Element Contents Research Articles

Fatty Acid Composition, Oxidative Status, and Content of Biogenic Elements in Raw Oats Modified Through Agricultural Practices

The chemical composition of raw oat grain is responsible for the high dietary value and health-promoting properties of oat products. This article presents the results of a study investigating the biofortification of grain in two oat genotypes—hulless and hulled—through agronomic treatments: chemical plant protection against weeds and fungi and mineral nitrogen fertilization. The applied agronomic treatments induced different changes in the fatty acid profiles, content of tocopherols, macronutrients, and micronutrients in the grain of hulled and hulless oats. Plant health contributed to higher concentrations of unsaturated fatty acids and potassium in oat grain. In turn, nitrogen fertilization decreased the content of unsaturated fatty acids, potassium, and copper and increased the content of saturated fatty acids, calcium, and manganese in oat grain. At the same time, agronomic treatments reduced the tocopherol content of the grain, which implies that the nutritional value of oats increases in the absence of chemical plant protection agents. The correlations between the content of desirable chemical compounds and agronomic treatments were stronger in hulless oat grain, which may suggest that the agronomic modification of oat-based foods is more effective in this genotype. The content of exogenous alpha-linoleic acid C18:3 n-3 and alpha-tocopherol was higher in grain harvested from the control treatment (without chemical plant protection), whereas grain harvested from fully protected treatments accumulated more essential gamma-linolenic acid C18:3 n-6. The content of gamma-tocopherol and copper in oat grain was higher in the absence of nitrogen fertilization.

Uji Analisis Nikel Ore/Ni (Sampel Cek) Menggunakan Metode Press Pellet Berdasarkan Variasi Suhu Pengeringan, Waktu Pengeringan, dan Berat Sampel Timbangan Press

The purpose of the study was to determine the changes in nickel levels as a result of the analysis on the variation in temperature and drying time as well as the weight of press pellet scale samples from one of the same sample types. This research method is in the form of an experiment with a factorial research design from analysis parameters in the form of MC percentage and nickel ore content of Ni element. The results of the analysis showed that drying at 105°C and 125°C achieved a constant MC during a heating time of 5 to 6 hours. Meanwhile, at a temperature of 145-185 degrees Celsius with an interval of 2-6 hours, the MC level has experienced a constant weight of 44.44%. At the same temperature treatment, which is 105oC, different constant times are obtained. This is influenced by the difference in weight between the two samples, namely in the AP/5 and AP/6 range of 0.360 grams, while AP ORI weighs 1.8 kg. The results of the Epsilon 4 reading showed that the variation in drying temperature at 105°C to 185°C and drying time of 3-6 hours affected the nickel ore content in the range of 1.50% to 1.53%, close to the standard value of nickel 1.50%. The lower the temperature and drying time, the humidity level of the sample increases, causing the nickel ore content to decrease, while the higher the temperature and drying time increases the risk of nickel decomposition. The optimum temperature and drying time is 165°C for 2-4 hours. The press sample weight is between 8-14 grams resulting in a stable nickel content at 1.47%-1.50%, with an optimum weight of 10-14 grams for optimal sample thickness and density.

The Possibility of Environmentally Sustainable Yield and Quality Management of Spring Wheat (Triticum aestivum L.) of the Cornetto Variety When Using Sapropel Extract

