Erratum: Martins, M.S., et al. Wideband and wIde beam polyvinylidene difluoride (PVDF) acoustic transducer for broadband underwater. Sensors 2019, 19, 3991

The authors wish to make the following erratum to this paper [...].info:eu-repo/semantics/publishedVersio

Nanoparticles and interfaces with toxic elements in fluvial suspended sediment

Studies examining nanoparticles (NPs) and hazardous elements (HEs) contained in suspended sediments (SSs) are vital for watershed administration and ecological impact evaluation. The biochemical consequence of titanium-nanoparticles (Ti-NPs) from SSs in Colombia's Magdalena River was examined utilizing an innovative approach involving nanogeochemistry in this study. In general, the toxicity and the human health risk assessment associated with the presence of some Ti-NPs + HEs in SSs from riverine systems need to be determined with a robust analytical procedure. The mode of occurrence of Ti-NPs, total Ti and other elements contained within SSs of the Magdalena River were evaluated through advanced electron microscopy (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); X-Ray Diffractions (XRD); and inductively coupled plasma-mass spectrometry (ICP-MS). This work showed that enormous quantities of Ti-NPs were present in the river studied and that they displayed diverse geochemical properties and posed various possible ecological dangers. Ti-NP contamination indices must be established for measuring the environmental magnitudes of NP contamination and determining contamination rank among rivers. Finally, SS contamination guidelines must be recommended on an international level. This study contributes to the scientific understanding of the relationship of HE and Ti-NP dynamics from SSs in riverine systems around the world

Application Of Optical Method In Measuring Mechanical Vibrations In A Cantilever Beam

The pertinent literature discloses a family of optical profile measuring techniques highlighting the moire methods. The Moire technique is based on the interference of two superimposed optical grids which produce fringe patterns which can be processed to analyze the DYNAMIC MEASUREMENT IN MATERIALS mechanical behavior. The goal of this research is to experimentally determine the mechanical displacement of a slim cantilever beam by means of Moire technique with Phase Shift. Photomechanical experimental arrangement included a digital camera, a multimedia projector and a PC. The occurrence of oscillations has been adequately analyzed. The results showed data from which useful information can withdraw, being of great importance to support agricultural machinery projects and development.371849

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

Nanoparticles as vectors of other contaminants in estuarine suspended sediments: Natural and real conditions

Studding the behaviour and danger of nanoparticles (NPs, minerals and amorphous phases) in the estuarine ecosystem is presently incomplete by the lack of measureable description of NPs in the ecological conditions, such as suspended-sediments (SS). In the last years, several works have revealed the toxic consequences of ultra-fine and nanoparticulate compounds on diverse systems, raising apprehensions over the nanocontaminants behaviour and destiny in the numerous ecological partitions. The general objective of the manuscript is to explain the geochemical conditions of the LES (Laguna estuarine system, southern Brazil) suspended sediments covering an area around the main South American coal plant, enhancing the creation of future public policies for environmental recovery projects. Subsequently the discharge of nanoparticles and toxic element (TE) in the ecosystem, NPs react with several constituents of the nature and suffers active alteration progressions. Contamination coming from engineering actions, wastewater, are something identifiable, however when these contaminations are accompanied by other contamination sources (e.g. mining and farming) the work gets defaulted. By combining material about the concentration of TE contaminants and NPs occurrences, this work offers novel visions into contaminant contact and the possible effects of such exposure on estuarine systems in Brazil. The results presented here will be useful for different areas of estuaries around the world

Environmental aspects of the depreciation of the culturally significant Wall of Cartagena de Indias – Colombia

Among the diverse archeological relics of the past, the Cartagena de Indias Wall is one of the greatest representations of European cultural architecture in South America. To assess the implication of contamination on the depreciation of the culturally significant Wall of Cartagena de Indias - Colombia, a detailed, multi-analytical approach was conducted on components of the wall. Accumulated ultra-fine particles (UFPs) and superficial nano-particles (NPs) containing hazardous elements (HEs) on the wall were identified in an attempt to understand whether atmospheric pollution is hastening the depreciation of the structure itself. Mortar which at one point held the stones together is now weak and has fallen away in places. Irreparable damage is being done by salt spray, acid rain and the site's tropical humid climate. Several HEs and organic compounds found within the local environment are also contributing to the gradual deterioration of the construction. In this study, advanced microscopy analyses have been applied to understand the properties of UFPs and NPs deposited onto the wall's weathered external walls through exposure to atmospheric pollution. Several materials identified by X-Ray Diffraction (XRD) can be detected using high-resolution transmission electron microscopy (HR-TEM) and field emission scanning electron microscope (FE-SEM). The presence of anglesite, gypsum, hematite containing HEs, and several organic compounds modified due to moisture and contamination was found. Black crusts located on the structure could potentially serve as a source of HEs pollution and a probable hazard to not only to the ecosystem but also to human health

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