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Core-mantle differentiation is the largest event experienced by a growing planet during its early history. Terrestrial core segregation imprinted the residual mantle composition by scavenging siderophile (iron-loving) elements such as tungsten, cobalt and sulphur. Cosmochemical constraints suggest that about 97% of Earth's sulphur should at present reside(More)
Lignins were extracted from different species using organosolv process (ethanol/water). Obtained organosolv lignins were characterised by various methods to determine their composition, structure and functional groups with the purpose of evaluating their potential use for obtaining value-added compounds. The purity of organosolv lignins was determined. The(More)
In this study microcrystalline cellulose (MCC) was oxidized by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation. The treated cellulose slurry was mechanically homogenized to form a transparent dispersion which consisted of individual cellulose nanofibers with uniform widths of 3–4 nm. Bio-nanocomposite films were then prepared from a(More)
In this study a largely available lignocellulose feedstock hemp (Cannabis sativa), obtained as an industrial waste, was used for cellulose extraction. The extraction of cellulose microfibres from hemp biomass was conducted by alkaline treatment and an acidification process. The extracted cellulose microfibres were characterised using Fourier-transformed(More)
The development of value-added lignin products from industrial residues of pulping is still a challenge. The present study was aimed to use oil obtained from organosolv lignin by base-catalyzed depolymerization at 300 °C for 40 min as a wood-protecting agent. First, the bio-oil was diluted to 1 wt% into an acetone and water solution, and physicochemical(More)
Organosolv lignin, obtained from olive tree pruning under optimized conditions, was subjected to a hydrothermal depolymerization process catalyzed by sodium hydroxide. The depolymerization of lignin was carried out at 300°C using different reaction times (20, 40, 60, 70, 80, 90, and 100 min) in order to study the influence of this parameter on lignin(More)
INTRODUCTION Despite the resurgence of tuberculosis, partly due to HIV infection, central nervous system involvement remains rare, accounting for only 2 to 5% of all tuberculosis forms. PATIENTS ET METHOD: We report six cases of brain tuberculomas occurring in patients free of HIV infection and hospitalized between 2001 and 2006 in the internal medicine(More)
In this study, a new simple method for chemical modification of wood from fast-growing Eucalyptus saligna (blue gum) was tested by a two-step treatment with methacryloyl chloride. The wood samples were submerged in a solution of 10 % methacryloyl chloride in dichloromethane for 15 h and then exposed to three temperatures: air dried, 50 and 100 °C for 2 h.(More)