Sustainable development is one of the main directions of modern agriculture. First of all, sustainability in the agricultural sector can be achieved through the possible abandonment of traditional mineral fertilizers. Many decades of using these fertilizers have led to the degradation of arable soils and to soil and environmental pollution. As a result, this causes reductions in yields and the environmental quality of agricultural products and affects the health of the population. An alternative to traditional mineral fertilizers may be the use of innovative organomineral fertilizers obtained from local resources. These include manure, humus, compost, sediments, etc. In recent years, fertilizers obtained from the sapropels of the bottom sediments of lakes have become widespread. Their distinctive feature is the environmental friendliness and completeness of the content of chemical elements and substances necessary for the development and growth of plants. In addition, the methods of obtaining and applying these fertilizers allow us to talk about their effectiveness in use. The range of applications of these fertilizers is diverse, from use in the form of a dry extract applied directly to the soil to the use of liquid suspensions used at various stages of processing and from pre-sowing seed treatment to watering and spraying plants at different periods of vegetation. Moreover, an important aspect is the research work on the variational use of sapropel fertilizers on different crops, with different methods of production and concentrations and at different stages of processing. This publication contains the results of a study of the effect of the obtained innovative sapropel fertilizer on productivity, wheat grain quality, and economic efficiency (Triticum aestivum L.). To identify the optimal concentration of sapropel extract, laboratory studies were carried out to determine the germination energy and germination of wheat seeds of different varieties when they were soaked in various concentrations: 0.4, 0.8, 1.2, 1.6, and 2.0 g/L. The best indicators of germination energy and germination of wheat seeds during treatment with the extract were obtained at a concentration of 1.2 g/L. The research was conducted at an accredited variety testing laboratory. A field experiment was conducted in the fields of the agrobiological station of North Kazakhstan University named after Manash Kozybayev. The treatment of the seeds was carried out by soaking them in sapropel extract to evenly distribute the substance. The scheme of the field experiment included the option of using foliar treatment with a solution of sapropel extract at the tillering stage. As a result of the application of the obtained extract in the field, environmental and socio-economic efficiency was noted. The conducted field studies note its positive effect and effectiveness on the morphological, qualitative, and quantitative indicators of the wheat harvest. In the areas where wheat seeds were pretreated, as well as where foliar treatment with the resulting sapropel suspension was carried out, the best yield indicators were revealed. In these variants of the experiment with pre-sowing and pre-sowing and foliar treatment with the sapropel extract solution, the yield was 3.63 and 3.81 tons per hectare, respectively. The introduction of sapropel extract at the stage of seed treatment before sowing, as well as foliar processing of wheat at the tillering stage, will increase the efficiency and profitability of the agricultural industry and obtain a synergistic effect in the form of socio-economic efficiency and environmental safety of production. In our opinion, this will contribute to the development of sustainable agriculture and the production of environmental products.

Investigation of Bi2MoO6/MXene nanostructured composites for photodegradation and advanced energy storage applications

This study presents nanostructured composite Bi2MoO6/MXene heterostructure by using hydrothermal method for photodegradation of the congo-red dye and also for energy storage devices. X-ray diffractometer (XRD), High Resolution Transmission Electron Microscopy (HRTEM), Field emission scanning electron microscope (FESEM) and X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) were performed to examine the structural properties along with surface area and porosity of the material. Due to addition of MXene the larger surface area and improved pore size help to quickly break down additional organic pollutants by adsorbing them. The band gap of Bi2MoO6/MXene nanostructured composite reduced to 2.4 eV suggesting transfer of electrons from VB to CB. Bi2MoO6/MXene exhibits a high (92.3%) photocatalytic degradation rate for a duration of 16 min which was verified using UV-visible spectroscopy, also scavenger test was conducted to ascertain the reactive agent along with the degradation pathway was confirmed by LCMS. Elemental content was also established by using inductively coupled plasma mass spectrometry (ICP-MS). For estimating energy storage capacity cyclic voltammetry (CV) was performed. It was observed Bi2MoO6/MXene nanostructured composite electrodes had specific capacitance of 642.91Fg− 1, power density of 1.24 kWkg− 1, and energy density of 22.32 Whkg− 1 at a current density of 5Ag− 1 also it exhibited 64.42% capacity retention having current density 20 Ag− 1 throughout 10,000 Galvanostatic charge discharge (GCD) cycles. High electrical conductivity of Bi2MoO6/MXene electrode was again examined by Electrochemical impedance spectroscopy (EIS). These findings demonstrate the potential of Bi2MoO6/MXene nanostructured composites in both photodegradation and energy storage applications.

Analysis of heavy metal characteristics and health risks of edible mushrooms in the mid-western region of China

This study determined the content of metal elements (As, Cd, Cr, Hg, Pb) in 9 edible mushrooms using ICP-MS, and evaluated the harm of long-term consumption of edible mushrooms to human health. The results showed that the concentrations of metal elements decreased in the order of Cd > As > Cr > Pb > Hg in edible mushrooms. The concentrations of Cd, As, Pb, and Hg were 22.95%, 8.20%, 1.64%, and 3.28% higher, respectively, than the maximum standards in China, whereas Cr did not exceed the limit. The detection rate of metal elements in Morchella esculenta (L.) Pers (M. esculenta), and Agaricus blazei Murill (A. blazei) were relatively high. The results of single factor evaluation and target hazard coefficient (THQ, HI) indicated that Dictyophora indusiata (Vent.ex Pers) Fisch (D. indusiata), A. blazei and M. esculenta were the main sources of risk. In addition, the HI values in ascending order were: Pb (0.43) < Cr (0.68) < Hg (0.92) < Cd (7.21) < As (14.02), indicating that Cd and As were the primary sources of health risks in edible mushrooms. To ensure food safety, it is recommended to strengthen the supervision of edible mushrooms, make reasonable choices, and reduce exposure levels of heavy metal pollution.

