34 research outputs found

    Tensile and Water Absorbing Properties of Natural Fibre Reinforced Plastic Composites from Waste Polystyrene and Rice Husk

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    This paper presents a study on the development of Natural fibre reinforced plastic composite from the waste polystyrene and rice husk, a new class of composites consisting of polystyrene based resin reinforced with rice husk fibre. Four different sets of polystyrene/rice husk composites were fabricated with addition of 10, 20, 30 and 40 wt% of rice husk particulates. Tensile and water absorbing properties of these composites were evaluated as per ASTM standard. Tests for water absorption were performed by immersing the samples in a bath of distilled water at room temperature and water uptake was measured gravimetrically along the process. It was observed that young modulus, force at peak, percentage water absorbed and diffusion coefficient of the composite increased while elongation at peak force decreased with addition of rice husk in the PBR matrix. The highest values of young modulus, force at peak, diffusion coefficients and elongation at peak force at 40 % rice husk content are: 365 N/mm2, 562 N, 1.77E-04 mm2/s and 0.76 % respectively. The recycled rice husk in combination with the PBR has produced plastic composite with moderate tensile and water absorbing properties applicable in various application

    Response surface modelling and optimisation of biodiesel production from Manilkara Zapota L. seed oil

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    724-729Biodiesel production from non-edible oils is one of the prominent research avenues being exploited in recent times to achieve energy and environmental sustainability. The aim of this study is to model and optimise the production of biodiesel from the reaction of ethanol with Sapota (Manilkara Zapota L.) seed oil using potassium hydroxide (KOH) as catalyst. A quadratic response surface model has been developed and validated. Analysis of variance (ANOVA) reveals that the model is significant. The standard deviation is 3.76% and the coefficient of determination (R2) is 0.8438. Numerical optimisation reveal that the optimal biodiesel yield of 89.57% can be achieved at an ethanol to oil molar ratio is 6.58, catalyst amount of 1.07 wt% and temperature of 64.77C. Parametric studies reveal that the yield of biodiesel initially increases with increasing ethanol-oil ratio and catalyst amount but drops off gradually beyond the region of optimality. Temperature has a slight positive effect on the process

    Development of high-performance self compacting concrete using eggshell powder and blast furnace slag as partial cement replacement

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    This study aimed to examine the properties of self-compacting concrete (SCC) developed using eggshell powder (ESP) and granulated ground blast furnace slag (GGBFS) as partial cement replacement. The coarse aggregate impact value was 21.6% and the water absorption of the fine aggregates was 24 wt%. 10 wt% partial replacement was optimal for flow-ability and workability. SCC with 20 wt% partial replacements had the highest compressive strength at 41.34 kN/mm2 and 42.4 kN/mm2 for ESP and GGBFS respectively after 28 days of curing. SCC with 20 wt% partial replacements had the highest flexural strength at 3.2 kN/mm2 for both ESP and GGBFS after 28 days of curing. From the microstructural analysis, partial replacement with mineral admixtures improved the interfacial interactions between constituents of the concrete and GGBFS SCC gave a better interfacial interaction between the concrete constituents than ESP SCC. In summary, GGBFS had better fresh, hard and microstructural properties than ESP

    High-Performance Concrete Incorporating Almond Leave Ash as Supplementary Cementing Material

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    High-Performance Concrete (HPC) offers greater strength and resilience compared to conventional concrete. Almond leaves frequently clog areas where they are planted and have no recognized commercial value. In this research, Almond Leaf Ash (ALA) was included in HPC in percentages ranging from 0, 5, 10, 15, 20% as a cement additive. Concrete specimens, engineered to possess a minimum strength of 50 N/mm², were poured and underwent water curing for up to 56 days. The workability of the newly mixed concrete was evaluated by analyzing its compacting factor and slump. Furthermore, evaluations were conducted on the density, compressive and split tensile strengths, as well as the internal microstructure of the cured concrete. The workability tests revealed that the concrete stiffened as the proportion of ALA increased. Adding 5% ALA to HPC led to achieving a strength of 56.56 N/mm2 after 56 days of curing, surpassing the expected strength. Meanwhile, incorporating 10% ALA attained the targeted minimum strength of 50 N/mm2. 15% and 20% of the ALA, however, fell short of the minimum strength. The HPC's split tensile strength followed the same pattern. The results were corroborated by examining the microstructure of the HPC, revealing that substituting 5% ALA for cement yielded the highest strength

    Development of high-performance self compacting concrete using eggshell powder and blast furnace slag as partial cement replacement Gender Implications

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    This study aimed to examine the properties of self-compacting concrete (SCC) developed using eggshell powder (ESP) and granulated ground blast furnace slag (GGBFS) as partial cement replacement. The coarse aggregate impact value was 21.6% and the water absorption of the fine aggregates was 24 wt%. 10 wt% partial replacement was optimal for flow-ability and workability. SCC with 20 wt% partial replacements had the highest compressive strength at 41.34 kN/mm2 and 42.4 kN/mm2 for ESP and GGBFS respectively after 28 days of curing. SCC with 20 wt% partial replacements had the highest flexural strength at 3.2 kN/mm2 for both ESP and GGBFS after 28 days of curing. From the microstructural analysis, partial replacement with mineral admixtures improved the interfacial interactions between constituents of the concrete and GGBFS SCC gave a better interfacial interaction between the concrete constituents than ESP SCC. In summary, GGBFS had better fresh, hard and microstructural properties than ESP

