomination, which is taken from the Greek works, “ϑιξομαι” = “by touching” and “τζ′εωπω” = “to change,” and which gives a rather accurate conception as to what this phenomenon refers. For example, it has been found that certain colloids present in the form of a plastic gel can be spontaneously and adiabatically liquefied by simple mechanical influence, e. g., shaking, and that such liquefied gels, now being in the sol condition, will, if left quiet, return to the original plastic solid gel. This sol-gel-transformation can be repeated consecutively many times without changes in setting time, if all conditions are kept constant during the experiments.
The Thixotropy of Pseudo-Plastic Systems
Authors: de Waele A.
Published: January 2006

Since the publication of a paper by Freundlich (Kolloid-Z., 46, 289 (1929)), in which the term “thixotropy” was applied to the transient change in consistence resulting from the agitation of a gelating gelatin sol, several papers have appeared in the current literature dealing with this phenomenon. Since Freundlich, in the publication referred to, treats of thixotropic behavior in relation to consistence, the object of the present communication is to draw attention to the thixotropic phenomena of the specific factors characterizing dispersoid systems.
The International Comparison of Viscometers
Authors: Erk S.
Published: January 2006

It is not necessary, I think, to discuss before this group the trouble caused by giving the viscosity of oils generally in arbitrary systems of measure. The Engler, Redwood, and Saybolt viscometers are established and only the question remains for us today: What is our best method of procedure?
The Relation between the Plasticity of a Two Component Solid-Liquid System and the Degree of Wetting of the Solid by the Liquid
Authors: Bartell F. E. , Hershberger A.
Published: January 2006

In much of the work which has been done on plasticity of pastes, linseed oil and similar liquids have been used. Complex reactions may occur between the constituents of these liquids and the dispersed solid phase. In the present investigation reactions of this type were avoided by using pure organic liquids with solids which do not react chemically with them.
On the Deviations of the Pressure Drop in a Capillary from the Poiseuille Law
Authors: Erk S.
Published: January 2006

In the program of the Committee on Viscosity Standards recently published in THIS JOURNAL, the various points of view are presented which must be considered in carrying out exact measurements of viscosity. This summary is very welcome, all the more since confused statements concerning the meaning and the application of the two corrections, named after Hagenbach and Couette, are often encountered in the literature.
Explicit Formulas for Slip and Fluidity
Authors: Mooney Melvin
Published: January 2006

The hydrodynamical theory of a Newtonian fluid flowing through a capillary viscometer is quite simple and yields a formula for the fluidity in terms of the measured efflux. In the case of non-Newtonian fluids, on the other hand, the theory is not so simple. The usual practice among experimental rheologists is to assume some particular form of fluidity function, after which the corresponding efflux formula is obtained by an integration. If the efflux formula agrees with the experimental efflux data, the assumed fluidity function is thereby established as the correct one. However, it is sometimes difficult to find a fluidity function leading to an efflux formula which agrees satisfactorily with the data. In such cases the experimenter needs a more powerful method of analysis.
Viscosity Research into Protective Coatings
Authors: Van Heuckeroth A. W. , Stewart J. R.
Published: January 2006

Various types of viscosity cups are used by automobile manufacturers, and in other industries to determine the consistency of clear and pigmented products which they use. It was considered that it would be desirable to determine the relationship which exists between the types of cups which are most widely applied. For this purpose there was selected a number of products which gave a wide range of consistency.
The Static Rigidity of Plastic Clays
Authors: Terzaghi Charles
Published: January 2006

According to Atterberg's definition a clay can be considered to be in a plastic state, if its water content ranges between the lower and the upper limit of the plastic state. Although, by necessity, the methods for determining the limits are somewhat arbitrary, Atterberg's range of plasticity includes clay-water mixtures which have a fairly well-defined group of properties in common. Within this range an appreciable force is required to produce a continuous, plastic flow of the material and under the influence of forces beneath the “yield point” the material exhibits all of the characteristic elastic properties of imperfectly elastic solid bodies.
The Effects of Salts on the Extensibility of Protoplasm
Authors: Seifriz William , Plowe Janet
Published: January 2006

