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This response mainly deals with the scientific description of the comments on the structure of the published compound (Bi 1/2 K 1/2)(Fe 1/2 W 1/2)O 3. The newly designed (Bi 1/2 K 1/2)(Fe 1/2 W 1/2)O 3 compound was prepared using the solid-state reaction method. The ingredients were taken to satisfy the required stoichiometry/chemical composition to form a single-phase compound. The lattice parameters and structure is strongly affected by K and W doped elements. The structural analysis is supported by the results of other experimental techniques (dielectric study, Raman characterization, Hysteresis loop, etc.). [ABSTRACT FROM AUTHOR]

Electro thermal papers have been widely applied in people's daily life. Compared to traditional metal alloy resistance heaters, three dimensional graphene/carbonized-PAN composite freestanding paper with lightweight, good flexibility and excellent electrothermal performance is presented. It retains intrinsic properties of graphene sheets in the bulk state, and exhibits fast electrothermal response under low operation voltage with robust mechanical property. The fastest specific heating rate could be up to 213 °C s−1 V−1, and the highest T s is 235 °C at low driving voltage just of 1.75 V, which far surpasses those of previous carbon-based film heaters, commercial nichrome wire, and Kanthal wire. These outstanding properties together with the advantage of facile and large-scale fabrication, make the composite paper with great potential applications in flexible electronics. Image 1 [ABSTRACT FROM AUTHOR]

A Ru-Ni@Cu alloy catalyst with a well-connected two-phase or three-phase contact interface is fabricated as an alternative to a Pt-based catalyst for the hydrogen evolution reaction (HER) in water electrolysis in this study. For optimum bonding and adhesion stability, the alloy particles are grown directly on carbon paper (CP) by the hydrothermal method. The alloy particles are composed of central Cu cores, Ni nests wrapped around Cu core, and small (2.0 nm) Ru nanoparticles embedded at the Ni nests. The Ni surface readily adsorbs water, the high conductivity of Cu increases the electron density of the electrode surface to facilitate water splitting, and the Ru surface adsorbs more H+ ions, thus promoting hydrogen production in the Ru-Ni@Cu alloy. Eventually, despite the use of only 1.0 wt% Ru, the 1% Ru-Ni@Cu/CP electrode exhibits a low overpotential of −0.15 V (η = 246 mV and 87.08 mV dec−1) at 100 mA cm−2 in a 1.0 M KOH electrolyte, similarly to the −0.1 V overpotential of the 100% Pt/CP electrode. The electrode maintains excellent catalytic activity without deterioration for 10 days with a Faraday efficiency of 96.89% (50 h) HER and 3000th LSV cycles. [Display omitted] • Ru-Ni@Cu alloy with three-phase interface grown directly onto CP. • Cu core in the center, Ni nest on the outside, and 2.0 nm-sized Ru particle between Cu and Ni. • Hydrogen production promoted by more H+ ions adsorption on the Ru surface. • A low overpotential of −0.15 V even though only 1.0 wt.-% Ru usage. • Faraday efficiency of 96.89% for 3000 min-HER, without catalytic deactivation for 10 days. [ABSTRACT FROM AUTHOR]

Facile fabrication of flexible substrates containing high concentration of nanoparticles (NPs) is very promising owing to their capability of swab-based surface-enhanced Raman scattering (SERS) trace detection. However, the background signal of the substrate could compromise the trace-detection capabilities. Moreover, the presence of fluorescent molecules may result in intense fluorescence background which could overshadow the Raman peaks. Herein, we demonstrate that the surfactant-free bimetallic (Ag and Au) NPs, synthesized directly on the filter paper, are very effective in reducing the background signal in SERS-based trace detection. Simple soaking of filter paper in a mixture of HAuCl 4 and AgNO 3 solution, and its immediate drying and reduction produces Au-Ag alloy NPs on the filter paper. Interestingly, the substrates are very effective in quenching the background fluorescence of both filter paper and the analyte, thereby effectively detecting the SERS signature of the fluorescent molecules. In particular, Rhodamine6G (R6G) concentrations down to 10−10 M were detected under resonance excitation, both by solution drying and swabbing. The swab detection of ammonium nitrate, which is usually used in homemade explosives, was also demonstrated. Moreover, owing to the fluorescence quenching properties, the Au-Ag alloy substrates (AuAgS) were able to carry out the swab-based multiplex-detection of crystal violet (CV), Brilliant Cresyl Blue (BCB), and R6G upon resonance excitation of R6G. Finally, the substrates have shown good reproducibility, stability, and signal uniformity. This verifies the potential of AuAgS for real-world trace-detection applications. [ABSTRACT FROM AUTHOR]

Nanoalloy shows significant advantages and broad application prospects in chemical catalysis, due to the possessed high specific surface energy and abundant active sites can greatly promote their catalytic performance. In this work, morphology-controlled Cu-Sn alloy nanosheet arrays supported on carbon fiber paper (CP) substrate (Cu-Sn/CP) have been developed by a facile one-step electrodeposition technique at room temperature for the first time. Benefiting from the large active surface area, considerable ion transport channels and strong synergistic catalytic effect between Cu and Sn, the as-prepared Cu-Sn/CP served as a self-supported electrode for efficient nonenzymatic glucose sensing. Under optimized conditions, Cu-Sn/CP electrode offers wide linear ranges of 0.0005–2.0 mM and 2.0–10.0 mM, respectively. The detection limit is as low as 0.061 μM (S/N = 3). Cu-Sn/CP electrode also exhibited excellent selectivity and stability. Additionally, the proposed sensor is proven to be suitable for the detection of glucose in human serum samples. [Display omitted] • Morphology-controlled Cu-Sn/CP was first synthesized by a cost-efficient one step electrodeposition strategy. • Non-precious Cu-Sn alloy nanosheets were used for the electrocatalytic oxidation of glucose for the first time. • Cu-Sn/CP showed high electrocatalytic activity for glucose oxidation with wide linear range and low detection limit. • The as-proposed biosensor exhibited excellent anti-interference ability and stability. [ABSTRACT FROM AUTHOR]

It is shown that the composition of the investigated alloy is nearly identical to the commercially available alloy MP35N (35Co-35Ni-20Cr-10Mo, wt%). However, the thermomechanical treatment of the experimental alloy is quite different from that used for the commercial one which consists of using cold work followed by annealing at temperatures below the recrystallization temperature. Here, depending on the amouunt of cold work, a tremendous hardening effect occurs, due to Suzuki hardening which allows to tune the mechanical properties in a range much larger than obtainable by the strategy used by the High Entropy Community by creating hierarchical microstructures. [ABSTRACT FROM AUTHOR]

