2,630 research outputs found
Model charged cylindrical nanopore in a colloidal dispersion: charge reversal, overcharging and double overcharging
Using the hypernetted-chain/mean spherical approximation (HNC/MSA) integral
equations we study the electrical double layer inside and outside a model
charged cylindrical vesicle (nanopore) immersed into a primitive model
macroions solution, so that the macroions are only present outside the
nanopore, i.e., the vesicle wall is impermeable only to the external macroions.
We calculate the ionic and local linear charge density profiles inside and
outside the vesicle, and find that the correlation between the inside and
outside ionic distributions causes the phenomena of overcharging (also referred
to as surface charge amplification) and/or charge reversal. This is the first
time overcharging is predicted in an electrical double layer of cylindrical
geometry. We also report the new phenomenon of double overcharging. The present
results can be of consequence for relevant systems in physical-chemistry,
energy storage and biology, e.g., nanofilters, capacitors and cell membranes.Comment: 10 pages, 4 figure
New financing trends in Latin America : an overview of selected issues and policy challenges
This article summarizes a 2007 conference that explored the nature and implications of major transformations in Latin American financial markets, such as the shift from cross-border to domestic financing and the development of domestic bond markets.Finance ; Economic policy ; Latin America
Multilevel governance challenges in transitioning towards a national approach for REDD+:Evidence from 23 subnational REDD+ initiatives
Although REDD+ was conceived as a national approach to reducing emissions from deforestation and forest degradation, many of the early advances have been at the subnational level. It is critical to link these subnational efforts to emerging national REDD+ frameworks, including with respect to finance and benefit distribution, setting reference levels, measurement, reporting and verification (MRV), land policy and safeguards. We use evidence from interviews with proponents from 23 subnational REDD+ initiatives in six countries to characterize the multilevel governance challenges for REDD+. We analyse the differences in perceived challenges between subnational jurisdictional programs and project-based initiatives, and then analyse proponents’ perceptions of the relationship between government policies at multiple levels and these REDD+ initiatives. We find important multilevel governance challenges related to vertical coordination and information sharing and horizontal and inter-sectoral tensions, as well as concerns over accountability, equity and justice. Though the shift to a nested, jurisdictional or national REDD+ is sometimes approached as a technical design issue, this must be accompanied by an understanding of the interests and power relations among actors at different levels. We outline challenges and suggest priority areas for future research and policy, as countries move towards a national REDD+ system
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