The life of a cell is intimately associated with its salt environment, whether this is the sea, the soil water, or the body fluids. The classical experiments of Ringer on the biological effects of salts initiated the extensive research which has been done on the relationship between cells and their electrolytic environment. Our excuse for adding to the voluminous literature on this subject is that we have chosen an as yet little studied property of protoplasm, namely, extensibility, as the criterion by which to judge the effects of the salts.
The Orientation of Dipole Molecules in a Viscous Medium
Authors: Williams John Warren , Oncley J. L.
Published: January 2006

In order to explain its variation with temperature and frequency the dielectric constant has been defined as a measure of the work done by an external electrical field in orienting molecules against the effect of their thermal agitation. Quantitative studies of the temperature variation of the dielectric constant of particular kinds of systems have been made and have given quite valuable information concerning the structure of molecules, but corresponding studies of the frequency variation of the dielectric constant have not as yet been so successful. It is the purpose of this article to discuss in some detail what seems to us to be the most important theoretical difficulty. By way of introduction it may be stated that in the case of a polar liquid there is a region in which the dielectric constant decreases with increasing frequency, the frequency region being dependent upon the size of the orienting molecule and the viscosity of the medium. The difficulty to be considered has to do with the manner in which in a solution the actual frictional resistance of the solvent molecules to the rotation of the polar solute molecules has been determined.
Preferred Orientation in Silver Foil Produced by Cold Rolling
Authors: Hollabaugh Cleveland B. , Davey Wheeler P.
Published: January 2006

According to the literature, the cold rolling of metals having a face centered cubic crystal structure causes one definite orientation. This preferred orientation is said to be independent of the rolling technique, and is given as the position in which the (0 1 1) plane of the crystal is parallel to the rolling plane and a (1 1 2) plane parallel to the direction of rolling.
Viscosity and Adsorption in Colloidal Solutions
Authors: Kraemer Elmer O. , Sears George R.
Published: January 2006

Colloidal dispersions may be divided into two classes: those in which the colloidal state of the dispersed substance is an extrinsic one, and those in which the dispersed substance is intrinsically colloidal. The extrinsic colloids are obtained by indirect means, in which one substance is finely pulverized or precipitated as fine particles from a homogeneous phase and distributed in a medium in which the subdivided material is in the ordinary sense insoluble. The dispersed condition is thermodynamically unstable, but may be pseudo-stable owing to the protective effect of an electric double-layer or to the presence of an intrinsic colloid that sticks to the particles of the extrinsic colloid. Intrinsic colloids, on the other hand, spontaneously disperse into suitable liquids in virtue of an affinity between colloid and medium which closely resembles that between solvent and solute in ordinary solutions. As a matter of fact there is evidence for believing that some intrinsic colloids, such as egg albumin, hemoglobin, and several other proteins, form molecular solutions just as truly as sugar, alcohol, and similar materials of small molecular weight. The colloidal behavior of these protein solutions is a consequence of the large size of the dispersed particle, even though each particle may be a single molecule, exceeding in size, for instance, the crystalline chunks in a colloidal gold solution. Rubber, agar, gums, cellulose and polysaccharides and their derivatives (e. g., cellulose esters and ethers), some dyes and soaps, and various naturally occurring or synthetic polymeric materials of high molecular weight are also intrinsic colloids. Their dispersions in spontaneously dispersing liquids resemble in essential respects the systems ordinarily called solutions, and they also may with propriety be called solutions. The absence of a well-defined solubility, which is sometimes offered as a feature distinguishing between solutions in the universally accepted sense and solutions of intrinsic colloids, is in fact, due to the failure of most intrinsic colloids to form a well-defined solid (or liquid) phase of unique composition, upon the existence of which the quantitative concept of solubility depends.
An Analytical Study of Leveling
Authors: Waring R. K.
Published: January 2006

It is assumed that the leveling of a pigment-vehicle mixture is a function of surface tension, yield value, and dimensions of brush marks.

