Comparison of geometry dependent resistance models with conventional models for estimation of effective thermal conductivity of two-phase materials

The geometry dependent resistance models are used to estimate the effective thermal conductivity of two-phase materials based on the unit cell approach. The algebraic equations are derived based on isotherm approach for various geometries. The effective thermal conductivity of the above models are found and compared with experimental data with a minimum and maximum deviation of ±3.976 and ±19.55%, respectively. The present models are good agreement with experimental results.     

Induction of B1 phase in binary mixtures of rod- and bent-shaped mesomorphic compounds

The miscibility of a rod-shaped (R) and a bent-shaped (BC) compound forming an induced B₁ phase is reported. B₁ phase is not present in both R and BC in the entire phase sequence. R exhibits partially bilayered smectic A_d phase with cholesteric and TGB while BC shows a B₂ phase. It is interesting to show that the B₂ phase is totally diminished in low composition (weight%) of BC, B₁ phase is induced at lower temperature range (~90-135 °C). A dielectric study is also incorporated to confirm the induction of B₁ phase in the binary mixture.     

Performance analysis of coherent optical scatterometry

Scatterometry is a well established technique currently utilized in research, as well as in industrial applications, to retrieve the properties of a given scatterer (the target) by looking at how the light coming from a certain source is diffracted in the far field. Currently the light source is often a discharge lamp that, after wavelength filtering, can be thought as a quasi-monochromatic, but spatially incoherent, source. In the present work, benefits of using a focused spot from a spatially coherent light source, as that emitted by a laser, are investigated on a theoretical viewpoint. The focused spot is scanned over the object of interest and, for each scan position, a far-field diffraction pattern is recorded. Our results show that spatially coherent light can sensibly increase the accuracy of the technique with respect to the target’s geometrical profile.     

Sensitivity enhancement and matrix effect evaluation during summation of multiple transition pairs—case studies of clopidogrel and ramiprilat

Sensitivity enhancement via summation of multiple MRM transition pairs is gaining popularity in tandem mass spectrometric assays. Numerous validation experiments describing the assays for two model substrates, clopidogrel and ramiprilat, were performed. The quantitation of clopidogrel was achieved by the summation of transition pairs m/z 322.2 to m/z 212.0 and m/z 322.2 to m/z 184.0, while that of ramiprilat was achieved by the summation of transition pairs m/z 389.2 to m/z 206.1 and m/z 389.2 to m/z156.1. The use of summation approach achieved sensitivities of >2 fold for both compounds as compared with the reported single MRM transition pair assays. The validation experiments addressed some important assay development issues, such as: (a) lack of impact of matrix effect; (b) unequivocal verification of the percentage contribution of each MRM transition pair towards sensitivity; (c) sensitivity enhancement factor achieved by summation approach of MRM transition pairs; and (d) accurate prediction of quality control samples using summation approach vs a single MRM transition pair. In summary, the appropriateness of using two MRM transition pairs for quantitation was demonstrated for both clopidogrel and ramiprilat. Additionally, pharmacokinetic application of the MRM transition pair assays using a summation approach was established for the two compounds. Copyright © 2009 John Wiley & Sons, Ltd.     

Flexible conducting polymer transistors with supercapacitor function

Planar organic electrochemical transistors (OECTs) using PEDOT:PSS as the channel material and nanostructured carbon (nsC) as the gate electrode material and poly(sodium 4‐styrenesulfonate (PSSNa) gel as the electrolyte were fabricated on flexible polyethylene terephthalate (Mylar^®) substrates. The nsC was deposited at room‐temperature by supersonic cluster beam deposition (SCBD). Interestingly, the OECT acts as a hybrid supercapacitor (to give a device that we indicate as transcap). The energy storage ability of transcaps has been studied with two cell configurations: one featuring PEDOT:PSS as the positive electrode and nsC as the negative electrode and another configuration with reversed electrode polarity. Potentiostatic charge/discharge studies show that both supercapacitors show good performance in terms of voltage retention, in particular, when PEDOT:PSS is used as the positive electrode. Galvanostatic charge–discharge characteristics show typical symmetric triangular shape, indicating a nearly ideal capacitive behavior with a high columbic efficiency (close to 100%). © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 96–103     

Development of Humidity Sensor Using Nanoporous Polycarbonate Membranes

Russian Journal of Physical Chemistry A - In the present work, the effect of temperature and moisture has been studied on nano-porous polycarbonate membranes of size 15, 50, and 80 nm, respectively...     

High-performance thin-layer chromatographic method for the determination of chlorpyrifos and its metabolite in visceral samples

JPC – Journal of Planar Chromatography – Modern TLC - In an attempt to determine chlorpyrifos insecticide and its metabolite 3,5,6-trichloropyridinol in visceral samples, a rapid...