bluuebunny/crossref_metadata_2025 huggingface dataset:
The Concept of Erosion Strength
Authors: Thiruvengadam A.
Published: August 2009

In general the problem of erosion of materials can be divided into two categories. One is the understanding of the threshold for each material wherein the impact stresses reach a limiting value just sufficient to initiate detectable erosion either at the first blow or after repetitive blows. Evidence is presented to show that the dynamic yield strength of a material controls the threshold for the single impact whereas the endurance limit is the important property representing the threshold for multiple impacts. The second problem is the prediction of the amount of damage if the erosive forces are above the threshold for the material. The designer needs some numerical value of a property that governs the volume of erosion of a material. As of now there is no single property that can be used for this purpose just as we use various properties of materials to represent their response to static fatigue and creep loadings. A recent suggestion to use the strain energy of the material as given by the area of the stress-strain diagram from a simple tension test has a few limitations such as strain-rate effects environmental effects (for example temperature and corrosion) and the scarcity of stress-strain data under these conditions. In order to overcome these limitations a new concept known as erosion strength is introduced and it is defined as the energy absorbed per unit volume of material up to fracture under the action of the erosive forces in various environments. The methods to determine the erosion strength from an erosion test are outlined. If the concept is accepted by the engineering profession erosion strength would take its place among the other mechanical properties of materials such as yield strength ultimate strength fatigue strength creep strength hardness and corrosion fatigue.
Material Destruction Due to Liquid Impact
Authors: Hoff G. , Langbein G. , Rieger H.
Published: August 2009

A survey is given of the rain erosion behavior of all classes of materials in the drop-impact velocity range between 200 and 400 m/sec. The results are compared with the cavitation behavior of matter and with the results of single water jet impact test. The dependence of the erosion properties upon velocity, angle of incidence, and drop size has been studied. If the materials are to be classified by increasing rain erosion strength of the most resistive representative of a material class, the order is the following: glasses, plastics, ceramics, and metals. The process which produces cracks and the material breakup is explained. The net result of this explanation provides guides for developing materials with improved erosion strength. By the energy balance of the erosion process, relations between the erosion strength and the mechanical properties of materials are given, and characteristic parameters for describing the erosion properties are proposed.
On the Time Dependence of the Rate of Erosion Due to Impingement or Cavitation
Authors: Heymann F. J.
Published: August 2009

Increasing attention is being given to the observed variations in the time rate of weight loss during impingement and cavitation erosion testing. It is generally recognized that a fuller understanding of these variations is needed for more meaningful use of the test results and more insight into erosion mechanisms. A pattern often observed is that of an initial period of little or no weight loss, successively followed by a period of high rate of loss and one of diminished rate of loss. Some results, however, follow other patterns, such as a continuously declining rate or a continuing sequence of fluctuations. There has been no full agreement concerning the causes for, and the significance of, the various phases. Part I of this paper reviews the pertinent findings in the literature and discusses each of the following influences in some detail: (a) The effect of the geometrical changes in the eroded surface on the macroscopic flow, cavitation, or impingement conditions which determine impact severity. (b) The effect of the metallurgical and geometrical changes in the surface on the resistance of the surface to the impacts. (c) The relative significance of the various material-removal mechanisms, such as single-impact failure, fatigue failure, and corrosion. Part II develops a tentative statistical model of the erosion process for the case where fatigue is the predominant failure mechanism. The analysis predicts rate-time patterns similar to many of those observed, and it leads to the conclusion that the instantaneous erosion rates during nonsteady periods are strongly dependent on the scatter associated with finite fatigue life and with test parameters such as bubble or drop diameters. While the analysis predicts the eventual attainment of a steady-state rate independent of that scatter, this state is probably often unattainable in practice because the increasing roughness of the surface itself affects the erosion rate.
Correlation of Cavitation Damage with Other Material and Fluid Properties
Authors: Garcia R. , Hammitt F. G. , Nystrom R. E.
Published: August 2009

Ultrasonic-induced cavitation studies were conducted in lead-bismuth alloy at 500 and 1500 F, in mercury at 70 and 500 F, and in water at 70 F for a wide variety of materials, including refractory alloys, steels, brasses, copper, nickel, and plastics. Correlations of the cavitation damage with applicable mechanical and fluid properties were carried out. Some conclusions are: 1. Damage rates in mercury were 3 to 20 times greater than in water, depending upon the material. Hence, clearly no correlating equation which considers only the mechanical properties of the material can apply for both fluids. 2. There is no single material mechanical property which can be used to correlate the damage, even if coupling parameters to account for fluid property changes are included in the correlation. 3. In general, the best correlations include energy-type mechanical properties, strength-type properties, and fluid coupling parameters. 4. No relatively simple single correlating equation applies well to all the data. This may indicate the insufficiency of the statistically determined mechanical and fluid properties for the correlation of cavitation damage which is known to be a highly transient process.
The Effect of Evaporative Cooling in Saddle Fuel Tanks on Diesel Engine Operation
Authors: Barnard D. P. , Fleming R. H.
Published: August 2009

