163 research outputs found
Analysis of a Sorter Cascade Applied to Control a Wheelchair
The precise eye state detection is a fundamental stage for various activities that require human-machine interaction (HMI). This chapter presents an analysis of the implementation of a system for navigating a wheelchair with automation (CRA), based on facial expressions, especially eyes closed using a Haar cascade classifier (HCC). Aimed at people with locomotor disability of the upper and lower limbs, the state detection was based on two steps: the capture of the image, which concentrates on the detection actions and image optimization; actions of the chair, which interprets the data capture and sends the action to the chair. The results showed that the model has excellent accuracy in identification with robust performance in recognizing eyes closed, bypassing well occlusion issues and lighting with about 98% accuracy. The application of the model in the simulations opens the implementation and marriage opportunity with the chair sensor universe aiming a safe and efficient navigation to the user
Spatiotemporal assessment of particulate matter (PM10 and PM2.5) and ozone in a Caribbean urban coastal city
Air pollution has become a critical issue in urban areas, so a broad understanding of its spatiotemporal characteristics is important to develop public policies. This study analyzes the spatiotemporal variation of atmospheric particulate matter (PM10 and PM2.5) and ozone (O3) in Barranquilla, Colombia from March 2018 to June 2019 in three monitoring stations. The average concentrations observed for the Móvil, Policía, and Tres Avemarías stations, respectively, for PM10: 46.4, 51.4, and 39.7 μg/m3; for PM2.5: 16.1, 18.1, and 15.1 μg/m3 and for O3: 35.0, 26.6, and 33.6 μg/m3. The results indicated spatial and temporal variations between the stations and the pollutants evaluated. The highest PM concentrations were observed in the southern part of the city, while for ozone, higher concentrations were observed in the north. These variations are mainly associated with the influence of local sources in the environment of each site evaluated as well as the meteorological conditions and transport patterns of the study area. This study also verified the existence of differences in the concentrations of the studied pollutants between the dry and rainy seasons and the contribution of local sources as biomass burnings from the Isla Salamanca Natural Park and long-range transport of dust particles from the Sahara Desert. This study provides a scientific baseline for understanding air quality in the city, which enables policy makers to adopt efficient measures that jointly prevent and control pollution
Dispersion of hazardous nanoparticles on beaches around phosphogypsum factories
Anthropogenic occurring nanoparticles (NPs) have been one of the principal catalytic components of marine pollution throughout its history. The phosphogypsum (PG) factories present environmental risks and evident marine pollution in different parts of the world. Many of these factors continue to operate, however, some have already been abandoned by the private sector. The general objective of this manuscript is to analyze the real nanoparticles (NPs) present on a beach in southern Brazil to illustrate the need to create public policies and projects for environmental recovery. This work focused on real representative sampling of suspended sediments (SSs), and on a modern analytical procedure via advanced electron microscopes (field emission scanning electron microscope-FE-SEM and high resolution transmission electron microscope-HR-TEM coupled with an energy dispersive X-ray microanalysis system-EDS) to analyze NPs containing hazardous elements (HEs). The results presented in this work demonstrate who the size, morphology, among other physical-geochemical characteristics influence in the adsorption of HEs by the NPs and their respective agglomerates. This study is of great importance for carrying out the application of advanced techniques and methods to better understand the formation and transport of NPs on beaches, which allows assisting in the management of waste from plaster factories on a global scale
STENOSTOMUM LEUCOPS DUGÈS, 1828 (PLATYHELMINTHES, CATENULIDA): A PUTATIVE SPECIES COMPLEX WITH PHENOTYPIC PLASTICITY
RESUMO Stenostomum são pequenos vermes que vivem em água doce e normalmente se reproduzem assexualmente por paratomia. Eles estão na base da filogenia dos platelmintes. Por mais de um século, espécies desse gênero, especialmente S. leucops, vêm sendo empregadas em estudos biológicos, principalmente sobre regeneração. Entretanto, alguns aspectos básicos da biologia destes vermes são ainda pobremente conhecidos. Neste estudo, caracterizamos uma linhagem que vem sendo mantida no laboratório por cinco anos. O tempo necessário para reprodução assexuada e completa formação de zoóides, a 28°C, é de aproximadamente 42,5 horas. O número de células nos zoóides, logo após a paratomia, é de aproximadamente 2.500. O número de zoóides presentes nos vermes é uma característica variável e depende das condições de cultivo. Em alguns procedimentos de cultivo de S. leucops, apenas cadeias com dois zoóides são formadas. No entanto, em outras condições de cultivo, cadeias de até cinco zoóides podem ser observadas. Análise filogenética empregando sequência do gene de Citocromo C Oxidase (COI) mostrou que S. leucops e S. grande constituem um complexo de espécies cujas linhagens mostram altas divergências intraespecíficas.ABSTRACT Species of Stenostomum are small flatworms that live in freshwater and normally reproduce asexually by paratomy. They are basal in the phylogeny of Platyhelminthes. For more than a century, species