The use of particle-induced X-ray emission (PIXE) technique in the biomonitoring of catarinense coal basin ecosystems: a review

2018 ◽  
Vol 28 (01n02) ◽  
pp. 51-59
Author(s):  
Jairo José Zocche ◽  
Vanessa Moraes de Andrade ◽  
Ricardo Aurino Pinho ◽  
Johnny Ferraz Dias

Brazilian coal residues contain high sulfide levels and several environmentally relevant metals and metalloids. Herein, we present a review about the use of the particle-induced X-ray emission (PIXE) technique in the analysis of chemical elements content in the biotic and abiotic compartments of Catarinense Coal Basin (CCB). The content of P, K, Ca, Fe and Zn in the soil and vegetables from coal-mining areas were found to be higher than those in the reference area. The same patterns were observed in frogs relative to the contents of P, S, K, Mn, Fe, Cu and Zn; to bats concerning the contents of P, S and Fe; and to mice fed with juice of vegetables from coal mining-areas, regarding the contents of P, K, Fe, Cu and Zn. The results suggest a possible contamination of the wild species that inhabit the coal-mined areas and that people consuming food from coal-mining areas may ingest significant amounts of chemical elements that pose a risk to health, since they contain both essential and toxic elements in a wide range of concentrations, which can do more harm than good.

2021 ◽  
Author(s):  
Vivek Kumar ◽  
Dibyendu Paul ◽  
Sudhir Kumar

<p>Meghalaya, also known as ‘abode of clouds’, is a state located in north-eastern part of India, blessed with abundance of water resources. In the last few decades, extensive coal mining in different parts of Meghalaya has caused detrimental changes in the environment, particularly the aquatic systems. Acid and metal loaded effluents (also known as acid mine drainage or AMD), resulting from the exposure of sulphide mineralization to oxidizing conditions from abandoned or active mining areas, are the principal environmental problems today. Sulphate (SO<sub>4</sub><sup>2-</sup>) is a major contaminant and attracts widespread attention as the dominant form of sulphur in coal mining affected aquatic systems. The increased presence of SO<sub>4</sub><sup>2- </sup>in ecosystems affected by mining activities has immense negative environmental and human health effects. Low pH and high heavy metal concentrations have been reported from streams flowing in and around the coal mining area in Meghalaya rendering the water quality to be very poor  and unfit for use as potable water.</p><p>Stable isotopes have emerged as a promising environmental tracer to understand different environmental functions and processes. Valuable information on the sources and processes can be obtained from the stable isotope ratios of chemical elements in environmental samples as the sources and processes influence history of the samples. Stable isotopes analysis combined with hydrochemical analysis enhances our understanding of transformation and environmental fate of different compounds in water bodies and can provide precise information about factors responsible for controlling water chemistry of different water bodies.</p><p>Stable isotopes of sulphur and oxygen combined with hydrochemical parameters were used as a tool for determining origin, transformation and fate of sulphur in AMD affected water bodies in Meghalaya.The study was conducted on two rivers affected by AMD, viz. Myntdu River and Lunar-Lukha River, flowing in the Jaintia Hills region of Meghalaya. The water samples collected are analysed for hydrochemical parameters and stable sulphur and oxygen isotopes (δ<sup>34</sup>S and δ<sup>18</sup>O in aqueous SO<sub>4</sub><sup>2-</sup>). The stable isotopes of sulphur and oxygen were also analysed in the coal samples from the nearby mining areas. The result provided an insight into the transformational processes of sulphur in these two AMD affected rivers and the environmental fate of sulphur.</p>


2016 ◽  
Vol 71 (5) ◽  
pp. 1060-1068 ◽  
Author(s):  
Frank H. Chung

For research and development or for solving technical problems, we often need to know the chemical composition of an unknown mixture, which is coded and stored in the signals of its X-ray fluorescence (XRF) and X-ray diffraction (XRD). X-ray fluorescence gives chemical elements, whereas XRD gives chemical compounds. The major problem in XRF and XRD analyses is the complex matrix effect. The conventional technique to deal with the matrix effect is to construct empirical calibration lines with standards for each element or compound sought, which is tedious and time-consuming. A unified theory of quantitative XRF analysis is presented here. The idea is to cancel the matrix effect mathematically. It turns out that the decoding equation for quantitative XRF analysis is identical to that for quantitative XRD analysis although the physics of XRD and XRF are fundamentally different. The XRD work has been published and practiced worldwide. The unified theory derives a new intensity–concentration equation of XRF, which is free from the matrix effect and valid for a wide range of concentrations. The linear decoding equation establishes a constant slope for each element sought, hence eliminating the work on calibration lines. The simple linear decoding equation has been verified by 18 experiments.


2010 ◽  
Vol 110 (7) ◽  
pp. 684-691 ◽  
Author(s):  
Jairo José Zocche ◽  
Daniela Dimer Leffa ◽  
Adriani Paganini Damiani ◽  
Fernando Carvalho ◽  
Rodrigo Ávila Mendonça ◽  
...  

