{"title":"Flow in roof gutters","authors":"K. Beij","doi":"10.6028/JRES.012.017","DOIUrl":"https://doi.org/10.6028/JRES.012.017","url":null,"abstract":"","PeriodicalId":56324,"journal":{"name":"Bureau of Standards Journal of Research","volume":"12 1","pages":"193"},"PeriodicalIF":0.0,"publicationDate":"1934-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71342389","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}
{"title":"Comparative efficiencies of various dehydrating agents used for drying gases (A survey of commercial drying agents)","authors":"J. H. Bower","doi":"10.6028/JRES.012.022","DOIUrl":"https://doi.org/10.6028/JRES.012.022","url":null,"abstract":"","PeriodicalId":56324,"journal":{"name":"Bureau of Standards Journal of Research","volume":"12 1","pages":"241"},"PeriodicalIF":0.0,"publicationDate":"1934-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71342015","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 reports a method by which the purity of gases (and liquids having normal boiling points below room temperatures) may be critically tested. The method involves one approximately isothermal distillation, whereby a small initial distillate, a middle cut, and a small final residue are obtained. The pressures of these three fractions are intercompared by means of a simple differential manometer and form the basis for indicating impurities of higher and lower boiling points than that of the approximately pure substance. The method eliminates the exacting temperature requirements of the widely used criterion of constancy of pressure during an isothermal condensation or vaporization. At the same time, it offers more information than the isothermal condensation, and is suitable for testing mixtures containing more than two components. In many cases the order of magnitude of the impurities may be calculated. Like the isothermal condensation, it is not suitable for studying azeotropic mixtures. The preparation of a pure gas is not an easy matter, and satisfactory tests for purity are often difficult to formulate and usually difficult to perform. In many cases the method of preparation is about as good a guarantee of purity as the method of test subsequently applied, and sometimes it offers even more reliable assurance of purity. These complications are largely responsible for the fact that reported investigations deal abundantly with gases of doubtful purity. The ordinary methods of so-called " exact" volumetric gas analysis, which are often employed in the effort to establish the purity of a gas, are subject to errors of such magnitude as to be unfit for this purpose. It is sometimes possible to design very special chemical methods which may offer satisfactory evidence of purity. In general, however, the measurement of one or more of the physical properties of a gas affords the basis for the determination of its purity. One of the most frequently employed criteria for purity is the constancy of pressure during isothermal condensation or vaporization. The method is very useful, but has limitations which are not generally recognized. Washburn * has discussed the physical limitations of this method. In this connection, Washburn suggested a more sensitive and convenient method for determining purity in case the substance to be examined is nearly pure. This suggestion is given on page 595 (paragraph 3) of his paper, and forms the basis of the method described in the present discussion. The apparatus and detailed technique, which have been found suitable for the application of this method, are reported in order to make the method easily available. At the same time, the original suggestion has been extended in order to permit the collection of additional information. 1 E. W. Washburn, Constancy of pressure during isothermal condensation or vaporization as a criterion of purity, Zs. physik. Chemie (Cohen-Festband), p. 592, 1927.