Over-the-road truckers have experienced power loss and in some cases engine stoppage due to blocked fuel filters during the winter. The cause is the refrigerating effect of brine evaporating from the surfaces of exposed fuel tanks, lowering the fuel temperature far enough below ambient to cause either wax precipitation or ice-crystal formation. Experimental work on the road shows that evaporative cooling can result in a 6 to 8 F drop in fuel temperature, depending upon external conditions. Though wax-crystal formation can be the cause of filter plugging with marginal fuels, there is a larger and more significant effect due to ice-crystal formation from water in the tank bottoms, originating in the fuel-distribution system or by condensation through vehicle tank breather.
The Effect of Pour-Point Depressants on Diesel Fuel Performance in Winter
Authors: Mickel B. L.
Published: August 2009

The effect of pour-depressant additives on the low-temperature filterability of diesel fuels has been studied in the laboratory with vehicle simulators. The benefits imparted by pour depressants depend upon both fuel-system design and fuel type. The most critical part of the diesel fuel feed system is the suction filter or screen. High-density cracked fuel appears to be more depressant responsive than all-virgin products. Pour-point depressants in these responsive fuels delay blocking of the suction filter by wax. In a well-designed system, depressants can extend the warm-up period sufficiently to permit continued operation; performance of the vehicle is extended well below the traditional cloud-point limit. By simple changes of fuel-system design, even further advantage can be taken of the flow-improving properties of pour-depressant additives.
Diesel Power, Economy, and API Gravity
Authors: Lindeman R. P. , Lawrence D. K. , Wagner T. O.
Published: August 2009

Whether fuel density influences power and economy of diesel engines enough to be an important fuel specification has caused much controversy. To resolve this question, power and fuel consumption of five engines and three trucks were carefully measured with diesel fuels ranging in gravity from 29 to 45 deg API. In all engines at all speeds and loads, maximum power declined only 0.3 per cent, and fuel consumption increased only 0.3 per cent per degree increase in gravity. We conclude that only small variations in power and economy result from differences in gravity among commercial fuels.
Cleaner Injectors and Less Smoke with Hydrogen-Treated Diesel Fuel
Authors: Irish G. E. , Wiseman E. L.
Published: August 2009

Although No. 2 diesel fuels all give about the same amount of exhaust smoke when compared in an engine over test periods of a few minutes, they differ greatly in their injector-fouling rates during long-term engine operation. Thus, differences in smoke and full-throttle power output caused by differences in injector-fouling rates are vastly more important to the diesel operator than short-term smoke. Fuels lacking sufficient thermal stability permit rapid deposit buildup in injectors and on spray tips. The result is increased exhaust smoke, loss of power, and shortened injector life. Hydrogen treating improves the stability of diesel fuel and promotes long injector life. In truck tests under severe operating conditions, injector life with hydrogen-treated fuels was two to three times that obtained with straight-run fuels. Smoke-suppressant additives are now available to alleviate heavy smoke emissions from problem vehicles. One of these also cleans most fouled injectors in 3000 to 6000 miles.
Mechanics of Ink Transfer During Impact Printing
Authors: Slaughter G. T.
Published: August 2009

Discerning customers and more rigorous applications of impact imaged documents demand better understanding of ink release from typewriter ribbons. Considerable effort has been expended toward this end; unfortunately, the results of this effort have not been utilized fully by printing mechanism designers and ink formulators. For this reason an attempt is made to bridge the gap between mechanical and chemical variables by addressing those parameters affected by both. Regarding ink transfer from carbon or film ribbons, the transfer mechanism involves brittle fracture at character edges and release by generation of a shear stress at the ink substrate interface or within the ink film, depending upon the physical nature of the film. Evidence supporting this theory has been collected through literature search, observation during printer and ribbon development, and from measurements of ink release stresses.
The Current Status of Fretting Corrosion
Authors: Campbell W. E.
Published: August 2009

A general discussion of fretting wear of metal surfaces is presented. It is concluded that the phenomenon is not corrosion in the usual sense, but wear due to oscillatory relative motion of sufficiently high amplitude to cause gross slip between the contacting surfaces, accelerated in certain cases by abrasive oxide films formed as a result of the wear. The only measure which eliminates wear entirely is the elimination of gross slip between the metal surfaces. This can be done by reducing the amplitude of the oscillatory motion or by interposing between the surfaces a material of high enough shear elasticity to prevent gross relative motion. Other methods of mitigating fretting are discussed and suggestions for future research on the mechanism are given.
Fretting Corrosion Tendencies of Several Combinations of Materials
Authors: McDowell J. R.
Published: August 2009

