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This study investigates the effect of laser volume energy density (VED) on the properties of AISI 420 stainless steel and TiN/AISI 420 composite manufactured by selective laser melting (SLM). The composite contained 1 wt.% TiN and the average diameters of AISI 420 and TiN powders were 45 µm and 1 µm, respectively. The powder for SLMing the TiN/AISI 420 composite was prepared using a novel two-stage mixing scheme. The morphology, mechanical, and corrosion properties of the specimens were analyzed, and their correlations with microstructures were investigated. The results showed that the surface roughness of both SLM samples decreases with increasing VED, while relative densities greater than 99% were achieved at VEDs higher than 160 J/mm3. The SLM AISI 420 specimen fabricated at a VED of 205 J/mm3 exhibited the highest density of 7.7 g/cm3, tensile strength (UTS) of 1270 MPa, and elongation of 3.86%. The SLM TiN/AISI 420 specimen at a VED of 285 J/mm3 had a density of 7.67 g/cm3, UTS of 1482 MPa, and elongation of 2.72%. The microstructure of the SLM TiN/AISI 420 composite displayed a ring-like micro-grain structure consisting of retained austenite on the grain boundary and martensite in the grain. The TiN particles strengthened the mechanical properties of the composite by accumulating along the grain boundary. The mean hardnesses of the SLM AISI 420 and TiN/AISI 420 specimens were 635 and 735 HV, respectively, which exceeded previously reported results. The SLM TiN/AISI 420 composite exhibited excellent corrosion resistance in both 3.5 wt.% NaCl and 6 wt.% FeCl3 solutions, with a resulting corrosion rate as low as 11 µm/year.

We have examined the spatial distributions of polymer chains in blend films of weakly segregated polystyrene-block-poly(methyl methacrylate) [P(S-b-MMA)] and deuterated polystyrene (dPS). By fine-tuning the composition (ϕPS+dPS = 63.8 vol %) of the total PS/dPS component and annealing temperature (230 and 270 °C), P(S-b-MMA)/dPS blend films mainly form perforated layers with a parallel orientation (hereafter PLs//). The distributions of dPS in PLs// were probed by grazing-incidence small-angle neutron scattering (GISANS) and time-of-flight neutron reflectivity (ToF-NR). GISANS and ToF-NR results offer evidence that dPS chains preferentially locate at the free surface and within the PS layers for blend films that were annealed at 230 °C. Upon annealing at 270 °C, dPS chains distribute within PS layers and perforated PMMA layers. Nevertheless, dPS chains still retain a surface preference for thin films. In contrast, such surface segregation of dPS chains is prohibited for thick films when annealed at 270 °C.

Although high-entropy alloys have been intensively studied in the past decade, there are still many requirements for manufacturing processes and application directions to be proposed and developed, but most techniques are focused on high-entropy bulk materials and surface coatings. We fabricated high-entropy ceramic (HEC) nanomaterials using simple pulsed laser irradiation scanning on mixed salt solutions (PLMS method) under low-vacuum conditions. This method, allowing simple operation, rapid manufacturing, and low cost, is capable of using various metal salts as precursors and is also suitable for both flat and complicated 3D substrates. In this work, we engineered this PLMS method to fabricate high-entropy ceramic oxides containing four to seven elements. To address the catalytic performance of these HEC nanomaterials, we focused on CoCrFeNiAl high-entropy oxides applied to the oxygen-evolution reaction (OER), which is considered a sluggish process in water. We performed systematic material characterization to solve the complicated structure of the CoCrFeNiAl HEC as a spinel structure, AB2O4 (A, B = Co, Cr, Fe, Ni, or Al). Atoms in A and B sites in the spinel structure can be replaced with other elements; either divalent or trivalent metals can occupy the spinel lattice using this PLMS process. We applied this PLMS method to manufacture electrocatalytic CoCrFeNiAl HEC electrodes for the OER reaction, which displayed state-of-the-art activity and stability.

Graphene shows unique properties such as high mechanical strength and high thermal and chemical stability, making it promising for versatile applications. However, the lack of either interlayer or interface covalent bonds causes this type of 2D materials assembled via van der Waals forces to suffer from weak adhesion with the underlying substrates, thus hindering their application. In this study, a novel method based on a hydrothermal reaction was proposed to synthesize fluorinated graphene (FG) through a facile, scalable, and highly safe process, where a mixture of poly(perfluorosulfonic acid) (C7HF13O5S·C2F4, PFSA) and graphene oxide (GO) as the precursor was employed. The FG sheets prepared by the electrophoretic deposition (EPD) method exhibit superior conformity layered structure on a metal foil. Due to the in situ formation of ionic-covalently bonded F-Cu-F and Cu-F-C between fluorine on the FG sheets and dissolved Cu ions from the copper foil, the deposited film shows ultrastrong adhesion that can sustain up to 3 MPa of shear force. Furthermore, by changing the parameters in the EPD process, such as the EPD duration and applied voltage, the thickness and hydrophobicity of the film can be well controlled from 0.20 μm to 2.51 μm with a contact angle from 93.03˚ to 122.44˚. This study provides a new strategy to prepare a robust film for the assembly of 2D materials, not limited to graphene, with ultrastrong adhesion on substrates, which could solve the long-reported issue of weak adhesion and low durability of graphene-/2D-based functional composites and coatings.

