LIQUID-LIQUID EQUILIBRIUM OF THE THREE LIQUID PHASES AT EQUILIBRIUM SYSTEM WATER-PHOSFHORIC ACID-DI-ISOPROPYL ETHER AT 25 AND 40°C.

Solubility and liquid-liquid equilibrium data have been obtained for the ternary system Water-Phosproric Acid-Di-isopropyl Ether at 25 and 40^°C. This system presents a three-phase1 region at bcth temperatures. Data for the tie lines end the solubility curve in the zone above the three-phase region at 25^°C have been obtained by analyzing the phcsphcric acid and the di-isopropyl ether composition in the conjugated phases. Di-isoprcpyl ether i"as analyzed by NMR, using acetic acid as internal standard. It was impossible to apply conventional cloud point method to this zone due to the presence of an isooptic region.     

PUBIFICATION OF WET PROCESS PHOSPHOHIC ACID BY SOLVENT EXTRACTION WITH DIBUTYL ETHER. PART. I. LIQUID-LIQUID EQUILIBRIUM OF THE SYSTEM WATER-PHOSPHORIC ACID-DIBUTYL ETHER AT 25°C.

Solubility and liquid-liquid phase equilibrium data have been determinated for the ternary system water-Phosphoric Acid-Dibutyl Ether at 25°

Data for the binodal curve have been obtained by analyzing the phosphoric acid percentage in both aqueous and organic phases. The plait point composition has been calculated by the Hand, Coolidge and Sherwood methods. The phosphoric acid extraction capacity of dibutyl ether has been compared to that of several solvents previously studied in the Alicante Chemical Engineering Division, showing that dibutyl ether has a phosphoric acid extraction capacity similar to propyl-ether and lower than isoamyl alcohol.     

LIQUID-LIQUID EQUILIBRIUM OF THE WATER-PHOSPHORIC ACID-3-PENTANONE SYSTEM AT 25°C. A COMPARATIVE STUDY OF THE EXTRACTION POWER OF DIFFERENT SOLVENTS

Abstract

Solubility and liquid-liquid phase equilibrium data have been determined for the Water-Phosphoric Acid-3-Pentanone ternary system at 25 °C. Tie lines have been obtained and the plait point composition calculated. The phosphoric acid extraction capability of 3-Pentanone has been compared to that of other solvents previously studied. A systematic approach to the effects of chain length, functional group, branching and cyclation on the extraction power of the different solvents reported in the literature shows that the compatibility between solvent and phosphoric acid is higher for alcohols followed by ketones, esters and ethers. Branching and cyclation lead to a higher solubility of the acid into the organic phase, while an increase in the chain length results in a wider heterogeneous zone (i.e. in a decreasing solubility).     

LIQUID-LIQUID EQUILIBRIA FOR THE SYSTEM WATER-PHOSPHORIC ACTD-1-PENTANOL-3-PEHTAHONE AT 25°C IN THE PRESENCE OF SODIUM CHLORIDE.

A quantitative study of the effect of sodium chloride has been made on the quaternary liquid-liquid equilibria Water-Phosphoric Acid-i-Pentanol-3-Pentanone at 25°c and atmospheric pressure. Mutual solubility and tie-line data are obtained at saturation of sodium chloride in both conjugated phases. The addition of sodium chloride increases the distribution coefficient of phosphoric acid and the selectivity of extractant solvents for i-Pentanol and mixtures of 1-Pentanol and 3-Pentanone, whereas it has no significant influence when the extractant solvent is 3-Pentanone.     

EFFECT OF FIRING AT 1500°C ON THE POROSITY AND SPECIFIC GRAVITY OF QUARTZITES1

Quartzites from the various deposits being commercially utilized for the manufacture of silica brick in the United States, Canada, and Europe were tested for porosity and apparent specific gravity before and after firing at 1500 °C for 2 hours. Petrographic examination was made of several of the raw quartzites, and the differences in crystalline structure are shown by photomicrographs. The rate of conversion of the quartz. was not constant for the quartzite? reported. The porosity after firing varied from 2 to 30% and the apparent specific gravity varied from 230 to 244. A fine-grained quartzite tends to give lower porosity after firing.     

THE DIFFUSION COEFFlCIENT OF HEHEHP IN HEPTANE MEASURED BY THE MODIFIED STOKES CELL TECHNIQUE AT TEMPERATURES BETWEEN 25 AND 55°C.

The diffusion coefficient of HEHEHP in heptane has been measured by the modified Stokes cell technique at temperatures between 25 and 55^°C. The Stokes cell was calibrated by measuring acetic acid diffusion with the pH-stat technique. The average diffusion coefficient of HEHEHP in heptane was determined to be 0.97 × 10 ^?9 m²/s at 25 ^°C for HEHEHP concentrations of 0 - 0.1 kmol/m³. The diffusion coefficient did not vary significantly with HEHEHP concentration. The Wilke-Chane relationship was used to predict D values of 1.53 × lO^?9m²/s and 1.01 × 10 ^?9m²/s for the monomelic and dimeric species respectively. Comparison of the measured and predicted diffusion coefficients led to the conclusion that the HEHEHP was substantially dimenzed over the concentration range studied

An activation energy of 6.90 kJ/mol was calculated from the diffusion coefficient measurements at elevated temperature.     