Coupling thermodynamic modelling with experimental study to reveal the evolutionary relationship of pore solutions, products, and compressive strength for lunar regolith simulant geopolymers

Alkali-activation is a highly promising approach for the in situ resource utilisation (ISRU) of lunar regoliths. However, the considerable variation in the composition of lunar regolith simulants can complicate the optimal design of geopolymer mixture ratios, necessitating an in-depth analysis of composition–performance correlations. This study proposes a calculation method that couples thermodynamic modelling with an experimental study to reveal the evolutionary relationship between the pore solution, product formation, and compressive strength. The results indicate that the modulus and dosage of the alkali activator can substantially change the relative content of reactive elements in the pore solution and affect the product type and content. Among these, [Si] and [Al] in the pore solution and gel production are key factors affecting the compressive strength of geopolymers. Understanding these composition–performance relationships is critical for offering essential guidance for performance-based, on-demand material design and optimisation.

Pengaruh Campuraan Bakteri Pelarut Fosfat dan Bakteri Penambat Nitrogen terhadap Pertumbuhan Tanaman Jagung pada Lahan Kelapa Sawit (Elaeis guineensis Jacq.) Menghasilkan

Intercropped farming utilizez used open spaces as an alternative to making empty land more productive. In certain periods, oil palm plantations have open spaces that can be used for planting intercropped plants. The problem is, in general, that oil palm plantations are planted on marginal land, such as inceptisol that is weak in phosphate, so if they are planted with palm oil, it is necessary to provide fertilizer with the main macro element content for palms to grow optimally, such as phosphorus (P) and nitrogen (N). Efforts can be made to meet the P and N requirements by applying combinations of microorganisms such as phosphate solubilizing bacteria (PSB) and nitrogen-fixing bacteria (NFB). The study aims to find out the effect of various dosages of PSB and NFB combinations on the growth and yield of corn crops, as well as the effect of corn crops on the growth and physiology of palm oil crops. The experiment was conducted at the Ciparanje Experimental Farm, Faculty of Agriculture, Padjadjaran University, January to April 2024. The study used a randomized block design (RBD) with six treatments repeated four times. The treatments included the application of a combination of Pseudomonas sp. and Azotobacter sp., which included: 10 kg/ha of PSB and NFB per plant, 20 kg/ha of PSB and NFB per plant, 30 kg/ha of PSB and NFB per plant, 40 kg/ha of PSB and NFB per plant, and 50 kg/ha of PSB and NFB per plant. Experimental results showed that the PSB and NFB mixture increased crop height 5.28%, stem diameter 3.19%, cob length 9.2%, cob diameter 9.8%, dried weight by 100 seeds 14.5%, and dried weight by corn plant 33.46%. The 40 kg/ha and 50 kg/ha dose of PSB and NFB per plant is the most efficient dose for the growth and of palm oil crops producing 2.

Gabbro of the mantle part of the ophiolite section in the Alapaevsky dunite-harzburgite-gabbro massif (Eastern zone of the Middle Urals)

Research subject. An intrusive body of gabbroids breaking through mantle peridotites (dunites and harzburgites) of the Alapaevsky ophiolite massif (Eastern zone of the Middle Urals). Methods. The contents of petrogenic elements were determined by the X-ray fluorescence method; the contents of rare and scattered elements were studied by the ICP-MS method. The age of gabbroids was determined by 147Sm-143Nd ID-TIMS by isotope dating. Results. The gabbro and their containing ultramafic rocks were established to be of almost the same age of about 580 Ма, which indicates their belonging to a single ophiolite association of the Vendian age. At the same time, the gabbroids of the Alapaevsky massif differ sharply from both isotropic and stratified gabbro of the crustal part of the ophiolite section, fragments of which are observed within the Eastern zone of the Middle Urals, in terms of a significantly reduced content of light REE, rare alkalis, barium, uranium and thorium, as well as the absence of Pb maxima on spider diagrams. Conclusions. The established features in the composition and intrusive occurrence of the gabbro of the Alapaevsky massif among mantle ultramafic rocks indicate that the studied rocks cannot be identified with gabbroids of the crustal part of the ophiolite association. This suggests that this rather large intrusion of gabbro may be analogous to small veins and dikes of gabbroids observed among mantle peridotites in a number of ophiolite massifs, such as Voikar-Synyinsky massif in the Polar Urals and the Samail ophiolite in Oman. The distribution specifics of rare elements on the spider diagrams of the gabbroids of the Alapaevsky massif, i.e., the presence of Sr and Ba maxima and Nd and Th minima, as well as the Harzburgite composition of the mantle restite containing the gabbro body under consideration, indicate that the Vendian ophiolite association of the Eastern zone of the Middle Urals formed in a suprasubduction (pre-arc) environment. A model for the formation of large masses of gabbro in the mantle part of the ophiolite section is proposed.

