Agroclimatic zoning for winemaking grape production in the State of Paraná.

Paraná is the fourth largest grape producing state in Brazil and the cultivation of Vitis vinifera L. cultivars for winemaking is expanding is several regions of the state. The objective of this work was to characterize the potential of wine grape production based on the Géoviticulture Multicriteria Climatic Classification System for Paraná. A 30-year database constituted of 21 IAPAR (Agronomic Institute of Paraná) meteorological stations and 455 rainfall stations from Instituto das Águas do Paraná (Paraná State Water Institute) generated the following climatic indexes: dryness index (DI), heliothermal index (HI) and cool night index (CI) for the periods of October to March and April to September. According to the results, the viticultural climate of some regions in the state of Paraná belongs to the climatic groups where are found several traditional wine-producing regions in the world, showing potential for the expansion of winemaking in the state. Viticultural climate, associated with latitude in Paraná and with thermal conditions for vine growing cycle all over the year, make production displacement possible in the West, North and Northeastern regions and the production of the best quality grapes for winemaking in the fall and winter period, due to the most favorable cold night index and the lowest rainfall volume. In the coldest regions of the state (Center, South and East), it is only possible to have one production cycle, since the risk of frosts prevents the exploration of grapes in different periods

Distribution of Relaxation Times Based on Lasso Regression: A Tool for High-Resolution Analysis of IMPS Data in Photoelectrochemical Systems

Intensity-modulated photocurrent spectroscopy (IMPS) has been largely employed in semiconductor characterization for solar energy conversion devices to probe the operando behavior with widely available facilities. However, the implementation of IMPS data analysis to complex structures, whether based on the physical rate constant model (RCM) or the assumption-free distribution of relaxation times (DRT), is generally limited to a semi-quantitative description of the charge carrier kinetics of the system. In this study, a new algorithm for the analysis of IMPS data is developed, providing unprecedented time resolution to the investigation of μs to s charge carrier dynamics in semiconductor-based systems used in photoelectrochemistry and photovoltaics. The algorithm, based on the previously developed DRT analysis, is herein modified with a Lasso regression method and available to the reader free of charge. A validation of this new algorithm is performed on a α-Fe2O3 photoanode for photoelectrochemical water splitting, identified as a standard platform in the field, highlighting multiple potential-dependent charge transfer paths, otherwise hidden in the conventional IMPS data analysis

Indium-modified copper nanocubes for syngas production by aqueous CO2 electroreduction

Electroreduction of carbon dioxide represents an appealing strategy to rethink a waste product as a valuable feedstock for the formation of value-added compounds. Among the metal electrodes able to catalyze such processes, copper plays a central role due to its rich chemistry. Strategies aimed at tuning Cu selectivity comprise nanostructuring and alloying/post-functionalization with heterometals. In this contribution, we report on straightforward electrochemical methods for the formation of nanostructured Cu-In interfaces. The latter were fully characterized and then used as cathodes for CO2 electroreduction in aqueous environment, leading to the selective production of syngas, whose composition varies upon changing the applied bias and indium content. In particular, gaseous mixtures compatible with the synthesis of methanol or aldehydes (i.e. respectively with 1 : 2 and 1 : 1 CO/H2 ratios) are produced at low (i.e. −0.62 V vs. RHE) applied bias with >3.5 mA cm−2 current densities (in absolute value). Even if the proposed cathodes undergo structural modifications upon prolonged exposure to CO2 reduction conditions, their catalytic activity can be restored by introducing an additional In(iii) precursor to the electrolytic solution

Efficient Anodically Grown WO3 for Photoelectrochemical Water Splitting

Abstract The potentiostatic anodization of metallic tungsten has been investigated in different solvent/electrolyte compositions with the aim of improving the photoelectrochemical performances of the tungsten oxide layer. Among the explored electrolytes, the anodization in the NMF/H2O/NH4F solvent mixture was found to produce the most efficient WO3 photoanodes, which, combining spectral sensitivity, high electrochemically active surface and improved charge transfer kinetics, outperform, under simulated solar illumination, most of the reported nanocrystalline substrates produced by anodization in aqueous electrolytes and by sol gel methods. While the preparation of the photoelectrodes is a slow process at room temperature (20 °C), it could be greatly accelerated (x 10) by carrying out the anodization at 40-50 °C, thus proving to be a fast and convenient approach to the production of high performing WO3 photoactive substrates directly connected to a metal electron collector

Agroclimatic zoning for eucalyptus in the state of Paraná and the new scenarios defined by global climate change.