A large number of combinations of materials, both metallic and nonmetallic, were subjected to conditions producing fretting corrosion in an effort to evaluate their comparative susceptibility to this action. A table is given listing the results in three groups of relative resistance. Observations were also made to determine qualitatively the effect of such variables as velocity of slip, pressure between surfaces, amount of slip, and surface finish. All rigid materials were found either to corrode with oxide debris or to be affected by a fretting action which roughened the surface. Two contradictions to published data were found in that magnesium on cast iron is a poor combination and that surface roughness has little effect. Some nonmetallic materials are worse than metals. Dry lubricants delay the action, whereas rubber cement by excluding air prevented corrosion during the test life. A rubber gasket completely stopped the corrosive action.
Influence of Fretting Corrosion on the Fatigue Strength of Fitted Members
Authors: Horger Oscar J.
Published: August 2009

Closely fitted design members, which are clamped, pressed, or shrunk together develop fretting corrosion between the mating surfaces when subjected to fluctuating stresses. Aside from the wear which changes the geometry of the mating surfaces, there also results a greatly reduced fatigue resistance. It is this latter aspect, along with means of improving the fatigue resistance, that is discussed here because of the increasing number of service failures occurring in all types of machinery and equipment due to fretting. This paper first discusses the fundamental nature of the fatigue problem associated with fretting. Eight factors are then separately treated as to how each one influences the fatigue strength regarding both the initiation and propagation of fatigue cracks. These factors include the effects of the degree of the clamping pressure, shape or geometry of assembly, fretting, residual stresses, different engineering steels and heat treatments, surface finish, simultaneous water corrosion, and type of lubricant used between the mating surfaces. After reviewing these factors it is apparent that some limited improvement in fatigue resistance may be obtained against the initiation of fatigue cracks due to fretting. Means are available for obtaining much greater improvement in fatigue resistance against fatigue crack propagation.
Introduction
Authors: Barber Edward S.
Published: August 2009

In principle, determination of the permeability of soils is quite simple. However, due to natural variations of material in place, it is often difficult to relate tests on small samples to larger masses. In sampling soils it is hard to prevent disturbing the moisture or density or particularly the structure of the soil. Changes in the air or chemical or organic content of the permeating fluid can cause large differences. Migration of particles may occur both in the field and laboratory. While some variables can be arbitrarily controlled or eliminated in the laboratory, it is often necessary to consider them in field applications. The Symposium includes papers discussing the importance, evaluation, and control of most of these factors. Field permeability tests are compared, described, and evaluated by formulas. Correlations are presented between permeability and density and gradation of granular materials. A new sampler and a device for testing under small gradients are described. The importance of relating tests to field conditions is stressed. The test value is expressed as length divided by time in a variety of units, but it is generally called coefficient of permeability, although hydraulic conductivity is suggested as being more consistent with other fields such as electrical and thermal conductivity. While the variety of field situations seems to preclude a single standard test method, it should be possible to increase the consistency of results by recommendation of preferred practices.
A Low-Head Permeameter for Testing Granular Materials
Authors: Yemington E. G.
Published: August 2009

Highway drainage designs generally have been based upon empirical rules, and only in recent years has the importance of obtaining permeability data on granular materials been stressed for the design of sand drains and blanket courses used in embankments for assisting in the removal of water by consolidation of the subsoils. In 1952, the Bureau of Public Roads published a report on highway subdrainage. The report did not establish design criteria but it did present test methods, a new type of low-head drainage-lag permeameter, and data on the permeability and drainability of soils and their applications to highway subdrainage. This paper presents additional test data and information on the above-mentioned drainage-lag permeameter for the measurement of permeability coefficients of open-graded granular materials. Comparisons are made between the coefficients of permeability obtained by this device and an ordinary falling-head permeameter for eight gradings of granular material. The results of these tests indicate that the drainage-lag type of permeameter minimizes turbulence in permeability testing and can be used to measure higher permeability values than the ordinary falling-head type of permeameter.
Permeability Test for Sands
Authors: Chu T. Y. , Davidson D. T. , Wickstrom A. E.
Published: August 2009

Information on the permeability of sand is often required in its utilization as an engineering material. This paper presents a modification of Barber's falling head permeability test for porous granular materials. The modified method is simple to use and gives reproducible results. The modifications recommended include: (1) a procedure for loading and compacting the sample in the permeameter tube, (2) a carbon dioxide treatment to remove air from the sample, and (3) the repeated testing of the loaded sample until permeability values obtained are within a recommended range of variation. The suggested permeability test was used to measure the permeability of several Iowa sands at various densities. Compositional information pertinent to the permeability of the sands is also presented.
The Permeability and Settlement of Laboratory Specimens of Sand and Sand-Gravel Mixtures
Authors: Jones Chester W.
Published: August 2009

