Self-Recoverable Mechanically Induced Instant Luminescence from Cr3+-Doped LiGa5O8

Currently, most of the mechanoluminescence (ML) phosphors strongly depend on postirradiation stimulation using ultraviolet light (denoted as “UV exposure” from hereon) to show the ML. However, only a few transition metal cations are proven to be effective luminescence centers, which hinder the development of more ML phosphors. This study reports a self-recoverable deep-red-to-near-infrared ML using Cr³⁺-doped LiGa₅O₈ phosphor with fully recoverable ML performance. The ML performance can be further optimized by tuning the trap redistributions by codoping the phosphor with Al³⁺ and Cr³⁺ cations. Theoretical calculations reveal the important role of Cr dopants in the modulation of local electronic environments for achieving the ML. Owing to the induced interelectronic levels and shallow electron trap distributions, the electron recombination efficiency is enhanced both through direct tunneling and energy transfer toward the dopant levels. Moreover, the ML of Cr³⁺-doped LiGa₅O₈ can penetrate a 2-mm-thick pork slice, showing that it can have wide-ranging in vivo applications, including the optical imaging of intracorporal stress/strain distribution and dynamics. Therefore, this work fabricates a novel ML material with self-recoverable luminescence in an extended wavelength range, increasing the number of potential ML candidates and promoting the fundamental understanding and practical applications of ML materials.     

Cell wall break down of pitanga fruit (Eugenia uniflora L.) is associated with pectic solubilisation and softening

Pitanga fruit stands out for its exotic flavour and antioxidant properties. The objective of this work was to evaluate changes in the physical, chemical and biochemical variables of red pitanga variety, in four stages of development (green, yellow, orange and red) and associate them to the cell wall break down. Analysis of pH, titratable acidity, soluble solids, firmness, soluble pectin, pectinamethylesterase (PME), polygalacturonase (PG), cell wall swelling and microstructure were performed. pH and levels of soluble solids and soluble pectin increased, in addition to the cell wall swelling and reduction of firmness, throughout the development of pitanga. From the SEM, it was possible to observe the degradation of the fruit cell wall during ripening, suggesting mainly the degradation of pectic polysaccharides, verified by the solubilisation of these substances. PG and PME enzymes were not active, which suggests that other enzymes may be associated with the cell wall break down.     

Metal loading effects on carbon-supported Pd electrocatalysts

We report for the first time effects of altering the amount of Pd supported on high-surface area carbon (Pd/C). Cyclic voltammetry in 0.1 M H₂SO₄ using Pd/C electrocatalysts with distinct metal-to-carbon ratio, Pd black and a Pd wire electrodes reveals unambiguously metal loading effects, such as a decrease in the peak potential for the reduction of palladium oxide (PdO), an increase of the charges of desorption of hydrogen, and formation/reduction of PdO with the Pd content. Such effects need to be taken into account when designing Pd-based Fuel Cells electrocatalysts.     

Brazilian hybrid electric-hydrogen fuel cell bus: Improved on-board energy management system

The present paper unveils the technology developed for a series hybrid battery-dominant electric-hydrogen fuel cell plug-in city bus. It possesses a homemade power train with three electric energy sources, which are the grid-charged energy, the one produced by the fuel cell that works at constant power and acts as a range extender and that resultant from the regeneration of kinetic energy. Emphasis was given to the design of the hybridization energy engineering that has predominance of power in batteries and predominance of energy with hydrogen. The remarkable amount of 46.6% of the total energy input reaches the motor axle for effective motion and a fuel economy of 6.7 kg H₂/100 km was achieved. A total owner cost analysis has shown that computation of capital, operational and fueling costs makes the present bus 133% more expensive than a conventional diesel powered one. Commercialization prospects, and also social and environmental impacts are analyzed.     

Efficacy of Rainfall-Runoff Models in Loose Coupling Spacial Decision Support Systems Modelbase

Water Resources Management - The need for a prognosis for water resources management in Brazil means that studies with hydrological models are required, as part of a Spatial Decision Support System...     

Tactile object recognition in early phases of grasping using underactuated robotic hands

Intelligent Service Robotics - Identifying objects during the early phases of robotic grasping in unstructured environments is a crucial step toward successful dexterous robotic manipulation....     

An image generator based on neural networks in GPU

Multimedia Tools and Applications - Existing image databases contain a few diversity of images. Likewise, there is no specific image base available in other situations, leading to the need to...