Electroosmosis modulated peristaltic biorheological flow through an asymmetric microchannel: mathematical model

A theoretical study is presented of peristaltic hydrodynamics of an aqueous electrolytic non-Newtonian Jeffrey bio-rheological fluid through an asymmetric microchannel under an applied axial electric field. An analytical approach is adopted to obtain the closed form solution for velocity, volumetric flow, pressure difference and stream function. The analysis is also restricted under the low Reynolds number assumption (Stokes flow) and lubrication theory approximations (large wavelength). Small ionic Peclét number and Debye–Hückel linearization (i.e. wall zeta potential ≤ 25 mV) are also considered to simplify the Nernst–Planck and Poisson–Boltzmann equations. Streamline plots are also presented for the different electro-osmotic parameter, varying magnitudes of the electric field (both aiding and opposing cases) and for different values of the ratio of relaxation to retardation time parameter. Comparisons are also included between the Newtonian and general non-Newtonian Jeffrey fluid cases. The results presented here may be of fundamental interest towards designing lab-on-a-chip devices for flow mixing, cell manipulation, micro-scale pumps etc. Trapping is shown to be more sensitive to an electric field (aiding, opposing and neutral) rather than the electro-osmotic parameter and viscoelastic relaxation to retardation ratio parameter. The results may also help towards the design of organ-on-a-chip like devices for better drug design.     

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.     

Bound anionic states of DNA and RNA nucleobases: An EOM-CCSD investigation

In this article, we have studied the bound anionic states of DNA and RNA nucleobases using the newly developed bt-PNO-EOM-CCSD method and extended basis sets. All of the five nucleobases have a single bound anionic state, which is dipole bound in nature. The electron affinity corresponding to the dipole-bound state is found to be extremely sensitive to the used basis set, and a proper agreement with the available experimental data requires a large basis set with a sufficient number of diffuse functions. Electron correlation plays a major role in stabilizing the bound anionic states of nucleobases. No valence-bound anionic states are observed for any of the nucleobases.     

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...     

Intraspecific competition of predator for prey with variable rates in protected areas

Nonlinear Dynamics - In this present study, we systematically explore the periodicity (almost periodic nature) of a dynamical system in time-varying environment, which portrays a special case of...     

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...     

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.     

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...     

The development of platinum-rhodium alloy coatings on SS304 using a pulse/direct electrodeposition technique and their application to antibacterial activity

The current research focused on the development of Platinum–Rhodium alloy coating (Pt– Rh) on SS304 and its applications in antibacterial studies. Electrodeposition is considered to be one of the most suitable methods because it enhances the therapeutic effects of noble metals (Pt–Rh alloy). The electrodeposited coating is an economical and time-saving alternative to existing coating methods. The newly developed Pt–Rh coating was investigated using a scanning electron microscope (SEM) and an atomic force microscope (AFM). Using the agar Petri plate and broth culture method, the antibacterial effect of the platinum-rhodium alloy was investigated against Gram-negative Escherichia coli and Gram-positive bacteria such as Staphylococcus saprophytes, Bacillus Subtilis, and Enterococcus faecalis. The Pt–Rh alloy coated samples obtained by Direct current (DC) and Pulse coating (PC 50% and PC 75%) were examined for antibacterial study. The PC 75% Pt–Rh alloy coating exhibits significant antibacterial activity, demonstrating a maximum zone of inhibition while leaving the rest of the coated samples by DC and PC 50% duty cycles. The study also found that when the concentration of Pt–Rh solution rises from 5 μL to 15 μL, so does the antibacterial activity. The findings of the study showed that electrodeposited platinum-rhodium alloy metal ions may be handy bacteriostatic in the coming years.