Chemical Composition Research Articles

Abrasion Wear Resistance of Precipitation-Hardened Al-Zn-Mg Alloy

The heat treatment of aluminum alloys is very important in industries where low weight in combination with high wear resistance, good strength, and hardness are important. However, depending on their chemical composition, aluminum alloys are subjected to different mechanical and thermal treatments to achieve the most favorable properties. In this study, an Al-Zn-Mg alloy was heat-treated including solution annealing at 490 °C for 1 h with subsequent artificial aging at 130, 160, and 190 °C for 1, 5, and 9 h. The hardness (HV1) and abrasive wear resistance with three different abrasive grain sizes were measured for all samples. The highest hardness was measured for the samples artificially aged at 130 °C/5 h, 227 HV1, while the lowest hardness was measured for the samples aged at 190 °C/9 h. The highest and the lowest wear resistance was also observed for the same state, i.e., artificially aged at 130 °C/5 h and 190 °C/9 h, respectively. The critical abrasive grain size was detected for some samples, where a decrease in wear rate was observed with an increase in the abrasive grain size from the medium value to the largest. The Response Surface Methodology (RSM) was applied to demonstrate the influence of the input parameters on the material wear rate.

Standing and shed litters alter plant growth in disturbed and undisturbed soils differently

Abstract Plant species affect key ecosystem processes like nutrient cycling and overall ecosystem productivity through their litter. The outcome of litter effects is largely determined by its decomposability, which directly effects soil properties. If litter remains standing or unshed (i.e. marcescent), its final decomposability can be increased by photodegradation of recalcitrant structures (like lignin). If the litter is immediately shed, its decomposability largely depends on its original nutrient content. Moreover, plant species may affect soil also through other, more direct effects. It is however unknown whether marcescent and immediately shed litters affect soil, and by that plants, differently, whether direct effects of plants on soil interact with those of marcescent and shed litters, and whether these interactions are consistent under different soil conditions. We set up a pot experiment, where we tested the effects of originally marcescent and shed litters (both added on the soil surface of the pots) on three grassland species (Bromus erectus, Filipendula vulgaris and Plantago media) in contrasting soils from long‐term stable ancient grassland and grassland restored on arable land 20 years before. We also tested how litter types and plant species affect soil chemical properties and microbial community (characterised by PLFA markers). Marcescent litter contained a lower amount of nutrients, but still increased plant biomass more than shed litter, although only for F. vulgaris (likely due to mobilisation of soil nutrients). The effect of litter on soil chemical properties and microbial community was low. These were largely affected by the plant species growing in the pot. The effect of these species on the microbial community was stronger in the undisturbed soil of ancient grasslands, while plant species affected mainly chemical properties in disturbed soil of restored grasslands. B. erectus slowed down the decomposition of both litter types in restored grassland soil. The effect of marcescent litter on living plants was significant but species‐specific and depended on soil conditions. Marcescence seems to have a stronger effect on plants in disturbed soil, which indicates its importance for recovery of the ecosystem after disturbance. Read the free Plain Language Summary for this article on the Journal blog.

Ab initio molecular dynamics study on the local structures and solid/liquid interface in liquid Al-Ti and Al-B-Ti alloys

High-purity aluminum, owing to its excellent physical and chemical properties, finds extensive applications across various fields. A comprehensive understanding of the local structure of liquid Al-based alloys and the characteristics of solute atoms at the forefront of the solid-liquid interface is highly advantageous for the purification of aluminum. Ab initio molecular dynamics (AIMD) simulations were employed to study the local structures, element interactions and electronic structures in Al-Ti and Al-B-Ti melts, together with the behaviors of Ti atom and B-Ti atom pair at the solid/liquid interface forefront of Al. In the Al-B-Ti ternary melt, there are stronger interactions between B and Ti atoms than those between Al and B atoms as well as between Al and Ti atoms. The introduction of B atoms leads to the disruption of Al-Ti bonds and the formation of B-Ti bonds, thereby altering the state of Ti atoms in the melt and then influencing their diffusion properties. The dynamic process of B-Ti bond formation in the melt has been elucidated. The bond angle distribution function shows that the geometric configuration around Ti atoms in the Al melt undergoes significant changes with the addition of B atoms. A strong hybridization occurs between the 3d orbital of Ti atom and the 2p orbital of B atom. Moreover, a notable charge accumulation between B and Ti atoms, indicates the strong interaction between them. The addition of Ti atom can promote the migration of the Al solid/liquid interface. The B-Ti bond is very stable at the forefront of the Al solid/liquid interface, and the formation of B-Ti bond significantly drag the migration of the Al solid/liquid interface.

