Static Apparatus Research Articles

Phase equilibria and excess properties for binary systems in reactive distillation processes. Part II. Ethyl acetate synthesis

In this investigation isothermal vapor–liquid equilibrium data (VLE) and excess enthalpy (HE) data were measured for the binary systems required for the design of reactive distillation processes for the ethyl acetate production. The isothermal P–x data was measured with a static apparatus, the heat of mixing measurements were performed with a commercial isothermal flow calorimeter. To the experimental data from this work and mixture data from other authors temperature dependent UNIQUAC parameters were fitted.

Simultaneous measurement solubility of carbon dioxide + hydrogen sulfide into aqueous blends of alkanolamines at high pressure

Treatment of the sour natural gas is a major step in natural gas processing so that the acid gases such as H2S and CO2 are removed from natural gas stream. The acid gases are harmful to environment and destroy the production equipment so that their presence in gas stream leads to corrosion and lowering heating value. On the other hand, for reliable and optimum design of separation equipment, primarily sufficient and accurate equilibrium data of the acid gases solubility in the aqueous alkanolamines is required. In this work, the simultaneous solubility of the H2S+CO2 in the alkanolamine mixtures is measured at 343K and total pressure range of 0.1–2.1MPa. The blends are studied as the aqueous mixtures of N-methyldiethanolamine (MDEA)+2-amino-2-methyl-1-propanol (AMP)+Piperazine (Pz) and the aqueous mixtures of diisopropanolamine (DIPA), AMP and Pz. For the acid gas solubility measurements, a high pressure static apparatus is used through a volumetric method. The mass fraction of the total alkanolamine is fixed at 0.45 and the results are presented as the partial pressure of each acid gas against its loading (mole acid gas/total mole amine) and mole fraction. The influence of the AMP and Pz on the aqueous DIPA-based and MDEA-based systems are studied so that it is observed that the absorption of the CO2 in the aqueous alkanolamine enhances through separate blending of the AMP and Pz with the aqueous system of MDEA or DIPA and the absorption of the H2S reduces in both of the aqueous DIPA-based and MDEA-based systems.

Synthesis and H2 Gas-Sensing Property of ZnO Nanobelts

ZnO nanostructures have been found to be of wide and diverse applications, such as field effect transistors, dye-sensitized solar cell, photoelectric devices and gas sensors, etc. ZnO nanostructures with different dimension various morphologies, including to nanowires, nanorods, nanotubes, nanoflowers and nanobelts have successfully synthesized by means of different methods. Comparing with other nanostructures, ZnO nanobelts have specific properties. A simple and effective method for the preparation of ZnO nanobelts was introduced in this paper. By using the electrochemical oxidation and heat treatment method,a layer of ZnO nanobelts thin film was obtained on the surface of Sn. In the first, the Sn-Zn alloy films were anodized in 0.01 M·L-1 of oxalic acid solution, and then the prepared films were annealed at 500°C for 2h in air ambient. The samples were characterized by field emission scanning electron microscopy (FE-SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and X-ray diffraction (XRD). The results show that the ZnO nanobelts have a thickness of 20 nm, with widths of 200 nm and lengths of 1~5 μm. The H2 gas sensing property of the ZnO nanobelts was measured in a static apparatus at room temperature. It was found that the ZnO nanobelts exhibited excellent H2 compounds sensing property.

Vapor–Liquid Equilibria for Water + Propylene Glycols Binary Systems: Experimental Data and Regression

The vapor–liquid equilibria (VLE) data are essential for the design of distillation columns to separate propylene glycols mixtures, obtained via the hydrolysis of 1,2-epoxy propane. In this study there are reported data for four binary systems involved, such as water + propylene glycols. VLE data have been measured in the temperature range (295.15 to 460.15) K and pressure up to 34.529 kPa for the following binary systems: water +1,2-propanediol (monopropylene glycol, MPG), water +1-(2-hydroxypropoxy)propan-2-ol (dipropylene glycol, DPG), water +2-[2-(2-hydroxypropoxy)propoxy]propan-1-ol (tripropylene glycol, TPG), and water +2-(2-[2-(2-hydroxypropoxy)propoxy]propoxy)propan-1-ol (tetrapropylene glycol, TePG). The equipment used was a static apparatus built in our laboratory. The only literature data available for these systems were for the water + MPG binary system. The experimental data obtained were correlated with the NRTL model. The results showed a fairly good agreement between the model and the experimental data with a maximum deviation in composition terms of 3%.

