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The purpose of this paper is to investigate a new inertial self-adaptive iterative algorithm for solving variational inequalities over the solution set of the split variational inequality problem with multiple output sets in real Hilbert spaces. The strong convergence result is given under some mild conditions widely used in the convergence analysis. Our algorithm is accelerated by the inertial technique and eliminates the dependence on the norm of the transformation operators and the strongly monotone and Lipschitz continuous constants of the involved operator. Two applications in the network bandwidth allocation problem and the image classification problem are shown, and some numerical experiments are presented to show the advantages of the proposed algorithm. [ABSTRACT FROM AUTHOR]

The advent of three-dimensional (3D) bioprinting offers a feasible approach to construct complex structures for soft tissue regeneration. Carboxymethyl cellulose (CMC) has been emerging as a very promising biomaterial for 3D bioprinting. However, due to the inability to maintain the post-printed stability, CMC needs to be physically blended and/or chemically crosslinked with other polymers. In this context, this study presents the combination of CMC with xanthan gum (XG) and hyaluronic acid (HA) to formulate a multicomponent bioink, leveraging the printability of CMC and XG, as well as the cellular support properties of HA. The ionic crosslinking of printed constructs with iron(III) via the metal-ion coordination between ferric cations and carboxylate groups of the three polymers was introduced to induce improved mechanical strength and long-term stability. Moreover, immortalized human epidermal keratinocytes (HaCaT) and human foreskin fibroblasts (HFF) encapsulated within iron-crosslinked printed hydrogels exhibited excellent cell viability (more than 95%) and preserved morphology. Overall, the presented study highlights that the combination of these three biopolymers and the ionic crosslinking with ferric ions is a valuable strategy to be considered for the development of new and advanced hydrogel-based bioinks for soft tissue engineering applications. [ABSTRACT FROM AUTHOR]

In this paper, two relaxed CQ algorithms with non-inertial and inertial steps are proposed for solving the split feasibility problems with multiple output sets (SFPMOS) in infinite-dimensional real Hilbert spaces. The step size is determined dynamically without requiring prior information about the operator norm. Furthermore, the proposed algorithms are proven to converge strongly to the minimum-norm solution of the SFPMOS. Some applications of our main results regarding the solution of the split feasibility problem are presented. Finally, we give two numerical examples to illustrate the efficiency and implementation of our algorithms in comparison with existing algorithms in the literature. [ABSTRACT FROM AUTHOR]

The research community has witnessed an exceptional increase in exploring graphene related two-dimensional materials (GR2Ms) in many innovative applications and emerging technologies. However, simple, low-cost, sustainable, and eco-friendly methods to manufacture large quantities and high-quality GR2Ms still remain an unsolved challenge. To address limitations of conventional wet chemical-based exfoliation methods using graphite resources, the top-down irradiation approach has proven to be an ultrafast, effective, and environmentally friendly technology for scalable exfoliation, production, and processing of GR2Ms providing new properties for emerging applications. Significant advancements have been made for preparation of broad range of GR2Ms from graphite, such as graphene, graphene oxide, and reduced graphene oxide, and their doped, functionalized and modified forms over the past two decades, thanks to the availability of photon and ion irradiation techniques, such as microwave, infrared, ultraviolet, solar, x-ray, gamma, laser, and plasma. This review presents recent advances on the application of these various irradiation techniques and highlights their mechanism, differences in properties of prepared GR2Ms, and their advantages and disadvantages in comparison with other conventional methods. The review provides an insight into the irradiation strategies and their prospective applications to produce, at a large scale, low-cost, high-quality GR2Ms for practical applications in transparent electrodes, optoelectronic devices, sensors, supercapacitors, protective coatings, conductive inks, and composites. [ABSTRACT FROM AUTHOR]

