Occupational multimorbidity in the nickel industry workers.

The purpose of the study was to obtain new data on the causes, development, prevalence and nature of occupational multimorbidity in the nickel industry workers. We extracted data from the register of occupational disease and intoxication cases in the population of the Murmansk region and the Krasnoyarsk Territory in 2007-2021. In 2007-2021, 24.6% of nickel industry workers with newly diagnosed occupational diseases developed a multimorbid pathology. Its prevalence rose from 0% in 2007 to 83.3% in 2021, and the number of occupational diseases increased by 3.17 times. Two diagnoses were found in 66 (14.9%), three in 22 (5.0%), four in fifteen (3.4%), five in eleven (2.5%), and six in three (0.7%) employees. Respiratory and musculoskeletal diseases were the most prevalent disorders, accounting for 31.5% and 23.0% of cases, respectively. Occupational multimorbidity resulted from the increased combined exposure to occupational hazards, outdated technological processes, and the working conditions in the finished product cleaners and crane operators. Multimorbid diseases can be better prevented with improvement in working conditions and better quality of periodic medical examinations.

Innovative technologies to enhance oil recovery.

The processes for extracting and refining edible oils are well-established in industry at different scales. However, these processing lines encounter inefficiencies and oil losses when recovering crude or refined oil. Palm oil and olive oil extraction methods are used mainly as a combination of physical, thermal, and centrifugal methods to recover crude oil, which results in oil losses in the olive pomace or in palm oil effluents. Seed oils generally require a seed steam conditioning, and cooking stage, followed by physical oil recovery through an inefficient expeller. Most of the crude oil remaining in the expeller cake is then recovered by hexane. Crude seed oil is further refined in stages that also undergo oil losses. This chapter provides an overview of innovative technologies using microwave, ultrasound, megasonic and pulsed electric field energies, which can be used in the above-mentioned crude and refined oil processes to improve oil recovery. This chapter describes traditional palm oil, olive oil, and seed oil processes, as well as the specific process interventions that have been tested with these technologies. The impact of such technology interventions on oil quality is also summarized.

How to optimize dust pollution control in opencast coal mines: Analysis of a joint social regulation model based on evolutionary game theory.

The carbon peaking and carbon neutrality goals drive innovation in pollution governance systems, unleashing the potential of social supervisory forces to achieve coordinated governance by multiple stakeholders. In order to improve dust pollution control in opencast coal mines, this study combines prospect theory with evolutionary game theory, analyzing the evolutionary game process of coordinated governance activities of coal mining enterprises, local regulators, and social camps in the management of dust pollution against the backdrop of national supervisions. The research indicates that the perceived value of dust pollution has a significant impact on the strategic choices of the three agents involved in the game. Coal mining enterprises tend to be risk averse, and by reducing the cost of dust pollution control and increasing the additional benefits of pollution control, it can promote pollution control behavior by coal mining enterprises. Local regulators are also risk averse, but not sensitive to risk benefits. Strengthening pollution subsidy incentives and environmental fines can help promote dust pollution control behavior by coal mining enterprises. However, increasing the strength of the rewards strategy is not conducive to local regulators' own regulatory responsibilities, and environmental fines have limited binding effects. The strategic choices of social camps' supervision have a restrictive effect on the strategic choices of coal mining enterprises and local regulators, promoting the evolution of equilibrium results in the direction of maximizing social benefits. When coal mining enterprises actively governance pollution, local regulators strictly regulated, and social camps do not monitor, the system reaches its optimal equilibrium state. The research results clarify the mechanism and specific effects of social supervision of opencast coal mine dust pollution control, guide the participation of the public in dust pollution control, and regulate the behavior strategies of coal mining enterprises and local regulators, providing the scientific basis for management.

Working Alone and/or in Remote Locations: Opportunities to Prevent the Risk of Fatality From Cardiovascular Events in Oil and Gas Extraction Workers.

