359 results on '"Structure Collapse"'
Search Results
2. The efficient geometrical nonlinear analysis method for civil engineering structures
- Author
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Al-Nadhari, Abdulrahman M., Abderrahmani, Sifeddine, Hamadi, Djamal, and Legouirah, Maria
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- 2024
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3. Feasibility of neck electrical impedance tomography to monitor upper airway dynamics during sleep
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Vivien S. Piccin, Erick D. L. B. de Camargo, Rafaela G. S. Andrade, Vinícius Torsani, Fabíola Schorr, Priscilla S. Sardinha, Fernanda Madeiro, Pedro R. Genta, Marcelo G. Gregório, Carlos R. R. de Carvalho, Marcelo B. P. Amato, and Geraldo Lorenzi-Filho
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diagnostic imaging ,electric impedance ,obstructive sleep apnea ,structure collapse ,electrical impedance tomography ,nasofibroscopy ,Medicine - Abstract
BackgroundThere is a lack of non-invasive methods for monitoring the upper airway patency during sleep. Electrical impedance tomography (EIT) is a non-invasive, radiation-free tool that has been validated to monitor lung ventilation. We hypothesized that electrical impedance tomography (EIT) can be used for monitoring upper airway patency during sleep.MethodsSleep was induced in 21 subjects (14 males, age 43 ± 13 years, body mass index 32.0 ± 5.3 kg/m2) with suspected obstructive sleep apnea (apnea-hypopnea index: 44 ± 37 events/h, range: 1–122 events/h) using low doses of midazolam. Patients wore a nasal mask attached to a modified CPAP device, allowing variable and controlled degrees of upper airway obstruction. Confirmation of upper airway patency was obtained with direct visualization of the upper airway using nasofibroscopy (n = 6). The changes in total neck impedance and in impedance in four cranio-caudal regions of interest (ROIs) were analyzed.ResultsTotal neck impedance varied in concert with breathing cycles and peaked during expiration in all patients. Group data showed a high cross-correlation between flow and impedance curves (r = −0.817, p < 0.001). Inspiratory peak flow correlated with simultaneous neck impedance (r = 0.866, p < 0.001). There was a high correlation between total neck impedance and velopharynx area (r = 0.884, p < 0.001), and total neck impedance and oropharynx area (r = 0.891, p < 0.001).ConclusionsNeck EIT is sensitive and captures pharyngeal obstruction under various conditions. Neck EIT is a promising method for real-time monitoring of the pharynx during sleep.
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- 2023
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4. Infrared Small Target Detection via Dynamic Image Structure Evolution.
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Xia, Chaoqun, Chen, Shuhan, Zhang, Xiaoqin, Chen, Zhaomin, and Pan, Zhiyong
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ITERATIVE learning control , *CLUTTER (Noise) , *BINARY codes , *SIGNAL-to-noise ratio - Abstract
Infrared small target detection (IRSTD) is a challenging task, due to the scarce target feature, complex background interferences, and poor image quality. The existing studies handle the IRSTD problem by making specific distribution assumptions of target and background, which incurs two issues. First, the specific assumptions of background cannot always hold. Second, the distorted target distributions contaminated by heavy clutters and noise are difficult to model statically. This article handles the problems from the discriminative and dynamic perspectives and proposes an original mechanism named dynamic image structure evolution (DISE) and a DISE-derived single-frame IRSTD framework. First, we resolve IRSTD by a discriminative model without assuming specific background distributions, which is based on a mathematical definition of structure singularity modeling the ideal target structure. Second, to decouple the target distributions from interferences, DISE guides the distorted target to reveal potential structure singularity, while suppressing the interference signal through iterative procedures of structure collapse, intensity settlement, and collapse convergence. The three functional procedures of DISE perform their own duties regarding target enhancement and background suppression. Moreover, an innovative chain mechanism is introduced to propagate the structure field. Experiments on real datasets demonstrate the superiority of DISE against the state-of-the-art IRSTD methods. [ABSTRACT FROM AUTHOR]
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- 2022
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5. Alleviating Structure Collapse of Polycrystalline LiNi x Co y Mn 1- x - y O 2 via Surface Co Enrichment.
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Shang M, Ren H, Zhao W, Li Z, Fang J, Chen H, Fan W, Pan F, and Zhao Q
- Abstract
The structure collapse issues have long restricted the application of polycrystalline LiNi
x Coy Mn1- x - y O2 (NCM) at high voltages beyond 4.4 V vs Li/Li+ . Herein, for LiNi0.55 Co0.12 Mn0.33 O2 (P-NCM), rapid surface degradation is observed upon the first charge, along with serious particle fragmentation upon repeated cycles. To alleviate these issues, a surface Co enrichment strategy is proposed [i.e., Co-enriched NCM (C-NCM)], which promotes the in situ formation of a robust surface rock-salt (RS) layer upon charge, serving as a highly stable interface for effective Li+ migration. Benefiting from this stabilized surface RS layer, Li+ extraction occurs mainly through this surface RS layer, rather than along the grain boundaries (GBs), thus reducing the risk of GBs' cracking and even particle fragmentation upon cycles. Besides, O loss and TM (TM = Ni, Co, and Mn) dissolution are also effectively reduced with fewer side reactions. The C-NCM/graphite cell presents a highly reversible capacity of 205.1 mA h g-1 at 0.2 C and a high capacity retention of 86% after 500 cycles at 1 C (1 C = 200 mA g-1 ), which is among the best reported cell performances. This work provides a different path for alleviating particle fragmentation of NCM cathodes.- Published
- 2024
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6. Sediment source fingerprints of natural processes and anthropogenic pressures: A contribution to manage the Paraopeba River basin impacted by the B1 tailings dam collapse.
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Acuna-Alonso C, do Valle Junior RF, de Melo Silva MMAP, Pissarra TCT, de Melo MC, Valera CA, Sanches Fernandes LF, Pacheco FAL, and Álvarez X
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- Conservation of Natural Resources, Anthropogenic Effects, Geologic Sediments, Environmental Policy, Brazil, Environmental Monitoring methods, Structure Collapse
- Abstract
Understanding the origins of sediment transport in river systems is crucial for effective watershed management, especially after catastrophic events. This information is essential for the development of integrated strategies that guarantee water security in river basins. The present study aimed to investigate the rupture of the B1 tailings dam of the Córrego do Feijão mine, which drastically affected the Brumadinho region (Minas Gerais, Brazil). To address this issue, a confluence-based sediment fingerprinting approach was developed through the SedSAT model. Uncertainty was assessed through Monte Carlo simulations and Mean Absolute Error (MAE). Estimates of the overall average contributions of each tributary were quantified for each station and annually during the period 2019-2021. It was observed that the sampling point PT-09, closest to the dam breach, contributed to almost 80% of the Paraopeba River in 2019. Despite the dredging efforts, this percentage increased to 90% in 2020 due to the need to restore the highly degraded area. Additionally, the main tributaries contributing to sediment increase in the river are Manso River "TT-03" (almost 36%), associated with an area with a high percentage of urban land use, and Cedro stream "TT-07" (almost 71%), whose geology promotes erosion, leading to higher sediment concentration. Uncertainties arise from the limited number of available tracers, variations caused by dredging activities, and reduced data in 2020 due to the pandemic. Parameters such as land use, riparian vegetation degradation, downstream basin geology, and increased precipitation are key factors for successfully assessing tributary contributions to the Paraopeba River. The obtained results are promising for a preliminary analysis, allowing the quantification of key areas due to higher erosion and studying how this disaster affected the watershed. This information is crucial for improving decision-making, environmental governance, and the development of mitigating measures to ensure water security. This study is pioneering in evaluating this methodology in watersheds affected by environmental disasters, where restoration efforts are ongoing., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
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- 2024
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7. Multi-index comprehensive evaluation model for assessing risk to trainees in an emergency rescue training base for building collapse.
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Li J, Huang Z, Wang H, Ding H, Jia Q, Zhao W, Le T, Jameel D, and Wang P
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- Accidents, Risk Factors, Surveys and Questionnaires, Structure Collapse
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Rescues from building collapse accidents present a significant challenge for China's emergency rescue system. However, there are also many risk factors in a training scenario, which have been summarized in this study. A hierarchical indicator system for personnel safety was established, including 12 first-level indicators and 23s-level indicators. Then, an improved Grey-DEMATEL-ISM-MICMAC evaluation model was constructed to evaluate the level of risk. Influencing factor scores were determined according to the responses from the questionnaire survey. The influencing degree, influenced degree, centrality, and causality were identified, and the importance, relevance, and clustering of the various factors were obtained after making quantitative calculations. The results showed that the order of priority for solving the essential issues was safety education (A
2 ), operating standards and proficiency (A10 ), equipment inspection (A4 ), equipment warehousing maintenance and records (A21 ). The solving of safety education was identified to be the most essential priority. The priority control order of direct causes was Scientific design and construction (A5 ), Potential fixed hazards in the facility (A12 ), Physical fitness of personnel (A1 ), Weather influences (A18 ), and Initiation efficiency of emergency plans (A20 ), and direct control measures for these five factors could achieve a relatively significant effect., (© 2024. The Author(s).)- Published
- 2024
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8. 基于敏感性分析的结构抗倒塌能力提升方法研究.
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朱南海 and 贺小玲
- Abstract
Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
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9. Significance of Lateral Pillar in Osteonecrosis of Femoral Head: A Finite Element Analysis
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Peng-Fei Wen, Wan-Shou Guo, Qi-Dong Zhang, Fu-Qiang Gao, Ju-An Yue, Zhao-Hui Liu, Li-Ming Cheng, and Zi-Rong Li
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Displacement ,Finite Element Analysis ,Osteonecrosis of the Femoral Head ,Stress ,Structure Collapse ,Medicine - Abstract
Background: The lateral pillar of the femoral head is an important site for disease development such as osteonecrosis of the femoral head. The femoral head consists of medial, central, and lateral pillars. This study aimed to determine the biomechanical effects of early osteonecrosis in pillars of the femoral head via a finite element (FE) analysis. Methods: A three-dimensional FE model of the intact hip joint was constructed from the image data of a healthy control. Further, a set of six early osteonecrosis models was developed based on the three-pillar classification. The von Mises stress and surface displacements were calculated for all models. Results: The peak values of von Mises stress in the cortical and cancellous bones of normal model were 6.41 MPa and 0.49 MPa, respectively. In models with necrotic lesions in the cortical and cancellous bones, the von Mises stress and displacement of lateral pillar showed significant variability: the stress of cortical bone decreased from 6.41 MPa to 1.51 MPa (76.0% reduction), while cancellous bone showed an increase from 0.49 MPa to 1.28 MPa (159.0% increase); surface displacements of cortical and cancellous bones increased from 52.4 μm and 52.1 μm to 67.9 μm (29.5%) and 61.9 μm (18.8%), respectively. In addition, osteonecrosis affected not only pillars but also adjacent structures in terms of the von Mises stress and surface displacement levels. Conclusions: This study suggested that the early-stage necrosis in the femoral head could increase the risk of collapse, especially in lateral pillar. On the other hand, the cortical part of lateral pillar was found to be the main biomechanical support of femoral head.
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- 2017
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10. Are fish assemblages recovering after the huge disaster of mining tailing dam collapse in Mariana (Brazil-MG)?
