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This study used red mud modified with chitosan (RM/CS) as a novel adsorbent to remove Ni(II) ions from an aqueous solution. The adsorbent was characterized by the techniques of the BET method, X-ray diffraction (XRD), and scanning electron microscopy (SEM) analysis. According to the findings, the surface area of RM/CS is nearly doubled compared to CS, from 68.6 to 105.7 m 2 .g -1 . The Ni(II) batch adsorption of RM/CS was performed as a function of pH value, contact time, and volume of adsorbent. Three isotherm adsorption models (Langmuir, Freundlich, and Sips) and three kinetic models (the pseudo-first-order, the pseudo-second-order, and the intra-diffusion models) were fitted with the experimental data to calculate the maximum adsorption capacity and to estimate the uptake in nature. The Langmuir monolayer adsorption capacity for Nickel (II) is 31.66 mg.g -1 at a pH of 6.0, with an adsorption time of 180 min and a temperature of 323 K. The Ni(II) adsorption on RM/CS is the exothermic process and is controlled by the intra-diffusion model., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Layered group IV monochalcogenides are two-dimensional (2D) semiconducting materials with unique crystal structures and novel physical properties. Here, we report the growth of single crystalline GeS microribbons using the chemical vapor transport process. By using conductive atomic force microscopy, we demonstrated that the conductive behavior in the vertical direction was mainly affected by the Schottky barriers between GeS and both electrodes. Furthermore, we found that the topographic and current heterogeneities were significantly different with and without illumination. The topographic deformation and current enhancement were also predicted by our density functional theory (DFT)-based calculations. Their local spatial correlation between the topographic height and current was established. By virtue of 2D fast Fourier transform power spectra, we constructed the holistic spatial correlation between the topographic and current heterogeneity that indicated the diminished correlation with illumination. These findings on layered GeS microribbons provide insights into the conductive and topographic behaviors in 2D materials.

Abstract: The global market for fuel pellets (FPs) has been steadily growing because of a shift to coal substitutes. However, sustainability and the availability of biomass are the main issues. Various kinds of bio-wastes can be valorized through cutting-edge technologies. In the coffee industry, a valuable organic waste called spent coffee grounds (SCGs) is generated in bulk. SCG can be divided into two components, namely spent coffee ground oil and defatted spent coffee grounds (DSCG). SCG and DSCG can be used to produce FPs with excellent higher heating values. This review highlights that burning FPs composed of 100% SCG is not feasible due to the high emission of NO x . Moreover, the combustion is accompanied by a rapid temperature drop due to incomplete combustion which leads to lower boiler combustion efficiencies and increased carbon monoxide emissions. This was because of the low pellet strength and bulk density of the FP. Mixing SCG with other biomass offers improved boiler efficiency and emissions. Some of the reported optimized FPs include 75% SCG + 20% coffee silverskin, 30% SCG + 70% pine sawdust, 90% SCG + 10% crude glycerol, 32% SCG + 23% coal fines + 11% sawdust + 18% mielie husks + 10% waste paper + 6% paper pulp, and 50% SCG + 50% pine sawdust. This review noted the absence of combustion and emissions analyses of DSCG and the need for their future assessment. Valorization of DSCG offers a good pathway to improve the economics of an SCG-based biorefinery where the extracted SCGO can be valorized in other applications. The combustion and emissions of DSCG were not previously reported in detail. Therefore, future investigation of DSCG in boilers is essential to assess the potential of this industry and improve its economics., Supplementary Information: The online version contains supplementary material available at 10.1007/s10668-022-02361-z., (© The Author(s), under exclusive licence to Springer Nature B.V. 2022.)

Large-scale growth of transition metal dichalcogenides and their subsequent integration with compound semiconductors is one of the major obstacles for two-dimensional materials implementation in optoelectronics applications such as active matrix displays or optical sensors. Here we present a novel transition metal dichalcogenide-on-compound-semiconductor fabrication method that is compatible with a batch microfabrication process. We show how a thin film of molybdenum disulfide (MoS 2 ) can be directly synthesized on a gallium-nitride-based epitaxial wafer to form a thin film transistor array. Subsequently, the MoS 2 thin film transistor was monolithically integrated with micro-light-emitting-diode (micro-LED) devices to produce an active matrix micro-LED display. In addition, we demonstrate a simple approach to obtain red and green colours through the printing of quantum dots on a blue micro-LED, which allows for the scalable fabrication of full-colour micro-LED displays. This strategy represents a promising route to attain heterogeneous integration, which is essential for high-performance optoelectronic systems that can incorporate the established semiconductor technology and emerging two-dimensional materials., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

