19 research outputs found

    Effect of reagent type on the froth floatation of Sokoto phosphate ore

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    Effect of reagent type on the froth floatation of Sokoto phosphate ore for its beneficiation has been established. The samples of the Sokoto phosphate mineral ore used for the research work were sourced from mining locations in Dange-Shuni, Bodinga, Yabo, Wurno, and Rabbah Local Government Areas of Sokoto State. Size-Assay analysis conducted on scrubbed Sokoto Phosphates nodules revealed that nodules had a size distribution with 80% passing 29.3 mm. Flotation Tests using AERO704 (fatty Acid), Alkyl Hydroxamates, Melamine as collectors (alone or mixed with diesel), MIBC as frother, Calcium Hydroxide and Sulphuric Acid as pH regulators and Dextrin, Sodium Silicate and Aluminium Chloride as depressants produced poor P2O5 separation in the flotation products due to very poor liberation associated with very fine mineral grains. Based on the results obtained, AERO704 Collector gave the best result with aP2O5 recovery pH of 10

    Effect of particle size on the froth floatation of Sokoto phosphate ore

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    Effect of particle size on the froth floatation of Sokoto phosphate ore for its beneficiation has been investigated and established. The research has been conducted using various reagents, pH(s) at different sieve size fractions. Bench scale flotation tests were carried out on -250+180μm, -180+106μm, -106+75μm, -75+45μm and -45+38μm particle size fractions after screening in order to determine the optimum flotation feed size distribution using 1 liter Denver flotation cell. The results of the scoping flotation studies using a conditioning Pulp Density of 60%Solids, pH9, 800g/t reagent dosage for AERO704 Promoter (Fatty Acid) and flotation pulp density of 28.5% Solids show that +106μm particle size gave the highest assay content of 20.4% P2O5 with a recovery of 76.2% compared to +38μm (19.9%P2O5 and recovery of 43.2%) and +180μm (19.4%P2O5 and 24.1% recovery) in their floats (concentrates) but with no perfect separation as the tailings fraction also contained similar grades with slight differences

    Effect of reagent type on the froth floatation of Sokoto phosphate ore

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    Effect of reagent type on the froth floatation of Sokoto phosphate ore for its beneficiation has been established. The samples of the Sokoto phosphate mineral ore used for the research work were sourced from mining locations in Dange-Shuni, Bodinga, Yabo, Wurno, and Rabbah Local Government Areas of Sokoto State. Size-Assay analysis conducted on scrubbed Sokoto Phosphates nodules revealed that nodules had a size distribution with 80% passing 29.3 mm. Flotation Tests using AERO704 (fatty Acid), Alkyl Hydroxamates, Melamine as collectors (alone or mixed with diesel), MIBC as frother, Calcium Hydroxide and Sulphuric Acid as pH regulators and Dextrin, Sodium Silicate and Aluminium Chloride as depressants produced poor P2O5 separation in the flotation products due to very poor liberation associated with very fine mineral grains. Based on the results obtained, AERO704 Collector gave the best result with aP2O5 recovery pH of 10

    Effect of particle size on the froth floatation of Sokoto phosphate ore

    Get PDF
    Effect of particle size on the froth floatation of Sokoto phosphate ore for its beneficiation has been investigated and established. The research has been conducted using various reagents, pH(s) at different sieve size fractions. Bench scale flotation tests were carried out on -250+180μm, -180+106μm, -106+75μm, -75+45μm and -45+38μm particle size fractions after screening in order to determine the optimum flotation feed size distribution using 1 liter Denver flotation cell. The results of the scoping flotation studies using a conditioning Pulp Density of 60%Solids, pH9, 800g/t reagent dosage for AERO704 Promoter (Fatty Acid) and flotation pulp density of 28.5% Solids show that +106μm particle size gave the highest assay content of 20.4% P2O5 with a recovery of 76.2% compared to +38μm (19.9%P2O5 and recovery of 43.2%) and +180μm (19.4%P2O5 and 24.1% recovery) in their floats (concentrates) but with no perfect separation as the tailings fraction also contained similar grades with slight differences

