Colección ex situ de plantas vivas de especies nativas del orden Zingiberales del Sur del Lago de Maracaibo, Venezuela

The loss of biological diversity in the Southern Part of the Lago de Maracaibo, Venezuela, due to cattle rising, has caused the extinction of 97 % of the original the Zingiberales order for purpose of study and conservation, because of the importance of this subject in the tropical floriculture (cut flowers, foliage and landscaping). The use of the biological diversity and the new native species flora could promote the efficient and sustainable use of the natural resources of the Southern Part of the Lago de Maracaibo. For that reason, it was collected 18 samples among varieties and species which passed the nursery stage, and then they were transplanted in the field after three months, besides, it was accounted the humidity and light conditions they had in their natural ecosystem; as a result plants showed favorable adaptability indicators.

Ordered mesoporous titanium oxide for thin film microbatteries with enhanced lithium storage

A 3D mesoporous TiO2 material with well-developed mesostructure is prepared in the form of a binder-free thin (100 nm) film and studied as potential candidate for the negative electrode in lithium microbatteries. By appropriate thermal treatments, the selected crystal structure (anatase, rutile, or amorphous), and micro-/mesostructure of the materials was obtained. The effects of voltage window and prelithiation treatment improved first cycle reversibility up to 86% and capacity retention of 90% over 100 cycles. After a prolonged intercalation of lithium ions in ordered mesoporous TiO2 appeared small particles assigned to Li2Ti2O4 with cubic structure as observed from ex-situ TEM micrographs. This study highlights the flexibility of the potential window to which the electrode can operate. Maximum capacity values over 100 cycles of 470 μA h cm−2 μm−1 and 177 μA h cm−2 μm−1 are obtained for voltage ranges of 0.1–2.6 V and 1.0–2.6 V, respectively. The observed values are between 6 and 2 times higher than those obtained for films with 600 nm (80 μA h cm−2 μm−1) and 900 nm (92 μA h cm−2 μm−1) lengths. This indicates that 100 nm thin TiO2 films with high accessibility show finite-length type diffusion which is interesting for this particular application.