Hexagonal spiral growth in the absence of a substrate

Experiments on the formation of spiraling hexagons (350 - 1000 nm in width) from a solution of nanoparticles are presented. Transmission electron microscopy images of the reaction products of chemically synthesized cadmium nanocrystals indicate that the birth of the hexagons proceeds without assistance from static screw or edge dislocatons, that is, they spiral without constraints provided by an underlying substrate. Instead, the apparent growth mechanism relies on what we believe is a dynamical dislocation identified as a dense aggregate of small nanocrystals that straddles the spiraling hexagon at the crystal surface. This nanocrystal bundle, which we term the "feeder", also appears to release nanocrystals into the spiral during the growth process.Comment: 4 pages, 5 figure

European Union Farm Policy for Citrus, Tomatoes, and Dairy

European Union (EU) consumers pay almost twice the competitive world price for many agricultural products. Agricultural subsidies accounted for almost half of the EU's total budget (US$ 40 billion on agriculture in 2000) although agriculture represented 1.7 percent of the EU's GDP and employs 4.3% of the EU's population. Domestic policies for citrus and tomatoes include export refunds, product withdraws from the market, intervention thresholds, and direct producer aid. Domestic policies for dairy include export refunds, intervention thresholds, aid for private storage, disposal aid, and milk quotas. The EU's intentions are to enhance agricultural competitiveness by setting product intervention as "a real safety net measure, allowing EU producers to respond to market signals while protecting them from extreme price fluctuations," and promoting market oriented, sustainable agriculture by finishing the transition from product support to producer support, by introducing a "decoupled system of payments per farm" which are not connected to production. The EU wishes to allow flexibility in production, but also guarantee income stability to producers. Within the last 10 years, the EU has reduced price supports and increased direct payments to tomato, dairy, and citrus farmers to compensate them for the reductions.Agricultural and Food Policy,

Design, development and use of the finite element machine

Some of the considerations that went into the design of the Finite Element Machine, a research asynchronous parallel computer are described. The present status of the system is also discussed along with some indication of the type of results that were obtained

Development of an integrated data base for land use and water quality planning

To help understand the role played by different land resources in water quality management a computer based data system was created. The Land Resource Information System (LRIS) allows data to be readily retrieved or statistically analyzed for a variety of purposes. It is specifically formatted to perform coordination of water quality data with logy, etc. New understanding of the region gained through the use of LRIS has gone well beyond the initial purpose of assessing water quality conditions. The land use and natural features information has provided a well defined starting point for a systematic evaluation of proposed land uses, transportation, housing, and other public investments. It has laid the foundation for a comprehensive and integrated approach to many different planning and investment programs presently underway

Production mechanisms and single-spin asymmetry for kaons in high energy hadron-hadron collisions

Direct consequences on kaon production of the picture proposed in a recent Letter and subsequent publications are discussed. Further evidence supporting the proposed picture is obtained. Comparison with the data for the inclusive cross sections in unpolarized reactions is made. Quantitative results for the left-right asymmetry in single-spin processes are presented.Comment: 10 pages, 2 Postscript figure