STRUCTURE OF ISOTHERMAL SECTIONS OF THE DIAGRAM OF THE STATE OF THE SYSTEM ZrO2 – La2O3 – Eu2O3 AT TEMPERATURES 1500 AND 1250 °C

Using the methods of X-ray phase and microstructural analyzes, phase equilibria and structural transformations in the ZrO₂ – La₂O₃ – Eu₂O₃ system at temperatures of 1500 and 1250 ºC in the whole range of concentrations were studied. Based on the obtained data, the corresponding isothermal cross sections are constructed. It is established that the fields of solid solutions are formed in the system on the basis of cubic (F) modification with fluorite type structure, tetragonal (T) modification ZrO₂, monoclinic (B) and cubic (C) modifications Eu₂O₃, hexagonal (A) modification La₂O₃, as well as ordered phases with a structure of the pyrochlor type Ln₂Zr₂O₇ (Py). The boundaries of the phase fields and the parameters of the unit cells of the formed phases are determined. It was found that in the region with a high content of ZrO₂ solid solutions are formed on the basis of tetragonal modification of ZrO₂. The solubility of La₂O₃ in T-ZrO₂is small and is ～ 0.5% (mol.), which is confirmed by X-ray phase analysis and microstructural studies. It is established that at 1500 and 1250°C a continuous series of solid solutions is formed on the basis of an ordered phase of pyrochlor (Py) type Ln₂Zr₂O₇. With decreasing temperature, the region of homogeneity of the specified solid solution narrows. Isothermal cross sections of the state diagram of the ZrO₂-La₂O₃-Eu₂O₃ system at 1500 and 1250°C have a similar structure, although they are characterized by some differences due to the structure of the limiting binary systems. No new phases in the ternary system ZrO₂ – La₂O₃ – Eu₂O₃ were detected at the studied temperatures.     

QUATERNARY LIQUID EQULIBRIUM : WATER—PHOSPHORIC ACID—1— PENTANONE AT 25° C.

Liquid-liquid equilibrium, solubility and tie-line data, for the quaternary system Water-Phosphoric Acid-l-Pentanol-3-Pentanone, were obtained at 25°C and atmospheric pressure, using an analytical method. 1-Pentanol appears to be more effective than 3-Pentanone as extractant solvent of phosphoric acid. Advantages are not observed with the use of mixed solvents in the purification of wet process phosphoric acid by means of solvent extraction.     

SOLUBILITY OF ACETAMINOPHEN AND IBUPROFEN IN BINARY AND TERNARY MIXTURES OF POLYETHYLENE GLYCOLS 200 AND 400, PROPYLENE GLYCOL,AND WATER AT 25°C

The solubilities of acetaminophen and ibuprofen in the mixtures of propylene glycol-water, polyethylene glycols 200- and 400-propylene glycol, and polyethylene glycols 200- and 400-propylene glycol-water (122 data points) at 25°C were determined and mathematically represented by the Jouyban-Acree model. The solubilities were measured using the shake flask method, and the model was used to fit the solubility data of each drug in the solvent mixtures. The density of the solute-free solvent mixtures was measured and the density of the drug-saturated solutions was predicted. The obtained overall mean relative deviations (OMRDs) for fitting the solubility data of acetaminophen and ibuprofen in binary mixtures are 1.5% and 11.7%, respectively. The OMRDs for fitting the solubilities in ternary solvent mixtures for acetaminophen and ibuprofen are 16.3% and 42.0%, respectively, and the OMRD values for predicting all solubilities of acetaminophen and ibuprofen by these trained versions of the Jouyban-Acree model were 5.7% and 20.4%, respectively. The prediction OMRD for the density of saturated solutions was 2.5%.     

EQUILIBRIUM MOISTURE CONTENT OF DRIED BLOOD FLOUR FN THE TEMPERATURE RANGE OF 20 - 50°C

ABSTRACT

The paper presents results of water sorption tests of dried blood flour carried out tinder laboratory conditions and mathematical analyses of sorption isotherms obtained. Moisture equilibrium data were investigated at air temperatures in the range of 20–50°C and water activity ranging from 0 4 to 0 99. The experimental procedure used was a gravimetric dynamic method with continuous registration of sample weight changes. Sorption capacity decreases as temperature increases. Rehydration of the dried material results in hysteresis but this phenomenon was small. Four models of equilibrium moisture content/equilibrium relative air humidity (Chung—Pfost. Halsey. Henderson, and Oswin) were evaluated for their ability to fit data for the samples of dried blood. The modified Henderson equation was a good model for moisture adsorption and desorption of dried blood flour     

IV. PROGRESS REPORT ON INVESTIGATION OF SAGGER CLAYS. THEIR ELASTICITY,TRANSVERSE STRENGTH,AND PLASTIC FLOW AT 1000°C1

This is a Fourth Progress Report outlining results and data which are supplementary to results published in the Third Report. This Report contains values of modulus of elasticity, transverse breaking strength, and maximum fiber elongation of seventeen representative sagger clays as determined by tests at 1000°C and includes (for comparative purposes) the values of these same properties previously determined at several lower temperatures. At 1000°C the rigidity of the clays has greatly decreased and the cross-breaking strength has greatly increased when compared with values obtained at room temperatures. The pyrometric cone equivalent (P. C. E.) value of the clays appears to give the best indication of the relative plastic deflection exhibited at 1000°C.     