A relationship is derived which takes the form h = d28 fγ

where h = depth of brush mark and is taken as a measure of leveling

d = width of brush mark

f = yield value

γ = surface tension.

Assuming reasonable values for γ and d, it is calculated that a pigment-vehicle mixture with a yield value less than 2.8 dynescm2 levels satisfactorily.
Slippage in a Non-Newtonian Liquid
Authors: Reiner Markus
Published: January 2006

1. In my second contribution I have proved mathematically that “if the fluidity, as usually calculated, is plotted against the stress at the wall, the curve is independent of the dimensions of the apparatus, irrespective of the law of flow of the liquid under test.”
Quasi-Laminar Capillary Flow
Authors: Peek R. L. , Erickson W. R.
Published: January 2006

The capillary flow of fluid and plastic materials that do not obey Poiseuille's Law has been subjected of recent years to very intensive study, and many hypotheses advanced which attempt to characterize the resistance to deformation of such materials. There is, however, a possible type of resistance which does not appear to have been previously considered, and which it is the purpose of this paper to discuss: a resistance which is a function of the strain, or amount of deformation already experienced. While it is probable that such an effect, when it occurs, is small, the question is of importance in connection with structural studies (e. g., of colloids), which are the occasion of many investigations of plastic or pseudoplastic flow.
The Flow of Colloids which Show Anomalous Viscosity
Authors: Kroepelin H.
Published: January 2006

In order to obtain information about the conditions of flow in solutions which show anomalous viscosity, the distribution of velocity in a straight tube of circular cross section for one of these solutions was directly determined by the methods that are usual in hydrodynamics. From a reservoir, A (Figure 1), the liquid flowed through a capillary tube (Figure 2). At the end of this tube in a box, B, was a Pitot-tube (6), by means of which the velocity head of the flowing liquid was measured. The driving pressure was measured at the points (1) and (2) with a U-shaped manometer, The Pitot-tube also was connected with one limb of a second manometer, the other limb communicating with a bore (3). As the mouth of the Pitot-tube was in exactly the same plane as that of the capillary tube and the bore (3), the velocity head was read directly on the manometer, since the hydrostatic pressure is constant in every plane perpendicular to the axis of the tube.
Notes on the Ring and Ball Method
Authors: Eaton Fred C.
Published: January 2006

This is a method used in measuring the softening point of a bituminous material. In fact, it has been adopted as standard by the American Society for Testing Materials. Recently Walker has discussed this test and suggested a more convenient form of apparatus.
The Flow of Dry Sand through Capillary Tubes
Authors: Bingham Eugene C. , Wikoff Robert W.
Published: January 2006

It has been proved that in the flow of liquids the resistance to flow depends, first, upon the size of the individual particles of which the liquid is composed and, second, upon the spacing of the particles, this latter being dependent upon the conditions of temperature and pressure. As the size of the particles is increased and the Brownian motion of the particles becomes less and less, the above statement cannot be accepted as applicable without supporting evidence. However, if the laws of flow of materials like powdered coal, cement, etc., were known, there might be developed an improved method for obtaining the average particle size. The sizes of the particles and their method of spacing will presumably determine questions concerning rates of settling, caking together, and the seepage of both gases and liquids in or out of the materials. In a preliminary investigation, it seemed best to begin with dry sand and capillaries of known lengths and radii, using various temperatures.
Notes on the Fluidity of Water in the Vicinity of 20°C
Authors: Bingham Eugene C.
Published: January 2006