    A review on sustainable photocatalytic degradation of agro-organochlorine and organophosphorus water pollutants using biogenic iron and iron oxide-based nanoarchitecture materials

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    DATA AVAILABILITY : No data was used for the research described in the article.Sustainable accessibility and adequate availability of healthy water are preconditions for healthy living and effective uninterrupted ecological networking. However, the presence of organic pollutants like organochlorine (OC) and organophosphorus (OP) compounds in the environment has led to continuous shrinkage in the percentage of clean water available for humanity's basic needs. Interestingly, green nanoparticles biosynthesized using biogenic entities have recently emerged as an appealing choice for photocatalytic degradation of a wide range of pollutants owing to their eco-benignness. Particularly, biogenic iron-based nanoparticles (BIBNPs) have demonstrated unique properties such as ease of fabrication, excellent regenerability, strong redox potential, the ability to absorb a wide range of visible light, and the ability to produce highly reactive oxygen species that can enhance degradation efficiency and low aggregation which are beneficial for the remediation of water contaminants. The ability of BIBNPs to maintain stability and reactivity under various environmental conditions makes them a promising solution for environmental cleanup efforts. This review aims to critically report and empirically juxtapose the efficiency of biogenic iron and iron oxide NPs for photocatalytic degradation of a wide spectrum of OC and OP pollutants in aquatic environments. The work also generously elucidates the potential of BIBNPs as eco-benign and recyclable photocatalysts for the complete mineralization of OC and OP. The study also pragmatically expounded the photocatalytic degradation mechanism and presented frontiers and future research directions in circular economy, financial analysis, artificial intelligence integration, and hybrid technology. It was discovered that the most prevalent end mineralization products were CO2 and H2O, that the least amount of time needed for degradation was just five minutes, and plant extract was the most widely used bio-reductant for the bio-fabrication of BIBNPs. The greatest degradation efficiency was also found to be 100 % which is a testament to the superior efficacy of BIBNPs.https://www.sciencedirect.com/journal/desalination-and-water-treatmenthj2024ChemistrySDG-06:Clean water and sanitatio

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial

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    Background Post-partum haemorrhage is the leading cause of maternal death worldwide. Early administration of tranexamic acid reduces deaths due to bleeding in trauma patients. We aimed to assess the effects of early administration of tranexamic acid on death, hysterectomy, and other relevant outcomes in women with post-partum haemorrhage. Methods In this randomised, double-blind, placebo-controlled trial, we recruited women aged 16 years and older with a clinical diagnosis of post-partum haemorrhage after a vaginal birth or caesarean section from 193 hospitals in 21 countries. We randomly assigned women to receive either 1 g intravenous tranexamic acid or matching placebo in addition to usual care. If bleeding continued after 30 min, or stopped and restarted within 24 h of the first dose, a second dose of 1 g of tranexamic acid or placebo could be given. Patients were assigned by selection of a numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Participants, care givers, and those assessing outcomes were masked to allocation. We originally planned to enrol 15 000 women with a composite primary endpoint of death from all-causes or hysterectomy within 42 days of giving birth. However, during the trial it became apparent that the decision to conduct a hysterectomy was often made at the same time as randomisation. Although tranexamic acid could influence the risk of death in these cases, it could not affect the risk of hysterectomy. We therefore increased the sample size from 15 000 to 20 000 women in order to estimate the effect of tranexamic acid on the risk of death from post-partum haemorrhage. All analyses were done on an intention-to-treat basis. This trial is registered with ISRCTN76912190 (Dec 8, 2008); ClinicalTrials.gov, number NCT00872469; and PACTR201007000192283. Findings Between March, 2010, and April, 2016, 20 060 women were enrolled and randomly assigned to receive tranexamic acid (n=10 051) or placebo (n=10 009), of whom 10 036 and 9985, respectively, were included in the analysis. Death due to bleeding was significantly reduced in women given tranexamic acid (155 [1·5%] of 10 036 patients vs 191 [1·9%] of 9985 in the placebo group, risk ratio [RR] 0·81, 95% CI 0·65–1·00; p=0·045), especially in women given treatment within 3 h of giving birth (89 [1·2%] in the tranexamic acid group vs 127 [1·7%] in the placebo group, RR 0·69, 95% CI 0·52–0·91; p=0·008). All other causes of death did not differ significantly by group. Hysterectomy was not reduced with tranexamic acid (358 [3·6%] patients in the tranexamic acid group vs 351 [3·5%] in the placebo group, RR 1·02, 95% CI 0·88–1·07; p=0·84). The composite primary endpoint of death from all causes or hysterectomy was not reduced with tranexamic acid (534 [5·3%] deaths or hysterectomies in the tranexamic acid group vs 546 [5·5%] in the placebo group, RR 0·97, 95% CI 0·87-1·09; p=0·65). Adverse events (including thromboembolic events) did not differ significantly in the tranexamic acid versus placebo group. Interpretation Tranexamic acid reduces death due to bleeding in women with post-partum haemorrhage with no adverse effects. When used as a treatment for postpartum haemorrhage, tranexamic acid should be given as soon as possible after bleeding onset. Funding London School of Hygiene & Tropical Medicine, Pfizer, UK Department of Health, Wellcome Trust, and Bill & Melinda Gates Foundation

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

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    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

    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
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