Bureau of Standards Journal of Research最新文献_第6页

ARC spectrum of silicon in the red and infrared 硅的ARC光谱中有红色和红外线

Bureau of Standards Journal of Research Pub Date : 1933-12-01 DOI: 10.6028/JRES.011.054

C. C. Kiess

引用次数: 1

Evaluation of manila-rope fiber for color 马尼拉绳纤维的颜色评价

Bureau of Standards Journal of Research Pub Date : 1933-12-01 DOI: 10.6028/JRES.011.057

G. Becker, W. Appel

{"title":"Evaluation of manila-rope fiber for color","authors":"G. Becker, W. Appel","doi":"10.6028/JRES.011.057","DOIUrl":"https://doi.org/10.6028/JRES.011.057","url":null,"abstract":"A quantitative method for the evaluation of the color of manila-rope fiber was developed at the request of the Cordage Institute and the Cordage Committee of the Federal Specifications Board. Spectral reflection and colorimetric measure- ments showed that the variations in color correspond chiefly to variations in luminous reflectance. The reflectance at wave length 500 nut, which is obtainable with relatively simple apparatus, was found to be sufficient for the grading of the fiber for color. The fibers in a cross section of the rope are cut into lengths of 1.5 to 2.5 mm, mixed, extracted with petroleum ether, and spread out to give a smooth surface. The ratio of the reflectance of this surface to that of the usual white standard magnesium oxide surface for light of wave length 500 mjt (when the two surfaces are in effect equally illuminated at an angle of approximately 45° and viewed in a line approximately perpendicular to the surfaces) multiplied by 100 gives the numerical value, \"Becker value\", for the rope. The Becker value of the commercial ropes tested varied from 29.0 to 51.0. Before removal of the lubricant the values were from 8 to 16 units lower. The value obtained for a single specimen taken from a coil of rope was found to be within two units of the average value for several specimens. The method is prescribed in the latest revision of the Federal specification for manila rope.","PeriodicalId":56324,"journal":{"name":"Bureau of Standards Journal of Research","volume":"11 1","pages":"811"},"PeriodicalIF":0.0,"publicationDate":"1933-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71342168","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}

引用次数: 2

Critical study of the determination of ethane by combustion over platinum in the presence excess oxygen 在过量氧存在下铂上燃烧测定乙烷的关键研究

Bureau of Standards Journal of Research Pub Date : 1933-12-01 DOI: 10.6028/JRES.011.055

M. Shepherd, J. R. Branham

{"title":"Critical study of the determination of ethane by combustion over platinum in the presence excess oxygen","authors":"M. Shepherd, J. R. Branham","doi":"10.6028/JRES.011.055","DOIUrl":"https://doi.org/10.6028/JRES.011.055","url":null,"abstract":"A sample of ethane of known purity was analyzed by the usual slow-combustion method; that is, over a hot platinum spiral in the presence of excess oxygen. The contraction after burning, the carbon dioxide produced, and the oxygen consumed were measured. The average results obtained from a series of 18 determinations indicated the impossibility of attaining the accuracies usually reported in the literature. The average volumetric equation for the reaction was C 2H 6 -|-3.5116 2 «= 1.9940 COii+ 2.5190 contraction. The weighted average eauation was CoH 6+ 3.513 2 «= 1.994 CO2+ 2.520 contraction. The contraction and oxygen consumed were invariably too high, and the carbon dioxide produced was invariably too low. The ethane was calculated from contraction, carbon dioxide, and oxygen separately and in various combinations, both uncorrected and corrected for deviations from theoretical molecular volumes. The average results from different methods of calculation varied from 99.13 percent to 100.76 percent. The best average value found by use of a single formula was 100.11 percent, and resulted from combining the contraction and carbon dioxide as one factor of an equation of which the other factor was oxygen. Such an equation eliminates part of the uncertainty concerning the proper method of correcting for deviation from theoretical molecular volumes. The averages of two pairs of formulas gave results very close to 100 percent. The ethane was also calculated on the assumption that methane, or propane, (known to be absent) was present. (The usual analysis would have been reported as methane and ethane.) Hydrocarbons other than ethane indicated by various methods of calculation from the average of the observed results varied from 0.3 percent of propane to 9.4 percent of methane. A number of sources of error are discussed. These include small measured losses of ethane and carbon dioxide in the distributor, and a small loss of carbon dioxide by solution in the water produced by the combustion and otherwise present. Such errors must be present in every apparatus of this type, and will effect the analysis of all hydrocarbons to some extent. The observed results may be explained by correcting for these errors, and for the known deviation of carbon dioxide from its theoretical molecular volume with a similar correction for ethane, which is somewhat higher than the best estimated value available.","PeriodicalId":56324,"journal":{"name":"Bureau of Standards Journal of Research","volume":"11 1","pages":"783"},"PeriodicalIF":0.0,"publicationDate":"1933-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71341612","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}

引用次数: 2

Effect of heat treatment on the expansivity of a pyrex glass 热处理对耐热玻璃膨胀率的影响

Bureau of Standards Journal of Research Pub Date : 1933-12-01 DOI: 10.6028/JRES.011.056

J. B. Saunders, A. Q. Tool

引用次数: 6

The isolation of mesitylene, pseudocumene, and hemimellitene from an Oklahoma petroleum 俄克拉何马州一种石油中三聚亚甲基、伪甲基烯和半甲基烯的分离

Bureau of Standards Journal of Research Pub Date : 1933-11-01 DOI: 10.6028/JRES.011.044

B. Mair, S. Schicktanz

引用次数: 5

Infrared absorption spectra of some plant pigments 一些植物色素的红外吸收光谱

Bureau of Standards Journal of Research Pub Date : 1933-11-01 DOI: 10.6028/JRES.011.047

R. Stair, W. Coblentz

引用次数: 20

The attraction between coils in the Rayleigh current balance 瑞利电流秤中线圈之间的吸引力

Bureau of Standards Journal of Research Pub Date : 1933-11-01 DOI: 10.6028/JRES.011.045

C. Snow

引用次数: 4

Formula for specific volumes of saturated vapors 饱和蒸气的比容公式

Bureau of Standards Journal of Research Pub Date : 1933-11-01 DOI: 10.6028/JRES.011.046

C. H. Meyers

引用次数: 1

Phase equilibria in the systems TiO2, TiO2-SiO2 and TiO2-Al2O3 TiO2、TiO2- sio2和TiO2- al2o3体系的相平衡

Bureau of Standards Journal of Research Pub Date : 1933-11-01 DOI: 10.6028/JRES.011.049

E. N. Bunting

引用次数: 51

Preparation of calcium lactobionate and lactobionic delta-lactone 乳酸酸钙和乳酸-内酯的制备

Bureau of Standards Journal of Research Pub Date : 1933-11-01 DOI: 10.6028/JRES.011.048

H. Isbell

引用次数: 5