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Falls risk is often assessed without considering exposure to risk. We examined the risk factors associated with falls in those with greater and lower levels of daily step count. Falls were recorded over 12 months using bimonthly calendars in community-dwelling older people (mean age 72.0, SD 6.9). Daily step count was measured using a pedometer worn consecutively for 7 days. A cut score of

High pressure or strain is an effective strategy for generating phase transformations in van der Waals (vdW) layered materials without introducing defects, but this approach remains difficult to perform consistently. We present a scalable and facile method for achieving phase transformation in vdW materials, wherein solid vdW materials are subject to internal thermal stress within a molten metal mantle as it undergoes cooling. This internal thermal stress is principally the product of differential thermal expansion between mantle and core and can be tuned by the mantle material and temperature conditions. We validated this approach by achieving phase transformation of red phosphorus to black phosphorus, and metallic 1T'- to semiconducting 2H-MoTe

In today’s modern world wireless and mobile devices have become almost indispensable. As a result human beings are constantly exposed to electromagnetic radiation emanating from these devices which can be harmful for the health. The effect of electromagnetic radiation is higher when we are close to the radiating device, so it is important that a mechanism is developed that will reduce the effect of these radiations and analyze the electromagnetic waves. Finite Difference Time Domain (FDTD) is the effective method to simulate and analyze for positive refractive index on Metamaterial. The simulation environment is Opti-wave used to design perfectly matched layer (PML) structure. The anisotropic and inhomogeneous electric permittivity and magnetic permeability of the right handed metamaterial are presented and transformed to fit the input requirements of the applied finite element solver.

Supercapacitor is an imminent potential energy storage system, and acts as a booster to the batteries and fuel cells to provide necessary power density. In the last decade, carbon and carbonaceous materials, conducting polymers and transition metal oxide/hydroxide based electrode materials have been made to show a remarkable electrochemical performance. Rare-earth materials have attracted significant research attention as an electrode material for supercapacitor applications based on their physicochemical properties. In this review, rare earth metals, rare earth metal oxides/hydroxides, rare-earth metal chalcogenides, rare-earth metal/carbon composites and rare-earth metal/metal oxide composites based electrode materials are discussed for supercapacitors. We also discuss the energy chemistry of rare-earth metal-based materials. Besides the factors that affect the performance of the electrode materials, their evaluation methods and supercapacitor performances are discussed in details. Finally, the future outlook in rare-earth-based electrode materials is revealed towards its current developments for supercapacitor applications.

Two-dimensional (2D) transition metal dichalcogenides (TMDs) and their heterostructures have attracted significant interest in both academia and industry because of their unusual physical and chemical properties. They offer numerous applications, such as electronic, optoelectronic, and spintronic devices, in addition to energy storage and conversion. Atomic and structural modifications of van der Waals layered materials are required to achieve unique and versatile properties for advanced applications. This review presents a discussion on the atomic-scale and structural modifications of 2D TMDs and their heterostructures

Herein, we report morphology controlled growth of layered V2O5 on V2C by the oxidation of V-MXenes at different temperatures and used it as a cathode material for Zn-ion batteries (ZIBs). Hence, the V2O5 nanoparticles are uniformly grown on the V2C nanosheets with interlinked disordered carbon which provide fast diffusion and high rate performance in aqueous zinc-ion batteries.

The Ni-MoSe2 nanocomposite coating was successfully prepared on mild steel specimen using pulse reverse current technique by varying its duty cycle and frequency at the fixed concentration of 2.5 g/ L of MoSe2 nanoparticles in Watt's nickel plating bath. The surface morphology and crystal orientation of nanocomposite coatings were investigated by FE-SEM and XRD, respectively. The influence of duty cycles on the co-deposition and microhardness of Ni-MoSe2 nanocomposite coatings have been evaluated. The 60% duty cycle exhibited better crystal orientation with excellent strengthening effect due to the refinement of Ni. The Tafel polarization and electrochemical impedance studies were performed for Ni-MoSe2 nanocomposite coatings in 3.5 wt% of NaCl solution. These results revealed that the incorporation of MoSe2 in nickel matrix has improved mechanical and corrosion resistance properties.