This paper describes the procedure and results of laboratory permeability-settlement tests on samples from a river deposit containing about half sand and half gravel. The tests were conducted (1) on specimens containing the sand fraction passing the No. 4 sieve, (2) on specimens containing the sand fraction plus various percentages of gravel with 3/4-in. maximum particle size, and (3) on specimens containing the sand fraction plus various percentages of gravel with 3-in. maximum particle size. The tests of (1) and (2) above were made on specimens of 8-in. diameter and 5-in. height, whereas those of (3) were made on large-scale specimens of 19-in. diameter and 9-in. height. The specimens were placed at different densities, and settlements were measured during a definite loading schedule during the permeability test. The results show that the permeability of both the small and large specimens containing 20 to 50 per cent gravel was considerably less than the permeability of the sand fraction alone. In addition, the permeability of specimens containing the 3/4-in. material was somewhat greater than those containing the 3-in. material. The permeability decreased with increase in placement density and, with the exception of the specimens containing 3/4-in. material, decreased with increasing load. The settlements increased with load and generally increased with gravel content. The study shows that the differences between the results of the small and large-scale tests are sufficient to justify the use of the latter where a reasonably close value of the permeability is required.
Determination of Permeability of Granular Soil by Air Subjected to a Decreasing Pressure Differential
Authors: Weaver Arthur S.
Published: August 2009

The object of this paper is to describe the design and operation of an apparatus for determining the coefficient of permeability of granular soils, utilizing air as the percolating fluid, under so-called falling-head conditions. Also, the results of a few typical tests are presented, and comparisons made with the results obtained using water as the test fluid.
Engineering Geology of Straight Creek Tunnel Site, Colo.
Authors: Robinson C. S. , Lee F. T.
Published: August 2009

The U. S. Geological Survey, as part of a research program on geologic and geophysical methods of predicting geologic conditions at depth for the construction of underground openings, is conducting in cooperation with the Colorado Department of Highways a study of the site of the pilot bore for the Straight Creek Interstate Highway tunnel under the Continental Divide in Colorado. A statistical model of the geology at the depth of the tunnel was developed as a result of the field and laboratory research. From this model, predictions have been made as to probable rock load, spacing of sets, areas to be tested by feeler holes, the amount of grout required, average flow of water as the heading is advanced, and the maximum initial flow of water that might be expected from broken ground within any interval of the tunnel. During construction of the pilot bore, the accuracy of the predictions can be evaluated, which will lead to better methods of predicting geologic conditions and making engineering estimates for other proposed underground openings.
Subsurface Exploration by Sonar Seismic Systems
Authors: Reenan E. D. Van
Published: August 2009

The Boomer and the Pinger probe sonar seismic systems which are used for subsurface investigations in water-covered areas are described. The Boomer is used for deep sediment penetration studies, and the Pinger probe is used for detailed, high-resolution, shallow penetration work. The Boomer produces a low-frequency, high-energy pulse using a high-voltage discharge into an electromechanical transducer which produces an eddy-current plate repulsion. A continuous recording process produces a record of the reflections from the water-bottom and sub-bottom interfaces. The Pinger probe employs a short, high-intensity, 12-kc pulse from a crystal transducer. Recording is accomplished by a small, high-resolution Alden helix recorder. A number of examples of records are presented from each system.
Mechanical Methods of Undisturbed Soil Sampling
Authors: Clark K. R.
Published: August 2009

This paper discusses several methods used by the Bureau of Reclamation for the undisturbed sampling of soils including open-drive piston and double-tube core-barrel sampling. The paper describes in general terms how research studies have resulted in techniques now standardized. Included are recommendations for sampling saturated and unsaturated soils; expansive and nonexpansive materials; and loose, alluvial, and colian soils. An important consideration is the method by which the holes are stabilized with drilling mud.
“NX” Bore-Hole Camera
Authors: Trantina J. A. , Cluff L. S.
Published: August 2009

The “NX” bore-hole camera was designed and developed by Remington-Rand Corp. and the Army Corps of Engineers for photographing subsurface conditions on the walls of small-diameter borings in rock. The increasing practicality and availability of such equipment for foundation studies and mineral explorations is creating further interest in its use in the study of rocks, some soils, and even in large but otherwise inaccessible openings. Some of the camera's capabilities are presented with techniques of operation and methods of interpretion of geologic features as photographed on either colored or black and white film. Each film frame is a doughnut-shaped picture of a section of the wall of a hole. A graphic method is described for interpreting from a flat photograph the true orientation of the features on the wall of the hole, such as fractures, mineral veins, or geologic contacts and also for determining the true lengths of the lines on the projection. Some examples of interpretative results are also given.
The Detection and Interpretation of Microseismims in Soil Masses
Authors: Fisher C. P. , Yorke C. A.
Published: August 2009

