scholarly journals SOME PROTECTIONS ON THE ROLE OF GEOCHEMICAL PROPERTIES OF CHEMICAL ELEMENTS IN THE PROBLEMS OF ENVIRONMENTAL POLLUTION AND PROTECTION

2021 ◽  
Vol 07 (03) ◽  
pp. 31-34
Author(s):  
Intizar Aliyeva Intizar Aliyeva ◽  
Rasul Hajıyev Rasul Hajıyev
Keyword(s):  
Spectral Analysis ◽  
Negative Impact ◽  
Chemical Elements ◽  
Low Cost ◽  
High Sensitivity ◽  
X Ray ◽  
Geochemical Properties ◽  
Geochemical Parameters ◽  
Industrial Complexes

The article discusses various limited considerations and assumptions on the positive or negative impact of geochemical features chemical elements found in rocks, ores, soil, plants, water and in the air of the territories of populated areas, factories, the mining and agro-industrial complexes to the environment and the role of analytical geochemistry in this process. According to the author, one of the main points on which the light should be shed is the role of finding elements (independent, combination or isomorphic mixture) rather than their existence in different amounts in the environment. Thus, the chemical elements can be more or less hazardous to environment regardless its amount, but the finding methods. Chemical and natural combinations can be either very hazardous or very useful to all living creatures depending on their characteristics, so it’s better to determine their environmental hazardousness via their impact to a particular human or animal organ which in turn facilitates the solution of the problem. Moreover, it should be noted that the most environmentally dangerous and active chemical elements are the ones with fluctuating valence. Some elements are not so hazardous when they are independent or in solid form since they change weakly. But they are very dangerous when they turn into liquid or gas forms and create mineral compounds with other elements such as halkofil group of elements which in turn can easily decompose and dissolve in water by causing dangers to all living creatures in the nature. Approximately any chemical element can either react negatively or in most cases stimulate the life functions of the organs of animals and plants depending on its finding forms. The study of geochemical parameters in different natural objects such as surface and subsoil water, air, rocks and ores can be very helpful in organizing the protection of environmetal and the solution of its problems. X-ray Spectral analysis is particularly highlighted in this article for identifying various chemical elements in geological and ecological objects. There are several advantages of X-ray Spectral analysis such as its productiveness and low cost, the expressiveness and simplicity of analysis operations, having slightly high sensitivity, universality, high range of elements identification features, etc. To conclude some authors claim that the following problems can be solved with the help of analytic geochemistry: Identifying the main source of pollution and the evaluation of its impact on the environment; Identification of quantitative and qualitative parameters of sources of natural, techno and agro genic pollution in the settlements, industrial objects and in the regions of developed mining complexes; Eco-geochemical and biochemical evaluation of the negative impact of water, weather and harmful geochemical anomalies on live organisms. We hope the elimination of this type of problems can pave the way to the ecologically clean environment. Keywords: ore, soil, plant, water, weather.

scholarly journals FEATURES OF DENTINE CHEMICAL COMPOSITION OF INTACT TEETH AND TEETH WITH WEDGE-SHAPED DEFECTS

2021 ◽  
Vol 74 (8) ◽  
pp. 1869-1875
Author(s):  
Svitlana P. Yarova ◽  
Iryna I. Zabolotna ◽  
Olena S. Genzytska ◽  
Andrii A. Komlev
Keyword(s):  
Chemical Composition ◽  
Chemical Elements ◽  
Cervical Region ◽  
Cervical Lesions ◽  
X Ray ◽  
Sodium Magnesium ◽  
Calcium Phosphorus ◽  
Cervical Area ◽  
Focused Beam

