Condicionamento geologico da agua subterranea em Sao Jose,do Rio Preto, SP.

A study of the geological characteristics of the Buaru Group basaltic substratum and stratigraphical unities was carried out, taking into account the groundwater exploration in S.Jose do Rio Preto area. The presence of the tectonic structures in this substratum exercised a profound influence on the sedimentation of the Bauru Group and on the variations in the hydrological properties of the sediments of the area.-English summar

KRAFT PULPING CHARACTERISTICS OF THREE MOROCCAN EUCALYPTI. PART 1. PHYSICAL AND CHEMICAL PROPERTIES OF WOODS AND PULPS

Two eucalyptus hybrids (EGC 39, EGC 241), resulting from crosses between Eucalyptus grandis and Eucalyptus camaldulensis, were investigated to see if they could produce kraft papermaking fibers with low lignin and adequate physical properties. The two hybrids were harvested at an age of 8 years along with 6-8 year old Eucalyptus camaldulensis (Rostrata). All three eucalypti were grown in the area of Gharb in the North-West of Morocco. The tracheids in the two hybrids had a very high Runkel ratio (2 x cell wall thickness/lumen diameter) and produced kraft paper sheets with low tensile strength due to a low degree of fiber collapse thus a low relative bonded area. These fibers could be used to increase the stiffness of a papermaking furnish. The lignin in the EGC 39 chips was more reactive in kraft pulping as compared to the other two eucalypti. Methoxyl analyses and nitrobenzene oxidation (NBO) of the in-situ lignin (wood meals) were performed, and it was concluded that the syringyl content of the EGC 39 lignin was less than or equal to those in the other two eucalypti. Differences in the guaiacyl fraction of the three samples will be discussed in Part 2 of this series

KRAFT PULPING CHARACTERISTICS OF THREE MOROCCAN EUCALYPTI. PART 2. COMPARISON OF THE GUAIACYL FRACTION OF THE NATIVE LIGNINS BY A NOVEL METHOD

In Part 1 of this series it was observed that one of the eucalypti (EGC 39) was more reactive than the other two in kraft and soda-AQ (SAQ) cooking. However, the lignin in EGC 39 contained equal or less syringyl (S) units than the other two eucalypti. In the present research an attempt was made to compare the guaiacyl (G) fraction of the three lignins. The approach was to use SAQ treatment to cleave β-O-4 bonds in dimeric units containing uncondensed guaiacyl A-rings (those rearranging to quinone methides). The coniferyl alcohol, vinylguaiacol and isoeugenol generated from β-O-4 cleavage are then trapped as dimers by ethylguaiacol that is included in the SAQ liquor. Research with sugar maple (Acer saccharum) showed that the estimate of these structures (uncondensed G-β-O-4) by this approach was in close agreement with traditional but more tedious methods such as permanganate oxidation and 31P NMR. It was also shown that the lignin in the EGC 39 hybrid contained a higher concentration of uncondensed G-β-O-4 structures than the other two eucalypti lignins