bluuebunny/crossref_metadata_2025 huggingface dataset:
DIFFUSION OF HELIUM THROUGH SEVERAL GLASSES*
Authors: Smith Paul L. , Taylor Nelson W.
Published: June 2006

Abstract

The rates of diffusion, R, of helium through four glasses of varied composition have been measured as a function of temperature up to and including the “transformation points” of the glasses. Two borosilicates, a lead glass, and a soda glass were studied, and the effect of heat treatment was investigated. A plot of log R vs. 1/T, in general, proved to be made up partly of a straight line and partly of a curving line at temperatures where the glass became soft enough to relieve strain. The borosilicates showed either no break or only a slight break at the “transformation point,” whereas the lead and soda glasses showed more pronounced changes in slope near the “transformation point.” The borosilicates showed a shift to higher rates with heat treatment; and the lead glass, a shift to lower rates. It is believed that completely annealed glass would show a linear log R vs. 1/T relation over the entire temperature range.

The permeability of the glass to the diffusion of helium at any temperature decreases as the percentage of basic oxides or of cations increases. This may be interpreted in terms of the atomic arrangement in these glasses.
STABILITY OF A KILN STACK*
Authors: Garve T. W.
Published: June 2006

Abstract

Mathematical proof is presented that the wind pressure on a round stack is two‐thirds that of a square stack with the wind square to one side. A reconsideration is given of a stack section1 where tension occurred, and a correction is presented. A convenient method and its application is also given for calculating the stability of a kiln stack upon the soil. The application of the “kern” theorem is discussed, using the kern for the worst condition, viz., with wind blowing diagonally against a square stack.
PROPERTIES OF CLAY CASTING SLIPS*
Authors: Loomis George A.
Published: June 2006

Abstract

Nine casting slips were prepared, using bodies of the sanitary porcelain type. The electrolyte was a combination of 60%“N” brand sodium silicate and 40% sodium carbonate. Its amount was adjusted in each body slip to produce a cast having the right characteristics according to the “feel” test; the specific gravity of each slip was constant. The grain‐size distribution of each slip was determined as well as the casting rate, consistency, and pH when the casting slips were first prepared and again after 24‐, 48‐, and 96‐hour aging periods.

There is a reasonably close relation between castability and the grain‐size distribution. The pH of the body compositions differed, but there was little or no change in its value with the age of the casting slip up to 96 hours. It is concluded that the determination of grain size and pH should be of considerable aid in the control of casting slips.
ZINC‐VAPOR GLAZING OF CLAYS: II, EFFECT OF VARIABLE LIME AND ALKALIS IN CLAYS ON ZINC‐VAPOR GLAZE COLORS*
Authors: Lampman C. Major , Schurecht H. G.
Published: June 2006

Abstract

A study was made of the influence of the lime content of brick on their ability to take zinc‐green, yellow, tan, and brown glazes. Desirable greens were obtained with clays containing as much as 3% lime; those with a higher percentage of lime generally produced yellow‐greens. The probability of obtaining good greens was best on clays with more than 6% of alkalis when their absorptions after firing were below 2%. Desirable greens were not obtained on bodies which had absorptions greater than 6.7%. Firing under oxidizing conditions before flashing and slow cooling tended to promote the formation of desirable brown, tan, and straw‐colored zinc‐vapor glazes.
NOTE ON CONE DEFORMATION STUDY IN PART OF THE SYSTEM CALCIUM OXIDE‐JRON OXIDE*
Authors: Rebs Kenneth , Fisk H. G.
Published: June 2006

Abstract

A series of cones prepared from dicalcium ferrite and ferric oxide was fired under oxidizing conditions. The cone of composition 60% dicalcium ferrite plus 40% ferric oxide consistently showed the lowest deformation temperature (2185°F.). According to the phase diagram for the system, the eutectic should be at about 20% dicalcium ferrite and 80% iron oxide (weight per cent). A possible explanation for the difference observed may be that liquids approaching the composition of monocalcium ferrite exhibit a lower viscosity than liquids formed at the eutectic.
EFFECT OF PARTICLE SIZE AND INDEX OF REFRACTION ON REFLECTANCE*
Authors: King Burnham W.
Published: June 2006

Abstract

The effect of particle size on the reflectance of thin semitransparent layers, such as enamels, was studied by using mixtures containing opacifying particles of definite sizes in an oil of known index of refraction. The mixtures were applied on a black glass plate, and the reflectance was measured. The coefficient of scatter per unit surface of the particles was calculated and was found to decrease slowly as the particle size decreased. On the other hand, for the range of sizes studied, the reflectance of the semitransparent layer increased rapidly as the particle size decreased.
REACTIONS TAKING PLACE DURING SMELTING OF SUPEROPAQUE ANTIMONY ENAMEL*
Authors: King Burnham W. , Andrews Andrew I.
Published: June 2006

Abstract

The reactions taking place during the smelting of a typical superopaque antimony enamel were studied by first determining the thermal effects which occur during the smelting of the raw batch and then by investigating the reactions which produce these effects. By this method, it was found that up to 500°F. the chief reaction was the dehydration of the borax. Between 500° and 800°F., the first liquid developed with the melting of the soda niter. Most of the reactions, however, took place from 800° to 1300°F. Soda niter and sodium silicofluoride were decomposed, and the antimony trioxide was oxidized. Above 1300°F., considerable glass was formed, and the enamel gradually became more uniform.
DEVELOPMENT OF OPACITY IN SUPEROPAQUE ENAMELS*
Authors: King Burnham W. , Andrews Andrew I.
Published: June 2006

