Physicochemical, mineralogy, and thermo-kinetic characterisation of newly discovered nigerian coals under pyrolysis and combustion conditions

In this study, the physicochemical, microstructural, mineralogical, thermal, and kinetic properties of three newly discovered coals from Akunza (AKZ), Ome (OME), and Shiga (SHG) in Nigeria were examined for potential energy recovery. Physicochemical analysis revealed high combustible but low levels of polluting elements. The higher heating values ranged from 18.65 MJ/kg (AKZ) to 26.59 MJ/kg (SHG). Microstructure and mineralogical analyses revealed particles with a rough texture, surface, and glassy lustre, which could be ascribed to metals, quartz, and kaolinite minerals. The major elements (C, O, Si, and Al), along with minor elements (Ca, Cu, Fe, K, Mg, S, and Ti) detected are associated with clays, salts, or the porphyrin constituents of coal. Thermal analysis showed mass loss (ML) ranges from 30.51% to 87.57% and residual mass (RM) from 12.44% to 69.49% under combustion (oxidative) and pyrolysis (non-oxidative) TGA conditions due to thermal degradation of organic matter and macerals (vitrinite, inertinite and liptinite). Kinetic analysis revealed the coals are highly reactive under the oxidative and non-oxidative conditions based on the Coats–Redfern Model. The activation energy (Ea) ranged from 23.81 to 89.56 kJ/mol, whereas the pre-exponential factor (ko) was from 6.77 × 10–4/min to 1.72 × 103/min under pyrolysis and combustion conditions. In conclusion, the coals are practical feedstocks for either energy recovery or industrial applications

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Geochemical, mineralogical, and petrological characteristics of the Cretaceous coal from the middle Benue Trough Basin, Nigeria: implication for coal depositional environments

The Benue Trough Basin (BTB) of Nigeria is geologically and geo-morphologically subdivided into upper, middle, and lower segments. The BTB is the subject of geological research due to its rich coal deposits that have the potential for oil and gas. The purpose of the present study is to examine the origins, depositional environments, and thermal history of the selected coals and the processes that influence their quality. Coal samples from different open cast coal mines in the middle BTB were examined using proximate and ultimate, x-ray diffraction (XRD), x-ray fluorescence (XRF), laser ablation induced coupled plasma (LA-ICPMS), and petrographical analyses. The coal samples contained mainly quartz, kaolinite, and organic carbon. The XRD spectra peaks revealed the triclinic and monoclinic structure of kaolin. The SiO2/Al2O3 ratios confirmed the dominance of quartz and kaolinite. The Ni/Co versus V/Cr, Cu/Zn, and V/Mo values in the studied coals suggest oxic depositional environments, whereas the V/(Ni + V) and V/(V + Cr) values indicate oxic to suboxic conditions. The Ce/Ce∗ values are slightly below 1, which indicates a suboxic depositional environment. Maceral texture is indicative of transformations from sub-bituminous to high volatile C or B bituminous coal. The maceral components and mineral matter (≥10%) of the studied coals imply deposition in the planar margin mire, and a river system of planar margin mire environments, respectively. The high gelification index (GI) and tissue preservation index (TPI) values indicate peat accumulation developed within a wet forest swamp. The ternary diagram of the maceral component suggests deposition in a wet moor environment with intermittent moderate to high flooding episodes. The studied coals are sub-hydrous vitrinite inferring hydrogen-poor and thermally immature characteristics. The low V and Ni contents, low H/C and high O/C, indicate Type Ⅲ terrestrial organic matter with the potential to generate gaseous hydrocarbons. The investigated coals were deposited by the river within telmatic, limnic, and limno-telmatic zones in the planar margin mire depositional environments. Overall, the integrated petrologic and geochemical data used in this study provides a reliable approach for the assessment of coal depositional environments