The aim: Is to define dentine chemical composition of intact teeth and those with wedge-shaped defects followed by the analysis of revealed differences. Materials and methods: Longitudinal sections of 22 clinically removed teeth (12 – clinically intact ones, 10 – with wedge-shaped defects) from both jaws were studied in patients aged between 25-54 years. JSM-6490 LV focused beam electron microscope (scanning) with system of energy-dispersive X-ray microanalysis INCA Penta FETх3 was used. The chemical composition of 148 dentine areas in the incisal region (tubercle), equator, cervical area has been determined as a percentage of the weight amounts of carbon, oxygen, calcium, phosphorus, sodium, magnesium, sulfur, chlorine, zinc, potassium, aluminum. Results: Dentine chemical composition of teeth with wedge-shaped defects differed from those of intact teeth by significantly lower content: sodium, chlorine and calcium – in the incisal region (tubercle); sodium, magnesium − at the equator; sodium, chlorine and calcium – in the cervical region (p≤0.05). In the sample groups with cervical pathology there was more sulfur and oxygen in the incisal region (tubercle), phosphorus and zinc – at the equator, carbon and potassium – in the cervical region (p≤0.05). Conclusions: Differences in the chemical composition of intact teeth and teeth with wedge-shaped defects, the presence of correlation between the studied chemical elements confirm the role of macro- and microelements in the pathogenesis of non-carious cervical lesions.

Aluminium Induced Crystallization of Amorphous Silicon via Solution Derived Catalyst

2013 ◽  
Vol 481 ◽  
pp. 3-6
Author(s):  
Ian Yi Yu Bu
Keyword(s):  
Annealing Temperature ◽  
Preparation Method ◽  
Low Cost ◽  
Vacuum Solution ◽  
Solution Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Induced Crystallization ◽  
Probe Measurements

In this paper, aluminum induced crystallization (AIC) was studied by examining the effect of using solution derived AlCl3 catalyst. Such catalyst preparation method offers possibility of low-cost, non-vacuum solution process and allows examination of the role of alumina on the AIC process. The deposited AIC films were examined by using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Raman spectroscopy, X-ray diffraction (XRD) and four probe measurements. It was found that AIC process is highly dependent on annealing temperature and can occur at annealing temperatures above 500°C through Al2O3 formation. Based on the presented data, a possible growth model is proposed to clarify AIC mechanism.

scholarly journals Pollutants harmful to health in herbal products detected by X-ray fluorescence spectroscopy

2020 ◽  
Vol 41 (2) ◽  
pp. 211
Author(s):  
Thais Hora Paulino Estanagel ◽  
Valquíria Miwa Hanai-Yoshida ◽  
Cristiane Renata Gaiotto Caldana ◽  
Waldemar Bonventi Junior ◽  
Marco Vinicius Chaud ◽  
...  
Keyword(s):  
Production Process ◽  
Chemical Elements ◽  
Low Cost ◽  
Absorption Spectrometry ◽  
Regulatory Agencies ◽  
Herbal Products ◽  
X Ray ◽  
Food Industries ◽  
Quantitative Analyses ◽  
Low Efficiency

The goal of this research was to evaluate the chemical composition of some herbal products consumed in Brazil through the Energy Dispersive X-ray Fluorescence (EDXRF). The methodology used encompassed the selection of 14 plants’ dried extracts and six ground plants. The qualitative and quantitative analyses of samples indicating the presence of As, Cr, Cu, Fe, Ni, Zn, Si, P, S, Cl, K, Ca, Ti, V, Mn, Co, Rb, Zr, Cd, Sn, Ba, Hg, Pb, Bi, Mo, and Pt in different concentrations. It is feasible that part of the contamination found in the herbal products come from the adjuvants/excipients used in the production process. Also, it was found that the extract production process seems to have a low efficiency for the extraction of the main chemical elements present in the ground plants. In the other hand, it has the benefit of reducing the contamination by harmful elements to health, such as heavy metals. EDXRF can replace atomic absorption spectrometry as low-cost and high precision technique to quantify all elements of interest in the pharmaceutical and food industries, within the limits established by regulatory agencies

