Tent-Shaped Surface Morphologies of Silicon: Texturization by Metal Induced Etching

Silicon - Nano-metal/semiconductor junction dependent porosification of silicon has been studied here. The silicon nanostructures (SiNSs) have been textured on n- and p- type silicon wafers using...     

Making Nonwoven Fibrous Poly(ε‐caprolactone) Constructs for Antimicrobial and Tissue Engineering Applications by Pressurized Melt Gyration

A pressurized melt gyration process has been used for the first time to generate poly(ε‐caprolactone) (PCL) fibers. Gyration speed, working pressure, and melt temperature are varied and these parameters influence the fiber diameter and the temperature enabled changing the surface morphology of the fibers. Two types of nonwoven PCL fiber constructs are prepared. First, Ag‐doped PCL is studied for antibacterial activity using Gram‐negative Escherichia coli and Pseudomonas aeruginosa microorganisms. The melt temperature used to make these constructs significantly influences antibacterial activity. Neat PCL nonwoven scaffolds are also prepared and their potential for application in muscular tissue engineering is studied with myoblast cells. Results show significant cell attachment, growth, and proliferation of cells on the scaffolds.

     

Novel organic–inorganic composite material as a cation exchanger from a triterpenoidal system of dammar gum: synthesis,characterization and application

A pioneer study has been conducted to synthesize novel hydrogel starting from a non-cellulosic raw material, gum dammar-a triterpenoidal system, and then converting this hydrogel into an organic–inorganic composite zirconium-based ion exchanger. Gum dammar was cross-linked with polyacrylamide zirconium (IV) iodo-oxalate [Gd-cl-poly(AAm)-Zr (IV) iodo-oxalate] by incorporating inorganic precipitates into the polymeric mixture. The polymeric mixture was synthesized using gum dammar (Gd), acrylamide (AAm), N, N′-methylene-bis-acrylamide (MBA) and potassium persulphate (KPS). The reaction conditions for synthesis of hydrogel and ion exchanger such as time (120 min), temperature (70 °C), solvent (4 mL), concentration of monomer (12.97 × 10^?3 mol/L), initiator (1.48 × 10^?4 mol/L), cross-linker (4.22 × 10^?4 mol/L) and ratio of zirconium oxychloride (0.1 M), potassium iodate (0.1 M) and oxalic acid (0.1 M) in ratio 2:3:2 were optimized to obtain maximum ion exchange capacity (2.02 meq/g). The morphology and structure of hydrogel and ion exchanger were studied using FTIR, SEM, XRD and TGA/DTA/DTG. The SEM study was followed by energy dispersive spectroscopy for elemental analysis. The ion exchanger was quite stable in various acids and bases at low concentration but it completely dissolved in acids and bases at high concentrations. Distribution studies showed that the synthesized ion exchanger had high selectivity for Pb²⁺ ions. Thus, the polymeric-inorganic hybrid material showed integration of both inorganic and organic characteristics within the composite material.     

Studies on Micellar Behavior of PEO‐PBO or PEO‐PBO‐PEO Copolymers,or Surface Active Amphiphilic Ionic Liquids in Aqueous Media and Exploration of the Micellar Solutions for Solubilization of Dexamethasone and its Delayed Release

The aggregation behavior of a di‐ and tri‐block copolymers of type PEO‐PBO, PEO‐PBO‐PEO, surface‐active ionic liquid (SAIL) of type 4‐dodecyl‐4‐methylmorpholinium chloride [C₁₂mmor][Cl], and 1‐dodecyl‐1‐methylpyrrolidinium chloride [C₁₂mpyrr][Cl]) in water as well as in 10 mM of a poorly water soluble dexamethasone (dex) aqueous solution was studied by determining the critical micelle concentrations using drug solubilization, surface tension, and isothermal titration calorimetry (ITC) methods. ITC measurements were also made on solutions prepared by mixing the micellar aqueous solutions of copolymers and simple aqueous solutions of SAIL across the mole fractions at three different temperatures (298.15, 308.15, and 318.15 K). The thermodynamic parameters, namely Gibbs free energy (ΔG_m), enthalpy (ΔH_m), and entropy (ΔS_m), of micellization were calculated, and it was observed that the negative ΔG_m and positive ΔS_m for the mixture solutions increase with the increase in mole fraction of SAIL. Otherwise, the micellization is reported to be a spontaneous and highly entropy‐driven process. The dex‐solubilized micellar solutions were mixed with agar to obtain standing gels. The gel samples were dry‐cast into thin films, and the release of dex from films by simple dilution was monitored by UV measurements. The drug release data was fitted to several mechanistic models, and it was inferred that the release mechanism for dex from thin films is non‐Fickian for mixtures and Fickian in copolymer or SAIL micellar aqueous solutions. The transport of dex is diffusion‐controlled with diffusivities of 5.8–12 × 10^?11 m² s^?1 for copolymer micelles, 5–11 × 10^?11 m² s^?1 for micelles of SAIL, and 3–14 × 10^?11 m² s^?1 for the mixed micelles of copolymer and SAIL in aqueous media.     

A novel hybrid deep learning method with cuckoo search algorithm for classification of arrhythmia disease using ECG signals

Neural Computing and Applications - This work presents an efficient hybridized approach for the classification of electrocardiogram (ECG) samples into crucial arrhythmia classes to detect heartbeat...     

A numerical study on nonlinear DPL model for analyzing heat transfer in tissue during thermal therapy

In the present paper, therapeutic treatment of infected tumorous cells has been studied through mathematical modeling and simulation of heat transfer in tissues by using a nonlinear dual-phase lag bioheat transfer model with Dirichlet boundary condition. The components of volumetric heat source in this model such as blood perfusion and metabolism are assumed experimentally validated temperature-dependent function, which gives more accurate temperature distribution in tissues through this model. We have used the finite difference and RK (4, 5) techniques of numerical methods to solve the proposed problem and obtained the exact solution in a particular case. After comparison, we got a good agreement between them. We have used dimensionless quantities throughout this paper. The effect of relaxation and thermalization time with respect to dimensionless temperature distribution has been analyzed in the treatment process.     

NMR inspired energy efficient protocol for heterogeneous wireless sensor network

Wireless Networks - This paper presents a naked mole rat (NMR) inspired energy efficient protocol for heterogeneous wireless sensor network. NMR uses strategic deployment among three types of nodes...