Brazil is a country with one the largest areas of forest plantations in the world. The state of Paraná (PR) has the largest area of designated plantations in the country. The main cultivated species belong to the genus Eucalyptus. In this work, the areas of better favorability for planting the main species of commercial value eucalyptus were defined. Additionally, changes may also occur in these zones in the coming decades, due to global climate change. For this purpose, future scenarios were elaborated using a stochastic time series simulation software, to assess the possible changes of the climate and indicate potential consequences regarding the changes of eucalyptus plantation zones. The results show that there will be an increase in areas favorable to the commercial plantations of E. grandis and E. urograndis, species cultivated in the Cfa climate zone (subtropical zones). For E. benthamii, a species cultivated mostly in the Cfb climate zone (temperate zones), there will be a reduction of suitable areas for commercial plantations in Paraná, with displacement to areas located to the south and at higher altitudes, where edaphic limitations may occur

Monitoramento e distribuição de ocorrência de Thaumastocoris peregrinus no Estado do Paraná.

bitstream/item/123257/1/CT-337-Leonardo.pd

Photoelectrochemical Valorization of Biomass Derivatives with Hematite Photoanodes Modified by Cocatalysts

The solar-driven oxidation of biomass to valuable chemicals is rising as a promising anodic reaction in photoelectrochemical cells, replacing the sluggish oxygen evolution reaction and improving the added value of the energy conversion process. Herein, the photooxidation of 5-hydroxymethylfurfural into furan dicarboxylic acid (FDCA) is performed in basic aqueous environment (borate buffer, pH 9.2), with the addition of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) as redox mediator. Because of its good stability, cost-effectiveness, and nontoxicity, titanium-modified hematite (Ti:Fe2O3) photoanodes are investigated to this aim, and their performance is tuned by engineering the semiconductor surface with a thin layer of Co-based cocatalysts, i.e., cobalt iron oxide (CoFeO x ) and cobalt phosphate (CoPi). Interestingly, the electrode modified with CoPi shows improved efficiency and selectivity toward the final product FDCA The source of this enhancement is correlated to the effect of the cocatalyst on the charge carrier dynamics, which is investigated by electrochemical impedance spectroscopy and intensity-modulated photocurrent spectroscopy analysis. In addition, the results of the latter are interpreted through a novel approach called Lasso distribution of relaxation time, revealing that CoPi cocatalyst is effective in the suppression of the recombination processes and in the enhancement of direct hole transfer to TEMPO

Análise da ocorrência de geadas no Estado do Paraná com base na temperatura de superfície obtida dos dados AVHRR/NOAA.

A ocorrência de geadas no Paraná tem sido um dos principais fatores causadores de perdas de safras de culturas anuais e perenes. Uma das culturas mais atingidas por esse fenômeno é a do café, localizado na região Norte do estado, em região de transição sujeita à ocorrência periódica de geadas (Caramori et al., 2001). O trigo também é suscetível às geadas nas fases de espigamento e enchimento dos grãos, quando mesmo geadas moderadas podem causar prejuízos severos. Neste caso a estratégia adotada é fugir das épocas de maior risco através do planejamento da época de semeadura (Gonçalves et al., 1998), mas a ocorrência de geadas precoces ou tardias ocasionalmente afeta a cultura, causando grandes prejuízos. Os estudos de risco de ocorrência de geadas, baseados em séries históricas de temperaturas mínimas do ar obtidas em estações meteorológicas, representam dados pontuais que necessitam serem interpolados para se obter a representação espacial da região de interesse. Por meio de imagens de satélite, pode-se obter o valor de pixel e desta forma contar com maior nível de detalhe, possibilitando identificar variações regionais que não são identificadas com dados das estações. Neste trabalho são apresentados resultados que fazem parte de um projeto que visa determinar as variações regionais dos riscos de geada, com base na temperatura de superfície obtida do sensor AVHRR a bordo dos satélites NOAA

Solvation Enhances the Distinction Between Carboxylated Armchair and Zigzag Single-Wall Carbon Nanotubes (SWNT-COOH)

The effect of various solvents on the structures and properties of carboxylated SWNTs has been explored using the Same Level Different Basis Set approach (SLDB), where B3LYP functional of density functional theory (DFT) was applied. Armchair (4,4) and zigzag (8,0) and (9,0) tubes were considered as the test bed. In order to simulate varying concentration of –COOH groups, one to five acids groups were placed at one end of these tubes. These samples were placed in different solvents (namely, CS2, THF and water) with varying polarity and results were compared with gas-phase properties. Similar to the gas-phase, zigzag tubes also exhibit both regular (r-COOH, v(C=O) above 1700 cm-1) and low-frequency (lf-COOH, v(C=O) below 1700 cm-1) acid groups. Characteristics of r-COOH group are not affected much in solvents, but lf-COOH of the zigzag tube is the one that makes these tubes distinguishable from its armchair cousin. Stability and charge distribution of SWNT-COOH strongly depend on the number of acid groups in different solvents which may help controlling further functionalization. Vibrational analyses reveal certain features in the 1400-1600 cm-1 range that are characteristic of lf-COOH in different solvents, which may help in the assignment of experimental spectra of oxidized SWNT in solvents