This paper presents a description of an experiment to determine the feasibility of extending a stability investigation technique developed for sound rock for use in soil materials. Experimental results are presented along with detailed descriptions of the field test sites. The results presented show that microseismims are generated in soil materials. There is a strong indication that there is a relationship between microseismic rate and slope stability.
Theory of, and Appropriate Methods for Measurement of Surface Emittance
Authors: Herrington L. P.
Published: August 2009

Current interest in the measurement of infrared heat emission and absorption of structural materials is discussed. Distinctions between the emission characteristics of materials in the visible and heat radiation regions of the spectrum are made. The terminology of radiation exchange is reviewed from the standpoint of simplicity and usefulness in a standardized test suitable for use with structural materials as non-incandescent temperature radiators. Basic laws of radiation exchange are briefly reviewed. On the basis of the foregoing considerations, the plan of an apparatus construction for surface emittance measurement in the 0 to 300 F range is described.
Methods of Measurement and Application of the Theory of Specific Heat to Thermal Insulating Materials
Authors: Spear Norman H.
Published: August 2009

This paper describes the present status of specific heat in thermal insulating material design relative to building, piping, and clothing insulants. Test data are presented for summer diurnal temperature variations imposed upon the exposed walls of two similar structures of different specific heats. Comfort and economy features are demonstrated and related to high heat capacity. An “index of thermal response” is suggested as a basis of improved building insulation design. Piping insulation is discussed briefly. The hygroscopic value of clothing and the resultant effective specific heat is discussed as a factor affecting comfort through body heat conservation. A tentative test method for insulant specific heat measurement, under consideration for standardization, is briefly described, and the progress of this test development is reported.
Introduction
Authors: Catton Miles D.
Published: August 2009

For over a quarter of a century, persons interested in the field of soil mechanics have been attempting to point out and to emphasize the importance of the strength and supporting power of soil masses when they are used as an engineering material. In many cases in engineering practice, the usefulness and economic life of a structure can be measured by the supporting power of the soil upon which it rests. Unfortunately, that supporting power is difficult to determine for two important reasons. First, the nature of the soil mass itself is complex and, second, the factors which determine strength are not constant. As a consequence, the problem is one of dynamics rather than of statics. In dealing with natural soil deposits, one is essentially dealing with a three-phase soil system—a system composed of soil particles, water, and air. It is obvious that the geologic and pedologic nature of the soil particle itself will contribute to its behavior. The second and vital factor is the variable rôle played by contained water and air upon the nature and qualities of this system. This is a complicated factor. It is one which, in conjunction with the surface chemistry of the soil particle, gives the system its capacity for change and introduces the need for applying dynamic analysis methods. It follows that a reliable method for the determination of both the water content and the density of the soil mass in place is a first step toward a better understanding of the vital problem of soil strength analysis.
Use of Radioactive Material to Measure Soil Moisture and Density
Authors: Belcher Donald J. , Herner Raymond C. , Cuykendall T. R. , Sack H. S.
Published: August 2009

The need for convenient instruments to measure soil moisture and density in place in a quick, reliable, and possibly continuous manner has long been felt by soils engineers. This paper summarizes the work done up to this time by the Civil Aeronautics Administration and Cornell University on the nuclear meters that are designed to solve the problem. The method presented here makes use of the physical principles of the scattering of neutrons and gamma rays. A source of proper radiation, radium D-beryllium or cobalt 60, is contained in cylindrical probes along with a detector of slow neutrons or of gamma rays, respectively. The probe is inserted into the soil mass through a 1-in. diameter pipe, and the radiation penetrates the nearby soil and is scattered back toward the detector, the amount and character of the scattered radiation giving a measure of the characteristics. The design and testing of such probe meters that measure soils at depth and of the related surface meters that measure thin-layered soils are described in detail. With suitable care, the probe meters measure moisture to ±1 lb of water per cu ft, and measure density to ±5 lb of soil per cu ft. The surface meters are in an earlier experimental stage and are not so accurate. The time required to take a complete set of readings is about 15 min. Further laboratory and field testing is being conducted to perfect these meters to fulfill specific requirements of different engineering projects.
Introduction
Authors: Mielenz Richard C.
Published: August 2009

