Advances in chemometric control of commercial diesel adulteration by kerosene using IR spectroscopy

Adulteration is a recurrent issue found in fuel screening. Commercial diesel contamination by kerosene is highly difficult to be detected via physicochemical methods applied in market. Although the contamination may affect diesel quality and storage stability, there is a lack of efficient methodologies for this evaluation. This paper assessed the use of IR spectroscopies (MIR and NIR) coupled with partial least squares (PLS) regression, support vector machine regression (SVR), and multivariate curve resolution with alternating least squares (MCR-ALS) calibration models for quantifying and identifying the presence of kerosene adulterant in commercial diesel. Moreover, principal component analysis (PCA), successive projections algorithm (SPA), and genetic algorithm (GA) tools coupled to linear discriminant analysis were used to observe the degradation behavior of 60 samples of pure and kerosene-added diesel fuel in different concentrations over 60 days of storage. Physicochemical properties of commercial diesel with 15% kerosene remained within conformity with Brazilian screening specifications; in addition, specified tests were not able to identify changes in the blends’ performance over time. By using multivariate classification, the samples of pure and contaminated fuel were accurately classified by aging level into two well-defined groups, and some spectral features related to fuel degradation products were detected. PLS and SVR were accurate to quantify kerosene in the 2.5–40% (v/v) range, reaching RMSEC < 2.59% and RMSEP < 5.56%, with high correlation between real and predicted concentrations. MCR-ALS with correlation constraint was able to identify and recover the spectral profile of commercial diesel and kerosene adulterant from the IR spectra of contaminated blends

Proportion of phosphate fertilizer in tropical forage grass in Oxisol

Objetivou-se identificar a proporção de fosfato natural reativo e superfosfato simples em que há maior produção e valor SPAD do capim-marandu cultivado em Latossolo Vermelho argilo arenoso com baixo teor de fósforo. O experimento foi realizado em casa de vegetação, em delineamento inteiramente casualizado, com oito repetições e em esquema de parcelas subdivididas no tempo. Para massa seca de raízes e custo da adubação fosfatada não se adotou esquema de parcelas subdivididas no tempo. As parcelas consistiram em seis níveis de substituição de superfosfato simples por fosfato natural reativo: 0, 20, 40, 60, 80 e 100%. As subparcelas consistiram em três períodos de crescimento: 30, 50 e 70 dias após a emergência das plântulas. As variáveis avaliadas foram: massa seca da parte aérea, lâminas foliares, colmo+bainha, resíduo e raízes, número de folhas, perfilhos, valor SPAD e custo da adubação fosfatada. A máxima produção de massa seca da parte aérea e o menor custo da adubação fosfatada do capim-marandu ocorrem quando se aplica, após a calagem, 35% do fósforo na forma de fosfato natural reativo e 65% na forma de superfosfato simples.This study aimed to identify the optimal proportion of rock phosphate and superphosphate in which there is increased production and SPAD value of palisadegrass grown in sandy clayey Oxisol with low phosphorus. A greenhouse experiment was conducted as split plot (time) design, with eight replications. Main plots consisted of six levels of substitution of superphosphate by rock phosphate: 0, 20, 40, 60, 80 and 100%. Split-plot consisted of three growth periods: 30, 50 e 70 days after seedlings emergence. The evaluated variables were: shoot, leaf blade, stem, root and litter dry mass; number of leaves and tillers; SPAD value, and cost of phosphate fertilization. The larger shoot dry mass production and lower cost of the phosphate fertilizer corresponded to applying phosphorous fertilizer, after liming, in the proportion 35% rock phosphate and 65% superphosphate.Facultad de Ciencias Agrarias y Forestale