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Petesse ML, Pomaro SB, and de Castro Campanha PMG
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- Humans, Animals, Brazil, Environmental Monitoring, Structure Collapse, Disasters, Catfishes
- Abstract
The Doce River basin is located in the Brazilian states of Minas Gerais (MG) and Espírito Santo (ES). Anthropogenic expansion throughout the twentieth century heavily modified the bioecological configuration of the region, which was worsened in November 2015 by the collapse of the Fundão tailing dam in Mariana municipality (MG). Local ichthyofauna suffered a loss of environmental quality, which served as an alert to the possible decline of native species and transformation of fish assemblages. Through a systematic literature review, the present study aimed to investigate the recovery stage of fish assemblage after the disaster. To accomplish this, we selected 14 documents reporting species lists and fish distributions in the area principally affected by the disaster. Data collected about fish assemblage (presence/absence) were spatially (upper, middle, and lower sections) and temporally (pre- and post-disaster) arranged, followed by non-metric multidimensional scaling (NMDS) analysis to assess similarity. We applied the Analysis of Similarities (ANOSIM) non-parametric test to confirm statistically significant differences between groups. We complemented the study by searching for the main bioecological characteristics of the most frequent species raised among the selected documents. NMDS showed differences in the similarity of fish assemblages among the three spatial sections, as confirmed by ANOSIM (p < 0.05), but no differences for the temporal component were observed. Nevertheless, we detected a trend based on continental fish assemblage transformation, as determined by the presence of many non-native species in the post-disaster period, suggesting the better resilience of these species over that of native species. The missing of many native species previously easily collected, mainly from the families Characidae, Loricariidae, and Trichomycteridae, suggested the system moving toward a new condition, probably worsened than the previous one. The ichthyofauna of the estuarine environment, on the contrary, seems to have recovered faster than ichthyofauna from the continental environment., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)
- Published
- 2023
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11. Anchoring K+ in Li+ Sites of LiNi0.8Co0.15Al0.05O2 Cathode Material to Suppress its Structural Degradation During High‐Voltage Cycling.
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Zhao, Junkai, Wang, Zhixing, Wang, Jiexi, Guo, Huajun, Li, Xinhai, Gui, Weihua, Chen, Ning, and Yan, Guochun
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CATHODES ,ELECTRIC potential ,ELECTRIC impedance - Abstract
The rapid rise of electrode impedance and capacity decay of Ni‐rich layered cathode materials during high‐voltage cycling are rooted in their severe structural degradation. Here we present a feasible strategy, anchoring ∼1 % K+ into the Li+ sites of LiNi0.8Co0.15Al0.05O2 as an excellent structural stabilizer, to overcome aforementioned issues, and the similarities and differences in terms of modification mechanism is compared with Na+. Showing difference with Na+ that tends to migrate into electrolyte during high‐voltage cycling, K+ occupies in Li+ site firmly because of its larger ionic radius and lower migrating ability, which sustainably prevent the irreversible phase transition between two hexagonal phases (H2 and H3) and impede the cation migration in highly delithiated state, thus suppressing the structural degradation. Benefiting from these merits, Li0.99K0.01Ni0.8Co0.15Al0.05O2 delivers a large initial discharge capacity of 217 mAh g−1 at 0.1 C and maintains stable cycling at 1 C in a high voltage of 4.6 V (remaining 87.4 % of its initial capacity after 150 cycles). The mechanism proposed in this work, accounting for enhanced structural stability under high‐voltage cycling by K+ anchoring in Ni‐rich cathode materials, provides a vital hint for rational designing advanced cathode materials to pursue high energy density Li‐ion batteries. K+ anchoring in Li+ sites of LiNi0.8Co0.15Al0.05O2 prevent the collapse of host structure and inhibit cation migration in highly delithiated state. Benefit from these, Li0.99K0.01Ni0.8Co0.15Al0.05O2 exhibits superior high‐voltage electrochemical performances. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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12. Prevalência de sintomas psiquiátricos e seus fatores associados na população adulta da área atingida pelo rompimento da barragem de rejeitos: Projeto Saúde Brumadinho
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Garcia,Frederico Duarte, Neves,Maila de Castro Lourenço das, Firmo,Josélia Oliveira Araújo, Peixoto,Sérgio Viana, and Castro-Costa,Erico
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Structure collapse ,Colapso estrutural ,Associated factors ,Desastres tecnológicos ,Psychiatric symptoms ,Technological disasters ,Prevalence ,Prevalência ,Fatores associados ,Sintomas psiquiátricos - Abstract
Objective: To examine the prevalence of psychiatric symptoms and associated factors in the adult population of Brumadinho (MG), after the dam collapse. Methods: We included 2,740 participants with information about symptoms of post-traumatic stress disorder (PTSD), depression, anxiety, thoughts of death/self-harm, and poor sleep quality collected in 2021. Prevalence values of all conditions were estimated to compare the prevalence of psychiatric symptoms with the participants’ sociodemographic characteristics and place of residence. Pearson’s c2 test was used, with Rao Scott’s correction. Crude and adjusted logistic regressions estimated odds ratios and 95% confidence intervals to assess the association between psychiatric symptoms and participants’ characteristics. Results: The most common condition was depressive symptoms (29.3%), followed by post-traumatic stress symptoms (22.9%) and anxious symptoms (18.9%). Regarding the association between participants’ characteristics in the adjusted analysis, being a female and living in a mining area was positively associated with symptoms of PTSD, depression, anxiety, thoughts of death/self-harm, and poor sleep quality. A positive association was also found between high school education and post-traumatic stress symptoms. In contrast a negative association was found between being aged ≥60 years and symptoms of PTSD, depression, and anxiety. Conclusion: High prevalence values were found for all psychiatric symptoms after the dam failure in Brumadinho. Being a female, living in the mining area, being ≥60 years old, and having an educational level were all associated with the psychiatric symptoms investigated. RESUMO: Objetivo: Examinar a prevalência dos sintomas psiquiátricos e seus fatores associados na população adulta de Brumadinho (MG), após o rompimento da barragem. Métodos: Foram incluídos 2.740 participantes com informações coletadas em 2021 sobre os sintomas de estresse pós-traumático (TEPT), depressão, ansiedade, ideias de morte/automutilação e pior qualidade do sono. Estimaram-se as prevalências de todas as condições. Para a comparação das prevalências dos sintomas psiquiátricos e as características sociodemográficas e local de moradia, empregou-se o teste χ2 de Pearson, com correção de Rao-Scott. Regressões logísticas brutas e ajustadas estimaram os odds ratios e intervalos de confiança de 95%, permitindo a avaliação da associação entre os sintomas psiquiátricos e as características dos participantes. Resultados: Os sintomas depressivos foram a condição mais prevalente (29,3%), seguidos pelos sintomas de TEPT (22,9%) e sintomas ansiosos (18,9%). Com relação à investigação da associação entre as características dos participantes na análise ajustada, observou-se que o sexo feminino e os moradores da área de mineração apresentaram relação positiva com os sintomas de TEPT, depressivos, ansiosos, ideia de morte e pior qualidade de sono. Também se encontraram associação positiva entre a escolaridade de nível médio e os sintomas de TEPT e associação negativa entre aqueles com ≥60 anos e os sintomas de TEPT, depressivos e ansiosos. Conclusão: Altas prevalências foram encontradas para todos os sintomas psiquiátricos após a ruptura da barragem em Brumadinho. Sexo feminino, local de moradia na área de mineração, ≥60 anos e escolaridade foram associados aos sintomas psiquiátricos investigados.
- Published
- 2022
13. Residual Guest-Assisted MOF-5 Powder Densification
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Bin Zheng, Li Zhang, Wanting Yao, Lianli Wang, Dong Tian, Ke Gao, and Jinlei Wang
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Inorganic Chemistry ,Structure Collapse ,Chemical engineering ,Chemistry ,Specific surface area ,Physical and Theoretical Chemistry ,Residual ,Positive function - Abstract
Powder densification for specified shaped metal-organic frameworks (MOFs) is desirable for most applications. The obtainment of such properties is challenging, one of which is the rapid crystal-to-amorphous transition (framework collapse) of MOFs under pressure. Herein, we found that the residual guests of the MOF-5 synthesis process could form binding groups based on the hydrogen-bonding networks of water. The improved processability and ease of compression, which did not promote rapid structure collapse, can be achieved in the guest-loaded MOF-5. Correspondingly, enhanced volumetric specific surface area and methane uptake of MOF-5 were obtained. This work focuses on a commonly neglected but positive function of the residual guests in MOFs, besides supporting the framework. MOFs loaded with multiple types of guests show attractive mechanical properties via guest-guest and guest-host interactions for powder densification, highlighting their commercial applications.
- Published
- 2021
14. Brumadinho Health Project: food and nutrition insecurity versus socioeconomic statuses and dimensions of the food system after the dam rupture
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Mariana Souza Lopes, Patrícia Pinheiro de Freitas, Mary Anne Nascimento-Souza, Sérgio Viana Peixoto, and Aline Cristine Souza Lopes
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Structure collapse ,Epidemiology ,Public Health, Environmental and Occupational Health ,Nutritional Status ,General Medicine ,Food security ,Segurança alimentar e nutricional ,Socioeconomic factors ,Desastres provocados pelo homem ,Saúde ,Man-made disasters ,Food Supply ,Cross-Sectional Studies ,Fatores socioeconômicos ,Social Class ,Socioeconomic Factors ,Health ,Colapso estrutural ,Humans ,Brazil - Abstract
Objective: To describe the situation of food insecurity of families according to the socioeconomic characteristics and dimensions of the food system in Brumadinho, state of Minas Gerais, Brazil, after the dam rupture in Córrego do Feijão mine. Methods: This is a descriptive study focused on households carried out from the baseline of the Brumadinho Health Project. Food insecurity, the main outcome, was assessed by the short version of the Brazilian Food Insecurity Scale. Other investigated variables were: socioeconomic data; geographic stratum of the households; family's assets; income; expenses; cultivation of food and animal husbandry for consumption. Descriptive analyses were performed comparing the food insecurity of the household according to the other variables by the χ2 test to compare the proportions. Results: Of the investigated households (n=1,441), 35.1% were facing food insecurity. facing food insecurity had: lower prevalence of masonry households with coating (91.4%; 95%CI 87.7%−94.1% vs. 96.7%; 95%CI 94.9%−97.8%); highest proportion of rudimentary cesspit (16.9%; 95%CI 13.3%−21.2% vs. 9.4%; 95%CI 7.4−11.9); lower prevalence of own and paid-off homes (63.9%; 95%CI 56.8−70.5 vs. 77.3%; 95%CI 72.3−81.7); and income reduction after the dam rupture (33.0%; 95%CI 27.1−39.6 vs. 14.1%; 95%CI 11.2−17.6), when compared with those in a food security situation. Conclusion: The prevalence of food insecurity was high, with report of a reduction in household income after the dam rupture. Moreover, most of the households had worse structural quality and sewage outfall. These results evidence the vulnerability of families and possible violation of the human right to adequate food, denoting the urgency of continuous reparative actions. RESUMO Objetivo: Descrever a situação de insegurança alimentar das famílias segundo as características socioeconômicas e dimensões do sistema alimentar em Brumadinho, Minas Gerais, Brasil, após desastre. Métodos: Estudo descritivo com foco no domicílio realizado pela linha de base do Projeto Saúde Brumadinho. A insegurança alimentar, desfecho principal, foi avaliada pela Escala Brasileira de Insegurança Alimentar curta. Outras variáveis investigadas foram: socioeconômicas; estrato geográfico do domicílio; ativos (bens); renda; despesas familiares; cultivo de alimentos e criação de animais para consumo. Foram realizadas análises descritivas comparando a insegurança alimentar do domicílio segundo as demais variáveis pelo teste χ2 para comparação das proporções. Resultados: Dos domicílios investigados (n=1.441), 35,1% estavam em situação de insegurança alimentar. As famílias em insegurança alimentar apresentavam: menores prevalências de domicílios de alvenaria com revestimento (91,4%; IC95% 87,7%−94,1% vs. 96,7%; IC95% 94,9%−97,8%); maior proporção de fossa rudimentar (16,9%; IC95% 13,3%−21,2% vs. 9,4%; IC95% 7,4−11,9); menor prevalência de domicílios próprios e quitados (63,9%; IC95% 56,8−70,5 vs. 77,3%; IC95% 72,3−81,7); e redução da renda após o rompimento da barragem (33,0%; IC95% 27,1−39,6 vs. 14,1%; IC95% 11,2−17,6), quando comparadas àquelas em segurança alimentar. Conclusão: A prevalência de insegurança alimentar foi elevada, com relato de redução da renda das famílias após o rompimento da barragem. Ademais, boa parte dos domicílios apresentava pior qualidade estrutural e escoamento de esgoto. Esses resultados evidenciam a vulnerabilidade das famílias e possível violação do direito humano à alimentação adequada, denotando a urgência de ações reparadoras contínuas.