Friction and wear are two critical tribological factors that instigate unavoidable failures of moving components in the mechanical system. Additionally, these factors have a huge impact on global energy consumption, economy, and CO 2 emissions. Minimization of friction and wear in mechanical systems is rather challenging, however, significant advancement has been achieved in the development of new techniques to mitigate these tribological issues. Surface coating is one of the most commonly used techniques to reduce/eliminate tribological failures. Though a wide range of hard and anti-wear coating materials (metallic alloys, carbon, metallic glasses, polymers, ceramics, and composites) have been developed in the last few decades, however, ceramic coatings have always been a prime interest to researchers owing to their outstanding hardness, wear resistance, corrosion resistance, and damping capacity. Specifically, nitride ceramic coatings have been passed a long journey as hard and wear-resistance protective coatings in multiple industries such as manufacturing, automobile, aerospace, etc. This article reviews the journey of the development of nitride coatings for tribological applications. These developments include first-, second-, and third-generation nitride ceramic coatings, which include binary, ternary, multi-elemental as well as multi-layered coating compositions. This review paper sheds light on the available literature, merits, demerits, and applications of all nitride ceramics coatings for tribological applications. Recently, an innovation in nitride ceramic coatings has been reported, which is the utilization of the high entropy concept in these coatings, which has been reported to improve their tribological properties tremendously. This review paper also delivers a comprehensive review of high-entropy nitride ceramic coatings (both equimolar and non-equimolar compositions) for tribological applications, which is the latest and hot topic for researchers working on ceramics coatings and tribology. At last, this review paper identifies the gaps and provides the future possibilities of research in this area. [ABSTRACT FROM AUTHOR]

• Multianalytical study of a Moche funerary mask. • ED-XRF characterization of the metal alloy with Monte Carlo simulation. • Characterization of adhesive material and its components belonging to Moche culture. • Py-GC/MS and GC/MS were used for the chemical characterization of adhesive material. • SEM-EDS and ATR-FTIR were applied to characterize inorganic filler. The aim of this paper is to characterize materials belonging to one of the masks coming from the Lord of Ucupe's tomb in the region of Lambayeque in Peru. The mask belongs to the Moche culture which lived in the north of Peru since 100 CE. Along with the study of the extraordinary metal alloy technique using X-ray fluorescence (ED XRF) integrated with the Monte Carlo simulation, this paper investigates the blackish material used as an adhesive for its inlaid eyes. This material was analysed through the ATR FT-IR and characterized through Py-GC/MS and GC/MS for the organic components and SEM-EDS for the inorganic components. The chemical characterization of the adhesive material coming from this type of artefact, based on our knowledge of current literature, is the first on this material and allows us to take a further step into the understanding of the constituents used for this purpose. [Display omitted] [ABSTRACT FROM AUTHOR]

We introduced a strategic "Kinetic Diffusion Multiple" (KDM) that undergoes interdiffusion annealing followed by realistic thermal treatment. The blended spectra of phases and microstructures subjected to treatment in deeply grooved composition gradients enables the microstructure and micromechanical properties of structural materials to be surveyed by high-spatially resolved micro-analysis along the composition arrays. The KDM was demonstrated as a robust high-throughput methodology that enables rapid screening of the composition-microstructure-micromechanical/properties relationships for different metallic materials. It has also proven great success at elucidating the lasting effects of alloying elements and diffusion flux on microstructure, micromechanical properties, phase transformation, and their interrelationships as a whole. [ABSTRACT FROM AUTHOR]

The increasing demands for portable, wearable, and implantable sensing devices have stimulated growing interest in innovative electrode materials. In this work, we have demonstrated that printing a conductive ink formulated by blending three-dimensional (3D) porous graphene–carbon nanotube (CNT) assembly with ionic liquid (IL) on two-dimensional (2D) graphene paper (GP), leads to a freestanding GP supported graphene–CNT–IL nanocomposite (graphene–CNT–IL/GP). The incorporation of highly conductive CNTs into graphene assembly effectively increases its surface area and improves its electrical and mechanical properties. The graphene–CNT–IL/GP, as freestanding and flexible substrates, allows for efficient loading of PtAu alloy nanoparticles by means of ultrasonic-electrochemical deposition. Owing to the synergistic effect of PtAu alloy nanoparticles, 3D porous graphene–CNT scaffold, IL binder and 2D flexible GP substrate, the resultant lightweight nanohybrid paper electrode exhibits excellent sensing performances in nonenzymatic electrochemical detection of glucose in terms of sensitivity, selectivity, reproducibility and mechanical properties. [ABSTRACT FROM AUTHOR]

The design and fabrication of active and stable nanostructured electrocatalysts for hydrogen production from the electrochemical water splitting is one of the most important strategies for economical hydrogen production and replacement fossil fuels. Using of Ni-based nanostructured alloy electrodes, synthesized via electrodeposition method, due to having a high active surface area, being binder-free, and also the synergistic effect between the alloy elements, can significantly reduce the energy consumption during hydrogen production. Due to the importance of alloy electrodes and the lack of a comprehensive review in this field, in this review article, at first, the advantages and brief mechanism of the electrodeposition method for the synthesis of nanostructured electrodes are given, and then the types of alloy systems and the resulting morphologies are reviewed. Finally, recent developments in the field of alloy systems for hydrogen production are summarized. Moreover, various methods of creating different alloy nanostructures with electrodeposition method are also described in this article. The purpose of this article is to create a deep understanding of the application of alloy nanostructures and to provide a guide for the synthesis of active and stable electrodes for hydrogen production. In addition, using this review paper, one can able to select appropriate alloy system for reaching the best electrocatalytic properties. • Different modes of electrodeposition mechanisms was reviewed. • Electrodeposited metallic nanostructures have favorable electrocatalytic activity. • Various morphologies can be fabricated via electrodeposition process. • Advantages of electrodeposition process over other methods was highlighted. [ABSTRACT FROM AUTHOR]

• Analyzed the stochastic resonance and stochastic P-bifurcation of an axially moving shape-memory alloy laminate. • A change in the volume fraction of the SMA shifted the formant of the SNR (signal-to-noise ratio) curve up and down. • Variation in axial velocity, temperature, and stochastic intensity induced stochastic P-bifurcation. This paper investigates the transverse vibration of an axially moving shape-memory alloy (SMA) fiber hybrid laminations under the combined action of transverse harmonic excitation and stochastic disturbance. Considering the shape memory alloy (SMA) fiber volume fraction random field, the kinetic energy and strain potential energy of SMA laminates are solved, and the axial motion equation of SMA laminates is derived according to Hamilton principle, a non-dimensional differential equation of the transverse vibration of the axially moving SMA laminated plates is obtained by adopting the Galerkin integral method. Considering the volume-fraction stochastic field, the stochastic natural vibration of a SMA laminate is analyzed. Considering the stochastic resonance of the SMA laminate under the action of Gaussian white noise and harmonic excitation, the effects of geometric parameters, physical parameters of materials, and temperature on the stochastic resonance behavior of the SMA laminate is analyzed. Finally, the effect of the stochastic P-bifurcation phenomenon of the parameters on the steady-state response of the SMA laminate is analyzed. [ABSTRACT FROM AUTHOR]

In this paper, the "flash brazing" of SiC is successfully achieved using FeCoCrNiCu alloy in air for seconds at an ultra-low furnace temperature of 400 ℃. The interface temperature reaches over 1000 ℃ in 1 s at an ultra-fast rate via the electric field assistance. The reaction layer of the joint consists mainly of Cr 23 C 6 and the silicides of Fe, Co, Ni, and Cu. With the increase of brazing holding time, Cu gradually precipitates from the alloy, and the shear strength of the joints first increases and then decreases. The maximum strength value is 80 MPa at the test temperature of 800 ℃. This approach could help significantly improve the efficiency of ceramic bonding and achieve low-temperature joining for high-temperature applications. [ABSTRACT FROM AUTHOR]

