Vapour Pressure-temperature Relation Research Articles

Bondline strength evaluation of cocure/precured honeycomb sandwich structures under aircraft hygro and repair environments

Effects of moisture accumulated into the adhesively bonded composite structures on their bondline mechanical strengths are investigated through a series of comparative experiments. Those composite structures include a honeycomb sandwich structures fabricated by the cocure and the precure processes. Mass of moisture accumulated into the closed cells of the honeycomb sandwich panel specimens has been calculated. A pressure due to the vapor expansion in each cell of the sandwich panel has also been obtained for the minimum repair pressure to be applied to the laminate patched area by vapor pressure–temperature relations from the thermodynamic steam table, the ideal gas state equation and two vapor pressure equations. The bondline strengths of the laminated skins on the flat surface of honeycomb have been compared by the flatwise tension test and climbing drum peel test for dry, wet and repair-after-wet specimens, respectively.

Estudio teórico de algunas propiedades termodinámicas de los ácidos grasos obtenidos como destilados en la desodorización de aceites comestibles

Nowadays the feasibility of a change of technology in the deodorization stage of edible vegetable oil refining is being investigated. The proposed technology involves a modification in the composition of the distillates coming from the deodorization stage and their further treatment To design the apparatus which are required by the proposed technology it is necessary to study the physical properties of the distillates. The thermodynamic properties of the fatty acids: palmitic, stearic, oleic and linoleic, which are the principal components produced at the deodorization stage have been studied. The properties that have been studied were those corresponding to the critical point (critical temperature, pressure and volume), the vapour pressure-temperature relation and the latent heat of vaporisation. Different methods to estimate the above mentioned properties and some experimental published data have been compared.

Flame spread on aviation fuels

Abstract Flame spread rates and flame spread induction times have been measured for JP-5, JP-8 and mixtures of these fuels over the temperature range 10–90°C. The flame spread data were correlated on the basis of the initial liquid temperature relative to the closed cup flashpoint. Liquid-phase-controlled flame spread is observed for liquid temperatures 15°C above the closed cup flashpoint, flame spread is via gas-phase-controlled flame spread and flame spread rates range from 12 to 160 cm/s. The transition at V = 12 cm/s and the maximum flame spread rate are consistent with present knowledge of gas-phase flame spread and burning velocities. Differences between the present data and other available data from the literature are the result of differences in flashpoint interpretation for hydrocarbons versus alcohols and the use of very narrow flame spread pans by early investigators. The use of pans of only 1–6 cm causes large changes in flame spread rate with temperature which are not observed in wider pans. Therefore the use of narrow tray flame spread experiments gives an incorrect indication of the flame spread rate to be expected in large-scale (realistic) conditions. Pan widths of at least 20 cm are required to avoid these small-pan-width effects. Variations in the flashpoint of mixtures of JP fuels were successfully predicted using the method of Affens and McLaren by treating each JP fuel as a single fuel characterized by a single vapour pressure-temperature relation and assuming that mole fractions in the liquid phase may be approximated by the volume fraction of the JP fuel. Flame spread induction times were shown to be a function of the liquid temperature relative to the closed cup flashpoint. The induction time was also shown to be dependent on the strength and nature of the ignition source.

Exactly integrated Clapeyron equation. Its use to calculate quantities of phase change and to design vapor pressure-temperature relations

Exactly integrated Clapeyron equation. Its use to calculate quantities of phase change and to design vapor pressure-temperature relations

New saturated vapour pressure—temperature relation

Using the dimensionless coordinates ▪ ▪ an empirical vapour pressure—temperature relation of the form ▪ has been established along the two-phase saturation equilibrium curve over the entire liquid range up to the critical point. Comparison with experimental values for a series of selected organic, inorganic and quantal fluids produced average percentage deviations ranging from 0.0054% to 0.8098% with an overall average percentage deviation of 0.4065% (340 data point pairs). The proposed relation compares excellently with other vapour pressure—temperature calculation methods.

The vapour pressure and resistivity of selenium at high temperatures

The vapour pressure and resistivity of liquid selenium have measured as a function of temperature by means of an internally heated pressure-vessel with argon as the pressure-medium. A vapour pressure–temperature relation has been derived for pressures and corresponding temperatures in the ranges 0·013–161·5 atm. and 432·5–1380°. At the lowest pressures, where the vapour should behave ideally, the heat of vaporisation derived is 23·1 kcal. mole–1. The resistivity has been measured over the range 390–1420°. Below 550°, the plot of log ρ against 1/T is linear and confirms semiconductive behaviour. In the range 550–1150°, the resistivity drops more markedly with temperature, but at the highest temperatures the change is diminished. The explanation offered qualitatively is that the selenium changes from a semiconductor to a metallic conductor as the chains in the liquid are thermally destroyed.

The boiling point relation for tellurium at elevated pressures

The boiling points of tellurium at elevated pressures have been determined by means of an internally heated pressure-vessel with argon as the pressure medium. A vapour pressure–temperature relation has been derived for pressures and corresponding temperatures in the ranges 0·043–21 atm. and 708–1507°, respectively. By means of the tabulated free-energy functions, an approximate virial coefficient has been derived for the vapour, and has been used to evaluate ideal heats of vaporisation from the pressure–temperature relation up to 1400°K.