The concentrations of heavy metal ions found in waterways near industrial zones are often exceed the prescribed limits, posing a continued danger to the environment and public health. Therefore, greater attention has been devoted into finding the efficient solutions for adsorbing heavy metal ions. This review paper focuses on the synthesis of carbon nanotubes (CNTs) from biomass and their application in the removal of heavy metals from aqueous solutions. Techniques to produce CNTs, benefits of modification with various functional groups to enhance sorption uptake, effects of operating parameters, and adsorption mechanisms are reviewed. Adsorption occurs via physical adsorption, electrostatic interaction, surface complexation, and interaction between functional groups and heavy metal ions. Moreover, factors such as pH level, CNTs dosage, duration, temperature, ionic strength, and surface property of adsorbents have been identified as the common factors influencing the adsorption of heavy metals. The oxygenated functional groups initially present on the surface of the modified CNTs are responsible towards the adsorption enhancement of commonly-encountered heavy metals such as Pb 2+ , Cu 2+ , Cd 2+ , Co 2+ , Zn 2+ , Ni 2+ , Hg 2+ , and Cr 6+ . Despite the recent advances in the application of CNTs in environmental clean-up and pollution treatment have been demonstrated, major obstacles of CNTs such as high synthesis cost, the agglomeration in the post-treated solutions and the secondary pollution from chemicals in the surface modification, should be critically addressed in the future studies for successful large-scale applications of CNTs., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

MoS 2 , an emerging material in the field of optoelectronics, has attracted the attention of researchers owing to its high light absorption efficiency, even as an atomically thin layer. However, the covered spectra of the reported MoS 2 -based photodetectors are restricted to the visible range owing to their electronic bandgap (∼1.9 eV). Strain engineering, which modulates the bandgap of a semiconductor, can extend the application coverage of MoS 2 to the infrared spectral range. The shrinkage of the bandgap because of the tensile strain on MoS 2 enhances the photoresponsivity in the visible range and extends its sensing capability beyond its fundamental absorption limit. Herein, we report a graphene/MoS 2 /graphene metal-semiconductor-metal photodetector (PD) array with a strain-modulated photoresponse up to the spectral range of the near-infrared (NIR). The MoS 2 PD array on a flexible substrate was stretched in the biaxial direction to a tensile strain level of 1.19% using a pneumatic bulging process. The MoS 2 -based line-scanning system was implemented by digitizing the output photocurrent of the strained MoS 2 linear array with a low-noise complementary metal-oxide-semiconductor (CMOS) readout integrated circuit (IC) and successfully captured vis-NIR images in foggy conditions. Therefore, we extended the application of the MoS 2 PD array to the NIR regime and demonstrated its use in real-life imaging systems.

Being declared a global emergency, the COVID-19 pandemic has taken many lives, threatened livelihoods and businesses around the world. The energy industry, in particular, has experienced tremendous pressure resulting from the pandemic. In response to such a challenge, the development of sustainable resources and renewable energy infrastructure has demonstrated its potential as a promising and effective strategy. To sufficiently address the effect of COVID-19 on renewable energy development strategies, short-term policy priorities should be identified, while mid-term and long-term action plans should be formulated in achieving the well-defined renewable energy targets and progress towards a more sustainable energy future. In this review, opportunities, challenges, and significant impacts of the COVID-19 pandemic on current and future sustainable energy strategies were analyzed in detail; while drawing from experiences in identifying reasonable behaviors, orientating appropriate actions, and policy implications on the sustainable energy trajectory were also mentioned. Indeed, the question is that whether the COVID-19 pandemic will kill us or provide us with a precious lesson on future sustainable energy development., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 Elsevier Ltd. All rights reserved.)

Always, oil spills do cause serious and dire consequences for the environment, nature, and society that it consumes much time and socio-economic resources to overcome such consequences. Oil spills, hence, posed a big challenge in searching the advanced technologies and devices to recover spilled oil rapidly and efficiently. Indeed, sorbents have been found to play an extremely critical role in the spilled-oil remediation processes. Recently, a large number of various advanced sorbents and sorbent-based oil-collecting devices/technologies have been developed to enhance the oil-recovery capacity. Therefore, it is necessary to have a comprehensive assessment of the application of sorbent-based oil-collecting devices/technologies in recovering spilled oil. Due to this reason, this paper aims to provide a comprehensive review of the advanced technologies of the combination of sorbents and oil-collecting devices in the oil cleanup strategies. Two main oil-collecting devices such as booms and skimmers that could conjunct with sorbents were critically evaluated on the basis of the applicability and technological features, indicating that the capacity of oil spill recovery could achieve 90%. Moreover, oil-storage and oil-collecting devices were also completely mentioned. Last but not least, technical directions, concerns over the application of sorbents in oil recovery, and existing challenges relating to storage, transport, and disposal of used sorbents were discussed in detail. In the future, the automatic process of spilled oil recovery with the conjunction between advanced devices and environmentally friendly high-efficiency sorbents should be further investigated to minimize the environmental impacts, reduce the cost, as well as maximize the collected oil spill.