OBJECTIVE: The aim of the study is to explore personal and work factors related to fatal cardiac events among oil and gas extraction (OGE) workers. METHODS: The National Institute for Occupational Safety and Health Fatalities in Oil and Gas Extraction database was reviewed to identify fatal cardiac events among OGE workers from 2014 through 2019. A case series design was used to review case files, provide descriptive statistics, and summarize the findings. RESULTS: There were 75 fatalities identified, including 55 (73%) with sufficient information for review. Of the 55 workers, 18 (33%) worked alone. Thirty-six fatal cardiac events (66%) were unwitnessed by a coworker. Toxicology findings suggested some possible exposures to hydrogen sulfide or hydrocarbon gases or vapors. Missing data were common. CONCLUSIONS: This study identified the need for cardiovascular disease prevention and treatment, emergency preparedness, lone worker programs, medical screening, and enhanced exposure control in the OGE industry.

El estado de excepción como paradigma político del extractivismo / The state of exception as a paradigm politician of extractivism

Este artículo tiene como objetivo analizar las formas en que los movimientos sociales que enfrentan el actual modelo de extractivismo ­ basado en la acumulación por despojo ­ actúan contra la degradación ambiental y la militarización de los territorios explotados por esta actividad. Por lo tanto, presenta un debate conceptual sobre el extractivismo, no sólo como parte de la acumulación típica del capitalismo financiero, sino también como una reanudación, bajo nuevas bases, del colonialismo, ya que los pueblos originarios ­ especialmente aquellos que habitan la zona del no-ser ­ son los principales obstáculos para el despojo. Finalmente, enfatiza que los movimientos sociales no se restringen a las tácticas tradicionales adoptadas en otros momentos de resistencia, renovando sus formas de lucha.

Políticas desenvolvimentistas e mulheres quebradeiras de coco babaçu: capturas contemporâneas / Developmentalist policies and babassu coconut-breaking women: contemporary catches / Políticas desarrollistas y las mujeres que rompen coco babaçu: capturas contemporáneas

Este estudo propõe analisar as relações e os processos de subjetivação de mulheres quebradeiras de coco babaçu decorrentes das intervenções de políticas desenvolvimentistas em seus territórios de vida e reverberações no Movimento Interestadual de Quebradeiras de Coco Babaçu (MIQCB). Sob a perspectiva ético-estético-política da Cartografia, acompanhamos as narrativas das histórias de vida de 24 mulheres, suas atividades cotidianas e eventos do MIQCB, também analisamos os documentos das políticas. Entendemos que, ao passo que tais políticas de desenvolvimento rural contribuem para a melhoria das condições de vida, em termos materiais e simbólicos, elas também produzem ressonâncias relacionadas ao modo de subjetivação do tipo "empresário de si", que agenciam seus modos de viver, de produzir e de se relacionar consigo e com os outros na lógica capitalista neoliberal. A resistência às capturas neoliberais também estão presentes ao ampliarem as mobilizações coletivas do próprio movimento, articulando com outros na produção de um "comum".(AU)

This study proposes to analyze the relations and the processes of subjectivation of babassu coconut-breaker women arising from developmental policy interventions in their territories of life and reverberations in the Babassu Coconut-breaker Interstate Movement (MIQCB). From the ethical-aesthetic-political perspective of Cartography, we followed the narratives of the life stories of 24 women, their daily activities and promoted events by MIQCB, we also analyzed the policy documents. We understand that while these policies of rural development contribute to improve the living conditions, in material and symbolic terms, they also produce resonances related to the "self-entrepreneur" mode of subjectivation, which has been handling their ways of living, producing, and relating to themselves and others in the neoliberal capitalist logic. Resistance to neoliberal captures is also present as they expand the collective mobilizations of the movement itself, articulating with others, in the production of a "common."(AU)