Herein, the visible light‐photocatalytic performance of synthesized ZnO/Gr composite materials with different Gr content under various conditions, i.e., pH, dye concentration, and different scavengers (to understand the photocatalytic activity mechanism) is systematically investigated. Photocatalytic performance is evaluated with the degradation of methylene blue (MB) in solution under sunlight irradiation. The presence of graphene (Gr) in the ZnO/Gr composites shows enhanced photocatalytic activity compared to pure ZnO under natural sunlight illumination. The highest photodegradation efficiency of ≈94% when the content of Gr is 1 wt% in comparison to ≈76% for the pure ZnO, corresponding to reaction rate constants of 0.01038 and 0.00615 min−1, respectively. Compared to recent publications, the degradation efficiency is high with relatively high dye concentration, low catalyst amount, and large solution volume. The enhanced visible light absorption and the reduction of bandgap value are attributed to the enhanced photocatalytic properties of the hybridized composite. Moreover, the investigation of the effect of scavenger substances shows that H2O2 strongly enhanced their photocatalytic ability, suggesting that holes (h+) contribute as the reactive agent in the photodegradation process. [ABSTRACT FROM AUTHOR]

Occult hepatitis B infection (OBI) is characterized by the presence of low levels of hepatitis B virus (HBV) DNA and undetectable HBsAg in the blood. The prevalence of OBI in blood donors in Asia ranges from 0.013% (China) to 10.9% (Laos), with no data available from Vietnam so far. We aimed to investigate the prevalence of OBI among Vietnamese blood donors. A total of 623 (114 women and 509 men) HBsAg-negative blood donors were screened for anti-HBc and anti-HBs by ELISA assays. In addition, DNA from sera was isolated and nested PCR was performed for the HBV surface gene (S); a fragment of the S gene was then sequenced in positive samples. The results revealed that 39% (n = 242) of blood donors were positive for anti-HBc, and 70% (n = 434) were positive for anti-HBs, with 36% (n = 223) being positive for both anti-HBc and anti-HBs. In addition, 3% of blood donors (n = 19) were positive for anti-HBc only, and 34% (n = 211) had only anti-HBs as serological marker. A total of 27% (n = 170) were seronegative for any marker. Two of the blood donors (0.3%) were OBI-positive and sequencing revealed that HBV sequences belonged to HBV genotype B, which is the predominant genotype in Vietnam. [ABSTRACT FROM AUTHOR]

Wearable sensors are currently one of the top emerging areas with enormous growth potential. Low‐cost fabrication techniques using simple and scalable printing technologies are making a significant impact on their development. Recent advances in high‐performance gas/vapor sensors based on carbon nanomaterials have shown potential applications ranging from disease diagnostics to environmental monitoring and defences. Herein, a hybrid sensing material of 1D carbon nanotubes (CNTs) and 2D graphene is developed, and a conductive ink is formulated, which is applied for fabricating a nitrogen dioxide (NO2) gas sensor array within a compact design utilizing extrusion printing. To improve NO2‐sensing performance and optimal operating temperature, a reverse‐side layer is designed, which combines MXene and poly(3,4‐ethylenedioxythiophene)‐doped poly(styrene sulfonate) (PEDOT:PSS), and functions as a Joule heater. The printed CNT–graphene‐based sensor with an embedded MXene/PEDOT:PSS heater is capable of detecting trace amounts of NO2 gas (1 ppm) at 65 °C. The sensor is able to distinguish between various gases/volatile organic compounds and target NO2 gas based on their chemical affinities. The printed CNT–graphene sensor array also demonstrates a high‐level of recoverability, satisfied stability, durability, and reproducibility, which render this sensor a suitable candidate for practical applications. [ABSTRACT FROM AUTHOR]

Wearable sensors are currently one of the top emerging areas with enormous growth potential. Low‐cost fabrication techniques using simple and scalable printing technologies are making a significant impact on their development. Recent advances in high‐performance gas/vapor sensors based on carbon nanomaterials have shown potential applications ranging from disease diagnostics to environmental monitoring and defences. Herein, a hybrid sensing material of 1D carbon nanotubes (CNTs) and 2D graphene is developed, and a conductive ink is formulated, which is applied for fabricating a nitrogen dioxide (NO2) gas sensor array within a compact design utilizing extrusion printing. To improve NO2‐sensing performance and optimal operating temperature, a reverse‐side layer is designed, which combines MXene and poly(3,4‐ethylenedioxythiophene)‐doped poly(styrene sulfonate) (PEDOT:PSS), and functions as a Joule heater. The printed CNT–graphene‐based sensor with an embedded MXene/PEDOT:PSS heater is capable of detecting trace amounts of NO2 gas (1 ppm) at 65 °C. The sensor is able to distinguish between various gases/volatile organic compounds and target NO2 gas based on their chemical affinities. The printed CNT–graphene sensor array also demonstrates a high‐level of recoverability, satisfied stability, durability, and reproducibility, which render this sensor a suitable candidate for practical applications. [ABSTRACT FROM AUTHOR]

