Showing papers in "Journal of research of the National Bureau of Standards in 1954"
TL;DR: In this article, the relative humidity-temperature relationship in air in equilibrium with saturated salt solutions of lithium chloride was determined in a temperature range of 0° to 50°C, using the dewpoint method.
Abstract: The relative humidity-temperature relationships have been determined in air in equilibrium with saturated salt solutions of lithium chloride. LiCl. H 2 O; magnesium chloride, MgCl 2 . 6H 2 O; sodium dichromate, Na 2 Cr 2 O 7 .2H 2 O; magnesium nitrate, Mg(NO 3 ) 2 . 6H 2 O; sodium chloride, NaCl; ammonium sulfate, (NH 4 ) 2 SO 4 ; potassium nitrate, KNO 3 ; and potassium sulfate, K 2 SO 4 , over a temperature range of 0° to 50°C, using the dewpoint method. The relative humidity is a continuous function of temperature, and, except for sodium chloride, is monotonic. The curve for sodium chloride increases from 74. 9 percent relative humidity at 0°C to a maximum of 75.6 percent at 30°C and then gradually decreases to 74.7 percent. The maximum change in relative humidity with temperature, about 15 percent relative humidity as the temperature increases from 0° to 50°C, occurs with saturated salt solutions of sodium dichromate and magnesium nitrate.
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TL;DR: The existence of binary compound s in the CaO-Ti02 system was con firmed in this paper, by means of solid-sta te reactions and by the observation of fu sion characteristics.
Abstract: The systems CaO-Ti02 and Zr0 2-Ti02 were studied by means of solid-sta te reactions and by the observation of fu sion characteristics. The existence of t wo binary compound s in the CaO-Ti02 system was con firmed . One co mpound was fo und to exist in the Zr02-1 i02 system. This compound , Zr02·Ti02, has been found to have orthorhombi c sy mmetry wi th t he following para meters at roo m temperature : a = 4.806 A, b= 5.032 A, c= 5.447 A. Solidsolu tion development was observed in t he Zr02-Ti 02 system, bu t not in t he CaO-Ti 0 2 system. From t he data obtained , an equilibr ium di agram is suggested fo r each system.
61 citations
TL;DR: To obtain a quantitative measure of merit of test mothods, a concept-sensitivity is introdueed and a slatislCcal t est of significance -is derived for the ratio of sensitivities of alternatiye methods of test.
Abstract: In the evaillation of mall Y methods of test, t h e t \\\\'O usual cri tenaprecision and aCCl!racy-are inwmcient. Accuracy is only applicable wh ere comparisons with a standard can be made. Preci ~ion, when interpreted as degree of r eproducibiltty, is ]Jot necessarily a measure of merit , becallse a method may be high ly reproducible merely because it is too crude to detect small variations. To obtain a quantitative measure of merit of test mothods, a no\\y concept-sensitivityis introdueed. If lV is a measure of some property Q, and lIM its standard de\\' iation, the sensitivity of lIf, denoled \"';II, is defined by the relation \"'u=(dM/dQ) / IIM. It follows from this definition that lhe ~cnsit.ivi l v of a test method mayor mal' not be constant fOl' all values of the properly Q. A slatislCcal t est of significance -is derived for the ratio of sensitivities of alternatiye methods of test. Unlike the standa rd deviation and the coefficient of variation, sensitivity is a lllC'aSllre of merit that IS invariant with respect lo any functional transformation of the mcasnI\"emC' nt , and is therefore independent of the scale in which the measurement is expressed .
49 citations
TL;DR: In this paper, the index of refraction of fused quartz glass was determined for 24 wavelengths from 0.34669 to 3.5078 microns, using the minimum deviation method.
Abstract: The index of refraction of fused quartz glass was determined for 24 wavelengths from 0.34669 to 3.5078 microns, using the minimum deviation method. The whole range is covered with a single instrument. The variation in index between samples was determined and no definite variations in dispersion were observed. Possible relations between purity and index are discussed.
40 citations
TL;DR: In this paper, a mixture of combustible liquids was used as a means of studying the preignit ion react ions in sll ch mixtures, and the usefulness of the une-temperature cu r ves of a t.
