Perceptions of workers on the benefits of institutional source sorting: A case of the Council for Scientific and Industrial Research - Institute of Industrial Research (CSIR-IIR), Accra, Ghana

The management of solid wastes at the workplace in Ghana is characterised by mixed wastes pickup delays, dustbin overflows and leakage of plastic bags into the environment. Benefits from the pilot of source sorting as a mitigation measure at the workplace are unavailable in literature. Hence, the study employed descriptive statistical tools to assess the advantages of a piloted source sorting system at the CSIR-IIR. The sampled size was 100 staff with an 80% questionnaire recovery rate. The analysis of data showed that, the implementation of segregation at source transformed the social approach of workers towards waste management. Most workers (97.7%) preferred sorting their wastes at source irrespective of the location of the generation point. A congenial environment was created by the source separation infra­structure, which made staff worked better, (70% responses). The majority of staff (95.2%) confirmed the savings made by the Institute on the cost of landfilling. The sorting at source improved cleanliness of the compound (97.6% responses) and eliminated open-air burning of wastes (95.1% responses). In all, the source segregation was beneficial to the social, economic and environmental well-being of staff and management of the Institution

Ab initio investigation of O₂ adsorption on Ca-doped LaMnO₃ cathodes in solid oxide fuel cells

We present a Hubbard-corrected density functional theory (DFT+U) study of the adsorption and reduction reactions of oxygen on the pure and 25% Ca-doped LaMnO3 (LCM25) {100} and {110} surfaces. The effect of oxygen vacancies on the adsorption characteristics and energetics has also been investigated. Our results show that the O2 adsorption/reduction process occurs through the formation of superoxide and peroxide intermediates, with the Mn sites found to be generally more active than the La sites. The LCM25{110} surface is found to be more efficient for O2 reduction than the LCM25{100} surface due to its stronger adsorption of O2, with the superoxide and peroxide intermediates shown to be energetically more favorable at the Mn sites than at the Ca sites. Moreover, oxygen vacancy defect sites on both the {100} and {110} surfaces are shown to be more efficient for O2 reduction, as reflected in the higher adsorption energies calculated on the defective surfaces compared to the perfect surfaces. We show from Löwdin population analysis that the O2 adsorption on the pure and 25% Ca-doped LaMnO3 surfaces is characterized by charge transfer from the interacting surface species into the adsorbed oxygen πg orbital, which results in weakening of the O-O bonds and its subsequent reduction. The elongated O-O bonds were confirmed via vibrational frequency analysis

Ab initio investigation of O2 adsorption on Ca-doped LaMnO3 cathodes in solid oxide fuel cells

We present a Hubbard-corrected density functional theory (DFT+U) study of the adsorption and reduction reactions of oxygen on the pure and 25% Ca-doped LaMnO3 (LCM25) {100} and {110} surfaces. The effect of oxygen vacancies on the adsorption characteristics and energetics has also been investigated. Our results show that the O2 adsorption/reduction process occurs through the formation of superoxide and peroxide intermediates, with the Mn sites found to be generally more active than the La sites. The LCM25{110} surface is found to be more efficient for O2 reduction than the LCM25{100} surface due to its stronger adsorption of O2, with the superoxide and peroxide intermediates shown to be energetically more favorable at the Mn sites than at the Ca sites. Moreover, oxygen vacancy defect sites on both the {100} and {110} surfaces are shown to be more efficient for O2 reduction, as reflected in the higher adsorption energies calculated on the defective surfaces compared to the perfect surfaces. We show from Löwdin population analysis that the O2 adsorption on the pure and 25% Ca-doped LaMnO3 surfaces is characterized by charge transfer from the interacting surface species into the adsorbed oxygen πg orbital, which results in weakening of the O–O bonds and its subsequent reduction. The elongated O–O bonds were confirmed via vibrational frequency analysis

Synergistic Effects of Mutations and Nanoparticle Templating in the Self-Assembly of Cowpea Chlorotic Mottle Virus Capsids

A study of the in vitro nanoparticle-templated assembly of a mutant of cowpea chlorotic mottle virus lacking most of the N-terminal domain (residues 4−37), NΔ34, is presented. Mutant empty proteins assemble into empty capsids with a much broader distribution of sizes than the wild-type virus. This increased flexibility in the assembly outcomes is known to be detrimental for the assembly process in the presence of molecular polyanions. However, when rigid polyanionic cores are used, such as nanoparticles, the assembly process is restored and virus-like particles form. Moreover, the breadth of the nanoparticle-templated capsid size distribution becomes comparable with the wild-type virus size distribution

May Measurement Month 2019: an analysis of blood pressure screening results from Ghana-Sub-Saharan Africa

Raised blood pressure (BP) remains the biggest single risk factor contributing to the global burden of disease and to global mortality. Although a substantial number of people who have hypertension are either oblivious of it, not treated, or being managed but remain uncontrolled. May Measurement Month (MMM) is a global initiative led by the International Society of Hypertension (ISH) with the goal of increasing awareness of high BP and serving as a spur to establish screening programmes worldwide. An opportunistic cross-sectional survey of volunteers aged ≥18 years was carried out in May 2019. Measurement of BP and collection of relevant health information were performed according to a standardized protocol for MMM. Screening sites were set up in churches, mosques, health facilities, pharmacies, recreational parks, sports facilities, shopping centres, marketplaces, universities, workplaces, and community centres across four regions of Ghana. A total of 7102 participants gave their consent and were screened during MMM 2019. After multiple imputation, of all 7102 participants 1836 (25.9%) had hypertension. Of all 1836 participants with hypertension, 36.5% were aware of their status and 30.0% were on anti-hypertensive medication. Of 550 participants on antihypertensive medications, 46.1% had controlled BP (systolic BP <140 mmHg and diastolic BP <90 mmHg). Also, of all 1836 participants with hypertension, 13.8% had their BP controlled. Again, the proportion of participants with hypertension of those not receiving anti-hypertensive treatment was 1286 (19.6%). Data obtained from this project demonstrates that there is still a significant number of people with hypertension who are unaware of having it, are untreated, or are on treatment but remain uncontrolled. It also highlights the significance of BP screening campaigns as a tool to identify persons with elevated BP

Role of Surface Charge Density in Nanoparticle-Templated Assembly of Bromovirus Protein Cages

Self-assembling icosahedral protein cages have potencially useful physical and chemical characteristics for a variety of nanotechnology applications, ranging from therapeutic or diagnostic vectors to building blocks for hierarchical materials. For application-specific functional control of protein cage assemblies, a deeper understanding of the interaction between the protein cage and its payload is necessary. Protein-cage encapsulated nanoparticles, with their well-defined surface chemistry, allow for systematic control over key parameters of encapsulation such as the surface charge, hydrophobicity, and size. Independent control over these variables allows experimental testing of different assembly mechanism models. Previous studies done with Brome mosaic virus capsids and negatively charged gold nanoparticles indicated that the result of the self-assembly process depends on the diameter of the particle. However, in these experiments, the surface-ligand density was maintained at saturation levels, while the total charge and the radius of curvature remained coupled variables, making the interpretation of the observed dependence on the core size difficult. The current work furnishes evidence of a critical surface charge density for assembly through an analysis aimed at decoupling the surface charge and the core size