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In order to improve the mechanical properties of the wear-resistant layer of the hob cutter ring in shield construction, the influence of different composite matrix powders on the comprehensive performance of the cladding layer was investigated. In this study, TiC-reinforced Fe-Ni-based cladding layers with different matrix compositions were prepared on a modified H13 steel base material using plasma cladding (PC) technology. The matrix powders included Ni-based alloy powder, iron powder Y, and iron powder R. The two iron powders were mixed in different proportions, and then an equal amount of Ni-based alloy powder and TiC ceramic particles were added to form five kinds of composite cladding layer alloy powders. The cladding layers of five different matrices were obtained by cladding. The microstructure and mechanical properties of the composite cladding layer were studied using a metallographic microscope (OM), an X-ray diffractometer (XRD), a scanning electron microscope (SEM), an energy dispersive spectrometer (EDS), an electronic universal testing machine, an image processing microhardness tester, and an abrasive belt friction and wear testing machine. The results showed that the cladding layers of different samples had good metallurgical bonding with the base material. And the microstructure gradually refined from the bottom of the cladding layer to the top of the cladding layer. The cladding layer phases were mainly composed of Fe, FeO, TiC, FeNi, and CrNi. With the increase in the iron powder R ratio, the aggregation of alloy elements gradually alleviated. The ratio of iron powder R was increased from 1/10 to 2/5, the longitudinal shear strength between the cladding layer and the matrix was increased from 318 Mpa to 333 Mpa, and the transverse shear strength was increased from 303 Mpa to 342 Mpa. The hardness of the modified wear-resistant layer was better than that of the cladding layer without iron powder R, but the hardness of the cladding layer gradually decreased. After the modification of iron powder R, the wear resistance of the cladding layer was improved to varying degrees. When Y:R was 9:1, its wear resistance was the best, and the change trend of the wear resistance was consistent with that of hardness. The wear forms of different samples were adhesive wear and abrasive wear. And the height difference of the wear surface gradually increased with the improvement in wear resistance. [ABSTRACT FROM AUTHOR]

Objective In order to avoid the problem of equipment blockage caused by sulfur deposition in the conventional natural gas wet oxidation desulfurization process, an iron-based hollow glass beads(HGB) catalyst modified by amino-phosphate difunctional group was developed for the heterogeneous catalytic oxidation regeneration of desulfurization rich liquid in the desulfurization- regeneration step-by-step scheme. Methods Infrared spectroscopy was used to characterize the structure of the catalyst. The effects of the ratio of silane coupling agent (KH-550), roasting temperature and FeCl2, 6H2. O dosage on the regeneration of desulfurization agent and desulfurization effect were investigated by static desulfurization experiments, and the reusability performance of the catalyst was explored. Results The amino-phosphoric acid modified iron-based HGB catalyst could make the desulfurization rich liquid to be effectively regenerated and remain stable in the acidic desulfurization liquid. Under the conditions of roasting temperature of 300 C for 6 h, mass ratio of HGB to KH-550 of 18 and mass ratio of HGB to FeCl2, 6H2O of 15, the iron-based HGB catalyst prepared had the best catalytic performance, and the desulfurization performance kept basically stable after 3 times of repeated regeneration of desulfurization solution. Infrared spectroscopy analysis showed that the catalyst structure remained intact. Conclusions The amino-phosphoric acid modified iron-based HGB catalyst has a good effect on desulfurization rich liquid regeneration in the field of natural gas wet oxidation desulfurization, which provides a new choice for desulfurization rich liquid regeneration at present. [ABSTRACT FROM AUTHOR]

Metallurgical solid wastes, such as metallurgical dust and mud containing iron, are formed during metallurgical sintering. They are composed of complex components and are harmful to the environment. Alongwith the current metallurgical sintering process, NOx emission control is the top priority of pollution control in the steel industry. This paper proposes a new idea of preparing doped low-temperature catalysts using metallurgical dust and mud containing iron. Herein, the metallurgical iron-containing mud was modified by acid leaching, and the products were doped with Ce and Mn by the precipitation method to prepare a new type of catalyst. The prepared Mn–Ce-doped mud-based catalyst (Mn0.05Ce0.1/ADM, the ADM represents the dust and mud from acidolysis) was characterized via X-ray diffraction, nitrogen adsorption/desorption isotherm method, scanning electron microscopy, X-ray photoelectron spectroscopy, temperature-programmed desorption of ammonia, and temperature-programmed reduction of hydrogen. The results showed that Mn0.05Ce0.1/ADM achieveda NOx removal rate of >90% within a wide temperature range from 170 ℃ to 430 ℃. Moreover, itshowed excellent SO2 and H2O resistance. A microstructural analysis revealed that the strong interaction between Fe–Ce–Mn could improve the surface acidity of the catalyst, thus increasing Lewis acid sites. Further, the active components of Mn0.05Ce0.1/ADM prepared by Ce and Mn exhibited good dispersion and an excellent mesoporous structure. In particular, Mn doping could inhibit the crystallization degree on the catalyst surface, improve the dispersed state of the active components in Mn0.05Ce0.1/ADM, and help improve the catalyst SCR (Selective Catalytic Reduction) activity. Combined with theanalysis of the factors influencing the catalyst, the results showed that the Ce–Mn doped catalyst increased the Fe3+ concentration while sacrificing a certain amount of Ce3+ and high-valent Mn+, achieving the most balanced denitration activity. Mn0.05Ce0.1/ADM formed more NO active centers by increasing the Lewis acid content to promote the generation of nitrate species and NO2. Moreover, Mn doping enhanced the Fe–Ce synergy, which makes active species (Mn–Ce–Fe) easier reduction. In particular, the increase in surface oxygen mobility could significantly improve the low-temperature activity of the catalyst. The water and sulfur resistance tests of the three catalysts (Ce0.1/ADM、Mn0.05/ADM、Mn0.05Ce0.1/ADM) showed that Mn0.05Ce0.1/ADM benefited from the excellent water and sulfur resistance of Fe and Ce. The results showed that doping Ce into ADM inhibited the adsorption of H2O molecules on the active component β-MnO2 and also the reaction of SO2 molecules with the component. The results reported herein can provide theoretical references for the high-value-added utilization of metallurgical solid wastes.

