Group Of Elements Research Articles

Status of trace metals and arsenic in sediments and catfish muscles (Clarias gariepinus) from the Eastern Tanzanian basin.

Trace metals and metalloids are groups of chemical elements that naturally occur in low concentrations and cycle in the environment driven by natural processes and human activities. They have a persistent and bio-accumulative tendency in the environment, and certain trace metals and metalloids have become a public health concern. This study assesses the concentration of eleven trace metals and a metalloid in sediments and catfish muscle from five study sites in the Eastern Tanzanian River basin. Forty catfish tissues and fifteen sediment samples were collected and analyzed using ICP-MS. Concentrations of As, Cd, Co, Pb, and Zn did not exceed the United States Environmental Protection Agency (USEPA) guideline for pollution of sediments, while Al Cr, Al, Mn, and V with values ranging from (118.54 to 70154.55) indicating moderately polluted. The stations Java-Sadaani and Matandu showed the highest Cr, Ni, and Cu concentrations, but the potential ecological risk index (RI) was low (RI < 95). In the catfish muscle tissue, the levels of Cd, Pb, Cu, and Zn did not surpass the EU and FAO/WHO limits and results ranged from 2.22 to 35.22mg/kg. Low levels of accumulation of Cd, Pb, and As were found in this study compared to catfish muscles from other studies, whereas the concentrations of other trace metals and metalloids analyzed had comparable results. Biota/sediment accumulation factors (BSAF) were all < 1. The weekly metal intake (MWI) results ranged from 6.89E-04 to 2.43E+01 μg/know-1week-1, indicating a low risk as the value did not exceed the FAO/WHO established Permissible Tolerable Weekly Intake (PTWI). The non-carcinogenic health risk result THQ was 4.43E-02 and the carcinogenic health risks result HI was 4.42E-05 which indicated tolerable levels of risks as both the values of the Target Hazard Quotient (THQ) and the Hazard Index (HI) was < 1, and the carcinogenic target risk (TR) is < 0.0001. The highest TR values were observed for Cr and Ni. We recommend a continued monitoring of the changes in trace metal levels in the environment and biota together with continuous public health education on the dangers of high levels of trace metals.

IMPORTANCE OF CHEMICAL ELEMENTS IN THE HUMAN BODY

Human body substancially needs chemical elements for various biochemical processes and metabolic reactions. Microelements are also nesesaary for in the human body. Microelements are a group of chemical elements that are found in the human body in very small quantities, in the range of 10-3-10-12%. Microelements perform essential functions in the human body. Even in microscopic quantities they are extremely effective. Microelements are part of the structure of biologically active substances: enzymes, hormones and vitamins. Their lack leads to serious diseases of the body. Microelements are involved in the metabolism of proteins, fats, carbohydrates, protein synthesis in the body, heat exchange, hematopoiesis, bone formation, reproduction, and immune reactions. In our body, the composition of chemical elements can change, which certainly affects our health and well-being, and various factors can cause an imbalance of useful elements.

Оценка эффективности метода гиперплоскостей в задаче частичной идентификации неизвестного вещества

The problem of partial identification of a homogeneous medium of unknown chemical composition is investigated. The medium is subjected to repeated transillumination by X-ray fluxes collimated in energy and direction. According to the results of measuring the flux density of radiation entering and leaving the medium, it is necessary to establish the difference in the chemical composition of the medium from some in advance given substances. It is assumed that the measurements of radiation fluxes contain errors for which their maximum relative values are known. As a mathematical basis for the study the method of hyperplanes proposed earlier by the author is taken. The results of numerical calculations performed for problems of various dimensions and for a number of groups of specific chemical elements. Numerical estimates have been obtained for several groups of organic substances, under which any two substances will be successfully distinguished from each other by the results one single measurement experiment on transillumination. Using the hyperplane method in the identification problem for groups of organic substances showed enough high efficiency. As a result of computer calculations, it is shown that that any of the 1287 considered pairs of organic substances is well distinguishable if the total relative measurement error of the probing radiation flux does not exceed 9.726 \%. The analysis of the dependence of the mass attenuation coefficients of radiation from the atomic number for all chemical elements of the periodic system has been carried out and conclusions about the behavior of the identification accuracy with an increase in the dimension of the problem were done. A justification is given that the hyperplane method will be effective in solving the problem of identification for other groups of chemical elements and identification accuracy does not get worse as the dimension of the problem increases.