• The bimetallic NiAu alloy dendrites were electrodeposited with a template free method. • The deposited NiAu on carbon papers can be used as disposable glucose sensors. • The as prepared NiAu alloy dendrites showed superior glucose sensing performance. • Enhanced performance may be due to dendrite structures and synergistic effects of Ni and Au. The bimetallic NiAu alloy dendrites were directly grown on the carbon papers using template free electrodeposition approaches, which demonstrated superior non-enzymatic glucose sensing performance. The enhanced electrochemical performance may be due to the dendrite structure and the low charge transfer resistance originating from the synergistic effect of Ni and Au. [ABSTRACT FROM AUTHOR]

My comments concern the significant errors in the crystallographic part of the commented paper. [ABSTRACT FROM AUTHOR]

My comments concern the sever error in the crystallographic part of the commented paper. It was found that the studied crystal is of the sillenite type and the correct formula should be Bi 25 FeO 39 :Cd,Ti instead of some kind of solid solution based on BiFeO 3. Moreover, the type of unit cell is not correct. Due to the double doping the new type of unit cell, previously unknown, was proposed for such crystals. The actual chemical composition of the studied crystals is not known. [ABSTRACT FROM AUTHOR]

My comments concern the significant error in the crystallographic part of the commented paper. It was discovered that the studied crystals are of sillenite type and the correct formula should be Bi 25 FeO 39 :Ni,Ti instead of BiFeO 3. Moreover, the type of unit cell is not correct. Due to the doping the new type of unit cell, previously unknown, was proposed for such crystals. It was found that the studied sample contains two slightly different phases of the sillenite type. The actual chemical composition of the studied crystals is not known. [ABSTRACT FROM AUTHOR]

The full-carbon/ceramic brake pair is designed to meet the increased demands for reliable braking at high speeds, heavy loads and complex service environments for vehicle and power machinery. In this paper, braking performance of different Fe–Si modified C/C–SiC composites have been studied using laboratory scale dynamometer. The phase composition/microstructure and mechanical properties of the material were studied. By mating with C/C–SiC brake disc, the effect of Fe–Si alloy modification on the friction and wear performance of full carbon/ceramic brake pair was investigated. The results indicated that the Fe–Si modification can effectively improve the wear resistance of both C/C–SiC disc and pads, and the disc/pads will have the least amount of wear only when the appropriate type of Fe–Si alloy and the suitable amount of Fe–Si alloy phase are introduced. When FeSi75 was used as the fusion infiltration material, the wear of disc/pad was 115.4 and 13.3 mm, respectively. Compared to the unmodified C/C–SiC disc/pad, the wear of Fe–Si modification disc/pad was reduced by 72.7 % and 87.2 %, respectively. [ABSTRACT FROM AUTHOR]

The National Aeronautics and Space Administration (NASA) has been involved in the development and maturation of metal additive manufacturing (AM) for space applications since the late 2000's. Several efforts have focused on the understanding of AM processes through material characterization and testing, standards development, component fabrication, and infusion into propulsion development and flight applications. NASA matured commonly used aerospace alloys from various alloy families (Nickel, Copper, Stainless and Steel, Aluminum, and Titanium-based) through detailed AM process and heat treatment characterization, in addition to mechanical and thermophysical testing. While these alloys are actively used in many propulsion applications, there is a need for ongoing AM optimized alloys using integrated computational materials engineering (ICME) and process development for high performance applications. The applications targeted are liquid rocket engines; advanced propulsion systems; and in-space propulsion with high heat fluxes, high pressure, and/or that use propellants that can degrade alloys (e.g., hydrogen). This paper highlights the characterization and physical properties of the more common AM alloys using laser powder bed fusion (L-PBF) and laser powder directed energy deposition (LP-DED) processes. Additionally, this paper discusses some of the ongoing novel alloy development and maturation using AM for use in these harsh environments, such as GRCop-42, GRCop-84, NASA HR-1, GRX-810, and C-103. The results from these processes demonstrated that AM could enable rapid development, and that optimized alloys could be developed using ICME, yielding higher performances. These alloys have undergone modeling, fundamental metallurgical evaluations, heat treatment studies, detailed microstructure characterization, and mechanical testing campaigns. This, combined with direct application-specific component fabrication and hot-fire testing, enabled the increase of the Technology Readiness Level (TRL) through high duty-cycle testing. A background and overview of these novel AM-enabled alloys and AM processing developments including metallurgical and mechanical property studies is presented here. The latest advancement in the parallel component development and hot-fire testing and future developments for these alloys is also discussed. • Additive manufacturing (AM) has enabled development of novel alloys for extreme propulsion environments. • NASA has matured alloys including GRCop-42, GRCop-84, NASA HR-1, GRX-810, C-103. • Characterization, material properties, and hot-fire test application data has been made available. [ABSTRACT FROM AUTHOR]

Abstract: IMPRESS is an acronym for Intermetallic Materials Processing in Relation to Earth and Space Solidification. This project was selected by the European Commission and recently started in November 2004. The main scientific objective of IMPRESS is to gain a better understanding of the links between materials processing routes, structure and final properties of intermetallic alloys. Technically speaking, the project aims to develop and test two distinct prototypes based on intermetallic materials, namely gas turbine blades and Raney-type catalytic powder. Numerous material processing routes are being explored within the project with a strong emphasis on solidification. For turbine blade manufacturing, the principal processes under study are tilt casting, counter-gravity casting and centrifugal casting. For catalytic powder production, the focus is placed on gas atomisation and vapour condensation processes. IMPRESS combines a wide range of fundamental studies of solidification both on ground and in space, as well as industrial process development. This paper will describe some of the different facets related to solidification. [Copyright &y& Elsevier]

The porous and self-supported FeNi-alloy fiber paper is successfully fabricated. Under OER conditions, the Fe atoms leach out the surface of FeNi-alloy, resulting in facilitating surface reconstruction to generate the active FeNi-oxyhydroxide. And Fe atoms induce the longer Ni-O bonds within oxyhdroxide for accelerating the decomposition of *OOH intermediates to become O 2 , exhibiting outstanding OER performance. • A porous and self-supported FeNi alloy fiber paper was successfully fabricated. • The surface of FeNi alloy fiber paper occurs electrochemical reconstruction. • The nickel-iron oxyhydroxide is in-situ generate on surface of FeNi alloy. • Fe atoms can induce the longer Ni-O bonds within oxyhydroxides. • The longer Ni-O bonds promote the decomposition of *OOH intermediate to generate O 2. High-performance and low-cost electrocatalysts for oxygen evolution reaction (OER) are urgently desired to improve the overall efficiency of electrochemical water splitting. Here, a porous and self-supported FeNi-alloy fiber paper is successfully fabricated to achieve excellent OER performance with an ultralow overpotential, as well as remarkable stability. It is demonstrated that Fe substitution into metallic nickel can enable the inactive metallic nickel to endow highly electrocatalytic activity. Therefore, Fe substitution plays a key role for the outstanding performance. Specifically, the leaching of partial Fe atoms on surface of alloy facilitates surface reconstruction to generate active FeNi-oxyhydroxides under OER conditions. Meanwhile, Fe atoms can induce the lengthening of Ni-O bonds within oxyhydroxides for promoting the decomposition of *OOH intermediate species into O 2. This work provides new insights into the underlying mechanisms of Fe substitution into metal nickel for improving OER activity, which can accelerate the exploitation of low-cost, efficient and durable electrocatalysts. [ABSTRACT FROM AUTHOR]