Abstract

Using X‐ray and microscopic technique, a detailed examination was made of the effect of smelting time and temperature on the crystalline material causing opacity in typical superopaque antimony enamels. It was found that, although the crystalline antimony compound causing opacity in such enamels dissolved very slowly at smelting temperatures, there was a decided increase in the particle size of the opacifier particles as the time of smelting was increased. The presence of calcium was found to be beneficial in producing opacity.
PROPERTIES OF KAOLINITE AS A FUNCTION OF ITS PARTICLE SIZE*
Authors: Harman C. G. , Fraulini Felix
Published: June 2006

Abstract

This investigation was undertaken to ascertain whether or not certain properties of kaolinite are definite functions of particle size. The studies were carried out on carefully fractionated, single‐base kaolinite. The following properties of these fractions were measured: (a) base‐exchange capacity, (b) permeability, (c) heat of wetting, (d) thermal conduct, and (e) drying shrinkage. Base‐exchange capacity, heat of wetting, and drying shrinkage are not simple functions of the measured particle size of kaolinite because of the unpredictable physical characteristics and habits of the crystalline aggregates. The first three properties named are each linear functions of the other. These properties are independent of the physical groupings of the kaolinite crystals and therefore cannot be predicted from measured particle size except in the case of the finest fractions. Permeability is dependent both on apparent surface and true surface. Thermal‐analysis curves may be useful as a rough guide to clay properties.
USE OF ALUMINUM METAL IN THE CERAMIC INDUSTRY I, PROPERTIES OF REFRACTORIES PRODUCED WITH MIXTURES OF ALUMINUM, FIRE CLAY, AND GROG*
Authors: Schurecht H. G. , Sephton H. I.
Published: June 2006

Abstract

The addition of aluminum metal powder to fire‐clay‐grog mixtures greatly increased the strength of the fired brick as a result of an aluminothermic reaction between the metal and the silica in the clay and grog. Because the reaction takes place at 930°C. and causes the temperature to rise rapidly, it is necessary to heat these refractories only to 930°C. to produce hard, well‐fired brick. Such products have a high load‐carrying capacity at furnace temperatures and also a fair spalling resistance.
RELATION OF ELECTRICAL CONDUCTIVITY TO CHEMICAL COMPOSITION OF GLASS*
Authors: Badger A. E. , White J. F.
Published: June 2006

Abstract

The electrical conductivity of some glasses in the soda‐lime‐silica system was measured at 400 °C. with an apparatus which is described. The specific resistance at this temperature ranged from 0.06 to 5.0 × 105 ohms per cc. Measurements were made on other glasses containing equivalent amounts of various oxides incorporated in a parent soda‐lime‐silica glass. It was found that an increase in resistance was produced by additions of MnO, ZnO, B2O3, Fe2O3, BaO, PbO, TiO2, and K2O, the resistances increasing in this order. A decreased resistance was produced by Na2O, CaO, and Al2O3. Previously published data on the power factors of these glasses are reviewed.
ORTHOSILICATES OF THE ALKALINE EARTHS WITH SPECIAL REFERENCE TO THEIR USES IN THE REFRACTORY FIELD*
Authors: Seil Gilbert E. , Staff
Published: June 2006

Abstract

The orthosilicates of barium, strontium, calcium, and magnesium; mixed orthosilicates; and mixtures of the orthosilicates of the alkaline earth group are discussed. The effect of periclase on these types of orthosilicates at high temperatures is described. Tabulations are given of the physical properties and chemical compositions of the orthosilicates, including their chemical and mineralogical names, melting points, decomposition points, molecular weights, chemical compositions, crystalline systems, indices of refraction, optical signs, specific gravities, and specific volumes. New data and many illustrations are submitted to show the range of critical temperatures at which reactions take place and at which stabilization is effective. The order of formation is discussed in detail with special reference to the effect of the composition of the starting materials on the rate of reaction and on the critical temperatures at which the orthosilicates are formed.
PHOSPHATES IN CERAMIC WARE: III, PHOSPHORUS COMPOUNDS AS REDUCING AND FINING AGENTS IN GLASS*
Authors: Weyl Woldemar A. , Kreidl Norbbrt J.
Published: June 2006

Abstract

Phosphorus and phosphorus compounds, which are suitable fining and reducing agents for glasses to be melted under reducing conditions, have been applied in melting heat‐absorbing and copper ruby glasses. Ferrophosphorus conveniently introduces both iron and a reducing agent for heat‐absorbing glasses.

By balancing ferrophosphorus and red phosphorus or ferrophosphorus and sodium sulfate, it was possible to obtain glasses with the optimum FeO content under all melting conditions. The use of copper phosphide produced a superior copper ruby glass which strikes at a lower temperature and more rapidly.
ELECTROLYTES IN ACID‐RESISTING ENAMELS*
Authors: Petersen Fred A. , Hutchison Clark
Published: June 2006

Abstract

The effect of various electrolytes on the acid resistance, “set,” and defects of acid‐resisting enamels was studied. The defects encountered were scumming, pitting, and shorelining. It was found that (1) insufficient set caused scumming which was aggravated by aging the enamel; this defect may be eliminated by increasing the set of the enamel; (2) one of the enamels studied had a marked tendency to shoreline whenever a sulfate or an electrolyte containing the sulfate radical was used; and (3) the pitting tendency of one enamel was traced to the high soluble salt content of the mill liquor; this defect was eliminated by spraying the enamel at a high gravity or by applying the acid‐resisting enamel in a heavier coating. Some of this work has been continued in regular plant practice, and a discussion of this phase of the work is included.
NOTE ON MOISTURE EXPANSION OF CERAMIC WHITEWARE IN STORAGE AND IN SERVICE*
Authors: Geller R. F. , Creamer A. S.
Published: June 2006