Doping of group IVB elements for nickel-rich cobalt-free cathodes

Hetero-element doping is a promising strategy to improve the cycling stability of nickel-rich cobalt-free cathodes for the next-generation high energy-density Li ion batteries. To make doping effective, it is important to understand the mechanism of how the dopants regulate the electronic band, lattice parameter adjusting, or hetero-phase formation to achieve high stability. In this study, we investigate LiNi0.9Mn0.1O2 cathodes doped with IVB grouping elements via multiple characterization techniques. By utilizing in situ XRD and TEM methods, we found that the stronger Ti–O bond effectively improves the cathode stability via a dual protection mechanism. Specifically, the bulk lattice of cathode is well-preserved during cycling as a result of the suppressed H2-H3 phase transition, while a in situ formed Ti-rich surface layer can prevent continuous surface degradation. As a result, the 5% Ti doped LiNi0.9Mn0.1O2 cathode exhibits a high capacity retention of 96% after 100 cycles. Whereas, despite IVB group elements Zr and Hf have stronger bonding energy with oxygen, their larger ionic radii actually impede their diffusion into the cathode, thereby they can not improve the cycling stability. Our findings uncover the functional origin of doped elements with their dynamic modification on cathode structure, providing mechanistic insights into the design of nickel-rich cobalt-free cathodes.

Rare earth elements application in agriculture

Rare earth elements (REEs) are a group of chemical elements that include lanthanides as well as scandium and yttrium. Today REEs are used in various industries, such as agriculture where they are used as micro fertilizers and feed additives, the latter being used in medicine as well. There is no indication that REEs might be essential for any form of life. At lower concentrations, they can favorably influence certain physiological processes of plants (enzyme activity, hormone content, photosynthesis, seed germination, plant growth, etc.). They may induce an increase in some antioxidant systems and thereby increase the tolerance of plants to environmental stressors caused by high concentrations of heavy metals, herbicides, lack of water and essential nutrients, UV radiation and oxidative stress. Thus, their favorable effect was documented regarding the yield of cultivated species as well as the effect of their chemical composition on the content of vitamin C, soluble sugars and essential elements, reduction of the concentration of toxic heavy metals, improvement of the quality of wheat kernel for different uses. REEs have been commonly used as feed additives in organic and inorganic forms in livestock production. The available literature on the use of REEs as feed additives in livestock suggests positive outcomes (affected various physiological processes, increase in milk, egg and meat production, promoted growth and reproductive performance), but further investigation and results are needed before extending their use to zootechnical purposes.

STUDY OF SMOKE OF EXHAUST GASES OF INTERNAL COMBUSTION ENGINES OPERATING ON DIESEL FUEL WITH BIOPLE ELEMENTS

The most popular vehicle in the world is the car, their number is constantly increasing. Older cars are being replaced by improved models, and new car designs and systems are being developed and implemented. Areas of improving the design of the car, in addition to improving safety, fuel economy and comfort, include improving environmental safety, as the car is a source of environmental pollution. Internal combustion engines are the main source of man-made air pollution. The operation of the internal combustion engine is accompanied by the formation of emissions of sulfur dioxide and nitrogen oxides, which is the cause of acid precipitation. Smog and the greenhouse effect due to hydrocarbon emissions are inevitable, and solid dust and soot particles cause weather changes (cold, fog and rain). All these factors, together with industrial emissions, are leading to global climate change. Fuel evaporation, crankcase and exhaust gases are among the main phenomena of harmful effects of the internal combustion engine on the environment and account for up to 78%. This article highlights the problem of soot formation in the soot filters of the car exhaust system. Groups of chemical elements that are part of exhaust gases are considered. The existing directions of reducing the toxicity of exhaust gases are analyzed. The influence of different types of fuel on the toxicity of exhaust gases and soot formation is determined. The principle of soot filter operation during filtration and regeneration is described. Types of regeneration and the principle of their action are described. Smoke of soot filters at different mileage was studied. The principle of using the Infracar D smoke meter is described. An experimental study of ultrasonic soot filter cleaning was performed. Based on the information received, conclusions are drawn.