Enolase (ENO) 1 is a key glycolytic enzyme and important player in tumorigenesis. ENO1 overexpression has been correlated with tumor progression and/or worse prognosis in several solid malignancies. However, data concerning the impact of ENO1 in cancer conflict. The study correlated local and circulating ENO1 protein levels in esophageal cancer (EC) with clinicopathological data, to assess its potential clinical value. ENO1 expression was analyzed by immunohistochemistry in paired tumor and non-tumor tissue samples from 40 EC cases and mucosal biopsies from 45 Barrett's esophagus (BE) cases, plus in plasma from these patients and 25 matched healthy controls. ENO1 was abnormally elevated in cancer-cell cytoplasm in both EC types, in esophageal squamous cell carcinoma and in adenocarcinoma (EAC), increasing significantly with tumor stage progression and the transition from BE to EAC. EAC patients exhibited significantly lower ENO1 plasma concentrations than normal subjects. Neither local nor systemic ENO1 expression levels were significantly associated with overall survival. These results indicate ENO1 as potential biomarker, delineating a population of patients with Barrett's esophagus at high risk of cancer, and as new therapeutic opportunity in EC patient management. However, further confirmation might be necessary., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

For the last decade, two-dimensional transition metal dichalcogenides (TMDCs) have attracted considerable attention due to their unique physical and chemical properties. Novel devices based on these materials are commonly fabricated using the exfoliated samples, which lacks control of the thickness and cannot be scaled. Therefore, the synthesis of large-area TMDC thin films with a high uniformity to advance the field is required. This article reviews the latest advances in the synthesis of wafer-scale thin films using chemical vapor deposition methods. The key factors that determine the electrical performance of TMDCs are introduced, including the interfacial properties and defects. The latest solution-based techniques which suggest the opportunity to obtain large-area TMDC thin films with a low-cost process and the potential applications in electronics and optoelectronics are also discussed. The outlook for future research directions, challenges, and possible development of 2D materials are further discussed.

Adenoviral conjunctivitis is a common epidemic worldwide. In Vietnam, up to 80,000 patients are infected with adenoviral conjunctivitis annually. However, there are few investigations on the pathogenic adenoviruses that cause conjunctivitis. In total, 120 eye-swab samples were collected from patients with viral conjunctivitis symptoms in Hanoi, Vietnam from 2017 to 2019. Human adenoviruse (HAdV) was detected in 67 samples (55.83%) using polymerase chain reaction amplification of at least one of three HAdV-specific marker genes (hexon, penton, and fiber). Of the 67 HAdV samples, 46 samples could be analyzed by all three marker genes. DNA sequence analysis and phylogenetic tree building based on the three marker genes from the 46 HAdV samples revealed five different HAdV types associated with conjunctivitis in Hanoi, including HAdV-3 (4.3%), HAdV-4 (2.2%), HAdV-8 (89.1%), HAdV-37 (2.2%), and a potential recombinant type between types HAdV-8 and HAdV-3 (2.2%). This showed that HAdV-8 was the most common type identified in Hanoi. Complete genome analysis of HAdV-8 isolated from a Vietnamese patient (VN2017) using Sanger sequencing revealed 34 unique nucleotide changes, indicating that the adenovirus continuously accumulates new mutations. Hence, continuous surveillance of HAdV-8 changes in Vietnam is necessary in the future., (© 2020 Wiley Periodicals, Inc.)

Van der Waals heterostructures have attracted increasing interest, owing to the combined benefits of their constituents. These hybrid nanostructures can be realized via epitaxial growth, which offers a promising approach for the controlled synthesis of the desired crystal phase and the interface between van der Waals layers. Here, the epitaxial growth of a continuous molybdenum disulfide (MoS 2 ) film on large-area graphene, which was directly grown on a sapphire substrate, is reported. Interestingly, the grain size of MoS 2 grown on graphene increases, whereas that of MoS 2 grown on SiO 2 decreases with an increasing amount of hydrogen in the chemical vapor deposition reactor. In addition, to achieve the same quality, MoS 2 grown on graphene requires a much lower growth temperature (400 °C) than that grown on SiO 2 (580 °C). The MoS 2 /graphene heterostructure that was epitaxially grown on a transparent platform was investigated to explore its photosensing properties and was found to exhibit inverse photoresponse with highly uniform photoresponsivity in the photodetector pixels fabricated across a full wafer. The MoS 2 /graphene heterostructure exhibited ultrahigh photoresponsivity (4.3 × 10 4 A W -1 ) upon exposure to visible light of a wide range of wavelengths, confirming the growth of a high-quality MoS 2 /graphene heterostructure with a clean interface.

