Diffuse interfacial regions between oil/water microemulsions at low surfactant concentration: phase diagram, composition, and structure investigations

1987 ◽  
Vol 91 (17) ◽  
pp. 4536-4544 ◽  
Author(s):  
Cecilia M. C. Gambi ◽  
Liliane. Leger ◽  
Christiane. Taupin
Keyword(s):  
Phase Diagram ◽  
Surfactant Concentration ◽  
Phase Diagram Composition ◽  
Composition And Structure ◽  
Oil Water ◽  
Structure Investigations ◽  
Diagram Composition

scholarly journals Structure investigations of layered soil – varved clay

2016 ◽  
Vol 48 (4) ◽  
pp. 365-375 ◽  
Author(s):  
Matylda Tankiewicz
Keyword(s):  
Mechanical Behavior ◽  
Internal Structure ◽  
Strength Properties ◽  
Layered Soil ◽  
Radiographic Images ◽  
Composition And Structure ◽  
Computed Microtomography ◽  
Structure Investigations ◽  
Varved Clay

Abstract In the paper the results of laboratory investigations of structure of layered soil are presented. They focus on varved clay that is a soil composed of two alternately arranged varves with different texture and mechanical properties. An effect of such structure is an anisotropy of the material. Due to varying conditions during its formation process the soil exhibits some irregularities in composition and structure. Due to that modelling of mechanical behavior, like strength, may not provide satisfactory results. Main purpose of the examinations is an investigation of internal structure of layered soil – varved clay – in relation to its strength anisotropy and evaluation of the suitability of the use of two different techniques to assess the soil structure. Investigated material have been taken from area near city of Bełchatów in central Poland. The examinations included investigation of particle size distribution of soil and its components, identification of lamination with use of scanning electron microscope (SEM) and computed microtomography technique (μCT). First, the texture of each varve and varved clay as a composite have been estimated. Next, the investigation of surface perpendicular to the lamination have been carried out with SEM. Pictures of varves with different magnifications are presented. Also the varves arrangement and details of layers contact area are shown. Finally, investigation of internal structure of the soil have been performed by using microtomograph. The outcome is a series of radiographic images and reconstructed 3D model of tested soil. Presented results show complexity of the structure of varved clay that affect the mechanical behavior. Determination of the structure with use of presented techniques may be helpful in examination of strength properties and proper modeling of such soil.

Optimization of the Composition and Structure of Deformable Heat Resistant Aluminum Alloy

2019 ◽  
Vol 946 ◽  
pp. 156-161
Author(s):  
Ainagul Toleuova ◽  
Bakhyt Balbekova ◽  
Irina Erakhtina
Keyword(s):  
Phase Diagram ◽  
Aluminum Alloys ◽  
Computer Calculation ◽  
Corrosion Resistant ◽  
Heat Resistant ◽  
Composition And Structure ◽  
Polythermal Sections ◽  
Temperatures Of Phase Transformations ◽  
The Cost ◽  
New Generation

The necessity of finding scientifically grounded methods for the development of new heat-resistant, wear-resistant and corrosion-resistant aluminum alloys is presented in the present work. For this purpose, the analysis of modern methods for computer calculation of phase diagrams in multicomponent metal systems using the Thermo-Calc program was carried out. Therefore, a quantitative analysis of the phase diagram the Al-Cu-Mn-Zr system was carried out, as the basis of deformable high-temperature aluminum alloys. Isothermal and polythermal sections of the phase diagram were calculated in this system. The temperatures of phase transformations were calculated. The mass and volume fractions of the phases in the studied alloys were calculated. The range of concentrations and temperatures at which the maximum amount of dispersoids Al20Cu2Mn3 may be achieved, was defined. The minimum amount of Al2Cu phase is calculated, which should correspond to the best heat resistance of alloys. It is substantiated that in the alloys of a new generation of ALTEK type, the use of homogenization and quenching operations is inexpedient, which implies the possibility of a significant reduction in the cost of heat treatment in comparison with industrial alloys, such as 1201.

Composition and Structure of Si3n4 Implanted with Ti AT 900°C

1988 ◽  
Vol 100 ◽  
Author(s):  
I. L. Singer ◽  
R. G. Vardiman ◽  
C. R. Gossett
Keyword(s):  
Phase Diagram ◽  
Solid State ◽  
Ternary Phase ◽  
Ternary Phase Diagram ◽  
Nitride Layer ◽  
Solid State Reactions ◽  
Depth Profiles ◽  
High Fluences ◽  
Composition And Structure

ABSTRACTTi+ ions were implanted to high fluences (up to 5 × 1017 /cm2 ) into Si3N4 substrates heated to around 900°C. Composition vs depth profiles were obtained by RBS (in conjunction with RUMP analysis) and microstructures were examined by TEM. At a fluence of 4 × 1017 /cm2, the Si concentration was considerably reduced at the Ti peak depth but enriched near the surface. By 5 × 1017 /cm2, Si was nearly depleted from the implanted layer, leaving a Ti-rich nitride layer merging continuously into Si3N4. TEN detected TiN precipitates up to several pm in diameter, and coherent with Si3N4 crystallites. A Si-Ti-N ternary phase diagram is used to interpret the observed solid state reactions.