- Published
- 2022
15. Structural Health Monitoring of Fatigue Cracks for Steel Bridges with Wireless Large-Area Strain Sensors
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Sdiq Anwar Taher, Jian Li, Jong-Hyun Jeong, Simon Laflamme, Hongki Jo, Caroline Bennett, William N. Collins, and Austin R. J. Downey
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Steel ,Remote Sensing Technology ,Humans ,structural health monitoring ,fatigue crack ,soft elastomeric capacitor ,wireless sensors ,large-area strain sensor ,civil infrastructure ,steel bridges ,generalized Morse wavelet ,peak detection ,traffic loads ,Electrical and Electronic Engineering ,Biochemistry ,Instrumentation ,Atomic and Molecular Physics, and Optics ,Structure Collapse ,Analytical Chemistry - Abstract
This paper presents a field implementation of the structural health monitoring (SHM) of fatigue cracks for steel bridge structures. Steel bridges experience fatigue cracks under repetitive traffic loading, which pose great threats to their structural integrity and can lead to catastrophic failures. Currently, accurate and reliable fatigue crack monitoring for the safety assessment of bridges is still a difficult task. On the other hand, wireless smart sensors have achieved great success in global SHM by enabling long-term modal identifications of civil structures. However, long-term field monitoring of localized damage such as fatigue cracks has been limited due to the lack of effective sensors and the associated algorithms specifically designed for fatigue crack monitoring. To fill this gap, this paper proposes a wireless large-area strain sensor (WLASS) to measure large-area strain fatigue cracks and develops an effective algorithm to process the measured large-area strain data into actionable information. The proposed WLASS consists of a soft elastomeric capacitor (SEC) used to measure large-area structural surface strain, a capacitive sensor board to convert the signal from SEC to a measurable change in voltage, and a commercial wireless smart sensor platform for triggered-based wireless data acquisition, remote data retrieval, and cloud storage. Meanwhile, the developed algorithm for fatigue crack monitoring processes the data obtained from the WLASS under traffic loading through three automated steps, including (1) traffic event detection, (2) time-frequency analysis using a generalized Morse wavelet (GM-CWT) and peak identification, and (3) a modified crack growth index (CGI) that tracks potential fatigue crack growth. The developed WLASS and the algorithm present a complete system for long-term fatigue crack monitoring in the field. The effectiveness of the proposed time-frequency analysis algorithm based on GM-CWT to reliably extract the impulsive traffic events is validated using a numerical investigation. Subsequently, the developed WLASS and algorithm are validated through a field deployment on a steel highway bridge in Kansas City, KS, USA.
- Published
- 2022
16. Preparation and characterization of glass hollow fiber membrane for water purification applications.
- Author
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Makhtar, Siti, Rahman, Mukhlis, Ismail, Ahmad, Othman, Mohd, and Jaafar, Juhana
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HOLLOW fibers ,ARTIFICIAL membranes ,ZEOLITES ,WATER purification ,MICROSTRUCTURE - Abstract
This work discusses the preparation and characterizations of glass hollow fiber membranes prepared using zeolite-5A as a starting material. Zeolite was formed into a hollow fiber configuration using the phase inversion technique. It was later sintered at high temperatures to burn off organic materials and change the zeolite into glass membrane. A preliminary study, that used thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier transform infrared (FTIR), confirmed that zeolite used in this study changed to glass at temperatures above 1000 °C. The glass hollow fiber membranes prepared using the phase inversion technique has three different microstructures, namely (i) sandwich-like structure that originates from inner layer, (ii) sandwich-like that originates from outer layer, and (iii) symmetric sponge like. These variations were influenced by zeolite weight loading and the flow rate of water used to form the lumen. The separation performances of the glass hollow fiber membrane were studied using the pure water permeability and the rejection test of bovine serum albumin (BSA). The glass hollow fiber membrane prepared from using 48 wt% zeolite loading and bore fluid with 9 mL min flow rate has the highest BSA rejection of 85% with the water permeability of 0.7 L m h bar. The results showed that the separation performance of glass hollow fiber membranes was in the ultrafiltration range, enabled the retention of solutes with molecular sizes larger than 67 kDa such as milk proteins, endotoxin pyrogen, virus, and colloidal silica. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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17. After Ukrainian dam breach, war hampers study of ecological toll.
- Author
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Stokstad E
- Subjects
- Ukraine, Biodiversity, Animals, Rivers, Armed Conflicts, Disasters, Floods, Structure Collapse
- Abstract
Mines and active combat make fieldwork too risky.
- Published
- 2023
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18. Ukraine dam collapse: what scientists are watching.
- Author
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Naddaf M
- Subjects
- Humans, Agriculture, Environment, Public Health, Research Personnel, Ukraine, Russia, Floods, Structure Collapse, Armed Conflicts
- Published
- 2023
- Full Text
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19. Assessment of Health Risk and Presence of Metals in Water and Fish Samples from Doce River, Brazil, After Fundão Dam Collapse.
- Author
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Mourão AO, Santos MS, da Costa ASV, da Silva HT, Maia LFO, Faria MCDS, Rodriguez MDVR, and Rodrigues JL
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- Animals, Humans, Rivers, Brazil, Water analysis, Environmental Monitoring, Metals analysis, Fishes, Structure Collapse, Water Pollutants, Chemical analysis, Mercury analysis
- Abstract
The rupture of the Fundão dam released about 50 million m
3 of mining tailings in the Doce river basin. To assess the potential for environmental contamination and the risks of residual exposure of the human population generated by these tailings, water and fish samples from the Doce river were collected 25 days after the accident and analyzed the physicochemical parameters of the water and levels of metals by ICP-MS, in addition to the temporal variability of the concentration of these elements through other studies. This was the first study to carry out an assessment of the health risk associated with the consumption of fish contaminated by metals from the areas affected by the disaster. The values of turbidity (5460 NTU), electrical conductivity (74.8 μS cm-1 ), total dissolved solids (892 mg L-1 ) and total suspended solids (772 mg L-1 ) were above the maximum limit allowed by Brazilian legislation, due to the presence of large amounts of solid materials released after the dam rupture. The analysis of metals in water samples indicated high concentrations of Al (1,906.71 μg L-1 ), Mn (370.32 μg L-1 ), Fe (8,503.50 μg L-1 ) and Hg (34.25 μg L-1 ), while for the fish samples, only As (1,033.98 μg kg-1 ) and Hg (herbivorous: 505.32 μg kg-1 ; predatory: 1,184.09 μg kg-1 ) presented levels above those established by Brazilian legislation. The health risk assessment showed that the estimated daily intake for Hg was higher than the reference dose, reinforcing the need for monitoring the area affected by the disaster., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)- Published
- 2023
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20. Avoidable environmental disasters and infant health: Evidence from a mining dam collapse in Brazil
- Author
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Lucas Emanuel, Daniel Lopes, Breno Sampaio, Daniel Da Mata, and Bladimir Carrillo
- Subjects
Health Policy ,media_common.quotation_subject ,Birth weight ,Environmental disaster ,Infant health ,Tailings ,Infant mortality ,Dam Collapse ,Disasters ,Geography ,Environmental health ,Humans ,Tragedy (event) ,Infant Health ,Welfare ,Brazil ,Structure Collapse ,Environmental Monitoring ,media_common - Abstract
We study the health consequences of one of the largest environmental disasters of the world mining industry, which largely stemmed from regulatory failure. Exploiting the timing and location of the Mariana mine tailings dam collapse in Brazil, we show that in utero exposure to the tragedy significantly reduced birth weight and increased infant mortality. The adverse effects were stronger for infants born to less educated and nonmarried mothers. These findings indicate that poorly enforced environmental regulation may have long-term welfare impacts on local communities.
- Published
- 2020
21. Ecotoxicological Assessment of the Doce River Surface Water After the Fundão Dam Collapse
- Author
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Rodolfo Pessotti Messner Campelo, Ross Edward William Smith, Laila Carine Campos Medeiros, Tatiana Heid Furley, Fernando Aquinoga de Mello, Lucas Bueno Mendes, and Kátia Regina Chagas
- Subjects
010504 meteorology & atmospheric sciences ,Geography, Planning and Development ,Fresh Water ,010501 environmental sciences ,01 natural sciences ,Dam Collapse ,Water column ,Rivers ,Animals ,Chronic toxicity ,Structure Collapse ,0105 earth and related environmental sciences ,General Environmental Science ,Hydrology ,Suspended solids ,biology ,Water ,Ceriodaphnia dubia ,General Medicine ,biology.organism_classification ,Tailings ,Acute toxicity ,Environmental science ,Surface water ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
On 5 November 2015, the Samarco Fe ore mining operations released approximately 50 million cubic meters of mining waste into the environment, due to a dam collapse. Aiming at understanding the potential effects on the Doce River, different regions of the course of tailings were monitored using acute and chronic ecotoxicological tests with 4 species: Ceriodaphnia dubia, Daphnia similis, Danio rerio, and Vibrio fischeri. The results showed no acute toxicity for water column organisms. However, chronic toxicity was observed with the tests with the microcrustacean C. dubia, mainly related to the physical effects of the passage of flood wave and increased suspended solids, given that toxicity was reduced after filtering the samples. The results showed different magnitudes of impact among the upper, middle, and lower Doce River, with greater impact close to the dam failure area. Integr Environ Assess Manag 2020;16:608-614. © 2020 SETAC.Em 5 de novembro de 2015, aproximadamente 50 milhões de m
- Published
- 2020
22. Impacts of the Samarco Tailing Dam Collapse on Metals and Arsenic Concentration in Freshwater Fish Muscle from Doce River, Southeastern Brazil
- Author
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Carlos Frankl Sperber, Mariella Bontempo Freitas, Frederico Fernandes Ferreira, Natállia Vicente, Neucir Szinwelski, Jorge Abdala Dergam, Laila Carine Campos Medeiros, and Carlos Ernesto Gonçalves Reynaud Schaefer
- Subjects
010504 meteorology & atmospheric sciences ,Floodplain ,Geography, Planning and Development ,Drainage basin ,chemistry.chemical_element ,Fresh Water ,010501 environmental sciences ,01 natural sciences ,Arsenic ,Rivers ,Geophagus ,Metals, Heavy ,Animals ,Humans ,Structure Collapse ,0105 earth and related environmental sciences ,General Environmental Science ,Biodilution ,geography ,geography.geographical_feature_category ,Tailings dam ,biology ,Muscles ,Fishes ,General Medicine ,biology.organism_classification ,Tailings ,Mercury (element) ,chemistry ,Environmental chemistry ,Bioaccumulation ,Freshwater fish ,Environmental science ,Brazil ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
On November 2015, Samarco tailings dam in Mariana, Minas Gerais, Brazil, collapsed, releasing 62 million tons of tailings that advanced through 668 km of the Doce River and adjacent floodplain. Although the collapse was the worst environmental disaster in Brazil, little is known about its consequences to aquatic biota. Here we evaluate the effects of the tailings mudflow on metal and As concentration in fish and how concentration correlates with water and fish characteristics. We quantified semitotal amounts of Ag, Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn in fish muscle tissue using inductively coupled plasma mass spectrometry (ICP-MS) in 255 individuals (34 species) sampled in unaffected and affected areas along the Doce River basin. Arsenic and Hg were higher in fish from affected sites, likely due to turbulent mixing of previously sedimented material by the giant tailings wave. Silver and Zn concentrations were higher in unaffected sites. Arsenic concentration in Geophagus brasiliensis decreased with increasing fish weight. Copper and Zn decreased with increasing fish weight considering the whole assembly of fish. The tailings mudflow increased water conductivity, and conductivity increased Al concentration in fish, so we expected a larger Al concentration in fishes from affected sites. However, the observed Al concentration in fishes from affected sites was lower than expected by water conductivity. Thus, the tailings mudflow reduced Al uptake or accumulation in fishes. Mercury decreased with increasing water conductivity in both unaffected and affected sites considering all species and in G. brasiliensis alone. Despite the relatively low concentration range of metals and As found in fish, fishes from sites affected by the Fe ore tailings mudflow showed higher As and Hg concentration, compared to fishes from unaffected sites. The higher As and Hg in affected sites require further detailed monitoring to ensure safeguards of human health by fishing activity along the Doce River. Integr Environ Assess Manag 2020;16:622-630. © 2020 SETAC.Em novembro de 2015, a barragem de rejeitos da Samarco em Mariana, MG, Brasil, rompeu, liberando 62 milhões de toneladas de rejeitos de minério de ferro que avançaram por 668 km do rio Doce e planície adjacente. Embora este tenha sido considerado o pior desastre ambiental do país, pouco se sabe sobre as consequências da liberação do fluxo de lama para a biota aquática. Aqui avaliamos os efeitos do fluxo de lama de rejeitos sobre a bioacumulação de metais e arsênio em várias espécies de peixes coletadas na bacia do rio Doce e como a bioacumulação se correlaciona com as características da água e dos peixes. Quantificamos as quantidades semitotais de Ag, Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb e Zn no tecido muscular de peixes usando ICP-MS em um total de 255 indivíduos (representando 34 espécies), amostrados em locais não afetados e afetados ao longo da bacia do rio Doce. As concentrações de As e Hg foram maiores nos peixes dos locais afetados, provavelmente devido à mistura turbulenta de material previamente sedimentado pela onda gigante de rejeitos. As concentrações de Ag e Zn foram maiores nos peixes de locais não afetados. A concentração de As na espécie mais abundante nos locais não afetados e afetados (Geophagus brasiliensis) diminuiu com o aumento do peso dos peixes. A concentração de Cu e Zn diminuiu com o aumento do peso dos peixes, considerando toda a assembleia de espécies. O fluxo de lama de rejeitos aumentou a condutividade da água e a condutividade aumentou a concentração de Al nos peixes, portanto esperávamos uma maior concentração de Al nos peixes de locais afetados. No entanto, a concentração de Al observada nos peixes de locais afetados foi menor do que o esperado pela condutividade da água. Assim, o fluxo de lama de rejeitos reduziu a assimilação ou o acúmulo de Al nos peixes. O mercúrio diminuiu com o aumento da condutividade da água nos locais não afetados e afetados, considerando todas as espécies e também dentro de G. brasiliensis. Apesar da faixa de concentração relativamente baixa de metais nos peixes, os peixes de locais afetados pelo fluxo de lama de rejeitos de minério de ferro apresentaram maior concentração de As e Hg, em comparação com peixes de locais não afetados. A maior concentração de As e Hg nos locais afetados requer um monitoramento mais detalhado para garantir segurança alimentar em relação à atividade pesqueira ao longo do rio Doce. Integr Environ Assess Manag 2020;16:622-630.