The heat of vaporization of equilibrium hydrogen

The apparent heat of vaporization of 20.4°K-equilibrium hydrogen has been measured in the temperature range between the triple point, 13.8°K, and 24°K. A vapour pressure-temperature relation for equilibrium hydrogen in this temperature range was calculated, using Clapeyron's equation, from the experimental results for the apparent heat of vaporization. 20.267°K was taken for the temperature of the normal boiling point. Also the true heat of vaporization was calculated from these results. In addition to these measurements the vapour pressure at the triple point was measured and the temperature of this point in the calculated p− T relation was evaluated. The result is p tr = 52.731 ± 0.010 mm Hg, 0°C and standard gravity and T tr = 13.802 ± 0.006°K. The results of the measurements and the calculations are discussed and examined on consistency with other data.

The vapour pressure of liquid nitrogen

The vapour pressure-temperature relation of liquid nitrogen has been measured from the boiling point to the triple point. Temperatures have been measured with platinum resistance thermometers. According to our experimental results the boiling point and the triple point temperatures of nitrogen are 77.343°K and 63.141°K on the average reduced scale, the triple point pressure is 93.91 mm Hg, 0°C. The vapour pressure of liquid nitrogen has been computed also from a thermodynamic vapour pressure-temperature relation for every degree from the triple point to the boiling point.

The determination of the boiling and triple points of equilibrium hydrogen and its vapour pressure-temperature relation

The boiling point of equilibrium hydrogen on the thermodynamic scale of temperature as realized at the National Physical Laboratory was found to be 20.2705° K. The mean value of all the determinations since 1930, recalculated to be consistent with the best values of the reference temperatures, is shown to be 20.267° K. The triple point of equilibrium hydrogen was found to be 13.816°K at a vapour pressure of 52.95 mmHg. The vapour pressure of equilibrium hydrogen was measured at ten temperatures over the range from the triple point to the boiling point. Second power and fourth power equations of (log p,T) were fitted by least mean square deviation. The average deviations of the observations were 1.8 millidegrees for the second power equation and 0.6 millidegree for the fourth power equation.

Equilibrium and kinetics of water exchange between rayon and detergent micelles in a hydrocarbon medium

Equilibrium conditions and exchange rates of water were determined in systems containing rayon, micelles of 2% OT in a hydrocarbon solvent, and solubilized water. Above 5.5% regain, the water regain of rayon is linearly dependent on the micellar water content. At 25°C., the water regain of rayon in 2% OT solutions is the same as in air. This relationship does not hold at other temperatures and at relative humidities over 80%. The vapor pressure-temperature relations for micellar water and water in rayon are comparable to those for water in concentrated electrolyte solutions, with the heats of vaporization comparable to those of pure water. A modified Raoult's law holds for the activity of solubilized water. The water may be conceived as forming a very concentrated electrolyte solution of the polar ends of the detergent molecules. The kinetics of water exchange between micelles and viscose rayon fabric were followed by D 2O tracer in the micellar water. A simple rate equation applies in the limited range of water contents studied. Every minute approximately 0.005 g. water exchanged per square meter of rayon surface. The water exchange between micelle and fabric may occur directly or may be mediated by water which is in true solution in the solvent.

Vapor Pressure—Temperature Relations and Heats of Solution and Dilution of the Binary System Manganous Nitrate—Water

Vapor Pressure—Temperature Relations and Heats of Solution and Dilution of the Binary System Manganous Nitrate—Water

Studies on the Vapor Pressure—Temperature Relations of the Binary System Zinc Nitrate—Water

Studies on the Vapor Pressure—Temperature Relations of the Binary System Zinc Nitrate—Water

Studies on the Vapor Pressure—Temperature Relations and on the Heats of Hydration, Solution and Dilution of the Binary System Magnesium Nitrate—Water

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStudies on the Vapor Pressure—Temperature Relations and on the Heats of Hydration, Solution and Dilution of the Binary System Magnesium Nitrate—WaterWarren W. Ewing, Ernst Klinger, and John D. BrandnerCite this: J. Am. Chem. Soc. 1934, 56, 5, 1053–1057Publication Date (Print):May 1, 1934Publication History Published online1 May 2002Published inissue 1 May 1934https://doi.org/10.1021/ja01320a014RIGHTS & PERMISSIONSArticle Views139Altmetric-Citations20LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (482 KB) Get e-Alerts Get e-Alerts

CALCIUM NITRATE. II. THE VAPOR PRESSURE-TEMPERATURE RELATIONS OF THE BINARY SYSTEM CALCIUM NITRATE-WATER

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCALCIUM NITRATE. II. THE VAPOR PRESSURE-TEMPERATURE RELATIONS OF THE BINARY SYSTEM CALCIUM NITRATE-WATERWarren W. EwingCite this: J. Am. Chem. Soc. 1927, 49, 8, 1963–1973Publication Date (Print):August 1, 1927Publication History Published online1 May 2002Published inissue 1 August 1927https://doi.org/10.1021/ja01407a018RIGHTS & PERMISSIONSArticle Views284Altmetric-Citations20LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (585 KB) Get e-Alerts Get e-Alerts