Illustrating the effect of viscoelastic additives on cavitation and turbulence with X-ray imaging.

The effect of viscoelastic additives on the topology and dynamics of the two-phase flow arising within an axisymmetric orifice with a flow path constriction along its main axis has been investigated employing high-flux synchrotron radiation. X-ray Phase Contrast Imaging (XPCI) has been conducted to visualise the cavitating flow of different types of diesel fuel within the orifice. An additised blend containing Quaternary Ammonium Salt (QAS) additives with a concentration of 500 ppm has been comparatively examined against a pure (base) diesel compound.

Turbulence and Cavitation Suppression by Quaternary Ammonium Salt Additives.

We identify the physical mechanism through which newly developed quaternary ammonium salt (QAS) deposit control additives (DCAs) affect the rheological properties of cavitating turbulent flows, resulting in an increase in the volumetric efficiency of clean injectors fuelled with diesel or biodiesel fuels. Quaternary ammonium surfactants with appropriate counterions can be very effective in reducing the turbulent drag in aqueous solutions, however, less is known about the effect of such surfactants in oil-based solvents or in cavitating flow conditions. Small-angle neutron scattering (SANS) investigations show that in traditional DCA fuel compositions only reverse spherical micelles form, whereas reverse cylindrical micelles are detected by blending the fuel with the QAS additive.

Effectiveness of Shared Medical Appointments Targeting the Triple Aim Among Patients With Overweight, Obesity, or Diabetes.

Background: Obesity and diabetes are epidemic in the United States, with many treatment options having limited long-term efficacy. A possible effective medical management tool is the shared medical appointment (SMA), which offers an efficient and cost-effective approach to behavior change and aligns with the Triple Aim (reduce costs, improve population health, and improve patient care experience) set forth by the Institute for Healthcare Improvement.

Objectives: To assess the effectiveness of SMAs to achieve the Triple Aim and to improve the management of overweight/obesity or diabetes.

How polymer additives reduce the pour point of hydrocarbon solvents containing wax crystals.

We have investigated how four different pour point depressant (PPD) polymers affect the pour point transition in mixtures of a single pure wax in a solvent. We used either n-eicosane (C20), CH3(CH2)18CH3, n-tetracosane (C24), CH3(CH2)22CH3 or n-hexatriacontane (C36), CH3(CH2)34CH3 as the wax component with either n-heptane or toluene as the solvent component. For all wax-solvent combinations, the measured variation of wax solubility with temperature is well predicted by ideal solution theory.

Universal surfactant for water, oils, and CO2.

A trichain anionic surfactant sodium 1,4-bis(neopentyloxy)-3-(neopentyloxycarbonyl)-1,4-dioxobutane-2-sulfonate (TC14) is shown to aggregate in three different types of solvent: water, heptane, and liquid CO(2). Small-angle neutron scattering (SANS) has been used to characterize the surfactant aggregates in water, heptane, and dense CO(2). Surface tension measurements, and analyses, show that the addition of a third branched chain to the surfactant structural template is critical for sufficiently lowering the surface energy, tipping the balance between a CO(2)-incompatible surfactant (AOT) and CO(2)-philic compounds that will aggregate to form micelles in dense CO(2) (TC14).