Amorphous brazing foils facilitate the brazing process due to their high flexibility. Nickel‐based amorphous brazing foils are already in industrial use. However, as the raw material price for nickel is continuously increasing, more cost‐efficient iron‐based amorphous brazing foils are currently the focus of research. In this study, three alloys in the quinary system iron‐nickel‐chrom‐silicon‐boron will be investigated, which, according to previous predictions of newly developed thermodynamic databases, should exhibit an increased glass forming ability. The production and the characterization of the new iron‐based foils will in turn serve to validate the newly developed thermodynamic databases. With one of the alloys, a new iron‐based partly amorphous brazing foil can successfully be produced, but the other two alloys are too brittle for the brazing process. The results of this study not only show that the newly developed thermodynamic database of the quinary iron‐nickel‐chrome‐silicon‐boron alloy system can provide suitable prediction on the microstructure and melting behavior of the corresponding alloys, but also that it is possible to produce a quaternary iron‐based partly amorphous foil. [ABSTRACT FROM AUTHOR]

The hot-pressing sintering experiments were carried out under the conditions of sintering temperature of 950 ℃, holding time of 5 mins and different sintering pressures. The effects of sintering pressure on the properties of three kinds of low liquid phase Fe-based pre-alloyed bit matrix and one traditional Fe-based bit matrix were compared and studied, including the hardness, the bending strength, the relative density, the diamond embedding strength of the matrix, the thermal damage of diamond. as well as the microstructure and the morphology of drill bit matrix. The results show that with the increase of sintering pressure, the indentation hardness, the bending strength and the relative density of blank matrix with low liquid phase gradually increase, but the hardness and the bending strength of traditional Fe-based pre-alloyed blank matrix increase at first and then decrease, and the relative density increases. For the matrix containing diamonds, the bending strength of low liquid phase and traditional Fe-based matrix increases with the increase of sintering pressure. When the sintering pressure is 20 MPa, the bending strength of the diamond containing matrix with low liquid phase tends to be stable, while the bending strength of the traditional Fe-based matrix containing diamond decreases slightly. At the same time, with the increase of sintering pressure, the homogeneity of the low liquid phase matrix is enhanced, but the thermal damage of the diamond is gradually aggravated. According to the analysis of the mechanical properties and the fracture morphology of the matrix, the optimal sintering pressure is 20MPa. At this time, the hardness and the bending strength of the low liquid phase Fe-based pre-alloy matrix can meet the requirements of impregnated diamond bits.

Shape memory alloys (SMA) are a class of smart materials with inherent shape memory and superelastic characteristics. Unlike other SMAs, iron-based SMAs (Fe-SMA) offer cost-effectiveness, weldability, and robust mechanical strength for the construction industry. Thus, applying these promising materials to advanced manufacturing processes is of considerable industrial and academic relevance. This study aims to present a pioneer application of a Fe–Mn–Si–Cr–Ni–V-C SMA to arc-based directed energy deposition additive manufacturing, namely wire and arc additive manufacturing (WAAM), examining the microstructure evolution and mechanical/functional response. The WAAM-fabricated Fe-SMAs presented negligible porosity and high deposition efficiency. Microstructure characterization encompassing electron microscopy and high energy synchrotron X-ray diffraction revealed that the as-deposited material is primarily composed by γ FCC phase with modest amounts of VC, ε and σ phases. Tensile and cyclic testing highlighted the Fe-SMA's excellent mechanical and functional response. Tensile testing revealed a yield strength and fracture stress of 472 and 821 MPa, respectively, with a fracture strain of 26%. After uniaxial tensile loading to fracture, the γ → ε phase transformation was clearly evidenced with post-mortem synchrotron X-ray diffraction analysis. The cyclic stability during 100 load/unloading cycles was also evaluated, showcasing the potential applicability of the fabricated material for structural applications.

