Optimization of Alumina and Aluminosilicate Aerogel Structure for High-Temperature Performance

Alumina and aluminosilicate aerogels offer potential for use at temperatures above 700°C, where silica aerogels begin to sinter. Stability of alumina and aluminosilicate pore structures at high temperatures is governed by the starting aerogel structure, which, in turn is controlled by the synthesis route. Structure, morphology, and crystallization behavior are compared for aerogels synthesized from AlCl₃ and propylene oxide with those synthesized from a variety of boehmite precursors. The aerogels possessing a crystalline boehmite structure in the as-synthesized condition retained mesoporous structures to temperatures of 1200°C, while the AlCl₃-derived aerogels, although exhibiting higher as-synthesized surface areas, crystallized and densified at 980–1005°C.     

Plant Growth-Defense Trade-Offs: Molecular Processes Leading to Physiological Changes

In order to survive in a hostile habitat, plants have to manage the available resources to reach a delicate balance between development and defense processes, setting up what plant scientists call a trade-off. Most of these processes are basically responses to stimuli sensed by plant cell receptors and are influenced by the environmental features, which can incredibly modify such responses and even cause changes upon both molecular and phenotypic level. Therefore, significant differences can be detected between plants of the same species living in different environments. The comprehension of plant growth-defense trade-offs from the molecular basis to the phenotypic expression is one of the fundamentals for developing sustainable agriculture, so with this review we intend to contribute to the increasing of knowledge on this topic, which have a great importance for future development of agricultural crop production.     

Science map metaphors: a comparison of network versus hexmap-based visualizations

Most maps of science use a network layout; few use a landscape metaphor. Human users are trained in reading geospatial maps, yet most have a hard time reading even simple networks. Prior work using general networks has shown that map-based visualizations increase recall accuracy of data. This paper reports the result of a comparison of two comparable renderings of the UCSD map of science that are: the original network layout and a novel hexmap that uses a landscape metaphor to layout the 554 subdisciplines grouped into 13 color-coded disciplines of science. Overlaid are HITS metrics that show the impact and transformativeness of different scientific subdisciplines. Both maps support the same interactivity, including search, filter, zoom, panning, and details on demand. Users performed memorization, search, and retrieval tasks using both maps. Results did not show any significant differences in how the two maps were remembered or used by participants. We conclude with a discussion of results and planned future work.