of this genus, especially S. leucops, have been used in regeneration and other biological studies. However, some basic aspects of their biology are poorly known. Here, we characterized a strain of S. leucops that has been maintained in the laboratory for five years and a recent strain of S. grande. The time required for complete formation of zooids of S. leucops by asexual reproduction is approximately 42.5 hours at 28°C. The number of cells in the zooids, soon after paratomy, is approximately 2,500. The number of zooids formed in the chain is a plastic characteristic and is dependent on the conditions for cultivation. In some cultivation conditions of S. leucops, only worms with two zooids are formed. However, in other conditions, worms with up to five zooids are observed. Phylogenetic analyses of a fragment of the Cytochrome C Oxidase I (COI) sequence showed S. leucops and S. grande species constitute a species complex, the lineages of which having high intraspecific divergences
STENOSTOMUM LEUCOPS DUGÈS, 1828 (PLATYHELMINTHES, CATENULIDA): A PUTATIVE SPECIES COMPLEX WITH PHENOTYPIC PLASTICITY
RESUMO Stenostomum são pequenos vermes que vivem em água doce e normalmente se reproduzem assexualmente por paratomia. Eles estão na base da filogenia dos platelmintes. Por mais de um século, espécies desse gênero, especialmente S. leucops, vêm sendo empregadas em estudos biológicos, principalmente sobre regeneração. Entretanto, alguns aspectos básicos da biologia destes vermes são ainda pobremente conhecidos. Neste estudo, caracterizamos uma linhagem que vem sendo mantida no laboratório por cinco anos. O tempo necessário para reprodução assexuada e completa formação de zoóides, a 28°C, é de aproximadamente 42,5 horas. O número de células nos zoóides, logo após a paratomia, é de aproximadamente 2.500. O número de zoóides presentes nos vermes é uma característica variável e depende das condições de cultivo. Em alguns procedimentos de cultivo de S. leucops, apenas cadeias com dois zoóides são formadas. No entanto, em outras condições de cultivo, cadeias de até cinco zoóides podem ser observadas. Análise filogenética empregando sequência do gene de Citocromo C Oxidase (COI) mostrou que S. leucops e S. grande constituem um complexo de espécies cujas linhagens mostram altas divergências intraespecíficas.ABSTRACT Species of Stenostomum are small flatworms that live in freshwater and normally reproduce asexually by paratomy. They are basal in the phylogeny of Platyhelminthes. For more than a century, species of this genus, especially S. leucops, have been used in regeneration and other biological studies. However, some basic aspects of their biology are poorly known. Here, we characterized a strain of S. leucops that has been maintained in the laboratory for five years and a recent strain of S. grande. The time required for complete formation of zooids of S. leucops by asexual reproduction is approximately 42.5 hours at 28°C. The number of cells in the zooids, soon after paratomy, is approximately 2,500. The number of zooids formed in the chain is a plastic characteristic and is dependent on the conditions for cultivation. In some cultivation conditions of S. leucops, only worms with two zooids are formed. However, in other conditions, worms with up to five zooids are observed. Phylogenetic analyses of a fragment of the Cytochrome C Oxidase I (COI) sequence showed S. leucops and S. grande species constitute a species complex, the lineages of which having high intraspecific divergences
Chemical composition and minerals in pyrite ash of an abandoned sulphuric acid production plant
The extraction of sulphur produces a hematite-rich waste, known as roasted pyrite ash, which contains significant amounts of environmentally sensitive elements in variable concentrations and modes of occurrence. Whilst the mineralogy of roasted pyrite ash associated with iron or copper mining has been studied, as this is the main source of sulphur worldwide, the mineralogy, and more importantly, the characterization of submicron, ultrafine and nanoparticles, in coal-derived roasted pyrite ash remain to be resolved. In this work we provide essential data on the chemical composition and nanomineralogical assemblage of roasted pyrite ash. XRD, HR-TEM and FE-SEM were used to identify a large variety of minerals of anthropogenic origin. These phases result from highly complex chemical reactions occurring during the processing of coal pyrite of southern Brazil for sulphur extraction and further manufacture of sulphuric acid. Iron-rich submicron, ultrafine and nanoparticles within the ash may contain high proportions of toxic elements such as As, Se, U, among others. A number of elements, such as As, Cr, Cu, Co, La, Mn, Ni, Pb, Sb, Se, Sr, Ti, Zn, and Zr, were found to be present in individual nanoparticles and submicron, ultrafine and nanominerals (e.g. oxides, sulphates, clays) in concentrations of up to 5%. The study of nanominerals in roasted pyrite ash from coal rejects is important to develop an understanding on the nature of this by-product, and to assess the interaction between emitted nanominerals, ultra-fine particles, and atmospheric gases, rain or body fluids, and thus to evaluate the environmental and health impacts of pyrite ash materials
An overview of geological originated materials as a trend for adsorption in wastewater treatment