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Carbon dioxide (CO 2) hydrogenation to aromatics is promising for reducing the burden of petroleum fuels. Herein, iron-based catalyst was mixed with boron modified HZSM-5 with pre-treatment and post-treatment method. The textural, acidic and element distribution properties over zeolite framework and external surface were studied. Combining with characterizations for internal and external coke, the element distribution-acidity-coke-stability relationship over boron-modified zeolite was put forward. Pre-treated zeolite witnessed reduced amount of external and total Brönsted acid sites (BAS) with similar degree, and increase paired Al (Al pair) fraction in the intersection site, leading to increased aromatics selectivity and reduced coke amount. While boron post-treatment significantly reduced external surface BAS and inhibited formation of condensed external coke. Afterwards, the mechanism of olefins aromatization was studied and found that PT-Z5-B greatly suppressed the overalkylation of light aromatics, thus alleviating the co-deactivation pattern generated by transformation of coke precursors from zeolite to iron-based catalyst. [Display omitted] • Boron pre-treatment concentrated Al pair species in intersection area. • Boron post-treatment suppressed external BAS and condensed coke. • Boron post-treatment inhibited surface deep coking of light aromatics. • Boron post-treatment enhanced oxide stability by delivering lighter coke precursors. [ABSTRACT FROM AUTHOR]

Hyperphosphatemia is a well-known complication of kidney disease. Phosphate binders are a mainstay treatment, but despite the existence of several phosphate binders, there is no one best approach to manage hyperphosphatemia. Phosphate binders are calcium-based, non-calcium-based, and others. While calcium-based phosphate binders are used frequently, they may cause hypercalcemia. Conversely, lanthanum carbonate and sevelamer were not linked to hypercalcemia but are costlier. The most recently developed class of phosphate binders is the ironbased ferric citrate and sucroferric oxyhydroxide. These have an important role in controlling phosphate levels due to their ability to lower the phosphate while concurrently providing iron sources. This review provides pharmacological profiles of different phosphate binders and their clinical usages, and further elaborates on their place in hyperphosphatemia management. [ABSTRACT FROM AUTHOR]

Fe-based magnetic metal organic framework materials （MMOFs） with high selectivity， easy separation and multiple reuse have been widely applied in wastewater treatment. Ferrous magnetic metal organic framework materials （MMOFs） have been widely used in wastewater treatment due to their high selectivity, easy separation and multiple reuse. In this paper, the main synthesis methods of iron based MMOFs in recent years, such as mixed synthesis, in situ growth， layer by layer self-assembly, buffer encapsulation and other synthesis methods, are summarized; At the same time, the application progress of iron based MMOFs materials in the fields of catalysis, such as heterogeneous catalysis, photocatalysis and adsorption， such as the adsorption treatment of heavy metals, the adsorption treatment of organic substances and the phosphate adsorption treatment of landscape water in sewage remediation is summarized; The application characteristics of several representative MMOFs materials, such as specific surface area， pore diameter, magnetic saturation strength, treated pollutants, adsorption capacity and reuse times, were compared. Finally, the future research of iron based MMOFs materials is prospected. It is believed that the research direction of MMOFs materials in the future is to improve the stability and selectivity of MMOFs, expand the application scale of MMOFs, and develop low-cost and simpler preparation methods. [ABSTRACT FROM AUTHOR]

We report on sintering, structural, morphological, electrical, and magnetic characterization of the superconducting FeSe0.88. The sample was prepared by the solid-state reaction method at 600 °C in an evacuated borosilicate tube. X-ray diffractograms revealed the formation of two not superconducting minor impurity phases, Fe7Se8 and FeSe, both with hexagonal structures. Resistivity measurement showed that the onset superconducting temperature occurs at Tconset ~ 8.6 K. Magnetic measurements were performed at high temperature and showed that the FeSe0.88 compound presents a ferromagnetic–paramagnetic phase transition at ~ 875 K. [ABSTRACT FROM AUTHOR]

This study evaluated the mid-term (12-month) biomechanical, biocompatibility, and biological performance of additive-manufactured bioabsorbable iron-based interference screws (ISs). Two bioabsorbable iron IS types—manufactured using pure iron powder (iron_IS) and using pure iron powder with 0.2 wt% tricalcium phosphate (TCP_IS)—were compared with conventional metallic IS (control) using in vitro biocompatibility and degradation analyses and an in vivo animal study. The in vitro ultimate failure strength was significantly higher for iron_IS and TCP_IS than for control ISs at 3 months post-operatively; however, the difference between groups were nonsignificant thereafter. Moreover, at 3 months after implantation, iron_IS and TCP_IS increased bone volume fraction, bone surface area fraction, and percent intersection surface; the changes thereafter were nonsignificant. Iron_IS and TCP_IS demonstrated degradation over time with increased implant surface, decreased implant volume, and structure thickness; nevertheless, the analyses of visceral organs and biochemistry demonstrated normal results, except for time-dependent iron deposition in the spleen. Therefore, compared with conventional ISs, bioabsorbable iron-based ISs exhibit higher initial mechanical strength. Although iron-based ISs demonstrate high biocompatibility 12 months after implantation, their corrosive iron products may accumulate in the spleen. Because they demonstrate mechanical superiority along with considerable absorption capability after implantation, iron-based ISs may have potential applications in implantable medical-device development in the future. [ABSTRACT FROM AUTHOR]