Este estudio tiene como objetivo analizar los procesos de subjetivación de las mujeres que rompen coco babaçu que surgen de las intervenciones de las políticas de desarrollo en sus territorios de vida y las reverberaciones en el Movimiento Interestadual de las Mujeres que Rompen Coco Babaçu (MIQCB). Desde la perspectiva ético-estético-política de la Cartografía, seguimos las narraciones de las historias de vida de 24 mujeres, sus actividades diarias y eventos del MIQCB, y también analizamos los documentos de las políticas. Si bien estas políticas han contribuido a mejorar las condiciones de vida de las mujeres, en términos materiales y simbólicos, también han producido resonancias del modo de subjetivación "autoempresarial", que ha agenciado sus formas de vivir, producir y relacionarse consigo mismas y con los demás en la lógica capitalista neoliberal. La resistencia a las capturas neoliberales también está presente cuando amplían las movilizaciones colectivas del propio movimiento, articulándose con otros en la producción de un "común".(AU)

Updated Italian cohort data continues to confirm lack of mesothelioma risk in pooled cohort of international cosmetic talc miners and millers.

OBJECTIVES: To assess potential mesothelioma risk following inhalation of cosmetic talc, we updated previous iterations of a pooled cohort analysis, post-study statistical power analysis, and confidence interval function analysis for a pooled cohort of international cosmetic talc miners/millers given new Italian cohort data. METHODS: Five cohorts of cosmetic talc miners/millers were pooled. Expected numbers of mesotheliomas for each cohort were reported by the original authors. We based our post-study statistical power analysis on an a priori one-sided significance level of 0.05, and exact Poisson and approximate distribution probabilities. To evaluate the confidence interval function for the observed pooled mesothelioma standardized mortality ratios (SMRs), we calculated the probability for the upper 100(1-2α)% confidence limit that equals various SMRs of interest. RESULTS: The pooled cohorts generated a total observation time of 135,524.38 person-years. Overall, 4.14 mesotheliomas were expected (mid-value estimate), though only one case of mesothelioma has been confirmed in the pooled cohort to date. We calculated 71% and 87% post-study power to detect a 2.5-fold or greater and a 3.0-fold or greater increase in mesothelioma, respectively. Our complimentary confidence interval function analysis demonstrated that the probability that the true mesothelioma SMR for the pooled cohort was at or above 2.0 or at or above 3.0 was 0.00235 and 0.00005, respectively. CONCLUSIONS: Based on the updated results of our various analyses, the current epidemiological evidence from cosmetic talc miner/miller cohort studies continues to not support the hypothesis that the inhalation of cosmetic talc is associated with an increased risk of mesothelioma.

Dynamics of severe accidents in the oil & gas energy sector derived from the authoritative ENergy-related severe accident database.

Organized into a global network of critical infrastructures, the oil & gas industry remains to this day the main energy contributor to the world's economy. Severe accidents occasionally occur resulting in fatalities and disruption. We build an oil & gas accident graph based on more than a thousand severe accidents for the period 1970-2016 recorded for refineries, tankers, and gas networks in the authoritative ENergy-related Severe Accident Database (ENSAD). We explore the distribution of potential chains-of-events leading to severe accidents by combining graph theory, Markov analysis and catastrophe dynamics. Using centrality measures, we first verify that human error is consistently the main source of accidents and that explosion, fire, toxic release, and element rupture are the principal sinks, but also the main catalysts for accident amplification. Second, we quantify the space of possible chains-of-events using the concept of fundamental matrix and rank them by defining a likelihood-based importance measure γ. We find that chains of up to five events can play a significant role in severe accidents, consisting of feedback loops of the aforementioned events but also of secondary events not directly identifiable from graph topology and yet participating in the most likely chains-of-events.

Impact of extractive industries on malaria prevalence in the Democratic Republic of the Congo: a population-based cross-sectional study.

Extraction of natural resources through mining and logging activities provides revenue and employment across sub-Saharan Africa, a region with the highest burden of malaria globally. The extent to which mining and logging influence malaria transmission in Africa remains poorly understood. Here, we evaluate associations between mining, logging, and malaria in the high transmission setting of the Democratic Republic of the Congo using population-representative malaria survey results and geographic data for environmental features and mining and logging concessions. We find elevated malaria prevalence among individuals in rural areas exposed to mining; however, we also detect significant spatial confounding among locations. Upon correction, effect estimates for mining and logging shifted toward the null and we did not find sufficient evidence to detect an association with malaria. Our findings reveal a complex interplay between mining, logging, space, and malaria prevalence. While mining concessions alone may not drive the high prevalence, unobserved features of mining-exposed areas, such as human migration, changing vector populations, or parasite genetics, may instead be responsible.

