Essentials of Nutrition (Sherman, H. C.; Lanford, C. S.)

Pentacyclic triterpene synthesis. 6. Synthesis of a bicyclic intermediate corresponding to rings D and E of .beta.-amyrin

“…2 In this paper, we report the synthesis of allylic bromide 2, a synthon for rings D and E of P-amyrin.…”

Polymer and Particle Dynamics and Assembly in Varied Hydrodynamic Fields

“…Many studies have explored the impact of the polymer chain on suppression or enhancement of local hydrodynamic instabilities, such as those observed in Taylor–Couette flow, toward quantification of the mechanism of turbulent feature suppression, and optimization of the molecular architecture of a polymer for a given flow. A recent review highlights the broad applications and potential importance of Taylor–Couette flow to soft matter science, referring to the geometry as the “hydrogen atom of fluid dynamics.” In Taylor–Couette flow, or flow between concentric, rotating cylinders (Figure ), as the angular velocities of the inner and outer cylinders are varied, a rich cascade of distinct steady flow patterns of varied complexity can be accessed between unidirectional shear flow and fully developed turbulent flow.…”

“…Re i –Re o stability map for a) Newtonian ( El = 0), b) weakly elastic ( El = 0.023), and c) moderately elastic ( El ≈ 0.1–0.2) solutions, found by increasing Re i at a critically slow rate in a Taylor–Couette geometry, while holding Re o constant. Reproduced with permission . Copyright 2013, American Institute of Physics.…”

“…It is worth noting that in addition to El , the equilibrium flow states in viscoelastic Taylor–Couette flow depend on the ratio of polymer and solvent contributions to the viscosity, η p / η s , the shear rate dependence of viscosity, shear thinning index, n , and other non‐Newtonian material coefficients such as the first and second normal stress coefficients, Ψ 1 and Ψ 2 . Thus, the critical condition for each flow state Re c depends not only on η, Γ, and Re o , but also, potentially, on El , η p / η s , Ψ 2 /Ψ 1 , n , etc . There is a rich history of studies of non‐Newtonian fluids in Taylor–Couette flows, ranging from the weakly elastic limit ( El << 1) [8,18–20] to the purely elastic limit ( El >> 1).…”

“…There is a rich history of studies of non‐Newtonian fluids in Taylor–Couette flows, ranging from the weakly elastic limit ( El << 1) [8,18–20] to the purely elastic limit ( El >> 1). [17,21–23] While experimental studies in the weakly to moderately elastic 0 < El < 1 regime have covered a variety of polymer types, and η p / η s , Ψ 2 /Ψ 1 , n , the viscoelastic Taylor–Couette problem still remains largely under characterized.…”