本文报告了一种方法，通过该方法可以严格测试气体(和具有低于室温的正常沸点的液体)的纯度。该方法涉及一次近似等温蒸馏，由此获得少量初始馏出物、中间切割物和少量最终残留物。用一个简单的差压计来比较这三种馏分的压力，并以此作为指示沸点高于或低于近似纯物质的杂质的基础。该方法消除了在等温冷凝或汽化过程中广泛使用的压力恒定标准的严格温度要求。同时，它比等温冷凝提供了更多的信息，适合于测试含有两种以上组分的混合物。在许多情况下，可以计算出杂质的数量级。与等温凝结一样，它不适合研究共沸混合物。制备纯气体不是一件容易的事，纯度的满意测试通常很难制定，通常也很难执行。在许多情况下，制备方法与随后应用的检验方法一样能很好地保证纯度，有时它甚至能提供更可靠的纯度保证。这些复杂情况在很大程度上造成了报告中的调查大量涉及纯度可疑的气体。通常用于确定气体纯度的所谓“精确”体积气体分析的普通方法容易产生如此大的误差，以致于不适合此目的。有时可以设计出非常特殊的化学方法，以提供令人满意的纯度证据。然而，一般来说，测量气体的一种或多种物理性质为确定其纯度提供了基础。最常用的纯度标准之一是等温冷凝或汽化过程中的压力恒定。这种方法很有用，但也有不被普遍认识到的局限性。Washburn *已经讨论过这种方法的物理局限性。在这方面，沃什伯恩提出了一种更灵敏和方便的方法来确定纯度，以防被检查的物质几乎是纯的。这一建议载于他的论文第595页(第3段)，并构成了本讨论中所述方法的基础。为了使该方法易于实现，本文报道了适合于该方法应用的装置和详细技术。同时，为了能够收集更多的资料，原来的建议已被延长。1 E. W.沃什伯恩，作为纯度标准的等温冷凝或蒸发过程中的压力常数，Zs。物理学。化学(cohen - fest)，第592页，1927年。
{"title":"A critical test for the purity of gases","authors":"M. Shepherd","doi":"10.6028/JRES.012.016","DOIUrl":"https://doi.org/10.6028/JRES.012.016","url":null,"abstract":"This paper reports a method by which the purity of gases (and liquids having normal boiling points below room temperatures) may be critically tested. The method involves one approximately isothermal distillation, whereby a small initial distillate, a middle cut, and a small final residue are obtained. The pressures of these three fractions are intercompared by means of a simple differential manometer and form the basis for indicating impurities of higher and lower boiling points than that of the approximately pure substance. The method eliminates the exacting temperature requirements of the widely used criterion of constancy of pressure during an isothermal condensation or vaporization. At the same time, it offers more information than the isothermal condensation, and is suitable for testing mixtures containing more than two components. In many cases the order of magnitude of the impurities may be calculated. Like the isothermal condensation, it is not suitable for studying azeotropic mixtures. The preparation of a pure gas is not an easy matter, and satisfactory tests for purity are often difficult to formulate and usually difficult to perform. In many cases the method of preparation is about as good a guarantee of purity as the method of test subsequently applied, and sometimes it offers even more reliable assurance of purity. These complications are largely responsible for the fact that reported investigations deal abundantly with gases of doubtful purity. The ordinary methods of so-called \" exact\" volumetric gas analysis, which are often employed in the effort to establish the purity of a gas, are subject to errors of such magnitude as to be unfit for this purpose. It is sometimes possible to design very special chemical methods which may offer satisfactory evidence of purity. In general, however, the measurement of one or more of the physical properties of a gas affords the basis for the determination of its purity. One of the most frequently employed criteria for purity is the constancy of pressure during isothermal condensation or vaporization. The method is very useful, but has limitations which are not generally recognized. Washburn * has discussed the physical limitations of this method. In this connection, Washburn suggested a more sensitive and convenient method for determining purity in case the substance to be examined is nearly pure. This suggestion is given on page 595 (paragraph 3) of his paper, and forms the basis of the method described in the present discussion. The apparatus and detailed technique, which have been found suitable for the application of this method, are reported in order to make the method easily available. At the same time, the original suggestion has been extended in order to permit the collection of additional information. 1 E. W. Washburn, Constancy of pressure during isothermal condensation or vaporization as a criterion of purity, Zs. physik. Chemie (Cohen-Festband), p. 592, 1927.","PeriodicalId":56324,"journal":{"name":"Bureau of Standards Journal of Research","volume":"12 1","pages":"185"},"PeriodicalIF":0.0,"publicationDate":"1934-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71342351","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}
{"title":"A glass electrode potentiometer system for the determination of the pH values of weakly buffered solutions such as natural and treated waters","authors":"J. O. Burton, H. Matheson, S. F. Acree","doi":"10.6028/JRES.012.007","DOIUrl":"https://doi.org/10.6028/JRES.012.007","url":null,"abstract":"","PeriodicalId":56324,"journal":{"name":"Bureau of Standards Journal of Research","volume":"12 1","pages":"67"},"PeriodicalIF":0.0,"publicationDate":"1934-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71342282","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}
In studies previously reported, information was obtained relative to causes of serious economic waste in offset lithography resulting from misregister in color printing. At the request of the Lithographic Technical Foundation, which is cooperating with the Bureau of Standards, further studies were made to obtain scientific data on the reactions of lithographic papers to variations in atmospheric humidity and temperature. Paper is a hygroscopic substance. Its moisture content is determined by the hygroscopic condition of the surrounding air, and its properties, particularly dimensional, are governed to considerable extent by moisture content. Since precise register requires constant dimensions, the influence of atmospheric changes was closely studied. The dimensions of the papers varied directly with the miosture content regardless of the cause of the moisture changes. Moisture content was