摘要:

ABSTRACTCommercial glasses of the soda‐lime‐silica types do not consist solely of these three oxides, but in addition contain significant amounts of other constituents which arc introduced incidentally as impurities or deliberately for some beneficial influence. Such minor additions may have either a favorable or unfavorable influence on the tendency of the glass to devitrify, and an investigation into the effect of such minor components is desirable. Previous results with MgO and with A12O3have shown that a systematic study of a four‐component system is necessary to the understanding of its devitrification relations, and that arbitrary and fragmentary excursions into such a system give little insight into the general effect of the minor constituent and may be misinterpreted to erroneous conclusions as to the effect of this constituent on glasses of slightly different composition. Accordingly, in taking up the study of the effect of B2O3on the devitrification of the soda‐lime‐silica glasses, it was added to 21 glasses in and near the field of devitrite, Na2O·3CaO·6SiO2, in the ternary system, Na2O–CaO‐SiO2, in amounts up to about 5%. In all cases the liquidus temperature was lowered, and the tendency toward devitrification reduced. Both of these effects are desirable and add to the thermal stability of the glass. With glasses containing 10% CaO, initially in the field of tridymite or so near to it that a small addition of B203 brings the resulting glass into the tridymite field, this initial lowering is replaced by an increase in the liquidus temperature which passed through a maximum at from 4 to 6% B2O3. With all other glasses the lowering continues, and the rate of decrease is greatest with glasses originally in the field of Na2O·2CaO·3SiO2. An exploration of the quaternary system showed that no new compounds are formed in any mixture that can be obtained by adding B203 in amounts up to 50% to any mixture in or near the devitrite field. It also indicated the probability that a narrow band of immiscible liquids is formed, extending across the ternary system, CaO‐B2O3–SiO2, and including the mineral danburite, CaO·B2O·2SiO2, but probably not extending far into the quaternary system. The fields of wollastonite and of Na2O·2CaO·3SiO2were found to sweep out regions in the quaternary system extending over the square, Na2O·SiO2‐Na2O·B2O3‐CaO‐B2O3‐CaOSO2, and the field of Na2O·CaO·SiO2was found to extend over the middle of this square, and is probably adjacent to the fields of wollastonite and of Na2O· 2CaO·3SiO2. A compound is formed between Na2O·B2O3and CaO·B2O3. There is included a general survey of the literature relative to the

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1932.tb13959.x

出版商:Blackwell Publishing Ltd    

年代:1932

数据来源: WILEY

摘要:

ABSTRACTSheet‐steel enamels with varying amounts of cobalt, nickel, and manganese oxides were applied to cast iron. Their impact resistance was determined and a study of contact zones was mad

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1932.tb13960.x

出版商:Blackwell Publishing Ltd    

年代:1932

数据来源: WILEY

摘要:

ABSTRACTAnalyses were made of the material from the steel‐enamel contact zones of a series of enamels containing varying amounts of cobalt oxide. The impact resistance of these enamels was determined and a method for determining cobalt in enamels was develope

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1932.tb13961.x

出版商:Blackwell Publishing Ltd    

年代:1932

数据来源: WILEY

摘要:

ABSTRACTPieces of enamel were removed from contact zones and studied microscopically and with the X‐ray and metallographic microscope. A new technique for enamel study is suggeste

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1932.tb13962.x

出版商:Blackwell Publishing Ltd    

年代:1932

数据来源: WILEY

摘要:

ABSTRACTThis paper reports the results of a continuation and confirmation of Schwartz‐walder's wor

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1932.tb13963.x

出版商:Blackwell Publishing Ltd    

年代:1932

数据来源: WILEY

摘要:

ABSTRACTThe corrective effect of a soft enamel in copperheading is shown. Pearlitc. in the Fishscaling is caused by gas from the steel. steel is the basic cause of copperheading.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1932.tb13964.x

出版商:Blackwell Publishing Ltd    

年代:1932

数据来源: WILEY

摘要:

ABSTRACTThe occurrence, manufacture, and utilization of commercial butane is discussed. It is compared with other gaseous fuels in respect to (1) theoretical thermal efficiency, (2) volume of products of combustion, (3) theoretical flame temperature, (4) rate of flame propagation, (5) specific gravity, (6) resulting quality of ware, and (7) cost per unit of available heat. Results of actual tests on an open‐fire McDougal tunnel kiln using butane, in which these properties were considered, indicated that it is possible to substitute butane for coal‐gas fuel with only minor adjustments in kiln, burner, or accessory equipm

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1932.tb13965.x

出版商:Blackwell Publishing Ltd    

年代:1932

数据来源: WILEY

摘要:

ABSTRACTFuel gas may be burned as rapidly as possible by thorough premixing or as slowly as possible by the elimination of all effects tending to accelerate the mixture of air and gas. In the latter case, combustion occurs through molecular interdiffusion, hence, “diffusion combustion.”The diffusion flame has unique properties as a heat radiator, not necessarily associated with visible luminosity, which are attained by liberating the maximum quantity of free suspended carbon from a given volume of gas. These properties make possible greater uniformity of heat distribution and lower temperature gradients than are possible with any other type of combustion.The combustion requirements of the ideal glass tank, which include maximum utilization of the melting surface, heat penetration into the bath, and convection current control, are well met by diffusion combust

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1932.tb13966.x

出版商:Blackwell Publishing Ltd    

年代:1932

数据来源: WILEY

摘要:

ABSTRACTThe object of this study was to find the shape of a dome having no circumferential stresses. To find such a surface of revolution, the calculus of variations was employed, and a differential equation set up whose solution would be a curve which, when revolved about the vertical axis, would give this surface. This differential equation was found to be unsolvable except by graphical methods. A graphical solution was obtained using an integrating machine. The vertical cross‐section of this surface is compared with well‐known curves. It is found that spherical domes with small heights lie inside the surface in question, and are therefore stable, while spherical domes which approach a hemisphere lie outside this surface at certain points, and are unstable. These conclusions are in accordance with the physical facts. Tables containing all the data relative to this derived surface are given. The relation between the resultant stress at the base and the height is shown graphically. The radial component of stress is found to approach infinity for a very flat dome, and to approach zero for a high dome. The value of this dome lies in the fact that stability of any curve may be determined by comparison with it. Any curve which lies outside this limiting curve at any point will give an unstable dome. It also makes it possible to find the surface having a minimum resultant stress for any given base diameter or any given hei

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1932.tb13967.x

出版商:Blackwell Publishing Ltd    

年代:1932

数据来源: WILEY