Search

The Klason method is adequate for quantifying lignin in softwood (SWD) but is less so for hardwood (HWD). The latter contains a fraction of acid-soluble lignin (ASL) that is not measurable under the conditions prevailing in the Klason method and that must be quantified by other means. This study aimed at investigating the composition of ASL obtained from eucalypt and pine woods by using pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). About 2.7% and 0.9% ASL by dry wood weight were measured in the acid filtrate of eucalypt and pine, respectively, by the Technical Association of the Pulp and Paper Industry (TAPPI) UM 250 method. The acid filtrate was lyophilized and processed by Py-GC-MS, allowing identification of 26 primary pyrolysis products, with 2% and 52% relative molar abundance coming from lignin and carbohydrates, respectively, for eucalypt and 24 primary pyrolysis products, with 1% and 54% relative molar abundance from lignin and carbohydrates, respectively, for pine. The main products derived from lignin were phenol, 4-methylphenol, guaiacol, 4-methylcatechol, syringol, acetosyringone and vanillin. It was concluded that measurements of ASL remain a requirement for accurate eucalypt and pine wood lignin quantification because lignin derivatives remain in the acid filtrate from the Klason lignin quantification method. Corrections for carbohydrate-derived compounds are not necessary, despite their predominance in the filtrate, because these derivatives do not interfere with ultraviolet (UV) absorption. [ABSTRACT FROM AUTHOR]

The sunflower is presented as a promising crop for biodiesel production, in addition, to provide improved soil fertility by having a high capacity for nutrient cycling absorbed in depth and a reduced rate of nutrient export, but it is very demanding on nutrients as boron and potassium. Therefore, we evaluated the effect of fertilization borácica and potassium in sunflower farming Catissol. The experimental design was a randomized complete block in a split-plot, 5 x 4 with five repetitions. The treatments consisted of a combination of five doses of boron (0, 2, 4, 6 and 8 kg ha-1), with four levels of potassium (0, 30, 60 and 90 kg ha-1). Plants were harvested at 72 days after sowing and were evaluated for height, leaf area, dry biomass and productivity. Doses of 6 and 90 kg ha-1 of boron and potassium, respectively, provided better responses in height (190 cm), leaf area (4374 cm2), shoot dry biomass (175 g) and productivity of 4170 kg ha-1. [ABSTRACT FROM AUTHOR]

As regards the question of originality, this article examines the material and formal elements that are new with respect to some previous works of St John of the Cross. Three aspects are discussed: originality in form, in the use of new vocabulary and in the use of sources already employed in other works; originality in the symbolism of the book Living Flame of Love; and originality of some themes or topics developed in that work. This requires comparison with the saint's earlier writings, as well as with those of other authors in his milieu. [ABSTRACT FROM AUTHOR]