Abstract

Eighteen samples of wall tile and 15 samples of tableware, which had been in service or in storage for periods of time ranging from 23 years to less than 1 year, were tested to determine how much moisture expansion had taken placc. Selected samples were also autoclaved, and the resultant moisture expansions were compared.
EFFECT OF RESIDUAL COLOR ON CONSUMER ACCEPTANCE OF PORCELAIN ENAMEL WHITES*
Authors: Iliff John W.
Published: June 2006

Abstract

Reflectometers are widely used to give a numerical rating for the comparative whiteness of porcelain enamels, but these instruments occasionally show values in disagreement with a careful visual comparison. To find the reason for this disagreement, a survey was made to determine the effect of residual color on the consumer rating of porcelain enamel whites. A series of 12 white plaques was made ranging from 67 to 75% in reflectance, from 478 to 485 m/x in dominant wave length, and from 1.6 to 5.6% in residual color. These specifications were determined from curves run on a Hardy G. E. recording spectrophotometer. The 12 plaques were submitted to 36 persons who arranged them in order of whiteness. The order of arrangement was compared statistically, and the whites were rated in their order of acceptance. Residual color was found to have an important effect on apparent whiteness, and of these typical porcelain enamel whites, those most highly colored (blue) were preferred.
USE OF A HIGH SERICITE PYROPHYLLITE IN VITREOUS BODIES*
Authors: Emrich Emerson W.
Published: June 2006

Abstract

A pyrophyllite containing approximately 15% of sericite is being produced at Hemp, North Carolina. When it is substituted in vitreous bodies for all of the flint or all of the flint and some feldspar, a marked increase in fired strength results, and the shrinkage and absorption properties are not affected by this substitution. The types of bodies studied include electrical porcelain, made by the dry and plastic processes, sanitary ware, vitreous floor tile, and hotel china ware.
EFFECT OF ZIRCOPAX ADDITIONS ON ABRASION RESISTANCE AND VARIOUS PROPERTIES OF SEVERAL GLAZES*
Authors: Commons C. H.
Published: June 2006

Abstract

A test method is described and the results of four series of experiments are given for the empirical evaluation of the effect of Zircopax in improving the resistance to abrasion of glazes. Simultaneous resistance to crazing and the effect on gloss, color, and opacity are noted.
USE OF LIQUID SURFACES AS STANDARDS OF SPECULAR GLOSS*
Authors: Moore Dwight G. , Hunter Richard S.
Published: June 2006

Abstract

It is possible to flow a film of any one of several liquids on the rough ground or sandblasted face of a black ceramic body and to use the surface of the film as a standard of specular gloss. The specular gloss of the film may be computed from the angle of reflection and the refractive index of the liquid by means of the Fresnel equation. The technique described in this paper was developed for use with the Hunter multipurpose reflectometer to avoid the inaccuracies of specular‐gloss measurements which result when the polished black glass surfaces heretofore employed as working standards become abraded in use.
STUDY OF THE EFFECT OF SOLUBLE SALTS PRESENT IN ENAMEL MILL LIQUORS*
Authors: Hurst T. L. , Andrews A. I.
Published: June 2006

Abstract

Studies were made of the solution of the frit during milling, the soluble salts derived from the frit were identified and studied, and some properties of the slips and mill liquors were investigated. The influence of some soluble salts present in cover‐coat enamels on enamel film strength is shown, and a theory regarding the mechanism of tearing has been developed. The function of some salts, particularly sodium hydroxide and sodium nitrite, in eliminating tearing was studied, and the manner in which these salts improve film strength is reported.
FUNDAMENTAL STUDY OF CLAY: II, MECHANISM OF DEFLOCCULATION IN THE CLAY‐WATER SYSTEM*
Authors: Johnson A. L. , Norton F. H.
Published: June 2006

Abstract

The effect of bases, basic salts, neutral salts, acid salts, and acids on the viscosity of clay slips cleaned as described in Part I of this study is shown. From these data, a fundamental theory of deflocculation is built up, based on the fact that deflocculation requires the presence of OH anions and monovalent cations. The influence on the viscosity of small traces of soluble salts or adsorbed ions, which are present in commercial clays, is discussed. It is also shown why sodium silicate or carbonate works more satisfactorily than sodium hydroxide in the deflocculation of commercial casting slips.
EMISSION SPECTROSCOPY AND ITS APPLICATION IN THE INVESTIGATION AND SOLUTION OF PROBLEMS IN CERAMICS*
Authors: Harrison H. C. , Bassett L. B.
Published: June 2006

Abstract

The fundamental theories of emission spectroscopy and the application of these theories to qualitative and quantitative spectrographic analysis are briefly reviewed. Some of the more widely used analytical methods and techniques are compared as to their relative value in the spectrographic analysis of ceramic raw materials and products. An inexpensive projection enlarger is described.
PHOSPHATES IN CERAMIC WARE: I, IN OPAL GLASSES*
Authors: Weyl Woldemar A.
Published: June 2006

Abstract

The theory has been advanced that the formation of apatite crystals is responsible for opacity in bone‐ash opals, which agrees with the experience of the writers in the formation of this group of minerals in magmatic melts. It also explains the characteristic behavior of bone‐ash glasses and provides means to avoid certain defects. The importance of phosphate opacification for opal glasses resistant to heat shock is briefly discussed.
CALCIUM OXIDE AS A SET‐UP AGENT FOR ACID‐RESISTING ENAMELS*
Authors: Sirovy George , Czolgos E. P.
Published: June 2006