Plasma electrolytic oxidation (PEO) is a well-established technique for the treatment of titanium-based materials. The formed titania-PEO surface can improve the osseointegration properties of titanium implants. Nevertheless, it can not address bacterial infection problems associated with bone implants. Recently, 2-dimensional (2D) materials such as graphene oxide (GO), MXene, and hexagonal boron nitride (hBN) have received considerable attention for surface modifications showing their antibacterial properties. In this paper, a comparative study on the effect of partial deposition of these three materials over PEO titania substrates on the antibacterial efficiency and bioactivity is presented. Their partial deposition through drop-casting instead of continuous film coating is propsed to simultaneously address both antibacterial and osseointegration abilities. Our results demonstrate the dose-dependent nature of the deposited antibacterial agent on the PEO substrate. GO–PEO and MXene–PEO samples showed the highest antibacterial activity with 70 (±2) % and 97 (±0.5) % inactivation of S. aureus colonies in the low concentration group, respectively. Furthermore, only samples in the higher concentration group were effective against E. coli bacteria with 18 (±2) % and 17 (±4) % decrease in numbers of colonies for hBN–PEO and GO–PEO samples, respectively. Moreover, all antibacterial samples demonstrated acceptable bioactivity and good biocompatibility, making them a considerable candidates for the next generation of antibacterial titanium implants. [ABSTRACT FROM AUTHOR]

We report a flexible and highly efficient wideband slot antenna based on a highly conductive composite of poly(3,4-ethylenedioxythiophene) (PEDOT) and N-doped reduced graphene oxide (N-doped rGO) for wearable applications. The high conductivity of this hybrid material with low sheet resistance of 0.56 Ω/square, substantial thickness of 55 μm, and excellent mechanical resilience (<5.5% resistance change after 1000 bending cycles) confirmed this composite to be a suitable antenna conductor. The antenna achieved an estimated conduction efficiency close to 80% over a bandwidth from 3 to 8 GHz. Moreover, the successful operation of a realized antenna prototype has been demonstrated in free space and as part of a wearable camera system. The read range of the system was measured to be 271.2 m, which is 23 m longer than that of the original monopole antennas provided by the supplier. The synergistic effects between the dual conjugated structures of N-doped rGO and PEDOT in a single composite with fine distribution and interfacial interactions are critical to the demonstrated material performance. The N-doped rGO sheet reinforces the mechanical stability whereas the PEDOT functions as additive and/or binder, leading to an improved electrical and mechanical performance compared to that of the graphene and PEDOT alone. This high-performing nanocomposite material meets requirements for antenna design and opens the door for diverse future non-metallic flexible electronic device developments. [ABSTRACT FROM AUTHOR]

Nitrogen-doped carbon hybridized nanodiamond (N-doped C@ND) materials have been developed and used as an electrocatalytic for oxygen reduction reactions (ORRs). The polymerized ionic liquids are employed to modify NDs and then subjected to thermal annealing at 600 °C, resulting in a high concentration of N-doped (9.33 at.%) carbon frameworks attached on the ND surface. This N-doped C@ND material provides a highly active mesoporous structure (4 nm pore) with a high surface area (366 m2 g−1) and allows for enhancement of catalytic performance compared to pure NDs. The N-doped C layers altered the electroneutrality of NDs, creating favourable charged sites for oxygen adsorption, thus weakening the O–O bond strength to facilitate ORR activity. Having a predominant four-electron transfer pathway with a total electron transfer number of 3.44–3.88 in the potential region of 0.1–0.8 VRHF, the N-doped C@ND-based catalyst materials performed well as a catalyst for the ORR in the alkaline medium. This affordable material and simple process will find potential application in clean energy generation and storage, durable fuel cells and metal–air batteries. [ABSTRACT FROM AUTHOR]

