180 research outputs found
Surface Pressure of Liquid Interfaces Laden with Micron-Sized Particles
We consider the surface pressure of a colloid-laden liquid interface. As
micron-sized particles of suitable wettability can be irreversibly bound to the
liquid interface on experimental timescales, we use the canonical ensemble to
derive an expression for the surface pressure of a colloid-laden interface. We
use this expression to show that adsorption of particles with only hard-core
interactions has a negligible effect on surface pressures from typical
Langmuir-trough measurements. Moreover, we show that Langmuir-trough
measurements cannot be used to extract typical interparticle potentials.
Finally, we argue that the dependence of measured surface pressure on surface
fraction can be explained by particle coordination number at low to
intermediate particle surface fractions. At high surface fractions, where the
particles are jammed and cannot easily rearrange, contact-line sliding and/or
deformations of the liquid interface at the length scale of the particles play
a pivotal role.Comment: 13 pages, 5 figure
Lipase-catalyzed Reactions at Interfaces of Two-phase Systems and Microemulsions
This work describes the influence of two polar lipids, Sn-1/3 and Sn-2 monopalmitin, on the activity of lipase in biphasic systems and in microemulsions. In previous communications, we have shown that Sn-2 monoglycerides can replace Sn-1,3 regiospecific lipases at the oil–water interface, causing a drastically reduced rate of lipolysis. We here demonstrate that even if the lipase is expelled from the interface, it can catalyze esterification of the Sn-2 monoglyceride with fatty acids in both macroscopic oil–water systems and in microemulsions, leading to formation of di- and triglycerides
Involking silvern voices in healthcare : transforming practice by engaging older adults in collaborative partnerships
Canada's population is aging. This growing trend will ultimately have an impact on nursing practice as older individuals continue to seek healthcare services. Nurses must be able to work in collaboration with the older population to provide quality care. This action research study explored participative healthcare from an older adult's perspective.
This study revealed that older adults prefer to be active participants in their care. The major theme that emerged was true partnership. Three sub-themes that emerged were communication, respect, and trust. These three sub-themes work in unity to contribute to a healthcare experience that exemplifies true partnerships. This study proposes a definition of true partnership as being open to and inviting mutual communication in an atmosphere that encourages equity sharing of information contributing to respect and the development of trust that results in confident collaboration in care
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