Mesoscopic simulation study on phase diagram of the system oil/water/aerosol OT

2002 ◽  
Vol 365 (3-4) ◽  
pp. 347-353 ◽  
Author(s):  
Shi-Ling Yuan ◽  
Zheng-Ting Cai ◽  
Gui-Ying Xu ◽  
Yuan-Sheng Jiang
Keyword(s):  
Phase Diagram ◽  
Simulation Study ◽  
Water Aerosol ◽  
Mesoscopic Simulation ◽  
Aerosol Ot ◽  
Oil Water

Phase Diagram of Bi2Sr2CaCu2O8+d Constructed on Basis of Electronic Structure Investigations

2019 ◽  
Vol 88 (6) ◽  
pp. 064711 ◽  
Author(s):  
Robert Sobota ◽  
Naoto Kubo ◽  
Masaharu Matsunami ◽  
Tsunehiro Takeuchi
Keyword(s):  
Phase Diagram ◽  
Electronic Structure ◽  
Structure Investigations

The Use of Pseudocomponents in the Representation of Phase Behavior of Surfactant Systems

1979 ◽  
Vol 19 (05) ◽  
pp. 289-300 ◽  
Author(s):  
J.E. Vinatieri ◽  
P.D. Fleming
Keyword(s):  
Phase Diagram ◽  
Phase Behavior ◽  
Oil Recovery ◽  
Dimensional Space ◽  
Multicomponent Systems ◽  
Tertiary Oil Recovery ◽  
Oil Water ◽  
Surfactant Systems ◽  
Lower Dimensional ◽  
Water Alcohol

Abstract A new method is developed to represent the phase behavior of multicomponent systems. This method uses fewer pseudocomponents than true components, but unlike conventional methods in which pseudocomponents are often chosen arbitrarily, the pseudocomponents are often chosen arbitrarily, the method uses regression analysis to find a "best" set of pseudocomponents.The method is applied to two surfactant systems of the type used for tertiary oil recovery. One system contains a crude oil (from the North Burbank Unit, Osage County, OK) and the other contains a pure hydrocarbon, 1-phenyltetradecane. For both systems the representation in terms of the pseudocomponents chosen by the regression analysis is significantly more faithful than that obtained by conventional methods.Since the considerations discussed here are general, they should be applicable to a wide range of phase studies in multicomponent systems. For example, they should be illuminating when applied to oil recovery by gas injection (carbon dioxide, natural gas, etc.), and to extraction processes, as well as to surfactant systems. Introduction Systems containing surface active agents have attracted a great deal of attention in connection with tertiary oil recovery. In many of these systems optimum oil recovery has been found to be strongly correlated with the phase behavior of these systems. To understand completely the basis for these correlations, one must be able to represent the phase behavior of systems containing surfactants adequately.Surfactant systems for tertiary oil recovery usually contain at least five components: oil, water, surfactant. cosurfactant, and electrolyte. The isothermal, isobaric phase diagram of these systems can be represented in a phase diagram of these systems can be represented in a four-dimensional space. Because physical representation (in three dimensions) of such a diagram is impossible. various techniques have been developed to attempt to represent the phase behavior in lower dimensional spaces. All these techniques correspond to projections of the original diagram onto lower dimensional spaces. Although almost unlimited methods of projection exist, only a small fraction convey useful information.Two projection schemes having some similarities but different intents and consequences are straight mathematical projection and "pseudocomponent" projection. Straight mathematical projection refers to the process of directly projecting the four-dimensional data for the entire phase diagram along some specified direction onto a three-dimensional space. All information parallel to the direction of the projection is lost. For example, if the rays of projections are parallel to the oil/water edge of the phase diagram, the resulting representation contains no information about the relative amounts of oil and water in the phases. In principle, this problem can be circumvented by generating two representations corresponding to projections of the same data along two different directions. For example. a second representation could be produced corresponding to a projection parallel to the water/alcohol edge of the phase diagram. parallel to the water/alcohol edge of the phase diagram. Although neither representation contains complete information, the pair of representations does contain all information about the system. The problem with this method is that the information is not perceived easily and, since the intent of using phase diagrams is usually to make visible a summary of the phase trends, such mathematical representations are not very useful.The second and generally more useful projection scheme uses pseudocomponents. A pseudocomponent is some mixture of pure components treated as a single component. SPEJ P. 289

Van der Waals forces in oil—water systems from the study of thin lipid films - II. The dependence of the van der Waals free energy of thinning on film composition and structure

1975 ◽  
Vol 347 (1649) ◽  
pp. 161-177 ◽  
Keyword(s):  
Free Energy ◽  
Layer Structure ◽  
Van Der Waals ◽  
Dielectric Permeability ◽  
Water Systems ◽  
Water Model ◽  
Polar Groups ◽  
Composition And Structure ◽  
Lipid Films ◽  
Oil Water

The van der Waals contribution to the free energy of thinning of lipid films has been determined for a variety of lipids, solvents and polar phases, and Hamaker coefficients have been calculated from this free energy, using the equation for a simple three layer (water–hydrocarbon–water) model. The results confirm and extend the findings presented in part I (Requena, Billett & Haydon 1975) i. e. that, for systems of comparable composition, the Hamaker coefficient approaches a constant value as the film thickness increases but that, towards smaller thicknesses, the coeffi­cient tends to rise rapidly. This latter observation is not readily accounted for in terms of the three layer structure, and experiments have been carried out in order to pinpoint the shortcomings of the model. Inter­action between the layers of lipid polar groups is shown to have been justifiably neglected, but it is inferred that small variations across the films of the dielectric permeability of the hydrocarbon may play a con­siderable part in determining the Hamaker coefficient.

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