47 research outputs found

    Evaluation of physico-chemical properties of re-refined lubricating oils obtained from fabricated packed bed reactor

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    This study aimed at fabricating a packed bed reactor (PBR) and evaluating its performance on improving physico-chemical properties of used lubricating oils. The sorbent used was a composite of bentonite, limestone, diatomite, quartz, and wood charcoal in the same ratio by mass. Samples of used lubricating oils from two brands (Mobil Super SAE 20W-50 and Total Quartz 5000 SAE 20W-50) were run through the fabricated PBR. The mean values of the analyzed physico-chemical parameters (kinematic viscosity, viscosity index, flash point, pour point, acid number, base number, iodine value, ash content, density, and refractive index) of the exuded (treated) oils were compared with those of used and virgin oils of the same brand. Apart from the iodine value, the mean values obtained for the treated oil samples are close to those of virgin oil samples. Thet-test results indicated that most of the parameters showed significant difference between their mean values in the used oils indicating distinct properties and hence, good treatment effects, while a good number showed no significant difference between their mean values in the treated Mobil and treated Total oils, indicating similar properties and that the treatment had similar effects on the two brands of oils. Also, various results of cross plots hadR 2 values greater than 0.96, indicating high linear relationships of the impact of the treatment on the various oil samples. The overall results established the high effectiveness of the fabricated PBR for the treatment of used lubricating oil

    Removal of metals from flat lubricating oils using a fabricated packed-bed reactor

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    Packed bed reactor (PBR) was fabricated and its performance in removing metals from used (flat) lubricating oils was evaluated. A blend of locally produced diatomaceous materials was employed as sorbent. Flat lubricating oils from two brands (Mobil Super SAE-20W-50 and Total Quartz 5000 SAE-20W-50) were run through the PBR. Concentrations of the analysed metals in the used and treated oils were measured using Atomic Absorption Spectrophotometer and the results compared with those of unused (virgin) oils. Zinc, Mg, Ca, Na and K were detected in virgin oils; while all the analysed metals were detected in the treated and used oils but are of higher concentrations in the used oils. Cross plots have R2 values > 0.96, indicating high linear relationships of the impact of the treatment on the used oils. T-test results indicated that most of the metals showed significant differences between the mean values of the treated and used oils, indicating good treatment effects; while most of them indicated no significant differences between the mean values of the brands of oils used, indicating similar treatment effects on the two brands of oils. These results confirmed the high efficacy of the fabricated PBR for the purpose of recycling used oils

    INTRODUCTION OF SOIL TEST KIT TO SMALL-HOLDER COCOA FARMERS IN SOUTH-WESTERN NIGERIA

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    ABSTRACT Soil nutrients depletion of cocoa plantations is one of the causes of low cocoa production in Nigeria. Soil testing to determine the appropriate type and rate of fertilizer to boost cocoa bean yield suggests itself. Conventional soil testing is not within the reach of smallholder cocoa farmers because of its cost and other logistics but soil testing is necessary to avert negative consequences of blanket fertilizer recommendation. Therefore the objective of this study is to introduce an affordable soil test kit for soil testing to smallholders cocoa farmers. The study was carried out in Ondo and Osun States of Nigeria. Multi-stage random sampling technique was used to select eighty two cocoa farmers from the study area. Information was collected from the selected cocoa farmers with the aid of structured questionnaire and the data were analysed using descriptive statistics. The result shows that only 20.73% of the respondent farmers carry out soil test on their farms while 85.36% of the farmers know the relevance of soil test. The result also revealed that 98.78% of the farmers are ready to acquire the soil test kit. The study therefore recommends that (i) The soil test kit should be included among the subsidized inputs that government gives to farmers from time to time and (ii) private entrepreneurs could also procure and make the kits available to the farmers

    Development of Bioinformatics Infrastructure for Genomics Research in H3Africa

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    Background: Although pockets of bioinformatics excellence have developed in Africa, generally, large-scale genomic data analysis has been limited by the availability of expertise and infrastructure. H3ABioNet, a pan-African bioinformatics network, was established to build capacity specifically to enable H3Africa (Human Heredity and Health in Africa) researchers to analyze their data in Africa. Since the inception of the H3Africa initiative, H3ABioNet’s role has evolved in response to changing needs from the consortium and the African bioinformatics community. Objectives: H3ABioNet set out to develop core bioinformatics infrastructure and capacity for genomics research in various aspects of data collection, transfer, storage, and analysis. Methods and Results: Various resources have been developed to address genomic data management and analysis needs of H3Africa researchers and other scientific communities on the continent. NetMap was developed and used to build an accurate picture of network performance within Africa and between Africa and the rest of the world, and Globus Online has been rolled out to facilitate data transfer. A participant recruitment database was developed to monitor participant enrollment, and data is being harmonized through the use of ontologies and controlled vocabularies. The standardized metadata will be integrated to provide a search facility for H3Africa data and biospecimens. Because H3Africa projects are generating large-scale genomic data, facilities for analysis and interpretation are critical. H3ABioNet is implementing several data analysis platforms that provide a large range of bioinformatics tools or workflows, such as Galaxy, the Job Management System, and eBiokits. A set of reproducible, portable, and cloud-scalable pipelines to support the multiple H3Africa data types are also being developed and dockerized to enable execution on multiple computing infrastructures. In addition, new tools have been developed for analysis of the uniquely divergent African data and for downstream interpretation of prioritized variants. To provide support for these and other bioinformatics queries, an online bioinformatics helpdesk backed by broad consortium expertise has been established. Further support is provided by means of various modes of bioinformatics training. Conclusions: For the past 4 years, the development of infrastructure support and human capacity through H3ABioNet, have significantly contributed to the establishment of African scientific networks, data analysis facilities, and training programs. Here, we describe the infrastructure and how it has affected genomics and bioinformatics research in Africa