- Published
- 2020
23. Civil Society and Social Mobilizations in the Context of the Rio Doce Socioenvironmental Disaster
- Author
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Euzeneia Carlos
- Subjects
Civil society ,010504 meteorology & atmospheric sciences ,Corporate governance ,media_common.quotation_subject ,Geography, Planning and Development ,Context (language use) ,General Medicine ,010501 environmental sciences ,Public administration ,Collective action ,01 natural sciences ,Disasters ,Politics ,Rivers ,Social Conditions ,Argument ,Political science ,Humans ,Imitation ,Brazil ,Structure Collapse ,0105 earth and related environmental sciences ,General Environmental Science ,Social movement ,media_common - Abstract
To explain how social movements and organizations changed in the context of the Rio Doce, Brazil socioenvironmental disaster, this article identifies a process of organizational innovation. The research is based on documental data and interviews with activists over the 3 y of the disaster. The main argument is that organizational innovation consists of changes in organizational forms and repertoires of collective action, based on existing organizational models and tactics. On the one hand, the innovation occurred through the territorialization of novel organizational forms, intermediated by social movements that act as incubators. On the other hand, it consisted of the combination among extrainstitutional, institutional, and multiscalar repertoires and in the innovation in tactics and performances. Mechanisms of adaptation, imitation, and negotiated diffusion are identified which operated in this innovation process. It is argued that the organizational innovation of social movements was propelled by political constraints of disaster governance, which pushed them to innovation, in addition to the role of preexisting organizations. Integr Environ Assess Manag 2020;16:681-690. © 2020 SETAC.Para explicar como os movimentos sociais e organizações da sociedade civil mudaram no contexto do desastre socioambiental do Rio Doce, este artigo identificou um processo de inovação organizacional. A pesquisa é baseada em dados documentais e entrevistas com ativistas ao longo dos três anos do desastre. O argumento principal é que a inovação organizacional consiste em mudanças nas formas organizacionais e repertórios da ação coletiva, com base nos modelos organizacionais e táticas disponíveis. Por um lado, a inovação ocorreu através da territorialização de novas formas organizacionais, intermediadas por movimentos sociais que atuaram como incubadoras. Por outro, consistiu na combinação entre repertórios extrainstitucionais, institucionais e multiescalares e na inovação nas táticas e performances. São identificados os mecanismos de adaptação, imitação e difusão negociada que operaram nesse processo de inovação. Argumenta-se que a inovação organizacional dos movimentos sociais foi impulsionada por constrangimentos políticos da governança do desastre que os levaram à inovação, além do papel das organizações pré-existentes. Integr Environ Assess Manag 2020;16:681-690.
- Published
- 2020
24. Molecular Dynamics Simulations of Twisting-Induced Helical Carbon Nanotube Fibers for Reinforced Nanocomposites
- Author
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Chao Wang, Miao Linlin, Jiaxuan Li, Xiaodong He, Xu Zhonghai, Yushun Zhao, and Chao Sui
- Subjects
Atomic simulation ,Structure Collapse ,Molecular dynamics ,Work (thermodynamics) ,Toughness ,Nanocomposite ,Materials science ,law ,Ultimate tensile strength ,General Materials Science ,Carbon nanotube ,Composite material ,law.invention - Abstract
Carbon nanotube fibers have attracted much interest because of their outstanding multifunctional properties. In this work, double-helix carbon nanotube fibers (DHCNFs) assembled by combined self-twisting and whole-twisting processes are presented, and their mechanical properties were studied based on atomic simulation. We found that the self-twisting of carbon nanotubes (CNTs) can lead to interesting intertube entanglements, with the formation of a helical structure. In addition, the twisting process can cause a remarkable decline of the mechanical properties of CNTs owing to their hollow structure collapse, thus deteriorating the tensile mechanical performances of DHCNFs. Meanwhile, by tuning related twisting parameters, different fracture failure modes, including simultaneous and stepwise breakages, can be found. More importantly, it was revealed that, as nanoenhancements, the helical morphology of DHCNFs can effectively enhance the interlocking effect between CNTs and the matrix, thereby improving the interfacial strength and toughness of DHCNF-reinforced nanocomposites. This work systemically studied the effect of the twisting operation on the mechanical properties of DHCNFs and provided an innovative way of simultaneously enhancing the strength and toughness of CNT-based nanocomposites.
- Published
- 2020
25. Methods for Postdisaster Impact Assessment: A Case Study of the Impacts of the Fundão Dam Failure on Terrestrial Species Threatened with Extinction
- Author
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Thiago Alves, Leandro Arruda, Brock Simons, Kyle H. Knopff, and Lucio Cadaval Bede
- Subjects
Extinction ,Watershed ,Tailings dam ,010504 meteorology & atmospheric sciences ,Impact assessment ,business.industry ,Geography, Planning and Development ,Environmental resource management ,General Medicine ,010501 environmental sciences ,01 natural sciences ,Biodiversity hotspot ,Disasters ,Dam failure ,Rivers ,Threatened species ,Animals ,Environmental science ,Terrestrial ecosystem ,business ,Brazil ,Ecosystem ,Structure Collapse ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
The Fundão tailings dam held back approximately 50 million cubic meters of tailings from an Fe ore mine in the state of Minas Gerais, Brazil. The dam failed on 5 November 2015, releasing tailings into the Rio Doce watershed and causing an environmental disaster in a biodiversity hotspot. To guide conservation action following the event, Brazilian authorities demanded an impact assessment focused on terrestrial species threatened by extinction. Postdisaster impact assessment is substantially more challenging than predevelopment impact assessment. Predisaster baseline data were sparse, and much was unknown about how the Fundão dam failure impacted terrestrial species threatened with extinction. Baseline reconstruction and impact pathway validation and characterization was critical. Ecosystem reconstruction revealed that 1580 ha of terrestrial ecosystems were destroyed, including approximately 480 ha of Atlantic rainforest. Collaboration with local experts identified 346 species of vertebrates, invertebrates, and vascular plants threatened with extinction that were impacted or potentially impacted. Species composition and impacts varied within 4 distinct segments of the Rio Doce watershed. Nine potential impact pathways were identified using data and literature review combined with information provided by regulators, experts, and media. Not all were valid. Validating and characterizing each pathway within each watershed segment involved data evaluation, an ecological risk screening, and field assessments. Impact pathway evaluation proved critical to dispelling misconception, accurately understanding postdisaster impacts, and directing conservation action; the importance of this step cannot be overemphasized. Integr Environ Assess Manag 2020;16:676-680. © 2020 SETAC.A barragem de Fundão armazenava milhões de metros cúbicos de rejeitos de uma mina de ferro no estado de Minas Gerais, Brasil. A barragem se rompeu em 5 de novembro de 2015, liberando rejeitos para a bacia do rio Doce, provocando um desastre ambiental em um hotspot de biodiversidade. Visando orientar ações de conservação após o evento, autoridades ambientais brasileiras demandaram uma avaliação de impactos com foco em espécies ameaçadas de extinção. Avaliações de impacto pós-desastre são substancialmente mais desafiadoras do que avaliações padrão, que antecedem a execução de empreendimentos. No caso de Fundão, dados da linha de base anterior ao desastre eram escassos, e pouco se sabia a respeito de como os vetores de impacto relacionados ao rompimento poderiam ter afetado a biodiversidade terrestre, incluindo a sua magnitude, duração e abrangência espacial. Consequentemente, a reconstrução da linha de base e a validação e caracterização dos potenciais vetores de impacto foram os primeiros passos essenciais. A reconstrução da linha de base para ecossistemas, feita a partir de imagens de satélite, revelou que aproximadamente 1580 ha de ecossistemas terrestres foram suprimidos, incluindo ~480 ha de mata atlântica. Por meio de colaboração com especialistas na biodiversidade local e utilizando fontes diversas de dados e literatura, foram identificadas 346 espécies de vertebrados, invertebrados e plantas vasculares ameaçadas de extinção ocorrentes ou potencialmente ocorrentes nas áreas afetadas. A composição em espécies variou entre quatro distintos segmentos da bacia do rio Doce, assim como os impactos incidentes. Nove potenciais vetores de impacto foram identificados utilizando-se dados e revisões da literatura, além de informações fornecidas por órgãos ambientais e especialistas, e pela mídia. A validação e caracterização de cada vetor de impacto em cada segmento da bacia envolveu a avaliação de dados, uma análise preliminar de risco ecológico, e avaliações em campo. A avaliação de vetores de impacto mostrou-se fundamental para dirimir equívocos de interpretação e acuradamente entender os impactos pós-desastre; a importância desta etapa não pode ser menosprezada. O cruzamento de características biológicas e ecológicas das espécies terrestres ameaçadas de extinção, em cada segmento da bacia, com a caracterização dos vetores de impacto, permitiu a atribuição de consequências dos impactos, constituindo uma maneira efetiva de priorizar medidas mitigadoras com vistas ao alcance de metas de conservação pós-desastre. Integr Environ Assess Manag 2020;16:676-680.