Enhancement of anaerobic digestion is vital for substrate solubilization and increased biogas production at a reduced cost. The use of several iron-based additives has proven effective in improving overall bio-digester performance during anaerobic digestion sludge. This study evaluates different iron-based additives for the selection of the best additive from the alternatives using a multi-attribute decision making (MADM) approach. The weights of the attributes were computed with the entropy weight technique and the ranking of the alternatives were performed using order preference by similarity to ideal solution (TOPSIS) method. Five attributes and thirteen frequently used alternatives were selected for evaluation. The result showed that additive cost and dosages were assigned the highest weight of 62.37 % and 27.46 %, respectively. Based on the performance scores of 99.15 %, 20 mg/L of Fe3O4 nanoparticles (Fe3O4 NPs-20) ranked best (number 1) among considered alternatives for enhancement of anaerobic digestion of sludge. The outcome of this evaluation agrees with previous experimental results and suggests that the choice of an effective iron-based additive should be based on its biogas enhancement potential and cost-effectiveness (low dosage requirement and low price).

To explore a new formulation system of diamond bit matrix, three kinds of Fe-based pre-alloyed powder with low liquid phase content were utilized for the matrix fabrication of impregnated diamond bit (IDB). To this end, the D-optimal mixture design method was employed for the design of the experiment scheme which contained 16 groups of samples. The samples were fabricated under the same hot pressing sintering conditions, then tests on hardness, bending strength, and relative density were conducted. The results were analyzed by regression analysis, and so were the interrelations and interactions of formula components on matrix properties. Meanwhile, the fracture surface of samples after the bending strength test was observed by SEM. It was found that FAM1020 and FAM2120 have a positive effect on the bending strength of metal matrix composite. Besides, FAM2120 has a positive effect on the hardness of the matrix, but a negative effect on the bending strength of the diamond matrix composite. The interaction among the three powders can improve the performance of the matrix. According to the result, the Fe-based pre-alloyed bit matrix with low liquid phase content can meet the requirements of the diamond bit matrix. Based on this exploration experiment, an optimal formulation is concluded as 50 wt % X1, 30 wt % X2, 20 wt % X3. [ABSTRACT FROM AUTHOR]

The effectiveness of iron-based shape memory alloy (Fe-SMA, ‘memory-steel’) reinforcements has been proven in several studies and site applications. Due to the novelty of ribbed memory-steel reinforcement bars, limited research has been performed on their application in structural engineering, however. In this study, the bond behaviour of memory-steel bars in a near-surface-mounted configuration designed for prestressed strengthening of concrete structures was investigated. Memory-steel bars were installed on concrete blocks and activated by resistive heating before being subjected to pull-out load. The effects of heating and hence prestressing, bar ductility, bond length and rigidity of the fixation were studied based on obtained prestress, crack development, slip and bar strain. During activation of the bars, a longitudinal splitting crack with insignificant crack width occured. Two failure modes were observed during subsequent external loading, including tensile rupture of the bar when less ductile material was used, or bond failure when material with higher ductility was under investigation. Initial prestressing did not result in a reduced bond capacity. Based on the differential equation of bond behaviour, an analytical calculation procedure was developed that enables prediction of bond shear stress, slip, bar strain, pull-out load, as well as the use of a non-linear material behaviour.

Many existing concrete buildings worldwide require improvement in structural integrity. Previous research has proven the effectiveness of iron-based shape memory alloy (Fe-SMA or memory-steel) reinforcements for the prestressed strengthening of structures. The unique function of the material, i.e., the so-called shape memory effect, enables cost-effectiveness and presents simple ways to prestress defective building components. Ribbed memory-steel bars have only been available recently. This study aimed to investigate their performance in a novel strengthening technique, named near-surface mounted (NSM) method. Bond experiments with short bond lengths were performed to investigate the feasibility of this configuration and to identify the effects of several design parameters including: groove dimensions, bar diameter, bar material, cover depth, mortar strength, and concrete strength. The use of a digital image correlation system enabled detailed measurements of slips, crack width, and surface strain.An analytical procedure based on the differential equation of bond behaviour was developed, which enabled the calculation of slip, strain, bond shear stress, and load capacity. The results show that ribbed memory-steel bars can be used in an NSM configuration due to high bond capacity. The cover depth, substrate strength and elastic modulus had a significant effect on the failure mode and bond capacity.