The coexistence of multiple toxic water pollutants (heavy metals, organic dyes, oils, and organic solvents) limits the sustainable supply of clean water worldwide and urges the development of advanced water purification technology that can remove these contaminants simultaneously. Since its discovery, graphene‐based materials have gained substantial attention toward development of new‐generation sorbents for water purification. Despite several recently published reviews on water purification technology using graphene and its derivatives, there is still a gap in the review considering multiple water‐pollutant remediation using advanced graphene materials. In this review, in the first instance, a comparative structure–function–performance relationship between graphene‐based sorbents and the multipollutants in water is established. A fundamental correlation is made between the sorption performance for diverse pollutants in water with the more specific adsorption properties (surface area, pore size, type of functional groups, C/O, C/N, and C/S atomic ratio) of advanced graphene sorbents. Second, the underlying interaction mechanisms are uncovered between different classes of water pollutants using single graphene‐based sorbents. Third, the rational design of advanced multipollutant sorbents based on graphene is elaborated. The reality, challenges, and opportunities of advanced graphene materials as emerging sorbents for sustainable water purification technology are finally presented in the last section. [ABSTRACT FROM AUTHOR]

The valorization of onion-like carbon nanoparticles (OCNPs) from pollutant soot collected from diesel engine exhaust could be a promising and sustainable approach to develop percolated conductive networks in a poly(lactic acid) (PLA) matrix, which could be used for the design of conductive polymer nanocomposite (CPC)-based quantum resistive sensors (QRS). The aim of the present study is to incorporate these waste materials in the field of structural health monitoring (SHM) of biocomposites. Here, OCNPs have been used in the formulation of QRS and further integrated into unidirectional flax fibers and PLA composites for SHM trials without altering their mechanical properties. QRS transducers made of 1 wt% OCNPs dispersed into a PLA matrix have been prepared via an in situ spray layer-by-layer (sLbL) process during the fabrication of flax–PLA composites by film stacking under vacuum conditions. Their in situ sensing of strain and damage was evaluated by submitting the flax–PLA unidirectional composite samples to various incremental and simultaneous loading–unloading cycles. Most importantly, the piezo-resistive behavior of the OCNP-based QRS has been found to be reproducible, and it exhibits large-amplitude signals with a gauge factor of 6 ± 2, which is two to three times larger than that of commercial strain sensors. Additionally, these waste-derived OCNPs possess interesting ferromagnetic properties at room temperature. [ABSTRACT FROM AUTHOR]

Bioprinting is an emerging powerful fabrication method, which enables the rapid assembly of 3D bioconstructs with dispensing cell-laden bioinks in pre-designed locations. However, to translate this technology into real applications, there are still a number of challenges that need to be addressed. First, the current inks are generally composed of polymeric materials with poor electrical conductivity that mismatches with the native tissue environment. The second challenge associated with the 3D bioprinting of hydrogel-based bioinks is the fabrication of anatomical-size constructs without any loss of shape fidelity and resolution. To address these challenges, in this work, we introduced a biocompatible bioink associated with current 3D bioprinting by combining methylcellulose and kappa-carrageenan (MC/κCA) hydrogels with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) conducting polymers. The prepared ink exhibited highly thixotropic behaviour, which could be tuned via changing the concentration of MC and κCA to obtain easy printing with high shape fidelity. The ink was able to fabricate physiological-scale constructs without requiring a secondary support bath. In addition, varying the concentration of PEDOT:PSS could control the electrical conductivity of the ink. Moreover, the encapsulated human embryonic kidney 293 (HEK-293) cells in bulk hydrogels and 3D bioprinted structures maintained high cell viability (>96%) over a week, confirming the in vitro biocompatibility of the ink. Overall, these findings indicate that the MC/κCA/PEDOT:PSS bioink can be promising in biomedical applications, which improved the electroconductivity of bioinks and can exploit the advantage of conductive polymers in the 3D bioprinting technology. [ABSTRACT FROM AUTHOR]

