Corrosion Behaviour of a Highly Alloyed Austenitic Alloy UB6 in Contaminated Phosphoric Acid

The influence of temperature (20-80°C) on the electrochemical behaviour of passive films anodically formed on UB6 stainless steel in phosphoric acid solution (5.5 M H3PO4) has been examined by using potentiodynamic curves, electrochemical impedance spectroscopy, and Mott-Schottky analysis. UB6 stainless steel in contaminated phosphoric acid is characterised by high interfacial impedance, thereby, illustrating its high corrosion resistance. The obtained results show that the films behave as n-type and p-type semiconductors in the potential range above and below the flat band potential, respectively. This behaviour is assumed to be the consequence of the semiconducting properties of the iron oxide and chromium oxide regions which compose the passive film

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

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

Is a dense city a healthy city? A preliminary study on the interplay between urban density and air quality in Oran, Algeria

The general consensus is that dense cities are more sustainable. However, high urban density or compact urban form may affect the health of city dwellers, more particularly when compactness is not associated with the provision of mass transit systems. This paper analyses the correlation between urban density indicators and air pollution in Oran (Algeria), a city that suffers a lack of public transport. It assesses the density of green space needed to reduce airborne pollutants in cities. The paper also examines the impacts of exposure to air pollution on respiratory mortality using a quantitative health impact assessment methodology. Findings show that population density and building density strongly correlates with air pollution, due to motorized transport and other human activities (e.g. industries, residential heating or lacking green space). Results indicate that for population density greater than 12100 inhabitants/ha with associated values exceeding 100 for building density and green space density, air pollution levels become higher than 40µg/m3 , exceeding the recommended limit at international level by WHO. In addition, 588 annual premature deaths (95% CI: 529-643), i.e. 0,2% of the total population of the eighteen districts and 3,7% of the total number of deaths, were directly or indirectly related to NOx concentration. This paper concludes that despite the conventional wisdom that more dense cities are more sustainable and healthier, higher density urban areas tend to be associated with poor air quality when there are no mass transit systems.Il est communément admis est que les villes denses sont plus durables. Cependant, une densité urbaine élevée ou une forme urbaine compacte peuvent affecter la santé des citadins, plus particulièrement lorsque la compacité n’est pas associée à un système de transport en commun. Cet article analyse la corrélation entre les indicateurs de densité urbaine et la pollution atmosphérique à Oran (Algérie), une ville qui souffre encore d’un manque de transports en commun. Il évalue la densité des espaces verts nécessaires pour réduire les polluants atmosphériques générés dans les villes et examine les impacts de l’exposition aux valeurs limites de la pollution atmosphérique sur la mortalité respiratoire, en utilisant une méthodologie d’évaluation quantitative de l’impact sur la santé. Les résultats montrent que la densité de la population et du cadre bâties fortement corrélée à la pollution atmosphérique en raison du transport motorisé et d’autres activités humaines comme les industries, le chauffage résidentiel et le manque d’espaces verts. Les résultats indiquent que pour une densité de population supérieure à 12 100 habitants/ha et des valeurs excédant 100 pour la densité du bâti et des espaces verts, les niveaux de pollution de l’air deviennent supérieurs à la limite d’exposition recommandée au niveau international par l’OMS. En outre, 588 décès prématurés annuels, soit 0,2 % de la population totale des dix-huit districts et 3,7 % du nombre total de décès, étaient directement ou indirectement liés à la concentration de NOx. Cet article conclut qu’en dépit du consensus conventionnel selon lequel les villes plus denses sont plus durables et plus saines, les zones urbaines à forte densité tendent à être associées à une mauvaise qualité de l’air lorsqu’elles ne bénéficient pas d’un système de transport en commun.Existe en general un consenso que las ciudades con mayor densidad son más sostenibles. Sin embargo, una alta densidad urbana o forma compacta pueden afectar la salud de los habitantes de esta, particularmente cuando la compacidad no está asociada con sistemas de transporte público robustos. En tal contexto el análisis integral de los efectos de la densidad urbana, áreas verdes, contaminación del aire y la mortalidad respiratoria relacionada a esta, no es totalmente abordada en la literatura. En este sentido, este artículo analiza la correlación entre indicadores de densidad urbana y contaminación del aire en dieciocho distritos de la ciudad de Orán, la cual carece de un transporte público robusto. Así, se evalúa la densidad de espacios verdes necesaria para reducir los contaminantes atmosféricos generados por la densidad urbana, examinando también los impactos de la exposición a valores límites de contaminación del aire en la mortalidad respiratoria a partir de una metodología de evaluación cuantitativa del impacto en la salud. Los resultados muestran que la densidad de la población seguida de la densidad de construcción se correlacionan fuertemente con la contaminación del aire debido al transporte motorizado y otras como presencia de industrias, calefacción residencial y falta de espacios verdes. En efecto, se observa que valores superiores a 12100 habitantes/ha para la densidad de población y sobre 100 para los espacios verdes y superficie construida, los niveles de contaminación del aire superan los 40 µg/m3 y, por lo tanto, se posicionan sobre el límite de exposición internacional recomendado. En tal contexto 588 fallecimientos prematuros anuales (IC 95%: 529-643), es decir, el 0,2% de la población total de los dieciocho distritos y el 3,7% del total de decesos, estuvieron directa o indirectamente vinculados con la concentración de NOx. Se concluye que, a pesar del consenso que las ciudades más densas son más sostenibles y saludables, las áreas urbanas de mayor densidad tienden a presentar una mala calidad del aire cuando no existe un sistema de transporte público robusto

