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Contaminant Pathways — Subsurface Investigation and Monitoring Approach
Published in Christopher M. Palmer, Principles of Contaminant Hydrogeology, 2019
Solubility is the degree and ease to which the chemical or compound will dissolve in water. Solubility determines the concentration present in water and if the contaminant will interact with other chemicals and to the extent that they become molecularly or ionically dispersed in the solvent to form a true solution. The precise determination of solubility remains elusive for many contaminant compounds, and some of the aqueous solubility values are only estimates. Many environmentally sensitive compounds have very low water solubilities. Miscibility is the ability of a liquid or gas to dissolve uniformly in another liquid or gas. For example, alcohol and water are completely miscible because of their chemical similarity. Other liquids are only partially miscible or not miscible such as petroleum compounds and water. However, even low water solubilities may still greatly exceed ingestion standards for drinking water.
Thermodynamics of Polymer Mixtures
Published in Anil Kumar, Rakesh K. Gupta, Fundamentals of Polymer Engineering, 2018
In order to predict polymer–polymer miscibility, we might turn to the Flory–Huggins theory, where each lattice site has an interacting segment volume vs. Dividing both sides of Eq. (9.3.20) by the total mixture volume V and using the definition of the interaction parameter given by Eq. (9.3.18) yields () ΔGMV=kT[n1v1v1Vlnϕ1+n2v2v2Vlnϕ2]+Δezn0ϕ1ϕ2V
Properties of Working Fluids
Published in Reinhard Radermacher, Yunho Hwang, Vapor Compression Heat Pumps, 2005
Reinhard Radermacher, Yunho Hwang
The miscibility depends on the substances that are mixed, the mass fraction and temperature. Figure 2.2.1 shows the miscibility of refrigerant R134a in a specific polyol-ester lubricant. The top of the curve point C indicates the minimum temperature at which the refrigerant and lubricant are miscible in all mass fractions. In the area to the left of the curve, the mixture is refrigerant rich and miscible, while in the area right of the curve, the mixture is lubricant rich and miscible. In the area below the curve the refrigerant and lubricant are present in two liquid phases. Each phase is a homogeneous mixture of refrigerant and oil but of different mass fractions. The area enclosed by the curve through A, B and C is termed the mixing gap. Their mass fractions of two liquid phases are given for a certain temperature by the horizontal limits of the curve for example points A and B at –60°C. Thus, at –60°C, R134a and polyol-ester lubricant are miscible when the lubricant mass fraction is either less than 4%, point A, or higher than 54%, point B. However, they are not miscible when the lubricant mass fraction is between the mass fractions of points A and B.
Formulation and characterization of nanoemulsions stabilized by nonionic surfactant and their application in enhanced oil recovery
Published in Petroleum Science and Technology, 2023
Anindya Sundar Goswami, Rajvardhan Rawat, Prathibha Pillai, Rohit Kumar Saw, Dinesh Joshi, Ajay Mandal
Miscibility is the property of liquids to get dissolved into each other in order to form a homogeneous solution. The miscibility of crude oil with the nanoemulsions gives an idea of how well the crude oil would be solubilized within the pores during the actual flooding process. It is also a measure of the IFT reducing capabilities of the emulsion in contact with crude oil. The miscibility of crude oil with nanoemulsion was observed for a week after shaking and subjecting to sonic bath. Separation started within a few hours from the time of preparation, but some degree of miscibility remained even after 5 days. Since the oil is lighter that the emulsion, it separated at the top and the nanoemulsion at the bottom gradually became lighter. In reservoir conditions, there would be constant mixing of the oil and nanoemulsion slug, which would result in a better miscibility for long durations. Photographs of the mixture of nanoemulsions and crude oil at different intervals of time have been shown in Figure 9.
Structural, electronic, magnetic and thermodynamic properties of Ni1−xTixO alloys an ab initio calculation and Monte Carlo study
Published in Phase Transitions, 2018
K. Klaa, S. Labidi, R. Masrour, A. Jabar, M. Labidi, A. Amara, A. Drici, E. K. Hlil, M. Ellouze
The composition region between two binodal points is the miscibility gap. Thermodynamically unstable phases may exist as metastable if the decomposition kinetics is slow and combined with a rapid quenching. Within the miscibility gap, there also exist two inflection spinodal points. Using the x-dependent interaction parameter and the critical temperature Tc, the stable and/or metastable boundary lines are quantitatively determined. Figure 6 shows the resulting phase diagram for the alloys of interest. The alloy critical formation temperature occurs at a point where both the first and second derivatives of the free energy are zero, i.e. the plot has no curvature. The miscibility gap disappears at Tc. At the critical composition , the observed Tc is 916 K. For our phase diagram, more stable semiconductor alloys are likely to form at high temperature [39]; these results indicate that the alloys are unstable over a wide range of intermediate compositions at normal growth temperature.
A thermomechanical comparative study on carbon and boron nitride nanotube-reinforced polymer composites
Published in Mechanics of Advanced Materials and Structures, 2022
The dispersion of nanotubes in the polymer matrix is one of the most important factors that determine the reinforcing efficiency. The miscibility of two different materials can be understood through the Hildebrand solubility parameter. The two materials are more miscible when the solubility parameters are closer together [48, 49]. The solubility parameter is the square root of the cohesive energy and is defined as where c is the cohesive energy density, is the heat of vaporization, R is the gas constant, T is the temperature of the system, and Vm is the molar volume of the system.