Study applications extract of plant various Artemisia in the medical field: Review

The Artemisia plant which grows in most desert areas of the world, One of the important plants at all times, as it has been scientifically and practically proven to be non-toxic, By taking it orally, whether in powder or solution form by humans, And using chemical statements and measurements of chemical devices for its alcoholic and aqueous extract, it contains A wide range of compounds, most of which are anti-oxidants. It helped to use it extensively in the industrial field in the form of pesticides, and in the medical field in the prevention and treatment of parts of the digestive system, increasing the activity of the enzymes of the heart, liver, pancreas. In addition to containing a group of chemical elements that lead to an increase in the effectiveness of these enzymes, As well as to combat cancer cells using the alcoholic extract from it, and because of the presence of phenols in its composition, it was used as anti-bacterials. The most important thing is that it is used in some countries of the African continent to treat some cases of the Corona epidemic. In European countries, it is currently being studied and developed for use in the treatment of Corona, because of its ease of access, simplicity of production, licenses when selling and the absence of side effects when using it, and this helped the world to eliminate the global pandemic.

ГЕОЭКОЛОГИЧЕСКАЯ ОЦЕНКА СОВРЕМЕННОГО СОДЕРЖАНИЯ ЦИНКА В ПОЧВЕННОМ ПОКРОВЕ УРБАНИЗИРОВАННЫХ ТЕРРИТОРИЙ ЮГА РОССИИ

Anthropogenic and technogenic processes in the urban environment significantly change the chemical composition of the soil cover. One of such processes influencing the state of the urban soil is the process of soil cover pollution with heavy metals. Heavy metals are biochemically active and highly toxic; they are found in various components of the natural environment, as well as in systems of anthropogenic and technogenic origin. They have the property of accumulation in the body of living beings and have a negative effect on their condition. This group of chemical elements includes lead, zinc, chromium, mercury, copper, iron and other metals. Exceeding the permissible concentration of heavy metals in the soil of an urbanized area and their toxic effects pose a significant danger to humans. Contamination of the soil cover of an urbanized area with heavy metals is associated with the impact of a large number of sources of anthropogenic and technogenic origin, namely, energy and industrial facilities, city infrastructure support systems, zones of construction activities and storage of materials or waste. One of the main highly toxic chemical pollutants of the soil cover of the urbanized territory belonging to the group of heavy metals is zinc «Zincum-Zn». The article describes the results of a 2020 study of the current zinc content in the soil cover of the city of Astrakhan. The relevance of the work lies in the geochemical analysis of the content of heavy metals in the soil of the city of Astrakhan. The aim of the work was to study the modern process of soil contamination of the city of Astrakhan with zinc. The work was based on the task of determining the degree of exceeding the hygienic standards of the maximum permissible concentration of zinc in soil samples. Methods of geographical and ecological research were used in the work, soil samples were collected, followed by determination of the concentration of a substance in each of the soil samples in a certified laboratory. In the course of the work, the indicators of exceeding the maximum permissible concentration of zinc in the soil of the city of Astrakhan were determined and the presumptive sources of pollution were identified.