    Changes in mediators of inflammation and pro-thrombosis after 12 months of dietary modification in adults with metabolic syndrome

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    Objective: This study evaluated the effects of a 12-month dietary modification on indices of inflammation and pro-thrombosis in adults with metabolic syndrome (MS).Materials and methods: This longitudinal study involved 252 adults with MS recruited from the Bodija market, Ibadan and its environs. Participants were placed on 20%, 30% and 50% calories obtained from protein, total fat and carbohydrate respectively and were followed up monthly for 12 months. Anthropometry and blood pressure were measured using standard methods. Fasting plasma glucose (FPG), total cholesterol (TC), triglycerides (TG), high density lipoprotein-cholesterol (HDL-C), fibrinogen, plasminogen activator inhibitor-1 (PAI-1)], interleukin-6 (IL-6) and interleukin-10 (IL-10) were measured using spectrophotometric methods and ELISA as appropriate. Data was analysed using ANCOVA, Student’s t-test, Mann-Whitney U and Wilcoxon signed-rank tests. P-values less than 0.05 were considered significant.Results: After 6 months of dietary modification, there was a significant reduction in waist circumference (WC), while the levels of HDL-C, fibrinogen and PAI-1 were significantly increased when compared with the corresponding baseline values. However, WC and fibrinogen reduced significantly, while HDL-C and IL-10 significantly increased after 12 months of dietary modification as compared with the respective baseline values.Conclusion: Long-term regular dietary modification may be beneficial in ameliorating inflammation and pro-thrombosis in metabolic syndrome.Keywords: Dietary modification, fibrinogen, interleukins, metabolic syndrome, plasminogen activator inhibito

    Samarium doped ceria (SDC) electrolyte modification by sintering aids addition to reducing sintering temperature: a review

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    The solid oxide fuel cell (SOFC) is a promising technology with specific characteristics for generating electricity by using hydrogen and oxidant as fuel. Typically, SOFC’s use Samarium doped Ceria (SDC) as an electrolyte material as the ionic conductivity of SDC was better at lower operating temperatures which are below than 700°C that making it a good option for low and moderate temperature applications for SOFC. However, SDC electrolytes are cannot be densified below 1500°C. If a densified ceria-based electrolyte can be prepared at lower temperatures it can be co-sintered with another electrode component. This simplifies the fabrication process and reduces the cost. Other than that, it can help with porous electrode microstructure control and avoiding phase diffusion and chemical interaction problems. As a result, decreasing the sintering temperature may be another step toward commercialising SOFC technology. The modification of electrolyte by adding sintering aid was found as an effective method to lowering the sintering temperature. This paper, therefore, focuses on reviewing the attempts made to modify SDC electrolyte by adding sintering aid (Li2O, CoO, CuO and FeO) in order to lowering sintering temperature. The studies related to temperature reduction, relative density, the microstructure of grains and conductivity of electrolyte was critically reviewed

    Global burden and strength of evidence for 88 risk factors in 204 countries and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

