An investigation of the constitution of the mercury-tin system was made by a combination of three techniques: differential thermal analysis; diffusion and chemical analysis; and X-ray diffraction. The mercury-silver-tin system is of interest because it is the basis of dental amalgam, the most important single dental restorative material. Information as to the constitution of these alloys is incomplete for both the ternary system and the mercury-tin binary system. This study was devoted to the investigation of the mercury-tin system as a prerequisite to a study of the ternary alloys. The results obtained by the various methods are not in complete agreement. They indicate that the system is more complex than previously reported. Additional evidence for the beta phase as reported by Prytherich was found but the composition limits and eutectoid temperature remain to be confirmed. The gamma phase composition limits were found to differ from earlier values. Corroborative data for Gayler’s delta phase and possible evidence for a previously unreported epsilon phase have been found by X-ray diffraction. The thermal analysis results indicate the possible existence of additional phases unconfirmed by other methods. A modified mercury-tin phase diagram based upon these findings is proposed.
{"title":"An Investigation of the Constitution of the Mercury-Tin System1","authors":"D. F. Taylor, C. L. Burns","doi":"10.6028/jres.067A.008","DOIUrl":"https://doi.org/10.6028/jres.067A.008","url":null,"abstract":"An investigation of the constitution of the mercury-tin system was made by a combination of three techniques: differential thermal analysis; diffusion and chemical analysis; and X-ray diffraction. The mercury-silver-tin system is of interest because it is the basis of dental amalgam, the most important single dental restorative material. Information as to the constitution of these alloys is incomplete for both the ternary system and the mercury-tin binary system. This study was devoted to the investigation of the mercury-tin system as a prerequisite to a study of the ternary alloys. The results obtained by the various methods are not in complete agreement. They indicate that the system is more complex than previously reported. Additional evidence for the beta phase as reported by Prytherich was found but the composition limits and eutectoid temperature remain to be confirmed. The gamma phase composition limits were found to differ from earlier values. Corroborative data for Gayler’s delta phase and possible evidence for a previously unreported epsilon phase have been found by X-ray diffraction. The thermal analysis results indicate the possible existence of additional phases unconfirmed by other methods. A modified mercury-tin phase diagram based upon these findings is proposed.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"94 1","pages":"55 - 70"},"PeriodicalIF":0.0,"publicationDate":"1963-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73370066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A test mixture consisting of 2,3-dimethylpentane and 2-methylhexane was prepared and its relative volatility determined by a fractional distillation method. This test mixture was compared, experimentally and theoretically, with another test mixture commonly used for evaluating highly efficient fractionating columns.
{"title":"2,3-Dimethylpentane and 2-Methylhexane as a Test Mixture for Evaluating Highly Efficient Fractionating Columns*","authors":"E. C. Kuehner","doi":"10.6028/jres.067A.002","DOIUrl":"https://doi.org/10.6028/jres.067A.002","url":null,"abstract":"A test mixture consisting of 2,3-dimethylpentane and 2-methylhexane was prepared and its relative volatility determined by a fractional distillation method. This test mixture was compared, experimentally and theoretically, with another test mixture commonly used for evaluating highly efficient fractionating columns.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"1 1","pages":"15 - 18"},"PeriodicalIF":0.0,"publicationDate":"1963-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83279068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The six elastic constants (and six elastic compliances) of rutile were determined in the kilocycle per second frequency range by a resonance method. The standard deviations range from 0.2 percent for s11 to 4.3 percent for s13.
{"title":"Elastic Constants of Rutile (TiO2)","authors":"J. B. Wachtman, W. E. Tefft, D. G. Lam","doi":"10.6028/jres.066A.047","DOIUrl":"https://doi.org/10.6028/jres.066A.047","url":null,"abstract":"The six elastic constants (and six elastic compliances) of rutile were determined in the kilocycle per second frequency range by a resonance method. The standard deviations range from 0.2 percent for s11 to 4.3 percent for s13.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"35 1","pages":"465 - 471"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81500930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The relative ultraviolet stability of four chemically modified polycaprolactam (Nylon-6) systems is discussed: methylmethoxylated fibers and three other fibers having methylene, disulfide, and alkylene sulfide crosslinks, respectively. The ultraviolet degradation of these systems is studied by means of a sensitive analytical technique in which the methylene (—CH2—) groups remaining in the chemically modified fibers after irradiation are converted to formaldehyde; the liberated formaldehyde is then reacted with chromotropic acid to give a colored product, the absorbancy of which can be determined spectrophotometrically. The results indicate that the data can be expressed by first order rate equations from which the rate constants may be calculated. The scission of the crosslinks is accompanied by a decrease in the internal orientation of the networks as shown by X-ray diffraction photographs.