Phase behaviour for the (carbon dioxide + 1,3-butanediol diacrylate) and (carbon dioxide + 1,3-butanediol dimethacrylate) systems at elevated pressures and temperatures

The solubility curves for the (carbon dioxide+1,3-butanediol diacrylate) and (carbon dioxide+1,3-butanediol dimethacrylate) systems at various temperatures (313.2, 333.2, 353.2, 373.2 and 393.2)K as well as pressures up to 24.9MPa were measured by static apparatus. The solubility of 1,3-butanediol di(meth)acrylate in the (carbon dioxide+1,3-butanediol di(meth)acrylate) systems increases as the temperature increases at a constant pressure. The (carbon dioxide+1,3-butanediol diacrylate) and (carbon dioxide+1,3-butanediol dimethacrylate) systems exhibit type-I phase behaviour. The experimental results for the (carbon dioxide+1,3-butanediol diacrylate) and (carbon dioxide+1,3-butanediol dimethacrylate) systems correlate with the Peng–Robinson equation of state using a van der Waals one-fluid mixing rule including two adjustable parameters (kij,ηij). The critical properties of 1,3-butanediol diacrylate and 1,3-butanediol dimethacrylate were predicted with the Joback–Lyderson method.

Phase equilibrium properties of binary mixtures containing 2,5-dimethylfuran and furfuryl alcohol or methyl isobutyl ketone at several temperatures

The (vapor+liquid) equilibria of the pure components, furfuryl alcohol, and methyl isobutyl ketone along with the binary mixtures (2,5-dimethylfuran+furfuryl alcohol), or (2,5-dimethylfuran+methyl isobutyl ketone), were investigated experimentally by means of a static apparatus at temperatures between (313 and 393)K. The vapor pressures of the pure components were correlated with the Antoine equation. The experimental results for the mixtures were reduced by the Barker method using a third-order Redlich–Kister equation. The calculated values of the excess Gibbs free energy, GE, exhibit positive deviations for all investigated temperatures and over the whole composition range. The NRTL, UNIQUAC and Modified UNIFAC (Do) models have been applied to correlate the experimental VLE results.

Measurements of Bubble Point Pressures for the Binary Mixture of Pentafluoroethane with Chloropentafluoroethane

Bubble point pressures for the binary mixture of pentafluoroethane (HFC-125) with chloropentafluoroethane (CFC-115) were measured at the temperature ranges from (243.15 to 333.15) K using a static apparatus. The uncertainties of measurements were estimated to be less than 20 mK in temperature, 1.2 kPa in pressure, and 0.001 in liquid-phase mole fraction. The experimental data were correlated with the Peng–Robinson equation of state with van der Waals mixing rules. The correlation results have a good agreement with the experimental results. The overall average absolute deviation was 0.36 % between measured pressures and calculated results from the Peng–Robinson (PR) equation of state. The interaction parameter k12 was obtained for different temperatures, and the relationship between k12 and the temperature was correlated with the deviation of ± 0.5 %. The azeotropic compositions and pressures at specified temperatures were calculated.

Inégalités de recours aux dépistages des cancers

This paper presents new experimental results for Normafluid ISO 4113. Vapor pressures of Normafluid were measured from 0.001 kPa to 27 kPa and from 273 to 463 K, using a static apparatus. The experimental vapor pressures were smoothed using the Antoine equation. Air solubility in the fuel at 288 K, 298 K and 308 K and up to 0.8 MPa was also determined. Isobaric thermal expansivitites of Normafluid were determined over the temperature range from 273.15 K to 423.15 K at pressures up to 200 MPa using scanning transitiometry; therefrom thermodynamic relations were used to obtain the isobaric specific heat capacities, specific volumes, isothermal compressibilities, isentropic compressibilities and isentropic bulk modulus over wide pressure and temperature ranges.

Measuring Motor Coordination in Mice

Mice are increasingly being used in behavioral neuroscience, largely replacing rats as the behaviorist's animal of choice. Before aspects of behavior such as emotionality or cognition can be assessed, however, it is vital to determine whether the motor capabilities of e.g. a mutant or lesioned mouse allow such an assessment. Performance on a maze task requiring strength and coordination, such as the Morris water maze, might well be impaired in a mouse by motor, rather than cognitive, impairments, so it is essential to selectively dissect the latter from the former. For example, sensorimotor impairments caused by NMDA antagonists have been shown to impair water maze performance2. Motor coordination has traditionally been assessed in mice and rats by the rotarod test, in which the animal is placed on a horizontal rod that rotates about its long axis; the animal must walk forwards to remain upright and not fall off. Both set speed and accelerating versions of the rotarod are available.The other three tests described in this article (horizontal bar, static rods and parallel bars) all measure coordination on static apparatus. The horizontal bar also requires strength for adequate performance, particularly of the forelimbs as the mouse initially grips the bar just with the front paws. Adult rats do not perform well on tests such as the static rods and parallel bars (personal observations); they appear less well coordinated than mice. I have only tested male rats, however, and male mice seem generally less well coordinated than females. Mice appear to have a higher strength:weight ratio than rats; the Latin name, Mus musculus, seems entirely appropriate. The rotarod, the variations of the foot fault test12 or the Catwalk (Noldus)15 apparatus are generally used to assess motor coordination in rats.