Evaluation of Physicochemical Properties and Sensory Qualities of Pasta Enriched with Freeze-Dried Sweet Whey

For food industry, the production of functional pasta from non-conventional raw materials represents a challenge. This study aims to evaluate the potential of animal proteins of freeze-dried whey as a component for pasta production and its effect on the pasta qualities and consumer acceptance. Sweet whey was freeze-dried, then directly incorporated to pasta at a 20% level. Two pasta types (pasta non-enriched vs. enriched with whey powder) were manufactured following a small-scale pilot procedure, and then evaluated for their physicochemical and sensory qualities. Results of all analyses (whey, semolina and pasta) met the standards according to international legislation; however, the characteristics of enriched pasta differed. Whey addition significantly increased ash, proteins content, optimal cooking time and water uptake (P < 0.05); it significantly decreased moisture levels, colour parameters (CIE system: a* redness, b* yellowness) and the swelling index (P < 0.05). Sensory analysis revealed that overall sensory and product quality of enriched pasta was not affected by whey fortification and it was found acceptable by panelists. This study points out that whey powder could be used for the functional pasta production to increase proteins levels

Experimental and Theoretical Tests on the Corrosion Protection of Mild Steel in Hydrochloric Acid Environment by the Use of Pyrazole Derivative

In this study, 1,5-diallyl-1H-pyrazolo [3,4-d] pyrimidin-4 (5H)-one (PPD) was evaluated as an anticorrosion agent for mild steel (MS) in 1 M HCl. The analysis was performed by weight loss (WL), potentiodynamic polarization measurement, and electrochemical impedance spectroscopy (EIS). The Tafel polarization showed that PPD is a mixed-type inhibitor and reaches 94% of the protective efficiency at 10−3 M. EIS results indicated that the resistance to charge transfer increases with increasing inhibitor concentration and the corrosion of MS is controlled by a charge transfer process. The inhibitor adsorption on the MS surface obeyed the Langmuir’s adsorption isotherm. Thermodynamic parameters were calculated to elaborate the corrosion inhibition mechanism. The micrographic analysis revealed the existence of a barrier layer on the electrode surface with the presence of PPD. Theoretical examinations performed by electronic/atomic computer simulations confirmed that the obtained results were found to be consistent with experimental findings

Experimental and DFT Atomistic Insights into the Mechanism of Corrosion Protection of Low-Carbon Steel in an Acidic Medium by Polymethoxyflavones from Citrus Peel Waste

Developing green anticorrosive films is gaining great attention in science and engineering. Citrus fruit peels are mainly discarded as waste, although they can be an excellent repository of phytochemicals, that can be exploited as mitigating agents for corrosion. Herein, we report the high anticorrosion activity of a citrus extract for low-carbon steel in 1 M HCl solution at different temperatures. The main extract constituents were identified by MS and NMR. Two polymethoxyflavones (PMFs), namely nobiletin and heptamethoxyflavone, were identified as major constituents of the extract and the crude PMFs-based extract was investigated for corrosion protection. Using potentiodynamic polarization, weight loss and electrochemical impedance spectroscopy (EIS) methods, this extract revealed improved inhibition efficiency of 94%. The inhibition mechanism was elucidated by considering electrochemical kinetics and adsorption thermodynamics. SEM and UV–vis supported the electrochemical results. PMFs-based extract acted as a mixed-type inhibitor with a Langmuir model of adsorption. Importantly, DFT simulations provided atomic-level insights into the inhibition mechanism and unraveled donor-acceptor interactions between the methoxy groups of PMFs and iron atoms, facilitating the formation of a stable inhibition adsorption layer, and thus supporting the experimental findings. In addition to the physical barrier effect of PMF inhibitor, π -back bonding effect between PMF and steel was suggested

Experimental and computational aspects of green corrosion inhibition for low carbon steel in HCl environment using extract of Chamaerops humilis fruit waste

[EN] The inhibition effect of a methanolic extract of Chamaerops humilis (CHFE) on the corrosion of low-carbon steel in 1 M HCl solution was evaluated by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy. The extract was obtained from the fruit seeds by the Soxhlet extraction method. The CHFE demonstrated promising anticorrosive performance, and the inhibition efficiency increased with increasing the concentration of the extract, peaking at 93% at only 500 ppm. Importantly, the inhibitor exhibited a remarkable stability after 48 h of immersion, reaching an efficiency of 94%. The extract revealed a mixed-type inhibitive behavior. In addition, elevating the solution temperature showed a negative influence on the inhibition efficacy. Thermodynamic parameters suggested that the steel dissolution is an endothermic, spontaneous process. In addition, the experimental findings match well with the Langmuir adsorption isotherm and physisorption of the extract prevails. Furthermore, SEM/EDX and UV-Vis analyses demonstrated that the steel surface is protected by the extract molecules, confirming the electrochemical results. Density functional theory (DFT), Fukui function and molecular dynamics (MD) calculations unraveled the nature of inhibitor-metal surface interactions and provided insights into the most favorable electrophilic and nucleophilic active sites of oleic acid, a major constituent of the extract, helping to elucidate the mechanism of corrosion inhibition at the molecular level.M. Boudalia acknowledges the support from Mohammed V University and H.M.A. Amin acknowledges the support from Cairo University.Eddahhaoui, F.; Najem, A.; Elhawary, M.; Boudalia, M.; Campos, OS.; Tabyaoui, M.; Garcia-Anton, J.... (2024). Experimental and computational aspects of green corrosion inhibition for low carbon steel in HCl environment using extract of Chamaerops humilis fruit waste. Journal of Alloys and Compounds. 977. https://doi.org/10.1016/j.jallcom.2023.17330797