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All Outputs (14)

The Effects of morpholine pre-treated and carboxymethylated cellulose nanofibrils on the properties of alginate-based hydrogels (2018)
Journal Article
Onyianta, A. J., Castellano, M., Dorris, M., Williams, R. L., & Vicini, S. (2018). The Effects of morpholine pre-treated and carboxymethylated cellulose nanofibrils on the properties of alginate-based hydrogels. Carbohydrate Polymers, 198, 320-327. https://doi.org/10.1016/j.carbpol.2018.06.084

The effects of varying percentage loadings of morpholine pre-treated cellulose nanofibrils (MCNF) and carboxymethylated cellulose nanofibrils (CMCNF) on the aqueous swelling, compressive modulus and viscoelastic properties of calcium-ion-crosslinked... Read More about The Effects of morpholine pre-treated and carboxymethylated cellulose nanofibrils on the properties of alginate-based hydrogels.

Second virial coefficient of rod-shaped molecules and molecular dynamics simulations of the isotropic phase (2015)
Journal Article
Heyes, D. M., Turner, P., English, R. J., Williams, R., & Brańka, A. C. (2015). Second virial coefficient of rod-shaped molecules and molecular dynamics simulations of the isotropic phase. Physical Review E, 91(4), 042134-042144. https://doi.org/10.1103/physreve.91.042134

The second virial coefficient, B 2 is computed of linear rigid rods composed of m equally spaced sites interacting with sites on other rods via the hard-sphere or Weeks-Chandler-Andersen (WCA) pair potentials. The dependence of B 2 on a wide ran... Read More about Second virial coefficient of rod-shaped molecules and molecular dynamics simulations of the isotropic phase.

Assessment of errors induced by the anomalous dispersion of high frequency shear waves in rheometrical measurements on gelling systems (2004)
Journal Article
Jones, R., Ravji, S., Hawkins, K., Al-Hussany, A., Williams, P., & Williams, R. (2004). Assessment of errors induced by the anomalous dispersion of high frequency shear waves in rheometrical measurements on gelling systems. Journal of Non-Newtonian Fluid Mechanics, 124(1-3), 11-24. https://doi.org/10.1016/j.jnnfm.2004.07.007

The principal objectives of the work reported in this paper were two-fold. Firstly, to assess, by means of the numerical simulation of transverse wave propagation within a linear viscoelastic medium, the degree to which wavegroup propagation involvin... Read More about Assessment of errors induced by the anomalous dispersion of high frequency shear waves in rheometrical measurements on gelling systems.

Cavitation Properties of Oils Under Dynamic Stressing by Tension (2004)
Journal Article
Williams, P. R., & Williams, R. L. (2004). Cavitation Properties of Oils Under Dynamic Stressing by Tension. Journal of Fluids Engineering, 127(2), 282. https://doi.org/10.1115/1.1881692

We report measurements of the effective tensile strength FcFc of commercial “multigrade” oils (in the SAE viscosity grades 5W-30 and 10W-40) over a range of temperatures TT, which are representative of those encountered under their normal operating c... Read More about Cavitation Properties of Oils Under Dynamic Stressing by Tension.

Cavitation and the tensile strength of liquids under dynamic stressing (2004)
Journal Article
Williams, P. R., & Williams, R. L. (2004). Cavitation and the tensile strength of liquids under dynamic stressing. Molecular Physics, 102(19-20), 2091-2102. https://doi.org/10.1080/00268970412331292786

This paper discusses the differences between the results of various measurements of the effective tensile strength (F c ) of liquids in experiments involving a pulse of tension (‘negative pressure’) created by the reflection of a pressure pulse at a... Read More about Cavitation and the tensile strength of liquids under dynamic stressing.

Rheology of multigrade engine oils in high deformation rate extensional flows (2004)
Journal Article
Barrow, M. S., Brown, S. W. J., Cordy, S., Williams, P. R., & Williams, R. L. (2004). Rheology of multigrade engine oils in high deformation rate extensional flows. International Journal of Engine Research, 5(4), 349-364. https://doi.org/10.1243/146808704323224240

An experimental study is reported of liquid jets formed by the collapse of bubbles under cavitation-generated pressure waves. The results reveal that jets formed from samples of commercial multigrade engine oils experience an extensional flow which i... Read More about Rheology of multigrade engine oils in high deformation rate extensional flows.

Rheology of Dilute Polymer Solutions and Engine Lubricants in High Deformation Rate Extensional Flows Produced by Bubble Collapse (2004)
Journal Article
Barrow, M. S., Brown, S. W. J., Cordy, S., Williams, P. R., & Williams, R. L. (2004). Rheology of Dilute Polymer Solutions and Engine Lubricants in High Deformation Rate Extensional Flows Produced by Bubble Collapse. Journal of Fluids Engineering, 126(2), 162. https://doi.org/10.1115/1.1667889

We report a study of liquid jets formed by the collapse of bubbles under cavitationgenerated pressure waves. Such jets involve an extensional flow which is characterized by high rates of extension, the latter being relevant to considerations of the f... Read More about Rheology of Dilute Polymer Solutions and Engine Lubricants in High Deformation Rate Extensional Flows Produced by Bubble Collapse.