Measuring Motor Coordination in Mice

Mice are increasingly being used in behavioral neuroscience, largely replacing rats as the behaviorist's animal of choice. Before aspects of behavior such as emotionality or cognition can be assessed, however, it is vital to determine whether the motor capabilities of e.g. a mutant or lesioned mouse allow such an assessment. Performance on a maze task requiring strength and coordination, such as the Morris water maze, might well be impaired in a mouse by motor, rather than cognitive, impairments, so it is essential to selectively dissect the latter from the former. For example, sensorimotor impairments caused by NMDA antagonists have been shown to impair water maze performance2. Motor coordination has traditionally been assessed in mice and rats by the rotarod test, in which the animal is placed on a horizontal rod that rotates about its long axis; the animal must walk forwards to remain upright and not fall off. Both set speed and accelerating versions of the rotarod are available. The other three tests described in this article (horizontal bar, static rods and parallel bars) all measure coordination on static apparatus. The horizontal bar also requires strength for adequate performance, particularly of the forelimbs as the mouse initially grips the bar just with the front paws. Adult rats do not perform well on tests such as the static rods and parallel bars (personal observations); they appear less well coordinated than mice. I have only tested male rats, however, and male mice seem generally less well coordinated than females. Mice appear to have a higher strength:weight ratio than rats; the Latin name, Mus musculus, seems entirely appropriate. The rotarod, the variations of the foot fault test12 or the Catwalk (Noldus)15 apparatus are generally used to assess motor coordination in rats.

Measurement of Heavy Oil and Bitumen Vapor Pressure for Fluid Characterization

The prediction of heavy oil phase behavior, particularly with solvents, is sensitive to the characterization of the middle and heavy boiling point components of the oil. These components are typically characterized based on an extrapolation of distillation data. One method to test the extrapolated characterization is to model the vapor pressures of these fractions or residues containing these fractions. Unfortunately, the vapor pressures are too low to be reliably measured with conventional techniques. A new high vacuum static apparatus was designed and constructed for the measurement of vapor pressure of heavy oil and bitumen samples. The apparatus is capable of measuring pressures from 100 down to 0.1 Pa and temperatures in the range of 293.15–473.15 K. New procedures were developed to degas samples and obtain accurate vapor pressures at vacuum conditions. The apparatus was tested on n-hexadecane and naphthalene at temperatures between 303.15 and 363.15 K. The measured vapor pressures were, on average, all within 13% of the literature data. The vapor pressures of a Western Canadian bitumen sample (WC_BIT_B1) and three of its fractions were measured using the apparatus. The WC_BIT_B1 bitumen was modeled using the Advanced Peng–Robinson equation of state using a Gaussian extrapolation of its distillation curve for the maltene fraction and a Gamma molecular distribution for its asphaltene fraction. The measured vapor pressures were all predicted to within 3.5%.

Isothermal Vapor–Liquid Equilibria of n-Tetradecane + Ethyl Hexanoate, Ethyl Decanoate, and Ethyl Tetradecanoate

The vapor pressures of three binary systems, (ethyl hexanoate (1) + n-tetradecane (2)), (ethyl decanoate (1) + n-tetradecane (2)), and (ethyl tetradecanoate (1) + n-tetradecane (2)), were measured by means of a static apparatus at temperatures between (373.15 and 453.15) K. We correlated the data with the Antoine equation. The molar excess Gibbs energies GE obtained from these data by using Barker’s method were fitted to the Redlich–Kister equation. A maximum azeotropic behavior is observed for the binary mixture {ethyl decanoate (1) + n-tetradecane (2)}. Positive values of the excess Gibbs energy are obtained for all of the investigated temperatures and compositions. The data were also correlated by using Wilson equation. The predicted GE obtained by using group contribution model, UNIFAC (Gmehling version), are different to the experimental values. These deviations are more important for systems {ethyl decanoate (1) + n-tetradecane (2)} and {ethyl tetradecanoate (1) + n-tetradecane (2)}.