    On the differences in the vertical distribution of modeled aerosol optical depth over the southeastern Atlantic

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    The southeastern Atlantic is home to an expansive smoke aerosol plume overlying a large cloud deck for approximately a third of the year. The aerosol plume is mainly attributed to the extensive biomass burning activities that occur in southern Africa. Current Earth system models (ESMs) reveal significant differences in their estimates of regional aerosol radiative effects over this region. Such large differences partially stem from uncertainties in the vertical distribution of aerosols in the troposphere. These uncertainties translate into different aerosol optical depths (AODs) in the planetary boundary layer (PBL) and the free troposphere (FT). This study examines differences of AOD fraction in the FT and AOD differences among ESMs (WRF-CAM5, WRF-FINN, GEOS-Chem, EAM-E3SM, ALADIN, GEOS-FP, and MERRA-2) and aircraft-based measurements from the NASA ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) field campaign. Models frequently define the PBL as the well-mixed surface-based layer, but this definition misses the upper parts of decoupled PBLs, in which most low-level clouds occur. To account for the presence of decoupled boundary layers in the models, the height of maximum vertical gradient of specific humidity profiles from each model is used to define PBL heights. Results indicate that the monthly mean contribution of AOD in the FT to the total-column AOD ranges from 44 % to 74 % in September 2016 and from 54 % to 71 % in August 2017 within the region bounded by 25∘ S–0∘ N–S and 15∘ W–15∘ E (excluding land) among the ESMs. ALADIN and GEOS-Chem show similar aerosol plume patterns to a derived above-cloud aerosol product from the Moderate Resolution Imaging Spectroradiometer (MODIS) during September 2016, but none of the models show a similar above-cloud plume pattern to MODIS in August 2017. Using the second-generation High Spectral Resolution Lidar (HSRL-2) to derive an aircraft-based constraint on the AOD and the fractional AOD, we found that WRF-CAM5 produces 40 % less AOD than those from the HSRL-2 measurements, but it performs well at separating AOD fraction between the FT and the PBL. AOD fractions in the FT for GEOS-Chem and EAM-E3SM are, respectively, 10 % and 15 % lower than the AOD fractions from the HSRL-2. Their similar mean AODs reflect a cancellation of high and low AOD biases. Compared with aircraft-based observations, GEOS-FP, MERRA-2, and ALADIN produce 24 %–36 % less AOD and tend to misplace more aerosols in the PBL. The models generally underestimate AODs for measured AODs that are above 0.8, indicating their limitations at reproducing high AODs. The differences in the absolute AOD, FT AOD, and the vertical apportioning of AOD in different models highlight the need to continue improving the accuracy of modeled AOD distributions. These differences affect the sign and magnitude of the net aerosol radiative forcing, especially when aerosols are in contact with clouds.</p

    Baricitinib in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial and updated meta-analysis

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    Background: We aimed to evaluate the use of baricitinib, a Janus kinase (JAK) 1–2 inhibitor, for the treatment of patients admitted to hospital with COVID-19. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple possible treatments in patients hospitalised with COVID-19 in the UK. Eligible and consenting patients were randomly allocated (1:1) to either usual standard of care alone (usual care group) or usual care plus baricitinib 4 mg once daily by mouth for 10 days or until discharge if sooner (baricitinib group). The primary outcome was 28-day mortality assessed in the intention-to-treat population. A meta-analysis was done, which included the results from the RECOVERY trial and all previous randomised controlled trials of baricitinib or other JAK inhibitor in patients hospitalised with COVID-19. The RECOVERY trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936) and is ongoing. Findings: Between Feb 2 and Dec 29, 2021, from 10 852 enrolled, 8156 patients were randomly allocated to receive usual care plus baricitinib versus usual care alone. At randomisation, 95% of patients were receiving corticosteroids and 23% were receiving tocilizumab (with planned use within the next 24 h recorded for a further 9%). Overall, 514 (12%) of 4148 patients allocated to baricitinib versus 546 (14%) of 4008 patients allocated to usual care died within 28 days (age-adjusted rate ratio 0·87; 95% CI 0·77–0·99; p=0·028). This 13% proportional reduction in mortality was somewhat smaller than that seen in a meta-analysis of eight previous trials of a JAK inhibitor (involving 3732 patients and 425 deaths), in which allocation to a JAK inhibitor was associated with a 43% proportional reduction in mortality (rate ratio 0·57; 95% CI 0·45–0·72). Including the results from RECOVERY in an updated meta-analysis of all nine completed trials (involving 11 888 randomly assigned patients and 1485 deaths) allocation to baricitinib or another JAK inhibitor was associated with a 20% proportional reduction in mortality (rate ratio 0·80; 95% CI 0·72–0·89; p<0·0001). In RECOVERY, there was no significant excess in death or infection due to non-COVID-19 causes and no significant excess of thrombosis, or other safety outcomes. Interpretation: In patients hospitalised with COVID-19, baricitinib significantly reduced the risk of death but the size of benefit was somewhat smaller than that suggested by previous trials. The total randomised evidence to date suggests that JAK inhibitors (chiefly baricitinib) reduce mortality in patients hospitalised for COVID-19 by about one-fifth. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research
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