Abstract

A study was made of the effect produced by calcium oxide in the set, color, luster, texture, and acid resistance of white and colored enamels.
RELATION OF COEFFICIENT OF EXPANSION TO IMPACT RESISTANCE OF PORCELAIN ENAMELS*
Authors: Fellows R. L. , Wheeler P. M.
Published: June 2006

Abstract

The tentative standard impact test procedure, adopted by the Porcelain Enamel Institute, was used to test and compare cylinders coated with several experimental and commercial enamels. The important facts noted were (1) the effect of cubic thermal expansion on the impact resistance, (2) the importance of the ground coat to the resistance of any one cover enamel, and (3) the wide variation between cover enamels in resistance to impact.
DEVELOPMENT OF OPACITY IN ZIRCONIA ENAMELS*
Authors: King Burnham W. , Andrews Andrew I.
Published: June 2006

Abstract

Opaque zirconia‐bearing enamels are divided into two general types, namely, those whose opacity is due (1) to the undissolved residue of the zirconia added in the raw batch and (2) to the crystallization of a zirconia compound during firing. These enamels are described and illustrated. The quantity, identity, and appearance of the materials causing opacity in representative samples of each group of enamels are given.
SOLUBILITY OF ZIRCONIA IN SODA‐BOROSILICATE GLASSES*
Authors: King Burnham W. , Andrews Andrew I.
Published: June 2006

Abstract

The solubility of zirconia at 1500° and at 2200°F. was determined for glasses containing Na2O, B2O3, Al2O3, and SiO2. The solubility at these same temperatures was also determined for glasses containing equal parts of boric oxide and silica and one or more of the following constituents in quantities of 10, 20, or 30%: Li2O, Na2O, K2O, MgO. CaO, SrO, BaO, ZnO, Al2O3, CaF2, and Na3AlF4.
PHOSPHATES IN CERAMIC WARE: IV, PHOSPHATE GLASSES*
Authors: Kreidl Norbert J. , Weyl Woldemar A.
Published: June 2006

Abstract

Phosphorus pentoxide, which was used first to improve the color of heavy flint glasses, was later recognized as a valuable constituent of optical glasses, and the excellent ultraviolet transmission and low softening points of phosphate glasses have been found recently. Glasses that have a high content of P2O5 have poor chemical resistivity, but this drawback is largely overcome by the addition of alumina. A possible picture of the constitution of phosphate glasses is presented, and the effect of alumina is explained. Some of the properties of the phosphate glasses have been investigated and correlated with their chemical composition and structure.
CONDITIONS ENCOUNTERED IN FILLING PRESSURE WARE*
Authors: Sharp John M.
Published: June 2006

Abstract

Many beverages contain dissolved COZ which is held in solution by pressure above atmospheric. To fill these products into pressure ware calls for mechanical systems which operate at pressures above atmospheric. The bottles are thus subjected to varying conditions of internal pressure during their filling. Because the ware is usually warmer than the product, there may also be some thermal effect. The action of the filling machine and the closure application may introduce some mechanical loading. The extent and timing of these conditions depend somewhat on the type of the filling apparatus, but the general limits may be stated to give some estimation of the service demands on the ware during this particular operation.
LOW‐TEMPERATURE VITREOUS BODIES*
Authors: Koenic C. J.
Published: June 2006

Abstract

The properties of a series of low‐temperature bodies predominately comprised of clays and nepheline syenite are described. These bodies have a higher alumina content than the usual typical pottery bodies because of the high alumina content of nepheline syenite and clays and also because flint is introduced only in small amounts.
CATALYTIC MULLITIZATION OF KAOLINITE BY METALLIC OXIDE*
Authors: PARMELEE C. W. , RODRIGUEZ ANTONIO R.
Published: June 2006

Abstract

The effect of the addition of various oxides on the mullitization of kaolinite was studied by chemical, microscopic, and X‐ray methods. A comparative study of the chemical and the X‐ray methods of mullite determination has shown that the chemical method (use of hydrofluoric acid) can yield only relative values. The use of X rays appears to give absolute results.

The oxides of zinc, lithium, magnesium, iron, manganese, and molybdenum were found to be good mullite builders; sodium, potassium, titanium, and stannic oxides were poor; and boric oxide and calcium oxide were fair accelerators.
STUDY OF GLAZE AND BODY INTERFACE*
Authors: PARMELEE C. W. , BUCKLES PAUL E.
Published: June 2006

Abstract

Lead‐containing raw glazes were applied on biscuit tile and fired at cones 02, 2, and 4. The glaze body interface was examined microscopically by preparing thin cross sections. The powdered glassy portion was also investigated.

Because the crystals separating at the interface were frequently too small for satisfactory study, a technique for promoting their growth was used. Anorthite, wollasto‐nite, gehlenite, undissolved quartz, tridymite, and cristobalite were observed.

