Analysis of a Hybrid Solar Collector Photovoltaic Thermal (PVT)

AbstractA solar hybrid photovoltaic thermal (PVT) is a set of combined solar collector, which consists of a photovoltaic module (PV) for the conversion of electrical energy and solar plan for the high efficiency thermal energy conversion, in the same frame.An attempt made to analyze the hybrid solar collector using Computational Fluid Dynamics (CFD) to simulate the PVT solar collector to a better understanding of heat transfer capabilities in this type of systems. In the present work, the fluid flow and heat transfer in the module are studied using the ANSYS14 software. The heat transfer phenomenon conjugate between the photovoltaic cells and the coolant is modeled using the FLUENT software. The transfer of heat by the solar radiation is not modeled; however, the effects of radiation are taken for consideration when calculating the conditions for heat flux limit for the collector region. The geometric model and fluid domain for the CFD analysis is generated using ANSYS software DesingModeler, mesh geometry is carried out by ANSYS Meshing Software

Resurgence of Ebola virus in 2021 in Guinea suggests a new paradigm for outbreaks

These authors contributed equally: Alpha K. Keita, Fara R. Koundouno, Martin Faye, Ariane Düx, Julia Hinzmann.International audienc

Hispanic health in the USA: a scoping review of the literature

Hispanics are the largest minority group in the USA. They contribute to the economy, cultural diversity, and health of the nation. Assessing their health status and health needs is key to inform health policy formulation and program implementation. To this end, we conducted a scoping review of the literature and national statistics on Hispanic health in the USA using a modified social-ecological framework that includes social determinants of health, health disparities, risk factors, and health services, as they shape the leading causes of morbidity and mortality. These social, environmental, and biological forces have modified the epidemiologic profile of Hispanics in the USA, with cancer being the leading cause of mortality, followed by cardiovascular diseases and unintentional injuries. Implementation of the Affordable Care Act has resulted in improved access to health services for Hispanics, but challenges remain due to limited cultural sensitivity, health literacy, and a shortage of Hispanic health care providers. Acculturation barriers and underinsured or uninsured status remain as major obstacles to health care access. Advantageous health outcomes from the “Hispanic Mortality Paradox” and the “Latina Birth Outcomes Paradox” persist, but health gains may be offset in the future by increasing rates of obesity and diabetes. Recommendations focus on the adoption of the Health in All Policies framework, expanding access to health care, developing cultural sensitivity in the health care workforce, and generating and disseminating research findings on Hispanic health

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

Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

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

Formation and Transport of a Saharan Dust Plume in Early Summer

This research studies the capability of the Weather Research and Forecasting model coupled with the Chemistry/Aerosol module (WRF-Chem) with and without parametrization to reproduce a dust storm, which was held on 27th June 2018 over Sahara region. The authors use satellite observations and ground-based measurements to evaluate the WRF-Chem simulations. The sensitivities of WRF-Chem Model are tested on the replication of haboob features with a tuned GOCART aerosol module. Comparisons of simulations with satellite and ground-based observations show that WRF-Chem is able to reproduce the Aerosol Optical Depth (AOD) distribution and associated changes of haboob in the meteorological fields with temperature drops of about 9 °C and wind gust 20 m·s–1. The WRF-Chem Convection-permitting model (CPM) shows strong 10-meter winds induced a large dust emission along the leading edge of a convective cold pool (LECCP). The CPM indicates heavy dust transported over the West African coast (16°W-10°W; 6°N-21°N) which has a potential for long-distance travel on 27th June between 1100 UTC and 1500 UTC. The daily precipitation is improved in the CPM with a spatial distribution similar to the GPM-IMERG precipitation and maximum rainfall located at the right place. As well as raising a large amount of dust, the haboob caused considerable damage along its route

Analysis of contact tracing data showed contribution of asymptomatic and non-severe infections to the maintenance of SARS-CoV-2 transmission in Senegal

Abstract During the COVID-19 pandemic in Senegal, contact tracing was done to identify transmission clusters, their analysis allowed to understand their dynamics and evolution. In this study, we used information from the surveillance data and phone interviews to construct, represent and analyze COVID-19 transmission clusters from March 2, 2020, to May 31, 2021. In total, 114,040 samples were tested and 2153 transmission clusters identified. A maximum of 7 generations of secondary infections were noted. Clusters had an average of 29.58 members and 7.63 infected among them; their average duration was 27.95 days. Most of the clusters (77.3%) are concentrated in Dakar, capital city of Senegal. The 29 cases identified as super-spreaders, i.e., the indexes that had the most positive contacts, showed few symptoms or were asymptomatic. Deepest transmission clusters are those with the highest percentage of asymptomatic members. The correlation between proportion of asymptomatic and degree of transmission clusters showed that asymptomatic strongly contributed to the continuity of transmission within clusters. During this pandemic, all the efforts towards epidemiological investigations, active case-contact detection, allowed to identify in a short delay growing clusters and help response teams to mitigate the spread of the disease