Analysis of Brazilian SHP policy and its regulation scenario

This article presents the main regulatory changes that occurred in the Brazilian power sector in 2009, along with the impacts these changes caused on the market, especially related to small hydropower (<30 MW). This study addresses regulatory issues based on inventory studies and records of basic projects, changes related to the compensation of the assured energy of SHPs in the Brazilian energy reallocation market, the socio-economic impact resulting from the construction of SHPs, SHPs in alternative resource auctions and finally the general outlook for the growth scenario for SHPs in Brazil according to the ten-year plan (2010–2019). The overall conclusions of this investigation were that the 2008/2009 biennium was a period of great changes in the regulation of small hydropower plants in Brazil, and the SHP market has shown maturity. Additionally, despite SHP being a type of technology that is completely dominated by domestic industry, in recent years, they have experienced policy disincentives caused by changes to rules that inhibit their growth.     

Analysis of phenolic compounds in cork from Quercus suber L. by HPLC–DAD/ESI–MS

The aim of the present work was to identify the extractable phenolic compounds present in cork from Quercus suber L. The structures of thirty three compounds were tentatively identified by liquid chromatography coupled to electrospray ionisation mass spectrometry (HPLC–DAD/ESI–MS). The majority of those compounds were gallic acid derivatives, in the form of either galloyl esters of glucose (gallotannins), combinations of galloyl and hexahydroxydiphenoyl esters of glucose (ellagitannins), dehydrated tergallic-C-glucosides or ellagic acid derivatives. Others were found to correspond to low molecular weight phenolic compounds, like acids and aldehydes. Mongolicain, a flavanoellagitannin in which hydrolysable tannin and flavan-3-ol moieties are connected through a carbon–carbon linkage, was also detected in cork from Q. suber L. The results illustrate the rich array of phenolic compounds present in cork.     

The rapid synthesis of nanostructured orthorhombic KNbO3 particles by a microwave-assisted hydrothermal method and their characterization

We studied the molar ratio effects of niobium and potassium precursors on the structure and morphology of potassium niobate powders prepared via microwave-assisted hydrothermal synthesis (MaHS). KNbO₃ nanostructures in the form of nanotowers and nanocubes were obtained at reduced synthesis times (30–240 min). The products were characterized via XRD, Raman spectroscopy, SEM, and TEM; band gap calculations used diffuse reflectance data. The results indicate that KNbO₃ nanostructures were obtained with crystallite sizes ranging from 33 to 52 nm. An orthorhombic crystalline structure was formed from the increase of KOH at a molar ratio Nb₂O₅:KOH (1:8 to 1:16 M). The band-gap of 3.1–3.3 eV has potential use in photodegradation applications.     

Experimental design of the kinetic resolution of a key precursor of high‐value bioactive myo‐inositols by an immobilized lipase

BACKGROUND: The response surface methodology was successfully applied to the optimization of the reaction variables for the kinetic resolution of a precursor of high‐value myo‐inositols, ( ± )‐1,2‐O‐isopropylidene‐3,6‐di‐O‐benzyl‐myo‐inositol (( ± )‐1), by Novozym 435. The resolutions were run separately, with two acylating agents, ethyl acetate and vinyl acetate, in a solvent‐free system. The variables analyzed were reaction temperature, substrate concentration, water concentration and enzyme activity. A statistical model was employed for the evaluation of the influence of the variables on conversion and enantiomeric excess (ee). RESULTS: The optimal conditions for this resolution using vinyl acetate as acylating agent were 45 °C, 5 mg mL^?1 of substrate, 71 U of enzyme activity and 0%w/w of water concentration. The high conversion (49.2 %) and ee (>99%) reached in the chemoenzymatic synthesis of acylated product, L‐(?)‐5‐O‐Acetyl‐3,6‐di‐O‐benzyl‐1,2‐O‐isopropylidene‐myo‐inositol, secure the efficient synthesis of the D enantiomorph present in the original racemic mixture (( ± )‐1) as well. CONCLUSIONS: The use of the experimental design strategy was productive, leading to a 14‐fold increase in the productivity of the reaction compared with the non‐optimized conditions. Both derivative L‐(?)‐2 and remaining substrate D‐(+)‐1 were obtained at high ee. © 2012 Society of Chemical Industry     

Failure analysis of a cylinder sleeve from a turbocharged diesel engine

This work presents the conclusions of a failure analysis performed on a V12 Turbo Charged diesel engine cylinder sleeve. The failure analysis carried out established the most relevant factors that caused damage to the cylinder sleeve. An examination of the internal surface of the cylinder sleeve revealed an elevated number of cavities close to the top center area, which acted as stress concentrators reducing the resistance of the component, creating crack nucleation spots. Additionally there were internal differences in the microstructure of the component, which indicate that different cooling conditions occurred during its manufacture, providing a secondary failure mechanism, due to material fragility.     