We have examined the spatial distributions of polymer chains in blend films of weakly segregated polystyrene

Most high-entropy alloys and medium-entropy alloys (MEAs) possess outstanding mechanical properties. In this study, a series of lightweight nonequiatomic Al50–Ti–Cr–Mn–V MEAs with a dual phase were produced through arc melting and drop casting. These cast alloys were composed of body-centered cubic and face-centered cubic phases. The density of all investigated MEAs was less than 5 g/cm3 in order to meet energy and transportation industry requirements. The effect of each element on the microstructure evolution and mechanical properties of these MEAs was investigated. All the MEAs demonstrated outstanding compressive strength, with no fractures observed after a compressive strain of 20%. Following the fine-tuning of the alloy composition, the Al50Ti20Cr10Mn15V5 MEA exhibited the most compressive strength (~1800 MPa) and ductility (~34%). A significant improvement in the mechanical compressive properties was achieved (strength of ~2000 MPa, strain of ~40%) after annealing (at 1000 °C for 0.5 h) and oil-quenching. With its extremely high specific compressive strength (452 MPa·g/cm3) and ductility, the lightweight Al50Ti20Cr10Mn15V5 MEA demonstrates good potential for energy or transportation applications in the future.

A series of biocompatible high-porosity (up to 72.4%) TiZr-based porous bulk metallic glass (BMG) scaffolds were successfully fabricated by hot pressing a mixture of toxic element-free TiZr-based BMG powder and an Al particle space holder. The morphology of the fabricated scaffolds was similar to that of human bones, with pore sizes ranging from 75 to 250 μm. X-ray diffraction patterns and transmission electron microscopy images indicated that the amorphous structure of the TiZr-based BMG scaffolds remained in the amorphous state after hot pressing. Noncytotoxicity and extracellular calcium deposition of the TiZr-based BMG scaffolds at porosities of 32.8%, 48.8%, and 64.0% were examined by using the direct contact method. The results showed that the BMG scaffolds possess high cell viability and extracellular calcium deposition with average cell survival and deposition rates of approximately 170.1% and 130.9%, respectively. In addition, the resulting TiZr-based BMG scaffolds exhibited a considerable reduction in Young’s moduli from 56.4 to 2.3 GPa, compressive strength from 979 to 19 MPa, and bending strength from 157 MPa to 49 MPa when the porosity was gradually increased from 2.0% to 72.4%. Based on the aforementioned specific characteristics, TiZr-based BMG scaffolds can be considered as potential candidates for biomedical applications in the human body.

A novel lightweight Al-Ti-Cr-Mn-V medium-entropy alloy (MEA) system was developed using a nonequiatiomic approach and alloys were produced through arc melting and drop casting. These alloys comprised a body-centered cubic (BCC) and face-centered cubic (FCC) dual phase with a density of approximately 4.5 g/cm3. However, the fraction of the BCC phase and morphology of the FCC phase can be controlled by incorporating other elements. The results of compression tests indicated that these Al-Ti-Cr-Mn-V alloys exhibited a prominent compression strength (~1940 MPa) and ductility (~30%). Moreover, homogenized samples maintained a high compression strength of 1900 MPa and similar ductility (30%). Due to the high specific compressive strength (0.433 GPa·g/cm3) and excellent combination of strength and ductility, the cast lightweight Al-Ti-Cr-Mn-V MEAs are a promising alloy system for application in transportation and energy industries.

The Fenton reaction is a commonly used technique for the remediation of industrial pollution, but hydrogen peroxide required in this reaction is highly hazardous and the enormous volume of iron sludge byproducts increases significantly the cost of pollution remediation. To address this issue, this study examined the efficacy of the electro-Fenton reaction in degrading pollutants utilizing a complex of graphene and a high-entropy ceramic catalyst, and evaluated the potential of functionalized high-entropy materials for the decomposition of pollutants. The degradation of organic water contaminants was investigated utilizing a novel composite of graphene and (AlCrCuFeNi)O high-entropy ceramics, to increase the generation of H2O2 in the electro-Fenton process. Rapid calcination produced five-element (AlCrCuFeNi)O high-entropy ceramics to enhance both the electrocatalytic activity and the stability. Because of the high electro-Fenton efficiency of the high-entropy ceramics, the graphene/(AlCrCuFeNi)O HEC cathode effectively removed 99% methyl orange within 90 min of operation.