Rapid depletion of fossil fuel and increased energy demand has initiated a need for an alternative energy source to cater for the growing energy demand. Fuel cells are an enabling technology for the conversion of sustainable energy carriers (e.g., renewable hydrogen or bio-gas) into electrical power and heat. However, the hazardous raw materials and complicated experimental procedures used to produce electro-catalysts for the oxygen reduction reaction (ORR) in fuel cells has been a concern for the effective implementation of these catalysts. Therefore, environmentally friendly and low-cost oxygen reduction electro-catalysts synthesised from natural products are considered as an attractive alternative to currently used synthetic materials involving hazardous chemicals and waste. Herein, we describe a unique integrated oxygen reduction three-dimensional composite catalyst containing both nitrogen-doped carbon fibers (N-CF) and carbon microspheres (N-CMS) synthesised from apricot sap from an apricot tree. The synthesis was carried out via three-step process, including apricot sap resin preparation, hydrothermal treatment, and pyrolysis with a nitrogen precursor. The nitrogen-doped electro-catalysts synthesised were characterised by SEM, TEM, XRD, Raman, and BET techniques followed by electro-chemical testing for ORR catalysis activity. The obtained catalyst material shows high catalytic activity for ORR in the basic medium by facilitating the reaction via a four-electron transfer mechanism. [ABSTRACT FROM AUTHOR]

Iron oxide nanoparticles have been extensively used for energy production in fuel cells; however, the different phases of iron oxide have not been adequately investigated for their effect on the oxygen reduction reaction (ORR). The low temperature synthesis of four kinds of iron oxide nanoparticles with different phases was incorporated inside 3D reduced graphene oxide (rGO) aerogels and their electrochemical, catalytic and electron transfer properties were determined for ORR. The results showed that, at low potentials (0.20 V), rGO composites containing magnetite, maghemite and goethite catalyse ORR via four-electron transfer kinetics while hematite facilitated two-electron transfer kinetics. At higher potentials (0.70 V), all four catalysts proceeded via a two-electron pathway. [ABSTRACT FROM AUTHOR]

Development of next-generation sensor devices is gaining tremendous attention in both academia and industry because of their broad applications in manufacturing processes, food and environment control, medicine, disease diagnostics, security and defense, aerospace, and so forth. Current challenges include the development of low-cost, ultrahigh, and user-friendly sensors, which have high selectivity, fast response and recovery times, and small dimensions. The critical demands of these new sensors are typically associated with advanced nanoscale sensing materials. Among them, graphene and its derivatives have demonstrated the ideal properties to overcome these challenges and have merged as one of the most popular sensing platforms for diverse applications. A broad range of graphene assemblies with different architectures, morphologies, and scales (from nano-, micro-, to macrosize) have been explored in recent years for designing new high-performing sensing devices. Herein, this study presents and discusses recent advances in synthesis strategies of assembled graphene-based superstructures of 1D, 2D, and 3D macroscopic shapes in the forms of fibers, thin films, and foams/aerogels. The fabricated state-of-the-art applications of these materials in gas and vapor, biomedical, piezoresistive strain and pressure, heavy metal ion, and temperature sensors are also systematically reviewed and discussed, and their sensing performance is compared. [ABSTRACT FROM AUTHOR]

This paper is devoted to studying the maximal and minimal solutions for the interval-valued functional integrodifferential equations (IFIDEs) under generalized Hukuhara differentiability by the method of upper and lower solutions and monotone iterative technique. Some examples are given to illustrate the results. [ABSTRACT FROM AUTHOR]