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    Background: Understanding the health consequences associated with exposure to risk factors is necessary to inform public health policy and practice. To systematically quantify the contributions of risk factor exposures to specific health outcomes, the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 aims to provide comprehensive estimates of exposure levels, relative health risks, and attributable burden of disease for 88 risk factors in 204 countries and territories and 811 subnational locations, from 1990 to 2021. Methods: The GBD 2021 risk factor analysis used data from 54 561 total distinct sources to produce epidemiological estimates for 88 risk factors and their associated health outcomes for a total of 631 risk–outcome pairs. Pairs were included on the basis of data-driven determination of a risk–outcome association. Age-sex-location-year-specific estimates were generated at global, regional, and national levels. Our approach followed the comparative risk assessment framework predicated on a causal web of hierarchically organised, potentially combinative, modifiable risks. Relative risks (RRs) of a given outcome occurring as a function of risk factor exposure were estimated separately for each risk–outcome pair, and summary exposure values (SEVs), representing risk-weighted exposure prevalence, and theoretical minimum risk exposure levels (TMRELs) were estimated for each risk factor. These estimates were used to calculate the population attributable fraction (PAF; ie, the proportional change in health risk that would occur if exposure to a risk factor were reduced to the TMREL). The product of PAFs and disease burden associated with a given outcome, measured in disability-adjusted life-years (DALYs), yielded measures of attributable burden (ie, the proportion of total disease burden attributable to a particular risk factor or combination of risk factors). Adjustments for mediation were applied to account for relationships involving risk factors that act indirectly on outcomes via intermediate risks. Attributable burden estimates were stratified by Socio-demographic Index (SDI) quintile and presented as counts, age-standardised rates, and rankings. To complement estimates of RR and attributable burden, newly developed burden of proof risk function (BPRF) methods were applied to yield supplementary, conservative interpretations of risk–outcome associations based on the consistency of underlying evidence, accounting for unexplained heterogeneity between input data from different studies. Estimates reported represent the mean value across 500 draws from the estimate's distribution, with 95% uncertainty intervals (UIs) calculated as the 2·5th and 97·5th percentile values across the draws. Findings: Among the specific risk factors analysed for this study, particulate matter air pollution was the leading contributor to the global disease burden in 2021, contributing 8·0% (95% UI 6·7–9·4) of total DALYs, followed by high systolic blood pressure (SBP; 7·8% [6·4–9·2]), smoking (5·7% [4·7–6·8]), low birthweight and short gestation (5·6% [4·8–6·3]), and high fasting plasma glucose (FPG; 5·4% [4·8–6·0]). For younger demographics (ie, those aged 0–4 years and 5–14 years), risks such as low birthweight and short gestation and unsafe water, sanitation, and handwashing (WaSH) were among the leading risk factors, while for older age groups, metabolic risks such as high SBP, high body-mass index (BMI), high FPG, and high LDL cholesterol had a greater impact. From 2000 to 2021, there was an observable shift in global health challenges, marked by a decline in the number of all-age DALYs broadly attributable to behavioural risks (decrease of 20·7% [13·9–27·7]) and environmental and occupational risks (decrease of 22·0% [15·5–28·8]), coupled with a 49·4% (42·3–56·9) increase in DALYs attributable to metabolic risks, all reflecting ageing populations and changing lifestyles on a global scale. Age-standardised global DALY rates attributable to high BMI and high FPG rose considerably (15·7% [9·9–21·7] for high BMI and 7·9% [3·3–12·9] for high FPG) over this period, with exposure to these risks increasing annually at rates of 1·8% (1·6–1·9) for high BMI and 1·3% (1·1–1·5) for high FPG. By contrast, the global risk-attributable burden and exposure to many other risk factors declined, notably for risks such as child growth failure and unsafe water source, with age-standardised attributable DALYs decreasing by 71·5% (64·4–78·8) for child growth failure and 66·3% (60·2–72·0) for unsafe water source. We separated risk factors into three groups according to trajectory over time: those with a decreasing attributable burden, due largely to declining risk exposure (eg, diet high in trans-fat and household air pollution) but also to proportionally smaller child and youth populations (eg, child and maternal malnutrition); those for which the burden increased moderately in spite of declining risk exposure, due largely to population ageing (eg, smoking); and those for which the burden increased considerably due to both increasing risk exposure and population ageing (eg, ambient particulate matter air pollution, high BMI, high FPG, and high SBP). Interpretation: Substantial progress has been made in reducing the global disease burden attributable to a range of risk factors, particularly those related to maternal and child health, WaSH, and household air pollution. Maintaining efforts to minimise the impact of these risk factors, especially in low SDI locations, is necessary to sustain progress. Successes in moderating the smoking-related burden by reducing risk exposure highlight the need to advance policies that reduce exposure to other leading risk factors such as ambient particulate matter air pollution and high SBP. Troubling increases in high FPG, high BMI, and other risk factors related to obesity and metabolic syndrome indicate an urgent need to identify and implement interventions. Funding: Bill & Melinda Gates Foundation

    Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021

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    Background: Estimates of demographic metrics are crucial to assess levels and trends of population health outcomes. The profound impact of the COVID-19 pandemic on populations worldwide has underscored the need for timely estimates to understand this unprecedented event within the context of long-term population health trends. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides new demographic estimates for 204 countries and territories and 811 additional subnational locations from 1950 to 2021, with a particular emphasis on changes in mortality and life expectancy that occurred during the 2020–21 COVID-19 pandemic period. Methods: 22 223 data sources from vital registration, sample registration, surveys, censuses, and other sources were used to estimate mortality, with a subset of these sources used exclusively to estimate excess mortality due to the COVID-19 pandemic. 2026 data sources were used for population estimation. Additional sources were used to estimate migration; the effects of the HIV epidemic; and demographic discontinuities due to conflicts, famines, natural disasters, and pandemics, which are used as inputs for estimating mortality and population. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate under-5 mortality rates, which synthesised 30 763 location-years of vital registration and sample registration data, 1365 surveys and censuses, and 80 other sources. ST-GPR was also used to estimate adult mortality (between ages 15 and 59 years) based on information from 31 642 location-years of vital registration and sample registration data, 355 surveys and censuses, and 24 other sources. Estimates of child and adult mortality rates were then used to generate life tables with a relational model life table system. For countries with large HIV epidemics, life tables were adjusted using independent estimates of HIV-specific mortality generated via an epidemiological analysis of HIV prevalence surveys, antenatal clinic serosurveillance, and other data sources. Excess mortality due to the COVID-19 pandemic in 2020 and 2021 was determined by subtracting observed all-cause mortality (adjusted for late registration and mortality anomalies) from the mortality expected in the absence of the pandemic. Expected mortality was calculated based on historical trends using an ensemble of models. In location-years where all-cause mortality data were unavailable, we estimated excess mortality rates using a regression model with covariates pertaining to the pandemic. Population size was computed using a Bayesian hierarchical cohort component model. Life expectancy was calculated using age-specific mortality rates and standard demographic methods. Uncertainty intervals (UIs) were calculated for every metric using the 25th and 975th ordered values from a 1000-draw posterior distribution. Findings: Global all-cause mortality followed two distinct patterns over the study period: age-standardised mortality rates declined between 1950 and 2019 (a 62·8% [95% UI 60·5–65·1] decline), and increased during the COVID-19 pandemic period (2020–21; 5·1% [0·9–9·6] increase). In contrast with the overall reverse in mortality trends during the pandemic period, child mortality continued to decline, with 4·66 million (3·98–5·50) global deaths in children younger than 5 years in 2021 compared with 5·21 million (4·50–6·01) in 2019. An estimated 131 million (126–137) people died globally from all causes in 2020 and 2021 combined, of which 15·9 million (14·7–17·2) were due to the COVID-19 pandemic (measured by excess mortality, which includes deaths directly due to SARS-CoV-2 infection and those indirectly due to other social, economic, or behavioural changes associated with the pandemic). Excess mortality rates exceeded 150 deaths per 100 000 population during at least one year of the pandemic in 80 countries and territories, whereas 20 nations had a negative excess mortality rate in 2020 or 2021, indicating that all-cause mortality in these countries was lower during the pandemic than expected based on historical trends. Between 1950 and 2021, global life expectancy at birth increased by 22·7 years (20·8–24·8), from 49·0 years (46·7–51·3) to 71·7 years (70·9–72·5). Global life expectancy at birth declined by 1·6 years (1·0–2·2) between 2019 and 2021, reversing historical trends. An increase in life expectancy was only observed in 32 (15·7%) of 204 countries and territories between 2019 and 2021. The global population reached 7·89 billion (7·67–8·13) people in 2021, by which time 56 of 204 countries and territories had peaked and subsequently populations have declined. The largest proportion of population growth between 2020 and 2021 was in sub-Saharan Africa (39·5% [28·4–52·7]) and south Asia (26·3% [9·0–44·7]). From 2000 to 2021, the ratio of the population aged 65 years and older to the population aged younger than 15 years increased in 188 (92·2%) of 204 nations. Interpretation: Global adult mortality rates markedly increased during the COVID-19 pandemic in 2020 and 2021, reversing past decreasing trends, while child mortality rates continued to decline, albeit more slowly than in earlier years. Although COVID-19 had a substantial impact on many demographic indicators during the first 2 years of the pandemic, overall global health progress over the 72 years evaluated has been profound, with considerable improvements in mortality and life expectancy. Additionally, we observed a deceleration of global population growth since 2017, despite steady or increasing growth in lower-income countries, combined with a continued global shift of population age structures towards older ages. These demographic changes will likely present future challenges to health systems, economies, and societies. The comprehensive demographic estimates reported here will enable researchers, policy makers, health practitioners, and other key stakeholders to better understand and address the profound changes that have occurred in the global health landscape following the first 2 years of the COVID-19 pandemic, and longer-term trends beyond the pandemic. Funding: Bill & Melinda Gates Foundation