Abstract: , l~he m~ t,hods prev iously used fo r dete rminat,ion of the ignit ion temperatures of liqllid s~ a le, bllefty l evlewed, and the la rge dlscrepanc lCs 111 repo rted values no ted, Var iou s factors ~vh~ch affect the determmed values of ign it ion temperature are d iscussed. A p ract ical IgmtlOn apparatll s cons l ~t ll1 g , In ]Jart of an ,in sulated spherical flask, des igned to prov ide cOlldltlOns favorable to low Ignition tempe rature values, IS desc ribed, and data obtai ned With thiS apparatus on a co nsiderable number of combustible liquids a re presented. The usefulness of , t une-temperature cu r ves of a t.hermoco uple junction placed in mix t ures of ?ombu\"tIble liqu id a nd a ll', as a means of studying the preignit ion react ions in s Ll ch mixtures IS Ill ustrated .
40 citations
TL;DR: In this article, a study of the effects of titanium, tungsten, molybdenum, and vanous hydrochlonc-hydroflounc acid media is presented.
Abstract: The r es ul.ts of a ~ysten;atic study of t~e elution be~lavior of titanium, tungsten, moly b d enum, and 11l0blUm In vanous hydrochlonc-hydroflounc acid media are given. These data de~onstrate the behavior . of the anion c . omplex~s of thes~ el~ments on an anion-exchange r eSIn ~olumn. The posslbJI Jt y of severallllter es tJJl g quantItat Iv e separations is eviden t, and expenmen ts are descnbed t hat demons trate that t hese elem ents can be sepa rated from ea ch other.
33 citations
TL;DR: In this paper, the specific heat in the main is intermediate between the previous calculations, with improved spectroscopic constan ts, it bas become possible to carry out a recalculation of greater accuracy.
Abstract: Thermodynamic functions for carbon dioxide were compu ted by Kassel [1] / whose values were corrected to more recent values of the physical constan ts and extended from 3,500° to 5,000° K by Wagman , et al. [2]. Values by H. L . Jolmston have been given by Ellenwood, Kulik , and Gay [3]. A ubsequen t calculation by Gratch [4] differed appreciably, showing a somewhat different behavior at elevated temperatme. With improved spectroscopic constan ts, it bas become possible to carry out a recalculation of greater accuracy. Values obtained for the specific heat in the main are intermediate between the previous calculations.
TL;DR: In this article, the Onsager theory of the static dielectric constant of polar liquids has been modified to allow for t he influence of molecular shape, and the required molecular shapes are in general accord with the actual molecular geometries.
Abstract: The Onsager theory of the static dielectric constant of polar liquids has bee n modified to allow for t he influence of molecular shape. Equations have been derived for bot h prolate and oblate spheroids in which the permanent dipole is directed along t he axis of symmetry . These equations have beep applied to a number of pure polar liquids, exclusive of t he hydrogen bonded liquids, where reliable data were available over extended ranges of temperat ure. A satisfactory interpretation of the variation of dielectric constant with temperature is obtained provided the volume of t he molecular cavity is maintained fixed and independent of temperat ure rather than allowed to expand in proportion to t he molar volume as assumed by Onsager. The required molecular shapes are in general accord with the actual molecular geometries. The behavior of dilute solutions and mixt ures with a nonpolar solvent are also satisfactorily correlated using the same shape parameters. It appears to he unnecessary to consider specifi c interactions between neighboring molecules in order to account for the static dielectri c behavior of t hese systems.
TL;DR: The infrared spectra of gaseous tetrabromoethylene from 22 to 52 j1. have been determined as discussed by the authors, and several hitherto unobserved bands were found.
Abstract: The infrared spectra of gaseous tet raftuoroethylene from 22 to 52 j1. and liquid tetrachloroethylene from 3 to 52 j1. have been determined. Several hitherto unobserved bands were found. N ew and sati sfactory assignments, for which a detailed discussion is given, have been achieved. The ou t-of-plane force co nstants are di scussed and used to predict the wagging and torsion frequ encies of tet rabromoethylene. Tables of the thermodynamic fun ctions for tetrafluoroand tetrach loroethy lene are presented .
TL;DR: In this article, a critical study has been made of the techniques used at the National Bureau of Standards with Bingham viscometers and Cannon kinematic viscometer for determining the viscosities of four hydrocarbon liquids in the range 0.4 to 40 centipoises.
