1,4‐Methano‐11a‐methyl‐4,4a,11,11a‐tetrahydro‐1H‐benzo­[b]­fluoren‐11‐one

The title compound, C₁₉H₁₆O, crystallizes with two mol­ecules of opposite chirality in the asymmetric unit. In both mol­ecules, the naphthalene and cyclo­pentanone moieties are individually planar. The two cyclo­pentane rings adopt envelope conformations, while the cyclo­hexane ring adopts a boat conformation.     

Unambiguous evidence for wurtzite phase in capped CdS quantum dots

The problem of identification of the correct crystalline structure of CdS nanoclusters below 2.5 nm in size is outlined. Structure of thiophenol capped CdS nanoclusters in the size range 1.2–4.3 nm, synthesized using cadmium acetate solution in methanol, is discussed using powder XRD and electron diffraction data. Unambiguous confirmation of the wurtzite phase in CdS nanoclusters below 2.5 nm size is reported. The observation of 102 wurtzite peak in the XRD patterns of such nanoclusters indicates low stacking fault concentration.     

MOS capacitor loaded frequency agile microstrip antenna

A new MOS capacitor loaded frequency agile microstrip patch antenna is proposed in which the operating frequency of the rectangular microstrip antenna is electronically controlled by the bias voltage of the MOS capacitor. Theoretical investigations, based on a modal expansion cavity model as well as an improved theory of Richards et al. (1981, IEEE Transactions on Antennas and Propagation, 29, 38-41), are carried out for five different oxide (Si₃N₄) thicknesses from 100 Å to 500 Å for the (Au-Si₃N₄-Si) MOS structure. The maximum obtainable frequency tuning range (76.08%) is achieved for the lowest value of oxide thickness (100 Å); this is almost 1.5 times the value reported for the varactor loaded patch antenna. The larger frequency variation is achieved with lower variation in the bias voltage as compared with the varactor.     

Electrochemical and Spectroscopic Studies on the Interaction of Gatifloxacin,Moxifloxacin and Sparfloxacin with DNA and Their Analytical Applications

The electrochemical oxidation of the three fluoroquinolone drugs FQs: gatifloxacin GTF, moxifloxacin MXF and sparfloxacin SPF, at the bare and DNA‐modified glassy carbon electrodes has been studied by voltammetric techniques. The three FQs showed one irreversible oxidation peak at potential range 0.85–0.91 V vs. Ag‐AgCl, in phosphate buffer of pH 7.0. Differential pulse voltammetry (DPV) and UV‐absorption spectroscopic techniques were employed to probe the interaction between the FQs and calf thymus double stranded deoxyribonucleic acid (ds CT‐DNA). From electrochemical data, the binding constant between DNA and the gatifloxacin, moxifloxacin and sparfloxacin are calculated to be 3228, 2596 and 2857 M^?1 respectively. Based on electrochemical and spectroscopic results, the mode of binding of fluoroquinolone to DNA through combined effect of intercalation and electrostatic interaction was concluded. A detection scheme based on a preconcentration and differential pulse voltammetric (DPV) determination at dsDNA modified glassy carbon electrode (DNA/GCE) was proposed for the trace determination of the studied analytes. The developed method was successfully applied to the determination of the FQs in pharmaceutical formulations.     

Experimental investigation for enhanced ferrofluid heat transfer under magnetic field effect

This paper reports an experimental work on the convective heat transfer of ferrofluid flowing through a heated copper tube in the laminar regime in the presence of magnetic field. Significant enhancement on the heat transfer of ferrofluid by applying various orders of magnetic field is observed in this experiment. Also in this experiment, the effect of magnetic nanoparticles concentrations and magnet position have been investigated. The main reason for the enhancement of heat transfer coefficient could be caused due to remarkable changes in thermophysical properties of ferrofluid under the influence of applied magnetic field.     

Lubricant properties of Moringa oil using thermal and tribological techniques

The increasing application of biobased lubricants could significantly reduce environmental pollution and contribute to the replacement of petroleum base oils. Vegetable oils are recognized as rapidly biodegradable and are thus promising candidates for use as base fluids in formulation of environment friendly lubricants. Although many vegetable oils have excellent lubricity, they often have poor oxidation and low temperature stability. Here in, we report the lubricant potential of Moringa oil, which has 74% oleic acid content and thus possess improved oxidation stability over many other natural oils. For comparison, Jatropha oil, cottonseed oil, canola oil and sunflower oil were also studied. Among these oils, Moringa oil exhibits the highest thermo-oxidative stability measured using PDSC and TG. Canola oil demonstrated superior low temperature stability as measured using cryogenic DSC, pour point and cloud point measurements. The friction and wear properties were measured using HFRR. Overall, it was concluded that Moringa oil has potential in formulation of industrial fluids for high temperature applications. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.     

Soliton solutions of Burgers equations and perturbed Burgers equation

This paper carries out the integration of Burgers equation by the aid of tanh method. This leads to the complex solutions for the Burgers equation, KdV-Burgers equation, coupled Burgers equation and the generalized time-delayed Burgers equation. Finally, the perturbed Burgers equation in (1+1) dimensions is integrated by the ansatz method.     

Modified simple equation method for nonlinear evolution equations

This paper reflects the implementation of a reliable technique which is called modified simple equation method (MSEM) for solving evolution equations. The proposed algorithm has been successfully tested on two very important evolution equations namely Fitzhugh-Nagumo equation and Sharma-Tasso-Olver equation. Numerical results are very encouraging.