How to effectively reduce anthropogenic greenhouse gases emission to alleviate global warming has been a public concern since 20th century. Hence, development of effective CO2 and CH4 reduction technique is a common objective worldwide. Simultaneous conversion of CO2 and CH4 into syngas can be a candidate to achieve the objective. Among several conversion techniques, plasma and photocatalysis are two promising techniques possessing good potentials. In this work, a spark discharge reactor and a series of perovskite-type photocatalysts are developed and combined to form hybrid plasma photocatalysis systems to evaluate the effectiveness for converting CO2 and CH4 to form syngas. Experimental results indicate that the spark discharge reactor packed with LFO600 photocatalyst increases the syngas generation rate from 13.0 to 18.5 mol per kilowatt-hour, corresponding to 42% of enhancement. Furthermore, characterizations of photocatalysts reveal that plasma can promote the surface structure of photocatalyst to increase the lifetime of electron-hole pairs which possibly leads to higher syngas generation rate. Additionally, the hybrid plasma photocatalysis system developed has been demonstrated with good potential to improve plasma and photocatalysis performances.

Using the CALPHAD method, lightweight nonequiatomic Ti60(Al)x(VCrNb)40-x (x = 6, 8, 10, 12, and 18 at.%) medium-entropy alloys (MEAs) were designed and produced using vacuum arc melting and drop casting. The density of these cast alloys decreased with an increase in Al concentration from 5.45 to 4.79 g cm−3. All of these cast alloys exhibited a body-centered cubic (BCC) microstructure. However, a nanosized ordered B2 phase was identified in the cast alloys with higher Al concentrations (Al-12 and Al-18). The prediction of BCC phase formation using CALPHAD was consistent with the experimental results. These BCC-structured alloys can withstand over 50% strain at room temperature, which demonstrates excellent compressive ductility. Moreover, the results demonstrate that the as-cast Al-6 and Al-8 samples had superior plasticity under tensile testing, with a tensile strength of 1120 MPa and approximately 30% plastic strain. Furthermore, with an increase in Al concentration, the alloys exhibited a notable trend in yield strength and a decreasing trend in plastic strain. The change in mechanical properties of these MEAs caused by the formation of B2 nanoparticles was also investigated.

In this study, heavily boron-doped hydrogenated Ge epilayers are grown on Si substrates at a low growth temperature (220 °C). The quality of the boron-doped epilayers is dependent on the hydrogen flow rate. The optical emission spectroscopic, X-ray diffraction and Hall measurement results demonstrate that better quality boron-doped Ge epilayers can be obtained at low hydrogen flow rates (0 sccm). This reduction in quality is due to an excess of hydrogen in the source gas, which breaks one of the Ge-Ge bonds on the Ge surface, leading to the formation of unnecessary dangling bonds. The structure of the boron doped Ge epilayers is analyzed by transmission electron microscopy and atomic force microscopy. In addition, the performance, based on the I-V characteristics, of Ge/Si photodetectors fabricated with boron doped Ge epilayers produced under different hydrogen flow rates was examined. The photodetectors with boron doped Ge epilayers produced with a low hydrogen flow rate (0 sccm) exhibited a higher responsivity of 0.144 A/W and a lower dark current of 5.33 × 10 −7 A at a reverse bias of 1 V.

The oxygen evolution reaction (OER) is the half reaction in the overall reaction of electrocatalytic water splitting, and it involves four electron transfers. The aforementioned electron requirement implies that the OER requires more energy than the HER, thus limiting the overall water splitting efficiency. Here, we propose a novel anode catalyst by using an advanced composite material of selenized nickel–iron electrodes together with NiFe_LDH. An analysis of the water splitting performance was carried out in different concentrations of a seawater-like electrolyte, which, in terms of corrosion reactions, is a relatively harsher environment than that found in natural seawater. In this study, we discovered that a Se_NiFe foam electrode with an LDH layer exhibited extraordinary stability and activity in an aqueous sea-like solution, demonstrating an improved overpotential from the original 1.62 V–1.43 V in a seawater electrolyte mixture. Furthermore, the Tafel slope significantly decreased from 115.1 mV dec−1 to 26.3 mV dec−1. Notably, the lifespan of this novel electrode was extended from 80 h to 250 h. The mechanism of improved stability and corrosion resistance is also investigated in this study.