Identification of tolerance levels on the cold-water coral Desmophyllum pertusum (Lophelia pertusa) from realistic exposure conditions to suspended bentonite, barite and drill cutting particles.

Cold-water coral (CWC) reefs are numerous and widespread along the Norwegian continental shelf where oil and gas industry operate. Uncertainties exist regarding their impacts from operational discharges to drilling. Effect thresholds obtained from near-realistic exposure of suspended particle concentrations for use in coral risk modeling are particularly needed. Here, nubbins of Desmophyllum pertusum (Lophelia pertusa) were exposed shortly (5 days, 4h repeated pulses) to suspended particles (bentonite BE; barite BA, and drill cuttings DC) in the range of ~ 4 to ~ 60 mg.l-1 (actual concentration). Physiological responses (respiration rate, growth rate, mucus-related particulate organic carbon OC and particulate organic nitrogen ON) and polyp mortality were then measured 2 and 6 weeks post-exposure to assess long-term effects. Respiration and growth rates were not significantly different in any of the treatments tested compared to control. OC production was not affected in any treatment, but a significant increase of OC:ON in mucus produced by BE-exposed (23 and 48 mg.l-1) corals was revealed 2 weeks after exposure. Polyp mortality increased significantly at the two highest DC doses (19 and 49 mg.l-1) 2 and 6 weeks post-exposure but no significant difference was observed in any of the other treatments compared to the control. These findings are adding new knowledge on coral resilience to short realistic exposure of suspended drill particles and indicate overall a risk for long-term effects at a threshold of ~20 mg.l-1.

Preparation and related properties of geopolymer solidified uranium tailings bodies with various fibers and fiber content.

Uranium tailing ponds are a potential major source of radioactive pollution. Solidification treatment can control the diffusion and migration of radioactive elements in uranium tailings to safeguard the surrounding ecological environment. A literature review and field investigation were conducted in this study prior to fabricating 11 solidified uranium tailing samples with different proportions of PVA fiber, basalt fiber, metakaolin, and fly ash, and the weight percentage of uranium tailings in the solidified body is 61.11%. The pore structure, volume resistivity, compressive strength, radon exhalation rate variations, and U(VI) leaching performance of the samples were analyzed. The pore size of the solidified samples is mainly between 1 and 50 nm, the pore volume is between 2.461 and 5.852 × 10-2 cm3/g, the volume resistivity is between 1020.00 and 1937.33 Ω·m, and the compressive strength is between 20.61 and 36.91 MPa. The radon exhalation rate is between 0.0397 and 0.0853 Bq·m-2·s-1. The cumulative leaching fraction of U(VI) is between 2.095 and 2.869 × 10-2 cm, and the uranium immobilization rate is between 83.46 and 85.97%. Based on a comprehensive analysis of the physical and mechanical properties, radon exhalation rates, and U(VI) leaching performance of the solidified samples, the basalt fiber is found to outperform PVA fiber overall. The solidification effect is optimal when 0.6% basalt fiber is added.

Estudios del despoblamiento rural en Chile: aproximaciones hacia un marco analítico desde la ecología política latinoamericana / Estudos do despovoamento rural no Chile: abordagens para um quadro analítico da ecologia política latino-americana / Studies of rural depopulation in Chile: approaches towards an analytical framework from Latin American political ecology