Polymethylmethacrylate (PMMA) films are deposited on NiTi shape memory alloy by using the spin coating method. Different ratios of PMMA powder to Toluene were mixed with magnetic stirrer for a duration of 12 h. The various concentrations of solution (mol. %) were used for the spin coating method on the substrate NiTi to produce thin films. The samples were cured in various environment from room to furnace temperature. The surface features of PMMA films were investigated by using an optical microscope. Thermal and mechanical behavior of the NiTi substrate and composites was and studied in the paper. The spin coating and post-processing conditions determined the surface morphology that is featureless or dominate by pinholes and other surface defects. The spin-coated coating at 200 rpm improved film surfaces with 4 mol % PMMA solution. Surface defects in the form of pinholes appear on the surface of the film obtained by spin-coating at 3200 rpm from 8 mol % solution and post-baked at 80 °C for 60 min on a hot plate in an oven inside a vacuum chamber. Different coating properties depends on the preparation parameters by spin coating and thermal and microstructural, mechanical properties are explained and discussed in the paper. [ABSTRACT FROM AUTHOR]

Magnesium-based hydrogen storage alloy has become one of the most promising hydrogen storage alloy materials due to its high hydrogen storage capacity, lightweight and abundant resources. However, the practical application of MgH 2 for hydrogen storage is still impeded by its slow kinetics and high temperature of hydrogen absorption and desorption. In this paper, the literature on the modification of alloys in recent years is summarized, and the methods to improve the properties of magnesium-based hydrogen storage alloys are briefly discussed. The research progress of transition metal-based materials and light metals to improve the kinetic and thermodynamic properties of magnesium-based hydrogen storage alloys is reviewed mainly from the classification of metal substitution method, catalytic method and light metal complexation method. By comparing the differences and characteristics of each modification method, the development direction of preparation methods of magnesium-based hydrogen storage alloys is analyzed and prospected. The first two methods mainly improve the kinetic performance by reducing the activation energy of the reaction of the magnesium-based material, while the third method is to reduce the particle size of the magnesium-based material to the nanometer level, which can greatly reduce the reaction enthalpy change during the hydrogen absorption and desorption process of the alloy, thereby reducing the hydrogen absorption temperature of the magnesium-based material. • The property improved incriminate forming a solid solution and constructing a hydrogen pump. • The alloy kinetic property the are improved by expanding the contact area between H and alloy. • The physical adsorption of hydrogen by carbon-based materials acts as a hydrogen pump. • The complex cooperates with the catalyst to clearly improve the hydrogen storage property. [ABSTRACT FROM AUTHOR]

The sluggish de/hydrogenation kinetics and stable thermodynamics of magnesium hydride (MgH 2) are unfavorable for its large-scale application. Herein, the medium-entropy alloy CrCoNi nanosheets were synthesized and remarkably enhanced the low-temperature hydrogen storage performance of MgH 2. Surprisingly, the initial dehydrogenation temperature of 9 wt% CrCoNi modified MgH 2 was greatly reduced from 325 °C to 195 °C, a drop of 130 °C compared to non-additive MgH 2. Also, the MgH 2 –CrCoNi composite released 4.84 wt% hydrogen at 300 °C even in 5 min and absorbed 3.19 wt% hydrogen at 100 °C within 30 min (3.2 MPa). The calculated de/rehydrogenation activation energy were reduced by 45 and 55 kJ mol−1, respectively. Further cyclic kinetics investigation indicates that the 9 wt%-CrCoNi doped MgH 2 still presented good stability after 20 cycles, losing only 0.36 wt% hydrogen capacity. The XRD pattern validated that CrCoNi remained stable during the cyclic reaction process. Besides, the uniformly distributed CrCoNi nanosheets were in tight contact with the MgH 2 surface, providing abundant catalytic active sites and low-energy barrier diffusion channels. Under synergistic catalysis, the H atoms are rapidly absorbed and released across the Mg/MgH 2 interface, resulting in excellent kinetic properties. Briefly, this paper provides new references and inspirations to design efficient polymetallic catalysts for hydrogen storage materials. • CrCoNi nanosheets were prepared via a facile wet chemical ball milling method. • The de/hydrogenation performance of 9 wt% CrCoNi modified MgH 2 was greatly enhanced. • The synergistic effect of Cr, Co and Ni elements played a key role in the catalysis on MgH 2. [ABSTRACT FROM AUTHOR]

In this paper, Mg 2.3 Y 0.1 Ni + x wt.% graphene (x = 1, 3, 5, 7) composite hydrogen storage alloys were fabricated by mechanical ball milling of Mg 2.3 Y 0.1 Ni alloy powder and graphene. The experimental results show that the phases of the composite alloy consist mainly of Mg 2 Ni, Mg, MgNi 2 and Ni 3 Y phases, and graphene tends to be distributed at the edges of the alloy, increasing the phase boundary resulting from the contact between the C-boundary and the Mg 2.3 Y 0.1 Ni alloy, providing more channels for the diffusion of H 2. In which 7 wt.% of graphene is added, the gestation period of the composite alloy completely disappears. And the ball-milled alloy with 3 wt.% graphene at different temperatures has the highest hydrogen uptake in 2 min and the highest hydrogen release in 10 min. At 573 K, the composite alloy has a hydrogen absorption capacity of 3.251 wt.% H 2 in 2 min and reaches 90.21% of the maximum hydrogen absorption, while it is able to release 3.389 wt.% H 2 in 10 min and reaches 99.04% of the maximum hydrogen release. And the composite alloy with 3 wt.% graphene has the smallest dehydrogenation activation energy. The absolute value of the enthalpy change is reduced from 60.1 kJ/mol to 54.8 kJ/mol, and the desorption enthalpy change is reduced from 73.4 kJ/mol to 67.5 kJ/mol. • Addition of graphene increases the phase boundary of the composite alloy. • Graphene lowers the reaction barrier of the alloy with hydrogen. • Graphene improves the kinetics of hydrogen absorption/release of the alloy. • Graphene reduces the thermodynamic stability of composite alloys. [ABSTRACT FROM AUTHOR]

Joining of barium titanate (BaTiO 3 , BT) ceramics to metals plays an important role in their wide applications. However, conventional joining methods, including solid state diffusion joining and liquid state joining, have several drawbacks. In this paper, BT ceramic was flash joined to NiCrFe medium-entropy alloy (MEA) in seconds with an electric field (E-field) using current density of 10–80 mA/mm2 at 700–1000 °C. Shear strength of the joint first increased with applied current density and dwell time of the E-field and then decreased. It exceeded 40 MPa when the temperature was above 900 °C with current density of 60 mA/mm2 for 60 s. Both the real part (ε') and imaginary part (ε ") of complex permittivity of the joined sample were larger than those of the as-sintered BT ceramic at high frequency range. Microstructure of the joint suggests that a layer of chromium oxide was formed at faying surfaces, achieving effective bonding of BT and MEA. This research provides an efficient method for the manufacturing of BT based devices. [ABSTRACT FROM AUTHOR]