Microhardness and elemental analysis of ion-releasing restoration/ dentin interface following enzymatic chemomechanical caries excavation

BackgroundThis study was conducted to compare chemical, elemental and surface properties of sound and carious dentin after application of two restorative materials resin-modified glassionomer claimed to be bioactive and glass hybrid restorative material after enzymatic chemomechanical caries removal (CMCR) agent.MethodsForty carious and twenty non-carious human permanent molars were used. Molars were randomly distributed into three main groups: Group 1 (negative control) - sound molars, Group 2 (positive control) - molars were left without caries removal and Group 3 (Test Group) caries excavated with enzymatic based CMCR agent. After caries excavation and restoration application, all specimens were prepared Vickers microhardness test (VHN), for elemental analysis using Energy Dispersive Xray (EDX) mapping and finally chemical analysis using Micro-Raman microscopy.ResultsVickers microhardness values of dentin with the claimed bioactive GIC specimens was statistically higher than with glass hybrid GIC specimens. EDX analysis at the junction estimated: Calcium and Phosphorus of the glass hybrid GIC showed insignificantly higher mean valued than that of the bioactive GIC. Silica and Aluminum mean values at the junction were significantly higher with bioactive GIC specimens than glass hybrid GIC specimen. Micro-raman spectroscopy revealed that bioactive GIC specimens showed higher frequencies of v 1 PO 4, which indicated high level of remineralization.ConclusionsIt was concluded that ion-releasing bioactive resin-based restorative material had increased the microhardness and remineralization rate of carries affected and sound dentin. In addition, enzymatic caries excavation with papain-based CMCR agent has no adverse effect on dentin substrate.

Properties, Synthesis and Emerging Applications of Graphdiyne: A Journey Through Recent Advancements.

Graphdiyne (GDY) is a new variant of nano-carbon material with excellent chemical, physical and electronic properties. It has attracted wide attention from researchers and industrialists for its extensive role in the fields of optics, electronics, bio-medics and energy. The unique arrangement of sp-sp2 carbon atoms, linear acetylenic linkages, uniform pores and highly conjugated structure offer numerous potentials for further exploration of GDY materials. However, since the material is at its infancy, not much understanding is available regarding its properties, growth mechanism and future applications. Therefore, in this review, readers are guided through a brief discussion on GDY's properties, different synthesis procedures with a special focus on surface functionalization and a list of applications for GDY. The review also critically analyses the advantages and disadvantages of each synthesis route and emphasizes the future scope of the material.

Phenolic fingerprint of Macedonian propolis

Propolis is a chemically complex resinous material collected by honeybees (Apis mellifera) from tree buds and resins, comprising plant exudates, secreted substances from bee metabolism, pollen and waxes. Its chemical composition depends strongly on the plant sources available around the beehive, which have a direct impact оn the quality and bioactivity of the propolis. In this study, the composition of phenolic compounds in 13 Macedonian propolis extracts was investigated by HPLC-DAD-ESI-MS/MS. Overall, the UV spectra, the MS and MS/MS data allowed the identification of 36 compounds. The major constituents of propolis were phenolic acids (caffeic and coumaric) and their esters (methyl, (iso)prenyl, benzyl, phenylethyl, cinnamyl), flavonols (quercetin, kaemferol), flavones (chrysin, apigenin, acacetin), flavanonols (pinobanksin) flavanones (pinocembrin naringenin, hesperetin, pinostrobin) and their methylated/esterified derivatives. The results reveal that Macedonian propolis contains a diversity of phenolic compounds confirming that it is a poplar type of propolis with higher phenolic content (ranging from 43.75–637.94 mg/g) than reported in previous studies in the region and beyond in Europe (< 80 mg/g). This suggests the potential significance of Macedonian propolis as a valuable source of bioactive compounds with health benefits as well as for unlocking its economic potential for industry and beekeepers.