METODOLOGIA PARA A DETERMINAÇÃO DO VALOR DE POTENCIAL TURÍSTICO DE TRILHAS INTERPRETATIVAS EM ÁREAS NATURAIS

The attractive potential of an interpretive trail is closely related to biodiversity and should encourage and promote environmental conservation. Therefore, it is important that it can be quantified, considering the largest number of possible elements. In order not to compromise, the determination of these potential, subjective items should be avoided. The aim of this research was to develop a methodology based on a mathematical formula that can determine the touristic potential value of interpretive trails in natural areas, relating to different environmental variables and their values. The methodology consisted of grouping elements (1-condition of trail, 2- components that increase value, 3- components that reduce value, 4- environmental quality of the trail, which increase the value of the tourism potential of the interpretive trail) relative to variables, determining criteria and setting punctuation to develop the mathematical formula. After developing the formula, a test was applied using the Tatu Trail at Prosa State Park, Campo Grande, MS. The calculation determined a score of 5.9 for the touristic potential of the trail evaluated.

Optimization of chemical composition of steel for gearweels of agricultural industry engineering

Development of new steels in mechanical engineering to create alloys with predetermined properties that can minimize material and labor costs during their processing. Optimization of the chemical composition of the alloy based on the analysis of the impact of complex alloying on the structure and consequently on the manufacturability of steel. This will reduce the level of internal intensities in the heat treatment process. Based on the analysis of existing trends in mechanical engineering, it is established that the complexity of modern parts of gearweels imposes on the material increasing technological requirements for stamping, machinability, weldability, hardenability, cementation and gouging in the hardening process which explains the need for alloying steel via a certain group of chemical elements. The influence of different compositions of steels for gearweels on the level of internal intensities occurring in parts during heat treatment is studied. The optimal composition of complex-alloyed cementing steel is established.

Order Statistics and Optimal Selection of Unit Elements in DACs to Enhance the Static Linearity

The benefits of the ordering technique to improve the static linearity performances of digital-to-analog converters are discussed. Different techniques of grouping or sequencing elements are studied for segmented, binary or unary DAC architectures. The statistic of ordered elements and their properties are reviewed and studied. Then, the optimal selection of elements for a binary or unary use is discussed. The paper also estimates the limit caused by gradient, a systematic offset, and a non detected interval in the comparator used for the sorting. Results show that the use of segmented architecture with 8~16 groups of elements sorted and optimally selected grants 2~3 bits more in the performance. The benefit can become 5 bits for 128 groups at the cost of more significant efforts for the ordering.

Gas-Geochemical Parameters of Bottom Sediments in the Northern Part of the East Siberian Sea and Podvodnikov Basin of the Arctic Ocean

New data on the gas and chemical composition of bottom sediments of the marginal-shelf part of the East Siberian Sea, continental slope, and Podvodnikov Basin of the Arctic Ocean are presented. The genetic parameters of seven groups of epigenetic hydrocarbon gases are determined. The distribution areas of the potential oil–gas, gas–oil, and oil deposits have been revealed. Three groups of chemical elements have been specified in bottom sediments. Their maximum concentrations are related to particular geostructures of the area studied.

ТЕМАТИЧЕСКИЕ ГРУППЫ КОЛОРОНИМОВ В МЕДИЦИНСКОЙ ТЕРМИНОЛОГИИ

It is proved that there is an increased interest in the study of color in various aspects of science. The relevance of the research is determined by the interest in the problems associated with the theoretical and practical study of terminological word formation of color in medicine. The aim of the present study is to investigate colorview in medical terminology. It is revealed that medical dictionaries contain terms that contain a word that denotes colora coloronym, which is used to clarify and specify the symptom, sign designated by the term. Consequently, a thematic range of chemical elements is considered, indicating the name of color shades, types of medicinal plants and their colors. It is analyzed that medical terms with a coloronym have a number of features, such as the duration of functioning, participation in the creation of new terms. It is revealed that the thematic group of coloronyms in folk names of medicinal plants indicate the color, appearance (white spots on prickly green leaves) and the valuable medicinal properties of this plant. It is considered that in modern linguistics, the dynamics of the surrounding world is also manifested in the emergence of new associations associated with a certain term of color, which leaves an imprint on its meaning. Thematic groups of chemical elements, substances, minerals and acids with coloronyms indicating the name of color shades are analyzed. It was found that each coloronym denotes its own thematic series and has a number of features in medical terminology. Thematic group colorview has characteristic symptoms and signs of disease. As a result of the analysis of the content of coloristic names, the following thematic groups were identified, differentiated on the basis of the spheres of functioning of the term: names of internal diseases; names of skin diseases; names of plants; names and colors of chemical elements; blood analysis.