Instantaneous Display of X-Ray Diffraction using a Diode Array Camera Tube

1968 ◽  
Vol 12 ◽  
pp. 165-173 ◽  
Author(s):  
Arthur N. Chester ◽  
Fred B. Koch
Keyword(s):  
Low Cost ◽  
High Sensitivity ◽  
Photon Flux ◽  
Diode Array ◽  
High Quantum Efficiency ◽  
X Ray ◽  
X Ray Imaging ◽  
Counting Statistics ◽  
Electron Imaging ◽  
Array Camera

AbstractThe silicon diode array camera tube, recently developed for PICTURFPHONE® service, was modified to permit X-ray imaging. High quantum efficiency is attained without the use of a phosphor screen, since each photon absorbed in the silicon target generates several hundred hole-electron pairs for each keV of its energy, most of which can he usefully collected. The sensitivity and resolution are adequate to allow a continuous television display of the diffracted intensity as a crystal is oriented. Particular advantages of this technique include; high resolution (< 25 μm); electronically variable magnification; direct oscilloscope measurement of X-ray spot Intensity profiles and relative spot intensities because signal current is directly proportional to photon flux; high sensitivity in the range of 0.6 to 5.0 Å, potentially limited only "by counting statistics; integration times variable from < 1/60 second to minutes; and expected low cost, since the camera tube has no complicated electron imaging, and is directly interchangeable Mith a standard television vidicon. Applications which are described include crystal orientation and X-ray topography.

scholarly journals Effects of Pr and Yb Dual Doping on the Thermoelectric Properties of CaMnO3

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1807 ◽  
Author(s):  
Cuiqin Li ◽  
Qianlin Chen ◽  
Yunan Yan
Keyword(s):  
Electron Microscopy ◽  
Figure Of Merit ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Thermoelectric Figure ◽  
X Ray ◽  
Transmission Electron ◽  
New Strategy ◽  
Low Toxicity

There has been research on CaMnO3 with natural abundance, low toxicity, and low cost as promising candidates for n-type thermoelectric (TE) materials. In this paper, Ca1−2xPrxYbxMnO3 with different Pr and Yb contents (x = 0, 0.01, 0.02, 0.03, 0.04 and 0.05) were synthesized by means of coprecipitation. With X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM), researchers characterized the phase structure and morphology of all the samples. The oxidation states of manganese were determined by X-ray photoemission spectroscopy (XPS). The role of Ca-site dual doping in the TE properties was also investigated. Increasing the Pr and Yb contents leads to decreases in the electrical resistivity and Seebeck coefficient, leading to a power factor of 3.48 × 10−4 W·m−1·K−2 for x = 0.04 at 773 K, which is its maximum. Furthermore, the thermal conductivity (κ) decreases with increasing x, and κ = 1.26 W m−1·K−1 is obtained for x = 0.04 at 973 K. Ca0.92Pr0.04Yb0.04MnO3 exhibit a ZT (thermoelectric figure of merit) value of 0.24 at 973 K, approximately 3 times more than that of the pristine CaMnO3. Thus, the reported method is a new strategy to enhance the TE performance of CaMnO3.

scholarly journals DNAzyme-Based Target-Triggered Rolling-Circle Amplification for High Sensitivity Detection of microRNAs

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2017
Author(s):  
Chen Liu ◽  
Jialun Han ◽  
Lujian Zhou ◽  
Jingjing Zhang ◽  
Jie Du
Keyword(s):  
Signal Amplification ◽  
Tumor Suppressor Genes ◽  
Low Cost ◽  
Rolling Circle Amplification ◽  
High Sensitivity ◽  
Rolling Circle ◽  
Highly Sensitive ◽  
And Control ◽  
High Sensitivity Detection