Microstructure and radiation shielding capabilities of Al-Cu and Al-Mn alloys

In this study, the microstructure and elemental analysis of aluminum-copper alloy type-2024, Al-2024, and aluminum-manganese alloy type-3003, Al-3003, have been investigated by using a scanning electron microscope (SEM) equipped with Energy dispersive spectroscopy (EDS) detector. Experimental and theoretical radiation shielding studies were performed to assess the radiation shielding capabilities of the studied alloys. Considering the radiation shielding theoretical assessment, some reliable software tools were used, such as Phy-X/PSD, MCNP5, NXCom, and MRCsC. The microstructural observations and results have shown the presence of second phases rich with the main alloying elements in both alloys. Considering Al-2024 alloy, coarse second-phase particles, having a size range of 8–15 μm, were found aligning in lines parallel to the rolling direction, whereas smaller ones, having a size range of 2–8 μm, were found decorated the grain boundaries. Also, dark holes represent the pull-out large particles separated during preparation indicated poor adhesion with the main matrix that could be a result of losing particle coherency with the matrix where the misorientation in-between the atomic planes increase. However, better adhesion of the second-phase particles with the matrix, which were found possessing smaller particle size, have been observed in the Al-3003 alloy indicating good coherency and better manufacturing process for the non-heat-treatable alloy. The second-phase particles in case of Al-2024 alloy were found containing significant content of high-Z elements like Cu with greater volume fraction equals 7.5%. On the other side, Al-3003 alloy has possessed second-phase particles which lack of high-Z elements with only volume fraction equals 3.5%. All the former besides the higher density and content of high-Z elements like copper in Al-2024 alloy in compare to Al-3003 alloy and pure aluminum, led to relatively better radiation shielding capabilities against energetic photons, the highest in the low energy band and decreases with the increase of the photon energy, and slight superiority in the case of fast neutrons with only 3%inc. over pure aluminum. For instance, the radiation protection efficiency (RPE) values dropped from about; 23.2, 21.6, and 20.8% at 0.100 MeV to only 5.7, 5.9, and 5.6% at Eγ = 2 MeV, for; Al-2024, Al-3003, and Al-Pure, respectively."Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.""confirmed"

Photoperiodic Effect on Growth, Photosynthesis, Mineral Elements, and Metabolome of Tomato Seedlings in a Plant Factory

The duration of light exposure is a crucial environmental factor that regulates various physiological processes in plants, with optimal timing differing between species and varieties. To assess the effect of photoperiods on the growth and metabolites of a specific truss tomato cultivar, three photoperiods (12 h, 16 h, and 20 h) were tested in a plant factory. Growth parameters, including plant height, stem diameter, fresh and dry weights of shoots and roots, photosynthetic characteristics, mineral content, and metabolome profiles, were analyzed under these conditions. The results indicated that prolonged light exposure enhanced plant growth, with the highest photosynthesis and chlorophyll content observed under a 20 h photoperiod. However, no significant correlation was observed between the photoperiod and the mineral element content, particularly for macro minerals. Metabolome analysis revealed that different photoperiods influenced the accumulation of metabolites, particularly in the lipid metabolism, amino acid metabolism, and membrane transport pathways. Long periods of light would enhance photosynthesis and metabolism, improving the rapid growth of tomato seedlings. Overall, this study provides a theoretical basis for understanding the responses of truss tomato cultivars to varying photoperiods in plant factories and proposes an optimizable method for accelerating the progress of tomato seedling cultivation.

