Experiences in building a Grid-based platform to serve Earth observation training activities

Earth observation data processing and storing can be done nowadays only using distributed systems. Experiments dealing with a large amount of data are possible within the timeframe of a lesson and can give trainees the freedom to innovate. Following these trends and ideas, we have built a proof-of-the-concept platform, named GiSHEO, for Earth observation educational tasks. It uses Grid computing technologies to analyze and store remote sensing data, and combines them with eLearning facilities. This paper provides an overview of the GiSHEO's platform architecture and of its technical and innovative solutions.     

Cobalt nanoparticles prepared by three different methods

This work aimed to study cobalt nanoparticles (Co-NPs) preparation using three different methods in order to evaluate the effect of synthesis variables that can influence the nanoparticle size distribution and particle shape. The synthesised nanoparticles were characterised by Transmission Electron Microscopy. The first synthesis employed decomposition of Co₂(CO)₈, at high temperatures. This procedure resulted in spherical nanoparticles with low size distribution. The size of Co-NPs could be tuned by modification of precursor/surfactant, nevertheless the stirring and injection time influenced the size distribution. Using polyol process, at high temperatures, it was produced undefined-shape nanoparticles. This result suggests that the solution composition, i.e. the amount of trioctylphosphine and oleic acid was not suitable to control both size and shape of nanoparticles. Finally, the method based on reduction with NaBH₄ resulted spherical nanoparticles with tiny sizes, indicating that in this case a variation on amount of reductant would be more efficient on the particle size control than a variation in concentration of oleic acid. These results indicated that, for each method, a different variable exists for the control of the distribution size and the shape of the formed particles.     

Inertization of Coal Ashes by the Vitrification Technique: A Mixture Design Approach

This article deals with the study of the vitrification mechanism as an inertization method for coal ashes contaminated with heavy metals. Ashes from coal (thermoelectric) and wastes from mining of fluorite and feldspar and from plating were used to compose vitreous systems using a mixture design. The chemical composition of the wastes was determined by XRF and the formulations were melted at 1450°C for 2 h using 10% (mass) of Na₂CO₃ (as a fluxing agent). The glasses were poured into a mold and annealed (600°C). The characteristic temperatures were determined by thermal analysis (DTA, air, 20°C/min) and the mechanical behavior by HV. As a result, the softening temperature is strongly dependent on silica content of each glass, and the fluorite residue, being composed mainly by silica, strongly affects on the glass transition (T_g) and softening (T_s) temperatures. The hardness by micro-indentation of all glasses is mainly affected by the plating (galvanic) residue due to the high iron and zinc content of this waste.     

Liquid-liquid extraction of protease from cold-adapted yeast Rhodotorula mucilaginosa L7 using biocompatible and biodegradable aqueous two-phase systems

This work aimed to optimize the extraction of an extracellular protease produced by the cold-adapted yeast Rhodotorula mucilaginosa L7 using aqueous two-phase systems (ATPS) comprising polyethylene glycol (PEG) and sodium citrate or sodium tartrate. First, the biocompatibility of the phase forming agents was assessed. The results obtained with PEG-2000, PEG-4000, and PEG-6000 demonstrated that even at large PEG concentrations (32 wt%) the protease maintains its activity after 3 h of reaction, whereas an increase in salt concentration provokes a gradual decrease in protease stability. Subsequently, the partitioning of the protease in both types of ATPS was assessed, evaluating the effect of temperature, molecular weight, and concentration of PEG on protease purification, using two 2³-full factorial designs. The best partitioning conditions were obtained in PEG-6000/sodium tartrate-based ATPS, at 30ºC (with a yield of 81.09 ± 0.66% and a purification factor of 2.51 ± 0.03). Thus, considering the biodegradable characteristics of the system, the PEG/sodium tartrate ATPS is a viable and economic low-resolution step in protease purification, with a strong potential for future industrial application.     

