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Recent advances in milli- and microscale fluidics have led to the miniaturization of liquid-liquid extraction systems. Carryover is a primary mode of failure in these systems, where unwanted liquid appears at the outlet of the opposite phase. Active monitoring of carryover is key to realizing automation and deployment of such fluidic technologies. In this paper, we present an inexpensive sensor and simple methods of analysis to quantify carryover. The sensor measures the volume composition of immiscible liquids using off-the-shelf tubing, a LED light source, a linear CMOS sensor, and shadowgraphy. Beam4 optical modeling is included to provide insight into this sensor's optical behavior. We report measurements of single and two-phase flows and explore average pixel ratio (signal:background) and menisci counting analyses. As an added benefit, we use average pixel ratio to identify bulk liquids and their constituents, specifically toluene, water, and 0–50 wt% sucrose in water. [Display omitted] • Immiscible liquids appear in slugflow in narrow tubing (entrainment). • LED illumination casts "shadows" of droplet menisci onto linear CMOS detector. • Pixel intensity and/or droplet menisci count reveal liquid-liquid volume composition and onset of carryover. • Full range volume composition measurement achievable. • Beam4 optical model confirms intensity measurements, qualifies menisci behavior. [ABSTRACT FROM AUTHOR]

As a continuation of our previous studies of light lanthanides (La, Ce, Pr, and Nd) with (Pyrazol-1-yl)acetic acid (L), we reacted L with the heavier lanthanides in aqueous solution at pH 5 and synthesized lanthanide complexes of the general formula [Ln(L)3(H2O)2]·H2O (Ln=Eu, 1; Gd, 2; Dy, 3; Ho, 4; Er, 5; Yb, 6; Lu, 7) and [HoL(NO3)2(H2O)3] (8). All complexes were characterized by single crystal X-ray diffraction analysis revealing one-dimensional chain formations. Three distinct crystallographic structures are governed by the different coordination modes of the carboxylate groups in L: terminal bidentate, bridging bidentate and tridentate coordination in 1–3, terminal and bridging bidentate coordination in 4–7, and bridging bidentate coordination in 8. The solid state UV–Vis–NIR diffuse reflectance spectra and the solution UV–Vis–NIR absorption spectra differ, suggesting different coordination environments in solution and solid state. The coordination-induced shifts of the 13C NMR signals for [Lu(L)3(H2O)2]·H2O (7) in D2O show that the carboxylate groups of the ligand are coordinated with the Lu(III) ion in solution. [ABSTRACT FROM AUTHOR]

[Display omitted] • A study on ultrasonic wave propagation in liquid filled containers is shown. • A unique non-invasive liquid level detection method is developed and demonstrated. • The developed method has the potential for universal applicability. Techniques to measure liquid level in containers and vessels non-invasively are of great interest for the manufacturing, chemical industries, and energy sectors. Most commercial solutions use invasive techniques, which are not always practical and can lead to unsafe conditions when measuring devices encounter high pressures or hazardous chemical contents. In this study, a portable, non-invasive acoustic liquid level identification technique is developed. The technique relies on comprehensive analysis of acoustic guided wave modes in the container walls and their coupling to liquid contents to determine the optimal sensor separation distance and excitation signal characteristics, resulting in liquid level determination with high accuracy and precision. First, dispersion characteristics of guided wave propagation in container walls in contact with a liquid boundary are studied in detail. Based on the dispersion analysis a general-purpose short-range liquid level detection methodology is developed. The developed methodology is then validated using numerical wave propagation simulations and experiments on various metal containers with different physical characteristics, illustrating the versatility of the method. Compared to existing techniques, which are optimized for specific applications, the proposed method, due to its short range and non-invasive nature, has the potential for universal applicability on virtually any container, irrespective of its shape, size, wall-thickness, and whether it has any internal components. [ABSTRACT FROM AUTHOR]