Blending poly(methyl methacrylate) and poly(styrene‐co‐acrylonitrile) as composite polymer electrolyte

A blend of poly(methyl methacrylate) (PMMA) and poly(styrene‐co‐acrylonitrile) (PSAN) has been evaluated as a composite polymer electrolyte by means of differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, ac impedance measurements, and linear sweep voltammetry (LSV). The blends show an interaction with the Li⁺ ions when complexed with lithium perchlorate (LiClO₄), which results in an increase in the glass‐transition temperature (T_g) of the blends. The purpose of using PSAN as another component of the blend is to improve the poor mechanical properties of PMMA‐based plasticized electrolytes. The mechanical property is further improved by introducing fumed silica as inert filler, and hence the liquid electrolyte uptake and ionic conductivity of the composite systems are increased. Room‐temperature conductivity of the order of 10^?4 S/cm has been achieved for one of the composite electrolytes made from a 1/1 blend of PSAN and PMMA containing 120% liquid electrolyte [1M LiClO₄/propylene carbonate (PC)] and 10% fumed silica. These systems also showed good compatibility with Li electrodes and sufficient electrochemical stability for safe operation in Li batteries. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1319–1328, 2001     

Determination of magnetic field constant of DC permanent magnet motor powered by photovoltaic for maximum mechanical energy output

The DC permanent magnet motor coupled with centrifugal pump has the better matching when directly powered by photovoltaic (PV) array. The important parameter of DC permanent magnet (DC PM) motor is magnetic field constant. The method for the determination of optimum magnetic field constant of DC PM motor, when powered by PV, has been obtained, and its analysis has been carried out for different magnetic field constants. It has been found that the maximum output is available at the output-energy-weighted average value of magnetic field constant. The parameter, magnetic field constant, should be properly selected during the design of DC PM motor in order to extract the maximum power from PV array.     

Effect of Flank Wear on the Topography of Machined Surfaces

The effect of flank wear on the topography of machined surfaces is investigated by studying its effect on the shape of the tool nose. For this purpose, turning experiments were performed to produce surfaces corresponding to different levels of flank wear. The distribution of flank wear at the tool nose during these experiments caused the nose radius to decrease, which when replicated on the machined surface resulted in narrower and deeper feedmarks. This change in the geometry of feedmarks was represented by the increase in the arithmetic average roughness of the surface profile heights.     

Growth of LiNaSO4 single crystals from a solution of stoichiometric pH value

Single crystals of LiNaSO₄ were grown without adjusting the pH value of equimolar aqueous solution containing Li₂SO₄·H₂O and NaHSO₄ at 30°C. As-grown crystals were characterized using X-ray, IR, Raman and other crystal perfection studies such as chemical etching, scanning electron micrograph and microhardness measurements. Atomic absorption technique was adopted to verify the composition of Li⁺ and Na⁺ ion content and these were found to be consistent with the desired composition to within ± 6 mol%.     

Antioxidant properties,anti-inflammatory effects,and bioactive constituents of the Indian medicinal rice Njavara yellow compared with staple varieties

Polar and non-polar extracts of Njavara yellow rice (NYr) and bran (NYb) were investigated for antioxidant activity, chemical indices, anti-inflammatory effects, and bioactive compounds, of which the results were compared between the 2 staple varieties Uma and Jaya. Methanol extracts of NYb showed significantly (p<0.05) higher antioxidant activity than other varieties with the IC₅₀ values of 97 μg/mL (DPPH^·) and 48 μg/mL (ABTS^·+). NYb showed a higher anti-inflammatory effect and higher chemical indices (6.36 mg, phenolic content; 1.44 mg, flavonoid content; 3.06 mg, proanthocyanidin content; and 15.5 mg, phytate content per gram of dry weight of bran) than NYr and staple varieties. The content of bioactive compounds, oryzanols (659 μg/mL) and tricin (24.58 mg/100 g bran), were higher in NYb than in other varieties. Evaluation of biological activities and quantification of bioactive compounds of Njavara yellow are first pursued herein to corroborate Njavara Ayurveda medicinal use.