Proportion of phosphate fertilizer in tropical forage grass in Oxisol

Objetivou-se identificar a proporção de fosfato natural reativo e superfosfato simples em que há maior produção e valor SPAD do capim-marandu cultivado em Latossolo Vermelho argilo arenoso com baixo teor de fósforo. O experimento foi realizado em casa de vegetação, em delineamento inteiramente casualizado, com oito repetições e em esquema de parcelas subdivididas no tempo. Para massa seca de raízes e custo da adubação fosfatada não se adotou esquema de parcelas subdivididas no tempo. As parcelas consistiram em seis níveis de substituição de superfosfato simples por fosfato natural reativo: 0, 20, 40, 60, 80 e 100%. As subparcelas consistiram em três períodos de crescimento: 30, 50 e 70 dias após a emergência das plântulas. As variáveis avaliadas foram: massa seca da parte aérea, lâminas foliares, colmo+bainha, resíduo e raízes, número de folhas, perfilhos, valor SPAD e custo da adubação fosfatada. A máxima produção de massa seca da parte aérea e o menor custo da adubação fosfatada do capim-marandu ocorrem quando se aplica, após a calagem, 35% do fósforo na forma de fosfato natural reativo e 65% na forma de superfosfato simples.This study aimed to identify the optimal proportion of rock phosphate and superphosphate in which there is increased production and SPAD value of palisadegrass grown in sandy clayey Oxisol with low phosphorus. A greenhouse experiment was conducted as split plot (time) design, with eight replications. Main plots consisted of six levels of substitution of superphosphate by rock phosphate: 0, 20, 40, 60, 80 and 100%. Split-plot consisted of three growth periods: 30, 50 e 70 days after seedlings emergence. The evaluated variables were: shoot, leaf blade, stem, root and litter dry mass; number of leaves and tillers; SPAD value, and cost of phosphate fertilization. The larger shoot dry mass production and lower cost of the phosphate fertilizer corresponded to applying phosphorous fertilizer, after liming, in the proportion 35% rock phosphate and 65% superphosphate.Facultad de Ciencias Agrarias y Forestale

Proportion of phosphate fertilizer in tropical forage grass in Oxisol

Objetivou-se identificar a proporção de fosfato natural reativo e superfosfato simples em que há maior produção e valor SPAD do capim-marandu cultivado em Latossolo Vermelho argilo arenoso com baixo teor de fósforo. O experimento foi realizado em casa de vegetação, em delineamento inteiramente casualizado, com oito repetições e em esquema de parcelas subdivididas no tempo. Para massa seca de raízes e custo da adubação fosfatada não se adotou esquema de parcelas subdivididas no tempo. As parcelas consistiram em seis níveis de substituição de superfosfato simples por fosfato natural reativo: 0, 20, 40, 60, 80 e 100%. As subparcelas consistiram em três períodos de crescimento: 30, 50 e 70 dias após a emergência das plântulas. As variáveis avaliadas foram: massa seca da parte aérea, lâminas foliares, colmo+bainha, resíduo e raízes, número de folhas, perfilhos, valor SPAD e custo da adubação fosfatada. A máxima produção de massa seca da parte aérea e o menor custo da adubação fosfatada do capim-marandu ocorrem quando se aplica, após a calagem, 35% do fósforo na forma de fosfato natural reativo e 65% na forma de superfosfato simples.This study aimed to identify the optimal proportion of rock phosphate and superphosphate in which there is increased production and SPAD value of palisadegrass grown in sandy clayey Oxisol with low phosphorus. A greenhouse experiment was conducted as split plot (time) design, with eight replications. Main plots consisted of six levels of substitution of superphosphate by rock phosphate: 0, 20, 40, 60, 80 and 100%. Split-plot consisted of three growth periods: 30, 50 e 70 days after seedlings emergence. The evaluated variables were: shoot, leaf blade, stem, root and litter dry mass; number of leaves and tillers; SPAD value, and cost of phosphate fertilization. The larger shoot dry mass production and lower cost of the phosphate fertilizer corresponded to applying phosphorous fertilizer, after liming, in the proportion 35% rock phosphate and 65% superphosphate.Facultad de Ciencias Agrarias y Forestale