The Impacts of Volcanic Activity on Microbial Growth—A Simulation Experiment in the Qiliao Section in Shizhu County, Chongqing, China

The impact of volcanic activity on microorganisms has always been a hot topic of discussion during geological history. Further studies are needed on the effects of volcanic activity on microbial growth in shale and the differences in nutrients provided by volcanic ash and other weathered rocks. This study’s results indicated that TOC contents at the bottom of the shale layer are 1.93–4.44% and 3.0% on average. The TOC contents at the top of the layer are 3.38–5.13% and 4.0% on average. It indicated that TOC contents at the bottom of the shale layer are smaller than the TOC contents at the top of the layer, suggesting that volcanic activity posed a long-term effect on biological growth. Seven different leachate concentrations were set in this experiment as follows: 1/10, 1/100, 1/500, 1/1000, 1/1500, 1/2000, and 1/2500. The results showed that the growth status of Pseudourostyla crassipes was affected by the addition of leachates with different concentrations compared to the control group. Additionally, the synthesis of chlorophyll a by Anabaena pseudoichthyoides was the most efficient with the 1/10 volcanic ash leachate. Through the analysis of major and trace elements in the solution before labeland after cultivation, the main elemental content of Ca2+, Mg2+, Na+, and K+ decreased by 3.8~87.24%, 75.96~92.70%, 86.56~95.67%, and 5.42~20.52% in the solution after microbial growth respectively. The trace elements B, Ba, Zn, and Fe decreased by 27.54~94.39%, 20~82.03%, 70.45~98.29%, and 99%. It was found that the B, Ba, Fe, and Zn elements decreased significantly. The nutrients from volcanic ash are the main factor promoting microbial growth. It can be indicated that the volcanic ash soaking solution has a higher content of nutrients when compared to the solubility of nutrients in volcanic ash compared to that of granite. A higher content of nutrients promotes microbial growth. The calculation results indicate that a volcanic eruption with a quantity of several 1010 m3 has a significant impact on microorganisms, lasting from tens of thousands to hundreds of thousands of years.

Metabolite and mineral contents in root, seed, testa, stem and leaf of Peganum harmala L

In order to investigate the distribution and accumulation characteristics of metabolites and mineral elements in different parts of Peganum harmala L. (P. harmala), and the synergistic or antagonistic effects between them. In this study, nuclear magnetic resonance (NMR), high performance liquid chromatography (HPLC) and inductively coupled plasma optical emission spectrometer (ICP-OES) were used to determine the contents of metabolites (proline, phosphorylcholine, choline, lysine, 4-hydroxyisoleucine, asparagine, acetic acid, sucrose, harmaline and vasicine) and mineral elements (Ca, Mg, K, P, Na, Cr, Cu, Fe, Zn, Mn, Ni, C, N) in five parts of P. harmala, including root, seed, testa, stem and leaf, and to analyze the relationship among the contents of metabolites and mineral elements. The results showed that the contents of acetic acid, proline, lysine, sucrose and Fe in the root were higher than those in other parts, and the contents of harmaline, phosphorylcholine, P, C, N and Zn in the seeds were the highest. The leaves were rich in vasicine, Na, K, Ca, Mg and Mn. The principal component analysis (PCA) showed that the cumulative variance contribution of the first two principal components was 69.00 %, and the loading values of K, Cu and sucrose were higher, which was consistent with the results of biplot and cluster analysis(HCA). Correlation analysis (CA) results showed that there was a strong overall correlation between the different components of seeds and leaves, and the correlation was greater than that of other parts. The results of this study are helpful to understand the correlation of functional traits among different parts of plants, and determine the internal mechanism of controlling functional traits and the proportional relationship between traits, so as to provide a reference for the resource utilization of plants.

Effect of heat treatment process on microstructure and properties of copper modified 1Cr11MoNiW1VNbN

Abstract The purpose of this study was to investigate the effects of Cu element content and heat treatment process on the microstructure and mechanical properties of 1Cr11MoNiW1VNbN martensitic heat-resistant steel. Microstructure was characterized by optical microscope (OM) and scanning electron microscope (SEM), tensile testing machine and impact testing machine were used to test the mechanical property. The results show that with the increase of Cu content, the precipitation of Cu-rich phase in the steel increases, while the formation of δ-ferrite and coarse carbides decreases, which significantly improves the strength of the material. When the Cu content is 2.14%, the tensile strength at 600 °C reached 542 MPa and the yield strength reached 484 MPa after normalizing at 1000 °C and tempering at 700 °C. With the increase of the normalizing temperature, the strength of the test steel decreases slightly, and the impact energy improved significantly.