A significant number of adolescents have difficulty during student life and suffer with anxiety disorders that go undetected and untreated. The lack of data exists in this arena in India. This study aimed to assess anxiety disorders among adolescent students in urban and rural areas and compared the differences between these two locations. A cross-sectional, comparative study was carried out among 462 adolescents studying in rural and urban Government schools using stratified cluster random sampling. Data collected on a pre-designed proforma on demographic parameters and used the Screen for Child Anxiety Related Emotional Disorders (SCARED) scale for detecting anxiety disorders. Out of 462 subjects, females outnumbered males (n = 237, 51.3 %). The mean age of the sample was 15.85+/-0.7 (years); 167 (36 %) subjects had anxiety disorders. All specific anxiety disorders except 'school avoidance' were significantly more in urban school students than in rural students (66.5 % vs. 33.5 %). In a binary logistic regression model, gender (female > male), and locality (urban student > rural student) were significant predictors of the presence of anxiety disorder in this adolescent sample. Adolescent students from the urban schools had a higher prevalence of any anxiety disorder, as well as for specific sub-types than the students from the rural schools.

Herein, we report morphology controlled growth of layered V

Molybdenum selenide (MoSe2) nanosheets are prepared by a simple and facile sonochemical route. To optimize the synthesis process, the sonication is tested at three different time durations (15, 30 and 45 min) with a constant power of 500 W. In order to improve the electrochemical performance of the exfoliated MoSe2 nanosheets, we report the hybridization of 2D-MoSe2 with 2D-graphene by a simple solvothermal method. The exfoliated MoSe2 nanosheets are perpendicularly oriented on the surface of the graphene nanosheets. These MoSe2 nanosheet edges have a large number of electrochemically active sites, and the graphene sheets provide effective mass transportation of ions at the electrode–electrolyte interface. Cyclic voltammetry reveals the pseudocapacitive behaviour of a MoSe2/graphene nanohybrid based electrode. From galvanostatic charge–discharge studies, the specific capacitance is found to be 945 F g−1 at a current density of 1 A g−1. An asymmetric supercapacitor (ASC) device is fabricated, which delivers a specific capacitance of 75 F g−1 (@1 A g−1) with an energy density of 26.6 W h kg−1 and a power density of 0.8 kW kg−1, and it retains 88% of its capacitance even after 3000 cycles.

Ni(OH)2 is recognized as a good electrode material for supercapacitors, but it suffers from capacitance decrease with repeated cycles at high current density. To enhance its electrochemical performance even at high current density, a newer two dimensional molybdenum diselenide – nickel hydroxide nanohybrid (2D MoSe2-Ni(OH)2) have been prepared by a simple one-step hydrothermal synthesis. The 2D MoSe2-Ni(OH)2 nanohybrid have an excellent electrochemical properties due to their synergistic effect. This 2D-2D hybrid electrode exhibits a higher specific capacitance of 1175 F g−1 than Ni(OH)2 nanosheets (933 F g−1) at 1 A g−1 and also maintains a high rate capability of 85.6% at 10 A g−1. In addition, the 2D MoSe2-Ni(OH)2 nanohybrid based asymmetric supercapacitor (ASC) is fabricated and provides a high energy density of 43 Wh kg−1, high power density of 8181 W kg−1 with the capacitance retention of 85% even after 5000 cycles at a high current density of 1 A g−1. When two ASC devices are assembled in series and then charged for 1 min, gives power to light-emitting-diode for more than 3 min suggesting the great significant of the prepared 2D MoSe2-Ni(OH)2 nanohybrid for excellent energy storage.

The development of Zinc-ion batteries (ZIBs) has been in focus for quite some time compelled by poor effectiveness and lower cycle stability, primarily due to slow ion diffusion kinetics and design deformity of cathode materials. Developing innovative cathode materials with high conductivity and stability may be an alternative means of solving these issues. Here, a basic one-step hydrothermal approach is used to synthesize marigold-like reduced graphene oxide (rGO) and VSe2 nanohybrids. The highly conductive rGO wraps VSe2 to suppress the electrostatic stacking of nanosheets, and at the same time serves as a template to form a marigold-like nanohybrid structure. Moreover, the diffusion path of electrolyte ions is reduced and the strongly conductive graphene provides a 3D highway for electron transfer with improved reaction kinetics. The rGO- VSe2 nanohybrid was used as a cathode for ZIBs, which exhibited a good reversible potential of 221.5 mAh g−1 at 0.5 A g−1, and has excellent conversion efficiency with good cycling stability (~91.6% retention after 150 cycles). These empowering developments provide a better way to explore high-capacity, high-performance electrode materials.