- Published
- 2020
26. Experimental, numerical and field study investigating a heritage structure collapse after the 2015 Gorkha earthquake
- Author
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Sean Wilkinson, David G. Toll, C.E. Davis, Paul Hughes, Ashutosh Kumar, Sarhosis, RB Kunwar, A Joshi, Prem Nath Maskey, Robin Coningham, K Weise, and K.P. Acharya
- Subjects
Geotechnical investigation ,021110 strategic, defence & security studies ,Atmospheric Science ,Hydrogeology ,business.industry ,Settlement (structural) ,0211 other engineering and technologies ,Foundation (engineering) ,02 engineering and technology ,Plinth ,Masonry ,010502 geochemistry & geophysics ,01 natural sciences ,Structure Collapse ,Natural hazard ,Earth and Planetary Sciences (miscellaneous) ,Geotechnical engineering ,business ,Geology ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
This paper presents an investigation of the collapse of a 325-year-old multi-tiered heritage temple during the 2015 Gorkha earthquake in Kathmandu, Nepal. The research comprises a reconnaissance survey followed by a geotechnical investigation and numerical back-analysis carried out to understand the potential causes of the collapse. The assessment of the structural configuration of the temple indicated seismic vulnerability in the design due to the presence of discontinuous columns over the height of the temple and age-weakened bonding in the masonry walls. The geotechnical investigation revealed the presence of competent soil strata at the location, assisting the survey which indicated no differential or excessive settlement in the foundation. A series of cyclic triaxial tests were conducted on samples recovered during the geotechnical investigation to determine dynamic behaviour of the soil. Further, dynamic analysis of the plinth of the temple under the recorded acceleration–time history indicated a maximum drift percentage of 1.4% and residual relative displacement of 32 mm suggesting the potential reason behind the collapse. The output of this research will support seismic rehabilitation of ancient structures within World Heritage sites across Nepal and effective action plans to safeguard them against future earthquake hazard.
- Published
- 2020
27. Cultivating vegetables in tailings from the Fundão dam collapse: metal accumulation and risks to food safety
- Author
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Humberto Araújo Almeida, Felipe Della Torre, and Queila Souza Garcia
- Subjects
Food Safety ,General Medicine ,Management, Monitoring, Policy and Law ,Plants ,Pollution ,Soil ,Metals ,Metals, Heavy ,Vegetables ,Humans ,Soil Pollutants ,Brazil ,Structure Collapse ,General Environmental Science ,Environmental Monitoring - Abstract
A great amount of iron ore tailings from the collapse of the Fundão dam in Southeast Brazil was deposited in an extensive agricultural area. The presence of this material creates insecurity for the resumption of agricultural activities, especially the cultivation of vegetables, which can accumulate metals at potentially toxic levels. In this study, two vegetables consumed in the affected area, arugula and radish, were cultivated in tailings and in soil. Productivity, photosynthetic pigment content, photosynthetic performance, metal accumulation, and the possible risk to food safety were analyzed. The productivity of both vegetables, arugula and radish, did not differ between cultivation in tailings and in soil. There were no differences in pigment content nor substantial differences in the photosynthetic parameters of plants grown in the two substrates. Plants grown in tailings had higher Fe, Mn, and Na contents than those grown in soil, reflecting the higher levels of these elements in the former. There were no visual signs of metal toxicity for plants grown in the tailings. The levels of metals potentially ingested through estimated consumption of arugula and radish grown in the tailings were below the maximum allowable limits for human consumption. In addition, calculated risk indices suggest a low potential for harm to the health of consumers of cultivated vegetables in the tailings. The results presented here suggest that agricultural cultivation in the tailings is viable and contribute to the resumption of vegetable cultivation in the region affected by the tailings released with the collapse of the Fundão dam.
- Published
- 2021
28. Brazil’s preventable bridge disasters
- Author
-
William E, Magnusson
- Subjects
Disasters ,Multidisciplinary ,Brazil ,Structure Collapse - Published
- 2022
29. Study on optimization of inspection mechanism of concrete beam bridge
- Author
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Dan Su, Yi-Sheng Liu, Xin-Tong Li, and Zhicheng Cao
- Subjects
Atmospheric Science ,Computer science ,Data management ,Temperature Gradients ,Plan (drawing) ,Wind ,law.invention ,Beam bridge ,Mathematical and Statistical Techniques ,law ,Materials Testing ,Materials ,Structure Collapse ,Multidisciplinary ,Physics ,Applied Mathematics ,Simulation and Modeling ,Statistics ,Workload ,Built Structures ,Physical Sciences ,Medicine ,Engineering and Technology ,Thermodynamics ,Algorithms ,Research Article ,Computer and Information Sciences ,Structural Engineering ,Science ,Materials Science ,Linkage (mechanical) ,Research and Analysis Methods ,Bridge (interpersonal) ,Vibration ,Meteorology ,Artificial Intelligence ,Humans ,Statistical Methods ,Artificial Neural Networks ,Mechanical Phenomena ,Computational Neuroscience ,business.industry ,Construction Materials ,Biology and Life Sciences ,Computational Biology ,Humidity ,Bridge inspection ,Reliability engineering ,Mechanism (engineering) ,Earth Sciences ,Composite Materials ,Stress, Mechanical ,business ,Mathematics ,Forecasting ,Concrete ,Neuroscience - Abstract
China is shifting from the stage of large-scale bridge construction to the stage of equal emphasis on the construction and maintenance of bridges. The problems of low efficiency and high cost in bridge inspection are becoming more and more prominent, which threaten people’s life safety. In this paper, the deterioration state prediction model of concrete beam bridge under Boosting DT C5.0 was established as the basis, and optimization suggestions were put forward in terms of bridge inspection standards and processes, which aims to perfect the bridge inspection mechanism, realize the fine management of the bridge and prolong the service life of the bridge. Research shows that: first, the bridge inspection standard with a single index should be improved into the bridge inspection standard with multiple indexes, so as to scientifically determine the bridges that need to be inspected and optimize the allocation of maintenance resources. Second, the bridge deterioration state prediction model is used to add a screening mechanism for the bridge in the inspection plan, which can effectively reduce the workload of bridge inspection and enhance the inspection efficiency. Third, the deterioration phenomenon of coexistence between adjacent traffic assets should be fully considered and the linkage inspection mechanism of adjacent traffic assets should be established to improve the effect of bridge inspection.
- Published
- 2021
30. Brumadinho dam collapse induces changes in the microbiome and the antibiotic resistance of the Paraopeba River (Minas Gerais, Brazil).
- Author
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Thompson C, Garcia G, Masi BP, Freitas T, Paz PHC, Leal CV, Otsuki K, Tschoeke D, Salazar V, Soares M, Lopes G, Bacha L, Cosenza C, Vieira VV, Botelho ACN, de Oliveira BCV, de Rezende CE, Teixeira L, and Thompson F
- Subjects
- Humans, Rivers microbiology, RNA, Ribosomal, 16S genetics, Brazil, Bacteria genetics, Drug Resistance, Microbial, Water analysis, Ampicillin analysis, Environmental Monitoring, Structure Collapse, Water Pollutants, Chemical analysis, Microbiota
- Abstract
The rupture of the Córrego do Feijão dam in Brumadinho (January 25, 2019) caused serious damage to the Paraopeba River and compromised the quality of its waters for human consumption. However, the possible effects of the dam collapse on the river microbiome and its antibiotic resistance profiles are unknown. The present study aims to analyse the possible shifts in microbial diversity and enhancement of antibiotic resistance in the Paraopeba River. To this end, two sampling campaigns (February and May 2019) were performed to obtain water across the entire Paraopeba River (eight sampling locations: Moeda, Brumadinho, Igarapé, Juatuba, Varginha, Angueretá, Retiro Baixo and Três Marias; ~464 km). This sampling scheme enabled determining the effects of the disaster on the river microbiome. Total DNA and microbial isolation were performed with these water samples. The 16S rRNA-based microbiome analyses (n = 24; 2.05 million 16S rRNA reads) showed changes in microbial diversity immediately after the disaster with the presence of metal-indicating bacteria (Acinetobacter, Bacillus, Novosphingobium, and Sediminibacterium). Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) identification of bacterial isolates (n = 170) also disclosed possible indicators of faecal contamination across the Paraopeba (Cloacibacterium, Bacteroides, Feaecalibacterium, Bifidobacterium, Citrobacter, Enterobacter, Enterococcus and Escherichia). Antibiotic resistance increased significantly to ampicillin, ampicillin/sulbactam, amoxicillin/clavulanate, ceftriaxone, and cefalotin among isolates obtained in May after the disaster. The effects of toxic mud on microbiomes were felt at all points sampled up to Anguereta. The ore mud may have exacerbated the growth of different antibiotic-resistant, metal-resistant, and faecal-indicating bacteria in the Paraopeba River., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
31. Changes in access to water and incidence of waterborne diseases after the Vale dam collapse in Brumadinho (MG), Brazil.
- Author
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Trovão N, Neves-Silva P, Pinheiro LC, Peixoto SV, and Heller L
- Subjects
- Humans, Brazil epidemiology, Incidence, Water, Waterborne Diseases epidemiology, Structure Collapse
- Abstract
Objective: To describe, within the Human Rights to Water and Sanitation (HRWS) framework, the access to water supply services and the incidence of waterborne diseases in the communities affected by the dam disaster in Brumadinho (MG), Brazil., Methods: A quantitative and qualitative methodology was used, having as variables information on access to water supply services and waterborne diseases. The primary data were extracted from the "Brumadinho Health Project", using a sample stratum with 981 people interviewed, totaling 92.5% of the eligible population in the affected communities of Córrego do Feijão and Parque da Cachoeira. The secondary data from Brumadinho was extracted from the project "Sanitation conditions and the River Basin of the B1 River Basin of Mineradora Vale between 2017 and 2020", available in public databases between 2017 and 2020, and qualitative data was collected in 2022 through individual interviews with health professional also live in the communities., Results: With regard to access to water supply services, the results of this combined data analysis indicate that the HRWS is being neglected, especially with regard to availability, accessibility, acceptability and quality of water. The study also shows a significant increase in the incidence of waterborne diseases in the region after the disaster., Conclusion: It is necessary to use the HRWS as the basis to the implementation of public policies aiming to reduce vulnerability in access to water supply services.
- Published
- 2023
- Full Text
- View/download PDF
32. After the fall: Responding to the Champlain Towers building collapse.
- Author
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Beidel DC, Rozek DC, Bowers CA, Newins AR, and Steigerwald VL
- Subjects
- Humans, Body Remains, Anxiety Disorders diagnosis, Structure Collapse, Stress Disorders, Post-Traumatic diagnosis, Disasters
- Abstract
In June 2021, a condominium in Florida collapsed, with the loss of 98 lives. Search and rescue teams spent 2 weeks, recovering the victims. This study's objective was to assess the presence of psychological symptoms that might emerge in the following months, using the PTSD Checklist for DSM-5 (PCL-5), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder - 7 (GAD-7), Suicide Cognitions Scale-Short (SCS-S), and the Insomnia Severity Index (ISI). A monthly survey conducted for 3 months found that overall, mean scores on these measures did not indicate significant emotional distress. We then compared the scores when the group was divided into responders who recovered human remains and those who did not. Scores were significantly higher among the subgroup that recovered human remains. Fifty-three percent (53%) of this sub-group met the cut-off score for a provisional diagnosis of PTSD, depressive disorder or generalized anxiety disorder-15% met the cut-off score criteria on the PCL-5 for probable PTSD, 36.8% for probable depressive disorder on the PHQ-9, and 26.3% for probable generalized anxiety disorder on the GAD-7. The results are consistent with other investigations examining mental health after mass disasters. Specifically, not all first responders will develop emotional distress but certain recovery activities may put some responders at higher risk, with a percentage displaying psychological distress. The results emphasize the need to assess the impact of these events on the mental health of first responders and to consider strategies to prevent or mitigate the development of impairing psychopathology., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Beidel, Rozek, Bowers, Newins and Steigerwald.)