Achieving Over 10% Efficiency in Kesterite Solar Cells via Selenium-Free Annealing

The unsatisfactory crystalline quality of the absorber layer has seriously impeded the development of kesterite photovoltaic devices, including a small grain size, a typical multi-layer structure, and inherent defects and defect clusters. Herein, we simultaneously modify the nature of the absorber bulk and the heterojunction interface by sputtering quaternary alloy targets and subsequent selenium-free annealing to improve the photovoltaic performance of Cu2ZnSnSe4 (CZTSe) solar cells. By adjusting the sputtering power, the elemental content and distribution in the precursor film are effectively controlled, which helps to obtain a single-layer large grain CZTSe absorber layer with better homogenization and compactness. The harmful inherent defects are significantly suppressed by such a modification. Simultaneously, the widened depletion width and enhanced built-in electric field, as well as improved band alignment at the heterojunction, enhance carrier collection. As a consequence, the efficiency of CZTSe solar cells has improved greatly from 6.91% to 10.12%. The single-target preparation strategy without selenization provides a simple and novel perspective for simultaneously adjusting the morphology and defects of kesterite photovoltaic materials, paving the way for promoting innovative industrial applications.

Enhancing room and cryogenic temperatures mechanical properties of FeCoCrNiMn high entropy alloys with high content of inexpensive element P

Enhancing room and cryogenic temperatures mechanical properties of FeCoCrNiMn high entropy alloys with high content of inexpensive element P

Enhancing corrosion resistance of Al alloy sheets with potential gradient by arc-sprayed Zn coatings

To improve the corrosion resistance and wide the application of Al alloy sheet in the engineering production, a corrosion potential gradient along the thickness of the Al alloy sheet was fabricated using the sprayed Zn layer. The process of arc spraying was employed to obtain the Zn coating with optimizing the parameters. Electrochemical testing was conducted on the surface of Al alloy sprayed with Zn layers at different depths. As the depth in the thickness direction increases, the content of Zn alloy elements gradually decreases and the potential gradually increases. This exhibits a gradual decrease in corrosion tendency. The results of electrochemical impedance spectra (EIS) revealed the existence of pitting corrosion on the surface of the Al alloy. This even extended to the underlying substrate material. In contrast, the Zn coating, when exposed to a corrosive environment, demonstrated the beneficial cathodic effect as a sacrificial anode and the protective function of a passivating film, thus mitigating corrosion. The gradual increase in charge transfer resistance in the impedance spectrum suggested that the corrosion resistance of the sample is increasingly improved. Therefore, it exhibited remarkable resistance to corrosion. Additionally, the SEM surface morphology and XRD pattern were utilized to further explain the corrosion mechanism of the arc-sprayed Zn coating. The Zn coating can provide sacrificial protection to the Al layer due to its higher negative potential and localized corrosion reactivity. This is attributed to the micro-galvanic couples formed between the Zn and Al layer, thus increasing the corrosion resistance of the sheets.

Distribution of tellurium, selenium, cobalt and gold in sulfide minerals: A case study of the Jiguanzui porphyry-skarn Au-Cu deposit, eastern China

The Jiguanzui deposit is a representative porphyry-skarn Au-Cu deposit in the Mid-Lower Yangtze River metallogenic belt, Eastern China, characterized by significant critical metal (Te, Se, Co) association. Previous study focused on the Te and Se distribution in the ores and pyrite minerals on deposit scale, this study present trace element geochemistry of various sulfide minerals (chalcopyrite, bornite, sphalerite, molybdenite) through LA-ICP-MS analysis, aiming to reveal the distribution of Te, Se, Co, and Au among sulfide minerals in this deposit. Except molybdenite, which host high concentrations of Te and Se, pyrite and chalcopyrite generally have higher Te contents than bornite and sphalerite, whereas bornite and chalcopyrite exhibited relatively high Se concentrations. Cobalt and Au are dominantly hosted in the pyrite and chalcopyrite, respectively, although the highest Au concentration up to 14 ppm was analyzed in pyrite. Principal component analysis of trace element contents and time-resolved LA-ICP-MS signal depth profiles indicate that Te occurred as Te-Ag minerals and mineral inclusions within the sulfides, whereas Se and Co are incorporated into the lattices of sulfide minerals. Principal component analysis of trace element contents in various sulfides exhibit intimate Pb-Bi-(Cu)-Au associations, suggesting that Au is present as tiny mineral inclusions coexisting with either Cu-Bi sulfosalts or Pb sulfides or sulfosalts. This case study also highlights that Te and Se hosted in pyrite are not recoverable with current recycling technologies.