influenced by relative humidity, temperature, and history of conditioning Humidity changes were most important. A 10-point change affected the moisture content sufficiently to alter the dimensions enough to cause serious misregister. Temperature effects were less important, but of sufficient magnitude to call for close control in printing. History of conditioning had an important influence on equilibrium moisture content, hence on dimensions. The paper that gave best register in printing had the lowest coefficient of expansion in the machine direction, and the paper that gave the largest misregister had the highest. The papers with low expansion in the machine direction have correspondingly high expansion in the cross direction, which indicates the desirability of large directional difference in fiber formation of offset papers. The low coefficient of expansion in machine direction for the papers giving best register, indicated that distortion in printing which affects register is caused largely by moisture content variations. The usual sizing materials had little influence on the moisture content response of paper to changing relative humidity except with respect to the rate of change. Both surface sizing and mineral coatings increased the total dimensional changes per unit of moisture content change. The effects of ordinary atmospheric changes on strength properties were not of sufficient magnitude to be of significance in lithography. CONTENTS Page
{"title":"Reactions of lithographic papers to variations in humidity and temperature","authors":"C. G. Weber, L. Snyder","doi":"10.6028/JRES.012.006","DOIUrl":"https://doi.org/10.6028/JRES.012.006","url":null,"abstract":"In studies previously reported, information was obtained relative to causes of serious economic waste in offset lithography resulting from misregister in color printing. At the request of the Lithographic Technical Foundation, which is cooperating with the Bureau of Standards, further studies were made to obtain scientific data on the reactions of lithographic papers to variations in atmospheric humidity and temperature. Paper is a hygroscopic substance. Its moisture content is determined by the hygroscopic condition of the surrounding air, and its properties, particularly dimensional, are governed to considerable extent by moisture content. Since precise register requires constant dimensions, the influence of atmospheric changes was closely studied. The dimensions of the papers varied directly with the miosture content regardless of the cause of the moisture changes. Moisture content was influenced by relative humidity, temperature, and history of conditioning Humidity changes were most important. A 10-point change affected the moisture content sufficiently to alter the dimensions enough to cause serious misregister. Temperature effects were less important, but of sufficient magnitude to call for close control in printing. History of conditioning had an important influence on equilibrium moisture content, hence on dimensions. The paper that gave best register in printing had the lowest coefficient of expansion in the machine direction, and the paper that gave the largest misregister had the highest. The papers with low expansion in the machine direction have correspondingly high expansion in the cross direction, which indicates the desirability of large directional difference in fiber formation of offset papers. The low coefficient of expansion in machine direction for the papers giving best register, indicated that distortion in printing which affects register is caused largely by moisture content variations. The usual sizing materials had little influence on the moisture content response of paper to changing relative humidity except with respect to the rate of change. Both surface sizing and mineral coatings increased the total dimensional changes per unit of moisture content change. The effects of ordinary atmospheric changes on strength properties were not of sufficient magnitude to be of significance in lithography. CONTENTS Page","PeriodicalId":56324,"journal":{"name":"Bureau of Standards Journal of Research","volume":"12 1","pages":"53"},"PeriodicalIF":0.0,"publicationDate":"1934-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71342231","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}
{"title":"Analysis of wool-cotton textiles","authors":"R. Mease, D. A. Jessup","doi":"10.6028/JRES.012.008","DOIUrl":"https://doi.org/10.6028/JRES.012.008","url":null,"abstract":"","PeriodicalId":56324,"journal":{"name":"Bureau of Standards Journal of Research","volume":"12 1","pages":"75"},"PeriodicalIF":0.0,"publicationDate":"1934-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71342292","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}
Measurements U'1f8 been made of the wind pressure over a model « the Empire State Building as affected by the presence of n~hboring mO'dels'Simulat ing btrildiup which mipt be erected on the adjacent blocks. Tire m,ject was to determine the shielding effect for different directions of the wind. . While the pressure on certain faces of the building was increased somewhat by the presence of the neishboring'structures, the resultant of pressure on the windward face and aumoD on the lee face was decreased. The decrease was greatest when the Interfering structure was close by and directly upstream. The height shielded was Dot so great as the height of the interfering structure. Shielding may produce a variation in the twisting moment about a vertical asis at different levels. The stresses set up by this loading may require con sideration in special cases.
