162,323 research outputs found
[Report to Chief J. E. Curry, by an unknown author #1]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
[Report to Chief J. E. Curry, by an unknown author #2]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
Magnetic wood-based biomorphic Sr3Co2Fe24O41 Z-type hexaferrite ecoceramics made from cork templates
No full textEcoceramics (environmentally conscious ceramics) are biomimetic/biomorphic ceramics, which use a naturally occurring and sustainable material as a template for their unique morphology and structure. Usually woods (or lignocellulosics) are used, due to the inherent cellular nature of their microstructures. The wood is pyrolised and the resulting carbon skeleton impregnated with a fluid, and this is then heated to combust the carbon template and convert the fluid precursor into a ceramic, while maintaining the structure of the original natural template. For the first time, ecoceramics have been made from cork, a totally sustainable wood that is harvested without harming the tree. Also for the first time, ecoceramics have been made of soft magnetic Z-type hexaferrites, in this case the room temperature multiferroic strontium Z ferrite Sr3Co2Fe24O41 (SrZ). Cork powder was pyrolised at 1000 degrees C, infiltrated with an aqueous sol-gel SrZ precursor, and then heated at 1200 degrees C/2 h to produce the ecoceramic. The cellular structure of the cork was maintained, with a small reduction in the hexagonal cell dimension to 10 mu m diameter, but the cell walls remained 1-2 mu m thick, of a similar magnitude to the hexaferrite grain size. Both magnetic and XRD data agreed that there was a small portion of the SrW phase present in these ecoceramics as well, and the magnetic loop showed a magnetically soft ecoceramic with M-s = 59.5 A m(2) kg(-1) (at 3 T), and a low H-c of 16 kA m(-1). (C) 2015 Elsevier Ltd. All rights reserved
Aqueous Acid Orange 7 dye removal by clay and red mud mixes
No full textIn this study, Portuguese clay, Fe-impregnated clay, red mud and clay/red mud mixtures were used in the removal of Acid Orange 7 by Fenton and photo-Fenton (under UV light) oxidation processes. In comparison with pure adsorption, the catalytic activity of Fe-loaded clay showed an optimum removal rate (98%). This photo-assisted Fenton degradation of Acid Orange 7 azo-dye molecules was exploiting HO radicals from generated H2O2 and clay supported iron species, following the pseudo-first order kinetic mechanism.By using red mud pre-calcined at 400 °C, 10% improvement in overall discolouration was observed in comparison to the untreated clay. This improvement is attributed to the partial reduction of Fe3+ to Fe2+ species on the surface of the catalyst, and to the reaction with H2O2 to generate highly oxidative hydroxyl radicals. It was seen that the synergistic effect of photocatalysis due to the presence of TiO2 in the red mud also contributed in this photo-Fenton process. Furthermore, the use of red mud/clay catalyst mixes assured 38% dye discolouration at pH 7, but a lowering of solution pH to 3 resulted in a much higher discolouration rate (over 80% after 1 h). The good fitting with a pseudo-second-order kinetic model (R2 equals to 0.99) shows that adsorption processes could strongly contribute in the dye removal efficiency
Life cycle Assessment (LCA) of Sustainable Building Materials: An Overview
No full textEco-efficient Construction and Building Materials reviews ways of assessing the environmental impact of construction and building materials
Geopolymer foams: An overview of recent advancements
No full textGeopolymer foams (highly porous materials) have emerged as one of the most exciting materials over the past few years due to their remarkable properties, low cost and green synthesis protocol, enabling their use in various high added-value applications. Review papers on porous geopolymers are uncommon, and the emphasis has been given to materials processing and properties, while the applications were only briefly addressed. This review aims to fill this gap by presenting a comprehensive literature survey and critical analysis of the most recent and exciting research carried out on geopolymer foams. Up to now, these bulk-type (not powders) materials have been mainly considered as thermal and acoustic insulators. However, besides addressing their use as building material, this review also shows that their use in less investigated, but environmentally and economically relevant applications (e.g. bulk-type adsorbents, pH buffering agents and catalysts), is feasible and might ensure performance and technical advantages over their powdered counterparts. The limitations, challenges and future prospects associated with the different applications are presented. This review shows the remarkable potential of geopolymer foams in high added-value applications, far beyond their historical use as Portland cement replacement, which may encourage the widespread technological use of these materials
Chromatic properties of industrial solid waste based ferrites
No full textThe hexaferrite and monoferrite powders were prepared by the common solid state reaction method. Similar formulations have been prepared but using chemically- pure commercial reagents or by using a sludge generated by steel wiredraw process as source of iron oxide. This iron-rich industrial waste is mainly composed of Fe2O3 (62 wt%). Zinc and calcium are present in minor quantities and can form complexes such as franklinite (ZnFe2O4) and apatite (Ca5(PO4) 3(OH,F,Cl)). Ni/Cr galvanising sludge was also used to enhance the black coloration of monoferrite. After calcination of the mixtures at 1,000 °C and 1,050 °C, typical X-ray diffraction patterns of the expected SrFe12O19 and NiFe2O4 phases were obtained, together with minor peaks of spinel-type (SrFe2O 4 and ZnFe2O4) and Fe2O3 phases. Anyway, this resulted in a black pigment with chromatic properties comparable to those of commercial formulations, such as iron cobalt chromite (Fe,Co)(Fe,Cr)2O4 (DCMA 13-40-9), chrome iron nickel (Ni,Fe)(Fe,Cr)2O2 (DCMA 13-50-9), and manganese ferrite (Fe,Mn)(Fe,Mn)2O4 (DCMA 13-41-9). © Springer Science+Business Media B.V. 2012
Murder on the mountain: author talk with Peter J. Wosh
No full textAuthor talk by Peter J. Wosh on May 5th, 2022, on his book, "Murder on the Mountain: crime, passion, and punishment in gilded age New Jersey.
Valorisation of industrial iron oxide waste to produce magnetic barium hexaferrite
No full textBarium M-type hexagonal ferrite (BaM, BaFe12O19) is an immensely important magnetic material, which we have successfully made from the simple valorisation of Fe-rich industrial waste from steel wire drawing, with addition of BaCO3 and heating in air to 1000 oC. The optimum ratio of Fe.Ba (producing 86 wt% BaM) was found to be 11:1 (non-stoichiometric), and secondary phases of α-Fe2O3 (non-magnetic) and ZnFe2O4 (poorly antiferromagnetic) were always present. This material consisted of small submicron platelets. A hard magnetic ferrite was produced with Ms=48.6 A m2 kg–1 and Hc=211.5 kA m–1. The highest density was achieved by sintering samples with Fe:Ba ratios of 11:1 and 12:1 at 1200 °C / 2 hr, with an increase in grain size up to 2 μm. The sintered 11:1 had electrical conductivity comparable to that of commercial sintered BaM. Such materials are suitable for industrial applications as hard magnets, and EM shielding in architectural and construction materials
Mr. Melvin J. Collier, RWWL AUC, June 2011
No full textThis video is a conversation with Mr. Melvin J. Collier. Mr. Collier talks about his book, "From Mississippi to Africa: A Journey of Discovery". Daniel Le, AUC Woodruff Library, is the interviewer
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