5 documents found, page 1 of 1
Physicochemical Properties of Fe-Bearing Phases from Commercial Colombian Coal Ash
Santos, Ana Cláudia; Cruz, Cláudia; Font, Eric; French, David; Guedes, Alexandra; Moreira, Karen; Sant'Ovaia, Helena; Vieira, Bruno J. C.High amounts of coal combustion products, such as fly ash and bottom ash, are generated every year; however, only 64% are used, which means that a significant part is landfilled despite containing valuable materials such as ferrospheres, which may be used as catalysts, substituting critical raw materials (e.g., platinoids). In commercial coals, pyrite contents are reduced as a pre-combustion S-emissions control...
The Mössbauer effect using 57Fe-ferrabisdicarbollide ([o-57FESAN]−) : a glance ...
Buades, Ana B.; Pereira, Laura C. J.; Vieira, Bruno J. C.; Cerdeira, Ana C.; Waerenborgh, João C.; Pinheiro, Teresa; Matos, António P. A.Although a variety of cancers are initially susceptible to chemotherapy, they eventually develop multi-drug resistance. To overcome this situation, more effective and selective treatments are necessary using anti-tumour agents that act in two or more ways and offer greater therapeutic benefits over single-mechanism entities. In this study, we report on treating cancer with Na[3,3′-57Fe(1,2-C2B9H11)2], which off...
Chemistry of volcanic soils used for agriculture in Brava Island (Cape Verde) e...
Marques, Rosa; Vieira, Bruno J.; Prudêncio, M. Isabel; Waerenborgh, João C.; Dias, M. Isabel; Rocha, FernandoIn order to acquire a better knowledge of iron forms, clay minerals and the content and distribution of trace elements in soils mostly used for agriculture in the semi-arid Brava Island (Cape Verde), iron speciation, mineralogy and chemical contents in the clay-size fraction (<2 μm) of incipient soils developed on sediments and phonolitic pyroclasts was performed by Mössbauer spectroscopy, X-ray diffraction and...
Oxygen Nonstoichiometry, Mixed Conductivity, and Mössbauer Spectra of Ln0.5A0.5...
Kharton, Vladislav V.; Kovalevsky, Andrei V.; Patrakeev, Mikhail V.; Tsipis, Ekaterina V.; Viskup, Alexandre P.; Kolotygin, Vladislav A.Increasing the difference of the Ln3+ and A2+ cation radii in perovskite-type Ln0.5A0.5FeO3−δ (Ln = La, Pr, Nd, Sm; A = Sr, Ba) results in higher oxygen deficiency and lower oxygen-ionic and p-type electronic conductivities, determined using the oxygen permeation and total conductivity measurements at 973−1223 K. The relationships between the anion transport and A-site cation size mismatch remain essentially si...
57Fe Mossbauer spectroscopy study of the correlation between the Fe3+ content a...
Waerenborgh, João C.; Figueiras, Jorge; A., Mateus; A. Gonçalves, MárioBoth the Fe oxidation degree and the magnetic properties determined by 57Fe Mössbauer spectroscopy were used to characterize the Cr-spinels from the Beja-Acebuches Ophiolite Complex (SE Portugal). Two different types of Cr-spinel were observed. The first one has an average Fe3+/(Fe total) ≈ 25%, and corresponds to unaltered Cr-spinel grains which remain paramagnetic down to 6K. The second one results from the ...