MicroRNAs regulate and control the growth and development of cells and can play the role of oncogenes and tumor suppressor genes, which are involved in the occurrence and development of cancers. In this study, DNA fragments obtained by target-induced rolling-circle amplification were constructed to complement with self-cleaving deoxyribozyme (DNAzyme) and release fluorescence biomolecules. This sensing approach can affect multiple signal amplification permitting fluorescence detection of microRNAs at the pmol L−1 level hence affording a simple, highly sensitive, and selective low cost detection platform.

scholarly journals X-ray spectral analysis development in Novosibirsk city (Electron probe microanalysis and X-ray fluorescence analysis using the synchrotron radiation)

2021 ◽  
Vol 25 (2) ◽  
pp. 155-173
Author(s):  
A. G. Revenko ◽  
Keyword(s):  
Spectral Analysis ◽  
Synchrotron Radiation ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Ussr Academy ◽  
Chemical Elements ◽  
Fluorescence Analysis ◽  
X Ray ◽  
Academy Of Sciences

Current article considers the contribution of X-ray physicists from the city of Novosibirsk to the formation and development of the two X-ray spectral analysis directions: electron probe microanalysis and X-ray fluorescence analysis using the synchrotron radiation. The research on geological topics at the Institute of Geology and Geophysics of the Siberian Branch of the USSR Academy of Sciences using the MS-46 electron probe microanalyzer of the French company CAMECA (since 1967) served as the basis for the development of methods for the quantitative X-ray microanalysis of rock-forming minerals as the methods for quantitative determination of the contents of elements with low atomic numbers in the long-wavelength X-ray region were still in their infancy. With the development and the improvement of the method’s technical base (microprobes JXA-5A, JEOL, 1975; Kamebaks Micro, CAMECA, 1981; JXA-8100, JEOL, 2003; JXA-8230, JEOL, 2016; electronic computing), the software for controlling the operation of devices and converting the measured intensities of the analytical lines into the concentration of elements continued to changed and improve. The first results of elemental analysis, obtained using the synchrotron radiation to excite X-ray fluorescence at the VEPP-3 accelerating ring at the Institute of Nuclear Physics of the Siberian Branch of the USSR Academy of Sciences, were published in1977. Inthe following years, at the station of elemental SRXRF, samples of various nature were studied — biological (bio tissues of the heart, liver, lungs, hairs, bones, plants), geological, environmental objects (soils, sediments, aerosols, etc.), archaeological sites as well as new technological materials. The procedures for the determination of chemical elements in low-mass samples (milligrams) in unique samples of lunar soil samples, biopsy material of human myocardial tissues, etc. have been developed. The scanning device at the elemental SRXRF station made it possible to obtain the information for reconstructing the climate change for different periods of time – from 100 to 1000 years. A new non-destructive method of confocal X-ray microscopy for studying micro-objects and visualizing the distribution of chemical elements in extended objects on this station are currently being developed.

scholarly journals X-ray in-line holography and holotomography at the NanoMAX beamline

2022 ◽  
Vol 29 (1) ◽  
Author(s):  
Sebastian Kalbfleisch ◽  
Yuhe Zhang ◽  
Maik Kahnt ◽  
Khachiwan Buakor ◽  
Max Langer ◽  
...  
Keyword(s):  
Electron Density ◽  
Low Dose ◽  
Focal Spot ◽  
Chemical Elements ◽  
Imaging Techniques ◽  
High Sensitivity ◽  
X Ray ◽  
X Ray Imaging ◽  
Dose Imaging ◽  
2D And 3D