Due to the demand for reduced energy consumption by transportation vehicles, lighter weight high-entropy alloys (with density comparable to that of commercial Ti alloys around 4.5–5 g/cm3) are attracting more attention in terms of alloy design and application as structural materials. In this study, a nonequiatomic quaternary alloy system, Tix(AlCrNb)100-x, was designed through the calculation of phase diagrams. Simulation results reveal that a single body-centered cubic (BCC) phase can be formed and can be stable at temperatures above 950 °C. Accordingly, a series of Tix(AlCrNb)100-x (x = 45–80) alloys containing a BCC structure were prepared through vacuum arc melting and rapid cooling. The designed alloys can exhibit desirable mechanical properties with high compression yield strength about 1500 MPa, high compression fracture strength about 1800 MPa and high compression plasticity more than 30% at room temperature. Moreover, the Ti65 alloy can demonstrate a tensile strength of 1200 MPa with a tensile elongation of 32%, after a homogenization treatment for 24 h. The specific compression and tensile strength can reach 0.36 and 0.24 GPa cm3/g.

BackgroundThe mosquito,Armigeres subalbatus, mounts a distinctively robust innate immune response when infected with the nematodeBrugia malayi, a causative agent of lymphatic filariasis. In order to mine the transcriptome for new insight into the cascade of events that takes place in response to infection in this mosquito, 6 cDNA libraries were generated from tissues of adult female mosquitoes subjected to immune-response activation treatments that lead to well-characterized responses, and from aging, naïve mosquitoes. Expressed sequence tags (ESTs) from each library were produced, annotated, and subjected to comparative analyses.ResultsSix libraries were constructed and used to generate 44,940 expressed sequence tags, of which 38,079 passed quality filters to be included in the annotation project and subsequent analyses. All of these sequences were collapsed into clusters resulting in 8,020 unique sequence clusters or singletons. EST clusters were annotated and curated manually within ASAP (A Systematic Annotation Package for Community Analysis of Genomes) web portal according to BLAST results from comparisons to Genbank, and theAnopheles gambiaeandDrosophila melanogastergenome projects.ConclusionThe resulting dataset is the first of its kind for this mosquito vector and provides a basis for future studies of mosquito vectors regarding the cascade of events that occurs in response to infection, and thereby providing insight into vector competence and innate immunity.

Mosquito-borne diseases, including dengue, malaria, and lymphatic filariasis, exact a devastating toll on global health and economics, killing or debilitating millions every year (54). Mosquito innate immune responses are at the forefront of concerted research efforts aimed at defining potential target genes that could be manipulated to engineer pathogen resistance in vector populations. We aimed to describe the pivotal role that circulating blood cells (called hemocytes) play in immunity by generating a total of 11,952 Aedes aegypti and 12,790 Armigeres subalbatus expressed sequence tag (EST) sequences from immune response-activated hemocyte libraries. These ESTs collapsed into 2,686 and 2,107 EST clusters, respectively. The clusters were used to adapt the web-based interface for annotating bacterial genomes called A Systematic Annotation Package for Community Analysis of Genomes (ASAP) for analysis of ESTs. Each cluster was categorically characterized and annotated in ASAP based on sequence similarity to five sequence databases. The sequence data and annotations can be viewed in ASAP at https://asap.ahabs.wisc.edu/annotation/php/ASAP1.htm . The data presented here represent the results of the first high-throughput in vivo analysis of the transcriptome of immunocytes from an invertebrate. Among the sequences are those for numerous immunity-related genes, many of which parallel those employed in vertebrate innate immunity, that have never been described for these mosquitoes.

A high-molecular-weight mite allergen Der f11 that was hardly purified for immunotherapy was used to develop the DNA vaccine pDf11. We have shown that vaccination of mice with pDf11 induces Th1 responses characterized by suppression of IgE responses. In the present study, effects of different adjuvants on pDf11 were first studied. Mice receiving pDf11 +/- CpG, bestatin, and bupivacaine had better suppression of IgE responses than those receiving pDf11 +/- lipofectin or alum. Bestatin could greatly boost IgG2a responses. Immunomodulating effects of different adjuvants between protein and DNA vaccines were further elucidated. CpG was the best for both protein and DNA vaccines to profoundly suppress IgE responses, but alum, bestatin and lipofectin were useless for rDf11 to induce IgE inhibition. Neither did the combination of rDf11 and pDf11 have further IgE suppression. In conclusion, CpG is the unique adjuvant for the protein vaccine rDf11 to inhibit IgE responses. In contrast, the DNA vaccine pDf11 +/- CpG, bestatin, or bupivacaine induces profound suppression of IgE responses.