Committee D-18, on Soils for Engineering Purposes, early recognized the significance of physico-chemical properties of soils in engineering, and in 1947 Subcommittee R-6 on Physico-Chemical Properties of Soils was organized to deal with this field. The present Symposium was authorized by Committee D-18 at the Annual Meeting in June, 1951, at Atlantic City, and placed under the sponsorship of Subcommittee R-6. The speakers emphasize the influence of molecular and ionic exchange upon properties and responses of soils. This relationship leads to methods by which soils are altered to achieve adequate engineering performance even under adverse circumstances. They demonstrate, too, that exchange phenomena are dynamic. Consequently, exchange equilibrium might be modified by changes incident to construction, or exchange effected purposefully to achieve stabilization might be undone by natural processes. Mr. R. E. Grim summarizes exchange reactions occurring in earth materials and the underlying reasons for resulting changes in properties. He notes especially the relative exchangeability of various ions, and the changes induced by exchange reactions in adsorbed water hulls and state of aggregation in soils. This paper sets the stage for the four papers dealing with engineering properties and experience.
Ion Exchange in Relation to Some Properties of Soil-Water Systems
Authors: Grim Ralph E.
Published: August 2009

Clay materials, including soils, have the property of sorbing certain cations and anions and retaining these in an exchangeable state; that is, these ions are exchangeable for other cations and anions by treatment with such ions in a water solution (the exchange reaction may also take place in some nonaqueous environments). The exchange reaction is stoichiometric. A simple and well-known example of the ion exchange reaction is the softening of water by the use of zeolites, permutites, or carbon exchanges. The discovery that soils have the power of exchanging cations with solutions containing other cations is the outgrowth of observations dating back into the remote past. For example, it has been known for centuries that liquid manures become decolorized and deodorized when filtered through soils. Thompson about 1850 is generally credited with first systematically studying cation exchange. He showed that when soils were mixed with ammonia and then leached with water, the greater part of the ammonia was held back. Shortly after Thompson's work, Way, another Englishman, began a detailed study of the phenomenon. It was Way who first showed that cation exchange in soils was restricted to the clay fraction and that it was connected with the silicate compounds in the soil. Following the pioneering labors of Thompson, Way, and others, a large number of investigators, particularly in the field of soil chemistry, have studied various aspects of the exchange reaction. The term base exchange was used for many years to describe the cation reaction long after it was established that the hydrogen ion may take part in the exchange reaction. Indeed the term base exchange is frequently still used at the present time.
Job Experience with Exchange Phenomena Involving Inorganic and Organic Ions
Authors: Winterkorn Hans F.
Published: August 2009

Job experience with exchange phenomena acquired during two decades is coordinated with the main results of parallel theoretical and laboratory developments. The consciously chosen frame of reference is a general scientific one which it is hoped may even deserve to be termed philosophical. It is this general or philosophical type of thinking which led the French gardener Monier to the invention of reinforced concrete and the French engineer Freyssinet to the development of prestressed concrete. At the present state of development of the science and practice of soil stabilization, qualitative thinking is of paramount importance and premature exclusive emphasis on the quantitative may well stymie the growth of this important discipline.
Surface Chemical Properties of Clay Minerals and Soils from Theoretical and Experimental Developments in Electroosmosis
Authors: Winterkorn Hans F.
Published: August 2009

The theoretical concepts of Helmholtz and Schmid are analyzed with respect to their consequences on electroosmotic water transmission in clay systems as a function of their porosities. New experimental evidence is adduced which proves the general validity of the Schmid concept, but which also shows a determinant influence of the hydration behavior of the system on the electroosmotic transmission picture. This influence makes electroosmosis a new and promising, non-destructive tool for probing into the hydration behavior of clay and similar systems. For this purpose, a simple apparatus was designed which permits measuring of electroosmotic transmission in swelling systems at definite porosities that remain unchanged throughout the experiment.
Mass Spectrometric Analysis of Solids with the High-Frequency Spark
Authors: Hipple J. A. , Gorman J. G.
Published: August 2009

Earlier work with the high-frequency vacuum spark in mass spectroscopy is reviewed briefly. A suitably designed system of monitoring the ion current produced by this type of source permits the application of the techniques of electrical detection in place of the method of direct photographic detection previously required for such an erratic source. This analytical method for solid samples is described and some illustrative analyses are presented.
Mass Spectrometric Analysis of Copper for Cuprous-Oxide Rectifiers
Authors: Hickam W. M.
Published: August 2009

A number of analyses of Chilean coppers used for cuprous-oxide rectifiers have been made by the following methods: (1) mass spectrometric analysis of a molecular beam obtained by vaporization of the copper samples, and (2) mass spectrometric analysis of gas obtained using vacuum fusion techniques. The results from a number of analyses are presented and correlation with rectifier performance indicated.
Introduction
Authors: Fieldner Arno C. , Anderson W. W.
Published: August 2009