Coherent X-ray imaging techniques, such as in-line holography, exploit the high brilliance provided by diffraction-limited storage rings to perform imaging sensitive to the electron density through contrast due to the phase shift, rather than conventional attenuation contrast. Thus, coherent X-ray imaging techniques enable high-sensitivity and low-dose imaging, especially for low-atomic-number (Z) chemical elements and materials with similar attenuation contrast. Here, the first implementation of in-line holography at the NanoMAX beamline is presented, which benefits from the exceptional focusing capabilities and the high brilliance provided by MAX IV, the first operational diffraction-limited storage ring up to approximately 300 eV. It is demonstrated that in-line holography at NanoMAX can provide 2D diffraction-limited images, where the achievable resolution is only limited by the 70 nm focal spot at 13 keV X-ray energy. Also, the 3D capabilities of this instrument are demonstrated by performing holotomography on a chalk sample at a mesoscale resolution of around 155 nm. It is foreseen that in-line holography will broaden the spectra of capabilities of MAX IV by providing fast 2D and 3D electron density images from mesoscale down to nanoscale resolution.

scholarly journals Limitations of bedside lung ultrasound in neonatal lung diseases

2021 ◽  
Author(s):  
Xiaolei Liu ◽  
Shuyu Si ◽  
Yiyi Guo ◽  
Hui Wu
Keyword(s):  
Lung Diseases ◽  
Neonatal Intensive Care ◽  
Lung Ultrasound ◽  
Clinical Symptoms ◽  
Low Cost ◽  
High Sensitivity ◽  
Ct Scanning ◽  
X Ray ◽  
Neonatal Lung ◽  
Chest X Ray

Lung ultrasound is a technique that has rapidly developed in recent years. It is a low-cost, radiation-free, and easy-to-operate tool that can be repeatedly performed at the bedside. Compared to chest X-ray, lung ultrasound has high sensitivity and specificity in the diagnosis of neonatal respiratory distress syndrome, transient tachypnoea of newborns and pneumothorax. Lung ultrasound has been widely used in neonatal intensive care units. However, it has limitations in some other lung diseases and cannot fully substitute for chest X-ray or CT. This review describes these limitations in detail and highlights that if clinical symptoms are not effectively alleviated after medical treatment or the clinical presentation is not compatible with the ultrasound appearances, then chest X-ray or CT scanning should be performed to avoid misdiagnosis and mistreatment.

scholarly journals Role of Ag+ in the Bioleaching of Arsenopyrite by Acidithiobacillus ferrooxidans

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 403
Author(s):  
Yan Zhang ◽  
Qian Li ◽  
Xiaoliang Liu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Acidithiobacillus Ferrooxidans ◽  
Large Scale ◽  
Low Cost ◽  
Xrd Analysis ◽  
Green Technology ◽  
Environmental Friendliness ◽  
X Ray ◽  
Pre Treatment

Arsenopyrite (FeAsS) is often associated with gold, but pre-treatment is necessary prior to gold leaching, mainly due to the gold encapsulation in the matrix of FeAsS. Bio-oxidation is attractive and promising, largely due to its simplicity, low cost and environmental friendliness. A critical problem that still impedes the large-scale applications of this green technology is its slow leaching kinetics. Some metal ions such as Ag+ have previously been found to expedite the bioleaching process. In this paper, the role of Ag+ in the arsenopyrite bioleaching by Acidithiobacillus ferrooxidans was investigated in detail by bioleaching experiments and a series of analyses including thermodynamics, X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Experimental results suggested that addition of 5 mg/L Ag+ to the leaching system could significantly improve the final As leaching efficiency from 30.4% to 47.8% and shorten the bioleaching period from 19 days to 15 days. Thermodynamic analysis indicates that Ag+ destabilises As2S2, As2S3 and S0 via forming Ag2S, which is confirmed by the XRD analysis on the phase transformation during bioleaching. SEM and XPS analyses further showed that Ag+ removed the passivating film consisting mainly of As2S2, As2S3 and S0 because Ag2S formed on the arsenopyrite surface from the start bioleaching of 36 h. In the presence of Fe3+, Ag2S could easily be dissolved to Ag+ again, likely leading to the establishment of the Ag+/Ag2S cycle. The bacteria utilised the two synergistic cycles of Fe3+/Fe2+ and Ag+/Ag2S to catalyse the bioleaching of arsenopyrite.

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