Resumen El objetivo de este este trabajo fue hacer una revisión documental sobre el despoblamiento rural para ubicar sus principales antecedentes, corrientes y visiones de estudio en Latinoamérica y otros espacios geográficos, con énfasis en Chile para exponer la forma en que la relación entre extractivismo y despoblamiento rural ha sido tratada con la intención de contrastar los resultados con los insumos teóricos de la ecología política latinoamericana y de plantear un análisis integral de este fenómeno. Los resultados muestran que en Chile los factores que han impulsado históricamente el despoblamiento de zonas rurales fueron la dictadura militar, los planes de ordenamiento territorial, industrialización y urbanización, la transformación de la estructura agraria, el cambio climático y el extractivismo. Se constató que los estudios sobre este último factor han omitido la forma en que se produce el despoblamiento, en general en contextos de estructuras de poder desigual y de tensiones territoriales entre distintos modelos de desarrollo y de formas de habitar el espacio. Se propone el campo de la ecología política latinoamericana para abordar los procesos de despoblamiento rural vinculados al extractivismo, cuyos insumos teóricos pueden contribuir a la comprensión más amplia del problema y a la construcción de respuestas con y desde los propios territorios.

Resumo O objetivo deste artigo é realizar uma revisão documental sobre o despovoamento rural para localizar os principais antecedentes, correntes e visões de estudo na América Latina e outros espaços geográficos. A ênfase foi colocada no Chile para expor a forma como tem sido tratada a relação entre extrativismo e despovoamento rural, com a intenção de contrastar os resultados com os aportes teóricos da ecologia política latino-americana e propor uma análise abrangente desse fenômeno. Os resultados mostram que no Chile os fatores que historicamente impulsionam o despovoamento das áreas rurais têm sido a ditadura militar, os planos de ordenamento territorial, a industrialização e a urbanização, a transformação da estrutura agrária, as mudanças climáticas e o extrativismo. Constatou-se que os estudos sobre este último fator têm omitido a forma como ocorre o despovoamento, regularmente em contextos de estruturas de poder desiguais e tensões territoriais entre diferentes modelos de desenvolvimento e formas de habitar o espaço. O campo da ecologia política latino-americana se propõe a abordar os processos de despovoamento rural vinculados ao extrativismo, cujos aportes teóricos podem contribuir para uma compreensão mais ampla do problema e a construção de respostas com e a partir dos próprios territórios.

Abstract The goal was to conduct a documentary review on rural depopulation in order to identify the main antecedents, trends and visions in studies in Latin America and other geographical spaces. Emphasis was placed on Chile to expose the way in which the relationship between extractivism and rural depopulation has been treated, with the intention of contrasting the results with the theoretical inputs of Latin American political ecology and proposing a comprehensive analysis of this phenomenon. Results show that, in Chile, factors historically driving the depopulation of rural areas include the military dictatorship, the territorial ordering plans, industrialization and urbanization, the transformation of the agrarian structure, climate change and extractivism. It was found that studies on this last factor have omitted the way in which depopulation occurs, regularly in contexts of unequal power structures and territorial tensions between different development models and ways of inhabiting space. The field of Latin American political ecology is proposed in order to address the processes of rural depopulation linked to extractivism, since its theoretical inputs can contribute to a broader understanding of the problem and to the construction of responses with and from the territories themselves.

Supramolecular dynamic binary complexes with pH and salt-responsive properties for use in unconventional reservoirs.

Hydraulic fracturing of unconventional reservoirs has seen a boom in the last century, as a means to fulfill the growing energy demand in the world. The fracturing fluid used in the process plays a substantial role in determining the results. Hence, several research and development efforts have been geared towards developing more sustainable, efficient, and improved fracturing fluids. Herein, we present a dynamic binary complex (DBC) solution, with potential to be useful in the hydraulic fracturing domain. It has a supramolecular structure formed by the self-assembly of low molecular weight viscosifiers (LMWVs) oleic acid and diethylenetriamine into an elongated entangled network under alkaline conditions. With less than 2 wt% constituents dispersed in aqueous solution, a viscous gel that exhibits high viscosities even under shear was formed. Key features include responsiveness to pH and salinity, and a zero-shear viscosity that could be tuned by a factor of ~280 by changing the pH. Furthermore, its viscous properties were more pronounced in the presence of salt. Sand settling tests revealed its potential to hold up sand particles for extended periods of time. In conclusion, this DBC solution system has potential to be utilized as a smart salt-responsive, pH-switchable hydraulic fracturing fluid.