Electronic applications are continuously developing and taking new forms. Foldable, rollable, and wearable displays are applicable for human health care monitoring or robotics, and their operation relies on organic light-emitting diodes (OLEDs). Yet, the development of semiconducting materials with high mechanical flexibility has remained a challenge and restricted their use in unusual format electronics. This study presents a wearable full-color OLED display using a two-dimensional (2D) material-based backplane transistor. The 18-by-18 thin-film transistor array was fabricated on a thin MoS 2 film that was transferred to Al 2 O 3 (30 nm)/polyethylene terephthalate (6 μm). Red, green, and blue OLED pixels were deposited on the device surface. This 2D material offered excellent mechanical and electrical properties and proved to be capable of driving circuits for the control of OLED pixels. The ultrathin device substrate allowed for integration of the display on an unusual substrate, namely, a human hand., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)

To realize basic electronic units such as complementary metal-oxide-semiconductor (CMOS) inverters and other logic circuits, the selective and controllable fabrication of p- and n-type transistors with a low Schottky barrier height is highly desirable. Herein, an efficient and nondestructive technique of electron-charge transfer doping by depositing a thin Al 2 O 3 layer on chemical vapor deposition (CVD)-grown 2H-MoTe 2 is utilized to tune the doping from p- to n-type. Moreover, a type-controllable MoTe 2 transistor with a low Schottky barrier height is prepared. The selectively converted n-type MoTe 2 transistor from the p-channel exhibits a maximum on-state current of 10 µA, with a higher electron mobility of 8.9 cm 2 V -1 s -1 at a drain voltage (V ds ) of 1 V with a low Schottky barrier height of 28.4 meV. To validate the aforementioned approach, a prototype homogeneous CMOS inverter is fabricated on a CVD-grown 2H-MoTe 2 single crystal. The proposed inverter exhibits a high DC voltage gain of 9.2 with good dynamic behavior up to a modulation frequency of 1 kHz. The proposed approach may have potential for realizing future 2D transition metal dichalcogenide-based efficient and ultrafast electronic units with high-density circuit components under a low-dimensional regime., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: To accelerate reductions in neonatal mortality, Viet Nam rolled out early essential newborn care (EENC) using clinical coaching, quality improvement assessments in hospitals, and updated protocols. Da Nang Hospital for Women and Children, a tertiary referral hospital in central Viet Nam, compared outcomes pre- and post-EENC introduction., Methods: Records of live births and NICU admissions were reviewed pre- (November 2013-October 2014) and post- (November 2014-October 2015) EENC implementation. Delivery room practices, NICU admissions and adverse outcomes on NICU admission were compared using descriptive statistics., Findings: A total of 13,201 live births were delivered pre- and 14,180 live births post-EENC introduction. Post-EENC, delivery practice scores, rates of early and prolonged skin-to-skin contact and early breastfeeding rose significantly. There was a significant reduction in risk of NICU admissions (relative risk [RR] 0.68; 95% confidence interval [CI] 0.64-0.71; p  < 0.0001), hypothermia on NICU admission (RR 0.72; 95% CI 0.65-0.81, p  < 0.0001) and sepsis (RR 0.28; 95% CI 0.23-0.35, p  < 0.0001). Exclusive breastfeeding rates in NICU increased from 49% to 88% ( p  < 0.0001) and of kangaroo mother care (KMC) from 52% to 67% ( p  < 0.0001). Reduced formula use resulted in decreased monthly costs., Interpretation: EENC introduction, including staff coaching, quality improvement assessments and changes in hospital protocols and environments, were associated with improved clinical practices, reduced NICU admissions, admissions with hypothermia and sepsis and increased rates of exclusive breastfeeding and KMC in the NICU., Funding: Data collection was funded by the World Health Organization Western Pacific Regional Office and Newborns Vietnam., Outstanding Questions: •What is the impact of the package of early essential newborn care interventions on newborn mortality?•What are the total direct and indirect cost savings of early essential newborn care implementation?•What is the cost effectiveness of kangaroo mother care for preterm and low birth weight babies?•What strategies can help reduce unnecessary cesarean sections in hospitals?