17,857 research outputs found
Liquid–liquid equilibria for systems glycerol + sardine oil + tert-alcohols
Monoacylglycerols (MAGs) can be produced by lipase-catalyzed glycerolysis of oils and fats at atmospheric pressure and low temperature. The use of organic solvents as reaction media helps to create a homogeneous reaction system between the immiscible reactants glycerol and oil. In this work liquid–liquid equilibrium at two different temperatures (303.2 and 323.2 K) and at atmospheric pressure has been determined for two solvent-systems in the glycerolysis of fish oil (sardine oil): glycerol + sardine oil + tert-butanol and glycerol + sardine oil + tert-pentanol. From the experimental solubility (binodal) curves and tie-lines, it could be observed that the system mutual solubility does not significantly increase by increasing temperature from 303.2 to 323.2 K. The Othmer–Tobias correlation was used to analyze the consistency of the tie-line data. The experimental liquid–liquid data were correlated satisfactorily by using the NRTL model for the activity coefficient calculation.MINECO (CTQ2012-39131-C02-01) and CDTI (Ref. IDI-20111225
The Properties of Pure Liquids
By a semiempirical approach, a method is found to calculate the specific heat of a normal pure liquid at constant pressure form the specific heat of the gaseous state at the same temperature. It is also found that the coefficient of thermal expansion, the compressibility, and the velocity of sound of the liquid can be calculated accurately if the density, the molecular weight, and the normal boiling temperature of the liquid at atmospheric pressure are known. Finally, a method of computing the thermal conductivity of all liquids, except liquid metals, from compressibility and density is developed. For normal liquids, the thermal conductivity can again be determined if only the normal boiling temperature, the density, and the molecular weight are known
Liquid–liquid equilibrium for ethanolysis systems of fish oil
Enzymatic alcoholysis of fish oil can produce monoacylglycerols rich in polyunsaturated fatty acids at atmospheric pressure and low temperature. Biocatalysis in organic solvents helps to create a homogeneous reaction system for the reactants, ethanol and fish oil. This work presents liquid–liquid equilibrium at two different temperatures (303.2 K and 323.2 K) and at atmospheric pressure for two solvent-systems in the ethanolysis of fish oil: ethanol + oil + tert-pentanol and ethanol + oil + hexane. Experimental solubility (binodal) curves were obtained by the cloud point method and tie-line composition was obtained by density and high-temperature gas chromatography. The consistency of experimental tie-line data was checked by using the Othmer–Tobias equation. The experimental liquid–liquid data were correlated satisfactorily by the nonrandom two liquid model for activity coefficient calculations.MINECO (CTQ2012-39131-C02-01) and CDTI (ref. IDI-20111225
GS305+04-26:Revisiting the ISM around the CenOB1 stellar association
Massive stars deeply modify their surrounding ISM via their high throughput
of ionizing photons and their strong stellar winds. In this way they may create
large expanding structures of neutral gas. We study a new large HI shell,
labelled GS305+04-26, and its relationship with the OB association CenOB1. To
carry out this study we have used a multi-wavelenght approach. We analyze
neutral hydrogen (HI) line data retrieved from the Leiden-Argentina-Bonn (LAB)
survey, new spectroscopic optical observations obtained at CASLEO, and make use
of proper motion databases available via Internet. The analysis of the HI data
reveals a large expanding structure GS305+04-26 centered at
(l,b)=(305^{\degr}, +4^{\degr}) in the velocity range from -33 to -17 km/s.
Based on its central velocity, -26 km/s, and using standard galactic rotation
models, a distance of 2.5(+-)0.9 kpc is inferred. This structure, elliptical in
shape, has major and minor axis of 440 and 270 pc, respectively. Its expansion
velocity, total gaseous mass, and kinetic energy are ~8 km/s, (2.4(+-)0.5)x10^5
Mo, and (1.6(+-)0.4)x10^{50} erg, respectively. Several stars of the
OB-association CenOB1 are seen projected onto, and within, the boundaries of
GS305+04-26. Based on an analysis of proper motions, new members of CenOB1 are
identified. The mechanical energy injected by these stars could have been the
origin of this HI structure.Comment: 14 pages, 6 figures, A&A (in press
Test results of the Chrysler upgraded automotive gas turbine engine: Initial design
The upgraded engine as built to the original design was deficient in power and had excessive specific fuel consumption. A high instrumented version of the engine was tested to identify the sources of the engine problems. Analysis of the data shows the major problems to be low compressor and power turbine efficiency and excessive interstage duct losses. In addition, high HC and CO emission were measured at idle, and high NOx emissions at high energy speeds
Thermocapillary induced breakdown of a falling liquid film
Hydrodynamic models for effects of thermocapillary instability, film thickness, and heat flux on breakdown of falling liquid film
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