NQS

About: NQS is a research topic. Over the lifetime, 337 publications have been published within this topic receiving 4226 citations.

Spectrophotometric Determination of Etravirine in Bulk and Pharmaceutical Formulations

Abstract: Two simple, rapid, sensitive, accurate, precise and economical Visible Spectrophotometric methods have been developed for the determination of Etravirine in pure and pharmaceutical formulations. These methods (A and B) were based on nucleophilic substitution and oxidative coupling reactions of Etravirine by 1,2-naphtha quinone-4-sulphonate (NQS) in alkaline medium and 3-methyl-2-benzothiazolinone hydrazone (MBTH) in acidic medium with the maximum absorbance at 414 nm and 635 nm respectively. Linearity was obtained in the concentration range of 5 -30 μg/ml and 2 -10 μg/ml which was corroborated by the correlation coefficient (r) values of 0.9995 and 0.9996 respectively. The methods developed were validated with respect to linearity, accuracy (recovery), precision, Sandell’s sensitivity, molar extinction coefficient and specificity. The proposed methods are successfully applied for the determination of Etravirine in bulk and pharmaceutical formulations and results were validated statistically by recovery studies.

Spectrophotometric determination of Diclofenac Sodium in pure form and in the pharmaceutical preparations

Abstract: A rapid, simple and sensitive method for the determination of Diclofenac sodium using sodium 1,2-naphthoquine- 4-sulfonate (NQS) as reagent in an alkaline medium (pH 11.9) to form an orange-colored product that was a maximum absorbance at 456 nm. Beer’s law is obeyed in the range (8-44 µg/mL), with molar absorptivity (6.965A—10 3 L/mol.cm), correlation coefficient 0.9996, and the limit of detection (0.185 µg/mL). The method has been successfully applied to the determination of Diclofenac sodium in pharmaceutical preparations

Non-Quasi-Static Modeling of Silicon Nanowire Metal–Oxide–Semiconductor Field-Effect Transistor and Its Model Verification up to 1 THz

Abstract: In this work, the radio-frequency (RF) performances of a silicon nanowire (SNW) metal–oxide–semiconductor field-effect transistor (MOSFET) were modeled by being grafted into the non-quasi-static (NQS) small-signal equivalent circuit for the first time. The parameters were analytically extracted from three-dimensional (3D) device simulations. The cutoff frequencies of an SNW MOSFET with a 30 nm channel length and a 5 nm radius were 504 and 545 GHz in the linear and saturation regions, respectively. The reliability of modeling results was verified by the simulations including realistic models. It was confirmed that the SNW MOSFET would be the promising candidate as a core component for RF systems aiming 1 THz operation.

Modeling of the Lateral Emitter-Current Crowding Effect in SiGe HBTs

Abstract: Two-section models for capturing the lateral ac emitter-current crowding effect, which is also known as the lateral nonquasi-static (NQS) effect, are presented following a consistent approach based on a model formulation for ac operating condition. Following the theoretical results, model formulations suitable for implementation in the large-signal domain are developed. The proposed two-section model performs better than the state-of-the-art model in both the large-signal and small-signal domains and appears to be suitable for accurately capturing the lateral NQS effect.

When do we need non-quasistatic CMOS RF-models?

Abstract: This paper presents criteria for the onset of NQS effects derived from time transient device simulations and S-parameter measurements. For the first time it has been proved that e.g, a 10 /spl mu/m NMOS transistor can be described up to 27 MHz and a 0.2 /spl mu/m device up to 46 GHz by the quasistatic approach while the accuracy of the description of the inversion layer charge is still 99%.