A conceptual design study of 12-T two-in-one dipole magnets is ongoing with the iron-based superconducting (IBS) technology, as a candidate option for Super Proton Proton Collider (SPPC), which is designed with a circumference of 100 km and a center-of-mass energy of 70 TeV. Compared with Nb3Sn, the IBS design is competitive because of the potential much higher performance and lower cost of IBS conductors in the future. The design study is carried out with an expected Je level of IBS in 10 years. Besides, we also expect the IBS superconductor to have much better mechanical properties compared to stress-sensitive conductors like Nb3Sn and Bi-2212 wires. The 12-T dipole magnet is designed with common-coil configuration. We have optimized the field uniformity with two different layouts of the coil ends, including the soft-way bending and the hard-way bending. We also have explored the influence of a mid-plane gap on the field uniformity. The main parameters, the coil layouts, and the optimization of the field quality are presented. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Mixed Iron oxides like perovskites and ferrites are promising materials for photocatalytic and photoelectrocatalytic processes. • Physicochemical properties affecting the photocatalytic and photoelectrocatalytic activity of iron-based semiconductors are presented. • Advantages and disadvantages of iron-based compounds for their photocatalytic and photoelectrocatalytic applications are discussed. • The latest results for photocatalytic and photoelectrocatalytic applications using iron-based semiconductors are reviewed. Abstract The increasing demand for clean renewable energy needed for sustainable industrial progress and population growth is the driving force for the scientific community to achieve a continuous development in the field of photocatalysis and photoelectrochemistry. Nanostructures and nanomaterials have contributed significantly to the field of renewable energy due to their new physicochemical properties. Iron-based nanostructures have considerable advantages like small band gaps, allowing to harvest photons in the visible region of the solar spectrum, abundance, and important physical properties like magnetism and ferroelectricity. But they also have many shortcomings and drawbacks related to stability in the different photocatalytic media, low surface area, conductivity, and fast charge carrier recombination. In this review, the focus is placed on important members of the iron-based photocatalyst family such as, hematite, iron oxy-hydroxide, iron-based perovskites, and spinel ferrites. Also, iron doped titanium dioxide as visible light photocatalysts is covered. Various strategies employed for enhancing the photocatalytic and photoelectrocatalytic performance are discussed. Doping, oxygen vacancies, induced defects and formation of solid solutions seem to be a working strategy to address some of the challenges in photocatalysis and photoelectrocatalysis. Finally, photocatalytic and photoelectrocatalytic applications employing iron-based semiconductors are presented. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis of FeS 2 /α-Fe 2 O 3 loaded graphene foam (GF) composites via a facile route. • This combination demonstrates amazing electrochemical water splitting capabilities. • Under 1.0 M KCl, the FeS 2 /α-Fe 2 O 3 @11 %GF electrode exhibits HER performance at an overpotential of 0.17 V at 10 mA cm−2. • It also exhibits OER at a potential of 0.18 mV at 10 mA cm−2. • It exhibits an overall water splitting at a potential of 1.63 V at 10 mA cm−2. Using nonprecious metal catalysts to efficiently produce large capacities of H 2 and O 2 from water splitting through the photoelectrolysis path is a crucial objective. The FeS 2 /α-Fe 2 O 3 composite is first synthesized using thiourea under hydrothermal conditions and is subsequently combined with different weight ratios of graphene foam (GF; 6–20 %). The catalyst FeS 2 /α-Fe 2 O 3 @11 %GF demonstrates the highest photoelectrochemical water splitting activity at an excessive potential of 0.17 V, accomplishing a current density of 10 mA cm−2 and a C dl of 2.14 mF cm−2 for HER, exceeding Pt/C results (0.53 V, 2.0 mF cm−2). OER, on the other hand, exhibits an overpotential of 0.18 V at 10 mA cm−2 and a low Tafel slope value of 77.9 mV dec−1, causing a very considerable rise in the reaction kinetics with a noticeably stable behavior. Total water splitting was achieved using the FeS 2 /α-Fe 2 O 3 @11 %GF || FeS 2 /α-Fe 2 O 3 @11 %GF electrolyzer with a small cell voltage of 1.63 V to produce 10 mA cm−2. Due to the significant interfacial effects produced by the well-integrated GF, boosted pore volume and surface area, abundance of accessible sites of activity, and growing Fe2+/Fe3+ ratio, which significantly improved electron transfer and electrolyte transport, the three-component system improved its ability to achieve efficient water splitting. [ABSTRACT FROM AUTHOR]