Neodymium hydroxide nanorods [Nd(OH)3] are developed by a facile chemical precipitation method without any surfactants/templates at ambient temperature. The neodymium hydroxide nanorods–graphene [Nd(OH)3/G] nanohybrid is prepared by a simple solvothermal reduction process using Nd(OH)3/GO in a mass ratio of 1 : 0.5 in dimethylformamide for 7 h. This new Nd(OH)3/G nanohybrid can be used as an electrode material for supercapacitors; it exhibits good capacitive behaviour, with a specific capacitance of 820 F g−1 at 1 A g−1. The nanohybrid exhibits a capacitance retention of 96% even after 3000 continuous charge–discharge cycles. This excellent electrochemical behaviour is mainly attributed to the synergetic effect of Nd(OH)3 and graphene. The asymmetric supercapacitor (ASC) device is denoted as Nd(OH)3/G‖AC; a poly(vinylidene fluoride) electrospun membrane soaked in 6 M KOH was used as a separator as well as the electrolyte. The ASC device functions in an optimized potential window of 1.6 V with an energy density of 40 W h kg-1. Furthermore, the ASC device exhibits excellent capacitance retention of 85.3% with a Coulombic efficiency of 97% even after 5000 cycles. This new hybrid electrode material shows impressive performance and can be used as an electrode material for asymmetric supercapacitors.

Nickel selenide (NiSe) nanoparticles uniformly supported on graphene nanosheets (G) to form NiSe-G nanohybrids were prepared by an in situ hydrothermal process. The uniform distribution of NiSe on graphene bestowed the NiSe-G nanohybrid with faster charge transport and diffusion along with abundant accessible electrochemical active sites. The synergistic effect between NiSe nanoparticles and graphene nanosheets for supercapacitor applications was systematically investigated for the first time. The freestanding NiSe-G nanohybrid electrode exhibited better electrochemical performance with a high specific capacitance of 1280 F g-1 at a current density of 1 A g-1 and a capacitance retention of 98% after 2500 cycles relative to that of NiSe nanoparticles. Furthermore, an asymmetric supercapacitor device assembled using the NiSe-G nanohybrid as the positive electrode, activated carbon as the negative electrode and an electrospun PVdF membrane containing 6 M KOH as both the separator and the electrolyte delivered a high energy density of 50.1 W h kg-1 and a power density of 816 W kg-1 at an extended operating voltage of 1.6 V. Thus, the NiSe-G nanohybrid can be used as a potential electrode material for high-performance supercapacitors.

This work focuses on the influence of pulse reverse current parameters such as duty cycle and frequency on the microstructure and properties of graphene reinforced copper nanocomposite (Cu-Gr) coating. Graphene nanosheets were prepared by a liquid phase exfoliation technique and characterized using FE-SEM and Raman spectroscopy. Cu-Gr nanocomposite coating on stainless steel was prepared by pulse reverse electrodeposition method. The influence of pulse reverse current parameters such as duty cycle and frequency on the coating structure and texture was analyzed. By reducing the duty cycle and increasing frequency, a high amount of graphene co-deposition was achieved. A duty cycle of 40%, frequency of 1000 Hz and stirring speed of 500 rpm produced Cu-Gr coatings with maximum graphene codeposition. XRD analysis showed that the change in duty cycle and pulse frequency influenced the crystal structure, preferred orientation, and crystallite size of the deposit. A high pulse frequency improved the compactness of the composite coating, while longer pulse off-time and application of reverse pulse resulted in highly oriented (220) texture of pure Cu and Cu-Gr nanocomposite coatings. Due to graphene co-deposition, the copper grains became more refined, and hence the microhardness of the composite coating showed a tremendous increase compared to pure Cu coating. The Tafel polarization and electrochemical impedance studies revealed that pulse reverse electrodeposited Cu-Gr coating has higher corrosion resistance than pure Cu coating due to strong (220) texture and barrier effect of graphene.

Transition Metal Dichalcogenides In article number 2003709, Young Hee Lee, Young‐Kyu Han, Ki Kang Kim, and co‐workers demonstrate the unique basal plane activation of 2D MoS(2) via substituted V atom near chalcogen vacancy (VS(n) unit) in the lattice. The VS(n) units act as active sites and charge transfer pathways for efficient hydrogen evolution. This study adds insight into ways to engineer active sites in transition metal dichalcogenides electrocatalyst at the atomic level. [Image: see text]