Experimental Simulation of Processes of Ore Leaching from Lyubov Deposit (Transbaikalian Region)

To identify the mobile chemical elements in the processes of acidic weathering in the landscapes of Lyubov gold deposit (Transbaikalian Region), experiments on sulfuric acid leaching of gold–quartz ores (up to 2% of sulfides content) from the deposit are carried out. The chemical composition of ore samples is determined, and the major and minor minerals are described. The compositions of the ore and rock-forming minerals are studied by the methods of X-ray diffraction and chemical analyses and electron microscopy. According to the experimental results, a group of mobile chalcophile elements (Pb, Zn, Cu, Cd), elements of V group (As, Sb, Bi) attributed to sulfides and sulfosalts, and a group of rare-earths and trace elements are revealed. Various dynamics of leaching these groups of chemical elements is recorded. It has been found that even if the contents are below bulk earth values, lanthanides, cesium, chromium, and germanium rapidly move to the acidic solution.

Arsenic and selenium in shore soils and bottom sediments of Samara city ponds

Arsenic and selenium are included in the group of chemical elements of the first hazard class, which confirms the need to analyze their content in natural environments of natural and man-made ecosystems during ecological and biogeochemical monitoring. By their chemical properties, arsenic and selenium are metalloids or semimetals. In very low concentrations, they are necessary for the normal functioning of the organisms, but with increasing concentrations in the habitat or food they show high toxicity. Particularly dangerous is the accumulation of arsenic and selenium in accumulative environments and landscapes, which include soils and confined water bodies. For the urban ecosystems of the Samara Region, earlier monitoring of the content of arsenic and selenium in the components of their accumulative landscapes was not carried out, which confirms the relevance and practical significance of the presented materials. The authors carried out ecological and geochemical studies of the accumulation of arsenic and selenium in coastal soils and bottom sediments of twenty ponds located in the Samara city within the coastal slope of the Saratov reservoir (Volga slope) and on the watershed between the Saratov reservoir and the Samara River. The results analysis showed a relatively low level of arsenic accumulation in the analyzed substrates of the studied ponds. Compared with the level of regional background for the Middle Volga, the studied accumulative aqual landscapes are noticeably enriched in selenium (2-15 times). The technogenic influx of arsenic and selenium into the accumulative landscapes of the Samara city may be associated with the activities of metalworking and machine-building enterprises, as well as thermal power plants. The materials presented in the paper concerning the content of arsenic and selenium in coastal soils and bottom sediments of urban ponds in the Samara city can be considered as pioneering for the region and subsequently used in the ecological and geochemical monitoring of regional urban ecosystems.

Activity of the Photosynthetic Apparatus in Phaseolus vulgaris L. Leaves Under the Cadmium Stress

The development of civilisation, urbanisation and industrialisation cause to ever increasing contamination of the natural environment. Cadmium belongs to this group of chemical elements, which represent a serious threat, not only for the proper development of plants but also for the health of humans and animals. Hence, the interest of scientists in the toxic effects of this kind chemical elements on the various life functions of organisms. The aim of this study was to investigate the effect of cadmium nitrate aqueous solutions on photosynthetic activity and degree of disorganisation of cell membranes in leaves of common bean (Phaseolus vulgaris L. cv. ‘Laurina’). A fully formed second leaves were wetted with cadmium solutions nitrate (Cd(NO3)2) at concentrations of 5 and 10 mM. With the increasing of cadmium concentration and time of its application (20, 40, 60 min and 24 h), the changes in the fluorescence of bean leaves were observed. Under the influence of cadmium ions, damage occurred both on the edge and the central part of the leaves, and then the whole surface. The highest changes of the chlorophyll fluorescence values were observed after 24 h of application the aqueous cadmium solutions. Use of SPAD chlorophyll Meter, the reduction of chlorophyll content was noticed over time. The flow of electrolytes from the bean leaves was increased with the time and concentration of applied cadmium compounds.