Iron-based PAA activation process is a promising advanced oxidation process for water decontamination which depends on Fe(II) as the main reactive site for PAA activation, resulting in various reactive oxidative species (ROSs) generation. For practical application, the impact of water matrix chloride ion (Cl−) on ROSs production and contaminants removal should be carefully considered. In this study, it's found that the introduction of Cl− (0.1–10 mM) could significantly enhance the reaction rate of the rapid stage (k obs1) up to 2.15 times at the initial pH of 4.25 in the Fe(II)/PAA system. Further studies demonstrated that the improved removal capacity of NAP resulted from Cl− induced R-O• generation as indicated by the exposure dose of R-O• increasing from 7.74 × 10−11 M•s to 1.44 × 10−10 M•s, rather than chlorine-containing radicals' generation. DFT calculation results suggested that the formed Fe(II)-Cl− complexes could easily activate PAA to generate more ROSs for NAP removal. Moreover, Fe(II)/PAA treatment can alleviate the biological toxicity of pollutants via both the Escherichia coli test and toxicity assessment. The obtained new knowledge manifested that Cl− can boost ROSs generation and conversion in iron-based PAA systems, providing guidance for the efficient decontamination of chlorine-containing sewage with PAA-based AOPs. [Display omitted] • The presence of Cl− promotes NAP removal in the Fe(II)/PAA system at pH 3.0–9.0. • Cl− accelerates PAA depletion due to the formation of complex ([FeCl(H 2 O) 5 ]+ or [FeCl(OH)(H 2 O) 4 ]). • Cl− induced R-O• generation to become the dominant ROS in Fe(II)/PAA system. • Fe(II)/PAA/Cl− treatment can reduce the biological toxicity of wastewater. [ABSTRACT FROM AUTHOR]

The slag-free self-shielded flux-cored wire with simultaneous addition of ferroniobium (Fe-Nb) and ferrotitanium (Fe-Ti) was developed to fabricate the iron-based hardfacing alloys. The transfer coefficients of Nb and titanium of slag-free self-shielded flux-cored wire were 91.2 and 63.8%, respectively. The changes in microstructures indicate that Nb and Ti addition shifted the carbon concentration in the remaining liquid to one corresponding to the near eutectic state owing to the formation of (Nb, Ti)C which consumed carbon. The wear loss of the hardfacing alloy with 18 wt-% Fe-Nb and 6 wt-% Fe-Ti addition was the smallest among all the alloys owing to the formation of reinforced uniform quadrangle-shaped (Nb, Ti)C carbides in the refined microstructure and the highest hardness. [ABSTRACT FROM AUTHOR]

Iron-based CO2 catalysts have shown promise as a viable route to the production of olefins from CO2 and H2 gas. However, these catalysts can suffer from low conversion and high methane selectivity, as well as being particularly vulnerable to water produced during the reaction. In an effort to improve both the activity and durability of iron-based catalysts on an alumina support, copper (10-30%) has been added to the catalyst matrix. In this paper, the effects of copper addition on the catalyst activity and morphology are examined. The addition of 10% copper significantly increases the CO2 conversion, and decreases methane and carbon monoxide selectivity, without significantly altering the crystallinity and structure of the catalyst itself. The FeCu/K catalysts form an inverse spinel crystal phase that is independent of copper content and a metallic phase that increases in abundance with copper loading (>10% Cu). At higher loadings, copper separates from the iron oxide phase and produces metallic copper as shown by SEM-EDS. An addition of copper appears to increase the rate of the Fischer--Tropsch reaction step, as shown by modeling of the chemical kinetics and the inter- and intra-particle transport of mass and energy. [ABSTRACT FROM AUTHOR]

In recent years, antibiotic residues are commonly detected in a variety of water bodies, causing serious threat to water ecosystems and human health. The removal of antibiotic contaminants from water based on the advanced oxidation process of activated persulfate has become a hot research topic due to its strong oxidative properties, high selectivity, and wide pH applicability range. Iron-based bimetallic materials with low cost, high stability, and excellent catalytic performance can effectively activate persulfate, which makes up for the defects of being a single iron activator, such as easy deactivation, low efficiency, and producing secondary pollution easily. Three typical Fe-based bimetallic catalysts, namely spinel ferrite, Fe-based layered double hydroxides, and Fe-based Prussian blue analogues, were investigated and analyzed for their activation of persulfate for antibiotic degradation. Several intrinsic mechanisms of persulfate activation by Fe-based bimetallic catalysts are systematically discussed, including the generation of free radicals, singlet oxygen, and high-valent metals; the process of electron transfer; and the direct oxidation process of persulfate. Finally, the general degradation pathways of four typical antibiotics, including fluoroquinolones, sulfonamides, tetracyclines, and β -lactam antibiotics, are summarized to act as a reference for future studies on the application of Fe-based bimetallic catalysts and their modifications, derivatives, and complexes in the activating technology of persulfate.