The effects of altering the bases and the alumina and silica content of the glaze were studied, and the amount and the effect of the solution of the body were examined. The authors conclude that the interfacial layer is not necessarily intermediate in expansion conduct.
Stress‐Strain Characteristics of Plastic Clay Masses*
Authors: RUSSELL R. , HANKS C. F.
Published: June 2006

Abstract

The mechanical properties of plastic clay masses were investigated in terms of the fundamental concepts, stress and strain, and the interpretation involved the general terms, plasticity and workability. Compressive forces, applied by means of newly designed apparatus, were used throughout. A description is given of the apparatus as well as of the results for twelve different bodies, five individual clays, and five clayflint mixtures. In addition to composition, the factors investigated were the effect of water content, aging, rate of stress application, and cyclic loading. It was found that “moisture equivalent,” that is, the moisture content required for an arbitrarily selected equilibrium stress value, is a satisfactory parameter for the comparison of the plastic properties of clays and of similar body compositions. Aging increased the plasticity of ball clays progressively, whereas the china clays and a porcelain body became more workable. Increasing the rate of stress application caused progressive increases in the equilibrium stress. On the basis of the results obtained, a practical method of distinguishing between plasticity and workability is presented.
ELECTRIC FURNACE STUDY OF THE MgO‐SiO2 SYSTEM*
Authors: Ralston Robert R. , Faust George T.
Published: June 2006

Abstract

Fusions of compositions spaced at intervals throughout the magnesia‐silica system were prepared in an electric arc furnace. Potter's flint and precipitated magnesium carbonate were used as starting materials for one series of samples, and olivine, quartz sand, and magnesite were used as lower purity raw materials in a second series to simulate commercial conditions. Chemical, spectrographic, microscopic‐petrographic, density, and pyrometric cone equivalent (P.C.E.) determinations were made on typical specimens selected from each melt. Periclase, forsterite, and clinoenstatite crystallized in strict agreement with the phase diagram, and the phenomenon of immiscible silicate phases was observed in high silica compositions. No new compounds, however, were seen. The possibility of beneficiating olivine for refractory service by electric furnacing was also investigated.
REFRACTORIES SERVICE CONDITIONS IN THE BLAST FURNACE*
Authors: Kraner Hobart M.
Published: June 2006

Abstract

An analysis of “how a blast‐furnace lining wears out” is presented. The conclusions drawn are the result of critical studies on three furnaces as their linings were being removed for relining. Scab and scab‐refractory interface samples were taken at 3‐ft. intervals. These were analyzed and studied petrographically. Alkali attack and carbon disintegration are concluded to be the most serious causes of lining wear and deterioration in the stack, whereas insufficient refractoriness and high porosity are concluded to be the sources of trouble in the hearth.
INFLUENCE OF FLUXES OF SPODUMENE AND FELDSPAR MIXTURES ON PROPERTIES OF CHINAWARE BODIES*
Authors: Schurecht H. G. , Shapiro J. K. , Zabawsky Z.
Published: June 2006

Abstract

The most fusible spodumene‐feldspar mixture used in these studies was composed of 30% of spodumene, 10% of potash feldspar, and 60% of soda feldspar. In semi‐vitreous bodies and vitreous hotel chinaware bodies, however, the most effective fluxes were made up of 30 to 40% of spodumene, 40 to 60% of potash feldspar, and 10 to 20% of soda feldspar. Such fluxes lowered the maturing temperature of these bodies and improved their strength at lower temperatures. When they were fired at cones 6 to 9, their resistance to impact was equal to or higher than that of the feldspar bodies.
FUNDAMENTAL STUDY OF CLAY: III, CASTING AS A BASE‐EXCHANGE PHENOMENON*
Authors: Johnson A. L. , Norton F. H.
Published: June 2006

Abstract

Specimens of commercial casting slip were cast in plaster molds, porous bisque molds, and porous bisque molds treated with calcium and aluminum chloride. A qualitative determination of the ion serving in the exchange position is possible by the evaluation of the yield value of the cast specimen. The results on a series of tests indicate that casting clayware may be carried out by one of two processes, namely, mechanical water removal by the porous mold or by an exchange reaction between the ions of the slip and those of the mold; combinations of both processes may also occur. A detailed description of both methods, including practical applications, is given.
EFFECT OF STEAM AND HOT WATER WITH SODA ASH AND A WETTING AGENT ON PROPERTIES OF CLAY*
Authors: Schurecht H. G. , Mcmahon J. F. , Lampman C. M.
Published: June 2006

Abstract

The use of combined treatments was found to Ix more efficient in improving the properties of clays than individual treatments, and the best results were obtained when the clay was pugged with steam and hot water with an addition of 0.2% of soda ash. This process lowered the water of plasticity 26%, the drying shrinkage 58%, arid the absorption 46.5%. The dry and fired strengths were increased 123% and 144%, respectively.
EXPANSION, CONTRACTION, AND STRENGTH CHANGES OF SOME CLAYS DURING FIRING*
Authors: Hursh R. K. , Blanchard M. K.
Published: June 2006

Abstract

The objective of these experiments was to determine (1) the linear changes in expansion arid shrinkage during firing, (2) the effect of compressive loading on these changes, and (3) the variations in strength at furnace temperatures during the firing of some typical shales and fire clays used for the manufacture of structural clay product.
RELATION BETWEEN CHEMICAL COMPOSITION AND DIELECTRIC PROPERTIES OF CERAMIC MATERIALS WITH LOW DIELECTRIC LOSSES*
Authors: Rigterink M. D. , Grisdale R. O. , Morgan S. O.
Published: June 2006

Abstract

A number of steatite ceramics were prepared under carefully controlled conditions, and their dielectric losses and direct‐current resistances were measured at elevated temperatures. It was found that variations of the ratio of talc to kaolin within certain limits had little effect on the dielectric properties. These properties, however, were changed to a considerable extent by varying the amounts, proportions, and kinds of alkaline earth oxides added as fluxes. The data indicate also that the conditions in a ceramic favorable to a high specific resistance are not necessarily those favorable to a low dielectric loss.
NOTES ON THE CONSTITUTION OF STEATITE*
Authors: Thurnauer Hans , Rodriguez A. R.
Published: June 2006