Conductive nanostructured composites combining an epoxy polymer and graphene have been explored for applications such as electrostatic-dissipative, anti-corrosive, and electromagnetic interference (EMI) shielding, stealth composite coating and specifically for sensors. For many of these applications, the limits of dispersion of graphene nanosheets and the interface between fillers and matrices have affected their electrical, structural and mechanical properties. To address these problems, we present the use of a dimethylbenzamide (DMBA)-based hardener to modify the surface of reduced graphene oxide (RGO) and create a 3D architecture with a micro-porous structure. DMBA is applied to provide two functions: one is to act as a stabilizer to avoid restacking of graphene sheets during the reduction process, and the second is to provide a linkage between RGO and epoxy for the formation of homogeneous nanocomposites. Thin films of conductive polymer graphene composites (CPCs) were prepared using a simple doctor blade method, while piezoresistive sensors were prepared by spraying to demonstrate their application for mechanical strain sensing. The electrical properties of the composites as a function of graphene fillers were shown to significantly increase from 1012Ω sq−1 for neat epoxy to 106Ω sq−1 for 2 wt% RGO in epoxy composites, while the modulus calculated using nanoindentation exhibited a 43.3% enhancement from 3.56 GPa for epoxy to 6.28 GPa for the composites containing 2 wt% graphene. The results of piezo-resistive performance for mechanical strain sensing under both static and dynamic strain modes showed good sensitivity with a gauge factor (GF) of 12.8 and a fast response time of 20 milliseconds. A minor loading/unloading hysteresis loop after 1000 cycles indicated good reversibility and reproducibility of the sensors. Excellent reproducibility, long-term stability and reliability of the sensing devices are confirmed working without decay of sensitivity after a 6-month exposure to ambient atmosphere. The results obtained suggest that these types of piezo-resistive sensors based on RGO/epoxy CPCs due to their simple, scalable and low cost production could lead to the development of high-performance mechanical strain sensors for a broad range of applications including real-time monitoring, wearable electronics, and structural health monitoring (SHM). [ABSTRACT FROM AUTHOR]

The membrane phospholipid phosphatidylserine is exposed on the cell surface during apoptosis and acts as an eat-me signal in the phagocytosis of apoptotic cells in mammals and nematodes. However, whether this is also true in insects was unclear. When milk fat globule-epidermal growth factor 8, a phosphatidylserine-binding protein of mammals, was ectopically expressed in Drosophila, the level of phagocytosis was reduced, whereas this was not the case for the same protein lacking a domain responsible for the binding to phosphatidylserine. We found that the extracellular region of Draper, an engulfment receptor of Drosophila, binds to phosphatidylserine in an enzyme-linked immunosorbent assay-like solid-phase assay and in an assay for surface plasmon resonance. A portion of Draper containing domains EMI and NIM located close to the N-terminus was required for binding to phosphatidylserine, and a Draper protein lacking this region was not active in Drosophila. Finally, the level of tyrosine-phosphorylated Draper, indicative of the activation of Draper, in a hemocyte-derived cell line was increased after treatment with phosphatidylserine-containing liposome. These results indicated that phosphatidylserine serves as an eat-me signal in the phagocytic removal of apoptotic cells in Drosophila and that Draper is a phosphatidylserine-binding receptor for phagocytosis. [ABSTRACT FROM AUTHOR]

Hybrid materials of Fe3O4-decorated reduced graphene oxide (Fe3O4-RGO) and poly(3,4-ethylenedioxythiophene) (PEDOT) were prepared by poly(ionic liquid)-mediated hybridization. In this hybrid material, poly(ionic liquid) was found to perform multiple roles for: (1) stabilizing Fe3O4-RGO against aggregation in the reaction medium, (2) transferring Fe3O4-RGO nanomaterials from aqueous into organic phase, and (3) associating Fe3O4-RGO nanomaterials with PEDOT. The hybrid materials of Fe3O4-RGO with PEDOT showed the lowest surface resistivity of 80 Ω sq−1 at an RGO-Fe3O4 loading of 1 wt %, and exhibited superparamagnetic behavior with an electromagnetic interference shielding effectiveness of 22 dB. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 [ABSTRACT FROM AUTHOR]