In this paper, the "flash brazing" of SiC is successfully achieved using Ag-Cu-Ti alloy in air for seconds at an ultra-low furnace temperature of 400 °C. The interface temperature reaches over 900 °C at an ultra-fast rate via the electric field assistance. The microstructure illustrates that SiC reacts with Ag-Cu-Ti alloy to form TiC to achieve the strong bonding of the joint, and the middle part of the joint is composed of silver-based solid solution and copper-based solid solution. With the increase of brazing holding time, the amount of copper-based solid solution in the joint gradually grows, and the shear strength of the joints first increases and then decreases. The maximum strength value of 70 MPa is obtained at 400 °C−10 A-60s. This method could help to improve the efficiency of ceramic bonding greatly. [ABSTRACT FROM AUTHOR]

The paper provides a literature review on the effect of ion irradiation on ceramic materials. The effects of ion irradiation on metals and alloys are compared with those on ceramics. Common patterns of the ion exposure effect on the considered types of materials are revealed. The focus is placed on the effect of this type of treatment on the microstructure, phase state and hardness of ceramics. Common patterns of structural and phase transformations, and effects of surface modification of oxide ceramics under exposure to accelerated ions are determined. Particular attention is given to such popular types of ceramics as zirconia and alumina. It is shown that surface treatment with both continuous and pulsed ion beams can efficiently modify the surface layers of oxide ceramics. This treatment induces formation of graded ceramics, with structure and mechanical properties varying from the surface to the bulk. The issues of radiation resistance of oxide ceramics are considered. It is shown that ceramics based on partially stabilized zirconia and alumina shows increased resistance to radiation (ionizing) exposure. [ABSTRACT FROM AUTHOR]

The monitoring of reactive oxygen species (ROS) in biological system has been occupying research hotspots recently, since the biochemical alterations caused by the overproduction of ROS are the main incentives of diseases and accelerated aging process. In this work, we proposed an effective and simple strategy for the construction of high-performance ROS electrochemical sensor. Noble metal alloy nanoparticles (AuPt nanoparticles) with high catalytic activity were spontaneously coated on the freestanding metallic molybdenum disulfide (MoS 2) paper independent of any auxiliary conditions. Results have found that the abundant defects and electrons distributed on the metallic MoS 2 paper could provide active sites for the nucleation and growth of noble metal nanoparticles. Besides, the excellent mechanical properties of the MoS 2 paper promote the formation of flexible sensors. The fabricated MoS 2 paper-based sensor was demonstrated to detect ROS with the advantages of wide linear range, prominent selectivity and flexibility, satisfactory detection stability, as well as simple and convenient preparation process. Furthermore, the desirable results obtained in the real sample experiments operated in plant extract pave the way for further real-time monitoring of plant physiological status to provide valuable information for guidance during plant growth. • A "spontaneous growth" strategy was proposed for constructing flexible ROS sensors. • Metallic MoS 2 paper with excellent properties was used as flexible sensing substrate. • High performance noble metal alloy nanoparticles were spontaneously modified. • AuPtNPs/MoS 2 paper shown outperforming activities in the ROS detection. • Satisfactory results were obtained in the real sample determination. [ABSTRACT FROM AUTHOR]

Abstract: A chordal graph is the intersection graph of a family of subtrees of a host tree. In this paper we generalize this. A graph has an -representation if there exists a host tree T of maximum degree at most h, and a family of subtrees of T, all of maximum degree at most s, such that if and only if . For given , and t, there exist infinitely many forbidden induced subgraphs for the class of -graphs. On the other hand, for fixed , every graph is an -graph provided that we take t large enough. Under certain conditions representations of larger graphs can be obtained from those of smaller ones by amalgamation procedures. Other representability and non-representability results are presented as well. [Copyright &y& Elsevier]

Metal-hydrides offer a potentially competitive method for compressing hydrogen, particularly where waste heat is available. Metal hydrides are metal alloys or intermetallic compounds that react reversibly with H 2. They readily absorb low-pressure H 2 at low temperature, and then release H 2 at a higher pressure when the temperature is raised. The high pressure H 2 is released at a pressure above that expected from standard press-temperature relations. The absorption and desorption pressures of the hydrides are determined by their thermodynamic properties (enthalpy and entropy). To achieve compression ratios above about 10, more than one stage of compression is typically required. The challenge is to find alloy pairs that can work together effectively to achieve the desired compression from the heating/cooling available. Previously, a thermodynamic model has been proposed for identifying suitable metal hydrides that can be paired together to achieve a desired compression. This paper describes methods used previously in the literature to select alloy pairs, and applies the current method to an example selection of 33 hydrides with potential for hydrogen compression. The example application aims to find pairs that can compress a H 2 stream from 10 to 350 bar using a temperature range of 30–150 °C, however the theory could readily be adapted to different compression ratios and temperature ranges. For the specific example evaluated none of the potential pairs were able to meet the compression target, however, modification of the parameters (heating/cooling availability) or alloy properties could resolve this issue. • Review of methods used to select alloys for metal hydride hydrogen compressors. • Worked example of thermodynamic model developed by [ 6 ] for the selection of alloy pairs for a dual stage compressor. • Application of model to real alloys highlighted in [ 2 ] incorporating effect of hysteresis and plateau slope. [ABSTRACT FROM AUTHOR]

The aim of the present paper was to evaluate the effect of hydroxyapatite coatings on the two types of Mg–Zn–Ag alloys as a possible solution to control magnesium alloy degradation. The coatings were prepared by the radio frequency magnetron sputtering method at a deposition temperature of 300 °C. To perform this evaluation, the coated alloys were immersed in a simulated body fluid solution at body temperature (37 ± 0.5 °C) to determine the corrosion resistance through electrochemical and immersion tests. Moreover, the investigation also consisted of the evaluation of microchemical, mechanical, and morphological properties. The deposition temperature of 300 °C was enough to obtain a crystalline hydroxyapatite structure with a Ca/P ratio close to the stochiometric one. The adhesion of coatings was not influenced by the nature of Mg–Zn–Ag alloys, so similar values for both coated alloys were found. The results showed that the coating was homogonous deposited on the Mg–Zn–Ag alloys and the corrosion resistance of uncoated magnesium alloys was improved. [ABSTRACT FROM AUTHOR]