- Published
- 2023
- Full Text
- View/download PDF
33. Importance of Team Experience and Coordination in Disaster Response: Building Collapse
- Author
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Hasan Mutlu, Selim Altinarik, Osman Türk, Semih Korkut, Kenan Ahmet Turkdogan, Erdal Yilmaz, Fatih Türkmen, and Yusuf Uğurlu
- Subjects
Male ,Emergency Medical Services ,medicine.medical_treatment ,Psychological intervention ,Disaster Planning ,01 natural sciences ,Security forces ,Disasters ,03 medical and health sciences ,0302 clinical medicine ,Intervention (counseling) ,medicine ,Humans ,Duration (project management) ,Search and rescue ,Structure Collapse ,Rehabilitation ,Emergency management ,Warning system ,business.industry ,010401 analytical chemistry ,Public Health, Environmental and Occupational Health ,medicine.disease ,0104 chemical sciences ,030228 respiratory system ,Female ,Business ,Medical emergency - Abstract
Objective:The objective of this study was to determine whether coordination of prehospital emergency health services and Disaster and Emergency Management Presidency (DEMP) and being prepared for disasters, such as building collapses, allow quick evaluation and fast intervention.Methods:The information flow, hierarchy, treatment, and rehabilitation processes, and rescue organization and planning during the rescue attempt for 35 people who needed help due to this building collapse were reviewed.Results:Of the 43 people who lived in this 8-story building, 35 were inside the building during the collapse; 40% of them were assessed as injured and 60% as exitus. Almost two-thirds (64.3%) of the injured individuals who were rescued were women. The mean duration until rescue was 330 (57.0-512.0) min.Conclusions:Leading and important factors that can increase the success rate in search and rescue interventions are informing official authorities as first early warning by individuals who can clearly define the situation, early security measures by security forces arriving before the health and search-rescue teams, accurate identification of estimated numbers of injured victims, and identifying and informing appropriate hospitals which victims rescued from the debris will be transferred to there.
- Published
- 2021
34. DAMAGE PREDICTION OF THE STEEL ARCH BRIDGE MODEL BASED ON ARTIFICIAL NEURAL NETWORK METHOD
- Author
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Fadrizal Lubis, Reni Suryanita, Widya Apriani, and Yohannes Firzal
- Subjects
Environmental Engineering ,Artificial neural network ,Computer science ,business.industry ,Soil Science ,Stiffness ,Building and Construction ,Structural engineering ,Geotechnical Engineering and Engineering Geology ,Bridge (interpersonal) ,Structure Collapse ,Girder ,medicine ,medicine.symptom ,Projection (set theory) ,business ,Reduction (mathematics) ,Parametric statistics - Abstract
Failure in the advance prediction of bridge structure collapse requires an enormous cost of rehabilitation. In most cases, the projection of decreases or damage to the structure due to difficulty in the testing condition. Therefore, this study analyses the damage and identification of the critical structural components' severity on the steel girder arch bridge. Using the Artificial Neural Networks (ANNs), this research has tested a parametric steel girder arch bridge. The numerical model of the 146 supported girder has analysed by epoch 500 values of ANNSs's parameter. The stiffness of 10th element is assumed to drop 10%, 20%, 30%, and 40% of whole the tested. The architecture model of ANNs was three neurons in the input layer, five neurons in the hidden layer and one neuron in the output layer. The simulation of the data set were 90:10, 80:20, 70:30, and 50:50. ANNs shows the damage' severity in this the stiffness reduction tested by applying the damage index methods. In this research, the ANNs' simulation has been reliable to predict 98% for identifying structural damage. Thus, the results confirm the feasibility of the technique and its application in predicting structural failure.
- Published
- 2021
35. Coral growth bands recorded trace elements associated with the Fundão dam collapse
- Author
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Carla Cristine Porcher, Alex Cardoso Bastos, Fabian Sá, Ludmilla N. Falsarella, Thiago Gonçalves Carelli, Aline Celuppi Wegner, Stewart Fallon, Leonardo T. Salgado, Pamela M. Chiroque-Solano, Paulo S. Salomon, Gabriel O. Cardoso, Felipe Padilha Leitzke, and Rodrigo L. Moura
- Subjects
Montastraea cavernosa ,geography ,Environmental Engineering ,geography.geographical_feature_category ,biology ,Coral ,fungi ,Scleractinia ,Estuary ,Coral reef ,biology.organism_classification ,Anthozoa ,Pollution ,Trace Elements ,Marine pollution ,Oceanography ,Rivers ,River mouth ,Environmental Chemistry ,Environmental science ,Animals ,Waste Management and Disposal ,Reef ,Structure Collapse ,Environmental Monitoring - Abstract
In November 2015, the collapse of the Fundao dam (Minas Gerais, Brazil) carried over 40 × 106 m3 of iron ore tailings into the Doce river and caused massive environmental and socioeconomic impacts across the watershed. The downstream mudslide scavenged contaminants deposited in the riverbed, and several potentially toxic elements were further released through reduction and solubilization of Fe oxy-hydroxides under estuarine conditions. A turbidity plume was formed off the river mouth, but the detection of contaminants’ dispersion in the ocean remains poorly assessed. This situation is specially concerning because Southwestern Atlantic's largest and richest reefs are located 70-250 km to the north of the Doce river mouth, and the legal dispute over the extent of monitoring, compensation and restoration measures are based either on indirect evidence from modeling or on direct evidence from remote sensing and contaminated organisms. Coral skeletons can incorporate trace elements and are considered good monitors of marine pollution, including inputs from open cut mining. Here, we studied a Montastraea cavernosa (Linnaeus 1767) coral colony collected 220 km northward to the river mouth, using X-rays for assessing growth bands and Laser Ablation Inductively Coupled Plasma Mass Spectrometry to recover trace elements incorporated in growth bands formed between 2014 and 2018. A threefold positive Fe anomaly was identified in early 2016, associated with negative anomalies in several elements. Variation in Ba and Y was coherent with the region's sedimentation dynamics, but also increased after 2016, akin to Pb, V and Zn. Coral growth rates decreased after the disaster. Besides validating M. cavernosa as a reliable archive of ocean chemistry, our results evidence wide-reaching sub-lethal coral contamination in the Abrolhos reefs, as well as different incorporation mechanisms into corals’ skeletons.
- Published
- 2021
36. Strategy for phytomanagement in an area affected by iron ore dam rupture: A study case in Minas Gerais State, Brazil
- Author
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Valéria Cristina Palmeira Zago, Beatriz Amanda Watts, and Nathália Corrêa das Dores
- Subjects
010504 meteorology & atmospheric sciences ,Iron ,Mycorrizhae ,Health, Toxicology and Mutagenesis ,Poison control ,010501 environmental sciences ,engineering.material ,Toxicology ,01 natural sciences ,Mining ,Soil ,Aromatic plants ,Chrysopogon ,Mycorrhizae ,Soil Pollutants ,Organic matter ,Biomass ,Structure Collapse ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Topsoil ,biology ,Compost ,Composting ,fungi ,food and beverages ,General Medicine ,Samarco's disaster ,biology.organism_classification ,Pollution ,Tailings ,Phytoremediation ,Chrysopogon zizanioides ,Chemistry ,Biodegradation, Environmental ,chemistry ,Agronomy ,Organic fertilizer ,engineering ,Environmental science ,Brazil - Abstract
In 2015, the Fundão tailing dam collapsed over the district of Bento Rodrigues (Mariana, Minas Gerais, Brazil) causing deaths, hundreds of homeless families and incalculable environmental degradation. Environmentally, economically and socially sustainable strategies are needed for the recovery of the affected areas. The main goal of this study was to evaluate the development, biomass production and toxic mineral elements absorption of three species of aromatic grasses (Chrysopogon zizanioides, Cymbopogon citratus and Cymbopogon winterianus). These three species were planted on polypropylene pots filled with the iron ore tailings collected from the topsoil of the Bento Rodrigues district. The pots were fertilized with increasing doses of organic compost associated with mycorrhizae as a phytomanagement strategy. A 4 × 2 factorial scheme was used. The seedlings were fertilized with four doses of organic compost, with or without mycorrhizae. At the highest dose of the organic compost (2 kg.plant −1 ), the total dry matter (dry matter of the aerial part + dry matter of the roots) for C. zizanioides was 4.5 times higher than the control (tailing only). For C. winterianus and C. Citratus was 3.8 and 2.8 times higher than the control, respectively. Inoculation with mycorrhizae improved biomass production, especially in C. zizanioides. The Fe and Mn levels found in the aerial part of the plants fertilized with organic compost were lower than those just growing on the iron ore tailings for the three species, which suggest that the organic matter apparently helped the plants in the exclusion of the hazardous substances and therefore increased the tolerance to these adverse environmental conditions. C. zizanioides, associated with organic matter and mycorrhizae, would be the recommended species. The proposed phytomanagement strategy can have a significant contribution to the gradual recovery of the affected area and also serve as a source of income for the local population.
- Published
- 2019
37. Study on collapse of steel-reinforced concrete structure caused by self-weight during construction
- Author
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Chung Ming Ho, Jui Lin Peng, Siu Lai Chan, and Yi Pin Chang
- Subjects
Critical load ,business.industry ,Computer science ,Metals and Alloys ,Structure (category theory) ,Collapse (topology) ,020101 civil engineering ,02 engineering and technology ,Building and Construction ,Structural engineering ,Reinforced concrete ,0201 civil engineering ,Construction site safety ,Structure Collapse ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Buckling ,Mechanics of Materials ,Self weight ,business ,Civil and Structural Engineering - Abstract
If a steel-reinforced concrete (SRC) structure has improper construction procedures, it may collapse due to unpredictable construction loads. This study aims to explore construction safety, taking the SRC structure collapse incident of a new factory under construction in Taiwan as an example. Through a second-order analysis, the findings of the study show that the cause of the collapse incident might be that, in the process of construction, the designers failed to consider the overall self-weight of the steel frame, which had exceeded the critical load of the structure at that time. This oversight may have led to a global buckling of the SRC structure. Consequently, the SRC structure collapsed immediately after being struck by a small disturbance. In addition, analysis results of a simplified composite column further reveal the differences between the SRC structure construction procedure and the SS structure construction procedure. When the steel beams and columns of an SRC structure are continuously uplifted and assembled without consideration of the construction progress of the lower-levelRC beams and columns, the self-weight of the upper-levelSRC steel frame might exceed the critical load of the SRC structure under construction, consequently leading to the collapse of the structure. Therefore, in order to prevent the SRC structure from collapsing during construction, proper designs and safe assembly procedures for SRC structures should be formulated to perfectly match the assembly procedure of the steel frame with that of the RC part.
