Single Analysis Procedure Research Articles

A column screening study: Validation of a RP-LC method for determination of teriflunomide with pentafluorophenyl stationary phase

The research focuses on column screening in order to develop a novel validation method to separate Teriflunomide significantly using comparative and equivalent column selection studies. This gives stationary phase efficiency relative to height equivalent to a theoretical plate (HETP) (>16000) and symmetry factor (<2.0%). After extensive column chemistry and technique development, the advanced Pentafluorophenyl (PFP) column separates halogenated drugs better. Teriflunomide is fluorinated drug, hence PFP is optimal for analysis. For statistical data comparison, the same chromatographic method was developed and transferred to another YMC Pack Pro C18 column that gives almost the same results as PFP column in terms of carbon load, pore size, and surface area. The refined and validated method yielded equivalent results with two stationary phases using a single analysis procedure. Column screening, technique creation, transfer, and validation with comparison studies with correlation coefficients over 0.999 are unique. The statistical data from both columns meets ICH requirements. The sensitive, reliable, robust, and reproducible approach is easy to apply in regular laboratory analysis. Data analysis showed that the validation study with PFP is better (LoD - 0.0015 ppm) for column ageing due to smaller injection volume and amount loaded in the column, shorter run time, and cheaper analysis cost. This research helps with column selection and method transfer with diverse column specifications. With less than 2.0% of RSD, the column screening analytical method validation is linear, precise, accurate, rugged, and efficient.

Finite element analysis of a thin piezoelectric bimorph with a metal shim using solid direct-piezoelectric and shell inverse-piezoelectric coupling with pseudo direct-piezoelectric evaluation

A thin triple-layer piezoelectric bender, also known as a piezoelectric bimorph with a metal shim, consists of an elastic layer (metal shim) sandwiched between two piezoelectric layers. It is one of the most commonly used piezoelectric composite structures in both sensing and actuation applications. Therefore, this study deals with the coupled piezoelectric-structure interaction analysis of a thin piezoelectric bimorph with a metal shim. In this work, the best features of the solid and shell elements were combined to analyze the piezoelectric and structural fields, respectively, in a thin piezoelectric bimorph with a metal shim. This approach addresses the shortcomings of using a single finite element mesh for both the piezoelectric and structural fields. A transformation method using the block Gauss-Seidel algorithm is employed to exchange the variables between solid direct-piezoelectric and shell inverse-piezoelectric analyses. The metal layer can be analyzed as an elastic body with electrical boundary conditions. A pseudo direct-piezoelectric evaluation method for the metal shim in the piezoelectric analysis is proposed. This method allows us to reuse the existing piezoelectric analysis program, where the metal shim is analyzed as the pseudo direct-piezoelectric material in a single analysis procedure. The homogenization method for the evaluation of bending rigidity and mass is used for modeling the single shell structure in the inverse-piezoelectric analysis of a thin piezoelectric bimorph with a metal layer. Numerical results are given for various electrical configurations of actuators and sensors to validate the present method. Comparison with an exact solution illustrates the accuracy, efficiency, and capability of the developed solid direct and shell inverse-piezoelectric analysis coupled with a pseudo direct-piezoelectric evaluation method to capture the sensor and actuator response of a thin piezoelectric bimorph with a metal shim.

Detection sensitivity for special nuclear materials with an advanced high-pressure xenon detector and robust fitting analysis

The sensitivity for detection of two special nuclear materials, /sup 235/U and /sup 239/Pu, using an advanced high-pressure xenon detector (HPXe) and robust fitting analysis (RFA) with RobWin is experimentally determined for a set of collections with varying attenuation thicknesses of lead. These measurements provide essential information that enables comparisons with other detector systems for nuclear portal monitoring applications. Advantages of the combined use of HPXe and RFA for nuclear portal monitors are discussed, and recent progress with them is described briefly. An experiment designed to provide data from which models for nuclear portal monitor design can be grounded is described. Spectra were collected at CEA/Saclay with an HPXe unit from MEPhI for both /sup 235/U and /sup 239/Pu With attenuating thicknesses of lead ranging from zero to four millimeters. A single analysis procedure that yielded consistent results for all spectra was developed to simulate the automated application of analysis without user intervention and without advance knowledge of shielding thickness. These two spectrum series were then analyzed with RFA methodology for detection sensitivity and is reported in a form that can be used for comparison with other detector systems and for optimization of design parameters for HPXe/RFA portal monitor systems.