Sugarcane evapotranspiration and irrigation requirements in tropical climates

Irrigation is necessary to help meet the high demand for water by sugarcane in several countries including Brazil and Australia. The crop irrigation requirements are typically estimated using the crop coefficient-reference evapotranspiration (Kc-ETo) procedure. Sugarcane evapotranspiration rates were measured in three different sugarcane-producing regions of the world, and crop coefficients (Kc) were derived for those diverse environments, irrigation methods, and farming systems, therefore representing a robust basis for irrigation management. We also verified the occurrence of the inverse relation between Kc and ETo found in previous studies. Two experiments in Brazil and one in Australia were used for the analysis. Our data showed that Kc for a full canopy cover was lower than 1.0 in the three experimental sites and that sugarcane evapotranspiration (ETc) seems to be limited and exceeds ETo only when this is below 4 mm day(-1). In one of the Brazilian experiments, Kc declined at higher rates than in the other two experiments, and for the three sites, average Kc was 0.77 and 0.87, respectively, for initial and full cover phase when ETo > 6 mm day(-1). The increase of aerodynamic and other upstream resistances to water transport of plants appears to be one of the reasons for Kc to decrease at high levels of ETo. Based on our data and the literature, the Kc values provided by Allen et al. (1998) could overestimate the irrigation needs of sugarcane under high evaporative demand conditions. Irrigation management based on Kc should use the average ETo from the preceding 3 days before irrigating to save water and energy while maintaining high yield levels

Sugarcane evapotranspiration and irrigation requirements in tropical climates

Irrigation is necessary to help meet the high demand for water by sugarcane in several countries including Brazil and Australia. The crop irrigation requirements are typically estimated using the crop coefficient-reference evapotranspiration (Kc-ETo) procedure. Sugarcane evapotranspiration rates were measured in three different sugarcane-producing regions of the world, and crop coefficients (Kc) were derived for those diverse environments, irrigation methods, and farming systems, therefore representing a robust basis for irrigation management. We also verified the occurrence of the inverse relation between Kc and ETo found in previous studies. Two experiments in Brazil and one in Australia were used for the analysis. Our data showed that Kc for a full canopy cover was lower than 1.0 in the three experimental sites and that sugarcane evapotranspiration (ETc) seems to be limited and exceeds ETo only when this is below 4 mm day(-1). In one of the Brazilian experiments, Kc declined at higher rates than in the other two experiments, and for the three sites, average Kc was 0.77 and 0.87, respectively, for initial and full cover phase when ETo > 6 mm day(-1). The increase of aerodynamic and other upstream resistances to water transport of plants appears to be one of the reasons for Kc to decrease at high levels of ETo. Based on our data and the literature, the Kc values provided by Allen et al. (1998) could overestimate the irrigation needs of sugarcane under high evaporative demand conditions. Irrigation management based on Kc should use the average ETo from the preceding 3 days before irrigating to save water and energy while maintaining high yield levels

Advances in chemometric control of commercial diesel adulteration by kerosene using IR spectroscopy

Adulteration is a recurrent issue found in fuel screening. Commercial diesel contamination by kerosene is highly difficult to be detected via physicochemical methods applied in market. Although the contamination may affect diesel quality and storage stability, there is a lack of efficient methodologies for this evaluation. This paper assessed the use of IR spectroscopies (MIR and NIR) coupled with partial least squares (PLS) regression, support vector machine regression (SVR), and multivariate curve resolution with alternating least squares (MCR-ALS) calibration models for quantifying and identifying the presence of kerosene adulterant in commercial diesel. Moreover, principal component analysis (PCA), successive projections algorithm (SPA), and genetic algorithm (GA) tools coupled to linear discriminant analysis were used to observe the degradation behavior of 60 samples of pure and kerosene-added diesel fuel in different concentrations over 60 days of storage. Physicochemical properties of commercial diesel with 15% kerosene remained within conformity with Brazilian screening specifications; in addition, specified tests were not able to identify changes in the blends’ performance over time. By using multivariate classification, the samples of pure and contaminated fuel were accurately classified by aging level into two well-defined groups, and some spectral features related to fuel degradation products were detected. PLS and SVR were accurate to quantify kerosene in the 2.5–40% (v/v) range, reaching RMSEC < 2.59% and RMSEP < 5.56%, with high correlation between real and predicted concentrations. MCR-ALS with correlation constraint was able to identify and recover the spectral profile of commercial diesel and kerosene adulterant from the IR spectra of contaminated blends