Educação matemática pela arte
Gusmão, Lucimar Donizete
2013-08-28
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excerpt:...In order to be able to discuss how the space in the exhibitionary complex is
governed by the multiple users of it, I will reason towards a better outline of the term
space in this respect using Christian Norberg-Schulz’s theories on space. This will lead
me to the culmination of a spatial territory in the exhibitionary complex over which three
groups that are active in this complex – architect, curator and artist – seek to have
control. The subject in this endeavour is the viewer which every group will try to
activate in its own way. After contemplating on the theoretical side of the matters
discussed in this thesis, I find it of importance to elaborate on the practical
consequences of the spatial development. Therefore, as a tool to combine the ideas
uttered in the theoretical part, I will finish this thesis with a case-stu...
Distinct spectral features at the Fe L-edge of the two compounds K3[Fe(CN)6] and K4[Fe(CN)6]
have been identified and characterized as arising from contributions of the ligand ð* orbitals due to metalto-
ligand back-bonding. In addition, the L-edge energy shifts and total intensities allow changes in the
ligand field and effective nuclear charge to be determined. It is found that the ligand field term dominates
the edge energy shift. The results of the experimental analysis were compared to BP86 DFT calculations.
The overall agreement between the calculations and experiment is good; however, a larger difference in
the amount of ð back-donation between Fe(II) and Fe(III) is found experimentally. The analysis of L-edge
spectral shape, energy shift, and total intensity demonstrates that Fe L-edge X-ray absorption spectroscopy
provides a d...
New highly mixed phases have been identified in Cu/ZnO systems by EXAFS and XANES at both the Cu
and Zn K-edge. The phases were generated by ball-milling Cu2O/ZnO mixtures under three different
atmospheres of synthetic air (SA), SA + CO2 and CO2. The system milled in CO2 shows disproportionation
of Cu2O into Cu0, Cu1+ (cuprite Cu2O-type phase) and Cu2+ (tenorite CuO-type phase), while most of the
Zn2+ is transformed into a nanocrystalline/amorphous ZnO-type zincite that forms a superficial mixture of
oxide and carbonate phases. When synthetic air is added to the CO2 atmosphere, ball milling results in the
oxidation of nearly half the Cu1+ into Cu2+ with no Cu metal formed. The copper phase in this material is
almost entirely amorphous. In SA, a significant amount of Cu2+- and Zn2+-based phases appears to react to
form a nanocrystalline...
The long-term heat stabilisation efficiency of (natural) polyol additives in heavy metal- and zinc-free poly(vinyl chloride) (PVC)
has been investigated. It is shown that polyols, such as sorbitol and xylitol, markedly reduce the dehydrochlorination rate and
improve Congo Red values. Extraction experiments on unprocessed and ground-processed PVC-sorbitol (1.0 phr) mixtures after
thermal degradation at 200 C revealed that especially in the ground-processed PVC-sorbitol system, sorbitol is partly converted
into its mono- and dianhydro-derivatives 1,4-sorbitan and isosorbide, respectively. Apparently, the HCl released during thermal
degradation acts as the catalyst. Similar intramolecular cyclodehydration reactions also occur with the natural polyols, erythritol
and xylitol, under these conditions. Scrutiny of the measured dehydrochlorin...
Cooperative vibronic emission transitions are reported for Gd3+ in NaLa(SO4)2H2O. They involve the electronic 6P → 8S transition on the Gd3+ ion and the asymmetric-valence-vibrational transition on the SO42− anion and the H2O molecule which are both coordinated to the Gd3+ ion.