A administração no crepúsculo do reino: registros de Saint-Hilaire / Administración en el crepúsculo del reino: los registros de Saint-Hilaire / Administration in the twilight of the kingdom: Saint-Hilaire's records

Resumo O objetivo deste ensaio é analisar a estrutura e a operação da gestão pública no Reino Unido de Portugal, Brasil e Algarves, relacionadas à indústria extrativista de diamantes por meio das obras de Saint-Hilaire, botânico e naturalista francês, que visitou e percorreu o Brasil no século XIX, em viagem realizada em 1817. O autor descreveu aspectos ligados à estrutura organizacional, aos processos da operação de extração de diamantes, aos métodos de gestão pública, de recursos humanos, financeira e contratos no distrito dos diamantes. A análise de seus relatos revelou o alto grau de controle, bem como as condições de trabalho dos escravos e a rígida estratificação social do Brasil Império, com intensa utilização de mão de obra escrava, por meio do que se chamava à época de aluguel. Conclui-se que o autor fez extenso relato da operação, com inestimável contribuição para os estudos dos primórdios do Estado brasileiro.

Resumen El objetivo de este ensayo fue analizar la estructura y la operación de la gestión pública del Reino Unido de Portugal, Brasil y Algarves, relacionadas con la industria de extracción de diamantes a través de las obras de Saint-Hilaire, botánico y naturalista francés, que recorrió Brasil, en un viaje que realizado en 1817. El autor describió en detalles aspectos relacionados con la estructura organizacional, los procesos de la operación de extracción, los métodos de gestión pública, de recursos humanos, financiera y de contratos. El análisis de sus relatos reveló el alto grado de control, así como el uso intensivo del trabajo esclavo, a través de la subcontratación de recursos humanos, las condiciones de trabajo de los esclavos y la rígida estratificación social del reino. Se concluye que el autor presentó una detallada descripción de la operación lo que constituye una invaluable contribución a los estudios de los inicios del Estado brasileño.

Abstract This essay aims to analyze the structure and operation of the public management of the United Kingdom of Portugal, Brazil, and the Algarves, related to the diamond extraction industry through the texts of Saint-Hilaire, French botanist and naturalist. Saint-Hilaire visited and toured Brazil in 1817 in a journey throughout the country's interior offering detailed information on Brazil's organizational structure, operations management structure, the public management processes, and the management of human resources, finances, and contracts. The analysis of Saint-Hilaire's reports revealed a high degree of control, the slaves' work conditions, and the rigid social stratification of Brazil in the early 19th century. The essay concludes that Saint-Hilaire presented a deep and detailed description of the diamond extraction operation, offering a valuable contribution to the studies of the beginning of Brazil as an independent nation.

Preparation and properties of aflatoxins imprinted polymer grafted onto the surface of mesoporous silica SBA-15 functionalized with double bonds.

Mesoporous silica Santa Barbara-15 was functionalized by methacryloxypropyl trimethoxysilane. Taking this as the carrier material, a new mesoporous silica surface imprinted polymer was synthesized by using the C=C bond, functional monomer α-methacrylic acid, and crosslinker ethylene glycol dimethacrylate, which was used to extract aflatoxin from grain efficiently. It is different from the preparation of surface imprinted polymers which is physically wrapping carrier materials with polymer layers. The chemical grafting method makes the coating of the polymer layer more controllable. A new method for selective separation, enrichment, and determination of trace aflatoxin in grain was established by using the polymers as the filter of the solid-phase extraction column and high-performance liquid chromatography. The linear range of the method was 0.5-100 µg/kg, R2  = 0.9990-0.9993. The recovery of aflatoxin G2, G1, B2, and B1 was 98.9-119.7% and the relative standard deviation was 3.07-5.76%. By comparing the self-made column with the immunoaffinity column, it was found that the self-made column had better extraction performance for aflatoxins than the immunoaffinity column. It can be used for the analysis and detection of aflatoxins in cereal.

Single-crystal ordered macroporous metal-organic framework as support for molecularly imprinted polymers and their integration in membrane formant for the specific recognition of zearalenone.