Measurements of the cavitation threshold of multigrade engine oils under dynamic stressing by pulses of negative pressure (2003)
Journal Article
Williams, P. R., & Williams, R. L. (2003). Measurements of the cavitation threshold of multigrade engine oils under dynamic stressing by pulses of negative pressure. International Journal of Engine Research, 4(4), 269-282. https://doi.org/10.1243/146808703322743886

This paper reports the first measurements of the effective tensile strength (or ‘cavitation threshold’) Fc, of degassed samples of a commercial multigrade engine oil over a range of temperatures, T, which are representative of those encountered under... Read More about Measurements of the cavitation threshold of multigrade engine oils under dynamic stressing by pulses of negative pressure.

Measurements of the Cavitation Threshold of Liquids Under Dynamic Stressing by Pulses of Tension (2002)
Conference Proceeding
Williams, P. R. W., & Williams, R. (2002). Measurements of the Cavitation Threshold of Liquids Under Dynamic Stressing by Pulses of Tension. In A. Imre, H. Maris, & P. Williams (Eds.), Liquids Under Negative Pressure: Proceedings of the NATO Advanced Research Workshop on Liquids Under Negative Pressure (285-300). https://doi.org/10.1007/978-94-010-0498-5_24

This paper addresses discrepancies between the results of different measurements of the effective tensile strength F(F c ) of liquids, in experiments in which a pulse of tension (or ’negative pressure’) is created by the reflection of a pressure puls... Read More about Measurements of the Cavitation Threshold of Liquids Under Dynamic Stressing by Pulses of Tension.

New techniques in sol–gel characterisation – mechanical measurements and fractal characteristics (2001)
Journal Article
Williams, P., Williams, R. L., Jones, R., Al-Hussany, A., & Ravji, S. (2001). New techniques in sol–gel characterisation – mechanical measurements and fractal characteristics. Journal of Non-Crystalline Solids, 293-295, 731-745. https://doi.org/10.1016/S0022-3093%2801%2900852-3

We report theoretical and experimental work which demonstrates how the viscoelastic dispersion of shear waves may be exploited in studies of the rheological properties of systems such as `critical-gels' – systems at the gel point. At the gel point a... Read More about New techniques in sol–gel characterisation – mechanical measurements and fractal characteristics.

On anomalously low values of the tensile strength of water (2000)
Journal Article
Williams, P. R., & Williams, R. L. (2000). On anomalously low values of the tensile strength of water. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 456, 1321-1332. https://doi.org/10.1098/rspa.2000.0564

We provide an explanation for the anomalously low values of liquid tensile strength recorded in some experiments involving the reflection of a pressure pulse (as tension) at the free surface of a column of water, or at a flexible membrane. The presen... Read More about On anomalously low values of the tensile strength of water.

Shear wave dispersion in mechanically self-similar gel networks (1998)
Journal Article
Williams, P. R., & Williams, R. L. (1998). Shear wave dispersion in mechanically self-similar gel networks. Journal of Physics D: Applied Physics, 31(9), 1083

A study of viscoelastic shear wave dispersion in a simulated gelation process involving mechanically self-similar nodal networks is reported. The network formed at the gel point (the infinite network cluster, or `critical gel') shares a common struct... Read More about Shear wave dispersion in mechanically self-similar gel networks.

Rheometrical aspects of the viscoelastic dispersion of shear waves in gel-like mechanical networks (1998)
Journal Article
Williams, P., & Williams, R. (1998). Rheometrical aspects of the viscoelastic dispersion of shear waves in gel-like mechanical networks. Journal of Non-Newtonian Fluid Mechanics, 78(2-3), 203-225. https://doi.org/10.1016/S0377-0257%2898%2900066-4

A modified form of the Gross-Marvin ladder model is used to simulate gelation processes in which α, the viscoelastic stress relaxation exponent in the Gel Equation, can be varied in the range O

Rheological spectroscopy of concentrated colloidal dispersions (1993)
Journal Article
Williams, P., Williams, D., & Williams, R. (1993). Rheological spectroscopy of concentrated colloidal dispersions. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 77(1), 75-79. https://doi.org/10.1016/0927-7757%2893%2980101-j

A new instrument, the virtual gap rheometer (VGR) for the determination of dynamic shear moduli (and mechanical relaxation spectra therefrom) at frequencies above 100 Hz is described. Several features of the VGR which make it particularly suited to t... Read More about Rheological spectroscopy of concentrated colloidal dispersions.