Bubble-point measurement for the CO2+diethylene glycol diacrylate and CO2+diethylene glycol dimethacrylate systems at high pressure

Pressure-composition isotherms are measured by using a static apparatus for the phase behavior data for the CO2+diethylene glycol diacrylate (DEGDA) and CO2+diethylene glycol dimethacrylate (DEGDMA) systems. The experiments are performed at five temperatures of (313.2 to 393.2) K and pressures up to 28.3 MPa. The solubility of CO2 for the two systems decreases as the temperature increases at a fixed pressure. The CO2+DEGDA and CO2+ DEGDMA systems exhibit type-I phase behavior. The experimental results for the CO2+DEGDA and CO2+DEGDMA systems are correlated with Peng-Robinson equation of state using a mixing rule.

Syndrome cave supérieur, diagnostic étiologique

This paper presents new experimental results for Normafluid ISO 4113. Vapor pressures of Normafluid were measured from 0.001 kPa to 27 kPa and from 273 to 463 K, using a static apparatus. The experimental vapor pressures were smoothed using the Antoine equation. Air solubility in the fuel at 288 K, 298 K and 308 K and up to 0.8 MPa was also determined. Isobaric thermal expansivitites of Normafluid were determined over the temperature range from 273.15 K to 423.15 K at pressures up to 200 MPa using scanning transitiometry; therefrom thermodynamic relations were used to obtain the isobaric specific heat capacities, specific volumes, isothermal compressibilities, isentropic compressibilities and isentropic bulk modulus over wide pressure and temperature ranges.

First Experimental Determination of the Absolute Gas-Phase Rate Coefficient for the Reaction of OH with 4-Hydroxy-2-Butanone (4H2B) at 294 K by Vapor Pressure Measurements of 4H2B

The reaction of the OH radicals with 4-hydroxy-2-butanone was investigated in the gas phase using an absolute rate method at room temperature and over the pressure range 10-330 Torr in He and air as diluent gases. The rate coefficients were measured using pulsed laser photolysis (PLP) of H(2)O(2) to produce OH and laser induced fluorescence (LIF) to measure the OH temporal profile. An average value of (4.8 ± 1.2) × 10(-12) cm(3) molecule(-1) s(-1) was obtained. The OH quantum yield following the 266 nm pulsed laser photolysis of 4-hydroxy-2-butanone was measured for the first time and found to be about 0.3%. The investigated kinetic study required accurate measurements of the vapor pressure of 4-hydroxy-2-butanone, which was measured using a static apparatus. The vapor pressure was found to range from 0.056 to 7.11 Torr between 254 and 323 K. This work provides the first absolute rate coefficients for the reaction of 4-hydroxy-2-butanone with OH and the first experimental saturated vapor pressures of the studied compound below 311 K. The obtained results are compared to those of the literature and the effects of the experimental conditions on the reactivity are examined. The calculated tropospheric lifetime obtained in this work suggests that once emitted into the atmosphere, 4H2B may contribute to the photochemical pollution in a local or regional scale.

Shear strength and pore-water pressure characteristics of sandy soil mixed with plastic fine

Recent earthquake case histories have revealed the liquefaction of mixtures of sand and fine particles during earthquakes. Different from earlier studies which placed an emphasis on characterisation of liquefaction in terms of the induced shear stress required to cause liquefaction, this study adopted a strain approach because excess pore-water pressure generation is controlled mainly by the level of induced shear strains. The current study includes the results of a set of laboratory tests carried out on sand specimens with the same relative densities and variation in the plastic fines (kaolinite or bentonite) contents ranging from 0 to either 30 % and consolidated at mean confining pressure of 100, 200 and 300 kPa using static triaxial test apparatus, in order to study the influence of fine content and other parameters on the undrained shear strength and liquefaction potential of clayey sand specimens; also, pore-water pressures in the specimens are discussed. Results of tests show that the peak strength decreases as the fines (kaolinite or bentonite) content increases up to a threshold content of fines (FCth) after which, increases in plastic fine content lead to improve the peak shear strength of specimens, and also the ultimate steady-state strength has been improved due to the increased in plastic fines content. Also, pore pressure build-up in clayey sands is generally slower than that observed in pure sand.