Iron-based nanoparticles prepared by precipitation from solid solution of saturated binary Cu-Fe alloy were studied by transmission electron microscopy, high-energy X-ray diffraction and Mössbauer spectroscopy. The results showed that the investigated as-prepared nanoparticles contained two phases. The major phase was determined as α− F e and the minor phase as γ− F e O . Furthermore, additionally annealed samples in Ar protective atmosphere were investigated. Results showed clear decrease in contribution of α− F e phase and also revealed the presence of various iron oxides (maghemite, magnetite, hematite and wűstite). [ABSTRACT FROM AUTHOR]

The new kind of iron-based superconductor FeSe which has being widely studied recently is arsenic-free and has about 8 K of Tc. The less poisonous and simple binary FeSe is interesting for both scientific studies and engineering applications, even though its Tc is lower than that of other iron-based compounds. Recently, the single crystal and thin film technology of FeSe has been studied to realize the anisotropic property. In our study, the highly preferred orientation poly-crystal was grown by the Bridgman method. The vacuum condition during growth affects the porosity of FeSe. It is difficult to produce high density under 1 atmosphere even when maintained at high temperature for a long time. When the pressure is controlled at less than 10^-1\ torr, ultra low porosity (and high density) crystal can be grown. Polarized optical microscope images show the single crystal domain up to about 5 mm with (110) preferred orientation by XRD analysis. A XRD peak shift is observed between samples grown by furnace-cooling and the Bridgman method, which is supposed to be due to residual stress during growth. It also induced a Tc decrease to 5.9 K in the Bridgman sample, but recovered to 6.8 K after annealing. From the microstructure, considerable columnar precipitation is observed in the Bridgman sample, which is identified as iron-rich phase by energy dispersive spectrum (EDS) analysis. [ABSTRACT FROM AUTHOR]

Abstract: The crystal structure and physical properties of BaFe2As2, BaCo2As2, and BaNi2As2 single crystals are surveyed. BaFe2As2 gives a magnetic and structural transition at T N =132(1)K, BaCo2As2 is a paramagnetic metal, while BaNi2As2 has a structural phase transition at T 0 =131K, followed by superconductivity below T c =0.69K. The bulk superconductivity in Co-doped BaFe2As2 below T c =22K is demonstrated by resistivity, magnetic susceptibility, and specific heat data. In contrast to the cuprates, the Fe-based system appears to tolerate considerable disorder in the transition metal layers. First principles calculations for BaFe1.84Co0.16As2 indicate the inter-band scattering due to Co is weak. [Copyright &y& Elsevier]

The article discusses a study which examines improvement in the shape memory effect of Fe-based alloys by different aspects of training. The different aspects of training are the number of cycles, the amount of deformation and the annealing temperature. The recovery annealing temperature is important for obtaining a good shape memory, especially during training.

An iron-based amorphous metal with good corrosion resistance and a high absorption cross section for thermal neutrons has been developed and is reported here. This amorphous alloy has the approximate formula Fe49.7Cr17.7Mn1.91Vlo7.4W1.6B15.2C3.8Si2.4 and is known as and is known as SAM2X5. Chromium, molybdenum, and tungsten were added to provide corrosion resistance, while boron was added to promote glass formation and the absorption of thermal neutrons. Since this amorphous metal has a higher boron content than conventional borated stainless steels, it provides the nuclear engineer with design advantages for criticality control structures with enhanced safety. While melt-spun ribbons with limited practical applications were initially produced, large quantities (several tons) of gas-atomized powder have now been produced on an industrial scale, and applied as thermal-spray coatings on prototypical half-scale spent-nuclear-fuel containers and neutron-absorbing baskets. These prototypes and other SAM2X5 samples have undergone a variety of corrosion testing, including both salt-fog and long-term immersion testing. Modes and rates of corrosion have been determined in various relevant environments and are reported here. While these coatings have less corrosion resistance than melt-spun ribbons and optimized coatings produced in the laboratory, substantial corrosion resistance has been achieved. [ABSTRACT FROM AUTHOR]

This study evaluated the biocompatibility and biological performance of novel additive-manufactured bioabsorbable iron-based porous suture anchors (iron_SAs). Two types of bioabsorbable iron_SAs, with double- and triple-helical structures (iron_SA_2_helix and iron_SA_3_helix, respectively), were compared with the synthetic polymer-based bioabsorbable suture anchor (polymer_SAs). An in vitro mechanical test, MTT assay, and scanning electron microscope (SEM) analysis were performed. An in vivo animal study was also performed. The three types of suture anchors were randomly implanted in the outer cortex of the lateral femoral condyle. The ultimate in vitro pullout strength of the iron_SA_3_helix group was significantly higher than the iron_SA_2_helix and polymer_SA groups. The MTT assay findings demonstrated no significant cytotoxicity, and the SEM analysis showed cells attachment on implant surface. The ultimate failure load of the iron_SA_3_helix group was significantly higher than that of the polymer_SA group. The micro-CT analysis indicated the iron_SA_3_helix group showed a higher bone volume fraction (BV/TV) after surgery. Moreover, both iron SAs underwent degradation with time. Iron_SAs with triple-helical threads and a porous structure demonstrated better mechanical strength and high biocompatibility after short-term implantation. The combined advantages of the mechanical superiority of the iron metal and the possibility of absorption after implantation make the iron_SA a suitable candidate for further development. [ABSTRACT FROM AUTHOR]