Research on NaCl-KCl High-Temperature Thermal Storage Composite Phase Change Material Based on Modified Blast Furnace Slag

The high-temperature composite phase change materials (HCPCMs) were prepared from solid waste blast furnace slag (BFS) and NaCl-KCl binary eutectic salt to achieve efficient and cost-effective utilization. To ensure good chemical compatibility with chlorine salt, modifier fly ash (FA) was incorporated and subjected to high-temperature treatment for the processing of industrial solid waste BFS, which possesses a complex chemical composition. The HCPCMs were synthesized through a three-step process involving static melting, solid waste modification, and mixing–cold pressing–sintering. Then, the influence of the modification method and the amount of SiC thermal conductivity reinforced material on chemical compatibility and thermodynamic performance was explored. The results demonstrate that the predominant phase of the modified solid waste is Ca2Al2SiO7, which exhibits excellent chemical compatibility with chlorine salt. HCPCMs containing less than 50 wt.% chloride content exhibit good morphological stability without any cracks, with a melting temperature of 661.76 °C and an enthalpy value of 108.73 J/g. Even after undergoing 60 thermal cycles, they maintain good chemical compatibility, with leakage rates for melting and solidification enthalpies being only 6.3% and 0.23%, respectively. The equilibrium was achieved when 40 wt.% of chloride salt was encapsulated upon the addition of 10% of SiC, and the incorporation of SiC resulted in an enhancement of thermal conductivity for HCPCMs to 2.959 W/(m·K) at room temperature and 2.400 W/(m·K) at 200 °C, with an average increase of about 2 times. The cost of the prepared HCPCMs experienced a significant reduction of 81.3%, demonstrating favorable economic performance and promising prospects for application. The research findings presented in this article can offer significant insights into the efficient utilization of solid waste.

Impact of organic carbon on heavy metals of river sediments and aquatic ecosystems: A review

AbstractOrganic carbon with variable chemical composition sourced primarily from terrestrial and aquatic biogenic input has a significant impact on sediment heavy metal mobility. The present scientific view is unclear in deciphering the role of labile organic carbon in changing sediment heavy metal concentration. The present review critically assesses the impact of various forms of carbon on different geochemically bound heavy metal fractions and their monitoring. It is evident from the review that, the biochemical form of organic carbon (based on degradability and biopolymeric forms), carbon‐geochemical association, and density of organic carbon (light or heavy carbon fractions) plays an important role in determining the bioavailability and toxicity of metals for aquatic organisms. Besides the organic carbon, various sediment conditions that define the behavior of heavy metals include pH, redox condition, sulfide concentration, salinity, temperature, etc. Therefore, it is recommended that carbon relation with heavy metal mobility and stability should be included under long‐term sediment management plans to maintain the sediment quality of the river system.

Modeling and Simulation of Single Flow Zinc–Nickel Redox Battery Coupled with Multi-Physics Fields

Metallic zinc (Zn) presents a compelling alternative to conventional electrochemical energy storage systems due to its environmentally friendly nature, abundant availability, high water compatibility, low toxicity, low electrochemical potential (−0.762 V vs. SHE), and cost-effectiveness. While considerable efforts have been devoted to enhancing the physical and chemical properties of zinc-ion battery materials to improve battery efficiency and longevity, research on multi-physics coupled modeling for a deeper understanding of battery performance remains relatively scarce. In this study, we established a comprehensive two-dimensional model for single-flow zinc–nickel redox batteries to investigate electrode reactions, current-potential behaviors, and concentration distributions, leveraging theories such as Nernst–Planck and Butler–Volmer. Additionally, we explored the distribution of the velocity field using the Brinkman theory in porous media and the Navier–Stokes equations in free-flow channels. The validated model, informed by experimental data, not only provides insights into the performance of the battery, but also offers valuable recommendations for advancing single-flow zinc–nickel battery technology. Our findings offer promising avenues for enhancing the design and performance of not only zinc–nickel flow batteries, but also applicable for other flow battery designs.

Keratin/Copper Complex Electrospun Nanofibers for Antibacterial Treatments: Property Investigation and In Vitro Response

The frontiers of antibacterial materials in the biomedical field are constantly evolving since infectious diseases are a continuous threat to human health. In this work, waste-wool-derived keratin electrospun nanofibers were blended with copper by an optimized impregnation procedure to fabricate antibacterial membranes with intrinsic biological activity, excellent degradability and good cytocompatibility. The keratin/copper complex electrospun nanofibers were multi-analytically characterized and the main differences in their physical–chemical features were related to the crosslinking effect caused by Cu2+. Indeed, copper ions modified the thermal profiles, improving the thermal stability (evaluated by differential scanning calorimetry and thermogravimetry), and changed the infrared vibrational features (determined by infrared spectroscopy) and the chemical composition (studied by an X-ray energy-dispersive spectroscopy probe and optical emission spectrometry). The copper impregnation process also affected the morphology, leading to partial nanofiber swelling, as evidenced by scanning electron microscopy analyses. Then, the membranes were successfully tested as antibacterial materials against gram-negative bacteria, Escherichia coli. Regarding cytocompatibility, in vitro assays performed with L929 cells showed good levels of cell adhesion and proliferation (XTT assay), and no significant cytotoxic effect, in comparison to bare keratin nanofibers. Given these results, the material described in this work can be suitable for use as antibiotic-free fibers for skin wound dressing or membranes for guided tissue regeneration.

