Methods for the numerical solution of the Benjamin‐Bona‐Mahony‐Burgers equation

L^∞‐error estimates for finite element for Galerkin solutions for the Benjamin‐Bona‐Mahony‐Burgers (BBMB) equation are considered. A priori bound and the semidiscrete Galerkin scheme are studied using appropriate projections. For fully discrete Galerkin schemes, we consider the backward Euler method and analyze the corresponding error estimates. For a second order accuracy in time, we propose a three‐level backward method. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008     

Copper‐Catalyzed Arylation of Nitrogen Heterocycles from Anilines under Ligand‐Free Conditions

The arylation of pyrazole and derivatives can be achieved by coupling arenediazonium species (formed in situ from anilines) by using a catalytic system that employs low‐toxicity and inexpensive copper metal under very mild and ligand‐free conditions (T=20 °C). From other nitrogen heterocycles, the presence of an additive (NBu₄I) significantly improves the efficiency of the catalytic system. These results represent the first examples of C?N bond formation from arenediazonium species.     

Forced convection heat transfer of nanofluids from a horizontal plate with convective boundary condition and a line heat source embedded in porous media

Journal of Thermal Analysis and Calorimetry - In this study, forced convective flow of nanofluids over a horizontal flat plate with convective boundary condition and a heated line source which are...     

Effect of Type of Fragrance Compounds on Their Location in Hexagonal Liquid Crystal

Three fragrances, limonene, benzaldehyde, and phenethylalcohol (that differ in their polarities), were solubilized in hexagonal liquid crystal using the polyethylene oxide‐polypropylene oxide‐polyethylene oxide, (EO₂₇ PO₆₁ EO₂₇), P₁₀₄ triblock copolymer, and water. The interlayer spacing of the hexagonal liquid crystals were established using small‐angle x‐ray scattering (SAXS). The SAXS data are used to calculate the interfacial area per polyethylene oxide (PEO) block and the radius of the apolar domain in order to determine the location of each fragrance in the association structure. The results show the presence of limonene inside the core of the apolar domain while benzaldehyde is only partially located inside the core with the other part contributing to the interface. The third fragrance, phenethylalcohol, is present between the polar heads, thus, contributing entirely to the interface.     

Single-walled carbon nanotubes chemiresistor aptasensors for small molecules: picomolar level detection of adenosine triphosphate

Here we report single walled-carbon nanotubes (SWNTs)-based chemiresistor aptasensors for highly sensitive and selective detection of weakly or uncharged molecules using the displacement format. As a proof-of-concept we demonstrate the detection of ATP, a small weakly charged molecule, by displacement of the ssDNA anti-ATP aptamer hybridized to a small capture oligonucleotide covalently attached on SWNTs, with picomolar sensitivity and selectivity over GTP.     

Performance Analysis of a New Water-based Microcooling System

In the electronic industry, dissipating the heat load becomes a critical factor for highly developed designs. These require higher power transfer in a more compact size. In the current study, a new microcooling system was developed and tested. It utilizes the enhancement in heat transfer characteristics associated with implementing a vortex promoter in the evaporator segment of a water-based heat pipe. The test evaporator was a cavity of 4-mm diameter and 23-mm length in an electrically heated aluminum block. A helical coil (of various diameters, namely 500, 300, and 250 μm) was introduced to the evaporator segment to act as a vortex promoter. Configurations of a new microcooling system based on a modified heat pipe technology were built and tested. The presented system proves to work efficiently in situations where a closed-loop thermosyphon encounters film boiling limitation. The most efficient configuration has a flow modifier diameter about one-tenth of the evaporator chamber gap, while the diameter of the return line was three-quarters of the evaporator gap. This configuration shows a stable operation characteristic and possesses high thermal efficiency. The maximum heat flux obtained by such a configuration was 305 W/cm² when it runs at 103°C saturated temperature and 0.01°C/W thermal resistance. A uniform temperature distribution along the system was noticed.     

Peristaltic activity in blood flow of Casson nanoliquid with irreversibility aspects in vertical non-uniform channel

Due to the illuminating function of nanoliquids in several technological and medicinal domains, particularly in liquid transport processes known as peristalsis, inquisitive researchers have investigated the flow of peristaltic nanofluids. Consequently, the current study investigates the entropy production and magnetic influence on the peristaltic transport of heat and mass transport of Casson nanofluid in a non-uniform channel under convective circumstances. Utilizing the perturbation approach, fields of concentration, temperature, and velocity are derived from non-linear coupled partial differential equations (PDE). Entropy generation studies have been done. In addition, the influence of associated factors via specific physical terms, including the Sherwood number, the skin-friction coefficient, and the Nusselt number, for both Casson and Newtonian liquids, as well as the trapping phenomena, is visually examined.