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Estimation of midpoint dose for cervical cancer patients using EPID

Balan G., Chandrasekaran A. R., Velayudham R., Annamalai G., Ramachandran M.

Polish Journal of Medical Physics and Engineering

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2018

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Vol. 24, Iss. 3

103--108

EN

Purpose: To estimate the midpoint dose delivered to cervical cancer patients treated by conventional technique using Electronic Portal Imaging Device (EPID). Materials and Methods: Clinac 2100 equipped with aS500 EPID was used in this study. A methodology was developed to generate a Gy/Calibration Unit (CU) look up table for the determination of midpoint dose of patients. 25 patients of cervical cancer were included in this study and the delivered dose to the midpoint of the patients was estimated using EPID. The deviation between the prescribed and the measured dose was calculated and analysed. Results: EPID showed a linear response with increase in Monitor unit and the Gy/CU look up table was validated for different field sizes and depth. 250 fields were measured for 25 patients, 10 measurements per patient, weekly once and for 5 weeks. The results show that out of 250 measurements, 98% of the measurements are within ±5% and 83.2% are within ±3% for with a standard deviation of 1.66%. Conclusion: The outcome of this study proves the efficacy of this methodology for the estimation of midpoint dose using EPID with minimal effort, time and without any inconvenience to the patients unlike other in-vivo dosimeters.

2

Optimization of turning process parameters by Taguchi-based Six Sigma

Das P. P., Gupta P., Ghadai R. K., Ramachandran M., Kalita K.

Mechanics and Mechanical Engineering

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2017

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Vol. 21, nr 3

649--656

EN

In this paper, Six Sigma approach is used for improving the quality process outputs in turning of Galvanized Iron. The objective is to optimize the turning parameters and maximize the MRR (Material Removal Rate). A L16 orthogonal array based on Taguchi experiments consisting of three controlling factors viz. spindle speed, feed rate, and depth of cut, each with four levels as required in traditional DOE setting is used here. Taguchi’s parameter design offers an approach in Design of Experiments (DOE) with control parameters optimization to attain best outcome. An orthogonal array offers a set of balanced least experiments which help in data analysis and prediction of optimum results. For each experiment, the Material Removal Rate (MRR) is calculated. The Taguchi method results in reducing the quality characteristic variation due to uncontrollable parameter through the study of response variation using the Signal to Noise (S/N) ratio by the use of Minitab 16 software. Moreover, statistical investigation shows that standard deviation and mean value of confirmation run data are reduced when compare with before Taguchi design run data was performed.

3

On intuitionistic fuzzy ideals in Γ - rings

Palaniappan N., Veerappan P. S., Ramachandran M.

Journal of Mathematics and Applications

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2010

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Vol. 33

91-101

EN

In this paper, we study some properties of intuitionistic fuzzy ideals of a Γ - ring and prove some results on these.

4

Fabrication and characterization of 1-D alumina (Al2O3) nanofibers in an electric field

Azad A.-M., Noibi M., Ramachandran M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2007

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Vol. 55, nr 2

195-201

EN

The technique of electrospinning was employed to fabricate uniform one-dimensional inorganic-organic composite nanofibers at room temperature from a solution containing equal volumes of aluminum 2, 4-pentanedionate in acetone and polyvinylpyrrolidone in ethanol. Upon firing and sintering under carefully preselected time-temperature profiles (heating rate, temperature and soak time), high-purity and crystalline alumina nanofibers retaining the original morphological features present in the as-spun composite (cermer) fibers were obtained. Tools such as laser Raman spectroscopy, scanning and transmission electron microscopy together with energy dispersive spectroscopy and selected area electron diffraction were employed to follow the systematic evolution of the ceramic phase and its morphological features in the as-spun and the fired fibers. X-ray diffraction was used to identify the crystalline fate of the final product.