Abstract

A review of the literature is given. A number of steatite bodies, which were given a varying number of firings, were investigated by autoclaving and determining the water absorption in conjunction with microscopic and X‐ray methods.
APPARATUS FOR MEASURING THERMAL CONDUCTIVITY OF REFRACTORIES*
Authors: Norton C. L.
Published: June 2006

Abstract

An apparatus for measuring the thermal conductivity of refractories, is described in detail, and results are shown for several types of insulating refractories. Comparisons are madc from data which were obtained on a low‐temperature plate tester, and the effect of several variables on measured heat flow are discussed.
CONTROL TESTING FOR CONSISTENCY OF REFRACTORY MORTARS*
Authors: Petrie Earl C. , Kocher D. W.
Published: June 2006

Abstract

Various methods of determining the consistency of mortars are discussed, and data are included to show the test results obtained on different instruments. A description is given of a modified Vicat needle which may be used for the control of consistency during the manufacture of wet‐type, cold‐setting mortars.
RESISTANCE OF ENAMELS TO THERMAL SHOCK*
Authors: Howe E. E. , Bolin E. P.
Published: June 2006

Abstract

Thermal‐shock resistance tests were made on enamels of varying thermal expansions applied on test pans. Increased weight of application and high expansion of the cover coat decreased the thermal‐shock resistance, whereas high expansion of the ground coat increased the resistance.
EFFECT OF BARIUM OXIDE AND ZINC OXIDE ON PROPERTIES OF SODA‐DOLOMITE LIME‐SILICA GLASS*
Authors:   Contribution of the General Research Laboratory Owens‐Illinois Glass Company
Published: June 2006

To a base glass containing 14% of sodium oxide, 12% of dolomite lime, and 74% of silica, barium oxide and zinc oxide, respectively, were systematically substituted for (a) Na2O, (b) CaO.MgO, and (c) SiO2 in amounts of 1, 3, and 5%. The effects of these substitutions on such physical properties as liquidus temperature, viscosity, deformation temperature, density, fiber softening point, coefficient of expansion, and the resistance of the glasses to dilute acid and distilled water are presented.
ANALYSIS OF GASES DISSOLVED IN GLASS AND GASES PRESENT IN SEEDS*
Authors: SHADDUCK HUGH A. , VAN ZEB ARTHUR
Published: June 2006

A method of analysis for gases dissolved in glass has been developed which gives more reproducible results than those previously reported. The problem of the volatilization of alkali from the sample during the course of analysis appears to have been satisfactorily solved through the use of an auxiliary furnace. A number of commercial glasses have been analyzed for dissolved gases. Water vapor, sulfur dioxide, and oxygen are the principal gases found in flint glass. Water vapor seems to be the principal constituent of the gases found in amber glass.

A method for the analysis of gases present in seeds in glass has been developed which gives fairly satisfactory quantitative results on samples containing more than 1 cu. mm. of gas. The results obtained on samples containing less than 1 cu. mm. of gas are qualitative only. The procedure consists (1) in the determination of the temperatures at which gases present in the seeds undergo a change of state and (2) in the microchemical analysis of these same gases. Seeds have been found that contained entrapped air, sulfur dioxide, and also carbon dioxide. Some seeds, especially those in amber glass, appear to be vacuum seeds, and these frequently contain a deposit on the inside which has been identified as a sulfite or a sulfate.
ZIRCONIA‐MAGNESIA SPINEL SYSTEM*
Authors: MATHER R. F.
Published: June 2006

An investigation of the zirconia‐spinel system, ZrO2‐MgAl2O4, was made, using the criteria of thermal expansion, density, and microstructure. The samples were fired for six hours at 1650°C. No stable compounds or solid solutions were formed. An unstable solid solution, possibly based on a zirconia‐spinel compound, was formed, however, apparently extending from pure spinel to 30 mol. % of zirconia. The solid solution gradually decomposed on repeated heating to 1300°C., and the system ultimately behaved as a series of simple aggregates of zirconia and spinel. The zirconia transformation took place at 1110°C. throughont the system. On cooling, the transformation temperature was lowered by the presence of spinel from 990°C. for the zirconia‐rich samples to fi30°C. at the spinel end of the system.
USE OF THE PHOTRONIC CELL AND SPECTROPHOTOMETER FOR MEASURING TRANSLUCENCY OF WHITEWARE*
Authors: Arrance Frank C.
Published: June 2006

Abstract

A method has been developed for measuring the translucency of whiteware by means of the photronic cell, and a modified formula has been derived to express the relationship between translucency and thickness of ware. Bodies containing mixtures of feldspar and lepidolite were translucent over a greater range of temperatures than those which contained feldspar or lepidolite alone, although the translucency of the feldspar bodies was greater than that of the lepidolite bodies having equivalent absorptions. The spec‐trophotometer gives a more complete record of the translucency of porcelain because it may be used to measure the transmittance of ultraviolet, visible, and infrared light.
PORCELAIN ENAMEL AS A PROTECTIVE COATING FOR HOT‐WATER TANKS*
Authors: Goetchius D. R.
Published: June 2006

Abstract

The suitability of zinc and porcelain enamel as protective surfaces for water‐storage tanks is discussed. The test methods are given in detail as well as the results of the simulated service tests.
PROPERTIES OF WARE VERSUS THERMAL HISTORY: I, TESTS ON VITREOUS CHINA BODIES AND WARE *
Authors: Koenic J. H.
Published: June 2006

