Waste Management at Construction Sites in the Municipality of Manaus, Amazonas, Brazil: Characterization of the Current Situation

This research aimed the characterization of the current production of construction waste in the city of Manaus, Amazonas, Brazil, and its impacts on the environment of the Amazon Region. The significance of this research work is to contribute to the improvement of the environmental management of waste in the construction sites of the city of Manaus, with the aim of preserving the Amazonian environment. This research also sought to characterize the existing problems in the environmental management of construction waste in four construction sites, with areas greater than 9,000 square meters. The methodology adopted was based on the application of an in situ survey in four construction sites in the city of Manaus, Amazonas, Brazil, administered by three companies representing the construction sector in the Amazon Region. Data were collected at the construction sites in question in the second half of 2018, regarding the types of construction waste produced, respective volumes, destination and associated costs. A comparison was made between constructed areas and volumes of waste produced, characterizing the current situation of construction waste production in the city of Manaus. After analysing the results obtained, it was concluded that due to the high associated costs, companies avoid recycling construction waste, and opt to discharge it in municipal or clandestine landfills, with significant environmental impacts. For this reason, a greater participation of the Public Administration is recommended regarding the adequate management of waste in construction sites, namely offering financial incentives for companies to promote the recycling and reuse of construction waste.info:eu-repo/semantics/publishedVersio

Análise teórico e experimental de ligações tipo RHS/CHS com afastamento

This work presents a study of welded K joints with gap, formed by a structural steel hot rolled hollow section, having rectangular hollow sections at the chords and circular hollow sections in the others members. The study developed theoretical and numerical analyses for the joints, experimental tests in full scale prototypes. Theoretical analyses were performed using code standards for K joints. The results in terms of behavior, ultimate load and collapse mode were analyzed and compared with numerical (finite elements) and theoretical models. The theoretical analysis was carried out from the code regulations. The joints tested indicated the failure mode of Plastic failure of the chord face (mode A). The results showed that the loads using code regulations and the ones from the numerical analysis had good agreement for the K joint.Nesse trabalho, é apresentado um estudo de ligações soldadas tipo K com afastamento, constituídas de barras tubulares de aço sem costura, sendo usada seção transversal tubular retangular, no banzo, e circular, para os outros elementos. O estudo envolveu análise teórica e numérica, para as ligações, além de ensaios de protótipos, em escala real. As análises teóricas utilizaram normas de projeto, para a ligação K. Os ensaios foram realizados, em protótipos, em escala real, visando à obtenção do comportamento, da carga última e do modo de falha da ligação e à calibração com modelo numérico (elementos finitos), bem como visando a se fazer uma comparação com prescrições normativas. Essas ligações ensaiadas apresentaram, como modo de falha, a plastificação da face do banzo (modo A). Os resultados numéricos indicaram que a relação entre as cargas numéricas e as de projeto, obtidas pelas prescrições, apresenta boa correlação, para ligações K.29530

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