Thermogalvanic effects on the corrosion of copper in heavy brine LiBr solutions

Thermogalvanic corrosion of copper in heavy brine LiBr solutions has been investigated using a zero-resistance ammeter (ZRA). The temperature gradients between copper electrodes immersed in the same LiBr solution result in the formation of thermogalvanic cells with hot anodes, leading to high and sustained thermogalvanic currents. Copper loss rates, calculated using Faraday's law, substantially exceed 0.025 mm year−1, a value regarded as the threshold of low corrosion rates. The effects of thermogalvanic coupling on the surface properties of the anode and the cathode have been analysed by means of electrochemical impedance spectroscopy (EIS). The results obtained in this analysis have been related to the process of copper electrodissolution in bromide media

Inhibitive effect of sodium (E)-4-(4-nitrobenzylidenamino) benzoate on the corrosion of some metals in sodium chloride solution

The inhibition performance of a novel anionic carboxylic Schiff base, sodium (E)-4-(4-nitrobenzylideneamino)benzoate (SNBB), was investigated for various metals, namely low carbon steel F111, pure iron and copper, in neutral 10 mM NaCl solution. Potentiodynamic polarization, scanning vibrating electrode technique (SVET), quantum chemical (QC) calculation, and molecular dynamics (MD) simulation were employed. The potentiodynamic polarization data showed that SNBB acts as an effective corrosion inhibitor for both iron and F111 steel, but it is not effective for the copper. In situ spatially-resolved SVET maps evidenced a major change in surface reactivity for Fe and F111 steel immersed in 10 mM aqueous solution in the absence and in the presence of SNBB. Featureless ionic current density distributions were recorded in the presence of SNBB at both their spontaneous open circuit potential (OCP) and under mild anodic polarization conditions, while major ionic flows were monitored above the metals in the absence of SNBB. On the basis of computer simulations, it is proposed that SNBB produces a stable chelate film on iron and steel surfaces that accounts for the good corrosion inhibition efficiency observed. The different inhibition efficiencies of SNBB molecules on the iron and copper was attributed to the special chemical structure of SNBB molecule and its different chelation ability with the released metal ions on the metal surface. The QC calculations also confirmed the high corrosion inhibition efficiency of SNBB. The MD simulation indicated higher binding energy of SNBB on iron surface compared to that of copper surface. The interaction mode of SNBB on iron and F111 steel surfaces corresponds to a mixed chemical and physical adsorption, and it obeys the Langmuir isother

Measuring the availability of human resources for health and its relationship to universal health coverage for 204 countries and territories from 1990 to 2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: Human resources for health (HRH) include a range of occupations that aim to promote or improve human health. The UN Sustainable Development Goals (SDGs) and the WHO Health Workforce 2030 strategy have drawn attention to the importance of HRH for achieving policy priorities such as universal health coverage (UHC). Although previous research has found substantial global disparities in HRH, the absence of comparable cross-national estimates of existing workforces has hindered efforts to quantify workforce requirements to meet health system goals. We aimed to use comparable and standardised data sources to estimate HRH densities globally, and to examine the relationship between a subset of HRH cadres and UHC effective coverage performance. Methods: Through the International Labour Organization and Global Health Data Exchange databases, we identified 1404 country-years of data from labour force surveys and 69 country-years of census data, with detailed microdata on health-related employment. From the WHO National Health Workforce Accounts, we identified 2950 country-years of data. We mapped data from all occupational coding systems to the International Standard Classification of Occupations 1988 (ISCO-88), allowing for standardised estimation of densities for 16 categories of health workers across the full time series. Using data from 1990 to 2019 for 196 of 204 countries and territories, covering seven Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) super-regions and 21 regions, we applied spatiotemporal Gaussian process regression (ST-GPR) to model HRH densities from 1990 to 2019 for all countries and territories. We used stochastic frontier meta-regression to model the relationship between the UHC effective coverage index and densities for the four categories of health workers enumerated in SDG indicator 3.c.1 pertaining to HRH: physicians, nurses and midwives, dentistry personnel, and pharmaceutical personnel. We identified minimum workforce density thresholds required to meet a specified target of 80 out of 100 on the UHC effective coverage index, and quantified national shortages with respect to those minimum thresholds. Findings: We estimated that, in 2019, the world had 104·0 million (95% uncertainty interval 83·5–128·0) health workers, including 12·8 million (9·7–16·6) physicians, 29·8 million (23·3–37·7) nurses and midwives, 4·6 million (3·6–6·0) dentistry personnel, and 5·2 million (4·0–6·7) pharmaceutical personnel. We calculated a global physician density of 16·7 (12·6–21·6) per 10 000 population, and a nurse and midwife density of 38·6 (30·1–48·8) per 10 000 population. We found the GBD super-regions of sub-Saharan Africa, south Asia, and north Africa and the Middle East had the lowest HRH densities. To reach 80 out of 100 on the UHC effective coverage index, we estimated that, per 10 000 population, at least 20·7 physicians, 70·6 nurses and midwives, 8·2 dentistry personnel, and 9·4 pharmaceutical personnel would be needed. In total, the 2019 national health workforces fell short of these minimum thresholds by 6·4 million physicians, 30·6 million nurses and midwives, 3·3 million dentistry personnel, and 2·9 million pharmaceutical personnel. Interpretation: Considerable expansion of the world's health workforce is needed to achieve high levels of UHC effective coverage. The largest shortages are in low-income settings, highlighting the need for increased financing and coordination to train, employ, and retain human resources in the health sector. Actual HRH shortages might be larger than estimated because minimum thresholds for each cadre of health workers are benchmarked on health systems that most efficiently translate human resources into UHC attainment