Abstract

The properties of ware, which were given different thermal treatments, have been compared. The tests include shrinkage, flexural strength, elasticity, thermal expansion, moisture expansion, microstructure, glaze stress, and glaze microhardness. The variations in these properties occurred as a result of differences in (1) supposedly similar firings, (2) the uniformity of the kiln from end to end, (3) the same firing in the cross section of the kiln caused by uneven heat distribution, (4) the rates of firing to the same cone deformation, and (5) repeated firings.
PROPERTIES OF WARE VERSUS THERMAL HISTORY: II, TESTS ON SEMIVITREOUS CHINA BODIES AND WARE *
Authors: Koenic J. H.
Published: June 2006

Abstract

The properties of semivitreous bodies and ware, which were given different thermal treatments, are compared. The tests include flexural strength, shrinkage, absorption, elasticity, moisture, and thermal expansion. The resistance to crazing vs. the bisque thermal history is correlated with (1) the moisture and thermal expansion of the two bodies studied, (2) actual crazing tests on ware made from these bodies, and (3) glaze fit tests. The variation in glaze texture, hardness, and stress condition for different glostfiring treatment was studied.
THE COMPOUND MERWINITE (3CaO.MgO.2SiO2) AND ITS STABILITY RELATIONS WITHIN THE SYSTEM CaO‐MgO‐SiO2 (PRELIMINARY REPORT)*
Authors: Osborn E. F.
Published: June 2006

Abstract

Preliminary investigations on compositions between Ca2SiO4 and akermanite (Ca2Mg‐Si2C7), between merwinite (Ca3Mg(SiO4)2) and akermanite, and between merwinite and monticellite (CaMgSiO4 indicate that a field of merwinite appears on the liquidus surface of the system CaO‐MgO‐SiO2 and that merwinite melts incongruently at 1575 °C. to Ca2SiO4, MgO, and liquid.
MEASUREMENT OF THE THERMAL CONDUCTIVITY OF FIRELAY REFRACTORIES*
Authors: Patton T. C. , Norton C. L.
Published: June 2006

Abstract

Thermal conductivity determinations have been made on superduty fire‐clay, silica, and kaolin refractories, using the Globar‐heated, water calorimeter apparatus previously described. The arrangement, which is satisfactory for insulating firebrick, gives considerable error when firebrick samples are tested. Results obtained by different arrangements of the guard samples and heating elements are shown as well as a final arrangement which gives a satisfactory condition of parallel heat flow.
MOTTLED SILICA BRICK, FACTS, FANCIES, AND FALLACIES*
Authors: Harvey FRED A. , Thompson Clyde L.
Published: June 2006

Abstract

The extent of coloration is dependent on the amount of lime and alumina and on the thermal history. The coloring agent is usually iron oxide which is present in small amounts. Color is dependent on the grind and on the mixing, drying, and burning procedures. The color can be cleared up or accentuated by controlled laboratory reheating at known temperatures, for definite time intervals. The mottling does not appear unless the brick are well burned. The spots, moreover, have no harmful effect. The literature on this subject is reviewed.
POSSIBLE USE OF FERRUGINOUS TALCS IN STEATITE DIELECTRICS*
Authors: Kane Laurence E. , Ueltz Herbert G.
Published: June 2006

Abstract

Several iron‐bearing tales were fired alone and in body form and were measured for shrinkage and absorption. Their colors were also noted. Electrical measurements of dielectric constant and loss characteristics were made on the bodies and compared with white‐firing tales. The effect of small additions of Fe2O3 on a white‐firing talc is also described.
EQUILIBRIUM RELATIONSHIPS ON THE LIQUIDUS SURFACE IN PART OF THE MnO‐Al2O3‐SiO2 SYSTEM*
Authors: Snow R. B.
Published: June 2006

Abstract

The minerals found to have a stability range on the liquidus surface in the system MnO‐Al2O3‐SiO2 are cristobalite and tridymite, SiO2; mullite, 3Al2O3. 2SiO2; corundum, Al2O3; rhodonite, MnO.SiO2; tephroite, 2MnO.SiO2; galaxite, MnO.Al2O3; spessartite, 3MnO.Al2O3.3SiO2; and a new compound, 2MnO.2Al2O3.5SiO2. The quintuple points and boundary lines found in that part of the MnO.Al2O3.SiO2 system bounded by the systems 3MnO.Al2O3.3SiO2‐SiO2, 3MnO.Al2O3.3SiO2‐Al2O3, and Al2O3‐SiO2have been determined. Quintuple points and boundary lines involving the area inclosed by the systems 2MnO . SiO2‐3MnO . Al2O3 . 3SiO2, 3MnO . Al2O3 . 3SiO2‐SiO2, and 2MnO.‐SiO2‐SiO2 are indicated. Isotherms and isofracts (lines of equal refractive index) are given for the portion of the system investigated.

X‐ray data show that crystals of the compound 3MnO.Al2O3.3SiO2 have the same structure as the garnet mineral spessartite (manganese garnet). The compound 2MnO. 2Al2O3 . 5SiO2, which is shown by X‐ray data to have a basic structure similar to cordierite, 2MgO.2Al2O3.5SiO2, seldom crystallizes from the glass, but a third substance which has a high extinction angle crystallizes readily from the reheated glass. These high extinction angle crystals are replaced by 2MnO .2Al2O3.5SiO2 when a proper heating cycle is employed, and they are not found again until the product is melted and crystallization is repeated.
EXPERIMENTAL STUDIES OF THE TEMPERATURE GRADIENTS IN GLASSES OF VARIOUS COLORS*
Authors: Holscher H. H. , Rough R. R. , Plummer J. H.
Published: June 2006