During chemical looping process, the presence of H 2 O has great effect on oxygen transfer and hydrogen generation process, thus making the reaction become more complicated. In this study, Fe 2 O 3 was chosen as the original oxygen carrier and its oxygen carrying capacity and reactivity under different H 2 O/CO molar ratios were systematically investigated. The chemical compositions of reacted iron-based oxides were measured by Mössbauer spectroscopy. According to Mössbauer spectroscopy results and product gas analysis, the paper gave further insight into the impact of H 2 O on oxygen carrying property and catalyzed effect of iron-based oxides. The results indicated that: (i) The oxygen carrying capacity of Fe 2 O 3 decreased from 45.93% to 11.33% (the theoretical maximum to be 100%) when the H 2 O/CO ratio varied from 0:1 to 2:1. (ii) The maximum CO 2 conversion rate, which reflects the reduction reactivity, was closely related to H 2 O/CO ratio and achieved the maximum (4.83%/min) at a H 2 O/CO ratio of 1:1. (iii) The presence of H 2 O could promote the reduction process of Fe 2 O 3 to generate Fe 3 O 4. (iv) Both Fe 3 O 4 and FeO which existed as reduction states of iron oxides had ability to promote the water-gas shift reaction during oxygen transfer process. • H 2 O will decrease the oxygen carrying capacity of Fe 2 O 3. • H 2 O can promote the reduction reaction of Fe 2 O 3 to Fe 3 O 4. • H 2 O will hinder the further reduction of Fe 3 O 4 and FeO. • Both Fe 3 O 4 and FeO produced during reduction reaction can improve the WGS reaction. [ABSTRACT FROM AUTHOR]

The profitability of biogas industries largely depends on substrate biodegradability. Most of the substrates for sustainable energy recovery via anaerobic digestion like lignocellulosic materials contains complex polymeric substances and requires some enhancements to achieve optimum biodegradability. Previous studies have reported that the use of iron additives improved both degradability of such substrates and biogas yield, but iron-based enhancements have shown variability in the input and yield results. This evidence-based study used meta-analysis in determining the performances of iron-based additives on biogas yield. Previously published articles on the subject were systematically identified and compiled based on set inclusion criteria. The database was used to analyze the influence of iron-based additives on the enhancement of biogas yield during anaerobic digestion of organic wastes. The pooled effect estimates at 95% confidence interval was generated with the use of Random-effects model. The overall result of the meta-analysis performed showed that iron-based additives supplementation significantly enhanced biogas yield at Standard mean difference = 1.451, 95% CI: 1.280–1.622, p < 0.001. Restricted subgroup analysis indicated that all the moderators had a significant influence on biogas yield of iron-based treated anaerobic digestion processes at p < 0.001. Evidence of heterogeneity was observed, while meta-regression analysis indicated that most of the sources of heterogeneity were explained by the additive-types, substrate-types, dosage range and research location at p < 0.05. The result of this study showed the potential of iron-based additives supplementation to improve biogas yield during anaerobic digestion of organic wastes. The information from this study avails important suggestions on policy advancements and sustainable usage of iron-based enhanced anaerobic digestion processes in biogas industries. Image 1 • Meta-analysis of iron-based additive influence on biogas yield was evaluated. • Iron supplementation in anaerobic digestion had overall positive impact on biogas yield. • All studied covariates significantly enhanced biogas yield of iron-based treated AD process. • Optimized iron-enhanced AD process can achieve higher biogas yield in industries. [ABSTRACT FROM AUTHOR]

• Novel FeSCA cathode simultaneously improves the formation of surface FeII and HO. • The selectivity of 2e− ORR of FeCA electrode was increased by 200 % via S-doping. • 73 % and 29 % of FeⅡ respectively in FeSCA and FeCA was regenerated in EF process. • As high as 99 % DMP and 3-CP removal was achieved in 240 min by FeSCA cathode. • FeSCA cathode exhibited high recyclability and stability for wastewater treatment. The regeneration of surface FeII and the electro-formation of H 2 O 2 play crucial roles for determining the degradation efficiency of heterogeneous electro-Fenton process. The sulfide iron-based carbon aerogel was synthesized directly as cathode. The main composition of iron compounds were Fe 3 O 4 and FeS∙FeS 2 , which were embedded in the matrix of carbon aerogels. Most of sulfur was evenly distributed on carbon, favoring the formation of −COOH groups. The nature of existed sulfur were investigated by temperature-programmed reaction spectroscopy respectively under the CO 2 and air. The S-doping promoted the regeneration of FeII and improved the selectivity of 2e− oxygen reduction with iron-based carbon materials. As high as 99 % removal of dimethyl phthalate and 3-chlorophenol were obtained in 240 min. Meanwhile, the EPR results demonstrated that HO∙ was formed by on site decomposing H 2 O 2 with FeSCA, which exhibited high stability with low Fe leaching (< 2 ppm) and high recyclability even in acidic medium. [ABSTRACT FROM AUTHOR]