On the Laplace-transformed-based local meshless method for fractional-order diffusion equation

In this work, we formulate a local meshless method based on Laplace transform to estimate the solution of a time-fractional diffusion equation. The collocation is constructed over small subdomains and combined with Laplace transform for a temporal variable. In this approach, the differentiation matrices are constructed by solving small systems over small local domains instead of a large global collocation matrix. The application of Laplace transform avoids the classical time-stepping procedure. This method is capable of solving fractional differential equations in multidimensions with higher accuracy.     

Numerical solution of Klein–Gordon and sine-Gordon equations by meshless method of lines

We investigate numerical solution of the one dimensional nonlinear Klein–Gordon and two-dimensional sine-Gordon equations by meshless method of lines using radial basis functions. Results are compared with some earlier work showing the efficiency of the applied method. Salient feature of this method is that it does not require a mesh in the problem domain. Multiquadric and Gaussian are used as radial basis functions, which use a shape parameter. Choice of the shape parameter is still an open problem. We explore optimal value of the shape parameter without applying any extra treatment. For multiquadric, eigenvalue stability is studied without enforcing the boundary conditions whereas for Gaussian, the boundary conditions are enforced.     

Molecular dynamics simulations of the interactions and dispersion of carbon nanotubes in polyethylene oxide/water systems

Molecular dynamics simulations were carried out to investigate carbon nanotube (CNT) interactions and dispersion in a polyethylene oxide (PEO)/water solution. The potential of mean forces (PMF) which embodies the entropic and enthalpic contributions by the solvent and the polymer molecules were computed. The relative enthalpic and entropic contributions to the PMF were studied in order to understand the CNT interaction mechanisms in solution. An adaptive biasing force (ABF) method was used to speed up the PMF calculations. The simulation results provide detailed atomic arrangements and atomic interactions between the CNTs and surrounding molecules (PEO and water). This molecular level computational study provides insights into the CNT’s interactions with PEO polymer/water systems.     

Evaluation of Antioxidant Properties and Mineral Composition of Purslane (Portulaca oleracea L.) at Different Growth Stages

The main objective of this research was to appraise the changes in mineral content and antioxidant attributes of Portulaca oleracea over different growth stages. The antioxidant activity was measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric-reducing antioxidant power (FRAP) assays. The iodine titration method was used to determine the ascorbic acid content (AAC). DPPH scavenging (IC(50)) capacity ranged from 1.30 ± 0.04 to 1.71 ± 0.04 mg/mL, while the ascorbic acid equivalent antioxidant activity (AEAC) values were 229.5 ± 7.9 to 319.3 ± 8.7 mg AA/100 g, total phenol content (TPC) varied from 174.5 ± 8.5 to 348.5 ± 7.9 mg GAE/100 g. AAC 60.5 ± 2.1 to 86.5 ± 3.9 mg/100 g and FRAP 1.8 ± 0.1 to 4.3 ± 0.1 mg GAE/g. There was good correlation between the results of TPC and AEAC, and between IC(50) and FRAP assays (r(2) > 0.9). The concentrations of Ca, Mg, K, Fe and Zn increased with plant maturity. Calcium (Ca) was negatively correlated with sodium (Na) and chloride (Cl), but positively correlated with magnesium (Mg), potassium (K), iron (Fe) and zinc (Zn). Portulaca olerecea cultivars could be used as a source of minerals and antioxidants, especially for functional food and nutraceutical applications.     

MHD boundary layer bionanoconvective non‐Newtonian flow past a needle with Stefan blowing

The purpose of the article is to present a transport model for magnetohydrodynamics‐forced convective non‐Newtonian boundary flow from a thin needle in a nanofluid in the presence of microorganisms and Stefan blowing. The governing equations are reduced to ordinary differential equations with the help of similarity transformations and then numerically solved by using the Matlab bvp4c function. The effect of various emerging parameters on the flow field, heat, mass, and density of motile microorganisms transfer was computed and studied. It was found that some of the parameters have an important effect on the boundary layer thickness. Justification with earlier simpler model in the absence of magnetic field is included. The model finds applications in various transdermal delivery system, biomedical electromagnetic treatments and to design new medical devices for cell delivery to the central nervous system.     

Interfacial interaction and mechanical properties of chitin whisker–poly(vinyl alcohol) gel‐spun nanocomposite fibers

Nanocomposite fibers were prepared from chitin whiskers (ChWs) as the reinforcing phase and poly(vinyl alcohol) (PVA) as the matrix. Colloidal suspensions of ChWs, obtained by acid hydrolysis of chitin from crab shell, were thoroughly mixed with aqueous PVA. The homogeneous PVA–ChW suspensions were gel‐spun into a methanol coagulating bath. Wide‐angle X‐ray diffraction patterns evidenced the orientation of ChWs along the fiber axis. From differential scanning calorimetry, the crystallinity of the PVA component was found to increase with ChW loading due to the possible dragging of PVA chains adhering to ChWs during vertical extrusion. The non‐isothermal crystallization peak of PVA was observed to shift to lower temperature with ChW loading indicating interfacial interactions between PVA and ChW. Further interaction between PVA and ChW was evidenced by the shifting of the Fourier transform infrared bands of PVA to lower wavenumber and the dynamic tan δ peak, corresponding to α‐relaxation of PVA, shifting to higher temperature. The interaction of ChWs with the matrix PVA yielded a significant enhancement in the mechanical properties of the nanocomposites. Copyright © 2012 Society of Chemical Industry     

A Novel Approach to Utilize DSM ＆ Smart Grid Initiatives for Power System Operations

This paper presents in detail the idea to utilize the advent of smart grid technologies and DSM （demand side management）, to ease the operational requirements of power system operations. Utilization of DSM and smart grids, to control load rather than generations, is explored. Usually, system security is attained through preventive measures, the system is maintained and prepared in advance to survive credible outages through ＂reserve management＂, for which requirements are specified as security standards in grid codes. However, with the utilization of DSM techniques on transmission level such as ＂direct control load＂, ＂responsive load＂, and interruptible load control, system operations can be shifted towards ＂corrective＂ mode keeping intact the system security.