trans Fatty Acids in Colostrum,Mature Milk and Diet of Lactating Adolescents

The purpose of this study was to investigate the trans fatty acids (TFA) content and distribution in colostrum, mature milk, and diet of adolescent mothers, after TFA declaration in food labels became mandatory in Brazil. Participants were healthy adolescents (n 54, 15–19 years, 1–90 days postpartum) practicing exclusive breastfeeding. Milk samples were collected 3 days after delivery (colostrum) and in the third month postpartum (mature milk) by hand expression. The fatty acid composition of the milk samples was determined by gas chromatography. TFA intake corresponded to 1.23 % of total energy value. Total 18:2 TFA accounted for less than 0.5 % of the energy intake. The amount of total 18:1 TFA (mean ± SEM) was 1.9 % ± 0.14 in colostrum and 1.5 % ± 0.2 in mature milk. The total content of n‐3 PUFA was inversely correlated with the total content of 18:1 TFA in colostrum. Both in colostrum and in mature milk, vaccenic acid (11t‐18:1) was found to be the most abundant 18:1 trans isomer, followed by elaidic acid (9t‐18:1), whereas rumenic acid (9c,11t‐18:2 CLA) was the predominant 18:2 trans isomer. In conclusion, the levels of TFA of industrial sources found in the mother's diet and breast milk (colostrum and mature milk) showed a decrease in relation to those observed in studies conducted prior to the TFA labeling resolution in Brazil. However, the current low intake levels of n‐3 LCPUFA and DHA content in the milk of lactating adolescents may be insufficient for supporting adequate neurological development of the infants.     

Structure–property relationship of sodium deoxycholate based poly(ester ether)urethane ionomers for biomedical applications

New sodium deoxycholate based poly(ester ether)urethane ionomers were prepared for the development of biomedical materials. A structure–property relationship in the tested biomaterials was established by cross‐examination of the dynamic mechanical and dielectric properties, attenuated total reflection–Fourier transform infrared investigation, thermogravimetric analysis, and surface morphology characterization. A stronger ionic interaction and solvation capacity of the ions and a higher ionic conductivity were manifested in the case of poly(ethylene oxide)‐rich segments than for poly(propylene oxide)‐rich segments in these polyurethane ionomers. The molecular and ionic interactions of the bile‐salt moiety with different polyether cosoft segments influenced chain packing and conformation, supramolecular organization, and the resulting surface morphological microstructures of the polyurethane biomembranes. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42921.     

Effects of benzoyl peroxide on some properties of composites based on hemp and natural rubber

The obtaining and characterization of polymer composites based on natural rubber and hemp, in which the elastomer crosslinking has been achieved with benzoyl peroxide, are presented. The mechanical characteristics, gel fraction, crosslink density, water uptake swelling parameters and FTIR of the composites based on natural rubber and hemp fiber vulcanized by dibenzoyl peroxide have been investigated as a function of the hemp content. The hardness, modulus at 100 % elongation, tearing strength, tensile strength and elongation at break have been improving with the increasing of fiber content in composites materials due to the better interaction of fiber in natural rubber composites. These results indicate that hemp has a reinforcing effect on natural rubber. Gel fraction value is over 95 % for all blends and varies irregularly depending on the amount of hemp in the composites. The crosslinking density (ν) of samples increases as the amount of hemp in blends increases, because hemp act as a filler in natural rubber blends and leads to reinforcement of the blends. The water uptake and swelling parameters also increases with the increasing of the amount of fiber content, because of the hemp hydrophilic characteristics.     

Synthesis of ternary zinc spinel oxides and their application in the photodegradation of organic pollutant

Ternary zinc spinel oxides such as Zn₂SnO₄, ZnAl₂O₄ and ZnFe₂O₄ were synthesized and characterized, and their activities in the photodegradation of phenol molecules were investigated. Zn₂SnO₄, ZnAl₂O₄ and ZnFe₂O₄ powders were synthesized by hydrothermal, metal–chitosan complexation and solvothermal routes, respectively. The face-centered cubic spinel structure of each material was confirmed by powder X-ray diffractometry (XRD) and its porous structure by N₂ adsorption–desorption isotherms. The characterization of spinels was complemented with Fourier transform infrared spectroscopy (FTIR) and X-rays fluorescence (XRF), revealing the formation of spinel structures with high purity. The photocatalytic activity in the degradation of phenol was observed only with Zn₂SnO₄ oxide. Mineralization degree of phenol molecules by Zn₂SnO₄ photocatalyst determined by total organic carbon analysis (TOC) reached 80% at 360 min under sunlight.     

Physical and Functional Properties of Blackberry Freeze- and Spray-Dried Powders

The aim of the present work was to develop two products from blackberry juice by freeze and spray drying with potential use as food colorants or healthy ingredients. A characterization of the physical and functional properties of the powdered juices was done. Maltodextrin or a mixture of trehalose and maltodextrin were assessed as carrier matrices. Freeze-dried, maltodextrin-containing powders presented the best retention of bioactive compounds and antiradical activity; however, they showed a narrow relative humidity range for storage in the glassy state. Spray-dried powders showed better physical properties, bearing higher glass transition temperature and lower molecular mobility than freeze-dried formulations.