Effect of cosolvent on cloud-point of binary and ternary systems for the poly(4-chlorostyrene) + cosolvent mixtures in supercritical fluid solvents

Pressure-composition (P–x) isotherms were obtained for the carbon dioxide+4-chlorostyrene (4-CS) system using static apparatus at five temperatures (313.2, 333.2, 353.2, 373.2 and 393.2K) and pressure up to 23.74MPa. The experimental results for the carbon dioxide+4-CS system were modeled with the Peng–Robinson equation of state (PR EOS) using two adjustable parameters. The comparison between the experimental results and the calculated curves shows a good agreement at five temperatures. Three phases were not observed at any five temperatures in this system.The experiments were conducted to obtain cloud-point data of binary and ternary mixture for the poly(4-chlorostyrene) [P(4-CS), Mw=87,000, Mn=57,000, polydispersity=1.53]+supercritical solvents (propane, propylene, butane and 1-butene)+acetone, the P(4-CS)+supercritical solvents [butane, 1-butene and dimethyl ether (DME)]+4-CS and the P(4-CS)+supercritical solvents (butane and 1-butene)+ethanol, the P(4-CS)+supercritical solvents (propylene, 1-butene and DME) and the P(4-CS)+carbon dioxide+DME systems. High pressure phase behavior experiment for the binary and ternary mixture of the P(4-CS)+supercritical solvents+cosolvent systems is measured within a temperatures range of 332.8–494.2K and pressure up to ca. 260.0MPa. The P(4-CS)+supercritical solvents (propane, propylene and 1-butene)+acetone systems show the changes in the pressure–temperature (p–T) curve from upper critical solution temperature (UCST) region to lower critical solution temperature (LCST) region as acetone concentration increases. The phase behavior curves for the P(4-CS)+supercritical solvents (butane, 1-butene)+4-CS systems of three systems [the P(4-CS)+4-CS mixture in supercritical solvents (butane, 1-butene and DME)] exhibit UCST region with negative slopes, but in the case of the P(4-CS)+DME+4-CS system, cloud-point behavior shows LCST-type curve with a positive slope. The cloud-point behaviors for P(4-CS)+supercritical solvents (butane and 1-butene)+ethanol systems exhibit USCT-type curves with negative slopes. The P(4-CS)+carbon dioxide+xwt.% DME system shows cloud-point curves changing from UCST region to LCST region as DME concentration increases.

On the Way to Determination of the Vapor-Pressure Curve of Pure Water

The determination of the physical properties of pure water, especially the vapor-pressure curve of water, is one of the major issues identified by the Consultative Committee for Thermometry of the International Committee for Weights and Measures (CIPM) to improve the accuracy of the national references in humidity. At the present time the saturation-pressure data, corresponding to ice or liquid-vapor equilibrium, at low temperature are scarce and unreliable. This study presents new measurements of vapor and sublimation pressures of, respectively, water and ice, using a static apparatus. Prior to saturation-pressure measurements, the temperature and pressure sensors of the static apparatus were calibrated against reference gauges in use at the LNE-CETIAT laboratories. The effect of thermal transpiration has been studied. The explored temperature range lies between 250 K and 374 K, and the pressure range between 70 Pa and 10(5) Pa. An automatic data acquisition program was developed to monitor the pressure and temperature. The obtained results have been compared with available literature data. The preliminary uncertainty budget took into account several components: pressure measurements, temperature measurements, and environmental error sources such as thermal transpiration and hydrostatic correction.

Novel Single Stage Wash Sedimentator for Purification and Separation of Small Particles

AbstractThe starting point for the development of a novel process for simultaneous washing and separation of fine particles was the task of removing accompanying impurities from a crystallized plant extract and separating the crystals in a purified form. For this purpose, an innovative technical concept was developed, fundamental aspects were investigated on a laboratory scale, and the process was successfully carried out on a pilot scale in a joint project. In principle, the new method is based on a static sedimentation apparatus with integrated countercurrent washing, which operates continuously and produces a purified solid concentrate.

Thermophysical properties of Normafluid (ISO 4113) over wide pressure and temperature ranges

This paper presents new experimental results for Normafluid ISO 4113. Vapor pressures of Normafluid were measured from 0.001kPa to 27kPa and from 273 to 463K, using a static apparatus. The experimental vapor pressures were smoothed using the Antoine equation. Air solubility in the fuel at 288K, 298K and 308K and up to 0.8MPa was also determined. Isobaric thermal expansivitites of Normafluid were determined over the temperature range from 273.15K to 423.15K at pressures up to 200MPa using scanning transitiometry; therefrom thermodynamic relations were used to obtain the isobaric specific heat capacities, specific volumes, isothermal compressibilities, isentropic compressibilities and isentropic bulk modulus over wide pressure and temperature ranges.