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

The Determinants of Libyan Red Meat Import Demand Equation For the Period (1970-2010)

In 2010, Libya's red meat supply stood at about 77 thousand tonnes, about 25 percent was imported. Given the insufficient levels of domestic red meat production, the government mainly relies on imported red meat to fill the gap. The objective of this study is to examine factors affecting import demand for red meat in Libya, also investigates whether there is exists a long run relationship between red meat import quantity and its major determinants by using annual data for the period 1962-2010. Based on abounds test known as Auto-Regressive Distributed Lag model (ARDL). The results of the bounds test reveal that the quantity of red meat imports and its determinants namely red meat import price, Gross Domestic Product and domestic meat production are cointegrated. The results also indicate that the demand for red meat imports is elastic with respect to import price level in the short run. However, in the long run, the price elasticity becomes greater while the income elasticity level remains less than one. Thus, this indicates that red meat imports are generally considered as necessary good

Dynamic Econometric Modeling and Policy Analysis of the Libyan Wheat Market

Wheat plays a major role in food contribution, it is considered as a principal food grain in the daily life of the people in Libya. In addition, wheat is an important commodity to the Libyan economy in terms of its contribution to the country’s GDP, food requirement and farm income. The production of wheat in Libya, however, has been declining over the years. Consequently, it is vital to identify the economic and policy variables that influence its decline in the production in order to formulate appropriate policy measures. This study addresses the issue of government intervention on the Libyan wheat industry. The main objective of this study is to investigate the characteristics of the Libyan wheat market and analyse the impact of changes in government policies on wheat production, area, yield, consumption and imports. The Libyan wheat market model was estimated using the auto regressive distributed lag model (ARDL). The study used a time series data from 1970 to 2000. The model consists of area, yield, production, consumption and wheat imports equations. Annual models for the Libyan wheat market are developed based on market factors as well as government agricultural commodity programmes. The results from the wheat area equation indicate that the influence of relative price is significant in affecting acreage, and price-acreage relationship is positive. This means that if the price is enhanced, the production of wheat may improve considerably. The coefficient of agricultural loan is positive and statistically significant. This indicates that agricultural loan is also an important determinant for wheat area equation. The results from the wheat yield equation show that the real fertiliser price coefficient is negative and statistically significant. The implication of this finding in terms of policy formulation is that attention has to be paid to promote the wheat producers with low fertiliser prices to reach the desired level of yield. Technology is also found to be an important non-price factor affecting wheat yield. Income and prices are still important variables in determining the level of wheat consumption. Finally, the findings indicate that import demand for wheat is largely explained by per capita GDP. Simulations are also used to estimate the impacts of the three agricultural policies on wheat area, production, import, and consumption. The conclusions are drawn from a simulation experiment and from an analysis of policy. The results suggest that the model is an acceptable approximation of the Libyan wheat market

The Relationship between Export and Economic Growth in Libya Arab Jamahiriya

This study investigates the relationships between export and economic growth in Libya. An econometric model has been developed and estimated in order to determine the direction of causality in both, short and long run. The annual time series used for the estimation cover the time period 1980 – 2007. The findings indicate that the income, exports and relative prices are cointegrated. The long run bidirectional causality between the exports and income growth has been also proved. The study result indicates that the export promotion policy contributes to the economic growth in Libya

The Relationship between Export and Economic Growth in Libya Arab Jamahiriya

This study investigates the relationships between export and economic growth in Libya. An econometric model has been developed and estimated in order to determine the direction of causality in both, short and long run. The annual time series used for the estimation cover the time period 1980 – 2007. The findings indicate that the income, exports and relative prices are cointegrated. The long run bidirectional causality between the exports and income growth has been also proved. The study result indicates that the export promotion policy contributes to the economic growth in Libya.export; economic growth; Libya; cointegration; Granger causality; export led growth.