{"title":"Ultraviolet Stability of Crosslinked Polycaprolactam Systems","authors":"S. D. Bruck","doi":"10.6028/jres.066A.050","DOIUrl":"https://doi.org/10.6028/jres.066A.050","url":null,"abstract":"The relative ultraviolet stability of four chemically modified polycaprolactam (Nylon-6) systems is discussed: methylmethoxylated fibers and three other fibers having methylene, disulfide, and alkylene sulfide crosslinks, respectively. The ultraviolet degradation of these systems is studied by means of a sensitive analytical technique in which the methylene (—CH2—) groups remaining in the chemically modified fibers after irradiation are converted to formaldehyde; the liberated formaldehyde is then reacted with chromotropic acid to give a colored product, the absorbancy of which can be determined spectrophotometrically. The results indicate that the data can be expressed by first order rate equations from which the rate constants may be calculated. The scission of the crosslinks is accompanied by a decrease in the internal orientation of the networks as shown by X-ray diffraction photographs.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"78 1","pages":"489 - 495"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84039786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A procedure is described for the separation of hafnium from zirconium and their individual determination. The sample is dissolved in sulfuric and hydrofluoric acids and the hydrofluoric acid removed by fuming. After dilution with water, the solution is transferred to a column containing a strong quaternary amine anion-exchange resin (Dowex-1). The hafnium is eluted with diluted (3.5 percent by volume) sulfuric acid solution. Zirconium is removed by elution with 10 percent by volume sulfuric acid solution. The elements are precipitated with cupferron, ignited, and weighed as the oxides. For samples containing from twenty to eighty percent of zirconium, a second separation of the hafnium fraction using the column is necessary.
{"title":"Separation of Hafnium from Zirconium and Their Determination: Separation by Anion-Exchange","authors":"L. A. Machlan, J. L. Hague","doi":"10.6028/jres.066A.053","DOIUrl":"https://doi.org/10.6028/jres.066A.053","url":null,"abstract":"A procedure is described for the separation of hafnium from zirconium and their individual determination. The sample is dissolved in sulfuric and hydrofluoric acids and the hydrofluoric acid removed by fuming. After dilution with water, the solution is transferred to a column containing a strong quaternary amine anion-exchange resin (Dowex-1). The hafnium is eluted with diluted (3.5 percent by volume) sulfuric acid solution. Zirconium is removed by elution with 10 percent by volume sulfuric acid solution. The elements are precipitated with cupferron, ignited, and weighed as the oxides. For samples containing from twenty to eighty percent of zirconium, a second separation of the hafnium fraction using the column is necessary.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"47 1","pages":"517 - 520"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88330144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper describes the preparation, analysis, and certification of a new series of standard samples. These samples consist of commercially pure titanium containing hydrogen at three levels (32 ppm, 98 ppm, and 215 ppm) and have been designated National Bureau of Standards Standard Samples Nos. 352, 353, and 354, respectively.
{"title":"Titanium Standards for Hydrogen Content","authors":"J. Sterling, F. J. Palumbo, L. Wyman","doi":"10.6028/jres.066A.049","DOIUrl":"https://doi.org/10.6028/jres.066A.049","url":null,"abstract":"This paper describes the preparation, analysis, and certification of a new series of standard samples. These samples consist of commercially pure titanium containing hydrogen at three levels (32 ppm, 98 ppm, and 215 ppm) and have been designated National Bureau of Standards Standard Samples Nos. 352, 353, and 354, respectively.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"23 1","pages":"483 - 487"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88330893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A batch adsorption equation was derived by integrating an irreversible rate equation obtained by neglecting the desorption term of the Langmuir adsorption-rate equation. The integrated equation was in reasonably good agreement with experiment and provided a means for determining from the data the parameters q0 and k1. These constants, namely, the adsorptive capacity and the adsorption rate constant, completely characterized the adsorption system at that temperature. Agreement was found between these batch adsorption parameters and their counterparts previously derived from column adsorption experiments when both types of adsorption were performed simultaneously.