INFLUENCE OF SURFACTANT PROTEIN C IN β-SHEET CONFORMATION ON THE SURFACE DILATATIONAL BEHAVIOR OF PULMONARY SURFACTANT COMPONENTS SPREAD ON THE SURFACE OF A CAPTIVE BUBBLE

Surfactant protein C (SP-C) exists in α-helical and β-sheet conformation. The influence of these conformations on the surface behavior of spread layers containing dipalmytoyl phosphatodylcholine and the surfactant protein B was investigated. The β-sheet conformation of SP-C, which is formed during the preparation procedure at high lipid/protein concentrations, was confirmed by using circular dichroism (CD) and FTIR spectroscopy. Using a captive bubble device, the surface pressure/area isotherms, the surface dilatational elasticity and viscosity, and the main relaxation times of a transient stress relaxation were determined. Surface layers containing SP-C in β-sheet have no protein squeeze-out plateau. The surface dilatational elasticity is increased, which leads to a film of low compressibility. The relaxation times were increased by more than one order of magnitude, and the decays after surface compression and dilatation did not approach each other. Therefore, the surface behavior of layers containing SP-C in β-sheets remarkably differs from those containing SP-C in α-helical conformation. The presence of β–SP-C prevents the film from meeting the function of a pulmonary surfactant layer.     

CLAY SEWER PIPE MANUFACTURE.—IV. THE INFLUENCE OF DIFFERENT SALT GLAZING TEMPERATURES UPON THE COLOR AND GLOSS OF GLAZES OBTAINED ON CLAYS WITH VARYING SILICA,ALUMINA, AND IRON OXIDE CONTENTS1

Object .—A study was made of the effects of different salt glazing temperatures upon the color and brightness of salt glazes produced upon clays with varying silica, alumina, and iron oxide contents. Results .—In tests conducted in commercial kilns operating under normal conditions, it was found that increasing the salt glazing temperatures has a tendency to produce duller and darker glazes on clays containing iron oxide. The brightness of the glazes produced may be approximately represented by the following formula: -1.00×₁+ 0.376×₂ - (1.885 + 0.385(1.01253)^(T-1110))×₃= 100G ×₁, ×₂ and ×₃ represent the percentages of silica, alumina and iron oxide, respectively. T is the salt glazing temperature in °C. When G was greater than 0, the glazes were bright; when between -0.1337 and 0 they were semi matt; and when less than -0.1337 they were matt. The color obtained may be approximately represented by the following formula: 10.3x₁ - 2.65x₂+ (14.6 + 54.1 (1.0066)^(T-1110))x₃= 100°C When C was between 0 and 2, white to tan glazes were produced; when between 2 and 3.5, light brown glazes were obtained; when between 3.5 and 4.75, brown glazes were produced; when between 4.75 and 8.2, mahogany colors were obtained; and when above 8.2, dark brown to black glazes were produced. Clays containing a high iron oxide content should be salt glazed at low temperatures while clays containing a low iron oxide content should be glazed at high temperatures to produce the best glazes. Decreasing the iron oxide and alumina contents will improve the brightness of the salt glazes. High alumina clays will produce darker colors than high silica clays with the same percentage of iron oxide.     

INVESTIGATION OF METHINE TYPE DISPERSE DYES OF BENZTHIOPHEN-ONE DERIVATIVES Ⅰ. STUDY ON THE RELATION BETWEEN DYES MOLECULAR STRUCTURES AND THEIR ABSORPTION SPECTRA

A series of Methine Type Disperse Dyes of Benzthiophen-one derivatives for polyester fiber was devised and prepared. The adsorption spectra of these disperse dyes in solution were measured. The relation between the molecular structures of these dyes and their adsorption spectra was studied and discussed.     

SOLUBILITIES,DENSITIES, AND REFRACTIVE INDICES FOR THE TERNARY SYSTEMS 1,2-PROPYLENE GLYCOL + MNO3 + H2O (M = Na,K, Rb,Cs) AT 25° AND 35°C

The solubilities, densities, and refractive index data for the 1,2-propylene glycol + MNO₃ + H₂O (M = Na, K, Rb, Cs) ternary systems at 25° and 35°C were measured with mass fractions of 1,2-propylene glycol ranging from 0 to 1.0. In all cases, the presence of 1,2-propylene glycol significantly reduces the solubility of the salts in aqueous solution. The experimental data of density, refractive index, and solubility of saturated solutions for these systems were correlated using polynomial equations. Furthermore, the refractive index and density of unsaturated ternary solutions were also determined and correlated with the salt concentrations and proportions of 1,2-propylene glycol in the systems.