Zn has garnered increasing attention in the realm of biodegradable materials due to its moderate degradation rate and no harmful gas released during degradation. However, the poor mechanical properties of Zn necessitate improvement by alloying and deformation processing. Currently, the primary studied Zn-based alloy systems include Zn-Mg, Zn-Li, Zn-Cu, Zn-Mn, Zn-Ag, and Zn-Ca alloys. Among these alloy systems, Mg is an essential element for the human body with advantages of low cost and good ability to enhance mechanical properties of Zn. Consequently, biodegradable Zn-Mg alloy exhibits fascinating application potential. This paper provides a comprehensive overview of research progress on Zn-Mg alloys by summarizing the effects of composition and deformation processing on degradation properties, biocompatibility, and mechanical properties. Additionally, this paper highlights existing challenges and hopes to offer new perspectives and ideas for researchers engaged in the study of degradable materials. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, the Zn additions combined with a novel severe plastic deformation (SPD) technology, screw twist extrusion (STE), is used to prepare Mg-xZn-1Mn alloys (x=0, 2, 4, 6) with fine grains and high ductility. By observing the microstructures, it is found that a gradient microstructure is obtained perpendicular to the extrusion direction (ED) in all four samples after STE. The STE process introduces twist extrusion strain into the samples, which causes the grain to twist and break, resulting in the weakening of the texture and the refinement of the grain. In addition, MgZn 2 phase is formed by the addition of high Zn, and the combination of MgZn 2 with twist shear strain further promoted dynamic recrystallization (DRX) to refine the grain and obtain the preferred texture, resulting in the increase of fracture elongation (FE). The FE of Mg-6Zn-1Mn sample improved from 18.4% to 27.8%, an 51.1% increase. This is mainly associated with the DRX mechanisms of continuous dynamic recrystallization (CDRX), discontinuous dynamic recrystallization (DDRX) and particle simulated nucleation (PSN). Meanwhile, the Schmid factor (SF) of basal slip increased with the addition of Zn, the basal slips in various samples are promoted obviously and FE is further enhanced. Thus, the novel STE technology combining with Zn additions provides an effective approach to improve the ductility of Mg-Zn-Mn alloys. • The ductility of Mg-Zn-Mn alloy is enhanced by Zn addition combined with STE process. • A variety of DRX behaviors have been studied in STEed Mg-χZn-Mn alloys. • The method proposed in this paper to enhance the ductility of Mg-Zn-Mn alloys is a good choice for the application of degradable biomedical devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • The paper provides a comprehensive review of state-of-the-art titanium alloys and composites for orthopedic implants. • Recent advances in surface modification techniques aimed at enhancing implant biocompatibility are highlighted. • Recent advances in manufacturing methods for tailored titanium biomaterials are investigated. • The paper summarizes the transformative impact of machine learning on alloy design, process optimization, quality control, and customization. The increasing demand for orthopedic implants has driven the search for materials that combine strength, biocompatibility, and long lifetime. Compared to stainless steel and Co-Cr-based alloys, titanium (Ti) and its alloys are favored for biomedical implants because of their high strength, corrosion resistance, and biocompatibility. This comprehensive review delivers a wide overview of the field of Ti-based biomaterials for orthopedic implants applications, focusing on their types, mechanical and chemical resistance, surface modifications, innovations in fabrication techniques, Ti matrix composites, and machine learning (ML) advancements. Ti alloys of different crystalline phases, including α, near-α, (α + β), β, and shape memory alloys, offer diverse options for orthopedic applications. Strengthening properties, wear, fatigue, and corrosion resistance are crucial factors influencing the performance and reliability of Ti implants. Moreover, this review discussed the challenges to Ti-based biomaterial durability through surface modifications to enhance their biofunction, wear resistance, corrosion resistance, and antibacterial properties. Recent developments in fabrication techniques for Ti-based biomaterials are also discussed. Eventually, this review investigated how ML revolutionized Ti orthopedic implants by providing insights into the behavior of new alloys, aiding in manufacturing optimization, allowing for real-time quality control, and advancing the development of personalized, biocompatible, and reliable implants. [ABSTRACT FROM AUTHOR]

The purpose of this review paper is to describe a noble approach, called Growing Integration Layers (GIL) method, for the application of biocompatible oxide ceramics layers coating on bulk metallic alloys. Since these oxides are utilizing component(s) of the alloy then formed by mostly electrochemical reactions at low temperatures, they are well adhered on the alloy substrate. The GIL strategy differs significantly from so-called layer-by-layer integration, layers are deposited from top-to-top. In the GIL, the oxide layers are produced and grown on the substrate alloy from the bottom. Therefore those layers on metallic substrate is chemically and structurally continuous thus shows excellent adhesion. Using GIL method, a variety of functional and structural ceramic layers can be processed mostly in aqueous solutions, thus they are typical soft and green processes, consuming low energy. These methods can be applied in the preparation of dense/porous and graded intermediate layers of ceramics for a wide variety of applications, including thermal, mechanical, chemical and biomedical. This review concentrate on successful ceramics coating on Titanium based metallic alloys via GIL strategy. The GIL technology improves the adhesion of ceramic layers and introduces bioactivity to bulk metallic alloys. Since bulk metallic glasses and alloys generally contain active components like titanium, it can be used in the formation of titanium oxide and/or hydroxides which are bioactive. During this oxidation/hydroxidation, widely diffused interfaces and continuously graded layers are formed from bulk substrate, even at ambient temperature and pressure. One of the most notable examples of GIL method is the coating of bio-active hydroxyapatite (HA) ceramics on Ti alloys. We have exhibited here with (1) Bioactive ceramic layers on bulk metallic glasses, (2) Hydroxyapatite-like coating on Ti–Cu–Sn alloy and (3) Sr doped apatite-like coating on the same alloy. [ABSTRACT FROM AUTHOR]

This paper proposes an environmentally friendly one-pot synthesis approach for the PtCu and PtNi nanoparticles with the gradient structure on the carbon support. This method offers exceptional advantages over other approaches. Among them there is a surfactant-free synthesis, being low-temperature, simple, fast, and one-pot. The bimetallic electrocatalysts with a reduced platinum content for proton-exchange membrane fuel cells have been obtained. The proposed method is promising in terms of scaling and transition to commercial production. In this study, we first attempted to apply the gradient synthesis strategy to the PtNi/C catalysts in order to make this method versatile. We obtained the high-performance PtNi/C and PtCu/C catalysts, exhibiting the specific ORR activity higher than that of the commercial Pt/C catalyst by 3 and 4.6 times, respectively. [Display omitted] • New Pt-based nanostructured ORR electrocatalysts were obtained by a simple, versatile, and scalable method. • The PtCu and PtNi nanoparticles with Pt overlayers supported on carbon were synthesized by a gradient strategy. • PtNi/C and PtCu/C showed enhanced activity in the ORR compared with the commercial Pt/C. • The surfactant-free one-pot synthesis was used to obtain the PtNi and PtCu nanoparticles. • The environmentally friendly method was used to prepare Pt-based electrocatalysts. [ABSTRACT FROM AUTHOR]

In this paper, we study the effect of deposition temperature on the structural and nanomechanical properties on the degradation and bioactivity behaviour of Mg doped hydroxyapatite (HAP) deposited on AZ31B alloy substrates extracted by parts manufactured according to the prostheses production route. The coatings were prepared by RF (Radio Frequency) magnetron sputtering technique at room temperature (RT) and 200 °C, respectively. By adding Mg into the HAP matrix, the hardness and elastic modulus values of the coatings have significantly improved as compared to the bare HAP, the highest H3/E2 ratio of 0.022 being obtained for the HAP + Mg at 200 °C. XRD analysis showed the presence of an α-Mg hexagonal structure for the uncoated AZ31B alloy, while the GIXRD patterns revealed the presence of HAP and Mg in the coated samples. The crystallinity degree of HAP is not changed by Mg addition, while the apatite structure was preserved for all investigated coatings. All investigated samples exhibited typical IR bands of phosphate, carbonate, and hydroxyl functional groups, confirming the formation of apatite phases. By increasing the deposition temperature from room temperature up to 200 °C, the electrochemical behaviour of the coatings, in simulated body fluid and Dulbecco's Modified Eagle Medium, is improved obtaining more electropositive values for corrosion potential, smaller current densities, and higher polarization resistance. The coatings deposited at 200 °C showed the best electrochemical behaviour. Also, by increasing the deposition temperature and incorporating Mg into HAP matrix, the hardness and elastic modulus are increased by more than two-fold, as compared to pure HAP. Furthermore, all coatings deposited on AZ31B alloys are suited for further coating with a mussel-derived surface-binding peptides, but the coatings deposited at 200 °C led to the most regular peptide distribution on the surface. Overall, the results indicated that the biodegradation of HAP + Mg based coatings and the AZ31B alloys can be controlled according to the current clinical needs within implantology field. [ABSTRACT FROM AUTHOR]