Zearalenone is a fungal contaminant that is widely present in grains. Here, a novel molecularly imprinted membrane based on SOM-ZIF-8 was developed for the rapid and highly selective identification of zearalenone in grain samples. The molecularly imprinted membrane was prepared using polyvinylidene fluoride, cyclododecyl 2,4-dihydroxybenzoate as a template and SOM-ZIF-8 as a carrier. The factors influencing the extraction of zearalenone using this membrane, including the solution pH, extraction time, elution solvent, elution time, and elution volume, were studied in detail. The optimized conditions were 5 mL of sample solution at pH 6, extraction time of 45 min, 4 mL of acetonitrile:methanol = 9:1 as elution solvent, and elution time of 20 min. This method displayed a good linear range of 12-120 ng/g (R2  = 0.998) with the limits of detection and quantification of this method are 1.7 and 5.5 ng/g, respectively. In addition, the membrane was used to selectively identify zearalenone in grain samples with percent recoveries ranging from 87.9 to 101.0% and relative standard deviation of less than 6.6%. Overall, this study presents a simple and effective chromatographic pretreatment method for detecting zearalenone in food samples.

LSTM-based approach for predicting periodic motions of an impacting system via transient dynamics.

Dynamically impacting systems are characterised with inherent instability and complex non-linear phenomena which makes it practically difficult to predict the steady state response of the system at transient periods. This study investigates the ability of a data driven machine learning method using Long Short-Term Memory networks to learn the complex nonlinearity associated with co-existing impact responses from limited transient data. A one-degree-of-freedom impact oscillator has been used to represent the bit-rock interaction for percussive drilling. Simulated data results show velocity measurements to contribute most to predicting steady state responses from transient dynamics with most of the network models reaching an accuracy of over 95%. Limitations to practically measurable variables in dynamic systems warranted the development of a feature based network model for impact motion classification. Experimental data from a two-degrees-of-freedom impacting system representing percussive bit penetration has been used to demonstrate the effectiveness of this method. The study thus provides a precise and less computational means of detecting and avoiding underperforming impact modes in percussive drilling.

Protocolo de bioseguridad frente al COVID-19 para actividades del sector minero / Biosafety protocol against COVID-19 for activities in the mining sector

Establecer los lineamientos y procedimientos de bioseguridad y salud en el marco de la prevención del contagio, atención y seguimiento de casos sospechosos y casos de contactos con pacientes COVID-19 para el Sector Minero.

Characteristics of heavy metals in size-fractionated atmospheric particulate matters and associated health risk assessment based on the respiratory deposition.

The heavy metal distributions in size-fractionated atmospheric particulate matters and the associated health risks were investigated in a typical mining and smelting area in Southwest China. The Cd, Cr, Cu, Pb, and Zn concentrations were 19.28, 44.48, 100.0, 554.0, and 601.8 ng/m3, respectively, in PM2.1; and 23.45, 60.99, 95.25, 559.3, and 813.7 ng/m3, respectively, in PM10. Enrichment factors of heavy metals indicated that anthropogenic sources of Cd, Cu, Pb, and Zn in the size-fractionated particles. The elevated concentrations of Cd, Cu, Pb, and Zn were dominantly enriched in submicron particles (DP < 1.1 µm), whereas Cr tended to be accumulated in coarse particles (2.1 < DP < 10 µm). The deposition concentrations for multiple heavy metals in the head airway region, tracheobronchial region, and alveolar regions were 321.07, 21.58, and 51.96 ng/h for children, and 634.49, 42.65, and 102.68 ng/h for adults, respectively. The coarse particles contributed the most to the deposition concentration of HMs in head region, whereas submicron particles had relative higher proportions in the alveolar region. Heavy metals, especially Pb, caused noncarcinogenic risk to the children as the hazard index was 4.45. Moreover, total carcinogenic risks of heavy metals (Cr, Cd, and Pb) were 4.33 × 10-5 and 7.58 × 10-5 for adults and children, respectively, indicating potential carcinogenic risks. Overall, the results of this study revealed high health risks to the residents living around the mining and smelting areas, especially the children. It was therefore urgent to control the emission of heavy metals in the atmosphere.