摘要:

AbstractMovement of montmorillonite, nontronite, kaolinite, halloysite, dickite, gibbsite, and diaspore within clays after they were first formed is indicated by the relations reported in this paper. Migration of these minerals takes place rarely by transfer of their constituents as true solutions but generally as colloidal suspensions whose formation and movement are favored by conditions of good drainage and the presence of dispersing agents. This migration increases the complexity of the clays affected by it and accounts for some of the variations in the composition of a single body of clay met by the clay producer.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1945.tb14491.x

出版商:Blackwell Publishing Ltd    

年代:1945

数据来源: WILEY

摘要:

AbstractExamination of stove tops that had crazed in service show two types of crazing. One is in the form of a network of cracks which may be attributed to thermal shock, while the other is in the form of parallel lines and occurs in the normal use of the stove without any particular abuse. In studying the latter type of failure, localized heating of the stove top causes a cross‐bend failure of the enamel due to flexing from the heat, and the higher the temperature the less is the amount of deflection required to cause failure. The temperature necessary for this condition is lower than 550°F. Sample plates subjected to various tests afforded a means of studying the different variables that produce crazing in stove tops.From these tests, the following observations are made: (1) Stove tops that have tensile strains in the enamel due to fabrication or assembly are likely to craze in the areas of these stresses if they are heated; (2) the lower the coefficient of expansion of the cover‐coat enamel, the less likely is the enamel to craze; (3) the lighter the weight of application of cover coat, the greater is the resistance to crazing; (4) the heavier the gauge of metal the greater is the resistance to crazing; and (5) heating the enamel over a long period of time tends to induce cra

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1945.tb14492.x

出版商:Blackwell Publishing Ltd    

年代:1945

数据来源: WILEY

摘要:

AbstractA method is described for measuring the fining time of glass, and a formula is given for using the data obtained to estimate the tonnage‐temperature schedules of continuous tank furnaces. Measurement of fining time at two and preferably three temperatures, in the range 1400° to 1500°C., is required to establish the fining characteristics of a glass. Data from fining‐time measurements of four glasses show that fining is largely independent of the viscosity and probably also of the surface tension of glass.The use of fining‐time measurements in accounting for differences in the melting efficiencies of tank furnaces and the value of systematic studies, involving fining agents and variations in composition, are su

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1945.tb14493.x

出版商:Blackwell Publishing Ltd    

年代:1945

数据来源: WILEY

摘要:

AbstractA statistical comparison has been made of 13 sets of measurements of optical path difference, taken over a seven‐year period, on 24 samples of the standardized disks distributed in 1938 to the manufacturers of glass containers. These data show that the original optical retardation of about 22.8 millimicrons has not changed by more than =1.3%, equivalent to =0.30 millimicron or =0.10° on the scale of the measuring instrument.Five tests were made in 1938, five in 1945, and three between. The standard deviation of the combined errors for each of the 13 averages of 24 measurements is =0.0338° and is composed of an accidental error of observation of =0.005° and an error of adjustment of the instrument of =0.0333°. The range of =1.3%, or =0.10°, beyond which the disks could not have changed over seven years, represents the 3‐sigma probability limit of combined errors.While this possible change of =1.3% would be insignificant in relation to the utility of the standardized disks, it represents a possible experimental error too great to permit broad conclusions concerning the ultimate stability of birefringence in strain

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1945.tb14494.x

出版商:Blackwell Publishing Ltd    

年代:1945

数据来源: WILEY

摘要:

AbstractNonmathematical considerations indicate that residual annealing stresses in glass are permanent although Ghering and Green do not draw this positive conclusion from their analysis of measurements over a seven‐year perio

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1945.tb14495.x

出版商:Blackwell Publishing Ltd    

年代:1945

数据来源: WILEY