Validated Stability Indicating RP-HPLC Method for Simultaneous Estimation of Ofloxacin and Cefixime in their Combined Dosage Form

The objective of the current study was to develop and validate a simple, accurate, precise and selective stability-indicating gradient reverse phase high performance liquid chromatographic method for simultaneous estimation of Ofloxacin and Cefixime in pharmaceutical formulation in presence of degradation products. The chromatographic separation of Ofloxacin and Cefixime was achieved on Shimadzu LC-20AT series HPLC having C18-ODS bonded column (250 x 4.6 mm, 40 °C, 10 µL) using UV/Visible detector at 276 nm. The optimized mobile phase was consisted of a methanol: phosphate buffer (50:50) at a flow rate of 1.0 ml/m. The retention times were 4.799 and 1.602 m for Ofloxacin and Cefixime respectively. The proposed method provided linear responses within the concentration ranges 5-25 µg/ml for Ofloxacin and Cefixime both. The limit of detection (LOD) and limit of quantification (LOQ) values were found to be 0.0259, 0.078 µg/ml and 0.0206, 0.062 µg/ml for Ofloxacin and Cefixime F respectively. The developed method was validated as per ICH guidelines with respect to specificity, linearity, accuracy, precision, robustness and ruggedness. The studies data revealed that developed method was convenient, fairly reliable, sensitive, less expensive and reproducible

Activation gaps for the fractional quantum Hall effect: realistic treatment of transverse thickness

The activation gaps for fractional quantum Hall states at filling fractions $\nu=n/(2n+1)$ are computed for heterojunction, square quantum well, as well as parabolic quantum well geometries, using an interaction potential calculated from a self-consistent electronic structure calculation in the local density approximation. The finite thickness is estimated to make $\sim$30% correction to the gap in the heterojunction geometry for typical parameters, which accounts for roughly half of the discrepancy between the experiment and theoretical gaps computed for a pure two dimensional system. Certain model interactions are also considered. It is found that the activation energies behave qualitatively differently depending on whether the interaction is of longer or shorter range than the Coulomb interaction; there are indications that fractional Hall states close to the Fermi sea are destabilized for the latter.Comment: 32 pages, 13 figure

The Composite Fermion Hierarchy: Condensed States of Composite Fermion Excitations?

A composite Fermion hierarchy theory is constructed in a way related to the original Haldane picture by applying the composite Fermion (CF) transformation to quasiparticles of Jain states. It is shown that the Jain theory coincides with the Haldane hierarchy theory for principal CF fillings. Within the Fermi liquid approach for few electron systems on the sphere a simple interpretation of many-quasiparticle spectra is given and provides an explanation of failure of CF hierarchy picture when applied to the hierarchical $4/11$ state.Comment: 6 pages, Revtex, 4 figures in PostScript, submitted to Phys. Rev. Let

Insight into microstructure and flexural strength of ultra-high temperature ceramics enriched SICARBON™ composite

Research efforts on Ceramic Matrix Composites (CMCs) are aimed to increase the operating temperature in oxidizing environments by adding Ultra-High Temperature Ceramic (UHTC) phases to the matrix. The structural performances of UHTC-enriched CMCs are generally investigated through bending test because it requires simple fixture and specimen geometry with small quantity of plate material. However, there are hardly any scientific studies which bring out what bending test conditions are required to determine reliable flexural strength of these composites. In this study, the effect of span length and specimen orientation on the flexural strength of UHTC-enriched SICARBON™ material, produced by Airbus, was comprehensively evaluated and reported. Transition of the failure mode was obtained by tilting the specimens with horizontal build direction instead of lay-up configuration (vertical build direction). The tilted configuration allowed to get a valid flexural strength of 370 MPa even with small specimens of about 30 mm. To assess failure mode in different test configurations, virtual microstructure was generated on the base of cumulative distribution functions of observed microstructural features. Tsai-Wu failure criterion was extended in order to evaluate direction dependent failure indices for different lay-up configurations

Potentiometric Estimation of Potassium Octacyanomolybdate(IV)

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Private Incremental Regression

Data is continuously generated by modern data sources, and a recent challenge in machine learning has been to develop techniques that perform well in an incremental (streaming) setting. In this paper, we investigate the problem of private machine learning, where as common in practice, the data is not given at once, but rather arrives incrementally over time. We introduce the problems of private incremental ERM and private incremental regression where the general goal is to always maintain a good empirical risk minimizer for the history observed under differential privacy. Our first contribution is a generic transformation of private batch ERM mechanisms into private incremental ERM mechanisms, based on a simple idea of invoking the private batch ERM procedure at some regular time intervals. We take this construction as a baseline for comparison. We then provide two mechanisms for the private incremental regression problem. Our first mechanism is based on privately constructing a noisy incremental gradient function, which is then used in a modified projected gradient procedure at every timestep. This mechanism has an excess empirical risk of $\approx\sqrt{d}$, where $d$ is the dimensionality of the data. While from the results of [Bassily et al. 2014] this bound is tight in the worst-case, we show that certain geometric properties of the input and constraint set can be used to derive significantly better results for certain interesting regression problems.Comment: To appear in PODS 201