Al and its alloys are studied extensively for hydrogen generation through water splitting. Alloying Al with metal activators such as bismuth, indium, gallium, etc., leads to the formation of micro galvanic cells during hydrolysis reaction, resulting in an improved hydrogen generation rate. Activation of Al by adding carbon-based materials such as graphite, carbon nanotubes (CNTs), graphene, etc., can instantaneously generate hydrogen at room temperature. When carbon particles are desorbed from the Al matrix during hydrolysis, new Al is exposed, resulting in an increased reaction rate. In Al-Graphite composites which form core-shell structures, H 2 O molecules penetrate through the graphite layers and break down the core-shell structure during hydrolysis, and the new Al surfaces are exposed to water. It was found that Al with nano bismuth and graphene nanosheets showed better hydrogen generation rate and hydrogen yield. Graphene nanosheets control the agglomeration of Al and enhance the specific surface area for hydrolysis. During the hydrolysis of Al-CNTs composites, CNTs act as a cathode, resulting in galvanic corrosion between CNTs and the Al matrix. CNTs can also effectively control the agglomeration of Al during ball milling. Spark plasma sintered Al–Bi-CNT composites showed an enhanced hydrogen generation rate during hydrolysis. This paper presents an overview of hydrogen generation by hydrolysis of Al and its alloys, emphasising the addition of carbon-based materials such as graphite, graphene, CNTs, etc. • Activation methods to promote Al hydrolysis for hydrogen generation are discussed. • Hydrolysis of Al alloys with the addition of carbon-based materials are presented. • Carbon-based materials effectively control the agglomeration during milling. • Various hydrolysis reaction mechanisms are discussed in detail. • Using biomass-derived carbon as an additive to Al alloys could be a future research focus. [ABSTRACT FROM AUTHOR]

This paper describes the efficient preparation of an Mg 2 Ni alloy for hydrogen storage via high-energy ball milling mechanical alloying for 2 h. The degree of alloy amorphisation increases with increasing ball-milling time. Ball milling for 4 h affords partially amorphous alloys exhibiting the best hydrogen storage performance. Partial substitution of Ni with Cr and Mn improves the hydrogen absorption/desorption thermodynamics, kinetics and cycling performance of the alloy. Specifically, partial Mn substitution improves the cycling performance and reduces the activation energy of the hydrogen desorption reaction, effectively improving the hydrogen desorption kinetic performance. Mg 2 Ni 0.8 Mn 0.2 shows the best cycling and hydrogen absorption/desorption kinetic performances. Partial Cr substitution reduces the entropy and enthalpy changes of the hydrogen absorption/desorption reaction and effectively reduces the temperature of the initial hydrogen absorption/desorption reaction. In particular, Mg 2 Ni 0.9 Cr 0.1 shows the best thermodynamic performance. [Display omitted] • An optimised method for fabricating Mg 2 Ni alloys for hydrogen storage was developed • Mn addition effectively improves the cycle and kinetic performance of Mg 2 Ni alloys • Cr addition improves the thermodynamic properties of Mg 2 Ni alloys [ABSTRACT FROM AUTHOR]

In this paper, we present the assessment of measurement uncertainties in the wire electrical discharge machining (WEDM). The type A, type B, and total uncertainties are considered when measurement of the voltage and current for the WEDM is carried out, whereas for both the correlated and uncorrelated energy measurements, the corresponding complex and relative uncertainties are determined. Therefore, the procedure proposed in the paper allows for the accurate fulfillment of measurements in the field of the WEDM. Hence, the main purpose of this paper is to determine the influence of uncertainties related measurement data obtained during the WEDM on the surface condition. The second and third sections of this paper present the basics of the WEDM and the materials used during its implementation. The fourth chapter presents the mathematical basis for the evaluation of the WEDM uncertainty, while the fifth chapter deals with the implementation of exemplary calculations and the evaluation of uncertainties occurring during this type of machining. The procedure proposed in this paper can be used for both theoretical calculations and practical implementations used within the WEDM, with particular emphasis on the assessment of the impact of single impulse energy, current, and voltage amplitude on the WEDM process, as well as the surface condition after machining of NiTi alloy. • Wire electrical discharge machining. • Uncertainty assessment. • Measurement uncertainty. • NiTi Alloys. [ABSTRACT FROM AUTHOR]

Graphene can been used to improve the hydrogen storage performance of magnesium based materials because of its outstanding electrical conductivity, high specific surface area, and good mechanical qualities. In this paper, mechanical ball milling method was utilized to prepare the CeMg 12 /Ni alloy combined with graphene in order to investigate the impact of graphene on microstructure, kinetics, and thermodynamic properties of alloy. The results reveal that the addition of graphene can refine the grains of alloy, increase the surface defects of alloy particles and promote Ni to be dissolved in the main phase of the alloy. The absolute value of enthalpy drops from 65.27 kJ/mol to 60.3 kJ/mol when Graphene is added at a higher concentration. The addition of graphene improves the dehydrogenation performance of alloy hydride by lowering its thermal stability. Because of a minimum dehydrogenation activation energy of 85.23 kJ/mol and dehydrogenation characteristic time of 1090s, the alloy with 6 wt% Graphene exhibits the best dehydrogenation kinetic performances. • 1 The structural feature of Graphene is profit to increase the surface activity. • 2 Addition of Graphene is beneficial for improving thermodynamic performance. • 3 Adding Graphene can reduce the apparent activation energy of hydrogen releasing. • 4 The structure of Graphene is good for ameliorating the hydrogen sorption properties. [ABSTRACT FROM AUTHOR]

Among the electrode materials for Ni-MH batteries, the Mg alloy electrodes such as MgNi, Mg 2 Ni, REMg 12 , La 2 Mg 17 are considered the most suitable anode materials due to their high discharge capacity and low cost. However, the poor electrochemical cycling stability prevents its practical application. In this paper, Mg 50-x V x Ni 45 Fe 3 Zn 2 (x = 0, 1, 2, 3, 4) + 50 wt% Ni alloys were prepared by partially replacing Mg with V and using mechanical ball milling techniques with amorphous and nanocrystalline structures. Electrochemical tests showed that the ball-milled alloy had good electrochemical uptake and release performance. The maximum release performance is achieved in the first cycle. After that, the discharge level and cycle stability increased significantly with increasing ball grinding time and V content. • Mg–V–Ni–Fe–Zn based alloys were prepared by vacuum induction melting. • Ball milling is beneficial to improve electrochemical kinetics. • Prolonging the milling time can improve the cycle stability. • The as-milled alloys show active electrochemical properties at room temperature. [ABSTRACT FROM AUTHOR]