Corrosion performance of different alloys exposed to HTL conditions—A screening study

AbstractThe corrosion and material evaluation study in (a) water‐based simulated black liquor and (b) water‐based simulated black liquor at super‐critical conditions was successful. The conclusion from the testing program was that the most resistant alloy for the defined conditions is the chromium‐rich carbon steel candidate P91 (UNS K91560). This is a type of creep strength‐enhanced ferritic alloy, which is steel designed to retain strength at high temperatures. The P91 abbreviation represents the material's chemical composition, that is, 9 wt% chromium (Cr) and 1 wt% molybdenum (Mo). Further work is required to conclude the corrosion resistance for the P91 quality at supercritical conditions in the welded condition and to better understand caustic corrosion mechanisms.

Effect of Recycled Concrete Aggregate Addition on the Asphalt Mixtures Performance: ITZ Area, Microstructure, and Chemical Analysis Perspectives

The importance of environmental consciousness and sustainability is increasing among transportation governing bodies worldwide. Many government bodies are concerned with maximizing the usage of recycled substances in road construction. Therefore, assessing the effect of recycled materials consumption is essential, mainly when designing new ‘green’ pavement types. The primary objective of this study is to investigate the impact of different treatments on improving the interfacial transition zone (ITZ) of coarse recycled concrete aggregate (CRCA) and its application in asphalt mixes. Such an aim is accomplished by enhancing its physical and mechanical characteristics, as well as its microstructure. The surface morphology, chemical composition, and intermix phases of the ITZ area and calcium silicate hydrate (CSH) compounds for CRCA were evaluated using scanning electron microscopy (SEM), an energy-dispersive X-ray analyzer (EDAX), and X-ray diffraction analysis (XRD). The performance of asphalt mixtures that included treated and untreated CRCA was also examined using different tests. It was found that heat treatment is an effective technique for enhancing the ITZ. However, cracks were seen in the mortar of CRCA when exposed to high temperatures (500 °C), which adversely affects the characteristics of the mortar. Acid treatment appeared to be an effective approach for improving the ITZ area. Nevertheless, the treatment that used acetic acid, a weak acid, was more effective than HCl acid, a strong acid. The outcomes revealed that the ITZ microstructure is significantly enhanced under different treatment types; however, microstructure improvements mainly included increased surface homogeneity and CSH compounds and a reduced Ca/Si ratio. It was also found that the asphalt mixtures with different proportions of untreated CRCA exhibited enhanced resistance to rutting. Furthermore, their tensile strength ratio (TSR) values were above the minimal level requirements. Moreover, the asphalt mixture with 30% CRCA, which was treated with various treatment methods, demonstrated a significant improvement in the mixtures’ mechanical properties; therefore, its application is highly successful and an environmentally friendly solution.

The Effects of Feedstock, Pyrolysis Temperature, and Residence Time on the Properties and Uses of Biochar from Broom and Gorse Wastes

Biochar (BC), which can be produced from several feedstocks, has been widely studied. However, the BC derived from highly pyrolytic shrubs, such as broom and gorse, has been less frequently used and only partially characterized. These wastes, when used for the preparation of biochar, can fix carbon and contribute to environmental conservation, helping to achieve sustainable development objectives. Eight biochars from broom and gorse were produced and fully analyzed, providing a more complete and novel description, with new insights for assessing their utilization. The aims of this study were to elucidate the effects of feedstock, pyrolysis temperature, and residence time on biochar properties and to assess the adequacy of these biochars as fuel. Elemental and proximate analyses and estimations of the lower and higher heating values were performed, and physical and chemical properties, as well as several other related energy indices, were determined. The experimental results showed that the temperature was a key factor in the properties of the biochars, while residence time was less important. The BCs obtained from the two feedstocks did not show important effects on the properties, which is consistent with the fact that they are woody legumes. These biochars had a high carbon content and were thermally stable. The BCs also had a high calorific value and suitable energetic properties. Additionally, their PAH contents were low, indicating that the use of these biochars would be safe. In conclusion, broom- and gorse-derived biochars can be considered as renewable fuels for green energy production.

