Prediction of service life of polymeric sealant compositions for fuel tanks in aerospace structures from measurements of viscoelastic properties Annual report

Prediction of service life of polymeric sealers for fuel tanks from viscoelastic measurement

Vanadium ore resources of the African continent: State of the Art

As part of the critical metals group, vanadium is an essential commodity for the low- and zero-CO2 energy generation, storage and transport. This contribution aims to carry out a review of the known vanadium ore sources and mineralizations located in Africa, which are highly diversified in their geological and mineralogical characteristics, and can be classified in: 1. Vanadiferous (titano)magnetite deposits; 2. Sandstone-hosted (U)-vanadium deposits; 3. Calcrete-hosted (U)-vanadium deposits; 4. Vanadate deposits; 5. Graphite-associated vanadium deposits; 6. Vanadium occurrences associated with laterite, bauxite, and phosphate ores. The economically most significant vanadium sources in Africa are associated with titanomagnetite layers in mafic–ultramafic layered magmatic intrusions (e.g., the Bushveld Complex in South Africa and the Great Dyke in Zimbabwe). Vanadium has been historically mined also in vanadate deposits deriving from the supergene alteration of Pb-Zn-Cu sulfide ores in Namibia and Zambia. Several areas in these countries, where potentially re-processable old tailings and slags have been accumulated, still have economic potential. Vanadium mineralizations are associated with graphite bodies in the Mozambique Metamorphic Belt. Vanadium is also enriched in uranium ores occurring in the Upper Paleozoic-Mesozoic Karoo continental sediments: typical examples are found in Botswana, South Africa, and Zimbabwe. Significant uranium-vanadium concentrations (where carnotite prevails) occur in relatively recent (Tertiary-Quaternary) calcrete duricrusts in paleo-fluviatile beds, which are widespread throughout the African continent. These derive from the weathering of U-(V)-fertile source rocks, which under favorable paleoclimatic conditions resulted in the vanadium precipitation in the critical zone. Variable vanadium amounts have been also recorded in iron ore deposits, phosphorites, and laterites, even though the phosphate deposits seem to have the most favorable characteristics for potentially economic vanadium concentrations. On the whole, South Africa holds the most significant vanadium ore resources globally. However, also many other African countries, where this metal could be profitably extracted as a by-product from other economic ores, will probably be at the forefront of vanadium production in the near future

The prevalences of Salmonella Genomic Island 1 variants in human and animal Salmonella Typhimurium DT104 are distinguishable using a Bayesian approach

Throughout the 1990s, there was an epidemic of multidrug resistant Salmonella Typhimurium DT104 in both animals and humans in Scotland. The use of antimicrobials in agriculture is often cited as a major source of antimicrobial resistance in pathogenic bacteria of humans, suggesting that DT104 in animals and humans should demonstrate similar prevalences of resistance determinants. Until very recently, only the application of molecular methods would allow such a comparison and our understanding has been hindered by the fact that surveillance data are primarily phenotypic in nature. Here, using large scale surveillance datasets and a novel Bayesian approach, we infer and compare the prevalence of Salmonella Genomic Island 1 (SGI1), SGI1 variants, and resistance determinants independent of SGI1 in animal and human DT104 isolates from such phenotypic data. We demonstrate differences in the prevalences of SGI1, SGI1-B, SGI1-C, absence of SGI1, and tetracycline resistance determinants independent of SGI1 between these human and animal populations, a finding that challenges established tenets that DT104 in domestic animals and humans are from the same well-mixed microbial population

The Business of Employing People with Disabilities: Four Case Studies

This exploratory study examines employer attitudes towards people with disabilities in the labor market. Through in-depth, semi-structured interviews with senior management, human resources staff, directors of diversity, and hiring managers at four corporations, it pinpoints reasons why businesses chose to hire people with disabilities, investigates the perceived benefits and barriers to hiring people with disabilities, and identifies strategies for successfully hiring and retaining workers with disabilities. It fills a gap in examining the attitudes and decision-making processes of U.S. companies that have been leaders in hiring people with disabilities, as well as delving into the special issues of small businesses that may lack exposure to disability employment. It closes with directions for future studies that could extend our understanding of employment of people with disabilities

ALCOHOL- AND DRUG-RELATED CONTENTS IN THE NURSING PROGRAM AT ESPÍRITO SANTO FEDERAL UNIVERSITY: A CRITICAL ANALYSIS

The study was based on the project sponsored by the Organization of American States which wasdeveloped by São Paulo Federal University College of Nursing aiming at analyzing the alcohol- and drug-relatedcourse contents taught in undergraduate nursing programs in Brazil. Its purpose was to evaluate teachingconditions concerning this theme in the undergraduate nursing program at Espírito Santo Federal Universitythrough a descriptive survey applied to 86 nursing students. To 95% of the students, the problem related to theconsumption of alcohol and drugs is a theme of great interest. The inclusion of these themes in nursing programsis a facilitating condition for the education of nurses in this area

Spin Transfer Torques in MnSi at Ultra-low Current Densities

Spin manipulation using electric currents is one of the most promising directions in the field of spintronics. We used neutron scattering to observe the influence of an electric current on the magnetic structure in a bulk material. In the skyrmion lattice of MnSi, where the spins form a lattice of magnetic vortices similar to the vortex lattice in type II superconductors, we observe the rotation of the diffraction pattern in response to currents which are over five orders of magnitude smaller than those typically applied in experimental studies on current-driven magnetization dynamics in nanostructures. We attribute our observations to an extremely efficient coupling of inhomogeneous spin currents to topologically stable knots in spin structures

No observed effect of homologous recombination on influenza C virus evolution

The occurrence of homologous recombination in influenza viruses has been under some debate recently. To determine the extent of homologous recombination in influenza C virus, recombination analyses of all available gene sequences of influenza C virus were carried out. No recombination signal was found. With the previous evidence in influenza A and B viruses, it seems that homologous recombination has minimal or no effect on influenza virus evolution

About the strength of correlation effects in the electronic structure of iron

The strength of electronic correlation effects in the spin-dependent electronic structure of ferromagnetic bcc Fe(110) has been investigated by means of spin and angle-resolved photoemission spectroscopy. The experimental results are compared to theoretical calculations within the three-body scattering approximation and within the dynamical mean-field theory, together with one-step model calculations of the photoemission process. This comparison indicates that the present state of the art many-body calculations, although improving the description of correlation effects in Fe, give too small mass renormalizations and scattering rates thus demanding more refined many-body theories including non-local fluctuations.Comment: 4 pages, 4 figure