Abstract: : A critical study has been made of the techniques used at the National Bureau of Standards with Bingham viscometers and Cannon kinematic viscometers. All corrections applicable to measurements with these instruments were critically examined. Instruments of each type were calibrated using the viscosity of water at 20 deg C as the primary viscosity standard. The viscometers were used to determine the viscosities of four hydrocarbon liquids in the range 0.4 to 40 centipoises. With each liquid, the values obtained in the two types of viscometers were in agreement by 0.05 percent or better, indicating that no gross error was involved in the use of either instrument. It is considered, however, that the inherent relative simplicity of operation of the kinematic viscometer makes it a preferable instrument for this type of measurement.
TL;DR: In this paper, the spectral energy distribution of direct solar radiation, made in July 1953, at Sacramento P eak, New Mexico, altitude 9,200 feet, is described.
Abstract: Measurements on the spectral energy distribution of direct solar radiation, made in July 1953, at Sacramento P eak, New Mexico, altitude 9,200 feet are described . Spectral data a re given for wavelengths extending from 299 to 535 millimicrons for ai r masses 0, 1.0,2.0, and 3.0. A determination of atmospheric transmittance as a function of wavelength results in calculated total amounts of ozone approximating 0.21 centimeter (ntp) as a mean for 4 days during JUly. Preliminary measurements, employing a lead sulfide photoconducting cell, in the visible and infrared spectrum are discussed. On the basis of the spectral ultraviolet data obtained , an estimate of a value slightly exceeding 2.00 langleys per minute for the solar constant is indicated.
TL;DR: In this paper, a study of creep behavior in tension at 300 0 700 0 900 0 and 1 200 0 F of initi,!I y annealed high-purity nickeL Discontinuous flow was dbsel' v~d in the three stages of creep, and.it was affected by ~e mperatu~'e, s train rate, and prior-strain history.
Abstract: ,~ study was made of t he creep behavior in tension at 300 0 700 0 900 0 and 1 200 0 F of initi, !I y annealed high-purity nickeL Discontinuous flow was dbsel' v~d in ~ach of' the three stages of creep, and .it was affected by ~e mperatu~'e, s train rate, and prior-strain history. The phenomenon of s tram aglllg was especially promlll ent at 3000 F as manifested by t he attainment of an appreciable creep life in specimens stressed in excess of the tens ile streno-th at this temperatur~. The experimentall'esults are analyzed in terms of t he past and prese~ t theor ies of deformat IOn of metals. Stralll hardenlllg, recovery, and t he initiation , propagation , and types of fractures obtamed dunng creep are further evaluated by means of true-stresstruestrain and hardness data obtained at room temperature and by metallographic examination of the fractured specimens.
TL;DR: In this article, the vapor pressure of nitrogen has been measured in the liquid range below th e normal bOl~tng pOl.n t calculated from t hIs equatIOn IS 77.364° K.
Abstract: . . The vapor pressure of nitrogen has been measured in the liquid range below th e normal bOl~tng pOl.nt and .can be r epresented b:y log P .(mm) = 6.49594 255 .821 j (T 6.600) . The normal bOIling pOl.n t calculated from t hIs equatIOn IS 77.364° K . Ni trogen vapor densities along. t he sa t l!rat lOn hoe are represented by log pT= 3.39858 282.953j( T 3.83). The fugaCity functIOn In f jp for t he sa t ura ted vapor is tabulated.
TL;DR: A series of measuremenLs has been compleLed in which the Canadian national radium standard and the British and NiLed SLaLes primary radium tandards were compared with each other at the National Physical Laboratory, Teddington, England [1],i at the N Research Council's Laboratory, Ottawa, Cana,da [2], and at Lhe National Bureau of Standards, Washington, D. C. as mentioned in this paper.
Abstract: A series of measuremenLs has been compleLed in which the Canadian national radium standard and the British and niLed SLaLes primary radium tandards were compared with each other at the National Physical Laboratory, Teddington, England [1],i at the National Research Council's Laboratory, Ottawa, Cana,da [2], and at Lhe National Bureau of Standards, Washington, D. C. [3]. The measurements at the K ational Bureau of Standards were made by means of the NBS sLandard electroscope [4], the radiation balance, and Geiger~hiller and scintillation counters. The r adiation balance already described [5] was far too small to accommorlate the large Honigschmid standards, which arc approximately 38 mm long with an external diameter of about 3.5 mm. The Canadian national radium standard is of considerably smaller dimensions, 10.5 mm long and 2.0-mm exlernal diameter, and could be inserted into the cups of the first balance. The radiation balance conslructed to accommodate these Honigschmid standards is described here.
