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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The relation of dynamic to equilibrium values of surfactant-induced interfacial tensions

Wingard, David Belvin 05 1900 (has links)
No description available.
2

Automation of an interfacial tensiometer

Alexander, Matthew Lucian 05 1900 (has links)
No description available.
3

The dependence of the continuous phase mass transfer coefficients on molecular diffusivity for liquid-liquid extraction in agitated vessels

Moeti, Lebone Tiisang 12 1900 (has links)
No description available.
4

Some experiments with liquid ³He-⁴He mixtures in narrow slits

Wansink, Derk Hendrik Nicolaüs, January 1900 (has links)
Proefschrift--Leiden. / "Stellingen" ([3] p.) inserted. Includes bibliographies.
5

Role of the interface in metal solvent extraction kinetics.

Chamupathi, Virittamulla Gamage. January 1987 (has links)
Interfacially active reagents are utilized in metal solvent extraction processes and it is therefore important to understand the role of the liquid-liquid interface in the study of the kinetics and equilibria of extraction. The diffusion problems encountered in the traditional apparatus were overcome by using a high speed stirring apparatus. The microporous teflon membrane phase separator permitted more accurate measurements of interfacial areas, characterization of extraction kinetics of metal chelates, and a greater understanding of the phase separation mechanism. In contrast to the neutral ligands, the anionic ligand of dithizones and substituted dithizones showed significant interfacial adsorption at the chloroform/water interface as monitored spectro-photometrically. Equilibrium studies on p-halodithizones indicated that the adsorption constant increased as the substituent was altered from chloro to bromo to iodo, and with the distribution ratio of the ligand. Kinetic studies on dithizone and p-iododithizone with Ni(II) and Zn(II) indicated that the extent of participation of the interface in solvent extraction kinetics of these metal ions is dictated by the interfacial activity of the extractant and the mechanisms of the rate limiting step in the bulk aqueous and interfacial regions.
6

Statistical evidence for competing equilibria models in the system Tri-N-Butyl phosphate-nitric acid-water-diluent

Blaylock, Charles Robert 12 1900 (has links)
No description available.
7

The design, construction, and operation of a liquid-liquid pulse extractor

Hayford, David Arthur January 1953 (has links)
Master of Science
8

The design of two apparati to measure solid-liquid and liquid-liquid equilibria data.

Tadie, Margreth. January 2010 (has links)
Two new apparati have been developed to measure solid-liquid and liquid-liquid equilibria via a synthetic visual method by determination of thermal signatures. One apparatus adopts a technique of using Peltier modules for cooling, and the other is a well-known design that uses a cryogenic fluid in a thermostatted glass cell for cooling of the sample. The Peltier design is for small sample volumes, with a 10 cm3 aluminium equilibrium cell and has a minimum operating temperature of 253.15 K. The glass design is developed to complement the Peltier and has a larger volume of 140 cm3 and a minimum operating temperature of 223.15 K. Both apparati have been semi-automated in order to increase the accuracy and improve the efficiency of data measurements. Therefore the experimenter no longer has to wait for many hours for the determination of equilibrium. This was done by incorporating software, which was specially designed for the apparati using Labview8TM, for controlling the cooling and heating rates. The uncertainty of the temperature measurements was found to be ±0.03 K for the Peltier apparatus and ±0.02 K for the Glass apparatus. Liquid-liquid equilibria data has also been measured on the Peltier apparatus, to demonstrate its versatility. This was done using a digital camera, controlled through the Labview software to identify cloud points. The results have been found to be comparable with literature values. For solid-liquid equilibria new systems of n-alkyl carboxylic acid binary mixtures have also been measured: heptanoic acid + butyric acid and heptanoic acid + hexanoic acid. These systems were measured using both apparati and both systems exhibited eutectic behaviour. All eutectic temperatures were measured on the Glass apparatus. Experimental data for these systems was modelled using the local composition models: Wilson, NRTL and UNIQUAC models. The NRTL model was found to give the best results for both systems with root mean square deviations (RMSD) of 2.16 K and 1.27 K and absolute average deviations (AAD) of 0.61 K and 0.49 K, between temperature measurements of this work and those calculated from the models, for the heptanoic acid + butyric acid and heptanoic acid + hexanoic acid systems, respectively. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2010.
9

Thermodynamics of liquid mixtures containing N-methyl-2- pyrrolidone.

Naicker, Pavanandan Kista. January 1997 (has links)
This thesis involves a study of the thermodynamics of liquid mixtures containing N-methyl-2pyrrolidone (NMP) and hydrocarbons or ethers. NMP is a polar liquid which is used in liquid extraction procedures for the separation of polar and nonpolar hydrocarbons. It was considered important enough to devote an entire thesis to the properties of NMP related to its interactions with simple hydrocarbons and ethers. The thesis consists of four parts: Part one is devoted to liquid-liquid equilibria. Experimental results at 298.2 K, are presented for the mixtures: NMP + an aromatic hydrocarbon + an n-alkane. Firstly, the effect increasing the chain length of the alkane has on the liquid-liquid equilibria was investigated, by studying mixtures of the type: an n-alkane + toluene + NMP; where the n-alkane refers to n-hexane or n-nonane or n-tetradecane or n-hexadecane. Secondly, the effect of substitution on the benzene ring on the equilibria was studied by measuring the liquid-liquid equilibria for the mixtures: n-hexadecane + an aromatic hydrocarbon + NMP; where the aromatic hydrocarbon refers to toluene or o-xylene or m-xylene or p-xylene or mesitylene or ethyl benzene. The chain length of the n-alkane had a significant effect on the liquid-liquid equilibria. Methyl substitution on the benzene ring had a small effect on the liquid-liquid equilibria. Part two is devoted to activity coefficients at infinite dilution. Experimental results at 298,15 K, determined using gas-liquid chromatography, are presented for the mixtures: NMP (solvent) + n-pentane or n-hexane or n-heptane or n-octane or cyclopentane or cyclohexane or cycloheptane or I-hexene or 1-heptene or l-octene or diethyl ether or diisopropyl ether. The magnitudes of the infinite dilution activity coefficients had the following order: n-alkanes > cycloalkanes > l-alkenes > ethers. Part three is devoted to excess molar enthalpies. Experimental results at 298.15 K are presented for the mixtures: NMP + an aromatic hydrocarbon. Here, an aromatic hydrocarbon refers to one of benzene or toluene or o-xylene or m-xylene or p-xylene or mesitylene or ethyl benzene. Isothermal flow microcalorimetry was used to determine the excess molar enthalpies. Increased methyl substitution on the' benzene ring manifests itself as a reduction in the association between NMP and the aromatic hydrocarbon. Part four is devoted to excess molar volumes. Experimental results at 298.15 K are presented for the mixtures: NMP + an aromatic hydrocarbon. Here, an aromatic hydrocarbon refers to one of benzene or toluene or o-xylene or m-xylene or p-xylene or mesitylene or ethyl benzene. Densitometry was used to determine the excess molar volumes. The excess molar volumes were negative for all the mixtures. / Thesis (M.Sc.)-University of Natal, 1997.
10

Structure and thermodynamics of associating solutions : prediction of phase equilibria

Variankaval, Narayan January 2001 (has links)
No description available.

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