1,751 research outputs found
Direct determination of molybdenum in polyvitaminic tablets by voltammetry in non-aqueous media.
Adsorptive stripping voltammetry carried out in a homogeneous ternary solvent composed of N,N-dimethylformamide, water and ethanol, with alpha-benzoinoxime (alpha BO) as the complexing agent for Mo(VI) and a 0.5 mol L-1 acetic acid - sodium acetate buffer as supporting electrolyte was successfully used for the determination of molybdenum in polyvitamin-polymineral tablets. Tablet samples were analyzed and the results were compared with those obtained both by graphite furnace atomic absorption and by recovery tests, with good correlations. indicating that this may be considered as an alternative procedure for routine determination of Mo(VI) in pharmaceutical samples.29115315
Evaluating regulatory strategies for mitigating hydrological risk in Brazil through diversification of its electricity mix
Hydroelectricity provides approximately 65% of Brazil’s power generating capacity, making the country vulnerable to droughts, which are becoming increasingly frequent. Current energy law and policy responses to the problem rely on a sectorial approach and prioritise energy security and market regulation. Brazil has opted to increase energy security levels during periods of hydrological variability with national grid interconnection and thermal plants backup. Additionally, Brazil has created the Energy Reallocation Mechanism (MRE) to manage the generators’ financial impacts in times of insufficient water. This policy, however, was unable to avoid the high financial exposure of generators in the spot market during the severe droughts experienced in the period 2013-2017. To explore how a more diversified electricity matrix can contribute to reducing hydrological risk, this article uses Integrated Assessment Modelling (IAM) techniques to analyse future macroeconomic and energy scenarios for Brazil in a global context, aligned with the Brazilian Nationally Determined Contributions (NDC) under the 2015 Paris Agreement on Climate Change. We show that the addition of non-hydro renewables is an advantage from the integrated Water-Energy-Food nexus perspective because it reduces trade-offs amongst the water and energy sectors. Our conclusions suggest that a nexus perspective can provide useful insights on how to design energy laws and policies.Philomathia Foundation; Cambridge Humanities Research Grant
The AFLOW Fleet for Materials Discovery
The traditional paradigm for materials discovery has been recently expanded
to incorporate substantial data driven research. With the intent to accelerate
the development and the deployment of new technologies, the AFLOW Fleet for
computational materials design automates high-throughput first principles
calculations, and provides tools for data verification and dissemination for a
broad community of users. AFLOW incorporates different computational modules to
robustly determine thermodynamic stability, electronic band structures,
vibrational dispersions, thermo-mechanical properties and more. The AFLOW data
repository is publicly accessible online at aflow.org, with more than 1.7
million materials entries and a panoply of queryable computed properties. Tools
to programmatically search and process the data, as well as to perform online
machine learning predictions, are also available.Comment: 14 pages, 8 figure
Usefulness of PCR-based assays to assess drug efficacy in Chagas disease chemotherapy: value and limitations
One major goal of research on Chagas disease is the development of effective chemotherapy to eliminate the infection from individuals who have not yet developed cardiac and/or digestive disease manifestations. Cure evaluation is the more complex aspect of its treatment, often leading to diverse and controversial results. The absence of reliable methods or a diagnostic gold standard to assess etiologic treatment efficacy still constitutes a major challenge. In an effort to develop more sensitive tools, polymerase chain reaction (PCR)-based assays were introduced to detect low amounts of Trypanosoma cruzi DNA in blood samples from chagasic patients, thus improving the diagnosis and follow-up evaluation after chemotherapy. In this article, I review the main problems concerning drug efficacy and criteria used for cure estimation in treated chagasic patients, and the work conducted by different groups on developing PCR methodologies to monitor treatment outcome of congenital infections as well as recent and late chronic T. cruzi infections
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