{"title":"Influence of neighboring structures on the wind pressure on tall buildings","authors":"C. Harris","doi":"10.6028/JRES.012.010","DOIUrl":"https://doi.org/10.6028/JRES.012.010","url":null,"abstract":"Measurements U'1f8 been made of the wind pressure over a model « the Empire State Building as affected by the presence of n~hboring mO'dels'Simulat ing btrildiup which mipt be erected on the adjacent blocks. Tire m,ject was to determine the shielding effect for different directions of the wind. . While the pressure on certain faces of the building was increased somewhat by the presence of the neishboring'structures, the resultant of pressure on the windward face and aumoD on the lee face was decreased. The decrease was greatest when the Interfering structure was close by and directly upstream. The height shielded was Dot so great as the height of the interfering structure. Shielding may produce a variation in the twisting moment about a vertical asis at different levels. The stresses set up by this loading may require con sideration in special cases.","PeriodicalId":56324,"journal":{"name":"Bureau of Standards Journal of Research","volume":"12 1","pages":"103"},"PeriodicalIF":0.0,"publicationDate":"1934-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71342442","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}
{"title":"Data on the spectral erythemic reaction of the untanned human skin to ultraviolet radiation","authors":"W. Coblentz, R. Stair","doi":"10.6028/JRES.012.004","DOIUrl":"https://doi.org/10.6028/JRES.012.004","url":null,"abstract":"","PeriodicalId":56324,"journal":{"name":"Bureau of Standards Journal of Research","volume":"12 1","pages":"13"},"PeriodicalIF":0.0,"publicationDate":"1934-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71342221","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 reports the results of spectral reflection measurements of one set of the official standards for the grades of abacd used in cordage. The results provide a quantitative record of those characteristics of the fiber on which the color depends. They should be of permanent value since the grading is largely on the basis of color. They suggest the possibility of using quantitative reflectance measurements in the Philippine Islands to supplement, if not to replace, the present method of grading abac£ for color. Three specimens representing the base, tip, and middle of each of 10 standard samples were measured at seven wave lengths. The average values found for the spectral reflectance at wave length 500 mju, which are illustrative of the results, follow: Superior current 59.3, good current 54.9, midway 49.9, 25 percent over fair current 46.5, streaky two 45.4, streaky three 33.5, fair current 42.5, superior seconds 40.0, soft seconds 31.3, soft brown 21.5. The highest and lowest measurement for a given standard differ by from 2 to 13 units and there is decided overlapping in the measurements for some of the different grades.
{"title":"Spectral reflectance of the Philippine Island Government standards for abaca fiber","authors":"G. Becker","doi":"10.6028/JRES.011.058","DOIUrl":"https://doi.org/10.6028/JRES.011.058","url":null,"abstract":"This paper reports the results of spectral reflection measurements of one set of the official standards for the grades of abacd used in cordage. The results provide a quantitative record of those characteristics of the fiber on which the color depends. They should be of permanent value since the grading is largely on the basis of color. They suggest the possibility of using quantitative reflectance measurements in the Philippine Islands to supplement, if not to replace, the present method of grading abac£ for color. Three specimens representing the base, tip, and middle of each of 10 standard samples were measured at seven wave lengths. The average values found for the spectral reflectance at wave length 500 mju, which are illustrative of the results, follow: Superior current 59.3, good current 54.9, midway 49.9, 25 percent over fair current 46.5, streaky two 45.4, streaky three 33.5, fair current 42.5, superior seconds 40.0, soft seconds 31.3, soft brown 21.5. The highest and lowest measurement for a given standard differ by from 2 to 13 units and there is decided overlapping in the measurements for some of the different grades.","PeriodicalId":56324,"journal":{"name":"Bureau of Standards Journal of Research","volume":"11 1","pages":"823"},"PeriodicalIF":0.0,"publicationDate":"1933-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71342175","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}
{"title":"Comparison of natural aging of paper with accelerated aging by heating","authors":"R. Rasch, B. W. Scribner","doi":"10.6028/JRES.011.050","DOIUrl":"https://doi.org/10.6028/JRES.011.050","url":null,"abstract":"","PeriodicalId":56324,"journal":{"name":"Bureau of Standards Journal of Research","volume":"11 1","pages":"727"},"PeriodicalIF":0.0,"publicationDate":"1933-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71341561","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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