Author(s):  
V. V. Karabyn

The essence of subsidence and flooding of the territories was exa­mined. Using the route observation method, the phenomenon of subsidence and flooding within the Chervonohrad industrial mining region of the Lviv-Volyn coal basin was evaluated. The obtained results were compared with the data of geodetic monitoring and aerial photographs decoding. The intensity of subsidence and flooding of the surface was compared with the natural and technogenic factors. The classification of factors of subsidence and flooding of the coal mining area within the Chervonohrad industrial mining region of the Lviv-Volyn coal basin was carried out. Geological, climatic, and landscape factors were distinguished and grouped together as natural factors, while mining and residential factors were combined into a technogenic group. The selection of each factor is justified by the results of field and experimental explorations within the area of research. Relationships between factors of subsidence and flooding were established.


Author(s):  
Judith M. Brock ◽  
Max T. Otten

A knowledge of the distribution of chemical elements in a specimen is often highly useful. In materials science specimens features such as grain boundaries and precipitates generally force a certain order on mental distribution, so that a single profile away from the boundary or precipitate gives a full description of all relevant data. No such simplicity can be assumed in life science specimens, where elements can occur various combinations and in different concentrations in tissue. In the latter case a two-dimensional elemental-distribution image is required to describe the material adequately. X-ray mapping provides such of the distribution of elements.The big disadvantage of x-ray mapping hitherto has been one requirement: the transmission electron microscope must have the scanning function. In cases where the STEM functionality – to record scanning images using a variety of STEM detectors – is not used, but only x-ray mapping is intended, a significant investment must still be made in the scanning system: electronics that drive the beam, detectors for generating the scanning images, and monitors for displaying and recording the images.


2012 ◽  
Vol 57 (4) ◽  
pp. 1045-1055
Author(s):  
Pavel Zapletal ◽  
Pavel Prokop ◽  
Vítězslav Košňovský

Abstract The main subject of this paper focuses on scientific and research activities conducted in the Institute of Mining Engineering and Safety of the VŠB-Technical University of Ostrava. Cooperation between the VŠB-Technical University of Ostrava and OKD A.S., the only representative of coal mining in the Ostrava-Karviná coal basin, has recently begun to develop again. This paper describes an example discussed in a certain study, which has been undertaken for the Paskov mine, OKD a.s., dealing specifically with the evolution of microclimate parameters in mines that depend on the progress of mining activity at deeper levels over a period of several years. To this end, a special program, aimed at determination of the necessary refrigerating capacity, was established at the VŠB-Technical University of Ostrava.


Author(s):  
Christian Devereux ◽  
Justin Smith ◽  
Kate Davis ◽  
Kipton Barros ◽  
Roman Zubatyuk ◽  
...  

<p>Machine learning (ML) methods have become powerful, predictive tools in a wide range of applications, such as facial recognition and autonomous vehicles. In the sciences, computational chemists and physicists have been using ML for the prediction of physical phenomena, such as atomistic potential energy surfaces and reaction pathways. Transferable ML potentials, such as ANI-1x, have been developed with the goal of accurately simulating organic molecules containing the chemical elements H, C, N, and O. Here we provide an extension of the ANI-1x model. The new model, dubbed ANI-2x, is trained to three additional chemical elements: S, F, and Cl. Additionally, ANI-2x underwent torsional refinement training to better predict molecular torsion profiles. These new features open a wide range of new applications within organic chemistry and drug development. These seven elements (H, C, N, O, F, Cl, S) make up ~90% of drug like molecules. To show that these additions do not sacrifice accuracy, we have tested this model across a range of organic molecules and applications, including the COMP6 benchmark, dihedral rotations, conformer scoring, and non-bonded interactions. ANI-2x is shown to accurately predict molecular energies compared to DFT with a ~10<sup>6</sup> factor speedup and a negligible slowdown compared to ANI-1x. The resulting model is a valuable tool for drug development that can potentially replace both quantum calculations and classical force fields for myriad applications.</p>


Author(s):  
Katherine V. Whittington

Abstract The electronics supply chain is being increasingly infiltrated by non-authentic, counterfeit electronic parts, whose use poses a great risk to the integrity and quality of critical hardware. There is a wide range of counterfeit parts such as leads and body molds. The failure analyst has many tools that can be used to investigate counterfeit parts. The key is to follow an investigative path that makes sense for each scenario. External visual inspection is called for whenever the source of supply is questionable. Other methods include use of solvents, 3D measurement, X-ray fluorescence, C-mode scanning acoustic microscopy, thermal cycle testing, burn-in technique, and electrical testing. Awareness, vigilance, and effective investigations are the best defense against the threat of counterfeit parts.


Sign in / Sign up

Export Citation Format

Share Document