The main topic of this paper is the investigation of generalized amalgamation properties for simple theories. That is, we are trying to answer the question of when a simple theory has the property of n-dimensional amalgamation, where two-dimensional amalgamation is the Independence Theorem for simple theories. We develop the notions of strong n-simplicity and n-simplicity for 1≤n≤ω, where both “1-simple” and “strongly 1-simple” are the same as “simple”. For strong n-simplicity, we present examples of simple unstable theories in each subclass and prove a characteristic property of strong n-simplicity in terms of strong n-dividing, a strengthening of the dependence relation called dividing in simple theories. We prove a strong three-dimensional amalgamation property for strongly 2-simple theories, and, under an additional assumption, a strong (n+1)-dimensional amalgamation property for strongly n-simple theories. In the last section of the paper we comment on why strong n-simplicity is called strong. [Copyright &y& Elsevier]

• Mechanical stability plays a key role in the effectiveness of external fixators. • Strength and stiffness are the main factors which contributes towards stability. • Modified configurations of linear, circular and hybrid fixators are investigated. • Light weight composite materials are gradually replacing traditional metallic alloys. • Existing research gaps in further optimizing external fixators are identified. External Fixators are a common technique used to treat a variety of issues related to bones, predominantly due to its non-intrusive nature and versatility in terms of form and materials. While it is mainly used to treat open fractures, its other uses include limb lengthening, deformity correction, bone grafting, compression of non-unions and stabilization of dislocations. Its earliest use dates as far back as 400 BCE and has undergone significant improvements, focusing on both customization and optimization. These two aspects highlight the significance of complementing the orthopaedic requirements with engineering knowledge and its applications. Hence, this review paper aims to conduct an examination of recent developments of external fixators with a special focus on its structure, the usage of materials and biomechanical investigations using experimental and numerical techniques. The paper presents the existing level of engineering knowledge with regards to these aspects and identifies research gaps, which can improve the quality of the commonly used external fixators. [ABSTRACT FROM AUTHOR]

In this paper, the experimental alloy with the standard composition of Ti 1.1- x Zr 0.1 Y x Fe 0.6 Ni 0.3 Mn 0.2 (x = 0–0.08) was synthesized by vacuum induction melting. The activation properties and hydrogen absorption/desorption kinetics were significantly improved by adding different amounts levels of rare earth elements Y to partially replace Ti in TiFe alloys. The microstructure, phase composition and hydrogen storage properties of the alloy before and after hydrogen absorption/desorption were characterized and tested by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and Sieverts-type manual PCT hydrogen storage tester. The experimental results show that the as-cast alloy consists of Ni-rich TiFe main phase, a small amount of ZrMn 2 phase biased on the TiFe phase and Y-rich phase. The addition of Y significantly increases the phase boundary and refines the crystallization, and significantly shortens the activation incubation period of the cast alloy. The alloy requires only the first hydrogen absorption to fully achieve activation at 150 °C, and still exhibits a fast hydrogen absorption rate at −10 °C. Meanwhile, When the Y content is 0.02, the saturation rate (R 100 a) of hydrogen absorption reaches 92%, and the maximum hydrogen absorption capacity is 1.704 wt% at 70 °C. And the absolute values of the enthalpy and entropy changes of hydrogen absorption/desorption increase with the increasing of Y content. • Adding Y increased the phase boundary and refined the grain size of as-cast alloy. • The activation incubation period is reduced to 150 s for Y 0.02 alloy. • Y 0.02 alloy absorbs 1.711 wt% H and its saturation rate reaches 92.3% in 100 s. • Adding Y reduces the inclination and hysteresis of P-C-T curve platform. [ABSTRACT FROM AUTHOR]

Ni–Mn–In Heusler alloys have received considerable attention in the field of magnetic refrigeration owing to their eco-friendliness and large magnetocaloric (MC) response. In this paper, samples of Ni 45 Co 5 Mn 37 In 12 Si 1 thus heat-treated for 0 h and 15 h have prepared by means of arc-melting followed by quenching. X-ray diffraction analysis confirms L2 1 -type crystal structure and stabilization of austenite phase at room temperature. FE-SEM equipped with EDS reveals the surface morphology and elemental composition of 15 h heat-treated Ni 45 Co 5 Mn 37 In 12 Si 1 alloy with well-distinguished larger grains and a dendritic structure. Thermomagnetic measurements of 15 h heat-treated Ni 45 Co 5 Mn 37 In 12 Si 1 shows the magnetostructural transition T C M at the temperature of ∼262 K and Curie temperature of austenite, T C A was found to be above ∼396 K with increase in the annealing time. Metamagnetic behavior and magnetic hysteresis are seen in isothermal magnetization curves. Interestingly, a large change in magnetic entropy ΔS M ∼9.3 J kg−1 K−1 was obtained with refrigeration capacity (RC) of ∼416.6 J kg−1 under an applied field change of 5T with a broad temperature window of ∼86 K for Ni 45 Co 5 Mn 37 In 12 Si 1 alloy thus annealed for 15 h which makes it to be suitable for magnetic refrigeration applications. [ABSTRACT FROM AUTHOR]

Enamel coating, which is of low thermal conductivity and high chemical stability, has been employed for the protection of many hot parts against oxidation. It is composed of multiple oxides, and each oxide component plays a certain role on thermophysical properties. In this paper, a type of silicate enamel coating with different contents of oxide component Al 2 O 3 was prepared on K444 superalloy. Its microstructural evolution and cyclic oxidation behavior at 1000 °C were investigated. Results indicated that the A0 enamel coating, which was free of Al 2 O 3 in composition, suffered from serious crystallization at high temperature. The formation of quartz, cristobalite and SrSiO 3 crystals resulted in significant mass loss during cyclic oxidation. However, precipitation of these crystals was almost completely prohibited in the A10 and A15 coatings with 10 and 15 wt% Al 2 O 3 , respectively. The A10 coating had no mass loss after cyclic oxidation. But much high content of Al 2 O 3 resulted in the formation of abundant long strip crystals of SrAl 2 Si 2 O 8 in the A15 coating, which led to minor spallation. Furthermore, enamel coatings with Al 2 O 3 (above 6 wt%) promoted the formation of a continuous alumina scale at the enamel/alloy interface, which improved oxidation resistance and increased bonding strength. The well grown alumina scale at interface as well as the mild crystallization ensured high spallation resistance of the enamel coating A10. [ABSTRACT FROM AUTHOR]

In diesel reforming, a catalyst is easily deteriorated by thermal sintering and coke formation. A proper preparation method improves stability by modifying the physicochemical properties of the catalyst. In this paper, the effects of preparation methods on exsolution and alloy formation in PtRu bimetallic catalysts for diesel reforming were studied. The catalysts were prepared by impregnation and combustion synthesis. The structure, surface morphology, and reduction characteristics of each catalyst were characterized by XRD, STEM, and H 2 -TPR. Based on these characterizations, the behavior of each catalyst in the reforming environment was identified by comparison of properties observed before and after the reaction. Pt and Ru individually crystallized from the impregnated catalyst, whereas Pt and Ru exsolved from the combustion synthesis catalyst to form a PtRu alloy. As a result, the combustion synthesis catalyst showed higher stability and coke resistance than the impregnated catalyst. [Display omitted] • PtRu bimetallic catalysts for diesel reforming were prepared by different methods. • In the impregnated catalyst, metals crystallized separately without forming alloys. • In the combustion synthesis catalyst, metals exsolved and formed alloy nanoparticles. • The PtRu alloy catalyst showed higher stability and coke resistance. [ABSTRACT FROM AUTHOR]