Multi-scale coarse-graining of diblock copolymer self-assembly: from monomers to ordered micelles

Starting from a microscopic lattice model, we investigate clustering, micellization and micelle ordering in semi-dilute solutions of AB diblock copolymers in a selective solvent. To bridge the gap in length scales, from monomers to ordered micellar structures, we implement a two-step coarse graining strategy, whereby the AB copolymers are mapped onto ``ultrasoft'' dumbells with monomer-averaged effective interactions between the centres of mass of the blocks. Monte Carlo simulations of this coarse-grained model yield clear-cut evidence for self-assembly into micelles with a mean aggregation number n of roughly 100 beyond a critical concentration. At a slightly higher concentration the micelles spontaneously undergo a disorder-order transition to a cubic phase. We determine the effective potential between these micelles from first principles.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Lett

Open data and smallholder food and nutritional security

This report was commissioned CTA as a member of the GODAN initiative. It aims to provide a better understanding of the actual impact of the open data movement on the food and nutrition security of smallholders and highlight the areas of potential unfilled opportunity

Review of codes of conduct, voluntary guidelines and principles relevant for farm data sharing

Codes of conduct, voluntary guidelines, sets of principles on how to transparently govern farm data are a recent thing. While laws and regulations that govern personal data are becoming more and more common, legislation still does not cover data flows in many industries where different actors in the value chain need to share data and at the same time protect all involved from the risks of data sharing. Data in these value chains is currently governed through private data contracts or licensing agreements, which are normally very complex and on which data producers have very little negotiating power. Codes of conduct have started to emerge to fill the legislative void and to set common standards for data sharing contracts: codes provide principles that the signatories/subscribers/members agree to apply in their contracts

SHARC: Space Habitat, Assembly and Repair Center

Integrated Space Systems (ISS) has taken on the task of designing a Space Habitat, Assembly and Repair Center (SHARC) in Low Earth Orbit to meet the future needs of the space program. Our goal is to meet the general requirements given by the 1991/1992 AIAA/LORAL Team Space Design competition with an emphasis on minimizing the costs of such a design. A baseline structural configuration along with preliminary designs of the major subsystems was created. Our initial mission requirements, which were set by AIAA, were that the facility be able to: support simultaneous assembly of three major vehicles; conduct assembly operations and minimal extra vehicular activity (EVA); maintain orbit indefinitely; and assemble components 30 feet long with a 10 foot diameter in a shirtsleeve environment

Whole-family approach to agricultural market success

This brief describes how Women in Business Development Incorporated (WIBDI), a non-profit organisation in Samoa, works with farming families to produce highvalue products for local and global markets. Shifting away from a women-focused approach, WIBDI now uses an approach that involves the whole family, keeping all family members on board. It has also invested in digital applications and resources to increase the efficiency of operations, profile the producers and their products, and facilitate engagement with markets and customers