I wish to express a very deep appreciation of the vision of Chairman W. W. Anderson of Committee D-5. on Coal and Coke, and of the work of Henry F. Hebley, Chairman of Subcommittee XIII on Coal Sampling, and of W. M. Bertholf, Chairman of the Section on Mechanical Sampling. They have done a marvelous job of getting together a group of outstanding papers. As Bertholf says in the introduction to his paper, progress in sampling coal has not been continuous since the publication of E. G. Bailey's classical paper in 1909. There have been considerable periods when all was quiet on the Potomac, as we say in Washington, with not much doing on the theory of coal sampling. Then somebody had a new idea, and interest was renewed. Grumell and Dunningham disturbed a comparatively quiescent period of nearly two decades when they conducted their mathematical and experimental studies in the late twenties. Their work led to the adoption of revised methods for sampling coal by the British Engineering Standards Assn. in the early thirties. ASTM Committee D-5 took up this challenge and appointed Subcommittee XII on Sampling Coal at Coal-Cleaning Plants, under the chairmanship of T. W. Guy, in 1932, and Subcommittee XIII on Mechanical-Sampling and Reduction of Samples, under the chairmanship of J. B. Morrow, in 1934.
The Development of the Theoretical Basis of Coal Sampling
Authors: Bertholf W. M.
Published: August 2009

This paper is a review of the two main lines of investigation which preceded the over-all attack of the problem of coal sampling by L. A. Bushell in 1937. The paper shows that the “simple” experiment fails to disclose the true nature of the problem. Use of the techniques introduced by R. A. Fisher et al. permits the evaluation of the sampling constants of a coal, and thus the formulation of a satisfactory sampling procedure. Certain simplifications of these techniques will permit the accumulation of variance data without undue expense. The methods of Visman, Tanner and Lerner, and those currently in use in Britain are compared with the direct analysis of variance.
Some Recent British Work on Coal Sampling
Authors: Tomlinson R. C.
Published: August 2009

Interest in coal sampling in the United Kingdom has received a great impetus in recent years for a number of reasons. The nationalization of the coal industry itself and of two of the major coal-consuming industries, gas and electricity, has resulted in three very large commercial organizations with a large annual sampling bill. Then, more recently, the National Coal Board introduced a revised price structure whereby the pithead price of a coal is determined largely by its chemical analysis. This has meant that, more than ever before, there is a commercial incentive towards obtaining detailed information on the properties of the many hundreds of grades marketed each day. This increased commercial interest has arisen at a time when the introduction of various new ideas about sampling had led to a renewed theoretical and statistical examination of the subject. As a result much experimental work has been carried out, providing a considerable amount of sampling data. The results of some extensive experiments carried out for the British Standards Institution in 1950–1951 have been reported by E. H. M. Badger, Chairman of the committee concerned (1). The main conclusions, so far as they affect a sampling specification, were that the weights of sample prescribed in the existing standard were not far from correct but that two changes would be required in future specifications: first, more attention would have to be paid to the errors of reduction and analysis, particularly when an attempt is made to obtain the very high degree of accuracy demanded by engineers in charge of boiler trials; second, provision should be made for the measurement of sampling accuracy from the results of routine sampling using the technique known as duplicate sampling (2). A further conclusion, and one of perhaps wider importance, was that the science of coal sampling could not be built on theories of coal sampling but must be based empirically on measurements carried out under a wide range of conditions. This is no new discovery, but until recently there was no very satisfactory technique for carrying out the measurement. However, with the help of some of the techniques used by statisticians for other sampling problems, the work of measurement is now moving forward, and indeed the main theoretical interest has been in developing further new and simple techniques. It is the intent of this paper to describe the line of effort which has been carried out during the past three years, and to illustrate those techniques of measurement which seem to be of most interest and lasting value, and finally to describe the way in which the conclusions that have been reached are being incorporated into a revised specification. Much remains to be done, however, before the revision of this specification can be completed.
Tests of Accuracy of a Mechanical Coal Sampler
Authors: Coryell R. L. , Schwerd F. J. , Parente E. J.
Published: August 2009

A program for testing accuracy of an established mechanical coal sampling procedure is described and applied. Each step in the sampling procedure was tested for presence of bias and no significant bias was found. Sampling tests were made on a lot of mixed coals totaling 13,600 tons and the results analyzed for variances. For these coals, it is shown statistically that the ASTM accuracy required for commercial coal sampling by ASTM Standard Method D 492 - 48 may be obtained for any size lot by taking the number of increments (50 lb each) required by the ASTM procedure for lots of less than 1000 tons. However, to obtain the ASTM special purpose sampling accuracies, a single gross sample of these coals will not suffice.
Tests of the Geary-Jennings Sampler at Cabin Creek
Authors: Bertholf W. M. , Webb W. L.
Published: August 2009