- Published
- 2019
38. Application of deep learning neural network to identify collision load conditions based on permanent plastic deformation of shell structures
- Author
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Guorong Chen, Shaofei Ren, Qijun Chen, Chao Wang, Shaofan Li, and Tiange Li
- Subjects
Artificial neural network ,business.industry ,Computer science ,Applied Mathematics ,Mechanical Engineering ,Deep learning ,Computational Mechanics ,Shell (structure) ,Ocean Engineering ,Structural engineering ,Inverse problem ,Solver ,Collision ,Computational Mathematics ,Structure Collapse ,Computational Theory and Mathematics ,Dynamic loading ,Artificial intelligence ,business - Abstract
In this work, we have developed a novel deep learning inverse solution or identification method to determine and identify the impact load conditions of shell structures based on their final state of damage or inelastic deformation. This artificial intelligence approach offers a practical solution to solve the inverse problem of engineering failure analysis based on final material and structure damage state and permanent plastic deformation. More precisely, the machine learning inverse problem solver may provide a practical solution to characterize failure load parameters and conditions based on the final permanent plastic deformation distribution of the shell structure that is under examination. In this work, we have demonstrated that the proposed deep learning method can accurately identify a “practically unique” static loading condition as well as the impact dynamic loading condition for a hemispherical shell structure based the permanent plastic deformation after the impact event as the forensic signatures. The data-driven based method developed in this work may provide a powerful tool for forensically diagnosing, determining, and identifying damage loading conditions for engineering structures in various accidental failure events, such as car crashes, pressure vessel failure, or thin-walled infrastructure structure collapses. The machine learning inverse problem solver developed here in this work may have potential impacts on general forensic material and structure failure analysis based on final permanent plastic deformations.
- Published
- 2019
39. Far-reaching cytogenotoxic effects of mine waste from the Fundão dam disaster in Brazil
- Author
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José Marcello Salabert de Campos, Nathan Barros, Larissa Fonseca Andrade-Vieira, Rafael M. Almeida, Raquel Mendonça, Guilherme M. Azevedo, Gabrielle Rabelo Quadra, Simone Jaqueline Cardoso, Milene Miranda Praça-Fontes, Yago Guida, J.R. Thomaz, Adan Santos Lino, Olaf Malm, and Fábio Roland
- Subjects
Environmental Engineering ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,Mitosis ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Mining ,Dam Collapse ,Disasters ,Rivers ,Onions ,Environmental Chemistry ,Structure Collapse ,0105 earth and related environmental sciences ,Chromosome Aberrations ,Hydrology ,River sediment ,Public Health, Environmental and Occupational Health ,Trace element ,Sediment ,Environmental Exposure ,General Medicine ,General Chemistry ,Particulates ,Pollution ,Trace Elements ,020801 environmental engineering ,Wastewater ,Environmental science ,Brazil ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
On November 2015, one of Brazil's most important watersheds was impacted by the mine waste from Fundao dam collapse in Mariana. The mine waste traveled over 600 km along the Doce River before reaching the sea, causing severe devastation along its way. Here we assessed trace element concentrations and cytogenotoxic effects of the released mine waste. Water samples were collected along the Doce River ten days after the disaster in two impacted sites and one non-impacted site. Sampling points were located hundreds of kilometers downstream of the collapsed dam. Water samples were used for trace element quantification and to run an experiment using Allium cepa to test cytogenotoxicity. We found extremely high concentrations of particulate Fe, Al, and Mn in the impacted sites. We observed cytogenotoxic effects such as alterations in mitotic and phase indexes, and enhanced frequency of chromosomal aberrations. Our results indicate interferences in the cell cycle in impacted sites located hundreds of kilometers downstream of the disaster. The environmental impacts of the dam collapse may not only be far-reaching but also very likely long-lasting, because the mine waste may persist in the Doce River sediment for decades.
- Published
- 2019
40. A Deep Learning-Based Computational Algorithm for Identifying Damage Load Condition: An Artificial Intelligence Inverse Problem Solution for Failure Analysis
- Author
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Guorong Chen, Tiange Li, Shaofei Ren, Shaofan Li, and Qijun Chen
- Subjects
business.industry ,Computer science ,Deep learning ,0211 other engineering and technologies ,02 engineering and technology ,Plasticity ,Inverse problem ,Residual ,computer.software_genre ,01 natural sciences ,Computer Science Applications ,010101 applied mathematics ,Identification (information) ,Structure Collapse ,Data acquisition ,Modeling and Simulation ,021105 building & construction ,State (computer science) ,Artificial intelligence ,Data mining ,0101 mathematics ,business ,computer ,Software - Abstract
In this work, we have developed a novel machine (deep) learning computational framework to determine and identify damage loading parameters (conditions) for structures and materials based on the permanent or residual plastic deformation distribution or damage state of the structure. We have shown that the developed machine learning algorithm can accurately and (practically) uniquely identify both prior static as well as impact loading conditions in an inverse manner, based on the residual plastic strain and plastic deformation as forensic signatures. The paper presents the detailed machine learning algorithm, data acquisition and learning processes, and validation/verification examples. This development may have significant impact on forensic material analysis and structure failure analysis, and it provides a powerful tool for material and structure forensic diagnosis, determination, and identification of damage loading conditions in accidental failure events, such as car crashes and infrastructure or building structure collapses.
- Published
- 2018
41. Hydrostatic and shock-initiated instabilities in double-hull composite cylinders
- Author
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Arun Shukla, Michael Pinto, and Nicholas A. DeNardo
- Subjects
Materials science ,Mechanical Engineering ,Hydrostatic pressure ,Implosion ,02 engineering and technology ,Mechanics ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Pressure vessel ,Overpressure ,Cylinder (engine) ,law.invention ,Structure Collapse ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,law ,Dynamic pressure ,Hydrostatic equilibrium ,0210 nano-technology - Abstract
The dynamic collapse of hollow and foam-filled double hull composite cylinders is investigated experimentally. Concentric carbon-fiber/epoxy double cylinders with and without parametrically-graded PVC foam cores are collapsed in a large-diameter pressure vessel under critical hydrostatic pressure as well sub-critical hydrostatic pressure and shock loading. Dynamic pressure data is used in conjunction with underwater Digital Image Correlation (DIC) to determine the effect of the double hull structure on implosion mechanics. Buckling initiation and overall collapse behavior are studied, as well as the pressure pulses released during the dynamic event. Incidents of partial collapse are reported, in addition to cases where the entire structure collapses. The physical mechanisms responsible for this behavior are identified, and the time between inner and outer cylinders collapsing is related to buckling phase angle. For hydrostatically initiated implosions, results show heavier foam cores increase critical collapse pressure linearly with foam crushing strength. Pressure pulses emitted during collapse are shown to occur in distinct phases, with an additional under- and overpressure region present if the inner cylinder collapses. Impulse is demonstrated to be primarily a function of collapse pressure, with energy released increasing with core density. For shock initiated cases, specimens are shown to implode below their natural collapse pressure when subject to explosive loading, with the addition of a foam core substantially increasing structural stability and sometimes preventing collapse. Specimens with foam cores are shown to undergo prolonged vibrations before collapsing. Post-mortem specimens are used to elucidate fracture and failure mechanisms.
- Published
- 2018
42. Anchoring K+ in Li+ Sites of LiNi0.8 Co0.15 Al0.05 O2 Cathode Material to Suppress its Structural Degradation During High-Voltage Cycling
- Author
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Zhixing Wang, Huajun Guo, Jiexi Wang, Weihua Gui, Ning Chen, Xinhai Li, Junkai Zhao, and Guochun Yan
- Subjects
Phase transition ,Materials science ,Anchoring ,High voltage ,02 engineering and technology ,Structural degradation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Structure Collapse ,General Energy ,Cathode material ,Composite material ,0210 nano-technology ,Cycling - Published
- 2018
43. Marine benthic communities affected by the Doce River (southwestern Atlantic): Baseline before a mining disaster
- Author
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Soraya Guimarães Rabay, Cristiane Xerez Barroso, Valesca Paula Rocha, Luis Ernesto Arruda Bezerra, Helena Matthews-Cascon, Marcelo de Oliveira Soares, and Ana Karla Moreira
- Subjects
Aquatic Organisms ,010504 meteorology & atmospheric sciences ,Fauna ,010501 environmental sciences ,Aquatic Science ,Oceanography ,01 natural sciences ,Mining ,Dam Collapse ,Disasters ,Rivers ,Abundance (ecology) ,Crustacea ,River mouth ,Animals ,Ecosystem ,Structure Collapse ,0105 earth and related environmental sciences ,geography ,geography.geographical_feature_category ,Tailings dam ,Continental shelf ,Polychaeta ,Biodiversity ,Pollution ,Mollusca ,Benthic zone ,Multivariate Analysis ,Environmental science ,Seasons ,Species richness ,Brazil ,Environmental Monitoring - Abstract
Prior to Brazil's worst environmental disaster, caused by a mining dam collapse, we had carried out a study of the marine benthic macrofauna (11–51 m depth) under the influence of the Doce River. Our results showed significant diversity, in which mollusks, polychaetes, and crustaceans had the highest frequency, density, and abundance, represented by 162 families in summer and 173 in winter. Our results suggested that richness, abundance, and diversity increase with distance from the coast. Furthermore, with increasing distance from the coast and river mouth, in addition to increasing depth, there was a differentiation in composition and abundance. Multivariate analyses showed depth, carbonate, and organic matter as important factors that explain variations in composition and diversity across the continental shelf. The results could provide an invaluable baseline for measuring the effects on shallow and mesophotic communities of one of the largest tailings dam failures worldwide.
- Published
- 2018
44. New insights into metal(loid) dynamics in the Doce River estuary (Brazil) after a massive iron ore-processing tailing dam collapse
- Author
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Daniel Santos Mulholland, Jeremie Garnier, Daniel Ferreira Araújo, Welton Climaco Duarte, Gael Monvoisin, Cecile Quantin, Remi Freydier, and Patrick Seyler
- Subjects
Health, Toxicology and Mutagenesis ,Iron ,General Medicine ,Pollution ,Lead ,Rivers ,Metals, Heavy ,Environmental Chemistry ,Humans ,Estuaries ,Brazil ,Structure Collapse ,Water Pollutants, Chemical ,Cadmium ,Environmental Monitoring - Abstract
The present study investigated metal and metalloid dynamics in the estuarine water of the Doce River (Brazil) after the collapse of an iron ore-processing tailing dam in 2015. Spectroscopic and isotopic techniques were applied to bring new insights into the effects of the dam failure on the dynamics and hazardousness of particulate and dissolved metal(loid) concentrations along the fluvial-estuarine continuum. Spectroscopic analysis showed that the suspended particulate matter (SPM) of the Doce River estuary consisted of a combination of soil-delivered particles and fine tailing mud particles with small amounts of coarse tailing mud Fe oxides (~150-μm width). Enrichment and contamination factors showed that the dam failure increased particulate Fe, Pb, Cd, and As, and dissolved Pb concentrations. Total concentrations of As (15 μg/L), Pb (30 μg/L), Cd (8 μg/L), and Cr (105 μg/L) increased up to values higher than quality and regulatory guidelines. Human health risk assessment showed that local communities are exposed to a potentially chronic Cr noncarcinogenic effects, although Cr high concentrations were not linked with the dam failure by this study. The particulate Pb isotope signatures reported herein (
- Published
- 2021
45. Ecological thresholds of periphytic communities and ecosystems integrity in lower Doce River basin
- Author
-
Stéfano Zorzal-Almeida and Valéria de Oliveira Fernandes
- Subjects
Hydrology ,geography ,Environmental Engineering ,geography.geographical_feature_category ,River ecosystem ,Aquatic ecosystem ,Lake ecosystem ,Drainage basin ,Pollution ,Macrophyte ,Rivers ,River mouth ,Environmental Chemistry ,Environmental science ,Ecosystem ,Eutrophication ,Waste Management and Disposal ,Structure Collapse ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Freshwater biodiversity has been impacted by several stressors such as eutrophication, turbidity and metals. Besides these frequent impacts, large-scale accidents occasionally affect aquatic systems, input an intense load of contaminants to the water bodies, as in the case of the Fundao tailing dam collapse (Brazil), which launched millions of meters cubic of iron ore tailing in the Doce River Basin. Our aim in this study was to assess how much stress the environmental conditions of lentic and lotic environments in the lower region of this basin impact the periphytic community. In addition, we intend to verify whether the limits of changes of the periphytic communities agreed with Brazilian legislation for the protection of aquatic life. For that, monthly samplings were carried out in seven sampling stations in lentic environments and five in lotic environments, including the Doce River channel, between October/2018 and March/2021 (except in October/2019). Concentrations of metals (iron, aluminum, manganese and chromium), total nitrogen, total phosphorus, conductivity, and suspended particulate material were determined. The periphytic community was collected from natural substrates (macrophytes or pebbles) and quantified by the sedimentation chamber method. From these data, thresholds of concentrations of variables that caused changes in periphytic communities were determined by the Threshold Indicator Taxa ANalysis (TITAN). We concluded that evidence of chronic impact of iron ore tailing should be revealed and that the standards established by Brazilian legislation may be incompatible with the protection of aquatic life. Moreover, we found that the Doce River mouth and surrounding environments were the most stressful environments for the periphytic communities.
