Adiabatic compressibility of biphasic salt melts

The adiabatic compressibility along the two-phase saturation line was calculated for nine molten immiscible mixtures, namely, LiF + KBr, LiF + CsCl, LiF + RbBr, LiF + KI, LiF + CsBr, LiF + RbI, LiF + CsI, LiCl + AgBr, and NaCl + AgI, using experimental data on the sound velocity and density. It is shown that the ratio of compressibility of the equilibrium phases depends significantly on the sizes of the mixed ions. The dependence of the changes in compressibility in the distance and in the vicinity of the critical mixing point on the characteristics of the chemical bond between the ions is discussed.

Performance of a novel green scale inhibitor

Many aspects of oilfield scale inhibition with green scale inhibi-tors (SIs) have remained untouched. For instance, the discharge of large amounts of produced water containing various types of hazardous chemi-cals, such as SIs into the environment has become a major concern. In-stead, environmental regulators encourage operators to look for greener SIs. In this study, the performance of a green SI was investigated using PHREEQC simulation. For a specific case study, two brines are considered to mix incompatibly to estimate the critical mixing ratio that has the high-est tendency to scaling. Subsequently, for 50/50 mixing ratio as the critical value, theoptimal dosage of SI and its performance in the presence of two different rocks were investigated such that 450 mg/L SI would be consi-dered as optimal value. Moreover, the simulated results show that more SI adsorption on calcite would be predicted, compared to dolomite.

Detecting changes at the leading edge of an interface between oceanic water layers

Many physical phenomena in the ocean involve interactions between water masses of different temperatures and salinities at boundaries. Of particular interest is the characterisation of finescale structure at the marginal interaction zones of these boundaries, where the structure is either destroyed by mixing or formed by stratification. Using high-resolution seismic reflection imaging, we present observations of temporal changes at the leading edge of an interface between sub-thermocline layers in the Panama Basin. By studying time-lapse images of a seismic reflector between two water boundaries with subtle differences, we provide empirical constraints on how stratified layers evolve. The leading edge of this reflector, which is characterised by a gradual lateral decrease in vertical temperature contrast ($$|\Delta T|$$ ∣ Δ T ∣ ), increases in length over ~3 days coupled with an increase in $$|\Delta T|$$ ∣ Δ T ∣ . A critical mixing state, in which turbulent diffusion is gradually replaced by double-diffusion as the dominant mixing process, is thus revealed.

A General Description of Entrainment in Buoyant Cloudy Plumes Including the Effects of Mixing-Induced Evaporation

In this work, the steady-state one-dimensional axisymmetric plume theory is revisited and generalized to include the effects of nonhomogeneous updraft velocity and buoyancy profiles across the plume, environmental shear, and, more importantly, evaporative cooling resulting from the mixing between cloudy air and the dry environment. Based on an energy consistency argument, a method is proposed to derive a relationship for the fractional lateral mixing rate (which may here be positive or negative) from the plume’s integral equations, as well as a set of equations for the equivalent plume properties, both of which maintain a high degree of generality by incorporating effects of environmental shear and inhomogeneous radial distributions. In the absence of wind shear, a simpler entrainment-rate closure is proposed, which is then further constrained by systematically varying the plume and environmental conditions and allowing evaporative cooling to occur. The fractional mixing rate is shown to be strongly correlated with the plume buoyancy and, to a lesser extent, to the critical mixing fraction (i.e., the fraction of dry air that needs to be mixed with cloudy air to make the mixture neutrally buoyant). Quantitative estimates of this dependency are given to facilitate implementations of the new model in convection parameterizations. Analyzing the proposed closure suggests that it could capture features observed in recent high-resolution simulations and that it is consistent with the buoyancy-sorting concept. The results therefore support recent findings concerning the parameterization of entrainment for moist atmospheric convection.

Analysis of Synthesis Mechanism of Gold Nanoparticles Using Glass Microfluidics

According to LaMer diagram, a clearly separate of nucleation and grows step is required to synthesis of monodisperse nanoparticles. However, a critical mixing time Tc until the growth process is started, is not clear experimentally. In this paper, we prepared gold nanoparticles (GNPs) by liquid-phase reduction using citric acid on microfluidics with different flow rates. From relationship of the diameter of the prepared nanoparticle and the mixing time, Tc for the preparation of monodisperse GNPs was found for the first time.

Determination of the critical mixing intensity for secondary nucleation of paracetamol in an oscillatory flow crystallizer

The critical mixing intensity for secondary nucleation of paracetamol was determined in an oscillatory flow crystallizer for the first time.

Hydraulic Conductivity Variation of Coarse-Fine Soil Mixture upon Mixing Ratio

This paper presents the theoretical and experimental investigations of the hydraulic conductivity variation of the soil mixture that contains two distinct particle size distributions, coarse and fine soils. A new model for the hydraulic conductivity is introduced that focuses on the relationship between the coarse-fine soil mixing ratio and the hydraulic conductivity of the mixture. For the model verification, permeability tests were conducted. The glass beads and quality-controlled standard sand and soils obtained from fields were used for the specimen. The experiment results showed that the hydraulic conductivity of the soil mixture strongly depends on the mixing ratio. As the amount of the coarse soil contained in the fine soil increased, the hydraulic conductivity of the mixture decreased from that for the fine soil until the critical mixing ratio. This ratio is defined as the fine soils perfectly fill the voids between the coarse soils without remains. When the ratio is greater than the critical mixing ratio, the hydraulic conductivity is drastically increased with the mixing ratio up to that of the coarse soil. The comparison between the computed values and the test results shows that the introduced model successfully describes the measurements.

Density and Adiabatic Compressibility of the Immiscible Molten AgBr+LiCl Mixture

The adiabatic compressibility, β, of the immiscible liquid mixture 0.52 LiCl+0.48 AgBr (the top of the miscibility gap) was experimentally investigated in the temperature range from the melting point to the critical mixing temperature using the sound velocity values, u, measured by the pulse method, and the density quantities, ρ, which were determined using the hydrostatic weight procedure based on the relationship β=u− 2ρ− 1. It is shown that the coefficients of the temperature dependencies for the compressibility and density of the upper and lower equilibrium phases have opposite signs because of the superposition of the intensity of the thermal motion of the ions and the change in the composition of the phases. The differences, ∆β and ∆ρ, in the magnitudes of the compressibility and density for the equilibrium phases decrease with temperature elevation. The temperature dependencies of the compressibility and density difference are described using the empirical equations ∆β≈(Tc–T)0.438 and ∆ρ≈(Tc–T)0.439.