Functionalization of pristine graphene to achieve high water dispersibility remains as a key obstacle owing to the high hydrophobicity and absence of reactive functional groups on the graphene surface. Herein, a green and simple modification approach to prepare highly dispersible functionalized graphene via thermal thiol-ene click reaction was successfully demonstrated on pristine graphene. Specific chemical functionalities (–COO, –NH2 and –S) on the thiol precursor (L-cysteine ethyl ester) were clicked directly on the sp2 carbon of graphene framework with grafting density of 1 unit L-cysteine per 113 carbon atoms on graphene. This functionalized graphene was confirmed with high atomic content of S (4.79 at % S) as well as the presence of C–S–C and N–H species on the L-cysteine functionalized graphene (FG-CYS). Raman spectroscopy evidently corroborated the modification of graphene to FG-CYS with an increased intensity ratio of D and G band, ID/IG ratio (0.3 to 0.7), full-width at half-maximum of G band, FWHM [G] (20.3 to 35.5) and FWHM [2D] (64.8 to 90.1). The use of ethanol as the reaction solvent instead of common organic solvents minimizes the chemical hazards exposure to humans and the environment. This direct attachment of multifunctional groups on the surface of pristine graphene is highly demanded for graphene ink formulations, coatings, adsorbents, sensors and supercapacitor applications. [ABSTRACT FROM AUTHOR]

Macroporous carbon materials (MCMs) are used extensively for many electrocatalytic applications, particularly as catalysts for oxygen reduction reactions (ORRs)—for example, in fuel cells. However, complex processes are currently required for synthesis of MCMs. We present a rapid and facile synthetic approach to produce tailored MCMs efficiently via pyrolysis of sulfonated aniline oligomers (SAOs). Thermal decomposition of SAO releases SO2 gas which acts as a blowing agent to form the macroporous structures. This process was used to synthesise three specifically tailored nitrogen (N)-doped MCM catalysts: N-SAO, N-SAO (phenol formaldehyde) (PF) and N-SAO-reduced graphene oxide (rGO). Analysis using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the formation of macropores (100–350 µm). Investigation of ORR efficacy showed that N-SAOPF performed with the highest onset potential of 0.98 V (vs. RHE) and N-SAOrGO showed the highest limiting current density of 7.89 mAcm−2. The macroporous structure and ORR efficacy of the MCM catalysts synthesised using this novel process suggest that this method can be used to streamline MCM production while enabling the formation of composite materials that can be tailored for greater efficiency in many applications. [ABSTRACT FROM AUTHOR]

Tidal inlets along the central coast of Vietnam are located in a microtidal, wave-dominated coastal environment. In addition, the Vietnam coast is highly influenced by the seasonal monsoon regime, which is characterized by large northeast waves from October to March and calm southeast waves from April to September every year. Consequently, the tidal inlet entrance morphologies often suffer from a dynamic seasonal evolution due to distinct differences in the direction of wave-induced longshore sediment transport (LST) between the two monsoon seasons. The migration or closure of tidal inlets causes a lot of problems for socio-economic development in the region since these are the main reasons leading to an increase in the risk of coastal flooding and the obstruction of navigation. This paper presents a comprehensive study of the morphological evolutions of natural tidal inlets on the central coast of Vietnam using long-term remote sensing data sets and by the Delft3D numerical model. Surprisingly, the estimated LST rates from the former method are in an order of magnitude agreement with the results from the latter one for all of the areas in this study. Based on the conservation equation for sand and comprehensive data collection, a new simple empirical formula for predicting the sand spit elongation rate as a function of the sand spit width is developed. Although the breaching of sand spit might happen during an extreme flood event at some tidal inlets, the growth rate of the spit before and after the breaching is almost unchanged. These findings are very useful information for supporting the local coastal authorities to find better management solutions in terms of sustainable development. [ABSTRACT FROM AUTHOR]

Well-defined sulfonated aniline oligomer (SAO) microstructures with rod and flake morphologies were successfully synthesized using an aniline and oxidant with a molar ratio of 10:1 in ethanol and acidic conditions (pH 4.8). The synthesized oligomers showed excellent dispersibility and assembled as well-defined structures in contrast to the shapeless aggregated material produced in a water medium. The synergistic effects among the monomer concentration, oxidant concentration, pH, and reaction medium are shown to be controlling parameters to generate SAO microstructures with distinct morphologies, whether micro sheets or micro rods. [ABSTRACT FROM AUTHOR]

A correction to the article "Electromagnetic properties of Fe3O4-Functionalized Graphene and Its Composites with a Conducting Polymer," that was published online on June 5, 2013 issue is presented.