Growth and characterization of two-dimensional crystals for communication and energy applications

This review article covers the growth and characterization of two-dimensional (2D) crystals of transition metal chalcogenides, h-BN, graphene, etc. The chemical vapor transport method for bulk single crystal growth is discussed in detail. Top-down methods like mechanical and liquid exfoliation and bottom-up methods like chemical vapor deposition and molecular beam epitaxy for mono/few-layer growth are described. The optimal characterization techniques such as optical, atomic force, scanning electron, and Raman spectroscopy for identification of mono/few-layer(s) of the 2D crystals are discussed. In addition, a survey was done for the application of 2D crystals for both creation and deterministic transfer of single-photon sources and photovoltaic systems. Finally, the application of plasmonic nanoantenna was proposed for enhanced solar-to-electrical energy conversion and faster/brighter quantum communication devices.     

On experiments in harmonically excited cantilever plates with 1:2 internal resonance

Nonlinear Dynamics - This work presents some experimental results for resonant nonlinear response of hyperelastic plates for 1:2 internal resonance. Previously developed topology optimization...     

Effect of polymer and ion concentration on mechanical and drug release behavior of gellan hydrogels using factorial design

Developing optimized hydrogel products requires an in-depth understanding of the mechanisms that drive hydrogel tunability. Here, we performed a full 4 × 4 factorial design study investigating the impact of gellan, a naturally derived polysaccharide (1%, 2%, 3%, or 4% w/v) and CaCl₂ concentration (1, 3, 7, or 10 mM) on the viscoelastic, swelling, and drug release behavior of gellan hydrogels containing a model drug, vancomycin. These concentrations were chosen to specifically provide insight into gellan hydrogel behavior for formulations utilizing polymer and salt concentrations expanding beyond those commonly reported by previous studies exploring gellan. With increasing gellan and CaCl₂ concentration, the hydrogel storage moduli (0.1–100 kPa) followed a power-law relationship and on average these hydrogels had higher liquid absorption capability and greater total drug release over 6 days. We suggest that the effects of gellan and CaCl₂ concentration and their interactions on hydrogel properties can be explained by various phenomena that lead to increased swelling and increased resistance to network expansion.     

Uranium: occurrence,distribution across India and its potential health effects

Journal of Radioanalytical and Nuclear Chemistry - Uranium contamination in the aquatic environment is an emerging concern worldwide. With the development of the global economy, uranium...     

Recent advances in application of the graphene-based membrane for water purification

Graphene is an atomic layer thick carbon-based material with unique two-dimensional architecture and extraordinary physiochemical, optical, electrical, and mechanical properties. Graphene and its derivatives show significant promises for the development of nanoporous ultrathin filtration membranes capable of molecular separation properties. Graphene-based nanofiltration membranes featuring distinct laminar structures can offer various novel mass-transport phenomena for purifying water, energy storage and separation, gas separation, and proton conductors. The latest developments in water purification techniques through graphene-based membranes including engineering, design, and fabrication of diverse graphene, graphene-oxide, and graphene-composite membranes are provided here in relation to their application paradigm for purifying water. The critical views on pollutant removal mechanisms for water purification along with optimization measures are specially highlighted. In addition, the challenges, shortcomings, and future prospects are pointed out. The green and large-scale synthesis technology of graphene coupling with advanced membrane fabrication techniques can promote these state-of-the-art nanofiltration membranes for a wide range of applications.     

Characterization of the 46.9-nm soft X-ray laser beam from a capillary discharge

Intense lasing had been obtained from argon plasma in the soft X-ray region from a capillary discharge plasma system. Different diagnostics have been used to characterize the lasing properties by recording the temporal, spatial, and spectral profiles of the emission. The divergence measurement indicates that the soft X-ray laser beam has good directionality with a divergence of 3.5 mrad. The spectrum of the laser beam measured using a transmission grating showed intense lasing line at 46.9 nm. Diffraction orders as high as 10th orders were observed. The temporal profile recorded with a vacuum diode showed a distinct laser peak with a pulse width ~1.2 ns (FWHM). In addition, the coherence of the X-ray laser beam was also confirmed from the high-contrast interference fringes (visibility ~85 %) recorded using double slits.     

Investigations of thermal,optical and electrical properties of Se85In15−xBix glasses and thin films

Journal of Thermal Analysis and Calorimetry - In our present research work, we have investigated the different thermal, optical and electrical properties of Se85In15?xBix alloys in bulk and...     

Electrothermal analysis in two-layered couple stress fluid flow in an asymmetric microchannel via peristaltic pumping

Journal of Thermal Analysis and Calorimetry - Being motivated from the recent developments in biomicrofluidics, a mathematical model is presented to analyze the two-layered electrothermal flow via...     

Synthesis of nanoplate bismuth oxychloride—a visible light active material

We have synthesized bismuth oxychloride (BiOCl) by wet chemical route. Characterization of the synthesized samples has been carried out using XRD, SEM with EDAX, HRTEM, FT-IR, Raman Spectroscopy, PL and UV. XRD and SEM analysis confirms crystallite size varying from 20–40 nm. FTIR spectrum indicates that the prepared material is highly pure and there is no water molecule present. Raman and photoluminescence spectrum of the bismuth oxychloridenanoplate demonstrated strong blue light emission which brings them in a special class of materials which work under visible light exposure. UV-Vis spectroscopy shows very less charge carriers transit time under visible light thus confirming excellent photocatalytic properties of material.