Abstract

Laboratory gradients are presented for glasses of different colors and coloring agents when heated at the surface to a temperature of 2615°F. The gradients in commercial tanks are related to these laboratory‐tank experiments. Ferrous iron and chromic oxide yield the largest gradients, whereas selenium, cerium, and very small amounts of cobalt give small gradients. Ferric iron gives a largc gradient and manganese a relatively low gradient. Iron sulfur ambers are intermediate. Visible color or color intensity is no indication of the temperature gradients.
STUDY OF PHOTOLUMINESCENCE IN GLASS*
Authors: Rodriguez A. R. , Parmelee C. W. , Badger A. E.
Published: June 2006

Abstract

The influence of composition and temperature on the fluorescence of glasses containing uranium and glasses containing cuprous oxide and stannous oxide was investigated. Secondary cations reduce the fluorescence of uranium in the glasses studied, depending to a certain extent on the electrostatic conditions they produce in the glass structure. The intensity of fluorescence as well as the structure of the spectrum diminishes in the order of phosphate, silicate, and borate glasses of equivalent compositions, which shows that fluorescence is favored by increase of oxygen in the glass structure without increasing the interfering secondary cations. Raising the temperature greatly diminishes the intensity of the fluorescence as well as the structure of the spectrum of glasses containing uranium. The fluorescence of the glasses containing cuprous oxide and stannous oxide as activators seems to be favored by increase in lime and increase in silica. These glasses possess appreciable phosphorescence, which appears to be enhanced by increase in silica and decrease in lime. A peculiar property of this type of luminescent glass is a maximum which it exhibits in its fluorescence‐temperature relation‐ship. There are indications that electrons are set free from the excited centers (copper atoms or small groups of copper atoms), which wander about in the glass structure.
SOLUBLE SULFATE CONTENT OF POTTERY BODIES DURING PREPARATION*
Authors: Shell H. R. , Cortelyou W. P.
Published: June 2006

Abstract

A method of analysis has been developed that gives consistent results for soluble sulfate and total soluble salts in ceramic raw materials and bodies. Values for sulfate on a dry‐weight basis ranged from 0.01 to 0.28% with ball clays, from 0.002 to 0.015% with china clays, and from 0.000 to 0.007% with miscellaneous raw materials. Bentonites were relatively high in sulfate, a Wyoming bentonite showing the highest value, 0.194%.

The distribution of sulfate in the slip, cake, and press water was determined for eighteen ceramic bodies. An increase in the water‐clay ratio in slips was found to increase the recoverable soluble sulfate (percentage dry basis). In experiments on repeated cycles of cake to slip to filter pressing, soluble sulfate continued to be released, but the bulk of the sulfate was obtained in the first pressing. Quantitative results are given on the effectiveness of barium carbonate as a precipitating reagent for sulfate in slips.

Aging from six months to one year was found to have little effect on the soluble sulfate in stored samples of slips, cakes, and press waters. Dry storage, however, doubled the soluble sulfate content of a freshly mined ball clay within six months, evidently by oxidation of sulfur compounds.
THEORETICAL ASPECTS OF CHEMICAL ATTACK OF GLASSES BY WATER*
Authors: Lyle A. K.
Published: June 2006

Abstract

The effects of time and temperature on the chemical attack of glasses by water are represented by the equation; α log N= log θ ‐ b/T+c; N= attack; θ= time; T = absolute temperature, °K; a, b, and c, are experimentally determined constants. The constant, b, of the equation is independent of the glass composition and of the size and shape of the sample tested and has a value of 5080 for tests of ordinary glass containers. As a time‐temperature function, the equation may be written as log θ=b/T ‐ C, in which form it is useful for estimating the storage or service conditions equivalent to art accelerated test or for calculating the conditions of alternate tests. Data from the literature are used in demonstrating the accuracy and usefulness of the equation.
SUBSTITUTION OF TOPAZ, DOMESTIC KYANITE, AND SYNTHETIC MULLITE‐CORUNDUM FOR INDIA KYANITE, I–III*
Authors: McVay T. N. , Wilson† Hewitt
Published: June 2006

Abstract

This report on the utilization of domestic materials as replacements for India kyanite has been divided into four parts, namely, (I) kyanite and other high‐grade refractories, (II) effect of heat on kyanite and topaz, and (III) load resistance of refractories at elevated temperatures; (IV) will be published later.
STUDY OF DIFFUSION IN GLASS*
Authors: Pask J. A. , Parmelbe C. W.
Published: June 2006

Abstract

An introductory study was made of diffusion into glass from salts, with silver nitrate as the chief source of diffusing particles. The optimum test conditions were a temperature of 900°C. and a test time of 108 hours. The results noted were (1) effect of time, (2) effect of temperature on the distance of diffusion, (3) variation of silver concentrations in the glass with the distance of diffusion, and (4) a check of Fick's law of diffusion. The concentration gradient of silver from a diffusing interface was determined with the use of a spectrograph and corresponding particle sizes with an ultramicroscope. In addition to the silver nitrate, a number of other salts were tested at several temperatures. The development of Liesegang rings was noted in some of the samples. The nature of diffusion in glass was deduced from the results.
STRUCTURAL HOMOGENEITY OF GLASS*
Authors: Winter Aniuta
Published: June 2006

Abstract

A study of the mechanical strains present in a sample of glass does not insure a prediction of the future behavior of this glass. There is no simple relation between such strains and the physicochemical state of the glass. Most of these states, in fact, probably may be obtained with or without birefringence, depending on the thermal treatment to which the glass was submitted. If the glass is not in the equilibrium condition for the temperature at which it is being used, it will transform spontaneously toward that equilibrium, The birth and evolution of strains depend on these physicochemical unbalances as well as on other characteristics of the glass. Only the study of the physico‐chemical state can give reliable indications of the behavior of glass in practical use.