Measurements of viscosity are practically all relative, since viscometers are calibrated with a liquid whose viscosity is assumed to be known, but many different values of the viscosity of water are in use dependent upon the authority consulted, or the conditions of temperature and upon the corrections which are made in the reduction of the data, and quite as often as not the final results are expressed as specific viscosities of one kind or another. Bulletin No. 278 of the U. S. Bureau of Standards contained certain proposals. (1) It was proposed that all viscosities be expressed in absolute units even though the measurements be relative. (2) Since the viscosity of water at 20°C is close to 0.0100 c. g. s. units, it was proposed to adopt the viscosity (or fluidity) of water at this particular temperature for the fundamental rheological standard. (3) By making the one-one hundredth part of the c. g. s. unit the practical unit of viscosity, and calling it the centipoise (cp) an advantage would be gained in that viscosities would all be specific. This would be perhaps most appreciated in studying the viscosity of electrolytic solutions, which are compared with the viscosity of pure water. (4) Different authorities were compared, the later corrections added, and an attempt made to secure the best value to be used as standard. Since the viscosity may be calculated by formula from values in the vicinity of 20°, these values were also not neglected in arriving at the most probable value, which was given as 1.005 cp.
The Fluidities of Non-Aqueous Mixtures
Authors: Bingham Eugene C. , Rogers Horace E.
Published: January 2006

The paper of Bingham and Brown makes it desirable to study the data on the fluidities of non-aqueous mixtures which have recently become available in connection with the International Critical Tables, to determine first whether there is a correlation between the fluidity and volume (test 3). It should, moreover, be possible to determine the composition of the compound formed in favorable cases where chemical combination takes place. Finally, although the minimum in fluidity should change with the temperature, the maximum deviation from the linear should not change with the temperature (test 4).
Fundamental Equations and Definitions Concerning the Mechanics of Isotropic Continual
Authors: Hohenemser K. , Prager W.
Published: January 2006

The mechanics of continua describe the behavior of deformable materials, that is, they predict the connection between forces and isothermic deformations in any kind of continuum. Of course the theory is confined to certain ideal materials which are so chosen as to show approximately the behavior of the natural materials. The best known among the ideal materials are the isotropic elastic solid and the viscous fluid, both of which are characterized by three constants: the modulus of compression, the density, and the modulus of rigidity, or the modulus of viscosity. Metals behave approximately in the same way as elastic solids, if only one takes sufficiently small deformations and sufficiently short times of observation. Fluids behave in the same way as the ideal viscous fluid, if the velocities of movement are sufficiently small. The problems concerning rheology, and the testing of materials which have, of late, made such great progress, urgently require, however, a more general theory which takes into account the imperfect elasticity of real solids and the imperfect viscosity of real fluids. In the following we shall discuss a few ideal materials of more general properties.
Dimensional Analysis of Plastic Flow
Authors: Hersey Mayo D.
Published: January 2006

Where rheological phenomena are too complex to yield readily to a detailed mathematical analysis, one naturally turns to the method of dimensions because of its successful use in the analogous problems of hydrodynamics, aerodynamics, and lubrication research.
On a Simple Model Explaining the Hardening Effect in Poly-Crystalline Metals
Authors: Hencky H.
Published: January 2006

The strain-hardening observed in poly-crystalline metals is also present in the elastic state, but is here hidden by the comparatively big value of the modulus of shear.

A simple microstructural model is described and statistically treated. The model shows all the features, which we observe in the tension- and compression-test, and explains the Bauschinger-effect and the brittleness after plastic strain.
The Influence of Nitrogen in Mild Steel on the Ability of Developing Flow Layers
Authors: MacGregor C. W. , Hensel F. R.
Published: January 2006

Certain mechanical conditions necessary for successful etching of flow layers are described. Etching tests on various materials with different nitrogen contents are discussed showing that those materials with the higher nitrogen content below certain limits produce the most clearly developed flow layers in etching. In addition, two methods of improving the etchings received from various materials by artificially introducing nitrogen into the surface layers are described.
The Cause of Fluctuations in Rising Mixtures of Gas and Liquid
Authors: Versluys J.
Published: January 2006

