Production of Metallic Iron from the Pudo Magnetite Ore using End-of-Life Rubber Tyre as Reductant: The Role of an Underlying Ankerite Ore as a Fluxing Agent on Productivity

This research work investigated the nature of a nonmagnetic ore from Pudo in the Upper West Region of Ghana and its fluxing effect on the extent of reduction of the Pudo titaniferous magnetite ore using pulverised samples of charred carbonaceous materials generated from end-of-life vehicle tyres (ELT) as reductants. Reduction studies were conducted on composite pellets of the Pudo titaniferous magnetite iron ore containing fixed amounts of charred ELT and varying amounts (0%, 10%, 15%, 20%, 30%, 40% and 50%) of the nonmagnetic fluxing material in a domestic microwave oven and the extent of reduction was calculated after microwave irradiation for 40 minutes. Analyses by XRF, SEM/EDS and XRD of the nonmagnetic ore revealed an Ankerite type of ore of the form Ca0.95Fe0.95Mn0.1 (CO3)2. From the microwave reduction studies it was observed that premium grade metallic iron could be produced from appropriate blends of the Pudo iron ores using ELT as reductant, with a measured extent of reduction up to 103.8%. Further, the extent of reduction was observed to increase with an increase in the amount of the nonmagnetic fluxing material (Ankerite) that was added as fluxing agent.   Keywords: Ankerite, End-of-life Rubber Tyres, Fluxing Agent, Extent of Reductio

Production of Iron Nuggets from the Akpafu-Todzi Iron Ore and Artisanal Ferrous Slag using Post Consumer Thermosets (Waste Electrical Sockets) as Reductants

AbstractPost-consumer thermosets are difficult to recycle because, unlike thermoplastics, they cannot be remoulded to create other items as a result of the extensive cross-linkages in their structure. The increased production of thermoset blends and composites in recent years has greatly increased the amount of waste materials. However, higher levels of carbon and hydrogen present in thermosets make them a potential reductant in the iron extractive industries. In this research work, postconsumer thermoset was transformed into carbon resource through a charring process. The resulting carbonaceous material from the thermoset was used as reductant in the production of metallic iron from the Akpafu-Todzi iron ore and artisanal slag using the microwave technology through the composite pellet approach at varying firing times. Analyses by XRF, XRD and SEM/EDS showed that the Akpafu Todzi iron ore is comprised of the iron oxides hematite (Fe2O3) and wustite (Fe0.942O), while the artisanal slag was predominantly fayalite (Fe2SiO4). Complete reduction of the ore was attained after 120 min reduction but the maximum extent of reduction was 78.84% for the slag, demonstrating the potential of postconsumer thermosets to function effectively as a reductant in the iron extractive industry. Keywords: Reduction; Akpafu-Todzi Iron Ore; Post Consumer Thermosets; Waste Electrical Socket

Recycling of End-of-Life Polycarbonate as a Carbon Resource in Ironmaking

Globally, millions of end-of-life Polycarbonates (PC) are generated annually. Landfill disposal is one of the primary options for handling end-of-life PCs. There is a possible potential release of Bisphenol-A (BPA) from PC via hydrolysis or leaching when disposed at landfill sites. In this work the use of end-of-life PC as reductant for the production of metallic iron from Mbalam iron oxide was investigated in a horizontal tube furnace through the composite pellet approach. Elemental analysis of the charred PC shows a carbon content of (78.92 wt %) and hydrogen content of (7.07 wt %) which are reasonably above those of various forms of coals and can be recovered for use as reductant in metal extraction processes. Composite pellets of high-grade Mbalam iron ore (assaying ~97 % Fe2O3) with charred end-of-life PC were heated from room temperature to 800 °C and then between 800-1300 °C in a continuous stream of pure argon and the off gas was analysed continuously using an infrared (IR) gas analyser. Elemental analyses of samples of the reduced metal were performed chemically for its oxygen content using a LECO oxygen/nitrogen analyser. Gas emission studies revealed the emission of large volumes of the reductant gas CO along with CO2. It is further demonstrated that end-of-life PC is effective in reducing iron oxide to produce metallic iron with reduction in oxygen content from 30.99 wt % to 0.0372 wt % corresponding to 99.88 % in less than 2400 s

What Makes GPCRs from Different Families Bind to the Same Ligand?

G protein-coupled receptors (GPCRs) are the largest class of cell-surface receptor proteins with important functions in signal transduction and often serve as therapeutic drug targets. With the rapidly growing public data on three dimensional (3D) structures of GPCRs and GPCR-ligand interactions, computational prediction of GPCR ligand binding becomes a convincing option to high throughput screening and other experimental approaches during the beginning phases of ligand discovery. In this work, we set out to computationally uncover and understand the binding of a single ligand to GPCRs from several different families. Three-dimensional structural comparisons of the GPCRs that bind to the same ligand revealed local 3D structural similarities and often these regions overlap with locations of binding pockets. These pockets were found to be similar (based on backbone geometry and side-chain orientation using APoc), and they correlate positively with electrostatic properties of the pockets. Moreover, the more similar the pockets, the more likely a ligand binding to the pockets will interact with similar residues, have similar conformations, and produce similar binding affinities across the pockets. These findings can be exploited to improve protein function inference, drug repurposing and drug toxicity prediction, and accelerate the development of new drugs

Temporal trends in between and within‐country inequalities in caesarean delivery in low‐ and middle‐income countries: a Bayesian analysis

Objective: To provide updated information about between-country variations, temporal trends and changes in inequalities within countries in caesarean delivery (CD) rates. Design: Cross-sectional study of Demographic and Health Survey (DHS) during 1990–2018. Setting: 74 low- and middle-income countries (LMICs). Population: Women 15–49 years of age who had live births in the last 3 years. Methods: Bayesian linear regression analysis was performed and absolute differences were calculated. Main outcome measure: Population-level CD by countries and sociodemographic characteristics of mothers over time. Results: CD rates, based on the latest DHS rounds, varied substantially between the study countries, from 1.5% (95% CI 1.1–1.9%) in Madagascar to 58.9% (95% CI 56.0–61.6%) in the Dominican Republic. Of 62 LMICs with at least two surveys, 57 countries showed a rise in CD during 1990–2018, with the greatest increase in Sierra Leone (19.3%). Large variations in CD rates were observed across mother's wealth, residence, education and age, with a higher rate of CD by the richest and urban mothers. These inequalities have widened in many countries. Stratified analyses suggest greater provisioning of CD by the richest mothers in private facilities and poorest mothers in public facilities