{"title":"Batch Adsorption From Solution","authors":"W. V. Loebenstein","doi":"10.6028/jres.066A.052","DOIUrl":"https://doi.org/10.6028/jres.066A.052","url":null,"abstract":"A batch adsorption equation was derived by integrating an irreversible rate equation obtained by neglecting the desorption term of the Langmuir adsorption-rate equation. The integrated equation was in reasonably good agreement with experiment and provided a means for determining from the data the parameters q0 and k1. These constants, namely, the adsorptive capacity and the adsorption rate constant, completely characterized the adsorption system at that temperature. Agreement was found between these batch adsorption parameters and their counterparts previously derived from column adsorption experiments when both types of adsorption were performed simultaneously.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"1 1","pages":"503 - 515"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90636548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Calorimetric measurements of the heat of solution of nitronium perchlorate (NO2ClO4) and of a mixture of potassium nitrate and potassium perchlorate in aqueous potassium hydroxide have been made. These are combined to give: NO2ClO4(c)+4KOH(in5300H2O)→KClO4(c)+KNO3(c)+2KOH(in5300H2O)+H2O(liq)ΔH=−285.80±0.38kj/mole=−68.31±0.09kcal/molefrom which the standard heat of formation of nitronium perchlorate is calculated as ΔHf°(25°C)NO2ClO4(c)=37.19±1.0kj/mole=8.89±0.25kcal/mole,in which the uncertainty represents twice the estimated overall standard deviation of the result.
{"title":"Heat of Formation of Nitronium Perchlorate","authors":"A. A. Gilliland","doi":"10.6028/JRES.066A.045","DOIUrl":"https://doi.org/10.6028/JRES.066A.045","url":null,"abstract":"Calorimetric measurements of the heat of solution of nitronium perchlorate (NO2ClO4) and of a mixture of potassium nitrate and potassium perchlorate in aqueous potassium hydroxide have been made. These are combined to give: NO2ClO4(c)+4KOH(in5300H2O)→KClO4(c)+KNO3(c)+2KOH(in5300H2O)+H2O(liq)ΔH=−285.80±0.38kj/mole=−68.31±0.09kcal/molefrom which the standard heat of formation of nitronium perchlorate is calculated as ΔHf°(25°C)NO2ClO4(c)=37.19±1.0kj/mole=8.89±0.25kcal/mole,in which the uncertainty represents twice the estimated overall standard deviation of the result.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"1 1","pages":"447 - 449"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89704171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Relative intensities are reported for 180 lines of Cu I between 2600 A and 7200 A, observed in a 10-ampere copper arc. Oscillator strengths, normalized as closely as possible to the absolute scale, are derived from the observations.
{"title":"Spectral-Line Intensities and gf-Values in the First Spectrum of Copper","authors":"C. Corliss","doi":"10.6028/JRES.066A.051","DOIUrl":"https://doi.org/10.6028/JRES.066A.051","url":null,"abstract":"Relative intensities are reported for 180 lines of Cu I between 2600 A and 7200 A, observed in a 10-ampere copper arc. Oscillator strengths, normalized as closely as possible to the absolute scale, are derived from the observations.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"71 1","pages":"497 - 502"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85973030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effect of age, water-cement ratio, and evaporable-water content on the reaction of hardened cement paste with carbon dioxide was investigated, using small cylinders of cement paste. The rate and extent of the reaction are subject to manipulation by varying the evaporable water content of the paste. Pastes of different age and water-cement ratio tend to dry at different rates, and this difference exerts an important indirect effect on carbonation. Analysis of the specimens showed that less than one molecule of nonevaporable water was released for every molecule of carbon dioxide gained, except in paste of low water-cement ratio or at low levels of carbonation in other pastes. If calcium hydroxide were the only phase attacked, equimolecular CO2–H2O stoichiometry would be expected. The observed behavior does not rule out the possibility of some preferential attack on calcium hydroxide, but other phases can react while calcium hydroxide is still present. Water-cement ratio, particularly in very dense paste, may exert some effect on the comparative accessibility of different phases.
{"title":"Reaction of Hardened Portland Cement Paste With Carbon Dioxide","authors":"C. M. Hunt, L. Tomes","doi":"10.6028/jres.066A.048","DOIUrl":"https://doi.org/10.6028/jres.066A.048","url":null,"abstract":"The effect of age, water-cement ratio, and evaporable-water content on the reaction of hardened cement paste with carbon dioxide was investigated, using small cylinders of cement paste. The rate and extent of the reaction are subject to manipulation by varying the evaporable water content of the paste. Pastes of different age and water-cement ratio tend to dry at different rates, and this difference exerts an important indirect effect on carbonation. Analysis of the specimens showed that less than one molecule of nonevaporable water was released for every molecule of carbon dioxide gained, except in paste of low water-cement ratio or at low levels of carbonation in other pastes. If calcium hydroxide were the only phase attacked, equimolecular CO2–H2O stoichiometry would be expected. The observed behavior does not rule out the possibility of some preferential attack on calcium hydroxide, but other phases can react while calcium hydroxide is still present. Water-cement ratio, particularly in very dense paste, may exert some effect on the comparative accessibility of different phases.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"39 1","pages":"473 - 481"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82191071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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