In a paper of 1928 the author dealt with the factors which interfere with the flow of mixtures of gas and liquid in vertical channels, and again in English in 1929. In these two papers a cause of intermittency was already mentioned, viz., that although there may be sufficient gas to establish the mist condition as described below, when the rate of speed of this fluid is smaller than the differential velocity of gas and liquid, drops of liquid cannot be lifted by the gas. Liquid then, if continuously supplied, collects at the bottom and can only be lifted when enough of it has been gathered so that for some time a foam is formed.
Some Physical Properties of Wiping Solders
Authors: McLean D. A. , Peek R. L. , Schumacher E. E.
Published: January 2006

The plasticity of a number of solders at wiping temperatures has been determined by compression tests between parallel plates. The character of the flow is found to be that corresponding to a linear relation between shearing stress and a fractional power of the velocity gradient. This corresponds approximately to a relation between rate of compression (dhdt) and sample height (h) given by the equation: dhdt = khb, in which k and b are constants, of which b is independent of the test conditions. For viscous materials b = 5.0; for most solders b is greater than 5.0, and increasing values of b are associated with lower temperature gradients of plasticity. It is shown that a solder must have a low temperature gradient of plasticity in order to be properly wiped, and that determination of the value of b by means of a plasticity test can therefore be used to evaluate the working properties of a solder.

A number of factors upon which the plasticity of wiping solders and the porosity of wiped joints may depend have been investigated. In particular, it is shown that segregation is not responsible for porosity, but that the latter may be dependent upon the particle size of the solid phase at wiping temperatures. The relation of particle size to the wetting power of the liquid phase is discussed.
Thixotropy and Plasticity. I—The Measurement of Thixotropy
Authors: McMillen Elliott L.
Published: January 2006

Thixotropy is a reversible sol-gel transformation in which a gel can be liquefied, and thus changed to the sol condition, by mechanical disturbance—such as shaking or stirring—and after agitation ceases will, with time, again revert to the gel condition. All thioxtropic materials so far investigated have been two-phase systems, of which one phase is generally solid and the other liquid. The present investigation deals with measurements of the thixotropy of paints undertaken to arrive at a more complete understanding of their flow characteristics, especially under the influence of extremely small shearing forces. While paint has long been recognized as a plastic material, its thixotropic nature has not been generally appreciated, although “false body” observed in some paints is a manifestation of thixotropy. Williamson attempts to calculate a “false body constant” for any paint, basing his calculations upon plasticity data, and failing to realize that the presence of “false body” in all paints requires all paints to be thixotropic. In addition Williamson has failed to appreciate the full significance of the mutual presence of plasticity and thixotropy. As has been previously pointed out by the author, Williamson's treatment of the subject is far from satisfactory in the practical case of evaluating leveling ability of paints. Other investigators of the plasticity of paints have, in general, either not recognized the presence of thixotropy or else ignored it.
The Mixture Law
Authors: Bingham Eugene C. , Brown Delbert F.
Published: January 2006

When two liquids are mixed in a certain ratio, it would not appear to be a very difficult problem to calculate the fluidity of the mixture, provided that the properties of the pure components are known and they are inert. In fact the problems at first appeared to be so simple that the assumptions involved were not even considered. After many years of groping for the solution, we have arrived at the conclusion that the problem is still unsolved. An important investigation in this field concludes: “The results of this paper also are consequently indecisive. All previous formulas are certainly useless.” A textbook of Rheology puts it succinctly, “The law of ideal mixtures is unknown.” It is not altogether unsatisfactory that the old erroneous assumptions have been admitted to be unworthy of confidence. As Hatschek says, “The ideal mixture curve for viscosity is almost certainly not a straight line.” This at least opens the way for new work, however.
Thixotropy and Plasticity. II—An Empirical Equation Expressing Thixotropic Fluidity Changes
Authors: McMillen Elliott L.
Published: January 2006

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.