2,246 research outputs found
Simulation of weak polyelectrolytes: A comparison between the constant pH and the reaction ensemble method
The reaction ensemble and the constant pH method are well-known chemical
equilibrium approaches to simulate protonation and deprotonation reactions in
classical molecular dynamics and Monte Carlo simulations. In this article, we
show similarity between both methods {under certain conditions}. We perform
molecular dynamics simulations of a weak polyelectrolyte in order to compare
the titration curves obtained by both approaches. Our findings reveal a good
agreement between the methods when the reaction ensemble is used to sweep the
reaction constant. Pronounced differences between the reaction ensemble and the
constant pH method can be observed for stronger acids and bases in terms of
adaptive pH values. These deviations are due to the presence of explicit
protons in the reaction ensemble method which induce a screening of
electrostatic interactions between the charged titrable groups of the
polyelectrolyte. The outcomes of our simulation hint to a better applicability
of the reaction ensemble method for systems in confined geometries and titrable
groups in polyelectrolytes with different pK values.Comment: 3 figure
Use of live freshwater zooplankton for startfeeding Atlantic salmon in net pens
The experiment was carried out 1984 in a coastal lake near
Bergen, Norway. A total of four (later doubled) groups of
Atlantic salmon (Salmo salar) fry were startfed with live zooplankton
delivered by a pump. Small fine-meshed net pens were
used. Supplemental feed were offered and promoted additional
growth, but after the startfeeding phase
Terrestrial Biomass Potentials - Food - Feed - Fuels Conciderations:Case Studies of Two Large Scale Biorefineries in Denmark
Quantitative surface topography assessment of directly compressed and roller compacted tablet cores using photometric stereo image analysis
Multivariate monitoring of anaerobic co-digestion:On the way towards realisation of inline NIRS in large-scale agricultural biomass conversion facilities
- …