ASTM requirements covering the sampling of coal were intended to be used for “hand” sampling; they do not cover the cases in which very large (100-lb) increments are taken. The question of the propriety (or necessity) of using the same number of increments in these cases as is prescribed for small (2 to 10-lb) increments collected by hand was raised by the junior author early in 1949, in correspondence with ASTM Committee D-5 on Coal and Coke. At the same time, the automatic sampling question was being investigated by the Power Station Chemists' subgroup of the Prime Movers Committee of the Edison Electric Inst. It was only natural, then, that sooner or later a study group would evolve, which would include representatives of both committees and a sprinkling of consulting members. In the preliminary stages of the work, this study group was informal, and it was not until a draft proposal for a comprehensive test of an automatic sampler was almost ready (spring of 1951) that any formal organization was attempted or official recognition requested. Currently, the work started by this small group is being carried on by the Mechanical Sampling Section of Subcommittee XIII on Coal Sampling of ASTM Committee D-5 under the chairmanship of the senior author.
Tests on the Binomial Sampling Theory for Heterogeneous Coals
Authors: Visman J.
Published: August 2009

Broken coal leaving the mine can be considered to consist of two components, “coal” and “rock,” found from a density-separation at roughly 1.60 specific gravity. The object of the following study is to investigate whether this two-component mixture—which is admittedly artificial—can be used for predicting the considerable variances in ash found in most raw coals, by applying the binomial formula for ash developed earlier (2). The ash variance for single pieces, it is noted, may vary from, say, 10 to about 3000, due to the sometimes strongly bimodal distribution, whereas the trend variance is only of the order of 10. The ash variance is also considerably larger than the variances of other constituents, for instance, moisture or sulfur. The sampling procedure for ash is therefore in a class apart, and it stands to reason that even a first approximation of this “binomial variance” would be of great practical value in finding the minimum weight and number of increments for a preassigned accuracy.
Extremal Nature of Dielectric Breakdown—Effect of Sample Size
Authors: Endicott H. S. , Weber K. H.
Published: August 2009

Data are commonly gathered to furnish information regarding the distribution of the quality characteristics of a material, usually for a specific purpose such as the establishment of a quality standard or the determination of confonnance with a specified quality standard. In 1933, a “Manual on Presentation of Data” (7) was published by the ASTM to make available some of the principles of efficient presentation of data and to recommend practices for the American Society for Testing Materials.” In this manual, consideration is given particularly to “a series of n observations representing single measurements of the same quality characteristic of n similar things.” The two distribution parameters said to be the most important are arithmetic average, X̄ and standard deviation, σ. Practically no mention is made of individual extreme values. Little attention was paid to skewed distributions and that little only to skewed normal distributions. It has become apparent in recent years that the normal law is not a good approximation to the distribution of values obtained from the operation of a process which is “weak-link” in character, that is, dielectric breakdown or mechanical rupture tests. A fundamental objection is that it does not obey the stability postulate. This means that only the reference distribution can be normal. Furthermore, it requires that the standard deviation as well as the mean decrease with increase in sample size. Types of distributions which do obey the stability postulate were presented by E. J. Gumbel (1) in a recent publication of the National Bureau of Standards. It is the aim of this paper to call attention to recent work which shows close conformity of dielectric breakdown data, for both liquids and solids, with one of Gumbel's “extreme-value” distributions. The consequences of this conformity on the rate of decrease of minimum breakdown values with increase in sample size or area are then discussed.
Variability of Dielectric Breakdown in Sheet Insulation
Authors: Graves H. K.
Published: August 2009

In addition to average values obtained from a number of measurements on a sample of material, users of dielectrics have long been interested in minimum property values for design and reliability purposes. Tensile strength, elongation, thickness and dielectric breakdown might be mentioned as some of the characteristics where minimum values have been of interest. Dielectric breakdown has perhaps been one of the most important of these and numerous attempts at control have been made over the years. Many specifications have carried a minimum average dielectric breakdown or dielectric strength requirement with a somewhat lower minimum value specified for any one reading. This method of control appears to give little protection to the user while at the same time requiring the manufacturer to take a very great risk if the minimum single value is set at all close to the average. If 1000 breakdowns were made on a sheet of varnished cambric, one or more of the values obtained would probably be quite low, lower at least than any limit which might reasonably be set for an individual breakdown. If 10 or as often happens only 5 readings are taken, it is a matter of chance whether one of these very low readings appears and the material must be rejected on the basis of a specified minimum individual value. Other specifications such as those for magnet wire, for example, have for years run a long specimen such as 100 ft through a conducting bath with a relatively low voltage perhaps 100 v or less impressed to pick out pin holes, or at best extremely weak spots. Such specifications permit some pinholes per hundred feet and it is probably safe to assume that magnet wire will not be tested by passing the entire lot through the electrode. High voltage wire on the other hand has been tested 100 per cent for many years at a relatively high voltage. Defects are cut out or repaired.