The roles of textural images in improving land-cover classification in the Brazilian Amazon

Texture has long been recognized as valuable in improving land-cover classification, but how data from different sensors with varying spatial resolutions affect the selection of textural images is poorly understood. This research examines textural images from the Landsat Thematic Mapper (TM), ALOS (Advanced Land Observing Satellite) PALSAR (Phased Array type L-band Synthetic Aperture Radar), the SPOT (Satellite Pour l’Observation de la Terre) high-resolution geometric (HRG) instrument, and the QuickBird satellite, which have pixel sizes of 30, 12.5, 10/5, and 0.6 m, respectively, for land-cover classification in the Brazilian Amazon. GLCM (grey-level co-occurrence matrix)-based texture measures with various sizes of moving windows are used to extract textural images from the aforementioned sensor data. An index based on standard deviations and correlation coefficients is used to identify the best texture combination following separability analysis of land-cover types based on training sample plots. A maximum likelihood classifier is used to conduct the land-cover classification, and the results are evaluated using field survey data. This research shows the importance of textural images in improving land-cover classification, and the importance becomes more significant as the pixel size improved. It is also shown that texture is especially important in the case of the ALOS PALSAR and QuickBird data. Overall, textural images have less capability in distinguishing land-cover types than spectral signatures, especially for Landsat TM imagery, but incorporation of textures into radiometric data is valuable for improving land-cover classification. The classification accuracy can be improved by 5.2–13.4% as the pixel size changes from 30 to 0.6 m.     

Adaptive Ray‐bundle Tracing with Memory Usage Prediction: Efficient Global Illumination in Large Scenes

This paper proposes an adaptive rendering technique for ray‐bundle tracing. Ray‐bundle tracing can be done by per‐pixel linked‐list construction on a GPU rasterization pipeline. This rasterization based approach offers significant benefits for the efficient generation of light maps (e.g., hardware acceleration, tessellation, and recycling of shaders used in real‐time graphics). However, it is inapplicable to large and complex scenes due to the limited capacity of the GPU memory because it requires a high‐resolution frame buffer and high‐capacity node buffer for the linked‐lists. In addition, memory overflow can potentially occur on the per‐pixel linked‐list since the memory usage of the lists is usually unknown before the rendering process. We introduce an adaptive tiling technique with memory usage prediction. Our method uses an appropriately tiled frame buffer, thus eliminating almost all of the overflow risks thanks to our adaptive tile subdivision scheme. Using this technique, we are able to render high‐quality light maps of large and complex scenes which cannot be computed using previous ray‐bundle based methods.     

Structural and chromatic characterization of a new Malvidin 3-glucoside–vanillyl–catechin pigment

A new pigment, resulting from the reaction between malvidin 3-glucoside and catechin in the presence of vanillin, was detected in a model solution. This newly formed anthocyanin-aryl-flavanol adduct was structurally characterized by 1D and 2D NMR and mass spectrometry, and its chromatic characteristics were studied by UV–Vis techniques. The new pigment was shown to have a wavelength of maximum absorption in the visible region (λ_max) of 549 nm, conferring on it a purple colour, and a molar extinction coefficient value (ε) of 12,247 l · mol⁻¹ · cm⁻¹.     

Influence of anthocyanins and derivative pigments from blueberry (Vaccinium myrtillus) extracts on MPP intestinal uptake: A structure–activity approach

The aim of the present study was to investigate the influence of an anthocyanin extract (extract I), and two other derivative extracts (extracts II and III), which are being developed aiming to be further applied in the food industry, on intestinal uptake of organic cations. For this purpose, the effect of these compounds on ³H-MPP⁺ uptake was evaluated in Caco-2 cells (an enterocyte-like cell line derived from a human colonic adenocarcinoma).