Band Engineering of Perovskite Quantum Dot Solids for High-Performance Solar Cells.

CsPbI3 perovskite quantum dot (PQD) shows high potential for next-generation photovoltaics due to their tunable surface chemistry, good solution-processability and unique photophysical properties. However, the remained long-chain ligand attached to the PQD surface significantly impedes the charge carrier transport within the PQD solids, thereby predominantly influencing the charge extraction of PQD solar cells (PQDSCs). Herein, a ligand-induced energy level modulation is reported for band engineering of PQD solids to improve the charge extraction of PQDSCs. Detailed theoretical calculations and systemic experimental studies are performed to comprehensively understand the photophysical properties of the PQD solids dominated by the surface ligands of PQDs. The results reveal that 4-nitrobenzenethiol and 4-methoxybenzenethiol molecules with different dipole moments could firmly anchor to the PQD surface thoroughly the thiol group to modulate the energy levels of PQDs, and a gradient band structure within the PQD solid is subsequently realized. Consequently, the band-engineered PQDSC delivers an efficiency of up to 16.44%, which is one of the highest efficiencies of CsPbI3 PQDSCs. This work provides a feasible avenue for the band engineering of PQD solids by tuning the surface chemistry of PQDs for high-performing solar cells or other optoelectronic devices. This article is protected by copyright. All rights reserved.

Selective and sensitive MIP-Based electrochemical Sensor for the analytical determination of Lanreotide

Lanreotide (LAN) is an analog of somatostatin used to treat acromegaly and neuroendocrine tumors. Considering drug toxicity and the lack of sensitive techniques in drug analysis, the development of sensitive analytical methods is of great importance. During this research, a molecular imprinted polymer (MIP) based film [P(HEMA-MAGA)@MIP/GCE] was prepared by photopolymerization technique for electrochemical determination of LAN for the first time. N-methacryloyl-L-glutamic acid (MAGA) and hydroxyethyl methacrylate (HEMA) were used as functional and basic monomers, respectively. The surface alterations were investigated using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) and the chemical composition of the MIP-based sensor. Theelectrochemical characterization of the modifiedelectrodes was assessed using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Using differential pulse voltammetry (DPV) in standard solution and spiked serum sample of LAN, the linear response range for LAN was obtained as 1.0x10 − 14 M – 1.0x10 − 13 M. The limit of detection (LOD) values were 1.76x10 − 15 M and 1.82x10 − 15 M in water and commercial human serum, respectively. The limit of quantitation(LOQ) values for these were 5.85x10 − 15 M and 6.07x10 − 15 M, respectively. The P(HEMA-MAGA)@MIP/GCE sensor also showed excellent recovery in pharmaceutical preparation and commercial human serum form with of 99.37 % and 99.27 %, respectively, with a good RSD value (0.51–0.73), confirming the accuracy and precision of the sensor. As a control, the non-imprinted polymer (NIP) was also prepared to serve in the same way but without the template. The selectivity experiments were conducted using somatostatin (SOM) and octreotide (OC) as potential competitors to demonstrate the selectivity of the proposed sensor against LAN molecules.

Improvement of Qualitative Analyses of Aliphatic Alcohols Using Direct Catalytic Fuel Cell and Chemometric Analysis Format

Direct catalytic methanol fuel cells (DCMFCs) have been studied for several years for energy conversion. Less extensive is the investigation of their analytical properties. In this paper, we demonstrate that the behavior of both the discharge and charger curves of DCMFCs depends on the chemical composition of the solution injected in the fuel cell. Their discharge and charge curves, analyzed using a chemometric data fusion method named ComDim, enable the identification of various types of aliphatic alcohols diluted in water. The results also show that the identification of alcohols can be obtained from the first portion of the discharge and charge curves. To this end, the curves have been described by a set of features related to the slope and intercept of the initial portion of the curves. The ComDim analysis of this set of features shows that the identification of alcohols can be obtained in a time that is about thirty times shorter than the time taken to achieve steady-state voltage.