Petro-Geochemical and Statistic Studies of the Nimba Region in the Republic of Guinea

Petro-Geochemical and Statistic Studies of the Nimba Region in the Republic of Guinea

Ecotoxicants Content of Sanguisorba officinalis L., Growing on Mining Disturbed Lands of Kemerovo Region

Ecotoxicant content – heavy metals and radionuclides in embryonic soils and herbal medicinal products of Sanguisorba officinalis L. of the rose family (Rosaceae) in the circumstance of technogenicallydisturbed lands was analyzed, in example of the rock waste disposal areaof the Kedrovsky coal pit in Kemerovo region. It was experimentally proved that the embryonic soils of the coal dump is characterized by largeelemental variation. Analysis revealed that the raw materials of Sanguisorba officinalis L. more accumulates such metals as Fe(61, 95mg/kg), Mn (33, 46 mg/kg), Zn (17, 53 mg/kg) and Cu (12, 35mg/kg), which are related to biophilic metals. Technogenical group ofelements – Pb, Cd, Cr, Ni, Co, are with in 0,04 … 1,52 mg/kg. It was alsoexperimentally proved that the main share in overall radioactivity ofembryonic soils and rhizome and roots of greaterburnet falls to naturalradionuclides, especially K-40. The share of Cs-137 and Sr-90 are about7% in embryonic soils and 85 in rhizome and roots of burnet. Ecological hygienic assessment of Sanguisorba officinalis L. herbal medicinal products has shown the MPC no-exceedance of heavy metals and radionuclides, provided for the plant based BAA.

Sustainability of rare earth elements chain: from production to food – a review

Rare earth elements (REE) are a group of chemical elements that include lanthanoids (lanthanum to lutetium), scandium and yttrium. In the last decades, the REE demand in the industry and other areas has increased significantly. In general, REE have shown low concentrations in soils, plants, water and atmosphere, but they may accumulate in such environments due to anthropogenic inputs. In areas where there is REE contamination, the slow accumulation of these elements in the environment could become problematic. Many studies have shown environmental areas contaminated with REE and their toxic effects. Thus, it is important to review, in order to improve the current understanding of these elements in the environment, showing the effects of REE exposure in mining, soil, water, plants and food. Besides, there are few suppliers and a limited quantity of these elements in the world. This paper suggests options to improve the sustainability management of REE chain.

Characteristics of the manifestation of transboundary pollutants transfer on the territory of Altai

A rationale is given to the current importance of studying the consequences of the longterm pollutants transfer from industrial centers of East Kazakhstan. Available data on the pollution of the environmental components by elements of polymetallic ores are presented. An additional study was made of the characteristics of the distribution of 50 chemical elements in the snow cover and in the leaves of black poplar on the territory of Altai neighboring the East Kazakhstan region. A weak acid character of atmospheric precipitation, caused by increased sulfur content, is revealed. Annual flows of sulfur and nitrogen are estimated for the territory of the region. Distribution trends for chemical composition parameters of snowmelt and dust on the territory of Altai are determined. Two main groups of chemical elements in the natural environments studied are identified, namely the rock group represented by rock-forming elements, and the ore group dominated by polymetallic ores. It is found that the territory of the region polluted by these elements looks like a tongue-shaped halo with the area of 30 thou km2 extended along the northeastern direction over more than 400 km, with an average width of 100–120 km. Within the halo there is an increase in content of all the elements under study when approaching the territory of the East Kazakhstan region. It was also found that the chemical composition of snow dust on the territory of Altai is similar to the composition in the emissions from Kazzinc Metallurgical Complex in Ust’-Kamenogorsk which is supposedly one of the main sources of pollutants transferred to Altai.