Evaluation of the potentially toxic elements and radionuclides in the soil sample of Novaya Zemlya in the Arctic Circle

The study presented here elucidate the concentrations of radionuclides and potentially toxic elements in the soil samples around the Novaya Zemlya in the Russian Arctic zone, determined using HPGe gamma spectrometry, inductively coupled plasma optical emission spectrometry and direct mercury analyzer. The average detected concentrations for 226Ra, 232Th, 40K, 235U and 137Cs were 36.40, 46.06, 768, 2.06 and 4.71 Bq/kg, respectively. At many sampling sites, the concentrations of potentially toxic elements (Zn, Cu, Pb, Cd, Ni, and Cr) were higher than the natural levels. Positive Matrix Factorization analysis revealed the contribution of oil dumps (32%), natural sources (16%), bird colonies (32%) and atmospheric deposition (20%) for elevated elements content. In the case of radionuclides, the natural occurring contamination (38%) was primary source followed by dumped material (32%) and bird colonies (30%). The radiological risk from radionuclides was relatively high, yet still under permissible levels. For potentially toxic elements, Fe was predominant non-carcinogenic pollutant and Ni emerged as major carcinogenic contaminant. Keeping in view the high content of some elements, future studies are required to keep the human and ecological risk low, and to establish scientific grounds for the contribution of settled bird species. The findings of the study advance the present knowledge about the contamination of the study area and lays the path for further effort.

Mitigating Long Range Jahn‐Teller Ordering to Stabilize Mn Redox Reaction in Biphasic Layered Sodium Oxide

AbstractTo develop the next‐generation commercial oxide cathodes for sodium‐ion batteries, it is crucial to reduce the expensive Ni element content, and further regulate redox reaction of cheap transition metal elements such as Mn to elevate specific capacity. Nevertheless, the activation of Mn redox reaction (MRR) remains a challenge, and notably, MRR induces pronounced Jahn‐Teller effect, resulting in severe structural distortion and fast performance decay. Herein, activated by Na vacancies and weakened hybridization of O (2p)‐TM (3d‐t2g) orbital, a biphasic low‐Ni Mn‐based oxide P2/O3‐Na0.8Ni0.23Fe0.34Mn0.43O2 (P2/O3) exhibits reversible MRR, which performs the transition between Mn4+ and Mn3+ during charging and discharging. Due to the interlaced arrangement of P2‐type and O3‐type crystal domains in P2/O3, the long range Jahn‐Teller ordering is restricted to mitigate the cooperative distortion of MnO6 octahedron induced by MRR and the Jahn‐Teller effect is suppressed, ensuring sustained stable involvement of MRR in charge compensation. In addition, owing to the introduction of P2‐type phase, there is a significant reduction of the migration barrier for sodium ions and no obvious capacity decline after air exposure, leading to a marked enhancement in dynamic performance and air stability of P2/O3, respectively. Consequently, P2/O3 exhibits excellent electrochemical and processing performance.

Effects of alkaline extraction on behavior of rare earth elements in coal ashes.

The effects of alkaline extraction on the behavior of rare earth elements in coal ashes were investigated in the present study. Independent variables are the concentration of extractant and particle size of coal ashes. Sodium hydroxide was used as an extractant, and the molarity of the solvents varied from 1.0 to 7.0M. The coal ashes used here were fly and bottom ashes. Fly and bottom ashes were classified into four samples by particle size, with each categorized at both 45 and 300µm. The particle size distribution and crystalline characteristics of coal ashes, leaching, and the contents of rare earth elements in coal ashes after alkaline extraction were investigated, and the effects of independent variables on the content of rare earth elements in coal ashes were discussed. The test results showed that the dissolution of amorphous phase in coal ashes mainly occurred when the molarity was not more than 3M, while dissolution and precipitation such as geopolymerization and the formation of zeolite occurred simultaneously when the molarity was more than 5M. The dissolution and formation of precipitates such as geopolymer in the present study affected the variation of the rare earth element contents in the ashes. Besides, the ashes being smaller in size was more favorable for an increase in the rare earth elements in coal ashes.