History of the use of chemical weapons for military purposes and the possibility of their current use

Throughout the history of mankind there have been many wars of both local character and large-scale wars. At the heart of military actions necessarily lies the use of weapons, one type of which is chemical. Chemical weapons, the basis of which are diverse in their effect on the body and chemical composition of poisonous substances, began to be used for military purposes during World War I, namely, the first use occurred on April 22, 1915 in Belgium near the city of Ypres. Germany used gas cylinders filled with chlorine in this attack. The man who created this weapon was German chemist Fritz Haber, who became known as the "father of chemical weapons". Since that time, scientists from different countries began to actively study the effect of poisonous substances on the human body, synthesize their new types, as well as search for reliable means of protection against its effects. Throughout history, attempts have been made to ban the use of chemical weapons. In particular, after the end of the First World War, the Geneva Protocol was adopted in 1925, prohibiting the use of asphyxiating, poisonous or other similar gases in war. However, this agreement failed to limit the use of poisonous substances, which led to their further use, mainly in localized wars. Much work on the prohibition and destruction of chemical weapons belongs to the Organization for the Prohibition of Chemical Weapons, established in 1997 after the adoption of the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on Their Destruction in 1993. The purpose of this paper is to summarize the history of chemical weapons for military purposes, as well as to study the activities for their prohibition. Literary data of recent years on the history of creation, use of chemical weapons and international legal agreements on their prohibition and destruction, the main types of toxic substances, means of protection against their effects are analyzed. Conclusions are made about the possibilities of chemical weapons use at present.

Fabrication and Properties of Bi2S3 Nanowire Thin Film Solar Cells by Spin Coating with Varying Sulfur Concentrations in the Precursor

AbstractWe conducted a simple solution-based method to fabricate Bi2S3 nanowire thin film solar cells by spin coating with varying sulfur-to-bismuth ratios. Spherical nanoparticles were observed in the thin film with low-concentration sulfur solution, with these nanoparticles gradually changing to nanorods. Finally, nanowires of Bi2S3 were observed in the thin film with a high sulfur concentration in solution. The band gap gradually decreased with the increase in sulfur concentration. The solar cell performance was significantly improved with the nanowire structure. During film fabrication, sulfur vacancy defects appeared primarily because of high annealing temperatures. These defects were somewhat reduced by the high concentration of sulfur in the solution, supported by the energy-dispersive x-ray spectroscopy (EDS) results. The elemental chemical composition of Bi2S3 material showed an increase in the sulfur-to-bismuth ratio, reaching saturation at almost 0.9. In this work, we systematically observed the effect on the optical properties, surface morphology, and photovoltaic properties by changing the concentration of sulfur in the precursor. The nanowire structure with a high concentration of sulfur in the solution is a promising way to improve the Bi2S3 thin film solar cell.

Role of buttering layer composition on microstructural heterogeneity and mechanical properties of Alloy 617 and P92 steel dissimilar welded joints for future Indian AUSC program

AbstractRestrictive operating conditions (even exceeding 700 °C) of materials in advanced ultra super critical (AUSC) power plants and the need to minimize manufacturing and maintenance costs require the production of dissimilar metal welded joints (DMW). Significant differences in the physical and chemical properties of welded materials lead to phenomena that reduce the weldability of the metals used and force the search for solutions that limit unfavorable phenomena, e.g., the use of buttering layers. The study presents a comparison of two types of joints with Alloy 617 (UNS N06617) and ferritic P92 (UNS K92460) steel made using Inconel 82 (ENiCrFe-3) and Inconel 617 (ERNiCrCoMo-1) alloys buttering layer and the corresponding chemical composition of filler metals. All areas of the joints made with the gas tungsten arc welding process were subjected to structural investigations (optical microscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) and mechanical tests (microhardness, room and high temperature tensile, and toughness testing). Despite the more complicated welding procedure, sound welded joints were obtained with favorable properties resulting, inter alia, from the reduced thickness of the martensite layer in HAZ of P92 steel and the limited diffusion of alloy components compared to welded joints without the buttering layer. This also resulted in a reduction of the maximum hardness (especially in the case of Inconel 82 buttering—by 15–30 HV0.5 in comparison with Inconel 617 buttering) and an increase in strength while limiting the decrease in plasticity (even 663 MPa tensile strength and 21% of elongation for Inconel 617 buttered joint). Moreover, improved high-temperature performance (approximately 70–100 MPa) of the welded joint following the application of the buttering layer was confirmed. The presented results allow for drawing general conclusions that both proposed welding procedures can be recommended for use in the working conditions occurring at AUSC.

Mitigation of cadmium and arsenic in rice grain by zero valent iron through modifying the soil chemical property and microbial community structure

Mitigation of cadmium and arsenic in rice grain by zero valent iron through modifying the soil chemical property and microbial community structure