TL;DR: In this article, Callendar described a radio-balancing meter for measurement of radiant energy in which the quan t ity of heat to be m easured is balanced against the co-operation of a P elti er co uple.
Abstract: In 1910 H . L. Callendar described a calori meter for measurement of radiant energy in which the quan t ity of heat to be m easured is balanced against the coo ling f rom a P elti er co uple. H e called t his t hermal-balance device a \" radio-bala nce.\" T he operation of t he radio-balance has been extensively invest igated to see wh ether it co uld be used for t he accurate determinat ion of the ene rgy emiss ion from radioact ive sour ces. In the presen t experiments, meas urements have been confin ed sole ly to radium preparat ions. For an absorp t ion equi valent to 0.126 em of lead a h eat emission of 128.9 cal !e l hrl has been founrl fo r radium in equilibri um with its products down t.o rad ium D . The est imated accu racy of t his resul t is ± 0 .7 perce n t.
TL;DR: In this paper, a number of solvent formulations were evaluated for the analysis of car bon-1 4 in CH-Iabeled su bstances by co unting, wi th a proport ional gas-flow co unter, t h E' r adioactive disintegrations ari sing from a m ateri al t hat is dissolved in a suitable solv cnt.
Abstract: A st udy is r eported of t he detennina t,ion of car bon-1 4 in CH-Iabeled su bstances by co unt ing, wi th a proport ional gas-flow co unter, t h E' r adioact ive disintegrations ari sing from a m ateri al t hat is dissolved in a s uitable solv cnt. A number of solvent.s were found to bc sat isfactor y . Form amide is recomm ended for t hc assay of carbohydr9.tes a nd other m aterials wi th which it is a comp atibl e solvent. Eth.vlene glycol is sui table for the assay of highl y alkali ne substances, a nd, in co nj unct ion with sequestering age nts, for t he assay of a lk a linc car th car bonates. Other useful sol vent s are dim ethyl fo rm amide and 90-pcrce nt phosphoric acid . T he co unt ing effi ciency in diffarent solvents was found to be inversely p roport ional to th e density of t he solu tion a nd highly reprod ucible. The st ud y sh ows that solu tions of CI4-labeled m aterials can be co unted easil y and prec ise!.v with a proport iona l counter.
Abstract: Samples of all of t he deuteroethylenes have become a vailable in satisfacto ry purity, and mass spectra have been measured and corrected for isotopic impurities. The mass spectra of cis and tmns dideuteroethylene are nearly identical, and the spectrum of t he asymmetrical dideuteroethylene is similar to the symmetrical molecules in t he mass range 24 to 30. The probability of removing an I-I atom from the deuteroethylenes relat ive to the probability in C2I-I4 is equal to t he a priori probabi lity times 1.10, (1.10)2, and (1.10)3 in molecules containing 1, 2, and 3 D atoms, and the relative probability of removing a D atom is 0.90 in C2D 4 and is nearly equal to the a priori probability times (0.90)2, (0.90)3, and (0.90)4 in molec ules C2I-ID3, C2I-I2D 2, and C2I-I3D, respectively. As t he factors 1.10 and 0.90 are nearly reciprocals, these rat ios can be expressed a s positive and negative powers of 1.10. The probabiliti es of removing 2, 3, or 4 atoms are powers or products of the probability of removing single atoms, and t hu s are a lso positive and negative powers of 1.10. Similar relatio ns are found i n t he previously publi shed data on deuteroacetylenes.
TL;DR: In this paper, an extension of the optical spectroscopic method for isotope analysis of gaseous mixtures of hydrogen and deuterium to mixture of water and heavy water is presented.
Abstract: Extension of the optical spectroscopic method for isotope analysis of gaseous mixtures of hydrogen and deuterium to mixtures of water and heavy water provides a direct method for determining total water content of materials, A determination can be made on a sample of less than Q*1 ml in less than 10 minutes to an accuracy of a few percent. Using a sample of at least 1 ml, an accuracy of the order of 0,1 percent is obtained in an hour or less. This paper describes the system and the investigation of optimum operating conditions and effect of variations in operating conditions on precision and accuracy of measurement as well as limitations of the technique, A sample of blood or serum can be measured directly almost as easily as one of distilled water. The optical spectroscopic method can be used to determine water content of most materials whether in the solid, liquid or gas phase.