- Published
- 2021
46. Simulating the effect of check dam collapse in a debris-flow channel
- Author
-
Tommaso Baggio and Vincenzo D'Agostino
- Subjects
Environmental Engineering ,Consolidation (soil) ,Flood myth ,Erosion control ,Check dam collapse ,Debris flow ,Pollution ,Debris ,Disasters ,Italy ,Propagation modelling ,Erosion ,Environmental Chemistry ,Geotechnical engineering ,Bed erosion ,Waste Management and Disposal ,Geology ,Structure Collapse ,Communication channel ,Check dam - Abstract
Sequences of erosion control/consolidation check dams are the most widespread channel countermeasure in the European Alps. Some of them were built in the past based on ancient technologies. Nowadays they may not be fully adequate to mitigate the debris-flow/flood events that are becoming more frequent and intense. Consequently, there is the remote possibility that they could fail with disastrous consequences as observed in some cases. A reliable methodology to reproduce the effect of check dam collapse has not yet proposed. Therefore the aim of this study is to define a procedure to simulate the effect of check dam collapse in a debris-flow event. In this study we analysed the catastrophic debris flow occurred in the Rotian channel (Italian Alps) during which a series of check dams collapsed magnifying the event and causing severe damages. With the aid of field data we reconstructed the event and used the simulation tool r.avaflow to reproduce the debris flow. We then defined three scenarios to simulate the event: (A) debris-flow propagation over an erodible channel; (B) propagation on a rigid channel bed combined with the release of impulsive masses to isolate the analysis of the effect of check dam collapse; (C) a combination of the previous scenarios. The simulation performance was assessed analysing the pre- and post-event LiDAR surveys. Results showed that the C scenario accurately reproduced the observed debris-flow erosion pattern. In particular, we found out that most of the entrained debris volume derived from bed erosion rather than the sediment retained by check dams. The method adopted which composes the contribution of bed erosion and check dam collapse could be of particular relevance for residual risk estimation when mitigation structures are old and may fail with potential disastrous consequences.
- Published
- 2021
47. Forest restoration methods, seasonality, and penetration resistance does not influence aboveground biomass stock on mining tailings in Mariana, Brazil
- Author
-
ÍTALO F. CAMPANHARO, SEBASTIÃO V. MARTINS, PEDRO M. VILLA, GABRIEL C. KRUSCHEWSKY, ANDREIA A. DIAS, and FABIO NABETA
- Subjects
resilient mitigation ,0106 biological sciences ,Multivariate statistics ,Fundão dam ,Science ,Forests ,010603 evolutionary biology ,01 natural sciences ,Mining ,Dam Collapse ,Forest restoration ,medicine ,penetration resistance ,Biomass ,restoration ecology ,Restoration ecology ,Structure Collapse ,Hydrology ,Multidisciplinary ,Tailings dam ,Resistance (ecology) ,04 agricultural and veterinary sciences ,Seasonality ,medicine.disease ,Tailings ,040103 agronomy & agriculture ,site effects ,0401 agriculture, forestry, and fisheries ,Environmental science ,Brazil ,Environmental Monitoring - Abstract
The restoration methods applied on the areas affected by the Fundão tailings dam collapse have a high priority in Mariana region. We evaluated the effect of different restoration methods and site preparation techniques, depth and seasonality on penetration resistance of tailings, and how these predictors affect tree aboveground biomass in areas affected by the Fundão dam collapse in Mariana, Brazil. No significant differences in penetration resistance and aboveground biomass between treatments were observed, but significant differences were observed between seasonal periods. The main univariate model explained the significant effects of depth and seasonality, mainly by a negatively wet effect on penetration resistance. According to the best models (univariate and multivariate) were those that had depth as a predictor. This study showed how penetration resistance can be an indicator to select the best period for restoration process in areas affected by the collapse of the Fundão dam, but no limit to the aboveground biomass recovery on tailing.
- Published
- 2021
48. Ecological trap for seabirds due to the contamination caused by the Fundão dam collapse, Brazil
- Author
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Guilherme Tavares Nunes, Amédée Roy, Aline Barbosa Silva, Patrícia Gomes Costa, Márcio Amorim Efe, Juliana Vallim Gaiotto, Sophie Bertrand, Fiorella Vilela, Adalto Bianchini, Cindy Tavares Barreto, and Leandro Bugoni
- Subjects
Environmental Engineering ,Biologging ,Ecological niche ,Foraging ,Mining dam failure ,Dam Collapse ,Birds ,Rivers ,biology.animal ,parasitic diseases ,Animals ,Humans ,Environmental Chemistry ,Waste Management and Disposal ,Ecosystem ,Structure Collapse ,Stable isotopes ,Trace elements ,geography ,geography.geographical_feature_category ,biology ,Continental shelf ,Ecology ,fungi ,Pollution ,Tailings ,Habitat ,Environmental science ,Seabird ,Ecological trap ,Brazil - Abstract
Human-induced rapid environmental changes can disrupt habitat quality in the short term. A decrease in quality of habitats associated with preference for these over other available higher quality is referred as ecological trap. In 2015, the Fundao dam containing iron mining tailings, eastern Brazil, collapsed and released about 50 million cubic meters of metal-rich mud composed by Fe, As, Cd, Hg, Pb in three rivers and the adjacent continental shelf. The area is a foraging site for dozens of seabird and shorebird species. In this study, we used a dataset from before and after Fundao dam collapse containing information on at-sea distribution during foraging activities (biologging), dietary aspects (stable isotopes), and trace elements concentration in feathers and blood from three seabird species known to use the area as foraging site: Phaethon aethereus, Sula leucogaster, and Pterodroma arminjoniana. In general, a substantial change in foraging strategies was not detected, as seabirds remain using areas and food resources similar to those used before the dam collapse. However, concentration of non-essential elements increased (e.g., Cd and As) while essential elements decreased (e.g., Mn and Zn), suggesting that the prey are contaminated by trace elements from tailings. This scenario represents evidence of an ecological trap as seabirds did not change habitat use, even though it had its quality reduced by contamination. The sinking-resuspension dynamics of tailings deposited on the continental shelf can temporally increase seabird exposure to contaminants, which can promote deleterious effects on populations using the region as foraging sites in medium and long terms.
- Published
- 2022
49. Using Nd Sr isotopes in suspended sediments in the Abrolhos coral-reef (SW Atlantic, Brazil) to assess potential contamination from the 2015 Fundão dam collapse
- Author
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João R.C. de Barcellos, Araceli V. Flores, Bruno Vinicius Ximenes de Oliveira, José Carlos Sícoli Seoane, Marcus Vinícius Vaughan Jennings Licínio, Ramon Silva dos Santos, Carla Cristine Aguiar Neto, Eduardo Delfino Sodré, Flávia Guebert, Sérgio J. Gonçalves Junior, Caroline Peixoto, Gabriel Paravidini, Joselito Nardy Ribeiro, Marcelino J. Anjos, Claudio de Morisson Valeriano, Catia F Barbosa, Fabio Negrão, Elaine Alves dos Santos, Heitor Evangelista, Monica Heilbron, Newton de Magalhães Neto, Renato Campello Cordeiro, and Madson de Godoi Pereira
- Subjects
Geologic Sediments ,geography ,Environmental Engineering ,geography.geographical_feature_category ,Coral Reefs ,Discharge ,Sediment ,Context (language use) ,Coral reef ,Anthozoa ,Pollution ,Isotopic signature ,Oceanography ,Isotopes ,River mouth ,Animals ,Environmental Chemistry ,Waste Management and Disposal ,Sediment transport ,Reef ,Brazil ,Structure Collapse ,Geology - Abstract
The Abrolhos bank is home of the richest coral reef system of the Southwestern Atlantic, where endemic coral species are found. It has been reported that Abrolhos' corals are under intense stress due to increasing of Marine Heat Waves during the last decades. Additionally, anthropic interventions along the adjacent coastal regions are a factor of concern since they contribute to the increase in the sediment load and to organic debris input in the reef domain. In November 2015, the collapse of the Fundao mining tailings dam resulted in the release of approximately 50 million m3 of iron oxide and quartz-rich slurry into the Doce River. Aiming at using a fingerprint of the tailings and to assess the presence of traces of the Fundao dam material from this event on the Abrolhos bank, this work presents new 87Sr/86Sr and 143Nd/144Nd isotope ratios of marine suspended sediment samples collected between 2016 and 2020 from a network of sediment traps throughout the reef and complementary suspended material at sea. In parallel, we monitored meteo-oceanographic parameters and modeled surface marine currents as an attempt to identify the sediment transport between the Doce River mouth and Abrolhos bank. The r isotopes were used as provenance proxies based on the fact that minerals and rocks tend to have specific isotopic signatures reflecting their own geological derivation. In this context, the isotopic ratios of various potential regional sources for the sedimentation in Abrolhos bank were evaluated. Our monitoring and isotopic measurements indicate that Doce River signatures are detected at Abrolhos bank, following the seasonal Doce River discharge at sea. Isotopic signature of Doce River at Abrolhos bank was also observed during the austral winter (July–August) when cold fronts migrate at the Brazilian coast with higher frequency and energy.
- Published
- 2022
50. When DNA profiling is not enough? A case of same-sex siblings identification by odontological assessment after gas explosion-related building collapse
- Author
-
Rafał Skowronek, Krystian Rygol, Marcin Tomsia, and Kornelia Droździok
- Subjects
Younger sister ,Permanent dentition ,Explosions ,01 natural sciences ,Building collapse ,Pathology and Forensic Medicine ,03 medical and health sciences ,0302 clinical medicine ,Gas explosion ,Medicine ,Humans ,030216 legal & forensic medicine ,Child ,Structure Collapse ,business.industry ,Siblings ,010401 analytical chemistry ,DNA Fingerprinting ,0104 chemical sciences ,Issues, ethics and legal aspects ,DNA profiling ,Child, Preschool ,Same sex ,Identification (biology) ,Thermal damage ,Female ,business ,Demography ,Forensic Dentistry - Abstract
We aimed to show the usefulness of odontological assessment in forensic investigation. Charred remains of two female siblings were found in a collapsed building after a gas explosion. Due to thermal damage of the bodies, the facial characteristics, fingerprints, height and weight could not be used to distinguish between siblings. Since the victims, 4 and 10-year-old, died simultaneously and all personal belongings were lost, DNA profiling performed with their parents only confirmed the relationship. As dental charts of siblings were not found, we could not easily discriminate which remains would be of the elder and which of the younger sister. The odontological examination enabled us to discriminate between the siblings based on differences in deciduous and permanent dentition. We conclude that although DNA profiling is becoming a standard method of personal identification in some cases it should be supported by additional methods to deliver comprehensive forensic reports.
- Published
- 2020
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