    INFLUENCE OF MARCIA’S MORATORIUM AND FORECLOSURE EGO IDENTITY STATUSES ON READING ATTITUDE OF STUDENTS IN SECONDARY SCHOOLS IN TANGAZA AND NEIGHBOURING AREAS IN SOKOTO STATE, NIGERIA

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    The paper studied how identity statuses of moratorium and foreclosure influenced the reading attitude of adolescent students in secondary schools in Tangaza and neighbouring areas. Correlational descriptive research design was used for the study. Six research questions and two hypotheses were formulated. A total of six sub-hypotheses were tested on Microsoft Excel software and www.statskingdom.com. The eleven senior secondary schools located in Tangaza, Silame, and Binji local governments formed the population of the survey. A three--stage sampling technique was used, consisting of stratified, purposive, and simple random sampling techniques. The sample for the study was 164 generated from three randomly selected schools; Instruments used in the research were the 16-item Ego Identity Scale (Short) (Greg, 2008) and the Reading Attitude Questionnaire adapted by Akhmetovaa, Imambayevab, and Csapo (2022). Pearson Product Moment Correlation (PPMC) was used to test the hypotheses. Results showed there was no significant relationship between moratorium and foreclosure ego identity statuses and reading attitude of the samples. The study recommended among others that parents, guardians and teachers should consistently guide and encourage adolescents to explore various options in different aspects of life and be committed to such according to their goals and aspirations as they develop into adults; students however should be encouraged by their teachers and parents to develop positive reading attitude as that is part of what lead to identity achievement

    TLC analysis and antioxidant activity of garden egg leaves

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    The Solanum melongena is used traditionally to treat different diseases such as cancer, atherosclerosis, and inflammation. This study is aimed at investigating the thin-layer chromatography analysis and antioxidant activity of n-hexane, acetone and methanol leaves extract of Solanum melongena. Sequential extraction with solvents of increasing polarity was carried out using the n-hexane, ethyl acetate and methanol. The thin-layer chromatography of the extracts carried out with different solvent system. Antioxidant activity was evaluated quantitatively using DPPH (2, 2-diphenyl-2-picrylhydrazyl) for its free radical scavenging ability. The results of thin-layer chromatography revealed some spots with Rf values in the respective extracts, n-hexane (0.31, 0.42, 0.59, 0.65, 0.72, 0.85, 0.92), acetone (0.97, 0.92, 0.88 and 0.59) and methanol (0.72, 0.83, 0.86, 0.94 and 0.96). The extracts exhibit strong antioxidant activities as radical scavengers, indicating that they have strong proton donating abilities. The results from this research show credence to the traditional application of the plant. Further research is recommended on the isolation and characterization of the antioxidant compounds from the plant. Key words: DPPH (2, 2-diphenyl-2-picrylhydrazyl), Thin layer chromatography, Reactive Oxygen Species (ROS) &nbsp
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