Adsorption is a unit operation widely used for the tertiary treatment of the most diverse effluents, whose mechanism is based on removing recalcitrant compounds from the organic and inorganic origin. In this process, choosing a suitable adsorbent is a fundamental point. This review article focuses on the adsorbents with natural geological origin: minerals, clays, geopolymers, and even wastes resulted from mining activity. Therefore, over 450 articles and research papers were explored. These materials' main sources are described, and their characteristics, composition, and intrinsic properties are related to adsorption. Herein, we discuss the effects of several process parameters, such as pH, temperature, pollutant, and adsorbent concentration. Furthermore, equilibrium, kinetics, and thermodynamic aspects are also addressed, and relevant regeneration prospects and final disposal. Finally, some suggestions and perspectives on applying these adsorbents in wastewater treatment are presented as future trends
Nanoparticles from construction wastes: A problem to health and the environment
The present study deals with the nano-mineralogy and geochemistry of ultrafine particles in construction waste from the Porto Alegre region in Southern Brazil. Uncontrolled construction waste dumps and
poor management practices in formal disposal sites in the area may increase exposure risks to population. Whilst the physicochemical properties of construction wastes are well documented in the literature, the characteristics of nanoparticles in their formulations are not well known. Given that
degradation of construction materials may unlock and enable further release of nano-particulates present, we focused on the <63 mm fraction to examine the geochemistry of inhalable nano-particulates that
could cause adverse health impacts on local communities. A particular feature across the studied wastes
are the numerous aerodynamically favourable, spherical-shaped nanoparticles of magnetite, rutile and
anatase. The detected nanoparticles contained a number of elements including Al, As, Au, Ca, Cd, Co, Cr,
Cu, Hg, Na, Fe, K, S, Sn, Si and. An enrichment in metals and metalloids such as As, Co, Cr, Cu, Hg, Fe, Sn or
Ta in particles in the nano-scale range in relation to larger particles was observed. The presence of carbon
nanotubes was also noted. The leaching tests showed that the construction wastes did not reach the
limits for their disposal as hazardous waste according the European Directive. Whilst the majority of
trace elements were highly immobile, the water extractability for oxyanionic-forming metalloids suggests possible migration to surface and groundwater bodies. This work seeks to bring awareness on the
impacts of unsustainable construction waste management, and the relevance of improved regulations
regarding their final disposal
Estimation of the impact of biomass burning based on regional transport of PM2.5 in the Colombian Caribbean
Deterioration of air quality due to the increase in atmospheric emissions from biomass burning (BB) is one of the major environmental problems worldwide. In this study, we estimated the contributions of BB to PM2.5 concentrations in the municipalities of Soledad and Malambo located in the Colombian Caribbean. The evaluation period ranged from February 24 to March 30, 2018, a period with a high number of BB events recorded in the surroundings of the evaluated sites. The contribution of BB to the two sampling sites was estimated using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) dispersion model with forwarding trajectories from each of the burning points identified by satellite images (n = 1089). The PM2.5 emissions were determined using the fire radiative power (FRP), obtained by remote-sensing data, and corresponded to the radiant energy released per time unit by burning vegetation. The average PM2.5 concentrations during the evaluation period were 19.91 μg/m3 for Soledad and 22.44 μg/m3 for Malambo. The average contribution of BB to these municipalities was 22.8% and 28.8%, respectively. The methodology used in this study allowed to estimate the contribution of this important source without knowledge of a previous tracer of BB, thereby increasing the use of the proposed procedure worldwide. This information would enable the implementation of effective mitigation, thereby diminishing the adverse impact of PM2.5 on the health of the population
Air pollutants and their degradation of a historic building in the largest metropolitan area in latin america
Historic buildings that comprise the cultural heritage of humanity are in need of preservation on a worldwide scale in regard to degradation resultant from atmospheric pollutants. The Brazilian Public Market, located in the historic center of the mega city of Sao Paulo, is the object of this research, due to its representation of historical Brazilian architecture. The general objective of this manuscript is to analyze the influence of air pollutants on the degradation of the historic Sao Paulo Public Market in the city of Sao~ Paulo, Brazil. Methodologically, between May 2018 and April 2019, samples of sedimented dust were collected at five points on the side walls of the market’s historic structure, for the analysis of accumulated ultrafine particles (UFPs) and nanoparticles (NPs). A total of 20 samples of particulate matter were collected using self-made passive samplers (SMPSs). Using SMPSs, 12 months of accumulation and deposition were used to sample the atmospheric PM1. The results demonstrate the presence of dangerous elements such as: As, Cd, Cr, Pb, Zn. Note that EDS coupled with microscopy techniques, points out the risks to human health, due to the presence of these dangerous elements that accumulate in the building’s structure. The results show that 85% of the NPs sampled contained Pb, and 56% contained Pb and Ti, which are harmful to both historic buildings and human health. Air pollution enables the further deterioration of the Sao Paulo Public Market, which is in need of restoration
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